Ultrastructure of sporozoites and zoites of Hammondia heydorni

The ultrastructure of sporozoites and zoites of Hammondia heydorni was studied in cultured bovine cells. In addition to ultrastructural features typical of coccidian parasites, H. heydorni sporozoites and zoites contain rhoptries that are located posteriorly as well as anteriorly. Also, sporozoites contain a posteriorly located crystalloid body (1.2 micron in diameter); a small crystalloid body (0.5 micron in diameter) was occasionally seen in the anterior end. Zoites resulting from the 1st division of endodyogeny contain a posteriorly located crystalloid body, which is absent in zoites formed by subsequent divisions. Zoites contain posteriorly located amylopectin granules and a relatively large anterior vacuole which is not present in sporozoites. During penetration, the host cell plasmalemma ballooned laterally around the sporozoite creating a large cavity, which later disappeared. Sporozoites and zoites undergoing cell penetration usually exhibit partially empty anterior rhoptries; no changes occur in posterior rhoptries. Lysosomes fuse with the parasitophorous vacuole surrounding killed sporozoites but not live sporozoites.     

Multiwalled Carbon Nanotube-Superoxide Dismutase Conjugate Towards Alleviating Induced Oxidative Stress

Superoxide dismutase (SOD), an antioxidative enzyme, was covalently immobilized onto oxidized multi-walled carbon nanotubes (MwCNTs) using diimide activated amidation reaction. MwCNT(SOD) conjugates with high aqueous dispersible nature were obtained and characterized further using field emission scanning electron microscopy and Fourier transformed infrared spectroscopy. The synthesized conjugates even after 96 h incubation time period were found to retain significant superoxide anion scavenging activity. The synthesized MwCNT(SOD) conjugate were found to no significant toxicity in limited doses. Conditions for oxidative stress in human skin HaCat cells were optimized using H₂O₂ (1 mM) as an external stress factor and subsequently anti-oxidative response of synthesized MwCNT(SOD) conjugate was analyzed. Upon incubation with oxidative stress induced HaCat cells, MwCNT(SOD) conjugates were found to alleviate the increased oxidative stress indicating its enhanced uptake and efficient antioxidative activity. Low level of reactive oxygen species and increased SOD activity in HaCat cells post treatment with MwCNT(SOD) conjugate further confirms the antioxidative activity of SOD enzyme in conjugation with MwCNTs which acts as an efficient intracellular drug delivery vehicles.     

The impact of symbolism on immunogenetics: an application to HLA

The genes coding for the class I human lymphocyte antigens (HLA) are located on chromosome 6. These antigens are involved with the immunological interaction between cells. In some immunogenetic systems, such as HLA in humans, genes are defined by antibody/antigen reaction and are denoted by single symbolic identifiers. This symbolization assumes a one-to-one correspondence between antibodies, antigens and genes. Recent molecular studies, however, suggest that HLA antibody/antigen reaction is complex and most HLA class I specific antibodies may not uniquely identify a single allelic product. Where cross-reactivity is present in an immunogenetic system it is important to label each reagent with symbols corresponding to all genes coding for antigens with which the reagent will react. The problems of cross-reactive groups and unexplained linkage relations may be elucidated by the redefinition and clarification of certain HLA antigens. A computer program can suggest such labelling schemes using input given by phenotype reaction patterns with a panel of reagents. When this program was applied to data on the class I HLA antigens a genetic model was suggested that differs somewhat from the currently accepted model. The new model is able to predict what would appear as linkage relations in the accepted model. Our methodology can provide alternate models to guide in typing cloned genes in terms of the HLA locus and alleles.     

A Study of Sensitivity Improved Probe Using Hyperbolic Metamaterial for Optical Fiber SPR (OFSPR)-based Refractive Index Sensor

Plasmonics - In this work, we theoretically study the plasmonic behavior of Ag and Au with a hyperbolic metamaterial (HMM) and propose a numerical simulation of a D-shaped surface plasmon resonance...     

Cyclic variation in rats's uterine fluid phosphatase level after administration of lyndral (17 alpha-ethinyl estradiol).

An oral administration of antifertility drug Lyndral (17 alpha-ethinyl estradiol) at doses 5 micrograms/rat/a week for 3 consecutive weeks altered the internal biochemical milieu of uterus, showing a cyclic variation in both acid and alkaline phosphatase of the uterine fluid with high levels being present at proestrus and estrus in control rats. In Lyndral treated rats acid phosphatase showed a tendency to increase in estrus and metestrus rats, whereas alkaline phosphatase increased significantly during proestrus and estrus stages of the cycle. All these altered phosphatase levels in uterine fluid, after Lyndral treatment, gives some insight into the hormonal sensitiveness of these enzymes.     

Do sister forks of bidirectionally growing replicons proceed at unequal rates?

DNA fibre autoradiography in different tissues of the rodents Bandicota bengalensis and Nesokia indica reveals a high frequency of such bidirectionally replicating replicons whose sister 'hot' tracks are of unequal size. These results suggest intrarepliconic difference in the rates of fork migration in the two directions.     

National seroprevalence of Toxoplasma gondii in pigs

Serum samples from 11,842 commercial pigs killed in 1983-1984 throughout the United States were tested for anti-Toxoplasma gondii antibodies by the agglutination test in dilutions of 1:25, 1:50, and 1:500. Anti-T. gondii antibodies were found in 23.9% of pigs. At dilutions of 1:25, 1:50, and 1:500, 13.5%, 6.9%, and 3.5% were serologically positive, respectively. The prevalence of anti-T. gondii antibodies was higher in breeder pigs (42%) than in market pigs (23%). These results indicate that anti-T. gondii antibodies are widespread in the national swine herd.