Effects of vaginal distension on urethral anatomy and function

OBJECTIVE

To determine the effect of repeated and prolonged vaginal distension on the leak-point pressure (LPP) and urethral anatomy in the female rat, as prolonged vaginal distension has been clinically correlated with signs of stress urinary incontinence (SUI).

MATERIALS AND METHODS

Sixty female rats were placed into one of five groups; four groups underwent one of four vaginal distension protocols using a modified 10 F Foley catheter, i.e. prolonged (1 h), brief (0.5 h), intermittent (cycling inflated/deflated for 0.5 h) or sham distension. All animals had a suprapubic bladder catheter implanted 2 days after and were assessed urodynamically 4 days after vaginal distension. The fifth group of rats acted as controls and did not undergo vaginal distension, but did have a suprapubic bladder catheter placed and urodynamics assessed. To measure LPP the rats were anaesthetized with urethane, placed supine and the bladder filled with saline (5 mL/h) while bladder pressure was measured via the bladder catheter. LPPs were measured three times in each animal by manually increasing the abdominal pressure until leakage at the urethral meatus, when the external abdominal pressure was rapidly released. Peak bladder pressure was taken as the LPP and a mean value calculated for each animal. Immediately after measuring LPP the urethra was removed and processed routinely for histology (5 micro m sections, stained with haematoxylin/eosin and trichrome). The means (sem) were compared using a Kruskal-Wallis one-way anova on ranks, followed by a Dunn's test, with P < 0.05 indicating a significant difference.

RESULTS

Both LPP and the external increase in abdominal pressure were significantly lower after prolonged distension, at 31.4 (1.7) and 19.8 (1.2) cmH2O, than in the sham group, at 41.1 (3.2) and 32.0 (4.7) cmH2O, respectively. There were no significant differences in LPP or in the increase in abdominal pressure between the brief, intermittent and sham groups. Qualitative histology showed that prolonged distension resulted in extensive disruption and marked thinning of urethral skeletal muscle fibres. Brief and intermittent distension showed mild and focal disruptions, respectively.

CONCLUSIONS

As observed clinically, prolonged vaginal distension results in a lower LPP, greater anatomical injury and increased severity of SUI. These results suggest that ischaemia is important in the development of SUI after prolonged vaginal distension.

Culturability, injury and morphological dynamics of thermophilic Campylobacter spp. within a laboratory-based aquatic model system

AIMS

To study the survival processes of thermophilic Campylobacter spp. within a modelled aquatic system and particularly the involvement and survival potential of viable but non-culturable forms.

METHODS AND RESULTS

The survival and morphological characteristics of populations of thermophilic Campylobacter species exposed to simulated aquatic conditions were examined using a combination of cultural and microscopic techniques. Populations underwent progressive decay when exposed to simulated aquatic conditions. The rates of population decay were observed to be significantly greater at the higher temperature (20 degrees C) with a rapid transition of the dominant sub-populations from non-stressed to dead cells occurred within 3 days. At 10 degrees C the rate of culturability loss was much reduced with substantial development (approx. 80% of total population) of viable but non-culturable (VBNC) populations by all species within 3 days, declining to represent approximately 5-25% of the total population at day 60. Significant differences (P < 0.001) were identified between decay rates as a consequence of different species, sub-populations and temperature but not between sub-populations of different species. Morphological variants including spiral, elongated spirals and rods, short rods and coccoid forms were identified. The endpoints of morphological transition were temperature-independent and isolate-specific yet the rate of morphological transition was directly related to temperature and approximately equivalent between species.

CONCLUSION

The VBNC state is a transitory stage in the degeneration of Campylobacter population within the aquatic environments simulated during this study.

SIGNIFICANCE AND IMPACT OF THE STUDY

VBNC cells form the most persistent, viable, potentially pathogenic sub-population of Campylobacter populations exposed to aquatic stress conditions.

