Renewable Energy Potential: Second-Generation Biomass as Feedstock for Bioethanol Production

Biofuels are clean and renewable energy resources gaining increased attention as a potential replacement for non-renewable petroleum-based fuels. They are derived from biomass that could either be animal-based or belong to any of the three generations of plant biomass (agricultural crops, lignocellulosic materials, or algae). Over 130 studies including experimental research, case studies, literature reviews, and website publications related to bioethanol production were evaluated; different methods and techniques have been tested by scientists and researchers in this field, and the most optimal conditions have been adopted for the generation of biofuels from biomass. This has ultimately led to a subsequent scale-up of procedures and the establishment of pilot, demo, and large-scale plants/biorefineries in some regions of the world. Nevertheless, there are still challenges associated with the production of bioethanol from lignocellulosic biomass, such as recalcitrance of the cell wall, multiple pretreatment steps, prolonged hydrolysis time, degradation product formation, cost, etc., which have impeded the implementation of its large-scale production, which needs to be addressed. This review gives an overview of biomass and bioenergy, the structure and composition of lignocellulosic biomass, biofuel classification, bioethanol as an energy source, bioethanol production processes, different pretreatment and hydrolysis techniques, inhibitory product formation, fermentation strategies/process, the microorganisms used for fermentation, distillation, legislation in support of advanced biofuel, and industrial projects on advanced bioethanol. The ultimate objective is still to find the best conditions and technology possible to sustainably and inexpensively produce a high bioethanol yield.

An Overview of the Non-Energetic Valorization Possibilities of Plastic Waste via Thermochemical Processes

The recovery and recycling/upcycling of plastics and polymer-based materials is needed in order to reduce plastic waste accumulated over decades. Mechanical recycling processes have made a great contribution to the circularity of plastic materials, contributing to 99% of recycled thermoplastics. Challenges facing this family of processes limit its outreach to 30% of plastic waste. Complementary pathways are needed to increase recycling rates. Chemical processes have the advantage of decomposing plastics into a variety of hydrocarbons that can cover a wide range of applications, such as monomers, lubricants, phase change materials, solvents, BTX (benzene, toluene, xylene), etc. The aim of the present work is to shed light on different chemical recycling pathways, with a special focus on thermochemicals. The study will cover the effects of feedstock, operating conditions, and processes used on the final products. Then, it will attempt to correlate these final products to some petrochemical feedstock being used today on a large scale.

699 Pre-Operative Screening and Investigation of Patients with Suspected Non-Alcoholic Fatty Liver Disease Among Bariatric Surgery Patients

Introduction

Non-alcoholic fatty liver disease (NAFLD) is becoming more prevalent. The investigations used to diagnose NAFLD include FIB-4 score, NAFLD score and AST/ALT ratio (AAR). Gold-standard for diagnosis is liver biopsy. Bariatric surgery reduces steatosis and fibrosis in NAFLD patients. However, in undiagnosed NAFLD, it can lead to worsening fibrosis and decompensation of cirrhosis, causing complications.

The aim is to identify how well bariatric patients are being screened for NAFLD pre-operatively.

Method

Database analysis was conducted in the bariatric clinics at Royal Derby Hospital and analysed using SPSS.

Results

392 patients’ data (Overall group) were analysed and compared with those who had an AAR>1 (Abnormal group). Abnormal group had a higher mean AAR, NAFLD and FIB-4 scores. Surprisingly, ALT and AST levels were higher in Overall group compared to Abnormal. Generally, patients were not pre-operatively checked sufficiently (81.9% LFTs, 62.2% ASTs).

Conclusions

A large number of patients could have undiagnosed NAFLD due to the lack of LFT/AST checks as ALT scores alone would miss fibrosis. Using AAR>1 and FIB-4 would allow clinicians to detect fibrosis earlier to carry out non-invasive diagnostic measures, avoiding unnecessary biopsies. Early diagnosis means patients undergoing bariatric surgery with possible cirrhosis will not experience decompensation and associated complications.

Lab-scale anaerobic digestion of cassava peels: the first step of energy recovery from cassava waste and water hyacinth

Cassava processing in Republic of Benin, which is used to produce different food products, discharges a large amount of polluting organic matter into the environment in the form of peels and wastewater. Besides, water hyacinth a rich nitrogen plant invades Benin water streams leading in aquatic ecosystem asphyxia and blocks the navigation. Both cassava wastes and water hyacinth show a high biodegradable content enable to be treated through anaerobic digestion. According to the literature, the main challenge in cassava wastes anaerobic digestion is early inhibition caused by a rapid acidification linked to low nitrogen and high biodegradable sugars content. This paper focused on the theoretical and biochemical methanogenic potential determination which is an essential step of recovery energy on large scale of both substrates. Stoichiometric methanogenic potentials of cassava wastes are close to the biochemical methanogenic potentials. However, it was necessary to treat cassava peels with potash «akanwu» and phosphate buffer pH 7.2. Average cumulative methane yield was 368 mL/gVS; 309 mL/gVS and 178 mL/gVS respectively for cassava wastewater (CWW), cassava peels (CP), water hyacinth (WH). Co-digestion of cassava peels with water hyacinth yielded on average 211 mLCH4/gVS. Despite that methane yield of co-digestion was lower than the summative methane yield of each substrate, the process has removed the chemicals products then improved cassava peels treatment. In addition, methane yield of water hyacinth increased by 10% when co-digested with cassava peels.

