Showing papers in "Immunology and Cell Biology in 1986"
TL;DR: Neither the removal of mesenteric lymph nodes nor removal of the ileum had any statistically significant effect on the total output of cells or on the population of IgA-producing cells in lymph draining from the gut.
Abstract: THE ROLE OF GUT-ASSOCIATED LYMPHOID TISSUES IN THE GENERATION OF IMMUNOGLOBULIN-BEARING LYMPHOCYTES IN SHEEP
84 citations
TL;DR: Darlington atmospheric pressure, an index of the Southern Oscillation, was found to be well below average during the autumn, winter and spring preceding the occurrence of Murray Valley Encephalitis, suggesting that this relationship can be used to provide a simple, objective early warning system.
Abstract: A METHOD FOR PREDICTING MURRAY VALLEY ENCEPHALITIS IN SOUTHEAST AUSTRALIA USING THE SOUTHERN OSCILLATION
68 citations
TL;DR: The prevalence of antibodies in human sera from the south coast of New South Wales to four arboviruses, isolated from mosquitoes collected along theSouth coast, was determined in an attempt to estimate the importance of these viruses in human infection.
Abstract: The prevalence of antibodies in human sera from the south coast of New South Wales to four arboviruses, isolated from mosquitoes collected along the south coast, was determined in an attempt to estimate the importance of these viruses in human infection. Only two viruses, Barmah Forest and Gan Gan, were considered to be of any significance.
42 citations
TL;DR: High post-operative morbidity and mortality in the pancreatectomised animals made this method of inducing diabetes unsuitable for animals to be used in long term studies, but the good clinical state of animals after streptozotocin and the permanence of their diabetes indicated that these animals were suitable for longterm studies such as those involving transplantation of pancreatic islet tissue.
Abstract: Insulin-dependent diabetes mellitus was induced in the pig by pancreatectomy or by administration of intravenous streptozotocin (150 mg/kg). High post-operative morbidity and mortality in the pancreatectomised animals made this method of inducing diabetes unsuitable for animals to be used in long term studies. By contrast, the good clinical state of animals after streptozotocin and the permanence of their diabetes indicated that these animals were suitable for long term studies such as those involving transplantation of pancreatic islet tissue. Techniques designed to facilitate the assessment and management of these animals included placement of an indwelling jugular venous catheter to enable blood samples to be obtained for metabolic studies, denervation of an area on the flank of the animal to enable insulin administration with minimum discomfort and denervation of an ear to enable blood samples to be obtained from the animal for glucose estimation in long term studies.
39 citations
TL;DR: Aminoglutethimide, which inhibits overall steroid synthesis as well as aromatase, reduced the albumin space in both control and hCG-injected rats but the hCG response, as judged by the ratio between treated and control rats, was unaffected.
Abstract: THE INCREASE IN TESTICULAR VASCULAR PERMEABILTY INDUCED BY HUMAN CHORIONIC GONADOTROPHIN INVOLVES 5-HYDROXYTRYPTAMINE AND POSSIBLY OESTROGENS, BUT NOT TESTOSTERONE, PROSTAGLANDINS, HISTAMINE OR BRADYKININ
38 citations
TL;DR: Aedes camptorhynchus (Thom.) collected on the mid-south coast of New South Wales during the winter of 1982 were highly susceptible to infection when fed on rat tail skins containing blood and serial dilutions of the T48 strain of Ross River (RR) virus.
Abstract: Aedes camptorhynchus (Thom.) collected on the mid-south coast of New South Wales during the winter of 1982 were highly susceptible to infection (ID50 = 10(2.4) VERO pfu/mosquito) when fed on rat tail skins containing blood and serial dilutions of the T48 strain of Ross River (RR) virus. After 2 d, when no virus was detectable, rapid proliferation allowed transmission from 5 d post ingestion. A maximum transmission rate occurred 9 d post-feeding when 4 of 4 infected mosquitoes transmitted virus. The susceptibility of Ae camptorhynchus to RR virus infection was compared with that of a laboratory colony of Ae aegypti (L.) (ID50 = 10(3.8) VERO pfu/mosquito).
