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Biomedical subjects

C Becker

Publications and source records attributed to C Becker.

At least 343 records · Page 19Linked to original sources
PubMed1992

[Symptomatic cholecystolithiasis: 1992 therapy options].

Modern treatment of symptomatic cholecystolithiasis requires a knowledge of several nonsurgical and surgical treatment options. Extracorporeal shock-wave lithotripsy and oral bile acid therapy offer the possibilities of noninvasive, outpatient treatment in approximately 20% of all symptomatic gallstone patients at a low complication rate. The percutaneous interventional techniques such as contact dissolution by means of ether or mechanical stone removal may in principle be used in a higher percentage of patients but are considerably more invasive. None of the nonsurgical techniques can exclude the relative risk of gallstone recurrence. Laparoscopic cholecystectomy constitutes a major progress in the surgical treatment of gallstone disease, since it is much less invasive than conventional cholecystectomy and requires a much shorter hospital stay and recovery time. The laparoscopic technique is primarily indicated in patients with symptomatic, uncomplicated cholecystolithiasis. Nevertheless, the range of indications is expanding as experience with this technique increases. Under certain circumstances, laparoscopic cholecystectomy is already being combined with endoscopic sphincterotomy in the presence of bile duct calculi. Conventional cholecystectomy remains the treatment of choice for complicated cases.

Bile Acids and Salts↗
PubMed1992

[Leipzig Medical Society (founded in 1829)].

The Leipzig Medical Society was founded in 1829 by Justus Radius. More than 100 years this interdisciplinary association was a scientific and cultural centre which promoted scientific life and professional training of the municipal physicians and the university staff. Therefore the Leipzig Medical Society contributed to reputation of Leipzig as an cultural and scientific centre during the last years of the 19th and the beginning of the 20th century.

Germany↗
PubMed1991

The community hospital-based stroke programs in North Carolina, Oregon and New York--V. Stroke diagnosis: factors influencing the diagnostic evaluation of patients following acute stroke.

Among the 4129 patients of the Community Hospital-based Stroke Program, 30% had an unspecified stroke diagnosis. Since specific diagnosis and, perhaps, eventual treatment, derives in part from diagnostic testing, we examined the effect of clinical condition, geographic and demographic factors on the incidence of certain diagnostic tests after acute stroke. In this multivariable analysis, race, sex, history of hypertension and history of diabetes did not influence the chance of having any test, but older age strongly reduced the chances of receiving extensive evaluation. When CT scanning was available, the utilization of a CT as well as other diagnostic studies including cerebral angiography, radionuclide brain scan, EEG and EKG was increased. The odds of receiving a CT scan increased if the patient was married, and decreased with a history of previous stroke. A history of previous TIA increased the chance of having a cerebral angiogram while a history of cardiac disease decreased the chance. There were striking regional geographic differences in the use of CT, radionuclide brain scanning and cerebral angiography which may, in part, reflect differences between the availability of these technologies in urban and rural hospitals. These results indicate that evaluation of stroke patients remains heterogenous.

Aged↗
PubMed1991

Comparison of iohexol with barium in gastrointestinal studies of infants and children.

This study evaluates iohexol as a contrast agent in the gastrointestinal tract in children. In the first part of the study, iohexol in concentrations of 180 and 300 mg l/ml was compared in double-blind manner with barium. Sixty-four patients were studied. No significant difference in changes of blood pressure and pulse rate was found between the three groups of patients studied. Diarrhea was significantly more common in the children receiving iohexol than in children receiving barium. The diarrhea was not due to previously identified high-risk factors in the children, nor was it due to concurrent medication. When image quality was assessed in each anatomic region of the gastrointestinal tract, fewer nondiagnostic ratings occurred with barium than with iohexol. With barium, fewer ratings of poor mucosal coating and slightly fewer ratings of suboptimal contrast density occurred. The second part of the study was an open evaluation of iohexol 180 mg l/ml in 18 patients in whom barium was clinically contraindicated. Three of 53 assessments were nondiagnostic. Mucosal coating was poor in 6%, and contrast density was suboptimal in 8% of patients. The results of this study indicate that barium is the preferred contrast agent for routine evaluation of the gastrointestinal tract in children. Good-quality images can be obtained, however, with iohexol in concentrations of 180 or 300 mg l/ml, and iohexol is an excellent contrast agent for evaluation of the gastrointestinal tract in those patients in whom barium is relatively or absolutely contraindicated.

Adolescent↗
PubMed1991

[Clinical pharmacokinetics of lidocaine after intraoral nerve block].

