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Biomedical subjects

T R Russell

Publications and source records attributed to T R Russell.

At least 37 records · Page 2Linked to original sources
PubMed1993

Adenocarcinoma of the anal glands. Results of a survey.

Anal gland adenocarcinoma is rare, with information concerning this lesion communicated mostly as case reports. Cases seen by authors, combined with a survey of the membership of The American Society of Colon and Rectal Surgeons, allowed 52 cases with sufficient data for analysis. It became clear from the survey that most colorectal surgeons have not treated this malignancy. Predominant symptoms are anal pain (58 percent), rectal bleeding (40 percent), and the presence of perianal mass (37 percent). Fifty-four percent of patients present with a fistula, the incidence of fistula being significantly higher in males. Metastases, which may be inguinal, pelvic, or hepatic, are present at diagnosis in 13.5 percent of patients. Three-fourths of patients are eventually treated by abdomino-perineal resection (APR). Twelve percent of the patients in this series had an APR after a failed local excision. The conclusions from this study are: 1) if local excision is attempted, it must be complete, and the patient must be followed closely for many years, and 2) APR is needed in most patients for local control, with the role of subsequent radiation therapy and/or chemotherapy not yet defined.

Adenocarcinoma↗
PubMed1992

Appendicitis in acquired immunodeficiency syndrome.

Reports in the surgical literature are few regarding common intra-abdominal disease processes, such as gallstone disease or appendicitis, in patients with AIDS and instead have focused on AIDS-related intra-abdominal diseases that infrequently require surgical intervention unless complicated by bleeding, obstruction, or perforation. A literature review for appendicitis in AIDS patients revealed only 30 well-documented cases drawn from 13 studies, with a 40% perforation rate and frequent delays and errors in diagnosis. A 7-year experience with 28 patients with appendicitis and AIDS from 4 urban San Francisco hospitals is reviewed. There were no perioperative deaths and an 18% postoperative complication rate. Five patients (18%) were found to have normal appendices with other intra-abdominal pathology, and an AIDS-related etiology for appendicitis was discovered in 7 of 23 patients with appendicitis (30%). With the exception of diffuse versus localized abdominal pain, no preoperative symptom or sign was useful in differentiating AIDS-related and non-AIDS-related disease. Aggressive use of ultrasound and abdominal computed tomographic scanning, along with early surgical intervention, is recommended.

AIDS-Related Opportunistic Infections↗
PubMed1991

The impact of liver reductions in pediatric liver transplantation.

Reduced-size liver transplantation (RSLT) in children was introduced to alleviate a shortage of small-organ donors. The impact of RSLT on the waiting time for an organ and on morbidity and mortality was investigated. Between March 25, 1988, and August 11, 1990, 61 hepatic transplantations were performed in 55 children at the Pacific Transplant Institute in San Francisco, Calif. Full-size liver transplantation was performed in 41 cases and RSLT in 20 cases. The overall 30-month actuarial patient and graft survival rates were 89% and 73%, respectively. A comparison between full-size liver transplantation and RSLT showed no difference in patient and graft survival, reoperations, infections, or rejection. Benefits of RSLT were an increase in the donor pool size, a decrease in waiting time for a suitable donor, and a decrease in the rate of arterial thrombosis. The main morbidity of RSLT was an increase in perioperative blood requirement. We conclude that RSLT offers small children with end-stage liver disease a chance for long-term survival.

Actuarial Analysis↗
PubMed1990

Gastrointestinal tuberculosis. Report of four cases.

Gastrointestinal tuberculosis is a rare disease in the United States. Correct identification is often delayed because it is not considered early on in the differential diagnosis. Four patients with gastrointestinal tuberculosis and the symptoms, diagnosis, complications, and treatment of the disease are discussed. Gastrointestinal tuberculosis should be considered in Asian immigrant patients who present with symptoms and signs of inflammatory bowel disease.

Adult↗
PubMed1985

Hemorrhoidal banding. A warning.

Band ligation of symptomatic internal hemorrhoids is a well-established and accepted outpatient procedure. The purpose of this paper is to alert the medical profession to potential complications and death following this procedure. Each of the four patients described in this report experienced pain and inability to urinate following banding. This report does not condemn banding but, rather, focuses on problems associated with a procedure perceived by many to be risk free.

Adult↗
PubMed1985

Cyclic AMP effects on cell-to-cell junctional membrane permeability during adipocyte differentiation of 3T3-L1 fibroblasts.

