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S Hart

Publications and source records attributed to S Hart.

At least 91 records · Page 5Linked to original sources
PubMed1992

Immunoglobulin idiotype expression in reactive lymphoid tissues and B-cell lymphomas.

In an investigation of the immunoglobulin idiotypic expression of non-tumour and neoplastic B lymphocytes in situ, fresh-frozen specimens of reactive tonsils, lymph nodes and B-cell malignant lymphomas (B-MLs) from Japanese patients were studied immunohistochemically with 39 different anti-idiotype antibodies. In reactive lymphoid tissues, while idiotype-bearing cells were largely distributed sparsely in follicles and perifollicular areas, some were heavily crowded in particular germinal centres (GCs), suggesting the presence of oligoclonal proliferations of B-cells in GCs. Forty-eight out of 100 B-MLs reacted with anti-idiotype antibodies. This proportion was significantly higher than those reported in Western cases (27-36%), indicating that Japanese B-MLs share public idiotypes much frequently than western cases. The idiotypes demonstrated in these lymphomas, in contrast to those not expressed in any B-ML, were found much commonly in non-tumour lymphocytes, suggesting that such public idiotypes as were common in B-MLs were frequently shared by normal B-lymphocytes.

Antibodies↗
PubMed1992

Renal pyelectasis in pregnancy: correlative evaluation of fetal and maternal collecting systems.

OBJECTIVE: The current study is aimed at assessing the possibility of a statistical relationship between fetal and maternal collecting system dilatation during pregnancy. STUDY DESIGN: Two hundred thirty consecutive pregnant women and their fetuses (20 to 40 weeks' gestation) were simultaneously examined by ultrasonography. The renal collecting systems were measured, and the frequency of dilatation was subjected to chi 2 analysis. The temporal incidence of fetal pyelectasis was compared with the maternal incidence. RESULTS: Dilatation of maternal collecting systems was detected in 91 of 230 patients (40%) and fetal pyelectasis occurred in 60 of 230 (26%). Fetal pyelectasis was 5.6 times more likely to occur in fetuses of mothers with dilated collecting systems. Furthermore, the temporal incidence of fetal pyelectasis throughout pregnancy appeared similar to that of maternal pyelectasis. CONCLUSION: This study points out the existence of a statistically significant association between maternal and fetal collecting system dilatation during pregnancy.

Chi-Square Distribution↗
PubMed1992

Construction of an insertional-inactivation cloning vector for Escherichia coli using a Rhodococcus gene for indigo production.

pSLH8, an insertional-inactivation cloning vector for Escherichia coli has been constructed by inserting a pigment gene (probably encoding an indole dioxygenase) from Rhodococcus sp. ATCC 21145 into pUC18. Wild-type E. coli colonies containing pSLH8 produce insoluble indigo and turn dark blue on unsupplemented LB agar. Insertion of DNA fragments into the unique BamHI, EcoRI, EcoRV, HindIII, PstI, SphI and SstI polylinker cloning sites disrupts the reading frame of the fully sequenced pigment gene and results in unpigmented colonies. pSLH8 may be an attractive alternative to pUC18 and similar plasmids because it does not require specifically mutated host strains or an expensive substrate for colour development.

Base Sequence↗
PubMed1992

Identification of indigo-related pigments produced by Escherichia coli containing a cloned Rhodococcus gene.

Pigments produced by Escherichia coli containing a cloned piece of DNA from Rhodococcus sp. ATCC 21145 were extracted in chloroform and separated into blue and pink components. Evidence from TLC, NMR spectroscopy, absorption spectrum analysis and solubility behaviour suggested that the blue pigment was indigo and the pink pigment was indirubin, a structural isomer of indigo. The proposed pathway for pigment production on LB agar involves the conversion of tryptophan to indole by tryptophanase of E. coli and the oxidation of indole to indigo by the product of the cloned Rhodococcus DNA insert.

Chromatography, Thin Layer↗
PubMed1992

An exploratory examination of the Parent-initiated Motivational Climate Questionnaire.

