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At least 415 records · Page 23Linked to original sources
PubMed2003

Morphological and histochemical characterization of the mucosa of the digestive tract in Engraulis anchoita.

The histomorphological aspects as well as the histochemical content and distribution of glycoproteins (GPs) in the mucosa of the digestive tract of the anchovy Engraulis anchoita were studied. The buccopharyngeal cavity is lined by a squamous stratified epithelium with mucous superficial cells; the oesophagus shows two zones, cranial with a squamous stratified epithelium with mucous superficial cells and caudal with a columnar secretory epithelium. Finally, the stomach presents both the cranial and pyloric portion lined with a simple columnar epithelium. Tubular branched glands, formed by a single type of glandular cell, located along the stomach, are more numerous in the cranial portion. The GPs were identified with (1) oxidizable vicinal diols; (2) sialic acids and some of their chain variants, C7 or C9; (3) sialic acid residues with O-acyl substitution at C7 or C8; (4) carboxyl groups and (5) sulphate groups. Histochemical tests showed that the buccopharyngeal cavity presented the largest amount of the different types of mucosubstances. Epithelial secretory cells were found in the oesophagus, which synthesized a large quantity of sialosulphoglycoproteins likely to be related to a protective role. The surface epithelium of the stomach synthesizes and secretes acid and neutral GPs, probably related to the movement of fluids and to the absorption of easily digested substrates, respectively. Although great differences exist between different species, in E. anchoita as in other fish species, the wall of the digestive tract is composed of the four layers classically described for vertebrates. The GPs secreted by the epithelial cells are suggested to be important for the protection and inhibition of microorganisms. In addition, they are involved in enzymatic digestion of food, absorptive functions and lubrication of the alimentary tract.

Animals↗
PubMed1977

Development of bacterial plaque in the oral cavity.

Dental plaque may be defined as bacterial aggregations upon the teeth and other solid structures inserted in the oral cavity. It is formed by oral microorganisms which attach to the teeth in sheltered areas along the gingival margin, on the approximal surfaces, and in pits and fissures on the masticatory surfaces. The plaque increases in quantity either by multiplication of already attached organisms, or by continuous addition to the deposits of bacteria from the saliva. Structural analyses indicate that the organisms are held together in an exracellular matrix partly produced by the organisms and partly derived from saliva. The microflora of plaque is complex and shows great individual variation. There are also characteristic differences in plaque from different sites on the teeth. Thus dento-gingival plaque is qualitatively different from that of the occlusal fissures. Furthermore, the relative proportion of different types of microorganisms may vary with the age of the deposit. Such information must be taken in consideration when attempts are made to develop chemical agents for the purpose of inhibiting plaque formation in order to prevent periodontal disease and caries.

Dental Plaque↗
PubMed1988

Treatment of angular cheilitis. The significance of microbial analysis, antimicrobial treatment, and interfering factors.

This prospective study evaluated the significance of microbial analysis and antimicrobial treatment for the cure of angular cheilitis. Furthermore, various etiologic factors were investigated for their relative effect on the healing process. The study included 1) an open trial with 50 patients infected by Candida albicans and/or Staphylococcus aureus, and 2) an intraindividual comparison of eight patients with bilateral lesions infected by Candida albicans as the only detected pathogen. After a base-line examination the patients received ointments containing nystatin and/or fusidic acid, on the basis of the outcome of an initial microbial analysis. The patients were evaluated clinically, photographed, and examined for microorganisms at different time intervals. Ninety-six per cent of the patients who participated in the open trial had no sign of infection after 42 days of treatment. Lesions in the double-blind study, treated with nystatin, were healed after 28 days, whereas lesions that received placebo persisted throughout the treatment period. Increasing age, dry skin, and extended skinfolds at the corner of the mouth were factors closely related to the length of the healing process.

Adult↗
PubMed2000

[The changes of oral conditions caused by artificial crown contours in severely disabled patients].