Mouse 3T3-L1 fibroblast cells, also know as preadipocytes, differentiate in vitro into adipocytes when treated with promoting agents and acquire numerous properties characteristic of mature fat cells. We studied junctional cell-to-cell communication by measuring the incidence of electrical coupling and transfer of carboxy-fluorescein among these cells. When 3T3-L1 cells were induced to differentiate into adipocytes, they lost virtually all cell-cell communication. Preadipocytes that remained nondifferentiated after the treatment maintained normal communication. Loss of communication in the adipocytes invariably coincided with appearance of lipid droplets and not with other phenotypic changes. In the differentiating cells, loss of cell-to-cell communication and lipid accumulation was prevented if dibutyryl cyclic AMP and caffeine were present in the culture medium. Addition of dibutyryl cyclic AMP and caffeine to already differentiated adipocytes resulted in loss of lipid and simultaneously improved junctional permeability. The results demonstrate that in the in vitro 3T3-L1 cell system, (a) cell-to-cell communication and lipid synthesis are intimately related during the adipose conversion and (b) cAMP affects the expression of the two phenotypes.

Adipose Tissue↗
PubMed1984

Purification of beta cells from rat islets by monoclonal antibody-fluorescence flow cytometry.

Fluoresceinated monoclonal antibody plus flow cytometry was used to purify beta cells from mixed pancreatic islet endocrine cell populations. A2B5, a monoclonal antibody to a glycolipid on the surface of cells of neuroendocrine origin, was incubated with single cells dissociated from rat pancreatic islets. Antibody-bound cells were labeled with fluoresceinated goat F(ab')2 antimouse immunoglobulin and highly fluorescent cells were separated from less fluorescent cells on a Coulter EPICS IV cell sorter. Sorted cell populations were analyzed by radioimmunoassay for insulin, glucagon, and somatostatin. The highly fluorescent cell population was enriched sixfold for insulin-containing beta cells, indicating that islet beta cells are relatively enriched in A2B5 antigen and can be partially purified by this method.

Animals↗
PubMed1984

Percutaneous gastrostomy. A new simplified and cost-effective technique.

A refined endoscopically controlled percutaneous tube gastrostomy has been described in detail, and the experience gained in 28 patients has been reported herein. A majority of the patients had severe underlying neurologic disorders, malignancy of the oral pharynx or esophagus or chronic intestinal obstruction due to advanced malignancy. The three groups of patients were analyzed regarding mortality and morbidity. Three minor complications occurred in the entire group, and three in-hospital deaths occurred which were unrelated to the tube. In addition, four other patients died from their underlying disease several months after discharge from the hospital. Analysis of this technique has shown it to be safe, easy to perform, and acceptable to the patients and supporting personnel. A cost analysis showed significant savings when this technique was utilized instead of operative gastrostomy.

Aged↗
PubMed1983

Rectalepidural fistula complicating Crohn's enterocolitis.

A previously unreported complication of a patient with Crohn's enterocolitis and internal fistulation is presented. The patient presented with meningeal signs in the lumbosacral region, fever, and sepsis. Computerized axial tomography revealed air in the epidural space, and a presumptive diagnosis of rectalepidural fistula was made. Surgical management included a diverting end sigmoid colostomy and presacral drainage.

Adult↗
PubMed1983

Ischemic colitis. Comparison of surgical and nonoperative management.

A retrospective review of 18 patients with ischemic colitis is presented. Patients who developed ischemic colitis following abdominal aortic surgery were excluded, as were patients in whom the diagnosis was made on clinical grounds only. The diagnosis was confirmed in each case either by proctosigmoidoscopy, colonoscopy, barium enema, surgery, or autopsy. Nine patients were treated surgically and nine nonoperatively. The mortality in the operated group was 55 per cent, compared to a 45 per cent mortality in the nonsurgically managed patients. Successful treatment of ischemic colitis depends on early recognition, which requires a high index of suspicion for this common but frequently unrecognized entity.

Adult↗
PubMed1983

Mitosis of contact-inhibited 3T3 preadipocytes precedes chemically induced differentiation into adipocytes.

We studied the conversion of 3T3 cells into adipocytes in vitro after pulsed exposure of confluent, nongrowing cultures to various combinations of the "triggering" agents, methylisobutylxanthine, dexamethasone, and fetal calf serum. Conversion of nongrowing 3T3 preadipocytes into adipocytes takes place after the cells have been stimulated to undergo one round of cell division. Maximal cell division and cytodifferentiation occur only when all three triggering agents are present.

1-Methyl-3-isobutylxanthine↗
PubMed1980

Inhibition of adipose conversion in 3T3-L2 cells by retinoic acid.

