Physician handwashing: what do parents want?

Transmission of micro-organisms from the hands of healthcare workers to patients is a major cause of healthcare-acquired infections. In 2002, the US Centers for Disease Control and Prevention (CDC) published guidelines for healthcare workers that included the recommendation for alcohol-based hand rub for hand hygiene during patient visits. In this prospective study we surveyed parental and healthcare workers' preferences for the hand hygiene practices of emergency physicians. The study comprised 99 parents of ill or injured children presenting to our emergency department and 100 healthcare providers (64 nurses, 29 physicians and seven nurse practitioners) within the department. There was a clear and similar preference by parents and healthcare workers for hand hygiene using soap and water over alcohol cleansing rubs. Furthermore, both groups preferred hand hygiene before and after the examination and wanted to observe the physician perform this procedure. In conclusion, families and healthcare worker preferences for hand hygiene are not in keeping with recommendations published by the CDC. Educational interventions are needed to disseminate the CDC's guidelines and to promote compliance with evidence-based recommendations for hand hygiene.

Inhibition of elastolysis by proteinase inhibitors from chick plasma and aorta.

Chick plasma contains inhibitor(s) against trypsin and elastase which also appear to retard the degradation of tropoelastin by arterial tissue extracts. Chick aorta extracts also contain similar inhibitors against elastase and trypsin. Both levels of the plasma inhibitor(s) and inhibitor(s) extracted from thoracic aorta increase during early stages of growth and maturation. There is a three- to four-fold increase in the levels of the inhibitor(s) in chick plasma and aorta between one to four weeks after hatching. Of particular interest are the observations that the presence of the inhibitor(s) retards the conversion of soluble elastin (tropoelastin) to smaller elastin peptides. Subsequently, it is speculated that in addition to other vital roles, such proteinase inhibitors may also act in regulating elastogenesis and elastin fiber formation.

Streptavidin-biotin immunotoxins: a new approach to purging bone marrow.

Immunotoxins have been used both experimentally and clinically to purge bone marrow of tumor cells or T cells before transplantation. We describe the synthesis of a streptavidin-biotin-toxin conjugate using whole ricin. Streptavidin-biotin-ricin (SA-BR) conjugates were synthesized by biotinylation of whole ricin, which was then complexed with streptavidin. Hybrid molecules consisting of a single biotinylated ricin moiety linked to a streptavidin molecule were separated by gel filtration. This SA-BR conjugate was used in an indirect cytotoxicity assay. The assay involved sensitizing of target cells with biotinylated monoclonal antibody (B-MCAB) followed by treatment with dilutions of SA-BR conjugate. The assay demonstrated a specific antibody-directed cytotoxicity. The strength of this SA-BR system is that a single conjugate was able to be used in conjunction with a library of B-MCABs to selectively target phenotypically different cell types. The application of the SA-BR conjugate is thus only restricted by the availability of B-MCABs specific for the desired target cells. The high affinity of avidin for biotin (Kd approximately 10(-15)) and the ability of a single conjugate to target phenotypically different cells through utilization of a library of B-MCABs gives SA-BR conjugates great potential in the selective targeting of individual cell types.

Transcriptional activation of deoxyribonucleic acid polymerase alpha gene expression in MCF-7 cells by 17 beta-estradiol.

Treatment of MCF-7 human breast cancer cells with 17beta-estradiol (E(2)) results in increased DNA synthesis and cell proliferation and enhanced enzyme activities associated with purine/pyrimidine biosynthesis. The mechanism of enhanced DNA polymerase alpha activity was investigated by analysis of the promoter region of this gene. E(2) induced luciferase (reporter gene) activity in MCF-7 cells transfected with pDNAP1, pDNAP2, and pDNAP3 containing -1515 to +45, -248 to +45 and -116 to +45 inserts from the DNA polymerase alpha gene promoter, whereas no induction was observed with pDNAP4 (-65 to +45 insert). The induction response was dependent on cotransfection with estrogen receptor alpha (ER(alpha)), and transactivation was also observed with a mutant ER(alpha) that did not express the DNA-binding domain. Subsequent functional, DNA binding, and DNA footprinting studies showed that a GC-rich region at -106 to -100 was required for E(2)-mediated transactivation, and Sp1 protein, but not ER(alpha), bound this sequence. Transcriptional activation of DNA polymerase alpha by E(2) is associated with ER(alpha)/Sp1 action at a proximal GC-rich promoter sequence, and this gene is among a growing list of E(2)-responsive genes that are induced via ER(alpha)/Sp1 protein interactions that do not require direct binding of the hormone receptor to DNA.