The purpose of this study was to investigate the relation between the artificial crown contour and plaque accumulation in severely disabled patients who have muscle hypoactivity in the oral region. This relation was statistically analyzed by the change in CFU numbers of Mutans Streptococci, Lactobacillus, and total anaerobic bacteria. The results were as follows: 1. In the severely disabled group, there was no significant difference in the decrease of number of microorganisms between with and without tooth brushing. When the normal contour crown was exchanged for the under contour, however, the numbers of Mutans Streptococci and total anaerobic bacteria decreased significantly (p < 0.05). 2. In the normal control group, both the crown contour and tooth brushing were effective for decreasing the number of Mutans Streptococci and total anaerobic bacteria (p < 0.05). 3. In both groups, the number of Lactobacillus was decreased by changing the crown contours and by tooth brushing, with no statistical significance. 4. In view of the cariogenic potential of microorganisms, it is concluded that the under contour crown prevents plaque accumulation, and that this crown should be used on severely disabled patients, as it makes tooth brushing more effective.

Adult↗
PubMedDate not supplied

[Study of probiotic properties of bacteriocinogenic Lactobacillus plantarum G3/3(13) strain].

Bacteriocinogenic culture Lactobacillus plantarum G3/3(13) was tested according to the basic requirements to probiotic strains. The reidentification of the strain was carried out using a set of methods including PCR. It was confirmed that the strain belongs to the species L. plantarum. The studied culture expressed antagonistic activity with respect to Enterococcus faecalis and E. faecium. The susceptibility test to 57 antibiotics of different groups showed that the strain was resistant to oxacillin, cefepyme, lomefloxacin, polymyxin, nalidixic acid and the antifungal antibiotics. High adhesive properties of the microorganism to the human epithelial cells (medium adhesion index was 4.6-5.6; microorganism adhesion index was 4.9-5.9) were shown. Obtained results allow to recommend L. plantarum G3/3(13) for the construction of probiotics.

Anti-Bacterial Agents↗
PubMed1984

The effects of mutual interaction and host diet on the growth rates of the bacteria Actinomyces viscosus and Streptococcus mutans during colonization of tooth surfaces in di-associated gnotobiotic rats.

The bacteria were simultaneously inoculated into the mouths of germ-free rats. The maximum growth rates attained by Strep. mutans (doubling time td = 1.4 h) or A. viscosus (td = 2.7 h) were approximately the same as in mono-associated gnotobiotic rats [td = 1.1 and 2.8 h, respectively (Beckers and van der Hoeven, 1982a)]. The presence of glucose or sucrose did not affect the maximum growth rates. In starved rats, the accumulation of microorganisms tended to decline sooner, suggesting that the growth was limited by the availability of nutrients. No interaction between the two organisms was detected at the stage of initial adherence to the tooth surfaces or during the first 24 h of growth. After that, the increase of A. viscosus was retarded in the presence of Strep. mutans T2, but not with Strep. mutans OMZ176. The retardation was more pronounced in the rats fed on glucose than on sucrose. Yet, at 24 days after inoculation. A. viscosus had increased in the glucose more than in the sucrose group. Hence sucrose did not stimulate the accumulation of Strep. mutans more than glucose.

Actinomyces↗
PubMed1999

The human cationic antimicrobial protein (hCAP18), a peptide antibiotic, is widely expressed in human squamous epithelia and colocalizes with interleukin-6.

Peptide antibiotics are widespread in nature and, by providing a rapid first line of defense, may be key players in the innate immune system. Although epithelia are the main barriers shielding the internal environment from microorganisms, the role for peptide antibiotics in epithelial protection is unclear. We recently reported that the human cationic antimicrobial protein hCAP18, the precursor of the antimicrobial peptide called LL-37, is not expressed by normal human keratinocytes but is induced in various inflammatory skin disorders. In the present study we demonstrate that hCAP18 is consistently expressed at both mRNA and protein levels in squamous epithelia of the mouth, tongue, esophagus, cervix, and vagina in humans. The gene for hCAP18 contains promoter elements that are potentially regulated by interleukin-6, and our data further show a colocalization between interleukin-6 and hCAP18 expression in these tissues. Our finding that hCAP18 is widely produced in squamous epithelia suggests a role for this peptide in epithelial antimicrobial defense. Furthermore, colocalization with interleukin-6 indicates a potential local mechanism for the upregulation of hCAP18 at the epithelial surfaces.

