Investigation of association of mycobacteria with inflammatory bowel disease by nucleic acid hybridization.

We used DNA-DNA hybridization to characterize a mycobacterial isolate, strain Linda, that was obtained from a patient with Crohn's disease and that has been reported to cause ileitis in experimental animals. We also investigated the association of this mycobacterium with Crohn's disease. Our results identified Mycobacterium strain Linda as a strain of Mycobacterium paratuberculosis, the etiologic agent of Johne's disease, a disease of ruminants that has some superficial resemblance to Crohn's disease. Sequences that hybridized with strain Linda DNA probes were detected in DNA extracted from human intestinal tissues from patients with Crohn's disease, ulcerative colitis, and noninflammatory bowel disease. These hybridizing DNA sequences were more prevalent in the muscle layers than in the intestinal mucosa, making it unlikely that they represented DNA from bacterial contaminants in the intestinal lumen. Measurement of the melting temperatures of the DNA-DNA hybrids formed between strain Linda probes and tissue DNAs indicated that the related sequences detected were of mycobacterial origin but were not identical to each other or to strain Linda DNA. These results do not support the proposed specific relationship between Mycobacterium strain Linda and Crohn's disease. The possible etiologic role of mycobacteria in Crohn's disease is discussed.     

Hypercholesterolaemia and a silent MI

Results of investigations in extraordinary patients should be dealt with cautiously; it is often prudent to repeat tests. Though the aims of treatment in such cases are often the same, differences in approach to the problem are illuminating.     

A model for sustainable short-term international medical trips.

The health status of many people in developing countries is often dismal compared with the norms in industrialized countries. Increasingly, medical practitioners in the United States and other industrialized countries have become interested in global health issues, an interest that often takes the form of short-term international medical trips. We discuss several ethical issues associated with participation in such trips and use our experiences in developing the Children's Health International Medical Project of Seattle (CHIMPS) to outline and illustrate a set of 7 guiding principles for making these trips. CHIMPS is a resident-run, faculty-supported international medical program founded in 2002 by pediatric residents at the University of Washington in Seattle. Members of CHIMPS work with a rural community in El Salvador to support ongoing public health interventions there and provide sustainable medical care in collaboration with the community and a local nongovernmental organization. The 7 principles developed as a result of this work-mission, collaboration, education, service, teamwork, sustainability, and evaluation-can be used as a model for health practitioners as they develop or select international medical trips. The importance of partnering with the community and working within the existing medical and public health infrastructure is emphasized. Many of the challenges of doing international medical work can be overcome when efforts are guided by a few specific principles, such as those we have outlined.     

Coagulopathy induced by aortoiliac aneurysms

Diffuse intravascular coagulopathy (DIC) or consumptive coagulopathy is infrequently associated with aortic aneurysms. When the two coexist, they create a difficult clinical problem that requires optimal medical and surgical care. Two cases of coagulopathy associated with aortoiliac aneurysm are presented to exemplify the broad clinical picture that can be present. The definitive treatment of DIC is removal of the underlying cause. The following recommendations are made for the management of patients with aortic aneurysms and possible coagulopathy: preoperatively examine the patient for hematomas and ecchymoses; measure levels of fibrinogen, platelets and fibrin degradation products and the prothrombin and partial thromboplastin times; perform arteriography and check puncture sites for spontaneous bleeding afterwards; at aneurysm repair ensure meticulous hemostasis and compensate for excessive blood loss by high-speed autotransfusion.     

Skin Cancer Prevention: A Time for Action

Skin cancer is the most common malignancy in the United States accounting for more than 840,000 cases and 9,400 deaths annually. It is estimated that 90% of non-melanoma skin cancers and much of melanoma incidence can be attributed to sun exposure. The evidence suggests that regular use of sunscreen (Sun Protective Factor (SPF) of 15 or higher), wearing protective, tightly woven clothing and wide brimmed hats, and avoiding sun exposure when the ultraviolet rays are strongest (between 11:00 a.m. and 3:00 p.m.) can dramatically reduce the risk of skin cancer. Interventions to promote sun-protection behaviors that target children and adults are necessary to reduce the growing incidence rate of skin cancer in the United States.MA during the time of this research     

Low sodium haemodialysis reduces interdialytic fluid consumption but paradoxically increases post-dialysis thirst.

