Publications by Year: 1992

Forty‐three patients received etoposide, cyclophosphamide, and fractionated total body irradiation before allogeneic marrow transplantation. Fifteen patients had chronic myelogenous leukemia in chronic phase or acute leukemia in first remission (standard risk) and twenty‐eight patients with more advanced disease (high risk). All patients received etoposide 1,500 mg/m2 intravenously on day –8, cyclophosphamide 60 mg/kg/day intravenously on days –7 and –6, and total body irradiation at 170 cGy twice a day on days –3, –2, and –1. During the first 100 days 12 high risk patients (43%) died from causes unrelated to relapse while none of the standard risk patients died. Renal and hepatic dysfunction were also significantly increased during the first 14 days in the high risk group. The addition of 1,500 mg/m2 of etoposide to the cyclophosphamide and total body irradiation was well tolerated for patients with standard risk. However, the regimen was poorly tolerated with high mortality in patients with more advanced disease. © 1992 Wiley‐Liss, Inc. Copyright © 1992 Wiley‐Liss, Inc., A Wiley Company

Two clones (p17 and p13), each containing the complete coding sequence for the bovine cardiac Na+/Ca2+ exchanger, were obtained from a lambda gt10 cDNA library by screening with cDNA probes from the canine exchanger. The coding sequence of clone p17 was 92 and 98% identical to the canine cDNA at the nucleotide and amino acid levels, respectively. Nine of the 21 amino acid differences between the two exchangers were found within the 32-amino acid signal sequence. The sequenced portions of the 3' untranslated regions of the cow and dog clones were 88% identical. Na+/Ca2+ exchange activity was expressed in Xenopus laevis oocytes injected with cRNA from clone p17, and in COS cells transfected with expression vectors containing p17. Immunoprecipitation of 35S-labeled proteins from transfected cells with an antibody against the N-terminal portion of the bovine exchanger showed the presence of a 120-kDa protein corresponding to the intact cardiac exchanger. The second bovine clone (p13) did not express exchange activity in either of the above expression systems, presumably because it contained a 300-bp insert with multiple stop codons which interrupted the coding sequence. Comparison of the 5' untranslated regions of p13 and p17 revealed a 156-bp segment in p17 that was apparently spliced out of p13. This segment contained a short open reading frame. A chimera encoding the 5' untranslated region of p13 and the coding sequence of p17 exhibited only a modest (74%) increase in expressed exchange activity in transfected cells compared to p17, suggesting that the presence of the upstream open reading frame in p17 did not greatly reduce translation efficiency. The results suggest that alternate splicing mechanisms may be involved in processing mRNA for the bovine cardiac exchanger

The complexation of six tricyclic antidepressant drugs {[}amitriptylin (AMN), nortriptylin (NRN), imipramin (IMN), doxepin (DXN), protriptylin (PTN), and maprotilin (MPN)] with alpha-and-beta-cyclodextrins (CDs) using ion-selective electrodes (ISEs) as drug ion sensors is described. Binding parameters were calculated by nonlinear fitting of the model described by the Scatchard equation, to the experimental data of a titration of a CD solution with the ion of interest. One binding site (the CD cavity) was found in all cases with both CDs. The calculated association constants at 25-degrees-C using CD concentrations in the range of 0.0100-0.0010 M, varied from 4.81 x 10(3) M-1 (MPN) to 23.9 x 10(3) M-1 (AMN) in the case of beta-CD and from 50 M-1 (DXN) to 123 M-1 (MPN) in the case of alpha-CD. The precision for the estimation of the binding parameters was 0.1-5.0% (within-run RSD%) and 8-10% (between-run RSD%; n = 3). The complexation of the drugs with beta-CD was also examined as a function of temperature in the range of 5-37-degrees-C; it was found to decrease by increasing temperature. Van't Hoff analysis gave good correlations (r greater-than-or-equal-to 0.989) for all drug ions studied. The estimates of the thermodynamic parameters indicate that the formation of inclusion complexes is enthalpy driven. A compensation plot based on the thermodynamic parameters DELTA-H and DELTA-S resulted in a linear relationship, which is indicative of a common type of force involved in the complexation of drugs to beta-CD.

Compton scattering of low-frequency photons in a converging flow of cold plasma is studied. The equation of radiative transfer in the case of spherical near-critical steady state accretion onto a neutron star is solved analytically. The inner boundary condition is that the neutron star surface is completely reflective, or that there is a magnetopause with an empty cavity inside it. The photons escape diffusively and electron scattering is the dominant source of opacity. The energy gain of the photon comes entirely from the bulk motion of the converging flow of the accreting gas. The spectrum observed at infinity is a power law at high frequencies with photon number spectral index essentially -1. This spectrum is significantly flatter than that found for accretion into black holes.

In several studies in humans and animals it has been suggested that high osmolality and ionicity of contrast media are responsible for higher nephrotoxicity. To examine this suggestion, we evaluated the renal effects of three different contrast media-an ionic high osmolar, an ionic low osmolar, and a nonionic-following intravenous and renal arterial administration, in a population of 84 unselected, nondiabetic patients with adequate renal function. The results showed that the nephrotoxicity is minimal and equal for all three contrast media and for both routes of their administration, and it is concluded that in this category of patients the far higher cost of the newer low osmolar ionics and nonionics should be considered seriously in regard to nephrotoxicity. © 1992 Informa UK Ltd All rights reserved: reproduction in whole or part not permitted.

