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At least 631 records · Page 35Linked to original sources
PubMed2007

Colour variation and alternative reproductive strategies in females of the common lizard Lacerta vivipara.

Within-sex colour variation is a widespread phenomenon in animals that often plays a role in social selection. In males, colour variation is typically associated with the existence of alternative reproductive strategies. Despite ecological conditions theoretically favourable to the emergence of such alternative strategies in females, the social significance of colour variation in females has less commonly been addressed, relative to the attention given to male strategies. In a population of the common lizard, females display three classes of ventral colouration: pale yellow, orange and mixed. These ventral colours are stable through individual's life and maternally heritable. Females of different ventral colourations displayed different responses of clutch size, clutch hatching success and clutch sex-ratio to several individual and environmental parameters. Such reaction patterns might reflect alternative reproductive strategies in females. Spatial heterogeneity and presence of density- and frequency-dependent feedbacks in the environment could allow for the emergence of such alternative strategies in this population and the maintenance of colour variation in females.

Animals↗
PubMed2005

Genetic variation in the growth hormone synthesis pathway in relation to circulating insulin-like growth factor-I, insulin-like growth factor binding protein-3, and breast cancer risk: results from the European prospective investigation into cancer and nutrition study.

Insulin-like growth factor-I (IGF-I) stimulates cell proliferation and can enhance the development of tumors in different organs. Epidemiologic studies have shown that an elevated level of circulating IGF-I is associated to increased risk of breast cancer as well as other cancers. Genetic variants affecting the release or biological action of growth hormone (GH), the main stimulator of IGF-I production, may predict circulating levels of IGF-I and have an effect on cancer risk. We tested this hypothesis with a large case-control study of 807 breast cancer patients and 1,588 matched control subjects nested within the European Prospective Investigation into Cancer and Nutrition. We genotyped 22 common single nucleotide polymorphisms in 10 genes involved in GH production and action (GHRH, GHRHR, SST, SSTR1-SSTR5, POU1F1, and GH1), and in parallel, we measured serum levels of IGF-I and IGFBP-3, its major binding protein, in samples of cases and controls. SST and SSTR2 polymorphisms showed weak but statistically significant associations with breast cancer risk. SSTR5 polymorphisms were associated with IGF-I levels, whereas one polymorphism in GHRHR and one in POU1F1 were associated with IGFBP-3 levels. Our conclusion is that common genetic variation in the GH synthesis pathway, as measured by single nucleotide polymorphisms selected in the present study, is not a major determinant of IGF-I and IGFBP-3 circulating levels, and it does not play a major role in altering breast cancer risk.

Adult↗
PubMed1999

Genetic variation in apolipoprotein H (beta2-glycoprotein I) affects the occurrence of antiphospholipid antibodies and apolipoprotein H concentrations in systemic lupus erythematosus.

Apolipoprotein H (apoH, protein; APOH, gene) is a required cofactor for the production of antiphospholipid antibodies (APA). In this study we have examined whether genetic variation in the APOH gene affects variation in risk for systemic lupus erythematosus (SLE), occurrence of antiphospholipid antibodies (APA), anti-apoH, and plasma apoH concentrations. A total of 222 white SLE women were screened for four APOH polymorphisms (codons 88, 247, 306, and 316) by polymerase chain reaction, and for plasma apoH concentrations by ELISA. Of these, 29.3% were positive for APA (APA-positive group) and 31.1% for anti-apoH. None of the four APOH polymorphisms were significantly associated with variation in risk for SLE. The codons 306 and 316 polymorphisms showed significant, gene-dosage effects on plasma apoH concentrations (P<0.0001) and explained 30% and 13%, respectively, of the residual variation in apoH concentrations. No significant association was observed between anti-apoH status and APOH polymorphisms or plasma apoH levels. However, plasma apoH concentrations were significantly higher in patients positive for APA than in patients negative for APA (18.5+/-4.0 mg/dl vs 17.1+/-3. 8 mg/dl; P=0.02). The distribution of the Trp316Ser polymorphism was significantly different between the APA-positive and APA-negative groups. The frequency of the mutant allele (Ser316) was significantly lower in the APA-positive group than the APA-negative group (3.1% vs 12.1% P<0.04), indicating that the Ser316 mutation is protective against the production of phospholipid-apoH dependent APA. Our data indicate that common genetic variation in the APOH gene is a significant determinant of plasma apoH variation in SLE patients, and the Trp316Ser polymorphism appears to provide protection against the production of APA in SLE patients.

