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At least 145 records · Page 8Linked to original sources
PubMed2002

The impact of the changing marital structure on fertility of Hong Kong SAR (Special Administrative Region).

Hong Kong SAR has experienced an especially rapid fall in fertility over the course of just two decades. The total fertility rate (TFR) fell steadily from the replacement level (i.e. two children per woman) to 0.83 in 1999, which is the lowest in the world. (United Nations Population Division. Replacement migration: is it a solution to declining and ageing populations? United Nations, New York, 2000.) An important question is whether the dramatic decline in the TFR results from a decline in the fertility of married women or from changes in the proportion ever married. Are married women having fewer children, or are there simply fewer married women of prime childbearing age? In this paper, the effects of the changing marital structure on the conventional TFR are identified so that the underlying trends in fertility can be assessed. The study shows that the large decline in the TFR between 1981 and 1999 was in great part distorted by tempo effects, distortions caused by changes in the timing of childbearing and the changing marital structure. Without the distortion induced by the decreasing proportion of women marrying in the prime childbearing years, the decline in fertility was essentially less significant over the 20-year period. A continuation in the downward trend in the proportion married is a strong probability in the light of marriage habits prevalent among the population. This will exert a continuing downward driving force on the TFR. Hong Kong will experience its fertility rate decline further in the short to medium term. The study investigates the effect of long-lasting below-replacement level fertility with a view to gaining some analytical insight into the situation should the population experience such a striking demographic process.

Adult↗
PubMed2006

Health-related quality of life in patients waiting for major joint replacement. A comparison between patients and population controls.

BACKGROUND: Several quality-of-life studies in patients awaiting major joint replacement have focused on the outcomes of surgery. Interest in examining patients on the elective waiting list has increased since the beginning of 2000. We assessed health-related quality of life (HRQoL) in patients waiting for total hip (THR) or knee (TKR) replacement in three Finnish hospitals, and compared patients' HRQoL with that of population controls. METHODS: A total of 133 patients awaiting major joint replacement due to osteoarthritis (OA) of the hip or knee joint were prospectively followed from the time the patient was placed on the waiting list to hospital admission. A sample of controls matched by age, gender, housing and home municipality was drawn from the computerised population register. HRQoL was measured by the generic 15D instrument. Differences between patients and the population controls were tested by the independent samples t-test and between the measurement points by the paired samples t-test. A linear regression model was used to explain the variance in the 15D score at admission. RESULTS: At baseline, 15D scores were significantly different between patients and the population controls. Compared with the population controls, patients were worse off on the dimensions of moving (P < 0.001), sleeping (P < 0.001), sexual activity (P < 0.001), vitality (P < 0.001), usual activities (P < 0.001) and discomfort and symptoms (P < 0.001). Further, psychological factors--depression (P < 0.001) and distress (P = 0.004)--were worse among patients than population controls. The patients showed statistically significantly improved average scores at admission on the dimensions of moving (P = 0.026), sleeping (P = 0.004) and discomfort and symptoms (P = 0.041), but not in the overall 15D score compared with the baseline. In patients, 15D score at baseline (P < 0.001) and body mass index (BMI) (P = 0.020) had an independent effect on patients' 15D score at hospital admission. CONCLUSION: Although patients' HRQoL did not deteriorate while waiting, a consistently worse HRQoL was observed in patients waiting for major joint replacement compared with population controls.

Adult↗
PubMed2002

The impact of stocking on the genetic integrity of Arctic charr (Salvelinus) populations from the Alpine region.

