bluuebunny/crossref_metadata_2025 huggingface dataset:
Behaviour of human osteoblastic cells cultured on plasma‐sprayed titanium implants in the presence of nicotine
Authors: Pereira Maria Lurdes , Carvalho João Costa , Peres Fernando , Gutierres Manuel , Fernandes Maria Helena
Published: April 2008

Objectives: The aim of this work was to analyse the behaviour of human bone marrow osteoblastic cells cultured on the surface of routinely used plasma‐sprayed titanium implants in the presence of plasmatic and salivary nicotine levels reported in smokers.

Material and methods: Human bone marrow cells (first subculture) were seeded on titanium implants and cultured for 35 days in α‐minimal essential medium supplemented with 10% foetal bovine serum, 50 μg/ml ascorbic acid, 10 mM β‐glycerophosphate and 10 nM dexamethasone. Seeded implants were exposed to nicotine, 10–1 mg/ml, from days 1 to 35, and characterized for cell morphology, viability/proliferation, alkaline phosphatase (ALP) activity and matrix mineralization.

Results: Low levels of nicotine, 10 and 50 ng/ml, representative of the plasma concentrations reported in smokers, did not cause significant effects in the cell behaviour, although a small induction in cell growth and functional activity appeared to occur. Higher nicotine levels, 0.01–1 mg/ml, within those attained in saliva through tobacco use, caused evident dose‐dependent effects in osteoblastic cell behaviour, i.e., a stimulatory effect in cell growth, ALP activity and matrix mineralization, at concentrations up to 0.2 mg/ml, and a deleterious effect at higher levels.

Conclusions: Considering the high tissue diffusion potential of nicotine, the results suggest the possibility of a direct modulation of the osteoblast activity as a contributing factor to the overall effect of nicotine in the bone microenvironment around dental implants.
Effect of platelet‐rich plasma on bone regeneration in dentistry: a systematic review
Authors: Plachokova Adelina S. , Nikolidakis Dimitris , Mulder Jan , Jansen John A. , Creugers Nico H. J.
Published: April 2008

Objective: To review systematically the reported effects of platelet‐rich plasma (PRP) on bone regeneration.

Material and methods: Up to June 2006, MEDLINE and Cochrane databases were explored with different combinations of three search terms: ‘PRP’, ‘bone regeneration’, ‘dentistry’ and their synonyms. Inclusion criteria: human controlled clinical trials designed to treat maxillofacial bony defects with application of PRP (test) or without PRP (control), including at least five patients with a follow‐up period of more than 3 months and using clinical assessment, radiography, histology and/or histomorphometry for evaluation. Literature search, selection of eligible articles and data extraction were carried out independently by two readers.

Results: The literature search revealed 108 references, of which 17 were selected for further analysis. Finally, nine articles fulfilling the inclusion criteria were selected for systematically review. Owing the substantial heterogeneity of the studies it was not possible to analyze the data statistically. An attempt was made to compare results from studies that used similar outcome measures by calculating and adding confidence intervals to the data presented in the original papers. Differences in treatment effects for periodontal defects in terms of clinical attachment level (CAL) were significant (ranging from 0.8 to 3.2 mm). The reported effects of PRP in sinus elevation (compared with their controls) were <10%.

Conclusion: We found evidence for beneficial effects of PRP in the treatment of periodontal defects. Evidence for beneficial effects of PRP in sinus elevation appeared to be weak. No conclusions can be drawn about other applications of PRP in dentistry.
Extramammary Paget’s disease presenting as alopecia neoplastica
Authors: Iwenofu O. Hans , Samie Faramarz H. , Ralston James , Cheney Richard T. , Zeitouni Nathalie C.
Published: April 2008

Extramammary Paget’s disease (EMPD) is a rare malignant neoplasm with a predilection for the apocrine‐rich anogenital skin and less commonly for the axilla. The tumor rarely occurs in non‐apocrine bearing regions where it is referred to as ectopic EMPD. Here, we report a case of a patient that presented with a poorly circumscribed, erythematous plaque with patchy alopecia on the scalp. Histology showed pagetoid infiltration of the epidermis by atypical single and nested cells with abundant amphophilic cytoplasm with nuclear hyperchromasia, extending along the adnexae. Immunohistochemistry showed that the tumor cells stained positively for mucicarmine, periodic acid schiff, cytokeratin‐7, polyclonal carcinoembryonic antigen, epithelial membrane antigen, gross cystic disease fluid protein, androgen receptor and Her‐2‐neu; and negatively for S‐100, HMB‐45, CDX‐2, thyroid transcription factor‐1, estrogen receptor and progesterone receptor, thus, establishing the diagnosis of ectopic EMPD. Subsequent workup showed no underlying malignancy. To our knowledge, we report the second case, and the first in the English literature, of an ectopic EMPD involving the scalp without any associated malignancy.
Desmocollin expression in oral atrophic lichen planus correlates with clinical behavior and DNA content
Authors: Mattila Riikka , Alanen Kalle , Syrjänen Stina
Published: April 2008

Background:  Oral lichen planus (OLP) is a chronic mucocutaneous inflammatory disease, with some tendency toward malignant transformation. Markers are needed to identify the lesions at risk.

Methods:  A series of 82 biopsies from 70 patients with atrophic OLP was analyzed for desmocollin‐1, E‐cadherin, cyclin‐dependent kinase 1 (cdk‐1) and Rad‐51 expression using immunohistochemistry and static DNA cytometry, with particular reference to clinical outcome.

