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Biomedical subjects

A B Cruz

Publications and source records attributed to A B Cruz.

At least 37 records · Page 2Linked to original sources
PubMed1990

Carcinoma of the pancreas: a retrospective review.

Eighty-five patients with adenocarcinoma of the pancreas were reviewed in order to evaluate the efficacy of our methods of diagnosis and treatment. The most useful diagnostic test was percutaneous transhepatic cholangiography (PTC) with a diagnostic rate of 96%. Pancreaticoduodenectomy (Whipple procedure) and total pancreatic resection were performed in 13 and 2 patients, respectively. The remaining 50 patients underwent various palliative drainage procedures. Twenty patients did not undergo operation for various reasons. The primary tumor was found in the head of the pancreas in 50 patients (59%), the body in 6 patients (7%), and in the tail in 8 patients (9%). Postoperative complications, including sepsis, bleeding, intra-abdominal abscesses, and anastomotic leaks, occurred in 37% of the patients. There were one operative and 9 postoperative deaths. The average survival for those patients undergoing surgical intervention was 6 months. There were no 5-year survivors.

Adult↗
PubMed1990

Portal infusion of tumor necrosis factor increases mortality in rats.

Tumor necrosis factor (TNF) is a protein found in the serum of mice presensitized with BCG following injection of endotoxin. Although TNF has been shown to cause hemorrhagic necrosis of certain tumors, the marked toxicity of recombinant human TNF has limited the clinical usefulness of this compound. This experiment was designed to determine whether hepatic metabolism would reduce the systemic toxicity of TNF delivered by the portal circulation. Twenty male Fischer rats received a continuous infusion of recombinant human TNF (100 micrograms/kg/day), 10 through a portal venous branch, and 10 through a branch of the inferior vena cava. Control animals received an infusion of carrier solution by the same route. After 7 days the animals were sacrificed and their organs weighed and sectioned. Mortality in the portal TNF group was 100%. The animals followed the clinical pattern seen with lethal TNF injection. Histologic sections revealed significant gastric and small intestinal mucosal injury, pulmonary edema, and acute tubular necrosis. Animals receiving TNF systemically lost more weight per day of infusion than controls, but followed a relatively benign course. Systemically infused animals had evidence of mild pulmonary edema, and a periportal mononuclear infiltrate in the liver, but no obvious renal or gastrointestinal injury. In a second experiment the effect of escalating doses of portal TNF infusion on liver enzymes was assessed. TNF was infused intraportally at 10, 50, or 100 micrograms/kg/day for 3 days. Control animals received a carrier solution. Mortality was dose-related with 100% mortality in animals receiving 100 micrograms/kg/day, and 40% mortality in the 50 micrograms/kg/day group.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1989

Demonstration of anti-bradykinin compounds in callus cultures of Mandevilla velutina.

Calluses from stems and leaves of Mandevilla velutina were grown in culture for 30, 45 and 60 days. Thin-layer chromatography of ethyl acetate extracts of calluses from stems of M. velutina revealed the presence of 6 compounds. Two of them had RF values identical to those of the anti-bradykinin (BK) compounds MV8609 and MV8610 previously isolated from the natural plant. The ethyl acetate extract (20 to 80 micrograms/ml) from stem callus culture antagonized in a concentration-dependent and reversible manner contractions caused by BK (0.1-1000 nM) in the isolated rat uterus. The extracts obtained from calluses cultured for 30, 45 and 60 days were about 79-, 63- and 31-fold more potent, respectively, in antagonizing BK than the crude extract obtained from the rhizome of the plant.

Animals↗
PubMed1988

Needle aspiration biopsy of palpable breast masses.

