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At least 1,009 records · Page 56Linked to original sources
PubMed1998

The familial adenomatous polyposis region exhibits many different haplotypes.

In the present study, we used five different polymorphic markers to construct the haplotype at the adenomatous polyposis coli (APC) locus in families with familial adenomatous polyposis (FAP) and in the normal Italian population. Non-ambiguous haplotypes were reconstructed from 246 normal chromosomes and 65 FAP chromosomes. In the control population, the four polymorphisms intragenic to APC gave rise to 16 haplotypes, the most common of which (II and XV) accounted for over 50% of all chromosomes. In FAP patients, 13 haplotypes were found but their distribution was not statistically different from normal subjects. Eighty complete chromosomal haplotypes (many fewer than the theoretical maximum of 208) for the five polymorphic sites assayed were observed in the control population, 35 being found in the FAP patients. We compared the distribution of these haplotypes within the two groups; no statistically significant differences between normal and FAP chromosomes were found. The elevated heterogeneity of FAP chromosomes was clearly confirmed by the observation that 19 patients who carried one or other of the two most common APC mutations (nt 3183 and nt 3927) showed 18 different haplotypes. On the basis of these results, we were not able to identify a founder FAP chromosome. Various mechanisms are presented to explain this observation.

Adenomatous Polyposis Coli↗
PubMed2001

Sequence variations in the NDUFA1 gene encoding a subunit of complex I of the respiratory chain.

NDUFA1 is one of the 36 nuclear genes encoding subunits of the mitochondrial complex I involved in the respiratory chain. The human NDUFA1 has been cloned, completely sequenced and mapped to Xq24. In the present study, we searched for sequence variations in NDUFA1 as causative defects in complex I deficiency using genomic DNA of 152 patients with various clinical phenotypes. The patient sample consisted of 54 patients (46 male and 8 female) with Leber heriditary optic neuropathy (LHON) from 48 unrelated families from Germany and 98 patients (72 male and 26 female) with biochemically proven complex I deficiency including Leigh syndrome. Patient DNA was used to amplify all three exons, including the exon/intron boundaries and the promoter region of NDUFA1 for heteroduplex analysis and direct sequencing. In the 152 patients tested, no mutation was found that could be related to any of the disease phenotypes included. However, three single-nucleotide polymorphisms (SNPs) located in the promoter region (SNP G/C at nt -71 and SNP T/C at nt -189) and in intron 1 (SNP T/G nt 1454) were discovered. Allele frequencies of the SNPs were estimated in a German and Estonian control population and compared to complex I-deficient patients. There was no significant difference between the control population, the LHON patients, or the severely affected patients with complex I deficiency, excluding an association of the polymorphisms with the diseases. Our results suggest that mutations in NDUFA1 do not cause the gender difference observed in clinically severe and complex phenotypes with complex I deficiency.

Alleles↗
PubMed2004

Atherosclerosis, vascular amyloidosis and brain hypoperfusion in the pathogenesis of sporadic Alzheimer's disease.

We postulate that severe atherosclerotic occlusion of the circle of Willis and leptomeningeal arteries is an important factor in the pathogenesis of some sporadic Alzheimer's disease (AD) cases. These arterial stenoses are complicated by an overwhelming amyloid accumulation in the walls of leptomeningeal and cortical arteries resulting in a significant decrease in perfusion pressure and consequent ischemia/hypoxia of the brain tissue. We also propose that the distal areas of the white matter (WM) will be the first affected by a lack of oxygen and nutrients. Our hypotheses are supported by the following observations: (1) the number of stenoses is more frequent in AD than in the control population (p = 0.008); (2) the average index of occlusion is greater in AD than in the control group (p < 0.00001); (3) the index of stenosis and the total number of stenoses per case are positively correlated (R = 0.67); (4) the index of stenosis correlates with the neuropathological lesions of AD and with the MMSE psychometric test; (5) the number and degree of atherosclerosis of the anterior, middle and posterior cerebral arteries is more severe in cases of AD than in the control population; (6) atherosclerosis severity is apparently associated with the severity of the vascular amyloidosis; (7) the WM rarefaction correlates with the severity of the atherosclerosis and vascular amyloidosis; (8) the total cell count and microvessel count in the areas of WM rarefaction correlate with the neuropathological lesions of AD and with the MMSE score. Our data strongly suggest that severe hemodynamic disturbances contribute to sporadic AD and support the numerous observations indicating cardiovascular system participation in the pathogenesis of these dementias.

