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PubMed2001

Comparative proteomics of bacterial pathogens.

The monitoring of gene expression via the technologies encompassed under the term 'proteomics' allows proteins of significance to be related to phenotypes associated with strain variability, environmental influences and the effects of genetic manipulation. The characterizations of these molecules are routinely performed utilising two-dimensional (2-D) gel electrophoresis in association with mass spectrometry for the identification of proteins. Pathogenic bacteria are suitable for proteomic comparisons in the aim of elucidating proteins with vaccine and diagnostic applications, as well as determining novel targets for drug design and the effects of these drugs on cellular physiology. Strains exhibiting diverse phenotypes including antibiotic or chemical resistances, altered mode of pathogenicity, or differential capability of growth in similar environments, can be compared via protein differential display to correlate relative protein abundances associated with these conditions. Technically, proteins are 'mapped' on 2-D arrays under 'standard' conditions and visually compared to arrays of proteins from a variety of test conditions. High-throughput technologies allow molecules of significance to be elucidated rapidly from within complex mixtures using a combination of cellular pre fractionation to determine cellular location and pathway predictions to aid in overcoming the limitations of 2-D gel technology for the analysis of whole proteomes.

Bacteria↗
PubMed1990

Avian models of experimental myopia: environmental factors in the regulation of eye growth.

During normal development a precise match between the length of the path of light within the eye and the refractive state of the eye's optical elements is required for the retinal image to remain sharply in focus. Recent studies have shown that this match between eye growth and refractive state is partially under the control of environmental factors. Investigations in several species of ground-foraging birds have shown the existence of an optical mechanism that maintains the retinal image of the ground in focus on the upper retina without a change in accommodation, when the bird is standing erect. Moreover, as a young bird grows, the refractive state changes to maintain a sharp focus of the retinal image of the ground. These findings suggest that the quality of the retinal image may be an important regulator of the matching of refractive state to growth of the ocular globe. We have found in young, rapidly growing birds that the application of optical devices that degrade the quality of the retinal image interferes with the normal regulation of eye growth and results in excessive growth and severe myopia. Additional environmental variables that affect eye growth include nutritional deficiencies of calcium and vitamin D and elevated ocular temperature.

Animal Nutritional Physiological Phenomena↗
PubMed1978

Nasal mucociliary clearance in man.

Nasal mucociliary clearance was measured in healthy young human subjects and tracheal clearance in the experimental animal under a wide variety of conditions. There is a broad range of clearance rates whether at standard ambient conditions (23 degrees C, 50% relative humidity) or in the face of a number of environmental variables. The degree to which those differences are attributable to the effectiveness of ciliary beating or the character of airway secretions is not known. Studies of tracheobronchial secretions simultaneous with clearance measurement in the anaesthetized dog have not yet provided a definite answer. Variations in upper respiratory defence mechanisms may bear some relationship to the aetiology of small airway disease in the lungs.

Adult↗
PubMed2004

Evidence for linkage between regulatory enzymes in glycolysis and schizophrenia in a multiplex sample.

Observations of impaired glucose regulation in schizophrenia are long-standing, although their pathological and etiological significance is uncertain. One approach to the issue that minimizes environmental variables (e.g., medication and diet) is to determine whether genes related to glucose regulation show genetic linkage to schizophrenia. We examined the potential role of glucose metabolism in schizophrenia through a genome scan of affection status in schizophrenia and an empirical method for deriving P-values. Data were utilized from the NIMH Genetics Initiative for Schizophrenia dataset, which comprises a total sample consisting of 71 pedigrees containing 218 nuclear families and 987 individuals. A genome scan with 459 markers spaced at an average of 10 cM intervals was conducted using the linkage analysis program Genehunter separately for European- and African-American groups. Enzymes that regulate glycolysis were identified and the genes regulating these enzymes were located through the Online Mendelian Inheritance in Man (OMIM) website. The focus in this study was on genes located near previously reported schizophrenia susceptibility regions. The genome-wide significance of these genes to schizophrenia was assessed using permutation testing. When results were adjusted for multiple testing within and across ethnic groups, 6-phosphofructo-2-kinase/fructose-2,6-bisphosphatase 2 (PFKFB2; chromosome 1q32.2) achieved genome-wide significance (P = 0.04). In addition, hexokinase 3 (HK3; chromosome 5q35.3) was also suggestive of linkage (P = 0.09). For the European-American sample, PFKFB2 (1q32.2), hexokinase 3 (HK3; 5q35.3), and pyruvate kinase 3 (PK3; chromosome 15q23) achieved significance at the 0.05 level. None of the genes showed significance in the African-American sample. Our results provide further support for the view that genes that regulate glucose metabolism may also influence susceptibility to schizophrenia. More generally, they support the view that relationships between glucose dysregulation and schizophrenia are inherent to the disorder, and are not merely epiphenomena related to medication or other treatment factors.

