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At least 91 records · Page 5Linked to original sources
PubMed1995

[Surgery of the abdominal aorta in the geriatric population: characteristics and results].

Refinement in surgical technique and perioperative management have considerably improved morbidity and mortality rates of carotid endarterectomy and abdominal aortic surgery, thus allowing a more aggressive approach in the treatment of carotid stenosis, abdominal aortic aneurysm and aorto-iliac occlusive disease in the elderly population (> 70 years). We review our experience with 446 consecutive patients undergoing surgery of the abdominal aorta: 295 patients (mean age 75.5 years) underwent resection of an abdominal aortic aneurysm (asymptomatic but > 5-6 cm, (n = 193), symptomatic (n = 67) or ruptured (n = 35). Additionally, 198 patients were treated surgically for aorto-iliac occlusive disease. A small group of 13 patients was deferred for combined operation, including prior myocardial revascularization and subsequent vascular surgery during the same anesthesia. The majority of patients had several cardiovascular risk factors and/or significant associated diseases. Mortality (< 30 days) was 3.5% following aorto-iliac bypass in the treatment of arterial occlusive disease and 8.4% after aneurysm repair (asymptomatic, symptomatic and ruptured aneurysms all included). 5-year survival was 74% and 64% after repair of aortic aneurysm and treatment of aorto-iliac occlusive disease respectively. On the basis of these results, we believe that major vascular surgery is still justified in elderly patients and can be achieved with reasonable mortality and morbidity. Main goals of the surgery, e.g. to relieve suffering, restore function so as to limit disability and dependency, and prolongation of life expectancy in a dignified and meaningful life-style, are realized the majority of operative survivors.

Aged↗
PubMedDate not supplied

Population characteristics of DNA fingerprints in humpback whales (Megaptera novaeangliae).

Humpback whales exhibit a remarkable social organization that is characterized by seasonal long-distance migration (> 10,000 km/year) between summer feeding grounds in high latitudes and winter calving and breeding grounds in tropical or near-tropical waters. All populations are currently considered endangered as a result of intensive commercial exploitation during the last 200 years. Using three hypervariable minisatellite DNA probes (33.15, 3'HVR, and M13) originally developed for studies of human genetic variation, we examined genetic variation within and among three regional subpopulations of humpback whales from the North Pacific and one from the North Atlantic oceans. Analysis of DNA extracted from skin tissues collected by biopsy darting from free-ranging whales revealed considerable variation in each subpopulation. The extent of this variation argues against a recent history of inbreeding among humpback whales as a result of nineteenth- and twentieth-century hunting. A canonical variate analysis suggested a relationship between scaled genetic distance, based on similarities of DNA fingerprints, and geographic distance (i.e., longitude of regional subpopulation). Significant categorical differences were found between the two oceanic populations using a multivariate analysis of variance (MANOVA) with a modification of the Mantel nonparametric permutation test. The relationship between DNA fingerprint similarities and geographic distance suggests that nuclear gene flow between regional subpopulations within the North Pacific is restricted by relatively low rates of migratory interchange between breeding grounds or assortative mating on common wintering grounds.

Animals↗
PubMed1989

Syndromology: an updated conceptual overview. I. Syndrome concepts, designations, and population characteristics.

Part I introduces the survey and presents a topic outline of the 10 parts that make up this overview of syndromology in this and the next four issues. The discussion in Part I considers various concepts and definitions of the term "syndrome" and different ways of applying syndrome designations. A population definition of a syndrome is then developed to show the meaning of common, less common, and occasional anomalies in various syndromes. The differences between a true multiple anomaly syndrome and a variant familial pattern are discussed. Finally, two types of weak recurrent patterns--chance patterns and association patterns--are explained.

Disease↗
PubMedDate not supplied

Population characteristics of Irish Helicobacter pylori isolates: a tRNA-associated locus.

