The usefulness of alkaline solutions for clearing the uterus and staining implantation sites in rats

The alkaline solution method for detecting uterine implantation sites (metrial glands or spots after delivery), which indicate the position of the embryo, was compared with conventional methods using Turnbull blue (Salewski's technique) and benzyl benzoate (Orsini's technique) in rats. When rat uteri were immersed directly in 2% sodium hydroxide [NaOH], potassium hydroxide [KOH] solution or one of several other alkaline solutions for one hour, the uteri were cleared. Then the metrial glands could be observed without further staining, and the spots after delivery with further staining. After alkaline treatment, unstained metrial glands appeared as yellowish-white degenerated masses and stained spots after delivery appeared as yellowish-brown patches covered with yellowish-white lumps. These yellowish-brown or yellowish-white sites were probably stained by the iron in hemosiderin deposits in the placental scar or in a vestige of the metrial glands left over from pregnancy. Formalin-fixed uteri were not cleared by immersion in a high concentration of NaOH, KOH or other alkaline solutions, but the spots after delivery were stained by this treatment. Turnbull blue did not stain the metrial glands, which contain no iron. Benzyl benzoate cleared fixed or unfixed uteri and allowed observation of the metrial glands and spots after delivery although the entire process required a few days and the specimens became hard and shriveled. The best and most convenient solution for clearing the rat uterus and for staining implantation sites was 2% NaOH or KOH.     

Active Oxygen Contributes to the Major Part of Chromosomal Aberrations in V79 Chinese Hamster Cells Exposed to N-Hydroxy-2-Naphthylamine

N-hydroxy-2-naphthylamine (NOH-2NA). an active metabolite of human occupational bladder carcinogens, induced, in V79 Chinese hamster cells. chromosomal aberrations which were suppressed in the presence of catalase and/or superoxide dismutase. The induction of the aberrations was more efficient in a more basic pH in parallel with the generation of hydrogen peroxide from NOH-2NA. The possible role of the oxidation product of NOH-2NA in the induction of the aberrations is discussed.     

Kinetics of the Unrolling of the Second Leaves Detached from Rice Seedlings by Blue Light

Unrolling due to blue light (B) irradiation of the second leavesdetached from 8-day-old rice (Oryza saliva L.) seedlings wassimilar to that reported previously for nondetached leaves.The effect of B was counteracted by irradiation with red light(R). The counteracting effect of R was reversed by subsequentirradiation with far-red light (FR). When the detached leaf was irradiated with B passed througha 1-mm-wide slit 5, 8, 10, 12 or 15 mm from the leaf tip, irradiation10 mm from the leaf tip was the most effective. The effect of a 1 mm-wide-B irradiation 10 mm from the leaftip was counteracted by a 1 mm-wide-R irradiation at the sameposition, but not by irradiations at the other points. The counteractingeffect of R was reversed by a 1 mm-wide-FR irradiation at thesame position. This suggests that the excitation or the reactionof the B photoreceptor(s) is affected directly by the PFR formof phytochrome. The dose-response curve for the unrolling caused by B showeda simple Bunsen-Roscoe relation without two peaks, which differsfrom that for the phototropism in Avena caused by B. (Received August 21, 1980; Accepted December 20, 1980)     

Phosphate permeability in cells ofChlorella ellipsoidea

Summary Active transport of orthophosphate byChlorella ellipsoidea was observed at 25 °C under fluorescent light, about 3 klux. Influx and efflux of phosphate, and extra- and intracellular phosphate concentrations were measured in order to assess phosphate permeability in the cells. The permeability ranged from 10^–3 to 10^–4 mlQ/mg cell min (or 10^–7 to 10^–8cm/sec).     

Peptides of type II collagen can induce the cleavage of type II collagen and aggrecan in articular cartilage.

The objective of this study was to determine whether a fragment(s) of type II collagen can induce cartilage degradation. Fragments generated by cyanogen bromide (CB) cleavage of purified bovine type II collagen were separated by HPLC. These fragments together with selected overlapping synthetic peptides were first analysed for their capacity to induce cleavage of type II collagen by collagenases in chondrocyte and explant cultures of healthy adult bovine articular cartilage. Collagen cleavage was measured by immunoassay and degradation of proteoglycan (mainly aggrecan) was determined by analysis of cleavage products of core protein by Western blotting. Gene expression of matrix metalloproteinases MMP-13 and MMP-1 was measured using Real-time PCR. Induction of denaturation of type II collagen in situ in cartilage matrix with exposure of the CB domain was identified with a polyclonal and monoclonal antibodies that only react with this domain in denatured but not native type II collagen. As well as the mixture of CB fragments and peptide CB12, a single synthetic peptide CB12-II (residues 195-218), but not synthetic peptide CB12-IV (residues 231-254), potently and consistently induced in explant cultures at 10 microM and 25 microM, in a time, cell and dose dependent manner, collagenase-induced cleavage of type II collagen accompanied by upregulation of MMP-13 expression but not MMP-1. In isolated chondrocyte cultures CB12-II induced very limited upregulation of MMP-13 as well as MMP-1 expression. Although this was accompanied by concomitant induction of cleavage of type II collagen by collagenases, this was not associated by aggrecan cleavage. Peptide CB12-IV, which had no effect on collagen cleavage, clearly induced aggrecanase specific cleavage of the core protein of this proteoglycan. Thus these events involving matrix molecule cleavage can importantly occur independently of each other, contrary to popular belief. Denaturation of type II collagen with exposure of the CB12-II domain was also shown to be much increased in osteoarthritic human cartilage compared to non-arthritic cartilage. These observations reveal that peptides of type II collagen, to which there is increased exposure in osteoarthritic cartilage, can when present in sufficient concentration induce cleavage of type II collagen (CB12-II) and aggrecan (CB12-IV) accompanied by increased expression of collagenases. Such increased concentrations of denatured collagen are present in adult and osteoarthritic cartilages and the exposure of chondrocytes to the sequences they encode, either in soluble or more likely insoluble form, may therefore play a role in the excessive resorption of matrix molecules that is seen in arthritis and development.     

The sweet and bitter sides of galectins in melanoma progression

Melanoma is the leading cause of skin cancer-related deaths, which is due in large part to its aggressive behavior, resistance to therapy, and ability to metastasize to multiple organs such as the lymph nodes, lung, and brain. Melanoma progresses in a stepwise manner from the benign nevus, to radial spreading through the dermis, to a vertical invasive phase, and finally to metastasis. The carbohydrate-binding family of galectins has a strong influence on each phase of melanoma progression through their effects on immune surveillance, angiogenesis, cell migration, tumor cell adhesion, and the cellular response to chemotherapy. Galectins share significant homology in their carbohydrate recognition domain (CRD), which mediates binding to an array of N-glycosylated proteins located on the surface of tumor cells, endothelial cells, T-cells, and to similarly glycosylated extracellular matrix proteins. Galectins are also present within tumor cells where they perform anti-apoptotic functions and enhance intracellular signaling that results in deregulated expression of genes involved in tumor progression. The most extensively studied galectins, galectin-1 and galectin-3, have been shown to have profound effects on melanoma growth and metastasis by influencing many of these biological processes.