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Biomedical subjects

C C Plato

Publications and source records attributed to C C Plato.

At least 19 recordsLinked to original sources
PubMed1992

Estimation of prostatic growth using serial prostate-specific antigen measurements in men with and without prostate disease.

Prostate growth curves were estimated from serial prostate-specific antigen (PSA) measurements on frozen sera in three groups of men: (a) 16 men with no prostatic disease by urological history and examination; (b) 20 men with a histological diagnosis of benign prostatic hyperplasia (BPH) who had undergone simple prostatectomy; and (c) 18 men with a histological diagnosis of prostate cancer. The median number of repeated PSA measurements over an 8- to 26-yr period prior to histological diagnosis or exclusion of prostate disease was eight and 11 for noncancer and cancer subjects, respectively. Predicted rates of change in PSA (PSA velocity) were linear and curvilinear for control and BPH subjects, respectively. Subjects with cancer demonstrated both a linear and an exponential phase of PSA velocity. Based on time to double PSA, we estimated the epithelial doubling time for men without prostate disease to range from 54 +/- 13 yr at age 40 to 84 +/- 13 yr at age 70. For men with BPH, doubling times ranged from 2 +/- 13 yr at age 40 to 17 +/- 5 yr at age 85. Subjects with local/regional and advanced/metastatic cancer had similar PSA doubling times of 2.4 +/- 0.6 yr and 1.8 +/- 0.2 yr, respectively. These data are consistent with what is known about prostatic growth with age in men without prostate disease and BPH, and the kinetics of prostate cancer growth. Estimates of prostatic growth rate from changes in PSA may be useful clinically in management of men with prostate disease.

Aged↗
PubMed1992

Biochemical parameters associated with low bone density in healthy men and women.

A causal role in age-related bone loss has been attributed to alterations in vitamin D status, the bone mineral regulating hormones, and/or renal function. We assessed biochemical parameters of bone metabolism and renal function in healthy subsets of young and old men (n = 191) and women (n = 120) and evaluated the relationships between these parameters and bone mineral density (BMD) in the radius, spine, and femur. There were no significant associations between BMD at any site and serum 25-OHD, 1,25-(OH)2D, PTH, or creatinine clearance in either young men or in young or old women, after controlling for age. In old men, however, lower radius BMD was significantly related to higher PTH and higher 1,25-(OH)2D and marginally related to lower 25-OHD values. In young men, there were unexpected but significant associations between lower femoral neck BMD and higher serum osteocalcin and urinary calcium/creatinine excretion after age adjustment. In old women, lower spine and radius BMD was also significantly correlated with higher serum osteocalcin. In this healthy, vitamin D-replete population, there were significant cross-sectional declines in BMD in the femur in young and old men and at all sites in old women. Elevated remodeling may be an important feature that contributes to reduced femoral BMD in young men and reduced spine and radius BMD in old women. However, compromised renal function or levels of 1,25-(OH)2D or elevated PTH appear to be neither necessary nor relevant as determinants of osteopenia in the spine or femur in these normal, healthy men and women.

Adult↗
PubMed1992

Sex differences in geometry of the femoral neck with aging: a structural analysis of bone mineral data.

The greater hip fracture rate among elderly women is generally ascribed to differences in femoral neck strength between the sexes. Strength of a given bone is a function of both its material properties and the magnitudes of mechanical stresses within it. This study examined the hypothesis that these apparent strength differences between the sexes are due to dissimilarities in the restructuring of the femoral neck with age, which result in higher stresses in elderly women. Using Hip Strength Analysis, a computer program developed by the authors, femoral neck cross-sectional geometric properties for stress analyses were derived from bone mineral image data of 409 community living, white subjects ranging from 19 to 93 years of age. Though both sexes show declines in femoral neck bone mineral density (BMD) and cross-sectional area with age, only females show a decline in the cross-sectional moment of inertia (CSMI, a geometric index of bone rigidity). The lack of decline in male CSMI appears to be a result of a small but significant increase in femoral neck girth. Similar age-related changes have been observed in the femoral shaft by others. The net effect of these observed changes is that mechanical stresses in the femoral neck of females appear to increase at three times the rate per decade of those of males. These results lend support to the hypothesis that the higher fracture rate in elderly women is due, at least in part, to elevated levels of mechanical stress, resulting from a combination of greater bone loss and less compensatory geometric restructuring with age.

