A review of the extraction methods and advanced applications of lignin-silica hybrids derived from natural sources.

The global trend of increasing energy demand along the large volume of wastewater generated annually from the paper pulping and cellulose production industries are considered as serious dilemma that may need to be solved within these current decades. Within this discipline, lignin, silica or lignin-silica hybrids attained from biomass material have been considered as prospective candidates for the synthesis of advanced materials. In this study, the roles and linking mechanism between lignin and silica in plants were studied and evaluated. The effects of the extraction method on the quality of the obtained material were summarized to show that depending on the biomass feedstocks, different retrieval processes should be considered. The combination of alkaline treatment and acidic pH adjustment is proposed as an effective method to recover lignin-silica with high applicability for various types of raw materials. From considerations of the advanced applications of lignin and silica materials in environmental remediation, electronic devices and rubber fillers future valorizations hold potential in conductive materials and electrochemistry. Along with further studies, this research could not only contribute to the development of zero-waste manufacturing processes but also propose a solution for the fully exploiting of by-products from agricultural production.

Commonly used preparations for colonoscopy: efficacy, tolerability, and safety--a Canadian Association of Gastroenterology position paper.

INTRODUCTION: The increased demand for colonoscopy, coupled with the introduction of new bowel cleansing preparations and recent caution advisories in Canada, has prompted a review of bowel preparations by the Canadian Association of Gastroenterology. METHODS: The present review was conducted by the Clinical Affairs group of committees including the endoscopy, hepatobiliary/transplant, liaison, pediatrics, practice affairs and regional representation committees, along with the assistance of Canadian experts in the field. An effort was made to systematically assess randomized prospective trials evaluating commonly used bowel cleansing preparations in Canada. RESULTS: Polyethylene glycol (PEG)-; sodium phosphate (NaP)-; magnesium citrate (Mg-citrate)-; and sodium picosulphate, citric acid and magnesium oxide (PSMC)-containing preparations were reviewed. Regimens of PEG 2 L with bisacodyl (10 mg to 20 mg) or Mg-citrate (296 mL) are as effective as standard PEG 4 L regimens, but are better tolerated. NaP preparations appear more effective and better tolerated than standard PEG solutions. PSMC has good efficacy and tolerability but head-to-head trials with NaP solutions remain few, and conclusions equivocal. Adequate hydration during preparation and up to the time of colonoscopy is critical in minimizing side effects and improving bowel cleansing in patients receiving NaP and PSMC preparations. All preparations may cause adverse events, including rare, serious outcomes. NaP should not be used in patients with cardiac or renal dysfunction (PEG solution is preferable in these patients), bowel obstruction or ascites, and caution should be exercised when used in patients with pre-existing electrolyte disturbances, those taking medications that may affect electrolyte levels and elderly or debilitated patients. Health Canada's recommended NaP dosing for most patients is two 45 mL doses 24 h apart. However, both safety and efficacy data on this dosing schedule are lacking. Many members of the Canadian Association of Gastroenterology expert panel administer both doses within 24 h, as studied in clinical trials, after careful one-on-one discussion of risks and benefits in carefully selected patients. Safety data on PSMC and combination preparations in North America are limited and clinicians are encouraged to keep abreast of developments in this area. CONCLUSIONS: All four preparations reviewed provided effective bowel cleansing for colonoscopy in the majority of patients, with varying tolerability. Adequate hydration is essential in patients receiving the preparations.

Urinary tract infections in extended care facilities: preventive management strategies.

OBJECTIVE: To provide health care professionals with an overview of interventions that may be done to reduce the incidence of urinary tract infections (UTIs) in elderly patients, especially those residing in extended care facilities. DATA SOURCES: A Medline search of the English literature was performed from 1980 to January 2006 to find literature relevant to urinary tract prophylaxis. Further references were hand-searched from relevant sources. STUDY SELECTION: When assessing the effectiveness of various clinical interventions for reducing the incidence of UTIs in the elderly, preference was given to more recent, double-blind, placebo-controlled randomized studies, but studies of less robust design also were included in the discussions when the former were lacking. DATA EXTRACTION: Where possible, recent publications were favored over older studies. References were all reviewed by the authors and chosen to present key citations. DATA SYNTHESIS: Data selection was prioritized to address specific subtopics. CONCLUSION: Though still frequent in occurrence and quite costly in terms of morbidity, mortality, and cost to the health care system, numerous measures may be taken to ameliorate the incidence of UTIs in elderly, institutionalized residents. First and foremost, establishing and adhering to good infection-control practices by health care givers and minimizing the use of indwelling catheters are essential. Adequate staffing and training are germane to this effort. Reasonably well-designed clinical studies also give credence to the use of topical estrogens and lactobacillus "probiotics" for female subgroups and cranberry juice for a wider array of patients. Vitamin C is of no proven benefit. With regard to antibiotics, with the relative paucity of data available for this patient population, concerns for resistance proliferation must be balanced against perceived gains in UTI reduction.

