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Biomedical subjects

C Smith

Publications and source records attributed to C Smith.

At least 199 records · Page 11Linked to original sources
PubMed2000

Prevalence of complementary therapy use by women with breast cancer. A population-based survey.

The study measured the prevalence and costs of complementary therapy use by women diagnosed with breast cancer in the South Thames NHS region. A postal questionnaire was sent to a sample of 1023 women from the Thames Cancer Registry who had been diagnosed with breast cancer in the previous 7 years. Just over a fifth (22.4%) had consulted a complementary practitioner in the previous 12 months. Almost one third (31.5%) had done so since diagnosis. Almost pound17000 had been spent on visits in the previous year. The women using complementary medicine after diagnosis were slightly younger, more educated and more likely to have used complementary medicine before their diagnosis than non-complementary medicine users. In conclusion, significant numbers of women are visiting complementary therapists for health reasons following a breast cancer diagnosis. The out of pocket costs per user, with notable exceptions, are modest. Use of practitioners of complementary therapies following diagnosis is a significant and possibly growing phenomenon.

Adolescent↗
PubMed2000

Loss of E2F4 activity leads to abnormal development of multiple cellular lineages.

We have generated mice deficient in E2F4 activity, the major form of E2F in many cell types. Analysis of newborn pups deficient in E2F4 revealed abnormalities in hematopoietic lineage development as well as defects in the development of the gut epithelium. Specifically, we observed a deficiency of various mature hematopoietic cell types together with an increased number of immature cells in several lineages. This was associated with an increased frequency of apoptotic cells. We also found a substantial reduction in the thickness of the gut epithelium that normally gives rise to crypts as well as a reduction in the density of villi. These observations suggest a critical role for E2F4 activity in controlling the maturation of cells in a number of tissues.

Abnormalities, Multiple↗
PubMed2000

Incorporating data from dissertations in systematic reviews.

OBJECTIVES: To determine whether unpublished dissertations are an important source of trials for systematic reviews. METHODS: In a review of infant massage, we identified 17 dissertations. We recorded whether each dissertation was included in the review and, if so, whether it contributed data to any analyses. RESULTS: Thirteen dissertations were excluded, 11 because of poor reporting of methodology. Three dissertations were also published as journal papers. The data from the remaining dissertation were not included in any analysis. Reviewing data on the Cochrane Library, only one of 878 reviews included data from a dissertation that might have changed a review's conclusions. CONCLUSIONS: Searching for and retrieving unpublished dissertations involves considerable time and effort and appears to influence the conclusions of a review only rarely.

Academic Dissertations as Topic↗
PubMed2000

Observations on metal concentrations in three species of shark (Deania calcea, Centroscymnus crepidater, and Centroscymnus owstoni) from southeastern Australian waters.

Deep sea dog sharks (Deania calcea, Centroscymnus crepidater, and Centroscymnus owstonii) were captured from the waters off western Victoria, Australia, in April and May 1998. The elements As, Ca, Cd, Cu, Fe, Hg, K, Mg, Mn, Na, Sr, and Zn were detected in the muscle tissue. The concentrations of Al, Ba, Be, Cr, Mo, Ni, Pb, and V were below the detection limits of the instrumental techniques employed (ICP-ES and GF-AAS). However, significant concentration differences between species were detected for As, Cd, Hg, and Zn. C. owstoni contained the highest concentrations of each of these elements. The concentrations of Cu, Pb, and Zn in each species were below the maximum levels permitted in food by the Australian Food Standards Code. The maximum permitted concentrations of As and Hg were exceeded in all species, and weekly consumption of 400 g of any of these sharks would result in intake of more than the FAO's provisional tolerable weekly intake. Although C. crepidator and D. calcea have strong relationships between length and mercury concentration, C. owstoni does not. Placing C. crepidator and C. owstoni in the same genus, therefore, is worth re-examination as the mechanisms for controlling mercury in C. owstoni appear to differ from that used by both C. crepidator and D. calcea.

Animals↗
PubMed2000

Long-term survival following extra-neural metastasis from a pineoblastoma.

A young woman presented with a pineoblastoma treated initially with whole neuraxis radiotherapy. She had biopsy confirmed metastatic disease to the left lateral pelvis which was treated on 2 separate occasions, and biopsy confirmed metastatic disease to the subcutaneous tissues of the left thigh. She currently remains well 8 years after the primary diagnosis and 6 years after the first systemic relapse.

