Enhanced MHC I antigen expression on tumour target cells is inversely correlated to lysis by allogenic but not by xenogenic NK cells

Relationship between the levels of MHC class 1 antigen expressed on tumour cells and their susceptibility to allogenic and xenogenic NK cells was investigated. Mouse and human natural killer-resistance inducing factor (NK-RIF) preparations were used for augmenting/inducing MHC 1 antigen expression on murine YAC and human K562 tumour cells, respectively YAC cells with augmented MHC I antigen expression became relatively resistant to lysis by murine NK cells but not to rat NK cells. Similarly, induction of MHC I antigens on K562 cells reduced their susceptibility to human NK cells but not to monkey NK cells. These results indicate that the inverse correlation of MHC I antigen expression and NK susceptibility does not hold true for xenogenic pairs of NK effector and target cells

Partial purification and characterization of a novel human factor that augments the expression of class I MHC antigens on tumour cells

A cytokine which augments the expression of major histocompatibility complex (MHC) I antigens on K562 and gastric carcinoma tumour (HR) cells, has been isolated from the culture supernatant of Concanavalin-A (Con-A) activated human peripheral blood mononuclear cells. The factor, termed MHC augmenting factor (MHC- AF) has been partially purified by Sephadex G- 100 column chromatography, preparative isoelectric focusing and HPLC with ion- exchange as well as sizing columns. MHC-AF activity is associated with a 35 kDa molecule which has pI of 6.0. Interferon (IFN)-α, β, tumour necrosis factor (TNF), Interleukin (IL)-2, IL-4, IL-5 and IL-7 had no significant effect in MHC- AF bioassay, but IFN-γ had significant MHC-AF activity. Antibodies to IFN-α , IFN-β and TNF-α did not block the activity of MHC-AF, but anti-IFN-y antibodies could partially neutralize the activity. However, unlike IFN-γ , MHC-AF activity was resistant to pH 2.0 treatment. Purified MHC-AF preparations did not have any activity in WISH cell/encephalo myocarditis virus (EMC) IFN bioassays. In addition, anti-IFN-y affinity column did not retain MHC-AF activity. These results indicate that a MHC-AF distinct from IFN-γ, is produced by activated human mononuclear cells

The glass transition and crystallization kinetic studies on BaNaB9O15 glasses

Transparent glasses of BaNaB9O15 (BNBO) were fabricated via the conventional melt-quenching technique. The amorphous and the glassy nature of the as-quenched samples were respectively, confirmed by X-ray powder diffraction (XRD) and differential scanning calorimetry (DSC). The glass transition and crystallization parameters were evaluated under non-isothermal conditions using DSC. The correlation between the heating rate dependent glass transition and the crystallization temperatures was discussed and deduced the Kauzmann temperature for BNBO glass-plates and powdered samples. The values of the Kauzmann temperature for the plates and powdered samples were 776 K and 768 K, respectively. Approximation-free method was used to evaluate the crystallization kinetic parameters for the BNBO glass samples. The effect of the sample thickness on the crystallization kinetics of BNBO glasses was also investigated.Comment: 23 pages, 12 figure

Integrated Disease Management of Root Rot Disease of Cowpea ( \u3cem\u3e Vigna unguiculata \u3c/em\u3e (L) Walp.)

Cowpea (Vigna unguiculata (L) Walp.) is a warm season annual leguminous fodder crop. It is rich in protein and forms an excellent mixture with maize, sorghum, pearl millet and teosinte for increasing the milk production. The productivity of green fodder cowpea is approximately 25-45 t/ha in India. Pests and diseases hampers crop establishment, impair forage quality and reduces green fodder and seed yield. Besides causing direct yield losses they also suppress nodulation and consequently negating the maximum nitrogen fixation. The losses in green fodder and seed yields were estimated to be about 28.8 and 39.7 per cent, respectively (Ram and Gupta, 1988). Sometimes the pests and diseases are responsible for crop failure. Control of plant diseases is essential for providing an adequate and quality supply of fodder. Attempts were made to prevent fodder crops from diseases even then, losses are occurring. Reducing such losses has long been a high priority objective for forage production. In order to develop an integrated disease management approach, it is essential to appraise the newer molecules of fungicides against causal organism along with bio-control agents for its efficacy. Therefore, a study was conducted to evaluate the fungicides and bioagents against cowpea root rot pathogen (Rhizoctonia solani)

Can a speed breeding approach accelerate genetic gain in pigeonpea?

Pure line breeding is a resource-intensive activity that takes 10 years or more to develop a new cultivar. In some crops, conducting off-season nurseries has significantly reduced the length of the breeding cycle. This approach could not be exploited in pigeonpea [Cajanus cajan (L.) Millsp.], because traditionally it has been a photoperiod-sensitive crop that requires long periods of darkness to induce flowering. However, the recent success of breeding early maturing photoperiod-insensitive genotypes has opened up the possibility of adopting ‘speed breeding’ techniques to enable rapid generation turnover. This paper outlines a speed breeding approach that integrates the use of immature seed germination for rapid generation advancement and a "single pod descent" method of breeding. To accelerate line development, while conserving genetic variability, the approach permits four generations per year and can fast-track field evaluation of resulting homozygous lines. Therefore, the breeding strategy conserves resources and has potential to deliver new early maturing cultivars within a substantially reduced timeframe of 4–5 years

OM-VPE grown materials for high efficiency solar cells

Organometallic sources are available for all the III-V elements and a variety of dopants; thus it is possible to use the technique to grow a wide variety of semiconductor compounds. AlGaAsSb and AlGaInAs alloys for multijunction monolithic solar cells were grown by OM-VPE. While the effort concentrated on terrestrial applications, the success of OM-VPE grown GaAs/AlGaAs concentrator solar cells (23% at 400 suns) demonstrates that OM-VPE is suitable for growing high efficiency solar cells in large quantities for space applications. In addition, OM-VPE offers the potential for substantial cost reduction of photovoltaic devices with scale up and automation and due to high process yield from reproducible, uniform epitaxial growths with excellent surface morphology

Arresting Soil Erosion in Hilly Terrains with Pigeonpea - The Chinese Experience

Conservation of the nutrient-rich top soil is extremely important for sustaining agricultural productivity. It is now becoming a serious crop production constraint, particularly in the slopping hilly terrains. The ecology of such areas is rapidly deteriorating and their recovery seems extremely difficult. In southern China, where soil erosion is a serious issue, various plant species were unsuccessfully tried in the past to arrest the soil erosion. The Chinese scientists, in collaboration with ICRISAT, used late maturing pigeonpea cultivars to protect the fragile lands in Guangxi and Yunnan provinces. The planted area under pigeonpea in this system rapidly increased to 700 ha by 2001. This paper summarizes the methodologies used in soil conservation practices involving pigeonpea

Theoretical Study on Coexistence of Ferromagnetism and Superconductivity

On the basis of a two-dimensional t-t' Hubbard model in ferromagnetic and paramagnetic states, the triplet superconducting mechanism is investigated by the third-order perturbation theory with respect to the on-site Coulomb interaction U. In general, the superconducting state is more stable in the paramagnetic state than in the ferromagnetic state. As a special case, the dominant ferromagnetic superconductivity is obtained by the electron-electron correlation between the electronlike majority and holelike minority bands. Furthermore, it is pointed out that in some cases the two bands play an essential role for the coexistence of superconductivity and ferromagnetism.Comment: 5 pages, 10 figure