38 citations
TL;DR: Electrophoretic mobility patterns of four enzymes of Giardia lamblia strains studied could be grouped into three different isoenzyme types (Zymodemes), where ME mobility was identical in all the four strains, and some relative difference was seen in the mobility of GPI.
Abstract: Strains of Giardia lamblia were isolated from symptomatic cases of giardiasis and axenized in the laboratory. Electrophoretic mobility patterns of four enzymes, viz., EC 5.3.1.9 glucose phosphate isomerase (GPI); EC 1.1.1,4.0.L-malate; NADP+ Oxidoreductase (Oxaloacetate decarboxylating) (ME); EC 2.7.5.1 phosphoglucomutase (PGM); and EC 2.7.1.1 hexokinase (HK) of the lysates prepared from these isolates were studied using starch-gel. Based on differences in mobility patterns of PGM and HK, the four strains studied could be grouped into three different isoenzyme types (Zymodemes). ME mobility was identical in all the four strains. Some relative difference was seen in the mobility of GPI, though the pattern of mobility was similar in all the strains.
35 citations
TL;DR: Quantitative hybridization studies with DNA from uninfected mice and DNA extracted from oocysts of the ME49 strain of T. gondii confirmed that RH strain DNA could be obtained at least 90% pure with a high recovery.
Abstract: Toxoplasma gondii DNA from RH strain tachyzoites was purified from contaminating murine DNA by isopycnic density gradient ultracentrifugation in CsCl containing the fluorescent dye Hoechst 33258. Quantitative hybridization studies with DNA from uninfected mice and DNA extracted from oocysts of the ME49 strain of T. gondii confirmed that RH strain DNA could be obtained at least 90% pure with a high recovery. Preliminary characterization studies on such purified DNA showed that it had a G + C content of 50% and was not significantly methylated.
33 citations
TL;DR: The data suggest that the evolution of MVE in Australia and PNG has proceeded independently and that circulating Australian MVE strains are not systematically re-seeded from regions of endemicity in PNG.
Abstract: The genetic relatedness of ten Murray Valley encephalitis virus (MVE) isolates from Australia has been examined by comparing HaeIII and TaqI restriction digest profiles of cDNA to virion RNA. The isolates were from the Murray Valley region of south-eastern Australia and from the Ord River region of Western Australia and spanned a period of 23 years (1951-1974). The isolates generated closely similar restriction digest profiles. The extent of similarity suggested that the level of nucleotide sequence divergence between any pair of Australian MVE isolates is probably around 1%. The genetic homogeneity of the MVE isolates contrasts with results obtained for Ross River virus, an alphavirus, using an identical methodological approach; we propose that this difference results from the important role of birds in the life cycle of MVE. Four MVE isolates from three fatal human cases showed small genetic differences one from the other. These isolates did not have a common restriction digest profile which distinguished them from strains obtained from other sources (e.g., from mosquitoes or a heron). The data do not support the view that clinical cases of MVE infection in humans are due to a particular strain of virus although this has not been rigorously excluded. The two available MVE isolates from Papua New Guinea (PNG) were from the Sepik and Port Moresby regions. They generated HaeIII and TaqI restriction digest profiles which were different both from each other and from those of the Australian type. Genetic divergence between the two PNG isolates was estimated to be approximately 6%; divergence between either of the PNG isolates and the Australian type was greater than 6%. Our data suggest that the evolution of MVE in Australia and PNG has proceeded independently and that circulating Australian MVE strains are not systematically re-seeded from regions of endemicity in PNG. Studies on the relatedness of MVE and two close antigenic relatives, Japanese encephalitis virus (JE) and Alfuy virus (ALF), showed that the genetic relatedness between any MVE isolate and JE or ALF is less than that between the most divergent of the MVE isolates, including those from Papua New Guinea.
32 citations
TL;DR: Two staphylococcal plasmids encode production of a diffusible pigment and resistance to erythromycin and spectinomycin, and behave as hitch-hiking transposons in cultural conditions that favour phage-mediated or ph age-independent conjugation.
