Search PubMed⌕ Search

Biomedical subjects

J Russell

Publications and source records attributed to J Russell.

At least 217 records · Page 12Linked to original sources
PubMed1991

IQ similarity in monozygotic and dizygotic twin children: effects of the same versus different examiners: a research note.

The Wechsler Intelligence Scale for Children--Revised was administered to two independently identified samples of monozygotic (MZ) and dizygotic (DZ) twin children. Co-twins in the first sample were tested by the same examiner, while co-twins in the second sample were tested by different examiners. IQ intraclass correlations were similar for the two MZ twin samples (.84 and .88), and identical for the two DZ twin samples (.54). The implications of this analysis are discussed with reference to twin study methodology, research on IQ similarity and replication of child development research.

Child↗
PubMed1991

Retention of nonlinear viral DNA during herpes simplex virus latency in vitro.

We investigated the state of the herpes simplex virus type 2 (HSV-2) genome during latency in vitro. Latent DNA was present in the cell nucleus in a nonlinear configuration. The joint fragment was represented at approximately double the molar concentration of fragments from unique regions, indicating that genome termini had fused. The HSV-2 genome copy number was estimated to be between 1.5 and 8, with a mean value of 4.5 per latently infected cell. Nonlinear HSV DNA can therefore exist during latency both in vivo and in vitro.

DNA, Viral↗
PubMed1991

The modulation of the expression of IL-6 and its receptor in human osteoblasts in vitro.

Interleukin 6 (IL-6) probably plays a central role in the acute phase response and in haemopoiesis and may be involved in the control of bone turnover. We have studied the release of IL-6 from human trabecular bone cells treated with a variety of stimuli using a specific bioassay. In serum free medium, unstimulated human osteoblast-like cells produced IL-6 in the range of 1000-2050 pg/ml/24 h. Recombinant human interleukin 1 (IL-1 alpha) (10(-13)-10(-11) M), tumor necrosis factor alpha (TNF alpha) (10(-9)-10(-7) M) and lipopolysaccharide (5-500 ng/ml) all stimulated release of IL-6 from human bone cells. Maximal levels of 17,000 pg/ml were observed using the highest concentration of IL-1. 1,25(OH)2D3 and PTH did not stimulate IL-6 release. Using a specific sheep antihuman IL-6 antibody, all IL-6 activity could be neutralized. In parallel studies, ROS 17/2.8 rat osteosarcoma cells released around 50 pg/ml of IL-6 under basal conditions which were increased to a maximum of 900 pg/ml by treatment with PTH (10(-9) M). The cytokines were less effective and 1,25(OH)2D3 again had no effect. Modulation of expression of IL-6 mRNA in human osteoblast cells was examined using a human complementary deoxyribonucleic acid probe. The mRNA was constitutively expressed, and IL-1 (10(-11) M) and TNF (10(-7) M) induced further mRNA expression within 2 h, which was sustained over 24 h. 1,25(OH)2D3 (10(-7) M), IL-6 (2000 pg/ml), and PTH (10(-9) M) exerted no effects at any time point. Dexamethasone (10(-6) M) suppressed both basal and IL-1- and TNF-induced IL-6 mRNA expression. IL-6 receptor mRNA was constitutively expressed but was not regulated by any of the above agents. It is clear that rodent and human osteoblasts differ in their production of IL-6 and its modulation. These data support the hypothesis that IL-6 is produced locally in human bone by osteoblasts under the direction of other cytokines. This could have implications in bone remodeling, haemopoiesis, and systemic responses to local injury.

Blotting, Northern↗
PubMed1991

Representativeness of deaths identified through the injury-at-work item on the death certificate: implications for surveillance.

BACKGROUND: This research investigated the accuracy of the injury-at-work item on the death certificate for surveillance of occupational injury deaths in Oklahoma during 1985 and 1986. METHODS: Representativeness of occupational injury deaths identified by death certificates was assessed by comparing these deaths with all occupational injury deaths identified through death certificates, workers' compensation reports, medical examiner reports, and OSHA records for categories of occupation, industry, and external causes of death. RESULTS: Certain external causes of death (e.g., motor vehicle traffic deaths) and certain occupations (e.g., farming) and industries (agriculture and services) are more often underidentified through death certificates. CONCLUSIONS: The findings of this study support Baker's observation that no single data source contains all deaths or all the data elements necessary to describe occupational injury deaths. Data sources may be combined to improve representativeness through more complete case ascertainment.

