Evaluation of renal cortical perfusion by noninvasive power Doppler ultrasound during vascular occlusion and reperfusion.

Background: Urine output, a frequently used resuscitation end point, is presumed to represent renal cortical perfusion. However, no noninvasive method for direct measurement of renal perfusion exists. Power Doppler ultrasound (PDUS) is a method that reportedly is sensitive to low-velocity and microvascular blood flow and can depict it.

Integra as a dermal replacement in a meshed composite skin graft in a rat model: a one-step operative procedure.

Background: Current use of Integra, the collagen-based dermal analogue, requires a two-step grafting procedure to achieve wound closure with an "ultrathin" autograft.

Methods: A one-step operative procedure of meshed composite skin graft (MCSG) using Integra as a dermal template for a meshed split thickness autograft was developed in rats. The silicon layer of Integra was removed, the resulting dermal analogue was meshed (1:1.

Direct current reduces accumulation of Evans Blue albumin in full-thickness burns.

Background: Application of direct current (DC) to a burn wound limits extension of the zone-of-stasis and reduces wound tissue edema.

Objective: To study the effects of DC on extravasation of plasma proteins after burn by using Evans blue (EB) as a marker of plasma albumin.

Materials And Methods: Male Sprague-Dawley rats with 20% total body surface area full-thickness scalds (100 degrees C/10 sec) were used as the experimental model.

Optimized mesh expansion of composite skin grafts in rats treated with direct current.

Background: The purpose of this study was to determine the optimum autoepidermal and allodermal expansion ratio of each component of a meshed composite skin graft (MCSG) that would lead to successful healing.

Methods: Male Sprague-Dawley rats were used as hosts of the MCSG and donors of autologous tissue. Male ACI rats were used as donors of allodermis.

Direct current reduces plasma protein extravasation after partial-thickness burn injury in rats.

Objective: To observe the effect of 40 microA direct current (DC) on plasma albumin extravasation after burn injury.

Design, Materials, And Methods: Silver-nylon wound dressings were used as anodes (-) on anesthetized male Sprague-Dawley rats with 20% total body surface partial-thickness scald burns. Burned rats with no treatment, or treated with silver-nylon dressing without current, were used as controls.

Direct current reduces wound edema after full-thickness burn injury in rats.

Objective: To observe the effect of 4 and 40 microA direct current (DC) on edema formation after burn injury in rats.

Design, Materials, And Methods: Silver-nylon wound dressings were used as either anodes (-) or cathodes (+) on 20% total body surface area full-thickness scalds in anesthetized male Sprague-Dawley rats. Untreated burned rats and rats treated with silver-nylon dressings without current were used as controls.

Enhanced survival of autoepidermal-allodermal composite grafts in allosensitized animals by use of silver-nylon dressings and direct current.

Objective: Observe the effect of silver-nylon (SN) dressing and direct electric current on healing of meshed autoepidermal/allodermal composite skin grafts (MCSGs) in allosensitized rats.

Materials And Methods: MCSGs were placed on experimental animals 28 to 30 days after placement of sensitizing allografts. MCSGs and control allografts were covered with either Vaseline gauze (VG) or SN; direct current, 40 microA, was applied for 5 days to some of the SN-dressed wounds (SNDCs).

The use of flow cytometry for the investigation of cell death.

Flow cytometry is more and more widely used for investigations of cell death, predominantly in the study of DNA degradation in cells dying by apoptosis. There are different interpretations of changes observed in DNA histograms of these cells. We describe an approach based on extraction of chromatin degradation products from fixed cells and subsequent staining with DNA specific dyes.

[The programmed cell death of murine BW5147 thymoma under the action of dexamethasone].

By flow cytometry, imitation modelling and biochemical analysis, the mode and kinetics of dexamethasone-treated T-lymphoma cell death were studied. The hormone was shown to induce delays in pre- and postsynthetic phases of the cell cycle and the death of part of cells. A short exposure to dexamethasone reveals its cytostatic rather than cytolytic effect.

[The combined action of gamma irradiation and hyperthermia on the structure of the cell population in the Chinese hamster].