The purpose of this study was to examine the factor structure and internal reliability of the Parent-initiated Motivational Climate Questionnaire among 112 boys and 98 girls, young adolescents, and older adolescents. The questionnaire had a meaningful 3-factor structure and showed acceptable internal reliability. There was a significant difference between how boys and girls perceived their parents' reactions to their learning new physical skills. In contrast to boys, girls thought that both their mothers and fathers focused on improvement and self-satisfaction during the learning process and deemphasized learning without effort and worrying about making mistakes. Age did not significantly affect the perceptions the individuals had of their parents' convictions about their learning in the physical domain.

Adolescent↗
PubMed1992

Effect of age, family status, and physical activity on selected dietary components of TAC pilots.

This study gathered dietary data on Tactical Air Command (TAC) pilots for descriptive and analytic purposes. One hundred eighteen TAC pilots from five bases were interviewed concerning their diet, age, family configuration, and exercise level. Dietary information was recorded using the PruCal 3-day dietary report form, while the remaining information was recorded on a personal interview form. Pilots were grouped according to age (three levels), family configuration (three levels), and exercise (three levels). The groups in each category were tested (analysis of variance) for differences in their intake of protein, carbohydrates, fat, alcohol, and caffeine, and for demographic differences. Differences between exercise groups were found for weight and carbohydrates consumed. Age group differences were seen in alcohol intake and fat consumption. Further findings suggest pilots do not have diets which meet dietary guidelines. There appears to be a need for nutrition education, dietary modification programs, and further study of the diets of TAC pilots.

Adult↗
PubMed1992

Changes in rat leukocyte populations in peripheral blood, spleen, lymph nodes, and synovia during Erysipelas bacteria-induced polyarthritis.

Kinetics of leukocyte subsets were followed for several weeks in rats suffering from polyarthritis induced by experimental infection with erysipelas bacteria (Erysipelothrix rhusiopathiae, serovar 2, strain T28). A marked leukocytosis was found in peripheral blood, and, with some delay, in the synovia and draining lymph nodes of affected joints. In the lymphoid organs tested considerable blast formation of lymphoid cells with a paucity of polymorphonuclear granulocytes was found, while the latter represented the majority of leukocytes in acutely inflamed joints. Cells isolated from spleen showed only moderate and transient alterations in proportions of subpopulations during the first week after inoculation of erysipelas bacteria. In contrast, cells isolated from synovia of inflamed joints and draining lymph nodes displayed more intense and longer lasting alterations: In arthritic animals, the proportion of MHC class II-positive lymphocytes generally increased and remained elevated at least during the first three weeks of the disease. Spontaneous release of IL-2 from cells isolated up to 20 days post induction of the arthritis indicated a considerable activation of lymphocytes in vivo. Interestingly, with exception of synovia, the relative amount of T-lymphocytes including their major CD4+ and minor CD8+ subsets showed little alteration during the course of the disease. Much more pronounced were the rapidly and the extent the membrane Ig-positive B-lymphocytes increased in the synovia as well as in the lymph nodes. Thus, B-lymphocytes may be of particular relevance for elucidating pathomechanisms of erysipelas polyarthritis.

Animals↗
PubMed1991

Ig VH gene expression among human follicular lymphomas.

Thirty-six randomly selected cases of low grade follicular lymphoma (FL) were analyzed for Ig heavy chain variable region (VH) gene expression. Assignment to one of the six human VH gene families (VH1 to VH6) was made with a polymerase chain reaction-based technique using family-specific leader primers. The frequency of VH family use in FL was found to be similar to that reported for normal peripheral blood lymphocytes and is therefore also roughly proportional to VH family size. To evaluate expression within an individual family, all of the lymphoma VH genes from the middle size VH4 family were sequenced and compared with previously published sequences. Of these eight lymphoma VH sequences, six were most closely related to just two of the 10 known functional VH4 germline genes. Nonrandom usage by FL of the JH3, JH4, and JH5 joining segments was also observed. Nucleotide sequences were also determined for 10 randomly selected lymphoma VH genes from the large VH3 family. With one possible exception, none of these lymphoma VH sequences appear to represent any of the VH3 genes that may be preferentially used in the fetal repertoire.

Base Sequence↗
PubMed1991

Autoantibody activity of immunoglobulins isolated from B-cell follicular lymphomas.

