吸氧对听感觉门控P50的影响

目的研究呼吸纯氧对健康人听感觉门控P50的影响。方法右利手、健康男性大学生志愿者28名,根据随机数字表分为对照组(n=12)和实验组(n=16)。佩戴面罩,对照组呼吸空气,实验组呼吸医用纯氧60 min。应用条件-测试刺激,记录吸氧前(pre0)、吸氧20 min(Oxy20)、吸氧50 min(Oxy50)、吸氧后30 min(post30)的脑电图,计算听觉P50潜伏期和P50感觉门控电位(S1与S2振幅之差)。结果 S1刺激在4个时间点各组P50潜伏期相对稳定(P0.7);吸氧50 min时,实验组比对照组P50潜伏期缩短(P0.05)。S2刺激在4个时间点各组P50潜伏期相对稳定(P0.30),两组间比较无显著性差异(P0.05)。对照组P50门控电位比较稳定(P=0.70),而实验组随吸氧时间逐渐延长,电位越来越高,停止吸氧后,电位迅速回落,Oxy20和post30(P=0.04)、Oxy50和post30(P=0.02)相比均有显著性差异。组间比较,4个时间点均无显著性差异(P0.05)。结论健康人吸60 min纯氧,可能缩短对刺激的反应时间,有增强听觉门控电位的趋势。     

In vivo anti-plasmodial activities and toxic impacts of lime extract of a combination of Picralima nitida,Alstonia boonei and Gongronema latifolium in mice infected with Chloroquine-sensitive Plasmodium berghei

Background

Lime extracts of powdered combination of seeds of Picralima nitida, stem bark of Alstonia boonei and leaves of Gongronema latifolium is a common remedy used in the treatment of malaria in South Western Nigeria.

Objective

To determine the antiplasmodial activities of the combined herbal extracts and its impact on the haematological, hepatological and renological parameters in mice.

Methods

The 4-day suppressive and curative tests were used to assess the antiplasmodial activities of the extract in mice infected with chloroquine-sensitive Plasmodium berghei at concentration of 200mg/kg, 400mg/kg and 800mg/kg body weight. The haematological parameters including red blood cells, white blood cells, packed cell volume and haemoglobin count were analysed with an auto analyser. The activities of alanine aminotransferase (ALT), aspartate aminotransferase (AST) and alkaline phosphatase (ALP) were determined, while urea, protein and creatinine were analysed by standard procedural methods.

Results

The 4-day suppressive test revealed that the test extract achieved percentage suppression of 39.0%, 41.6% and 54.68% for the 200mg/kg, 400mg/kg and 800mg/kg concentration respectively. Additionally, the curative test achieved a high percentage suppression of 80.97%, 83.84% and 86.16% at the 200mg/kg, 400mg/kg and 800mg/kg concentration respectively. The extracts did not induce significant change on haematological parameters (P>0.05), while significant elevation in the values of the ALT and AST (P<0.05) was observed and elevation of creatinine (P<0.05) at 800mg/kg.

Conclusions

The results support the traditional use of the herbal combination in the treatment of malaria, however the liver cells were impacted by the extracts in bioassay conducted with mice.     

Structural characterization of mRNA-tRNA translocation intermediates

Cryo-EM analysis of a wild-type Escherichia coli pretranslocational sample has revealed the presence of previously unseen intermediate substates of the bacterial ribosome during the first phase of translocation, characterized by intermediate intersubunit rotations, L1 stalk positions, and tRNA configurations. Furthermore, we describe the domain rearrangements in quantitative terms, which has allowed us to characterize the processivity and coordination of the conformational reorganization of the ribosome, along with the associated changes in tRNA ribosome-binding configuration. The results are consistent with the view of the ribosome as a molecular machine employing Brownian motion to reach a functionally productive state via a series of substates with incremental changes in conformation.     

Laminar flow reduces cases of surgical site infections in vascular patients

Introduction

Numerous strategies are employed routinely in an effort to lower rates of surgical site infections (SSIs). A laminar flow theatre environment is generally used during orthopaedic surgery to reduce rates of SSIs. Its role in vascular surgery, especially when arterial bypass grafts are used, is unknown.

