Morphology of saphenous nerve in cadavers: a guide to saphenous block and surgical interventions.

The knowledge about detailed morphology and relation of saphenous nerve is important to obtain successful saphenous nerve regional blocks to achieve pre- and post-operative anesthesia and analgesia, nerve entrapment treatments and to avoid damage of saphenous nerve during knee and ankle surgeries. The literature describing detailed morphology of saphenous nerve is very limited. We dissected 42 formalin fixed well embalmed cadaveric lower limbs to explore detailed anatomy, relation and mode of termination of saphenous nerve and measured the distances from the nearby palpable bony landmarks. The average distance of origin of saphenous nerve from inguinal crease was 7.89±1.42 cm, the distance from upper end of medial border of patella to saphenous nerve at that level was 8.11±0.85 cm, distance from tibial tuberosity was 7.53±0.98 cm and from midpoint of anterior border of medial malleolus was 0.45±0.14 cm. Saphenous nerve provided two infrapatellar branches at the level of mid to lower limit of patellar ligament in 90% cases. It was in close contact or adhered to great saphenous vein across the lower 2/3rd of leg lying either anterior, posterior or deep to the vein. The saphenous nerve terminated by bifurcating proximal to medial malleolus in majority of cases though no obvious bifurcation was observed in 9.52% cases. The detailed morphology, relations and the distances from palpable bony landmarks may be helpful for clinicians to achieve successful saphenous nerve block and to avoid saphenous nerve damage and related complications during orthopedic procedures.

Cadaveric Measurements of the Left Recurrent Laryngeal Nerve, Ligamentum Arteriosum, Aortic Arch, and Pulmonary Artery in the Thorax with Clinical Implications and Comparison Between Two Sexes in the American Population.

The left recurrent laryngeal nerve (RLN) is prone to get compressed or damaged, leading to vocal cord palsy, due to pathologies or surgeries of the structures closely surrounding this nerve in the thorax, including the esophagus, aortic arch, pulmonary trunk, and ligamentum arteriosum. We wanted to provide a data set including nerve diameter, its distance from the esophagus, measurements of the pulmonary artery, aorta, and ligamentum arteriosum in close proximity of the nerve in a healthy population to avoid its damage during surgery and predict its chances of compression during the diseased condition. We measured the left RLN and the surrounding structures in 39 well-embalmed cadavers. We compared the values among the male and female cadavers. We found that the mean diameter of the left RLN was 1.75 mm, the mean distance of the nerve from esophagus was 9.88 mm, the mean diameters of the aortic arch and pulmonary artery just distal to the attachment of the ligamentum arteriosum were 26.14 and 19.93 mm, respectively, and the length and width of ligamentum arteriosum were 15.89 and 2.79 mm, respectively. No clinically significant differences were found between male and female parameters. This set of values might be useful while investigating the cause of vocal cord palsies or during surgeries in close proximity to left RLN to avoid its damage.

A cadaveric study of ovarian veins: variations, measurements and clinical significance.

The literature showing information regarding ovarian venous variation, its diameter and termination distance from respective renal venous origin are limited. This information is important in various surgical and clinical procedures including venous embolization, vascular reconstruction during renal transplantation and localizing the source of origin of a pelvic mass. We examined 94 sides of 47 formalin fixed female cadavers and noted the course and termination of ovarian veins. We measured the diameter of ovarian veins at their termination point and the termination distance in respect to the termination point of renal veins at inferior vena cava (IVC) on respective sides. We found two cases of variations related to right ovarian vein -one, right ovarian vein joined the right renal vein; two, right ovarian vein duplicated and joined with IVC at two different points. We found one case of variation related to left ovarian vein-a partially duplicated left ovarian vein. All the variations were unilateral. The mean diameters of right and left ovarian veins were 3.66±1.18 and 4.20±0.96 mm, respectively. The distance of termination of ovarian veins ranged from 19-40 mm and 13-41 mm, respectively from termination points of right and left renal veins at IVC on respective sides. Our study presents a set of data regarding variation of ovarian veins, diameters and termination distances which could be useful for gynecologists, surgeons and radiologists.

Molecular Inclusion Complexes of ß-Cyclodextrin Derivatives Enhance Aqueous Solubility and Cellular Internalization of Paclitaxel: Preformulation and In vitro Assessments.

Drugs with low aqueous solubility and permeability possess substantial challenges in designing effective and safe formulations. Synergistic solubility and permeability enhancement in a simple formulation can increase bioavailability and efficacy of such drugs. To overcome limitations of the clinical formulation of Taxol®, Paclitaxel (PTX) was reformulated with various ß-cyclodextrin (CD) derivatives suitable for parenteral administration. Results indicated that ß-CDs can efficiently form complexes with PTX at lower molar ratios, enhance aqueous solubility up to 500 times and improved cellular internalization of PTX. All ß-CD derivatives were found to be safe as excipient since none showed detectable signs of cyto-genotoxicity. As a result, the CD-PTX complexes significantly increased the cytotoxicity of the drug. The study concluded that CD-PTX formulations could substitute the current intravenous infusion of PTX obviating the use of non-inert excipient Cremophor EL.

Lecture classes in human anatomy: the students' perceptions.

