Lorenzo Polimeno

A Randomized Controlled Trial of Lactobacillus GG in Children With Functional Abdominal Pain

OBJECTIVE: Our aim was to determine whether Lactobacillus rhamnosus GG (LGG) relieves symptoms in children with recurrent abdominal pain. PATIENTS AND METHODS: A total of 141 children with irritable bowel syndrome (IBS) or functional pain were enrolled in 9 primary care sites and a referral center. Children entered a randomized, double-blind, placebo-controlled trial and received LGG or placebo for 8 weeks and entered follow-up for 8 weeks. The primary outcome was overall pain at the end of the intervention period. At entry and at the end of the trial, children underwent a double-sugar intestinal permeability test. RESULTS: Compared with baseline, LGG, but not placebo, caused a significant reduction of both frequency (P < .01) and severity (P < .01) of abdominal pain. These differences still were significant at the end of follow-up (P < .02 and P < .001, respectively). At week 12, treatment success was achieved in 48 children in the LGG group compared with 37 children in the placebo group (P < .03); this difference still was present at the end of follow-up (P < .03). At entry, 59% of the children had abnormal results from the intestinal permeability test; LGG, but not placebo, determined a significant decrease in the number of patients with abnormal results from the intestinal permeability testing (P < .03). These effects mainly were in children with IBS. CONCLUSIONS: LGG significantly reduces the frequency and severity of abdominal pain in children with IBS; this effect is sustained and may be secondary to improvement of the gut barrier.

Mammalian augmenter of liver regeneration protein is a sulfhydryl oxidase

BACKGROUND Augmenter of Liver Regeneration is an important secondary hepatic growth factor. Augmenter of liver regeneration protein has been shown to control mitochondrial gene expression and the lytic activity of liver-resident Natural Killer cells through the levels of interferon-gamma, but the precise enzymatic function of this protein is unknown. AIMS To define the enzymatic activity of augmenter of liver regeneration protein. The carboxy terminus of augmenter of liver regeneration protein contains a special CXXC motif characteristic for redox proteins and with faint homologies to the redox-active site of sulfhydryl oxidases. Tests were, therefore, carried out to establish whether isolated augmenter of liver regeneration protein can also function in the formation of sulfur bridges. METHODS Purified augmenter of liver regeneration proteins from rat and human were tested in enzyme assays for the ability to introduce disulfide bonds into protein substrates. The isolated proteins were tested for the formation of dimers and the presence of bound FAD was investigated spectroscopically. The function of the conserved CXXC motif was investigated by in vitro mutagenesis experiments and subsequent enzyme assays. RESULTS In this study, we demonstrate that rat and human augmenter of liver regeneration protein are flavin-linked sulfhydryl oxidases that catalyze the formation of disulfide bonds in reduced protein substrates. A flavin moiety is firmly but not covalently attached to the protein. In human cell cultures augmenter of liver regeneration protein is expressed in a long and short form that both exist as covalently linked dimers. The active site of the enzyme is associated with a conserved CXXC motif in the carboxy-terminal domain, that is present in the homologous proteins from yeast to humans and also in the human Q6 growth regulator protein. In vitro mutagenesis of one cysteine residue in the CXXC motif results in loss of enzymatic function and the mutated protein no longer binds FAD. CONCLUSIONS For the first time, these data assign an enzymatic activity to the important hepatic growth factor augmenter of liver regeneration protein. The finding that augmenter of liver regeneration protein acts as a FAD-linked sulfhydryl oxidase is essential to identify the molecular targets inside liver cells and to elucidate the precise role of mammalian augmenter of liver regeneration protein in hepatic cell growth, liver disease and regeneration.

Sex hormone-related functions in regenerating male rat liver

Sex hormone receptors were quantitated in normal male rat liver and in regenerating liver at several different times after partial (70%) hepatectomy. Both estrogen and androgen receptor content were altered dramatically by partial hepatectomy. Total hepatic content and nuclear retention of estrogen receptors increased, with the zenith evident 2 days after partial hepatectomy, corresponding to the zenith of mitotic index. Serum estradiol increased after 1 day, and reached a maximum at 3 days after surgery. In contrast, total and nuclear androgen receptor content demonstrated a massive decline at 1, 2, and 3 days after resection. Serum testosterone displayed a parallel decline. In addition, hepatic content of two androgen-responsive proteins was reduced to 15% and 13% of normal values during this period. The activity of these various proteins during regeneration of male rat liver is comparable to that observed in the liver of normal female rats. Taken together, these results indicate that partial hepatectomy induces a feminization of certain sexually dimorphic aspects of liver function in male rats. Furthermore, these data provide evidence that estrogens, but not androgens, may have an important role in the process of liver regeneration.

