Entry site treatment to prevent late recurrent postoperative vitreous cavity haemorrhage after vitrectomy for proliferative diabetic retinopathy

AIMS

To assess the effectiveness of treatment to the inner sclerostomy sites at the time of vitrectomy for proliferative diabetic retinopathy (PDR) in reducing the incidence of late recurrent postoperative vitreous cavity haemorrhage (POVCH).

METHOD

Retrospective study of a consecutive series of 82 eyes undergoing vitrectomy for PDR by a single surgeon treated with either cryotherapy or argon laser directly to the inner sclerostomy site at the completion of surgery (treatment group). These were compared with a previous consecutive series of 82 eyes operated on by the same surgeon who did not have inner sclerostomy site treatment (control group). The occurrence of any POVCH was recorded within the first 6 months of surgery.

RESULTS

The composition of the two groups was similar in terms of age, indication for surgery and a variety of other preoperative factors. There were 64 patients in the control group and 65 in the treatment group. There was a significant reduction in the incidence of late recurrent POVCH in the treatment group. Late recurrent POVCH occurred in 12 (15%) eyes in the control group compared with five (6%) in the treatment group (p=0.03). The number of eyes requiring revision surgery within the first 6 months for late recurrent POVCH was four (5%) in the control group and two (2.5%) in the treatment group (p=0.31).

CONCLUSION

This study suggests that inner sclerostomy site treatment is effective in reducing the occurrence of recurrent late POVCH in patients undergoing vitrectomy for PDR. A randomised controlled study is needed to clarify this.

Novel therapeutic agents and strategies for the management of chronic kidney disease mineral and bone disorder

Abnormalities in the serum concentrations of calcium, phosphate, parathyroid hormone and vitamin D develop with declining renal function, leading in turn to renal osteodystrophy. Observational data now suggest that these disturbances in bone and mineral metabolism play an important role in the development of vascular calcification and subsequent cardiovascular disease, contributing to the high burden of cardiovascular disease within this population. A new nomenclature-"chronic kidney disease mineral and bone disorder"-has been introduced to describe this broader clinical syndrome and reflect the new emphasis that has been placed upon its management. This article describes the current therapeutic options for this condition, focusing particularly on the novel medications and strategies that have recently been introduced, and highlighting promising therapeutic possibilities for the future.

Scintigraphy can be used to compare delivery of sore throat formulations

AIMS

Sore throat (pharyngitis) is commonly treated with over-the-counter lozenges, tablets, sprays and gargles. While the efficacy of the active ingredients has been examined, less is known about the comparative efficacy of the different delivery formats.

METHODS

A pilot study was initially performed, followed by an open-label, four-way crossover study in healthy volunteers to quantitatively assess the delivery efficacy of a lozenge, tablet, spray and gargle, using technetium-99m and scintigraphy as a marker of deposition and clearance of the active ingredients.

RESULTS

Initial deposition in the mouth and throat combined was significantly greater for the solid dose forms (lozenge and tablet) than for the spray or gargle. Rates of clearance were initially similar for the tablet and lozenge with low levels of radioactivity present at up to 2 h. At 10 and 20 min, significantly more of the dose remained for the lozenge than for the tablet. The mouth appeared to act as a reservoir for continued clearance to the throat.

DISCUSSION AND CONCLUSION

Scintigraphy is an effective means of quantifying the delivery efficiency, and hence availability, of sore throat medications. The results presented here suggest that both lozenges and tablets offer considerable advantages over sprays or gargles, both in terms of proportion of the dose delivered to the mouth and throat, combined, and clearance from these regions. These delivery formats provide fast, effective and prolonged delivery of active ingredients, highlighting their potential benefits for sore throat medication.

Two Unusual Cases Of Calcific Uraemic Arteriolopathy

Calcific uraemic arteriolopathy is a small vessel vasculopathy occurring almost exclusively in patients with renal failure. Violaceous mottling of the lower limbs, buttocks or lower abdomen precedes the development of painful, necrotic, non-healing ulcers. We report two atypical manifestations of calcific uraemic arteriolopathy and highlight a condition which is seen increasingly frequently as the number of patients undertaking dialysis continues to rise.