Characterization of Akilbenza clay from Cameroon and its performance for the removal of copper(II) ions from aqueous solution

Akilbenza clay (Akil) was characterized by XRD, FT-TIR, XRF, EDX, SEM, and N₂ gas adsorption. The adsorption performance for Cu(II) ions by this clay was also studied. Akil is composed mainly of kaolinite with mica illite and quartz as minor minerals. The ATR-FTIR analysis shows Si-O-Al, Si-O, Al-O, Si-OH, and Al-OH as the main functional groups. SEM indicates that the clay particles are irregular in shape and size by supported BJH. Akil has a specific surface area of 45.62 m²/g with the presence of both mesopores and micropores. The average pore diameter is 19.4196 nm. XRF and EDX reveal that the clay is mainly composed of silica, aluminum, and iron with a Si/Al ratio of 1.41. For the adsorption performance of Cu(II) ions, a maximum quantity of 76 mg/g was recorded. Freundlich isotherm models best describe the adsorption processes at equilibrium. Kinetic studies revealed that the adsorption process was well explained with pseudo-second-order kinetic model. The value of the mean energy of adsorption from Temkin isotherm and the values from Elovich kinetic model suggest that the adsorption of Copper(II) ions on Akil is a combination between ion exchange and electrostatic attraction. The results obtained can be introduced into the database of knowledge on clay minerals with emphasis on their use for the removal of Cu(II) ions.

Kinetic study of transesterification using particle swarm optimization method

In the present work, an optimization method called Particle Swarm Optimization (PSO) was applied to study the kinetics of alkali-catalyzed rapeseed oil transesterification, using methanol, in a batch process.

The validation of the PSO program was realized using numerical and experimental data from literature. The PSO method resulted in a 4 times lower error compared to classic methods used in the domain, which showed its efficiency and strength.

After validation, an experimental study was led on the transesterification of rapeseed oil and methanol in a batch process using KOH as catalyst (1wt/wt %) with a methanol:oil molar ratio of 6:1 at 45 °C, 55 °C and 65 °C respectively. Then, PSO was used in order to determine the reaction rate constants (kjm) of the reversible 3-steps of transesterification mechanism as well as the kinetic parameters (activation energy Ea and pre-exponential factor A).

Then, the kinetic model was used in order to investigate the effects of methanol: oil molar ratio variation (3:1, 4:1, 5:1, 6:1, 8:1, 12:1) on rate constants, yield and conversion rate at 65 °C.

The results of the simulation showed a perfect agreement with experimental results.

Guidelines for Perioperative Care in Bariatric Surgery: Enhanced Recovery After Surgery (ERAS) Society Recommendations

BACKGROUND

During the last two decades, an increasing number of bariatric surgical procedures have been performed worldwide. There is no consensus regarding optimal perioperative care in bariatric surgery. This review aims to present such a consensus and to provide graded recommendations for elements in an evidence-based "enhanced" perioperative protocol.

METHODS

The English-language literature between January 1966 and January 2015 was searched, with particular attention paid to meta-analyses, randomised controlled trials and large prospective cohort studies. Selected studies were examined, reviewed and graded. After critical appraisal of these studies, the group of authors reached a consensus recommendation.

RESULTS

Although for some elements, recommendations are extrapolated from non-bariatric settings (mainly colorectal), most recommendations are based on good-quality trials or meta-analyses of good-quality trials.

CONCLUSIONS

A comprehensive evidence-based consensus was reached and is presented in this review by the enhanced recovery after surgery (ERAS) Society. The guidelines were endorsed by the International Association for Surgical Metabolism and Nutrition (IASMEN) and based on the evidence available in the literature for each of the elements of the multimodal perioperative care pathway for patients undergoing bariatric surgery.

Antioxidant activity of milk protein hydrolysate in alloxan-induced diabetic rats

We investigated the effects of milk protein concentrate (MPC) and milk protein concentrate hydrolysate (MPCH) as antioxidant agents in rats. Six groups of healthy (non-diabetic) and type-II diabetic rats were used: (1) healthy rats (control), (2) alloxan-induced rats (diabetic control group), (3) healthy rats treated orally with MPC, (4) diabetic rats treated orally with MPC, (5) healthy rats treated orally with MPCH, and (6) diabetic rats treated orally with MPCH. We concluded that treatment with MPC or MPCH reduced the level of thiobarbituric acid reactive substances in healthy and diabetic rats. Treatment with MPC or MPCH improved activities of antioxidant enzymes (catalase, superoxide dismutase, reduced glutathione, glutathione-S-transferase, and glutathione peroxidase) in healthy and diabetic rats. From the present data, we concluded that both MPC and MPCH contain potent antioxidants and could improve the health of rats or other animals with diabetes mellitus.

