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Biomedical subjects

E L Larson

Publications and source records attributed to E L Larson.

At least 37 records · Page 2Linked to original sources

Hand washing: a ritual revisited.

This article summarizes a critical analysis of 18 studies that examined the link between hand washing and infection. Although several factors made it difficult to evaluate the effect of hand washing, the authors conclude that (1) hand washing can add incremental value to infection-control strategies in acute care settings, (2) patient hand hygiene may influence infection rates, and (3) the effect of "ideal" hand washing on nosocomial infection rates is unlikely to be quantifiable.

Cross Infection↗

Consistency and cost of home wound management by contract nurses.

The purposes of this descriptive study were to determine the consistency of wound care provided by home health care nurses with the physician's order and the agency's written wound protocol; and the type and cost of wound-management products and nursing services associated with home care. Eleven registered nurses were observed providing wound care in 117 home visits to 31 patients. In addition to the observational component, data were also collected by chart review to facilitate comparison of observed vs. documented care. There were statistically significant differences between observed care given and that which was documented in patients' records. Consistency of care for individual patients was high when care was delivered by the same nurse, but lower when different nurses were involved. The mean dollar value of supplies used for all visits was $9.40, and the average nursing charge per visit was $89.

Adult↗

Influence of human T-cell leukemia virus type I tax and rex on interleukin-2 gene expression.

The X region of human T-cell leukemia virus type I (HTLV-I) encodes two proteins that regulate viral gene expression. The tax protein is the product of the transactivator gene and has been shown to up-regulate the expression of some cellular genes controlling T-cell replication, including that of the interleukin-2 (IL-2) T-cell growth hormone and the alpha chain of its receptor (IL-2R). Several studies have shown that tax transactivation of the IL-2R alpha-chain promoter is mediated by binding sites for the transcriptional activator NF-kappa B, and this mechanism has also been implicated in the tax activation of IL-2 promoter activity. The rex gene product of HTLV-I regulates viral protein production by influencing mRNA expression and has been implicated in the stabilization of IL-2R alpha-chain mRNA. In the present studies, the ability of the tax and rex proteins to transactivate IL-2 gene expression has been reinvestigated. The ability of the tax protein to transactivate IL-2 promoter activity appears, at least in part, to be mediated by the recognition sequence for a DNA-binding complex known as CD28RC. Consistent with this hypothesis is the observation that tax-mediated activation of IL-2 gene expression is resistant to the immunosuppressive affects of cyclosporin A, a property postulated for the CD28RC binding complex. Unexpectedly, this tax-mediated up-regulation of IL-2 expression is synergized by the presence of the rex protein. These findings demonstrate that transactivation of IL-2 gene expression by tax is augmented by mechanisms distinct from NF-kappa B and raise the possibility that rex, as well as tax, contributes to the oncogenic capability of HTLV-I by altering the expression of the IL-2 gene in T cells infected with this retrovirus.

Antigens, CD↗

Wound management in home care: an assessment.

The purpose of this study was to determine the status of wound care management among home health agencies (HHAs) in the U.S. The survey was mailed to 562 randomly selected HHAs within all 10 HCFA regions. Two hundred and ninety-six agencies (53%) responded to the survey. The majority (56%) of the respondents did not have written policies and procedures specific to wound management. The investigators were able to analyze the documents of those who had indicated that they had written policies and sent copies of them (n = 87, 67%). The majority (76%) of these had separate wound assessment protocols, but only 14% had separate preventive skin assessment protocols. Sixty-four percent had treatment protocols for more than one type of wound, while the remaining 46% used no specific treatment protocol or used treatments based on physicians' orders only. Most of the HHAs with written wound management policies required documentation of wound status; however, only half had patient/caregiver teaching as part of the policy. Although there is a need for clinically useful, well-tested, standardized approaches to wound care, the results of this study indicated that there is inconsistency regarding wound care management among HHAs within the U.S.

Clinical Protocols↗

Handwashing practices and resistance and density of bacterial hand flora on two pediatric units in Lima, Peru.

The handwashing practices and bacterial hand flora of 62 pediatric staff members of a teaching hospital in Lima, Peru, were studied. Handwashing followed patient contact 29.3% of the time (204/697 contacts). Mean duration was 14.5 seconds, and significant differences in practices were found by unit (rehydration or neonatal intensive care), type of staff member (nurses or physicians), and type and duration of patient contact. Mean count of colony-forming units was log10 5.87 +/- 0.41, with significant differences in density of flora found between patient care and kitchen staffs. There was no significant effect of handwashing on counts of colony-forming units. Significant differences were also found by unit and by staff position with regard to species isolated and antimicrobial resistance of isolates. A more efficacious and cost-effective form of hand hygiene and a more prudent use of antimicrobial agents are indicated.

Colony Count, Microbial↗

Indigenous multiresistant bacteria from flowers in hospital and nonhospital environments.

