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Biomedical subjects

T Hudson

Publications and source records attributed to T Hudson.

At least 19 recordsLinked to original sources

Point mutations in the pfcrt and pfmdr-1 genes of Plasmodium falciparum and clinical response to chloroquine, among malaria patients from Nigeria.

Chloroquine (CQ) resistance in Plasmodium falciparum has been associated with specific point mutations in the pfcrt and pfmdr-1 genes. In the present study, 30 children aged 1-12 years, who were all suffering from acute, uncomplicated, P. falciparum malaria in Ibadan, Nigeria, were evaluated to assess the association between these mutations and clinical outcome following treatment with CQ. The parasites, in blood samples collected pre-treatment and, in those who failed treatment, on the day symptoms re-occurred post-treatment, were genotyped using the polymorphic MSP1, MSP2 and GLURP loci and PCR-RFLP. The results showed that, pre-treatment, all 30 patients had polyclonal infections, the mean numbers of P. falciparum clones detected per infection being 2.6 with MSP1, 4.2 with MSP2 and 2.8 with GLURP. The T76 allele of pfcrt and the Y86 allele of pfmdr-1 were found in 53% and 40%, respectively, of the pre-treatment samples from the 15 patients who failed CQ treatment, but the Y1246 mutation in pfmdr-1 was never detected. Although the parasites from the two patients with high-grade (RIII) resistance to CQ had both of these point mutations, the presence of the T76 allele of pfcrt or the Y86 allele of pfmdr-1 (considered individually) could not be used to predict treatment outcome. However, a high frequency of clonal multiplicity may confound attempts to associate the point mutations in pfcrt or pfmdr-1 with clinical response to CQ. It remains unclear whether the present results represent the characteristics of the predominant parasite populations in the study area. Further studies are needed before the strength of the association between the point mutations identified as markers of drug resistance and clinical outcome can be accurately evaluated, in this and other regions of intense transmission.

ATP-Binding Cassette Transporters↗

Novel promoter polymorphism in insulin-like growth factor-binding protein-3: correlation with serum levels and interaction with known regulators.

Insulin-like growth factor (IGF)-binding protein-3 (IGFBP-3) is a major determinant of circulating levels of the IGFs and is clinically useful for the evaluation of GH deficiency and for predicting the response to GH treatment. Recent studies provide evidence that the circulating level of IGFBP-3 is inversely related to the risk of several common cancers, and that antiproliferative agents such as antiestrogens and retinoids act in part by up-regulating IGFBP-3 gene (IGFBP3) expression. Although approximately 50% of the substantial interindividual variability in circulating IGFBP-3 levels is known to have a genetic basis, the specific loci involved are unknown. Direct sequencing of genomic DNA specimens from a multiethnic population identified several single nucleotide polymorphisms in the promoter region of IGFBP3. For the most common single nucleotide polymorphism (nucleotide -202) found to be in Hardy-Weinberg equilibrium, genotype was highly correlated to circulating level of IGFBP-3 in 478 men from the Physicians' Health Study. In vitro, we documented significantly higher promoter activity of the A allele at the -202 locus compared with the C allele, consistent with the relationship observed between genotype and circulating IGFBP-3 (AA > AC > CC). A positive correlation was observed between circulating retinol levels and circulating IGFBP-3 levels; subset analysis by genotype showed that this relationship was only present among individuals carrying an A allele at -202 (AA > AC > CC). Tall individuals or individuals with a body mass index of 27 or greater had levels of circulating IGFBP-3 that were significantly higher when they possessed at least one A allele (AA > AC > CC). The IGFBP3 promoter region deserves investigation as a locus where polymorphic variation occurs frequently and may influence GH responsiveness, somatic growth, and possibly cancer risk.

Aging↗

Genetic and nongenetic factors associated with variation of plasma levels of insulin-like growth factor-I and insulin-like growth factor-binding protein-3 in healthy premenopausal women.

