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Biomedical subjects

J B Aust

Publications and source records attributed to J B Aust.

At least 19 recordsLinked to original sources
PubMed1991

Biliary pancreatitis. Operative outcome with a selective approach.

To evaluate the efficacy of a selective approach to biliary pancreatitis, we reviewed the outcomes in 276 consecutive patients undergoing operations for this diagnosis during a 7-year period. Initial conservative therapy resulted in elective operations in 63% and urgent operations in 37%. Only 10 patients (3.6%) required primary pancreatic operations, 50% of them as emergencies. The proportion of common duct surgical explorations fell from 70% of those operated immediately after hospital admission to 20% by the third hospital day. Overall mortality was 1.8% but was increased to 30% in patients having an initial pancreatic operation. We conclude that a selective approach to biliary pancreatitis allows the operation to be performed electively in most patients and is associated with a low mortality and an acceptable length of stay. Most common duct stones pass spontaneously permitting cholecystectomy alone.

Acute Disease↗
PubMed1988

DNA-mediated transfection as a model for oncogenesis.

DNA transfer technology has greatly contributed to progress in understanding molecular biology and genetics. In recent years, great efforts have been expended to determine the oncogenic potential of single, defined genes or complex gene mixtures as a prelude to defining the role those genes may play in neoplastic transformation in vitro and tumor induction in vivo. This paper reviews the currently available DNA transfection techniques and their application toward understanding cancer initiation and progression, and how the in vitro and animal models may apply to human cancer.

Animals↗
PubMed1987

Phenotypic changes and gene expression in human colon mucosal epithelial cells upon transfection of a SV40 DNA-gpt recombinant.

Phenotypic changes (increased longevity, decreased growth factor requirements, altered cell surface features, growth in semisolid agarose, and SV40 T antigen expression) suggesting in vitro transformation were displayed by human normal colon mucosal epithelial cells transfected with pSV3gpt, a pBR322 recombinant containing the SV40 "early" T antigen coding region and the dominant selectable marker bacterial gene, xanthine-guanine phosphoribosyltransferase. In contrast, control cultures which received neither DNA nor the recombinant pSV2gpt (which is identical to pSV3gpt but lacks the SV40 T antigen region) were not phenotypically altered.

Antigens, Viral↗
PubMed1987

Orchiectomy during herniorrhaphy: what should we tell the patient?

Although orchiectomy is rarely required during inguinal herniorrhaphy, it is frequently a topic of preoperative concern. Our study disclosed a concomitant orchiectomy rate of 2 percent during 1,817 groin herniorrhaphies. The risk of orchiectomy was greatest in patients with incarceration (relative risk 22 times) but was also increased by herniorrhaphy for recurrence (relative risk 8 times) (Table II). On the other hand, patients undergoing repair of a primary reducible hernia were at low risk. Of the 29 patients undergoing orchiectomy, only 12 of the procedures were performed for specifically recorded testicular or spermatic cord abnormalities. The precise reason for orchiectomy was often not stated or was vague. We conclude that orchiectomy is more likely to be associated with repair of complicated hernias and that permission for possible orchiectomy should be obtained from these patients preoperatively. On the other hand, consent for orchiectomy and detailed discussion is unwarranted for patients with primary reducible hernias. In addition, orchiectomy during herniorrhaphy should be limited to cases of specific testicular and cord abnormalities, and the reason for orchiectomy should be clearly documented in the operative record.

Adult↗
PubMed1987

Gastric devascularization.

Gastric devascularization has been reported to effectively control massive hemorrhage from stress related gastric mucosal injury with acceptable mortality and morbidity rates. Since this type of injury formation is partially based upon decreased gastric mucosal blood flow, the success of devascularization seems paradoxical. Thus, gastric devascularization was performed upon miniature swine and the gastric mucosal blood flow was serially measured in order to attempt to explain its efficacy. Total gastric mucosal blood flow decreased immediately, a maximum 36 per cent at 60 minutes. At three hours, gastric mucosal blood flow, although still significantly lowered (11 per cent), had begun a recovery that was total at one week. These results suggest that the efficacy of devascularization lies in its ability to modulate decreased gastric mucosal blood flow and, thereby, stop hemorrhage from established lesions. The rapid rebound of gastric mucosal blood flow to near normal levels prevents extension of the erosive process. These factors form the physiologic basis for the efficacy of gastric devascularization.

