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Biomedical subjects

J Kalman

Publications and source records attributed to J Kalman.

At least 19 recordsLinked to original sources
PubMed2006

Comparing sediment quality in Spanish littoral areas affected by acute (Prestige, 2002) and chronic (Bay of Algeciras) oil spills.

The quality of sediments collected from two areas of the Spanish coast affected by different sources of contaminants has been compared in this study. The areas studied are the coast of Galicia affected by the oil spill from the tanker Prestige (November 2002) and the Gulf of Cádiz which suffers continuous inputs of contaminants from industries located in the area and from oil spills. Contamination by several chemicals (metals, PCBs and PAHs) that bind to sediments was analyzed, and two toxicity tests (Microtox) and amphipod 10-day bioassay) were conducted. PAHs were identified as the compounds responsible for the toxic effects. Results show differences between an acute impact related to the sinking of the tanker Prestige and the chronic impact associated with continuous oil spills associated with the maritime and industrial activities in the Bay of Algeciras, this being the most polluted part of the two coastal areas studied in this work.

Amphipoda↗
PubMed2000

Full and fractionated experimental designs for robustness testing in the high-performance liquid chromatographic analysis of codeine phosphate, pseudoephedrine hydrochloride and chlorpheniramine maleate in a pharmaceutical preparation.

This paper describes the testing of a saturated factorial design using a full factorial design. Saturated factorial designs are often used to test the robustness of high-performance liquid chromatography (HPLC) methods, however they are based on several assumptions. A full factorial design relies on fewer assumptions and hence could be used to evaluate the effectiveness of the saturated design. Both designs were used to test a gradient HPLC method for the assay of codeine phosphate, pseudoephedrine hydrochloride and chlorpheniramine maleate. Six HPLC conditions, including wavelength, mobile phase pH and ion pairing reagent concentration were tested using the saturated design. Three of these factors were selected for full evaluation using a full factorial design. The results showed that the main effects calculated by each design were comparable. However, the saturated design showed higher standard errors, probably due to the effects of changing several more factors. One interaction effect was indicated as a confounding effect by the saturated design and this was confirmed by the calculation of the same interaction effect using the full design. Overall the method was shown to be robust under the variety of HPLC conditions tested.

Chlorpheniramine↗
PubMed2000

Hemodynamic comparison of twice daily metoprolol tartrate with once daily metoprolol succinate in congestive heart failure.

OBJECTIVES: To compare the hemodynamic effects of twice daily metoprolol tartrate (MT) and once daily metoprolol succinate (MS) in congestive heart failure patients. BACKGROUND: Adverse hemodynamic effects with MT demonstrated during initiation persist with drug readministration during chronic therapy. METHODS: Patients were randomly assigned to 6.25 mg MT or 25 mg MS orally and the dose was gradually increased to a target of 50 mg twice a day or 100 mg once a day, respectively. Hemodynamic measurements were obtained at baseline and after three months of therapy--both before and after drug readministration. RESULTS: Long term metoprolol therapy produced significant functional, exercise and hemodynamic benefits with no difference in response between either metoprolol preparation in the 27 patients (MT [14], MS [13]). When full dose metoprolol was readministered during chronic therapy, there were parallel adverse hemodynamic effects in both drug groups. Cardiac index decreased by 0.6 liters/min/m2 (p < 0.0001) with MT and by 0.5 liters/min/m2 (p < 0.0001) with MS. Systematic vascular resistance increased by 253 dyne-sec-cm(-5) (p < 0.001) with MT and by 267 dyne-sec-cm(-5) (p < 0.0005) with MS. Stroke volume index decreased by 7.0 ml/m2 (p < 0.0005) with MT and by 6.5 ml/m2 (p < 0.0001) with MS, while SWI decreased by 6.2 g-m/m2 (p < 0.0005) with MT and by 6.0 g-m/m2 (p < 0.001) with MS. CONCLUSION: Metoprolol tartrate and MS produce similar hemodynamic and clinical effects acutely and chronically despite the fourfold greater starting dose of MS used in this study. A more rapid initiation with readily available starting doses of MS may offer distinct advantages compared with MT in treating chronic heart failure patients with beta-adrenergic blocking agents.

