Surface-engineered liposomal particles of calcium ascorbate with fenugreek galactomannan enhanced the oral bioavailability of ascorbic acid: a randomized,double-blinded, 3-sequence,crossover study

The antioxidant, anti-inflammatory, immunomodulating, anti-thrombotic, and antiviral effects along with its protective effects against respiratory infections have generated a great interest in vitamin C (vitC) as an attractive functional/nutraceutical ingredient for the management of COVID-19. However, the oral bioavailability and pharmacokinetics of vitC have been shown to be complex and exhibit dose-dependent non-linear kinetics. Though sustained-release forms and liquid liposomal formulations have been developed, only marginal enhancement was observed in bioavailability. Here we report a novel surface-engineered liposomal formulation of calcium ascorbate (CAAS), using fenugreek galactomannan hydrogel in powder form, and its pharmacokinetics following a randomized, double-blinded, single-dose, 3-way crossover study on healthy human volunteers (n = 14). The physicochemical characterization and in vitro release studies revealed the uniform impregnation of CAAS liposomes within the pockets created by the sterically hindered galactomannan network as multilaminar liposomal vesicles with good encapsulation efficiency (>90%) and their stability and sustained-release under gastrointestinal pH conditions. Further human studies demonstrated >7-fold enhancement in the oral bioavailability of ascorbate with a significant improvement in pharmacokinetic properties (C_max, T_max, T_1/2, and AUC), compared to the unformulated counterpart (UF-CAAS) when supplemented at an equivalent dose of 400 mg of CAAS as tablets and capsules.

A green process to modulate the surface properties of liposome was reported using fenugreek galactomannan hydrogel and successfully applied to vitamin C with significant enhancement in human oral bioavailability.     

氯胺酮复合麻醉在小儿白内障手术中的应用

对照研究小儿白内障手术278眼次中采用氯胺酮单纯麻醉和氯胺酮联合氧化亚氮或安定麻醉的方法.结果显示:(1)复合麻醉比单纯麻醉更有利于维持麻醉过程的稳定性和减少氯胺酮的用量与副作用,对心血管系统和手术过程影响小,并且不增加额外的麻醉操作.(2)男性比女性有更大可能的麻醉耐受性.(3)氯胺酮静脉用药的复合麻醉可作为小儿白内障手术的首选麻醉方法.     

Systemic to pulmonary arterial shunts in neonates

Background The major strategy for palliation of cyanotic lesions in neonates is the systemic to pulmonary arterial shunt. Methods Between May 1995, and December 2002, 48 consecutive neonates underwent systemic to pulmonary arterial shunts for cyanosis with reduced pulmonary blood flow. The mean age was 11.6 days (±SD 7.38) and the mean weight, 3.2kg (±SD 0.52). The babies were classified into three groups: Group I-Tetralogy-pulmonary Atresia (n=18), Group II-single Ventricle-Pulmonary atresia without (n=19) and with (n=5) isomerism, Group III-Pulmonary Atresia with Intact ventricular septum (n=6). Diagnosis was made by 2D echocardiography. Indication for cardiac catheterization was delineation of pulmonary anatomy/ductus laterality (n=4) or balloon atrial septostomy (n=4). The surgical procedure was a modified Blalock-Taussig shunt on the side of the situs. Post-operatively, no anti-coagulation or anti-platelet medication was employed. Results There was no mortality. Four cases required revision of the shunt in the immediate post-operative period for shunt thrombosis. The mean follow up was 17.54 months (±SD 8.36). In Group I, nine patients have undergone total correction with or without a conduit, while three required new arterial shunts for shunt/pulmonary artery stenosis. In Group II, nine patients have undergone bi-directional Glenn with atrial septectomy (n=2) and pulmonary artery plasty (n=4) and one patient underwent Fontan completion. In Group III, two patients underwent bi-directional Glenn and two had pulmonary valvotomy with/without right ventricular outflow tract widening. All the remaining babies are waiting for the second/final stage palliation or total correction. Conclusion Systemic to pulmonary arterial shunts in neonates is a gratifying and reasonably safe surgical procedure. Most babies become candidates for eventual univentricular/bi-ventricular repair.     

