Browsing by Author "Gajendra Singh"

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A study on the role of cortical epithelial cells in the development of female gonads in rat
(2002) Biswabina Ray; Gajendra Singh
Contrary to the belief by many workers that the gonadal blastema in rodents and sheep is derived from mesonephros alone, the present work convincingly suggests that proliferation of cortical cords arising out of the surface epithelium of the gonads significantly contributes to the gonadal cell mass in rat. Formation of distinct cortical cords, having well demarcated cellular margins, arising from the epithelial layer covering the gonads was observed. A few of these cords were long enough to suggest that they could contribute to the cellular mass of the gonadal stroma. Exposure to an antimitotoic agent cyclophosphamide (CP) during fetal life, before and after arrival of primodial germ cells (PGCs) in the gonad led to a total denudation of the epithelium from the surface of the developing gonad, arresting the availability of somatic cells of cortical origin. This denudation of surface epithelium can be ascribed either to (1) a direct effect of CP on the epithelial cells causing their death and necrosis and/or (2) making PGCs non-functional which are essential for the inductive influence on the cortical epithelium for proliferation. The non-availability of cortical cells probably led to faulty development of follicles in the ovary ending in maldevelopment of the gonad.
A variation of phrenic nerve: Case report and review
(Universidad de la Frontera, 2006) Prakash; Latha V. Prabhu; Jwalaram Kumar; Sampath Madhyastha; Gajendra Singh
During routine dissection in the Department of Anatomy following anatomical variations of phrenic nerve were observed on right side in the neck region of a middle aged cadaver. The phrenic nerve in its early course close to its origin was giving a communicating branch to C5 root of brachial plexus and at the level of the root of neck just before entering the thorax, the phrenic nerve was placed anterior to the subclavian vein. This unique case of phrenic nerve variation gains tremendous importance in context of subclavian vein cannulation, implanted venous access portals, and supraclavicular nerve block for regional anesthesia. © 2007 Sociedad Chilena de Anatom•br>.
Acrolein induces unilateral hypertrophy and associated histopathalogical changes during germ cell differentiation in mature rat ovary
(2009) Ajit K. Saxena; Divya Singh; Gajendra Singh
Acrolein is an important chemical molecule of the global environment. It has dual importance as a by product of industrial wastes, automobile exhaust, and secondly an active metabolite of cyclophosphamide metabolic pathway. Acrolein is highly reactive unsaturated three carbon aldehyde. The importance of this chemical molecule increased several folds because of high reactivity; therefore, study has been designed with the aim to evaluate the effect of low dose (1mg/kg body wt. /day), continuous exposure (i.p.) of acrolein alone or with ascorbate (5 mg/kg body wt) for 10 days to rats .Reproductive performance of the treated rats were observed by serial mating experiments with opposite sex of the same strain. Infertility (33%) was observed when compared with controls. Most interesting finding is significant reduction (P<0.001) in the size of germ cell - populations i.e. primary, secondary and graafian follicles in medulla as well as in cortex region of the ovary as observed in experimental group. In another set of experimental group where antioxidant (ascorbic acid) was supplemented along with acrolein which shows regeneration of germ cells proliferation, suggesting ascorbate help to prevent cell-damage during cell-division in female gonads. The study was also further extended to observed genetic damage in term of chromosomal aberrations assay which reveals that significant changes (p < 0.05) were observed when compared with control groups.
Alteration in the protein profile of rat testis following antenatal exposure of foetuses to cyclophosphamide during differentiation
(2002) Ajit Kumar Saxena; Gajendra Singh
Effect of cyclophosphamide treatment on protein profile in neonatal rat testis was investigated. Cyclophosphamide was administered in a single dose of 2, 10 or 20 mg/kg body weight on the 12th day of gestation, which is a critical time point for differentiation of gonads. The protein profile in the testis of the newly born pups was analyzed by SDS-PAGE. A quantitative and qualitative difference in the protein bands was found between untreated and treated groups. An over expression of a band corresponding to 20.0 kd, while a reduction in the band size of 68.0 kd and 44.0 kd was observed. There was a complete disappearance of band corresponding to 74.0 kd following cyclophosphamide treatment. The possible mechanisms and significance of such effects of cyclophoaphamide on the protein synthesis in the development of gonads is discussed.
