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PubMed1984

Evaluating upper arm anthropometric measurements.

Jelliffe's standards for evaluating measurements of mid-upper arm circumference, triceps skinfold thickness, and mid-upper arm muscle circumference of American adults were compared with percentile distributions developed from the first Health and Nutrition Examination Survey (NHANES I). These comparisons show that the standards poorly represent the adult U.S. population. Replacement of the standards with updated sex-specific values is not recommended, as (a) no single value for each arm parameter can be considered as "normal" for men or women of all ages and (b) the expression of arm measurements as percentages of standards is an inappropriate method of evaluation. Instead, measurements should be evaluated by comparison with age- and sex-specific percentile distributions developed from the NHANES I.

Adolescent↗
PubMed1997

Ross procedure with aortic root tailoring for aortic valve replacement in the pediatric population.

BACKGROUND: Aortic valve replacement with a pulmonary autograft (Ross procedure) is being applied more commonly in children. Although indications for this procedure have been expanded, the presence of a dilated aortic annulus has remained a relative contraindication. In this condition, the use of an undersized autograft in an enlarged aortic annulus may result in significant aortic regurgitation. METHODS: Among 68 children and young adults undergoing the Ross procedure, 15 (age range, 8 to 24 years) with severe aortic regurgitation or stenosis and an aortic annulus diameter that was at least 2 mm larger than the pulmonary annulus had aortic root tailoring. In this group, the diameter of the aortic annulus measured 26.6 +/- 1.3 mm (mean +/- standard error of the mean), whereas that of the pulmonary annulus was 22 +/- 0.9 mm. The mean annular difference was 4.6 +/- 0.7 mm (range, 2 to 12 mm). The aortic annulus was reduced by excising a triangular wedge of tissue posteriorly from the aortic valve annulus at the level of the commissure between the left and noncoronary cusps extending into the anterior leaflet of the mitral valve. The edges were reapproximated over a calibrated dilator to adjust the final size of the aortic annulus to 2 mm smaller than that of the pulmonary autograft. Circumferential felt strips were not used in any patient. RESULTS: All patients survived and morbidity was limited to one reoperation for bleeding. Doppler echocardiographic examination performed at discharge demonstrated that no patient had more than trace to 1+ aortic regurgitation and none had evidence of aortic stenosis. Over a mean follow-up period of 6.3 +/- 1.5 months (range, 1 to 16 months) there has been no late morbidity or mortality and no progression of aortic regurgitation. CONCLUSIONS: Aortic root tailoring further extends the use of the Ross procedure to patients with excessive aortic annular dilation while maintaining the potential for growth, which is particularly important in the pediatric population.

Adolescent↗
PubMed2006

Functional outcome of fracture neck of femur treated with total hip replacement versus bipolar arthroplasty in a South Asian population.

INTRODUCTION: Endoprosthetic replacement is a popular method of treatment for fracture neck of femur in the elderly. Unipolar, bipolar and total hip endoprosthesis are all used. The aim of this paper is to compare the functional results of bipolar arthroplasty with that of total hip arthroplasty in a South Asian population. MATERIALS AND METHODS: Sixty-one patients who underwent prosthetic replacement for fracture neck of femur between May 1997 and Dec 2002 were followed-up prospectively. Twenty-nine patients were treated with total hip replacement and thirty-two were treated with bipolar arthroplasty. At the time of the last follow-up, twenty-four patients had expired and seventeen could not be traced. The results in the remaining twenty are presented. RESULTS: The period of follow up ranged from 24 months to 90 months, with a mean of 58.5 months. The mean Harris Hip Score for the bipolar group was 86.93, and for the total hip group was 83.82. More than a third of our patient population died within 5 years of endoprosthetic replacement. CONCLUSION: The functional outcome is equally good whether bipolar or total hip replacement is used, in the elderly, in a South Asian population. More than a third of our patient population expired within 5 years of prosthetic replacement; therefore it may be wise to choose the less expensive treatment modality in resource poor countries.

Aged↗
PubMed1991

Replacement patterns of Ascaris lumbricoides populations in Filipino children.

The replacement patterns of Ascaris lumbricoides worm populations were investigated by complete deworming of 150 Filipino children (0-14 years old) from both urban and rural barangays and analyzing the age distribution of the 2,072 adult worms (939 males and 1,133 females) obtained, based on Seo's (1983) regression equation relating length to age. It was observed that most worm populations followed a periodic pattern of replenishment. This supports the general practice of periodic anthelminthic campaigns. However, there seems to be a tendency for moderate and heavy cases to follow a continuous replacement pattern as evidenced by shorter time intervals between generations and wider age ranges. The data suggest that periodic deworming schedules may not be appropriate in areas where cases are predominantly of higher intensity. In such situations, control and/or eradication can probably be achieved only if chemotherapy is applied more frequently and supplementary health education and environmental modification measures are provided.

