Biomedical subjects

J R Edwards

Publications and source records attributed to J R Edwards.

At least 19 recordsLinked to original sources

PubMed1992

Maternal relaxin concentrations in diabetic pregnancy.

Maternal serum concentrations of relaxin, an insulin homologue produced both by the corpus luteum of pregnancy and by the fetoplacental unit, are highest in the first trimester and fall to their lowest level in the third trimester. Relaxin is thought to influence carbohydrate metabolism in the uterus, and it has been suggested that serum concentrations of relaxin in diabetic women are higher than those of non-diabetic women. We show that maternal serum relaxin concentrations are significantly higher at each stage of pregnancy in insulin-dependent diabetic mothers than in non-diabetic mothers. This elevation in relaxin concentrations is not related to other indices of diabetic control. The physiological importance of the higher concentrations of relaxin in the serum of diabetic women--in particular, whether they contribute to the higher incidence of major anomalies in the fetuses of diabetic mothers--is yet to be determined.

Female↗

PubMed1992

Detection of receptor-ligand interactions using surface plasmon resonance: model studies employing the HIV-1 gp120/CD4 interaction.

Surface plasmon resonance (SPR), a label-free, real time optical detection principle, has been investigated for its potential to detect and quantitate macromolecular ligand-ligate interactions. As model systems, the interactions of the HIV-1 envelope glycoprotein, gp120, and the monoclonal antibody L-71, with a soluble form of the T-cell receptor CD4 (sCD4), were investigated. In an effort to demonstrate potential analytical applications of this technology, operational characteristics of the SPR instrumentation (BIAcore, Pharmacia) including stability of the sensing surface and reproducibility in the measurement of such macromolecular interactions were investigated. In addition, the ability to detect and quantitate sCD4 directly from unfractionated cell culture supernatants, such as Streptomyces lividans, was investigated. The results demonstrate that SPR has potential in quantitating macromolecular interactions in both purified and crude samples and that the reproducibility in, and sensitivity of, such determinations is comparable to other techniques.

Antibodies, Monoclonal↗

PubMed1992

In vitro activity of meropenem and imipenem against mycobacteria: development of a daily antibiotic dosing schedule.

The activity of two carbapenem antibiotics, meropenem and imipenem, against Mycobacterium species was assessed by means of the Bactec 460 radiometric apparatus. This system allowed a result to be read in 4-10 days. The instability of imipenem, particularly, in the test system necessitated the development of a regimen of daily addition of antibiotic to permit a more accurate assessment of antibiotic activity to be made. When antibiotic-containing media are incubated for long periods, as is the case when determining antimycobacterial activity, the stability of test antibiotics is an important factor that must be considered.

Culture Media↗

PubMed1991

Secular trends in nosocomial primary bloodstream infections in the United States, 1980-1989. National Nosocomial Infections Surveillance System.

More than 25,000 primary bloodstream infections (BSIs) were identified by 124 National Nosocomial Infections Surveillance System hospitals performing hospital-wide surveillance during the 10-year period 1980-1989. These hospitals reported 6,729 hospital-months of data, during which time approximately 9 million patients were discharged. BSI rates by hospital stratum (based on bed size and teaching affiliation) and pathogen groups were calculated. In 1989, the overall BSI rates for small (less than 200 beds) nonteaching, large nonteaching, small (less than 500 beds) teaching, and large teaching hospitals were 1.3, 2.5, 3.8, and 6.5 BSIs per 1,000 discharges, respectively. Over the period 1980-1989, significant increases (p less than 0.0001) were observed within each hospital stratum, in the overall BSI rate and the BSI rate due to each of the following pathogen groups: coagulase-negative staphylococci, Staphylococcus aureus, enterococci, and Candida species. In contrast, the BSI rate due to gram-negative bacilli remained stable over the decade, in all strata. Except for small nonteaching hospitals, the greatest increase in BSI rates was observed in coagulase-negative staphylococci (the percentage increase ranged between 424% and 754%), followed by Candida species (219-487%). In small nonteaching hospitals, the greatest increase was for S. aureus (283%), followed by enterococci (169%) and coagulase-negative staphylococci (161%). Our analysis documents the emergence over the last decade of coagulase-negative staphylococci as one of the most frequently occurring pathogens in BSI.

