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Biomedical subjects

D Kaplan

Publications and source records attributed to D Kaplan.

At least 127 records · Page 7Linked to original sources
PubMed1989

Rheumatoid factor in patients with systemic lupus erythematosus.

One hundred sixty-six patients with systemic lupus erythematosus (SLE) were surveyed and their sera tested for the presence of rheumatoid factor (RF). Fifteen were positive whenever tested, with titers of at least 1:40; the remainder were either positive only in titers of 1:20, were inconsistently positive or were persistently negative. The former group were less likely to have severe manifestations of SLE, less likely to have required treatment with "high-dose" steroids or a cytotoxic drug, and less likely to have had an episode of herpes zoster. We conclude that in patients with SLE, RF may be a reflection of relative immune competence so that they are partially protected against the more serious manifestations of SLE and the development of herpes zoster.

Adult↗
PubMed1988

The effect of paternal social support on maternal disruption caused by childhood asthma.

Baseline data obtained from a study of 228 low-income Black and Hispanic mothers of children with asthma were analyzed to test the hypothesis that the presence of adults in the household, and paternal involvement in asthma care would be associated with less disruption of mothers' daily activities due to the child's asthma. The data were analyzed using multiple regression techniques. We controlled for other variables that might affect the amount of disruption that mothers reported, including the child's age and severity of asthma. The mere presence of other adults in the household, including the father, was not significantly associated with disruption. The frequency of the father's involvement in the care of the child's asthma was inversely associated with disruption regardless of his presence in the household. Hispanic ethnicity and severity of the child's asthma were directly associated with disruption while the age of the child was inversely associated with disruption. We conclude that it is a specific type of assistance (sharing asthma tasks) rendered by fathers living within or outside of the household that reduces disruption reported by mothers. The study suggests that health care providers can improve education and counseling for families who have a child with asthma by emphasizing to fathers their importance in the care of asthma, and by helping them identify specific actions they can take to manage the child's disease.

Adult↗
PubMed1988

Multiple hairy pacinian neurofibromas (nerve-sheath myxomas).

Pacinian neurofibromas are unusual tumors with components that resemble Vater-Pacini corpuscles and are probably a variant of nerve-sheath myxoma. Lesions composed predominantly of these structures have occurred on or near the buttocks in three previously reported cases; however, all were solitary and congenital. Two of these patients, with lesions that closely resembled mature Vater-Pacini corpuscles, had underlying skeletal anomalies. Our patient had multiple hairy pacinian neurofibromas (nerve-sheath myxomas) on the buttocks that were not associated with radiographic evidence of and underlying skeletal anomaly. Skeletal anomalies may be associated with "sacrococcygeal paciniomas" but probably not with true pacinian neurofibromas.

Buttocks↗
PubMed1988

Cellular proteins that associate with the middle and small T antigens of polyomavirus.

We have used two-dimensional gel electrophoresis to analyze in more detail the cellular proteins which associate with the middle and small tumor antigens (MT and ST, respectively) of polyomavirus. Proteins with molecular masses of 27, 29, 36, 51, 61, 63, and 85 kilodaltons (kDa) that specifically coimmunoprecipitated with MT were identified on these gels. The 36-, 51-, 61-, 63-, and 85-kDa proteins are probably the same as the proteins of similar sizes previously reported by a number of groups, whereas the 27- and 29-kDa proteins represent proteins that are heretofore undescribed. The 27- and 29-kDa proteins were abundant cellular proteins, whereas the others were minor cellular constituents. The association of each of these proteins with MT was sensitive to one or more mutations in MT that rendered it transformation defective. The association of the 85-kDa protein was the most sensitive indicator of the transformation competence of MT mutants. In addition, the 85-kDa protein was the only associated protein whose association with MT changed consistently in parallel with MT-associated phosphatidylinositol kinase activity. Furthermore, the fraction of the 85-kDa protein which was found associated with the MT complex contained 15 to 20% of its phosphate content on tyrosine. The 36- and 63-kDa proteins complexed with both polyomavirus MT and ST and comigrated on two-dimensional gels with two simian virus 40 ST-associated proteins originally described by Rundell and coworkers (K. Rundell, E. O. Major, and M. Lampert, J. Virol. 37:1090-1093, 1981). None of the other MT-associated proteins associated significantly with ST.

