Anti-staphylococcal effects of Myracrodruon urundeuva lectins on nonresistant and multidrug resistant isolates.

AIMS: To evaluate the anti-staphylococcal effects of lectins isolated from bark (MuBL), heartwood (MuHL) and leaves (MuLL) of Myracrodruon urundeuva. METHODS AND RESULTS: The lectins were evaluated for: effects on growth, aggregation, haemolytic activity and biofilm-forming ability of Staphylococcus aureus clinical isolates nonresistant (8325-4) and multidrug resistant (LAC USA300); interference with the expression of virulence genes (hla, rnaIII and spa) of the Agr system of S. aureus; and synergistic effect with the antibiotics cefoxitin and cefotaxime. MuBL, MuHL and MuLL reduced growth (minimal inhibitory concentration (MIC): 12·5-50 µg ml-1 ) and viability (minimal bactericidal concentration (MBC): 100 µg ml-1 ) of 8325-4 and LAC USA300 cells. MuLL (at ½MIC and MIC) reduced LAC USA300 agglutination. The lectins did not interfere with haemolytic activity and expression of hla, rnaIII and spa genes. Only MuHL was able to reduce the biofilm production by 8325-4 (50-400 µg ml-1 ) and LAC USA300 (400 µg ml-1 ). CONCLUSION: The M. urundeuva lectins showed antibacterial activity against nonresistant and resistant clinical isolates of S. aureus and synergistic effects with antibiotics in reducing growth and biofilm formation. SIGNIFICANCE AND IMPACT OF THE STUDY: This work reports bioactive molecules capable of acting as anti-staphylococcal agents, since there are increasing reports of multiresistant isolates of this bacterium.

Lectins as antimicrobial agents.

The resistance of micro-organisms to antimicrobial agents has been a challenge to treat animal and human infections, and for environmental control. Lectins are natural proteins and some are potent antimicrobials through binding to carbohydrates on microbial surfaces. Oligomerization state of lectins can influence their biological activity and maximum binding capacity; the association among lectin polypeptide chains can alter the carbohydrate-lectin binding dissociation rate constants. Antimicrobial mechanisms of lectins include the pore formation ability, followed by changes in the cell permeability and latter, indicates interactions with the bacterial cell wall components. In addition, the antifungal activity of lectins is associated with the chitin-binding property, resulting in the disintegration of the cell wall or the arrest of de novo synthesis from the cell wall during fungal development or division. Quorum sensing is a cell-to-cell communication process that allows interspecies and interkingdom signalling which coordinate virulence genes; antiquorum-sensing therapies are described for animal and plant lectins. This review article, among other approaches, evaluates lectins as antimicrobials.

Multi-effect of the water-soluble Moringa oleifera lectin against Serratia marcescens and Bacillus sp.: antibacterial, antibiofilm and anti-adhesive properties.

AIMS: To evaluate the antibiofilm potential of water-soluble Moringa oleifera seed lectin (WSMoL) on Serratia marcescens and Bacillus sp. METHODS AND RESULTS: WSMoL inhibited biofilm formation by S. marcescens at concentrations lower than 2·6 µg ml-1 and impaired bacterial growth at higher concentrations, avoiding biofilm formation. For Bacillus sp., the lectin inhibited bacterial growth at all concentrations. The antibiofilm action of WSMoL is associated with damage to bacterial cells. WSMoL did not disrupt preformed S. marcescens biofilms but was able to damage cells inside them. On the other hand, the lectin reduced the number of cells in Bacillus sp. biofilm treated with it. WSMoL was able to control biofilm formation when immobilized on glass surface (116 µg cm-2 ), damaging S. marcescens cells and avoiding adherence of Bacillus sp. cells on glass. The Bacillus sp. isolate is member of Bacillus subtilis species complex and closely related to species of the conspecific 'amyloliquefaciens' group. CONCLUSION: WSMoL prevented biofilm development by S. marcescens and Bacillus sp. and the antibiofilm effect is also observed when the lectin is immobilized on glass. SIGNIFICANCE AND IMPACT OF THE STUDY: Taking together, our results provide support to the potential use of WSMoL for controlling biofilm formation by bacteria.

Water-soluble Moringa oleifera lectin interferes with growth, survival and cell permeability of corrosive and pathogenic bacteria.

