Biomedical subjects
N Luban
Publications and source records attributed to N Luban.
Phenotypic expressions of CCR5-delta32/delta32 homozygosity.
OBJECTIVE: As blockade of CC-chemokine receptor 5 (CCR5) has been proposed as therapy for HIV-1, we examined whether the CCR5-delta32/delta32 homozygous genotype has phenotypic expressions other than those related to HIV-1. DESIGN: Study subjects were white homosexual men or men with hemophilia who were not infected with HIV-1. In this study, 15 CCR5-delta32/delta32 homozygotes were compared with 201 CCR5 wild-type (+/+) subjects for a wide range of clinical conditions and laboratory assay results ascertained during prospective cohort studies and routine clinical care. CCR5-delta32 genotype was determined by polymerase chain reaction, followed by single-stranded conformational polymorphism analysis. RESULTS: Hypertension and conditions attributable to hemophilia were the only diagnoses frequently found in clinical records of CCR5-delta32/delta32 study subjects. Based on blood pressure measurement and treatment history, CCR5-delta32/delta32 homozygotes had a 2.8-fold higher prevalence of hypertension than age-matched CCR5-+/+ study subjects (95% confidence interval [CI], 1.2-6.4; p = .01); none of the homozygotes had severe hypertension. Hematologic measures were generally similar across the genotypes, but total lymphocyte counts were approximately 20% higher in CCR5-delta32/delta32 study subjects than in CCR5-+/+ study subjects (p < .05). Among patients with hemophilia who were infected with hepatitis C virus (HCV), mean alanine aminotransferase levels were 117% higher among CCR5-delta32/delta32 homozygotes (p < .05), but serum HCV levels did not differ by CCR5-delta32 genotype. CCR5-delta32/delta32 homozygous study subjects had a lower prevalence of antibodies to measles virus than those with other genotypes, but this association was not confirmed in a group of blood donors. The prevalence of antibodies to nine other common viruses, HBV, and HCV was not related to CCR5 genotype. CONCLUSIONS: CCR5-delta32/delta32 homozygotes are generally similar to wild-type persons. Confirmatory investigations are required to determine whether hypertension, increased lymphocyte counts, and higher hepatic enzyme levels in the presence of HCV infection represent true phenotypic expressions of this genotype. CCR5-delta32/delta32 homozygosity does not provide broad protection against viral infections.
Protease inhibitor and triple-drug therapy: cellular immune parameters are not restored in pediatric AIDS patients after 6 months of treatment.
OBJECTIVE: To assess whether treatment of HIV-positive children by antiretroviral drugs for a 6-month period would improve immune function significantly. DESIGN AND METHODS: Immunological assessment of 89 HIV-positive children who received protease inhibitor monotherapy for 12-16 weeks as part of phase I/II studies, followed by triple antiretroviral therapy for an additional 12 weeks, was conducted. Immunological parameters were assessed in vitro at four time points (at enrollment, at weeks 2-4, at weeks 12-16, and at weeks 24-28). Assessments included: cytokine production by monocytes, T-cell proliferation to mitogen or recall antigens (including an HIV antigen) and apoptotic cell death. Plasma levels of tumor necrosis factor (TNF)-alpha and soluble TNF receptor (sTNF-R) were also measured, in addition to CD4+ T-lymphocyte counts and viral load. In addition, limited analyses were performed on samples from 17 children after 120 weeks of therapy, including 104 weeks of triple therapy. RESULTS: At enrollment, the 89 children exhibited severe immune defects. Antiretroviral therapy raised CD4+ T-lymphocyte counts significantly and decreased viral loads. In contrast, the in vitro immune parameters studied were not improved, except for plasma levels of sTNF-RII which decreased in parallel with the decrease in viral load. In addition, there was a trend towards increased skin test reactivity for the ritonavir-treated children. No differences were seen in the immune parameters whether the patients were treated with mono- or triple therapy. Results obtained after 120 weeks of therapy demonstrated that defective interleukin-12 production was not restored by long-term therapy. CONCLUSIONS: After 6 months of therapy, with the exception of decreased sTNF-RII levels, and a trend towards increased skin test reactivity, restoration of several defective cellular immune responses did not occur despite significantly decreased viral loads and increased CD4+ T-lymphocyte counts.
Laboratory test differences associated with HTLV-I and HTLV-II infection. Retrovirus Epidemiology Donor Study Investigators.
Reports of laboratory abnormalities associated with HTLV-I and HTLV-II infection are inconsistent. We assessed complete blood counts and selected serum chemistry measures at enrollment in a cohort of 153 HTLV-I-seropositive, 386 HTLV-II-seropositive, and 795 HTLV-seronegative blood donors. Linear and logistic regression were used to adjust for potential confounding variables including age, gender, race/ethnicity, education level, blood center, and injection drug use. Compared with seronegative donors, absolute lymphocyte counts were 6% and 10% higher, on average, in HTLV-I-infected (p = .03) and HTLV-II-infected (p = .0001) donors, respectively. HTLV-I- and HTLV-II-seropositive donors had, on average, 17,630 (p = .003) and 15,160 (p = .0005) more platelets, respectively. HTLV-I-infected donors also had an average of 30 fewer eosinophils/microl (p = .003) and a slightly higher level of lactic dehydrogenase (p = .05). HTLV-II-infected subjects had on average, an 11% decrease in creatine kinase (p = .006), a minor increase in mean corpuscular volume (p = .01), and a slightly lower serum calcium level (p = .0005). These results indicate that both HTLV-I and HTLV-II may raise levels of lymphocytes and platelets by unknown mechanisms. Lower eosinophil counts may be related to the increased susceptibility of HTLV-I-infected subjects to parasitic diseases.
