Search PubMed⌕ Search

Biomedical subjects

S K Pandey

Publications and source records attributed to S K Pandey.

At least 19 recordsLinked to original sources
PubMed2007

Anatomical variations of the cords of brachial plexus and the median nerve.

The variations in formation, location, and courses of the cords of brachial plexus and the median nerve were studied in both axillae of 172 cadavers. The total prevalence of variation was 12.8% (CI, 7.6-17.4) and it was found in 13.2% (CI, 7.5-18) of male and in 10.7% (CI, -0.6-19.6) of female cadavers. These variations were divided into three groups. The first group was abnormal location of the cords, which was either posterolateral or anteromedial in relation to the axillary artery in 2.3% (CI, 0.1-4.5) cadavers. The lateral cord and the medial root of the median nerve had received communicating branches from the posterior cord in most of the cases of this group. The second group was absence of the posterior cord in 3.5% (CI, 0.7-6.1) of cadavers. The lateral and medial cords of this group were connected with the communicating branches, which had a course in front of the axillary artery. The third group was abnormal formation and course of the median nerve in 7% (CI, 3.1-10.6) of cadavers. In all cases of this group the medial root received communicating branch/branches either from the lateral or posterior cord. In eight (4.7%) cadavers, both roots of the median nerve were joined on medial side of the axillary artery to form a median nerve, which traveled medial to the artery. In four (2.3%) cadavers the roots of the median nerve did not join and both traveled separately anteromedial to the axillary and brachial arteries. This study indicates that all three cords and median nerve vary considerably in levels of origin, location and course in relation to the axillary artery and these variable cases were joined with the communicating branch/branches. The observed variations are of anatomical and clinical interest. These kinds of variations are more prone to injury in radical neck dissection and in other surgical operation of the axilla.

Aged↗
PubMed2006

Lithium stabilizes the polarized lens epithelial phenotype and inhibits proliferation, migration, and epithelial mesenchymal transition.

Posterior capsule opacification (PCO) is a common complication of cataract surgery caused by epithelial mesenchymal transition (EMT) and aberrant lens cell growth. One path to prevention depends on maintaining the quiescent lens epithelial phenotype. Here we report that lithium chloride (LiCl) is a potent stabilizer of the lens epithelial phenotype. In lens epithelial explants (controls), at low cell density, cells readily depolarized, spread out, and proliferated. By contrast, in the presence of LiCl, cells did not spread out or exhibit migratory behaviour. Using concentrations of 1-30 mM LiCl we also showed that cell proliferation is inhibited in a dose-dependent manner. Confocal microscopy and immunohistochemistry for ZO-1 and E-cadherin showed that LiCl treatment maintained tight junctions at the apical margins of cells. Taken together with measurements of cell heights, this showed that the cells in LiCl-treated explants maintained the apical baso-lateral polarity and cobblestone-like packing that is characteristic of lens epithelial cells in vivo. Significantly, the effects of LiCl also extended to blocking the potent EMT/cataract-promoting effects of transforming growth factor beta (TGFbeta) on lens epithelial cells. In TGFbeta-treated explants, cells progressively dissociated from one another, taking on various elongated spindle shapes and strongly expressing alpha-smooth muscle actin (alpha-SMA). These features are characteristic of PCO. In both rat and human capsulorhexis explants, LiCl treatment effectively blocked the accumulation of alpha-SMA and maintained the cells in a polarized, adherent, cobblestone-packed monolayer. These findings highlight the feasibility of applying molecular strategies to stabilize lens epithelial cells and prevent aberrant differentiation and growth that leads to cataract.

Actins↗
PubMed2005

Intraoperative explantation of two single-piece hydrophobic acrylic intraocular lenses due to surface deposits.

PURPOSE: To report clinical, pathological, and laboratory analyses of two cases of single-piece hydrophobic acrylic intraocular lenses (IOLs), which presented with significant surface deposits during implantation. METHODS: The lenses were implanted with the manufacturer's recommended injector (loaded with Viscoat and Healon GV, respectively). Immediately after injection into the anterior chamber, areas on the lenses' surfaces were covered by deposits, which could not be entirely removed by irrigation/aspiration. The lenses were explanted and replaced with lenses of the same design. They underwent gross analyses, light microscopy, scanning electron microscopy, and energy dispersive X-ray spectroscopy for analysis of the elemental composition of the deposits. Liquid chromatography/mass spectroscopy was also performed to identify the presence of proteins. RESULTS: The deposits on the first lens had a granular appearance, forming a homogeneous layer mostly on the posterior lens surface. Larger crystal-like deposits were present mostly on the anterior surface of the second lens. Elemental analyses of the deposits in both cases revealed the presence of peaks of sodium, chloride, phosphate, and potassium, in addition to the peaks of carbon and oxygen (normal constituents of the lens material). Only protein components normally found in the anterior chamber during surgery, such as haemoglobin and albumin, were identified. CONCLUSIONS: The results obtained suggest that the deposits in both cases may have resulted from crystallization of the ophthalmic viscosurgical device normally used during the loading of the IOLs into the cartridges.

