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Biomedical subjects

R R Taylor

Publications and source records attributed to R R Taylor.

At least 19 recordsLinked to original sources
PubMed2005

Developmental analysis and computer modelling of bioengineered teeth.

Here we present the developmental progression of bioengineered pig teeth from 1 to 25 weeks of development. We demonstrate that 2-25 week implants contained embryonic tooth bud- and cap-stage tooth structures consisting of dental epithelium expressing the sonic hedgehog gene and condensed dental mesenchyme. Implants harvested at 18-25 weeks also contained tooth bud-like structures, as well as mature tooth structures containing enamel, dentin and pulp tissues. Immunohistochemical analyses confirmed the expression of dentin- and enamel-specific proteins in differentiated bioengineered tooth tissues. Three-dimensional computer modelling further demonstrated a spatial organization of enamel, dentin and pulp tissues resembling that of natural teeth. We conclude that bioengineered teeth commonly exhibit morphological stages characteristic of naturally forming teeth. Furthermore, the presence of immature tooth buds at all times assayed and increased numbers of bioengineered tooth structures over time suggests that porcine dental progenitor cells maintain the ability to form teeth for at least 25 weeks.

Animals↗
PubMed2004

Efficacy of the latest fluoroquinolones against experimental Yersinia pestis.

The efficacies of prophylactic and therapeutic gatifloxacin and moxifloxacin were assessed in a BALB/c mouse model of systemic and pneumonic plague and compared with ciprofloxacin. Mice were given 100 mg/kg of the antibiotic by oral administration twice daily for 7 days starting 1h prior to infection or following infection. All antibiotics offered full protection for up to 6h following systemic challenge, and for up to 30 h following an aerosol challenge. The efficacy of each of the antibiotics decreased when antibiotics were started 18 h following systemic challenge and 48 h following aerosol challenge. Fluoroquinolones may therefore be considered useful candidates for the treatment of bubonic and pneumonic plague.

Animals↗
PubMed2002

Symptom occurrence in persons with chronic fatigue syndrome.

This investigation compared differences in the occurrence of symptoms in participants with CFS, melancholic depression, and no fatigue (controls). The following Fukuda et al. [Ann. Intern. Med. 121 (1994) 953] criteria symptoms differentiated the CFS group from controls, but did not differentiate the melancholic depression group from controls: headaches, lymph node pain, sore throat, joint pain, and muscle pain. In addition, participants with CFS uniquely differed from controls in the occurrence of muscle weakness at multiple sites as well as in the occurrence of various cardiopulmonary, neurological, and other symptoms not currently included in the current case definition. Implications of these findings are discussed.

Adult↗
PubMed2001

Equal care ensures equal survival for African-American women with cervical carcinoma.

BACKGROUND: [corrected] It was the purpose of this study to investigate whether race is an independent prognostic factor in the survival of patients with cervical carcinoma in a health care system with minimal racial bias, and few barriers to access to care. METHODS: Records for patients with a diagnosis of invasive cervical carcinoma from 1988 to 1999 were obtained from the Automated Central Tumor Registry for the United States Military Health Care System. Clinical data including race, age at diagnosis, histology, grade, stage, socioeconomic status, treatment modality, and survival also were obtained. Survival analysis was performed with Kaplan-Meier survival curves. RESULTS: One thousand five hundred fifty-three patients were obtained for review. Sixty-five percent of patients were Caucasian, and 35% were minorities. Of the minorities, 29% were African Americans (AAs). Mean age of diagnosis was similar among AAs and Caucasians, 44 and 42 years, respectively. There was no statistically significant difference between the distribution of age, stage, grade, or histology between Caucasians and AAs. Forty-six percent of patients were treated with surgery and 56% with radiation therapy, with no difference in type of treatment between the Caucasian and AA groups. Five- and 10-year survival rates for Caucasians and AAs were 75%, and 76%, and 64% 65% (P = 0.59), respectively. CONCLUSIONS: In an equal access, unbiased, nonracial environment, race is not an independent predictor of survival for patients with cervical carcinoma. This study has shown, for the first time to the authors' knowledge, that when they receive equal treatment for cervical carcinoma, AA women's survival can approach that of their nonminority counterparts (75% at 10 years).

