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Biomedical subjects

S Weber

Publications and source records attributed to S Weber.

At least 271 records · Page 15Linked to original sources
PubMed1988

[A study using the computer-controlled perimeter Perimat 206 on the effect of Circo-Maren on visual field defects].

In 1987 an open study was conducted in an ophthalmological practice to test Circo-Maren tablets. Examinations using a computerized perimeter revealed that therapy with Circo-Maren can lead to a reduction in visual field defects in patients with senile macular edema and retinal angiosclerosis. In cases with severe defects, favorable results were achieved which were statistically significant (duration of treatment: 4-12 weeks). Considerable fluctuations in the number and intensity of the defects were seen in the various intermediate examinations.

Aged↗
PubMed1988

Direct comparison of electric field-mediated and PEG-mediated cell fusion for the generation of antibody producing hybridomas.

As an alternative to polyethylene glycol (PEG), electric field pulses offer, in theory, fusion conditions whose parameters are better controllable. In 1985 (1) we reported on the successful generation of hybridoma clones by means of electrofusion performed in a batch-type manner similar to that usually employed with PEG, and applicable to any type of antigens. Here we summarize the results of a series of fusions performed since then in which both electric field and PEG induced fusion were directly compared. Different types of antigens were used. Electrofusion resulted in a 3.8 to 33.0 times higher yield of hybridomas per unit number of spleen cells. Moreover, hybridomas grew more vigorously after fusion and, therefore, were earlier visible. Other parameters examined revealed no differences between hybridomas generated by either method.

Animals↗
PubMed1988

Mivacurium chloride (BW B1090U)-induced neuromuscular blockade during nitrous oxide-isoflurane and nitrous oxide-narcotic anesthesia in adult surgical patients.

The neuromuscular and cardiovascular effects of mivacurium were studied in 90 adult patients during nitrous oxide-oxygen-isoflurane (n = 45, ISO group) and nitrous oxide-oxygen-narcotic (n = 45, BAL group) anesthesia. Neuromuscular blockade was measured using electromyographic activity of the adductor pollicis muscle after supramaximal stimulation of the ulnar nerve at 2 Hz for 2 seconds at 10-second intervals. To estimate dose-response relations, three subgroups of nine patients in the ISO group received mivacurium doses of 0.025, 0.03, and 0.04 mg/kg, respectively. Similarly, three subgroups of nine patients in the BAL group received mivacurium doses of 0.03, 0.04, and 0.05 mg/kg, respectively. The ED50 and ED95 of mivacurium in each group were estimated from linear regression plots of log dose vs probit of maximum percentage depression of neuromuscular function. The estimated ED50 values for the ISO and BAL groups were 0.029 and 0.041 mg/kg, respectively. The estimated ED95 values for the ISO and BAL groups were 0.045 and 0.058 mg/kg, respectively. Recovery indexes were measured in 26 patients who received ED95 or greater doses of mivacurium in either the ISO or BAL groups. The recovery index was shorter in the BAL group (5.5 +/- 1.6 minutes [n = 10]), than in the ISO group (7.4 +/- 3.0 minutes [n = 16]). The addition of isoflurane (0.5-0.75% end-tidal concentration) to nitrous oxide-narcotic anesthesia augments the degree of neuromuscular blockade from a given dose of mivacurium and also prolongs the recovery index.

Adult↗
PubMed1988

[Myocardial microvascularization in scleroderma].

Myocardial involvement in systemic sclerosis may be caused, at least in part, by myocardial ischemia due to functional or structural abnormalities of small coronary arteries or arterioles. Coronary reserve, assessed by dipyridamole-induced coronary vasodilatation, was strikingly impaired in patients with systemic sclerosis. Thallium scans have shown numerous myocardial perfusion defects in scleroderma patients. Two studies, using oral nifedipine and intravenous dipyridamole, demonstrated that these thallium-201 myocardial perfusion defects in patients with systemic sclerosis were partially reversible. Finally, the preliminary results of long-term studies suggest that some coronary vasodilators may be beneficial in the long-term treatment of myocardial perfusion abnormalities in systemic sclerosis.