Bacteremia↗

PubMed1991

The National Nosocomial Infections Surveillance System: plans for the 1990s and beyond.

The National Nosocomial Infections Surveillance (NNIS) System is an ongoing collaborative surveillance system among the Centers for Disease Control (CDC) and United States hospitals to obtain national data on nosocomial infections. This system provides comparative data for hospitals and can be used to identify changes in infection sites, risk factors, and pathogens, and develop efficient surveillance methods. Data are collected prospectively using four surveillance components: hospital-wide, intensive care unit, high-risk nursery, and surgical patient. The limitations of NNIS data include the variability in case-finding methods, infrequency or unavailability of culturing, and lack of consistent methods for post-discharge surveillance. Future plans include more routine feedback of data, studies on the validity of NNIS data, new components, a NNIS consultant group, and more rapid data exchange with NNIS hospitals. Increasing the number of NNIS hospitals and cooperating with other agencies to exchange data may allow NNIS data to be used better for generating benchmark nosocomial infection rates. The NNIS system will continue to evolve as it seeks to find more effective and efficient ways to measure the nosocomial infection experience and assess the influence of patient risk, changes in the delivery of hospital care, and changes in infection control practices on these measures.

Centers for Disease Control and Prevention, U.S.↗

PubMed1991

Surgical wound infection rates by wound class, operative procedure, and patient risk index. National Nosocomial Infections Surveillance System.

To perform a valid comparison of rates among surgeons, among hospitals, or across time, surgical wound infection (SWI) rates must account for the variation in patients' underlying severity of illness and other important risk factors. From January 1987 through December 1990, 44 National Nosocomial Infections Surveillance System hospitals reported data collected under the detailed option of the surgical patient surveillance component protocol, which includes definitions of eligible patients, operations, and nosocomial infections. Pooled mean SWI rates (number of infections per 100 operations) within each of the categories of the traditional wound classification system were 2.1, 3.3, 6.4, and 7.1, respectively. A risk index was developed to predict a surgical patient's risk of acquiring an SWI. The risk index score, ranging from 0 to 3, is the number of risk factors present among the following: (1) a patient with an American Society of Anesthesiologists preoperative assessment score of 3, 4, or 5, (2) an operation classified as contaminated or dirty-infected, and (3) an operation lasting over T hours, where T depends upon the operative procedure being performed. The SWI rates for patients with scores of 0, 1, 2, and 3 were 1.5, 2.9, 6.8, and 13.0, respectively. The risk index is a significantly better predictor of SWI risk than the traditional wound classification system and performs well across a broad range of operative procedures.

Centers for Disease Control and Prevention, U.S.↗

PubMed1991

Nosocomial infection rates in adult and pediatric intensive care units in the United States. National Nosocomial Infections Surveillance System.

To determine which intensive care unit (ICU) infection rate may be best for interhospital and intrahospital comparisons and to assess the influence of invasive devices and type of ICU on infection rates, we analyzed data from the National Nosocomial Infections Surveillance System. From October 1986 to December 1990, 79 hospitals reported 2,334 hospital-months of data from 196 hospital units. The median overall infection rate was 9.2 infections per 100 patients. However, this infection rate had a strong positive correlation with average length of ICU stay (r = 0.60, p less than 0.0001). When patient-days was used in the denominator, the median overall nosocomial infection rate was 23.7 infections per 1,000 patient-days. Although there was a marked reduction in the correlation with average length of stay, this rate had a strong positive correlation with device utilization (r = 0.59, p less than 0.0001). To attempt to control for average length of stay and device utilization, we examined device-associated nosocomial infection rates. Central line-associated bloodstream infection rates, catheter-associated urinary tract infection rates, and ventilator-associated pneumonia rates varied by ICU type. The distributions of device-associated infection rates were different between some ICU types and were not different between others (coronary and medical ICUs or medical-surgical and surgical ICUs). Comparison of device-associated infection rates and overall device utilization identified hospital units with outlier infection rates or device utilization. These data show that: (1) choice of denominator is critical when calculating ICU infection rates; (2) device-associated infection rates vary by ICU type; and (3) intrahospital and interhospital comparison of ICU infection rates may best be made by comparing ICU-type specific, device-associated infection rates.

