Summer molting of bowhead whales Balaena mysticetus Linnaeus, 1758, of the Okhotsk Sea population.

In bowhead whales summering in Ulbanskiy Bay of the Okhotsk Sea, molting of epidermis has been found and histologically confirmed. The outer layer of the molting whale epidermis is longitudinally stratified and rejected in the form of relatively large plates up to several millimeters thick, each representing a lamellar formation consisting of longitudinal rows of parakeratocytes with degenerated nuclei, numerous pigment granules, and lipid inclusions. Molting intensity is correlated with the level of proliferation and regeneration of all epidermal layers, which helps to maintain the optimal skin thickness.

[Age-related peculiarities of thymus reaction to the exposure to helium-neon laser and injured muscle alloplasty with the muscle tissue from the animals of the same age].

Histological, cytological and morphometric changes in the thymus of 1 month-old, adult (3-4 months-old) and old (24-30 months-old) rats (24 animals in each group) were studied during muscle regeneration after the alloplasty of the injured area with the muscle tissue from the animal of the same age. Muscles of the donor or recipient were subjected to the course of preliminary irradiation with He-Ne laser (dose: 4.5-5.4 J/cm2 for each extremity; total dose of 9.0-10.8 J/cm2 per animal). It was shown that the exposure of gastrocnemius muscles that were prepared for the operation to He-Ne laser radiation decreased morpho-functional activity of the thymus in young, adult and old recipient rats the before surgery. This was demonstrated by its weaker reaction to the allograft during the early time intervals after surgery. The observed effect was more pronounced with the increasing age of an animal.

[Age peculiarities of the muscle regeneration after injury, exposure to he-ne laser and alloplasty with muscle tissue from the animal of the same age].

The recovery of the injured muscles were studied in young (aged 1 month), adult (aged 3-4 months) and old (aged 24-30 months) outbred male rats (24 animals in each group) after alloplasty of the injured area with the muscle tissue taken from the animal of the same age under the conditions of implantation of muscle tissue, non-irradiated by laser, into the area of injury of the muscle irradiated by laser (1st series) and vice versa, implantation of the muscle tissue irradiated by laser, into the area of injured non-irradiated muscle (2nd series). It is shown that in each age group in the 1st and the 2nd series, the allogeneic muscle tissue is is capable of regeneration. The regenerate mass s and the proportion of muscle tissue in them tended to be greater in the animals in the 1-series, as compared to those in the 2nd series. Alloplasty with the muscle tissue of the animal of the same age was more effective in young rats than in the old ones.

[Muscle regeneration and the state of the thymus in adult rats under laser irradiation and alloplasty of the gastrocnemius muscles and diaphragm of newborn rats].

The regeneration of gastrocnemius muscles of adult rats under implantation conditions in areas of muscle tissue damage in newborn rats has been studied. Alloplasty was performed using minced gastrocnemius and diaphragm muscles, which differs at birth in animals by degree of differentiation. The rat-recipient area of alloplasty was subjected to He-Ne laser radiation before operation, with the aim of reducing the immune response to allogenic muscle tissue. It has been shown that the number of regenerating myofibers produced in implanted gastrocnemius muscles is more than in alloplants from diaphragms. However, the formation of cartilage, bone, and adipose tissue foci were observed in the alloplastic region throughout the whole regeneration period. After implantation of minced diaphragm muscles, cartilage nodes were observed only in 7-day regenerates. At the end of observation, in the first instance, the area of muscle trauma in adult rat muscles was replaced by adipose tissue, even in the case of initial laser irradiation. During the implantation of diaphragm muscles, the area of trauma was filled with regenerating muscle tissue.

[Morphofunctional characteristics of the thymus and the muscle regenerating under laser irradiation and alloplasty of the adult muscle tissue in the trauma region].

