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Biomedical subjects

R M Garruto

Publications and source records attributed to R M Garruto.

At least 109 records · Page 6Linked to original sources

Amyotrophic lateral sclerosis and parkinsonism-dementia among Filipino migrants to Guam.

Amyotrophic lateral sclerosis (ALS) has occurred in 9 Filipino migrants to Guam 1 to 29 years after their arrival and parkinsonism-dementia (PD) in 2 migrants 13 and 26 years after arrival. Seven additional Filipino patients developed more classic Parkinson disease (P) 5 to 24 years after their migration to Guam. Furthermore, 10 part-Filipino patients who were born on Guam of Filipino and Chamorro parentage developed ALS, while 6 such part-Filipino patients developed PD. An estimate of the average annual crude mortality rate for ALS among Filipino migrants was approximately six times that of the continental United States, yet half that currently observed among Chamorros living on Guam. A majority of all migrant patients were born in northwestern Luzon in the Philippine Islands, indicating the desirability of an intensive field epidemiological investigation in that area.

Adult↗

Brain destruction alone does not elevate brain aluminum.

Graphite furnace atomic-absorption spectroscopy was used to measure aluminum concentrations in brain samples from 33 patients dying from a variety of neurologic diseases. Four samples from patients dying of nonneurologic causes also were studied. Nine samples (one from each of nine patients) of Creutzfeldt-Jakob disease brain contained normal amounts of aluminum. Aluminum was increased in 9 of 18 brain specimens with seven different pathologic processes. This included three of seven Alzheimer disease, two of three Huntington disease, two of two Parkinson disease, one of one progressive supranuclear palsy, one of one acoustic neuroma, one of two cerebrovascular disease, and one of two Guamanian amyotrophic lateral sclerosis (ALS). Aluminum was normal in the remaining samples (four normal, two ALS, one multiple sclerosis, one Pick disease, and two Guamanian parkinsonism-dementia). The significance of high aluminum values is not clear, but the normal values from the Creutzfeldt-Jakob cases imply that neuronal destruction per se need not lead to accumulation of aluminum in the brain.

Adolescent↗

ELISA antibodies to cysticerci of Taenia solium in human populations in New Guinea, Oceania, and Southeast Asia.

The presence of ELISA antibodies to cysticerci of Taenia solium was surveyed in populations of New Guinea, Micronesia, and several areas of Southeast Asia. It is confirmed that cysticercosis in New Guinea remains limited to the primary Wissel Lakes focus in Irian Jaya, where the disease was introduced by the importation of infected pigs, and that it has not spread to populations east or south of the Wissel Lakes, or to Papua New Guinea. On the island of Bali, Indonesia, 21% of sera were positive from one village where pigs are especially numerous, whereas in Sumatra, Indonesia, only 3%-4% of sera were positive. In Singapore, there was a higher proportion of positive sera among the Chinese (13%) than among the Indian (5%) or Malay (3%) Moslems. From 3 to 13% of sera from populations in Micronesia, Burma, Vietnam, and the Philippines were also found to react with cysticercus antigen. However, the problem of incomplete ELISA specificity raises the possibility that in areas not known to be endemic for T. solium, seropositive results could represent either subclinical infection with cysticerci or crossreactivity to other parasitic infections.

Antibodies↗

Amyotrophic lateral sclerosis among Chamorro migrants from Guam.

Amyotrophic lateral sclerosis (ALS), which occurs in unusually high incidence among the Chamorro people on the island of Guam, has developed in 28 Chamorro migrants--24 of whom had onset in the United States, Japan, Germany, or Korea--after periods of absence from Guam of 1 to 34 years. Thus, the latency period for the disease, if caused by environmental factors on Guam, may be over three decades. Four further patients developed ALS within 1 to 14 years of their return to Guam after long-term residence in the continental United States. The minimum exposure time to environmental variables on Guam, based on age at migration, was 18 years, and all patients had spent their childhood and adolescence on Guam. Estimates of crude mortality rates for ALS from these data are considerably higher than for the United States population, and lower than the ALS mortality rates for nonmigrant Chamorros on Guam.

Adult↗

Early acquisition of cytomegalovirus and Epstein-Barr virus antibody in several isolated Melanesian populations.

Significant differences among diverse human populations have been found in the seroepidemiology of cytomegalovirus (CMV) and Epstein-Barr virus (EBV). The present report documents a very high rate of early acquisition of antibody to CMV and EBV among three remote populations living in the Eastern Highlands of Papua New Guinea, the Solomon Islands, and the New Hebrides, respectively. These three genetically distinct populations, living in widely different ecologies and social settings, each had the same pattern of early acquisition of infection with both viruses. It is suggested that spread of CMV and EBV is determined by patterns of interpersonal contact as well as by the prevalence of virus-shedders. The large number of handlers of each infant in these studied groups appears directly related to the early acquisition of these viruses.

Adolescent↗

The distribution and prevalence of group A arbovirus neutralizing antibodies among human populations in Southeast Asia and the Pacific islands.

