Steven Lobel - Academia.edu (original) (raw)

Papers by Steven Lobel

American Journal of Hematology, 1988

To examine the variables associated with heterosexual transmission of human immuno‐deficiency vir... more To examine the variables associated with heterosexual transmission of human immuno‐deficiency virus (HIV), we studied 32 couples in our hemophilia center who had steady sexual relationships for periods more than 1 year. Of the 32 sexual partners of the hemophiliacs, five (15.6%) were HIV seropositive. All five hemophiliacs with HIV transmission to their sexual partners had measurable immunologic deficiencies, as shown by their lower median T‐helper (CD‐4 +) lymphocyte count of 172 cells/mm3. The hemophiliacs without transmission had a slightly higher median CD‐4 + count of 297 cells/mm3 (P = 26). To determine if factors other than the degree of immunologic deficiency in the hemophiliac might contribute to HIV transmission, 18 of the 32 couples were studied more intensively by confidential, coded questionnaires. Regular condom use was reported by nine couples (50%). Two of nine women (22%) without condom usage acquired HIV. One of nine women (11%) using condoms was seropositive; she also reported eight needlestick injuries while assisting her spouse with clotting factor treatments. Intravenous drug abuse was reported in two of the five couples with HIV transmission. Thus, hemophiliacs are at risk for transmitting HIV parenterally as well as venereally. Despite various risk behaviors associated with HIV transmission, the prevalence of infection in our cohort of hemophiliacs' sexual partners is low and within the range (6.8–22%) reported by others. This study underscores the need for comprehensive education and counseling in what previously appeared to be a homogeneous clinic population at risk for transmitting HIV to others.

The International Journal of Artificial Organs, 1992

In this study we measured indices of T-lymphocyte activation in normal volunteers, chronic hemodi... more In this study we measured indices of T-lymphocyte activation in normal volunteers, chronic hemodialysis patients, CAPD patients and chronic renal failure patients not yet on dialysis. Serum IL-2 levels were elevated in patients compared to controls. Soluble IL-2 receptors were elevated in all three patient groups and were highest in CAPD patients. Clearance of IL-2 and soluble interleukin receptors was negligible in dialysis and renal failure patients. Hemodialysis patients had a significantly lower percentage of CD3-positive cells than all other groups. Hemodialysis with a variety of membrane/bath combinations did not significantly affect any of the parameters measured. This study provides some support for the hypothesis that chronic T-cell activation is present in renal failure.

Annals of allergy, 1988

During her 26th week of pregnancy a 20-year-old woman developed generalized pruritus, urticaria, ... more During her 26th week of pregnancy a 20-year-old woman developed generalized pruritus, urticaria, flushing, tinnitus, and tachycardia during plasmapheresis with 5% human serum albumin (HSA) as adjunctive treatment for anti-Kell isoimmunization. The reaction was controlled with intravenous diphenhydramine. Despite pretreatment with diphenhydramine and betamethasone a subsequent attempt to perform plasmapheresis with infusion of 5% HSA resulted in a more severe reaction which progressed to respiratory distress. Intradermal skin testing with 5% HSA produced a 9 x 11-mm wheal and 17 x 21-mm erythema at 15 minutes. An enzyme-linked immunoassay was positive for IgE antibody to 5% HSA before and after dialysis for removal of Na caprylate. These results are consistent with an IgE-mediated basis for this patient's reaction to HSA.

Laboratory Medicine, 1989

The Indian Journal of Pediatrics, 1984

Immunology, 1984

We have produced a mouse anti-rabbit Ia monoclonal antibody (MAb) that detects an isotypic determ... more We have produced a mouse anti-rabbit Ia monoclonal antibody (MAb) that detects an isotypic determinant on all rabbit Ia molecules. This MAb precipitates three polypeptide chains with molecular weights of 28,000, 31,000 and 35,000, corresponding to the Ia beta, Ii and alpha chains, respectively. The anti-Ia MAb inhibits the mixed lymphocyte culture by 80%. In secondary in vitro immune response cultures, the anti-Ia MAb inhibits the proliferative response to bovine insulin and poly (Glu50Tyr50). In studies on mitogenesis it was found that the anti-Ia MAb inhibited the response to LPS but not to concanavalin A or phytohaemagglutinin. The effect of the anti-Ia MAb on other mitogens was found to vary from rabbit to rabbit.

Annals of allergy, 1989

An 8-year-old male with AIDS and disseminated Mycobacterium avium intracellulare infection was tr... more An 8-year-old male with AIDS and disseminated Mycobacterium avium intracellulare infection was treated with transfer factor (TF) prepared from maternal lymphocytes. Subsequent lymphocyte stimulation studies and repeat cultures failed to demonstrate improvement during treatment. His overall clinical status remained unchanged. No adverse effects of TF were noted.

