Aug
29
2010
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Aiming at multidisciplinary consensus: what should be detected in prenatal diagnosis?

OBJECTIVE: To determine expert consensus on which chromosomal abnormalities should and should not be detected in prenatal diagnosis, and for which abnormalities disagreement remains after structured discussion.

METHODS: An expert panel of 24 prenatal experts (8 clinical cytogeneticists, 8 clinical geneticists and 8 obstetricians) rated 15 chromosomal abnormalities sampled from a nationwide study on rapid aneuploidy detection (RAD). In two individual anonymous rating rounds and one group meeting, the participants rated PRO or AGAINST detection and stated their main argument. The 15 chromosomal abnormalities were described in detail by a stylized vignette containing an obstetrical history, the indication for prenatal diagnosis and the range of possible outcomes of the chromosomal abnormality. Consensus was defined to be present if at least 80% of the experts agreed.

RESULTS: Consensus was reached in 12 out of 15 cases. In ten cases, there was agreement PRO detection and in two cases experts agreed AGAINST detection. At the end of the third round, dissensus remained on three abnormalities.

CONCLUSION: Experts largely agreed on detecting chromosomal abnormalities with severe consequences and AGAINST detection in case of irrelevant clinical consequences. For chromosomal abnormalities with mild or uncertain outcomes, dissensus remained. None of the currently available tests corresponds to these demands. Copyright (c) 2010 John Wiley & Sons, Ltd.

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Aug
29
2010
0

Introductory comments on special section-New developments in craniofacial biology: Putting on a happy face.

Approximately three quarters of children with birth defects have anomalies that affect the craniofacial structures. Defects in this area of the body result in lifelong disability, major challenges to families and society and often a serious effect on life expectancy. Surgery has been the primary intervention for these disorders, with frequently less than optimal outcomes and risk for additional morbidity and mortality. The challenge for clinicians caring for these children is to develop new methods for the treatment and prevention of these disorders. An understanding of the evolution of the head and the finely tuned temporospatial signaling pathways involved is critical to understanding the origins of the vertebrates as well as of human craniofacial malformations. In the future, these new approaches will be based upon our enhanced understanding of the developmental tool kit fashioned by evolution and the application of this knowledge toward the development of new diagnostic, pharmacologic, and genetic interventions for these disorders. (c) 2010 Wiley-Liss, Inc.

Written by admin in: Ischemic Brain Damage |
Aug
29
2010
0

Evidence for a recurrent microdeletion at chromosome 16p11.2 associated with congenital anomalies of the kidney and urinary tract (CAKUT) and Hirschsprung disease.

Congenital Anomalies of the Kidney and Urinary Tract can be associated with Hirschsprung disease. We report on three children with a similar 16p11.2 microdeletion with a spectrum of clinical anomalies consisting of congenital anomalies of the kidney and urinary tract in two patients (Patients 1 and 2) and Hirschsprung disease in two patients (Patients 1 and 3), leading us to hypothesize that a gene in this region is associated with these phenotypes. Patient 1 presented with left renal agenesis, grade-IV vesicoureteral reflux, and Hirschsprung disease, Patient 2 with left renal agenesis, chronic kidney disease, chronic constipation, seizures, and developmental delay, and Patient 3 with Hirschsprung disease and normal kidneys. Genome-wide microarray analysis demonstrated overlapping microdeletions within 16p11.2. The shortest region of overlap in the three patients contained only eight genes, including the SH2 domain-containing binding protein 1 (SH2B1), an adaptor protein which has been implicated in enhancement of the tyrosine kinase activity of RET, whose role in developmental disease of the kidney and enteric enervation is well established. Our findings suggest that 16p11.2 deletions are associated with abnormalities of renal and enteric development and we hypothesize that deletion of SH2B1 may account for the observed phenotype. (c) 2010 Wiley-Liss, Inc.

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Aug
29
2010
0

A small supernumerary marker chromosome, derived from chromosome 22, possibly associated with repeated spontaneous abortions.

