Painful polyneuropathy in patients with and without diabetes: clinical, neurophysiologic, and quantitative sensory characteristics

OBJECTIVES: To study pain characteristics and peripheral nerve involvement in patients with painful diabetic and nondiabetic polyneuropathy in comparison with patients with non-painful polyneuropathy. PATIENTS AND METHODS: Fifty-five patients with polyneuropathy (37 with painful polyneuropathy, of whom 19 had diabetes and 18 had no diabetes; and 18 with painless polyneuropathy of different etiologies) were examined clinically using quantitative sensory tests and neurophysiology. Pain intensity and characteristics were analyzed by daily ratings on a 10-step verbal scale and by a questionnaire. RESULTS: Most patients experienced pain of more than one character. There was no clear difference in character or duration of pain between patients with and without diabetes. The mean value of the daily rating of pain intensity showed that pain was more severe in the evenings than in the mornings and that diabetic patients reported worse pain than nondiabetic patients. Thirty-two of the 37 patients with pain had paresthesias and/or dysesthesias, whereas only 7 of 18 patients without pain had paresthesias. Pain was always located in the feet, and, in most patients, also in the lower part of the legs. Some patients also experienced pain in the hands. Tactile sensibility, measured by quantitative tests, was more affected in both diabetic and nondiabetic patients with painful polyneuropathy compared with patients without pain (p = 0.02). Temperature, pain, and vibratory sensibility were equally affected in all patient groups. Nerve conduction velocity, amplitudes, and distal latency were equally affected in the pain group as compared with the control group, indicating that both thin and thick nerve afferents are affected in patients with painful as well as non-painful polyneuropathy and that etiology has no clear impact on nerve involvement. CONCLUSIONS: Neuropathy pain was always located in the feet and more severe in diabetic patients compared with patients with neuropathy pain of other etiologies. The authors also found evidence for a greater tactile sensibility involvement in patients with neuropathy pain, irrespective of etiology, whereas other quantitative sensibility and neurography parameters were equally affected in all patient groups.     

Behavioral and sensory changes after direct ischemia-reperfusion injury in rats.

Complex regional pain syndromes (CRPS) are disabling pain syndromes that can develop after trauma or minor tissue injury affecting a limb. Characteristics of CRPS are sensory signs and symptoms, autonomic abnormalities, trophic changes and an impaired motor function. Pathophysiological mechanisms for the development of CRPS are still a matter of investigation. Based on clinical data and investigations of CRPS patients it is hypothesized that tissue hypoxia and inflammation are important for the development of CRPS. The aim of the current study was therefore to examine if direct ischemia-reperfusion injury can induce behavior in rats with symptoms present in patients with CRPS. After baseline behavior measurements the femoral artery of Wistar rats was ligated for 3h with consecutive reperfusion. Sham-operated rats underwent the same preparation except ligation of the artery. Subsequent behavioral testing (observations of spontaneous pain behavior, paw withdrawal to mechanical, noxious mechanical, cold and heat stimuli) was performed up to two months after surgery. Both in rats that underwent ischemia and in sham-operated rats no obvious changes of hindpaw tissue were observed after ischemia-reperfusion injury (trophic changes, edema, differences in skin color or temperature). In behavioral tests only minor changes were observed, these being not different between postischemic rats and sham-operated rats. Using Wistar rats, our data do not support the idea that an ischemia-reperfusion injury can play a major role in the development of CRPS.     

