Jun
18
2009
0

Sudden unexpected neonatal death in the first week of life: autopsy findings from a specialist centre.

OBJECTIVE: Sudden unexpected early neonatal death (SUEND) in the first week of life shares features with sudden unexpected death in infancy (SUDI) but is not included as SUDI, which is limited to post-perinatal deaths. The aim of this study was to review SUEND autopsies performed in a single specialist centre over a 10-year period, (1996-2005). METHODS: Retrospective analysis of >1500 consecutively performed paediatric autopsies performed by paediatric pathologists at one centre conducted according to a standard protocol including ancillary investigations. SUENDs were identified and autopsy findings reviewed. RESULTS: Of 1516 post-mortem examinations, 180 were first-week neonatal deaths, 55 (31%) presenting as SUEND. Thirty-two (58%) were explained following autopsy, whilst the remainder were unexplained; most deaths during sleep were associated with adult co-sleeping. Around 40% of explained deaths were associated with undiagnosed congenital abnormalities, mainly congenital heart disease. In addition, there were nine infection-related deaths and three deaths from unsuspected metabolic disease (fatty acid oxidation defects). CONCLUSION: There are distinct differences between SUEND and SUDI, with significantly more explained deaths in the former and a much greater proportion due to congenital abnormalities and metabolic disease.

Written by admin in: Ischemic Brain Damage |
Jun
18
2009
0

Minimal hepatic encephalopathy.

Minimal hepatic encephalopathy (MHE) is the mildest form of spectrum of hepatic encephalopathy (HE). Patients with MHE have no recognizable clinical symptoms of HE but have mild cognitive and psychomotor deficits. The prevalence of MHE is high in patients with cirrhosis of liver and varies between 30% and 84%; it is higher in patients with poor liver function. The diagnostic criteria for MHE have not been standardized but rest on careful patient history and physical examination, normal mental status examination, demonstration of abnormalities in cognition and/or neurophysiological function, and exclusion of concomitant neurological disorders. MHE is associated with impaired health-related quality of life, predicts the development of overt HE and is associated with poor survival. Hence, screening all patients with cirrhosis for MHE using psychometric tests, and treatment of those patients diagnosed to have MHE has been recommended. Ammonia plays a key role in the pathogenesis of MHE, which is thought to be similar to that of overt HE. Thus, ammonia-lowering agents such as lactulose and probiotics have been tried. These agents have been shown to improve cognitive and psychometric deficits, and have good safety profile. Future studies will better define the role of other drugs, such as rifaximin, acetyl L-carnitine and L-ornithine L-aspartate.

Written by admin in: Ischemic Brain Damage |
Jun
18
2009
0

Thrombosis after kidney transplantation.

The diagnosis of deep vein thrombosis (DVT) is unusual in patients with sickle cell disease (SCD). Despite the incidence of cerebral thrombosis in SCD patients due to vasooclusion, thrombotic manifestations in peripheral vessels are rare. Patients with homozygous SCD present a variety of renal abnormalities as a result of sickle crisis. In this group of patients, kidney transplantation has been performed in the renal endstage patients; with graft survival rates similar to that of the general transplant population at 1 year. However, patients with SCD experience an augmentation in the frequency of painful crises in the first year after transplantation, which has been attributed to concurrent elevations in hematocrit and plasma viscosity. Despite etiology, renal transplant patients are at increased risk for the development of thromboembolic events such as deep vein thrombosis and renovascular thrombosis after allograft procedure. These events can be due to a prothrombotic state generated by the use of immunosuppressive agents. Although other factors such as acquired or inherited disorders of the clotting system may increase the risk of thrombosis. Here, we report a case of a renal transplant patient with sickle cell disease who presented recurrent episodes of DVT and increase painful sickle episodes after kidney transplantation.

Written by admin in: Ischemic Brain Damage |
Jun
18
2009
0

Characterization of congenital anomalies in individuals with choanal atresia.

OBJECTIVE: To review a tertiary care pediatric hospital’s experience with choanal atresia and stenosis (CA/S) related to associated congenital anomalies (birth defects, including minor abnormalities) and genetic disorders. DESIGN: Retrospective case series. SETTING: Tertiary care pediatric hospital. PATIENTS: Individuals with CA/S. MAIN OUTCOME MEASURES: Identification of congenital anomalies, neurologic abnormalities, and developmental disabilities in individuals with CA/S. RESULTS: One hundred twenty-nine individuals with CA/S were evaluated between July 1, 1997, and July 1, 2007. Choanal atresia and stenosis was an isolated finding in 34 patients (26.4%) and was associated with other anomalies in 95 patients (73.6%). Specific conditions were diagnosed in 66 patients (51.2%); CHARGE (coloboma, heart defect, atresia choanae, retarded growth, genitourinary abnormalities, and ear anomalies) syndrome was the most common diagnosis (33 patients [25.6%]). Numerous conditions were seen, including chromosomal abnormalities, single-gene defects, deformations, and those caused by teratogens. Choanal atresia and stenosis was unilateral in 62 patients (48.1%) and was bilateral in 60 patients (46.5%). Unilateral cases were more likely to be isolated (30 patients [53.2%]). Bilateral cases were more likely to be associated with specific disorders or multiple congenital anomalies (60 patients [98.4%]). There was no difference in laterality among unilateral cases. CONCLUSIONS: Choanal atresia and stenosis is associated with a wide range of disorders. Congenital anomalies, neurologic abnormalities, and developmental disabilities are commonly identified in affected individuals. Bilateral CA/S is more commonly seen in patients in whom specific diagnoses or other congenital anomalies are identified. Unilateral CA/S occurs more frequently in isolated cases. A comprehensive evaluation is recommended in individuals with CA/S to evaluate for other congenital anomalies, neurologic abnormalities, developmental delays, and evidence of a specific underlying disorder.

