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Biomedical subjects

J Russell

Publications and source records attributed to J Russell.

At least 199 records · Page 11Linked to original sources
PubMed1993

Community patterns of psychiatric disorders after the Exxon Valdez oil spill.

OBJECTIVE: This study examined the relationship between exposure to the Exxon Valdez oil spill and subsequent cleanup efforts and the prevalence of generalized anxiety disorder, posttraumatic stress disorder (PTSD), and depressive symptoms in 13 Alaska communities. METHOD: A community survey of 599 men and women was conducted approximately 1 year after the spill occurred. Questions from the National Institute of Mental Health Diagnostic Interview Schedule were used to assess symptoms of generalized anxiety disorder and PTSD. The Center for Epidemiologic Studies Depression (CES-D) Scale was used to assess levels of depressive symptoms. RESULTS: The post-spill (i.e., 1-year) prevalence of generalized anxiety disorder and PTSD for the study communities with all degrees of exposure was 20.2% and 9.4%, respectively. The prevalence of respondents with CES-D Scale scores above 16 and 18 was 16.6% and 14.2%, respectively. When compared with the unexposed group, members of the high-exposure group were 3.6 times as likely to have generalized anxiety disorder, 2.9 times as likely to have PTSD, 1.8 times as likely to have a CES-D Scale score of 16 and above, and 2.1 times as likely to have a CES-D Scale score of 18 and above. Women exposed to this event were particularly vulnerable to these conditions, and Alaska Natives were particularly vulnerable to depressive symptoms after the oil spill. CONCLUSIONS: The results suggest that the oil spill's impact on the psychosocial environment was as significant as its impact on the physical environment. The Exxon Valdez experience suggests a number of implications for the mental health needs of disaster victims, particularly in primary care settings.

Accidents↗
PubMed1993

Interaction between calcium and 1,25-dihydroxyvitamin D3 in the regulation of preproparathyroid hormone and vitamin D receptor messenger ribonucleic acid in avian parathyroids.

Regulation of prepro-PTH and vitamin D receptor (VDR) mRNAs in the parathyroid glands was studied in chickens in vivo. The birds were raised to 21 days of age on a vitamin D-deficient diet with 1% calcium and 0.65% phosphorous. At the end of this period, the chicks exhibited marked hypocalcemia and enlarged parathyroid glands. In three separate trials, the birds were repleted for 6 days with vitamin D and different dietary calcium and phosphate concentrations, with 2 micrograms/kg 1,25-dihydroxyvitamin D3 [1,25-(OH)2D3] and different dietary calcium concentrations (0.5%, 1.0%, or 1.8%), or with 2 or 10 micrograms/kg 1,25-(OH)2D3 and 0.6% or 1.9% calcium or were kept vitamin D3 deficient and fed 0.5%, 1.0%, or 1.8% dietary calcium. Vitamin D treatment when combined with a high level of dietary calcium resulted in an increase in plasma calcium from 6 mg/dl to greater than 10 mg/dl, a decrease in PTH mRNA of 65%, and a 6- to 8-fold increase in VDR mRNA. In another experiment in which no vitamin D source was given and the diets contained increasing levels of dietary calcium, plasma calcium increased significantly (5.5 vs. 7 mg/dl), while PTH mRNA decreased by 40% and VDR mRNA increased by 60%. Neither parathyroid gland weight nor total RNA was significantly affected. When chicks were repleted with 1,25-(OH)2D3, the increase in plasma calcium and VDR mRNA and the decrease in PTH mRNA were considerably more pronounced than those in the absence of the vitamin D source. Furthermore, in the presence of the hormone, parathyroid weight and total RNA decreased significantly with increasing concentrations of dietary calcium. When the chicks were repleted, respectively, with the two levels of 1,25-(OH)2D3, a marked positive interaction was evident between the hormone and dietary calcium in affecting levels of PTH and VDR mRNA. These results suggest that both 1,25-(OH)2D3 and calcium participate in the regulation of PTH and VDR gene transcription in the avian parathyroid gland. Whereas the action of 1,25-(OH)2D3 requires a minimal level of dietary calcium, calcium affects PTH and VDR gene transcription even in the absence of any vitamin D source.

