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Biomedical subjects

E Peters

Publications and source records attributed to E Peters.

At least 55 records · Page 3Linked to original sources
PubMed1998

[Fundamentals of hygiene to be used for stallions in an instrumental artificial insemination].

Equine artificial insemination (AI) meanwhile has been widely established in the warm blood horse industry. Because of its importance consistent hygienic aspects and their significance for the use of stallions as semen donors in AI-programs are presented and clarified. Incidence as well as importance of equine venereal infectious diseases are considered. Data of physiological bacterial genital flora and treatment principles of therapeutic control of venereal infectious bacterial agents as well as a model of control of Equine Viral Arteritis are given. A prophylactic hygiene program for donor stallions in routine AI including special microbiological monitoring is presented.

Animals↗
PubMed1997

Longitudinal radiographic assessment of dense bone islands of the jaws.

OBJECTIVES: This study assessed dense bone island (DBI) inception and growth in jaws. STUDY DESIGN: A population of 2991 patients (age range 5 to 35 years) was studied with at least two panoramic radiographs taken 1 to 10 years apart for each patient. Lesions were digitized and measured with computer measuring software. The size of the earliest DBI was compared with subsequent DBI measurements after the latter measurement was normalized with reference to the size of the nearest tooth. RESULTS: Sixty-nine patients with DBIs were identified. A total of 3.1% of the patients with DBI were found in the 5- to 10-year age range, with the first patient in the DBI group found at 9.4 years. A significantly higher proportion (p = 0.002) of the unaffected patients (26%) was found in the same 5-to 10-year age range. The proportions of patients in the DBI and unaffected groups in older age ranges were similar. Assessment of DBI size changes showed that 43% of the 53 DBIs detected between 9.4 and 19 years enlarged (mean change, 212%), and 17% diminished (mean change, 49%). In comparison, 29.4% of 17 DBIs detected between 20 and 35 years enlarged (mean change, 153%), and 5.9% diminished (mean change, 60%). CONCLUSION: Our results indicate that DBIs are labile lesions, develop during early adolescence, and retain a potential for enlargement, or to a lesser extent shrinkage, into adulthood.

Adolescent↗
PubMed1997

Oral mucosal melanomas: the WESTOP Banff workshop proceedings. Western Society of Teachers of Oral Pathology.

A workshop to discuss primary oral melanomas was convened at the annual Western Society of Teachers of Oral Pathology meeting in Bannf, Alberta, Canada. Fifty oral melanomas, identified from the files of the participants, were reviewed in order to better understand the clinical features, histologic spectrum, and natural history of these perplexing lesions. Results confirmed that oral melanomas occur in adults almost three times more frequently in men than women and have a decided predilection for the palate and gingiva. Some lesions exhibit a clinically detectable and prolonged in situ growth phase, whereas others seem to lack this property and exhibit only or predominantly invasive characteristics. Recurrences, metastases, and death from tumor were characteristic of the follow-up of a limited number of patients. Until definitive prospective data are collected that elucidate natural history, oral mucosal melanomas should be tracked separately from cutaneous lesions. All oral pigmented lesions that are not clinically diagnostic should be biopsied. Lesions with equivocal histopathologic features might be referred to as "atypical melanocytic proliferation" and should be excised. Recognition of lesions in an early in situ phase and aggressive treatment should have a favorable effect on prognosis. To enhance future or prospective study of these rare neoplasms, guidelines for reporting oral melanomas are suggested.

Adult↗
PubMed1997

Induction chemotherapy with cisplatin, fluorouracil, and high-dose leucovorin for squamous cell carcinoma of the head and neck: long-term results.