Crosstalk between estrogen receptor alpha and the aryl hydrocarbon receptor in breast cancer cells involves unidirectional activation of proteasomes.

2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) is an environmental toxin that activates the aryl hydrocarbon receptor (AhR) and disrupts multiple endocrine signaling pathways. T47D human breast cancer cells express a functional estrogen receptor alpha (ERalpha) and AhR, and treatment of these cells with 17beta-estradiol (E2) or TCDD resulted in a rapid proteasome-dependent decrease in immunoreactive ERalpha and AhR proteins (>60-80%), respectively. E2 did not affect the AhR, whereas TCDD induced proteasome-dependent degradation of both the AhR and ERalpha in T47D and MCF-7 human breast cancer cells, and these responses were specifically blocked by proteasome inhibitors. Thus, TCDD-induced degradation of ERalpha may contribute to the antiestrogenic activity of AhR agonists and this pathway may be involved in AhR-mediated disruption of other endocrine responses.

Differential activation of wild-type and variant forms of estrogen receptor alpha by synthetic and natural estrogenic compounds using a promoter containing three estrogen-responsive elements.

Structure-dependent estrogen receptor alpha (ER alpha) agonist and antagonist activities of synthetic and natural estrogenic compounds were investigated in human HepG2, MDA-MB-231 and U2 cancer cell lines. Compounds used in this study include 4'-hydroxytamoxifen, ICI 182,780, bisphenol-A (BPA), 2',4',6'-trichloro-4-biphenylol (3Cl-PCB-OH), 2',3',4',5'-tetrachloro-4-biphenylol (4Cl-PCB-OH), p-t-octylphenol, p-nonylphenol, naringenin, kepone, resveratrol, and 2,2-bis(p-hydroxyphenyl)-1,1,1-trichloroethane (HPTE). Cells were transfected with a construct (pERE(3)) containing three tandem estrogen responsive elements (EREs) and either wild-type estrogen receptor alpha (ER-wt) or variants expressing activation function-1 (ER-AF1) or AF-2 (ER-AF2). The ER agonist activities of the synthetic mono and dihydroxy aromatic compounds are comparable in all three-cell lines, whereas the activities of naringenin, kepone and resveratrol are dependent on cell context and expression of wild-type or variant forms of ER alpha. In contrast, the ER antagonist activities for these compounds were highly complex and, with the exception of 3Cl-PCB-OH, all compounds inhibited E2-induced wild-type or variant ER action. Results of this in vitro study suggest that the estrogenic and antiestrogenic activity of structurally diverse synthetic and natural estrogenic compounds is complex, and this is consistent with published data that often give contradictory results for these compounds.

False negative hepatitis B surface antigen detection in dialysis patients due to excess surface antigen: postzone phenomenon.

Renal dialysis patients are well known to have a high incidence of hepatitis B carrier state. In studying a group of 63 long-term dialysis patients, 10 were found to be positive for hepatitis B surface antigen by radioimmunoassay (RIA). Surprisingly, however, only three of these RIA positive patients were positive by counter immunoelectrophoresis (CIEP). The discrepancy could not be accounted for by the difference in sensitivity of the two methods. The cause for the negative reactions by CIEP in seven patients was found to be the marked excess surface antigen in these sera which produced false negative results by the postzone phenomenon. After dilution all seven sera were positive by CIEP, requiring a dilution up to 1/20 to produce a positive result. Also, all seven sera were positive by the less sensitive Ouchterlony double diffusion.

Both serotonin and a nitric-oxide donor cause chloride secretion in rat colonocytes by stimulating cGMP.

