Gonadotrophin and prolactin secretory dynamics in girls with normal puberty, idiopathic precocious puberty and precocious puberty due to hypothalamic hamartoma

OBJECTIVE: This study was designed to test the hypothesis that hypothalamic hamartoma causes precocious puberty through a different neuroendocrine mechanism than that of normal puberty or of idiopathic precocious puberty. DESIGN AND PATIENTS: We compared the pattern of gonadotrophin secretion among 4 girls with precocious puberty due to hypothalamic hamartoma, 27 girls with idiopathic precocious puberty, and 14 girls with normal puberty. All subjects were breast stage 3 or 4. Blood samples were obtained every 20 min for 4 h during the day (1.000 hours to 1400 h) and night (22.00 hours to 0200 h). MEASUREMENTS: LH, FSH, and prolactin were measured in each blood sample. Girls also underwent LHRH-stimulation with measurement of LH and FSH before and after stimulation. RESULTS: There were no significant differences in mean LH level, LH peak amplitude, or LH or FSH peak frequency during either the day or the night among the three diagnostic groups. However, the mean +/- SD LHRH-stimulated peak LH levels were greater in girls with hypothalamic hamartoma than in girls with normal puberty or with idiopathic precocious puberty (194 +/- 142 vs 85 +/- 60 or 66 +/- 54 IU/l, respectively, P < 0.05). The LHRH-stimulated peak FSH level in girls with hypothalamic hamartoma exceeded the level for the normal pubertal girls (31 +/- 19 vs 17 +/- 7 IU/l, P < 0.05), but not the level for the girls with idiopathic precocious puberty (25 + 12 IU/l). The peak LH to peak FSH ratio in the girls with hypothalamic hamartoma exceeded the ratio for the girls with idiopathic precocious puberty (7.3 +/- 3.9 vs 2.6 +/- 3.0 IU/l, P < 0.05), but not the ratio for the normal pubertal girls (5.0 + 2.9). There were no significant differences in mean prolactin level, peak amplitude or frequency, or in the ratio of mean night to mean day prolactin, among the 3 diagnostic groups. CONCLUSIONS: We conclude that spontaneous gonadotrophin and prolactin secretion are similar among girls with hypothalamic hamartoma, idiopathic precocious puberty, or normal puberty. However, the increased LHRH-stimulated peak LH in the girls with hypothalamic hamartoma suggests subtle differences in neuroendocrine regulation that may underlie their more rapid pubertal maturation.     

A fatal, systemic mitochondrial disease with decreased mitochondrial enzyme activities, abnormal ultrastructure of the mitochondria and deficiency of heat shock protein 60

We report on a girl presenting with facial dysmorphic features and breathing difficulties upon birth. She was hypotonic, developed a metabolic acidosis, and died two days old of heart failure. Post-mortem examination revealed abnormalities of brain, lungs, heart and liver. In cultured skin fibroblasts activities of enzymes of oxidative phosphorylation, pyruvate metabolism, beta-oxidation and other mitochondrial (mt) metabolic pathways were markedly decreased. Activities of enzymes localized in the mt outer membrane or in other cell organelles were found to be normal. The mitochondria appeared swollen and were located mainly around the nucleus. Electron micrographs showed locally disintegrated mt inner membranes and large mt vacuoles. The amount of mt heat shock protein 60 (hsp60) was about one fifth of that in controls. We conclude that this mt disorder is most likely caused by defective synthesis and maintenance of mitochondria, possibly due to a defect in mt protein import or enzyme assembly resulting from deficiency of hsp60.     

Calcium uptake via endocytosis with rapid release from acidifying endosomes

A number of specific cellular Ca2+ uptake pathways have been described in many different cell types [1] [2] [3]. The possibility that substantial quantities of Ca2+ could be imported via endocytosis has essentially been ignored, although it has been recognized that endosomes can store Ca2+ [4] [5]. Exocrine cells can release significant amounts of Ca2+ via exocytosis [6], so we have investigated the fate of Ca2+ taken up via endocytosis into endosomes. Ca2+-sensitive and H+-sensitive fluorescent probes were placed in the extracellular solution and subsequently taken up into fibroblasts by endocytosis. Confocal microscopy was used to assess the distribution of fluorescence intensity. Ca2+ taken up by endocytosis was lost from the endosomes within a few minutes, over the same period as endosomal acidification took place. The acidification was inhibited by reducing the extracellular Ca2+ concentration, and Ca2+ loss from the endosomes was blocked by bafilomycin (100 nM), a specific inhibitor of the vacuolar proton ATPase. Quantitative evaluation indicated that endocytosis causes substantial import of Ca2+ because of rapid loss from early endosomes.     

"Asymptomatic" primary hyperparathyroidism: is parathyroidectomy indicated?

