X-ray diffractometry and electron microscopy of DNA from Bacillus subtilis bound on clay minerals     

M. Khanna  M. Yoder  L. Calamai  G. Stotzky 《Sciences of Soils》1998,3(1):1-10

DNA bound on clay minerals, sand, and humic acids has been shown, both in vitro and in situ, to be capable of transforming bacteria and to resist degradation by nucleases, which could result in the crypticity of genes in soil and other natural habitats. To determine where DNA is bound on clay minerals, which may help to explain how bound DNA becomes resistant to degradation by nucleases but retains the ability to transform competent cells, chromosomal DNA from Bacillus subtilis bound on montmorillonite (M) and kaolinite (K) was examined by X-ray diffractometry and transmission and scanning electron microscopy. X-ray diffraction analysis showed that the basal spacings of M and K were not altered, indicating that this DNA did not significantly intercalate the clays. Scanning and transmission electron microscopy showed that the binding of this DNA was primarily on the edges of M and K, although some binding was also apparent on the planar surfaces. Based on the results of these studies, it is postulated that:

1.	extension from the edges of the clays enables the unbound end of DNA to interact with receptor sites on competent cells and result in their transformation; and
2.	binding on clays alters the electron distribution and/or conformation of DNA, which reduces its hydrolysis by nucleases.

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Retention of sulphate by an acid brown earth and its relationship with the atmospheric input of sulphur to forest vegetation     

K. J. Meiwes  P. K. Khanna  B. Ulrich 《植物养料与土壤学杂志》1980,143(4):402-411

In soil samples of an acid brown earth the sulphate retention was studied as a function of sulphate concentration and pH of the soil solution. The soil under two forest covers (spruce and beech), has. shown distinct variation in its sulphate retention characteristics. The soil under spruce, due to the greater filtering action of vegetation, receives higher inputs of sulphate und hydrogen ions and shows higher amounts of retained sulphate. The uppermost 10 cm soil samples from both sites do not retain any sulphate when its concentration in the solution phase is increased. In samples from greater depths, the retention of sulphate is accompanied by a change in pH of the soil solution. The maximum retention occurs at pH 4, and soil samples from under beech retain higher amounts of sulphate than those under spruce for a corresponding depth and similar conditions of H⁺ addition. Desorption of newly retained sulphate followed in some samples the concentration relationship found in the adsorption experiment without any hysteresis, but the desorption of initially present sulphate indicates that two different forms of sulphate, weakly-and tightly-bound, may be existing in these soils.  相似文献   

Defining the relation between soil water content and net nitrogen mineralization   总被引：2，自引：0，他引：2  

K. I. Paul    P. J. Polglase    A. M. O'Connell  J. C. Carlyle  P. J. Smethurst  & P. K. Khanna 《European Journal of Soil Science》2003,54(1):39-48

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Blood gases and acid-base status of normal Zebu cattle     

Kuldip K. Mirakhur  A. K. Khanna  B. Prasad 《Veterinary research communications》1985,9(1):303-308

Nine adult bullocks were used for this study. The auricular artery was found to be convenient for collecting arterial blood samples. Samples were also taken from the jugular and auricular veins. The mean values of blood gas analyses from these animals are recorded.  相似文献   

Blood gases and acid-base status of normal Zebu cattle     

K K Mirakhur  A K Khanna  B Prasad 《Veterinary research communications》1985,9(4):303-308

Nine adult bullocks were used for this study. The auricular artery was found to be convenient for collecting arterial blood samples. Samples were also taken from the jugular and auricular veins. The mean values of blood gas analyses from these animals are recorded.  相似文献   

A Survey of Evidence in the Journal of Veterinary Internal Medicine Oncology Manuscripts from 1999 to 2007     

A. Sahora  C. Khanna 《Journal of veterinary internal medicine / American College of Veterinary Internal Medicine》2010,24(1):51-56

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First report of Fusarium solani causing wilt of Melia dubia          下载免费PDF全文

A. Pandey  R. Juwantha  S. Chandra  A. Kumar  P. Kannojia  D. Khanna  S. Arora  V. D. Dwivedi  S. Pandey 《Forest Pathology》2018,48(1)

Melia dubia, a multipurpose tree species, is gaining importance to meet the demand supply gap of timber, plywood and pulpwood . In June 2016, a serious outbreak of wilt disease was observed in M. dubia seedlings planted in the Central Nursery of Forest Research Institute (FRI), Dehradun, India. The disease led to the destruction of one hundred thousand (100,000) seedlings. Earlier in June 2012, serious wilting of M. dubia seedlings was observed in Haryana, India. The pathogen was identified as Fusarium solani following standard laboratory procedures and sequence analysis of the internal transcribed spacer (ITS) region of the ribosomal DNA (rDNA). The pathogenicity of three isolates has been proved under greenhouse conditions. This is the first report of F. solani causing wilt of M. dubia.  相似文献   

Prospective Study of Thrombospondin-1 Mimetic Peptides, ABT-510 and ABT-898, in Dogs with Soft Tissue Sarcoma     

AI Sahora  AW Rusk  J Henkin  EM McKeegan  Y Shi  C Khanna 《Journal of veterinary internal medicine / American College of Veterinary Internal Medicine》2012,26(5):1169-1176

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Evaluation of the oral antimitotic agent (ABT-751) in dogs with lymphoma     

Silver M  Rusk A  Phillips B  Beck E  Jankowski M  Philibert J  Hahn K  Hershey E  McKeegan E  Bauch J  Krivoshik A  Khanna C 《Journal of veterinary internal medicine / American College of Veterinary Internal Medicine》2012,26(2):349-354

Background

ABT‐751 is a novel orally available antimitotic agent that targets microtubule polymerization. This mechanism may suggest potential activity in canine lymphoma.

Objective

Determine a maximum tolerated dose for ABT‐751, and assess long‐term tolerability and activity in canine lymphoma.

Animals

Thirty dogs with newly diagnosed (n = 19) or relapsed (n = 11) non‐Hodgkin's lymphoma.

Methods

Dogs (n = 11) were enrolled in a rapid dose escalation study to define the maximum tolerated dose. Upon definition of a maximally tolerated dose, a cohort expansion of 19 dogs allowed verification of long‐term tolerability and assessment of activity. Study endpoints in the cohort expansion included chronic tolerability, response rate, response duration, and time to progression. Additional endpoints included serum pharmacokinetics, lymph node drug concentrations, and changes in circulating endothelial cells.

Results

The maximum tolerated dose of ABT‐751 was 350 mg/m² PO q24h. Dose‐limiting toxicities included vomiting and diarrhea, which resolved with a schedule adjustment to 350 mg/m² PO q48h. ABT‐751 was consistently detected in lymphoma tissue samples from dogs treated at or above the maximum tolerated dose. In the cohort expansion, objective responses were seen in 3/15 (20%) dogs with a response duration ranging from 21 to 111 days. Decreases in circulating endothelial cells were seen in 10 dogs at day 7 (2 responding dogs and 8 nonresponding dogs).

Conclusion

ABT‐751 was well tolerated at 350   mg/m² PO q24h for 7 days and then q48h thereafter. Activity of ABT‐751 suggested a rationale for additional studies of ABT‐751 as part of a combination chemotherapy protocol for lymphoma or other canine cancers.  相似文献   

First report of bacterial blight caused by Acidovorax avenae ssp. avenae associated with finger millet seeds from Uganda     

P. J. Mudingotto  M. S. Veena  C. N. Mortensen 《Plant pathology》2002,51(3):396-396

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