Abstract: Two staphylococcal plasmids, pWG4 and pWG25, encode production of a diffusible pigment and resistance to erythromycin and spectinomycin. The former was found occurring naturally in a clinical isolate of Staphylococcus aureus and the latter in S. epidermidis. Both plasmids are conjugative, capable of high-frequency, interspecies transfer, only isolated in the open-circular form and identical in molecular weight and pattern of restriction-endonuclease fragments. The only difference between the plasmids is in the expression of resistance, pWG4 encoding inducible and pWG25 constitutive erythromycin resistance. The resistance determinants of both plasmids behave as hitch-hiking transposons in cultural conditions that favour phage-mediated or phage-independent conjugation, always inserting a copy of themselves into the recipient's chromosome, except in S. epidermidis in which the chromosomal insertion site may be absent. The resistance determinants have been cloned and located on a 4 X 7 kbp EcoR1/HindIII restriction fragment which has a restriction map similar to that of the right arm of Tn554 (Murphy and Lofdahl, 1984). The hitch-hiking transposon of plasmid pWG25 has been designated Tn3853.
32 citations
TL;DR: An animal model may now be established to study aspects of Hepadna virus infection which are pertinent to Hepatitis B virus (HBV) disease in man.
Abstract: Natural Duck Hepatitis B Virus (DHBV) infection has been studied in Australian ducks. Sera from 430 Pekin Aylesbury cross-bred ducks taken from three separate flocks were examined for duck hepatitis B virus (DHBV) DNA using a DNA dot hybridisation assay. In one flock there was significant infection with DHBV (98/140), but none was detectable in the other two flocks. Episomal DHBV DNA in liver tissue was demonstrated by gel blot hybridisation only in birds with DHBV DNA in serum. Polymerase-labelled DHBV DNA migrated as expected for linear double-stranded DNA 3.1 kilobase (kb) in length. Virus particles with characteristic DHBV morphology were observed in DHBV DNA-positive serum on electron microscopy. No overt morbidity has been noted in naturally infected ducks, but moderately severe hepatitis was found in 3/40 ducks examined histologically. These 3 ducks had DHBV DNA in serum and liver tissue. Mild hepatitis was observed in 27 ducks, but, in these, there was no correlation between the hepatitis and the presence of DHBV in serum or in liver tissue. This is the first report of DHBV in Australia. An animal model may now be established to study aspects of Hepadna virus infection which are pertinent to Hepatitis B virus (HBV) disease in man.
TL;DR: It is concluded that a single KUN genetic type has existed in enzootic and epizootic areas of virus activity over an extended time span.
Abstract: The genotypic relatedness of 15 Kunjin (KUN) virus isolates from widely separated geographic regions in Australia was examined at the molecular level HaeIII and TaqI restriction digest profiles of cDNA transcribed from virion RNA revealed a close genetic similarity between all isolates We estimate that the nucleotide sequence divergence between any pair of KUN isolates is probably less than 1% We conclude that a single KUN genetic type has existed in enzootic and epizootic areas of virus activity over an extended time span The epidemiological implications of these results are discussed
TL;DR: The omental pouch, gall bladder fossa and renal subcapsular space showed optimal implantation, preservation and vascularisation of graft tissue and represents a potentially suitable site for pancreatic islet tissue transplantation studies in the pig.
Abstract: Thyroid and thymus tissue autografts were used to examine the suitability of different transplant sites in the pig for endocrine tissue transplantation. The omental pouch, gall bladder fossa and renal subcapsular space showed optimal implantation, preservation and vascularisation of graft tissue. Marked dissemination of graft tissue was observed at intramuscular sites and graft viability at subcutaneous sites in the ear was poor. The omental pouch represents a potentially suitable site for pancreatic islet tissue transplantation studies in the pig.
TL;DR: The involvement of lipoxygenase in the production of hydroxyl radical was demonstrated by the trapping of the radical with DMPO in a reaction mixture of soybean lipoxyGENase and arachidonic acid (AA).
