A correlation of tooth wear and age among modern Igloolik eskimos.

The level of molar wear can be estimated reliably by measuring the cusp height. A correlation between age and the level of molar wear, expressed by a normalizing index (TWI) of cusp height, was found to exist in a sample of modern Igloolik Northwest Territories Eskimos. Not only was it possible to derive linear regression models to test the degree of correlation in the sample of 46 female and 39 male maxillary casts of Igloolik Eskimos, but the models were capable of accurately predicting the age of natives of the neighboring Hall Beach community. Sexual dimorphism in molar wear, perhaps attributable to differential bruxism, was demonstrated for the Igloolik sample. Based on the combined estimate of slopes for each maxillary molar pair for females and males, it was discovered that the male maxillary molars are worn approximately 30% more rapidly than female maxillary molars.     

A population study of the jugular foramen bridging of the human cranium

The author previously proposed a simple standard for diagnosing the jugular foramen bridging in man. The incidence of this bridging trait was investigated according to that standard in nine cranial series of East Indians, Micronesians, Japanese, Ainu, Mongols, Aleuts, Alaskan Eskimos, Canadian Eskimos, and Ontario Iroquois. No sex difference in incidence of the trait was recognized. Side difference in trait incidence was also slight but was statistically significant in the combined series of all the population samples examined. The bridging trait occurred more frequently on the right side than on the left side. Occurrences of the bridging trait were definitely associated between sides. Incidence of the trait was less in East Indians, Ontario Iroquois, and Micronesians, but greater in Alaskan Eskimos and Canadian Eskimos, the incidences in Japanese, Ainu, Aleuts, and Mongols being intermediate. The differences in trait incidence among the nine population samples were considered to reflect the differences in genetic compositions of these specific populations.     

Health of Igloolik Eskimos and changes with urbanization

Medical examinations were carried out on 422 Igloolik Eskimos in 1969 and again on 485 two years later. In 130 adult men and women scen on both occasions body weight and skinfold thicknesses were relatively unchanged but there were significant increases of both systolic and diastolic blood pressure, the basis of which is not established but an increase in dietary salt is hypothesized. In 280 children the overall incidence of otitis media was approximately 30% but children breastfed for at least 4 months had less than half the incidence of nonbreastfed children. In multiparous women up to age 50 duration of breastfeeding of a child was directly related to the interval until the next conception.     

Group-specific component, alpha1-antitrypsin and esterase D in Canadian Eskimos.

Three genetic markers - group-specific component (Gc), alpha1-antitrypsin, and esterase D - were examined in a population of Eskimos from Igloolik in the eastern Canadian Arctic. Gc and esterase D were found to be polymorphic. In addition to the common Gc types, an anodal variant called Gc Igloolik was found, probably identical to previously reported Gc Eskimo. Gene frequencies were Gc1: 0.6524, Gc2: 0.3373, GcIgl: 0.0104, for 338 Eskimos. Genetic types of alpha1-antitrypsin (Pi types) were mostly M, with two MS sibs who were half Caucasian, in 170 Eskimos. Frequencies of the esterase D allele in 336 Eskimos were EsD1: 0.7083, EsD2: 0.2917. The frequencies of Gc2 and EsD2 are both higher than are found in Caucasian populations.     

Form and patterning of anterior tooth wear among aboriginal human groups

Form and severity of dental attrition was assessed in aboriginal human groups including hunter-gatherers (Eskimos, Australians) and those with dependence to a varying degree on food production (Southwest U.S. and Ohio American Indians). Wear on anterior teeth was both relatively and absolutely greater in the hunter-gatherers, as indicated by comparisons of wear on anterior and posterior teeth which come into occlusion at roughly the same time. Distinct differences in form of anterior wear were also apparent: The hunter-gatherers exhibited steadily increasing incidences of labially rounded wear with greater functional age, while the food-producing groups showed little or no rounding but instead high frequencies of heavily cupped wear (especially in those with premature loss of posterior teeth). These differences were attributed to nonmasticatory utilization of the front teeth in hunter-gatherers and to employment of the anterior teeth in masticatory (grinding) activities necessitated by large-scale molar loss in food producers.     