Anatomic variations of superficial peroneal nerve: Clinical implications of a cadaver study
(2010) Prakash; Ajay Kumar Bhardwaj; Deepak Kumar Singh; T. Rajini; V. Jayanthi; Gajendra Singh
Superficial peroneal nerve and its branches are frequently at risk for iatrogenic damage. Although different studies on anatomical variations of superficial peroneal nerve are available in the medical literature, such reports are rare from India. Hence the present study was undertaken on Indian population. A total of 60 specimens of inferior extremities from 30 properly embalmed and formalin fixed cadavers were dissected and examined for the location and course of the superficial peroneal nerve including number, level, course and distributions of branches. The superficial peroneal nerve in 28.3% specimens was located in the anterior compartment of the leg. In 8.3% specimens the superficial peroneal nerve branched before piercing between the peroneus longus and extensor digitorum longus muscle whereas in 11.7% specimens it branched after piercing the aforementioned muscles and before piercing the deep fascia. In 41 out of 60 specimens the sensory division of superficial peroneal nerve branched into the medial dorsal cutaneous nerve and intermediate dorsal cutaneous nerve distal to its emergence from the deep fascia and proximal to its relation to the extensor retinaculum. In 20 out of 60 specimens the accessory deep peroneal nerve, an additional branch from the sensory division of superficial peroneal nerve, through its course in the anterior compartment of the leg passed deep to the extensor retinaculum and supplied the ankle and the dorsum of foot. Hopefully the present study will help in minimizing iatrogenic damage to the superficial peroneal nerve and its branches while performing arthroscopy, local anesthetic block, surgical approach to the fibula, open reduction and internal fixation of lateral malleolar fractures, application of external fixators, elevation of a fasciocutaneous or fibular flaps for grafting, surgical decompression of neurovascular structures, or miscellaneous surgery on leg, foot and ankle. © 2010 Firenze University Press.
Anatomical variations of peroneal muscles: A cadaver study in an Indian population and a review of the literature
(American Podiatric Medical Association, 2011) Prakash; Chinnaswamy Narayanswamy; Deepak Kumar Singh; Thimmiah Rajini; Jayanthi Venkatiah; Gajendra Singh
Background: Persistent lateral ankle pain is a common presentation in clinics. Various studies on anatomical variations of the peroneal compartment muscles, including the peroneus quartus muscle, have been reported in different populations. However, such studies are rarely from India. Hence, the present study was undertaken on cadavers in an Indian population. Methods: The lateral compartments of the legs were dissected in 70 specimens to study the presence, origin, and insertion of accessory muscles. Different peroneal tendons were observed for tears and splits. Results: Three of 70 specimens (4.3%) showed prevalence of the peroneus quartus muscle. Twenty specimens (28.6%) had split or tear lesions of the peroneus brevis muscle. Presence of the peroneus quartus muscle in this Indian population was relatively low compared with that in previous reports in English and American populations (6.6%- 21.9%). Conclusions: Racial differences, cultural variations, and postural habits, along with different stages of evolution, may be factors contributing to different observations. Split lesions of the peroneus brevis tendon were six to seven times more prevalent than was presence of the peroneus quartus muscle, which implies that split or tear lesions of the peroneus brevis tendon are more frequently involved in the manifestation of persistent retromalleolar pain compared with complications arising out of presence of the peroneus quartus muscle. Hence, accurate knowledge of presence of the peroneus quartus muscle in different populations is important because it can also be used in grafting and reconstruction in foot and ankle surgery.