Abstract: Human neutrophils incubated with sodium arachidonate generated hydroxyl radicals. The radical formed an adduct with the spin trap 5', 5-dimethyl-l-pyrroline-N-oxide (DMPO) and was subsequently detected by electron spin resonance (ESR) spectroscopy. The ESR signal was inhibited by mannitol and superoxide dismutase but not by catalase. Removal of glucose from the reaction mixture or the presence of glucose metabolic inhibitors including 2-deoxy-D-glucose and 3-O-methyl-D-glucose did not affect the production of hydroxyl radical by the neutrophils. The ESR signal was, however, inhibited by the lipoxygenase inhibitors nordihydroguaiaretic acid and N-ethylmaleimide. The involvement of lipoxygenase in the production of hydroxyl radical was demonstrated by the trapping of the radical with DMPO in a reaction mixture of soybean lipoxygenase and arachidonic acid (AA). These findings support our previous postulation that the metabolism of AA via the lipoxygenase pathway is a source of hydroxyl radical in stimulated neutrophils.
TL;DR: A pattern of seasonal activity in the Murray Valley that is relevant to arbovirus epidemiology and to vector control is confirmed.
Abstract: Abundance of Culex annulirostris in a state forest near Echuca, northern Victoria, was sampled with a dry ice-baited EVS trap from 1979 to 1985, generally on a fortnightly basis. The species regularly became active from October, the population reached peak abundance in mid summer and then declined to become undetectable from late May. Abundance varied between years, related to availability of larval habitats. The results confirm a pattern of seasonal activity in the Murray Valley that is relevant to arbovirus epidemiology and to vector control.
TL;DR: A new medium, nutrient tween 80 broth (NTB) was utilised to achieve improved cultivation of Corynebacterium pseudotuberculosis and Immunity was expressed by a failure of organisms to localise at secondary sites although infection of primary sites in skin or peritoneal cavity occurred, apparently at a reduced level.
Abstract: ASPECTS OF PATHOGENESIS IN A MOUSE MODEL OF INFECTION BY CORYNEBACTERIUM PSEUDOTUBERCULOSIS
TL;DR: Pregnant mice infected on gestation day (GD) 6 with Plasmodium berghei showed a more rapid rate of increase in parasitaemia than mice infected later in pregnancy or non-pregnant controls, and compromised foetal development was likely to be the result of maternal anaemia, hyperplasia of placental trophoblast and plugging of placential sinusoids with parasitized red cells.
Abstract: Pregnant mice infected on gestation day (GD) 6 with Plasmodium berghei showed a more rapid rate of increase in parasitaemia than mice infected later in pregnancy or non-pregnant controls. All mice infected on GD 6 were dead by the 7th post-infection day. Pregnant mice infected on GD 13, in contrast, had similar rates of parasitaemia and mortality as non-pregnant controls and 50% delivered normally, the foetuses were absorbed in 20% and 30% died before parturition. The pups born to mice infected on GD 13 were smaller. This compromised foetal development was likely to be the result of maternal anaemia, hyperplasia of placental trophoblast and plugging of placental sinusoids with parasitized red cells.
TL;DR: The efficiency of a graft draining into the portal circulation is greater than an equivalent sized graft draining systemically when a maximal challenge is applied.
Abstract: A COMPARISON OF PORTAL VERSUS SYSTEMIC VENOUS DRAINAGE IN MURINE FOETAL PANCREATIC ISLET TRANSPLANTATION
TL;DR: The predominance of primary group 1 among strains of Aeromonas spp.
Abstract: The study included 138 A. sobria and 182 A. hydrophila isolated in Perth from samples of diarrhoeal or non-diarrhoeal faeces or from domestic water. Strains were grouped in relation to agglutination of human, horse, rat and guinea pig erythrocytes and the effect of sugars on haemagglutination. Agglutination of red cells of all four species (primary group 1) was most commonly associated with A. sobria, particularly those strains isolated from faeces of patients with diarrhoea. Most A. hydrophila associated with diarrhoea also belonged to group 1 but A. hydrophila from non-diarrhoeal stools or from water most commonly agglutinated human and guinea pig cells but not horse erythrocytes (primary groups 2 and 3). Fucose-resistant haemagglutination (FRHA) of strains in primary group 1 occurred with about 68% of the strains of A. sobria associated with diarrhoea. Mannose-resistant haemagglutination (MRHA) was limited to 29% of strains of A. sobria associated with diarrhoea. The predominance of primary group 1 among strains of Aeromonas spp. associated with diarrhoea and the proportion of these strains showing FRHA suggest that haemagglutination of cells from human, horse, rat and guinea pig, particularly if fucose-resistant, should be considered in a search for characteristics, which possibly contribute to virulence of Aeromonas spp.
