Oral treatment of rodents with fipronil for feed-through and systemic control of sand flies (Diptera: Psychodidae)

The sand fly Phlebotomus papatasi Scopoli is the vector of Leishmania major (Yakimoff & Schokhor), which is maintained in populations of burrowing rodents. The purpose of this study was to conduct a laboratory study to determine the efficacy of oral treatment of rodents with fipronil for control of sand flies that feed on rodent feces as larvae or on rodent blood as adults. We determined through larval bioassays that fipronil was eliminated in feces of orally-treated hamsters at a level that was significantly toxic to sand fly larvae for 21 d after the hamsters had been withdrawn from a fipronil-treated diet. Through bloodfeeding bioassays, we also found that fipronil was present in the peripheral blood of hamsters at a concentration that was significantly toxic to bloodfeeding adult female sand flies for 49 d after the hamsters had been withdrawn from their treated diet. The results of this study suggest that fipronil acts as well as or better than feed-through or systemic insecticides that previously have been measured against sand flies, and is particularly promising because this single compound acts against both larvae and bloodfeeding adults. An area-wide approach using rodent baits containing a fipronil could suppress vector populations that originate in the vicinity of rodent reservoirs, and could be used to eliminate the most epidemiologically important part of the vector population: female sand flies that take bloodmeals on rodent reservoirs.

Evaluation of three feed-through insecticides using two rodent and two sand fly species as models

The efficacy of 3 rodent feed-through insecticides (novaluron, pyriproxyfen, and ivermectin) was determined against larvae of the sand flies Phlebotomus duboscqi and P. papatasi using Syrian hamsters (Mesocricetus auratus) and Mongolian gerbils (Meriones unguiculatus) as laboratory models. For each insecticide, there were no significant differences between the longevity or percentage survival of sand fly larvae that had been fed feces of treated rodents for each sand fly or rodent species pairing. The results of this study suggest that larvae of P. duboscqi and P. papatasi are equally susceptible to the concentrations of the rodent feed-through insecticides tested in this study and that these insecticides are pharmacologically compatible with different rodent/sand fly interactions.

Laboratory evaluation of rubidium as a long-lasting marker for bloodfeeding sand flies (Diptera: Psychodidae)

The objective of this study was to evaluate the use of the trace element rubidium (Rb) as a long-lasting systemic biomarker for bloodfeeding females of the sand fly Phlebotomus papatasi Scopoli. Baits containing Rb chloride were found to be palatable to hamsters in this study. We were able to detect Rb using a portable X-ray fluorescence analyzer in all sand flies that fed on Rb-treated hamsters for at least 14 d postbloodmeal. We also detected Rb in sand flies that took a bloodmeal from hamsters up to 10 d after the hamsters were withdrawn from a Rb-treated diet. Results of this study constitute proof of concept for the incorporation of Rb chloride into rodent baits for marking bloodfeeding sand flies, and suggest that Rb marking could be used as a technique for evaluating rodent-targeted sand fly control methods and in ecological studies on sand flies.

Comparison of adhesion formation associated with Pro-Tack (US Surgical) versus a new mesh fixation device, Salute (ONUX Medical)

BACKGROUND

We evaluated efficacy and associated adhesion formation of an innovative mesh fixation device versus the helical tack device and analyzed two implantation techniques.

METHODS

Six purpose-bred female hounds were evaluated in this 90-day survival study. Six 4-cm round patches of 1-mm thick DualMesh were fixed to the abdominal wall with either 10 Pro-Tack or 10 Salute constructs in each patch. Zero to 4 additional patches were implanted with only Salute constructs.

RESULTS

Adhesion severity scores were significantly higher for middle left abdominal wall sites versus lower right and upper left sites. The adhesion dissection score was higher for group T (Pro-Tack) versus group S (Salute).

CONCLUSION

No significant effects occurred with adhesion extent scores, but group T developed denser adhesions. The second analysis determined that no significant differences existed relevant to secondary Salute placement, although the total score approached significance (p < 0.09). Salute equipment was easier to handle and allowed repositioning of the patch during operation.

