PubMed Health⌕ Search

Biomedical subjects

M Davis

Publications and source records attributed to M Davis.

At least 37 records · Page 2Linked to original sources
PubMed2004

Outcome and staging evaluation in malignant germ cell tumors of the ovary in children and adolescents: an intergroup study.

PURPOSE: The aim of this study was to perform an evaluation of outcome and the role of surgical staging components in malignant germ cell tumors (GCT) of the ovary in children and adolescents. METHODS: From 1990 to 1996, 2 intergroup trials for malignant GCT were undertaken by Pediatric Oncology Group (POG) and Children's Cancer Study Group (CCG). Stage I-II patients were treated with surgical resection and 4 cycles of standard dose cisplatin (100 mg/m2/cycle), etoposide, and bleomycin (PEB) chemotherapy. Stage III-IV patients were treated with surgical resection and randomly assigned to chemotherapy with PEB or high-dose cisplatin (200 mg/m2/cycle) with etoposide and bleomycin (HDPEB). Patients unresectable at diagnosis had second-look operation after 4 cycles of chemotherapy if residual tumor was seen on imaging studies. IRB approval of the protocols was obtained at each participating institution. An analysis of outcome data, operative notes, and pathology reports in girls with ovarian primary site was done for this report. RESULTS: There were 131 patients with ovarian primary tumors of 515 entered on these studies. Mean age was 11.9 years (range, 1.4 to 20 years). Six-year survival rate was stage, I 95.1%; stage II, 93.8%; stage III, 98.3%; stage IV, 93.3%. In only 3 of 131 patients were surgical guidelines followed completely. Surgical omissions resulting in protocol noncompliance resulted from failure to biopsy bilateral nodes (97%), no omentectomy (36%), no peritoneal cytology (21%), no contralateral ovary biopsy (59%). More aggressive procedure than recommended by guidelines included total hysterectomy and bilateral salpingo-oophorectomy in 6 patients and retroperitoneal node dissection in 10 patients. Correlation of gross operative findings with pathology results was carried out for ascites, lymph nodes, implants, omentum, and contralateral ovary. CONCLUSIONS: Pediatric ovarian malignant GCT (stages I-IV) have excellent survival with conservative surgical resection and platinum-based chemotherapy. Survival appears to have been unaffected by deviations from surgical guidelines. New surgical guidelines are proposed based on correlation of gross findings, histology, and outcome in these intergroup trials.

Adolescent↗
PubMed2004

5-hydroxytryptamine1A-like receptor activation in the bed nucleus of the stria terminalis: electrophysiological and behavioral studies.

The anteriorlateral bed nucleus of the stria terminalis (BNST AL) and the serotonergic system are believed to modulate behavioral responses to stressful and/or anxiogenic stimuli. However, although the BNST AL receives heavy serotonergic innervation, the functional significance of this input is not known. Data obtained from in vitro whole-cell patch clamp recording in the rat BNST slice show that exogenous application of 5-hydroxytryptamine (5-HT) evoked a heterogeneous response in BNST AL neurons. The principal action of 5-HT in this region was inhibitory, evoking a membrane hyperpolarization (5-HTHyp) and a concomitant reduction in input resistance in the majority of neurons tested. The broad-spectrum 5-HT1 agonist, 5-carboxamindotryptamine (5-CT), but not R(+/-)8-hydroxydipropylaminotetralin hydrobromide (8-OH-DPAT), mimicked the 5-HTHyp response in the BNST. Moreover, the outward current mediating 5-HTHyp was inwardly rectifying and sensitive to the G protein activated inwardly rectifying K+ (G IRK) channel blocker, tertiapin-Q. In the CNS 5-HT1A receptors are thought to couple to GIRK channels, suggesting that 5-HTHyp in BNST AL neurons was mediated by activation of 5-HT1A-like receptors. This was confirmed by the blockade of both 5-HTHyp and 5-CTHyp by the specific 5-HT1A receptor antagonist N-[2-[4-(2-methoxyphenyl)-1-piperazinyl]ethyl]-N-2-pyridinylcyclohexanecarboxamide maleate salt (WAY100635 200nM). Furthermore, an in vivo examination of the functional consequences of 5-HT1A-like induced inhibition of BNST neurons revealed that infusion of 5-CT into the BNST significantly reduced the acoustic startle response, without affecting the general motor activity of the animals. These data point to the possibility that 5-HT1A mediated inhibition of the BNST AL could contribute to an anxiolytic action. Hence, we propose that in response to stressful stimuli, enhanced levels of 5-HT in the BNST AL plays a critical homeostatic role in feedback inhibition of the anxiogenic response to these stimuli.