Acetabulum↗
PubMed2000

The effect of scaling and root planing on the clinical and microbiological parameters of periodontal diseases: 12-month results.

BACKGROUND/AIMS: Previously, we reported that SRP resulted in a decrease in mean pocket depth and attachment level and reduced prevalence and levels of Bacteroidesforsythus, Porphyromonas gingivalis, and Treponema denticola at 3 and 6 months post-SRP in 57 subjects with adult periodontitis. 32 of the 57 subjects were monitored at 9 and 12 months. Thus, the purpose of the present investigation was to evaluate the microbial and clinical effects of SRP in 32 (mean age 48+/-11) subjects over a 12-month period. METHOD: Clinical assessments of plaque, gingival redness, suppuration, bleeding on probing, pocket depth and attachment level were made prior to SRP and at 3, 6, 9, and 12 months post-therapy. Subgingival plaque samples were taken at each visit and analyzed using the checkerboard DNA-DNA hybridization technique for the presence and levels of 40 subgingival species. Each subject also received maintenance scaling at each of the subsequent monitoring visits. Differences in clinical parameters and prevalence and levels of bacterial species were analyzed pre- and post-therapy using the Wilcoxon signed ranks test. The Quade test for related samples was used for analysis of multiple visits. RESULTS: Mean pocket depth (mm+/-SEM) decreased from 3.2+/-0.3 at baseline to 2.9+/-0.3 at 12 months (p<0.01). Mean attachment level showed significant reduction at 6 months, but did not diminish further. Bleeding on probing and plaque were significantly reduced at 12 months (p<0.001, p<0.05, respectively). P. gingivalis, B. forsythus and T. denticola decreased in prevalence and levels up to the 6-month visit and remained at these lower levels at 9 and 12 months. Significant increases in levels and prevalence were noted at 12 months for Actinomyces naeslundii genospecies 2, Actinomyces odontolyticus, Fusobacterium nucleatum ss polymorphum, Streptococcus mitis, Capnocytophaga sp, and Veillonella parvula. CONCLUSIONS: The data suggest that the maintenance phase of therapy may be essential in consolidating clinical and microbiological improvements achieved as a result of initial therapy.

Actinomyces↗
PubMed2000

Microbiological parameters associated with IL-1 gene polymorphisms in periodontitis patients.

BACKGROUND, AIMS: Polymorphisms in the cluster of IL-1 genes have been significantly associated with the severity of adult periodontitis. The purpose of this study was to compare microbiological parameters in IL-1 genotype negative and positive adult subjects with a range of periodontitis severities. METHOD: The study included 108 subjects in good general health. Clinical parameters were recorded at 6 sites/tooth excluding 3rd molars and included: plaque accumulation, gingival erythema, bleeding on probing, suppuration, pocket depth and attachment level. Subgingival plaque samples were collected from the mesiobuccal surface of up to 28 teeth in each subject (mean 25.3) providing a total of 2736 samples. The levels of 40 subgingival taxa were determined in each sample using checkerboard DNA-DNA hybridization. Fingerstick blood samples were collected for IL-1A (+4845) and IL-1B (+3954) genotyping using PCR-based methods. RESULTS: The proportion of IL-1 genotype positive subjects that exhibited mean counts of specific subgingival species above selected thresholds was significantly higher than the proportion of genotype negative subjects. Prominent among species that were detected at higher levels in genotype positive subjects were members of the "red" and "orange" complexes and included: Bacteroides forsythus, Treponema denticola, the Fusobacterium nucleatum subspecies, Fusobacterium periodonticum, Campylobacter gracilis, Campylobacter showae and Streptococcus constellatus. Streptococcus intermedius, Streptococcus gordonii and 3 Capnocytophaga species were also detected more frequently at high numbers in genotype positive subjects. Significantly higher mean counts of B. forsythus, Porphyromonas gingivalis, T. denticola, the F. nucleatum subspecies, F. periodonticum, Campylobacter rectus, C. showae, Eubacterium nodatum, S. constellatus, S. gordonii, and S. intermedius were detected at periodontal pockets >6 mm in subjects who were genotype positive when compared with genotype negative subjects. The increase was due to increased numbers of cells of these species rather than a major shift in proportion. CONCLUSION: The data suggest that genotype positive subjects more frequently had higher levels of "red" and "orange" complex species that are known to be strongly associated with measures of periodontal inflammation.

