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Biomedical subjects

J Rosenthal

Publications and source records attributed to J Rosenthal.

At least 145 records · Page 8Linked to original sources
PubMed1988

Differences in the epidemiology of childhood community-acquired bacterial meningitis between two ethnic populations cohabiting in one geographic area.

A comparison of the epidemiology of community-acquired bacterial meningitis between Jewish and Bedouin populations cohabiting one geographical area is reported here. During the years 1981 to 1985, 100 children younger than 13 years old with community-acquired bacterial meningitis were hospitalized. Seventy-one patients were younger than 12 months. The principal bacteria isolated were Haemophilus influenzae 42%; Streptococcus pneumoniae 29% and Neisseria meningitidis 20%. The case fatality rate was 12%. The chance of acquiring meningitis during the first 5 years of life was twice as common among Bedouins than among Jews (328/100,000 vs. 173/100,000, respectively; P less than 0.0001). The most common cause of meningitis during the first year of life was S. pneumoniae among Bedouins and H. influenzae among Jews. Meningitis caused by H. influenzae and S. pneumoniae was usually associated with respiratory morbidity during fall and winter among Jews, but with diarrheal morbidity during summer and fall among Bedouins. Since the most prevalent type of morbidity among Jews results from respiratory infections and among Bedouins from diarrhea, our findings suggest that community-acquired bacterial meningitis is associated with the type of morbidity most prevalent in the community at any given season rather than with a specific type of infection.

Child↗
PubMed1988

Efficacy of urapidil in the management of essential hypertension. A comparison with captopril.

In a multicentre study by general practitioners, the antihypertensive efficacy of urapidil, a postsynaptic alpha-blocker with central action, was compared with that of the angiotensin-converting enzyme inhibitor captopril. The study was of a double-blind, randomised parallel-group design. Following a 2-week washout and placebo phase, 295 essential hypertensives (WHO I/II) were treated for 12 weeks with either urapidil or captopril, initially with urapidil 60 mg twice daily or captopril 25mg twice daily, with the possibility of adjusting the dose according to blood pressure response after 2 weeks of treatment [diastolic blood pressure (DBP) 90 mm Hg or less: reduction of urapidil to 30 mg twice daily or captopril to 12.5mg twice daily; DBP 91 to 99 mm Hg: dose unchanged; DBP 100 mm Hg or more: dose increased to urapidil 90 mg twice daily or captopril 50 mg twice daily]. Blood pressure values at the end of the 12-week treatment period dropped significantly in the urapidil group (n = 142; all dosages) from 175/103 mm Hg to 154/89 mm Hg (p less than 0.001) and in the captopril group (n = 153; all dosages) blood pressure decreased from 175/103 mm Hg to 154/90 mm Hg (p less than 0.001), corresponding to 62% and 58% urapidil and captopril responder rates (DBP less than or equal to 90 mm Hg), respectively. The responder rate at 12 weeks under urapidil therapy was 30% for the initial, 17% for the lower and 15% for the higher dose; the respective values for captopril were 28, 16 and 14%.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1988

Efficacy of urapidil in the management of essential hypertension: a comparison with captopril.

In a randomized double-blind multicentre study the efficacy (lowering diastolic blood pressure less than or equal to 90 mmHg) of urapidil, a postsynaptic alpha-blocker with central action, was compared with that of the angiotensin converting enzyme inhibitor captopril. Two hundred and ninety-five essential hypertensives (World Health Organization stages I-II; 140 males, 155 females; mean age 51 years) were treated for 12 weeks with either 30-90 mg urapidil twice a day or 12.5-50mg captopril twice a day. Supine blood pressure values (mmHg, means +/- s.d.) at the end of the 12-week treatment period fell in the urapidil group (n = 142) from 175 +/- 19/103 +/- 6 to 154 +/- 17/89 +/- 9 (P less than 0.001), in the captopril group (n = 153) from 175 +/- 19/103 +/- 6 to 154 +/- 19/90 +/- 9 (P less than 0.001), representing responder rates of 62% for urapidil and 58% for captopril. The results demonstrate that two antihypertensive medications with different modes of action control blood pressure with equal efficacy. A dose decrease was possible in 20% of each group, but a dose increase was necessary in 39% of the urapidil and 44% of the captopril group.

Adult↗
PubMed1987

Effect of intrastriatal and intranigral administration of synthetic neuromelanin on the dopaminergic neurotoxicity of MPTP in rodents.