PURPOSE: A phase II trial of cisplatin, fluorouracil, and leucovorin (PFL) induction chemotherapy in patients with locally advanced squamous cell carcinomas of the head and neck region (HNCA). PATIENTS AND METHODS: One hundred two patients (stage III/IV, previously untreated) were treated with induction PFL. Patients with resectable primary tumor site lesions and clinical complete response (CR) were offered radiotherapy (RT) without surgery to the primary tumor site. Response, toxicity, local-regional therapy, survival, and preservation of the primary tumor site were assessed. RESULTS: Among 279 courses, the overall response rate was 81%. Nineteen (19%) failed to respond, including three who died during therapy. Sixty-seven (69%) of 97 with assessable primary lesions had a clinical CR at the primary tumor site. Pathologic CR was recorded in 46 of 55 (84%) clinical CR patients who had biopsies performed on the primary tumor site. Toxicities resulted in unexpected hospitalizations in 19% of cases. After definitive local-regional therapy, 84 (82%) were disease-free including 71 (69%) with preserved primary tumor site anatomy. With a median follow-up time of 63 months, the cause-specific, overall (OS), and failure-free survival (FFS) rates at 5 years are 58%, 52%, and 51%. Local failure occurred in 29 of 102 (29%) and the local control rate at 5 years was 68%. CONCLUSION: PFL has significant activity with acceptable toxicity in patients with advanced disease who have a good performance status. Preservation of the primary tumor site could be achieved without apparent loss of local control or survival. Management of neck disease by surgery or RT must be individualized and separate from management of primary tumor. Survival compares favorably with similar trials of induction chemotherapy or chemoradiotherapy.

Adolescent↗
PubMed1996

Salivary gland duct involvement in oral epithelial dysplasia and squamous cell carcinoma.

The clinical implications and prognostic significance of oral dysplastic or cancerous epithelium involving salivary gland ducts have not been previously investigated. Screened routine tissue sections of 1216 cases of oral epithelial dysplasias and squamous cell carcinomas revealed 26 examples (2.14%) that exhibited unequivocal ductal involvement. Ductal involvement was more likely to occur in floor of mouth lesions and in lesions exhibiting severe dysplasia or carcinoma in situ. Clinical follow-up on 23 cases showed that the recurrence rate of the preinvasive lesions that exhibited ductal involvement was equal to that of the squamous cell carcinomas. The depth of ductal dysplasia did not correlate with recurrence rate. These results suggest that the involvement of salivary gland ducts by oral epithelial dysplasias and carcinomas in situ is an uncommon but significant finding. Surgical stripping or ablation of such lesions should extend at least 3 mm below the surface to ensure eradication of these reservoirs of dysplastic cells.

Aged↗
PubMed1996

alpha-Lactalbumin-enriched low-protein infant formulas: a comparison to breast milk feeding.

Tryptophan (TRP) is the limiting amino acid in low-protein infant formulas. This is mainly due to lower alpha-lactalbumin (alpha LA) content in cow's milk whey as compared with human milk protein. To study the effect of alpha LA-enrichment on the TRP supply, cross-over studies were carried out in 20 healthy infants up to 3 months of age. In this study, two protein-reduced (1.3%) infant formulas (moderate TRP content of 1.88% and higher TRP content of 2.10%) were alternately fed over a 2 week period in two groups of infants. Serum TRP levels of the formula-fed infants with the higher TRP content did not differ significantly from an exclusively breastfed control group of 11 infants (10.5 +/- 4.8 versus 10.9 +/- 4.7 mg l-1, p = 0.841), whereas levels of the formula-fed infants with the moderate TRP content were significantly lower (7.4 +/- 3.9, p = 0.038). The supplementation of alpha LA resulting in a higher TRP supply to low-protein diets is a further step towards the production of infant formulas more closely adapted to human breast milk.

Amino Acids↗
PubMed1996

Insulin-like growth factor I and insulin down-regulate growth hormone (GH) receptors in rat osteoblasts: evidence for a peripheral feedback loop regulating GH action.

