N-Acetylcysteine inhibits platelet-monocyte conjugation in patients with type 2 diabetes with depleted intraplatelet glutathione: a randomised controlled trial

AIMS/HYPOTHESIS

The aim of this study was to determine whether oral dosing with N-acetylcysteine (NAC) increases intraplatelet levels of the antioxidant, glutathione (GSH), and reduces platelet-monocyte conjugation in blood from patients with type 2 diabetes.

METHODS

In this placebo-controlled randomised crossover study, the effect of oral NAC dosing on platelet-monocyte conjugation and intraplatelet GSH was investigated in patients with type 2 diabetes (eligibility criteria: men or post-menopausal women with well-controlled diabetes (HbA(1c) < 10%), not on aspirin or statins). Patients (n = 14; age range 43-79 years, HbA(1c) = 6.9 ± 0.9% [52.3 ± 10.3 mmol/mol]) visited the Highland Clinical Research Facility, Inverness, UK on day 0 and day 7 for each arm of the study. Blood was sampled before and 2 h after oral administration of placebo or NAC (1,200 mg) on day 0 and day 7. Patients received placebo or NAC capsules for once-daily dosing on the intervening days. The order of administration of NAC and placebo was allocated by a central office and all patients and research staff involved in the study were blinded to the allocation until after the study was complete and the data fully analysed. The primary outcome for the study was platelet-monocyte conjugation.

RESULTS

Oral NAC reduced platelet-monocyte conjugation (from 53.1 ± 4.5% to 42.5 ± 3.9%) at 2 h after administration and the effect was maintained after 7 days of dosing. Intraplatelet GSH was raised in individuals with depleted GSH and there was a negative correlation between baseline intraplatelet GSH and platelet-monocyte conjugation. There were no adverse events.

CONCLUSIONS/INTERPRETATION

The NAC-induced normalisation of intraplatelet GSH, coupled with a reduction in platelet-monocyte conjugation, suggests that NAC might help to reduce atherothrombotic risk in type 2 diabetes.

FUNDING

Chief Scientist Office (CZB/4/622), Scottish Funding Council, Highlands & Islands Enterprise and European Regional Development Fund.

TRIAL REGISTRATION

isrctn.org ISRCTN89304265.

The clinical outcome of UK military personnel who received a massive transfusion in Afghanistan during 2009

OBJECTIVES

The UK Defence Medical Services has developed a Massive Transfusion Protocol (MTP) that forms part of the initial Damage Control Resuscitation process for severely injured combat casualties. The key objectives of this retrospective review of MTP recipients are to document the survival rates, level of critical care support required and the blood components transfused as part of the Massive Transfusion Protocol in Afghanistan during 2009. In addition to providing a measure of our current effectiveness it should also provide a reference point for future reviews as the MTP continues to evolve.

METHODS

This was a collaborative project involving the Royal Centre for Defence Medicine and the Critical Care Department, University Hospitals Birmingham. It was limited to UK military personnel who were injured in 2009 and received massive transfusions (defined as the transfusion of 10 or more units of packed red blood cells over a 24-hour period) at Camp Bastion Role 3 Medical Facility, Afghanistan.

RESULTS

During the 12-month period, 59 personnel received massive transfusions. 51 (86%) personnel survived to be discharged from hospital in the UK. 48 (92%) personnel required ventilatory support for a median of 3 (2-8) days. The longest period of ventilation was 40 days; 29 (55%) personnel required vasopressor support and eight personnel (15%) required renal replacement therapy. The median total transfusion of blood components was 45 (28.5-62) units. There were seven transfusions of more than 100 units. Five of the personnel in this group (including the recipient of a 237-unit transfusion) survived to be discharged from University Hospitals Birmingham. On average, 1.21 (SD 0.28) units of packed red blood cells were transfused for every unit of fresh frozen plasma.

CONCLUSIONS

The use of the current MTP was associated with a high rate of survival. Survivors require a continuity of critical care with a median demand for 3 days. The early use of plasma and platelets can be successfully delivered in the battlefield despite operational and logistic constraints.

