Powassan Virus: Summer Infection Cycle, 1964

Between May 1, and September 15, 1964, neutralizing antibody to Powassan virus was detected in sera from 163 of 464 forest mammals captured in the Powassan—North Bay area of northern Ontario. These included 159 of 358 groundhogs and four of 43 red squirrels. Acquisition of antibody by juvenile groundhogs occurred principally during July and August. Powassan virus strains were isolated from tick pools containing two to 15 Ixodes cookei per pool which were removed from eight of 91 groundhogs in three townships during May, July and August. Virus was also recovered from blood of two groundhogs during May. Powassan virus was re-isolated from five of six tick pools and two blood clots by inoculation of swine kidney tissue cultures. These findings strongly suggest that during 1964 Powassan virus was maintained in nature by a cycle involving groundhogs and I. cookei ticks.     

Efficient plant regeneration from petiole explants of West Indian gherkin (Cucumis anguria L.) via indirect organogenesis

An efficient protocol for in vitro organogenesis was achieved from callus-derived immature and mature petiole explants of West Indian gherkin (Cucumis anguria L.). Calluses were induced from immature petiole explants excised on 7-day-old in vitro seedlings and mature petiole explants of 40-day-old in vivo plants. The maximum frequency of immature petiole explants (98.0 %) and mature petiole (91.5 %) produced green, compact organogenic callus in Murashige and Skoog (MS) medium with Gamborg (B5) vitamins containing 30 g l^?1 sucrose, 8.0 g l^?1 agar and 4.0 μM naphthalene acetic acid (NAA) with 2.0 μM benzyl amino purine (BAP) after two successive subculture at 11 days interval. Adventitious shoots were produced from the organogenic callus when it was transferred to MSB₅ medium supplemented with 3.0 μM TDZ, 1.0 μM NAA and 0.05 mM L-glutamine with shoot induction frequency of immature petiole 45 shoots and mature petiole 40 shoots per explant. The shoots were excised from callus and elongated in MSB₅ medium fortified with 3.0 μM gibberellic acid (GA₃). Then elongated shoots were rooted in half strength MSB₅ medium supplemented with 3.0 μM indole 3-butyric acid (IBA). Histological analyses of the regeneration process confirmed the indirect organogenesis pattern. Plantlets with well-developed shoot and root systems were successfully acclimatized (95 %) in winter season and exhibited normal morphology and growth characteristics. The survival percentage differed with seasonal variations.     

Effect of Reaction-Finished Solution of Hydrochar (HRFS) Application on Rice Grain Yield and Nitrogen Use Efficiency in Saline Soil

We conducted a pot experiment to examine the feasibility of applying a reaction-finished solution of hydrochar (HRFS) to enhance rice production in a saline soil. With this purpose, HRFS was applied (0, 10, 20, 40, 60, 80 and 100 mL/pot) and rice yield and nitrogen (N) use efficiency (NUE) were determined. HRFS application significantly (P < 0.05) increased rice grain yield by 19.6%–30.0% compared to the control treatment (CKU, with N but without HRFS addition). Moreover, HRFS application promoted plant height and straw biomass of rice. Increases of rice yield were mainly achieved by increases in the number of panicles and grains per panicle. Compared with the CKU treatment, the NUE of HRFS amendments significantly (P < 0.05) increased by 56.3%–71.7%. This indicated that the improvement of NUE was one of the mechanisms to improve rice grain yield with HRFS amendment. The results of regression analysis showed that there was a positive relationship (R²=0.8332) between rice yield and HRFS application rate within an appropriate range. The highest rice yield was recorded with the HRFS application of 40 mL/pot, but a further increase in HRFS application rate appeared to reduce rice yield. Based on the results of this pot study, HRFS application can increase rice yield in a saline soil by regulating its yield components and enhancing NUE. However, impact of HRFS on these variables showed a “dose effect”.     