Previous studies showed that the neurotoxin MPTP and its toxic metabolites bind with high affinity to neuromelanin (NM). Therefore, the presence of NM in human and primate but not in rodent substantia nigra, theoretically may be responsible for the species-selective dopaminergic (DA) toxicity of MPTP. We measured DA levels in rodent striatum 7 days after an acute single challenge with MPTP (40 mg/kg, s.c.) given alone or 24 h following unilateral intrastriatal injections of synthetic DA-NM in mice and intrastriatal or intranigral pigment administration in rats. Ipsilateral striatal DA levels were unaffected in control rodents treated with unilateral intrastriatal or intranigral DA-NM. In mice, systemic MPTP produced marked striatal DA depletions which were mildly increased in the striata given prior DA-NM injections. In rats, a species resistant to MPTP, administration of toxin did not affect striatal DA levels. However, after pretreatment with unilateral intrastriatal DA-NM, MPTP induced mild DA falls in ipsilateral striata. By contrast, intranigral administration of DA-NM followed by MPTP, did not alter ipsilateral striatal DA in rats. The findings suggest that intrastriatal DA-NM in mice and rats may augment or initiate, respectively. MPTP-induced damage to sensitive DA-nerve-terminals perhaps by its action as a depot for binding and protracted release and action of the toxin. Lack of effect of intranigral DA-NM which is retained extraneuronally suggests that role of NM in the toxicity of MPTP may depend on its location within DA cell bodies in the nigra.

1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine↗
PubMed1987

The neurotoxin MPTP does not affect striatal superoxide dismutase activity in mice.

Intraneuronal superoxide generation may be a possible mechanism of the dopaminergic (DA) neurotoxicity of MPTP. In such case, MPTP might theoretically affect superoxide dismutase (SOD) activity. We determined SOD activity and DA levels in striata of mice at 0.5, 1, 4, 16, 24 h or 7 days after an acute single injection of MPTP (40 mg/kg, s.c.). MPTP produced marked striatal DA depletions from 4 h post-treatment but SOD activity remained unaltered and similar to controls at all time points. Intrastriatal injections of purified SOD 15 min prior to systemic administration of MPTP did not attenuate the MPTP-induced striatal DA depletions in mice at 7 days post-treatment. Combined administration of MPTP with the SOD inhibitor diethyldithiocarbamate markedly enhanced striatal DA decreases produced by MPTP alone. Findings suggest that MPTP does not act via inhibition of SOD. Therefore, potentiation of MPTP toxicity by diethyldithiocarbamate may be due to interference with other enzymatic systems.

1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine↗
PubMed1987

A multicenter trial of doxazosin in West Germany.

The antihypertensive efficacy and safety of the new long-acting selective alpha 1 inhibitor doxazosin were assessed in patients seen in clinical practice. A total of 232 mild to moderate hypertensive patients were treated by 35 physicians. After an initial 2-week period (phase 1) during which eligibility to enter the study was determined (diastolic blood pressure [BP] of 95 to 114 mm Hg), all patients received doxazosin 1 to 8 mg once daily for 8 weeks (phase 2). Patients were then maintained for another 4 weeks on the dosage necessary to control diastolic BP to less than or equal to 90 mm Hg (phase 3). Efficacy and toleration of doxazosin therapy during the study period were good; 81% of evaluable patients (n = 180) achieved BP control with a once-daily mean dosage of 3.3 mg. At the end of phase 2 BPs were reduced by (systolic/diastolic) 23.8/17.3 (sitting) and 23.7/17.1 mm Hg (standing). Side effects were generally mild to moderate and either were tolerated or disappeared with continued therapy; 7 patients withdrew from the study because of intolerable side effects. Overall results demonstrated that doxazosin is suitable for treatment of mild to moderate hypertension and can be administered on a once-daily basis, which enhances compliance.

Adrenergic alpha-Antagonists↗
PubMed1987

Treatment of advanced bladder carcinoma with irradiation and concomitant 5-fluorouracil infusion.

Nineteen patients with locally advanced bladder cancer were treated with irradiation and concomitant 5-fluorouracil intravenous infusion with or without bolus mitomycin. Eighteen of the 19 patients were evaluated for local response. Eleven of the 18 patients (61%) obtained a complete local response within 3 to 6 months. An additional five patients (28%) showed tumor regression to a superficial state controlled by local transurethral resection and intravesical chemotherapy making the overall local clearance rate 16/18 (89%). The remaining two patients (11%) required salvage cystectomy for persistent disease and presently show no evidence of disease. Nine patients have died. Two patients died of intercurrent disease, six patients died of metastatic disease, and one patient who died from regional disease showed no evidence of local bladder tumor at the time of death. Berkson-Gage life-table analysis yields an adjusted survival of 62.5% at 5 years. Late complications included five patients with hemorrhagic cystitis, two patients with a contracted bladder, and one patient with a hemorrhagic radiation proctitis.

Aged↗
PubMed1987

Clinical variability of partial duplication 1q: a clinical report and literature review.

A female baby with multiple congenital malformations was born to a father previously known as a carrier of reciprocal translocation, t(1;18)(q25;p11). Her chromosome constitution was 46,XX,-18,der18,t(1;18)(q25;p11)pat, namely, partial duplication 1q25----qter. The main manifestations were: macrocephaly, hirsutism, camptodactyly, eye defects, lymphedema, and duodenal atresia. This patient illustrates the phenotype variability expected from such a large duplication of chromosome 1.

