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PubMed2005

Spatiotemporal patterns of reinfestation by Triatoma guasayana (Hemiptera: Reduviidae) in a rural community of northwestern Argentina.

Triatoma guasayana (Wygodzinsky & Abalos) is a secondary vector of Trypanosoma cruzi (Chagas), the etiologic agent of Chagas disease, in the Chaco region of Argentina, Bolivia, and Paraguay. The spatial distribution of T. guasayana in a rural community in northwestern Argentina is described and analyzed using very high spatial resolution satellite imagery, geographic information systems, and spatial statistics. Since a 1992 residual spraying with insecticides of all houses, site-specific domestic and peridomestic reinfestations by triatomine bugs were monitored using various methods semiannually from 1993 to 2002. The reinfestation by T. guasayana started with finding of only adult bugs in a few sites. Bug abundance was significantly clustered and predominantly peridomestic in the southern and northern extremes of the community. The identified source of reinfestation in the northern cluster was a colonized wood pile, whereas no potential peridomestic source was found for the southern cluster. The spatial distribution of T. guasayana was positively associated with the abundance and spatial distribution of goats. Active dispersal from the hypothesized source and the surrounding sylvatic environment, and passive transport of bugs in wood piles seems to be the most likely mechanisms underlying the observed spatial pattern of T. guasayana. The absence of domestic colonization indicates that, to date, there is no trend toward increased local domiciliation of T. guasayana. The clustering zones can be considered "hot spots" where bug invasion from other sources is expected to be higher and where eventually, introduction of sylvatic T. cruzi to suitable hosts may occur.

Animals↗
PubMed1996

Bladder cancer mortality associated with arsenic in drinking water in Argentina.

Inorganic arsenic (In-As) is known to be a human carcinogen, causing lung cancer by inhalation and skin cancer by ingestion. Ecologic studies in Taiwan have found a dose-response relation between ingestion of In-As from drinking water and bladder cancer, but questions have been raised concerning the validity and generalizability of the findings. Several areas of Argentina have had high exposures to arsenic from naturally contaminated drinking water, particularly the eastern region of the province of Córdoba. In this study, we investigated bladder cancer mortality for the years 1986-1991 in Córdoba's 26 counties, using rates for all of Argentina as the standard for comparison. Bladder cancer standardized mortality ratios (SMRs) were consistently higher in counties with documented arsenic exposure. We grouped counties into low-, medium-, and high-exposure categories; the corresponding SMRs [with 95% confidence intervals (CI)] were 0.80 (95% CI = 0.66-0.96), 1.42 (95% CI = 1.14-1.74), and 2.14 (95% CI = 1.78-2.53) for men, and 1.21 (95% CI = 0.85-1.64), 1.58 (95% CI = 1.01-2.35), and 1.82 (95% CI = 1.19-2.64) for women. The clear trends found in a population with different genetic composition and a high-protein diet support the findings in Taiwan.

Adolescent↗
PubMed2003

Teaching Humanities at the National University of la Plata, Argentina.

In this article the author begins by giving a brief history of medical education in Argentina, then provides some background information on the National University of La Plata. He describes two major initiatives at La Plata: a new and pioneering admission policy (implemented in 1993) and a change in the number of hours and years in the curriculum. He then looks back to the introduction in 1976 of La Plata's medical humanities program. Over its 20 year existence, the program has undergone a number of changes in response both to students' interests and financial concerns. The revised humanities curriculum now consists of four elective courses: medicine and literature, anthropology, history of medicine, and "medical kalology" (which focuses on music and dance). Unfortunately, the program, while it has been well received by both students and faculty and has inspired programs at other Argentinean schools, is threatened by Argentina's economic crisis.

Argentina↗
PubMed2002

Epidemiologic patterns of diarrheal disease in Argentina: estimation of rotavirus disease burden.

