New stand magnifiers do not meet rated levels of performance

A new range of stand magnifiers has been released by the COIL company in the United Kingdom. Examination of these magnifiers reveals that they fail to deliver the rated magnifications labelled prominently on the appliances, as a result of the manufacturer's conformance with the requirements of the German DIN standard and the use of back vertex power (F'_v) rather than equivalent dioptric power (F_m) of the magnifier. In this study we provide information on the optometric parameters of these new stand magnifiers that will assist the more accurate specification of improvements in vision expected from their use.     

1.25 (OH)2 cholecalciferol pulse therapy and the effects of different dialysis membranes on serum PTH levels of haemodialysis patients

Either oral, intravenous or subcutaneous 1.25 (OH)₂ cholecalciferol is used in the therapy of hyperparathyroidism, which is a serious complication in patients on haemodialysis. We studied a total of 30 patients (10 women and 20 men) and divided them into two groups depending on the different types of dialysis membranes used. In the poly sulfone group, mean age was 43.7±0.97 years and the average dialysis period lasted 29.9±1.23 months. For the 15 cases in which we used cuprophane membrane the mean age was 40.2±1.31 years and the average dialysis period lasted 16.2±0.86 months. The calcium level of the dialysate in both groups was 1.5 mmol/l. According to the study protocol, the determined oral calcitriol dose was 0.07 mg/kg and it was administered intermittently. After one month on high dose calcitriol therapy, treatment was continued with a maintenance dose of 0.03 mg/kg for a further six months. As a phosphate binding agent, daily 3 g calcium carbonate was administered. Before starting this treatment protocol, patients went on a 1 mg/day calcitriol therapy, although the mean PTH level was 424.63 pg/ml and the mean serum alkaline phosphatase level was 290.2 U/l. During the pretreatment period, levels of PTH, alkaline phosphatase, ionized calcium, and total calcium remained significantly within normal limits as a result of the new therapy protocol applied. PTH and phosphorus clearance rates were compared in the patient groups in which different dialysis membranes had been used. PTH and phosphorus clearances were 15.2±3 ml/min and 239.1±19.2 ml/min, respectively, in the polysulfone membrane group, and 1.1±0.3 ml/min and 112.8±9.88 ml/min, respectively, in the cuprophane membrane group (p<0.05).     

Roles of sortase in surface expression of the major protein adhesin P1, saliva-induced aggregation and adherence,and cariogenicity of Streptococcus mutans

Sortase is a newly discovered transpeptidase that covalently links LPXTGX-containing surface proteins to the gram-positive bacterial cell wall. In this study, the sortase gene (srtA) was isolated from Streptococcus mutans NG8 by PCR. The gene encoded a 246-amino-acid protein, including a 40-amino-acid signal peptide. The srtA gene was insertionally inactivated by a tetracycline resistance cassette. P1, a major surface protein adhesin previously shown to anchor to the peptidoglycan by the LPXTGX motif, was secreted into the culture medium by the srtA mutant. In contrast, the wild-type P1 remained cell wall associated. Complementation of the mutant with srtA restored the P1 surface expression phenotype. P1 produced by the mutant, but not that produced by the wild type and the srtA-complemented mutant, was recognized by an antibody raised against the hydrophobic domain and charged tail C terminal to the LPXTGX motif. These results suggest that the failure to anchor P1 to the cell wall is due to the lack of cleavage of P1 at the LPXTGX motif. The srtA mutant was markedly less hydrophobic than the wild type and the complemented mutant. The srtA mutant failed to aggregate in the presence of saliva or salivary agglutinin and adhered poorly to saliva- or salivary agglutinin-coated hydroxylapatite. In rats, the srtA mutant colonized the teeth poorly when sucrose was absent. When sucrose was present, the srtA mutant colonized the teeth but less effectively and induced significantly less caries (P < 0.05) than the wild-type strain. In conclusion, the sortase enzyme in S. mutans is responsible for anchoring P1 to the cell surface and plays a role in modulating the surface properties and cariogenicity of S. mutans.     