Alzheimer Disease↗
PubMed1997

Fractional excretion of magnesium in normal subjects and in patients with hypomagnesemia.

The aim of our study was the determination of fractional excretion of magnesium (FEMg++) in both normal subjects and hypomagnesemic patients. 142 subjects aged 26-72 years, recruited from our lipid clinic (control population) and 74 hypomagnesemic patients, aged 36-75 years, were studied. The mean FEMg++ in the control population was 1.8 per cent (range, 0.5-4 per cent). FEMg++ was not correlated with either serum magnesium or with serum creatinine. The mean FEMg++ in patients with hypomagnesemia of extrarenal origin was 1.4 per cent (range, 0.5-2.7 per cent), while the mean FEMg++ in hypomagnesemic patients in whom renal magnesium loss was the main etiologic factor for the pathogenesis of hypomagnesemia was 15 per cent (range, 4-48 per cent). In both groups of hypomagnesemic patients FEMg++ was positively correlated with the urinary magnesium to creatinine molar ratio, but was not correlated with serum magnesium or creatinine levels. FEMg++ could better distinguish the two groups of hypomagnesemic patients than the urinary magnesium to creatinine molar ratio. Hypomagnesemic patients exhibited a cluster of other acid-base and electrolyte abnormalities, mainly respiratory alkalosis, hypokalemia, hypophosphatemia, and hypocalcemia. In conclusion, in hypomagnesemic patients with normal renal function FEMg++ is a very useful tool for the diagnostic approach of hypomagnesemia. A value more than 4 per cent is indicative of inappropriate magnesium loss.

Adult↗
PubMed2003

Hair and toenail arsenic concentrations of residents living in areas with high environmental arsenic concentrations.

Surface soil and groundwater in Australia have been found to contain high concentrations of arsenic. The relative importance of long-term human exposure to these sources has not been established. Several studies have investigated long-term exposure to environmental arsenic concentrations using hair and toenails as the measure of exposure. Few have compared the difference in these measures of environmental sources of exposure. In this study we aimed to investigate risk factors for elevated hair and toenail arsenic concentrations in populations exposed to a range of environmental arsenic concentrations in both drinking water and soil as well as in a control population with low arsenic concentrations in both drinking water and soil. In this study, we recruited 153 participants from areas with elevated arsenic concentrations in drinking water and residential soil, as well as a control population with no anticipated arsenic exposures. The median drinking water arsenic concentrations in the exposed population were 43.8 micro g/L (range, 16.0-73 micro g/L) and median soil arsenic concentrations were 92.0 mg/kg (range, 9.1-9,900 mg/kg). In the control group, the median drinking water arsenic concentration was below the limit of detection, and the median soil arsenic concentration was 3.3 mg/kg. Participants were categorized based on household drinking water and residential soil arsenic concentrations. The geometric mean hair arsenic concentrations were 5.52 mg/kg for the drinking water exposure group and 3.31 mg/kg for the soil exposure group. The geometric mean toenail arsenic concentrations were 21.7 mg/kg for the drinking water exposure group and 32.1 mg/kg for the high-soil exposure group. Toenail arsenic concentrations were more strongly correlated with both drinking water and soil arsenic concentrations; however, there is a strong likelihood of significant external contamination. Measures of residential exposure were better predictors of hair and toenail arsenic concentrations than were local environmental concentrations.

Adult↗
PubMed1979

Reproductive adaptation in Drosophila exposed to oxygen-enriched atmospheres.

Ten successive generations of a Drosophila melanogaster population were exposed to an atmospheric mix of 50% oxygen/50% nitrogen at standard pressure. This atmospheric mix has been shown to be toxic to this species and causes significantly shortened life span. By the fifth generation, survivorship and life span for the first 25-30 days were identical to control populations and total life span was shorter by only a few days. Egg-laying rates were stable in the experimental populations but below those of the controls. Hatching success was identical between experimental and control populations. Even though the egg-laying rates were lower in 50% oxygen, it was concluded that the population had adapted and could maintain a stable population in these conditions. The near-normal life spans, normal hatching rates, and overall population stability, exhibited following five generations of adaptation, were considered sufficient to allow continued reproduction in spite of a reduced egg-laying rate.

Adaptation, Biological↗
PubMed1995

Stroke in China, 1986 through 1990.

