Comparison of hand hygiene evaluations: A literature review

Background. Because our hands are the most common mode of transmission for bacteria causing hospital acquired infections, hand hygiene practices are the most effective method of preventing the spread of these pathogens, limiting the occurrence of healthcare-associated infections and reducing transmission of multi-drug resistant organisms. Yet, compliance rates are below 40% on the average. ^ Objective. This culminating experience project is primarily a literature review on hand hygiene to help determine the barriers to hand hygiene compliance and offer solutions on improving these rates and to build on a hand hygiene evaluation performed during my infection control internship completed at Memorial Hermann Hospital during the fall semester of 2005. ^ Method. A review of peer-reviewed literature using Ovid Medline, Ebsco Medline and PubMed databases using keywords: hand hygiene, hand hygiene compliance, alcohol based handrub, healthcare-associated infections, hospital-acquired infections, and infection control. ^ Results. A total of eight hand hygiene studies are highlighted. At a children's hospital in Seattle, hand hygiene compliance rates increases from 62% to 81% after five periods of interventions. In Thailand, 26 nurses dramatically increased compliance from 6.3% to 81.2% after just 7 months of training. Automated alcohol based handrub dispensers improved compliance rates in Chicago from 36.3% to 70.1%. Using education and increased distribution of alcohol based handrubs increased hand hygiene rates from 59% to 79% for Ebnother, from 54% to 85% for Hussein and from 32% to 63% for Randle. Spartanburg Regional Medical Center increased their rates from 72.5% to 90.3%. A level III NICU achieved 100% compliance after a month long educational campaign but fell back down to its baseline rate of 89% after 3 months. ^ Discussion. The interventions used to promote hand hygiene in the highlighted studies varied from low tech approaches such as printed materials to advanced electronic gadgets that alerted individuals automatically to perform hand hygiene. All approaches were effective and increased compliance rates. Overcoming hand hygiene barriers, receiving and accepting feedback is the key to maintaining consistently high hand hygiene adherence. ^

Early stage breast cancer and comorbidities: Their impact on breast cancer disease-free survival differences by ethnicity

The retrospective cohort study examined the association between the presence of comorbidities and breast cancer disease-free survival rates among racial/ethnic groups. The study population consisted of 2389 women with stage I and II invasive breast cancer who were diagnosed and treated at the M.D. Anderson Cancer Center between 1985 and 2000. It has been suggested that as the number of comorbidities increases, breast cancer mortality increases. It is known that African Americans and Hispanics are considered to be at a higher risk for comorbid conditions such as hypertension and diabetes compared to Caucasian women (23) (10). When compared to Caucasian women, African American women also have a higher breast cancer mortality rate (1). As a result, the study also examined whether comorbid conditions contribute to racial differences in breast cancer disease-free survival. Among the study population, 24% suffered from breast cancer recurrence, 6% died from breast cancer and 24% died from all causes. The mean age was 56 with 41% of the population being women between the ages of 40-55. One or more comorbidities were reported in 84 (36%) African Americans (OR 1.57; 95% CI 1.19-2.10), 58 (31%) Hispanics (OR 1.25; 95% CI 0.90-1.74) compared to the reference group of 531 (27%) Caucasians. Additionally, African American women were significantly more likely to suffer from either a breast cancer recurrence or breast cancer death (OR 1.5; 95% CI 0.70-1.41) when compared to Caucasian women. Multivariate analysis found hypertension (HR 1.22; 95% CI 0.99-1.49; p<0.05) to be statistically significant and a potential prognostic tool for disease-free survival with African American women (OR 2.96; 95% 2.25-3.90) more likely to suffer from hypertension when compared to Caucasian women. When compared to Caucasian women, Hispanics were also more likely to suffer from hypertension (OR 1.33; 95% CI 0.96-1.83). This suggests that comorbid conditions like hypertension could account for the racial disparities that exist when comparing breast cancer survival rates. Future studies should investigate this relationship further.^