Mercury in Fish-eating Communities of the Andean Amazon,Napo River Valley,Ecuador

This exploratory study aimed to examine the relationship between fish eating habits, human mercury levels, and mercury levels in fish in three communities of the Napo River Valley, Ecuadorian Andean Amazon, a region without gold mining but with significant deforestation and volcanic soils with naturally high mercury levels. By recognizing the politicoeconomic factors which cause deforestation, the cultural factors which influence diet, and the biogeochemical factors which contribute to mercury levels, this study employs an ecosystem approach. Interviews on diet were conducted, hair samples from 99 individuals were collected, and samples of commonly eaten fish were taken. Samples were analyzed using cold vapor atomic fluorescence spectrometry (CVAFS). Two rural communities were found to have higher fish consumption and hair mercury levels (8.71 μg/g and 5.32 μg/g) as compared to an urban community (1.87 μg/g). A sequential analysis of hair established mercury levels by month. No seasonal tendencies were noted. Piscivorous fish (0.36 μg/g) were found to be more contaminated in mercury than herbivorous fish (0.05 μg/g). The study shows that sociocultural factors are important in determining mercury exposure. The two village communities consume different species of fish with different frequencies, leading to differential exposure and mercury concentrations in hair samples. The levels of mercury in these two villages were similar to those found in Brazil where neurobehavioral tests showed a correlation between these relatively low levels of mercury and decreased psychomotor capacities. These findings are concerning and should be followed by further studies on the multiple factors that affect the health status of these exposed communities.     

Analysis of contingency table data on torus mandibularis using a log linear model

The hypothesized sexual difference in the incidence of torus mandibularis in Eskimoid groups, as well as age and group differences, was studied in two Northwest Territories Eskimo groups and in an Aleut group (examined by Moorrees). The data were analyzed using statistical methods new to the field of anthropology. The method analyzes data sampled from a multinomial distribution. A hierarchy of log linear models are fitted to the cell counts of a contingency table. An iterative proportional fitting procedure is used to obtain expected cell counts under each log linear model. The “goodness of fit” of each model is tested by the log likelihood ratio. This statistic can be partitioned into additive components such that differences between models can be tested. In this way a “best” model, from the hierarchy of models, is chosen. Among these three groups of Eskimos, the incidence of torus mandibularis was not affected by sex but was affected by age and was different between the three groups.     

Mandibular torus morphology

The morphology of the mandibular torus was examined, and comparisons were made between a Medieval Norse skeletal population from Greenland and a 14th to 17th century Greenland Eskimo skeletal series. Three parameters were analyzed: degree of development (on a 4-point scale), position and length, and surface morphology according to the number of knobs, or lobuli. It was found that the Eskimos have a high frequency of weakly developed tori and no cases of the extreme development, while over 20% of the Norsemen had tori in the “extreme” category. The Norse torus was generally found to be longer than that of the Eskimos, and both groups exhibited a slight asymmetry between the sides, the torus on the left side tending to be longer and more forward in position than the right. A great difference was found in surface morphology. The Norse torus is in general very irregular, while the Eskimo torus is rather smooth. These differences are believed to be genetically determined.     

Beneficial effect of fish oil on blood viscosity in peripheral vascular disease.

Reports suggest that the low incidence of ischaemic heart disease in Greenlandic Eskimos is related to the effect of a diet rich in eicosapentaenoic acid on platelet reactivity and plasma lipid concentrations. A double blind randomised investigation was therefore conducted of the effects on blood viscosity of dietary supplementation with an oil rich in this fatty acid (1.8 g/day, given as fish oil) and an eicosapentaenoic acid poor oil (as corn/olive oil) in patients with peripheral arterial disease. A statistically significant reduction in whole blood viscosity was observed at seven weeks in those patients receiving the eicosapentaenoic acid rich oil. No changes in plasma viscosity, haemoglobin concentration, packed cell volume, or platelet count were seen. A significant fall in plasma triglyceride concentration was also noted only in the patients receiving oil rich in eicosapentaenoic acid; plasma concentrations of cholesterol and high density lipoprotein cholesterol were unchanged. It is concluded that rheological changes that result from a diet rich in eicosapentaenoic acid may contribute to the suggested protective effects of such a diet against arterial disease and that such changes are of potential therapeutic importance in established arterial disease.     

Ecology of the ringed seal (Pusa hispida) from the Bering Strait in the late Holocene

The combined use of analysis of stable isotopes and archeozoological methods with respect to osteological material from an ancient Eskimo settlement (2370-810 yr BP) made it possible to reveal the main distinguishing features of ringed seal in the past. On the basis of the data obtained, we suppose that in the late Holocene in the Bering Strait, there were seals of two different ecotopes: those reproducing on fast ice and those on pack ice differing not only in habitats, but also in the proportion of various food items in the diet. The ringed seals caught by ancient Eskimos during their life had a mixed diet consisting of crustaceans and fish, but in most individuals, a shift towards fish eating was observed. No significant changes in the feeding related to individual age were recorded. The influence of feeding type on body size was shown: bigger, mature individuals occupied higher trophic positions.     

