Gene-conversion in rabbit B-cell ontogeny and during immune responses in splenic germinal centers

Combinatorial diversity is limited in rabbits because only a few V(H) genes rearrange. Most diversification of the primary repertoire is generated by somatic hypermutation and gene conversion-like changes of rearranged V(H) in B cells that migrate to appendix and other gut associated lymphoid tissues (GALT) of young rabbits. The changes are referred to as gene conversion-like because the non-reciprocal nature of the alterations introduced has not yet been demonstrated. There are many similarities between rabbits and chickens in how their B cells develop and diversify their repertoires. However, although the majority of rabbit B cells may have rearranged and diversified their V genes early in life, some B cells in adult rabbits have rearranged VH sequences that are identical or nearly identical to germline sequences. We found these cells in splenic germinal centers (GC) on days 7 and 10 after immunization of normal adult rabbits with DNP-BGG. By day 15, all rearranged V(H) sequences were diversified. We find an overall pattern of splenic precursor cells whose germline or near germline sequences change both by gene conversion and point mutations during early divisions and mainly by point mutations during later divisions. These events, in parallel with diversification of light chain sequences, may produce the diverse combining sites that serve as substrates for further affinity maturation by selection either within GC or later among emigrant cells in sites such as bone marrow. Some of the sequences altered by gene conversion in splenic germinal centers may also produce new members of the B-cell repertoire in adult rabbits comparable to those produced in GALT of neonatal rabbits.     

The radiosensitizing effect of the aurora kinase inhibitors,ENMD‐2076, on canine mast cell tumours in vitro

ENMD‐2076 is an aurora kinase inhibitor that also has multi‐target tyrosine kinase inhibitor properties. In this study, the mRNA and the protein expression of aurora‐A and aurora‐B were evaluated in three canine mast cell tumour cell lines. Dose‐dependent cytotoxicity was seen in the cells treated, and it affected the cell cycle with cells in the G2/M phase being selectively killed. The cells were also evaluated for radiosensitivity with/without ENMD‐2076, and radiosensitization was seen after 3 Gy and 6 Gy exposures with ENMD‐2076 for 48 h. Protein expression of caspase‐3 was gradually increased, and the expression intensity was highest at 24 h post irradiation in cells without ENMD‐2076 treatment, which indicates that radiation exposure with ENMD‐2076‐induced cell death faster than radiation treatment alone. Our study results suggest the potential usefulness of treating canine mast cell tumours with aurora kinase inhibitors alone or in conjunction with radiation therapy.     

Effects of local anaesthesia of 4 to 8 hours duration on the acute cortisol response to scoop dehorning in calves

Objective To determine the effect of a long-acting local anaesthetic on the plasma cortisol response in calves dehorned using a scoop.
Design A physiological study with controls.
Procedure Seventy female calves, 3 to 4 months old, were divided into seven groups and dehorned by scoop with or without a long acting local anaesthetic (bupivacaine) which provides local anaesthesia for 3 to 4 h. In some treatment groups the local anaesthetic was given a second time, after 4 h, to give 8 h of anaesthesia. Blood samples were taken before and for 9 h after treatment and plasma cortisol concentrations were measured.
Results Scoop dehorning caused a marked rise in plasma cortisol concentration, which returned to pre-dehorning values after 7 h. The cortisol concentrations of calves given bupiva-caine were similar to those of control animals for 4 h after dehorning, but then a significant and protracted rise occurred, with concentrations returning to pretreatment values at about 9 h after dehorning. In calves given a second treatment of bupivacaine 4 h after dehorning, the plasma cortisol concentration remained similar to control values for 8 h after dehorning but then increased sharply.
Conclusions During its period of activity long-acting local anaesthetic prevented the rise usually seen after scoop dehorning in plasma cortisol concentrations; by inference it also alleviated the pain-induced distress caused by this procedure. However, when its effects had worn off the plasma cortisol values rose sharply indicating that animals still experienced pain-induced distress despite local anaesthetic being administered.     