Purpose: The effects of involved-field radiotherapy were assessed in patients with a solitary plasmacytoma of bone (SBP). Patients and Methods: Forty-five consecutive patients with an SBP received megavoltage irradiation of at least 3,000 cGy. The median age was 53 years, 67% of patients showed a myeloma protein, and uninvolved immunoglobulins (Igs) were preserved in 93% of patients. Results: Permanent control of presenting disease was achieved in all but two patients, but 46% of patients developed multiple myeloma. When it occurred, progression of myeloma occurred within 3 years in two thirds of the patients, suggesting that the extent of disease was understaged at diagnosis. Myeloma protein disappeared in nine patients (30%) whose disease has not yet recurred. The median survival for all patients was 13 years and the myeloma- specific survival fraction at 10 years was 53%. Conclusion: In patients with an SBP, the disappearance of myeloma protein with involved-field radiotherapy predicted long-term disease-free survival and possible cure. Nonsecretory disease and persistent myeloma protein after treatment were adverse prognostic factors for which adjuvant therapy with interferon alfa should be considered.

The appropriate Scatchard equation was developed for a system involving the formation of 1:1 and 1:2 substrate:cyclodextrin complexes. Simulation of this system was performed under the most common experimental conditions encountered in this type of study. The use of the equation allows for nonlinear least-squares estimation of the association constants. The interaction of the model compounds 1-anilino-8-naphthalenesulfonate (1,8-ANS) and 2(p-toluidinyl)-6-naphthalenesulfonate (2,6-TNS) with beta-cyclodextrin (beta-CD) was used to evaluate the theoretical model. Binding experiments were performed using either potentiometric titration or fluorimetric detection. The experimental data for 1,8-ANS/beta-CD fit well to the 1:1 binding model, with an association constant of 87 +/- 1 M-1. The association constants of the 1:1 and 1:2 2,6-TNS/beta-CD complexes utilizing direct potentiometry were 3737 +/- 6 and 149 +/- 2 M-1. It is shown that fluorimetry can give biased estimates for the association constants of the complexation 2,6-TNS/beta-CD, since the assumption of an equivalent quantum yield of bound species is not valid.

Objective: To study and compare the secretion of pregnancy specific β1- glycoprotein (SP1) and human chorionic gonadotropin (hCG) by human pre- embryos, cultured in vitro, with their respective morphological development. Design: Spare human pre-embryos from randomly selected women participating in a program of in vitro fertilization (IVF) were studied prospectively. Setting: Pre-embryos were cultured, and hormone release was determined in academic research laboratories. Patients, Participants: Pre-embryos (n = 108) cultured for 14 days after fertilization in Ham's F-10 medium (GIBCO Ltd., Paisley, Scotland) were observed, and hCG and SP1 were measured in the culture media at regular intervals. Main Outcome Measures: Discordant secretion of SP1 and hCG. Results: Of the 98 bipronucleate pre-embryos, 53.6% formed blastocysts, 17.3% of which hatched. Human chorionic gonadotropin was detected from day 7 after fertilization concomitantly with blastocyst formation, thereafter showing a logarithmic increase (maximum 10,650 mIU) until the first signs of embryonic disintegration. Pregnancy- specific β1-glycoprotein release started 3 to 4 days after fertilization independently of the morphological development and the future production of hCG, thereafter displaying a nonlogarithmic increase (maximum 41 ng). Conclusions: Hormone secretion and morphological development are unique for each pre-embryo. Human chorionic gonadotropin and SP1 seem to have different biochemical and physiological regulation.

In this study we measured eight different tumor markers (PSA, PAP, TPA, CEA, Ca 50, Ca 19-9, Ca 125 and Ca 15-3) in 39 patients with prostatic adenocarcinoma and in 90 patients with benign prostatic hyperplasia. We then calculated the sensitivity and specificity for each tumor marker separately and found that only PSA, when we consider as normal value 10 ng/ml, has a sufficiently high sensitivity and specificity. Our conclusion is that only PSA can be used for diagnostic purposes in conjunction with other diagnostic modalities.

The EPR spectra of polycrystalline oxygenated and non-oxygenated (large oxygen deficiency) LaBa2Cu3O7- delta compounds, obtained at various temperatures, were studied and analysed. The oxygenated samples showed a transition temperature Tc at about 50 K. The EPR spectrum of the Cu2+ ions in the orthorhombic local symmetry was observed. It was found that these spectra are essentially influenced by an oxygen deficiency and thermal treatment. In the non-oxygenated samples, at a certain stage of the annealing process an EPR spectrum was detected at low temperatures. After the final anneal, this EPR spectrum showed significant changes. Changes were also observed in the corresponding XRD spectra indicating reductions in the concentrations of the CuO and BaCuO2 impurity phases. Additionally, the EPR spectrum of divalent copper ions in the axial local symmetry in the dx2-y2 ground state was observed.

EPR measurements at room temperature (RT) on the oxygen deficient (La, Tm)-Ba-Cu-O compound (tetragonal phase) revealed a line centered at g=2.895(5) with linewidth ΔH=0.015(1)T. The line is ascribed to Tm2+ ions (4f13, 2F7/2) assuming that the Γ(7) doublet is the ground state. A characteristic EPR spectrum of divalent copper ions was also observed. © 1992.