Asymmetry in the weight and linear measurements of the bones of the lower limb
(2005) Gajendra Singh; Chhandamayee Mohanty
Though, there is a clear cut right dominance in the upper extremity, reports on lower extremity are ambiguous. The present study reports the side dominant pattern in the weight and length of 50 lower limb paired bones, collected from the skeletons of the eastern Uttar Pradesh and Bihar region. The bones were weighed in a single lot as well as separately. The length was measured on an osteometric board. In overall, there were higher incidences of heavier and longer bones on the right side, suggesting right dominance. The absolute weight and length of right extremity bones were also more. The tibia and fibula were best qualified as pointers towards right dominance in terms of both weight and length. There was higher incidence of heavier femur on the right side and longer femur on the left side, which was difficult to explain. The right dominance was considered a congenital phenomenon guided by contra lateral dominant left cerebral hemisphere.
Asymmetry in the weight and linear measurements of the bones of the upper limb
(2005) Gajendra Singh; Chhandamayee Mohanty
In both the sexes, the upper limb skeleton was found to be heavier and longer on the right side except clavicle which was found to be longer on the left side. Right side weight dominance was more prominent in female skeletons: 100% for radius and metacarpals and 93% for humerus. The right dominance of the upper limb skeleton was ascribed to the left cerebral hemisphere dominance. Comparatively longer clavicle on the left side is difficult to explain.
Centeromeric breakage and fragile site expression in cryptorchidism - A case report
(Scientific Publishers of India, 2010) Ajit Kumar Saxena; Divya Singh; Gajendra Singh
The present case was phenotypically male except that testes were not present in the scrotum. Hence in this case of cryptorchidism, the genetic study becomes imperative for thorough analysis. Chromosomal study revealed more than 13.3% centromeric breaks per cell in metaphase. The high incidence (3.6%) of common fragile sites expression (7q11, 2q21, 3p14) were also noticed after addition of 5-azacytidine. These genetic factors might influence the weight of the testis or alter hormonal level which is essential for normal growth and descent of testis in mammals.
Characterization of antiplatelet properties of silver nanoparticles
(2009) Siddhartha Shrivastava; Tanmay Bera; Sunil K. Singh; Gajendra Singh; P. Ramachandrarao; Debabrata Dash
Thrombotic disorders have emerged as serious threat to society. As anticoagulant and thrombolytic therapies are usually associated with serious bleeding complications, the focus has now shifted to regulating and maintaining platelets in an inactive state. In the present study we show that nanosilver has an innate antiplatelet property and effectively prevents integrin-mediated platelet responses, both in vivo and in vitro, in a concentration-dependent manner. Ultrastructural studies show that nanosilver accumulates within platelet granules and reduces interplatelet proximity. Our findings further suggest that these nanoparticles do not confer any lytic effect on platelets and thus hold potential to be promoted as antiplatelet/antithrombotic agents after careful evaluation of toxic effects. © 2009 American Chemical Society.
Characterization of enhanced antibacterial effects of novel silver nanoparticles
(Institute of Physics Publishing, 2007) Siddhartha Shrivastava; Tanmay Bera; Arnab Roy; Gajendra Singh; P. Ramachandrarao; Debabrata Dash
In the present study, we report the preparation of silver nanoparticles in the range of 10-15 nm with increased stability and enhanced anti-bacterial potency. The morphology of the nanoparticles was characterized by transmission electron microscopy. The antibacterial effect of silver nanoparticles used in this study was found to be far more potent than that described in the earlier reports. This effect was dose dependent and was more pronounced against gram-negative bacteria than gram-positive organisms. Although bacterial cell lysis could be one of the reasons for the observed antibacterial property, nanoparticles also modulated the phosphotyrosine profile of putative bacterial peptides, which could thus affect bacterial signal transduction and inhibit the growth of the organisms. © IOP Publishing Ltd.