Results:  Desmocollin‐1 and E‐cadherin expression were each detected in 24.4% (20/82) of the samples. Of the positive samples, only eight specimens expressed both desmocollin‐1 and E‐cadherin. Strong desmocollin‐1 and E‐cadherin expression was found in 8.5% and 3.7% of OLP biopsies, respectively. Desmocollin‐1 expression increased the risk of dysplasia 31.8‐fold (95% confidence intervals (CI) 3.6–280.9; p = 0.0001), while E‐cadherin was significantly related to cancer (odds ratio (OR) = 5.13; 95% CI 3.3–8.1; p = 0.001). In univariate survival analysis, desmocollin‐1 was a significant predictor of both cancer (log‐rank test; p = 0.033) and dysplasia (p = 0.0001), while E‐cadherin predicted the development of cancer (p = 0.0001). Neither cdk‐1 nor Rad‐51 had any predictive value. Importantly, desmocollin‐1 retained its value as the only independent predictor of dysplasia in the multivariate (Cox) model (adjusted Hazard Ratio (HR) = 44.13; 95% CI 3.7–525.6).

Conclusions:  In atrophic OLP, desmocollin‐1 is a powerful predictor of an important intermediate endpoint marker (dysplasia) in the causal pathway toward oral cancer.
Distribution of muscarinic receptor subtype M3 in melanomas and their metastases
Authors: Oppitz Matthias , Busch Christian , Garbe Claus , Drews Ulrich
Published: April 2008

Background:  Muscarinic acetylcholine receptors (mR) are involved in the regulation of cancer cell motility and cancer progression. mR have been shown in melanoma cell lines and cryostat sections of melanomas. To substantiate the experimental data, here the correlation of mR‐expression with invasive growth was studied on the cellular level by comparison with HMB‐45 immunoreactivity.

Methods:  mR were detected by a M3 subtype‐specific polyclonal antibody in normal skin, benign compound nevi, primary melanomas [nodular type, nodular malignant melanoma (NMM)] and metastases, and were compared with HMB‐45 staining in parallel paraffin sections.

Results:  The general staining pattern of anti‐M3 and HMB‐45 was similar with accentuation of zones with infiltrative growth. On the cellular level, only a subpopulation of the HMB‐45 positive melanoma cells expressed mR. Immunoreactivity was encountered in 3 of 15 nevi, in 9 of 14 NMM and in 10 of 14 melanoma metastases. Polymorphonuclear granulocytes also exhibited strong reactivity for anti‐M3.

Conclusion:  mR‐expression is associated with invasive migration of melanomas.
The Novel Sorting Nexin SNX33 Interferes with Cellular PrPSc Formation by Modulation of PrPc Shedding
Authors: Heiseke Andreas , Schöbel Susanne , Lichtenthaler Stefan F. , Vorberg Ina , Groschup Martin H. , Kretzschmar Hans , Schätzl Hermann M. , Nunziante Max
Published: April 2008

The cellular prion protein (PrPc) is a glycosyl‐phosphatidylinositol (GPI)‐anchored protein trafficking in the secretory and endocytic pathway and localized mainly at the plasma membrane. Conversion of PrPc into its pathogenic isoform PrPSc is associated with pathogenesis and transmission of prion diseases. Intramolecular cleavage in the middle, the extreme C‐terminal part or within the GPI anchor and shedding of PrPc modulate this conversion process by reducing the substrate for prion formation. These phenomena provide similarities with the processing of amyloid precursor protein in Alzheimer’s disease. Sorting nexins are a family of proteins with important functions in protein trafficking. In this study, we investigated the role of the newly described sorting nexin 33 (SNX33) in trafficking and processing of PrPc. We found that overexpression of SNX33 in neuronal and non‐neuronal cell lines resulted in increased shedding of full‐length PrPc from the plasma membrane and modulated the rate of PrPc endocytosis. This was paralleled by reduction of PrPSc formation in persistently and newly infected cells. Using deletion mutants, we demonstrate that production of PrP fragment N1 is not influenced by SNX33. Our data provide new insights into the cellular mechanisms of PrPc shedding and show how this can affect cellular PrPSc conversion.
Innovations in Aged Care: What are the first quality reports from the Transition Care Program in Australia telling us?
Authors: Masters Stacey , Halbert Julie , Crotty Maria , Cheney Fiona
Published: April 2008

Transition Care is a new program in Australia, jointly funded by the Commonwealth and State/Territory Governments. Implementation is undertaken by state health departments, in some cases through aged care organisations, against a set of key requirements. This paper examines reports from providers to reveal enablers and barriers to compliance with the requirements and to highlight emerging patterns of practice. The first 23 self‐reports were content analysed. Person‐centred and goal‐orientated care was evidenced. General practitioner, pharmacist and geriatrician involvement in care planning and review was low. While service agreements between Transition Care services, referring hospitals and community providers improved the efficiency of information transfer and discharge arrangements, these were rare, hindering entry and discharge from the program. Transition Care offers older people a flexible model of care. While the flexibility of the model is a strength, service providers are struggling to achieve integration with existing services.
Brief Report: Personal emergency alarms: What impact do they have on older people's lives?
Authors: De San Miguel Kristen , Lewin Gill
Published: April 2008

Objectives:  To determine if, how often and in what types of situations older people use personal alarms and to explore the impact of personal alarm technology on older people's lives.

