Thoracic paravertebral nerve block.
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Biomedical subjects
Publications and source records attributed to S Cheema.
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Workplace bullying in health systems is a well known fact. It leads to not only breakdown in teamwork but also has significant affect on the individual's personal life. True prevalence of bullying in junior doctors working in Ireland is unknown. Our aim of study was to find out the prevalence of bullying in junior doctors working hospitals in south and western counties of Ireland and to assess its effects on the productivity of work and family life and to identify the common source of bullying. We carried out a questionnaire survey. A total of 950 questionnaires were sent. Response rate was 51%. Our sample is 15% of the target population of all the hospital junior doctors. 30% of the responders claimed to be subjected to one or more bullying behaviors. Doctors from European Union (EU) reported significantly less rate of bullying compares to non EU doctors. Our results are in line with the results of studies conducted in United Kingdom. This study shows the magnitude and source of the problem. We conclude that bullying is a common problem in Irish health system. Increased awareness and zero tolerance are required to eradicate bullying.
Factors affecting the spread of bupivacaine in the paravertebral space were investigated in patients undergoing paravertebral nerve blocks for the treatment of chronically painful conditions. Injections of bupivacaine 0.5%, 10-15 ml mixed with depomedrone up to 80 mg were repeated at 2-wk intervals up to a maximum of four times. A blinded observer mapped out the subsequent distribution of sensory loss to cold on both sides of the torso at 5-min intervals after each injection. Age, sex, height and weight did not correlate with the block; nor did injectate volume, mass of bupivacaine, previous posterolateral thoractomy and spread of radiocontrast. Injections repeated at 2-wk intervals in the same patient resulted in different degrees of spread that were unrelated to one another. Time to peak onset of blockade was 40 min in 95% of patients. A single bolus of bupivacaine produces a safe but unpredictable block. Yet to be defined physical properties and anatomical factors are probably key determinants of the spread of bupivacaine in the paravertebral space. This single bolus technique may be better supplanted by a reversion to the older multiple level injection technique.
All 38 patients listed for day-case spinal endoscopy over a 12-month period (April 1998 - April 1999), who had chronic severe low back pain with a radiculopathic element, were studied prospectively. The mean [range] pain duration before treatment was 10.9 [2-26] years and 50% had failed back surgery syndrome. In all patients in whom treatment was completed (n = 34), the pain-generating nerve roots were located through symptom interaction with the patient. All had epidural scar tissue, 14 (41%) having dense adhesions. Mobilisation of adhesions around the nerve root (neuroplasty) was performed so that a pocket was formed for the subsequent placement of bupivacaine, Depomedrone and clonidine. No intra-operative complications occurred and side-effects were minimal. Follow-up over a 12-month period showed statistically significant reductions in pain scores and disability. Spinal endoscopy may be the diagnostic method of choice for epidural fibrosis. It has substantial therapeutic and research potential. Prospective randomised studies are required.
The inositol-polyphosphate 5-phosphatase enzyme family removes the 5-position phosphate from both inositol phosphate and phosphoinositide signaling molecules. We have cloned and characterized a novel 5-phosphatase, which demonstrates a restricted substrate specificity and tissue expression. The 3.9-kb cDNA predicts for a 72-kDa protein with an N-terminal proline rich domain, a central 5-phosphatase domain, and a C-terminal CAAX motif. The 3. 9-kilobase mRNA showed a restricted expression but was abundant in testis and brain. Antibodies against the sequence detected a 72-kDa protein in the testis in the detergent-insoluble fraction. Indirect immunofluorescence of the Tera-1 cell line using anti-peptide antibodies to the 72-kDa 5-phosphatase demonstrated that the enzyme is predominantly located to the Golgi. Expression of green fluorescent protein-tagged 72-kDa 5-phosphatase in COS-7 cells revealed that the enzyme localized predominantly to the Golgi, mediated by the N-terminal proline-rich domain, but not the C-terminal CAAX motif. In vitro, the protein inserted into microsomal membranes on the cytoplasmic face of the membrane. Immunoprecipitated recombinant 72-kDa 5-phosphatase hydrolyzed phosphatidylinositol 3,4,5-trisphosphate and phosphatidylinositol 3, 5-bisphosphate, forming phosphatidylinositol 3,4-bisphosphate and phosphatidylinositol 3-phosphate, respectively. We propose that the novel 5-phosphatase hydrolyzes phosphatidylinositol 3,4, 5-trisphosphate and phosphatidylinositol 3,5-bisphosphate on the cytoplasmic Golgi membrane and thereby may regulate Golgi-vesicular trafficking.