Accidents, Occupational↗
PubMed1991

Vasoactive intestinal polypeptide-, neurotensin-, substance P-, gastrin-releasing peptide-, calcitonin-, calcitonin gene related peptide-, and somatostatin-like immunoreactivities in human parathyroid glands.

We have found vasoactive intestinal polypeptide (VIP)-, neurotensin-, substance P-, gastrin-releasing peptide-, calcitonin-, calcitonin gene related peptide (CGRP-2)-, and somatostatin-like immunoreactivities in extracts of sporadic human parathyroid adenomas (n = 18). The content of CGRP-2, substance P, and somatostatin in adenomas correlated directly with that of parathyroid hormone. In addition, concentrations of VIP versus substance P and somatostatin versus CGRP-2 in adenomas were directly correlated. Neuropeptide content of parathyroid hyperplasias differed from that of adenomas. VIP was detected in only one of seven parathyroid hyperplasias, and neurotensin was undetectable (0/7), whereas substance P was present in six of seven cases and GRP in five of seven hyperplasias. In hyperplasias, content of substance P correlated directly with that of gastrin-releasing peptide. Peroxidase immunohistochemistry localized VIP-like immunoreactivity to 20% to 50% of both chief and oxyphilic cells and rare clear cells and capillary endothelium in 11 of 12 adenomas studied. Focal staining was present in glandular epithelium of the rim of adjacent normal parathyroid tissue and in two of three normal parathyroid glands removed with thyroid goiters. This staining was both cytoplasmic and apical membrane. By contrast, in adenomas, neurotensin- and substance P-like positivities were confined to scattered (5% to 10%) oxyphilic cells. Cytoplasmic positivity for parathyroid hormone, noted in 30% to 70% of cells in serial sections, confirmed that these tissues were indeed parathyroid glands.

Adenoma↗
PubMed1990

Regulation by calcium and 1,25-(OH)2D3 of cell proliferation and function of bovine parathyroid cells in culture.

The effects of high calcium and 1,25-(OH)2D3 on parathyroid cell growth, PTH secretion, and steady-state levels of pre-proPTH mRNA in proliferating bovine parathyroid cells were examined. Cells were established in primary tissue culture and then tested in passages 2 and 5. Cell proliferation was suppressed by 10(-9)-10(-7) M 1,25-(OH)2D3 but not by high calcium (2.5 mM). Cells at passages 2 and 5 were grown to subconfluence and then exposed for 72 h to 2.5 mM calcium or 10(-7) M 1,25-(OH)2D3. Pre-proPTH mRNA was decreased to approximately 50% of control by 2.5 mM calcium compared with 0.3 and 1.0 mM calcium. PTH secretion, as tested by low calcium stimulation for 1 h at the end of 72 h incubation, was inhibited by 50% in cells that had been exposed to high calcium compared with control. Incubation with 10(-7) M 1,25-(OH)2D3 caused a decrease in the levels of pre-proPTH mRNA and PTH release to 50% of control at 72 h. These results suggest that cultured bovine parathyroid cells, at least in early passages, have responses to high calcium and 1,25-(OH)2D3 similar to those in primary nonproliferating cultures studied earlier and that 1,25-(OH)2D3 inhibits the proliferation of parathyroid cells in a dose-responsive fashion.

Animals↗
PubMed1990

The role of symmetrical and asymmetrical social conflict in cognitive change.

We asked whether dyads consisting of nonconservers of liquid would be more likely than solo controls to change to a conservation answer when each child gave symmetrically conflicting answers from different perspectives ("more" versus "less" from different viewpoints). We also asked whether nonconservers are more likely than conservers to abandon their answers in conserver + nonconserver dyads. In order to stimulate the perspectival conflicts in the nonconserver + nonconserver dyads, the partners experienced artificial displays in which the two possible answers were afforded by different views of the apparatus. We found no evidence that social conflict of the kind engineered in the nonconserver + nonconserver dyads stimulates cognitive change. Our evidence that nonconservers tend to adopt the conservation answer of their partners was less strong than that collected in previous studies, but this may have been due to the fact that, contrary to previous studies, the children's social dominance relations were affecting the outcome. We concluded that the ineffectiveness of symmetrical social conflict is consistent with Piaget's conception of nonconservers as children insensitive to the perspective-relative nature of their judgments.

Child↗
PubMed1990

Death related themes in anorexia nervosa: a practical exploration.

