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Biomedical subjects

M Beck

Publications and source records attributed to M Beck.

357 records · Page 20Linked to original sources
PubMedDate not supplied

[Extent and effect of fermentation in the large intestine of swine. 2. Extent of fermentation, pattern of volatile fatty acids and in vitro formation rate].

After adaptation to 8 extremely different rations 40 pigs with 108 to 125 kg LW and 6 lactating sows with 183 kg were slaughtered to obtain digesta of the hindgut. From digesta of caecum and three sections of the colon microbial metabolites and in vitro-VFA-production rates were determined. pH-values increased from 5.5 to 6.3 from caecum to the end of colon. VFA-concentrations and -production-rates decreased along the bowel to one third. Highest fermentations came from rations with 50% dried beet pulp. Daily VFA-production per animal were placed between 799 and 3,134 mmol. Concerning VFA-Mol-%, ileal influx of cellulose increased acetate, high intakes raised butyrate and valeriate. By several reasons the IMOTO-method of in vitro-measuring was censured.

Animal Feed↗
PubMedDate not supplied

Entry point soft tissue damage in antegrade femoral nailing: a cadaver study.

INTRODUCTION: Little attention is paid to insertion site morbidity associated with antegrade femoral nailing. However, residual peritrochanteric pain after nailing is not uncommon. Additionally, the end branches of the medial femoral circumflex artery (m.f.c.a.) supplying the femoral head are in close proximity to the insertion site of the nail, and the occurrence of avascular necrosis of the femoral epiphysis after nailing in adolescents is rather frequent. OBJECTIVE: The aim of this study was to assess iatrogenic soft tissue injuries at the site of nail insertion. MATERIALS AND METHODS: Nailing with a reamed AO universal femoral nail was performed on sixteen adult cadavers followed by dissection of the proximal part of the femur to assess possible damage to the soft tissues. Three entry portals were defined. (A) entry portal lateral to the junction of the neck and the greater trochanter; (B) entry portal at the base of the greater trochanter anterior to a line along the longitudinal axis of the femoral neck; and (C) entry portal at the base of the greater trochanter posterior to a line along the axis of the femoral neck (at the piriformis fossa). RESULTS: In Group A, partial avulsion of the piriformis and the obturator internus tendon were present in four and in one of five specimens, respectively. Group B showed injuries to the piriformis tendon in two and to the gluteus minimus tendon in one of four cases. In Group C, partial avulsion of the piriformis, obturator internus, and obturator externus tendon were encountered in five, six, and two of seven specimens, respectively. Anterior branches of the ramus profundus of the m.f.c.a. within the synovial fold were damaged in all of these cases. CONCLUSION: To select the best nail entry portal, the ease of nail insertion must be weighed against the resulting soft tissue damage at the site of insertion. The nail entry portal at the piriformis fossa, although geometrically ideal and most recommended, causes the most significant damage to muscle and tendons as well as to the blood supply to the femoral head. Therefore, even if reported only once, the occurrence of avascular necrosis of the femoral head after nailing in adults is a possible complication of this nail entry portal. The authors therefore prefer to avoid this entry portal in every case. The nail entry portal anterior to the longitudinal axis of the femoral neck, as in group B, although better with respect to the soft tissue damage, has the worst geometric and biomechanical disadvantages. The results of the current study favor the nail entry portal lateral at the greater trochanter as in Group A, which is equal to the entry portal B with respect to the soft tissue damage but allows introduction of the nail into the medullar cavity without difficulties.

Bone Nails↗
PubMedDate not supplied

The testing of cell invasiveness in embryonic tissue and in cell culture.

The subcutis of 11-day-old chick embryos, 15- to 18-day-old mouse embryos and the skin muscle tissue of human fetus were stretched on lens paper in a Petri dish and seeded with a piece of LED-Widr or HDC cell sheet. Mem + 10% FCS was added. After three days incubation the material was fixed, sectioned and H-E stained. In the second part of our investigation several cell lines were prepared on cover slips. When confluent, the cultures were inoculated with 1-2 drops of cell suspension of another cell line. Three days after the seeding of cell suspension on the confluent cell sheet the cultures were fixed and stained. It can be seen in the organ cultures that LED-Widr cells closely adhere to the embryonic tissue which in some places they are invading. In tissue culture examination we found that heteroploid cells seeded on a confluent sheet of diploid cells adhered but that a diploid cell seeded on epithelial-like heteroploid cells would not adhere. The testing of invasiveness in embryonic tissue in organ culture showed that it can be a useful model. By seeding suspended cells of fibroblast lines on a confluent sheet of heteroploid cell lines their contact inhibition or their invasive ability can be determined. The seeding of heteroploid cell lines on diploid cell lines can be used as a model for the study of the mechanism of invasion into normal tissue and for the in vitro study of invasion inhibiting properties of certain substances.

