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Biomedical subjects

R G Fischer

Publications and source records attributed to R G Fischer.

At least 19 recordsLinked to original sources
PubMed1995

Single daily dose of methimazole compared to every 8 hours propylthiouracil in the treatment of hyperthyroidism.

This study to compare single-dose and multiple-dose antithyroid therapy was prompted by a perceived lack of compliance in our University Medical Clinics by those patients using multidose regimens. Twenty-two hyperthyroid patients were randomly assigned to two therapy groups. Twelve received methimazole (Tapazole) 30 mg once daily in the morning; 10 received propylthiouracil 100 mg every 8 hours. Patients were seen every 4 weeks for 3 months and assessed clinically, as well as having the appropriate thyroid tests done. Univariate analysis revealed no difference in the two groups at baseline. Posttreatment assessment revealed the once-a-day methimazole therapy to be just as effective as propylthiouracil in improving thyroid indices and clinical markers. Compliance with methimazole was 83.3% compared to 53.3% with propylthiouracil. In conclusion, once-a-day methimazole was just as effective as propylthiouracil every 8 hours in this population. Compliance was also improved with the once-a-day therapy.

Drug Administration Schedule↗
PubMed1994

Oral microflora of the ferret at the gingival sulcus and mucosa membrane in relation to ligature-induced periodontitis.

The aim of this study was to describe, in the domestic ferret, the composition of the normal gingival sulcus and the near related mucosa microflora and the shift in the composition during an acute periodontal breakdown induced by the placement of ligatures. Five animals were used. At the start of the experiment (day 0) and before the placement of the ligatures, 2 microbiological samples were obtained from the gingival sulcus and the related mucosa at the mid-buccal surface of the right upper P4. The same sites were sampled on the left side, serving as control sites. On day 28, new microbiological samples were taken from the same 4 sites. The samples were analyzed with darkfield microscopy and with viable counts. In the darkfield analysis, on day 0, the predominant bacterial morphotype was cocci, ranging from 88-92%. The viable counts showed that nearly 100% of the total cultivable flora was composed of facultative anaerobic gram-negative and gram-positive rods. Pasteurella spp., Corynebacterium spp. and Rothia spp. were the major components of these bacterial groups. No anaerobic bacteria were detected. On day 28, cocci decreased to approximately 75% in the experimental gingival sulcus sample, and filaments and rods increased significantly. Spirochetes remained largely unchanged during the experiment. The composition of the experimental site samples changed. There was a decrease in the mean numbers of facultative anaerobic gram-positive rods, and approximately one third of the microflora comprised anaerobic gram-negative rods, mainly Porphyromonas gingivalis and Fusobacterium spp. Although the composition of the microflora of the ferret presented few similarities to that described in dogs and monkeys, the anaerobic portion of the gingival sulcus and oral mucosa microflora related to ligature-induced periodontitis presented microorganisms observed in experimental periodontitis both in dogs and monkeys as well as in human periodontal diseases.

Animals↗
PubMed1994

Clinical and histological evaluation of ligature-induced periodontitis in the domestic ferret.

The aim of this study was to evaluate the clinical and histological characteristics of ligature induced periodontitis in 12 domestic ferrets. On day 0, silk ligatures were placed at the gingival margin level of selected experimental teeth. The contralateral teeth served as control teeth. On day 14, 4 animals and on day 28, 8 animals were sacrificed. Clinical measurements including gingival index (GI), probing pocket depth (PPD) and probing attachment level (PAL) were taken in 5 animals on days 0, 14 and 28. Histological sections were prepared for light microscopy. The histometric measurements performed were (1) the distance between the cemento-enamel junction (CEJ) and the alveolar bone crest and (2) the distance between CEJ and connective tissue attachment level. The number of sections with root resorption areas was also observed. Cell counts were taken in 4 different areas. Clinical results showed, on days 14 and 28, a significant increase of the mean values of PPD and PAL at the experimental teeth when compared to the control teeth. The histometric results showed a significant loss of connective tissue attachment and bone loss in the experimental teeth on day 14. On day 28, the results were similar, although more sections with root resorption areas were observed in the experimental teeth. The predominant inflammatory cell in all the 4 experimental areas analyzed was polymorphonuclears (PMN), and they were mainly increased in areas closely related to the junctional epithelium. The results indicate that the domestic ferret may be used as an experimental animal in the ligature-induced periodontitis model.

Alveolar Bone Loss↗
PubMed1994

Clinical and histological evaluation of ligature-induced periodontal breakdown in domestic ferrets immunosuppressed by Cyclosporin-A.

