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Biomedical subjects

J H Meurman

Publications and source records attributed to J H Meurman.

At least 73 records · Page 4Linked to original sources

Effect of Lactobacillus rhamnosus strain GG (ATCC 53103) on the growth of Streptococcus sobrinus in vitro.

Lactobacillus GG, a recently characterized L. rhamnosus GG strain (ATCC 53103), has been shown to exert inhibitory activity against a variety of bacterial species, including streptococci. We isolated and studied the effect of the inhibitory substance of Lactobacillus GG on some oral streptococci. The inhibitory activity of the isolated substance was weak, but some growth inhibition was observed in Streptococcus sobrinus pretreated with the substance in comparison with untreated controls. Zones of growth inhibition on agar plates were apparent only at pH values below 5, indicating that the inhibitory activity was restricted to a low pH range. Growth curve experiments showed a statistically significant inhibition between series with and without the isolated substance (P < 0.05). The ultrastructure of S. sobrinus was not affected when treated with the inhibitory substance. The Lactobacillus GG itself did not ferment sucrose. The results offer interesting perspectives for future research focusing on the protective function of normal flora and in the attempt to replace harmful bacterial species in oral microflora with less harmful ones.

Antibiosis↗

Simultaneous detection of Actinobacillus actinomycetemcomitans and Porphyromonas gingivalis by a rapid PCR method.

The identification of periodontal pathogens by conventional methods is time-consuming and difficult. Therefore, a multiplex PCR method for simultaneous detection of Actinobacillus actinomycetemcomitans (A.a.) and Porphyromonas gingivalis (P.g.) was developed for rapid and easy determination of these risk-indicator bacteria in human periodontal disease. The PCR primers were designed to hybridize to various regions of 16S rRNA genes, and a hot-start technique was used to obtain maximum sensitivity and specificity. This method can detect both of these bacteria in subgingival plaque samples at concentrations as low as 5 to 50 cells per sample. The sensitivity, however, was even 10 times better when the bacteria were analyzed in a water suspension. Since the only step between sample collection and the actual analysis is a brief centrifugation of the patient sample, the detection can be readily carried out in four hours. The performance of the method was studied with 36 patient samples. The results showed that the PCR method detected A.a. (44% vs. 25%, respectively) and P.g. (56% vs. 42%, respectively) more often than the conventional culture in plaque samples. Thus, our multiplex PCR method is rapid and more effective than conventional protocols in detecting these periodontal pathogens.

Aggregatibacter actinomycetemcomitans↗

Oral and dental manifestations in gastroesophageal reflux disease.

One hundred seventeen patients with reflux disease were examined with respect to the severity of their disease and oral, dental, and salivary findings. Twenty-eight patients had dental erosion, whereas the remaining 89 patients did not. No mucosal changes could be observed to be linked with the reflux disease. In the mean, the patients with erosion were older (54 versus 49 years), and the mean duration of their reflux disease was longer in comparison to those without erosion (17 versus 11 years, respectively). The severity of the reflux disease was more marked among patients with erosion than in those without as assessed by esophagogastroduodenoscopy, the Maratka classification, histologic examination of gastric and esophageal biopsy specimens, and 24-hour esophageal pH monitoring. No statistically significant differences were observed between the groups in any salivary parameters studied, although the number of patients with low salivary-buffering capacity was higher among those with erosion than among those without. Patients taking beta-blocking agents or tranquilizers had more erosion than those who did not take these medications. The severity of the reflux disease was not associated with any subjective symptoms in the mouth or pharynx. The frequency of consumption of acidic drinks and foodstuffs as determined by a questionnaire did not differ between the patients with and without dental erosion. Thus severe reflux disease of long duration was found to be potentially detrimental to the teeth, whereas milder forms of the disease need not cause dental side effects.

Adrenergic beta-Antagonists↗

Gingival and dental status, salivary acidogenic bacteria, and yeast counts of patients with active or inactive Crohn's disease.

To investigate dental, gingival, and salivary aspects during an exacerbation of Crohn's disease, 53 patients with long-standing Crohn's disease were clinically, endoscopically, and radiologically examined. The patients were divided in two groups: 32 patients had active disease and 21 patients had inactive disease. Oral examination of the patients did not reveal any statistically significant differences in gingival or dental indexes between the groups, but patients with active disease tended to have higher scores of gingivitis than patients with inactive disease despite the fact that the patients with active disease were younger than those in remission. No differences between the groups were observed in salivary flow rate or buffering capacity. Lactobacilli and yeast counts of saliva tended to be higher among patients with active disease than with inactive disease, but the difference between the groups was significant only for high mutans streptococci counts.

