Analysis of human vestibulo-ocular reflex during active head movements

The human vestibulo-ocular reflex (VOR) was investigated during active head movements utilizing spectral analysis techniques in order to extract phase and gain characteristics for the most natural stimulus conditions. Three different experimental conditions were examined: 1) head rotation in darkness to obtain data permitting a comparison with that mode of VOR analysis which has been mose frequently employed in the past; 2) head rotation while fixating a stationary target light in order to quantify natural compensatory eye movements; and 3) head rotation while fixating a target light which moved with the head as a fast method for the quantification of visuo-vestibular interaction. High frequency head rotation in darkness yielded gains not significantly different from unity-unlike previously reported results for passive rotation (Benson, 1970; Keller, 1978). Possible mechanisms which might explain these results are discussed.     

Frontal sinus trauma: Experimental reconstruction with proplast

Trauma has become the most common pathologic entity requiring operative intervention in the frontal sinus. Treatment has evolved from simple open drainage to ablation with reconstruction at a later date. Methyl-methacrylate, currently the most widely used alloplastic material, has inherent disadvantages such as two-stage reconstruction, difficulty in handling and molding, and susceptibility to trauma. The present investigation evaluates Proplast^(r), a biocompatible Teflon fluorocarbon polymer implant, in one and two-stage frontal reconstruction following traumatic defects to the canine frontal sinus. Following the loss of anterior or posterior frontal bone, Proplast(r) provided excellent cosmetic reconstruction over a period of one year. Resistance to infection was good, reaction with dura and brain was absent, and cerebrospinal fluid leaks sealed rapidly. In contrast to other alloplastic materials, rapid vasculariza-tion and collagen ingrowth lead to stabilization rather than sequestration. Several advantages over alloplastic and metallic implants may give Proplast^(r) a unique potential in operative cranioplasty.     

Prevalence of risk factors for cardiovascular disease in Canadians 55 to 74 years of age: results from the Canadian Heart Health Surveys, 1986-1992

BACKGROUND: By 2016, the proportion of Canadians older than 65 years of age will increase to 16%, and there will be an increase in the absolute number of cases of cardiovascular disease in older Canadians. The Canadian Heart Health Surveys database provides information about this population upon which health policy related to cardiovascular disease can be based. This paper presents for the first time population-based data on the risk factors for cardiovascular disease in older Canadians. METHODS: Canadians from all 10 provinces participated in surveys of cardiovascular risk factors; health insurance registries were used as sampling frames. In each province, probability samples of 2200 adults 18 to 74 years old not living in institutions, on reserves or in military camps were asked to participate in interviews and to undergo testing at clinics for major risk factors for cardiovascular disease. RESULTS: A total of 2739 men (response rate 70%) and 2617 women (response rate 66%) aged 55 to 74 years participated in the survey and also provided follow-up clinical measurements at the clinic. Overall, 52% of participants were hypertensive, 26% had isolated systolic hypertension, and 30% had a total blood cholesterol level of 6.2 mmol/L or greater. Rates of current smoking were lower in women than men (17% v. 22%). Overall, 87% of men and 78% of women who were current smokers smoked at least 10 cigarettes per day. Only slightly more than half of participants exercised at least once a week for at least 15 minutes, and almost half had a body mass index of 27 or greater. In only 4% was no major risk factor for cardiovascular disease detected. INTERPRETATION: Significant numbers of older Canadians have one or more major risk factors for cardiovascular disease. Many of these risk factors are amenable to modification.     

Superoxide dismutase gene expression and activity in the brain of spontaneously hypertensive rats and normotensive rats

Ｍｅｍｂｒａｎｅａｂｎｏｒｍａｌｉｔｉｅｓｉｎｈｕｍａｎｅｓｓｅｎｔｉａｌｈｙｐｅｒｔｅｎｓｉｏｎｓａｒｅｗｅｌｌｅｓｔａｂｌｉｓｈｅｄ1　Ｔｏｘｉｃｏｘｙｇｅｎｍｅｔａｂｏｌｉｔｅｓｓｕｃｈａｓｓｕｐｅｒｏｘｉｄｅａｎｉｏｎｓｈａｖｅｂｅｅｎｉｍｐｌｉｃａｔｅｄｉｎｔｉｓｓｕｅｉｎｊｕｒｙｔｏｔｈｅｂｒａｉｎａｎｄｏｔｈｅｒｏｒｇａｎｓ2　Ｔｏｐｉｃａｌａｐｐｌｉｃａｔｉｏｎｏｆｆｒｅｅｒａｄｉｃａｌｓｃａｖｅｎｇｅｒｓｔｏｔｈｅｂｒａｉｎｉｎｈｉｂｉｔｓｔｈｅｄｅｖｅｌｏｐｍｅｎｔｏｆｐｉａｌ…     

