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C Rengo

Publications and source records attributed to C Rengo.

At least 19 recordsLinked to original sources
PubMed2003

Identification of Native American founder mtDNAs through the analysis of complete mtDNA sequences: some caveats.

In this study, a detailed analysis of both previously published and new data was performed to determine whether complete, or almost complete, mtDNA sequences can resolve the long-debated issue of which Asian mtDNAs were founder sequences for the Native American mtDNA pool. Unfortunately, we now know that coding region data and their analysis are not without problems. To obtain and report reasonably correct sequences does not seem to be a trivial task, and to discriminate between Asian and Native American mtDNA ancestries may be more complex than previously believed. It is essential to take into account the effects of mutational hot spots in both the control and coding regions, so that the number of apparent Native American mtDNA founder sequences is not erroneously inflated. As we report here, a careful analysis of all available data indicates that there is very little evidence that more than five founder mtDNA sequences entered Beringia before the Last Glacial Maximum and left their traces in the current Native American mtDNA pool.

American Indian or Alaska Native↗
PubMed2003

Systemic sclerosis could mask the presentation of psoriasis in a patient with symptomatic and bilateral sacroiliitis.

Psoriasis is rarely associated with systemic sclerosis (SSc), and sacroiliitis associated to Connective Tissue Diseases is also rather rare. In this report we describe a case of a young woman with SSc who developed symptomatic and bilateral sacroiliitis. The clinical pattern of sacroiliac involvement of this patient resembles that of psoriatic sacroiliitis. HLA typing was compatible with both SSc and psoriasis. Psoriatic sacroiliitis could not be diagnosed, but, on the basis of these observations, the patient described could represent a case of PsA without psoriasis. and psoriatic cutaneous involvement masked by the presence of SSc.

Adult↗
PubMed2001

Do the four clades of the mtDNA haplogroup L2 evolve at different rates?

Forty-seven mtDNAs collected in the Dominican Republic and belonging to the African-specific haplogroup L2 were studied by high-resolution RFLP and control-region sequence analyses. Four sets of diagnostic markers that subdivide L2 into four clades (L2a-L2d) were identified, and a survey of published African data sets appears to indicate that these clades encompass all L2 mtDNAs and harbor very different geographic/ethnic distributions. One mtDNA from each of the four clades was completely sequenced by means of a new sequencing protocol that minimizes time and expense. The phylogeny of the L2 complete sequences showed that the two mtDNAs from L2b and L2d seem disproportionately derived, compared with those from L2a and L2c. This result is not consistent with a simple model of neutral evolution with a uniform molecular clock. The pattern of nonsynonymous versus synonymous substitutions hints at a role for selection in the evolution of human mtDNA. Regardless of whether selection is shaping the evolution of modern human mtDNAs, the population screening of L2 mtDNAs for the mutations identified by our complete sequence study should allow the identification of marker motifs of younger age with more restricted geographic distributions, thus providing new clues about African prehistory and the origin and relationships of African ethnic groups.

Base Sequence↗
PubMed2001

A signal, from human mtDNA, of postglacial recolonization in Europe.

Mitochondrial HVS-I sequences from 10,365 subjects belonging to 56 populations/geographical regions of western Eurasia and northern Africa were first surveyed for the presence of the T-->C transition at nucleotide position 16298, a mutation which has previously been shown to characterize haplogroup V mtDNAs. All mtDNAs with this mutation were then screened for a number of diagnostic RFLP sites, revealing two major subsets of mtDNAs. One is haplogroup V proper, and the other has been termed "pre*V," since it predates V phylogenetically. The rather uncommon pre*V tends to be scattered throughout Europe (and northwestern Africa), whereas V attains two peaks of frequency: one situated in southwestern Europe and one in the Saami of northern Scandinavia. Geographical distributions and ages support the scenario that pre*V originated in Europe before the Last Glacial Maximum (LGM), whereas the more recently derived haplogroup V arose in a southwestern European refugium soon after the LGM. The arrival of V in eastern/central Europe, however, occurred much later, possibly with (post-)Neolithic contacts. The distribution of haplogroup V mtDNAs in modern European populations would thus, at least in part, reflect the pattern of postglacial human recolonization from that refugium, affecting even the Saami. Overall, the present study shows that the dissection of mtDNA variation into small and well-defined evolutionary units is an essential step in the identification of spatial frequency patterns. Mass screening of a few markers identified using complete mtDNA sequences promises to be an efficient strategy for inferring features of human prehistory.