BACKGROUND AND PURPOSE: Incidence of stroke varies markedly in different world populations. In seven Chinese cities, the effect of a program of risk factor modification on the incidence and mortality of stroke was studied and compared with a control population. This article describes the incidence of stroke in the control populations for the years 1986 through 1990. METHODS: Incidence (first-ever strokes only) for 1986 was obtained by door-to-door interview with heads of households with subsequent verification on examination by a neurologist and review of medical and/or hospital records. In subsequent years, cases were ascertained with a three-tier monitoring system: by community health workers, local medical centers, and the Beijing Neurosurgical Institute. RESULTS: Average annual age-adjusted incidence per 100,000 was 215.6 (261.5 for males, 174.5 for females; P < .001). There was a significant drop in the total number of cases from 137 in 1986 to 106 in 1990, but the age-adjusted rate showed a significant drop for males only (322.3 to 182.5, P < .001). Marked differences in average annual age-adjusted rates existed among the seven cities, from 486.4 for Harbin to 80.9 for Shanghai. This difference in rate among cities was found for both sexes but was more pronounced in males. CONCLUSIONS: The stroke incidence rates in China, like those in Japan, are among the higher ones in the world. In recent years, there has been an apparent decline in stroke incidence. Marked differences in rates were found between males and females with decline in incidence occurring almost exclusively in males. There were also marked differences in stroke incidence among the cities studied. These differences may result in part from differences in diet, alcohol and cigarette consumption, or prevalence of hypertension.

Adolescent↗
PubMed1994

Phase I trial of interferon gamma to potentiate cyclosporine-induced graft-versus-host disease in women undergoing autologous bone marrow transplantation for breast cancer.

PURPOSE: We investigated if interferon gamma (IFN-gamma) could augment cyclosporine (CSA)-induced graft-versus-host disease (GVHD) following autologous bone marrow transplant in women with metastatic breast cancer and defined the toxicities of this therapy. PATIENTS AND METHODS: Thirty-six women with advanced breast cancer were treated with CSA 2.5 mg/kg daily for 28 days and IFN-gamma 0.025 mg/m2 subcutaneously (SC) every other day, days 7 to 28 following autologous bone marrow transplantation and monitored for induction and severity of GVHD and toxicity of therapy. RESULTS: GVHD was induced in 56% of patients. The severity of GVHD was greater than in a historic control population treated with CSA alone. Stage III rash was seen in 36% of patients, compared with 3% in the historic control population. Fourteen of 36 patients required therapy with topical corticosteroids and two of 36 required systemic treatment. Only three of 31 historic controls needed topical corticosteroids and no patient was treated systemically. There was no severe visceral GVHD. Hematopoietic recovery was not delayed. There were three toxic deaths. CONCLUSION: CSA-induced GVHD can be safely augmented by IFN-gamma in women treated with high-dose alkylating agents and autologous bone marrow transplantation. There is little evidence of increased toxicity. Evidence of antitumor efficacy awaits further investigation.

Adult↗
PubMed1981

Clinical trials:randomization before consent.

Conventional blind randomized trials involve obtaining consent for treatment prior to randomization into control or treatment groups. When the trial is of necessity an open one, obtaining consent to treatment and then assigning the patient to a control group may lead to undesirable consequences. When consent is required prior to randomization, inability to obtain it diminishes both control and treatment numbers. Obtaining consent after randomization enhances the power of the study since refusal affects only treatment numbers thus making more efficient use of patient material. We propose to analyze the outcome of patients allocated to treatment, but refusing experimental therapy, as a separate group. Comparison of this group with the control population will permit validation of the efficacy of the randomization process and allow testing of the hypothesis that refusers of consent react the same as the control population. If no difference occurs we propose that the refuser and control groups be combined and compared with those patients who receive experimental treatment.

Clinical Trials as Topic↗
PubMed2006

Effects of prolonged wrist flexion on transmission of sensory information in carpal tunnel syndrome.

