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Biomedical subjects

R G Hahn

Publications and source records attributed to R G Hahn.

At least 217 records · Page 12Linked to original sources
PubMed1988

Neoadjuvant chemotherapy for locally advanced transitional cell carcinoma of the bladder: do local findings suggest a potential for salvage of the bladder?

Sixteen patients with locally advanced transitional cell carcinoma of the bladder were given two to four cycles of combination chemotherapy with methotrexate, vinblastine, doxorubicin hydrochloride (Adriamycin), and cisplatin (M-VAC) in an effort to reduce tumor size and enhance the potential for surgical resection. All patients had initial clinical staging (based on cystoscopy and cystoscopic biopsy, urine cytology, computed tomographic scanning, and excretory urography). Before each cycle, all patients had repeat clinical staging tests. Ten patients underwent postchemotherapy bilateral pelvic lymphadenectomy and radical cystoprostatectomy, and their bladders were examined histopathologically by step-sectioning techniques. One patient underwent abdominal exploration, bilateral pelvic lymphadenectomy, and ipsilateral partial cystectomy. Five patients had repeat clinical staging only without removal of their bladders. Of the 16 patients, 5 (31%) had residual invasive tumor and no tumor response. Three patients (19%) had a partial response, two of whom had only carcinoma in situ (one with prostatic duct involvement) and one of whom had stage pT1, NO, MO disease. Five patients (31%) had normal findings on computed tomographic scans, cystoscopy, biopsy, and urine cytology and thus had complete responses. In addition, 3 of 11 patients who underwent pathologic staging had no residual tumor on clinical and surgical staging and were complete responders. The overall (partial + complete) response rate was 69%, and the overall complete remission rate (pathologic + clinical staging) was 50%. These results suggest that the concept of possible salvage of the bladder with the current treatment program might be premature and must be applied selectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1988

Diagnostic ultrasound in general practice.

A three-year diagnostic ultrasound training project for generalists is described. Specific applications and a rationale for the use of ultrasound by general physicians are presented. The current status of training programmes, credentialing strategies, and desirable equipment characteristics are also discussed. Finally, benefits, liabilities and controversies in diagnostic ultrasound imaging are reviewed.

Abdomen↗
PubMed1988

Ethanol monitoring of irrigating fluid absorption in transurethral prostatic surgery.

The ethanol concentration in expired breath (EB-ethanol(A] was repeatedly measured in 50 patients undergoing transurethral prostatic surgery in which the irrigating fluid was 1.5% glycine + 2% ethanol in water. EB-ethanol(A) was compared at 10-min intervals to the serum sodium concentration, the serum glycine concentration, and the absorbed volume of irrigant. The EB-ethanol(A) was found to be related directly to the serum glycine concentration (R2 = 0.75) and, inversely, to changes in the serum sodium concentration (R2 = 0.81). The cumulative absorbed volume of irrigant could be predicted from a single EB-ethanol(A) reading at the end of each 10-min interval (R2 = 0.82); the reliability was improved by taking into account the absorption time (R2 = 0.89). Extravasation of irrigating fluid was indicated by a stable or increasing EB-ethanol(A) after the ethanol-tagged irrigant had been discontinued. Ethanol monitoring is a simple and inexpensive method of testing for the presence, and measuring the degree, of irrigant absorption in transurethral prostatic surgery.

Absorption↗
PubMed1988

Relations between irrigant absorption rate and hyponatraemia during transurethral resection of the prostate.

The serum sodium concentration (S-Na) and the volume of irrigating fluid absorbed were measured during 10-min periods in the course of 85 transurethral resections of the prostate (TUR). The hyponatraemic response to absorption of the irrigant was found to be dependent on the volume of fluid absorbed and the time required for the absorption. During the first 10 min of absorption the distribution volume of the irrigating medium was roughly equal to the extracellular space, but after this period the volume was greater. The sodium level could be compensated for further absorption to the extent of 200-300 ml irrigant per 10-min period; when this volume was exceeded, hyponatraemia was aggravated. The results indicate that in the development of the very low S-Na level typical of a severe TUR reaction, a rapid massive absorption is a more important factor than a large total absorbed volume.

Absorption↗
PubMed1988

Serum amino acid patterns and toxicity symptoms following the absorption of irrigant containing glycine in transurethral prostatic surgery.

