Search Results

You are looking at 1 - 8 of 8 items for

  • Author: W. A. D. ANDERSON x
Clear All Modify Search
Free access

SAMUEL A. GUNN, THELMA CLARK GOULD and W. A. D. ANDERSON

Summary.

Between 24 and 40 hr after cadmium treatment in the rat, whilst the testis and caput epididymidis are undergoing haemorrhagic necrosis, the cauda epididymidis and contained spermatozoa remain morphologically normal. Sexual activity is diminished but fertile matings occur. By 7 days, reduced androgen output results in atrophic changes in the accessory glands, cauda epididymidis and vas deferens, in which spermatozoa are now degenerate. Few males mate and these are infertile. The changes in the cauda can be prevented by testosterone treatment and fertility remains normal up to 9 days after the dose of cadmium.

Free access

SAMUEL A. GUNN, THELMA CLARK GOULD and W. A. D. ANDERSON

Wetterdal (1958) showed that zinc, an element essential for spermatogenesis, is incorporated into developing spermatogenic elements within the testis. Cadmium, physico-chemically similar to zinc, causes selective destruction of the testis; administration of zinc prevents cadmium damage (Parizek, 1957; Kar, Das & Mukerji, 1960; Gunn, Gould & Anderson, 1961). Parizek (1960) suggested that cadmium exerts testicular injury by displacing zinc from its natural sites in seminiferous tubules and that the haemorrhagic reactions, so characteristic of cadmium injury, are a secondary effect. More recent evidence indicates that the vascular endothelium of the testis is the primary site of damage and that necrosis of parenchyma follows secondarily (Gunn, Gould & Anderson, 1963a; Chiquoine, 1964; Mason, Brown, Young & Nesbit, 1964; Niemi & Kormano, 1965; Waites & Setchell, 1966). The following experiments were initiated using radio-isotopes to determine

Free access

SAMUEL A. GUNN, THELMA CLARK GOULD and W. A. D. ANDERSON

Summary.

It is known that the selective injurious effect of cadmium on the testis can be prevented by zinc, cysteine or selenium. Studies, conducted in CD-1 mice, were initiated to determine whether any of these treatments offered protection by preventing cadmium from reaching the testis in doses sufficient to cause injury. Using cadmium chloride, labelled with 109Cd, it was shown that none of these protective agents decreased the amount of cadmium reaching the testis. Zinc acetate evoked no significant changes, cysteine brought about a slight enhancement of cadmium level but selenium dioxide produced a marked and prolonged elevation of cadmium uptake by the testis. Comparable studies in which selenium, rather than cadmium, was labelled (75Se) demonstrated that, in the presence of cadmium, selenium levels were augmented. Possible mechanisms are discussed to explain the diverse means of protection offered by zinc, cysteine and selenium. Since the site of cadmium-induced testicular injury has been pin-pointed at its vasculature, it is suggested that these protective agents exert their action at the vascular level.

Free access

SAMUEL A. GUNN, THELMA CLARK GOULD and W. A. D. ANDERSON

The observations of Pařízek & Zahor (1956) and Pařízek (1957a, b) on the selective destructive effect of cadmium on the testis of the rat and mouse have since been confirmed by Meek (1959), Kar & Das (1960), Gunn, Gould & Anderson (1961), Allanson & Deanesly (1962), Chiquoine (1964), Mason, Brown, Young & Nesbit (1964) and others. During studies on the induction of interstitial cell tumours of the testis by cadmium (Gunn, Gould & Anderson, 1963), we noted that cadmium failed to cause any degree of damage to the testis of the BALB/c mouse. A study was, therefore, undertaken to determine if this resistance to cadmium-induced testicular injury was unique to the BALB/c strain of mice and whether strain differences in testicular response to cadmium might also be observed in rats. A single subcutaneous (interscapular) injection of 0·03 m-mole/kg of CdCl2 was chosen for the preliminary testing since overwhelming testicular

Free access

S. A. Lampelo, T. L. Anderson and D. W. Bullock

Summary. Monoclonal antibodies against the cell surface were produced by immunizing mice with endometrial scrapings prepared from 6-day pregnant rabbits. Spleen cells from an immune mouse were fused with myeloma cells and cultured by standard hybridoma technology methods. Hybridoma supernatants were screened for reaction with the apical epithelial surface by immunohistochemistry on frozen sections of uterus from 6-day pregnant rabbits, and positive colonies were cloned by limiting dilution. Ascites fluid was produced in mice from hybridoma clones that gave a consistent pattern of apical epithelial surface staining through 6 sub-clonings. Antibodies in the ascites fluid were tested by immunohistochemistry on frozen sections of uterus, oviduct, lung, liver and kidney from nonpregnant or 6-day pregnant rabbits. At a dilution of 1:5000, the antibodies recognized an antigen that was specific to the apical surface of luminal but not glandular epithelium of the 6-day pregnant uterus and could not be detected in the nonpregnant uterine epithelium. At higher concentrations of antibody (1:100 to 1:1000), crossreaction was seen with antigens in stromal and myometrial cells of pregnant and nonpregnant uterus. At a dilution of 1:5000, the antibody also crossreacted with some components of lung, liver and kidney but without discriminating between the two reproductive states. In the oviduct, staining of the surface epithelium was specific to the pregnant state. We conclude that this monoclonal antibody has a high affinity for a luminal epithelial cell surface antigen in the reproductive tract of the pregnant rabbit and shows multiple organ reactivity with other tissues that is not affected by pregnancy. This antigen will provide a useful cell surface marker of epithelial differentiation in the progestational reproductive tract.