Carcinoembryonic antigen (CEA), cancer antigen 125 (CA-125) and squamous cell carcinoma (SCC) antigen were measured in 56 full-termed pregnancies by enzyme-immunoassays (EIA-MEIA). The measurements were done in maternal serum (MS), umbilical cord blood (UCB) and amniotic fluid (AF) samples, during delivery. Very high antigen levels were found in AF samples (median: CEA = 124 ng/ml; CA-125 = 710 U/ml; SCC = 710 ng/ml) compared to UCB and MS. CEA and SCC showed significantly lower value's in MS (0.6 and 1.7 ng/ml, respectively) than in UCB (1.6 ng/ml, P = 7.7 × 10-9; 3.55 ng/ml, P = 6.5 × 10-6, respectively), while CA-125 had significantly higher values in MS (6 U/ml) than in UCB (0.0 U/ml, P = 17 × 10-6; Wilcoxon paired test). All CEA values in MS were below cut-off (≤ 5 ng/ml), while 10% of CA-125 and 30% of SCC values were above cut-off (≤ 35 U /ml and ≤ 2.5 ng/ml, respectively). Amniotic fluid CEA with meconium had higher values (P = 0.0002), while the highest CA-125 values in AF samples were found in primiparae (P = 0.02). Moreover SCC in AF samples from vaginal delivered pregnancies showed significantly higher values, compared to those from cesarean section (P = 4.2 × 10-7; Mann-Whitney U-test). Thus, our findings suggest that pregnancy has an influence on maternal serum SCC and CA-125 values, while CEA is independent of gestation and seems to conserve its diagnostic value during pregnancy as well. © 1992.

Basic characteristics of on-line extractive fermentation of organic acids were examined using a general model for the integrated process in order to illustrate the effects of various process parameters and operational modes on system performance. The strong pH dependence of both the fermentation kinetics and the extraction efficiency has been outlined and taken into account by inclusion of a model equation which predicts the pH profile. Simulation results using data from butyric acid fermentations show that our complete model system is adequate to evaluate different operational modes of the process, including simple batch fermentation, batch or fed-batch fermentation with extractive recycle, and continuous fermentation with extractive recycle. In the case where a second undesired acidic byproduct is also produced, our model predictions suggest that on-line extractive fermentation using a suitable solvent results in an effective gross separation of the two acids.

The spin-orbit scattering of 4sp and 5sp impurities in a Mg host is investigated theoretically by self-consistent local-density-functional theory. The calculated spin-orbit scattering cross sections sigmaSO agree with the available experimental results for low valent impurities. For higher valent impurities we predict a p resonance behavior. For Cu and Ag impurities our results point to errors of density-functional theory in estimating the d contribution to sigmaSO. In total a consistent interpretation of the trends is given.

We propose that the important relationship between 3C 273 and 3C 279, the first two extragalactic sources detected at > 100 MeV energies, is their superluminal nature. In support of this conjecture, we propose a kinematic focusing mechanism, based on Compton scattering of accretion-disk photons by relativistic nonthermal electrons in the jet, that preferentially emits gamma rays in the superluminal direction.

An expanded polytetrafluoroethylene (PTFE) prosthesis used to reconstruct the posterior cruciate ligament in a 37-year-old Caucasian male was retrieved and histologically examined in this study. Backscattered electron (BSE) microscopy, utilized to observe the mineralized tissue ingrowth into the retrieved specimen, revealed an absence of bony ingrowth within the graft. Light microscopy demonstrated an exuberant foreign body giant cell response surrounding and invading the substance of the graft, and also revealed evidence of graft degradation. These observations indicate that PTFE may not be as favorable a material for reconstruction of ligamentous tissues as previously reported.

The cycles of 11 renal transplant recipients (RTR), at least 24 months after stabilization of graft function and four hemodialyzed (HD) patients, menstruating regularly, were evaluated by concurrent and systematic determinations throughout the cycle of LH, FSH, estradiol, progesterone, testosterone, prolactin and SHBG and in the case of RTR also by ultrasound follow-up. Biphasic estradiol secretion, midcycle LH and FSH surge, duration of luteal phase, midluteal progesterone values and in the case of RTR, ultrasonic parameters were consistent with: (1) normal ovulatory cycles in five RTR; (2) ovulatory cycles with luteal phase deficiency in five RTR and two HD patients; (3) anovulatory cycles in one RTR and two HD patients. Thus, in HD patients only abnormal cycles of central etiology were found, while in RTR, luteal phase deficiency was a very common syndrome, in equal percentage with normal ovulatory cycles. © 1992.

Are follicles where no oocytes are retrieved "empty follicles"? © 1992 Plenum Publishing Corporation.

A careful review of the literature revealed that no data had been reported on the angular difference or similarity between the posterior condylar axis used by many surgeons for primary total knee arthroplasty and the transepicondylar axis, which has been considered a useful anatomical landmark for femoral component placement in revision total knee arthroplasty. The purpose of this study was to determine whether measurable differences exist between the posterior condylar axis and the transepicondylar axis of the human femur. Nineteen pairs of human donor femora were measured. This study demonstrated that when the posterior condylar axis was taken as 0 degrees of rotation, the transepicondylar axis was found to be approximately 5 degrees externally rotated for both right and left femora, a significant difference (P < .05). However, there was no statistically significant difference in the angle measured between the posterior condylar axis and the transepicondylar axis when comparisons were made between matched right and left femora (P > .05). It is suggested that this information can be applied to improving the techniques currently used in the placement of both primary and revision femoral knee components.

