Comparison of aquatic macrophyte community structure between natural wetlands and rice fields with different cultivation ages / Comparação da estrutura da comunidade de macrófitas aquáticas entre áreas úmidas naturais e arrozais com diferentes tempos de cultivo

Abstract Recent studies indicate that rice fields contribute to the conservation of aquatic plants, however, repeated cultivation can reduce the species diversity harbored by rice fields. Repeated tillage, agrochemical application and environmental homogeneity can reduce plant diversity and select for species more tolerant to disturbance. Our hypotheses were: 1) macrophyte richness and biomass decrease with increased rice crop age; and 2) macrophyte species of rice fields are a subsample of natural wetlands and species loss will increase with crop age. We investigated three rice fields of each different ages (old, intermediate and new ones) and three natural intermittent wetlands for this study. Each area was sampled four times throughout the rice cultivation cycle (off-season, initial growth, final growth and post-harvest). Our results showed that the mean macrophyte richness and biomass were similar between rice fields of different ages and lower than that of natural wetlands. Although species composition in the different-aged rice fields was not markedly different, there was nestedness in the rice fields as age increased. In this study, we verified that macrophyte richness and biomass in rice fields was lower than natural wetlands and the species composition was different among wetland types (rice fields and natural wetlands), however our hypothesis that species richness and biomass will decrease with crop age was not confirmed. All rice crops had similar macrophyte assemblage structure (richness, biomass and species composition). However, the another hypothesis tested was confirmed, macrophyte assemblage of rice fields is a subset of natural wetlands and as, the age of a rice field increases, the species that occur in older rice field are subsets of species that occur in younger ones.

Resumo Estudos recentes indicam que arrozais contribuem para a conservação de plantas aquáticas, entretanto cultivos repetidos podem reduzir a diversidade de espécies nos arrozais. Cultivos repetidos, aplicação de agrotóxicos e homogeneização ambiental podem reduzir a diversidade de plantas e selecionar espécies mais tolerantes a perturbações. Nossas hipóteses foram: 1) a riqueza e a biomassa de macrófitas reduzem com o aumento do tempo de cultivo dos arrozais; e 2) as espécies de macrófitas aquáticas dos arrozais são subamostras das áreas úmidas naturais e a perda de espécies aumentará com o tempo de cultivo. Nós investigamos três arrozais de cada uma das diferentes idades (antigos, intermediários e novos) e três áreas úmidas naturais temporárias. Cada área foi amostrada quatro vezes ao longo do ciclo de cultivo (resteva, crescimento inicial, crescimento final e pós-colheita). Nossos resultados indicaram que a riqueza e a biomassa média de macrófitas foram similares entre os arrozais de diferentes idades e menor do que nas áreas úmidas naturais. Embora a composição de espécies nos arrozais de diferentes idades não tenha sido marcadamente diferente, houve aninhamento nos arrozais e este aumentou com tempo de cultivo do arrozal. Neste estudo, nós verificamos que a riqueza e biomassa de macrófitas nos arrozais eram menores que nas áreas úmidas naturais e a composição de espécies era diferente entre os tipos de áreas úmidas (arrozais e áreas úmidas naturais), entretanto nossa hipótese de que a riqueza e a biomassa de macrófitas diminuiriam com a idade do cultivo não foi confirmada. Todos os arrozais foram similares quanto à estrutura da assembleia de macrófitas (riqueza, biomassa e composição de espécies). No entanto, a outra hipótese testada foi confirmada, a assembleia de macrófitas dos arrozais é um subconjunto das áreas úmidas naturais e, conforme aumenta a idade do arrozal, as espécies que ocorrem nos arrozais mais antigos são subconjuntos das espécies que ocorrem nos mais jovens.

Comparison of aquatic macrophyte community structure between natural wetlands and rice fields with different cultivation ages.