Methods:  This study was retrospective and involved a mail‐out survey to 2610 users of the Silver Chain CareLink Personal Alarm Service.

Results:  Clients wear their alarm consistently around their home and in the garden; however, use is low in the shower/bath and in bed at night. Clients reported positive impacts in terms of: gaining faster assistance in an emergency, extending the time they are able to remain living at home, increasing their sense of security, reducing anxiety about falling and increasing confidence in performing everyday activities.

Conclusions:  Personal alarms have many positive impacts on the lives of older people.
Research: Issues of active ageing: Perceptions of older people with lifelong intellectual disability
Authors: Buys Laurie , Boulton‐Lewis Gillian , Tedman‐Jones Jan , Edwards Helen , Knox Marie , Bigby Christine
Published: April 2008

Objective(s):  The study aimed to investigate the lived experiences of older people with lifelong intellectual disability and to explore the meaning of active ageing for this group.

Methods:  Data were collected using semistructured interviews with 16 service users (people with lifelong intellectual disability aged 50+ years); 16 service providers and 16 key informal network members from regional/rural and urban areas in Queensland and Victoria.

Results:  Themes identified: being empowered, being actively involved, having a sense of security, maintaining skills and learning, having congenial living arrangements, having optimal health and fitness, being safe and feeling safe and having satisfying relationships and support.

Conclusions:  Service users wanted to ‘keep on keeping‐on’ in areas of life that gave them pleasure rather than discontinuing them because of age. They wanted more control over issues affecting their lives and to be given meaningful roles. Mental stimulation, companionship, reliable support and safety were valued by this group.
Research: Perceptions of personal safety among older Australians
Authors: Quine Susan , Morrell Stephen
Published: April 2008

Introduction:  There is public perception, partly attributable to the media, that older people are disproportionately the victims of crime and are greatly concerned for their personal safety.

Objectives:  To identify at a population level older people's perceptions of their personal safety in their home and separately in their neighbourhood, and the predictors of feeling safe in each setting.

Methods:  Logistic regression analysis of responses from randomly selected older Australians (65+ years) living independently in the community (n= 8881) to a cross‐sectional telephone general health survey.

Results:  The vast majority of respondents, although higher in men, reported feeling safe in their home (96%) and neighbourhood (92%) ‘all’ or ‘most’ of the time. Feeling safe did not decline with age. Significant predictors of feeling safe ‘all’ the time were identified and some gender differences were noted.

Conclusions:  The perception that older people are greatly concerned with their personal safety is not supported by these findings.
Research: Influence of different health‐care systems on health of older adults: A comparison of Hong Kong, Beijing urban and rural cohorts aged 70 years and older
Authors: Woo Jean , Zhang Xin Hua , Ho Suzanne , Sham Aprille , Tang Zhe , Fang Xiang Hua
Published: April 2008

Objective:  To explore the hypothesis that better health status of elderly populations is primarily determined by the provision of freely accessible health service at low or no cost to the user and a social welfare system.

Method:  Information was collected by questionnaire from surveys of three cohorts of elderly (70 years and older) Chinese. Data from two health‐care systems were compared: the low‐cost or free government‐subsidised system in Hong Kong, and the market‐orientated user‐pays system in urban (Beijing), and rural China.

Results:  The Beijing rural cohort had the best health profile, whereas the Hong Kong cohort had the worst, despite the better lifestyle practices in the Hong Kong and Beijing urban cohorts compared with the Beijing rural cohort, and higher socioeconomic status in the Beijing urban and Hong Kong cohorts. However, the Beijing rural cohort had the highest prevalence of functional limitations.

Conclusion:  While health‐care systems may affect life expectancy at birth, psychosocial, lifestyle and socioeconomic factors influence subsequent health status of elderly people in a complex manner.
Metal exchange in metallothioneins – a novel structurally significant Cd5 species in the alpha domain of human metallothionein 1a
Authors: Rigby Duncan Kelly E. , Kirby Christopher W. , Stillman Martin J.
Published: April 2008

Metallothioneins (MTs) are cysteine‐rich, metal‐binding proteins known to provide protection against cadmium toxicity in mammals. Metal exchange of Zn2+ ions for Cd2+ ions in metallothioneins is a critical process for which no mechanistic or structural information is currently available. The recombinant human α domain of metallothionein isoform 1a, which encompasses the metal‐binding cysteines between Cys33 and Cys60 of the α domain of native human metallothionein 1a, was studied. Characteristically this fragment coordinates four Cd2+ ions to the 11 cysteinyl sulfurs, and is shown to bind an additional Cd2+ ion to form a novel Cd5α‐MT species. This species is proposed here to represent an intermediate in the metal‐exchange mechanism. The ESI mass spectrum shows the appearance of charge state peaks corresponding to a Cd5α species following addition of 5.0 molar equivalents of Cd2+ to a solution of Cd4α‐MT. Significantly, the structurally sensitive CD spectrum shows a sharp monophasic peak at 254 nm for the Cd5α species in contrast to the derivative‐shaped spectrum of the Cd4α‐MT species, with peak maxima at 260 nm (+) and 240 nm (−), indicating Cd‐induced disruption of the exciton coupling between the original four Cd2+ ions in the Cd4α species. The 113Cd chemical shift of the fifth Cd2+ is significantly shielded (approximately 400 p.p.m.) when compared with the data for the Cd2+ ions in Cd4α‐MT by both direct and indirect 113Cd NMR spectroscopy. Three of the four original NMR peaks move significantly upon binding the fifth cadmium. Evidence from indirect 1H‐113Cd HSQC NMR spectra suggests that the coordination environment of the additional Cd2+ is not tetrahedral to four thiolates, as is the case with the four Cd2+ ions in the Cd4α‐MT, but has two thiolate ligands as part of its ligand environment, with additional coordination to either water or anions in solution.
Lipid‐induced conformational transition of the amyloid core fragment Aβ(28–35) and its A30G and A30I mutants
Authors: Nagarajan Sureshbabu , Ramalingam Kirubagaran , Neelakanta Reddy P. , Cereghetti Damiano M. , Padma Malar E. J. , Rajadas Jayakumar
Published: April 2008

