Efficacy of low-dose interferon with antiretroviral therapy in Kaposi's sarcoma: a randomized phase II AIDS clinical trials group study.

We wished to evaluate the efficacy and safety of a low and an intermediate daily dose of interferon-alpha2b (IFN-alpha2b) with didanosine in patients with acquired immunodeficiency syndrome (AIDS)-associated Kaposi's sarcoma (KS). HIV-seropositive subjects with biopsy-confirmed cutaneous KS were randomized to receive either a low (1 million IU) or an intermediate (10 million IU) dose of IFN-alpha2b once daily with twice daily doses of didanosine. Treatment assignment was stratified by CD4 count. Response, toxicity, changes in CD4 counts, and survival were evaluated. Sixty-eight eligible subjects were accrued, 35 to low-dose and 33 to intermediate-dose IFN-alpha2b. The response rate was 40% in the low-dose group (95% CI, 24-58) and 55% in the intermediate-dose group (95% CI, 36-72) (p = 0.338). The median response duration was approximately 110 weeks in both groups. Intermediate-dose IFN induced grade 3/4 neutropenia more often (21% vs. 3%, p = 0.048) and grade 3/4 toxicity faster (p = 0.0231) and necessitated treatment discontinuation earlier for drug-related toxicities (p = 0.0416) than low-dose IFN. There were no significant differences in survival between the treatment groups. Baseline CD4 count was the only significant factor predicting response. Once-daily low-dose and intermediate-dose IFN-alpha2b induced similar response rates, which were achieved without optimal antiretroviral therapy. The slightly higher response rate in the intermediate-dose group was offset by its significantly poorer tolerance. These findings justify the use of lower, well-tolerated IFN doses for treatment of KS with currently used antiretroviral regimens.     

Breast hamartoma: a mammographic diagnosis

The mammographic appearance of breast hamartoma, a benign cause of a breast mass, is characteristic. We present four cases from the University of Virginia to review the mammographic, pathologic, and clinical features of this unusual entity.     

Delta 9-tetrahydrocannabinol enhances presynaptic dopamine efflux in medial prefrontal cortex

Acute administration of 1.0-2.0 mg/kg delta 9-tetrahydrocannabinol (delta 9-THC) increased presynaptic dopamine (DA) efflux in the medial prefrontal cortex of rats, as measured by intracerebral microdialysis in awake, behaving rats. These data are congruent with suggestions that (1) marijuana's euphorigenic effects and abuse potential may be related to augmentation of presynaptic DA mechanisms, and (2) the medial prefrontal cortex may be an important site of action for drugs of abuse in general and for delta 9-THC in particular.     

Three-dimensional structure of a membrane-containing virus.

The structure of Sindbis virus was determined by electron cryomicroscopy. The virion contains two icosahedral shells of viral-encoded proteins separated by a membrane bilayer of cellular origin. The three-dimensional structure of the ice-embedded intact Sindbis virus, reconstructed from electron images, unambiguously shows that proteins in both shells are arranged with the same icosahedral lattice of triangulation number T = 4. These studies also provide structural evidence of contact between the glycoprotein and the nucleocapsid protein across the membrane bilayer. The structural organization of Sindbis virus has profound implications for the morphogenesis of the alphaviruses. The observed interactions confirm stoichiometric and specific protein associations that may be crucial for virion stability and predict a mechanism for assembly.     

Outcome of hospitalized patients with COVID-19 pneumonia treated with high-dose immunoglobulin therapy in a prospective case series

1. Download : Download high-res image (88KB)
2. Download : Download full-size image

     

P-cadherin expression is associated with high-grade ductal carcinoma in situ of the breast

Cadherins are calcium-dependent cell-cell adhesion glycoproteins, separated into several subclasses with distinct adhesive specificities and tissue distribution, which play an important role in many cellular events. We analyse the expression of E-, N- and P-cadherin in a series of ductal carcinoma in situ (DCIS) of the breast, since this disease represents a heterogeneous group, with different risks of progression to invasive breast carcinoma. We also studied the correlation between cadherin expression and DCIS classification systems, namely the Van Nuys and the Holland et al. classification, this latter based on cytonuclear differentiation and cell polarity. Our results showed that, regardless the classification applied, P-cadherin expression is strongly associated with high histological grade of DCIS (P=0.0047) and lack of estrogen receptors (P=0.0008). The use of Holland et al. classification showed a significant correlation between P-cadherin expression and decreased cell polarity (P=0.01). In conclusion, P-cadherin expression seems to be more relevant in DCIS pathogenesis than the altered expression of any other cadherin, including the decrease of E-cadherin expression.     

Conformational changes in Sindbis virions resulting from exposure to low pH and interactions with cells suggest that cell penetration may occur at the cell surface in the absence of membrane fusion

Alphaviruses have the ability to induce cell-cell fusion after exposure to acid pH. This observation has served as an article of proof that these membrane-containing viruses infect cells by fusion of the virus membrane with a host cell membrane upon exposure to acid pH after incorporation into a cell endosome. We have investigated the requirements for the induction of virus-mediated, low pH-induced cell-cell fusion and cell-virus fusion. We have correlated the pH requirements for this process to structural changes they produce in the virus by electron cryo-microscopy. We found that exposure to acid pH was required to establish conditions for membrane fusion but that membrane fusion did not occur until return to neutral pH. Electron cryo-microscopy revealed dramatic changes in the structure of the virion as it was moved to acid pH and then returned to neutral pH. None of these treatments resulted in the disassembly of the virus protein icosahedral shell that is a requisite for the process of virus membrane-cell membrane fusion. The appearance of a prominent protruding structure upon exposure to acid pH and its disappearance upon return to neutral pH suggested that the production of a "pore"-like structure at the fivefold axis may facilitate cell penetration as has been proposed for polio (J. Virol. 74 (2000) 1342) and human rhino virus (Mol. Cell 10 (2002) 317). This transient structural change also provided an explanation for how membrane fusion occurs after return to neutral pH. Examination of virus-cell complexes at neutral pH supported the contention that infection occurs at the cell surface at neutral pH by the production of a virus structure that breaches the plasma membrane bilayer. These data suggest an alternative route of infection for Sindbis virus that occurs by a process that does not involve membrane fusion and does not require disassembly of the virus protein shell.     

The association of Hospital Medicare beneficiary payer-mix,national quality rankings and outcomes following hepatopancreatic surgery

IntroductionWe sought to determine the impact of payer-mix on post-operative outcomes among Medicare beneficiaries following hepatopancreatic surgery.MethodsMedicare beneficiaries who underwent hepatopancreatic surgery were identified. Hospital quality markers were obtained from the Hospital General Information dataset. Hospitals were dichotomized (low/average vs. high) based on Medicare patient days versus all patient days irrespective of payer type.ResultsHigh Medicare patient-mix hospitals were more likely to be ranked higher than the national average relative to safety of care (29.4% vs. 38.1%) and timeliness of care (15.4% vs. 26.3%) versus low burden Medicare hospitals (both p < 0.001). However, Medicare beneficiaries who had hepatopancreatic surgery at a high Medicare patient-mix hospital were at higher risk of a complication (OR = 1.13, 95%CI 1.04–1.22), and death within 30-days (OR = 1.37, 95%CI 1.23–1.53) following surgery.ConclusionWhile hospitals caring for higher numbers of Medicare beneficiaries generally performed better on CMS quality indicators, these rankings did not equate to improved post-operative outcomes.     

Pheromones and Same-Sex Sexual Behavior

Archives of Sexual Behavior -