UNLABELLED: Carpal tunnel syndrome presents a constellation of symptoms which include discomfort (eg, pain, paraesthesia) and diminished sense of touch. This exploratory study simultaneously measured changes in tactile threshold and discomfort ratings during prolonged wrist flexion in symptomatic patients from a rehabilitation clinic and from a control population. Prolonged (15 min) wrist flexion significantly increased tactile threshold and discomfort ratings above baseline levels in both symptomatic and control populations. Sixty-two percent of the symptomatic sample was found to have abnormal conduction latency. Tactile threshold in symptomatic subjects with normal conduction latency (n = 13) did not differ significantly from control subjects (n = 36) at baseline but showed significant elevation during wrist flexion. In contrast, subjects with abnormal conduction latency (n = 21) exhibited significant elevation relative to control subjects at baseline and throughout wrist flexion as well as a slower recovery after flexion. Conduction latency correlated with baseline (r = .52, P < .0001) and 15-min (r = .67, P < .0001) tactile threshold for the entire subject population, as well as 15-min threshold (r = .53, P = .013) for the subpopulation with abnormal conduction latency. At 2.5 min after flexion, correlation was significant for whole (r = .64, P < .0001) and abnormal conduction latency (r = .58, P = .0063) samples. Regression slope of tactile threshold versus conduction latency was significantly greater than zero and did not differ significantly from linearity. The study demonstrates that increases in mechanosensory threshold and discomfort ratings during prolonged wrist flexion are more profound (and recovery less rapid) in patients with electrophysiologic evidence of injury. PERSPECTIVE: This study demonstrates a provocative procedure that enhances the symptoms of carpal tunnel syndrome. This measure may help clinicians discriminate median nerve compression from other types of peripheral nerve injury and help researchers investigate the impact of mechanical stress, tissue compression, and vascular stasis on compression-related neuropathy.

Adolescent↗
PubMed1977

Palmar flexion creases and dermatoglyphics among diabetic patients.

Palmar dermatoglyphics and flexion creases of 108 male and 65 female patients diagnosed as having diabetes mellitus have been analysed. The control population consists of 536 males and 234 females from the same population. Palmar flexion creases were analysed according to the method suggested by Bali and Chaube ('71). The flexion creases of diabetic patients and the control population are significantly different. The differences between main line formulae in diabetes and controls are significant among males. The differences between C-line types of patients and controls are significant among both sexes. Axial triradii are significant among female patients and controls. The patterns in the interdigital areas IV and II are significantly lower among male and female patients respectively from their controls.

Dermatoglyphics↗
PubMed1998

Modern life' in the epidemiology of inflammatory bowel disease: a case-control study with special emphasis on nutritional factors.

OBJECTIVE: The rising incidence of inflammatory bowel disease (IBD) since the Second World War coincides with profound changes of the dietary pattern. The aim of the study was to investigate the possible pathogenic role of some characteristic 'modern life' dietary factors in IBD. DESIGN: Case-control, studying risk factors in recently diagnosed cases, 290 with Crohn's disease and 398 with ulcerative colitis, compared with 616 population controls. Smoking, age, gender and education were taken into account by using logistic regression analysis. SETTING: Hospital cases and population controls. INTERVENTIONS: Questionnaires. MAIN OUTCOME MEASURES: Logistic regression-derived odds ratios. RESULTS: A positive association with cola drinks [OR: 2.2 (95% CI 1.5-3.1)], chewing gum [OR: 1.5 (95% CI: 1.1-2.1)] and chocolate consumption [OR: 2.5 (95% CI: 1.8-3.5)] and a negative association with citrus fruit consumption [OR: 0.5 (95% CI 0.3-0.7)] and the development of Crohn's disease were found. Consumption of cola drinks [OR: 1.6 (95% CI 1.1-2.3)] and chocolate consumption [OR: 2.5 (95% CI 1.8-3.5)] were positively associated with developing ulcerative colitis. There was a negative association between the intake of citrus fruits [OR: 0.5 (95% CI 0.4-0.8)] and 'having a stuffed pet' for a period longer than 5 years [OR: 0.6 (95% CI 0.4-0.9)] and developing the disorder. No association with the frequency of tooth brushing and developing IBD was found. CONCLUSION: All the nutritional items mentioned may be true risk factors or they just might be the expression of a modern life-style also involving other risk factors for the development of IBD which at the present are still unknown.

Adult↗
PubMed1995

Weak extremely-low-frequency magnetic fields and regeneration in the planarian Dugesia tigrina.

Extremely-low-frequency (ELF), low-intensity magnetic fields have been shown to influence cell signaling processes in a variety of systems, both in vivo and in vitro. Similar effects have been demonstrated for nervous system development and neurite outgrowth. We report that regeneration in planaria, which incorporates many of these processes, is also affected by ELF magnetic fields. The rate of cephalic regeneration, reflected by the mean regeneration time (MRT), for planaria populations regenerating under continuous exposure to combined DC (78.4 muT) and AC (60.0 Hz at 10.0 muTpeak) magnetic fields applied in parallel was found to be significantly delayed (P << 0.001) by 48 +/- 1 h relative to two different types of control populations (MRT approximately 140 +/- 12 h). One control population was exposed to only the AC component of this field combination, while the other experienced only the ambient geomagnetic field. All measurements were conducted in a low-gradient, low-noise magnetics laboratory under well-maintained temperature conditions. This delay in regeneration was shown to be dependent on the planaria having a fixed orientation with respect to the magnetic field vectors. Results also indicate that this orientation-dependent transduction process does not result from Faraday induction but is consistent with a Ca2+ cyclotron resonance mechanism. Data interpretation also permits the tentative conclusion that the effect results from an inhibition of events at an early stage in the regeneration process before the onset of proliferation and differentiation.