BACKGROUND: Information on the burden of diarrheal diseases and rotavirus diarrheal diseases would help define strategies for management and prevention and clarify the potential benefits of candidate vaccines. This report of our study of the epidemiology of rotavirus diseases in Argentina analyzes the burden of rotavirus diarrhea, based on those studies and national statistics of diarrhea-associated medical visits, hospital discharges and deaths. METHODS: Information of diarrhea-associated medical visits, hospital discharges and deaths were provided by the Argentine Health Ministry. Estimation of rotavirus disease burden was performed using the percentage of rotavirus identification from previous reports. RESULTS: The incidence of diarrhea-associated medical visits (1999) was 14 times greater for ages 0 to 4 years than for ages of > or =5 years. Diarrhea-associated hospital discharges (0 to 4 years of age) decreased between 1981 and 1995 from 1.3 per 100 to 0.9 per 100 person-years) and diarrheal deaths (<2 years of age) decreased by a factor of 4 between 1985 and 1999 (64.7 per 100 000 to 16.1 per 100 000 person-years). Frequency of diarrheal deaths, hospital discharges and medical visits were highest in some of the northern Argentine provinces (26.2, 14.7 and 5.9 times greater, respectively, than in the lower risk areas of the country). We estimated that 1 in 2 children born in 1995 visited a public hospital, 1 in 12 required hospitalization, 1 in 1599 died of diarrheal diseases before their fifth year of life; 1 in 6, 1 in 35 and 1 in 4169 of those, respectively, died as a result of rotavirus diarrhea before their third year of life. CONCLUSIONS: The number of preventable diarrhea-associated and rotavirus-associated hospitalizations and deaths in Argentina is significant. The lack of rotavirus diagnostic capability in Argentine hospitals has resulted in underestimation of the disease burden of this virus. A rotavirus vaccine would have the potential to avoid thousands of hospitalizations and dozens of deaths, especially in the poor high risk Argentine provinces.

Age Factors↗
PubMed1998

Alcohol, methylxanthine-containing beverages, and colorectal cancer in Córdoba, Argentina.

The relationship between social class indicators, body mass index (BMI), selected life-style habits (alcohol, coffee, maté and tea drinking) and colorectal cancer was investigated in a case-control study conducted between 1993 and 1997 in Córdoba, Argentina, a relatively high mortality area of colorectal cancer. Cases were 190 patients below age 80 years with incident, histologically confirmed colorectal adenocarcinomas, and controls were 393 patients admitted to hospital for a wide spectrum of acute, non-neoplastic disorders. Higher social class, based on occupation of the head of the household, was significantly associated with colorectal cancer risk: the odds ratios (OR) and 95% confidence intervals (95% CI) were 1.9 (1.2-2.9) for intermediate and 2.0 (1.2-3.4) for the highest as compared to the lowest social class individuals. When compared with subjects whose BMI was < 25 kg/m2, the OR was 1.1 (0.7-1.6) for those with BMI 25 to 29 kg/m2, and 1.3 (0.7-2.3) for those > or = 30. In comparison with alcohol abstainers, the OR was 2.8 (1.6-5.1) for drinkers, and there was a significant trend in risk with dose. The association was observed with wine (the most common alcoholic beverage in Argentina), as well as for beer and spirits. The consumption of coffee, maté and tea was not significantly related to colorectal cancer, but the ORs were below unity (0.9 (0.7-1.3) for coffee, 0.9 (0.6-1.2) for maté and 0.8 (0.6-1.2) for tea drinkers). The relationship between social class, alcohol drinking and colorectal cancer were consistent across strata of sex and age. This study confirms that colorectal cancer has positive social class correlates. The association with alcohol drinking is apparently stronger than previously reported, and may be due to the role of chance and/or peculiar correlates of alcohol drinking in this Argentinean population.

Adult↗
PubMed2002

Two HIV-1 epidemics in Argentina: different genetic subtypes associated with different risk groups.

This study determined the risk behaviors and viral subtypes of HIV-1 found in 134 heterosexual HIV-seroprevalent maternity patients, 41 of their sexual partners (men who have sex with women [MSW]), and 95 homosexual men (men who have sex with men [MSM]) from Buenos Aires, Argentina. Peripheral blood mononuclear cells (PBMCs) were purified from blood and used for DNA extraction, amplification, and genotyping by the envelope heteroduplex mobility assay (env HMA). Most of the women had been infected by having sex with an already infected partner (84%), whereas most of the male partners had been infected via drug use (76%). Both the patients and their sexual partners were poorly educated, only 30% having completed secondary school. The MSM study subjects, however, were significantly better educated and had a lower prevalence of injecting drug use.Env HMA subtype F was found in 77% (103 of 134) of the maternity patients, with similar rates in their partners (73%). Most of the remaining samples were env subtype B. All but one of the couples was concordant in subtype. In the MSM risk group, however, only 10% were env HMA subtype F. Ninety percent of the MSM samples were subtype B. There are at least two independent epidemics of HIV-1 infection in Buenos Aires, Argentina. One, in heterosexual men and women, is dominated by env subtype F whereas the other, in homosexual men, is dominated by env subtype B, as determined by env HMA.