OBJECTIVE: We assessed the efficacy of magnetization transfer contrast (MTC) imaging of the cervical spine in conjunction with a gradient recalled echo (GRE) technique using a 0.3 T permanent magnet imager. MATERIALS AND METHODS: Seventy patients were prospectively investigated. Multislice sagittal and axial images of the cervical spine with and without MTC were obtained using a GRE sequence (TR/TE/flip angle = 750 ms/23 ms/25 degrees). The contrast-to-noise ratios (C/Ns) for CSF versus cord or disk were calculated for quantitative analysis. Qualitative image analysis was also performed. RESULTS: Both sagittal and axial MTC images had significantly higher C/N values than conventional GRE images. The MTC images showed better differentiation between the CSF and the cord or thecal sac as well as better delineation of the nerve roots. Furthermore, MTC images demonstrated syringomyelia more clearly than conventional images. CONCLUSION: Magnetization transfer contrast images at 0.3 T are effective for diagnosing diseases of the cervical spine.     

Large-scale use of liquid-phase blocking sandwich ELISA for the evaluation of protective immunity against aphthovirus in cattle vaccinated with oil-adjuvanted vaccines in Argentina

Specific serum activity levels against four reference strains of foot-and-mouth disease virus (FMDV) were evaluated from 1634 animals vaccinated with commercial quadrivalent oil vaccines and from 746 unvaccinated, naive animals, using the liquid-phase blocking sandwich ELISA (lpELISA) test. Cows from the FMDV-free area of Argentina were tested for the absence of specific FMDV antibodies (sp FMDV Abs) and those showing lpELISA titres < 1.0 were grouped in lots of 16 animals. They were vaccinated and challenged at 90 days postvaccination (DPV) with one of four virus strains used for vaccine production and control (prototype strains). Serum samples from vaccinated and control cattle were collected 60 and 90 DPV and the level of sp FMDV Abs was determined by lpELISA. Animals were examined for clinical signs of disease. Results show that serum lpELISA titre levels directly correlate with the percentage of protected animals. It was seen that 100, 98, 93 and 87% of the vaccinated cattle with antibody titre levels > or = 2.1 were protected against challenge with serotypes C85, A87,01 Cas and A79, respectively. Evidence is also presented of seroconversion in a sample of 3-5-month-old calves vaccinated in the field, showing lpELISA titres compatible with protection against the four vaccine viruses as long as 150 DPV. Results reported in this paper strongly support the use of the lpELISA test for a rapid and reliable evaluation of the efficacy of FMDV commercial vaccines as well as for the assessment of the immunological status of cattle in FMDV-free and enzootic regions of South America.     

Immobilized Condensed Tannins and Their Interaction with Proteins

Condensed tannins from grapes immobilized on Sepharose 4B were found to have protein binding properties similar to tannins in free solution. Proteins bound to the gel at pH values below their individual isoelectric points and were eluted when the pH was increased. A good correlation was obtained between the isoelectric point and the elution pH for the following enzymes and proteins: alkaline phosphatase, ovalbumin, β-lactoglobulin, bovine serum albumin, α-amylase,γ-globulin, and cytochrome c. Trypsin represented an exception to the rule, α-Amylase retained enzymatic activity after elution from the gel.     

Taxonomic aspects of strains from Patagonia and type strains of Desulfovibrio

Fourteen type strains and 42 indigenous strains of Desulfovibrio were studied and taxonomic numeric methods were applied (Cluster Analysis, Principal Coordinates Analysis, Correspondence Analysis). The type strains as well as the indigenous ones share a low quantity of carbon and energy sources. Type strains have a taxonomic structure which shows net clusters; indigenous strains possess a grading (or "adjustment") in their positive reactions hence the taxonomic structure is not so clear. Both classifications are firm since they suffer minimal changes when they are joined.     

Prion protein expression in Chinese hamster ovary cells using a glutamine synthetase selection and amplification system

Syrian hamster prion protein (PrPC) and a truncated Syrian hamster prion protein lacking the glycosylphosphatidylinositol (GPI) anchor C- terminal signal sequence (GPI-) were expressed in Chinese hamster ovary cells using a glutamine synthetase selection and amplification system. The CHO cell clones expressing the GPI- PrP secreted the majority of the protein into the media, whereas most of the PrP produced by clones expressing the full-length protein with the GPI anchor was located on the cell surface, as demonstrated by its release upon treatment with phosphatidylinositol-specific phospholipase C (PIPLC). A cell clone that expressed the highest levels of full length PrP was subcloned to obtain clone 30C3-1. PrP from clone 30C3-1 was shown to be sensitive to proteolysis by proteinase K and to react with monoclonal and polyclonal antibodies that recognize native PrPC. The recombinant PrP migrated as a diffuse band of 19-40 kDa but removal of the N-linked oligosaccharides with peptide N-glycosidase F (PNGase F) revealed three protein species of 19, 17 and 15 kDa. The 19 kDa band corresponding to deglycosylated full-length PrP was quantified and found to be expressed at a level approximately 14-fold higher than that of PrPC found in Syrian hamster brain.      

Effect of Forming and Aging Atmospheres on E-Glass Strength

E-glass fibers were drawn in various atmospheres. The specific surface area measured by water vapor adsorption was larger than the geometric area. Specific surface increases with the square root of drawing gas pressure. Exposure of glass fibers to ambient atmosphere decreases the strength and increases the area of macropores (r_p> 100 Å). The reciprocal strength of E-glass filaments aged at ambient humidity for various times is proportional to the square root of macro pore area. This relation is independent of the drawing atmosphere, at least for water and tetrafluoromethane.