On the basis of an extensive literature review, Jackson and Davidson (1986) suggested that the theme of death may constitute an integral part of the psychodynamic aetiology of anorexia nervosa. This paper describes an attempt to explore this contention using a structured questionnaire in a group of adolescent patients to examine experiences, concepts of and attitudes concerning death. Comparison of the responses of this group with those of age matched school student controls and recovered patients revealed qualitative and quantitative differences which lent some support to the hypothesis. It is concluded that death related themes are of significance in the understanding and management of this illness.

Adolescent↗
PubMed1990

Cloning of the listeriolysin O gene and development of specific gene probes for Listeria monocytogenes.

A clone containing 3.1 kb of Listeria DNA was selected from a gene library of Listeria monocytogenes Scott A strain. The Escherichia coli clone produced hemolysin on sheep blood agar and in sonicated extracts but very little in the culture supernatant. This 3.1-kb DNA fragment and a 650-bp HindIII fragment located within the listeriolysin gene were used as probes in a colony hybridization assay. Both probes were specific for L. monocytogenes and did not hybridize with any other Listeria strains at high stringency. Two synthetic probes, one from the 650-bp HindIII fragment and one from the carboxy-terminal region of the protein, were also specific for L. monocytogenes.

Bacterial Proteins↗
PubMed1990

Role of platelet-activating factor in ischemia/reperfusion-induced leukocyte adherence.

The objective of this study was to determine whether platelet-activating factor (PAF) mediates the leukocyte-endothelial cell interactions elicited by ischemia/reperfusion. The rates of adherence and extravasation of leukocytes were monitored in cat mesenteric venules subjected to 60 min of ischemia (blood flow reduced to 20% of control) followed by 60 min of reperfusion. Leukocyte rolling velocity, red blood cell velocity, and vessel diameter were also measured. The experiments were performed in control (untreated) animals and in animals pretreated with one of two PAF receptor antagonists, i.e., BN 52021 or WEB 2086. The responses of venular blood flow, wall shear rate, and vessel diameter did not differ between the three groups. In the control group, 1 h of ischemia was associated with significant adherence and extravasation of leukocytes, with reperfusion greatly enhancing these responses. The rates of leukocyte adherence and extravasation during reperfusion were greatly attenuated by both PAF antagonists. Furthermore, the proportion of adherent leukocytes that ultimately extravasate during reperfusion was markedly reduced by WEB 2086. These results suggest that PAF plays an important role in mediating the adhesive interaction between circulating leukocytes and microvascular endothelium induced by ischemia/reperfusion and that the phospholipid promotes the leukocyte extravasation associated with ischemia/reperfusion.

Animals↗
PubMed1990

1,25-Dihydroxyvitamin D3 has opposite effects on the expression of parathyroid secretory protein and parathyroid hormone genes.

Previous studies have shown that 1,25-dihydroxyvitamin D3 [1,25-(OH)2D3] decreases levels of mRNA for prepro-PTH as well as PTH secretion after chronic exposure (24-48 h) of parathyroid cells in tissue culture. We have now extended these studies to determine the effects of the vitamin D3 metabolite on parathyroid secretory protein (PSP) gene expression. Primary cultures of bovine parathyroid cells were incubated with 10(-8) M 1,25-(OH)2D3 for periods of time ranging from 24-72 h. As observed in earlier experiments, prepro-PTH mRNA decreased to less than 50% of the control value after 72 h. In marked contrast, PSP mRNA showed a 2.5-fold increase by 24 h and greater than 7-fold stimulation by 72 h. In the same studies, PTH secretion was suppressed (to 60% of control), while PSP secretion was increased by 40% over control values. Exposure to high (2.5 mM) or low (0.5 mM) calcium had no effect on PSP mRNA, even though low calcium stimulated the secretion of PSP while high calcium suppressed secretion. These studies showed that 1,25-(OH)2D3 has opposite effects on the gene expression of PSP and PTH in bovine parathyroid cells in tissue culture.

Animals↗
PubMed1990

Disabilities in leprosy patients ascertained in a total population survey in Karonga District, northern Malaŵi.

This paper describes the pattern of disability among 1654 leprosy patients ascertained between 1973 and 1987 in Karonga District, Northern Malaŵi. Approximately 20% of patients identified prior to 1980 had some disability at registration, but this percentage fell to approximately 10% with the introduction of total population surveys in the Lepra Evaluation Project. The proportion of patients with disabilities at registration increased with age, was higher among males than females, was higher among borderline and lepromatous than tuberculoid patients, and was higher for passively than for actively detected patients. The risk of developing disabilities among patients without any disabilities at registration was approximately 5 per 1000 person years, and appeared to be slightly higher after the completion of treatment than during treatment.

