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.

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.

[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.

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.

Transorbital penetrating brain injury caused by a toy arrow: a case report.

A case of a 9-year-old boy with a transorbital toy-arrow injury to the brain is presented. At admission he was in coma (Glasgow Coma Scale of 6) with right hemiparesis and had a completely prolapsed left eye. Computerized tomography revealed intracranial haemorrhage and fracture of the orbital wall, which were treated conservatively. His left eye was enucleated due to massive injury. At the 6-month check-up the boy still show neurological signs of latent right hemiparesis. Disturbances, mostly cognitive, were noted on his psychological tests. A survey of the literature reveals no report of this nature in the paediatric age group. The necessity of continuous monitoring of new environmental risks as they occur, and the requirement for the prevention of recreational brain injuries in children, is stressed.

Showdown time.

There may not be a train wreck this fall, but that doesn't mean that there won't be some close calls as the White House and Congress come to grips on such issues as spending and taxes, health care, welfare and the environment.

Healing segmental femoral defects in sheep using recombinant human bone morphogenetic protein.

A middiaphyseal, 2.5-cm osteoperiosteal segmental defect stabilized by plate fixation was created in the right femur of 17 sheep. Four treatment groups were included: Group I, no implant; Group II, inactive bone matrix; Group III, recombinant human bone morphogenetic protein (rhBMP-2) mixed with inactive bone matrix; and Group IV, autogeneic bone graft. Three animals had early failure of fixation, and the remaining 14 were evaluated at three months after implantation. Radiographs showed bony union of all defects treated with rhBMP-2 (six) and a lack of bony union in the negative-control groups treated with no implant (three) and inactive bone matrix without BMP (three). Both defects treated with autograft healed. New bone formation in the defect sites treated with rhBMP-2 first appeared one month after implantation and had a mean bending strength (expressed as a percentage of the contralateral femur) of 91% +/- 59% (mean +/- standard deviation) for defects treated with BMP-2, 77% +/- 34% for autograft, 9% +/- 8% for no implant, and 11% +/- 7% for inactive matrix without BMP. Three sheep treated with rhBMP-2 had their fixation plates removed at four months and were followed for one year. Their bone defect sites remained solidly healed one year after the initial operation.

[The impact of psychological stress on somatic and biochemical parameters in an atypical sports discipline]. / Odraz psychického zatazenia na niektoré somatické a biochemické parametre u atypického sportového odvetvia.

The subject of our interest was to investigate the response of the organism to mental strain in an atypical sports discipline. To this end we examined 10 chess players. We assessed their pulse rate at rest, before a contest, immediately after the contest and after 5 mins. recovery. Statistical evaluation revealed an increased heart rate before the contest, as compared with rest at a level of significance of 0.01; after the contest as compared with the status before the contest at a level of 0.02; in the recovery stage, as compared with rest, at the 0.01 level. As a control group we examined 10 hockey players under the same conditions and the results were compared with the chess players. For scientific practice it is necessary to find a way to monitor the internal environment during a chess game (catecholamines, lactate, glucose, fatty acids, cholesterol and others). As soon as this will be possible without disturbing the reflection process of the chess player, we shall be able to obtain more information on the adaptation of the organism to mental strain during a game of chess.

[Benign paroxysmal vertigo in children]. / Benigna paroksizmalna vrtoglavica u djece.

Based on our examination of 176 patients, we first selected, according to the general standards of diagnosing benign paroxysmal vertigo of childhood (children aged up to ten years, paroxysmal vertigo, ataxia) a group of 78 patients. Using multidisciplinary approach we have thus performed in these children the following examinations: an exhaustive anamnesis, laboratory examinations, clinical ORL (ENT), ophthalmological, neuropediatric examinations, x-ray of the cranium and the temporal bone, audiometric, vestibulogenic and EEG examinations. In the following stage we have, on the basis of the obtained data, selected 22 patients who met the restrictive standards for the diagnosis of a benign paroxysmal vertigo of childhood (typical clinical picture, isolated vestibular symptomatology, exclusion of the etiological factors, benign course of the disease). In our material the age range was between the second and the sixth year. After the sixth year of age we have not had any case of benign paroxysmal vertigo. We have not arrived at any significant fact which would indicate an etiological factor. There is no significant difference in the frequency of the disease between the two sexes, but we may assert that small girls slightly prevail. Normal psychomotoric development, normal intellectual faculties, absence of risk factors (only a twin had lower birth weight), absence of neurological abnormalities, regular EEG findings, pathological findings of the vestibular excitability together with absence of cochlear symptomatology, and evident clinical symptoms obviously indicate the right diagnosis. The evolution of the disease is exceptionally favorable.(ABSTRACT TRUNCATED AT 250 WORDS)

Purification and characterization of other distinct bone-inducing factors.