The augmenter of liver regeneration induces mitochondrial gene expression in rat liver and enhances oxidative phosphorylation capacity of liver mitochondria.

BACKGROUND The mammalian augmenter of liver regeneration gene encodes a protein involved in the unique process of liver regeneration. The augmenter of liver regeneration respective protein stimulates hepatocyte proliferation in hepatectomized rats and inhibits cytotoxic activity of liver-derived Natural Killer cells from intact rats. Augmenter of liver regeneration protein shares homology with a Saccharomyces Cerevisiae protein essential for the viability, oxidative phosphorylation and cell-division cycle. AIMS To demonstrate if augmenter of liver regeneration protein, like the homologous in the yeast, plays a role in the regulation of biogenesis of mitochondria. METHODS Augmenter of liver regeneration protein was injected in intact rats and, in the hepatic tissue, the expression of two genes located in two different regions of the mitochondrial genome, mitochondrial ATPase 6/8, and ND1 subunit, and of a nuclear gene, mitochondrial Transcription Factor A, were considered. In addition, cytochrome content and oxidative phosphorylation capacity of liver-derived mitochondria were evaluated. RESULTS The augmenter of liver regeneration protein administration induces an increase in the mitochondrial gene expression and enhances cytochrome content and oxidative phosphorylation capacity of liver-derived mitochondria. CONCLUSIONS The present data demonstrate a comparable role in the regulation of mitochondria biogenesis in the eukaryotic cell like the yeast protein. This phenomenon could be part of the complex mechanism through which augmenter of liver regeneration regulates hepatocyte proliferation.

Highly divergent amino termini of the homologous human ALR and yeast scERV1 gene products define species specific differences in cellular localization.

The yeast scERV1 gene product is involved in the biogenesis of mitochondria and is indispensable for viability and regulation of the cell cycle. Recently the general importance of this gene for the eukaryotic cell was shown by the identification of a structural and functional human homologue. The homologous mammalian ALR (Augmenter of Liver Regeneration) genes from man, mouse and rat are involved in the phenomenon of liver regeneration. A low expression rate of the genes is found in all investigated cells and mammalian tissues but it is specifically induced after damage of liver organs and is especially high during spermatogenesis. The alignment of the different proteins identifies a highly conserved carboxy terminus with more than 40% identical amino acids between yeast and mammals. The conserved carboxy terminus is functionally interchangeable between distantly related species like yeast and man. In contrast, the amino terminal parts of the proteins display a high degree of variability and significant differences even among closely related species. This finding leads to the problem whether the amino termini have comparable or divergent functions in different species. In this study we demonstrate by heterologous complementation experiments in yeast that the complete human ALR protein with its own amino terminus is not able to substitute for the yeast scERV1 protein. Fusion proteins of Alrp and scErv1p with the green fluorescence protein were created to investigate the respective subcellular localizations of these homologous proteins in yeast and human cells. In yeast cells human Alrp accumulates in the cytoplasm in contrast to yeast scErv1p that is preferentially associated with yeast mitochondria. Comparable studies with human cells clearly show that the homologous human Alrp is located in the cytosol of these cells. Fractionation experiments and antibody tests with yeast and human mitochondria and cellular extracts verify these findings.

Exhaled breath condensate pH measurement in children with asthma, allergic rhinitis and atopic dermatitis.