THE EXPERIMENTAL DISCLOSURE OF LATENT NEOPLASTIC CHANGES IN TARRED SKIN

A carcinogenic tar applied to rabbit skin renders many more epidermal cells neoplastic than ever declare themselves by forming tumors. They may be present in large numbers and persist for a considerable time after brief tarring, yet give rise to no growths unless encouraged. The stimulus of wound healing will suffice to make some of them multiply and form tumors. No evidence has been obtained, in experiments specifically directed to the point, that the cells which tar renders neoplastic respond in this way because they are possessed of peculiarities not shared by the rest of the normal epithelium. The fact that non-specific stimulation (as e.g. wound healing) may act as the deciding influence in tumor formation brings out the need for a sharp distinction between the forces which induce neoplastic change and those which determine, or prevent, its realization in terms of a tumor. The distinction is vital to the appraisal of the many carcinogenic substances worked with nowadays. The ability of tumor cells to lie latent for long periods and respond to non-carcinogenic stimulation by multiplying into growths provides an explanation of those clinical instances in which cancer appears rapidly after acute injury to tissue that had seemed normal.

INCIDENCE AND SPECIFICITY OF THE ANTIBODY FOR A DISTINCTIVE CONSTITUENT OF THE BROWN-PEARCE TUMOR

A detailed study has been made of an antibody which appears in the blood of certain rabbits implanted with the Brown-Pearce carcinoma or injected with extracts of it and which reacts specifically in vitro in mixture with a distinctive sedimentable constituent of the Brown-Pearce tumor cell. The observations as a whole seem to indicate that this constituent of the Brown-Pearce tumor differs notably from certain other sedimentable substances which can be extracted from various rabbit tissues and identified by serological means. The implications of the findings are discussed.

Deafness--the neglected and hidden disability

The problem of deafness or hearing loss is increasing world-wide. In countries rich and poor, people are living longer, and presbyacusis, the deafness of old age, is becoming more frequent. Hearing loss is a chronic and often life-long disability that, depending on the severity and the frequencies affected, can cause profound damage to the development of speech, language, and cognitive skills in children, especially if commencing prelingually. That damage, in turn, affects the child's progress in school and, later, his or her ability to obtain, keep, and perform an occupation. For all ages and for both sexes, hearing loss causes difficulties with interpersonal communication and leads to significant individual social problems, especially isolation and stigmatization. All of these difficulties are much magnified in developing countries, where there are generally limited services for the hard of hearing, few people trained to help those with hearing loss, and little awareness about how to deal with the difficulties associated with such loss. Although deafness and hearing impairment are likely to have huge economic effects in such countries, in most areas these effects remain to be quantified.

WITHDRAWN: Interventions for chronic suppurative otitis media

BACKGROUND

Chronic suppurative otitis media (CSOM) is a serious bacterial infection of the middle ear that can follow untreated acute otitis media.

OBJECTIVES

To assess the effects of different treatments for CSOM.

SEARCH STRATEGY

We searched Medline from 1966 to 1996 and a bibliographic collection of the Hearing Impairment Research Group in Liverpool, UK. We handsearched two otolaryngology journals and contacted members of an international hearing network.

SELECTION CRITERIA

Randomized trials of any method of management for patients with eardrum perforation and persistent otorrhea.

DATA COLLECTION AND ANALYSIS

Three reviewers independently assessed eligibility and trial quality. One reviewer extracted data. We contacted investigators for clarifications.

MAIN RESULTS

Twenty-four trials involving 1660 people were included. Clinical definitions and severity of CSOM varied, methodological quality was generally low and follow-up was short. Treatment with antibiotics or antiseptics accompanied by aural toilet was more effective in resolving otorrhea than no treatment (two trials, odds ratio 0.37, 95% confidence interval 0.24 to 0. 57) or aural toilet alone (six trials, odds ratio 0.31, 95% confidence interval 0.23 to 0.43). Topical treatment with antibiotics or antiseptics was more effective than systemic antibiotics (six trials, odds ratio 0.46, 95% confidence interval 0.30 to 0.69). Combining topical and systemic antibiotics was not more effective than topical antibiotics. Topical quinolones were more effective than non-quinolones (five trials, odds ratio 0.26, 95% confidence interval 0.16 to 0.41). No difference in the effectiveness of topical antibiotics and topical antiseptics was found (three studies, odds ratio 1.34, 95% confidence interval 0.64 to 2.81). Some topical antibiotic combinations may be more effective than others in resolving otorrhea. Rates of adverse drug events were low and equal between groups.

