Are all n-3 polyunsaturated fatty acids created equal?

N-3 Polyunsaturated fatty acids have been shown to have potential beneficial effects for chronic diseases including cancer, insulin resistance and cardiovascular disease. Eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) in particular have been studied extensively, whereas substantive evidence for a biological role for the precursor, alpha-linolenic acid (ALA), is lacking. It is not enough to assume that ALA exerts effects through conversion to EPA and DHA, as the process is highly inefficient in humans. Thus, clarification of ALA's involvement in health and disease is essential, as it is the principle n-3 polyunsaturated fatty acid consumed in the North American diet and intakes of EPA and DHA are typically very low. There is evidence suggesting that ALA, EPA and DHA have specific and potentially independent effects on chronic disease. Therefore, this review will assess our current understanding of the differential effects of ALA, EPA and DHA on cancer, insulin resistance, and cardiovascular disease. Potential mechanisms of action will also be reviewed. Overall, a better understanding of the individual role for ALA, EPA and DHA is needed in order to make appropriate dietary recommendations regarding n-3 polyunsaturated fatty acid consumption.     

Pancreatic pseudocysts drained through a percutaneous transgastric approach

We describe a new method for the percutaneous drainage of pancreatic pseudocysts using a transgastric approach. We used this technique in three dogs and six patients for whom no other "safe" access route was available. The procedures were performed under US guidance alone or with US combined with fluoroscopy. No complications were observed.     

Centrilobular emphysema: CT-pathologic correlation

Over a 5-year period, 25 patients who had undergone chest computed tomography (CT) died and were autopsied. Their lungs were fixed in the inflated state and were assessed for the presence and severity of centrilobular emphysema (CLE). Three radiologists independently evaluated the CT scans for nonperipheral low-attenuation areas, peripheral low-attenuation areas, pulmonary vascular pruning, pulmonary vascular distortion, and pulmonary density gradient. The CT criterion that best correlated with the presence and severity of CLE was the nonperipheral low-attenuation area. With this CT criterion, lung destruction was correctly identified in 13 of 15 cases. The absence of this criterion resulted in correct identification of eight of ten normal lungs. These preliminary data suggest that CLE can be reliably identified and quantified with current CT scanners.     

Patient expectations of radiology in noninteractive encounters

Open-ended interviews with 107 patients documented specific patient expectations of radiologic procedures during which there was no direct radiologist-patient interaction. Patient expectations could be classified into those related to the facility and those related to interactions with radiology staff. Among facility-related expectations, waiting time far outweighed all other concerns. Interpersonal skills were the predominant expectation of radiology staff. The role of the radiologist in fulfilling patient expectations was less clear. Only 10% of unprompted patients cited the radiologist as a factor in their expectations. When patients were specifically prompted to discuss the radiologist's role, communication skills, accuracy of interpretation, and interpersonal skills were the predominant concerns.     

The relationship of cerebral atrophy and T1 in alcoholics: an MRI study

There was a significant correlation between two measures of cerebral atrophy (the ventricle to brain ratio and the relative cerebral volume) and T1 in 19 detoxified alcoholics. This provides further evidence that T1 is a marker of structural damage in alcoholics although the partial volume effect of CSF may contribute to this finding. This has implications for studies comparing alcoholics to normal controls and suggests that better ways of excluding CSF need to be found.     

Primary diffuse large B-cell lymphoma of the uterus presenting solely as an endometrial polyp.

We report a primary diffuse large B-cell lymphoma of endometrial polyp in a 44-year-old woman who presented with irregular vaginal spotting and was found to have a polyp protruding from the cervical os. Histology of the polyp showed an atypical diffuse infiltration by large, mononuclear cells within the stroma and between endometrial glands in one of the polypoid fragments. Immunohistochemistry and testing for immunoglobulin heavy chain gene rearrangement showed a B-cell lineage, consistent with diffuse large B-cell lymphoma. Staging procedures including detailed gynecology examination, body computed tomography scan, and bone marrow examination, as well as total hysterectomy, showed no evidence of lymphoma outside of the polyp. To our knowledge, this represents the first well-documented instance of primary lymphoma of the uterus presenting as an endometrial polyp. The differential diagnosis of endometrial biopsies containing an atypical lymphoid infiltrate should include the rather rare possibility of primary uterine lymphoma arising in an endometrial polyp. Immunohistochemistry and/or molecular analysis for antigen receptor gene rearrangements are critical in arriving at the correct diagnosis.     

