Biomedical subjects

M Pauwels

Publications and source records attributed to M Pauwels.

At least 19 recordsLinked to original sources

PubMed2005

Influence of genetic background on transformation and expression of Green Fluorescent Protein in Actinobacillus actinomycetemcomitans.

BACKGROUND/AIMS: The development of an electro-transformation system and the construction of shuttle plasmids for Actinobacillus actinomycetemcomitans have enhanced the molecular analysis of virulence factors. However, inefficient transformation is frequently encountered. This study investigated the efficiency of electro-transformation and expression of Green Fluorescent Protein (GFP) in 12 different A. actinomycetemcomitans strains. The influence of the plasmid vector, serotype, and phenotype were the major factors taken into consideration. MATERIAL AND METHODS: Twelve serotyped A. actinomycetemcomitans strains were independently electro-transformed with two different Escherichia coli-A. actinomycetemcomitans shuttle plasmids (pVT1303 and pVT1304), both containing an identical ltx-GFPmut2 gene construct but a different backbone (pDMG4 and pPK1, respectively). The transformation efficiency, transformation frequency, and electro-transformation survival rate were determined by culture techniques. GFP expression was observed at the colony level by fluorescence microscopy. RESULTS: All strains could be transformed with both plasmids. However, major differences were observed for the transformation efficiency, transformation frequency, and electro-transformation survival rate between strains. The data demonstrated that plasmid vector, serotype, and phenotype are key players for obtaining a successful transformation. An inverted relationship between the electro-transformation survival rate and tranformation frequency was also observed. GFP expression was also influenced by phenotype, serotype and plasmid vector. CONCLUSIONS: The serotype of A. actinomycetemcomitans has an important influence on its survival after electro-transformation and on transformation frequency. The expression of GFP is strain and plasmid vector dependent.

Aggregatibacter actinomycetemcomitans↗

PubMed2005

Increase in cariogenic bacteria after initial periodontal therapy.

This study examined the hypothesis of an intra-oral shift, during initial periodontal therapy, from a periopathogenic to a cariogenic flora. Seventy-one patients with periodontitis were randomly allocated to one of the following treatment strategies: (1) scaling and root planing, quadrant by quadrant, at two-week intervals (NC); (2) full-mouth scaling and root planing within 24 hrs (FRP); or (3) full-mouth disinfection within 24 hrs, including antiseptics [chlorhexidine (CHX) or amine fluoride/stannous fluoride (F) for 2 mos, or CHX for 2 mos followed by F for 6 mos (CHX+F)]. At baseline and after 2, 4, and 8 mos, bacterial samples were taken from supra- and subgingival plaque, saliva, and tongue. The detection frequencies and relative proportions of Streptococcus mutans increased in the NC and FRP groups, but decreased in the F group. In the CHX group, these species disappeared temporarily, but they disappeared for the entire 8 mos in the CHX+F group. These observations were similar for all sample locations. The periopathogens decreased in all groups. This finding confirms the abovementioned hypothesis and indicates a need for caries prophylactic regimens.

Adult↗

PubMed2005

Initial subgingival colonization of 'pristine' pockets.

The treatment of periodontitis/peri-implantitis involves the reduction/eradication of periopathogens. After therapy, beneficial and pathogenic species recolonize the subgingival area. The dynamics of recolonization and especially the role of the supragingival environment in this process are still not well-understood. This prospective, split-mouth study followed the early colonization of 'pristine' pockets created during implant surgery (16 partially edentulous patients), to record the time needed before a complex subgingival flora could be established with the supragingival area as the single source. Four subgingival plaque samples were taken from shallow and medium pockets around implants (test), and neighboring teeth (undisturbed microbiota as reference) 1, 2, and 4 wks after abutment connection. Checkerboard DNA-DNA hybridization and culture data revealed a complex microbiota (including several pathogenic species) in the pristine pockets within a wk, with a minimal increase in counts up to 4 wks. Analysis of these data demonstrated that, even with the supragingival environment as the single source for colonizing bacteria, a complex subgingival microbiota can develop within 1 wk.

Adult↗

PubMed2004

Impact of tongue cleansers on microbial load and taste.

