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1.
Automatic analysis of electromyography (EMG) signals, first operated in 1950 with analogic machines, steeply expanded from 1980 when fast computers and worthwhile programs became available. On-line measurement of response area and latency, averaging of low amplitude waves, fast sorting of motor unit potential shape parameters, computation of the “jitter” between two muscle fibers, turns/amplitude and spectral analysis of interferential pattern records, are some examples of programs currently offered in modern EMG machines. Other techniques are still reserved for research purposes: scanning EMG, decomposition of nerve and muscle compound potentials, measurement of the threshold and firing rate of motor units, trace analysis using tracking models. Finally, the credit for artificial intelligence systems (knowledge based systems, fuzzy logic, neuronal networks) is still not clearly stated. 相似文献
2.
We describe three families to highlight the variability of expression and penetrance that can occur in the craniosynostoses. In two of the families, gene carriers were only identified in retrospect by looking at photographs of other family members. In the third family, identical twins were initially thought to be discordant for sagittal craniosynostosis until early skull x rays were examined and both were found to be affected. The dilemmas faced when counselling these families are discussed. 相似文献
3.
Dexamethasone alters TNF-alpha expression in retinopathy 总被引:3,自引:0,他引:3
TNF-alpha has been found in the retina. Hyperoxia and hypoxia regulate TNF-alpha expression. TNF-alpha is an important factor in inflammation and angiogenesis. Dexamethasone inhibits TNF-alpha production. Changes in TNF-alpha expression in the retina may play an important role in the development of oxygen-induced retinopathy. Oxygen-induced retinopathy was produced in C57BL6 mice by exposure to 75% oxygen at Postnatal Day 7 (P7) for 5 days and the mice recovered in room air until Day 17 (P17). Dexamethasone was administered at 0.5 mg/kg/day once daily subcutaneously during the 5 days of oxygen exposure. TNF-alpha expression was evaluated at Day 7 prior to oxygen exposure, at Day 12 (P12) immediately upon removal from oxygen, and at Day 17, the time of maximal vasoproliferation by RT-PCR. TNF-alpha is developmentally regulated in the retinae of C57BL6 mice. From P7 to P12, there is a 3-fold increase in TNF-alpha expression and from P7 to P17 there is a 2.7-fold increase. There was 2.7-fold suppression in expression immediately following oxygen exposure at P12. The expression was dramatically increased at P17, the time of maximal vasoproliferation. Dexamethasone inhibited the expression of TNF-alpha at P17 by 6.4-fold. At this dose, it also suppressed the baseline TNF-alpha expression in the mouse model. In summary, TNF-alpha is altered in the development of oxygen-induced retinopathy in the mouse. It increased markedly during the vasoproliferative phase and was suppressed by dexamethasone. Modulation of TNF-alpha expression may provide a potential site of action for future therapeutic targets. 相似文献
4.
Stéphane Genet Raymond T. Kado 《Pflügers Archiv : European journal of physiology》1997,434(5):559-567
The contribution of the Na/K ATPase (pump) current to the polarization of the Purkinje cell has been studied using slices
of the rat cerebellum by blocking the pump with dihydro-ouabain (DHO) while recording the membrane potential with microelectrodes
in the somata. From our recordings, it appeared that blocking the pump depolarized the Purkinje cells more rapidly than might
be expected from shifts in Na+ and K+ concentrations, suggesting the removal of a hyperpolarizing current. Application of DHO, in the presence of tetrodotoxin (TTX),
led to calcium spike firing and plateau-like discharges suggesting activation of voltage-dependent calcium channels in the
dendrites. Adding 2 mM Co2+ to the medium did not prevent the depolarizations. Removing calcium from the bathing medium containing 2 mM Co2+ blocked the spiking activity but DHO application still produced a depolarization. Experiments to measure the current inhibited
by DHO indicated that the Na/K pump supplies a constant current of 240 pA. Substitution of the sodium with choline produced
a hyperpolarization, during which DHO had no effect on the membrane potential. Substitution of the sodium with lithium produced
only a slowly developing depolarization. It is concluded that in the cerebellar Purkinje cell, a continuous sodium ion influx
activates the pumps which produce a current that directly contributes to the membrane polarization. Possible pathways for
this sodium influx are discussed.
