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Biomedical subjects

R A Forse

Publications and source records attributed to R A Forse.

At least 19 recordsLinked to original sources

The effect of dietary polyunsaturated fatty acids (PUFA) on acute rejection and cardiac allograft blood flow in rats.

For six weeks, recipient (Lewis RT11) and donor rats (LBNF11/n) were fed three diets that varied only in their lipid content. Diet A (MO) contained 19.5% menhaden oil and 0.5% safflower oil and was rich in omega 3 PUFA; diet B (SO) was 20% safflower oil rich in omega 6 PUFA; and diet C (BT) was 20% beef tallow rich in omega 9 monounsaturated fatty acids and saturated fat. In the first set of graft survival studies a group fed laboratory chow was included (CHOW). Heterotopic cardiac transplantation from donor to recipient animals was performed after the six-week feeding period. The effect of these diets on cardiac allograft survival, mixed lymphocyte response, and blood flow in the rejecting grafts was investigated. The median graft survival in days was significantly prolonged in the rats maintained on either MO (12 days) or SO (14.5 days) compared with the BT (8 days)-or lab chow (7.5 days)-fed animals (P < 0.05). Cyclosporine (CsA) administered at subtherapeutic levels further increased the differences between the PUFA-fed animals and the BT-fed group. The myocardial blood flow of the rejecting allografts was measured using an 85Sr-labeled microsphere technique on the fifth posttransplant day. Flow was greatest in the MO-fed group, and both MO and SO groups had significantly higher myocardial blood flow than BT-fed rats (P < 0.05) or those bearing isografts. The allogenic mixed lymphocyte responses of peripheral blood mononuclear cells (PBMC) and splenic lymphocytes were suppressed in MO- and SO-fed groups compared with BT-fed animals. The immunosuppressive effect of dietary PUFA warrants further investigation, and their use as a possible adjunctive treatment in organ transplantation should be considered.

Acute Disease

Effect of membrane free fatty acid alterations on the adhesion of human colorectal carcinoma cells to liver macrophages and extracellular matrix proteins.

Epidemiologic studies have linked diets high in animal fat with colon carcinogenesis. A number of animal tumor models have shown that diets rich in omega-3 fatty acids inhibit colon carcinogenesis while diets rich in omega-6 fatty acids promote tumor growth. This study examines whether modification of the membrane fatty acid composition of both moderately (CX-1) and poorly differentiated (MIP-101 and Clone A) human colorectal carcinoma cells alters their interaction with Kupffer cells and extracellular matrix proteins (collagen type IV, fibronectin and laminin). The cells were treated with 15-16 micrograms/ml of docosahexanoic acid (22:6, omega 3) or linoleic acid (18:2,omega 6). Gas chromatography showed significant alterations in the membrane fatty acid composition of the human colorectal cancer cell lines. Binding assays were performed by measuring adherence of 51Cr-labelled tumor cells to Kupffer cell monolayers or to immobilized proteins. Omega-3 treatment significantly decreased the Kupffer cell binding of only the CX-1 line while omega-6 treatment decreased binding of all three cell lines. In contrast both omega-3 and omega-6 treatment of MIP-101 cells decreased binding to the extracellular matrix proteins with the omega-6 effect being more pronounced. These results indicate that the binding characteristics of the colon cancer cells to both Kupffer cells and extracellular matrix proteins may be determined in part by the membrane fatty acid composition. Decreased adherence to extracellular matrix proteins may lead to increased cell motility and invasiveness. Since Kupffer cell binding precedes tumor cell phagocytosis and killing, decreased binding may improve tumor cell survival.

Animals

Lung preservation threshold in a compromised septic lung injury model.

