原子吸收光谱法测定糖尿病患者血清锌、镁、钙含量的研究

采用原子吸收光谱法测定了30例糖尿病患者血清锌、镁、钙的含量,并与30例正常人相比较。结果表明,其锌和镁较正常人为低(P<0.05),但钙与正常人无显著性差别。另外,本文还对锌、镁与糖尿病的关系进行了探讨。     

经咽旁入路选择性切除大鼠垂体前叶的研究

目的研究经咽旁入路选择性的切除大鼠垂体前叶，以制备大鼠垂体前叶激素缺乏模型如生长激素（GH）缺乏模型。方法经腹侧咽旁入路，运用显微神经外科技术经基蝶骨底选择性地切除垂体前叶。然后采用竞争免疫沉淀法检测大鼠生长激素的含量，术后统计死亡率、成功率。结果切除垂体前叶后大鼠的死亡率为26．7％，成活率为73．3％，全切率为91％；成功制备大鼠模型的GH显著低于假手术组和对照组。结论运用显微外科技术可以成功的选择性的切除大鼠垂体前叶，制备出垂体前叶激素如生长激素缺乏的动物模型。     

Challenges in the Diagnosis of the Right Patient for Testosterone Replacement Therapy

Diagnosis of testosterone deficiency is important to identify patients who might benefit from testosterone replacement therapy. Unfortunately, the diagnosis of hypogonadism may be a challenge for many practicing physicians, including endocrinologists and urologists. Signs and symptoms, such as sexual dysfunction, change in body composition, lethargy, and mood changes, are nonspecific and the available questionnaires are generally not useful in clinical practice. The diagnosis of testosterone deficiency is ultimately based on measurement of serum testosterone levels. However, marked variations in the reference ranges of serum testosterone levels among laboratories pose a challenge for physicians when interpreting the results. In addition, initial laboratory assessments usually determine total testosterone levels. About 1–2% of total testosterone is free and a further 30–50% is bound with low affinity to albumin; only these two components are bioavailable to the target tissues. In general, assuming the normal reference range for serum total testosterone in adult men is 300–1000 ng/dl (10–35 nmol/l), levels of < 250 ng/dl (8.7 nmol/l) suggest the patient is likely to be hypogonadal, whereas levels of > 350 ng/dl (12.7 nmol/l) suggest the symptoms may not be due to androgen deficiency. Values between 250 to 350 ng/dl warrant a repeat morning serum testosterone determination with assessment of free or bioavailable testosterone. In men with symptoms suggestive of androgen deficiency and borderline serum testosterone levels, where there are no contraindications to androgen therapy, a short therapeutic trial of testosterone may be justified.     

The profibrinolytic effect of plasma thrombomodulin in factor XI deficiency and its implications in hemostasis

Bleeding tendency in factor (F)XI deficiency may result from premature clot lysis due to insufficient thrombin activatable fibrinolysis inhibitor (TAFI) activation. Thrombomodulin (TM), upon binding to thrombin, is capable of modulating TAFI activation. In this study, we investigated the effects of plasma TM on fibrinolysis in FXI-deficient patients. A clot lysis assay showed the defective down-regulation of fibrinolysis in FXI-deficient patients as compared with normal controls. To evaluate the effects of plasma TM on fibrinolysis, a monoclonal anti-TM IgG was preincubated with plasma for 30 min. The presence of anti-TM IgG significantly prolonged the clot lysis times both in the FXI-deficient and normal plasma, indicating that plasma TM stimulated fibrinolysis. Furthermore, the presence of anti-TM IgG not only reduced protein C activation, but also increased thrombin generation and TAFI activation. The profibrinolytic effect of plasma TM was inhibited in the assay by including either a monoclonal anti-TAFI IgG or a specific TAFI inhibitor--carboxypeptidase inhibitor (CPI). Our results indicate that the impaired thrombin generation in FXI-deficient patients leads to the defective down-regulation of fibrinolysis, and that plasma TM stimulates fibrinolysis through APC pathway which inhibits TAFI activation. The profibrinolytic effect of plasma TM may contribute to the bleeding tendency observed in some FXI-deficient patients.     

Effect of a minor vitamin A deficiency on the course of infection with <Emphasis Type="Italic">Ascaridia galli</Emphasis> (Schrank, 1788) and the resistance of chickens

Summary The effect of vitamin A deficiency was studied in chickens infected with 500 Ascaridia galli eggs and controls. Diet 1 (deficient, 500 IU vitamin A or 172 μg retinol acetate per kg diet), Diet 2 (deficient, 1000 IU vitamin A or 344 μg retinol acetate per kg diet) and Diet 3 (sufficient, 1500 IU vitamin A or 516 μg retinol acetate per kg diet) were assigned to 46 chickens each. Clinical signs, weight gains, livers’ weights, vitamin A levels, worm burdens and parasite eggs’ excretions were recorded. Infected chickens had lower weight gains than the controls fed alike. Chickens given Diet 1 stored lesser vitamin A in liver than those fed Diet 3. Although worm counts in the 3 groups did not differ significantly, chickens fed Diet 1 excreted more A. galli eggs than those fed the 2 other diets. Female worms harboured by chickens fed Diet 1 had higher fecundity at week 5 pi than those of chickens fed Diet 2. Results indicated that Vitamin A is important for poultry in the moderation of the infection with A. galli.     

