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Biomedical subjects

N Schmidt

Publications and source records attributed to N Schmidt.

At least 19 recordsLinked to original sources
PubMed1992

Stereoselective determination of the enantiomers of methadone in plasma using high-performance liquid chromatography.

An enantioselective high-performance liquid chromatographic assay for the quantification of methadone in human and beagle plasma is described. The procedure involves extraction of methadone from alkalized plasma into hexane-isoamyl alcohol (99:1, v/v). Stereoselective separation was achieved with a silica column with covalently bound alpha 1-acid glycoprotein (Chiral-AGP) without any derivatization procedure. The detection wavelength was set at 215 nm. Using an internal standard provided reliable control of the extraction procedure as well as quantification of the enantiomers of methadone. The limit of quantification was found to be 2.5 ng/ml. The method was demonstrated to be sufficiently sensitive for stereoselective pharmacokinetic studies of methadone.

Adult↗
PubMed1992

Subjective and objective effects of intravaginal electrical myostimulation and biofeedback in patients with genuine stress urinary incontinence.

A group of 36 patients (18 premenopausal and 18 postmenopausal), all suffering from genuine stress urinary incontinence, underwent conservative treatment with 6 sessions of intravaginal electromyostimulation followed by 6 sessions of biofeedback; 89% of patients reported an improvement, 5.5% considered themselves cured and 5.5% reported no change. Intravaginal pressure measured before and after therapy increased by an average of 11 cm H2O in premenopausal patients and 17 cm H2O in the postmenopausal group. Intravaginal pressure increased in all patients and, according to maximal urethral closure pressure, this increasing intravaginal pressure was observed even in patients with low pressure urethras. The urodynamic factors studied were functional length, maximum urethral closing pressure and pressure transmission, together with urethral surface at rest and during stress, and residual surface. No significant changes were noted before and after treatment. The excellent subjective results contrast with the absence of improvement in these values.

Adult↗
PubMed1992

Pancreatic duct obstruction treated with percutaneous antegrade insertion of a metal stent: report of two cases.

Expanding metal stents were used to treat symptomatic pancreatic duct obstruction in two patients with chronic pancreatitis. Both patients initially underwent percutaneous external pancreatic duct drainage and then had metal stents inserted for internal drainage. Both patients remained asymptomatic, and the stents were patent during short-term follow-up periods of 6 and 9 months, respectively. Percutaneous insertion of metal stents, which can be performed to treat pancreatic duct obstruction after a trial of external drainage has been shown to relieve the patient's symptoms, should be considered as an alternative to endoscopic stent placement or surgical drainage.

Aged↗
PubMed1991

Efficient management of adrenal tumors.

A retrospective analysis was carried out on 121 patients with primary adrenal tumors operated on at 2 Vancouver hospitals between the years 1970 and 1990. The purpose of the study was to identify discriminating factors between the various diagnoses in order to minimize both the time and the cost of the investigative process. There were 57 cortical adenomas, 35 pheochromocytomas, 15 carcinomas, 8 cases of cortical hyperplasia, and 6 miscellaneous tumors. The mean time from the onset of symptoms to diagnosis of those patients presenting with an identifiable syndrome was 48.3 months. Those with a hypertensive syndrome presented significantly later than those with Cushing's syndrome (57.7 months versus 22.8 months, p less than 0.01). There was a significant delay in diagnosis in those patients with hypertension on the basis of an aldosteronoma as compared with those with hypertension secondary to a pheochromocytoma (75.4 months versus 36.1 months, p = 0.02). Cortical carcinomas were significantly larger than benign cortical tumors (12.7 cm versus 5.5 cm). No malignant neoplasm measured less than 5 cm in diameter. Diagnostic sensitivity for intravenous pyelogram (IVP) was 59%, for ultrasound 71%, for venography 50%, for meta-iodobenzylguanidine (MIGB) (pheochromocytoma only) 80%, and for angiography 70%. However, for those patients with adrenal carcinomas, angiography was positive in 100% of cases. Computed tomography (CT) was the most sensitive localizing investigation with a sensitivity of 98%. While other localizing techniques were less sensitive than CT, they may still play a useful role in selected situations. Factors causing delay in diagnosis and the role of the various imaging modalities are discussed.

Adenoma↗
PubMed1991

Effect of occluding the urethra while recording urethral stress profile.

The correlation between clinical and tonometric incontinence is frequently poor, with urethral profile results that do not correspond to clinical reality. Among potential causal factors, we have attempted to determine the importance of the absorption of kinetic energy from the mass of urine driven against the urethral captor (the hydraulic ram effect). Twenty patients (average age 50 +/- 10 years, para 2) suffering from genuine stress urinary incontinence, underwent urodynamic investigation with a constant air-flow pneumatic catheter equipped with two captors separated by an inflatable cuff located just above the urethral captor to block the inrush of urine into the urethra. After cystometric examination had excluded an unstable bladder, two urethral profiles were registered successively, first with cuff deflated, and then with cuff inflated. The values for urethral functional length (FL) and transmission factor (TF) show no significant changes. The values for the maximal urethral closing pressure (MUCP) were significantly lower in the second profile (cuff inflated) in 18 of 20 cases (average decrease 7 cm H2O), which corresponds to 14 percent of the average MUCP measured during the first profile (cuff deflated). The depression quotient increased from an average 0.80 to 1.05 from first to second profile. This study allows quantification of the urethral "hydraulic ram effect" which modifies determination of the MUCP during registration of urinary stress profile.

