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Biomedical subjects

J Dunn

Publications and source records attributed to J Dunn.

At least 181 records · Page 10Linked to original sources
PubMed1989

Psychiatric intervention in the community hospital emergency room.

Community hospitals are seeing an increasing number of patients with psychiatric problems in their emergency rooms (ERs). Nurse administrators can decrease extended ER psychiatric patient waiting, and the disruptive behavior which may result, by using an interdepartmental team of ER and mental health unit RNs able to perform psychiatric assessments. This can be accomplished through a competency program based on collaboration.

Emergency Service, Hospital↗
PubMed1988

Sibling influences on childhood development.

To summarize the main points concerning sibling influence: 1. That siblings play a causal role in the development of aggressive behavior, in children's style of conflict behavior and in cooperative fantasy play is strongly suggested by recent research. 2. Marked problems in the sibling relationship are indicative of other problems, but a causal role for siblings is not established, other than for aggressive behavior. 3. Family factors are closely involved in the quality of sibling relationships--and thus in sibling influence, namely differential parental behavior, and the emotional climate of the family. That is, it is important not to consider the sibling relationship in isolation from other family relationships. 4. Studies of families under stress indicate heightened importance of these family factors. 5. It is likely, but not yet established, that later-born siblings are influenced by first-born in socio-cognitive development and gender identity. 6. Finally it should be noted that an important theme in current research on siblings is a concern with the question of why siblings develop to be so different from one another. It has been shown that the major source of environmental influence on the development of individual differences is within-family rather than between-family differences in experience (Plomin & Daniels, 1987). The different experiences each sibling may have within their relationship is one potential source of such differential environmental influence. Thus documenting the influence of siblings upon each other takes on added significance: By clarifying the extent and nature of this influence we will gain not only useful clinical information but illumination on a developmental principle of very general significance.

Aggression↗
PubMed1988

Infrequent genomic rearrangement and normal expression of the putative RB1 gene in retinoblastoma tumors.

Retinoblastoma (RB) tumors develop when both alleles of a gene (RB1) are mutated and unable to function normally. Recently, Friend et al. [S. H. Friend, R. Bernards, S. Rogelj, R. A. Weinberg, J. M. Rapaport, D. M. Albert, and T. P. Dryja, Nature (London) 32:643-646, 1986] reported the cloning of a gene, 4.7R, with some properties expected for the RB1 gene, namely, a high frequency (30%) of genomic rearrangements in tumors and absence of message in all RB tumors examined. To extend the characterization of this gene, we used 4.7R probes to search for genomic rearrangements of DNA and to study the expression of the 4.7R gene in RB tumors, osteosarcoma (OS) tumors arising in RB patients, and other normal and malignant tissues. In 34 previously unreported RB and OS tumors arising in RB patients, we observed only four (12%) with genomic abnormalities. Transcripts of 4.7R were present in 12 of 17 RB tumors, 2 of 2 OS tumors, and all non-RB tumors and normal tissues tested. We were unable to confirm the high frequency of truncated messages of 4.7R in RB tumors reported by Lee et al. (W. H. Lee, R. Bookstein, F. Hong, L. J. Young, J. Y. Shaw, and E. Y. Lee, Science 235:1394-1399, 1987) and Fung et al. (Y. K. Fung, A. L. Murphree, A. Tang, J. Qian, S. H. Hinrichs, and W. F. Benedict, Science 236:1657-1661, 1987) but did confirm the presence of a truncated transcript in the RB cell line Y79. Of the RB and RB-related OS tumors which appeared normal on Southern blots, 2 of 26 or 12% had abnormal transcripts, giving a combined frequency of 22% abnormalities in the 4.7R gene detectable by Southern and Northern (RNA) blot analyses.

Gene Expression Regulation↗
PubMed1988

Screening for HIV.

Explore the source record for details and available documents.

Acquired Immunodeficiency Syndrome↗
PubMed1988

Long-term effects of a gonadotrophin-releasing hormone agonist ([D-Ser(But)6]GnRH(1-9)nonapeptide-ethylamide) on gonadotrophin secretion from human pituitary gonadotroph cell adenomas in vitro.