Afferent Pathways↗
PubMed2004

Use of gay Internet sites and views about online health promotion among men who have sex with men.

In May-June 2002, 4,974 men who have sex with men (MSM), average age 31 years, completed a self-administered questionnaire online accessed through two popular gay Internet sites in the UK (gaydar and gay.com UK). Most men were white (95%), employed (83%), lived in the UK (91%) and self-identified as gay (85%). Nearly half (46%) had not been tested for HIV, while 6% said they were HIV-positive. One-third (31%) reported high-risk sexual behaviour in the previous three months, i.e. unprotected anal intercourse with a partner of unknown or discordant HIV status. Nearly all the men (82%) had looked for a sexual partner on the Internet and three-quarters had been doing so for more than a year. Almost half the men (47%) said they preferred to meet men through the Internet rather than in bars or other 'offline' venues. Although nearly 40% of men said the most important reason for using these Internet sites was to find sexual partners, a further 17% said they primarily used them to have contact with other men, 16% because they were bored, 12% for entertainment, 4% because they were lonely and 3% because they were addicted to it. The majority of men in this survey had favourable attitudes towards online health promotion. Most men thought that Internet sites should allow health workers into chat-rooms (75%); would click on a banner to find out about sexual health (78%); and said if they met a health worker in a chat-room they would find out what they had to say (84%). In multivariate analysis, being HIV-positive, older age and high-risk sexual behaviour were all independently associated with an increased frequency of using the Internet to look for sex (p<0.05). The Internet has emerged as an important meeting place for men who have sex with men. As online HIV prevention initiatives are developed it will be important to monitor the extent to which the favourable attitudes seen here are reflected in preventive behaviours.

Adult↗
PubMed2004

Reflecting on the experience of interviewing online: perspectives from the Internet and HIV study in London.

This paper considers some of the strengths and weaknesses of conducting synchronous online interviews for qualitative research. It is based on a study among gay/bisexual men that used both qualitative and quantitative methods to explore the association between seeking sex through the Internet and HIV transmission risk. Between June 2002 and January 2004, 128 gay/bisexual men living in London were interviewed one-to-one by the first author (MD) about their experience of using the Internet to find sexual partners and negotiating condom use for anal sex. Thirty-five men were interviewed online, while 93 were interviewed face-to-face (i.e. offline). This paper draws on MD's experience of conducting these interviews--both online and face-to-face. Synchronous online interviews have the advantage of being cheap, convenient and attractive to people who do not like face-to-face interviews. However, some of the social conventions and technical limitations of computer-mediated-communication can introduce ambiguity into the online dialogue. To minimize this ambiguity, both interviewer and interviewee have to edit their online interaction. One of the distinctive features of the online interview is that it emerges as a form of textual performance. This raises fundamental questions about the suitability of the synchronous online interview for exploring sensitive topics such as risky sexual behaviour.

Adult↗
PubMed2004

Trends in sexual behaviour among London homosexual men 1998-2003: implications for HIV prevention and sexual health promotion.

OBJECTIVES: To examine changes in sexual behaviour among London homosexual men between 1998 and 2003 by type and HIV status of partner. METHODS: Homosexual men (n=4264) using London gyms were surveyed annually between 1998 and 2003 (range 498-834 per year). Information was collected on HIV status, unprotected anal intercourse (UAI) in the previous 3 months, and type of partner for UAI. High risk sexual behaviour was defined as UAI with a partner of unknown or discordant HIV status. RESULTS: Between 1998 and 2003, the percentage of men reporting high risk sexual behaviour with a casual partner increased from 6.7% to 16.1% (adjusted odds ratio (AOR) 1.36 per year, 95% confidence interval (CI) 1.26 to 1.46, p <0.001). There was no significant change in the percentage of men reporting high risk sexual behaviour with a main partner alone (7.8%, 5.6%, p=0.7). These patterns were seen for HIV positive, negative and never tested men alike regardless of age. The percentage of HIV positive men reporting UAI with a casual partner who was also HIV positive increased from 6.8% to 10.3% (AOR 1.27, 95% CI 1.01 to 1.58, p <0.05). CONCLUSION: The increase in high risk sexual behaviour among London homosexual men between 1998 and 2003 was seen only with casual and not with main partners. STI/HIV prevention campaigns among London homosexual men should target high risk practices with casual partners since these appear to account entirely for the recent increase in high risk behaviour.

