Secreted amyloid beta-protein similar to that in the senile plaques of Alzheimer's disease is increased in vivo by the presenilin 1 and 2 and APP mutations linked to familial Alzheimer's disease

To determine whether the presenilin 1 (PS1), presenilin 2 (PS2) and amyloid beta-protein precursor (APP) mutations linked to familial Alzheimer's disease (FAD) increase the extracellular concentration of amyloid beta-protein (A beta) ending at A beta 42(43) in vivo, we performed a blinded comparison of plasma A beta levels in carriers of these mutations and controls. A beta 1-42(43) was elevated in plasma from subjects with FAD-linked PS1 (P < 0.0001), PS2N1411 (P = 0.009), APPK670N,M671L (P < 0.0001), and APPV7171 (one subject) mutations. A beta ending at A beta 42(43) was also significantly elevated in fibroblast media from subjects with PS1 (P < 0.0001) or PS2 (P = 0.03) mutations. These findings indicate that the FAD-linked mutations may all cause Alzhelmer's disease by increasing the extracellular concentration of A beta 42(43), thereby fostering cerebral deposition of this highly amyloidogenic peptide.

The Cognitive Abilities Screening Instrument (CASI): a practical test for cross-cultural epidemiological studies of dementia

The Cognitive Abilities Screening Instrument (CASI) has a score range of 0 to 100 and provides quantitative assessment on attention, concentration, orientation, short-term memory, long-term memory, language abilities, visual construction, list-generating fluency, abstraction, and judgment. Scores of the Mini-Mental State Examination, the Modified Mini-Mental State Test, and the Hasegawa Dementia Screening Scale can also be estimated from subsets of the CASI items. Pilot testing conducted in Japan and in the United States has demonstrated its cross-cultural applicability and its usefulness in screening for dementia, in monitoring disease progression, and in providing profiles of cognitive impairment. Typical administration time is 15 to 20 minutes. Record form, manual, videotape of test administration, and quizzes to qualify potential users on the administration and scoring of the CASI are available upon request.

‘My five moments for hand hygiene’: a user-centred design approach to understand, train, monitor and report hand hygiene

Hand hygiene is a core element of patient safety for the prevention of healthcare-associated infections and the spread of antimicrobial resistance. Its promotion represents a challenge that requires a multi-modal strategy using a clear, robust and simple conceptual framework. The World Health Organization First Global Patient Safety Challenge 'Clean Care is Safer Care' has expanded educational and promotional tools developed initially for the Swiss national hand hygiene campaign for worldwide use. Development methodology involved a user-centred design approach incorporating strategies of human factors engineering, cognitive behaviour science and elements of social marketing, followed by an iterative prototype test phase within the target population. This research resulted in a concept called 'My five moments for hand hygiene'. It describes the fundamental reference points for healthcare workers (HCWs) in a time-space framework and designates the moments when hand hygiene is required to effectively interrupt microbial transmission during the care sequence. The concept applies to a wide range of patient care activities and healthcare settings. It proposes a unified vision for trainers, observers and HCWs that should facilitate education, minimize inter-individual variation and resource use, and increase adherence. 'My five moments for hand hygiene' bridges the gap between scientific evidence and daily health practice and provides a solid basis to understand, teach, monitor and report hand hygiene practices.

Understanding adherence to hand hygiene recommendations: the theory of planned behavior

BACKGROUND

Most health care workers (HCWs) are aware of the rationale for hand hygiene procedures, yet failure to adhere to guidelines is common. Little is known about factors that motivate HCWs to practice hand hygiene.

PURPOSE

The purposes of this study were to (1) estimate adherence to hand hygiene recommendations; (2) describe relationships among motivational factors, adherence, and intensity of nursing unit activity; and (3) test an explanatory model for adherence to hand hygiene guidelines based on the theory of planned behavior (TPB).

METHOD

A longitudinal, observational design was used to collect data from 120 registered nurses employed in critical care and postcritical care units. Nurses provided information about motivational factors and intentions and a self-report of the proportion of time they followed guidelines. At least 2 weeks later, the nurses' hand hygiene performance was observed while they provided patient care. Structural equation modeling was used to test the TPB-based model.

RESULTS

Rate of adherence to recommendations for 1248 hand hygiene indications was 70%. The correlation between self-reported and observed adherence to handwashing recommendations was low (r = 0.21). TPB variables predicted intention to handwash, and intention was related to self-reported hand hygiene. Intensity of activity in the nursing unit, rather than TPB variables, predicted observed adherence to hand hygiene recommendations.