The high-affinity HSP90-CHIP complex recognizes and selectively degrades phosphorylated tau client proteins

A primary pathologic component of Alzheimer's disease (AD) is the formation of neurofibrillary tangles composed of hyperphosphorylated tau (p-tau). Expediting the removal of these p-tau species may be a relevant therapeutic strategy. Here we report that inhibition of Hsp90 led to decreases in p-tau levels independent of heat shock factor 1 (HSF1) activation. A critical mediator of this mechanism was carboxy terminus of Hsp70-interacting protein (CHIP), a tau ubiquitin ligase. Cochaperones were also involved in Hsp90-mediated removal of p-tau, while those of the mature Hsp90 refolding complex prevented this effect. This is the first demonstration to our knowledge that blockade of the refolding pathway promotes p-tau turnover through degradation. We also show that peripheral administration of a novel Hsp90 inhibitor promoted selective decreases in p-tau species in a mouse model of tauopathy, further suggesting a central role for the Hsp90 complex in the pathogenesis of tauopathies. When taken in the context of known high-affinity Hsp90 complexes in affected regions of the AD brain, these data implicate a central role for Hsp90 in the development of AD and other tauopathies and may provide a rationale for the development of novel Hsp90-based therapeutic strategies.     

Health risks and occupational exposure to volatile anaesthetics--a review with a systematic approach

Aims and objectives. To provide practicing nurse anaesthetists with evidence based knowledge as to whether they are at risk handling volatile anaesthetics by answering the question: What are the health risks threatening health care personnel occupationally exposed to volatile anaesthetics? Background. The interpretations of results from specific scientific studies vary and preliminary research results indicate that occupational exposure to volatile anaesthetics affects the health of operating room personnel. Design. Review of scientific literature with a systematic approach. Method. The review included a systematic search in three major databases, a screening process of abstracts/articles followed by a quality assessment of the included studies. The screening process and the quality assessment were done independently by the six reviewers and followed specific protocols. Results. A systematic search of The Cochrane Library, MedLine and CINAHL resulted in a screening of 413 abstracts of which 31 articles were assessed for quality, all done independently by the reviewers. Finally, the reviewers agreed upon how to interpret the results of the assessed articles. Conclusions. The 31 articles assessed covered areas such as genotoxic effects, neurobehavioural effects, immunology, and general health effects. In the scientific literature reviewed there is no evidence of occupational exposure to volatile anaesthetics either being associated with health risks or being harmless. Studies indicating a potential health risk are all investigating circumstances ignorant of modern environmental regulations and/or with no scavenging equipment. Relevance to clinical practice. Although no answer has been given, this review illuminates the methodological difficulties encountered in designing studies. The result of this review further stresses the need for scientific knowledge in this area and enhances the extensive use of scavenging equipment.     

The association between tobacco smoking and surgical intervention for lumbar spinal stenosis: cohort study of 331,941 workers

Background Context

Tobacco smoking is an injurious habit associated with a number of chronic disorders. Its influence on disc metabolism and degeneration including lumbar spinal stenosis (LSS) has been investigated in the literature.

Outcome after acute respiratory failure is more dependent on dysfunction in other vital organs than on the severity of the respiratory failure

Introduction  

The incidence and outcome of acute respiratory failure (ARF) depend on dysfunction in other organs. As a result, reported mortality in patients with ARF is derived from a mixed group of patients with different degrees of multiorgan failure. The main goal of the present study was to investigate patient outcome in single organ ARF.     

Signal transducer of inflammation gp130 modulates atherosclerosis in mice and man

Liver-derived acute phase proteins (APPs) emerged as powerful predictors of cardiovascular disease and cardiovascular events, but their functional role in atherosclerosis remains enigmatic. We report that the gp130 receptor, which is a key component of the inflammatory signaling pathway within hepatocytes, influences the risk of atherosclerosis in a hepatocyte-specific gp130 knockout. Mice on an atherosclerosis-prone genetic background exhibit less aortic atherosclerosis (P < 0.05) with decreased plaque macrophages (P < 0.01). Translating these findings into humans, we show that genetic variation within the human gp130 homologue, interleukin 6 signal transducer (IL6ST), is significantly associated with coronary artery disease (CAD; P < 0.05). We further show a significant association of atherosclerotic disease at the ostium of the coronary arteries (P < 0.005) as a clinically important and heritable subphenotype in a large sample of families with myocardial infarction (MI) and a second independent population-based cohort. Our results reveal a central role of a hepatocyte-specific, gp130-dependent acute phase reaction for plaque development in a murine model of atherosclerosis, and further implicate IL6ST as a genetic susceptibility factor for CAD and MI in humans. Thus, the acute phase reaction should be considered an important target for future drug development in the management of CAD.     

