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S Buchbinder

Publications and source records attributed to S Buchbinder.

54 records · Page 3Linked to original sources
PubMed1998

Mammography in the evaluation of masses in breasts reconstructed with TRAM flaps.

Patients with transverse rectus abdominis musculocutaneous (TRAM) flaps may develop physical findings, such as palpable masses, irregularities, and areas of increased tenderness that are suggestive of fat necrosis or recurrent malignancy. The purpose of this study was to evaluate these findings with mammography in an attempt to rule out recurrent malignancy in the autogenously reconstructed breast. Fifteen patients on whom mammography was performed as an aid in the evaluation of suspicious post-TRAM flap findings were reviewed. Common mammographic findings included calcifications believed to demonstrate fat necrosis, benign dermal calcifications, calcified hematoma, and clustered microcalcifications. Areas of increased or decreased density without calcifications were also identified and appeared to be related to surgical changes and fat necrosis. Twenty percent of patients had clustered microcalcifications, and 20% had detectable masses on mammography. One patient had a suspicious mass associated with clustered microcalcifications, leading to a biopsy that revealed fat necrosis. The majority of findings were consistent with normal fat within the TRAM flaps. This study supports mammography as a useful diagnostic tool in patients who have undergone TRAM flap breast reconstruction and who present postoperatively with suspicious physical findings.

Breast Neoplasms↗
PubMed1997

Assessment of the changing willingness to participate in phase III HIV vaccine trials among men who have sex with men.

This paper describes the willingness of 1267 men who have sex with men (MSM) enrolled in a prospective HIV vaccine preparedness study from Chicago, Denver, and San Francisco to enroll in HIV vaccine efficacy trials. Respondents were interviewed at baseline and followed-up at 6, 12, and 18 months. At each visit respondents were tested for HIV antibodies using enzyme-linked immunosorbent assay (ELISA) testing with Western blot confirmation. Over 18 months, the annualized HIV seroincidence of this cohort was 2.4%. At baseline, 37% of the men reported that they would be "definitely" willing to participate in an HIV vaccine efficacy trial; however, this dropped to 21% at 12 months and remained stable at 18 months. Greater willingness to participate (WTP) was related to lower education, engaging in HIV risk behavior, living in Denver, white ethnicity, and older age. Changing WTP suggests that the decision to participate in HIV vaccine efficacy trials may be complex and dynamic and take an extended time. These data underscore the importance of informed consent and raise questions regarding the influence of decision-making processes on HIV vaccine efficacy trial design, compliance, and validity.

AIDS Vaccines↗
PubMed1997

Heterozygosity for a defective gene for CC chemokine receptor 5 is not the sole determinant for the immunologic and virologic phenotype of HIV-infected long-term nonprogressors.

HIV-1-infected long-term nonprogressors are a heterogeneous group of individuals with regard to immunologic and virologic markers of HIV-1 disease. CC chemokine receptor 5 (CCR5) has recently been identified as an important coreceptor for HIV-1 entry into CD4+ T cells. A mutant allele of CCR5 confers a high degree of resistance to HIV-1 infection in homozygous individuals and partial protection against HIV disease progression in heterozygotes. The frequency of CCR5 heterozygotes is increased among HIV-1- infected long-term nonprogressors compared with progressors; however, the host defense mechanisms responsible for nonprogression in CCR5 heterozygotes are unknown. We hypothesized that nonprogressors who were heterozygous for the mutant CCR5 gene might define a subgroup of nonprogressors with higher CD4+ T cell counts and lower viral load compared with CCR5 wild-type nonprogressors. However, in a cohort of 33 HIV-1-infected long-term nonprogressors, those who were heterozygous for the mutant CCR5 gene were indistinguishable from CCR5 wild-type nonprogressors with regard to all measured immunologic and virologic parameters. Although epidemiologic data support a role for the mutant CCR5 allele in the determination of the state of long-term nonprogression in some HIV-1- infected individuals, it is not the only determinant. Furthermore, long-term nonprogressors with the wild-type CCR5 genotype are indistinguishable from heterozygotes from an immunologic and virologic standpoint.

Adult↗
PubMed1997

Contrasting genetic influence of CCR2 and CCR5 variants on HIV-1 infection and disease progression. Hemophilia Growth and Development Study (HGDS), Multicenter AIDS Cohort Study (MACS), Multicenter Hemophilia Cohort Study (MHCS), San Francisco City Cohort (SFCC), ALIVE Study.

