Suppressive effects of minocycline on the pituitary-thyroid axis in humans

Minocycline has been thought to induce “black thyroid”, a condition marked by discoloration due to brown deposits. However, its effect on thyroid function in humans is still obscure. We conducted a prospective study of thyroid hormone levels in 17 patients who were administered 200 mg minocycline daily for 10 days. We found that minocycline significantly reduced the serum total thyroxine level (8.43±0.61 to 7.09±0.45 μg/dl, mean ± SEM;P<0.01), and free thyroxine level (1.12±0.10 to 1.01±0.08 ng/dl, mean ± SEM;P<0.01). There was also a slight, but insignificant, elevation of thyroid stimulating hormone (TSH) in patients treated with minocycline. Similar suppression of thyroxine and free thyroxine was not observed in control patients treated with β-lactam and/or aminoglycoside antibiotics. Risk factors for the reduction in these thyroxine levels included age and a high serum baseline level of free thyroxine. We found a significant correlation between the free baseline thyroxine level and a reduction in free thyroxine after minocycline administration (Y=0.420X−0.377, r=0.597;P<0.01). Despite the observed alterations, the serum levels of all thyroid hormones after minocycline therapy were still within the normal range. This antibiotic does not appear to induce clinical hypothyroidism, yet given the results of this study, we would like to recommend pituitary-thyroid axis monitoring during the use of this antibiotic.     

Response to travoprost in black and nonblack patients with open-angle glaucoma or ocular hypertension

Two prospective, controlled, multicenter, double-masked studies—one lasting 6 months (n=594) and the other, 12 months (n=787)—examined the intraocular pressure (IOP)-lowering efficacy of travoprost in 1381 black and nonblack patients with open-angle glaucoma or ocular hypertension. Investigated regimens were travoprost 0.004% once daily, latanoprost 0.005% once daily, and timolol 0.5% twice daily. In both studies, mean IOP was significantly lower in blacks treated with travoprost. The IOP reduction was also significantly greater in blacks after adjustments for age, sex, iris color, diagnosis, and corneal thickness. Timolol lowered mean IOP to a greater extent in nonblack patients. The significantly larger IOP reduction with travoprost compared with timolol in both racial groups was more pronounced in blacks. Travoprost also was superior to latanoprost in blacks. Mean changes from baseline generally were greater for black than for nonblack patients, although the differences did not achieve statistical significance. The response rate to travoprost was higher in blacks. The most common adverse effect was hyperemia.     

Nutritional and racial determinants of the increase in plasma homocysteine levels after methionine loading

Background: Low circulating plasma levels of total homocysteine (tHcy) are associated with a lower prevalence of coronary heart disease among black people than among white people living in Burkina Faso.Objective: The purpose of this study was to provide a rationale for a possible mechanism for the decrease in plasma tHcy levels among black people compared with white people living in Burkina Faso.Methods: Healthy, black, adult, lifelong inhabitants of Burkina Faso and healthy, white adults born in Italy but living in Burkina Faso ≥5 years were eligible for enrollment. Controlled diets were assigned to all subjects for 2 weeks before the study. After an overnight (12-hour) fast, a methionine-loading test was performed in all subjects. Plasma levels of tHcy, cysteine, glutathione, and cysteinylglycine were measured simultaneously using high-performance liquid chromatography after fasting (baseline) and at either 4 and 8 hours (n = 30) or 2, 4, 6, and 8 hours (n = 4) after methionine loading. During the 12 hours after loading, the clinical conditions and adverse events of subjects were monitored. Results were analyzed using the Student t test and Mann-Whitney U test.Results: Seventeen black adults (9 males, 8 females; median age, 21 years) and 17 white adults (8 males, 9 females; median age, 35 years) were enrolled. Mean plasma levels of tHcy, cysteine, and glutathione increased from mean baseline levels more slowly in the black group than in the white group and peaked 8 hours after methionine loading (16.8 ± 3.0 μmol/L, 130.4 ± 25.7 μmol/L, and 68.3 ± 21.2 μmol/L, respectively). In the white group, these levels peaked 4 hours after loading (16.1 ± 4.0 μmol/L, 215.8 ± 18.6 μmol/L, and 38.6 ± 12.4 μmol/L, respectively). Only the mean plasma cysteinylglycine level decreased significantly (from 35.7 ± 11.4 μmol/L to 19.0 ± 6.1 μmol/L; P < 0.01) in the black group after 4 hours. This decrease was followed by an increase after 8 hours (29.6 ± 12.0 μmol/L). In the white group, a less remarkable change in mean cysteinylglycine level was observed, with a peak after 4 hours (16.3 ± 4.3 μmol/L).Conclusions: The findings of this study suggest that, in addition to lower plasma tHcy levels, the metabolism of plasma tHcy is different in black people than in white people after methionine loading. This difference may be due to different alimentary habits associated with a reduced dietary availability of methionine. Moreover, the higher plasma levels of glutathione before and after methionine loading appear to occur exclusively in black people compared with whites and correspond with the variation of cysteinylglycine, suggesting that, in addition to nutritional factors, a racial component may contribute to the difference in plasma levels of tHcy. This difference also might explain, in part, the lower prevalence of coronary heart disease in black people living in Burkina Faso compared with that in other populations.     

