Fungal products. Part XVII. Microbiological hydroxylation of gibberellin A9 and its methyl ester

Angiotensin II (A II) and analogues were tested for their ability to restore electrical and mechanical activity to cardiac muscle preparations in which the fast Na+ channels had been inactivated by partial depolarization (22-27 mM K+) or by tetrodotoxin (TTX). The partially depolarized or TTX-blocked preparations were chosen because under these conditions electrical and mechanical responses are primarily Ca2+ -dependent. In depolarized rabbit right atria, A II restored spontaneous mechanical and electrical activity (measured by both intracellular and extracellular recording techniques). The frequency of action potential discharge was concentration-dependent; the threshold concentration of A II was 10(-10) M, the ED50 was 8 X 10(-9) M, and the maximum effect was observed at 5 X 10(-8) M. In contrast, depolarized guinea pig atria were insensitive to A II, Sar1-angiotensin II, and des-Asp1-angiotensin II, even at concentrations as high as 10(-5) M. Rabbit papillary muscle (TTX-blocked), embryonic (18-day) chick heart (partially depolarized) and chick heart reaggregates (TTX-blocked) responded similarly to rabbit atria in that A II (9.6 X 10(-7) M) restored both electrical and mechanical activity. We found that in these preparations the action of A II was unaffected by propranolol (5.0 X 10(-6) M to 5.0 X 10(-5) M) but was blocked by Mn2+ (10(-3) M), D-600 (1 X 10(-7) g/ml) and the specific A II antagonists Sar1-Ala8-angiotensin II (P-113) (5.0 X 10(-5) M) and Sar1-Ile8-angiotensin II (5.28 X 10(-5) M). We conclude that the positive inotropic effect of A II on the myocardium is due to its ability to increase transmembrane ion movements in or through the cell membrane. The ability of Mn2+ and D-600 to block this effect suggests that this ion movement is via the so-called "slow channels."     

The emerging diversity of the electrophoretic types of Vibrio cholerae in the Western Hemisphere

Since the Latin American cholera epidemic began in 1991, 447 isolates of Vibrio cholerae O1 from the Western Hemisphere have been assayed by multilocus enzyme electrophoresis (MEE) to determine allelic variation among 16 enzyme-encoding genes. Two electrophoretic types (ETs) were identified among toxigenic isolates from Latin America: 323 were ET 4, the ET associated with the Latin American epidemic, and 29 were ET 3. Twenty-three of these ET 3 isolates had a distinctive antimicrobial resistance pattern also seen in isolates imported into the United States from Latin America and Southeast Asia. These resistant isolates had an identical ribotype and nearly identical pulsed-field gel electrophoresis (PFGE) patterns. Most nontoxigenic isolates analyzed were not precursors or descendants of toxigenic epidemic strains. MEE provided a population genetic frame-work for the interpretation of PFGE and ribotype data from the isolates in this study. All three methods identified 2 distinct strains of toxigenic V. cholerae O1 currently epidemic in Latin America.     

Distal 6p deletion syndrome: a report of a case with anterior chamber eye anomaly and review of published reports

We describe a 32 year old male with a distal 6p24.3-->pter deletion. He has specific developmental anomalies of the anterior chamber of the eye and a cleft uvula which is consistent with the recent localisation of genes for iris development and orofacial clefting to distal 6p. In addition he has progressive sensorineural deafness and this may localise a gene for deafness to this region. We conclude that a refined distal 6p deletion syndrome exists and includes a characteristic facial appearance with hypertelorism, downward slanting palpebral fissures, tented mouth, smooth philtrum, palatal malformation, ear anomalies, anterior chamber eye defects, progressive sensorineural deafness, cardiac defects, abdominal herniae, small external genitalia, and motor and speech delay.     

用于测量GIS中瞬态外壳电压的电阻性阻抗分压器

设计了用于测量GIS中TEV的阻抗分压器及其测量系统 ;分析了该系统的特性 ,并对其刻度因数和阶跃响应进行了实测 ,在实验室和现场进行了应用。结果表明 ,该系统主要性能满足IEC6 132 1标准的要求 ,可以在工程中应用     

Revisional lumbar microdiscectomy: an analysis of operative findings and clinical outcome

Forty-one consecutive patients who underwent a revision microlumbar exploration for recurrent or persistent sciatica were reviewed retrospectively to analyse the operative findings and assess the clinical outcome following surgery. Thirty-three (80%) patients were found to have a recurrent intervertebral disc protrusion at the previous site, two patients had a disc herniation at a new site, one had severe perineural scarring, two had lateral recess stenosis, one patient had undergone previous exploration at an incorrect site and in two patients no cause for ongoing symptoms was found. Nineteen of the 33 patients with a re-prolapse presented with persistent or recurrent sciatica within 1 year of their first operation. The other 14 patients presented with a late re-prolapse (after 1 year) and their clinical outcome was better than for those patients with an early re-prolapse (12/14 vs 11/19 satisfactory result, respectively). The result of operating on patients with a late re-prolapse was comparable to the 80-95% satisfactory outcomes following primary lumbar microdiscectomy reported by other authors.     

Further evidence for an imprinted gene for neonatal diabetes localised to chromosome 6q22-q23

Transient neonatal diabetes mellitus (TNDM) is a rare form of childhood diabetes which usually resolves in the first 6 months of life but which predisposes to type 2 diabetes of adult onset. We recently reported paternal uniparental isodisomy of chromosome 6 (UPD6) in two children with TNDM and proposed that there may be an imprinted gene important in the aetiology of diabetes on chromosome 6. We now describe two unrelated families which independently suggest that the gene is imprinted, is paternally expressed and maps to 6q22-q23. One family has a duplication while the other, with familial TNDM, shows linkage to a marker in this region.