Argentina↗
PubMed2003

A cluster of human T-cell lymphotropic virus type I-associated myelopathy/tropical spastic paraparesis in Jujuy, Argentina.

Compared with other regions in Argentina, greater human T-cell lymphotropic virus type I (HTLV-I) seroprevalence has been reported in Jujuy Province, where it reaches 2.32% in the general population, so that a search for HTLV-I-associated myelopathy/tropical spastic paraparesis (HAM/TSP) cases deserved to be carried out. Accordingly, a clinically diagnosed and serologically confirmed cluster of cases in 1 man and 10 women, including 2 sisters, is described here. Most patients (9/11) were born in Cochinoca Department, located in an Andes highland area called Puna Jujeña, situated at more that 3400 m above sea level. No history of risk factors was disclosed, except for a single transfusion in 1 patient. In contrast to the Andean region of Bolivia, where high HTLV-I seroprevalence is in part attributable to Japanese immigrants, the Jujuy population mainly consists of aborigines, mestizos, and European descendants. Therefore, the long-term presence of virus in Jujuy natives may be taken for granted. Considering the HAM/TSP cluster described here plus previously reported isolated cases in neighboring Salta Province, we speculate that the Puna Jujeña region and regions in that vicinity would be a microepidemic focus of disease. To determine the role of possible pathogenic cofactors such as geographic, ethnic, genetic, and cultural features, further pertinent surveys are required in subtropical northwestern Argentina.

Argentina↗
PubMed2004

Intersubtype BF recombinants of HIV-1 in a population of injecting drug users in Argentina.

The presence of recombinant intersubtypes of HIV-1 in Argentina has been reported since the mid-1990s. In this study, sequences of a region of the gag, pol, and vpu genes of HIV-1 were analyzed in samples of 21 injection drug users (IDUs) residing in the suburbs of the city of Buenos Aires. Genomic characterization and identification of recombination sites were made comparing the 3 regions with reference isolation sequences of subtypes B, F, C, A, and B/F recombinants: CRF12_BF and non-CRF12_BF sequences. Subtype assignment of the analyzed segments was phylogenetically confirmed. All the samples turned out to be BF recombinants in at least 1 of the 3 studied genes. Twelve samples (57%) had the same pattern as the Argentinean CRF12_BF, whereas in the rest, the pattern differed in at least 1 of the 3 genes. The relation of these fragments to the CRF12_BF was phylogenetically verified. These results indicate the predominance of BF recombinants and the presence of a high percentage of sequences closely related to the CRF12_BF in the IDU population in Argentina and suggest a possible association between viral variants and the transmission route.

Argentina↗
PubMed2006

The programs and context of medical education in Argentina.

There are 29 medical schools in Argentina (this number has increased rapidly in the last decade) offering a 6-year curriculum that usually consists of 3 years of basic science, 2 years of clinical sciences, and one internship year. Annually, 5,000 physicians graduate from these programs. Admission requirements vary depending on each university's policy. Some do not have entry requirements; others require a course, usually on the basics of mathematics, biology, chemistry or physics, and some introduction to social and humanistic studies. Each year, there are approximately 12,000 first-year medical students attending the 29 schools, which suffer a high dropout rate during the first years because of vocational problems or inability to adapt to university life. Some schools have massive classes (over 2,000 students), which makes it difficult for the schools to perfect their teaching. The number of full-time faculty members is low, and some of them have appointments at more than one medical school. Residency programs offer an insufficient number of places, and fewer than 50% of the graduates can obtain a residency position because of strict admission requirements. Coordination between the Ministry of Health, representing the health care system, and the Ministry of Education, representing the medical education system, needs to be improved. Despite the problems of medical education in Argentina, the movement to improve the education of health care workers is growing. The author offers two recommendations to help accomplish this goal.

Accreditation↗
PubMed2004

Impact of haemophilus influenzae type b conjugate vaccine in South Africa and Argentina.

