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Biomedical subjects

J Ryan

Publications and source records attributed to J Ryan.

At least 199 records · Page 11Linked to original sources
PubMed1990

The efficacy of preemployment drug screening for marijuana and cocaine in predicting employment outcome.

We present a prospective, controlled study of the association between preemployment drug screening results and employment outcomes in 2537 postal employees. For identified marijuana users, relative risk for turnover was 1.56 (95% confidence interval [Cl], 1.17 to 2.08); accidents, 1.55 (95% Cl, 1.16 to 2.08); injuries, 1.85 (95% Cl, 1.30 to 2.64); and discipline, 1.55 (95% Cl, 1.03 to 2.32). Their mean absence rate was 7.1% compared with 4.0% for nonusers. For identified cocaine users, relative risk for turnover was 1.15 (95% Cl, 0.65 to 2.05); accidents, 1.59 (95% Cl, 0.95 to 2.67); injuries, 1.85 (95% Cl, 1.01 to 3.39); and discipline, 1.40 (95% Cl, 0.62 to 3.17). Their mean absence rate was 9.8%. Our study shows that a preemployment drug screen positive for marijuana or cocaine is associated with adverse employment outcomes. The level of risk, however, is much less than previously estimated. This finding has important implications for the social, legal, and economic arguments for and against drug testing.

Absenteeism↗
PubMed1990

A common cytogenetic abnormality and DNA content alterations in dedifferentiated chondrosarcoma.

Dedifferentiated chondrosarcoma is an uncommon and aggressive variant of chondrosarcoma. The authors report the flow cytometric characteristics and cytogenetic findings in culture of two cases of dedifferentiated chondrosarcoma. The first case was DNA diploid by flow cytometry but had cytogenetic abnormalities consisting of breaks in the short arms of both chromosomes 1, resulting in deletion in one homolog and recombination in the other. In addition, cells from this tumor showed a balanced translocation between chromosomes 4 and 5, deletion of chromosome 9, and monosomy for chromosome 10. The second case was DNA aneuploid and more complex cytogenetically but had, in common with the first case, rearrangement and translocation at the same band on chromosome 1. These cytogenetic changes are compared with abnormalities previously reported for chondrosarcoma. Possible relationships between the nonrandom chromosomal abnormalities and subclassification among chondrosarcomas are discussed.

Aged↗
PubMed1990

Risk for occupational low-back injury after lumbar laminectomy for degenerative disc disease.

Thirty-two Postal Service applicants who had undergone laminectomies were classified as low risk for back injury after preplacement examinations and were subsequently hired for employment. Each was compared with six control subjects, who were matched by age, gender, date of hire, and job classification. The odds ratios for occupational back injury with 95% confidence intervals were 5.9 (1.9-18.8) overall and 9.1 (1.5-73.8) for letter carriers. Of subjects, 25% were injured, compared with 6% of controls. The median elapsed time between surgery and hire was 5.9 years for injured subjects and 6.8 years for uninjured subjects. A rank sum test comparing the elapsed times of the two groups was not significant (P = 0.30). Postal workers are at increased risk for back injury after laminectomy. The risk does not appear to decrease with increased time since surgery.

Adult↗
PubMed1990

Severity of disability due to occupational low back injury after lumbar laminectomy for degenerative disc disease.

Thirty-two postal workers were rated low risk in preplacement examinations after lumbar laminectomies for degenerative disc disease. They demonstrated an odds ratio for occupational back injury of 5.9 when compared with 192 control subjects matched by age, gender, employment date, and job classification. Each injured employee was subsequently observed for 2 years after injury. Data were collected on time lost from work due to the injury and incidence of surgical treatment. Injured subjects lost a median of 66 and a mean of 292.8 days from work, whereas injured control subjects lost a median of 8.5 and a mean of 24.8 days. Mean time lost per person hired was 73.2 days for subjects compared with 1.6 days for control subjects. Three of eight injured subjects required repeat surgery and three remain totally disabled. No injured control subjects required surgery and all resumed work.