OBJECTIVES: Tongue cleaning has been advocated to improve oral malodor and to reduce reinfection of periodontal niches by eliminating tongue coating and/or reducing putrefaction by bacteria. MATERIAL AND METHODS: This cross-over, single-blind study on periodontitis-free, non-smoking, subjects with habitual oral hygiene (n=16), evaluated the effect of tongue cleaning (with either plastic scraper or nylon multi-tufted toothbrush), on the microbial load of the tongue dorsum (anterior and posterior of the sulcus terminalis), the extent of tongue coating, and taste sensation for bitter, sweet, salt, and sour. Both devices had been used twice daily for 2 weeks (toothbrush three forward-backward movements along the linea mediana and for each longitudinal third of the tongue; two strokes with the scraper along the linea mediana and along the borders of the tongue). RESULTS: Two weeks of tongue brushing or scraping resulted in only negligible reductions in aerobic and anaerobic bacteria on the tongue (reductions <0.5 log). The amount of tongue coating, however, decreased significantly (p<0.05), with both devices. The taste sensation improved after 2 weeks of tongue cleaning, especially with the scraper (significant improvements for quinine and sodium chloride). CONCLUSION: Tongue cleaning improves taste sensation and seems to reduce the substrata for putrefaction, rather than the bacterial load.

Adult↗

PubMed2003

Image-based planning and clinical validation of zygoma and pterygoid implant placement in patients with severe bone atrophy using customized drill guides. Preliminary results from a prospective clinical follow-up study.

The zygoma implant has been designed for those situations where there is insufficient bone in the upper jaw, which would otherwise require onlay or inlay (sinus) bonegrafts. The aim of the study was to present and validate a planning system for implant insertion based on preoperative CT imaging. It allows the surgeon to determine the desired position of different kinds of implants. Finally a customized drill guide is produced by stereolithography. In this study, zygoma, pterygoid and regular platform implants were used. The treatment protocol is validated through 12 case studies, selected at random from the total patient group (n=29 patients). From postoperative images, the exact implant location is determined and the deviation of axes between planned and inserted implants is calculated. In this in vivo study, displacements, varying according to the type of implant and the location of the implants, were observed. From a clinical standpoint, most of the inserted implants were judged to be adequately sited. A prospective clinical follow-up study was performed on all 29 patients. Although all patients presented with severe maxillary atrophy, excellent cumulative survival rates (92%) for the zygoma implants and 93% for regular platform implants have been obtained.

Adult↗

PubMed2002

Remediastinoscopy after neoadjuvant therapy for non-small cell lung cancer.

Despite technical difficulties due to mediastinal fibrosis, remediastinoscopy can be a valuable tool in the restaging of non-small cell lung cancer after neoadjuvant therapy. The aim of our study was to evaluate the feasibility, sensitivity and accuracy of remediastinoscopy. From November 1994 to July 2001 we performed a remediastinoscopy in 27 patients after neoadjuvant therapy. Their age ranged from 35 to 80 years (mean 61.9+/-11.9). In all 27 patients it was possible to perform a remediastinoscopy without major technical difficulties and take biopsies of the lymph nodes that were initially invaded by tumour. Remediastinoscopy was positive in 11 patients (40.7%) and negative in 16 (59.3%). In the 11 patients with a positive remediastinoscopy a complete resection was not judged possible and therefore, an unnecessary thoracotomy was avoided. In four patients, remediastinoscopy turned out to be false negative. So, in our series, sensitivity was 73%, specificity 100% and accuracy 85%. The positive and negative predictive values were 100 and 75%, respectively. Previous mediastinoscopy is no contra-indication for a repeat one after neoadjuvant therapy. Although sensitivity and accuracy are lower than that of a first mediastinoscopy, remediastinoscopy is useful to select patients for surgical resection after induction therapy.

Adult↗

PubMed2002

Viability of cultured periodontal pocket epithelium cells and Porphyromonas gingivalis association.