AUTHORS' CONCLUSIONS

Treatment of CSOM with aural toilet and topical antibiotics, particularly quinolones, is effective in resolving otorrhea and eradicating bacteria from the middle ear. Longterm outcomes such as preventing recurrences, closure of tympanic perforation and hearing improvement need to be further evaluated.

An unusual extraction; retrieval of a swallowed crown by appendicectomy

We report the case of a patient who swallowed a crown and three weeks later presented with abdominal pain and fever. At operation his crown was found to be causing appendicitis. Foreign bodies have previously been reported as causing appendicitis but never a crown. We discuss the appropriateness of abdominal radiology in the management of such foreign bodies.

Tinnitus and Paget's disease of bone

Aim: To investigate the prevalence of tinnitus and deafness in subjects with Paget's disease of bone.

Materials and methods: One hundred and thirty-four subjects in total (77 with Paget's disease) were identified and audiologically examined. Subjects' experience of tinnitus was surveyed via a questionnaire and the results compared with those of age-matched controls.

Results: Hearing loss in those with Paget's disease of bone was significantly worse than in controls. Hearing handicap was also much worse in the Paget's subjects. Sixty-one per cent of the Paget's subjects suffered from tinnitus, compared with 36 per cent of the controls.

Conclusion: Deafness is a recognized, common sequelae of Paget's disease of bone, and tinnitus is a common accompanying symptom.

Ileostomy rod--is it a bridge too far?

OBJECTIVE

Defunctioning loop ileostomies are used commonly to protect low colorectal anastomoses and thereby reducing the serious complications of leakage. However, they are associated with specific complications such as retraction. Traditionally, a supporting rod is placed as a bridge to support both limbs of the stoma in the hope of reducing the incidence of stomal retraction. There is little evidence in the published literature to support this practice. The aim of this study was to determine whether using an ileostomy rod would reduce the incidence of stomal retraction.

METHOD

A prospective, randomised controlled trial was performed in 60 consecutive patients who required a defunctioning loop ileostomy. Patients were allocated to either a 'bridge' or 'bridge-less' protocol. All the patients were assessed by dedicated stoma nurses for at least 3 months and until their stomas were closed. Their postoperative symptoms, including stoma activity and retraction rate, were recorded.

RESULTS

Between May 2001 and June 2004, 57 patients completed the study (28 bridge; 29 bridge-less). There were no significant differences in the retraction rate between the groups. No clinical anastomotic leakage was recorded and none of the patients required early closure.

CONCLUSIONS

If a loop ileostomy is constructed properly, stomal retraction is uncommon and routine use of a bridge is unnecessary.

Prospective analysis of stoma-related complications

BACKGROUND

Stoma-related complication rates vary between 10% and 70%, possibly because of varying lengths of follow-up. It is thought that most of the complications improve with time. Furthermore, little is known about the commonly neglected but potentially quite distressing complications such as leakage, soiling and night-time emptying. The aim of this audit was to examine prospectively whether there was any difference in the complication rates at different time-points during the postoperative follow up period.

METHOD

A prospective study on 408 consecutive patients with either colostomy or ileostomy was conducted over a period of at least 2 years. Both emergency and elective procedures were included. Stoma related complications were analysed at 10 days, 3 months, 6 months, 1 year and 2 years postoperatively.

RESULTS

Both elective and emergency stomas had similar complication rates. The percentage of patients who had stenosis (1-2%), retraction (8-22%), prolapse (1-3%) or odour (6-9%) did not significantly change with time. The complication rates for skin excoriation, leakage, soiling or night-time emptying were higher amongst the ileostomy patients, and these rates did not improve with time. The proportion of patients who had parastomal hernias increased with time (from 0 to 40% in the colostomy and 0 to 22% in the ileostomy group). Daytime leakage, night-time leakage, soiling and night-time emptying were more problematic in the ileostomy group.

CONCLUSIONS

The proportion of patients who had postoperative stoma-related complications did not improve with time, but the rate of parastomal hernias in both groups and night-time emptying in the ileostomy group was worse with time. Ileostomy patients had a higher incidence of skin excoriation, leakage, soiling, and night-time emptying, and they should receive additional support.

