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Biomedical subjects

J Bartley

Publications and source records attributed to J Bartley.

16 recordsLinked to original sources
PubMed1992

Characterization of a type II collagen gene (COL2A1) mutation identified in cultured chondrocytes from human hypochondrogenesis.

A subtle mutation in the type II collagen gene COL2A1 was detected in a case of human hypochondrogenesis by using a chondrocyte culture system and PCR-cDNA scanning analysis. Chondrocytes obtained from cartilage biopsies were dedifferentiated and expanded in monolayer culture and then redifferentiated by culture over agarose. Single-strand conformation polymorphism and direct sequencing analysis identified a G----A transition, resulting in a glycine substitution at amino acid 574 of the pro alpha 1(II) collagen triple-helical domain. Morphologic assessment of cartilage-like structures produced in culture and electrophoretic analysis of collagens synthesized by the cultured chondrocytes suggested that the glycine substitution interferes with conversion of type II procollagen to collagen, impairs intracellular transport and secretion of the molecule, and disrupts collagen fibril assembly. This experimental approach has broad implications for the investigation of human chondrodysplasias as well as human chondrocyte biology.

Alleles↗
PubMed1990

Determination of apical membrane polarity in mammary epithelial cell cultures: the role of cell-cell, cell-substratum, and membrane-cytoskeleton interactions.

The membrane glycoprotein, PAS-O, is a major differentiation antigen on mammary epithelial cells and is located exclusively in the apical domain of the plasma membrane. We have used 734B cultured human mammary carcinoma cells as a model system to study the role of tight junctions, cell-substratum contacts, and submembraneous cytoskeletal elements in restricting PAS-O to the apical membrane. Immunofluorescence and immunoelectronmicroscopy experiments demonstrated that while tight junctions demarcate PAS-O distribution in confluent cultures, apical polarity could be established at low culture densities when cells could not form tight junctions with neighboring cells. In such cultures the boundary between apical and basal domains was observed at the point of cell contact with the substratum. Immunocytochemical analysis of these cell-substratum contacts revealed the absence of a characteristic basement membrane containing laminin, collagen (IV), and heparan sulfate proteoglycan. However, serum-derived vitronectin was associated with the basal cell surface and the cells were shown to express the vitronectin receptor on their basolateral membranes. Additionally, treatment of cultures with antibodies against the vitronectin receptor caused cell detachment. We suggest, then, that interactions between vitronectin and its receptor, are responsible for establishment of membrane domains in the absence of tight junctions. The role of cytoskeletal elements in restricting PAS-O distribution was examined by treating cultures with cytochalasin D, colchicine, or acrylamide. Cytochalasin D led to a redistribution of PAS-O while colchicine and acrylamide did not. We hypothesize that PAS-O is restricted to the apical membrane by interactions with a microfilament network and that the cytoskeletal organization is dependent upon cell-cell and cell-substratum interactions.

Actin Cytoskeleton↗
PubMed1990

Noncompliance with Universal Precautions Policy: why do physicians and nurses recap needles?

In 1987 the Centers for Disease Control published a Universal Precautions Policy establishing blood and body fluid procedures to be used consistently with all patients. An important and unequivocal Universal Precautions Policy recommendation with regard to avoidance of needlestick injuries is that needles should never be recapped. We examined the recapping-related attitudes and behaviors of physicians and nurses at four large teaching hospitals with patients with acquired immunodeficiency syndrome and with Universal Precautions Policy in-service training programs. Compliance was found to be considerably less than optimal. According to unannounced needle counts in disposal boxes, the percentage of recapped needles was always greater than 25% and exceeded 50% in four instances. Recapping was related to inadequate knowledge, concerns about personal risk, forgetfulness, being "too busy" to follow the Universal Precautions Policy, and the misperception that recapping is a way to avoid needlestick injury. Strategies are suggested to improve and supplement traditional in-service education.

Communicable Disease Control↗
PubMed1990

Defining successful performance among pediatric residents.

