Native American mitochondrial lineages in admixed populations from Chile: Detecting recent migrations during post-Columbian times using geographically restricted lineages

OBJECTIVES

To analyze the mitochondrial diversity in three admixed populations and evaluate the historical migration effect of native southern population movement to Santiago (capital of Chile). The intensity of migration was quantified using three mitochondrial lineages restricted to South-Central native groups.

METHODS

D-loop sequences were genotyped in 550 unrelated individuals from San Felipe-Los Andes (n = 108), Santiago (n = 217), and Concepción (n = 225). Sequence processing, alignment, and haplogroup inference were carried out, and different genetic structure analyses were performed for haplogroup frequencies and D-loop sequences.

RESULTS

The Native lineages B2i2, C1b13, and D1g were the most frequent haplogroups, especially in Santiago (71.8%). Despite the distance, this city showed a high-genetic affinity with southern populations, including Concepción (~500 km distant) and native groups, rather than with those from San Felipe-Los Andes (<100 km distant). In fact, there was a negative correlation between geographical and genetic distance among these cities (r corr = -0.5593, p value = 0.8387). Network analysis revealed shared haplotypes between Santiago, Concepción, and other southern populations. Finally, we found lineages from Concepción acting as ancestral nodes in the northern clade.

CONCLUSIONS

Considering the geographic distances from these cities, the results were not consistent with a model of genetic isolation by geographic distance, revealing the effects of a historical migration process from the south to the capital. We also show evidence of possible north-to-south migration during admixture onset in Concepción and in addition, we were able to identify previously unreported mitochondrial diversity in urban populations that became lost in Native groups post-European contact.

Latin Americans show wide-spread Converso ancestry and imprint of local Native ancestry on physical appearance

Historical records and genetic analyses indicate that Latin Americans trace their ancestry mainly to the intermixing (admixture) of Native Americans, Europeans and Sub-Saharan Africans. Using novel haplotype-based methods, here we infer sub-continental ancestry in over 6,500 Latin Americans and evaluate the impact of regional ancestry variation on physical appearance. We find that Native American ancestry components in Latin Americans correspond geographically to the present-day genetic structure of Native groups, and that sources of non-Native ancestry, and admixture timings, match documented migratory flows. We also detect South/East Mediterranean ancestry across Latin America, probably stemming mostly from the clandestine colonial migration of Christian converts of non-European origin (Conversos). Furthermore, we find that ancestry related to highland (Central Andean) versus lowland (Mapuche) Natives is associated with variation in facial features, particularly nose morphology, and detect significant differences in allele frequencies between these groups at loci previously associated with nose morphology in this sample.

Contrasting patterns of nuclear and mtDNA diversity in Native American populations

We report an integrated analysis of nuclear (autosomal, X- and Y-chromosome) short tandem repeat (STR) data and mtDNA D-loop sequences obtained in the same set of 22 Native populations from across the Americas. A north to south gradient of decreasing population diversity was observed, in agreement with a settlement of the Americas from the extreme northwest of the continent. This correlation is stronger with "least cost distances," which consider the coasts as facilitators of migration. Continent-wide estimates of population structure are highest for the Y-chromosome and lowest for the autosomes, consistent with the effective size of the different marker systems examined. Population differentiation is highest in East South America and lowest in Meso America and the Andean region. Regional analyses suggest a deviation from mutation-drift equilibrium consistent with population expansion in Meso America and the Andes and population contraction in Northwest and East South America. These data hint at an early divergence of Andean and non-Andean South Americans and at a contrasting demographic history for populations from these regions.

[Implementation of a safety and health planning system in a teaching hospital]

University Hospital "L. Sacco" had started in 2006 a two-year project in order to set up a "Health and Safety Management System (HSMS)" referring to the technical guideline OHSAS 18001:1999 and the UNI and INAIL "Guidelines for a health and safety management system at workplace". So far, the following operations had been implemented: Setting up of a specific Commission within the Risk Management Committee; Identification and appointment of Departmental Representatives of HSMS; Carrying out of a training course addressed to Workers Representatives for Safety and Departmental Representatives of HSMS; Development of an Integrated Informative System for Prevention and Safety; Auditors qualification; Inspection of the Occupational Health Unit and the Prevention and Safety Service: reporting of critical situations and monitoring solutions adopted. Short term objectives are: Self-evaluation through check-lists of each department; Sharing of the Improvement Plan among the departments of the hospital; Planning of Health and Safety training activities in the framework of the Hospital Training Plan; Safety audit.