Animals↗
PubMed1993

Medical informatics vocabulary.

In order that medical informaticians can create Open Systems for health care, they need to have a common language. Efforts in the 1980s at the National Library of Medicine to create a Medical Informatics Vocabulary (MIVoc) have been useful for document indexing purposes, but need to be continued and extended. The Committee of European Normalization Technical Committee 251 has created a project team for MIVoc, and that team has used both automatic and manual methods and referenced many sources in producing a vocabulary that has support from numerous experts in Europe. MIVoc has both a glossary and a tree structure. The glossary has about 250 terms with detailed definitions that include various explanations and pointers. One critical pointer is the semantic link to other terms in MIVoc from a which a tree-structure is inferred. The success of MIVoc clearly depends on its being used, which in the long run depends also on the vocabulary being maintained.

Humans↗
PubMed1993

Platelet-activating factor promotes shear rate-dependent leukocyte adhesion in postcapillary venules.

Reductions in shear rate are generally associated with a recruitment of rolling and adherent leukocytes within the microcirculation. In this study, we determined if platelet-activating factor (PAF) affects shear rate-dependent leukocytes adhesion in cat mesenteric venules and whether the adhesion glycoproteins CD11/CD18 and ICAM-1 contribute to this process. Shear rate was varied in postcapillary venules (25-35 microns) by graded occlusion of the superior mesenteric artery. Vessel diameter, red blood cell velocity, leukocyte rolling velocity, and the number of rolling and adherent leukocytes were measured at each shear rate either in the presence or absence of PAF superfusion. PAF superfusion resulted in an increased number of adherent, but not rolling, leukocytes at basal and reduced venular shear rates. A monoclonal antibody (MAb) directed against CD11/CD18 prevented the PAF-induced recruitment of adherent leukocytes, while an ICAM-1 specific MAb had no effect. These results indicate that PAF increases shear rate-dependent leukocyte adhesion, presumably through activation and/or increased surface expression of CD11/CD18 on granulocytes.

Animals↗
PubMed1992

Comparison of Yuzpe regimen, danazol, and mifepristone (RU486) in oral postcoital contraception.

OBJECTIVE: To compare the effectiveness and acceptability of three regimens of postcoital contraception. DESIGN: Randomised group comparison of ethinyloestradiol 100 micrograms plus levonorgestrel 500 micrograms repeated after 12 hours (Yuzpe method); danazol 600 mg repeated after 12 hours; and mifepristone 600 mg single dose. SETTING: Community family planning clinic. SUBJECTS: 616 consecutive women with regular cycles aged 16 to 45 years. MAIN OUTCOME MEASURES: Number of pregnancies, incidence of side effects, and timing of next period. RESULTS: The raw pregnancy rates (with 95% confidence intervals) for the Yuzpe, danazol, and mifepristone groups were 2.62% (0.86% to 6.00%), 4.66% (2.15% to 8.67%), and 0% (0% to 1.87%) respectively. Overall, these rates differed significantly (chi 2 = 8.988, df = 2; p = 0.011). The differences between the mifepristone and Yuzpe groups and between the mifepristone and danazol groups were also significant. Side effects were more common and more severe in the Yuzpe group (133 women (70%)) than in either the danazol group (58 (30%)) or the mifepristone group (72 (37%)). The Yuzpe regimen tended to induce bleeding early but mifepristone prolonged the cycle. Three women bled more than seven days late in the Yuzpe group compared with 49 in the mifepristone group. CONCLUSIONS: Mifepristone was effective in reducing expected pregnancy rates and the Yuzpe method also had a clinical effect. Danazol had little or no effect. A further multicentre trial is needed.

Adolescent↗
PubMed1992

Synthesis and antiulcer activity of novel 5-(2-ethenyl substituted)-3(2H)-furanones.