BACKGROUND: Discrepancy between clinical and research works in lung transplantation could be due to differences between compromised clinical donor lungs and intact research lungs. The purpose of this laboratory study was to produce compromised lungs to compare with normal ones. METHODS: Sprague-Dawley rats were continuously infused with lipopolysaccharide (5 mg/kg) for 24 hours before organ harvest. Lungs were stored in University of Wisconsin solution at 4 degrees C for the following period: group 1: intact lungs, no storage (n = 12); group 2: septic lungs, no storage (n = 6); group 3: septic lungs for 6 hours (n = 5); and group 4: septic lungs for 12 hours (n = 5). All lungs were reperfused for 2 hours with venous blood using an isolated, pulsatile perfused lung system. RESULTS: Experimental variables were comparable between groups 1, 2, and 3. All septic lungs stored for 12 hours (group 4) failed within 1 hour of perfusion. CONCLUSIONS: These results indicate that compromised lungs with septic injury functioned at near control levels after 6 hours of preservation. Six hours may be a safe limit for human donor lungs, all of which are compromised in some way by the time of harvest.

Animals

The role of gastric surgery in the multidisciplinary management of severe obesity.

Severe obesity affects the health and quality of life of 4 million Americans. The major cost of treating severe obesity and its associated comorbidities of hypertension, diabetes, cardiovascular disease, pulmonary insufficiency, cancer, and degenerative arthritis as well as the poor long-term results of medical, drug, and behavioral therapy has increased the numbers of patients being referred for surgical treatment. Gastric bypass and vertical banded gastroplasty are the two procedures recommended for severely obese patients. These operations currently have low morbidity and mortality. Surgery should be considered adjuvant therapy and must be part of a multidisciplinary approach. The significant long-term weight control resulting from the surgical therapy is associated with improvement and, often, resolution of comorbidities, including diabetes, hypertension, hyperlipidemia, and pulmonary insufficiency.

Combined Modality Therapy

An educational intervention in the surgical intensive care unit to improve ethical decisions.

BACKGROUND: The objective of this study was to determine whether an educational intervention on medical ethics offered during a surgical intensive care unit (SICU) rotation could effect meaningful change in a tertiary SICU. METHODS: A case-based education program was presented weekly to the surgical residents during their SICU rotation. Cases for study were designed to deal with specific ethical issues common to the SICU. Cases were studied with the residents in a group facilitated by a SICU attending physician and a nursing director. The effect of the course was monitored by case review and by the length of stay (LOS) assessment for patients who died in the SICU during 1990, the base year, through 1993. RESULTS: Discussions of an ethical nature occurred more regularly and earlier during these 4 years as determined by case reviews. For patients who died after being in the SICU a minimum of more than 30 days, a marked decrease occurred in the SICU LOS from 27.8 +/- 3.7 days in 1990 to 15.7 +/- 2.4 days in 1993 (p < 0.05). The number of deaths per year and the average acuity measured by the diagnosis related group score were similar during the 4 years. The LOS in the hospital for dying patients from non-SICU services remained similar during the same time frame. These changes resulted in the dying patients using 1003 SICU days in 1993, down from the 2028 days used in 1990 (p < 0.05). CONCLUSIONS: We conclude that through offering a clinical ethics program during the SICU portion of the residency training, residents increased knowledge and skill in addressing and integrating practical ethical issues into their surgical resident practice. In addition, patient care directly improved with an associated reduced SICU LOS and reduced cost.

Critical Care

Effects of prostaglandin E2, cholera toxin and 8-bromo-cyclic AMP on lipopolysaccharide-induced gene expression of cytokines in human macrophages.