The interaction of the β‐amyloid peptide (Aβ) with neuronal membranes could play a key role in the pathogenesis of Alzheimer’s disease. Recent studies have focused on the interactions of Aβ oligomers to explain the neuronal toxicity accompanying Alzheimer’s disease. In our study, we have investigated the role of lipid interactions with soluble Aβ(28–35) (wild‐type) and its mutants A30G and A30I in their aggregation and conformational preferences. CD and Trp fluorescence spectroscopic studies indicated that, immediately on dissolution, these peptides adopted a random coil structure. Upon addition of negatively charged 1,2‐dipalmitoyl‐syn‐glycero‐3‐phospho‐rac‐(glycerol) sodium salt (PG) lipid, the wild‐type and A30I mutant underwent reorganization into a predominant β‐sheet structure. However, no conformational changes were observed in the A30G mutant on interaction with PG. In contrast, the presence of zwitterionic 1,2‐dipalmitoyl‐syn‐glycero‐3‐phosphatidylcholine (PC) lipid had no effect on the conformation of these three peptides. These observations were also confirmed with atomic force microscopy and the thioflavin‐T assay. In the presence of PG vesicles, both the wild‐type and A30I mutant formed fibrillar structures within 2 days of incubation in NaCl/Pi, but not in their absence. Again, no oligomerization was observed with PC vesicles. The Trp studies also revealed that both ends of the three peptides are not buried deep in the vesicle membrane. Furthermore, fluorescence spectroscopy using the environment‐sensitive probe 1,6‐diphenyl‐1,3,5‐hexatriene showed an increase in the membrane fluidity upon exposure of the vesicles to the peptides. The latter effect may result from the lipid head group interactions with the peptides. Fluorescence resonance energy transfer experiments revealed that these peptides undergo a random coil‐to‐sheet conversion in solution on aging and that this process is accelerated by negatively charged lipid vesicles. These results indicate that aggregation depends on hydrophobicity and propensity to form β‐sheets of the amyloid peptide, and thus offer new insights into the mechanism of amyloid neurodegenerative disease.
MICROBIAL QUALITY OF FRESH‐CUT ICEBERG LETTUCE WASHED IN WARM OR COLD WATER AND IRRADIATED IN A MODIFIED ATMOSPHERE PACKAGE*
Authors: RAJKOWSKI KATHLEEN T. , FAN XUETONG
Published: April 2008

The microbial keeping quality of fresh‐cut iceberg lettuce was determined after being washed in either cold water (5C) for 3 min or warm water (47C) for 2 min followed by a cold water rinse (5C) and packaged in a modified atmosphere film bag. The lettuce samples were treated with gamma radiation to 0, 1 or 2 kGy while maintaining a refrigerated temperature (4C). The samples were analyzed for total aerobic, total coliform and Enterobacteriaceae counts after refrigerated storage up to 12 days. No difference in aerobic counts was observed between the hot‐ and cold‐washed samples immediately after washing. The coliform and Enterobacteriaceae counts were reduced by 2 log after the warm water wash and no difference for the cold water‐washed sample. The irradiation treatment at 1 kGy reduced the aerobic, coliform and Enterobacteriaceae counts by 2 log for the warm‐washed samples. At the 2‐kGy treatment level, the aerobic and coliform counts were reduced by 3 log for the cold‐washed lettuce, whereas the Enterobacteriaceae counts were reduced by only 2 log. The observed log reductions in bacterial counts after irradiation were maintained for 12 days when stored at 4C. The combination of a cold water wash and irradiation to 2 kGy had the best microbial keeping quality.

PRACTICAL APPLICATIONS

Fresh‐cut lettuce, when washed in either cold or warm water, shows neither an appreciable removal of the microbial load nor a significant increase in the keeping quality when compared with unwashed fresh‐cut controls. Placing the washed lettuce into modified atmosphere packaging (MAP) did not lessen the overall bacteriologic load, and after 12 days of storage at 4C, the microbial counts increased. However, gamma irradiation of the washed, MAP‐stored lettuce to a dose of 2 kGy significantly reduces the overall microbe count, thereby increasing both the shelf life and the safety of the produce. A 2‐kGy dose of gamma irradiation provides a pathogen‐free, long shelf life, fresh‐cut lettuce that is bacteriologically safer and sensorially indistinguishable from bagged, nonirradiated, fresh‐cut lettuce.
A REVIEW OF FOODBORNE DISEASE OUTBREAKS FROM 1996 TO 2005 IN HONG KONG AND ITS IMPLICATIONS ON FOOD SAFETY PROMOTION
Authors: CHAN S.F. , CHAN Z.C.Y.
Published: April 2008

Foodborne diseases are an important cause of morbidity and mortality and are a growing global concern. A series of recent food safety problems has raised much public concern in the Hong Kong Special Administrative Region
*
. Despite the fact that many resources have been spent on food safety promotion, there has been no noticeable impact on the rising trend of local foodborne disease outbreaks. This quantitative research study aimed to identify what should be targeted in the current local food safety promotion. It presented a descriptive analysis of local official statistics from 1996 to 2005, followed by a comparison of foodborne disease outbreaks and food safety measures in some Asian places. Results found that about 72% of total local confirmed outbreaks were caused by Vibrio parahaemolyticus and Salmonella spp., while around 46% of the total outbreaks were due to inadequate cooking and contamination by raw food. It suggests that food safety promotion targeted on these factors may greatly reduce local foodborne disease outbreaks. Further elaboration could have been given if detailed breakdown in each outbreak had been provided.