Adult↗

Effect of anticancer drugs on patients with and without initially reduced saliva flow.

We reported earlier that despite the well-known cytolytic effect of anticancer drugs, mean stimulated salivary flow rates were not significantly affected during a 12-month follow-up of patients undergoing treatment for lymphomas (Laine et al. Oral Oncol, Eur J Cancer 1992, 28B, 125-128). Therefore, we set out to investigate in more detail the flow rates and composition of salivas in these patients, but now grouped according to their initial flow rate values, which had been assessed before the start of treatment. 49 patients of the original material (30 men and 19 women, mean age 49.9 years) were divided into hyposalivation and normal flow rate groups, according to their baseline values. Stimulated saliva flow > or = 0.8 ml/min was regarded as the limit for a normal flow rate. 11 patients were found to have reduced flow at baseline (hyposalivation group), while 38 patients had normal flow rate. Analysis of repeated saliva samples taken during the 12-month follow-up showed that flow rates remained significantly lower in the hyposalivation group compared with those of the other group (P < 0.001). Further, the concentrations of total protein, albumin, lysozyme, amylase, IgG, IgA and IgM were, and remained, all significantly higher in patients of the hyposalivation group. Counts for salivary mutans streptococci and yeasts were higher and remained significantly so among patients with hyposalivation than among those with normal flow rate while lactobacilli counts were higher in patients with normal initial flow rate.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

The effect of prebrushing mouthrinse solutions on the desorption of albumin from apatite.

This study evaluated the desorption of radiolabelled albumin from synthetic hydroxypatite by 4 commercial prebrushing solutions: Lysoplac (containing chlorhexidine), Plax (sodium benzoate), Acti-Brush (triclosan), and Sanogyl (sodium fluoride). In 3 min, Lysoplac and Plax were found to desorb about 90% of albumin while Acti-Brush and Sanogyl failed to desorb hardly any albumin in 15 min. The desorbing effectiveness of the test solutions was not due to their pH, because when buffer solution was being tested in different ionic strengths at pH range 6-8, it appeared to desorb less than 3% of adsorbed albumin, irrespective of the pH used. The results obtained cannot, however, be directly applied to the clinical situation where much more complex interactions occur than what were tested under the present in vitro conditions.

Adsorption↗

Mutans streptococci and lactobacilli in the elderly.

The prevalence of salivary mutans streptococci and lactobacilli, salivary flow rate, and the type of dentition were studied in connection with a medical survey of 76-, 81-, and 86-yr-old inhabitants of Helsinki living at home. High bacterial counts were associated with low salivary flow rates. High counts of mutans streptococci (> 10(6) CFU/ml) were found in 68% of wearers of full dentures, as compared with 53% of subjects having natural teeth. High counts of lactobacilli (< 10(6) CFU/ml) were found in 44% of subjects having removable partial dentures and in 39% of subjects having natural teeth. The bacterial counts correlated neither with medicines taken daily nor with diseases among this population.

Aged↗

Healing of rat mouth mucosa after irradiation with CO2, Nd:YAG, and CO2-Nd:YAG combination lasers.

The healing process of wounds made by a combination laser was studied in 90 rats. The laser system enabled both separate and combined use of CO2 and Nd:YAG laser irradiations. The laser wounds and the control excision wounds made by alligator forceps appeared on both sides of the tongue. Specimens from the wound sites were taken immediately, 6 h, and 1, 2, 4, 7, 11, 21, 28, and 42 days after surgery. The wound-healing process was studied by macroscopic evaluation before preparing the specimens for light microscopy. Some differences were noted in the wound-healing process among the three groups into which the experimental animals were divided. Tissue coagulation damage was most extensive in the Nd:YAG laser sites, where it was observed in its full extent 4 days after surgery. Epithelial cells were seen to begin to proliferate in all the wounds 6 h after surgery. Re-epithelialization was completed by between 7 (CO2) and 21 days (Nd:YAG) at all the wound sites. The inflammatory cell infiltration was more prominent in the Nd:YAG and the CO2-Nd:YAG combination laser wounds than in the CO2 and excision wounds during healing. Tissue regeneration occurred faster with less contraction in the combination CO2-Nd:YAG wounds than in Nd:YAG wounds. The best macroscopic healing result was seen in the CO2 wound sites. The combination laser was effective both at cutting and at coagulating tissue. Combining the CO2 and Nd:YAG laser irradiation into one beam resulted in a greater incision depth than what could have been expected from using the two lasers separately.