Mosaicism in autosomal dominant polycystic kidney disease revealed by genetic testing to enable living related renal transplantation

Patients with end-stage renal disease (ESRD) secondary to autosomal dominant polycystic kidney disease (ADPKD) receive fewer living-related kidney (LRK) transplants than other groups with ESRD. This relates to the difficulties in excluding the disease in potential donors. We report a case which highlights these difficulties and, by discovery of mosaicism for a new mutation, illustrates the role of clinical and molecular genetic resources in assessing young related kidney donors for patients with ADPKD.

Increased susceptibility of human respiratory syncytial virus to neutralization by anti-fusion protein antibodies on adaptation to replication in cell culture

Subgroup A respiratory syncytial viruses present in respiratory secretions and low passage level cell culture isolates were found to be markedly less susceptible to neutralization with monoclonal antibodies (MAbs) to the F glycoprotein than the cell culture adapted A2 virus strain. Low passage virus isolates collected over a 20 year period and belonging to several sub-group A lineages were refractory to neutralization with antibodies recognizing two major neutralizing antigenic sites located sub-terminally at opposite ends of the F(1) glycoprotein sub-unit. On further passage in cell culture, virus isolates exhibited both increased infectivity titers and increased susceptibility to neutralization by antibodies to both antigenic sites. The consensus nucleotide sequence of the membrane associated proteins M and of the SH, G and F glycoprotein genes, and their intergenic regions were compared for neutralization resistant and susceptible stocks of one virus strain, R17532. No changes were observed in the known monoclonal antibody epitopes on the F glycoprotein. In line with this, the increase in susceptibility was not found to be associated with any increased binding of monoclonal antibody to isolated F glycoprotein in a BIAcore assay, thus excluding the possibility that passage in cell culture selected for viruses with mutations in the antibody binding sites. M and SH genes were conserved but a number of sites in the G and F glycoprotein genes were found to vary on adaptation to cell culture suggesting that change in susceptibility to neutralization was associated with a change in the prevalent quasispecies present in the virus population. The genetic basis of phenotypic change in susceptibility remains to be determined.

The TRENDS Project: development of a methodology to reliably monitor the obesity epidemic in childhood

AIMS

The government has set a target to halt the rise in childhood obesity in those aged under 11 by 2010, but no system is in place to ascertain if this has been achieved. We aimed to develop a simple and reproducible methodology to monitor trends in childhood obesity.

METHODS

A purposive sample of 10 primary schools and three secondary schools was selected. Children were measured with parental "opt out" consent in reception class, year 4, and year 8 (ages 5, 9, and 13 years, respectively). Measurements were compared with those obtained locally in 1996-2001. Calculations were then performed to ascertain the sample size required to confidently identify a halt in the rise in obesity using three growth measures.

RESULTS

A total of 999 children were measured with ascertainment of 95% in primary and 85% in secondary schools. The proportion of overweight and obese children aged 9 and 13 years had increased since 1996-2001, although only 9 year olds showed a significant rise. A general trend of an increase in obesity was observed with increasing age. Calculations showed that 1900-2400 children per age group are needed to detect a halt in the rise in obesity based on mean body mass index (BMI) standard deviation scores (SDS) by 2010 with 90% power, whereas 4200-10 500 children are needed for other measures.

CONCLUSION

We have developed a simple, cost effective methodology for accurately measuring the epidemic and recommend the use of mean BMI SDS for demonstrating if a halt has been achieved.