Black or African American↗
PubMed2001

A community-based study of seasonal variation in the onset of chronic fatigue syndrome and idiopathic chronic fatigue.

One proposed hypothesis regarding the etiology of chronic fatigue syndrome (CFS) is that there is a subgroup of patients in which symptom onset is precipitated by a viral infection. If this is indeed true, then one would anticipate a greater incidence of the emergence of CFS symptoms during months when viral infections occur with the greatest frequency. The current community-based epidemiology study examined the month of symptom onset for 31 patients with CFS and 44 others with idiopathic chronic fatigue (ICF). It was determined that the distribution of the month of illness onset for the CFS and ICF groups was nonrandom, with greater numbers of participants than expected reporting an onset of CFS and ICF during January.

Adult↗
PubMed2001

Sexual abuse, physical abuse, chronic fatigue, and chronic fatigue syndrome: a community-based study.

Using a randomly selected community-based sample, this investigation examined whether histories of childhood sexual, physical, and death threat abuse predicted adulthood outcomes of specific medical and psychiatric conditions involving chronic fatigue. This study also tested prior suggestions that most individuals with chronic fatigue syndrome report a past history of interpersonal abuse. Multinomial logistic regression was used to examine the relationship between abuse history and chronic fatigue group outcomes while controlling for the effects of sociodemographics. Compared with healthy controls, childhood sexual abuse was significantly more likely to be associated with outcomes of idiopathic chronic fatigue, chronic fatigue explained by a psychiatric condition, and chronic fatigue explained by a medical condition. None of the abuse history types were significant predictors of chronic fatigue syndrome. A closer examination of individuals in the chronic fatigue syndrome group revealed that significantly fewer individuals with CFS reported abuse as compared with those who did not. The implications of these findings are discussed.

Adolescent↗
PubMed2001

Improved analysis of brachial artery ultrasound using a novel edge-detection software system.

Brachial artery ultrasound is commonly employed for noninvasive assessment of endothelial function. However, analysis is observer dependent and susceptible to errors. We describe studies on a computerized edge-detection and wall-tracking software program to allow more accurate and reproducible measurement. In study 1, three purpose-built Perspex phantom arteries, 3.00, 4.00, and 6.00 mm in diameter, were measured with the software. There was a mean bias of 11 microm (P < 0.001 at each level) between known and measured values; the mean resolving power of the software was estimated as 8.3 microm. In study 2, the mean intraobserver coefficient of variation of repeated measures of flow-mediated dilation (FMD) using the software (6.7%) was significantly lower than that for traditional manual measurements using the intima-lumen interfaces (24.8%, P < 0.05) and intima-media interfaces (32.5%, P < 0.05). In study 3, 24 healthy volunteers underwent repeat testing twice within 1 wk; the coefficients of variation for between-visit reproducibility of FMD and response to glyceryl trinitrate using the software were 14.7 and 17.6%, respectively. Assuming 80% power and an alpha of 0.05, eight subjects with matched controls would be required, in a parallel designed study, to detect an absolute 2.5% change in FMD. In summary, we have developed a semiautomated computerized vascular ultrasound analysis system that will improve the power of clinical intervention studies to detect small changes in arterial diameter.

Analysis of Variance↗
PubMed2001

Assessing attitudes toward new names for chronic fatigue syndrome.

