The influence of age, sex, race, and body habitus on kidney weight in humans

The impact of age, sex, race, and body build on kidney weight was examined in 357 normal individuals who died suddenly. Mulivariate, stepwise linear-regression analysis demonstrated that kidney weight was best predicted by body surface area. Age, sex, and race had no additional impact on kidney weight once differences in body build were taken into account. Similar results were obtained with heart and liver weights. These findings were confirmed using a second, independent paired sample of 16 lean and 16 massively obese adults. Body build-associated changes in kidney weight were paralleled by changes in both glomerular and tubulointerstitial areas. Body build is the major determinant of kidney weight and nephron size in normal humans.     

The influence of age,race, and gender on peripheral blood mononuclear-cell subsets in healthy nonsmokers

To investigate the influence of age, race, and gender on the cellular immune system, we determined T-cell, B-cell, monocyte, natural killer (NK)-cell, and HLA-DR⁺-cell subsets in 266 nonsmokers from a population-based random sample of healthy adults using monoclonal antibodies and flow cytometry. Blacks had a lower total white blood-cell count than whites (P0.0001), due primarily to a decrease in granulocytes. There was no significant difference in absolute lymphocyte count between blacks and whites. Blacks had a higher proportion of CD19⁺ cells (Leu 12⁺ B cells) and a lower proportion of CD3⁺ cells (OKT3⁺ T cells) than whites (P0.01). Female sex and increasing age were independently associated with an increased percentage of CD4⁺ cells (OKT4A⁺ helper-inducer T-cell subset), resulting in a higher helper/suppressor ratio among women and older individuals (P0.05). Black race and increasing age were independently associated with an increased proportion of HLA-DR⁺ cells (P0.0001) which was not attributable to B cells or monocytes. No significant age, race, or gender effects were observed for CD14⁺ cells (Leu M3⁺ monocytes) or CD16⁺ cells (Leu 11A⁺ natural killer cells). These data demonstrate that age, race, and gender are each associated with significant differences in peripheral blood monouclear-cell subsets. Population-based data such as these provide an important foundation for future design and interpretation of human flow cytometry data.     

The influence of race and gestational age on the age of maximum risk of SIDS in infancy

Risk of sudden infant death syndrome (SIDS) reaches a maximum in the third month. Thereafter, it decreases by half every 40 days or so. It is proposed that the relative sparing of the very young infant is a consequence of an innate (but temporary) characteristic possessed by the newborn infant. Interpretation of available data suggests that this innate characteristic is negatively associated with the infant's level of maturity. This is the basis for the hypothesis that the age at which the risk of SIDS begins to decline at a uniform rate decreases as the infant's gestational age increases. Because of a greater level of maturity at birth, the age at which this occurs in the black infant should be earlier than average. An analysis of data on 32 573 instances of SIDS within the United States between 1985 and 1991 provides support for the hypothesis.     

Secretion of salivary immunoglobulin a in relation to age,saliva flow,mood states,secretion of albumin,cortisol, and catecholamines in saliva

Salivary immunoglobulin A (IgA) is one characteristic humoral factor of the local immune system in the upper respiratory tract. Epidemiological studies emphasize the importance of secretory IgA in the protection from infections of the upper respiratory tract. However, due to high interindividual variability of secretion of salivary IgA, it remains difficult to define normal ranges. This series of studies focused on identification of factors influencing basal secretion of salivary IgA. The results indicate a significant relationship between age and salivary IgA concentration. Children below 7 years have lower salivary IgA concentration than children above 7 years or adults. Furthermore, a significant inverse relationship between saliva flow and salivary IgA concentration was found. Gender, mood states, salivary albumin, salivary catecholamines, and salivary cortisol were not associated with salivary IgA. It can be concluded that for defining normal ranges of salivary IgA, age and saliva flow have to be considered.     

