Histamine H4 receptor: a novel therapeutic target for immune and allergic responses

HIstamine is a biomolecular compound located in various parts of body. It participated in various important cellular activities associated with allergy and asthma. This magic bio-molecule is directly and indirectly involved in various biochemical reactions through G-protein couple receptors. Various histamine receptors and their unexplored biochemical activities attracted many biologists in last few decades. A surprising discovery of histamine H(4) receptor was done when scientist worked on histamine H(3) receptor in brain cells. The binding pocket of histamine H(4) differs by transmembrane domains (TM3, TM5 and TM6) from histamine H(3)-sub type. In this review, we enlightened various functions of histamine H(4) and use of histamine H(4) receptor antagonists in autoimmune diseases, allergic responses, inflammatory responses, and in superoxide generation which are helpful to establish H(4) receptor antagonists as newer anti histamines.

A supercritical fluid chromatography/tandem mass spectrometry method for the simultaneous quantification of metformin and gliclazide in human plasma

Present study reports the development and validation of a simultaneous estimation of metformin and gliclazide in human plasma using supercritical fluid chromatography followed by tandem mass spectrometry. Acetonitrile:water (80:20) mixture was used as a mobile phase along with liquid CO₂ in supercritical fluid chromatography and phenformin as an internal standard. The modified plasma samples were analyzed by electro-spray ionization method in selective reaction monitoring mode in tandem mass spectrometry. Supercritical fluid chromatographic separation was performed using nucleosil C₁₈ containing column as a stationary phase. The separated products were identified by characteristic peaks and specific fragments peaks in tandem mass spectrometry as m/z 130 to 86 for metformin, m/z 324 to 110 for gliclazide and m/z 206 to 105 for phenformin. The present method was found linear in the concentration ranges of 6.0-3550 ng/ml and 7.5-7500 ng/ml for metformin and gliclazide, respectively. Pharmacokinetic study was performed after an oral administration of dispersible tablets containing 500 mg of metformin and 80 mg of gliclazide using same techniques.

Comparing effectiveness of high-dose Atorvastatin and Rosuvastatin among patients undergone Percutaneous Coronary Interventions: A non-concurrent cohort study in India

INTRODUCTION

Atorvastatin-80mg/day and Rosuvastatin-40mg/day are the commonest high-dose statin (3-hydroxy-3-methylglutaryl coenzyme-A reductase inhibitors) regimes for post-PCI (Percutaneous Coronary Interventions) patients to lower (by ≥50%) blood low-density-lipoprotein cholesterol (LDL-C). Dearth of conclusive evidence from developing world, regarding overall safety, tolerability and comparative effectiveness (outcome/safety/tolerability/endothelial inflammation control) of Rosuvastatin over Atorvastatin in high-dose, given its higher cost, called for an overall and comparative assessment among post-PCI patients in a tertiary cardiac-care hospital of Kolkata, India.

METHODS

A record-based non-concurrent cohort study was conducted involving 942 post-PCI patients, aged 18-75 years, on high-dose statin for three months and followed up for ≥one year. Those on Atorvastatin-80mg (n = 321) and Rosuvastatin-40mg (n = 621) were compared regarding outcome (death/non-fatal myocardial infarction: MI/repeated hospitalization/target-vessel revascularisation/control of LDL and high-sensitivity C-reactive protein: hsCRP), safety (transaminitis/myopathy/myalgia/myositis/rhabdomyolysis), tolerability (gastroesophageal reflux disease: GERD/gastritis) and inflammation control adjusting for socio-demographics, tobacco-use, medications and comorbidities using SAS-9.4.

RESULTS

Groups varied minimally regarding distribution of age/gender/tobacco-use/medication/comorbidity/baseline (pre-PCI) LDL and hs-CRP level. During one-year post-PCI follow up, none died. One acute MI and two target vessel revascularizations occurred per group. Repeated hospitalization for angina/stroke was 2.18% in Atorvastatin group vs. 2.90% in Rosuvastatin group. At three-months follow up, GERD/Gastritis (2.18% vs 4.83%), uncontrolled hs-CRP (22.74% vs 31.08%) and overall non-tolerability (4.67% vs. 8.21%) were lower for Atorvastatin group. Multiple logistic regression did show that compared to Atorvastatin-80mg, Rosuvastatin-40mg regime had poorer control of hs-CRP (A3OR = 1.45,p = 0.0202), higher (A3OR = 2.07) adverse effects, poorer safety profile (A3OR = 1.23), higher GERD/Gastritis (A3OR = 1.50) and poorer overall tolerability (A3OR = 1.50).

CONCLUSION

Post-PCI high dose statins were effective, safe and well-tolerated. High dose Rosuvastatin as compared to high dose Atorvastatin were similar in their clinical efficacy. Patients treated with Atrovastatin had significantly lower number of patients with hs-CRP (high-sensitivity C-reactive protein)/C-reactive protein (CRP) level beyond comparable safe limit and relatively better tolerated as opposed to Rosuvastatin-40mg.Thus given the lower price, Atorvastatin 80mg/day appeared to be more cost-effective. A head-to-head cost-effectiveness as well as efficacy trial may be the need of the hour.