PARAGON II - A single arm multicentre phase II study of neoadjuvant therapy using irinotecan bead in patients with resectable liver metastases from colorectal cancer

PURPOSE

Perioperative chemotherapy confers a 3-year progression free survival advantage following resection of colorectal liver metastases (CRLM), but is associated with significant toxicity. Chemoembolisation using drug eluting PVA microspheres loaded with irinotecan (DEBIRI) allows sustained delivery of drug directly to tumour, maximising response whilst minimising systemic exposure. This phase II single arm study examined the safety and feasibility of DEBIRI before resection of CRLM.

METHODS

Patients with resectable CRLM received lobar DEBIRI 1 month prior to surgery, with a radiological endpoint of near stasis. The trial had a primary end-point of tumour resectability (R0 resection). Secondary end-points included safety, pathologic tumour response and overall survival.

RESULTS

40 patients received DEBIRI, with a median dose of 103 mg irinotecan (range 64-175 mg). Morbidity was low (2.5%, CTCAE grade 2) with no evidence of systemic chemotoxicity. All patients proceeded to surgery, with 38 undergoing resection (95%, R0 resection rate 74%). 30-day post-operative mortality was 5% (n = 2), with neither death TACE related. 66 lesions were resected, with histologic major or complete pathologic response seen in 77.3% of targeted lesions. At median follow up of 40.6 months, 12 patients (34.3%) had died of recurrent disease with a median overall survival of 50.9 months. Nominal 1, 3 and 5-year OS was 93, 78 & 49% respectively.

CONCLUSIONS

Resection after neoadjuvant DEBIRI for CRLM is feasible and safe. Single treatment with DEBIRI resulted in tumour pathologic response and median overall survival comparable to that seen after systemic neoadjuvant chemotherapy. Registered at clinicaltrials.gov (NCT00844233).

Exposure of vancomycin-sensitive Staphylococcus aureus to subinhibitory levels of vancomycin leads to upregulated capsular gene expression

Reduced vancomycin susceptibility in Staphylococcus aureus continues to trouble clinical microbiologists and infectious disease specialists. In this study, a vancomycin-susceptible S. aureus (VSSA) strain, which was methicillin-resistant (MRSA), was grown with and without subinhibitory levels of vancomycin, and the transcriptional profiles were determined by microarray analysis. Thirty-six genes were upregulated and 42 genes were down-regulated by more than two-fold (P< or =0.05) in the presence of vancomycin. Many of these genes are involved in cell-wall biosynthesis and regulation, but of particular interest was the upregulation of genes in the locus responsible for capsule synthesis. Increased capsule production following exposure of MRSA to low levels of vancomycin could explain treatment failure. This suggests that selected genes of the capsule locus could be used as diagnostic targets for monitoring patients undergoing treatment with vancomycin therapy, as an increase in their expression may indicate progressive development of low-level resistance.

Optimization of biodiesel production from animal fat residue in wastewater using response surface methodology

Animal fat residues (AFR) from waste water were used as feedstock to produce biodiesel by a two-step acid-catalyzed process. Treatment of the AFRs with 5.4% (w/w) of 17 M H2SO4 at a methanol/AFR ratio of 13:1 (50%w/w) at 60 °C converted more than 95% of the triglycerides into fatty acid methyl esters (FAMEs) with an acid value (AV) of 1.3 mgKOH/gbiodiesel. Response surface methodology indicated that a lower AV cannot be reached using a one-step acid catalyzed process. Thus a two-step acid catalyzed process was employed using 3.6% catalyst and 30% methanol for 5 h for the first step and 1.8% catalyst and 10% methanol for 1 h in the second step, resulting in a yield higher than 98% and an AV of 0.3 mgKOH/gbiodiesel. The product thus conforms to the European norm EN14214 concerning biodiesel.

Influence of microfiltration and adjunct culture on quality of Domiati cheese

The effects of microfiltration and pasteurization processes on proteolysis, lipolysis, and flavor development in Domiati cheese during 2 mo of pickling were studied. Cultures of starter lactic acid bacteria isolated from Egyptian dairy products were evaluated in experimental Domiati cheese for flavor development capabilities. In the first trial, raw skim milk was microfiltered and then the protein:fat ratio was standardized using pasteurized cream. Pasteurized milk with same protein:fat ratio was also used in the second trial. The chemical composition of cheeses seemed to be affected by milk treatment-microfiltration or pasteurization-rather than by the culture types. The moisture content was higher and the pH was lower in pasteurized milk cheeses than in microfiltered milk cheeses at d 1 of manufacture. Chemical composition of experimental cheeses was within the legal limits for Domiati cheese in Egypt. Proteolysis and lipolysis during cheese pickling were lower in microfiltered milk cheeses compared with pasteurized milk cheeses. Highly significant variations in free amino acids, free fatty acids, and sensory evaluation were found among the cultures used in Domiati cheesemaking. The cheese made using adjunct culture containing Lactobacillus delbrueckii ssp. lactis, Lactobacillus paracasei ssp. paracasei, Lactobacillus casei, Lactobacillus plantarum, and Enterococcus faecium received high scores in flavor acceptability. Cheeses made from microfiltered milk received a higher score in body and texture compared with cheeses made from pasteurized milk.