Prostaglandin E2 (PGE2) appears to regulate macrophage cytokine production through the stimulatory GTP-binding protein (Gs protein)-mediated cyclic AMP (cAMP)-dependent transmembrane signal transduction pathway. In this study, we used PGE2, cholera toxin (CT; a direct G alpha s protein stimulator) and 8-bromo-cAMP (a membrane permeable cAMP analogue) to stimulate this pathway, and investigated their influence on cytokine gene expression in lipopolysaccharide (LPS)-activated human macrophages. The mRNA expression for interleukin-1 alpha (IL-1 alpha), IL-1 beta, tumour necrosis factor-alpha (TNF-alpha), IL-6 and IL-8 were determined employing reverse transcription polymerase chain reaction (RT-PCR) using specific primers. We demonstrated that PGE2, CT and 8-bromo-cAMP inhibited the LPS-induced gene activation of TNF-alpha and IL-1 alpha, and had no effect on the gene activation of IL-1 beta and IL-8. Further, our data indicate that PGE2 suppressed the gene activation of IL-6 following LPS stimulation, but neither CT nor 8-bromo-cAMP had an effect. These data suggest that PGE2 alters LPS-stimulated gene activation of only some of the early macrophage cytokines, and does so either by a Gs transmembrane cAMP-dependent or an independent system.

8-Bromo Cyclic Adenosine Monophosphate

Effects of continuous tube feeding of dietary fat emulsions on eicosanoid production and on fatty acid composition during an acute septic shock in rats.

The effects of a short-term (5 days) continuous intragastric tube feeding of diets containing n - 6 polyunsaturated fatty acids (PUFA) from safflower oil (SO) or n - 3 PUFA from menhaden oil (MO) on the production of proinflammatory mediators, and on the number of animals surviving after an intravenous injection of lipopolysaccharide (LPS) were investigated in rats. The phospholipid fatty acid composition of cell membranes from several organs and of plasma were also analyzed. No marked differences in the number of animals surviving or in the production of tumor necrosis factor-alpha were observed between the 2 groups of animals. However, 90 min after LPS exposure the plasma levels of prostaglandin (PG) E2 and 6-keto-PGF1 alpha decreased significantly (40% and 60%, respectively) for the group of rats fed MO diet compared to those fed SO diet (P < 0.05). Following continuous infusion of liquid MO diet, the amount of arachidonic acid (AA) detected was significantly lower in plasma (23%), spleen (43%), lungs (41%), and liver (38%), but was unchanged in the heart tissues. The percent of eicosapentaenoic acid (EPA) incorporated into phospholipids of plasma, spleen, lungs, liver, and heart were 7.6, 4.4, 2.1, 7.2, and 1.1%, respectively. These data indicate that after continuous MO feeding, a significant decrease in the production of proinflammatory eicosanoids was associated with a marked reduction in AA content. Further, these data suggest that nutritional intervention may have a therapeutic potential to ameliorate clinical symptoms due to excessive productions of eicosanoids during acute septic complications.

Animals

A phase II multicenter, double-blind, randomized, placebo-controlled study of three dosages of an immunomodulator (PGG-glucan) in high-risk surgical patients.

OBJECTIVE: To examine the safety and efficacy of multiple doses of PGG-glucan (poly-[1-6]-B-D-glucopyranosyl-[1-3]-B-D-glucopyranose) in high-risk patients undergoing major thoracic or abdominal surgery. DESIGN: An interventional, multicenter, double-blind, randomized, placebo-controlled study. SETTING: Four university-affiliated medical centers. PATIENTS: Sixty-seven high-risk patients undergoing major thoracic or abdominal surgery. INTERVENTION: Patients were randomized in a 1:1:1:1 ratio to receive saline placebo or PGG-glucan at a dose of 0.1 mg/kg, 0.5 mg/kg, and 1.0 mg/kg or 2.0 mg/kg. One dose was administered before surgery and three doses were administered after surgery. MAIN OUTCOME MEASURES: To examine the safety and efficacy of PGG-glucan infusion and to identify potentially important factors for a planned phase III study. RESULTS: A dose-response trend with regard to infection incidence among patients who received PGG-glucan was observed. Serious infections occurred in four patients who received placebo and in three patients who received PGG-glucan at a dose of 0.1 mg/kg. However, only one patient who received PGG-glucan at a high dose had a serious infection. The incidence and severity of adverse events was comparable in all groups. CONCLUSIONS: PGG-glucan was generally safe and well tolerated, may decrease postoperative infection rates, and warrants further investigation in a planned phase III trial.

