A placebo-controlled study of liposome-mediated gene transfer to the nasal epithelium of patients with cystic fibrosis

Cystic fibrosis (CF) is a common, serious, inherited disease. The major cause of mortality in CF is lung disease, due to the failure of airway epithelial cells to express a functional product of the cystic fibrosis transmembrane conductance regulator (CFTR) gene. A potential treatment for CF lung disease is the expression of CFTR in the airways following gene transfer. We have undertaken a double-blinded, placebo-controlled, clinical study of the transfer of the CFTR cDNA to the nasal epithelium of 12 CF patients. Cationic liposomes complexed with plasmid containing the human CFTR cDNA were administered to eight patients, whilst four patients received placebo. Biopsies of the nasal epithelium taken 7 days after dosing were normal. No significant changes in clinical parameters were observed. Functional expression of CFTR assessed by in vivo nasal potential difference measurements showed transient correction of the CF chloride transport abnormality in two patients (15 days after dosing in one patient). Fluorescence microscopy demonstrated CFTR function ex vivo. In cells from nasal brushings. In total, evidence of functional CFTR gene transfer was obtained in six out of the eight treated patients. These results provide proof of concept for liposome-mediated CF gene transfer.

Endoscopic diagnosis of pyriform fossa lymphoma

Many endoscopists do not inspect the gastrointestinal tract superior to the cricopharyngeus, despite the fact that gastrointestinal symptoms (dysphagia, odynophagia and chest pain) can be produced by glottic and supraglottic lesions. A case of incoordinate swallowing secondary to a right-sided pyriform fossa lymphoma diagnosed at gastroscopy is presented.

Life expectancy in men who have never smoked and those who have smoked continuously: 15 year follow up of large cohort of middle aged British men

OBJECTIVE

To estimate the life expectancy in a representative sample of men who have never smoked and of those who have smoked all their adult lives.

DESIGN

15 year follow up of a large representative cohort of British men in the British regional heart study and use of national mortality statistics for 1992.

SUBJECTS

7735 middle aged British men aged 40-59 at the time of screening (between 1978 and 1980).

MAIN OUTCOME MEASURES

Mortality from all causes and from smoking related causes.

RESULTS

1624 men had never smoked at the time of screening and did not take up smoking during the study. 127 of them died during follow up. 3151 men began smoking before they were 30 and were still smoking at the time of screening. Of these, 751 had stopped smoking five years after screening; they were excluded from the analysis five years after the date they had stopped. 560 of the lifelong smokers died during follow up. When study estimates were combined with those from national mortality statistics for men aged 20-40, only an estimated 42% (95% confidence interval 36% to 50%) of lifelong smokers alive at the age of 20 would be alive at 73, compared with 78% (74% to 82%) of lifelong non-smokers.

CONCLUSION

These estimates present the effects of smoking on mortality in a way that is easily communicated to patients and the general public in health promotion initiatives.

Missed opportunities for the prevention of cardiovascular disease among British hypertensives in primary care

BACKGROUND

High-risk strategies for the prevention of cardiovascular disease (CVD) among hypertensive patients require knowledge of the prevalence and interaction of modifiable risk factors to ensure effective targeting of interventions. Comparatively little is known of risk-factor profiles and their modification among hypertensives in primary care.

AIM

The present study was designed to explore relationships between patients' knowledge of CVD risk factors, their perception of personal risk and health behaviours, and their use of lifestyle interventions.

METHOD

A cross-sectional survey of 2676 men and women with mild to moderate hypertension (diastolic blood pressure 95-115 mmHg), and their general practitioners, recruited from 1044 general practices throughout the UK, was conducted.

RESULTS

Levels of modifiable risk factors were high, although there was considerable variation by age and sex; most (98.5%) patients had at least one additional CVD risk factor. A lower standard of living was associated with a higher prevalence of 'unhealthy' behaviours. Out of those with a current lifestyle problem, 85% of obese patients, 59% of smokers, 47% of excess drinkers, 49% of those with dietary risk factors and 32% of inactive patients claimed to have adopted healthier behaviours within the past 3 months. Older subjects and those with a lower standard of living were less likely to acknowledge risks, and those who did were less likely to report improving their lifestyles. While 71% of patients recalled receiving lifestyle advice, the coverage and targeting of specific interventions was generally poor. Overall, 60% of the sample had received advice on weight control, 47% on diet, 38% on exercise, 38% on smoking and 36% on alcohol. Women and older people were less likely to be given relevant counseling, and there was no evidence of targeting with respect to subjects' social class, level of hypertension or duration of diagnosis.