Antigens, Polyomavirus Transforming↗
PubMed1987

Evidence for two distinct phosphatidylinositol kinases in fibroblasts. Implications for cellular regulation.

Phosphatidylinositol (PtdIns) kinase activities from non-transformed and polyoma-middle-T-transformed murine fibroblasts were examined. Both normal and transformed 3T3 fibroblasts have two PtdIns kinases, which can be separated by anion-exchange chromatography. One of these activities (Type I) has a Km for ATP of 10 microM, is resistant to inhibition by adenosine, AMP or ADP, and is inhibited by non-ionic detergents. The other activity (Type II) has a somewhat higher Km for ATP (35 microM) and is inhibited competitively by ADP, AMP and adenosine at concentrations suggesting regulation of this activity by the energy charge of the cell. The Type II PtdIns kinase is activated by non-ionic detergents. We have previously reported the specific association of a PtdIns kinase activity with polyoma-middle-T immunoprecipitates [Whitman, Kaplan, Schaffhausen, Cantley & Roberts (1985) Nature (London) 315, 239-242; Kaplan, Whitman, Schaffhausen, Raptis, Garcea, Pallas, Roberts & Cantley (1986) Proc. Natl. Acad. Sci. U.S.A. 83, 3624-3628]. Comparison of the immunoprecipitated PtdIns kinase with the activities identified by ion-exchange chromatography indicates that it is the Type I enzyme which specifically associates with the middle-T/pp60c-src complex. This PtdIns kinase activity is separable from both middle T and pp60c-src. Type I PtdIns kinase also associates with pp60v-src immunoprecipitates from Rous-sarcoma-virus-transformed cells. Furthermore, this PtdIns kinase appears to co-precipitate with partially purified platelet derived growth factor (PDGF) receptor. The amount of this activity found in anti-phosphotyrosine immunoprecipitates or in wheat-germ-lectin-agarose precipitates is increased 50-fold by stimulation of quiescent Balb/C 3T3 fibroblasts with PDGF. These results suggest that the Type I PtdIns kinase is regulated by agents which affect cell growth and transformation, whereas the Type II PtdIns kinase may be regulated by the local [ATP]/[ADP] ratio.

1-Phosphatidylinositol 4-Kinase↗
PubMed1987

Proton magnetic resonance characterization of phoratoxins and homologous proteins related to crambin.

The mistletoe protein toxins ligatoxin, phoratoxins A and B, and viscotoxins A3 and B have been investigated by 1H NMR spectroscopy at 300 and 600 MHz. The five polypeptides define a set of closely related homologues, containing 46 amino acid residues each, in a structure constrained by three cystine bridges. Their methyl and aromatic spectra were analyzed and a number of signals identified and assigned via comparative criteria, two-dimensional chemical-shift correlated spectroscopy, acid-base titration, and proton Overhauser experiments in 1H2O. The spectra indicate a compact globular conformation and a common folding pattern for the toxins. In particular, use was made of well-resolved aliphatic and aromatic resonances in order to compare the mistletoe proteins with the thionins, a set of homologous toxins from gramineae, and with crambin, a closely related polypeptide from a crucifer, which we have previously studied by NMR. We observe that while all the investigated proteins have very similar secondary and tertiary structures, they differ widely in their dynamic characteristics as probed by the amide NH 1H-2H exchange kinetics in deuteriated solvents; thus, while crambin and the thionins exhibit very fast isotope exchange, the kinetics for the mistletoe toxins are slow, with some NH groups showing exchange half-lives that extend up to several days at pH* 5.8 or that are too long to be measurable at ambient temperature. The temperature dependence of the 1H NMR spectrum also indicates that the toxins are endowed with a thermally very stable native (ground-state) structure, with little evidence of large amplitude structural breathings up to approximately 370 K, although irreversible chemical degradation (denaturation) becomes evident at temperatures greater than or equal to 350 K. It is concluded that the mistletoe toxins afford valuable rigid structures for NMR conformational studies.