Administration, Oral↗
PubMed2000

Apolipoprotein D in the aging brain and in Alzheimer's dementia.

Apolipoprotein D (apoD) levels were examined in the temporal cortex as well as an assessment of the location of apoD positive cells within the brain by immunohistochemical and biochemical methods in young control (YC), aged control (AC), and Alzheimer's demented (AD) probands. Scattered apoD positive astrocytes and oligodendrocytes were found throughout the white matter by immunohistochemistry. ApoD immunoreactivity was also observed in the cerebellar oligodendrocytes of the YC group. There was faint positive apoD staining in scattered cortical astrocytes and a few neurons in the same group. In contrast, some of the AC and all of the AD probands had intense and frequent apoD immunostained cortical astrocytes and pyramidal neurons. The cortical senile plaques and neurofibrillary tangles were apoD immunonegative. No quantitative differences were found between the cortical apoD levels in the AC and AD groups, determined by immunoblotting. ApoD detected in the brain tissue was different in molecular weight (29 kDal) from that seen in CSF or in the serum (32 kDal). Our results indicate apoD is present in the human brain, especially in glial cells, and has increased abundance in the elderly and AD subjects.

Adult↗
PubMed1999

Prospective, randomized comparison of effect of long-term treatment with metoprolol or carvedilol on symptoms, exercise, ejection fraction, and oxidative stress in heart failure.

BACKGROUND: With beta-blocker use becoming more prevalent in treating chronic heart failure (CHF), the choice of drugs raises important theoretical and practical questions. Although the second-generation compound metoprolol is beta1-selective, the third-generation compound carvedilol is beta-nonselective, with ancillary pharmacological properties including alpha-blockade and antioxidant effects. A prospective comparison of these 2 agents can address the issue of optimal adrenergic blockade in selecting agents for therapy in CHF. METHODS AND RESULTS: Sixty-seven patients with symptomatic stable heart failure were randomly assigned to receive either carvedilol or metoprolol in addition to standard therapy for CHF. Measured variables included symptoms, exercise, ejection fraction, and thiobarbituric acid-reactive substances (TBARS) as an indirect marker of free radical activity. Metoprolol and carvedilol were well tolerated, and both patient groups showed beneficial effects of beta-blocker therapy in each of the measured parameters, with no between-group differences. Ejection fraction increased over 6 months from 18+/-6.3% to 23+/-8.7% (P<0.005) with metoprolol and from 19+/-8.5% to 25+/-9.9% (P<0.0005) with carvedilol (P=NS between groups). With metoprolol, TBARS values decreased from 4.7+/-0.9 nmol/mL at baseline to 4.2+/-1.5 nmol/mL at month 4 to 3.9+/-1.0 nmol/mL at month 6 (P<0.0001). With carvedilol, there was a parallel decline from 4.7+/-1.4 to 4.2+/-1.3 to 4.1+/-1.2 nmol/mL over the same time frame (P<0.025), with no between-group difference in these changes. CONCLUSIONS: Carvedilol and metoprolol showed parallel beneficial effects in the measured parameters over 6 months, with no relevant between-group differences in this heart failure population.

Adrenergic beta-Antagonists↗
PubMed1999

Short-term and long-term hemodynamic and clinical effects of metoprolol alone and combined with amlodipine in patients with chronic heart failure.

BACKGROUND: Initiation of beta-blocker therapy is often limited by worsening congestive heart failure, which may manifest as worsening hemodynamics. Deleterious hemodynamic effects might be mitigated with the vasodilation of combined calcium channel/beta-blocker therapy. METHODS AND RESULTS: This prospective, randomized study assessed the safety and efficacy of metoprolol alone or combined with amlodipine on hemodynamic parameters at baseline, 2 hours after the first dose of study medication, and after 12 weeks of therapy in patients receiving background triple therapy for mild to severe heart failure. Functional, exercise, and hormonal status were assessed at baseline and end of study. Twenty-nine patients (mean age 50 +/- 12.1 years) were enrolled; 21 completed 12 weeks of treatment. Mean ejection fraction at baseline was 13.4% +/- 5.7%; 79% of patients had heart failure classified as New York Heart Association class III, and 66% had heart failure of idiopathic origin. Heart rate and blood pressure did not change with short-term therapy in either group. The first dose of both regimens produced significant increases in systemic vascular resistance and significant decreases in cardiac output and index and stroke volume and stroke work indexes; combination therapy acutely yielded small but statistically significant increases in pulmonary artery, pulmonary capillary wedge, and right atrial pressures. Long-term therapy with both regimens produced significant decreases in heart rate, systemic vascular resistance, and pulmonary capillary wedge pressure and significant increases in cardiac output and index and stroke volume and stroke work indexes. Combination therapy produced significant long-term decreases in blood pressure. CONCLUSIONS: There was no further measurable benefit with the addition of amlodipine to metoprolol compared with the effects of metoprolol alone. Therapy with metoprolol alone and the combination of metoprolol and amlodipine was well tolerated in patients with mild to severe heart failure, as evidenced by a lack of adverse effects on hemodynamic parameters over the short term and clinical and hemodynamic improvement with long-term treatment.