Interproximal grooving and task activity in Australia

Interproximal grooving was recorded in 85 nineteenth century aboriginal skulls from Swanport in South Australia. One or more grooved teeth were noted in 41% of individuals, but the frequency of grooving in males was twice that in females. Distal surface grooving was noted in 93 teeth in contrast to only five instances of mesial grooving. The lesions were similar in appearance to those reported in many other populations--confined primarily to the premolar-molar region, located at the cementoenamel junction, directed horizontally, and usually clean-cut and free of caries. Stripping of animal sinews between the clenched posterior teeth has been recorded on film as a common task activity in traditional aboriginal society. In our opinion, task activity and not toothpicking was the likely cause of the observed interproximal grooving in the aboriginals.     

Chronobiology of coronary risk markers in Greenland Eskimos: a comparative study with Caucasians residing in the same Arctic area.

We report a comparison of fibrinolytic variables between 10 Caucasians on a predominantly European diet and 10 Greenland Eskimos on a traditional Inuit diet containing a substantial amount of fish and sea animals. We studied the diurnal variation in tissue type plasminogen activator (t-PA) and plasminogen activator inhibitor (PAI) antigens and activities during a 24-h period. Blood samples were taken every 4 h. The variations of the sinusoidal curves were evaluated by the Friedman chi 2 test. t-PA and PAI-1 antigen in plasma fluctuated significantly during the 24 h (Eskimos p less than 0.00007 and p less than 0.0007; Caucasians p less than 0.00003 and p less than 0.02), with a peak in the early morning and a nadir in the afternoon. This also held true for PAI activity (Eskimos p less than 0.0008; Caucasians p less than 0.01), whereas t-PA activity showed an inverse but still significant pattern (Eskimos p less than 0.006; Caucasians p less than 0.0008). Amplitudes, areas underneath, and overall medians of the sinusoidal curves did not deviate between the two groups with respect to t-PA and PAI. In contrast to the significant variation of t-PA and PAI, the plasma concentrations of fibrin degradation products (D-Dimer), a measure of effective fibrinolysis, remained constant during the 24 h, and the absolute differences between groups did not reach statistical significance. These findings suggest that circadian variation of fibrinolytic activators and inhibitors is a basic biologic phenomenon, which is not affected by life-style, dietary habits, or ethnic differences.(ABSTRACT TRUNCATED AT 250 WORDS)     

Apolipoprotein H genetic variability in the population of Krk Island,Croatia

Apolipoprotein polymorphisms are emerging as suitable markers for the study of the formation of human populations. In contrast to the data available for apolipoprotein E, the data regarding apolipoprotein H (protein, apoH; gene, APOH) variations are only beginning to accumulate. By blood plasma isoelectric focusing and immunoblotting, we analyzed the distribution of apoH phenotypes in 397 individuals (192 males; 205 females) from seven villages of an autochthonous population of the eastern Adriatic island of Krk. APOH allele frequencies were: APOH*2 = 0.877, APOH*3 = 0.098, APOH*1 = 0.025, with the majority of the sample being homozygous. No significant differences between villages were observed. When these data were compared to those of other populations studied so far, a significant association between APOH allele frequencies and latitude was observed. We hypothesize that this association reflects differences in diet composition across different climatic zones.     

Chronobiology of Coronary Risk Markers in Greenland Eskimos: A Comparative Study with Caucasians Residing in the Same Arctic Area

We report a comparison of fibrinolytic variables between 10 Caucasians on a predominantly European diet and 10 Greenland Eskimos on a traditional Inuit diet containing a substantial amount of fish and sea animals. We studied the diurnal variation in tissue type plasminogen activator (t-PA) and plasminogen activator inhibitor (PAI) antigens and activities during a 24-h period. Blood samples were taken every 4 h. The variations of the sinusoidal curves were evaluated by the Friedman χ² test. t-PA and PAI-1 antigen in plasma fluctuated significantly during the 24 h (Eskimos p < 0.000007 and p < 0.0007; Caucasians p < 0.00003 and p < 0.02), with a peak in the early morning and a nadir in the afternoon. This also held true for PA1 activity (Eskimos p < 0.0008; Caucasians p < O.Ol), whereas t-PA activity showed an inverse but still significant pattern (Eskimos p < 0.006; Caucasians p < 0.0008). Amplitudes, areas underneath, and overall medians of the sinusoidal curves did not deviate between the two groups with respect to t-PA and PAL In contrast to the significant variation of t-PA and PAI, the plasma concentrations of fibrin degradation products (D-Dimer), a measure of effective fibrinolysis, remained constant during the 24 h, and the absolute differences between groups did not reach statistical significance. These findings suggest that circadian variation of fibrinolytic activators and inhibitors is a basic biologic phenomenon, which is not affected by life-style, dietary habits, or ethnic differences. Furthermore, the lack of diurnal variation in D-Dimer raises the question of whether there is a causal relationship between low morning activities of t-PA and the frequent onset of myocardial infarction at that time of day, as suggested by several authors.     