Adjuvants, Immunologic

Fatty acid composition of lung, macrophage and surfactant phospholipids after short-term enteral feeding with n-3 lipids.

Utilization of enteral feeding modalities may prove clinically relevant for rapid modulation of lung phospholipid polyunsaturated fatty acids (PUFA) that serve as substrates for the formation of vasoactive dienoic eicosanoids. We compared the effects of short-term enteral feeding with formulations enriched with either fish (n-3) or corn (n-6) oil PUFA on the fatty acid composition of rat lung, alveolar macrophage and surfactant phospholipids. The diets were infused continuously for 72 h through a surgically placed gastroduodenal feeding catheter by a syringe pump. The n-3 PUFA derived from the fish oil enriched diet were readily incorporated into the phospholipid membranes of the alveolar macrophages, lung tissue and pulmonary surfactant. The relative percentages of the n-3 PUFA were significantly higher and individual and total n-6 PUFA significantly lower in the macrophage, lung and surfactant phospholipids from the n-3-supplemented rats in comparison with those present in the rats infused enterally with the n-6 diet or untreated, chow-fed rats (baseline). In contrast, there was a significant increase in linoleic acid (18:2n-6) without modification of arachidonic acid (20:4n-6) in the alveolar macrophages, lung tissue and surfactant from rats enterally receiving the n-6 diet relative to levels measured in the rats at baseline. The results suggest that short-term continuous delivery of n-3-enriched enteral preparations can foster rapid modification of membrane phospholipid PUFA composition of lung tissue, alveolar macrophages and lung surfactant.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals

Experience with enteral nutrition in a hospital population of acutely ill patients.

Enteral feeding has unique metabolic and immune advantages. This article describes the successful use of enteral nutrition, alone or in combination with parenteral feeding, in a tertiary-care hospital. Study participants were 89 patients who received enteral feeding during a 6-month period. These critically ill patients (ranging in age from 55 to 71 years) had severity of illness levels of 7 to 25 according to the Acute Physiologic and Chronic Health Evaluation (APACHE II) system and lengths of hospital stay from 27 to 73 days. Mortality was as high as 50% in patients with liver disease (nonmalignant), 35% in patients with cardiothoracic and vascular diseases, and 17% in patients with cancer and other diseases. Despite the severity of illness, patients met their energy and protein intake goals through enteral or combined feeding with total parenteral nutrition. Serial weights (ie, obtained weekly) and serum albumin concentrations did not improve during hospitalization. Complications related to enteral feeding were minimal (< 17% incidence). Differences were noted between survivors and nonsurvivors: nonsurvivors had lower serum albumin concentrations at the time of admission, had longer hospitalizations, and required total parenteral nutrition for more days than the survivors. Nonetheless, even with extremely sick patients, provision of enteral nutrition can be successful using the administration techniques we describe. Enteral nutrition could best be provided by beginning at a slow rate (10 c3/hour), inserting the feeding tube past the pylorus, and feeding according to sensible energy goals (25 kcal/kg of body weight), and using elemental then polymeric formulas.

Acute Disease

Effect of prostaglandin E2 and other intracellular cyclic AMP elevating agents on the mitogen induced mouse splenocyte proliferation in a serum free culture condition.

Prostaglandins (PGs) play an important role in the regulation of the host's immune responses to infection and inflammation. However, the mechanisms through which the PGs regulate immune functions are not well known. In the present study, we investigated the T cell specific mitogen Concanavalin A (Con A) induced mouse splenocyte proliferation in a serum free condition in vitro in the presence of absence of different doses of PGE2, indomethacin, cholera toxin and forskolin. The Con A induced splenocyte proliferative responses were significantly inhibited following the addition of PGE2 and were markedly enhanced in the presence of indomethacin (PG synthase inhibitor). As with PGE2, both cholera toxin and forskolin, which increase intracellular cyclic AMP by activating stimulatory GTP binding protein (Gs protein) and adenylate cyclase respectively, inhibited splenocyte proliferation in a dose dependent manner. These data indicate that PGE2 down regulated mitogen induced splenocyte proliferation and that blocking the production of endogenous PGs potentiated T-cell mitogen response. Further, these findings suggest that PGE2 regulation of splenocyte proliferation is due to increasing intracellular cAMP through G protein transmembrane regulation of adenylate cyclase. This study also provided a defined experimental model to investigate mechanisms of the regulation of cellular function through the exogenous and endogenous mediators such as PGs and their intracellular signal transductions.