Acrylic Resins↗
PubMed2005

Effect of Asparagus racemosus rhizome (Shatavari) on mammary gland and genital organs of pregnant rat.

Asparagus racemosus (AR) Willd (family Liliaceae) is commonly known as Shatavari. The alcoholic extract of its rhizome was administered orally to adult pregnant female albino rats at a dose of 30 mg/100 g body weight, daily for 15 days (days 1-15 of gestation). The macroscopic findings revealed a prominence of the mammary glands, a dilated vaginal opening and a transversely situated uterine horn in the treated group of animals. The weight of the uterine horns of the treated group was found to be significantly higher (p < 0.001) but the length was shorter (p > 0.01). Microscopic examination of the treated group showed proliferation in the lumen of the duct of mammary gland. It was obliterated due to hypertrophy of ductal and glandular cells. Hyperplasia of the glandular and muscular tissue and hypertrophy of the glandular cells were observed in the genital organs. The parenchyma of the genital organs showed abundant glycogen granules with dilated blood vessels and thickening of the epithelial lining. The oviduct in the treated group showed hypertrophied muscular wall, whereas the ovary revealed no effect of the drug. The results suggest an oestrogenic effect of Shatavari on the female mammary gland and genital organs.

Animals↗
PubMed2004

Anatomical variations of the splenic artery and its clinical implications.

The variations in orgin, course, and terminal branching pattern of the splenic artery were studied in 320 cadavers. The artery originated from the coeliac trunk in the majority of cadavers (90.6%), followed by abdominal aorta (8.1%), and other sights (1.3%). A suprapancreatic course of the artery was commonly observed (74.1%) followed by enteropancreatic (18.5%), intrapancreatic (4.6%), and retropancreatic (2.8%) courses. In two cases (0.63%) the proximal part of the splenic artery made a loop that was embedded in the substance of the pancreas, which is an interesting and rare finding. In five cases (1.5%) the proximal part of the artery divided into two or more branches that had suprapancreatic and enteropancreatic courses. The splenic artery divided into terminal branches in 311 (97%) cadavers. In nine (2.8%) cadavers it passed through the hilum of spleen without dividing. Two terminal branches were the most common (63.1%) followed by four (18.8%), six (9.7%), and more than six (5.6%) branches. The present study clearly indicates that there is variation in origin, course, and terminal distribution pattern of the splenic artery. The knowledge of these variations are of significant importance during surgical and radiological procedure of upper abdominal region to avoid any catastrophic complications.

Aorta, Abdominal↗
PubMed2004

Anatomical variations in termination of the axillary artery and its clinical implications.

Variations in the termination of the axillary artery (AA) were observed in 51 out of 356 axilla during routine dissections. The incidence of variation was higher on the right axilla in 17.42% cases (CI: 11.60-22.51) than the left axilla 11.24% cases (CI: 6.46-15.55) and was found to be 12.33% in male and 40.63% in female cadavers. The variations were divided into four groups. The first group showed that the terminal end of the AA divided into lateral and medial divisions in 6.16% (CI: 2.21-9.82) male and in 15.63% (CI: 2.76-25.25) female cadavers. The second group variation showed that the terminal end of the axillary artery divided into deep and superficial divisions in 2.74% (CI: 0.10-5.27) male and in 6.25% (CI: -1.87-13.13) female cadavers. The third group showed that the terminal end of the AA divided into three branches in 2.74% (CI: 0.10-5.27) male and in 6.25% (CI: -1.87-13.13) female cadavers. The fourth group showed the tapering of the terminal end of AA in 0.68% (CI: -0.63-1.99) male and 12.50% (CI: 0.97-21.46) female cadavers. The variable origin of the circumflex humeral, subscapular and profunda brachii arteries was also observed. These variations in the terminal end of the axillary artery are not only of significant clinical importance to orthopaedic and reconstructive surgeons but also have very significant medico-legal implications.

