Selective myectomy for postparetic facial synkinesis

Synkinetic movements are secondary to facial palsy because they appear like a late sequela to spontaneously healing facial nerve injury. They are produced by an involuntary contraction of a muscle group simultaneous with contraction of other homologous muscle groups. The disorderly regeneration of severed axons is responsible for these movements. According to the Lippschitz theory, the regenerating nerve fibers sprout into the wrong peripheral branches. Between 1975 and 1986, 71 patients with facial paralysis were evaluated. Spontaneous recovery from the facial paralysis occurred in 28 of these patients; 14 (50 percent) developed synkinetic movements, and surgical treatment was sought by only 6 patients. In all patients, the lesion of the facial nerve was in the trunk, proximal to the principal ramification. The most frequent clinical finding was simultaneous activation between the orbicularis oculi and the elevators of the corner of the mouth (12 patients) or the elevators of the upper lip (2 patients). In 8 patients, in whom the slight synkinesis was not noticed by the patients, surgical correction was not necessary, but in the other 6 patients with severe aesthetic disturbances, surgical treatment for "disconnection" of the wrong impulses was realized. I obtained this "disconnection" through resection of the involved perioral muscle groups instead of paralysis of the orbicularis oculi. Follow-up of the 6 patients operated with the surgical treatment proposed herein for between 4 and 8 years has shown good aesthetic results without functional or aesthetic sequelae.     

Mutations induced by ionizing radiation in a plasmid replicated in human cells. I. Similar, nonrandom distribution of mutations in unirradiated and X-irradiated DNA

The Escherichia coli supF gene encoding the suppressor tyrosine tRNA in a human shuttle plasmid, pZ189, was used as a target for molecular analysis of X-ray-induced mutations in human lymphoblastoid cells. Following replication of the in vitro-irradiated plasmid in human cells, the mutant supF-containing molecules were cloned by phenotypic screening in E. coli and the nature of the mutations was determined by direct sequencing of the tRNA gene. At 160 Gy the mutant frequency was 13 times (0.39%) that observed in unirradiated controls (0.031%). When control plasmid was replicated directly in E. coli, the mutant frequency was 16 times less than that of the plasmid passaged through the human cells. The distribution of mutations was highly nonrandom and remarkably similar in both irradiated and control DNAs. The majority of the mutations were transitions involving G.C pairs and occurred selectively at most 5'-TC (3'-AG) sequences. These mutations at C's were preferentially distributed in the nontranscribed strand. We propose that mutations in the control plasmid result from oxidative damages that occur during and/or after its incorporation into human cells and that these damages are similar to those induced by ionizing radiation. The hot spots for mutations suggest that the proximate nucleotide sequence and the overall conformation of the target DNA are important in the production and/or processing of these damages during repair and replication.     

The recovery of the reactivity of the auditory system in the dolphin Tursiops truncatus to paired acoustic stimuli with different spectra]

Recovery cycles of the auditory brainstem responses were studied in the bottle-nosed dolphin, Tursiops truncatus, using paired acoustic clicks. The recovery time was longer if both clicks had identical spectra (50% recovery at 0.9 ms), as compared with that of different spectra (50% recovery at 0.35 ms). These results can explain a different recovery time of evoked responses after an artificial sound and after own locating one.     

The electroencephalographic and autonomic correlates of the mental reproduction of emotional states]

The present study is devoted to the analysis of changes of bioelectrical and vegetative indices at mental reproduction of emotional states by man. Analysis is conducted of the data of mapping of intracortical interactions depending on the dynamics of R-R interval changes. Two stages of mental reproduction of emotions are revealed which are characterized by the presence of different centers of integration--in the frontal and temporal parts of the brain cortex. It is shown that at maximum emotional stress the integration center shifts from the frontal regions to the temporal region of the left hemisphere.     

Quantitative characteristics and reconstruction of the surface topography of histochemical markers on nerve cell plasmalemma

An electron-microscopic study of the topography of carbohydrate residues on the surface of the cell body membrane of cultured spinal neurons was carried out using lectins from wheat (WGA) and snail (HPL), labeled with colloidal gold, as specific molecular probes. Mathematical methods of analysis suggested a set of surface markers, from the distribution of particles observed in electron micrographs of random sections, corresponding to two random functions. Analysis of these functions allows the required quantitative characteristics to be obtained. The Monte Carlo reconstructing model is described, and results of its use (based on the aforementioned experimental data) are demonstrated in the form of "averaged" surface topography of the studied markers in a limited section of the membrane. The results obtained are discussed in connection with cooperative properties of the membrane.A. A. Bogomolets Institute of Physiology, Academy of Sciences of the Ukrainian SSR, Kiev. Translated from Neirofiziologiya, Vol. 23, No. 5, pp. 595–603, September–October, 1991.     

Metalloproteinases mediate extracellular matrix degradation by cells from mouse blastocyst outgrowths.

The maintenance and developmental remodeling of extracellular matrix is crucial to such processes as uterine implantation and the cell migratory events of morphogenesis. When mouse blastocysts are placed in culture they adhere to extracellular matrix, and trophoblast giant cells migrate out onto the matrix and degrade it. The secretion of functional proteinases by developing mouse embryos increases dramatically at the time of implantation. By zymography we identified the major secreted gelatin-degrading proteinase, also known as type IV collagenase, as one migrating at 92 x 10(3) Mr. Several casein-degrading proteinases were also secreted. The tissue inhibitor of metalloproteinases (TIMP) inhibited all of the embryo-derived proteinases detected by gelatin gel zymography, indicating that they are metalloproteinases, whereas TIMP did not inhibit all of the caseinases. Urokinase was also secreted. Addition of TIMP at 5-500 nM effectively inhibited the degradation of matrix by the trophoblast outgrowths. Blocking antibodies directed against 92 x 10(3) Mr gelatinase abolished matrix degradation by the trophoblast cells. These observations suggest that several metalloproteinases are regulated in early development and that 92 x 10(3) Mr gelatinase, in particular, has a rate-limiting function in degradation of the maternal extracellular matrix by trophoblast cells.     

Genetically defined lysosomal acetylesterase EC 3.1.1.6 in the cauda epididymidis of mouse,rat, and man

After inhibition by bis-p-nitrophenyl phosphate and subsequent staining for esterase using naphthol AS-D acetate as the substrate, a strong lysosomal esterase was demonstrated in the cauda epididymidis of mouse, rat, and man. Owing to its behaviour towards the classifying inhibitors eserine, diisopropyl fluorophosphate, bis-p-nitrophenyl phosphate, and p-chloromercuriphenylsulphonate, this lysosomal esterase was shown to be an acetylesterase (EC 3.1.1.6). Control experiments involving isoelectric focusing revealed that this acetylesterase was identical with the genetically defined homologues ES-17, ES-6, and ES-A4 in mouse, rat, and man, respectively.     

The methyltrienolone binding protein of JEG-3 cells and human placenta is localized within the nucleus and is tightly associated with chromatin.

Human placenta contains the methyltrienolone binding protein (MTBP), an androgen binding protein which is distinct from the androgen receptor. This study demonstrates that the human choriocarcinoma cell line (JEG-3) also contains the MTBP and that in both human placenta and JEG-3 cells the MTBP is located exclusively in the nucleus and in particular is associated with DNase 1 resistant chromatin.