Recent studies indicate that rice fields contribute to the conservation of aquatic plants, however, repeated cultivation can reduce the species diversity harbored by rice fields. Repeated tillage, agrochemical application and environmental homogeneity can reduce plant diversity and select for species more tolerant to disturbance. Our hypotheses were: 1) macrophyte richness and biomass decrease with increased rice crop age; and 2) macrophyte species of rice fields are a subsample of natural wetlands and species loss will increase with crop age. We investigated three rice fields of each different ages (old, intermediate and new ones) and three natural intermittent wetlands for this study. Each area was sampled four times throughout the rice cultivation cycle (off-season, initial growth, final growth and post-harvest). Our results showed that the mean macrophyte richness and biomass were similar between rice fields of different ages and lower than that of natural wetlands. Although species composition in the different-aged rice fields was not markedly different, there was nestedness in the rice fields as age increased. In this study, we verified that macrophyte richness and biomass in rice fields was lower than natural wetlands and the species composition was different among wetland types (rice fields and natural wetlands), however our hypothesis that species richness and biomass will decrease with crop age was not confirmed. All rice crops had similar macrophyte assemblage structure (richness, biomass and species composition). However, the another hypothesis tested was confirmed, macrophyte assemblage of rice fields is a subset of natural wetlands and as, the age of a rice field increases, the species that occur in older rice field are subsets of species that occur in younger ones.

Grado de conocimiento del idioma guaraní en estudiantes de medicina en un hospital universitario de Paraguay / Knowledge of the Guarani language in medical students at a university hospital in Paraguay

INTRODUCCIÓN: Paraguay es un país bilingüe, y el conocimiento del idioma guaraní constituye una herramienta importante de comunicación en la relación médico-paciente. OBJETIVO: Dar cuenta del grado y los factores que determinan el conocimiento del idioma guaraní, en estudiantes de medicina de último año en un hospital universitario de Paraguay. MÉTODOS: Estudio observacional, transversal y analítico. En él se aplicó una encuesta anónima con cuestionario a los alumnos de último año de medicina de un hospital universitario de Paraguay. Se realizó un estudio descriptivo de las características basales de los estudiantes de medicina y de su grado de conocimiento del idioma guaraní. Se efectuó la prueba de Chi-cuadrado para comparar variables categóricas, y se aplicó un estudio de regresión logística para determinar factores que determinan el grado de conocimiento del idioma. RESULTADOS: Fueron encuestados 264 estudiantes. El 82% provenía de la capital, 72% realizó sus estudios preuniversitarios en Asunción. El 92% estudió guaraní en la educación primaria y secundaria; 67,9% no lo interpreta correctamente. El 8,5% entienden y se expresan totalmente en guaraní; de ellos el 86% refirió que su mayor aprendizaje del idioma fue en el hogar familiar. El 75,2% de los encuestados consideró que la educación primaria y secundaria no ayudó en el aprendizaje. El grado de conocimiento del idioma (habla y entiende el idioma guaraní correctamente), varía si el estudiante proviene del interior o de la capital (31,25% versus 2,5%; OR ajustado: 0,24, intervalo de confianza 95% de 0,06 a 0,92; p=0,003); y según la localidad de la escuela primaria y secundaria: interior versus capital (25,6 y 1% respectivamente; OR ajustado: 0,08; intervalo de confianza 95% de 0,01 a 0,53; p=0,009). CONCLUSIONES: El grado de conocimiento de los estudiantes del guaraní es menor, comparado con población general. Los que mejor se expresan y comprenden el idioma, nacieron o lo estudiaron en el interior del país. La mayoría considera de poco aporte la educación primaria y secundaria para el aprendizaje del guaraní. Siendo el idioma una herramienta importante de comunicación en la relación médico­paciente, y sabiendo que el guaraní es el idioma más hablado del país; se deberían implementar estrategias para su aprendizaje.