There is a long tradition of artificially stocking lakes and rivers with fish in the hope to increase the quality and amount of fish that can be harvested. The animals used for stocking often originate in distant hatcheries or hatcheries that breed fish from remote regions. This stocking practice could have effects on the genetic integrity of resident populations. We have analysed here a case of the influence of stocking on Alpine populations of the Arctic charr (usually included into Salvelinus alpinus, but revised to Salvelinus umbla Kottelat 1997) within a unique geographical and historical setting. The Königssee in the Bavarian Alps (Berchtesgaden) was heavily stocked several times during the last century. However, a sample of the ancestral Königssee population still exists in the Grünsee, which lies close to Königssee, but 1000 m higher. To trace the influence of stocking in Königssee we have analysed more than 300 individuals from 10 lake populations, including the source populations of the fish used for stocking. From these we have sequenced a part of the mitochodrial control region and have typed them at six microsatellite loci. The differential distribution of haplotypes, as well as assignment tests, show that the influence of stocking on the genetic integrity of the Königssee population has been negligible. However, our data reveal that in another lake included in our study (Starnberger See), the ancestral population was apparently replaced completely by the populations used for stocking. The major difference between the lakes is the relative preservation of ecological integrity. Königssee was ecologically stable in the past, whereas Starnberger See was heavily polluted at one point, with charr approaching extinction. Interestingly, in a lake neighbouring Starnberger See, the Ammersee, which was also subject to strong pollution but not stocked, the ancestral population has recovered. Our data suggest that the practice of artificial stocking should be reconsidered, or at least monitored for effectiveness.

Animals↗
PubMed2003

Continuous renal replacement therapy in acute renal failure.

The management of acute renal failure in the critically ill patient is extremely variable and there are no published standards for the provision of renal replacement therapy in this population. Continuous renal replacement therapy seems to be the treatment of choice because of its superior metabolic and hemodynamic control. There is better organ protection by continuous treatment but no evidence for better survival or renal recovery due to continuous treatment. The debate about optimal membrane as well as about optimal dialysis dose is ongoing. An effluent flow rate of at least 35 ml/kg/h as well as lower BUN level at treatment initiation seem to be necessary to provide better survival rate. Peritoneal dialysis is a less suitable option in continuous renal replacement of the adult intensive care patient but hybrid methods such as extended daily dialysis and sustained low efficient daily dialysis need consideration with respect to continuous hemofiltration/dialysis.

Acute Kidney Injury↗
PubMed1983

Medtronic-Hall valve replacement in a Third World population group.

In a twenty-month period, 396 Medtronic-Hall valves were inserted in 341 patients belonging to a Third World population group. Approximately 20% of the patients were given anticoagulants. The total follow-up period was 353 patient years (mean 13 months per patient). Late valve-related mortality was 3.6% patient years (excluding ring leaks) with a valve failure rate (VFR) of 4.0%/patient year. The incidence of thromboembolic complications was 6.8%/patient year while valve thrombosis occurred in 7 patients (2.0%/patient year). Hemolysis was generally subclinical, but 2 patients without ring leaks required transfusion. The initial late results compare favorably with those of St. Jude Medical valve replacement in a similar population group. The supreme test for any substitute heart valve is its successful application in a third world population group because its inadequacies are highlighted by an increased VFR and morbidity.

Adolescent↗
PubMed2006

Hormone replacement therapy and cataract: a population-based case-control study.

PURPOSE: Laboratory studies have suggested that hormone replacement therapy (HRT) may protect against the development of cataract, but epidemiological studies in humans have thus far been inconclusive. The aim of this study was to assess the association between hormone replacement therapy and cataract. METHODS: Population-based case-control study using data from the General Practice Research Database in the UK. Participants were 10 000 women aged 45 years and over with diagnosed cataract and 10 000 controls matched on age, general practice, and calendar period. RESULTS: The crude odds ratio for the association between cataract and ever-use of oestrogen-only hormone replacement therapy was 1.13 (95% CI 0.99-1.29). This reduced to 0.81 (95% CI 0.71-0.94) after adjustment for consultation rate. Similarly, the crude odds ratio for the association between cataract and ever-use of a formulation containing oestrogen and progestogen was 1.18 (95% CI 1.01-1.39), reducing to 0.86 (95% CI 0.72-1.02) after adjustment for consultation rate. CONCLUSIONS: Oestrogen-only and oestrogen-progestogen hormone replacement therapies are associated with a small reduced risk of cataract. This data adds to the growing body of evidence on the effects of HRT on health. All potential benefits and risks of this therapy should be taken into account when considering its use.

Aged↗
PubMed1998

Reutilization of trigeminal motoneurons during amphibian metamorphosis.

Indirect evidence suggests that trigeminal motoneurons (Vmns) in Rana pipiens innervate distinct myofiber populations in tadpoles and adult frogs. Redeployment occurs when the larval myofibers die and are replaced during metamorphosis. To directly test this hypothesis, DiI was injected into the larval muscle and Fast Blue into the replacement myofiber population. Over 95% of the Vmns contained both tracers, providing support for the innervation of sequential targets by the same motoneurons.