CONCLUSION

Lifestyle interventions are welcomed and are viewed as helpful by patients receiving them. Potential health gains among high-risk hypertensives are being lost because of poor targeting and coverage of those at greatest risk.

The two-way paradigm of transplantation immunology

The events following organ transplantation require a reciprocal cell interaction which includes both the conventional host-versus-graft reaction and a graft-versus-host component. With all successful transplantation, both graft and recipient become genetic composites. Where donors were available, chimerism has been confirmed in 30-year kidney-recipient survivors, as well as in several liver and lung recipients. A majority of liver recipients have been able to acquire an immunosuppressant-free state after 10-year survival. Animal models suggest that donor-derived cells may exert a tolerogenic effect.

Short-term clinical measurement: acute severe episodes

Clinical measurements are widely used to evaluate both the severity and outcome of acute and severe episodes of wheeze. A large number of clinical scores have been produced, rating the severity from 0 to 3 or 4. The heterogenicity of these clinical scores, their subjective nature, shown by the poor interobserver agreement and the poor correlation with oximetry, make comparison between trials very difficult. Other clinical indicators, such as duration of hospitalization, maximum inspired oxygen fraction (FI,O2) and need for additional treatment, may be confounded by factors other than the wheezing episode. In contrast, provided standardized methods are used, respiratory rate, oxygen saturation and arterial blood gases are objective measurements and valuable tools. In order to evaluate the effect of interventions it is necessary to undertake a systematic evaluation of clinical variables: Which variables have the least interobserver error? Which variables are the most discriminant? New techniques, such as acoustic measurement, cough recording, respiratory inductive plethysmography (quantifying thoracoabdominal asynchrony and derived timing indices) should be developed and validated.

Bowel preparation for colonoscopy: a randomized prospective trail comparing sodium phosphate and polyethylene glycol in a predominantly elderly population

Many patients find polyethylene glycol-based preparations (PEG) difficult to take because of the large volume of fluid they are required to consume. One hundred and sixteen predominantly elderly patients were randomized to receive either sodium phosphate (n = 61) or PEG (n = 55) bowel preparations before colonoscopy. Patients with a history of symptomatic ischaemic heart disease or cerebrovascular disease in the preceding 6 months, severe liver disease or heart failure, or serum creatinine above 200 micrograms/L were excluded from the study. Each patient filled in a questionnaire about the bowel preparation prior to the procedure. The colonoscopists, who were not aware which preparation had been used, were asked to complete a questionnaire about the quality of the bowel preparation after the procedure. The patients found the sodium phosphate preparation slightly more tolerable than PEG. Side effects were slightly more common with sodium phosphate. Neither difference was statistically significant. However, 91% of patients who had previously had PEG found sodium phosphate easier to take. Approximately 25% of patients in each group experienced at least one episode of incontinence. The colonoscopists found no difference in the overall quality of the bowel preparation. The amount of fluid in the colon was greater in patients prepared with PEG. As expected, patients taking sodium phosphate developed hyperphosphataemia (mean phosphate level before colonoscopy 1.56 mmol/L, normal 0.8 -1.3). They also had a lower mean serum potassium level (3.8 mmol/L) than the PEG group (4.2 mmol/L). However, there were no clinically significant consequences. Sodium phosphate was a safe and effective bowel preparation for colonoscopy in this carefully selected group of patients. It was preferred by patients who had previously had PEG. Many elderly patients were found to develop faecal incontinence, irrespective of the type of bowel preparation used.

Route of BCG administration in possums affects protection against bovine tuberculosis

The Australian brushtail possum (Trichosurus vulpecula) is the major wildlife reservoir of Mycobacterium bovis in New Zealand. Control of bovine tuberculosis in farmed animals requires measures to reduce the transmission of M. bovis from wildlife. Possums were vaccinated with BCG intranasally by aerosol spray, orally or subcutaneously to compare the efficacy of these three routes on protection against challenge with virulent M. bovis. Possums vaccinated with BCG by the intranasal or subcutaneous routes had a marked reduction in severity of disease compared to possums which had been unvaccinated or orally vaccinated. The severity of the disease was assessed by changes in body weight and pathology. BCG vaccination by all three routes resulted in reduced dissemination of M. bovis to the spleen and liver following challenge. Intranasal and oral BCG vaccination induced lower mean peripheral blood lymphocyte blastogenic responses to bovine PPD than subcutaneous vaccination, indicating that these responses did not correlate well with protection from the disease. Given a suitable delivery system, aerosol vaccination of possums, used in conjunction with other control measures, may be a suitable method of reducing the spread of M. bovis from wildlife to domestic animals.

