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Biomedical subjects

S Brooks

Publications and source records attributed to S Brooks.

At least 19 recordsLinked to original sources

Reduction in vancomycin-resistant Enterococcus and Clostridium difficile infections following change to tympanic thermometers.

OBJECTIVE: To contain a nosocomial outbreak of vancomycin-resistant Enterococcus (VRE). DESIGN: Intervention study, with comparison of incidence rates before and after intervention to assess whether changes in incidence followed the intervention and were greater than expected based on trends observed before the intervention. SETTING: A 343-bed acute-care hospital serving a predominantly elderly population referred from nursing homes, as well as patients admitted from the community. METHODS: Interventions strategies were tested on three high-risk nursing stations. These included enhanced environmental sanitation; intensive staff retraining in Universal Precautions, body substance isolation, and proper use of gloves; and the use of tympanic thermometers to avoid possible rectal or oral VRE transmission during temperature taking. RESULTS: Nosocomial VRE infections were reduced by 48% 9 months after switching to tympanic thermometers; incidence of Clostridium difficile infections also was reduced. As a result, tympanic thermometers were introduced facilitywide; additional observation for 20 months showed a risk reduction of 60% for VRE and 40% for C difficile. CONCLUSION: Cross-transmission of VRE and C difficile during temperature taking may result in bowel colonization, placing the patient at increased risk for infection. This risk may be reduced by the use of tympanic thermometers.

Anti-Bacterial Agents

Molecular characterisation of ovarian cathepsin D in the rainbow trout, Oncorhynchus mykiss.

In fish, cathepsin D, an aspartyl protease, is believed to mediate the processing of yolk proteins in the oocyte. Cathepsin D, therefore, is vital for the production of a viable egg. This study set out to isolate and sequence the cDNA encoding cathepsin D, and to determine the developmental expression of the message in the ovary and subsequently during embryogenesis in the rainbow trout, Oncorhynchus mykiss. The full-length trout cathepsin D cDNA is 1847 base pairs (bp) long, encoding a protein of 400 amino acids (aa). The sequence consists of a putative signal peptide of 18 aa, a prosequence extending 46 aa and a mature peptide of 336 aa. The deduced sequence of rainbow trout ovarian cathepsin D shows significant homology with cathepsin D in mammals (human; 81% aa similarity), in the chicken (80% aa similarity) and in Xenopus (74% aa similarity). Our data support the contention that the primary structure of cathepsin D is highly conserved across the vertebrate phyla, from mammals to fish. Unlike cathepsin Ds in other species, however, rainbow trout cathepsin D appears to have only one putative N-glycosylation site, rather than two. The mRNA for 'ovarian' cathepsin D was expressed in both ovarian and non-ovarian tissues (liver, muscle, spleen and testis). During the development of the ovary, the highest expression levels of cathepsin D mRNA were seen at around the onset of vitellogenesis, a time when the oocytes are starting to sequester large quantities of yolk proteins. Northern hybridisation did not detect cathepsin D mRNA in either unfertilised eggs, or in fertilised eggs until after gastrulation, indicating that there is little, if any, de novo synthesis of this message at these stages of development. However, the mRNA for cathepsin D was detectable at the eyed embryo stage, and the expression of the gene increased towards the end of embryonic development.

Amino Acid Sequence

A simple monoclonal antibody based ELISA for free protein S. Comparison with PEG precipitation.

A simple monoclonal antibody based ELISA for free Protein S, compatible with out existing ELISA for total Protein S has been developed, and its performance compared with the conventional PEG precipitation method of free Protein S assay. The normal range (mean +/- 2 SD) was 0.19-0.54 iu/ml free Protein S. The mean intra assay variation was 5.24% and the mean inter assay variation was 5.50%. A total of 102 routine diagnostic samples from patients referred for prothrombotic investigation (six assays for each method) were assayed by PEG precipitation (mean 0.32 iu/ml, SD 10.60), and the monoclonal ELISA (mean 0.34, SD 0.9). Paired t-test analysis of the two data sets indicated no significant difference between them (P < 0.001). In this sample population, there was no significant difference in free Protein S values when assayed by monoclonal based ELISA or by PEG precipitation. The monoclonal assay has proved to be reliable, accurate and precise. The monoclonal ELISA is simpler, quicker and easier to perform in routine use. Data generated is directly comparable to that generated by PEG precipitation. This methodology would be suitable for laboratories currently measuring Protein S by ELISA.