Adult↗
PubMed2007

C-reactive protein, an 'intermediate phenotype' for inflammation: human twin studies reveal heritability, association with blood pressure and the metabolic syndrome, and the influence of common polymorphism at catecholaminergic/beta-adrenergic pathway loci.

BACKGROUND: C-reactive protein (CRP) both reflects and participates in inflammation, and its circulating concentration marks cardiovascular risk. Here we sought to understand the role of heredity in determining CRP secretion. METHODS: CRP, as well as multiple facets of the metabolic syndrome, were measured in a series of 229 twins, both monozygotic (MZ) and dizygotic (DZ), to estimate trait heritability (h2). Single nucleotide polymorphism (SNP) genotyping was done at adrenergic pathway loci. Haplotypes were inferred from genotypes by likelihood methods. Association of CRP with hypertension and the metabolic syndrome was studied in a larger series of 732 individuals, including 79 with hypertension. RESULTS: MZ and DZ twin variance components indicated substantial h2 for CRP, at approximately 56 +/- 7% (P < 0.001). CRP was significantly associated (P < 0.05) with multiple features of the metabolic syndrome in twins, including body mass index (BMI), blood pressure (BP), leptin and lipids. In established hypertension, elevated CRP was associated with increased BP, BMI, insulin, HOMA (index of insulin resistance), leptin, triglycerides and norepinephrine. Twin correlations indicated pleiotropy (shared genetic determination) for CRP with BMI (P = 0.0002), leptin (P < 0.001), triglycerides (P = 0.002) and systolic blood pressure (SBP) (P = 0.042). Approximately 9800 genotypes (43 genetic variants at 17 loci) were scored within catecholaminergic pathways: biosynthetic, receptor and signal transduction. Plasma CRP concentration in twins was predicted by polymorphisms at three loci in physiological series within the catecholamine biosynthetic/beta-adrenergic pathway: TH (tyrosine hydroxylase), ADRB1 (beta1-adrenergic receptor) and ADRB2 (beta2-adrenergic receptor). In the TH promoter, common allelic variation accounted for up to approximately 6.6% of CRP inter-individual variance. At ADRB1, variation at Gly389Arg predicted approximately 2.8% of CRP, while ADRB2 promoter variants T-47C and T-20C also contributed. Particular haplotypes and diplotypes at TH and ADRB1 also predicted CRP, though typically no better than single SNPs alone. Epistasis (gene-by-gene interaction) was demonstrated for particular combinations of TH and ADRB2 alleles, consistent with their actions in a pathway in series. In an illustration of pleiotropy, not only CRP but also plasma triglycerides were predicted by polymorphisms at TH (P = 0.0053) and ADRB2 (P = 0.027). CONCLUSIONS: CRP secretion is substantially heritable in humans, demonstrating pleiotropy (shared genetic determination) with other features of the metabolic syndrome, such as BMI, triglycerides or BP. Multiple, common genetic variants in the catecholaminergic/beta-adrenergic pathway contribute to CRP, and these variants (especially at TH and ADRB2) seem to interact (epistasis) to influence the trait. The results uncover novel pathophysiological links between the adrenergic system and inflammation, and suggest new strategies to probe the role and actions of inflammation within this setting.

Adult↗
PubMed2004

A module map showing conditional activity of expression modules in cancer.