Africa, Northern↗
PubMed2001

Phylogeography of the human mitochondrial haplogroup L3e: a snapshot of African prehistory and Atlantic slave trade.

The mtDNA haplogroup L3e, which is identified by the restriction site +2349 MboI within the Afro-Eurasian superhaplogroup L3 (-3592 HpaI), is omnipresent in Africa but virtually absent in Eurasia (except for neighbouring areas with limited genetic exchange). L3e was hitherto poorly characterised in terms of HVS-I motifs, as the ancestral HVS-I type of L3e cannot be distinguished from the putative HVS-I ancestor of the entire L3 (differing from the CRS by a transition at np 16223). An MboI screening at np 2349 of a large number of Brazilian and Caribbean mtDNAs (encompassing numerous mtDNAs of African ancestry), now reveals that L3e is subdivided into four principal clades, each characterised by a single mutation in HVS-I, with additional support coming from HVS-II and partial RFLP analysis. The apparently oldest of these clades (transition at np 16327) occurs mainly in central Africa and was probably carried to southern Africa with the Bantu expansion(s). The most frequent clade (transition at np 16320) testifies to a pronounced expansion event in the mid-Holocene and seems to be prominent in many Bantu groups from all of Africa. In contrast, one clade (transition at np 16264) is essentially restricted to Atlantic western Africa (including Cabo Verde). We propose a tentative L3e phylogeny that is based on 197 HVS-I sequences. We conclude that haplogroup L3e originated in central or eastern Africa about 46,000 (+/-14,000) years ago, and was a hitchhiker of much later dispersal and local expansion events, with the rise of food production and iron smelting. Enforced migration of African slaves to the Americas translocated L3e mitochondria, the descendants of which in Brazil and the Caribbean still reflect their different regional African ancestries.

Africa↗
PubMed2000

Tracing European founder lineages in the Near Eastern mtDNA pool.

Founder analysis is a method for analysis of nonrecombining DNA sequence data, with the aim of identification and dating of migrations into new territory. The method picks out founder sequence types in potential source populations and dates lineage clusters deriving from them in the settlement zone of interest. Here, using mtDNA, we apply the approach to the colonization of Europe, to estimate the proportion of modern lineages whose ancestors arrived during each major phase of settlement. To estimate the Palaeolithic and Neolithic contributions to European mtDNA diversity more accurately than was previously achievable, we have now extended the Near Eastern, European, and northern-Caucasus databases to 1,234, 2, 804, and 208 samples, respectively. Both back-migration into the source population and recurrent mutation in the source and derived populations represent major obstacles to this approach. We have developed phylogenetic criteria to take account of both these factors, and we suggest a way to account for multiple dispersals of common sequence types. We conclude that (i) there has been substantial back-migration into the Near East, (ii) the majority of extant mtDNA lineages entered Europe in several waves during the Upper Palaeolithic, (iii) there was a founder effect or bottleneck associated with the Last Glacial Maximum, 20,000 years ago, from which derives the largest fraction of surviving lineages, and (iv) the immigrant Neolithic component is likely to comprise less than one-quarter of the mtDNA pool of modern Europeans.

DNA, Mitochondrial↗
PubMed1999

The A1555G mutation in the 12S rRNA gene of human mtDNA: recurrent origins and founder events in families affected by sensorineural deafness.

