Evaluation of a direct fluorometric method for determination of serum retinol

We evaluated the usefulness of a fluorometric method for determining serum retinol (Futterman et al., Invest Ophthalmol Vis Sci 1975;14:125-30) in which fluorescence (excitation 335 nm; emission 460 nm) of retinol is directly measured in unextracted, diluted serum. Using serum from 466 individual donors, we compared values so obtained with those by a "high-performance" liquid-chromatographic method. The correlation coefficient (r) was 0.74. When we compared fluorometric retinol values with retinol-binding protein values for the 466 samples, r was 0.71. About 1% of the 466 samples had markedly higher values by fluorometry than by chromatography, the result of positive interferences. For two serum pools, we obtained CVs of 1.58% (n = 57) and 1.79% (n = 57) in long-term precision studies lasting 60 days. Although the fluorometric method of Futterman et al. has not been widely adopted, we find that it is simple to perform and that results compare favorably with the chromatographic method in precision and accuracy. It is unique among commonly used serum retinol methods in that the serum need not be extracted with organic solvents.     

The effect of neuromuscular training on the incidence of knee injury in female athletes. A prospective study

To prospectively evaluate the effect of neuromuscular training on the incidence of knee injury in female athletes, we monitored two groups of female athletes, one trained before sports participation and the other not trained, and a group of untrained male athletes throughout the high school soccer, volleyball, and basketball seasons. Weekly reports included the number of practice and competition exposures and mechanism of injury. There were 14 serious knee injuries in the 1263 athletes tracked through the study. Ten of 463 untrained female athletes sustained serious knee injuries (8 noncontact), 2 of 366 trained female athletes sustained serious knee injuries (0 noncontact), and 2 of 434 male athletes sustained serious knee injuries (1 noncontact). The knee injury incidence per 1000 athlete-exposures was 0.43 in untrained female athletes, 0.12 in trained female athletes, and 0.09 in male athletes (P = 0.02, chi-square analysis). Untrained female athletes had a 3.6 times higher incidence of knee injury than trained female athletes (P = 0.05) and 4.8 times higher than male athletes (P = 0.03). The incidence of knee injury in trained female athletes was not significantly different from that in untrained male athletes (P = 0.86). The difference in the incidence of noncontact injuries between the female groups was also significant (P = 0.01). This prospective study demonstrated a decreased incidence of knee injury in female athletes after a specific plyometric training program.     

Localization of the nonpalpable colonic lesion with intraoperative ultrasound

Localization of an nonpalpable colonic lesion at the time of colectomy usually requires intraoperative colonoscopy. The use of ultrasound to locate the lesion has not been described. A soft bowel clamp is placed above the expected location of the lesion and a catheter placed in the anus. Saline is then instilled into the colon and rectum. The lesion is located by ultrasound scan of the fluid filled colon with the probe placed on the serosal surface. Refinement of the technique was performed on resected colonic specimens. An in vivo trial was then performed with rapid and accurate localization of the lesion for resection. Intraoperative ultrasound of the colon can accurately localize nonpalpable colonic lesions and is an alternative to currently available techniques of localization. Received: 10 December 1997/Accepted: 11 March 1998     

Laparoscopic-assisted colonoscopic polypectomy

Background: The majority of colonic polyps found at endoscopy are suitable for diathermy snare excision via colonoscope. Due to location or size, some are deemed unsafe to treat in this manner and therefore require colectomy. This study describes the technique and early results of a laparoscopic-assisted colonoscopic polypectomy technique that can be used to manage such polyps and thereby avoid laparotomy and colectomy. Methods: Colonoscopy with simultaneous laparoscopy was utilized to locate the site of the polyp. The colon was mobilized, if required, and the polyp resected by electrosurgical snare via the colonoscope while the serosal aspect of the colon was monitored laparoscopically. Results: The technique has been tried successfully in six patients. Three polyps were in the cecum and three were within the left colon. The size of the polyps ranged from 3 to 7 cm. All polyps were benign on histological examination. The patients were discharged on the day following the procedure. There were no complications. Conclusions: The combination of laparoscopy with colonoscopic resection of a select group of large polyps represents a safe alternative to colonic resection. Received: 18 March 1998/Accepted: 7 May 1998     

去甲硫氨酸全肠外营养对大鼠血清氨基酸谱的影响

目的观察去甲硫氨酸全肠外营养对大鼠血清氨基酸谱等的影响.方法 Wistar大鼠24只,随机分为含甲硫氨酸(+MetTPN,n=12)和去甲硫氨酸全肠外营养2组(-MetTPN,n=12),分别给予相应的TPN支持.治疗7d后,每组随机抽取6只大鼠处死,检测血清FAA(HPLC法)、肝肾功能和全血常规,同时作心、肺、肝、肾组织病理学检查.两组其余大鼠继续原TPN治疗,观察生存期.结果 -MetTPN组大鼠血清游离Met、Cys明显降低,Asp、Glu、Ser等显著增高;大鼠体重下降;血清总蛋白和白蛋白水平下降;血常规和肾功能未见明显异常;组织学检查见肝细胞轻度肿胀,细胞核仁增粗,心肺肾未见明显异常;平均生存18d.对照组上述检查未见异常,除一只大鼠因导管并发症于TPN第16d死亡,其余大鼠全部存活.结论 -MetTPN一周可致大鼠血清游离Met、Cys明显降低和Asp、Glu、Ser等显著增高,及轻度肝功能改变;随着-MetTPN时间延长,出现严重的代谢紊乱和器官功能障碍导致死亡.     