Cyclophosphamide induced non-canalization of cerebral aqueduct resulting in hydrocephalus in mice
(2007) Prakash; Gajendra Singh; Sukhmahendra Singh
This study aims to understand the mechanism of failure of canalization of cerebral aqueduct following intrauterine exposure to reference teratogen, cyclophosphamide in murine pups. Non-canalization of cerebral aqueduct was found to result in internal hydrocephalus. Cyclophosphamide was administered to pregnant mice on day 10, 11, or 12 of gestation in a single dose of 20 mg/kg body weight. Fetuses were dissected out on day 19 and studied for hydrocephalus and other cerebral or cranial malformations. Serial sections of brain in coronal and transverse planes exhibited incomplete development and failure of canalization of cerebral aqueduct. Pressure of cerebrospinal fluid (CSF) in non-canalized aqueduct resulted in its rupture leading to leakage and accumulation of CSF in brain substance causing a cavity full of CSF close to unopened aqueduct. The large pool of CSF in the brain substance in extreme cases communicated with the subarachnoid space pushing through the substance of brain causing external hydrocephalus. Internal hydrocephalus on the other hand was resulted from back pressure of CSF following blockage in its flow due to non-canalization of the cerebral aqueduct. In the extreme cases internal and external hydrocephalus were seen intercommunicating. Cyclophosphamide induced inhibition of mitosis and cell differentiation of ependymal cells and augmentation of apoptosis of brain cells were attributed as the major causes underlying the incomplete development of cerebral aqueduct. The study also suggested inductive role of CSF in the differentiation of ependymal cells lining the cerebral aqueduct.
Cyclophosphamide induced polydactyly in mice: Understanding of underlying mechanism
(2005) Prakash; Gajendra Singh; S.M. Singh
Polydactyly with 6 or 7 digits bilaterally, or in all the four limbs at a time in certain cases was the principal finding amongst limb malformations in mice fetuses exposed to cyclophosphamide in the dose of 10 mg/kg body weight on day 11 of gestation. Duplication of great toe was the most dominant. Augmentation of apoptosis by cyclophosphamide resulting in excessive programmed cell death in additional interdigital zones due to altered induction from apical ectodermal ridge (AER) with subsiquent early and fast destruction of AER and mesoderm deep to it were suggested as the probable mechanisms. Bilateral manifestation or involvement of all the four paws in multiple cases suggested, homogeneous effect of cyclophosphamide on the process of differentiation i.e. administration of critical dose at critical period of differentiation of toes.
Cyclophosphamide-induced agenesis of cerebral aqueduct resulting in hydrocephalus in mice
(2007) Prakash; Gajendra Singh; Sukh Mahendra Singh
The present work was undertaken to reveal the mechanism of cerebral aqueduct agenesis found to result in hydrocephalus following intrauterine exposure to model teratogen, cyclophosphamide, in murine fetuses. A single dose of 10-mg/kg body weight cyclophosphamide was injected intaperitoneally to pregnant mice on day 10, 11 or 12 of gestation. Fetuses were collected through abdominal incision on day 18 and studied for various malformations of brain and cranium including hydrocephalus. Incomplete development and failure of canalization of the cerebral aqueduct were detected when serial sections of brain in coronal and transverse planes were studied under the microscope. Biotechnological investigations such as % DNA fragmentation, % viable cell count and cell proliferation assay were carried out on brain cells for further studies. Agenesis and non-canalization of the cerebral aqueduct resulted in increased pressure of CSF, which led to rupture of the aqueduct complicated by leakage and accumulation of CSF in brain substance forming a cavity containing CSF parallel and lateral to the unopened part of the cerebral aqueduct. Incomplete development along with non-canalization of the cerebral aqueduct resulted in blockage of CSF flow through the ventricles that manifest as internal hydrocephalus. External hydrocephalus on the other hand was detected where the CSF accumulated in the cavity formed inside the brain substance and established communication with the CSF in the subarachnoid space. Cyclophosphamide induced inhibition of mitosis and cell differentiation of ependymal cells reflecting a decreased % viable cell count and cell proliferation assay along with augmentation of apoptosis of brain cells quantified as increased % DNA fragmentation count, which were identified as the contributing factors underlying the agenesis and incomplete development of the cerebral aqueduct. The study also suggests that cell survival, proliferation, migration or differentiation of ependymal cells might have been affected, and we speculate that CSF may have an inducing role in the development and canalization of the cerebral aqueduct. © 2007 Springer-Verlag.