Precision of the one- versus two-handed method of skinfold measurement in the obese.

Skinfolds at five anatomic sites were measured on 47 subjects in a study of gallbladder disease in Starr County, Texas, by two methods, one and two handed. A comparison was made of the two methods as to bias and precision. There were statistically significant but biologically unimportant differences (on the order of 1-2 mm) at four of the five sites. At three of these, the two-handed method gave larger values (lower thigh, triceps, and subscapular), and at the other site (medial calf) this method produced smaller values on average. Measurement precision was improved using the two-handed method at three of the five sites, significantly so for the triceps skinfold. Measuring skinfolds with two hands improves the precision of measurement for some skinfold sites in obese individuals. It does not introduce important and systematic biases across skinfold sites. Adoption of this technique should be used when circumstances outweigh the cost of involving an extra observer in the measurement of skinfold thickness, such as when precision is very important and when subjects are obese. © 1995 Wiley-Liss, Inc.

Cyclosporine for severe ulcerative colitis.

OBJECTIVE: To evaluate evidence for the use of cyclosporine in treating patients with severe ulcerative colitis. DATA SOURCES: A literature search was performed using MEDLINE, EMBASE, Cochrane Database, and ISI Web of Knowledge (1966-November 2005) with the search terms cyclosporine, cyclosporin A, CsA, ulcerative colitis, UC, inflammatory bowel disease, IBD, steroid-refractory, and immunosuppression. Additional papers were located by hand-searching relevant references. Only human studies in adults and literature published in English were included. DATA SYNTHESIS: Intravenous cyclosporine has been evaluated for the treatment of severe ulcerative colitis in 4 randomized, controlled trials, as well as in many open-label and retrospective studies. Studies that evaluated cyclosporine for severe ulcerative colitis were reviewed. All 4 controlled trials showed an initial positive clinical response as defined by the Crohn's Activity Index when intravenous cyclosporine 4 mg/kg/day was administered as monotherapy or combined with intravenous corticosteroids. One of the 4 trials indicated that high-dose cyclosporine (4 mg/kg/day) has no additional clinical benefit over the low-dose (2 mg/kg/day) and that the lower dose may improve safety related to dose-dependent adverse effects. CONCLUSIONS: There is evidence to support the use of intravenous cyclosporine for patients with severe ulcerative colitis who are refractory to corticosteroid therapy. Because most of the adverse effects associated with cyclosporine are dose dependent, therapy should be initiated with the lower 2 mg/kg/day dose. Subsequent doses should be adjusted based on cyclosporine blood concentrations of 150-250 ng/mL. Cyclosporine should be used only to induce remission and serve as a "bridge" to azathioprine or 6-mercaptopurine maintenance therapy. At this time, there are insufficient data to support the long-term use of cyclosporine monotherapy for avoidance of surgery or maintenance of remission.

Acid suppressive therapy use on an inpatient internal medicine service.

BACKGROUND: Use of acid suppressant medications has increased in both frequency and breadth in recent years. Data have indicated that questionable use of acid suppressants for non-accepted indications is common. OBJECTIVE: To assess the indications and prevalence of acid suppressants used by inpatients on admission and at discharge. METHODS: A retrospective chart review of 213 patients admitted to the University of Michigan Hospital non-critical care general medical service was conducted. Relevant medical history, acid suppressant drug used, and indications were collected from both inpatient medical records and discharge medication lists. RESULTS: Of the 213 patients reviewed, 29% were taking acid suppressants prior to admission, with 33% being proton pump inhibitors (PPIs). Once patients were admitted, acid suppressant use increased to 71% (152 of 213), with 84% PPIs, 11% histamine(2)-receptor antagonists, and 5% combination therapy. Based upon our criteria, only 10% (15 of 152) of those on acid suppressants were found to have an acceptable indication. In patients where any history of gastroesophageal reflux disorder (GERD) was deemed as an acceptable indication (32 other patients), 31% (47 of 152) had an acceptable indication. For the 137 patients with non-accepted indications, 29% had no discernable indication and 38% were prescribed acid suppressants for corticosteroid-associated or stress ulcer prophylaxis. A history of gastrointestinal bleeds or peptic ulcer disease of more than 3 months since initial diagnosis or documented exacerbation of symptoms comprised 8% of the population. The aforementioned group of GERD patients made up 23% of this group. Compared to the 29% of patients taking acid suppressants prior to admission, 54% (115 of 213) of patients were prescribed acid suppressants at discharge. If only recent exacerbations of GERD were deemed as long-term indications, 10% (12 of 115) of these patients were found to have accepted indications. If all GERDs were acceptable long-term indications, 27% (31 of 115) would have met criteria for acceptable outpatient use. CONCLUSIONS: There is considerable excess usage of acid suppressants in both the inpatient and outpatient settings.