The association between fetal nasal bone hypoplasia and aneuploidy

OBJECTIVE: To determine the association between fetal nasal bone hypoplasia and aneuploidy in women undergoing prenatal diagnosis. METHODS: A prospective cohort study involving women undergoing chorionic villus sampling and amniocentesis for an increased risk of aneuploidy. Fetal biometric and nasal bone measurements were obtained at the time of prenatal diagnosis and compared with karyotypes. Nasal bone hypoplasia was defined as nasal bone less than 2.5th percentile for the gestational age. RESULTS: A total of 632 fetuses were evaluated. Twenty-nine (4.6%) had an aneuploidy (18 trisomy 21, 5 trisomy 18, 1 Turner's syndrome, one Marker chromosome 1, 2 sex chromosome anomalies, and 2 triploidy). Nasal bone measurements were documented in 29 aneuploid fetuses. The nasal bone was either absent or hypoplastic in 12 of 29 (41%) fetuses with aneuploidy and in 8 of 18 (44%) with trisomy 21. By using receiver operating characteristics curves, the optimal threshold of nasal bone hypoplasia associated with fetal aneuploidy was a biparietal diameter/nasal bone ratio of 11 or greater. The sensitivity, specificity, and positive and negative predictive values for the detection of fetal aneuploidy were 50%, 93%, 24%, and 98%, respectively. CONCLUSION: Absent or hypoplastic nasal bone is a marker for fetal aneuploidy in a high-risk population. However, this marker needs to be evaluated by larger prospective studies in low-risk populations before adoption for clinical use.     

Obliteration of a tentorial dural arteriovenous fistula causing spinal cord myelopathy using the cranio-orbito zygomatic approach

BACKGROUND: Intracranial dural arteriovenous fistulas account for 10 to 15% of all intracranial arteriovenous malformations. Tentorial dural arteriovenous fistulas with spinal medullary venous drainage causing spinal cord myelopathy are very rare, but have been previously described. We describe a case using a cranio-orbito zygomatic approach with intraoperative angiography for the surgical treatment of a tentorial artery dural arteriovenous fistula causing spinal cord myelopathy. CASE PRESENTATION: A 42-year-old male presented complaining of a 1-year history of incoordination and dizziness and a 2-month history of progressive myelopathy with bowel and bladder incontinence. The patient had magnetic resonance imaging (MRI) performed along with cerebral and spinal angiography that revealed a right tentorial artery dural arteriovenous fistula with spinal medullary venous involvement down to T11. Angiographic embolization was attempted, but selective catheterization was unsuccessful. The patient underwent a cranio-orbito zygomatic approach with obliteration of the dural arteriovenous fistula. An intraoperative angiogram confirmed complete obliteration of the dural arteriovenous fistula. CONCLUSION: Intracranial dural arteriovenous fistulas are a rare cause of spinal cord myelopathy. When a patient presents with suspicion of spinal dural fistula and negative spinal angiography, an intracranial origin should be suspected and a cerebral angiogram performed. Skull base approaches along with intraoperative angiography provide an alternative modality for obliteration of the dural arteriovenous fistula nidus, thereby eliminating the venous congestion and hence the spinal cord ischemia.     

Limb sparing surgery for pediatric musculoskeletal tumors

There has been an unprecedented improvement in the survival outcome of children with extremity sarcoma as well as a corresponding increase in percentage of limb-sparing surgeries being performed over the past many decades. This has been, in part, due to the improved imaging modalities, newer surgical techniques, and advences in neoadjuvant chemotherapy. Limb-sparing surgery for primary bone and soft-tissue malignancies in children is becoming an acceptable option of surgical treatment in most cases today. This article outlines the demographics, classification, clinical presentation, imaging, and molecular genetics of pediatric mosculoskeletal tumors and discusses the current treatment principles with emphasis on the state-of-the-art surgical management and limb-sparing techniques for children with extremity sarcoma.     