The critical role of chemokine receptors (CCR5 and CXCR4) in human immunodeficiency virus-type 1 (HIV-1) infection and pathogenesis prompted a search for polymorphisms in other chemokine receptor genes that mediate HIV-1 disease progression. A mutation (CCR2-64I) within the first transmembrane region of the CCR2 chemokine and HIV-1 receptor gene is described that occurred at an allele frequency of 10 to 15 percent among Caucasians and African Americans. Genetic association analysis of five acquired immunodeficiency syndrome (AIDS) cohorts (3003 patients) revealed that although CCR2-64I exerts no influence on the incidence of HIV-1 infection, HIV-1-infected individuals carrying the CCR2-64I allele progressed to AIDS 2 to 4 years later than individuals homozygous for the common allele. Because CCR2-64I occurs invariably on a CCR5-+-bearing chromosomal haplotype, the independent effects of CCR5-Delta32 (which also delays AIDS onset) and CCR2-64I were determined. An estimated 38 to 45 percent of AIDS patients whose disease progresses rapidly (less than 3 years until onset of AIDS symptoms after HIV-1 exposure) can be attributed to their CCR2-+/+ or CCR5-+/+ genotype, whereas the survival of 28 to 29 percent of long-term survivors, who avoid AIDS for 16 years or more, can be explained by a mutant genotype for CCR2 or CCR5.

Acquired Immunodeficiency Syndrome↗
PubMed1996

A factorial survey study to assess the acceptability of HIV vaccine trial designs.

To aid in the design of human immunodeficiency virus (HIV) vaccine trials that maximize volunteer participation, factorial surveys were administered to 73 gay men who were participants in a larger study assessing HIV vaccine trial feasibility. Factorial surveys are "vignettes" that are randomly constructed through the combination of descriptive statements (dimensions) that reflect essential features. In this study, the dimensions define components of clinical trials to assess the efficacy of hypothetical HIV vaccines. Regression analysis shows that anticipated participation was decreased by a sustained vaccine-induced antibody response lasting 3 years, absence of gay men as research subjects in earlier phase trials for the products being tested, and rectal vaccine administration. Three years of scientific experience with the vaccine encouraged participation. We conclude that willingness to participate in vaccine trials varies systematically with some of their characteristics. Where there are design alternatives for identified negative components, these should be considered. If this is not possible, options for decreasing aversion to such features will need to be evaluated, including appropriate education regarding both the benefits and the risks associated with negatively evaluated features.

AIDS Vaccines↗
PubMed1996

Recognition of the highly conserved YMDD region in the human immunodeficiency virus type 1 reverse transcriptase by HLA-A2-restricted cytotoxic T lymphocytes from an asymptomatic long-term nonprogressor.

The human immunodeficiency virus (HIV) type 1 reverse transcriptase (RT) is an important target for therapeutic intervention and for HIV-1-specific cytotoxic T lymphocytes (CTL). An HLA-A2-restricted CTL epitope containing the sequence YMDD, which is highly conserved among human and animal retroviruses and essential for function of the RNA-dependent DNA polymerase, is identified. The drug resistance mutation at RT amino acid 184 (M184V), associated with (-)-2'-deoxy-3'-thiacytidine (lamivudine), (-)-2'-deoxy-5-fluoro-3'-thiacytidine (FTC), and dideoxyinosine resistance, is located within this epitope and abolishes recognition by an established CTL response. This study demonstrates that the CTL response may target functionally relevant regions of the RT protein and suggests drug therapy may select for viral variants with altered susceptibility to established cellular immune responses.

Amino Acid Sequence↗
PubMed1994

Preparations for AIDS vaccine trials. Developing brief valid screening instruments for HIV-related sexual risk behavior among gay and bisexual men.

Enrolling and tracking cohorts for HIV vaccine efficacy trials requires that participants disclose behaviors that place them at risk for exposure to HIV. Brief screening procedures have been suggested for this purpose. In a previous study gay and bisexual men in three U.S. cities reported unprotected anal intercourse on a brief screening instrument. Screen reports were compared to subsequent in-depth, face-to-face interview data; 29% of the men who reported unprotected anal intercourse during the interview failed to disclose this behavior during screening. For recruitment into an HIV vaccine feasibility study at the same study sites, screening procedures were modified to encourage accurate reporting: to lessen stigma, low risk as well as high risk sexual behaviors were assessed, and screens were administered by trained study staff who presented it as a tool for understanding the gay community. Failures to disclose risk decreased to 18%, a rate that, while lower than in the previous study, remains high. Men less likely to disclose unprotected sex during the screen engaged in fewer high risk sexual behaviors, had more stringent norms regarding sexual safety, and were less identified with the gay community than were men who disclosed unprotected sex. Failure to disclose risk may have significant implications for participant selection and behavior tracking during vaccine trials. More systematic assessments that are sensitive to target communities may facilitate disclosure.

AIDS Vaccines↗
PubMed1991

Progressive multifocal leukoencephalopathy in persons infected with human immunodeficiency virus, San Francisco, 1981-1989.