Adenylyl Cyclases

Randomized phase I/II trial of a macrophage-specific immunomodulator (PGG-glucan) in high-risk surgical patients.

OBJECTIVE: The safety and efficacy of PGG-glucan in surgical patients at high risk for postoperative infection who underwent major thoracic or abdominal surgery were determined. SUMMARY BACKGROUND DATA: Recent studies have reported a 25% to 27% infectious complication rate in patients undergoing major surgery with an average cost per infected patient of $12,000. The efficacy of PGG-glucan pretreatment in prevention of sepsis has been demonstrated in rodent models for gram-negative and gram-positive bacterial and yeast infections. In vitro studies have demonstrated enhanced microbial killing by monocytes and neutrophils in healthy volunteers after PGG-glucan administration. Thus, PGG-glucan may play a role in decreasing the infectious complication rate in patients undergoing major surgery. METHODS: A double-blind, placebo-controlled randomized study was performed in 34 high-risk patients undergoing major abdominal or thoracic surgery. RESULTS: There were no adverse drug experiences associated with PGG-glucan infusion. Patients who received PGG-glucan had significantly fewer infectious complications (3.4 infections per infected patient vs. 1.4 infections per infected patient, p = 0.05), decreased intravenous antibiotic requirement (10.3 days vs. 0.4 days, p = 0.04) and shorter intensive care unit length of stay (3.3 days vs. 0.1 days, p = 0.03). CONCLUSIONS: PGG-glucan is safe and appears to be effective in the further reduction of the morbidity and cost of major surgery.

Abdomen

Assessment of the cytokine response in liver donors at the time of organ procurement and association with allograft function after orthotopic transplantation.

BACKGROUND: The cause of allograft liver dysfunction after transplantation is unresolved. We tested the hypothesis that human donor liver may be predisposed to ischemia reperfusion injury, and graft dysfunction subsequent to ongoing inflammatory processes during donor hospitalization. STUDY DESIGN: A prospective study of organ donors and transplant recipients of allograft livers from these donors was conducted. Portal venous, inferior vena caval, and superior vena caval blood samples were obtained from 16 clinical organ donors at the time of organ procurement (one to 12 days post-trauma) to characterize the hepatic cytokine and acute phase protein response, to determine whether or not this response resulted from bacterial or endotoxin translocation to the portal circulation, and to assess whether or not transplant outcome was associated with plasma levels of cytokines in the donor. RESULTS: In comparison with systemic blood samples from ten healthy persons, all 16 donors exhibited significantly (p < 0.05) elevated plasma concentrations of interleukin-6, interleukin-8, soluble p55 tumor necrosis factor receptor type I (sTNFr-I), and C-reactive protein. No concentration differences existed among portal venous, inferior vena caval, and superior vena caval blood samples for any cytokine or acute phase protein measured. Donor levels of endotoxin, TNF-alpha, soluble intercellular adhesion molecule-1 (sICAM-1), alpha 1-acid glycoprotein, alpha 1-antitrypsin, and haptoglobin were comparable with those in the healthy persons. Bacterial cultures of portal blood were negative. There was no association between the causation of donor trauma and either donor cytokine response or function and quality of the allograft liver after transplantation. Nor could an association between donor cytokine response and either early allograft function (less than 96 hours) or eventual transplant outcome in the recipients be detected. CONCLUSIONS: These results indicate that, although an ongoing inflammatory response to injury was evident in these donors at the time of organ procurement, there were no apparent adverse effects arising from these inflammatory processes on the function and quality of the donor liver after transplantation. Bacterial translocation does not seem to be a component of the pathogenesis of inflammation. Whether or not the presence of inflammation in the donor alters the metabolic responses of the allograft liver and recipient to transplant operation is unknown.