Mucins and CD56 as markers of tumour invasion and prognosis in periampullary cancer

BACKGROUND

This study investigated the association of mucins and cluster of differentiation (CD) 56 with vascular and perineural invasion and survival in patients with periampullary cancer.

METHODS

Immunohistochemical staining was performed on formalin-fixed pancreatic tissue microarrays (cancer, chronic pancreatitis and normal pancreatic tissue) constructed from 126 pancreatic resections (cancer, 104; chronic pancreatitis, 22). Mucin (MUC) 1, MUC4 and MUC5AC expression was quantified using the immunohistochemical score (range 0-300), MUC3 expression was described as membranous or cytoplasmic, and expression of CD56, MUC2 and MUC6 as present or absent.

RESULTS

In cancers, vascular invasion correlated with overexpression (immunohistochemical score of 100 or more) of MUC1 (P = 0.003) and presence of MUC6 (P = 0.024), and perineural invasion correlated with overexpression of MUC5AC (P = 0.015). Reduced survival was observed with overexpression of MUC4 (P = 0.032) and MUC5AC (P = 0.048), membranous expression of MUC3 (P = 0.048), and presence of CD56 (P = 0.041). Perineural invasion also correlated with CD56 expression (P = 0.001). Overexpression of MUC4 and MUC5AC correlated with tumour recurrence (P = 0.001 and P = 0.034 respectively). Multivariable analysis identified membranous expression of MUC3 (P = 0.023), lymphatic invasion (P = 0.015) and perineural invasion (P = 0.004) as independent predictors of poor survival.

CONCLUSION

Mucins and CD56 may be markers of prognosis in patients with periampullary cancer.

Comparison of lateral thermal spread using monopolar and bipolar diathermy, the Harmonic Scalpel and the Ligasure

BACKGROUND

Electrosurgery for dissection and haemostasis should be associated with minimal thermal spread to surrounding tissues. This study investigated lateral thermal spread following ex vivo application of four commonly utilized instruments.

METHODS

Monopolar and bipolar diathermy (power settings 20, 30 and 40 W), the Harmonic Scalpel and Ligasure (power settings 1, 3 and 5) were studied after application to standardized porcine muscle cuts for 5, 10 or 15 s. Temperatures generated at the tips of the instruments, in the tissues adjacent to the tips and 1 cm away were recorded.

RESULTS

Following a 5-s application at the highest power setting, the highest mean(s.d.) temperatures recorded at the tips of monopolar and bipolar diathermy, Harmonic Scalpel and Ligasure instruments were 78.9(4.1), 41.9(2.2), 47.6(2.5) and 44.2(2.6) degrees C respectively. Temperatures at the instrument tips after use for 15 s remained above 42 degrees C for 55, 25, 15 and 15 s respectively. Applying monopolar diathermy (10 s at 40 W) resulted in a temperature recording of 59.2(2.2) degrees C in tissues 1 cm away from the tip of the instrument.

CONCLUSION

The degree of lateral thermal spread varied with instrument type, power setting and application time. Monopolar diathermy resulted in the highest temperatures and the greatest degree of thermal spread in tissues.

Effects of Trypanothione on the Biological Activity of Irradiated Transforming DNA

Held et al. (1984a,b) demonstrated previously that glutathione (GSH), a negatively charged thiol, is significantly less efficient in the hydrogen atom donation repair reaction with radicals induced by radiation in transforming DNA (t-DNA) than are other thiol compounds. Fahey et al. (1991a,b) postulated that the charge on thiols can influence their ability to radioprotect DNA. GSH, which is excluded from the vicinity of DNA due to its negative charge, is less protective than neutral or positively charged thiols. We have investigated this phenomenon further with trypanothione, the conjugate of glutathione and spermidine, N1,N8-bis (L-gamma-glutamyl-L-hemicystinyl-glycyl)-spermidine. Trypanothione exists in aerobic solution largely as the disulphide (T(S)2) but is maintained in the cell in the reduced form (T(SH)2) by means of an NADPH-dependent flavo-enzyme, trypanothione reductase (TR). Experimental data show that T(S)2 in the presence of TR radioprotects t-DNA in the absence of oxygen much better than GSH or spermidine alone or in combination. Little radioprotection by T(S)2 is seen when TR is not present. The results obtained with reduced trypanothione at low concentrations suggest that radioprotection of t-DNA in hypoxia occurs predominantly by H atom donation and slightly by .OH radical scavenging, and the protection is greater than that by GSH or spermidine because the polyamine moiety in trypanothione allows a greater concentration of GSH near the DNA molecule.

Early predictors of anastomotic leaks after colectomy

BACKGROUND

An anastomotic leak after colorectal surgery is associated with significant morbidity and decreased survival. Our aim was to identify the early predictors of anastomotic leaks.