Primary aortoenteric fistula: pitfalls in the diagnosis of a rare condition

Primary aortoenteric fistula is such a rare condition that even specialist vascular surgeons may not encounter one in their lifetime practice. Any hope of survival depends upon prompt diagnosis and surgical treatment. We present our experience of one such case, particularly the difficulties encountered in confirming the diagnosis, and go on to review the literature on the subject. Both our experience and that reported by previous authors would suggest that specialized investigations such as computed tomography, contrast angiography, radionuclide scintigraphy, and gastrointestinal endoscopy have only a limited contribution to make in confirming the diagnosis of primary aortoenteric fistula. The diagnosis should be considered in any patient with gastrointestinal blood loss and an abdominal aortic aneurysm. Specialized investigations should not be relied upon to confirm or refute the diagnosis. Any prospect of survival is dependant upon prompt diagnosis and surgical intervention. The latter is only achieved by a high index of clinical suspicion.

Retrospective study of management of uterine sarcomas at Oxford 1990-1998: role of adjuvant treatment

We report a retrospective study of 47 consecutive patients with uterine sarcoma treated at the Churchill Hospital in Oxford between 1990-1998. The mainstay of treatment was surgery with adjuvant chemotherapy and radiotherapy reserved for selected patients with early stage disease. Overall 1 and 2 year survival was 49% and 30% respectively compared with 73% and 55% in the group who received adjuvant chemotherapy/radiotherapy. Median survival was 11 months for the group as a whole compared to 32.9 months in the adjuvant therapy group. This is a retrospective review with small numbers and considerable selection bias, however, given the poor survival of patients with this disease, adjuvant treatment should be considered in future trials of patients with uterine sarcoma.

Radiation-induced glioma presenting as diffuse leptomeningeal gliomatosis: a case report

BACKGROUND

Leptomeningeal gliomatosis is a rare and fatal disease.

METHODS

Case report.

RESULTS

We report the case of a man who was presented with severe intractable headaches, lymphocytic CSF pleocytosis, and spinal leptomeningeal enhancement on contrast MRI. Meningeal biopsy demonstrated diffuse infiltration by malignant glial cells, and symptom alleviation was achieved by CSF diversion. He later developed an enhancing thalamic tumor arising within the treatment field of a remotely irradiated pituitary adenoma. Subsequent management included chemotherapy and further radiotherapy with transient response, before death from leptomeningeal and parenchymal tumor progression 16 months after diagnosis.

CONCLUSION

We report a unique case embodying two rare conditions: radiation induced glioma and leptomeningeal gliomatosis. Our patient's course is novel in that symptomatic relief was achieved with CSF diversion and a combination of chemotherapy and focal radiation allowed prolonged survival.

Housing and health: does installing heating in their homes improve the health of children with asthma?

The objective of this study was to evaluate the use of NHS money to improve health by improving housing conditions. A pilot study assessing health outcomes before and after improving housing conditions was conducted, studying 72 children with previously diagnosed asthma living in 59 damp houses in Cornwall. The intervention was the installation of central heating. This improved the energy efficiency of the housing. The children's health was a symptom-based outcome measure for asthma and time lost from school. Improvements comprised installation of gas central heating in 28/59 (47%) houses, electric storage heaters in 22/59 (37%), solid fuel central heating in 7/59 (12%) and oil-fired central heating in 2/59 (4%) houses. Energy efficiency improved by a mean of 2.1 on the National Home Energy Rating scale (95% CI 1.68-2.47, P<0.001) in the 37/59 (62%) houses for which two readings were available. Initially, 69/72 (92%) children's bedrooms were unheated and 44/72 (61%) were damp; following improvements, the proportions were 10/72 (14%) and 15/72 (21%) respectively. All respiratory symptoms were significantly reduced after intervention; the greatest reduction was seen in nocturnal cough from a median score of 3 (most nights) to 1 (on one or several nights) (P<0.001) in the previous month. School-age children lost significantly less time from school for asthma in the previous 3 months (9.3 days per 100 school days before intervention and 2.1 days afterwards, P<0.01) but not for other reasons (1.4 days per 100 school days before and 3.2 after, P>0.05). In conclusion, this study provides the first evaluation of health outcomes following housing improvements. Lack of a comparison group means that effects of age, season and biased reporting cannot be eliminated. More work is needed to substantiate these results.

