Ravi Kant Narayan

Dr. B.C.Roy Multi Speciality Medical Research Centre. IIT Kharagpur · Anatomy

The testicular arteries (TAs) also known as Internal spermatic arteries are long and slender arteries usually arising from the anterolateral aspect of the abdominal aorta (AA), 2.5 cm to 5 cm caudal to the renal arteries (RA). The variation in testicular arteries may be found with respect to their origin, number or course. They can originate from t...

Introduction: The prostate is a pyramidal shaped, fibromuscular glandular organ which surrounds the prostatic urethra. Three pathologic processes affect the prostate gland: Inflammation, Benign prostatic (Nodular) hyperplasia, and tumours. Of these three, the benign nodular hyperplasia and prostatic carcinoma are prevalent worldwide. Main treatment...

Background: The etiology of schizophrenia is extensively debated, and multiple factors have been contended to be involved. A panoramic view of the contributing factors in a genome-wide study can be an effective strategy to provide a comprehensive understanding of its causality. Materials and Methods: GSE53987 dataset downloaded from GEO-database, w...

Error in localization of mandibular foramen is attributed to a high failure rate of inferior alveolar nerve block in clinical dentistry. We hypothesized that a remodelled approach towards exploring the morphology of mandibular foramen would be useful. In the present study, the location of the mandibular foramen was analysed with respect to the anat...

Introduction: Inter-individual variations in specific cortical sulci were often reported but comprehensive sulcal patterns were never studied sufficiently. Further, any study which described sulcal variations between the two hemispheres of the same individuals, are scarce in literature. A variation in the sulcal pattern of brain will create a corti...

The foot arches in humans are the complex musculo-skeletal-ligamentous structure that helps in shock absorption because of the elasticity and provides stability while transmitting the muscle force for walking. Primarily we observed the prevalence of flatfoot among adolescents going to college. Thereafter we determined the correlation of flatfoot wi...

Background Radiology is among India's top five speciality choices pursued by meritorious medical graduates. With the advent of the subspecialization degree courses, fellowships, the requirement of senior residency as faculty eligibility criteria, and the lucrative option of private practice, the final-year postgraduates are given opportunities to c...

Background: The auditory tube (AT), an osteocartilaginous channel, connects the nasopharynx to the middle ear cavity. At the nasopharyngeal opening of the AT, there are dense collections of submucosal glands. In a recent article, Valstar et al. proposed these nasopharyngeal tubal glands conglomerate as salivary glands, which starkly contrasts with...

BACKGROUND Delta variant (B.1.617.2) was considered the most dangerous SARS-CoV-2 strain; however, in-depth studies on its impact on demographic and clinical characteristics of COVID-19 are scarce. OBJECTIVE We aimed to investigate the shift in demographic and clinical characteristics of the COVID-19 pandemic with the emergence of the SARS-CoV-2 d...

The retroperitoneal adrenals are situated in the epigastric region of the abdomen, on the upper pole of either kidney. The glands are golden-yellow in color. The right adrenal is triangular or pyramidal, and the left one is semi-circular or crescentic in shape. The blood supply rate per gram of tissue for the adrenal gland is one of the highest. Th...

Emerging evidence suggests a detrimental impact of COVID-19 illness on the continued hippocampal neurogenesis in adults. In contrast, the existing literature supports an enhancing effect of COVID-19 vaccination on adult hippocampal neurogenesis. Vaccines against respiratory infections, including influenza, have been shown to enhance hippocampal neu...

BACKGROUND A newly emerged SARS-CoV-2 variant B.1.1.529 worried the health policy makers worldwide due to a large number of mutations in its genomic sequence, especially in the spike protein region. World Health Organization (WHO) designated it as a global variant of concern (VOC) and was named 'Omicron.' Following Omicron's emergence, a surge in n...

Background Emergence of the new SARS-CoV-2 variant B.1.1.529 worried health policy makers worldwide due to a large number of mutations in its genomic sequence, especially in the spike protein region. The World Health Organization (WHO) designated this variant as a global variant of concern (VOC), which was named “Omicron.” Following Omicron’s emerg...