Analysis of Variance

A mixed foodborne outbreak with Salmonella heidelberg and Campylobacter jejuni in a nursing home.

OBJECTIVE: To investigate a mixed Salmonella heidelberg and Campylobacter jejuni foodborne outbreak in a nursing home. DESIGN: Retrospective cohort study with a nested case-control design. Cases were defined by positive stool-culture results. Controls needed to be both asymptomatic and culture-negative. SETTING AND PATIENTS: Residents of a 580-bed nursing home in Brooklyn, New York. RESULTS: Of the 580 residents, 119 (21%) developed illness. Of the 93 symptomatic patients who submitted specimens, cultures were positive for S heidelberg in 24 (26%), C jejuni in 14 (15%), and both microorganisms in 25 (27%). Only the pureed diet was associated highly with infection by either Salmonella (odds ratio [OR], 17.6; 95% confidence interval [CI95], 4.8-68.7; P < .001), Campylobacter (OR, 13.3; CI95, 3.2-59.2; P < .001), or both organisms (OR, 8.9; CI95, 2.7-30.3; P < .001). Among the 42 pureed foods served during the 5 days before the outbreak, five meat or poultry items were associated most strongly with culture positivity. Of these five meat items, only a chopped-liver salad was implicated by the two employees reporting illness. A reported food-handling error occurred when ground, cooked chicken livers were placed in a bowl containing raw chicken-liver juices. INTERVENTION: Recommendations for proper cleaning and sanitizing of kitchen equipment to prevent cross-contamination between raw and cooked foods. CONCLUSIONS: Mixed foodborne outbreaks occur rarely. During this outbreak, contamination of a single food item with multiple bacterial pathogens was the likely source of transmission. Improper food-handling techniques that promote growth of one microorganism also allow growth of other pathogens that may be present. Because different sources and routes of transmission may be implicated for different pathogens, specific preventive measures may vary depending on the organisms involved.

Campylobacter Infections

Interleukin-1 beta inhibits phospholamban gene expression in cultured cardiomyocytes.

Phospholamban is a key regulatory protein that defines diastolic function. Proinflammatory cytokines interleukin-1 beta (IL-1 beta) and tumor necrosis factor-alpha (TNF-alpha) can depress contractility and intracellular Ca2+ currents and transients. An alteration in phospholamban expression is a possible pathway by which these cytokines modulate cardiac function. To test this hypothesis, primary cultures of neonatal rat cardiomyocytes were incubated with IL-1 beta, TNF-alpha, or both, and the level of phospholamban transcripts was examined by Northern blot analyses. Phospholamban transcript levels were decreased approximately equal to 50% (P < .0001) in cells exposed to 2 ng/mL IL-1 beta (20 hours), whereas TNF-alpha had no effect. Western blot analyses showed that IL-1 beta also reduced phospholamban protein levels (60% of control, P < .0001). The effects on transcript levels were gene specific; IL-1 beta induced transcripts for inducible NO synthase (iNOS), did not alter GAPDH transcripts, and reduced sarcoplasmic reticulum Ca(2+)-ATPase (65% of control, P < .001) transcripts. Cardiomyocytes treated with IL-1 beta showed no alterations in basal contractile parameters (maximum velocity of contraction and relaxation and maximal amplitude of contraction) but were unresponsive to beta-adrenergic stimulation. Studies performed in the presence of second-messenger inhibitors showed that the effect of IL-1 beta on phospholamban transcript levels was blocked by dexamethasone, was insensitive to inhibitors of iNOS, cyclooxygenase, or tyrosine kinases, but was enhanced by the addition of the protein kinase inhibitor staurosporine. These data demonstrate that IL-1 beta alters the expression of phospholamban, a key regulator of cardiac contractility, at both the transcript and protein levels. The results suggest novel mechanisms by which IL-1 beta may modify cardiac function.

Animals

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Crime

Motor actions of eliprodil in the normal and monoamine-depleted mouse: a role in the treatment of Parkinson's disease?

The non-competitive NMDA polyamine site antagonist, eliprodil, was examined for its effects on exploratory activity in non-habituated mice and for its antiakinetic potential in reserpine-treated mice. A low dose of eliprodil (5 mg/kg) weakly stimulated locomotion in naive animals, whilst higher doses depressed rearing (20-40 mg/kg) and grooming (40 mg/kg), consistent with a sedative action. At no dose did eliprodil cause ataxia. In 24 h reserpine-treated mice, eliprodil (10-40 mg/kg) reversed akinesia, but this effect was subject to considerable inter-animal variation and was not statistically significant. Eliprodil did not alter the motor recovery elicited by the dopamine D1 agonist SKF 38393, or the dopamine D2 agonist RU 24213, and suppressed the motor stimulation induced by L-DOPA. These results indicate that eliprodil displays a far lower propensity than many other NMDA receptor antagonists for disturbing posture and gait, but lacks the essential motor stimulant action required to make it a safe and effective antiparkinsonian agent, at least in the reserpine-treated mouse model of Parkinson's disease.

