Social organization of confined male collared lemmings (Dicrostonyx groenlandicus Traill)

This study describes and quantifies the social organization and agonistic behaviour of adult male collared lemmings (Dicrostonyx groenlandicus) in an indoor enclosure. Five groups of four lemmings were observed during separate 8-day tests. Experimental design permitted an increase in group size while density remained constant. When in groups of two, males established stable dominant-subordinate relationships and, when in groups of four, they formed stable non-linear dominance hierarchies. For either group size, frequency of agonistic behaviour declined over time. Habituation, formation of dominance relationships and spatio-temporal partitioning of space are suggested as possible explanations of this decline. Percentage of initial body weight lost during the experiments varied inversely with social rank. Possible causes of this weight loss are discussed. Social relationships in this study are discussed in light of field observations of male lemming home range distribution.     

Isolation of albumin from whole human plasma and fractionation of albumin-depleted plasma.

The dye Cibacron Blue F-3-GA was conjugated to Sepharose to provide an affinity column for serum albumin. Passage of whole human plasma through a column of Cibacron Blue-Sepharose results in the removal of approx. 98% of the albumin. The latter can be quantitatively recovered by desorption with NaSCN. Albumin-depleted plasma can be readily resolved into discrete fractions by a combination of conventional biochemical techniques. In particular, the resolution of plasma proteins with properties similar to those of native human plasma albumin can readily be accomplished by ion-exchange chromatography of the Sepharose-dye-treated plasma on DEAE-cellulose.     

An X-ray microanalytical azo dye technique for the localization of acid phosphatase activity

Summary A new method is described for the histochemical localization of acid phosphatase. Naphthol AS BI, enzymatically released from naphthyl AS BI phosphoric acid, is coupled with diazotized 2,5-dibromoaniline to produce a fine insoluble red azo dye. The histochemical and cytochemical localization of this final reaction product in rat liver is described. In the electron microscope, sites of the azo dye can be detected by X-ray microanalysis of ultrathin cryosections of reactive tissue.This research was supported by Scientific Research Council Grant No. B/RG/67527     

Studies on the ovotestis of the slug Agriolimax reticulatus (Müller)

Summary The ovarian oocytes of Agriolimax reticulatus (Müller) have been studied by light and electron microscopy and electron cytochemistry. The development of the oocyte in the ovotestis may be divided into three stages.During Stage I the oocyte cytoplasm contains mainly ribosomes and also strands of endoplasmic reticulum, scattered mitochondria and Golgi systems. The nucleus contains both a paranucleolus and an eunucleolus. By Stage II the oocyte has enlarged, especially in a plane parallel to the basement membrane. In addition to the above mentioned organelles, the cytoplasm contains lipid, glycogen and early yolk platelets. During Stage III, the oocyte continues to enlarge, but mainly in a plane perpendicular to the basement membrane. A considerable degree of cytoplasmic differentiation has also taken place. The plasma membrane of the oocyte has become specialized with the appearance of a polysaccharide-rich glycocalyx, microvilli and pinocytotic tubules. Elsewhere, much of the background cytoplasm, containing Golgi-derived, polysaccharide and acid phosphatase-rich multivesiculate bodies, lipid and glycogen, is sequestered by smooth membranes and ultimately fuses with the growing yolk platelets. The nucleus contains an amphinucleolus, characteristic of many gastropods.The findings of this study are discussed in relation to results from other studies on oogenesis.     

Rat Sertoli cells in culture undergo metabolic co-operation with each other and with fibroblasts

Metabolic co-operation between Sertoli cells from adult rats was detected by adding one group of cells, which were the recipients, to a second group of cells, which had been labelled for 3 h with [3H]uridine and were the donors. Metabolic co-operation also was studied by co-culturing Sertoli cells, which were the donors, with human or Chinese hamster HGPRT- fibroblasts (recipients) in the presence of [3H]hypoxanthine. With both techniques the recipients in contact with donors had significantly more radioactive grains than did the recipients alone. In all cases the proportion of interactions that were positive for metabolic co-operation was greater than 80%.     

The fine structure of the planarianPolycelis tenuis ijima

Summary The fine structure of the pharynx is presented and demonstrates that the pharyngeal epithelial system is a continuous one. The epithelial lining of the pharyngeal cavity with its characteristic fibrous secretory bodies merges with the outer pharyngeal epithelium at the point of anchorage of the pharynx. A few of these cells are insunk, the nuclei occurring beneath the underlying muscular layers. The nature of the outer epithelium changes towards the free end of the pharynx; the cells become ciliated and in contents come to resemble the inner epithelium which it joins at the tip.The gut cells merge at a transitional zone with the inner pharyngeal epithelium and at this point both bear microvilli and contain rod-shaped apical bodies. Some of these cells are also insunk. Towards the mouth the epithelium shows a greater degree of insinking and exhibits microapocrine secretion. Both inner and outer epithelia bear sense receptors which are concentrated at the lip.At the point of pharyngeal insertion, the sub-epithelial tissue resembles planarian parenchyma, but is rich in gland cells. These glands open on to the outer epithelium especially towards the free end of the pharynx.This research was supported by the Scientific Research Council. Grant No. B/RG/086.     

A case of Ebola virus infection.

In November 1976 an investigator at the Microbiological Research Establishment accidentally inoculated himself while processing material from patients in Africa who had been suffering from a haemorrhagic fever of unknown cause. He developed an illness closely resembling Marburg disease, and a virus was isolated from his blood that resembled Marburg virus but was distinct serologically. The course of the illness was mild and may have been modified by treatment with human interferon and convalescent serum. Convalescence was protracted; there was evidence of bone-marrow depression and virus was excreted in low titre for some weeks. Recovery was complete. Infection was contained by barrier-nursing techniques using a negative-pressure plastic isolator and infection did not spread to attendant staff or to the community.     

Hypoxia‐induced miR‐3677‐3p promotes the proliferation,migration and invasion of hepatocellular carcinoma cells by suppressing SIRT5

Hepatocellular carcinoma (HCC), with life‐threatening malignant behaviours, often develops distant metastases and is the fourth most common primary cancer in the world, having taken millions of lives in Asian countries such as China. The novel miR‐3677‐3p is involved in a high‐expression‐related poor prognosis in HCC tissues and cell lines, indicating oncogenesis functions in vitro and in vivo. Initially, we confirmed the inhibition of proliferation, migration and invasion in miR‐3677‐3p knock‐down MHCC‐97H and SMMC‐7721 cell lines, which are well known for their high degree of invasiveness. Then, we reversed the functional experiments in the low‐miR‐3677‐3p‐expression Hep3B cell line via overexpressing miR‐3677‐3p. In nude mice xenograft and lung metastasis assays, we found suppressor behaviours, smaller nodules and low density of organ spread, after injection of cells transfected with shRNA‐miR‐3677‐3p. A combination of databases (Starbase, TargetScan and MiRgator) illustrated miR‐3677‐3p targets, and it was shown to suppress the expression of SIRT5 in a dual‐luciferase reporter system. To clarify the conclusions of previous ambiguous research, we up‐regulated SIRT5 in Hep3B cells, and rescue tests were established for confirmation that miR‐3677‐3p suppresses SIRT5 to enhance the migration and invasion of HCC. Interestingly, we discovered hypoxia‐induced miR‐3677‐3p up‐regulation benefited HCC malignancy and invasiveness. In conclusion, the overexpression of miR‐3677‐3p mediated SIRT5 inhibition, which could increase proliferation, migration and invasion of HCC in hypoxic microenvironments.