Mammalian transforming growth factor beta1 activated after ingestion by Anopheles stephensi modulates mosquito immunity

During the process of bloodfeeding by Anopheles stephensi, mammalian latent transforming growth factor beta1 (TGF-beta1) is ingested and activated rapidly in the mosquito midgut. Activation may involve heme and nitric oxide (NO), agents released in the midgut during blood digestion and catalysis of L-arginine oxidation by A. stephensi NO synthase (AsNOS). Active TGF-beta1 persists in the mosquito midgut to extended times postingestion and is recognized by mosquito cells as a cytokine. In a manner analogous to the regulation of vertebrate inducible NO synthase and malaria parasite (Plasmodium) infection in mammals by TGF-beta1, TGF-beta1 regulates AsNOS expression and Plasmodium development in A. stephensi. Together, these observations indicate that, through conserved immunological cross talk, mammalian and mosquito immune systems interface with each other to influence the cycle of Plasmodium development.     

Low density lipoprotein receptor activity in human leukemic cells--relation to chromosome aberrations

Chromosome analysis and low density lipoprotein (LDL) receptor activity of leukemic cells from 38 patients with acute non-lymphocytic leukemia were correlated. Clonal chromosome aberrations were found in 22 patients, and an extra chromosome 8 was found in 7 of them. LDL receptor activity was significantly higher in patients with an extra chromosome 8 than in patients with other abnormalities or a normal karyotype. Chromosome 8 may harbor genes of importance for the expression of the LDL receptor.     

Alternate Pathway Activation in Sickle Cell Disease and ��-Thalassemia Major

Total hemolytic complement activity (CH50), immuno-electrophoretic conversion of Factor B (C3PA), and of C3 were studied in 16 patients with sickle cell disease in a steady state, eight patients in crisis, and ten patients with β-thalassemia major anemia maintained on a constant transfusion regimen. Patients with sickle cell disease in a steady state have moderatley 56 (percent) depressed conversion of Factor B in addition to markedly decreased conversion of C3 in four of ten patients. One of the three sickle cell patients and two of the four thalassemia patients with low C3 conversion levels have died subsequent to the studies. The combination of chronically decreased Factor B conversion in the face of markedly decreased C3 conversion may make these patients occasionally vulnerable to overwhelming infection analagous to the situation seen in postsplenectomy cases.     

Familial testicular cancer: interest in genetic testing among high-risk family members.

PURPOSE: This study is part of an ongoing National Cancer Institute multidisciplinary, etiologically-focused, cross-sectional study of Familial Testicular Cancer (FTC). The current report targets interest in clinical genetic testing for susceptibility to FTC. METHODS: Demographics, knowledge, health beliefs, and psychological and social factors were evaluated as covariates related to interest in genetic testing. RESULTS: The majority (66%) of 229 participants (64 affected men, 66 unaffected men, and 99 women) from 47 multiple-case FTC families expressed interest in having a genetic test within 6 months, should such a test become available. Interest was similar among the three subgroups mentioned above. Worries about insurance discrimination based on genetic test results were associated with a significantly lower interest in testing. Alternatively, participants were more likely to be interested in genetic testing if they were younger and had higher levels of family support, a physician's recommendation supporting testing, cancer distress, and a need for information to inform the health care of their children. CONCLUSIONS: This study reveals social and relationship factors that FTC survivors and their relatives considered important when contemplating the use of new genetic technologies. This is the first study describing hypothetical interest in genetic testing for familial testicular cancer.     

