RUSSELL GRIMWADE PRIZE

The only valid reason for the state to invest in forest growing is to provide or protect social benefits which are considered important but which would not otherwise be adequately or fairly supplied through private forestry. Such multiple objectives can be met by exploiting the joint production possibilities of forest growth, but the returns are a complex mixture of quantifiable, partly quantifiable and unquantifiable values. One of the quantifiable outputs is wood, and the returns from it can be measured in financial terms. But in growing forests for social purposes wood is really a by-product or a means of achieving certain social purposes. Attempts therefore to assess the adequacy of the returns to the state as a forest grower in terms of the revenue from timber growing are of doubtful logic and so fraught with difficulties, as to be not worth the effort. Concern would be more usefully directed toward the costs of producing the multiple returns of state forestry.     

Optimization,in vitro release and toxicity evaluation of novel pH sensitive itaconic acid-g-poly(acrylamide)/sterculia gum semi-interpenetrating networks

BackgroundIn recent era, pH sensitive polymeric carriers that combines the materials engineering and medicine is gaining researcher’s attention as they maximizes drug concentration at site of absorption and reduces side effects for e.g. orally administered cetirizine HCl (CTZ HCl) upsets the stomach and furthermore shows high intestinal absorption. Thus, development of pH sensitive hydrogels with sufficient mechanical strength will be good candidate to address this issue.MethodsHere, we developed pH sensitive itaconic acid-g-poly(acrylamide)/sterculia gum (IA-g-poly(AM)/sterculia gum) semi-interpenetrating network (semi-IPN) by free radical polymerization technique for intestinal delivery of CTZ HCL.ResultsOptimized formulation (I5) with 6% w/w IA showed negligible swelling at pH 1.2, and maximum swelling at pH 7.4. Solid state characterization of optimized formulation showed successful development of semi-IPN structure and incorporation of drug without any noticeable drug-carrier interaction. In vitro release study showed biphasic pH dependent release of CTZ HCl, where initial burst release was observed at acidic pH followed by sustained release at basic pH. Acute oral toxicity and histopathological studies confirmed the non-toxic nature of IA-g-poly(AM)/sterculia gum.ConclusionConclusively, developed biocompatible semi-IPN hydrogels with sufficient pH sensitivity and mechanical strength could serve as a potential carrier for intestinal delivery of CTZ HCL to maximize its absorption and reduce side effects.Graphical abstract Supplementary InformationThe online version contains supplementary material available at 10.1007/s40199-021-00395-8.     

腹腔镜下生物胶治疗上消化道急性穿孔

目的 评价腹腔镜下生物胶治疗上消化道急性穿孔的有效性和安全性。方法 回顾性分析17例上消化道急性穿孔的病例资料。结果 本组病例无死亡、手术效果好。结论 腹腔镜下生物胶治疗上消化道急性穿孔具有创伤小、美观、术后恢复快，值得推广。     

白及胶提取工艺研究

目的探讨白及胶提取的影响因素,确定适宜的提取条件。方法以白及胶提取得率为指标进行正交试验设计,考察了加水量,回流提取时间,醇沉浓度等三个因素对白及胶提取率的影响。结果最佳提取制备工艺:加水量为12倍,回流时间为2 h,醇沉浓度为80%。结论该方法提取白及胶稳定可行。     

白芨胶对大鼠皮肤成纤维细胞VEGFmRNA表达的影响

目的:研究白芨胶对体外培养的大鼠皮肤成纤维细胞VEGFmRNA表达的影响,探讨白芨胶促进伤口愈合的分子机制。方法:体外培养大鼠皮肤成纤维细胞,分别给予不同浓度的白芨胶进行干预,然后用RT-PCR技术分别检测各组细胞的VEGFmRNA表达,并进行定量分析。结果:白芨胶在不同浓度时连续干预至第3d,以0.5mg/ml浓度条件下,VEGFmRNA表达最强。结论:白芨胶对体外培养的大鼠皮肤成纤维细胞VEGFmRNA表达有明显促进作用,其作用强度随浓度而改变。     

In vitro fermentation characteristics of a mixture of Raftilose and guar gum by human faecal bacteria

Summary Background The therapeutic effects of indigestible carbohydrates in the human colon are well known. Most fermentation studies have examined only single carbohydrates. Considering the idiosyncratic actions of individual carbohydrates and the dose required, it is unlikely that any one carbohydrate will provide ideal physiological actions without having some undesirable effects. Little is known of how mixing non–digestible carbohydrates affects their fermentation. This necessitates fermentation studies using different carbohydrates in mixtures. Aim of the study The aim of this study was to test the effect of mixing Raftilose™ (R) and guar gum (G) on short chain fatty acid (SCFA) production in in vitro cultures of human faecal bacteria. Method The fermentation of the individual carbohydrates (10 mg/ml) was compared with that of a 50:50 mixture in anaerobic in vitro cultures of human faeces. Results Cultures of R/G mixtures produced significantly more n–butyrate than 100 mg G alone at 8 and 24 hours (p < 0.02). There was no significant difference in the production of n–butyrate between cultures of 100 mg R and the R/G mixture at 8 and 24 hours. R (100 mg) produced a propionic/butyric (p/b) acid ratio of 1.18 compared with 3.88 for 100 mg G, whereas R/G mixture produced a p/b ratio of 2.01. Conclusion The fermentation of R/G mixture was different compared with 100 mg of R or G alone. There was no loss of n–butyrate in the culture containing R/G (50 mg of each) mixture compared with the 100 mg R culture.     

