输尿管支架管结壳患者尿液菌群的分布特点

目的探讨输尿管支架管结壳患者尿液菌群的分布特点。方法选取2018年10月至2019年3月在山东省立第三医院、山东大学齐鲁医院、济南市中心医院和济南市济钢医院就诊的35例输尿管支架管置入术后患者。纳入标准:年龄18~65岁;输尿管镜碎石术后留置内支架管4周。排除标准:尿液细菌培养阳性;严重肉眼血尿;近期口服抗生素;存在明显残石患者。本研究采用横断面研究方法(临床研究注册号为ChiCTR1800020025),根据有无支架管结壳将患者分为结壳组23例和无结壳组12例。收集拔管当日患者尿液行细菌16s DNA检测。使用UPARSE、UCHIME和RDP calssifier等软件分析两组患者尿液菌群分布特点,明确两组患者尿液中细菌种类总数、细菌丰度,以及丰度占比较大的细菌类别,比较两组患者尿液细菌种类、数量及细菌丰度的差异,明确结壳组患者尿液中丰度占比较大的细菌菌属。结果两组患者的年龄、性别、体质指数、置管侧别、内支架管型号及结石成分差异均无统计学意义(P>0.05)。16s DNA检测结果显示,结壳组丰度占比>1%的菌属数量为11个,丰度占比>0.01%的菌属数量为74个;无结壳组丰度占比>1%的菌属数量为7个,丰度占比>0.01%的菌属数量为11个,两组丰度占比>1%的菌属数量比较差异有统计学意义(t=5.12,P=0.000)。结壳组中菌属丰度占比前3位分别为乳杆菌属(23.1%)、拟杆菌属(18.8%)和未分级拟杆菌属(17.1%),非结壳组中菌属丰度占比前3位分别是为埃希菌-志贺菌属(32.2%)、肠球菌属(24.9%)和假单胞菌属(18.2%)。两组间差异最大的3种细菌是乳杆菌属(P=0.010),拟杆菌属(P=0.004)和未分级拟杆菌属(P=0.004)。结论支架管结壳患者尿液中细菌种类和数量都明显多于非支架管结壳患者。拟杆菌属细菌在支架管结壳患者尿液中的细菌种类丰度较大。     

Urinary oxalate and glycolate excretion in healthy infants and children

The molar ratios of oxalate and glycolate over creatinine were determined in single urine samples of 26 infants and 27 children aged 1–5 years. In 135 children aged 5–16 years, two urine specimens were collected, one before breakfast and one at noon. Oxalate was determined by oxalate oxidase, and glycolate was measured by a colorimetric method (improved chromatotropic acid-sulphuric acid assay after prior purification by cation and anion exchanger). Both ratios (expressed in mmol/mol creatinine and analysed on a log-normal basis) were highest in infants 0–6 months old [mean oxalate 147 (95% confidence interval: 60–360), mean glycolate 175 (72–425)]. The mean oxalate ratio was 72 mmol/mol (29–174) at the age of 7–24 months, 44 (19–101) at the age of 2–5 years and 22 (12–40) in adolescents aged 16 years. Molar glycolate ratios were higher, but disclosed the same pattern. Oxalate and glycolate ratios in fasting urines did not differ significantly from those in noon samples (except glycolate in the oldest age group). Oxalate ratios correlated well with glycolate ratios in children up to 5 years of age only. Random urine samples are thus suitable for screening. However, interpretation of data requires use of age-specific reference values that are based on comparable methods.     

Effects of different doses of alkaline citrate on urine composition and crystallization of calcium oxalate

Summary Prophylactic treatment with alkaline citrate in patients with recurrent calcium oxalate (CaOx) stone disease results in reduced CaOx supersaturation and increased urinary citrate. The effects of a single evening dose were compared with those of two and three daily doses in six recurrent CaOx stone formers with hypercalciuria, hypocitraturia or raised calcium/citrate quotients. While on a standardized hospital diet the patients were given 7.5 g (28 mmol) of sodium potassium citrate (URALYT-U) in one, two, and three doses. Fractional urine collections during 24 hours were analyzed for pH, composition, and crystallization risk (CR). All dosage regimens had favourable effects on urinary calcium, citrate, calcium/citrate quotients, and CaOx-CR. The most sustained effect was recorded with three divided doses. Single evening doses resulted in the most pronounced effects between 22.00–06.00 h, thereby counteracting the increased risk of CaOx crystallization during that period. In terms of 24 h urine composition the best effect was recorded with alkaline citrate administered three times daily, but because of the favourable response by a single evening dose between 22.00–06.00 h the assumption was made that this dosage regimen might be sufficient to reduce the risk of CaOx crystallization and stone formation. However, the validity of such an assumption can only be established by long-term clinical studies.     

