Self-diffusion of (31)Si and (71)Ge in relaxed Si(0.20)Ge(0.80) layers

Self-diffusion of implanted (31)Si and (71)Ge in relaxed Si(0.20)Ge(0.80) layers has been studied in the temperature range 730-950 degrees C by means of a modified radiotracer technique. The temperature dependences of the diffusion coefficients were found to be Arrhenius-type with activation enthalpies of 3.6 eV and 3.5 eV and preexponential factors of 7.5 x 10(-3) m(2) s(-1) and 8.1 x 10(-3) m(2) s(-1) for (31)Si and (71)Ge , respectively. These results suggest that, as in Ge, in Si(0.20)Ge(0.80) both (31)Si and (71)Ge diffuse via a vacancy mechanism. Since in Si(0.20)Ge(0.80) (71)Ge diffuses only slightly faster than (31)Si , in self-diffusion studies on Si-Ge (71)Ge radioisotopes may be used as substitutes for the "uncomfortably" short-lived (31)Si radiotracer atoms.

Reversible shape evolution of Ge islands on Si(001)

The evolution of strained Ge/Si(001) islands during exposure to a Si flux was investigated by scanning tunneling microscopy. Dome islands display appreciable shape changes at Si coverages as low as 0.5 monolayer. With increasing coverage, they transform into [105]-faceted pyramids, and eventually into stepped mounds with steps parallel to the <110> directions. These morphological changes are induced by alloying and represent a complete reversal of those previously observed during Ge island growth. The results are interpreted with a simple model in which the equilibrium shape of an island mainly depends on its volume and composition.

Studies on modified estrogens: towards the synthesis of novel 14,15-cyclopropa[a]estra-1,3,5(10),8-tetraenes

To improve the ratio of non-hormonal to hormonal activity, estrogens 3 and 4 were modified at various molecule positions. Isomerization of the 14 alpha,15 alpha-methylene bridge, controlled 3-methoxy group cleavage with respect to the 14 alpha,15 alpha-methylene bridge stereochemistry, reduction of the 8-double bond, and substitution of the oxyfunctionality at C-17 by a methylene and a difluoromethylene moiety were in the focus. As a result of in vivo and in vitro tests, compounds 27 and 29 were selected as potential follow-up candidates of lead 3.

Prepro-orexin and orexin receptor mRNAs are differentially expressed in peripheral tissues of male and female rats

Orexins are produced specifically by neurons located in the lateral hypothalamus. Recent results suggested peripheral actions of orexins. Therefore, we analyzed the mRNA expression of prepro-orexin and the orexin receptor subtypes OX(1) and OX(2) in peripheral rat tissues. Using real-time quantitative RT-PCR we detected significant amounts of prepro-orexin mRNA in testis, but not in ovaries. OX(1) receptor mRNA was highly expressed in the brain and at lower levels in the pituitary gland. Only small amounts of OX(1) receptor mRNA were found in other tissues such as kidney, adrenal, thyroid, testis, ovaries, and jejunum. Very high levels of OX(2) receptor mRNA, 4-fold higher than in brain, were found in adrenal glands of male rats. Low amounts of OX(2) receptor mRNA were present in lung and pituitary. In adrenal glands, OX(2) receptor mRNA was localized in the zona glomerulosa and reticularis by in situ hybridization, indicating a role in adrenal steroid synthesis and/or release. OX(1) receptor mRNA in the pituitary and OX(2) receptor mRNA in the adrenal gland were much higher in male than in female rats. In the hypothalamus, OX(1) receptor mRNA was slightly elevated in female rats. The differential mRNA expression of orexin receptor subtypes in peripheral organs indicates discrete peripheral effects of orexins and the existence of a peripheral orexin system. This is supported by the detection of orexin A in rat plasma. Moreover, the sexually dimorphic expression of OX(1) and OX(2) receptors in the hypothalamus, pituitary, and adrenal glands suggests gender-specific roles of orexins in the control of endocrine functions.

Orexin (hypocretin) gene expression in rat ependymal cells

The expression of prepro-orexin (PPO) mRNA in the rat brain was investigated by in situ hybridization histochemistry. In the lateral and posterior hypothalamic areas, which are considered to produce exclusively PPO mRNA, we found high levels of PPO mRNA expressions. We also localized PPO mRNA hybridization signals at lower levels around the lateral ventricles, the third and fourth ventricle. Cellular analysis by emulsion autoradiography revealed the expression of PPO mRNA in the ependymal cell layer. Our results demonstrate that beside the lateral and posterior hypothalamus PPO mRNA is expressed in ependymal cells.

D(A) steps and 2D islands of double layer height in the SiGe(001) system

The surfaces of step graded, partially relaxed Si(1-x)Ge(x)/Si(001) buffers were studied by scanning tunneling microscopy. The surface slips along <110> forming the crosshatch pattern, consisting of bunches of D(A) steps of double layer height. The D(A) steps are present in regions of large surface gradients close to the slips, as well as in planar regions between the slips. These regions are also characterized by the appearance of 2D islands of double layer height. The observations can be explained by assuming the strain due to the misfit dislocations to be locally anisotropic. Anisotropic misfit strain and efficient strain relaxation by the ( 2x8) Ge reconstruction were identified as the main factors causing the unusual step structure.

