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Query: UMLS:C0022116 (ischemia)
 91,303 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Acquired immunodeficiency syndrome (AIDS) caused by the human immunodeficiency virus (HIV) may turn out to be the largest lethal epidemic of infection ever. The estimated global number of HIV-infected adults in 1993 was 13 million, with projections of up to 40 million by the year 2000. Human immunodeficiency virus infections and AIDS are relevant to surgeons with respect to the surgical management of AIDS patients in general, the treatment of the increasingly long list of surgical complications specific to AIDS patients in particular, and the risks of patient-to-surgeon and surgeon-to-patient HIV transmission. Because of migration of individuals and populations throughout the world, even surgeons practicing in relatively unaffected regions should be familiar with the potential surgical implications of AIDS. Ethical considerations arise, as well. Are surgeons obliged to operate on HIV-positive or AIDS patients? Some surgeons adhere strictly to the Hippocratic Oath, whereas others reserve the right to be selective on whom they operate, except in emergencies. Other common ethical considerations in the AIDS patient are similar to those arising in the terminal cancer case: whether to operate or not; whether to provide advanced support such as total parenteral nutrition or hemodialysis. Answers are not simple and require close collaboration between the surgeon, the AIDS specialist, and involved members of other specialties. Emergency operations become necessary to treat AIDS independent disease such as acute cholecystitis and appendicitis or AIDS-related life-threatening conditions such as gastrointestinal bleeding, obstruction, perforation, or ischemia complicating Kaposi's sarcoma, lymphoma, and cytomegalovirus or disseminated nontuberculous mycobacterial infections. Delays and errors in diagnosis are frequent. Poor nutritional state with weight loss, low serum albumin, and leukocyte count prevails in most patients requiring emergency operations and account for a high mortality. By applying solid judgment and selecting management appropriately, the surgeon has the ability to prolong life and to improve the quality of life for these unfortunate patients, and to do so with extremely minimal risk to himself and his team.
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PMID:AIDS, emergency operations, and infection control. 887 99

Renal retransplantation can be hampered by the presence of anti-HLA alloantibodies. Previous studies have documented in vitro and in vivo suppression of these antibodies by intravenous immunoglobulins (IVIg). We conducted a randomized study in 41 patients, who have received a second cadaveric transplant between 1989 and 1994. They all were treated with a quadruple-immunosuppressive protocol. In addition, 21 patients received 0.4 g/kg/day of IVIg, on the first 5 days after transplantation. The two groups of patients were identical for age, sex, duration of the first graft, duration of cold ischemia, anti-HLA sensitization, HLA matching, the number of acute rejection episodes, and the incidence of cytomegalovirus infection. The 5-year survival rate was significantly higher in the group of patients treated with IVIg: 68% versus 50% in the control group. The only significant factor associated with IVIg infusion and better survival was a shorter delay of graft function (3.4 +/- 1.0 days versus 9.9 +/- 1.6 days). In conclusion, this randomized study demonstrates that IVIg treatment is associated with better long-term graft survival in retransplanted patients. This beneficial effect may be related to a long-lasting immunosuppressive effect of IVIg and/or to an early protective effect of the graft against ischemia.
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PMID:Long-term benefit of intravenous immunoglobulins in cadaveric kidney retransplantation. 897 Jun 26