One hundred fifteen patients underwent needle aspiration biopsy of palpable breast masses prior to open biopsy. Aspirates were obtained by surgical residents, prepared by a cytotechnologist present at the procedure, and evaluated by a single pathologist. Cytologic findings were interpreted as positive or highly suspicious for malignancy, normal or benign, or insufficient. All patients underwent open biopsy. Patients with positive or highly suspicious cytologic findings who preferred partial mastectomy and radiotherapy were offered a segmental mastectomy. No patient was offered total mastectomy based on cytologic findings alone. There were two false-positive and two false-negative results, for a 92 percent sensitivity and 97 percent specificity. The value of needle aspiration biopsy lies in its ability to identify patients at high risk for malignancy. Total mastectomy cannot be recommended based on cytologic findings alone. The setting of a surgical residency program does not adversely affect the reliability of the technique.

Adolescent↗
PubMed1988

Adjuvant therapy in large bowel adenocarcinoma: long-term results of a Southwest Oncology Group Study.

The Southwest Oncology Group (SWOG) colorectal adjuvant study 7510 went through two phases. From 1975 to 1977, 309 patients were randomized to chemotherapy alone or the same chemotherapy plus immunotherapy. From 1977 until 1980, 317 patients were randomized among the same two therapy programs and a control group. With a minimum follow-up in either phase of greater than 7 years, data are now mature. They show no difference in relapse-free survival (RFS) nor overall survival (OS) in either the two-way phase or in the three-way phase. There is no indication, except possibly in one very small subset, that the addition of immunotherapy to chemotherapy provides an improvement in OS or in RFS. Using data from patients accrued after randomization to the control group, we fail to find evidence that either chemotherapy alone or chemoimmunotherapy improves OS or RFS when contrasted to outcomes obtained by patients on the control arm. In fact, we have significant evidence, at the P = .016 level, that chemotherapy does not improve OS by at least 50%; we also have significant evidence, at the P = .011 level, that chemoimmunotherapy will not improve OS by at least 25%. No evidence of efficacy was demonstrated for either treatment regimen, even though enough therapy was given to result in significant toxicities. Acute toxicity was at least moderate, but not fatal, in 75% of patients. Recognizable delayed toxicity included rare cases of fatal renal failure and acute leukemia.

Adenocarcinoma↗
PubMed1988

Blockade of the bradykinin-evoked diphasic response of isolated rat duodenum by the crude extract of and compounds obtained from Mandevilla velutina.

The influence of an aqueous/ethanolic extract of M. velutina (CE) and of two compounds (MV 8608 and MV 8612) purified from the plant on BK-, Ad- and K+-induced responses of the rat duodenum was analyzed in vitro. In preparations precontracted with Ca2+, the CE (1 and 2 mg/ml) markedly inhibited BK-induced relaxation in a dose-dependent manner but was less effective against Ad-induced relaxation. The CE (0.5 mg/ml) also antagonized BK-induced relaxation and contraction of strips bathed in normal medium. The two compounds from M. velutina (10 and 20 micrograms/ml) also promoted a dose-dependent blockade of both responses to BK, only slightly depressing the response to K+.

Animals↗
PubMed1987

Somatostatinoma: a case report and review of the literature.

Somatostatinomas are rare endocrine tumors that were first described in 1977. In addition to the present case report, there have been 31 cases reported in the literature. We have reviewed the literature to integrate the symptoms, physical findings, diagnostic tests, treatment, and length of survival of these patients. Although the symptoms that occurred in the majority of cases were those that are seen in most patients with intra-abdominal neoplasms, symptoms relating to the presence of excess circulating somatostatin--diabetes, maldigestion, and cholelithiasis--were frequently seen. Physical findings and the results of diagnostic tests were usually nonspecific. The majority of the patients underwent radical surgical procedures (Whipple procedure or pancreatic resection). The pancreas was the most frequent site of involvement (21/31 cases), but primaries in the duodenum, ampulla of Vater, cystic duct, and jejunum have been described as well. Metastases were most frequently seen in the liver and lymph nodes. Chemotherapeutic agents were administered to 10 patients, usually as adjuvant therapy, and appear to be useful in treating recurrent and metastatic disease. The one-year survival of these patients is 48%, which is better than that for patients with carcinoma of the pancreas or biliary tree. Therefore, it is important that the diagnosis of somatostinoma be made so that the patient may be treated accordingly and followed by serial somatostatin levels for evidence of metastasis or recurrent disease.

