Malnutrition and experimental oral carcinogenesis

The work was undertaken to examine the effects of nutritional deficiencies on cancer induction. Two of the most common and widely distributed nutrients, iron and folic acid, were examined to evaluate the effects of their deficiency on animals. The Syrian golden hamster was the animal model for all experimental work. In the first part of the study an attempt was made to induce iron deficiency in young adult male hamsters by feeding iron deficient diet coupled with repeated venesection of 1.5ml every two weeks. Following twelve weeks on this regime a superficial biopsy was taken, on week 13, from the medial wall of one pouch in each hamster in order to evaluate the effect of iron depletion on the epithelial compartment thicknesses. After allowing the biopsy sites to heal for two weeks, a solution of 0.25% DMBA in acetone was painted, three times per week, for eight weeks, on a defined one square centimetre area in each pouch of each hamster of the experimental and control groups. The hamsters were then maintained on the same dietary regimes for twelve weeks before being killed at the beginning of week 37 for analysis. Iron deficiency anaemia could not be induced in the experimental animals of this study. The effect of the iron deficient diet on epithelial compartment thicknesses at the stage of the biopsy was not clear. However, restriction of iron intake did cause animals to develop significantly fewer grossly seen tumours and histologically identified carcinomas than control animals. In the second part of this thesis an attempt was made to investigate alternative hamster dietary components that have less iron contamination than the diet given in the first part of this thesis. Casein and calcium lactate were the main contributers to iron in the hamster diet. Casein could not be substituted by another source of protein for hamsters. However, other sources for calcium with less iron contamination were available and therefore investigated in this part of the study. Three groups of young adult male and female hamsters were given the fully nourishing powdered diet used in previous studies. However, calcium lactate was substituted for by either calcium acetate, calcium chloride or calcium sulphate in each group. None of the three diets was accepted by the animals and many of them died of starvation. When calcium salts were replaced by calcium lactate the surviving animals accepted the diet and recovered quickly afterwards. This study proved that calcium lactate could not be substituted by any other calcium salt with less iron content and therefore iron contamination in the hamster diet could not be further reduced by this method. In the third part of this thesis the effect of nutritional folate deficiency on cancer induction was studied. A group of young adult female hamsters was given folate deficient diet for four weeks. On week 5, DMBA in acetone at a concentration of 0.25% was painted on a defined one square centimetre area of the medial wall of each pouch in each hamster in folate deficient and control groups. The carcinogen was applied three times per week for eight weeks following which animals were maintained on the same dietary regimes for a further 13 weeks before being killed at the beginning of week 27 for the final analysis of the study. It was found that nutritional folate deficiency had significantly reduced the number of animals developing grossly counted tumours and histologically identified carcinomas. The folate deficient animals also developed significantly less tumours and carcinomas compared to control groups. In the last part of this thesis, the effect of combined iron and folate deficiency was examined for its role in carcinogenesis of the hamster cheek pouch. Two groups of young adult male hamsters were fed powdered diet lacking iron and folic acid and a third group was fed diet lacking iron only. One of the combined deficiency groups and the iron deficiency group were bled 1.0-1.3ml every week. On week 6 of the study DMBA in acetone at a concentration of 0.25% was painted three times per week for eight weeks on the same area of the pouch used in the previous studies. The animals were then maintained on the same experimental regimes for a further eleven weeks before being sacrificed, on week 25, for the final analysis of the study. In this study, iron deficiency anaemia was induced in animals of the bleeding groups. Animals in the group with combined iron and folate deficiency without bleeding showed low normal folate levels and normal haemoglobin levels. The two groups that were bled repeatedly showed iron deficiency anaemia. In all groups, the numbers of tumours counted grossly and the numbers of carcinomas identified histologically were significantly reduced compared to control animals in the previous studies. The folate deficient diet did not appear to influence the induction of iron deficiency. The studies reported in this thesis proved that nutritional folate deficiency not only reduces the incidence, but it also reduces the numbers of tumours and carcinomas in the hamster cheek pouch. Iron deficiency anaemia was also found to significantly reduce the numbers of tumours and carcinomas of the hamster cheek pouch. It was not possible to produce combined iron and folate deficiency under the conditions of these studies. However, animals fed on a diet lacking iron and folic acid had significantly reduced numbers of grossly seen tumours and histologically identified carcinomas in the cheek pouch in response to DMBA applications. In each of the reported studies, the nutritional deficiency of iron and folic acid, whether individually or combined was found to significantly reduce the growth rate of affected animals