INTRODUCTION: Paraguay is a bilingual country and knowledge of the guarani language is an important communication tool for the doctor- patient relationship. OBJECTIVE: To determine the degree of and the factors that influence the knowledge of the Guaraní language in medical students at a University Hospital in Paraguay METHODS: Observational, cross-sectional, analytical study in which an anonymous questionnaire was applied to the final year medical students of a University Hospital of Paraguay. The baseline characteristics of the medical students and their degree of knowledge of the Guarani language were described. The association between the characteristics of the students and the degree of knowledge of the Guarani language was evaluated with the Chi square association test and the logistic regression model. RESULTS: We included 264 students in the survey. Eighty two percent come from the capital, 72% made their pre-university studies in the capital; 92% studied Guaraní in primary and secondary education; 67.9% do not interpret Guarani correctly; 8.5% understand and express themselves totally in Guaraní. Of these, 86% refer to have the greater learning of the language in their home; 75.2% of respondents believe that primary and secondary education did not help in learning the language. The degree of knowledge of the language (speaks and understands the Guarani language correctly) varies according to: the origin of the student, the inland regions or the capital (31.25% vs. 2.5%, adjusted OR = 0.24, 95% confidence interval: 0.06 to 0.92, p = 0.003); the location of primary and secondary school: inland versus capital (25.6% vs. 1%, adjusted OR: 0.08, 95% confidence interval: 0.01 to 0.53, p = 0.009). CONCLUSIONS: The degree of knowledge of the Guaraní language of the students is lower compared to the general population; those who best understand and express themselves were born or studied in the interior of the country. The majority considers that primary and secondary education contribute little in the learning of Guaraní. Since language is an important communication tool in the patient-doctor relationship and knowing that Guarani is the most spoken language in the country, strategies for its learning should be implemented.

Comparison of aquatic macrophyte community structure between natural wetlands and rice fields with different cultivation ages

Abstract Recent studies indicate that rice fields contribute to the conservation of aquatic plants, however, repeated cultivation can reduce the species diversity harbored by rice fields. Repeated tillage, agrochemical application and environmental homogeneity can reduce plant diversity and select for species more tolerant to disturbance. Our hypotheses were: 1) macrophyte richness and biomass decrease with increased rice crop age; and 2) macrophyte species of rice fields are a subsample of natural wetlands and species loss will increase with crop age. We investigated three rice fields of each different ages (old, intermediate and new ones) and three natural intermittent wetlands for this study. Each area was sampled four times throughout the rice cultivation cycle (off-season, initial growth, final growth and post-harvest). Our results showed that the mean macrophyte richness and biomass were similar between rice fields of different ages and lower than that of natural wetlands. Although species composition in the different-aged rice fields was not markedly different, there was nestedness in the rice fields as age increased. In this study, we verified that macrophyte richness and biomass in rice fields was lower than natural wetlands and the species composition was different among wetland types (rice fields and natural wetlands), however our hypothesis that species richness and biomass will decrease with crop age was not confirmed. All rice crops had similar macrophyte assemblage structure (richness, biomass and species composition). However, the another hypothesis tested was confirmed, macrophyte assemblage of rice fields is a subset of natural wetlands and as, the age of a rice field increases, the species that occur in older rice field are subsets of species that occur in younger ones.

Resumo Estudos recentes indicam que arrozais contribuem para a conservação de plantas aquáticas, entretanto cultivos repetidos podem reduzir a diversidade de espécies nos arrozais. Cultivos repetidos, aplicação de agrotóxicos e homogeneização ambiental podem reduzir a diversidade de plantas e selecionar espécies mais tolerantes a perturbações. Nossas hipóteses foram: 1) a riqueza e a biomassa de macrófitas reduzem com o aumento do tempo de cultivo dos arrozais; e 2) as espécies de macrófitas aquáticas dos arrozais são subamostras das áreas úmidas naturais e a perda de espécies aumentará com o tempo de cultivo. Nós investigamos três arrozais de cada uma das diferentes idades (antigos, intermediários e novos) e três áreas úmidas naturais temporárias. Cada área foi amostrada quatro vezes ao longo do ciclo de cultivo (resteva, crescimento inicial, crescimento final e pós-colheita). Nossos resultados indicaram que a riqueza e a biomassa média de macrófitas foram similares entre os arrozais de diferentes idades e menor do que nas áreas úmidas naturais. Embora a composição de espécies nos arrozais de diferentes idades não tenha sido marcadamente diferente, houve aninhamento nos arrozais e este aumentou com tempo de cultivo do arrozal. Neste estudo, nós verificamos que a riqueza e biomassa de macrófitas nos arrozais eram menores que nas áreas úmidas naturais e a composição de espécies era diferente entre os tipos de áreas úmidas (arrozais e áreas úmidas naturais), entretanto nossa hipótese de que a riqueza e a biomassa de macrófitas diminuiriam com a idade do cultivo não foi confirmada. Todos os arrozais foram similares quanto à estrutura da assembleia de macrófitas (riqueza, biomassa e composição de espécies). No entanto, a outra hipótese testada foi confirmada, a assembleia de macrófitas dos arrozais é um subconjunto das áreas úmidas naturais e, conforme aumenta a idade do arrozal, as espécies que ocorrem nos arrozais mais antigos são subconjuntos das espécies que ocorrem nos mais jovens.

