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Biomedical subjects

S Peters

Publications and source records attributed to S Peters.

At least 145 records · Page 8Linked to original sources
PubMed1997

Right ventricular cardiomyopathy: diffuse dilatation, focal dysplasia or biventricular disease.

Non-coronary ventricular tachyarrhythmias originating from the right ventricle are frequent events associated in many cases with structural and functional abnormalities of the right ventricle. Primary right ventricular affections such as arrhythmogenic right ventricular dysplasia and secondary right ventricular involvements such as in dilated cardiomyopathy must be distinguished. The value of conventional diagnostic procedures is undetermined. A total of 73 patients (41 males, mean age 40.6 +/- 11.4 years) with left bundle branch block ventricular arrhythmias and angiographic aspects of right ventricular outpouchings or aneurysms were divided into three groups: Group 1: diffuse right ventricular dilatation without left ventricular affection, Group 2: focal right ventricular abnormalities (dysplasia) Group 3: biventricular disease. The results of standard ECG, angiography and programmed ventricular stimulation were analysed retrospectively. Clinical monomorphic ventricular tachycardia was more often in diffuse dilatation (82%) and focal dysplasia (57%). In these two groups programmed ventricular stimulation was able to induce clinical tachycardias at a high degree (57-82%). In cases of biventricular disease cardiac arrest as the primary event without inducibility of monomorphic ventricular tachycardia was the predominant feature (44%). Standard ECG disclosed localised right precordial QRS prolongation in 'normal' QRS morphology, incomplete and complete right bundle branch block in 66 patients in all three subgroups. Other ECG findings such as left ventricular hypertrophy in four patients with heart failure and single premature beats and left bundle branch block in a patient with rapid ventricular tachycardia and ventricular fibrillation was found only in group 3 supposed to be the most heterogeneous group. In summary, angiographic classification used in this study demonstrates different morphological aspects of right ventricular cardiomyopathy with ventricular tachyarrhythmias as the major clinical aspect. High risk patients with diffuse dilatation or biventricular disease can be identified. Only patients with the angiographic aspect of focal dysplasia seem to be possible candidates for catheter ablation techniques.

Adult↗
PubMed1997

Engraftment of hematopoietic stem cells in nonmyeloablated and myeloablated hosts.

Hematopoietic stem cell engraftment has traditionally been assessed in irradiated murine hosts. More recently, we and others have shown that engraftment is virtually quantitative in host animals who have received no preconditioning myeloablation. It appears that at the stem cell level, engraftment may even be favored in the normal host. The final phenotypic readout in the engrafted animal is then determined by competition between the engrafted stem cells and the number of residual host stem cells. Further studies have indicated that with cytokine exposure in vitro, in vivo or 5-fluorouracil exposure and consequent stimulation of primitive hematopoietic stem cells to enter cell cycle, an engraftment defect relating to long-term engraftment occurs. This occurs in the face of an expansion of cycling surrogate stem cells as mirrored by the high proliferative potential colony-forming cell. These data indicate that the phenotype of the hematopoietic stem cell, as assessed in vitro, may not give insight into the phenotype of these cells in vivo.

Animals↗
PubMed1997

Effects of toxin magnitude on taste aversion and taste-potentiated aversion to visual cues in chicks (Gallus domesticus).

Chicks (n = 208) received CS solutions of red water, red 2.0% vinegar, clear water, or clear 2.0% vinegar, followed by an I.P. injection of 0.4 M lithium chloride at 0.2% or 0.5% body weight, and then received 2 test trials with red water or clear 2.0% vinegar. In testing with red water, measures of latency to start drinking, latency to make 9 more drinks after the first, and amount drunk provided reliable evidence of potentiated aversion to visual cues with a greater magnitude of potentiation shown following the 0.2% injection than the 0.5% injection. In testing with clear vinegar, the "9-drink" latency measure and amount drunk yielded reliable evidence of taste aversion, with greater aversion shown following the 0.5% injection than the 0.2% injection. Findings are discussed in terms of associative and taste primacy views of potentiation effects.