Double ureter and duplex system: A cadaver and radiological study
(2011) Prakash; Thimmiah Rajini; Jayanthi Venkatiah; Ajay Kumar Bhardwaj; Deepak Kumar Singh; Gajendra Singh
Purpose: To study the prevalence of duplex system and double ureter in cadavers and intravenous pyelograms in Indian population. Materials and Methods: Fifty cadavers were dissected and 50 intravenous pyelograms were examined on both (right and left) sides for the presence of duplex system and double ureter. Results: One male cadaver aged 43 years showed complete double ureter and duplex system on the right side and incomplete double ureter and duplex system on the left side. Another male cadaver aged 56 years showed incomplete double ureter and duplex system only on the right side. An intravenous pyelogram of a 43-year-old man showed incomplete double ureter along with duplex system on the right side. Conclusion: Developmental anomalies of the kidney, ureter, and urinary bladder should be kept in mind and promptly detected before the manifestations of aforementioned complications increase the morbidity of the affected individuals.
Effect of 5-fluorouracil and mitomycin on the healing of intestinal anastomosis
(2007) Vijay K. Shukla; Manoj Pandey; P.C.L. Das; S.K. Tiwary; J.P.N. Chansouria; Mohan Kumar; Gurpreet Singh; S.K. Pandey; Gajendra Singh
Objective: Antineoplastic agents affect the healing of intestinal anastomosis. The aim was to evaluate the effect of 5-fluorouracil (5-FU) and mitomycin on the healing of the intestinal anastomosis and their schedule of administration. Material and Methods: Eighty-nine male albino Charles Foster rats with a mean weight of 256.57 g were divided into six groups. Group A represents the control, while in others varying schedules of chemotherapy (5-FU and mitomycin) were administered. The sacrifices were made on days 7, 14 and 21 postoperatively and bursting pressure and hydroxyproline content were measured. Results: Nine rats died before completion of the experiment and were excluded. Adhesions were noted in all rats on sacrifice. The mean bursting pressure of normal intestine (group A) was 252 mm Hg. The bursting pressure was lower on day 7 (208 mm Hg) and it subsequently increased by day 21 (230 mm Hg). The mean bursting pressure in groups B, C, D and E was 174, 194, 182 and 188 mm Hg and it subsequently increased to 232, 272, 244 and 286 mm Hg. There was no difference in the pattern of bursting pressure in colon and ileum. The mean hydroxyproline content of ileum (group A) on day 7 was 34.37 mg/g tissue. The hydroxyproline content of the ileum in groups B, C, D and E was 15.08, 27.03, 7.75 and 21.04 mg/g tissue. There was a significant decrease in hydroxyproline content following anastomosis and chemotherapy. Conclusions: The effect of chemotherapy was pronounced when administered on the day of surgery or in the immediate pre- or postoperative period. Hence administration of chemotherapy during this period may be harmful. Copyright © 2007 S. Karger AG.
Effect of intraamniotic vitamin A on palatal closure of fetal rats
(2000) Chhandamayee Mohanty; Gajendra Singh
On day 15 of gestation, intraamniotic vitamin A in a dose of 150 IU was administered to the fetal rats to examine its effect on palatal closure. Fetuses subjected to only amniocentesis acted as control for the study. The fetuses were recovered on day 19, 20 and 21, respectively. Vitamin A resulted in poor development of palatine shelves. There was no clear demarcation of the base and the free margins of the shelves were either rounded or blunted with poor attempt towards closure. In the vitamin A group, the incidence of cleft palate were similar in all three days while there was a gradual decline with increasing gestational age in the amniocentesis group. The results suggest that unlike amniocentesis, in vitamin A treated fetuses, there was no attempt towards a delayed closure of the palate.
