Bone morphogenetic protein 2 inhibits platelet-derived growth factor-induced c-fos gene transcription and DNA synthesis in mesangial cells. Involvement of mitogen-activated protein kinase

Bone morphogenetic proteins (BMPs) play an important role in nephrogenesis. The biologic effect and mechanism of action of these proteins in the adult kidney has not yet been studied. We investigated the effect of BMP2, a member of these growth and differentiation factors, on mitogenic signal transduction pathways induced by platelet-derived growth factor (PDGF) in glomerular mesangial cells. PDGF is a growth and survival factor for these cells in vitro and in vivo. Incubation of mesangial cells with increasing concentrations of BMP2 inhibited PDGF-induced DNA synthesis in a dose-dependent manner with maximum inhibition at 250 ng/ml. Immune complex tyrosine kinase assay of PDGF receptor beta immunoprecipitates from lysates of mesangial cells treated with PDGF showed no inhibitory effect of BMP2 on PDGF receptor tyrosine phosphorylation. This indicates that the inhibition of DNA synthesis is likely due to postreceptor events. However, BMP2 significantly inhibited PDGF-stimulated mitogen-activated protein kinase (MAPK) activity that phosphorylates the Elk-1 transcription factor, a component of the ternary complex factor. Using a fusion protein-based reporter assay, we also show that BMP2 blocks PDGF-induced Elk-1-mediated transcription. Furthermore, we demonstrate that BMP2 inhibits PDGF-induced transcription of c-fos gene, a natural target of Elk-1 that normally forms a ternary complex that activates the serum response element of the c-fos gene. These data provide the first evidence that in mesangial cells, BMP2 signaling cross-talks with MAPK-based transcriptional events to inhibit PDGF-induced DNA synthesis. One target for this inhibition is the early response gene c-fos.

Social conditions and paediatric day case tonsillectomy

OBJECTIVE

To develop a simple method for assessing the proportion of children referred to hospital for tonsillectomy in different areas likely to be suitable for day case treatment based on their medical and social characteristics.

METHODS

Four patient suitability criteria were selected based on previous experience of successful day case surgery and a literature review of the prevalence of contraindications and postoperative complications, as follows: medical contraindications (at least American Society of Anesthetists grade ASA2 to be eligible); home circumstances (no telephone, no car and single parent households were ineligible); distance from the hospital (more than 10 miles resulted in ineligibility); and likelihood of postoperative complications. Data relating to the social criteria were collected prospectively from 500 children under 12 years of age reviewed in the outpatient department and under the care of one of the authors. In addition, the electoral ward UPA8 (Jarman 8) deprivation score relevant to each child was recorded and the sample was divided into quintiles according to mean UPA8 scores. In each quintile, the percentage of children with the appropriate social criteria for day case tonsillectomy was calculated. The relationship between deprivation score and social criteria for day case tonsillectomy was determined using logistic regression.

RESULTS

The proportion of children deemed socially suitable for day surgery fell continuously from 95% in the least deprived quintile to 55% in the most deprived group (proportion passing the social criteria for suitability = -1.5035 + 0.0298UPA8). Using these findings and those from the literature review on the nature and prevalence of contraindications and postoperative complications, a simple formula for realistic day case tonsillectomy targets was specified as A x B x C x D x 100%, where A is the proportion of children with no additional medical problems, B is the proportion passing the social suitability criteria, C is the proportion living within 10 miles and D is the proportion with no postoperative complications. Values for A and D would be derived from local audits.

CONCLUSIONS

The formula can be used by purchasers and hospital managers to set differential day case targets for hospitals related to the characteristics of their patients referred for tonsillectomy. In principle, a similar approach could be applicable to other procedures and other age groups.

Sulfonylureas and ischaemic preconditioning; a double-blind, placebo-controlled evaluation of glimepiride and glibenclamide

AIMS

Glimepiride is a new sulfonylurea for diabetes treatment which is supposed to impact less on extra-pancreatic ATP-dependent K+ channels than the conventional drug glibenclamide. This study was performed to evaluate whether this results in a better maintenance of ATP-dependent K+ channel mediated ischaemic myocardial preconditioning.

METHODS AND RESULTS

In a double-blind placebo-controlled study the period of total coronary occlusion during balloon angioplasty of high grade coronary artery stenoses was used as a model to compare the effects of both drugs. Quantification of myocardial ischaemia was achieved by recording the intracoronary ECG and the time to the occurrence of angina during vessel occlusion. All patients underwent three dilatations. The first dilatation (dilatation 1) served to determine the severity of ischaemia during vessel occlusion. During dilatation 2, baseline values were recorded. Thereafter, glimepiride (15 patients: 1.162 mg), glibenclamide (15 patients: 2.54 mg) or placebo (15 patients) were intravenously administered over 12 min. Dilatation 3 started 10 min after the beginning of the drug administration. Mean ST segment shifts in the placebo group decreased by 35% (dilatation 2: 0.23; dilatation 3:0.15 mV; CI -0.55 to 0.00 mV; P=0.049). A similar reduction also occurred in the glimepiride group, in which repetitive balloon occlusion led to a 34% reduction (dilatation 2: 0.35; dilatation 3: 0.23 mV; CI -0.21 to -0.02 mV; P=0.01). There was little influence however, on mean ST segment shifts in the glibenclamide group (dilatation 2 and dilatation 3: 0.24 mV; CI -0.10 to 0.25 mV; P=0.34). Accordingly, time to angina during balloon occlusion slightly increased (by 30%) in the placebo group (dilatation 2: 37 s; dilatation 3: 48 s; CI 0.0 to 15.0 s; P=0.16); increased by 13% in the glimepiride group (dilatation 2: 40 s; dilatation 3: 45 s; CI 0.0 to 14.0 s; P=0023); and remained unchanged in the glibenclamide group (dilatation 2 and dilatation 3: 30 s; CI -7.5 to 7.5 s; P=0.67).

