Immune response to ferredoxin; nonresponder status is not due to suppression

Ferredoxin (Fd), a small protein from Clostridium pasteurianum, has been selected for immunologic studies because of its limited number (two) of antigenic determinants. Functionally (as determined by antibody binding), monodeterminant fragments of Fd can be generated enzymatically, leaving molecules only a few amino acids smaller than the native protein, with unaltered solid phase binding properties. These fragments were used to assess the immune response to each of the two determinants. Clear differences in immunologic properties can be assigned to sequences within Fd: the amino terminal tripeptide is responsible for inducing a proliferative response and limited antibody production, whereas the carboxy terminal dipeptide accounts for most of the antibody activity, yet little, if any, T-proliferative activity. Studies with the enzyme-generated fragments of Fd have unmasked a sequence proximal to the amino terminal that represents a second determinant for T cell proliferation but does not have any demonstrable antibody-inducing activity. This third determinant is shown to induce responsiveness to Fd in nonresponder animals after the removal of the amino terminal tripeptide. The results indicate that nonresponsiveness to this molecule in H-2d mice is not a direct effect of suppression.     

Genes,dreams, and cancer.

There have been tremendous advances in our understanding of cancer from the application of molecular biology over the past decade. The disease is caused by a series of defects in the genes that accelerate growth--oncogenes--and those that slow down cellular turnover--tumour suppressor genes. The proteins they encode provide a promising hunting ground in which to design and test new anticancer drugs. Several treatment strategies are now under clinical trial entailing direct gene transfer. These include the use of gene marking to detect minimal residual disease, the production of novel cancer vaccines by the insertion of genes which uncloak cancer cells so making them visible to the host''s immune system, the isolation and coupling of cancer specific molecular switches upstream of drug activating genes, and the correction of aberrant oncogenes or tumour suppressor genes. The issues in these approaches are likely to have a profound impact on the management of cancer patients as we enter the next century.     

An extensive review on antifungal approaches in the treatment of mucormycosis

During the period of COVID-19, the occurrences of mucormycosis in immunocompromised patients have increased significantly. Mucormycosis (black fungus) is a rare and rapidly progressing fungal infection associated with high mortality and morbidity in India as well as globally. The causative agents for this infection are collectively called mucoromycetes which are the members of the order Mucorales. The diagnosis of the infection needs to be performed as soon as the occurrence of clinical symptoms which differs with types of Mucorales infection. Imaging techniques magnetic resonance imaging or computed tomography scan, culture testing, and microscopy are the approaches for the diagnosis. After the diagnosis of the infection is confirmed, rapid action is needed for the treatment in the form of antifungal therapy or surgery depending upon the severity of the infection. Delaying in treatment declines the chances of survival. In antifungal therapy, there are two approaches first-line therapy (monotherapy) and combination therapy. Amphotericin B ( 1 ) and isavuconazole ( 2 ) are the drugs of choice for first-line therapy in the treatment of mucormycosis. Salvage therapy with posaconazole ( 3 ) and deferasirox ( 4 ) is another approach for patients who are not responsible for any other therapy. Adjunctive therapy is also used in the treatment of mucormycosis along with first-line therapy, which involves hyperbaric oxygen and cytokine therapy. There are some drugs like VT-1161 ( 5 ) and APX001A ( 6 ), Colistin, SCH 42427, and PC1244 that are under clinical trials. Despite all these approaches, none can be 100% successful in giving results. Therefore, new medications with favorable or little side effects are required for the treatment of mucormycosis.     