We purified a factor that induces bone formation greater than 300,000-fold from guanidinium chloride extracts of demineralized bone. Fifty nanograms of highly purified protein was active in an in vivo cartilage and bone-formation assay. The activity resided in a single gel band, corresponding to a molecular mass of approximately 30 kDa, which yielded proteins of 30, 18, and 16 kDa on reduction. The partial amino acid sequence obtained from these proteins confirmed our identification of specific factors that induce new bone formation in vivo.

Antigen-induced changes in phospholipid metabolism in antigen-binding B lymphocytes.

Previous studies have demonstrated a marked change in the metabolism of phospholipids (PL) after activation of resting B lymphocytes with anti-immunoglobulin (anti-Ig). In this study we examined PL metabolism in highly purified trinitrophenyl (TNP)-binding B cells after their activation with various forms of TNP-carrier protein. Such cells show similar changes in PL metabolism when stimulated with either antigen or anti-Ig, i.e., increased incorporation of 32PO4 into phosphatidic acid and phosphatidyl inositol (PI) but not phosphatidyl choline, phosphatidyl ethanolamine, or phosphatidyl serine. We have demonstrated that these responses to antigen are TNP-specific and dose-related between 1 and 50 micrograms/ml, producing up to a 2.5-fold stimulation of 32PO4 incorporation into PI. The PL response is also directly related to the density of TNP on the carrier and can be augmented by additional cross-linking of the carrier protein. These data suggest that cross-linking of surface Ig by antigen induces a change in PL metabolism as an early event in B cell activation.

Novel prolactin related mRNAs in rat pituitary cells.

From cytoplasm of rat pituitary GH4C1 tumour cells, anti prolactin anti-serum precipitates a polypeptide with apparent molecular weight of 75.000 in addition to prolactin. In vitro translation of size fractionated RNA shows that a 82.000 molecular weight PRL-like polypeptide is encoded by a mRNA larger than the 1 kb prolactin mRNA. Northern blot analysis shows that a rat prolactin cDNA probe hybridize to a 3.2 kb RNA and a 1.5 kb RNA in addition to the 1 kb PRL mRNA. The 82.000 molecular weight translation product and the 3.2 kb mRNA is also detected in rat anterior pituitary cytoplasm. We conclude that at least one high molecular weight mRNA which code for a prolactin-like polypeptide, is present in normal rat anterior pituitary gland and in GH4C1 cells.

Changes in phospholipid metabolism during B lymphocyte activation.

We have examined phospholipid metabolism in murine B lymphocytes stimulated with anti-Ig bound to Sepharose. T cell-depleted splenic B lymphocytes cultured with Sepharose-coupled, affinity-purified goat anti-mouse Ig (GAMIg) increased the incorporation of 32PO4 into phosphatidic acid and phosphatidylinositol within 3 hr and increased [3H]-thymidine uptake at 48 hr. No increase in labeling was observed in phosphatidylethanolamine, phosphatidylcholine, or phosphatidylserine. Based on both negative and positive selection procedures, it was demonstrated that these responses occurred in B lymphocytes. In contrast to the thymidine uptake response of the GAMIg-stimulated B lymphocytes, the phospholipid response did not require the presence of accessory cells or exogenous cytokines. The same selective changes in phospholipid metabolism were observed in neoplastic B lymphocytes (BCL1) after treatment with Sepharose anti-mu, but not with Sepharose anti-Ia or Sepharose normal Ig. The dose-response relationships of 32PO4 incorporation into phosphatidic acid and phosphatidylinositol and [3H] thymidine uptake were nearly identical in BCL1 cells. The results of these experiments indicate that interaction of B lymphocytes with insolubilized anti-Ig results in prompt and selective changes in phospholipid metabolism that appear to be correlated with B lymphocyte proliferation.