Search PubMed⌕ Search

Biomedical subjects

C C Plato

Publications and source records attributed to C C Plato.

At least 55 records · Page 3Linked to original sources
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↗
PubMed1986

Amyotrophic lateral sclerosis and parkinsonism-dementia on Guam: a 25-year prospective case-control study.

Familial and genetic studies of high-incidence amyotrophic lateral sclerosis and parkinsonism-dementia among the Chamorro people of Guam were initiated in 1958 with the establishment of a prospective case-control registry. The major objective of this registry was to determine if first-degree relatives and spouses of patients with amyotrophic lateral sclerosis or parkinsonism-dementia had an increased risk of developing disease compared with relatives of nonaffected controls individually matched for age, sex, and village. At the time of its closing in 1963, the registry included 126 patients (77 with amyotrophic lateral sclerosis, 42 with parkinsonism-dementia, and seven with both amyotrophic lateral sclerosis and parkinsonism-dementia) and an equal number of controls; 994 living first-degree relatives (parents, siblings, and offspring) of patients and 1,218 of controls; and 88 living spouses of patients and 101 of controls. The present analysis of the 25-year follow-up study (1958-1983) demonstrated a significantly increased risk of developing amyotrophic lateral sclerosis or parkinsonism-dementia among parents, siblings, and spouses of patients, but not among relatives of controls. Offspring of both patients and controls showed no significantly increased risk of developing disease. The increased risk among spouses of patients and the lack of increase among their offspring, together with recent histochemical findings, support the contention that exogenous factors are strong contributors to the etiology of amyotrophic lateral sclerosis and parkinsonism-dementia. The present results also demonstrate a declining incidence of both diseases.

Aged↗
PubMed1985

Markers of genetic variation among the Waorani Indians of the Ecuadorian Amazon headwaters.

Until recently, the Waorani Indians of Ecuador's Amazon headwaters maintained a fierce resistance to all intruders into their territory, and as a result of their actions and reputations a population of 600 people controlled a very large territory (about 8,000 square miles). The isolation of the Waorani has resulted in a large linguistic and genetic distance from their neighbors. Our survey of red cell enzymes, immunoglobulin allotypes, and dermatoglyphics demonstrates that the Waorani are a highly inbred and homogeneous population. Of 18 red cell enzymes studied, the Waorani have a limited polymorphism for only 6. Only two Gm haplotypes (Gm1,2,17,21, Gm1,17,21) were found and 60% of those tested were homozygous for the Gm1,17,21 haplotype. All individuals were A2m (1) and 95% of these were homozygous. The Waorani's dermatoglyphic traits fell within the wide range found among other South American Indians with close affinity to the Ecuadorian Jivaro group. Despite the limitations of these genetic systems, they demonstrate that the Waorani share limited genetic traits with the neighboring Jivaro Indians and are isolated from other tribal populations in South America.

Dermatoglyphics↗
PubMed1984

Cortical bone loss and measurements of the second metacarpal bone: II. Hypodense bone in postwar Guamanian children.

Hand-wrist radiographs from 326 Guamanian children (180 boys and 146 girls) were evaluated for total width, medullary width, length, and combined cortical thickness of the second metacarpal. Bone measurements as well as standing height and weight were compared to similar published data from U.S. mainland black, white, and Mexican-American children. The results demonstrated that the second metacarpal bones of Guamanian boys and girls of all age groups (5-17 years) have narrower width and shorter length with less combined cortical thickness than any of the other groups. Guamanian children also weighed less and were of shorter stature than their black, white, or Mexican-American counterparts. These results agree closely with those comparisons between Guamanian and U.S. mainland white adults published earlier. It is not possible from the present data to ascertain whether these differences were due to genetic variability or nutritional deficiency.

Adolescent↗
PubMed1984

Calcium and vitamin D metabolism in Guamanian Chamorros with amyotrophic lateral sclerosis and parkinsonism-dementia.

