Biomedical subjects
Publications and source records attributed to W Smith.
In summary, the data suggest that the traditional role of the radiologist as an expert consultant who provides an accurate written report is still the dominant perception. This study emphasizes the importance of development of communication skills and communication standards, with particular emphasis on written data as the single most important factor in keeping a strong clinician referral base.
With the implementation of the revised CPT4 coding structure on March 31, 1992, physicians and healthcare financial managers alike were reminded of the fact that more regulation often means less reimbursement. Authors Ciotti and Smith offer a personal look at how they struggled with the revised regulations and a guide to this "coding labyrinth."
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Three established human T-cell lines, HPB-MLT, HPB-ALL and PEER, were characterized and tested for their sensitivity to deoxyadenosine (dAdo) plus deoxycoformycin (dCoF). Phenotypic characterizations showed that all three cell lines had receptors for peanut agglutinin (PNA) and soybean agglutinin (SBA) while HPB-MLT and HPB-ALL, but not PEER, expressed the cortical thymocyte-specific marker, CD1. The majority of HPB-MLT cells (88%) expressed only CD4 but not CD8 antigen while most HPB-ALL cells (81%) co-expressed CD8 and CD4 antigens. PEER cells were negative for both CD8 and CD4. These three T cell lines showed differential sensitivity to dAdo plus dCoF in consequent tests. dAdo or dAdo plus dCoF (1 microM) had no effect on the growth, or DNA and RNA synthesis of HPB-MLT cells while the combination of dAdo and dCoF partially inhibited cellular growth and DNA and RNA synthesis of HPB-ALL cells. Further, the growth and DNA and RNA synthesis of PEER cells were strongly inhibited by the combination of dAdo and dCoF. This high sensitivity to dAdo plus dCoF reflected an immature phenotype of PEER cells despite its expression of CD3. Flow cytometric analysis of PEER cells demonstrated disappearance of the G2/M phase cells from the cell cycle after treatment with dAdo plus dCoF. Measurements of adenosine deaminase (ADA) and purine nucleoside phosphorylase (PNP) activities in all three cell lines, however, did not establish correlations between purine metabolizing enzyme activities and the differential sensitivities to dAdo plus dCoF. In sum, we report here three T-cell lines of different phenotypes that displayed significantly different sensitivities to dAdo plus dCoF which may facilitate investigations on the mechanisms of ADA deficiency.
Children born to human immunodeficiency virus (HIV)-infected mothers often do not live with a biologic parent because of drug use, illness, or death of the mother. Public health officials need to know the number and proportion of children who will require care by someone other than a biologic parent (alternative care giver). The Pediatric Spectrum of Disease project, conducted in six different geographic regions in the United States, assesses issues specific to HIV in children. Among the information being collected in this study are data regarding the primary care giver. Of 1683 children born to HIV-infected mothers and enrolled through 1990, 55% (937) were living with a biologic parent, 10% (169) with another relative, 28% (455) were in foster care, 3% (55) had been adopted, and 4% (67) lived in group settings or with other care givers. In all locations and for all racial/ethnic groups, children of mothers who used intravenous drugs were more likely to be living with an alternative care giver than were children of mothers who had not used intravenous drugs (odds ratio 4.15). However, there were striking variations by study location (odds ratio range 1.4 to 7.2). The data suggest that maternal drug use may be the most important factor determining whether a child lives with a biologic parent and that there are also regional differences in alternative care placement.
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Explore the source record for details and available documents.
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Two neutrophil defensins, rabbit peptides NP-1 and NP-5, were examined for their in vitro antibacterial activity against a panel of Gram-positive and Gram-negative organisms isolated from mastitic cows. Incubation for 60 minutes with 5 micrograms/ml of NP-1 in 10 mM sodium phosphate buffer resulted in substantial killing (greater than 95%) of all organisms tested. Although NP-5 was virtually inactive under these same conditions, supplementation of the incubation mixture with dilute nutrient media sensitized otherwise resistant organisms to this defensin. For both NP-1 and NP-5, bactericidal activity was dependent on time and concentration. Our findings demonstrate that the spectrum of defensin bactericidal activities include clinically important bovine pathogens. Further, the data demonstrate that NP-1 and NP-5, peptides which are homologous in 18 of their 33 residue positions, possess distinct mechanisms of action.
A bispecific mouse monoclonal antibody (mAb) that recognises carcinoembryonic antigen (CEA) with one binding site and vinblastine (VLB) with the other was used, and its in vivo immunosuppressive effect specific for anti-mouse immunoglobulin (Ig) was studied. The antibody was incubated with VLB at a molar ratio (MR) of 1:1, and administered i.v. to rabbits. Control animals received either the MAb alone, or the MAb with VLB covalently linked (MR 1:1), or the parental anti-CEA with equimolar amount of VLB. Seven days later, the rabbit anti-mouse Ig primary response was measured, and found to be almost 55% reduced in the animals that received the VLB 'loaded' MAb. In vivo kinetics and stability experiments revealed that the T1/2 of the MAb was 68 +/- 5 h, whereas free VLB disappeared within minutes. It was concluded that as soon as the drug dissociates from the antibody's binding site, it is rapidly removed. This problem was overcome by subcutaneously implanting osmotic mini-pumps containing VLB. The pumps released the drug at a constant rate for a period greater than 1 week, saturating the antibody's binding site. Under these conditions rabbits developed 80% less anti-mouse Ig antibodies when the bispecific antibody was administered (compared with the parental anti-CEA). The immunosuppression observed was specific for the mouse Ig, under conditions compatible with the full clinical therapeutic potential of the MAb. In conclusion, these experiments show, that it is possible to develop hybrid antibodies that can act as a 'lethal bait' to any specific lymphocyte in vivo, thus preventing undesirable responses against the xenogeneic MAb.