We report a phenotypically normal couple with repeated spontaneous abortions and without other clinical features. Clinical, hematological, biochemical, and endocrinological aspects of the couple did not reveal any abnormalities. The karyotype of the wife was normal (46,XX), while the husband was found to have an abnormal karyotype, 47,XY,+der(22)mat. The marker chromosome was familial and non-satellite. Although the potential risk of small supernumerary marker chromosomes for spontaneous abortions cannot be defined precisely, marker chromosomes, together with methods used for ascertainment, are also factors to be considered when investigating infertility consequences. Furthermore, identification of the origin of a marker chromosome may provide additional information for patient karyotype-phenotype correlations. Further studies, such as molecular analyses to identify the breakpoint, are necessary for investigating phenotype-genotype correlations and assessment of genetic risks for small secondary chromosomes. The cause of repeated spontaneous abortions in this couple might be the presence of this marker chromosome in the husband. Consequently, we recommended genetic counseling before further pregnancies.

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Aug
29
2010
0

Neurological Manifestations in Individuals with Pure Cutaneous or Syndromic (Ruggieri-Happle Syndrome) Phenotypes with “Cutis Tricolor”: A Study of 14 Cases.

BACKGROUND: The term CUTIS TRICOLOR describes the combination of congenital hyper- and hypo-pigmented skin lesions in close proximity to each other in a background of normal complexion. This phenomenon has been reported so far: (i) as pure cutaneous trait, (ii) as a part of a complex malformation syndrome (Ruggieri-Happle syndrome – RHS), (iii) as a distinct type (cutis tricolor parvimaculata); (iv) in association with other (e. g., vascular) skin disturbances.

AIM: The aim of this study was to define the spectrum of neurological abnormalities in cutis tricolor.

METHODS: A retrospective and prospective 14-year study of clinical, electroencephalographic (EEG), neuroradiological (MRI), cytogenetic and ZFHX1B gene studies of 14 individuals (8 M, 6 F; aged 2-28 years) with cutis tricolor (4 pure cutaneous; 10 syndromic) was undertaken.

RESULTS: Neurological involvement was recorded in 71.4% (10/14) of the patients [100% (10/10) in RHS and null (0/4) in cases with isolated skin manifestations] and included psychomotor delay (n=8), seizures (n=9), EEG abnormalities (n=6), a behavioural phenotype (n=4), non-specific brain abnormalities (n=6). Genetic analyses excluded ZFHX1B mutations and revealed a 19qter deletion (n=1).

CONCLUSIONS: Even though we could not exclude the ascertainment and referral biases, we concluded that cutis tricolor may be a marker of underlying neurological involvement particularly in subjects with a syndromic (RHS) phenotype.

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Aug
29
2010
0

Prevalence of hematological abnormalities in patients with Sheehan’s syndrome: response to replacement of glucocorticoids and thyroxine.

Anemia and other hematological abnormalities are common in patients with Sheehan’s syndrome. The response of these abnormalities to replacement of thyroxine and glucocorticoids is not clear. The aim of the present study was to document the profile of hematological abnormalities and response to treatment in patients with Sheehan’s syndrome. Forty patients of Sheehan’s syndrome and an equal number of age and parity matched healthy controls were studied for prevalence of hematological abnormalities. Hemoglobin concentration, hematocrit, red cell, white cell and platelet count were significantly decreased in patients with Sheehan’s syndrome compared to controls. Frequency of anemia, leucopenia, thrombocytopenia and pancytopenia was significantly higher in these patients compared to controls. After achieving euthyroid and eucortisol state, there was a complete recovery of these hematological abnormalities. We conclude that anemia and other cytopenias are common in patients with Sheehan’s syndrome and replacement with thyroxine and glucocorticoids results in complete recovery of these abnormalities.

Written by admin in: Ischemic Brain Damage |
Aug
29
2010
0

Volumetric analysis of functional diffusion maps is a predictive imaging biomarker for cytotoxic and anti-angiogenic treatments in malignant gliomas.

