[EXPERIMENTAL POSTTERIOIDEKTOMIC FATTY LIVER DISEASE IN RATS].

UNLABELLED: The aim was to investigate the morphological features of the liver in animals at different periods of post-operative hypothyroidism to reproduce the experimental fatty liver disease. MATERIALS AND METHODS: thyroidectomy was performed 20 laboratory rats, females breed nonlinear, thyroid was mobilized without thyroid thyroidectomy to 10 individuals. The morphological pattern of the rat's liver was studied in terms of 4 and 8 weeks after surgery at the light optical level. RESULTS: 4 weeks after thyroidectomy was found in rat liver protein and fatty degeneration with focal of inflammatory infiltration, against the backdrop of a serous edema. On the 8th week of the experiment observed the progression of degenerative, necroinflammatory processes expressed hydropic dystrophy, atomizing steatosis and the appearance of periportal fibrosis.

Increased T-type Ca2+ channel activity as a determinant of cellular toxicity in neuronal cell lines expressing polyglutamine-expanded human androgen receptors.

We have analyzed Ca2+ currents in two neuroblastoma-motor neuron hybrid cell lines that expressed normal or glutamine-expanded human androgen receptors (polyGln-expanded AR) either transiently or stably. The cell lines express a unique, low-threshold, transient type of Ca2+ current that is not affected by L-type Ca2+ channel blocker (PN 200-110), N-type Ca2+ channel blocker (omega-conotoxin GVIA) or P-type Ca2+ channel blocker (Agatoxin IVA) but is blocked by either Cd2+ or Ni2+. This pharmacological profile most closely resembles that of T-type Ca2+ channels [1-3]. Exposure to androgen had no effect on control cell lines or cells transfected with normal AR but significantly changed the steady-state activation in cells transfected with expanded AR. The observed negative shift in steady-state activation results in a large increase in the T-type Ca2+ channel window current. We suggest that Ca2+ overload due to abnormal voltage-dependence of transient Ca2+ channel activation may contribute to motor neuron toxicity in spinobulbar muscular atrophy (SBMA). This hypothesis is supported by the additional finding that, at concentrations that selectively block T-type Ca2+ channel currents, Ni2+ significantly reduced cell death in cell lines transfected with polyGln-expanded AR.

[The epidemiological characteristics of fatal subdural hematomas in forensic medical practice]. / Epidemiologicheskie osobennosti smertel'nykh subdural'nykh gematom v sudebno-meditsindskoi praktike.

A retrospective analysis of subdural hematomas is carried out: 493 in subjects dead from mechanical injuries (from files of forensic medical morgues in Tver', 1992-1994), and 37 cases with chronic subdural hematomas (from files of forensic medical morgues No. 2 and 6 in Moscow, 1995-1997). Age and sex of victims, time and circumstances of injuries, topographic and morphological features of subdural hemorrhages and their relation to concomitant injuries, and presence of ethyl alcohol in the organism are studied. The data on chronic subdural hematomas are presented. The authors emphasize the need in forensic medical studies of this condition.

Okadaic acid enhances prepulse facilitation of cardiac alpha 1-subunit but not endogenous calcium channel currents in Xenopus laevis oocytes.

Xenopus laevis oocytes can be selected to express relatively high levels of endogenous Ca currents. These currents are facilitated by prepulses. Facilitated endogenous Ca currents are unaffected by okadaic acid, RpcAMPS or the dihydropyridine (DHP) antagonist (+) PN 200-110. The endogenous currents and facilitation of endogenous currents by depolarizing prepulses are fully blocked by 1 mM Cd2+. In contrast, oocytes injected with mRNA encoding for the rabbit cardiac alpha 1-subunit express prepulse-facilitated Ca channel currents that are highly enhanced by the phosphoprotein phosphatase inhibitor okadaic acid (3-fold) and blocked by RpcAMPS and the DHP antagonist (+) PN 200-110. While okadaic acid selectively stimulates prepulse facilitation of cardiac alpha 1-subunit Ca currents, the DHP agonist (+) SDZ 202-791 largely increases (5-fold) both the control (before prepulse) and facilitated currents (after prepulse). (+) SDZ 202-791 did not prevent the effect of RpcAMPS or okadaic acid on facilitation of cardiac alpha 1-subunit, suggesting that DHP stimulation is independent of phosphorylation leading to channel facilitation. The enhancement of prepulse facilitation of cardiac alpha 1L-subunit Ca channel current by okadaic acid can be accounted for by a speeding up in the rates of onset during the prepulse. Inhibition of phosphoprotein phosphatases by okadaic acid has only modest effects on the rates of recovery of cardiac alpha 1-subunit Ca channel current from facilitation in the time immediately following the prepulse.