Maximal exercise hemodynamics and risk of mortality in apparently healthy men and women

The use of exercise electrocardiography (ECG) to detect latent coronary heart disease (CHD) is discouraged in apparently healthy populations because of low sensitivity. These recommendations however, are based on the efficacy of evaluation of ischemia (ST segment changes) with little regard for other measures of cardiac function that are available during exertion. The purpose of this investigation was to determine the association of maximal exercise hemodynamic responses with risk of mortality due to all-causes, cardiovascular disease (CVD), and coronary heart disease (CHD) in apparently healthy individuals. Study participants were 20,387 men (mean age = 42.2 years) and 6,234 women (mean age = 41.9 years) patients of a preventive medicine center in Dallas, TX examined between 1971 and 1989. During an average of 8.1 years of follow-up, there were 348 deaths in men and 66 deaths in women. In men, age-adjusted all-cause death rates (per 10,000 person years) across quartiles of maximal systolic blood pressure (SBP) (low to high) were: 18.2, 16.2, 23.8, and 24.6 (p for trend $<$0.001). Corresponding rates for maximal heart rate were: 28.9, 15.9, 18.4, and 15.1 (p trend $<$0.001). After adjustment for confounding variables including age, resting systolic pressure, serum cholesterol and glucose, body mass index, smoking status, physical fitness and family history of CVD, risks (and 95% confidence interval (CI)) of all-cause mortality for quartiles of maximal SBP, relative to the lowest quartile, were: 0.96 (0.70-1.33), 1.36 (1.01-1.85), and 1.37 (0.98-1.92) for quartiles 2-4 respectively. Similar risks for maximal heart rate were: 0.61 (0.44-0.85), 0.69 (0.51-0.93), and 0.60 (0.41-0.87). No associations were noted between maximal exercise rate-pressure product mortality. Similar results were seen for risk of CVD and CHD death. In women, similar trends in age-adjusted all-cause and CVD death rates across maximal SBP and heart rate categories were observed. Sensitivity of the exercise test in predicting mortality was enhanced when ECG results were evaluated together with maximal exercise SBP or heart rate with a concomitant decrease in specificity. Positive predictive values were not improved. The efficacy of the exercise test in predicting mortality in apparently healthy men and women was not enhanced by using maximal exercise hemodynamic responses. These results suggest that an exaggerated systolic blood pressure or an attenuated heart rate response to maximal exercise are risk factors for mortality in apparently healthy individuals. ^

The role of conserved region 1 of Escherichia coli sigma-70 in transcription initiation

The sigma (σ) subunit of eubacterial RNA polymerase is essential for initiation of transcription at promoter sites. σ factor directs the RNA polymerase core subunits ( a2bb′ ) to the promoter consensus elements and thereby confers selectivity for transcription initiation. The N-terminal domain (region 1.1) of Escherichia coli σ70 has been shown to inhibit DNA binding by the C-terminal DNA recognition domains when σ is separated from the core subunits. Since DNA recognition by RNA polymerase is the first step in transcription, it seemed plausible that region 1 might also influence initiation processes subsesquent to DNA binding. This study explores the functional roles of regions 1.1 and 1.2 of σ70 in transcription initiation. Analysis in vitro of the transcriptional properties of a series of N-terminally truncated σ70 derivates revealed a critical role for region 1.1 at several key stages of initiation. Deletion of the first 75 to 100 amino acids of σ70 (region 1.1) resulted in both a slow rate of transition from a closed promoter complex to a DNA-strand-separated open complex, as well as a reduced efficiency of transition from the open complex to a transcriptionally active open complex. These effects were partially reversed by addition of a polypeptide containing region 1.1 in trans. Therefore, region 1.1 not only modulates DNA binding but is important for efficient transcription initiation, once a closed complex has formed. A deletion of the first 133 amino acids which removes both regions 1.1 and 1.2 resulted in arrest of initiation at the earliest closed complex, suggesting that region 1.2 is required for open complex formation. Mutagenesis of region 1.1 uncovered a mechanistically important role for isoleucine at position 53 (I53). Substitution of I53 with alanine created a σ factor that associated with the core subunits to form holoenzyme, but the holoenzyme was severely deficient for promoter binding. The I53A phenotype was suppressed in vivo by truncation of five amino acids from the C-terminus of σ 70. These observations are consistent with a model in which σ 70I53A fails to undergo a critical conformational change upon association with the core subunits, which is needed to expose the DNA-binding domains and confer promoter recognition capability upon holoenzyme. To understand the basis of the autoinhibitory properties of the σ70 N-terminal domain, in the absence of core RNA polymerase, a preliminary physical assessment of the interdomain interactions within the σ70 subunit was launched. Results support a model in which N-terminal amino acids are in close proximity to residues in the C-terminus of the σ 70 polypeptide. ^