Anti-angiogenic agents targeting brain tumor neovasculature may increase progression-free survival in patients with recurrent malignant gliomas. However, when these patients do recur it is not always apparent as an increase in enhancing tumor volume on MRI, which has been the standard of practice for following patients with brain tumors. Therefore alternative methods are needed to evaluate patients treated with these novel therapies. Furthermore, a method that can also provide useful information for the evaluation of conventional therapies would provide an important advantage for general applicability. Diffusion-weighted magnetic resonance imaging (DWI) has the potential to serve as a valuable biomarker for these purposes. In the current study, we explore the prognostic ability of functional diffusion maps (fDMs), which examine voxel-wise changes in the apparent diffusion coefficient (ADC) over time, applied to regions of fluid-attenuated inversion recovery (FLAIR) abnormalities in patients with malignant glioma, treated with either anti-angiogenic or cytotoxic therapies. Results indicate that the rate of change in fDMs is an early predictor of tumor progression, time to progression and overall survival for both treatments, suggesting the application of fDMs in FLAIR abnormal regions may be a significant advance in brain tumor biomarker technology.

Written by admin in: Ischemic Brain Damage |
Aug
29
2010
0

Diagnostic methods for feline coronavirus: a review.

Feline coronaviruses (FCoVs) are found throughout the world. Infection with FCoV can result in a diverse range of signs from clinically inapparent infections to a highly fatal disease called feline infectious peritonitis (FIP). FIP is one of the most serious viral diseases of cats. While there is neither an effective vaccine, nor a curative treatment for FIP, a diagnostic protocol for FCoV would greatly assist in the management and control of the virus. Clinical findings in FIP are non-specific and not helpful in making a differential diagnosis. Haematological and biochemical abnormalities in FIP cases are also non-specific. The currently available serological tests have low specificity and sensitivity for detection of active infection and cross-react with FCoV strains of low pathogenicity, the feline enteric coronaviruses (FECV). Reverse transcriptase polymerase chain reaction (RT-PCR) has been used to detect FCoV and is rapid and sensitive, but results must be interpreted in the context of clinical findings. At present, a definitive diagnosis of FIP can be established only by histopathological examination of biopsies. This paper describes and compares diagnostic methods for FCoVs and includes a brief account of the virus biology, epidemiology, and pathogenesis.

Written by admin in: Ischemic Brain Damage |
Aug
29
2010
0

Mitochondrial Function and Insulin Resistance during Aging – A Mini-Review.

Background: Insulin resistance, i.e. impaired insulin sensitivity, and type 2 diabetes are more prevalent in elderly humans. Both conditions relate to lower aerobic performance and increased body fatness, which have been linked to reduced mitochondrial oxidative capacity. Thus, lower insulin sensitivity in the elderly could result from age-related diminished energy metabolism or from lifestyle-related abnormalities. Objective: This review addresses the question whether insulin sensitivity and mitochondrial oxidative capacity are independently affected during aging and type 2 diabetes. Methods: Only studies were analyzed which included elderly persons and employed state-of-the-art methodology to assess insulin sensitivity and oxidative capacity, e.g. electron microscopic imaging, in vivo magnetic resonance spectroscopy or ex vivo high-resolution respirometry. Results: Humans with or at risk of type 2 diabetes frequently exhibit insulin resistance along with structural and functional abnormalities of muscular mitochondria. Low mitochondrial oxidative capacity causes muscular fat accumulation, which impedes insulin signaling via lipid intermediates, in turn affecting oxidative capacity. However, insulin sensitivity is not generally reduced with age, when groups are carefully matched for physical activity and body fatness. Moreover, lifestyle intervention studies revealed discordant responses of mitochondrial oxidative capacity and insulin sensitivity. Conclusions: In the elderly, low mitochondrial oxidative capacity likely results from age-related effects acquired during life span. Insulin resistance occurs independently of age mostly due to unhealthy lifestyle on top of genetic predisposition. Thus, insulin sensitivity and mitochondrial function may not be causally related, but mutually amplify each other during aging.

Written by admin in: Ischemic Brain Damage |
Aug
29
2010
0

Congenital absence of the posterior arch of the atlas associated with a fracture of the anterior arch.

Structural defects of the posterior arch of the atlas are rare, and range from clefts of variable location and size to more extensive defects such as complete agenesis. These abnormalities are usually incidental radiological findings. We present a case of a fracture of the anterior arch of the atlas associated with a congenital abnormality of the posterior arch.

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