METHODS

The records of patients undergoing restorative resection for colorectal disease from January 2000 to November 2005 were reviewed. Demographics, clinical events, and laboratory parameters were recorded.

RESULTS

A total of 311 patients were included. An anastomotic leak was identified in 25 patients (8%). A leak was suspected and diagnosis confirmed at a mean of 10+/-1 days postoperatively. More respiratory and neurological events occurred in patients with an anastomotic leak (p<0.001). These events occurred early in the postoperative course and were usually the first signs and symptoms of a leak. More patients with a leak had absence of bowel activity by postoperative day 6 compared to patients without a leak (p<0.0001). Elevations of the white blood cell count or temperature were a late finding.

CONCLUSION

The earliest clinical predictors of an anastomotic leak are pulmonary and/or neurological. Awareness of these findings might help in early diagnosis and treatment of an anastomotic leak.

Reduced Fat Process Cheese Made from Young Reduced Fat Cheddar Cheese Manufactured with Exopolysaccharide-Producing Cultures

In a previous study, exopolysaccharide (EPS)-producing cultures improved textural and functional properties of reduced fat Cheddar cheese. Because base cheese has an impact on the characteristics of process cheese, we hypothesized that the use of EPS-producing cultures in making base reduced fat Cheddar cheese (BRFCC) would allow utilization of more young cheeses in making reduced fat process cheese. The objective of this study was to evaluate characteristics of reduced fat process cheese made from young BRFCC containing EPS as compared with those in cheese made from a 50/50 blend of young and aged EPS-negative cheeses. Reduced fat process cheeses were manufactured using young (2 d) or 1-mo-old EPS-positive or negative BRFCC. Moisture and fat of reduced fat process cheese were standardized to 49 and 21%, respectively. Enzyme modified cheese was incorporated to provide flavor of aged cheese. Exopolysaccharide-positive reduced fat process cheese was softer, less chewy and gummy, and exhibited lower viscoelastic moduli than the EPS-negative cheeses. The hardness, chewiness, and viscoelastic moduli were lower in reduced fat process cheeses made from 1-mo-old BRFCC than in the corresponding cheeses made from 2-d-old BRFCC. This could be because of more extensive proteolysis and lower pH in the former cheeses. Sensory scores for texture of EPS-positive reduced fat process cheeses were higher than those of the EPS-negative cheeses. Panelists did not detect differences in flavor between cheeses made with enzyme modified cheese and aged cheese. No correlations were found between the physical and melting properties of base cheese and process cheese.

An “All-Comers” Venous Duplex Scan Policy for Patients with Lower Limb Varicose Veins Attending a One-stop Vascular Clinic: Is It Justified?

OBJECTIVE

To determine whether clinical assessment could predict the correct management of patients with varicose veins (VVs), select those who would need duplex scanning, and identify deep venous reflux (DVR).

METHODS

Prospective study of 342 consecutive limbs with VVs. These were divided into 3 groups: 170 (50%) limbs with primary VVs without skin changes (group I), 37 (11%) with recurrent VVs without skin changes (group II), and 135 (39%) with primary or recurrent VVs with skin changes (group III). Clinicians were asked to document whether they would normally request a duplex scan because of clinical uncertainty. Agreement between decision-making based on clinical and on duplex findings was documented.

RESULTS

Agreement between clinical and duplex findings for groups I, II, and III was 82%, 59%, and 67%, respectively. In 112 cases (66%) in group I, clinicians felt certain about the diagnosis and yet duplex scanning revealed they were wrong in 12% of cases. In group II, clinicians would request a duplex scan because of clinical uncertainty in 30 (81%) cases. In group III, the sensitivity, specificity, positive and negative predictive value of clinical assessment in detecting DVR was 32%, 77%, 24%, and 83%, respectively.

CONCLUSIONS

Clinical evaluation of patients with VVs is unreliable in planning their management. Clinicians can neither predict those who will require duplex scanning nor correctly identify DVR. Even experienced surgeons often "get it wrong" when assessing primary uncomplicated veins despite being certain about the diagnosis. Therefore, an "all-comers" duplex imaging policy should be implemented if optimal management is to be achieved.

Application of exopolysaccharide-producing cultures in reduced-fat Cheddar cheese: cryo-scanning electron microscopy observations

The microstructure of reduced- and full-fat Cheddar cheeses made with exopolysaccharide (EPS)-producing and nonproducing cultures was observed using cryo-scanning electron microscopy. Fully hydrated cheese samples were rapidly frozen in liquid nitrogen slush (-207 degrees C) and observed in their frozen hydrated state without the need for fat extraction. Different EPS-producing cultures were used in making reduced-fat Cheddar cheese. Full-fat cheese was made with a commercial EPS-nonproducing starter culture. The cryo-scanning electron micrographs showed that fat globules in the fully hydrated cheese were surrounded by cavities. Serum channels and pores in the protein network were clearly observed. Young (1-wk-old) full-fat cheese contained wide and long fat serum channels, which were formed because of fat coalescence. Such channels were not observed in the reduced-fat cheese. Young reduced-fat cheese made with EPS-nonproducing cultures contained fewer and larger pores than did reduced-fat cheese made with a ropy strain of Lactococcus lactis ssp. cremoris (JFR1), which had higher moisture levels. A 3-dimensional network of EPS was observed in large pores in cheese made with JFR1. Major changes in the size and distribution of pores within the structure of the protein network were observed in all reduced-fat cheeses, except that made with JFR1, as they aged. Changes in porosity were less pronounced in both the full-fat and the reduced-fat cheeses made with JFR1.

