Carboxymethyl Cellulose, Trichloroacetic Acid, and Unna Boot for Healing Venous Ulcers: A Comparative Study of Their Efficacy and Socioeconomic Impact.

Chronic ulcers are defined as a breakdown of the long-term cutaneous barrier or frequent recurrence of breakdowns. Dressings are a form of treatment and, in view of the variety and high cost of the products on the market, three agents were selected for this investigation, regarding their efficacy and cost/benefit ratio. The objective of the investigation was to evaluate and compare the efficacy, costs, and benefits of carboxymethylcellulose in paste at 20% (CMC 20%), trichloroacetic acid at 90% (TCA 90%), and Unna boot for treatment of chronic venous ulcers. Three groups of 30 patients each were chosen randomly for ambulatory treatment with TCA 90% (G1), CMC 20% (G2), and Unna boot (G3). The evolution of the cicatricial process of each group separately and between groups was analyzed with measurement of the lesion areas in square centimeters (cm2) and observation of the amount of exudate from observation of the photographic record, until their healing, in the maximum period of 20 weeks. A significant reduction of lesion areas in all groups was observed (P=.0001), with a median reduction of 7.6 cm2 (38.1%) for G1, 3.9 cm2 (38.8%) for G2, and 16.2 cm2 (77.8%) for G3. There was a significant difference in the absolute delta of the lesion areas (P=.0001) of the groups. The three types of treatments promoted effective improvement, with acquisition and utilization of all three products in the public health services being recommended.

Economical fermentation media for the production of a whole cell catalyst for the treatment of Cr(VI)-containing wastewaters.

The biotechnology sector is continually seeking sustainable and more economical bioprocesses. Fermentation media produced with cheap components or wastes reduce production costs. Moreover, if wastes are used, they contribute to avoid environmental pollution. In this work, microbial growth media based on molasses or acidified glycerol as carbon sources and fertilizer as nitrogen source were tested for the production of a whole-cell catalyst that could be used in Cr(VI)-containing wastewater treatments. Results showed that the highest biomass production yield was obtained with a medium containing acidified glycerol 5% v/v and fertilizer 0.6% v/v. The biomass produced using this medium was immobilized in calcium alginate beads and used as catalyst in the biotransformation of Cr(VI) into Cr(III). The catalyst could be efficiently used for 5 reduction cycles of 40mg/l Cr(VI) each. Cr(III) retention assays were performed to determine whether Cr(III) could be retained by the catalyst avoiding its solubilization in the supernatants. The retention capacity of the catalyst at 32°C and pH 3.0 was 3mg Cr(III)/g. Both an alternative and economical fermentation medium is here proposed for the optimization of Cr(VI)-containing wastewater treatment.

An analysis of 72% chromated glycerin used for sclerotherapy: sterility, potency, and cost after extended shelf life.

BACKGROUND: Sclerotherapy is the treatment of reticular veins and telangiectasias of the lower extremities. Sclerosants destroy endothelial tissue and expose subendothelial collagen fibers, which lead to subsequent fibrosis of vessels, thus preventing recanalization. There are several available sclerosants including sodium tetradecyl sulfate (STS), polidocanol (POL), and chromated glycerin (CG) with varying efficacy, potency, side effect profile, and cost. OBJECTIVE: To identify the possible bacterial contamination and potency of CG beyond the current recommended shelf life of 3 months and to prove if CG is as cost effective as other available sclerosants. METHODS: Samples of 72% CG underwent bacterial endotoxin, sterility, and potency analysis at Days 0, 24, and 183. In addition, cost comparison was performed with other commercially available sclerosants including STS and POL. RESULTS: No samples of CG showed any bacterial contamination. All aliquots of glycerin remained sterile at Day 14. Potency at Day 24 was 99.2%, which was the same at Day 183. Cost comparison with other sclerosants revealed that CG is lower cost per milliliter than STS and POL. CONCLUSION: Seventy-two percent CG has no contamination and maintains its reported potency up to 6 months while comparable with the cost of other commercially available sclerosants.

Bio-hydrogen production by biodiesel-derived crude glycerol bioconversion: a techno-economic evaluation.