Adult↗
PubMed1992

Factor structure of morphometric variables measured on six metacarpal bones.

Morphometry of the second, third and fourth metacarpal bone was performed on hand-wrist radiograms of both hands in a sample of 434 male and 549 female adult subjects. Morphometric data (bone length-L, total diaphysis width-T and medullary canal width-M) and age were processed using principal factor analysis with oblique rotation, separately for males and females. In both sexes three factors accounting for 74.7% of the total variance were extracted, but their patterns of variation differed. Factors-"cumulative environmental-genetic factor", "longitudinal factor", and "transversal factor"-are discussed within the context of their biological meaning affecting the phenotypic formation of metacarpal skeleton in a given population.

Adult↗
PubMed1991

Factors associated with osteoarthritis of the hand in males: data from the Baltimore Longitudinal Study of Aging.

The association of metabolic and physiologic factors with hand osteoarthritis was studied in 888 Caucasian male subjects aged 17-102 years in the Baltimore Longitudinal Study of Aging. Left-hand radiographs taken between 1958 and 1975 were read by one investigator for grade of osteoarthritis using Kellgren-Lawrence scales. Possible risk factors, assessed at the same visit as the last radiograph during this interval, included age and measures of bone mass, body composition, muscle mass, and muscle strength. Results of bivariate analyses of these cross-sectional data showed that increasing grade of hand osteoarthritis was associated with increasing age; greater mean levels of waist/hip ratio and percentage of body fat; and lower mean levels of percentage of cortical area, grip strength, and forearm circumference. After adjustment for age using residuals from best-fit quadratic regression models, none of these independent variables remained significantly associated with grade of hand osteoarthritis. These data fail to support hypotheses that metabolic and physiologic factors are associated with hand osteoarthritis independent of their known age-related changes.

Adolescent↗
PubMed1990

Dermatoglyphics in the identification of women either with or at risk for breast cancer.

Fingerprints and palm prints were studied in 78 breast cancer patients, 391 patients at increased risk for developing breast cancer, and 64 control patients for the purpose of finding a pattern that would identify those women with breast cancer or those who are predisposed to its development. A pattern of 6 or more digital whorls was identified more frequently in women with breast cancer than in those without the disease (P less than 0.01). This finding was independent of known risk factors for breast cancer and was present in 28% of the cancer patients. No correlation was noticed between palm prints and breast cancer. The positive predictive value of 6 or more digital whorls was comparable to that of mammography and that of breast biopsy. With increasing age there was an increase in the positive predictive value associated with 6 or more digital whorls. It is concluded that digital dermatoglyphics may have a future role in identifying women either with or at increased risk for breast cancer such that either risk reduction measures or earlier therapy may be instituted.

Adult↗
PubMed1990

Embryological development and prevalence of digital flexion creases.

The embryological development and morphology of digital flexion creases were studied in 178 human embryos and fetuses 6-20 weeks of gestational age. The results suggest the existence of two types of digital flexion creases, that differ from each other in their development. The regular creases, with the exception of the distal crease of the proximal interphalangeal creases, and the oblique and extra creases of the irregular creases, develop concurrently with the appearance of the digital pads by about 11 weeks of gestation. The remaining creases, i.e., the distal crease of the proximal interphalangeal creases and the accessory crease develop later unrelated to the pads but, apparently, secondary to the flexion movements of the hand. Our observations further suggest that, because of their high frequencies, the oblique creases on the ulnar side of digits I and II and on the radial side of digit V and the extra creases on the proximal phalanx of digits I, III, and IV should be considered as "regular" creases. Previously unreported pads were also found on the middle phalanges at about 11 weeks of gestation. Unlike the single, large pads with high elevation, typically found on the distal phalanges, those on the middle phalanges are multiple, small, and only slightly elevated. This observation provides further support to the concept of the relationship between the fetal digital pads and the development of the epidermal ridge patterns.