Methods

A retrospective review of a prospectively maintained database was undertaken for all vascular procedures performed by a single consultant over a one-year period. Cases were performed, via random allocation, in either a laminar or non-laminar flow theatre environment. Demographic data, operative data and evidence of postoperative SSIs were noted. A separate subgroup analysis was undertaken for patients requiring an arterial bypass graft. Univariate and multivariate logistical regression was undertaken to identify significant factors associated with SSIs.

Results

Overall, 170 procedures were analysed. Presence of a groin incision, insertion of an arterial graft and a non-laminar flow theatre were shown to be predictive of SSIs in this cohort. In the subgroup receiving arterial grafts, only a non-laminar flow theatre environment was shown to be predictive of an SSI.

Conclusions

This study suggests that laminar flow may reduce incidences of SSI, especially in the subgroup of patients receiving arterial grafts.     

Growth hormone treatment in adults with Prader-Willi syndrome: the Scandinavian study

Prader-Willi syndrome (PWS) is characterized by short stature, muscular hypotonia, cognitive dysfunction, and hyperphagia usually leading to severe obesity. Patients with PWS share similarities with growth hormone deficiency (GHD). Few studies have dealt with growth hormone (GH) treatment in PWS adults. The purpose of the Scandinavian study was to evaluate the effects of GH on body composition, lipid and glucose metabolism, physical performance and safety parameters in adults with PWS. Twenty-five women and 21 men with PWS were randomized to treatment with GH or placebo during 1?year followed by 2?years of open labeled GH treatment. At baseline 1/3 had normal BMI, six patients severe GHD, ten impaired glucose tolerance and seven diabetes. At 1?year insulin-like growth factor I (IGF-I) SDS had increased by 1.51 (P?相似文献   

Compositional magnetic resonance imaging in the evaluation of the intervertebral disc: Axial vs sagittal T2 mapping

The aim of this study was to assess T₂ values of the lumbar intervertebral discs in the axial and sagittal plane views and assess their respective interobserver reliability. The lumbar intervertebral discs of 23 symptomatic patients (11 female; 12 male; mean age, 44.1 ± 10.6; range, 24-64 years) were examined at 3T. Region-of-interest (ROI) analysis was performed on axial and sagittal T₂ maps by two independent observers. Intraclass correlation coefficient (ICC) was assessed for every ROI. The interobserver agreement was excellent for the nucleus pulposus (NP) in the sagittal (0.951; 95% confidence interval [CI], 0.926-0.968) and axial (0.921; 95% CI, 0.845-0.955) planes. The posterior 20% region showed a higher ICC in the axial vs the sagittal assessment (0.845; 95% CI, 0.704-0.911 vs 0.819; 95% CI, 0.744-0.873). The same was true for the posterior 10%, with the axial ROI showing a higher ICC (0.923; 95% CI, 0.865-0.953 vs 0.628; 95% CI, 0.495-0.732). The intraobserver agreement was excellent for every ROI except the sagittal 10% region, which showed good performance (0.869; 95% CI, 0.813-0.909). The sagittal nucleus pulposus was the best-performing ROI with regard to intra- and interobserver agreement in the T₂ assessment of the lumbar intervertebral disc. However, the axial NP showed more stable agreements overall and across the value range. In addition, the annular analysis showed better inter- and intraobserver agreement in the axial plane view. Clinical significance: Based on the presented analysis, we highly recommend that further studies use axial T₂ mapping due to the higher intra- and interreader agreement.     

Karpale Begleitläsionen bei dislozierter distaler Radiusfraktur

Background

The functional outcome of surgically treated dislocated fractures of the distal radius is limited and does not correlate with radiographic results. Additional carpal lesions are assumed to be the cause. This study has evaluated which carpal lesions are associated with dislocated fractures of the distal radius.

Material and methods

A total of 104 consecutive patients with dislocated fractures of the distal radius were included in the study. The injured wrist was examined by radiography, computed tomography (CT) and magnetic resonance imaging (MRI) to determine additional carpal lesions.

