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Biomedical subjects

J S Jones

Publications and source records attributed to J S Jones.

At least 19 recordsLinked to original sources
PubMed1995

Differential male genetic success determines gene flow in an experimentally manipulated mouse population.

Sexual selection arises when genetically different males show heritable differences in reproductive success. Mouse mating behaviour involves both male competition and female choice. In this paper we show that introduced Y-linked DNA markers spread more extensively through a natural population than do genes inherited matrilineally. Differences in mating success between the sexes and among individual males may alter the pattern and rate of gene flow in natural populations. Another interesting possibility is that the success of the introduced Y chromosome may be attributable to so-called 'selfish' traits, such as sex-linked meiotic drive or intra-uterine competition. However, this study provides little unequivocal evidence to support this view. Differential success of introduced versus resident males may have implications for the reintroduction of endangered mammals into residual wild populations.

Animals↗
PubMed1995

Stethoscopes: a potential vector of infection?

STUDY OBJECTIVES: To survey emergency care providers about their stethoscope-cleaning measures and to determine the correlation between these measures and the extent of Staphylococcus carriage. DESIGN: Prospective cross-sectional analysis. SETTING: University-affiliated community hospital ED. PARTICIPANTS: One hundred fifty health care providers, comprising emergency medicine house staff and attending physicians (n = 50), ED nurses (n = 50), and prehospital personnel working in Kent County, Michigan (n = 50). INTERVENTIONS: Providers were asked how often they cleaned their stethoscopes and which cleaning agents were used. We then cultured each stethoscope by pressing the diaphragm on mannitol agar and incubating the culture aerobically for 48 hours. Staphylococcus aureus was identified by means of standard measures. We examined the effects of different cleaning agents on 24 stethoscopes. The numbers of colony-forming units (CFUs) before and after cleaning with alcohol, nonionic detergent, and antiseptic soap were noted. RESULTS: Overall, 48% of health care providers (74 of 150) cleaned their stethoscopes daily or weekly, 37% monthly, and 7% yearly; and 7% had never cleaned their stethoscopes. No significant differences were found in the hygiene routines of the three groups of providers surveyed. Use of an alcohol swab was the preferred method of cleaning. One hundred thirty-three stethoscopes (89%) grew staphylococci; 25 (19%) yielded S aureus. Mean staphylococcal bacterial counts ( +/- SD) were 52 +/- 78 CFUs per stethoscope among physicians, 46 +/- 92 CFUs among emergency medical service personnel, and 13 +/- 21 CFUs from the nursing staff (ANOVA, P = .01). Cleaning the stethoscope diaphragm resulted in immediate reduction in the bacterial count: by 94% with alcohol swabs, 90% with nonionic detergent, and 75% with antiseptic soap. CONCLUSION: Our results confirm that stethoscopes used in emergency practice are often contaminated with staphylococci and are therefore a potential vector of infection. This contamination is greatly reduced by frequent cleaning with alcohol or nonionic detergent.

Auscultation↗
PubMed1995

Metered-dose inhalers: do emergency health care providers know what to teach?

STUDY OBJECTIVE: To evaluate the ability of emergency health care providers and patients to demonstrate the proper use of metered-dose inhalers (MDIs). DESIGN: Prospective cross-sectional survey. SETTING: Five Midwestern community teaching hospitals. PARTICIPANTS: One hundred eighty-five health care providers, comprising emergency medicine house staff (n = 60), attending emergency physicians (n = 50), and ED nurses (n = 75). Also recruited were 100 consecutive ED patients with clinical history of asthma being treated with at least one MDI for more than 3 months. INTERVENTIONS: We surveyed patients and health care providers to assess their knowledge of and ability to use a conventional MDI. The subject's technique of using a placebo inhaler was graded by a trained observer using a checklist of six essential steps. RESULTS: Forty-one percent (76 of 185) of health care providers and 49% (49 of 100) of ED asthma patients performed at least five steps correctly (P = .24). There were no significant differences in performance scores among the emergency medicine house staff (42%), attending emergency physicians (34%), and ED nurses (45%). Only 15% of all health care providers and 17% of asthma patients were able to describe how to estimate the amount of medicine left in the canister. CONCLUSION: These results suggest that many patients use MDIs improperly. Emergency physicians, house staff, and nurses responsible for instructing patients in optimal inhaler use may lack even rudimentary skills with these devices.