H RAS mutations in haematologically normal individuals

INTRODUCTION

Point mutations in N, K and H RAS have been found in adverse haematological malignancies. The background frequency of RAS mutations in the normal population has yet to be determined. Here we report the results of a screen for RAS mutations from normal individuals.

MATERIALS AND METHODS

DNA from peripheral blood or bone marrow from 115 haematologically normal individuals was screened for point mutations in N, K and H RAS, at amino acid positions 12, 13 and 61. The screening was done using polymerase chain reaction and oligonucleotide hybridisation and candidate mutations were subsequently confirmed by cloning and sequencing.

RESULTS AND CONCLUSION

Point mutations were identified in DNA from two of the 115 individuals. Both mutations resulted in an amino acid substitution at position 12 in H RAS. Both individuals with detectable H RAS mutations remain haematologically normal.

[Computer-assisted development of epitheses after optical recording of facial defects]

A major drawback of conventional impression techniques used for customizing facial prostheses is the fact that pressure applied deforms soft tissue, thus reducing accuracy and causing patient discomfort. A possible solution is the use of optical 3-D coordinate measuring techniques, such as the fringe projection technique, which enables precise and contact-free recording of facial surfaces. The application of this method is demonstrated on a patient who lost his left eye and part of the jaw bone during surgery for cancer. 3-D CAD software that supports the construction of a facial prosthesis from the data obtained has been developed. For this purpose, spline functions are used to define border curves, and the intact half of the face is used as a model for the prosthetic surface. The resulting digital data are used to construct first a model made of synthetic resin, and then a final wax model with the aid of rapid prototyping techniques.

In vivo and in vitro modulation of HLA-DM and HLA-DO is induced by B lymphocyte activation

Ag presentation via HLA class II molecules in B lymphocytes depends on the coordinated action of HLA-DM, the catalyst of class II-peptide loading, and HLA-DO, a pH-dependent modulator of DM, the expression of which is almost completely restricted to B lymphocytes. The relative expression levels of both class II modulators are critical for the composition of the HLA class II peptide repertoire. The data in this work demonstrate that DO and DM expression are both dependent on the cellular activation status in primary human B lymphocytes. In vivo low-density activated primary human B lymphocytes show a prominent reduction in DO and DM expression when compared with high-density resting primary B lymphocytes. In vitro, reduction of DO and DM expression can be induced by B lymphocyte activation via the B cell receptor or by use of the phorbol ester, PMA. Specific inhibition of protein kinase C resulted in a significant reduction of HLA-DO and is potentially due to protein degradation in lysosomal compartments as the phenomenon is reversed by chloroquine. Thus, the expression of the dedicated HLA class II chaperone DM and its pH-dependent modulator DO is regulated and tightly controlled by the activation status of the B lymphocyte.

The psychosocial needs of cancer patients: findings from an observational study

The objectives of this study were to identify the prevalence of psychosocial need, and the contributory factors to need, among cancer patients, using a descriptive cross-sectional questionnaire survey of adult cancer patients. The participants were 1,000 patients from four hospitals in the north west of England with the following characteristics: tumour type (breast, colorectal, lymphoma, lung), being 1 month from a 'critical moment' in the cancer journey (i.e. (i) diagnosis, (ii) end of first treatment, (iii) recurrence, (iv) move from active treatment to palliative care), and aged over 18 years. The main outcome measure was a psychosocial needs inventory comprising seven needs categories (48 need items). A sample of 402 was achieved (40% response rate). Psychosocial needs relating to the need categories 'health professionals', 'information' and 'support networks' are commonly expressed and strongly felt by cancer patients. Needs relating to 'identity', 'emotional and spiritual' issues and 'practical' issues are less commonly expressed but are also strongly felt. Particular needs are related to tumour type, illness 'critical moment', age, gender, health status, socioeconomic and other social factors. This information should increase awareness among cancer care professionals about a range of psychosocial needs and may help them target particular patient groups for particular support interventions.

