Influence of food on the pharmacokinetics of quinapril and its active diacid metabolite, CI-928

A randomized two-way crossover study was conducted in 12 healthy volunteers to assess the effect of food on the pharmacokinetics of quinapril (CI-906) and its active metabolite, CI-928, after quinapril dosing. Forty-milligram oral quinapril doses were administered in a fasted or a fed state with a one-week washout period between treatments. No significant treatment differences were observed in quinapril and CI-928 values for maximum plasma concentration, area under the plasma concentration-time curve, or percentage of dose excreted in the urine. Small but significant increases of less than 0.5 hour in quinapril and CI-928 tmax values were observed after consumption of food. The pharmacokinetic profiles of quinapril and CI-928 were not significantly altered by the administration of food.     

糖化血清蛋白测定对糖尿病监控临床意义的探讨

目的：对临床确诊糖尿病患同时测定血清葡萄糖(Glu)及糖化血清蛋白(GSP)的含量，观察二的关系，以及糖化血清蛋白水平对于评价近期(2—3周)糖尿病患血糖在体内变化的临床意义进行了观察。方法：血清葡萄糖、糖化血清蛋白测定均采用酶法测定。结果：178例糖尿病患Glu、GSP均正常3l例占17．4％；Glu、GSP均增高107例占60．1％；Glu正常、GSP增高15例占8．43％；Glu增高、GSP正常25例占14％。结论：糖化血清蛋白的含量不受即时血糖的影响，二的变化不成比例性，对评价糖尿病患2～3周病情的控制是一项灵敏可靠的指标，尤其对于住院病人的治疗与监控有一定的意义。     

Identification of non-amplifying CYP21 genes when using PCR-based diagnosis of 21-hydroxylase deficiency in congenital adrenal hyperplasia (CAH) affected pedigrees

Steroid 21-hydroxylase deficiency is among the most common inborn errors of metabolism in man. Characterization of mutations in the 21- hydroxylase gene (CYP21) has permitted genetic diagnosis, facilitated by the polymerase chain reaction (PCR). The most common mutation is conversion of an A or C at nt656 to a G in the second intron causing aberrant splicing of mRNA. Homozygosity for nt656G is associated with profoundly deficient adrenal cortisol and aldosterone synthesis, secondary hypersecretion of adrenal androgens, and a severe form of congenital adrenal hyperplasia (CAH) characterized by ambiguous genitalia and/or sodium wasting in newborns. During the course of genetic analysis of CYP21 mutations in CAH families, we and others have noticed a number of relatives genotyped as nt656G homozygotes, yet showing no clinical signs of disease. A number of lines of evidence have led us to propose that the putative asymptomatic nt656G/G individuals are incorrectly typed due to dropout of one haplotype during PCR amplification of CYP21. For prenatal diagnosis, we recommend that microsatellite typing be used as a supplement to CYP21 genotyping in order to resolve ambiguities at nt656.      

The GAP-related domain of tuberin, the product of the TSC2 gene, is a target for missense mutations in tuberous sclerosis

Tuberous sclerosis is an autosomal dominant trait in which the dysregulation of cellular proliferation and differentiation results in the development of hamartomatous growths in many organs. The TSC2 gene is one of two genes determining tuberous sclerosis. Inactivating germline mutations of TSC2 in patients with tuberous sclerosis and somatic loss of heterozygosity at the TSC2 locus in the associated hamartomas indicate that TSC2 functions as a tumour suppressor gene and that loss of function is critical to expression of the tuberous sclerosis phenotype. The TSC2 product, tuberin, has a region of homology with the GTPase activating protein rap1GAP and stimulates the GTPase activity of rap1a and rab5a in vitro. Here we show that the region of homology between tuberin and human rap1GAP and the murine GAP mSpa1 is more extensive than previously reported and spans approximately 160 amino acid residues encoded within exons 34-38 of the TSC2 gene. Single strand conformation polymorphism analysis of these exons in 173 unrelated patients with tuberous sclerosis and direct sequencing of variant conformers together with study of additional family members enabled characterisation of disease associated mutations in 14 cases. Missense mutations, which occurred in exons 36, 37 and 38 were identified in eight cases, four of whom shared the same recurrent change P1675L. Each of the five different missense mutations identified was shown to occur de novo in at least one sporadic case of tuberous sclerosis. The high proportion of missense mutations detected in the region of the TSC2 gene encoding the GAP-related domain supports its key role in the regulation of cellular growth.      

Glycoproteins present in human follicular fluid that inhibit the zona- binding capacity of spermatozoa

Previous studies have suggested that human follicular fluid contains factors that reduce the zona-binding capacity of spermatozoa. The present study provides further evidence of the existence of such factors. Using the hemizona binding assay (HZA), we have shown that the inhibitory effect of human follicular fluid on the zona-binding capacity of spermatozoa is concentration-dependent, an inhibitory effect being detected when the concentration of human follicular fluid was > or = 10%. A 1% concentration of human follicular fluid did not possess this inhibitory activity. Heating human follicular fluid at 56 degrees C for 30 min did not affect its inhibitory properties; treatment with proteinase-K abolished such inhibition. Human follicular fluid was fractionated sequentially by concanavalin-A affinity chromatography, Mono Q ion-exchange chromatography and Superose-12 gel filtration. The zona binding inhibitory activity resided in the fraction which bound to the lectin and Mono Q column and contained molecules with native molecular weights of 32 and 192 kDa. Sodium dodecyl sulphate-polyacrylamide gel electrophoresis analysis suggested that the 192 kDa glycoprotein was a tetramer, while the 32 kDa glycoprotein remained as a single molecular species under denaturing conditions. We conclude that two glycoproteins were responsible for the zona binding inhibitory activity of human follicular fluid. The physiological role of these factors remains unclear.      

Helicase Hmi1 stimulates the synthesis of concatemeric mitochondrial DNA molecules in yeast Saccharomyces cerevisiae

Hmi1p is a helicase in the yeast Saccharomyces cerevisiae required for maintenance of the wild-type mitochondrial genome. Disruption of the HMI1 ORF generates ^– and ⁰ cells. Here we demonstrate that, in ^– yeast strains, Hmi1p stimulates the synthesis of long concatemeric mitochondrial DNA molecules associated with a reduction in the number of nucleoids used for mitochondrial DNA packaging. Surprisingly, the ATPase negative mutants of Hmi1p can also stimulate the synthesis of long concatemeric ^– mitochondrial DNA molecules and support the maintenance of the wild-type mitochondrial genome, albeit with reduced efficiency. We show that, in the mutant hmi1–5 background, the wild-type mitochondrial DNA is fragmented; and we propose that, in hmi1 yeast cells, the loss of the wild-type mitochondrial genome is caused by this fragmentation of the mitochondrial DNA.     

NEW SUSPENSION DEVICE FOR LARYNGEAL ENDOSCOPIC PROCEDURES

In view of the economic constraints in acquiring sophisticated equipments in service hospitals, a new suspension device for endolaryngeal surgery using anaesthetic laryngoscope and routinely available tonsillectomy instruments has been developed. This device is a modification of Ijadoula''s suspension laryngoscope.KEY WORDS: Suspension laryngoscope, Laryngeal endoscopy