Adult↗
PubMed2000

Bacteria of asymptomatic periradicular endodontic lesions identified by DNA-DNA hybridization.

Possible inclusion of contaminant bacteria during surgery has been problematic in studies of periradicular lesions of endodontic origin. Therefore, in this study, two different surgical techniques were compared. A second problem is that some difficult to cultivate species may not be detected using bacteriological methods. Molecular techniques may resolve this problem. DNA-DNA hybridization technology has the additional advantage that DNA is not amplified. The purpose of this investigation was to determine if bacteria from periradicular endodontic lesions could be identified using DNA-DNA hybridization. A full thickness intrasulcular mucoperiosteal (IS) flap (n = 20) or a submarginal (SM) flap (n = 16) was reflected in patients with asymptomatic apical periodontitis. DNA was extracted and incubated with 40 digoxigenin-labeled whole genomic probes. Bacterial DNA was detected in all 36 lesions. Seven probes were negative for all lesions. In patients with sinus tract communication, in teeth lacking intact full coverage crowns, and in patients with a history of trauma 4-13 probes provided positive signals. Seven probes were positive in lesions obtained by the IS, but not the SM technique. Two probes were in samples obtained with the SM technique, but not the IS. Only Bacteroides forsythus and Actinomyces naeslundii genospecies 2 were present in large numbers using either the IS or the SM technique. The SM flap technique, in combination with DNA-DNA hybridization, appeared to provide excellent data pertaining to periradicular bacteria. These results supported other studies that provide evidence of a bacterial presence and persistence in periradicular lesions.

Actinomyces↗
PubMed2000

Experience-dependent changes in cerebral activation during human REM sleep.

The function of rapid-eye-movement (REM) sleep is still unknown. One prevailing hypothesis suggests that REM sleep is important in processing memory traces. Here, using positron emission tomography (PET) and regional cerebral blood flow measurements, we show that waking experience influences regional brain activity during subsequent sleep. Several brain areas activated during the execution of a serial reaction time task during wakefulness were significantly more active during REM sleep in subjects previously trained on the task than in non-trained subjects. These results support the hypothesis that memory traces are processed during REM sleep in humans.

Adult↗
PubMed2000

An in vitro system for efficiently evaluating gene therapy approaches to hemoglobinopathies.

A variety of gene therapy strategies are under development for the treatment of sickle cell anemia and other hemoglobinopathies. A number of alternative vectors have been developed to transfer and express the beta-globin gene and other therapeutic molecules, but none has resulted in efficient transduction and stable long-term expression in primary hematopoietic cells. One reason for this problem is that most vectors are initially evaluated in immortalized cell lines which may not faithfully recapitulate the biology of primary erythroid cells. In order to provide a more relevant system for efficiently evaluating alternative vector constructs for beta-globin disorders, we have developed (1) a simple method for generating primary human red blood cell (RBC) precursors in liquid culture established with mononuclear cells obtained from normal donors as well as patients with Hb SC disease; (2) a high titer retroviral vector which can be easily modified to optimize gene transfer and transgene expression; and (3) methods for transducing the RBC precursors at high efficiency. The development of simple and efficient methods and reagents for generating and transducing primary human RBC precursors provides a facile and effective means for screening alternative gene therapy strategies. Gene Therapy (2000) 7, 215-223.

Anemia, Sickle Cell↗
PubMed2000

Assessment of hepatitis C virus RNA and genotype from 6807 patients with chronic hepatitis C in the United States.

Hepatitis C virus (HCV) RNA status and HCV genotype have become important tools in the diagnosis and monitoring of therapy in chronic HCV infection. To establish a database with respect to HCV genotype and serum HCV RNA concentrations in chronic hepatitis C patients in the United States, we analysed 6807 chronic hepatitis C patients who had HCV RNA and HCV genotype tests conducted at a central laboratory. The HCV RNA concentration cut-off for the lower 25th percentile of this population (low titre) was 0.9 x 106 copies ml-1. The median HCV RNA concentration was 3.5 x 106 copies ml-1 and the cut-off for the upper 25th percentile (high titre) was 5 x 106 copies ml-1. Male patients had a median HCV RNA concentration of 3.9 x 106 copies ml-1, which was significantly higher than the median HCV RNA level for females (2.75 x 106 copies ml-1; P < 0.001). HCV genotype 1 was detected in 73% of patients; genotype 2 in 14%; genotype 3 in 8%; mixed genotype in 4%; and genotypes 4, 5 and 6 with a frequency of < 1%. Patients from the Northeast, Southeast and Midwest had significantly (P < 0.001) more infections with genotype 1 than patients from the Western and Southern regions. African-American patients were more likely to be infected with genotype 1 when compared with Caucasian, Hispanic or Asian Pacific Islanders (P < 0.001). Patients infected with HCV genotype 1 and mixed HCV genotypes had significantly higher serum HCV RNA concentrations when compared with HCV genotypes 2 and 3 (P < 0.001 for all comparisons).

