Prostacyclin synthase expression is decreased in lungs from patients with severe pulmonary hypertension

Prostacyclin is a powerful vasodilator and inhibits platelet adhesion and cell growth. We hypothesized that a decrease in expression of the critical enzyme PGI2 synthase (PGI2-S) in the lung may represent an important manifestation of pulmonary endothelial dysfunction in severe pulmonary hypertension (PH). Immunohistochemistry and Western blot analysis were used to assess lung PGI2-S protein expression, and in situ hybridization was used to assess PGI2-S mRNA expression. In the normal pulmonary circulation (n = 7), PGI2-S was expressed in 48% of small, 67% of medium, and 76% of large pulmonary arteries as assessed by immunohistochemistry. PPH (n = 12), cirrhosis-associated (n = 4) and HIV-associated PH (n = 2) lungs exhibited a marked reduction in PGI2-S expression, involving all size ranges of pulmonary arteries. Vessels with concentric lesions showed complete lack of PGI2-S expression. Congenital heart (n = 4) and CREST (n = 2) cases exhibited a more variable immunohistological pattern of PGI2-S expression. These results were complemented by in situ hybridization and Western blots of representative lung samples. We conclude that the different sizes of the pulmonary arteries express PGI2-S differently and that the loss of expression of PGI2-S represents one of the phenotypic alterations present in the pulmonary endothelial cells in severe PH.

Do people who apply sunscreens, re-apply them?

Little is known about Australians' practices regarding sunscreen re-application, yet it is routinely advised and has recently been shown to increase the protective efficacy of sunscreens. A baseline survey of sunscreen application and re-application behaviour was therefore conducted in a Queensland community using a standard self-administered questionnaire. Other sun protection methods were also assessed. Of a total of 669 adult respondents, 76% reported using sunscreen and of those, 61% reported re-applying sunscreen. Significantly more women (66%) than men (55%) reported re-applying sunscreen and re-application was inversely related to age (79% of those aged less than 45, 57% of those 45-59 years old and 46% of those over 60 years). Increased rates of re-application were reported during times of increased sun exposure, as well as by those with greater knowledge of the benefits of sunscreen re-application. A recent personal history of non-melanoma skin cancer did not lead to improved rates of sunscreen application, sunscreen re-application, or most forms of physical sun protection.

An evaluation of pharmaceutical management and budget holding in Pegasus Medical Group

AIMS

To describe and evaluate pharmaceutical management, including budget holding, in Pegasus Medical Group (Pegasus), to determine savings being achieved, to analyse variation in prescribing behaviour and to compare the findings with national and international experience.

METHODS

Trends in pharmaceutical expenditure of the 150 Pegasus' 208 members who had a continuous prescribing record for the three years ending December 1996 were compared with national trends. Expenditure per member, per consultation and per item were also analysed.

RESULTS

Pegasus has implemented a comprehensive and classical pharmaceutical management strategy. This includes active personalised feedback, information sharing, peer review groups and information system development, all within an incentive framework of retained savings for new services. Although about 5% savings of total pharmaceutical expenditure were identified by the above method, the real level may be higher. Wide variation between members in their prescribing behaviour was explained almost entirely by the volume rather than the price of the drugs prescribed. Targeting of the volume issue is therefore likely to have a much more significant effect in reducing inappropriate variation.

CONCLUSION

The results indicate that the achievements of Pegasus, as for other independent practitioner associations, go far beyond the modest level of pharmaceutical savings achieved. These include the development of a substantial infrastructure, peer review processes, new internal and external relationships and accountability for the management of both quality and cost in what may be styled clinical governance. Such achievements put Pegasus and other independent practitioner associations into a strong position to take on new initiatives including integration with secondary care.

Do people who apply sunscreens, re-apply them?