DNA microarrays are widely used to study changes in gene expression in tumors, but such studies are typically system-specific and do not address the commonalities and variations between different types of tumor. Here we present an integrated analysis of 1,975 published microarrays spanning 22 tumor types. We describe expression profiles in different tumors in terms of the behavior of modules, sets of genes that act in concert to carry out a specific function. Using a simple unified analysis, we extract modules and characterize gene-expression profiles in tumors as a combination of activated and deactivated modules. Activation of some modules is specific to particular types of tumor; for example, a growth-inhibitory module is specifically repressed in acute lymphoblastic leukemias and may underlie the deregulated proliferation in these cancers. Other modules are shared across a diverse set of clinical conditions, suggestive of common tumor progression mechanisms. For example, the bone osteoblastic module spans a variety of tumor types and includes both secreted growth factors and their receptors. Our findings suggest that there is a single mechanism for both primary tumor proliferation and metastasis to bone. Our analysis presents multiple research directions for diagnostic, prognostic and therapeutic studies.

Databases, Genetic↗
PubMed1988

Occult thyroid pathology in the young adult: an autopsy study of 138 patients without clinical thyroid disease.

Thyroid glands from autopsies on 138 adults, ages 20 to 40 years, with no known clinical or laboratory evidence of thyroid disease, were serially sectioned at 2 mm intervals and microscopically examined for occult thyroid disease and anatomic variations. Occult papillary carcinoma was found in 3% of the glands, along with a single case of medullary carcinoma. The prevalence of occult thyroid carcinoma in this group of young adults is significantly less than that reported in the literature in people over forty (P less than .001). The glands demonstrated a number of other morphologic changes of importance to surgical pathologists. The thyroid capsule was incomplete in 62% of the glands. Thyroid follicles were found in the capsule in 14% of cases and thyroid follicles or nodules were outside the gland in perithyroid connective tissue in 88% of cases. Thyroid follicles were identified in 7% of cases in perithyroid strap muscles attached to the pyramidal lobe. A number of other, less common anatomic variations were also seen.

Adenoma↗
PubMed2005

Embryogenesis of chimeras, twins and anterior midline asymmetries.

Human spontaneous chimerism, with one body built from cells of both twins of a dizygotic (DZ) pair, is supposed to be extremely rare, arising from the exchange of blood cells through placental anastomoses. Mosaicism is supposed to be far more common, arising from single zygotes by embryonic mutation. Because typical diagnosis of mosaicism can neither identify nor exclude chimerism, 'mosaicism' may often be chimerism undiscovered. Evidence shows chimerism arises primarily from DZ embryo fusion and is not rare, although it has negligible probability under the hypothesis of independent double ovulation and independent embryogenesis. If, instead, DZ twin embryos begin development as a single cell mass, chimerism is likely. This would be consistent with observations that DZ twins develop as differently from singletons as monozygotic twins do with regard to embryogenic establishment of asymmetries of midline neural-crest-driven structures of brain, face and heart. Chimerism is a significant component of human embryonic development that deserves closer attention as a mechanism of developmental variation. The 'common knowledge' understanding of twinning mechanisms is at best inadequate. The importance of the difference lies in what we can learn from chimerism about human embryogenesis and the cellular origins of structures and functions basic to the business of becoming human.

Chimera↗
PubMed1998

A survey of family physicians and psychiatrists. Psychotropic prescribing practices and educational needs.

The purpose of this study was to compare the psychotropic prescribing practices of family physicians and psychiatric physicians, and to assess their satisfaction with education about psychotropic prescribing. A survey was mailed to 461 active members of the Minnesota Psychiatric Society and to a randomized sample of 461 active members of the Minnesota Academy of Family Physicians. Major depression, panic disorder, and dementia with behavioral disturbance were selected for study. For each disorder, we asked for the estimated number of patients seen and treated as well as a list in order of preference of the three medications they most commonly use. Those surveyed were also asked about their level of satisfaction with the training they received in medical school, residency, and continuing medical education (CME) courses on the topic of psychotropic prescribing. The two physician groups reported similar prescribing practices for the single-drug treatment of depression. Family physicians more frequently prescribed minor tranquilizers and older generation psychotropics than did psychiatrists when treating panic disorder and dementia with behavioral disturbance. Patients with depression were the least likely to be referred to other health professionals. Neither physician group was satisfied with medical school education in this area; family physicians were less satisfied with residency training and in related CME courses than were psychiatric physicians. Additional study is needed to better understand interspecialty practice variation for commonly encountered psychiatric disorders. Medical education programs at all levels could better meet the reported needs of their graduates by providing more attention to prescribing psychotropic agents.