Previous work with monoclonal Igs (MIgs) has demonstrated that a high proportion of paraproteins bind to self-antigens such as the Fc fragment of IgG, Ii blood group antigens, cytoskeleton proteins, DNA, and myelin-associated glycoprotein (MAG). Recent work in CLL indicates that CD5+ B lymphocytes are frequently committed to production of autoantibodies. We have examined the antibody specificity of MIgs derived from the tumor cells of 31 different patients with CD5- B-cell lymphomas. Our results indicate that the tumor cells from 8 of these 31 patients (25.8%) express Igs with autoantibody activity. In two cases antibody activity was multispecific. In four cases, antibody activity was exclusively directed against the Fc fragment of IgG, whereas the two other cases bound to both Fc fragment of IgG and nuclear antigens. Most non-Hodgkin's lymphomas (NHL) are derived from CD5- B cells. These results indicate that like CLL, NHL also express Igs that frequently have autoantibody activity.

Antibodies, Monoclonal↗
PubMed1991

Expression of shared idiotypes in chronic lymphocytic leukemia and small lymphocytic lymphoma.

The expression of shared idiotypes (Slds) has been studied on malignant CD5+B cells from patients with chronic lymphocytic leukemia (CLL) and small lymphocytic lymphoma (SLL) using a panel of 37 murine monoclonal antibodies previously demonstrated to be reactive with Slds derived from follicular B-cell lymphomas. Thirteen anti-Slds identified tumor cells from 31 of 105 (30%) CLL patients and 4 of 6 SLL patients. In comparison, the same panel of anti-Slds is reactive with 33% of follicular and diffuse B-cell lymphomas. Ten of these anti-Slds reacted with CLL cases at similar frequencies to that of the B-cell lymphomas. Two anti-Slds, which are known to react with autoantibodies, were significantly more prevalent in CLL than in B-cell lymphomas. These data confirm the presence of Slds in CLL and provide further evidence of an association between CLL and autoimmunity. The identification of a panel of antibodies reactive with a significant number of CLL and SLL patients will facilitate the application of anti-idiotype antibody therapy in these diseases.

Adult↗
PubMed1991

[Thrombocyte aggregation in the cat].

Platelet aggregation in healthy and sick cats after adding various aggregating agents is described. Feline platelets aggregate irreversibly in response to 0.15-1.0 micrograms/ml collagen, 1 microM ADP, 0.3 IU/ml test-thrombin and 0.71 NIH/ml Topostasin. Epinephrine, ristocetin and kaolin failed to cause aggregation. The aggregation function was decreased in a cat with liver damage and icterus; in 2 cats with uremia platelet aggregation was normal. Acetylsalicylic acid (ASA) (10 mg/kg iv) inhibits platelet aggregation in the presence of collagen in low concentrations; high concentrations of collagen succeeded in inducing platelet aggregation.

Adenosine Diphosphate↗
PubMed1990

Expression of shared idiotypes by paraproteins from patients with multiple myeloma and monoclonal gammopathy of undetermined significance.

Twenty-nine murine monoclonal antibodies have been produced that react with shared idiotypes expressed by B-cell lymphomas and leukemias. We tested this panel of antibodies for reactivity with the paraproteins from 32 patients with multiple myeloma and 10 patients with monoclonal gammopathy of undetermined significance (MGUS). Thirteen of 42 paraproteins reacted with at least one antibody in this panel of anti-idiotypic antibodies. Six different anti-idiotypes demonstrated reactivity with the paraproteins. A similar frequency of reactivity was found for both myeloma and MGUS proteins. One antibody, S30-47, reacted with 6 of 32 (19%) of the paraproteins from patients with multiple myeloma, whereas this anti-idiotype only bound to 3% of non-Hodgkin's B-cell lymphomas and no cases of chronic lymphocytic leukemia. This anti-idiotype reacted with both components of a biphenotypic paraprotein (IgG kappa and IgG lambda) in one patient. In each of nine patients tested, plasma cells isolated from bone marrow were shown to be reactive with the same anti-idiotype we found to react with the paraprotein. Antishared idiotype antibodies may provide useful reagents for studies of patients with monoclonal gammopathies.

B-Lymphocytes↗
PubMed1990

Structure of a Rhodococcus gene encoding pigment production in Escherichia coli.