A point matching method is applied to the problem of light scattering by non-spherical bodies. The electromagnetic field is expanded into a series of spherical waves which include all multipole terms which contribute significantly to the wavefield. We examine, in particular, the absorbance of light by a plasma particle and demonstrate the existence of various peaks associated with dipole and quadrupole resonances of the induced charge distribution.

The local magnetic properties of 3d and 4d substitutional impurities in noble and alkali-metal hosts are investigated by means of self-consistent local-spin-density-functional calculations using the jellium model as well as the first-principles Korringa-Kohn-Rostoker–Green’s-function method. The results for the impurity moment from both calculations are in good agreement and compare well with the available experimental data. Our calculations give a consistent picture for the formation of local impurity spin moments in free-electron-like hosts.

The EPR spectra of perovskite ceramics of Gd0.5RE0.5Ba2Cu3O7−δ type (RE  La, Pr, Nd, Sm, Eu, Dy, Ho, Y, Er, Tm, Yb, and Lu) in tetragonal (non‐HTC) phase are investigated as a function of temperature in the range 40 to 3 K. A signal arising from the isotropic exchange interaction of coupled pairs of Cu2+ ions is detected. The intensity of this signal is strongly dependent on the RE ions and its g‐factor varies with temperature. Magnetic measurements show the existence of ferromagnetic anomalies at these low temperature. In the orthorhombic phase, these materials exhibit a superconducting phase transition in the range of 85 to 95 K, apart from the samples with La ions where a TC ≈ 69 K is found and the samples with Prions where a superconducting state can not be observed. Copyright © 1992 WILEY‐VCH Verlag GmbH & Co. KGaA

Spinal magnetic resonance (MR) imaging was performed in 29 patients with newly diagnosed, untreated multiple myeloma. Nineteen (66%) patients were asymptomatic. Sagittal pre- and postcontrast T1-weighted spin-echo images and gradient-recalled-echo images of the thoracic and lumbosacral spine were obtained. Marrow involvement was identified in 20 (69%) patients. There were three MR patterns: focal lesions in nine patients (31%), diffuse involvement in seven (24%), and an inhomogeneous pattern of tiny lesions on a background of normal marrow in four (14%). A statistically significant correlation between MR imaging patterns of marrow involvement and serum hemoglobin values (one-way, P = .0899; Kruskal-Wallis, P = .0620) and between MR imaging patterns and percentage of marrow plasmacytosis (Kruskal-Wallis, P = .0314) was noted, with patterns of diffuse and focal marrow involvement associated with more abnormal values. Spinal MR imaging in patients with early myeloma may reveal marrow involvement in both symptomatic and asymptomatic patients. Some correlation was found between MR imaging patterns and laboratory indexes of disease.

We describe a method for the calculation of the optical properties of a two-dimensional array of non-overlapping metallic particles (approximated by spheres) adsorbed on a dielectric slab. The interest in such systems arises to a large degree from their possible use as coatings, e.g. for solar energy absorbers and similar technological purposes. The formalism is an extension of the methods which have been developed in relation to electron scattering by two-dimensional atomic layers and takes fully into account multiple scattering of light between the particles of the overlayer and between the overlayer and the substrate. Scattering of light by multilayers or by an infinite crystal of non-overlapping spheres can be dealt with by a straightforward extension of the theory as in the theory of low-energy electron diffraction. Our calculations show that the usual approximation of replacement of the metallic particles by effective dipoles fails when the size of the particles or the concentration of particles increases beyond a limit and that l-pole contribution in interparticle scattering beyond the dipolar (l=1) one introduces new structure in the absorbance versus frequency curve. The reflection and absorption of light as a function of frequency is obtained numerically for selected examples. We consider in particular the variation of these quantities with concentration coverage. We examine also the effect of disorder.

When energetic electrons Compton scatter soft photons in the Klein-Nishina regime, the produced gamma rays are subject to photon-photon pair attenuation, and a pair-Compton cascade results. We examine the formation of such cascades in the spatially varying photon fields encountered by high-energy electrons and photons emitted from luminous compact objects. Constraints on the geometry of the soft photon source and the location of the gamma-ray production site are deduced from observations of 100 MeV and TeV gamma rays emitted by galactic compact objects and active galactic nuclei.

The potential role of paraneoplastic Cushing's syndrome (CS) was assessed on the clinical course of patients with small cell lung cancer. A retrospective comparison was done of complication and survival rates according to the presence or absence of CS in patients with small cell lung cancer who died within 90 days of initial administration of chemotherapy. The setting was a comprehensive cancer center. Eleven patients with clinical and/or biochemical features of CS were identified from among 90 patients who presented between 1979 and 1989 with previously untreated small cell lung cancer. The group with CS and the control patients were compared in terms of clinicopathologic prognostic factors, treatment, and outcome. Patients with CS were comparable to the control patients in all prognostic factors, including tumor stage and cancer treatment. Eight‐two percent of patients with CS (nine of 11) died within 14 days of initiation of chemotherapy compared with 25% of the control patients (19 of 77). The median survival from initiation of chemotherapy was 12 days for the 11 patients with CS and 27 days for the 77 control patients. In 45% of the patients with CS (five of 11), death was attributed to opportunistic fungal or protozoal infection compared with 8% of control patients (six of 77). paraneoplastic CS is a previously unrecognized adverse prognostic factor for patients with small cell lung cancer. Those with both small cell lung cancer and CS have severe opportunistic infections soon after the initiation of chemotherapy, leading to clinical deterioration and death before antineoplastic benefit from chemotherapy can be achieved. Biochemical control of CS for at least 1 to 2 weeks before initiation of chemotherapy may ameliorate the poor prognosis. Copyright © 1992 American Cancer Society

