Persistent left superior vena cava: An anatomical variation.

The persistent left superior vena cava (LSVC) is a common anomaly of congenital heart disease. The presence of LSVC is commonly associated with other congenital cardiac anomalies such as atrial septal defect, tetralogy of fallot, aortic coarctation, ventricular septal defect and very rarely it occurs as an isolated finding. During a routine dissection for undergraduate students, a persistent LSVC along with variation in anterior cardiac vein and right septal pouch (RSP) was observed in heart of an approximately 48-year-old male cadaver. The persistent LSVC was draining into the right atrium via coronary sinus. The persistent LSVC is usually insignificant haemodynamically as commonly it drains into right atrium via coronary sinus, but incidental finding of LSVC is important to surgeons, interventional nephrologists and radiologists before placement of central venous access device. The insertion of central venous catheter via left internal jugular vein is difficult in presence of persistent LSVC. The right superior vena cava was normal. An anterior cardiac vein joined with the right marginal vein to form a common vein. The common vein opened into the right atrium. We also observed a RSP attached to the limbus fossa ovalis inferiorly which is a kangaroo pouch-like structure. A septal pouch is potential site predispose to thrombus formation and is more common on left side. In this case report we discuss embryology, clinical significance and review of literature related to persistent LSVC, anterior cardiac vein and SP.

Chronic co-administration of nalbuphine attenuates the development of opioid dependence.

Nalbuphine is an agonist of κ-opioid receptors and a partial agonist of µ-opioid receptors, which can stimulate κ-receptors and antagonize the acute rewarding effects of morphine. It is widely used either as an analgesic or as an adjuvant with morphine. This present study aimed to compare the acute and chronic effects of nalbuphine on the naloxone-precipitated opiate-withdrawal in rats. Male adult Wistar albino rats (150-175 g, n = 160) were made physically dependent by administrating increasing dose of morphine (5-25 mg/kg; i.p.). Motor activity was measured for 25 min at five-minute intervals on days 0, 1, 3, 5, and 6 using Activity Monitor (Coulbourn Instruments, Inc. USA) and True-scan software. The withdrawal was precipitated with intraperitoneal injections of naloxone (1 mg/kg) 4 h after the last injection of morphine. Somatic signs of withdrawal were scored using the global Gellert-Holtzman rating scale. Nalbuphine was co-administered acutely and chronically at various doses (0.1, 0.3, 1.0, and 3.0 mg/kg; i.p.) with morphine. In general, the opiate-dependent rats showed a significant increase in motor activity and Gellert-Holtzman score. Animals co-administered with chronic doses of nalbuphine showed a significant decrease in motor activity and naloxone-precipitated opiate withdrawal, but acute nalbuphine treatment did not attenuate the development of opioid dependence. These findings suggest that nalbuphine could be used as an effective pharmacological adjunct in the treatment of opioid addiction.

Standardization of the technique of silicon injection of human cadaveric heads for opacification of cerebral vasculature in Indian conditions.

A surgeon's understanding of the surgical anatomy can be greatly enhanced by the dissection of preserved cadaveric specimens. A reliable and inexpensive biological model for testing and standardization of dye injection concentrations is proposed utilizing the goat's head as a biological model. The first phase was concerned with standardization of the dye by titrating its concentration and injecting various amounts into cerebral vessels of a goat's head until an optimal concentration had been ascertained. In the second phase, this optimum concentration of the dye was injected into four human cadaveric heads following the same technique standardized using the goat's head. Upon dissecting the four cadaveric human heads which were injected with silicon dyes and preserved in 10% formalin, the vessels were all well-opacified and the brain was of near normal consistency and good for dissection, without showing any features of putrefaction. The goat model, having similar color, texture, and the handling as the cadaveric head, offers an opportunity to test indigenously manufactured polymerizing dyes in the future. This biological model, therefore, has the potential to considerably reduce the cost of cadaver preparation.

Fluoride-associated ultrastructural changes and apoptosis in human renal tubule: a pilot study.