OBJECTIVES: Porphyromonas gingivalis, one of the key pathogens in the development of periodontitis, produces a number of virulence factors that might explain its pathogenicity. One of them is the ability to adhere and invade pocket epithelium. The aim of this study was to follow, over time, the association of P. gingivalis and consequent morphological changes of the pocket epithelium cells. MATERIAL AND METHODS: The association capacity of four P. gingivalis serotypes [K1, K2, K4, K- (nonencapsulated)] with in vitro cultured mono-layers from periodontal pocket epithelial cells of patients with periodontitis, was followed by fluorescence microscopy and bacterial culture. The contact time between bacteria and epithelium cells ranged from 45 min to 8 h. The microscopic evaluation allowed differentiation between dead and living cells (bacteria as well as epithelium) and description of the morphological changes after association. RESULTS: A highly significant difference in the number of associating bacteria was found between dead and living epithelium cells, and between non-capsulated and capsulated strains. A significant increase in the proportion of dead pocket epithelium cells was found with prolonged association time. The morphological changes (rounding of the epithelial cell, detachment from the glass cover-slip and loss of intercellular contact) occurred faster for mono-layers inoculated with the non-encapsulated P. gingivalis strain. CONCLUSIONS: This study indicates that dead pocket epithelium cells harbor more P. gingivalis cells, and that a positive correlation exists between contact time and cell death. For the P. ginigvalis species, non-encapsulated strains associate in higher number. As a result, the damage they cause to the host cell seems to occur faster than occurs in encapsulated strains. As such, cell death can be seen as the end-result of bacterial association.

Bacterial Adhesion↗

PubMed2001

Bacterial survival rate on tooth- and interdental brushes in relation to the use of toothpaste.

BACKGROUND, AIMS: Previous studies indicated that oral hygiene aids can play a rôle in the intra-oral translocation of pathogens. The survival rate of cariogenic and periodontopathogenic species on toothbrushes, with and without toothpaste, and interdental brushes was presently investigated. MATERIAL AND METHODS: 12 periodontitis patients had their interdental spaces professionally cleaned with interdental brushes and their teeth with new toothbrushes with or without different dentifrices. Each time brushes were rinsed with tap water and stored dry at room temperature. At different time intervals an interdental brush or 4 tufts from a toothbrush were processed for vitality staining and selective and non-selective culturing procedures. RESULTS: Immediately after rinsing, a toothbrush without toothpaste harboured 10(7), 10(8) and 10(7) colony forming units (CFU) of respectively aerobic, anaerobic and black pigmented species. An insignificant decrease occurred the first 24 hours and after 48 hours still 10(4) CFU of aerobic and anaerobic species could be cultured. No periodontopathogen remained detectable at 8 hours, except for Fusobacterium nucleatum. The proportion of vital bacteria decreased in 48 hours from 50% to 30%. Comparable results were obtained for interdental brushes. The bacterial survival rate on toothbrushes was significantly reduced by the use of a detergent containing toothpaste by 2 log at baseline, another 2 log at 4 hours and an extra log more at 8 hours for aerobic and anaerobic species. A toothpaste without detergent only had an insignificant bactericidal effect. CONCLUSION: Toothpaste detergents decrease the survival rate of pathogenic species on a toothbrush and can thus limit the risk for bacterial translocation.

Adult↗

PubMed2001

Effect of different chlorhexidine formulations in mouthrinses on de novo plaque formation.

BACKGROUND: Chlorhexidine (CHX) 0.2% solution, still the golden standard as mouthrinse for the prevention of plaque formation and development of gingivitis, has some limited side-effects such as extrinsic tooth staining, poor taste, taste disturbance, sensitivity changes in tongue, pain, and the content of alcohol. These side effects led to the search of new formulations. METHODS: In this double-blind, randomised, cross-over study, 16 young dental students with a healthy periodontium, abolished all means of mechanical plaque control during 4 experimental periods of 11 days (separated from each other by a washout period of 3 weeks). During each experimental period, they rinsed 2x daily with one of the following mouthrinses in a randomised order: CHX 0.2% + alcohol (Corsodyl), CHX 0.12% + alcohol (Perio.Aid), CHX 0.12% + sodium fluoride 0.05% (Cariax Gingival) and CHX 0.12% + CPC 0.05% (Perio.Aid, new formulation). After 7 and 11 days of undisturbed plaque formation, clinical parameters were recorded, questionnaires completed and plaque samples (supragingivally and saliva) collected. RESULTS: The CHX 0.12% + alcohol and the CHX 0.12% + CPC 0.05% formulations were as efficient as the CHX 0.2% mouthrinse in retarding de novo plaque formation (proven by clinical observations as well as by anaerobic and aerobic culture data), and always superior (p<0.001) to the CHX 0.12% + sodium fluoride 0.05% solution. The subjective ratings were in favour of the new CHX formulation when compared with the other CHX formulations, especially for taste (p<0.05). CONCLUSIONS: The results of this study demonstrated the potential of a new CHX 0.12% + CPC 0.05% non-alcoholic formulation as an effective anti-plaque and anti-inflammatory agent with reduced unpleasant subjective side-effects.