CONCLUSIONS

The limited association between self-reported and observed hand hygiene scores remains an enigma to be explained. Actual hand hygiene behavior may be more sensitive to the intensity of work activity in the clinical setting than to internal motivational factors.

Coexistence of cognitive impairment and depression in geriatric outpatients

The authors diagnosed depression in 20 (23%) of 88 cognitively impaired geriatric outpatients. Three (20%) of these patients had depression only, and 17 (85%) had depression superimposed on an underlying dementia. The rate of coexisting depression decreased significantly with greater severity of the cognitive impairment: 9 (33%) of 27 mildly impaired patients were depressed, compared with 8 (23%) of 35 moderately impaired and 3 (12%) of 26 severely impaired patients. There was a nonsignificant trend for cognitively impaired women to be more likely to be depressed than for similarly impaired men. The authors conclude that although depression must be differentiated from dementia, it is equally important to consider the possibility that the diagnoses coexist.

Artificial reductant enhancement of the Lowry method for protein determination

Addition of dithiothreitol in the Lowry procedure 3 min after adding the Folin-Ciocalteau reagent produces immediate color development, with 35 to 60% greater absorbance per mass of protein used.

Behavioural considerations for hand hygiene practices: the basic building blocks

Hand hygiene is considered to be the most effective measure to prevent microbial pathogen cross-transmission and healthcare-associated infections. In October 2005, the World Health Organization (WHO) World Alliance for Patient Safety launched the first Global Patient Safety Challenge 2005-2006, 'Clean Care is Safer Care', to tackle healthcare-associated infection on a large scale. Within the Challenge framework, international infection control experts and consultative taskforces met to develop new WHO Guidelines on Hand Hygiene in Healthcare. The taskforce was asked to explore aspects underlying hand hygiene behaviour that may influence its promotion among healthcare workers. The dynamics of behavioural change are complex and multi-faceted, but are of vital importance when designing a strategy to improve hand hygiene compliance. A reflection on challenges to be met and areas for future research are also proposed.

Skin hygiene and infection prevention: more of the same or different approaches?

The purpose of this article is to review research indicating a link between hand hygiene and nosocomial infections and the effects of hand care practices on skin integrity and to make recommendations for potential changes in clinical practice and for further research regarding hand hygiene practices. Despite some methodological flaws and data gaps, evidence for a causal relationship between hand hygiene and reduced transmission of infections is convincing, but frequent handwashing causes skin damage, with resultant changes in microbial flora, increased skin shedding, and risk of transmission of microorganisms, suggesting that some traditional hand hygiene practices warrant reexamination. Some recommended changes in practice include use of waterless alcohol-based products rather than detergent-based antiseptics, modifications in lengthy surgical scrub protocols, and incorporation of moisturizers into skin care regimens of health care professionals.

Guideline for use of topical antimicrobial agents

This Guideline is based on published data available at the time of writing. The ideal means for comparing performance of various antimicrobial agents is through the conduct of carefully designed, large-scale clinical trials. Recommendations contained in this Guideline are subject to modification as additional data become available. It particularly should be noted that the implementation of universal precautions or body substance isolation has resulted in marked increase in the use of gloves for direct patient contact. Whether there is an additional cost-benefit rationale for handwashing with an antimicrobial agent remains to be studied.

Factors influencing handwashing behavior of patient care personnel

Factors that are important in influencing individuals to wash or not wash their hands were studied in 193 health care personnel. The most important factor favoring handwashing (HW) was the prevention of spread of infection among patients; the most important factor against HW was busy-ness. Physicians reported HW significantly less frequently than did nurses (p = 0.04). Individuals who washed infrequently, less than eight times per day, placed significantly more value on detrimental effects of frequent HW on their own skin and on the HW practices of their work colleagues than did individuals who washed frequently, more than 16 times per day (p less than 0.005). Frequent and infrequent washers did not differ significantly in their values regarding the factors favoring HW. Identifying factors that are determinants of whether one decides to wash one's hands or not are important in planning intervention strategies to improve practice. It appears that more emphasis should be placed on minimizing deterrents (especially detrimental effects on skin and peer pressure) rather than on emphasizing the importance of HW.