Frontal sinus size in Eskimo populations

The frontal sinuses of 143 Eskimo skulls from two sites in the Hudson Bay region of Canada were examined radiographically. No between-site or sex differences were noted in the size of the sinuses. On average, the sinuses are small and often bilaterally absent. The Canadian samples have smaller sinuses than reported for Alaskan Eskimos or American Indian groups.     

Analysis of admixture and genetic structure of two Native American groups of Southern Argentinean Patagonia

Argentinean Patagonia is inhabited by people that live principally in urban areas and by small isolated groups of individuals that belong to indigenous aboriginal groups; this territory exhibits the lowest population density of the country. Mapuche and Tehuelche (Mapudungun linguistic branch), are the only extant Native American groups that inhabit the Argentinean Patagonian provinces of Río Negro and Chubut. Fifteen autosomal STRs, 17 Y-STRs, mtDNA full length control region sequence and two sets of Y and mtDNA-coding region SNPs were analyzed in a set of 434 unrelated individuals. The sample set included two aboriginal groups, a group of individuals whose family name included Native American linguistic root and urban samples from Chubut, Río Negro and Buenos Aires provinces of Argentina. Specific Y Amerindian haplogroup Q1 was found in 87.5 % in Mapuche and 58.82 % in Tehuelche, while the Amerindian mtDNA haplogroups were present in all the aboriginal sample contributors investigated. Admixture analysis performed by means of autosomal and Y-STRs showed the highest degree of admixture in individuals carrying Mapuche surnames, followed by urban populations, and finally by isolated Native American populations as less degree of admixture. The study provided novel genetic information about the Mapuche and Tehuelche people and allowed us to establish a genetic correlation among individuals with Mapudungun surnames that demonstrates not only a linguistic but also a genetic relationship to the isolated aboriginal communities, representing a suitable proxy indicator for assessing genealogical background.     

The prostacyclin/thromboxane balance is favourably shifted in Greenland Eskimos

The rare incidence of cardiovascular disease in Eskimos has been ascribed to their diet rich in eicosapentaenoic acid (EPA, C20:5n-3) and hence a possible formation of trienoic prostanoids. In this study we compare endogenous formation of prostacyclin (PGI), which is formed by the endothelial cell, and thromboxane (TXA), which is formed by platelets in 20 Eskimos and 20 age and sex matched Danish controls by measurement of the main urinary metabolites. Considerable formation of bioactive PGI3 from dietary EPA was shown in Eskimos, which was barely detectable in the controls. Furthermore synthesis of PGI2 was significantly higher in Eskimos in spite of a markedly lower arachidonate content in membrane lipids. In contrast formation of TXA2,3 was lower in Eskimos as compared to the Danish controls. We conclude, that the balance between PGI and TXA, which may regulate the interaction of platelet and vessel wall, is favourably shifted in Greenland Eskimos to an antithrombotic state.     

Odontometric profile of a prehistoric southeastern Florida population

This study analyzes and compares the dental size variation and sexual dimorphism of the Highland Beach Mound people, a late southeastern prehistoric aboriginal Florida population (ca. 800-1200 AD) with a somewhat earlier midwestern group (ca. 200-800 AD) and an Archaic sample (ca. 4160-2558 BC). The lengths and breadths of maxillary and mandibular permanent teeth of 99 individuals were measured, and crown surface areas were calculated for the molars. Results indicated that there was little sexual dimorphism. Only the mesiodistal dimensions of the upper P2 and lower C were significantly different at the P less than 0.05 level. In terms of dental size, what appears to be a chronologically based reduction in most points of comparison was seen in all three groups, with the exception of the molars, which were larger in the Highland Beach sample than in the earlier Schultz Mound.     

An epidemiologic study of hypertension in Newfoundland

The distribution of arterial blood pressure (BP) values of 1499 adult inhabitants of four Newfoundland communities was surveyed. Mean age- and sex-adjusted BP scores were found to be higher in each of three fishing villages than in the logging and mining community, Badger, in the central part of the province. It is postulated that the observed differences may be caused by environmental factors. The prevalence of individuals with probable essential hypertension (diastolic BP > 100 mm. Hg) in individuals over 50 years of age was found to be three times higher in the island community, Fogo, than in Badger. In both communities less than one third of those with probable hypertensive disease had received treatment.