Little is known about Australians' practices regarding sunscreen re-application, yet it is routinely advised and has recently been shown to increase the protective efficacy of sunscreens. A baseline survey of sunscreen application and re-application behaviour was therefore conducted in a Queensland community using a standard self-administered questionnaire. Other sun protection methods were also assessed. Of a total of 669 adult respondents, 76% reported using sunscreen and of those, 61% reported re-applying sunscreen. Significantly more women (66%) than men (55%) reported re-applying sunscreen and re-application was inversely related to age (79% of those aged less than 45, 57% of those 45-59 years old and 46% of those over 60 years). Increased rates of re-application were reported during times of increased sun exposure, as well as by those with greater knowledge of the benefits of sunscreen re-application. A recent personal history of non-melanoma skin cancer did not lead to improved rates of sunscreen application, sunscreen re-application, or most forms of physical sun protection.

Minority enrichment programs at the New Jersey Medical School: 26 years in review

In 1971 the New Jersey Medical School formed a task force to address the training of physicians from minority and disadvantaged backgrounds, and in 1972 the Students for Medicine Program (SMP) was launched. The program, one of the first of its kind, provided previews of college science courses to help minority students develop their noncognitive skills and make the transition to medical school. The school has also established other minority programs. The programs have been designed to form a health careers pipeline for college-bound students, beginning in the eighth grade. Grade-specific summer experiences, as well as year-round monthly workshops, are offered to all participants. The workshops for pre-college and college students and their parents are designed to strengthen students' academic skills, address issues such as self-esteem, provide exposure to health professions, and increase parents' knowledge and involvement. From 1972 to 1998, there had been 1,722 participants in the pre-college, 1,875 in the college, and 683 in the prematriculation programs, respectively. They were from the inner city, most of them African American, but with a growing number of Hispanics. From 1987 to 1994, 36% of the SMP participants entered health professions schools. In 1996, the medical school created the New Jersey Partnership for Health Professions Education, a collaboration of high schools, universities, community-based organizations, the federal government, and the health professions schools. It works to strengthen the medical school's "pipeline" for underrepresented minority students while eliminating competition among programs for the same students and simultaneously developing a larger pool.

Minority enrichment programs at the New Jersey Medical School: 26 years in review

In 1971 the New Jersey Medical School formed a task force to address the training of physicians from minority and disadvantaged backgrounds, and in 1972 the Students for Medicine Program (SMP) was launched. The program, one of the first of its kind, provided previews of college science courses to help minority students develop their noncognitive skills and make the transition to medical school. The school has also established other minority programs. The programs have been designed to form a health careers pipeline for college-bound students, beginning in the eighth grade. Grade-specific summer experiences, as well as year-round monthly workshops, are offered to all participants. The workshops for pre-college and college students and their parents are designed to strengthen students' academic skills, address issues such as self-esteem, provide exposure to health professions, and increase parents' knowledge and involvement. From 1972 to 1998, there had been 1,722 participants in the pre-college, 1,875 in the college, and 683 in the prematriculation programs, respectively. They were from the inner city, most of them African American, but with a growing number of Hispanics. From 1987 to 1994, 36% of the SMP participants entered health professions schools. In 1996, the medical school created the New Jersey Partnership for Health Professions Education, a collaboration of high schools, universities, community-based organizations, the federal government, and the health professions schools. It works to strengthen the medical school's "pipeline" for underrepresented minority students while eliminating competition among programs for the same students and simultaneously developing a larger pool.

Randomized trial of "slow" versus "fast" feed advancements on the incidence of necrotizing enterocolitis in very low birth weight infants

OBJECTIVE

To determine whether the rate of feed advancement affects the incidence of necrotizing enterocolitis (NEC).

STUDY DESIGN

Prospective randomized controlled trial involving 185 formula-fed infants with birth weight 501 to 1500 g and gestational age </=34 weeks. Infants were randomized into 2 groups: "slow" (n = 98), who received 15 cc/kg/d increments (a 10-day schedule to full feeds) and "fast" (n = 87), who received 35 cc/kg/d increments (a 5-day schedule to full feeds) of Similac Special Care 20 cal/oz. Feeds were increased only if well tolerated as defined by a protocol.