UNSTRUCTURED India has witnessed a devastating second wave of COVID-19, which peaked during the last week of April and the second week of May, 2021. We aimed to understand whether the arrival of second wave was predictable and whether it was driven by the existing SARS-CoV-2 strains or any of the emerging variants. We analyzed the monthly distribut...

Background Since the start of the COVID-19 pandemic, health policymakers globally have been attempting to predict an impending wave of COVID-19. India experienced a devastating second wave of COVID-19 in the late first week of May 2021. We retrospectively analyzed the viral genomic sequences and epidemiological data reflecting the emergence and spr...

Ha transcurrido más de un año y medio desde el inicio de la pandemia debida a la enfermedad por coronavirus 2019 (COVID-19), y el mundo se esfuerza por contenerla. Al ser causada por un virus hasta ahora desconocido, en el periodo inicial hubo una escasez extrema de conocimientos sobre los mecanismos de la enfermedad, lo que dificultó las medidas p...

The suprarenal arteries are arising from three sources: superior suprarenal artery, middle suprarenal artery, and inferior suprarenal artery. Variations in the arterial supply of the suprarenal glands in respect to origin and number are quite common and very frequently reported. The most common variation noted is in the inferior suprarenal artery f...

Background: A newly emerged SARS-CoV-2 variant B.1.1.529 has worried health policymakers worldwide due to the presence of a large number of mutations in its genomic sequence, especially in the spike protein region. World Health Organization (WHO) has designated it as a global variant of concern (VOC) and has named as Omicron. A surge in new COVID-1...

Young age, female sex, absence of comorbidities, and prior infection or vaccination are known epidemiological barriers for contracting the new infection and/or increased disease severity. Demographic trends from the recent COVID‐19 waves, which are believed to be driven by newer SARS‐CoV‐2 variants, indicate that the aforementioned epidemiological...

Background: The dural fold between anterior and middle clinoid processes on mineralization leads to the formation of caroticoclinoid foramen. Different morphology of this foramen presents with different clinical features. The present study reports the frequency of caroticoclinoid foramen in the population of Bihar, while providing an account of ass...

More than one and a half years have elapsed since the commencement of the coronavirus disease 2019 (COVID-19) pandemic, and the world is struggling to contain it. Being caused by a previously unknown virus, in the initial period, there had been an extreme paucity of knowledge about the disease mechanisms, which hampered preventive and therapeutic m...

More than one and half years have elapsed since the commencement of the COVID-19 pandemic and the world is struggling to contain it. Being caused by a previously unknown virus, in the initial period, there had been an extreme paucity of knowledge about the disease mechanisms, which hampered preventive and therapeutic measures against COVID-19. In a...

The sternalis muscle (SM) is an anatomical variant that lies subcutaneously and is superficial to the pectoralis major muscle or sternum. The present meta-analysis was conducted to analyze the prevalence, anatomical features, and variance of the SM in different population. In total, 98 studies were included for this meta-analysis. Eighty-two studie...

Importance: Higher risks of contracting infection, developing severe illness and mortality are known facts in aged and male sex if exposed to the wild type SARS-CoV-2 strains (Wuhan and B.1 strains). Now, accumulating evidence suggests greater involvement of lower age and narrowing the age and sex based differences for the severity of symptoms in i...

Context. On naked eye examination adrenal myelolipoma (AML) tissue appears to be an ectopic adrenal or renal tissue, based on the similarity to their external texture. This necessitates a histo-pathological study for confirming the origin of the tissue. Objective. To establish the origin and histological features of the incidental AML tissue found...

Background Becoming acquainted with the variants of the inferior phrenic artery is crucial for surgeries done for compression syndrome of the coeliac trunk. Awareness of the arterial variations of the suprarenal gland is important while performing surgical and radiological interventions of this gland and its surrounding structures. Materials and m...

