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Biomedical subjects

K Hammond

Publications and source records attributed to K Hammond.

At least 19 recordsLinked to original sources
PubMed2006

Genetic diversity analysis using lowly polymorphic dominant markers: the example of AFLP in pigs.

DNA markers are commonly used for large-scale evaluation of genetic diversity in farm animals, as a component of the management of animal genetic resources. AFLP markers are useful for such studies as they can be generated relatively simply; however, challenges in analysis arise from their dominant scoring and the low level of polymorphism of some markers. This paper describes the results obtained with a set of AFLP markers in a study of 59 pig breeds. AFLP fingerprints were generated using four primer combinations (PC), yielding a total of 148 marker loci, and average harmonic mean of breed sample size was 37.3. The average proportion of monomorphic populations was 63% (range across loci: 3%-98%). The moment-based method of Hill and Weir (2004, Mol Ecol 13:895-908) was applied to estimate gene frequencies, gene diversity (F(ST)), and Reynolds genetic distances. A highly significant average F(ST) of 0.11 was estimated, together with highly significant PC effects on gene diversity. The variance of F(ST) across loci also significantly exceeded the variance expected under the hypothesis of AFLP neutrality, strongly suggesting the sensitivity of AFLP to selection or other forces. Moment estimates were compared to estimates derived from the square root estimation of gene frequency, as currently applied for dominant markers, and the biases incurred in the latter method were evaluated. The paper discusses the hypotheses underlying the moment estimations and various issues relating to the biallelic, dominant, and lowly polymorphic nature of this set of AFLP markers and to their use as compared to microsatellites for measuring genetic diversity.

Animals↗
PubMed2006

Genetic diversity within and between European pig breeds using microsatellite markers.

An important prerequisite for a conservation programme is a comprehensive description of genetic diversity. The aim of this study was to use anonymous genetic markers to assess the between- and the within-population components of genetic diversity for European pig breeds at the scale of the whole continent using microsatellites. Fifty-eight European pig breeds and lines were analysed including local breeds, national varieties of international breeds and commercial lines. A sample of the Chinese Meishan breed was also included. Eleven additional breeds from a previous project were added for some analyses. Approximately 50 individuals per breed were genotyped for a maximum of 50 microsatellite loci. Substantial within-breed variability was observed, with the average expected heterozygosity and observed number of alleles per locus being 0.56 [range 0.43-0.68] and 4.5 respectively. Genotypic frequencies departed from Hardy-Weinberg expectations (P < 0.01) in 15 European populations, with an excess of homozygotes in 12 of them. The European breeds were on average genetically very distinct, with a Wright F(ST) index value of 0.21. The Neighbour-Joining tree drawn from the Reynolds distances among the breeds showed that the national varieties of major breeds and the commercial lines were mostly clustered around their breeds of reference (Duroc, Hampshire, Landrace, Large White and Piétrain). In contrast, local breeds, with the exception of the Iberian breeds, exhibited a star-like topology. The results are discussed in the light of various forces, which may have driven the recent evolution of European pig breeds. This study has consequences for the interpretation of biodiversity results and will be of importance for future conservation programmes.

Alleles↗
PubMed2006

Genetic diversity in European pigs utilizing amplified fragment length polymorphism markers.

The use of DNA markers to evaluate genetic diversity is an important component of the management of animal genetic resources. The Food and Agriculture Organisation of the United Nations (FAO) has published a list of recommended microsatellite markers for such studies; however, other markers are potential alternatives. This paper describes results obtained with a set of amplified fragment length polymorphism (AFLP) markers as part of a genetic diversity study of European pig breeds that also utilized microsatellite markers. Data from 148 AFLP markers genotyped across samples from 58 European and one Chinese breed were analysed. The results were compared with previous analyses of data from 50 microsatellite markers genotyped on the same animals. The AFLP markers had an average within-breed heterozygosity of 0.124 but there was wide variation, with individual markers being monomorphic in 3-98% of the populations. The biallelic and dominant nature of AFLP markers creates a challenge for their use in genetic diversity studies as each individual marker contains limited information and AFLPs only provide indirect estimates of the allelic frequencies that are needed to estimate genetic distances. Nonetheless, AFLP marker-based characterization of genetic distances was consistent with expectations based on breed and regional distributions and produced a similar pattern to that obtained with microsatellites. Thus, data from AFLP markers can be combined with microsatellite data for measuring genetic diversity.