Cerebral atherosclerosis in New Orleans. Comparisons of lesions by age, sex, and race

We compared mean extent of atherosclerotic lesions in carotid and intracranial arteries at autopsy among age, sex, and race subgroups in New Orleans. Most comparisons were made within similar broad cause-to-death categories after excluding deaths due to diseases associated with increased amount of atherosclerosis. Use of this basal group of cases reduces the effect of selection bias due to cause of death in this autopsy population. Fatty streaks were present in the carotid arteries of almost all cases even in the youngest age group (10 to 14 years) and were more extensive in blacks than in whites. Raised atherosclerotic lesions increased with age in the carotid arteries of blacks from age group 15 to 24 years and in whites from age group 25 to 34 years; black men and white men had about the same amount of raised lesions, whereas black women consistently had more than white women. In the intracranial arteries, fatty streaks and fibrous plaques began from age 15 to 24 years; blacks had more raised lesions than whites, particularly in the oldest age group, 65 to 69 years. These findings and mortality data suggest that in the 1960s and early 1970s black men and women were more susceptible to cerebral atherosclerosis and cerebrovascular diseases than white men and women.     

The influence of sex, age and BMI on the degeneration of the lumbar spine

Previous research on lumbar spine osteophyte formation has focused on patterned development and the relation of age and sex to degeneration within the vertebral bodies. The inclusion of osteophytes originating on the laminae and body mass index (BMI) may result in a more complete evaluation. This study investigates lumbar osteophyte development on the laminae and vertebral bodies to determine whether osteophyte development: (i) is related bilaterally, at different lumbar levels, and superior and inferior margins; (ii) on the laminae and vertebral bodies are reciprocally dependent responses; (iii) is correlated with sex, age and/or BMI. Seventy-six individuals (39 females, 37 males) were randomly selected from a modern skeletal collection (Bass Donated Collection). Osteophyte development was scored in eight regions on each vertebra at all five lumbar levels. A factor analysis considered all 40 scoring regions and Pearson's correlation analyses assessed the relatedness of age and BMI with the consequent factors. The factor analysis separated the variables into two similar factors for males and females defined as: (i) superior and inferior vertebral body scores and (ii) superior laminar scores at higher lumbar levels. The factor analysis also determined a third factor for females defined as: (iii) inferior laminar scores at lower lumbar levels. The severity of vertebral body osteophytes increased with age for both sexes. Additionally for females, as BMI increased, osteophyte severity increased for both the superior laminar margins higher in the column and the vertebral bodies. Dissimilarities between the factors in males and females and the correlation of BMI to osteophyte severity exclusively in females provide evidence for different biomechanical processes influencing osteophyte development.     

Variation of the Anthropometric Index for pectus excavatum relative to age,race, and sex

OBJECTIVES:

To determine possible variations in the Anthropometric Index for pectus excavatum relative to age, race, and sex in individuals free of thoracic wall deformities.

METHODS:

Between 2002 and 2012, 166 individuals with morphologically normal thoracic walls consented to have their chests and the perimeter of the lower third of the thorax measured according to the Anthropometric Index for pectus excavatum. The participant characteristics are presented (114 men and 52 women; 118 Caucasians and 48 people of African descent).

RESULTS:

Measurements of the Anthropometric Index for pectus excavatum were statistically significantly different between men and women (11–40 years old); however, no significant difference was found between Caucasians and people of African descent. For men, the index measurements were not significantly different across all of the age groups. For women, the index measurements were significantly lower for individuals aged 3 to 10 years old than for individuals aged 11 to 20 years old and 21 to 40 years old; however, no such difference was observed between women aged 11 to 20 years old and those aged 21 to 40 years old.

CONCLUSION:

In the sample, significant differences were observed between women aged 11 to 40 years old and the other age groups; however, there was no difference between Caucasian and people of African descent.     

Immunological characterization of plasminogen activators in human mixed saliva

In mixed saliva obtained from six healthy volunteers, the plasminogen activators were characterized immunologically using antibodies specific for human tissue plasminogen activator and urokinase, which were raised in goats immunized with low molecular weight urokinase and tissue-type activator from melanoma cells. The fibrinolytic activity in mixed saliva upon stimulation was assayed on fibrin plates containing plasminogen after preincubation with immunoglobulins with and without specific antibodies. In both centrifuged and uncentrifuged saliva, antibodies against tissue plasminogen activator completely quenched the fibrinolytic activity. By contrast, antibodies against urokinase had no suppressive effect, neither did non-immunized goat serum influence the fibrinolytic activity in mixed saliva. In conclusion, during physiological conditions tissue plasminogen activator appears to regulate fibrinolytic activity in mixed saliva, in which no activity of urokinase-like plasminogen activators could be demonstrated.     