CONCLUSION

These results show that glimepiride maintains myocardial preconditioning, while glibenclamide might be able to prevent it.

Quantifying the risks of TB infection to cattle posed by badger excreta

Despite strong circumstantial evidence to suggest that the main route of TB transmission from badgers to cattle is via contaminated badger excreta, it is unclear whether the associated risks are high enough to account for the prevalence of the disease in south-west England. To decide whether this was a viable route of transmission, cattle contact with badger excreta was investigated using a deterministic approach to quantify the risks to cattle posed by badger excreta. Levels of investigative and grazing contacts between cattle and badger urine and faeces could each account for the disease prevalence in south-west England. An infection probability of 3.7 x 10(-4) per bite from pasture contaminated with badger urine infected with Mycobacterium bovis could account for the prevalence of TB in cattle in south-west England. Infection probabilities of 6.9 x 10(-7) per investigation and 1.1 x 10(-7) per bite from badger latrines could each account for the prevalence of TB in cattle in the south-west. When considering only the high risk areas of south-west England these bounds fell by a factor of eight. However, badger excreta may still constitute a high level of risk to cattle. The levels of cattle contact with badger excreta are far higher than previously thought, suggesting that it is the probability of infection per given contact with infected badger excreta which has the greater influence on the probability of transmission and not the level of contact. The infection probability per cattle contact with infected badger excreta is in all likelihood extremely low.

Activation of extracellular signal-regulated kinases 1 and 2 by insulin-like growth factor I in human osteosarcoma MG-63 cells

The activation of extracellular signal-regulated kinases 1 and 2 by insulin-like growth factor I in human osteosarcoma MG-63 cells was examined by Mono Q ion exchange chromatography of cell extracts and measurement of myelin basic protein kinase activity, and by immunoblotting of cell extracts with a phospho-specific extracellular signal-regulated kinase antibody. Extracellular signal-regulated kinase 1 appeared to be activated in resting cells and addition of insulin-like growth factor I resulted in the activation primarily of extracellular signal-regulated kinase 2. Extracellular signal-regulated kinase 2 was found in the nucleus after addition of insulin-like growth factor I.

Factors affecting broadband ultrasound attenuation results of the calcaneus using a gel-coupled quantitative ultrasound scanning system

This study aimed to assess the factors that may influence the distribution and description of broadband ultrasound attenuation (BUA) and to identify specific criteria for diagnostic consideration when collecting BUA reference data. Two hundred Caucasian women (aged 20-79 years) without a history of atraumatic fractures or medicines known to affect bone metabolism were selected for this study. Medical and menstrual history, medication usage, family history of osteoporosis (FHO), physical activity, activities of daily living (ADL), dietary calcium intake, as well as smoking and alcohol consumption were obtained. Broadband ultrasound attenuation (BUA, dB/MHz) was determined in the right foot using a new gel-coupled ultrasound system. BUA was significantly associated with age (p<0.001), body weight (p<0.001), level of physical activity (p = 0.024) and dietary calcium intake (p = 0.023). Smoking, alcohol and coffee consumption and ADL were not associated with BUA (p>0.05). There were no differences in BUA (p>0.05) between those women who reported taking medications or had diseases (known to not affect bone metabolism), were using contraceptives, taking vitamin/mineral supplements and/or had traumatic fractures and their counterparts who did not report these characteristics. Premenopausal women with a FHO had significantly lower BUA values compared with those without a FHO (p = 0.013). When those participants with a FHO were removed from the sample, the peak BUA value was 1.1-4.4% higher and the variability (SD) was reduced by about 3.3-9.3% depending on which age range was used to define the peak BUA value. Consequently, an additional 4.5% of the population were classified as having a T-score <-2. Our results suggest that the impact on BUA of risk factors such as a FHO, body weight, physical activity and dietary calcium intake is similar to that on bone mineral density obtained by dual-energy X-ray absorptiometry (DXA), and thus provides further information on the comparability of quantitative ultrasound and DXA for assessment of risk of fracture. The criteria for calculating the T-score need further study to determine whether young adults with FHO should be included and what cutoff age range should be used in collecting peak values of quantitative ultrasound parameters.