BACKGROUND: Previous studies have demonstrated that an antagonist of nitric oxide synthase inhibits neurally mediated chloride secretion in response to serotonin (5-HT). The purpose of this study was to demonstrate that chloride secretion in rat colonocytes that were caused by stimulation of neural 5-HT receptors is mediated by way of a nitrergic pathway that involves the activation of guanylate cyclase. METHODS: The nitric oxide (NO) donor, diethylenetriamine/NO (DNO), was added to an enriched suspension of rat colonocytes that were preloaded with (36)Cl(-). In parallel experiments, DNO (1 micromol/L) was added to cells that were pretreated with the specific inhibitor of soluble guanylate cyclase, NS2028 (2 micromol/L). In additional studies, the neural 5-HT(3) receptor agonist, 2-methyl-5-HT (10 micromol/L), was added to the serosal surface of muscle-stripped sheets of rat colonic mucosa that were mounted in Ussing chambers under voltage clamp conditions, both in the absence and presence of NS2028 (20 mircro). RESULTS: DNO induced 18.0% +/- 8.0% greater (36)Cl(-) efflux than controls (P <.05; n = 14 animals). This efflux was abolished by previous treatment with NS2028. In the chamber experiments, 2-methyl-5-HT induced electrogenic chloride secretion that was significantly inhibited by previous treatment with NS2028 (2.2 +/- 0.5 microA/cm(2) vs 13.1 +/- 2.1 microA/cm(2); P <.001; n = 9 animals). CONCLUSIONS: The predominant secretomotor neurotransmitter that mediates the chloride secretory effects of 5-HT in vitro is nitric oxide. Both the secretory effect initiated at the 5-HT(3) receptor on enteric neurons and at the NO(-) receptor on the rat colonocytes are mediated through the activation of intracellular guanylate cyclase and the production of cyclic guanosine monophosphate.

Nitric oxide is a neurotransmitter in the chloride secretory response to serotonin in rat colon.

BACKGROUND: Serotonin (5-hydroxytryptamine [5-HT]) has been shown to induce chloride secretion through a nonadrenergic/noncholinergic neural pathway, mediated by a 5-HT(3) receptor. We hypothesized that 5-HT(3)-induced Cl(-) secretion is ultimately mediated by nitric oxide (NO). METHODS: Unstripped sheets of rat distal colon were mounted in Ussing chambers and short-circuited. The 5-HT(3) receptor agonist, 2-methyl-5-HT, was added in the absence and presence of the NO synthase inhibitor, L-NAME. Companion studies involved the addition of sodium nitroprusside to tissue that was incubated with or without tetrodotoxin. RESULTS: L-NAME caused a significant reduction in the 2-methyl-5-HT-induced change in circuit current, in a concentration-dependent manner. Sodium nitroprusside caused a change in circuit current over baseline in 5 minutes. The addition of tetrodotoxin did not significantly alter the change in circuit current; however, the apical Cl(-) channel blocker, anthracene-9-carboxylic acid, abolished this response. CONCLUSIONS: Neurally mediated Cl(-) secretion in response to 2-methyl-5-HT is inhibited by an NO synthase inhibitor. Exogenous NO mimics this response, which is unaffected by tetrodotoxin. These data suggest that neurally mediated serotoninergic Cl(-) secretion is, in part, mediated by NO. The ability of exogenous NO to induce a change in circuit current in the presence of tetrodotoxin suggests that NO is a final neurotransmitter in this neural-mucosal reflex and therefore acts directly on the enterocyte to induce secretion.

Cloning and expression of the D-ribulose-1,5-bisphosphate carboxylase/oxygenase form II gene from Thiobacillus intermedius in Escherichia coli.

Both form I and II ribulose-1,5-bisphosphate carboxylase/oxygenase (RuBisCO) genes were detected in Thiobacillus intermedius by heterologous hybridization using specific probes from Anacystis nidulans and Rhodobacter sphaeroides, respectively. However, only the previously reported form I enzyme could be demonstrated in cells grown under a number of different conditions. The reason(s) why the form II gene is not expressed in T. intermedius is/are not clear at this time. The form II gene was isolated from a lambda library by screening with the Rb. sphaeroides probe. A SalI fragment from this clone was ligated into pUC8 and transformed into Escherichia coli DH5 alpha. Subclones pTi20IIA and pTi20IIB representing both orientations relative to the lac promoter were isolated. Low levels of RuBisCO activity were detected in both induced and non-induced pTi20IIA indicating the probable expression from a T. intermedius promoter. Induced pTi20IIB produced much higher levels of enzyme activity. Analysis of cell-free extracts using sucrose density gradients confirmed the expression of a form II RuBisCO similar in size to that found in Rhodobacter capsulatus. Other Calvin cycle genes were not clustered with either the form I or form II genes.