Adult↗
PubMed2003

Evaluation of nutritional status in advanced metastatic cancer.

Consecutive cancer referrals to a palliative medicine program were evaluated to assess nutritional status using a standard protocol. The study included 352 patients (180 men, 172 women; median age 61 years, range 22-94 years). The most common diagnosis was lung cancer. All had metastatic disease, 139 with gastrointestinal involvement. The most common gastrointestinal symptoms were weight loss ( n=307), anorexia ( n=285), and early satiety ( n=243). Of those with any weight loss, 71% had lost >or0% of their pre-illness weight. The most common factor identified which might have contributed to weight loss was hypophagia ( n=275/307). Men had lost weight more often and to a greater extent than women. Triceps skinfold (TSF) was measured in 337: 51% had values that suggested severe fat deficiency. Upper mid-arm muscle area (AMA) was measured in 349: 30% had evidence of significant muscle mass reduction. The body mass index (BMI) was normal or increased in most patients. Calculated resting energy expenditure (REE) ( n=324) was high in 41%. C-reactive protein was elevated in 74% of those measured ( n=50). We conclude that: (1).most of this group of cancer patients referred to palliative medicine had severe weight loss; (2).there was a gender difference in the severity and type of weight loss; (3).males lost more weight overall and more muscle than females; (4).males with any degree of weight loss had a higher REE than females; (5).a significant correlation existed between the time from diagnosis to death and the severity of weight loss in the prior month; (6).BMI was normal in most patients, suggesting precancer diagnosis obesity; and (7).both TSF and AMA correlated well with body composition of both fat and protein as determined by bioelectrical impedance.

Adult↗
PubMed2003

A locus on chromosome 15q for a dominantly inherited nemaline myopathy with core-like lesions.

Nemaline myopathy is a congenital neuromuscular disorder characterized by muscle weakness and the presence of nemaline rods. Five genes have now been associated with nemaline myopathy: alpha-tropomyosin-3 (TPM3), alpha-actin (ACTA1), nebulin (NEB), beta-tropomysin (TPM2) and troponin T (TNNT1). In addition, mutations in the ryanodine receptor gene (RYR1) have been associated with core-rod myopathy. Here we report linkage in two unrelated families, with a variant of nemaline myopathy, with associated core-like lesions. The clinical phenotype consists of muscle weakness in addition to a peculiar kind of muscle slowness. A genome-wide scan revealed a locus for nemaline myopathy with core-like lesions on chromosome 15q21-q23 for both families. Combining the two families gave a two-point LOD score of 10.65 for D15S993. The alpha-tropomyosin-1 gene (TPM1) located within this region is the strongest candidate gene. However, no mutations were found in the protein-coding region of TPM1, although small deletions or mutations in an intron cannot be excluded. The critical region contains few other candidate genes coding for muscle proteins and several genes of unknown function, and has not yet been sequenced completely. The novel phenotype of nemaline myopathy in the two presented families corresponds to an also novel, as yet uncharacterized, genotype.

Adolescent↗
PubMed2003

Phobic anxiety in 11 nations. Part I: Dimensional constancy of the five-factor model.