Acute-Phase Proteins

Rapid modulation of liver-specific transcription factors after injury.

BACKGROUND: The reaction to injury is a well-orchestrated physiologic response involving the coordinated actions of multiple integrated systems. It initially occurs at the molecular level and involves changes in gene transcription. We hypothesized that the molecular mechanisms regulating the generation of an inflammatory response are similar to those orchestrating developmental and tissue-specific expression of proteins and, in the case of the acute phase response, occur through manipulation of liver-specific transcription factors and their binding activity. METHODS: Female BALB/c mice, 7 to 8 weeks old, were subjected to a 15% body surface area burn. Total and polyadenylated liver RNA was isolated, and Northern blot analysis was performed to determine the kinetics of the acute phase proteins albumin and fibrinogen and the liver-specific transcriptional factors CCAAT-enhancer binding protein (C/EBP) alpha, hepatocyte nuclear factor (HNF)-1 alpha, and HNF-4. RESULTS: Induction of the injury response was shown by an increase in fibrinogen messenger RNA levels and a decrease in albumin mRNA levels. The liver-specific transcription factor C/EBP alpha decreased after injury and remained significantly lower than control at 3 hours. HNF-4 mRNA levels fell more slowly, reaching significantly lower levels at 6 hours and remaining suppressed at 34 hours. HNF-1 alpha showed the most rapid fall in mRNA levels at 30 minutes after injury and remained significantly below control levels at 34 hours. CONCLUSIONS: The minimal burn injury model leads to the molecular induction of the acute phase response and induces significant and rapid changes in the liver-specific transcription factors C/EBP alpha, HNF-1 alpha, and HNF-4. These changes may represent a mechanism through which the organ-specific response to injury is mediated.

Animals

Alterations in Ca2+ signal transduction in critically ill surgical patients.

BACKGROUND: Despite improvements in supportive care and pharmacologic therapies, sepsis and related disorders such as systemic inflammatory response syndrome (SIRS) continue to be a leading cause of death in the intensive care unit. We hypothesized that immune dysfunction in this setting may in part be mediated at the level of early signal transduction in monocytes and neutrophils as manifested by changes in intracellular free Ca2+. METHODS: Monocytes and neutrophils were isolated from patients in the intensive care unit who met the criteria for SIRS and from normal volunteers. Cells were loaded with the Ca(2+)-sensitive fluorescent dye Indo-1 and stimulated with the chemotactic peptide f-Met-Leu-Phe (fMLP). Changes in intracellular calcium ion concentration were measured by flow cytometry. RESULTS: Patient monocytes exhibited a decreased Ca2+ flux (43% +/- 3.1%) as compared with normal monocytes (63% +/- 2.5%) (p < 0.05). Patient neutrophils also exhibited a decreased Ca2+ flux in response to fMLP of 58% +/- 3.7% versus 69.3% +/- 3.1% for normal neutrophils (p < 0.05). Incubation of patient cells in normal plasma reversed this dysfunction and showed an improved Ca2+ flux to 60% +/- 2.7% for monocytes and 71% +/- 3.7% for neutrophils (p < 0.05). Conversely, calcium flux was decreased in both normal monocytes (42.3% +/- 3.1%) and normal neutrophils (55.4% +/- 3.8%) after incubation in SIRS patient plasma (p < 0.05). Incubation of normal monocytes and neutrophils in interleukin-1, interleukin-2, interleukin-6, tumor necrosis factor, or lipopolysaccharide did not show a statistically significant alteration in calcium flux in response to fMLP. CONCLUSIONS: Patients with SIRS exhibit alterations in early signal transduction after stimulation with fMLP in monocytes and neutrophils. This effect appears to be mediated by a soluble factor because the defect in SIRS patient cells can be reversed by incubation in normal plasma and normal cells appear to acquire this defect after incubation in patient plasma. Further studies are underway to identify the factor or factors responsible for this functional defect.