Alpha 1A-adrenergic receptor polymorphism and vascular response

OBJECTIVE: The alpha(1A)-adrenergic receptor is highly expressed in human vasculature including resistance arteries and veins, and its stimulation is primarily responsible for adrenergically mediated smooth muscle contraction. Variability in sensitivity to phenylephrine, an alpha(1A) adrenergic agonist, has a large genetic component. We examined the hypothesis that a common polymorphism of alpha(1A)-adrenergic receptor (Arg347Cys) affects in vivo response. METHODS: We measured vascular sensitivity to phenylephrine using the dorsal hand vein linear variable differential transformer technique and determined alpha(1A)-adrenergic receptor genotype in 74 healthy, nonsmoking adults (28 Arg/Arg, 30 Arg/Cys, and 16 Cys/Cys). RESULTS: Sensitivity to phenylephrine, expressed as the dose of phenylephrine resulting in 50% venoconstriction (Phe(50)), was not significantly different in subjects with the 3 alpha(1A) adrenergic receptor genotypes: Phe(50) geometric mean (95% confidence interval) was 513 ng/min (287-918 ng/min) for Arg/Arg, 431 ng/min (274-680 ng/min) for Arg/Cys, and 471 ng/min (197-1124 ng/min) for Cys/Cys (P =.90). CONCLUSION: We conclude that the Arg347Cys receptor polymorphism does not alter agonist-mediated venoconstriction in vivo.     

Enhancement of paclitaxel-induced microtubule stabilization, mitotic arrest, and apoptosis by the microtubule-targeting agent EM012

EM012, a semisynthetic phthalideisoquinoline alkaloid, has been recently found to target microtubules and possess anti-cancer activity. In this study, we evaluated the effects of EM012 in combination with the classic microtubule-targeting agent paclitaxel. Our results demonstrated that EM012 enhanced the anti-proliferative activity of nanomolar concentrations of paclitaxel in human breast cancer (MCF7), prostate cancer (DU145), and non-small-cell lung cancer (A549) cells. Further studies revealed that EM012 increased the ability of nanomolar concentrations of paclitaxel to induce mitotic arrest and apoptosis, without affecting microtubule polymerization. In contrast, when micromolar concentrations of paclitaxel were used, EM012 promoted paclitaxel-induced microtubule polymerization both in vitro and in cultured cells. Nevertheless, EM012 enhanced the ability of nanomolar concentrations of paclitaxel to stabilize microtubules, as indicated by increased tubulin acetylation. Our results therefore suggest a therapeutic potential of EM012/paclitaxel combination in the management of human cancer and provide mechanistic insights into the combined effects of these two microtubule-targeting agents.     

Magnitude and impact of treatment delays on weeknights and weekends in patients undergoing primary angioplasty for acute myocardial infarction (the cadillac trial)

In 2,082 patients in the CADILLAC trial, the outcomes of patients presenting during peak hours were compared with those presenting during peak hours (Monday to Friday 8a.m. to 8 p.m., n = 1,047, 51%) were compared with those of patients presenting during off-peak hours (weeknights from 8 p.m. to 8 a.m. and weekends, n = 989, 49%). Although treatment times to percutaneous coronary intervention (PCI) were delayed approximately 21 minutes, in patients with acute myocardial infarctions occurring on weeknights and weekends, this modest delay did not adversely affect procedural success, myocardial recovery, or survival after PCI.     

Cyclin-dependent kinase 5 increases perikaryal neurofilament phosphorylation and inhibits neurofilament axonal transport in response to oxidative stress

Cyclin-dependent kinase 5 (cdk5) phosphorylates the high molecular weight neurofilament (NF) protein. Overexpression of cdk5 inhibits NF axonal transport and induces perikaryal accumulation of disordered phospho-NF cables. Experimental and clinical motor neuron disease is characterized by oxidative stress, increased cdk5 activity, and accumulation of phospho-NFs within perikarya or proximal axons. Because oxidative stress increases cdk5 activity in experimental motor neuron disease, we examined whether oxidative stress induced cdk5-mediated NF phosphorylation. Treatment of cultured neuronal cells with hydrogen peroxide inhibited axonal transport of green fluorescent protein-tagged NF subunits and induced perikaryal accumulation of NF phosphoepitopes normally confined to axons. These effects were prevented by treatment with the cdk5 inhibitor roscovitine or transfection with a construct expressing the endogenous cdk5 inhibitor peptide. These findings indicate that oxidative stress can compromise NF dynamics via hyperactivation of cdk5 and suggest that antioxidants may alleviate multiple aspects of neuropathology in motor neuron disease.     