Electron paramagnetic resonance obtained from the tetragonal RBa2Cu3O6+x (R ≡ Nd, Sm, Tm) compounds exhibit a well defined line resulting from coupled divalent Cu ions. Below 20 K the g parameter of this signal is strongly temperature dependent. At about the same temperatures there is a ferromagnetic-like transition in the magnetic susceptibility. © 1992 Taylor & Francis Ltd.

Intermittent courses of dexamethasone (DEX) were administered to 112 consecutive, previously untreated patients with multiple myeloma (MM). Using criteria based on a 75% or greater reduction of calculated tumor mass, the overall response rate was 43%. Among comparable patients, response rates were approximately 15% less than those observed previously with vincristine-doxorubicin by continuous infusion with intermittent DEX (VAD) and similar to those with melphalan-prednisone. The projected survival times with VAD or DEX were similar. Results indicated that DEX accounted for most of the plasma cell reduction achieved with VAD. Serious complications occurred in 27% of patients treated with VAD, but in only 4% of those who received DEX. In view of the similar outcome with fewer serious complications, DEX provided a simple, effective, and safe primary treatment for a large fraction of patients with MM. Patients who appear most likely to benefit include those with hypercalcemia or pancytopenia, or who require simultaneous radiotherapy for a pathologic fracture. © 1992 by The American Society of Hematology.

The study determined intrinsic factors which contributed to the falls of adults hospitalized in a general hospital during 1987-88. Two hundred and fourteen patients were studied in two groups. Group A consisted of 108 patients who fell during their hospitalization and control Group B consisted of 106 patients with the same characteristics also hospitalized during the same period who did not fall. Of the 23 variables which have been analyzed by the multivariate logistic regression method, seven present statistically significant incidence and increased risk of patients' falls: (1) gender: the number of accidents occurring among male patients was higher than that among females (p = 0.0022); (2) age: the majority of accidents occurred in the 65 greater than or equal to years old age group (p = 0.00426); (3) general pathological conditions: mostly patients with cardiac problems (p = 0.0062); (4) neoplasms (p = 0.0334); (5) anaemias (p = 0.0128); (6) post-operative conditions (p = 0.0063); and the taking of hypnotic/tranquilizer drugs (p = 0.0486). Other significant findings were: the highest incidence of falls occurred during the first 4 days of the patients' admission to hospital and most during the early morning hours (5-6 am). Injuries incurred were bruises (32.4%), minor injuries (24%), major injuries (16.7%) and fractures (10.2%). The high correlation between patients' falls and (1) specific diseases, namely neoplasms, anaemias, cardiac and post-operative conditions and (2) the taking of hypnotic/tranquilizer drugs are risk factors in relation to patients' falls in general hospitals.

Existing models for X-ray emission from novae in outburst encounter several difficulties. The X-ray flux that may be expected to result from Compton degradation of gamma rays produced by radioactive decays is calculated. It is demonstrated that radioactive decays of Na-22 may play an interesting role in the production of hard X-rays, particularly in novae enriched in oxygen, neon, and magnesium.

Kamberidou, Irene. (1992). “The role of Women in Building a Europe without Frontiers”, Greek Economy, International Magazine for Trade and Investment, Ekdotiki Economiki, Athens, issue 6: 72-74. --Began contributing in 1990 as a journalist, responsible for EEC Affairs (1990- 1991), progressively becoming Editor in Chief (1991-1992). [Ξεκίνησα τη συνεργασία μου ως δημοσιογράφος το 1990 και υπεύθυνη του τομέα EEC Affairs και στην συνέχεια ως Αρχισυντάκτης (1991-1992).]

The authors consider periodic structures made of spheres embedded in a host material with a different dielectric function. They show how to calculate the reflection and transmission of electromagnetic waves by a slab of the material parallel to a given crystallographic plane. The method of calculation is based on a doubling-layer scheme which obtains the reflection and transmission matrix elements for the multilayer from those of a single layer. The reflection and transmission characteristics of the slab are related to the complex band structure of the photon field associated with the given crystallographic plane of the corresponding infinite crystal, which is introduced in the manner of the low-energy electron diffraction theory. They present numerical results which demonstrate the applicability of the method to real systems of current interest and point out some interesting physics which arose from their calculations. They show in particular that the nondegenerate bands of the photon field at the centre of the surface Brillouin zone do not couple to the incident radiation, leading to total reflection at normal incidence.