Black or African American↗
PubMed1989

Race differences in pubic symphyseal aging patterns in the male.

A well-documented multiracial sample of 704 male pubic bones allows for rigorous testing for racial differences in pubic symphyseal metamorphosis. The relationship between estimated age (using a modified Todd six-stage system) and age is examined as a function of race (White, Black, Mexican). One set of analyses incorporates linear regression models, while a second set does not impose such structure on the relationship. The latter analyses incorporate analysis of variance and related procedures. Significant differences in age are found across racial groups; it is seen that Blacks and Mexicans with advanced pubic symphyseal patterns tend to have lower ages than Whites. We do not address the question of causality, which may involve genetic factors and/or environmental variables such as diet, alcoholism, or drug abuse.

Adolescent↗
PubMed1990

Genetic epidemiological study of blood pressure in a sedentary rural agricultural population of West Bengal, India.

To study the genetic epidemiology of blood pressure (BP), data on 78 families were collected from a sedentary agricultural population of eastern India. The general levels of both systolic (SBP) and diastolic (DBP) blood pressures are found to be low (mean SBP = 106.41 mm Hg; mean DBP = 63.94 mm Hg). Trends of blood pressures with age are similar to those reported earlier (e.g., in the Framingham study). Environmental variables--e.g., occupation and tobacco use--do not have any direct significant effect on blood pressure variability in this population. Path analysis of family data shows a highly significant familial aggregation and yields a genetic heritability (maximum) estimate of 0.3 for both SBP and DBP. Sib-sib and mother-child correlation estimates are, respectively, 0.3 and 0.25. Father-child correlation estimates are 0.13 for SBP and near zero for DBP. A pseudopolygenic model yields the best fit to the data on SBP, while for DBP a proper resolution of various models considered could not be obtained.

Adolescent↗
PubMed2006

Life in the slow lane revisited: ontogenetic separation between chimpanzees and humans.

This study investigates the evolution of human growth by analyzing differences in body mass growth trajectories among three populations: the Ache of eastern Paraguay, the US (NHANES, 1999-2000), and captive chimpanzees. The relative growth statistic "A" from the mammalian growth law is allowed to vary with age and proves useful for comparing growth across different ages, populations, and species. We demonstrate ontogenetic separation between chimpanzees and humans, and show that interspecific differences are robust to variable environmental conditions. The human pattern of slow growth during the lengthened period from weaning to the beginning of the adolescent growth spurt is found among the Ache (low energy availability and high disease load) and also in the US (high energy availability and low disease load). The human growth pattern contrasts with that of the chimpanzee, where absolute growth rates and relative "A" values are faster and less prolonged. We suggest that selection has acted to decrease human growth rates to allow more time for increased cognitive development with lower body-maintenance costs.

Animals↗
PubMed1980

Amyotrophic lateral sclerosis among Chamorro migrants from Guam.

Amyotrophic lateral sclerosis (ALS), which occurs in unusually high incidence among the Chamorro people on the island of Guam, has developed in 28 Chamorro migrants--24 of whom had onset in the United States, Japan, Germany, or Korea--after periods of absence from Guam of 1 to 34 years. Thus, the latency period for the disease, if caused by environmental factors on Guam, may be over three decades. Four further patients developed ALS within 1 to 14 years of their return to Guam after long-term residence in the continental United States. The minimum exposure time to environmental variables on Guam, based on age at migration, was 18 years, and all patients had spent their childhood and adolescence on Guam. Estimates of crude mortality rates for ALS from these data are considerably higher than for the United States population, and lower than the ALS mortality rates for nonmigrant Chamorros on Guam.

Adult↗
PubMed2004

Anxiety and dissection of the human cadaver: an unsolvable relationship?

