Cerebrospinal fluid purine metabolites after complex febrile convulsions

Adenosine monophosphate, inosine monophosphate, inosine, adenosine, guanosine, adenine, guanine, hypoxanthine, xanthine and uric acid were determined in cerebrospinal fluid (CSF) of 15 children after complex febrile seizures (CFS) and in 27 after simple febrile seizures (SFS), and compared with those in a control group of 63 children. There was no statistically significant difference between the groups for any of these metabolites, suggesting that CFS and SFS neither significantly disturb the metabolism of nucleotides, nucleosides or bases nor significantly deplete neuron adenosine triphosphate levels.     

Total Parathyroidectomy With Autotransplantation in Haemodialysed Patients With Secondary Hyperparathyroidism--Should It Be Abandoned?

The development of secondary hyperparathyroidism is almost universalin patients with end-stage renal disease. Medical managementfrequently fails and in such circumstances parathyroidectomybecomes a necessity. Total parathyroidectomy with autotransplantationof parathyroid tissue into the patient's forearm has been advocatedas the surgical procedure of choice. In a previous publicationwe reported our experience with this technique in six haemodialysedpatients. We now extend our follow-up to 19 patients over anobservation period ranging from 6 to 66 months. Five of thesepatients required graft removal because of recurrent secondaryhyperparathyroidism. Despite total graft removal, two patientshad clinical and laboratory evidence of persistent hyperparathyroidism.Histology of the removed graft tissue demonstrated severe hyperplasiaas well as invasion of adjacent muscle, adipose tissue, andvascular channels by parathyroid cells. This raises the possibilityof local and distant metastatic spread of parathyroid tissueresulting in hyperparathyroidism. We suggest that parathyroidautotransplantation is potentially hazardous and should in factbe abandoned.     

Release of vesicular noradrenaline in the rat tail artery induced by cocaine

Summary The effects of cocaine on overflows of endogenous noradrenaline and DOPEG from isolated rat tail arteries were examined. 1. Both overflows increased progressively with increasing concentration of cocaine, while the (NA overflow)/(DOPEG overflow) ratio first increased and then decreased. The changes in the overflows induced by cocaine (0.1 mmol/l) appeared reversible. 2. Exposure of the tissue for 30 min to cocaine, 1 mmol/l, resulted in a significant decrease in the proportion of storage vesicles containing electron-dense cores. 3. The changes in overflows of noradrenaline and DOPEG induced by cocaine (0.1 mmol/l) were unaffected by the presence of desipramine (0.1 mol/l) or removal of extracellular Ca²⁺. The effect of cocaine on the overflow of noradrenaline was potentiated by prior inhibition of MAO with clorgyline. 4. Exposure of segments to a Ca²⁺-free, high K, low Na incubation medium was accompanied by increased overflow of noradrenaline. Cocaine (0.1 mmol/l) reduced the overflow of noradrenaline to about a half, and substantially increased the overflow of DOPEG. 5. The increase in the overflow of DOPEG from segments bathed in HEPES-buffered solutions, the pH of which ranged from 6.80 to 7.38, was approximately proportional to the calculated concentration of unprotonated (uncharged) cocaine. 6. Quantitatively similar changes in the overflows were observed when norcocaine was substituted for cocaine. Ecgonine methyl ester was much less potent than cocaine, and O-benzoyl ecgonine was ineffective. 7. The small increases in the overflow of noradrenaline observed at relatively low concentration (<30 mol/l) of cocaine can be attributed primarily to inhibition of reuptake of the released transmitter by the cocaine- and desipramine-sensitive amine carrier. The overflows of NA and DOPEG in the presence of higher concentrations of the alkaloid exhibit features compatible with the following hypothesis: (A) Cocaine is translocated across the axonal membrane mainly in the form of the unprotonated species, a large fraction of which is reprotonated upon the entry into the axon. (B) Cocaine releases noradrenaline from storage vesicles into the extravesicular space, where the bulk of the amine is converted to DOPEG. (C) Efflux of the remaining noradrenaline from the axon is not mediated by the Na⁺-dependent, cocaine- and desipramine-sensitive neuronal amine carrier. It seems to represent uncoupled efflux of the protonated form of noradrenaline.Abbreviations DOPEG 3,4-dihydroxyphenylethylene glycol - DOMA 3,4-dihydroxymandelic acid - HEPES N-(2-hydroxyethyl)piperazine-N-ethanesulfonic acid - MAO monoamine oxidase - MOPEG 3-methoxy-4-hydroxyphenylethylene glycol - NA (–)noradrenaline - pH_j pH in the extravesicular space of the axon - pH_o pH of the bathing solution - pK_a negative logarithm of the dissociation constant This study was supported by the British Columbia Heart Foundation Send of fprint requests to V. Palaty at the above address     