A method for studying inhibitory activity in whole urine

Summary A method has been developed for inducing and quantifying calcium oxalate crystallisation in whole human urine. The propensity of a given urine to induce crystal formation was described in two ways: 1) its ability to resist spontaneous nucleation of calcium oxalate crystals was assessed by titrating 20 mls of the urine with increasing quantities of sodium oxalate (0–150 mol) to determine its practical metastable limit. This limit was inversely related to the endogenous calcium concentration. 2) its capacity to inhibit crystal growth was quantified by determining the rate of growth of calcium oxalate crystals precipitated in response to a fixed oxalate load (30 mol) above its metastable limit. The crystals produced were predominantly calcium oxalate dihydrate and were morphologically identical to those occurring naturally in urine. Citrate had no effect on the metastable limits of 3 urines examined, but markedly inhibited crystal growth. Pyrophosphate had a similar effect on crystal growth, and in addition, raised the metastable limit of one of the urine samples.     

Circadian rhythm of lithogenic substances in the urine

Summary After determination of the lithogenic and inhibitory substances in serum and urine of 18 healthy control subjects and 20 patients with calcium oxalate urolithiasis on an uncontrolled diet, the alteration of the parameters while taking a standard diet was investigated. After attainment of a steady state, the investigations were performed over 48h on 3-h aliquots of urine. Typical circadian rhythms were detected for all lithogenic parameters in the urine and normal ranges were established. This special investigation permits detection of peaks in the excretion of lithogenic substances which were masked in investigation of 24-h urine samples alone.     

Innovation According to C. Walton Lillehei

C. Walton Lillehei (1918–1999) represents the most distinguished American surgeon of his time and perhaps the greatest surgeon in history. As his mentor, Owen H. Wangenesteen (1898–1981), so accurately declared, Walt Lillehei was “one of the surgical immortals.” Indeed, similar words were echoed by the famous cardiac surgeon, Denton A. Cooley (b. 1920), who said, “Hardly any other cardiac surgeon has introduced a greater number of innovative techniques and concepts.”

Born in Minneapolis, Lillehei attended the University of Minnesota, where he completed his college, medical, physiology, and surgical studies. Because of his extraordinary contributions to make open heart surgery feasible and safe, he is considered the father of open heart surgery. Many other contributions followed the initial innovations, particularly the use of the bubble oxygenator, the total intracardiac repair of tetralogy malformation, the use of myocardial electrodes for treating complete heart block, and the development of three cardiac valve prostheses, among other discoveries.

The noted Minnesota surgeon was an innovator for his entire professional career. He believed in innovation and practiced innovation in any way possible. “Determination, persistence, and stubbornness” were, according to Lillehei, “the most important components of research and successful discovery.”     

Zonisamide and renal calculi in patients with epilepsy: how big an issue?

ABSTRACT

Objectives: To determine the prevalence of renal calculi in patients treated with zonisamide during randomized, controlled and open-label clinical trials, and from post-marketing surveillance data.

Methods: Reports of renal calculi from four placebo-controlled double-blind trials of zonisamide, their long-term open-label treatment extension phases, and the US/European zonisamide clinical trial programme were reviewed. One double-blind study and its extension included routine ultrasound screening to identify asymptomatic calculi. Post-marketing surveillance data were also investigated, as was concomitant treatment with topiramate.

Results: No symptomatic renal calculi were reported during four randomized double-blind, placebo-controlled trials involving 848 subjects (including 498 zonisamide recipients) treated for up to 3 months. In long-term extension studies with treatment for up to 24 months, symptomatic renal calculi were reported in 9/626 (1.4%) patients. Pooled safety data from all US/European clinical trials identified 15/1296 (1.2%) patients with symptomatic renal calculi during treatment for up to 8.7 years. Post-marketing surveillance revealed nine cases from 59?667 patient-years of exposure in the USA, and 14 from 709?294 patient-years of exposure in Japan; only one case occurred during concomitant topiramate and zonisamide treatment. No imbalance in electrolyte levels was found from 35 patients receiving such co-treatment in clinical trials.

Conclusions: The available data suggest that the risk of developing renal calculi during zonisamide treatment is low. Data are insufficient to determine whether concomitant treatment with topiramate increases the risk of renal stones.