Microfluidic Device for Cell Trapping with Carbon Electrodes Using Dielectrophoresis.

Dielectrophoresis (DEP) devices have proven to be one of the most promising tools to transport, accumulate and sort various cells and particles. The major challenge in the development of DEP devices is the high cost, low yield using Microelectromechanical systems (MEMS). In this paper, we demonstrate a facile, low-cost, and high-throughput method of constructing continuous-flow DEP devices using screen-printing technology. Much literature has concluded that the use of carbon electrodes provides more cost effective and more durable DEP devices than metal electrodes. More efficient devices not only need to be constructed from a low cost material but also from an inexpensive fabrication technique. In this study, we used yeast cells as model cells to perform a comparative study on trapping efficiency of carbon and gold electrode DEP devices. We have proposed, the sealing of carbon DEP device with glass, instead of PDMS, using adhesive bonding technique which not only reduce the leakage problem but also increases the device performance. We also report the biocompatibility analysis of carbon paste and the results indicates its usefulness in eventual studies involving carbon-MEMS devices.

Effect of temperature on transtadial transmission of Theileria annulata in Hyalomma anatolicum anatolicum ticks.

The effect of temperature on the transtadial transmission of Theileria annulata in Hyalomma anatolicum anatolicum was studied. Variation in temperature (4-40 degrees C) had a significant effect on moulting rate of the ticks and transmission of theilerial parasites from nymphs to resultant adults. The temperatures above 40 degrees C and below 12 degrees C prevented moulting. Maximum infection levels were obtained in salivary glands of adult ticks when the infected engorged nymphs were incubated at 24-28 degrees C. The infection rate in salivary glands was assessed using a methyl green pyronin technique.

Prophylactic efficacy of buparvaquone in experimentally induced Theileria annulata infection in calves.

The antitheilerial activity of buparvaquone (BW 720C) was evaluated in experimentally induced Theileria annulata infections in cross-bred male calves. T. annulata infections were induced by injecting a suspension of infected ground tick tissue suspension (GUTTS) equivalent to two ticks subcutaneously into each calf. Buparvaquone at a dose of 2.5 mg kg-1 body weight was given as a single injection (intramuscularly) on Day 0 (Group 1), Day 8 (Group 2) and Day 12 (Group 3) post-infection. The animals in Groups 4 and 5 were untreated and challenged controls, respectively. All of the recovered animals from Groups 1-4 were challenged with a lethal dose of T. annulata at 6 weeks post-infection. The immunized animals were resistant to the homologous challenge, which killed three of four control animals (Group 5); the controls showed typical antemortem and post-mortem lesions of theileriosis.

Changes in blood chemical components during experimentally induced Theileria annulata infections in cattle.

During the course of infection of calves with Theileria annulata levels of glucose, calcium, proteins, phosphorus, magnesium and potassium decreased and those of bilirubin, cholesterol and alkaline phosphatase increased with no changes in sodium and acid phosphatase levels. Several of these biochemical alterations have been explained in relation to the injury to the liver and other organs.

Influence of dietary aflatoxin on Eimeria uzura infection in Japanese quail (Coturnix coturnix japonica).

A study was conducted to assess the influence of dietary aflatoxin on Eimeria uzura in Japanese quail (Coturnix coturnix japonica). Quail receiving 1 part per million (ppm) of dietary aflatoxin B1 and inoculated with 10(5) sporulated oocysts of E. uzura gained significantly less weight than chicks receiving either aflatoxin or coccidia alone. Increased morbidity, mortality and decreased efficiency of feed utilization were also evident. The combination of E. uzura infection and aflatoxicosis resulted in reduction in packed cell volume (PCV) and haemoglobin (Hb). The combination of E. uzura infection and aflatoxicosis in Japanese quail may influence the course of coccidial infection due to the additive effects of aflatoxin.

Interaction between Eimeria uzura infection and aflatoxicosis in Japanese quail (Coturnix coturnix japonica).

The clinical signs and gross lesions caused by Eimeria uzura (10(5) oocysts) in Japanese quail (Coturnix coturnix japonica) exhibited little or no influence in the face of intercurrent dietary aflatoxicosis (1 p.p.m. of aflatoxin B1 from Day 0 to 55). Similarly, no significant differences in the mucosal morphology of the intestine were evident histologically between the two groups of Japanese quail. The nervous signs of ataxia, leg weakness, incoordination of movement, torticollis and terminal opisthotonos were toxin-induced manifestations. In the aflatoxic quail, hypoplastic changes and selective depletion of lymphocytes were more prominent in the bursa of fabricius. Increased relative mean weights of liver, kidney, spleen, crop, proventriculus and gizzard were observed in birds due to aflatoxin sensitivity. The combination of E. uzura infection and aflatoxicosis in Japanese quail may cause significant weight loss, and increased oocyst production and reproductive potential.