Changes in seasonal deaths from myocardial infarction

BACKGROUND

Cardiovascular disease is the major contributor to excess morbidity and mortality in winter. With the rise in temperatures through global warming, and the use of central heating and air conditioning, this seasonal variation may be declining.

AIM

To study possible changes in seasonal variation in case-fatality rates of myocardial infarction (MI), in men and women, over a 20-year period and compare this with possible environmental influences.

DESIGN

Retrospective analysis of death certificate and climatological data.

METHODS

We analysed all monthly death certificate data from Northern Ireland, for death caused by MI from 1979 through 1998 (n=68 683). Mortality data were standardized to a single reference group for the whole period. Seasonal variation in mortality and in environmental variables was described using the cosinor model.

RESULTS

A total of 29 875 women and 38 808 men died from MI during the 20-year period. A significant decrease in mortality from MI was observed in both sexes, accompanied by a non-significant decline in the amplitude of the seasonal rhythm over the study period. Low temperature was associated with higher mortality rates from MI.

DISCUSSION

We have documented an overall decline in cardiovascular mortality from 1979 to 1998, together with a small but non-significant decrease in seasonal variation. While improvements in medical care, lifestyle, housing and diet may have contributed to the observed decline in mortality rate, seasonal fluctuations remain a significant problem.

Tissue attachment strength of prosthetic meshes used in ventral and incisional hernia repair. A study in the New Zealand White rabbit adhesion model

BACKGROUND

Many prosthetic materials are used in incisional hernia repair, including polypropylene (PP) and expanded polytetrafluoroethylene (ePTFE). However, PP forms severe adhesions and ePTFE has raised concerns about the adequacy of tissue attachment.

METHODS

The early tissue attachment strength of PP and two new forms of ePTFE (DLM and DLMC) was compared in a rabbit model (n = 12) in which disks of the three meshes (n = 8 of each material) were implanted against the abdominal wall for 3 days.

RESULTS

Tensiometer testing found that DLMC mesh had significantly greater attachment strength than PP (p = 0.02). Histologic studies indicated that this was due to cellular ingrowth. Tissue adhesions were observed with all eight PP disks, one DLMC disk, and none of the DLM disks.

CONCLUSION

Modified forms of ePTFE mesh may provide abdominal wall repairs that are as strong or stronger than those obtained with PP, with early tissue attachment and without adhesions.

Common guidelines and equitable service: variation between adjacent districts regarding admissions to elderly care institutions

With the increasing number of older people, the cost of providing institutional care has become a major issue. In 1993 the introduction of care management and a needs-led approach aimed to remove the existing 'perverse incentive' to institutional care and to ensure equality in the dependency levels of those who were admitted to care. To test this consistency, we examined the dependency levels of all persons aged > or = 65 years admitted to residential and nursing homes in two adjacent Health and Social Services (HSS) Community Trusts in Belfast, Northern Ireland, in the year following the introduction of care management. We measured differences between the Trusts with respect to number of admissions, levels of dependency as determined by several standard scoring systems, financial support, source of admission and demographic information. A total of 389 people were surveyed. Trust A had significantly higher levels of physical dependency and mental impairment in both residential and nursing homes than Trust B. We also identified differences in dependency with respect to funding status, with those who were self-funding in Trust B having lower physical dependency in residential and nursing homes and less mental impairment in nursing homes than supplemented residents. This study reports the existence of variations between adjacent Community Trusts operating under the same policy guidelines with respect to the dependency levels of admissions to residential and nursing care. These differences may relate to number of places available, the economic status of the population, and the assessment procedures of the two Community Trusts. The need for standard assessment and eligibility criteria is highlighted.