Received: 3 April 1997 / Received after revision and accepted: 12 May 1997 相似文献
5.
Use of 3-(4,5-Dimethylthiazol-2-yl)-2,5-Diphenyl Tetrazolium Bromide for Rapid Detection of Rifampin-Resistant Mycobacterium tuberculosis 总被引:4,自引:0,他引:4
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Robert N. Mshana Genet Tadesse Getahun Abate Hkan Mirner 《Journal of clinical microbiology》1998,36(5):1214-1219
We describe a test which uses the ability of viable cells to reduce 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) to detect resistance to a bactericidal drug, rifampin, in in vitro-cultured Mycobacterium tuberculosis. The assay shows a linear relationship between the number of viable bacteria and the ability to reduce MTT. Dead mycobacteria were unable to reduce MTT. Rifampin-sensitive M. bovis (BCG) and M. tuberculosis exposed to rifampin showed a rifampin concentration-dependent inhibition of the ability to reduce MTT, while the resistant strains were unaffected. The inhibition of MTT reduction after treatment with rifampin paralleled the reduction in the number of CFU. By using mixing experiments in which the population percentages of rifampin-sensitive and -resistant strains were varied, the assay could detect the presence of rifampin resistance in the mixture when at least 1% of the bacterial population was composed of drug-resistant strains. The assay is cheap, can be visually read, and requires less than 3 days to obtain susceptibility results. The total time required to obtain results, from the time sputum is received in the laboratory, is, in most cases, less than 4 to 5 weeks, which is the time required for primary culture of the bacteria. The MTT assay could, in combination with a test to detect resistance to isoniazid, be a cheap and rapid screening method for multidrug-resistant M. tuberculosis that is affordable even by low-income countries where tuberculosis is a major public health problem. 相似文献
6.
Lovering Ruth; Middleton-Price Helen R.; O'Reilly Marie-Anne J.; Genet Sally A.; Parkar Mohammed; Sweatman Angela K.; Bradley Linda D.; Alterman Lesley A.; Malcolm Sue; Morgan Gareth; Levinsky Roland J.; Kinnon Christine 《Human molecular genetics》1993,2(2):139-141
Genetic linkage analysis has been instrumental in mapping thegene for X-linked agammaglobulinemia (XLA) to the proximal longarm of the human X chromosome, to Xq22. Due to the relativerarity of this disease the localization of the gene within Xq22has remained imprecise. We have investigated twenty-nine familiesaffected by XLA and have found no recombinants with the DXS178locus in over 30 informative meioses. DXS178 is now the mostreliable and informative locus for use in pre-natal diagnosisand carrier detection of XLA. In addition, we have identifiednew closely linked proximal and distal flanking markers forXLA, DXS442 and DXS101, respectively. These loci are separatedby 2cM, considerably reducing the extent of DNA within whichthe XLA locus can be contained. This will open up the way formore directed positional cloning efforts for the isolation ofthe XLA gene. 相似文献
7.