Results

Radiographically 51 of the 104 fractures presented as type A according to the AO classification, 10 as type B and 39 as type C. The CT scan detected that only 5 of the 51 type A fractures were exclusively metaphyseal fractures. All type A fractures were associated with ligamental lesions in MRI.

Conclusions

The results of the study confirm the hypothesis that every dislocated fracture of the distal radius is a combined carpal trauma associated with additional osseous and/or ligamental lesions.     

Dietary Intake Relative to Cardiovascular Disease Risk Factors in Individuals With Chronic Spinal Cord Injury: A Pilot Study

Background:

The relationship between cardiovascular disease (CVD) risk factors and dietary intake is unknown among individuals with spinal cord injury (SCI).

Objective:

To investigate the relationship between consumption of selected food groups (dairy, whole grains, fruits, vegetables, and meat) and CVD risk factors in individuals with chronic SCI.

Methods:

A cross-sectional substudy of individuals with SCI to assess CVD risk factors and dietary intake in comparison with age-, gender-, and race-matched able-bodied individuals enrolled in the Coronary Artery Risk Development in Young Adults (CARDIA) study. Dietary history, blood pressure, waist circumference (WC), fasting blood glucose, high-sensitivity C-reactive protein (hs-CRP), lipids, glucose, and insulin data were collected from 100 SCI participants who were 38 to 55 years old with SCI >1 year and compared to 100 matched control participants from the CARDIA study.

Results:

Statistically significant differences between SCI and CARDIA participants were identified in WC (39.2 vs 36.2 in.; P < .001) and high-density lipoprotein cholesterol (HDL-C; 39.2 vs 47.5 mg/dL; P < .001). Blood pressure, total cholesterol, triglycerides, glucose, insulin, and hs-CRP were similar between SCI and CARDIA participants. No significant relation between CVD risk factors and selected food groups was seen in the SCI participants.

Conclusion:

SCI participants had adverse WC and HDL-C compared to controls. This study did not identify a relationship between consumption of selected food groups and CVD risk factors.Key words: cardiovascular disease risk factors, dietary intake, spinal cord injuryCardiovascular disease (CVD) is a leading cause of death in individuals with chronic spinal cord injuries (SCIs).^1–5 This is partly because SCI is associated with several metabolic CVD risk factors, including dyslipidemia,^6–10 glucose intolerance,^6,11–14 and diabetes.^15–17 In addition, persons with SCI exhibit elevated markers of inflammation^18,19 and endothelial activation²⁰ that are correlated with higher CVD prevalence.^21–23 Obesity, and specifically central obesity, another CVD risk factor,^24–26 is also common in this population.^12,27–29Dietary patterns with higher amounts of whole grains and fiber have been shown to improve lipid abnormalities,³⁰ glucose intolerance, diabetes mellitus,^31–34 hypertension,³⁵ and markers of inflammation³⁶ in the general population. These dietary patterns are also associated with lower levels of adiposity.³¹ Ludwig et al reported that the strong inverse associations between dietary fiber and multiple CVD risk factors – excessive weight gain, central adiposity, elevated blood pressure, hypertriglyceridemia, low high-density lipoprotein cholesterol (HDL-C), high low-density lipoprotein cholesterol (LDL-C), and high fibrinogen – were mediated, at least in part, by insulin levels.³⁷ Whole-grain food intake is also inversely associated with fasting insulin, insulin resistance, and the development of type 2 diabetes.^32,38,39Studies in the general population have also shown a positive association between the development of metabolic syndrome as well as heart disease and consumption of a Western diet, a diet characterized by high intake of processed and red meat and low intake of fruit, vegetables, whole grains, and dairy.^40,41 Red meat, which is high in saturated fat, has been shown to have an association with adverse levels of cholesterol and blood pressure and the development of obesity, metabolic syndrome, and diabetes.^40,42,43Numerous studies have shown that individuals with chronic SCI have poor diet quality.^44–49 A Canadian study found that only 26.7% of their sample was adherent to the recommendations about the consumption of fruit, vegetables, and grains from the “Eating Well with Canada’s Food Guide.”⁴⁴ Individuals with chronic SCI have also been found to have low fiber and high fat intakes when their diets were compared to dietary recommendations from the National Cholesterol Education Program,⁴⁶ the 2000 Dietary Guidelines for Americans,⁴⁹ and the recommended Dietary Reference Intakes and the Acceptable Macronutrient Distribution Range.^47,48However, unlike in the general population, the relationship between dietary intake and obesity and CVD risk factors is unknown in the chronic SCI population. If a dietary pattern consisting of higher intake of whole grains and dietary fiber is favorably associated with obesity and CVD risk factors in individuals with chronic SCI, then trials of increased intake of whole grains and fiber intake could be conducted to document health benefits and inform recommendations. The purpose of this pilot study is to investigate the association between selected food group intake and CVD risk factors in individuals with chronic SCI as compared to age-, gender-, and race-matched able-bodied individuals enrolled in the Coronary Artery Risk Development in Young Adults (CARDIA) study. Data will also be used to plan future studies in the relatively understudied field of CVD and nutrition in individuals with SCI.     

