Nucleation of Ga droplets on Si and SiOx surfaces.

We report on gallium droplet nucleation on silicon (100) substrates with and without the presence of the native oxide. The gallium deposition is carried out under ultra-high vacuum conditions at temperatures between 580 and 630 °C. The total droplet volume, obtained from a fit to the diameter-density relation, is used for sample analysis on clean silicon surfaces. Through a variation of the 2D equivalent Ga thickness, the droplet diameter was found to be between 250-1000 nm. Longer annealing times resulted in a decrease of the total droplet volume. Substrate temperatures of 630 °C and above led to Ga etching into the Si substrates and caused Si precipitation around the droplets. In contrast, we obtained an almost constant diameter distribution around 75 nm over a density range of more than two orders of magnitude in the presence of a native oxide layer. Furthermore, the droplet nucleation was found to correlate with the density of surface features on the 'epi-ready' wafer.

Targeted disruption of mouse fibroblast activation protein.

Human fibroblast activation protein (FAP), a member of the serine prolyl oligopeptidase family, is a type II cell surface glycoprotein selectively expressed by fibroblastic cells in areas of active tissue remodeling, such as the embryonic mesenchyme, areas of wound healing, the gravid uterus, and the reactive stroma of epithelial cancers. Homologues of FAP have been identified in the mouse and Xenopus laevis. FAP is a dual-specificity enzyme that acts as a dipeptidyl peptidase and collagenase in vitro. To explore the role of FAP in vivo, Fap(-/-) mice were generated by homologous recombination. RNase protection analysis and reverse transcription-PCR confirmed the absence of full-length Fap transcripts in mouse embryonic tissues. No FAP protein was detected in Fap(-/-) animals by immunohistochemistry, and no FAP-specific dipeptidyl peptidase activity was found. We report that Fap(-/-) mice are fertile, show no overt developmental defects, and have no general change in cancer susceptibility.

Expression of the fibroblast activation protein during mouse embryo development.

Human Fibroblast Activation Protein (FAP), a member of the serine prolyl oligopeptidase family, is a type II cell surface glycoprotein that acts as a dual-specificity dipeptidyl-peptidase (DPP) and collagenase in vitro. Its restricted expression pattern in embryonic mesenchyme, in wound healing and in reactive stromal fibroblasts of epithelial cancers, has suggested a role for the FAP protease in extracellular matrix degradation or growth factor activation in sites of tissue remodeling. The FAP homologue in Xenopus laevis has been reported to be induced in the thyroid hormone-induced tail resorption program during tadpole metamorphosis supporting a role for FAP in tissue remodeling processes during embryonic development. However, Fap-deficient mice show no overt developmental defects and are viable. To study the expression of FAP during mouse embryogenesis, a second Fap-deficient mouse strain expressing beta-Galactosidase under the control of the Fap promoter was generated by homologous recombination (Fap-/- lacZ mice). FAP deficiency was confirmed by the absence of FAP-specific dipeptidyl-peptidase activity in detergent-soluble extracts isolated from 17.5 d.p.c. Fap-/- lacZ embryos. We report that Fap-/- lacZ mice express beta-Galactosidase at regions of active tissue remodeling during embryogenesis including somites and perichondrial mesenchyme from cartilage primordia.

Effects of prostaglandins on prolactin and growth hormone synthesis and secretion in cultured rat pituitary cells.

The effects of prostaglandins E1, E2, F1alpha, and F2alpha on prolactin and growth hormone synthesis and secretion were studied in cultured rat pituitary cells. Total extracellular accumulation of prolactin was measured by radioimmunoassay. When hormone synthesis was studied, the cells were cultured in the presence of [3H]leucine for the last hour of each treatment period. The intra- and extracellular radioactive hormones were determined in the same microsample by a specific and quantitative immunoprecipitation method, employing polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulphate. The results show that all prostaglandins stimulated the extracellular accumulation of prolactin at 3-30 nM. Prostaglandin E1 was more effective in stimulating extracellular accumulation of prolactin than prostaglandin E2 and the F compounds. Prostaglandin F2alpha at 3 nM doubled the rate of prolactin synthesis, but had no effect on growth hormone or total cell protein synthesis after 24 h of treatment. The first effect of prostaglandin F2alpha was observed after 5 h of incubation, and the time-course of effect on prolactin synthesis was similar to that of thyrotropin-releasing hormone.

Measurements of prolactin and growth hormone synthesis and secretion by rat pituitary cells in culture.

A specific and sensitive immunoprecipitation method for measurements of biosynthesized radioactive prolactin and growth hormone is described. Antisera to rat prolactin and growth hormone were developed in the rabbit and monkey, respectively. The specificity of the immune sera was assessed by polyacylamide gel electrophoresis of the dissolved immunoprecipitates. The two antisera showed cross-reactions with the nonhomologous hormone of less than 1%. Separation of tritium-labelled prolactin and growth hormone by immunoprecipitation, followed by polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulphate was shown to be 95-57% complete. When both hormones were measured in the same microsample by sequential immunoprecipitation, the reaction was 97% complete for determination of intra- and extracellular prolactin and extracellular growth hormone, but 85% complete for determination of intracellular growth hormone. This method has been used to characterize the basal synthesis and secretion of prolactin and growth hormone in three different but related, pituitary cell strains. Radioactive prolactin and growth hormone was obtained from monolayer cultures when the cells were grown in the presence of [3H]L-leucine. The rate of prolactin synthesis and extracellular accumulation was higher than that of growth hormone in a cell strain which produced both hormones. In these cells prolactin synthesis represents 1-5%, and growth hormone 0.1-0.6% of total protein synthesis.

Relationship between stimulated prolactin release from GH cells and cyclic AMP degradation and formation.