The susceptibility of the kidneys to fluoride toxicity can largely be attributed to its anatomy and function. As the filtrate moves along the complex tubular structure of each nephron, it is concentrated in the proximal and distal tubules and collecting duct. It has been frequently observed that the children suffering from renal impairments also have some symptoms of dental and skeletal fluorosis. The findings suggest that fluoride somehow interferes with renal anatomy and physiology, which may lead to renal pathogenesis. The aim of this study was to evaluate the fluoride-associated nephrotoxicity. A total of 156 patients with childhood nephrotic syndrome were screened and it was observed that 32 of them had significantly high levels ( p ≤ 0.05) of fluoride in urine (4.01 ± 1.83 ppm) and serum (0.1 ± 0.013 ppm). On the basis of urinary fluoride concentration, patients were divided into two groups, namely group 1 (G-1) ( n = 32) containing normal urine fluoride (0.61 ± 0.17 ppm) and group 2 (G-2) ( n = 32) having high urine fluoride concentration (4.01 ± 1.83 ppm). Age-matched healthy subjects ( n = 33) having normal levels of urinary fluoride (0.56 ± 0.15 ppm) were included in the study as control (group 0 (G-0)). Kidney biopsies were taken from G-1 and G-2 only, who were subjected to ultrastructural (transmission electron microscopy) and apoptotic (terminal deoxynucleotidyl transferase deoxyuridine triphosphate nick end labeling) analysis. Various subcellular ultrastructural changes including nuclear disintegration, chromosome condensation, cytoplasmic ground substance lysis, and endoplasmic reticulum blebbing were observed. Increased levels of apoptosis were observed in high fluoride group (G-2) compared to normal fluoride group (G-1). Various degrees of fluoride-associated damages to the architecture of tubular epithelia, such as cell swelling and lysis, cytoplasmic vacuolation, nuclear condensation, apoptosis, and necrosis, were observed.

Morphological and morphometrical maturation of ventral cochlear nucleus in human foetus.

Auditory impulses perceived by the hair cells of the organ of corti are relayed in the cochlear nucleus, the first relay station in the brainstem, by the cochlear nerve. The human foetus is well known to respond to sound during the last trimester of gestation. On the contrary, studies conducted in rat, cat and mouse have shown that these mammals have an immature auditory system at the time of birth. There are very few reports available regarding the morphological and functional maturation of the cochlear nucleus in human. Although the human cochlear nucleus neurons attain adult morphological characters by mid-gestation, there are hardly any studies discussing the functional maturation of the cochlear nucleus. Hence the present study was aimed at observing the morphological as well as functional maturation of the human foetal cochlear nuclei at various gestational ages. Morphological maturation was observed qualitatively while stereological estimation of the volume of well defined ventral cochlear nucleus (VCN) was calculated by the Cavalieri principle; neuronal count and density was estimated by dissector principle. The functional maturation was assessed by observing the expression of synaptophysin, a synaptic marker, at different gestational ages and by the presence of parvalbumin, a calcium binding functional neuronal marker by immunohistochemistry. Neurons showed coarse Nissl's substance and well developed cell processes and gradual increase in cell size by the 24th-30th gestational week. Synaptophysin labeling in the complete cochlear nucleus was observed at 20 weeks of gestation. Adult pattern of synaptophysin labeling was observed finally at37weeks of gestation. Earliest presence of parvalbumin expression was detected at 16 weeks of gestation and a distinct adult pattern was seen at 37 weeks of gestation. This study concluded that morphological and functional maturation of the human cochlear nuclei occurs simultaneously during mid-gestation which represents the critical period of development and continues up to term.

Comparison of unbiased stereological estimation of total number of cresyl violet stained neurons and parvalbumin positive neurons in the adult human spiral ganglion.