TL;DR: The radio inhibitor binding assay for human serum ACE is a simple, sensitive and specific assay which utilizes novel assay methodology and correlated closely with the methods for ACE estimation.
Abstract: ANGIOTENSIN-CONVERTING ENZYME (ACE) MEASUREMENT IN HUMAN SERUM USING RADIOINHIBITOR LIGAND BINDING
TL;DR: Serum aspartate amino transferase values, serum, heart and aortic lipids, serum protein-bound hexose and sialic acid and glycosaminoglycans in the heart were lower in the carnitine-treated rats, while necrosis in the untreated controls was very little.
Abstract: The effect of administration of carnitine on the severity of myocardial infarction in rats induced by isoproterenol was studied by following histopathological and biochemical parameters. Carnitine afforded partial protection against myocardial infarction. Serum aspartate amino transferase (GOT) and creative phospho kinase (CPK) values, serum, heart and aortic lipids, serum protein-bound hexose and sialic acid and glycosaminoglycans in the heart were lower in the carnitine-treated rats. Histopathological examination showed very little necrosis in the carnitine-treated rats when compared to the extensive necrosis in the untreated controls.
TL;DR: The data suggest that there is no difference between the number of mast cells in normal and asthmatic lung, however, in pulmonary mast cells from asthitic lung, degranulation is more common than in normal lung.
Abstract: Specimens of normal and asthmatic lungs were studied at the electron microscopic level and the frequency and ultrastructural features of mast cells and their granules within the alveolar wall were assessed with morphometric techniques. The numerical density of mast cells per square millimetre of alveolar wall was 299 (SD = 258) in normal and 366 (SD = 260) in asthmatic lung. The mean area of the mast cell nucleated profile was 25.7 microns2 (SD = 6.3) in normal lung and 29.8 (SD = 6.2) in asthmatic. The average number of secretory granules per single mast cell nucleated profile was 55 (SD = 13) in normal lung and 60 (SD = 12) in asthmatic lung. The diameter of the individual secretory granule was 338.9 nm (SD = 42.6) in normal and 345.6 (SD = 47.7) in asthmatic lung. The volume density of secretory granules in normal and asthmatic lung was 6.31 microns3 and 5.81 microns3, respectively. The mean diameter of the individual subunit ('scroll') inside the secretory granule was 88.8 nm for both normal and asthmatic lung. In normal lung 64.2% of granules were of 'scroll' and 'combined' type, and 35.8% of granules were 'particulate' or 'empty'. In specimens from asthmatic patients 40.3% of granules had 'scroll' or 'combined' structures and 59.7% were 'particulate' or 'empty'. Our data suggest that there is no difference between the number of mast cells in normal and asthmatic lung. However, in pulmonary mast cells from asthmatic lung, degranulation is more common than in normal lung.
TL;DR: The functional characteristics of peritoneal cells acquired in response to infection with Nematospiroides dubius were studied to identify changes which could be associated with the high level, long-term survival of this parasite or explain its transient immunosuppressive properties.
Abstract: The functional characteristics of peritoneal cells (PC's) acquired in response to infection with Nematospiroides dubius were studied to identify changes which could be associated with the high level, long-term survival of this parasite or explain its transient immunosuppressive properties. The number of cells in the peritoneal cavity increased steadily during the infection, and the population displayed a transient hyperresponsiveness to inflammatory stimulation. N. dubius did not affect the ability of antigen-pulsed PC's to induce humoral responses or delayed-type hypersensitivity (DTH) in primed recipients, but lymphoproliferative responses induced in vitro were depressed by PC's from infected donors. In addition, unpulsed PC's from N. dubius-infected mice depressed proliferative responses to parasite antigens by autologous mesenteric lymph node cells. These effects are attributable to increased lymphocytostatic activity in the PC's, which peaked one week after infection and correlated with the expansion of a population of large plastic-adherent vacuolated cells with elevated acid phosphatase activity (activated macrophages). Comparable inhibitory cells did not develop in the same period of time during a short-lived infection with Nippostrongylus brasiliensis.
