Melatonin Levels in the Gastrointestinal Tissues of Fish, Amphibians, and a Reptile

Melatonin was detected by radioimmunoassay in the gastrointestinal tract (GIT) of several species of fish (sturgeon, rainbow trout, carp), amphibians (axolotl, leopard frog, bullfrog), and one reptile (red-sided garter snake), which were sacrificed during the daytime. The highest levels of melatonin were detected in the snake [means = 1018 pg/g stomach, 328 pg/g proximal gut (PG), 511 distal gut (DG)] and carp (means = 102 pg/g stomach, 146 pg/g PG and 141 pg/g DG). Lowest levels were found in the axolotl (means = 44 pg/g stomach and PG, 92 pg/g DG) and the bullfrog (means = 73 pg/g esophagus, 78 pg/g stomach, 20 pg/g PG, and 152 pg/g DG). In most cases there were no statistically significant differences in the melatonin levels among various GIT tissues of the same species but there were differences in tissue levels between different species.     

Hong Kong nurses' health-related behaviours: implications for nurses' role in health promotion

The health-related behaviours of a random sample (n=92) of Hong Kong nurses were assessed by a questionnaire written either in English or in English and Chinese. Hong Kong nurse reported negligible smoking or a alcohol use, low levels of breast self-examination, cervical screening behaviour and regular exercising, seat belt use and driving within the speed limit. The sample reported high levels of making efforts to avoid foods high in cholesterol, eating foods high in fibre and eating fruit daily. Dental hygiene was reported to be high. Just over half the sample reported sleeping 7–8 hours each night and eating breakfast daily. Most nurse reported maintaining their body weight at a healthy level and eating snacks between meals. The English language version of the questionnaire produced a slightly better response rate than the bilingual questionnaires. The results are discussed with reference to previous studies of females' health-related behaviours in Hong Kong and elsewhere. The implications for Hong Kong nurses' role in health promotion is discussed.     

Production and characterization of monoclonal antibodies cross‐reactive with major aflatoxins

Monoclonal antibodies cross‐reactive with four major aflatoxins (AFs) were produced by fusion of P3/NS‐1/1‐AG4–1 murine myeloma cells with spleen cells isolated from a BALB/c mouse that had been immunized with aflatoxin B3‐hemisuccinate conjugated to bovine serum albumin. Six stable clones were obtained. Isotyping by enzyme‐linked immunosorbent assay (ELISA) revealed that the antibodies produced by all but two of the clones were of the IgG₁ type. Of the remaining clones, one produced IgG₂₁, and the other IgA. Competitive radioimmunoassay using tritiated AFB₁ as the marker ligand revealed that two clones produced antibody that cross‐reacted well with both AFB₁ and AFG₁; one clone produced an antibody that had good specificity toward AFB₁. The relative cross‐reactivities (RCR) of antibody produced by clone 575B8F12 for AFB₁, AFB₂, AFG₁, and AFG₂ were 100, 5, 153, and 6, respectively. The RCR of antibody produced by clone 575G4H7 for the above AFs were 100, 40, 153, and 40, respectively. The RCR of antibody produced by clone 585D4D6 for the above AFs were 100, 40, 152, and 23, respectively. Antibodies produced by the other three clones were inadequate for immunoassay because their affinities for the AFs were 100 times less than the three clones described above.     

