Therapy of experimental NASH and fibrosis with galectin inhibitors

Non-alcoholic steatohepatitis (NASH) and resultant liver fibrosis is a major health problem without effective therapy. Some data suggest that galectin-3 null mice are resistant to the development of NASH with fibrosis. We examined the ability of two complex carbohydrate drugs that bind galectin-3, GM-CT-01 and GR-MD-02, to treat NASH with fibrosis in a murine model. GR-MD-02 treatment resulted in marked improvement in liver histology with significant reduction in NASH activity and collagen deposition. Treatments seemed also to improve both glomerulopathy and interstitial fibrosis observed in kidneys. The improvement in liver histology was evident when animals were treated early in disease or after establishment of liver fibrosis. In all measures, GM-CT-01 had an intermediate effect between vehicle and GR-MD-02. Galectin-3 protein expression was increased in NASH with highest expression in macrophages surrounding lipid laden hepatocytes, and reduced following treatment with GR-MD-02, while the number of macrophages was unchanged. Treatment with GR-MD-02 also reduced the expression of pathological indicators including iNOS, an important TH1 inflammatory mediator, CD36, a scavenger receptor for lipoproteins on macrophages, and α-smooth muscle actin, a marker for activated stellate cells which are the primary collagen producing cells in liver fibrosis. We conclude that treatment with these galectin-3 targeting drugs improved histopathological findings of NASH and markedly reduced fibrosis in a murine model of NASH. While the mechanisms require further investigation, the treatment effect is associated with a reduction of galectin-3 expressed by activated macrophages which was associated with regression of NASH, including hepatocellular fat accumulation, hepatocyte ballooning, intra-portal and intra-lobular inflammatory infiltrate, and deposition of collagen. Similar effects were found with GM-CT-01, but with approximately four-fold lower potency than GR-MD-02. The results, in combination with previous experiments in toxin-induced fibrosis, suggest that these galectin-targeting drugs may have potential in human NASH with fibrosis.

In VitroCytotoxic Effects of Stabilizing Sugars within Human Intravenous Immunoglobulin Preparations against the Human Macrophage THP-1 Cell-line

Intravenous immunoglobulin (IVIg) is a safe and effective therapy for the treatment of primary and secondary humoral immune deficiencies and autoimmune disorders. Both minor and more serious side effects may occur following IVIg administration in approximately 1-15% of infusions and stabilizing sugars found in IVIg preparations may contribute some of these. In this report, we aimed to determine the cytotoxic effects of IVIg as compared with four stabilizing sugars (glucose, sucrose, maltose and D-sorbitol) found in IVIg preparations on human monocyte-macrophages. The human THP-1 macrophage cell-line was used as a model to determine the effects of stabilizing sugars and IVIg preparations on cell viability and growth. The sugars differentially affected the viability of THP-1 cells. In experiments using doses of the sugars commonly found in IVIg preparations, cell viability and proliferation was unaffected when compared with doses of IVIg typically administered to patients (5 mg/ml). However, in an LDH-release cell lysis assay that measures changes in cell permeability, glucose (50 mg/ml) induced significant release of LDH as compared with complete IVIg (5 mg/ml, p<0.0001). Intranucleosomal DNA fragmentation was not detected at therapeutically relevant doses of IVIg. This suggested that THP-1 cell death was not due to apoptosis. We conclude that osmotic stress mediated by the sugars at high doses promoted THP-1 cell death. We propose that IVIg per se is not cytotoxic to the autonomously growing human THP-1 cell-line but rather, the stabilizing sugars used in the preparations are the cytotoxic factors. This observation was evident when preparations of IVIg were used at high concentrations but not at levels one would associate with clinically relevant doses of IVIg.

Microbial colonization and their relation with potential cofactors in patients with denture stomatitis

AIM

To determine microbial prevalence in the mucous membrane and prosthesis of denture wearers with and without denture stomatitis and to study its relationship with potential clinical cofactors.

MATERIALS AND METHODS

Saliva was collected from 200 patients (100 female and 100 male) wearing dental prosthesis for measurement of pH. Oral samples of the mucous membrane and of dentures were taken with sterile swab for microbiological analysis. Medical and dietary history of the subjects was recorded. Chi-square test and analysis of varience were used for statistical analysis.