In order to investigate new antiulcer agents, spizofurone 1 (AG-629) was fragmented and reassembled to generate 5-phenyl-2,2-dimethyl-3(2H)-furanone (bullatenone, 2). Because of the antiulcer activity of 2,5-phenyl-substituted 2,2-dimethyl-3(2H)-furanones (3-6) were made and shown to have poor activity. Insertion of an ethenyl link between the furanone and phenyl rings gave 5-(2-phenylethenyl)-2,2-dimethyl-3(2H)- furanone (7). This compound had better activity than 2. Compounds 8-41 were synthesized to evaluate the SAR in 5-(2-ethenyl substituted)-3(2H)-furanones. Electron-withdrawing substituents on the aromatic ring (8, 10, 19, and 20) gave 2-3-fold higher activity. Further increases in the activity were found when the phenyl ring was replaced by heterocyclic nuclei. Compounds that contained a thiophene (29), pyridine (24-26), or quinoline ring (32) had the best activity. Replacement of the methyl group on the furanone ring with a phenyl (34) or p-fluorophenyl (40) substituent in the 2-pyridine series gave compounds with activity that ranked with the best obtained in this study. The best compounds from the above SAR studies were evaluated in the ethanol-necrosis model for duration of cytoprotection action. Compounds 19, 24, and 29, which had the best duration of action, were tested with AG-629 in the acidified aspirin and indomethacin-induced lesion models. Only compound 24 had equivalent activity with AG-629 in both models.

Animals↗
PubMed1992

Ethnic differences in stress, coping, and depressive symptoms after the Exxon Valdez oil spill.

This study assessed levels of depressive symptomatology in a household probability sample of Alaskan Native (N = 188) and Euro-American (N = 371) residents of 13 communities in Alaska. Our objective was to examine ethnic differences in both the association between depressive symptomatology and exposure to the Exxon Valdez oil spill and subsequent cleanup efforts, and in the role of family support as a moderator of exposure to this technological disaster. Level of exposure was significantly associated with mean Center for Epidemiological Studies-Depression Scale scores in both Natives (p less than .05) and Euro-Americans (p less than .01). Both ethnic groups also reported significant declines in traditional relations with increasing levels of exposure (p less than .001). However, Natives had a significantly higher mean Exposure Index score than Euro-Americans and were more likely to report working on cleanup activities, damage to commercial fisheries, and effects of the spill on subsistence activities. Depressive symptomatology was associated with reported participation in cleanup activities and other forms of contact with the oil in Natives, and reported damage to commercial fisheries, use of affected areas, and residence in a community in geographic proximity to the spill in Euro-Americans. Perceived family support was not directly associated with depressive symptoms in either ethnic group, but did serve to buffer the effects of exposure on depressive symptoms in Euro-Americans. The results suggest that cultural differences play an important role in determining the psychosocial impacts of a technological disaster, particularly with respect to exposure, appraisal of an event as stressful, perceived family support as a moderator of stress, and expression of depressive symptomatology.

Adaptation, Psychological↗
PubMed1992

Leukotriene B4 mediates shear rate-dependent leukocyte adhesion in mesenteric venules.

Previous studies have demonstrated that low shear rates promote leukocyte adherence to microvascular endothelium in postcapillary venules. The objective of this study was to determine whether an accumulation of inflammatory mediators such as platelet activating factor and leukotriene B4 is responsible for shear rate-dependent leukocyte-endothelial cell adhesion. Postcapillary venules (25-39 microns in diameter) in cat mesentery were studied by intravital microscopy. Venular wall shear rate was varied over a wide range by graded occlusion of the mesenteric artery. Red blood cell velocity, vessel diameter, leukocyte rolling velocity, and the numbers of rolling and adherent leukocytes were measured at each shear rate. In one series of experiments, shear rate-dependent leukocyte adherence was monitored at different superfusion rates (1.0 and 2.5 ml/min). At the lower superfusion rate, the number of adherent leukocytes was significantly higher at any given shear rate when compared with results obtained at the higher superfusion rate. This suggests that reduced washout of inflammatory mediators contributes to shear rate-dependent leukocyte adhesion. Pretreatment with different platelet activating factor receptor antagonists (WEB 2086 or WEB 2170) had no effect on the number of adherent leukocytes normally observed at lower shear rates, suggesting that platelet activating factor does not play a major role in this process. However, shear rate-dependent leukocyte adhesion was largely prevented by pretreatment with either a leukotriene B4 receptor antagonist (SC-41930) or a leukotriene synthesis inhibitor (L663,536). The results of this study indicate that a reduced washout of leukotriene B4 is responsible for the enhanced leukocyte adherence that occurs at low venular wall shear rates.