The aim of this study was to evaluate, clinically and histologically, the effect of Cyclosporin-A (CyA) on the progression of the periodontal breakdown in the domestic ferret, using the ligature induced periodontitis model. At the start of the experiment (day 0), silk ligatures were placed at the gingival margin level of experimental teeth. The contralateral teeth served as non-ligated control teeth. Clinical measurements included gingival index, probing pocket depth (PPD), probing attachment level (PAL) and gingival overgrowth (GO) and they were performed on days 0, 14 and 28. Cyclosporin-A, 10 mg/kg/d, was given subcutaneously from day 0 to 21, while in the last week there was a reduction of this dose to 5 mg/kg/d. Blood samples were taken on days 0, 14 and 28. On day 28 the animals were sacrificed. Histological sections were prepared for light microscopy. The histometric measurements performed were: (1) the distance between cemento-enamel junction and the alveolar bone crest and (2) loss of connective tissue attachment. The number of sections with root resorption areas was observed. Cell counts were taken in 4 different areas. The results showed, on days 14 and 28, a significant increase of the mean values of PPD and PAL at experimental teeth as compared to the control teeth. GO was present on experimental teeth on days 14 and 28. On day 28, the control teeth presented a very small increase in GO, mainly at the buccal sites of P4 and M1. The histometric results showed a significant loss of attachment and bone resorption in the experimental teeth. Root resorption was found in experimental teeth only. The predominant inflammatory cell in the 4 experimental areas was polymorphonuclears.(ABSTRACT TRUNCATED AT 250 WORDS)

Alveolar Bone Loss↗
PubMed1993

Normal histologic features of domestic ferret periodontium.

The normal histologic features of the periodontal tissues in 17 domestic ferrets (10 male and 7 female) are described. The following teeth were histologically evaluated: canines, the maxillary third premolar (P3), the mandibular fourth premolar (P4), the carnassial teeth (P4 in the maxilla and the first molar, M1, in the mandible) and the next molar after the carnassials (M1 in the maxilla and M2 in the mandible). After histologic preparation for light microscopy, the sections were analyzed at magnifications of x 20 and x 100. The histometric measurements performed were 1) distance between the cementoenamel junction (CEJ) and the alveolar bone crest, 2) distance between CEJ and the most coronal connective tissue, 3) root length, 4) width of the periodontal ligament at three different locations along the root surface, and 5) cementum layer thickness at the most apical portion of the root. The number of sections exhibiting root resorption was counted. The results gave the normal values of some common periodontal variables and suggested a possible future use of the domestic ferret as an alternative experimental animal in periodontology.

Animals↗
PubMed1992

Prevalence and distribution of cervical dentine hypersensitivity in a population in Rio de Janeiro, Brazil.

The prevalence, distribution and possible causal factors of cervical dentine hypersensitivity were studied in a population from a Marine Dental Clinic in the city of Rio de Janeiro, Brazil. A total of 635 patients were examined for the presence of cervical dentine hypersensitivity by means of a questionnaire and intraoral tests (air and probe stimuli). There were 157 patients (25%) reporting to have hypersensitive teeth, but only 108 patients (17%) were diagnosed as having cervical dentine hypersensitivity. The prevalence of hypersensitivity was higher among females than males, but this difference was not statistically significant. Most females with hypersensitivity were aged 20-49 and most males were aged 40-59. Incisors and premolars had the highest prevalence of dentine hypersensitivity to air and probe stimuli, while molars had the lowest. The presence and history of dentine hypersensitivity were positively correlated with previous exposure to periodontal treatment. Only a few of the patients who claimed to have dentine hypersensitivity had tried treatment with desensitizing toothpastes or sought professional help.

Adolescent↗
PubMed1991

Clinical evaluation of pulp and dentine sensitivity after supragingival and subgingival scaling.

The exposure of dentinal tubules by the removal of root cementum on scaling procedures has been proposed to be a source of pulp injury and to cause dentine hypersensitivity. The aim of this study was to evaluate the sensitivity of the pulp and dentine after supragingival and subgingival scaling. Eleven patients with periodontally diseased mandibular incisors were selected. The subjects were divided into two groups according to marginal bone loss. The pulp sensitivity was evaluated by an electric pulp test. Dentine sensitivity was evaluated with two forms of controlled stimulations (probe and air-jet) and with a questionnaire. No changes in pulp sensitivity were found after scaling, but a clinically significant increase in dentine sensitivity to probe and/or air stimuli was observed in 6 patients. Five of these were also sensitive to daily life stimuli. A natural mechanism of desensitization seemed to have occurred two weeks after subgingival debridement. This study showed that supragingival and subgingival scaling might cause a more or less transient occurrence of dentine hypersensitivity.

Adult↗
PubMed1985

Severe contact dermatitis due to nitroglycerin patches.

As shown by the two cases described, contact dermatitis due to nitroglycerin patches can be severe. Patients should be counseled to rotate application sites daily and report to the physician any signs of skin irritation.

Administration, Topical↗
PubMed1980

Compliance-oriented prescribing: simplifying drug regimens.

Simplifying drug regimens is one method of improving patient compliance. Medications originally administered several times a day are now reported to maintain 24-hour effectiveness on once-daily administration. In many cases this technique of administration results in the use of less expensive medication, an improvement in compliance, and even decreased side effects. All patients may not be controlled or tolerate increased intervals between drug doses. Interpatient variation dictates that physicians closely monitor their patients when prescribing new or unapproved regimens of drug therapy.

Anti-Infective Agents↗