Seroprevalence of Borrelia burgdorferi in North Eastern India

Background: There is paucity of data on Lyme disease in India. A seroprevalence study of B burgdorferi infection was carried out in North-Eastern states of India to assess the same.     

Immunohistochemical evaluation of TGF-β and extracellular matrix proteins expression in rat squamous cell carcinomas

OBJECTIVE: The aim of this study was to establish a possible association between the degree of differentiation of squamous cell carcinomas (SCC) derived from rat oral tissues treated in vivo with the carcinogen 4NQO, and the expression of TGF-β on epithelial cells and the distribution of extracellular matrix proteins (laminin-collagen type IV).
MATERIALS AND METHODS: A parent tumour showing a spectrum of differentiation was used to establish clonal subpopulations that formed differentiated SCC and undifferentiated (spindle cell phenotype) tumours following transplantation to athymic mice.
RESULTS tmmunohistological findings revealed the absence of TGF-β staining on epithelial cells and extracellular matrix proteins in spindle cell tumours. In contrast, staining of SCC revealed a significant number of TGF-β positive cells and the presence of extracellular matrix proteins.
CONCLUSIONS: The findings suggested that there is a positive correlation between histological differentiation, TGF-β expression and the elaboration of extracellular matrix proteins.     

Antineutrophil cytoplasmic antibodies in T-cell receptor alpha-deficient mice with chronic colitis

BACKGROUND & AIMS: Antineutrophil cytoplasmic antibodies (ANCAs) have been detected in approximately 60% of sera from patients with ulcerative colitis. The aim of this study was to examine the presence of ANCAs and distribution of ANCA-producing B cells in the lymphoid tissue of T-cell receptor alpha-deficient (TCR-alpha-/-) mice that develop chronic colitis resembling human ulcerative colitis. METHODS: Sera from 87 TCR-alpha-/- mice were tested for the presence of ANCAs by enzyme-linked immunosorbent assay against a human neutrophil extract and selected antigens and by immunofluorescence study using human neutrophils. Enzyme-linked immunospot assay was used for detecting ANCA-producing cells from spleen, mesenteric lymph node (MLN), or colon. RESULTS: Approximately 70% of sera from TCR-alpha-/- mice showed reactivity against human neutrophil extracts by enzyme-linked immunosorbent assay. Sixty percent of ANCA-positive sera showed a perinuclear reaction pattern. By enzyme-linked immunospot, ANCA-producing cells were detected in MLN and colon and less often in the spleen of TCR-alpha-/- mice with chronic colitis. The predominant immunoglobulin isotype of these autoantibodies was immunoglobulin A in the colon but not in the MLN and spleen. CONCLUSIONS: TCR-alpha-/- mice produce ANCAs. The ANCA (immunoglobulin A isotype)-producing B cells exist primarily in the diseased colonic mucosa of TCR-alpha-/- mice. (Gastroenterology 1997 Dec;113(6):1828-35)     

Prenatal diagnosis of beta-thalassemias by amniocentesis: linkage analysis using multiple polymorphic restriction endonuclease sites

In order to assess the applicability of multiple restriction endonuclease analyses of amniocyte DNA to the prenatal diagnosis of beta-thalassemias in general, we studied 12 consecutive couples at risk. DNA of both members of the 12 couples and a previous offspring of each was analyzed for the presence of 4 polymorphic restriction endonuclease sites: the Hpa I site 3' to the beta-globin gene, the Hind III site in the G gamma gene, the Hind III site in the A gamma gene, and the Bam HI site 3' to the beta-gene. Linkage disequilibrium between these sites and beta A or beta thal genes was not found, presumably due to the heterogeneity of beta thal genes. However, the high frequency of polymorphism at these sites allowed differentiation of beta A-bearing chromosomes from beta thal or beta S-bearing chromosomes in both members of 6 couples. In these couples, complete prenatal diagnosis by linkage analysis of amniocyte DNA would be possible. In the remaining 6 couples, beta A and beta thal chromosomes could be discriminated in one member. In about 50% of the pregnancies of these couples, exclusion of beta-thalassemia is possible by this analysis. These data suggest that when linkage analysis of polymorphic restriction endonuclease sites is carried out, prenatal diagnosis of beta-thalassemia states can be accomplished by amniocentesis alone in 75% of pregnancies at risk.     

The place of high-dose BEAM therapy and autologous bone marrow transplantation in poor-risk Hodgkin's disease. A single-center eight- year study of 155 patients

Although high-dose chemotherapy and autologous bone marrow transplantation (ABMT) are increasingly being used for the treatment of relapsed and resistant Hodgkin's disease, there have been few large, single-center studies reported with adequate follow-up to allow full evaluation of this therapeutic modality. We present 155 poor-risk Hodgkin's disease patients who received high-dose BEAM (BCNU, etoposide, cytosine arabinoside, and melphalan) chemotherapy and ABMT who have been studied over a period of 8 years. All patients had either not attained a remission on mechlorethamine, vincristine, procarbazine, prednisone-type therapy and had poor prognostic features at presentation, not attained a complete remission or relapsed within 1 year of an initial alternating regimen, or not attained remission with two or more lines of treatment. At the time of ABMT the relapse status of the patients was as follows: 46 patients were primarily refractory to induction therapy, 7 were good partial responders, 52 were in first relapse, 37 in second relapse, and 13 in third relapse. Seventy-eight patients had chemoresistant disease, 33 had chemosensitive disease at the time of ABMT, and 44 were untested for chemosensitivity at latest relapse. The procedure related mortality in the first 90 days post-ABMT of 10% overall. At 3 months 43 patients (28%) were assessed as complete responders, 72 patients had a partial response (46%), and 24 patients (16%) had no response or progression of disease. However, by 6 months, 53 (24%) patients were assessed as complete responders and 51 (33%) patients had nonprogressive disease. Forty-five patients had received radiotherapy post-ABMT to residual masses (41 patients) or to previous sites of bulk disease (4 patients). The actuarial overall and progression-free survival at 5 years was 55% and 50%, respectively. On multivariate analysis patients with bulk (masses > 10 cm), heavily pretreated patients (those receiving three or more lines of treatment) and females had a significantly poorer prognosis. Relapse status was also significant for progression-free survival in that patients in second (60%) and third relapse (70%) had a better prognosis than those in first relapse (44%) or with primary refractory disease (33%). Response to prior chemotherapy did not predict for progression-free survival. These results enable comparisons to be made between high-dose chemotherapy with ABMT and conventional dose salvage therapy. Furthermore, although the results as a whole are highly encouraging, certain groups carry an unfavorable prognosis.     