Adolescent↗
PubMed1995

Tuberculosis in a day-care center, Kentucky, 1993.

In November, 1993, a 33-month-old child in a day-care center was diagnosed with tuberculosis (TB). To identify her source of infection, close contacts, other day-care children and staff were screened by tuberculin skin test (TST). TB registry and medical/laboratory records were reviewed. The only 2 community TB cases reported in the past 3 years were investigated. Of 164 children 2 were diagnosed with TB; their TSTs were > or = 10 mm but no specimens were obtained. Six children had TSTs > or = 5 mm. Of these 4 had TST conversions between December, 1993, and March, 1994. There were no additional positive TST children in June, 1994. No TB case was identified among staff or parents. A possible epidemiologic link with the index case was found for 1 community case. No source of infection was found for the other children. Possible explanations for not finding a source are: an as yet unidentified case in the day-care center or community; or false positive TST results in children related to low community prevalence of TB infection.

Child Day Care Centers↗
PubMed1995

Nutritional support of the hospitalized patient: a team approach.

Nutritional deficits have long been recognized as contributing factors to morbidity and mortality of hospitalized patients. A multi-disciplinary team approach to nutritional support has been shown to be superior to non-team approaches. A formal consultive nutritional support team has been active at St. Dominic Hospital since 1991. The benefits of our nutritional support team at St. Dominic Hospital are described. Acquisition of an Indirect calorimeter has improved measurements of caloric and substrate requirements. Individualized nutritional prescriptions more closely meet assessed patient needs. Utilization of less expensive, more physiologic enteral feeding routes have increased. Also, the number of total parenteral nutrition (TPN) bags admixed and wasted have decreased, despite an increase in the percent of patients with moderate to severe nutritional risk. The nutritional support service at St. Dominic Hospital has improved patient care while reducing cost to both the institutional and patient.

Adult↗
PubMed1995

Drug policy.

Explore the source record for details and available documents.

Cost-Benefit Analysis↗
PubMed1995

Registering TB.

Explore the source record for details and available documents.

Humans↗
PubMed1994

Racemic epinephrine in the treatment of laryngotracheitis: can we identify children for outpatient therapy?

The purpose of this study was to identify a cohort of children with laryngotracheitis (croup) who may be safely discharged from the emergency department (ED) after treatment with nebulized racemic epinephrine (RE), corticosteroids, and prolonged observation. Consecutive children (younger than 13 years of age) presenting to the ED with the diagnosis of laryngotracheitis were evaluated prospectively according to a croup scoring system. Sixty-one patients (4 to 108 months of age) with persistent inspiratory stridor at rest after 20 minutes of mist therapy who received nebulized RE (0.05) mL/kg of a 2.25% solution) and intramuscular dexamethasone (0.6 mg/kg) were enrolled in the study. Patients were observed in the ED while croup scores were assessed at 15, 60, 120, and 180 minutes. Croup scores were significantly improved (analysis of variance, P < .01) throughout the observation period in 31 patients (51%) who were discharged from the ED. Only one patient returned within 48 hours for further cool mist therapy. The maximum benefit from RE therapy was seen at 60 minutes. If a child had persistent resting stridor or a croup score greater than 2 at that time, hospitalization was inevitable. The 30 patients admitted to the hospital were younger (19.1 v 27.8 months) and had higher pretreatment croup scores (5.7 v 4.1). This was the first prospective study to identify a subset of children who have received RE to be safely discharged home after observation in the ED.

Administration, Inhalation↗
PubMed1994

Pyogenic sacroiliitis.

This report describes two cases of pyogenic sacroiliitis with remarkably similar histories. The initial diagnosis is often overlooked because of its rarity and poorly localized signs and symptoms. Clinical and radiological findings, as well as treatment measures, are discussed. Familiarity with this type of septic arthritis is essential if prompt and appropriate therapy is to be rendered.

Adult↗
PubMed1994

Computed tomographic findings after acute carbon monoxide poisoning.

