Clinical Research and Development

Stroke is the second leading cause of death and permanent disability in adults worldwide. The treatment options for ischemic are very limited and new therapies are still required. Arginase is an endogenous competitor of Nitric acid Synthase (NOS) for the common substrate L-arginine, and upregulation of arginase during Ischemia/Reperfusion (I/R) compromises NO mediated effects. In this work, we focused on the inflammatory response to brain ischemia and the potential role of L-norvaline as arginase inhibitor against ischemic brain injury.  

       Rats were subjected to Middle Cerebral Artery Occlusion (MCAO) and the effects of L-Norvaline (50 mg/kg/day) on infarct volume, serum Advanced Glycation End products (AGEs), behaviour (gait score and ability to grasp), expression of Arginase (I & II), iNOS, eNOS, TNF-α and IL-1β level was compared to the standard Cerebrolysin (0.15 mg/kg, ip).  
     

The results of the current study support the involvement of inflammation in ischemic brain injury and point out a possible role of arginase in this process. 

Doxorubicin (DOX) is a potent anticancer drug whose application is hampered by its cardiotoxicity mediated by oxidative stress and inflammation.  Glycyrrhizic acid (glycyrrhizin) is a natural compound that exerts anti-inflammatory and anti-oxidant action. The present study aimed to examine whether the administration of glycyrrhizic acid can produce protective effect against acute DOX cardiotoxicity. Cardiotoxicity was induced in rats by intraperitoneal injection of DOX (15 mg/kg). Results revealed that DOX administration exhibited elevated serum level Lactate Dehydrogenase (LDH) myocardial TNF-α content, in addition to reduced myocardial Catalase (CAT) activity. Pretreatment with glycyrrhizic acid (100 mg/kg, orally) for nine days markedly ameliorated all these changes and substantially reduced the myocardium peroxidative damage. The protective effects obtained by glycyrrhizic acid may be via its antioxidant and anti-inflammatory properties and suggest its possible use to prevent or reduce doxorubicin-induced cardiotoxicity 

Objectives: Diabetes can affect bone via obesity, hyperglycemia, hyperinsulinemia, and hypoinsulinemia. Osteocalcin (OC) is a non-collagenous protein of the bone that contributes to bone formation. A population-based study was done to examine the relationship between the serum level of under carboxylated osteocalcin (ucOC) and diabetes.  

Methods: A cross-sectional study was done in 2,062 women aged 40 to 69 years living in a suburban Japanese town. Serum ucOC level by electro chemiluminescent immunoassay, Fasting Plasma Glucose (FPG), and glycohemoglobin A1c (HbA1c) were measured for each participant. Participants who were previously diagnosed with diabetes or who were receiving its treatment were defined as having pre-existing diabetes. Participants without pre-existing diabetes who had a FPG level >7.0 mmol/L or HbA1c level of ≥6.5 % were defined as having newly diagnosed diabetes.  

Results: The median serum ucOC level of 1,433 postmenopausal women (5.2 ng/mL) was significantly higher than that of 629 premenopausal women (3.1 ng/mL) (P<0.0001). The distribution of postmenopausal women   with pre-existing diabetes, newly diagnosed diabetes, and non-diabetes was 38 (2.7%), 88 (6.1%), and 1,307 (91.2%), respectively. The median serum ucOC levels of the 3 groups of postmenopausal women significantly decreased with worsened glucose metabolism (pre-existing diabetes 3.38, newly diagnosed diabetes 4.51, and non-diabetes 5.51 ng/mL) (P<0.0001). Multivariate regression analysis showed the FPG and HbA1c values to be negative factors independently associated with the serum ucOC level of postmenopausal women.  

Conclusions: These findings indicate that the serum ucOC levels decrease in postmenopausal diabetic women, suggesting a relationship between diabetes and 
osteoporosis.  

DNA recombinases are used to manipulate the genomic structure and to control the genetic expression in all living organisms. Cre is a P1 bacteriophage-derived tyrosine recombinase mediating the site-specific recombination between two loxP DNA recognition sites. Cre/loxP system allows generation of tissue specific mutations and is widely used in bioengineering and in mouse genetics. However, various factors limit its applicability such as lack of temporal control over its recombination activity, presence of cellular compensatory mechanisms, loss of site-specificity at high expression levels and its limited use for conditional recombination in certain brain structures due to a lack of sufficiently selective promoters. One approach used to overcome these drawbacks is the so-called split-iCRE technique that employs complementation of split-iCRE fragments via artificial FKBP12-rapamycin or ɑ-helix interactions. Rapamycin is a pharmacologically active substance while leucine zipper-mediated complementation so far only insufficiently restores recombinase activity. Here we introduce a system for controlling ɑ-complementation of two independent iCRE fragments under the control of  two different promoters to reconstitute recombinase activity. Unsplit-iCRE was split between Lys130 and  Asp132. Fragments were complemented restoring ~ 95% of the recombinase activity with very little background activity. Adding an external nuclear localization signal to the C-terminal fragment resulted in even higher enzymatic activity. Using an extended rigid linker between the polypeptide and the yeast GCN4-coil/coil leucine zipper domains was more efficient than a semi-flexible separator. The system was validated by knocking out the essential circadian clock component Bmal1 (Arntl) in MEF cells resulting in a loss of clock function in MEF cells.

Introduction Intravascular large B-cell lymphoma is a rare subtype of diffuse large B-cell lymphoma with an estimated frequency of less than one percent of all lymphomas. It has a variety of presentations and is known as “the great imitator” as it may mimic other conditions. It has a fulminant course with high mortality if left untreated.  

Case Presentation Discussion 
We report a 65-year-old male who presented with exertional dyspnea, dry cough, and hoarseness of a few days. Work-up did not reveal any specific condition or lesion in the cardiopulmonary systems. He developed worsening pancytopenia within one week, underwent a bone marrow biopsy, and was found to have intravascular diffuse large B cell lymphoma with hypertetraploidy (karyotype XXYY). His symptoms improved after one cycle of chemotherapy. Bone marrow biopsy after six cycles of chemotherapy showed no evidence of lymphoma and a normal karyotype. Intravascular large B-cell lymphoma is a type of extranodal large B-cell lymphoma where growth is restricted to the Lumina of vessels. It is a rapidly fatal malignancy when diagnosis and treatment is delayed. There are two forms: the Western form presents with skin, neurologic findings and lymphadenopathy, and the Asian form presents with fever, anemia, thrombocytopenia, hepatosplenomegaly, 
bone marrow invasion, respiratory disturbance and disseminated intravascular coagulopathy. Our patient presents as a hybrid of both variants despite being of 
Western origin.