We have studied the relationship between the prolaction (PRL) release induced by thyroliberin (TRH) and theophylline and the formation and inactivation of adenosine 3', 5'-cyclic monophosphate (cyclic AMP) in cultured rat-pituitary cells (GH3 cells). TRH, which stimulated prolactin release, increased cyclic AMP formation and stimulated transiently both the low- and high-Km cyclic phosphodiesterases. The maximal effect on the phosphodiesterase was observed at 30 mM TRH. The stimulatory effect of TRH on the activity of the cyclic AMP phosphodiesterases was duplicated by incubation of the cells with cyclic AMP (2-10 mM). In washed particulate GH3 cell fractions, TRH increased the adenylyl cyclase activity up to 180%. Treatment of GH3 cells with theophylline stimulated the release of PRL and inhibited cyclic AMP degradation probably leading to the measured increase in cellular concentrations of the nucleotide. The effects of TRH and theophylline on cellular cyclic AMP concentrations and on PRL release were additive. There was a positive correlation between PRL release and cellular cyclic AMP concentration (r = 0.97). The elevations observed in cellular cyclic AMP concentration after TRH treatment are due to increased formation which in turn leads to phosphodiesterase activation. Therefore, cyclic AMP formation appears to be an intermediary step in the stimulus-secretion coupling caused by the tripeptide.

[Epilepsy with centrotemporal (Rolandic) spikes. A peculiar seizure disorder of childhood]. / Padaczka z obecnoscia wyladowan iglicowych w okolicy centrosrodkowej (pole Rolando). Szczególna postac drgawek w dziecinstwie.

The study presents the results of a long term investigation of 60 epileptic children with Rolandic (centrotemporal) spikes in EEG. The results could be summarized as follows: the Rolandic epilepsy is relatively frequent entity (13.4% of the total number of epileptic children). The age span was from 3--13 years, with a peak of age incidence between the 7th and 8th year of life. More than half of children had nocturnal fits only. From the clinical point of view 60% of children had generalized crises, and the remaining 40% had partial attacks corresponding to the functional organization of the Rolandic cortical area. The evolution of the Rolandic epilepsy in childhood is favourable. More than 50% didn't have more attacks after the introduction of antiepileptic therapy, and 3/4 of them could be classified as practically cured after an long-term follow-up (criterion: an attack-free period of at least 5 years. Finally, in more than 80% of cases after three years of follow-up the spikes have disappeared from the EEG tracings which were completely normal.

[Carcinoma in situ in the urinary bladder]. / Karcinom in situ mokracnog mjehura.

In this paper we have presented seven patients with carcinoma in situ of the urinary bladder, a rare intraepithelial form of transitional cell carcinoma of the urinary bladder, described first in 1952. In all patients malignant cells were detected in urine sediment, and the diagnosis was proven histopathologicaly by random biopsies of the urinary bladder. In five patients carcinoma in situ was associated with papillary bladder tumor, while two patients had primary carcinoma in situ. We have emphasized a high rate of irritative urinary symptoms, that can lead to diagnostic mistakes. Three patients had reduced bladder capacity. In all patients a complete response was achieved after local immunotherapy or local chemotherapy. After a follow-up lasting from 23 to 61 months in one patient a recurrent carcinoma in situ was diagnosed, while six patients show no signs of recurrent disease.

Subarachnoid block after a "top-up" dose during continuous segmental epidural analgesia in labour. A case report.

We describe a case of spinal block which developed after a second "top-up" of local anaesthetic during segmental epidural analgesia in labour. The incidence of similar cases is reviewed. The importance of aspiration and the injection of a "test" dose before every "top-up" is stressed.

[Epidural analgesia--effect on the fetus and uterine activity]. / Epiduralna analgezija u porodaju--utjecaj na plod i aktivnost uterusa.

The effect of continuous epidural analgesia on the fetus, newborn, and uterine activity was studied in a group of 50 parturients. No untoward effects, either in the fetus or uterine activity, that could be ascribed to this procedure, were observed. The authors use their own modicifation of the epidural block by titrating the amount of the local anesthetic according to the intensity of pain in labour.

[The effect of epidural analgesia in labour upon serum catecholamine levels]. / Ucinak epiduralne analgezije u porodaju na razinu kateholamina u serumu.

The serum levels of catecholamines were determined in 26 healthy parturients. Epidural analgesia was given in 13 cases, while the remaining women were given classic parenteral analgesia and served as controls. The blood samples were taken before analgesia and after delivery and also from the clamped umbilical vein from the newborn after delivery. There was a statistically significant decrease of catecholamine levels in the epidural group and a slight increase in the control group. There were no differences among the newborns.

Hypoxia-induced pulmonary vasoconstriction: effects of fentanyl following different routes of administration.

Recent investigations have revealed that intravenous anesthetics, including fentanyl, do not reduce the pulmonary vasoconstrictor response to alveolar hypoxia. In contrast, the response is markedly reduced or abolished by inhalation anesthetics. Recent investigations have demonstrated that the route of administration is of importance. Halothane, which inhibits the response when administered via the airways, behaves more like an intravenous anesthetic following administration via the blood stream, provided the alveolar concentration has been kept low (Bjertnaes et al. 1977). It was therefore a distinct possibility that the lack of any damping effect of fentanyl on the response could be due to the route of administration rather than to a different pharmacological property. We have tested this hypothesis by introducing fentanyl in nebulized form via the airways in one group of isolated rat lungs, and via the blood stream in another group. We found, however, no effect of fentanyl on the pulmonary vasoconstrictor response to hypoxia, regardless of the route of administration. Plasma concentrations of fentanyl were determined by radioimmunoassay and compared with those encountered in anesthetic practice.