In vivo and in vitro studies of the site of inhibitory action of omeprazole on adrenocortical steroidogenesis

Summary The site of omeprazole inhibition of adrenal steroidogenesis has been sought in vivo by analyzing the patterns of urinary steroid metabolite excretion after 6 days of treatment with placebo/omeprazole.Excretion rates of androsterone, aetiocholanolone, dehydroepiandrosterone, 11 hydroxyandrosterone, tetrahydrocortisone, tetrahydrocortisol and cortolone were reduced, indicating a block at an early step in steroidogenesis, possibly cholesterol side-chain cleavage. In vitro studies have confirmed this finding by measuring conversion of added precursors to cortisol in isolated bovine adrenocortical cells. Cortisol synthesis from added 20 hydroxycholesterol was inhibited by 83% in the presence of 100 µg omeprazole/ml. Conversion from pregnenolone and progesterone and their 17 hydroxylated derivatives was inhibited by 20–40% whereas cortisol production from added 11 deoxycortisol was not affected.These data suggest that omeprazole primarily inhibits cholesterol cleavage and does not inhibit 3 hydroxysteroid dehydrogenase, 17 hydroxylase or 11 hydroxylation; 21 hydroxylase activity may be marginally attenuated.     

Sequence analysis of L RNA of Lassa virus

The L RNA of three Lassa virus strains originating from Nigeria, Ghana/Ivory Coast, and Sierra Leone was sequenced and the data subjected to structure predictions and phylogenetic analyses. The L gene products had 2218-2221 residues, diverged by 18% at the amino acid level, and contained several conserved regions. Only one region of 504 residues (positions 1043-1546) could be assigned a function, namely that of an RNA polymerase. Secondary structure predictions suggest that this domain is very similar to RNA-dependent RNA polymerases of known structure encoded by plus-strand RNA viruses, permitting a model to be built. Outside the polymerase region, there is little structural data, except for regions of strong alpha-helical content and probably a coiled-coil domain at the N terminus. No evidence for reassortment or recombination during Lassa virus evolution was found. The secondary structure-assisted alignment of the RNA polymerase region permitted a reliable reconstruction of the phylogeny of all negative-strand RNA viruses, indicating that Arenaviridae are most closely related to Nairoviruses. In conclusion, the data provide a basis for structural and functional characterization of the Lassa virus L protein and reveal new insights into the phylogeny of negative-strand RNA viruses.     

香港与澳门中小学学校辅导发展的比较

目的 探讨香港与澳门两地中小学学校辅导的发展，就辅导工作的内容、开展情况、辅导人员在建设上的差别以及发展速度相异的原因等方面作分析。方法 本研究以香港及澳门中小学的学校辅导员／社工为调查对象，利用自编问卷方式进行调查．结果 （1）两地的辅导员都一致认为，通过学校辅导服务可以帮助中学生建立良好的社交行为及人际关系，（2）两地的中小学都在帮助学生更好地接纳他人及尊重他人这个项目上都做得较好；（3）两地的中小学校辅导的目标不再是以处理学生的偏差行为为主，转而注重学生的个人潜能发展；（4）就课堂辅导活动开展的情况来看，香港在班级辅导、全年级辅导及全校性辅导方面都做得比较好，而澳门的全校性辅导通有待加强。至于课堂以外的辅导活动，两地均以个别晤谈，团体辅导、心理卫生讲座以及工作坊等方式开展辅导活动为多。（5）在持介制度上，香港中小学都做得比较完善；（6）咨询服务方面，香港小学做得较多，而澳门则是中学做得较多；（7）新生适应服务方面，香港较澳门做得较多；（8）香港的学校比澳门学校更多地与其它机构共同合辩小区教育；（9）香港及澳门的中学辅导员主要是学校自聘／校内编制，两地的中学社工主要是由政府资助民间志愿机构派驻。香港的小学导员以学校自聘／校内编制和政府派驻为主，香港的小学社工以政府直接派驻为多；澳门的小学辅导员为政府派驻，小学社工则由政府资助民间志愿机构派驻为多。（10）对于两地学校辅导人员学历的比较，香港中学及小学专职辅导贝、专职社工的学历均较澳门为高．结论 两地在学校辅导目标上比较一致；两地均建立了发展辅导为主，预防辅导及治疗辅导并重的辅导模式；家庭问题及人际关系问题为两地中小学生的困扰问题；两地的学校辅导活动呈现一个多元化的局面，但香港较澳门丰富；澳门需要建立完善的转介机构。     