Adult↗

PubMed2001

Altered antioxidant defence in a mouse adriamycin model of glomerulosclerosis.

BACKGROUND: Antioxidant enzyme status changes in experimental models of chronic renal disease with glomerulosclerosis. Most of the studies are performed in rats. We now investigate whether a mouse model with more rapid development of glomerulosclerosis is suitable for the study of radical-associated renal disease. METHODS: Female BALB/c mice are injected intravenously with a single dose of adriamycin (10 mg/kg). The development of glomerular and interstitial injury is evaluated by means of renal function parameters and histology. Renal cortex activities of catalase, Cu/Zn and Mn superoxide dismutase and glutathione peroxidase are measured by enzymatic techniques, and their mRNA levels by Northern blot analysis. RESULTS: The mice develop proteinuria and hypercholesterolaemia; glomerulosclerosis is present 20 days after adriamycin injection. Involvement of reactive oxygen intermediates in the disease process is supported by an increased cortex level of glutathione (1.77+/-0.13 vs 1.31+/-0.12 micromol/g kidney; P = 0.021) and ferric iron deposition in the tubulointerstitial compartment. Glomerulosclerosis and tubulointerstitial lesions are accompanied by decreased cortex activities of catalase (0.19+/-0.01 vs 0.23+/-0.01 U/mg protein; P = 0.024), glutathione peroxidase (0.28+/-0.01 vs 0.32+/-0.01 U/mg protein; P = 0.049) and Mn superoxide dismutase (6.61+/-0.91 vs 9.25+/-0.99 U/mg protein, P = 0.020). We find decreased cortex mRNA levels only for glutathione peroxidase. CONCLUSION: The fast development of glomerulosclerosis combined with an altered antioxidant status makes this mouse adriamycin model a suitable alternative for the slower rat models.

Animals↗

PubMed2001

Weight reduction by means of intragastric device: experience with the bioenterics intragastric balloon.

BACKGROUND: A new intragastric balloon is available for weight reduction. METHODS: Patients consulting for a weight reduction plan and refusing any kind of actual surgery, or suffering from obesity but not meeting the IFSO standards for surgery, were offered the possibility of weight reduction by the BioEnterics intragastric balloon (BIB). A preoperative questionnaire was completed by all patients, inquiring about medical history, co-morbidity factors, dietary habits, previous treatments for weight and social, psychological, relational and economic impact of the obesity. BIB placement was done on an inpatient basis, under general anesthesia. Inflation was standardized at 500 ml saline. Intravenous antiemetic and spasmolytic drugs were given to control post-insertion nausea for 24 hours, and oral medication was administered on the patient's discharge. A standard 800 calorie diet was prescribed after dietitian's consultation. Extraction of the balloon was left to the patient's discretion at 3 or maximum 6 months after placement. Patients choosing for the maximal period received a formal invitation to extract the balloon. Evaluation of weight reduction was done at extraction and by questionnaire. RESULTS: 126 patients (5 M, 121 F) with mean age of 35.6 years (20-62) were included after preoperative evaluation. Mean preoperative BMI was 37.7 kg/m2 (26.7-57.7 kg/m2), with a mean initial excessive weight of 35.3 kg (8.8-96.4 kg) and mean initial % excess weight of 32.2 (6.3-102). 69 patients were eligible for review; mean excess weight loss after 3 months was 48.6% and after 6 months 50.8%. Mean weight loss was 15.4 kg (0-35 kg). 76.8% of the patients (41/69) complained of severe nausea and vomiting lasting an average of 1 week (1 day-6 months), resulting in 3 patients in early removal of the balloon (at 1 day, 1 week, 1 month after placement respectively). 2 patients suffered gastric perforation presenting as acute peritonitis 3 and 4 months after placement and were operated. Extraction of the balloon was performed in 3 patients after 3 months and in 66 patients after 6 months. In 11 patients (22%), esophagitis was present (8 grade 1, 2 grade II, 1 grade III), and one patient showed diffuse gastric erosion. One patient required removal of the balloon by rigid esphagoscopy following technical failure of the endoscopic extraction device. 45 patients replied to the mailed, questionnaire; 15% (7/45) were very satisfied, 13% (6/45) satisfied, 22% (10/45) reasonably satisfied, 8.8% (4/45) unsatisfied and 40% very unsatisfied. Degree of satisfaction correlated poorly with weight loss. Results may be better with close continuous guidance by a counselor. CONCLUSION: BIB as a means of weight reduction in the obese patient led to a 50.8% loss of excess weight after 6 months. Although severe morbidity can occur, the BIB provides a means for short-term weight reduction in conjunction with dietary measures.