The microbial flora of 60 vase water samples from cut flowers obtained from several environments, including a hospital, were examined in this study. Forty-one different bacterial species were identified, including 12 species of Pseudomonas. The mean total aerobic bacterial count per 500 ml of vase water was 4.5 x 10(8) organisms, and high levels of antibiotic resistance were found. To ascertain the origin of the bacteria found on the flowers as well as their growth patterns, natural cut flowers were compared with sterilized cut flowers in tap water over time. Although the density of organisms was similar, the flora in vase water of sterilized flowers consisted almost entirely of aerobic spore formers while mixed flora of gram-negative bacteria, staphylococci, aerobic spore formers, and fungi were isolated from natural flowers. Our results indicate that the multiply-resistant microbial flora found in vase water is indigenous to flowers, rather than originating from the environment in which they are placed, and that such water is a reservoir of large numbers of multiresistant organisms.

Bacteria↗

Alcohol-impregnated wipes as an alternative in hand hygiene.

The antimicrobial effectiveness of four hand-wash products for health care personnel included three liquid soaps that contained 4% chlorhexidine gluconate, 1% triclosan, or no antiseptic ingredient, respectively, and a 30% w/w ethyl alcohol-impregnated hand wipe. These products were evaluated for reduction in bacterial counts on hands after extended use of 15 handwashes per day for 5 consecutive days. The order of greatest to least log reduction among products at the end of the 5-day test period was chlorhexidine gluconate (2.01), triclosan (1.52), alcohol wipe (0.04), and control soap (0.03). Skin condition before and after handwash was assessed for each treatment group. Subjects reported less skin irritation with alcohol wipes than with the two antiseptic products. Repeated washing with alcohol wipes results in reductions in bacterial colony counts comparable with nonmedicated soap, sufficient to prevent transmission of pathogens by the hands in most situations that arise in nonacute health care settings. This evidence, in addition to increased user acceptability reported by the subjects who used alcohol wipes, suggests that alcohol wipes are an acceptable alternative to soap-and-water handwashing in nonacute health care settings.

Adult↗

Alcohol for surgical scrubbing?

To test the effects of four surgical scrub products on colonizing hand flora, 60 healthy adult volunteers were assigned by block randomization (12 subjects per group) to use one of the following formulations: 70% ethyl alcohol with 0.5% chlorhexidine gluconate (ALC); a liquid detergent base containing 1% triclosan (TRI); a liquid detergent base containing 4% chlorhexidine gluconate (CHG); a liquid detergent base containing 7.5% povidone-iodine (PI); or a nonantimicrobial liquid soap (control). Using standard protocol, subjects performed a surgical scrub daily for five consecutive days. Hand cultures were obtained at baseline and on test days 1 and 5 immediately after the scrub and following four hours of gloving. After the first and last scrubs, ALC, CHG and PI resulted in significant reductions in colonizing flora when compared to the control. Additionally, by day 5 ALC was associated with an almost 3-log reduction as compared to an approximate 1.5-log reduction for CHG and PI and less than a 1-log reduction of TRI and the control (p = .009). After four hours of gloving on both days 1 and 5, microbial counts on hands of subjects using ALC, TRI and CHG were significantly lower than counts for the control (p less than .001), whereas there was no significant difference in counts between the PI and control groups (p = .41). Skin assessment by study subjects rated products from least to most harsh as follows: control, TRI, CHG, ALC and PI p = .00001). It was concluded that ALC could be an efficacious and acceptable alternative for surgical scrubbing.

Adolescent↗

Microbial flora on the hands of health care personnel: differences in composition and antibacterial resistance.

The composition and antibiotic sensitivity pattern of bacteria recovered from the hands of nurses and physicians in two service units of a major teaching hospital were compared with those found in a control population. Significant differences in the composition of bacteria were found in dermatology and oncology unit personnel. Staphylococcus aureus was recovered from 31% of dermatology nurses and 37% of dermatology physicians compared with 20% of oncology nurses, 15% of oncology physicians, and 17% of controls. Oncology personnel had a significantly higher carriage of gram-negative bacteria, yeasts, and multiple antibiotic-resistant, aerobic coryneforms (group JK bacteria). Both dermatology and oncology nursing personnel were colonized by organisms resistant to multiple antibiotics. Methicillin resistance was found in 26% and 66% of the staphylococci recovered from dermatology and oncology nurses respectively. Flora from physicians on the two units had sensitivity patterns similar to controls.

Dermatology↗

Composition and density of microflora in the subungual space of the hand.

There were significant quantitative differences in the composition and density of microflora in different areas of the hands of 26 adult volunteers. The subungual spaces had an average log10 CFU of 5.39, compared with a range from 2.55 to 3.53 for other hand sites. In quantitative cultures from five subungual spaces in 26 subjects, coagulase-negative staphylococci were the dominant organisms, with Staphylococcus epidermidis, S. haemolyticus and S. hominis being the most frequently isolated species. Other bacteria recovered from subungual spaces included gram-negative bacilli in 42.3% of subjects, with Pseudomonas species composing 31.3% of this group, and coryneforms in 42.3% of subjects, with multiply resistant JK group coryneforms making up 12.5%. Yeasts were isolated from 69.0% of subjects sampled, with 51.3% of the yeasts identified as Candida parapsilosis. The subungual coagulase-negative staphylococci were susceptible to most antibiotics, with resistance to penicillin, ampicillin, and erythromycin detected in 23 to 38% of isolates.