Schwann cells express the low-affinity neurotrophin receptor (p75), but no role for either the neurotrophins or their cognate receptors in Schwann cell development has been established. We have found that Schwann cells isolated from postnatal day 1 (P1) or P2 mice that were p75-deficient exhibited potentiated survival compared to wild-type cells after growth factor and serum withdrawal. There was, however, no disparity in the survival of p75-deficient and wild-type Schwann cells isolated at embryonic day 15, suggesting that the death-inducing effects of p75 are developmentally regulated. A comparable degree of cell death was also observed in the sciatic nerves of both wild-type and p75-deficient mice at P1. However, 24 hr after axotomy, there was a 13-fold increase in the percentage of apoptotic nuclei in the distal nerve stumps of the transected sciatic nerves of neonatal wild-type but not p75-deficient mice. The expression of both the p75 and nerve growth factor (NGF) genes was upregulated after axotomy in neonatal wild-type nerves. Collectively, these results suggest that NGF-mediated activation of p75 is likely to be an important mediator of Schwann cell apoptosis in the context of peripheral nerve injury.
In schizophrenia reduction of the P300 amplitude is a robust statistical finding but with inconsistent evidence of symptom correlates and of lateral asymmetry. Here relations were examined with active and withdrawn syndromes which in other cognitive and electrophysiological measurement modalities have been associated with opposite functional asymmetries. A standard oddball detection task was used to elicit auditory evoked potentials from dextral DSM-IV schizophrenic patients. On clinical ratings blind to the psychophysiology, eight were classified as withdrawn and 12 had a predominance of active syndrome features. Both patient groups had congruent P300 maxima at Pz or P4, attesting to their application to the detection task. Syndromes were differentiated by opposite asymmetries in P300, N200-P300 and N100 amplitudes at the posterior temporal sites: a reduction in P300 and N200-P300 amplitudes on the left in the active patients, and a reduction on the right in the withdrawn patients, with the opposite asymmetries in N100 amplitudes. The syndrome-related asymmetries in P300, also manifested in earlier attentional (N100) components are interpreted in terms of thalamo-cortical arousal systems having generalised, internalised influences, rather than in terms of later cognitive processes underpinning the P300. The findings endorse a syndromal approach to laterality research in schizophrenia.
Both epidural and paravertebral blocks are effective in controlling post-thoracotomy pain, but comparison of preoperative and balanced techniques, measuring pulmonary function and stress responses, has not been undertaken previously. We studied 100 adult patients, premedicated with morphine and diclofenac, allocated randomly to receive thoracic epidural bupivacaine or thoracic paravertebral bupivacaine as preoperative bolus doses followed by continuous infusions. All patients also received diclofenac and patient-controlled morphine. Significantly lower visual analogue pain scores at rest and on coughing were found in the paravertebral group and patient-controlled morphine requirements were less. Pulmonary function was significantly better preserved in the paravertebral group who had higher oxygen saturations and less postoperative respiratory morbidity. There was a significant increase in plasma concentrations of cortisol from baseline in both the epidural and paravertebral groups and in plasma glucose concentrations in the epidural group, but no significant change from baseline in plasma glucose in the paravertebral group. Areas under the plasma concentration vs time curves for cortisol and glucose were significantly lower in the paravertebral groups. Side effects, especially nausea, vomiting and hypotension, were troublesome only in the epidural group. We conclude that with these regimens, paravertebral block was superior to epidural bupivacaine.
The lymphocyte cell surface antigen CD38, which was originally described as a differentiation marker, has emerged as an important multifunctional protein. Its most intriguing and well characterized function is its ability to catalyze the synthesis of cyclic ADP-ribose (cADPR) from NAD. cADPR serves as an important second messenger in controlling the release of intracellular calcium from ryanodine-sensitive intracellular pools. By virtue of its ability to synthesize cADPR as well as to act as an adhesion and signal transduction molecule, CD38 may play a role in such diverse physiological processes as cell growth, apoptosis, differentiation, and inflammation. Equally interesting is the pattern of CD38 expression in hematopoietic cells. In the bone marrow, early precursor cells predominantly express CD38 antigen, whereas mature circulating blood cells lack or express very low levels. The expression is also high on malignant hematopoietic cells and thus may be of prognostic relevance in certain leukemias. Presently, there is little information available on the factors that regulate the expression of CD38 antigen in hematopoietic cells. In this review, we summarize recent findings on the regulation of CD38 antigen by retinoids (vitamin A and related compounds). At least in the myeloid cell lineage, retinoids appear to be exquisitely potent and specific inducers of CD38 antigen expression, and retinoid-induced expression of CD38 is mediated via activation of the retinoic acid-alpha (RAR alpha) nuclear receptor.