INTRODUCTION: Haemophilus influenzae type b (Hib) persists as a major cause of pediatric meningitis and pneumonia in developing countries in which Hib conjugate vaccines are not used. Demonstration of decreases in severe Hib disease after countries introduce Hib conjugate vaccine will help justify the resources necessary to purchase and provide the vaccine. Because surveillance for culture-confirmed Hib meningitis is not available in many countries, alternative means to measure the impact of Hib conjugate vaccine would be useful. METHODS: Laboratory records from the years before and after introduction of the Hib conjugate vaccine were reviewed at 4 hospitals, 2 in Argentina and 2 in South Africa. Potential indicators of bacterial meningitis including cerebrospinal fluid (CSF) culture, white blood cell count, appearance, protein and glucose were recorded. RESULTS: After introduction of Hib conjugate vaccine, culture-confirmed Hib meningitis declined significantly at 3 of 4 hospitals (2 in Argentina and 1 in South Africa). In the same 3 hospitals, there was a significant decline after vaccine introduction in some of the following CSF indicators of bacterial meningitis: proportion of CSF specimens with white blood cell count > or = 100 x 10(6)/L, 500 x 10(6)/L and 1,000 x 10(6)/L; glucose <40 mg/dL; protein >100 mg/dL; and turbid appearance. CONCLUSIONS: Culture-confirmed Hib meningitis declined at 3 of the 4 hospitals after Hib vaccine introduction. Surrogate indicators of bacterial meningitis also declined and might be useful measures of Hib conjugate vaccine impact at hospitals where capacity to culture Hib is not available.

Age Distribution↗
PubMed2006

Arsenic methylation and bladder cancer risk in case-control studies in Argentina and the United States.

OBJECTIVE: We sought to assess whether the metabolism of arsenic impacts a person's susceptibility to bladder cancer. METHODS: Urinary methylation products were measured in subjects from Argentina (114 cases and 114 controls) and the United States (23 cases and 49 controls). RESULTS: In Argentina, the adjusted odds ratio (OR) for subjects with a high proportion of ingested arsenic excreted as monomethylarsonate (%MMA) was 2.17 (95% confidence interval [CI] = 1.02-4.63) in smokers and 0.48 (95% CI = 0.17-1.33) in nonsmokers. In the United States, the adjusted ORs for high %MMA in subjects with arsenic intakes less than and greater than 100 microg/d were 1.20 (95% CI = 0.27-5.38) and 2.70 (95% CI = 0.39-18.6). CONCLUSIONS: Overall, these results are consistent with data from Taiwan suggesting that some individuals who excrete a higher proportion of ingested arsenic as MMA are more susceptible to arsenic-related cancer.

Aged↗
PubMed2006

Update on primary HIV-1 resistance in Argentina: emergence of mutations conferring high-level resistance to nonnucleoside reverse transcriptase inhibitors in drug-naive patients.

Here we present a survey including 52 drug-naive recently HIV-1-infected subjects from Buenos Aires City and province (79%) and 3 other regions in Argentina (21%). Recent infections were established from previous negative serology (32/52), indeterminate Western blot (12/52), or acute retroviral syndrome after high-risk HIV exposure (8/52) within 9 months before genotyping (median time, 4.2 months). Genotyping was performed from plasma by sequencing both protease and reverse transcriptase. Phylogenetic analysis combined with bootscanning resulted in 21 subtype B sequences and 31 B/F recombinants (RecBF). On protease, minor resistance-related mutations were found in both subtype B and RecBF with low frequencies. The substitution L89M, recently suggested as a resistance-related mutation in some subtype F viruses, was observed in 1 RecBF. On reverse transcriptase, major resistance-related mutations were found in 4 of 52 (7.7%) patients from different health centers: M41L (subtype B) and K103N+/-P225H (1 RecBF and 2 subtype B). The greater than 5% resistance threshold found indicates a need for sentinel resistance surveillances calling for an update in the current resistance testing guidelines in Argentina.

Argentina↗
PubMed2002

Diversity of mosaic structures and common ancestry of human immunodeficiency virus type 1 BF intersubtype recombinant viruses from Argentina revealed by analysis of near full-length genome sequences.