Plaque reduction neutralization tests, using five group A arboviruses (chikungunya, Ross River, Getah, Bebaru and Sindbis), were done on sera from human populations in 44 Southeast Asia and Pacific island localities. Specificity of the plaque neutralization test was determined by examining convalescent sera from patients with known alphavirus infections. Chikungunya-specific neutralizing antibodies were demonstrated in sera of persons living in South Vietnam, Northern Malaysia, Indonesia (Kalimantan and Sulawesi), as well as Luzon, Marinduque, Cebu and Mindanao islands in the Philippines. Evidence of Ross River virus infection was found among populations living in West New Guinea and Papua New Guinea mainland, the Bismark Archipelago, Rossel Island and the Solomon Islands. There appeared to be no geographic overlap in the distribution of chikungunya and Ross River viruses, with the separation in their distribution corresponding with Weber's line in the Pacific. Sindbis neutralizing antibodies were found in 7 of 21 populations sampled, but in general the prevalence of infection was low. Four sera, from Vietnam, Malaysia and Mindanao gave monospecific reactions with Getah virus. No evidence of specific Bebaru virus infection was detected. The epidemiology of these five alphaviruses in Southeast Asia and the Pacific islands is discussed.

Adolescent↗

Morphological growth and thorax dimensions among Tibetan compared to Han children, adolescents and young adults born and raised at high altitude.

BACKGROUND: Studies comparing the growth of indigenous high-altitude Aymara children and children of low-altitude European descent who have been born and raised at high altitude in the Andes have provided evidence for genetically-determined differences in thorax growth, as well as for population differences in height, weight and other measures of overall size. Comparable studies now can be undertaken in Asia because of the growing number of Han Chinese who have been born and raised at high altitude on the Qinghai-Tibetan Plateau. AIM: The study compares the growth of indigenous Tibetan children and children of Han descent who have been born and raised at the same high altitudes, and under similar socio-economic conditions. SUBJECTS AND METHODS: Measurements of stature, sitting height, weight, triceps and subscapular skinfolds, upper arm muscle area, transverse chest diameter, anterio-posterior chest diameter, and chest circumference were taken on 1439 Tibetan and Han males and females between the ages of 6 and 29 years who were born and raised 3200 m, 3800 m or at 4300 m in the high altitude province of Qinghai in western China. RESULTS: Han-Tibetan differences in body size do not occur systematically for any measurement, for any age group, or for either gender; nor is there a systematic pattern of body size differences between 3200 m and 4300 m. This indicates that there are no differences in general growth between the two groups at high altitude in Qinghai, although both groups grow more slowly than urban children at low altitude in China. On the other hand, Tibetan males possess significantly deeper chests than Han males, and Tibetan females possess significantly wider chests than Han females. Tibetans of both sexes possess significantly larger chest circumferences than Han males and females. CONCLUSIONS: Although genetic similarities cannot be ruled out, comparable dietary stress is a likely explanation for the similar and slow morphological growth of Han and Tibetans at high altitude. However, Han-Tibetan differences in thorax dimensions are likely a consequence of population (genetic) differences in the response to hypoxia during growth.

Adolescent↗

Analysis of the neurotoxic plasticizer n-butylbenzenesulfonamide by gas chromatography combined with accurate mass selected ion monitoring.

The plasticizer, n-butylbenzenesulfonamide (NBBS), is reported to be neurotoxic when inoculated intracisternally or intraperitoneally into rabbits. Because NBBS is commonly used in the production of polyamide (nylon) plastics and is soluble in water, the disposal of NBBS-containing plastics in landfill sites could result in NBBS appearing in the leachate. Further, NBBS could also be leached from packaging into their contents. To allow us to examine the risks posed by NBBS in the environment, we have developed a quantitative assay for this compound. The assay employs a one-step extraction into dichloromethane followed by gas chromatography with accurate mass selected ion recording. The assay incorporates [13C6]NBBS as an internal standard to allow precise quantitation, and four separate ion chromatograms are recorded. NBBS was found in some Australian domestic solidwaste landfill leachate (from less than 0.3 to 94.6 ng/mL), but ground water in the vicinity of a landfill had only trace quantities of NBBS. NBBS was also quantitated in some bottled and cask wines, and levels varied from not detected to 2.17 ng/mL (n = 14). Additional studies are required to assess the public health risks associated with the use of NBBS as a plasticizer.

Gas Chromatography-Mass Spectrometry↗

The nucleus basalis of Meynert in parkinsonism-dementia of Guam: a morphometric study.

The nucleus basalis of Meynert (nbM) was studied morphometrically in three Guamanians with parkinsonism-dementia (PD) and in two Guamanian and two non-Guamanian controls. Paraffin-embedded blocks of the nbM were serially sectioned (20 microns thick) at increments of 200 microns so that a total of 24 sections (eight each from the anterior, intermediate and posterior sectors of the nbM) were studied. The mean cell density was determined for each sector and the diameter of 50 neurons, randomly chosen in the region of apparent maximal density, was calculated. A decrease of the mean cell density, due to the loss of neurons with diameters larger than 20 microns, was found in the PD cases compared to the controls. Two PD patients exhibited striking neuronal loss (65-95%) with predominant involvement of the intermediate and posterior sectors, while the third case showed only minimal neuronal loss in these sectors (15-40%). In both Guamanian and non-Guamanian controls large neurons (diameters greater than or equal to 20 microns) exceeded small neurons while the reverse was true in all sectors of the nbM for the PD cases. These data, while confirming a previous study reporting neuronal loss in the nbM of PD patients, underline the importance of detailed morphometric analysis of the different sectors of the nbM to recognize those patients in whom lesions are not uniformly distributed.

Aged↗