Anti-Bacterial Agents↗
PubMed1994

Arginine metabolism in the salivary glands of protein-deficient rats and its potential association with the oral microflora.

Salivary glands and their secretions play key roles in the prevention of dental diseases. The antibacterial and physicochemical properties of saliva are compromised in chronic malnutrition. The present study has examined the possibility that some malnutrition-induced changes in salivary gland function are potentially capable of promoting growth and metabolic activities of pathogenic oral microorganisms. Compared to well-fed controls, rats fed a 3% protein diet for 18 days showed a significant reduction (p < 0.001) in the submandibular gland arginase (L-arginine amidinohydrolase, EC 3.5.3.1) activity. Associated with the latter finding was a marked increase (+85%) in the glandular level of free arginine, this basic amino acid accounting for 12.2% of the total essential amino acids as compared with a figure of only 4.6% for the controls. The total free amino acid pool in whole saliva was relatively unaffected by malnutrition, but the levels of the basic amino acids arginine and histidine were marginally increased. Many oral bacterial species, some of which are dominant plaque microorganisms, utilize the arginine deiminase (EC 3.5.3.6) pathway. Thus, increased availability of free arginine from salivary glands offers a plausible explanation for the frequently reported observation of differential overgrowth of several potentially pathogenic microorganisms including some mutants streptococci in protein-deficient laboratory animals and may well apply to similar findings in malnourished populations in Third World countries.

Amino Acids, Essential↗
PubMed1993

Impact of cefpodoxime proxetil and amoxicillin on the normal oral and intestinal microflora.

Ten healthy volunteers were given 200 mg cefpodoxime proxetil tablets every 12 h and ten volunteers received 500 mg amoxicillin tablets every 8 h for seven days and the impact of the agents on the oral and intestinal microflora was studied. In the oral microflora, only minor alterations were observed in both groups. In subjects receiving cefpodoxime proxetil, the numbers of streptococci, enterobacteria and clostridia were strongly reduced in the faecal flora, while there was an overgrowth of enterococci, yeasts and Clostridium difficile. Amoxicillin administration induced somewhat smaller alterations in the faecal microflora, although all subjects had overgrowth of new colonizing amoxicillin resistant microorganisms, mainly Escherichia coli, Klebsiella and Enterobacter. Beta-lactamase activity was detected in the flora of six volunteers from each group.

Adult↗
PubMed2005

Development and characterization of an animal model of dental sinusitis.

CONCLUSION: The results of this study confirm that the present rabbit model of dental maxillary sinusitis (dMxS) is reproducible and simulates human dental sinusitis with respect to initiation, progression and inflammation. It is applicable to further studies of sinusitis of odontogenic origin. OBJECTIVES: To induce acute dMxS in rabbits by using their own oral microflora to create a periapical infection and to follow morphological, radiographic, bacteriological and histological changes to the sinus mucosa. MATERIAL AND METHODS: The experimental animals comprised 26 New Zealand White rabbits. Maxillary premolar root canals were identified bilaterally and the continuously growing germs of the roots were severed by diathermy. The animals were randomized into 2 groups: in Group 1 (n=20) the teeth were left open for the entire study period; in Group 2 (n=6) the root canals were sealed 1 week after the initial intervention. The animals in Group 1 were sacrificed at intervals ranging from 2 h to 9 months after intervention. All animals in Group 2 were sacrificed 6 months after intervention. After macroscopic and radiographic examination, post-mortem inspection of the paranasal sinus cavity and maxillary complex and microbiological sampling, the entire nasal sinus complex with the hard palate in situ was resected and processed for serial coronal sectioning. RESULTS: In Group 1, after 3 months, the radiographic changes ranged from widening of the periodontal space to bone reaction. At sacrifice, changes in the sinus mucosa ranged from signs of mucosal inflammation to purulent dMxS. Microbial growth, predominantly Gram-negative aerobes, increased over time. In Group 2, the findings were generally more pronounced. Anaerobic microorganisms were predominant. In both groups the findings were consistent with dMxS.