Compliance with handwashing and barrier precautions

Compliance with handwashing and barrier precautions remains suboptimal in all health care settings and among all types of staff. Interventions to increase compliance include educational and motivational programmes, providing individual and group feedback on performance, modifying and improving equipment available, changing administrative policy and sanctions, and increasing staff commitment with role modelling. Single, isolated interventions are unlikely to meet with sustained success. A theory-based, multifaceted approach is indicated.

DNA bending and unbending by MutS govern mismatch recognition and specificity

DNA mismatch repair is central to the maintenance of genomic stability. It is initiated by the recognition of base-base mismatches and insertion/deletion loops by the family of MutS proteins. Subsequently, ATP induces a unique conformational change in the MutS-mismatch complex but not in the MutS-homoduplex complex that sets off the cascade of events that leads to repair. To gain insight into the mechanism by which MutS discriminates between mismatch and homoduplex DNA, we have examined the conformations of specific and nonspecific MutS-DNA complexes by using atomic force microscopy. Interestingly, MutS-DNA complexes exhibit a single population of conformations, in which the DNA is bent at homoduplex sites, but two populations of conformations, bent and unbent, at mismatch sites. These results suggest that the specific recognition complex is one in which the DNA is unbent. Combining our results with existing biochemical and crystallographic data leads us to propose that MutS: (i) binds to DNA nonspecifically and bends it in search of a mismatch; (ii) on specific recognition of a mismatch, undergoes a conformational change to an initial recognition complex in which the DNA is kinked, with interactions similar to those in the published crystal structures; and (iii) finally undergoes a further conformational change to the ultimate recognition complex in which the DNA is unbent. Our results provide a structural explanation for the long-standing question of how MutS achieves mismatch repair specificity.

Dementia of the Alzheimer's type and depression

This retrospective review of medical records was designed to address three questions: 1) Can the depression seen in some patients with Dementia of the Alzheimer's Type (DAT) be successfully treated? 2) Does this treatment lead to any long-term improvement in the patient's cognitive status? and 3) Do patients with coexisting DAT and depression have a different long-term clinical course than nondepressed DAT patients? In the authors' sample of 131 DAT subjects, 41 (31%) also met DMS-III criteria for a major affective disorder. Of those DAT plus depression patients whose records reflected treatment (usually with a tricyclic antidepressant), 85% (17 of 20) showed clear evidence of improvement in mood, vegetative signs, or activities of daily living (ADLs) based on review of the medical record. An analysis of change in cognitive function (measured by the Folstein Mini-Mental State) and five global measures failed to reveal any differences between the depressed and nondepressed groups after a mean interval of 17 months. The depression that occurs in approximately one-quarter to one-third of DAT patients appears to respond to appropriate therapy. These patients often show improvement in their mood and ADLs but remain demented.

MutSalpha binds to and promotes synapsis of transcriptionally activated immunoglobulin switch regions

Immunoglobulin class switch recombination joins a new constant (C) region to the rearranged and expressed heavy chain variable (VDJ) region in antigen-activated B cells (Figure 1A) (reviewed in [1, 2]). Switch recombination is activated by transcription of intronic, G-rich and repetitive switch (S) regions and produces junctions that are heterogeneous in sequence and position in the S regions. Switch recombination depends upon the B cell-specific cytidine deaminase, AID, and conserved DNA repair factors, including the mismatch repair heterodimer, MutSalpha (MSH2/MSH6). In mice, ablation of Msh2 or Msh6, but not Msh3, decreases levels of switch recombination and diminishes heterogeneity of switch junctions [3-7]. Here, we demonstrate that MSH2 associates with transcribed S regions in primary murine B cells activated for switch recombination. Electron microscopic imaging reveals that MutSalpha binds in vitro to DNA structures formed within transcribed S regions and mediates their synapsis. MutSalpha binds with high affinity to G4 DNA formed upon transcription of the S regions and also binds to U.G mismatches, initial products of DNA deamination by AID. These results suggest that MutSalpha interacts with the S regions in switching B cells to promote DNA synapsis and recombination.

