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Biomedical subjects

R G Hahn

Publications and source records attributed to R G Hahn.

At least 19 recordsLinked to original sources
PubMed1992

A phase II study of recombinant human alpha-interferon in advanced hormone-refractory prostate cancer.

To determine the efficacy of recombinant human leukocyte alpha-interferon (IFL-RA) in advanced hormone-refractory prostate cancer, the authors treated 40 patients with IFL-RA administered intramuscularly at a dose of 10 x 10(6) U/m2 three times weekly. Toxicity was substantial and necessitated at least a 50% dose reduction in all but five patients during the first 1-2 months of therapy. No responses were observed in patients with bone metastases, but complete and partial regression of nodal disease were observed in two patients with extraosseous disease (overall response rate, 5%; 95% confidence interval, 0.64-17.75%). The authors conclude that IFL-RA cannot be recommended at this dose and schedule in patients with advanced prostate cancer, but additional study of its use in patients with nodal disease may be warranted.

Adenocarcinoma↗
PubMed1992

Chemotherapy for hormonally refractory advanced prostate carcinoma. A comparison of combined versus sequential treatment with mitomycin C, doxorubicin, and 5-fluorouracil.

One hundred forty-two patients with progressive, hormonally refractory advanced prostate carcinoma who had not received prior chemotherapy were randomized to receive either combination chemotherapy with 5-fluorouracil (5-FU), doxorubicin, and mitomycin C (FAM) or sequential chemotherapy with the same agents, i.e., mitomycin C, followed by doxorubicin on disease progression, followed by 5-FU. Objective tumor regressions were observed in 10 of 70 (14%) patients receiving the FAM treatment arm and 10 of 72 (14%) patients initially receiving mitomycin C. Of the 24 patients who received secondary therapy with doxorubicin alone, 3 (12.5%) achieved objective tumor regression. There were no responses among five patients who received tertiary therapy with 5-FU alone. The median survival time for all patients treated with the combination arm was 8.7 months, compared with 7.1 months for patients who received the FAM arm (P = 0.025). However, this modest survival advantage in favor of the FAM treatment arm must be weighed against significantly more myelosuppression experienced by these patients. The chemotherapeutic regimens used in this study have only minor clinical value in the treatment of hormonally refractory advanced prostate cancer.

Acid Phosphatase↗
PubMed1992

Streptozocin-doxorubicin, streptozocin-fluorouracil or chlorozotocin in the treatment of advanced islet-cell carcinoma.

BACKGROUND: The combination of streptozocin and fluorouracil has become the standard therapy for advanced islet-cell carcinoma. However, doxorubicin has also been shown to be active against this type of tumor, as has chlorozotocin, a drug that is structurally similar to streptozocin but less frequently causes vomiting. METHODS: In this multicenter trial, we randomly assigned 105 patients with advanced islet-cell carcinoma to receive one of three treatment regimens: streptozocin plus fluorouracil, streptozocin plus doxorubicin, or chlorozotocin alone. The 31 patients in whom the disease did not respond to treatment were crossed over to chlorozotocin alone or to one of the combination regimens. RESULTS: Streptozocin plus doxorubicin was superior to streptozocin plus fluorouracil in terms of the rate of tumor regression, measured objectively (69 percent vs. 45 percent, P = 0.05), and the length of time to tumor progression (median, 20 vs. 6.9 months; P = 0.001). Streptozocin plus doxorubicin also had a significant advantage in terms of survival (median, 2.2 vs. 1.4 years; P = 0.004) that was accentuated when we considered long-term survival (greater than 2 years). Chlorozotocin alone produced a 30 percent regression rate, with the length of time to tumor progression and the survival time equivalent to those observed with streptozocin plus fluorouracil. Crossover therapy after the failure of either chlorozotocin alone or one of the combination regimens produced an overall response rate of only 17 percent, and the responses were transient. Toxic reactions to all regimens included vomiting, which was least severe with chlorozotocin; hematologic depression; and, with long-term therapy, renal insufficiency. CONCLUSIONS: The combination of streptozocin and doxorubicin is superior to the current standard regimen of streptozocin plus fluorouracil in the treatment of advanced islet-cell carcinoma. Chlorozotocin alone is similar in efficacy to streptozocin plus fluorouracil, but it produces fewer gastrointestinal side effects than the regimens containing streptozocin. It therefore merits study as a constituent of combination drug regimens.

