An Integrated Comprehensive Peptidomics and In Silico Analysis of Bioactive Peptide-Rich Milk Fermented by Three Autochthonous Cocci Strains

Bioactive peptides (BPs) are molecules of paramount importance with great potential for the development of functional foods, nutraceuticals or therapeutics for the prevention or treatment of various diseases. A functional BP-rich dairy product was produced by lyophilisation of bovine milk fermented by the autochthonous strains Lactococcus lactis subsp. lactis ZGBP5-51, Enterococcus faecium ZGBP5-52 and Enterococcus faecalis ZGBP5-53 isolated from the same artisanal fresh cheese. The efficiency of the proteolytic system of the implemented strains in the production of BPs was confirmed by a combined high-throughput mass spectrometry (MS)-based peptidome profiling and an in silico approach. First, peptides released by microbial fermentation were identified via a non-targeted peptide analysis (NTA) comprising reversed-phase nano-liquid chromatography (RP nano-LC) coupled with matrix-assisted laser desorption/ionisation-time-of-flight/time-of-flight (MALDI-TOF/TOF) MS, and then quantified by targeted peptide analysis (TA) involving RP ultrahigh-performance LC (RP-UHPLC) coupled with triple-quadrupole MS (QQQ-MS). A combined database and literature search revealed that 10 of the 25 peptides identified in this work have bioactive properties described in the literature. Finally, by combining the output of MS-based peptidome profiling with in silico bioactivity prediction tools, three peptides (75QFLPYPYYAKPA86, 40VAPFPEVFGK49, 117ARHPHPHLSF126), whose bioactive properties have not been previously reported in the literature, were identified as potential BP candidates.

Evaluation of the Probiotic Properties of Lacticaseibacillus casei 431® Isolated from Food for Special Medical Purposes§

Research background

Increasing awareness of the importance of nutrition in health promotion and disease prevention has driven to the development of foods for special medical purposes (FSMPs). In this study, the probiotic strain Lacticaseibacillus paracasei ssp. paracasei (Lacticaseibacillus casei 431®) was incorporated into FSMPs to develop an innovative product. The aim was to investigate the influence of the FSMP matrix on the specific probiotic properties of L. casei 431® in vitro.

Experimental approach

A series of in vitro experiments were performed as part of the probiotic approach. After evaluation of antibiotic susceptibility profiles, functional properties such as survival under simulated gastrointestinal tract (GIT) conditions, bile salt deconjugation activities, cholesterol assimilation, antagonistic activity against spoilage bacteria and adhesion to Caco-2 cell line monolayers and extracellular matrix proteins were investigated.

Results and conclusions

The L. casei 431® strain, both the lyophilised strain and the strain isolated from the FSMP matrix, effectively survived the simulated adverse gastrointestinal conditions without significant effects of the food matrix. The effect of the FSMP matrix on the deconjugation activity of the bile salts of L. casei 431® was minimal; however, cholesterol assimilation was increased by 16.4 %. L. casei 431® had antibacterial activity against related lactic acid bacteria regardless of whether it was used in FSMPs or not. Conversely, the probiotic strain isolated from FSMP matrix had significantly higher inhibitory activity against six potential pathogens than the lyophilised culture. The autoaggregation ability of the L. casei 431® cells was not affected by the FSMP matrix. The adhesion of L. casei 431® bacterial cells to the extracellular matrix proteins was reduced after treatment with proteinase K, with the highest adhesion observed to laminin. The adhesion of L. casei 431® reduced the binding of E. coli 3014 by 1.81 log units and the binding of S. Typhimurium FP1 to Caco-2 cell lines by 1.85 log units, suggesting the potential for competitive exclusion of these pathogens.

Novelty and scientific contribution

The results support the positive effect of the FSMP matrix on the specific probiotic properties of L. casei 431®, such as antibacterial activity, bile salt deconjugation and cholesterol assimilation, while the incorporation of this probiotic strain adds functional value to the FSMPs. The synergistic effect achieved by the joint application of L. casei 431® and innovative FSMP matrix contributed to the development of the novel formulation of an improved functional food product with added value.

Modulation of the Gut Microbiota by the Plantaricin-Producing Lactiplantibacillus plantarum D13, Analysed in the DSS-Induced Colitis Mouse Model

Lactiplantibacillus plantarum D13 shows antistaphylococcal and antilisterial activity, probably due to the synthesis of a presumptive bacteriocin with antibiofilm capacity released in the cell-free supernatant (CFS), whose inhibitory effect is enhanced by cocultivation with susceptible strains. An in silico analysis of the genome of strain D13 confirmed the pln gene cluster. Genes associated with plantaricin biosynthesis, structure, transport, antimicrobial activity, and immunity of strain D13 were identified. Furthermore, the predicted homology-based 3D structures of the cyclic conformation of PlnE, PlnF, PlnJ, and PlnK revealed that PlnE and PlnK contain two helices, while PlnF and PlnJ contain one and two helices, respectively. The potential of the strain to modulate the intestinal microbiota in healthy or dextran sulphate sodium (DSS)-induced colitis mouse models was also investigated. Strain D13 decreased the disease activity index (DAI) and altered the gut microbiota of mice with DSS-induced colitis by increasing the ratio of beneficial microbial species (Allobaculum, Barnesiella) and decreasing those associated with inflammatory bowel disease (Candidatus Saccharimonas). This suggests that strain D13 helps to restore the gut microbiota after DSS-induced colitis, indicating its potential for further investigation as a probiotic strain for the prevention and treatment of colitis.