Transcutaneous blood gas monitoring in the rat

Transcutaneous blood gas (TCBG) analysis is a noninvasive alternative method of estimation of blood gas tensions. The objective of the study reported here was to validate this method against standard blood gas (STBG) analysis in adult and juvenile Sprague-Dawley rats. We sought to establish the optimal TCBG probe site and temperature, to establish probe temperatures that would not cause thermal burns, to evaluate correlations between blood gas values (PaCO2 and PaO2) determined by use of TCBG and STBG, and to evaluate the sensitivity of the TCBG unit to changes in arterial blood gas partial pressures. Our results indicated that: in general, the xyphoid area was the optimal site for probe placement, with 44.5 degrees C being the optimal probe temperature for the highest correlation, but thermal burns may be a problem; probe temperatures of 42.5 degrees C (adults) and 42.0 degrees C (juveniles) do not cause thermal burns when left in place for three hours; probe temperatures of 44 degrees C (adults) and 42 degrees C (juveniles) resulted in moderate correlation between PaCO2 and PtcCO2; and the TCBG unit adequately responded to changes in arterial blood gas partial pressures. Neither PtcCO2 or PtcO2 reflect actual values of PaCO2 or PaO2, respectively. We concluded that TCBG analysis may be used as an indicator of change in PaCO2 with sufficient animal numbers under tightly controlled conditions, but not as an indicator of change in PaO2 in adult and juvenile rats.

Effect of tourniquet pressure and intra-individual variability on plasma fibrinogen, platelet P-selectin and monocyte tissue factor

Small differences in levels of certain haemostatic components may be clinically significant. It is important therefore to eliminate potential sources of confounding variability. This study investigated the effect of removing tourniquet pressure prior to sample collection on plasma fibrinogen levels, platelet P-selectin and monocyte tissue factor expression. Blood was collected from the right arm under maintained tourniquet pressure and from the left arm following the release of pressure once the vein was sufficiently inflated for insertion of a needle. Whole blood was labelled within one hour of venepuncture to allow analysis of platelet P-selectin and monocyte tissue factor by flow cytometry. Plasma fibrinogen levels were analysed in samples stored at -70 degrees C, for all individuals at the end of the study using a method based on the Clauss technique. Intra-individual variability for each of the components was assessed by collecting samples under tourniquet pressure from four individuals on the same day on three consecutive weeks. Intra-individual variations were greater than assay CVs for all three components. There were no significant differences between the two tourniquet methods of collection for fibrinogen, P-selectin or tissue factor. In conclusion, there is no reason not to use a tourniquet during collection of blood for analysis of plasma fibrinogen, platelet P-selectin or monocyte tissue factor.

The relationship between elevated fibrinogen and markers of infection: a comparison of seasonal cycles

To test the hypothesis that higher levels of fibrinogen in winter are related to infections via the acute phase response, we assessed seasonal variation in fibrinogen and C-reactive protein, together with three other responses to infection: white cell count, human herpesvirus-6 IgG antibody and interleukin-6. Monthly blood samples from 24 subjects aged 75+ years were assessed for fibrinogen, C-reactive protein, white cell count, and human herpesvirus-6 IgG antibody. Interleukin-6 was measured in seven. Seasonal variation of these measures was determined by the population-mean cosinor procedure. Fibrinogen had a significant seasonal variation with a winter peak (mid-February) 1.26 g/l above the corresponding summer trough. C-reactive protein had a late-February peak, 3.71 mg/l above the summer trough. No seasonal rhythm was found in any other response to infection investigated. This study provides no evidence that winter infections are responsible for the seasonal variation in fibrinogen or C-reactive protein. The explanation for the seasonal changes in these proteins remains unknown.

Singular beneficence? Presidential address to the Ulster Medical Society delivered on Thursday, 14 October 1999

Images

Acute clinical disease in cats following infection with a pathogenic strain of Bartonella henselae (LSU16)

