Evaluation of an in vitro parathyroid hormone antagonist in vivo in dogs

A potent competitive inhibitor of PTH-stimulated biological responses in vitro, [Nle8,Nle18,Tyr34] bovine PTH (bPTH)-(3-34)amide, was evaluated in vivo in dogs. These studies confirm observations in vitro, suggesting that positions 1 and 2 of the peptide are critical to its biological activity. However, unlike the results from studies in vitro, this PTH analog is a weak agonist with effects on parathyroid target tissues that produce hypercalcemia and phosphaturia and increase urinary cAMP excretion. Assessed by these three parameters of hormonal action in vivo, the estimated potency of this analog is less than 1% of that of the intact hormone. In addition, PTH-induced biological responses were not inhibited by relatively large doses of the bPTH-(3-34) analog. These results emphasize the need for a systemic, integrated approach, combining chemical with biological studies, to design effective inhibitors of hormonal action in vivo. Although the rationale for introducing particular modifications into the peptide structure is most frequently based on bioassays performed in vitro, the success of the strategy chosen must rely, ultimately, upon the demonstration of specific biological properties in vivo.     

Rat parathyroid hormone-(1-34) fragment: renal adenylate cyclase activity and receptor binding properties in vitro

The rat PTH molecule contains five sequence differences from either the bovine or the human hormone within the biologically active 1-34 region. A synthetic rat 1-34 peptide was tested for activity by in vitro activation of canine and rat renal adenylate cyclase and binding to canine renal membrane receptors. The mean potency of 21,400 Medical Research Council units/mg in the canine adenylate cyclase system and 24,900 in the rat system was 8- to 10-fold higher than human 1-34 and 2- to 4-fold greater than bovine 1-34. These values represent the highest potency we have observed to date for a PTH preparation by these assay systems. In contrast, receptor binding of the rat fragment was comparable to that of bovine and human 1-34. Half-maximal inhibition of radioligand binding occurred at 1.7- 2.0 X 10(-9) M with all synthetic hormones. Hence, the amino acid substitutions in rat 1-34 appear to affect the cyclase-activating sequence domain without increasing avidity for the receptor. Analogs combining the rat sequence with modifications known to enhance receptor binding and/or retard enzymatic degradation offer a promising approach to the preparation of still more potent parathyroid agonists.     

The phenomenon of separate intra- and extracellular resonances of difluorophosphate in 31P and 19F NMR spectra of erythrocytes

Trifluoroacetate and trifluoroacetamide, when added to a suspension of human red blood cells, give rise to separate 19F NMR signals from the intra- and extracellular species. This phenomenon has recently been exploited for measuring the membrane potential of erythrocytes. However, the separation of the peaks was incorrectly ascribed to a difference in magnetic susceptibility between the intra- and extracellular environments. Previously, we have reported well-resolved resonances in 31P NMR spectra for the intra- and extracellular populations of some phosphoryl compounds; in these cases, however, the intracellular peak is shifted to low frequency which is the opposite to the situation with the fluorinated compounds. By using difluorophosphate, which rapidly equilibrates across the membrane of human erythrocytes and which has both the phosphoryl and fluorine functional groups, we observed the separate intra- and extracellular resonances. But, the intracellular resonance was shifted to high frequency of the extracellular resonance in the 19F spectra and to low frequency in the 31P spectra. The basis for the phenomenon in both cases is thought to be the reduced hydrogen bonding inside the cells between the solvent water and the phosphoryl oxygen or fluorine atoms.     

Impact of telephone consent and potential for eye donation in the UK: the Newcastle Eye Centre study

Aims

To examine the impact of telephone consent introduced in 2007 on the eye donation rate and to report the changing trend and potential for improvement in eye donation in Newcastle upon Tyne, UK.

Methods

Relevant data were retrospectively collected from the local eye retrieval database for two separate years, namely, 2006 (before the introduction of telephone consent) and 2010. All the hospitals within Newcastle were included in the study.

Results

From 2006 to 2010, there was a 3.5-fold increase in eye donation from 32 (of 2479 deaths) to 111 donors per year (of 2213 deaths) in Newcastle (P<0.001). Consent was obtained via face-to-face interview in all 32 (100%) and 59 (53.2%) donors in 2006 and 2010, respectively. Introduction of telephone consent increased the donation rate by an additional 88.1% (from 59 to 111 donors) in 2010 (P<0.001). In addition, there was a significant increase in medical notes of the deceased being reviewed from 27.1% (671/2479 cases) in 2006 to 62.4% (1382/2213 cases) in 2010 (P<0.001). Acceptance rate of eye donation was 45.7% (32/70) in 2006 and 49.6% (111/224) in 2010 (P=0.575). Acceptance rate was positively associated with registration on organ donor register (P<0.001) and telephone consent (P<0.001), but not with age (P=0.883), gender (P=0.234), or location of death (P=0.984) of the potential donors.