BACKGROUND: A strain-variable transfer RNA-associated-locus (trl) was present in 50% of Irish Helicobacter pylori (H. pylori), isolates and did not correlate with the origin of the isolates. AIM: To associate a particular genotype or phenotype to trl status in H. pylori by further screening the isolates from the original study for the presence of known genotypic and phenotypic characteristics. METHODS: Forty two clinical isolates were screened for the presence of the cagA, vacA, iceA1 and vapD genes by Southern or DNA dot blot analysis. Western blot analysis was performed using antibodies to CagA, VacA, Lewis X (Le(x)) and Lewis Y (Le(y)). Plasmids were identified by the alkaline lysis method. RESULTS: The cagA gene was present in 29 (69%) of isolates screened and 21 (50%) produced the CagA protein. The vacA gene was detected in all of the isolates while VacA was expressed in 71.4%. The iceA1 and vapD loci were detected in 73.8% and 71.4% respectively. Le(x) was expressed in 42.9% and Le(y) in 38.1% of the isolates. Expression of both Lewis antigens was detected in 7.1% while in 30.9% neither antigen was detected. Plasmids were present in 47.6%. There was no association between the trl status of isolates and any of the above. There were no significant associations between the phenotypic and genotypic characteristics studied and peptic ulcer disease or non-ulcer dyspepsia. CONCLUSION: The strain-variable tRNA-associated locus is independent of the vacA/VacA, cagA/CagA, Lewis X, Lewis Y, iceA1, vapD and plasmid status in the population of Irish H. pylori isolates studied.

Bacterial Proteins↗
PubMed2003

Phenotypic population characteristics of the enterococci in wastewater and animal faeces: implications for the new European directive on the quality of bathing waters.

Faecal pollution of recreational bathing waters may derive from point sources of various wastewaters or from more diffuse sources such as run-off of agricultural wastes. The paper describes the application of population similarity studies to the enterococcal flora of various animal faeces and municipal wastewaters as a means of distinguishing human from animal faecal material. A simplified phenotypic testing technique (PhenePlate, PhP) was used to study the fermentation kinetics of eleven carbohydrates by all bacterial isolates. Enterococcal isolates (1,766) from six sources were investigated. Enterococcal population diversity (measured as Simpson's Diversity Index) in wastewater samples was high (mean D(i) = 0.95) compared with those of non-human faeces. The mean diversity of isolates in seabird faeces was 0.72, in sheep and donkey faeces 0.44, in dog faeces 0.42 and in cattle faeces 0.32. Analysis of population similarity coefficients demonstrated that faeces from sheep and cattle showed the greatest similarity (S(p) = 0.72). Sheep and cattle faeces demonstrated a low similarity to municipal wastewater samples. This would suggest that population similarity studies might be a useful tool for distinguishing the relative contributions of municipal wastewater and agricultural run-off to bathing water pollution. The PhP procedure identified a specific PhP type that appears to have high specificity to non-human faeces. It may, therefore, represent an important tool in source tracking. Additional phenotypic and genotypic analysis of PhP types that demonstrate a high degree of source specificity is required. The benefits and limitations of the use of population similarity studies to distinguish pollution sources are discussed in comparison with other source tracking approaches and the implications of these developments for future European Union legislation on the quality of bathing waters are discussed.

Animals↗
PubMed1984

Human corneal epithelial oxygen demand--population characteristics.

Observed differences in corneal response to contact lens wear have been attributed to variations in individual corneal oxygen requirements. Anterior corneal oxygen flux was measured on 100 human eyes using a polarographic oxygen sensor to determine if differences could be measured among subjects. A distribution in corneal epithelial oxygen use was found to exist in the population.

Adolescent↗
PubMed1995

Population characteristics of cyclodextrin complex stabilities in aqueous solution.