PRACTICAL APPLICATIONS

Based on the official figures, the annual incidence of local foodborne disease outbreaks and the number of victims affected are generally increasing despite the fact that many resources and much manpower have been spent on food safety promotion and on investigating each foodborne disease outbreak in the Hong Kong Special Administrative Region. Official statistics for the past decade indicate that the majority of foodborne disease outbreaks has been dominated by some causative agents and contributing factors. Under limited resources, instead of providing some general food safety promotion programs, it suggests that the local food safety promotion should be targeted on these dominant factors. This may greatly reduce the number of outbreaks and victims affected. If this were carried out, not only could the economic burden in this health sector be reduced, but the public health campaigns could also be conducted more efficiently, and more resources could be released to prepare for combating other newly emerging diseases.
A new mode of river basin management in South Korea
Authors: Lee Seungho , Kim Sung
Published: April 2008

This study aims to explore a new mode of river basin management in South Korea by evaluating the current river basin management system and taking lessons from the British and French cases. This research is based on literature reviews and interviews in the United Kingdom, France and South Korea. The British case emphasizes the importance of regulatory framework and limitations of public participation. The French experience epitomizes the empowerment of river basin organizations. The new system in South Korea includes an enactment of water law, a set‐up of the National Water Council, the River Basin Authorities and the River Basin Committees. The new model will not be established soon but needs to take a step‐by‐step approach to minimize social conflicts, accommodate diverse opinions in society and satisfy a variety of demands.
A randomised controlled trial comparing fresh, dried, and dried‐then‐rehydrated temporalis fascia in myringoplasty
Authors: Loock J.W. , Naude N.
Published: April 2008

Objectives:  To determine whether the way in which temporalis fascia is treated during myringoplasty affects the rate of successful perforation closure.

Design:  A randomised controlled trial.

Setting:  A tertiary ENT Department within the Tygerberg Academic Hospital.

Participants:  One hundred and fifty patients with perforations between 30% and 70% of the surface area of the eardrum undergoing elective myringoplasty were randomised into three groups by the way in which the temporalis fascia used was treated prior to insertion: fresh fascia; dried fascia; and fascia which was dried and then rehydrated.

Main outcome measures:  The outcome measure was intactness of the tympanic membrane 6 weeks after surgery. Preoperative and follow‐up audiometry was obtained, but was not evaluated as an outcome measure.

Results:  Successful closure of the perforation was achieved in 89% in the dried fascia group (42 of 47 patients), 84% in the fresh fascia group (37 of 44 patients), and 85% in the dried and rehydrated group (39 of 46 patients). The study showed no statistically significant difference between the three groups (P = 0.728). The study would have to had more than 800 patients in each group to have the power to show a 5% difference in take rates.

Conclusions:  While the dessication of temporalis fascia prior to use in myringoplasy results in degeneration of cellular and stromal elements histologically, this does not affect the successful closure of perforations. Clinicians should feel free to prepare the fascia in whichever way they find easiest to work with.
The association of psycho‐social factors and survival in head and neck cancer
Authors: Mehanna H.M. , De Boer M.F. , Morton R.P.
Published: April 2008

Objective:  Update a previous review examining associations between psycho‐social factors and survival in head and neck cancer patients.

Data sources:  Searched Cochrane, Psych info and Embase for the period from 1 January 1995 to 1 June 2007, as well as personal and article reference lists and article archives.

Study selection:  Identified articles assessed by consensus for eligibility using following criteria: survival as outcome measure; psycho‐social factors as prognostic indicators; results specifically for head and neck cancer patients, not including oesophageal or thyroid cancer. Seven of 64 articles fulfilled criteria.

Data extraction:  Data abstracted independently by two reviewers using pre‐determined proformas. Quality also rated using Scottish Intercollegiate Guidelines Network 50 tool.

Data synthesis:  At baseline, expression of intense psycho‐social complaints, higher self‐perceived physical ability and self‐reported high physical functioning were significantly associated with increased survival.

Uncertainty about the diagnosis and treatment was found to be a negative prognostic indicator, as was being single, poor cognitive function, baseline fatigue and alcoholism.

Overall quality of life and head and neck pain 12 months after date of diagnosis were found to be significantly associated with survival in one study. However, overall quality of life and depression at the time of diagnosis were not.

Conclusions:  There appears to be some association between selected psycho‐social factors and long‐term survival from head and neck cancer. However this relationship is currently neither strong nor proven, requiring examination by multi centred trials with standardisation of research definitions and methodologies, and examination of post‐treatment psycho‐social factors.
A new technique during septoplasty to prevent saddle nose
Authors: Raeessi M.A. , Farhadi M. , Shirazi A. , Ajalloueyan M. , Karimi Yazdi A.R.
Published: April 2008

Keypoints

During septoplasty, especially in patients with severe deviation of the nasal septum, there is the risk of septal instability, which may result in a saddle nose deformity. Therefore, prevention of this unwanted outcome is very important and removes surgeon’s anxieties.