Adolescent↗
PubMed2026

Type 2 diabetes genetics in 125,000 admixed adults from Mexico City.

Type 2 diabetes (T2D) is a highly heritable, polygenic disease with over 600 loci identified through genome-wide association studies (GWAS). However, despite possessing unique genetic variation shaped by demographic history and admixture, Latin American populations remain markedly underrepresented in global genomic research. To address this gap, we conducted genome- and exome-wide analyses of 19,431 T2D cases and 105,611 controls from the Mexico City Prospective Study (MCPS). We identified 86 independent GWAS associations, including 21 novel signals, 15 of which replicated in external cohorts. Risk alleles at novel loci were enriched in individuals with Indigenous American ancestry. Exome analyses revealed rare and ultra-rare missense variants with substantial risk effects at HNF1A and GCK, as well as a protein-damaging variant in SLC30A8 that reduced T2D risk by 45% in carriers. Integrative analyses indicate that T2D genetic architecture in Mexico is predominantly driven by common regulatory variation acting in the endocrine pancreas. Polygenic risk scores strongly stratified T2D risk and transferred to Indigenous Mexican populations. These findings demonstrate the power of large-scale genetic discovery in diverse populations to refine disease architecture and identify loci with potential therapeutic relevance.

Journal Article↗
PubMed1996

Genetic basis of variation in carotid artery wall thickness.

BACKGROUND AND PURPOSE: Other than the documented associations of risk factors and carotid artery wall thickness, the genetic basis of variation in carotid artery intimal-medial thickness (IMT) is unknown. The purpose of this study was to examine the extent to which variation in common carotid artery (CCA) IMT and internal carotid artery (ICA) IMT are under genetic control. METHODS: The sibship data used for this analysis were part of an epidemiological survey in Mexico City. The CCA and ICA analyses were based on 46 and 44 sibships of various sizes, respectively. The CCA and ICA IMTs were measured with carotid ultrasonography. Using a robust variance decomposition method, we performed genetic analyses of CCA IMT and ICA IMT measurements with models incorporating several cardiovascular risk factors (eg, lipids, diabetes, blood pressure, and smoking) as covariates. RESULTS: After accounting for the effects of covariates, we detected high heritabilities for CCA IMT (h2 = 0.92 +/- 0.05, P = .001) and ICA IMT (h2 = 0.86 +/- 0.13, P = .029). Genes accounted for 66.0% of the total variation in CCA IMT, whereas 27.7% of variation was attributable to covariates. For ICA IMT, genes explained a high proportion (74.9%) of total phenotypic variation. The covariates accounted for 11.5% of variation in ICA IMT. CONCLUSIONS: Our results suggest that substantial proportions of phenotypic variance in CCA IMT and ICA IMT are attributable to shared genetic factors.

Cardiovascular Diseases↗
PubMed1999

Absence of association between genetic variation in the LIPC gene promoter and plasma lipoproteins in three Canadian populations.