The Human Milk Microbiota Produces Potential Therapeutic Biomolecules and Shapes the Intestinal Microbiota of Infants

Human milk not only provides a perfect balance of nutrients to meet all the needs of the infant in the first months of life but also contains a variety of bacteria that play a key role in tailoring the neonatal faecal microbiome. Microbiome analysis of human milk and infant faeces from mother-breastfed infant pairs was performed by sequencing the V1-V3 region of the 16S rRNA gene using the Illumina MiSeq platform. According to the results, there is a connection in the composition of the microbiome in each mother-breastfed infant pair, supporting the hypothesis that the infant's gut is colonised with bacteria from human milk. MiSeq sequencing also revealed high biodiversity of the human milk microbiome and the infant faecal microbiome, whose composition changes during lactation and infant development, respectively. A total of 28 genetically distinct strains were selected by hierarchical cluster analysis of RAPD-PCR (Random Amplified Polymorphic DNA-Polymerase Chain Reaction) electrophoresis profiles of 100 strains isolated from human milk and identified by 16S RNA sequencing. Since certain cellular molecules may support their use as probiotics, the next focus was to detect (S)-layer proteins, bacteriocins and exopolysaccharides (EPSs) that have potential as therapeutic biomolecules. SDS-PAGE (Sodium Dodecyl-Sulfate Polyacrylamide Gel Electrophoresis) coupled with LC-MS (liquid chromatography-mass spectrometry) analysis revealed that four Levilactobacillus brevis strains expressed S-layer proteins, which were identified for the first time in strains isolated from human milk. The potential biosynthesis of plantaricin was detected in six Lactiplantibacillus plantarum strains by PCR analysis and in vitro antibacterial studies. ¹H NMR (Proton Nuclear Magnetic Resonance) analysis confirmed EPS production in only one strain, Limosilactobacillus fermentum MC1. The overall microbiome analysis suggests that human milk contributes to the establishment of the intestinal microbiota of infants. In addition, it is a promising source of novel Lactobacillus strains expressing specific functional biomolecules.

A Lactic Acid Bacteria Consortium Impacted the Content of Casein-Derived Biopeptides in Dried Fresh Cheese

This study aimed to define a consortium of lactic acid bacteria (LAB) that will bring added value to dried fresh cheese through specific probiotic properties and the synthesis of bioactive peptides (biopeptides). The designed LAB consortium consisted of three Lactobacillus strains: S-layer carrying Levilactobacillus brevis D6, exopolysaccharides producing Limosilactobacillus fermentum D12 and plantaricin expressing Lactiplantibacillus plantarum D13, and one Enterococcus strain, Enterococcus faecium ZGZA7-10. Chosen autochthonous LAB strains exhibited efficient adherence to the Caco-2 cell line and impacted faecal microbiota biodiversity. The cheese produced by the LAB consortium showed better physicochemical, textural and sensory properties than the cheese produced by a commercial starter culture. Liquid chromatography coupled with matrix-assisted laser desorption/ionization-time of flight tandem mass spectrometry (LC-MALDI-TOF/TOF) showed the presence of 18 specific biopeptides in dried fresh cheeses. Their identification and relative quantification was confirmed by liquid chromatography-tandem mass spectrometry (LC-MS/MS) using multiple reaction monitoring (MRM). The results also showed that their synthesis resulted mainly from β-casein and also α-S1 casein degradation by proteolytic activities of the LAB consortium. The designed LAB consortium enhanced the functional value of the final product through impact on biopeptide concentrations and specific probiotic properties.

Lyophilized alginate-based microspheres containing Lactobacillus fermentum D12, an exopolysaccharides producer, contribute to the strain's functionality in vitro

Lactobacillus (Limosilactobacillus) fermentum D12 is an exopolysaccharide (EPS) producing strain whose genome contains a putative eps operon. Whole-genome analysis of D12 was performed to disclose the essential genes correlated with activation of precursor molecules, elongation and export of the polysaccharide chain, and regulation of EPS synthesis. These included the genes required for EPS biosynthesis such as epsA, B, C, D and E, also gt, wzx, and wzy and those involved in the activation of the precursor molecules galE, galT and galU. Both the biosynthesis and export mechanism of EPS were proposed based on functional annotation. When grown on MRS broth with an additional 2% w/v glucose, L. fermentum D12 secreted up to 200 mg/L of a mixture of EPSs, whose porous structure was visualized by scanning electron microscopy (SEM). Structural information obtained by ¹HNMR spectroscopy together with composition and linkage analyses, suggested the presence of at least two different EPSs, a branched heteropolysaccharide containing t-Glcp and 2,6-linked Galf, and glycogen. Since recent reports showed that polysaccharides facilitate the probiotic-host interactions, we at first sought to evaluate the functional potential of L. fermentum D12. Strain D12 survived simulated gastrointestinal tract (GIT) conditions, exhibited antibacterial activity against enteropathogenic bacteria, adhered to Caco-2 cells in vitro, and as such showed potential for in vivo functionality. The EPS crude extract positively influenced D12 strain capacity to survive during freeze-drying and to adhere to extracellular matrix (ECM) proteins but did not interfere Caco-2 and mucin adherence when added at concentrations of 0.2, 0.5, and 1.0 mg/mL. Since the viable bacterial count of free D12 cells was 3 logarithmic units lower after the exposure to simulated GIT conditions than the initial count, the bacterial cells had been loaded into alginate for viability improvement. Microspheres of D12 cells, which were previously analyzed at SEM, significantly influenced their survival during freeze-drying and in simulated GIT conditions. Furthermore, the addition of the prebiotic substrates mannitol and lactulose improved the viability of L. fermentum D12 in freeze-dried alginate microspheres during 1-year storage at 4 °C compared to the control.