Binding constants (K11) of 1:1 complexes of alpha-cyclodextrin, beta-cyclodextrin, and gamma-cyclodextrin with many substrates (guests) were collected from published sources and subjected to statistical analysis. All systems refer to 25 +/- 5 degrees C and aqueous solution. The frequency distributions of log K11 are satisfactorily described by normal distributions with the following parameters (n = number of complexes, mu = population mean, sigma = population standard deviation): alpha-cyclodextrin, n = 663, mu = 2.11, sigma = 0.90; beta-cyclodextrin, n = 721, mu = 2.69, sigma = 0.89; gamma-cyclodextrin, n = 166, mu = 2.55, sigma = 0.93. Stabilities of pairs of cyclodextrin complexes with a common substrate are not precisely correlated, but they do not appear to be wholly independent quantities. The stabilities of alpha-cyclodextrin complexes are consistent with a recent interpretation of solvent effects on alpha-cyclodextrin complex stabilities.

Cyclodextrins↗
PubMedDate not supplied

Comprehensive geriatric assessment in the outpatient setting: population characteristics and factors influencing outcome.

The chronic diseases of old age reduce the "active life expectancy" of older persons and result in significant health care expenditures. Yet, among disabled persons, the degree of disability does not explain who actually accesses long-term care (LTC) services. Comprehensive geriatric assessment (CGA) has been proposed as the technology of geriatric medicine which will reduce both excess disability and health care costs. Outpatient CGA programs may be the ideal setting in which to study older disabled persons who are at risk for increasing their use of LTC services. A prospective study of our CGA population suggests that understanding the factors which influence outcome will be critical to designing interventions and improving outcome for this population. CGA patients suffer from a limited number of functionally disabling problems, each of which has a broad array of etiologies. Use of LTC services seems most closely tied to social factors, including the feelings of burden experienced by caregivers. Caregiver burden is a better predictor of service use than any measure of the older person's mental or physical health or functional abilities. Reducing health care costs including nursing facility placement will likely require interventions which reduce caregiver burden. Further definition of the problems seen in the CGA population and delineation of the factors influencing outcome will identify interventions to achieve the desired health care outcomes.

Aged↗
PubMed2003

The missing biomarker link: relationships between effects on the cellular energy allocation biomarker of toxicant-stressed Daphnia magna and corresponding population characteristics.

The cellular energy allocation (CEA) methodology was used to assess the adverse effects of toxic stress on the energy budget of test organisms. This biochemical assay is quantified by determining changes in the available energy reserves, Ea (total carbohydrate, protein, and lipid content) and the energy consumption, Ec (electron transport activity). The CEA methodology was fully explored by using neonates of Daphnia magna exposed for 96 h to six model toxicants (CdCl2, K2Cr2O7, tributyltin chloride, linear alkylbenzene sulfonic acid, sodium pentachlorophenolate, and 2,4-dichlorophenoxyacetic acid). To evaluate the ecological relevance of the CEA parameter, we compared the suborganismal responses with population-level parameters (obtained from 21-d life-table experiments) such as the intrinsic rate of natural increase (rm) and the mean total offspring per female. The observed reductions in CEA values were both the result of a decrease in Ea and an increase in Ec. From all individual CEA components analyzed, the lipid reserve criterion was the most sensitive endpoint studied. Both the CEA-based lowest-observed-adverse-effect concentration (LOAEC) values and the effective concentration of 10% (EC10) values were significantly (p < 0.05) and linearly correlated with the chronic (21-d) LOAEC and EC10 values based on growth, survival, and reproduction. This relationship demonstrates the usefulness of the methodology to predict long-term effects. Furthermore, significant (p < 0.0001) sigmoid relationships between the 96-h CEA value (expressed as percentage relative to the control) and population-level effects were observed.

Animals↗
PubMed1999

Health status and population characteristics of dogs and cats examined at private veterinary practices in the United States.

