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B Hjelle

Publications and source records attributed to B Hjelle.

86 records · Page 5Linked to original sources
PubMed1990

High frequency of human T-cell leukemia-lymphoma virus type II infection in New Mexico blood donors: determination by sequence-specific oligonucleotide hybridization.

The Albuquerque branch of the United Blood Services system was found to have an unusually high blood donor human T-cell leukemia/lymphoma virus (HTLV) seroprevalence (0.72 per 1,000). Many studies investigating HTLV seroprevalence and transmission have assumed that all seropositivity is due to HTLV type I (HTLV-I); recent data dispute this conclusion. We investigated the high prevalence of HTLV seropositivity in New Mexico by determining whether HTLV-I or HTLV-II is predominant in our donors. Using polymerase chain reaction (PCR) amplification of proviral DNA from peripheral blood, followed by sequence-specific hybridization with oligonucleotide probes to distinguish the two viruses, we demonstrate that 9 of 10 Western blot-confirmed HTLV-seropositive blood donors from New Mexico are infected with HTLV-II. Implications of this finding for donors and the safety of the blood supply are discussed.

Base Sequence↗
PubMed1990

Transmission of HTLV-II via blood transfusion.

Transmission of HTLV-I by transfusion is well documented in Japan, where HTLV-I is endemic. In non endemic regions such as the United States, HTLV-I/II infection has been transmitted by transfusion as well, but no effort to distinguish HTLV-I from HTLV-II infection was made in these studies. There is a growing body of evidence that a substantial proportion of HTLV-I/II seropositivity in the US is due to infection with HTLV-II. We report 2 cases of apparent transfusion-transmitted HTLV-II infection and discuss the importance of distinguishing between the two viruses in blood donors and recipients.

Adult↗
PubMed1989

A poorly differentiated lymphoma of donor origin in a renal allograft recipient.

Malignant lymphoma is a frequent complication of organ transplantation. It has been suggested that such tumors arise as a result of uncontrolled proliferation of Epstein-Barr virus-infected B lymphocytes in an immunosuppressed host. Although a few cases of posttransplant lymphomas in bone marrow transplantation have been shown to be of donor cell origin, no recipients of solid-organ transplants are known to have developed lymphomas arising from donor cells. In this report, a case of diffuse high-grade lymphoma that apparently arose in the allograft of a renal transplant recipient is described. DNA fingerprinting demonstrated the tumor to be of donor origin; Epstein-Barr sequences were absent. A therapeutic trial consisting of withdrawal of immunosuppressive agents and administration of acyclovir was unsuccessful. These data support the notion that donor cells can undergo malignant transformation in solid-organ transplant recipients, and such tumors need not carry EBV genetic material.

Adolescent↗
PubMed1989

Direct methods for detection of HIV-1 infection.

The detection of human immunodeficiency virus type 1 (HIV-1) antibodies has proved to be a highly sensitive and specific means for the diagnosis of HIV-1 infection. Serologic methods have limitations in several specific clinical situations, however. In response to these problems, a wide variety of alternative diagnostic tests has been developed that detect infectious virus or structural components of the virus. All of the macromolecular constituents of HIV-1, DNA, RNA, and protein, have served as markers for the presence of the virus. In this article, we review the use of such direct methods and attempt to determine the likely place for each class of direct test in the diagnostic armamentarium.

AIDS Serodiagnosis↗
PubMed1988

Oncogene v-src transforms and establishes embryonic rodent fibroblasts but not diploid human fibroblasts.

The conversion of cells from a normal phenotype to full malignancy apparently requires multiple genetic events. Efforts to reconstruct multistep tumorigenesis in cell culture have shown that two types of oncogenes (typified by HRAS and MYC) can cooperate to elicit complete transformation. Transformation of embryonic rodent cells by single oncogenes is reputed either not to occur or to require specialized circumstances. It has not been known how the large group of oncogenes that encode protein-tyrosine kinases might fit into this scheme. We now report that v-src, a prototype for the kinase oncogenes, can convert rat embryo fibroblasts to a fully transformed and tumorigenic phenotype when the gene is expressed vigorously. By contrast, v-src had no demonstrable effect on diploid human fibroblasts. Our results sustain the view that it is possible for at least some oncogenes to achieve a potency sufficient for unilateral tumorigenesis.

Animals↗
PubMed1988

Transforming genes in chronic myelogenous leukemia.

Chronic myelogenous leukemia (CML) is a hematopoietic malignancy characterized by an indolent chronic phase that invariably leads to a "blast crisis" indistinguishable from acute leukemia. Using a sensitive assay based on gene transfer and tumorigenesis, we sought evidence that damage to protooncogenes might figure in the progression from the chronic to the blast phase of CML. Seven of the 12 patients with CML examined in this manner harbored transforming genes. Mutations in RAS protooncogenes were detected in the leukemic cells from 1 of 6 chronic-phase patients, and 3 of 6 blast-crisis patients. In addition, a presently unidentified transforming gene (neither RAS nor RAF) was detected in 1 patient with chronic phase and 1 with blast crisis. Our data indicate that mutations in RAS genes may play diverse roles in the pathogenesis of CML.

Animals↗
PubMed1982

Hemoglobin H disease and multiple congenital anomalies in a child of northern European origin.