TL;DR: It is found that rapidly adapting receptor activity (and any unmyelinated fibre activity provoked by rapid inflation or deflation of the lungs) never directly shortened inspiration, and a mechanism whereby rapidly adapting receptors may indirectly affect duration of inspiration is proposed.
Abstract: We analysed the breathing pattern of anaesthetised rabbits during unloaded breathing when breathing was accelerated by inspired CO2 and when they breathed against positive or negative pressures before and during block of pulmonary stretch receptors by SO2, and after bilateral vagotomy. Before block moderate steps of inflation or deflation (0.5 kPa) produced relatively larger changes in duration of expiration than in duration of inspiration, indicating the relative sensitivities of the two phases. With stretch receptors, blocked inflation or deflation shortened expiration, demonstrating the influence of rapidly adapting receptors on that phase of breathing. If pulmonary stretch receptors were the major determinants of the duration of inspiration, we would have expected inspiratory duration in the stretch receptor blocked and vagotomised states to be almost identical. They were not, inspiratory duration being less in the blocked than in the vagotomised state. Possibly vagal afferent activity other than that of stretch receptors shortens inspiratory duration. However, we have found that rapidly adapting receptor activity (and any unmyelinated fibre activity provoked by rapid inflation or deflation of the lungs) never directly shortened inspiration. We therefore propose a mechanism whereby rapidly adapting receptors may indirectly affect duration of inspiration.
TL;DR: It is deduced that the catabolism of PGs and the extent of collagen cross-linking in EGPC of TTM-treated animals may be reduced relative to age-matched control tissues.
Abstract: As part of a project to study the effect of copper deficiency (CD) on bone development in young dogs, the composition and metabolism of proteoglycans (PGs) and extractability of collagens in the epiphyseal growth plate cartilage (EGPC) and articular cartilages (AC) were investigated. Copper deficiency was induced by feeding ammonium tetrathiomolybdate (TTM) a copper antagonist. The collagen of cartilages from TTM-treated animals was significantly more soluble in 0.5 saline than control tissues. While no distinction between TTM-treated and control cartilages was evident in terms of PG content or extractability under associative (0.5 M-GuHCl) or dissociative (4.0 M-GuHCl) conditions, the sedimentation behaviour of the PG aggregates following CsCl density gradient ultracentrifugation suggested less polydispersity of PGs in preparations from the TTM-treated animals. Moreover, analysis of the PG monomers from EGPC of TTM animals showed galactosamine/glucosamine ratios higher than control preparations, suggesting a reduced keratan sulphate content in these preparations. Organ culture of EGPC showed a significant reduction in the incorporation of 35S into PGs and of 3H-thymidine into DNA in the tissues of TTM-treated animals relative to controls. From these findings we deduce that the catabolism of PGs and the extent of collagen cross-linking in EGPC of TTM-treated animals may be reduced relative to age-matched control tissues.
TL;DR: A high level of resistance was recorded in mice exposed once or repeatedly to cercariae of Schistosoma mansoni and worm burdens determined, in keeping with reports of S. japonicum infection in these mice.
Abstract: Mice of the strain 129/J bred at this Institute (WEHI 129/J) were exposed once or repeatedly to cercariae of Schistosoma mansoni and worm burdens determined. In keeping with reports of S. japonicum infection in these mice, a high level of resistance was recorded. Radio-labelled extracted antigens of S. mansoni adult worms were reacted with sera from exposed 129/J mice and infected BALB/c mice. Immunoprecipitated antigens preferentially recognized by antibodies in 129/J mice include proteins of Mr 99,000 and 21,000. Whether responses to these antigens are a cause or a consequence of resistance remains to be established.
TL;DR: Peritoneal cells from mice infected with Plasmodium vinckei vinc kei generate about four times more prostaglandin F and 6-keto prostaglandsin F1 alpha than do peritonealcells from normal mice, providing additional evidence that macrophage activation occurs in malaria.