Pre- and post-Columbian gene and cultural continuity: the case of the Gaucho from southern Brazil

OBJECTIVE

To investigate the evolutionary and demographic history of the Gaucho, a distinct population of southern Brazil, relating it to their culture, to assess possible parallel continuity.

METHODS

Six binary polymorphisms, an Alu insertion polymorphism (YAP) and 12 short tandem repeat loci in the non-recombining region of the Y-chromosome, as well as the sequence of the first hypervariable segment (HVS-I) of the mitochondrial DNA (mtDNA) control region were studied in 150 unrelated males born in the Pampa region of Rio Grande do Sul.

RESULTS

Comparison of the results with the other Brazilian and Uruguayan populations, as well as with their putative ancestors, indicated a stronger male Spanish influence than that observed elsewhere in Brazil, a former Portuguese colony. Extensive mtDNA analyses of their Amerindian component gave clear indications of the presence there of material from extinct (Charrua), as well as extant (Guarani) tribes.

CONCLUSIONS

The genetic analyses contributed in a significant way to reveal that the known cultural continuity between pre- and post-Columbian Pampa populations was also accompanied by an extraordinary genetic continuity.

Evolution, systematics, and phylogeography of pleistocene horses in the new world: a molecular perspective

The rich fossil record of horses has made them a classic example of evolutionary processes. However, while the overall picture of equid evolution is well known, the details are surprisingly poorly understood, especially for the later Pliocene and Pleistocene, c. 3 million to 0.01 million years (Ma) ago, and nowhere more so than in the Americas. There is no consensus on the number of equid species or even the number of lineages that existed in these continents. Likewise, the origin of the endemic South American genus Hippidion is unresolved, as is the phylogenetic position of the “stilt-legged” horses of North America. Using ancient DNA sequences, we show that, in contrast to current models based on morphology and a recent genetic study, Hippidion was phylogenetically close to the caballine (true) horses, with origins considerably more recent than the currently accepted date of c. 10 Ma. Furthermore, we show that stilt-legged horses, commonly regarded as Old World migrants related to the hemionid asses of Asia, were in fact an endemic North American lineage. Finally, our data suggest that there were fewer horse species in late Pleistocene North America than have been named on morphological grounds. Both caballine and stilt-legged lineages may each have comprised a single, wide-ranging species.

Ancient DNA simplifies the systematics of horses present in the New Word during the Pleistocene and reveals that the stilt- legged horse is native to the continent and not a Eurasian migrant.

[Self-evaluation of the quality of life of children aged 6 to 12 years old: analysis of the concept and development of a prototype tool]

The objective of this work was to assess the quality of life of children aged 6 to 12 years old. The authors present the different conceptual and operational steps which lead to the construction of a prototype tool. It was a generic tool composed of 63 items which covered the classically described areas of life. Its originality was due to the method of construction used which included children's involvement, to the pictorial representation of real-life situations for children, and to its adaptation for gender. The evaluation of this tool showed a good level of acceptability but statistical analysis revealed some metrological inadequacies leading to the reconsideration of the initial concepts and their methods of exploration. Therefore a new tool was constructed whose validation is presented in a second article in the next issue.

[Patterns of care in community mental health services in Lombardy]

OBJECTIVE

The analysis aims to study patterns of care of patients in contact with 5 Psychiatric Services in Lombardy. Four patterns have been identified long term-high users, non long term-high users, long term-non high users, non long term-non high users.

DESIGN

Data were provided by the regional Psychiatric Information System. The cohort of patients have been composed by 5,670 patients included in 1994 one year prevalence.

SETTING

Five Psychiatric Services (Merate, Treviglio, Crema, Desio, Castano Primo) with a total population of 610,184 inhabitants aged over 14. MAIN UTILISED MEASURES: Some sociodemographic and clinical variables have been taken into consideration for a descriptive analysis; a multinomial logistic regression model was used to identify the characteristics of patients associated with different patterns.