Animals↗
PubMed1984

Clindamycin in the upper respiratory tract infections.

Bacterial infections of the upper respiratory airways are common. Some of these infections are caused by anaerobic bacteria and Staphylococcus aureus and may constitute considerable therapeutical problems. Chronic suppurative otitis media may sometimes give rise to serious osteitis of surrounding bone structures, sigmoid sinus thrombosis and intracranial abscesses. The causative microorganisms are mostly anaerobes. Many paranasal sinus infections are also due to anaerobic bacteria. These infections can rapidly cause irreversible damage of the sinus mucosa and eventually spread intracranially. Purulent parotitis is mostly seen in elderly and seriously ill patients. In the majority of the cases bacterial cultures reveal beta-lactamase-producing S. aureus. Infections of the teeth in the mandible sometimes spread into the floor of the mouth and may extend down into the throat and mediastinum. If not properly treated these anaerobic infections will prove fatal. Chronic osteomyelitis of the mandible is increasing in frequency and constitute serious therapeutical problems. Many patients cannot be protected against painful and disabling relapses. Anaerobic bacteria, emanating from the normal oropharyngeal flora, play an important part in the pathogenesis of this disorder. Retropharyngeal, parapharyngeal as well as peritonsillar infections and abscesses are mostly caused by anaerobes and demand adequate surgical and antibacterial therapy. In malignant tumors of the ear, nose or throat, anaerobic infections often deteriorate the conditions as inflammatory oedema increases the volume of the tumor and the pain of the patients. Cutaneous infections of the face and auricles caused by S. aureus may constitute therapeutical problems.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1999

Disinfection of denture base acrylic resin.

STATEMENT OF PROBLEM: During repair or adjustments of acrylic resin removable complete and partial dentures, particles of the acrylic resin from the interior of the prosthesis may expose dental personnel to microbial health hazards if the prosthesis has not been thoroughly disinfected. PURPOSE: This study investigates the efficacy of a commercially prepared microbial disinfectant (Alcide) on the external and internal surfaces of acrylic resins. MATERIAL AND METHODS: Four groups of acrylic resin were incubated in an experimental model to simulate the oral environment over time. Specimens were treated in 2 groups, disinfected and not disinfected, and then further grouped by breaking and not breaking. Analysis was performed with microbial colony counts, SEM, and statistical analyses. RESULTS: Viable microorganisms still remain on the internal and external surfaces of treated resins. CONCLUSION: Chlorine dioxide reduces, but does not eliminate, viable microorganisms on these dental prostheses.

Acrylic Resins↗
PubMed2002

Bronchopneumonia and oral health in hospitalized older patients. A pilot study.

AIMS: To correlate microbial findings obtained by bronchoalveolar lavage in pneumonia patients with the clinical situation of the oral cavity. METHOD: Quantitative aerobic and anaerobic cultures were carried out in 150 ml samples of bronchoalveolar lavage (BAL) obtained by means of an endoscope (Video Endoscope Pentax) inserted per os in the infected bronchus. MATERIAL: Twenty consecutive patients with a tentative clinical diagnosis of bronchopneumonia in whom BAL was carried out for diagnostic purposes. A clinical evaluation of the oral health status (oral hygiene, caries, periodontal diseases) was subsequently carried out. RESULTS: In seven edentulous subjects wearing complete dentures the culture of anaerobic microorganisms was negative or yielding less than 100 cfu/ml BAL. Two patients yielded high counts of S. aureus and one high counts of P. aeruginosa. In the 13 subjects with natural teeth left one showed high counts of Veillonella spp. (anaerobic) + P. aeruginosa, one high counts of Veillonella spp. + S. aureus, one high counts of P. aeruginosa + S. aureus and one high counts of E. coli. These four subjects showed poor oral hygiene, periodontal pockets and a BAL microflora consistent with periodontal pathology. CONCLUSION: The results of this pilot study suggest that microorganisms of denture plaque or associated with periodontal diseases may give rise to aspiration pneumonia in susceptible individuals.