Anxiety is an emotional reaction frequently shown by students when a human cadaver is being dissected. Nonetheless, few studies analyze the nature of the anxiety response in this situation and the ones that do exist are mainly limited to English-speaking countries. Our research has three aims: to study the characteristic anxiety reaction to dissection practices, to determine the weight exerted by internal and environmental variables on this anxiety reaction, and to design practices aimed at reducing the state of anxiety experienced by pupils in their human anatomy practices. The studies were carried out in the dissection room of the Department of Human Anatomy and Embryology II at the Faculty of Medicine of the Complutense University, Madrid, during the 3 academic years 2000-2003. The anxiety response to the first dissection of a human cadaver is mainly determined by a situation considered to be threatening, with novelty as its main characteristic. The students' anxiety response is first determined by the situation itself and reactions depend on individual differences. Repeated or gradual exposure (detailed verbal information on the situation, visits to dissecting rooms when no cadaver is present, videos showing pictures of human dissections, etc.) before carrying out the first dissection reduce the students' anxiety response.

Anatomy↗
PubMed2025

Immune Aging in Rheumatoid Arthritis.

Rheumatoid arthritis (RA) is a life-long autoimmune disease caused by the confluence of genetic and environmental variables that lead to loss of self-tolerance and persistent joint inflammation. RA occurs at the highest incidence in individuals >65 years old, implicating the aging process in disease susceptibility. Transformative approaches in molecular immunology and in functional genomics have paved the way for pathway paradigms underlying the replacement of immune homeostasis with autodestructive immunity in affected patients, including the process of immune aging. Patients with RA have a signature of premature immune aging, best understood for CD4+ T cells, which function as pathogenic effectors in this HLA class II-associated disease. Premature immune aging is present in healthy HLA-DRB1*04+ individuals, placing accelerated immune aging before joint inflammation. Aging-related molecular abnormalities directly implicated in turning RA CD4+ T cells into proinflammatory effector cells are linked to malfunction of subcellular organelles, such as mitochondria, lysosomes, lipid droplets, and the endoplasmic reticulum. Resulting changes in T cell behavior include cellular hypermobility, tissue invasiveness, unopposed mammalian target of rapamycin complex (mTORC)1 activation, excessive release of tumor necrosis factor, lysosomal failure, clonal expansion, and immunogenic cell death. Aged and metabolically reprogrammed T cells in patients with RA are accompanied by age-associated B cells, which specialize in autoantibody production. Clonal hematopoiesis drives myeloid cell aging by producing aged monocytes and hypermetabolic macrophages, which sustain the process of inflammaging. Here, we synthesize insights into the relationship of RA risk and immune aging and discuss mechanisms through which immune aging can cause autoimmunity.

Humans↗
PubMed2026

Panmixia in a Widespread Butterfly: High Dispersal and Ecological Generalism Buffer Against Landscape Fragmentation.

Habitat fragmentation is widely expected to reduce population connectivity and increase genetic differentiation, although the strength of these effects depends on species-specific traits such as dispersal ability. Here, we investigated the population genetic structure of the cosmopolitan butterfly, Pieris rapae L. (Lepidoptera: Pieridae), across western Germany using genome-wide single-nucleotide polymorphism (SNP) data. To analyze the effects of landscape structure on genetic connectivity, we applied a paired study design comprising four landscape pairs, each consisting of a highly intensified, modern agricultural landscape and a more heterogeneous, traditional landscape. Our results revealed no evidence of genetic differentiation. Pairwise FST values were close to zero; we detected no isolation by distance, and clustering analyses supported a single genetic population. No meaningful associations between genetic variation and environmental variables were detected, with landscape effects explaining less than 0.4% of genomic variation. Consequently, we found no evidence for stronger genetic structuring in modern compared to more connected traditional landscapes. Our results suggest that extensive habitat fragmentation does not necessarily translate into reduced genetic connectivity in highly mobile, generalist species. In P. rapae , high dispersal ability and ecological generalism appear to buffer against the genetic consequences of landscape modification, resulting in panmictic population structure even across strongly contrasting agricultural landscapes.

Pieris rapae↗
PubMed2004

Haplotype-based association analysis in cohort studies of unrelated individuals.