Impaired cytoplasmic ionized calcium mobilization in inherited platelet secretion defects

Defects in platelet cytoplasmic Ca++ mobilization have been postulated but not well demonstrated in patients with inherited platelet secretion defects. We describe studies in a 42-year-old white woman, referred for evaluation of easy bruising, and her 23-year-old son. In both subjects, aggregation and 14C-serotonin secretion responses in platelet-rich plasma (PRP) to adenosine diphosphate (ADP), epinephrine, platelet activating factor (PAF), arachidonic acid (AA), U46619, and ionophore A23187 were markedly impaired. Platelet ADP and adenosine triphosphate (ATP), contents and thromboxane synthesis induced by thrombin and AA were normal. In quin2-loaded platelets, the basal intracellular Ca++ concentration, [Ca++]i, was normal; however, peak [Ca++]i measured in the presence of 1 mmol/L external Ca++ was consistently diminished following activation with ADP (25 mumol/L), PAF (20 mumol/L), collagen (5 micrograms/mL), U46619 (1 mumol/L), and thrombin (0.05 to 0.5 U/mL). In aequorin-loaded platelets, the peak [Ca++]i studied following thrombin (0.05 and 0.5 U/mL) stimulation was diminished. Myosin light chain phosphorylation following thrombin (0.05 to 0.5 U/mL) stimulation was comparable with that in the normal controls, while with ADP (25 mumol/L) it was more strikingly impaired in the propositus. We provide direct evidence that at least in some patients with inherited platelet secretion defects, agonist-induced Ca++ mobilization is impaired. This may be related to defects in phospholipase C activation. These patients provide a unique opportunity to obtain new insights into Ca++ mobilization in platelets.     

In situ immunologic characterization of cellular constituents in lymph nodes and spleens involved by Hodgkin's disease

The cellular constituents in lymph nodes and spleens of patients with Hodgkin's disease were studied with a series of monoclonal antibodies directed against human thymocyte, peripheral T-cell, and la antigens. Utilizing both an immunoperoxidase technique on frozen tissue sections and indirect immunofluorescence on cell suspensions, wer found that a majority of lymphocytes were T cells, since they stained with anti-T1 and anti-T3 antibodies, which react with all peripheral T cells. In addition, most of these cells were reactive with anti-T4 antibody, which defines the helper/inducer T-cell population, whereas only a minority of cells stained with anti-T5 and anti-T8 antibodies, which are reactive with suppressor/cytotoxic T cells. Moreover, a large proportion of T cells expressed T10 antigen, which is found on activated T cells. A minority of the T cells also expressed la antigen(s), again suggesting that some of the T cells are activated. In contrast, the Reed-sternberg cells did not react with any of these anti- T-cell antibodies or with anti-IgM antiserum, but displayed strong membrane and cytoplasmic staining with anti-la antibody. Taken together, these findings suggest that Reed-Sternberg cells are not of T- cell lineage but may be derived from antigen-presenting reticulum cells in the thymus-dependent areas of lymphoid tissues; these cells are normally associated with T4+ cells.     

Idiotype-reactive T-cell subsets and tumor load in monoclonal gammopathies

The presence of idiotype-reactive T-cell subsets and their relation to the tumor load were analyzed in 9 patients with monoclonal gammopathy of undetermined significance (MGUS), in 12 patients with multiple myeloma (MM) clinical stage I, and in 9 patients with MM stage II/III. An enzyme-linked immunospot assay was used to identify interferon-gamma (IFN-gamma)-, interleukin-2 (IL-2)-, or IL-4-secreting T cells after stimulation by F(ab')2 fragments of monoclonal IgG. The response to autologous IgG was significantly higher than that induced by isotypic monoclonal IgG. Comparable results were obtained in a proliferation assay (3H-thymidine incorporation). A total of 8 of 9 patients with MGUS, 7 of 12 patients with MM stage I, and 3 of 9 with MM stage II/III had T cells secreting IFN-gamma and/or IL-2 (T helper [Th1] type-1 cells), whereas cells secreting both Th1 and Th2 or Th0 types of cytokines were more frequent in patients with MM, particularly in those with MM stage II/III. The number and frequency of Th1-type cells were significantly higher in MGUS patients as compared with those of MM stage II/III. The results indicate that idiotype-reactive T cells of the Th1 and Th2 or Th0 subsets were present in MGs and might provide indirect evidence that idiotype-reactive Th1-type cells may have a regulatory impact on the human tumor B cells.