Production and characterization of antibody against fusarochromanone

Antibody against fusarochromanone (TDP‐1) was obtained from rabbits after immunization with TDP‐1 conjugated to bovine serum albumin (BSA). An indirect enzyme‐linked immunosorbent assay (ELISA) using TDP‐1‐ovalbumin conjugate as the antigen coated on to the microtiter plate was used for monitoring the antibody liter. For toxin detection, a direct competitive ELISA in which TDP‐1 was conjugated to horseradish peroxidase (HRP) was used. Competitive direct ELISA revealed that the antibody had about 5.6 and 4.5 times greater binding efficiency for monoacetyl fusarochromanone (TDP‐2) and diacetylated TDP‐1 than TDP‐1. The concentration causing 50% inhibition of binding of TDP‐1‐HRP to the antibody by TDP‐1, TDP‐2 and diacetyl‐TDP‐1 were 2.8, 0.5 and 0.62 ng/ml, respectively. For the analysis of fusarochromanones in wheat and barley, the toxins were first extracted from the commodities with 100% methanol. A small aliquot of the extract was dried, acetylated, diluted in buffer and then analyzed directly by ELISA. The overall recovery for fusarochromanone in the wheat and barley samples spiked with TDP‐1 in the concentration range of 20 to 500 ppb were found to be 97% and 103.4% with cv of 15% and 11.2% for barley and wheat, respectively.     

The dysregulated glomerular cell growth in Denys–Drash syndrome

While diffuse mesangial sclerosis is traditionally described as being the glomerulopathy of Denys–Drash syndrome (DDS), the podocyte proliferative lesions may be overlooked in these DDS cases. In the present study, an evolving process is extrapolated from a selected case of DDS that demonstrated glomerulopathy with conspicuous podocyte proliferation. The observation that podocytes express proliferation markers (Ki67, proliferating-cell nuclear antigen and topoisomerase II) in non-proliferative, mature-looking glomeruli suggests an initial pathogenic act to activate or to keep podocytes from quiescence. The subsequent proliferation of podocytes is in keeping with downregulation of WT1 and cyclin kinase inhibitors of p16 and p21. The emergence of cytokeratin-positive cells in glomeruli that show typical mesangial sclerosis implies elimination of podocytes and replacement with tubular and/or parietal epithelial cells. The final scene of evolving glomerulopathy displays apoptosis and expression of Fas-L and Bax in sclerotic mesangial lesions, which eventually end up with global sclerosis. This novel concept of DDS glomerulopathy implies complex molecular mechanisms involved in glomerular injury.     

地塞米松玻璃体植入剂应用进展

地塞米松玻璃体植入剂(DEX)是一种装载0.7mg地塞米松的可生物降解的缓释植入物,其适应证主要有视网膜静脉阻塞继发黄斑水肿(RVO-ME)、糖尿病黄斑水肿(DME)和非感染性葡萄膜炎(NIU)。DEX的应用中不良事件主要有眼压升高和白内障,也正因此DEX在RVO-ME、DME的治疗中属于二线用药,多在抗血管内皮生长因子(VEGF)治疗无应答时使用,但DEX在人工晶状体眼或不愿频繁注药的患者中能发挥出其特定的优势。近来很多研究证实了DEX治疗NIU的有效性和安全性,但其在NIU治疗中的地位尚不明确。本文综述了DEX相关的重大临床试验结果,分析其应用进展和安全性。     

康柏西普不同给药方案治疗视网膜分支静脉阻塞继发黄斑水肿

目的：对比康柏西普1+PRN和3+PRN方案玻璃体腔注射治疗BRVO继发ME的短期临床疗效。

方法：前瞻性随机对照研究,选取BRVO继发ME患者共40例40眼,随机分入1+PRN组18眼和3+PRN组22眼,对比两组患者BCVA和CMT变化及平均注药次数,分析视力预后的影响因素。

结果：治疗后6mo,3+PRN组BCVA(LogMAR)由0.86±0.22提高到0.41±0.12,CMT由517.4±75.1μm降低到280.1±41.8μm, 1+PRN组BCVA由0.79±0.20提高到0.42±0.14,CMT由472.7±80.7μm降低到271.6±39.6μm,治疗前后各时间点组间BCVA和CMT比较无差异(P>0.05)。3+PRN、1+PRN组平均注药次数分别为3.64±0.66、2.78±0.94次(P>0.05))。多元回归分析中,年龄、病程、基线BCVA、椭圆体带完整性表现出和良好的视力预后有关。

结论：康柏西普1+PRN和3+PRN方案治疗BRVO继发ME在短期内可以取得类似的疗效。