Prevalence of true vein graft aneurysms: implications for aneurysm pathogenesis. (33/39136)

BACKGROUND: Circumstantial evidence suggests that arterial aneurysms have a different cause than atherosclerosis and may form part of a generalized dilating diathesis. The aim of this study was to compare the rates of spontaneous aneurysm formation in vein grafts performed either for popliteal aneurysms or for occlusive disease. The hypothesis was that if arterial aneurysms form a part of a systemic process, then the rates of vein graft aneurysms should be higher for patients with popliteal aneurysms than for patients with lower limb ischemia caused by atherosclerosis. METHODS: Infrainguinal vein grafting procedures performed from 1990 to 1995 were entered into a prospective audit and graft surveillance program. Aneurysmal change was defined as a focal increase in the graft diameter of 1.5 cm or greater, excluding false aneurysms and dilatations after graft angioplasty. RESULTS: During the study period, 221 grafting procedures were performed in 200 patients with occlusive disease and 24 grafting procedures were performed in 21 patients with popliteal aneurysms. Graft surveillance revealed spontaneous aneurysm formation in 10 of the 24 bypass grafts (42%) for popliteal aneurysms but in only 4 of the 221 grafting procedures (2%) that were performed for chronic lower limb ischemia. CONCLUSION: This study provides further evidence that aneurysmal disease is a systemic process, and this finding has clinical implications for the treatment of popliteal aneurysms.  (+info)

The value of late computed tomographic scanning in identification of vascular abnormalities after abdominal aortic aneurysm repair. (34/39136)

PURPOSE: The purpose of this study was to determine the prevalence of late arterial abnormalities after aortic aneurysm repair and thus to suggest a routine for postoperative radiologic follow-up examination and to establish reference criteria for endovascular repair. METHODS: Computed tomographic (CT) scan follow-up examination was obtained at 8 to 9 years after abdominal aortic aneurysm (AAA) repair on a cohort of patients enrolled in the Canadian Aneurysm Study. The original registry consisted of 680 patients who underwent repair of nonruptured AAA. When the request for CT scan follow-up examination was sent in 1994, 251 patients were alive and potentially available for CT scan follow-up examination and 94 patients agreed to undergo abdominal and thoracic CT scanning procedures. Each scan was interpreted independently by two vascular radiologists. RESULTS: For analysis, the aorta was divided into five defined segments and an aneurysm was defined as a more than 50% enlargement from the expected normal value as defined in the reporting standards for aneurysms. With this strict definition, 64.9% of patients had aneurysmal dilatation and the abnormality was considered as a possible indication for surgical repair in 13.8%. Of the 39 patients who underwent initial repair with a tube graft, 12 (30.8%) were found to have an iliac aneurysm and six of these aneurysms (15.4%) were of possible surgical significance. Graft dilatation was observed from the time of operation (median graft size of 18 mm) to a median size of 22 mm as measured by means of CT scanning at follow-up examination. Fluid or thrombus was seen around the graft in 28% of the cases, and bowel was believed to be intimately associated with the graft in 7%. CONCLUSION: Late follow-up CT scans after AAA repair often show vascular abnormalities. Most of these abnormalities are not clinically significant, but, in 13.8% of patients, the thoracic or abdominal aortic segment was aneurysmal and, in 15.4% of patients who underwent tube graft placement, one of the iliac arteries was significantly abnormal to warrant consideration for surgical repair. On the basis of these findings, a routine CT follow-up examination after 5 years is recommended. This study provides a population-based study for comparison with the results of endovascular repair.  (+info)

Prevalence of generalised osteoarthritis in patients with advanced hip and knee osteoarthritis: the Ulm Osteoarthritis Study. (35/39136)