The anabolic actions of GH are mediated by the production of insulin-like growth factor I (IGF-I) from the liver and by local production of IGF-I in extrahepatic tissues. Insulin facilitates the hepatic production of IGF-I by up-regulating GH receptors (GHRs) in the liver and augmenting the IGF-I response to GH. Although GHRs have also been identified in extrahepatic tissues that produce IGF-I, the possibility that IGF-I and insulin might partake in GHR regulation, thereby modulating the effects of GH locally has not received detailed study. The aim of this study was to investigate whether IGF-I and insulin are involved in the local regulation of GHRs, using osteoblasts as a model of GH-responsive extrahepatic tissues. We have used UMR106.06, a well differentiated rat osteoblast-like cell line that expresses GHRs and exhibits a mitogenic response to GH. IGF-I and insulin (0-10 nM) increased cell number and reduced [125I]GH binding in a concentration-dependent manner, with ED50 values of 0.8 and 0.3 nM, respectively. Although IGF-I increased cell number maximally by 36.9 +/- 1.2% (mean +/- SE) above the control value and insulin by 104.8 +/- 5.7% (P < 0.001), they decreased GH binding to 47.0 +/- 9.3% (P < 0.01) and 29.8 +/- 8.7% of the control value (P < 0.001), respectively. Scatchard analysis revealed that the down-regulation of GH binding was attributed to reduced receptor numbers and not binding affinity. The effects of IGF-I and insulin at submaximal concentrations were additive, although the combined effects did not exceed the maximal effect of either growth factor alone. Addition of an anti-IGF-I receptor antibody (alpha IR3) reversed the inhibition of GH binding induced by IGF-I, but not that caused by insulin; similarly, an antiinsulin receptor antibody (29B4) attenuated the inhibitory effect of insulin only. Addition of alpha IR3 alone or an ant-IGF-I antibody (Sm1.2) decreased cell number and increased GH binding in a concentration-dependent mode. GH at 1.5 nM significant increased cell number by 19.3 +/- 2.4% above the control level (P < 0.01), an increase that was reversed by alpha IR3. GH increased GH binding by 32.4 +/- 7.2% (P < 0.05) in cells treated with alpha IR3 to remove the secondary effect of IGF-I. In summary, IGF-I and insulin acted via specific receptors to stimulate cell proliferation and down-regulate GHRs in osteoblasts. GH stimulated cell proliferation, an action mediated by local production of IGF-I, and GH enhanced its own binding. The collective data suggest the presence of a peripheral negative feedback loop that allows IGF-I to limit locally the response of extrahepatic tissues to circulating GH.

Analysis of Variance↗
PubMed1996

Dental unit water contamination.

Bacteria-laden biofilms located on the lumen surface of dental unit water lines have resulted in the persistent and widespread microbial contamination of dental unit water supplies. These biofilms are resistant to chemical disinfection. As such, they act as reservoirs that facilitate the continuous re-contamination of dental unit water. The microbial populations of the biofilms found in dental unit water lines include opportunistic pathogens of unknown significance. Strategies to control the contamination are discussed.

Bacteria↗
PubMed1995

Polyadenylylation helps regulate mRNA decay in Escherichia coli.

As part of our genetic analysis of mRNA decay in Escherichia coli K-12, we examined the effect of the pcnB gene [encoding poly(A) polymerase I] on message stability. Eliminating poly(A) polymerase I (delta pcnB) dramatically stabilized the lpp, ompA, and trxA transcripts. The half-lives of individual mRNAs were increased in both a delta pcnB single mutant and a delta pcnB pnp-7 rnb-500 rne-1 multiple mutant. We also found mRNA decay intermediates in delta pcnB mutants that were not detected in control strains. By end-labeling total E. coli RNA with [32P]pCp and T4 RNA ligase and then digesting the RNA with RNase A and T1, we showed that many RNAs in a wild-type strain contained poly(A) tails ranging from 10 nt to > 50 nt long. When polynucleotide phosphorylase, RNase II, and RNase E were absent, the length (> 100 nt) and number (10- to 20-fold) of the poly(A) tails increased. After transcription initiation was stopped with rifampicin, polyadenylylation apparently continued. Deleting the structural gene for poly(A) polymerase I (pcnB) reduced the amount of 3'-terminal poly(A) sequences by > 90%. We propose a model for the role of polyadenylylation in mRNA decay.

Blotting, Northern↗
PubMed1995

Multicenter evaluation of arbitrarily primed PCR for typing of Staphylococcus aureus strains.

