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Biomedical subjects

B Meyer

Publications and source records attributed to B Meyer.

At least 361 records · Page 20Linked to original sources

The activity of Balbiani rings 1 and 2 in salivary glands of Chironomus tentans larvae under different modes of development and after pilocarpine treatment.

The activity of the Balbiani rings 1 and 2 (BR1 and BR2) in the salivary gland was followed during development of fourth instar larvae of Chironomus tentans under different modes of development, with or without a previous pilocarpine treatment. The activity was determined in parallel by two different methods, by incorporation of [3H]uridine into BR-RNA (75 S) and by morphometry of BR1 and of BR2. In glands of untreated larvae BR2 does not change dramatically except for a depression of activity during oligopause (resting phase). BR1 is completely inactive during this phase but exhibits a pronounced activity maximum in the middle of the prepupal period, in subitaneously developing (i.e., uninterrupted) as well as in postoligopause cultures. After pilocarpine treatment the activity of BR2 (rather than of BR1) is generally increased. The extent of this stimulation, however, is strongly development dependent. A most striking activity difference is observed in postoligopause between animals of stage 5 and of stage 6. The relationship between BR2 activity and degree of emptying of the salivary gland lumen was investigated. A model is proposed in which BR2 activity is conceived as being regulated by two parameters: by the degree of filling of the gland lumen and by the stage and mode of development of the larva.

Age Factors↗

Long-term results of the multichannel cochlear implant.

Clinical results obtained with the multichannel cochlear implant are described in 48 cases of total deafness (27 cases of prelingual and 21 cases of postlingual deafness). The tolerance for implanted material and the survival of the electrode-nerve interface have not yet been altered after more than 5 years. After some months of training the patients, the percentages of phoneme-, word-, and sentence-recognition vary from one patient to another, but depend approximately on the value of the threshold level of the round-window stimulation test, and the degree of socialization of each patient. These results suggest that the multichannel cochlear implant may now be considered as a useful tool in the rehabilitation of totally deaf persons.

Adolescent↗

Insulin binding to erythrocytes before and after changing from porcine to biosynthetic human insulin in children with type-I diabetes.

The binding of [125I]insulin to isolated erythrocytes from diabetic children (n = 27) before (group a) as well as one and five months after changing from porcine to biosynthetic human insulin (groups b and c) was investigated. An analysis of variance of the binding parameters, determined by a nonlinear regression procedure, yielded statistically significant differences between the receptor affinities Ka as well as between the receptor concentrations Xo of the groups a and b, a and c and b and c. (formula: see text). The results suggest that the change from porcine insulin to biosynthetic human insulin induces a short-term as well as long-term increase in the affinity, and a decrease in the concentration of the erythrocyte insulin receptors.

Adolescent↗

Insulin binding to erythrocytes in children with type-I diabetes mellitus.

Specific binding of [125I]insulin to isolated erythrocytes was investigated in four groups of children (A) Healthy children under 10 years of age (n = 20) (B) Healthy children over 10 years of age (n = 13) (C) Diabetic children under 10 years of age (n = 12) (D) Diabetic children over 10 years of age (n = 63). In addition, all diabetic children (n = 75) were subdivided into four groups according to the duration of diabetes. (E) less than 2 years, (F) 2--4 years, (G) 4--6 years, and (H) greater than 6 years. By means of a nonlinear regression analysis for the extraction of binding parameters (assuming a single receptor class model with independent receptor sites) and methods of variance analysis, statistically significant differences were observed for the receptor affinities Ka (10(8) l/mol) and the receptor concentrations X0 (nmol/l) between groups A and C, B and D, C and D, but not between A and B. The affinities of groups C and D were found to be higher than the corresponding values of groups A and B, whereas the receptor concentrations exhibited an inverse behaviour. A significant increase of the receptor concentration and decrease of the receptor affinity depending on the duration of diabetes could only be proved to exist during the first 2 years of the disease.

Adolescent↗

[Effect of chronic electric stimulation of the auditory nerve on the development of the cochlear nuclei in guinea pigs].

14 newborn guinea pigs have been deafened three days after birth by bilateral destruction of the organ of Corti, and among them 8 have been supplied with a chronic auditory electric stimulation by mean of an intra-cochlear implanted electrode. The histological study and the anatomical reconstructions of these animals' cochlear nuclei demonstrate that this chronic stimulation prevent at least partially these auditory pathway medullary formations from the atrophy due to the cochlear destruction.

Animals↗

Diagnosis of Mycoplasma pulmonis infection of rats by an indirect immunofluorescence test compared with 4 other diagnostic methods.

Efficiency of indirect immunofluorescence microscopy (IFM) for detection of M. pulmonis antibody (IgG) in rats was compared with results of enzyme-linked immunosorbent assay (ELISA), complement fixation (CF), cultural isolation and histopathology. IFM was carried out on M. pulmonis infected BHK-21 cells grown on cover slips or multitest slides. After acetone fixation these antigen carriers could be stored at -20 degrees C for several months so that serological tests could be done at any time and completed within 2 h. The IFM was strain specific and the sensitivity of the test was comparable with that of the ELISA, whereas the CF-test proved to be very insensitive. For routine monitoring, only in cases of fresh infections should time consuming cultural procedures be preferred to serological tests. Chronic disease stages were readily detected by histological examination.

Animals↗

Colposcopic and histologic findings in cervical chlamydial infection.

Colposcopic and histologic findings in 41 patients with Chlamydia trachomatis-associated cervicitis and in age-matched controls with nonspecific cervicitis are presented. Colposcopy showed exophytic follicular cervicitis in 30 patients in the chlamydia group and in none in the control group. Atypical transformation zone occurred significantly more often in the chlamydia group. Directed biopsy specimens revealed cervical intraepithelial neoplasia in 10 cases in the chlamydial group but in only 1 case in the control group. In 4 patients with chlamydial cervicitis lymphoid follicles were observed in histologic specimens.

Adult↗

[Microcomputer applications in otorhinolaryngology (author's transl)].

Two main types of utilisation of microcomputers in otorhinolaryngology are envisaged: instrumentation and medical audit. The modes of employ of the material in these fields are briefly exposed, followed by the presentation of several examples of its employ and functioning. Practical notions are discussed, particular emphasis then being placed on theoretical considerations involved in the use of such equipment. Of primary importance are strictly medical reflections, problem solving being facilitated (by suppressing or diminishing routine tasks) but never simplified.

Computers↗

[Treatment of dysphonia spastica by recurrent nerve resection (author's transl)].

Fifteen-month follow-up of a patient with severe dysphonia spastica treated by recurrent nerve resection showed that complete recovery had been obtained. Pathological findings, and the results of sonographic, phonographic, glottographic, and electromyographic examinations in this affection are discussed, and an attempt made to deduce the mechanism of action of this resection, and to establish the most valid indications for its employ.

Female↗