RESULTS

Long term-high users were 5.3%, i.e. a mean rate of 4.9/10,000 residents over 14, and absorbed 60% of resources, the absence of a partner was associated in regression analysis with this pattern. Non long term-high users were 1.2%, i.e. a mean rate of 1.1/10,000 residents over 14, and absorbed 7.8% of resources; age below 45, unemployment, absence of a partner, severe mental illness and first contact with Psychiatric Services in the period 1985-1989 were predictive variables. Long term-non high users were 23.4%, i.e. a mean rate of 21.6/10,000 residents over 14, and absorbed 18.1% of resources; age below 45, unemployment, living alone, absence of a partner, severe mental illness and first contact with Psychiatric Services before 1990 were predictive variables. Non long term-non high users were 70.1%, i.e. a mean rate of 64.8/10,000 residents over 14 and, absorbed 18.1% of resources.

CONCLUSIONS

Data show that on the whole the activity of Psychiatric Services is addressed to most serious patients, though considerable differences between Psychiatric Services utilisation may be found. This study highlights the importance of a regional Psychiatric Information System, that allows the monitoring in time and in the regional territory of patterns of care.

Effect of aprotinin on insulin sensitivity in non-insulin-dependent diabetes mellitus

It has been suggested that kallikrein-kinin system may influence carbohydrate metabolism via a kinin-mediated increment of insulin-mediated glucose uptake. To evaluate the effect of acute inhibition of the kallikrein-kinin system on insulin sensitivity, a randomized, placebo-controlled, double-blind study was performed in 15 male non-insulin-dependent diabetic patients. After basal evaluation of insulin sensitivity with a 2-h euglycaemic hyperinsulinaemic clamp (40 mU m-2 min-1), patients were infused either with aprotinin (200,000 U.I.C. as intravenous bolus injection) or placebo (10 ml isotonic saline) in a cross-over fashion, at 1 week intervals. After both saline and aprotinin infusions, insulin sensitivity was reassessed by continuing the euglycaemic hyperinsulinaemic clamp for a further 1 h. Resulting data showed that aprotinin significantly improved total glucose uptake (from 16.2 +/- 2.9 mumol kg min-1 to 20.6 +/- 4.9 mumol kg min-1 p < 0.01), and decreased metabolic clearance rate of insulin (from 586 +/- 57 ml m-2 min-1 to 442 +/- 155 ml m-2 min-1, p < 0.05). Thus, in spite of the suggested positive effects of kinins on insulin-mediated glucose uptake, acute inhibition of the kallikrein-kinins system resulted in a paradoxical increment of insulin sensitivity, which was probably mediated by the reduced metabolic clearance rate of insulin.

Ambulatory blood pressure normality: results from the PAMELA study

OBJECTIVE

To determine ambulatory and home blood pressure means and distributions in relation to clinic blood pressure in a general population.

METHODS

We obtained a random sample of 2400 subjects stratified by sex and 10 year age groups to be representative of residents aged 25-64 years of the city of Monza. Participation rate was 69% (1651 subjects). Blood pressure measurements consisted of clinic blood pressure (average of three measurements, sphygmomanometry), home blood pressure (average of morning and evening measurements, semiautomatic device) and ambulatory blood pressure (automatic readings at 20 min intervals, Spacelabs 90207). Clinic blood pressure was obtained both before and after home and ambulatory blood pressures. Data analysis did not include 213 subjects receiving antihypertensive drug treatment and was therefore limited to 1438 participants.

RESULTS

In the 1438 subjects, clinic, home and ambulatory blood pressure showed a normal-like distribution, with a taller peak and a narrower base for ambulatory than for home and clinic values. Clinic, home and ambulatory blood pressures were significantly related to each other (P always < 0.001). The means of the two clinic blood pressures obtained on consecutive days were superimposable (127.4 +/- 17.0/82.3 +/- 9.8 and 128.2 +/- 16.5/81.9 +/- 9.9 mmHg) and both were markedly higher than home and 24 h average blood pressures (8.2 mmHg), which were similar to one another. The differences between clinic and home or 24 h average blood pressure were similar in both sexes but increased with increasing age and clinic blood pressure values. The influence of clinic blood pressure values on the clinic-ambulatory or clinic-home blood pressure differences was more important than age. Although higher than the 24 h average value, daytime average blood pressure was also lower than clinic blood pressure. Night-time blood pressure was markedly lower than the daytime value in both sexes and at all ages.