Alleles↗
PubMed2006

China at the crossroads: the economics of tobacco and health.

OBJECTIVE: To analyse economic aspects of tobacco control policy issues in China. METHODS: Published and collected survey data were used to analyse economic consequences of smoking. Economic analysis was used to address the role of tobacco farmers and the cigarette industry in the Chinese economy. RESULTS: In the agricultural sector, tobacco has the lowest economic rate of return of all cash crops. At the same time, the tobacco industry's tax contribution to the central government has been declining. CONCLUSION: Economic gains become less important as the negative health impact of smoking on the population garners more awareness. China stands at a crossroads to implement the economic promises of the World Health Organization's Framework Convention on Tobacco Control and promote the health of its population.

China↗
PubMed2003

Beauty is as beauty does: body image and self-esteem of pageant contestants.

Self-esteem, dieting, and body image of 131 female beauty pageant contestants (mean age 26.0 years) from 43 states were examined by an anonymous survey. Most (89.6%) reported being a pageant finalist or winner and 55.2% had competed at the nationa/international level Over one-fourth (26%) of the women had been told or perceived they had an eating disorder which reportedly began at 16.25 years. Almost half (48.5%) reported wanting to be thinner and 57% were trying to lose weight. Higher self-esteem scores were significantly associated with increased level of competition (i.e.: from local to international pageants), but not with the number of times the women were pageant finalists or winners. Future study is warranted to determine how pageant participation influences self-esteem, body image, and the development of eating disorders.

Adolescent↗
PubMed2001

Cizolirtine citrate (E-4018) in the treatment of chronic neuropathic pain.

This study was performed to determine the efficacy and safety of oral cizolirtine citrate, a novel agent, in the treatment of chronic neuropathic pain. Cizolirtine was tested in a double-blind, placebo-controlled, two-way crossover study, having previously been shown to have significant analgesic and anti-hyperalgesic action in neuropathic pain models and preliminary human studies. Twenty-five patients with neuropathic pain, which was persistent for at least three months, and scored > 30 mm on a 100 mm visual analogue scale (VAS), were included. A subgroup of five patients had primary skin allodynia, i.e. pain evoked by non-noxious stimuli in the territory of the injured nerve. Cizolirtine 200 mg or placebo was administered twice daily for a treatment period of 21 days, each separated by a washout interval of 7 days. Assessments of skin allodynia were performed using the graded monofilaments (von Frey hairs) on days 1 (predose), 14 and 21 (90 min postdose). All patients were instructed to maintain a daily pain diary throughout the study. Results showed that the differences in VAS and allodynia scores between cizolirtine and placebo treatments were not significant in the overall analysis (p > or = 0.05); cizolirtine was well tolerated. In a subgroup of five patients with primary allodynia, a 53% reduction in VAS score from baseline at rest (p = 0.007) and 55% on movement (p = 0.0002) at day 21 was observed with cizolirtine, as compared to 8% at rest (p = 0.5215) and 13% on movement (p = 0.4187) with placebo. Similarly, allodynia improved with cizolirtine (p = 0.03) but not with placebo (p = 0.9) in this subgroup. Cizolirtine may be effective in primary allodynia after peripheral nerve injury, and a further trial in a larger number of such subjects is warranted.

Adult↗
PubMed2000

Estimation of incidence of respiratory syncytial virus infection in schoolchildren using salivary antibodies.

An assay for respiratory syncytial virus (RSV)-specific IgG in saliva is described. The assay was used to examine the incidence of RSV infection in schoolchildren 7-10 years old during one RSV season. One hundred and twenty-one volunteer children provided saliva samples in October 1997 and March 1998; 18% of the children showed a fourfold or greater rise in anti-RSV IgG in the second sample. This prevalence of antibody increase is similar to that described in previous studies that measured CFT levels in serum samples. Overall, the children who showed rises in antibody levels, indicating that they had experienced an RSV infection, had lower levels of RSV-specific antibody in their preseason samples than those who showed no increase (P = 0.0018). These results show that saliva is an adequate substitute for serum in some antibody tests and may be useful for community studies. Such studies may provide surrogate markers for susceptibility to infection, which should benefit the planning of vaccination strategies.

Antibodies, Viral↗
PubMed2000

The influence of lysis buffer composition on the expression and activity of protein tyrosine phosphatase.