Adult↗
PubMed1990

Effect of locally administered heparins on delayed-type hypersensitivity reactions.

Inflammatory reactions involved in delayed-type hypersensitivity (DTH) are associated with extravascular coagulation and fibrin deposition. Heparin and other anticoagulants administered systemically inhibit DTH reactions but the direct effect of intradermally injected heparin on the development of DTH skin responses has not been reported. The effects of heparin on the DTH reaction elicited by ovalbumin (OVA) in guinea pigs 1-3 weeks after sensitization were examined. Unfractionated heparin, low affinity heparin (LAH; non-anticoagulant) and high affinity heparin (HAH; anticoagulant) were injected together with suboptimal amounts of OVA. Heparin and LAH enhanced skin induration, LAH (0.5 micrograms) by an average of 50% above that due to OVA alone at 24 h (p less than 0.01). In contrast, HAH (0.5 micrograms) significantly reduced skin induration at 24 h. Heparin and LAH also significantly increased cellular infiltration with LAH having the greater effect. At 4 h the infiltrate consisted mainly of neutrophils whereas at 24 h mononuclear cells predominated. Fibrin deposition, assessed both by immunohistology and quantitation of radioactive fibrin extracted from skin test sites, was increased by 30% when OVA was tested in the presence of LAH. Mast cell heparin released locally at sites of DTH has the potential to modulate these reactions in either a pro- or anti-inflammatory manner. This study is the first to demonstrate differences in the capacities of LAH and HAH to modulate cell-mediated inflammation.

Animals↗
PubMed1990

Norfloxacin versus trimethoprim-sulfamethoxazole in the treatment of urinary tract infections.

In a controlled, randomized trial of 133 patients with proven urinary tract infections (UTIs), significantly more pathogens were found to be susceptible to norfloxacin than to trimethoprim-sulfamethoxazole (TMP-SMZ) (p less than 0.01). Among patients with pathogens susceptible to both drugs, more of those treated with norfloxacin were cured or improved (p = 0.06). When at least one patient variable, i.e., prior history of therapy, was corrected for, this difference became significant (p = 0.03). Norfloxacin eradicated 11 of 13 infections due to Pseudomonas aeruginosa and 6 of 7 due to enterococci. Five patients treated with norfloxacin and two treated with TMP-SMZ had relapses within 6 weeks. Significantly fewer adverse experiences occurred in patients receiving norfloxacin (p less than 0.01).

Adult↗
PubMed1990

Voluntarily informing others of positive HIV test results: patterns of notification by infected gay men.

Forty gay men who had recently learned that they were infected with human immunodeficiency virus (HIV) were interviewed to determine the frequency with which they voluntarily informed physicians, dentists, friends, family members, and current and past sexual partners of their positive test results. Ninety percent of the subjects informed a personal physician, and 48 percent of the subjects who sought dental care informed the dentist. Sixty-six percent of subjects with at least one current sexual partner notified every current sexual partner, although notification was not associated with a greater likelihood of safer sex practices. Ninety percent of the subjects who had past sexual partners made no attempt to inform them. Sixty-eight percent confided in at least one friend, but only 35 percent told a family member.

AIDS Serodiagnosis↗
PubMed1990

Multiple familial eccrine spiradenoma with cylindroma.

This report documents an association between multiple eccrine spiradenomata and multiple cylindromata in three generations of one family and provides further evidence to support previous contentions that these tumours are derived from a pluripotential basal cell. We propose that eccrine spiradenoma may be inherited as an autosomal dominant.

Adenoma, Sweat Gland↗
PubMed1990

The basic need for hospital cost accounting expands.

Due to the nature of the health delivery process, hospitals can neither control nor accurately predict the daily volume of the patients it will serve. Jim Ryan, marketing manager for CPSI discusses megatrends affecting cost reporting needs and the difficulties involved in hospital cost accounting.