Electrophysiological changes in the canine atrium and ventricle during progressive hyperkalaemia: electrocardiographical correlates and the in vivo validation of in vitro predictions

The electrophysiological response to hyperkalaemia was reinvestigated in the whole dog for several reasons including: the paucity of comparative electrophysiological and electrocardiographical studies in which atrial and ventricular tissues were simultaneously investigated; the contrast between the clarity of findings in previous in vitro studies as compared with the rather conflicting results in earlier in vivo investigations; and the difficulty in validating the extrapolation from in vitro results and theory to the in vivo situation because of deficiences in the literature. Biphasic alterations in atrial and ventricular conduction times as well as excitability in response to progressively increasing hyperkalaemia were documented. The alterations in conduction times were reflected quite accurately by relevant electrocardiographical changes. Experiments in the whole animal were designed to test predictions based on membrane theory: the results offering strong support for the validity of extrapolating from the in vitro to the in vivo situation. The results of this study should help clarify and render interpretable many of the seemingly conflicting results in the literature.     

Fluorescence in situ hybridization mapping of translocations and deletions involving the short arm of human chromosome 12 in malignant hematologic diseases

Translocations and deletions of the short arm of chromosome 12 [t(12p) and del(12p)] are common recurring abnormalities in a broad spectrum of hematologic malignant diseases. We studied 20 patients and one cell line whose cells contained 12p13 translocations and/or 12p deletions using fluorescence in situ hybridization (FISH) with phage, plasmid, and cosmid probes that we previously mapped and ordered on 12p12-13. FISH analysis showed that the 12p13 translocation breakpoints were clustered between two cosmids, D12S133 and D12S142, in 11 of 12 patients and in one cell line. FISH analysis of 11 patients with deletions demonstrated that the deletions were interstitial rather than terminal and that the distal part of 12p12, including the GDI-D4 gene and D12S54 marker, was deleted in all 11 patients. Moreover, FISH analysis showed that cells from 3 of these patients contained both a del(12p) and a 12p13 translocation and that the affected regions of these rearrangements appeared to overlap. We identified three yeast artificial chromosome (YAC) clones that span all the 12p13 translocation breakpoints mapped between D12S133 and D12S142. They have inserts of human DNA between 1.39 and 1.67 Mb. Because the region between D12S133 and D12S142 also represents the telomeric border of the smallest commonly deleted region of 12p, we also studied patients with a del(12p) using these YACs. The smallest YAC, 964c10, was deleted in 8 of 9 patients studied. In the other patient, the YAC labeled the del(12p) chromosome more weakly than the normal chromosome 12, suggesting that a part of the YAC was deleted. Thus, most 12p13 translocation breakpoints were clustered within the sequences contained in the 1.39 Mb YAC and this YAC appears to include the telomeric border of the smallest commonly deleted region. Whether the same gene is involved in both the translocations and deletions is presently unknown.