ST7-mediated suppression of tumorigenicity of prostate cancer cells is characterized by remodeling of the extracellular matrix

Multiple lines of evidence have provided compelling evidence for the existence of a tumor suppressor gene (TSG) on chromosome 7q31.1. ST7 may be the target of this genetic instability but its designation as a TSG is controversial. In this study, we show that, functionally, ST7 behaves as a tumor suppressor in human cancer. ST7 suppressed growth of PC-3 prostate cancer cells inoculated subcutaneously into severe combined immunodeficient mice, and increased the latency of tumor detection from 13 days in control tumors to 23 days. Re-expression of ST7 was also associated with suppression of colony formation under anchorage-independent conditions in MDA-MB-231 breast cancer cells and ST7 mRNA expression was downregulated in 44% of primary breast cancers. Expression profiling of PC-3 cells revealed that ST7 predominantly induces changes in genes involved in re-modeling the extracellular matrix such as SPARC, IGFBP5 and several matrix metalloproteinases. These data indicate that ST7 may mediate tumor suppression through modification of the tumor microenvironment.

Staff expressed emotion and causal attributions for client problems on a low security unit: an exploratory study

This is an exploratory study that sought to investigate a number of measures of staff-patient relationships on a continuing care, low security inpatient facility for patients with severe mental illness. Twenty staff members were assessed for expressed emotion (EE) using the Camberwell Family Interview (CFI) in regard to a client for whom they were a designated key worker. Their spontaneous attributions for the patient's problems were also assessed, along with self-report staff and patient ratings of their expressed and perceived feelings and thoughts about their staff or patient counterpart. The study found that although none of the staff were rated as fulfilling criteria for high EE, there was evidence of some variability in the quality of staff-patient relationships as assessed from the subjective self-report scales of staff and patients. Patients seemed to be sensitive to staff feelings for them: patient ratings of perceived feelings and thoughts from staff were significantly correlated with staff expressed feelings both from the CFI EE ratings and the direct self-report staff measures. Staff tended to view the behaviors of patients they felt less positively disposed toward as more controllable, and this association between less benign explanations of behavior and a more critical attitude is consistent with the attribution research for familial caregivers. The more negatively perceived patient group was found to be more likely to have behavioral disturbances in the 7 months after the relationship ratings were made. This article discusses measurement issues in the assessment of formal caregiver-patient relationships in the light of this and previous studies.

Clinical correlations of diffusion and perfusion lesion volumes in acute ischemic stroke

The aim of this study was to describe the clinico-radiological correlations of magnetic resonance (MR) perfusion and diffusion-weighted imaging (DWI) abnormalities in ischemic stroke. Eighteen patients had undergone MR imaging and clinical evaluation within 24 h of symptom onset and at or after 7 days. During the first 24 h the volume of perfusion abnormality (measured on the relative mean transit time map) was larger than the DWI lesion in 12/18 patients. In 6/18 patients the DWI lesion volume was larger. Acutely (<24 h) all lesion volumes showed a significant correlation with acute clinical severity measured by the National Institutes of Health Stroke Scale score. The correlations of the hypoperfusion volume (rho = 0.86, p = 0.0001) and the volume 'tissue at risk' (larger than the DWI and perfusion lesion volumes, rho = 0.86, p = 0. 0001) with acute clinical severity were slightly higher than for the DWI lesion volume (rho = 0.76, p = 0.0001). The difference between the volume of tissue at risk (acutely) and the infarct on follow-up T(2)-weighted imaging correlated significantly with change in clinical severity from acute to chronic time points (rho = 0.72, p = 0.001). Such clinico-radiological relationships may support the use of DWI and perfusion MR in decisions concerning the administration and evaluation of stroke therapies.