RESULTS

The incidence of NEC (Bell stage >/=II) was similar in both groups (slow 13% and fast 9%, P =.5). The incidence of perforation (Bell stage III) was also similar in both groups (slow 4% and fast 2%, P =.8). Feeds were started at a comparable postnatal age in both groups (median age: slow 5 days and fast 4 days, P =.9). Although the neonates in the fast group attained full enteral intake earlier (median days [25th and 75th percentiles]: slow 15 [12, 21] and fast 11 [8, 15], P <.001) and regained their birth weight earlier (slow 15 [11, 20] and fast 12 [8, 15], P <.05), their ages at discharge were not statistically different (slow 47 [31, 67] and fast 43 [29, 62], P =.3)

CONCLUSIONS

A greater than twofold difference in the rate of feed advancement from 15 cc/kg/d to 35 cc/kg/d did not affect the incidence of NEC >/= stage II. Factors other than feed advancement appear to be more important in the pathogenesis or progression of NEC.

Telephone or face-to-face interviews?: a decision made on the basis of a pilot study

De Vaus (1991) highlights five main considerations that may be key factors in decisions about whether to use telephone or face-to-face interviews for survey work: response rates, ability to produce representative samples, effects on interview schedule design, quality of responses and implementation problems. De Vaus' discussion of these five issues is outlined at the start of this article. The five issues are then applied to the experiences of researchers conducting a study on continence care. Description and discussion of pilot interviews, which explored both interview modes, are followed by a similar examination of the main study which employed telephone interviews. Ideas in this discussion are supported and challenged by reference to other publications on the subject of telephone and face-to-face interviews. The success of the decision to use telephone interviews in the main study is evaluated and recommendations are made.

Composition and function of peripheral blood stem and progenitor cell harvests from patients with severe active rheumatoid arthritis

High-dose chemotherapy with autologous stem cell rescue has been proposed as an intensive therapy for severe rheumatoid arthritis (RA). In view of previous observations of abnormal haemopoiesis in RA patients, the composition and function of peripheral blood stem cell harvests (PBSCH) was investigated. Compared with PBSCH from healthy allogeneic donors mobilized with the same dose of G-CSF (filgrastim; 10 microg/kg/d, n = 14), RA PBSCH (n = 9) contained significantly fewer mononuclear cells (375 v 569 x 10(6)/kg, P = 0.03) and CD34+ cells (2.7 v 5.8 x 10(6)/kg, P = 0.003). However, there were increased proportions of CD14+ cells (P = 0.006) and CD14+ CD15+ cells (the phenotype of previously described 'abnormal' myeloid cells, P = 0.002) in the RA PBSCH which translated into 3.5- and 7-fold increases respectively on a per CD34+ cell basis. There were no differences in T-cell activation status as judged by proportions of CD4+ and CD8+ expressing CD45RA, CD45RO, HLA-DR and CD28 (RA PBSCH, n = 7, donor PBSCH, n = 5, P = 0.2-0.7). Phytohaemagglutinin responses determined fluorocytometrically with induction of CD69 expression were reduced in CD4+ and CD8+ cells following filgrastim administration in 3/3 RA patients tested. Compared with bone marrow as a potential source of CD34+ cells, PBSCH contained 11-fold more T cells (P < 0.0005), 8-fold more B cells (P < 0.0005) and 4-fold more monocytes (P = 0.02). In short-term methylcellulose culture there were no differences in colony counts (CFU-GM, CFU-GEMM, BFU-E) per CD34+ cell from PBSCH from RA patients (n = 11) and healthy donors (n = 10). Long-term culture initiator cells were cultured successfully from cryopreserved PBSCH from RA patients (n = 9). In conclusion, PBSCH from RA patients differed significantly in composition from normal individuals, but in vitro studies support normal stem and progenitor cell function. Changes in T-cell function occur during mobilization in RA patients. This work provides reassurance for the use of PBSCH as haematological rescue and baseline data for clinical trials of graft manipulation strategies in patients with RA.