Aim of this study was to show the time course of plasma concentrations of 2% lignocaine with adrenalin at a concentration of 1:100,000. Four retinated third molars were removed in one session in 23 patients. For local anaesthesia in each patient we used 10 ml of Xylocaine 2% (Astra), which is commonly used in dentistry. The plasma-concentration was measured for the first 30 minutes after injection of the local anaesthetic using high pressure liquid chromatography (HPLC). Our results suggest that partially intravascular injection could not be avoided although careful aspiration was carried out before injecting. Neither subjective nor objective adverse central nervous effects were seen in our patients. Nevertheless we consider a peripheral intravenous cannula and ECG-monitoring strongly recommended in all major operations under local anaesthesia.

Adolescent↗
PubMed1991

Fatal injuries at work in California.

We examined deaths due to injury on the job reported from three readily accessible data sources in California for a 1-year period. Of 682 deaths identified as of February 1990 as having occurred on the job in 1983, county coroners identified 607 (89.0%), workers' compensation records identified 294 (43.1%), and the California Occupational Safety and Health Administration investigated 141 (20.7%). Most fatal injuries at work resulted from events that are not covered by current California Occupational Safety and Health Administration standards: transportation vehicle accidents and homicides. Demographic patterns suggest that fatal injuries on the job are nonrandom events, which may be prevented by additions to existing standards or increased enforcement of workplace safety standards and by efforts to target groups at highest risk. Improved surveillance of fatal occupational injuries will require changes in existing reporting mechanisms, similar to those proposed by the US Bureau of Labor Statistics.

Accidents, Occupational↗
PubMed1990

Inhibition of palmitoyl co-enzyme A hydrolase in mitochondria and microsomes by pharmaceutical organic anions.

Rat microsomes and mitochondria were isolated and incubated with selected pharmaceutical organic anions at concentrations of 0, 0.2, 0.5, 1.0, and 2 mM. Activity of palmitoyl CoA hydrolase (PCAH) was shown to be reduced in a dose-dependent manner in microsomes by ibuprofen, valproate, acetyl salicylate, 2,4-dichlorophenoxyacetate (2,4-D), and 4-pentenoate, but not salicylate. Mitochondrial PCAH activity was inhibited by clofibrate, ibuprofen, valproate, and 2,4-D. Mitochondrial oxidative phosphorylation was impaired or uncoupled by each of the mitochondrial PCAH inhibitors. The inhibition of PCAH by some of these agents may lead to fatty acyl CoA accumulation. Very low concentrations of fatty acyl CoA are known to cause mitochondrial uncoupling and increase permeability. This action may play a role in the mitochondrial injury caused by some of these agents or related disease processes.

Animals↗
PubMed1990

Differential expression by nerve growth factor of two types of Ca2+ channels in rat phaeochromocytoma cell lines.

1. Two clones of rat phaeochromocytoma PC12 cells have been used to study the expression of Ca2+ channels and their possible involvement in neuronal differentiation. One clone differentiated morphologically when exposed to nerve growth factor (NGF) for 4 days (PC12 cells), while the other clone was insensitive to NGF, but differentiated morphologically in the presence of ouabain (0.1 mM) for 7 days (PC12-mutant cells). 2. Whole-cell Ba2+ currents through Ca2+ channels were measured in PC12 cells at a test potential (Et) of +10 mV, from two holding potentials (Eh) of -90 and -30 mV (I-90 and I-30). NGF-induced differentiation increased I-90 by 248% and I-30 by 133%. The cells that differentiate in the presence of ouabain had only small, if any, Ba2+ currents that did not appear to change during morphological differentiation or after the addition of NGF. 3. Barium currents in PC12 cells could be separated into two components by selective antagonists. The component of I-90 that could be inhibited by omega-conotoxin GVIA (omega-CgTX) in NGF-differentiated cells was 458 +/- 84 pA (mean +/- S.E.M.), compared with 79 +/- 44 pA in native cells. I-30 was reduced by 50 +/- 17 pA in NGF-treated cells and was virtually insensitive to the toxin in native cells. By contrast, the dihydropyridine (DHP) isradipine reduced I-30 in NGF-treated cells by 30 +/- 8 pA and in native cells by 20 +/- 3 pA. 4. Radioligand binding studies with 125I-omega-CgTX in PC12 cell membrane fragments and in PC12 cells showed a 2- to 3-fold increase in maximal binding capacity after NGF exposure, while mutant cells showed no such change in binding capacity after treatment with NGF or ouabain. Staurosporine inhibited the effect of NGF on 125I-omega-CgTX binding. [3H](+)-isradipine binding capacity was increased 1.8-fold by NGF in depolarized PC12 cells while no change was observed in mutant cells after NGF or ouabain. There was no interaction between omega-CgTX and DHP binding sites. 5. Both the electrophysiological and the binding data indicate a preferential expression of omega-CgTX-sensitive Ca2+ channels (N type) over isradipine-sensitive channels (L type) in PC12 cells treated with NGF. By contrast, ouabain-induced differentiation of a mutant PC12 cell line, that lacks functional NFG receptors, was not associated with the expression of Ca2+ channels.