The functional capacity of plantaricin-producing Lactobacillus plantarum SF9C and S-layer-carrying Lactobacillus brevis SF9B to withstand gastrointestinal transit

Background

We evaluated the functional capacity of plantaricin-producing Lactobacillus plantarum SF9C and S-layer-carrying Lactobacillus brevis SF9B to withstand gastrointestinal transit and to compete among the gut microbiota in vivo. Considering the probiotic potential of Lb. brevis SF9B, this study aims to investigate the antibacterial activity of Lb. plantarum SF9C and their potential for in vivo colonisation in rats, which could be the basis for the investigation of their synergistic functionality.

Results

A plantaricin-encoding cluster was identified in Lb. plantarum SF9C, a strain which efficiently inhibited the growth of Listeria monocytogenes ATCC^® 19111™ and Staphylococcus aureus 3048. Homology-based three-dimensional (3D) structures of SF9C plantaricins PlnJK and PlnEF were predicted using SWISS-MODEL workspace and the helical wheel representations of the plantaricin peptide helices were generated by HELIQUEST. Contrary to the plantaricin-producing SF9C strain, the S-layer-carrying SF9B strain excluded Escherichia coli 3014 and Salmonella enterica serovar Typhimurium FP1 from the adhesion to Caco-2 cells. Finally, PCR-DGGE analysis of the V2–V3 regions of the 16S rRNA gene confirmed the transit of the two selected lactobacilli through the gastrointestinal tract (GIT). Microbiome profiling via the Illumina MiSeq platform revealed the prevalence of Lactobacillus spp. in the gut microbiota of the Lactobacillus-treated rats, even on the 10th day after the Lactobacillus application, compared to the microbiota of the healthy and AlCl₃-exposed rats before Lactobacillus treatment.

Conclusion

The combined application of Lb. plantarum SF9C and Lb. brevis SF9B was able to influence the intestinal microbiota composition in rats, which was reflected in the increased abundance of Lactobacillus genus, but also in the altered abundances of other bacterial genera, either in the model of healthy or aberrant gut microbiota of rats. The antibacterial activity and capacity to withstand in GIT conditions contributed to the functional aspects of SF9C and SF9B strains that could be incorporated in the probiotic-containing functional foods with a possibility to positively modulate the gut microbiota composition.

Influence of Dehydrated Wheat/Rice Cereal Matrices on Probiotic Activity of Bifidobacterium animalis ssp. lactis BB-12®§

Three novel dehydrated wheat/rice cereal functional products with an addition of well documented probiotic Bifidobacterium animalis ssp. lactis BB-12® (BB-12®) were developed in Podravka factory for the infants older than 4 months: instant rice cereal, instant rice cereal with fruits and instant wheat cereal with vanilla. Notably, the number of viable BB-12® cells in each of the novel products was higher than the required minimal number of probiotic cells per gram of product (10⁶ CFU/g) during the storage period of 106 weeks. Therefore, BB-12® strain recovery and genome stability were evaluated by strain-specific polimerase chain reaction and amplified fragment length polymorphism fingerprinting analysis. Further aim was to evaluate the influence of these three different cereal food matrices on specific probiotic properties of BB-12® strain in vitro. Applied food matrices positively influenced the survival in the simulated conditions of the gastrointestinal tract and antagonistic activity against undesirable microorganisms, while no influence on auto- and coaggregation ability of B. animalis ssp. lactis BB-12® was observed. Adhesion to extracellular matrix proteins and intestinal epithelial Caco-2 cells together with antibacterial activity emphasized competitive pathogen exclusion from Caco-2 cells by probiotic strain BB-12®.