2,3,4,5-Tetrahydro-7,8-dihydroxy-1-phenyl-1H-3-ben

Mechanisms controlling egg size and number in the rainbow trout, Oncorhynchus mykiss.

Female rainbow trout (Oncorhynchus mykiss) produce a single batch of eggs each year; synchronous growth of oocytes, all of which are ovulated at the same time, occurs in the two ovaries. To examine the regulatory mechanisms controlling egg size and number, virgin female rainbow trout were subjected to unilateral ovariectomy (ULO) during early vitellogenesis, and oocyte recruitment and growth in the remaining ovary were monitored. The study also set out to determine whether the presence of a second population of smaller oocytes in the maturing pool (induced by ULO) affected the timing of ovulation and/or the size of the eggs ovulated. Two months after ULO, there was no difference in the gonadosomatic index between ULO fish and controls. Compensatory ovarian hypertrophy resulted from the recruitment of a second population of primary oocytes into the vitellogenic pool. This population of smaller maturing oocytes in the ULO fish displayed growth rates up to twice those of the population of larger oocytes in the same ovary and of oocytes in controls. The growth rate of the population of larger oocytes in the ULO fish was not altered by the recruitment of a second maturing population. One month after ULO, fish had a lower concentration of plasma estradiol-17 beta than did controls; subsequently the concentrations of plasma estradiol-17 beta in the ULO and control groups were similar. After ULO, plasma levels of vitellogenin in the ULO fish did not differ from those in the control group throughout the study. At or close to ovulation, the fecundity of ULO fish was 75-80% that of controls. In the control group, oocytes appeared to reach a certain critical size before they were ovulated, and fish with higher fecundity ovulated later than their less fecund counterparts. ULO did not affect the timing of ovulation, and ULO fish ovulated eggs with a considerably greater size-range than did controls.

Animals

Is fasting necessary before prilocaine Bier's block?

OBJECTIVE: To determine whether fasting is necessary before intravenous regional anaesthesia (Bier's block). METHODS: A questionnaire study was carried out to assess accident and emergency (A&E) departments' policies and opinions in relation to Bier's block anaesthesia. Questionnaires were sent to 282 A&E consultants, of whom 216 replied (77% response rate). RESULTS: About 5000 Bier's block procedures are carried out each year in the United Kingdom. Intravenous regional anaesthesia appears safe. Over one third of units did not fast their patients. The complication rate was similar in fasted and unfasted groups. CONCLUSIONS: Starvation of the patient before intravenous regional anaesthesia is not necessary and should be abandoned.

Anesthesia, Conduction

Measles vaccination levels of children enrolled in WIC during the 1991 measles epidemic in New York City.

OBJECTIVES: This study assessed measles vaccination rates and risk factors for lack of vaccination among preschool children enrolled in the Special Supplemental Food Program for Women, Infants, and Children (WIC) during the 1991 measles epidemic in New York City. METHODS: Children aged 12 to 59 months presenting for WIC certification between April 1 and September 30, 1991, at six volunteer WIC sites in New York City were surveyed. RESULTS: Of the 6181 children enrolled in the study, measles immunization status was ascertained for 6074 (98%). Overall measles coverage was 86% (95% confidence interval [CI] = +/- 1%) and at least 90% by 21 months of age (95% CI = +/- 1%). Young age of the child, use of a private provider, and Medicaid as a source of health care payment were risk factors for lack of vaccination (P < .001). CONCLUSIONS: During the peak of a measles epidemic, measles immunization rates were more than 80% by 24 months of age in a sample of WIC children. The ease of ascertaining immunization status and the size of the total WIC population underscore the importance of WIC immunization initiatives.

Child, Preschool

The immunization of children enrolled in the Special Supplemental Food Program for Women, Infants, and Children (WIC). The impact of different strategies.

