Reducing blood volume requirements for clinical pathology testing in toxicologic studies—points to consider

In preclinical safety assessment, blood volume requirements for various endpoints pose a major challenge. The goal of this working group was to review current practices for clinical pathology (CP) testing in preclinical toxicologic studies, and to discuss advantages and disadvantages of methods for reducing blood volume requirements. An industry‐wide survey was conducted to gather information on CP instrumentation and blood collection practices for hematology, clinical biochemistry, and coagulation evaluation in laboratory animals involved in preclinical studies. Based on the survey results and collective experience of the authors, the working group proposes the following “points to consider” for CP testing: (1) For most commercial analyzers, 0.5 mL and 0.8 mL of whole blood are sufficient for hematology and biochemistry evaluation, respectively. (2) Small analyzers with low volume requirements and low throughput have limited utility in preclinical studies. (3) Sample pooling or dilution is inappropriate for many CP methods. (4) Appropriate collection sites should be determined based on blood volume requirements and technical expertise. (5) Microsampling does not provide sufficient volume given current analyzer and quality assurance requirements. (6) Study design considerations include: the use of older/larger animals (rodents), collection of CP samples before toxicokinetic samples, use of separate subsets of mice for hematology and clinical biochemistry testing, use of a priority list for clinical biochemistry, and when possible, eliminating coagulation testing.     

Capillary gas chromatographic separation of various stimulants

A capillary gas chromatographic (GC) method was developed for the separation of various stimulants of forensic and pharmaceutical interest. The data consist of retention time, relative retention time, corrected retention time, and relative corrected retention time, calculated using ephedrine as reference standard.     

Anabaena sensory rhodopsin: a photochromic color sensor at 2.0 A

Microbial sensory rhodopsins are a family of membrane-embedded photoreceptors in prokaryotic and eukaryotic organisms. Structures of archaeal rhodopsins, which function as light-driven ion pumps or photosensors, have been reported. We present the structure of a eubacterial rhodopsin, which differs from those of previously characterized archaeal rhodopsins in its chromophore and cytoplasmic-side portions. Anabaena sensory rhodopsin exhibits light-induced interconversion between stable 13-cis and all-trans states of the retinylidene protein. The ratio of its cis and trans chromophore forms depends on the wavelength of illumination, thus providing a mechanism for a single protein to signal the color of light, for example, to regulate color-sensitive processes such as chromatic adaptation in photosynthesis. Its cytoplasmic half channel, highly hydrophobic in the archaeal rhodopsins, contains numerous hydrophilic residues networked by water molecules, providing a connection from the photoactive site to the cytoplasmic surface believed to interact with the receptor's soluble 14-kilodalton transducer.     

Suppression of <Emphasis Type="Italic">Papaya ringspot virus</Emphasis> infection in <Emphasis Type="Italic">Carica papaya</Emphasis> with CAP-34, a systemic antiviral resistance inducing protein from <Emphasis Type="Italic">Clerodendrum aculeatum</Emphasis>

CAP-34, a protein from Clerodendrum aculeatum inducing systemic antiviral resistance was evaluated for control of Papaya ringspot virus (PRSV) infection in Carica papaya. In control plants (treated with CAP-34 extraction buffer) systemic mosaic became visible around 20 days that intensified up to 30 days in 56% plants. During this period, CAP-34-treated papaya did not show any symptoms. Between 30 and 60 days, 95% control plants exhibited symptoms ranging from mosaic to filiformy. In the treated set during the same period, symptoms appeared in only 10% plants, but were restricted to mild mosaic. Presence of PRSV was determined in induced-resistant papaya at the respective observation times by bioassay, plate ELISA, immunoblot and RT-PCR. Back-inoculation with sap from inoculated resistant plants onto Chenopodium quinoa did not show presence of virus. The difference between control and treated sets was also evident in plate-ELISA and immunoblot using antiserum raised against PRSV. PRSV RNA was not detectable in treated plants that did not show symptoms by RT-PCR. Control plants at the same time showed a high intensity band similar to the positive control. We therefore suggest that the absence/delayed appearance of symptoms in treated plants could be due to suppressed virus replication.     

Preliminary Studies on Cryopreservation of Vegetative Thalli of Some Economically Important Seaweeds of India

The effects of cryoprotectants and their concentrations, prefreezing temperature, equilibration time, thawing temperature, and the regenerative efficacy of cryopreserved vegetative thalli (apical tips) of Gracilaria corticata J. Agardh., Ulva lobata Duetzing, and Hypnea musiformis (Wulfar) Lamouroux were evaluated. The apical tips were suspended in various cryoprotective solutions and slowly cooled to ?40?C over a period of 4 h. After the slow cooling step, the suspensions were immediately immersed in liquid nitrogen (LN), which were thawed after 2 days. Both U. lobata and H. musiformis survived maximally in 10% DMSO, whereas 10% glycerol was found most suitable for G. corticata. A slow cooling temperature of ?40?C and thawing temperature of 40?C were found most suitable irrespective of the species. The equilibration time of 60 min was found most suitable for G. corticata, while 45 min was sufficient for both H. musiformi and U. lobata. Cryopreserved vegetative thalli were then successfully regenerated, though the survival was considerably reduced up to a period of 28 days after which it was stabilized.     

Biochemical markers of environmental stress tolerance in finger millet [Eleusine coracana (L.) Gaertn.] germplasm of Central Himalayan Region

Genetic Resources and Crop Evolution - Availability of the germplasm of suitable crops for cultivation in environmental stress prone and resource poor terrains is crucial for food security in these...