Indirect evidence of bronchial inflammation assessed by titration of inflammatory mediators in BAL fluid of patients with asthma

Bronchial inflammation is a characteristic of asthma that may be examined indirectly by bronchoalveolar lavage (BAL). Nine normal individuals were compared with 38 age-matched adults with asthma of variable severity to appreciate the importance of cell activation in the severity of asthma. The severity of asthma was appreciated by the clinical score of Aas and the pulmonary function of the patients. FEV1 ranged between 35% and 130% of predicted. The indirect activation of eosinophils (EOSs), mast cells, fibroblasts, and neutrophils was examined by the titration of eosinophil cationic protein (ECP), tryptase, hyaluronan (HA), and myeloperoxidase (MPO) by radioimmunoassay in BAL fluid (BALF) and cytology of BALF. In the adults with asthma, there was a significantly increased number of EOSs and a significantly increased level of all mediators but MPO. MPO levels were increased in seven patients only; three of these patients were previous smokers. Only ECP and HA levels were significantly correlated with the severity of asthma. These results demonstrate EOSs, mast cells, and fibroblasts are activated in asthma, whereas the involvement of neutrophils is less clear. There was a significant correlation between ECP and HA levels, suggesting a common activation of EOSs and fibroblasts.     

The slide centrifuge gram stain as a urine screening method.

A slide centrifuge Gram stain procedure was performed to screen for bacteriuria 4161 urine specimens submitted in urine preservative tubes for routine culture. For slide centrifuge Gram staining, each urine sample was mixed well. Thereafter, 0.2 mL of each sample was placed, using a pipette, into a slide centrifuge chamber and centrifuged at 2,000 rpm for 5 minutes. The slides were heat fixed, Gram stained, and read by laboratory personnel who scanned 12 consecutive oil-immersion fields using a set pattern. The presence of the same organism in six or more fields was defined as a positive urine screen. Urine samples were cultured using a 0.001-mL loop and a comparison of culture growth with slide centrifuge screening was made. When growth of 100,000 or more colony-forming units per milliliter (CFU/mL) was the reference for comparison, the screen had a sensitivity rate of 98%, a specificity rate of 90%, a negative predictive value of 99%, and a positive predictive value of 65%. When a lower colony count of 10,000 or more CFU/mL was the reference for comparison, the screen had a sensitivity rate of 88%, a specificity rate of 95%, a negative predictive value of 96%, and a positive predictive value of 84%. The slide centrifuge Gram stain is a very sensitive screening method to detect bacteriuria in an adult male population.     

Purkinje cell protein-2 regulatory regions and transgene expression in cerebellar compartments

The Purkinje cell protein 2 (Pcp-2) is expressed in cerebellar Purkinje cells and retinal bipolar neurons. To illuminate how Pcp-2 expression is restricted to only two neuronal types and to derive tools to express heterologous genes in these neuronal subpopulations, genomic sequences of the mouse Pcp-2 gene have been cloned and flanking sequences have been evaluated as a source of neuron-specific regulatory elements. An upstream region with homology to other genes expressed in neurons was identified and a hybrid gene containing this sequence was constructed by ligating 0.4 kb of upstream and 0.3 kb of downstream Pcp-2-flanking DNA to lacZ. Transgenic mice bearing this construct exhibited beta-galactosidase in a wide array of neuron types, suggesting that this sequence may play an important role in specifying neuronal expression. Addition of a further 3.1 kb of Pcp-2 upstream sequences restricted expression of beta-galactosidase to a small number of neuron types and most notably to Purkinje cells within parasagitally oriented cerebellar compartments. The presence of elements lying within the 3.1-kb upstream region and acting to specifically restrict Pcp-2 expression is therefore suggested. Moreover, as beta-galactosidase was not expressed in the bipolar cells of these transgenic mice, retinal expression of the endogenous Pcp-2 gene must involve elements in addition to those conferring expression within Purkinje cells.     