Kinetics of growth and ribosome-inactivating protein production from Trichosanthes kirilowii plant cell cultures in a 5-L bioreactor.

Ribosome-inactivating proteins, named for their ability to inhibit protein translation in cell-free systems, are an important class of natural plant defense proteins with potential human therapeutic and agricultural applications. The kinetics of growth, nutrient consumption, and extracellular protein translation inhibitory activity are presented for Trichosanthes kirilowii plant cell suspensions in 5-L bioreactors at two agitation rates (50 and 100 rpm). The cultures had a 7-9.5 day lag phase followed by exponential growth with a doubling time of less than 2 days. Biomass concentrations reached levels of approximately 19 g (dry weight)/L. Protein translation inhibitory activity was observed in the culture broths during the exponential growth phase and reached levels of approximately 50-60 units. No detrimental effects of agitation were observed at 100 rpm. These studies demonstrate the potential for plant cell culture production of ribosome-inactivating proteins in bioreactor systems.

Residua of Guillain-Barré Polyneuritis in Children.

A study of the records from the period 1950 to 1970 at the Elizabethtown Hospital for Children and Youth produced twelve patients with the Guillain-Barré syndrome. These patients were contracted in 1975-76 and each was personally examined. Ten were found to have residual weakness but in several instances the weakness was so mild the patient was unaware of it. Good correlations were found between muscle examinations during the acute recovery period and at final follow-up. Six patients had undergone various surgical procedures, and all of them thought they had benefited.

Intestinal perforation secondary to Salmonella typhi: case report and review of the literature.

The case of a young woman presenting with fever, abdominal distention, and diarrhea is presented. While hospitalized, she developed peritonitis, and a laparotomy was performed emergently. Intraoperative and pathologic examinations are highly suggestive of Salmonella typhi as an etiology for her symptoms and eventual perforation. Salmonella enteritis can be a difficult diagnosis to make, but in most cases it is a self-limited disease process. In a minority of cases, multidrug antibiotic therapy may be required secondary to an increasing prevalence of resistant strains. Patients who perforate require prompt operation to limit morbidity and mortality. Outcome is significantly improved in those patients by directed resection of the affected segment of bowel and by aggressive perioperative care.

Systemic factors influencing the growth of cultured epithelial autograft.

This is a retrospective study of 23 consecutive patients who had biopsies taken for cultured epidermal autograft between February 1993 and September 1994. Keratinocyte cultures were initiated on all of these biopsies. Of these 23 biopsies, it was noted that the cells obtained from three patients grew particularly slowly or failed to grow at all. Taking into account that the biopsy and culture conditions were standard for all patients, we investigated whether the patient's previous medical history may have had any effect on the ability of the cells to be cultured in vitro. Our results indicated that the keratinocyte cultures of patients with a significant past medical history, and particularly those with underlying pathology affecting their general physical condition, have a decreased growth rate. This raises the question that general patient condition can possibly influence the clinical use of the technique.

Implication of basement membrane development on the underlying scar in partial-thickness burn injury.

There is increasing evidence from the scientific literature that the developing epithelial basement membrane has the potential to influence the underlying dermis. The most rapidly dividing and active cell within the skin complex is the basal cell of the epidermis. The basal cell is well known to produce numerous protein factors which influence cellular growth and differentiation. The underlying dermal fibroblasts, by comparison, are relatively static. The concept that basal cells have an influence on the dermal and overall skin environment via the extracellular expression of proteins in the extracellular matrix, is gaining increased interest. A hypertrophic scar is a dermal phenomenon resulting from an imbalance in collagen production and maturation. Although the collagen is produced by the fibroblast, the extracellular matrix is an area where the epidermal cells have a potential influence. It is therefore the purpose of this paper to explore the idea that the cultured epithelial autograft may have an influence on the quality of scarring.

