Identification of a novel small-molecule inhibitor of the hypoxia-inducible factor 1 pathway

Hypoxia-inducible factor 1 (HIF-1) is the central mediator of cellular responses to low oxygen and has recently become an important therapeutic target for solid tumor therapy. Inhibition of HIF-1 is expected to result in the attenuation of hypoxia-inducible genes, which are vital to many aspects of tumor biology, including adaptative responses for survival under anaerobic conditions. To identify small molecules inhibiting the HIF-1 pathway, we did a biological screen on a 10,000-membered natural product-like combinatorial library. The compounds of the library, which share a 2,2-dimethylbenzopyran structural motif, were tested for their ability to inhibit the hypoxic activation of an alkaline phosphatase reporter gene under the control of hypoxia-responsive elements in human glioma cells. This effort led to the discovery of 103D5R, a novel small-molecule inhibitor of HIF-1alpha. 103D5R markedly decreased HIF-1alpha protein levels induced by hypoxia or cobaltous ions in a dose- and time-dependent manner, whereas minimally affecting global cellular protein expression levels, including that of control proteins such as HIF-1beta, IkappaBalpha, and beta-actin. The inhibitory activity of 103D5R against HIF-1alpha was clearly shown under normoxia and hypoxia in cells derived from different cancer types, including glioma, prostate, and breast cancers. This inhibition prevented the activation of HIF-1 target genes under hypoxia such as vascular endothelial growth factor (VEGF) and glucose transporter-1 (Glut-1). Investigations into the molecular mechanism showed that 103D5R strongly reduced HIF-1alpha protein synthesis, whereas HIF-1alpha mRNA levels and HIF-1alpha degradation were not affected. 103D5R inhibited the phosphorylation of Akt, Erk1/2, and stress-activated protein kinase/c-jun-NH(2)-kinase, without changing the total levels of these proteins. Further studies on the mechanism of action of 103D5R will likely provide new insights into its validity/applicability for the pharmacologic targeting of HIF-1alpha for therapeutic purposes.     

Detection and identification of mouse mammary tumor virus-like DNA sequences in blood and breast tissues of breast cancer patients

Mouse mammary tumor virus (MMTV) is a well-known cause of mammary tumors in mice transmitted as endogenous proviruses or exogenously as infectious virions. The hypothesis that a retrovirus homologous to MMTV is involved in human breast cancers has resulted in renewed interest in the etiology of human breast cancer. Therefore, the detection of MMTV-like exogenous sequences in 30–40 % of invasive breast cancer has increased attention towards this hypothesis. To detect the prevalence of MMTV in Pakistani population, 666-bp-long MMTV envelop and 630-bp LTR sequences were amplified from breast cancer patient samples (tissue biopsies and peripheral blood) using mouse with mammary tumor as control. MMTV-like virus env and LTR DNA sequences were detected in 20 and 26 % of breast tumor samples, respectively, from the total of 80 breast cancer patients’ blood and tissue samples. No significant association was observed between age, grade of disease, and lymph node involvement with the prevalence of MMTV-like sequences. Our data add to the growing number of studies implicating MMTV-like virus in human breast cancer, but still clear causal association of MMTV to breast cancer remains to be reputable.     

Risk factors and impact of major bleeding in critically ill patients receiving heparin thromboprophylaxis

Purpose

Bleeding frequently complicates critical illness and may have serious consequences. Our objectives are to describe the predictors of major bleeding and the association between bleeding and mortality in medical–surgical critically ill patients receiving heparin thromboprophylaxis.

Methods

We prospectively studied patients from 67 intensive care units and six countries enrolled in a thromboprophylaxis trial (NCT00182143) comparing dalteparin with unfractionated heparin. Patients with trauma, orthopedic surgery or neurosurgery were excluded. Trained research coordinators used a validated tool to document bleeding, which underwent duplicate independent blinded adjudication. Major bleeding was defined as hypovolemic shock, bleeding into critical sites, requiring an invasive intervention or transfusion of at least two units of red blood cells, or associated with hypotension or tachycardia in the absence of other causes. Adjusted Cox proportional hazard regression analysis was used to identify major bleeding predictors and the association between bleeding and mortality.