Axilla↗
PubMed2003

Calcification of modern foldable hydrogel intraocular lens designs.

PURPOSE: To report and compare clinical and pathological features of hydrophilic acrylic intraocular lenses (IOLs) of three major designs, explanted from patients who had visual disturbances caused by opacification of the lens optic. METHODS: Eighty-seven hydrophilic acrylic IOLs (25 Hydroview, 54 SC60B-OUV, and 8 Aqua-Sense lenses) were explanted and sent to our center. Most patients became symptomatic during the second year after cataract surgery. A fine granularity was observed on the surface of the lens optic in the case of Hydroview. With the SC60B-OUV and Aqua-Sense lenses, the opacity resembled a nuclear cataract. Gross examination, light microscopy and staining with alizarin red and the von Kossa method (for calcium) were performed. Some lenses were submitted for scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS). RESULTS: Light microscopic and SEM analyses revealed the presence of irregular granular deposits on the external optical surfaces of Hydroview lenses. With the SC60B-OUV lenses, the opacity was caused by the presence of multiple fine, granular deposits within the lens optic, distributed in a line parallel to the anterior and posterior curvatures of the optic, with a clear zone just beneath its external surfaces. The Aqua-Sense lenses exhibited both patterns simultaneously. The deposits in all cases stained positive with alizarin red and von Kossa method. EDS also demonstrated the presence of calcium and phosphates within the deposits. CONCLUSION: Differences in the water content of the hydrophilic acrylic materials used in the manufacture of these three lens designs may be responsible for the different patterns of calcium precipitation. Careful clinical follow up of patients implanted with these lenses is necessary to determine if this phenomenon is rare and sporadic or may be more widespread.

Aged↗
PubMed2003

Paediatric cataract blindness in the developing world: surgical techniques and intraocular lenses in the new millennium.

Paediatric cataract blindness presents an enormous problem to developing countries in terms of human morbidity, economic loss, and social burden. Managing cataracts in children remains a challenge: treatment is often difficult, tedious, and requires a dedicated team effort. To assure the best long term outcome for cataract blind children, appropriate paediatric surgical techniques need to be defined and adopted by ophthalmic surgeons of developing countries. The high cost of operative equipment and the uneven world distribution of ophthalmologists, paediatricians, and anaesthetists create unique challenges. This review focuses on issues related to paediatric cataract management that are appropriate and suitable for ophthalmic surgeons in the developing world. Practical guidelines and recommendations have also been provided for ophthalmic surgeons and health planners dealing with childhood cataract management in the developing world.

Accommodation, Ocular↗
PubMed2003

[Techniques for preparing postmortem human eyes to perform anterior segment intraocular surgery].

We describe different methods to prepare postmortem human or animal eyes used at the Center for Research in Ocular Therapeutics and Biodevices at the Storm Eye Institute, Medical University of South Carolina, Charleston, SC, USA. These techniques have been utilized for performing different surgical procedures (phacoemulsification, extracapsular cataract extraction, etc.), and for training of surgeons in-transition. Performing these techniques in the wet-laboratory contributed to improve surgical skills to perform the critical steps of the phacoemulsification surgery. Pathological evaluation of pseudophakic postmortem human eyes using the Miyake-Apple posterior view and histology was helpful to analyze postoperative complications of cataract surgery (anterior capsule opacification and posterior capsule opacification) secondary to postoperative proliferation of lens epithelial cells into the capsular bag. Modifications in the surgical techniques and/or lens design may be helpful to reduce these postoperative complications. Implantation of various aphakic and phakic intraocular lenses in postmortem human eyes as well as animal eyes was helpful to analyze the sizing and fitting of new lens designs within the eye.

Animals↗
PubMed2002

Studies on essential oils: part 10; antibacterial activity of volatile oils of some spices.

The essential oils extracted from the seeds of seven spices, Anethum graveolens, Carum capticum, Coriandrum sativum, Cuminum cyminum, Foeniculum vulgare, Pimpinella anisum and Seseli indicum have been studied for antibacterial activity against eight pathogenic bacteria, causing infections in the human body. It has been found that the oil of C. capticum is very effective against all tested bacteria. The oil of C. cyminum and A. graveolens also gave similar results. These oils are equally or more effective when compared with standard antibiotics, at a very low concentration.