Adult↗

PubMed1991

Comparison of rates of nosocomial infections in neonatal intensive care units in the United States. National Nosocomial Infections Surveillance System.

To determine nosocomial infection (NI) rates among neonatal intensive care units (NICUs) that are useful for interhospital comparison, we analyzed data reported in 1986-1990 from 35 hospitals that have level III NICUs and used standard National Nosocomial Infections Surveillance protocols and NI site definitions. Overall rates of NI were calculated as the number of NI per 100 patients (overall NI patient rates) or the number of NI per 1,000 NICU patient-days (overall NI patient-day rates). A strong positive association was found between overall NI patient rates and the neonates' average length of stay, a marker for duration of exposure to important risk factors. No correlation was found between overall NI patient-day rates and average length of stay. However, a strong positive correlation between overall NI patient-day rates and a measure of device utilization (total device-days/total patient-days x 100) was found. Additionally, a positive correlation between overall NI patient rates and device utilization was found. Stratification among the three birthweight groups (less than 1,500 g, 1,500-2,500 g, greater than 2,500 g) did not eliminate the need to control for variations in these factors among NICUs. Device-associated, device-day infection rates, calculated as the number of umbilical or central line-associated blood-stream infections per 1,000 umbilical or central line-days and the number of ventilator-associated pneumonias per 1,000 ventilator days, were not correlated with a unit's site-specific device utilization. These data suggest that calculation of device-associated NI rates in NICUs using device-days as the denominator helps to control for the duration of exposure to the primary risk factor and will be more meaningful for purposes of interhospital comparison.

Birth Weight↗

PubMed1991

Nosocomial infections in elderly patients in the United States, 1986-1990. National Nosocomial Infections Surveillance System.

We analyzed 101,479 nosocomial infections in 75,398 adult patients (greater than 15 years) that were reported to the National Nosocomial Infections Surveillance (NNIS) system between 1986 and 1990 by 89 hospitals using the NNIS hospital-wide surveillance component. Overall, 54% of the infections occurred in elderly patients (greater than or equal to 65 years). In the elderly, 44% of the infections were urinary tract infections (UTIs), 18% were pneumonias, 11% were surgical wound infections (SWIs), 8% were bloodstream infections (BSIs), and the remainder were infections at other sites. When we compared the infections in elderly patients with those in younger adult patients, ages 15 to 64 years, a far greater percentage of the infections in elderly patients were UTIs, and there were more pneumonias than SWIs. Elderly and younger patients with ventilator-associated pneumonia were about 1.5 times more likely to develop a secondary BSI than those with pneumonia not associated with ventilator use. When the pathogens isolated from the infections were compared to those reported to the NNIS system in 1984, the percentage that were coagulase-negative staphylococci had increased in both elderly and younger patients. The patient died in 12% of all of the infections. Surveillance personnel reported that 54% of the infections in elderly infected patients who died were related to death compared with 59% in younger infected patients who died. When the infection was related to the patient's death, it was most often pneumonia or a BSI. The risk of an infection-related death was significantly higher when the infected patient developed a secondary BSI. Infection prevention efforts should target infections that occur frequently, are amenable to intervention, and have an adverse outcome.

Age Factors↗

PubMed1991

Blood contacts during surgical procedures.