The impact of diabetes on current revascularisation practice and clinical outcome in patients with critical lower limb ischaemia

OBJECTIVE

To compare current revascularisation practice and outcome in diabetic and non-diabetic patients presenting with critical limb ischaemia (CLI) to a single vascular surgeon.

METHODS

Data for 113 patients presenting with CLI were collected prospectively over a 3-year period. Forty-four (39%) were diabetic. Treatment was classified as percutaneous angioplasty, arterial reconstruction, primary major amputation, and conservative therapy. Main outcome measures were 30-day mortality, major amputation, survival, and amputation-free survival.

RESULTS

Diabetic patients were more likely to present with gangrene, give a history of angina, be treated with nitrates and statins, and have lower cholesterol levels. No significant differences were found in the initial treatment options between diabetics and non-diabetics: angioplasty 39 vs 26%, surgical revascularisation 34 vs 33%, primary major amputation 9% vs 17%, and conservative treatment 11 vs 19% (p = ns in all). There were eight deaths (7%) within 30-days. At follow-up (1-44 months, median 14 months), rates of major amputation and death for the entire population were 23 and 8%, respectively. The 12-month cumulative survival and amputation-free survival rates were 90 and 72%, respectively. When comparing diabetic to non-diabetic patients, there were no significant differences in the 30-day mortality (6.8 vs 7.2%, p = 0.4), cumulative survival (93 vs 89% at 12 months, log-rank test: 0.00, p = 0.9), amputation-free survival (71 vs 73% at 12 months, log-rank test: 0.00, p = 0.99), and major amputation rates (22.7 vs 23.1% at 12 months, p = 0.96). Similarly, there were no differences in limb salvage rates between diabetic and non-diabetic patients undergoing revascularisation procedures (78 vs 90% at 12 months, log-rank test: 2.04, p = 0.15).

CONCLUSIONS

In current practice, an aggressive multidisciplinary approach in diabetic patients presenting with CLI leads to similar limb salvage, amputation-free survival, mortality, and major amputation rates to those seen in non-diabetic patients. The presence of diabetes should not deter clinicians from attempting revascularisation by means of angioplasty or surgical reconstruction.

Application of Exopolysaccharide-Producing Cultures in Reduced-Fat Cheddar Cheese: Texture and Melting Properties

Textural, melting, and sensory characteristics of reduced-fat Cheddar cheeses made with exopolysaccharide (EPS)-producing and nonproducing cultures were monitored during ripening. Hardness, gumminess, springiness, and chewiness significantly increased in the cheeses as fat content decreased. Cheese made with EPS-producing cultures was the least affected by fat reduction. No differences in hardness, springiness, and chewiness were found between young reduced fat cheese made with a ropy Lactococcus lactis ssp. cremoris [JFR1; the culture that produced reduced-fat cheese with moisture in the nonfat substance (MNFS) similar to that in its full-fat counterpart] and its full-fat counterpart. Whereas hardness of full-fat cheese and reduced-fat cheese made with JFR1 increased during ripening, a significant decrease in its value was observed in all other cheeses. After 6 mo of ripening, reduced fat cheeses made with all EPS-producing cultures maintained lower values of all texture profile analysis parameters than did those made with no EPS. Fat reduction decreased cheese meltability. However, no differences in meltability were found between the young full-fat cheese and the reduced-fat cheese made with the ropy culture JFR1. Both the aged full- and reduced-fat cheeses made with JFR1 had similar melting patterns. When heated, they both became soft and creamy without losing shape, whereas reduced-fat cheese made with no EPS ran and separated into greasy solids and liquid. No differences were detected by panelists between the textures of the full-fat cheese and reduced-fat cheese made with JFR1, both of which were less rubbery or firm, curdy, and crumbly than all other reduced-fat cheeses.