Interventions for chronic suppurative otitis media

BACKGROUND

Chronic suppurative otitis media (CSOM) is a serious bacterial infection of the middle ear that can follow untreated acute otitis media.

OBJECTIVES

To assess the effects of different treatments for CSOM.

SEARCH STRATEGY

We searched Medline from 1966 to 1996 and a bibliographic collection of the Hearing Impairment Research Group in Liverpool, UK. We handsearched two otolaryngology journals and contacted members of an international hearing network.

SELECTION CRITERIA

Randomized trials of any method of management for patients with eardrum perforation and persistent otorrhea.

DATA COLLECTION AND ANALYSIS

Three reviewers independently assessed eligibility and trial quality. One reviewer extracted data. We contacted investigators for clarifications.

MAIN RESULTS

Twenty-four trials involving 1660 people were included. Clinical definitions and severity of CSOM varied, methodological quality was generally low and follow-up was short. Treatment with antibiotics or antiseptics accompanied by aural toilet was more effective in resolving otorrhea than no treatment (two trials, odds ratio 0.37, 95% confidence interval 0.24 to 0. 57) or aural toilet alone (six trials, odds ratio 0.31, 95% confidence interval 0.23 to 0.43). Topical treatment with antibiotics or antiseptics was more effective than systemic antibiotics (six trials, odds ratio 0.46, 95% confidence interval 0.30 to 0.69). Combining topical and systemic antibiotics was not more effective than topical antibiotics. Topical quinolones were more effective than non-quinolones (five trials, odds ratio 0.26, 95% confidence interval 0.16 to 0.41). No difference in the effectiveness of topical antibiotics and topical antiseptics was found (three studies, odds ratio 1.34, 95% confidence interval 0.64 to 2.81). Some topical antibiotic combinations may be more effective than others in resolving otorrhea. Rates of adverse drug events were low and equal between groups.

REVIEWER'S CONCLUSIONS

Treatment of CSOM with aural toilet and topical antibiotics, particularly quinolones, is effective in resolving otorrhea and eradicating bacteria from the middle ear. Longterm outcomes such as preventing recurrences, closure of tympanic perforation and hearing improvement need to be further evaluated.

Altered expression of epithelial cell surface glycoconjugates and intermediate filaments at the margins of mucosal wounds

Alterations in cell to cell adhesion are necessary to enable the type of cell movements that are associated with epithelial wound healing and malignant invasion. Several studies of transformed cells have related epithelial cell movement to changes in the cell surface expression of the carbohydrate structures represented by the ABO blood group antigens and, in particular, by Lewis antigens and their biosynthetic precursors. To study further the relationship between cell surface carbohydrates and keratinocyte cell movement, experimental wounds were created in human oral mucosa and examined by immunohistochemical methods for their expression of selected cytokeratins (K5, K16, K19), basement membrane components (laminin alpha5 and gamma2-chains, BP180, collagen IV and collagen VII), and blood group antigen precursor structures Le(x), sialosyl-Le(x), Le(y), H antigen, N-acetyllactosamine, and sialosyl-T antigen. The changes induced by wounding in the expression of collagen IV, laminin gamma2-chain (laminin-5), and laminin alpha5-chain were similar to those found in skin wounds and served to define the region of epithelial movement. This region was found to show a marked increase in staining for both Lewis antigen Y (Le(y)) and H blood group antigen, and decreased staining of Le(x), thus indicating an upregulation in wounded epithelium of the fucosyltransferases responsible for the synthesis of the H antigen. The changes in carbohydrate expression extended beyond the wound margin into the nonwounded epithelium, a pattern of expression similar to K16, which was also strongly upregulated in both the outgrowth and the adjacent nonwounded epithelium. These findings provide further support for an influence of such carbohydrate structures on the migratory behavior of epithelial cells.