Circulating levels of insulin-like growth factor-I (IGF-I) and insulin-like growth factor-binding protein 3 (IGFBP-3) vary considerably between normal individuals. Recent epidemiological studies have provided evidence that these levels are predictive of risk of several common cancers. To evaluate possible sources of variation of the levels of circulating IGF-I and IGFBP-3 in females, we studied specific candidate genetic and nongenetic factors in 311 nulliparous, premenopausal Caucasian women, 17-35 years of age. Women who used oral contraceptives (OC) had reduced levels of IGF-I (269 versus 301 ng/ml; P = 0.001 adjusted for age) and increased levels of IGFBP-3 (4213 versus 4009 ng/ml; P = 0.002, adjusted for age) compared with nonusers. The ratio of IGF-I:IGFBP-3 was associated with the dose of estrogen contained in the OC (P(trend) = 0.006, adjusted for age). We identified a novel single bp polymorphism in the promoter region of the gene encoding IGFBP-3. This polymorphism was related to the level of IGFBP-3 in the circulation. Mean IGFBP-3 levels were 4390, 4130, and 3840 ng/ml for the AA, AC, and CC genotypes, respectively (P(trend) = 0.006, adjusted for age and OC use). We observed no effect of a recently described polymorphism in the promoter region of the gene encoding IGF-I on the plasma IGF-I level, but there was evidence for a modifying effect of this locus on the influence of OC on the IGF-I level. Our results support the view that circulating IGF-I levels and IGFBP-3 levels are complex traits and are influenced by a number of interacting genetic and nongenetic factors.

Adolescent↗

Glycerol as a correlate of impaired glucose tolerance: dissection of a complex system by use of a simple genetic trait.

Glycerol kinase (GK) represents the primary entry of glycerol into glucose and triglyceride metabolism. Impaired glucose tolerance (IGT) and hypertriglyceridemia are associated with an increased risk of diabetes mellitus and cardiovascular disease. The relationship between glycerol and the risk of IGT, however, is poorly understood. We therefore undertook the study of fasting plasma glycerol levels in a cohort of 1,056 unrelated men and women of French-Canadian descent. Family screening in the initial cohort identified 18 men from five families with severe hyperglycerolemia (values above 2.0 mmol/liter) and demonstrated an X-linked pattern of inheritance. Linkage analysis of the data from 12 microsatellite markers surrounding the Xp21.3 GK gene resulted in a peak LOD score of 3.46, centered around marker DXS8039. In addition, since all of the families originated in a population with a proven founder effect-the Saguenay Lac-St.-Jean region of Quebec-a common disease haplotype was sought. Indeed, a six-marker haplotype extending over a region of 5.5 cM was observed in all families. Resequencing of the GK gene in family members led to the discovery of a N288D missense mutation in exon 10, which resulted in the substitution of a highly conserved asparagine residue by a negatively charged aspartic acid. Although patients with the N288D mutation suffered from severe hyperglycerolemia, they were apparently otherwise healthy. The phenotypic analysis of the family members, however, showed that glycerol levels correlated with impaired glucose metabolism and body-fat distribution. We subsequently noted a substantial variation in glycerolemia in subjects of the initial cohort with normal plasma glycerol levels and demonstrated that this variance showed significant family resemblance. These results suggest a potentially important genetic connection between fasting glycerolemia and glucose homeostasis, not only in this X-linked deficiency but, potentially, in individuals within the "normal" range of plasma glycerol concentrations.

Adult↗

Evidence for host-specific clades of tetraphyllidean tapeworms (Platyhelminthes: Eucestoda) revealed by analysis of 18S ssrDNA.

Sequence data from the V4 and V7-V9 variable regions of the 18S small subunit ribosomal DNA (ssrDNA) gene were used to examine relationships among 26 tetraphyllidean and two lecanicephalidean taxa. Newly collected specimens of 21 of the tetraphyllidean species were used to generate ssrDNA sequences that were combined with sequences previously available, including those of two diphyllidean taxa used for outgroup rooting. The sequences were aligned by eye according to secondary structural motifs of the conserved core of the molecule. Of the 1520 sites in the alignment, 874 (58%) were excluded from analysis due to alignment gaps and lack of positional homology as inferred by manual inspection. Genetic variability of the ssrDNA gene regions compared was greater than would be expected, based on the present taxonomy of the ingroup species, and the genetic divergences among tetraphyllidean 'families' and genera were comparable to that among tapeworm orders. Phylogenetic hypotheses were generated by the methods of maximum parsimony and maximum likelihood (GTR + I + Gamma nucleotide substitution model). Four most parsimonious trees resulted from analysis by maximum parsimony. Strict consensus of the four trees supported the monophyly of the Tetraphyllidea, with the lecanicephalidean taxa forming a sister lineage. Among the tetraphyllidean taxa included in the analysis were three major clades: a basal clade including species of the phyllobothriid genera Anthocephalum, Echeneibothrium, Rhinebothrium, Rhodobothrium and Spongiobothrium; a clade uniting the phyllobothriids of the genus Duplicibothrium with the dioecotaeniid genus Dioecotaenia; and a larger sister clade to the Duplicibothrium + Dioecotaenia clade that included the phyllobothriid genera Caulohothrium, Ceratobothrium, Clistobothrium, Paraoryigmatobothrium and Prosobothrium, the litobothriid genus Litobothrium and the onchobothriid genera Acanthobothrium, Calliobothrium, Phoreiobothrium and Platybothrium. Maximum likelihood analysis resulted in a topology that was congruent where nodes were strongly supported by parsimony analysis, but differed in the relative positions of the well-supported clades. In addition,maximum likelihood analysis grouped the lecanicephalidean taxa among the tetraphyllidean taxa, indicating paraphyly of the order Tetraphyllidea as currently defined. Relationships suggested by both methods of analysis reflected common host associations of the taxa better than their current classification, suggesting that coevolution has had a significant role in the evolution of the group.