Application of Exopolysaccharide-Producing Cultures in Reduced-Fat Cheddar Cheese: Composition and Proteolysis

Proteolysis during ripening of reduced fat Cheddar cheeses made with different exopolysaccharide (EPS)-producing and nonproducing cultures was studied. A ropy strain of Lactococcus lactis ssp. cremoris (JFR1) and capsule-forming nonropy and moderately ropy strains of Streptococcus thermophilus were used in making reduced-fat Cheddar cheese. Commercial Cheddar starter was used in making full-fat cheese. Results showed that the actual yield of cheese made with JFR1 was higher than that of all other reduced-fat cheeses. Cheese made with JFR1 contained higher moisture, moisture in the nonfat substance, and residual coagulant activity than all other reduced-fat cheeses. Proteolysis, as determined by PAGE and the level of water-soluble nitrogen, was also higher in cheese made with JFR1 than in all other cheeses. The HPLC analysis showed a significant increase in hydrophobic peptides (causing bitterness) during storage of cheese made with JFR1. Cheese made with the capsule-forming nonropy adjunct of S. thermophilus, which contained lower moisture and moisture in the nonfat substance levels and lower chymosin activity than did cheese made with JFR1, accumulated less hydrophobic peptides. In conclusion, some EPS-producing cultures produced reduced-fat Cheddar cheese with moisture in the nonfat substance similar to that in its full-fat counterpart without the need for modifying the standard cheese-making protocol. Such cultures might accumulate hydrophobic (bitter) peptides if they do not contain the system able to hydrolyze them. For making high quality reduced-fat Cheddar cheese, EPS-producing cultures should be used in conjunction with debittering strains.

Effects of Exopolysaccharide-Producing Cultures on the Viscoelastic Properties of Reduced-Fat Cheddar Cheese

The objective was to study the influence of different exopolysaccharide (EPS)-producing and nonproducing lactic cultures on the viscoelastic properties of reduced-fat Cheddar cheese. Changes in the viscoelastic properties were followed over a ripening period of 6 mo. Results showed that the elastic, viscous, and complex moduli were higher in reduced-fat cheeses made with EPS-nonproducing cultures than in full-fat cheese. No differences in the viscoelastic properties were found between young reduced-fat cheese made with a ropy strain of Lactococcus lactis ssp. cremoris (JFR1) and its full-fat counterpart. Interestingly, the changes in viscoelastic moduli in both full-fat cheese and reduced-fat cheese made with JFR1 during ripening followed the same pattern. Whereas the moduli increased during the first month of ripening in those 2 cheeses, a dramatic decrease was observed in all other cheeses. Slopes of the viscoelastic moduli as a function of frequency were lower in the full-fat than in reduced-fat cheeses. The creep test showed that fresh reduced-fat cheese made with JFR1 was less rigid and more deformable than that made with EPS-nonproducing cultures. The creep and recovery properties of young reduced-fat cheese made with JFR1 and the full-fat type were similar. No differences were found in the viscoelastic properties between reduced-fat cheese made with no EPS and those made with EPS-producing adjunct cultures of Streptococcus thermophilus. After 6 mo of ripening, cheeses made with EPS-producing cultures maintained lower elastic and viscous moduli than did those made with no EPS.

In vivo transfection of a cis element 'decoy' against signal transducers and activators of transcription 6 (STAT6)-binding site ameliorates IgE-mediated late-phase reaction in an atopic dermatitis mouse model

Signal transducers and activators of transcription 6 (STAT6) play a crucial role in the transactivation of IL-4 and IL-13, which might be involved in the pathogenesis of atopic dermatitis (AD). We herein reported that the IgE-mediated late-phase reaction significantly decreased in STAT6-deficient (STAT6(-/-)) mice in AD model mice induced by intravenous injection of monoclonal anti-dinitrophenyl (DNP)-IgE antibody and subsequent skin testing with dinitrofluorobenzene. We therefore hypothesized that synthetic double-stranded DNA with a high affinity for STAT6 could be introduced in vivo as decoy cis elements to bind the transcriptional factor and block the gene activation contributing to the onset and progression of AD, thus providing effective therapy for AD. Treatment by the transfection of STAT6 decoy oligodeoxynucleotides (ODNs), but not scramble decoy ODN after sensitization by anti-DNP-IgE antibody, had a significant inhibitory effect on not only STAT6 binding to nuclei but also on the late-phase response. A histological analysis revealed that both edema and the infiltration of neutrophils and eosinophils significantly decreased in STAT6 decoy ODN-transfected mice. To examine the mechanism of the in vivo effect of STAT6 decoy ODN, we employed an in vitro mast cells culture system. After IgE receptor engagement, mast cells transfected by STAT6 decoy ODN exhibited normal histamine release, but their cytokine release (TNF-alpha, IL-6) markedly decreased. We herein report the first successful in vivo transfer of STAT6 decoy ODN to reduce the late-phase reaction, thereby providing a new therapeutic strategy for AD.