This article describes a simple technique during septoplasty to prevent the development of this serious complication.

In this surgical technique, the dislocated nasal septum is lifted and stabilised with a temporary traction suture. This traction suture holds the mobile septal cartilage in the proper position to restore and support the nasal dorsum and provides it with a normal contour.

The advantages of this technique are that it is (i) easy to perform, (ii) not time‐consuming, (iii) is less traumatic compared to other methods, (iv) is comfortable for the patient and (v) provides long‐term stability.
Nurse‐led adult ENT pre‐operative assessment
Authors: Bhutta M.F. , Boutchier B.J. , Latif M.A.
Published: April 2008

Keypoints

Pre‐operative assessment in some ENT departments is now nurse‐led rather than doctor‐led.

Appropriately trained nursing staff can perform medical aspects of pre‐operative assessment to the same or a better standard than a doctor.

Almost all patients are satisfied with a nurse‐led pre‐operative assessment, and in some cases they prefer it.
Activity Switches of Rhodopsin†
Authors: Ritter Eglof , Elgeti Matthias , Bartl Franz J.
Published: April 2008

Rhodopsin, the visual pigment of the rod photoreceptor cell contains as its light‐sensitive cofactor 11‐cisretinal, which is bound by a protonated Schiff base between its aldehyde group and the Lys296 side chain of the apoprotein. Light activation is achieved by 11‐cis to all‐transisomerization and subsequent thermal relaxation into the active, G protein‐binding metarhodopsin II state. Metarhodopsin II decaysviatwo parallel pathways, which both involve hydrolysis of the Schiff base eventually to opsin and released all‐transretinal. Subsequently, rhodopsin's dark state is regenerated by a complicated retinal metabolism, termed the retinoid cycle. Unlike other retinal proteins, such as bacteriorhodopsin, this regeneration cycle cannot be short cut by light, because blue illumination of active metarhodopsin II does not lead back to the ground state but to the formation of largely inactive metarhodopsin III. In this review, mechanistic details of activating and deactivating pathways of rhodopsin, particularly concerning the roles of the retinal, are compared. Based on static and time‐resolved UV/Vis and FTIR spectroscopic data, we discuss a model of the light‐induced deactivation. We describe properties and photoreactions of metarhodopsin III and suggest potential roles of this intermediate for vision.
Clinical investigation of a point‐of‐care blood ammonia analyzer
Authors: Goggs Robert , Serrano Sergio , Szladovits Balazs , Keir Iain , Ong Ryan , Hughes Dez
Published: April 2008

Background:Hyperammonemia has frequently been implicated in the pathogenesis of hepatic encephalopathy. Blood ammonia determination requires minimal delay between sampling and analysis for accurate results.

Objectives:The aim of this study was to investigate the PocketChem BA, a new point‐of‐care (POC) blood ammonia analyzer for clinical use by determining machine precision, linearity, repeatability, and accuracy.

Methods:Coefficients of variation were determined by repeated measurement of 2 control solutions. Linearity was investigated by testing serial dilutions of a stock solution. For accuracy, samples from clinical cases were used to compare the results on the PocketChem BA with those obtained using an enzymatic reference method for canine plasma. Canine and feline patients were consecutively enrolled if blood ammonia was assayed and samples could be analyzed shortly after collection. Classification of results (as normal or high, using 100 μmol/L as a cutoff value), Bland–Altman and Deming regression plots, and intraclass correlation coefficients were used to compare the methods. Stability of samples and test strips also was assessed over time.

Results:Coefficients of variation were 10.6% and 4.8% for low and high controls, respectively. Concentrations of ammonia in diluted stock solutions correlated positively with mean measured concentrations (Pearson coefficient 0.988,P<.001). Of the 54 samples obtained from 38 dogs and 4 cats, 41 had ammonia concentrations within the readable range. Results from the POC analyzer and the reference method were correlated positively (intraclass coefficient 0.800, 95% confidence interval 0.655–0.888), with the POC analyzer having negative constant and proportional biases. The methods agreed in the classification of 45/54 (83.3%) samples, with 7 false negative results on the POC analyzer. Results of repeated sample and strip analyses at 1 and 24 hours were significantly different (P<.05) from those at 0 hour.

Conclusions:The PocketChem BA has acceptable precision, adequate linearity, and satisfactory agreement with a reference method, but negative constant and proportional biases. The POC analyzer may be suitable for clinical use in patients suspected of having hepatic encephalopathy, using a lower reference limit of 60 μmol/L to decrease false negative results.
Ethinyl oestradiol administration in women suppresses synthesis of collagen in tendon in response to exercise
Authors: Hansen Mette , Koskinen Satu O. , Petersen Susanne G. , Doessing Simon , Frystyk Jan , Flyvbjerg Allan , Westh Eva , Magnusson S. Peter , Kjaer Michael , Langberg Henning
Published: April 2008