Animals↗
PubMed2003

[The role of hormone replacement therapy in the treatment of women with complicated chronic renal failure].

Patients with chronic renal failure (CRF) show an increased mortality and morbidity from cardiovascular disease. Women with CRF are also at high risk of accelerated bone loss and fracture because of complications such as renal osteodystrophy and many endocrine disturbances leading to premature menopause and estrogen deficiency. Hormone replacement therapy (HRT) has been known to have beneficial effects on various atherosclerotic parameters in population of postmenopausal women and its role in primary prevention of coronary artery disease has been proved in many studies. In general population estrogen replacement therapy has also been used as an effective form of treatment in women suffering from bone loss as well as a form of prevention of osteoporosis. Until now, the role of estrogen replacement therapy in the treatment of complications of end-stage renal disease in female patients has not been fully elucidated and the use of hormone replacement therapy needs to be carefully analysed in each individual case taking into account all risks and benefits.

Cardiovascular Diseases↗
PubMed2006

Evidence for tetracycline resistance determinant tet(M) allele replacement in a Streptococcus pneumoniae population of limited geographical origin.

A collection of 185 Streptococcus pneumoniae isolates was tested for their susceptibility to antipneumococcal drugs, with a focus on the distribution of tetracycline resistance determinants tet(M) and tet(O). Resistance patterns were compared with established correlates of multidrug resistance, and tetracycline-resistant isolates were tested for clonality and allelic variation within tet(M). Resistance to tetracyclines, penicillins and macrolides were all strongly related to multidrug resistance. Over one-quarter of the strains were tetracycline resistant, all via the tet(M)-mediated mechanism. Restriction fragment length polymorphism analysis revealed a high degree of allelic variation within tet(M) and gave evidence of a clonal and horizontal spread of selected alleles. A tet(M) variant that emerged with the onset of epidemic multidrug-resistant strains was replacing old alleles in the population.

Alleles↗
PubMed2005

Patterns of hormone replacement therapy in a population-based cohort of postmenopausal German women. Changes after HERS II and WHI.

In July 2002, data from the Women's Health Initiative (WHI) trial provided strong evidence for an increased risk of cardiovascular disease with use of combined estrogen plus progestogen in postmenopausal women. These unexpected results triggered a large and ongoing discussion about the role of hormone replacement therapy (HRT). We investigated the frequency of HRT before and after the publications of the WHI trial and the Heart and Estrogen/Progestin Replacement Study II (HERS II) in a population-based random sample of German women aged 45 - 65 years. A total of 8380 women completed a questionnaire on menopausal status, hysterectomy and HRT. 75 % were postmenopausal. Mean age was 56.1 years; mean age of natural menopause 49.9 years; mean duration of postmenopause was 11 years; 27 % of the women had undergone hysterectomy. The percentage of current HRT users dropped by 16 % (35.4 % to 29.8 %, p = 0.004), past users increased from 19.8 % to 23.5 % (p = 0.03). Among current HRT users, the share of combined conjugated estrogen/progestogen decreased by 41 % (p = 0.008). We observed a decreased prevalence of HRT among German women 7 months after publication of the HERS II and WHI results. The decline was, however less pronounced than reported from other countries. The use of conjugated estrogen/gestagen combinations declined disproportionately compared to other formulations.

Aged↗
PubMedDate not supplied

Development of CD4 and CD8 single positive T cells in human thymus organ culture: IL-7 promotes human T cell production by supporting immature T cells.

This paper describes novel model systems to study the development of human T cells. Fragments of neonatal human thymus (HUNT) can be cultured in vitro; the initial majority population of CD4, CD8 double-positive (DP) thymocytes is not maintained in organ culture. These cells are rapidly replaced by populations of CD4 or CD8 single-positive (SP) T cells. In addition, allogeneic thymic chimeras can be established by the addition of human cord blood (HUCB) mononuclear cells as a source of T progenitor cells to the organ cultures. Culture results in the acquisition of a mature SP T cell phenotype by the donor cells similar to that found when HUCB is allowed to develop in xenogeneic murine scid/scid fetal thymus organ culture. The number of immature and mature T cells produced by organ cultures can be differentially increased by the addition of exogenous IL-7, stem cell growth factor, IL-1, or GM-CSF. Anti-IL-7 antibody inhibits T cell production. Taken together, the results suggest that human T cell development occurs in these in vitro systems in a similar manner, regardless of the species origin of the thymic stromal cells in the culture, and that exogenous cytokines can be used to expand subpopulations of developing T cells.

