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Biomedical subjects

J McFarland

Publications and source records attributed to J McFarland.

At least 19 recordsLinked to original sources
PubMed2004

Effect of an HIV counseling and testing program on AIDS-related knowledge and practices in tuberculosis clinics in Abidjan, Côte d'Ivoire.

SETTING: Two out-patient tuberculosis treatment centers, Abidjan, Côte d'Ivoire. OBJECTIVE: To assess the effect of a human immunodeficiency virus (HIV) counseling and testing program on acquired immune-deficiency syndrome (AIDS) related knowledge and behaviors among persons with newly diagnosed tuberculosis. DESIGN: Since 1994, patients with newly diagnosed tuberculosis have received individual or group HIV pretest counseling, informed consent, free HIV testing for those who consent, and post test counseling. From January 1995 through August 1996 in Abidjan's two largest tuberculosis clinics, knowledge and beliefs about HIV/AIDS were assessed before and immediately after the group pretest sessions, and again 4 months later. RESULTS: Prior to pretest counseling, 68.9% and 68.0% of the 559 enrolled subjects could correctly identify five modes of HIV transmission and five modes of HIV prevention. These proportions increased significantly immediately after pretest counseling (90.0%, 86.6%, respectively), and remained higher 4 months later (83.7%, 87.7%) (all P < 0.01). Among men, consistent condom use during the preceding 4 months with a partner who was not a commercial sex worker increased from 9.9% at enrollment to 23.6% at the 4-month visit (P = 0.001), but not for women (6.3% vs. 9.5%, P = 0.40). CONCLUSIONS: An HIV pretest counseling program conducted in an out-patient tuberculosis clinic was well accepted, and significantly increased the level of HIV/AIDS knowledge and, among men, self-reported condom use.

Acquired Immunodeficiency Syndrome↗
PubMed2002

Pathophysiology of platelet destruction in immune (idiopathic) thrombocytopenic purpura.

The mechanism of platelet destruction in immune (idiopathic) thrombocytopenic purpura (ITP) is thought to involve production of autoantibody to platelet surface antigens. Once coated with antibody, circulating platelets undergo sequestration via interaction with Fc receptors of macrophages in the reticuloendothelial system. A number of questions remain about the mechanism of platelet destruction in this disease: 1) What is the nature of the stimulus to the immune system that generates antiplatelet antibodies? 2) What is the role of interactions between T-helper lymphocytes and antigen-presenting cells in ITP? 3) What role, if any, is played by the targeting of single or multiple platelet surface glycoproteins by the autoimmune response? 4) Is the site of platelet destruction, intravascular or extravascular, or the state of activation of platelets important in the destruction of platelets?

Antibody Formation↗
PubMed2000

Human immunodeficiency virus (HIV) subtype surveillance of African-born persons at risk for group O and group N HIV infections in the United States.

A population-based surveillance registry was used to identify human immunodeficiency virus (HIV)-infected persons in the United States at increased risk for group O and group N infections (those born in or near African countries where group O infection has been reported). Of 155 eligible subjects, 37 gave samples. By phylogenetic and serologic analysis, 32 were infected with group M (16 with subtype A, 5 with B, 7 with C, and 1 each with subtypes D, F2, G, and recombinant A/J) and 2 with group O but none with group N virus. For 3, samples could not be typed by serology or amplified by polymerase chain reaction using group M-, O-, or N-specific primers. In the United States, group O HIV infection is uncommon; no case of group N infection was found. African-born persons may have HIV strains typical of their birth country. Ongoing subtype surveillance may allow early identification of novel or emerging HIV strains.

Adult↗
PubMed1999

Persistently negative HIV-1 antibody enzyme immunoassay screening results for patients with HIV-1 infection and AIDS: serologic, clinical, and virologic results. Seronegative AIDS Clinical Study Group.