Results

Among 3,746 patients, bleeding occurred in 208 [5.6 %, 95 % confidence interval (CI) 4.9–6.3 %]. Time-dependent predictors were prolonged activated partial thromboplastin time [hazard ratio (HR) 1.10, 1.05–1.14 per 10 s increase], lower platelet count (HR 1.16, 1.09–1.24 per 50 × 10⁹/L decrease), therapeutic heparin (HR 3.26, 1.72–6.17), antiplatelet agents (HR 1.38, 1.02–1.88), renal replacement therapy (HR 1.75, 1.20–2.56), and recent surgery (HR 1.64, 1.01–2.65). Type of pharmacologic thromboprophylaxis was not associated with bleeding. Patients with bleeding had a higher risk of in-hospital death (HR 2.09, 1.69–2.57).

Conclusions

As major bleeding has modifiable risk factors and is associated with in-hospital mortality, strategies to mitigate these factors should be evaluated in critically ill patients.     

Restless leg syndrome, periodic limb movements, febrile seizures and Attention deficit hyperactivity disorder in an Indian family

Restless leg syndrome (RLS) is a common neurological disorder which can affect individuals of all age groups and incidence increasing with age. It can cause severe sleep disruption and negatively impact quality of life of an individual. Its diagnosis is clinical, based on essential criteria of International RLS Study Group. It can be idiopathic or associated with various medical and other neurological disorders. Idiopathic RLS can be sporadic or may have a familial inheritance, with several genetic loci been reported till date. RLS has a strong association with periodic limb movements, both sleep and awake. Very few studies of familial RLS/Periodic limb movements in sleep and their associations have been reported. We report an Indian family with autosomal dominant RLS/PLMS, with RLS and PLMS as well as psychiatric disorders, febrile seizures and Attention Deficit Hyperactivity Disorder in different family members, over three generations.     

Stent placement for treatment of mesenteric artery stenoses or occlusions.

PURPOSE: To evaluate stent placement in the treatment of mesenteric ischemia. PATIENTS AND METHODS: Twelve patients (eight women, four men; mean age, 63 years) with chronic mesenteric ischemia underwent stent placement for stenoses or occlusions during a 5.5-year period. Nine patients with 10 stenoses (three celiac arteries, seven superior mesenteric arteries) and three patients with three chronic occlusions (two superior mesenteric arteries, one aortosuperior mesenteric artery bypass graft) were treated. RESULTS: Initial technical success was achieved in 11 of the 12 patients (92%), including all three patients with chronic occlusions. There were no technical complications. There was one postprocedural death (<30 days) due to bowel ischemia and infarction, despite a technically successful procedure. Clinical follow-up was available in all 12 patients, with a mean follow-up of 15.7 months (range, 0-38.5 months). Primary and primary-assisted patency up to 18 months was 74% (standard error [SE], 13%) and 83% (SE, 11%), respectively. Secondary patency was 83% (SE, 11%) at 3 years. All three patients (100%) with chronic occlusions had relief of clinical signs and symptoms at a mean follow-up of 22 months (range, 13-38.5 months). CONCLUSIONS: Stent placement is safe and clinically effective as an adjunctive therapy to angioplasty or as a primary method of treatment for chronic mesenteric ischemia in patients with focal visceral artery stenoses or occlusions.     

Pelvic pain in the middle of the night: use of MRI for evaluation of pediatric female pathology in the emergent setting

Acute pelvic pain in pediatric female patients is a common cause of emergency room visits. Imaging plays a crucial role in the clinical evaluation of these patients. Pelvic pain in female children can result from various pathologies. Ultrasound is the preferred first line imaging study; however, magnetic resonance imaging (MRI) is a helpful adjunct after hours, as it is available 24/7 in many institutions. Advantages of MRI include superior delineation of anatomy and higher tissue contrast resolution, particularly of the small pelvic structures. Given the lack of ionizing radiation, there is increasing use of MRI in children and adolescents, specifically in an emergent setting. In this pictorial review, we discuss pelvic MRI techniques and illustrate imaging findings of common etiologies of pelvic pain, emphasizing the advantages of MRI as an adjunct imaging modality.