Animals↗

Caring About Women and Cancer (CAWAC): a European survey of the perspectives and experiences of women with female cancers.

This paper reports on the findings of the largest ever European survey of female patients' perceptions of their cancer treatment. It has provided clarification of what women consider important in relation to their management and has identified several areas where more research is needed. It has shown that women's knowledge about cancer before diagnosis is poor and the number undergoing regular screening could be improved. Women are not being adequately prepared and educated about what to expect from treatment and steps should be taken as a matter of urgency to redress this shortcoming. It was revealed that whilst families were the primary source of support to female cancer patients, women also derive considerable support from healthcare professionals, particularly senior doctors; more attention should be paid by specialists and nurses to developing psychological skills to cope with this. In this context, further research is needed into how support groups may best meet patient needs.

Attitude to Health↗

Procedure to protect confidentiality of familial data in community genetics and genomic research.

The collection of familial data is an essential step for community genetics programs or genetic research. Ethical issues concerning privacy and confidentiality present a major challenge in such programs. In order to keep familial data confidential, we have developed a family-based numerical coding procedure which allows the use of confidential data and the determination of familial relationships without risk of disclosure. This procedure is composed of two parts: the physical separation of identifying information and individual data; and the use of a code containing all the information required to build family trees. This procedure has been used in Eastern Quebec since 1995, mainly for screening, genetic counseling, research on familial dyslipidemias, public health intervention, and research projects on the genetics of complex traits, such as arterial hypertension and coronary artery disease.

Abstracting and Indexing↗

Off target.

Leave it to the market. It's our collective corrective, the American way of problem-solving. So it's no surprise that we looked to the market to stop runaway health care costs. For awhile, it seemed to work. Medicare HMOs, physician practice management, risk contracting, and other innovations boomed. Then came the setbacks, exposing health care's complexities and contradictions--and reminding us that nothing escapes market discipline.

Advertising↗

Be on the lookout.

The cost coil tightens. The Net widens. Alternative care booms. And higher tech means more trade-offs. These and other trends play out in a new health care environmental assessment created by VHA and Deloitte & Touche--an Executive Chartbook exclusive to H&HN.

Consumer Behavior↗

Budget battlers ... profiles.

If managed care discounts give you a headache, you'll get a migraine figuring your losses from the 1997 Balanced Budget Act--they're an 8 on the Richter scale, says one hospital policy pro. The savvy aren't waiting to act: Around the country, hospitals are fighting the cuts on the national front and battling back at home. H&HN profiles five.

Aged↗

Cutting prospects.

Explore the source record for details and available documents.

Data Collection↗

Buy vs. bye.

At first, the retreat of practice management companies looked like a great opening for hospitals. What better way to acquire prime medical groups from motivated sellers? Trouble is, you still need a motivated buyer. That's why some observers contend hospitals will purchase only a fraction of medical groups being divested by MedPartners and other retrenching firms.

Decision Making, Organizational↗

A sharper point on using safer needles.

National legislation is just one sign of changing attitudes about safety needles. Fifteen states are considering similar bills; five already have passed such laws. OSHA also says it will put needlestick injuries on its agenda this fall. Yet if needlesticks and efforts to prevent them are nothing new, what's causing this change of heart? Two things: improved technology and media attention.

Equipment Design↗

Chartbook. Quality checkup.

With hospital quality programs, the reach is broad, not deep. So says the National Hospital Quality Improvement Survey, conducted by health care researcher Stephen Shortell for Arthur Andersen and the American Hospital Association. Though 93 percent of responding hospitals and health systems use CQI and TQM methods is some fashion, they've taught them to only 35 percent of employees and a scant 22 percent of doctors on their medical staffs. Those poor showings leave health care lagging behind most other industries.

Data Collection↗

Selling brand MD.

Health care is more than local, of course: It's personal. Recognizing the connections between doctors and patients as a potent form of brand loyalty, health systems are looking for ways to leverage those bonds--and encourage new ones--with special marketing campaigns.

Advertising↗