Overdentures--the past reprieve.
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Dental Abutments↗
Biomedical subjects
R Willen
Publications and source records attributed to R Willen.
Overdentures--a better alternative to complete extractions.
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Denture Design↗
Bioptic techniques in flexible endoscopy. An experimental study in the pig.
Low success rates in biopsies of submucosal gastric lesions have been reported. We undertook an experimental study in the pig of three different and commonly used bioptic techniques to test their ability to provide submucosal material using spiked as well as nonspiked biopsy forceps. The best results were obtained using the Crosta technique where the overlying mucosa is excised using a diathermy snare and biopsies are taken from the bared underlying tissue. The hole-in-hole technique of Seifert and the ethanol injection technique of Asaki were inferior as to bioptic depth but not in size of the biopsies. Biopsy forceps with a central spike were slightly superior to those without.
Animals↗
Helicobacter pylori in endoscopy patients in Zimbabwe: value of enzyme-linked immunosorbent assay and a rapid urease test.
Biopsy and serum specimens were obtained from 95 patients undergoing endoscopy at the University of Zimbabwe Medical School. Common presenting features were epigastric pain, bleeding and dyspepsia. Ulcers were detected in 16 patients (17%), and were more common in men (24%) than in women (7%). Histological examination of biopsies showed that all 95 patients had spiral-shaped organisms that were indistinguishable microscopically from Helicobacter pylori, though the numbers of organisms varied considerably. There was evidence that the degree of inflammation in the mucosa was related to the numbers of H. pylori-like organisms (HPLO) present. Fifty-one biopsy specimens (55%) gave a positive rapid urease test (RUT), with colour change occurring within 4 h. In all but one case, the gastric mucosa from these patients contained moderate to numerous HPLO. We defined the 'gold standard' of H. pylori-associated gastritis as the presence of both moderate to numerous HPLO and moderate to severe inflammation in the gastric mucosa. Using these criteria, RUT had a sensitivity of 67% and a specificity of 68%. Sera from 92 patients were tested for immunoglobulin G antibodies reactive with a glycine-extract antigen of H. pylori, using an enzyme-linked immunosorbent assay (ELISA). Sera giving an indeterminate reaction in the ELISA were also tested by Western blotting. In all, 36 sera (39%) gave a positive ELISA or Western blot reaction. There was poor correlation between serology and RUT results, with only 57% of biopsy specimens from seropositive patients giving a positive RUT, compared with 45% from seronegative patients. Positive serology was found in only 35 patients (61%) with histological evidence of H. pylori-associated gastritis, and the specificity of the test was only 54%. When used in combination with the RUT result, however, 79% of patients with a positive RUT and positive serology had histological evidence of H. pylori-associated gastritis. There was a general trend for increased seroprevalence in patients with mild to moderate atypia. These findings indicate that serology, using an antigen derived from the type strain of H. pylori, is unreliable in detecting H. pylori infection in Zimbabwe. Current studies are aimed at characterizing antigens from organisms isolated from Zimbabwean patients.
Adolescent↗
Disaccordance between estimation of endometrial thickness as measured by transvaginal ultrasound compared with hysteroscopy and directed biopsy in breast cancer patients treated with tamoxifen.
OBJECTIVE: To estimate endometrial thickness by transvaginal ultrasound technique (TVU) in patients treated with tamoxifen; and to compare the results with hysteroscopy and directed biopsy, and to relate the findings to curettage material. METHODS: Fifty-four women, over 50 years of age at the time of their primary breast cancer operation and scheduled for adjuvant treatment of tamoxifen, were investigated. If the endometrium measured 8 mm or more (35 patients) hysteroscopy and directed biopsy was performed. RESULTS: In the 35 patients, hysteroscopy and curretage revealed polyps in 18 cases (51.4%), proliferation in 1 case (2.9%) and atrophy in 16 cases (45.7%). In 54.3% (19 cases) of the patients the histopathological finding was a polyp or benign proliferation of the endometrium in agreement with the thickened endometrium seen with TVU. In the remaining 45.7% (16 cases) of the patients a thickened endometrium by transvaginal ultrasound was false positive as the hysteroscopic and subsequent histopathological diagnosis only showed atrofia of the uterine endometrium. CONCLUSIONS: In almost half of the patients the TVU gave a misleading picture concerning the condition of the endometrium. Changes in the myometrium and related connective tissue could be misinterpreted by the ultrasound technique as changes in the endometrium. These results may confirm the theory that stimulation and changes by antiestrogenic treatment of the uterine tissue is not only restricted to the endometrium. In patients with thickened endometrium measured by TVU, a dilatation and curettage is not sufficient, as TVU has not the ability to differentiate between endometrial polyps and myometrial changes. A hysteroscopy and directed biopsy could therefore be performed.
Adult↗
Spontaneous endometrial hyperplasia. The prognostic significance of steroid receptor concentration. A two year follow-up of patients treated with abrasio only.
The steroid receptor concentrations were measured in 63 patients. The patients were part of a prospective randomized study and were treated with abrasio only. With respect to Cystic Glandular Hyperplasia (43 patients) 16 out of 25 with PgR values less than 10,000 (fmol/mg DNA) were normalized compared to only 4/14 with higher PgR conc (p = 0.03). No limit could be identified regarding patients with Adenomatous Hyperplasia and Atypical Hyperplasia (29 patients). Consequently patients with CGH and a high PgR concentration are recommended for high dose gestagen therapy.
DNA↗
Circadian variations in cell cycle phase distribution in a squamous cell carcinoma xenograft; effects of cisplatin and fluorouracil treatment.
Tumor tissue sampled at different points during a 24 hour period (08-08) from a xenografted squamous cell carcinoma of the head and neck was analyzed with flow cytometry. Statistically significant variations were found in the mean fraction of cells in the G1, S and G2 phases, the most pronounced variation occurring at 14 and 02 h. Histopathological examination showed no consistent circadian fluctuations in the fraction of cells in mitosis. Treatment with NaCl, cisplatin and fluorouracil was given at the time of most pronounced variation (i.e., 14 and 02 h). Toxicity was low. All animals in all groups survived treatment. All treated animals lost weight, but the initial weight loss was slightly greater and recovery delayed in the groups given cisplatin and fluorouracil at night. Tumor growth inhibition, as defined by the area under the growth curve, did not differ significantly between 14 and 02 h.
Animals↗
Flow cytometrical considerations. The results of three different ways of nuclear preparation and two ways of calculating upon DNA index, number of populations and S-phase rate in endometrial tissue.
Histopathologically normal endometrial tissues were used to compare the preparation methods of Tribukait, Thornthwaite and Vindelöv. Three hundred and forty-one preparations were analyzed giving as a result significant differences regarding the DNA-indices, number of DNA-populations and percentage of cells in S-phase fraction. We also compared a manual way of calculation to a semi-automatic method (RFIT). No difference was found between the manual way and RFIT provided that the same internal standard was used. However, the two different internal standards gave different results within the same method of preparation.
Cell Nucleus↗