Animals↗
PubMed1997

Albuterol via Turbuhaler versus albuterol via pressurized metered-dose inhaler in asthma.

BACKGROUND: Inhaled albuterol is most commonly self-administered by patients using a pressurized metered-dose inhaler (pMDI) but patients often have difficulty using the device. Dry powder devices such as the multi-dose, inspiratory flow driven inhaler (Turbuhaler) are often better handled by patients. OBJECTIVE: We sought to compare the efficacy and tolerability of 100 micrograms of albuterol delivered by a multi-dose, inspiratory flow driven inhaler (Turbuhaler) to a standard dose (200 micrograms) delivered by a pMDI (Ventolin) in chronic reversible obstructive airways disease. METHOD: In 6 centers, we studied 37 adults [19 men and 18 women, mean age 39 +/- 12 years; mean baseline forced expiratory volume in one second (FEV1) 72 +/- 13% (% predicted)] with stable but symptomatic reversible obstructive airways disease as demonstrated by 15% or greater increase in FEV1 following two puffs (200 micrograms) albuterol by pMDI. The crossover design comprised a 1-week run-in and two 2-week treatment periods separated by a 1-week washout. At the start and end of each treatment period, FEV1 was measured at the clinic. Patients self-administered albuterol 100 micrograms (2 x 50 micrograms) via Turbuhaler or 200 micrograms (2 x 100 micrograms) via pMDI in a double-blind fashion four times daily. Morning and evening peak expiratory flow (PEF) was noted daily. All non-study bronchodilators were withheld while open-label albuterol pMDI was offered for rescue. RESULTS: Of the 37 patients, 30 used inhaled steroids in constant doses throughout the study, one used inhaled cromoglycate and six used no anti-inflammatory therapy. There was no difference between treatment periods in morning PEF, diurnal fluctuation in PEF, increase in PEF following study drug, baseline FEV1 and FEV1 increase following study drug. Although there was no difference in symptom scores between treatments, the use of rescue beta 2-agonist was slightly but significantly higher during the Turbuhaler treatment period (1.34 versus 1.08 inhalations/ day, P = .04). Compliance with study drug was slightly but significantly lower during the Turbuhaler treatment period (87 versus 95%) such that the total number of beta 2-agonist puffs inhaled (scheduled plus rescue) was similar between treatments. With regard to adverse events, both treatments were well tolerated. CONCLUSIONS: These results suggest that the efficacy and tolerability of albuterol 100 micrograms qid inhaled via Turbuhaler is similar to albuterol 200 micrograms qid, inhaled via pMDI in stable reversible obstructive airways disease.

Adult↗
PubMed1997

[Mayo duplication in treatment of incisional hernia of the abdominal wall after conventional laparotomy. Results of a retrospective analysis and comparison with the literature].

About 10% of patients undergoing conventional laparotomy will develop incisional hernias. Traditionally these hernias are in this country most often repaired by a Mayo-duplication. In this retrospective analysis we investigated a consecutive series of 114 patients (mean age: 53 (11-87) years, gender ratio m:f 1.2:1.97% electively operated) with 135 hernias, operated between 1/1985 and 12/1992 by a standard Mayo-procedure. Recurrence-rates and quality of life were evaluated by clinical examination. The mean follow-up time was 5.7 (2.5-10.2) years with a follow-up rate of 84.4%. The overall recurrence rate was 53.5%. Further uni- and multi-variate analysis was unable to find any clinically relevant risk factors for hernia development. Health related quality of life was evaluated with a validated index at the time of their follow-up visit. There were no differences in patients without a hernia recurrence (n = 52) when compared to those with an actually present recurrence (n = 36). However, physical function of all patients was significantly impaired when compared to healthy individuals. According to our results and those reported by others the Mayo-duplication when applied to all patients leads to non-acceptable results and implantation of auto- or alloplastic material should be considered more frequently.

Abdominal Muscles↗