Adenoma, Islet Cell↗
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↗
PubMed1985

Results of a 400-patient carcinoembryonic antigen second-look colorectal cancer study.

Four hundred patients with resectable colon and rectal cancers were operated on by 37 surgeons at 31 institutions. Patients were monitored with carcinoembryonic antigen (CEA) level determinations and clinical examinations. One hundred thirty patients had recurrences, and 75 were reoperated on, with 43 reoperations CEA-directed and 32 clinically directed. Two of 75 died within 1 month after the second operation. Twenty-two second-look patients remain free of disease 5 years after their second operation. The highest resectability of recurrent cancer occurred in patients with a CEA level below 11 ng/ml in whom the CEA level was determined at intervals of 1 to 2 months.

Adenocarcinoma↗
PubMed1985

Upper gastrointestinal bleeding following renal transplantation.

Upper gastrointestinal bleeding has been shown to be a common complication of renal transplantation and one which carries a significant risk of mortality. In a retrospective review of 200 consecutive renal transplants in 194 patients, we found an incidence of only 6 per cent and a mortality rate of 8.3 per cent. Allograft survival in this group of patients was 58 per cent. These results are the product of careful preoperative evaluation, close attention to the patients for early signs of bleeding, and aggressive diagnostic and therapeutic intervention at the first evidence of bleeding. We also report an association of hypercalcemia with post-transplant upper gastrointestinal bleeding, with cessation of bleeding after parathyroidectomy.

Antacids↗
PubMed1984

Operative management of thyroid disease. Technical considerations in a residency training program.

Experience with 294 thyroid operations at Medical Center Hospital as performed by resident housestaff in general surgery has been reported. Operative results were consistent with the morbidity and mortality figures from large reviews. The importance of an active role for surgical housestaff in the operative management of thyroid disease is emphasized. With close supervision and attention to intraoperative identification of the recurrent laryngeal nerves and parathyroid glands, satisfactory results can be achieved.

Adult↗
PubMed1984

Needle aspiration biopsy: role and limitations in surgical decision making.

A total of 464 fine-needle aspiration biopsy specimens in 450 patients was studied. The majority of these aspirates were performed by the pathologist. The technic was 95% sensitive, 99.5% specific, and 97.0% accurate when correlated with histopathology or long-term follow-up. The complication rate was 0.9% and occurred only when needles larger than #22 were used to aspirate lung lesions resulting in pneumothorax. A flow chart for the role of needle biopsy in investigating masses of various organs is presented, together with some illustrative examples. In the current atmosphere of cost-containment, this inexpensive yet fast and accurate technic should play an important role in surgical decision making. However, pathologists and clinicians should be aware of the limitations and should not hesitate in obtaining an open biopsy when necessary, particularly when clinical suspicion for malignancy is not confirmed by the aspiration, in view of the small but significant (4.9%) false-negative rate.

Aged↗
PubMed1983

Relation of number of positive axillary nodes to the prognosis of patients with primary breast cancer. An NSABP update.

The current findings completely affirm the validity of our original observations indicating the appropriateness of grouping primary breast cancer patients into those with negative, 1 to 3, or greater than or equal to 4 positive nodes. Results, however, reveal that there is a risk in combining all patients with greater than or equal to 4 positive nodes into a single group. Since there was a 25% greater disease-free survival and an 18% greater survival in those with 4 to 6 than in those with greater than or equal to 13 positive axillary nodes, such a unification may provide misleading information regarding patient prognosis, as well as the worth of a therapeutic regimen when compared with another from a putatively similar patient population. Of particular interest were findings relating the conditional probability, i.e., the hazard rate, of a treatment failure or death each year during the 5-year period following operation to nodal involvement with tumor. Whereas the hazard rate for those with negative, or 1 to 3 positive nodes, was relatively low and constant, in those with greater than or equal to 4 positive nodes the risk in the early years was much greater, but by the fifth year it was similar to that occurring when 1-3 nodes were involved, and not much different from negative node patients. The same pattern existed whether 4 to 6 or greater than or equal to 13 nodes were positive. When the current findings are considered relative to other factors with predictive import, it is concluded that nodal status still remains the primary prognostic discriminant.

