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Biomedical subjects

S G Economou

Publications and source records attributed to S G Economou.

At least 37 records · Page 2Linked to original sources
PubMed1987

New method for cardiac transplantation.

Rat cardiac transplantation into the femoral region has several advantages compared to cardiac transplantation into the peritoneal cavity. These advantages include increased speed, decreased hypothermia of the recipient, and easier-access palpation. However, there is a major discrepancy in the size of the donor and recipient vessels. The donor aorta is two to three times larger than the recipient's femoral artery and thus could be a contraindication to the transplant. To circumvent this problem, we anastomosed the donor's aorta with the recipient's femoral artery by an end-in-end technique whereas the donor's pulmonary artery was anastomosed by conventional end-to-end technique with the recipient's femoral vein. The excess wall of the donor's vessel was plicated on a slant for each anastomosis. Our results compare favorably to those of techniques established previously. We suggest that this new method of cardiac transplantation will be of great value in the study of immunological events involved in graft rejection.

Anastomosis, Surgical↗
PubMed1987

Bone scanning in pregnant patients with breast carcinoma.

Radionuclide scanning is usually contraindicated in pregnancy because of the danger of fetal radiation exposure. Radionuclide bone scanning with Tc-99m MDP is a sensitive indicator of early osseous metastases in breast cancer. Three cases of breast cancer during pregnancy are reported; modified bone scanning was utilized for staging and decision analysis. Modifications of bone scanning techniques to minimize fetal radiation exposure and fetal dosimetry calculations are described.

Abdomen↗
PubMed1987

Extension of survival of rat parathyroid allografts by depletion of Ia donor cells plus preoperative cyclosporine.

Methods that avoid chronic immunosuppression of transplant recipients must be developed to eliminate the various risk factors associated with such treatment (e.g., increased infections and malignancies). Pretransplant treatment of the graft with anti-Ia serum plus complement to eliminate "passenger cells" is one such method. An alternative approach is short-term treatment of the recipients with cyclosporine (CsA). In this study, parathyroid glands from Lewis X Brown Norway rats were cultured for one week at 37 degrees C and treated with anti-Ia and complement. Treated glands were transplanted into parathyroidectomized, hypocalcemic Wistar-Furth recipients that had received 30 mg/kg of CsA once a day for the three days prior to transplant. At 1 year posttransplant, 67% of the recipients had functional parathyroid allografts. Control rats (no CsA; fresh, untreated glands) rejected their grafts within 28 days. Controls given three days of CsA and transplanted with fresh, untreated glands all had functional grafts for greater than 56 days (median survival: 80.5 days). Prolongation of allograft survival with short-term, preoperative CsA demonstrates the efficacy of immunosuppression given only at the time of antigen presentation. This course of CsA allowed for indefinite graft survival when the recipient received a graft previously cultured and treated with Ia antiserum. These results are encouraging and should be evaluated further to determine whether similar approaches will be useful in human transplants.

Animals↗
PubMed1986

Indefinite survival of rat parathyroid allografts without postoperative immunosuppression.

Methods that avoid long-term immunosuppression must be developed for human parathyroid allotransplantation to be feasible. Pretransplant treatment of the graft to eliminate passenger cells is one such method. An alternative approach is short-term treatment of the recipients with cyclosporine (CsA). In this study, parathyroid glands from Lewis X Brown Norway rats were cultured for 1 week and treated with antiserum directed against class II major histocompatibility complex antigens. Treated glands were transplanted into hypocalcemic Wistar-Furth recipients that previously received 30 mg/kg of CsA once a day for 3 days before transplantation. At 280 days after transplantation, 67% of the recipients had functional parathyroid allografts. Control rats (no CsA; fresh, untreated glands) rejected these grafts within 28 days. Control rats given 3 days of CsA and transplanted with fresh, untreated glands had functional grafts for greater than 56 days (median survival, 80.5 days). Prolongation of allograft survival with short-term, preoperative CsA demonstrates the efficacy of immunosuppression given at the time of antigen presentation. This course of CsA is even more effective when the recipient receives a graft whose passenger cells are eliminated.

Animals↗
PubMed1986

The role of ultrasonography in the evaluation of primary hyperparathyroidism.

Ultrasonography was used preoperatively in 21 patients with primary hyperparathyroidism in an effort to locate enlarged parathyroid glands. It indicated the presence of a solitary mass compatible with a parathyroid adenoma in 14 patients. At operation, adenomas were found at the location indicated by ultrasonography in 13 of the 14 patients (93 per cent). In seven patients, ultrasonography failed to reveal evidence of a mass of the parathyroid gland. At operation, three had diffuse parathyroid hyperplasia and four had a solitary adenoma. Of the four patients with adenomas undetected by ultrasonography, one patient had an adenoma which had undergone infarction and three had coexisting nodular thyroid gland disease. We concluded that ultrasonography is valuable in the preoperative assessment of patients with primary hyperparathyroidism. This is especially so in the absence of coexisting nodular thyroid gland disease. When positive, ultrasonography accurately locates adenomas, and when negative, it strongly suggests the presence of hyperplasia. This may have clinical application in limiting the extent of dissection and, thereby, reducing the morbidity of parathyroid gland exploration.