Factors affecting practice nurse involvement in follow-up care of patients following myocardial infarction

BACKGROUND

Preventive care can reduce the morbidity and mortality of patients following myocardial infarction. Recent evidence has shown that such care is not being provided effectively. The involvement of practice nurses has been proposed as a means of improving the completeness of follow-up and the quality of preventive care.

OBJECTIVES

We aimed to determine the extent to which follow-up care for people discharged from hospital after a myocardial infarction is currently being undertaken by practice nurses and to assess the factors influencing the provision of such care and the nurses' attitudes towards this extended role.

METHOD

Postal questionnaires were sent to 183 practice nurses working in general practices in the Southampton and South-West Hampshire Health District; 121 nurses responded (66%), representing 58 out of 64 practices surveyed (91%).

RESULTS

The majority of responding practice nurses (55%, 95% CI 47-64%) had hospital experience of caring for patients with ischaemic heart disease, and most (83%, 95% CI 76-89%) believed that they played a key role in follow-up care of patients following myocardial infarction. In the absence of external support from a cardiac liaison nurse, few nurses (26%, 95% CI 16-41%) provide such care at present and only 21% work in practices with a register of myocardial infarction patients. Factors predicting the provision of follow-up care are having adequate time (odds ratio 4.59, 95% CI 1.66-12.7), the support of a cardiac liaison nurse (odds ratio 3.07, 95% CI 1.28-7.34) and GP colleagues (odds ratio 3.38, 95% CI 1.38-8.23), training in consultation skills (odds ratio 7.25, 95% CI 2.08-25.3), fundholding (odds ratio 3.11, 95% CI 1.26-7.69) and the confidence and knowledge of the practice nurse (odds ratios and 95% CIs respectively: 2.84, 1.18-6.83 and 2.80, 1.13-6.89).

CONCLUSION

Most practice nurses are enthusiastic and have some of the necessary experience to provide follow-up care for patients who have experienced a myocardial infarction. Yet few currently provide it. The most important organizational incentives for providing such care are further training and the support of GPs and the cardiac liaison nurse.

Primary pulmonary hypertension between inflammation and cancer

We believe that the monoclonal cell expansion in primary pulmonary hypertension is the result of autonomous growth of stem cell-like endothelial cells, whereas the polyclonal proliferation in secondary pulmonary hypertension occurs as a response of endothelial cells to exogenous stimuli (like viral infection or high shear stress). In this context, we propose that different transcriptional and translational events govern the growth and expansion of monoclonal when compared with polyclonal pulmonary endothelial cells. The availability of antibodies directed against specific tyrosine kinase proteins involved in vasculogenesis/angiogenesis now permits the identification and localization of the components of such a misguided angiogenesis cell proliferation program in the pulmonary hypertensive vascular lesions.

Induction of phosphodiesterases 3B, 4A4, 4D1, 4D2, and 4D3 in Jurkat T-cells and in human peripheral blood T-lymphocytes by 8-bromo-cAMP and Gs-coupled receptor agonists. Potential role in beta2-adrenoreceptor desensitization