Cytoplasmic streaming inParamecium

Summary Certain species ofParamecium demonstrate rotational cytoplasmic streaming, in which most cytoplasmic particles and organelles flow along permanent route, in a constant direction. By means of novel methods of immobilization, observation and recording, some dynamic properties of cytoplasmic streaming have been described. It was found that the velocity profiles of coaxial layers of cytoplasm have a (parabolic) paraboidal shape and the mean output of cytoplasm flow in different examined zones of streaming is constant. As the consequence of randomly distributed elementary propulsion units within the cytoplasm, particles, which serve as markers of movement, exhibit movements of a saltatory nature; this form of movement is seen inParamecium streaming only in cases of error due to polarization of the saltating particles. Interaction of actin filaments and myosin is likely to occur under specific conditions in microcompartments of cytoplasm where local solations are generated eventually leading to contractions which might propagate on gelated neighbouring areas. Places of elementary contractions are scattered. Therefore the motile effect appears as streaming. Rotational cytoplasmic streaming inParamecium may serve as a convenient model for the study of the dynamics and function of cytoplasmic motility.     

The estimation of velocity distribution profile of Paramecium cytoplasmic streaming.

Cytoplasmic streaming of Paramecium bursaria and Paramecium tetraurelia was investigated by cinematographic techniques. Analysis of the records reveals the paraboidal character of the velocity distribution profiles in all arbitrarily chosen zones along the whole route of moving cytoplasm in the cell. According to the date obtained from cytoplasmic streaming analysis and food vacuole path, the geometry of the "channel" was described in terms of ellipsoid axes. Total volume changes of cytoplasm flowing through a given cross section in a given time unit were computed and no significant differences were found. The participation of a pressure gradient in motive force generation in cytoplasmic streaming is discussed.     

Influence of different Sinorhizobium meliloti inocula on abundance of genes involved in nitrogen transformations in the rhizosphere of alfalfa (Medicago sativa L.)

Inoculation of leguminous seeds with selected rhizobial strains is practised in agriculture to ameliorate the plant yield by enhanced root nodulation and nitrogen uptake of the plant. However, effective symbiosis between legumes and rhizobia does not only depend on the capacity of nitrogen fixation but also on the entire nitrogen turnover in the rhizosphere. We investigated the influence of seed inoculation with two indigenous Sinorhizobium meliloti strains exhibiting different efficiency concerning plant growth promotion on nitrogen turnover processes in the rhizosphere during the growth of alfalfa. Quantification of six target genes (bacterial amoA, nirK, nirS, nosZ, nifH and archaeal amoA) within the nitrogen cycle was performed in rhizosphere samples before nodule formation, at bud development and at the late flowering stage. The results clearly demonstrated that effectiveness of rhizobial inocula is related to abundance of nifH genes in the late flowering phase of alfalfa. Moreover, other genes involved in nitrogen turnover had been affected by the inocula, e.g. higher numbers of amoA copies were observed during flowering when the more effective strain had been inoculated. However, the respective gene abundances differed overall to a greater extent between the three plant development stages than between the inoculation variants.     

Genetic control of the immune response to ferredoxin: linkage and mapping of T cell proliferation and antibody production genes to the MHC of mice

The genetics of the immune response in the mouse were studied by using the antigenically simple, stable, naturally occurring protein ferredoxin (Fd) from Clostridium pasteurianum. The immune status of mice primed and boosted with Fd was assessed by using two parameters of immunity: T cell proliferation and serum antibody production with the ELISA method. In both assay systems, the response has been shown to be H-2 linked: k, b, and s haplotypes respond to Fd, and H-2d mice are nonresponders. It is apparent that different immunoregulatory events modulate the response in the responder strains; these factors become evident in the recombinant analysis of the response and to date an immunoregulatory gene(s) has been mapped to at least the K/I-A subregions. F1 analysis demonstrated a gene dose-dependent response of the strains studied.     

Properties and Nematicide Performance of Avermectins

In 1979, the anthelmintic activity of abamectin, a mixture of avermectins B_1a and B_1b, was first reported. Since then, multiple articles have investigated avermectins' degradation and its efficacy against a wide variety of pests under different conditions and using different modes of application. However, there is a gap in the literature of analysing abamectin properties and its performance as a non‐fumigant nematicide when applied liquid or granular vs. new avenues of application based on seed and seedling treatment. Therefore, this article reviewed literature to discuss the mode of action, environmental aspects, the nematicidal effectiveness of treatment forms and the range of activity to address these topics.