An appraisal of the problems in classifying saline-sodic soils of the indo-gangetic plain in NW India

Most of the salt-affected soils of the Indo-Gangetic plain in NW India do not find suitable places in the 1970 U.S. system of soil classification. According to the current class definitions, soils with high salts, ESP, pH, chromas and yellower hues key out as Typic or Aquic Calciorthids, Camborthids and Haplustalfs which does not spell out their saline-sodic nature. For land-use recommendations, the authors believe it will be useful to set these soils apart at some high categoric level in the system.It is proposed that the structural requirements for the natric horizon be modified to include horizons with high ESP (? 40) but having simple blocky structure with or without tongues of eluvial material. New subgroups, viz. Natric, within the orders of Inceptisols, Alfisols and Aridisols is suggested for the high sodium-saturated soils lacking natric horizons. For similar practical considerations, the high concentrations of salts in soils when associated with high ESP pose problems in leaching and consequently new subgroups, viz. Salic and Salic Natric, within the orders of Aridisols and Alfisols are suggested.The modifications proposed not only place more emphasis on the saline-sodic nature of these soils but also result in better groupings for practical land use.     

Studies of some soils in the NW Himalayas and the highlands of India

A reconnaissance soil survey of the NW Himalayan mountains and highlands in the Lahul valley (Himachal Pradesh) was undertaken and five soil profiles from different regions and supporting different vegetation, representing both virgin and cultivated lands, were studied, described and classified in two major soil series, viz. Krozing and Shainsha. The clay fraction of these soils consists of illite and chlorite with minor amounts of kaolinite and traces of swelling chlorite and/or montmorillonite. The removal of amorphous material by a dithionite citrate buffer has been found to be imperative.According to the current definitions, these frigid like high mountain soils having an epipedon on limit with mollic qualify for Dystric Eutrochrepts, which does not depict the reality. Therefore, they have been logically classified, by defining new subgroups of Cryic, Mollic and Cryollic within Eutrochrepts, as Dystric Cryic Eutrochrepts (Shainsha series) and Dystric Cryollic Eutrochrepts (Krozing series). The proposed classification is supported by their geographic situation between Eutrochrepts and/or Hapludolls (in lower valleys) and Cryochrepts and/or Haploborolls (on higher hills).     

Fabrication of electrospun Poly L-lactide and Curcumin loaded Poly L-lactide nanofibers for drug delivery

The present work reports the preparation of Poly L-Lactide (PLLA) and Curcumin loaded Poly L-Lactide (CPLLA) nanofibers by electrospinning. A series of PLLA solution (12 wt %) and C-PLLA (12 wt % PLLA) solution containing Curcumin (0.5 wt % and 1 wt %)) were electrospun into nanofibers. SEM images showed the average diameter of PLLA and C-PLLA in the range of 50?C200 nm. The TEM images showed the dispersion of Curcumin on C-PLLA nanofibers. The XRD pattern indicated decreases of crystallinity with the increase in the amount of Curcumin. The characteristic peak of Curcumin was confirmed by FTIR. The TGA results showed the degradation of PLLA and C-PLLA close to 300 °C. The percentage porosity and the contact angle of PLLA were found to be 90.2 % and 115±3 ° with deionised water, respectively. The water uptake percentage was found to be 17.6 %. The percentage cumulative release of Curcumin at the end of 8th day for 0.5 and 1.0 wt % formulations was 81.4±1.3 and 86.7±1.7 % respectively. The in-vitro biological cytotoxicity studies were performed using C6 glioma cells and NIH 3T3 fibroblast by MTT assay and SEM analysis.     

Genetic analysis and conservation of endangered medicinal tree species <Emphasis Type="Italic">Taxus wallichiana</Emphasis> in the Himalayan region

Taxus wallichiana is one of the most important medicinal tree species of the Himalayan region. Leaf and bark of the species yield an important drug called taxol, which is used for treatment of many types of cancer. There is a serious threat to the existence of the species due to over exploitation in its native habitat. Adequate information on the nature and the extent of genetic diversity in this important species is required for developing suitable strategy for its conservation. Random amplified polymorphic DNA (RAPD) and amplified fragment length polymorphism (AFLP) were used to assess genetic variation in nine natural populations of T. wallichiana from western part of the Himalayan ranges. Both the markers revealed low genetic diversity in these populations. Average heterozygosity for AFLP and RAPD were 0.3715 and 0.3072, respectively. Φ_ST values derived from molecular variance were 0.0855 and 0.1005 for AFLP and RAPD, respectively, whereas the corresponding G_ST values were 0.1796 and 0.2140. Most part of the genetic variation was present within the populations. However, between population variation was low but statistically significant, which suggested that the sampled populations might not constitute a single panmictic population. Cluster analysis and Mantel’s correlation revealed that genetic differentiation broadly followed geographic distribution of the populations. T. wallichiana thus urgently needs to be conserved using both in situ and ex situ conservation approaches.