The mtDNA variation of 50 Spanish and 4 Cuban families affected by nonsyndromic sensorineural deafness due to the A1555G mutation in the 12S rRNA gene was studied by high-resolution RFLP analysis and sequencing of the control region. Phylogenetic analyses of haplotypes and detailed survey of population controls revealed that the A1555G mutation can be attributed to >/=30 independent mutational events among the 50 Spanish families and that it occurs on mtDNA haplogroups that are common in all European populations. This indicates that the relatively high detection rate of this mutation in Spain is not due to sampling biases or to a single major founder event. Moreover, the distribution of these mutational events on different haplogroups is compatible with a random occurrence of the A1555G mutation and tends to support the conclusion that mtDNA backgrounds do not play a significant role in the expression of the mutation. Overall, these findings appear to indicate that the rare detection of this mutation in other populations is most likely due to inadequacy in patient ascertainment and molecular screening. This probable lack of identification of the A1555G mutation in subjects affected by sensorineural hearing loss implies that their maternally related relatives are not benefiting from presymptomatic detection and information concerning their increased risk of ototoxicity due to aminoglycoside treatments.

DNA Mutational Analysis↗
PubMed1998

Development and validation of a clinical history form for the diagnosis of congestive heart failure.

Our aim was to develop and validate a new diagnostic tool for congestive heart failure (CHF) based only on clinical examination, medical history and current drug use. In the developmental phase, we enrolled 520 consecutive patients with heart disease of different etiology; the diagnosis of CHF was made by means of Smith's clinical and radiological criteria, and the Boston criteria, with a substantial interscale agreement (kappa = 0.89). The initial version of our Form included 37 items on clinical examination, medical history and drug use information. After an item reduction process, the final version of the Clinical History Form (CH Form) included 15 items, each with a score 1 to 4. The CH Form score showed a progressive, significant increase as NYHA Class increased. With a cut-off of 4 points, sensitivity was 88.6% and specificity 86.8% against Smith's criteria for diagnosis of CHF. Substantial interrater agreement was observed for all the 15 items (kappa > 0.6) on a subsample of 250 patients. In the validation phase, we studied an independent sample of 72 patients with heart disease. The CH Form was significantly correlated with left ventricular ejection fraction (r = 0.42; p < 0.0005) and peak oxygen consumption (r = 0.69; p < 0.0001). In the 64 (89%) patients who underwent non-emergent right-heart catheterization, the CH Form score was significantly correlated with pulmonary capillary wedge pressure (r = 0.84; p < 0.0001). The CH Form may represent a useful instrument for the diagnosis of CHF.

Aged↗
PubMed1998

Portal vein pulsatility ratio provides a measure of right heart function in chronic heart failure.

Portal vein flow was recorded by color Doppler sonography in 31 patients with chronic heart failure and 18 control subjects. Compared with patients showing a forward flow (Group A), those with reversed portal vein flow (Group B) had higher prevalence of tricuspid regurgitation (75% vs. 43%), hepatic congestion (100% vs. 30%) and ascites (50% vs. 18%), and showed higher right atrial pressure (25.3 +/- 3.01 mmHg vs. 11.8 +/- 5.75 mmHg, p < 0.01). In controls, portal vein pulsatility ratio was 0.66 +/- 0.08, in Group A it was 0.46 +/- 0.28 (p < 0.01), in Group B -0.60 +/- 0.19 (p < 0.01). Portal vein pulsatility ratio negatively correlated with right atrial pressure (r = -0.87; p < 0.01). In Group A, hepatic congestion, ascites and tricuspid regurgitation were associated with a higher portal vein pulsatility. This study indicates that portal vein pulsatility ratio reflects the level of impairment of the right heart.

Ascites↗
PubMed1998

mtDNA analysis reveals a major late Paleolithic population expansion from southwestern to northeastern Europe.

mtDNA sequence variation was studied in 419 individuals from nine Eurasian populations, by high-resolution RFLP analysis, and it was followed by sequencing of the control region of a subset of these mtDNAs and a detailed survey of previously published data from numerous other European populations. This analysis revealed that a major Paleolithic population expansion from the "Atlantic zone" (southwestern Europe) occurred 10,000-15,000 years ago, after the Last Glacial Maximum. As an mtDNA marker for this expansion we identified haplogroup V, an autochthonous European haplogroup, which most likely originated in the northern Iberian peninsula or southwestern France at about the time of the Younger Dryas. Its sister haplogroup, H, which is distributed throughout the entire range of Caucasoid populations and which originated in the Near East approximately 25,000-30,000 years ago, also took part in this expansion, thus rendering it by far the most frequent (40%-60%) haplogroup in western Europe. Subsequent migrations after the Younger Dryas eventually carried those "Atlantic" mtDNAs into central and northern Europe. This scenario, already implied by archaeological records, is given overwhelming support from both the distribution of the autochthonous European Y chromosome type 15, as detected by the probes 49a/f, and the synthetic maps of nuclear data.