Historical impact to drive research in peptic ulcer disease

The story of gastric acid secretion began with early ideas on gastric secretion (Spallanzani and de Réaumur, 17th century) and with first descriptions of food digestion (Dupuytren and Bichat, Beaumont, early 18th century), followed by proof that gastric juice contained acid (Prout, early 18th century). The research continued with first descriptions of gastric glands as the source of gastric acid and its changes upon digestive stimulus (Purkinje and Golgi, mid and late 19th century). The theory of 'nervism' - the neuro-reflex stimulation of gastric secretion by vagal nerve (Pavlov, early 20th century) was contrasted by a histamine-mediated concept of gastric secretion (Popielski and Code, mid 20th century). Thus, gastric acid and pepsin (Schwann, early 19th century) were found to be essential for food digestion and studies also pointed to histamine, being the most potent final common chemostimulator of oxyntic cells. The discoveries in etiopathogenesis of mucosal injury were marked by the famous dictum: 'No acid, no ulcer' ('Ohne saueren Magensaft kein peptisches Geschwür', Schwarz, 1910) that later induced the term of 'mucosal defense' and the notion that the breaking of 'gastric mucosal barrier' represents the initial step in the process of mucosal injury (Davenport, Code and Scholer, mid 20th century). The prostaglandins were shown to influence all major components of gastric mucosal barrier, described with the term 'cytoprotection' (Vane, Robert and Jacobson, 1970s). Beginning in the latter half of 19th century, the studies on gastric bacteriology that followed enabled the discovery of association between Campylobacter (Helicobacter) pylori and peptic ulcers (Warren and Marshall, 1980s) that led to worldwide major interventions in treating peptic ulcer disease. The surgical approach to peptic ulcer had been outlined by resection procedures (Billroth, Pean, Moynihan, late 19 century) and vagotomy, with or without drainage procedures (Jaboulay, Latarjet, Dragstedt, mid 20th century). Antacids, protective agents, anticholinergics, and later gastrin antagonists and prostaglandins were used for decades in the treatment of peptic ulcer, with differing effects. The advent of the concept of H(2)-receptor antagonists (Black, 1970s) and the discovery of acid (proton) pumps in parietal cells (Ganser, Forte and Sachs, late 1970s) paved the way for potent (H(2) antagonists) and profound acid inhibition (proton pump inhibitors) that revolutionized the treatment of acid-related disorders, including peptic ulcer disease. Worldwide, peptic ulcer and its complications remain the cause of significant morbidity, especially in older age groups, representing a major burden for ambulatory and hospital healthcare resources.

Peptic ulcer disease in dyspeptic patients with ischemic heart disease: search and treat?

OBJECTIVE

The aim of this study was to determine the prevalence and risk factors for peptic ulcer disease (PUD) in dyspeptic patients with ischemic heart disease (IHD), and to assess whether the healing of PUD before coronary artery bypass grafting (CABG) could reduce the need for urgent postoperative endoscopy.

PATIENTS AND METHODS

A series of 894 patients referred to Dubrava University Hospital in Zagreb for elective CABG during the period from May 1998 until April 2001 was prospectively analysed. Dyspepsia was assessed by a questionnaire, PUD by upper gastrointestinal endoscopy, and H. pylori status by histology/Giemsa staining and the rapid urease test. The need for urgent postoperative endoscopy (hematemesis and/or melena, sudden onset of anemia or unexplained epigastric pain) was compared between the prospective study group of 894 patients and a series of 463 patients referred for CABG to Dubrava University Hospital during the period from January 1997 until April 1998.

RESULTS

Gastroduodenal dyspepsia predominated in 184 (20.6 %) patients, 142 (77.2 %) of them with Helicobacter (H.) pylori infection and 69 (37.5 %) with verified PUD. Univariate analysis indicated the increased risk of multiple PUD to be related to a previous diagnosis of PUD (OR 3.61, 95 % CI 1.32 - 9.82), H. pylori infection (OR 18.86, 95 % CI 2.31 - 153.98), use of aspirin (OR 5.70; 95 % CI 1.80 - 18.03) and left coronary artery occlusions (3.10, 95 % CI 1.00 - 9.59). Multivariate analysis pointed to H. pylori infection (OR 16.30, 95 % CI 1.57 - 168.53) and left coronary artery occlusions (OR 4.84, 95 % CI 1.05 - 22.30) as independent risk factors for multiple PUD. The OR for urgent postoperative endoscopy due to a major gastrointestinal event was 9.9 (95 % CI 2.2 - 45.1) and the OR for active peptic ulcer with stigmata of recent bleeding was 6.9 (95 % CI 1.4 - 33.1) in the group of patients with IHD who were not submitted to evaluation for dyspepsia prior to elective heart surgery.

CONCLUSIONS

In areas with a high prevalence of H. pylori infection, endoscopy and a "search and treat" strategy for IHD patients with dyspepsia before elective cardiac surgery should significantly reduce the need for urgent postoperative endoscopy due to major gastrointestinal events.