Axilla↗
PubMed1983

The prognostic significance of tumor location and bowel obstruction in Dukes B and C colorectal cancer. Findings from the NSABP clinical trials.

The present study examines the prognostic significance of tumor location and bowel obstruction in Dukes B and C colorectal cancer. Data were obtained from 1021 patients entered into two randomized prospective clinical trials of the NSABP. Tumor location proved to be a strong prognostic discriminant. Lesions located in the left colon demonstrated the most favorable prognosis. Tumors of the rectosigmoid and rectum had the worst prognosis with the relative risk of treatment failure for the latter being over three fold that of the left colon. When the relative risks associated with tumor location were adjusted for nodal imbalances, the left colon continued to demonstrate the most favorable prognosis. The presence of bowel obstruction also strongly influenced the prognostic outcome. Examination of the data without considering tumor location disclosed that patients with bowel obstruction were at greater risk for treatment failure than those without obstruction. The effect of bowel obstruction was influenced by the location of the tumor. The occurrence of bowel obstruction in the right colon was associated with a significantly diminished disease-free survival, whereas obstruction in the left colon demonstrated no such effect. This phenomenon was independent of nodal status and tumor encirclement, the latter two factors proving to be of prognostic significance independent of tumor obstruction. A multivariate analysis in which the covariate effects of sex, age, nodal status, tumor obstruction, encirclement, and tumor location were adjusted underscored the role of tumor location and obstruction as prognostic discriminants. The results indicate that the definition of prognostic factors can identify patient subsets with unique characteristics.

Carcinoma↗
PubMed1983

Prospective clinical trial of a human tumor cloning system.

A prospective clinical trial was performed to evaluate the usefulness of a human tumor cloning system for selecting single-agent chemotherapy for patients with advanced cancers. Six hundred four single-agent trials were performed in the 470 patients whose tumors were submitted for drug sensitivity testing. Only 246 of these 604 trials (41%) could be directed by the cloning system results because of inadequate tumor growth and other difficulties. In these 246 prospective trials, there was a 60% true positive and an 85% true negative rate for predicting for response or lack of response of an individual patient's tumor to the single agent. There was also a relationship between the percentage of decrease in survival of tumor colony-forming units and the probability of a clinical response of the patient's tumor to the same drug used in vivo. Despite these encouraging findings, work to improve tumor growth and additional prospective clinical trials of the system are needed before the system can be recommended for routine clinical use.

Breast Neoplasms↗
PubMed1982

Direct cloning of human breast cancer in soft agar culture.

A human tumor cloning system has been utilized to grow human breast carcinoma. A total of 225 specimens have been placed in culture. One hundred thirty-two were from primary chest cancer specimens and 93 were from metastatic lesions. Of these, 71% of the primary breast carcinomas and 75% of metastases formed greater than or equal to 5 colonies per 500,000 cells plated. Forty-five percent of the primary breast carcinomas and 52% of the metastases formed enough colonies (greater than or equal to 30 colonies per 500,000 cells plated) to perform meaningful in vitro drug testing. Estrogen receptor status did not influence the percentage of tumors which formed colonies in vitro. Histologic and nude mouse studies provided confirmatory evidence the colonies were composed of breast cancer cells. In 176 in vitro chemotherapeutic drug tests, the anticancer agents commonly used clinically for treatment of breast cancer, i.e., Adriamycin, 5-fluorouracil, etc., showed some in vitro activity. This activity was not as dramatic as is seen in the clinic with these conventional agents. Future work should concentrate on improving the number of colonies which form from breast cancer specimens and on prospective use of the system for screening for new agents for the treatment of human breast cancer.

Agar↗