We have studied the effects of TRH and native gonadotrophin-releasing hormone (GnRH), and of a GnRH agonist (Buserelin; [D-Ser(But )6]GnRH(1-9) nonapeptide-ethylamide), on LH, FSH, alpha subunit and LH-beta subunit secretion from three human gonadotrophin-secreting pituitary adenomas in dispersed cell culture. During a 24 h study, treatment with 276 nmol TRH/l resulted in a significant (P less than 0.05) stimulated release of FSH and alpha subunit from all three adenomas, and LH from the two adenomas secreting detectable concentrations of this glycoprotein; treatment with 85 nmol GnRH/l significantly (P less than 0.05) stimulated the release of alpha subunit from all three, but FSH from only two and LH from only one adenoma. During a long-term 28-day study, basal FSH and alpha subunit concentrations were maintained, but secretion of LH, and LH-beta (detectable from one tumour only), declined with time from two of the three adenomas. Addition of Buserelin to the cultures resulted in the continuous (P less than 0.05) stimulation of alpha subunit secretion from all three adenomas, and of LH and FSH from two, whilst a transient stimulatory effect on LH and FSH secretion was seen from a third adenoma, with subsequent secretion rates declining towards control values. These data show that human gonadotrophin-secreting adenomas demonstrate variable stimulatory responses to hypothalamic TRH and GnRH, and that during chronic treatment with a GnRH agonist the anticipated desensitizing effect of the drug was not observed in two out of the three adenomas studied. The mechanisms for this is not clear, but such drugs are unlikely to be of therapeutic value in the management of gonadotrophin-secreting tumours. The data also suggest that GnRH and GnRH agonists have a differential effect on the in-vitro release of intact gonadotrophins and the common alpha subunit.

Adenoma↗
PubMed1988

An unusual oncocytic renal tumor with sarcomatoid foci and osteogenic differentiation.

A 67-year-old man with abdominal pain had a large neoplasm of the upper pole of the right kidney. The tumor was predominantly soft and brown but had one focus that was of bony consistency. On microscopic examination most of the tumor had the typical appearance of an oncocytoma, but rare papillary and sarcomatoid foci were identified, and there was focal metaplastic bone. Ultrastructural examination confirmed the oncocytic nature of most of the neoplasm. This case is further evidence that some predominantly oncocytic renal neoplasms have small foci that are incompatible with the diagnosis of oncocytoma.

Adenoma↗
PubMed1987

Reduction in S100 protein beta subunit mRNA in C6 rat glioma cells following treatment with anti-microtubular drugs.

S100 protein is a calcium-binding protein found in vertebrate nervous tissue. Synthesis of S100 protein in the rat glioma cell line, C6, is inhibited by the addition of anti-microtubular drugs. We have cloned a cDNA for the beta subunit of S100 protein from rat brain in a lambda gt 11 expression vector and used this cDNA to measure the amounts of S100 beta subunit mRNA in C6 cells after treatment with anti-microtubular drugs. Levels of alpha-tubulin and beta-actin mRNAs were also measured. All measurements were performed using RNA-RNA hybridization techniques at high stringency with rat mRNA-specific probes. After 24 h of treatment, the S100 beta subunit mRNA was reduced to levels of 25% by colchicine and 32% by vinblastine when compared to untreated controls. In contrast, the levels of tubulin and actin mRNAs were only slightly changed by these treatments. These studies demonstrate that disruption of the microtubular cytoskeleton causes a specific reduction in the level of S100 protein mRNA in C6 cells.

Amino Acid Sequence↗
PubMed1987

Situational factors and behavioral self-predictions in the identification of clients at high risk to drop out of psychotherapy.

Two hundred and eight adults who requested outpatient treatment at a community mental health center were asked to complete brief questionnaires immediately prior to and after their first therapy session. Questionnaires contained items that pertained to self-predicted length of stay in psychotherapy, situational barriers to regular attendance, and past behavior in similar situations (e.g., appointment-keeping with other health care professionals). Therapists also were asked to make predictions with regard to client length of stay. Questionnaire data were analyzed via a series of double cross-validated multiple regression and discriminant function equations, and results indicated that client and therapist predictions of length of stay in therapy were the most stable and consistent correlates of attendance behavior.

Adult↗
PubMed1987

Assessing the preventability of emergency hospital admissions. A method for evaluating the quality of medical care in a primary care facility.

The quality of primary medical care was assessed by studying the events leading to 686 emergency admissions of patients from our hospital-based primary care practice. Independent physician reviewers determined that 59 (9 percent) of the admissions were potentially preventable; 40 were due to iatrogenic factors including inadequate follow-up and adverse drug reactions, 12 were due to lack of patient compliance, and seven were due to both iatrogenesis and noncompliance. Adverse drug reactions were the most common cause of iatrogenesis, and warfarin was the drug that most commonly caused an adverse reaction. Inadequate follow-up of abnormal physical findings, symptoms, and laboratory test results was also important. Patients with preventable admissions had more medical diagnoses (4.9 versus 4.1, p less than 0.01), were prescribed more medications (4.5 versus 3.7, p less than 0.01), and were older (66.5 years versus 60.2 years, p less than 0.01) than patients whose admissions were not preventable. It is concluded that a small percentage of emergency hospitalizations may be preventable and that systematic review of emergency hospitalizations may provide a means of measuring the quality of primary medical care.