Healthcare workers and health care-associated infections: knowledge, attitudes, and behavior in emergency departments in Italy

<p>Abstract</p> <p>Background</p> <p>This survey assessed knowledge, attitudes, and compliance regarding standard precautions about health care-associated infections (HAIs) and the associated determinants among healthcare workers (HCWs) in emergency departments in Italy.</p> <p>Methods</p> <p>An anonymous questionnaire, self-administered by all HCWs in eight randomly selected non-academic acute general public hospitals, comprised questions on demographic and occupational characteristics; knowledge about the risks of acquiring and/or transmitting HAIs from/to a patient and standard precautions; attitudes toward guidelines and risk perceived of acquiring a HAI; practice of standard precautions; and sources of information.</p> <p>Results</p> <p>HCWs who know the risk of acquiring Hepatitis C (HCV) and Human Immunodeficiency Virus (HIV) from a patient were in practice from less years, worked fewer hours per week, knew that a HCW can transmit HCV and HIV to a patient, knew that HCV and HIV infections can be serious, and have received information from educational courses and scientific journals. Those who know that gloves, mask, protective eyewear, and hands hygiene after removing gloves are control measures were nurses, provided care to fewer patients, knew that HCWs' hands are vehicle for transmission of nosocomial pathogens, did not know that a HCW can transmit HCV and HIV to a patient, and have received information from educational courses and scientific journals. Being a nurse, knowing that HCWs' hands are vehicle for transmission of nosocomial pathogens, obtaining information from educational courses and scientific journals, and needing information were associated with a higher perceived risk of acquiring a HAI. HCWs who often or always used gloves and performed hands hygiene measures after removing gloves were nurses, provided care to fewer patients, and knew that hands hygiene after removing gloves was a control measure.</p> <p>Conclusions</p> <p>HCWs have high knowledge, positive attitudes, but low compliance concerning standard precautions. Nurses had higher knowledge, perceived risk, and appropriate HAIs' control measures than physicians and HCWs answered correctly and used appropriately control measures if have received information from educational courses and scientific journals.</p

Preparedness of emergency departments in northwest England for managing chemical incidents: a structured interview survey

<p>Abstract</p> <p>Background</p> <p>A number of significant chemical incidents occur in the UK each year and may require Emergency Departments (EDs) to receive and manage contaminated casualties. Previously UK EDs have been found to be under-prepared for this, but since October 2005 acute hospital Trusts have had a statutory responsibility to maintain decontamination capacity. We aimed to evaluate the level of preparedness of Emergency Departments in North West England for managing chemical incidents.</p> <p>Methods</p> <p>A face-to-face semi-structured interview was carried out with the Nurse Manager or a nominated deputy in all 18 Emergency Departments in the Region.</p> <p>Results</p> <p>16/18 departments had a written chemical incident plan but only 7 had the plan available at interview. All had a designated decontamination area but only 11 felt that they were adequately equipped. 12/18 had a current training programme for chemical incident management and 3 had no staff trained in decontamination. 13/18 could contain contaminated water from casualty decontamination and 6 could provide shelter for casualties before decontamination.</p> <p>Conclusion</p> <p>We have identified major inconsistencies in the preparedness of North West Emergency Departments for managing chemical incidents. Nationally recognized standards on incident planning, facilities, equipment and procedures need to be agreed and implemented with adequate resources. Issues of environmental safety and patient dignity and comfort should also be addressed.</p

Impact of observing hand hygiene in practice and research: a methodological reconsideration