The relationships between the serum concentrations of amino acids, the volume of irrigating fluid absorbed and symptoms of glycine toxicity were analysed in 18 patients who had undergone transurethral resection of the prostate and in whom intravascular absorption of irrigating fluid containing 2.2% glycine had been recorded. A mean of 7% of the transferred glycine could be detected in the serum within 10 min of irrigant absorption. The half-life of glycine in serum was twice as long when the volume of irrigant absorbed exceeded 1500 ml (100 min; n = 6), and the serum levels of alanine, aminobutyrate, proline and serine were significantly more elevated, than when the volume of irrigant absorbed was between 900 and 1300 ml (n = 6). Where the amount of glycine transferred exceeded 0.5 g.kg-1, symptoms of glycine toxicity developed, their onset coinciding with a rapid increase in the serum levels of non-essential amino acids other than glycine.

Absorption↗
PubMed1988

Blood volume during transurethral prostatic resection.

The variations in blood volume (BV), occurring in the course of 61 transurethral prostatic resections and estimated by the haemoglobin dilution method, were examined in relation to the type and volume of i.v. fluid given, the amount of irrigant absorbed and the blood loss. When dextran 40 was used (n = 16), the BV increased within 10 min by 2.7 times the volume infused, while for cumulative data relating to several 10-min periods in the course of surgery this factor was 1.3; for acetated Ringer solution (n = 45), the respective values were 0.5 and 0.3-0.4. The half-life of absorbed irrigating fluid in the circulation was between 5 and 10 min. In patients receiving dextran 40 the BV decreased by the volume of blood lost; however, when acetated Ringer solution was given, the BV decreased by only 60% of the blood loss.

Aged↗
PubMed1988

Obstetric ultrasound training for family physicians. Results from a multi-site study.

A practical program to train family physicians in obstetric ultrasound was tested with 13 family physicians. Each physician completed 6.5 days of course work and ultrasound laboratory apprenticeship prior to beginning a clinical preceptorship of approximately 14 months' duration. During the clinical preceptorship the physicians performed ultrasound studies in their own offices. All studies were reviewed by a local consultant radiologist utilizing examination data sheets and videotapes. At the conclusion of the training program, the physicians took a combined practical and written proficiency examination administered by an independent sonographer. Eight physicians completed the training, performing during the preceptorship an average of 78 examinations. The rated performance of the physicians improved markedly over the course of the preceptorship. During the last segment of the preceptorship the radiologist preceptors rated 94 percent of the ultrasound studies as acceptable, compared with 79 percent rated acceptable at the beginning of the preceptorship. Seven of the eight physicians completing the protocol took the proficiency examination: all passed. This study can provide a blueprint for an individual family physician to design his own training, or it can guide an academic department of family medicine in developing and evaluating ultrasound training programs for residents and practicing physicians.

Education, Medical, Continuing↗
PubMed1987

Combination hormone therapy for metastatic breast cancer. An ECOG study of megestrol and aminoglutethimide.

This study was performed to determine the toxicity and effectiveness of megestrol acetate used with aminoglutethimide-hydrocortisone in the treatment of patients with metastatic breast cancer. Forty-five patients were treated, 29 of whom were fully eligible. Twelve of the 45 who had diabetes and/or hypertension were also analyzed. All had measurable sites of disease. The median age was 63 years, and the median time from first recurrence to on-study was 19 months. Approximately half the patients already had chemotherapy, and about 90% had hormone therapy for advanced disease. The most common side effects were skin rash, weight gain, hyperglycemia, and renal and neurologic problems. No life-threatening or lethal toxicities were reported. The overall response rate (complete or partial) among the fully eligible patients was 34% (90% confidence intervals from 20% to 51%), with a 5-month median duration of response. Patients with soft tissue, visceral, and osseous disease responded. Seventy-two percent of fully eligible patients have progressed or relapsed. The median time to failure of treatment was 6 months, and the median survival time was 15 months.

Adult↗
PubMed1987

Influence of variations in blood haemoglobin concentration on the calculation of blood loss and volumetric irrigating fluid balance during transurethral resection of the prostate.