Plasma fibronectin: influence of age and sex

The aim of this study was to determine, first, the effect of sex and age on the results of plasma fibronectin (Fn), and also the possible influence of the gestational age. The plasma Fn concentrations are higher in men than in women only in a range of 15-29 years old. The age dependence is very strong on plasma Fn levels; it practically double during life. The Fn concentrations according to age increase exponentially in men, linearly in women. The influence of gestational age is effective when it is less than thirty one weeks. Then, the Fn concentrations are significantly lower than in healthy newborn infants.     

Effects of age, sex, and psychological disturbance on immunoglobulin levels in the squirrel monkey

The following research assessed the influence of developmental, hormonal, and psychological factors on immunoglobulin and complement protein levels in the squirrel monkey. A cross-sectional life span study established that the developmental pattern of immunoglobulins and complement proteins was similar to that observed in humans. IgG and IgM levels rose progressively with age, while the complement system was mature at birth. In contrast to humans, this species showed a significant sex difference in IgG levels, with higher levels in males during both infancy and adulthood. Males also showed a greater antibody response to viral challenge than did females, and evaluation of gonadectomized subjects suggested that the sex difference in antibody production was testosterone-dependent. The effect of acute and sustained psychological disturbance on IgG levels was also evaluated in infant monkeys. Repeated, brief separations from the mother did not alter IgG levels, but IgG levels were suppressed after a 7-day removal from the mother. Therefore, despite the general view that immunoglobulin levels are relatively stable, these studies have established that immunoglobulin levels can be strongly influenced by hormonal and experiential factors in the squirrel monkey.     

Immunoglobulin A antibody levels in human tears, saliva, and serum.

The presence and level of immunoglobulin A (IgA) antibodies to the oral microorganism Streptococcus mutans were determined in human tears, parotid saliva, and serum by a modified, indirect enzyme-linked immunosorbent assay. IgA antibodies were found in the tears of all 15 subjects, although S. mutans is a nonocular bacterium. The IgA antibody levels in tears and saliva were not significantly different. This finding suggests that the level of IgA antibody activity per volume is independent of the naturally occurring site of the antigen, and that local stimulation does not cause a significant difference in the antibody level per volume of secretion between exocrine sites. Much higher levels of IgA antibody were present in serum, suggesting that after oral ingestion of antigen both the systemic and exocrine systems are stimulated. IgG antibodies to S. mutans were also found in human tears, saliva, and serum. No relationship between serum levels and tear and saliva levels was found for either IgA or IgG antibodies. Thus the antibodies in tears and saliva did not appear to have leaked from serum. We conclude that there may be remote regulation of both the ocular and the parotid IgA and IgG antibody systems.     

Relationships between levels of lysozyme, lactoferrin, salivary peroxidase, and secretory immunoglobulin A in stimulated parotid saliva.

Recent studies suggest that salivary lysozyme (Lz), lactoferrin (Lf), peroxidase (Spx), and secretory immunoglobulin A (sIgA) may interact in a common antimicrobial system. A multiple protein approach therefore may be needed to determine the role of this system in oral health and ecology. In the present study we investigate the relationships between levels of Lz, Lf, Spx, and sIgA (adjusted for flow rate and total protein) in stimulated parotid saliva from 44 dental students. Principal components analysis was used to determine major patterns of intercorrelation between variables; cluster analysis was used to identify groups of subjects with similar salivary profiles for Lz, Lf, Spx, and sIgA. Spx tended to vary independently of Lz and Lf, which, in turn, tended to vary together. sIgA showed a weak negative relationship with Spx and a weak positive relationship with Lz and Lf. Six major clusters of subjects with similar antimicrobial protein profiles were found. These were significantly different at P less than 0.0001. Spx was the most important determinant of cluster membership followed (in order of importance) by Lz, Lf, and sIgA. Cluster profiles were Spx-, sIgAmu, Lf-, Lz-; Spx-, sIgA+, Lfmu, Lz+; Spxmu, sIgAmu, Lfmu, Lzmu; Spx+, sIgA-, Lf-, Lz-; Spx+, sIgAmu, Lf+, Lz-; and Spx+, sIgAmu, Lf+, Lz+ (-, mu, and + refer to the position of the cluster mean each variable relative to the overall mean for that variable). Results suggest that clusters may be a product of independent variation in the secretory activity of acinar and intercalated duct cells.