The promoter sequence variant -480T in the hepatic lipase gene (LIPC) has been shown to be significantly associated with low post-heparin hepatic lipase activity. Some studies have also found that the -480T variant is associated with elevation in plasma HDL cholesterol. We tested for associations of LIPC -480T with plasma lipoprotein traits in samples taken from three distinct Canadian populations: 657 Alberta Hutterites, 328 Ontario Oji-Cree and 210 Keewatin Inuit. Plasma HL activity was not available for analyses. The LIPC -480T allele frequencies in these three groups, respectively, were 0.219, 0.527 and 0.383, and the prevalence of LIPC -480T/T homozygotes was, respectively, 0.042, 0.274 and 0.167. No significant association was found between LIPC -480T and plasma HDL cholesterol or apolipoprotein AI concentration, after adjusting for covariates including gender and body mass index. There was no consistent relationship between the population mean plasma HDL cholesterol concentration and the population LIPC -480T frequency. Our findings are consistent with the idea that the common promoter variation in LIPC, which has been reported to be associated with variation in post heparin HL activity and HDL triglyceride concentration, is not always associated with variation in plasma HDL cholesterol concentration, possibly due to yet unspecified environmental or genetic factors.

Adolescent↗
PubMed2006

Variation at the DAOA/G30 locus influences susceptibility to major mood episodes but not psychosis in schizophrenia and bipolar disorder.

CONTEXT: Variation at the DAOA/G30 locus has been described to be associated with both schizophrenia and bipolar disorder, but there is little consistency between studies of the tested polymorphisms or variants showing association. OBJECTIVES: To obtain a stringent replication of association in large samples of both disorders using consistent clinical and laboratory methods, and to test the hypothesis that association at DAOA/G30 identifies an underlying domain of psychopathological abnormalities that cuts across traditional diagnostic categories. DESIGN: A systematic study of polymorphisms at DAOA/G30 using genetic case-control association analysis. SETTING: Subjects were unrelated and ascertained from general psychiatric inpatient and outpatient services. PARTICIPANTS: White persons from the United Kingdom meeting criteria for DSM-IV schizophrenia (n = 709) or bipolar I disorder (n = 706) and 1416 ethnically matched controls. METHODS: Nine polymorphisms that tag common genetic variations at DAOA/G30 were genotyped in all of the individuals, and comparisons were made between affected and unaffected individuals. RESULTS: We identified significant association (P = .01-.047) between 3 single-nucleotide polymorphisms and bipolar disorder but failed to find association with schizophrenia. Analyses across the traditional diagnostic categories revealed significant evidence (P = .002-.02) for association with 4 single-nucleotide polymorphisms in the subset of cases (n = 818) in which episodes of major mood disorder had occurred (gene-wide P = .009). We found a similar pattern of association in bipolar cases and in schizophrenia cases in which individuals had experienced major mood disorder. In contrast, we found no evidence for association in the subset of cases (n = 1153) in which psychotic features occurred (all P>.08). CONCLUSIONS: Despite being originally described as a schizophrenia susceptibility locus, our data suggest that variation at the DAOA/G30 locus does not primarily increase susceptibility for prototypical schizophrenia or psychosis. Instead, our results imply that variation at the DAOA/G30 locus influences susceptibility to episodes of mood disorder across the traditional bipolar and schizophrenia categories.

Bipolar Disorder↗
PubMed2002

Sudden infant death: no evidence for linkage to common polymorphisms in the uncoupling protein-1 and the beta3-adrenergic receptor genes.

UNLABELLED: Thermal stress has been postulated to play a major role in the aetiology of sudden infant death (SID). The human uncoupling protein-1 (UCP-1), expressed in brown adipose tissue dissipates the transmitochondrial proton gradient as heat and plays a central role in energy homeostasis and thermogenesis. A common Bcl I polymorphism in the promoter region of the UCP-1 gene is associated with reduced UCP-1 adipose tissue mRNA and obesity. In addition, a common sequence variation in the beta3-adrenergic receptor gene (beta3-AR), Trp64Arg, has been linked to a decreased resting metabolic rate. To determine whether the UCP-1 Bcl I polymorphism and/or the Trp64Arg variant of beta3-AR are associated with the occurrence of SID, we determined the allele frequencies of these polymorphisms in 53 Austrian SID victims and 54 controls by nested PCR and restriction digestion using DNA extracted from Guthrie cards. We found that the allele frequencies of both polymorphisms did not differ between the SID and control groups (0.65/0.35 versus 0.72/0.28 for UCP-1 Bcl I, and 0.89/0.11 versus 0.93/0.07 for beta3-AR Trp64Arg in SID victims versus controls, respectively). CONCLUSION: Our data do not support a major association between the occurrence of sudden infant death and two common functional polymorphisms in the human uncoupling protein-1 and beta3-adrenergic receptor genes.