Treatment of chronic patellar tendinopathy with autologous bone marrow stem cells: a 5-year-followup.

The purpose of this study is to determine if patients with chronic patellar tendinopathy will improve clinically after the inoculation of bone marrow mononuclear cells (BM-MNCs). Eight patients with chronic patellar tendinopathy were included. Patients averaged 24 years old (range 14-35). All patients were refractory to conservative treatment for at least 6 months before the procedure. BM-MNCs were harvested from the iliac bone crest and inoculated under ultrasound guide in the patellar tendon lesion. Improvement was assessed through established clinical scores and ultrasound. At 5-year followup, statistically significant improvement was seen for most clinical scores. Seven of eight patients said they would have the procedure again if they had the same problem in the opposite knee and were completely satisfied with the procedure. Seven of 8 patients thought that the results of the procedure were excellent. According to our results, inoculation of BM-MNCs could be considered as a potential therapy for those patients with chronic patellar tendinopathy refractory to nonoperative treatments.

Aquatic macrophyte and macroinvertebrate diversity and conservation in wetlands of the Sinos River basin.

Wetlands are important sites for biological conservation because they support rich biodiversity and present high productivity. Species-area relationship is an important tool in conservation planning and it has been extensively used for wetland management. This study had as aims: (1) to analyse macrophyte and macroinvertebrate diversity in the fragmented wetlands of the Sinos River basin; and (2) to investigate whether wetland areas could work as a tool for selecting the important habitats for biodiversity conservation. Throughout the study, 56 species of macrophytes and 57 taxa of macroinvertebrates were identified. Macrophyte richness was related to the wetland area, but macroinvertebrate richness, however, was not related to the wetland area. The macrophyte and macroinvertebrate composition were not related to the wetland area. Species composition varied between the regions of the basin and the difference in the species composition occurred mainly by the distribution of macroinvertebrates. With regard to the biodiversity conservation of the Sinos River basin, the wetland area must not be a priority criterion for choosing the important wetlands for conservation. The environmental policies for biodiversity conservation must include management actions focused also on the protection of small wetlands. Moreover, other criteria should be analysed in further research such as habitat diversity, hydroperiod, geographic distribution and connectivity.

Técnica e indicaciones de la resonancia magnética artrografía. Extremidad superior (I) / Magnetic resonance arthrography indications and technique (I). Upper limb