Helicobacter pylori infection in patients with Brunner's gland adenoma

Histopathologic and clinical data strongly suggest a causal relation between Helicobacter pylori infection and gastritis, peptic ulcer disease, or both. However, little has been written about the potential association between H. pylori infection and Brunner's gland adenoma. Therefore, we carried out a prospective study to determine the presence of H. pylori infection among patients with Brunner's gland adenoma. From November 1996 till October 1999, 19100 patients who had undergone upper gastrointestinal endoscopy at two clinical centers in Zagreb, Croatia, were candidates for participation in the study. Brunner's gland adenoma was diagnosed on the basis of histologic samples taken from the polyp (four patients) or after the entire polyp was made available upon endoscopic removal (three patients). When all endoscopic examinations had been performed, biopsy samples were taken from the antrum and body of the stomach, so that gastritis could be classified and H. pylori determined by histology. Biopsy samples were also taken from the duodenal bulb to verify duodenitis. Two other samples were taken from the antrum for rapid urease test. The patients were considered positive for H. pylori when both histology and rapid urease test were positive. Brunner's gland adenoma was diagnosed in seven patients (five women and two men; median age, 49 yrs). Five (71%) patients with diagnosed Brunner's gland adenoma had concurrent H. pylori infection. Duodenitis associated with gastric metaplasia was observed in six patients. Complete eradication of H. pylori was achieved in only two patients. Symptoms disappeared or markedly diminished in all patients with significant improvement during therapy or immediately upon endoscopic removal of the polyp. Although limited by a very small number of patients, our results suggest that concurrent H. pylori infection is very common in patients with Brunner's gland adenoma. However, the role of H. pylori infection in the pathogenesis and development of Brunner's gland hyperplasia remains unclear.

Duplex ultrasonography in diagnosis of spigelian hernia with incarcerated jejunal loop

Spigelian hernia is a very rare anterior abdominal wall hernia with uncharacteristic symptoms and challenging diagnosis. The case of a 76-year-old male patient with colicky pain and vomiting lasting for 24 hours before admission to the hospital is presented. Physical examination of the patient revealed abdominal tenderness and a round-shaped tumefaction of 3 cm in size, located in the left lower abdominal quadrant. X-ray examination of the abdomen, obtained in left lateral position of the patient, showed small bowel ileus with distended jejunal loops. The abdominal ultrasound examination, followed by duplex ultrasonography, revealed a spigelian hernia with ischemic changes of strangulated bowel segment indicating incarceration of the herniated jejunal loop. Preoperative findings were confirmed by intraoperative diagnosis of spigelian hernia and incarcerated jejunal loop with ischemic changes and deserosation, followed by resection of the bowel segment involved and plastic surgical reconstruction of anterior abdominal wall. This case report highlights the role of duplex ultrasonography in the evaluation of circulatory status of potentially incarcerated bowel segment within hernial sac.

Benign epithelial gastric polyps--frequency, location, and age and sex distribution

Prospective investigation has been undertaken with the aim to study the frequency, location and age and sex distribution of various histological types of benign gastric epithelial polyps. Histological type--adenomatous, hyperplastic and fundic gland polyps--was diagnosed on the basis of at least three histological samples taken from the polyp. Biopsy samples were also taken from the antrum and the body of the stomach so that gastritis could be graded and classified, and the presence of H. pylori could be determined by histology. All 6,700 patients, who had undergone upper gastrointestinal endoscopy in a one-year period, participated in this study. Among them 42 benign gastric epithelial polyp were found in 31 patients: adenomatous gastric polyps in 7 patients, hyperplastic gastric polyp in 21 and fundic gland polyp in 3 patients. All patients with hyperplastic polyps had chronic active superficial gastritis, whereas most of the patients with adenomatous polyps had a chronic atrophic gastritis with high prevalence of intestinal metaplasia. Among 21 patients with hyperplastic gastric polyps, 16 (76%) patients were positive for H. pylori infection in contrast to only 2 patients (29%) with adenomatous gastric polyps and 1 patient (33%) with fundic gland polyp. Presented data indicates that hyperplastic gastric polyps are the most common and they are associated with the presence of chronic active superficial gastritis and concomitant H. pylori infection. Adenomatous polyps are rarer and they tend to be associated with chronic atrophic gastritis and intestinal metaplasia. Fundic gland polyp is the rarest type of gastric polyps.

Effects of dopaminergic drugs on inflammatory bowel disease induced with 2,4-dinitrofluorbenzene in BALB/c mice

The aim of the study was to demonstrate the effects of dopaminergic drugs on 2,4-dinitrofluorbenzene (DNFB) induced experimental inflammatory bowel disease (IBD) in previously sensitized BALB/c mice. The number and extent of ulcerations and erosions, the intensity of haemorrhages, oedema, and accumulation of neutrophils and eosinophils within colonic lamina propria and submucosa were scored and statistically evaluated. The 180 BALB/c mice, were allocated into three equal groups. The mice in the first experimental group were treated with domperidone (DP), a peripheral dopamine (DA) antagonist. The mice from the second experimental group were treated with bromocriptine (BC), a dopamine agonist. The mice from the control group were treated with an equivalent volume of normal saline in the same manner. Ten animals from each group were killed on days 1, 2, 3, 5 and 10, subsequent to the challenge enema of DNFB solution. Gross and microscopic examination of the colon was performed. Treatment with BC resulted in clinical improvement and decreased mortality rate by 2 of 60 (3%), while domperidone treatment increased mortality rate to 12 of 60 (20%) compared with the controls [4 of 60 (6%)]. The analysis of the microscopic lesions indicated that the beneficial effects of BC were the result of maintenance of vascular integrity.