Animals↗
PubMed1992

Isolation and expression of two novel Wnt/wingless gene homologues in Drosophila.

Wingless (wg), the Drosophila homologue of the mouse Wnt-1 proto-oncogene, is a segment polarity gene essential in each segment for normal Drosophila development. We here report the isolation of two novel Drosophila Wnt homologues, DWnt-2 and DWnt-3, and thus the existence of a Wnt/wingless gene family in Drosophila. DWnt-2 and DWnt-3 map to chromosome 2 position 45E and chromosome X position 17A/B, respectively. DWnt-2 and DWnt-3, like the other known Wnt genes, encode amino-terminal signal peptides suggesting that the gene products are secreted proteins. The putative translation product of DWnt-2 and the carboxy-terminal half of the deduced DWnt-3 product are both rich in conserved cysteine residues. In comparison with other Wnt gene products, mostly about 40 x 10(3) relative molecular mass, the DWnt-3 protein has an extended amino terminus and a long internal insert, and its predicted relative molecular mass is 113 x 10(3). The expression patterns of these two Wnt/wg homologues are dynamic during Drosophila embryogenesis. The distribution of DWnt-2 transcripts is predominantly segmented, with the additional presence of transcripts in the presumptive gonads. Transcripts of both DWnt-2 and DWnt-3 appear to be associated with limb primordia in the embryo and may therefore specify limb development. DWnt-3 is also expressed in mesodermal and neurogenic regions. The distribution of DWnt-3 transcripts in cells of the central nervous system (CNS) during Drosophila embryogenesis suggests that DWnt-3 could be involved in CNS development.

Amino Acid Sequence↗
PubMed1992

Kleine-Levin syndrome: a case report.

Kleine-Levin Syndrome is an unusual sleep disorder occurring predominantly, but not exclusively, in late adolescent males. A case is described which illustrates some of the difficulties in diagnosis and management.

Adolescent↗
PubMed1992

Is tardive anorexia a discrete diagnostic entity?

A study is described in which patients in three diagnostic groups were compared in an effort to delineate features of tardive anorexia (late onset anorexia nervosa). There were 18 patients in each diagnostic group. Patients with "classical" anorexia nervosa of less than 5 years duration were compared with patients older than 25 who had been chronically ill for more than 5 years and with those in whom the symptoms had begun de novo after the age of 25. Statistically significant differences were found to distinguish the third group as a distinct diagnostic entity. The association of loss precipitants and depressive symptoms has practical implications in the management of true anorexia tardive.

Adolescent↗
PubMed1992

Relationships of parathyroid hormone, parathyroid secretory protein, parathyroid hormone messenger RNA, parathyroid secretory protein mRNA, and replication in human parathyroid adenoma and secondary hyperplasia tissues and cultures.