Adenoma, Islet Cell↗
PubMed1992

Amino acid concentrations in serum and urine after intravenous infusion of 1.5% glycine in prostatectomy patients.

Glycine 1.5% was given by intravenous infusion at a rate of 50 mg/min over 20 min to 10 patients (aged 57-79 years) scheduled for transurethral prostatectomy. The concentrations of amino acids in serum and urine were measured at 0, 10, 20, 50, 80, and 140 min in the experiments in order to study how elderly men handle a glycine load. The results show an increase in the serum concentrations of alanine, proline, glutamine, glycine, serine, and threonine. The apparent distribution volume for the excess glycine was 33 +/- 9 L, the half-life was 41 +/- 7 min, and the total body clearance was 0.56 +/- 0.08 L/min, while the renal clearance for glycine was 36 +/- 14 ml/min (mean +/- SD). There was an increase in the excretion of all amino acids that could be detected in the urine. The renal clearances of urea and creatinine was reduced in some of the patients. The absence of toxic symptoms is consistent with unchanged serum concentrations of ammonia and glutamate.

Aged↗
PubMed1992

Pharmacokinetics of ethanol in plasma and whole blood: estimation of total body water by the dilution principle.

The pharmacokinetics of ethanol in plasma and whole blood have been investigated and the results used to estimate the volume of total body water (TBW) by means of the dilution principle. Fifteen men (mean age 62 y) were given 0.6 g ethanol/kg body weight as an intravenous infusion over 1 h. The peak concentration of ethanol in plasma was 120 mg.dl-1 compared to 108 mg.dl-1 for whole blood. The disappearance rate of ethanol from plasma was 18.6 mg.dl-1.h-1 compared to 17.0 mg.dl-1.h-1 for the whole blood concentration-time data. The apparent volume of distribution of ethanol (Vz) was 0.54 l.kg-1 according to plasma kinetics compared to 0.59 l.kg-1 for the kinetics derived from whole blood. The mean area under the curve (AUC) was 294 mg.dl-1 x h for plasma kinetics compared to 266 mg.dl-1 x h for whole blood. The TBW was 40.9 l or 50.9% of body weight for the plasma concentration-time data. This agreed well with the 40.3 l or 50.1% of body weight obtained using whole blood.

Body Water↗
PubMed1992

Phase II trials of interferons-alpha and -beta in advanced sarcomas.

Interferons (IFNs)-alpha and -beta were administered to patients with metastatic sarcomas in two different Eastern Cooperative Oncology Group studies. In one study, patients received IFN-alpha 2b, 20 million units/m2 i.v. 5 days/week x 4, then 10 million units s.c.t.i.w. In the second study, patients received IFN-beta ser 180 million units t.i.w. Of 87 patients evaluable for response, there were three responses in 64 patients (5%) treated with IFN-alpha-2b and no responses in 23 patients treated with IFN-beta ser. Severe or life-threatening fatigue with decline in performance status complicated treatment of 37% of patients receiving IFN-alpha 2b and 17% of patients receiving IFN-beta ser. Further investigation of IFNs in sarcomas should depend on evidence from preclinical studies demonstrating synergistic effects of IFNs combined with a cytoreductive modality which has proven activity in these malignancies.

Adult↗
PubMed1992

Haemoglobin dilution from epidural-induced hypotension with and without fluid loading.