Global biodiesel production is continuously increasing and it is proportionally accompanied by a huge amount of crude glycerol (CG) as by-product. Due to its crude nature, CG has very less commercial interest; although its pure counterpart has different industrial applications. Alternatively, CG is a very good carbon source and can be used as a feedstock for fermentative hydrogen production. Further, a move of this kind has dual benefits, namely it offers a sustainable method for disposal of biodiesel manufacturing waste as well as produces biofuels and contributes in greenhouse gas (GHG) reduction. Two-stage fermentation, comprising dark and photo-fermentation is one of the most promising options available for bio-hydrogen production. In the present study, techno-economic feasibility of such a two-stage process has been evaluated. The analysis has been made based on the recent advances in fermentative hydrogen production using CG as a feedstock. The study has been carried out with special reference to North American biodiesel market; and more specifically, data available for Canadian province, Québec City have been used. Based on our techno-economic analysis, higher production cost was found to be the major bottleneck in commercial production of fermentative hydrogen. However, certain achievable alternative options for reduction of process cost have been identified. Further, the process was found to be capable in reducing GHG emissions. Bioconversion of 1 kg of crude glycerol (70 % w/v) was found to reduce 7.66 kg CO(2) eq (equivalent) GHG emission, and the process also offers additional environmental benefits.

Experimental assessment of toxic phytochemicals in Jatropha curcas: oil, cake, bio-diesel and glycerol.

BACKGROUND: Jatropha curcas seed is a rich source of oil; however, it can not be utilised for nutritional purposes due to presence of toxic and anti-nutritive compounds. The main objective of the present study was to quantify the toxic phytochemicals present in Indian J. curcas (oil, cake, bio-diesel and glycerol). RESULTS: The amount of phorbol esters is greater in solvent extracted oil (2.8 g kg⁻¹) than in expeller oil (2.1 g kg⁻¹). Liquid chromatography-mass spectroscopy analysis of the purified compound from an active extract of oil confirmed the presence of phorbol esters. Similarly, the phorbol esters content is greater in solvent extracted cake (1.1 g kg⁻¹) than in cake after being expelled (0.8 g kg⁻¹). The phytate and trypsin inhibitory activity of the cake was found to be 98 g kg⁻¹ and 8347 TIU g⁻¹ of cake, respectively. Identification of curcin was achieved by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and the concentration of curcin was 0.95 g L⁻¹ of crude concentrate obtained from cake. CONCLUSION: Higher amounts of phorbol esters are present in oil than cake but bio-diesel and glycerol are free of phorbol esters. The other anti-nutritional components such as trypsin inhibitors, phytates and curcin are present in cake, so the cake should be detoxified before being used for animal feed.

Glycerin suppositories used prophylactically in premature infants (supp): A pilot randomized controlled trial.

BACKGROUND: Glycerin suppositories are often used to facilitate meconium evacuation in premature infants. The evidence for this practice is inconclusive. The purpose of this study was to assess the feasibility of a multicenter randomized controlled trial on the effectiveness of this treatment strategy. STUDY DESIGN: We conducted an external pilot study for a multicenter randomized controlled trial of premature infants randomized to glycerin suppositories or placebo procedure. Participants were included if they were gestational age of 24 weeks 0 days to 31 weeks 6 days and/or birthweight of 500 to 1500 grams. We excluded infants with life-threatening congenital anomalies, contraindications to receiving suppositories, or signs of clinical instability. Outcomes included cost, recruitment, and treatment-related adverse events. RESULT: A total of 109 were screened, 79 were initially eligible, and 34 consented to participate. Four of these infants were excluded prior to randomization due to thrombocytopenia, 30 were randomized, and 26 reached full enteral feeds. Three infants (10%) experienced rectal bleeding 5 to 43 days after completing study treatments. An anal fissure was noted in two of these patients. There were no cases of rectal perforation but one infant assigned to active treatment developed necrotizing enterocolitis. CONCLUSIONS: Conducting a multicenter randomized controlled trial on the use of glycerin suppositories in premature infants is feasible. Minor modifications to the study protocol are needed to increase participant recruitment and simplify the administration of study treatments.

Engineering NOG-pathway in Escherichia coli for poly-(3-hydroxybutyrate) production from low cost carbon sources.

Poly-(3-hydroxybutyrate) (P3HB) is a polyester with biodegradable and biocompatible characteristics suitable for bio-plastics and bio-medical use. In order to reduce the raw material cost, cheaper carbon sources such as xylose and glycerol were evaluated for P3HB production. We first conducted genome-scale metabolic network analysis to find the optimal pathways for P3HB production using xylose or glycerol respectively as the sole carbon sources. The results indicated that the non-oxidative glycolysis (NOG) pathway is important to improve the product yields. We then engineered this pathway into E. coli by introducing foreign phophoketolase enzymes. The results showed that the carbon yield improved from 0.19 to 0.24 for xylose and from 0.30 to 0.43 for glycerol. This further proved that the introduction of NOG pathway can be used as a general strategy to improve P3HB production.

