Cytogenetic

Climate Warming Studies in Alpine Habitats of Indian Himalaya, using Lichen based Passive Temperature-enhancing System

by Himanshu Rai

Co-authored with Pramod Nag, D.K. Upreti, Rajan K Gupta

Increase in the average annual temperature of the planet is posing an intimate threat to global biodiversity. Though... more Increase in the average annual temperature of the planet is posing an intimate threat to global biodiversity. Though high altitude alpine habitats, due to their physico-chemical constrains are some of the extremely fragile habitats, they harbor unique diversity of life forms. Indian Himalayan habitats are abode of a diverse lichen community, and have evolved into various growth forms. Lichens inhabit nearly all the terrestrial and boreal domains of the region. Lichens are more sensitive to changes in environmental conditions than all other plant forms. Passive temperature enhancing systems (PTES) such as open top chambers (OTC) are most appropriate devices to experimentally simulating the global temperature alleviation as they use trapped solar energy to enhance the ambient temperature of experimental area. PTES experimental setups utilizing lichens can be a very efficient method for studying effect of temperature alleviation on plants.

Biological dosimetry based on the detection of Micronuclei in exposed patients to cobalt-therapy in Paraguay

by Virginia Fernandez Peralta

Fernandez V, Gomez F, Guggiari G, Resquin T, Cabañas F, Alonso J. Biological dosimetry based on the detection of Micronuclei in exposed patients to cobalt-therapy in Paraguay. Revista Oncologia Paraguaya - Instituto Nacional del Cancer "Prof. Dr. Manuel Riveros". 2009;1:23-31.

Las radiaciones ionizantes son genotoxicas y pueden ser cancerigenas si las dosis de radiacion son superiores a los... more Las radiaciones ionizantes son genotoxicas y pueden ser cancerigenas si las dosis de radiacion son superiores a los valores dictados por normas nacionales e intemacionales. Los efectos genot6xicos son estudiados mediante los bioensayos de Micronucleos (MN) en celulas de la mucosa bucal de pacientes con cancer del Instituto Nacional de Cancer de Aregua, los cuales, dentro del esquema de tratamiento son expuestos a radiaciones ionizantes.
El objetivo del presente trabajo es el de evaluar el nivel de genotoxicidad en diferentes modalidades de exposici6n al tratamiento radioterapeutico y relacionarlo con las dosis de radiacion.
Los resultados de los analisis presentaron una amplia variabilidad en el conteo de Micronucleos, debido a factores Fisicos y Biologicos, como las diversas dosis de radiacion para el tratamiento de diversos tumores en diferentes organos.
Como conclusion se observa que cuanto mas lejana es la zona deirradiacion a la toma de Ia muestra (la mucosa bucal) hay una disminucion en Ia aparici6n de MN, este hecho puede llevar a Ia estimaci6n de las dosis de radiaci6n absorbida por el paciente y la determinacion de niveles de formacion de MN, como un indicador biologico de buena practica.
Tambien se ha identificado una diferencia sustancial entre Ia frecuencia de micronucleos y el alto porcentaje de celulas apoptoticas a partir del octavo dia de tratamiento, en ciertos pacientes.

Acción de las Plantas Paraguayas sobre el Ciclo Replicativo Celular en Meristemas de Allium cepa

by Virginia Fernandez Peralta

FERNÁNDEZ, V.; DESVARS, N.; FRANCO DE DIANA, D.; BENITEZ, B. ”Acción de las Plantas Paraguayas sobre el Ciclo Replicativo Celular en Meristemas de Allium cepa”. Revista Científica de la Universidad Nacional de Asunción, Vol. 1. 2000.

Detección de Efectos Citogenéticos en Células Animales tratadas con Plantas Medicinales Paraguayas

by Virginia Fernandez Peralta

FERNÁNDEZ, V.; FRANCO DE DIANA, D.; TORRES, E.; BENITEZ, B. “Detección de Efectos Citogenéticos en Células Animales tratadas con Plantas Medicinales Paraguayas”. Revista Científica de la Universidad Nacional de Asunción. Vol. 1. 2000.

Chromosome studies on Plants from Paraguay

by Virginia Fernandez Peralta

Daviña J, Honfi A, Franco de Diana D, Fernandez V, Lirussi I, Rovira A, et al. Chromosome studies on Plants from Paraguay. FYTON - International Journal of Experimental Botany. 2001;:215-224.

