Pulsatile blood flow in a stenosed artery—a theoretical model

To understand the special flow conditions which may be produced by the presence of stenosis in arteries, an analytical solution is obtained for pulsatile laminar flow in an elliptic tube. Blood is approximated by a Newtonian model and the geometry of the stenosis is introduced by specifying the change in area of cross-section of the stenosed artery with axial distance. The results for velocity, pressure, shear stress and impedance are presented. These are compared with the steady flow results as well as with those of the flow in a stenosed tube of circular cross-section. The study indicates that the fluid dynamic characteristics of the flow are affected by the percentage of stenosis as well as the geometry of the stenosis. The frequency of oscillation is also found to influence shearing stress and the impedance.     

Effectiveness of Hindfoot Arthrodesis by Stable Internal Fixation in Various Eichenholtz Stages of Neuropathic Ankle Arthropathy

The optimal time to treat neuropathic (Charcot) arthropathy of the ankle and peritalar joint is controversial because of the various treatment options available and the variable results reported in published studies. We sought to determine the outcome of hind foot arthrodesis with stable internal fixation in patients with different Eichenholtz stages of arthropathy. We prospectively studied patients with substantial disabilities caused by neuropathic arthropathy in deformed, unstable ankle and peritalar joints, with or without ulcerations, who had undergone treatment from July 2007 to December 2012. All patients underwent ankle arthrodesis, autologous iliac crest bone grafting, and subtalar joint arthrodesis, with or without talonavicular joint arthrodesis, fixed internally with an intramedullary hindfoot nail, with or without an additional plate or cancellous screws. Of the 33 enrolled patients, 9 (27.3%) had stage I, 13 (39.4%) had stage II, and 11 (33.3%) had stage III Charcot arthropathy. The cause of arthropathy was diabetes mellitus in 25 (75.8%) patients. The duration of symptoms ranged from 1 to 120 (median 7) months. The mean follow-up period was 40 (range 12 to 76) months and did not differ markedly among the groups. The hindfoot scores, rate of salvage or amputation, or complication rates did not differ significantly across Eichenholtz stage. For the patients with stage I, II, and III, the preoperative hindfoot score was 50, 49, and 48, respectively (p = .9). The corresponding postoperative scores were 68, 68, and 70 (p = .5). We found no evidence that the effectiveness of hindfoot arthrodesis by stable fixation varied across the Eichenholtz stage of Charcot arthropathy involving ankle and peritalar joint. Furthermore, we found that stable internal fixation and bone grafting using a hindfoot nail results in an 84.84% union rate and salvages the unstable and disabled foot in 90.9% of patients with ankle and peritalar Charcot arthropathy.     

Impact of Essentiale L on ethanol-induced changes in rat brain and erythrocytes

INTRODUCTION: The present study was designed to investigate the effect of Essentiale L, a mixture of polyenylphospholipids from soybeans, on oxidative stress in various brain regions, on erythrocytes (RBC) and on RBC membrane composition in ethanol-administered rats. METHODS: Adult male albino rats of body weight 150-170 g were divided into four groups and administered either isocaloric glucose (5 g/kg body weight/day) or ethanol (6 g/kg body weight/day) through oral gavage. Essentiale L was administered to a set of ethanol-fed rats and the control rats at a dosage of 300 mg/kg body weight/day through oral gavage. The treatment protocol was carried out for 45 days. At the end of the experimental period, the animals were sacrificed, and the biochemical parameters related to the lipid profile, oxidative stress and thiol status were assayed in the brain regions, RBC and RBC membrane. RESULTS: Ethanol administration resulted in increased levels of lipid peroxidation products in RBC and different brain regions, such as the cortex, cerebellum, striatum, hippocampus and hypothalamus, and depletion of enzymatic and nonenzymatic antioxidants and alterations in oxidised glutathione/glutathione (GSSG/GSH) ratio and thiol groups (protein-bound and total), signifying oxidative stress. Ethanol-treated rats also showed significant alterations in protein content and lipid composition in RBC membranes. Significant differences in the relative proportions of hexose, hexosamine and sialic acid of the membranes were observed. Administration of Essentiale L prevented all the alterations induced by ethanol and returned their levels to near-normal. CONCLUSION: These findings suggest that Essentiale L, a therapeutic adjunct for liver diseases, also has bioprotective effects on nonhepatic tissues and cells.     