Fifty-nine isolates of Staphylococcus aureus and a single strain of Staphylococcus intermedius were typed by arbitrarily primed PCR (AP-PCR). To study reproducibility and discriminatory abilities, AP-PCR was carried out in seven laboratories with a standardized amplification protocol, template DNA isolated in a single institution, and a common set of three primers with different resolving powers. The 60 strains could be divided into 16 to 30 different genetic types, depending on the laboratory. This difference in resolution was due to differences in technical procedures (as shown by the deliberate introduction of experimental variables) and/or the interpretation of the DNA fingerprints. However, this did not hamper the epidemiologically correct clustering of related strains. The average number of different genotypes identified exceeded those of the more traditional typing strategies (F. C. Tenover, R. Arbeit, G. Archer, J. Biddle, S. Byrne, R. Goering, G. Hancock, G. A. Hebert, B. Hill, R. Hollis, W. R. Jarvis, B. Kreiswirth, W. Eisner, J. Maslow, L. K. McDougal, J. M. Miller, M. Mulligan, and M. A. Pfaller, J. Clin. Microbiol. 32:407-415, 1994). Comparison of AP-PCR with pulsed-field gel electrophoresis (PFGE) indicated the existence of strains with constant PFGE types but variable AP-PCR types. The reverse (constant AP-PCR and variable PFGE patterns) was also observed. This indicates additional resolution for combined analyses. It is concluded that AP-PCR is well suited for genetic analysis and monitoring of nosocomial spreading of staphylococci. The interlaboratory reproducibility of DNA-banding patterns and the intralaboratory standardization need improvement.

Bacterial Typing Techniques↗
PubMed1995

Measurement of growth hormone-binding protein in the rat by a ligand immunofunctional assay.

We have developed a ligand immunofunctional assay (LIFA) for quantifying the circulating functional GH-binding protein (GHBP) in the rat. This two-site solid-phase assay uses a capture monoclonal antibody (4.3) specific to the hydrophilic C-terminal segment of rat GHBP (rGHBP), saturation of binding with human GH, and a detection system of rabbit antihuman GH polyclonal antibody and peroxidase-conjugated antirabbit immunoglobulin G antibody. Results were compared with Scatchard estimates derived by immuno-precipitation with monoclonal antibody 4.3. This assay was used to determine the GHBP levels in male and female rats and to investigate the diurnal properties and dynamics of GH and GHBP interaction in 15-min blood sampling over a 6-h period. The dynamic range of the rLIFA was 0.15-20.0 nM recombinant rGHBP, with intraassay and interassay coefficients of variation of 10.5% (n = 20) and 12.9% (n = 12), respectively. Serum GHBP levels determined by the rLIFA and those derived from Scatchard estimates were strongly correlated (n = 8; beta = 0.55; r2 = 0.89; P = 0.0005). Male rats had lower GHBP levels (6.5 +/- 0.7 nM; mean +/- SE; n = 14) than female rats (35.4 +/- 2.7 nM; n = 15; P = 0.0001). In the diurnal study, male rats had higher GH peaks (312.5 +/- 121.6 ng/ml; n = 7) than female rats (96.5 +/- 15.4 ng/ml; n = 9; P < 0.0001). In contrast to the pulsatile secretion of GH, GHBP levels in both sexes remained stable and showed no relationship to secretory pulses of GH. However, the GH bursts significantly altered the distribution of the GH-GHBP complex in male rats. By saturation and mass analysis, the greater GH pulsatile secretion in male rats resulted in occupancy of GHBP from less than 5% at nadir to about 80% at secretory peaks, in contrast to the less than 5-15% range of GHBP occupancy in female rats. In male rats, greater than 80% of GH at secretory peaks existed in the free form, whereas in female rats, 16-23% of GH existed in the free form during pulsatile secretion. In summary, the rLIFA shows good correlation to Scatchard analysis using an identical antibody. We conclude that this assay provides a rapid, sensitive, and accurate measurement of the circulating functional GHBP in the rat, and that it facilitates the study of GH and GHBP dynamics under a range of physiological conditions.

Animals↗
PubMed1995

Detection of premalignant oral lesions: a 10 year retrospective study in Alberta.