Accounting↗
PubMed1989

Structural determinants of the factor IX molecule mediating interaction with the endothelial cell binding site are distinct from those involved in phospholipid binding.

Previous studies have indicated that Factor IX/IXa interacts in a specific and high affinity manner with a binding site on the endothelial cell surface. In this study, the contributions of the gamma-carboxyglutamic acid-containing (GLA) and growth factor domains to the finding of Factor IX to the endothelium were assessed. While GLA-containing peptides from Factors IX, X, and prothrombin were inhibitors of 125I-Factor IX-endothelial cell binding, the GLA peptide from Factor IX was about 250-800-fold more effective than those from prothrombin and Factor X, respectively. In contrast to its relative efficacy as an inhibitor of Factor IX-cell surface interaction, the Factor IX-GLA peptide neither bound to lipid vesicles nor inhibited Factor IX-lipid interaction. A synthetic peptide comprising the entire first epidermal growth factor (EGF) exon was also an inhibitor of 125I-Factor IX-endothelial cell binding, although it did not interact with lipid vesicles. Experiments with synthetic peptides comprising each of the three loops of the first EGF domain or the entire first EGF region with specific substitutions indicated the importance of determinants in both the first and probably third loops for Factor IX-endothelial interaction. In contrast, the second loop of the first EGF domain and the first loop of the second EGF exon are probably not involved in Factor IX-endothelial interaction based on their inability to block 125I-Factor IX binding to cells. These results indicate that determinants in both the GLA and the first EGF domain contribute to the specific binding of Factor IX to the endothelial cell surface and that structural requirements for Factor IX-cell surface interaction are distinct from those for Factor IX binding to lipids.

Amino Acid Sequence↗
PubMed1989

Protein structural requirements and properties of membrane binding by gamma-carboxyglutamic acid-containing plasma proteins and peptides.

The membrane-binding characteristics of a number of modified vitamin K-dependent proteins and peptides showed a general pattern of structural requirements. The amino-terminal peptides from human prothrombin (residues 1-41 and 1-44, 60:40) bovine factor X (residues 1-44), and bovine factor IX (residues 1-42), showed a general requirement for a free amino-terminal group, an intact disulfide, and the tyrosine homologous to Tyr44 of factor X for membrane binding. Consequently, the peptide from factor IX did not bind to membranes. Any of several modifications of the amino terminus, except reaction with trinitrobenzenesulfonic acid, abolished membrane binding by the factor X and prothrombin peptides. Calcium, but not magnesium, protected the amino terminus from chemical modification. The requirement for a free amino terminus was also shown to be true for intact prothrombin fragment 1, factor X, and factor IX. Although aggregation of the peptide-vesicle complexes greatly complicated accurate estimation of equilibrium binding constants, results with the factor X peptide indicated an affinity that was not greatly different from that of the parent protein. The most striking difference shown by the peptides was a requirement for about 10 times as much calcium as the parent proteins. In a manner similar to the parent proteins, the prothrombin and factor X peptides showed a large calcium-dependent quenching of tryptophan fluorescence. This fluorescence quenching in the peptides also required about 10 times the calcium needed by the parent proteins. Thus, the 1-45 region of the vitamin K-dependent proteins contained most of the membrane-binding structure but lacked component(s) needed for high affinity calcium binding. Protein S that was modified by thrombin cleavage at Arg52 and Arg70 showed approximately the same behavior as the amino-terminal 45-residue peptides. That is, it bound to membranes with overall affinity that was similar to native protein S but required high calcium concentrations. These results suggested that the second disulfide loop of protein S (Cys47-Cys72) and prothrombin (Cys48-Cys61) were involved in high affinity calcium binding. Since factor X lacks a homologous disulfide loop, an alternative structure must serve a similar function. A striking property of protein S was dissociation from membranes by high calcium. While this property was shared by all the vitamin K-dependent proteins, protein S showed this most dramatically and supported protein-membrane binding by calcium bridging.

1-Carboxyglutamic Acid↗