Free access

R A Anderson, W H B Wallace and D T Baird

Female fertility preservation provides significantly different challenges to that for the male, with the only established method being cryopreservation of embryos thus necessitating the involvement of a male. Other, experimental, options include oocyte or ovarian tissue cryopreservation. The latter has been regarded as a potential method for more than a decade, but has resulted in the birth of only five babies. It is not possible to be certain how many women have had ovarian tissue cryopreserved. Oocyte cryopreservation also remains experimental, but ∼100-fold more babies have been born through this technique over the last two decades. Ovarian tissue cryopreservation has the potential advantages of preservation of a large number of oocytes within primordial follicles, it does not require hormonal stimulation when time is short and indeed may be appropriate for the pre-pubertal. Disadvantages include the need for an invasive procedure, and the uncertain risk of ovarian contamination in haematological and other malignancies. We here review this approach in the context of our own experience of 36 women, highlighting issues of patient selection especially in the young, and uncertainties over the effects of cancer treatments on subsequent fertility. Of these 36 women, 11 have died but 5 have had spontaneous pregnancies. So far, none have requested reimplantation of their stored ovarian tissue. Ovarian cryopreservation appears to be a potentially valuable method for fertility preservation, but the indications and approaches best used remain unclear.

Free access

M. A. Jones, Z. -d. Cao, W. Anderson, C. Norris and M. J. K. Harper

Summary. Blastocysts recovered from control or indomethacin-treated (10 mg/kg s.c. twice daily starting on Day 4·5 of pregnancy) donor rabbits were transferred to the uteri of Day-6 or 6·5 pseudopregnant recipients. The minimal time required to cause an increase in capillary permeability in the endometrium underlying control blastocysts was ∼9 h. Blastocysts derived from the indomethacin-treated donors were depleted of PGE and PGF (determined by RIA) and were unable to produce any increase in capillary permeability during the same time period, although after 46 h in vivo the diameters of the implantation swellings related to control or indomethacin-treated blastocysts were not different. This suggests that, in the untreated recipients, blastocysts depleted of PGs can become replenished and then release these PGs in a site-directed manner. Indomethacin thus causes a delay rather than a complete inhibition of implantation. Incubation of the indomethacin-treated blastocysts in vitro led to replenishment with PGs, but such replenished blastocysts failed to induce an increase in capillary permeability within the same time-frame as control blastocysts. Evidence is presented that indomethacin is probably not the cyclooxygenase inhibitor of choice, since it interferes with PG uptake and efflux. Such an action could explain the failure of the replenished blastocysts to induce a normal increase in capillary permeability.

Free access

S Wilsher, F Stansfield, R E S Greenwood, P D Trethowan, R A Anderson, F B W Wooding and W R Allen

Gross, histological and immunocytochemical examinations carried out on maternal and fetal reproductive tissues from two pregnant giraffes at an estimated 8 and 13.5 months of gestation (term=15 months) revealed a typically ruminant macrocotyledonary placenta with binucleate trophoblast cells scattered sparsely in the placentome where they stained intensely with a prolactin antiserum. Binucleate cells were present in greater numbers in the intercotyledonary allantochorion where they did not stain for prolactin whereas the uninucleate trophoblast still did. A single large corpus luteum of pregnancy and several small luteinised follicles were present in the maternal ovaries while the fetal ovaries at 13.5 months gestation showed an assortment of enlarging antral follicles and partially and completely lutenised follicles, the granulosa and luteal cells of which stained positively for 3β-hydroxysteroid dehydrogenase (3β-HSD), 17,20 lyase, prolactin, progesterone receptor and androgen receptor, but negatively for aromatase. The uninucleate trophoblast of the placentome and intercotyledonary allantochorion, the epithelium of the maternal endometrial glands, the seminiferous epithelium in the fetal testis at 8 months of gestation and the zonae fasciculata and reticularis of the fetal adrenal at 13.5 months also stained positively for 3β-HSD and negatively for aromatase. Endocrinologically, it appears that the giraffe placenta is more similar to that of the sheep than the cow with a placental lactogen as the likely driver of the considerable degree of luteinisation seen in both the maternal and the fetal ovaries.