Regeneration in denervated toad (Bufo viridis) gastrocnemius muscle and the promotion of the process by low energy laser irradiation.

BACKGROUND: It is known that while denervated skeletal muscles have the ability to regenerate, maturation of regenerated myofibres does not take place under these conditions. Denervation also causes elevation of "invasive" and satellite cells, but the role of these cells in the regeneration process after injury to the denervated muscle is still unknown. Low energy lasers have recently been found to modulate and accelerate physiological processes in cells. The aim of the present study was to compare regeneration in denervated and innervated amphibian muscles and to investigate whether this process in denervated muscles can be stimulated by low energy laser irradiation prior to injury in these muscles. METHODS: Denervated gastrocnemius muscles of toads were irradiated with He-Ne laser (6.0 mW, 31.2 J/cm2) 7 days postdenervation (control muscle received red light irradiation at the same wavelength). Nine days after denervation cold injury was performed on the site of irradiation of both groups of muscles. At 14 days postinjury all muscles were removed and processed for histology and histomorphometric analysis of mononucleated cells, myotubes, and young myofibres in the regenerated zone. RESULTS: The volume fraction (percent of total injured zone) of the various histological structures in the injured zones 14 days after cold injury in the denervated (9 days prior to injury) muscles did not differ from innervated injured muscles at the same time interval postinjury. The mononucleated cells and myotubes in the laser irradiated muscles comprised 49 +/- 4% and 6 +/- 1% of the injured area, respectively, which was significantly lower than their volume fraction (67 +/- 2% and 11 +/- 2%, respectively) in the control muscles. The young myofibres populated 34 +/- 4% of the total injured area in the denervated and laser irradiated muscles which was significantly higher than their volume fraction (12 +/- 2%) in control denervated muscles. CONCLUSIONS: It is concluded that initial stages of regeneration can also take place in skeletal denervated and injured muscles of amphibians. The kinetics of the regeneration process are identical in denervated and innervated muscles. The process of regeneration in denervated muscles can be markedly enhanced if the muscle is irradiated by low energy laser prior to injury, probably by activation (stimulation of proliferation and/or differentiation) cells in the muscles that are "recruited" and participate in the process of regeneration.

Enhancement of angiogenesis in regenerating gastrocnemius muscle of the toad (Bufo viridis) by low-energy laser irradiation.

The effect of low-energy laser (He-Ne) irradiation on the process of neoformation of blood capillaries during regeneration in the toad (Bufo viridis) gastrocnemius muscle was studied using histomorphometric methods. The injured zones of the experimental toads were subjected to four direct He-Ne laser irradiations (632.8 nm wavelength; 6.0 mW for 2.3 min) every alternate day, commencing on the second day after injury. Muscles that were injured as above and subjected to red light irradiation served as control. The volume density (cm3/cm3) of the capillaries in the injured zone at 9 days after injury was significantly (P < 0.01) higher (0.09 +/- 0.006) than in the control muscles (0.048 +/- 0.007). At 14 days after injury, the volume density in the injured zone of the control muscles further increased, while the value in the laser-irradiated muscles remained unchanged. The surface density (m2/cm3) of the capillaries in the injured zone was 2.3-fold higher in the laser-irradiated muscles than in the control muscles at 9 days after injury. The surface density further increased in the control muscles between 9 and 14 days after injury, while in the laser-irradiated muscles there was a decrease in this value during the above period. The surface-to-volume ratios of the capillaries in the injured zone of control and laser-irradiated muscles indicate a straighter, rather than a convoluted appearance between 9 and 14 days after injury. It is concluded that He-Ne laser irradiation during skeletal muscle regeneration in the toad markedly promotes the process of neoformation of blood vessels in the injured zone.(ABSTRACT TRUNCATED AT 250 WORDS)

Attenuation of the process of muscle regeneration in the toad gastrocnemius muscle by low energy laser irradiation.