Recent studies have shown that the pH of exhaled breath condensate (EBC) could be predictive of asthma exacerbation. Moreover, it has been documented that both allergic rhinitis and atopic dermatitis constitute risk factors for the occurrence of asthma in a progression of disease known as atopic march. The aim of our study was to establish if condensate pH could be used as a valuable mean of monitoring of asthma in atopic children. We studied 34 atopic children with acute asthma, 70 with stable asthma, 35 children with allergic rhinitis, and 17 with atopic dermatitis. Thirty healthy children were used as controls. All children underwent skin prick tests and lung function tests. Exhaled breath condensate samples were collected with a condensing device and de‐aerated with argon. The pH of EBC was measured using a pH meter. Children with acute asthma were treated with inhaled steroids and bronchodilators. We found that the pH of condensate in patients with acute asthma was lower than that of patients with stable asthma, rhinitis, and controls (7.25 vs. 7.32, p < 0.05; 7.25 vs. 7.48, p < 0.02; 7.25 vs. 7.78, p < 0.0001, respectively). Patients with stable asthma, rhinitis, and eczema had also lower pH than that of controls (7.32, 7.48, and 7.44 vs. 7.78; p < 0.0001, p < 0.006, p < 0.04, respectively). Patients with acute asthma normalized their pH after treatment (7.82 vs. 7.25; p < 0.0001). Finally, patients with acute asthma showed a positive correlation between pH and lung functional parameters (forced expiratory volume in 1 s; r = 0.39, p = 0.04). Our study shows that EBC pH measurement may be a promising marker for assessing airway inflammation and monitoring response to anti‐inflammatory treatment in asthmatic children. Furthermore, we report the first evidence of airways acidification in children with allergic rhinitis and atopic dermatitis. Therefore, EBC pH assessment may be useful in the evaluation of progression of the atopic march toward the development of asthma later in life. Further studies are recommended in order to confirm this indication.

Proliferative activity of gastric epithelium in progressive stages of Helicobacter pylori infection

Helicobacter pylori (HP) infection is the main etiopathogenetic agent responsible for inflammatory and ulcerative changes in gastroduodenal mucosa and the basis for both intestinal and diffuse types of gastric carcinoma. In this latter case, intestinal metaplasia is the intermediary between gastritis and cancer. In this study we describe the proliferative activity of gastric epithelium in the progressive stages of HP infection. The expression of proliferating cell nuclear antigen (PCNA), which has proven to be a reliable method for this evaluation, was used as a marker. The study was performed on endoscopic biopsies of the gastric antrum of 40 patients, who were divided into five groups, eight in each group: normal histology and endoscopy, HP−; histological HP+ gastritis with normal endoscopy; histological HP+ gastritis with endoscopic evidence of chronic erosions; complete and incomplete intestinal metaplasia in a HP+ stomach. PCNA was detected by immunohistochemistry and expressed as labeling index, ie, percentage of positive nuclei either in the whole or upper third of foveolae. Our data show a progressive increase of epithelial proliferation in the successive stages of HP infection ranging from gastritis alone to the development of incomplete intestinal metaplasia, a well-known precancerous condition. The proliferative pattern tended to expand towards the upper foveolar third, which in normal conditions does not represent a site of epithelial renewal. These alterations may be related to the development of neoplastic transformations of gastric epithelium. It is well known that genetic mutations are facilitated in proliferating cells. Therefore, our results indicate that the high epithelial turnover, expressed by PCNA LI, may be an indicator of increased risk of neoplastic changes in long-standing untreated HP+ chronic gastritis.

Glucose metabolism during liver transplantation in dogs.

Arterial and hepatic venous blood levels of glucose were studied in 12 dogs during orthotopic liver transplantation performed under ketamine anesthesia without exogenous glucose administration. During the early part of surgery, arterial blood glucose levels were stable: 161 ± 12 mg/dl (mean ± SEM) after laparotomy and 183 ± 16mg/dl 5 min before the anhepatic stage. During the anhepatic stage, arterial blood glucose levels decreased progressively to 135 ± 9 and 88 ± 8 mg/dl, 5 min in the anhepatic stage and 5 min before reperfusion of the graft liver, respectively (P < 0.05). Reperfusion of the graft liver resulted in an increase in arterial glucose levels to 206 ± 17 and 240 ± 24 mg/dl, 5 and 30 min after reperfusion, respectively (P < 0.05). Hepatic venous blood glucose levels increased after reperfusion (405 ± 37 and 346 ± 41 mg/dl, 5 and 30 min after reperfusion, respectively) and were significantly higher than in arterial blood (P < 0.05). Arterial plasma insulin, measured in five animals, did not change significantly during the procedure, whereas plasma glucagon levels, stable during the preanhepatic and anhepatic stages, increased steadily after reperfusion of the graft liver, from 66.1 ± 14.2 to 108.4 ± 38.1 pg/ml (P < 0.05). This study shows that in dogs with ketamine anesthesia mild hypoglycemia occurs during the anhepatic stage of liver transplantation without exogenous glucose administration followed by hyperglycemia on reperfusion of the graft liver, possibly secondary to the release of glucose from the donor liver.