Exploring the associations between haplotypes and disease phenotypes is an important step toward the discovery of genes that influence complex human diseases. When unrelated subjects are sampled, haplotypes are often ambiguous because of the unknown gametic phase of the measured sites along a chromosome. We consider cohort studies of unrelated subjects which collect data on potentially censored ages of onset of disease along with unphased genotypes and possibly time-varying environmental factors. We formulate the effects of haplotypes and environmental variables on the time to disease occurrence through a semiparametric Cox proportional hazards model, which can accommodate a variety of genetic mechanisms as well as gene-environment interactions. We develop a simple and fast expectation-maximization algorithm to maximize the likelihood for the relative risks and other parameters based on the observable data of unphased genotypes and potentially censored ages of onset. The resultant estimators are consistent, efficient, and asymptotically normal. Simulation studies show that, for practical situations, the parameter estimators are virtually unbiased, the association tests maintain type I errors near nominal levels, the confidence intervals have proper coverage probabilities, and the efficiency loss due to unknown gametic phase is small.

Algorithms↗
PubMed2001

GAW12: simulated genome scan, sequence, and family data for a common disease.

The Genetic Analysis Workshop (GAW) 12 simulated data involves a common disease defined by imposing a threshold on a quantitative liability distribution. Associated with the disease are five quantitative risk factors, a quantitative environmental exposure, and a dichotomous environmental variable. Age at disease onset and household membership were also simulated. Genotype data, including 2,855 microsatellites on 22 autosomes, were simulated for 1,497 individuals in 23 families. Phenotype data and sequence data for seven candidate genes were provided for 1,000 of these individuals who were "living" and available for study. Data were simulated for 50 replicate samples in each of two populations, a general population and a population isolate formed from a small group of founders.

Adolescent↗
PubMed2003

Comorbidity and risk-patterns of depression, generalised anxiety disorder and mixed anxiety-depression in later life: results from the AMSTEL study.

BACKGROUND: Depression and generalised anxiety disorder frequently overlap. The question remains unresolved whether these are specific disorders, or that they represent different dimensions of a single disorder. Although both are highly prevalent disorders in this age group, studies on this issue in the elderly are scarce. Research is needed that investigates patterns of comorbidity and possibly different risk profiles for pure depression, pure generalised anxiety and mixed anxiety-depression in older people. METHODS: GMS-AGECAT diagnoses were obtained from 4051 community living older persons. Comorbidity was studied along a severity gradient for men and women separately. Multivariate analysis of risk factors included demographic variables, environmental vulnerability, longstanding vulnerability, physical/functional stresses and gender. RESULTS: The prevalence of pure depression was 12.2%, pure generalised anxiety 2.9%, mixed anxiety-depression 1.8%. Comorbidity increased with higher severity levels of both depression and generalised anxiety. Comorbidity was twice as likely in women than in men. Different risk profiles for diagnostic categories were not demonstrated for concurrent risk factors. Longstanding vulnerability was associated significantly stronger with mixed anxiety-depression than with pure anxiety and pure depression. Mixed anxiety-depression was overrepresented in women. CONCLUSIONS: Both lines of investigation suggest that, in the elderly, a dimensional classification is more appropriate than a categorical classification of depression and generalised anxiety. Mixed anxiety-depression is a more severe form of psychopathology that is almost specific to women in this age group.

Aged↗
PubMed2005

Genotype-phenotype relationships in hepatocellular tumors from mice and man.

Experimentally induced liver tumors in mice harbor activating mutations in either Catnb (beta-catenin) or Ha-ras, according to the carcinogenic treatment. We have now investigated by microarray analysis the gene expression profiles in tumors of the two genotypes. In total, 364 genes or expressed sequences with aberrant expression relative to normal liver were identified, but only 30 of these demonstrated unidirectional changes in both tumor types. Several functional clusters were identified that involve changes in amino acid utilization and ammonia disposition in Catnb-mutated tumors as opposed to alterations in lipid and cholesterol metabolism in Ha-ras-mutated tumors. Moreover, several genes coding for inhibitory molecules within the Wnt-signaling pathway were upregulated in Catnb-mutated tumors, suggesting induction of a negative feedback loop, whereas Ha-ras-mutated tumors showed alterations in the expression of several genes functional in monomeric G-protein signaling. We conclude that mouse hepatoma cells adopt different evolutionary strategies that allow for their selective outgrowth under variable environmental conditions. Human hepatocellular cancers (HCC) lack RAS mutations but are frequently mutated in CTNNB1, the human Catnb ortholog. The set of genes aberrantly expressed in Catnb-mutated mouse tumors was used to screen, by expression profiling, for dysregulation of orthologous genes within a panel of 25 HCCs, of which 10 were CTNNB1-mutated. HCCs with activated beta-catenin displayed a gene expression profile that was similar to Catnb-mutated mouse tumors but distinct from the other human HCCs. In conclusion, expression fingerprints may be used for diagnostic purposes and potential new therapeutic intervention strategies. Supplementary material for this article can be found on the HEPATOLOGY website (http://www.interscience.wiley.com/jpages/0270-9139/suppmat/index/html).

