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Biomedical subjects

A J Berry

Publications and source records attributed to A J Berry.

At least 19 recordsLinked to original sources
PubMed2001

(17)O multiple-quantum MAS NMR study of high-pressure hydrous magnesium silicates.

Two (17)O-enriched hydrous magnesium silicates, the minerals hydroxyl-chondrodite (2Mg(2)SiO(4).Mg(OH)(2)) and hydroxyl-clinohumite (4Mg(2)SiO(4).Mg(OH)(2)), were synthesized. High-resolution "isotropic" (17)O (I = (5)/(2)) NMR spectra of the powdered solids were obtained using three- and five-quantum MAS NMR at magnetic field strengths of 9.4 and 16.4 T. These multiple-quantum (MQ) MAS spectra were analyzed to yield the (17)O isotropic chemical shifts (delta(CS)) and quadrupolar parameters (C(Q), eta and their "product" P(Q)) of the distinct oxygen sites resolved in each sample. The values obtained were compared with those found previously for forsterite (Mg(2)SiO(4)). The (17)O resonances of the protonated (hydroxyl) sites were recorded and assigned with the aid of (17)O [(1)H] cross-polarization and comparison with the spectrum of (17)O-enriched brucite (Mg(OH)(2)). Using all of these data, complete assignments of the five crystallographically inequivalent oxygen sites in hydroxyl-chondrodite and of the nine such sites in hydroxyl-clinohumite are suggested. The validity of these assignments are supported by the observation of a correlation between (17)O isotropic chemical shift and Si-O bond length. The (29)Si MAS NMR spectra of the two minerals were also obtained.

Journal Article↗
PubMed2001

Age versus comorbidities as risk factors for complications after elective abdominal aortic reconstructive surgery.

PURPOSE: This study estimated the association between age and in-hospital postoperative complications, controlling for known or suspected risk factors, in a series of patients undergoing elective abdominal aortic reconstructive surgery (AAR). METHODS: This retrospective cohort study of outcome data with multivariate logistic regression analysis was conducted at Emory University Hospital, a tertiary care, university-affiliated hospital. All patients undergoing elective AAR between Jan 1, 1986, and Aug 1, 1996, were included (n = 856). An estimate of the odds ratio (OR) and 95% CI for the association between patient age and in-hospital major morbidity or mortality after elective AAR was made, controlling for significant risk factors. RESULTS: Among the 856 patients, 170 had a nonfatal complication (136 with major and 34 with minor complications), and 11 patients (1.3%) died. The final logistic regression model demonstrated a mild association between increasing age and rate of major postoperative complications, including death (for each increase in age of 10 years: OR, 1.23; 95% CI, 1.00-1.52; P =.052). Other significant covariates in the final model included cardiac disease (OR, 2.84; 95% CI, 1.18-6.86; P =.020), pulmonary disease (OR, 1.96; 95% CI, 1.35-2.84; P =.0004), and renal disease (OR, 2.57; 95% CI, 1.66-3.99; P =.0001). Increasing age was associated with a moderate increase in the rate of death (for each increase in age of 10 years: OR, 2.74; 95% CI, 1.22-6.16; P =.015) in a model with cardiac disease as the only significant covariate (OR, 14.67; 95% CI, 3.46-62.16; P =.0003). CONCLUSION: For patients undergoing elective AAR, increasing patient age is associated with a small increase in risk for in-hospital morbidity or mortality. However, significant cardiac, pulmonary, or renal disease is associated with a much greater risk of postoperative complications, and, therefore, advanced age should not be the sole basis of exclusion for otherwise suitable candidates for elective AAR.

Age Factors↗
PubMed2000

The population genetics of the origin and divergence of the Drosophila simulans complex species.

The origins and divergence of Drosophila simulans and close relatives D. mauritiana and D. sechellia were examined using the patterns of DNA sequence variation found within and between species at 14 different genes. D. sechellia consistently revealed low levels of polymorphism, and genes from D. sechellia have accumulated mutations at a rate that is approximately 50% higher than the same genes from D. simulans. At synonymous sites, D. sechellia has experienced a significant excess of unpreferred codon substitutions. Together these observations suggest that D. sechellia has had a reduced effective population size for some time, and that it is accumulating slightly deleterious mutations as a result. D. simulans and D. mauritiana are both highly polymorphic and the two species share many polymorphisms, probably since the time of common ancestry. A simple isolation speciation model, with zero gene flow following incipient species separation, was fitted to both the simulans/mauritiana divergence and the simulans/sechellia divergence. In both cases the model fit the data quite well, and the analyses revealed little evidence of gene flow between the species. The exception is one gene copy at one locus in D. sechellia, which closely resembled other D. simulans sequences. The overall picture is of two allopatric speciation events that occurred quite near one another in time.

Animals↗
PubMed1999

Individual differences in reactivity to daily events: examining the roles of stability and level of self-esteem.

Unstable self-esteem is thought to reflect fragile and vulnerable feelings of self-worth that are affected by specific positive and negative events. Direct evidence for this contention is lacking, however. To redress this situation, we examined the extent to which level and stability of self-esteem predicted the impact that everyday positive and negative events had on individuals' feelings about themselves. Participants recorded the most positive and most negative event that occurred each day Monday through Thursday for a period of 2 weeks. They then indicated the extent to which each event made them feel better or worse about themselves. As anticipated, negative and positive events had a greater impact on the self-feelings of individuals with unstable as opposed to stable self-esteem (although the effect for positive events was marginal). Additional findings indicated that event qualities (i.e., self-esteem relevance and concerns about social acceptance/rejection) could account for the unstable self-esteem/greater reactivity link for negative events, but not for positive events. Negative, but not positive, events had a greater impact on the self-feelings of individuals with low as compared to high levels of self-esteem. Theoretical implications are discussed.

