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Biomedical subjects

R M Garruto

Publications and source records attributed to R M Garruto.

At least 91 records · Page 5Linked to original sources
PubMed1985

Population distribution of the human vitamin D binding protein: anthropological considerations.

The polymorphism of the serum vitamin D binding protein (DBP) in humans is based on the existence of three common alleles, Gc1F, Gc1S, and Gc2, and 84 rare alleles. The geographical distribution of Gc1F, Gc1S, and Gc2 alleles shows north to south clines, together with a balanced equilibrium between the Gc1F or Gc1S allele frequency and the Gc2 frequency. The distribution of the FST values shows high variability within a geographical area. For European and North Asiatic groups, the FST values are the lowest observed, and the reason may be a long process of homogenization. Aboriginal populations from Australia and New Guinea and groups from both North Africa and South America show the greatest heterogeneity of their allele frequencies. Systematic factors such as genetic drift and selection may account for this distribution. In contrast with the three main DBP alleles, the distribution of the rare alleles corresponds to patterns of human migrations that occurred during prehistoric and historic periods. Thus, the rare mutants are of particular relevance to anthropological and genetical investigations.

Alleles↗
PubMed1985

Detection of picornavirus sequences in nervous tissue of amyotrophic lateral sclerosis and control patients.

We used in situ hybridization to look for picornavirus ribonucleic acid (RNA) sequences in frozen sections of central nervous system (CNS) tissue of amyotrophic lateral sclerosis (ALS) and control patients. Using reconstruction experiments, we concluded that 30 copies of viral RNA per cell could be detected with the assay. RNA which hybridized to DNAs complementary (cDNAs) to both poliovirus and Theiler's virus was found at several levels in the CNS of 2 patients, 1 ALS patient, and 1 control. In transverse sections of the spinal cord, these sequences predominated in cells of the anterior horns. We assessed the specificity of hybridization by several criteria: no hybridization was observed with heterologous visna virus cDNA probes; hybridization was abolished by pretreatment of the sections with ribonuclease; chemography artifacts were ruled out; and the results were reproduced in three independent experiments. We concluded that RNA molecules, possibly belonging to a picornavirus having sequences in common with poliovirus and Theiler's virus, were present in the CNS of these 2 patients. On the other hand, 14 cases of classic ALS, 2 cases of Guamanian parkinsonian dementia, and 5 controls had negative results. However, the presence of picornavirus sequences in our series could be underestimated because in many cases autolysis times were 10 hours or longer.

Amyotrophic Lateral Sclerosis↗
PubMed1985

Disappearance of high-incidence amyotrophic lateral sclerosis and parkinsonism-dementia on Guam.

The high incidence rates of amyotrophic lateral sclerosis (ALS) and parkinsonism-dementia (PD) occurring among the Chamorros of Guam have declined to rates only slightly higher than those observed in the continental United States. This decline has occurred principally among males, especially those born after 1920 and living in areas where calcium and magnesium levels are low in soil and water. The male-to-female ratio among affected patients now approaches unity, compared with ratios of 2 to 1 for ALS and 3 to 1 for PD three decades ago. These changes are consistent with the hypothesis that the previously high incidence resulted from defects in mineral metabolism and secondary hyperparathyroidism, provoked by nutritional deficiencies of calcium and magnesium, with resultant deposition of calcium and aluminum in neurons.

Adult↗
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↗
PubMed1984

Imaging of calcium and aluminum in neurofibrillary tangle-bearing neurons in parkinsonism-dementia of Guam.

We report the distribution and imaging of calcium and aluminum in neurofibrillary tangle (NFT)-bearing neurons within Sommer's sector of the hippocampus in Guamanian patients with parkinsonism-dementia, using a method of computer-controlled electron beam x-ray micro-analysis and wavelength dispersive spectrometry. Calcium and aluminum were distributed in cell bodies and axonal processes of NFT-bearing neurons. The elemental images show that both calcium and aluminum deposits occur within the same NFT-bearing hippocampal neuron in this dementing disease, suggesting that these elements are involved in NFT formation. No prominent concentrations of calcium and aluminum were imaged in non-NFT-containing regions within the pyramidal cell layer of the parkinsonism-dementia cases or in the control cases. These findings support the hypothesis that secondary hyperparathyroidism resulting from low environmental calcium and magnesium in the high-incidence focus of amyotrophic lateral sclerosis and parkinsonism-dementia on Guam had led to abnormal deposition of calcium and aluminum in the central nervous system.

Aged↗
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

Search for a red cell enzyme or serum protein marker in amyotrophic lateral sclerosis and parkinsonism-dementia of Guam.

Frequency distributions were determined for 24 red cell enzyme and four serum protein systems, in an attempt to identify a genetic marker associated with either amyotrophic lateral sclerosis (ALS) or parkinsonism-dementia (PD), two progressive and fatal neurological disorders of unknown cause found with unusually high incidence among the Chamorros of Guam and the Northern Mariana Islands. No striking associations were identified between either disorder and any of the gene markers tested. Thus, no genetic cause is known for either disease; local environmental factors are most likely involved in pathogenesis.

Amyotrophic Lateral Sclerosis↗
PubMed1983

Lack of prominent compensatory polycythemia in traditional native Andeans living at 4,200 meters.