OBJECTIVES: Different prevalences of generalised osteoarthritis (GOA) in patients with knee and hip OA have been reported. The aim of this investigation was to evaluate radiographic and clinical patterns of disease in a hospital based population of patient subgroups with advanced hip and knee OA and to compare the prevalence of GOA in patients with hip or knee OA, taking potential confounding factors into account. METHODS: 420 patients with hip OA and 389 patients with knee OA scheduled for unilateral total joint replacement in four hospitals underwent radiographic analysis of ipsilateral and contralateral hip or knee joint and both hands in addition to a standardised interview and clinical examination. According to the severity of radiographic changes in the contralateral joints (using Kellgren-Lawrence > or = grade 2 as case definition) participants were classified as having either unilateral or bilateral OA. If radiographic changes of two joint groups of the hands (first carpometacarpal joint and proximal/distal interphalangeal joints defined as two separate joint groups) were present, patients were categorised as having GOA. RESULTS: Patients with hip OA were younger (mean age 60.4 years) and less likely to be female (52.4%) than patients with knee OA (66.3 years and 72.5% respectively). Intensity of pain and functional impairment at hospital admission was similar in both groups, while patients with knee OA had a longer symptom duration (median 10 years) compared with patients with hip OA (5 years). In 41.7% of patients with hip OA and 33.4% of patients with knee OA an underlying pathological condition could be observed in the replaced joint, which allowed a classification as secondary OA. Some 82.1% of patients with hip and 87.4% of patients with knee OA had radiographic changes in their contralateral joints (bilateral disease). The prevalence of GOA increased with age and was higher in female patients. GOA was observed more often in patients with knee OA than in patients with hip OA (34.9% versus 19.3%; OR = 2.24; 95% CI: 1.56, 3.21). Adjustment for the different age and sex distribution in both patient groups, however, takes away most of the difference (OR = 1.32; 95% CI: 0.89, 1.96). CONCLUSION: The crude results confirm previous reports as well as the clinical impression of GOA being more prevalent in patients with advanced knee OA than in patients with advanced hip OA. However, these different patterns might be attributed to a large part to a different distribution of age and sex in these hospital based populations.  (+info)

Semi-nested, multiplex polymerase chain reaction for detection of human malaria parasites and evidence of Plasmodium vivax infection in Equatorial Guinea. (36/39136)

A semi-nested, multiplex polymerase chain reaction (PCR) based on the amplification of the sequences of the 18S small subunit ribosomal RNA (ssrRNA) gene was tested in a field trial in Equatorial Guinea (a hyperendemic focus of malaria in west central Africa). The method uses a primary PCR amplification reaction with a universal reverse primer and two forward primers specific for the genus Plasmodium and to mammals (the mammalian-specific primer was included as a positive control to distinguish uninfected cases from inhibition of the PCR). The second amplification is carried out with the same Plasmodium genus-specific forward primer and four specific reverse primers for each human Plasmodium species. The PCR amplified products are differentiated by fragment size after electrophoresis on a 2% agarose gel. Four villages from three regions of the island of Bioko (Equatorial Guinea) and two suspected Plasmodium vivax-P. ovale infections from the hospital of Malabo were tested by microscopy and PCR. The PCR method showed greater sensitivity and specificity than microscopic examination and confirmed the existence of a focus of P. vivax infections in Equatorial Guinea suspected by microscopic examination. It also provided evidence of several mixed infections, mainly P. falciparum and P. malariae, the two predominant species causing malaria in Equatorial Guinea.  (+info)

Treatment of malarial acute renal failure by hemodialysis. (37/39136)

We studied 112 patients with malarial acute renal failure (ARF) during the period 1991-1997 at Bangkok Hospital for Tropical Diseases (Mahidol University, Bangkok, Thailand). Hemodialysis was performed in 101 (90.2%) of these patients. The mean number of times the patients were hemodialyzed was 6.5 (range = 1-27). Ninety-three (83.0%) patients were oliguric and the remainder were nonoliguric. Patients who had oliguric renal failure required more hemodialyses and had more complications than the nonoliguric patients. The oliguric patients had an eight-fold higher risk of requiring six or more hemodialyses (95% confidence interval = 1.2-53.9, P = 0.0008). The overall mortality rate was 10.7% (12 of 112). Eleven of the patients who died were jaundiced and eight of them had cerebral malaria with a Glasgow Coma Score < or = 8. We conclude that hemodialysis is a useful treatment for oliguric and nonoliguric ARF from severe malaria, particularly when initiated early in the course of the illness.  (+info)