OBJECTIVE: To describe persons with HIV infection and AIDS but with persistently negative HIV antibody enzyme immunoassay (EIA) results. DESIGN: Surveillance for persons meeting a case definition for HIV-1-seronegative AIDS. SETTING: United States and Canada. PATIENTS: A total of eight patients with seronegative AIDS identified from July 1995 through September 1997. MAIN OUTCOME MEASURES: Clinical history of HIV disease, history of HIV test results, and CD4 cell counts from medical record review; results of testing with a panel of EIA for antibodies to HIV-1, and HIV-1 p24 antigen; and viral subtype. RESULTS: Negative HIV EIA results occurred at CD4 cell counts of 0-230 x 10(6)/l, and at HIV RNA concentrations of 105,000-7,943,000 copies/ml. Using a panel of HIV EIA on sera from three patients, none of the HIV EIA detected infection with HIV-1, and signal-to-cut-off ratios were < or = 0.8 or all test kits evaluated. Sera from five patients showed weak reactivity in some HIV EIA, but were non-reactive in other HIV EIA. All patients were infected with HIV-1 subtype B. CONCLUSIONS: Rarely, results of EIA tests for antibodies to HIV-1 may be persistently negative in some HIV-1 subtype B-infected persons with AIDS. Physicians treating patients with illnesses or CD4 cell counts suggestive of HIV infection, but for whom results of HIV EIA are negative, should consider p24 antigen, nucleic acid amplification, or viral culture testing to document the presence of HIV.

Acquired Immunodeficiency Syndrome↗
PubMed1998

Prophylaxis for opportunistic infections among HIV-infected patients receiving medical care.

In 1995 and 1997, the United States Public Health Service (USPHS) and the Infectious Disease Society of America (IDSA) published recommendations for primary prophylaxis of Pneumocystis carinii pneumonia (PCP), Mycobacterium avium complex (MAC), and toxoplasmosis in HIV-infected adults. We evaluated their implementation at four hospital-based HIV clinics in New York City in patients who initially met the CD4+ criterion for prophylaxis between January, 1995 and April, 1997. Medical records were reviewed at 6-month intervals to determine drugs prescribed. We identified 149 patients for the PCP sample, 130 for MAC, and 138 for toxoplasmosis. In the three samples, 91% were black and Hispanic, 75% to 81% were male, and 43% to 47% had a history of injection drug use (IDU); median age was between 39 and 40 years. PCP prophylaxis was prescribed during 93% of intervals and did not vary significantly by clinic or patient characteristics. Over the study period, MAC prophylaxis increased from 22% to 62%, and prescriptions for macrolides increased from 38% to 87% of all prescriptions. In the logistic regression analysis, prescription for MAC prophylaxis at any time during the study period was less likely in blacks compared with whites (odds ratio [OR] = .08; 95% confidence interval [CI] = .01, .52) and patients attending the clinic with the lowest rate of MAC prophylaxis (clinic D) compared with the clinic with the highest rate (clinic B; OR = .04; 95% CI = .01, .26). Toxoplasmosis prophylaxis was prescribed in 73% of intervals and did not differ significantly by antibody status (p = .42). Prescribing patterns were uniform across gender, HIV risk behavior, and age for PCP and MAC prophylaxis but differed by clinic and race for MAC prophylaxis. Trends in prophylaxis for opportunistic illnesses must continue to be monitored in light of the success of antiretroviral therapy in reducing the morbidity and mortality associated with HIV/AIDS.

AIDS-Related Opportunistic Infections↗
PubMed1997

One-tube method for complete HPA-1 genotyping by PCR using sequence-specific primers.

Human platelet antigens (HPA) can be targets for antibody responses that cause life-threatening thrombocytopenia following platelet transfusions or pregnancy. As an aid to diagnosis and prevention, serologic and DNA-based methods have been developed to type HPA. Of the DNA-based strategies, those using the polymerase chain reaction (PCR) are very sensitive, but often require processing of amplification products. Sequence-specific primers (SSP) in the PCR eliminate the need for extensive handling of reaction products beyond gel electrophoresis. However, current methods require a separate reaction for each allele being typed. In this report we describe a method to simultaneously and completely genotype both alleles of HPA-1 in a single PCR. In addition, because the absence of an amplification product might also show the failure of a SSP, we introduced a recombinant template that can only be amplified by the SSP, thus ensuring primer performance and the identified genotype.

Alleles↗
PubMed1996

Leucovorin and high-dose fluorouracil in metastatic prostate cancer. A phase II trial of the piedmont Oncology Association.

We performed a Phase II trial of oral leucovorin and high-dose fluorouracil (5FU) in hormone refractory patients with metastatic prostate cancer who had not had prior chemotherapy. 5FU was given as a 24-hour infusion at a dosage of 4 g/m2 and oral leucovorin at a dosage of 50 mg every 6 hours for four doses, starting with the infusion of 5FU. Fifteen patients were treated and three were not evaluable for response. There were no complete (CR) or partial responses (PR) in 12 evaluable patients (95% confidence interval for CR+PR of 0 to 26%). Three patients had stable disease and the remainder progressed. Toxicities were generally mild to moderate, but one patient died of sepsis while neutropenic. This dose and schedule of leucovorin and 5FU is not better than single-agent 5FU in patients with metastatic prostate cancer.