Growth factors as mediators of androgen action during the development of the male urogenital tract

Studies on the developing prostate and SV suggest that androgens act via mesenchymal AR to elicit synthesis and secretion of various autocrine and paracrine factors that regulate epithelial and stromal growth and differentiation. Clearly, the global regulation of epithelial growth and ductal branching morphogenesis is a complex multifactorial process involving the interplay of many diffusible factors (both positive and negative regulators), extracellular matrix molecules, cell-surface receptors for growth factors, receptors for extracellular matrix molecules, and matrix-degrading enzymes. Future progress will certainly be dependent upon the utilization of appropriate, biologically relevant models to examine the respective roles of various growth factors in the growth and development of androgen target organs.

Regional differences in cardiovascular risk factor prevalence in Tasmania: are they consistent with the increased cardiovascular mortality?

BACKGROUND

The death rate from cardiovascular disease in Tasmania has been among the highest in Australian States for a number of years. The North-West (NW) and Northern regions of Tasmania account for most of the increased mortality.

AIMS

To determine the prevalence of cardiovascular risk factors in the North and NW regions of Tasmania and to ascertain whether any differences are consistent with the regional patterns of mortality for ischaemic heart disease (IHD) within the State.

METHODS

The design of the study was almost identical to the previous National Heart Foundation (NHF) Risk Factor Prevalence Survey conducted in 1989. The subjects, aged 20-69 years, were randomly selected from the Electoral Roll with 1146 subjects participating in the North and 1219 in the NW. Subjects answered a detailed questionnaire and then underwent a brief physical examination with venipuncture for blood lipids. Hobart data from the NHF Risk Factor Prevalence Survey in 1989 were used as an estimate of risk factor prevalence in the Southern region.

RESULTS

In both males and females, mean systolic blood pressure was significantly higher in the NW than the South which was in turn higher than the North. Mean serum cholesterol levels in males were higher in the NW than the North. Smoking behaviour was similar in males and females in all regions. Males and females in the NW and North were more inactive than those in the South. Similar proportions in all regions were on either 'no specific' or 'fat modified' diets. Body mass index in males and females was higher in the NW and North but waist to hip ratios failed to show a consistent trend.

CONCLUSIONS

While the NW has an unfavourable risk factor profile compared with the South, the North does not. The risk factor data are broadly consistent with, but unlikely to be sufficient to explain fully, the regional differences in mortality from IHD.

The influence of brain acetaldehyde on oxidative status, dopamine metabolism and visual discrimination task

The toxic effect of acetaldehyde on brain oxidative capacity and dopamine metabolism has been investigated in rat brains after a single intraperitoneal injection of acetaldehyde (5 mmol/kg) and the results compared with those from chronically ethanol fed rats. Acetaldehyde was present in rat brain 120 hr after a single dose of acetaldehyde, confirming that it is able to cross the blood-brain barrier. Brain catalase increased significantly after acetaldehyde or chronic ethanol administration although there were no other significant changes in the total brain activity of superoxide dismutase, glutathione peroxidase or glutathione reductase. Dopamine turnover was increased in both experimental groups. The acute dose of acetaldehyde reduced the ability of the rats to relearn a computer visual discrimination task.

Protection of cattle from bovine tuberculosis by vaccination with BCG by the respiratory or subcutaneous route, but not by vaccination with killed Mycobacterium vaccae

Groups of cattle were vaccinated either with BCG Pasteur by the intratracheal or subcutaneous route or with killed Mycobacterium vaccae by the intradermal route and challenged intratracheally 54 days later with Mycobacterium bovis. Vaccination with BCG resulted in fewer animals developing tuberculous lesions and in a reduction in the number of lesions in the diseased animals compared with the unvaccinated group and the group vaccinated with M vaccae. None of the nine animals vaccinated intratracheally with BCG developed any tuberculous lung lesions after challenge with M bovis, but two of the nine animals from each of the groups dosed subcutaneously with low and medium doses of BCG developed lung lesions. There was little difference in protection against the M bovis challenge between the animals receiving the low dose (10(3) colony forming units, cfu) or medium dose (10(5) cfu) of subcutaneous BCG, but the medium dose of BCG produced stronger cell-mediated immune responses to bovine purified protein derivative (PPD) after vaccination. Vaccination intradermally with 10(9) heat-killed M vaccae did not protect cattle against an experimental challenge with M bovis and induced only weak cell-mediated immune responses to bovine PPD.