Lactobacillus reuteri strain combination in Helicobacter pylori infection: a randomized, double-blind, placebo-controlled study.

Goals: The goals of this study were to investigate the role of a new probiotic preparation (Lactobacillus reuteri DSM 17938 and L. reuteri ATCC PTA 6475) in Helicobacter pylori infection. Background: Specific probiotic strains play a role in H. pylori infection for their ability to decrease bacterial load and gastritis, prevent antibiotic-associated side effects, and increase the eradication rate. Study: This is a prospective, double-blind, randomized, placebo-controlled study in a tertiary care setting. A total of 100 H. pylori–positive naive patients received either L. reuteri combination (2×108 Colony Forming Units) or placebo during a 3-phase study (pre-eradication, eradication, and follow-up). All underwent 13C urea breath test (13C-UBT), blood assessments of gastrin-17 (G17), endoscopy, and the Gastrointestinal Symptom Rating Scale. Eradication was confirmed by 13C-UBT 8 weeks after the completion of therapy. Results: Fifty patients were allocated in each group. During pre-eradication period, 13C-UBT &dgr; decreased by 13% in L. reuteri combination as compared with a 4% increase in placebo (−13.2±34% vs. 4.3±27%; P<0.03). During eradication, GSRS increased significantly in placebo as compared with L. reuteri combination (6.8±2.9 vs. 4±3.1; P<0.01). Significantly less patients in L. reuteri combination as compared with placebo-reported side effects (40.9% vs. 62.8%; P<0.04). An abnormal G17 value was found in patients receiving placebo as compared with L. reuteri combination (28% vs. 12%; P<0.02). Eradication rate was 75% in L. reuteri combination and 65.9% in placebo (P=NS). L. reuteri combination increased eradication rate by 9.1% (odds ratio: 1.5). Conclusions: L. reuteri combination alone is able to exert an inhibitory effect on H. pylori growth, and when administered with eradication therapy, it determines a significant reduction in antibiotic-associated side effects. Moreover, L. reuteri combination was able to decrease serum G17 levels and to (not significantly) increase the H. pylori–eradication rate.

Different response to epidermal growth factor of hepatocytes in cultures isolated from male or female rat liver

Deoxyribonucleic acid (DNA) synthesis in hepatocytes isolated from the livers of male and female rats has been compared in monolayer culture. Plating efficiency, DNA and protein content, viability, and morphologic appearance were the same in cultures prepared with hepatocytes isolated from male or female rats. Epidermal growth factor (EGF)-induced DNA synthesis was significantly higher in hepatocytes from male rats than in hepatocytes from female rats. This was the case whether hepatocytes were isolated from normal or partially hepatectomized male or female rats. Hepatocytes isolated from regenerating liver synthesize more DNA than those isolated from normal liver in response to EGF. This increased response to EGF in hepatocytes derived from regenerating liver was relatively the same for male- and female-derived hepatocytes, but the magnitude of the response was considerably higher in male-derived hepatocytes. In contrast, in vivo DNA synthesis in the liver remnant after partial hepatectomy was similar in male and female rats if measured 24 h after the operation. A comparison of EGF binding to male- and female-derived hepatocytes maintained in primary culture indicated a lower number of high-affinity receptors for EGF in the female hepatocytes. The addition of estrogen to primary cultures of hepatocytes isolated from male rats inhibited EGF binding as well as EGF-induced DNA synthesis. Our studies show significant differences in DNA synthesis in response to EGF when male and female hepatocytes are compared in primary culture. The regenerative response after partial hepatectomy, on the other hand, was the same in male and female rats. Thus, our studies indicate that the sex of the donor, rat is important when hepatocytes in culture are used for a variety of studies, such as hepatocyte metabolism, induction and control of DNA synthesis, and hepatocarcinogenesis. In addition, our results indicate that caution is advised when inferences are made from in vitro findings for in vivo conditions.