The role of retinoic acid in modulating the differentiation of 3T3-L2 fibroblasts into adipocytes has been examined. Results indicate that the retinoid is capable of effectively inhibiting the degree of adipose conversion which is brought about by treatment of preadipocytes with 1-methyl-3-isobutylxanthine plus dexamethasone. MOrphological and enzymatic (fatty acid synthetase activity) expression of the adipose phenotype are both inhibited more than 90% by 10(-6) M retinoic acid. The inhibition is concentration dependent with retinoic acid must be administered simultaneously with the triggering agents to be effective. Exposure of nongrowing preadipocytes to retinoic acid does not alter the ability o the cells to differentiate in response to a subsequent treatment with methylisobutylxanthine plus dexamethasone. Further, the inhibition is reversible. Cultures i which methylisobutylxanthine plus dexamethasone triggered differentiation has been blocked by addition of retinoic acid (10(-6) M) will readily undergo adipose conversion in response to a second treatment with methylisobutylxanthine plus dexamethasone in the absence of the retinoid. Similar inhibition of differentiation was found when cultures were treated with drugs in medium supplemented with either newborn calf serum or fetal calf serum. However, the extent to which methylisobutylxanthine plus dexamethasone are able to promote differentiation in these cells is considerably greater in medium containing fetal calf serum.

1-Methyl-3-isobutylxanthine↗
PubMed1980

Acquisition of an insulin-sensitive activity of adenosine-3',5'-monophosphate phosphodiesterase during adipose conversion of 3T3-L2 cells.

Mouse 3T3-L2 fibroblasts differentiate when cultured and express a new phenotype which is characteristic of adipose cells. One aspect of this differentiation is the acquisition of hormone sensitivities typical of adipocytes. The sensitivity of adenosine-3',5'-monophosphate (cAMP) phosphodiesterase to brief insulin treatment in 3T3-L2 cells at various stages of adipose conversion was examined. The capacity to increase the activity of a low-Km form of the enzyme in response to acute insulin exposure is a property which is acquired as the cells begin to express the adipose phenotype. Enzyme activity in preadipocytes is not affected by inslin, nor is there an effect in the non-differentiating 3T3-C2 line under any of the conditions tested. Since insulin receptors and cAMP phosphodiesterase are both present in the preadipocytes, one result of this cytodifferentiation is to effectively couple receptors to the enzyme activity. Insulin-sensitive cAMP phosphodiesterase in 3T3-L2 adipocytes is characterized by a 40-50% increase in enzyme activity during insulin treatment when determined at 0.1 microM cAMP. This activation results from an increase in the apparent V of the enzyme and does not involve a change in enzyme-substrate affinity. Maximal stimulation is seen within 2-5 min and is sustained for at least 45 min when high levels of insulin (850 nM) are used. Lower concentrations of insulin (1.7 nM) also bring about rapid activation, although the activation is not completely sustained during longer incubations. Stimulated activity falls off to about 60% of peak values by 30 min. Re-addition of insulin after 30 min raises enzyme activity back to the maximal level. Further, the insulin response is completely reversible in that the insulin-sensitive cAMP phosphodiesterase activity disappears within 10 min after removal of insulin from the cultures.

1-Methyl-3-isobutylxanthine↗
PubMed1979

Increase in fatty acid synthetase content of 3T3-L cells undergoing spontaneous and chemically induced differentiation to adipocytes.

3T3-L fibroblasts differentiate into adipose cells when maintained in a non-growing state. The specific activity of fatty acid synthetase of differentiated cells was 25--30-fold higher than that present in 3T3-L fibroblasts or in 3T3-C2 cells that possess an extremely low incidence of differentiation to adipocytes. The results of immunochemical analysis indicate that the increased specific activity of fatty acid synthetase in the differentiated cells is due to an increase in the cellular content of this enzyme. The rate of conversion of adipose cells was accelerated by brief exposure of confluent non-growing cultures of 3T3-L cells to 3-isobutyl-1-methylxanthine. This was accompanied by an increase in the specificity activity of fatty acid synthetase, which was also shown to be due to an increase in the cellular content of this enzyme. The continuous presence of 3-isobutyl-1-methylxanthine in the culture medium was not required to elicit the morphological and biochemical changes in 3T3-L cells that occurred many days after the removal of the inducer but earlier than the onset of spontanous differentiation.

1-Methyl-3-isobutylxanthine↗
PubMed1979

Differentiation of 3T3-L2 fibroblasts into adipose cells in bromodeoxyuridine-suppressed cultures.

Growth of 3T3-L2 fibroblasts in medium containing 5-bromo-2'-deoxyuridine prevents the spontaneous cytodifferentiation of these cells into adipose cells. Treatment of bromodeoxyuridine-suppressed cultures at confluence with 1-methyl-3-isobutylxanthine, a promoter of the adipose conversion, results in differentiation of the fibroblasts into adipose cells but the extent of the conversion is less than that seen in cultures not treated with bromodeoxyuridine. 1-Methyl-3-isobutylxanthine appears to function without altering the amount of bromodeoxyuridine present in DNA.

1-Methyl-3-isobutylxanthine↗