Animals↗
PubMed1986

Effects of gastrin, glutamine, and somatostatin on the in vitro growth of normal and malignant human gastric mucosal cells.

This study evaluated the dose-related trophic effects of glutamine, gastrin, and somatostatin on the in vitro growth of human gastric cancer cells and normal human gastric mucosal cells. Quadruplicate cell cultures were seeded into growth medium with or without glutamine, gastrin, or somatostatin. After 72 hours' incubation, cells were counted and their numbers compared with those of controls. Glutamine and gastrin stimulated the growth of both normal and malignant gastric mucosal cells. Compared with normal cells, the malignant cells responded to these growth factors at lower concentrations. Somatostatin enhanced growth of gastric cancer cells at all concentrations and inhibited growth of normal cells at high concentrations. Further studies on the responsiveness of gastric adenocarcinoma to gastrointestinal tract hormones may elucidate mechanisms of oncogenesis and suggest new therapeutic avenues for patients with gastric cancer.

Adenocarcinoma↗
PubMed1986

Evaluation of nonpalpable breast lesions. Experience in a training institution.

Biopsy directed by needle localization is a safe and relatively simple method of obtaining abnormal tissue for histologic examination without sacrificing surrounding normal breast tissue. In the setting of a training institution, accurate results can be expected as technical skills are obtained by a variety of housestaff. In this series of 70 biopsies, the lesion targeted on mammography was removed on the initial attempt in all but 1 instance, for an overall accuracy of 99 percent.

Adenofibroma↗
PubMed1986

Pancreatic cancer: continuing diagnostic and therapeutic dilemma.

Improved survival for patients with cancer of the pancreas awaits future therapeutic advances. A more immediate objective for these patients is to provide accurate diagnosis and effective palliation. Adherence to a diagnostic strategy should provide an accurate diagnosis with the least number of tests, minimizing cost to the patient in terms of both money and discomfort. Effective palliation using a variety of available techniques can and should be accomplished expeditiously in order to extend useful survival.

Adult↗
PubMed1986

The value and cost effectiveness of abdominal roentgenograms in the evaluation of stab wounds to the abdomen.

The value of roentgenograms of the abdomen in the evaluation and management of stab wounds to the abdomen has not been well documented. This retrospective study demonstrates that the overwhelming majority of patients with injury requiring repair have normal roentgenograms. We also found that, even when abnormal, abdominal roentgenograms make a negligible contribution to the evaluation in these patients. These findings indicate that abdominal roentgenograms are not cost effective in patients with stab wounds to the abdomen and should not be obtained on a routine basis.

Abdominal Injuries↗
PubMed1985

Hemicorporectomy.

Translumbar amputation (hemicorporectomy) was first successfully performed in 1961 after cadaver feasibility dissections. It is useful for certain slow-growing malignancies of the pelvis and perineum and for patients with advanced sepsis involving pelvic bony structures. As indicated by our 20-year experience, the operation may be rewarded by control of a malignant process (two patients) and/or relief from chronic pelvic sepsis (four patients), survival and discharge from the hospital after lengthy rehabilitation (six patients).

Adult↗
PubMed1985

Glucagon enhances growth of cultured human colorectal cancer cells in vitro.

Early passage in vitro cultures of colorectal adenocarcinoma cells were used to determine if glucagon exerts a direct effect on growth of human colon cancer cells. Growth response assays indicated that glucagon generally stimulated growth between 2 and 10 micrograms/ml, with peak responses at 5 to 10 micrograms/ml. When glucagon-treated and control cultures were compared, 12 of the 14 cultures (86 percent) were stimulated by glucagon, with an increase in cells from 41 to 100 percent. The other two cultures did not respond to glucagon. These in vitro results suggest that glucagon may enhance growth of most colon cancer cells. Further studies on responsiveness to glucagon may help elucidate mechanisms of oncogenesis and suggest new therapeutic protocols for patients with colorectal cancer.

Adenocarcinoma↗
PubMed1979

Combination chemotherapy for soft-tissue sarcomas: a phase III study.