The effect of muscle tissue alloplasty and He-Ne laser radiation on the skeletal muscle regeneration and thymus function was studied. Allogenic muscle tissue was implanted from an adult rat. Without laser irradiation (the first series of experiments), initial enhancement of thymus recovery observed on day 7 after alloplasty (a characteristic stress response to operation) was followed by gradual destructive changes in the thymus tissue. On day 30 after alloplasty, connective tissue developed in the implantation area in muscle regenerates, and the muscle tissue accounted for 64 +/- 2%. Implantation of unirradiated allografts into the muscles of recipient rats preirradiated with a He-Ne laser (the second series of experiments) resulted in a nearly complete destruction of the thymus and suppression of its function; the mitotic index of thymocytes was low. These changes were observed throughout the experiment starting immediately after the operation. In this case, the allogenic transplant retained the ability to develop: the 30-day repairing muscles consisted of 71 +/- 2% of muscle tissue. When an allograft preirradiated with a He-Ne laser was implanted into unirradiated rats (the third series of experiments), thymus destruction at the beginning of the postoperative period was much less significant than in the second series of experiments but more pronounced than in the first series. Then, thymus recovered more rapidly, the allogenic transplant was resorbed, and the muscle tissue in the regenerates accounted for 62 +/- 3%.

[Regenerative activity of muscle tissue and thymus status in young and old mdx mice with muscle injury and wound xenoplasty].

Responses of the skeletal muscle tissue and thymus to muscle injury (complete transection) and wound xenoplasty with the minced muscle tissue of newborn rats (tissue therapy) were studied in mdx mice aged 12-16 and 40-48 weeks. The muscle tissue of mdx mice has genetic defects causing chronic dystrophic processes in it. The muscle tissue of young mdx mice proved to retain a relatively high capacity for regeneration. Under conditions of tissue therapy of the wound, the formation of muscle fibers from muscle cells of the graft and active regeneration of muscle fibers in the recipient mice were observed, and no structural defects were detected in the thymus. The capacity of posttraumatic regeneration in old mdx mice was lower. The xenogenic graft was undergoing resorption, thereby suppressing regeneration of muscle fibers and causing further tissue destruction in the injured muscle. The thymus parenchyma was subject to degenerative changes such as the formation of gaps, hemorrhagic foci, and increased numbers of macrophages and mast cells.

[Structure peculiarities of muscle regenerates and state of thymus under He-Ne laser therapy in different periods after muscle trauma].

We studied the gastrocnemius muscle regeneration and the reactive changes in thymus of rats under different regimens of He-Ne laser therapy of both operated legs (632.8 nm; 2.5-3.0 mW/cm(2) ). Laser radiation (10 exposures by 3 min within 1-15 days after muscle trauma, 4.5-5.4 J/cm(2) total dose per each leg) stimulated inflammatory reaction, muscle healing and favored preservation of muscle tissue in regenerates. The changes in thymus mass, its histological structure, size of cortex and thymocite mitotic index pointed to the increase of the functional load on thymus and delay of its recovery. The same dose of laser therapy of muscles within 16-30 days after trauma led to the increase of muscle tissue sclerotization in regenerates. The reactive changes in thymus were less pronounced. Threefold decrease of laser dose (10 exposures by 1 min for 1-15 days, 1.5-1.8 J/cm(2)) suppressed inflammatory reaction, impaired the muscle regeneration. The increase of functional activity in thymus was not observed.

[Plasticity of allogenic muscle tissue transplanted into a traumatized rat muscle subjected He-Ne laser radiation].

The effect of muscle tissue alloplasty and laser radiation on the post-traumatic regeneration of skeletal muscles was studied. The implantation of an unirradiated minced allogenic muscle tissue into the area of trauma of a previously laser-irradiated muscle had a positive effect. The allogenic muscle tissue underwent active regeneration. The traumatized muscle fibers in the rat-recipient muscle grew into the alloplant. The implantation of a previously laser-irradiated muscle tissue into the area of trauma of an unirradiated muscle was less effective. The allogenic muscle tissue prevented the growth of rat-recipient myofibers and underwent lysis in general. The allotransplantation of a laser-irradiated muscle tissue into an x-irradiated (20 Gy) traumatized muscle increased the destruction of rat-recipient muscle tissue.

Regeneration of skeletal muscles and state of thymus in gamma-irradiated rats under laser therapy of the area of muscle trauma.

The gamma-irradiation of adult rats with a semi-lethal dose (6 Gy) suppressed the posttraumatic regeneration of skeletal muscles and brought about considerable destructive changes in the thymus. The effect of He-Ne laser radiation at a total dose 4.5-5.4 J/cm2 at each operated leg in irradiated rats stimulated the regenerative capacity of skeletal muscle tissue, the healing of skin-muscle wound, and the processes of postradiation recovery in thymus cells (a decrease of chromosome aberrations). The histological structure of regenerates had more muscle pattern. At the same time, the positive dynamics of regenerative processes in muscles was achieved by an increased functional load on the thymus. To stimulate the regeneration of irradiated muscles on the background of a more moderate load on the thymus, the prolonged period of laser therapy and fragmentary distribution of laser exposures during muscle regeneration were preferable. Wound healing improved visibly. Nor formation of chronic radiation ulcers on operated shins was observed.

