Plasmid-determined resistance to fosfomycin in Serratia marcescens.

Multiple-antibiotic-resistant strains of Serratia marcescens isolated from hospitalized patients were examined for their ability to transfer antibiotic resistance to Escherichia coli by conjugation. Two different patterns of linked transferable resistance were found among the transconjugants. The first comprised resistance to carbenicillin, streptomycin, and fosfomycin; the second, and more common, pattern included resistance to carbenicillin, streptomycin, kanamycin, gentamicin, tetracycline, chloramphenicol, sulfonamide, and fosfomycin. The two types of transconjugant strains carried a single plasmid of either 57 or 97 megadaltons in size. Both of these plasmids are present in parental S. marcescens strains resistant to fosfomycin. The 57-megadalton plasmid was transformed into E. coli.     

Characterization of apolipoprotein A-I- and A-II-containing lipoproteins in a new case of high density lipoprotein deficiency resembling Tangier disease and their effects on intracellular cholesterol efflux.

A 48-yr-old Caucasian female of central European origin (subject IM) with low plasma cholesterol and normal plasma triglyceride (TG) had extremely low apo A-I (6 mg/dl), A-II (5 mg/dl), and HDL cholesterol (2 mg/dl) levels. She had most of the clinical symptoms typically associated with Tangier disease, including early corneal opacities, yellow-streaked tonsils, hepatomegaly, and variable degrees of peripheral neuropathy, but had no splenomegaly. She had a myocardial infarction at age 46. Since HDL are postulated to be involved in the transport of excess cholesterol from peripheral tissues to the liver for degradation, and the ability of an HDL particle to promote cellular cholesterol efflux appears to be related to its density, size, and apo A-I and A-II contents, we isolated and characterized the HDL particles of this patient and all her first degree relatives (mother, a brother, and two children). The plasma A-I, A-II, and HDL cholesterol levels of all five relatives were either normal or high. Using anti-A-I and anti-A-II immunosorbents, we found three populations of particles in IM: one contained both apo A-I and A-II, Lp(AI w AII); one contained apo A-I but no A-II, Lp(AI w/o AII); and the third (an unusual one) contained apo A-II but no A-I, Lp(AII). Two-thirds of her plasma A-I and A-II existed in separate HDL particles, i.e., in Lp(AI w/o AII) and Lp(AII), respectively. Only Lp(AI w AII) and Lp(AI w/o AII) were present in the plasma of the relatives. All three populations of the patient's HDL particles had a normal core/surface lipid ratio, but the cores were enriched with TG. The apo A-I-containing particles, however, were considerably smaller and contained much less lipid than Lp(AII). Despite these unusual physicochemical characteristics, the apo A-I-containing particles and Lp(AII) were effective suppressors of intracellular cholesterol esterification in cholesterol-loaded human skin fibroblast. The patient's plasma apo D and lecithin cholesterol acyltransferase levels were reduced, with an increased proportion located in non-HDL plasma fractions. These findings are discussed in light of Tangier disease and other known HDL-deficiency cases, and the role of HDL in the maintenance of cell cholesterol homeostasis.     

Feasibility of Spectral Domain Optical Coherence Tomography Acquisition Using a Handheld Versus Conventional Tabletop Unit

Purpose:

Patients afflicted with ocular complications of diabetes represent a diverse demographic who often cannot undergo spectral-domain optical coherence tomography (SD-OCT) imaging of the retina due to postural restraints. Our pilot study compared imaging acquisition methods using SD-OCT in the handheld (HH) mode versus the conventional tabletop (TT) method.

Methods:

Our study included 22 undilated eyes of 22 subjects (mean ± SD age, 35.8 ± 16.8 years) imaged using HH and TT iVue SD-OCT (Optovue, Fremont, CA). Statistical analysis was performed using Microsoft Excel 12.2.7 (Microsoft Corporation, Redmond, WA) software with an accepted significance of P < .05.