Effect of intrauterine exposure of murine fetus to cyclophosphamide on development of thymus
(2007) Prakash; Vivekanand Gupta; Sukh Mahendra Singh; Mahendra Pal Singh; Gajendra Singh
The objective of this study was to demonstrate thymic alterations produced by cyclophosphamide intervention during intrauterine life of murine fetus. Cyclophosphamide (CP) was administered to pregnant mice on day 11 of gestation in a single dose of 10 mg/kg body weight. Fetuses were dissected out on day 19 and studied for various effects on thymus. Thymus of fetuses exposed to cyclophosphamide showed thymic atrophy with retardation of thymic size and a remarkable shrinkage in lobular morphology. Histological studies showed a massive depletion of thymic cortex. Study of thymocytes revealed an increase in apoptotic cell count and percent DNA fragmentation along with a decrease in proliferation. Thymocytes obtained from fetuses of CP-treated mice showed a higher expression of caspase-activated DNase (CAD) indicating that the CP-dependent induction of apoptosis in thymocytes involved caspase pathway. The results of the present study may help in understanding the mechanism of the teratogenic effect of cyclophosphamide on thymus. Copyright © Informa Healthcare.
Effects of folate supplementation on cleft palate induced by lamotrigine or cyclophosphamide: An experimental study in mice
(2007) Prakash; Latha Venkatraya Prabhu; Gajendra Singh
This study aims to elucidate the preventive role of folate supplementation on induction of cleft palate in mice by drugs of two separate categories i.e. lamotrigine (newer antiepileptic and antipsychotic) and cyclophosphamide (anticancer and immunosuppressive). 10 pregnant swiss white mice (C) received normal saline intraperitoneally on day 10 of gestation. Two groups of 10 pregnant mice (T1) and (T2) each received lamotrigine or cycloposphamide respectively 10 mg/kg body weight (bw) intraperitoneally on day 10 of gestation. Folate was supplemented 0.8 μg/kg bw intraperitoneally along with lamotrigine or cyclophosphamide to two more groups of 10 pregnant mice (T3) and (T4) each respectively on the same day 10, of gestation. Fetuses were collected by Caesarian Section on day 18 of gestation. Fetuses collected from all the groups were examined macroscopically with stereomicroscope for palatal malformations. Coronal sections of fetal head were taken for histological study of palatine defects. Cleft palates were detected in 42 out of 70 (60.00%) fetuses of lamotrigine treated group (T1) and 49 out of 61 (80.33%) fetuses of cyclophosphamide treated group (T2). Folate supplementation resulted in different response; 15 out of 72 (20.83%) fetuses in T3 group and 51 out of 64 (79.69%) fetuses in T4 group had cleft palate. The difference was highly significant (p<0.001) when folic acid was administered with lamotrigine (T3) and was not significant (p>0.05) when it was administered with cyclophosphamide (T4) as compared to only lamotrigine (T1) or cyclophosphamide (T2) treated groups respectively. The preventive efficacies of folate supplementation for cleft palate vary considerably and in the same subject under identical conditions, depend primarily on the mechanism of action of the inducing agent.
Fetal central nervous system and thymic alterations following cyclophosphamide treatment of pregnant mice
(Universidad de la Frontera, 2007) Prakash; Gajendra Singh; Sukh Mahendra Singh
The present study assessed central nervous system (CNS) and immune system changes in murine fetuses after cyclophosphamide (CP) exposure during intrauterine life. A single CP dose of 0, 10, or 20mg/kg body weight was administered by intraperitoneal injection to pregnant mice (20/group) on day 11 of gestation (GD 11) and fetuses were evaluated on day 19 of gestation (GD 19). Fetuses were examined for external changes, and then the brains and thymuses were removed for further evaluations of histological changes, protein content, apoptotic cell count, DNA fragmentation, and in vitro cell proliferation using 1 fetus/litter for each assessment. Brains and thymuses from CP-exposed fetuses were smaller in size and distorted in overall shape compared to those from the control group. Estimated mean protein content (mg/mL) of brains was decreased in the CP-exposed groups. In both brain cells and thymocytes there was an increase in mean apoptotic cell counts and in mean percent DNA fragmentation in the exposed groups. The in vitro cell proliferation assays conducted with cells from exposed fetuses exhibited a mean decrease in the number of both brain cells and thymocytes generated. These findings indicate that maternal CP treatment on GD 11 in mice results in marked fetal toxicity characterized by reduced live litter size, fetal body weights as well as brain and thymic weights and malformations which are accompanied by changes in brain protein content, brain and thymic apoptosis, DNA fragmentation and in vitro cell proliferation at term.