Austria↗
PubMedDate not supplied

[Genetic variations of the tumor suppressor TP53: outstanding and strategies of analysis].

In the modern society, cancer remains an important cause of death. Cancer development is a very complex process that involves alterations in genes regulating cellular growth. Among these alterations or variations, are included point mutations, genetic susceptibility by single nucleotide polymorphisms or "SNP" and alteration or loss in tumor suppressor genes functions. The tumor suppressor TP53 is one of the most important and studied genes on cancer genetics. Therefore, it has been demonstrated that TP53 present mutations in more than 50% of all types of human cancer and encodes a multifunctional protein whose absence contributes to genomic instability, the accumulation of mutations and increased tumor development. The identification of such alterations in cancerous cells at level of single nucleotide is very important, because its implication in the loss or alteration in the function of this gene, its clinical relevance and finally, its association with response to therapy and prognosis. Due to the large interesting issue, in this work we are focused only in two of the most common genetic variations present in this gene: the point mutations and SNP remarking some outstanding molecular characteristics needed for design its analysis.

Cocarcinogenesis↗
PubMed2004

Late life metabolic syndrome, early growth, and common polymorphism in the growth hormone and placental lactogen gene cluster.

Low rates of fetal and infant growth are associated with the metabolic syndrome and cardiovascular disease in later life. We investigated common genetic variation in the GH-CSH gene cluster on chromosome 17q23 encoding GH, placental lactogens [chorionic somatomammotropins (CSH)], and placental GH variant in relation to fetal and infant growth and phenotypic features of the metabolic syndrome in subjects aged 59-72 yr from Hertfordshire, UK. Allele groups T, D1, and D2 of a locus herein designated CSH1.01 were examined in relation to GH-CSH single nucleotide polymorphisms and to specific phenotypes. Average birth weights were similar for all genotype groups. Men with T alleles were significantly lighter at 1 yr of age, shorter as adults, and had higher blood pressures, fasting insulin (T/T 66% higher than D2/D2) and triglyceride concentrations, and insulin and glucose concentrations during a glucose tolerance test. Birth weight and 1-yr weight associations with metabolic syndrome traits were independent of the CSH1.01 effects. Common diversity in GH-CSH correlates with low 1-yr weight and with features of the metabolic syndrome in later life. GH-CSH genotype adds substantially to, but does not account for, the associations between low body weight, at birth and in infancy, and the metabolic syndrome.

Aged↗
PubMed2001

Flavonoid sequestration by the common blue butterfly Polyommatus icarus: quantitative intraspecific variation in relation to larval hostplant, sex and body size.

Common blue butterflies (Polyommatus icarus) sequester flavonoids from their larval food and store these pigments as part of their adult wing colouration. Insects were reared on 10 different diets to assess effects of host plants on variation in flavonoid sequestration in this moderately polyphagous butterfly. Rearing experiments revealed an unexpectedly large gradient in flavonoid richness, ranging from individuals with high flavonoid loads (reared on inflorescences of Medicago sativa, Trifolium repens, T. pratense) to butterflies which contained almost no such pigments (fed with foliage of M. sativa or Robinia pseudoacacia). Flavonoid sequestration was much more effective from natural hostplants than from experimentally offered diets which would not be accepted in the field. Female butterflies on average sequestered almost 60% more flavonoids than males. This sex difference was more pronounced on natural than on experimental diets. Flavonoid load was significantly and positively related to dry mass and forewing length as two important fitness correlates of butterflies. This correlation was particularly strong on experimental diets (i.e. under constraining conditions for development). On natural hostplants, in contrast, when butterflies generally were flavonoid-rich, no clear relationship between flavonoid load and size or mass emerged. Our analytical data are consistent with field results according to which females rich in UV-absorbing flavonoid wing pigments are more attractive to mate-searching males. In P. icarus, flavonoid richness might therefore increase visibility (by more effective sensory stimulation of the visual system), but could also confer information about the feeding history, and thus ontogenetically determined 'quality' of a potential mate.