The blood haemoglobin concentration (B-Hb) was measured repeatedly to reflect dilution or concentration changes of the blood during onset of lumbar epidural anaesthesia in 90 elderly men. With crystalloid volume loading (10 ml.kg-1 b.w.), the decrease in B-Hb was twice as great for those who developed hypotension during the onset of the blockade as for patients whose arterial pressure remained normal (P less than 0.001), both when epidural anaesthesia was induced with plain mepivacaine, and when mepivacaine plus adrenaline was used. In a control group where no fluid loading was performed, there was no consistent change in the haemoglobin level, irrespective of blood pressure reaction to the blockade. The results suggest that crystalloid fluid loading allows an increase in blood volume in epidural-induced hypotension.

Aged↗
PubMed1992

Serum potassium, catecholamine levels and ECG during field block for inguinal hernia surgery.

The purpose of this study was to find out whether hypokalaemia and associated ECG changes occur as a result of field block for hernial repair, alone or in combination with surgery. We recorded the ECG and measured the serum potassium and the plasma catecholamine concentrations at 10-min intervals in three groups of patients. In Group 1 (n = 7) and in Group 2 (n = 7), the blockade was instituted with prilocaine 0.5% and adrenaline 1:250,000, while in Group 3 plain prilocaine 0.5% was used. In Group 1 surgery was withheld for 40 min, while in Groups 2 and 3 surgery started as soon as the blockade became effective. There was a prolonged 4 to 5-fold elevation of the plasma adrenaline level from the adrenaline-containing solutions, the peak being 2.44 +/- 0.48 nmol/l (mean +/- s.d.) 10 min after the blockade had been instituted. The S-K level was unchanged in Group 1, while in Group 2 it decreased from 4.14 +/- 0.33 mmol/l to 3.91 +/- 0.29 at 60 min (P less than 0.05). An ECG pattern consistent with hypokalaemia did not develop. In Group 3, with plain prilocaine, there was a significant increase in the S-K level from 3.86 +/- 0.21 mmol/l to 4.08 +/- 0.36 at 40 min (P less than 0.05).

Adult↗
PubMed1992

Ethanol monitoring of transurethral prostatic resection during inhaled anesthesia.

The purpose of this study was to examine the precision of a method of breath-alcohol analysis used to monitor absorption of irrigating fluid during transurethral resection of the prostate performed under inhaled anesthesia. A breath-alcohol analyzer (Alcolmeter SD-2) was placed between the endotracheal tube and the Bains' circuit. The concentration of ethanol in the breath, serum sodium concentration, and volumetric fluid balance were measured at 10-min intervals during 38 operations when the irrigating fluid contained 1.5% glycine and 1% ethanol. Ethanol monitoring detected absorption rates that exceeded 14 +/- 8 mL/min (mean +/- SD). In 17 patients in whom hyponatremia developed immediately in connection with absorption, the volume of irrigating fluid absorbed (up to 1950 mL) could be predicted from a single expired-breath test with a standard error of 325 mL. When the alcohol measurements were corrected for absorption time, the standard error was 215 mL. Seven other patients received 2.2% wt/vol glycine as irrigating fluid, and ethanol (0.35 g/kg) was administered by intravenous infusion. The direct and indirect measurements of the blood-alcohol concentration agreed well. These results confirm that ethanol monitoring is a viable technique during inhaled anesthesia for transurethral resection of the prostate.

Absorption↗
PubMed1992

Diagnostic and therapeutic tools for the family physician's office of the 21st century.

Several new technologies are available to family physicians; however, numerous factors influence a physician's decision to adopt them. This study sought to determine interests and problems related to adopting new technology. The survey population was a group of family physicians who visited our scientific exhibit at the 1990 meeting of the American Academy of Family Physicians (AAFP). A 13-item questionnaire collected information on their use of and/or interest in technological procedures and equipment. Respondents were interested in a variety of new technological procedures. The most important criteria when considering new technology were training, costs, and office scheduling. The emphasis on outpatient care makes it increasingly important for family physicians to use modern technology in their offices and for departments of family medicine to offer training in these procedures. Our study provides a springboard for a broader discussion of the problems involved in selecting and implementing new technology in family practice.

