Studies in the Physiology of Leaf Growth: I. The Effect of Various Accessory Growth Factors on the Growth of the first Leaf of isolated Stem Tips of Rye

RESP-254

Studies in the Physiology of Leaf Growth: II. Growth and Structure of the First Leaf of Rye when cultivated in Isolation or attached to the Intact Plant

RESP-256

Passatempo Virus, a Vaccinia Virus Strain, Brazil

Passatempo virus was isolated during a zoonotic outbreak. Biologic features and molecular characterization of hemagglutinin, thymidine kinase, and vaccinia growth factor genes suggested a vaccinia virus infection, which strengthens the idea of the reemergence and circulation of vaccinia virus in Brazil. Molecular polymorphisms indicated that Passatempo virus is a different isolate

Molecular and biochemical characterisation of a novel mutation in POLG associated with Alpers syndrome

<p>Abstract</p> <p>Background</p> <p>DNA polymerase γ (<it>POLG</it>) is the only known mitochondrial DNA (mtDNA) polymerase. It mediates mtDNA replication and base excision repair. Mutations in the <it>POLG </it>gene lead to reduction of functional mtDNA (mtDNA depletion and/or deletions) and are therefore predicted to result in defective oxidative phosphorylation (OXPHOS). Many mutations map to the polymerase and exonuclease domains of the enzyme and produce a broad clinical spectrum. The most frequent mutation p.A467T is localised in the linker region between these domains. In compound heterozygote patients the p.A467T mutation has been described to be associated amongst others with fatal childhood encephalopathy. These patients have a poorer survival rate compared to homozygotes.</p> <p>Methods</p> <p>mtDNA content in various tissues (fibroblasts, muscle and liver) was quantified using quantitative PCR (qPCR). OXPHOS activities in the same tissues were assessed using spectrophotometric methods and catalytic stain of BN-PAGE.</p> <p>Results</p> <p>We characterise a novel splice site mutation in <it>POLG </it>found <it>in trans </it>with the p.A467T mutation in a 3.5 years old boy with valproic acid induced acute liver failure (Alpers-Huttenlocher syndrome). These mutations result in a tissue specific depletion of the mtDNA which correlates with the OXPHOS-activities.</p> <p>Conclusions</p> <p>mtDNA depletion can be expressed in a high tissue-specific manner and confirms the need to analyse primary tissue. Furthermore<it>, POLG </it>analysis optimises clinical management in the early stages of disease and reinforces the need for its evaluation before starting valproic acid treatment.</p

Skin Lesions on Common Bottlenose Dolphins (Tursiops truncatus) from Three Sites in the Northwest Atlantic, USA

Skin disease occurs frequently in many cetacean species across the globe; methods to categorize lesions have relied on photo-identification (photo-id), stranding, and by-catch data. The current study used photo-id data from four sampling months during 2009 to estimate skin lesion prevalence and type occurring on bottlenose dolphins (Tursiops truncatus) from three sites along the southeast United States coast [Sarasota Bay, FL (SSB); near Brunswick and Sapelo Island, GA (BSG); and near Charleston, SC (CHS)]. The prevalence of lesions was highest among BSG dolphins (P = 0.587) and lowest in SSB (P = 0.380), and the overall prevalence was significantly different among all sites (p<0.0167). Logistic regression modeling revealed a significant reduction in the odds of lesion occurrence for increasing water temperatures (OR = 0.92; 95%CI:0.906–0.938) and a significantly increased odds of lesion occurrence for BSG dolphins (OR = 1.39; 95%CI:1.203–1.614). Approximately one-third of the lesioned dolphins from each site presented with multiple types, and population differences in lesion type occurrence were observed (p<0.05). Lesions on stranded dolphins were sampled to determine the etiology of different lesion types, which included three visually distinct samples positive for herpesvirus. Although generally considered non-fatal, skin disease may be indicative of animal health or exposure to anthropogenic or environmental threats, and photo-id data provide an efficient and cost-effective approach to document the occurrence of skin lesions in free-ranging populations

Dolichol: A Component of the Cellular Antioxidant Machinery

Dolichol, an end product of the mevalonate pathway, has been proposed a biomarker of aging, but its biological role, not to mention its catabolism, has not been fully understood. UV-B radiation was used to induce oxidative stress in isolated rat hepatocytes by the collagenase method. Effects on dolichol, phospholipids-bound polyunsaturated fatty acids (PL PUFA) and known lipid soluble antioxidants [coenzyme Q (CoQ) and α-tocopherol] were studied. The increase in oxidative stress was detected by a probe sensitive to reactive oxygen species (ROS). Peroxidation of lipids was assessed by measuring the release of thiobarbituric acid reactive substances (TBARS). Dolichol, CoQ and α-tocopherol were assessed by high-pressure liquid chromatography (HPLC), PL PUFA by gas-liquid chromatography (GC). UV-B radiation caused an immediate increase in ROS as well as lipid peroxidation and a simultaneous decrease in the levels of dolichol and lipid soluble antioxidants. Decrease in dolichol paralleled changes in CoQ levels and was smaller than that in α-tocopherol. The addition of mevinolin, a competitive inhibitor of the enzyme 3-hydroxy-3-methylglutaryl CoA reductase (HMG-CoAR), magnified the loss of dolichol and was associated with an increase in TBARS production. Changes in PL PUFA were minor. These findings highlight that oxidative stress has very early and similar effects on dolichol and lipid soluble antioxidants. Lower levels of dolichol are associated with enhanced peroxidation of lipids, which suggest that dolichol may have a protective role in the antioxidant machinery of cell membranes and perhaps be a key to understanding some adverse effects of statin therapy