Tunneled catheter thrombosis: factors related to incidence.

Quasi-experimental and descriptive methods were used to investigate thrombosis incidence in 294 tunneled central venous catheters inserted in adult clients with cancer. Thrombosis incidence was measured in relation to heparin flush regimen, internal catheter tip location, and chemotherapy infusate volume. Data were collected for two cohorts: 1) 145 tunneled catheters using 5 ml daily of 10 U/ml heparin flush, and 2) 51 catheters using 10 cc daily of 100 U/ml heparin flush. Data were also collected for an additional 98 catheters (transitional) utilizing a combination of flush #1 and #2 from adjacent time periods. Chi square analysis of the cohorts revealed no difference in thrombosis incidence by flush regimen or chemotherapy infusate volume. Suboptimal internal catheter tip location and catheters placed on the left side were related to higher thrombosis incidence. Practice implications include: the need for staff and patient education regarding signs and symptoms of catheter-related thrombosis, additional systematic data collection and evaluation, and support for empirical research to establish optimal vascular access device care.

The treatment of hypopigmented lesions with cultured epithelial autograft.

Hypopigmentation may be a significant problem after burn injury. It is often difficult to predictably repair with conventional surgical techniques. It has been our experience that epidermal cells cultured from patients with dark skin produce pigment within the epidermal cell sheets, which indicates the presence of melanocytes. The presence of melanocytes and melanin in these cell sheets was demonstrated with the use of histochemical techniques. The results indicate that repigmentation with cultured epithelial autograft is possible. We describe a novel technique of dermabrasion and a co-culture of epidermal cells and melanocytes.

Sprayed keratinocyte suspensions accelerate epidermal coverage in a porcine microwound model.

Keratinocyte suspensions can potentially treat a variety of epidermal defects, but the mechanism of action has not been fully determined. We developed a porcine model to study the effect of sprayed cell suspensions delivered on small wounds within a meshed autograft. Paired full-thickness surgically excised wounds were covered with a fully expanded 3:1 meshed split-thickness autograft. A keratinocyte cell suspension was sprayed onto half of the wounds at a seeding density of 2.8 x 10(3) cells/cm2; the remaining wounds were sprayed with cell culture medium alone. Histologic analysis at days 5 and 8 showed an increase in average epidermal thickness, confluence, keratin cysts, and blood vessels in the keratinocyte cell suspension group compared with the cell culture medium control group. Wounds sprayed with the cell suspension showed faster and better quality of epithelialization than wounds sprayed with cell culture medium alone.

Melanocyte repopulation in full-thickness wounds using a cell spray apparatus.

Melanocyte restoration is critical in reconstituting skin color. We developed a spotted (piebald) pig wound model to study methods of restoring melanocytes to the epidermis. Paired, full-thickness, porcine wounds were covered with nonpigmented, fully expanded, 3:1 meshed, split-thickness skin grafts and were sprayed with an epidermal cell suspension. The suspensions were highly pigmented skin (HPS) cell isolates for half of the wounds (n = 16) and nonpigmented skin (NPS) cell isolates for the remaining wounds (n = 16). Histologic sections showed 6.0 +/- 3.0 and 15 +/- 4.0 pigmented melanocytes per high-power field on days 8 and 20 in HPS-treated wounds and no pigmented melanocytes in NPS-treated wounds. Melanin pigment was dispersed in all layers of the epithelium for the HPS group on day 20 compared with a lack of melanin pigment observed in the NPS group. Cell spraying may provide a clinical method to restore color to skin; further work is needed to control the expression of melanin.

A retrospective study of patient falls in a psychiatric hospital.

1. While falls on medical-surgical units are the focus of extensive research, falls on inpatient psychiatric units are an understudied critical event. 2. The purposes of this study were to identify the variables associated with psychiatric patient falls and to use that information to assess risk and, therefore, prevent falls in this population. 3. The psychiatric patient at risk for falling is described as a woman with a prior history of falls; less than 65 years of age; experiencing anxiety and agitation; and receiving a sedative, a tranquilizer, and a laxative. Additionally, this patient is more likely to fall in a community area.