PubMed Health⌕ Search

Biomedical subjects

A Roth

Publications and source records attributed to A Roth.

At least 127 records · Page 7Linked to original sources
PubMed1994

The use of intra-aortic balloon pump after surgical treatment of DeBakey type I dissecting aneurysm of the aorta.

The case is reported of a sixty-four-year-old patient with DeBakey type I aortic dissection in whom postoperative extensive intra-aortic balloon pumping was applied. Surgical repair involved replacing the ascending aorta with a Medtronic Hall valved conduit. After surgery severe low-output syndrome occurred. Despite the use of high-dose inotropic drugs the patient could not be hemodynamically stabilized. An intra-aortic balloon pump was finally applied as a therapeutical last resort. Within three days, under counterpulsation, the patient reached a stable hemodynamic condition. After twenty-one days in the intensive care unit, he could be transferred to a normal ward. The patient was discharged on the fifty-fourth postoperative day. During counterpulsation there were no balloon- or catheter-induced complications. Follow-up at five months showed the patient in good general health: echocardiography did not identify any lesions of the thoracic aorta which could be linked to counter-pulsation. It is concluded that the postoperative use of intra-aortic balloon pump in the event of DeBakey type I dissecting aneurysm of the aorta, and adversely affected patient hemodynamics, is a justifiable therapeutical alternative.

Aged↗
PubMed1994

Effect of magnesium on restenosis after percutaneous transluminal coronary angioplasty: a clinical and angiographic evaluation in a randomized patient population. A pilot study. The Ichilov Magnesium Study Group.

Restenosis is a major clinical problem following successful percutaneous transluminal coronary angioplasty. Since magnesium has vasodilator and antithrombotic effects, this study was designed to evaluate its potential to decrease the rate of restenosis. In an open-labelled, randomized controlled study, 148 patients underwent successful coronary angioplasty. Ninety-eight patients were treated with 46-52 mmol/18-20 h intravenous magnesium sulphate (groups M1 and M2), and 49 of them continued with oral supplements of magnesium hydroxide 600 mg.day-1 (group M2). The other 50 patients served as controls (group C). Coronary angiography was performed before, immediately after and at 6 months follow-up or earlier if clinically indicated. Clinical, laboratory, ergometric and radionuclide evaluations were also carried out. One hundred and thirty-nine patients (94%) with 163 dilated segments completed the study. Intravenous magnesium was well tolerated. The cross-sectional area at the site of angioplasty increased by 3.55 +/- 2.01 mm2 in groups M1 and M2 compared with an increase of 2.90 +/- 1.63 mm2 in the control group, (P = 0.03). A trend towards a lower rate of restenosis (> 50% reduction in luminal diameter) was noticed in the magnesium groups (28/110, 25%) compared with the control group (20/53, 38%) P = 0.10. Oral administration of magnesium was well tolerated, did not have an additive effect on restenosis, but an improved clinical course was noted. It is concluded that intravenous administration of magnesium in patients undergoing coronary angioplasty is feasible and safe and that the beneficial trend of magnesium to prevent acute recoil and late (within 6 months) restenosis is encouraging and should promote further investigation in a larger patient population.

Administration, Oral↗
PubMed1994

Vitamin A-soaked gelfoam sponges and wound healing in steroid-treated animals.

Previous work has shown improved wound healing after the administration of systemic vitamin A in patients on chronic steroids. In contrast there have been mixed reports on the effect of topical vitamin A on wound healing in steroid-treated patients. Previous laboratory work has suggested that the topical application of vitamin A may be beneficial to wound healing in a sutured wound in a steroid-treated rat. Due to some inconsistencies in previous studies and steroid animal models, we sought to develop a better wound-healing model in a steroid-treated rat and to assess the effect of topical vitamin A as part of the wound closure. With preliminary studies, we developed a consistent and reliable wound-healing model in a steroid-treated rat using dexamethasone in contrast to cortisone acetate, which had been used in previous studies. Next, rats were randomized into 8 groups, some of which received steroids. Wounds were treated with saline or vitamin A topically or via a soaked gelfoam sponge. Rats were wounded 1 week after the commencement of steroid administration. Wounds were repaired and allowed to heal for 2 weeks. Strips of the wounds were then harvested and tested for tensile strength and breaking strength using a tensiometer. Wound edges were then fixed and wound surface area was measured using digital planimetry. Steroid treatment resulted in consistent weight loss and failure to gain weight as well as decreased breaking strength. Tensile strength was not decreased. Vitamin A applied for 10 minutes before wound closure and a gelfoam sponge alone placed before wound closure both resulted in an increased breaking strength and tensile strength.(ABSTRACT TRUNCATED AT 250 WORDS)

Administration, Topical↗
PubMed1994

Value of PCR for evaluating occurrence of parasitemia in immunocompromised patients with cerebral and extracerebral toxoplasmosis.