Bartonella henselae is the causative agent of human cat scratch disease as well as several serious sequelae of infections, including bacillary angiomatosis and bacillary peliosis. Conflicting reports describe the pathogenesis of B. henselae in the cat. In this study, we characterized a strain of B. henselae termed LSU16. This strain was isolated on rabbit blood agar from a naturally infected 10-month-old female cat during a recurrent episode of bacteremia. The bacterial species was confirmed by PCR-restriction fragment length polymorphism analysis. Nine cats were infected intradermally with 5 x 10(7) CFU of LSU16, and clinical signs, antibody responses, and bacteremia were monitored. All nine cats developed raised, erythematous areas at the site of inoculation within 72 h postinoculation; the swelling peaked at 14 days postinfection and was not palpable by 28 days postinfection. Fever developed in all nine cats between 6 and 16 days postinfection and lasted for 1 to 8 days. Between 6 and 16 days postinfection, all nine cats experienced lethargy which persisted 5 to 18 days. Seven of nine cats were bacteremic by day 7, and all nine cats had become bacteremic by 14 days postinfection. Bacteremia peaked at 14 to 28 days postinfection in all cats. In six of the nine infected cats, bacterial numbers reached nondetectable levels during the 7th week postinfection; however, a single animal maintained bacteremia to 18 weeks postinfection. All nine cats developed strong antibody responses to B. henselae, as determined by Western blot analysis and enzyme-linked immunosorbent assay. Subsequently, three naive cats were injected intradermally with blood from cats infected with LSU16 from a pure culture, and five naive cats were injected with feces from fleas which had been feeding on cats infected with a pure culture of LSU16. These cats developed signs similar to those described in the previous experiment and were euthanized at 5 weeks postinfection. We conclude that B. henselae LSU16 is a virulent strain of B. henselae in cats and propose that the virulence of B. henselae in cats is strain dependent.

Prevalence of central autonomic neuropathy in elderly dialysis patients

BACKGROUND

Autonomic neuropathy is frequently present in dialysis patients. In addition, deterioration of autonomic function occurs with ageing. This study examines the true prevalence of autonomic neuropathy in elderly dialysis patients and questions whether the combination of age and uraemia further increases the chance of dysautonomia being present.

METHODS

We compared the results of five different tests (30:15 ratio; Valsalva ratio; heart rate response to deep breathing and the blood pressure responses to sustained hand grip and standing) of parasympathetic and combined parasympathetic and sympathetic dysfunction in older haemodialysis patients (mean age 70.2 years), younger haemodialysis patients (mean age 48.1 years) and two groups of subjects with normal renal function (mean age 73.0 years and 42.5 years respectively).

RESULTS

Parasympathetic dysfunction was most prevalent in older patients on dialysis (65.9% (95% confidence intervals 51.4-80.4%), compared with 33.3% (95% confidence intervals 19.0-47.5% in younger dialysis patients), and 11.8 and 0% in the old and young control groups respectively). Combined parasympathetic and sympathetic dysfunction was seen in 41.5% (95% confidence intervals 26.5-56.5%) and 11.9% (95% confidence intervals 2.1-56.5%) of the old and young dialysis patients respectively but not in any of the control subjects. No interaction was seen between age and subject type.

CONCLUSIONS

We conclude that although older dialysis patients have severe impairment of cardiovascular autonomic innervation, the prevalence of dysfunction is not higher than would be expected in an ageing population with uraemia.

Autonomic function in patients on continuous ambulatory peritoneal dialysis

OBJECTIVE

To investigate sympathetic function in the peripheries of patients on chronic ambulatory peritoneal dialysis (CAPD) using noninvasive techniques.

DESIGN

Comparison of peripheral blood flow responses in sympathetic vasoconstrictor reflexes in CAPD patients and matched control subjects.

SETTING

Tertiary care hospital and research institution.

PATIENTS

Twenty-three clinically stable CAPD patients and 23 control subjects matched for age, sex, and drug therapy.

MAIN OUTCOME MEASURES

Sympathetic activity assessed from the reductions in hand and foot blood flow induced by a deep breath and by body surface cooling. Cardiac autonomic activity measured by the changes in heart rate produced by deep breathing, a Valsalva maneuver, and standing from lying.

RESULTS

A deep breath induced mean decreases in hand blood flow of 65.1% in the patients and 82.8% in their matched controls. Corresponding reductions in the foot were 46.0% and 70.0%. Body surface cooling reduced mean hand blood flow by 50.3% in the patients and 71.8% in the control subjects. Corresponding values in the foot were 26.7% and 43.6%. The differences in response between the patients and their matched control subjects were all significant (p < 0.01). Cardiac autonomic function assessed by standard tests of heart rate variability was significantly impaired in the patients compared with the control subjects in two of the three tests used (p < 0.001).