DNA, Mitochondrial↗
PubMed1996

Myocardial ultrasonic tissue characterization in pediatric and adult patients with hypertrophic cardiomyopathy.

BACKGROUND: Hypertrophic cardiomyopathy (HCM) has different clinical and prognostic aspects in young than in adult patients. This study was undertaken to determine whether these reported differences are reflected by changes in ultrasonic backscatter parameters and whether oral treatment with verapamil modifies backscatter variables in children with HCM. METHODS AND RESULTS: Sixty-eight subjects underwent backscatter analysis to assess the ultrasonic myocardial reflectivity and the amplitude of the cardiac cycle-dependent variation of the backscatter power curve. Subjects were divided into four groups: 10 HCM and 23 normal subjects < 10 years old and 17 HCM and 18 normal adults. Myocardial reflectivity and amplitude of the cyclic variation were assessed in the septum and in the posterior wall of all subjects. The children with HCM were restudied after long-term oral administration of verapamil. Both children and adult patients, compared with the normal control groups, showed a significant reduction in the amplitude of the cyclic variation both in the septum and in the posterior wall. In contrast, myocardial reflectivity, although significantly increased in adult HCM patients, was unchanged in the young HCM group. Verapamil administration did not significantly alter the results in the children with HCM. CONCLUSIONS: These data demonstrate that in young HCM patients, the ultrasonic myocardial reflectivity is normal, in contrast to the significant increase observed in adult patients affected by the same disease. This observation is in accord with the different clinical manifestations reported in young HCM patients and indicates an age-dependent difference in the echogenic structure of the hypertrophied myocardium in HCM.

Adult↗
PubMed1995

Alterations in ultrasonic backscatter during exercise-induced myocardial ischemia in humans.

BACKGROUND: Experimentally induced myocardial ischemia in animals causes tissue modifications that alter characteristics of the ultrasonic beam backscattered from the myocardial muscle. Alterations of backscatter parameters have been evidenced in human subjects with acute or remote myocardial infarction and during ischemia induced by angioplasty balloon occlusion or pharmacological stimuli. The effects of transient effort ischemia in humans have not been reported. The purpose of this study is to assess ultrasonic backscatter parameter changes induced by transient effort myocardial ischemia in human subjects. METHODS AND RESULTS: Nineteen patients with single left anterior descending coronary stenosis and 15 healthy subjects underwent ultrasonic backscatter analysis (parasternal long-axis view) at rest, immediately after a supine stress test, and 30 minutes later. Two windows were selected in each ultrasonic study: one encompassing the septum; the other, the posterior wall. Integrated backscatter was computed throughout the cardiac cycle, yielding a power curve relative to the midmyocardial region of the myocardial wall (excluding pericardial and endocardial borders). Five parameters were computed from the backscatter power curve: the maximum-minimum difference, amplitude and phase of the first harmonic Fourier fitting, phase-weighted amplitude, and time-averaged integrated backscatter difference from rest (an index of overall myocardial reflectivity). This protocol allowed comparison of the backscatter data from a region at risk of ischemia (the septum) with that from a region normally perfused (posterior wall) and a comparison with the same regions of the control group during the three ultrasonic studies. All backscatter indexes in the septum were altered significantly by exercise compared with rest values, whereas no changes were found in the normally perfused posterior wall or in the septum of the control group. All modified parameters returned to baseline values at the time of the recovery study. CONCLUSIONS: These data indicate that transient, exercise-induced ischemia is associated with reduction of the cardiac cycle-dependent variation of the integrated backscatter power curve, a temporal shift in the nadir of the power curve with respect to the R wave (phase increase), and a small but detectable increase of myocardial reflectivity. These changes may be detected noninvasively in humans with ultrasonic backscatter analysis.