Adenoma↗
PubMed1986

Megestrol acetate: first-line therapy for advanced breast cancer.

Megestrol acetate as initial hormonal therapy produced a 40% objective response rate in 53 patients with advanced breast cancer; another 26% achieved stable disease. For 19 patients with visceral-dominant disease, the response rate was 42%. To investigate the effect of the order of sequential hormonal therapy, records of 66 patients treated with tamoxifen before megestrol acetate or with megestrol acetate before tamoxifen were reviewed retrospectively. Of the 24 patients who were given megestrol acetate first, nine (38%) had objective response to primary therapy, and four (17%) to secondary therapy. Among the 42 patients treated with tamoxifen first, there were nine (21%) objective responses to primary therapy and eight (19%) responses to secondary therapy. Results show that megestrol acetate is effective first-line hormonal therapy for advanced breast cancer. Megestrol acetate can be used as primary hormonal therapy and tamoxifen as secondary hormonal therapy, as an alternative to the more usual reverse order. One may also consider megestrol acetate for some advanced breast cancer patients with visceral-dominant disease.

Antineoplastic Agents↗
PubMed1985

Qualitative analysis of Coomassie-blue-stained proteins from normal prostate, benign prostatic hypertrophy, or adenocarcinoma of the prostate, separated by two-dimensional protein electrophoresis.

Samples from nine normal prostates (N), ten benign hypertrophic prostates (BPH), and eight adenocarcinomas of the prostate (ACP), obtained from the National Prostatic Cancer Project were analyzed by two-dimensional (2D)-protein electrophoresis. Qualitative analysis of Coomassie-blue-stained acidic proteins between pI 3.5 and 6.8 yielded these results: The total number of enumerated proteins was 136 (N), 107 (BPH), and 147 (ACP). Ninety-two denoted proteins were deemed common to the three kinds of samples, three were considered present in N and BPH, 7 in BPH and ACP, and 28 in N and ACP. Thirteen, five, and 20 proteins were detected only in N, BPH, or ACP. These proteins cannot be considered "unique" to their respective samples, since amounts of protein that do not exceed the minimum sensitivity of the dye may be present in the other samples. The similarity in the patterns of proteins from these three types of prostate samples is consistent with the following hypothesis: The distribution of proteins from histologically ambiguous prostate samples will correlate more closely with these protein profiles than with those associated with cancers originating from other organs.

Adenocarcinoma↗
PubMed1985

Continuous epidural infusion for analgesia after major abdominal operations: a randomized, prospective, double-blind study.

We performed a prospective, randomized, double-blind study of continuous epidural analgesia for 72 hours after major abdominal procedures. Patients were randomly assigned to one of five treatment groups: epidural morphine, epidural bupivacaine, a combination of morphine and bupivacaine, epidural saline solution, and no epidural catheter. All patients received supplemental morphine sulfate or meperidine hydrochloride, intramuscularly or intravenously, as needed. Epidural infusion was begun at 2 to 4 ml/hr, depending on age and height, with two increments of 1 ml/hr allowed if pain relief was insufficient. All pain management decisions were made by nurses, who also monitored epidural function. Performance was measured four ways: pain as measured at regular intervals in the 72-hour period with a visual analog, pain as measured after 72 hours with the McGill Pain Questionnaire, amount of supplemental narcotics needed, and recovery of respiratory function and ambulation as percent of preoperative levels. The group that received the combination of morphine and bupivacaine did best on all measures; in most instances the difference between the results seen with the combination regimen and those seen with saline solution or no catheter were significant at the 0.05 level. With the exception of pruritus, complications were evenly distributed among all treatment groups, including noncatheterized controls. We conclude that epidural analgesia with the combination of morphine and bupivacaine is safe, is easily managed, and gives pain relief superior to that provided by traditional, systemic administration of narcotics.

Abdomen↗
PubMed1985

Pheochromocytoma: operative strategy.

We studied 28 patients who had undergone 30 operations for pheochromocytoma since 1964. The tumor types included bilateral, extra-adrenal, malignant, recurrent, and multiple endocrine neoplasia, with 20 tumors confined to the adrenal gland. The preoperative studies used to localize the tumor included ultrasonography, intravenous urography, angiography, and computed tomography. Patients underwent exploratory operations via flank, subcostal, bilateral subcostal, midline, or thoracoabdominal approaches. In one case, that of a recurrence after bilateral adrenalectomy, surgical exploration discovered a tumor that had not been localized during the preoperative workup. Two patients underwent splenectomy because of injury incurred during operative exploration. Our experience suggests that preoperative localization is highly reliable, and therefore the benefits of extensive surgical exploration may be outweighed by its risks. We believe that with the exception of tumors that occur in association with childhood or pregnancy, multiple endocrine neoplastic syndromes, or recurrent disease, a direct approach to the tumor, possibly via the flank, is justified. Our results suggest that exploration of the contralateral adrenal or periaortic area is not so important as to be worth jeopardizing the spleen or other organs by a complex or extensive dissection.