Restoration of gastrocnemius muscle in MDX mice of different age after injury and implantation of xenogenic muscle tissue.

The intensity of regeneration of crossed gastrocnemius muscle was evaluated in two groups of mdx mice of different age 2 weeks after implantation of crushed muscle tissue from newborn rats into the wound defect area. The effect of xenoplasty manifested in increased weight of the damaged muscle. The effect was observed in mice aging 12-16 weeks but not in those aged 40-48-weeks. Structural changes in the skeletal muscle tissue intrinsic of mdx mice and augmenting with age were detected in intact mice before the experiment. Activity of muscle fiber regeneration in intact and injured muscle of 40-48-week-old mice was significantly lower than in 12-16-week-old ones. Myoblasts of the xenogenic transplant retained viability in recipient muscles for at least 2 weeks. posttraumatic regeneration was stimulated in only 12-16-week animals. Xenoplasty was ineffective in older animals and even somewhat enhanced the destructive processes in the muscle. It seems that age-specific regeneration activity of the recipient skeletal muscle tissue should be taken into consideration in the development of effective strategy of cell therapy for progressive muscular dystrophy.

[Regenerative capacity of muscle tissue and thymus state in irradiated rats exposed to long-term He-Ne laser radiation]. / Regeneratsionnaia sposobnost' myshechnoi tkani i sostoianie timusa u obluchennykh krys v usloviiakh prolongirovannogo vozdeistviia izlucheniia gelii-neonovogo lazera.

We studied the effect of He-Ne laser on regeneration of damaged gastrocnemius muscle in rats irradiated at 6 Gy in conditions of fractional laser energy spread (10 exposures, 3 min for each limb, within 30 days after the operation; 2-3 exposures weekly; 2.5-3.0 mW/cm2 power density; and 9.0-10.8 J/cm2 total dose per animal). Laser radiation stimulated regenerative activity of the skeletal muscle and favored a more even distribution of load on the thymus (a smooth decrease in its weight and slow aplasia). The level of chromosomal aberrations in the thymocytes demonstrated certain instability although remained lower as compared to the control during the whole observation period (60 days).

[Regenerative activity of muscle allografts and thymus status during long-term laser exposure of adrenals and homoplasty region prior to transplantation]. / Regeneratsionnaia aktivnost' myshechnykh gomotransplantov i sostoianie timusa v usloviiakh prodolzhitel'nogo lazernogo vozdeistviia na nadpochechniki i oblast' gomoplastiki do operatsii.

Cross allografting of both gastrocnemius muscles between intact rats and those with the adrenal and right shin preirradiated with a He-Ne laser (632.8 nm, 2.5-3.0 mW/cm2, 10 sessions within 14 days with the cumulative dose being 15-18 J/cm2 per rat). By the time of grafting, the adrenal activity decreased while the activity of thymus decreased. As a result, the allogenic muscle tissue was resorbed in the irradiated rats, particularly, in the right irradiated shin. At the same time, reinnervation of the grafts with a certain amount of survived allogenic muscle tissue was more active in the right irradiated shin as compared to the left intact one. Survival of the donor muscle tissue and its improved reinnervation was observed in a higher proportion of grafts in the intact rats. The allografts from the right preirradiated shin of animals with irradiated adrenal proved to be more viable as compared to the left intact shin.

[Structure and functions of muscle allotransplants developing in adrenals and the alloplasty area after long-term exposure]. / Struktura i funktsiia myshechnykh gomotransplantatov, razvivaiushchikhsia posle prodolzhitel'nogo deistviia lazernogo izlucheniia na nadpochechniki i oblast' gomoplastiki.