The effect of diabetes on B-type natriuretic peptide concentrations in patients with acute dyspnea: an analysis from the Breathing Not Properly Multinational Study

OBJECTIVE: Diabetes has been implicated in reduced myocardial compliance and changes in the intercellular matrix of the myocardium. We determined the effect of diabetes on B-type natriuretic peptide (BNP) concentrations in patients presenting to the emergency department with dyspnea. RESEARCH DESIGN AND METHODS: The Breathing Not Properly Multinational Study was a prospective evaluation of 1,586 patients. A subset of 922 patients was obtained and subdivided into the following groups: group 1 (n = 324), neither diabetes nor heart failure; group 2 (n = 107), diabetes and no heart failure; group 3 (n = 247), no diabetes and heart failure; group 4 (n = 183), both diabetes and heart failure; group 5 (n = 41), heart failure history with no diabetes; and group 6 (n = 20), heart failure history with diabetes. Patients from groups 1, 3, and 5 were matched to groups 2, 4, and 6, respectively, to have the same mean age, sex distribution, BMI, renal function, and New York Heart Association (NYHA) classification (for heart failure). RESULTS: There was no significant difference in median BNP levels between diabetes and no diabetes among no heart failure patients (32.4 vs.32.9 pg/ml), heart failure patients (587 vs. 494 pg/ml), and those with a heart failure history (180 vs. 120 pg/ml). Receiver-operating characteristic curve analysis of the area under the curve for BNP was not different in diabetic versus nondiabetic patients (0.888 vs. 0.878, respectively). However, in a multivariate model, diabetes was an independent predictor of a final diagnosis of heart failure (odds ratio 1.51, 95% CI 1.03-2.02; P < 0.05). CONCLUSIONS: History of diabetes does not impact BNP levels measured in patients with acute dyspnea in the emergency department. Despite the impact of diabetes on the cardiovascular system, diabetes does not appear to confound BNP levels in the emergency department diagnosis of heart failure.     

Simultaneous measurement of beta-amyloid(1-42), total tau, and phosphorylated tau (Thr181) in cerebrospinal fluid by the xMAP technology

BACKGROUND: To simultaneously study several biomarkers for Alzheimer disease (AD), we used the xMAP technology to develop and evaluate a multiparametric bead-based assay for quantification of beta-amyloid((1-42)) [Abeta((1-42))], total tau (T-TAU), and hyperphosphorylated tau [P-TAU((181P))] in cerebrospinal fluid (CSF). METHODS: We compared the new multianalyte assay format with established ELISA techniques for the same proteins. We then performed a clinical study using CSF samples from patients with AD or mild cognitive impairment with progression to AD, healthy controls, and patients with other neurologic disorders. RESULTS: The INNO-BIA AlzBio3 selectively and specifically measured Abeta((1-42)), T-TAU, and P-TAU((181P)) in the CSF. The new assay format had intra- and interassay CVs <10% for all analytes, even at low concentrations. The measurement range of the new assay was 3 to 4 logs compared with 1 to 2 logs for ELISAs. By plotting the mean of the values obtained in ELISA and the xMAP technology against the difference, we found that a correction factor could be used to convert xMAP results to ELISA values. The clinical study demonstrated that the new multiparametric assay could accurately distinguish patients with AD from patients with other neurologic disorders or control patients, with the diagnostic accuracy reaching recommended consensus criteria for specificity and sensitivity. CONCLUSION: The new multiparametric method may be able to replace the corresponding ELISA methods.