Tacrolimus was used as the primary immunosuppressive agent in 69 pediatric renal transplantations between December 17, 1989, and June 30, 1995. Children undergoing concomitant or prior liver and/or intestinal transplantation were excluded from analysis. The mean recipient age was 10.3+/-5.0 years (range, 0.7-17.5 years). Seventeen (24.6%) children were undergoing retransplantation, and six (8.7%) had a panel reactive antibody level of 40% or higher. Thirty-nine (57%) cases were with cadaveric kidneys, and 30 (43%) were with living donors. The mean donor age was 28.0+/-14.7 years (range, 1.0-50.0 years), and the mean cold ischemia time for the cadaveric kidneys was 27.0+/-9.4 hr. The antigen match was 2.7+/-1.2, and the mismatch was 3.1+/-1.2. All patients received tacrolimus and steroids, without antibody induction, and 26% received azathioprine as well. The mean follow-up was 32+/-20 months. One- and 4-year actuarial patient survival rates were 100% and 95%. One- and 4-year actuarial graft survival rates were 99% and 85%. The mean serum creatinine level was 1.2+/-0.8 mg/dl, and the calculated creatinine clearance was 82+/-26 ml/min/1.73 m2. The mean tacrolimus dose was 0.22+/-0.14 mg/ kg/day, and the level was 9.5+/-4.8 ng/ml. The mean prednisone dose was 2.1+/-4.9 mg/day (0.07+/-0.17 mg/kg/day), and 73% of successfully transplanted children were off prednisone. Seventy-nine percent were not taking any antihypertensive medications. The mean serum cholesterol level was 158+/-54 mg/dl. The incidence of delayed graft function was 4.3%. The incidence of rejection was 49%, and the incidence of steroid-resistant rejection was 6%. The incidence of rejection decreased to 27% in the most recent 26 cases (January 1994 through June 1995). The incidence of new-onset diabetes was 10.1%; six of the seven affected children were able to be weaned off insulin. The incidence of cytomegalovirus disease was 13%, and that of posttransplant lymphoproliferative disorder was 10%; the incidence of posttransplant lymphoproliferative disorder in the last 40 transplants was 5% (two cases). All of the children who developed posttransplant lymphoproliferative disorder are alive and have functioning allografts. Based on this data, we believe that tacrolimus is a superior immunosuppressive agent in pediatric renal transplant patients, with excellent short- and medium-term patient and graft survival, an ability to withdraw steroids in the majority of patients, and, with more experience, a decreasing rate of rejection and viral complications.
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PMID:Tacrolimus in pediatric renal transplantation. 899 Mar 56

We report a young man who, shortly after a primary cytomegalovirus infection, presented with signs of intestinal ischemia requiring surgical intervention. The resected specimen of small bowel showed striking features of extensive phlebitis and venulitis affecting virtually all of the veins of the small intestine and mesentery. Although he had had a recent primary cytomegalovirus viremia, we could not identify any evidence of cytomegalovirus in the small bowel. He was not infected with HIV. The entity we describe is different from the recently reported mesenteric inflammatory veno-occlusive disease. The clinicopathologic entity represented by our patient's disease was heretofore unrecognized.
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PMID:Extensive mesenteric inflammatory veno-occlusive disease of unknown etiology after primary cytomegalovirus infection: first case. 921 4

Heme oxygenase (HO-1) is a stress protein that has been suggested to participate in defense mechanisms against agents that induce oxidative injury such as hemoglobin/heme, hypoxia-ischemia and cytokines. Overexpression of HO-1 in endothelial cells (EC) might, therefore, protect against oxidative stress produced under these pathological conditions, by generation of CO, a vasodilator, and bilirubin, which has antioxidant properties that enhance blood vessel formation to counteract hypoxia-induced injury. A plasmid containing the cytomegalovirus promoter (pCMV) neomycin human HO-1 gene complexed to cationic liposomes, lipofectin, was used to transfect rabbit coronary microvessel EC. Cells transfected with human HO-1 gene demonstrated a twofold increase in HO activity and maintained a similar phenotype as in the nontransfected cells. Cell number in transfected cells with human HO-1 gene increased by about 45%, as compared to nontransfected or those transfected with control pCMV. Transfected and nontransfected EC revealed a similar response to basic fibroblast growth factor (bFGF) in capillary formation. However, transfected cells with the human HO-1 gene exhibited a twofold increase in blood vessel formation. The angiogenic response of EC to overexpression of HO-1 gene provides direct evidence that the inductive form of HO-1 following injury represents an important tissue adaptive mechanism for moderating the severity of cell damage produced in inflammatory reaction sites of hemorrhage, thrombosis and hypoxic-ischemia. Thus, HO-1 may participate in the regulation of EC activation, proliferation and angiogenesis.
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PMID:Gene transfer of human heme oxygenase into coronary endothelial cells potentially promotes angiogenesis. 940 20