磁共振胰胆管造影在阻塞性黄疸诊断中的应用

目的　评价磁共振胰胆管造影 (MRCP)技术在阻塞性黄疸诊断中的临床应用价值。方法　采用GE超导0 .5T ,Vectra 2磁共振成像仪 ,快速自旋回波 (FSE)重T2 加权扫描及最大强度投影 (MIP)重建图像 ,对 48例阻塞性黄疸患者作MRCP检查 ,所有患者均经手术证实。结果　各种病变的MRCP图像均有其特征性表达 ,MRCP对阻塞性黄疸的定位准确率为 10 0 % ,定性准确率为 93 .8%。结论　MRCP对阻塞性黄疸的诊断是一种有效、安全、可靠的方法。     

Metabolic fate of the new anti-ulcer drug enprostil in animals. 1st communication: absorption, distribution and excretion in the mouse, rat and rabbit

Absorption, distribution and excretion of [3H]-enprostil ((+-)-11a,15a-dihydroxy-9-oxo-16-phenoxy-17,18,19,20-tetranorpr osta -4,5,13(t)-trienoic acid methyl ester, TA-84135), a new anti-ulcer prostaglandin, were studied in mice, rats and rabbits. Radioactivity associated with enprostil was rapidly absorbed from the gastrointestinal tract with Tmax values of 15 or 30 min. Absorption was also efficient inasmuch as approximately 80% of an oral dose was recovered in bile and urine in 24 h in bile duct-cannulated rats. Experiments in pylorus-ligated, bile duct-cannulated rats demonstrated that enprostil was mainly absorbed from the intestine, rather than from the stomach. In mice given oral doses of 2, 8 and 32 micrograms/kg, Cmax and AUC values of enprostil radioequivalents increased proportionately to the increase in dose, indicating linear kinetics over this dose range. Distribution of enprostil-associated radioactivity was investigated in rats by quantitating tritium in various tissues after the oral administration of [3H]-enprostil. Radioactivity in tissues was highest at 15 or 30 min after dosing. Highest levels of radioactivity were found in the stomach and intestines, the organs which came into direct contact with the dose, and the liver and kidney, the organs involved in excretion of enprostil. The rate of elimination of enprostil-associated radioactivity from all tissues and from plasma was similar. Enprostil-associated radioactivity did not accumulate in any tissue. Radioactivity was found in fetuses following oral administration of [3H]-enprostil to rats on the 12th or 19th day of gestation.(ABSTRACT TRUNCATED AT 250 WORDS)     

Investigational glucagon-like peptide-1 agonists for the treatment of obesity

Introduction: Obesity is a worldwide problem predisposing to type 2 diabetes mellitus (T2DM), hypertension, cardiovascular disease, cancer and other comorbidities. Lifestyle modification is the first line intervention but adjunctive pharmacotherapy is often required. The GLP-1 receptor agonists (GLP-1RAs) were developed primarily for T2DM and they also reduce body weight. Liraglutide was approved for the treatment of obesity and other GLP-1RAs are likely to be suitable for this indication.

Areas covered: This review describes the GLP-1RAs that have been approved for the treatment of T2DM as potential candidates for the treatment of obesity and the new agents currently under development which may have advantages in patient adherence.

Expert opinion: The GLP-1RAs offer a welcome addition to obesity pharmacotherapy. They appear to be free of serious adverse effects although uncertainty remains about possible risks of pancreatitis and neoplasms. However, they have frequent gastrointestinal side effects, particularly nausea, which limits their tolerability. Cardiovascular outcome studies in T2DM support their use and this is likely to increase in both T2DM and obesity. Other GLP-1RAs which can be given by subcutaneous injection once weekly or less frequently or by oral administration would have advantages especially if nausea is less frequent than with liraglutide.     

Thyroid cancer susceptibility polymorphisms: confirmation of loci on chromosomes 9q22 and 14q13, validation of a recessive 8q24 locus and failure to replicate a locus on 5q24

Five single nucleotide polymorphisms (SNPs) associated with thyroid cancer (TC) risk have been reported: rs2910164 (5q24); rs6983267 (8q24); rs965513 and rs1867277 (9q22); and rs944289 (14q13). Most of these associations have not been replicated in independent populations and the combined effects of the SNPs on risk have not been examined. This study genotyped the five TC SNPs in 781 patients recruited through the TCUKIN study. Genotype data from 6122 controls were obtained from the CORGI and Wellcome Trust Case-Control Consortium studies. Significant associations were detected between TC and rs965513A (p=6.35×10(-34)), rs1867277A (p=5.90×10(-24)), rs944289T (p=6.95×10(-7)), and rs6983267G (p=0.016). rs6983267 was most strongly associated under a recessive model (P(GG vs GT + TT)=0.004), in contrast to the association of this SNP with other cancer types. However, no evidence was found of an association between rs2910164 and disease under any risk model (p>0.7). The rs1867277 association remained significant (p=0.008) after accounting for genotypes at the nearby rs965513 (p=2.3×10(-13)) and these SNPs did not tag a single high risk haplotype. The four validated TC SNPs accounted for a relatively large proportion (～11%) of the sibling relative risk of TC, principally owing to the large effect size of rs965513 (OR 1.74).