Adult

Nutrition support and the human immunodeficiency virus (HIV).

Nutritional support of patients with HIV or acquired immune deficiency syndrome (AIDS) has many similarities to other disease states in that the same nutritional products and techniques are used. Some patients with HIV, and many with AIDS without secondary infection, experience a metabolic milieu similar to patients with cancer cachexia. In providing dietary counselling to the HIV patient, we encounter many of the obstacles that must be overcome to improve nutrition in cancer: anorexia, gastrointestinal discomfort, lethargy, and poor nutrient utilization, which limit the ability for nutritional repletion. When a secondary infection is superimposed on HIV, patients resemble more highly catabolic trauma patients or patients in the intensive care unit (ICU), where, despite aggressive efforts to feed, there is usually a net nitrogen wasting leading to the more rapid development of cachexia. However, even in this setting, feeding will limit substantially net catabolism when compared to total starvation. Because the nutritional needs of HIV patients vary greatly, individual strategies have to be designed as the patient moves through the stages of disease. Patients are generally able to consume adequate nutrition either as regular food or dietary supplements during the latency period of viral replication. Once secondary infections become prevalent, artificial diets administered by tube or by vein may be required during the period of active secondary infections, with dietary supplements often helpful during more quiescent periods. Patients with HIV are among the most challenging for clinicians providing nutritional support. Knowledge from treatment of patients with other diseases may be useful, but more data must be gathered on the unique aspects of aetiology and treatment of the anorexia, malabsorption, and ultimate wasting associated with AIDS.

Acquired Immunodeficiency Syndrome

Heart disease and hypertension in severe obesity: the benefits of weight reduction.

Severe obesity is associated with abnormalities of cardiac structure and function. These include an increased cardiac workload and ventricular hypertrophy. Hypertension in combination with severe obesity seriously burdens the heart because the increased preload and afterload compound cardiac work. Weight reduction induced by gastric operations for severe obesity is associated with resolution of hypertension, reduction in ventricular wall thickness and cardiac chamber size, as well as improved systolic function. Additional data are needed to predict when in the course of development of obese cardiomyopathy the changes in contractile function become irreversible. Additionally, the impact of coronary artery disease on the progression of obese cardiomyopathy and the effects of surgical weight reduction on cardiac structure and function need to be further clarified. Studies of the association between obesity, its treatment, and modification of cardiovascular risk are a major focus of preventive cardiology today.

Cardiomyopathies

Intra-abdominal sepsis and adrenergic receptor response.

This study measured the adrenergic receptor response of 13 patients with severe intra-abdominal sepsis, who required laparotomy and an open abdominal closure with Marlex mesh. The source of the sepsis was gram-negative organisms of intestinal origin. There were seven survivors and six nonsurvivors. When the patients were stratified into survivors and nonsurvivors, the Septic Severity Score, the APACHE II score, the Acute Physiological Score, and the Glasgow Coma Scale score results were not significantly different between groups. The alpha-2 and beta-1 adrenergic receptor responses were measured in the adipose tissue of the abdominal wall and the small bowel mesentery on day 1 of admission to the intensive care unit. The results demonstrated that the alpha-2 and beta-1 receptors of the nonsurvivors had a significantly decreased receptor response with desensitization and down regulation. The alpha-2 and beta-1 receptors of the survivors had an increased response with hypersensitization and up regulation. This study indicates that the adrenergic receptor pattern is distinctly different between survivors and nonsurvivors with severe abdominal gram-negative sepsis. The pattern differences occurred early (within 24 hours) when the patients had similar physiologic profiles. It is concluded that adrenergic receptor response may be a biologic indicator of the magnitude of the septic injury and a predictor of outcome.

Adipose Tissue