Estimation of total number of neurons in the spiral ganglion (SG) at various ages and their functional status is important as these neurons are constantly exposed to noise and other environmental factors that may lead to neuronal loss with aging due to excitotoxic damage. Parvalbumin (PV) is a calcium-binding protein (CBP), found in highly metabolically active neurons. It helps in buffering cytosolic calcium, which is essential for neurotransmitter release. The neurons in the adult human SG express PV more strongly than other CBPs like calbindin and calretinin. These CBPs can be used as signatures to recognise neurons. In the present study, we quantified the number of neurons expressing PV by unbiased stereology and compared it to the number of neurons stained by cresyl violet (CV), which is a Nissl stain, in the adult human SG. Five adult human cadaveric temporal bones were obtained from the forensic science mortuary, after due clearance from the institute ethics committee. Independent CV stained and PV immunostained sections were used to estimate the total number of neurons (optical fractionator), with StereoInvestigator (SI) software. The estimated total number of SG neurons was 27,485±3251 and 26,705±1823 in the PV and CV stained sections, respectively. There was no significant difference between the estimates (p=0.552). Therefore, CV staining is simpler and more cost effective when estimating neuronal number. Although PV stains spiral ganglion neurons (SGNs) with a greater intensity and provides a functional status, its tedious protocol limits its use for quantification.

An Evaluation of the Surgical Trauma to Intracochlear Structures After Insertion of Cochlear Implant Electrode Arrays: A Comparison by Round Window and Antero-Inferior Cochleostomy Techniques.

To evaluate the extent of intracochlear damage by histologic assessment of cadaveric temporal bones after insertion of cochlear implants by: round window approach and cochleostomy approach. Cochlear implantation was performed by transmastoid facial recess approach in 10 human cadaveric temporal bones. In 5 temporal bones, electrode insertion was acheieved by round window approach and in the remaining 5 bones, by cochleostomy approach. The bones were fixed, decalcified, sectioned and studied histologically. Grading of insertion trauma was assessed. In the round window insertion group, 2 bones had to be excluded from the study: one was damaged during handling with electrode extrusion and another bone did not show any demonstrable identifiable cochlear structure. Out of the 3 temporal bones, a total of 35 sections were examined: 24 demonstrated normal cochlea, 4 had basilar membrane bulging and 7 had fracture of bony spiral lamina. In the cochleostomy group, histology of 2 bones had to be discarded due to lack of any identifiable inner ear structures. Out of the 3 bones studied, 18 sections were examined: only 3 were normal, 4 sections had some bulge in spiral lamina and 11 had fracture of bony spiral lamina. The fracture of spiral lamina and bulge of basement membrane proportion is relatively higher if we perform cochleostomy as compared to round window approach. Therefore, round window insertion is relatively less traumatic as compared to cochleostomy. However, our sample size was very small and a study with a larger sample is required to further validate these findings.

Growth and refinement of excitatory synapses in the human auditory cortex.

We had earlier demonstrated a neurofilament-rich plexus of axons in the presumptive human auditory cortex during fetal development which became adult-like during infancy. To elucidate the origin of these axons, we studied the expression of the vesicular glutamate transporters (VGLUT) 1 and 2 in the human auditory cortex at different stages of development. While VGLUT-1 expression predominates in intrinsic and cortico-cortical synapses, VGLUT-2 expression predominates in thalamocortical synapses. Levels of VGLUT-2 mRNA were higher in the auditory cortex before birth compared to postnatal development. In contrast, levels of VGLUT-1 mRNA were low before birth and increased during postnatal development to peak during childhood and then began to decrease in adolescence. Both VGLUT-1 and VGLUT-2 proteins were present in the human auditory cortex as early as 15GW. Further, immunohistochemistry revealed that the supra- and infragranular layers were more immunoreactive for VGLUT-1 compared to that in Layer IV at 34GW and this pattern was maintained until adulthood. As for VGLUT-1 mRNA, VGLUT-1 synapses increased in density between prenatal development and childhood in the human auditory cortex after which they appeared to undergo attrition or pruning. The adult pattern of VGLUT-2 immunoreactivity (a dense band of VGLUT-2-positive terminals in Layer IV) also began to appear in the presumptive Heschl's gyrus at 34GW. The density of VGLUT-2-positive puncta in Layer IV increased between prenatal development and adolescence, followed by a decrease in adulthood, suggesting that thalamic axons which innervate the human auditory cortex undergo pruning comparatively late in development.

Anomalous cutaneous branch of median nerve in arm: a report of anatomical variation with clinical implications.