Written by admin in: Ischemic Brain Damage |
Jun
18
2009
0

Chronic kidney disease and bisphosphonate treatment: are prescribing guidelines unnecessarily restrictive?

The prevalence of both osteoporosis and chronic kidney disease (CKD) increases with advancing age. Bisphosphonates are effective in the prevention and treatment of osteoporosis but current recommendations limit their use in patients with renal impairment because of concern regarding the safety profile of these agents in the setting of reduced renal function. The appropriateness of bisphosphonate treatment for patients with CKD is also in question since CKD is independently associated with a variety of skeletal abnormalities, collectively termed renal osteodystrophy, including pre-existing low bone turnover. The evidence to support the current prescribing restrictions is not robust and there are some data to suggest both that bisphosphonate treatment reduces fracture risk without an increase in adverse events in patients with CKD, and that in clinical practice there is underutilisation of this treatment in early CKD. Appropriate prospective trial data with clinically important end points in CKD patients is awaited.

Written by admin in: Ischemic Brain Damage |
Jun
18
2009
0

Clinical and cytogenetic features of a population-based consecutive series of 285 pediatric T-cell acute lymphoblastic leukemias: Rare T-cell receptor gene rearrangements are associated with poor outcome.

Clinical characteristics and cytogenetic aberrations were ascertained and reviewed in a population-based consecutive series of 285 pediatric T-cell acute lymphoblastic leukemias (T-ALLs) diagnosed between 1992 and 2006 in the Nordic countries. Informative karyotypic results were obtained in 249 (87%) cases, of which 119 (48%) were cytogenetically abnormal. Most (62%) of the aberrant T-ALLs were pseudodiploid. Structural changes were more common than numerical ones; 86% displayed at least one structural abnormality and 41% at least one numerical anomaly. The most frequent abnormalities were T-cell receptor (TCR) gene rearrangements (20%) [TCR;11p13 (10%), TCR;10q24 (3%), TCR;other (8%)], del(9p) (17%), +8 (14%), del(6q) (12%), and 11q23 rearrangements (6%). The TCR;other group comprised the rare rearrangements t(X;14)(p11;q11), t(X;7)(q22;q34), t(1;14)(p32;q11), ins(14;5)(q11;q?q?), inv(7)(p15q34), t(8;14)(q24;q11), t(7;11)(q34;p15), and t(12;14)(p13;q11). The clinical characteristics of this Nordic patient cohort agreed well with previous larger series, with a median age of 9.0 years, male predominance (male/female ratio 3.1), median white blood cell (WBC) count of 66.5 x 10(9)/l, and a high incidence of mediastinal mass and central nervous system involvement (59% and 9.5%, respectively). These features did not differ significantly among the various genetic subgroups. 5-year event-free survival (EFS) and overall survival for all patients were 0.61 (+/-0.03) and 0.67 (+/-0.03), respectively. In a multivariate analysis, two factors affected negatively the EFS, namely a WBC count of >/=200 x 10(9)/l (P < 0.001) and the presence of rare TCR rearrangements (P = 0.001). In conclusion, in this large series of childhood T-ALLs from the Nordic countries, the cytogenetic findings were not associated with risk of therapy failure with the exception of the TCR;other group. However, further prospective and collaborative investigations of this genetically heterogeneous entity are needed to confirm these results. (c) 2009 Wiley-Liss, Inc.

Written by admin in: Ischemic Brain Damage |
Jun
18
2009
0

Ror-family receptor tyrosine kinases in noncanonical Wnt signaling: Their implications in developmental morphogenesis and human diseases.

The Ror-family receptor tyrosine kinases (RTKs) play crucial roles in the development of various organs and tissues. In mammals, Ror2, a member of the Ror-family RTKs, has been shown to act as a receptor or coreceptor for Wnt5a to mediate noncanonical Wnt signaling. Ror2- and Wnt5a-deficient mice exhibit similar abnormalities during developmental morphogenesis, reflecting their defects in convergent extension movements and planar cell polarity, characteristic features mediated by noncanonical Wnt signaling. Furthermore, mutations within the human Ror2 gene are responsible for the genetic skeletal disorders dominant brachydactyly type B and recessive Robinow syndrome. Accumulating evidence demonstrate that Ror2 mediates noncanonical Wnt5a signaling by inhibiting the beta-catenin-TCF pathway and activating the Wnt/JNK pathway that results in polarized cell migration. In this article, we review recent progress in understanding the roles of noncanonical Wnt5a/Ror2 signaling in developmental morphogenesis and in human diseases, including heritable skeletal disorders and tumor invasion. Developmental Dynamics, 2009. (c) 2009 Wiley-Liss, Inc.