A questionnaire was distributed at the American Association of Chronic Fatigue Syndrome's biannual convention in Washington in January 2001 as well as through various Internet Web sites and listserves during early February and March of 2001. The sample consisted of 432 respondents. Most respondents (86%) indicated they wanted a name change, although more patients than scientists were in favor of this change. It was also apparent that the patients and physicians were clearly split between adopting a name such as myalgic encephalopathy versus one such as neuro-endocrine immune disorder. Also, among those respondents who selected either of these two choices for a new name, less than 30% of them supported the other name. Although the majority of respondents feel the name should be changed at this time, this survey suggests there are different stakeholders involved in the name-change process, each with strong and sometimes disparate feelings about changing the name.

Fatigue Syndrome, Chronic↗
PubMed2001

Lack of evidence for association between endothelial nitric oxide synthase gene polymorphisms and coronary artery disease in the Australian Caucasian population.

BACKGROUND: Genetic polymorphism in the gene for endothelial nitric oxide synthase (eNOS) has been identified as a potential risk factor for the development of premature coronary artery disease (CAD). We determined whether the eNOS 4ab, G894T, and T-786C polymorphisms are associated with premature coronary artery disease. DESIGN: A case-control study. METHODS: PCR-based assays were used to compare the frequency of eNOS gene polymorphisms in 573 Caucasian subjects aged under 50 years presenting with symptomatic CAD and documented by coronary angiography, with or without myocardial infarction, to that of 624 similarly aged community controls without a history of symptomatic CAD. RESULTS: We found no difference in the frequency of 4ab genotypes between cases and controls: in the CAD subjects, the 4aa, 4ab, and 4bb genotype frequencies were 1.9%, 24.3% and 73.8% respectively, compared to 2.2%, 25.5% and 72.3% respectively for the controls. There was also no significant difference between cases and controls in the frequency of any allele (4a/4b, 894G/894T, -786C/-786T), or genotype for any of the polymorphisms. Similarly, logistic regression analysis showed no evidence for an association of the polymorphisms with premature CAD or myocardial infarction or any indication of an interaction between the polymorphisms and other CAD risk factors, including smoking. CONCLUSIONS: In a large case-control study, and in contrast to some earlier positive findings by others, we have found no evidence for an association between several eNOS gene polymorphisms and premature CAD in an Australian Caucasian population.

Adult↗
PubMed2000

Chronic fatigue syndrome: an examination of the phases.

The present study examined the Fennell Phase Inventory, an instrument designed to measure the phases typically experienced by individuals with chronic fatigue syndrome (CFS). This inventory yields three factor scores of Crisis, Stabilization, and Integration. These factor scores have been employed in a cluster analysis, yielding four clusters that matched the four phases predicted by Fennell: Crisis, Stabilization, Resolution, and Integration. The present study represents a partial replication study of a prior investigation of the Fennell Phase Inventory by Jason et al. (in press), but that earlier study did not have an independent physician examination to diagnose patients with CFS. In the present study, 65 patients diagnosed with chronic fatigue syndrome by a physician were recruited and administered the Fennell Phase Inventory and other measures assessing CFS-related symptoms, disability, and coping. Each of the 65 patients was classified into one of four predefined clusters measuring a Crisis phase, a Stabilization phase, a Resolution phase, and an Integration phase. Relationships were explored between three of these cluster groupings and measures of symptoms, disability, and coping. Results confirmed Fennell's model, revealing significant differences between the three clusters in terms of levels of disability and modes of coping. Results suggest that the Fennell Phase Inventory accurately differentiates phases of adaptation to illness experienced by individuals with CFS.

Adaptation, Psychological↗
PubMed2000

p27 and cyclin D1 abnormalities in uterine papillary serous carcinoma.