Aluminum Silicates↗

Salivary flow rate, buffering capacity, and yeast counts in 187 consecutive adult patients from Kuopio, Finland.

The aim of this study was to investigate salivary flow rate, buffering capacity, and yeast counts in all adult patients seeking dental treatment at the University Dental Clinic in Kuopio, Finland, during autumn 1992. Altogether, 187 consecutive patients over 20 yr old were included. Stimulated and unstimulated salivary flow rates were as follows: 1.8 +/- 0.9 ml/min; 0.6 +/- 0.4 ml/min in men, and 1.3 +/- 0.7 ml/min; 0.4 +/- 0.3 ml/min in women. A total of 103 patients used one or more systemic medications daily, mainly for cardiovascular disease (29.9%). The patients with medication had significantly lower flow rates than unmedicated subjects; in particular, in the older age group over 60 yr old. The medicated subjects also had significantly more often low buffering capacity values than the unmedicated ones (20% and 7%, respectively, with pH < 4 in the Dentobuff score). Positive yeast counts were observed in 66% of men and 55% of women, and more often in medicated than in unmedicated subjects (63% and 57%, respectively, NS). The results emphasize the need to take patients' sex and systemic medication into account in all salivary diagnoses.

Adult↗

Effect of fluoride varnish and solution on enamel erosion in vitro.

The effect of fluoride varnish and solution on initial enamel erosion was studied. Enamel specimens prepared from human third molars were treated for 24 h with Duraphat varnish (2.26% F) or for 48 h with NaF solution (1.2% F), washed, and immersed in cola beverage (pH 2.6) for up to 15 min. The surface microhardness was measured using a Vickers diamond in a Leitz indentation apparatus at base-line, after fluoride treatment, and after 1, 5, and 15 min exposure to acidic drink. The specimens were then prepared and studied using a JEOL JSM-35 scanning electron microscope. The results showed that both fluoride treatment caused an increase in enamel hardness values and subsequent inhibition of softening which was statistically highly significant. Scanning electron micrographs revealed the difficulty of removing Duraphat varnish from the enamel surface, and remnants of varnish were seen irrespective of vigorous sonication in acetone. However, in areas devoid of varnish, erosion was observed as mainly irregular lesions similar to those seen in the NaF solution treated and control specimens. The present study showed that treatment of enamel with topical fluoride prior to acidic challenge can inhibit initial erosion.

Adult↗

Effect of 1-week fasting on some blood values in man.

Fifty-eight voluntary and healthy subjects (mean age 42.3 +/- 11.2 years) participated in 7-day supervised fasting trial during which only fruit and berry juices, tea and water were consumed. Venous blood was drawn before and after 1-week fasting and 3 months after the termination of the trial. The subjects' body weight and blood pressure values were also recorded. The results showed a statistically significant decrease in blood thrombocyte counts after 1-week fasting (p < 0.05), while a significant increase was observed in serum beta-hydroxybutyrate and alanine aminotransferase activities (p < 0.001). All other blood values, including glucose and creatinine, remained stable throughout the trial.

Adult↗

Comparison of the clinical status of third molars in young men in 1949 and in 1990.

We investigated the clinical status of third molars in 876 Finnish conscripts aged 19.9 years (SD, 1.1 years) and compared the findings with data on male students of the same age from 40 years before. Significantly more partially erupted and fewer totally erupted lower third molars were found in the present study than 40 years earlier: 29% (95% confidence interval +/- 3%) versus 19% were partially erupted (p > 0.001), and 13% (confidence interval +/- 3%) versus 23% were totally erupted (p < 0.001). Fifty-eight percent of the lower third molars in the present study were clinically missing, whereas 13% (confidence interval +/- 2%) were totally erupted. The respective percentages in the upper jaw were 56% (confidence interval +/- 3%) versus 38% (confidence interval +/- 3%). Thirty-eight percent (confidence interval +/- 3%) of our subjects had one or two partially erupted third molars in the mandible and 10% (confidence interval +/- 2%) in the maxilla.

Adult↗

Oral findings in patients with active or inactive Crohn's disease.

The frequency and type of oral mucosal lesions, dental infections, and salivary constituents were evaluated in 53 patients with Crohn's disease, who were divided into inactive, mildly active, and severely active groups on the basis of clinical and endoscopic criteria. Buccal biopsies from nine patients with active disease showed morphologic changes that suggested Crohn's disease-related lesions. Panoramic radiographs revealed more infectious foci in the teeth of patients with active Crohn's disease than in patients with inactive disease. Salivary flow rate, buffering capacity, total protein, amylase, and IgA and IgG concentrations did not differ with respect to the activity of Crohn's disease. The observed mucosal inflammation in patients with active Crohn's disease, although high in frequency, was mild and did not need therapy, but the great number of dental infections in association with the activity of Crohn's disease should be taken into account in the treatment of these patients.