α-Immunoreactive inhibin was measured using an enzyme immunoassay kit in the culture medium (Ham's F-10 medium supplemented with 14% heat-inactivated human serum) from day 3 or 4 to day 14 post-fertilization of 31 surplus pre-embryos from eight women participating in an in-vitro fertilization programme. Inhibin secretion was demonstrated in all of them from the fourth day after fertilization (mean ± SEM: 3.0 ± 0.7U) and was independent of the morphological development of pre-embryos (2-4 cells, n = 4; 6-8 cells, n = 4; 8-10 cells, n = 9; 10-12 cells, n = 4; morulae, n = 5 and blastocysts, n = 4). On days 7,10,13 and 14 post-fertilization, mean inhibin values ± SEM for non-disintegrated pre-embryos were respectively: 6.5 ± 0.9U, 12.3 ± 2.0U, 16.8 ± 3.2U and 20.2 ± 3.7U; however, when disintegration was noted on days 10 and 13 after fertilization, inhibin mean values were 9.0 ± 1.4U and 8.4 ± 1.7U respectively. Inhibin levels were significantly correlated with human chorionic gonadotrophin levels in the same culture media only on day 13, while correlation with pregnancy specific β1-glycoprotein occurred on day 7 post-fertilization. In conclusion, early human pre-embryos secrete α-immunoreactive inhibin before the cytotrophoblast is formed. This secretion increases significantly with time when development is continued, while disintegration is followed by a net decline in the rate of inhibin release.

There is a wide spectrum of disease among patients with plasma cell myeloma. A small fraction have a localized plasmacytoma of bone that requires specialized techniques for accurate staging, followed by local radiotherapy that may be curative in some patients. Other patients with multiple myeloma may be free of symptoms and the disease is recognized by chance laboratory studies. Some have a prolonged, stable course with little change in disease for many months or years and resemble patients with MGUS. These patients have low serum myeloma protein and are free of focal bone lesions even on MR imaging. Complications are more imminent among other patients with higher levels of myeloma protein and/or bone lesions, who usually require treatment within 2 years after diagnosis. Still other patients with more advanced generalized disease (intermediate tumor mass) or with a pathologic fracture that may be relieved with local radiotherapy usually require even earlier chemotherapy to prevent or treat complications.

The fourth in a series of papers on the large-scale structure and stellar content of the Small Magellanic Cloud (SMC), based on photometric analysis of sets of blue and red UK Schmidt photographic plates, is presented here. The previous papers reviewed the data reduction procedures and presented results on the three-dimensional structure of a large sector of the outer regions of the SMC beyond 2^deg^ from the SMC centre. Here, we present a study of the age and spatial distribution of stellar populations in an area covering six UKST survey fields, i.e. virtually the entire outer area of the SMC. The existence of a very old stellar population of age 15-16 Gyr, comprising about 7 per cent of the stellar content of the outer regions by mass, is suggested by the observational results. However, the bulk of the stellar population in the outer regions of the SMC is found to be about 10 Gyr old. The distribution of stellar populations younger than about 2 Gyr is shown to be biased towards the eastern side of the SMC facing the LMC. The star formation history of the outer regions is discussed with particular reference to the role of interactions between the LMC-SMC-Galaxy system.

Four evergreen sclerophyllous species were investigated morphologically and anatomically. Buds, leaves and roots from Ceratonia siliqua, Olea europaea, Pistacia lentiscus and Quercus coccifera were studied and compared for structural diversity. Analysis of the anatomical data suggested diverging features. The ecological equivalence of these species cannot be attributed to their structure. © 1992.

EPR spectra between 9.7 K and room temperature (RT) were taken for EuBa2Cu3O7-δ in tetragonal and orthorhombic phases. Our results indicate significant differences between the EPR spectra of Cu2+ ions in the tetragonal and orthorhombic phase. It is concluded that in the tetragonal phase, the Cu2+ complex has axial symmetry. Furthermore, at low temperatures the observed EPR signal is associated with superexchange interaction between Eu2+ ions across oxygen bridges. © 1991.

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ACTIVE galactic nuclei (AGNs) exhibit high luminosity with rapid variability, especially in X-ray emission, for which the luminosity can be greater than that of a normal galaxy, and the variability timescale implies an emitting region in some cases smaller than one light hour1. The hard X-ray spectrum of AGNs is nonthermal, probably arising from an electron-positron pair cascade, with some emission reflected off relatively cold matter2,3. Energy can be pumped into a cascade by any process that produces relativistic pairs, but because electrons and positrons are hard to accelerate efficiently, there has been interest in models in which protons are accelerated4,5, and create relativistic electrons on interaction with a local radiation field6-8. Here we show that a sufficient column density of protons can lead to runaway pair production: photons generated by the relativistic pairs are the targets for the protons to produce more pairs. This process can produce X-ray flares with the observed characteristics, and our model predicts the maximum ratio of luminosity to source size ('compactness') as well as their spectrum in the early phases. The same mechanism may also be able to create the knots of synchrotron-radiating pair plasma seen in sources such as 3C273.

EPR, XRD, and magnetic studies are presented for Pr0.5Re0.5Ba2Cu3O7-δ compounds (Re= La, Nd, Sm, Eu, Gd, Dy, Ho, Y, Er, Tm, Yb, and Lu) in the orthorhombic and tetragonal (large oxygen deficiency) phase. For the samples with Re=Dy, Ho, Y, Er, Tm, Yb, and Lu in the orthorhombic phase, the transition to the superconducting state has been observed in the temperatures range Tc between 18 and 40 K. For the samples with Nd and Yb in the tetragonal phase, EPR spectra coming from trivalent rare earth ions have been recorded. In the nonoxygenated sample Pr0.5La0.5Ba2Cu3O7-δ the EPR spectrum arising from the non-Kramers trivalent praseodymium ion has been observed. A broad EPR line appearing in all our samples was attributed to superexchange interaction between copper ions over oxygen (O2-) bridges. Interestingly, for the Pr0.5Re0.5Ba0.5Cu3O7-δ (Re = Er and Lu) compounds in the tetragonal phase at liquid-nitrogen temperature, a nonresonant microwave absorption in low magnetic fields has been detected. © 1992 Plenum Publishing Corporation.