We evaluated 16 Guamanian Chamorros with amyotrophic lateral sclerosis and 33 patients with parkinsonism-dementia for disturbances of calcium and vitamin D metabolism. The serum immunoreactive parathyroid hormone level was mildly elevated in 6 patients with amyotrophic lateral sclerosis and in 5 patients with parkinsonism-dementia. There were significant positive correlations between serum immunoreactive parathyroid levels and duration of illness in male patients with motor neuron disease, but not in female patients or in patients with parkinsonism-dementia. Intestinal absorption of calcium, as assessed by serum and urinary activity of calcium 47 following oral administration, was decreased in 2 patients with amyotrophic lateral sclerosis and in 4 patients with parkinsonism-dementia, all of whom had low levels of serum 1,25-dihydroxyvitamin D. Reductions in cortical bone mass were striking in patients with motor neuron disease. A significant negative correlation was found between the percentage of cortical area of the second metacarpal bone and muscle atrophy and weakness, and significant positive correlations were found between degree of immobility and ratio of urinary hydroxyproline to creatinine in patients with amyotrophic lateral sclerosis and parkinsonism-dementia. In general, abnormalities in calcium metabolism were subtle. Thus, if the demonstrated deposition of metals, particularly calcium and aluminum, in central nervous system tissues of Guamanians with these two conditions is a cause of the diseases and of the early appearance of neurofibrillary tangles in neurons, the accumulation has apparently occurred long before onset of symptoms, and detectable abnormalities of calcium and vitamin D metabolism may already have been corrected.

Adult↗
PubMed1983

Blood groups, immunoglobulin allotypes and dermatoglyphic features of patients with amyotrophic lateral sclerosis and parkinsonism-dementia of Guam.

Blood group frequencies, immunoglobulin allotypes, and dermatoglyphic patterns were determined on patients with amyotrophic lateral sclerosis (ALS) and parkinsonism-dementia (PD), two chronic, degenerative, neurologic disorders of unknown cause found commonly among the Chamorros of the Mariana Islands, in an attempt to identify a specific genetic or phenetic marker associated with either disorder. With the exception of the Kidd system, no significant differences were found in blood group frequencies nor in immunoglobulin allotypes between ALS patients, PD patients, and unaffected controls. The dermatoglyphic analysis demonstrated that ALS patients had higher frequencies of palmar patterns and accessory triradii in the IV interdigital area, and PD patients had significantly higher frequencies of complete simian creases and of palmar patterns in the thenar/I interdigital area than unaffected controls. The frequencies of the remaining dermatoglyphic traits showed no significant differences. We conclude that none of the marker systems tested show a particular pattern of association in patients and controls or a genetic predisposition to either disorder, and that early identification of at-risk individuals remains elusive.

Amyotrophic Lateral Sclerosis↗
PubMed1983

Studies of endemic cretinism in Papua New Guinea: digital and palmar dermatoglyphic patterns.

We have tested the hypothesis that the abnormal development of the central nervous system seen in endemic cretinism might be accompanied by concurrent abnormal dermatoglyphic patterns. We compared digital and palmar dermatoglyphics of normal individuals and endemic cretins inhabiting the Huon Peninsula of Papua New Guinea. The population sampled from the Irumu River Valley included 118 males and 114 females with 22 male cretins and 23 female cretins. The population sampled from the Wantoat River Valley included 72 males and 38 females with 12 male cretins. No pathognomonic patterns were found that could identify the endemic cretin subpopulation. However, the occurrence of a number of differences between controls and cretins suggests that subtle changes in dermatoglyphic patterns accompany the anomalous development of the CNS secondary to maternal iodine deficiency. We discuss the significance of these findings and compare the dermatoglyphic patterns of normal Irumu and Wantoat natives and 21 other populations of Papua New Guinea.

Congenital Hypothyroidism↗
PubMed1983

Further studies on the genetics of the Chamorros of Guam: dermatoglyphics.

The present study represents a continuation of our efforts to further define the genetic structure of the Chamorro population of Guam. The dermatoglyphic features of Guamanian Chamorros differ significantly from those of Western Carolinians from the Outer Islands of Yap in fingerprint patterns, model types of C line, frequency of patterns in the thenar/I area and in the presence of Sydney creases. The results of this analysis confirm earlier data from serological and other genetic markers that Guamanian Chamorros are genetically more closely related to the people of southeastern Asia than to their Micronesian neighbors to the south.

Adult↗
PubMed1982

Cortical bone loss and measurements of the second metacarpal bone. I. Comparisons between adult Guamanian Chamorros and American Caucasians.