La resonancia magnética (RM) es el método de imagen más efectivo en el diagnóstico de la patología articular. La RM artrografía (RMA), con inyección intraarticular de gadolinio diluido o suero salino, ha ganado aceptación en los últimos tiempos. El líquido intraarticular facilita la detección de la patología articular al delinear las estructuras articulares, separar estructuras anatómicas antes adyacentes y llenar espacios potenciales que se originan o comunican con la articulación. La RMA proporciona información adicional sobre la integridad de las estructuras articulares, especialmente cartílago, fibrocartílagos y ligamentos. Ha demostrado su utilidad clínica en el hombro, donde se han centrado la mayoría de estudios. La detección de lesiones sutiles del complejo cápsulo-labral es fundamental en la valoración prequirúrgica. La RMA puede ser una técnica complementaria a la RM convencional en algunos casos y en otros ser la técnica de elección inicial. La RMA indirecta con administración de gadolinio endovenoso se basa en el realce del líquido articular que se produce por difusión desde la sinovial al espacio articular. Esta técnica ofrece mejores resultados en las articulaciones con menor capacidad de distensión, como la muñeca, tobillo, mano y pie. Este artículo revisa el papel actual de la RMA. Se hace especial hincapié en la articulación del hombro, donde su utilidad está más claramente establecida. Se describe también la utilidad de esta técnica en otras articulaciones, revisando los aspectos anatómicos más relevantes, la técnica y las aplicaciones

Magnetic resonance (MR) is the most effective imaging technique in the diagnosis of articular pathology. MR arthrography (MRA), with intra-articular injection of diluted gadolinium or physiological saline solution has become more common in recent years. The intra-articular fluid facilitates the detection of articular pathology by delineating the articular structures, separating adjacent anatomic structures, and filling potential spaces that originate in or communicate with the joint. MRA provides additional information about the integrity of the articular structures, especially cartilage, fibrocartilage, and ligaments. MRA has proven especially useful in the shoulder, where most of the studies have been centered. The detection of subtle lesions of the capsule/labrum complex is fundamental for presurgical evaluation. MRA can be used to complement conventional MR imaging in some cases and in others it is the initial technique of choice. Indirect MRA with intravenous gadolinium administration is based on the enhancement of articular fluid caused by diffusion from the synovial space to the articular space. This technique offers better results in articulations with less capacity for distension, such as the wrist, ankle, hand, and foot. This first part of two-part article reviews the current role of MRA in the upper limb. Special emphasis is placed on the shoulder joint, where its usefulness has been most clearly established. The usefulness of this technique in other joints is also described, reviewing the most important anatomic aspects, techniques and applications

Técnica e indicaciones de la resonancia magnética artrografía. Extremidad inferior (II) / Magnetic resonance arthrography indications and technique (II). Lower limb

La resonancia magnética (RM) es la técnica de imagen de elección en la valoración de la patología articular. La RM artrografía (RMA) consiste en la punción directa de la articulación con inyección intraarticular de gadolinio diluido o suero salino. La RMA produce distensión de los recesos capsulares, delinea las estructuras intraarticulares y separa estructuras de difícil valoración por estar anexas, con lo que se consigue mejorar la fiabilidad diagnóstica de la patología articular y periarticular. La RMA permite resolver eficazmente alguno de los problemas diagnósticos de la RM en la valoración de la patología articular, evitando realizar artroscopias diagnósticas y permitiendo un mejor planteamiento terapéutico. En las articulaciones mayores de la extremidad inferior (cadera, rodilla y tobillo) la RMA tiene unas indicaciones claramente establecidas, entre las que destacan la valoración de las lesiones del labrum acetabular en la cadera, el menisco operado de la rodilla y el estudio de los síndromes de «impingement» del tobillo. Este artículo revisa la utilidad actual de la RMA en las articulaciones de la cadera, rodilla y tobillo. Se revisan los aspectos anatómicos más relevantes, la técnica y las aplicaciones. Finalmente, se revisa la utilidad de esta técnica en patologías que pueden afectar a cualquier articulación del organismo como son las lesiones osteocondrales, cuerpos libres y patología sinovial