Selective necrosis and degeneration of the globus pallidus are characteristic autopsy findings in patients with severe carbon monoxide (CO) poisoning. The objective of this study was to show that computed tomography (CT) may demonstrate these morphological changes in the brain during life, and provide a clue to prognosis. The authors reviewed the medical records of 19 consecutive patients with acute CO poisoning who underwent CT examination during hospitalization. Abnormal CT findings were found in 10 of the 19 patients (53%). The most common abnormal findings were low-density areas in the basal ganglia. These lesions were found in 7 of the 10 cases, and varied from small (limited to the globus pallidus) to large (extending to the internal capsule). Of the 10 patients with abnormal CT scans, 9 survived to hospital discharge but all had some degree of functional neurological impairment. Eighty-nine percent (8 of 9) of the patients with normal CT scans were discharged neurologically intact. Awareness of the potential for basal ganglia lesions in CO poisoning should lead to more accurate CT interpretation and may have significant prognostic implications.

Acute Disease↗
PubMed1994

Audit of pleural biopsies: an argument for a pleural biopsy service.

We audited 203 consecutive pleural biopsies performed by medical and geriatric firms over a 3-yr period in our hospital (1987-9). For firms without a special respiratory interest only two to three biopsies per yr were performed, compared with 23 per yr for a respiratory team. Twenty percent of biopsies failed to obtain pleural tissue, 50% revealed normal or non-diagnostic pleural changes and 30% provided a diagnosis. For the respiratory team that performed a third (68) of the biopsies the failure rate for obtaining pleura was 9% compared with 27% for other teams. In view of this disparity a pleural biopsy service was offered by the respiratory team during routine bronchoscopy lists. A repeat audit (1990-2) following the introduction of this service revealed that 60% (84) of 141 biopsies were performed by the respiratory team with their failure rate for obtaining pleura being lower at 6% as compared to 16% for the general physicians. Thirty-one percent of biopsies provided a definitive diagnosis, being higher for those performed by the respiratory team (37%) as opposed to 23% for general physicians.

Biopsy, Needle↗
PubMed1994

Negative and depressive symptoms in suicidal schizophrenics.

The aim of this study was to determine the value of positive, negative and depressive symptoms, and of the dexamethasone suppression test (DST), in differentiating schizophrenics with and without a history of suicide. Fifty-seven hospitalized patients with schizophrenia were assessed at the end of a neuroleptic free interval with the Brief Psychiatric Rating Scale (BPRS), the Hamilton Rating Scale for Depression (HRSD), and with a dexamethasone challenge. Suicide attempters were significantly more likely to meet criteria for major depression than nonattempters. Scores on the HRSD differentiated the two groups whereas the sums of positive and negative symptom items from the BPRS did not. DST a.m. and p.m. cortisol values differentiated suicide attempters from nonattempters and HRSD scores correlated significantly with cortisol levels. This study confirms the importance of depressive symptoms in schizophrenic patients with a history of suicide. Assessment of the hypothalamic-pituitary-adrenal axis in schizophrenia may also provide useful information.

Adult↗
PubMed1994

One retroviral RNA is sufficient for synthesis of viral DNA.

We used previously characterized spleen necrosis virus-based retroviral vectors and helper cells to study the strand transfers that occur during the reverse-transcription phase of a single cycle of retroviral replication. The conditions used selected only for formation of an active provirus rather than for expression of multiple drug resistance markers. In nonrecombinant proviruses the minus- and plus-strand DNA primer transfers were almost completely intramolecular. However, as previously reported, recombinant proviruses contained approximately equal proportions of inter- and intramolecular minus-strand DNA primer transfers. Thus, we conclude that in the absence of recombination, one molecule of retroviral RNA is sufficient for viral DNA synthesis. Large deletions and deletions with insertions were detected primarily at a limited number of positions which appear to be hot spots for such events, the primer binding site and regions containing multiple inverted repeats. At these hot spots, the rate of deletions and deletions with insertions visible with PCR was about 10% per genome per replication cycle. Other deletions and deletions with insertions (detectable with PCR) occurred at a rate of about 0.5%/kb per replication cycle. Crossovers occurred at a rate of about 6%/kb per replication cycle under single-selection conditions. This rate is comparable to the rate that we reported previously under double-selection conditions, indicating that retroviral homologous recombination is not highly error prone. The combined rates of deletions and deletions with insertions at hot spots (10% per genome per replication cycle) and other sites (0.5%/kb per replication cycle) and the rate of crossovers (6%/kb per replication cycle) indicate that on average, full-size (10-kb) type C retroviruses undergo an additional or aberrant strand transfer about once per cycle of infection.

Animals↗
PubMed1994

Copackaging of different-sized retroviral genomic RNAs: little effect on retroviral replication or recombination.