CONCLUSIONS

Cardiovascular autonomic impairment can affect the peripheral circulation as well as the heart in patients on dialysis, and this may have implications for cardiovascular homeostasis.

Measurement of fibrinogen in frozen plasma

Several large studies have compared fibrinogen measurements determined over a particular time interval. These assays are subject to difficulties encountered by all laboratories on tests carried out over a period of time such as assay drift. To avoid this problem, plasma can be stored frozen and fibrinogen determined in a large number of samples simultaneously. However, a thorough comparison of measurements carried out in fresh and frozen plasma has not yet been performed. Fibrinogen concentration was therefore determined in fresh plasma samples and then at a later date in the same samples after storage at -70 degrees C. A good correlation was observed between the two measurements, however, bias increased at the higher fibrinogen levels which are most critical in the determination of thrombotic risk. An increase in measurement error as a result of freezing was also observed. These effects may, therefore, be important considerations in future studies of this nature.

Autonomic neuropathy predisposing to arrhythmias in hemodialysis patients

Arrhythmias are frequent among the dialysis population and can cause symptoms of palpitations or dizziness. Since autonomic disturbances are known to cause an increased arrhythmogenic stimulus, we questioned whether the presence of central autonomic neuropathy increased the frequency of arrhythmias as identified by 24-hour electrocardiographic monitoring in dialysis patients. Seventy-one patients were randomly chosen from patients established on dialysis in two centers. The mean age of the patients was 71.3 years (median age, 67 years) and median duration on dialysis was 17.0 months (range, 1 to 175 months). Four patients had diabetes. Each patient was tested for autonomic control of blood pressure and heart rate, and underwent Holter electrocardiographic monitoring, commencing 30 minutes before dialysis, for a 24-hour period. The tapes were then analyzed for ventricular and atrial rhythm changes. There was a significantly increased incidence of arrhythmias in individuals with abnormal blood pressure responses (P = 0.005), heart rate responses (P = 0.01), and combined blood pressure and heart rate responses (P = 0.004). We conclude that patients with autonomic dysfunction had an increased frequency of arrhythmias during dialysis.

Hyperinsulinemia and atherosclerosis

For more than 25 years, there has been an expansion in the clinical and experimental evidence linking hyperinsulinemia with cardiovascular disease and atherosclerosis. Assessment of the evidence under the headings of the strength of the association, dose response, temporality, consistency, specificity, and plausibility supports the concept that hyperinsulinemia has a causal role in atherogenesis. Evidence that reducing insulin levels prevents atherosclerosis is lacking. The evidence available is strong enough to support preventive measures to lower insulin levels such as regular physical exercise and avoidance of obesity.

Prognostic markers in older patients starting renal replacement therapy

AIMS

We assessed all patients starting renal replacement therapy during a 1-year period to identify factors influencing 1-year survival in older and younger dialysis patients.

METHODS

Data was collected from 113 patients. Twenty-four possible prognostic factors were introduced into a multivariate, time-based analysis.

RESULTS

Hazard ratios, and hence risk of mortality, were increased with increasing alcohol consumption, cardiac dyskinesis, age at onset of dialysis, serum phosphate, number of comorbid illnesses, and Karnofsky score (listed in decreasing order of risk). Risk of death within 1 year was reduced in patients with normal serum albumin and higher Barthel scores at the time of commencing dialysis. No age interactions were found. In the elderly age group the risk of death was also increased if left ventricular dilatation was present. Comorbidity and the age of onset were not independent risk factors in patients aged over 65 years at the time of starting dialysis.

CONCLUSIONS

All factors listed above increase the 1-year mortality of elderly patients. Factors known to increase medium-term morbidity in dialysis patients including diabetes mellitus, ischaemic heart disease, and hypertension do not appear to be important in the short-term survival of older patient on dialysis.