Operating room personnel are at risk for infection with blood-borne pathogens through blood contact. To describe the nature and frequency of blood contact and its risk factors, trained observers monitored a sample of operations performed by six surgical services at Grady Memorial Hospital, Atlanta, Ga, for 6 months. In 62 (30.1%) of 206 operations, at least one blood contact was observed. Of 1828 operating room person-procedures observed, 96 (5.3%) had 147 blood contacts (133 skin contacts [90%], 10 percutaneous injuries [7%], and four eye splashes [3%]). The mean number of blood contacts per 100 person-procedures was highest for surgeons (18.6). The frequency of percutaneous injury was similar among surgeons and scrub staff (mean, 1.2 per 100 worker-procedures for each group). Risk factors for surgeons' blood contacts were (1) performing a trauma, burn, or orthopedic emergency procedure (odds ratio [OR], 4.1; 95% confidence interval [CI], 2.0 to 8.7); (2) patient blood loss exceeding 250mL (OR, 2.1; 95% CI, 1.2 to 3.7); and (3) being in the operating room longer than 1 hour (OR, 3.3; 95% CI, 1.6 to 7.1). Of 110 blood contacts among surgeons, 81 (74%) were potentially preventable by additional barrier precautions, such as face shields and fluid-resistant gowns. Twenty-one (84%) of 25 blood contacts among surgeons in procedures in which all three risk factors were present were potentially preventable by additional barriers. Of 29 blood contacts among anesthesia and circulating personnel, 20 (69%) would have been prevented by glove use. For surgical procedures in which operating room personnel are at increased risk of blood contact, reevaluation of surgical technique, use of appropriate barrier precautions, and development of puncture-resistant glove materials are indicated.

Accidents, Occupational↗

PubMed1991

In utero arterial embolism from renal vein thrombosis with successful postnatal thrombolytic therapy.

Thromboembolic events in the pediatric age group occur most commonly in neonates, and newborns of diabetic mothers are particularly at risk. We report a newborn with right renal vein and inferior vena cava thrombosis who apparently embolized across the foramen ovale antenatally with resultant right brachial artery occlusion. The baby was delivered by cesarean section from an insulin-dependent diabetic mother. At the time of birth, there was severe right arm ischemia with absent brachial and radial pulses. There was clinical evidence of distal embolization with a "trash" lesion of the distal right middle finger as well as a midforearm area of full-thickness skin loss. Ultrasound demonstrated a right renal vein thrombosis and a 95% occlusion of the inferior vena cava. Regional urokinase therapy was instituted through a lower extremity vein with a 5,000 U/kg bolus and then 5,000 U/kg/h continuous infusion. Twelve hours of infusion of urokinase led to clinical resolution of the right arm ischemia, with return of pulses. Follow-up ultrasound showed the right renal vein thrombosis and inferior vena cava clot to be completely resolved. The right middle finger and forearm lesions subsequently have healed primarily. We report this as a case of in utero arterial embolization with successful postnatal therapy using regional urokinase infusion.

Arm↗

PubMed1991

National nosocomial infections surveillance system (NNIS): description of surveillance methods.

The National Nosocomial Infections Surveillance System (NNIS) is an ongoing collaborative surveillance system sponsored by the Centers for Disease Control (CDC) to obtain national data on nosocomial infections. The CDC uses the data that are reported voluntarily by participating hospitals to estimate the magnitude of the nosocomial infection problem in the United States and to monitor trends in infections and risk factors. Hospitals collect data by prospectively monitoring specific groups of patients for infections with the use of protocols called surveillance components. The surveillance components used by the NNIS are hospitalwide, intensive care unit, high-risk nursery, and surgical patient. Detailed information including demographic characteristics, infections and related risk factors, pathogens and their antimicrobial susceptibilities, and outcome, is collected on each infected patient. Data on risk factors in the population of patients being monitored are also collected; these permit the calculation of risk-specific rates. An infection risk index, which includes the traditional wound class, is being evaluated as a predictor of the likelihood that an infection will develop after an operation. A major goal of the NNIS is to use surveillance data to develop and evaluate strategies to prevent and control nosocomial infections. The data collected with the use of the surveillance components permit the calculation of risk-specific infection rates, which can be used by individual hospitals as well as national health-care planners to set priorities for their infection control programs and to evaluate the effectiveness of their efforts. The NNIS will continue to evolve in finding more effective and efficient ways to assess the influence of patient risk and changes in the financing of health care on the infection rate.

Centers for Disease Control and Prevention, U.S.↗

PubMed1991

Evaluation of vaccines against ovine dermatophilosis.