PCR was used to evaluate the occurrence of Toxoplasma gondii parasitemia by detection of the B1 gene in blood samples in two groups of immunosuppressed patients (148 subjects) suspected of having cerebral or extracerebral infection, respectively. Group I consisted of 52 patients with AIDS with suspected cerebral toxoplasmosis. The diagnosis was clinically proven in 15 cases. Parasitemia was detected by PCR in only two of these patients (13.3%), both showing evidence of disseminated infection. Group II consisted of 96 immunocompromised patients, either with AIDS or receiving iatrogenic immunosuppressive therapy. Of these patients, 65 (34 with AIDS and 31 others) showed abnormalities only in chest radiography and were first screened for the presence of Toxoplasma DNA in bronchoalveolar lavage fluid. Blood was then analyzed when the parasite was detected in the bronchoalveolar lavage fluid. The remaining 31 subjects (22 with AIDS and 9 others) were suspected of having extracerebral, pulmonary, or disseminated toxoplasmosis, and blood was studied directly in these cases. Among the nine patients with clinically diagnosed extracerebral infection in group II, the parasite was detected by PCR in the blood of five patients (55.5%), all having pulmonary toxoplasmosis. If all patients with clinical manifestations of extracerebral toxoplasmosis (from both groups) who had not received antitoxoplasma therapy when the samples were collected are considered, PCR detected parasitemia in seven of the nine cases (77.8%). The present study indicates that examination of blood by PCR may be valuable in cases of extracerebral toxoplasmosis because of the disseminated nature of the disease. Since most cases of cerebral toxoplasmosis result from the local reactivation of latent brain cysts, detection of parasitemia by PCR is useful only in cases associated with severe cerebral infection or dissemination of this disease.

Acquired Immunodeficiency Syndrome↗
PubMed1994

Ocular rectus muscle insertions revisited: an unusual anatomic approach.

Twenty-five normal adult eyes, taken from fresh human cadavers, were specially prepared in view of the measurements of the arc length of different segments of the globe. The distances measured between the anterior limbus and the scleral insertions of the rectus muscles were similar to those in previous studies with respect to the 'spirale de Tillaux' and a high interindividual variability, i.e. medial rectus 6.2 +/- 0.6 mm, inferior rectus 7.0 +/- 0.6 mm, lateral rectus 7.7 +/- 0.7 mm, superior rectus 8.5 +/- 0.7 mm. The distance between each pair of opposite rectus muscle insertions shows a high interindividual variability (horizontal axis 25.45 +/- 1.38 mm, vertical axis 25.55 +/- 1.45 mm), but the ratio between both distances was always equal to 1 (0.997 +/- 0.031) with a statistically significant correlation (2-tailed p = 0.96). This new approach to rectus muscle insertions may be important for a better understanding of some possible anatomically related factors in strabismus.

Adult↗
PubMed1994

Detection of restenosis following percutaneous coronary angioplasty in single-vessel coronary artery disease: the value of clinical assessment and exercise tolerance testing.

Chest pain and submaximal exercise testing were prospectively assessed over a 6-month period, for detecting the evolution of restenosis in patients undergoing percutaneous coronary angioplasty, following either acute myocardial infarction or treatment of an anginal syndrome. Seventy-eight patients with one-vessel coronary artery disease underwent a modified treadmill exercise test at the 1-week, 3-month and 6-month follow-up after angioplasty, when a final angiogram was also performed. Forty-four patients (group A) were examined after myocardial infarction; in 34 patients (group B) angioplasty was done for incapacitating angina. Both groups showed similar results with low sensitivity and relatively moderate specificity of both chest pain and exercise tests; this was also the case for the time of restenosis to occur. It is thus concluded that the parameters examined are somewhat limited markers of restenosis following coronary angioplasty.