Women are at greater risk than men of sustaining certain kinds of injury and diseases of collagen‐rich tissues. To determine whether a high level of oestradiol has an acute influence on collagen synthesis in tendons at rest and in response to exercise, one‐legged kicking exercise was performed for 60 min at 67% of maximum power by healthy, young oral contraceptive (OC) users when circulating synthetic (ethinyl) oestradiol was high (n= 11, HE‐OC) and compared to similar women who had never used OCs when circulating endogenous oestrogen was low (n= 12, LE‐NOC). Interstitial fluid was collected 24 h post‐exercise through microdialysis catheters placed anterior to the patellar tendon in both legs and subsequently analysed for the amino‐terminal propeptide of type I collagen (PINP), a marker of tendon collagen synthesis. To determine the long‐term effect of OC usage, patellar tendon cross‐sectional area (CSA) was measured by magnetic resonance imaging (MRI). A lower exercise‐induced increase in tendon collagen synthesis was observed in HE‐OC than in LE‐NOC (ΔPINP (mean ±s.e.m.) 1.5 ± 5.3versus24.2 ± 9.4 ng ml−1,P< 0.05). Furthermore, serum and the interstitial peritendinous tissue concentrations of insulin‐like growth factor I (IGF‐I) and IGF‐binding proteins showed a reduced bioavailability in HE‐OC compared with results in LE‐NOC. No difference in patellar tendon CSA was observed between groups. In conclusion, the selective increase in tendon collagen synthesis in LE‐NOC but not HE‐OC 24 h post‐exercise is consistent with the hypothesis that oestradiol inhibits exercise‐induced collagen synthesis in human tendon. The mechanism behind this is either a direct effect of oestradiol, or an indirect effect via a reduction in levels of free IGF‐I. However, the data did not indicate any long‐term effect on tendon size associated with chronic OC use.
Phosphocreatine as an energy source for actin cytoskeletal rearrangements during myoblast fusion
Authors: O'Connor Roddy S. , Steeds Craig M. , Wiseman Robert W. , Pavlath Grace K.
Published: April 2008

Myoblast fusion is essential for muscle development, postnatal growth and muscle repair after injury. Recent studies have demonstrated roles for actin polymerization during myoblast fusion. Dynamic cytoskeletal assemblies directing cell–cell contact, membrane coalescence and ultimately fusion require substantial cellular energy demands. Various energy generating systems exist in cells but the partitioning of energy sources during myoblast fusion is unknown. Here, we demonstrate a novel role for phosphocreatine (PCr) as a spatiotemporal energy buffer during primary mouse myoblast fusion with nascent myotubes. Creatine treatment enhanced cell fusion in a creatine kinase (CK)‐dependent manner suggesting that ATP‐consuming reactions are replenished through the PCr/CK system. Furthermore, selective inhibition of actin polymerization prevented myonuclear addition following creatine treatment. As myotube formation is dependent on cytoskeletal reorganization, our findings suggest that PCr hydrolysis is coupled to actin dynamics during myoblast fusion. We conclude that myoblast fusion is a high‐energy process, and can be enhanced by PCr buffering of energy demands during actin cytoskeletal rearrangements in myoblast fusion. These findings implicate roles for PCr as a high‐energy phosphate buffer in the fusion of multiple cell types including sperm/oocyte, trophoblasts and macrophages. Furthermore, our results suggest the observed beneficial effects of oral creatine supplementation in humans may result in part from enhanced myoblast fusion.
How do tonic glutamatergic synapses evade receptor desensitization?
Authors: Pang Ji‐Jie , Gao Fan , Barrow Andrew , Jacoby Roy A. , Wu Samuel M.
Published: April 2008

Photoreceptor output synapses are the best known tonic chemical synapses in the nervous system, in which glutamate is continuously released in darkness, activating AMPA/kainate receptors in postsynaptic neurons. It has been shown that glutamate receptors in certain types of second‐order retinal cells are largely desensitized in darkness, leading to small postsynaptic currents and reduced response dynamic ranges. Here we show that the tonic glutamatergic synapses between photoreceptors and rod‐dominated hyperpolarizing bipolar cells (HBCRs) in the salamander retina evade postsynaptic receptor desensitization by using (1) multiple invaginating ribbon junctions as releasing sites for low‐frequency, synchronized multiquantal release at each site; and (2) the GluR4 AMPA receptors as the postsynaptic receptors. The multiquantal events exhibit faster decay time than the GluR4 receptor desensitization time constant and therefore self‐desensitization is minimized, and the average inter‐event duration in darkness is much longer than the GluR4 desensitization recovery time and thus mutual desensitization is avoided. Consequently, the HBCRs are not desensitized in darkness, allowing light signals to be encoded by the full operating range of the glutamate‐gated postsynaptic currents. Our study illustrates for the first time how a tonic glutamatergic synapse avoids postsynaptic receptor desensitization, a strategy that may be shared by many other synapses in the nervous system that need extended operation capacity.
Cyclothiazide: a subunit‐specific inhibitor of GABACreceptors
Authors: Xie An , Song Xiangqian , Ripps Harris , Qian Haohua
Published: April 2008