AIMS: This work evaluated the antibacterial activity of a water-soluble Moringa oleifera seed lectin (WSMoL) by evaluating its effect on growth, survival and cell permeability of Bacillus sp., Bacillus cereus, Bacillus pumillus, Bacillus megaterium, Micrococcus sp., Pseudomonas sp., Pseudomonas fluorescens, Pseudomonas stutzeri and Serratia marcescens. In addition, the effect of lectin on membrane integrity of most sensitive species was also evaluated. All the tested bacteria are able to cause biocorrosion and some are also responsible for human infections. METHODS AND RESULTS: WSMoL inhibited the bacterial growth, induced agglutination and promoted the leakage of proteins from cells of all strains. Bactericidal effect was detected against Bacillus sp., B. pumillus, B. megaterium, Ps. fluorescens and Ser. marcescens. The bacteriostatic effect of lectin was evident with only 6 h of incubation. Fluorescence microscopy of Ser. marcescens showed that WSMoL caused loss of cell integrity and indicated an anti-biofilm activity of the lectin. CONCLUSIONS: WSMoL was active against the bacteria by inhibiting growth and affecting cell permeability. The lectin also interfered with membrane integrity of Ser. marcescens, the most sensitive species. SIGNIFICANCE AND IMPACT OF THE STUDY: The study indicates that WSMoL was active against bacteria that cause serious problems in both industrial and health sectors. Also, the study contributes for the 'state-of-art' on antibacterial mechanisms of lectins.

Anti-Candida activity of the water-soluble lectin from Moringa oleifera seeds (WSMoL).

This work reports the effects of the water-soluble lectin from Moringa oleifera seeds (WSMoL) on growth and survival of Candida species. In addition, cellular alterations linked to the antifungal effect were investigated. The minimal inhibitory (MIC) and fungicidal (MFC) concentrations were determined and 24-h growth curves in absence and presence of lectin were established. Flow cytometry was used to evaluate the induction of apoptosis/necrosis, alterations in mitochondrial membrane potential (ΔΨm), and occurrence of lysosomal damage. WSMoL inhibited the growth of C. albicans, C. glabrata, C. krusei and C. parapsilosis with MIC of 20µg/mL. The lowest MFC (20µg/mL) was detected for C. glabrata and the highest (80µg/mL) for C. albicans and C. parapsilosis. The inhibitory effect started from the ninth to nineteenth hour of incubation depending on the fungal species. Incubation with the lectin at the MIC for 24h increased the number of cells undergoing apoptosis and necrosis. Hyperpolarization of the mitochondrial membrane was detected after 12-h treatment, followed by reduction of ΔΨm or depolarization after 24h. No lysosomal damage was detected in treated cells. In conclusion, WSMoL is a fungistatic and fungicide agent against Candida with differential effects depending on the species.

The use of microemulsions to remove chromium from industrial sludge.

In this work microemulsion systems were used to remove chromium from leather tannery sediments. The sludge was treated by a solid-liquid extraction process (acid digestion). The effects of particle size, digestion temperature and digestion time with regards to the efficiency of chromium removal were considered. The raw sludge (3 Mesh) was dried, grounded and sieved. Particles with 3, 14, 65, 100, 200, and 325 Mesh were evaluated. Sludge digestion solutions were prepared using each studied granule size at 25 degrees C, 70 degrees C, and 95 degrees C. Microemulsion extraction experiments to remove chromium III from the acid digestion solution were made according to a Scheffé Net experimental design methodology, using microemulsion systems inside the Winsor II region (System I) and inside the microemulsion region (Winsor IV--System II). A statistical treatment was used to obtain the isoresponse plots. Chromium extraction percentages were up to 73.3% for System I and up to 93.4% for System II.

How different is the dietary pattern in non-alcoholic steatohepatitis patients?

BACKGROUND/AIMS: This study aimed at evaluating whether patients with non-alcoholic steatohepatitis (NASH) had a specific dietary pattern and how it compared with data representative from the same geographical region individuals. SUBJECTS AND METHODS: Clinical, biochemical and anthropometrics: weight, height, body mass index (BMI) and waist circumference were collected in 45 NASH patients. Diet history was assessed using a validated semi-quantitative food frequency questionnaire, analysed with the Food Processor Plus, and was compared, after adjustment for BMI, with data from a sample of 856 free-living individuals, frequency matched for sex and age. RESULTS: Patients' mean age was 49.6+/-10.6 years, 26 F: 19 M, BMI: 31.2+/-5.0 kg/m2. Comparison of their diet history with control data (C) revealed that carbohydrate consumption was lower in patients (P): P-243.6+/-5.7 g vs. C-261.5+/-1.6 g, P<0.05, and most patients had very low fibre intake. Conversely, total fat consumption was higher in patients: P-79.7+/-1.7 g vs. 73.0+/-0.4, P<0.01. A significantly higher intake of n-6 fatty acids (P=0.003) and n-6/n-3 ratio was found in patients, P<0.001. CONCLUSIONS: Our results suggest that the quality and combination of carbohydrates and fat intake may be more relevant than their isolated amount; an increased fat intake with an excessive amount of n-6 fatty acids can be implicated in promoting necro-inflammation, and provides further grounds for individualized dietary therapy.