Impact of vitamin A on high-density lipoprotein-cholesterol and scavenger receptor class BI in the obese rat

Objective: Scavenger receptor class BI (SR‐BI), authentic high‐density lipoprotein (HDL) receptors expressed in liver, are known to play an important role in HDL‐cholesterol (C) metabolism and reverse cholesterol transport. Interestingly, obese rats of WNIN/Ob strain have abnormally elevated levels of serum HDL‐C compared with their lean counterparts. Based on the well‐established role of SR‐B1 in HDL‐C metabolism, it was hypothesized that these obese rats may have an underexpression of hepatic SR‐B1 receptors. In view of the significant role of vitamin A in energy expenditure and obesity, we also tested whether vitamin A supplementation can correct abnormal HDL‐C metabolism. Research Methods and Procedures: To test this hypothesis, 7‐month‐old male lean and obese rats of WNIN/Ob strain were divided into two groups; each group was subdivided into two subgroups consisting of six lean and six obese rats and received diets containing either 2.6 or 129 mg vitamin A/kg diet for 2 months. Results: At the end, obese rats receiving normal levels of vitamin A diet showed high serum HDL‐C and lower hepatic SR‐BI expression levels compared with lean counterparts. Furthermore, chronic dietary vitamin A supplementation resulted in overexpression of hepatic SR‐BI receptors (protein and gene) with concomitant reduction in serum HDL‐C levels in obese rats. Discussion: Thus, our observations highlight the role of vitamin A in reverse cholesterol transport through up‐regulation of hepatic SR‐BI receptors and, thereby, HDL‐C homeostasis in obese rats of WNIN/Ob strain.     

T-Cell Infiltration Correlates with CXCL10 Expression in Ganglia of Cynomolgus Macaques with Reactivated Simian Varicella Virus

Ganglia of monkeys with reactivated simian varicella virus (SVV) contained more CD8 than CD4 T cells around neurons. The abundance of CD8 T cells was greater less than 2 months after reactivation than that at later times and correlated with that of CXCL10 RNA but not with those of SVV protein or open reading frame 61 (ORF61) antisense RNA. CXCL10 RNA colocalized with T-cell clusters. After SVV reactivation, transient T-cell infiltration, possibly mediated by CXCL10, parallels varicella zoster virus (VZV) reactivation in humans.     

Novel Benzoxazine-Based Aglycones Block Glucose Uptake In Vivo by Inhibiting Glycosidases

Glycoside hydrolases catalyze the selective hydrolysis of glycosidic bonds in oligosaccharides, polysaccharides, and their conjugates. β-glucosidases occur in all domains of living organisms and constitute a major group among glycoside hydrolases. On the other hand, the benzoxazinoids occur in living systems and act as stable β-glucosides, such as 2-(2,4-dihydroxy-7-methoxy-2H-1,4-benzoxazin-3(4H)-one)-β-D-gluco-pyranose, which hydrolyse to an aglycone DIMBOA. Here, we synthesized the library of novel 1,3-benzoxazine scaffold based aglycones by using 2-aminobenzyl alcohols and aldehydes from one-pot reaction in a chloroacetic acid catalytic system via aerobic oxidative synthesis. Among the synthesized benzoxazines, 4-(7-chloro-2,4-dihydro-1H-benzo[d][1,3]oxazin-2-yl)phenol (compound 7) exhibit significant inhibition towards glucosidase compared to acarbose, with a IC₅₀ value of 11.5 µM. Based upon results generated by in silico target prediction algorithms (Naïve Bayesian classifier), these aglycones potentially target the additional sodium/glucose cotransporter 1 (where a log likelihood score of 2.70 was observed). Furthermore, the in vitro glucosidase activity was correlated with the in silico docking results, with a high docking score for the aglycones towards the substrate binding site of glycosidase. Evidently, the in vitro and in vivo experiments clearly suggest an anti-hyperglycemic effect via glucose uptake inhibition by 4-(7-chloro-2,4-dihydro-1H-benzo[d][1,3]oxazin-2-yl)phenol in the starved rat model. These synthetic aglycones could constitute a novel pharmacological approach for the treatment, or re-enforcement of existing treatments, of type 2 diabetes and associated secondary complications.     

Effect of Experimental Temperature on the Permeation of Model Diffusants Across Porcine Buccal Mucosa

The influence of experimental temperature on the permeability of model diffusants across porcine buccal mucosa was investigated in vitro. The permeability increased significantly as the experimental temperature was increased in increments of approximately 7°C. It was observed that the apparent permeability and temperature were related by an exponential relationship that conformed to the Arrhenius equation. Diffusants with higher lipophilicities—buspirone and bupivacaine—had lower activation energies for diffusion when compared to hydrophilic diffusants—antipyrine and caffeine. The activation energy for diffusion of the model diffusants decreased linearly with increasing distribution coefficients across porcine buccal mucosa. The results suggested that the buccal mucosa acts as a stronger barrier to the diffusion of hydrophilic diffusants than the lipophilic ones. The log-linear relationship between permeability and temperature indicates that temperature should be carefully controlled in diffusion experiments. These results also point to the possibility of developing heat-generating buccal delivery devices, especially for hydrophobic diffusants.