Variant communication of phrenic nerve in neck.

PURPOSE: Variations of the phrenic nerve gain importance in the context of subclavian vein cannulation, implanted venous access portals and supraclavicular nerve block for regional anaesthesia. Some of the variations of phrenic nerve are very common and may have implications even while performing very simple and routine procedures. METHODS: During routine dissection in the Department of Anatomy, an anatomical variation was observed in the course of the phrenic nerve in an adult male cadaver. RESULTS: On the right side, phrenic nerve in its early course in the neck, close to its origin was giving a communicating branch to the upper trunk of the brachial plexus. Further course of the phrenic nerve was typical. On the left side, no such communication between phrenic nerve and brachial plexus was observed. CONCLUSIONS: A thorough knowledge of the anatomical variations and standard anatomy of phrenic nerve is a necessity for the safe and efficient practice of regional anaesthesia.

An anatomical study of the pterygospinous bar and foramen of Civinini.

PURPOSE: The pterygospinous ligament extends from the posterior free margin of the lateral pterygoid plate till the spine of the sphenoid. The ligament may ossify partly or completely leading to the formation of the pterygospinous bar. A complete ossification of the ligament results in the formation of the foramen of Civinini. Presence of the complete or incomplete pterygospinous bar may lead to a difficulty in passing the needle during anaesthesia for the trigeminal neuralgia or the bar may also compress the mandibular nerve and its branches to cause lingual numbness, pain and speech impairment. METHOD: Presence of the complete or incomplete pterygospinous bar and the foramen of Civinini were studied in 55 dried adult skulls and 20 sphenoid bones. RESULTS: Partial or complete ossification of the pterygospinous ligament was seen in 17.33 % skulls. One skull showed the presence of bilateral complete pterygospinous bar while another skull had the unilateral complete pterygospinous bar on right side. Two skulls and one sphenoid had bilateral incomplete pterygospinous bar while seven skulls and one sphenoid bone had unilateral incomplete pterygospinous bar. In three cases, the bar was passing just below the foramen ovale. CONCLUSION: The pterygospinous bar when present medial to the foramen ovale may not have much clinical significance but when the bar is present just below the foramen ovale, it may cause a compression of the mandibular nerve and its branches and may also obstruct the passage for the transoval approach to the neighbouring regions.

Genes involved in stress response and alcohol use among high-risk African American youth.

BACKGROUND: Genetic and environmental factors influence substance use behaviors in youth. One of the known environmental risk factors is exposure to life stressors. The aim of this project is to study the interaction between NR3C1 and CRHBP, genes thought to be involved in stress pathways, exposure to stressful life events, and adolescent alcohol use/misuse. METHODS: The sample included 541 African American individuals (ages 13-18) from the Genes, Environment, and Neighborhood Initiative, a subset of the Mobile Youth Survey sample from whom DNA and more extensive phenotypic data were collected. Participants were selected from high-poverty neighborhoods in Mobile, Alabama, with potential exposure to a variety of extreme life stressors. RESULTS: A measure of stressful life events was significantly predictive of alcohol use/misuse. In addition, this association was significantly dependent upon the number of putative risk variants at rs1715749, a single-nucleotide polymorphism (SNP) in CRHBP (P ≤ .006). There was no significant interaction between NR3C1 and stressful life events with respect to alcohol use/misuse, after taking into account multiple testing. CONCLUSIONS: These findings suggest that CRHBP variants are potentially relevant for adolescent alcohol use/misuse among African American youth populations being reared within the context of stressful life events and warrant replication.

Spit for Science: launching a longitudinal study of genetic and environmental influences on substance use and emotional health at a large US university.

Finding genes involved in complex behavioral outcomes, and understanding the pathways by which they confer risk, is a challenging task, necessitating large samples that are phenotypically well characterized across time. We describe an effort to create a university-wide research project aimed at understanding how genes and environments impact alcohol use and related substance use and mental health outcomes across time in college students. Nearly 70% of the incoming freshman class (N = 2715) completed on-line surveys, with 80% of the students from the fall completing spring follow-ups. 98% of eligible participants also gave DNA. The participants closely approximated the university population in terms of gender and racial/ethnic composition. Here we provide initial results on alcohol use outcomes from the first wave of the sample, as well as associated predictor variables. We discuss the potential for this kind of research to advance our understanding of genetic and environment influences on substance use and mental health outcomes.