Serum HIV-1 RNA levels and time to development of AIDS in the Multicenter Hemophilia Cohort Study.
OBJECTIVE: To determine if the long-term incidence of the acquired immunodeficiency syndrome (AIDS) is related to human immunodeficiency virus type 1 (HIV-1) RNA levels measured early in HIV-1 infection. DESIGN: Epidemiologic cohort study. SETTING: Five hemophilia treatment centers in the United States. SUBJECTS: A total of 165 subjects with hemophilia and HIV-1 infection (age at HIV-1 seroconversion, 1-66 years) followed from 1979 to 1995. METHODS: The HIV-1 RNA level was measured by polymerase chain reaction over a range of 200 to 1 million or more HIV-1 RNA copies/mL in archived serum specimens collected 12 to 36 months (median, 27 months) after the estimated date of HIV-1 seroconversion. Kaplan-Meier methods were used to examine the risk of AIDS and proportional hazards models were used to estimate relative hazards. RESULTS: The HIV-1 RNA values were similar in subjects younger than 17 years at seroconversion (median, 5214 copies/mL) and those 18 to 34 years old (median, 4693 copies/mL), but higher in those 35 years or older (median, 12069 copies/mL) (P = .02 compared with each younger group). At 10 years after seroconversion, the proportions of subjects with AIDS were 72% among subjects with 100,000 or more HIV-1 RNA copies/mL measured 12 to 36 months after HIV-1 seroconversion (n = 9), 52% among subjects with 10,000 to 99,999 copies/mL (n = 55), 22% among subjects with 1000 to 9,999 copies/mL (n = 82), and 0% among subjects with fewer than 1000 copies/mL (n = 19) (P < .001). The age-adjusted relative hazard for AIDS for subjects with 10,000 or more copies/mL was 14.3 (95% confidence interval, 1.9-105.6) compared with subjects with fewer than 1000 copies/mL. CONCLUSIONS: The HIV-1 RNA level during early chronic HIV-1 infection is a strong, age-independent predictor of clinical outcome; low levels define persons with a high probability of long-term AIDS-free survival.
Postoperative apnoea in former preterm infants: does anaemia increase the risk?
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Sp alpha I/65: a new variant of the alpha subunit of spectrin in hereditary elliptocytosis.
Two molecular defects involving the spectrin heterodimer (SpD) contact site of the alpha chain (the alpha I domain) were previously identified using limited tryptic digestion followed by two-dimensional isoelectric focusing/sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Both are characterized by atypical peptide maps which reveal a marked decrease of the 80,000-dalton alpha I domain and a formation of new major peptides of either 74,000 (Sp alpha I/74) or 46,000 (Sp alpha I/46) daltons. We now report a third variant of the spectrin alpha chain, designated Sp alpha I/65, in three unrelated black families. In all three probands, the percentage of SpD in the low ionic strength (O degrees C) membrane extracts was increased to 19% to 32%. One- and two-dimensional electrophoretic separations of limited tryptic digests of spectrin from all three probands revealed a decrease of the alpha I domain of spectrin and the concomitant appearance of peptides at 65,000 daltons and isoelectric points ranging from 5.2 to 5.3. The abnormal 65,000-dalton peptides could be stained with an antiserum which had been raised against the alpha I domain, indicating that it was derived from the alpha I domain.
Benign hepatocellular tumors in the young. A clinicopathologic spectrum.
Hepatic tumors unassociated with cirrhosis were encountered in seven patients aged 10 to 19 years. Four patients had received androgens for aplastic anemia. Two patients had transfusional hemosiderosis. One patient had had a renal transplant 2 1/2 years ago. Two patients are alive at 2 3/4 and 2 1/2 years after surgical resections. Nodules were found at autopsy in the others. The tumors were well differentiated and, in the androgen-related cases, differed from the others in the following features: canalicular bile retention, mild nuclear atypia, and acinar formation. No mitoses, vascular invasion, or metastatic tumor were evident. The clinical setting was variable; different factors, including iron overload and androgen therapy, played a role in the development of tumor. Although the androgen-related cases showed mild cellular atypia, biologic evidence of malignancy was lacking as in most previous reports.
Giant platelet disorders in African-American children misdiagnosed as idiopathic thrombocytopenic purpura.
A retrospective chart review of six African-American children with a diagnosis of macrothrombocytopenias (MTCP) was performed to evaluate the accuracy of their diagnosis. The following was diagnosed in the six children with MTCP: Fechtner syndrome (two children), Sebastian syndrome (one child), and unnamed MTCP (three children). In five families, chronic idiopathic thrombocytopenic purpura (ITP) was diagnosed in the propositus, which resulted in therapy using steroids, intravenous immunoglobulin (IVIG), and in one case splenectomy. Bleeding symptoms were generally mild. All six patients had thrombocytopenia ranging from 10 to 125 x 10(9)/L with mean platelet volume of 8 to 20 fL. Bleeding times were abnormal in two of three patients, and platelet aggregation was abnormal in three of four patients tested. Bone marrow aspirates were reported as increased megakaryocytes in the three patients on whom the procedure was performed. Ultrastructural morphology of platelets and leukocytes was performed in all six patients demonstrating giant platelets in all six patients and leukocyte inclusions in three patients. Differentiating MTCP from the more common ITP can be difficult but important in avoiding unnecessary diagnostic studies and potentially harmful therapy associated with ITP.