A female child is described with deletion of chromosome 18 and cardiomyopathy. The clinical features and treatment of the case are described, and the literature of chromosome 18 reviewed.
OBJECTIVE: To determine dependent chest tube losses of bupivacaine with paravertebral versus interpleural administration, thereby helping to explain the significant differences in pulmonary function that exist between these two techniques. DESIGN: A prospective, randomized study. SETTING: A single hospital. PARTICIPANTS: Twelve adult patients undergoing posterolateral thoracotomies. INTERVENTIONS: Paravertebral or interpleural administration of bupivacaine. MEASUREMENTS AND MAIN RESULTS: Analgesia, as assessed by visual analog pain scores and patient-controlled morphine requirements, was similar in both groups. Postoperative spirometric values were significantly better at most times with the paravertebral route of administration. Dependent chest tube bupivacaine losses were approximately four times higher in the interpleural group. CONCLUSION: Local anesthetic on the diaphragm might actively impair respiratory function through diaphragmatic and abdominal muscle weakness, while failing to contribute to pain relief.
A number of different cytokines, each initially characterized on the basis of very different biological activities, all have very similar signalling pathways and share a similar tertiary structure. These cytokines include leukaemia inhibitory factor, ciliary neuronotrophic factor, oncostatin M, growth-promoting activity and cardiotrophin 1. They all have been found to regulate a number of properties of cells of the developing and mature nervous system in vitro and thus are neuroregulatory cytokines. The actions of these cytokines include regulation of neurotransmitter phenotype, differentiation of neuronal precursor cells both in the peripheral nervous system and in the spinal cord, survival of differentiated neurons, and regulation of development of both astrocytes and oligodendrocytes. In addition, studies in animal models show that these factors can rescue sensory and motor neurons from axotomy-induced cell death, which suggests that they can act as trauma factors for injured neurons. Analysis of the expression patterns of the different neuroregulatory cytokines and their receptors reveals that the receptors are expressed throughout nervous system development and following trauma, whereas the cytokines show temporal and spatial specific expression patterns. This is consistent with the idea that specific cytokines have specific roles in neural development and repair, but that their signalling pathways are shared. The phenotypes of the receptor knockouts show clear deficits in nervous system development, indicating a crucial role for LIF receptor signalling. Knockouts of individual cytokines are less dramatic, but LIF and CNTF knockouts do reveal deficits in maintenance of motor neurons or following trauma. Thus, whereas LIF and CNTF have clear roles in maintenance and following trauma, it is unclear which of the cytokines is involved in nervous system development. In clinical terms, these findings add further support to the use of these cytokines in nervous system trauma and disease.
Genetically obese (ob/ob) mice display a variety of metabolic differences from lean litter mates. In the obese state, fatty acid desaturation-elongation in brown adipose tissue mitochondria is apparently altered, resulting in differences in membrane fatty acid composition. This change in membrane lipid environment appears to influence GDP binding and therefore the activity of the proton conductance pathway associated with regulation of energy expenditure in these animals. In liver, binding of insulin to the nuclear membrane is increased by feeding a high polyunsaturated/saturated (P/S) diet fat. Consumption of a high P/S diet decreased mRNA levels for fatty acid synthase, acetyl-CoA carboxylase, malic enzyme, and pyruvate kinase in obese and lean animals. Expression of mRNA for these lipogenic enzymes was higher in obese animals and suggests that obese mice may be resistant to polyunsaturated fatty acid feedback control of gene expression.
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In vitro maturation of goat follicular oocytes in TALP medium supplemented with variable concentrations of luteinizing hormone (LH) [5-20 micrograms/ml] and estradiol [1 microgram/ml] was studied. Incubation of viable oocytes was carried out at 38.5 degrees C under liquid paraffin in 5% carbon dioxide/air mixture for 24 h. At 0 h all the oocytes were in germinal vesicle (GV) stage, each with a good cumulus. The cumulus expansion increased linearly with increasing concentrations of LH and a fixed concentration of estradiol [1 microgram/ml] at 24 h of incubation. Germinal vesicle breakdown (GVBD) was observed in 28% of the oocytes at 5 micrograms/ml concentration of LH and the same increased to 87% at 10 micrograms/ml of LH with 13% oocytes at metaphase II. At 20 micrograms/ml of LH, 45% of the oocytes were at metaphase II and the rest were at metaphase I. LH and estradiol seem to be important for acquisition of maturation competence in goat follicular oocytes.