Magnetic resonance (MR) is the imaging technique of election in the evaluation of the articular pathology. MR arthrography (MRA) consists of the direct punction of the joint with intraarticular injection of diluted gadolinium or saline solution. MRA produces distention of the capsular recess, delineates the intraarticular structures and separates annexed structures of difficult evaluation, with which it is able to improve the reliability diagnoses of the articular and periarticular pathology. MRA allows to solve some of the diagnostic problems of conventional MR imaging in the evaluation of the articular pathology, avoiding to make unnecessary diagnostic arthroscopy and allowing a better therapeutic plan. In the greater joints of the inferior extremity (hip, knee and ankle) MRA has established indications standing out the evaluation of the injuries of the acetabular labrum of the hip, the operated meniscus of the knee and the study of the «impingement» syndromes of the ankle. This article reviews the present utility of the MRA in the hip, knee and ankle joints. The more relevant anatomical aspects, the technique and the applications are reviewed. Finally, the value of this technique in pathologies that can affect any joint of the organism such as osteochondral injuries, loose intraarticular bodies and synovial pathology is reviewed

[Magnetic resonance arthrography indications and technique (I). Upper limb]. / Técnica e indicaciones de la resonancia magnética artrografia. Extremidad superior (I).

Magnetic resonance (MR) is the most effective imaging technique in the diagnosis of articular pathology. MR arthrography (MRA), with intra-articular injection of diluted gadolinium or physiological saline solution has become more common in recent years. The intra-articular fluid facilitates the detection of articular pathology by delineating the articular structures, separating adjacent anatomic structures, and filling potential spaces that originate in or communicate with the joint. MRA provides additional information about the integrity of the articular structures, especially cartilage, fibrocartilage, and ligaments. MRA has proven especially useful in the shoulder, where most of the studies have been centered. The detection of subtle lesions of the capsule/labrum complex is fundamental for presurgical evaluation. MRA can be used to complement conventional MR imaging in some cases and in others it is the initial technique of choice. Indirect MRA with intravenous gadolinium administration is based on the enhancement of articular fluid caused by diffusion from the synovial space to the articular space. This technique offers better results in articulations with less capacity for distension, such as the wrist, ankle, hand, and foot. This first part of two-part article reviews the current role of MRA in the upper limb. Special emphasis is placed on the shoulder joint, where its usefulness has been most clearly established. The usefulness of this technique in other joints is also described, reviewing the most important anatomic aspects, techniques and applications.

[Magnetic resonance arthrography indications and technique (II). Lower limb]. / Técnica e indicaciones de la resonancia magnética artrografía. Extremidad inferior (II).

Magnetic resonance (MR) is the imaging technique of election in the evaluation of the articular pathology. MR arthrography (MRA) consists of the direct punction of the joint with intraarticular injection of diluted gadolinium or saline solution. MRA produces distention of the capsular recess, delineates the intraarticular structures and separates annexed structures of difficult evaluation, with which it is able to improve the reliability diagnoses of the articular and periarticular pathology. MRA allows to solve some of the diagnostic problems of conventional MR imaging in the evaluation of the articular pathology, avoiding to make unnecessary diagnostic arthroscopy and allowing a better therapeutic plan. In the greater joints of the inferior extremity (hip, knee and ankle) MRA has established indications standing out the evaluation of the injuries of the acetabular labrum of the hip, the operated meniscus of the knee and the study of the "impingement" syndromes of the ankle. This article reviews the present utility of the MRA in the hip, knee and ankle joints. The more relevant anatomical aspects, the technique and the applications are reviewed. Finally, the value of this technique in pathologies that can affect any joint of the organism such as osteochondral injuries, loose intraarticular bodies and synovial pathology is reviewed.

Intrachromosomal triplication of distal 7p.

A female infant who died at 2 years of age with growth and psychomotor retardation, wide anterior fontanelle, downward slanting palpebral fissures, large, simple ears, joint dislocation/contractures, recurrent infections, and severe pulmonary hypertension was found to have a de novo 7p+ chromosome. The G banding pattern was suggestive of a triplication of 7p21.3 and 7p22; results of fluorescence in situ hybridisation studies using a chromosome 7 specific library, a subtelomeric 7p repeat (109A6), and yeast artificial chromosome clones 786g1 and 850a1, which are respectively associated with the (CA)n repeat markers D7S517 and D7S513, supported the cytogenetic interpretation and showed that the middle repeat was inverted. The patient's phenotype was consistent with the 7p duplication syndrome, allowing for the effects of the extra burden introduced by the partial tetrasomy. The present rearrangement may have resulted from several meiotic events occurring at the four chromatid stage, namely an unequal crossover or interhomologue translocation with points of exchange at 7p22 and 7p15 followed by the inverted insertion of 7p21.3-->p21.2 at the former breakpoint junction; moreover, a further duplication including D7S517 within the terminal 7p22 band is also required.

