Recreational marijuana use is not associated with worse outcomes after renal transplantation

As marijuana (MJ) legalization is increasing, kidney transplant programs must develop listing criteria for marijuana users. However, no data exist on the effect of MJ on kidney allograft outcomes, and there is no consensus on whether MJ use should be a contraindication to transplantation. We retrospectively reviewed 1225 kidney recipients from 2008 to 2013. Marijuana use was defined by positive urine toxicology screen and/or self‐reported recent use. The primary outcome was death at 1 year or graft failure (defined as GFR<20 mL/min/1.73 m²). The secondary outcome was graft function at 1 year. Using logistic regression analyses, we compared these outcomes between MJ users and non‐users. Marijuana use was not associated with worse primary outcomes by unadjusted (odds ratio 1.07, 95% CI 0.45–2.57, P=.87) or adjusted (odds ratio 0.79, 95% CI 0.28–2.28, P=.67) analysis. Ninety‐two percent of grafts functioned at 1 year. Among these, the mean creatinine (1.52, 95% CI 1.39–1.69 vs 1.46, 95% CI 1.42–1.49; P=.38) and MDRD GFR (50.7, 95% CI 45.6–56.5 vs 49.5, 95% CI 48.3–50.7; P=.65) were similar between groups. Isolated recreational MJ use is not associated with poorer patient or kidney allograft outcomes at 1 year. Therefore, recreational MJ use should not necessarily be considered a contraindication to kidney transplantation.     

Gas-liquid chromatography in the diagnosis of anaerobic infections: a three year experience.

Nearly two thousand clinical samples were examined by direct gas-liquid chromatography over a three year period. Absence of volatile fatty acids (VFAs) in the samples correlated well with negative culture results for anaerobic bacteria. In general the presence of acetic acid alone correlated well with the presence of aerobic organisms, whereas the presence of a mixture of VFAs correlated well with the presence of anaerobic organisms, either alone or in combination with aerobes. However a proportion of such VFA-positive samples gave no growth on culture. Swabs gave comparable results to samples of pus or exudates except that a higher proportion of the former were VFA-negative but culture positive.     

Altered red cell membrane fluidity during schizogonic development of malarial parasites (Plasmodium falciparum and P. lophurae)

The plasma membranes of human or duckling erythrocytes infected with malarial parasites (Plasmodium falciparum and P. lophurae respectively) were stained by the fluorescent dye merocyanine 540 in the presence of serum. Unparasitized erythrocytes from infected ducklings or from in vitro cultures remained unstained in the presence of serum. Because merocyanine 540 has a greater affinity for fluid phased or disordered lipid bilayers the results suggest that upon infection of the red blood cell the erythrocyte plasma membrane becomes disordered or is increased in its fluidity. Such alterations of the host erythrocyte are probably due to parasite-induced modifications in the underlying spectrin network (required for lipid leaflet asymmetry) as well as changes in erythrocyte membrane lipid composition.     

Receptor mediated action without receptor occupancy

The relationship between occupancy of a specific cell surface receptor and actions initiated in the same cell by that event was tested on ovarian granulosa cells exposed to hCG. Hormone bound to its receptor was identified by immunocytochemistry or by autoradiography and the dissociation of cAMP-dependent protein kinase was followed by direct cytochemistry. Only 25-30% of the granulosa cells bound hCG and in each instance this resulted in protein kinase dissociation. Cells that did not bind hCG nevertheless dissociated protein kinase if they contacted a cell that had bound hormone and dissociated enzyme. Cells that neither bound hormone, nor contacted cells that did so, failed to dissociate protein kinase. These observations establish, in individual cells, a direct relationship of receptor occupancy to receptor-mediated action and indicate that this event can be communicated to receptorless cells, presumably by gap junctions, thereby amplifying the response to hormone. Similar processes may occur in other tissues wherein receptor-bearing cells are capable of intercellular communication.     

Immunofluorescent and immunoelectron microscopic localization of protein antigens in red cells infected with the human malaria Plasmodium falciparum

Erythrocytes infected with the human malaria Plasmodium falciparum produce elevations of the surface membrane of the red cell called knobs. Through the use of transmission electron microscopy and a post-embedding protein A-immunogold technique, it was possible to show changes in the distribution of band 3, glycophorin A and spectrin in the region of the knob. These proteins appeared to be aggregated or condensed in the area of the knob, whereas the remainder of the red cell surface showed no such dense clusters; haemoglobin and the histidine-rich protein of P. lophurae could not be localized to the knobby protuberances. It was not possible to detect any changes in protein distribution using the light microscope and indirect immunofluorescence.