The amount of radiographically detectable cortical bone, as determined by measurements of the second metacarpal, was evaluated in 42 male and 45 female Guamanian Chamorros and compared with the degree of bony demineralization in U.S. Caucasians participating in the Baltimore Longitudinal Study on Aging of the Gerontology Research Center. All Chamorros were individually matched to the Caucasian participants for age, sex, and menopause status. Chamorros of both sexes showed bilateral asymmetry in bone measurements and in the amount of cortical bone. Both Chamorro and Caucasian males had longer second metacarpals and more cortical bone than females. Caucasian males, however, had longer and larger second metacarpals than Chamorro males. Despite differences in the length and total width, Chamorro and Caucasian participants generally showed no significant differences in the amount of cortical bone or percent cortical area in the second metacarpal, suggesting that larger bones may not always indicate greater cortical mass. Although cross-sectional data suggested apparent age differences in the onset and rate of bone loss between Chamorros and Caucasians, the numbers of participants were too small to allow meaningful age-by-age statistical comparisons.

Adult↗
PubMed1982

Digital dermatoglyphics and breast cancer.

Fingerprints of one hundred nineteen Caucasian females were obtained. Of these females, thirty-four had histologically proven breast cancer, fifty-three were at high risk for development of breast cancer, and thirty-two comprised a control group. The digital pattern frequencies and the pattern intensity index were significantly different between the three groups. The presence of six or more whorls appears significant as noted by 32.4% of breast cancer patients possessing this number of whorls as compared to 3.1% controls. Also of note is that 95% of subjects with six or more whorls either had cancer or were at high risk.

Adult↗
PubMed1982

Digital and palmar dermatoglyphics in Greeks.

The present study presents the dermatoglyphic frequencies of two samples from Greece. The first was obtained from adult male and female inhabitants of the island of Salamis. The second is a sample of school children from various parts of Greece. Comparisons of the dermatoglyphic frequencies of the two sample showed no differences among males. Female comparisons resulted in significant differences in digital pattern frequencies, modal types of the D line and Sydney creases. These three significant differences among females only, were not considered sufficient to provide dermatoglyphic discrimination between the two to provide dermatoglyphic discrimination between the two samples and therefore were pooled into one Greek Sample. In general the dermatoglyphic frequencies of the present Greek sample fell within the range of, and very close to the mean of, other Caucasian populations. Notable differences were observed, however, in the frequencies of accessory axial triradii and complete Sydney creases in both of which the Greeks had higher frequencies.

Adolescent↗
PubMed1982

Age, sex and bilateral variability in cortical bone loss and measurements of the second metacarpal.

Bilateral hand-wrist radiographs were obtained from 176 female and 448 male adult participants of the Baltimore Longitudinal Study of Aging (BLSA). Between-age group analysis revealed no change with age in total width (TW) of the second metacarpal but a significant increase in medullary width (MW) along with decreases in per cent cortical area (PCA) and combined cortical thickness (CCT) in both sexes. The magnitude of change was greater in females compared to males after the fifth decade, suggesting an interaction of the female climacteric with those processes causing bone resorption at the endosteal surface. Those women currently on estrogen exhibited significantly higher PCA and CCT and lower MW for their respective ages compared to non-users. In females, body mass index (weight/height2) was also associated with increased PCA and CCT and decreased MW. In general, the second metacarpal was longer and larger for right hands compared to left, and for males compared to females. Right hand dominance further enhances growth of the right second metacarpal so that bilateral differences for TW, MW, CCT and LEN become statistically significant. Conversely, left hand dominance promotes growth of the left metacarpal so that none of the variables studied showed significant bilateral differences.

Adult↗
PubMed1980

Bilateral asymmetry in bone measurements of the hand and lateral hand dominance.

Two hundred thirty-five (235) normal male participants of the Baltimore Longitudinal Study were classified as right handed, left handed, and ambidextrous on the basis of their grip-strength performance. Their left and right hands were also radiographed and the measurements of the second metacarpal bones were evaluated on the basis of hand dominance. The results indicated that, as a rule, the right hand measurements are higher than those of the left hand, regardless of hand dominance. The bilateral differences in total width, length, total area and cortical area are significant among the right hand dominant and nonsignificant among the left hand dominant. Regardless of hand dominance the bilateral differences in medullary width are nonsignificant. These results suggest an inherent tendency of the right second metacarpal to have more bone than the left regardless of hand dominance. Differential stress due to hand dominance will increase the bilateral difference in the right handed and reduce it in the left handed.

Adult↗