Effects of cadmium(II) on (+/-)-anti-benzo[a]pyrene-7,8-diol-9,10-epoxide-induced DNA damage response in human fibroblasts and DNA repair: a possible mechanism of cadmium's cogenotoxicity

Cadmium, a widespread environmental pollutant and a cigarette smoke constituent, enhances the genotoxicity of benzo[a]pyrene (BP). The mechanism(s) underlying the potentiation of BP-induced genotoxicity by Cd2+ is not clearly understood. Our studies of the effects of noncytotoxic concentrations of Cd2+ on the levels of p53 and p21 in (+/-)-anti-benzo[a]pyrene-7,8-diol-9,10-epoxide (BPDE)-treated human fibroblasts showed that Cd2+ decreased BPDE-induced p21 levels in a dose-dependent manner whereas p53 accumulation is attenuated only at higher noncytotoxic concentrations of cadmium. These findings suggest that both the activity and the accumulation of p53 in response of BPDE treatment are inhibited by Cd2+ although the possibility of p53-independent p21 transactivation cannot be ruled out. Exposure of synchronized human fibroblast cells to 0.5 microM of BPDE caused 72% of the cells remaining in G1 phase as compared to 52% in the case of untreated cells. Treatment of the cells with CdCl2 prior to exposing them to BPDE caused a decrease in the G1 population (72 to 54%) in a dose-dependent manner. An in vitro repair assay of BPDE-damaged pUC18 plasmid DNA using untreated and cadmium-treated nucleotide excision repair (NER) proficient HeLa extract showed that cadmium impaired the ability of HeLa cell extract to repair BPDE-damaged pUC18 DNA. Our findings indicate that cadmium not only inhibits NER pathway-dependent repair of BPDE-damaged DNA but also impairs p53 and p21 responses and overrides BPDE-induced G1-S cell cycle arrest. The effect of cadmium on these processes may explain, at least partly, the potentiating effect of the metal on the genotoxicity of BP.     

Effect of oestrogen replacement therapy on serum lipid profile

BACKGROUND: Oestrogen deficiency in postmenopausal women alters the lipid metabolism unfavourably. AIM: To evaluate the effects of oral and transdermal oestrogen replacement therapy (ORT) on serum lipid profile. METHODS: Ninety hysterectomised and oophorectomised women were randomised into three equal groups (no hormones; oral conjugated equine oestrogen, 0.625 mg/day; transdermal oestradiol patches, 50 microg/day). Serum concentrations of total cholesterol, high-density lipoprotein (HDL) cholesterol, low-density lipoprotein (LDL) cholesterol and triglycerides were determined at the baseline and after 3 and 6 months of therapy. Student's t-test was used for statistical evaluation. RESULTS: Most of the hysterectomised women had abnormal serum lipid profile, especially HDL cholesterol levels (less than 40 mg/dL in 87%). A significant decline in the levels of serum cholesterol (total) as well as LDL and a significant increase in HDL cholesterol levels were observed following ORT by both modes, the response being comparatively rapid with oral route. After 3 and 6 months, the number of cases with HDL cholesterol levels above 40 mg/dL increased from initial 13 to 63% and 87% (oral) and 30 and 60% (transdermal), respectively. Serum triglyceride levels declined significantly with transdermal therapy but increased with oral ORT. CONCLUSIONS: Oestrogen replacement therapy either via oral or transdermal route has a beneficial effect on serum lipid profile of menopausal women. Whereas the oral route is more effective in increasing HDL cholesterol levels, the transdermal route is better for reducing the serum triglyceride level; hence, the latter should be the route of choice in women with high serum triglyceride levels.