Peer education project with persons who have experienced homelessness

This paper describes an unconventional health education project implemented by nurse practitioners in a nurse-managed clinic serving persons who are homeless. The nurse practitioners perceived that there were a number of potential barriers to providing health education to the homeless patients. These barriers included the fact that this patient population is part of a marginalized subculture affected by a variety of overwhelming social problems. An additional barrier was that the nurses often differed from their homeless patients in terms of race, gender, socioeconomic status, formal education, culture, and life experience. The nurse practitioners designed the Peer Health Education Project (PHEP) to try to overcome some of these barriers. The purpose of the PHEP was to increase the health education knowledge and empowerment of persons who had experienced homelessness so that they could serve as peer health educators with others who were living on the streets. The project model was based on the philosophy of Paulo Freire (1973). The peer health educators served as both leaders and participants in each education session. The educators set the agenda and the nurses acted as facilitators. The project was successful in preparing peer educators. Other indicators of the success of the project included increased empowerment, self-esteem, dignity, hope self-confidence, and community participation of the peer educators.

Ischemic lesion volumes in acute stroke by diffusion-weighted magnetic resonance imaging correlate with clinical outcome

Diffusion-weighted magnetic resonance imaging detects ischemic injury within minutes after onset, and has been used to demonstrate drug efficacy in animal models of stroke. In 50 patients diagnosed with acute ischemic stroke (<24-hour duration) within the middle cerebral artery territory, lesion volume was measured by diffusion-weighted imaging. Thirty-four patients also had volumes measured by T2-weighted imaging chronically (median time, 7.5 weeks; mean, 15.9 weeks). Clinical severity was measured by the National Institutes of Health Stroke Scale Score and the Barthel index. Acute lesion volumes correlated with the acute stroke scale score (r = 0.56), the chronic stroke scale score (r = 0.63), and chronic lesion volumes (r = 0.84). Chronic volumes correlated with the chronic stroke scale score (r = 0.86) and the Barthel index (r = -0.60). When only cortically based lesions were considered, the correlations relating acute lesion volume measured by diffusion-weighted imaging (r = 0.61) and chronic lesion volume measured by T2-weighted imaging (r = 0.90) to the chronic stroke scale score were higher. These results provide evidence that lesion volumes determined by diffusion-weighted imaging acutely may be predictive of clinical severity and outcome, and may support a role for diffusion-weighted imaging in the assessment of acute stroke therapies in clinical trials.

The road in and out of homelessness: perceptions of recovering substance abusers

In this phenomenological study the authors explored the meaning of homelessness from the perspective of previously homeless substance abusers. The sample involved 8 adult males recruited from a substance abuse treatment program. Through the use of open-ended questioning, two major themes were identified: the road to homelessness and the road out of homelessness. The road to homelessness comprised an explanation for the participants' homelessness: painful background experiences, negative self-concept, ineffective coping skills, and a sense of hopelessness. The road out of homelessness described the recovery process and included turning points, experiences of caring relationships, and a new way of viewing the world. The findings offer a beginning understanding of the experience of homelessness and recovery, and have implications for intervention and future research for subpopulations of persons who are homeless.

Interchromosomal recombination is suppressed in mammalian somatic cells

Homologous recombination occurs intrachromosomally as well as interchromosomally, both in mitotic (somatic) cells as well as meiotically in the germline. These different processes can serve very different purposes in maintaining the integrity of the organism and in enhancing diversity in the species. As shown here, comparison of the frequencies of intra- and interchromosomal recombination in meiotic and mitotic cells of both mouse and yeast argues that interchromosomal recombination is particularly low in mitotic cells of metazoan organisms. This result in turn suggests that the recombination machinery of metazoa might be organized to avoid the deleterious effects of homozygotization in somatic cells while still deriving the benefits of species diversification and of DNA repair.

Assessing ethnicity from human mitochondrial DNA types determined by hybridization with sequence-specific oligonucleotides

A logistic regression model was developed to predict ethnic group from mitochondrial DNA (mtDNA) types determined by hybridization with sequence-specific oligonucleotide (SSO) probes of the two hypervariable segments of the mtDNA control region. The model was developed with, and tested against, a previously reported data set of 525 individuals from five ethnic groups (African-American, Southeast Asian, Caucasian, Japanese, and Mexican) involving 23 probes at nine regions within the two hypervariable segments [1]. The model correctly predicted the ethnic group of 65.3% of the overall sample; however, the success rate varied substantially among ethnic groups, with the most success obtained with Caucasians (81% correctly classified). A discriminant analysis yielded similar results. An example is given of using the model to predict the ethnic group of an SSO-type from a forensic case. Such models provide alternatives to traditional skeletal-based methods of predicting ethnicity, especially in cases where skeletal material is absent or incomplete.