Adolescent↗
PubMed1984

A ten year experience with hepatic resection.

The results of our experience have demonstrated that patients who undergo hepatic resection for primary or metastatic carcinomas have survival rates considerably higher than those reported in the literature for patients who do not undergo resection. Morbidity rates as well as survival rates among the patients we studied lie within the reported values of the major institutions. It is certainly clear that, within the past five years, metastatic disease to the liver from a primary carcinoma of the colon and rectum has become a treatable disease. We, therefore, advocate the aggressive approach to carcinoma of the liver and look forward to further advancement in the treatment of this disease.

Actuarial Analysis↗
PubMed1983

The distribution of acidic coomassie blue-stained proteins from uninvolved human liver, hepatoma, normal colon, primary colon cancer, and colon metastases to the liver, determined by two-dimensional protein electrophoresis.

The distribution of Coomassie blue-stained proteins from uninvolved regions of 4 human livers, from 1 hepatocellular carcinoma, and from 4 samples each of uninvolved colon, primary adenocarcinoma of the colon, and colon cancer metastatic to the liver was analyzed by two-dimensional protein electrophoresis. From a comparison of acidic proteins between pI 3.5 and 6.5, we conclude (1) that the majority (66 of 82) of denoted acidic proteins from 4 normal liver samples were represented in the hepatocellular carcinoma. Fifty-one of 58 proteins denoted in the 4 colon samples were detected in each of the 4 primary colon cancers; (2) that the "normograms" of proteins from normal colon and normal liver differed in many details, and their dissimilar patterns identified the source of the sample; (3) that hepatoma and primary adenocarcinoma of the colon were easily distinguished by their distribution of proteins; (4) that colon cancer metastatic to the liver contained a majority (50/58) of acidic proteins enumerated in primary colon cancer. These results indicate that uninvolved liver and colon and their primary or secondary cancers can be identified by their distribution of electrophoresed acidic proteins.

Adenocarcinoma↗
PubMed1983

Provisional "normograms" for identifying adenocarcinomas of the prostate or colon and hepatocellular carcinoma derived from their distribution of proteins separated by two-dimensional electrophoresis.

The distribution of proteins in samples from 8 prostate and 4 colon adenocarcinomas and 1 hepatoma was analyzed by 2-dimensional protein electrophoresis. Composite "normograms" based upon their distribution of proteins were developed from these patterns. Particular attention was paid to acidic proteins between pI 3.5 and 5.9. Of 161 proteins enumerated, 23 of the first 135 were present in prostate cancers, compared with 68 in colon cancer and 85 in the hepatoma. The 26 proteins denoted from nos. 135 to 161 were prostate associated, and none was evident in the colon or hepatoma samples. Twenty-seven prostate, 20 colon, and 48 liver cancer proteins were "unique" to each of the 3 cancers, respectively. The patterns of protein associated with each type of cancer were so dissimilar that with this technique no difficulty should be experienced in distinguishing these carcinomas originating from 3 different types of "stem" cells without obligatory recourse to microscopy.

Adenocarcinoma↗
PubMed1981

Radiation carcinogenesis in man: new primary neoplasms in fields of prior therapeutic radiation.

Nine patients are presented in whom new malignant neoplasms developed in fields of prior irradiation. The prior irradiation had been administered to these patients for previously confirmed cancers, lesions suspected of being cancer (but never confirmed as such), and for non-neoplastic disorders. Each of these cases is relatively unique and several present the first association between prior radiation therapy and the subsequent neoplasm or neoplasms which developed.

Adolescent↗
PubMed1981

Two-dimensional protein electrophoresis and the identification of histologically indeterminate human cancers.

It is proposed to identify histologically indeterminate human cancers by comparing their qualitative content of stained proteins, separated by two-dimensional electrophoresis, with patterns of proteins from a series of identified human cancers of comparable or different stem cell origin. The hypothesis to be tested is that in cancer, biochemical ontogeny, reflected in the distribution of cellular and tissue proteins, will recapitulate phylogeny, albeit in a manner less organized than normal. Patterns of protein from cancer cells, whether histologically identified or not but originating from embryologically similar stem cells, are expected to exhibit greater homology, compared with protein profiles of cancer cells derived from stem cells of different embryologic origin. Normal or cancer cell proteins common or unique to one or more cell sources can be identified, and subsets of proteins that characterize cancer cells of specific stem cell origin identified. There are reasons to believe that cancer cells rarely, if ever express properties inconsistent with the basic cellular commitment of their stem cell of origin. Photo-optical scanning and computer-assisted analysis will greatly facilitate collating the many hundreds of discrete proteins, among which those used to characterize different cancer cells are to be found.

Electrophoresis, Polyacrylamide Gel↗