The objective of the study was to observe and document the variation on the subject of branches of the median nerve. This report will assist clinicians and surgeons by considering anatomical variation associated with the median nerve in interpreting atypical clinical presentations. The arm and forearm region of a 55 year embalmed male cadaver during educational gross anatomy dissection. We found that an anomalous cutaneous branch arising from the median nerve in the right arm which was passing deep to the tendon of the biceps brachii. Later it enters the cubital fossa and then it is accompanied by the superficial vein of the forearm. The other limb of the cadaver did not show any such variation. No other neural, arterial or muscular variation was observed in either of the limbs. A rare anatomical variation in which the anomalous cutaneous branch arising from the median nerve in the right arm which is later accompanied by a superficial vein in the forearm. Such knowledge is advantageous in nerve grafting and neurophysiological evaluation for diagnosing peripheral neuropathies.

Effect of prenatal loud music and noise on total number of neurons and glia, neuronal nuclear area and volume of chick brainstem auditory nuclei, field L and hippocampus: a stereological investigation.

The present study explores whether prenatal patterned and unpatterned sound of high sound pressure level (110 dB) has any differential effect on the morphology of brainstem auditory nuclei, field L (auditory cortex analog) and hippocampus in chicks (Gallus domesticus). The total number of neurons and glia, mean neuronal nuclear area and total volume of the brainstem auditory nuclei, field L and hippocampus of post-hatch day 1 chicks were determined in serial, cresyl violet-stained sections, using stereology software. All regions studied showed a significantly increased total volume with increase in total neuron number and mean neuronal nuclear area in the patterned music stimulated group as compared to control. Contrastingly the unpatterned noise stimulated group showed an attenuated volume with reduction in the total neuron number. The mean neuronal nuclear area was significantly reduced in the auditory nuclei and hippocampus but increased in the field L. Glial cell number was significantly increased in both experimental groups, being highest in the noise group. The brainstem auditory nuclei and field L showed an increase in glia to neuron ratio in the experimental groups as compared to control. In the hippocampus the ratio remained unaltered between control and music groups, but was higher in the noise group. It is thus evident that though the sound pressure level in both experimental groups was the same there were differential changes in the morphological parameters of the brain regions studied, indicating that the characteristics of the sound had a role in mediating these effects.

Identification of groupers based on pyloric caeca differentiation.

The examination of nine species of groupers present in south-east Indian waters has indicated that the pyloric caeca number, pattern and colouration are reliable and useful characters for identification. Three distinct morphotypes of pyloric caeca were observed in this study.

Ectopic supernumerary tooth on the inferior nasal concha.

Variations regarding the location of an ectopic tooth in the human nasal cavity, although rare, are documented in the literature, but presence of an ectopic tooth on the inferior nasal concha (INC) has not been reported. We observed an anomalous tooth projecting from the posterior margin of the right INC in two adult female skulls. A small quadrangular tooth projected beyond the posterior margin of the hard palate in one of the skulls and a medium sized conical tooth was observed in the other skull. The affected INC in both skulls were located more inferiorly compared to the opposite side and were in close approximation with the hard palate. No similar findings were noted on the contralateral side nor were there any associated congenital or iatrogenic deformity. The phylogenetic, ontogenetic, and clinical importance of this variant is described. Knowledge of such an anomaly is of paramount importance to otorhinolaryngologists, reconstructive and dental surgeons, and radiologists for identification of such rarities encountered during invasive or non-invasive procedures.

Unusual insertion of the coracobrachialis muscle to the brachial fascia associated with high division of brachial artery.

Anatomical variations of the coracobrachialis muscle (CBM) are common. We detected an abnormal form of the CBM of the left arm during human cadaver dissection. The CBM originated from the tip of the coracoid process of the scapula and divided into muscular and musculo-aponeurotic bellies. The muscular belly inserted into the middle of the anteromedial surface of the humerus, which is the normal anatomic insertion point of the CBM. The musculo-aponeurotic belly inserted into the medial intermuscular septum as well as the brachial fascia, creating a tunnel for the passage of the brachial artery. Inside the tunnel, the brachial artery bifurcated into the radial and ulnar arteries. No abnormality of the CBM, the brachial artery, or the median nerve was detected in the contralateral arm. The phylogenic, ontogenic, functional, and clinical importance of this variant muscle is described. Knowledge of such variations is of considerable importance during invasive and non-invasive investigative procedures or orthopedic, reconstructive, or surgical procedures.