Prevalence of Novel Risk Factors in Patients of Acute Coronary Syndrome in Eastern India: A Detailed Analysis

<p><strong>Background:</strong> To  identify  prevalence  of   the  novel  risk  factors  among  young  patients   with  Acute  Coronary  Syndrome  (ACS)  and  having  no  or  minimal  conventional  risk factors. <strong></strong></p><p><strong>Methods</strong>: Total  70  patients  ( male  48 ,  female 22 )   who  were  admitted  in  our  hospital with  ACS,  without  any  traditional  risk  factors  were  analyzed  for  hsCRP  [highly  sensitive  C  reactive  protein ],  Lp(a)  [Lipoprotein(a)],  Homocysteine  and  uric  acid  level.</p><p><strong>Results:</strong> 44.29%  of  the  study  population  have  high  values  of  hs-CRP,  more  in  older age  group  but  not  significant (&lt;40 vs &gt;40 yrs) (P=0.79). High  homocysteine  present in 42.86%  of cases,  more  in  older  age ( &gt;40 yrs) (54.55%)  than  &lt;40  years  age  (23.08%) which  is  statistically  significant  (P-0.01).  High  uric  acid  level  found  in  32.86%  of cases  without  any  significant  age  and  sex  difference.  High  Lp(a)  level  is  found  in 41.43%  of  cases  more  among ≥40  years (50%)  than  &lt;40 years (26.92%),  the  difference was  not  found  to  be  statistically  significant. [ Chi-square = 3.587; P=0.058; OR=2.71 95%  CI= 0.95 – 7.7].</p><p><strong>Conclusion:  </strong>hsCRP  is  most  useful  cost  effective  screening  method  for  ACS  in younger  individual  among  all  other  parameters  in  this  part  of  world .</p>

MicroRNA 155:145 ratio as a marker of atherogenic tilt manifested across different age groups and risk factor profiles

Funding Acknowledgements

Type of funding sources: None.

Background

 Differential expression of microRNAs is critical in the genesis and progression of atherosclerosis. MiR145 has atheroprotective role through improved homeostasis of smooth muscle cells (SMC). MiR155 is pro-atherogenic due to its suppression of Bcl6, which antagonises NF-κB and modulates macrophages.

Purpose

  Our purpose was to determine if the differential expression of miR 155 & 145 (expressed as miR 155:145 ratio) across various age groups and risk factor profiles correlates with atherosclerotic cardiovascular disease (ASCVD).

Materials and Methods

  This observational cross-sectional study was done between Feb"19 & Jan"20 on 108 patients divided equally into 3 age groups: &lt;18, 18-45 & &gt;45yrs. Family history (of ASCVD or risk factors) and risk factor profile were assessed in all 3 groups; and in the latter two, presence or absence of ASCVD was additionally evaluated by coronary angiogram and/or carotid IMT. MiR155 & 145 were measured in all by RT-PCR, & the results were then compared after calculating the ratio.

Results

 miR 155:145 ratio was significantly increased in &lt;18yrs aged subjects with a positive family history(p = 0.001). Multivariate regression analysis revealed a significant positive correlation of miR155:145 with family history of risk factors or ASCVD in this group(p &lt; 0.001).

In the 18-45yrs age group, the miR 155:145 ratio was found to be significantly increased in patients with diabetes(p = 0.037) and significant coronary artery disease(CAD) as determined by Syntax score(p &lt; 0.001). In multivariate regression analysis, a significant positive correlation was found between miR 155:145 and Syntax score(p &lt; 0.001) – a ratio of 155:145 &gt; 1 implied a greater chance of CAD, with increased numerical values correlating with increased severity of disease as evidenced by Syntax score; and a ratio &lt; 1 decreased the chances of significant CAD considerably. A positive association was also discovered for this ratio with hypertension, diabetes, tobacco exposure and a combination of multiple risk factors, but none of them were statistically significant.

In the age group of &gt;45 yrs, regression analysis revealed a statistically insignificant positive association of the miR 155:145 ratio with Syntax score, hypertension, dyslipidaemia and a combination of risk factors.

Conclusion

 MiR 155:145, when &gt;1, can point towards an ‘atherogenic tilt’, and greater increase in the ratio numerically may denote more severe disease, as indicated by a positive association with Syntax Score. This atherogenic tilt occurs very early in life, even before 18 years with significant family history. Above 18 years, with addition of other risk factors, this tilt is further compounded, and correlated well with Syntax score and such risk factors. Therefore, miR 155:145 ratio may help in identifying the individuals at risk for development of clinically significant CAD and can be utilised for development of future therapeutic strategies as well as prognostication. Abstract Figure 1  Abstract Figure 2

Fermi surface of the chiral topological semimetal PtGa

PtGa is a topological semimetal with giant spin-split Fermi arcs. Here, we report on angular-dependent de Haas-van Alphen (dHvA) measurements combined with band-structure calculations to elucidate the details of the bulk Fermi surface of PtGa. The strong spin-orbit coupling leads to eight bands crossing the Fermi energy that form a multitude of Fermi surfaces with closed extremal orbits and results in very rich dHvA spectra. The large number of experimentally observed dHvA frequencies make the assignment to the equally large number of calculated dHvA orbits challenging. Nevertheless, we find consistency between experiment and calculations verifying the topological character with maximal Chern number of the spin-split Fermi surface.