(1992). Γογγάκη Κωνσταντίνα. Δημήτρης Άνθης. Ο ζωγράφος-ποιητής. Πόρφυρας, 60:157-158.                   Ο ζωγράφος Δημήτρης Άνθης (1925-1991) υπήρξε μαθητής του Γάλλου ζωγράφου Tin Florias της σχολής της Μονμάρτης, και προσωπικός φίλος του τεχνοκρίτη, ιστορικού της τέχνης, Τζούλιο Καΐμη. Στην ζωγραφική του εξιδανί­κευσε τη μορφή της Γυναίκας και μορφοποίησε την Αγάπη. Στις "Παναγίες" του, που μαζί με τα τοπία και τις προσωπογραφίες του αποτελούν τα πλέον χαρακτηριστικά έργα του, συνυπάρχουν όλα τα θηλυκά σύμβολα, αλλά περισσότερο η Μάνα, ως σύμβολο του Πόνου και της Εγκαρτέρησης. Στην αγκαλιά της κρατάει τον Γιο της, τα χαρακτηριστικά του προσώπου του οποίου αντικαθιστά ένας σταυρός. Δεν μπορεί, ωστόσο, κανείς να δει το ένα σύμβολο χωρίς το άλλο: τη Μάνα δηλαδή χωρίς τον Γιο - Σταύρωση, ή τον Γιο χωρίς την θεϊκή προστασία της Μάνας, αλλά μόνο ως αδιάσπαστη ενότητα μπορεί να τα εκλάβει. Ο Άνθης δεν σταμάτησε ποτέ το οδοιπορικό του. Ο ίδιος άλλωστε ήταν ένας οδοιπόρος, στη ζωή και στην τέχνη, στη γνώση και στην αναζήτησή της. Αυτή η πορεία του στην ποιότητα εκφράζεται μέσα στο έργο του. Από τα σκοτεινά, ποιητικά και μυστικιστικά έργα του πρώτου καιρού, θα φτάσει στα αρμονικά, εξαϋλωμένα θαρρείς έργα. Τα έργα του Άνθη, κατά τον φιλόσοφο Καΐμη, δεί­χνουν μιαν αγάπη για την αλήθεια στη Τέχνη και μιαν απώτερη καλλιέργεια στη μελέτη του ατόμου και της φύσης, γι' αυτό και αποδίδουν μια πλούσια ποιότητα.  http://www.anthisdimitris.gr/index.php?option=com_content&view=article&id=196:goggaki-konstantina-gia-anthi&catid=41:news&Itemid=79      

(1992). Γογγάκη Κωνσταντίνα. Νέα μέτρα του Ισραήλ για περαιτέρω επιδείνωση της εκπαίδευσης στην Παλαιστίνη.Ο Ισραηλινός στρατός συνεχίζει την επίθεσή του εις βάρος του παλαιστινιακού λαού και ειδικότερα της εκπαίδευσης της Παλαιστίνης, χρησιμοποιώντας βία κατά των σχολείων και των μαθητών. Μερικά σχολεία υφίστανται επιθέσεις και εκτοξεύονται δακρυγό­να στις αυλές και στις τάξεις, ενώ άλλα κλείνουν για αόριστες χρονικές περιόδους με στρατιωτικές εντο­λές. Επίσης, η απαγόρευση της κυ­κλοφορίας σαν μέτρο συλλογικής τιμωρίας έχει χρη­σιμοποιηθεί ευρύτατα από τις στρατιωτικές αρχές στις κοινότητες της Δυτικής Όχθης και τη Γάζα, εμποδίζοντας χιλιάδες μαθητές και φοιτητές να παρακολουθήσουν τα μαθήματα και να συμπληρώσουν τις σπουδές τους. Υπάρχουν περιπτώσεις που οι φοιτητές αναγκάστηκαν να συνεχίσουν τις εξετάσεις μέσα σ' ένα κλίμα σύγχυσης, συ­χνών πυροβολισμών και στο θόρυβο των μεταφερόμε­νων μεγαφώνων. Ένα άλλο «νέο» μέτρο συλλογικής τιμωρίας, που χαρακτηρίζει τη στάση των Ισραηλινών αρχών απέναντι στην εκπαιδευτική κατάσταση στην Παλαιστίνη, είναι η απόφαση του ισ­ραηλινού υπουργείου Άμυνας για νέα παράταση του κλεισίματος του Πανεπιστημίου Birzeit - του δεύτερου μεγάλου Παν/μίου της Δυτ. Όχθης με­τά το Al-Najah - κατά στη Ramallah, υπονομεύοντας σημαντικά τις όποιες προσπάθειες για το χτίσιμο κάποιας εμπι­στοσύνης ανάμεσα στους Παλαιστίνιους και στους Ισραηλινούς. Οι φοιτητές του παρακολουθούν μαθήματα σε νοικιασμένα κτήρια, έξω από την πανεπιστημιούπολη της Ramallah, στερούμενοι όπως και οι καθηγητές, τα πνευματικά και κοινωνικά πλεονεκτήματα της εξαιρετικής παν/κής βιβλιοθήκης, των εργαστηρίων και άλλων διευκολύνσεων. Εκτός από τα παραπάνω, το Educational Network και άλλοι εκπαιδευτικοί ορ­γανισμοί κλήθηκαν στα στρατιωτικά αρχηγεία στην Δυτική Όχθη για απαγόρευση των συγκεντρώσεων των καθηγητών, των συνεδριάσεων, της λειτουργίας των εργαστηρίων χωρίς την άδεια της Ισραηλινής δημό­σιας διοίκησης. Γίνεται επομένως φανε­ρό ότι αυτό που επιδιώκουν οι Ισραηλινοί είναι να εντείνουν τον έλεγχό τους επάνω στα Παλαιστινιακά εκπαιδευτικά ιδρύματα και τις δραστηριότητες. Το συναίσθημα που επικρατεί στους Παλαιστίνιους, είναι ότι οι Ισραηλινοί έχουν αυξήσει τις πιέσεις ενα­ντίον τους και είναι εκτός ελέγχου, ενώ ο υπόλοιπος κόσμος τους έχει ξεχάσει.     *Σημείωση των «Αντιτετραδίων της Εκπαίδευσης»: Τα στατιστικά στοιχεία για τα Ιδιωτικά, Κυβερνητικά και UNRWA Σχολεία, Προπαρασκευαστικά, Στοιχειώδους Εκπαίδευσης και Γυμνάσια, που συγκέντρωσε η Κων/να Γογγάκη κατά το ταξίδι της στην Παλαιστίνη, προέρχονται από το EDUCATIONAL NETWORK, και βλέπουν το φως της δημοσιότητας για πρώτη φορά στην Ελλάδα. 