Ansa cervicalis - variable course of the superior root

In the past few years, techniques have been developed using ansa cervicalis to innervate muscles of the larynx paralyzed due to surgical procedures performed in the area of the chest and neck. In the present report, during routine dissection in a middle-aged male cadaver, we observed an unusual course of the superior root of the ansa cervicalis on right side. The superior root of the ansa cervicalis fused with the vagus, and ran within the carotid sheath before joining the inferior root forming the ansa cervicalis in the anterior wall of the carotid sheath. The present case should add to our existing knowledge of ansa cervicalis, and should help surgeons in avoiding injury to the nerve during various surgical procedures

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Computerized morphometric analysis of human femoral articular cartilage.

Objective. Articular cartilage shows changes with age that are considered to be the most important factors in the development and progression of osteoarthritis. The studies on age changes in articular cartilage have been traditionally based on individual observations but this approach is limited by its subjectivity and bias, yielding considerable variability. So the present study was conducted to observe various age related changes in morphology of femoral articular cartilage using computerized morphometric analysis. Design. The articular cartilage specimens were divided into two groups according to age: group 1 (n = 16) below 40 years (16-40 years) and group 2 (n = 12) above 40 years (41-86 years) of age. 5 µm thick paraffin sections were stained with H&E and analyzed using Image Pro Express image analysis software for quantitative analysis of articular cartilage. Various parameters, that is, total thickness of the cartilage, area of lacunae in each zone, area of subchondral cavities, and number of chondrocytes per 10,000 µm(2) area in each zone were measured. Results. Significant difference with age was found in the total thickness and area of lacunae in zone 3. Conclusions. Not much difference is observed in articular cartilage morphology with age. So ageing is not the only risk factor in development of osteoarthritis.

Immunohistochemical analysis of ageing and osteoarthritic articular cartilage.

Articular cartilage degeneration seen in osteoarthritis is primarily the consequence of events within the articular cartilage that leads to the production of proteases by chondrocytes. 22 osteoarthritic cartilage specimens were obtained from patients with primary osteoarthritis (46-81 years) undergoing total knee replacement. 12 age-matched (41-86 years) and 16 young (16-40 years) non-osteoarthritic control cartilage specimens were obtained from the cadavers in the department of Anatomy and from patients undergoing lower limb amputation in Trauma center of PGIMER, Chandigarh. 5 µ thick paraffin sections were stained for osteocalcin, osteopontin, osteonectin and alkaline phosphatase to analyze their expression in hypertrophied chondrocytes and osteoarthritic cartilage matrix and to compare the staining intensity with that of normal ageing articular cartilage. Immunohistochemical staining of tissue sections revealed moderate to strong cytoplasmic staining for all four stains in all the specimens of the osteoarthritic group compared to age-matched control. The immunohistochemical scores were significantly higher in the osteoarthritic group for all four stains. The features of the osteoarthritic articular cartilage were markedly different from the non-osteoarthritic age-matched articular cartilage suggesting that osteoarthritis is not an inevitable feature of aging.

Horseshoe kidney--a case report.

The congenital anomalies of kidney are important as they may cause renal failure in middle age group. Horseshoe kidney is the most common fusion anomaly. It has been said to occur in every 400 births and is seen in approximately 1 out of 300 pyelographies. A horseshoe kidney was observed in a thirty-two year old male in the archives of the Department of Anatomy, PGIMER, Chandigarh. The kidney was placed at lower level as compared to its normal position. The lower poles were fused to form the isthmus opposite to the L4 vertebra. There was no extra renal anomaly. Relation of structures in hilum was normal on right side while on left side pelvis was anterior to vein and artery. The right and left renal arteries arose as usual as lateral branches of the aorta just below the level of superior mesenteric artery. Two accessory renal arteries originated from the ventral aspect of aorta just above the isthmus. Right kidney was drained by three renal veins directly into the inferior vena cava while the left kidney was drained by a renal vein which had three tributaries outside the hilum. The right kidney appeared normal under the light microscope while in the left kidney, glomeruli were decreased and glomerular space appeared more. Some of the glomeruli appeared atrophied and filled with eosinophilic material. The horseshoe kidney has been estimated to be occurring in 0.25% of the general population and is more common in men.

Osteoarthritic femoral articular cartilage of knee joint in man.

