Loss of T-type Calcium Current in Sensory Neurons of Rats with Neuropathic Pain

Background: Pathophysiology in the primary sensory neuron may contribute to chronic neuropathic pain. Ca channels play a central role in neuronal processes, and sensory neurons are rich in low-voltage-activated calcium channels (LVACCs). However, the physiologic function of these channels is unknown. Their possible role in rebound burst firing makes them a candidate for increased excitability after neuropathic injury.

Methods: This study uses pharmacological methods to isolate LVACC in cells from the dorsal root ganglia of neuropathic and sham-operated rats, including the blockade of high-voltage-activated Ca channels with fluoride and selective toxins. LVACCs were examined with conventional whole cell patch clamp electrophysiology techniques.

Results: After chronic constriction injury of the peripheral axon, LVACC was significantly reduced compared to sham rats as shown by a 60% reduction in peak current density and an 80% reduction in total calcium influx. A depolarizing shift in the voltage dependence of activation and an increase in the rate of deactivation and inactivation appear to cause this reduction of LVACC. Either Ni2+ or mibefradil, blockers of LVACC, applied in the bath to normal dorsal root ganglion cells during current clamp significantly and reversibly increased excitability.     

HLA-DR expression in macaque neuroendothelial cells in vitro and during SIV encephalitis

HLA-DR expression in neuroendothelial cells (NEC) was studied during the course of SIV encephalitis in rhesus monkeys. HLA-DR determinants were detected on NEC in monkeys with SIV encephalitis, but not in control animals. In situ hybridization with an SIV probe indicated that HLA-DR expression was not a consequence of SIV replication within NEC. Cultured rhesus NEC stimulated with gamma interferon expressed HLA-DR to a higher degree than cultured brain fibroblasts or astrocytes. These data support the contention that NEC participate in retrovirus-induced inflammation and autoimmunity within the central nervous system.     

Legionella in cooling towers.

Legionellosis (Legionnaires' disease and Pontiac fever) outbreaks have been associated with aerosols ejected from contaminated cooling towers--wet-type heat rejection units (WTHRUs) used to dissipate unwanted heat into the atmosphere. The Vermont Department of Health undertook a program to inventory, inspect, and sample all WTHRUs in Vermont from April 1981 to April 1982. All WTHRUs were sampled for Legionella pneumophila and data were obtained for location, design, construction, and operating characteristics. Of the 184 WTHRUs operating, statistical analyses were performed on those 130 which were sampled for L. pneumophila only once during the study period. Of these, 11 (8.5%) were positive for L. pneumophila. Sources of makeup water and period of operation had significant association with the recovery of L. pneumophila. Five out of 92 towers (5.4%) utilizing surface water sources for cooling were positive for L. pneumophila, in contrast to 6 positive towers of the 38 units (15.8%) which obtained makeup water from ground water sources (p = .054 by chi-square test). Nearly 15% of the 54 units which operated throughout the year were positive, compared to less than 4% of the 76 towers operating seasonally (p = .03 by chi-square test). The mean pH of the cooling water in units where L. pneumophila was recovered (8.3) was significantly higher than the mean pH of 7.9 in units testing negative (p less than .05 by t-test). In addition, the mean log-transformed turbidity of positive towers, 0.03 nephelometric units (ntu), was significantly lower than the mean of log turbidity of negative towers, 0.69 ntu (p less than .02 by t-test).     

骨骼肌的生物力学

骨骼肌能产生力和运动,肌肉的收缩与运动的激发完美协调。本文回顾骨骼肌的生物力学特点,描述力的产生和力通过肌细胞的传递。首先描述正常的肌肉结构特征和不同的肌肉结构形式,随后讨论肌肉的功能及其结构对功能的影响,分析收缩蛋白与中间肌丝在力从细胞内肌小节传递到细胞外基质过程中的相互作用。     

Radical prostatectomy: anatomical predictors of success or failure

A total of 143 patients underwent radical prostatectomy. Surgical specimens were evaluated with respect to local extent of disease, Gleason grade of the primary and relative nuclear roundness of the surgical specimen. The probability of disease control in the total population was 88 per cent at 5 years. Only 8 per cent of the patients who had disease confined to the specimen failed compared to 14 per cent of those who demonstrated extension outside of the surgical margins. The incidence of failure increased as a function of seminal vesicle involvement. Seminal vesicle involvement was greatest among patients with a Gleason grade greater than 7. Postoperative radiation did not offer any apparent advantage in patients with positive margins.     

Comparison of Methodologies for Calculating Quality Measures Based on Administrative Data versus Clinical Data from an Electronic Health Record System: Implications for Performance Measures

New reimbursement policies and pay-for-performance programs to reward providers for producing better outcomes are proliferating. Although electronic health record (EHR) systems could provide essential clinical data upon which to base quality measures, most metrics in use were derived from administrative claims data. We compared commonly used quality measures calculated from administrative data to those derived from clinical data in an EHR based on a random sample of 125 charts of Medicare patients with diabetes. Using standard definitions based on administrative data (which require two visits with an encounter diagnosis of diabetes during the measurement period), only 75% of diabetics determined by manually reviewing the EHR (the gold standard) were identified. In contrast, 97% of diabetics were identified using coded information in the EHR.The discrepancies in identified patients resulted in statistically significant differences in the quality measures for frequency of HbA1c testing, control of blood pressure, frequency of testing for urine protein, and frequency of eye exams for diabetic patients. New development of standardized quality measures should shift from claims-based measures to clinically based measures that can be derived from coded information in an EHR. Using data from EHRs will also leverage their clinical content without adding burden to the care process.