Adult↗
PubMed1994

Percutaneous transluminal coronary angioplasty in elderly patients.

Fifty-six patients aged 75 years and older underwent percutaneous transluminal coronary angioplasty (PTCA) at our institution from 1984 to 1991. The average age was 76.7 +/- 1.5 years, and 84% of the patients were males. Single-vessel disease occurred in 21 patients, double-vessel disease in 16, and three-vessel disease in 19 patients. The mean left ventricular ejection fraction was 57 +/- 5%, and 8 patients had an ejection fraction of < 40%. The anginal functional class was I in 1 patient, II in 3, III in 6, and IV in 46 patients. Single-vessel PTCA was attempted in 43 patients, two-vessel PTCA in 8, and three-vessel PTCA in 5 patients. Revascularization was complete in 35% of the patients, incomplete in 57, and no revascularization was obtained in 8% of the patients. Ninety-one percent of the patients had a successful procedure. In 5 patients there was severe dissection, 1 patient died, 1 patient had an acute myocardial infarction, and 1 patient had emergency bypass surgery. Long-term follow-up (6-96 months, mean 21 +/- 4) in the 51 successfully treated patients revealed late cardiac death in 1 patient, repeated PTCA for restenosis in 9, and coronary bypass surgery in 2 patients. Twenty-two patients were asymptomatic, 12 had improved symptoms, and 5 remained symptomatic. PTCA appears to be a safe and effective treatment in elderly patients with one- and two-vessel disease, with excellent long-term results. Age is not a contraindication to PTCA. The results in elderly patients with three-vessel disease are less encouraging.

Aged↗
PubMed1994

Comparison of the determination of magnesium by methylthymol blue spectrophotometry and atomic absorption spectrophotometry.

Plasma samples (n = 155) of 30 patients on an intensive ward were analysed for magnesium simultaneously by atomic absorption spectrophotometry (AAS) and methylthymol blue spectrophotometry. Methylthymol blue spectrophotometry was performed at the bedside, using two different multianalysers, Easy ST 1 and Easy ST 2, Merck, D-Darmstadt. Precision was 12.2% (Easy ST 1) and 17.1% (Easy ST 2), and the average value was 0.89 mmol/l, which was above the expected range (0.72-0.88 mmol/l). Accuracy was 16.25% (Easy ST 1) and 8.75% (Easy ST 2). Analyser 2 was more accurate (8.75% versus 6.25%) but less precise (17.1% versus 12.2%) than analyser 1. Precision of AAS was between the expected values of 0.69 and 0.84 mmol/l. Easy ST and AAS gave significantly different values (p < 0.0001) for 155 measurements. Comparison of AAS and methylthymol blue spectrophotometery showed that methylthymol blue spectrophotometry produced higher values than AAS (mean difference 0.186 mmol/l). Furthermore, analyses of 40 samples of a standardized plasma concentration with methylthymol blue spectrophotometry showed a very low precision (15.3%). Easy ST cannot be assigned for urinary measurements of magnesium. Experimentally measured samples gave unaccountable results.

Bromthymol Blue↗
PubMed1994

Delirium associated with the combination of a neuroleptic, an SSRI, and benztropine.

BACKGROUND: On the basis of recent findings, the increased use of serotonin selective reuptake inhibitors (SSRIs) in combination with antipsychotics and concomitant benztropine is likely. METHOD: Five patients who developed delirium while receiving a neuroleptic, an SSRI, and benztropine are described. RESULTS: The timing of the delirium in relation to drug administration suggests the delirium was the result of an interaction of the SSRI and benztropine. CONCLUSION: Possible mechanisms are explored. Clinicians should be aware that patients receiving this combination may be at increased risk for delirium.

Aged↗
PubMed1994

A versatile plasmid vector system for the regulated expression of genes in Escherichia coli.