RESULTS

Diabetes, hypertension and high carbohydrate ingestion was observed in majority of patients. The pH average in saliva was of 5.1. The presence of C. albicans, S. aureus and S. mutans in the mucous membrane was of 55.4, 56.4 and 63.6% respectively. C. albicans was isolated in 69.7% from the prosthesis, whereas S. aureus and S. mutans were isolated in 45.3%. The isolation of C.albicans was more frequent in patients with denture stomatitis.

CONCLUSION

C. albicans, S. aureus and S. mutans frequently colonize the oral mucous of denture wearers. This is more frequently observed in patients with denture stomatitis.

CLINICAL SIGNIFICANCE

Denture stomatitis is associated to Candida albicans, different bacteria and other cofactors, such as salivary pH, carbohydrate ingestion, systemic illnesses and medication.

[Sugar substitute products impact on oral fluid biochemical properties]

Sugar substitute products impact on oral fluid protein and carbohydrate content, as well as oxidative balance were studied in 60 medical school students in compare with conventional sugar. Sugar intake proved to cause cariesogenic carbohydrate metabolism disorders in oral fluid, intensification of lipoperoxidation and decrease in antioxidation activity. Sugar substitute products help to prevent dental decay.

Effects of endotoxaemia and carbohydrate overload on glucose and insulin dynamics and the development of laminitis in horses

REASONS FOR PERFORMING STUDY

Insulin resistance (IR) is a risk factor for pasture-associated laminitis in equids and alimentary carbohydrate overload may trigger laminitis. Whether glucose metabolism responses to carbohydrate overload are more pronounced in insulin-resistant horses requires further study.

HYPOTHESIS

Horses pretreated with endotoxin to alter insulin sensitivity differ significantly in their glucose and insulin responses to carbohydrate overload.

METHODS

Horses (n=24) were divided into 3 groups. A lipopolysaccharide (LPS; n=8) group that received endotoxin as an 8 h 7.5 ng/kg bwt/h i.v. continuous rate infusion, an oligofructose (OF; n=8) group that received an infusion of saline followed by 5 g/kg bwt OF via nasogastric intubation, and a LPS/OF (n=8) group that received LPS followed 16 h later by OF. Glucose and insulin dynamics were evaluated at -24 h and 48 h using the frequently sampled i.v. glucose tolerance test and minimal model analysis. Physical examinations and haematology were performed and the severity of laminitis assessed.

RESULTS

Horses receiving LPS developed leucopenia and both LPS and OF induced clinical signs consistent with systemic inflammation. Insulin sensitivity significantly decreased (P < 0.001) over time, but responses did not differ significantly among groups. Time (P < 0.001) and treatment x time (P = 0.038) effects were detected for the acute insulin response to glucose, with mean values significantly increasing in LPS and LPS/OF groups, but not the OF group. Five horses in the LPS/OF group developed clinical laminitis compared with 0 and 2 horses in the LPS and OF groups, respectively.

CONCLUSIONS

Endotoxaemia and carbohydrate overload reduce insulin sensitivity in horses. Endotoxin pretreatment does not affect the alterations in glucose metabolism induced by carbohydrate overload.

POTENTIAL RELEVANCE

Insulin sensitivity decreases after carbohydrate overload in horses, which may be relevant to the development of pasture-associated laminitis.

[Food intake and colorectal cancers; an ecological study in Romania]

The aim of the present study performed in a Romanian population was to identify the food which can be either associated with or protect against colorectal carcinoma.

MATERIAL AND METHOD

Correlation and regression analysis were used to examine the association between dietary intake and the rate of incidence for colon, rectum and anus cancers, in study groups from 7 regions of Romania.