Effect of Mycobacterium phlei on the development of immunity to Babesia bigemina.

The immunomodulatory role of Mycobacterium phlei against intracellular blood protozoan Babesia bigemina was demonstrated following experimental immunisation and challenge in bovine calves. A lysate of erythrocytes infected (6 x 10(9)) with B. bigemina was used as a source of dead antigen either with Freund's complete adjuvant (FCA) or with a trypsinised culture of M. phlei as a non-specific immunomodulation (NSI) agent with appropriate controls. Following virulent challenge with B. bigemina infected erythrocytes (1 x 10(7)), the NSI printed calves showed 100% protection, while the dead antigen alone with FCA afforded 75% protection. The protective status of the immunising regimes was studied by clinicopathological parameters and assessment of humoral and cell-mediated immune responses. The role of babesial dead antigen and the effects of M. phlei on the development of immunity to B. bigemina is discussed.

Efficacy of Butalex in field cases of bovine theileriosis--short communication.

Lactating cows, heifers, calves and young bulls suffering from naturally occurring bovine tropical theileriosis were treated with Butalex (buparvaquone). As a result of treatment, the clinical signs disappeared and the previously depressed milk yield of cows increased. No mortality was recorded and all the animals recovered.

Theileria annulata infection in neonatal bovine calves.

On an organized farm in India, 70 out of 79 cows expected to calve within 30 days revealed the presence of Theileria annulata schizonts and/or piroplasms in their peripheral blood. Similarly, 33 out of 59 calves borne to the above cows also exhibited T. annulata schizonts on day less than 1 to day 19 post partum. The cows and calves were free from Hyalomma anatolicum, an established vector of T. annulata, during the course of study in the winter months, when the activity of ticks is reduced to the minimum. The infection appears to have taken place antenatally.

Complete Genome Sequence of Potato leafroll virus Isolates Infecting Potato in the Different Geographical Areas of India Shows Low Level Genetic Diversity.

Five Potato leafroll virus (PLRV) isolates were collected from five states representing different potato growing parts of India. The ssRNA genome sequences of these isolates were determined. The genome comprised of 5,883 nucleotides and deduced genome organization resembled other PLRV isolates. About 97.6-98.7 % similarities was observed within the Indian isolates and were more close to European, Canadian, African, American and Czech isolates (95.8-98.6 %) than to an Australian isolate (92.9-93.4 %). These isolates were 43.7-53.1 % similar to other poleroviruses and 29.1-29.3 % to Barley yellow dwarf virus, a luteovirus. Out of five isolates, the isolate PBI-6 was recombinant one as detected by RDP3 software. Multiple sequence alignment of nucleotide and amino acid sequences of different ORFs indicated that the ORF 3 and ORF 4, corresponding to coat protein and movement proteins are more conserved than other ORFs. Amino acid changes specific to Indian isolates were observed and it was more in ORF 2 than in ORF 0, ORF 3 and ORF 4. This is the first report of complete genome sequence of PLRV isolates from India, which reveals low level genetic diversity.

Bioconversion of acrylonitrile to acrylamide using polyacrylamide entrapped cells of Rhodococcus rhodochrous PA-34.

The nitrile hydratase (NHase) of Rhodococcus rhodochrous PA-34 catalyzed the conversion of acrylonitrile to acrylamide. The resting cells (having NHase activity) (8 %; 1 mL corresponds to 22 mg dry cell mass, DCM) were immobilized in polyacrylamide gel containing 12.5 % acrylamide, 0.6 % bisacrylamide, 0.2 % diammonium persulfate and 0.4 % TEMED. The polyacrylamide entrapped cells (1.12 mg DCM/mL) completely converted acrylonitrile in 3 h at 10 °C, using 0.1 mol/L potassium phosphate buffer. In a partitioned fed batch reactor, 432 g/L acrylamide was accumulated after 1 d. The polyacrylamide discs were recycled up to 3×; 405, 210 and 170 g/L acrylamide was produced in 1st, 2nd and 3rd recycling reactions. In four cycles, a total of 1217 g acrylamide was produced by recycling the same mass of entrapped cells.