A Tribute to Professor Saranjit Singh - A Critical Thinker,Innovator, Mentor,and Educator

This commentary presents contributions and accomplishments of Professor Saranjit Singh, National Institute of Pharmaceutical Education and Research (NIPER), SAS Nagar, India, to pharmaceutical research and education. Prof. Singh completed his successful tenure in October 2021. Over his 40+ years of illustrious academic career, he trained 147 Masters and 15 PhD students in the fields of drug stability testing, degradation chemistry, impurity and metabolite characterization, and advanced analytical technologies. He has published ～250 research articles, reviews, editorials, patent, book, and book chapters, and received numerous awards, including the Professor M.L. Khorana Memorial Lecture Award from the Indian Pharmaceutical Association (IPA) and the Outstanding Analyst and Eminent Analyst awards from the Indian Drug Manufacturers' Association (IDMA). This commentary highlights Prof. Singh's inspiring personal and renowned professional journey, including early life, education, career, accomplishments, as well as his services to academia, industry, and regulatory. By sharing the contributions and accomplishments of Prof. Singh, we strongly believe that his story will inspire the next generation of scientists to continue his legacy to advance the field.     

A Tribute to Dr. William Penn Watkinson

Contrary findings are often found among epidemiological studies examining associations of different types of airborne particulates against the same health endpoints. Some studies of heart rate variability (HRV) in humans find associations with either regional particulate material 2.5 microns or smaller (PM_2.5) and/or with “sulfate” while some do not; some find associations with more local emissions such as black carbon (BC), while others do not. We explore if there might there be a consistent methodological explanation for inconsistent findings among HRV studies. To do this, we identify studies of HRV changes in humans examining associations with ambient PM_2.5 and sulfate, ambient PM_2.5 and BC, or all three; we briefly review findings and methodologies, including exposure issues; then we explore why studies may come to different conclusions.

We tentatively conclude that differences in accuracy of subject exposure information for health-relevant emissions such as BC, which vary spatially over short distances in urban areas, may explain conflicting study results. HRV studies with accurate exposure information for BC or urban/industrial PM_2.5 generally find large, significant associations with BC or urban/industrial PM_2.5, but rarely with secondary sulfate or regional emissions generally. However, absent accurate exposure information for BC, studies appear more likely to find associations with less spatially variable secondary sulfate or PM_2.5, and less likely to find strong associations with BC. However, research on this subject is limited, as are the number of studies evaluated here. Added research is necessary to confirm these findings (or otherwise), and to explore whether exposure misclassification might cause other health effects results to consistently vary.     

Editorial: A training program for parapathologists.

The effects of parathion [O,O-diethyl O-p-nitrophenyl phosphorothionate] administration on activities of acetyl-cholinesterase (AChE) in blood and pseudocholinesterase (ChE) in plasma were studied in bonnet (Macaca radiata) and rhesus (M. mulatta) monkeys. In addition, the effects of parathion administration on performance of learned visual discrimination tasks were studied in rhesus monkeys. Peak inhibition of AChE and ChE occurred about 6 hr after administration of 0.5, 1.0, and 2.0 mg/kg parathion po. The degree of peak inhibition was greater for ChE than for AChE, was dose-related for both enzymes, and was of about the same magnitude in both species, even though control values for AChE and ChE differed in the two species. Activities of both enzymes returned to control values within 2 wk at all dose levels. Administration of 2.0, 1.5, and 1.0 mg/kg parathion abolished performance of the learned tasks 5 hr later and for as long as 3–7 days. When performance of the tasks returned after the 2.0 mg/kg dose, the level of performance remained below pretreatment values for up to 3 wk. A dose of 0.5 mg/kg did not affect performance. Comparison of the present findings with other work showed that reversal of blood AChE and ChE inhibition after parathion administration occurred more rapidly in monkey than in man but required more time in monkey than in mouse. It was observed that scopolamine and methyl scopolamine also blocked visual discrimination performance.