Adrenergic beta-Antagonists↗
PubMed1999

Doppler pulse waveform analysis of carotid and middle cerebral artery flow in a patient with an intra-aortic balloon pump.

A 60-year-old man with intractable congestive heart failure (CHF) had an intra-aortic balloon pump placed to augment coronary artery perfusion. During the evaluation prior to heart transplant, carotid and transcranial Doppler ultrasonography (TCD) was performed. The authors report the findings of Doppler waveform analysis and the presence of balloon pump artifact which caused difficulty in distinguishing between internal and external carotid arteries. Higher blood flow velocity during diastole and diastolic runoff characteristically seen while insonating the internal carotid artery enabled that distinction.

Artifacts↗
PubMed1998

Contrasting child and adolescent psychiatry services in Szeged, Hungary, and Glasgow, Scotland.

International comparisons of child and adolescent psychiatry services are rarely reported in the literature. The present study arose out of a TEMPUS collaborative project between the University Departments of Child and Adolescent Psychiatry in Szeged, Hungary, and Glasgow, Scotland. Using the Glasgow Audit Questionnaire, a profile of each service was obtained, including basic demographic data, types of disorders referred, treatment modalities used, and a measure of outcome. The results of this descriptive study indicate that although the two centres were broadly similar, there were major differences in the treatment modalities used. Reasons for the findings are discussed, as are the limitations of the study.

Adolescent↗
PubMed1997

A placebo-controlled trial verifying the efficacy of milrinone in weaning high-risk patients from cardiopulmonary bypass.

OBJECTIVE: To establish the efficacy of the phosphodiesterase inhibitor milrinone in facilitating weaning from cardiopulmonary bypass of high-risk patients with left ventricular dysfunction and/or pulmonary hypertension. DESIGN: A double-blinded, placebo-controlled longitudinal study. SETTING: A university teaching hospital. PARTICIPANTS: Thirty-two patients with preoperative left ventricular ejection fraction < or = 35% and/or mean pulmonary artery pressure > or = 20 mmHg were studied after their written informed consent. INTERVENTION: Patients were randomized to commence either intravenous milrinone, 50 micrograms/kg loading dose over 20 minutes followed by 0.5 microgram/kg/min infusion, or matching placebo 15 minutes before withdrawal of cardiopulmonary bypass. MEASUREMENTS AND MAIN RESULTS: Two patients were withdrawn from the study and their results not analyzed: one because of early failure of hemodynamic monitoring and the other because of gross surgical bleeding. In the remaining 30 patients, who were well matched for clinical and baseline hemodynamic variables, bypass support was successfully withdrawn in all 15 patients randomized to receive milrinone but in only 5 of the 15 patients randomized to receive placebo. In the 10 patients who initially failed to wean from bypass while on placebo, bypass was reinstituted and open-label milrinone was administered in the dose outlined. After treatment with open-label milrinone, these patients could also be withdrawn from bypass support. During the period of hemodynamic monitoring, cardiac index increased in both milrinone- and placebo-treated patients, although this change was greater in those treated with milrinone. Perhaps related to routine clinical treatment, there were no significant differences between the two groups with mean pulmonary artery or pulmonary capillary wedge pressures, the other major hemodynamic endpoints. There were no significant adverse effects related to milrinone. CONCLUSIONS: This placebo-controlled, double-blind study has conclusively demonstrated the benefits of milrinone in facilitating weaning of high-risk patients from cardiopulmonary bypass.