BACKGROUND: Interdialytic weight gain (IDWG) can be reduced by lowering the dialysate sodium concentration ([Na]) in haemodialysis patients. It has been assumed that this is because thirst is reduced, although this has been difficult to prove. We compared thirst patterns in stable haemodialysis patients with high and low IDWG using a novel technique and compared the effect of low sodium dialysis (LSD) with normal sodium dialysis (NSD). METHODS: Eight patients with initial high IDWG and seven with low IDWG completed hourly visual analogue ratings of thirst using a modified palmtop computer during the dialysis day and the interdialytic day. The dialysate [Na] was progressively reduced by up to 5 mmol/l over five treatments. Dialysis continued at the lowest attained [Na] for 2 weeks and the measurements were repeated. The dialysate [Na] then returned to baseline and the process was repeated. RESULTS: Baseline interdialytic day mean thirst was higher than the dialysis day mean for the high IDWG group (49.9+/-14.0 vs 36.2+/-16.6) and higher than the low weight gain group (49.9+/-14.0 vs 34.1+/-14.6). This trend persisted on LSD, but there was a pronounced increase in post-dialysis thirst scores for both groups (high IDWG: 46+/-13 vs 30+/-21; low IDWG: 48+/-24 vs 33+/-18). The high IDWG group demonstrated lower IDWG during LSD than NSD (2.23+/-0.98 vs 2.86+/-0.38 kg; P<0.05). CONCLUSIONS: Our results indicate that patients with high IDWG experience more intense feelings of thirst on the interdialytic day. LSD reduces their IDWG, but paradoxically increases thirst in the immediate post-dialysis period.     

MRI relaxation fluctuations in acute reperfused hemorrhagic infarction.

MRI evaluations of intramyocardial hemorrhage in acute infarction have relied on T(2) and T(2)(*) shortening only. We propose a more comprehensive evaluation of hemorrhagic infarction based on the concept that fluctuations in T(2) and T(1) relaxation in acute reperfused infarction will reflect transient edema and hemoglobin oxidative denaturation to uncompartmentalized methemoglobin. Anteroapical infarction was created via percutaneous balloon in young swine (22-25 kg, N = 12). T(2), T(1), diastolic wall thickness (DWT), and the Gd-DTPA partition coefficient (lambda) were measured on days 0, 2, and 7. DWT was elevated at 1 hr postreperfusion (128% +/- 53%, P = 0.0001), and alleviated on days 2 and 7 (48% +/- 10%, P = 0.008; 53% +/- 24%, P = 0.003). T(2) and T(1) elevations were coincident with early edema (DeltaT(2) = 55% +/- 24%, P < 0.0001; DeltaT(1) = 27% +/- 18%, P < 0.04). T(2) and T(1) were nearly normal on day 2 (DeltaT(2) = 8% +/- 8%, P = 0.27; DeltaT(1) = 0% +/- 1%, P = 0.65). On day 7, T(2) increased while T(1) decreased (DeltaT(2) = 27% +/- 16%, P = 0.005; DeltaT(1) = -14% +/- 10%, P = 0.02). Lambda was elevated by >150% at all time points (P < or = 0.002). Histology verified hemorrhagic injury. T(1) and T(2) fluctuations are consistent with transient edema, as well as hemoglobin oxidative denaturation to decompartmentalized methemoglobin. This methodological development may broaden our understanding of hemorrhagic microvascular injury and improve its detection in clinical populations.     

Quantitation of photochemically induced focal cerebral ischemia in the rat

This study was carried out with a recently developed model of focal cerebral ischemia in the rat based on the photochemical induction of thrombotic stroke using the dye Rose Bengal. We examined the change in the volume of the lesion and brain water content, in separate groups of rats, at different times (1, 4, 24, 72, and 168 h) after the induction of the ischemic lesion. The volume of ischemic damage increased rapidly between 1 and 24 h after the ischemic insult and decreased between 24 and 168 h. The lesion at 168 h was significantly larger than that following 1 h of ischemia and similar to that obtained at 4 h, suggesting that the maximum extent of tissue damage (without the involvement of significant edema) was reached within the first 4 h in this model. The enlargement of the lesion after 4 h correlated closely with changes in brain water content.