Axillary vein perforation by the medial cutaneous nerve of the forearm.

Variation in the venous pattern in the arm is common. In this study, a rare variant of the axillary vein and its association with the median cutaneous nerve of the forearm is described. In the axilla, the medial cutaneous nerve of the forearm penetrated the axillary vein, thereby creating two narrow venous channels at the site of passage. Such variations are important because a large number of diagnostic and therapeutic invasive procedures are carried out on veins. A possible mode of origin and the clinical importance of this variation are discussed.

Median nerve penetration by a muscular branch of the brachial artery.

Arterial variations in the distal half of the arm are common (Anagnostopoulou and Venieratos 1999, J. Anat. 195:471-476). We observed a rare variant of a muscular branch of the brachial artery that penetrated the median nerve in the lower part of the arm. After its origin from the posteromedial surface of the brachial artery, the muscular branch passed through a nervous loop in the median nerve to enter and supply the brachialis muscle. At the site of arterial penetration, the nerve displayed perineurial thickening and increased fasciculation and interfascicular connective tissue. Three small branches of the artery supplied the nerve fascicles. We did not observe nerve compression or muscular changes, but the possibility of altered clinical symptoms produced by irritation from arterial pulsation cannot be ruled out. This variation may be clinically important because symptoms of median nerve compression arising from similar variations are often confused with more common causes, such as radiculopathy and carpal tunnel syndrome.

Variation in the origin of the inferior alveolar nerve.

The inferior alveolar nerve and maxillary artery were studied in 40 human heads through infratemporal dissection; in one specimen, a unusual variation in the origin of the inferior alveolar nerve and its relationship with the surrounding structures was observed. The inferior alveolar nerve originated from the mandibular nerve by two roots and the second part of the maxillary artery was incorporated between them. An embryologic origin of this variation and its clinical implications is discussed. Because the maxillary artery ran between the two roots of the inferior alveolar nerve, and the nerve was fixed between the foramen ovale and mandibular foramen, tension and compression of the nerve from arterial pulsation could cause mandibular neuralgia.

Anatomy of the cystic artery arising from the gastroduodenal artery and its choledochal branch--a case report.

Variations in the branching pattern of the common hepatic artery often occur and may be encountered during cholecystectomy. Variants of the cystic artery, its branches and relations with the biliary structures and blood vessels emphasise the importance of arterial dissection in biliary surgery. In this study, a rare variant of the cystic artery and its choledochal branch is described. The cystic artery arose from the gastroduodenal artery, passed anterior to structures in the free margin of lesser omentum and travelled a long distance before supplying the gall bladder. A long choledochal branch was noted accompanying the common bile duct. Surgical implications of this variation of the cystic and choledochal arteries are discussed.

Nicotine evokes cell death in embryonic rat brain during neurulation.

Maternal cigarette smoking during pregnancy represents the most prevalent exposure to a suspected neuroteratogen, nicotine. Although animal models have demonstrated brain cell loss and synaptic abnormalities after prenatal nicotine exposure, the multiple effects of nicotine on the maternal-fetal unit make it difficult to prove that nicotine itself is a neuroteratogen. In the current study, whole rat embryo culture was used to study the effects of nicotine at the neural tube stage of development. Beginning on embryonic day 9.5, embryos were exposed to 1, 10 or 100 microM nicotine. After 48 hr, embryos were examined for dysmorphogenesis and were then processed for light microscopic examination of the neuroepithelium. Examination of the forebrain, midbrain and hindbrain regions revealed extensive cytotoxicity, evidenced by cytoplasmic vacuolation, enlargement of intercellular spaces and a sharply increased incidence of pyknotic/apoptotic cells. These alterations were evident in the absence of generalized dysmorphogenesis and were detectable even at the lowest concentration of nicotine. At the highest concentration, abnormalities were present in the majority of cells. Superimposed on cell damage, we found an increase in mitotic figures. Although enhanced mitosis could represent partial compensation for cell loss, the regional selectivity and concentration dependence of the mitogenic effect differed significantly from that of cell death, suggesting separable mechanisms. The present results support the view that nicotine is a neuroteratogen, specifically targeting brain development at concentrations below the threshold for dysmorphogenesis.