Serum gastrin and gastrin-immunoreactive cells in the antral mucosa of patients with alcoholic liver disease.

BACKGROUND/AIMS: Hypergastrinaemia has been reported in liver cirrhosis; meanwhile, it is unclear whether it is associated with an increase in gastrin cell function. The serum gastrin concentration and the number of gastrin cells in antral biopsies were studied in patients with alcoholic liver disease. METHODS: Immunocytochemical and quantification techniques were used to localize and determine the number of gastrin cells. RESULTS: Slight non-significantly higher serum gastrin values were observed in the alcoholic liver disease patients compared with controls, but the individual variation within the groups was considerable. The frequency of gastrin cells did not differ between groups. However, the size of the gastrin cell nuclei was larger in patients with liver disease than in controls, indicating increased cellular activity. CONCLUSIONS: Alcoholic liver disease, with a disturbed liver function, influences the gastrin cells. The observed alterations may reflect the effect of alcohol and/or malnutrition, or may be secondary to the influence of liver disease on other regulatory peptides.

Non-alcoholic fatty liver: another feature of the metabolic syndrome?

BACKGROUND AND AIMS: Hepatic steatosis and nonalcoholic steatohepatitis (NASH) have been associated with obesity, non insulin-dependent diabetes mellitus and hyperlipidemia. The present study was designed in order to evaluate whether patients with steatosis/NASH presented common features with the metabolic syndrome. METHODS: In 30 patients with nonalcoholic fatty liver the prevalence of hypertension and diabetes; the glucose/insulin profile, lipid profile, and serum leptin were evaluated and correlated with body composition and energy expenditure, assessed by bioimpedance spectroscopy and indirect calorimetry, respectively. Results were compared with a group of eight controls. RESULTS: Obesity was present in 80% of patients, hypertension in 50% and non insulin dependent diabetes in 33%. Glucose metabolism was altered in 69%, with elevated insulin in 14 patients. Serum leptin, higher in women, was increased in patients: 33.9 +/- 38.9 vs 9.6 +/- 6.9 ng/ml, P< 0.05. There was a correlation between insulin and leptin, both of which correlated with body mass index, fat mass and percentage of body fat. Dyslipidaemia was found in 80% of patients: 45% presented low high density lipoproteins cholesterol, 58% high low density lipoproteins and 38% elevated very low density lipoproteins. CONCLUSIONS: There is a strong association between nonalcoholic fatty liver and features of the metabolic syndrome, suggesting a simultaneous insulin resistance and decreased sensitivity to leptin.

Long-term gallbladder stone recurrence and risk factors after successful lithotripsy.

OBJECTIVE: The risk of recurrence has limited the acceptability of conservative therapies of gallbladder stones. The aim of the present study was to determine the rate of stone recurrence and its risk factors, after successful shock-wave lithotripsy. DESIGN: Prospective ultrasound follow-up at yearly intervals or whenever biliary pain was reported. METHODS: One hundred and fifty-eight consecutive patients (single stone, n = 130; two or three stones, n = 28) were followed up to 70 months (median, 33 months) after stone disappearance and discontinuation of ursodeoxycholic acid. RESULTS: Forty-three patients developed recurrent stones. By actuarial analysis, the recurrence rates (as a percent) at 1, 2, 3, 4 and 5 years were, respectively: 6+/-2, 14+/-3, 27+/-4, 35+/-5, and 44+/-6 (observed +/- SE). Cox's regression analysis identified high body mass indexes to be a risk factor (P = 0.02) for newly formed stones. Having had a single primary stone did not seem to be protective. Fourteen of the 43 patients (33%) had early symptoms of recurrence. Thirty-eight patients (89%) chose to undergo oral dissolution again, which was complemented by lithotripsy in eight patients (19%). CONCLUSION: The 5-year gallbladder stone recurrence after lithotripsy and ursodeoxycholic acid is not substantially smaller than that reported by post-bile acid studies. Obesity is a risk factor for recurrent stones as it is for primary stones. Most patients with secondary stones choose to have conservative therapy again. Gallbladder stone recurrence still is one of the major drawbacks of these treatments and cost-effective strategies are needed to prevent it.

The changing epidemiological pattern of hepatitis A in Lisbon, Portugal.