Determination of lesion size by ultrasound during radiofrequency catheter ablation

The catheter tip temperature that is used to control the radiofrequency generator output poorly correlates to lesion size. We, therefore, evaluated lesions created in vitro using a B-mode ultrasound imaging device as a potential means to assess lesion generation during RF applications non-invasively. Porcine ventricular tissue was immersed in saline solution at 37 degrees C. The catheter was fixed in a holder and positioned in a parallel orientation to the tissue with an array transducer (7.5 MHz) app. 3 cm above the tissue. Lesions were produced either in a temperature controlled mode with a 4-mm tip catheter with different target temperatures (50, 60, 70 and 80 degrees C, 80 W maximum output) or in a power controlled mode (25, 50 and 75 W, 20 ml/min irrigation flow) using an irrigated tip catheter. Different contact forces (0.5 N, 1.0 N) were tested, and RF was delivered for 60 s. A total of 138 lesions was produced. Out of these, 128 could be identified on the ultrasound image. The lesion depth and volume was on average 4.1 +/- 1.6 mm and 52 +/- 53 mm3 as determined by ultrasound and 3.9 +/- 1.7 mm and 52 +/- 55 mm3 as measured thereafter, respectively. A linear correlation between the lesion size determined by ultrasound and that measured thereafter was demonstrated with a correlation coefficient of r = 0.87 for lesion depth and r = 0.93 for lesion volume. We conclude that lesions can be assessed by B-mode ultrasound imaging.

Laparoscopic ventral hernia repair during the learning curve

Large series of laparoscopic ventral hernia repair have shown excellent results. However, published comparative studies have had conflicting outcomes. We retrospectively reviewed the first 29 laparoscopic ventral hernia repairs performed at a VA Medical Center from January 2000 to June 2001. The outcome was compared to that of open repairs performed during the same time period. Outcomes between the groups were similar in all respects, except for the length of stay. The conversion rate for the laparoscopic approach was 13.8%. There was one death in the laparoscopic group due to an unrecognized enterotomy. There were three recurrences in the open group and one in the laparoscopic group with a mean follow up of 13 months. In our series, laparoscopic hernia repair resulted in a shorter hospital stay but no other significant benefits, along with a risk of missed enterotomy. The risk-benefit ratio for this procedure may be high during the learning curve.

Effect of pharmacotechnical design on the in vitro interaction of ketoconazole tablets with non-systemic antacids

In certain polytherapy programs, ketoconazole can be administered with some antacids that could modify its dissolution rate and reduce its absorption leading to therapeutic failures. The aim of this work was to evaluate the influence of some excipients on this interaction in vitro. In this way, six formulations of directly compressible ketoconazole tablets were developed. The results confirmed that the dissolution rate of ketoconazole tablets was significantly reduced in the presence of antacids. Nevertheless this interaction was remarkably avoided in some of the formulations checked and in some conditions. In this way, the inclusion of a disintegrant (sodium starch glycolate) not only increased the dissolution rate of ketoconazole in the tablets, as expected, but it also modified the degree in which the dissolution rate was decreased in the presence of antacids. It was proved that a suitable selection of the excipients and therefore the modification in the rate in which the drug was released, could play an important role to modify a pharmacokinetic interaction based on a reduction of the solubility of the drug as a function of the pH value of the medium.

Quantitative assessment of fibrosis and steatosis in liver biopsies from patients with chronic hepatitis C

BACKGROUND

Hepatic fibrosis is one of the main consequences of liver disease. Both fibrosis and steatosis may be seen in some patients with chronic hepatitis C and alcoholic liver disease (ALD).

AIMS

To quantitate fibrosis and steatosis by stereological and morphometric techniques in patients with chronic hepatitis C and compare the results with a control group of patients with ALD. In addition, to correlate the quantitative features of fibrosis with the Ishak modified histological score.

MATERIALS AND METHODS

Needle liver biopsies from 86 patients with chronic hepatitis C and from 32 patients with alcoholic liver disease (disease controls) were analysed by stereological and morphometric analyses using the Prodit 5.2 system. Haematoxylin and eosin and Picro-Mallory stained sections were used. The area fractions (A(A)) of fibrosis, steatosis, parenchyma, and other structures (bile duct and central vein areas) were assessed by stereological method. The mean diameters of fat globules were determined by morphometric analysis.

RESULTS

Significant differences were found in the A(A) of fibrosis, including fibrosis within portal tract areas, between chronic hepatitis C patients and those with ALD (mean (SD): 19.14 (10.59) v 15.97 (12.51)). Portal and periportal (zone 1) fibrosis was significantly higher (p = 0.00004) in patients with chronic hepatitis C compared with the control group (mean (SD): 9.04 (6.37) v 3.59 (3.16)). Pericentral fibrosis (zone 3) occurred in both groups but was significantly more pronounced in patients with ALD. These results correlate well with the modified Ishak scoring system. However, in patients with cirrhosis (stage 6) with chronic hepatitis C the A(A) of fibrosis varied between 20% and 74%. The diameter of fat globules was significantly lower in patients with hepatitis C (p = 0.00002) than the ALD group (mean (SD): 14.44 (3.45) v 18.4 (3.32)). Microglobules were more frequent in patients with chronic hepatitis C than in patients with ALD. In patients with chronic hepatitis C, the fat globules had a zonal distribution in comparison with pan steatosis in ALD.

CONCLUSION

Quantitative, stereological techniques are simple and reliable for evaluating hepatic fibrosis and steatosis in chronic hepatitis C. They are most useful for assessing the origin, location, and the stage of fibrosis. Stereology and morphometry are recommended for the quantitation of fibrosis and steatosis, particularly for the evaluation of new treatment strategies in patients with chronic hepatitis C.