Progressive multifocal leukoencephalopathy (PML), a rare neurological disease, has been sporadically reported in persons infected with human immunodeficiency virus (HIV), the causative agent of acquired immune deficiency syndrome (AIDS). From January 1981 through February 1989, in San Francisco, we identified 94 HIV-infected persons with PML, of whom 48 (51%) were pathologically confirmed (as required for AIDS case reporting). These 48 patients were significantly older when diagnosed with AIDS (20% older than 50 years) than patients with AIDS without PML. The remaining 46 (49%) patients, diagnosed clinically and by neuroimaging, did not differ significantly from definitive patients in demographic or survival characteristics after PML diagnosis. We detected antibodies to JC virus, the causative agent of PML, in 9 of 14 (64%) AIDS-related patients with PML, and in 9 of 14 (64%) matched control subjects, suggesting that determination of JC virus antibody status before AIDS diagnosis does not reliably indicate which patients will contract PML. Our study shows that the proportion of patients with AIDS who contracted PML remained stable between 1981 and 1988, but increased in the first 2 months of 1989. Our findings further indicate that PML in HIV-infected patients may be underestimated by as much as 50%.

Adolescent↗
PubMed1991

Outcome of hepatitis B virus infection in homosexual men and its relation to prior human immunodeficiency virus infection.

To investigate the effect of human immunodeficiency virus type 1 (HIV-1) infection on subsequent hepatitis B virus (HBV) infection, HIV antibody was sought in homosexual men who developed HBV infection during a hepatitis B vaccine trial. Among 134 unvaccinated HIV-1-negative men, 7% became HBV carriers, 64% had viremia, and 42% had clinical illness. Among vaccinated HIV-1-negative men, HBV infection severity decreased with number of vaccine doses administered. When adjusted for prior hepatitis B vaccination status, persons with HIV-1 infection preceding HBV infection had a significantly higher risk of developing HBV carriage, viremia, prolonged ALT elevation, and clinical illness. Among HIV-1-infected men, the risk of HBV carriage was increased in unvaccinated persons (21%) and those who failed to respond to vaccination (31%) and further increased in those who received vaccine doses at the time they developed new HBV infection (56%-80%), suggesting inactivated hepatitis B vaccine may temporarily impair the immune response to HBV infection in HIV-1-infected persons. HIV-1 infection was also associated with reduced alanine aminotransferase elevations during the first 36 months of follow-up of men who became HBV carriers.

Alanine Transaminase↗
PubMed1990

Invited review: peripheral neuropathy in Sjogren's syndrome.

Our experience and review of the literature reveal that Sjogren's syndrome (SS) is an important, poorly recognized cause of peripheral neuropathy. Several forms of peripheral nerve dysfunction occur in SS including trigeminal sensory neuropathy, mononeuropathy multiplex, distal sensory neuropathy, distal sensorimotor peripheral neuropathy and a pure sensory neuronopathy syndrome. Rarely, chronic relapsing inflammatory polyneuropathy and multiple cranial neuropathies appear. Clinical evidence of glandular involvement is often minimal or absent when patients with SS develop peripheral neuropathy; and the diagnosis of the underlying condition is elusive. We review clinical and laboratory features of this disorder and suggest appropriate evaluation of patients with neuropathy and suspected SS.

Adult↗
PubMed1990

SPECT dual-energy-window Compton correction: scatter multiplier required for quantification.

The dual-energy window Compton-scattering correction technique is defined here especially for accurate quantification of focal regions having higher than average uptake. The quantification is relative to a known-activity reference source. The scatter multiplier ("k" value) is determined for a radioactive 99mTc sphere on or off the axis of a cylinder containing water with or without background. Both maximum likelihood and filtered-backprojection reconstruction are employed. Either projections or tomograms are corrected. With tight regions of interest, there is a tendency for the requisite "k" value to be slightly lower as the diameter of the cylinder is increased. Neither sphere location nor background perturbs "k", however, so a constant value is a good, first approximation. Then a two-sphere validation test yields an accuracy of 8% with subtracted-tomograms ("k" = 1.30) and 2% with subtracted-projections ("k" = 1.20). With a reference-source region of interest which is four times larger, "k" is reduced and also now depends on background. Although equivalent quantitatively, maximum likelihood is preferable to filtered backprojection with Chang attenuation correction since it produces a less-noisy image.

Algorithms↗
PubMedDate not supplied

Ruptured hepatic artery aneurysms in a patient with systemic lupus erythematosus: case report.

Spontaneous hemorrhage caused by ruptured left hepatic artery branch aneurysms occurred in a 49-year-old man with systemic lupus erythematosus. Following evaluation by computerized tomography and angiography, transcatheter embolization of the left hepatic artery resulted in hemostasis. The various etiologies of hepatic artery aneurysms are discussed. This case demonstrates that systemic lupus erythematosus must be considered in the differential diagnosis of hepatic artery aneurysms and spontaneous hepatic hemorrhage.

Aneurysm↗