A pilot investigation into the use of vestibulometric measures in predicting neural pathways in relation to vibrotactile stimulation

Research in the use of vibrotactile devices has focused predominantly on the vibrotactile receptor system within the skin. There is little research relating to the neural pathways and the central processing of information transmitted to the cortex as a result of vibrotactile stimulation. This pilot study that considers the use of vestibulometric measures in predicting the neural pathways. Three measures of vestibular function were undertaken: saccadic eye movement, smooth pursuit and optokinetic nystagmus. Ten normally hearing adults, with no previous history of vestibular dysfunction, were tested using an ICS computer based vestibular testing system. All subjects were tested in four situations: baseline, wearing vibrotactile device with stimulation, vibrotactile device without stimulation and repeated baseline. Five subjects demonstrated a significant change in vestibular measures, four related to measure of optokinetic nystagmus and two in relation to smooth pursuit. There is a demonstrated difference in vestibular function which supports the need for further investigation.

Effect of implant dose/volume and surgical resection on survival in a rat glioma brachytherapy model: implications for brain tumor therapy

OBJECTIVE

This study sought to investigate the effects of implant dose/volume and surgical resection on survival in a rat glioma brachytherapy model. Two doses were investigated to determine a suitable therapeutic range.

METHODS

We performed two experiments. Three treatment groups and one control group of male F-344 rats bearing 9L brain tumors 12 days after tumor inoculation were used in the first experiment. Day 12 tumors were an average of 4 to 6 mm in diameter. Animals treated with brachytherapy received a tumor dose of 80 Gy delivered to a 5.5-mm-radius volume. Total macroscopic tumor removal was achieved by microsurgical techniques. A subsequent experiment compared the survival of tumor-burdened rats treated with an implant dose of 60 Gy delivered to a 5.5-mm-radius volume with a control group.

RESULTS

Surgery alone produced an increased life span of 28.6% over control animals treated with sham surgery and dummy seed implants, a statistically significant increase in survival (P = 0.0023, log-rank test). Brachytherapy alone produced the most significant increase in survival over control animals (P = 0.0001, log-rank test; median survival not attained with an implant dose of 80 Gy delivered to a 5.5-mm-radius volume; and P = 0.0001, increased life span 121% with an implant dose of 60 Gy delivered to a 5.5-mm-radius volume). This was not improved by the addition of surgical tumor removal.

CONCLUSION

We have demonstrated a relationship between implant dose/volume and survival of tumor-burdened rats in this model that is not improved by the addition of tumor removal. Implications for brain tumor brachytherapy are discussed.

Audio-vestibular manifestations of Chiari malformation and outcome of surgical decompression: a case report

Sensorineural hearing loss, tinnitus, dizziness and ataxia are recognised symptoms associated with Chiari malformations but they are rarely the presenting complaints. Patients with such symptoms are frequently referred to otolaryngologists and audiological physicians. We report a case of a 13-year-old girl who presented complaining of tinnitus and impaired hearing, and was subsequently diagnosed as having a type I Chiari malformation. Pure tone audiogram showed a mild hearing impairment on the left side and the speech audiogram was normal. Auditory brain stem responses and the electronystagmography were abnormal. The patient underwent posterior fossa decompression following which her tinnitus disappeared, the hearing problem recovered and some of the abnormal electrophysiological parameters were corrected.

Measurement of oxygen concentration in delivery systems used for hyperbaric oxygen therapy

Efficient delivery of oxygen is important during hyperbaric oxygen therapy. We compared two systems in common use, and developed a method to ensure that O2 delivery was adequate during treatment. The systems were a demand valve system with an oral-nasal mask, and a continuously ventilated hood. Five groups were studied over two different time periods, and a further trial was undertaken to examine exhaled O2 levels. The results showed that an acceptable Fio2 could be reliably achieved only with the continuously ventilated hood system or when trained staff supervised their colleagues using the demand system. Inasmuch as the oral-nasal mask system is the standard equipment for the North Sea diving industry, this work shows the importance of ensuring that the correct dose of O2 is delivered. The study indicates, however, that identification of the problem does not always allow a complete solution, and that a hood-based system is more reliable.

Essential skills for purchasing--the views of directors of public health and health authority chief executives

Since the NHS reforms, health authorities have been purchasing health care and have been advised that public health considerations must inform all NHS activities, and that the Director of Public Health must be supported by a team of qualified support staff. This survey of directors of public health and health authority chief executives in England shows the skills currently available to support health authority purchasing, and the perceived importance of this wide range of skills to the purchasing process. Future models of purchasing will need to ensure access by purchasers to public health and multi-disciplinary advice.