Abstract: INCREASED PRODUCTION OF ARACHIDONATE METABOLITES BY PERITONEAL CELLS OF MICE INFECTED WITH PLASMODIUM VINCKEI VINCKEI
TL;DR: Unlabelled CPZ or TU was not selectively toxic to melanoma cells and methylation-sensitive tumour cells (Mer-phenotype) were highly resistant to TU, thus providing a new experimental tool for understanding the genesis of this phenotype in vivo.
Abstract: The uptake (total radioactivity in intact cells) and incorporation (radioactivity bound to acid-precipitable material) of 14C-chlorpromazine (CPZ) and 14C-thiouracil (TU) were studied using a library of 3 human fibroblast strains and 13 tumour cell lines. In contrast to previous studies using rodent melanomas in vivo, the melanoma lines, including lines with high tyrosinase and melanin contents, did not take up more CPZ and TU than non-melanoma cells (fibroblasts, HeLa cells). Incorporation of CPZ was also broadly similar in all cell types studied. TU was selectively incorporated into the melanoma line having a high tyrosinase and melanin content but not into lines with high tyrosinase activity and low melanin content. While supporting the possibility of selective therapy for heavily-pigmented melanomas using labelled TU derivatives, these results suggest that the action of potentially melanoma-affined compounds should be further evaluated in human cells. Unlabelled CPZ or TU was not selectively toxic to melanoma cells. Unexpectedly, methylation-sensitive tumour cells (Mer-phenotype) were highly resistant to TU, thus providing a new experimental tool for understanding the genesis of this phenotype in vivo.
TL;DR: The alpha-globin gene deletion was detected in Aboriginal DNA samples collected from Kalumburu in the Kimberley region of Western Australia and was found also in one sample from Mowanjum, near Derby in Western Australia, and in one from Mornington Island in the Gulf of Carpentaria as discussed by the authors.
Abstract: alpha- and beta-thalassaemias and other haemoglobinopathies have not so far been reported in Australian Aborigines. Using a DNA mapping technique, we tested groups of Aborigines for a deletion form of alpha-thalassaemia and found that there was a single alpha-globin gene deletion (-alpha/alpha alpha) in some populations. The alpha-globin gene deletion was detected in Aboriginal DNA samples collected from Kalumburu in the Kimberley region of Western Australia. It was found also in one sample from Mowanjum, near Derby in Western Australia, and in one from Mornington Island in the Gulf of Carpentaria. It was not observed in Aboriginal DNA samples from the central desert. Further analysis of the alpha-globin gene deletion revealed that it was of the 3.7 kilobase (Kb) (-alpha 3.7) type. However, the -alpha 3.7 deletion in the Aborigines is apparently different from that found in southern Papua New Guinea as it is linked to a different zeta-globin gene polymorphism. The presence of this silent alpha-thalassaemia in several populations of Aborigines may be explained in several ways. The most likely is through contact with Macassans or other voyagers from the Indonesian and Southeast Asian areas.
TL;DR: Reduced thecal blood flow is associated with advanced atresia of antral follicles and is in accordance with the findings of previous histological studies, which indicate that thecal ischaemia is a factor involved in the onset of atResia.
Abstract: The relative level of blood flow through thecal capillaries (RTF) in individual atretic and non-atretic follicles greater than 1 mm was measured in conscious ewes by injecting 15 micron radioactive microspheres into the aorta near the origin of the ovarian artery, and determining the ratio of radioactivity per mg protein in theca of individual follicles to that in the non-luteal portion (stroma plus follicles less than 1 mm diameter) of the corresponding ovary. In follicles greater than 1 mm diameter, RTF in those showing advanced stages of atresia (stages IV and V) was significantly less than that in non-atretic (stage I) follicles. RTF values in non-atretic (stage I), early atretic (stage II) and moderately atretic (stage III) follicles did not differ significantly. There was no effect of follicular diameter (P greater than 0.05) on the relative level of blood flow within individual thecae or of atresia on thecal protein content. These data indicate that reduced thecal blood flow is associated with advanced atresia of antral follicles and are in accordance with the findings of previous histological studies. Whether thecal ischaemia is a factor involved in the onset of atresia, or occurs as a consequence of the degenerative process, remains uncertain.