Blood loss in 38 patients undergoing transurethral resection of the prostate (TURP) was calculated in four different ways by using various reference blood haemoglobin determinations (B-Hb) during the course of preparation and surgery. Blood loss became greater the later the B-Hb was drawn. This increase was because variations in B-Hb acted to underestimate the loss of plasma. The variations also distorted the irrigating fluid balance to give too low values for the absorption of irrigating fluid. It is possible to correct for the errors in blood loss and volumetric fluid balance by the use of haemodilution factors. Haemodilution was greater in patients with complications such as absorption of irrigating fluid or excessive blood loss than in patients without such features if Ringer's acetate was used for i.v. fluid supplementation. With dextran 40, all patients had a similar degree of haemodilution.

Aged↗
PubMed1987

A randomized clinical trial of combination chemotherapy in advanced colorectal cancer.

One hundred and sixty-five patients with advanced colorectal cancer were entered into a prospectively randomized trial of combination chemotherapy comparing three 5-fluorouracil plus methyl CCNU (FM)-based regimens: FM plus ICRF-159 (FMI), FM plus triazinate (FMT), and FM plus vincristine (FMV). Patients were stratified according to performance status, anatomic site of primary indicator lesion, and prior chemotherapy. Those with abnormal kidney or liver function were randomized between FMI and FMV because triazinate depends on both hepatic and renal mechanisms for elimination. There were no significant differences between the treatment regimens in objective response rate (11%-17%), interval to progression (median, 10-14 weeks), or survival (median, 5-6 months). The primary side effect observed was hematologic toxicity, which tended to increase in severity with repeated courses of therapy. Although ICRF-159 and triazinate have been shown to have limited single-agent phase II activity against colorectal cancer in previous trials, neither agent combined with 5-fluorouracil plus methyl CCNU has an improved treatment effect compared with FMV. We do not recommend the further use of these regimens in the treatment of advanced colorectal cancer.

Adult↗
PubMed1987

A haemoglobin dilution method (HDM) for estimation of blood volume variations during transurethral prostatic surgery.

A method for estimation of blood volume changes during transurethral prostatic surgery is presented (haemoglobin dilution method (HDM]. It is based on a calculation of the patient's preoperative total haemoglobin content, from which losses are subtracted. The haemoglobin concentration of the blood is used as an indicator of dilution. The HDM was compared to the 131I-RISA technique in 10 patients undergoing transurethral resection of the prostate (TUR). The difference between the HDM and RISA in estimating the total operative procedure blood volume change was 0.03 +/- 0.12 l (ns) with a linearity of 0.90. The blood volume changes were also predicted by a fluid balance formula. With RISA as reference, the formula had a lower precision (0.24 l) and a poorer linearity (0.65) than the HDM. The HDM did not lose in accuracy if repeated several times during the TURs or if a theoretical formula for estimation of the preoperative blood volume was used.

Aged↗
PubMed1987

Factors influencing the osmolality and the concentrations of blood haemoglobin and electrolytes during transurethral resection of the prostate.

Twenty patients undergoing transurethral resection of the prostate (TUR) were followed every 10 min intraoperatively as well as 1 and 2 h postoperatively with measurements of blood haemoglobin concentration (B-Hb), serum sodium (S-Na), serum potassium (S-K), serum osmolality (S-osmol), blood loss, central venous pressure and volumetric determination of the irrigating fluid absorption. Changes in B-Hb correlated well with the sum of acetated Ringer solution given and intravascular irrigating fluid absorption. A transient decrease in S-Na of 1-4 mmol/l followed absorptions less than 300 ml. With larger intravascular absorptions, three stages of dilutive changes in S-Na and B-Hb are described. Extravascular absorptions resulted in mild blood parameter changes at various times after their occurrence. Absorption of irrigating fluid was associated with an increase in S-K. S-osmol decreased in conjunction with some absorptions, although the irrigating fluid was isotonic. Postoperative analyses of blood parameters gave only limited information about intraoperative complications. The only consistent pattern was associated with intravascular irrigating fluid absorption.

Aged↗
PubMed1987

Decrease in serum potassium concentration during epidural anaesthesia.

A mean decrease in the arterial serum potassium concentration (S-K) of 0.40 mmol/l (range 0-1.0) was found in 45 elderly men who were studied before and after induction of epidural anaesthesia (using mepivacaine 2% with adrenaline). The decrease was similar in patients who received acetated Ringer solution or dextran 40 in normal saline as intravenous fluid supplementation. No difference in S-K change was found between patients with a normal (less than 115 mumol/l) or elevated serum creatinine concentration. The decrease in S-K prevailed at the end of surgery except in patients with an elevated serum creatinine. Corrections of S-K for changes in arterial blood pH and rectal temperature during induction of anaesthesia did not explain the decrease in S-K. Correlations of clinical parameters such as the extension of anaesthesia, amount of intravenous fluid given and blood pressure changes gave conflicting results. A smaller decrease or no change in S-K was usually seen in arterial (n = 7) and venous (n = 7) samples when no intravenous fluid was given, as well as in venous samples when acetated Ringer solution was given (n = 6).