A prospective cost-effectiveness study of trigeminal neuralgia surgery.

OBJECTIVES: Approximately 8000 patients with trigeminal neuralgia undergo surgery each year in the United States at an estimated cost exceeding $100 million. We compared 3 commonly performed surgeries (microvascular decompression, glycerol rhizotomy, and stereotactic radiosurgery) to evaluate the relative cost-effectiveness of these operations for patients with idiopathic trigeminal neuralgia. METHODS: Prospective nonrandomized trial at a tertiary referral center from July 1999 to December 2001. One hundred twenty-six consecutive patients underwent 153 operations (microvascular decompression, n=33; glycerol rhizotomy, n=51; stereotactic radiosurgery, n=69). Preoperative characteristics were similar between the groups with respect to sex, pain location, duration of pain, and atypical features. Facial pain outcomes were classified as excellent (no pain, no medications), good (no pain, reduced medications), fair (>50% pain reduction), and poor. The cost per quality adjusted pain-free year was compared between the groups. Mean follow-up was 20.6 months. RESULTS: Patients having microvascular decompression more commonly achieved and maintained an excellent outcome (85% and 78% at 6 and 24 months) compared with glycerol rhizotomy (61% and 55%, P=0.01) and stereotactic radiosurgery (60% and 52%, P<0.01). No difference was detected between glycerol rhizotomy and stereotactic radiosurgery (P=0.61). The cost per quality adjusted pain-free year was $6,342, $8,174, and $8,269 for glycerol rhizotomy, microvascular decompression, and stereotactic radiosurgery, respectively. Reduction in the average cost of morbidity and additional surgeries to zero did not make either microvascular decompression or stereotactic radiosurgery more cost-effective than glycerol rhizotomy. Both microvascular decompression and stereotactic radiosurgery would be more cost-effective than glycerol rhizotomy if the cost of additional surgeries after glycerol rhizotomy increased 79% and 83%, respectively. DISCUSSION: This analysis supports the practice of percutaneous surgeries for older patients with medically unresponsive trigeminal neuralgia. At longer follow-up intervals, microvascular decompression is predicted to be the most cost-effective surgery and should be considered the preferred operation for patients if their risk for general anesthesia is acceptable. More data are needed to assess the role that radiosurgery should play in the management of patients with trigeminal neuralgia.

Cost-effectiveness of Apligraf in the treatment of venous leg ulcers.

Venous ulcers are the most common chronic wounds of the lower leg. Skin substitutes recently have been introduced to stimulate nonhealing wounds. To conduct an incremental cost-effectiveness analysis, a model was developed to compare the four-layer bandage system, with and without one application of skin substitute, for the outpatient treatment of venous leg ulcers. The model estimated the costs and consequences of treatment with and without the skin substitute application. Two analytic horizons were explored: 3 months and 6 months. Determined by seven physicians, data and assumptions for the 3-month model were based on information from a clinical trial, published studies, and clinical experience. Data for the 6-month model were extrapolated from the shorter model. The model results indicate that over 3 months, the use of the skin substitute provided a benefit of 22 ulcer days averted per patient at an incremental cost of $304 (societal). The incremental cost-effectiveness ratio was $14 per ulcer day averted. Over 6 months, the incremental cost-effectiveness ratio was less than $5 per ulcer-day averted. The skin substitute plus a four-layer bandage was more costly and more effective than the four-layer bandage alone. The skin substitute is increasingly cost-effective over a longer analytic horizon and in a subgroup of patients with ulcers of long duration (greater than 1-year duration at baseline). The results come from a model that is based on a series of estimates and assumptions, and accordingly, confirmation of this finding in a prospective study is encouraged.

[Pharmacological and cost effectiveness bases of the use of categel and categel S [correction of F] in urological practice]. / Farmakoékonomicheskoe obosnovanie primeneniia preparatov katedzhel' i katedzhel' S v urologicheskoi praktike.