The cross allotransplantation of right gastrocnemius muscles was carried out between intact rats and rats in which adrenals and right shins were subjected to low-energy He-Ne laser radiation (10 procedures for 2 weeks, the exposure duration 5 min; total dose for each rat 15-18 J/cm2). By conditions of experiment, the rats in each series were both donors and recipients, and hence the heterogeneity of rats in each series was the same. It was shown that the laser radiation in the dose studied and the regimes of exposure of rat adrenals and shin (area of the planned allotransplantation) influenced the muscle alloplasty. In rats with irradiated adrenals and shin, the disintegration and resorption of muscle allografts occurred more actively. In intact rats, muscle allografts were more viable. The allogenic muscle tissue and a weak contractile reaction of allografts were revealed in most of them. The allografts showed a moderate lymphocytic infiltration. The data obtained indirectly evidence that the transplant immune reaction increased in rats with irradiated adrenals and shin. In intact rats, the transplant immune reaction to irradiated m.gastrocnemius from irradiated shin decreased.

[Histogenetic, metabolic, and immunologic aspects of the effect of infrared laser radiation on injured skeletal muscles from irradiated and nonirradiated rats]. / Gistogeneticheskie, metabolicheskie i immunologicheskie aspekty deistviia infrakrasnogo lazernogo izlucheniia na travmirovannuiu obluchennuiu skeletnuiu myshtsu krys.

Using biochemical, histological, morphometric and cytogenetic methods, it was shown that low-intensive infrared laser radiation (total dose 3.6 J/cm2), applied to the injured rat skeletal muscles, stimulated metabolism and regeneration more efficiently in the muscles locally exposed to 20 Gy X-rays compared to the unexposed muscles. The laser irradiation promoted postradiative recovery in bone marrow cells, but did not provide normalization in thymus lymphocyte activity.

[Regeneration of gastrocnemius muscle and state of immune system in radiated rats under the influence of He-Ne laser]. / Regeneratsiia ikronozhnykh myshts i sostoianie immunnoi sistemy u obluchennykh krys pri vozdeistvii luchei gelii-neonovogo lazera.

We studied the influence of a low-energy He-Ne laser on the regeneration of the transected gastrocnemius muscle and state of the thymus and bone marrow in adult mongrel rats irradiated at 6 Gy using the histological, morphometric, and cytogenetic methods. The laser influence on both rat hind limbs (at total doses of 9.0-10.8 J/cm2) during the first 14 days after transection enhanced the regenerative capacity of the skeletal muscle traumatized as a result of irradiation, and reduced cytogenetic damage in the bone marrow and thymus cells. The changes in the thymus mass and histology suggest that the functional load on the thymus increased under the experimental conditions.

[Structural and functional characteristics of muscle allotransplants, formed under different conditions of laser irradiation]. / Strukturnye i funktsional'nye osobennosti myshechnykh gomotransplantatov, razvivaiushchikhsia v razlichnykh usloviiakh lazernogo oblucheniia.

It is known that a low-energy laser radiation can cause reflex suppression of immunity. The present experiments were designed to determine the plastic activity of allogenic muscle tissue in different conditions of a previous action of laser rays. The cross homotransplantation of gastrocnemius muscles was carried out between intact rats, or between rats in which 14 days before transplantation each hind leg was subjected to low-energy He-Ne laser radiation in dose of 7.5-9 J/cm2 (10 procedures, the duration of each exposure was equal to 5 min), or between intact and radiated rats. It was shown that the donor muscle tissue survived longer when a nonradiated muscle was transplanted into the radiated muscle bed. The axons grew into the donor muscle tissue. More allogenic muscle tissue was involved in contractile reaction when stimulation was carried out via the nerve. Laser radiation of a homotransplant alone, or that of a homotransplant and a muscle bed in the recipient was less effective. So, He-Ne laser radiation of the area of a planned allotransplantation decreased the transplant immunity response and favoured a longer development of allogenic muscle tissue. The viability of donor muscle tissue therewith increased, if the muscle allograft had not been subjected to a previous laser radiation.

[Experimental study of the effect of pulsed infrared laser radiation on skeletal muscle regeneration after mechanical trauma]. / Eksperimental'noe izuchenie vliianiia impul'snogo infrakrasnogo lazernogo izlucheniia na regeneratsiiu skeletnoi myshtsy posle mekhanicheskoi travmy.

Impulse infrared laser radiation (0.89 microm) was examined for effect on regeneration of cross-cut musculus gastrocnemius in adult rats (ten 3-min exposures, 2-3 procedures weekly for one month after the operation, modulating frequency 10 Hz, total course dose 3.6 J/cm2). Histological, morphometric and biochemical parameters of muscular regenerates as well as biochemical serum indices show enhanced regeneration of the skeletal muscle. Formation of the muscular organ ends earlier vs untreated muscles. This was accompanied with more active sclerotization of the muscular regenerate.