Prostaglandin H synthase (PGHS) activity within intrauterine tissues is considered to catalyze a critical step in prostaglandin (PG) biosynthesis at parturition. In sheep, the placenta is a major site of PG production throughout pregnancy, but little information is available concerning the cells that are responsible. Therefore we determined the distribution of immunoreactive (IR-) PGHS in ovine placental tissue obtained at different times of pregnancy using immunohistochemical techniques. In placentomes from early pregnancy (Days 30-54), IR-PGHS was present in maternal epithelial syncytium, but was not detectable in trophoblast cells. Between Day 54 and Day 100, the number of cells that stained positive for PGHS declined in the maternal epithelial layer in the body of the placenta, but IR-PGHS was present in maternal epithelial cells overlying the vascular cones of the placental hemophagous zone. It was also present in the chorionic fibroblasts, but remained undetectable from all classes of trophoblast cells. IR-PGHS was first detectable in the trophoblastic epithelium by Day 114. Between Day 119 and term the trophoblast mononuclear epithelial cells were intensely immunopositive for PGHS, although immunonegative binucleate cells were present. The maternal epithelium was immunonegative except during the last 7-10 days of pregnancy when PGHS immunostaining appeared in both basal and apical regions of the placenta. Thus, the cellular localization of IR-PGHS changes during ovine pregnancy, from predominantly maternal during the first half of gestation to undetectable and then to predominantly trophoblastic between Day 114 and term, suggesting a gestation-dependent change in sites of PG production during ovine pregnancy. Appearance of IR-PGHS in the trophoblast precedes activation of the fetal hypothalamic-pituitary-adrenal axis, generally considered to provide the trigger to the onset of parturition in sheep, and would therefore appear to be regulated through alternative pathways or mechanisms.
In this study the effect of gonadectomy and steroid treatment on the dorsal component of the incertohypothalamic dopamine system or nucleus A13 was assessed by immunocytochemistry using an antibody raised to tyrosine hydroxylase (TH). A computer graphic system interfaced to a microscope was used to count and measure the diameters of TH-positive neurons and display the data in the three-dimensional space of the nucleus. In males, castration resulted in a dramatic decrease in the reaction product representative of TH. The number of TH-positive cells in the A13 DA nucleus decreased to 25% of intact levels. In females, ovariectomy also caused an impressive loss in the TH-immunostainable material, but this was not indicated by a change in the total number of TH-positive neurons. In both sexes the loss in TH immunostain was confined mainly to the mid-portion of the nucleus. Hormone treatment restored the TH immunostain (cell number and size) to and/or above intact levels in both sexes. These data suggest that A13 TH immunostain is stimulated by gonadal steroids in male and female rats.
In this study, seventy-four adolescents in either a school, community or hospital based drug intervention program received and eight to nine week structured fitness activity class as an integrated element of their respective prevention or treatment program. Prepost assessments indicated significant gains in the field fitness tests of one mile run, 1 minute situp, 1 minute pushup, percent fat and flexibility for the total sample. Based upon prepost change on the one mile run time (less than 1:00) subjects were categorized as improvers (n = 38) and non-improvers (n = 36). Improvers demonstrated a significant increase in the self concept risk factor (Piers Harris Self Concept Scale) and a significant decrease in anxiety and depression risk factors (General Well-Being Scale) compared to the non-improvers. At posttest, the improvers self reported substance use patterns were significantly lower compared to the non-improvers for percentage of the sample who were multiple drug users and alcohol uses per week and were significantly higher for the percentage of the sample demonstrating total abstinence. These findings are suggestive of the usefulness of physical training as a supplemental intervention for adolescent substance abusers.
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This study examined the degree of serologic homology among mastitis pathogens. Antibodies were raised against the Rc mutant, Escherichia coli O111:B4 (strain J5) and affinity purified against lipopolysaccharide derived from the Ra mutant, Salmonella typhimurium TV119. These antibodies reacted with a battery of unrelated Gram-negative bacteria in whole cell ELISA. Bacteria with strong cross-reactions included a heterologous, smooth E. coli, Salmonella dublin, S. typhimurium, Salmonella newport, and Pseudomonas aeruginosa. Recognition of Klebsiella pneumoniae and Bordetella bronchisepticum was observed, but reactions were weaker than with the other isolates. The reduced recognition of these isolates probably reflects a masking effect of the bacterial capsule and variations in lipopolysaccharide structure. The polyclonal antibody did not recognize a Gram-positive isolate, Staphylococcus aureus. These immunoglobulins were then tested using whole cell ELISA against a panel of bacteria recovered from the mammary glands of cattle with clinical mastitis. Marked reactivity was noted against a variety of Gram-negative pathogens. Gram-positive isolates had lower recognition by Gram-negative core antigen specific immunoglobulin. The results suggest immunization with rough mutant bacteria may have broad application in the prevention of coliform mastitis.
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