Aged↗
PubMed1987

Phase II clinical trial of triazinate in combination with mitomycin C for patients with advanced gastric cancer.

Thirty-three patients with advanced measurable gastric cancer were treated with a combination of mitomycin C and triazinate. Twenty-nine of these patients had failed prior chemotherapy. Nine patients (27%) had an objective tumor response (median duration, 10 weeks). Median survival of all patients treated was 21 weeks. This study demonstrates that carefully selected patients with advanced gastric cancer who have failed a trial of chemotherapy, but are still ambulatory and maintaining adequate nutrition are appropriate subjects for studies of new treatment regimens. Based on the observed objective tumor response rate and median patient survival, further studies of these drugs in combination for the treatment of advanced gastric cancer are indicated.

Adenocarcinoma↗
PubMed1987

The effect on survival of initial chemotherapy in advanced breast cancer: polychemotherapy versus single drug.

Since current clinical trials assessing new agents occur in patients with advanced breast cancer having failed one and sometimes many polychemotherapy programs, these new agents may not be given a fair trial. In an effort to assess the possibility of using an alternative study design, we analyzed older clinical trials that used a controlled study design, randomizing between a single new drug and an established polychemotherapy program with a cross-over design upon failure. We were interested in noting that the pooled data did display a slight survival advantage (median 3.7 months) for the group receiving polychemotherapy as initial therapy. The survival distributions were clearly not significant using the log rank test, but did approach significance using the Smirnov. It is apparent that, while some slight advantage does occur for that group of patients receiving initial polychemotherapy, the magnitude of this effect is not great and is short in duration. Serious consideration should be given to the assessment of new agents as first-line therapy, particularly should they have a unique mode of action or lessened morbidities or toxicities.

Antineoplastic Agents↗
PubMed1987

Treatment of metastatic islet cell carcinoma with a somatostatin analogue (SMS 201-995).

We used an octapeptide analogue of somatostatin, SMS 201-995, in dosages ranging from 150 to 450 micrograms/d administered subcutaneously in three daily doses for 1 to 16 months, to treat 22 patients with advanced malignant islet cell carcinomas. Of the 22 patients, there were 9 with gastrinomas; 3 with glucagonomas; 4 with insulinomas; 1 with ectopic production of parathyroid hormone; and 3 with mixed syndromes. The only biochemical marker in 1 patient was pancreatic polypeptide, and 1 patient had no demonstrable peptide production from the tumor. In 14 patients, dramatic decreases in the levels of circulating peptides (insulin, vasoactive intestinal polypeptide, gastrin, and glucagon) have been accompanied by major alleviations of symptoms. Steatorrhea appears to be the most significant toxicity. This analogue of somatostatin may be appropriate for use as early therapy in patients who have symptoms from syndromes related to islet cell carcinomas but in whom there is no immediate threat from tumor progression.

Adenoma, Islet Cell↗
PubMed1986

Treatment of the malignant carcinoid syndrome. Evaluation of a long-acting somatostatin analogue.

We studied the effects of a long-acting analogue of somatostatin (SMS 201-995, Sandoz) in 25 patients with histologically proved metastatic carcinoid tumors and the carcinoid syndrome. This drug was self-administered by subcutaneous injection at a dose of 150 micrograms three times daily. Flushing and diarrhea associated with the syndrome were promptly relieved in 22 patients. All 25 patients had an elevated 24-hour urinary excretion of 5-hydroxyindoleacetic acid (5-HIAA) (mean, 265 mg per 24 hours; range, 14 to 1079), which served as an objective indicator of disease activity. Eighteen of the 25 patients (72 percent) had a decrease of 50 percent or more in their urinary 5-HIAA levels, as compared with the pretreatment values. The median duration of this biochemical response was more than 12 months (range, 1 to greater than 18). Since no serious toxicity was observed, we conclude that SMS 201-995 may be appropriate for use as early therapy in patients with symptoms due to the carcinoid syndrome who have not responded to simpler measures.

Adult↗