Elucidation of signaling properties of vasopressin receptor-related receptor 1 by using the chimeric receptor approach

The identification of endogenous or surrogate ligands for orphan G protein-coupled receptors (GPCRs) represents one of the most important tasks in GPCR biology and pharmacology. The challenge lies in choosing an appropriate assay in the absence of ways to activate the receptor of interest. We investigated the signaling pathway for an orphan GPCR referred to here as vasopressin receptor-related receptor 1 (VRR1) by generating a chimeric receptor, V1a/VRR1. The engineered construct contained vasopressin V1a receptor with all three intracellular loops and C terminus replaced by those of VRR1. The chimera behaved like a typical GPCR when transiently and stably expressed in mammalian cell lines based on radioligand binding and receptor internalization studies. Upon arginine vasopressin stimulation, this chimeric receptor induced robust calcium mobilization and increase of adenylate cyclase activity. The observed signaling activities are through the activation of the chimera instead of endogenously expressed receptors, as single amino acid changes in the second transmembrane regions of the chimera drastically reduced receptor efficacy and potency. Our results suggest that VRR1 has dual signaling properties in coupling to both G(q) and G(S) pathways. Analysis of native VRR1 receptor signaling pathway by using a recently identified ligand for VRR1 confirmed this conclusion and therefore validated the utility of the chimeric receptor approach for signaling pathway identification.     

Hepatosplenic T Cell Lymphoma

A 26 year old lady came with intermittent fever since eight months. She also complained of abdominal pain and decreased appetite for six months. She had swelling of feet and distension of abdomen due to ascites since one month. There was history of jaundice one month back. On radiological examination, hepatomegaly with dilated portal vein, massive splenomegaly and ascites without any lymphadenopathy was noted. Chest X-ray was normal. Blood examination and bone marrow studies were inconclusive. We received her liver biopsy, which showed normal architecture and sinusoidal infiltration by a monomorphic population of small to intermediate sized lymphoid cells. Portal tracts were free of such infiltrate. These lymphoid cells were LCA, CD3, CD43 positive and negative for CD20, CD34, CD4, CD8 and c-kit. Based on all these features, a diagnosis of Hepatosplenic T cell lymphoma was made. She was treated symptomatically, however she died within two months of diagnosis.     

Clinical significance of serum and cerebro spinal fluid bilirubin indices in neonatal jaundice

To assess the value of unbound bilirubin (UB) and saturation index (SI) in serum and CSF as indicators of Kernicterus, we studied 50 icteric neonates (serum indirect bilibrubin (IB) greater than or equal to 7 mg/dl) and 20 controls (IB less than 7 mg/dl) during the first week of life. Serum and CSF were obtained simultaneously in all neonates. Of 36 neonates with IB greater than 12 mg/dl 19 had evidence of kernicterus. UB was estimated by Sephadex gel filtration and SI by salicylate displacement technique. Positive correlation (r = +0.85) was obtained between serum and CSF UB levels. There was a significant difference (p less than 0.05) between mean serum and CSF UB levels in kernicterus and non-kernicterus neonates (kernicterus serum UB = 0.71 +/- 0.22) mg/dl, CSF UB = 0.16 +/- 0.06 mg/dl: non-kernicteric serum UB = 0.40 +/- 0.10 mg/dl, CSF UB = 0.10 +/- 0.03 mg/dl). A critical serum UB level 0.5 mg/dl and a danger zone of CSF UB (0.1 to 0.15 mg/dl) was observed in presence of kernicterus. Neonates with kernicterus and 30% non-kernicteric had serum SI greater than or equal to 8. Mean values of serum and CSF SI were comparable in all neonates. The serum and CSF UB and SI, and the mean percentage cross over of UB from serum to CSF when statistically compared were not significantly influenced by risk factors.     

Ranibizumab as an adjunct to laser for macular edema secondary to branch retinal vein occlusion

Purpose:

To compare the safety, efficacy, and dosing regimen of intravitreal ranibizumab as an adjunct to laser therapy for the treatment of macular edema secondary to branch retinal vein occlusion (BRVO).

Materials and Methods:

Thirty eyes of 30 patients of BRVO of at least 6 weeks duration were randomized into three groups: Group 1 received grid laser treatment alone, Group 2 received a single dose of intravitreal injection of ranibizumab (0.5 mg / 0.05 ml) followed by grid laser treatment on 7^th day following injection, while Group 3 received three loading doses of intravitreal ranibizumab at monthly interval (i.e. 0, 1, & 2 months) + standard laser treatment 7 days after the 1^st injection. Outcome measure noted at 6 months follow-up were the improvement in best-corrected visual acuity (BCVA) and central macular thickness (CMT).

Results:

At 6 months follow-up, there was an average gain of 12 letters (P=0.05), 17.5 letters (P=0.05) and 19 letters (P=0.05) in groups 1, 2, and 3, respectively, with the decrease in CMT being 208.7 μm (P=0.05), 312.9 μm (P= 0.05) and 326.8 μm (P=0.05), respectively, in these groups. Gain in BCVA of more than 3 lines was noted in 1/10 patients in Group 1(10%) as compared to 3/10 (30%) and 4/10 (40%) patients in groups 2 and 3, respectively.

Conclusion:

The gain in BCVA and reduction in CMT were better with combination therapy (single- and triple- dose regimen) compared to grid laser alone. Single dose of intravitreal ranibizumab with grid laser seems to be an effective therapy.     

Blood Transfusion Practice in Obstetric and Gynecology: Impact of Educational Programs to Create Awareness for Judicious Use of Blood Components

The study presents the data analysis (1) To find out the trend of blood component use during the period 2003–2010 and to determine impact of component awareness programs on reduction in whole blood (WB) and single unit transfusions. (2) To determine Hb trigger. The details about blood units issued were entered in the integrated blood bank management software as well as in Microsoft Excel. The data of 4,838 cases of pregnancy anemia; 2,244 receiving blood for obstetric (Ob) hemorrhage including 270 cases of disseminated intravascular coagulation; 1,413 women having Gynecological (Gy) bleeding; 911 Ob, 2,032 Gy and 740 surgeries for Gy malignancy were analyzed. During the years 2003–2010 there was gradual increase in component utilization for pregnancy anemia, Ob/Gy surgeries and Ob/Gy bleeding and significant reduction in WB transfusions due to component awareness programs. But single unit transfusions showed comparatively lower trend of reduction. The mean Hb was 6.4 g/dL for pregnancy anemia, 8.1 g/dL for surgeries and 7.3 g/dL for Ob/Gy bleeding.