A systematic review on SARS-CoV-2-associated fungal coinfections

A severe pandemic of Coronavirus Disease (COVID-19) has been sweeping the globe since 2019, and this time, it did not stop, with frequent mutations transforming into virulent strains, for instance, B.1.1.7, B.1.351, and B.1.427. In recent months, a fungal infection, mucormycosis has emerged with more fatal responses and significantly increased mortality rate. To measure the severity and potential alternative approaches against black fungus coinfection in COVID-19 patients, PubMed, Google Scholar, World Health Organization (WHO) newsletters, and other online resources, based on the cases reported and retrospective observational analysis were searched from the years 2015–2021. The studies reporting mucormycosis with Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) coinfection and/or demonstrating potential risk factors, such as a history of diabetes mellitus or suppressed immune system were included, and reports published in non-English language were excluded. More than 20 case reports and observational studies on black fungus coinfection in COVID-19 patients were eligible for inclusion. The results indicated that diabetes mellitus, hyperglycemic, and immunocompromised COVID-19 patients with mucormycosis were at a higher risk. We found that it was prudent to assess the potential risk factors and severity of invasive mycosis via standardized diagnostic and clinical settings. Large-scale studies need to be conducted to identify early biomarkers and optimization of diagnostic methods has to be established per population and geographical variation. This will not only help clinicians around the world to detect the coinfection in time but also will prepare them for future outbreaks of other potential pandemics.     

T2-MATRIX序列在急性下肢深静脉血栓诊断中的应用

目的探讨T2加权的3D可变翻转角三维快速自旋回波(T2 weighted 3D fast spin echo imaging with modulated refocusing flip angles,T2-MATRIX)序列在急性下肢深静脉血栓形成(lower extremity deep vein thrombosis,LEDVT)诊断中的价值,为早期、精确诊疗LEDVT提供新的影像学方法。材料与方法前瞻性连续收集急性期LEDVT患者21例,均于发病后14 d之内进行T2-MATRIX序列成像,同时行3D磁化强度预备梯度回波序列(magnetization prepared rapid acquisition gradient echo,MPRAGE)成像和超声检查。由两名放射科医生在血管节段水平分别对T2-MATRIX和MPRAGE图像进行双盲判读。比较两种序列在血栓长度、面积及血栓信号强度等指标的评价一致性。以MPRAGE和超声为联合参考标准,计算T2-MATRIX序列检出血栓的诊断准确性。结果纳入的21例LEDVT患者中,共计147个血管节段,其中67个血管节段检出血栓。在血管节段水平T2-MATRIX检出LEDVT的敏感性为94.03%,特异性为98.77%,阳性预测值为98.41%,阴性预测值为95.24%,准确性为96.60%。组内相关系数分析和Bland Altman分析显示T2-MATRIX和MPRAGE序列在血栓长度、面积及血管管径定量评估方面具有较强的一致性(P≤0.05),位于一致性界限内的差值分别占总数的98.51%、97.1%和100%。结论 T2-MATRIX序列诊断急性期LEDVT具有较高的诊断准确性,同时还能显示周围软组织水肿程度,是一个新的影像学检查方法,有望用于临床。     

白桑叶熏洗结合红外偏振光治疗髌骨滑囊炎临床研究

目的:观察白桑叶熏洗结合红外偏振光照射治疗髌骨滑囊炎的临床治疗效果。方法:53例髌骨滑囊炎患者随机分为实验组和对照组。实验组30例,予白桑叶熏洗加红外偏振光照射治疗,1次/d,4周为1个疗程;对照组23例,予白桑叶熏洗治疗,方法同实验组。治疗2个疗程观察疗效、HAQ值和VAS评分以及肌四头肌肌肉力量。结果:实验组总有效率达到90.0%,远高于对照组的60.9%(P0.01);实验组HAQ值明显低于对照组(P0.01),VAS评分明显低于对照组(P0.05),股四头肌肌肉力量明显优于对照组。结论:白桑叶熏洗结合红外偏振光照射治疗髌骨滑囊炎具有较好临床疗效。     

制首乌辅料黑豆的质量控制研究

目的:建立制首乌辅料黑豆原料及其在炮制品中的质量控制方法。方法:通过比较黑豆、豆制何首乌和清蒸何首乌HPLC色谱图差异,确定制何首乌辅料黑豆的质量控制指标,在此基础上,建立豆制何首乌中黑豆的检测方法和黑豆原料的质量控制方法。结果:通过HPLC色谱图比较,检测到豆制何首乌中的微量大豆苷元。建立了制何首乌中黑豆的TLC色谱检测方法。采用HPLC,建立了黑豆原料中大豆苷元含量测定方法,测定了12批不同产地黑豆,以广东产黑豆大豆苷元含量最高。结论:本方法可作为制首乌辅料黑豆原料及其在炮制品中的质量控制方法。     

Oral toxicological studies of black soybean (Glycine max) hull extract: Acute studies in rats and mice, and chronic studies in mice

Black soybean (Glycine max) has been used for traditional medicine and food in Asian countries, but safety of its hull has not been studied. We conducted acute and chronic oral toxicity studies. For the acute study, an extract of black soybean hull (BE; 2.5 g/kg body weight) was administered singly by intragastric intubation to Sprague–Dawley rats and C57BL/6 mice. There was no death or significant decrease in body weight in rats and mice, and the oral LD₅₀ of BE was >2.5 g/kg body weight. In the chronic study, BE was administered at dietary levels of 0% (control), 2.0%, and 5.0% to male and female C57BL/6 mice for 26 weeks. No mortality or toxicologically significant clinical changes were observed through the experimental period. Although body weights, as well as abdominal fat, blood levels of triglyceride and total cholesterol in 5.0% males were significantly lower than that in control and 2.0% groups, these changes were considered not to be adverse. Hematology and histopathological observation revealed no toxicologically significant changes. The no-observed adverse-effect-level of BE was estimated to be 5.0% in the diet (5074.1 mg/kg body weight/day for males and 7617.9 mg/kg body weight/day for females).