Physiologic and microbiologic changes in skin related to frequent handwashing

Handwashing practices may be adversely influenced by the detrimental effects of handwashing on skin. A protocol was developed to assess the physiologic and microbiologic effects of frequent handwashing. Fifty-two female volunteers washed their hands 24 times per day for 5 days. Five agents were tested: water alone, non-medicated bar soap, a chlorhexidine-containing antiseptic, and two agents containing povidone-iodine (one currently available on the market and one being tested for possible marketing). Some damage to the outer membrane of skin, the stratum corneum, occurred in all groups. There were significant changes in the amount of evaporation water loss (p = .001) and in self assessments of skin condition (p = .005) from pre-to-post test for the entire group. Skin damage was also assessed by visualizing desquamating stratum corneum cells, which are shed in large aggregates when detergents injure skin. Significantly less such shedding occurred in subjects using water alone, bar soap, and the chlorhexidine formulation (p = .02). Greater antimicrobial activity of an agent was not correlated with increased skin trauma. We have quantitated, using objective physiologic parameter, the skin damage that occurs during even a short period of frequent handwashing. We recommend that further studies using the methods described be conducted to quantitate skin damage over longer periods of time, more closely resembling handwashing practices of health care personnel.

Prevalence and correlates of skin damage on the hands of nurses

OBJECTIVE

To describe the prevalence and correlates of skin damage on nurses' hands.

DESIGN

Prevalence survey using self-report questionnaire of hand care regimens, problems, and skin condition, and visual examination of the hands at 30X magnification by trained investigators to evaluate degree of skin scaling.

SETTING

Four hospitals: two in the Mid-Atlantic and two in the northern United States.

PARTICIPANTS

Convenience sample of 410 nurses working 30 hours or more per week in acute care units.

OUTCOME MEASURES

Damage to skin of the hands.

RESULTS

Approximately one fourth of subjects (n = 106) met the criteria for currently damaged hands; 85.6% (n = 351) reported ever having skin problems. Damage was not correlated with age (p = 0.43), sex (p = 0.14), or skin type (p = 0.25), type of soap used at home (p = 0.58), reported duration of handwashing (p = 0.12), or glove brand (p = 0.90), but was significantly correlated with the type of soap used at work (p = 0.01), number of hand washes per shift (p = 0.0003), number of times gloves were worn (p = 0.008), and study site (p = 0.009). Variables significantly predictive of skin damage in a logistic regression analysis were type of soap used at work and number of times gloves were worn (p = 0.04). Geographic location was not a factor, because both the highest and lowest prevalence of skin damage occurred in the northern study institutions.

CONCLUSIONS

Damage to skin of the hands is a common and potentially serious problem among nurses, and is associated with gloving and handwashing practices rather than with geographic or demographic factors. Efforts to improve skin condition must focus on improving products and identifying any interactive effects between hand care products and glove materials and brands.

Participation of older adults in health programs and research: a critical review of the literature

This collection of five papers evaluates the participation of older adults in clinical trials, health promotion/disease prevention initiatives, and health programs designed to maintain or improve the functioning of chronically ill older adults. Understanding the willingness or unwillingness of older adults to participate in these programs is critical to the development and implementation of health programs and policies for this population. In this introductory paper we briefly review illustrative literature to provide both an overview of the participation of older adults in health programs as well as background information relevant to the symposium papers.

Adjustment for selection bias in observational studies with application to the analysis of autopsy data

BACKGROUND

The interpretation of neuropathological studies of dementia and Alzheimer's disease is complicated by potential selection mechanisms that can drive whether or not a study participant is observed to undergo autopsy. Notwithstanding this, there appears to have been little emphasis placed on potential selection bias in published reports from population-based neuropathological studies of dementia.

METHODS

We provide an overview of methodological issues relating to the identification of and adjustment for selection bias. When information is available on factors that govern selection, inverse-probability weighting provides an analytic approach to adjust for selection bias. The weights help alleviate bias by serving to bridge differences between the population from which the observed data may be viewed as a representative sample and the target population, identified as being of scientific interest.

RESULTS

We illustrate the methods with data obtained from the Adult Changes in Thought study. Adjustment for potential selection bias yields substantially strengthened association between neuropathological measurements and risk of dementia.

CONCLUSIONS

Armed with analytic techniques to adjust for selection bias and to ensure generalizability of results from population-based neuropathological studies, researchers should consider incorporating information related to selection into their data collection schemes.