Abnormalities, Multiple↗
PubMed1987

Suppression of renin-angiotensin system in the heart of spontaneously hypertensive rats.

Renin-like enzyme and angiotensin converting enzyme (ACE) were identified and their specific activities measured in cardiac tissues of spontaneously hypertensive rats (SHR) and their Wistar-Kyoto (WKY) normotensive controls. In addition, the enzyme activities were determined following administration of hypotensive drugs. The pH optima of cardiac renin-like enzymes were identical with those in vascular walls, the specific activity being higher in the heart. Cardiac ACE revealed similarities with the venous wall enzyme. The highest specific cardiac renin-like activity was found in the septum and that of ACE in atria/auricles. Both enzyme values were lower in the hearts of SHR than in those of normotensive controls. Following nifedipine treatment, specific renin-like activities increased in all cardiac structures studied (P less than 0.01); with nitrendipine and muzolimine less pronounced elevations were obtained. Administration of these three hypotensive drugs resulted in a stimulation of ACE in all the cardiac structures except in atria/auricles, where their activities were lowered.

Animals↗
PubMed1987

Effect of hypotensive agents on the renin-angiotensin system in vascular walls of spontaneously hypertensive rats.

Previous investigations have shown that the renin-angiotensin system (RAS) is activated in vascular walls of spontaneously hypertensive rats (SHR). The present study was undertaken to determine whether antihypertensive drugs attenuate this activation. Two calcium channel blockers, nifedipine and nitrendipine, and the diuretic muzolimine were applied to SHR for 2-4 weeks, and angiotensin (ANG) I-forming angiotensinogenase (AIFA) and ANG I converting enzyme (ACE) activities were determined. The values for both enzymes were elevated in arterial tissues of SHR (P less than 0.01), whereas in venous walls AIFA activity was decreased (P less than 0.01). All hypotensive drugs reduced arterial ACE activities in SHR (nifedipine and muzolimine: P less than 0.01; nitrendipine: P less than 0.05). Angiotensin I-forming angiotensinogenase activity was increased following treatment with nifedipine (P less than 0.01) but reduced by nitrendipine (P less than 0.05); with muzolimine, no significant alterations were observed. The results obtained indicate that in SHR, stimulation of vascular wall ACE is abolished following treatment with hypotensive agents, and the effect is independent of their mode of action. It is assumed that the activation of vascular ACE is not caused by, but rather a reaction to, elevated blood pressure.

Animals↗
PubMed1987

Aging and the cardiovascular system.

As a result of aging, a variety of structural and biochemical changes occur in arterial walls that result in hemodynamic adaptations. With age, there is a thickening of intima and media, together with an increase in the number of smooth muscle cells, synthesis of collagen and elastin, and deposition of calcium, glycosaminoglycans, free and esterified cholesterol, and sphingolipids. These changes are similar to those observed in atherosclerosis, which is accompanied by marked increases of intimal smooth muscle cells and connective tissue constituents. The net effects of both aging and atherosclerosis are a loss of elasticity and distensibility. This results in a decrease in arterial compliance or capacitance, which in turn means that with increasing age systolic blood pressure (SBP) tends to be higher, and diastolic blood pressure (DBP) lower. As a consequence of structural changes both in myocardium and vessels, cardiac output and renal and hepatic blood flow undergo adaptive alterations in order to meet the requirements of central hemodynamics and peripheral circulation. The implications of these processes of aging demand appropriate treatment of cardiovascular disorders, in particular hypertension, which occurs in 30-50% of patients above the age of 60 years. Appropriate treatment may demand dose adjustment and careful selection of antihypertensive drugs with a minimum of side effects, which additionally are capable of diminishing preload and afterload.

Aging↗
PubMed1986

Effect of serotonergic, corticostriatal and kainic acid lesions on the dopaminergic neurotoxicity of 1-methyl-4-phenyl-1,2,5,6-tetrahydropyridine (MPTP) in mice.

In mice, prior destruction of striatal 5-hydroxytryptamine (5-HT) neurons by intrastriatal or intraventricular injections of 5,7-dihydroxytryptamine did not abolish or attenuate DA depletions produced in striatum by 1-methyl-4-phenyl-1,2,5,6-tetrahydropyridine (MPTP). This suggests that although they contain monoamine oxidase type B, the oxidative conversion of MPTP to 1-methyl-4-phenyl-pyridinium ion (MPP+) does not take place in 5-HT neurons. Likewise, decortication and kainic acid lesions did not prevent or enhance striatal MPTP-induced DA decrements suggesting that corticostriatal projections and striatal neurons are not involved in the mechanisms of MPTP neurotoxicity.

1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine↗