Female↗
PubMed1978

[Long term effects of splenectomy on the immune-status of Hodgkin's disease patients depending on the modality of treatment (author's transl)].

In a total group of 103 Hodgkin's disease patients the immune-status of splenectomized and non-splenectomized individuals is compared in subgroups characterized by the modality of treatment (RT, CT, RCT). The mitogenic stimulation of peripheral lymphocytes showed a decreased response of splenectomized patients in each therapy group. The percentage, but not the absolute number/mm3, of peripheral T-cells was reduced after splenectomy. Splenectomized patients, who received combined radiation and chemotherapy showed significantly lower IgM-levels than non-splenectomized patients after the same treatment. EBV-VCA-titers and skin-test-reactivity were not influenced by splenectomy.

Hodgkin Disease↗
PubMed1978

[Hodgkin's disease: effect of spenectomy on the immune status (author's transl)].

In 22 untreated Hodgkin's patients the following parameters were studied before and after splenectomy: the total WBC, lymphocytes, B- and T-cells and mitogenic stimulation of peripheral lymphocytes using autologous and control serum. The results were correlated to patient groups with favourable and unfavourable prognosis according to pathological stage, histology, spleen involvement and constitutional symptoms. 1. All Patients. Significant increase of the absolute number of peripheral lymphocytes and B-cells. Significant increase of the spontanous DNA synthesis in the presence of AB-control serum, but no change after mitogenic stimulation of peripheral lymphocytes. No change in the number of peripheral T-cells. 2. Patients with Favourable Prognosis. Significant increase of the absolute number of peripheral lymphocytes and B-cells. Significant increase of the spontanous DNA synthesis in the presence of AB-control-serum. Significant decrease of the T-cell function (PHA- and Con-A-stimulation in the presence of autologous serum). Significant decrease of the PHA-, Con-A- and PWM stimulation rate using control serum in the lymphocytic predominance and nodular sclerosis group. No change in the number of peripheral T-cells. 3. Patients with Unfavourable Prognosis. No change in the absolute number of B-cells, of the spontanous DNA-synthesis using autologous serum and of the PHA- and Con-A-stimulation. Significant increase of the EBV-induced blastogenesis in the mixed cellularity and lymphocytic depletion group.

Adolescent↗
PubMed1977

Coexistence of pheochromocytoma, adrenal adenoma and hypokalemia.

A 56-year-old woman had a 22-year history of hypertension. Investigation showed hypokalemia and kaliuresis without pronounced suppression of plasma renin activity or elevation of urinary aldosterone excretion. There was biochemical evidence of catecholamine metabolite excess but the usual clinical features of pheochromocytoma were absent. Laparotomy revealed a pheochromocytoma and adrenal adenoma in the right adrenal gland. Excision of the tumours was followed by resolution of the hypertension and metabolic abnormalities.

Adenoma↗
PubMed1977

Hypoglycemia following excision of pheochromocytoma.

In two patients hypoglycemia developed in the immediate postoperative period after removal of a pheochromocytoma. In one patient the serum insulin value was elevated when he was hypoglycemic. Preoperative preparation of patients with pheochromocytoma requires use of an alpha-adrenergic blocking agent to decrease blood pressure and allow the plasma volume to expand; in the two patients referred to phenoxybenzamine was given orally. It is difficult to recognize hypoglycemia postoperatively because of the altered consciousness associated with a major operation, analgesics, anesthetic agents and the effects of adrenergic blocking medications; hence the physician must watch closely for this complication.

Adrenal Gland Neoplasms↗
PubMed1976

[Results of radiotherapy of bronchial carcinoma (author's transl)].

In a joint retrospective study by 17 radiotherapy clinics in German-speaking countries the results of treatment of bronchial carcinoma after radiotherapy were analysed in 7503 cases. The age peak was between the 60th and 70th year. Squamous-cell carcinoma was the most frequent histological type, followed by anaplastic carcinoma, with adenocarcinoma being rare. There was a high proportion of histologically not clearly identified cases (27% in central and 35% in peripheral carcinomas). Survival rate at one year was 31% for central (3662 patients) and peripheral (961 patients) tumours, but only 2% at five years. Prognostically there was no difference between histological types and kind of radiotherapy or technique, but total dose affected survival rate. At a total dose of less than 5000 rd the survival rate at five years was minimal. The prognosis of combined surgical and radiotherapeutic measures was slightly better than with a radiotherapy alone, but results were unpredictable for the individual case. It is concluded that radiotherapy aiming at cure should be used in imoperable bronchial carcinoma if the tumour state and general condition of the patient appear to make a cure possible. But if this is not the case, radiotherapy should be used only palliatively, i.e. only to ameliorate symptoms.

Adenocarcinoma↗
PubMed1976

[Results of radiotherapy of prostatic carcinoma as monotherapy].

A report is given of the results of histopathologic examinations of subsequent biopsies carried out on 54 patients with prostate carcinomas and of the clinical development of the prostate carcinomas of 89 patients. All these patients were treated only by therapeutic radiology. Then follows a discussion whether the radiation or the hormone therapy has the preponderant values. The possible complications of the two therapy methods are compared.

Aged↗