Successful treatment of diabetes with the biohybrid artificial pancreas in dogs

We have investigated a new hybrid artificial pancreas device to transplant islet allografts without immunosuppression. The device consists of a chamber through which passes a copolymer membrane connected to standard vascular grafts. Islets are placed inside the chamber but are outside of the blood stream. Nominal molecular porosity of 80,000 daltons permits free diffusion of nutrients and insulin across the membrane but inhibits the entry of immunoglobulins and immunocytes from the blood stream into the chamber. Initial studies focused on the technical feasibility of implanting the unseeded (no islets) devices. In 12 normal mongrel dogs, the arterial limb of the device was anastomosed end-to-end to the common iliac artery and the venous limb end-to-side to the common iliac vein. Vascular patency was monitored by an audible bruit over the device. Two devices currently remain patent at 388 and 421 days. The remaining experiments failed due to thrombosis and membrane rupture, with 2 failing as late as 170 and 279 days. In a second series, both arterial and venous anastomoses were done end-to-side and dogs were placed on low-dose aspirin therapy. All 8 dogs are currently maintaining patent unseeded devices (96-226 days postimplantation). Subsequent studies determined the function of devices seeded with isolated canine pancreatic islet allografts in totally pancreatectomized, severely diabetic dogs. Diabetes was controlled by once-a-day insulin injection. After 2-3 weeks of diabetic control, a seeded device was implanted. Diabetic control was monitored by fasting blood levels and postprandial and intravenous glucose tolerance tests, and vascular patency by the loudness of the bruit. In the first series of 6 dogs given seeded devices without aspirin, no significant function was discernible, with failure attributable to thrombosis, poor islet viability, and surgical complications. In the second series of 13 dogs given aspirin, 8 dogs have required an appreciably lower dose of injected insulin to maintain fasting blood glucose at acceptable levels. Of note are 4 dogs that required virtually no exogenous insulin for at least 3 weeks. One dog lost function on day 74 and another still requires no insulin at 267 days postimplantation. However, despite normal fasting glucose levels, the glucose tolerance tests showed delayed return to normal levels. Weight lost following pancreatectomy was rapidly regained in the presence of a functioning seeded device. Histologic examination of the removed devices revealed no signs of rejection.     

Heterogeneity of anti-U demonstrable by the use of papain-treated red cells

When red cells (RBCs) are treated with papain, one form of the U antigen, which we have named UPS (U papain-sensitive), is almost completely removed or denatured. A second form, UPR (U papain-resistant), remains unaltered on the treated RBCs. Tests on 42 examples of anti-U showed that two contained only anti-UPS, 19 contained only -UPR, and 21 contained separable -UPS and -UPR. In those sera containing both antibodies, anti-UPR was always the stronger of the two. These findings suggest 1) that UPS is located on the Ss sialoglycoprotein (glycophorin B) at a position distal to a papain-sensitive site or that the cleavage point is within the portion of the SGP that comprises UPS, and 2) that UPR is located between the papain-sensitive site and the RBC membrane. The UPS determinant was not denatured by neuraminidase, L-cysteine, trypsin, ficin, or alpha-chymotrypsin, and it was only partially denatured by pronase. The finding that RBCs treated with para-chloromercuribenzoic acid or para-chloromercuriphenyl sulfonic acid did not react with anti-UPR but did continue to react with anti-UPS suggests that the in situ configuration of UPR, but not UPS, is dependent on the presence of one or more disulfide bonds. RBCs of the S-s-U+(weak) phenotype were shown to carry markedly reduced amounts of both UPS and UPR.