Hemoglobin H (HbH) disease was recently described in three unrelated northern European boys with mental retardation. We have studied a somewhat similar patient, in whom HbH disease was associated with multiple congenital anomalies. Restriction endonuclease analysis of DNA from this proband yielded a pattern consistent with the alpha-/-- genotype commonly associated with the HbH phenotype in Asians. His parents both carry alpha thalassemia, in contrast to the previously described families in which only one of the two parents was a carrier.

Abnormalities, Multiple↗
PubMedDate not supplied

Mutations of the Kirsten-ras proto-oncogene in human preleukaemia.

The myelodysplastic syndrome (MDS) or preleukaemia is a haematological disorder characterized by low blood counts, bone marrow cells of abnormal appearance and progression to acute leukaemia in as many as 30% of patients. The distinctive preleukaemic and leukaemic phases of this disease make it an attractive model for neoplastic progression in human tumours. We reasoned that, because dominantly transforming genes (such as mutant alleles of ras proto-oncogenes) are found so frequently in acute leukaemia, the search for these genetic lesions during the clinical course of patients with MDS might give us insight into the function of oncogenes in leukaemogenesis. We report here that bone marrow cells from two of four patients with preleukaemia, and from one patient who progressed to acute leukaemia from MDS, contained a transforming allele of the Ki-ras proto-oncogene. In one preleukaemic patient, a novel mutation in codon 13 of this ras gene was detected in bone marrow cells harvested 1.5 years before the acute leukaemia developed. Our findings provide evidence that ras mutations may be involved in the early stages of human leukaemia.

Adult↗
PubMedDate not supplied

Antibody to c antigen consequent to renal transplantation.

A case of apparent red cell (RBC) autoimmunity due to anti-c is described in the recipient of a cadaveric renal transplant. Although the patient suffered little hemolysis as a result, a strong direct anti-c agglutinin was detectable on the patient's RBCs 8 days after transplantation and in his serum only 4 days after transplantation. We believe that the antibody was produced by passively transferred B lymphocytes in the donor kidney, and that the recipient may have been protected from more serious hemolysis by immunosuppressive agents administered at the time of transplantation. The donor received multiple transfusions before transplantation, but his serum lacked anti-c in a screen performed shortly before his death. This case raises the possibility that donor alloantibodies to other Rh antigens on recipient RBCs can arise after transplantation, if the donor has been transfused.

Adolescent↗
PubMedDate not supplied

Serologic survey for hantavirus infections among wild animals in rural areas of São Paulo State, Brazil.

A serosurvey was conducted in wild animals captured close to two areas where hantavirus cardiopulmonary syndrome (HCPS) occurred in São Paulo State, Brazil. Serum samples from a total of 43 mammals were tested for antibodies reactive with Sin Nombre (SN) hantavirus using a strip immunoblot assay. RNAs from the blood clots of the positive samples were submitted to reverse transcriptase-polymerase chain reaction (RT-PCR). Two rodents of the genus Oligoryzomys were positive for hantavirus antibodies. These animals were captured in the Iguape region and represented 16.7% (2/12) of the sera from rodents and 100.0% (2/2) of the Oligoryzomys captured in that area. RT-PCR failed to amplify any viral cDNA. These results are in agreement with other data that suggest that members of this genus are important reservoirs of hantaviruses in Brazil.

Animals↗
PubMedDate not supplied

Hantaviruses: a global disease problem.

Hantaviruses are carried by numerous rodent species throughout the world. In 1993, a previously unknown group of hantaviruses emerged in the United States as the cause of an acute respiratory disease now termed hantavirus pulmonary syndrome (HPS). Before than, hantaviruses were known as the etiologic agents of hemorrhagic fever with renal syndrome, a disease that occurs almost entirely in the Eastern Hemisphere. Since the discovery of the HPS-causing hantaviruses, intense investigation of the ecology and epidemiology of hantaviruses has led to the discovery of many other novel hantaviruses. Their ubiquity and potential for causing severe human illness make these viruses an important public health concern; we reviewed the distribution, ecology, disease potential, and genetic spectrum.

Animals↗
PubMedDate not supplied

Seroepidemiologic studies of hantavirus infection among wild rodents in California.

A total of 4,626 mammals were serologically tested for antibodies to Sin Nombre virus. All nonrodent species were antibody negative. Among wild rodents, antibody prevalence was 8.5% in murids, 1.4% in heteromyids, and < 0.1% in sciurids. Of 1,921 Peromyscus maniculatus (deer mice), 226 (11.8%) were antibody positive, including one collected in 1975. The highest antibody prevalence (71.4% of 35) was found among P. maniculatus on Santa Cruz Island, off the southern California coast. Prevalence of antibodies among deer mice trapped near sites of human cases (26.8% of 164) was significantly higher than that of mice from other sites (odds ratio = 4.5; 95% confidence interval = 1.7, 11.6). Antibody prevalence increased with rising elevation (> 1,200 meters) and correlated with a spatial cluster of hantavirus pulmonary syndrome cases in the Sierra Nevada.

Animals↗
PubMedDate not supplied

Bayou virus-associated hantavirus pulmonary syndrome in Eastern Texas: identification of the rice rat, Oryzomys palustris, as reservoir host.

We describe the third known case of hantavirus pulmonary syndrome (HPS) due to Bayou virus, from Jefferson County, Texas. By using molecular epidemiologic methods, we show that rice rats (Oryzomys palustris) are frequently infected with Bayou virus and that viral RNA sequences from HPS patients are similar to those from nearby rice rats. Bayou virus is associated with O. palustris; this rodent appears to be its predominant reservoir host.

Animals↗