Lysis conditions are crucial in the extraction and solubilization of phosphotyrosine-containing proteins in a form that is immunoreactive, undegraded and enzymatically active. To establish optimal experimental conditions, we evaluated protein tyrosine phosphatase enzyme activity and the detection of PTP-1 B protein in human acute promyelocytic leukaemic cells, both before and after retinoic acid treatment. We found that the composition of the lysing buffer greatly influenced the efficiency of solubilization, resulting in major alterations in the activity of protein tyrosine phosphatases and on the mobility of PTP-1 B protein.

Buffers↗
PubMed2000

Modulation of the rhythmic patterns of expression of phosphoprotein phosphatases in human leukaemia cells.

Temporal variations in the expression of phosphoprotein phosphatase 1 (PP1), phosphoprotein phosphatase 2A (PP2A) and protein tyrosine phosphatase 1B (PTP1B) were monitored in the human acute, promyelocytic leukaemia cell line, HL60. Granulocytic differentiation was induced using all-trans retinoic acid (ATRA) and monocytic differentiation by phorbol-12-myristate-13-acetate (PMA). Expression of the enzyme proteins in cell extracts was determined by SDS-PAGE and Western immunoblotting using specific antibodies. For PP1, a single immunospecific band of molecular mass 38 kDa was detected corresponding to the catalytic subunit; induction of differentiation with either ATRA or PMA showed differences in the patterns of expression and, in the case of the latter, the mean value. Two immunospecific bands, of mass 34 and 37 kDa, possibly corresponding to dephosphorylated and phosphorylated forms, respectively, were detected for PP2A, as well as a minor band of mass 46 kDa; dynamic variations in the expression of all 3 forms were observed and there were differences between the control and treated cells. The catalytic domain of PTP1B was detected as a 46 kDa band. A 42 kDa form of the protein was also seen, which may represent a change in phosphorylation state, or be the result of proteolytic cleavage; usually the 46 kDa band was the major form, but on occasion there was a change to predominance of the 42 kDa band.

Blotting, Western↗
PubMed1999

Use of telemonitoring to decrease the rate of hospitalization in patients with severe congestive heart failure.

We investigated whether the application of a home-based telemonitoring system could decrease hospital admissions and emergency room visits in 30 patients with severe congestive heart failure compared with 51 patients with congestive heart failure who received standard therapy. Emergency room visits (1 vs 11) and hospitalizations (13 vs 36) were decreased in the telemonitored group (both p <0.05).

Analysis of Variance↗
PubMed1999

Prostate-specific antigen in vaginal fluid as a biologic marker of condom failure.

Forty women participated in three clinic visits during which they were exposed to their partner's semen (10 microL, 100 microL, and 1 mL). At each visit they took vaginal fluid samples before exposure to their partner's semen, immediately after, and at 1, 24, and 48 h after exposure. PSA was measured with an enzyme-linked immunoassay. The mean PSA level for preexposure swabs ranged between 0.43 and 0.88 ng/mL. The mean PSA levels were 193 immediately after exposure to 10 microL, 472 after 100 microL, and 19,098 after 1 mL. The PSA levels declined within 1 h, and returned to background at 48 h. The findings confirm that our procedure is a sensitive and specific method for detecting recent semen exposure, and indicate that PSA levels depend on exposure intensity and time since exposure. Application of this method in condom efficacy studies provides objective evidence of condom failure that enhances the interpretation of self-report.

Adult↗
PubMed1999

Nutrition-focused physical assessment.

Although it may seem that the nutrition-focused physical examination adds more time to the visit, the exam can be done in less time than a complete physical assessment. With practice, it can be built into your routine visit without adding significant additional visit time. The benefit of this type of examination will more than pay off in determining a baseline assessment that will allow a comprehensive plan of care to be developed. In the long-term, initial and continual assessment of a patient's nutritional status and progression toward appropriate outcomes will actually help your patient and you save you time and money and will result in less complications and better outcomes.

Community Health Services↗
PubMed1999

Nurse, physician, and consumer role responsibility perceived by health care providers.