Insertional mutagenesis of genes required for seed development in Arabidopsis thaliana

The purpose of this project was to identify large numbers of Arabidopsis genes with essential functions during seed development. More than 120,000 T-DNA insertion lines were generated following Agrobacterium-mediated transformation. Transgenic plants were screened for defective seeds and putative mutants were subjected to detailed analysis in subsequent generations. Plasmid rescue and TAIL-PCR were used to recover plant sequences flanking insertion sites in tagged mutants. More than 4200 mutants with a wide range of seed phenotypes were identified. Over 1700 of these mutants were analyzed in detail. The 350 tagged embryo-defective (emb) mutants identified to date represent a significant advance toward saturation mutagenesis of EMB genes in Arabidopsis. Plant sequences adjacent to T-DNA borders in mutants with confirmed insertion sites were used to map genome locations and establish tentative identities for 167 EMB genes with diverse biological functions. The frequency of duplicate mutant alleles recovered is consistent with a relatively small number of essential (EMB) genes with nonredundant functions during seed development. Other functions critical to seed development in Arabidopsis may be protected from deleterious mutations by extensive genome duplications.

Informal carers of cancer patients: what are their unmet psychosocial needs?

This paper considers the significant unmet psychosocial needs of the informal carers of cancer patients, drawing on data generated in a 3-year UK study (1997-2000) on the psychosocial needs of cancer patients and their main carers. While the needs of the carers of cancer patients are increasingly being recognised in healthcare policy documents, there is relatively little published literature on these needs. A "significant unmet need" is defined here as a need deemed important by the carer, but which has not been met. A descriptive cross-sectional survey of carers was conducted and the responses of 195 carers relating to 48 psychosocial need items were analysed. A subset of these carers (n = 32) were interviewed. Forty-three per cent of carers had significant unmet needs. They were more likely to be those where the relationship to the patient was not that of a partner or spouse, more likely to have other caring responsibilities, and less likely to have friends or relations to call upon for help. Carers with unmet needs were also more likely to be in poor health themselves or to be caring for a patient who had reached the palliation-only phase in their cancer journey. The majority of carers expressed the importance of needs such as having good relationships with healthcare professionals and receiving honest information, but few expressed dissatisfaction with these aspects of need. Items of significant unmet need clustered around aspects of managing daily life, emotions, and also social identity for a sizeable minority of carers. These are the same areas of significant unmet need that concern patients. However, carers have more of these concerns, reflecting their comparative neglect. The paper also considers how these widespread concerns can be addressed.

The significant unmet needs of cancer patients: probing psychosocial concerns

'Significant unmet needs' are those needs that patients identify as both important and unsatisfied. In this article we ask whether the overall needs of cancer patients are actually being met. We believe that the range of unmet need, and the kinds of patients who are more likely to claim unmet need, should be carefully identified. The needs responses of a series of 295 cancer patients in a cross-sectional survey were analysed. The majority expressed the opinion that information and good relationships with health care professionals were important, and few expressed dissatisfaction with these aspects of need. Similarly, needs items about support from family and friends were largely rated as important and satisfied. For a sizeable minority of patients, items of significant unmet need cluster around aspects of managing daily life, emotions, and social identity. The distribution of significant unmet needs is not random but is more likely to be experienced by patients who are younger, have a long-standing illness or disability, do not own/have use of a car, and/or have no religious faith. Furthermore, significant unmet needs relate to patients' ability to talk freely to a carer about the cancer, the degree to which the cancer interferes with social activities, and whether financial difficulties are experienced. Most of the significant unmet need is beyond the remit of services primarily designed for the treatment of disease. We consider whether multidisciplinary cancer teams can be expected to deal with all aspects of the cancer experience.