The linear plasmid pSA3239 is essential for the replication of the Streptomyces lavendulae subsp. lavendulae CCM 3239 chromosome

We previously reported the complete genome of Streptomyces lavendulae subsp. lavendulae CCM 3239, containing the linear chromosome and the large linear plasmid pSA3239. Although the chromosome exhibited replication features characteristic for the archetypal end-patching replication, it lacked the tap/tpg gene pair for two proteins essential for this process. However, this archetypal tpgSa-tapSa operon is present in pSA3239. Complete genomic sequence of the S. lavendulae Del-LP strain lacking this plasmid revealed the circularization of its chromosome with a large deletion of both arms. These results suggest an essential role of pSA3239-encoded TapSa/TpgSa in the end-patching replication of the chromosome.     

人偏肺病毒黏附蛋白的二级结构及B细胞表位初步预测

目的预测人偏肺病毒G蛋白的二级结构及B细胞表位。方法分别采用SOPMA方法及HMMTOP程序预测G蛋白的二级结构和跨膜区域；综合分析蛋白的柔性结构、亲水性、表面可及性与抗原性指数，预测G蛋白的抗原表位。结果G蛋白的二级结构主要为柔性区域，占62．1％；廿螺旋占22．37％；β-折叠占15．53％；N端第32～51位氨基酸残基为跨膜区。B细胞表位位于G蛋白N端55—77、80-104、111～126、130～167、178—210区段。结论应用多参数预测G蛋白的二级结构与B细胞表位，为进一步研究蛋白特征、单克隆抗体制备及表位疫苗研制奠定了基础。     

Metabolic profile of the hippocampus of Zucker Diabetic Fatty rats assessed by in vivo 1H magnetic resonance spectroscopy

Localized in vivo 1H magnetic resonance spectroscopy (MRS) was used to investigate metabolite levels in the brain of adult Zucker Diabetic Fatty (ZDF) rats, an animal model for type 2 diabetes mellitus. This study focussed on the hippocampus, assumed to be one of the main brain areas affected by this disease. Together with an almost 5-fold increase in blood glucose concentration measured by glucose oxidation, significant increases were found in the hippocampal concentrations of glucose (4.93 vs 1.66 mM p < 0.001), myo-inositol (6.52 vs 4.30 mM; p < 0.05), and total creatine (12.71 vs 10.50 mM; p < 0.05) in ZDF rats (n = 5) compared with littermates (n = 5). Although no obvious alterations were detected in the hippocampal levels of other metabolites, including NAA + NAAG and choline-containing compounds in the ZDF rats, the increase in Glc and Ins levels is in line with elevated brain tissue contents of these metabolites in patients with diabetes mellitus.     

Osteocyte ultrastructure in renal osteodystrophy

Summary The ultrastructure of the osteocyte has been studied in 80 needle biopsies from the iliac crest of uremic subjects with renal osteodystrophy.Different types of osteocytes were present in the osseous trabeculae. Those recognizable in completely uncalcified osteoid tissue looked like normal osteocytes, even though the matrix was not mineralized. Those present in hypomineralized areas showed enlarged and irregular lacunae when examined under the light microscope; under the electron microscope these osteolytic-like changes were not evident and were found to have been produced by defective calcification of the perilacunar matrix. Osteocytes placed in matrix whose mineralization was normal were often surrounded by a border of crystals protruding side-to-side from the bone matrix into the lacunar space. Other osteocytes were placed in unusually wide lacunae. They showed evidence of osteolytic activity, chiefly consisting of irregularity of the lacunar wall, presence of flocculent, granular and filamentous material in the pericellular space, and calcification of mitochondria. Degenerating and degenerate osteocytes were also recognizable.