Animals↗
PubMed1990

Diagnostic thyroid procedures and corresponding radiation doses in Manitoba: 1981-1985.

Data on nuclear medicine thyroid examinations performed in Manitoba (population 1 million) from 1981-1985 were collected, with more detailed demographic data obtained on 1,100 consecutive patients between June 1987 and January 1988. An average of 2,081 patients were examined per year, 81% female and 19% male, representing 8.4% of all nuclear medicine procedures. Typical administered activity and associated HE per patient were 238.0 MBq and 1.5 mSv for 99mTc, 7.4 MBq and 1.2 mSv for 123I, and 0.33 MBq and 3.9 mSv for 131I. Based on NCRP risk estimates with explicit corrections for age, sex, and radionuclide used, it is estimated that the rate of thyroid cancer induction is unlikely to exceed 0.56 y-1, of which about 10% would be fatal. This estimate is about a factor of 4 less than that generated using more generally applicable radiation protection risk estimates averaged over both sexes and all ages in the general population. The replacement of 131I with the present mix of radiotracers used for thyroid evaluation has resulted in a reduction of the estimated population detriment by a factor of 3.6.

Adolescent↗
PubMed1977

[Experience with the abolition of use of tetanus antiserum following trauma].

For the first time in the USSR, as a result of all-around analysis of the problems connected with tetanus prophylaxis under conditions of the Arkhangelsk region the authors conducted a trial on the suspension of the use of antitetanus serum in trauma. Besides the elimination of the population allergization, replacement of the antitetanus serum with the toxioid facilitated the emergency prophylaxis of tetanus, created prerequisites for the immunity maintenance at the protective level in the population, and served as the necessary stage along the route of further improvement of emergency prophylaxis and elimination of tetanus.

Adolescent↗
PubMed2006

Coalescent processes when the distribution of offspring number among individuals is highly skewed.

We report a complex set of scaling relationships between mutation and reproduction in a simple model of a population. These follow from a consideration of patterns of genetic diversity in a sample of DNA sequences. Five different possible limit processes, each with a different scaled mutation parameter, can be used to describe genetic diversity in a large population. Only one of these corresponds to the usual population genetic model, and the others make drastically different predictions about genetic diversity. The complexity arises because individuals can potentially have very many offspring. To the extent that this occurs in a given species, our results imply that inferences from genetic data made under the usual assumptions are likely to be wrong. Our results also uncover a fundamental difference between populations in which generations are overlapping and those in which generations are discrete. We choose one of the five limit processes that appears to be appropriate for some marine organisms and use a sample of genetic data from a population of Pacific oysters to infer the parameters of the model. The data suggest the presence of rare reproduction events in which approximately 8% of the population is replaced by the offspring of a single individual.

Animals↗
PubMed2001

Disparities in hormone replacement therapy use by socioeconomic status in a primary care population.

The use of hormone replacement therapy (HRT) is a controversial decision for many women, yet few studies have evaluated the socio-demographic, psychological, and behavioral correlates of HRT use. This cross-sectional, mailed survey evaluated the associations of socioeconomic status, preventive health behaviors, knowledge and perceptions about HRT-related risks and benefits with HRT use among 428 women 50-70 years old in Vermont. The overall prevalence of HRT use was 40%. Women of moderate to high income were three times more likely than those of low income to use HRT. HRT use was significantly higher among women whose physician had encouraged use (58%) than among those who received ambivalent recommendations from their physicians (20%). Hysterectomy, higher income, younger age, regular adherence to cervical cancer screening, and recommendation by a provider were significantly associated with HRT use in multivariate analyses. There were no differences in HRT use according to level of concern about heart disease, osteoporosis, or breast cancer. A recommendation by a health care provider is a powerful predictor of HRT use, but disparities in use exist by socioeconomic status. Future research should examine why lower income women are less likely to use HRT and whether the discrepancy is due to inconsistent recommendations by health care providers.

Aged↗