Adaptation, Psychological↗
PubMed1999

Azithromycin as treatment for disseminated Mycobacterium avium complex in AIDS patients.

This multicenter, randomized, dose-ranging study was performed to determine the safety and efficacy of two different doses of azithromycin for treating disseminated Mycobacterium avium complex (MAC) in patients with AIDS. Eighty-eight AIDS patients with symptoms and blood cultures consistent with disseminated MAC were treated with 600 or 1,200 mg of azithromycin daily for 6 weeks; 62 patients completed the entire 6 weeks of study. Of note, this study was done prior to the time when combination antiretroviral or anti-MAC regimens were the standard of care. Over the 6-week study period, symptomatic improvement was noted in both dose groups. Microbiological responses were comparable, with mean decreases of 1. 5 and 2.0 log CFU/ml in the high- and low-dose groups, respectively. Sterilization of blood cultures occurred in 54% of samples; patients with lower baseline colony counts were more likely to achieve culture negativity. Resistance developed in one patient. Gastrointestinal symptoms were the most common side effects and were more frequent in patients receiving 1,200 mg. Azithromycin is a useful alternative treatment for disseminated MAC infection in AIDS patients. Symptomatic improvement correlates with measurable decreases in mycobacterial load.

AIDS-Related Opportunistic Infections↗
PubMed1998

Multicenter study of contaminated percutaneous injuries in anesthesia personnel.

BACKGROUND: Anesthesia personnel are at risk for occupational infection with bloodborne pathogens from contaminated percutaneous injuries (CPIs). Additional information is needed to formulate methods to reduce risk. METHODS: The authors analyzed CPIs collected during a 2-yr period at 11 hospitals, assessed CPI underreporting, and estimated risks of infection with human immunodeficiency virus and hepatitis C virus. RESULTS: Data regarding 138 CPIs were collected: 74% were associated with blood-contaminated hollow-bore needles, 74% were potentially preventable, 30% were considered high-risk injuries from devices used for intravascular catheter insertion or obtaining blood, and 45% were reported to hospital health services. Corrected for injury underreporting, the CPI rate was 0.27 CPIs per yr per person; per full-time equivalent worker, there were 0.42 CPIs/yr. The estimated average 30-yr risks of human immunodeficiency virus or hepatitis C virus infection per full-time equivalent are 0.049% and 0.45%, respectively. Projecting these findings to all anesthesia personnel in the United States, the authors estimate that there will be 17 human immunodeficiency virus infections and 155 hepatitis C virus infections in 30 yr. CONCLUSIONS: Performance of anesthesia tasks is associated with CPIs from blood-contaminated hollow-bore needles. Thirty percent of all CPIs would have been high-risk for bloodborne pathogen transmission if the source patients were infected. Most CPIs were potentially preventable, and fewer than half were reported to hospital health services. The results identify devices and mechanisms responsible for CPIs, provide estimates of risk levels, and permit formulation of strategies to reduce risks.

Anesthesiology↗
PubMed1996

Tuberculosis makes a comeback.

Tuberculosis (TB) has plagued mankind for many centuries. In the past, the number of people affected with this potentially deadly disease declined, but there has been a recent dramatic increase in TB incidence. This increase is attributed largely to people who are coinfected with TB and HIV and to the development of resistant strains of Mycobacterium tuberculosis during the last decade. The US social infrastructure also has contributed to a rapid rise in TB cases due to adverse socioeconomic factors and an increase in the number of immigrants and people infected with HIV. This article gives a historical overview of TB; discusses its diagnosis, transmission and prevention modalities; and provides a case study about a TB-infected patient who required emergent surgical intervention.

Aged↗
PubMed1996

Percutaneous injuries in anesthesia personnel.

Anesthesia personnel are at risk for occupationally acquired blood-borne infections from human immunodeficiency virus, hepatitis viruses, and others after percutaneous exposures to infected blood or body fluids. The risk is greater after an infected, blood-contaminated, percutaneous injury, especially from a hollow-bore blood-filled needle, than from other types of exposures. Few data are available on the specific occupational hazards to anesthesia personnel from needles and other sharp devices. Fifty-eight percutaneous injuries (PIs) from anesthesia personnel in nine hospitals were analyzed. Thirty-nine of 58 PIs were from contaminated devices (all needles), and 19 were from uncontaminated devices or of unknown contamination status. Forty-three percent of contaminated percutaneous injuries (CPI) were classified as moderate (some bleeding) or severe (deep injury with profuse bleeding), and most were to health-care workers' hands. Fifty-nine percent of CPI were potentially preventable. Eighty-seven percent of CPI were from hollow-bore needles, and 68% of these were potentially preventable. The largest categories of devices causing CPI were needle on syringe, intravenous (i.v.) or arterial catheter needle-stylet, suture needle, and standard hollow-bore needle for secondary i.v. infusion. Most CPI occurred between steps of a multistep procedure (8%), were recapping related (13%), or occurred at other times after use (41%). No CPI were reported from use of needlestick-prevention safety devices. The devices and mechanisms of injury identified in this study provide specific data that may lead to prevention strategies to reduce the risk of PI.

Anesthesiology↗
PubMed1995

Injury prevention in anesthesiology.

Anesthesia personnel routinely perform procedures that put them at risk for contact with blood and body fluids. Some of these exposures are to skin and mucous membranes; many are percutaneous injuries associated with the frequent use of needled devices. The high risk in anesthesia procedures for contact with infected body fluids is associated with a high incidence rate of actual infection with bloodborne pathogens.

Accidents, Occupational↗