Adolescent↗
PubMedDate not supplied

[Requirements for permanent replacements in certain population groups].

The analysis is presented of the results of epidemiological studies of 180 subjects of either sex aged 35-44 years from the standpoint of their needs for crowns and bridges. The proportion of subjects in need of prosthetic crowns was 30.55%, while 18.33% required bridges. The material was subjected to statistical analysis.

Adult↗
PubMed1976

Influence of instantaneous fertility decline to replacement level on population growth: an alternative model.

If age-specific birth rate mx of a stable population drop abruptly to mx/Ro, where Ro is the net reproduction rate, then, according to Keyfitz, the size of the ultimate stationary population relative to that at the beginning of the process is given by I = beoo(Ro - 1)/(rmuRo), where b and r are the birth rate and the rate of growth, respectively, of the stable population, eoo the life expectancy at birth, and mu the average age at childbirth in resulting stationary population. Noting that the decline in mx need not necessarily be uniform, investigation has veen carried out to examine the effect on I when fertility decline is more rapid at higher ages. In particular, the effect of the reduced age-specific rates such as mxe-rx (which also produces a stationary population) has been analyzed, and simplifications of the results carried out separately for three different models of the net maternity function. It has also been shown the when mx drops abruptly to some m* x, where the form of m*x need not be specified except for the restriction that the resulting population will be stationary, the value of the index can be approximately obtained from I* = beoo (1 - rmu/2), where mu is the average age at childbearing of theinitial stable population.

Birth Rate↗
PubMed2005

Renal replacement therapy among disadvantaged populations in Mexico: a report from the Jalisco Dialysis and Transplant Registry (REDTJAL).

BACKGROUND: End-stage renal disease represents a serious public health problem in Jalisco, Mexico. It is reported among the 10 leading causes of death, with an annual mortality rate of 12 deaths per 100,000 population. The state population is 6.3 million, and more than half do not have medical insurance. In this study, we report the population's access to renal replacement therapy (RRT). METHODS: Patients > or =15 years of age, who started RRT between January 1998 and December 2000 at social security or health secretariat medical facilities, were included. Nine facilities participated in the study. At the start of treatment, the patient's facility, age, gender, cause of renal failure, and initial treatment modality were registered. RESULTS: Within the study period, 2456 started RRT, 1767 (72%) at social security facilities and 687 (28%) at health secretariat facilities, for an annual incidence rate of 195 per million population (pmp). The main cause of renal failure was diabetes mellitus (51% of patients). There were significant differences between the 2 populations. Patients with social security were older (53.1 +/- 17 vs. 45.1 +/- 20 years, P= 0.001) and had more diabetes (54% vs. 42%, P= 0.001) than those without social security. They had higher acceptance (327 pmp vs. 99 pmp, P= 0.001) and prevalence rates (939 pmp vs. 166 pmp, P= 0.001) than patients without medical insurance. Dialysis use was similar in both populations. Eighty-five percent of patients were on continuous ambulatory peritoneal dialysis and 15% on hemodialysis. Kidney transplant rate was higher among insured patients (72 pmp vs. 7.5 pmp, P= 0.001). The number of dialysis programs and nephrologists that offered renal care also differed. There were 10 dialysis programs in social security and 3 in health secretariat facilities. Fourteen nephrologists looked after the insured population, whereas 5 cared for the uninsured (7.7 pmp vs. 2.1 pmp, P= 0.001). The latter had access to 8 hemodialysis stations compared with 34 for the insured population (3.4 pmp vs. 18.8 pmp, P= 0.001). CONCLUSIONS: Access to RRT is unequal in our state. Although it is universal for the insured population, it is severely restricted for the poor. Social and economical factors, as well as the limited number of understaffed, centralized dialysis facilities, could explain these differences.

Female↗
PubMed1992

Immigrant's ages and the structure of stationary populations with below-replacement fertility.

A sustained regime of low fertility plus immigration yields an unusual kind of stationary population. The author demonstrates that all stationary populations have a common structure, and that the familiar replacement-level fertility population is the youngest among the many stationary populations corresponding to a particular life table. This finding has important consequences for policy because although fertility increase and immigration are equally effective at halting population decline, immigration is inferior as a means of rejuvenating low-fertility populations. In fact, an immigration-based policy could make a low-fertility population older rather than younger. The paper includes examples using U.S. and West German vital rates.

Adolescent↗
PubMed2006

Fracture reducing potential of hormone replacement therapy on a population level.

