Prevalence of taurodontism in premolars

Taurodontism does not involve molar teeth exclusively. To call attention to the occurrence of this phenomenon in premolars, 4,459 extracted mandibular and maxillary premolars were examined. Eleven showed evidence of taurodontism. Roentgenograms taken from a buccolingual direction confirmed the diagnosis of taurodont teeth.

Genetic susceptibility to bleomycin: A twin study

The frequency of chromatid breaks was analysed in peripheral lymphocytes obtained from sixteen healthy monozygotic (MZ) and sixteen healthy dizygotic (DZ) pairs of twins. In addition, increases in the frequency of chromatid breaks, following in vitro treatment of whole blood with 0.03 unit/ml bleomycin (BLM), were analysed in the same twins. There was a highly significant intrapair difference in the variance of the frequency of chromatid breaks among MZ and DZ twins, before and after BLM treatment. The coefficient of heritability was 85,5% and it was concluded that genetic factors contributed significantly to the individual variation observed in BLM induced chromatid break rates.

Molecular and Cytogenetic Analyses on Brazilian Youths with Pervasive Developmental Disorders

The Pervasive Developmental Disorders (PDDs) constitute a group of behavioral and neurobiological impairment conditions whose main features are delayed communicative and cognitive development. Genetic factors are reportedly associated with PDDs and particular genetic abnormalities are frequently found in specific diagnostic subgroups such as the autism spectrum disorders. This study evaluated cytogenetic and molecular parameters in 30 youths with autism or other PDDs. The fragile X syndrome was the most common genetic abnormality detected, presented by 1 patient with autism and 1 patient with PPD not-otherwise specified (PPD-NOS). One girl with PDD-NOS was found to have tetrasomy for the 15q11-q13 region, and one patient with autism exhibited in 2/100 metaphases an inv(7)(p15q36), thus suggesting a mosaicism 46,XX/46,XX,inv(7)(p15q36) or representing a coincidental finding. The high frequency of chromosomopathies support the hypothesis that PDDs may develop as a consequence to chromosomal abnormalities and justify the cytogenetic and molecular assessment in all patients with PDDs for establishment of diagnosis.

Transmission analysis of candidate genes for nonsyndromic oral clefts in Brazilian parent-child triads with recurrence

Cleft lip and/or palate (CL/P) is a major congenital defect with complex etiology, including multiple genetic and environmental factors. Approximately two thirds of the cases are not accompanied by other anomalies and are called nonsyndromic (NS). In the present study, we performed transmission distortion analysis of the MSX1-CA, TGFB3-CA and MTHFR-C677T polymorphisms in 60 parent-child triads, in which the NS-CL/ P affected child had at least one affected parent. No association with genes MSX1 or TGFB3 was found, but the results were suggestive of an association of the MTHFR-C677T polymorphism with NS-CL/P. © 2006 Sociedade Brasileira de Genética.

Genetic and modifying factors that determine the risk of brain tumors

Some modifying factors may determine the risk of brain tumors. Until now, it could not be attempted to identify people at risk and also to improve significantly disease progression. Current therapy consists of surgical resection, followed by radiation therapy and chemotherapy. Despite of these treatments, the prognosis for patients is poor. In this review, we highlight general aspects concerning genetic alterations in brain tumors, namely astrocytomas, glioblastomas, oligodendrogliomas, medulloblastomas and ependymomas. The influence of these genetic alterations in patients' prognosis is discussed. Mutagen sensivity is associated with cancer risk. The convincing studies that linked DNA damages and DNA repair alterations with brain tumors are also described. Another important modifying factor is immunity. General immune response against cancer, tumor microenvironment and immune response, mechanisms of tumor escape, CNS tumor immunology, immune defects that impair anti-tumor systemic immunity in brain tumor patients and local immunosuppressive factors within CNS are also reviewed. New hope to treatment perspectives, as dendritic-cell-based vaccines is summarized too. Concluding, it seems well established that there is association between brain tumor risk and mutagen sensivity, which is highly heritable. Primary brain tumors cause depression in systemic host immunity; local immunosuppressive factors and immunological characteristics of tumor cells may explain the poor prognosis and DNA damages responses can alert immune system. However, it is necessary to clarify if individuals with both constitutional defects in immune functions and genetic instability have higher risk of developing brain tumors. Cytogenetic prospective studies and gene copy number variations analysis also must be performed in peripheral lymphocytes from brain tumor patients. © 2011 Bentham Science Publishers Ltd.

Dermatóglífos de mulheres obesas brasileiras

Study design: descriptive, observational, cross-sectional. Purpose: Obesity is a complex, multifactorial disease, including genetic and endocrine factors, demographic, socioeconomic, and epidemiological changes. It affects children, adults, and elderly persons. Searching respective hereditary risk indicators is increasing, mainly by applying simple and low-cost methodology. We included thus dermatoglyphics. Objective: To investigated 30 Brazilian women dermatoglyphic profiles, 46.1 ± 07.87 years old, and body fat % equal or higher than 30%. Results: Arch predominance, low loop frequency, and high amount of IV-finger whorls were observed, as well as frequency of rare palmar pattern in 2-interdigital area. Conclusions: Data confirm the variability of dermatoglyphics frequency in different population groups, revealing that the findings meant obesity, regardless of women's different personal characteristics. Thus, additional evidences on constitutional component of obesity have been accumulated.

The relative strength of nurture and nature.

Mode of access: Internet.

Hereditary genius: an inquiry into its laws and consequences /

Mode of access: Internet.

The external inheritance of man,

At head of title: University of Adelaide. Commemoration address 1926.

Hereditary genius: an inquiry into its laws and consequences,

Mode of access: Internet.

The family-history book,

Mode of access: Internet.

Piecing together evolution of the vertebrate endocrine system

One of the great challenges in biology is to understand how particular complex morphological and physiological characters originated in specific evolutionary lineages. In this article, we address the origin of the vertebrate hypothalamic-pituitary-peripheral gland (H-P-PG) endocrine system, a complex network of specialized tissues, ligands and receptors. Analysis of metazoan nucleotide and protein sequences reveals a patchwork pattern of H-P-PG gene conservation between vertebrates and closely related invertebrates (ascidians). This is consistent with a model of how the vertebrate H-P-PG endocrine system could have emerged in relatively few steps by gene family expansion and by regulatory and structural modifications to genes that are present in a chordate ancestor. Some of these changes might have resulted in new connections between metabolic or signaling pathways, such as the bridging of 'synthesis islands' to form an efficient system for steroid hormone synthesis.