Fetus↗
PubMed1990

The role of muscle loss in the age-related decline of grip strength: cross-sectional and longitudinal perspectives.

The decline of strength with age has often been attributed to declining muscle mass in older subjects. To investigate factors which might influence changes in strength across the life span, grip strength and muscle mass (as estimated by creatinine excretion and forearm circumference) were measured in 847 healthy volunteers, aged 20-100 years, from the Baltimore Longitudinal Study of Aging. Cross-sectional and longitudinal results concur that grip strength increases into the thirties and declines at an accelerating rate after age 40. However, the grip strength of 48% of subjects less than 40 years old, 29% of individuals 40-59 years old, and 15% of subjects older than 60 did not decline during the average 9-year follow-up. Grip strength is strongly correlated with muscle mass (r = .60, p less than .0001). However, using multiple regression analysis, grip strength is more strongly correlated with age (partial r2 = .38) than muscle mass (partial r2 = .16). Additionally, a residuals analysis demonstrates that younger subjects are stronger and older subjects are weaker than one would predict based on their muscular size. Thus, while strength losses are partially explained by declining muscle mass, there remain other yet undetermined factors beyond declining muscle mass to explain some of the loss of strength seen with aging.

Adult↗
PubMed1989

The effect of a pattern in palmar interdigital II on a-b ridge count in black and white Down syndrome cases and controls.

An unconfirmed study by Fang (Ph.D. thesis, Univ. of London, 1950) in Britain showed that individuals with Down syndrome had lower total a-b ridge counts in palmar Interdigital area II (ID II) than a group of controls. This study compares 603 white Down syndrome cases and 93 black Down syndrome cases with 668 white and 402 black controls. Our results confirm those of Fang in that the Down syndrome cases in both racial groups had lower total a-b ridge counts than their respective controls. In addition, the black controls and Down syndrome cases had lower a-b ridge counts than their white counterparts. The mean a-b ridge count was significantly lower in individuals with a pattern in ID II compared to individuals without a pattern in ID II in both the Down syndrome and control groups. Some of the lower a-b ridge counts in the Down syndrome samples can be accounted for by the fact that there is an increased frequency of a pattern in ID II in Down syndrome cases. Both Down syndrome and normal individuals who had a pattern unilaterally had a lower than expected a-b ridge count on the contralateral hand that did not have a pattern. There was a tendency also for increased asymmetry in Down syndrome cases with a pattern in ID II.

Analysis of Variance↗
PubMed1989

Bone mass in Guamanian patients with amyotrophic lateral sclerosis and parkinsonism-dementia.

Bone mass, as assessed by measurements of total subperiosteal diameter and medullary width of the second metacarpal bone on hand-wrist radiographs, was evaluated for 31 Guamanian patients (15 males, 16 females) with amyotrophic lateral sclerosis (ALS), 67 patients (39 males, 28 females) with parkinsonism-dementia (PD), and 66 (34 males, 32 females) nonaffected Guamanian controls. Comparisons between the two disease groups and between each disease group and the nonaffected controls were made taking into account the sex, age, and disability status of each participant. At all ages, ALS patients of both sexes had significantly lower percent cortical areas (PCA) than did nonaffected controls. The ALS males also had significantly lower PCA than PD males, although no significant differences were observed between female ALS and PD patients. The PD patients of either sex had a lower PCA when compared to controls, but the differences were not statistically significant. The observed differences in PCA were due solely to increased medullary width, suggesting that the diminished cortical bone thickness resulted from greater bone resorption rather than differential bone growth. Longitudinal studies support the cross-sectional findings of accelerated bone loss among ALS patients. It is not possible to determine from the present data whether the observed differences in PCA of the second metacarpal of the ALS patients are due to atrophy of the first interosseous muscle, to a generalized resorption process inherently associated with the development and progression of ALS, or to factors not accounted for by the present analysis.