BACKGROUND: The purpose of this study was to clarify the relationships of extractable and secreted parathyroid hormone (PTH) and parathyroid secretory protein (PSP) in human parathyroid tumors to PTH messenger RNA (mRNA), PSP mRNA, and cell replication. METHODS AND RESULTS: In tissue cultures of seven adenomas and five secondary hyperplasias, we found a direct correlation for secreted PTH versus PSP for both adenomas and secondary hyperplasias. Secreted PTH:PSP was elevated for adenomas (11:1) compared to that of secondary hyperplasias (2:1), and adenomas secreted significantly more PTH and PSP than did secondary hyperplasias. In extracts of eight adenomas and six secondary hyperplasias, the ratio of PTH:PSP was unexpectedly low (2:1) and similar for both adenomas and secondary hyperplasias. The ratio of extractable PTH mRNA:PSP mRNA was extremely low for both adenomas (1:7) and for secondary hyperplasias (1:5). Flow cytometry indicated that percent replication was inversely correlated with PTH mRNA and PSP mRNA. CONCLUSIONS: Increased PTH secretion by adenomas cannot be attributed to increased biosynthetic capacity because it is less than expected. Hypersecretion of PTH by adenomas and coincident marked reductions in PTH mRNA suggest either a defect in cytoplasmic storage of PTH or impairment of normal posttranslational degradation of PTH. As parathyroid tumor cells increase replication, PTH mRNA is reduced. Possible explanations for this include decreased PTH gene transcription or decreased mRNA half-life.

Adenoma↗
PubMed1992

The effect of transfection with the oncogenes H-ras and c-myc on the radiosensitivity of a mink epithelial cell line.

We have investigated the effect of transfection with the oncogenes c-myc and H-ras on cellular radiosensitivity. We obtained a mink lung epithelial line, Mv1Lu (ATCC CCL-64), and two sublines which had been transformed by transfection with c-myc and mutated (T24) H-ras 1. The cell survival parameters do not differ significantly between the three lines. These parameters were, for the parent line: D0 = 1.95 Gy, n = 2.0; for the c-myc transfected line: D0 = 2.10 Gy, n = 2.33; and for the H-ras transfected line: D0 = 2.40 Gy, n = 1.77. Although the terminal slope of the survival curve of the cells of the parent line is slightly steeper than that for the cells of either of the transfected lines, the differences are not significant. Nor is there any difference between the cell lines at the clinically relevant dose of 2 Gy. We conclude that neither activated H-ras nor c-myc oncogenes alter the radiosensitivity of the Mv1Lu line.

Animals↗
PubMed1991

Using critical learning incidents in nurse education.

This paper describes an attempt to provide a learning environment conducive to the development of conceptual skills in critical exploration and problem solving. This is achieved by using a method of reflecting on and about critical incidents encountered by student nurses during their nursing practice. It is argued that students need help in making links between theory and practice and the article relates how this may be achieved in workshops using mainly experiential techniques. The authors conclude that the use of such a strategy can make a valuable contribution to nurse education, enabling students to look at situations from multiple perspectives and heightening awareness of the complex skills involved in nursing.

Clinical Competence↗
PubMed1991

Effects of ranitidine, given t.d.s., on intragastric and oesophageal pH in patients with gastrooesophageal reflux.

The purpose of this study was to determine the effects of 150 mg ranitidine, 300 mg ranitidine or placebo, administered every 8 h, on gastro-oesophageal pH and heartburn parameters in reflux patients. Twelve symptomatic reflux patients received each of the three treatments in a randomized, double-blind, crossover fashion. Intragastric and oesophageal pH were monitored continuously for a 24 h period. Meals were standardized, consumed at set times and patients were allowed to recline and sleep from 23.00 hours until 06.00 hours only. The gastric record was analysed for the percentage of time that the pH was greater than or equal to 4. The oesophageal record was analysed for acid contact time (percentage time (%) pH less than or equal to 4.0) and reflux episode frequency. Finally, patients recorded each new episode of heartburn and graded daytime heartburn severity at the end of each hour. Ranitidine increased the median (%) time that the intragastric pH remained at or above 4, from 4.5 (placebo) to 33.9% (150 mg dose) and 33.3% (300 mg dose). Ranitidine dose-dependently reduced the median 24-hour oesophageal acid contact time from 13.3% (placebo) to 6.8% (150 mg dose) and 2.5% (300 mg dose). The 300 mg dose significantly reduced daytime heartburn episode frequency and severity while the 150 mg dose reduced heartburn severity only. We conclude that 150 and 300 mg doses of ranitidine administered every 8 h have major, sometimes dose-dependent effects on the objective parameters and symptoms of gastro-oesophageal reflux.

Adult↗