A prevalence study of ear problems in school children in Kiambu district, Kenya, May 1992

Information on the prevalence of hearing impairment and related ear pathologies in children in sub-Saharan Africa is scarce. A pilot study for a clinical trial of simple treatments for chronic suppurative otitis media (CSOM) in school children in Kiambu district, Kenya, provided information on the prevalence of hearing impairment and ear pathologies. Five-thousand-three-hundred-sixty-eight children from 57 randomly chosen primary schools in Kiambu district were examined. Simple otoscopy was performed by clinical officers with specialty training in ENT, and hering testing was performed by trained nurses, using a hand held field audiometer. Microbiological specimens were obtained from those children with CSOM. Five-point-six percent of the children had a hearing impairment of > 30 dB HL in one or both ears, with 2.2% having bilateral hearing impairment. Two-point-four percent had at least one perforated tympanic membrane, and 1.1% had CSOM. Eight-point-six percent of the children had wax obstructing the tympanic membrane. There is evidence of a relationship between hearing impairment and both CSOM and wax obstructing the tympanic membrane. The most common organisms found were Pseudomonas spp. (34%), Proteus spp. (34%) and Eschericia coli (19%). These results are comparable with other studies in Africa and indicate a considerable burden of ear disease in Kiambu district, Kenya.

Responsibilities and resources of on-call public health doctors

We investigated the resource available for public health doctors to carry out statutory responsibilities out-of-hours by a postal questionnaire survey of consultants in communicable disease control (CsCDC) in England and Wales. The questionnaire requested details of local District Health Authority (DHA) population profile, major incident and outbreak policies, the background of the CCDC, out-of-hours communication, access and resources, reference materials and medical equipment carried by the public health doctor on duty. The CsCDC from 96% (121/126) DHAs in England and Wales responded. Whilst 85% (101/119) of public health doctors carried policies on infectious disease when on duty, only 28% (32/116) carried policies on dealing with chemical incidents and 25% (28/111) carried the District policy to deal with radiation hazards. Twenty-six per cent (32/121) of public health physicians had no access to their District headquarters. There is a wide variation in the standard of resources available to on-call public health doctors in England and Wales; following Department of Health and Department of the Environment guidance, Health Authorities need to ensure that they have adequate arrangements in the event of any major incident or outbreak.

Membrane-associated forms of the beta A4 amyloid protein precursor of Alzheimer's disease in human platelet and brain: surface expression on the activated human platelet

The amyloid protein precursor (APP) of Alzheimer's disease (AD) is abundantly expressed in platelets, where its primary function remains undetermined. As an integral transmembrane protein, the release of APP from the membrane may be a critical event in AD. We examined the association of APP with human platelet membranes using a combination of alkali treatment and immunoprecipitation of the carboxyl-terminus of APP. Most of the platelet membrane-associated APP (APPMem) with molecular mass of 100 to 130 kD is removed with alkali treatment and is also truncated at the carboxyl-terminus. APPMem is present at least in part on the surface of the platelet. The full-length transmembrane form of APP, as a 140- to 150-kD minor species, is alkali resistant and is also present on the plasma membrane. In contrast, most of the APPMem from brain is full-length (possessing the carboxyl-terminus) with a molecular mass of 105 to 130 kD and is resistant to alkali treatment. Immunoelectron microscopy shows platelet APP to be localized to the alpha-granule. Activation of platelets results in a threefold increase in surface APP detectability. In plasma, the 130-kD APP-reactive band is increased in AD. We find that in the gray platelet syndrome, platelets contain reduced amounts of APP, with a corresponding reduction in plasma APP levels, suggesting that platelets are the major source of plasma APP. Our studies also identify an interaction of APP with platelet membranes which differs from that found in the brain, and raise the possibility of a receptor for APP in platelet membranes. Quantitative differences in the amounts of APPMem in platelets compared with brain also indicate regulation of the pathways that determine the cleavage of APP near its transmembrane domain. These pathways are a therapeutic target in AD, and may be easily amenable to investigation in platelets.