The Fear Survey Schedule-III (FSS-III) was administered to a total of 5491 students in Australia, East Germany, Great Britain, Greece, Guatemala, Hungary, Italy, Japan, Spain, Sweden, and Venezuela, and submitted to the multiple group method of confirmatory analysis (MGM) in order to determine the cross-national dimensional constancy of the five-factor model of self-assessed fears originally established in Dutch, British, and Canadian samples. The model comprises fears of bodily injury-illness-death, agoraphobic fears, social fears, fears of sexual and aggressive scenes, and harmless animals fears. Close correspondence between the factors was demonstrated across national samples. In each country, the corresponding scales were internally consistent, were intercorrelated at magnitudes comparable to those yielded in the original samples, and yielded (in 93% of the total number of 55 comparisons) sex differences in line with the usual finding (higher scores for females). In each country, the relatively largest sex differences were obtained on harmless animals fears. The organization of self-assessed fears is sufficiently similar across nations to warrant the use of the same weight matrix (scoring key) for the FSS-III in the different countries and to make cross-national comparisons feasible. This opens the way to further studies that attempt to predict (on an a priori basis) cross-national variations in fear levels with dimensions of national cultures.

Adolescent↗
PubMed2003

The multi-disciplinary evaluation of a national agri-environment scheme.

With an increasing amount of public funds being spent on agri-environmental schemes effective methods have to be developed to evaluate them. As many schemes have multiple objectives there is a need for a multi-disciplinary approach to any evaluation. A method was developed to assess the degree to which ecological, landscape, historical and access objectives for the Countryside Stewardship Scheme (CSS) in England have been met. The method used a sample of 484 agreements for which data were collected from surveys, a desk study and an interview with the agreement holder. These data were then evaluated by an expert team of an ecologist, landscape architect, landscape historian, and a social scientist specializing in rural affairs. The team were subsequently brought together with a Chair to discuss their findings for each agreement, allocating scores for each of five criteria: agreement negotiation; appropriateness, environmental effectiveness, compliance and side effects. The additionality that each agreement was likely to provide was also assessed. The results of this process suggest that in the majority of cases the CSS agreements should maintain or enhance the environment in terms of ecology, landscape, and landscape history and increase public enjoyment of the countryside. Thirty-six percent of agreements showed high additionality and 38% medium additionality which demonstrates that the CSS is likely to provide a benefit to society. Agreement negotiation, predicted environmental effectiveness and predicted compliance all improved significantly over the period 1996-98. Recommendations made from this project have been implemented by the Government department to improve the CSS. The multi-disciplinary method was successful and, with further development, could be used for assessment of any agri-environment scheme, or potentially any conservation project or broader 'rural development' scheme encompassing environmental, economic and social objectives. A key to success is the need for the criteria to be tailored for the project concerned and clearly established at the beginning.

Agriculture↗
PubMed2003

X-linked myotubular myopathy in a family with three adult survivors.

We describe a family with an extremely mild form of X-linked myotubular myopathy. Three affected males survived to adulthood with sufficient muscle strength to enable them to carry out normal daily activities. The mildness of the myopathy in this family is highlighted by the following: no neonatal or infant mortality resulting from the myopathy; one affected male who did not have neonatal asphyxia and had normal early motor milestones - this affected male was able to increase his muscle bulk and strength to normal by weightlifting; and a 55-year-old male who still lives an independent life. DNA sequencing identified a novel missense mutation - G469A (E157K) - in exon 7 of the MTM1 gene in this family. To our knowledge, this is the third X-linked myotubular myopathy family, with multiple adult survivors, to be reported in the literature.

Base Sequence↗
PubMed2003

The use of cell salvage during radical retropubic prostatectomy: does it influence cancer recurrence?

OBJECTIVE: To assess whether there is a difference in the biochemical recurrence rate in patients who had radical retropubic prostatectomy (RRP) with or without cell salvage transfusion. PATIENTS AND METHODS: The records of 769 consecutive patients undergoing RRP between 1992 and 1998 were retrospectively reviewed. Patients having adjuvant hormonal treatment, postoperative external beam radiotherapy, or a follow-up of < 1 year were excluded from the analysis. The remaining 408 patients were categorized into three groups: 87 who received cell-salvaged blood using a commercial cell saver; 264 receiving only autologous transfusion; and 57 with no transfusion. Disease recurrence was defined as a prostate-specific antigen (PSA) level of> 0.2 ng/mL. Bivariate and multivariate logistic regression analyses were used to assess and compare the risk of cancer recurrence in the three groups. Covariates used in the multivariate analyses included Gleason score, preoperative PSA level, seminal vesicle involvement and surgical margins. RESULTS: The mean (range) follow-up was 40.2 (12-104) months; there were no significant differences among the groups in initial PSA level and Gleason score. In the multivariate logistic regression analysis, the initial PSA, Gleason score, seminal vesicle involvement and surgical margins, but not transfusion group, were independent predictors of recurrence. CONCLUSION: Cell salvage during RRP does not influence the recurrence of prostate cancer. Cell salvage is a safe method of transfusion during RRP.