Seasonal changes in haemostatic factors in young and elderly subjects

Morbidity and mortality from cardiovascular disease are more common in colder seasons, especially in elderly people. Previous studies have shown higher fibrinogen levels in old people in the winter months. The present studies of haemostatic factors in relation to age and season have shown that fibrinogen, tissue plasminogen activator (tPA), protein S and protein C levels are higher in old (aged 75 years and over) than young (aged 25-30 years) subjects while antiplasmin levels are lower in old people. Antiplasmin and protein C levels are lower in winter in both young and old while plasminogen activator inhibitor (PAI) is higher, and tPA higher in old people only. This study illustrates the complex interrelationships of the haemostatic system and may suggest that in 'successful' elderly people the fibrinolytic system may alter to maintain the delicate balance between thrombogenic and fibrinolytic activity. Nevertheless, the results presented here suggest that both old age and cold weather may increase the risk of atherothrombotic disease.

The assessment of acute stroke in general medical wards

In order to assess the completeness of clinical clerking, a retrospective study was made of the medical notes of 194 patients admitted with acute stroke over a 1-year period. The noting of clinical features associated with disease severity and prognosis, such as level of consciousness, proprioception, neglect, mental test score and continence was assessed. These features were rarely noted. Factors likely to influence placement following recovery were also poorly reported. In order to allow an accurate guide to stroke severity and prognosis these factors must be noted. An alternative form of clinical clerking is suggested in order to improve patient management.

Diagnostic regimes for urinary tract infection--are research results applied to practice?

A clinical audit of ward practice for diagnosing and treating urinary tract infection was carried out to assess the impact on clinical practice four years after publication of a working protocol. Data were collected from all medical, surgical, gynaecology and geriatric wards in 25 hospitals in Northern Ireland. All wards made use of urinary dipsticks for ward testing, as recommended by the protocol. However many negative samples were still forwarded for laboratory analysis. The potential financial savings which would result from effective ward screening were not being realised and the publication appeared to have minimal impact on clinical practice. Advice on an improved diagnostic protocol for urinary tract infection may not have been disseminated to the nursing staff whose role was pivotal in the screening process.

Conservative podiatric medicine and disability in elderly people

A survey was conducted of 248 noninstitutionalized people aged 75 years and older, residing in a designated geographical area. The effect of dependency and physical disability on the receipt of conservative podiatric medicine was examined, and, in addition, the prevalence of medical and podiatric conditions was determined.

Glucose Tolerance and Ageing

Hyperglycaemia, impaired glucose tolerance and non-insulin dependent diabetes become progressively more common with advancing age. The mechanism is insensitivity to the actions of insulin at the postreceptor level. Inadequate secretion of insulin and decreased hepatic sensitivity to insulin's action in suppressing glucose output also occur. The age-related changes may be made worse by obesity, renal failure or the ingestion of certain drugs, or may be lessened by increased physical activity.

Viral hepatitis in the U.S. Air Force, 1980-89: an epidemiological and serological study

This paper reports the epidemiology of hospital-diagnosed acute viral hepatitis in U.S. Air Force personnel from 1980-89. First hospitalizations for viral hepatitis generally declined, ranging from 24.6 to 47.2 per 100,000 personnel. Hepatitis rates were higher among men, (RR = 1.3; 95% C.I., 1.1-1.5) and higher among blacks, compared to whites (RR = 1.4; 95% C.I., 1.3-1.6). Analysis of risk associated with various occupations demonstrated an increased risk of viral hepatitis for procedurally oriented medical personnel (physicians, clinical nurses, dentists) when compared to all other occupations (RR = 1.5; 95% C.I., 1.1-1.9). Pilots and navigators demonstrated a decreased risk of acute viral hepatitis. Members hospitalized for hepatitis B had a prior or concurrent diagnosis for sexually transmitted disease in 37% of cases; for drug abuse, 32% of cases. Serum samples from 332 individuals demonstrated that hepatitis A had the highest rate of agreement (84%) between serology and hospital discharge diagnosis. Only 3% of individuals with the diagnosis of NANB hepatitis were positive for hepatitis C.