Red blood cell count (RBC), hemoglobin concentration ([Hb]) and hematocrit (Hct) were measured in 303 male Quechua children and adults, aged 6 to 57 years, living a lifestyle as traditional pastoralists and horticulturalists at a mean altitude of 4,200 m in the Southern Peruvian Andes. Values for RBC, [Hb], and Hct increased with age from middle childhood to young adulthood. However, among adults there was no significant association between age and any of these three parameters. Overall, there was approximately a 10-12% increase in the RBC, [Hb], and Hct above sea-level norms for all age groups. Mean corpuscular volume (MCV) and mean corpuscular hemoglobin (MCH) showed a slight but significant increase with age in children and adolescents, but the mean corpuscular hemoglobin concentration (MCHC) did not. We conclude that the study of highland Quechua Indians, living a traditional lifestyle as pastoralists and horticulturalists, does not support the long-held belief that altitude hypoxia provokes a dramatic compensatory polycythemia in healthy Andeans.

Adolescent↗
PubMed1983

A population genetic study of the Banks and Torres Islands (Vanuatu) and of the Santa Cruz Islands and Polynesian Outliers (Solomon Islands).

As part of a multidisciplinary survey of populations in the Banks and Torres Islands of Vanuatu and the Southern and Central Districts of the Solomon Islands, nearly 2,400 persons have been tested for ABO blood groups and a number of serum protein and red cell enzyme genetic marker systems. For the ABO system, the populations are characterized in general by high gene O and low gene B frequencies except in two of the Polynesian Outlier Islands, Rennell and Bellona, which have high frequencies of B. Among the serum proteins, several alleles have distributions indicating significant movement of people between islands. These include Albumin New Guinea and the transferrin alleles TfD1, and TfBLae, and TfB2. Similar specific alleles for red cell enzymes also show distributions reflecting interisland population movement as well as contact with persons from outside the southern Pacific region. Examples are ACPR1 in the acid phosphatase system, PGM31 and PGM71, PGM92, and PGM102, PGK4 and also HbJTongariki. The data available for 11 polymorphic systems were used to generate genetic distances. Of the four Polynesian Outlier Islands, Anuta is most remote genetically, with Rennell and Bellona also relatively isolated. The fourth Polynesian Outlier, Tikopia, occupies a position genetically close to the Melanesian populations of the Banks and Torres Islands and the southern Solomons. The history of early European contact and voyaging in the Pacific, as well as archaeological and linguistic evidence and local legends, indicate that significant movements of people occurred between islands and provided opportunities for genes to be introduced from Europeans, Africans, and Asians. The genetic marker studies give evidence for genes from all these sources, though at a low level. Despite this admixture, the Polynesian Outlier and Melanesian populations have preserved their own distinctive genetic patterns.

ABO Blood-Group System↗
PubMed1983

Epidemiological surveillance of amyotrophic lateral sclerosis and parkinsonism-dementia in the Commonwealth of the Northern Mariana Islands.

Amyotrophic lateral sclerosis (ALS) and parkinsonism-dementia (PD), two fatal neurological diseases of unknown cause, occur in high incidence among the Chamorro people of Guam, the largest and southernmost island within the Mariana archipelago. To reassess and extend our present epidemiological knowledge of these degenerative diseases in this focal geographical region, a systematic search for both disorders was conducted on the remaining inhabited islands of Rota, Tinian, Saipan, and the four remote islands of Anatahan, Alamagan, Pagan, and Agrihan within the Marianas chain. One case of ALS (on Saipan), 2 cases of PD (on Rota and Saipan), and 6 cases of parkinsonism without dementia (2 on Rota, 3 on Saipan, 1 on Tinian) were encountered among the approximately 17,000 inhabitants. No cases of either ALS, PD, or parkinsonism were found in the four remote Northern Islands. An additional 22 cases of ALS and 8 cases of PD were identified from reports of previous case-finding surveys, hospital records, and death certificates. Among Chamorros born on Rota, the average annual age-adjusted mortality rates of ALS per 100,000 population were 37.7 for the 15-year period 1956 to 1970 and 22.5 for the past decade, 1971 to 1980. Among Chamorros born on Saipan, the average annual mortality rates were 7.2 and 3.2 per 100,000, respectively, for the two periods. The mortality rates of PD were also significantly lower on Saipan than on Rota. In general, the age-adjusted mortality rates of ALS and PD on Rota were similar to those currently observed on Guam. Since the origins and current genotypic composition of Chamorros on all the Mariana Islands are indistinguishable, the strikingly lower mortality rates of ALS and PD on Saipan suggest that environmental factors are far more important than genetic factors in the pathogenesis of these diseases.

Adult↗
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

Intraneuronal aluminum accumulation in amyotrophic lateral sclerosis and Parkinsonism-dementia of Guam.

Scanning electron microscopy with energy-dispersive x-ray spectrometry was used to analyze the elemental content of neurofibrillary tangle (NFT)-bearing and NFT-free neurons within the Sommer's sector (H1 region) of the hippocampus in Guamanian Chamorros with amyotrophic lateral sclerosis and parkinsonism-dementia and in neurologically normal controls. Preliminary data indicate prominent accumulation of aluminum within the nuclear region and perikaryal cytoplasm of NFT-bearing hippocampal neurons, regardless of the underlying neurological diagnosis. These findings further extend the association between intraneuronal aluminum and NFT formation and support the hypothesis that environmental factors are related to the neurodegenerative changes seen in the Chamorro population.

Aged↗
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↗