A change in the structure of FAF-28 Chinese hamster cell population occurred during 24 h following gamma-irradiation or hyperthermia heating, or the effect of both factors was studied by flow cytofluorometry. With radiation delivered immediately after heating the distribution of cells among cycle phases was nearly the same as with hyperthermia alone: the share of cells at the S-phase was invariable during the first 4-6 h, then it slowly diminished; at G1 it slowly decreased and at G2 increased. When irradiation preceded heating the pattern of cell redistribution during the first hours was the same as that with radiation alone: the "wave" of transition from G1 to S phase was the same, but shorter in amplitude and longer in time; then cells were accumulated at G2+M and remained there for 24 h.

Apoptosis of murine BW 5147 thymoma cells induced by dexamethasone and gamma-irradiation.

The mode and the kinetics of the death of T-thymoma cells upon dexamethasone treatment and gamma-irradiation (10Gy) have been studied using flow cytometry and biochemical analysis. It has been shown that the hormone and gamma-irradiation induce cell death by apoptosis. In both cases the cells are initially blocked in G2/M and die only after overcoming the blockage and cytokinesis.

[D2O inhibition of interphase thymocyte death].

Using the method of flow cytometry and biochemical analysis it was shown that D2O, an agent that stabilizes microtubules, prevented the internucleosome fragmentation of DNA in thymocytes exposed to gamma radiation and dexamethasone in vitro. It was also found that D2O is ineffective with respect to Ca2+/Mg2(+)-dependent nuclease. The transfer of irradiated cells from a medium containing 90% of D2O to a normal one caused rapid DNA degradation; the fragmentation process ceased with the irradiated cells being transferred from H2O to heavy water.

[DNA replication in mammalian cells after the action of physical, chemical or biological factors. VI. The recovery of DNA synthesis in a culture of irradiated cells].

The kinetics of DNA synthesis restoration in cultured HeLa cells and in L-929 mouse fibroblasts irradiated by gamma-rays of 60Co with a dose of 10 Gy was studied. Early after irradiation the rate of DNA synthesis in HeLa cells measured with 3H-thymidine incorporation was seen to decrease. Two hours later the incorporation starts to increase to reach the control level 4 hours after irradiation and then becomes even higher than this level.

[Reproductive death of the apoptosis type in irradiated cells of the BW5147 thymoma].

The method of flow cytofluorometry and biochemical analysis were used to study the pattern and kinetics of the postirradiation death of proliferating BW5147 lymphoid cells. Irradiation with a dose of 10 Gy was shown to induce thymoma cell death by apoptosis. Radiation-induced synchronous transfer of part of cells from G1 to S-stage and blocking of all cells at G2/M stages of the cell cycle preceded the cell death.

[Analysis of distribution of S. cerevisiae cells for protein content using cell cycle models].

Histograms of cell distributions according to protein content obtained by means of flow cytofluorometry characterize the physiological state of the population as a whole and permit to calculate the velocity of protein accumulation in the cell in the course of the cell cycle. Dependence of population heterogeneity on culturing conditions is considered. Mathematical analysis of histograms of continuous cultures of S.

[General similarities and differences in the postradiation death of various animal species and of man].

It was found in various animal species and man that an ordered internucleosome fragmentation of DNA is characteristic of lymphoid cells dying in the interphase. Both in vivo and in vitro, the postirradiation DNA degradation in thymocytes of rodents and piglets preceded the increase in the permeability of their plasma membrane. The in vivo kinetics of death of lymphoid cells from the thymus and spleen is similar in rodents and piglets.

[The patterns of colchicine-induced death of lymphoid cells].

It is shown that colchicine injection at doses higher than 1 mg/kg of animal weight induces cell death in thymus, spleen, bone marrow and intestine mucosa. The cell death is accompanied by a regular internucleosomal cleavage of nuclear DNA and by the elimination of the formed fragments from cells. Both the processes begin after a 1.

[Interaction of the fluorescent probe diS-C3-(5) with lecithin-cholesterol membranes].

Behaviour of fluorescent carbocyanine probe disS-C3(5) in the egg lecithin-cholesterol membrane suspension was studied in relation to the lecithin/cholesterol ratio. The partition coefficient of the probe between aqueous and lipid phases decreases unlinearly with increase of cholesterol molar part in a bilayer. This parameter over molar part units was estimated to be (2.