Adult↗

PubMed2001

Effect of different mouthrinses on morning breath.

BACKGROUND: Morning breath odor is an often-encountered complaint. This double-blind, crossover, randomized study aimed to examine the bad breath-inhibiting effect of 3 commercially available mouthrinses on morning halitosis during an experimental period of 12 days without mechanical plaque control. METHODS: Twelve medical students with a healthy periodontium refrained from all means of mechanical plaque control during 3 experimental periods of 12 days (with intervening washout periods of at least 3 weeks). A professional oral cleaning preceded each period. During each experimental period, as the only oral hygiene measure allowed, the students rinsed twice a day with one of the following formulations in a randomized order: CHX-Alc (a 0.2% chlorhexidine [CHX] solution); CHX-NaF (CHX 0.12% plus sodium fluoride 0.05%); or CHX-CPC-Zn (CHX 0.05% plus cetylpyridinium chloride 0.05% plus zinc lactate 0.14%). After 12 days, morning breath was scored via volatile sulfur compound (VSC) level measurements of the mouth air and organoleptic ratings of the mouth air, the expired air, and a scraping of the tongue coating. At the 12-day visit, a questionnaire (subjective ratings) was completed and samples taken from both the tongue coating and the saliva for anaerobic and aerobic culturing and vitality staining. The de novo supragingival plaque formation was also recorded. All parameters were correlated with the baseline registrations. RESULTS: Although oral hygiene during the 3 experimental periods was limited to oral rinses, bad breath parameters systematically improved, with the exception of a slight increase in VSC levels while using CHX-Alc, a finding which was associated with the direct influence of the CHX on the sulfide monitor. The oral microbial load after the use of CHX-NaF remained unchanged, while for the CHX-Alc and CHX-CPC-Zn, significant reductions in both aerobic and anaerobic colony forming units (CFU)/ml were noticed in comparison with baseline data for both tongue coating and saliva samples. The composition of microflora, on the other hand, did not reveal significant changes. The supragingival plaque formation was inhibited, in descending order, by CHX-Alc, CHX-CPC-Zn, and CHX-NaF. The subjective scores for the rinses indicated a higher appreciation for CHX-CPC-Alc and CHX-NaF because of a better taste and fewer side effects. CONCLUSIONS: The results of this study demonstrate that morning halitosis can be successfully reduced via daily use of mouthrinses. CHX-Alc and CHX-CPC-Zn mouthrinses result in a significant reduction of the microbial load of tongue and saliva.

Adult↗

PubMed2000

The rôle of chlorhexidine in the one-stage full-mouth disinfection treatment of patients with advanced adult periodontitis. Long-term clinical and microbiological observations.