[Weather, climate and health]

The notion of complex influence of atmospheric conditions on modem human population, especially the relationship between weather, climate and human healths, has actuated the World Meteorological Organisation to commemorate the coming into force, on March 23, 1950, of the Convention of WMO and this year to celebrate this day by focusing on theme of current interest--"Weather, climate and health". In the light of this, the authors of this paper reveal the results of recent studies dealing with influence of sudden and short-term changes in weather and climate on human health, and future expected climate changes due to "greenhouse" effect, increase in global temperature and tropospheric ozone depletion, as well. Special attention is given to climate shifts due to ENSO (El Niño/Southern Oscillation) phenomenon because of its great impact on human society and epidemics of certain infectious diseases. The results of biometeorological studies dealing with complex influence of daily weather changes on incidence of certain diseases in Croatia have also been presented. In addition, the authors have stated their own view and opinion in regard to future biometeorlogical studies in Croatia in order to achieve better understanding of influence of climate and weather changes on human health, and help prevention of mortality and morbidity related to chronic noninfectious diseases.

The effect of eradicating Helicobacter pylori infection on the course of adenomatous and hyperplastic gastric polyps

OBJECTIVE

Histopathological and clinical data strongly suggest that Helicobacter pylori is the cause of chronic gastritis and peptic ulceration. However, little has been written about the potential causal relation of H. pylori infection to hyperplastic and adenomatous gastric polyps. We therefore carried out a prospective study to determine the effect of eradicating H. pylori infection on the course of hyperplastic and adenomatous gastric polyps.

METHODS

From November 1996 to December 1997, 6700 patients who had undergone upper gastrointestinal endoscopy at the two centres in Zagreb, Croatia, were candidates for participation in the study. Hyperplastic and adenomatous polyps were diagnosed on a basis of at least three histological samples taken from the polyp. In seven patients endoscopy had to be repeated because forceps biopsy sampling either provided inadequate tissue for correct histological diagnosis, or accurate characterization of gastric polyp histology was not possible. Upon completion of all endoscopic examinations before and after treatment, biopsy samples were taken from the antrum (two) and the body of the stomach (two) so that gastritis could be graded and classified, and the presence of H. pylori sought by histology. Two other samples were taken from the antrum for a rapid urease test. Follow-up examinations were performed by using endoscopy. Control endoscopy was performed at least 4 weeks after the treatment of H. pylori infection had been completed, and then every 3-4 months. The follow-up ranged from 4 to 17 months, with a median of 14 months. The treatment of H. pylori infection consisted of a 1-week course of either omeprazole (20 mg twice daily) or pantoprazole 40 mg twice daily), and a 1-week course of amoxicillin 2g twice daily) and metronidazole (400 mg three times daily), and clarithromycin (500 mg twice daily). Eradication of H. pylori infection was assessed by repeated histology and rapid urease test.

RESULTS

Twenty-one patients (nine women, 12 men; median age 52 years) with histologically proven hyperplastic gastric polyps, and seven patients (two women, five men; median age, 67 years) with adenomatous gastric polyps were included in the study. Among 21 patients with hyperplastic gastric polyps, 16 patients (76%) were positive for H. pylori infection. Only two patients (29%) with adenomatous gastric polyps were positive for the infection. Complete eradication of H. pylori was initially achieved in all patients positive for H. pylori. Total regression of the gastric polyps was observed only among the patients with hyperplastic gastric polyps in whom H. pylori had been eradicated. Complete regression of the hyperplastic gastric polyps was observed in seven of the 16 evaluable patients (44%; 95% CI, 19-68%) after H. pylori eradication. The endoscopic snare polypectomy was carried out in nine patients with hyperplastic polyps and two patients with adenomatous gastric polyps in whom regression of the polyps was not observed after H. pylori eradication, as well as in five patients with hyperplastic and four with adenomatous gastric polyps who were negative for H. pylori. Exploratory laparotomy and gastrotomy with polyps excision were carried out in one patient with multiple adenomatous gastric polyps. In only one patient who was not positive for H. pylori recurrence of hyperplastic gastric polyp was recorded during follow-up, and no re-infection with H. pylori has been detected.

CONCLUSIONS

Our results suggest that the development of hyperplastic gastric polyps may be directly related to chronic active gastritis and concomitant H. pylori infection. Cure of H. pylori infection associated with hyperplastic gastric polyps resulted in complete polyp regression in more than 40% of patients. Therefore, for patients with hyperplastic gastric polyps and concurrent H. pylori infection an antibiotic treatment designed to eradicate H. pylori appears to be recommended before further therapeutic options are consi

Predictive factors influencing the therapeutic response to diuretic treatment of ascites in nonazotemic cirrhotic patients

BACKGROUND

A low-sodium diet and diuretics, although widely used, are not always the most satisfactory therapy for treatment of ascites in nonazotemic patients with liver cirrhosis. The objective of this investigation was to analyze various predictive factors influencing the therapeutic response to diuretic treatment of ascites in these patients.