OBJECTIVE: To assess the impact of different interventions to increase measles vaccination coverage among preschool children enrolled in the Special Supplemental Food Program for Women, Infants, and Children (WIC). DESIGN: Public health intervention trial. SETTING: Six volunteer WIC sites in New York City. STUDY PARTICIPANTS: Children aged 12 to 59 months presenting for WIC certification between April 1 and September 30, 1991, who were eligible for measles vaccination. INTERVENTIONS: Two WIC sites were assigned at random to one of three immunization strategies: (1) escort: child was escorted to a nearby pediatric clinic for immunization; (2) voucher incentive: the family returned monthly, rather than every 2 months, to pick up WIC food vouchers until the child was immunized; or (3) referral: the family was passively referred for immunization. MAIN OUTCOME MEASURE: Proportion of eligible children receiving measles vaccination. RESULTS: Of children eligible for measles immunization, 74% (618/836) were immunized. Children at escort sites were 5.5 times (relative risk [RR] = 5.5; 95% confidence interval [CI], 3.7 to 8.1) and those at voucher incentive sites were 2.9 times (RR = 2.9; 95% CI, 1.9 to 4.5) more likely to be immunized than children at referral sites. Children were immunized more rapidly at escort sites (median, 14 days) and voucher incentive sites (median, 26 days) than at referral sites (median, 45 days; P < .001). CONCLUSIONS: Both escort and voucher incentive models resulted in more children being immunized more rapidly than passive referral. Because of ease of administration, voucher incentives may be a more suitable immunization intervention for use at WIC sites, with addition of escort where feasible.

Female

Haematological and acute-phase responses associated with delayed-onset muscle soreness in humans.

Delayed-onset muscle soreness following unaccustomed or eccentric exercise is associated with inflammation, tissue necrosis and the release of muscle enzymes (Newham et al. 1983). We have investigated the time course of changes in circulating leucocytes and serum levels of some acute phase reactants, serum creatine kinase activity (CK) and muscle pain after a 40-min bout of bench-stepping exercise in eight healthy untrained subjects. Leg muscle soreness was greatest 2 days after the exercise bout. Peak serum CK values [mean (SD) 540 (502) IU.1-1] occurred 1-7 days post-exercise. Serum C-reactive protein (CRP) was unchanged from pre-exercise levels [7.8 (3.4) mg.1-1] immediately post-exercise [7.9 (2.3) mg.1-1] but rose to a peak of 17.0 (3.9) mg.1-1 1 day post-exercise, thereafter declining to basal levels. Serum levels of iron and zinc fell below pre-exercise levels for 1-3 days post-exercise. Serum albumin, IgG and IgM fell below pre-exercise levels from 1 day post-exercise, reaching minimal values (about 80% of basal levels) at 7 days post-exercise. The exercise did not appear to significantly affect serum levels of alpha-1-antitrypsin and alpha-1-acid glycoprotein. Two and three days after the exercise bout the circulating numbers of total leucocytes, neutrophils, monocytes and basophils fell 15-20% below pre-exercise levels, whereas lymphocytes, eosinophils and platelets were unchanged. The results indicate that a rapid acute phase inflammatory response is initiated within 1 day of a bout of exercise that induces delayed-onset muscle soreness, and that any later tissue necrosis that may occur is not accompanied by further marked changes in acute-phase reactants such as CRP.

Acute-Phase Proteins

Cardiorespiratory, hormonal and haematological responses to submaximal cycling performed 2 days after eccentric or concentric exercise bouts.

Eccentric muscle actions are known to induce delayed-onset muscle soreness (DOMS) and muscle weakness (reduced static strength and dynamic peak power output) that may persist for several days. The aim of the present study was to determine whether DOMS-inducing exercise affects physiological responses to subsequent submaximal dynamic exercise. Physiological and metabolic responses to a standardized exercise task were measured 2 days after the performance of an eccentric or concentric exercise bout. Six healthy, untrained male subjects aged 30 +/- 7 years (mean +/- S.D.) performed repeated eccentric contractions during 30 min of bench stepping (47-cm step, 15 steps min-1). On another occasion, they performed concentric contractions by walking uphill (8% incline) for 30 min at 5 km h-1, which elicited a similar heart rate response to bench stepping. Two days after the eccentric or concentric exercise, the subjects cycled for 15 min on an electrically braked cycle ergometer at a work rate (172 +/- 37 W) equivalent to 80% VO2 max. The order of the preceding treatments was randomized and the treatments were carried out 2 weeks apart. Two days after the eccentric exercise, all subjects reported leg muscle soreness and exhibited elevated levels of serum creatine kinase activity (P < 0.01) and plasma cortisol concentration (P < 0.05). After uphill walking, the subjects were not sore and serum creatine kinase activity was unchanged. Minute volume, breathing frequency, respiratory exchange ratio, heart rate, rating of perceived exertion, venous blood lactate concentration and plasma cortisol concentration were all higher (P < 0.05) during cycling after eccentric exercise compared with after uphill walking. Increases in plasma catecholamine concentrations and numbers of circulating leucocytes after cycling at 80% VO2 max for 15 min were similar under both experimental conditions, but the delayed leucocytosis (at 150 min post-exercise) was significantly greater (P < 0.01) for the post-eccentric exercise condition. We conclude that dynamic submaximal exercise performed 2 days following exercise with a large eccentric component produces physiological responses that are indicative of a higher relative exercise stress. It is likely that such effects will significantly limit the level and duration of exercise that can be achieved in subsequent training bouts over several days.