Coronary Circulation↗
PubMed1988

Nicardipine improves myocardial perfusion in systemic sclerosis.

Primary scleroderma myocardial disease may be due in part to myocardial ischemia caused by a disturbance of the coronary microcirculation. We evaluated the effect of the calcium channel blocker nicardipine on myocardial perfusion assessed by thallium-201 scanning in 16 patients with systemic sclerosis. Thallium-201 single photon emission computerized tomography was performed at baseline and 90 min after 40 mg of oral nicardipine. The mean (+/- SD) number of left ventricular segments with perfusion defects significantly decreased from 6.0 +/- 2.0 at baseline to 4.1 +/- 2.3 after nicardipine (p less than 0.01). The mean global perfusion score significantly increased from 10.2 +/- 1.9 at baseline to 11.9 +/- 2.6 after nicardipine (p less than 0.02). Our study demonstrates short-term improvement in thallium-201 myocardial perfusion with nicardipine in patients with systemic sclerosis.

Adult↗
PubMed1988

Comparison of sleep staging by polygraph and color density spectral array.

Color Density Spectral Array (CDSA) is a new technique that uses the fast Fourier transform and color graphics to provide a display of frequency, power, and time. CDSA sleep records provide an overview of sleep architecture as well as quantitative+ EEG data. To validate this technique, overnight sleep records from five patients were independently staged from polygraph recordings and overnight CDSA records. Observed agreement between the two techniques was 85-92% for approximately 1,100 epochs per night.

Adult↗
PubMed1987

Monitoring technique affects measurement of recovery from succinylcholine.

To compare recovery time from neuromuscular blockade after the administration of a single intravenous bolus of succinylcholine (1 mg/kg), we measured, both mechanically and electromyographically, the evoked twitch responses in the hand muscles of 10 patients. Electromyographic data were obtained, electronically integrated, and recorded by a newly available clinical monitoring device. Using both the mechanical and the electromyographic devices, we recorded the times for first return of twitch, as well as for 25% and 75% recovery of twitch height compared with prerelaxant twitch baseline values and compared the values by calculating least-squares regression lines. Times given by the electromyographic device for these measures of returning neuromuscular function were notably longer than those given by the mechanical evoked force monitor. No such findings have been reported in previous studies that compared these two techniques for monitoring of muscle recovery from nondepolarizing relaxants. The specific reasons for the differences found in this study are unknown.

Adult↗
PubMed1987

Transurethral prostatectomy complicated by intraperitoneal extravasation of irrigating fluid.

A patient underwent transurethral resection of the prostate (TURP), which was complicated at the outset of the procedure by an inadvertent puncture wound of the dome of the bladder and the peritoneum. Shortly after resection was initiated, the patient developed shoulder pain and a tensely distended abdomen, although at this time the serum sodium concentration remained normal. Over the next several hours the patient developed significant hyponatremia. The prolonged and gradual time course of this development suggests that fluid and electrolyte shifts occurred via diffusion across the peritoneal membrane. This case illustrates a rare but potentially dangerous complication of TURP that requires recognition prior to initiation of appropriate therapy.

Extravasation of Diagnostic and Therapeutic Materi↗
PubMed1987

The brown colour effect (BCE) of Cryptococcus neoformans in the diagnosis, control and epidemiology of C. neoformans infections in AIDS patients.

Cryptococcus neoformans was found as the causative agent of cryptococcosis in 7 (3.6%) out of 195 HIV-positive persons, most of them being hospitalized. These 7 persons included 6 homosexuals and 1 heroin addict. The examinations were performed at the Mycology Unit of the Robert Koch Institute in Berlin (West) between 1984 and 1986. The brown colour effect (BCE) of the C. neoformans colonies on Guizotia abyssinica creatinine agar (with 0.1% glucose) within 2-5 days at 26 degrees C facilitated the diagnosis of disseminated cryptococcosis. In all 7 cryptococcosis cases, the antigen of C. neoformans was detected in serum and CSF by the latex agglutination test. The initial titres ranged from 1:100,000 to 1:160 in the serum and from 1:1280 to 1:10 in the CSF. In comparison to the progressive stage of the infection with the involvement of the various organs and high antigen titres, the fungus may be detected at an early stage in the respiratory tract only where low antigen titres are observed. All the C. neoformans isolates were found to belong to the variety neoformans. Proposals for an effective control of cryptococcosis are made.