Topical anaesthesia of the skin: a review

The ability to provide painless venepuncture and venous cannulation is a major advance in paediatric practice. Topical local anaesthesia of the skin can allow such procedures to be carried out with little or no discomfort in children of all ages. This has obvious psychological benefits for children, particularly those subjected to repeated procedures. The techniques for anaesthetizing the skin to be effective and safe must be based upon an understanding of the anatomy and physiology of the skin, the pharmacology of local anaesthetic agents and their behaviour when applied to the skin. Although eutectic mixture of local anaesthetics (EMLA cream) (Astra Pharmaceuticals) is the market leader, promising new preparations are being evaluated with the aim of decreasing the onset time of effective analgesia. New clinical applications for topical anaesthesia of the skin are appearing and it is likely that these will be increasingly used in the future.     

Relationship of physical activity vs body mass index with type 2 diabetes in women

CONTEXT: Physical inactivity and body mass index (BMI) are established independent risk factors in the development of type 2 diabetes; however, their comparative importance and joint relationship with diabetes are unclear. OBJECTIVE: To examine the relative contributions and joint association of physical activity and BMI with diabetes. DESIGN, SETTING, AND PARTICIPANTS: Prospective cohort study of 37 878 women free of cardiovascular disease, cancer, and diabetes with 6.9 years of mean follow-up. Weight, height, and recreational activities were reported at study entry. Normal weight was defined as a BMI of less than 25; overweight, 25 to less than 30; and obese, 30 or higher. Active was defined as expending more than 1000 kcal on recreational activities per week. MAIN OUTCOME MEASURE: Incident type 2 diabetes, defined as a new self-reported diagnosis of diabetes. RESULTS: During the follow-up, 1361 cases of incident diabetes occurred. Individually, BMI and physical activity were significant predictors of incident diabetes. Compared with normal-weight individuals, the multivariate-adjusted hazard ratio (HR) was 3.22 (95% confidence interval [CI], 2.69-3.87) for overweight individuals and 9.09 (95% CI, 7.62-10.8) for obese individuals. For overall activity (kilocalories expended per week), compared with the least active first quartile, the multivariate-adjusted HRs were 0.91 (95% CI, 0.79-1.06) for the second quartile, 0.86 (95% CI, 0.74-1.01) for the third, and 0.82 (95% CI, 0.70-0.97) for the fourth (P for trend =.01). In the combined analyses, overweight and obese participants, whether active or inactive, had significantly elevated risks, compared with normal-weight active individuals. The multivariate-adjusted HRs were 1.15 (95% CI, 0.83-1.59) for normal-weight inactive, 3.68 (95% CI, 2.63-5.15) for overweight active, 4.16 (95% CI, 3.05-5.66) for overweight inactive, 11.5 (95% CI, 8.34-15.9) for obese active, and 11.8 (95% CI, 8.75-16.0) for obese inactive participants. CONCLUSIONS: Although BMI and physical inactivity are independent predictors of incident diabetes, the magnitude of the association with BMI was greater than with physical activity in combined analyses. These findings underscore the critical importance of adiposity as a determinant of diabetes.     

The protective effect of supplemental calcium on colonic permeability depends on a calcium phosphate-induced increase in luminal buffering capacity

An increased intestinal permeability is associated with several diseases. Previously, we have shown that dietary Ca decreases colonic permeability in rats. This might be explained by a calcium-phosphate-induced increase in luminal buffering capacity, which protects against an acidic pH due to microbial fermentation. Therefore, we investigated whether dietary phosphate is a co-player in the effect of Ca on permeability. Rats were fed a humanised low-Ca diet, or a similar diet supplemented with Ca and containing either high, medium or low phosphate concentrations. Chromium-EDTA was added as an inert dietary intestinal permeability marker. After dietary adaptation, short-chain fructo-oligosaccharides (scFOS) were added to all diets to stimulate fermentation, acidify the colonic contents and induce an increase in permeability. Dietary Ca prevented the scFOS-induced increase in intestinal permeability in rats fed medium- and high-phosphate diets but not in those fed the low-phosphate diet. This was associated with higher faecal water cytotoxicity and higher caecal lactate levels in the latter group. Moreover, food intake and body weight during scFOS supplementation were adversely affected by the low-phosphate diet. Importantly, luminal buffering capacity was higher in rats fed the medium- and high-phosphate diets compared with those fed the low-phosphate diet. The protective effect of dietary Ca on intestinal permeability is impaired if dietary phosphate is low. This is associated with a calcium phosphate-induced increase in luminal buffering capacity. Dragging phosphate into the colon and thereby increasing the colonic phosphate concentration is at least part of the mechanism behind the protective effect of Ca on intestinal permeability.