Animals↗
PubMed2005

Dual phase and rate coding in hippocampal place cells: theoretical significance and relationship to entorhinal grid cells.

We review the ideas and data behind the hypothesis that hippocampal pyramidal cells encode information by their phase of firing relative to the theta rhythm of the EEG. Particular focus is given to the further hypothesis that variations in firing rate can encode information independently from that encoded by firing phase. We discuss possible explanation of the phase-precession effect in terms of interference between two independent oscillatory influences on the pyramidal cell membrane potential, and the extent to which firing phase reflects internal dynamics or external (environmental) variables. Finally, we propose a model of the firing of the recently discovered "grid cells" in entorhinal cortex as part of a path-integration system, in combination with place cells and head-direction cells.

Action Potentials↗
PubMed1991

Correlates of cortical bone mass among premenopausal and postmenopausal Japanese women.

Few studies have examined the multifactorial risk factors of bone mass in Asian populations. This cross-sectional study was designed to explore relationships between bone mass and environmental variables, including dietary and life-style factors, in Japanese women living in Japan. A total of 178 Japanese women completed the study: 89 premenopausal, ages 35-40, and 89 postmenopausal, ages 55-60. Midradial bone mineral content (MBMC) and bone mineral content per unit area, referred to as bone density (MBMD), were measured using single-photon absorptiometry. The major results of this investigation were the following: (1) The postmenopausal women differed significantly from the premenopausal women in having lower radial bone parameters, lower mean height, later age of menarche, and higher dietary intakes of carbohydrates, vegetables, and milk with a lower intake of caffeine. (2) Current protein intake was a positive correlate of MBMC in both groups. (3) Intake of vegetables (leafy green, yellow, orange, and white) and current milk intake were positively associated with MBMC in the postmenopausal women. (4) For the premenopausal women, irregular menstrual cycles was a negative correlate of MBMC, and for the postmenopausal women, years of menopause was negatively associated with MBMC and MBMD. Longitudinal studies are needed to establish more conclusively associations among diet, life-style, and reproductive history and bone mass of Japanese women.

Adult↗
PubMed1995

Frequency and characteristics of familial aggregation of Paget's disease of bone.

The cause of Paget's disease of bone (PDB) is unknown. In an attempt to ascertain the proportion of familial cases and evaluate the influence of genetic factors on the occurrence of the disease, a study was undertaken based on 35 PDB patients from our Unit. Their families were investigated, with the participation of a total of 128 first-degree relatives. Fourteen (40%) of these 35 index cases had at least one other first-degree relative affected with PDB and were defined as "familial." The remaining 21 (60%) were considered "sporadic." The frequency of males in the familial cases (79%) was significantly higher than among the sporadics (29%; p < or = 0.01). Mean age at diagnosis (63.1 +/- 12.6 vs. 71.3 +/- 8.7; p < or = 0.02), proportion of polyostotic cases (85.7% vs. 52.4%, p < or = 0.05), and mean number of involved bones per patient (4.36 +/- 2.50 vs. 2.33 +/- 1.93, p < or = 0.01) differ significantly in the familial and sporadic groups. The disease appears to be transmitted via both paternal and maternal sides, and pedigree analysis suggested an autosomal dominant inheritance or multifactorial mechanism. Apart from green-and-blue eye color, which was clearly associated with familial grouping (OR 6.25, 95% CI 1.15-37.16, p < or = 0.01), crude analysis on several genetically based traits and environmental variables revealed no other significant differences between the groups. The adjusted odds ratio estimated for green-and-blue eye color was 2.92 (95% CI 0.38-22.74).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