On the linkage between RNA processing and RNA translatability

The immunoglobulin mu heavy chain gene of mouse hybridoma cells is expressed in two forms, microseconds and microns, differing in their use of 3' exons. As for many other mammalian genes, mutations in the mu gene which prematurely terminate translation often have the effect of reducing the amount of these mu RNAs. To test the generality of this relationship, we selected mutant hybridoma cell lines defective in IgM production and searched both for translation termination mutations which do not reduce the amount of mu RNA as well as for mutants which show the more commonly observed reduction in mu RNA. As observed previously, the amount of microseconds RNA is normal in mutants terminating in the C mu 4 exon; by contrast the amount of microns RNA is reduced in these mutants, indicating that the effect of the mutation is influenced by some feature near the 3' end of the RNA. Mutations terminating translation in other C region exons have a graded effect on RNA content, ranging from 10% the normal level for termination in the C mu 3 exon down to 1% for termination in the C mu 2 exon. By contrast, a mutant cell line terminating in the leader exon contained 25% the normal amount of mu RNA, suggesting that translation past some point might be required to fully engage the RNA degradation process.

The mitogen-regulated protein/proliferin transcript is degraded in primary mouse embryo fibroblast but not 3T3 nuclei: altered RNA processing correlates with immortalization

An understanding of what changes occur in the control of gene expression when mammalian cells "spontaneously" immortalize is important to our knowledge of how cancer develops. We describe here an alteration in regulation that occurs when primary mouse embryo fibroblasts (MEFs) are immortalized according to a 3T3 regimen. Mitogen-regulated protein/proliferin mRNA is undetectable in northern blots of RNA from (mortal) MEFs, whereas it is readily detected in immortal 3T3 cell lines derived from the MEFs. Incompletely processed nuclear transcripts of the mitogen-regulated protein/proliferin gene can be detected in MEF RNA preparations by northern blotting and reverse transcriptase polymerase chain reaction analyses, although at roughly half the abundance observed in 3T3 cells. We hypothesize that some attribute of the primary unprocessed transcript determines its assignment to this unique degradative pathway. These results reveal that during passage of MEFs according to a 3T3 regimen the ability of the primary cells to suppress the expression of certain genes by degrading the nuclear transcript is lost concomitantly with immortalization.

Evolutionary models of quantitative disease risk factors

Numerous mutations are now known that have significant effects on various phenotypes; many of these mutations are of interest because they influence quantitative risk factors for major diseases. Such diversity raises the question of how much genetic heterogeneity we should expect to find in the effects of alleles, that is, the size of the effects, the number of severe alleles, and their frequency in the population. Can evolutionary models suggest a general pattern? In this article we examine what is currently known about several basic aspects of the problem. These include the distribution of quantitative effects of new mutations on a phenotype, the distribution of allelic effects that would be found in a natural population, and the relationship between these effects and Darwinian fitness. We discuss these issues in light of various models that have been proposed and the existing relevant data. Then we consider how these points relate to the distribution of genetic effects on an important human trait, the cholesterol ratio, an important risk factor for coronary heart disease. The complexities of quantitative traits and inadequacies in the available data prevent definitive models that can directly connect the mutational effects, allelic effects, and fitness distributions from being developed, and we consider how sample limitations and the nonequilibrium of human populations caused by our demographic history make rigorous solutions difficult. However, based on what is currently known, we argue that for human quantitative chronic disease risk factors the nearly neutral models of allelic evolution at single loci probably apply reasonably well. In general, and although much is still speculative, the data available for such risk factors are consistent with these expectations and may enable us to predict many aspects of etiologic heterogeneity for human disease.