Aged↗
PubMed1997

Beta blockade in congestive heart failure: persistent adverse haemodynamic effects during chronic treatment with subsequent doses.

OBJECTIVE: To determine whether the acute adverse haemodynamic effects of beta blockade in patients with congestive heart failure persist during chronic treatment. DESIGN: Sequential haemodynamic evaluation of heart failure patients at baseline and after three months of continuous treatment with the beta 1 selective antagonist metoprolol. SETTING: Cardiac care unit in university hospital. PATIENTS: 26 patients with moderate to severe congestive heart failure (New York Heart Association grade II to IV) and background treatment with digoxin, diuretics, and angiotensin converting enzyme inhibitors, and with a left ventricular ejection fraction < 25%. METHODS: Baseline variables included a six minute walk, maximum oxygen consumption, and right heart catheterisation. All patients received metoprolol 6.25 mg orally twice daily initially and the dose was gradually increased to a target of 50 mg twice daily. Haemodynamic measurements were repeated after three months of treatment, both before (trough) and after drug readministration. RESULTS: Long term metoprolol had functional, exercise, and haemodynamic benefits. It produced decreases in heart rate, pulmonary capillary wedge pressure, and systemic vascular resistance, and increases in cardiac index, stroke volume index, and stroke work index. However, when full dose metoprolol was readministered during chronic treatment, there was a reduction in cardiac index (from 2.8 (SD 0.46) to 2.3 (0.38) l/min/m2, p << 0.001) and stroke work index (from 31.4 (11.1) to 26.6 (10.0) g.m/m2, p < 0.001) and an increase in systemic vascular resistance (from 943 (192) to 1160 (219) dyn.s.cm-5, p << 0.001). CONCLUSIONS: Adverse haemodynamic effects of beta blockers in heart failure persist during chronic treatment, as shown by worsening haemodynamic indices with subsequent doses.

Adrenergic beta-Antagonists↗
PubMed1996

Combined alpha-beta blockade (doxazosin plus metoprolol) compared with beta blockade alone in chronic congestive heart failure.

There has been growing evidence for the benefits of beta blockers, but alpha blockers have not shown sustained benefits in chronic congestive heart failure (CHF). Thirty patients with moderate to severe CHF (New York Heart Association class II to IV) were sequentially assigned to receive metoprolol 6.25 mg with the alpha-1 antagonist doxazosin 4 mg/day or metoprolol alone. The dose of metoprolol was gradually increased to a target dose of 50 mg orally twice daily. Hemodynamic measurements were obtained before drug therapy, 2 hours after the first dose of combined alpha-beta therapy or metoprolol alone, and after 3 months of continuous treatment. Nuclear ejection fraction, plasma norepinephrine, and submaximal and maximal exercise capacity were also measured before and after chronic therapy. With initial combined drug administration, mean arterial pressure, left ventricular filling pressure, and systemic vascular resistance decreased significantly compared with results after metoprolol alone. However, after 3 months of continuous therapy, both treatment groups showed similar and significant reductions in systemic vascular resistance and heart rate, with significant increases in cardiac index, stroke volume index, stroke work index, ejection fraction, and exercise capacity. Furthermore, the next dose of chronic combined medication no longer showed vasodilating effects. Chronic therapy with fixed-dose doxazosin and increasing doses of metoprolol produced identical effects as those seen in patients receiving metoprolol alone.

Adrenergic alpha-Antagonists↗
PubMed1993

Radiofrequency catheter ablation of tachyarrhythmias--adult and paediatric experience.