Duration of antibody response after meningococcal polysaccharide vaccination in US Air Force personnel

The long-term kinetics of the immunologic response after vaccination of adults with Neisseria meningitidis polysaccharide vaccine is unknown. Total meningococcal anti-capsular antibody response (measured by ELISA) and serum bactericidal activity after routine vaccination with quadrivalent meningococcal vaccine were evaluated in US Air Force personnel. In a retrospective cross-sectional study, blood samples were obtained from approximately 40 personnel before vaccination, at 1 and 4-6 months, and at 2, 3, 4, 6, 8, and 10 years after vaccination. Total anti-group A and -group C capsular antibody levels and bactericidal activity peaked 1 month after vaccination and declined substantially by 2 years. At each interval, significantly higher levels of total antibody and bactericidal activity were detected than before vaccination. Anti-capsular antibodies and bactericidal activity persisted for up to 10 years after immunization. These and further studies on the serologic measure of protection against meningococcal disease are important for evaluation of candidate vaccines and development of recommendations for immunization.

Alcohol-related mortality in the U.S. Air Force, 1990

Alcohol-related morbidity and mortality represent a major public health problem in the United States, particularly among young men. Standardized comparisons of alcohol use have demonstrated that members of the military consume more alcohol than matched civilians. To quantify the impact of alcohol use by active duty members of the Air Force for calendar year 1990, we reviewed 283 death certificates and analyzed the cause of death using the Alcohol-Related Disease Impact (ARDI) computer program. Injuries accounted for 73% of all deaths among active duty Air Force personnel, with motor vehicle accidents (MVAs) accounting for 31% of total mortality. Sixty-six deaths (23%) were attributable to alcohol-related causes and accounted for 2,300 years of potential life lost before 65 years of age. Analysis of blood alcohol levels taken from a subset of active duty deaths resulting from MVAs and suicides yielded alcohol-attributable fractions similar to those obtained by the ARDI method. Periodic assessment and dissemination of alcohol-related mortality statistics in the military using the ARDI methodology represent an important public health education tool.

Hyperglycaemia and mortality from acute stroke

Hyperglycaemia has been observed after acute stroke, and is associated with a poor prognosis. It is not known whether this is due to the stress response of the acute illness or whether hyperglycaemia is, in itself, harmful to ischaemic nervous tissue. Seventy-one patients admitted to hospital with acute stroke and no history of diabetes or other acute illness were recruited, and fasting blood sampling was carried out within 24 h of symptom onset, for plasma glucose and stress hormones and levels of haemoglobin A1c (HbA1c). Computerized tomography of the brain was carried out on 77% of the subjects. The subjects were followed up for 3 months or until death. Glucose levels were higher in subjects who died during the course of the study (p = 0.025), but this relationship became non-significant after age (p < 0.001) and cortisol (p = 0.001) levels were taken into account with multivariate analysis. The correlation between serum cortisol and the volume of the lesion on CT scan was also stronger than the relation of glucose with volume. Haemoglobin A1c had no relationship with either mortality or lesion volume. These findings suggest that the hyperglycaemia seen after an acute stroke is secondary to a stress response and they do not support the theory of hyperglycaemia being harmful to ischaemic nervous tissue. These findings have implications for the treatment of acute stroke with hypoglycaemic agents.

Differences between "geriatric" and "medical" patients aged 75 and over

We analysed the characteristics of patients aged 75 and over admitted to the geriatric and general medical wards over a three month period in a teaching hospital. Patients admitted to the geriatric wards were slightly older, were more often female, more likely to be admitted during the day and during a week day, more likely to have been seen by their own general practitioner, had more chronic and multiple illness with non-specific presentations, and stayed longer in hospital. Referring doctors seem to discriminate between patients needing geriatric care and those more suitable for general medical care, but there is an overlap in the characteristics of the two groups.

Viral hepatitis in the US Air Force, 1980-1989

Viral hepatitis and its acute and chronic complications continue to pose significant threats to the readiness of military personnel. Knowledge about the specific viral agents and their routes of transmission are important in developing prevention strategies. A recent analysis of hepatitis in the US Navy for the period 1975-1984 is reviewed. In order to better characterize the risk of viral hepatitis among US Air Force personnel, a comprehensive review of inpatient and quarters data for hepatitis A, B and 'non-A, non-B' were reviewed from Air Force medical treatment facilities worldwide for the period 1980-1989. Following a discussion of the study methodology, preliminary data and hepatitis type-specific demographic risk variables are discussed. Preliminary results from a hepatitis serosurvey (A, B and C antibody with use of a supplemental validating assay) of the subset of the study cohort who are currently on active duty are briefly reviewed.