Therapeutic drug monitoring of risperidone using a new, rapid HPLC method: reappraisal of interindividual variability factors 总被引:11,自引:0,他引:11
Because of the enormous gap between premarketing studies in physically healthy subjects and clinical practice in patients, the present study reconsidered interindividual variability factors affecting risperidone concentrations under routine therapeutic drug monitoring conditions. The study included 92 patients, 27% of whom were 70 years or older. The patients received risperidone orally (dose range, 0.5-11 mg per day) and had concentrations of risperidone and the active metabolite 9-hydroxyrisperidone measured at steady state by a new, rapid, and sensitive method of high-performance liquid chromatography (HPLC). After normalization to a dose of 4 mg/day, median concentrations were 2.9 ng/ml (80% range, 0.9-27.9 ng/ml) for the parent compound and 24.1 ng/ml (80% range, 12.0-57.6 ng/ml) for the metabolite. When considering linear regression models, age was identified as a major source of interindividual variability, with expected increases of 340% and 220% for concentrations of parent compound and metabolite, with age increasing from 20 to 80 years. Body weight provided an additional significant contribution to the variability of 9-hydroxyrisperidone concentration, a 20-kg higher body weight associated with a concentration decrease of 23%. Serotonin-specific reuptake inhibitor (SSRI) comedication (fluoxetine, two patients; citalopram, two patients; paroxetine, one patient; fluvoxamine, one patient) was significantly associated with 4.6-fold higher concentrations of parent compound, in keeping with an inhibitory action on CYP2D6 enzyme. Significantly higher concentrations of 9-hydroxy-risperidone (+ 29%) were also observed in the 17 patients with biperiden comedication. Therapeutic drug monitoring data, collected in patients representative of the population for which the drug was intended, allowed us to quantify the dose reduction needed in elderly patients and thus provided valuable information in addition to the one collected during premarketing studies performed with strict inclusion and exclusion criteria. 相似文献
8.
Background
Tumor lysis syndrome (TLS) is a life-threatening emergency disorder, caused by an abrupt release of intracellular metabolites after tumor cell death. It is characterized by a series of metabolic manifestations, especially hyperuricemia, hyperkalemia, hyperphosphatemia and hypocalcemia. The aim of this study was to evaluate and characterize the incidence of tumor lysis syndrome among pediatric oncology patients before and after treatment.Methods
Hospital based prospective cohort study was conducted for 6 months on 61 newly diagnosed pediatric oncology patients. Socio-demographic data was collected by interview administered questionnaire. Patients were followed and the physical diagnosis, imaging and laboratory results were interpreted by senior physicians. Data was entered to and analyzed by SPSS version 23.Results
Among 61 pediatric oncology patients 39(63.9%) were males. The mean (±SD) age of the pediatric patients was 6.39 (±?3.67) years ranging from 2 months to 14 years. 29.5% of patients were found to have TLS. There were 11.5% and 18.0% of laboratory TLS (LTLS) and clinical TLS (CTLS) cases respectively. There were72.2% spontaneous and 27.8% treatment induced TLS cases with 23% and 21.3% cases of hyperuricemia and 4.9% and 6.6% cases of hyperkalemia incidence before and after treatment respectively. Only two patients died, in the study period, due to TLS.Conclusion
There was high incidence of TLS irrespective of socio-demographic variation among study participants, suggesting that children with cancer are at risk of developing TLS. As TLS is a life-threatening complication of malignancies, early identification of patients at risk and reducing morbidity and mortality is crucially important.9.
Solomon Aragie Sintayehu Gebresillasie Ambahun Chernet Ayalew Shiferaw Zerihun Tadesse Mulat Zerihun Nicole E. Varnado Sun Y. Cotter Dionna M. Wittberg Zhaoxia Zhou Elizabeth Kelly Callahan Scott D. Nash Kristen Aiemjoy Jeremy D. Keenan 《The American journal of tropical medicine and hygiene》2021,104(4):1271
10.
Eshetu Sata Andrew W. Nute Tigist Astale Demelash Gessese Zebene Ayele Mulat Zerihun Ambahun Chernet Berhanu Melak Kimberly A. Jensen Mahteme Haile Taye Zeru Melkamu Beyen Adisu Abebe Dawed Fikre Seife Zerihun Tadesse Elizabeth Kelly Callahan Jeremiah Ngondi Scott D Nash 《The American journal of tropical medicine and hygiene》2021,104(4):1278