BACKGROUND AND AIMS: Until recently, curative therapy for supraventricular tachycardia (SVT) was possible only with map-guided cardiac surgery. The ability to ablate permanently the reentrant circuit responsible for tachycardia using radiofrequency electrical current (RF) delivered through a catheter has now allowed cure of SVT by non-surgical means. We present our initial experience with this technique in both adult and paediatric patients. METHODS: In 53 patients of median age 32 years, 56 radiofrequency catheter ablation procedures were performed for control of tachyarrhythmias. Fourteen patients were aged 18 years or less. Indications for RF ablation were SVT due to an accessory pathway (n = 27), SVT due to atrioventricular junctional reentry (AVJRT) (n = 22), incessant SVT (n = 2), ventricular tachycardia (n = 2), and uncontrolled atrial fibrillation (n = 3). General anaesthesia was used in 88% of procedures. Ablation was preceded by electrophysiological testing to confirm tachycardia mechanism in all cases. RESULTS: The ablation procedure was completely successful in 49/56 cases (87.5%) and partially successful in another two cases. Only five procedures (9%) failed. Median procedure time was two hours, median fluoroscopy time was 24 min, and the median number of RF applications was four. There were no major differences in results comparing adult and paediatric patients. A transient ulnar nerve palsy was the only major complication observed. After a follow-up of one to 15 months, tachycardia has recurred in two patients (4%). Of the total 53 patients, 90.5% are currently asymptomatic and off all cardiac drug therapy. RF catheter ablation appears to be an effective, curative, and relatively safe alternative to long term drug therapy in the management of troublesome SVT.

Adolescent↗
PubMed1991

Elevated circulating tumor necrosis factor levels in Alzheimer's disease.

Recent investigations have demonstrated a local inflammatory response in Alzheimer's disease (AD), including microglia and cytokines. Levels of the cytokine tumor necrosis factor alpha (TNF-alpha) in sera from patients with AD and age-matched controls were measured by an enzyme-linked immunoassay and a cytotoxicity bioassay. Significantly elevated levels of TNF were found in AD sera compared to controls. Elevated circulating TNF may be derived from the local CNS inflammatory reaction in AD, and may account for some systemic manifestations of AD such as weight loss. Future studies may determine if, in the absence of complicating disorders which may elevate TNF, circulating TNF could be a marker of AD inflammatory activity.

Aged↗
PubMed1990

Elevated circulating levels of tumor necrosis factor in severe chronic heart failure.

BACKGROUND AND METHODS: Although cachexia often accompanies advanced heart failure, little is known about the causes of the cachectic state. To assess the potential role of tumor necrosis factor in the pathogenesis of cardiac cachexia, we measured serum levels of the factor in 33 patients with chronic heart failure, 33 age-matched healthy controls, and 9 patients with chronic renal failure. RESULTS: Mean (+/- SEM) serum levels of tumor necrosis factor were higher in the patients with heart failure (115 +/- 25 U per milliliter) than in the healthy controls (9 +/- 3 U per milliliter; P less than 0.001). Nineteen of the patients with chronic heart failure had serum levels of tumor necrosis factor greater than or equal to 39 U per milliliter (greater than 2 SD above the mean value for the control group), whereas the remaining 14 patients had serum levels of tumor necrosis factor below this level. The patients with high levels of tumor necrosis factor were more cachectic than those with low levels (82 +/- 3 vs. 95 +/- 6 percent of ideal body weight, respectively; P less than 0.05) and had more advanced heart failure, as evidenced by their higher values for plasma renin activity (2.92 +/- 0.53 vs. 1.06 +/- 0.53 ng per liter per second [10.5 +/- 1.9 vs. 3.8 +/- 1.9 ng per milliliter per hour]; P less than 0.01) and lower serum sodium concentration (135 +/- 1 vs. 138 +/- 1 mmol per liter; P less than 0.05). The group with high levels of tumor necrosis factor also had lower hemoglobin levels (7.82 +/- 0.2 vs. 8.69 +/- 0.4 mmol per liter [12.6 +/- 0.4 vs. 14.0 +/- 0.6 g per deciliter]) and higher values for blood urea nitrogen (19.5 +/- 2.2 vs. 12.5 +/- 1.8 mmol per liter) than the group with low levels of tumor necrosis factor (P less than 0.05 for both). The high levels of tumor necrosis factor were not due solely to decreased renal clearance, however, since the levels in the patients with heart failure were considerably higher than those in the nine patients with chronic renal failure (115 +/- 25 vs. 45 +/- 25 U per milliliter; P less than 0.05). CONCLUSIONS: These findings indicate that circulating levels of tumor necrosis factor are increased in cachectic patients with chronic heart failure and that this elevation is associated with the marked activation of the renin-angiotensin system seen in patients with end-stage cardiac disease.

Adult↗