Osteoarthritis is the most common of the various articular disorders affecting man. The present study was conducted to observe the microstructure of osteoarthritic human femoral articular cartilage by light microscopy. Fifteen osteoarthritic cartilage specimens obtained from patients with primary osteoarthritis (52-80 years) undergoing total knee replacement were processed for paraffin sections. 5 m thick sections were observed under light microscope. The articular surface appeared to be very irregular and fibrillated in all the specimens. The cartilage did not show the normal zonation. Various changes seen were different in all specimens and they were not related to age. Most common feature of the osteoarthritic articular cartilage was the presence of large clusters of cells in 60.0% specimens. Detached parts of the degenerating cartilage were present in the joint cavity in the form of loose bodies. The collagen fibres appeared to be coarser and irregular even near the non-fibrillated areas. Numerous tangential, oblique and vertical splits were also observed. Osteoblastic and osteoclastic activity was seen in the subchondral bone and the osteolytic cyst appeared to invade the cartilage from the subchondral bone. Blood vessels from the subchondral bone were also seen invading the cartilage in 20.0% specimens. The various changes seen in the osteoarthritic cartilage could be an effort of cartilage repair but such attempts are severely counteracted by the osteoarthritic wear process.

Bilateral variant origin of pectoralis major.

The variable origin of muscles is not uncommon though the complete or partial absence of the clavicular head of pectoralis major muscle is rare. This paper deals with bilateral partial absence of clavicular head of pectoralis major muscle. The clavicular head was arising only in the middle of medial half of the clavicle and was separated from sternocostal head by a gap of 2.5cm and laterally from the origin of deltoid from clavicle by a gap of 2.5cm. Nerve supply of this muscle was from lateral and medial pectoral nerves as usual. The partial absence of the clavicular head of pectoralis major muscle becomes important in cases of reconstructive surgery as this head is required to cover the lateral acromioclavicular defect and in cases of established facial paralysis.

Disposition of muscularis propria and nerve elements in the lip of the ileocaecal valve.

The presence of a valve and the concept of a functional sphincter at the ileocaecal junction have been debated in the literature. Twenty four specimens of ileocaecal organ complex including 10cm of ileum and colon were obtained from cadavers from the Departments of Anatomy and Pathology, PGIMER, Chandigarh. 5 micron thick longitudinal sections from the upper lip of the ileocaecal valve were stained with Hematoxylin and Eosin and Silver stain. Sections of the ileum and colon from 5 ileocaecal organ complexes were also prepared and similarly stained. All the sections were viewed under the light microscope. The muscle bundles constituting the muscularis propria in the ileocaecal valve were arranged in two rows and were tapering in size from the base to the apex. The disposition of the muscle fibres was not uniform in all the specimens. The muscle fibers could be traced up to the upper, middle and lower third of the valve in 8 (33.3%), 14 (58.3%) and 2 (8.3%) specimens respectively. Silver stain of these sections revealed large numbers of nerve elements distributed within the submucosa and muscularis propria. The density of nerve elements in the ileocaecal valve was similar in all the sections irrespective of the extent of the muscularis propria and was comparable to the density of nerve elements in the muscularis propria and submucosa of the ileum and colon. The present study shows that the ileocaecal valve has a well developed muscularis mucosa and a proportionate component of the nerve elements.

Bilaterally anomalous formation and distribution of posterior cord of brachial plexus.

Posterior cord (PC) is formed by the union of posterior divisions of upper, middle and lower trunks. During routine dissection variations in the formation and distribution of PC and its branches were observed on both the sides. These variations were: i) prefixed brachial plexus on left side ii) PC on both the sides was formed by the union of posterior divisions of only the upper (C5, 6) and middle (C7) trunks while the posterior division of lower (C8, T1) trunk joined the radial nerve directly and also gave contribution by two roots to left thoracodorsal nerve iii) length of PC varied on both the sides; on right side it was 4cm while on left side it was 1.5cm long. iv) upper subscapular nerve on right side arose from PC far proximal to other branches and on its course communicated with lower subscapular nerve before distributing to subscapularis while on left side it arose from posterior division of the upper trunk (C5, 6) only. v) on left side nerve to teres minor arose directly from axillary nerve trunk instead of arising from its posterior branch. The axillary nerve on both the sides divided into terminal branches before entering the quadrangular space of arm instead after traversing the quadrangular space. vi) the branches of radial nerve, which normally arise in the radial groove, arose in the axilla on both the sides. So in cases of trauma or injury of arm some of these branches may be spared.