Anethum graveolens↗
PubMed2002

Post cataract-intraocular lens (IOL) surgery opacification.

Intraocular lens (IOL) implantation has no doubt been one of the most satisfying advances of medicine. Millions of individuals with visual disability or frank blindness from cataracts had and continue to have benefit from this procedure. It has been reported by ophthalmologists that the modern cataract-intraocular lens (IOL) surgery is safe and complication-free most of the time. This makes the watchword for any cataract surgeon to be 'implantation,' 'implantation,' 'implantation.' In the mid-1980s, as IOLs were evolving rapidly, the watchword of the implant surgeon was 'fixation,' 'fixation,' 'fixation.' Most techniques, lenses and surgical adjuncts now allow us to achieve the basic requirement for successful IOL implantation, namely long-term stable IOL fixation in the capsular bag. However despite this advancement some items 'slipped through cracks.' In this article, we would like to alert the reader to a new watchword, namely 'opacification,' 'opacification,' 'opacification.' Here we will be talking about the good, the bad, and the ugly. Examples of the 'good' include the recent successes now being achieved in reducing the incidence of posterior capsule opacification. Examples of the 'bad' include various proliferations of anterior capsule cells, problems caused by silicone oil adherence to IOLs and problems with piggyback IOLs. The 'ugly' include the sometimes striking and often visually disabling opacifications occurring on and within IOL optics, both on some modern foldable IOLs as well as a poly(methyl methacrylate) (PMMA) optic degradation occurring with some models a decade or more after implantation.

Cataract↗
PubMed2001

Constitutively active Akt is an important regulator of TRAIL sensitivity in prostate cancer.

TRAIL/Apo-2L is a member of the tumor necrosis factor superfamily and has recently been shown to induce apoptosis in cancer cells, but not in normal cells. In nude mice injected with human tumors, TRAIL reduces the size of these tumors without side effects. Akt promotes cell survival and block apoptosis. Some prostate cancer cells express high levels of Akt due to lack of active lipid phosphatase PTEN, a negative regulator of PI-3 kinase pathway, which may be responsible for drug resistance. The objective of this paper is to investigate the intracellular molecules that regulate TRAIL resistance. We have examined caspase-8 activity, BID cleavage, Akt activity, mitochondrial membrane potential (DeltaPsi(m)) and apoptosis in prostate cancer (LNCap, PC-3, PC-3M and DU145) cells treated with or without TRAIL. PC-3, PC-3M and DU145 cells are sensitive to TRAIL, whereas LNCap cells are resistant. LNCap cells express the highest level of constitutively active Akt, which is directly correlated with TRAIL resistance. TRAIL activates caspase-8 in all the cell lines. Downregulation of constitutively active Akt by PI-3 kinase inhibitors (wortmannin and LY-294002), dominant negative Akt or PTEN, renders LNCap cells sensitive to TRAIL. Inhibition of TRAIL sensitivity occurs at the level of BID cleavage. Inhibition of protein synthesis by cycloheximide also causes LNCap cells sensitive to TRAIL. Overexpression of Bcl-2 or Bcl-X(L) inhibits TRAIL-induced DeltaPsi(m) and apoptosis. Overexpression of constitutively active Akt in PC-3M cells (express very low levels of constitutively active Akt) restores TRAIL resistance. These data suggest that elevated Akt activity protects LNCap cells from TRAIL-induced apoptosis, and the PI-3 kinase/Akt pathway may inhibit apoptotic signals by inhibiting processing of BID. Thus, constitutively active Akt is an important regulator of TRAIL sensitivity in prostate cancer.

Androstadienes↗
PubMed2001

Pro-survival function of Akt/protein kinase B in prostate cancer cells. Relationship with TRAIL resistance.