The cytokine leukaemia inhibitory factor (LIF) favours the survival and growth of axons in vitro. The efficacy of this factor in the in vivo model has been the aim of this study. Following nerve transection and immediate entubulation repair in the rat sciatic nerve, this study demonstrated that (1) LIF promotes the growth of a population of axons of greater cross-sectional area after 6 and 12 weeks in comparison to either saline (negative control) or basic fibroblast growth factor (bFGF) (positive control), (2) LIF improves the nerve conduction velocity of regenerating axons, (3) LIF has a positive effect on skeletal muscle mass following nerve repair, (4) the benefits of LIF on skeletal muscle appear to be somewhat independent of reinnervation as similar observations are made where there is no growth of a tissue bridge within the tube, and (5) the effects of LIF seem to be potentiated by the addition of fibronectin.
Insulin binding and insulin responsiveness are altered by dietary fat-induced changes in the fatty acid composition of the adipocyte plasma membrane. Feeding a high P/S diet increased polyunsaturated fatty acid content of major membrane phospholipids of adipocyte plasma membrane in normal and diabetic animals, increased membrane linoleic acid content, and prevented a decrease in arachidonic acid level in diabetic animals. The high P/S diet increased insulin binding in control animals. Animals fed the high P/S diet had significantly higher rates of insulin-stimulated glucose transport and lipogenesis than did animals fed the low P/S diet. Feeding a high P/S diet significantly increased the amount of glucose transported when expressed as a function of the specific amount of insulin bound. To determine if dietary fat-induced alterations in the fatty acid composition of skeletal muscle lipid alter insulin-dependent and basal muscle metabolism, contralateral epitrochlearis and extensor digitorum longus muscles were isolated and incubated in vitro. High levels of dietary omega-3 fatty acids reduced PGE2 and PGF2 alpha synthesis in extensor digitorum longus and epitrochlearis muscle. Insulin increased glucose and amino acid transport; the increase in glucose transport by insulin was significantly greater after consumption of the high omega-3 fatty acid diet. Rats fed high levels of omega-3 fatty acids showed reduced net protein degradation in the presence and absence of insulin due to decreased rates of protein degradation and synthesis. These experiments indicate that high levels of dietary omega-3 fatty acids alter muscle membrane composition, glucose transport, and metabolism of muscle protein. To determine if dietary fatty acids alter the onset of diabetes and insulin binding to liver nuclei in spontaneously diabetic rats, weanling rats were fed chow or semipurified diets containing 20% (w/w) fat of either high or low P/S ratio. Feeding a high P/S diet increased insulin binding to liver nuclei of control and diabetic animals. Although diet did not alter the onset of diabetes, insulin binding to liver nuclei is higher in animals at the onset of diabetes than in highly diabetic animals. Eight-week-old female C57 B 6J lean and ob/ob mice were fed semipurified diets containing 20% (w/w) fat of either high or low P/S ratio to investigate the effect of diet on specific binding of insulin to liver nuclei. Insulin binding was highest in nuclei from lean mice fed a high P/S diet. Specific binding of insulin to nuclei from obese mice was also increased by the high P/S diet, but to a lesser extent.(ABSTRACT TRUNCATED AT 250 WORDS)
Evidence indicates that principal features of the membrane involve structural organization of lipids in the form of a bilayer with functional proteins either bound to the bilayer surface or inserted into the bilayer and interacting within specific domains in the lipid milieux. In homeotherms, intrinsic and extrinsic factors apparently form the basis for determination of membrane lipid composition and thus membrane physicochemical properties. Moreover, many intrinsic metabolic controls, such as fatty acid desaturation and phospholipid biosynthesis, may be attenuated by change in the nature of the extrinsic or dietary influence. This review will focus on the role of dietary fat as a determinant of subcellular structural constituents to illustrate that feeding nutritionally adequate diets differing in fatty acid composition can induce physiological transitions in membrane function involving the activity of enzymes responsible for synthesis of membrane constituents, hormone-activated functions and expression of activity in the cell nucleus.