Screening of Chemical Penetration Enhancers for Transdermal Drug Delivery Using Electrical Resistance of Skin

Purpose  A novel technique is presented for identifying potential chemical penetration enhancers (CPEs) based on changes in the electrical resistance of skin. Methods  Specifically, a multi-well resistance chamber was designed and constructed to facilitate more rapid determination of the effect of CPEs on skin resistance. The experimental setup was validated using nicotine and decanol on porcine skin in vitro. The multi-well resistance chambers were capable of operating at 37°C in order to simulate the physiological temperature of the human body. Further, the utility of the multi-well resistance chamber technique was validated using standard Franz diffusion cells. Electrical resistance measurements were used to evaluate the potency of seven new potential CPEs, identified using virtual screening algorithms. From the resistance measurements, the chemicals 1-dodecyl-2-pyrrolidinone (P), menthone (M) and R(+)-3-amino-1-hydroxy-2-pyrrolidinone (C) were identified as the better penetration enhancers among the seven tested. Further, traditional permeation experiments were performed in Franz diffusion cells to confirm our findings. Results  The permeation test results indicated that, of the three CPEs deemed potentially viable using the newly-developed resistance screening technique, both P and M increased the permeation of the test drug (melatonin) through skin in 48 h. Conclusion  In summary, this resistance technique can be used to effectively pre-evaluate potential CPEs, thereby reducing the time required to conduct the permeability studies.     

Association of − 757T > C polymorphism of C-reactive protein gene with chronic periodontitis of South Indian population

Inflammation Research - CRP gene polymorphism is common in inflammatory diseases, but such association has not been reported in periodontitis. Our objective was to interrogate SNPs of crp in...     

Cleistanthin A,a diphyllin glycoside from Cleistanthus collinus,is cytotoxic to PHA‐stimulated (proliferating) human lymphocytes

An ideal anticancer drug would be one that preferentially kills tumor cells with the least toxicity to normal cells. Cleistanthin A, a diphyllin glycoside of the tropical plant Cleistanthus collinus, was found to possess cytotoxic and tumor regressing properties. To find out whether this compound acts selectively on proliferating cells it was tested against quiescent and proliferating human lymphocytes. Mitogen‐stimulated and unstimulated human lymphocytes were treated with cleistanthin A. A cytotoxicity assay using MTT was used to assess the viability of the cells. Percentage viability of the unstimulated and treated cells were normalized to that of the untreated and unstimulated cells and percentage viability of stimulated and treated cells were normalized to that of stimulated and untreated cells. Quiescent lymphocytes were refractory to the action of cleistanthin A. Only proliferating cells were killed. Cell death was proportional to the percentage of cells in the proliferating stage and was also dose‐dependent. Quiescent lymphocytes pretreated with cleistanthin A had the ability to proliferate upon subsequent stimulation with PHA. These results indicate that cleistanthin A does not affect the viability of quiescent cells. Also, it did not affect the proliferating potential of quiescent cells. However, this compound drastically affected proliferating cells by reducing their viability to 10–20%. Our results therefore indicate that the antiproliferative property of cleistanthin A could be used in regimens for treating tumors with extensive proliferative potencies. Drug Dev. Res. 51:187–190, 2000. © 2001 Wiley‐Liss, Inc.     

Multi-Region Risk-Sensitive Cognitive Ensembler for Accurate Detection of Attention-Deficit/Hyperactivity Disorder

Cognitive Computation - In this paper, we present a multi-region ensemble classifier approach (MRECA) using a cognitive ensemble of classifiers for accurate identification of...