An analysis of the function of region 1.2 of the primary sigma factor, sigma 70, from Escherichia coli

The sigma (σ) subunit of eubacterial RNA polymerase is required for recognition of and transcription initiation from promoter DNA sequences. One family of sigma factors includes those related to the primary sigma factor from E. coli, σ70. Members of the σ70 family have four highly conserved domains, of which regions 2 through 4 are present in all members. Region 1 can be subdivided into regions 1.1 and 1.2. Region 1.1 affects DNA binding by σ 70 alone, as well as transcription initiation by holoenzyme. Region 1.2, present and highly conserved in most sigma factors, has not yet been assigned a putative function, although previous work demonstrated that it is not required for either association with the core subunits of RNA polymerase or promoter specific binding by holoenzyme. This study primarily investigates the functional role of region 1.2 during transcription initiation. In vivo and in vitro characterization of thirty-two single amino acid substitutions targeted to region 1.2 of E. coli σ70 as well as a deletion of region 1.2, revealed that mutations in region 1.2 can affect promoter binding, open complex formation, initiated complex formation, and the transition from abortive transcription to elongation. The relative degree of solvent exposure of several positions in region 1.2 has been determined, with positions 116 and 122 likely to be located near the surface of σ70. ^ During the course of this study, the existence of two “wild type” variants of E. coli σ70 was discovered. The identity of amino acid 149 has been reported variably as either arginine or aspartic acid in published articles and in online databases. In vivo and in vitro characterization of the two reported variations of E. coli σ70 (N149 and D149) has determined that the two variants are functionally equivalent. However, in vivo and in vitro characterization of single amino acid substitutions and a region 1.2 deletion in the context of each variant background revealed that the behavior of some mutations are greatly affected by the identity of amino acid 149. ^

CREB trans-activation of disruptor of telomeric silencing-1 mediates forskolin inhibition of CTGF transcription in mesangial cells.

Connective tissue growth factor (CTGF) participates in diverse fibrotic processes including glomerulosclerosis. The adenylyl cyclase agonist forskolin inhibits CTGF expression in mesangial cells by unclear mechanisms. We recently reported that the histone H3K79 methyltransferase disruptor of telomeric silencing-1 (Dot1) suppresses CTGF gene expression in collecting duct cells (J Clin Invest 117: 773-783, 2007) and HEK 293 cells (J Biol Chem In press). In the present study, we characterized the involvement of Dot1 in mediating the inhibitory effect of forskolin on CTGF transcription in mouse mesangial cells. Overexpression of Dot1 or treatment with forskolin dramatically suppressed basal CTGF mRNA levels and CTGF promoter-luciferase activity, while hypermethylating H3K79 in chromatin associated with the CTGF promoter. siRNA knockdown of Dot1 abrogated the inhibitory effect of forskolin on CTGF mRNA expression. Analysis of the Dot1 promoter sequence identified a CREB response element (CRE) at -384/-380. Overexpression of CREB enhanced forskolin-stimulated Dot1 promoter activity. A constitutively active CREB mutant (CREB-VP16) strongly induced Dot1 promoter-luciferase activity, whereas overexpression of CREBdLZ-VP16, which lacks the CREB DNA-binding domain, abolished this activation. Mutation of the -384/-380 CRE resulted in 70% lower levels of Dot1 promoter activity. ChIP assays confirmed CREB binding to the Dot1 promoter in chromatin. We conclude that forskolin stimulates CREB-mediated trans-activation of the Dot1 gene, which leads to hypermethylation of histone H3K79 at the CTGF promoter, and inhibition of CTGF transcription. These data are the first to describe regulation of the Dot1 gene, and disclose a complex network of genetic and epigenetic controls on CTGF transcription.