A series of plasmid expression vectors, which support the regulated and efficient expression of genes in Escherichia coli, have been constructed. The vectors consist of a DNA replication origin cassette, a promoter cassette, an efficient ribosome binding site together with a polylinker region and a lacZ gene. Several types of replication origins and promoter sequences are each available on cassettes. Fusion of the 5' TG dinucleotide of the gene under consideration to the A nucleotide, present on the vector, results in an ATG start codon and allows, in combination with the plasmid-borne ribosome binding site, the efficient expression of the cloned gene. Additionally, a second fusion of the gene at its 3' end with the lacZ gene, which is available in all three reading frames relative to the polylinker region, allows rapid selection of the correctly fused genes. As an example of the cloning of a regulatory gene, this vector system was used for the expression of the dnaA gene, of Escherichia coli, the initiator protein for DNA replication.

Bacterial Proteins↗
PubMed1993

Kinetic properties of pure overproduced Bacillus subtilis phenylalanyl-tRNA synthetase do not favour its in vivo inhibition by ochratoxin A.

Ochratoxine A (OTA) inhibits growth of Bacillus subtilis at pHs below 7. Since OTA is a phenylalanine analogue, this effect could be due to inhibition of phenylalanine-tRNA synthetase (PheRS) by competition of this mycotoxin with the amino acid. Homogeneous PheRS was purified from Bacillus subtilis and from E. coli transformed with the PheRS gene. The latter produced about 40 times more PheRS than B. subtilis. The Km and Ki values of PheRS, respectively, for phenylalanine and OTA were measured and their concentrations within the cell determined. It appears that the concentration of OTA in the cell, in spite of a 25-fold accumulation, remained too low to significantly compete with phenylalanine. This does not suggest PheRS to be the target of OTA in cell growth and protein synthesis inhibition in Bacillus subtilis. It was also shown that the 2-3-fold increase of PheRS in OTA-treated cells is not due to phenylalanine-controlled attenuation regulation.

Bacillus subtilis↗
PubMed1993

Regenerative outgrowth and distribution of the electroreceptive nerve fibers in the catfish Kryptopterus.

The ampullary electroreceptors on the trunk of Kryptopterus bicirrhis are induced and continuously maintained by a trophic substance released by their afferent nerve fibers. When the fibers are transected and the proximal stumps deflected to a new place, the regenerating fibers grow along new routes to the old electroreceptor sites and again induce organs there. The new routes consist of two sections. The first goes from the deflected stump end to other nearby running intact or degenerated nerves and fibers. In the second section, the regenerating fibers grow along these nerves and fibers to their distal ends, i.e., to the old electroreceptor sites. If the path-guiding nerves and fibers are experimentally removed, the displaced fibers grow to the normal receptor areas directly. Growing out from the displaced stump, they spread out over the trunk in a pattern similar to the pattern displayed formerly by the original nerve fibers at this place. It is concluded that the outgrowing fibers do not possess a specificity for a certain receptor site or skin area, but spread out according to epigenetic factors in the periphery.

Animals↗
PubMed1993

A randomized comparison between the hemodynamic effects of hydralazine and nitroglycerin alone and in combination at rest and during isometric exercise in patients with chronic mitral regurgitation.

Both arteriolar vasodilation with hydralazine and venodilation with nitroglycerin have been shown to favorably alter the hemodynamic profile in patients with chronic mitral regurgitation. Since these therapeutic modalities exert their effects by different mechanisms, this study was designed to assess hemodynamic response to both drugs given individually and in combination at rest and during isometric exercise in patients with chronic mitral regurgitation of various etiologies. When used individually, hydralazine caused larger increase in heart rate, cardiac index, stroke volume index, and systemic vascular resistance both at rest and during exercise. In contrast, nitroglycerin administration was associated with a superior effect on mean pulmonary artery pressure and V wave amplitude at rest and on mean right atrial and mean pulmonary artery wedge pressures at rest and during isometric exercise. In comparison with hydralazine alone, combination therapy enhanced the reduction in right atrial pressure (4 +/- 1 versus 0 +/- 2 mm Hg, p < 0.05), mean pulmonary arterial pressure (11 +/- 5 versus 1 +/- 3 mm Hg, p < 0.05), and the V wave amplitude (15 +/- 6 versus -5 +/- 3 mm Hg, p < 0.05) at rest and resulted in a larger reduction in exercise values of mean pulmonary artery pressure (-11 +/- 7 versus -3 +/- 5 mm Hg, p < 0.05) and mean pulmonary arterial wedge pressure (-11 +/- 5 versus -5 +/- 3 mm Hg, p < 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1993

Wnt-5a and Wnt-7a are expressed in the developing chick limb bud in a manner suggesting roles in pattern formation along the proximodistal and dorsoventral axes.