Animals↗
PubMed1991

Remarks on population planning and control.

We investigate the use of control theory in population planning and show how the use of age at first birth, birth interval, and sex ratio as control variables leads to a practical, fault tolerant approach to population planning and control.

Age Factors↗
PubMed2003

Angiotensin converting enzyme gene polymorphism and myocardial infarction a large association and linkage study.

The DD genotype of the angiotensin converting enzyme (ACE) polymorphism has been associated with myocardial infarction (MI). However, sample sizes of many case-control studies showing positive association were small and data were inconsistent. Furthermore, no family-based study is available. In a case-control study frequencies of the ACE genotypes were compared in 1319 unrelated patients with previous MI before 60 years of age (616 from the MONICA Augsburg region and 703 from rehabilitation centers in south Germany) and in 2381 population controls from the MONICA Augsburg study region). Furthermore, linkage and association of the ACE I/D polymorphism with MI were tested in 246 informative families using the sib-transmission/disequilibrium test (S-TDT).Overall, no excess of the D allele was found in MI patients (frequency 0.53 versus 0.57 in the general population; P=0.2). The ACE DD genotype was even slightly less frequent in groups with MI compared to the general population controls (0.26 versus 0.33 in women and 0.28 versus 0.33 in men). Similar results were also obtained in 247 men with low cardiovascular risk. In the family-based study, the frequency of the D allele was not different in siblings with or without previous MI (0.53 versus 0.50, respectively; S-TDT P=0.15) indicating no linkage or association of the D allele with MI. In a case-control study of MI patients and controls from the general population as well as a family study neither association nor linkage of the ACE D allele with MI was detected despite sample sizes that were among the largest samples studied so far.

Case-Control Studies↗
PubMed2001

Smooth muscle inclusion bodies in slow transit constipation.

Slow transit constipation (STC) is a disorder of intestinal motility of unknown aetiology. Myopathies, including those characterized by the finding of inclusion bodies, have been described in enteric disorders. Amphophilic inclusion bodies have been reported in the muscularis externa of the colon of STC patients. This study formally tested the hypothesis that these represent a primary muscle disorder, specific to STC. In a systematic, blinded, dual observer qualitative and quantitative analysis, colonic and ileal tissue from patients with STC (n=36) were compared with selected control populations: total colonic aganglionosis (n=10), Chagas' disease (n=6), isolated rectal evacuation disorders (n=6), and a control population of a range of ages (n=80). All sections were stained with haematoxylin and eosin and periodic acid Schiff. Further immunostains were used in an attempt to determine inclusion body composition. Round or ovoid (4-22 microm diameter) amphophilic inclusions increased in number in normal subjects with age. Inclusions were more frequent in idiopathic STC than in age-matched controls or rectal evacuation disorders [ileum (33% vs. 9%), ascending (50% vs. 19%, p<0.05), and sigmoid colon (43% vs. 20%)] and were very frequent in the sigmoid (71%) of patients with STC arising after pelvic surgery. The number of inclusions per unit area was significantly higher in patients with STC (p<0.001). Inclusions were found in all Chagas' patients, but not with aganglionosis. It was not possible to determine inclusion body composition, despite the use of a wide range of conventional and immunostains. This study demonstrates that inclusion body myopathy is identifiable in patients with STC and that it may arise secondary to denervation.

Adult↗
PubMed1982

Syphilis control in populations previously exposed to yaws.

Application of an epidemiologic strategy, involving repeated annual screening, public relations activities and treatment to selected groups, for syphilis control in four communities is described. The predictive value of the VDRL screening test was influenced by the titre of the test and the age and location of individuals on whom it was performed. The predictive value of 1:8 VDRL titres (for active syphilis) varied from zero in individuals over 50 years of age, in one community to 0.96 in individuals 10-29 years old in another. Reduction in transmission of infection was closely related to the degree of screening coverage of the community and adjacent communities with which intercourse occurred.

Adolescent↗