Comparison of the efficacy and tolerability of a paracetamol/codeine fixed-dose combination with tramadol in patients with refractory chronic back pain

Fifty-five patients suffering from refractory chronic back pain took part in a double-blind, multiple-dose, randomised, cross-over study to compare the efficacy and tolerability of a fixed-dose capsule preparation containing 500 mg paracetamol (CAS 103-90-2) and 30 mg codeine phosphate 1/2 H2O (CAS 41444-62-6) (talvosilen forte, test preparation) with a reference capsule preparation containing 50 mg tramadol hydrochloride (CAS 22204-88-2), in a regimen of two capsules 8-hourly. There were two treatment periods of up to 7 days each. Cross-over took place, without washout, at the end of 7 days, or sooner if patients were unable to tolerate the first treatment. The test preparation was at least as efficacious as the reference in the treatment of back pain (81% of patients experienced good or satisfactory pain relief). 81% of patients tolerated the test well compared to only 69% receiving the reference, as per protocol analysis. The results of this study suggest that the test product is at least as efficacious as tramadol in the treatment of patients with refractory chronic back pain, whilst being better tolerated.

Pharmacokinetics and metabolic pattern after intravenous infusion and oral administration to healthy subjects

Meloxicam [4-hydroxy-2-methyl-N-(5-methyl-2-thiazolyl)-2H- 1,2-benzothiazine-3-carboxamide-1,1-dioxide] is a new nonsteroidal antiinflammatory drug belonging to the enolic acid group. In a crossover study, 30 mg 14C-labeled meloxicam was administered to four male healthy volunteers as a short-term infusion and as an oral solution. The objectives of the study were to determine the mode of elimination, the excretion balance, the in vivo binding characteristics to serum proteins, and to investigate the metabolic pattern in plasma, urine, and feces. A comparison of plasma concentration measurements of unchanged drug by a specific HPLC assay and total radioactivity by liquid scintillation counting revealed a very close conformity. Over 90% of the plasma radioactivity was represented by unchanged drug. Its terminal and dominant half-life of elimination from plasma, as determined from plasma and urinary data in this study, ranged from 12 to 17 hr in the volunteers. The serum protein binding of the radioactivity from in vivo samples was very high (99.1-99.7%). The excretion balance was complete after 6 days. Average urinary excretion of 14C-radioactivity accounted for 43% of the dose, with the remainder appearing with the feces. Meloxicam was extensively metabolized, with only traces of the drug appearing unchanged in urine and feces. The main metabolites were formed by hydroxylation and further oxidation of the methyl group of the thiazolyl moiety. In addition, two further metabolites were found, particularly in urine. Altogether, > 95% of the dose excreted could be accounted for by the metabolites identified or the parent compound itself.

Spontaneous perforation of the ureter: a rare complication of urolithiasis

The spontaneous rupture of the ureter is a rare condition. A case of a girl is reported with a spontaneous perforation caused by ureteral and renal calculi. The concomitant urinoma was drained and the ureter splinted with a double-J catheter. The calculi were destroyed by extracorporal piezoelectric lithotripsy without anesthesia.

Congenital intracranial cysts: clinical findings, diagnosis, treatment and follow-up. A multicenter, retrospective long-term evaluation of 72 children

A multicenter, retrospective evaluation of 72 children born between 1973 and 1987 with intracranial cysts was performed: 37 had an arachnoid cyst, 25 a Dandy-Walker malformation and 10 a porencephalic cyst. The following criteria were evaluated: history, clinical findings, diagnostic work-up (neuroradiology, CSF and intracystic pressures), surgical therapy and follow-up (outcome and cyst volumes).

Regulation of insulin-like growth factor I messenger ribonucleic acid levels by serum in cultured rat fibroblasts

Fibroblasts represent one of the in vivo sites of extrahepatic insulin-like growth factor I (IGF-I) production. In this study, cultured fibroblasts prepared from the skin of neonatal rats were used as a model to assess the role of serum in regulating IGF-I messenger RNA (mRNA) levels. IGF-I mRNA, as demonstrated by Northern blot analysis, was present in the cultured fibroblasts, and serum free media which was conditioned by fibroblasts for 20 h contained 108 pg/ml of immunoreactive IGF-I. Fetal calf serum (FCS) decreased steady state IGF-I mRNA levels, as measured by solution hybridization/RNase protection assay, in fibroblasts in a time- and dose-dependent fashion. Incubation of fibroblasts for 18 h in the presence of 0.3%, 0.6%, or 1% FCS decreased IGF-I mRNA levels to 76%, 56%, and 46% of the levels present in control cells which were maintained in serum free media with 0.25% BSA. Maximal inhibition to approximately 20% of control levels was seen with 4-10% FCS. In contrast, basic fibroblast growth factor and beta-actin mRNA levels increased 2- and 4-fold, respectively, with increasing concentrations of FCS. Treatment of the cells with 10 micrograms/ml cycloheximide resulted in partial abrogation of the inhibitory effect of FCS while protein synthesis in the cells was decreased to 6% of control levels. The addition of 2 micrograms/ml of insulin or 15-100 ng/ml of IGF-I to the fibroblasts did not reproduce the inhibitory effect of FCS. Finally, the inhibitory factor(s) present in the FCS was partially removed/inactivated by charcoal stripping or heat inactivating the serum, but delipidation of the FCS by chloroform extraction had no effect on the inhibitory effect of FCS. In summary, FCS contains a factor(s) that decreases IGF-I mRNA levels in cultured fibroblasts in a time- and dose-dependent fashion. The partial abrogation of the inhibitory effect of FCS with cycloheximide treatment suggests that this effect is at least partially dependent upon new protein synthesis. Furthermore, the studies using delipidated, heat-inactivated, and charcoal-stripped serum suggest that the inhibitory factor(s) is a peptide.