The article describes a study that addressed perceptions of unilateral and egalitarian role functions for nurses, physicians, and consumers in a long-term, 345-bed psychiatric facility in the western United States. Findings indicated that physicians desired to retain authority for health care decisions and that nurses, social workers, and hospital administrators preferred collaborative practice. Support for shared responsibility increased among psychiatric technicians with years of experience. Experience did not alter the attitudes of physicians, occupational therapists, and recreational therapists for physician dominance. With experience, nurses increased their belief in nurse responsibility. Despite evidence for collaborative decision making, results of this study indicate that attitudes of health care providers may prevent this tenet from being actualized.

Attitude of Health Personnel↗
PubMed1999

Sensitivity and exposure to indoor allergens in adults with differing asthma severity.

In asthma, it is uncertain whether there is an association between degrees of exposure to domestic allergens and asthma severity. The pattern of sensitivity and exposure to common indoor allergens was examined in subjects with differing asthma severity. Sensitivity to house dust mite, dog and cat allergen and exposure to Der p 1, Can f 1 and Fel d 1 were assessed by skin prick tests and settled dust analysis in 28 subjects with severe asthma and 28 age- and sex-matched subjects with mild asthma (two declined skin prick test). All severe asthmatic subjects had at least one positive skin test and 20 of the 28 subjects were positive to all three allergens. Fourteen of the 26 subjects with mild asthma who took skin prick tests were positive to at least one, and one of these subjects was positive to the three allergens tested. Except for bedroom Fel d 1, the proportion of severe asthmatics both sensitized and exposed to each allergen at each site was significantly greater than the proportion sensitized and exposed in the mild asthma group. The geometric mean allergen concentrations, with the exception of bedroom Fel d 1, were greater in sensitized severe asthmatics than the sensitized mild asthmatics, which was significant for Der p 1 in bedroom samples and Can f 1 in bedroom and living room samples. These results support an association between the degrees of domestic allergen exposure in sensitized individuals and asthma severity.

Adult↗
PubMed1998

Three day neonatal thymectomy selectively depletes NK1.1+ T cells.

Neonatal thymectomy of mice 3 days after birth but not at birth leads to T cell-mediated, organ-specific, autoimmune disease in a strain-dependent manner. The mechanisms that lead to disease in this model remain unknown, but the answer may lie in a deficiency of thymus-dependent cells or factors. One candidate is the relatively rare population of NK1.1 + T cells (NKT cells). Conventional alphabetaTCR+ T cells appear in the thymus from days 17-18 of embryogenesis and start emigrating to the periphery around birth, whereas the development of NKT cells is thought to be delayed until at least 1 week after birth. We have confirmed this to be the case in both (BALB/c x C57BL/6)F1 (autoimmune susceptible) and C57BL/6 (autoimmune resistant) mice. Moreover, examination of T cells (in spleen, lymph nodes, liver and bone marrow) from mice following 3 day neonatal thymectomy revealed a significant reduction in the presence of NKT cells in all tissues. However, the extent of depletion was generally more pronounced in (BALB/c x C57BL/6)F1 than in C57BL/6 mice, and the few remaining NKT cells in C57BL/6 mice were enriched for a CD4-CD8int subset which is absent from the thymus and may represent a distinct lineage of thymus-independent NKT cells. Given mounting evidence of a role for NKT cells in protection from autoimmune disease, it is possible that their specific removal by neonatal thymectomy may contribute to the susceptibility of these mice to autoimmune disease.

Animals↗
PubMed1998

Post-infection fatigue syndrome following Q fever.

In 1989, 147 individuals in the West Midlands, UK, were infected with Q fever. Five years later, following anecdotal reports of fatigue, we used a questionnaire-based case-control study to determine the prevalence of chronic fatigue syndrome symptoms in this group. Replies from 71 patients were compared with those from 142 age- and sex-matched controls. Increased sweating (52.9% vs. 31.6%, p = 0.006), breathlessness (50.7% vs. 30.6%, p = 0.006), blurred vision (34.3% vs. 17.8%, p = 0.016) and undue tiredness (68.7% vs. 51.5%, p = 0.03) were found in controls compared to cases. These findings were similar to those in Australian abbatoir workers occupationally exposed to Q fever. CDC criteria for chronic fatigue syndrome were fulfilled by 42.3% of cases and 26% of controls. Using visual analogue scores, symptoms were more severe in cases than in controls. Our findings support the existence of a chronic fatigue state following acute Q fever, in a group of patients exposed just once to the organism, and in circumstances free of such confounding factors as lawsuits over compensation.

Acute Disease↗