After heart transplantation a number of factors such as pre- and postoperative hypoxia of the myocardium, myocardial failure of the early postoperative period, acute rejection episodes, cytomegalovirus infection, and finally the progressive atherosclerosis of the coronary arteries lead to the development of transplanted heart failure. Severe alterations of the myocardial function at this end stage of the process correspond to incurable cardiomyopathy. The target of plasmapheresis in this case is to decrease the extent of the disturbances in the lipoprotein contents and blood rheology for the improvement of the coronary perfusion of the transplanted heart. Nine patients with 3-7 year survival periods after heart transplantations underwent plasmapheresis twice a year using the Haemonetics PCS-plus machine. 2,100-2,700 ml of plasma was removed. Biochemical data, rheology and coagulation, and the concentration of Sandimmune (Sandoz Pharma Ltd., Basel, Switzerland) were controlled, and radionuclide scintigraphy of the myocardium, coronarographia, and transesophageal ultrasound investigations were completed for these patients. The result was the significant improvement of the coronary perfusion of the myocardium. The level of immunosuppression after the plasmapheresis procedures did not change and therefore did not demand any correction. Thus, we think that plasmapheresis can be an effective method of treatment of posttransplantation cardiomyopathy; the improvement of coronary perfusion decreases the extent of chronic ischemia. Further studies are necessary to answer the question as to whether it is possible to prolong the time before retransplantation with the help of plasmapheresis.
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PMID:Plasmapheresis in the treatment of posttransplant cardiomyopathy. 952 79

Lower extremity symptoms are caused by lesions at any level of the neuraxis, from cortex to muscle. HIV affects virtually every level of the nervous system, either directly or indirectly. The presence of pathology at multiple levels and by multiple processes further complicates the bedside diagnosis of a patient with AIDS and neurologic symptoms. Many neuropathies and other conditions that affect the lower extremities can be identified with careful history and physical examination, confirmed with limited testing, and can be treated successfully. Distal symmetric polyneuropathy is the most common lower extremity disorder, but it must be distinguished from similar-appearing neuropathies caused by medications, B12 deficiency, or vasculitis. Diffuse infiltrative lymphocytosis syndrome also causes a painful peripheral neuropathy that must be distinguished from distal symmetric polyneuropathy. Inflammatory demyelinating polyneuropathies are characterized by muscle weakness. They occur in early, asymptomatic HIV infection and respond to plasmapheresis or steroids. Mononeuropathies in patients with CD4 counts more than 200 often resolve on their own. Multiple mononeuropathies, which occur in patients with CD4 counts less than 50, are often associated with cytomegalovirus infection and may follow a rapidly progressive course unless treated promptly and aggressively. Progressive polyradiculopathy occurs late in the course of AIDS, is often caused by cytomegalovirus, is rapidly progressive, and generally is fatal unless recognized and treated promptly. Muscle weakness, myalgia, and fatigue are common in HIV and have multiple causes. Lower extremity spasticity may be caused by treatable etiologies such as spinal cord abscess, tumor, disc compression, B12 deficiency, or ischemia. Gait disturbances are common but nonspecific and may be caused by treatable neurologic disorders at any level of the neuraxis.
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PMID:Neurologic problems of the lower extremity associated with HIV and AIDS. 957 54