[Autologous peripheral stem cell transplantation in children]

19 children between 3 and 23 years underwent 79 leukapheres for collection of blood stem cells. In children suffering from acute lymphoblastic leukemia (ALL), Non Hodgkin's Lymphoma (NHL) and Ewing's Sarcoma (ES) we collected 6.87 x 10(4) CFU-GM/kg (range 2,65-21.7), if collections were started with the first platelet rise. In children with peripheral primitive neuroectodermal tumors (PNET) and neuroblastoma (NBL) we gained only 1.20 x 10(4) CFU-GM/kg (range 0.09-2.24). 17 children received high dose chemoradiotherapy and peripheral stem cell +/- bone marrow rescue. 9 suffered from solid tumors, 8 from hematopoietic malignancies. 9 were transfused with peripheral stem cells only, 8 received bone marrow in addition. Time to reach 0.5 x 10(9)/l granulocytes was very short-median 31 days (12-65), in 4 children receiving more than 5 x 10(4) CFU-GM/kg 12 to 13 days, only. On January 31st, 1989 6/17 children are alive in complete remission after a median observation time of 14.5 months (3-26) after autologous stem cell transfusion, one child is alive in "no remission", 7 died with relapse, 3 died because of infections (2 x aspergillosis, 1 x pseudomonas septicemia). The collection of blood derived stem cells by leukaphereses was well tolerated even in very small children and easily repeatable. With optimal timing high stem cell numbers were obtainable, resulting in a very short duration of posttransplant granulocytopenia.

[Congenital hydrocephalus--an analysis of the course of pregnancy, prenatal studies and labor]

An analysis of the pool of our patients revealed few disturbances during pregnancy. In two cases the malformations were possibly due to drugs. Prenatal sonographic diagnostics were performed in one-third of the cases or documented: in 60% of the investigated cases a hydrocephalus was found, this being only 20% of the whole pool. The major part of the births were performed by Caesarean section, mainly because of a prolongation of the birth directly or indirectly due to the large circumference of the head. The hereditary trait of associated malformations and malformations of the central nervous system was frequent. Therefore, we advocate a better prenatal work-up and a birth by planned Caesarean section.

[Bioequivalence of piracetam following acute administration of an oral solution or two tablet formulations in volunteers]

In an open, non-randomized 3-way cross-over study, the bioavailability of 2-oxo-pyrrolidine-1-acetamide (piracetam, Encetrop) from two solid oral formulations and one liquid formulation was tested in 8 healthy male volunteers. The area under the concentration time curve, which is defined to be a measurement for bioequivalence among the three tested galenic formulations correlated very well with the area under the effect intensity-time curve, which was estimated in the same volunteers using electro-physiological methods. The different methods of estimation of bioequivalence show similarity between both solid galenic formulations, while the liquid form exhibits superiority in respect to the oral solid formulations.

[Cooperative studies in the treatment of acute lymphoblastic leukemia in children in Austria--report of 10 years' experience]

437 children with acute lymphoblastic leukaemia (ALL) have been treated at 9 different institutions in Austria utilizing common protocols and central registration between 1974 and 1984. 227 patients (132 boys and 95 girls, group I) were treated between 1974 and 1980 using 3 consecutive protocols (KMK, O 76, A 78), which were essentially derived from the Memphis studies VII and VIII. Patients with a high risk of relapse were treated according to the LSA 2-L2 protocol. 210 patients (112 boys and 98 girls, group II) were consecutively treated following the BFM protocols 76/79 and 81/83. In this group, treatment intensity was adjusted to the initially determined individual risk of relapse (BFM risk score or risk factor). To date, the life table analysis demonstrates that the probability of continuous complete remission for patients in group II is 60% after 5 and 3 years (BFM 76/79 and BFM 81/83, respectively), whereas group I reaches a level of 37.3%. The prognostic difference between risk and non-risk patients in both studies of group II was eliminated. Despite a higher morbidity and non-leukaemia-related mortality in group II, the therapeutic success can be attributed to the intensification of induction therapy.