OBJECTIVE: To evaluate the prevalence of anti-hepatitis A virus (HAV) in an urban population, in order to assess the changing epidemiological pattern of hepatitis A. SUBJECTS: We studied 325 health care workers from Santa Maria Hospital and 201 students of the Medical School of Lisbon. RESULTS: The prevalence of anti-HAV was lower in the younger age groups: 29% in the first 3 years of Faculty compared to 46% in the last 3 years, P < 0.001. The overall prevalence for students was 35%, whereas in health care workers of less than 30 years it was 65%, P < 0.001. These findings show a declining prevalence of anti-HAV, particularly in younger age groups, when compared with the results obtained in 1983, which showed a prevalence of 85%. CONCLUSION: The epidemiological pattern of hepatitis A in Lisbon, Portugal, is changing in some urban groups, with prevalences approaching those of more developed countries.

Streptococcus bovis spontaneous bacterial peritonitis in patients with alcoholic cirrhosis.

Spontaneous bacterial peritonitis (SBP) is a frequent cause of decompensated alcoholic cirrhosis. The authors describe the first two cases caused by infection with Streptococcus bovis. They suggest that this microorganism may be present in the intestinal flora of these patients more frequently than assumed. Furthermore, the course of SBP due to S. bovis may be particularly severe.

Idiopathic hypereosinophilic syndrome presenting as cholestatic liver disease.

We report the case of a 34-year-old white man with recurrent episodes of abdominal pain, cholestasis and eosinophilia. The diagnosis of idiopathic hypereosinophilic syndrome (IHS) was made after exclusion of all known causes of eosinophilia. Liver biopsy revealed an eosinophilic infiltrate with biliary damage. The patient recovered after prednisolone treatment. We review the literature on the association between IHS and liver disease.

Oropharyngeal pemphigus in a patient with chronic hepatitis C during interferon alpha-2a therapy.

There are a few reports in the literature concerning pemphigus induced by interferon given for hepatitis C. We present the case of a 28-year-old woman with post-transfusional chronic hepatitis C who developed ulcers and vesicles on her tongue, cheeks, posterior oropharynx and vocal cords 5 months after beginning treatment with recombinant interferon alpha-2a. The direct and indirect immunofluorescence was diagnostic of pemphigus vulgaris. The drug was promptly withdrawn; the patient was medicated with prednisolone and azathioprine and recovered only 3 months later. Although there are several publications describing the occurrence of other autoimmune diseases in patients receiving interferon alpha therapy, this is the first report of a pemphigus induced by interferon in hepatitis C patients involving oropharyngeal and laryngeal mucosae without cutaneous involvement.

Removal of chromium from aqueous solutions by diatomite treated with microemulsion.

In order to evaluate the sorption of heavy metals, a crude diatomite was impregnated with a microemulsion which showed remarkable increase in chromium sorption capacity as compared to untreated diatomite. Samples with two different granulometries were investigated, both yielding practically complete adsorption. The adsorption process is pH dependent and the best results for the initial Cr (III) concentration of 1.5 g/L were obtained at pH 2.95. The effect of the concentration of the chromium synthetic solution was also investigated. The adsorption isotherms were obtained (30. 40 and 50 degrees C) and the Freundlich and Langmuir models were used to determine the adsorption capacity of the adsorbent. Following the adsorption step, a desorption process was carried out using several eluant solutions. The best results were obtained using hydrochloric acid (100%) as eluant.

Heavy metals extraction by microemulsions.

The objective of this study is the heavy metal extraction by microemulsion, using regional vegetable oils as surfactants. Firstly, the main parameters, which have influence in the microemulsion region, such as: nature of cosurfactant, influence of cosurfactant (C)/surfactant (S) ratio and salinity were studied, with the objective of choosing the best extraction system. The extraction/reextraction process by microemulsion consists of two stages. In the first one, the heavy metal ion present in the aqueous phase is extracted by the microemulsion. In a second step, the reextraction process occurs: the microemulsion phase, rich in metal, is acidified and the metal is recovered in a new aqueous phase, with higher concentration. The used system had the following parameters: surfactant-saponified coconut oil; cosurfactant-n-butanol; oil phase-kerosene; C/S ratio=4; salinity-2% (NaCl); temperature of 27+/-1 degrees C; water phase-aqueous solution that varied according to the heavy metal in study (Cr, Cu, Fe, Mn, Ni and Pb). A methodology of experimental planning was used (Scheffé Net) to study the behavior of the extraction in a chosen domain. The extraction was accomplished in one step and yielded extraction percentage higher than 98% for all metals. In the reextraction HCl-8M was used as reextraction agent and the influence of the pH and time were verified. This work showed the great efficiency of the microemulsion, indicating that it is possible to extract selectively the heavy metals from the aqueous phase.