Raymond de Vieussens was an exemplary anatomist who made seminal contributions in the field of cardiology. During initial part of his academic career, he adopted human dissection based experiments as medium of his research. This was in accordance with prevailing trend among anatomists during 17th century. He discovered the presence of tiny venous t...

Purpose: Vaccine breakthrough infections have been frequent during the second wave of COVID-19 in India. We made an assessment of the severity of illness in breakthrough cases of COVID-19 using an online survey conducted during the period of second wave. Methods: An online questionnaire was circulated among healthcare workers across multiple medica...

Recent epidemiological studies analyzing sex disaggregated patient data in COVID-19 across the world revealed a distinct sex bias in the disease morbidity as well as the mortality-both being higher for the men. Similar antecedents have been known for the previous viral infections, including from coronaviruses, such as severe acute respiratory syndr...

Background: The core elements of cardiovascular science have been established by scholarly pursuits of numerous scientists across centuries. In this article, we have tried to trace the evolutionary journey of cardiovascular science from a rudimentary form in ancient period to a robust scientific discipline in modern times. Methods: A literature se...

India has witnessed a devastating second wave of COVID-19, which peaked during the last week of April and the second week of May, 2021. We aimed to understand whether the arrival of second wave was predictable and whether it was driven by the existing SARS-CoV-2 strains or any of the emerging variants. We analyzed the monthly distribution of the ge...

The rotator cuff is the prime stabilizer of the glenohumeral or shoulder joint. The last decade saw introduction of three components, namely, rotator cable, rotator crescent, and rotator interval of rotator cuff, which were being studied and published in dozen of literatures belonging to clinical specialties of orthopaedics and radiology. At times...

Introduction The proximal insertion beyond coracoid process of pectoralis minor is considered as hidden culprit of rotator cuff disorders. The ectopic insertion is also associated with thoracic outlet syndrome. The current review was conducted to provide a comprehensive evidence-based assessment of the anatomical characteristics of ectopic insertio...

Introduction: Orbital fractures are commonly reported following injury to maxillofacial region. Management of these fractures often poses a challenge due to potential involvement of a number of anatomical structures. Hence this study was attempted to collate the anatomical details relevant to clinical presentation of orbital fracture as available i...

Context: On naked eye examination adrenal myelolipoma (AML) tissue appears to be an ectopic adrenal or renal tissue, based on the similarity to their external texture. This necessitates a histo-pathological study for confirming the origin of the tissue. Objective: To establish the origin and histological features of the incidental AML tissue fou...

For long the CNS had been considered to lack lymphatics. The last few years have been spotted with works conflicting the immune-privilege status of CNS. Experimental evidence has assured the presence of lymphatics in the meninges, the meningeal lymphatic vessels (mLVs), along the venous sinuses carrying the immune cells along with drainage of cereb...

Intense immunological dysregulation including immune cell lesions has been characteristically observed in severe cases of coronavirus disease-2019 (COVID-19), for which molecular mechanisms are not properly understood. A study of physiological expressions of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) host cell entry-related factor...

Introduction: The aim of present study was to undertake detailed analysis of variations in morphology of orbito-meningeal foramen (OMF), a clinically relevant entity due to possible association with major arterial branches. Materials & Methods: The study was conducted on 70 bony orbits of 35 dry adult human skulls. Precise identification of OMF’s...

Objective: Osteoarthritis (OA) and age-related degeneration (ARD) are stimulants for the development of the fabella in the knee joint. This meta-analysis updates previous studies and reviews on the prevalence of the fabella in OA or ARD knee joints. In addition, it provides a quantitative estimation of the fabellar prevalence in knees having OA an...

The pandemic of the coronavirus disease, 2019 (COVID-19) has caused millions to suffer from the disease and to die globally. Global epidemiological statistics reflect, significantly more numbers of men, aged, those suffering from co-morbidities, and people facing socio-economic inequalities, such as, racial/ethnic minorities, have been affected by...