Adolescent↗

Quantity of soap as a variable in handwashing.

The purposes of this study were to assess the effect of two quantities (1 mL or 3 mL) of four different handwashing products on reductions in log colony-forming units (CFU) from the hands and to determine the amount of liquid soap used for handwashing by personnel in one hospital. First, 40 subjects were assigned by block randomization to one of four handwashing products (4% chlorhexidine gluconate in a detergent base, two alcohol hand rinses, and a liquid, nonantimicrobial soap) to be used in either 1 mL or 3 mL amounts per wash. Each subject washed his or her hands 15 times per day for five days. After one and five days of handwashing there were significant reductions over baseline in log CFU between handwashing products (P less than 0.001). Additionally, subjects using 3 mL of antiseptic soap had significantly greater reductions in log CFU than those using 1 mL (P less than 0.001). Among subjects using control liquid soap there was no such dose response. Second, a survey of 47 members of a hospital nursing staff from nine specialty areas and ten individuals in the general population was conducted to measure amounts of two liquid soaps used for handwashing. Amount of soap ranged from 0.4 to 9 mL per handwash. Personnel working in clinical areas where patients were at high risk for nosocomial infection used significantly more soap than did others (P less than 0.05). We conclude that quantity of soap used for handwashing is one variable influencing the microbial counts on hands, and that the quantity of soap used by health care personnel varies considerably.

Bacteria↗

Comparison of four antiseptic products containing chlorhexidine gluconate.

The purpose of this study was to compare the antimicrobic efficacies of four formulations of chlorhexidine gluconate (CHG) for handwashing under frequent-use conditions. Fifty volunteers were assigned by block randomization to one of five products: one of two liquid detergents containing 4% CHG, a liquid detergent containing 2% CHG, a foam containing 4% CHG, and a nonantiseptic soap (control). Subjects washed their hands by a standardized technique 15 times per day for 5 days. After days 1 and 5 of handwashing, there was a significant reduction in log CFU for subjects using all four CHG-containing products compared with subjects using control soap and for subjects within each group after days 1 and 5 compared with the base-line CFU counts (all P less than 0.05). There were no significant differences between the four CHG products at any testing time. We conclude that all four formulations are satisfactory for clinical use.

Adult↗

Skin colonization with antibiotic-resistant (JK group) and antibiotic-sensitive lipophilic diphtheroids in hospitalized and normal adults.

A strict nutritional requirement for lipid and similar components of cell wall fatty acids and sugars are features common to both JK coryneforms (JK) that are resistant to multiple antibiotics and to lipophilic diphtheroids (LD) that are sensitive to antibiotics. We surveyed 123 subjects for LD and JK. Twenty-eight patients with leukemia (776 samples) were cultured longitudinally during 42 hospitalizations; 15 other patients hospitalized for at least two weeks and 80 controls were sampled once. JK were isolated from at least one of four skin sites in 82.1% of the leukemic patients, 73.3% of other patients, and 15.7% of controls. There was an inverse correlation between the density of LDs and JKs in all groups (P = .03). The perineum was the most frequent, and usually the first, site of JK colonization. Once present, colonization persisted for as long as follow-up continued. Systemic vancomycin did not eliminate or prevent skin colonization with JK. Leukemic patients may have a greater risk of JK infection but probably no increased risk of skin colonization.

Actinomycetales↗

Efficacy of alcohol-based hand rinses under frequent-use conditions.

Fifty volunteers randomly assigned to one of five hand washing agents (10 subjects per agent)--a nonantiseptic liquid soap (control), an antiseptic hand rinse containing 60% isopropyl alcohol (IPA) with emollients (Alc A), an antiseptic hand rinse containing 70% IPA and 0.5% chlorhexidine gluconate with emollients (Alc B), an antiseptic containing 4% chlorhexidine gluconate and 4% IPA (CHG), and 70% IPA--washed their hands 15 times per day for 5 days under supervision by using a standardized technique and measured amounts of test agent. Microbiologic samples of hand flora were obtained at base line and after hand washes 1 and 15 on test days 1 and 5. After the initial hand wash there were significant reductions over base line in aerobic and anaerobic log CFU among those using Alc A, CHG, and IPA. By the end of the first day of hand washing (15 washes), there were 2-log or greater reductions in aerobic counts among subjects using all antiseptics, but no significant reductions in controls. By the end of day 5, all agents produced significant reductions in aerobic (P = 0.0002) and anaerobic (P = 0.002) counts over control soap. Subject assessment of effects of hand washing on the skin and overall satisfaction varied significantly by product (P = 0.04 and 0.05, respectively). We conclude that alcohol-based hand rinses are highly efficacious, and such products are recommended as a health care personnel hand wash, particularly when sink and running water are inaccessible.

1-Propanol↗