A study of occlusal variation in the primary dentition of Australian twins and singletons

In this study, we quantified the extent of variation in different occlusal features of Australian children of European descent with complete primary dentitions, but no permanent teeth present in the mouth. The study group consisted of 412 individuals, aged between 3 and 7 years, including 70 monozygous (MZ) twin pairs, 68 same-sexed dizygous (DZ) twin pairs, 11 opposite-sexed DZ twin pairs, and 114 singletons. Occlusal traits, including inter-dental spacing, incisal overbite and overjet, arch breadth and arch depth, were obtained directly from dental casts or indirectly from photocopies or impressions of the casts. Descriptive statistics summarised the data and indicated that distributions were similar to those published for other populations. Univariate genetic analysis, using the structural equation modelling package Mx, was carried out on the quantitative data using the normal assumptions of the twin model. Genetic modelling indicated that a model incorporating additive genetic (A) and unique environmental variation (E) was the most parsimonious for interdental spacing, overbite, overjet and arch dimensions. Estimates of heritability for interdental spacing ranged from 0.62 to 0.81. Estimates for overbite and overjet were 0.53 and 0.28, respectively, and estimates for arch dimensions ranged from 0.69 to 0.89. These results indicated a moderate to relatively high genetic contribution to observed variation.

Radio-prevention of micrometastases

In developed countries, the cancer incidence is about 150,000 cases per year and half of people with cancer may die from the extension of the primary tumour in secondary deposits. This disaster costs more than 2 billion euro per year. People with cancer are often treated with surgery and/or radiotherapy of localized primary tumour and chemo-prevention of occult disseminated micrometastases. Since chemotherapy essentially targets cycling tumour cells, quiescent micrometastases which may contain only one cell may escape. We previously reported that human melanoma clones with high metastatic potential and low gangliosides content appeared very radiosensitive to low-dose ionizing radiation both in culture and in immunosuppressed animals. This exquisite radiosensitivity was observed with the highly metastatic single cells which were resting at the time of irradiation. These data are consistent with the dose-response relationship for the radiotherapy of secondary deposits which appears linear with no threshold. Highly metastatic cells at an early stage of growth also appear very sensitive to chemicals and activated immune cells. We propose the medical hypothesis according to which the spread of resting micrometastases should be prevented by a single fraction of total-body irradiation delivered at a dose sufficiently low (below 0.2 Gy) to avoid normal tissue radiotoxicity. Radio-prevention may complement standard treatments for patients with metastases and may be delivered even for patients in whom no distant metastases were detected on tumour diagnosis (M0 stage).

The prevalence of mental illness in prison

Over the last decade state prisons have experienced unprecedented growth and many demographic changes. At the same time, courts are requiring states to provide mental health screening and treatment to prisoners. Findings from recent studies indicate that the prevalence of mental illness is higher in prisons than in the community, and comorbidity is common. Our ability to generalize from these studies is limited, however, because of major shifts in the demographic mix in prisons during the past decade. New studies on the prevalence of mental illness in prisons, which consider these recent changes would help planners allocate funds and staff to more effectively meet the needs of these individuals.

Mutations in the sterol-sensing domain of Patched suggest a role for vesicular trafficking in Smoothened regulation

The tumor suppressor gene patched (ptc) encodes an approximately 140 kDa polytopic transmembrane protein [1-3] [corrected] that binds members of the Hedgehog (Hh) family of signaling proteins [4-6] [corrected] and regulates the activity of Smoothened (Smo), a G protein-coupled receptor-like protein essential for Hh signal transduction [7-9] [corrected]. Ptc contains a sterol-sensing domain (SSD) [10, 11] [corrected], a motif found in proteins implicated in the intracellular trafficking of cholesterol [12] [corrected], and/or other cargoes [13-15] [corrected]. Cholesterol plays a critical role in Hedgehog (Hh) signaling by facilitating the regulated secretion and sequestration of the Hh protein [16] [corrected], to which it is covalently coupled. In addition, cholesterol synthesis inhibitors block the ability of cells to respond to Hh [18, 19] [corrected], and this finding points to an additional requirement for the lipid in regulating downstream components of the Hh signaling pathway. Although the SSD of Ptc has been linked to both the sequestration of, and the cellular response to Hh [16, 20, 21] [corrected], definitive evidence for its function has so far been lacking. Here we describe the identification and characterization of two missense mutations in the SSD of Drosophila Ptc; strikingly, while both mutations abolish Smo repression, neither affects the ability of Ptc to interact with Hh. We speculate that Ptc may control Smo activity by regulating an intracellular trafficking process dependent upon the integrity of the SSD.