Adult↗

Lesions of the oral mucosa in lymphoma patients receiving cytostatic drugs.

The 1-year incidence of oral mucosal lesions during cytostatic therapy was investigated in 67 patients [34 men and 33 women (mean age 49 years)] out of 79 original patients, being treated for non-Hodgkin lymphoma or Hodgkin's disease. The incidence of lesions during examinations was 43.4%. Recurrent lesions were observed in 19.4% of cases. Mean leukocyte counts were statistically significantly lower (P < 0.01) during lesion periods than before cytostatic therapy in all lesion groups. Leukocytopenia was found in 85.4% of patients with hairy leukoplakia-like lesions (HLL), and in 81.8% of the patients with angular cheilitis. 5 out of 14 patients with oral ulcers (35.7%) had episodes of septicaemia. Mean thrombocyte counts of patients in various lesion groups were normal (< 140 x 10/1). However, low thrombocyte counts were more statistically significant (P < 0.05), when haemorrhages or HLL were present. Clinical candidiasis was diagnosed in 28.4% of patients during the treatment. However, cultivation revealed that 62.3% of salivary yeast cultures were positive. The study reported here shows a correlation between mucosal ulcers and septicemia, and between leukocytopenia, angular cheilitis and HLL. The disparity between clinically diagnosed candidiasis and the occurrence of salivary yeast counts suggests that antifungal drugs might be of prophylactic value during cytostatic therapy.

Adult↗

One-year trial of the effect of rinsing with an amine fluoride-stannous-fluoride-containing mouthwash on gingival index scores and salivary microbial counts in lymphoma patients receiving cytostatic drugs.

This double-blind study was undertaken to evaluate the effect of twice-daily use of a mouthwash containing 0.025% of fluoride as amine fluoride-stannous fluoride (AmF + SnF) or 0.05% of fluoride as sodium fluoride (NaF) on visible plaque index (VPI) and gingival bleeding index (GBI) and on some salivary micro-organisms in patients suffering from non-Hodgkin or Hodgkin lymphomas. 79 patients were allocated at random to the two mouthwash groups. Mouthwashing began at the start of cancer chemotherapy. Results relating to 45 patients who completed a 1-year rinsing protocol showed a significant decrease in VPI and GBI in the AmF + SnF group. An increase was found in the NaF group. Mean values for stimulated salivary secretion rates and buffering capacities mostly did not differ significantly from baseline values during the study. In both groups, mutans streptococci counts decreased significantly after the study began and remained low in the AmF + SnF group. No corresponding effect was seen in relation to lactobacilli and yeast counts. In the NaF group, lactobacilli counts increased significantly over a year. Significantly more patients reported adverse or unpleasant effects in the AmF + SnF group (52%) than in the NaF group (6%), although both solutions had the same colour and taste. However, all patients continued with rinsing.

Adult↗

Periodontopathic bacteria and salivary microbes before and after extraction of partly erupted third molars.

This study examines the effect of extraction of third molars on suspected periodontopathogenic microbes, salivary acidogenic bacteria, and yeasts. The subjects were 39 healthy conscripts aged 20.2 yr, with symptom-free, partly erupted mandibular third molars. Microbial samples were taken from the mandibular third molar pericoronal space and from the adjacent gingival pocket of the second molar. The samples were stained by Gram's and Giemsa's methods and studied under a light microscope. Stimulated saliva was collected for assessing mutans streptococci, lactobacilli, and yeast counts by chair-side kits. All partly erupted third molars were extracted from 20 test subjects; 19 control subjects were left untreated. Microbial samplings were repeated 2 and 5 months postoperatively. Results showed that at base line the total number of Gram-negative bacteria, Gram-negative rods, and spirochetes was significantly higher at the third molar than at the second molar sites. The extraction of the third molars caused a significant decrease in the percentage of these bacteria at the second molar sites. High counts of salivary mutans streptococci (CFU > or = 10(6)) and lactobacilli (CFU > or = 10(5)) were also significantly less frequent after the operations. Yeast counts were not affected by the extractions. Thus, partly erupted third molars may harbor a periodontally pathogenic microflora and increase the number of salivary acidogenic microbes.

Adult↗