In this study, a potential mechanism of beta2-adrenoreceptor desensitization has been explored that is based upon the enhanced degradation of cAMP by phosphodiesterase (PDE). Pretreatment of Jurkat T-cells with 8-bromo cAMP (8-Br-cAMP) or prostaglandin E2 increased PDE3 and PDE4 activity in an actinomycin D- and cycloheximide-sensitive manner. This effect was associated with increased expression of HSPDE3B, HSPDE4A4, HSPDE4D1, HSPDE4D2, and HSPDE4D3 mRNA transcripts. Western analysis reproducibly labeled a band of immunoreactivity in vehicle-treated cells that corresponded to HSPDE4A4 (125 kDa). Although the intensity of this band was unchanged in cells treated with 8-Br-cAMP, additional 68-72-kDa proteins (HSPDE4D2, HSPDE4D1) were labeled that were not detected after vehicle. Similar results were obtained with T-lymphocytes exposed to 8-Br-cAMP and fenoterol. However, in those experiments HSPDE4A4 and HSPDE4D1 appeared to be equally expressed in vehicle- and treated cells, whereas HSPDE4D2 (72 kDa) was detected only after 8-Br-cAMP. The up-regulation of PDE activity in Jurkat T-cells abolished the ability of isoproterenol to elevate cAMP, which was partially reversed by the non-selective PDE inhibitor, 3-isobutyl-1-methylxanthine, and by the PDE3 and PDE4 inhibitors, Org 9935 and rolipram, respectively. Collectively, these data suggest that chronic treatment of T-cells with cAMP-elevating agents compromises beta2-adrenoreceptor-mediated cAMP accumulation by increasing the expression of HSPDE3B and HSPDE4D gene products.

Evaluation of acute physiology and chronic health evaluation III predictions of hospital mortality in an independent database

OBJECTIVE

To assess the accuracy and validity of Acute Physiology and Chronic Health Evaluation (APACHE) III hospital mortality predictions in an independent sample of U.S. intensive care unit (ICU) admissions.

DESIGN

Nonrandomized, observational, cohort study.

SETTING

Two hundred eighty-five ICUs in 161 U.S. hospitals, including 65 members of the Council of Teaching Hospitals and 64 nonteaching hospitals.

PATIENTS

A consecutive sample of 37,668 ICU admissions during 1993 to 1996; including 25,448 admissions at hospitals with >400 beds and 1,074 admissions at hospitals with <200 beds.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

We used demographic, clinical, and physiologic information recorded during ICU day 1 and the APACHE III equation to predict the probability of hospital mortality for each patient. We compared observed and predicted mortality for all admissions and across patient subgroups and assessed predictive accuracy using tests of discrimination and calibration. Aggregate hospital death rate was 12.35% and predicted hospital death rate was 12.27% (p =.541). The model discriminated between survivors and nonsurvivors well (area under receiver operating curve = 0.89). A calibration curve showed that the observed number of hospital deaths was close to the number of deaths predicted by the model, but when tested across deciles of risk, goodness-of-fit (Hosmer-Lemeshow statistic, chi-square = 48.71, 8 degrees of freedom, p< .0001) was not perfect. Observed and predicted hospital mortality rates were not significantly (p < .01) different for 55 (84.6%) of APACHE III's 65 specific ICU admission diagnoses and for 11 (84.6%) of the 13 residual organ system-related categories. The most frequent diagnoses with significant (p < .01) differences between observed and predicted hospital mortality rates included acute myocardial infarction, drug overdose, nonoperative head trauma, and nonoperative multiple trauma.

CONCLUSIONS

APACHE III accurately predicted aggregate hospital mortality in an independent sample of U.S. ICU admissions. Further improvements in calibration can be achieved by more precise disease labeling, improved acquisition and weighting of neurologic abnormalities, adjustments that reflect changes in treatment outcomes over time, and a larger national database.

Delayed external compression reduction of an omphalocele (DECRO): an alternative method of treatment for moderate and large omphaloceles

BACKGROUND/PURPOSE

Standard treatment of large hepatoomphaloceles has been SILASTIC (Dow Corning, Midland, MI) silo placement followed by closure. This requires two operations, and complications from the silo may occur. The authors have looked for a safe and simpler alternate method of closure. Delayed external compression reduction of an omphalocele (DECRO), appears to have a low complication rate and a rapid time to closure.