Adrenal Gland Neoplasms↗
PubMed1990

Community hospital-based stroke programs in North Carolina, Oregon, and New York. IV. Stroke diagnosis and its relation to demographics, risk factors, and clinical status after stroke.

The use of diagnostic tests, the accuracy of stroke type diagnosis, and their relationship to outcome are important from the standpoint of patient management and health care costs. To address this issue, we examined the differences between stroke types in terms of demographics, risk factors, diagnostic tests, and clinical outcome in the 4,129 patients who comprise the Community Hospital-Based Stroke Program. Previous transient ischemic attacks were equally frequent among patients with embolic and those with thrombotic stroke. For all stroke types, previous stroke was as frequent as previous transient ischemic attacks. Hypertension and cardiac disease were the most common risk factors, but 10% of all stroke patients had no recognized risk factors. Intracerebral hemorrhage was most often associated with death (45%). There was a strong direct relation between in-hospital mortality and a decreased level of consciousness at admission. Overall, 30% of patients did not receive a specific stroke type diagnosis; these patients were elderly, usually nonwhite, and often had an altered level of consciousness at admission but had a risk factor profile similar to that of patients who received a specific stroke type diagnosis. In summary, our findings suggest the continued need for physician education about and refinement of stroke type diagnosis.

Aged↗
PubMed1989

The effects of a progestin-only oral contraceptive (levonorgestrel 0.03 mg) on breast-feeding.

This study was a non-randomized clinical trial which compared the breast-feeding experience of 250 Argentine women taking levonorgestrel 0.03 mg daily (begun one week after delivery) with that of 250 women using non-hormonal contraceptives. Weight gain of unsupplemented infants, the most important of the several criteria used to assess breast-feeding performance, was similar for the two contraceptive groups. Levonorgestrel users began supplementary feeding of their infants significantly later than did non-hormonal users; levonorgestrel users were also somewhat less likely to discontinue breast-feeding during the study period. The two contraceptive groups were similar with regard to several other measures of breast-feeding performance: growth of all infants (regardless of supplementation), patterns of contraceptive discontinuation, mothers' subjective impressions of breast-milk sufficiency, and comparison of supplementation initiation with previous experience.

Adult↗
PubMed1989

Changes in survival following stroke in five North Carolina counties observed during two different periods.

We evaluated survival following stroke for patients from a five-county area of rural North Carolina enrolled in either of two community hospital-based stroke survey programs. In this area, the first program enrolled 843 stroke patients between 1970 and 1973 and the second program enrolled 786 stroke patients between 1979 and 1980. One-year survival increased from 49% in the first program to 62% in the second for all stroke patients, from 54% to 68% for patients with cerebral infarction, and from 18% to 55% for patients with cerebral hemorrhage. While other reports have attributed declining stroke mortality to a decline in the incidence of stroke, our study suggests that increased survival after stroke may account for a large portion of the decrease in stroke mortality.

Actuarial Analysis↗
PubMed1989

Increased muscle regeneration after repair of divided motor nerve with neuronotrophic factors containing glue.

Neuronotrophic factors (NTFs) directed to spinal cord motor neurons were collected in rats within silicone nerve regeneration chambers according to LONGO et al. (1983b). Unilateral addition of NTFs to the fibrin glue used for the repair of divided sciatic nerves improved locally nerve regeneration without affecting the controlateral side. Nerve regeneration was assessed by weight gain of the reinnervated muscles and by radioactive labelling of the acid-soluble phosphate fractions of both nerve Schwann cells and reinnervated muscle cells. Fast gastrocnemius and slow soleus muscles, the motor nerve of which had been repaired with added NTFs, were significantly heavier (21 and 28%) than their controlateral controls, and the metabolic dedifferentiation attendant on post-division nerve repair was less marked. It is suggested that this experimental nerve regeneration model is suitable to test potential nerve-active agents in vivo, under conditions close to the usual clinical setting, with, as ultimate goal, the improvement of the end-results of microsurgical repair of peripheral nerve in man.

Animals↗
PubMed1989

Using chromatography in downstream processing.

This article concludes the series on the use of chromatography for downstream processing. Although it has only scratched the surface when considering the number of parameters involved in process chromatography, it does give a broad overview including the choice of components through process standards. Pharmacia LKB Biotechnology has had more than 15 years experience in the design development and running of large scale chromatographic processes. During this time the company has gathered a vast amount of experience and information on the key points to successful product purification. Pharmacia LKB can advise on the choice of techniques and the development of a separation process up to full production scale.

Automation↗
PubMed1988

A blind trial of silicone chamber fluid in nerve regeneration in the rat.

The nerve growth-promoting effects of the fluid accumulating in vivo from 1 to 28 days within silicone chambers were tested on the sciatic nerves of rats. We measured the elongation of sensory axons following nerve transection repaired by means of fibrin sealant allowing local application of the fluid. We found no difference between transections treated with chamber fluid and controls.

Animals↗