OBJECTIVE: The expression status of p27 and cyclin D1 was examined in 21 uterine papillary serous carcinoma (UPSC) specimens to determine the role of these genes in the development of this disease. The status of p53, p16, Rb, and K-ras was also determined in these tissues so that a marker profile for UPSC could be compared with the published marker profile for other forms of endometrial and ovarian cancer. METHODS: Immunohistochemistry was performed on 21 UPSC tissue sections to determine the expression status of p27, cyclin D1, p53, p16, and Rb. K-ras mutations were identified by restriction fragment length polymorphism analysis of DNA isolated from the UPSC sections. RESULTS: All specimens displayed at least one molecular abnormality. A high incidence of p27 alterations were observed, with reduced p27 expression measured in 16 of 21 (76%) tumors, followed by p53 alterations observed in 13 of 21 (62%) tumors. The p27 abnormalities occur at an early stage of the disease, with 63% (5/8) of Stage I cases displaying reduced p27 expression. Cyclin D1 overexpression was observed in 4 of 21 (19%) specimens, whereas p16, Rb, and K-ras abnormalities were each observed in 2 of 21 specimens (10%). Both K-ras mutations were at codon 12. The p16 and Rb abnormalities coexisted in the same specimens. CONCLUSION: UPSC tumors display a high incidence of p27 abnormalities, suggesting that p27 abnormalities play an important role in the development of this disease. Our results also indicate that cyclin D1 overexpression is involved in the development of a small number of UPSC cases. A comparison of our results with reports by other authors suggests that UPSC shares molecular marker alterations with both ovarian cancer and endometrioid adenocarcinoma.

Adult↗
PubMed2000

Age-specific survival of women with endometrioid adenocarcinoma of the uterus.

OBJECTIVE: The purpose of this paper was to evaluate the age-specific survival for women diagnosed with endometrioid adenocarcinoma of the uterus. METHODS: A retrospective analysis was conducted of 328 patients diagnosed with endometrioid adenocarcinoma of the uterus between January 1990 and December 1997. Patients were followed for 3 to 96 months with a mean of 43 months. The impact of age on survival was assessed using Cox proportional hazard regression and multivariate analysis for age, stage, and grade. Stage and grade were analyzed using log-rank tests, and survival curves were generated by the Kaplan-Meier method. RESULTS: A total of 328 patients were evaluated. Multivariate analysis revealed age, stage, and grade were all significant independent predictors of survival (P < 0.0001). Age-specific survival varied from a high of 90% at age 40 to a low of 55% at age 80. Interval age-specific survival decreased below 86% at age 50. Subset analysis of patients younger than 50 compared with older patients revealed no difference in surgical stage or grade of tumors among these patients. Patients older than 50, however, were 41% more likely to receive adjuvant radiation therapy. CONCLUSION: Age is a specific, significant predictor of outcome in endometrioid adenocarcinoma of the uterus. Survival decreases significantly in patients older than 50. This decreased survival associated with age is unrelated to surgical stage or grade of adenocarcinoma. Decreased survival could involve molecular differences in the developing endometrial cancer or an increased risk of death from other non-cancer-related factors.

Adult↗
PubMed2000

Fatigue rating scales: an empirical comparison.

BACKGROUND: There has been limited research comparing the efficacy of different fatigue rating scales for use with individuals with chronic fatigue syndrome (CFS). This investigation explored relationships between two commonly-used fatigue rating scales in CFS research, the Fatigue Scale and the Fatigue Severity Scale. Theoretically, these scales have been described as measuring different aspects of the fatigue construct. The Fatigue Scale was developed as a measure of the severity of specific fatigue-related symptoms, while the Fatigue Severity Scale was designed to assess functional outcomes related to fatigue. METHODS: Associations of these scales with the eight definitional symptoms of CFS and with eight domains of functional disability were examined separately in: (1) an overall sample of individuals with a wide range of fatigue severity and symptomatology; (2) a subsample of individuals with CFS-like symptomatology, and, (3) a subsample of healthy controls. RESULTS: Findings revealed that both scales are appropriate and useful measures of fatigue-related symptomatology and disability within a general population of individuals with varying levels of fatigue. However, the Fatigue Severity Scale appears to represent a more accurate and comprehensive measure of fatigue-related severity, symptomatology, and functional disability for individuals with CFS-like symptomatology.

Adolescent↗
PubMed2000

Angiotensin-converting enzyme gene polymorphism and premature coronary heart disease.