CONCLUSION

Data from a large and unbiased sample of a general population show that home and 24 h or daytime average blood pressures are much lower than clinic blood pressure. The relatively close correlation between blood pressure values measured with the different methods used has allowed calculation of home and ambulatory blood pressure values corresponding to the accepted upper limit of normality of clinic blood pressure (140/90 mmHg). The upper limit of normality for the population was for both home and ambulatory blood pressures in the range 120-130 and 75-81 mmHg for systolic and diastolic values, respectively, with slight differences depending on sex and age. Taking 140/90 mmHg as the upper normal limit of the population is therefore an error that leads to individuals whose home or ambulatory blood pressures are high being considered as normotensive.

Effect of aldose reductase inhibition on glutathione redox status in erythrocytes of diabetic patients

Diabetic patients undergo a chronic oxidative stress. This phenomenon is demonstrated by low levels of reduced glutathione (GSH) levels. The NADPH used by glutathione reductase for the reduction of oxidized glutathione (GSSG) to GSH is also used by aldose reductase for the reduction of glucose to sorbitol through the polyol pathway. The competition for NADPH could be responsible for the decreased glutathione levels found in non-insulin-dependent diabetic patients. For this purpose, we investigated the effect of polyol pathway inhibition on the glutathione redox status in these patients. We measured GSH and GSSG levels in erythrocytes of non-insulin-dependent diabetic patients (n = 15) before and after 1 week of treatment with placebo, followed by 1 week of treatment with an aldose reductase inhibitor (tolrestat 200 mg/dl). We found lower GSH levels (7.7 +/- 1.4 mumol/g hemoglobin [Hb]), higher GSSG levels (0.35 +/- 0.09 mumol/g Hb), and lower GSH/GSSG ratios (23.9 +/- 7.7) in diabetics compared with controls (n = 15; 9.8 +/- 0.8 mumol/g Hb, P < .001; 0.17 +/- 0.02, P < .001; and 58.3 +/- 9.1, P < .001, respectively). We did not demonstrate any statistical difference after 1 week of treatment with placebo. In contrast, the treatment with tolrestat induced a significant increase in GSH (8.9 +/- 0.7 mumol/g Hb, P < .01), a decrease in GSSG (0.25 +/- 0.06 mumol/g Hb, P < .02), and an increase in the GSH/GSSG ratio (37.3 +/- 8.4, P < .01). These data strongly support the hypothesis that the polyol pathway plays an important role in the impairment of the glutathione redox status in diabetic patients.

Ambulatory and home blood pressure normality: the Pamela Study

Ambulatory blood pressure monitoring (ABPM) is increasingly used in the clinical evaluation of hypertension. However, a number of limitations restrict its routine use. One of the limitations is a lack of definite conclusions about ambulatory blood pressure normality, because of the shortcomings of previous studies on this issue. In the present study we describe a survey from a large sample of subjects within the age range of 25-64 years. It was found that 24-h average systolic and diastolic blood pressures are markedly lower than clinic blood pressure, and for daytime average and home blood pressure as well. In addition, it was found that the clinic ambulatory or home blood pressure disparity is related to the baseline clinic blood pressure (i.e., it increases with increasing clinic blood pressure values) and that the three pressures (ambulatory, home, clinic) are closely related to each other, thereby allowing the application of correction factors to obtain information on ambulatory or home blood pressure normality. This results in an upper normality limit for 24-h average blood pressure and home blood pressure of around 120 mm Hg systolic and 77 mm Hg diastolic pressure.