Effects of charge and lipophilicity on mercurial-induced reduction of 45Ca2+ uptake in isolated nerve terminals of the rat.

The goal of this study was to compare the ability of neurotoxic mercurials which differ in ionic charge and/or lipophilicity to block nerve-terminal calcium channels. To do so, we examined the acute effects of methyl mercury (MeHg+), ethyl mercury (EtHg+), inorganic mercury (Hg2+), dimethyl mercury (Me2Hg), p-chloromercuribenzoate (PCMB), and p-chloromercuriphenyl-sulfonate (PCMBS-) (10-1000 microM) on 45Ca2+ flux into rat forebrain synaptosomes at rest and during depolarization. Basal (depolarization-independent) entry of 45Ca2+ was measured during 10-sec exposure to mercurials in solutions containing 5 mM KCl. Concentrations of 50, 100, 250, 500, and 1000 microM of Hg2+, MeHg+, and EtHg+ reduced basal influx of 45Ca2+. PCMB reduced basal influx at concentrations of 10, 50, and 100 microM, but increased influx at 1000 microM. PCMBS- and (Me)2Hg had no effect on basal flux at any concentration tested. Uptake of 45Ca2+ was measured after 1 sec of K(+)-induced depolarization (41.25 mM) to determine influx through voltage-dependent Ca2+ channels ("fast" phase) or during the last 10 sec of a 20-sec period of depolarization for uptake associated with a reversed Na+/Ca2+ exchanger and a residual noninactivating Ca2+ channel component ("slow" phase). Fast and slow components of 45Ca2+ uptake into synaptosomes were blocked in a concentration-dependent manner by MeHg+, EtHg+, and Hg2+. For block of the fast component, the calculated IC50's and confidence intervals were (microM) EtHg+, 92 (82, 102); Hg2+, 155 (149, 161); and MeHg+, 196 (120, 272). IC50's and the confidence intervals for the slow component of uptake were (microM) Hg2+, 49 (43, 55); MeHg+, 72 (67, 77); and EtHg+, 147 (142, 152). In contrast, Me2Hg, PCMB, and PCMBS- (10-1000 microM) caused no appreciable reduction in either phase of 45Ca2+ uptake. Increasing [Ca2+]e was unable to overcome the block induced by MeHg+ and EtHg+ (100 microM) on either phase of 45Ca2+ uptake into synaptosomes. Likewise, increasing [Ca2+]e failed to overcome block of the slow component by Hg2+ (100 microM). Increasing [Ca2+]e was able to overcome, in part, block of the fast phase induced by Hg2+ (100 microM) although the percentage of reversal was not statistically significant. The magnitude of block of 45Ca2+ uptake increased as a function of increasing [K+]e for MeHg+ and EtHg+, suggesting the block to be voltage-dependent. Thus, mercurials of dissimilar charge and lipophilicity affect synaptosomal Ca2+ uptake differentially.(ABSTRACT TRUNCATED AT 400 WORDS)     

Controlled trial of frusemide as an antiepileptic drug in focal epilepsy

1 The antiepileptic activity of oral frusemide (120 mg daily) was compared with that of an identical placebo in a double-blind crossover trial in fourteen patients with severe focal epilepsy who were receiving long-term therapy with established antiepileptic drugs.

2 A statistically significant reduction in the frequency of focal fits was seen with the active drug.

3 Marked drowsiness occurred in three patients during frusemide therapy, causing their withdrawal from the trial.

4 A slight, but significant, rise in serum phenobarbitone concentrations was observed during frusemide therapy, but no change was seen in serum primidone or phenytoin concentrations.

5 Frusemide significantly lowered plasma sodium and potassium concentrations, and increased plasma bicarbonate.

     

A prospective study of high school wrestling injuries

We performed a prospective study to evaluate injury patterns in a large population of high school wrestlers during one season. Preseason screening was performed on 458 male wrestlers from 14 different high schools. Certified athletic trainers submitted detailed weekly team and individual injury reports. There were 219 injuries in 418 wrestlers followed throughout the season for an overall injury incidence of 52 injuries per 100 wrestlers per season and an injury rate of 6.0 injuries per 1,000 exposures. The most commonly injured areas were the shoulder (24%) and knee (17%). Injured wrestlers were an average of 5 months older and had a 32% higher experience level than noninjured wrestlers. Wrestlers with ligamentous laxity suffered fewer shoulder injuries than the other wrestlers. The majority of injuries occurred in practice (63%), although the injury rate was higher in match competitions. Sixty-eight percent of practice injuries occurred during hard wrestling, 23% during drills, and 9% during conditioning. The most common wrestling situation resulting in injury was the takedown position (68%). Our results show that the older and more experienced wrestler may be at greater risk of injury. Hard wrestling during practice and the takedown position resulted in the highest occurrence of injury.