An aggressive protocol of ESWL and dissolution therapy of gallbladder stones.

OBJECTIVES: to assess the overall efficacy and which factors are independent predictors of success of ESWL and oral dissolution therapy of gallbladder stones using an aggressive protocol (high energy shock waves -median 22 Kv- and allowance to up to 6 sessions with an electro-hydraulic lithotripter). PATIENTS AND METHODS: inclusion criteria were 1) biliary pain; 2) 1 to 3 radiolucent stones or with slight calcification; 3) total stone volume under 15 cm3, equivalent to a single stone 3 cm diameter and 4) opacified cholecystography. Data was collected prospectively for 139 consecutive patients undergoing this treatment and the stone-free curves up to 12 months were analyzed as a function of age, sex, body-mass index, total stone volume, number of stones and the presence of slight calcification. RESULTS: patients underwent a mean of 2.6 sessions (range: 1-6) and 2834 shock waves (range: 589-8175). The global stone-free rate at 12 months was 54% (95% confidence interval: 45-64%). Factors that significantly -and adversely- influenced outcome were total stone volume (P < 0.001), number of stones (P = 0.005) and slight calcification (P = 0.038), using Cox's regression. Beyond significance, these three factors showed a marked effect on the stone-free curves. CONCLUSIONS: our data suggest that, even with this aggressive protocol, these factors are clearly detrimental. Thus, the results of our study agree with the current trend to restrict this combination therapy to patients with single, non-calcified stones with a small volume, or up to 2 cm diameter as is usually quoted.

Autoimmune cholangitis: case report.

We report on 2 patients who showed mixed signs of primary biliary cirrhosis and autoimmune hepatitis. Both patients were female, in their fifties (54 and 58), their laboratory tests indicated cholestasis, and a liver biopsy revealed liver cirrhosis with significant lesions of the bile ducts. Both were treated with prednisolone with their liver tests showing a rapid normalization of their aminotransferases. These patients can be considered as presenting with what is known as the overlap syndrome or autoimmune cholangitis, which has the clinical, biochemical, immunological, and histopathological characteristics of primary biliary cirrhosis and autoimmune hepatitis type I.

Hepatic stellate cell activation occurs in nonalcoholic steatohepatitis.

BACKGROUND/AIMS: Hepatic stellate cell activation has a major role in the pathogenesis of hepatic fibrosis, considered to constitute part of the healing response to a necroinflammatory stimulus. However, steatosis per se, has also been shown to induce this activation. This study evaluates if hepatic stellate cell activation is present, and how it correlates with steatosis, in nonalcoholic steatohepatitis, whose hallmark is steatosis. METHODOLOGY: Steatosis, hepatocyte damage, inflammation and fibrosis were graded from 0 to 3+, in liver biopsies from 15 well documented nonalcoholic steatohepatitis and 5 normal controls. Activated hepatic stellate cell activation were identified immunohistochemically using a monoclonal antibody raised against cytoplasmic alpha-smooth muscle actin, and semiquantitatively graded using a scoring method. RESULTS: Nonalcoholic steatohepatitis patients showed significantly greater numbers of alpha-smooth muscle actin-reactive hepatic stellate cell than controls: hepatic stellate cell index of 3.6 +/- 1.9 versus 1.5 +/- 0.5, P < 0.05. The distribution of alpha-smooth muscle actin-reactive hepatic stellate cell was higher in the perivenular areas, than in the intermediate zone and portal area, with no significant association between steatosis and alpha-smooth muscle actin-expressing hepatic stellate cell. However, a significant association was found between portal and lobular inflammation and hepatic stellate cell index, r = 0.72, P = 0.0005 and r = 0.75, P = 0.0002, respectively. CONCLUSIONS: This study demonstrates that hepatic stellate cell activation occurs in nonalcoholic steatohepatitis, clearly correlating with portal and lobular inflammation, but not with steatosis, suggesting that the mechanisms implicated in fibrosis in nonalcoholic steatohepatitis are probably related with inflammation.

Centrocytic lymphoma presenting as a subphrenic abscess and a solitary liver nodule.

Non Hodgkin's lymphoma revealed by hepatic manifestations is extremely rare. We describe here a 82-year old male patient who presented with a right subphrenic abscess and a solitary liver tumour that was shown to be a centrocytic lymphoma. Furthermore, asymptomatic cryptogenic liver cirrhosis was diagnosed. This previously unreported form of clinical presentation of a non Hodgkin's lymphoma as well as the association with liver cirrhosis are discussed in the context of the recent literature.