Black People↗
PubMed2000

Hypoglycaemia is a cause of axonal injury.

Axonal injury as demonstrated immunohistochemically is increasingly being recognized at post-mortem in patients who have been unconscious, and in some cases the cause of the coma may not be immediately apparent. Considerations include microscopical diffuse traumatic axonal injury and axonal injury associated with a range of metabolic encephalopathies. In this study, extensive neurohistological examination was undertaken in 13 patients in whom coma was attributed to hypoglycaemia and in whom neurohistological examination had revealed varying degrees of widely distributed neuronal necrosis: in five of these cases there was also evidence that the intracranial pressure had been high with internal hernation. It is concluded that a significant amount of axonal injury found in these 13 cases can be attributed to hypoglycaemia per se although the amount and distribution of the axonal damage is altered in the presence of raised intracranial pressure. However, in some cases axonal damage is seen in the absence of an elevated intracranial pressure and in one case its distribution closely mimicked that seen in microscopical diffuse traumatic axonal injury. This further demonstrates that not all axonal pathology is traumatic, and that adequate sampling and care in interpretation of Abeta-PP staining is required in forensic practice.

Adolescent↗
PubMed2000

Suicide risk assessment: a review of procedures.

Suicide risk assessment is an important part of the nurse's role. Suicide screening is an integral component of the assessment process. It should be systematic and follow a prescribed procedure: client self assessment, holistic assessment and diagnosis. The Gatehouse Assessment Centre in Warrington, UK, a predominantly nurse led centre, was opened in 1995, operates 365 days, 9 am till 9 pm, with open referral. The Centre offers psychiatric assessment, short-term treatments or referral on without hospital beds. In line with local and national policy, the Gatehouse team have introduced suicide rating scales as part of their risk screening process. However, the team have encountered problems using their designated scale, adapted from the Suicide Intent Scale, Pierce (1981). The major problem with the use of a rating scale was that, as a one off scoring system, it did not reflect the dynamic nature of suicidal behaviour. Furthermore, it is questionable whether a tool developed for research purposes would be used in the same way in practice. From a clinical perspective, the tool was capable of measurement only and failed to assist a dynamic holistic assessment required by practitioners. It was, therefore, necessary to review and evaluate the risk assessment procedure. In order to address these problems an assessment procedure which is more than a once only 'score' was piloted. The procedure incorporated risk screeners. Rather than rely on a value weighting system, or a positive or negative conclusion, it took account of the continuum of risk which is contingent on a broad range of factors. It took account of the accumulation of risk factors which may be increased or reduced in the light of unfolding events. Details of the new procedure, how it has been incorporated into the assessment process and subsequent management plan, and methodological considerations for further study are detailed.

Adult↗
PubMed2000

Influence of purine intake on uric acid excretion in infants fed soy infant formulas.

