Therapeutic efficacy of differentiated versus undifferentiated mesenchymal stem cells in experimental type I diabetes in rat

Selective MSCs differentiation protocol into pancreatic beta cells was conducted in the present study using exendin-4 and TGF-beta. Differentiated and undifferentiated MSCs were assessed in experimental type I diabetes in rats. Ninety female white albino rats were included in the study and divided equally (n=15/group) into 6 groups: healthy control, healthy control rats received acellular tissue culture medium, diabetic rats, diabetic rats received acellular tissue culture medium, diabetic rats received undifferentiated MSCs and diabetic rats received differentiated MSCs. Therapeutic efficacy of undifferentiated versus differentiated MSCs was evaluated via assessment of quantitative gene expressions of insulin1, insulin 2, Smad-2, Smad-3, PDX-1, PAX-4, neuroD. Blood glucose and insulin hormone levels were also assessed. Results showed that quantitative gene expressions of all studied genes showed significant decrease in diabetic rat groups. Use of undifferentiated and differentiated MSCs led to a significant elevation of expression levels of all genes with more superior effect with differentiated MSCs except smad-2 gene. As regards insulin hormone levels, use of either undifferentiated or differentiated MSCs led to a significant elevation of its levels with more therapeutic effect with differentiated MSCs. Blood glucose levels were significantly decreased with both undifferentiated and differentiated MSCs in comparison to diabetic groups but its levels were normalized 2 months after injection of differentiated MSCs. In conclusion, use of undifferentiated or differentiated MSCs exhibited significant therapeutic potentials in experimental type I diabetes in rats with more significant therapeutic effect with the use of differentiated MSCs.     

No evidence for learned mating discrimination in male Drosophila pseudoobscura

Background  

Since females often pay a higher cost for heterospecific matings, mate discrimination and species recognition are driven primarily by female choice. In contrast, frequent indiscriminate matings are hypothesized to maximize male fitness. However, recent studies show that previously indiscriminate males (e.g., Drosophila melanogaster and Poecilia reticulata) can learn to avoid heterospecific courtship. This ability of males to discriminate against heterospecific courtship may be advantageous in populations where two species co-occur if courtship or mating is costly.     

A partially histocompatible family of Xenopus borealis

Reciprocal skin allografts were made between siblings of three successive generations in a family of Xenopus borealis and mutually tolerant animals were mated. In the F3 generation of one subfamily, 92% of the siblings were histocompatible.     

Dynamics of limiting cell wall porosity in plant suspension cultures

Changes in the limiting porosity of cell walls, i.e. the size limit for permeation of neutral molecules through the wall, were studied in several higher-plant cell-suspension cultures. For this purpose, samples of biomass fixed at different cultivation times were investigated using a method based on size-exclusion chromatography of polydisperse dextrans before and after equilibration with the extracted cell clusters. In suspension cultures of Chenopodium album L., Dioscorea deltoidea Wall. and Medicago sativa L., the mean size limit (MSL; critical Stokes' radius for exclusion of neutral polymers from half of the intracellular space) was found to vary between 2.4 and 3.8 nm. It decreased significantly during transition from the growth phase to the stationary phase. In the case of the C. album culture this change was found to be irrespective of whether sucrose in the medium was completely depleted at the end of the growth phase or not. The MSL was kept constant for long periods of the stationary phase if cell viability was maintained by repeated sucrose supplement. In a suspension strain of Triticum aestivum L., the MSL of cell wall permeation was comparatively small (1.75 nm) and remained constant during all cultivation phases. Relations between limiting porosity and cell wall growth, loss of pectic compounds to the medium, cross-linking activities and cell wall stiffening are discussed. Received: 19 December 1996 / Accepted: 23 April 1997     

Sensitivity of Rhizobium species to certain fungicides

Summary Thirty-three strains of different species of rhizobia were seeded into medium 79 agar. Discs impregnated with 3, 0.3, 0.03 and 0.003%, corresponding to 10, 1, 1/10 and 1/100 the recommended rate of application, of fungicides TMTD, Rhizoctole, Phygon, Ceresan and Orthocide 75 were placed on the seeded agar. After 120 hrs, zones of inhibition were measured. The 3, 0.3 and 0.03% concentrations of the five fungicides were inhibitory to most rhizobia tested in different degrees. The 0.003% level of these fungicides while toxic to certain strains, was not so for others.Deceased August 6, 1968.     

Natural immunity to grafts of FLD-3 erythroleukemia cells by irradiated mice

Mice were irradiated and infused with BALB/c Friend virus-induced FLD-3 erythroleukemia cells. Growth of the cells was estimated by measuring splenic incorporation of 5-iodo-2'-deoxyuridine-125I 5 days after cell transfer. BALB/cJ and C3H mice were 'poor responders' in that FLD-3 cells grew well in their spleens, while mice of other strains were 'good responders', resisting the growth of FLD-3 cells. No H-2 or Fv genetic locus was associated with resistance. Athymic nude mice and mice depleted of marrow tissue by 89Sr or estradiol resisted FLD-3 cells, indicating that the effectors were thymus- and marrow-independent. Silica, carrageenan and Propionibacterium acnes organisms all altered resistance, suggesting a function of macrophages. Neither interferon nor anti-interferon serum treatment altered resistance. Anti-asialo GM1 serum inhibited resistance to FLD-3 cells in vivo and inhibited natural cytotoxic (NC) activity against FLD-3 cells in vitro. NC (FLD-3) activity was greatly decreased in spleens 3 days after irradiation, in contrast with NK (YAC-1) and NC(WEHI-164.1) activities. Moreover, a 3-day delay in infusion of FLD-3 cells 'synergized' with silica in weakening genetic resistance in vivo. Thus, natural immunity to FLD-3 cells in vivo differs from that of genetic resistance to normal bone marrow cell allografts, and the lysis of FLD-3 cells in vitro seems to be mediated by cells which do not easily fit into the definition of natural killer (NK) or natural cytotoxic (NC) cells.     

Concurrent Demonstration of Desoxyribose nucleic Acid and 1,2-Glycols. 2. Periodate Oxidation

Formalin-fixed sections of rat intestine were treated in a solution of 0.5% periodic acid in 50% aqueous phosphoric acid for the concurrent demonstration of 1,2-glycols and DNA. The effects of varying the concentration of reagents, time of exposure and temperature on the results showed that, at 28°C, good reactions were obtained in 10-15 min when the concentration of the phosphoric was between 40 and 60% and that of the periodic acid between 0.05 and 0.50%.     

Alkaline Phosphatase Activity in Skin, as Shown by Staining En Bloc1

A modification of Gomori's method for alkaline phosphatase was applied to 5-7 mm cubes of fresh, unfixed human skin. Exposure to the substrate of buffered Na-β·glycerophosphate was varied from 8-36 hr, to the 2% Co(NO₃)₃, 2-12 hr; and to ammonium sulfide (containing approximately 1% NH₃), 1-2 hr. Optimum timing for these treatments were found to be 24, 4 and 1 hr, respectively. After staining, blocks were embedded in paraffin and serial sections were made. In such small blocks, the staining was uniform throughout the block. Alkaline phosphatase activity was seen in the walls of the subepidermal and periappendageal capillaries, as well as in the eccrine sweat glands, and did not differ from that seen in stained frozen sections. In particular, there was no loss of specificity and no diffusion of the enzyme.