Effect of intravenous platelet-activating factor on bovine pulmonary mast cells

The effect of platelet-activating factor (PAF) on bovine pulmonary mast cells (MCs) was investigated in calves aged 1-4 months. PAF was administered over a 5-min period at a rate of 50 ng/kg/min to six animals, which were killed approximately 10 min later. No macroscopical lesions were observed in the lung tissue of five control calves. On semi-thin toluidine-blue stained sections, MC cytoplasm showed profuse deep-blue granulation. In the lung tissues of PAF-treated calves, striking interstitial, alveolar and interlobular oedema and emphysema were observed. MC granules occurred at the periphery of the cytoplasm and MC nuclei were easily detectable. Moreover, the number of granules in the MC cytoplasm was remarkably low. A few granules with some metachromatic material were sometimes detected outside the cell limits. Ultrastructurally, the matrix pattern of the MC granules in lung tissues of control calves was either amorphous or granular. In lung tissues of the PAF-treated calves, the granular matrix pattern was pronounced, varying from fine- to coarse-grained, and the MCs were of reduced size, with many filiform processes and exocytotic vesicles. These findings indicate that pulmonary MC degranulation was induced by PAF in healthy calves.

Craniofacial surgery in Oman: a preliminary study of 10 cases

Craniofacial surgery requires a highly specialized surgical team, appropriate precision delicate instruments, dedicated anesthetist, and upgraded intensive care unit facilities. This type of surgery is undertaken in a large number of congenital problems such as encephalocele, craniosynostosis, hypertelorism, tumors of the craniofacial region, and for craniofacial injuries. We present our experience with craniofacial surgery in 10 patients during a 15-month period at Khoula Hospital, Muscat, Sultanate of Oman. These operations were the first of this kind to be done in this part of the world. This article highlights the need for developing craniofacial units in the Gulf region.

Glioblastoma-related gene mutations and over-expression of functional epidermal growth factor receptors in SKMG-3 glioma cells

Amplification of the epidermal growth factor receptor (EGFR) gene is found in about 40% of glioblastomas (GBMs) but is rarely detected in GBM cell lines. We confirmed that the exceptional SKMG-3 GBM cell line retained amplified EGFR genes in vitro, and found that these sequences were concentrated on extra-chromosomal DNA particles similar to double-minute chromosomes. The cells contained two other gene mutations that are associated with high-grade astrocytic tumors: extra-chromosomal amplification of the cyclin-dependent kinase-4 (CDK4) gene and a homozygous mutation within the PTEN tumor suppressor gene. Immunoblots revealed very high levels of EGFR, moderately increased expression of CDK4, and no detectable PTEN protein. The overexpressed SKMG-3 EGFRs responded to exogenous ligand and resembled normal rather than mutant receptors. A heterozygous mutation of the p53 gene (p53R282W) correlated with failure of radiation to induce the expression of cyclin-dependent kinase inhibitor p21waf1 or an early G1 cell cycle arrest. Although each of these gene mutations occurs in GBMs, SKMG-3 cells had an unusual genotype in that a p53 gene mutation co-existed with amplified EGFR genes. Nonetheless, the SKMG-3 cell line can be exploited as a model to study how oncogenic EGFR signals in GBM cells interact with over-expressed CDK4 and loss of PTEN to confer the malignant phenotype.