Identification of Cytolytic CD161?CD56+ Regulatory CD8 T Cells in Human Peripheral Blood

We previously developed methods for establishing CD8 regulatory T cell (Treg) clones from normal human peripheral blood and demonstrated that these clones were capable of killing T cell receptor (TCR)-activated autologous CD4 T cells. Based on phenotypic and functional characterization of the CD8 Treg clones, we have identified a corresponding population of endogenous CD8 Treg in normal human peripheral blood. These cells appear morphologically as large lymphocytes with abundant cytoplasm and have the following unique phenotype: CD3⁺CD8⁺CD161⁻CD56⁺. The majority of CD8 Treg express CD45RA and CD62L with low or negative expression of CD45RO, CD25, CD27, CD28 and CCR7. The expression of CD94 and NKG2a on CD8 Treg was elevated compared to conventional CD8 T cells. Following in vitro activation, this T cell subset is capable of killing TCR-activated CD4 T cells. These studies identify an endogenous CD8 Treg population in humans and it will now be possible to characterize these cells in a variety of clinical conditions.     

Demonstration and characterization of 1,25-dihydroxyvitamin D3 receptors in human mononuclear blood cells

Circulating human mononuclear blood cells were studied for the presence of specific 1,25-dihydroxyvitamin D3 (calcitriol) binding macromolecules. Cells were isolated by density gradient centrifugation and characterized by surface markers. Specific reversible high affinity binding by a 3.5 S macromolecule was demonstrated in malignant B-cells and circulating monocytes. In monocytes specific calcitriol binding was found both in the presence and absence of vitamin D3 to saturate the vitamin D3 binding serum protein. No specific calcitriol binding was found in resting B or T lymphocytes. The data suggest a role of calcitriol in the control of mononuclear blood cell proliferation/differentiation.     

Nutrient transport between ryegrass plants differeing in nutrient status

Summary It is known that nitrogen and phosphorus can be transferred from one living plant to another, but it is not known whether the amounts transferred are large enough to influence the growth of the species in the field. Two Lolium perenne plants were grown per pot of unfertilized soil. During 25 weeks one plant (the donor) in each pot was fed nutrients through leaves; donors in control pots received only water. The receiver plants which shared a pot with the nutrient-fed donors increased significantly, compared with the controls, in leaf number and concentration of phosphorus, though not in concentration of nitrogen, potassium, calcium or magnesium. The rate of phosphorus transfer agreed well with previous results using ³²P. The results are compared with rates of phosphorus uptake in the field. It is concluded that nutrient transfer could have an influence on the balance between coexisting species in the field, but probably the influence will be small.     

The use of zootherapeutics in folk veterinary medicine in the district of Cubati, Paraíba State, Brazil

Background

Viewed through the micro focus of an interpretive lens, medical anthropology remains mystified because interpretivist explanations seriously downplay the given context in which individual health seeking-behaviours occur. This paper draws upon both the interpretivist and political economy perspectives to reflect on the ethno medical practices within the Korean-Australian community in Sydney.

Methods

We draw on research data collected between 1995 and 1997 for an earlier study of the use of biomedical and traditional medicine by Korean-Australians in Sydney. A total of 120 interviews were conducted with a range of participants, including biomedical doctors, traditional health professionals, Korean community leaders and Korean migrants representing a range of socio-economic backgrounds and migration patterns.

Results and Discussion

First, the paper highlights the extent to which the social location of migrants in a host society alters or restructures their initial cultural practices they bring with them. Second, taking hanbang medicine in the Korean-Australian community as an illustrative case, the paper explores the transformation of the dominant biomedicine in Australia as a result of the influx of ethnomedicine in the era of global capitalism and global movement.

Conclusion

In seeking to explain the popularity and supply of alternative health care, it is important to go beyond the culture of each kind of health care itself and to take into consideration the changes occurring at societal, national and global levels as well as consequential individual response to the changes. New social conditions influence the choice of health care methods, including herbal/alternative medicine, health foods and what are often called New Age therapies.     