METHODS

Twenty-seven patients with nonazotemic liver cirrhosis and ascites were initially treated with spironolactone, 200 mg/day. If no response was observed, furosemide was added at 40-120 mg/day. Before and during the diuretic therapy 30 clinical and laboratory variables were investigated as possible predictive factors influencing the therapeutic response to diuretics. The renal arterial resistive index (RI) (reflecting renal vascular resistance) was estimated with duplex Doppler ultrasonography.

RESULTS

Sixteen of the 27 patients (59%) responded to spironolactone alone, whereas 6 patients (22%) responded to combined diuretic therapy with spironolactone and furosemide. Five patients (19%) did not respond to diuretic treatment. Eight of the 30 variables analyzed were statistically significant as possible predictive factors influencing the diuretic response: previous episodes of ascites and gastrointestinal hemorrhage, the presence of peripheral edema, the amount of ascites, plasma renin activity, plasma aldosterone concentrations, urinary sodium excretion, and renal interlobar arterial RI. In all patients who had diuretic-resistant ascites, renal interlobar arterial RI was greater than 0.70. Only 9% of patients who responded satisfactorily to diuretic therapy had interlobar arterial RI greater than 0.70.

CONCLUSIONS

According to our results, consideration for combining the clinical findings with noninvasively measured renal arterial RI using duplex Doppler ultrasonography would be mandatory in identifying a subgroup of cirrhotic patients with ascites who are at high risk for diuretic unresponsiveness.

Animal models of inflammatory bowel disease

The aim of this article was to reveal the major biologic features of intestine that predispose the intestinal mucosa to numerous inflammatory conditions, especially in regard to experimental models of inflammatory bowel disease. The need for the greater understanding of the etiology of intestinal inflammation and the search for more effective and novel therapy for the treatment of the disease has led to the development of variety of experimental models of inflammatory bowel disease. There is a growing number of animal models of inflammatory bowel disease, either naturally occurring in several mammalian species or inducible in various species of experimental animals by using physical, chemical and biologic agents including the embryonic stem cell technology for specific gene targeted defects. Despite some serious objectives in regard to clinical aspects of human intestinal bowel disease, animal models of intestinal inflammation have advantages and being complementary to clinical approach indicate the clear need for experimental studies to be continued.

Histopathologic features of T-cell mediated colonic injury induced with 2,4-dinitrofluorobenzene in BALB/c mice

The aim of the study was to reveal the histopathologic features of intestinal inflammation as demonstrated in BALB/c mice, using the challenge of 2,4-dinitrofluorobenzene (DNFB) with or without previous sensitization. Forty mice were randomized into 5 groups. Two groups of animals were treated with rectal enema of 0.2% or 1.0% of 2,4-dinitrofluorobenzene solution. Third group was pretreated with 2 sensitizing doses of DNFB. Two control groups were treated with PBS or acetone and vehicle enema only (acetone and olive oil). In order to assess the extent of colonic inflammation and damage, a histopathologic score scale was developed. In contrast to scanty superficial ulcerations and mild edema observed in the control group of animals, edema, ulcerations, hemorrhage, necrosis and infiltration of inflammatory cells were observed in experiment groups treated with enema of DNFB. Total score of lesion as well almost all inflammatory parameters of injury observed were highest in previously sensitized animals. The results of this study clearly demonstrated the pattern of colonic inflammation induced with DNFB using the histopathologic scoring scale system.

[Distribution of hand laterality in preschool-age children]

Laterality means functional dominance of one in the pair of organs. It represents the external manifestation of integrative activity of cerebral cortex meaning the domination of functionally dominant hand; the usability lateralization depends on the domination of cerebral hemisphere of gestural lateralization and the domination of cerebral hemisphere or gestural lateralization and the influence of the environment. On the basis of laterality population is divided into right-handed and left-handed with a very stressed degree of lateralization and those undecided with a minimal previal of handidness of one hand. In most people the domination of cerebral hemisphere is average or weak and that's the reason why the influence of the environment is of importance when forming the dominant hand. In the clinical practice the hand laterality is used as an index for the type and degree of cerebral hemisphere domination, for condition of gestural laterality with the usability of the dominant hand and form the differentiation of the dominant hand in the case of minimal difference in handidness.

Effect of methylprednisolone on small bowel, spleen and liver changes in a murine model of inflammatory bowel disease

The aim of this study was to evaluate the influence of methylprednisolone (1 mg/kg, i.p.) on inflammatory lesions in the small bowel, liver (pericholangitis) and spleen (lymphofollicular proliferation), in a model of inflammatory bowel disease induced by 2.4-dinitrofluorobenzene in previously sensitized BALB-c mice. As a parameter of corticosteroid anti-inflammatory and immunosuppressive action, we simultaneously investigated its effects on mononuclear cell accumulation within the ileal lamina propria and submucosa during the observed time period (1-30 days). We noted a significant decrease in accumulation of mononuclear cells within the lamina propria (P < 0.001). An effect on mononuclear cell infiltration within the ileal submucosa was also noted but was not statistically significant. In addition, pericholangitis in the liver and lymphofollicular proliferation in the spleen were not observed in the experimental group during treatment with methylprednisolone. The results of this study indicate that the previously described model of intestinal inflammation could be used in further research of present and new therapeutic modalities for inflammatory bowel disease.