Amino Acid Sequence↗
PubMed1987

Quantitative validation of cineangiographic biplane axial oblique right ventricular volume measurement.

Axial cranial oblique biplane views of the right ventricle (RV) permit unique assessment of the RV outflow tract, relationship of the great vessels, and anatomy of the proximal pulmonary arteries. This view may also be useful in assessment of RV free wall and RV septal wall motion. However, the accuracy of volumes derived from biplane angiocardiography with the use of the axial cranial oblique projection has not been adequately validated or compared to conventional views. Nineteen RV animal casts whose volume was determined by water displacement were filmed in conventional posteroanterior/lateral (PA/Lat), 30-degree right anterior oblique/60-degree left anterior oblique (30 degrees RAO/60 degrees LAO) views and in angulated 35-degree right anterior oblique/55-degree left anterior oblique/30-degree cranial (35 degrees RAO/55 degrees LAO/30 degrees Cr) view. Tracings of biplane cast images were analyzed for RV volume by Simpson's rule. RV cast volume was significantly overestimated by 12.2 +/- 6.8, 6.0 +/- 5.3, and 9.3 +/- 9.5 ml in PA/Lat, 30 degrees RAO/60 degrees LAO, and 35 degrees RAO/55 degrees LAO/30 degrees Cr views, respectively. The correlation coefficient (r) and the standard error of the estimate (SEE) for true vs calculated volume was 0.96, 0.98, and 0.97, and 6.8, 5.2, and 7.3 ml, respectively, for PA/Lat, 30 degrees RAO/60 degrees LAO, and 35 degrees RAO/55 degrees LAO/30 degrees Cr views. Although there was a high correlation of angiographic volumes with true volume in all three views, the 30 degrees RAO/60 degrees LAO projection had the most ideal regression characteristics with highest r value and the lowest SEE.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1987

Epithelial impedance analysis in experimentally induced colon cancer.

Epithelial impedance analysis was used to measure the alterations in resistance of the large bowel in a murine model of large bowel cancer. The technique was able to resolve the epithelial resistance from the total resistance of the bowel wall. A progressive decrease in resistance of the bowel epithelium occurs during carcinogenesis induced with dimethyhydrazine. About a 21% decrease in epithelial resistance from 22.0 +/- 1.3 omega.cm-2 to 17.5 +/- 1.1 omega cm-2 (p less than 0.025) was observed after 20 wk of carcinogen administration. The sensitivity of the technique in detecting altered epithelial resistance in premalignant bowel mucosa was improved by examining the impedance profile in a sodium-free Ringer's solution where the epithelium of control colons had a resistance of 24.4 +/- 1.8 omega.cm-2 compared with 19.0 +/- 1.1 omega.cm-2 (p less than 0.02) in colons from animals treated for only 4 wk with the carcinogen. Epithelial impedance analysis would seem to be a sensitive technique capable of identifying changes in the electrical properties or the large bowel early in disease states.

Animals↗
PubMed1987

Chelating Properties of Extracellular Polysaccharides from Chlorella spp.

Chlorella stigmatophora LB 993 was grown in artificial seawater under controlled conditions. The production of cell wall polysaccharides attached to the cells and dissolved in the growth medium was monitored during algal growth. Preliminary characterization of the dissolved polysaccharides of C. stigmatophora and other Chlorella species is presented. The capacity of dissolved polysaccharides of C. stigmatophora to bind toxic heavy metals was also studied and compared with that of polysaccharides produced by other marine Chlorella species. The differences in metal-complexing capacity observed for dissolved polysaccharides obtained from various Chlorella species is attributable to differences in the composition of the polysaccharides, notably the uronic acids content.

Journal Article↗
PubMed1987

Characterization of middle T antigen expressed by using an adenovirus expression system.

The adenovirus Ad5(pymT) has been used to express middle T antigen at very high levels in 293 cells. The middle T antigen produced was localized to membranes and was modified in the same way as that expressed in polyoma virus-infected mouse cells. It was phosphorylated in vivo on serine residues and in vitro on tyrosine residues. The in vivo phosphorylations occurred between residues 223 and 275. The middle T antigen encoded by A d5(pymT) was phosphorylated in vitro in a complex with human pp60c-src. Interestingly, the extreme overexpression of middle T antigen did not cause a parallel increase in the amount of complex; most of the pp60c-src remained unassociated. Immunoaffinity purification resulted in approximately 100 micrograms of middle T antigen from a 100-mm tissue culture dish. Several cell proteins copurified with the Ad5(pymT)-derived middle T antigen. Two of these, the 74- and 63-kilodalton species, are of particular interest because they were also purified from mouse tumors expressing middle T antigen.

