Reduced Pyridine Nucleotide Oxidases of Euglena gracilis var. bacillaris*

SYNOPSIS. Cell-free extracts of a streptomycin-bleached strain of Euglena gracilis var. bacillaris have been examined for enzyme systems primarily responsible for the oxidation of reduced pyridine nucelotides. NADH lipoyl dehydrogenase, NADH and NADPH oxidase, NADH and NADPH diaphorase, and NADH and NADPH cytochrome c reductase have been demonstrated. The NADPH-linked enzymes had lower activity rates and were less sensitive to N-ethyl maleimide and p-hydroxymercuribenzoate than their NADH-linked counterparts. NADH cytochrome c reductase was the most sensitive to antimycin A. Michaelis-Menten constants (K_m) determined were as follows: NADH diaphorase, 350 μM; NADPH diaphorase, 200 μM; NADH cytochrome c reductase, 13 μM; NADPH cytochrome c reductase, 9 μM; NADH oxidase, 100 μM; NADPH oxidase 150 μM; NADH lipoyl dehydrogenase, 0.35 μM. Enzyme activities after storage at –5 C indicate that the diaphorases are less labile than the other tested enzymes, and the differential activities of the NADH and NADPH linked enzymes suggest that functionally they may have different roles.     

Vitellogenesis in Austracris guttulosa (Walker) (Orthoptera: Acrididae) in Tropical Australia

In tropical northern Australia, vitellogenesis in Austracris guttulosa only occurs if two requirements are met: daylength exceeds 13 h and vegetation is green. During the dry season (April-September), daylength is short and vitellogenesis is inhibited regardless of vegetation condition. Daylength exeeds 13 h by mid October, and vitellogenesis begins by late October if there is green vegetation produced by recent rain. But it is often dry during October and vitellogenesis is delayed until it rains either in November or even December.     

Moving instead of asking? Performance-based tests and BASFI-questionnaire measure different aspects of physical function in ankylosing spondylitis

Introduction

Ankylosing Spondylitis (AS) is characterised by limitations in physical function. The Bath Ankylosing Spondylitis Functional Index (BASFI) is considered to be the gold-standard to assess physical function in AS patients. However, the BASFI questionnaire is a self-reported outcome measure and susceptible to subjective interpretation (under- or over-estimation). More objective outcome measures, like performance-based tests, could provide an objective outcome measurement for the evaluation of limitations in physical function. Therefore, the primary aim of this study was to determine the association between performance-based measures and the BASFI questionnaire.

Methods

In this cross-sectional study 126 AS patients completed the BASFI questionnaire and eight performance-based tests based on BASFI-items. Each test received three scores: one for performance (time or points) and a score for exertion and pain experienced during performance (using modified Borg-scale and VAS 0-100 mm, respectively). Linear regression analyses were used to assess the associations between the BASFI questionnaire and performance-based tests.

Results

The univariable association between performance and BASFI-score was moderate with a R-square of 0.31 and Beta of 0.56 (p's < 0.05). In a multivariable analysis, the association between performance, exertion and pain on the one hand and BASFI-score on the other was assessed; R-square increased to 0.54: the Beta's for exertion and pain during performance were 0.38 and 0.26, respectively; the Beta for performance decreased to 0.19 (p's < 0.05).

Conclusions

This study demonstrates that alongside actual performance, patients seem to incorporate exertion and pain in their assessment of perceived physical function on the BASFI questionnaire. Performance-based tests could provide an objective outcome measurement for the evaluation of physical function and give relevant new information in addition to the BASFI questionnaire.