RESULTS

A strong and positive association was observed for colonic cancer and the intake of coffee, tea and cocoa (r = 0.77, p = 0.042) whereas statistical significance of borderline value was found for margarine (r = 0.73, p = 0.06) and sweets (r = 0.74, p = 0.066) intake. A potential protective effect can be attributed to wine consumption ( r = -0.75, p = 0.03). The malignancies of the rectum and anus showed both a strong positive correlation with the intake of red meat ( r = 0.76, p = 0.048), sausages ( r = 0.87, p = 0.012), margarine (r = 0.97, p = 0.0004), butter ( r = 0.76, p = 0.049), sweets ( r = 0.93, p = 0.003), beverages (r = 0.97, p = 0.0003), coffee, tea, cocoa ( r = 0.94, p = 0.002). Negative correlations were reported for the recto-anal cancer and the consumption of: fish (r = -0.8, p = 0.032), cheese (r = -0.9, p = 0.006), wine (r = -0.85, p = 0.015).

CONCLUSION

The need for reducing the dietary intake of margarine, red meat, sausages and sweets while the beneficial effects of wine consumption have been also confirmed.

Effect of a carbohydrate mouthwash on running time-trial performance

The aim of the present study was to determine the effect of a carbohydrate mouthwash on running time-trial performance. On two separate occasions, seven recreationally active males (VO2max 57.8 ml x kg(-1) x min(-1), s = 3.7) completed a preloaded (15 min at 65%VO2max) time-trial of 45 min in duration on a motorized treadmill. At 6-min intervals during the preload and time-trial, participants were given either a 6% maltodextrin, 3% lemon juice solution (carbohydrate trial) or a 3% lemon juice placebo mouthwash (placebo trial) in a double-blind, randomized crossover design. Heart rate, oxygen consumption (VO2), respiratory exchange ratio (RER), and ratings of perceived exertion (RPE) were measured during the preload, and blood glucose and lactate were measured before and after the preload and time-trial. There were no significant differences in distance covered between trials (carbohydrate: 9333 m, s = 988; placebo: 9309 m, s = 993). Furthermore, there were no significant between-trial differences in heart rate and running speed during the time-trial, or VO2, RER or RPE during the preload. Blood lactate and glucose increased as a result of the exercise protocol, with no between-trial differences. In conclusion, there was no positive effect of a carbohydrate mouthwash on running performance of approximately 1 h duration.

Serial alterations in digital hemodynamics and endothelin-1 immunoreactivity, platelet-neutrophil aggregation, and concentrations of nitric oxide, insulin, and glucose in blood obtained from horses following carbohydrate overload

OBJECTIVE

To quantify changes in endothelium-derived factors and relate those changes to various aspects of digital hemodynamics during the prodromal stages of carbohydrate overload (CHO)-induced laminitis in horses.

ANIMALS

20 adult horses without abnormalities of the digit.

PROCEDURES

Digital and jugular venous blood samples were collected at 1-hour intervals (for assessment of endothelin-1 [ET-1] immunoreactivity and measurement of glucose, insulin, and nitric oxide [NO] concentrations) or 4-hour intervals (CBC and platelet-neutrophil aggregate assessment) for 8 hours or 16 hours after induction of CHO-associated laminitis in horses treated with an ET-1 antagonist. Effects of treatment, collection site, and time and the random effects of horse on each variable were analyzed by use of a repeated-measures model. Where treatment and collection site had no significant effect, data were combined.

RESULTS

Compared with baseline values, CHO resulted in changes in several variables, including a significant increase from baseline in digital blood ET-like immunoreactivity at 11 hours; digital blood ET-like immunoreactivity was significantly greater than that in jugular venous blood at 8, 9, 11, and 12 hours. Digital and jugular venous blood concentrations of glucose increased from baseline significantly at 3, 4, and 5 hours; insulin concentration increased significantly at 5 hours; and the number of platelet-neutrophil aggregates increased significantly at 12 hours.

CONCLUSIONS AND CLINICAL RELEVANCE

In horses, concurrent increases in venous blood ET-1 immunoreactivity, insulin and glucose concentrations, and platelet-neutrophil aggregates support a role of endothelial dysfunction in the pathogenesis of CHO-induced laminitis.

Effects of an endothelin receptor antagonist and nitroglycerin on digital vascular function in horses during the prodromal stages of carbohydrate overload-induced laminitis

OBJECTIVE

To evaluate changes in digital vascular function in horses with carbohydrate overload (CHO)-induced laminitis and determine the effects of an endothelin (ET) receptor antagonist and nitroglycerin on laminitis-associated vascular dysfunction.

