Prenatal express-diagnosis by the method of QF-PCR and automatic microelectroforesis with microarrays

The modern molecular-genetic methods have been implementing actively into the medical practiee.They improve diagnostic accuracy,help to prognosticate the course of oncological diseases,optimize the res...     

Metabotropic glutamate receptor 5 positive allosteric modulators are neuroprotective in a mouse model of Huntington's disease

Background and Purpose

Huntington''s disease (HD) is an autosomal dominant neurodegenerative disorder caused by a polyglutamine expansion in the huntingtin protein. We have previously demonstrated that the cell signalling of the metabotropic glutamate receptor 5 (mGluR5) is altered in a mouse model of HD. Although mGluR5-dependent protective pathways are more activated in HD neurons, intracellular Ca²⁺ release is also more pronounced, which could contribute to excitotoxicity. In the present study, we aim to investigate whether mGluR5 positive allosteric modulators (PAMs) could activate protective pathways without triggering high levels of Ca²⁺ release and be neuroprotective in HD.

Experimental Approach

We performed a neuronal cell death assay to determine which drugs are neuroprotective, Western blot and Ca²⁺ release experiments to investigate the molecular mechanisms involved in this neuroprotection, and object recognition task to determine whether the tested drugs could ameliorate HD memory deficit.

Key Results

We find that mGluR5 PAMs can protect striatal neurons from the excitotoxic neuronal cell death promoted by elevated concentrations of glutamate and NMDA. mGluR5 PAMs are capable of activating Akt without triggering increased intracellular Ca²⁺ concentration ([Ca²⁺]_i); and Akt blockage leads to loss of PAM-mediated neuroprotection. Importantly, PAMs'' potential as drugs that may be used to treat neurodegenerative diseases is highlighted by the neuroprotection exerted by mGluR5 PAMs on striatal neurons from a mouse model of HD, BACHD. Moreover, mGluR5 PAMs can activate neuroprotective pathways more robustly in BACHD mice and ameliorate HD memory deficit.

Conclusions and Implications

mGluR5 PAMs are potential drugs that may be used to treat neurodegenerative diseases, especially HD.     

Anti-inflammatory effects of tobramycin and a copper–tobramycin complex with superoxide dismutase-like activity

Background and Purpose

Airway inflammation in cystic fibrosis (CF) patients is characterized by accumulations of neutrophils in the airway and T cells in bronchial tissue, with activation of platelets in the circulation. CF patients are routinely treated with systemic or inhaled tobramycin for airway infection with Pseudomonas aeruginosa. Clinical trials have indicated an anti-inflammatory effect of tobramycin beyond its bactericidal activity. Here, we investigate the anti-inflammatory properties of tobramycin in vitro and consider if these relate to the ability of tobramycin to bind copper, which is elevated in blood and sputum in CF.

Experimental Approach

A copper–tobramycin complex was synthesized. The effect of tobramycin and copper–tobramycin on neutrophil activation and migration of T cells and neutrophils across human lung microvascular endothelial cells in response to thrombin-activated platelets were investigated in vitro. Tobramycin uptake was detected by immunocytochemistry. Intracellular reactive oxygen species were detected using the fluorescent indicator, 2′,7′-dichlorofluorescein diacetate (DCFDA). Neutrophil superoxide, hydrogen peroxide and neutrophil elastase activity were measured using specific substrates. Copper was measured using atomic absorption spectroscopy.

Key Results

Tobramycin and copper–tobramycin were taken up by endothelial cells via a heparan sulphate-dependent mechanism and significantly inhibited T-cell and neutrophil transendothelial migration respectively. Copper–tobramycin has intracellular and extracellular superoxide dismutase-like activity. Neutrophil elastase inhibition by α1-antitrypsin is enhanced in the presence of copper–tobramycin. Tobramycin and copper–tobramycin are equally effective anti-pseudomonal antibiotics.

Conclusions and Implications

Anti-inflammatory effects of tobramycin in vivo may relate to the spontaneous formation of a copper–tobramycin complex, implying that copper–tobramycin may be more effective therapy.     

Perioperative myocardial ischemic episodes are related to hematocrit level in patients undergoing radical prostatectomy

BACKGROUND: The anemia associated with perioperative blood conservation has raised concerns regarding the safety of these strategies in patients with ischemic cardiovascular disease. Therefore the relationship between hematocrit level and myocardial ischemic episodes in a group of elderly patients undergoing elective noncardiac surgery was studied. STUDY DESIGN AND METHODS: One hundred ninety patients undergoing radical prostatectomy were randomly assigned to one of three blood conservation groups: preoperative autologous blood donation, acute normovolemic hemodilution, and preoperative erythropoietin therapy with acute normovolemic hemodilution. Patients underwent ambulatory electrocardiography monitoring to evaluate for myocardial ischemia at randomization (baseline), 7 days preoperatively, throughout surgery, and for 24 hours after surgery. RESULTS: Myocardial ischemic episodes occurred in 61 (34%) of 181 evaluable patients. Patients with hematocrit levels < 28 percent immediately after surgery were significantly (p = 0.05) more likely to have intraoperative and postoperative ECG ischemic episodes. Intraoperative ischemia and tachycardia correlated (r = 0.21, p = 0.008) with hematocrit levels. Hematocrit levels after surgery were associated with postoperative ischemia (r = 0.14, p = 0.03) and duration of myocardial ischemic episodes (r = 0.14, p = 0.04). After adjusting for other risk factors, intraoperative tachycardia episodes, hematocrit level < 28 percent immediately after surgery, and risk factors for coronary artery disease were independently associated with the likelihood of intraoperative ischemia (r = 0.36, p = 0.002, area under receiver operating characteristic curve = 0.73). Similarly, tachycardia episodes and hematocrit levels < 28 percent immediately after surgery were independently associated with ischemic episodes during the first postoperative day (r = 0.30, p = 0.004, area under receiver operating characteristic curve = 0.71). CONCLUSION: A hematocrit level < 28 percent is independently associated with risk for myocardial ischemia during and after noncardiac surgery. Avoidance of cardiac complications may require higher transfusion thresholds, closer attention to tachycardia, or better monitoring for ischemia.     

Decreased nucleotide and serotonin storage associated with defective function in Chediak-Higashi syndrome cattle and human platelets

Prolonged mean template bleeding time of 14 min observed in seven cattle with the Chediak-Higashi syndrome (CHS) prompted the examination of platelet function in these animals. There was no distinguishable difference in concentration of circulating platelets between CHS and control cattle. CHS bovine platelets failed to aggregate in vitro in response to concentrations of acid-soluble collagen which induced aggregation in all normal samples. The primary platelet response to 5 muM ADP was normal in CHS cattle. A markedly decreased amount of serotonin (1.2% of normal) was detected in CHS bovine platelets. Bovine CHS platelet ATP and ADP contents were significantly less than normal, and the ATP/ADP ratios were 5.04 in normal and 29.38 in CHS platelets. Results of these animal investigations prompted a similar study of two patients with CHS. In humans, an increased bleeding time greater than 15 min and an in vitro impaired aggregation response to acid-soluble collagen and 5 muM adrenaline were discovered. Both ATP and ADP were reduced in CHS human platelets, and the ATP/ADP ratio was 3.96, compared to a ratio of 1.52 for platelets of two normal subjects. These findings suggested the presence of a "storage pool disease" of CHS platelets.