Evaluation of honey locust (Gleditsia triacanthos Linn.) gum as sustaining material in tablet dosage forms

In this study, honey locust gum (HLG) obtained from Gleditsia triacanthos (honey locust) beans was investigated as a hydrophilic matrix material in the tablets prepared at different concentrations (5% and 10%) by wet granulation method. Theophylline was chosen as a model drug. The matrix tablets containing hydroxyethylcellulose and hydroxypropyl methylcellulose as sustaining polymers at the same concentrations were prepared and a commercial sustained release (CSR) tablet containing 200 mg theophylline was examined for comparison of HLG performance. Physical analysis on CSR tablet, matrix tablets and their granules before compression were performed. According to the results obtained from dissolution studies in distilled water, pH 1.2 HCl buffer and pH 7.2 phosphate buffer, no significant difference was found between CSR tablet and the matrix tablet containing 10% HLG in each medium (P > 0.05) and these tablets showed zero-order kinetic model in all the mediums.     

The rigid nasendoscope as a tool for difficult tracheal intubation: a manikin study

We examined the use of the 30 degrees rigid nasendoscope in aiding difficult tracheal intubations. A Cormack and Lehane grade 4 difficult intubation (no view of glottis or epiglottis) was set up on a manikin. After 10 s of tuition, 40 anaesthetists attempted to pass a standard gum elastic bougie between the cords, with and without the nasendoscope, in randomised order. A bougie curved to an 'optimal curve' was also tested. Using the standard bougie 13/40 (33%) passed the bougie between the cords without the nasendoscope, compared with 31/40 (78%) when using the nasendoscope (p < 0.001). The 'optimal curve' bougie resulted in 29/40 (73%) and 39/40 (98%) success rates without and with the nasendoscope, respectively (p = 0.004). The nasendoscope is a simple and easy to use tool in grade 4 intubation, and results are improved further by the use of an 'optimal curve' bougie.     

Oral habits among adolescent girls and their association with symptoms of temporomandibular disorders

AIM: To evaluate the contribution of certain parafunctional activities to the presence of temporomandibular disorder (TMD) symptoms among teenage girls, with special emphasis to gum chewing and jaw play. METHODS: A total of 323 girls, aged 15-16 years, were randomly selected from a religious junior high school. The girls responded to a questionnaire on oral habits and TMD symptoms. RESULTS: Gum chewing was a very prevalent habit (62.4%), performed daily (mean chewing time 3.95 h day-1). Girls who chewed intensively (more than 4 h day-1) showed associations with pain in the ear area during function and at rest, as well as with joint noises. Jaw play, although reported by only 14.3%, was significantly associated with pain in the ear area during function and at rest, feeling of tiredness of the jaw while chewing, joint noises, catch and lock. All oral parafunctions, except chewing gum, were associated with jaw play and with each other. CONCLUSIONS: Jaw play was the most detrimental habit in TMD; intensive gum chewing was a potentially contributing factor for joint noises and pain. Oral parafunctions (except chewing gum) were significantly associated between themselves and suggest a behavioural pattern of "jaw hyperactivity".     

Guar gum reduces postprandial hypotension in older people

OBJECTIVE: To determine whether slowing of gastric emptying and glucose absorption with guar gum would reduce the fall in blood pressure after an oral glucose load in older subjects. DESIGN: A randomized, experimental, cross-over study. SETTING: Department of Nuclear Medicine, Royal Adelaide Hospital, Adelaide, SA, Australia. PARTICIPANTS: Ten healthy subjects, age 67 to 78. MEASUREMENTS: Simultaneous measurements of gastric emptying, blood pressure, blood glucose, serum insulin, and oral glucose absorption (3-O-methyl-D-glucose [3-OMG]) on two occasions after ingestion of 300 mL water containing 50 g glucose and 30 mL lemon juice, 3 g 3-OMG labeled with 99mTc-sulphur colloid; with or without 9 g guar gum. Blood pressure and gastric emptying were monitored for 180 minutes. RESULTS: The magnitude of the falls in systolic (P = .02), diastolic (P < .05), and mean arterial (P = .05) blood pressure were less, and gastric emptying slower (P < .05), after guar. Blood glucose, insulin, and 3-OMG concentrations were reduced (P < .001 for all) by guar. 3-OMG concentrations were inversely related to the intragastric retention of glucose (r = -0.72, P = .02) and blood pressure was inversely related to 3-OMG (r = -0.64, P < .05) after the drink without guar. The blood glucose concentration was related to 3-OMG (r > 0.64, P < .05). CONCLUSION: Guar gum reduces the magnitude of the fall in blood pressure after oral glucose. Slowing of gastric emptying and glucose absorption may represent a novel approach to the treatment of postprandial hypotension.