Aged↗
PubMed1994

Vincristine with high-dose etoposide in advanced breast cancer: a phase II trial of the Piedmont Oncology Association.

Vincristine (VCR) and etoposide (VP-16) have been shown to be synergistic in a murine model, and this combination was studied in a phase II trial. Eligibility required measurable disease, a performance status of 0-2, a life expectancy of > or = 2 months, an interval of at least 3 weeks since the receipt of previous radiation therapy or chemotherapy and recovery from related toxicity, no prior treatment with VCR or VP-16, and no more than two prior chemotherapy regimens (only one for treatment of metastatic disease). Treatment consisted of 0.5 mg i.v. (bolus) VCR followed by 200 mg/m2 VP-16 given over 2 h. Both drugs were given daily for 3 consecutive days every 3 weeks (total dose: VCR, 1.5 mg; VP-16, 600 mg/m2). A total of 18 patients with metastatic breast cancer were accured; 14 had adjuvant chemotherapy and 8 had chemotherapy for advanced disease. As judged by International Union Against Cancer (UICC) criteria, one complete response (CR) and three partial responses (PR) were obtained, for a CR + PR rate of 22% (95% confidence interval, 6%-48%). All responders had soft-tissue involvement only. Six patients had stable disease and 8 showed progression. The median time to treatment failure was 3.5 months, and the median survival from study entry was 8.3 months. The major toxicity was myelosuppression, with 9 patients (50%) experiencing a total WBC of < 1,000/mm3. Grade 2-3 neurologic toxicity was noted in 6 patients (33%) and grade 3 nausea and vomiting was noted in 5 (28%). The combination of VCR and VP-16 is active in advanced breast cancer but is not convincingly superior to either of these agents used alone.

Adult↗
PubMed1992

Diagnosis of hepatitis C virus (HCV) infection using an immunodominant chimeric polyprotein to capture circulating antibodies: reevaluation of the role of HCV in liver disease.

Structural and nonstructural regions of the HCV-encoded polyprotein have been expressed in recombinant yeast, bacteria, or insect cells and used to capture and measure reactive antibodies circulating in different individuals. The putative nucleocapsid protein (C) and nonstructural proteins 3-5 (NS3-NS5) were found to contain the most immunodominant epitopes. The NS3, NS4, and C regions were expressed in yeast in the form of a fused, chimeric polyprotein (C25) and a capture assay for reactive antibody was developed. This anti-C25 assay detects all previously identified HCV-seropositive cases and provides a substantially more sensitive diagnostic for both acute and chronic HCV infections than the current anti-C100-3 (NS4) assay. Anti-C25 was detected more frequently than anti-C100-3 in chronic, transfusion-associated non-A, non-B hepatitis patients from the United States (95% vs. 71%) and Japan (98% vs. 82%), in cryptogenic cirrhosis patients from the United States (62% vs. 28%), and in hepatitis B surface antigen-negative cases of hepatocellular carcinoma from Japan (83% vs. 63%). These data indicate that HCV has a greater role in these liver diseases than was previously thought. In volunteer United States blood donors sampled following the introduction of anti-C100-3 screening, the prevalence of anti-C25 and anti-C100-3 was 0.5% and 0.08%, respectively.

Antigens, Viral↗
PubMed1992

Antivinculin antibodies in sera of patients with immune thrombocytopenia and in sera of normal subjects.