Written by admin in: Ischemic Brain Damage |
Jun
18
2009
0

Central nervous system regeneration: from leech to opossum.

A major problem of neurobiology concerns the failure of injured mammalian spinal cord to repair itself. This review summarizes work done on two preparations in which regeneration can occur: the central nervous system of an invertebrate, the leech, and the spinal cord of an immature mammal, the opossum. The aim is to understand cellular and molecular mechanisms that promote and prevent regeneration. In the leech, an individual axon regrows successfully to re-establish connections with its synaptic target, while avoiding other neurons. Functions that were lost are thereby restored. Moreover, pairs of identified neurons become re-connected with appropriate synapses in culture. It has been shown that microglial cells and nitric oxide play key roles in leech CNS regeneration. In the opossum, the neonatal brain and spinal cord are so tiny that they survive well in culture. Fibres grow across spinal cord lesions in neonatal animals and in vitro, but axon regeneration stops abruptly between postnatal days 9 and 12. A comprehensive search has been made in spinal cords that can and cannot regenerate to identify genes and establish their locations. At 9 days, growth-promoting genes, their receptors and key transcription molecules are up-regulated. By contrast at 12 days, growth-inhibitory molecules associated with myelin are prominent. The complete sequence of the opossum genome and new methods for transfecting genes offer ways to determine which molecules promote and which inhibit spinal cord regeneration. These results lead to questions about how basic research on mechanisms of regeneration could be ‘translated’ into effective therapies for patients with spinal cord injuries.

Written by admin in: Brain Damage |
Jun
18
2009
0

Increased Maternal/Fetal Blood S100B Levels Following Systemic Endotoxin Administration and Periventricular White Matter Injury in Preterm Fetal Sheep.

Objective. Intrauterine infection is suggested to cause perinatal brain white matter injury. In the current study, we evaluated whether S100B, a brain damage marker, may be also assessed in maternal bloodstream after white matter injury induced by fetal intravenous application of lypopolisaccharide (LPS) endotoxin. Methods. Fourteen fetal sheeps were chronically catheterized at a mean gestational age of 107 days. Three days after surgery, fetuses (n = 7) received 500 ng of LPS or 2 mL 0.9% saline (n = 7) intravenously (IV). Lypopolisaccharide and placebo groups were monitored by continuous hemodynamic data recordings and at 6 predetermined time points (control value; 3, 6, 24, 48, and 72 hours after LPS/placebo administration) blood was drawn for laboratory parameters and S100B assessment. Brain damage was evaluated by light microscopy after Klüver-Barrera staining. Selected areas of the periventricular white matter were also examined by electron microscopy. Results. White matter injury was detected in all LPS-treated fetuses, whereas no abnormalities were seen in control animals or in LPS-treated mothers. Maternal and fetal S100B protein levels were significantly higher in the LPS group than in the control group at all monitoring time points (P < .001). The highest fetal-maternal S100B levels were observed at 3-hour time-point (P < .001). Conclusions. We found that S100B protein is increased in the maternal district in presence of fetal periventricular brain white matter injury induced by endotoxin. The present data offer additional support for S100B assessment in the maternal circulation in pregnancies complicated by intrauterine infection at risk of white matter injury.

Written by admin in: Brain Damage |
Jun
18
2009
0

Adenosine A(2A) receptor deficiency exacerbates white matter lesions and cognitive deficits induced by chronic cerebral hypoperfusion in mice.

Adenosine A(2A) receptor inactivation consistently protects against acute ischemic brain injury; however, the role of the A(2A) receptor in chronic cerebral ischemia is unknown. To elucidate that, chronic cerebral hypoperfusion model was established by permanent stenosis of bilateral common carotid artery in A(2A) receptor knock-out mice and their wild-type littermates in this study. White matter lesions were observed after stenosis of common carotid arteries in both A(2A) receptor knock-out mice and wild-type mice. The demyelination-related damage and proliferation of astrocytes and microglia in white matter was observed more seriously in A(2A) receptor knock-out mice compared with that in wild-type mice. Working memory was also more seriously impaired in A(2A) receptor knock-out mice relative to wild-type mice. The mRNA expression and protein level of proinflammatory cytokines, including tumor necrosis factor-alpha (TNF-alpha), interleukin-1beta (IL-1beta), and interleukin-6 (IL-6) increased more remarkably in the corpus callosum in the A(2A) receptor knock-out mice. In conclusion, inactivation of the A(2A) receptor exacerbates the white matter lesions and cognitive deficits induced by chronic cerebral hypoperfusion, and this effect may be associated with increased expression of the proinflammatory cytokines in the white matter.

Written by admin in: Brain Damage |

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