Results:

Strong intraclass correlation coefficient was observed for (1) overall (.97), superior (.93), and inferior (.94) ganglion cell complex thickness, and (2) central (.98), inferior (.90), superior (.92), nasal (.94), and temporal (.93) macular retinal thickness. Mean scan quality index was adequate but lower in HH versus TT SD-OCT (62.8 vs 68.1, respectively; P < .0001). Multiple attempts for adequate imaging were required more frequently in HH versus TT SD-OCT (34% vs 5%, respectively; P < .001).

Conclusion:

HH SD-OCT may be a feasible alternative to TT SD-OCT in select situations, especially in patients suffering from diabetic complications with limited mobility.     

Acquired immunodeficiency syndrome-associated non-Hodgkin's lymphomas and other malignancies in patients with hemophilia

Non-Hodgkin's lymphoma (NHL) is the most common human immunodeficiency virus (HIV)-associated malignancy in hemophiliacs. We studied the incidence and clinicopathologic features of NHL in 3,041 hemophiliacs followed at 18 US Hemophilia Centers between 1978 and 1989. Of the 1,295 (56.6%) who were HIV(+), 253 (19.5%) developed acquired immunodeficiency syndrome (AIDS), of whom 14 (5.5%) developed NHL. Three NHL occurred in HIV(-) hemophiliacs, for a 36.5-fold greater risk in HIV(+) than HIV(-) hemophiliacs (P < .001). The NHL incidence rate was 29-fold greater than in the US population by Surveillance, Epidemiology, and End Results (SEER) estimates (P < .001). Between 0 and 4 lymphomas have been observed per year between 1978 and 1989. At presentation 13 (92.9%) of the HIV(+) NHL were extranodal. Ten were stage IV, 1 stage II, and 3 stage IE. Ten (71.4%) were high-grade, 3 (21.4%) intermediate-grade, and 1 (7.1%) was a low-grade B-cell lymphoma. Epstein-Barr virus (EBV) DNA was detected in 36% by in situ hybridization, including one central nervous system (CNS) lymphoma. The mean CD4 cell count at NHL diagnosis was 64/mm3, the mean latency from initial HIV infection was estimated to be 59 months, and the median survival was 7 months. The incidence of basal cell carcinoma in HIV(+) hemophiliacs was 18.3-fold greater than in HIV(-) hemophiliacs (P < .001) and 11.4-fold greater than in the US population (P < .001). In conclusion, incidence rates of NHL and basal cell carcinoma in HIV(+) hemophiliacs are significantly increased over rates in HIV(-) hemophiliacs and over rates in the US population. Clinicopathologic presentation of NHL in HIV(+) hemophiliacs is similar to that in HIV(+) homosexual men.     

Emotional quotient in frontotemporal dementia vs. Alzheimer’s disease: the role of socioemotional agnosia

Introduction: Socioemotional dysfunction distinguishes behavioural variant frontotemporal dementia (bvFTD) from other dementias. Patients with bvFTD not only have early social impairment and emotional blunting, but they also have agnosia of their socioemotional dysfunction.

Methods: To investigate the relationship between agnosia and dysfunction, we assessed self-knowledge of socioemotional dysfunction with an emotional quotient (EQ) scale administered to 12 patients with bvFTD and a comparison group of 12 age-matched patients with Alzheimer’s disease (AD), and compared these self-ratings to caregiver ratings of social dysfunction and emotional blunting.

Results: The bvFTD patients self-rated as having higher EQs than the AD patients, particularly higher self-ratings of their Social Skills, an EQ subscale which correlated with increased emotional blunting. On within-groups analysis, the bvFTD patients’ high self-ratings of their EQ Appraisal of Emotions correlated with increased socioemotional dysfunction, whereas all of the AD patients’ self-ratings correlated appropriately with their degree of dysfunction.

Conclusions: Large socioemotional agnosia scores (EQ minus function) distinguishes bvFTD from AD. Additionally, in bvFTD, agnosia specifically for their ability to appreciate others’ emotions correlates with the degree of socioemotional dysfunction, suggesting a role for socioemotional agnosia in increasing socioemotional dysfunction.     