Adult

The physician decision-making process in transferring nursing home patients to the hospital.

BACKGROUND: Each year more than 25% of nursing home patients are transferred to the emergency department or hospital for evaluation and treatment of infection. These transfers may have an adverse impact on the quality and cost of patient care. This study examined physician assessment and management of acute infections in the nursing home. METHODS: A cross-sectional study was conducted of all acute urinary tract infections and lower respiratory tract infections occurring from February through June 1991 in eight randomly selected urban nursing homes. The numbers of transfers to the emergency department of hospital were recorded along with identification of the clinical, psychosocial, and institutional factors that influenced the physician's decision to transfer. RESULTS: Three hundred fifty-nine patients had 258 urinary tract infections and 219 respiratory tract infections. Eighty-one (17%) of these events resulted in transfer to a hospital for evaluation (16/81) and/or admission (65/81). Less than one third (30.4%) of the events caused the patient to be examined in the nursing home by a physician before the decision to transfer to the hospital. The mean time between the staff notification of an acute event and physician response by telephone was 5.12 hours. Independent mobility (P < or = .05), a transfer to the hospital during the previous 6 months (P < or = .01), and fewer nursing home laboratory tests and treatments (P < or = .01) were all associated with hospital transfer. CONCLUSIONS: In this sample of acutely ill nursing home patients, physicians collected limited clinical data before the decision to transfer. Although some transfers may be appropriate, a reduction in the transfer rate may reduce health care costs and limit the risk of iatrogenesis, thus improving the outcome of acute illnesses occurring in the nursing home.

Acute Disease

Risk factors and mortality among black, Caucasian, and Latina women with acute myocardial infarction.

The purpose of this study was to examine the clinical outcome of acute myocardial infarction among women of three ethnic/racial groups and to determine whether observed differences in outcome are explained by differences in associated risk factors. Nine hundred seventeen (917) consecutive admissions occurred among 810 women, of whom 347 (42.8%) were Caucasian, 258 (31.9%) were black, and 205 (25.3%) were Latina. The overall mortality rate was 13%; the Caucasian rate was significantly higher than the Latina rate (16.9% vs 7%, p < 0.01), as was the black rate (13.8% vs 7%, p < 0.05). Comparing survivors with nonsurvivors among the three groups, hypertension was more common for survivors among blacks, as was a history of angina; in-hospital congestive failure was associated with a higher mortality for blacks and Caucasians, as was in-hospital angina for Caucasians. Univariate and multivariate logistic regression for the outcome variables of congestive failure, in-hospital angina, and mortality, showed race to be a significant factor in the lower mortality rate for Latinas in the univariate analysis. In the multivariate analysis, only in-hospital angina and congestive failure significantly influenced mortality. In this study of myocardial infarction among women of lower socioeconomic status, factors other than race were the primary influences on outcome.

Aged

Does the addition of pre-operative skin preparation with povidone-iodine reduce groin sepsis following arterial surgery?

Sixty-four consecutive patients undergoing elective vascular surgery involving exposure of the femoral artery at the groin were randomized to one of two groups. Group A (N = 34) received twice-daily skin preparation with 10% aqueous povidone-iodine for 48 h preoperatively, while group B (N = 30) did not. Both groups were examined on a daily basis following surgery and any discharge from the wound was recorded and sent for bacteriological culture. The groups were well matched for age, sex and the type of vascular graft material used. In group A there were six (18.7%) groin wound infections and in group B there were five (17.2%). In this series of patients the addition of preoperative skin preparation with 10% povidone-iodine to standard peri-operative prophylaxis had no effect on the incidence of postoperative groin wound sepsis.

Adult