Potential fitness benefits of group living in the red fox, Vulpes vulpes

For species such as the red fox, spatio-temporal variation in resource availability may promote group living even when the benefits of group formation are not of significant magnitude to promote territorial expansion and delayed dispersal. In this paper we use data from an urban fox population to compare the relative benefits of dispersal and natal philopatry as routes to attaining dominant status and investigate the potential benefits of territory inheritance, alloparental care and reproduction to subdominant individuals. More offspring, of either sex, remained on their natal territory than dispersed. The annual rate of retention of dominant status and the annual mortality rate of subdominant animals was high, such that the majority of subdominant animals never became dominant. The mortality rate of dispersing individuals was also high. The relative success rate of dispersal and philopatry as routes to dominance were broadly similar, although several philopatric offspring became dominant only after their natal territory was divided: in the absence of such changes, dispersal was more likely to lead to dominant status. Thus, it is likely that some other benefit was accrued by philopatric individuals. The majority of subdominants provisioned cubs. This did not increase the number of cubs reared but reduced the level of provisioning by dominants: whether this promoted dominants' longevity is unknown. There were high levels of reproduction by subordinate females and the levels of alloparental care by subdominants of both sexes suggest that there are comparable levels of direct reproduction by subdominant males. (c) 1998 The Association for the Study of Animal Behaviour.

Renal tract abnormalities detected in Australian preschool children

OBJECTIVE

To quantify the incidence of abnormalities in urinalysis and blood pressure from preschool children and their predictive value in detecting renal disease within an Australian community.

METHODOLOGY

Urine samples, blood pressure and height measurements and parental reports of significant medical problems were collected from a total of 9355 South Australian preschool children. Seven hundred and forty-three children with abnormal results were investigated in a nephrology outpatient clinic. A control group of 357 children with no detectable abnormality were also recalled, examined and, where appropriate, investigated.

RESULTS

Nine thousand, three hundred and fifty-five children were tested. Of these, 0.81% were shown to have a clinically significant renal tract abnormality. The findings included children with urinary tract infections, vesico-ureteric reflux, glomerular disease, renal calculi, essential hypertension and a renal neoplasm. While dipstick-based methods were the most specific indicators of renal tract abnormalities, measurement of blood pressure and urinary beta2-microglobulin were also important in detecting abnormalities. Screening for glycosuria did not result in the detection of significant undiagnosed abnormalities. In the control group with no abnormality detected at testing, there was one case each of aortic coarctation, polycystic kidney disease and vesico-ureteric reflux diagnosed.

CONCLUSION

Undiagnosed renal tract abnormalities are present in many Australian preschool children. Most are detectable by a thorough history, examination and urinalysis.

An autoantibody is modified for use as a delivery system to target the cell nucleus: therapeutic implications

A murine monoclonal anti-dsDNA antibody was found to penetrate living cells and localize in the nucleus without pathologic effects. A single mutation in VH markedly enhanced cellular penetration. The mutant antibody was produced as recombinant Fab and single chain antibody fragments to investigate its use as a delivery system to target the cell nucleus. Complexes were made containing Fab fragments and alkaline phosphatase conjugated goat antibodies to mouse |gk chains. Fab fragments transported 305 kDa goat antibody-enzyme complexes into the nucleus in COS-7 and CHO cells. A single chain antibody cDNA was constructed by splice overlap extension PCR and expressed in COS-7 cells. Binding of the single chain antibody to dsDNA was shown by ELISA, and cellular penetration and nuclear localization were demonstrated in COS-7 and CHO cells. The single chain antibody cDNA was ligated into the expression vector, pEGFP, to produce a fusion protein with green fluorescent protein. The fusion protein penetrated COS-7 cells and localized in the cell nucleus. The single chain antibody produced during sustained expression in CHO cells re-entered antibody-producing cells and localized in the nucleus without affecting cell viability. Our results demonstrate the potential use of a modified autoantibody as a delivery system to target the cell nucleus.

Perceptions of alcohol-related attendances in accident and emergency departments in England: a national survey

The results from a survey, conducted in February and March 1997, of all Accident and Emergency (A&E) departments in England are presented. The survey examined staff perceptions of the preventive role of A&E departments in screening and intervention in alcohol-related attendances. Perceptions of the prevalence of alcohol-related attendances were also included. Attitudes towards developing a preventive response were positive. Few departments currently screen or offer intervention and considerable barriers to the implementation of a preventive response were reported.

Cartilage protective agent (CPA) Ro 32-3555, a new matrix metalloproteinase inhibitor for the treatment of rheumatoid arthritis

CPA was well tolerated at all dose levels (10-150 mg) following single oral dose administration to healthy male volunteers. There was no relationship between the intensity, duration and number of adverse events reported and the dose of CPA. There was a dose-related increase in exposure as measured by AUC0-infinity and Cmax. Administration of 10 mg CPA following food resulted in a delayed tmax, and a significant decrease in Cmax but not AUC0-infinity.

Perspectives on the nursing management of osteoarthritis

Osteoarthritis is a daily presence in the lives of almost 16 million older people. Without expert nursing care, functional health status and the ability to manage independently may be dramatically altered. Nursing parameters include pain control, medication assessment, use of exercise, diet, joint protection, and attention to the psychosocial factors that affect both pain and disability. Patient education with regular, periodic follow-up is a vital part of successful long-term management.