BACKGROUND/AIMS: Recent studies reported significant additional clinical and microbiological improvements when severe adult periodontitis was treated by means of a "one-stage full-mouth" disinfection instead of a standard treatment strategy with consecutive root planings quadrant per quadrant. The one stage full-mouth disinfection procedure involves scaling and root planing of all pockets within 24 h in combination with an extensive application of chlorhexidine to all intra-oral niches such as periodontal pockets, tongue dorsum, tonsils (chairside, and at home for 2 months). This study aims to examine the relative importance of the use of chlorhexidine in the one stage full-mouth disinfection protocol. METHODS: Therefore, 3 groups of 12 patients each with advanced periodontitis were followed, both from a clinical and microbiological point of view, over a period of 8 months. The patients from the control group were scaled and root planed, quadrant per quadrant. at two-week intervals. The 2 other groups underwent a one stage full-mouth scaling and root planing (all pockets within 24 h) with (Fdis) or without (FRp=full-mouth root planing) the adjunctive use of chlorhexidine. At baseline and after 1, 2, 4 and 8 months, the following clinical parameters were recorded: plaque and gingivitis indices, probing depth, bleeding on probing and clinical attachment level. Microbiological samples were taken from different intra-oral niches (tongue, mucosa, saliva and pooled samples from single- and multi-rooted teeth). The samples were cultured on selective and non-selective media in order to evaluate the number of CFU/ml for the key-periodontopathogens. At baseline, an anonymous questionnaire was given to the patients to record the perception of each treatment (post operative pain, fever, swelling etc.). RESULTS: All 3 treatment strategies resulted in significant improvements for all clinical parameters, but the Fdis and FRp patients reacted always significantly more favourably than the control group, with an additional probing depth reduction of +/- 1.5 mm and an additional gain in attachment of +/- 2 mm (for pockets > or = 7 mm). Also from a microbiological point of view both the FRp and Fdis patients showed additional improvements when compared to the control group, as well in the reduction of spirochetes and motile organisms as in the number of CFU/ml of the key-pathogens, especially when the subgingival plaque samples were considered. The differences between FRp and Fdis patients were negligible. CONCLUSIONS: These findings suggest that the benefits of a "one-stage full-mouth disinfection" in the treatment of patients suffering from severe adult periodontitis probably results from the full-mouth scaling and root planing within 24 h rather than the beneficial effect of chlorhexidine. The raise in body temperature the second day after the full-mouth scaling and root planing seems to indicate a Shwartzman reaction.

Adult↗

PubMed2000

Renal antioxidant enzymes and fibrosis-related markers in the rat adriamycin model.

Excessive generation of reactive oxygen intermediates can induce changes in the cellular antioxidant defence system. In this study we examine the antioxidant enzyme status and the expression of fibrosis-related marker proteins in the Adriamycin model of chronic renal failure in the rat. Twenty weeks after Adriamycin treatment, rats have overt nephrotic syndrome and renal failure with development of tubulo-interstitial fibrosis and glomerulosclerosis. Lipids accumulate in blood and in both glomeruli and tubulo-interstitial tissue. Desmin and alpha-smooth muscle actin expression increases in glomeruli and in the tubulo-interstitial area. Renal cortex antioxidant enzyme activities are decreased 20 weeks after Adriamycin injection (to 41% for catalase, to 56% for total superoxide dismutase and to 69% for glutathione peroxidase). The mRNA levels of catalase, Cu/Zn-superoxide dismutase and glutathione peroxidase-1 evaluated by Northern blot are decreased by more than 50% for catalase, Cu/Zn-superoxide dismutase and glutathione peroxidase-1. We conclude that in the rat Adriamycin-induced model of chronic renal failure with fibrosis, the combination of decreased antioxidant enzyme status in renal cortex with high concentrations of lipids in blood and renal tissue facilitates oxidative damage. Development of fibrosis is paralleled by increased expression of desmin and alpha-smooth muscle actin.

Animals↗

PubMed2000

[Portal hypertension caused by intra-hepatic block during chronic lymphoid leukemia].

Portal hypertension in chronic lymphocytic leukemia is rare. A 66 year-old man was admitted for splenomegaly, thrombopenia and cholestasis. Endoscopy showed esophageal varices. The hepatic venous pressure gradient was 15 mmHg. The liver biopsy showed dense leukemia cells in sinusoidal and portal sites. After splenectomy, the hepatic venous pressure gradient normalized, but esophageal varices and cholestasis persisted. The authors discuss the mechanisms of portal hypertension in chronic lymphocytic leukemia. Previously reported cases are summarized.

Aged↗

PubMed1999

The effect of CO2 pneumoperitoneum on the growth of a solid colon carcinoma in rats.