Changes in temperature tolerance ofBalanus balanoides during its life-cycle

Summary 1. The barnacleBalanus balanoides exhibits little seasonal variation in upper lethal temperatures in North Wales.2. There are marked seasonal changes in resistance to sub-zero temperatures, the lower lethal varying from –6.0° C in June to –17.6° C in January.3. Exceptional tolerance to cold is acquired between December and January and is lost between February and April. Although these dates coincide with oviposition and naupliar liberation respectively, it was found that cold tolerance did not necessarily depend upon, or accompany, the normal breeding cycle.4. Cold tolerance was not acquired by animals kept cold in the laboratory during winter, nor was it lost in animals kept in the laboratory during spring. There was no evidence that changes in nutrition or in the light régime led to loss of cold tolerance.5. The cyprids were considerably less resistant to both high and low temperatures than the overwintering adults and the late-stage embryos. There was a marked increase in resistance at metamorphosis.6. The appearance of cold tolerance in the adult coincides with a period of physiological hibernation, involving loss of certain tissues, diminished feeding activity, respiration and biosynthesis. The metabolic inactivity of the animal may be a factor promoting the greatly increased tolerance to cold that we have observed, while the composition of the body fluids may also be modified during the winter in such a way as to protect the tissues.

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Veränderungen der Temperaturtoleranz vonBalanus balanoides während seines Lebenszyklus

Kurzfassung In Nordwales weisen die oberen Letaltemperaturen des CirripediersB. balanoides nur geringe jahreszeitliche Variationen auf. Jedoch treten je nach der Jahreszeit merkbare Resistenzveränderungen bei Temperaturen unter Null auf, wobei die untere Letaltemperatur von –6,0° C im Juni bis zu –17,6° C im Januar schwankt. Eine außergewöhnlich starke Kältetoleranz wird in der Zeit von Dezember und Januar erworben und zwischen Februar und April wieder verloren. Obwohl diese Zeitspanne mit der Oviposition beziehungsweise dem Schlüpfen der Nauplien zusammenfallen, konnte festgestellt werden, daß die Kältetoleranz nicht notwendigerweise vom Brutzyklus abhing oder diesen begleitete. Unter Laboratoriumsbedingungen wurde von kalt gehaltenen Tieren eine Kälteresistenz nicht erworben, auch ging diese bei Tieren, die während des Frühlings im Labor verblieben, nicht verloren. Es ließ sich nicht beweisen, daß Veränderungen in der Ernährung oder Änderungen in der Tageslänge zu einem Verlust der Kälteresistenz führen. Die Cypriden waren wesentlich weniger widerstandsfähig, sowohl gegenüber hohen wie niedrigen Temperaturen, als überwinternde Adulte und die ältesten Embryostadien. Während der Metamorphose zeigte sich eine merkliche Erhöhung der Temperaturresistenz. Das Auftreten der Kälteresistenz beim Adultus fiel mit einer Periode physiologischen Winterschlafs zusammen, wobei gewisse Gewebe reduziert wurden und Nahrungsaufnahme, Atmung und biosynthetische Aktivität nachließen. Dieser stoffwechselphysiologische Aktivitätsrückgang könnte ein Faktor sein, der die beobachtete erhöhte Kältetoleranz fördert. Außerdem wird möglicherweise auch die Zusammensetzung der Körperflüssigkeiten während des Winters so verändert, daß die Gewebe geschützt werden.

     

Hybridisation between South polar skua (Catharacta maccormicki) and Brown skua (C. antarctica lonnbergi) in the Antarctic Peninsula region

Hybridisation between South polar skua (C. maccormicki) and Brown skua (C. antarctica lonnbergi) in the area of the Antarctic Peninsula is known at least since the beginning of the last century but no survey has been done so far. This paper reviews information on the species composition of skua colonies of more than 10 pairs in the Antarctic Peninsula region, and the incidence of mixed pairs. Morphometrics, population size and breeding success were examined in detail at King George Island. The northward distribution of South polar skuas extended to King George Island (62°11′ S 59°00′ W), with a small outlying population on Signy Island (60°45′ S 45°36′ W), whereas Brown skuas did not breed further south than Anvers Island archipelago (64°46′ S 64°03′ W). The proportion of mixed pairs was highest at the northern end of the ∼500-km-wide hybrid zone. Body size distribution of sympatric skuas from King George Island is clearly bimodal but overlaps considerably and hybrids cannot be identified. Skua population sizes at Potter Peninsula/King George Island remained stable between 1994 and 2004. Numbers of mixed breeding pairs fluctuated more strongly than those of pure species pairs. Breeding success of Brown skuas varied the least.     