The effect of number, frequency, and timing of HeNe (6.0 mW; 31.2J/cm2) and Ga-As-diode (average power at 2.82 Hz-0.005 mW) laser irradiations on the process of muscle regeneration at 14 days following cold injury to the toad gastrocnemius muscle was investigated using histomorphometric methods. The volume fraction (percent of total injured area) of mononucleated cells, myotubes and degenerated fibers was 10 +/- 1%, 0%, and 4 +/- 1%, respectively, in the HeNe laser irradiated muscles (5 irradiations every alternate day, beginning on the 4th day after injury), whereas in the control nonirradiated muscles, these values were significantly higher comprising 57 +/- 2% (P < 0.01), 11 +/- 1% and 10 +/- 2% (P < 0.05), respectively. The volume fraction of young myofibers in injured areas that were subjected to the same laser irradiation regime was 8.6-fold significantly higher (P < 0.01) than their volume fraction in control muscles. The histomorphometric results were the same for injured zones of muscles that were laser irradiated only once, on the 9th day postinjury, and for those that received five consecutive irradiations every alternate day. Muscle regeneration was equally promoted by single Ga-As-diode laser or HeNe irradiation. Multiple irradiations of Ga-As-diode laser caused some pathological changes in the newly formed muscular structures. It is concluded that the process of skeletal muscle regeneration is markedly promoted by low energy laser irradiations, but that the effect depends on the number, timing, and frequency of irradiations and the type of laser used.

Promotion of muscle regeneration in the toad (Bufo viridis) gastrocnemius muscle by low-energy laser irradiation.

The effect of low-energy laser (He-Ne) irradiation on the process of skeletal muscle regeneration after cold injury to the gastrocnemius muscle of the toad (Bufo viridis) was studied using quantitative histological and morphometric methods. The injured zones in the experimental toads were subjected to five direct He-Ne laser (632.8 nm wavelength) irradiations (6.0 mW for 2.3 min) every alternate day starting on the fourth day postinjury. Muscles that were injured as above, and subjected to red-light irradiation, served as a control group. Morphometric analysis was performed on histological sections of injured areas at 9, 14, and 30 days postinjury. At 9 days postinjury, mononucleated cells populated 69.3% +/- 16.8% of the total area of injury. Thereafter, their volume fraction (percent of total injured zone) decreased gradually but more rapidly in the laser-irradiated muscle than in the control. The volume fraction of the myotubes in the laser-irradiated muscles at 9 days of muscle regeneration was significantly higher (7.0% +/- 2.2%) than in the control muscle (1.2% +/- 0.4%). Young myofibers in the laser-irradiated muscles populated 15.5% +/- 7.9% and 65.0% +/- 9.5% of the injured area at 9 and 14 days of muscle regeneration, respectively, while in control muscles these structures were not evident at 9 days and made up only 5.3% +/- 2.9% of the traumatized area at 14 days postinjury. The volume fraction of the young myofibers further increased by 30 days of muscle regeneration making up 75.7% +/- 13.2% of the traumatized area, while in the laser-irradiated muscles most of the injured zone was filled with mature muscle fibers.(ABSTRACT TRUNCATED AT 250 WORDS)

[Neural differentiation of ectodermal explants of the early gastrula from Rana temporaria under the action of various mitogens and kainic acid]. / Neiralizatsiia éksplantatov éktodermy rannei gastrula Rana temporaria pod deistviem razlichnykh mitogenov i kainovoi kisloty.