Recently, an article by Valstar et al was published in Radiotherapy and Oncology journal, which claimed to discover a pair of macroscopic salivary glands located in the dorsolateral nasopharynx around the Eustachian Tube (ET), and termed as tubarial salivary glands [ 1 ]. Authors proposed that these tubarial glands present a potential new organ. Th...

Ongoing epidemic of Coronavirus disease (COVID-19) has presented new challenges to the oncologists. Recent studies have suggested higher COVID-19 related mortality in cancer patients,[1] reasons for which are currently little understood. Although, COVID-19 primarily causes acute respiratory distress syndrome (ARDS), widespread inflammation and mult...

Lack of standardized therapeutic approaches is arguably the significant contributor to the high burden of mortality observed in the ongoing pandemic of the Coronavirus disease, 2019 (COVID-19). Evidence is accumulating on SARS-CoV-2 specific immune cell dysregulation and consequent tissue injury in COVID-19. Currently, no definite drugs or vaccines...

Paucity of knowledge about SARS-CoV-2 specific virulence factors has greatly hampered therapeutic management of patients with COVID-19. Recently, a cluster of studies appeared, which presented empirical evidence for SARS-CoV-2 specific virulence factors that can explain key elements of COVID-19 pathology. These studies unravel multiple structural a...

The ongoing coronavirus disease-2019 (COVID-19) pandemic has raised significant public health issues which need to be attended. To enable efficient handling of the situation and prevent the spread of the epidemic, healthcare professionals require various standard operating procedures (SOPs). Emerging evidence suggests high infectivity of the novel...

The article is presenting a bioinformatics based method predicting susceptibility for SARS‐CoV‐2 infection in domestic and wildlife animals. Recently, there were reports of cats and ferrets, dogs, minks, golden hamster, rhesus monkeys, tigers, and lions testing for SARS‐CoV‐2 RNA which indicated for the possible interspecies viral transmission. Our...

Introduction: Most popular approach for maxillary nerve block is via greater palatine canal (GPC) which is often difficult to access due to anatomical variations of its entry point the greater palatine foramen (GPF) thus resulting in failure of nerve block. It was hypothesized that exploring morphology of GPF with a modified approach may be useful...

Structure - function interdependence is a universal phenomenon in biological systems. Any alteration in structural features may result in change in functions–leading to natural selection of a particular trait, or dysfunctions thereof. Many such alterations arise during the course of evolution of a species and may meticulously be traced during embry...

Sev­eral stud­ies have de­scribed un­usu­ally high in­ci­dence of vas­cu­lar throm­bo­sis in coro­n­avirus dis­ease-2019 (COVID-19) pa­tients. Patho­gen­e­sis of the vas­cu­lar throm­bo­sis in COVID-19 is least un­der­stood for now and pre­sents a chal­lenge to the treat­ing physi­cians. Se­vere acute res­pi­ra­tory syn­drome coro­n­avirus-2 (SARS-...

Therapeutic administration of steroids (or corticosteroids) in patients with coronavirus disease (COVID-19) is controversial owing to risk of adrenal insufficiency or immunosuppression from their prolonged use. A recent clinical trial report presenting preliminary data suggested survival benefits of low-dose dexamethasone in patients with severe CO...

COVID-19 is caused by a new strain of coronavirus called SARS-coronavirus-2 (SARS-CoV-2), which is a positive sense single strand RNA virus. In humans, it binds to angiotensin converting enzyme 2 (ACE2) with the help a structural protein on its surface called the S-spike. Further, cleavage of the viral spike protein (S) by the proteases like transm...

Abstract: The novel corona virus which was detected for the first time in Wuhan city, Hubei province, China in December, 2019, rapidly spread all over the world to be recognized as pandemic by March, 2020. Although, initially, the major symptoms were related to the respiratory system but gradually several manifestations have surfaced, thus making o...

Manifestation of neurological symptoms in certain patients of coronavirus disease‐2019 (COVID‐19) has warranted for their virus‐induced etiogenesis. SARS‐CoV‐2, the causative agent of COVID‐19, belongs to the genus of betacoronaviruses which also includes SARS‐CoV‐1 and MERS‐CoV; causative agents for severe acute respiratory syndrome (SARS) in 2002...