A comprehensive review of all oral premalignant lesions and squamous cell carcinomas (SCC) diagnosed and biopsied by the oral pathology diagnostic service at the University of Alberta over two sequential five-year periods (1984-1988 and 1989-1993) was undertaken. There was a disproportionate increase in the number of premalignant biopsies conducted in 1989-93 relative to the number of SCC biopsies, suggesting an improvement in the detection of oral pre-malignancy by dentists.

Alberta↗
PubMed1993

Assessment of the need for treatment of postendodontic asymptomatic periapical radiolucencies in bone marrow transplant recipients.

Oral screening and treatment of existing oral disease before bone marrow transplantation have been reported to decrease the incidence of infectious complications during bone marrow transplantation. Information about the adverse sequelae of specific preexisting oral diseases during bone marrow transplantation is lacking. The presence of postendodontic periapical radiolucencies may suggest recurrent or latent infection. The purpose of this study was to compare the effect of endodontic treatment with nontreatment of asymptomatic postendodontic periapical radiolucencies on the frequency of infectious oral complications during bone marrow transplantation. The records of 276 patients undergoing bone marrow transplantation examined between July 1988 and June 1991 were reviewed retrospectively. Twenty-three postendodontic periapical radiolucencies were identified in 8 women and 15 men. The mean age of patients was 41 years (range, 25 to 58 years). Fourteen of the lesions were untreated, and nine were treated before bone marrow transplantation. When outcomes of transplant complications were compared, neither increased systemic infection as measured by neutropenic days febrile nor local oral infectious complications were significantly different. These results suggest that nontreatment of asymptomatic postendodontic periapical radiolucencies does not increase the incidence of infectious complications during bone marrow transplantation.

Adult↗
PubMed1993

Lingual mandibular sequestration and ulceration.

This study analyzed 11 patients who had small sequestra associated with ulceration of the lingual mucosa in the posterior mandibular molar area at the level of the mylohyoid ridge. The patients were adults (mean age, 45.3 years) with complaints of sensitive, occasionally painful lesions that appeared for periods that ranged from 1 week to several months. No abnormalities were evident on periapical radiographs; however, in three cases in which occlusal radiographs were available, small irregular radiopacities contiguous with the cortex were noted. Spontaneous exfoliation or surgical removal of the sequestrum resulted in resolution of the lesion. The possible etiologic factors associated with this apparent clinical-pathologic entity are discussed.

Adult↗
PubMed1993

Legume-associated residual cyst.

This report describes three unique cases of residual cyst (RC) which were characterized by large legume implants. To determine whether these represented a distinctive RC subset or if implanted materials have general importance in RC pathogenesis, a retrospective comparison of these cases and 37 further RCs with 40 control periapical cysts was performed. The frequency of foreign material implantation and the associated histopathologic features were assessed. No significant differences were noted suggesting that foreign implantations do not have an etiologically significant association with RCs and that the legume-associated RCs represent a unique subgroup. The relationship of the legume-associated RCs to the category of lesions variously termed giant cell hyaline angiopathy, oral pulse granuloma or hyaline ring granuloma is discussed.

Adult↗
PubMed1993

Adolescents' views of work and leisure in The Netherlands and the United States.

During early adolescence, youth begin to make choices about their future. Sundberg and Tyler (1970) found differences between adolescents in the Netherlands and the United States as to their possibilities for future occupations and leisure activities. Since there have been many changes in both countries over the past twenty-five years, the present study was designed as a replication and expansion of that research. Participants were 522 14- and 15-year-olds in the Netherlands and the United States who filled out the Sundberg and Tyler questionnaire (in the original Dutch and English forms) and drew a picture of the ideal man or woman engaged in an activity. Two-way (country by gender) ANOVAs indicated that the number of occupations listed was greater for adolescents in the Netherlands than in the United States, and that girls listed more occupations than did boys, but considered fewer occupations as actual possibilities for themselves. There was an apparent increase in the number of leisure activities listed by adolescents in the Netherlands. In the U.S., the ideal person was more often drawn as being at work (44.9%) as compared with the Netherlands (20.4%). U.S. students seemed more inclined to glamorize work; popular drawings had themes which linked work and success, achievement and wealth. Dutch students seemed to be interested in quality of life; their drawings depicted sports, relaxation, attractiveness, and humor.

Adolescent↗