Since the initial report of the association of the deletion/insertion (D/I) polymorphism in the gene for angiotensin-converting enzyme (ACE) with myocardial infarction (MI), there has been considerable controversy. Some have found the D allele to be associated with MI, coronary heart disease (CHD) or other cardiac pathology, while others have not. In the present study 713 consecutive patients, < 50 years of age, documented prospectively with angiographic CHD (> 50% diameter stenosis of at least one coronary artery), with or without MI, were studied, along with 688 community control subjects, also < 50 years of age, selected randomly from the electoral rolls and without a history of CHD or MI. Genotyping was done by standard methods. Most of the subjects in both groups were Anglo-Celtic Caucasians (547 in the CHD group and 642 in the community group), and the report concerns primarily these subjects. ACE genotype distributions were not different between the Caucasian community control group and the CHD or the MI subgroups; the odds ratios and 95% confidence limits for the CHD group were 0.96 (0.73-1.27) for the D allele and 1.02 (0.80-1.31) for D homozygotes; for the MI group these values were 1.00 (0.83-1.20) and 0.99 (0.74-1.32) respectively. This negative result was supported in multivariate analysis accounting for conventional risk factors. There was a significant racial difference in ACE genotypes between Caucasians, Asians and Australian Aborigines in the CHD group (P < 0.001); for example, in this group, 158 of 540 (29%) Caucasians had the DD genotype compared with eight of 84 (10%) Aboriginals (P < 0.001) and six of 59 (10%) Asians (P = 0.002). Failure to account for such racial differences would have led to erroneous conclusions. In conclusion, we found no evidence that the D/I ACE gene polymorphism plays a role in the development of CHD or MI at an early age in a Western Australian Caucasian population. While this result refers uniquely to premature CHD and MI, and could be population specific, it is in general agreement with recent meta-analysis of the larger previous studies.

Adult↗
PubMed2000

Chronic fatigue syndrome: occupation, medical utilization, and subtypes in a community-based sample.

Most studies of chronic fatigue syndrome (CFS) have been based on patients recruited from primary or tertiary care settings. Patients from such settings might not be typical of patients in the general population. The present investigation involved examining individuals with CFS from a community-based study. A random sample of 18,675 respondents in Chicago was first interviewed by telephone. A group of individuals with chronic fatigue accompanied by at least four minor symptoms associated with CFS were given medical and psychiatric examinations. From this sample, a physician review group diagnosed individuals with CFS. Those diagnosed with CFS were subclassified based on a variety of categories, including duration of illness, mode of illness onset, and presence or absence of a stressful life event directly preceding onset. In addition, we examined medical utilization among those diagnosed with CFS, as well as whether individuals with CFS were disproportionately represented in health care professions. Important differences emerged on measures of sociodemographics, symptoms, and functional disability. The implications of these findings and others are discussed.

Adult↗
PubMed2000

Chronic fatigue syndrome: sociodemographic subtypes in a community-based sample.

Most chronic fatigue syndrome (CFS) studies are based on information about patients from primary or tertiary care settings. These patients might not be typical of patients in the general population. This investigation involved examinations of individuals with CFS from a community-based study. A random sample of 18,675 in Chicago was interviewed by telephone. Individuals with chronic fatigue and at least four minor symptoms associated with CFS were given medical and psychiatric examinations. A group of physicians then diagnosed individuals with CFS, who were then subclassified based on three sociodemographic categories--gender, ethnicity, and work status. Sociodemographic subgroups were analyzed in terms of symptom severity, functional disability, coping, optimism, perceived stress, and psychiatric comorbidity. Women, minorities, and nonworking individuals with CFS reported greater levels of functional disability, symptom severity, and poorer psychosocial functioning than men, Caucasians, and working individuals, suggesting sociodemographic characteristics may be associated with poorer outcomes in urban, community-based samples of CFS individuals.

Adolescent↗