Characterization of a monoclonal antibody and its single-chain antibody fragment recognizing the nucleoside Triphosphatase/Helicase domain of the hepatitis C virus nonstructural 3 protein

We have produced a murine monoclonal antibody (MAb), ZX10, recognizing the NTPase/helicase domain of the hepatitis C virus (HCV) nonstructural 3 protein (NS3), from which we designed a single-chain variable fragment (ScFv). The ZX10 MAb recognized a discontinuous epitope of the NTPase/helicase domain, of which the linear sequence GEIPFYGKAIPL at residues 1371 to 1382 constitutes one part. cDNAs from variable regions coding for the heavy and light chains were cloned, sequenced, and assembled into the NS3-ScFv, which was inserted into procaryotic and eucaryotic expression vectors. Escherichia coli-expressed NS3-ScFv inhibited the binding of the ZX10 MAb to NS3, confirming a retained specificity. However, the ability to bind the peptide 1371-1382 had been lost. In vitro-translated NS3-ScFv and HCV NS3/NS4A were coprecipitated by antibodies to HCV NS4A, confirming the in vitro activity of the NS3 ScFv. Thus, we have designed a functional NS3 NTPase/helicase domain-specific ScFv which should be evaluated further with respect to disturbing enzymatic functions of the NS3 protein.     

Detection of rubella antibodies by hemagglutination inhibition, indirect fluorescent-antibody test, and enzyme-linked immunosorbent assay.

Using hemagglutination inhibition (HAI) as a reference method, 292 (40 nonimmune, 252 immune) human serum samples were tested by indirect fluorescent antibody (IFA) and enzyme-linked immunosorbent assay (ELISA) for immune status and quantitation of rubella antibodies. The overall agreement with HAI for immune status was 99.7% (291/292) with IFA and 98.6% (288/292) with ELISA. Two specimens (0.7%, 2/292), negative by HAI, were equivocal by ELISA. Initially a 6.5% (19/292) overall disagreement was obtained for immune status evaluation between HAI and IFA, which was reduced to 0.3% (1/292) upon repeat testing. All of these samples were near the immune/nonimmune cutoff point (95 samples), reflecting an initial disagreement of 20% (19/95) in this category (HAI titers less than 1:20). Likewise, an initial overall disagreement of 4.5% (13/292) was obtained between HAI and ELISA which was reduced to 0.7% (2/292) upon repeated testing. Eleven of the 13 samples were near the immune/nonimmune cutoff point, reflecting an initial disagreement of 11.6% (11/95) with sera having an HAI antibody titer of less than 1:20. Quantitation of rubella antibodies by IFA showed an overall correlation with HAI of 86.6% within less than twofold titer and 99.3% within less than fourfold titers. In testing the ability of ELISA to quantitate antibody, a correlation coefficient (r) of 0.996 was obtained by plotting the measured average optical density (405 nm) of ELISA against the corresponding log of HAI titer. Both IFA and ELISA showed good correlation with HAI for immune status evaluation and for quantitation of rubella antibodies. Technically the HAI was the most cumbersome to perform, whereas IFA was the least technically demanding. Originally, 308 samples were tested; 16 samples (5.2%) could not be evaluated by IFA because of a high level of nonspecific fluorescence. The strict requirement of controlling the temperature range (23 to 24 degrees C) during substrate hydrolysis proved to be a problem with the ELISA test in our laboratory.     

Phagocytosis and killing of staphylococci by human polymorphonuclear and mononuclear leucocytes.

The phagocytosis and killing of 3H-thymidine-labelled Staphylococcus aureus by polymorphonuclear leucocytes (PMNs) and monocytes (MNs) obtained from 50 health donors were evaluated. In addition, extracellular factors that might influence phagocytosis and killing were studied. The method described gave highly reproducible results. No significant difference was observed in the phagocytic and killing functions of a single donor's PMNs and MNs when studied several times in one day and longitudinally over a period of 1-12 weeks for six donors tested. Likewise, no signigicant difference in uptake and killing was observed when bacteria were opsonised with sera from 11 different normal donors. When Staph. aureus opsonised with normal serum was added to the leucocytes in a ratio of 10 bacteria: 1 leucocyte, the uptake by PMNs and MNs from 50 donors after 20 minutes' incubation was 85% +/- 7 standard deviation (SD) (range 75-98%) and 69% +/- 11 SD (range 54-90%), respectively. The rate of uptake by MNs in the first three minutes of the assay period was only 60% of that by PMNs.