A 2.1 kbp DNA fragment from Rhodococcus strain ATCC 21145 gave rise to the production of blue and pink pigments in Escherichia coli when cloned downstream of a strong promoter. The sequence of this DNA fragment contains a single open reading frame with a putative ribosome-binding site, potentially coding for a single protein of Mr 42,560. Deletion analysis and in vitro transcription-translation experiments support the hypothesis that pigment production in E. coli is due to a single enzyme whose catalytic activity is still unknown. This small pigment gene may become useful for the development of a new generation of chromogenic cloning vectors which do not require expensive substrates for the detection of gene expression.

Amino Acid Sequence↗
PubMed1990

Post-transfusion thrombocytopenia: its duration in splenic and asplenic individuals.

Previous work in our department showed that after blood transfusion, the platelet count often falls to levels which are clinically significant. The probable site of platelet sequestration was identified as the spleen, and post-transfusion thrombocytopenia was prevented by blood filters which remove microaggregate debris from the donor blood. Since the duration of the thrombocytopenia has not been investigated, the purpose of the present study was to establish the rate of onset and duration of post-transfusion thrombocytopenia following packed red blood cell transfusions. In addition, the effect of spleen size, patients' diagnosis and post-transfusion history were examined. These observations provide interesting new data on the mechanisms involved in this phenomenon.

Humans↗
PubMed1990

Early experience with needle localization and biopsy of mammographic lesions.

Increasing awareness of the value of mammography by both physicians and the public has resulted in women presenting more commonly with impalpable breast lesions. This study reviews the radiology and pathology of 58 such lesions biopsied by the Monash Medical Centre Breast Unit between August 1987 and October 1988. Abnormal mammograms were reported by one of two independent radiologists in the normal course of practice and placed into one of five categories according to the radiological appearance. Those lesions scoring greater than or equal to 3 were then needle localized, excised and examined histologically. All mammograms were later reported as unknowns by the other radiologist and similarly scored. Sixteen (28%) of these lesions were invasive or in situ carcinoma and of these a significant number were scored differently by the two radiologists. The results indicate that needle localization biopsy of suspicious mammographic lesions is a safe, accurate method for the diagnosis of early breast cancer. The results also show significant variation between radiologists and demonstrate the need for double reading of screening mammographic films. It is suggested that doubtful lesions require more extensive work-up with compression/magnification and other special views, the aim being more accurate radiological assessment and a reduction in the benign biopsy rate.

Biopsy↗
PubMed1990

Overuse syndromes of the upper extremity in interpreters for the deaf.

Fourteen of 80 interpreters (18%) for deaf students at a national center on deafness sought medical care for painful conditions of the upper extremity; 11 others (14%) had less severe or transient symptoms. The conditions were brought on by repetitive use and were relieved by rest. All represented overuse syndromes. Tendinitis, fasciitis, synovitis, and nerve entrapment were encountered most often. Conservative treatment (eg, physical therapy, splinting, medications) was of little or no value. Only rest relieved symptoms. Surgery was rarely indicated. The most reasonable approach to treatment would, therefore, seem to be prevention. Suggested methods for avoidance of pain include limiting the duration of interpreting sessions, technique modification, and resistance exercises to increase endurance.

Arm↗
PubMed1989

Shared idiotypes expressed by human B-cell lymphomas.

Each B-cell lymphoma expresses a surface immunoglobulin that contains unique antigenic determinants (idiotypes). We have produced 199 murine monoclonal antibodies reactive with the idiotypes isolated from 67 patients with follicular small-cleaved-cell lymphoma. These antiidiotype antibodies were analyzed for their ability to react with lymphoma cells from patients other than the one against which each antibody was made. Twenty of the 199 antiidiotype antibodies were reactive with lymphoma cells from more than one patient. Depending on the antibody, the frequency of idiotype sharing ranged from 0.6 to 6.2 percent of B-cell lymphoma tumors evaluated. Tumors could be grouped into distinct families on the basis of their reactivity with these antibodies. In the aggregate, the 20 antibodies reacted with a total of 49 of 150 B-cell lymphomas (33 percent), including 30 of 110 follicular small-cleaved-cell lymphomas (27 percent). Many of these shared idiotypes were expressed by more than one histopathological subtype of lymphoma. We conclude that a panel of antibodies reactive with shared idiotypes can be produced for patients with B-cell lymphoma, obviating the need to produce an antiidiotype antibody for each patient.

Antibodies, Anti-Idiotypic↗