Intradermal vaccination of live crude filaments (vaccine A) was compared with a vaccine (vaccine B) consisting of a 45 kD zoospore protein and mucoid material coating filaments in its ability to protect sheep from experimental Dermatophilus congolensis infection. Fourteen and 21 days after challenge, vaccine A sheep had fewer lesions (P less than 0.001) than the vaccine B sheep. The lesions on the vaccine A sheep were also less severe 14 and 21 days after challenge (P less than 0.05, P less than 0.01 respectively). In a second study, vaccine A was assessed for its ability to protect against natural challenge. Ten weeks after contact with sheep with active and generalised dermatophilosis no difference was found between the number of lesions present on the vaccine A and unvaccinated sheep and no differences were found in the number of sheep in each group with active lesions.

Actinomycetales↗

PubMed1991

Relationship between Type A behavior pattern and mental and physical symptoms: a comparison of global and component measures.

Although the Type A behavior pattern (TABP) is typically considered a set of distinct components, most studies of TABP have used global measures, which collapse several components into a single index. These measures are inherently multidimensional and, as such, contain several conceptual and methodological problems. In this study, data from 240 executives were used to compare global and component TABP measures as predictors of mental and physical symptoms. Global measures included the Bortner scale, the Framingham scale, and the Jenkins Activity Survey. Component measures were constructed by recombining items from the global measures on the basis of results from previous confirmatory factor analyses (Edwards, Baglioni, & Cooper, 1990). Results indicate that the component measures were superior to the global measures in terms of number of relationships detected, interpretability, and total explanatory power. Implications for research and practice are discussed.

Coronary Disease↗

PubMed1991

Use of polymerase chain reaction for the early detection of HIV infection in the infants of HIV-seropositive women.

Forty-two infants of HIV-seropositive women were evaluated to determine the value of polymerase chain reaction (PCR) in the early detection of HIV infection. All infants less than 6 months old had a simultaneous PCR and culture for HIV. There was an 88% concordance between the two techniques. PCR results showed an excellent correlation with clinical outcome; no PCR-negative patient has subsequently been found to be infected. Occasional false-positive or equivocal PCR results did occur. There was one false-negative culture. PCR is a rapid and sensitive diagnostic test for the early diagnosis of HIV infection in infants at risk, but at present it should be performed in conjunction with other diagnostic tests and good clinical follow-up.

Adult↗

PubMed1990

The structural analysis of a levan produced by Streptococcus salivarius SS2.

The structure of a water-soluble levan produced by Streptococcus salivarius SS2 has been determined by means of various chemical and instrumental methods. Methylation and periodate oxidation studies demonstrate that the levan is comprised of D-fructofuranosyl backbone residues linked beta-(2----6) (about 70%) with beta-(2----1) branches (about 30%). 13C-N.m.r. spectral analysis of the polymer is consistent with the structure determined by chemical means.

Carbohydrate Sequence↗

PubMed1990

Examining the relationships among self-report measures of the Type A behavior pattern: the effects of dimensionality, measurement error, and differences in underlying constructs.

The most widely used self-report measures of the Type A behavior pattern (TABP) are the Bortner scale, the Framingham scale, and the Jenkins Activity Survey (JAS). Though high scores on each of these measures have been linked to the development of coronary heart disease, their intercorrelations are rather low, suggesting that they may reflect different aspects of TABP. This study indicates that the low correlations among the Bortner scale, the Framingham scale, and the JAS are due not only to differences in underlying constructs but also to measurement error and multidimensionality. These results also identify several psychometric problems, which raise serious questions regarding the use of these measures in TABP research. Suggestions for the development of new measures of TABP are offered.

Coronary Disease↗

PubMed1990

The relationship between psychosocial factors and breast cancer: some unexpected results.

A growing body of research suggests a link between psychosocial factors and breast cancer. Research in this area often contains methodological problems, however, such as small sample size, inadequate comparison groups, omission of important control variables, inclusion of only a few psychosocial variables, and failure to analyze moderating effects. To overcome these problems, the present study examined the link between breast cancer and multiple psychosocial variables (life events, coping, Type A behavior pattern, availability of social support) among 1,052 women with and without breast cancer. After controlling for history of breast cancer and age, we found very few significant relationships between psychosocial variables and breast cancer. Furthermore, the relationship between life events and breast cancer was not moderated by coping, Type A, or availability of social support. Methodological and substantive reasons for these findings are discussed.

Adaptation, Psychological↗