Conclusion

There has been a substantial improvement in eye donation rate in Newcastle over the recent years. Introduction of telephone consent and high-quality eye donation service serve as effective measures for increasing eye donation.     

HPV type-specific prevalence using a urine assay in unvaccinated male and female 11- to 18-year olds in Scotland

Background:

We conducted a baseline prevalence survey of unvaccinated 11- to 18-year olds to inform effectiveness studies for the new human papillomavirus (HPV) immunisation programme in Scotland.

Methods:

Participants were recruited from schools and colleges and invited to provide demographic data and an anonymous urine sample for type-specific HPV testing.

Results:

Among females aged 11–14 years, the weighted prevalence was 1.1% overall; 0.9% for high-risk types and no infections were associated with types 16 and 18. Among 15- to 18-year old females, the weighted prevalence was 15.2% overall; 12.6% for high-risk types and 6.5% for types 16 and 18. Among females aged 16–18 years, infection was more frequently associated with attending college and rural schools, and showed a trend towards increasing prevalence with increasing social deprivation (P=0.045). Among males aged 11–14 years, the weighted prevalence was 1.4% overall; 1.0% for high-risk types and 0.7% for types 16 and 18. Among 15- to 18-year old males, the weighted prevalence was 3.9% overall; 2.4% for high-risk types and 0.7% for types 16 and 18.

Conclusions:

Human Papillomavirus prevalence is low among 11- to 14-year olds, which includes the age group targeted for routine vaccination. The prevalence in males and correlation with deprivation require further investigation.     

Antifungal susceptibility of Candida species using the Clinical and Laboratory Standards Institute disk diffusion and broth microdilution methods

There are conflicting reports on the agreement between the Clinical and Laboratory Standards Institute disk diffusion (M44-A) and reference broth microdilution (M27-A) methods for determination of antifungal susceptibility of yeasts. The antifungal susceptibility of 541 yeasts, the majority of which were from the oral cavity, was determined using these two methods and the accuracy of the disk diffusion method assessed for clinical testing of various Candida species. Of the strains tested, Candida albicans predominated (390 out of 541). The classification of susceptibility determined by the disk diffusion method was largely in concordance with that obtained using the broth dilution method, regardless of species within Candida genus. The overall observed agreement between these two methods was 94.7% for fluconazole and 96.7% for voriconazole was with a 'very major' discrepancy level of 1.5% and 1.7% respectively. This study demonstrates a strong agreement of the simple disk diffusion method with the more labour intensive 'gold standard' broth microdilution method. These findings would support the use of the disk diffusion method in a routine mycology service.     

Health issues among Filipino women in remote Queensland

ABSTRACT: This paper discusses health issues among Filipinas (women born in the Philippines) living in remote and rural environments in Queensland. The sample was recruited as part of the University of Queensland component of the Australian Longitudinal Study of Women's Health (ALSWH). Most of the women lived in an urban or semi-urban area (391), whereas 90 lived in rural or remote areas. Community perceptions had a much greater impact on health service utilisation in rural and remote areas than in urban areas. The transition between newcomer and old-timer is more difficult for Filipinas than for other rural women because they are visibly different from other members of the community and suffer from stigmatisation associated with perceptions of Filipinas as mail order brides. For these women, concerns about confidentiality and a reluctance to ask for support are major barriers to health service utilisation. The area of greatest concern is mental health, particularly in relation to parenting issues. Improving access may involve providing a greater awareness of what services are available and allowing women to access services in a way that does not require them to label themselves or be labelled by others.     

Revisiting community-based distribution programs: are they still needed?

Community-based distribution (CBD) programs are the optimum way of reaching people in rural areas of developing countries where conventional methods of delivery do not exist or fail. This paper reviews findings and experiences from over 30 years of efforts to implement CBD of family planning methods around the world. Although research suggests that community-based service delivery can contribute to contraceptive use, the magnitude of impact is often in doubt or its existence is questionable when compared to alternative family planning delivery services.

After the review of more than 30 years of CBD work, we found that these programs are still needed to meet the needs for contraception in rural communities and isolated city neighborhoods in developing countries. Integration with other health outreach programs, effective management, keeping training of agents brief and letting them distribute contraceptives and keeping all or part of the profits instead of paying them salaries are some of the strategies that can make CBD programs more efficient.