ANIMALS

20 adult horses without abnormalities of the digit.

PROCEDURES

Hemodynamic variables were recorded before (baseline) and hourly after all horses were administered a CHO ration via nasogastric tube. In 4 groups of 5 horses each, saline (0.9% NaCl) solution or ET receptor antagonist (10(5)M in digital blood) was administered into the digital arterial circulation according to 1 of 2 schedules. During anesthesia, blood flow; arterial, venous, and capillary pressures; and total, precapillary, and postcapillary resistances were measured in an isolated perfused digit of each horse. In all groups, nitroglycerin was infused (10(5)M in digital blood), and digital microvascular assessments were repeated.

RESULTS

The CHO caused a significant decrease in right atrial pressure by 14 hours that was not affected by administration of saline solution or ET receptor antagonist. In isolated digits of anesthetized horses, CHO resulted in a significant decrease in digital blood flow associated with a significant increase in total and postcapillary resistances. Treatment with the ET receptor antagonist and nitroglycerin caused a significant decrease in total resistance. Postcapillary resistance was significantly decreased following treatment with the ET receptor antagonist but was not altered by treatment with nitroglycerin.

CONCLUSIONS AND CLINICAL RELEVANCE

Treatment with an ET receptor antagonist and nitroglycerin resulted in significant improvement in vascular resistance in isolated perfused digits of anesthetized horses with CHO-induced laminitis.

Anti-oxidative effects of pomegranate juice (PJ) consumption by diabetic patients on serum and on macrophages

Diabetes is associated with increased oxidative stress and atherosclerosis development. In the present study, we investigated the effects of pomegranate juice (PJ; which contains sugars and potent anti-oxidants) consumption by diabetic patients on blood diabetic parameters, and on oxidative stress in their serum and macrophages. Ten healthy subjects (controls) and 10 non-insulin dependent diabetes mellitus (NIDDM) patients who consumed PJ (50ml per day for 3 months) participated in the study. In the patients versus controls serum levels of lipid peroxides and thiobarbituric acid reactive substances (TBARS) were both increased, by 350% and 51%, respectively, whereas serum SH groups content and paraoxonase 1 (PON1) activity, were both decreased (by 23%). PJ consumption did not affect serum glucose, cholesterol and triglyceride levels, but it resulted in a significant reduction in serum lipid peroxides and TBARS levels by 56% and 28%, whereas serum SH groups and PON1 activity significantly increased by 12% and 24%, respectively. In the patients versus controls monocytes-derived macrophages (HMDM), we observed increased level of cellular peroxides (by 36%), and decreased glutathione content (by 64%). PJ consumption significantly reduced cellular peroxides (by 71%), and increased glutathione levels (by 141%) in the patients' HMDM. The patients' versus control HMDM took up oxidized LDL (Ox-LDL) at enhanced rate (by 37%) and PJ consumption significantly decreased the extent of Ox-LDL cellular uptake (by 39%). We thus conclude that PJ consumption by diabetic patients did not worsen the diabetic parameters, but rather resulted in anti-oxidative effects on serum and macrophages, which could contribute to attenuation of atherosclerosis development in these patients.

Drug-induced disorders of teeth

It is essential that every health care professional who is involved with the prescription or recommendation of drugs be fully aware of any resultant disorders that may arise as a side-effect. A range of drugs can affect the teeth. In this review article, drugs that have the potential to induce changes in teeth have been classified as those leading to tooth discoloration (intrinsic and extrinsic), physical damage to tooth structure (enamel, dentin, and cementum), and alteration in tooth sensitivity.