OBJECTIVE: These studies tested the hypothesis that increasing intake of purines, delivered as RNA from soy protein-based infant formula, would increase urinary uric acid excretion in infants. METHODS: Study One examined the influence of feeding on serum uric acid in a total of 178 infants from four separate trials with infants fed commercial and experimental soy-based and milk-based infant formulas or human milk. Studies Two and Three compared the effect of a standard purine soy formula (STD Purine; 180 mg purines/L from RNA) and a reduced purine soy formula (Reduced Purine; 65 mg purines/L; 26 mg/L from RNA and 39 mg/L from ribonucleotides) on urinary uric acid excretion in infants. In Study Two, 11 infants ranging in age from 16 to 128 days of age were fed both formulas in a random crossover design. Complete 72-hour urine collections were done at the end of each 11-day feeding period. Urinary uric acid excretion was expressed as mmol/day. In Study Three, 33 infants were enrolled before eight days of age and randomized to one of the formulas one week later. Spot urine samples were collected at 28 and/or 56 days of age and urinary uric acid concentration was expressed as mmol/mmol creatinine. RESULTS: In Study One, each of the feedings resulted in mean serum uric acid levels within normal reference ranges. Soy formula led to higher serum uric acid levels than human milk, and human milk to levels indistinguishable from cow milk-based formulas. In Study Two, infants excreted significantly more uric acid in the urine when fed the STD Purine formula compared to the Reduced Purine formula (0.86+/-.04 vs. 0.57+/-.04 mmol/d) (p = 0.006). In Study Three, infants fed the STD Purine formula had a significantly higher concentration of uric acid in their urine compared to those fed the Reduced Purine formula (2.1+/-0.2 vs. 1.4+/-0.1 mmol uric acid/mmol creatinine) (p = 0.0001). CONCLUSION: These data indicate that healthy infants can digest RNA and subsequently absorb the liberated purine ribonucleotides as determined by urinary uric acid concentration.

Cross-Over Studies↗
PubMed2000

Breast cancer, heterocyclic aromatic amines from meat and N-acetyltransferase 2 genotype.

Breast cancer risk has been hypothesized to increase with exposure to heterocyclic aromatic amines (HAAs) formed from cooking meat at high temperature. HAAs require enzymatic activation to bind to DNA and initiate carcinogenesis. N-acetyltransferase 2 (NAT2) enzyme activity may play a role, its rate determined by a polymorphic gene. We examined the effect of NAT2 genetic polymorphisms on breast cancer risk from exposure to meat by cooking method, doneness and estimated HAA [2-amino-1-methyl-6-phenylimidazole[4,5-b]pyridine (PhIP), 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline (MeIQx) and 2-amino-3,4,8-trimethylimidazo[4,5-f]quinoxaline (DiMeIQx)] intake. Women were recruited with suspicious breast masses and questionnaire data were collected prior to biopsy to blind subjects and interviewers to diagnoses. For 114 cases with breast cancer and 280 controls with benign breast disease, NAT2 genotype was determined using allele-specific PCR amplification to detect slow acetylator mutations. HAAs were estimated from interview data on meat type, cooking method and doneness, combined with a quantitative HAA database. Logistic regression models controlled for known risk factors, first including all controls, then 108 with no or low risk (normal breast or no hyperplasia) and finally 149 with high risk (hyperplasia, atypical hyperplasia, complex fibroadenomas). Meat effects were examined within NAT2 strata to assess interactions. We found no association between NAT2 and breast cancer. These Californian women ate more white than red meat (control median 46 versus 8 g/day). There were no significant associations of breast cancer with red meat for any doneness. White meat was significantly protective (>67 versus <26 g/day, OR 0.46, 95% CI 0.23-0.94, P for trend = 0.02), as was chicken, including well done, pan fried and barbecued chicken. MeIQx and DiMeIQx were not associated with breast cancer. A protective effect of PhIP was confounded after controlling for well done chicken. Results were unchanged using low or high risk controls or dropping 30 in situ cases. There was no interaction between NAT2 and HAAs. These findings do not support a role for HAAs from meat or NAT2 in the etiology of breast cancer. Further research is needed to explain the white meat association.

Adult↗
PubMed2000

Motor slowing and parkinsonian signs in aging rhesus monkeys mirror human aging.

Motor slowing is a universal feature of human aging, and parkinsonian signs are commonly expressed in human senescence. In the present study, age-associated declines in motor functions in 31 female rhesus monkeys were quantified by activity monitors and an automated test panel, and the incidence of parkinsonian signs was scored using a movement dysfunction assessment scale. Activity levels in middle-aged monkeys (12-17 years old) were less than half that of young animals (5-8 years old) and were further depressed in aged monkeys (21-27 years old). Movement dysfunction scores increased significantly with increasing age. Two or more parkinsonian signs were exhibited by 20% of the middle-aged monkeys and 36% of the aged monkeys. Slowing performance times on fine-motor hand tasks correlated significantly with increasing age. Motor learning was seen in all age groups, but improved faster in the young monkeys. The data suggest that aging rhesus monkeys provide an appropriate model to analyze the biological processes leading to motor slowing and the expression of parkinsonian signs in human senescence.

Aging↗