催化光度法测定灵芝中微量锌

目的　研究催化光度法测定灵芝中微量锌。　方法　在非离子表面活性剂 Tween- 80存在下 ,于 p H9.5 0 NH3- NH4 Cl缓冲溶液中 ,Hg( )催化加速 Zn( )与 meso- 4 (4 -甲基 ,3-磺基苯基 )卟啉 (TTPS4 )的显色反应。　结果　 Zn( )与 TTPS4 、Tween- 80形成很稳定的三元配合物 ,其ε=3.86× 10 5,Zn( )浓度在 0 .0 0 5～ 0 .10μg/ m L,符合比尔定律 ,检出限为 0 .0 0 1μg/ m L。　结论　 Tween- 80对 Zn( )与 TTPS4 显色有增敏 ,而 Hg( )催化加速 Zn( )与 TTPS4 显色反应 ,应用本法可直接测定灵芝中的微量锌     

Lung function, smoking and survival in severe alpha 1-antitrypsin deficiency, PiZZ

Lung function, smoking, age and mortality data in 158 adult severe alpha₁-antitrypsin deficient, PiZZ individuals, followed from 1963 to 1982 were analyzed. Low initial FEV₁ value was significantly associated with increased mortality (p < 0.005). A 3 yr mortality rate of 40% was found in individuals whose initial FEV₁ values were less than 30% of that predicted. In contrast, the corresponding 3-yr mortality among those whose initial FEV₁ values were between 30 and 65% of that predicted was only 7%. Smokers were found to have significantly lower FEV₁ levels (p = 0.008) and higher mortality (p < 0.005) than non-smokers. The difference between current and ex-smokers in mortality and FEV₁ level were not statistically significant (p = 0.9 and p>0.25, respectively). Cross-sectional analysis of the initial FEV₁ values indicated a significant decline (p < 0.005) of FEV₁ with increasing age. This decline was greater among smokers than non-smokers. Longitudinal analysis of FEV₁ rates of decline in 80 cases with follow-up FEV₁ measurements failed to detect any significant differences between smokers and non-smokers, but was performed late in the disease process. The application of these results to the planning of studies on replacement therapy, smoking intervention strategy and longitudinal follow-up is discussed.     

Urinary 17α-hydroxyprogesterone in management of 21 -hydroxylase deficiency

Objectives: The study was designed to assess the reliability of measurement of 24-hour urinary 17α-hydroxyprogesterone (17-OHP) by radio-immunoassay (RIA) as an alternative biochemical assessment for monitoring the treatment of congenital adrenal hyperplasia (CAH) due to 21 -hydroxylase deficiency (21 -OHD) and to assess the need for sample purification by column chromatography to improve assay specificity.
Methodology: Morning serum 17-OHP was measured using RIA and 24-hour urinary pregnanetriol using gas chromatography. Twenty-four-hour urinary 17-OHP was measured in samples from 17 prepubertal patients with CAH due to 21 -OHD, and 20 normal prepubertal children as controls. In 24 urine samples, RIA of 17-OHP was performed with and without column chromatography.
Results: There was a good correlation between 24-hour urinary 17-OHP and 24-hour urinary pregnanetriol (r = 0.962, P <0.01) and between 24-hour urinary 17-OHP and morning serum 17-OHP ( r = 0.955, P <0.01). There was no significant difference in the RIA of the urine samples with and without purification by column chromatography.
Conclusions: The measurement of 24-hour urinary 17-OHP is a reliable alternative for the biochemical monitoring of 21-OHD, and RIA specificity is unaffected by omission of column chromatography.     

Pyridinium crosslinks of collagen as a marker of bone resorption rates in children and adolescents: Normal values and clinical application

The aim of our study was to establish normal values of urinary pyridinoline (Pyr) and deoxypyridinoline (DPyr) excretion for children aged 3–18 years, examine the biological variability of the marker, and assess its clinical value for pediatric patients with growth hormone deficiency. Pyr and DPyr was measured in first void urine samples from 692 healthy subjects (340 boys, 352 girls) by high-performance liquid chromatography. At sampling, age, body height, and weight was recorded for all individuals. Short-term variability in crosslinks excretion was examined in four healthy children. The clinical value of the marker was studied in seven patients with growth hormone (GH) deficiency. In childhood, crosslinks excretion exceeded normal adult values by about fivefold and declined during puberty. In the age range of 13–18 years, gender-related differences in Pyr and DPyr levels were observed, presumably resulting from the earlier onset of puberty in girls. Urinary levels of Pyr and DPyr were highly correlated both in males and females. Pyr/DPyr ratio was significantly higher in adolescents than children, suggesting enhanced release of Pyr from extraosseous sources. In both genders, neither age nor anthropometric variables showed a linear effect on crosslinks excretion. The range of within-subject, short-term variability in urinary Pyr and DPyr was relatively high (CV: 6%–21%), indicating that single measurements of crosslinks excretion may not adequately reflect bone resorption rates in children. Pyr and DPyr levels were significantly lower in GH-deficient patients and normalized during human growth hormone (hGH) therapy. Significant correlations between growth velocity (GV) and crosslinks levels were found, but individual prediction of GV increment during hGH treatment may be inaccurate. Pyr/DPyr ratio was not related to GV. It is concluded that measurement of urinary Pyr and DPyr excretion in children may be a valuable tool to assess bone resorption rates in population-based studies. In individual patients, however, only qualitative evaluation of disease severity and response to treatment seems justified.