Inhibition and stimulation of prolactin release. Delayed response in duodenal ulcer patients

Prolactin inhibitory tests (bromocriptine in a single dose 2.5 mg orally) as well as stimulatory tests (metoclopramide in a single dose of 10 mg intravenously) were performed in 33 patients with endoscopically proven duodenal ulcer and in 32 healthy volunteers. Delayed response in inhibition of prolactin release as well as in stimulation of prolactin release was observed in duodenal ulcer patients compared to healthy volunteers (P < 0.01). The results implicate the role of the dopamine-prolactin axis in the pathogenesis of duodenal ulcer disease.

[The significance of low levels of total proteins, albumins, globulins and complement factors in ascitic fluid and the development of spontaneous bacterial peritonitis in patients with liver cirrhosis]

Spontaneous bacterial peritonitis is one of the most common complications of ascitic fluid in patients with liver cirrhosis. The aim of this study was to investigate the role of total protein, albumin, globulin and complement ascitic fluid concentrations in development of spontaneous bacterial peritonitis in patients with liver cirrhosis. In patients with liver cirrhosis and spontaneous bacterial peritonitis (n = 8) the ascitic fluid total protein, albumin and globulin concentrations were significantly lower than in patients with sterile ascites (n = 11) (p < 0.01). The ascitic fluid complement C3 and C4 concentrations were significantly lower in patients with spontaneous bacterial peritonitis than in patients with sterile ascites (9.1 +/- 3.1 mg/dL to 22.9 +/- 17.4 mg/dL, p < 0.01; 3.8 +/- 5.9 mg/dL to 8.2 +/- 5.9 mg/dL, p < 0.01, respectively). The ascites total protein, albumin, globulin and complement concentrations in cirrhotic patients with spontaneous bacterial peritonitis were significantly lower than in patients with sterile ascites demonstrating the importance of those factors in ascitic fluid defense against secondary bacterial infection.

Assessment of value of pancreatic pseudocyst amylase concentration in the treatment of pancreatic pseudocysts by percutaneous evacuation

The aim of our study was to determine the value of the percutaneous pancreatic pseudocyst evacuation. We assessed the relation between the amylase concentration of the pseudocyst contents and the final outcome of the disease treated by the percutaneous evacuation. Forty-three patients with a history of acute pancreatitis and pancreatic pseudocysts larger than 5 cm in diameter that persisted beyond 6 weeks were divided into four groups relative to the amylase concentration in the pseudocystic contents and the number of evacuations. The results show a good correlation between low amylase concentration in the liquid pseudocystic contents (less than or equal to 64 WU) and the healing rate after the percutaneous evacuation (p less than 0.001). The percutaneous evacuation of the pseudocysts failed in patients with increased amylase concentrations in the pseudocyst fluid regardless of the number of evacuations. We conclude that surgical treatment is indicated in patients who have amylase-rich pseudocyst contents.

A model of inflammatory bowel disease induced by 2,4-dinitrofluorobenzene in previously sensitized BALB-c mice

The aim of this study was to develop a model of inflammatory bowel disease (IBD) induced by colonic application of 2,4-dinitrofluorobenzene in previously sensitized BALB-c mice. During the follow-up period of 30 days we observed ulcerations, haemorrhage, necrosis, and mononuclear infiltration in the colonic mucosa of previously sensitized (experimental) and, to a lesser extent, nonsensitized (control) animals. In addition, the animals in the experimental group developed adhesions, thickening of colonic segments, stenosis, and dilatation of the colon, and some animals also developed megacolon. Oedema, mononuclear infiltration, and superficial ulcerations were observed in the ileum of experimental animals and, to a lesser extent, in the control group. In addition, the animals in the experimental group developed extraintestinal changes in the liver and spleen (that is, pericholangitis and lymphofollicular proliferation). We suggest that this model of IBD may have some value for the study of early pathogenetic mechanisms of IBD and for developing new therapeutic modalities for this condition.

The value of pancreatic pseudocyst amylase concentration in the detection of pseudocyst communication with the pancreatic duct

The aims of the study were to compare the results of endoscopic retrograde cholangiopancreatography (ERCP) and percutaneous cystopancreatography (PCP) in the detection of the communication between the pancreatic pseudocyst and the pancreatic duct, and to assess the reliability of the increased amylase concentration in the pseudocyst content as an indicator of the existence of communication between the pancreatic pseudocyst and the pancreatic duct system. Forty-three patients were included in the study. Pseudocystic fluid content was obtained by percutaneous aspiration. Twenty-four patients had pseudocyst amylase concentrations above 64 Wolgemuth units (WU), and 19 patients had less than 64 WU. The communication between pseudocyst and the pancreatic duct was determined in 22 patients by ERCP and in 13 patients by PCP, all in the group with increased pseudocyst amylase concentration. Due to high sensitivity and specificity of pseudocyst amylase concentration for the existence of pseudocyst communication with the pancreatic duct, we conclude that guided percutaneous aspiration of the pancreatic pseudocyst with the determination of amylase concentration in the fluid can replace ERCP as a method of choice for the detection of pseudocyst communication with the pancreatic duct.