The chromosome number of 21 species belonging to 9 Angiosperm families from Paraguay are given. We report for the... more The chromosome number of 21 species belonging to 9 Angiosperm families from Paraguay are given. We report for the first time the chromosome number for the following species: Enhydra anagallis (n=12), Cuphea campylocentra (2n=16), Cuphea micrantha (2n=16) and Cuphea pterosperma (2n=48). We added a new chromosome number for Cuphea glutinosa (2n=34).

Cytogenetic analysis in the terrestrial orchid Sacoila argentina (Griseb.) Garay from Paraguay

by Virginia Fernandez Peralta

Grabiele M, Honfi A, Cerutti J, Fernandez V, Franco de Diana D, Daviña J. Cytogenetic analysis in the terrestrial orchid Sacoila argentina (Griseb.) Garay from Paraguay. Botanical Studies. 2010;51:337-342.

Sacoila argentina (Griseb.) Garay is a terrestrial orchid with ornamental value found in northern Argentina, Bolivia,... more Sacoila argentina (Griseb.) Garay is a terrestrial orchid with ornamental value found in northern Argentina, Bolivia, and Paraguay and is considered an object of conservation within the Paraguayan Chaco region, only found at Boqueron Department and chromosomally unknown until this study. Here, we present another natural population of Sacoila argentina for Paraguay (Paraguari Department, Villa Florida, 57°07'48.71" W - 26°23'32.16" S) so extending its area of distribution. Conventional cytogenetic techniques were applied in order to analyze its genetic system. Sacoila argentina is a diploid species with 2n = 2x = 46 small size chromosomes (1.21 - 4.45 μm) and 40.63 μm per haploid genome. Its karyotype, composed of 38m + 8sm, is bimodal (A2=0.36/R=3.69) due to a pair (# 20, sm) that is more than two times larger than the mean length of the chromosome (1.77 μm), and symmetric (Ai=0.18/i=44.58/r>2=0.13) belonging to Stebbins category 2B. The chromosome pair # 20 also carries a terminal macrosatellite on its short arm with an active NOR. Sporogenesis is normal and pollen grain viability is high (80%). Meiotic behaviour is regular and chromosomes pair up as 23 bivalents in the male (pollen mother cells, PMC) as they do in the female meiosis (megaspore mother cells, MMCs), confirming the basic number x = 23 for Sacoila. In PMCs and MMCs at diakinesis/metaphase I, ring bivalents (80%) with distal chiasmata (85%) are common, and the mean of chiasmata per bivalent is high (1.80) in both germinal lines. The recombination index, affected by the meiotic number (n = 23) and the mean of chiasmata/cell (41.5) is high (RI=64.5). Natural populations of Sacoila argentina possess low density, are scarce, interspersed and just found at flowering time. For these reasons, it is a rarely collected species.

Cell Damage in a Pediatric Population Potentially Exposed to Pesticides

by Virginia Fernandez Peralta

Benitez-Leite S, Macchi M, Fernandez V, Franco de Diana D, Ferro E, Mojoli A, et al. Cell Damage in a Pediatric Population Potentially Exposed to Pesticides. Pediatria. 2010;37(2):97-106.

Pesticides can cause acute or chronic effects on human health. Many pesticides can cause damage to genetic material.... more Pesticides can cause acute or chronic effects on human health. Many pesticides can cause damage to genetic material. These changes in genetic information have been associated with an increased risk of cancer. The objective of this study is to investigate damage to genetic material in a population of children potentially exposed to pesticides in the environment. The study design was observational and cross sectional. We studied 48 children potentially exposed to pesticides and 46 unexposed children. Samples of the oral mucosa were obtained to determine damage to genetic material using micronucleus frequency (MN).Higher average micronucleus counts were found in the group potentially exposed to pesticides (5.1±2.9 vs. 1.8±2.0, p <0.0001), along with a higher average of binucleate cells (3.5±2.7 vs. 1.4±1.4 p <0.0001), higher frequency of karyorrhexis (18.2±18.4 vs. 5.8± 18.4, p <0.004) and pyknosis (24.8±18.0 vs. 17.1±8.3; p <0.03).Of the children potentially exposed to pesticides, 40% (19/47) had an exposure time of 6 years. This study provides evidence of genetic damage in the population potentially exposed to pesticides in the environment.