Diabetes and atherosclerosis

Atherosclerosis is the most important complication of diabetes and diabetes is an important risk factor for cardiovascular disease. Atherosclerosis develops more rapidly and at an earlier age in diabetic patients than in non-diabetic people. Although a number of cardiovascular risk factors are more common in diabetic than non diabetic people, these do not entirely account for the increased frequency of cardiovascular disease. The identity of the additional factor or factors which result in increased atheroslerosis in diabetes is unknown but attention should be paid to the role of glycated lipoproteins and of hyperinsulinaemia. In treating diabetic patients, attention should be paid to cardiovascular risk factors such as dyslipidaemia and hypertension as well as to the control of blood glucose.

A comparison of community care of elderly people in Wales and Northern Ireland

This study compares the provision of community services for elderly people in Wales and Northern Ireland using data from two independent surveys. Despite sampling and definitional problems, certain interesting comparisons can be obtained. In general, elderly people in the Northern Ireland sample seem more likely to be dependent and more disabled than those in Wales. Northern Ireland people receive less help, but the help given is more likely to be from statutory services than in Wales; in many cases statutory help is the sole source of support. Further, in Wales there is more specialized care for very disabled elderly people living in the community, and the work is more likely to be shared by carers and the statutory services. There is however still considerable unmet need in both countries. A comparative study using common definitions and methods would be of considerable interest in relation to the debate concerning the relative shares of health care resources in the United Kingdom.

Insulin and atherogenesis

A number of processes are involved in the pathogenesis of atherosclerosis. These include an "injury" to the endothelial cell barrier of the inner lining of the artery, infiltration of the artery by lipid filled monocyte-macrophages, proliferation of smooth muscle cells, synthesis of connective tissue and thrombus formation. Insulin may be involved in several of these processes. Over 40 years ago it was shown that insulin is necessary for the production of experimental atherosclerosis in cholesterol fed, alloxan diabetic rabbits. Insulin inhibits regression and stimulates formation of lipid containing lesions in a number of species, and can promote lesions in animals fed normal diets. Insulin is also related to lipid metabolism in the artery wall and interacts with blood pressure to stimulate lipid synthesis in arteries. Arterial smooth muscle cells cultured from a number of species including humans proliferate in response to levels of insulin similar to those found in normal human physiology. The proliferative effects of insulin are mediated by the insulin-like growth factor receptor and hence may not be impaired in states of insulin resistance. Insulin also stimulates arterial smooth muscle cell migration. Insulin stimulates cholesterol synthesis in cultured smooth muscle cells and enhances LDL receptor activity in a number of cell types. Insulin stimulates connective tissue synthesis, and promotes clotting.

Readmissions to a geriatric medical unit: is prevention possible?

Of the 622 patients admitted to a geriatric medical unit during the period November 1985 to October 1986, 211 (33.9%) had been discharged from hospital within the previous year. Of these, 117 (55.5%) had previously been admitted to the geriatric medical unit (18.8% of all admissions). The reasons for readmission were deterioration of existing disease (47.4%), new medical events (33.2%), poor management of previous discharge (9.5%), and social problems (5.7%). Age was not a significant factor influencing readmission. Readmission was judged preventable by better management of the previous admission and discharge in only 33 cases (15.6% of readmissions). A prospective study of the patients discharged in the same year revealed that 19.3% were readmitted in the following year, and of these readmissions 2.3% were considered to be preventable. There was no difference in medical causes for readmission in the two years. A significant number of the patients readmitted in both years studied was categorized as "high dependency". The figures suggest that although unplanned readmission is common, it is generally not preventable by better management of the previous admission, and often reflects a highly dependent and medically frail group of patients, in whom early intervention with readmission is appropriate.