The purpose of hand hygiene is to break the chain of healthcare-associated infection. In many countries hand hygiene is regularly audited as part of quality assurance based on recommendations from the World Health Organization. Direct observation is the recommended audit method but is associated with disadvantages, including potential for being observed to alter usual behaviour. The Hawthorne effect in relation to hand hygiene is analogous with productivity improvement by increasing the frequency with which hand hygiene is undertaken. Unobtrusive and/or frequent observation to accustom staff to the presence of observers is considered an acceptable way of reducing the Hawthorne effect, but few publications have discussed how to implement these techniques or examine their effectiveness. There is evidence that awareness of being watched can disrupt the usual behaviour of individuals in complex and unpredictable ways other than simple productivity effect. In the presence of auditors, health workers might defer or avoid activities that require hand hygiene, but these issues are not addressed in guidelines for practice or research studies. This oversight has implications for the validity of hand hygiene audit findings. Measuring hand hygiene product use overcomes avoidance tactics. It is cheaper and generates data continuously to assess the compliance of all clinicians without disrupting patient care. Disadvantages are the risk of overestimating uptake through spillage, wastage, or use by visitors and non-clinical staff entering patient care areas. Electronic devices may overcome the Hawthorne and avoidance effects but are costly and are not widely used outside research studies

Impact of the Department of Health initiative to equip and train acute trusts to manage chemically contaminated casualties

Background: Before 1999, there was no national model or standard doctrine for managing casualties from chemical incidents in the UK. A Department of Health (DoH) initiative to prepare the National Health Service (NHS) for chemical incidents was launched in the same year. This led to the distribution of an NHS standard chemical personal protective equipment suit (CPPE) together with a new single half day training package (Structured Approach to Chemical Casualties (SACC)) in 2001. Objectives: To assess the impact of the DoH initiative on acute hospital and ambulance trusts. To identify deficiencies in the design and operational deployment of the new CPPE, training initiative, and decontamination procedures at hospital level. Method: A survey to assess progress in specific areas of chemical incident preparedness and two simulated incidents with "live" chemically contaminated casualties conducted in two acute trusts. Umpires evaluated the operational performance against DoH SACC standards. Results: There has been marked improvement in many aspects of preparedness for chemical incidents since the original National Focus survey. Some deficiencies remain and this study identified areas for further work. In the live casualty exercises, hospital staff complied well with SACC protocols. Some practical difficulties were encountered with the deployment of the CPPE and in some aspects of the operational response, leading to some delays in the delivery of care to the casualties and to the integrity of the uncontaminated (clean) zones within the hospitals. Conclusion: Problems with the design and deployment of the CPPE, together with training difficulties have been fed back into the planning and development process

Design and analysis of a microgrid based on an AC drive

Mikronät är ett självförsörjande elnät och används bland annat då elektriskaprodukter kräver en AC-spänning men inte har tillgång till huvudnätet. Målet idetta projekt är att dimensionera och analysera de olika delarna som ett mikronätbestår av, för att sedan konstruera och testa ifall den uppfyller kraven utifrånvissa specifikationer.Metoderna som används för att dimensionera och analysera mikronätet bestårfrämst av beräkningar och simuleringar samt konstruktion av enstaka kretsar.Mikronätet består av en AC-drive, ett lågpassfilter och trefastransformator.Mikronätet konstrueras med en varierbar frekvens mellan 45 och 65 Hz, samtomvandling av 540 VDC till 400 VAC

Design and analysis of a microgrid based on an AC drive

Mikronät är ett självförsörjande elnät och används bland annat då elektriskaprodukter kräver en AC-spänning men inte har tillgång till huvudnätet. Målet idetta projekt är att dimensionera och analysera de olika delarna som ett mikronätbestår av, för att sedan konstruera och testa ifall den uppfyller kraven utifrånvissa specifikationer.Metoderna som används för att dimensionera och analysera mikronätet bestårfrämst av beräkningar och simuleringar samt konstruktion av enstaka kretsar.Mikronätet består av en AC-drive, ett lågpassfilter och trefastransformator.Mikronätet konstrueras med en varierbar frekvens mellan 45 och 65 Hz, samtomvandling av 540 VDC till 400 VAC