(1992). Γογγάκη Κωνσταντίνα. Το εκπαιδευτικό πρόβλημα στις κατεχόμενες περιοχές της Παλαιστίνης. Αντιτετράδια της Εκπαίδευσης, 17-18: 59-63. Στην εργασία διερευνώνται οι πολιτικές, κοινωνικές και εκπαιδευτικές συνθήκες μέσα στις οποίες γίνεται προσπάθεια για τη λειτουργία ενός, έστω, υποτυπώδους εκπαιδευτικού συστήματος, στη Δυτική Όχθη και τη Λωρίδα της Γάζας. Οι Ισραηλινές στρατιωτικές αρχές έχουν επιβάλλει μεγάλο αριθμό στρατιωτικών διαταγών, που εφαρμόζονται ακατάπαυστα, προκειμένου να ασκούν τον έλεγχο στην καθημερινή ζωή και την εκπαίδευση των «κατεχόμενων» Παλαιστινίων. Τα προβλήματα στις κατεχόμενες περιοχές της Παλαιστίνης είναι δριμύτατα, ενώ στην περιοχή της Λωρίδας της Γάζας είναι ακόμη εντονότερα, καθώς εκεί υπάρχει μεγάλος αριθμός προσφυγικών καταυλισμών. Οι συνθήκες επιβίωσης είναι δραματικές, ενώ η ανυπαρξία κρατικής δομής, οι καθημερινοί εποικισμοί σε περιοχές των Παλαιστινίων, η απαγόρευση κυκλοφορίας και οι επιθέσεις, καθιστούν τις συνθήκες ζωής εξαιρετικά επικίνδυνες και την ίδια την επιβίωσή τους. Είναι φυσικό, υπό της συνθήκες του ελέγχου αυτού και την οικονομική εξάρτηση της Παλαιστίνης από το κραταιό οικονομικά Ισραήλ, τα ζητήματα της εκπαίδευσης να υπονομεύονται, αφού η σύγχυση που δημιουργείται ως προς την άμεση χρησιμότητα της εκπαίδευσης καθιστά στη συνείδηση των κατοίκων την παιδεία ως όχι πολύ σπουδαίο προσόν. Η ανασφάλεια της ζωής, η ανυπαρξία υποδομών στους καταυλισμούς, ο ελάχιστος αριθμός ωρών κατά τις οποίες μπορούν να διατηρηθούν τα σχολεία ανοιχτά -λόγω της απαγόρευσης της κυκλοφορίας- και οι φυλακίσεις των μαρτύρων, αποτελούν εν τέλει, μία δραματική σύνθεση, η οποία αποδυναμώνει και περιθωριοποιεί το ανθρώπινο δυναμικό που ζει στις ταραγμένες αυτές περιοχές της μεσογείου. Παρά τα προβλήματα, ωστόσο, οι μικροί Παλαιστίνιοι μαθητές και οι μαθήτριες επιχειρούν να κατακτήσουν την γνώση που θα τους οδηγήσει προς το μέλλον. Στην εργασία παρέχονται στατιστικά στοιχεία για την προβληματική εκπαιδευτική κατάσταση τόσο για τις περιοχές της Δυτικής Όχθης, όσο και για τη Γάζα. Η εργασία αποτελεί καταγραφή της προσωπικής εμπειρίας της Κων/νας Γογγάκη από τις παραπάνω κατεχόμενες περιοχές της Παλαιστίνης κατά την επίσκεψή της εκεί το καλοκαίρι 1991 στη διάρκεια της Intifada (نتفاضة), και τα (απαγορευμένα έως τότε) στατιστικά στοιχεία δημοσιεύονται για πρώτη φορά στην Ελλάδα.