The findings that BF intersubtype recombinant human immunodeficiency type 1 viruses (HIV-1) with coincident breakpoints in pol are circulating widely in Argentina and that non-recombinant F subtype viruses have failed to be detected in this country were reported recently. To analyse the mosaic structures of these viruses and to determine their phylogenetic relationship, near full-length proviral genomes of eight of these recombinant viruses were amplified by PCR and sequenced. Intersubtype breakpoints were analysed by bootscanning and examining the signature nucleotides. Phylogenetic relationships were determined with neighbour-joining trees. Five viruses, each with predominantly subtype F genomes, exhibited mosaic structures that were highly similar. Two intersubtype breakpoints were shared by all viruses and seven by the majority. Of the consensus breakpoints, all nine were present in two viruses, which exhibited identical recombinant structures, and four to eight breakpoints were present in the remaining viruses. Phylogenetic analysis of partial sequences supported both a common ancestry, at least in part of their genomes, for all recombinant viruses and the phylogenetic relationship of F subtype segments with F subtype viruses from Brazil. A common ancestry of the recombinants was supported also by the presence of shared signature amino acids and nucleotides, either unreported or highly unusual in F and B subtype viruses. These results indicate that HIV-1 BF recombinant viruses with diverse mosaic structures, including a circulating recombinant form (which are widespread in Argentina) derive from a common recombinant ancestor and that F subtype segments of these recombinants are related phylogenetically to the F subtype viruses from Brazil.

Argentina↗
PubMed2005

Prevalence, clinical spectrum and atypical symptoms of gastro-oesophageal reflux in Argentina: a nationwide population-based study.

BACKGROUND: Population-based data on gastro-oesophageal reflux in Latin America are lacking. AIM: To assess gastro-oesophageal reflux symptom prevalence, clinical spectrum and association with the atypical symptoms in our country. METHODS: Gastro-oesophageal reflux self-report questionnaires validated at Mayo Clinic, USA, were submitted to a sample of 1000 residents (aged 18-80 years) from 17 representative geographical areas of Argentina. The samples were selected and stratified according to age, gender, geographical areas and size of town of residence provided by the Argentine Bureau of Statistics and Census. RESULTS: The overall prevalence of any typical gastro-oesophageal reflux symptom experienced in the previous year was 61.2% (95% CI, 57.9-64.6), the prevalence of frequent gastro-oesophageal reflux symptoms was 23.0% (95% CI, 20.1-25.9) and the prevalence of gastro-oesophageal reflux disease was 11.9% (95% CI, 9.6-14.1). Frequent gastro-oesophageal reflux symptoms were associated with dysphagia (OR 2.12, 95% CI, 1.27-3.54, P < 0.01), globus (OR 2.22, 95% CI, 1.35-3.66, P < 0.01) and non-cardiac chest pain (OR 1.55, 95% CI, 1.04-2.31, P < 0.05). CONCLUSIONS: In Argentina, typical symptoms of gastro-oesophageal reflux are highly prevalent at the national level, and frequent gastro-oesophageal reflux symptoms are significantly associated with dysphagia, globus and non-cardiac chest pain.

Adolescent↗
PubMed2005

Yeasts associated to Malbec grape berries from Mendoza, Argentina.

AIMS: The aims of this work were to evaluate different pre-isolation treatments applied to complete yeast extraction from grapes and to identify the yeast microflora associated to Malbec grapes from two vineyards located in Mendoza, Argentina. METHODS AND RESULTS: The pre-isolation treatments evaluated were shaking, jet streaming with pressurized water and grape blending. The overall results clearly indicated that when a more vigorous and disruptive pre-isolation treatment was applied; larger numbers of yeast species were recovered. The yeast population on healthy and ripe Malbec grapes was in the order of 10(5)-10(6) CFU g(-1). Eight different yeast species were isolated from berries, including Kloeckera apiculata, Metschnikowia pulcherrima, Pichia membranifaciens, Saccharomycodes ludwigii, Candida species (Candida stellata and Candida raghi), Issatchenkia orientalis and Rhodotorula spp. CONCLUSIONS: Grape blending gave the highest yeast counts. Rainfall near grape harvest time quantitatively and qualitatively modifies the yeast microflora. The yeast species identified on ripe grapes from the Mendoza region, partially match those previously documented in different parts of the world related. S. ludwigii has not been previously reported in grapes. SIGNIFICANCE AND IMPACT OF THE STUDY: The report is on yeast microbiota in grapes from Mendoza, Argentina. Saccharomycodes ludwigii was found in high percentage (17%), this species has not been described before on grapes surface. The importance of pre-isolation steps to the recovery of high number of yeasts was shown. Influence of climatic conditions near harvest time on microflora was confirmed.

Argentina↗
PubMed2001

Prevalence of celiac disease in Argentina: screening of an adult population in the La Plata area.