经典名方当归补血汤的古代文献分析与考证

当归补血汤出自金元时期李东垣《内外伤辨惑论卷中·暑伤胃气论》,是一首被历代医家传承发扬的补气生血经典名方,已被收录于2018年国家中医药管理局公布《古代经典名方目录（第一批）》。通过系统梳理古籍文献及现代文献,并结合古代经典名方关键信息考证原则,对经典名方当归补血汤的历史源流、组成、剂量、炮制、制法与煎服法、功效与应用进行考证分析。共收集相关古籍文献信息604条,其中涉及中医古籍186部,其中40部（金元5部,明19部,清16部）中医古籍详细记载了组成、炮制、剂量等内容。有关当归补血汤组成,主要为当归和黄芪;根据古今剂量折算,黄芪37.3~38.1 g,当归7.5~7.6 g;黄芪宜采用蜜炙,当归为酒当归;加入水600 mL,煎至300 mL,饭前温服。该方古籍主要记载功效为血虚发热,证见肌热、燥热,烦渴引饮,目赤面红,昼夜不息,脉洪大而虚,重按无力,是补气生血名方。现代研究表明,当归补血汤常用于治疗各种贫血、糖尿病肾病、肿瘤、心脑血管疾病。上述研究结果为经典名方当归补血汤后期开发研究提供了参考依据。     

恶性肿瘤患者血清与尿液中一氧化氮含量测定

0 引言一氧化氮（Nitric oxide,NO）是一种具有活跃生物化学性质的无机小分子. NO对许多肿瘤细胞和微生物有细胞毒性［1］,为探讨NO与肿瘤的关系,我们检测了119例恶性肿瘤患者血清及尿液中的NO.     

Fatal meningoencephalitis due to Bacillus anthracis

Abstract: We report the first case of fatal anthrax meningoencephalitis in Hong Kong over the past 60 years. A 13 year-old boy presented with right lower quadrant pain, diarrhoea and progressive headache. Lumbar puncture yielded gram positive bacilli initially thought to be Bacillus cereus, a contaminant. He was treated with ampicillin and cefotaxime, but died 3 days after hospitalization. The organism isolated from blood and cerebrospinal fluid was later identified as Bacillus anthracis.     

Anterior and Posterior Pulmonary Cusp Augmentation in the Repair of Tetralogy of Fallot

BackgroundIn this retrospective study, we compared the results from 2 pulmonary valve augmentation techniques in patients undergoing surgical repair of tetralogy of Fallot.MethodsBetween 2015 and 2018, 18 patients had anterior pulmonary valve repair at our institution, and 26 patients had both anterior and posterior pulmonary valve repair.ResultsPatients ranged from 6 months to 30 years of age. The median follow-up period was 8 months in the anterior augmentation group and 5 months in the anterior and posterior augmentation group. Postoperative echocardiograms indicated that only 2 patients (11%) in the anterior augmentation group had moderate or severe pulmonary insufficiency, compared with no patients in the anterior and posterior augmentation group. At follow-up, pulmonary insufficiency was seen in 3 patients (17%) in the anterior augmentation group and no patients in the anterior and posterior augmentation group.ConclusionReconstruction of the native pulmonary valve accompanied by pulmonary cusp augmentation can decrease or even circumvent postoperative pulmonary insufficiency. Both anterior augmentation and anterior and posterior augmentation techniques are easily applied; however, we believe that the anterior and posterior augmentation technique is superior in terms of early postoperative and follow-up pulmonary insufficiency outcomes.     

The mutagenic,antimutagenic and antioxidant properties of Hypericum lydium

Context: There is a growing market demand for Hypericum sp., a pharmacologically active plant that has been traditionally used to treat various ailments. However, there have been limited studies on the extract or essential oil of Hypericum lydium Boiss (Hypericaceae).

Objective: This study investigates for the first time the antioxidant, mutagenic and antimutagenic activity of an ethanol extract of H. lydium.

Material and methods: Ethanol extract from aerial parts of H. lydium harvested from Turkey were tested for this mutagenic and antimutagenic activities (2.0–0.002?mg/plate) using Ames Salmonella/microsome test system. 4-Nitro-o-phenylenediamine (4-NPD) (3?μg/plate) for the Salmonella typhimurium TA98 and sodium azide (NaN₃) (8?μg/plate) for the S. typhimurium TA100 were used as positive controls. The antioxidant activity, total antioxidant activity and phenolic constituent of the extract (2.0–0.002?mg/mL) was determined by the inhibition of 2,2-diphenyl-1-picrylhydrazyl radical (DPPH), β-carotene-linoleic acid model and by means of Folin–Ciocalteu reagent, respectively.

Results: The extract showed no sign of mutagenicity at the tested concentrations (0.002–2.0?mg/mL), and showed concentration-dependent antimutagenic activity against NaN₃ and 4-NPD ranging from 26.8 to 81.5%. The extract was found to be an efficient scavenger of DPPH (IC₅₀ 0.165?±?0.23?mg/mL) and to inhibit β-carotene-linoleic acid bleaching (IC₅₀ 0.39?±?0.11?mg/mL).

Discussion and conclusion: These findings indicate ethanol extract of H. lydium to be a safe and effective agent that may be incorporated into new strategies for the prevention of cancer and mutagenesis.