METHODS

The authors reviewed retrospectively the records of six patients with hepato-omphaloceles treated with DECRO from August 1993 to July 1997. All defects were evaluated by the attending surgeon and could not be closed primarily. All data are expressed as mean +/- SEM.

RESULTS

The average gestational age was 36.5 +/- 0.67 weeks with mean weight of 2,780 +/- 256 g. Two patients had congenital cardiac disease. The mean size of the defects was 6.2 x 5.7 cm. All defects had the liver out of the abdomen. No patients required silo placement. The mean time to reduction and final closure was 5.6 +/- 0.49 days. The average postoperative time on the ventilator was 7.1 +/- 3.5 days. Mean time to full feeds was 18.8 +/- 3.4 days. One patient had superficial necrosis of the skin flap. Mean time to discharge was 30.5 +/- 5.5 days. All patients had DECRO completed without complications.

CONCLUSIONS

This procedure decreases the number of operations needed from two to one. No complications were seen from the procedure and the time of mechanical ventilation required was low. The abdominal compartment syndrome developed in none of the patients. DECRO is a safe and very effective alternative to SILASTIC silo placement in moderate and large omphaloceles that cannot be closed primarily.

The role of the general practitioner in the community care of people with HIV infection and AIDS: a comparative study of high- and low-prevalence areas in England

BACKGROUND

Policy for the care of people suffering from HIV and AIDS has changed over the past decade. Schemes for shared primary and secondary care have been met with varying success, and patients may be reluctant to become involved. No systematic evaluation comparing the views of primary care providers and users in areas of varying HIV prevalence has been published.

AIM

To examine the role of general practice in areas of England with low and high human immunodeficiency virus (HIV) prevalence and to compare barriers to general practice care in each area.

METHOD

We used focus groups, semistructured questionnaires and interviews in north London (high HIV prevalence) and Nottingham (low HIV prevalence).

RESULTS

Four focus groups took place in London. A total of 411 general practitioners (GPs) in London and 405 in Nottingham replied to postal questionnaires. Overall, 121 primary care staff in 40 London practices and 26 staff in five Nottingham practices were interviewed. In all, 54 people infected with HIV were interviewed in London and 20 in Nottingham. Providers and users regarded the 24-hour availability and the familiar environment of general practice as its key assets. Lack of expertise and time were its disadvantages. Providers were concerned about inadequate communication with specialist services. Although providers were concerned about confidentiality, whether they had liberal and sympathetic attitudes was more important in deciding whether people with HIV used the service. In the low-prevalence area, general practice involvement was the result of individual initiatives, and practices were not integrated into specialist care. In the high-prevalence area, HIV care was more usual in general practice, but there was also little integration with HIV services.

CONCLUSIONS

In high-prevalence districts, a strategy to make HIV care routine for all GPs may be appropriate. In low-prevalence areas, a network of selected, strategically located, relatively high-involvement practices may be more effective in meeting the primary care needs of people with HIV infection and acquired immunodeficiency syndrome (AIDS).

Outcome measurement in adult stuttering therapy: a self-rating profile

The speech and language therapy profession is committed to the use of outcome measurement to maximise both efficiency and efficacy. However, measuring change in adult stuttering therapy is particularly problematic. It is proposed that outcomes of therapy should include stuttering behaviours, reactions to stuttering and handicap resulting from stuttering. Current methods of measuring change are reviewed. The Wright & Ayre Stuttering Self-Rating Profile (WASSP) is described which includes clients' perceptions of stuttering behaviours, avoidance, feelings and disadvantage. Issues of reliability and validity are considered.