Diagnostic Tests, Routine↗
PubMed1992

Acid-base status following glycine absorption in transurethral surgery.

Forty patients were studied at precisely timed 10 min intervals during transurethral prostatic resection under epidural analgesia. Blood gases, serum sodium, and volumetric irrigating-fluid balance were measured. A decrease in the serum sodium level of less than 5 mmol litre-1 was recorded in 28 patients (the 'normal TUR' group). In 12 patients, the decrease was 5 mmol litre-1 or more, which corresponded to an average absorption of irrigant of 1 litre of 2.2% glycine solution (range 0.6-2.9; the 'absorption' group). Mild metabolic acidosis often developed during the operations, but this was of similar degree in the two groups. It was concluded that uptake of irrigating fluid containing glycine does not alter the acid-base status so long as the TUR syndrome does not develop.

Absorption↗
PubMed1992

Obstetric ultrasound by family physicians.

Obstetric ultrasound examination is a useful diagnostic procedure for family physicians who select appropriate equipment, observe indications, understand limitations, and work toward performance mastery. The knowledge obtained during an examination assists clinical decision making and reduces liability. This is particularly true for rural and underserved communities where family physicians provide the majority of prenatal and comprehensive perinatal care. Mastery of obstetric ultrasound techniques can also lead to developing amniocentesis skills and serve as an aid to external cephalic version. The equipment does not require extensive maintenance and is available at all hospitals. Many offices and group practices have found purchase of this equipment to be cost effective. Based on clinical experience in family practice and a review of the medical literature, an approach to skill acquisition and quality assurance is described.

Amniocentesis↗
PubMed1991

Does histologic grade in soft tissue sarcoma influence response rate to systemic chemotherapy?

To assess whether chemosensitivity in metastatic soft tissue sarcoma (STS) is influenced by the histologic grade of the tumor, the authors retrospectively analyzed tumor responses to doxorubicin-based chemotherapy in four prospective studies conducted at the Mayo Clinic, Rochester, Minnesota, between 1976 and 1984. A total of 131 patients with metastatic STS were included in these trials. All pathologic material was reviewed by one pathologist (H.M.R.) and graded according to the four-tier grading system of Broders. One hundred and sixteen patients were accepted for analysis. Objective regression rates according to grade were as follows: Grade 4, 55% (22 of 40 patients); Grade 3, 23% (7 of 31 patients); Grade 2, 19% (5 of 27 patients); and Grade 1, 0% (0 of 3 patients). Fifteen nongradable sarcomas were analyzed separately (27% [4 of 15]). In contrast to several reports suggesting that grade does not effect response, the authors found differences in response rates to be statistically significant for Grade 2 versus Grade 4 (P = 0.003) and Grade 3 versus Grade 4 (P = 0.006), but not for Grade 2 versus Grade 3 (P = 0.7). Additional comparisons adjusted for the histologic type of STS, chemotherapeutic regimen, performance status, age, and prior treatment confirmed these results. These results suggested that, in addition to being an important prognostic factor for survival in newly diagnosed STS, histologic grade may correlate with the probability of response and should be considered a stratification factor in future studies.

Adolescent↗
PubMed1991

Phase II evaluation of menogaril in patients with advanced hypernephroma.

Fifteen patients with advanced renal cell carcinoma were treated with Menogaril, 200 mg/m2 by one-hour, intravenous infusion at four-week intervals. No objective regressions were observed. Median time to progression was two months, and median survival was seven months. All patients experienced neutropenia. Platelet toxicity was negligible. Venous irritation and phlebitis at the infusion site was seen in 47% of patients. Menogaril as administered in this protocol is ineffective in advanced renal cell carcinoma.

Adult↗