Reframing the meaning of disability to families: the embrace of paradox

In our society, families turn to medical science and health practitioners for assistance when a family member becomes disabled. In the cases of chronic illnesses and developmental disabilities, health professionals may focus interventions on the disease processes, feeling unprepared to deal with the broader issues families struggle with in managing disability. In addition, collaboration between professionals and parents may be strained when family's discourse is viewed as unrealistic, overly emotional, exceedingly optimistic and confusing by professionals. Using in-depth case studies, this qualitative research examined the daily occupations and subjective well-being of six Mexican-origin mothers parenting children with disabilities. Emergent findings demonstrated that these mothers do express apparently contradictory emotions of grief and joy, hope and fear that influenced their subjective well-being. The meaning of the mothers' contrary statements was illuminated in a life metaphor, the embrace of paradox. The embrace of paradox was the management of the internal tension of opposing forces between loving the child as he or she was and wanting to erase the disability, between dealing with the incurability while pursuing solutions and between maintaining hopefulness for the child's future while being given negative information and battling their own fears. The tensions created by the paradox promoted an internal striving to maintain a tenuous hopefulness despite "crashes" in their maternal work, and promoted an extension of maternal skills working toward a hopeful life trajectory for the mother and her child. In the embrace of paradox mothers created a positive bias and regained a sense of control that fueled their optimism in maternal work.

Compilance with isolation technique

We found that compliance with isolation precautions was less than optimal. It appeared that personnel were unaware of instances in which they had become contaminated. Increasing such awareness is indicated as an incentive to improve compliance. In addition, there were two areas in which education seemed to be indicated: for housekeeping staff to assure that they understood the need to contain infectious organisms within the isolation room as well as protecting themselves and for all personnel to identify the need for handwashing after removing gloves. Others have found that a careful monitoring program by an ICP can significantly reduce the overuse, but not underuse, of isolation. Such monitoring leads to considerable cost savings. We recommend that compliance with isolation technique be monitored on a periodic basis in other acute care institutions.

Leakage of virus through used vinyl and latex examination gloves

A total of 480 examination gloves (240 vinyl and 240 latex) were stressed by using manipulations designed to mimic patient care. At the highest use level, 38 (63%) of 60 vinyl gloves leaked bacteriophage phi X174 compared with 4 (7%) of 60 latex gloves. At lower use levels, there was no statistically significant difference in leakage.

Handwashing and skin. Physiologic and bacteriologic aspects

Handwashing practices are often based on tradition and belief. To develop sound rationale for handwashing practices, the physiologic and bacteriologic effects of handwashing must be examined. The purposes of this article are to review the three major microenvironments of the skin with their bacterial flora, to discuss physiologic and bacteriologic characteristics of the skin with particular reference to handwashing, and to describe current handwashing recommendations and practices.

Physiologic, microbiologic, and seasonal effects of handwashing on the skin of health care personnel

The handwashing practices of 22 personnel on an oncology unit in an urban medical center were studied for 2 months. During 891 person-hours of observation, 986 handwashes were observed. Subjects washed a mean of 1.1 times an hour for a mean of 13.2 seconds. Reported and observed handwashing behavior was only moderately correlated (p = 0.05 for frequency, 0.30 for duration of handwashing). Physicians washed significantly less often (p less than 0.001), but more thoroughly (p less than 0.001), than did nurses. Nurses washed more often after minimal or no patient contact than did physicians (p less than 0.001). Individuals were very consistent in their handwashing technique. A total of 558 isolates were recovered from 158 hand cultures. The mean log count was 4.88, with no significant difference between physicians and nurses. Coagulase-negative staphylococci isolated from hands of physicians and nurses were significantly more resistant to antimicrobial agents than those of personnel with minimal patient contact (p less than 0.01). Subjects had more skin damage in winter than in summer, as indicated by increased shedding of skin squames (p less than 0.05). We conclude that handwashing practices vary significantly by profession and that reporting of handwashing practices by personnel is inaccurate.

The impact of physician-nurse interaction on patient care

The perceptions of physicians and nurses vary in a number of respects, including the extent to which collaboration and joint decision making are valued, the definition of what constitutes adequate and appropriate interprofessional communication, the quality of nurse-physician interactions, and the understanding of respective areas of responsibility as well as patient goals. Reasons for these differences have been attributed to gender, historical origins of the two professions, and disparities between physicians and nurses with regard to socioeconomic status, education, and socialization. Failure of physicians and nurses to interact in a coordinated and positive fashion results in unhealthy work environments and poor patient outcomes. Both professions must examine their will to improve interprofessional interactions.