Acquired Immunodeficiency Syndrome↗
PubMed1987

[Effects of compression stockings on blood circulation in late pregnancy].

The effect of Class II compression stockings on maternal and fetal circulation was studied in left lateral position and standing in 21 patients with uterovascular syndrome in late pregnancy. The effect of different compression pressures was analyzed in further seven women also suffering from uterovascular syndrome in late pregnancy. It was shown that the use of compression stockings causes a measurable improvement in maternal and fetal circulation. The most favourable compression pressure for the maternal circulation parameters measured is 40 mm Hg.

Adaptation, Physiological↗
PubMed1987

The RAD3 gene of Saccharomyces cerevisiae encodes a DNA-dependent ATPase.

The RAD3 gene of the yeast Saccharomyces cerevisiae is required for excision repair of damaged DNA and for cell viability. A protein of approximately equal to 89 kDa was purified to near homogeneity from yeast strains harboring multicopy plasmids that overproduce RAD3 protein; this protein corresponds closely to the expected size of the RAD3 protein and cross-reacts with the antiserum raised against a truncated RAD3 protein produced in Escherichia coli. The purified RAD3 protein shows a single-stranded DNA-dependent ATPase activity that catalyzes hydrolysis of ATP to ADP and Pi. The ATPase activity was coincident with the RAD3 protein during purification and is inhibited by anti-RAD3 antibodies, indicating that the RAD3 gene encodes this activity.

Adenosine Triphosphatases↗
PubMed1987

Effects of isoproterenol-induced tachycardia on myocardial blood flow and glycogen in the fetal lamb.

In utero tachycardia is a cause of fetal congestive heart failure and fetal hydrops. We investigated the effects of isoproterenol-induced tachycardia (IIT) on cardiac output and its distribution, on myocardial blood flow and intramyocardial blood flow distribution as well as on regional myocardial glycogen in 8 chronically prepared, near-term fetal lambs and 3 control twins (for myocardial glycogen only). Blood flows were measured by the radioactive microsphere method, myocardial glycogen by an enzymatic method. In animals with IIT (heart rate 200-280), cardiac output (excluding lung flow) increased from 0.399 to 0.544 ml/g/tissue/min (+36%), blood flow to the carcass increased from 0.19 to 0.32 ml/g/tissue/min (+68%) and myocardium increased from 2.31 to 7.72 ml/g/tissue/min (+234%), while kidney blood flow decreased from 1.34 to 0.72 ml/g/tissue/min (-46%). The normal intramyocardial blood flow distribution and predominance of flow to the endocardium of both ventricles was preserved during IIT. In the three sets of twins, glycogen was lower in the right (RV) and left (LV) ventricular walls of each animal stressed by IIT (mean RV = 0.19, mean LV = 0.44) than of its unstressed twin (mean RV = 0.75, mean LV = 0.70). Furthermore, a metabolic acidemia (mean pH 7.21, mean BE -8.4) developed in the stressed animals. Although we were unable to demonstrate regional myocardial ischemia at the maximal fetal heart rates achieved by isoproterenol infusion, our data suggest that metabolic acidemia and myocardial glycogen depletion are consequences of severe inotropic and chronotropic stress in the fetal lamb.

Animals↗
PubMed1987

Nicardipine in the treatment of Raynaud's phenomenon: a randomized double-blind trial.

The efficacy of the calcium-channel blocker nicardipine in the treatment of Raynaud's phenomenon was assessed in a prospective, double-blind, randomized, crossover trial in 20 patients. Each patient received nicardipine 20 mg or placebo three times a day for two weeks and then was crossed over for two weeks. Nicardipine significantly decreased the frequency and severity of Raynaud's phenomenon as compared with placebo. The authors conclude that nicardipine is effective in the treatment of Raynaud's phenomenon.

Adolescent↗