Aged↗
PubMed1989

[The effect of mouthwash on oral malodour production].

Volatile sulphur compounds (VSC), hydrogen sulphide, methyl mercaptan and dimethyl sulphide are by-products derived in oral cavity through putrefactive activity of microorganisms. VSC are the principal cause of physiological oral malodour. There are indications that these compounds are cytotoxic to oral tissues. Hence, it has been considered that the prevention of oral malodour has an important role in preventive dentistry. The objective of this study is to ascertain the effect of two mouthwashes, sodium azulenesulphonic acid and povidone-iodine, which are frequently used in dental clinics, on concentration of VSC in mouth air. The VSC were analyzed using VSC analysis system. VSC were determined at immediately after rince and at one, two and three hours after rince. The results indicated that neither mouthwash was very effective in controlling VSC production. No reduction in VSC was observed at one and two hour post-rinsing with sodium azulenesulphonic acid mouthwash, and only 39% reduction of total sulphur of VSC was observed at one hour following the use of the povidone-iodine containing products. However, this effect was lost within two hours post-rinsing.

Azulenes↗
PubMed1994

Mucin-sulphatase activity of some oral streptococci.

Mucin-sulphatase activity, measured using a 35S-[SO4(2-)]-labelled colonic mucin substrate, was detected in whole cells of Streptococci isolated from the human oral cavity. The highest levels of sulphatase activity were found in all strains of Streptococcus salivarius, Streptococcus mitis and in half of the strains of Streptococcus mutans tested. Little or no activity was detected in 9 of the 11 Streptococcus oralis strains examined, in the 4 Streptococcus constellatus strains, and in the 3 Streptococcus anginosus isolates tested. The highest enzyme levels were obtained from the two fresh Streptococcus gordonii isolates. This is the first report of such activity in oral microorganisms. Streptococcal mucin-sulphatase may contribute to the destruction of salivary mucins and mitigate their protective functions in the oral cavity, and be a determinant in the development of dental caries.

Culture Media↗
PubMed1990

[Secretory immune response in the oral cavity].

Secretory IgA antibodies may modulate colonization of the epithelial and dental surfaces by different species of microorganisms. The application of enteric vaccines may probably permit controlling caries frequency infants and children. However, the complexity of bacterial communities involved in inflammatory periodontal diseases, currently prevent developing strategies aimed at preventing these processes through immunological mechanisms.

Dental Caries↗
PubMed2004

Relationship between oral motor dysfunction and oral bacteria in bedridden elderly.

OBJECTIVE: The purpose of this study was to analyze the relationship between oral bacterial colonization and oral motor dysfunction. STUDY DESIGN: Oral motor dysfunction (swallowing and speech disorders) and detection of oral bacterial species from dental plaque in 55 elderly persons who had remained hospitalized for more than 3 months were investigated and statistically analyzed. RESULTS: The detection rates of methicillin-resistant Staphylococcus aureus (MRSA), Pseudomonas aeruginosa, Streptococcus agalactiae, and Stenotrophomonas maltophilia were significantly higher in subjects with than in those without a swallowing disorder. A similar result was found with regard to the presence of a speech disorder. About half of subjects who had oral motor dysfunction and hypoalbuminemia had colonization by MRSA and/or Pseudomonas aeruginosa. CONCLUSION: These results suggest that the combination of oral motor dysfunction and hypoalbminemia elevated the risk of opportunistic microorganisms colonization in the oral cavity of elderly patients hospitalized over the long term.

Aged↗