We tested the effect of copackaging retroviral vectors of different sizes on retroviral replication and recombination. Our results indicate little or no difference in replication or in the rate or pattern of the strand transfers leading to the formation of recombinant proviruses with size. The size difference of the vectors also allowed us to extend our previous analysis of the linkage of markers in the recombinant proviruses. We conclude that the observed linkage is inconsistent with the strand displacement/assimilation model of retroviral recombination.

Animals↗
PubMed1993

The shorthand vertical mattress stitch: evaluation of a new suture technique.

The shorthand vertical mattress suture is a new suture technique that provides the same amount of wound eversion in less time than the classic method. A randomized, prospective clinical trial was designed to test this hypothesis in a University-affiliated community hospital. Thirty patients who presented to the emergency department with traumatic lacerations requiring primary closure were eligible for this study. Wounds involving the hands, feet, or face were excluded. Patients meeting inclusion criteria were allocated randomly to have either shorthand or classic vertical mattress sutures. Wound information was collected on data sheets and included physician training level, repair time, number of knots placed, and degree of wound-edge eversion for each suture technique. Subjects were then asked to return to the emergency department in 7 to 10 days for wound assessment and suture removal. Thirty-six lacerations to the scalp, trunk, and extremities were evaluated. Shorthand vertical mattress sutures were used on 20 wounds (56%) and classic mattress sutures were used on 16 (44%) wounds. The shorthand stitch provided the same amount of wound eversion in half the time as the classic technique. No infectious complications, delayed wound healing, or cosmetic problems were observed with the shorthand technique. The shorthand vertical mattress stitch described is an efficient, alternative method for laceration repair without compromising wound eversion or cosmetic results.

Adult↗
PubMed1993

Cell fusion induced by the murine leukemia virus envelope glycoprotein.

To determine whether ecotropic murine leukemia virus (MuLV) envelope glycoproteins are sufficient to cause cell-to-cell fusion when expressed in the absence of virus production, we used an ecotropic MuLV, AKV, to construct env expression vectors that lack the gag and pol genes. The rat cell line XC, which undergoes cell-to-cell fusion upon infection with ecotropic MuLV, was transfected with wild-type env expression vectors, and high levels of syncytium formation resulted. Transfection of the murine cell line NIH 3T3 with expression vectors containing the wild-type or mutated env region did not result in syncytium formation. Immunoprecipitation analysis of the envelope glycoproteins expressed in NIH 3T3 and XC cells showed that the mature surface glycoprotein expressed in XC cells was of a much lower apparent molecular weight than that expressed in NIH 3T3 cells. Further characterization showed that most if not all of this difference was the result of differences in glycosylation. Finally, site-directed mutagenesis was used to introduce several conservative and nonconservative changes into the amino-terminal region of the transmembrane protein. Analysis of the effect of these mutations confirmed that this region is a fusion domain.

3T3 Cells↗
PubMed1993

Alteration of location of dimer linkage sequence in retroviral RNA: little effect on replication or homologous recombination.

Retrovirus particles contain a dimer of retroviral genomic RNA. A defined region of the retrovirus genome has previously been shown to be important for both dimerization and encapsidation. To study the importance of the position of this encapsidation and dimerization signal for retroviral replication and homologous recombination, we used a previously described spleen necrosis virus-based helper cell system. This system allows retroviral vectors with multiple genetic markers to be studied after a single cycle of retroviral replication. The sequence responsible for dimerization, the encapsidation/dimer linkage sequence (E/DLS), was moved from its normal location near the 5' end of the retroviral genome to a location near the 3' end of the genome. We characterized four pairs of retroviral vectors: (i) with both E/DLSs at the 5' ends of the genomes, (ii) with both E/DLSs at the 3' ends of the genomes, and (iii) two with one E/DLS at the 5' end of the genome and one at the 3' end of the genome. We found that moving the E/DLS to the 3' end of the genome resulted in at most an approximately factor of 5 reduction in virus titer in a single cycle of retroviral replication. Furthermore, we found no changes that were attributable to the alteration of the position of the E/DLS in the minus-strand DNA primer transfers or the plus-strand DNA primer transfers, the rate of homologous recombination, or the number of internal template switches in recombinant proviruses. These results indicate that any alignment or conformation necessary for retroviral replication or recombination is not the result of the position of the E/DLS.

Animals↗