Each year, thousands of peoples die, suffering from an anatomical or functional loss of their intestine; these patients would benefit from bowel transplantation; the difficulties of bowel transplantation are as follows: 1. the physiological characteristics of the small bowel, and the fact that denervation, lymphatics interruption and ischemia, independently from rejection, may disturb its function; 2. secondly, the organ is septic; thus, its transplantation causes major infectious problems; 3. at last, the immunological characteristics of the intestinal allograft. Bowel transplantation causes a two-way immunological conflict, not only a standard rejection response, but also a graft-versus-host disease, similar to that observed after bone marrow transplantation; this reaction is caused by the lymphoid tissue conveyed within the bowel graft. The introduction of a new immunosuppressive molecule, FK 506, in combination with profound antibiotic prophylactic regimens, decontamination protocols and vigorous anti-viral protection (against cytomegalovirus and Epstein-Barr), have significantly improved the results. Bowel transplantation has recently reached clinical application. The one-year survival rate of intestinal grafts reaches now 70%. Still, there is no doubt that, due to its microbiological and immunological characteristics, the small bowel will remain the most challenging abdominal organ to transplant.
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PMID:[Intestinal transplantation: a clinical reality in 1998]. 976 Jul 59

Parenchymal microabscesses (MA) in liver transplant biopsies are frequently associated with cytomegalovirus (CMV) infection. However, other potential causes of MA have not been fully investigated. We studied additional etiologies for MA via histological evaluation and clinicopathological correlation. Three hundred seventy-two liver transplant biopsies from 97 patients (from 1991 to 1997) were reviewed and stained immunohistochemically for CMV. Numerous histological features were evaluated including size and number of MA, lobular and portal inflammation, and cholestasis. Medical records were reviewed for radiographic, laboratory, and other clinical data from the time of biopsy. The chi2 or Fisher's Exact test and ANOVA with adjusted multiple comparisons were used to determine statistical significance. Sixty-two of 372 biopsies (17%) from 43 patients contained MA. Biopsies were obtained between 4 days and 2.3 years posttransplant (median, 14 days). Nineteen percent of biopsies had CMV infection at the time of biopsy; 27% were associated with other bacterial, viral, or fungal infections; 10% had graft ischemia; 15% had biliary obstruction/cholangitis; 3% had a combination of ischemia and sepsis; and no explanation was found in 26% of biopsies. Numerous MA within a biopsy (>9) correlated with CMV infection (P <.005); no other histological features, including size of MA, correlated with the etiology of MA. Overall, 43 of 97 (44%) liver transplantation patients at our institution had biopsies demonstrating MA at some point in their posttransplantation course. CMV infection appears responsible for only a minority of cases. MA, although nonspecific, are an important histological finding in numerous conditions that may have a significant impact on both graft survival and overall patient morbidity.
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PMID:The significance of microabscesses in liver transplant biopsies: a clinicopathological study. 982 17

The incidence of atherosclerosis of the heart transplant in long term survivors is 38% at 5 years. In the present work, myocardial perfusion 201Tl-SPET was assessed as a non-invasive diagnostic method for the detection of postransplant coronary artery disease, as well as its efficiency with regard to other techniques. Twenty patients, aged (47 +/- 9) years old, who underwent heart transplantation at least 3 years earlier, were studied by 201Tl-SPET. Qualitative and quantitative analysis of the images were performed. It was found ischemia in 6 patients, 4 of them asymptomatics. In 5 of the 6 positive cases by SPET coronary stenosis was found by angiography. Kappa coefficient and percent of agreement were k = 0. 76 and Pe = 90%, respectively. There were no relationships among rejection crisis, sepsis by cytomegalovirus and coronary artery disease detected by using 201Tl-SPET (p > 0.05). The most relevant risk factors in the sample were hypertension and hyperlipidemia. Two patients died because of coronary artery disease. It was confirmed by necropsy findings. These results suggest that thallium-201 myocardial perfusion tomography could be useful to detect coronary artery disease in the transplanted heart.
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PMID:[Myocardial perfusion SPET in the detection of coronary artery disease in orthotopic heart transplantation]. 987 29


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