Journal Article↗
PubMedDate not supplied

The complexity of the genotype-phenotype relationship and the limitations of using genetic "markers" at the individual level.

Many associations have recently been discovered between phenotypic variation and genetic loci, causing some to advocate what Robert Sinsheimer has called "a new eugenics" that would treat genetic "defects" in individuals prone to a disease. The first premise of this vision is that genetic association studies reveal the biological cause of the phenotypic variation. Once the responsible genes are known, the second premise is that we should focus upon changing "nature" rather than "nurture" by correcting the "defective" genes. The first premise is flawed because associations between genetic markers and phenotypes can be spurious, as shown by an example. Moreover, it is shown that using non-causative but associated genetic markers one at a time (the normal practice) can lead to incorrect predictions of disease risk for many individuals. Going from association to causation is a non-trivial step scientifically that has rarely been done in much of the human genetic research. Even when a particular locus does contribute to the phenotypic variation of interest, the first premise remains flawed because phenotypes in general arise from complex interactions among genes and between genes and environments as shown for genes associations with coronary artery disease (CAD). The ability of current molecular genetic tools to "fix" defective genotypes is extremely limited, but even if the technological problems could be overcome, the studies on CAD reveal no obvious "defective" gene to fix because the genetic effects are so context dependent (upon both other genes and environmental factors). Contrary to the second premise of the new eugenics, the more we learn about how different genotypes show variable responses to environments, the more important the environment becomes for individual treatment. The paradigm of a "defective gene" may work for classical Mendelian genetic diseases that are due to loss-of-function mutations. However, such mutations affect only a small portion of humanity. When the focus is changed to common disease and behavioral phenotypes, the "defective gene" paradigm is biologically meaningless and often harmful when applied to individuals. Thus, even when genes clearly do influence common phenotypic variation, the premises of the "new eugenics" are biologically indefensible.

Alzheimer Disease↗
PubMed2006

Ethical decision making on truth telling in terminal cancer: medical students' choices between patient autonomy and family paternalism.

INTRODUCTION: The effect of medical education is often hard to evaluate. We tried to assess whether a 2-hour, small-group discussion could alter student perspectives on truth telling. Currently, in Taiwan it is common practice to consult with the family of a terminally ill patient before telling the truth to the patient, which may be in conflict with patient autonomy. METHODS: The study was based on content analysis of self-reflective written texts after a 2-hour group discussion on a clinical case describing a truth-telling situation. The changes in decision patterns regarding the emphasis placed on patient autonomy versus family paternalism and the connection to related moral reasoning were subjected to focus analysis. RESULTS: The students' initial attitudes regarding the subject of truth telling were categorised into 4 patterns, namely, patient-centred (n = 46), family-centred (n = 20), simultaneous informing (n = 1), and situational informing (n = 5) modes. The discussion stimulated perspective changes in many of the students and their attitudes were then regrouped as patient-comprehensive (n = 35), family-centred (n = 1), and family-comprehensive (n = 36) modes. It was found that variations on 'common sense' and moral reasoning existed prior to the class and the students initially tended to overlook the complexity of truth telling in terminal cancer. Through the discussion and reflective learning, they were enabled to acknowledge the vulnerability of both the patient and his or her family, and to make decisions based on more comprehensive considerations. CONCLUSION: Group discussion seemed to be able to enhance ethical consideration. Further research is required to determine whether the benefits of this approach can be translated into behavioural changes in practice.

Attitude of Health Personnel↗