Adolescent↗
PubMed1990

Esophageal acid contact time and heartburn in acute treatment with ranitidine and metoclopramide.

Ranitidine and metoclopramide were compared for their ability to reduce esophageal acid contact time and heartburn. Twelve patients with histories of heartburn received ranitidine 150 mg bid, metoclopramide 10 mg qid, and placebo (ranitidine-matched) bid in a randomized, open-label, crossover fashion. Esophageal pH was monitored with an antimony electrode and portable recording unit for 24 h under strictly controlled laboratory conditions. Ranitidine significantly (p less than or equal to 0.05) reduced 24-h acid contact time from 11.6% to 6.4%. Reflux episode frequency was also significantly (p less than or equal to 0.05) reduced from 82 to 45 episodes per day and from 12 to 2 episodes at night. In contrast, metoclopramide did not reduce 24-h acid contact time or daytime reflux episode frequency, although nighttime episode frequency was significantly (p less than or equal to 0.05) decreased. Only ranitidine significantly reduced heartburn frequency and severity. We conclude that acute treatment with ranitidine, but not metoclopramide, significantly reduces esophageal acid contact time, reflux episode frequency, and heartburn frequency and severity in patients with gastroesophageal reflux.

Adult↗
PubMed1990

Relief for Romania.

Explore the source record for details and available documents.

Acquired Immunodeficiency Syndrome↗
PubMed1989

The elimination of cross-infection in dental practice--a 5-year follow-up.

A survey in 1983 showed that 16% of general dental practitioners in the Lothian Region wore operating gloves when treating patients; 9% wore them continually and 7% only when performing dento-alveolar surgery. Twelve per cent replied that they would not consider wearing operating gloves and 72% stated that they might consider their use. A similar survey has now been completed 5 years later, involving practitioners in the Lothian and Borders regions. This shows that 163 (97%) of the 168 practitioners who replied now wear operating gloves; 51% restrict their use to the treatment of 'potentially infectious patients' and dento-alveolar surgery; 46% wear them continually. The main objections given to wearing gloves continually were loss of tactile sensation (67%) and cost (13%). The most difficult task to perform wearing gloves was root canal therapy (56%). The majority of practitioners (84%) believed that gloves reduced the dangers of cross-infection. The methods stated to be available for instrument sterilisation in 99.5% of practices were acceptable. This paper proposes that to eliminate cross-infection and protect the dental practitioner, operating gloves should be worn when treating all patients.

Attitude to Health↗
PubMed1989

Expression and regulation of erythrocyte auto-antibodies in mice following immunization with rat erythrocytes.

Mice immunized with intact rat red blood cells (RBC) developed serum auto-antibodies (some of which were mouse specific) to the RBC membrane components spectrin and antigens of 100 and 81 kDa as shown by Western blotting and enzyme-linked immunosorbent assay as well as RBC surface-bound autoantibodies detected by the Coombs' test. In order to discover whether these autoantibodies were induced and controlled in similar or different ways, mice were challenged with a variety of rat and mouse RBC preparations. In addition, the ability of recipients given spleen cells from the above donors to generate autoantibody responses to intact rat RBC was measured. It was found that all the autoantibodies were induced in mice challenged with rat RBC ghosts but none following immunization with butanol-extracted rat RBC ghosts or intact mouse RBC. By contrast, mice injected with mouse RBC ghosts made autoantibodies to spectrin and to the 100-kDa band. Spleen cells from mice primed with intact rat RBC, rat RBC ghosts or butanol-extracted rat RBC ghosts curtailed Coombs' autoantibody production of recipient mice challenged with intact rat RBC. Serum from recipients of spleen cells primed with intact rat RBC or the butanol extract generally failed to react with rat or mouse spectrin or with the 81-kDa band, although antibody was detected to the rat 100-kDa band. Recipients of rat RBC ghost-primed spleen cells produced antibody to rat and mouse spectrin and to rat 100-kDa band but not to mouse 100-kDa or rat or mouse 81-kDa bands. Occasionally, suppression of antibody to the rat-specific 38-kDa band was observed in recipients of intact rat RBC-primed spleen cells. It is therefore suggested that regulation of cross-reactive and mouse-specific autoantibodies as well as rat-specific antibodies occurs in an independent, determinant-specific manner.

Animals↗