The Assembly of GM1 Glycolipid- and Cholesterol-Enriched Raft-Like Membrane Microdomains Is Important for Giardial Encystation

Although encystation (or cyst formation) is an important step of the life cycle of Giardia, the cellular events that trigger encystation are poorly understood. Because membrane microdomains are involved in inducing growth and differentiation in many eukaryotes, we wondered if these raft-like domains are assembled by this parasite and participate in the encystation process. Since the GM1 ganglioside is a major constituent of mammalian lipid rafts (LRs) and known to react with cholera toxin B (CTXB), we used Alexa Fluor-conjugated CTXB and GM1 antibodies to detect giardial LRs. Raft-like structures in trophozoites are located in the plasma membranes and on the periphery of ventral discs. In cysts, however, they are localized in the membranes beneath the cyst wall. Nystatin and filipin III, two cholesterol-binding agents, and oseltamivir (Tamiflu), a viral neuraminidase inhibitor, disassembled the microdomains, as evidenced by reduced staining of trophozoites with CTXB and GM1 antibodies. GM1- and cholesterol-enriched LRs were isolated from Giardia by density gradient centrifugation and found to be sensitive to nystatin and oseltamivir. The involvement of LRs in encystation could be supported by the observation that raft inhibitors interrupted the biogenesis of encystation-specific vesicles and cyst production. Furthermore, culturing of trophozoites in dialyzed medium containing fetal bovine serum (which is low in cholesterol) reduced raft assembly and encystation, which could be rescued by adding cholesterol from the outside. Our results suggest that Giardia is able to form GM1- and cholesterol-enriched lipid rafts and these raft domains are important for encystation.     

Results of percutaneous coronary intervention of the unprotected left main coronary artery in 143 patients and comparison of 30-day mortality to results of coronary artery bypass grafting

Percutaneous coronary intervention (PCI) of the unprotected left main coronary artery (LMCA) is controversial. In 143 patients who underwent PCI of the unprotected LMCA, 30-day mortality was compared with predicted cumulative risk-adjusted perioperative surgical mortality based on logistic European System for Cardiac Operative Risk Evaluation. One-year clinical follow-up was completed in all patients. The overall major adverse cardiac event rate at 1 year was 34.3%, reflecting the high-risk profile of the patient population. Twelve patients (8%) experienced an acute myocardial infarction and 16 (11%) underwent target lesion revascularization. In 31 patients (22%) who died during the first year, median logistic European System for Cardiac Operative Risk Evaluation was 30%. Calculated RRs showed significantly lower 30-day mortality using PCI compared with predicted surgical mortality (RR 0.54, 95% confidence interval 0.31 to 0.86). Angiographic follow-up in 90 of the 118 patients alive at 6 months showed binary restenosis of 6% in patients treated with drug-eluting stents versus 29% in patients receiving bare-metal stents (p < or =0.01). In conclusion, PCI for unprotected LMCA disease was associated with acceptable short- and medium-term outcomes in patients at low to intermediate risk of bypass surgery. Mortality remains high in very high-risk patients unsuitable for surgery. However, in selected indications, PCI of the LMCA can offer an alternative to surgery, especially when using drug-eluting stents.     

Longitudinal Effects of Syndemics on ART Non-adherence Among Sexual Minority Men

This study examined longitudinally the additive effect of syndemics, or co-occurring psychosocial problems, on antiretroviral treatment (ART) non-adherence among 390 HIV-positive sexual minority men. Participants completed measures of ART adherence (reduced to a non-adherence score using exploratory factor analysis) and six syndemic conditions. We employed multilevel modeling with the number of syndemics as a longitudinal predictor of non-adherence, and logistic regression with baseline syndemics predicting follow up viral load. Number of syndemics was a significant longitudinal predictor of non-adherence, with each additional syndemic associated with a 0.13 increase in non-adherence (p?=?0.004). Each additional syndemic was also associated with 1.27 greater odds of detectable viral load (p?=?0.002). Among HIV-positive sexual minority men in this sample, more syndemics were associated with lower ART adherence and greater odds of detectable viral load, suggesting the need for behavioral intervention to facilitate care for this population.