Animals↗
PubMedDate not supplied

An evaluation of 4% prilocaine with 1:200,000 epinephrine and 2% mepivacaine with 1:20,000 levonordefrin compared with 2% lidocaine with:100,000 epinephrine for inferior alveolar nerve block.

The purpose of this study was to measure the degree of anesthesia obtained with 4% prilocaine with 1:200,000 epinephrine and 2% mepivacaine with 1:20,000 levonordefrin compared with 2% lidocaine with 1:100,000 epinephrine for inferior alveolar nerve block. Using a repeated measures design, 30 subjects randomly received an inferior alveolar injection using masked cartridges of each solution at three successive appointments. The first molar, first premolar, lateral incisor, and contralateral canine (control) were blindly tested with an Analytic Technology pulp tester at 3-min cycles for 50 min. Anesthetic success was defined as no subject response to the maximum output of the pulp tester (80 reading) within 16 min and maintenance of this reading for the remainder of the testing period.Although subjects felt numb subjectively, anesthetic success as defined here occurred in 46% to 57% of the molars, in 50% to 57% of the premolars, and in 21% to 36% of the lateral incisors. No statistically significant differences in onset, success, failure, or incidence were found among the solutions. We conclude that the three preparations are equivalent for inferior alveolar nerve block of 50-min duration.

Adult↗
PubMedDate not supplied

[The effect of vaginal administration of interferon on squamous intraepithelial cervical lesions].

Human papillomavirus vaginal and/or cervical infections were found in 1.98 percent of mostly younger female general populations and in 26.6 percent of cases with abnormal Pap smears. Antiviral treatment with human leukocyte interferon (HLI-alpha) vaginalettes was introduced at the beginning of 1987. In 30 cases a daily dose of 1 x 10(6) IU HLI during two 21-day menstrual cycles was applied. In 137 controls without therapy and the treated group a 12-month follow-up was performed. Every third month the regression, persistence or progression of the cervical squamous intraepithelial lesion (SIL) was determined by cytology and colposcopy. Most of the cases with progression were histologically confirmed. For ethical reasons the placebo treatment of the control group with an identical spectrum of disease was not feasible. Therefore, a secondary analysis and the 2 test were used. Up to now the results show a significant regression (21 out of 30, X2 = 4.51, P less than 0.05) in the treated group and progression (23 out of 137, X2 = 18.41, P less than 0.01) in controls. HLI vaginalettes are easily applicable, without any side-effects.

Administration, Intravaginal↗
PubMedDate not supplied

A comparison of the periodontal ligament injection using 2% lidocaine with 1:100,000 epinephrine and saline in human mandibular premolars.

The purpose of this study is to evaluate, with the electric pulp tester, the anesthetic efficacy of the periodontal ligament injection using 2% lidocaine with 1:100,000 epinephrine and saline in human mandibular premolars. The periodontal ligament injection using 2% lidocaine with 1:100,000 epinephrine was found to be an effective technique for anesthetizing mandibular first premolars. However, the duration of profound pulpal anesthesia was approximately 10 minutes. The periodontal ligament injection using sterile saline was not an effective technique for anesthesia. Teeth mesial and distal to the injected tooth may also become anesthetized with this injection technique. The initial needle penetration and injection of the anesthetic solution in clinically healthy teeth were only mildly discomforting. No increase in tooth mobility was observed 45 minutes after the periodontal ligament injection. No clinically observable pulpal or periodontal damage was seen at 3 weeks after the injection.

Anesthesia, Dental↗
PubMedDate not supplied

Ocular assessment of patients treated with tamoxifen.

Tamoxifen is a specific estrogen antagonist used in the treatment of breast cancer. In a previous study, corneal and retinal changes were reported in four patients receiving high-dose tamoxifen therapy for greater than 1 year. Nineteen patients treated with tamoxifen for periods of 3 months to 4 years at normal dose levels have been studied and no ocular changes attributable to the drug were observed.

Aged↗