Adult↗
PubMed1995

Comparison of the safety and efficacy of delapril with enalapril in patients with congestive heart failure.

To evaluate the safety and efficacy of delapril versus enalapril in patients with congestive heart failure (CHF), New York Heart Association (NYHA) class II and III, 198 patients were enrolled in a study in 13 centers involving a double-blind parallel group design. After completing a 2-week run-in period on placebo, patients were randomized to receive delapril 7.5 mg twice daily or enalapril 2.5 mg twice daily for 2 weeks. The dose was then doubled for the remaining 6 weeks. In this phase, 1 patient in each group experienced orthostatic hypotension; the dose was then reduced to the initial dose for study completion. A total of 195 patients received active treatment (96 delapril, 99 enalapril). After 8 weeks' treatment, bicycle ergometry demonstrated a significant increase in exercise duration (p < 0.01) and workload (p < 0.01). Echo Doppler investigations showed a significant reduction (p < 0.01) in left ventricular end-systolic volume associated with a significant increase (p < 0.01) in ejection fraction and cardiac output. No clinically significant changes in blood pressure, heart rate, electrocardiogram, or biochemical and hematologic tests were found. There were no significant differences between treatment groups. Three patients in each group experienced adverse reactions requiring withdrawal of 1 patient in each group. Delapril 15 mg twice daily, like enalapril 5 mg twice daily, was effective in improving signs and symptoms of CHF and was well tolerated.

Administration, Oral↗
PubMed1995

Congestive heart failure in elderly patients: controlled study of delapril versus captopril.

In this controlled trial, 30 elderly patients with congestive heart failure, New York Heart Association (NYHA) classes II and III, were randomly assigned to treatment with captopril 25 mg three times daily or delapril 15 mg twice daily. At the end of an 8-week treatment period, clinical symptoms of heart failure were significantly relieved by both drugs, with a consistent and statistically significant improvement in patients' quality of life evaluated using a symptoms/activity scale (p < 0.001). None of the patients was judged NYHA class III at the end of the trial and 40% were assigned to class I (p < 0.01). There was a relevant, but not statistically significant, increase in exercise duration in both treatment groups (10% captopril group, 14% delapril group), but the number of patients discontinuing the exercise test for dyspnea was 50% less in the delapril group. Neither drug had evident effects on echocardiographic left ventricular parameters. Two patients treated with captopril and 3 with delapril complained of mild-to-moderate adverse reactions. The safety of both drugs was confirmed by laboratory tests.

Aged↗
PubMed1995

Age-response effectiveness of gallopamil for the treatment of myocardial exertional ischemia. A medium-term randomized cross-over double-blind placebo-controlled trial.

We evaluated the efficacy and safety of gallopamil 150 mg daily in middle-aged and elderly patients with stable exertional ischemia, using a medium-term randomized double-blind cross-over placebo-controlled trial. Twenty middle-aged patients (52.8 +/- 6 years; range 38-61 years) and 14 elderly patients (67.4 +/- 2.8 years; range 65-73 years) with stable exertional ischemia underwent a bicycle exercise test. After a run-in period, both groups received treatment with either placebo or gallopamil 50 mg tid for 28 days. At the end of this time, each patient crossed over to the alternate regimen. Gallopamil significantly reduced heart rate, blood pressure and rate pressure product (from 15.37 +/- 2.7 to 13.65 +/- 4.16 U x 10(-3); p < 0.01) in elderly patients at submaximal exercise, but had no effect in middle-aged patients (from 14.52 +/- 4.45 to 13.49 +/- 3.77 U x 10(-3); p = NS). At peak exercise, none of the hemodynamic parameters was modified with gallopamil in either group. At peak exercise, both middle-aged and elderly patients achieved rate-pressure products similar to those reached during placebo at higher work loads. Exercise duration and maximal work load significantly increased in both groups. Electrocardiographic signs of ischemia were favorably influenced by gallopamil in both groups (from 1.39 +/- 0.5 mm to 0.76 +/- 0.73 mm; p < 0.001 in the middle-aged patients and from 1.5 +/- 0.34 mm to 1 +/- 0.76 mm; p < 0.01 in the elderly patients).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