A total of 144 patients with advanced sarcomas were entered into a randomized prospective protocol with four treatment arms utilizing different combinations of chemotherapeutic agents. Of these, 120 patients (83%) were judged acceptable. Treatment 1: actinomycin-D (Act-D), 0.01 mg/kg IV, days 1--5; phenylalanine mustard (L-PAM), 4 mg PO, days 1--10 every six weeks. Treatment 2: Act-D, 0.01 mg/kg IV, days 1--5; L-PAM, 4 mg PO, days 1--10; vincristine, 1 mg IV, days 1, 8, 15, 22, 29, 36, repeat every six weeks. Treatment 3: Act-D, 0.01 mg/kg IV, days 1--5; L-PAM, 4 mg PO, DAYS 1--10; NSC-1026, 200 mg/kg IV, days 1--6. Treatment 4: Adriamycin, 0.4 mg/kg IV, days 1, 2, 3, 8, 9, 10, then 2XWK starting day 15 (max. 1,200 mg). There was a provision that upon progression of the disease in the first three treatment regimens, patients would be crossed over to Treatment 4. Responses were as follows: 1 - Partial Response (PR) 1/25; No Change (NC) 9/25 (36%). gF2 - NC 17/26 (65%). 3 - NC 13/25 (52%). 4 - Complete Response (CR) 1/41; PR 6/41; (15%); NC 27/41 (66%). Clearly Treatment 4 was the best arm, with a 17% response rate and an initial progression rate of 17%. The only other response was a partial in 1. The difference is statistically significant (H = 17.247, P = 0.0006). If the responders to Adriamycin were analyzed without crossovers, the response rate would be 22% (6/27). (H = 14.079, P = 0.003). Median times to progression were 12.5, 8.7 weeks for 1 and 2, and 5 weeks for 3 and 4. There was no significant difference in the median survival times among the four treatment arms. It appears that Adriamycin as a single drug is superior to the drug combinations and would probably be even more effective used in combination with known active agents.

Antineoplastic Agents↗
PubMed1979

5-FU versus combination therapy with tubercidin, streptozotocin, and 5-FU in the treatment of pancreatic carcinomas: COG protocol 7230.

From May 1972 until May 1976, 105 patients were entered on Central Oncology Group protocol 7230 to compare the combination of streptozotocin, tubercidin, and 5-fluorouracil (5-FU) versus 5-FU alone in the treatment of adenocarcinoma and islet cell carcinoma of the pancreas. Twenty-nine were not evaluable. Thirty-six evaluable cases received 5-FU, and 40 received the combination, with no significant difference in time to progression or survival. Toxicity in the two regimens was somewhat different but was essentially similar in magnitude. Results indicate no benefit in the treatment of adenocarcinoma of the pancreas with the three-drug combination over 5-FU alone. All of the islet cell tumor patients benefited from the combination by response or arrest of progression of disease. Further study should be directed toward the use of this combination in the treatment of functioning and non-functioning islet cell tumors of the pancreas.

Adenocarcinoma↗
PubMed1979

Results of a prospective randomized study of hepatic artery infusion with 5-fluorouracil versus intravenous 5-fluorouracil in patients with hepatic metastases from colorectal cancer: A Central Oncology Group study.

In a controlled, prospectively randomized trial, 74 patients with hepatic metastases from colorectal cancer were randomized to either intra-arterial hepatic artery infusion with 5-fluorouracil (5-FU) or systemic chemotherapy with 5-FU. In 61 acceptable patients, there was no significant difference in terms of response rate, time to progression, duration of the response, and survival rate. Though the response rate for the intra-arterial infusion arm was slightly higher than for the systemic arm, the difference was not significant, and the intra-arterial infusion arm was associated with a greater incidence of nausea, vomiting, diarrhea, in addition to complications of femoral-arterial thrombosis, bleeding, and infection at the catheter site not seen in patients treated by systemic chemotherapy. Patients with an objective response to chemotherapy on either treatment arm survived twice as long as the nonresponders. Long-term survival in one patient, 77 months, can occasionally be achieved in patients with hepatic metastases.

Adenocarcinoma↗