The pediatric literature has documented a growing attention to defining the nature and quality of residency training. The critical incident technique, a method widely accepted in industrial settings, was used in this study to determine attitudes and behaviors deemed critical for successful performance of residents in a pediatric training program. Structured interviews with 17 senior teaching faculty produced descriptions of resident behavior that were classified into the following mutually exclusive categories: commitment to learning, clinical judgment, communicating medical information, recognition of limits, professional behavior, interpersonal skills with patients, and dealing with emergency situations. Only 30% of the critical incidents obtained from the faculty were related to criteria traditionally used to select and evaluate residents, such as knowledge and technical skills, while the remaining incidents were noncognitive in nature. The results of this study have implications for the evaluation and selection of residents and suggest that pediatric program directors and faculty must give attention to the means by which noncognitive skills are fostered in residents.

Attitude of Health Personnel↗
PubMed1988

Production of oxidative DNA damage during the metabolic activation of benzo[a]pyrene in human mammary epithelial cells correlates with cell killing.

We have studied the generation of reactive oxygen species during the metabolism of a carcinogen, benzo[a]pyrene, by human mammary epithelial cells. We have quantitated the production of one type of oxidative DNA damage, thymine glycols, by using a monoclonal antibody specific to this base modification. Thymine glycols were produced in DNA in a dose-dependent manner after exposure of human mammary epithelial cells to benzo[a]pyrene. The number of thymine glycols formed in the DNA was similar to that of 7,8-dihydroxy-9,10-epoxy-7,8,9,10-tetrahydrobenzo[a]pyrene covalently bound to the DNA. Exposure of cells to the carcinogen in the presence of superoxide dismutase, which reduces superoxide anions, inhibited the production of thymine glycols and increased cell survival but had little effect on adduct formation. At equitoxic doses, approximately equal to 10-fold more thymine glycols were formed after exposure to benzo[a]pyrene than to gamma-irradiation. Thymine glycols, produced by either agent, were efficiently removed from the DNA of the cells. Since thymine glycols represent only a portion of the oxidative damage possibly produced, our results indicate that the total amount of oxidative damage induced during the exposure of human mammary epithelial cells to benzo[a]pyrene greatly exceeds the amount produced by direct adduct formation and that this indirect damage plays an important role in the cytotoxicity of benzo[a]pyrene.

Benzo(a)pyrene↗
PubMed1988

Informed consent.

Explore the source record for details and available documents.

Acquired Immunodeficiency Syndrome↗
PubMed1987

Metabolism of 7,12-dimethylbenz[a]anthracene by mouse mammary cells in serum-free organ culture medium.

The murine mammary gland is a prime target organ for 7,12-dimethylbenz[a]anthracene, (DMBA)-induced carcinogenesis. We analyzed the metabolism of 3H-DMBA in a cell-free microsomal activation system derived from mouse mammary microsomes and in a whole mammary organs in culture. The in vitro microsomal activation system failed to show the more polar diol derivative of DMBA after HPLC. The metabolites obtained directly from the 3H-DMBA-treated whole mammary organs, however, revealed the presence of both the diol as well as the phenolic derivatives of DMBA. Analysis of the glands and the culture medium further showed that nearly 95% of the radioactivity added to the culture medium was associated with the adipose tissue and complete solubilization of the fat pad released substantial amounts of DMBA and its metabolites. It appears that a large portion of DMBA and its metabolites remain entrapped in the adipose tissue surrounding the parenchyma. Formic acid digestion of the gland releases the DMBA and the metabolites allowing their ethylacetate extraction, and HPLC characterization.

9,10-Dimethyl-1,2-benzanthracene↗
PubMed1987

Long-range genomic map of the Duchenne muscular dystrophy (DMD) gene: isolation and use of J66 (DXS268), a distal intragenic marker.