Lactose causes heart arrhythmia in the water flea Daphnia pulex

The cladoceran Daphnia pulex is well established as a model for ecotoxicology. Here, we show that D. pulex is also useful for investigating the effects of toxins on the heart in situ and the toxic effects in lactose intolerance. The mean heart rate at 10 degrees C was 195.9+/-27.0 beats/min (n=276, range 89.2-249.2, >80% 170-230 beats/min). D. pulex heart responded to caffeine, isoproteronol, adrenaline, propranolol and carbachol in the bathing medium. Lactose (50-200 mM) inhibited the heart rate by 30-100% (K(1/2)=60 mM) and generated severe arrhythmia within 60 min. These effects were fully reversible by 3-4 h. Sucrose (100-200 mM) also inhibited the heart rate, but glucose (100-200 mM) and galactose (100-200 mM) had no effect, suggesting that the inhibition by lactose or sucrose was not simply an osmotic effect. The potent antibiotic ampicillin did not prevent the lactose inhibition, and two diols known to be generated by bacteria under anaerobic conditions were also without effect. The lack of effect of l-ribose (2 mM), a potent inhibitor of beta-galactosidase, supported the hypothesis that lactose and other disaccharides may affect directly ion channels in the heart. The results show that D. pulex is a novel model system for studying effects of agonists and toxins on cell signalling and ion channels in situ.

[Sugar and the birth of dentistry]

It took mankind some ten thousand years to get sugarcane from the Pacific to the Mediterranean. Once it reached Europe and the Europeans knew how to handle it, it took them only a hundred years to turn the production of sugar into the biggest industry of the world. Exactly in those hundred years the birth of modern medicine--and dentistry--is placed. This coincidence is too particular to be left unnoticed.

Evolutionary legacy: form of ingestion, not quantity, is the key factor in producing the effects of sugar on human health

Tens of dietary trials have been conducted to investigate the metabolic effects of sugar (sucrose) and its impact on human health. All of those studies took into account only the quantity of ingested sugar. By contrast, not a single study attempted to assess whether the form in which sugar is consumed plays a role in producing its metabolic effects. The failure of cohorts of researchers to specify how they administered sugar in their dietary trials may well explain why the results of those studies are extremely contradictory. These discrepant findings, understandably, resulted in conflicting opinions about sugar and in divergent guidelines about its recommended consumption. The evolutionary line of reasoning expounded in this article leads to conclude that the form in which sugar is ingested, not its quantity, constitutes the most important factor in producing the metabolic effects of sugar and its impact on human health. As a consequence, for example, the consumption of 100 g of sugar per day can be either detrimental or innocuous, depending on the form in which sugar is ingested. Specifically, the evolutionary hypothesis advanced in this paper implies that sugar can predispose to type 2 diabetes and can cause unhealthy changes in blood lipids if it is consumed in solid forms or in dense solutions containing more than 250 g/L, whereas sugar is harmless if it is consumed in more dilute concentrations. This evolutionary hypothesis, in view of its intuitively far-reaching clinical implications, should be tested by at least one dietary trial.

Sugars: hedonic aspects, neuroregulation, and energy balance

The prevalence of obesity has increased dramatically in recent years in the United States, with similar patterns seen in several other countries. Although there are several potential explanations for this dramatic increase in obesity, dietary influences are a contributing factor. An inverse correlation between dietary sugar intake and body mass index has been reported, suggesting beneficial effects of carbohydrate intake on body mass index. In this review we discuss how sugars interact with regulatory neurochemicals in the brain to affect both energy intake and energy expenditure. These neurochemicals appear to be involved in dietary selection, and sugars and palatable substances affect neurochemical changes in the brain. For example, rats that drink sucrose solutions for 3 wk have major changes in neuronal activity in the limbic area of the brain, a region involved in pleasure and other emotions. We also investigate the relations between sucrose (and other sweet substances), drugs of abuse, and the mesolimbic dopaminergic system. The presence of sucrose in an animal's cage can affect the animals desire to self-administer drugs of abuse. Also, an animal's level of sucrose preference can predict its desire to self-administer cocaine. Such data suggest a relation between sweet taste and drug reward, although the relevance to humans is unclear. Finally, we address the influence of sugar on body weight control. For example, sucrose feeding for 2 wk decreases the efficiency of energy utilization and increases gene expression of uncoupling protein 3 in muscle, suggesting that sucrose may influence uncoupling protein 3 activity and contribute to changes in metabolic efficiency and thus regulation of body weight.