Tumor necrosis factor superfamily member TRAIL/Apo-2L has recently been shown to induce apoptosis in transformed and cancer cells. Some prostate cancer cells express constitutively active Akt/protein kinase B due to a complete loss of lipid phosphatase PTEN gene, a negative regulator of phosphatidylinositol 3-kinase pathway. Constitutively active Akt promotes cellular survival and resistance to chemotherapy and radiation. We have recently noticed that some human prostate cancer cells are resistant to TRAIL. We therefore examined the intracellular mechanisms of cellular resistance to TRAIL. The cell lines expressing the highest level of constitutively active Akt were more resistant to undergo apoptosis by TRAIL than those expressing the lowest level. Down-regulation of constitutively active Akt by phosphatidylinositol 3-kinase inhibitors, wortmannin and LY294002, reversed cellular resistance to TRAIL. Treatment of resistant cells with cycloheximide (a protein synthesis inhibitor) rendered cells sensitive to TRAIL. Transfecting dominant negative Akt decreased Akt activity and increased TRAIL-induced apoptosis in cells with high Akt activity. Conversely, transfecting constitutively active Akt into cells with low Akt activity increased Akt activity and attenuated TRAIL-induced apoptosis. Inhibition of TRAIL sensitivity occurs at the level of BID cleavage, as caspase-8 activity was not affected. Enforced expression of anti-apoptotic protein Bcl-2 or Bcl-X(L) inhibited TRAIL-induced mitochondrial dysfunction and apoptosis. We therefore identify Akt as a constitutively active kinase that promotes survival of prostate cancer cells and demonstrate that modulation of Akt activity, by pharmacological or genetic approaches, alters the cellular responsiveness to TRAIL. Thus, TRAIL in combination with agents that down-regulate Akt activity can be used to treat prostate cancer.

Androstadienes↗
PubMed2001

[Complication profiles of posterior chamber intraocular lenses IOL). An analysis of 586 foldable and 2077 rigid explanted intraocular lenses].

BACKGROUND: Foldable intraocular lenses (IOL) have become increasingly preferred choice for IOL implantation after cataract removal. However, both foldable as well as rigid IOLs are not yet complication-free and may need explanation. MATERIAL AND METHODS: A total of 2663 explanted posterior chamber IOLs (PCIOLs) were accessioned at the Center for Research on Ocular Therapeutics and Biodevices between January 1988 and September 2000. The lenses were examined grossly using a Leitz/Wild M-8-Zoom stereomicroscope. The clinical reasons for explanation were documented for foldable as well as for rigid lenses. RESULTS: Of a total of 2663 explanted PCIOLs, 586 were foldable lenses and 2077 were rigid PMMA lenses The most frequent reason for explantation of all 2663 IOLs studied was decentration/dislocation. Optic and haptic damage and posterior capsule rupture were significantly more often a reason for explantation in several foldable designs compared to rigid PCIOLs. Whereas rigid designs lead more often to corneal decompensation. The percentage of explanted IOLs because of inflammatory reactions decreased significantly from 1994 to 2000. CONCLUSIONS: The complication profiles of rigid and foldable IOLs revealed some apparent differences due to the nature of the IOL biomaterials and designs. IOL optic/haptic damage was a common complication for foldable IOLs, whereas it was only discovered in single digits for rigid PMMA IOLs. The possible explanation for this is, that the soft and flexible biomaterials, from which all the foldable IOLs were manufactured, are easier to be damaged during folding, unfolding and insertion procedure. In our opinion this relative disadvantage of foldable IOLs is by far outweighed by the numerous advantages of the small incision cataract surgery. The decreasing inflammatory reactions can be explained by advances in surgical techniques, especially the secure in-the-bag fixation of IOLs.

Humans↗
PubMed2001

[Morphological autopsy findings in human eyes implanted with Ridley intraocular lenses].

BACKGROUND: Sir Harold Ridley's first cataract extraction with implantation of an intraocular lens (IOL) marked the beginning of a major change in the practice of ophthalmology. MATERIAL AND METHODS: Two human autopsy globes implanted with original Ridley IOLs were grossly examined from behind with the Miyake-Apple photographic technique. The anterior segments were evaluated histologically. One Ridley IOL was examined by scanning electron microscopy. RESULTS: Both IOLs maintained a clear visual axis and had been placed in the capsular sac. The right lens was decentered inferiorly, the left IOL was well centered. The posterior capsule showed only minimal capsular opacification. Scanning electron microscopy (SEM) of the explanted IOL showed a smooth, well polished surface. CONCLUSIONS: In this patient Ridley IOLs maintained an ideal visual rehabilitation of 20/20 in both eyes, 22 and 18 years postoperatively. One surprising finding was the presence of a square, truncated optic edge geometry, very similar to that seen in some modern foldable IOLs. In our opinion the absence of posterior capsule opacification of the Ridley IOL may have partially been a result of this nearly sharp optic edge, that we confirmed by SEM. Even 22 years after implantation the Ridley IOL showed a high finish quality. Many of Sir Harold Ridley's early concepts like the IOL placement in the posterior chamber and endocapsular implantation are now the standard of modern cataract surgery.

Aged↗