Octreotide, a somatostatin analog, reduces insulin secretion and increases renal Na+ excretion in lean essential hypertensive patients

The influence of insulin on renal Na+ excretion is still subject to debate. In order to evaluate the effect of insulin suppression on Na+ excretion, 20 never-treated essential hypertensive men and 8 normotensive men were studied. All subjects had a body mass index < 27 kg/m2. Both the glucose and the lipid metabolisms were normal. After 2 weeks under normal NaCl intake (120 mEq NaCl daily), either octreotide, a somatostatin analog, or vehicle were infused in a forearm vein during acute volume expansion (0.30 mL/kg/min isotonic saline given intravenously over a period of 30 min). A double-blind randomized cross-over design was followed, and each subject was given both infusions at a 1 week interval. Blood and urine samples were taken at times--60, 0, 30, 60, 90, 120, 180, 240, and 300 min. Our data showed that octreotide significantly lowered insulin levels in both hypertensives (from 12.2 +/- 2.4 microU/mL at time 0 to undetectable values at time 30 and 60 min) and normotensives (from 11.5 +/- 2.8 microU/mL at time 0, to undetectable values at time 30 and 60 min). Compared to saline infusion alone, octreotide significantly increased Na+ excretion in both hypertensives and normotensives (saline + octreotide v saline alone = P < .05 at time 60 and 90 min). In conclusion, octreotide enhanced the natriuretic response to intravenous Na+ load in both hypertensives and normotensives. The increase in urinary Na+ was accompanied by a significant decrease in plasma insulin levels.

[Drop in cardiovascular and coronary mortality in Lombardia, 1969-1987. Evaluation of reliability of the estimates and possible explaining hypothesis]

The results of the present analysis indicate, from 1969 to 1987, a sharp and stable decline in cardiovascular (CVD) mortality in Italians aged 35-74 years (37.6% in males 53.6% in females). These trends were responsible for consistent reductions of total mortality (27.5% and 38% in the two gender groups, respectively), and for the increase of life expectancy. The decrease involved the two major components of CVD mortality, i.e. coronary heart disease (CHD) (23% in males and 44% in females) and cerebrovascular diseases (Stroke) (42.6% in the former and 51% in latter gender group). All these mortality decrements have been higher in the Lombardia Region. Comparing age-adjusted mortality rates in 1968 and 1987, it was possible to estimate that 23,040 deaths were saved in one year among the residents of this northern part of Italy, and the decrease of CHD mortality was responsible for about 30% of the total national decrement of CHD deaths, within comparable age strata. This is attributable both to the higher rates registered at the beginning of the studied period, and to the sharper decline observed. The social impact, in terms of reduction of deaths, was prominent for males. Among the northern male population, the amount of prevented deaths due to CHD and Stroke was equivalent (2072 vs 2172). Data from a MONICA Collaborating Center, located in the region--Area Brianza--, allow us to estimate, for coronary diagnoses reported on death certificates in the 1980s, acceptable levels of accuracy (Cohen's Kappa of .35, with 99% CI .27-.43) and sensitivity (87%). In comparison with earlier estimates carried out in the late 1970s, it is possible to hypothesize an increase of sensitivity over time for certified myocardial infarction diagnoses, which could have contributed to the underestimation of the observed decrements. In dealing with estimates of the reasons for these declines, only suggestions could be addressed because results of specific and comprehensive studies are not presently available. By comparing MONICA data with the results obtained in earlier surveys, it is possible to estimate that about 20 to 30% of the CHD decline, which occurred in the Region, might be attributed to the decrease of in-hospital coronary case-fatality. Moreover, major coronary risk factors (total cholesterol, blood pressure and cigarette smoking) show parallel positive changes, but their contribution in predicting the CHD downfall is difficult to evaluate on the basis of existing data.(ABSTRACT TRUNCATED AT 400 WORDS)

Does mild autonomic neuropathy affect atrial natriuretic factor regulation in diabetic hypertensive patients?

The effect of postural changes on plasma atrial natriuretic factor (ANF) levels was investigated in 16 diabetic hypertensives (eight with and eight without mild autonomic neuropathy) and in 10 hypertensives. The presence of renal damage or secondary hypertension was excluded. All diabetic patients were in good metabolic control. In upright position, the mean levels of plasma ANF were of 23.1 +/- 7.6 pg/mL in neuropathic diabetic hypertensives, 24.2 +/- 8.3 pg/mL in diabetic hypertensives, and 21.6 +/- 6.7 in essential hypertensives. Percentage decrease observed after the assumption of supine position was 47 +/- 18, 50 +/- 10, and 46 +/- 13, respectively. No significant difference was found between hypertensives and diabetic hypertensives, even in the presence of mild autonomic neuropathy. Plasma ANF response to postural changes was similar in all groups.