The Wnt gene family encodes a group of secreted signalling molecules that have been implicated in the regulation of cell fate and pattern formation during embryogenesis. We have examined the patterns of expression of two members of the chicken Wnt family, Wnt-5a and Wnt-7a, during development of the chick limb bud. Wnt-5a is expressed in the apical ectodermal ridge which directs outgrowth of limb mesoderm. Wnt-5a also exhibits three quantitatively distinct domains of expression along the proximodistal (PD) axis of the limb mesoderm that may correspond to the regions which will give rise to the three distinct PD segments of the limb, the autopod, zeugopod, and stylopod. In contrast, Wnt-7a expression in the limb bud is specifically limited to the dorsal ectoderm. These observations suggest possible roles for Wnt-5a and Wnt-7a in pattern formation along the PD and dorsoventral axes of the developing chick limb bud. In addition, Wnt-5a and Wnt-7a exhibit spatially discrete domains of expression in several other regions of the chick embryo consistent with developmental roles for these genes in a variety of other tissues.

Amino Acid Sequence↗
PubMed1993

Time-consuming procedures and prehospital thrombolytic treatment.

OBJECTIVES: To assess time-consuming procedures in the prehospital stage of acute myocardial infarction patients who had received thrombolytic therapy at the scene, and to evaluate their effect on the clinical outcome. DESIGN: Prospective study. SETTING: Mobile intensive care unit staffed by an intern or a hospital-based physician. PARTICIPANTS AND INTERVENTIONS. Thrombolytic therapy with recombinant tissue-type plasminogen activator (total dose of 120 mg/6 hrs) was initiated at the scene in 167 patients. Treatment continued during transportation and thereafter in the cardiac care unit. During hospitalization, radionuclide ventriculograms and coronary angiography were performed in most patients. MEASUREMENTS AND MAIN RESULTS: Correct diagnosis was confirmed in 165 of 167 patients. Mean time to treatment was 96 +/- 42 (SD) mins with no significant difference between patients treated at home (n = 105) or in public places (n = 60). Global duration of treatment was significantly shorter when thrombolytic therapy was given in public as compared with treatment applied at home (50 +/- 13 vs. 57 +/- 16 mins, respectively, p < .002). CONCLUSION: If patients and physicians become aware of the potential advantages of prompt initiation of thrombolytic therapy at the scene, critical time may be saved in delivering thrombolysis to the clotted coronary artery.

Emergency Medical Services↗
PubMed1993

Rapid resolution of new right bundle branch block in acute anterior myocardial infarction patients after thrombolytic therapy.

The objectives of this retrospective study are to describe the effect of thrombolytic treatment on the clinical course of patients with acute anterior myocardial infarction complicated by acute right bundle branch block. Patients admitted to the intensive cardiac care unit within < 4 hours from onset of symptoms, and demonstrating an acute right bundle branch block with, or without left axis deviation, on the qualifying ECG were included. All were given intravenous thrombolytic treatment consisting of: streptokinase (1,500,000 IU/40 min) or recombinant tissue type plasminogen activator (120 mg/6 hours). Following admission, patients were continuously monitored and a 12-lead ECG was recorded during each of the first 3 hours and then every 3 hours over the next 21 hours. Eight patients were included (8/211 = 3.8%). Their mean age was 62 +/- 7 years and time elapse from onset to treatment was 122 +/- 26 minutes. Complete resolution of the right bundle branch block occurred within < 3 hours in all and left axis deviation normalized in two patients. Mean peak creatine kinase was 1214 +/- 604 IU and global left ventricular ejection fraction, measured by isotope ventriculography within 24 hours from admission, was 39% +/- 15%. Only one patient was prophylactically paced. In the others, rapid normalization of the conduction block with reperfusion exceeded the logistics required for the transvenous pacemaker implantation procedure. Coronary angiography performed in six patients during 72 hours from admission revealed high grade stenoses in the proximal portion of the left anterior descending coronary artery in five patients and complete occlusion in one.(ABSTRACT TRUNCATED AT 250 WORDS)

Bundle-Branch Block↗