OBJECTIVES: Up to now, the epidemiological characteristic of celiac disease among adults in South America remains unknown. The present prospective screening was designed to determine the prevalence of celiac disease in adults from the general population in an urban area of Argentina. METHODS: Between January. 1998, and May, 2000, all couples attending a centralized laboratory for an obligatory prenuptial examination in the La Plata area were offered participation in a screening program for celiac disease. The study included 2000 subjects (996 women; median age 29 yr, range 16-79 yr). All individuals completed a clinical questionnaire at the time that serum samples were obtained. A three-step screening protocol was used, as follows: 1) all samples were tested for antigliadin antibodies (AGAs) (type IgA and IgG); 2) samples that were IgA AGA positive were tested for antiendomysial antibody (EmA type IgA); samples that were positive for AGA-G but negative for IgA AGAs were tested for total IgA serum levels and EmA type IgG; and 3) subjects who were EmA-positive were referred for intestinal biopsy. RESULTS: At the end of the screening we detected 10 subjects who were EmA-A positive and two others who were IgA-deficient (both were EmA-G positive). Up to now, 11 of the 12 subjects (including nine EmA-positive and two IgA-deficient subjects) had endoscopic intestinal biopsies showing the characteristic celiac histology. The remaining EmA-positive individual was considered to be affected by celiac disease. The overall prevalence assessed was 1:167 (6.0 x 1000 subjects; 95% CI = 3.1-10.5). Eight of the 12 (67%) subjects were female (1:124; 8.0 x 1000; 95% CI = 3.5-15.8) and four (33%) were male (1:251; 4.0 x 1000; 95% Cl = 1.1-10.2). Although eight new patients were considered to be asymptomatic, three presented with a subclinical course and one was classically symptomatic. Only one patient had been previously diagnosed with celiac disease. CONCLUSIONS: Our screening protocol showed a very high prevalence of celiac disease for an urban area of Argentina that is ethnically similar to 90% of the general population of the country. The prevalence among women was double that for men, and the heterogeneous clinical picture of new patients showed predominance of asymptomatic cases.

Adolescent↗
PubMedDate not supplied

Sunbed use in Buenos Aires, Argentina.

The objectives were to survey tanning salons in a defined geographic area of Buenos Aires city and to assess the information offered to consumers regarding chronic exposure to ultraviolet radiation, types of radiation used, and safety measures employed. A prospective study using a standardized interview with limited multiple choice responses for data collection was conducted. Results of the interview survey were that 35% of the establishments (tanning salons) said they used UVA exclusively, 6% UVB, and 25% both; 35% did not know the type of radiation to which their clients were exposed. Sunbeds were promoted as healthy in 56% of the tanning salons, whereas potential risks were mentioned in only 15%. One to 3 sessions on the same day were allowed by 84%, while 40% allowed customers to choose the number of weekly sessions. The use of goggles was optional in 65% of the establishments and 21% did not even provide goggles. Use of sunscreens was not compulsory, and none of the salons had associated physicians. Previous history of skin cancer, sunburn or potential photosensitive drug intake were never recorded, and the age of access was not restricted in 71% of the establishments. In Argentina there are no guidelines to regulate the operation of tanning salon establishments or the equipment they use, and there are no specific measures taken to prevent skin and ocular pathologies. Ways to reduce the risks of ocular and skin pathologies from artificial tanning in Argentina are urgently needed.

Argentina↗
PubMed2000

Cytogenetic proof that the brine shrimp Artemia franciscana (Crustacea, Branchiopoda) is found in Argentina.

Artemia brine shrimps are commercially important and they have been extensively studied. This branchiopod crustacean is extensively used in aquaculture and other commercial and applied practices. The genus also awakes an increasing interest worldwide as an experimental model in other basic areas of research such as evolution and cytogenetics. In the present work adult male meiosis and nauplii mitotic cells in two Artemia populations from Argentina (Mar Chiquita and Las Tunas, Córdoba Province) are analyzed and compared to the reference strains A. franciscana (Great Salt Lake, Utah, USA) and A. persimilis (Salinas Grandes de Hidalgo, La Pampa Province, Argentina). The Mar Chiquita population shows the diploid and haploid numbers characteristic of A. franciscana, and a regular male meiosis. In the Las Tunas population diverse diploid and haploid numbers are encountered, and an irregular meiosis is observed in some individuals. Fluorescent DAPI and CMA banding shows bright chromocenters of intermediate size and number in both populations. Cytogenetic and phenotypic data show that the population of Mar Chiquita could be assigned to A. franciscana; the variation found in chromocenter size and number reflects an heterochromatin polytypism already observed in this species. The cytogenetic and morphological traits in Las Tunas population suggest an occasional hybridization between A. franciscana and A. persimilis.

Animals↗