Transplantation, 1979

Immunization of mice with allogeneic brain homogenates fails to elicit an appreciable response to... more Immunization of mice with allogeneic brain homogenates fails to elicit an appreciable response to the Thy-1 antigen. The aim of the present study was to determine the mechanism of the low immunogenicity of allogeneic brain. Immunization of C3H mice with freshly prepared mixtures of AKR/J thymus cells with either AKR/J or C3H brain homogenates elicited a primary response to the Thy-1.1 antigen as effectively as immunization with AKR/J thymus cells. When the mixtures were incubated overnight prior to injection, only AKR/J brain homogenate but not C3H brain homogenate abrogated the capacity of AKR/J thymus cells to elicit an anti-Thy-1.1 response. Suppressor T cells did not seem to be responsible for the inability of brain to elicit an anti-Thy-1 response, as mice that received cyclophosphamide 2 days prior to injection of brain did not produce Thy-1 antibodies. Antigenic competition also did not seem to be the cause for the weak immunogenicity of Thy-1 on brain, as mixtures of thymus and brain were capable of eliciting a primary response. When spleen cells from mice hyperimmunized against Thy-1 were transferred to normal syngeneic mice, subsequent immunization with brain homogenate was capable of eliciting Thy-1 antibodies. These results indicate that Thy-1 on brain may resemble a hapten, in being incapable of eliciting a primary immune response, but behaves like a complete antigen in boosting a secondary response.

Journal of Pediatric Hematology/Oncology, 1986

In some infants with Down's syndrome, the circulating mononuclear population, when viewed... more In some infants with Down's syndrome, the circulating mononuclear population, when viewed with conventional and electron microscopy, contains many cells that closely resemble leukemic blast cells. In contrast with true leukemia, however, most of these infants with the "leukemia-like reaction in Down's syndrome" (LLR-DS) enter spontaneous remissions. We therefore investigated the natural resistance of such infants to hematological malignancy in vitro by means of natural killer cell assays. Mean natural killer cell determinations in four infants with LLR-DS were 17.5 +/- 9.2% and 37.6 +/- 18.5% against K-562 and Molt-4 target cells, respectively, at diagnosis. Later, during remission, these values were 34.3 +/- 14.3% against K-562 and 32.2 +/- 15.6% against Molt-4. The mean percentage lysis of Molt-4 both at diagnosis and during remission was greater (p less than 0.05) in LLR-DS than in children with acute lymphocytic leukemia and acute myelogenous leukemia at diagnosis. Natural killer cell activity levels in these LLR-DS patients were similar to levels obtained in other infants with Down's syndrome who were hematologically normal, as well as levels obtained in normal control specimens. Two of these LLR-DS patients progressively developed acute myelogenous leukemia with ultrastructural abnormalities several months later; one of these also developed another karyotype abnormality. Both remain in long-term remission exceeding 48 months.

Journal of Allergy and Clinical Immunology, 1989

A male adolescent with common variable immunodeficiency developed type I diabetes approximately 1... more A male adolescent with common variable immunodeficiency developed type I diabetes approximately 1 year after the initiation of immunoglobulin therapy. Immunologic evaluation revealed decreased numbers of T cells and an intrinsic B cell defect in immunoglobulin production. Lymphocytes from the patient failed to generate normal suppressor activity. There were no insulin or islet cell antibodies present in the patient's serum or in the commercial immunoglobulin preparations he received. The patient's HLA phenotype included HLA-DR3 and 4, placing him genetically at high risk for type I diabetes.

Immunogenetics, 1981

A new recombination within the major histocompatibility complex (R T1) of the rat has been detect... more A new recombination within the major histocompatibility complex (R T1) of the rat has been detected. The recombination occurred between a wildderived haplotype, provisionally designated pl, and the RTI haplotype of the BN strain. The recombinant haplotype, designated p3, carries the RTI.A locus (classical histocompatibility antigens) of the BN strain, a locus from the BN strain that codes for the expression of an Ia antigen and strong mixed lymphocyte response (MLR), and a second locus derived from the pl haplotype that controls the expression of a second Ia antigen, the ability to elicit a strong MLR and the immune response to poly(Glu52Lys33Tyr15). This recombinant therefore demonstrates the division of the R T1.B region into two loci, tentatively designated R T1 .B and R T1.D, and provides evidence for the existence of at least four loci in the MHC of the rat.

Clinical and Vaccine Immunology, 2010