Adult↗
PubMed1988

Digital and palmar dermatoglyphics in dementia of the Alzheimer type.

Digital and palmar dermatoglyphics were examined in 29 men and 27 women with dementia of the Alzheimer type (DAT) and 112 age-, sex-, and racial group-matched controls. Female patients had significantly (p less than 0.05) more accessory triradii and complete Sydney creases than controls; no dermatoglyphic differences were detected in the males. Separating the patients by age of onset prior to or after age 65 years did not help differentiate patients from controls by dermatoglyphic profile. This study failed to confirm either the previously reported dermatoglyphic differences between DAT patients and controls or the reported similarity of the dermatoglyphic pattern of DAT to that of Down syndrome patients.

Adult↗
PubMed1986

Longitudinal study of bone loss in the second metacarpal.

This longitudinal study was undertaken to ascertain the rate of bone loss and to identify aging, cohort and/or time effects on bone loss in male participants of the Baltimore Longitudinal Study of Aging. Hand-wrist radiographs were obtained from 1958-1981 and were evaluated for total width, medullary width, and length of the second metacarpal. Data were analyzed using an age-time matrix with 8-year intervals for three epochs and nine age groups. The bone measurements were analyzed in three perspectives (cross-sectional, longitudinal and time-series). The results demonstrate that there is both a cross-sectional and longitudinal loss of cortical bone with age in the second metacarpal. Furthermore, the results show that males lose approximately 14% of their cortical bone, at a rate of about 2% per decade, over the adult lifespan. The majority of this loss occurs between the ages of 45 and 69 and is due primarily to aging and is not an artifact of cohort differences or secular change.

Adult↗
PubMed1979

Osteoarthritis of the hand: age-specific joint-digit prevalence rates.

The left hand of each of 903 white males, most of them well-educated professionals, was evaluated for osteoarthritis, in the ongoing Baltimore Longitudinal Study of the Gerontology Research Center. The results of the joint-digit prevalence study indicated that: 1) the prevalence of osteoarthritis varies from one digit to the other; 2) osteoarthritis is considerably more prevalent in the distal than the proximal interphalangeal joints, regardless of digit or age group; 3) this disease is not only more prevalent in the distal interphalangeal joints, but it usually appears in a more severe form in the distal than in the proximal interphalangeal or the metacarpophalangeal joints. 4) Assuming that the presence of osteoarthritis in one joint is independent of the presence of the disease in the other joint of the same digit, there is an excess of digits with osteoarthritis in both the distal and proximal interphalangeal joints. This is suggestive of either a common etiology or that the presence of the disease in one joint enhances the development of osteoarthritis in the other joint of the same digit.

Adolescent↗
PubMed1979

Osteoarthritis of the hand: longitudinal studies.

Evaluation of the osteoarthritic grades of the hands of 478 participants of the ongoing Baltimore Longitudinal Study suggests that: 1) Joint degeneration due to osteoarthritis is a relatively slow process. The maximum rate of degeneration is seen in the distal interphalangeal joints where the average increase is about 1 grade per individual in an interval of 12 to 16 years between visits in each age group. The rate of degeneration in the proximal interphalangeal joints is much lower than that of the distal interphalangeal joints. 2) The progress of the degeneration in the distal interphalangeal joints of an individual (longitudinally evaluated) follows closely that which is observed at the population level (cross-sectional joint-digit study). That is, it is directly related to the age and the interval between visits. This is not always seen in the proximal interphalangeal joint data. 3) The rate of change in the osteoarthritic grade of individual hands agrees closely with that of their distal interphalangeal joints. This further supports the conclusions reached in a first report that what has been referred to as osteoarthritic grade of the hand of an individual may actually be the higher grade among the distal interphalangeal joints.

Adult↗