Adult↗
PubMed1987

Controlled-release formulations of propranolol and verapamil.

The in vitro and clinical behavior of new controlled-release formulations of propranolol and verapamil are reviewed. In vitro dissolution studies have proved to be of little value in determining the clinical activity of these new dosage forms. There is a difference between the blood levels found with the new formulations and those of the reference products. The once-daily verapamil product was evaluated in black hypertensive patients with promising results and suggests that this dosage form of verapamil may be successful as monotherapy for treating this patient population.

Animals↗
PubMed1987

Temperature acclimation and metabolism in ectotherms with particular reference to teleost fish.

As body temperature decreases, changes in the physical chemistry of the cell produce a reduction in metabolic activity. In temperate fish, cold water temperatures either lead to dormancy or else trigger a range of homeostatic responses which serve to offset the passive effects of reduced temperature. Compensatory adjustments to temperature occur with time courses ranging from less than a second to more than a month. Although swimming performance may increase with cold-acclimation, active metabolic rate remains significantly below that for warm-acclimated fish. Compensatory and dormancy responses are not mutually exclusive and sometimes occur in the same species depending on the temperature. Cold-acclimation results in significant increases in the density of mitochondria and capillaries in skeletal muscle. This serves to reduce diffusion distances and increase the capacity for aerobic ATP production relative to fish acutely exposed to low temperature. There is evidence that cold acclimation has differential effects on the synthesis and degradation rates of mitochondrial proteins leading to a net increase in their concentration. In contrast, the activities of enzymes associated with glycolysis and phosphocreatine hydrolysis show no consistent changes with thermal acclimation suggesting that flux through these pathways is modulated by factors other than enzyme concentration. Higher mitochondrial densities have also been reported for the liver, brain and gill tissue of cold compared with warm acclimated fish. In spite of their increased concentration, the activities of aerobic enzymes remain much lower at cold than warm temperatures. Acclimation temperature affects hepatosomatic index, the concentration of energy reserves, and the relative importance of glucose and fatty acid catabolism in liver. The fraction of glucose oxidized by the hexose monophosphate shunt (HMPS) pathway also increases with cold acclimation in some species. It is likely that many of the changes in liver metabolism with temperature acclimation reflect associated changes in feeding behaviour and/or diet, and other energetic demands (e.g. gametogenesis). Possible mechanisms underlying alterations in pathway utilization with temperature acclimation are discussed. They include changes in factors influencing enzyme structure and activity (e.g. pH, substrate/modulator concentrations, phosphorylation state, membrane composition), and effects of temperature on gene expression.

Adaptation, Physiological↗
PubMed1987

Central venous dialysis access: experience with a dual-lumen, silicone rubber catheter.

The central venous dialysis catheter has gained wide acceptance for short-term hemodialysis with the realization of the need to spare peripheral extremity vessels for the creation of more durable internal arteriovenous fistulas. The Hemocath (Quinton Instrument Co., Seattle, Wash.), a soft, silicone rubber, double-lumen central venous dialysis catheter, was introduced as a permanent access device in 1984. A prospective evaluation of 53 catheters placed in 51 patients over a 9-month period is presented. Forty-nine catheters were placed for temporary access and four were placed for permanent access. All 53 catheters were discontinued after functioning an average of 63.9 days (range, 5 to 324 days). No major complications occurred during insertion or on dialysis. One catheter fragmented during removal and was retrieved in the operating room. Infection led to the removal of 17 catheters (34.7%). Thrombosis occurred in 11 catheters and was the cause of removal in two (4.1%). Excluding the two catheters that functioned at the time of the patient's deaths and those placed for permanent access, 91.5% of the catheters performed successfully as temporary accesses devices until permanent access sites were available for use. The catheter provided reliable, relatively safe, and easily maintained central venous access for hemodialysis.

Adult↗
PubMed1986

Female androgenic alopecia. The 3 alpha,17 beta-androstanediol glucuronide/sex hormone binding globulin ratio as a possible marker for female pattern baldness.

Twenty-five women fulfilling the criteria for female alopecia, of either the male pattern baldness type or female pattern baldness type, were evaluated for hormone markers to delineate the clinical baldness patterns. Women with a marked increase in the 3 alpha,17 beta-androstanediol glucuronide/sex hormone binding globulin ratio and low serum sex hormone binding globulin were noted to have female pattern baldness. This pattern of baldness may represent hair loss from the influence of minimal androgen excess on genetically sensitive hair bulbs in the absence of other signs of maximal androgen excess, including hirsutism, acne, or virilism.

Adult↗