Preparations catedgel and catedgel S made in Austria (Montavit) was tried in Moscow hospital N 50. Categel is a sterile gel of methylcellulose with 2% lidocain and 0.05% chlorhexidine, catedgel S contains the same components but lidocain. Categel significantly reduces the risk of infectious-inflammatory complications after endourological manipulations, improves endoscopic diagnosis and makes some manipulations less painful. Comparative pharmacological cost-effect assessment of categel S and glycerine effects in prostatic transurethral resection. Categel was found 2.11 times more effective. It also improves quality of life of the patients. Categel can be recommended for wide use in urology.

Heading for an economic industrial upgrading of crude glycerol from biodiesel production to 1,3-propanediol by Lactobacillus diolivorans.

Lactobacillus diolivorans was evaluated as a potential organism for production of 1,3-propanediol under industrially relevant conditions. Crude glycerol of different origins has been tested and showed no inhibitory effects on growth or production. Using crude glycerol from biodiesel production from palm oil 85 g/l 1,3-propanediol have been obtained with a productivity of 0.45 g/lh in a fed-batch cultivation. Sugar necessary for the formation of biomass was replaced with a hydrolysate from lignocellulosic material resulting in 75 g/l 1,3-propanediol and a productivity of 0.36 g/lh. Lignocellulosic hydrolysate contained the potential inhibitors furfural and 5-hydroxymethylfurfural at concentrations of 0.7 and 0.3 g/l, respectively. Addition of furfural and 5-hydroxymethylfurfural to batch cultures in said concentrations did not show inhibitory effects on growth or 1,3-propanediol production.

Economic and environmental assessment of propionic acid production by fermentation using different renewable raw materials.

Production of propionic acid by fermentation of glycerol as a renewable resource has been suggested as a means for developing an environmentally-friendly route for this commodity chemical. However, in order to quantify the environmental benefits, life cycle assessment of the production, including raw materials, fermentation, upstream and downstream processing is required. The economic viability of the process also needs to be analysed to make sure that any environmental savings can be realised. In this study an environmental and economic assessment from cradle-to-gate has been conducted. The study highlights the need for a highly efficient bioprocess in terms of product titre (more than 100g/L and productivity more than 2g/(L · h)) in order to be sustainable. The importance of the raw materials and energy production for operating the process to minimize emissions of greenhouse gases is also shown.

Combining metabolic engineering and adaptive evolution to enhance the production of dihydroxyacetone from glycerol by Gluconobacter oxydans in a low-cost way.

Gluconobacter oxydans can rapidly and effectively transform glycerol to dihydroxyacetone (DHA) by membrane-bound quinoprotein sorbitol dehydrogenase (mSLDH). Two mutant strains of GDHE Δadh pBBR-PtufBsldAB and GDHE Δadh pBBR-sldAB derived from the GDHE strain were constructed for the enhancement of DHA production. Growth performances of both strains were largely improved after adaptively growing in the medium with glucose as the sole carbon source. The resulting GAT and GAN strains exhibited better catalytic property than the GDHE strain in the presence of a high concentration of glycerol. All strains of GDHE, GAT and GAN cultivated on glucose showed enhanced catalytic capacity than those grown on sorbitol, indicating a favorable prospect of using glucose as carbon source to reduce the cost in industrial production. It was also the first time to reveal that the expression level of the sldAB gene in glucose-growing strains were higher than that of the strains cultivated on sorbitol.

Edema control in the management of disabling chronic venous insufficiency.

This study was undertaken to assess the biomedical and socioeconomic rationale of edema control in disabling chronic venous insufficiency (CVI). In this 15-year retrospective survey (1974 through 1988) edema control was achieved by use of Unna's boot for leg ulcerations and by compressive hosiery for prevention of ulcerations. The study included 2,317 self- or physician-referred patients with disabling CVI, of whom 998 presented with venous stasis ulcers, many with recurrent ulcerations. Two hundred thirty-six patients were seen and treated only once and never returned. They were listed as not healed. Including patients who never returned after the first visit, the overall healing rate was 60.9%. Excluding the nonreturning patients, the overall rate of verified healing was 73.3%. The healing rate was 91% for first ulcers of complaint patients (patients treated at least 12 times in 32 weeks). The Unna's boot, being a functional substitute for the failing muscle pump in CVI, is a noninvasive and ambulatory method of controlling edema and treating ulcers in CVI. It does not interfere with patients' activities, it is inexpensive, and it is adaptable to middle aged and elderly ambulatory populations.