5-Lipoxygenase and 5-lipoxygenase activating protein (FLAP) immunoreactivity in lungs from patients with primary pulmonary hypertension

Inflammatory infiltrates and endothelial cell proliferation have been appreciated in plexiform and concentric lesions, which characterize the vascular remodeling in primary pulmonary hypertension (PPH). Leukotriene production by perivascular and alveolar macrophages relies on activation of 5-lipoxygenase (5-LO), with translocation of the enzyme to the nuclear membrane, and association with the 5-LO activating protein (FLAP). Using immunohistochemical staining, we localized and semi-quantitatively estimated the abundance of 5-LO and FLAP in lungs obtained from patients with PPH, patients with interstitial lung disease (ILD), and normal control subjects. Expression of 5-LO and FLAP was prominent in alveolar macrophages in both the normal and PPH lungs; however, alveolar macrophages were more frequently clustered in the vicinity of remodeled blood vessel in PPH. Medium- and small-size pulmonary arteries in PPH showed more abundant FLAP expression than in control and ILD lungs. 5-LO expression in small arteries in PPH was more intense than in control and ILD patients. Endothelial cells in plexiform and concentric lesions in PPH expressed both 5-LO and FLAP. In situ hybridization confirmed the presence of 5-LO transcripts in macrophages and endothelial cells of the remodeled vessels in PPH. We propose that the overexpression of 5-LO and FLAP represents evidence for the participation of inflammation in the process of PPH vasculopathy or, alternatively, that the overabundance of the enzymes involved in generation of inflammatory mediators may themselves be related to vascular cell proliferation and cell growth.

Characterization of pigs transgenic for human decay-accelerating factor

BACKGROUND

To prevent the central role played by complement activation in the hyperacute rejection of pig organs transplanted into primates, pigs transgenic for human decay-accelerating factor (HDAF) have recently been produced. The data presented here extend previous immunohistochemical findings by documenting the immunological characterization and the levels of expression of HDAF in these transgenic pigs.

METHODS

Animals from 30 independently derived lines were included in this study. HDAF expression was characterized by immunoprecipitation and epitope mapping. Quantitative analysis was performed by radiometric assays followed by Scatchard analysis and by double-determinant radioimmunoassay. Deposition of iC3b on porcine aortic endothelial cells was determined by radioimmunoassay. DNA slot-blot analysis and densitometric scanning were used to evaluate HDAF transgene copy number.

RESULTS

The integrity of HDAF expressed by these transgenic pigs could be demonstrated. HDAF was present in 72% of the organs analyzed, although considerable variation in expression occurred, both between animals and within the same pig. High levels of HDAF on porcine aortic endothelial cells resulted in iC3b deposition at levels as low as that detected on human endothelial cells. Twenty-six organs expressed levels of HDAF greater than those observed in the equivalent human tissue. HDAF expression did not correlate with the number of copies of the transgene incorporated into the porcine genome.

CONCLUSIONS

Transgenic pigs, which express levels of functional HDAF even greater than those observed in humans, have successfully been produced. Pigs transgenic for human complement inhibiting molecules could represent a source of organs for future clinical xenotransplantation.