By cloning the endpoints of a DMD-associated deletion, we have "jumped" 1100 kb from pERT87-1 (DSX164) to a new locus designated J66 (DXS268), mapping distally within the Duchenne muscular dystrophy (DMD) gene. Both J66 and JBir are mapped by field-inversion gel electrophoresis and detect abnormal SfiI fragments in DMD patients and distal DMD-associated X; autosome translocations. Our long-range map extends the physical map of the DMD gene from 800 to 2000 kb (2 Mb) and increases the mapped portion of Xp21 to approximately 8 Mb. The position of the glycerol kinase gene and the adrenal hypoplasia locus are further confined to the region between J66 and the nearest distal probe L1-4. This region spans at least 1.5 Mb. The multiallelic J66 polymorphism has immediate application in the diagnosis of DMD and generally appears to be distal to DMD mutations.

Chromosome Deletion↗
PubMed1986

Isolation of a random cosmid clone, cX5, which defines a new polymorphic locus DXS148 near the locus for Duchenne muscular dystrophy.

We have isolated a random cosmid cX5 (DXS148), which maps into a small Xp21 deletion associated with Duchenne muscular dystrophy (DMD), chronic granulomatous disease (CGD), retinitis pigmentosa (RP) and McLeod syndrome, cX5 maps proximally outside several other deletions associated with DMD, glycerol kinase deficiency (GK) and adrenal hypoplasia (AHC). The following order of loci is proposed: centromere-OTC-cX5 (DXS148)-754 (DXS84)-PERT87 (DXS164)/DMD-telomere. A subclone cX5.7, isolated from this cosmid, identifies an MspI RFLP, with a minor allele frequency of 35%. This probe forms an important adjunct to the existing RFLPs for family studies in Duchenne muscular dystrophy.

Chromosome Deletion↗
PubMed1986

Legionella feeleii-associated pneumonia in humans.

Legionella feeleii has been implicated by serologic studies as the causative agent in an outbreak of Pontiac fever and has been recovered from an institutional water source. Pneumonia caused by this agent has not been described previously. The authors have isolated L. feeleii from two immunosuppressed patients with community-acquired pneumonia and from an institutional water source. One patient survived after treatment with erythromycin. The other patient was leukopenic and died of pneumonia. Isolates exhibited typical cultural and biochemical features of L. feeleii and reacted with L. feeleii serogroup 1 antiserum. L. feeleii serogroup 1 is now known to cause not only Pontiac fever but also pneumonia in humans.

Cross Infection↗
PubMed1986

Medical Communication Behavior System. An interactional analysis system for medical interactions.

The study assessed the psychometric properties of the Medical Communication Behavior System. This observation system records time spent by the physicians and patients on specific behaviors in the categories of informational, relational, and negative situation behaviors by using hand-held electronic devices. The study included observations of 101 genetic counseling sessions and also assessed the outcome measures of patient knowledge and satisfaction. In addition, 41 of the sessions were rated using the Roter Interactional Analysis System, and 20 additional control subjects completed the post-counseling information without being observed to examine the effects of recording the session. Results showed good interobserver reliability, and evidence of concurrent, construct, and predictive validity. No differences were found between the observed and unobserved groups of any of the outcome measures.

Behavior↗
PubMed1975

Prevention of pulmonary vascular changes of chronic alveolar hypoxia by inhibition of angiotensin I-converting enzyme in the rat.

To test the hypothesis that the renin-angiotensin system is involved in the development of the pulmonary vascular patholigic changes of chronic alveolar hypoxia, two groups of rats were exposed to 0.5 atm. for 21 days. One group received SQ 20,881 (2 mg. per kg.) every 8 hours subcutaneously and the second group received normal saline. A third group of rats was maintained at normobaria. Rats receiving SQ 20,881 had significantly less pulmonary arterial hypertrophy and right ventricular hypertrophy than hypobaric animals. SQ 20,881-treated rats showed a significant increase in adrenal weight but a marked reduction in the thickness of the zona glomerulosa, as compared with the other groups. Our findings indicate that angiotensin II is necessary in the development of the pulmonary vascular structural changes of chronic alveolar hypoxia.

Adrenal Glands↗