The following mitogens: concanavalin A (con A), phytohemagglutinin (PHA), hydra growth factor (HGF) as well as neurotoxic agent kainic acid, caused neural differentiation (N) effects differed in value and also in character of dependence on concentration of the agent. The lowest effective concentration of con A was 75 micrograms/ml (15% neural differentiation, treatment during 3 h), and the effect reached maximum of 50-60% at 100-200 micrograms/ml. Con A concentration 50 micrograms/ml showed no effect but after 1% rabbit gamma-globulin was added, 17% neural differentiation was detected. N-effects observed after treatment of explants with con A (200 micrograms/ml, 3h) at 2 degrees and 21 degrees were similar (58 and 42% respectively). Minimum PHA concentration used (6 micrograms/ml, 18h) led to neural differentiation in 5% of explants. N-effect of PHA increased along with the concentration of the lectin and was most pronounced at 25 micrograms/ml. However, further increase in concentration (up to 200 micrograms/ml) resulted in decrease of its N-effect to 13%. At 12 micrograms/ml PHA exerted not only neural differentiation, but also lens-inducing (32%) action on the ectoderm. N-effect of HGF (2.5, 25 and 250 micrograms/ml) was lower as compared with the maximum effects of con A and PHA (30-35%). No correlation of HGF inducing action with its concentration was observed. Kainic acid showed weak N-effect (20-30%) at 1 and 10 micrograms/ml. Higher concentration (100 micrograms/ml) had no N-effect, but in 27% of explants "free" lentoids were found. Oubain (10(-3) and 10(-4) M) and HEPES (20 mM) did not affect the differentiation of explants.

[A hormone-sensitive stage in the development of the retinal pigment epithelium in Hunter rats with hereditary retinal dystrophy]. / Gormonochuvstvitel'naia stadiia v razvitii pigmentnogo épiteliia setchatki u krys Hunter s nasledstvennoi distrofiei setchatki.

The sensitivity of the retinal pigment epithelium (RPE) to the melanotropic effects of alpha-MSH and dbcAMP was assayed in an organ culture of the eye scleral part in the Hunter rats with inherited retinal dystrophy. The melanin synthesis was estimated by liquid scintillation on the RPE isolated enzymatically after 48-h cultivation. One eye from every animal was cultivated in a medium without natural components and with the hormone or dbcAMP (experiment), while the other in a hormone-free medium (control). The melanin synthesis was estimated by 14C-thiouracil incorporation. The result was expressed as a cpm/microgram DNA (experiment) to cpm/microgram DNA (control) ratio. In addition, the index of labelled nuclei was determined using 3H-thymidine autoradiography in the central RPE zone of the eyes from young rats of the same litter. The experiments with alpha-MSH confirmed the earlier data according to which the RPE of the 3 day old Hunter rats were insensitive to melanotropic hormones. This was not due to defects in the cytoplasmic melanin-synthesizing system, since under the influence of dbcAMP the melanin synthesis in the RPE increases more than four-fold as compared with the control; dbcAMP stimulates also the total protein synthesis, as estimated by 3H-leucine incorporation. The RPE of the 4 day old rats proved to be sensitive to alpha-MSH: the melanin synthesis increases more than twice suggesting the healthy state of the RPE membrane melanotropic receptors. alpha-MSH also stimulates the total protein synthesis.(ABSTRACT TRUNCATED AT 250 WORDS)

[Role of the uterus in human cyclic ovarian function]. / O roli matki v realizatsii tsiklicheskoi funktsii iaichnikov u cheloveka.

The ovarian function of 20 women with congenital uterine and vaginal aplasia was examined. Cyclic character of estradiol and progesterone secretion persisted in 19 patients. The concentration values of these hormones were within physiological norm in the majority of the women. Estradiol-estrone concentration ratio was lower than in the healthy subjects, showing a possible activation of estradiol metabolism in the uterus absence. The duration of the luteal hormone steroidogenic activity was the same as in the healthy women. Possible realization of the human reproductive system cyclic activity without the uterus is discussed.