Ketamine-induced hepatoprotection: the role of heme oxygenase-1.

Lipopolysaccharide (LPS) causes hepatic injury that is mediated, in part, by upregulation of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2). Ketamine has been shown to prevent these effects. Because upregulation of heme oxygenase-1 (HO-1) has hepatoprotective effects, as does carbon monoxide (CO), an end product of the HO-1 catalytic reaction, we examined the effects of HO-1 inhibition on ketamine-induced hepatoprotection and assessed whether CO could attenuate LPS-induced hepatic injury. One group of rats received ketamine (70 mg/kg ip) or saline concurrently with either the HO-1 inhibitor tin protoporphyrin IX (50 micromol/kg ip) or saline. Another group of rats received inhalational CO (250 ppm over 1 h) or room air. All rats were given LPS (20 mg/kg ip) or saline 1 h later and euthanized 5 h after LPS or saline. Liver was collected for iNOS, COX-2, and HO-1 (Western blot), NF-kappaB and PPAR-gamma analysis (EMSA), and iNOS and COX-2 mRNA analysis (RT-PCR). Serum was collected to measure alanine aminotransferase as an index of hepatocellular injury. HO-1 inhibition attenuated ketamine-induced hepatoprotection and downregulation of iNOS and COX-2 protein. CO prevented LPS-induced hepatic injury and upregulation of iNOS and COX-2 proteins. Although CO abolished the ability of LPS to diminish PPAR-gamma activity, it enhanced NF-kappaB activity. These data suggest that the hepatoprotective effects of ketamine are mediated primarily by HO-1 and its end product CO.

THE ROLE OF RECEPTOR TYROSINE KINASE AXL IN PANCREATIC DUCTAL ADENOCARCINOMA AND ITS REGULATION BY HEMATOPOIETIC PROGENITOR KINASE 1

Pancreatic ductal adenocarcinoma (PDA) is one of the most aggressive malignancies with less than 5% of five year survival rate. New molecular markers and new therapeutic targets are urgently needed for patients with PDA. Oncogenic receptor tyrosine kinase Axl has been reported to be overexpressed in many types of human malignancies, including diffuse glioma, melanoma, osteosarcoma, and carcinomas of lung, colon, prostate, breast, ovary, esophagus, stomach, and kidney. However, the expression and functions of Axl in PDA are unclear. We hypothesized that Axl contributes to the development and progression of PDA. We examined Axl expression in 54 human PDA samples and their paired benign pancreatic tissue by immunohistochemistry, we found that Axl was overexpressed in 70% of stage II PDAs, but only 22% of benign ducts (P=0.0001). Axl overexpression was associated with higher frequencies of distant metastasis and was an independent prognostic factor for both poor overall and recurrence-free survivals in patients with stage II PDA (p = 0.03 and 0.04). Axl silencing by shRNA in pancreatic cancer cell lines, panc-28 and Panc-1, decreased tumor cell migration and invasion and sensitized PDA cells to apoptosis stimuli such as γ-irradiation and serum starvation. In addition, we found that Axl-mediated Akt and NF-κB activation and up regulation of MMP2 were involved in the invasion, migration and survival of PDA cells. Thus, we demonstrate that Axl plays an important role in the development and progression of PDA. Targeting Axl signaling pathway may represent a new approach for the treatment of PDA. To understand the molecular mechanisms of Axl overexpression in PDA, we found that Axl expression was down-regulated by hematopoietic progenitor kinase 1 (HPK1), a newly identified tumor suppressor in PDA. HPK1 is lost in over 95% of PDAs. Restoration of HPK1 in PDA cells down-regulated Axl expression. HPK1-mediated Axl degradation was inhibited by leupeptin, baflomycin A1, and monensin, suggesting that HPK1-mediated Axl degradation was through endocytosis-lysosome pathway. HPK1 interacted with and phosphorylated dynamin, a critical component of endocytosis pathway. Overexpression of dominant negative form of dynamin blocked the HPK1-mediated Axl degradation. Therefore we concluded that HPK1-mediated Axl degradation was through endocytosis-lysosome pathway and loss of HPK1 expression may contribute to Axl overexpression in PDAs.