We tested the effects of cyclothiazide (CTZ), an agent used to block desensitization of AMPA‐type glutamate receptors, on heterologously expressed GABACreceptors formed by homomeric ρ subunits. CTZ inhibition of GABACreceptors was subunit specific; it produced a dose‐dependent reduction of the GABA‐elicited current on homomeric ρ2 receptors with an IC50of about 12 μm, but had no significant effect on homomeric ρ1 receptors. This differential sensitivity was attributable to a single amino acid located on the second transmembrane domain of the ρ subunits. Mutating the residue at this position from serine to proline on the ρ2 subunit eliminated CTZ sensitivity, whereas switching proline to serine on the ρ1 subunit made the receptor CTZ sensitive. The inhibitory properties of CTZ were consistent with its action as a channel blocker on the receptors formed by ρ2 subunits. The effect showed a small degree of voltage dependence, and was due mainly to a non‐competitive mechanism that reduced the maximum response elicited by GABA. In addition, the prominent membrane current rebound when co‐application of GABA and CTZ was terminated suggests that the binding site for CTZ on the GABACreceptor is distinct from that for GABA, and that CTZ acts as a non‐competitive antagonist on the GABACreceptor. CTZ inhibited the open channel of the GABACreceptor with a time constant of about 0.4 s, but the kinetics were ∼10‐fold slower when GABA is absent. The ability of CTZ to interact with various types of neurotransmitter receptors indicates that the drug has multiple actions in the CNS.
Defective regulation of contractile function in muscle fibres carrying an E41K β‐tropomyosin mutation
Authors: Ochala Julien , Li Meishan , Ohlsson Monica , Oldfors Anders , Larsson Lars
Published: April 2008

A novel E41K β‐tropomyosin (β‐Tm) mutation, associated with congenital myopathy and muscle weakness, was recently identified in a woman and her daughter. In both patients, muscle weakness was coupled with muscle fibre atrophy. It remains unknown, however, whether the E41K β‐Tm mutation directly affects regulation of muscle contraction, contributing to the muscle weakness. To address this question, we studied a broad range of contractile characteristics in skinned muscle fibres from the two patients and eight healthy controls. Results showed decreases (i) in speed of contraction at saturated Ca2+ concentration (apparent rate constant of force redevelopment (ktr) and unloaded shortening speed (V0)); and (ii) in contraction sensitivity to Ca2+ concentration, in fibres from patients compared with controls, suggesting that the mutation has a negative effect on contractile function, contributing to the muscle weakness. To investigate whether these negative impacts are reversible, we exposed skinned muscle fibres to the Ca2+ sensitizer EMD 57033. In fibres from patients, 30 μm of EMD 57033 (i) had no effect on speed of contraction (ktr and V0) at saturated Ca2+ concentration but (ii) increased Ca2+ sensitivity of contraction, suggesting a potential therapeutic approach in patients carrying the E41K β‐Tm mutation.
Reconstitution of Contractile FtsZ Rings in Liposomes
Authors: Osawa Masaki , Anderson David E. , Erickson Harold P.
Published: April 2008

FtsZ is a tubulin homolog and the major cytoskeletal protein in bacterial cell division. It assembles into the Z ring, which contains FtsZ and a dozen other division proteins, and constricts to divide the cell. We have constructed a membrane-targeted FtsZ (FtsZ-mts) by splicing an amphipathic helix to its C terminus. When mixed with lipid vesicles, FtsZ-mts was incorporated into the interior of some tubular vesicles. There it formed multiple Z rings that could move laterally in both directions along the length of the liposome and coalesce into brighter Z rings. Brighter Z rings produced visible constrictions in the liposome, suggesting that FtsZ itself can assemble the Z ring and generate a force. No other proteins were needed for assembly and force generation.
Relevance of clotting tests in liver disease
Authors: Thachil J
Published: April 2008

Liver disease is associated with impairment of the haemostatic function due to the abnormal and decreased synthesis of the clotting factors. It is thus only logical to have considered assessment of the clotting profile (to include prothrombin time (PT) and activated partial thromboplastin time (aPTT)) to be an integral part of the comprehensive assessment of a patient who presents with liver impairment. Laboratory abnormalities of coagulation are considered to be a predictive risk factor for bleeding, but patients with liver disease do not have bleeding pattern as those who have coagulation factor deficiencies. Recent experiments have cast doubts over the use of PT and aPTT as a marker of bleeding in liver disease and the use of such tests to decide the need for plasma replacement before interventions like liver biopsy. This article reviews the relevance of the clotting profile in liver disease, the other factors involved in the haemostatic failure associated with it, and the technical problems in the interpretation of these results. Most importantly, it stresses the need for more trials to help us guide the management of bleeding in patients with liver impairment.
Can a small park preserve its flora? A historical study of Bic National Park, Quebec
Authors: Lavoie Claude , Saint-Louis Annie
Published: April 2008

We reconstructed the 100 year history of the botanical composition of a small (19 km2) park (Bic National Park, Bic/St. Fabien, Quebec) located within an agricultural landscape. Using 64 historical sources and a botanical field survey, we documented changes in the native and exotic vascular flora that occurred before and after the creation of the park in 1984. We evaluated how many native species were lost from 1984 to 2005, and the number of exotic species that became established during the same period. A total of 585 plant taxa were found in Bic National Park before its creation, of which 488 (83%) were native. The park harbours more taxa today (710) than in the past, but the proportion of exotic taxa has increased significantly (from 16% to 25%) since 1984. Despite its small area, Bic National Park has very successfully preserved its flora during its 21 year history. Thirteen species have likely been extirpated from the area occupied by the park. However, 12 of these 13 species have not been seen since at least 1957, so they were probably extirpated before the creation of the park. On the other hand, the creation of the park did not stop the introduction of exotic species. Land-use changes, an increase in the number of visitors, and horticultural plantings are probably the main causes explaining the rise in the number of exotic taxa observed during the last 21 years. A small park located far from urban centres may preserve its flora, but is not necessarily a bastion against exotic species.