Expression of glutamyl-tRNA reductase in Escherichia coli

The biosynthesis of the hemes, chlorophylls, corrins and other tetrapyrroles begins with the synthesis of 5-aminolevulinic acid (ALA). The pathway is highly conserved except for the synthesis of ALA which is derived from glycine and succinyl CoA (C4) in most eukaryotes and from glutamate (C5) in most bacteria and in green plants. In C5, glutamyl-tRNA synthetase (GTS) converts glutamate to glutamyl-tRNA (glu-tRNA), which is reduced by glutamyl-tRNA reductase (GTR) to glutamyl-1-semialdehyde (GSA), which is converted by aminotransferase (GSA-AT) to ALA. Since GTS is also involved in protein synthesis and GSA can be converted to ALA non-enzymatically, it is highly probable that control of ALA synthesis and thus of the whole pathway resides in the GTR step. In Escherichia coli, GTR is the gene product of hemA. BL21(DE3), a protease-deficient strain which contains the T7 RNA polymerase gene in front of a lac promoter, was transformed with a pET14b-based vector, pWC01, harboring hemA in front of a T7 promoter and ORF1 which is transcribed in the opposite direction. The transformed strain, WC1201, secreted ALA and porphyrins into the medium. Induction of expression of hemA by WC1201 was optimized for concentration of inducer (IPTG, 5 mM), temperature (37 degrees C), presence of betaine and sorbitol (no change) and time of induction (2h). GTR was observable as a 46 kDa band by Brilliant blue G staining of SDS-PAGE gels. Sonicates of the induction mixture exhibited strong ALA synthesis activity which was enhanced by tRNAglu. Most of the activity was in the supernatant of the sonicate indicating that GTR is a soluble enzyme. The induced strain had more GTS activity than the uninduced strain which had more GTS activity than its parent wild-type strain. Autoradiography on native gradient PAGE showed that GTR expressed in vivo by induction of WC1201 had a molecular weight of approx. 117 kDa. Gel filtration of the induced sonicate showed a peak of enzymatic activity at about 126 kDa. When pET14b- or pUC19-based plasmids harboring hemA and ORF1, or importantly, a pUC19-based plasmid harboring only hemA and not ORF1, were expressed in an in vitro transcription-translation system, native gradient PAGE showed a product with a molecular weight of approximately 175 kDA. This expression was higher in the presence of tRNAglu. When the 117 kDa and 175 kDa proteins were excised from their native gels respectively, and run on SDS PAGE, autoradiography showed bands at 46 kDa. We conclude that GTR is present in both high molecular weight species. Since overexpression of hemA from pET14b-based plasmids is associated with increased glutamyl-tRNA synthetase activity, the 175 kDa species may represent different complexes of GTR, GTS and glutamyl-tRNA as observed in Chlamydomonas and the 117-126 kDa species may be an dimer of GTR associated with glu-tRNA or a complex of GTR, GTS and glu-tRNA. These possibilities are being investigated.

Evidence for the sensitivity of the SF-36 health status measure to inequalities in health: results from the Oxford healthy lifestyles survey

OBJECTIVES

The short form 36 (SF-36) health questionnaire may not be appropriate for population surveys assessing health gain because of the low responsiveness (sensitivity to change) of domains on the measure. An hypothesised health gain of respondents in social class V to that of those in social class I indicated only marginal improvement in self reported health. Subgroup analysis, however, showed that the SF-36 would indicate dramatic changes if the health of social class V could be improved to that of social class I.

DESIGN

Postal survey using a questionnaire booklet containing the SF-36 and a number of other items concerned with lifestyles and illness. A letter outlining the purpose of the study was included.

SETTING

The sample was drawn from family health services authority (FHSA) computerised registers for Berkshire, Buckinghamshire, Northamptonshire, and Oxfordshire.

SAMPLE

The questionnaire was sent to 13,042 randomly selected subjects between the ages of 17-65. Altogether 9332 (72%) responded.

OUTCOME MEASURES

Scores for the eight dimensions of the SF-36.

STATISTICS

The sensitivity of the SF-36 was tested by hypothesising that the scores of those in the bottom quartile of the SF-36 scores in class V could be improved to the level of the scores from the bottom quartile of SF-36 scores in class I using the effect size statistic.

RESULTS

SF-36 scores for the population at the 25th, 50th, and 75th centiles were provided. Those who reported worse health on each dimension of the SF-36 (ie in the lowest 25% of scores) differ dramatically between social class I and V. Large effect sizes were gained on all but one dimension of the SF-36 when the health of those in the bottom quartile of the SF-36 scores in class V were hypothesised to have improved to the level of the scores from the bottom quartile of SF-36 scores in class I.

CONCLUSIONS

Analysis of SF-36 data at a population level is inappropriate; subgroup analysis is more appropriate. The data suggest that if it were possible to improve the functioning and wellbeing of those in worst health in class V to those reporting the worst health in class I the improvement would be dramatic. Furthermore, differences between the classes detected by the SF-36 are substantial and more dramatic than might previously have been imagined.