INTRODUCTION: The human anatomy, or in brief, the body structure has fascinated man for ages. Due to the information explosion and the increase in specializations, this knowledge is available in a very sketchy manner in high school biology courses. The first comprehensive course on the human anatomy is taught to the first year medical students in medical colleges. This is in keeping with the regulations of the Medical Council of India. The anatomy lecture classes occupy a considerable time of the course, to provide the students with an effective knowledge of the gross anatomy, histology, embryology and the clinical anatomy. On the other hand, the students' feedback regarding the lecture methods and the teaching environment is crucial in judging the efficacy of the present curriculum. OBJECTIVE: To obtain the students' feedback about the environment of the lecture classes, as regards the venue, the teaching and learning aids which are used, the lecture class schedule of the university (the number of classes per week, the durations of the lecture classes, etc.) and the existing departmental practices (display of the class routine in advance, synchronization between the lecture and the practical classes), so that their suggestions could help the faculty in planning the most effective teaching procedures. METHODS: A semi structured questionnaire was supplied to the students to get their feedback. RESULT: Most of the students found the air conditioned seminar room's environment to be more comfortable and they supported the existing durations of the lecture hours with the combined use of chalk and a board and overhead projectors (OHPs). CONCLUSION: The perceptions of the learners helped in modifying the departmental practice in the desired way.

Inhibition of human phenol and estrogen sulfotransferase by certain non-steroidal anti-inflammatory agents.

We hypothesized that aryl acetate- and aryl carboxylate-containing drugs would inhibit human phenol sulfotransferase (SULT1A1), and that selectivity would depend upon the interaction of the aryl portion of the molecule with the sulfotransferase acceptor binding site. This hypothesis was based on results with the rat orthologue showing that oxidation of phenolic substrates to carboxylate derivatives resulted in competitive inhibition of rat phenol sulfotransferase. We chose nine structurally representative non-steroidal anti-inflammatory agents and determined their inhibitory potency and selectivity toward SULT1A1 and expressed human estrogen sulfotransferase (SULT1E1). The results show that the tested agents reversibly inhibit SULT1A1 activity with IC(50) ranging from 0.1 microM to 3800 microM. These agents also inhibited SULT1E1 (IC(50) = 6 microM to 9000 microM). The agents were clearly isoform selective, with IC(50) ratios (1E1/1A1) ranging from 0.01 to 200. Nimesulide, meclofenamate, and piroxicam were more selective towards SULT1A1 inhibition, while sulindac and ibuprofen were more selective towards SULT1E1 inhibition. Sulfotransferase inhibition was maintained after substituting the carboxylate with enolate (nimesulide) or methylsulfonamide (piroxicam). Kinetic studies determined the type of inhibition of SULT1A1 for three agents (meclofenamate, nimesulide, aspirin) to be non-competitive or partial non-competitive versus both substrate (p-nitrophenol) and cofactor (PAPS). This inhibition mechanism indicates that meclofenamate, nimesulide and aspirin bind near enough to the substrate binding site to prevent catalysis but not affect dissociation of the substrate-enzyme complex. The inhibition of SULT1A1 by meclofenamate, nimesulide, salicylate and aspirin may be clinically relevant based on ratio of inhibition constant to predicted in vivo inhibitor concentration ([I]/IC(50) > 1).

Effect of combined use of nonionic surfactant on formation of oil-in-water microemulsions.

PURPOSE: This study evaluated the effects of combined use of two nonionic surfactants on the characteristics (i.e., appearance, emulsification time, and particle size) of oil-in-water microemulsions generated from flurbiprofen-loaded preconcentrates. METHODS: Three phase diagrams were constructed using Capmul PG8 (propylene glycol monocaprylate) as the oil, Tween 20 (polysorbate 20) and/or Cremophor EL (polyoxyl 35 castor oil) as surfactants. A number of preconcentrates were selected based on phase diagrams: O20T80 (20% Capmul PG8, 80% Tween 20), O20C80 (20% Capmul PG8, 80% Cremophor EL), O20T40C40 (20% Capmul PG8, 40% Tween 20, 40% Cremophor EL). Flurbiprofen loading in preconcentrates was tested at 0%, 1%, 2.5%, and 5% (w/w). The resulting mixtures of these preconcentrates upon dilution 100-fold with aqueous medium were characterized by visual and microscopic observation, HPLC and photon correlation spectroscopy. RESULTS: (a) For preconcentrates using single surfactant, either O20T80 or O20C80, the dilution generated emulsions with visible cloudiness. The particle size increased as the drug loading increased; (b) for preconcentrates using two surfactants O20T40C40, the dilution generated clear microemulsions with small particle sizes (10-11nm), and the increased drug loading seemed to have little effect on the particle size. The microemulsions from preconcentrate O20T40C40 was also found to be stable at ambient temperature over 20 days without significant change in particle size at different drug loadings. Dilution with different aqueous medium, either water, or simulated gastric fluid or simulated intestinal fluid, also did not change the particle sizes of the microemulsions. CONCLUSIONS: The combined use of surfactants in preconcentrate showed the promise in generating desired self-emulsifying microemulsions with small particle size, increased drug loading, and improved physical stability. This will have significant implications in future dosage development for poorly water-soluble drugs in using self-emulsifying microemulsions drug delivery system (SMEDDS).