Analysis of Variance↗
PubMed2003

Malignant retroperitoneal and abdominal germ cell tumors: an intergroup study.

BACKGROUND/PURPOSE: This randomized study examined survival (S) and event-free survival (EFS) rates using high-or standard-dose cisplatin-based combination chemotherapy and surgical resection for this subset of germ cell tumors. METHODS: Twenty-six of 317 patients enrolled on the POG 9049/COG 8882 intergroup study for malignant germ cell tumors had abdomen or retroperitoneum as the primary site. Twenty-five of 26 were eligible for inclusion (n = 25). Patients had biopsy or resection at diagnosis and randomization to chemotherapy including etoposide, bleomycin, and either standard-dose (PEB) or high-dose cisplatin (HDPEB). In patients with initial biopsy, delayed resection was planned. RESULTS: Median age was 26 months. There were 14 girls and 11 boys. There were 3 stage I to II, 5 stage III, and 17 stage IV patients. Surgical management included primary resection in 5, resection after chemotherapy in 13, and biopsy or partial resection in 7 patients. Overall 6-year EFS rate was 82.8% +/- 10.9%, and 6-year survival rate was 87.6% +/- 9.3%. By group, 6-year survival rate was 90.0% +/- 11.6% for PEB and 85.7 +/- 14.5% for HDPEB. Deaths include one from sepsis, one from malignant tumor progression, and one from bulky disease caused by benign components despite response of the malignant elements to chemotherapy. CONCLUSIONS: Malignant germ cell tumors arising in the abdomen and retroperitoneum have an excellent prognosis despite advanced stage in most children. Aggressive resection need not be undertaken at diagnosis, but a concerted attempt at complete surgical removal after chemotherapy is important to distinguish viable tumor from necrotic tumor or benign elements that will not benefit from further chemotherapy.

Abdominal Neoplasms↗
PubMed2003

Central core disease: clinical, pathological, and genetic features.

Central core disease (CCD) is a dominantly inherited congenital myopathy allelic to malignant hyperthermia (MH) caused by mutations in the RYR1 gene on chromosome 19q13.1. Eleven individuals with RYR1 mutations are described. Four index cases showed features consistent with a congenital myopathy (hypotonia, delayed motor milestones, and skeletal abnormalities including congenital hip dislocation and scoliosis). All four cases and subsequently seven other family members were found to possess novel mutations in the RYR1 gene. The degree of disability varied from one clinically normal individual, to another who had never achieved independent ambulation (the only patient with a de novo mutation). Four cases showed a mild reduction in vital capacity, repeated nocturnal polysomnography showed hypoxaemia in one case. A variety of muscle biopsy features were found; central cores were absent in the youngest case, and the biopsy specimens from two others were more suggestive of mini-core myopathy. In all cases missense mutations in exons 101, 102, and 103 of the RYR1 gene on were found. Future laboratory diagnosis of suspected cases and family members will be less invasive and more accurate with DNA analysis. Clinicians, especially paediatricians and orthopaedic surgeons, should be aware of this disorder because of the potential risk of MH.

Adolescent↗
PubMed2003

Current targets: where are we going?

Clinical targets are relatively easy to set but can be extremely difficult to implement. It is important to have organisational targets, in addition to clinical targets. The National Service Framework (NSF) for coronary heart disease sets national standards, defines service models, and establishes performance indicators for clinicians to meet. The new National Health Service ethos, in which front line staff are being empowered to develop innovative services tailored to local needs, is helping health professionals in primary care to deliver better care and improved "patient pathways" as promised in the NSF. However, there is still a need for additional resources in order to build capacity and provide support to the health care staff who are delivering the service.

Coronary Disease↗