OBJECTIVES: To study the fracture reducing potential of hormone replacement therapy (HRT) at a population level, the effect of age on the fracture reducing potential of HRT, and to examine whether socio-economic factors confound the effects of HRT on fracture risk. SUBJECTS AND METHODS: Case-control study. All women who sustained any fracture during the year 2000 in Denmark served as cases (n=64,548). For each case, three age-matched controls were randomly drawn from the background population (n=193,641). The main exposure was the average daily dose of HRT (expressed as defined daily doses DDD/day). Adjustments were made for co-morbidity, socio-economic factors, and prior fracture. RESULTS: A fracture risk reduction was seen in women aged>or=50 years using >or=0.3 DDD/day. The risk reduction for any fracture was larger in women aged>or=60 years (0.3-0.99 DDD/day: odds ratio (OR)=0.77, 95% confidence intervals (CI): 0.73-0.82, >or=1 DDD/day: OR=0.61, 95% CI: 0.56-0.67) than in women aged 50-59 years (0.3-0.99 DDD/day: OR=0.92, 95% CI: 0.85-0.99, >or=1 DDD/day: OR=0.77, 95% CI: 0.70-0.84). Larger risk reductions were seen for Colles' fractures (age 50-59 years: OR=0.64 for 0.3-0.99 DDD/day, and OR=0.57 for >or=1 DDD/day, age>or=60 years: OR=0.52 for 0.3-0.99 DDD/day, and OR=0.40 for >or=1 DDD/day). Adjustment only changed the estimates little. No difference between oral and dermal preparations could be found. CONCLUSIONS: Hormonal replacement therapy possesses a fracture-reducing potential at population level even at dosages lower than usually recommended. The risk reduction was larger with advancing age for any fracture and Colles' fractures.

Case-Control Studies↗
PubMed2004

Neanderthals and the modern human colonization of Europe.

The fate of the Neanderthal populations of Europe and western Asia has gripped the popular and scientific imaginations for the past century. Following at least 200,000 years of successful adaptation to the glacial climates of northwestern Eurasia, they disappeared abruptly between 30,000 and 40,000 years ago, to be replaced by populations all but identical to modern humans. Recent research suggests that the roots of this dramatic population replacement can be traced far back to events on another continent, with the appearance of distinctively modern human remains and artefacts in eastern and southern Africa.

Africa↗
PubMed1982

Antigenic variation of Borrelia hermsii.

At least 24 different serotypes were detected in populations of Borrelia hermsii that originated from a single organism. These serotypes were identified by staining with specific fluoresceinated antisera prepared against cloned populations of living organisms of each type. In the order of decreasing frequency, the 10 types more often encountered were 7, which was clearly dominant, and 2, 17, 24, 13, 2, 1, 21, 11, and 12. Each of the 24 types were shown to change to 7 or more other serotypes. Spirochetemia in mice was persistent, and relapses occurred when the concentration of organisms was sufficient for detection by visual means. After mice were inoculated with a single organism, peak spirochetemia usually occurred on day 4, after which clearance of organisms occurred, and an apparently pure population was replaced by a mixed population consisting of as many as seven variants. These types persisted for 2-3 d before being replaced by other types. Conversions occurred constantly and were independent of relapses. The rate of conversion in mice treated with cyclophosphamide to delay antibody production was comparable to that of controls. Spontaneous conversion was clearly demonstrated in tubes of fortified Kelly's medium inoculated with a single organism of type 7 or 21. 11 different variants appeared in eight cultures of type 21 by the time growth had reached 4 X 10(6)-10(7) organisms/ml. The rate of spontaneous change was estimated to be or approximately 10(-4)-10(-3) per cell per generation.

Antigens, Bacterial↗
PubMed2001

"Mitotic drive" of expanded CTG repeats in myotonic dystrophy type 1 (DM1).

In myotonic dystrophy type 1 (DM1), an expanded CTG repeat shows repeat size instability in somatic and germ line tissues with a strong bias toward further expansion. To investigate the mechanism of this expansion bias, 29 DM1 and six normal lymphoblastoid cell lines (LBCLs) were single-cell cloned from blood cells of 18 DM1 patients and six normal subjects. In all 29 cell lines, the expanded CTG repeat alleles gradually shifted toward further expansion by "step-wise" mutations. Of these 29 cell lines, eight yielded a rapidly proliferating mutant with a gain of large repeat size that became the major allele population, eventually replacing the progenitor allele population. By mixing cell lines with different repeat expansions, we found that cells with larger CTG repeat expansion had a growth advantage over those with smaller expansions in culture. This growth advantage was attributable to increased cell proliferation mediated by Erk1,2 activation, which is negatively regulated by p21(WAF1). This phenomenon, which we designated "mitotic drive" , is a novel mechanism which can explain the expansion bias of DM1 CTG repeat instability at the tissue level, on a basis independent of the DNA-based expansion models. The lifespans of the DM1 LBCLs were significantly shorter than normal cell lines. Thus, we propose a hypothesis that DM1 LBCLs drive themselves to extinction through a process related to increased proliferation.

Cell Division↗