Population and molecular evolution studies on the Melanocortin 1 receptor locus implicate its role in human pigmentation variation

Human pigmentation is a complex trait with the observed variation caused by the varied production of eumelanin (brown/black melanins) and phaeomelanin (red/yellow melanins) by the melanocytes. The melanocortin 1 receptor (MC1R), a G protein-coupled receptor expressed in the melanocytes, is a regulator eu- and phaeomelanin synthesis, and MC1R mutations causing skin and coat color changes are known in many mammals. To understand the role of MC1R in human pigmentation variation, I have sequenced the MC1R gene in 121 individuals sampled from world populations. In addition, I have sequenced the MC1R gene in common and pygmy chimpanzees, gorilla, orangutan, and baboon to study the evolution of MC1R and to infer the ancestral human MC1R sequence. The ancestral MC1R sequence is observed in all 25 African individuals studied, but at lower frequencies in the other populations examined, especially in East and Southeast Asians. The Arg163Gln variant is absent in the Africans studied, almost absent in Europeans, and at a low frequency in Indians, but is at an exceptionally high frequency (70%) in East and Southeast Asians. To further evaluate the role of MC1R variants in human pigmentation variation, I have combined these molecular evolution and population studies with functional assays on MC1R variants and primate MC1Rs. ^

The role of chronic irritation and inflammation in tumor promotion in CD-1 mice by petroleum middle distillates

An initiation-promotion bioassay in CD-1 mice was used to examine the role of chronic irritation and inflammation in tumor promotion by petroleum middle distillates. A representative hydrodesulfurized middle distillate (API 81-07) was selected as the test article. Test groups (54 mice per group) were initiated once with 50 ug of 7,12-dimethylbenzanthracene (DMBA). Promotion with API 81-07 consisted of twice weekly treatments for 25 weeks with either 25 ul, 50 ul, 50 ul + daily treatment with 15 ug dexamethasone, 50 ul + post-application washings, and 100 ul. Three mice from each group were sacrificed at 21 day intervals (24 total per group). The skin from interim sacrificed (IS) mice was examined histopathologically for tumor, acanthosis, hyperkeratosis, pseudo-epitheliomatous hyperplasia, epidermal crusting, and subacute inflammation. In-life observations included examination of all mice for erythema and edema for 8 weeks following the first promotion treatment. Tumor incident at study termination was as follows: 25 ul (45%), 50 ul (43%), 50 ul + dexamethasone (0%), 50 ul + washing (70%), and 100 ul (81%). An overall correlation of $>$0.90 between tumor incidence and group means for acanthosis and hyperkeratosis was observed in IS mice at all intervals. Correlations of $<$0.75 were observed for other group mean histopathological parameters and tumor incidence. The overall correlation of group mean erythema and edema with tumor incident was $>$0.90. The results of this study support the hypothesis that induction of a lasting, albeit mild, hyperplasia is an essential, but not sufficient requirement, for tumor promotion. Furthermore, subacute inflammation does not appear to be a significant factor in tumor promotion by petroleum middle distillates. However, inflammation may be a factor in tumor progression. ^