BACKGROUND: In order to investigate the effect of carbon dioxide (CO(2)) pneumoperitoneum on solid colon carcinomas, we used a colon anastomosis tumor model in 30 male syngeneic WAG rats, which were divided, at random into three groups. METHODS: In all rats, 10(6) CC531 S colon carcinoma cells were injected as an enema into the colon. Subsequently, a transection and a reanastomosis of the colon descendens was performed via laparotomy. After 2 weeks, group 1 (n = 10) was anesthetized as an anesthesia control group. Group 2 (n = 10) had a laparotomy that was closed after 20 min. In group 3 (n = 10), a CO(2) pneumoperitoneum of </=6 mmHg was created and maintained during 20 min. After 2 weeks, all rats were killed, and total tumor weight and volume was measured. RESULTS: At necroscopy tumor growth was found in 16 rats (group 1: six; group 2: five; group 3: five). No difference in tumor growth (weight or volume) was found between the three groups. CONCLUSION: In our solid colon carcinoma model, CO(2) pneumoperitoneum did not enhance tumor growth.

Animals↗

PubMed1999

One stage full- versus partial-mouth disinfection in the treatment of chronic adult or generalized early-onset periodontitis. II. Long-term impact on microbial load.

BACKGROUND: Recent studies showed the clinical benefits of a one stage full-mouth disinfection, when compared to the worldwide standard treatment strategy of consecutive root planings per quadrant without proper disinfection of the remaining intraoral niches. The purpose of this study was to investigate the microbiological benefits of such a one stage full-mouth disinfection with special attention to all intraoral niches for periodontopathogens and to evaluate the perception by the patients of the new treatment strategy. METHODS: Sixteen patients with early-onset periodontitis and 24 patients with severe adult periodontitis were randomly assigned to test and control groups. The control group was scaled and root planed, per quadrant, at 2-week intervals and given oral hygiene instructions. The test group received the one stage full-mouth disinfection treatment. At baseline and after 1, 2, 4, and 8 months, microbiological samples were taken from all niches (tongue, mucosa, saliva, and pooled samples from single- and multi-rooted teeth). The samples were cultured on selective and non-selective media. Patient perception of the treatment was evaluated using a questionnaire. RESULTS: In comparison to the standard therapy, the one stage full-mouth disinfection resulted in significant additional microbial improvements. The test group showed larger reductions in the proportions of spirochetes and motile organisms in the subgingival flora, and more significant reductions in the density of key pathogens, with even the eradication of P. gingivalis. The beneficial effects in the other niches were primarily restricted to the number of colony-forming units/ml of black-pigmented bacteria, especially on the mucosa and in the saliva and to a lesser extent on the tongue. Both treatments were well tolerated by the patients and the overall severity rating for both therapies was comparable, although 4 quadrants were treated within 24 hours in the test group versus only 1 in the control group. The full-mouth disinfection approach resulted more frequently in a slight increase of body temperature, especially after the second day. CONCLUSIONS: These findings support the benefit of a one stage full-mouth disinfection in the treatment of patients with either chronic adult or early-onset periodontitis.

Adult↗

PubMed1999

In vitro volatile sulfur compound production of oral bacteria in different culture media.

OBJECTIVE: The purpose of this study was to detect the relative contribution of Porphyromonas gingivalis, Fusobacterium nucleatum, and Prevotella intermedia in the production of oral malodor. METHOD AND MATERIALS: The volatile sulfur compounds produced by these bacteria in vitro were measured semiquantitatively by a portable sulfide monitor. RESULTS: Samples from the tongue, tonsils, and pharynx showed a significantly higher production (550 ppb) of volatile sulfur compounds during the first 6 hours after anaerobic incubation in broths (brain-heart infusion, Columbia, and Trypticase Soy) than after incubation in agar media (300 ppb) (P < 0.001). After 24 hours, values in broths and agars leveled off at 350 ppb (P = 0.3) and remained constant during the next 6 days. Measurement of separate pure cultures showed that maximal volatile sulfur compound production was reached 6 hours after incubation (450 ppb for the 3 bacteria). Higher volatile sulfur compound values were measured in brain-heart infusion. When measurements of mixed cultures of the 3 pathogens were performed every 15 minutes, the maximal value was reached after only 30 minutes of incubation (nearly 500 ppb). CONCLUSION: The in vitro volatile sulfur compound production of oral samples is preferably measured in broths. Maximal sulfur production from mixed cultures is reached after 30 minutes of incubation. Samples should always be inoculated at the same dilution.

Culture Media↗