Survival of <Emphasis Type="Italic">Campylobacter jejuni</Emphasis> Strains from Different Origins Under Oxidative Stress Conditions: Effect of Temperature

Campylobacter jejuni is a microaerophilic pathogen but is able to survive oxidative stress conditions during its transmission to the human host. Strains of different origins (reference, poultry, or human clinical) were tested for survival under oxidative stress conditions. C. jejuni strains were grown in Mueller Hinton broth to obtain late exponential–phase cultures. Then they were exposed to 2 different stresses: (1) cultures were either plated on Columbia agar plates and exposed to atmospheric oxygen or (2) paraquat (a chemical oxidizing agent) was added to liquid cultures to reach a 500-μM concentration. Both of these experimental conditions were realized at 3 different temperatures: 4°C, 25°C, and 42°C. Results obtained with paraquat and atmospheric oxygen were similar. Surprisingly, C. jejuni was found to be very sensitive to oxidative stress at 42°C, which is its optimal growth temperature, whereas it was more resistant at 4°C. A strain effect was observed, but no relationship was found between the origin of the strains and level of resistance. High temperature (42°C) combined with oxidative stress allowed a rapid decrease in the C. jejuni population, whereas low temperature considerably decreased the effect of oxidative stress.     

The Bradyrhizobium japonicum cycM gene encodes a membrane-anchored homolog of mitochondrial cytochrome c.

Mitochondrial cytochrome c is a water-soluble protein in the intermembrane space which catalyzes electron transfer from the cytochrome bc1 complex to the terminal oxidase cytochrome aa3. In Bradyrhizobium japonicum, a gene (cycM) which apparently encodes a membrane-anchored homolog of mitochondrial cytochrome c was discovered. The apoprotein deduced from the nucleotide sequence of the cycM gene consists of 184 amino acids with a calculated Mr of 19,098 and an isoelectric point of 8.35. At the N-terminal end (positions 9 to 31), there was a strongly hydrophobic domain which, by forming a transmembrane helix, could serve first as a transport signal and then as a membrane anchor. The rest of the protein was hydrophilic and, starting at position 72, shared about 50% sequence identity with mitochondrial cytochrome c. The heme-binding-site motif Cys-Gly-Ala-Cys-His was located at positions 84 to 88. A B. japonicum cycM insertion mutant (COX122) exhibited an oxidase-negative phenotype and apparently lacked cytochrome aa3 in addition to the CycM protein. The wild-type phenotype with respect to all characteristics tested was restored by providing the cycM gene in trans. The data supported the conclusion that the assembly of cytochrome aa3 depended on the prior incorporation of the CycM protein in the cytoplasmic membrane.     

Influence of aflatoxin B1 on seed germination, seedling growth, chlorophyll and carotenoid contents of mustard (brassica juncea L. var. pusa bold) seeds

Five different concentrations (100, 250, 500, 1000 and 2000 μg/L of aflatoxin B₁ were found to be inhibitory to seed germination and seedling growth (root and shoot lengths) of mustard seeds (variety Pusa bold). These also lowered the levels of chlorophyll and carotenoids in the emerging leaves during seedling growth. The inhibitory effect was correlated with the concentration of applied toxin.     

17beta-estradiol effect on the extracellular concentration of amino acids in the glutamate excitotoxicity model in the rat

Estrogen has demonstrated a neuroprotective role in a rat model of glutamate excitotoxicity and other neurodegenerative disorders. We studied the effect of 17-estradiol on glutamate-induced increases in amino acids levels (aspartate, histidine, taurine and GABA) in the rat cortex. Local perfusion of glutamate produced a transient increase of aspartate, histidine, taurine and GABA in the extracellular fluid. Pretreatment with 17-estradiol significantly reduced the increases of taurine and moderately attenuated that of histidine, whereas aspartate and GABA releases were not modified. The effect of 17-estradiol on histidine release was reversed by the antiestrogen tamoxifen, suggesting a receptor-dependent mechanism. Good correlations between the volumes of the glutamate-induced lesions and the extracellular concentrations of taurine and aspartate were observed. These findings suggest that the attenuation of the glutamate-induced release of taurine by 17-estradiol may participate in the neuroprotective effects of 17-estradiol and that increased levels of aspartate and taurine are markers for the severity of the glutamate-induced cortical lesions.