Epidemics are supposed to hit urban areas with dense populations and poor socioeconomic conditions—slums—hardest. Globally, covid-19 is following this pattern. We have, however, seen a rare exception in Dharavi, Mumbai, Maharashtra, India.

Objective: Error in localization of mandibular foramen is attributed to a high failure rate of inferior alveolar nerve block in clinical dentistry. We hypothesized that a remodelled approach towards exploring the morphology of mandibular foramen would be useful. in the present study the location of the mandibular foramen was analysed with respect t...

Introduction & Objective: The ossification of the ligamentous or dural fold connection between anterior and middle clinoid process known as carotico -clinoid foramen (CCF) and that between anterior and posterior clinoid processes is known as the sella turcica bridge (STB). This study explains the possible effects and complications due to an ossifie...

Introduction: Intense immunological dysregulation including immune cell lesions have been characteristically observed in severe cases of Coronavirus Disease-2019 (COVID-19), for which molecular mechanisms are least understood. A study of physiological expressions of SARS-CoV-2 host cell entry related factors in immune system components may help exp...

The ongoing pandemic of Coronavirus disease-2019 (COVID-19) has threatened millions of lives globally. An effective vaccine against COVID-19 is need of the hour. India has been a hub for vaccine productions and Indian pharmaceutical companies have contributed immensely to the vaccine related projects running all over the world. Indian companies hav...

The aim of the study was to document an anatomical variation around the sella turcica which was unique and lacked any reference in the literature. A low lying osseous bar connecting the right middle clinoid process to the midpoint of the right lateral border of the dorsum sella was observed in a human skull specimen. The osseous bar was forming a f...

Does the prevalence of fabella vary in knee osteoarthritis and age-related degeneration? A meta-analysis of over 11,000 knees. Abstract Introduction: Osteoarthritis (OA) and age-related degeneration (ARD) are stimulants for the development of the fabella in the knee joint. This meta-analysis updates previous studies and reviews on the prevalence of...

Digestive symptoms are prominent in a significant fraction of Coronavirus disease-2019 (COVID-19) patients. Detection of the active virus (SARS-CoV-2) and viral RNA have been noted in the stool samples of some COVID-19 patients which indicates potential infectivity and replication of the virus in the human gut. Gut infectivity by the virus has been...

Recent literature suggested increased risk of severe COVID-19 in smokers. However, original peer reviewed research which explained pathophysiological basis of the enhanced COVID-19 severity in smokers is currently scarce. Based on the recent research updates on SARS-CoV-2 specific virulence in host cells, we propose a plausible mechanism which can...

Scholars began exploring anatomy of nervous system from ancient times; however, considerable progress could only be made during the European Renaissance from the 14th century onwards. The present study aimed to document significant discoveries in this context in chronological order to establish the cascading pattern of advancement in knowledge. The...

This article is protected by copyright. All rights reserved. Abstract A recent article published in Nature Metabolism, 'A network of trans-cortical capillaries as a mainstay for blood circulation in long bones' by Grüneboom et al. (2019), explained the long bone vascularity. In the mouse model, the authors demonstrated hundreds of transcortical ves...

Read at Science Immunology https://immunology.sciencemag.org/content/5/47/eabc3582/tab-e-letters

COVID-19, is caused by a new strain of coronavirus called SARS-coronavirus-2 (SARS-CoV-2), which is a positive sense single strand RNA virus. In humans, it binds to angiotensin converting enzyme 2 (ACE2) with the help a structure on its surface called the S-spike. COVID-19 poses intriguing issues with imperative relevance to clinicians. The pathoge...

The SARS-CoV-2 is a recently identified positive sense single stranded RNA virus and member of the coronavirus family of viruses. It is thought to be the etiological factor for the ongoing COVID-19 pandemic. This virus is thought to have originated from bats and acquired ability of human-to-human transmission. While SARS-CoV-2 is relatively benign,...