We have characterized a 120-Kd antigen that frequently reacts with serum antibodies from patients with immune thrombocytopenia or normal subjects. Immunoblots made after two-dimensional nonreduced/reduced sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) or two-dimensional isoelectric focusing/SDS-PAGE demonstrated that this 120-Kd protein has the same molecular weight under nonreduced or reduced conditions, is not a surface protein, and has an isoelectric point (pl) of 6.4 to 6.5. From these data, one likely candidate is the intracellular platelet protein, vinculin. Monoclonal antivinculin antibody reacts with this 120-Kd protein, and purified human platelet vinculin is bound by antibodies that recognize the 120-Kd protein. Therefore, we conclude that this 120-Kd protein is identical to vinculin. Data obtained from a sensitive enzyme-linked immunosorbent assay demonstrate the presence of naturally occurring antivinculin antibodies in many normal sera. However, the incidence of antivinculin antibodies in patient sera (67%; 55 of 82 sera) is significantly (P less than .01) higher than that in normal sera (40%; 32 of 80 sera), and there is a significant difference (P less than .05) between the mean levels of antivinculin antibodies in patient and normal sera. Whereas the levels of these antibodies in patient and normal sera overlap, 2 of 82 sera from patients with thrombocytopenia express unusually high levels of such antibodies. The pathologic significance of these antibodies remains to be determined.

Autoantibodies↗
PubMed1991

Recommendations for the evaluation and treatment of neonatal autoimmune and alloimmune thrombocytopenia. The Working Party on Neonatal Immune Thrombocytopenia of the Neonatal Hemostasis Subcommittee of the Scientific and Standardization Committee of the ISTH.

The following recommendations of the Neonatal Hemostasis Subcommittee of the Scientific and Standardization Committee of the ISTH for the management of neonatal immune thrombocytopenia were prepared by the working party on neonatal immune thrombocytopenia. Evaluation, diagnosis, and treatment of the mother and neonate with alloimmune and autoimmune thrombocytopenia are discussed and current recommendations provided. This document is likely to require frequent future revision(s).

Autoimmune Diseases↗
PubMed1991

Localization of human platelet autoantigens to the cysteine-rich region of glycoprotein IIIa.

The object of this study was to further localize autoantigenic structures on IIb-IIIa and, if possible, to precisely identify the epitopes recognized by human autoantibodies. In this paper, we identify a 50-kD chymotryptic fragment of IIIa that is recognized by a high percentage of human autoantibodies, typified by the prototype IgG autoantibody RA, which binds to IIIa on intact platelets as well as in an immunoblot assay under nonreduced conditions. Using an immunoblot assay, a carboxy-terminal region of this fragment (33 kD) that contains the cysteine-rich domains of IIIa was found to carry the epitope(s) recognized by the prototype autoantibody RA. The amino-terminal amino acid sequence of the reduced 33-kD fragment, the smallest fragment that retains the RA epitope, is XPSQQDEXSP, and that of the reduced 50-kD fragment is IVQVTFD. This indicates that the 33-kD fragment consists of approximately 175 amino acids beginning at residue 479 and extending at least through residues 636-654, while the 50-kD fragment spans the same region but begins at residue 427. It is apparent that the 33-kD fragment is generated from the 50-kD fragment by additional chymotryptic hydrolysis but remains associated because of the multiple disulfide bonds that are characteristic of this cysteine-rich domain. Sera from 48% of patients with chronic ITP and 2 of 8 patients with acute ITP contain antibodies that bind to the 50-kD fragment in an ELISA. Antibodies of the same specificity are also found in one-third of patients with either secondary immune thrombocytopenia or apparent non-immune thrombocytopenia. We conclude that the 50-kD cysteine-rich region of IIIa is a frequent target of autoantibodies in ITP, but that such antibodies may also be present in cases of thrombocytopenia that cannot be linked to an apparent autoimmune process.

Autoantibodies↗
PubMed1988

Comparison of a totally implantable access device for chemotherapy (Port-A-Cath) and long-term percutaneous catheterization (Broviac).

Because of the difficulty in maintaining vascular access in patients receiving aggressive parenteral chemotherapy, a growing number of patients have had implantation of either percutaneous or subcutaneous devices allowing permanent intravenous access. In our study, between July 1980 and July 1985, 110 patients had placement of a Broviac catheter, while 100 patients had placement of a subcutaneous device via a subclavian venous approach. Both groups of patients were identical regarding age, primary malignancy, chemotherapy, and nutritional status. Catheter-related sepsis occurred in 15% and thrombotic occlusion in 22% of those patients with Broviac catheters, compared with 3% and 1%, respectively, in patients having subcutaneous reservoirs. Although the initial cost of the subcutaneous reservoir is greater, overall cost of maintenance of the percutaneous catheter far exceeds that of the reservoir because of the need for daily catheter care and heparin flushing of the Broviac device, which is unnecessary for the subcutaneous port. Our experience favors the use of the subcutaneous reservoir in patients receiving prolonged chemotherapy.

Antineoplastic Agents↗