OBJECTIVE: To determine age, breed, sex, body condition score, and diet of dogs and cats examined at private veterinary practices in the United States during 1995, and estimate prevalences of the most common disorders for these animals. DESIGN: Cross-sectional study. ANIMALS: 31,484 dogs and 15,226 cats examined by veterinary practitioners at 52 private veterinary practices. PROCEDURE: Information on age, breed, sex, body condition score, diet, and assigned diagnostic codes were collected electronically from participating practices and transferred to a relational database. Prevalence estimates and frequencies for population description were generated using statistical software. RESULTS: Dental calculus and gingivitis were the most commonly reported disorders. About 7% of dogs and 10% of cats examined by practitioners during the study were considered healthy. Many conditions were common to both species (e.g., flea infestation, conjunctivitis, diarrhea, vomiting). Dogs were likely to be examined because of lameness, disk disease, lipoma, and allergic dermatitis. Cats were likely to be examined because of renal disease, cystitis, feline urologic syndrome, and inappetence. CLINICAL IMPLICATIONS: Results can be used by veterinary practitioners to better understand and anticipate health problems of importance in cats and dogs they examine and to better communicate with clients regarding the most prevalent disorders in cats and dogs.

Age Distribution↗
PubMed2003

Morphological and populational characteristics of hemocytes of Ornithodoros moubata nymphs during the ecdysial phase.

The ultrastructure and characteristics of hemocytes of argasid tick species, Ornithodoros moubata, during the ecdysdial phase are herein presented. Hemocyte classes/populations characterized based on their affinity with Giemsa stain and ultrastructural differences comprised the prohemocytes, nongranular cells (Nc), eosinophilic granular cells (Ec), basophilic granular cells (Bc), and unidentified cells. Significant changes/shift in the ratio of hemocyte classes/population was apparent in ticks before and after the ecdysial phase. The granule-scant basophilic granular cells (sBc) constituted the most abundant hemocyte population in the ecdysial phase. Nymphs in ecdysis showed increases in Nc and sBc and decrease in Ec, a phenomenon that was reversed in unengorged nymphs and adults ticks. The significant increase in total Bc population in ecdysis relative to nonengorged ticks clearly point to blastogenesis of Bc taking place during the ecdysial phase and Bc's important role in the process of tissue remodeling.

Animals↗
PubMed1999

Population characteristics of preproenkephalin mRNA-containing neurons in the globus pallidus of the rat.

Anatomical, neurochemical and electrophysiological evidence indicates the presence of multiple neuronal subpopulations within the rodent globus pallidus (GP). One subpopulation that has not been well characterized is GP neurons that express preproenkephalin mRNA (PPE+ cells). The present study seeks to further characterize GP subpopulations by determining whether the PPE+ GP neurons express parvalbumin immunoreactivity (PV-IR) and where their axons project by retrogradely labeling pallidal neurons with the tracer FluoroGold (FG). Using combined PV immunocytochemistry (ICC) and PPE mRNA in situ hybridization, we observed that PV-IR and PPE mRNA identify predominantly separate pallidal cell populations. Combined FG ICC and PPE mRNA in situ hybridization also revealed that this neuropeptide mRNA is more often found in FG-labeled pallidostriatal than pallidosubthalamic neurons. Our data support a growing body of evidence that suggests the GP is more heterogeneous than accounted for by current functional models of the basal ganglia.

Animals↗
PubMed1993

Dose proportionality and population characteristics of oral fadrozole hydrochloride, an aromatase inhibitor, in postmenopausal women.

The dose proportionality of the pharmacokinetics of fadrozole was investigated in 18 healthy postmenopausal women. Fadrozole hydrochloride was administered as 0.3-, 1.0-, and 2.0-mg oral doses continuously every 12 hr for 5 days each in a Latin square design. At steady state, the dose-normalized pharmacokinetic parameters AUC and Cmax were found to be independent of the dose. In addition, no statistically significant differences in tmax were detected. It was concluded that the pharmacokinetics of fadrozole were dose proportional in the projected therapeutic dose range. The relationship between oral clearance and the demographic factors, age, weight, and height, was assessed. Oral clearance was related to total body weight but not age or height. Prospective estimates of the population components of variance showed that intersubject variance accounted for 91.7% of the total random variance. Weight variance accounted for 36.1% of the intersubject variance.

Adult↗