Ag-positive regions on unusual chromosome locations.

A 28-year-old woman with a 46,XX,t(13;21)(q14;p11) karyotype showed both chromosome unstability and an unusual Ag-positivity on her chromosomes. Since there are reports about affinity of the NORs for broken chromosome ends, the two different phenomena observed in the present case are probably related.

Pure trisomy 17q from a 17;21 translocation.

We present a female patient with a trisomy 17q23-->qter whose clinical picture clearly illustrates the pure trisomy 17q syndrome.

Aneuploidies, chromosome aberrations and dominant gene mutations detected in 113,913 consecutive newborn children in Mexico.

Data on 113,913 liveborn children from a hospital in Guadalajara, Jalisco (Mexico), were analysed for birth defects (BD); mutation rates were calculated for sporadic aneuploidy, chromosome aberrations and dominant gene mutations. The results showed a general incidence of 13.92 BD cases per 1000 liveborns, of which 1.64% were chromosomal abnormalities, 1.50% were aneuploid, 0.14% were structural chromosome aberrations and 3.23% were dominant gene mutations. The mutation rates were 8.20 x 10(-4) chromosomal abnormalities, 7.5 x 10(-4) aneuploidies, 7.0 x 10(-5) chromosome aberrations and 1.61 x 10(-3) dominant gene mutations/gamete/generation, respectively. The lethality rate was 15.32% of the liveborns with BD. The described findings estimate the incidence of new human mutants detected at birth in a sample of the Mexican population. They show that the rate for some aneuploidies are similar to those found in other populations previously reported in the literature but the rates of chromosome and dominant gene mutations were different.

De novo dir dup (1)(q3200----4200) in an adult. Further delineation of the pure 1q trisomy syndrome.

An adult male patient with a "de novo" pure trisomy 1q32---q42 was studied. Literature review of 33 cases with 1q trisomy allowed singling out a distinctive phenotype by eliminating clinical features of concomitant aneusomies. It is concluded, however, that the clinical pictures of the "pure" and "impure" 1q trisomies are similar and that the critical segment includes bands q32 and q41.

Whole-arm t(X;17) (Xp17q;Xq17p) and gonadal dysgenesis. A further exception to the critical region hypothesis.

A 19-year-old female patient with gonadal dysgenesis and a de novo t(X;17) (Xp17q;Xq17p) is described. Since the critical segment Xq13----q26 was intact, this case is a further exception to the critical region hypothesis.

Aberraciones cromosómicas en 334 individuos con perdidas gestacionales diversas: (incluyendo 144 parejas) / Chromosome aberrations in 334 subjects with repeated abortion (including 144 comples)

La evaluación citogenética de 334 individuos (incluyendo 144 parejas) con abortos repetidos y/o pérdidas gestacionales diversas demostró una aberración cromosómica en 15 de los individuos (4.49%) y en 14 de las parejas (9.72%). La comparación de la frecuencia de anormalidades en individuos que no habían procreado hijos normales contra aquélla de los que sí lo habían hecho (5.62% vs. 1.18%) reveló una diferencia estadísticamente significativa (p<0.02). Estos datos apoyan la conveniencia de efectuar estudios citogenéticos parentales en la investigación etiológica de pérdidas gestacionales, particularmente cuando no ha habido descendencia normal. Tanto los resultados obtenidos como el tipo de anormalidades observadas (8 translocaciones recíprocas, 2 translocaciones Robertsonianas, 2 mosaicos para el cromosoma X, 1 inversión pericéntrica, 1 sitio frágil y 1 anillo no identificado en mosaico) fueron similares a los obtenidos por otros autores