Prevalence of intestinal parasite infections with special reference to Entamoeba histolytica on the island of Bioko (Equatorial Guinea). (38/39136)

The prevalence of intestinal parasitic infections was assessed (1993 through 1995) among two different groups of persons on the island of Bioko, Equatorial Guinea. In the first group, parasitologic examinations were performed on stool specimens from a household-based sample of 557 dwellers from the rural area of the island. In the second group, 1,633 inpatients and outpatients at the General Hospital of Malabo (the capital of the country) were studied. All age groups were represented in both groups. The average prevalence of the most common protozoan and helminthic intestinal infections in rural and urban areas, respectively, was as follows: Entamoeba histolytica/E. dispar (14.9% and 32.7%, respectively), Giardia lamblia (7.2% and 8.6%), Ascaris lumbricoides (45.8% and 31.4%), and Trichuris trichiura (25.7% and 36.4%). Seventy-nine sera from patients with amebic liver abscess (suspected by ultrasonography) were studied by an immunohemagglutination assay, with 44 (56%) showing anti-E. histolytica titers > or = 1:32. Of these 79 sera, 71 were studied by an enzyme immunoassay, 86% of which were positive with titers > or = 1:64. This study showed that parasitic infections in Equatorial Guinea represent a major health problem.  (+info)

Prevalence of enteric hepatitis A and E viruses in the Mekong River delta region of Vietnam. (39/39136)

A study of antibody prevalence for hepatitis A virus (HAV) and hepatitis E virus (HEV) was carried out in southwestern Vietnam in an area adjacent to a known focus of epidemic HEV transmission. The purpose of this investigation was first to provide a prevalence measure of hepatitis infections, and second to determine the outbreak potential of HEV as a function of the susceptible population. Blood specimens collected from 646 persons in randomly selected village hamlets were examined by an ELISA for anti-HEV IgG and anti-HAV IgG. The prevalences of anti-HEV IgG and anti-HAV IgG were 9% and 97%, respectively. There was a significant increase (P < 0.01) in age-specific anti-HEV IgG. A notable increase in anti-HAV IgG prevalence (P < 0.0001) occurred between child populations 0-4 (64%) and 5-9 (95%) years of age. No evidence of familial clustering of anti-HEV IgG-positive individuals was detected, and household crowding was not associated with the spread of HEV. Boiling of water was found to be of protective value against HEV transmission. A relatively low prevalence of anti-HEV indicates considerable HEV outbreak potential, against a background of 1) poor, water-related hygiene/sanitation, 2) dependence on a (likely human/animal waste)-contaminated Mekong riverine system, and 3) periodic river flooding.  (+info)

Isolation of tick-borne encephalitis virus from wild rodents and a seroepizootiologic survey in Hokkaido, Japan. (40/39136)

To determine the vertebrate host of tick-borne encephalitis (TBE) virus in the southern part of Hokkaido, Japan, virus isolation was performed using spleens from small mammals captured in the area. Two virus strains were isolated, one strain from Apodemus speciosus and another from Clethrionomys rufocanus. Virus isolates were inoculated onto baby hamster kidney cell monolayers and antigen slides were prepared for an indirect immunofluorescent antibody assay. Two isolates were identified as TBE viruses by monoclonal antibody reactions. To specify the TBE-endemic area in Hokkaido, rodent, horse, and dog sera collected from 1992 to 1997 were tested for neutralization antibody against TBE virus previously isolated from a dog. The positive cases were distributed in four districts in the southern part of Hokkaido.  (+info)