Adenoviruses, Human↗
PubMed1987

A school health education program for children with asthma aged 8-11 years.

It was hypothesized that a health education program for children with asthma aged 8-11 years that was delivered in elementary schools, would increase children's asthma management skills, self-efficacy and influence on parents' management decisions; reduce school absences and improve school performance. The study population consisted of 239 low-income, predominantly Hispanic and black children from 12 elementary schools (six experimental and six control) in New York City. Parents did not attend educational sessions but received written materials. The program emphasized the child's responsibility for recognizing symptoms and taking appropriate management steps. Follow-up data obtained one year after the program showed that compared to controls experimental group children had higher scores on an index of asthma management (p less than 0.05), greater self-efficacy with respect to asthma management skills (p less than 0.05), more influence on parents' asthma management decisions (p less than 0.05), better grades in school (p = 0.05), and fewer episodes of asthma (p less than 0.01) of shorter average duration (p less than 0.01). No differences were observed for changes in number of school absences. These findings show that asthma health education designed for delivery to children can significantly increase management skills, reduce symptoms of asthma, and improve school performance.

Asthma↗
PubMed1987

Development of clinical criteria for osteoarthritis.

Clinical criteria for the classification of osteoarthritis (OA) in the knee have been developed and the use of algorithms has been proposed. Criteria for the classification of OA in the hand and hip are still being developed.

Hand↗
PubMed1986

Colonic epithelial impedance analysis in a murine model of large-bowel cancer.

Death rates from large-bowel cancer have remained essentially unchanged over the past 40 years because the diagnosis is made late, after the tumor has spread to other sites. This study was undertaken to examine whether alterations in mucosal electrical capacitance precede the development of gross malignancy, since this parameter may reflect functional or structural changes in the colonocyte plasma membrane, which is of importance in the regulation of cell growth. Distal colonic mucosal capacitance was decreased at low frequencies after only four weeks of treatment with the carcinogen dimethylhydrazine in C1 mice. Alterations in electrical capacitance may be a useful marker in identifying patients with a propensity to develop large-bowel cancer.

Animals↗
PubMed1986

Managing better: children, parents, and asthma.

To evaluate a health education program to improve family management of asthma, 310 children with asthma and their 290 parents were randomly assigned to a program or control group. Program families participated in health education designed to resolve specific management problems and build self-confidence in the ability to manage asthma. Following education, program parents scored better on an asthma self-management index than parents in the control group (+1.57 versus -0.83, P less than 0.0001). Program parents also scored better on two subindices of the self-management index: attack management (+0.87 vs. +0.42, P less than 0.05) and preventive measures (+0.42 vs. -0.35, P less than 0.05). Also, program parents reported significantly more use of guidelines to determine appropriate levels of physical activity for children. Following education, program children reported more use of three management steps than control children: productive cough or postural drainage (59% vs. 35%, P less than 0.004), breathing and relaxation exercises (80% vs. 65%, P less than 0.05), and attempts to stay calm (12% vs. 2%, P less than 0.05). Program children reported significantly less worry than control children about the limitations asthma imposes and about making mistakes at school.

Adolescent↗
PubMed1986

Experimental evaluation of absorbable copolymer staples for hysterectomy.

Absorbable copolymer staples of three different variants were tested for retention of tensile strength after implantation into the peritoneal cavity of rats. One type maintained tensile strength for two weeks, but then lost it rapidly over the next week. The same three staple compounds were further compared after use for vaginal vault closure during ovariohysterectomy in adult sheep. In all ewes the absorbable staples were effective in providing a stable vaginal cuff closure. The postoperative tissue reaction was minimal. The goal of developing an absorbable staple that would degrade rapidly without compromising wound stability was achieved.

Absorption↗