Cytokine dysregulation in the post-Q-fever fatigue syndrome

High levels of protease inhibitors are induced in potato leaves by wounding. These inhibitors, when ingested by Colorado potato beetle (Leptinotarsa decemlineata Say) larvae, induce expression of specific proteolytic activities in the gut. Induced protease activities cannot be inhibited by potato inhibitors and thus enable the insects to overcome this defence mechanism of potato plants. The induced aminopeptidase and endoproteolytic activities both have the characteristics of cysteine proteases. Twenty-one protein inhibitors of different structural types have been examined for their ability to inhibit these activities in vitro. Members of the cystatin superfamily were found to be poor inhibitors of the induced endoproteolytic activities, except for the third domain of human kininogen, which was a fairly strong inhibitor (75% inhibition). The strongest inhibition (85%) of induced endoproteolytic activity was obtained using structurally different thyroglobulin type-1 domain-like inhibitors--equistatin and MHC class II-associated p41 invariant fragment. Experiments performed using three synthetic substrates for endoproteases gave similar results and indicate the existence of at least different endoproteolytic enzymes resistant to potato inhibitors. The induced aminopeptidase activity can be inhibited only by stefin family of inhibitors in cystatin superfamily. In in vivo experiments, Colorado potato beetle larvae fed on equistatin-coated potato leaves were strongly retarded in their growth and almost 50% died after 4 days. This demonstrated the potential of equistatin to protect crops from insect attack.     

Inhibitory properties of the regulatory domains of human protein kinase Calpha and mouse protein kinase Cepsilon

Two fusion proteins in which the regulatory domains of human protein kinase Calpha (Ralpha; amino acids 1-270) or mouse protein kinase Cepsilon (Repsilon; amino acids 1-385) were linked in frame with glutathione S-transferase (GST) were examined for their abilities to inhibit the catalytic activities of protein kinase Calpha (PKCalpha) and other protein kinases in vitro. Both GST-Ralpha and GST-Repsilon but not GST itself potently inhibited the activities of lipid-activated rat brain PKCalpha. In contrast, the fusion proteins had little or no inhibitory effect on the activities of the Ser/Thr protein kinases cAMP-dependent protein kinase, cGMP-dependent protein kinase, casein kinase II, myosin light chain kinase, and mitogen activated protein kinase or on the src Tyr kinase. GST-Ralpha and GST-Repsilon, on a molar basis, were 100-200-fold more potent inhibitors of PKCalpha activity than was the pseudosubstrate peptide PKC19-36. In addition, a GST-Ralpha fusion protein in which the first 32 amino acids of Ralpha were deleted (including the pseudosubstrate sequence from amino acids 19-31) was an effective competitive inhibitor of PKCalpha activity. The three GST-R fusion proteins also inhibited protamine-activated PKCalpha and proteolytically activated PKCalpha (PKM), two lipid-independent forms of PKCalpha; however, the IC50 values for inhibition were 1 order of magnitude greater than the IC50 values obtained in the presence of lipid. These results suggest that part of the inhibitory effect of the GST-R fusion proteins on lipid-activated PKCalpha may have resulted from sequestration of lipid activators. Nonetheless, as evidenced by their abilities to inhibit the lipid-independent forms of the enzyme, the GST-R fusion proteins also inhibited PKCalpha catalytic activity through direct interactions. These data indicate that the R domains of PKCalpha and PKCepsilon are specific inhibitors of protein kinase Calpha activity and suggest that regions of the R domain outside the pseudosubstrate sequence contribute to autoinhibition of the enzyme.     

Racial variation of factor VII activity and antigen levels and their correlates in healthy Chinese and Indians at low and high risk for coronary artery disease

We examined the genotypes of ALDH2, ADH2, ADH3 and P-4502E1 loci of alcoholics and nonalcoholics. Also we compared the frequencies of the homozygous ALDH2*1/1 genotype and heterozygous ALDH2*1/2 genotypes in alcoholics. Our study reported differences in the allelic frequencies of ALDH2, ADH2 and ADH3 loci between alcoholics and nonalcoholics. For alcoholics, it was indicated that ADH2 and ADH3 plays an important role for alcoholism. For genotypes of P-4502E1, no significant difference was observed between alcoholics and nonalcoholics. Alcoholics with the heterozygous ALDH2*1/2 genotype had significantly higher frequency of the ADH2*1 than that of alcoholics with ALDH2*1/1 genotype. Concerning the alcoholics with the heterozygous ALDH2*1/2 genotype, we assumed that ADH2*1 plays a role for the development of alcoholism.     

Morphological and molecular characterization of Giardia isolated from the straw-necked ibis (Threskiornis spinicollis) in Western Australia

Following the first report of avian Giardia infection in Australia, isolates of the parasite recovered from naturally infected straw-necked ibis (Theskiornis spinicollis) were characterized using median body morphology, scanning electron microscopy, multilocus enzyme electrophoresis, random amplified polymorphic DNA (RAPD), and small subunit ribosomal RNA (SSU-rRNA) analyses. Results were compared with Giardia from other birds and mammals, and the extent of genetic diversity between a range of ibis isolates collected in Western Australia was determined. The ibis isolates of Giardia were genetically relatively homogeneous, which is in contrast to the extensive genetic heterogeneity often displayed by mammalian Giardia isolates. Morphologically, Giardia from ibis were similar to Giardia ardeae although they differed genetically and by the fact that the ibis isolates could not be established in in vitro culture. Sequence data of the DNA coding for the SSU-rRNA found a 96% homology between the ibis isolates from Western Australia and G. ardeae, suggesting that they represent distinct strains of the same species. In contrast, the ibis isolates were genetically and morphologically very different than Giardia duodenalis and Giardia muris from mammals.     

Hypothermic modulation of cerebral ischemic injury during cardiopulmonary bypass in pigs

BACKGROUND: The aim of this study was to determine whether progressive levels of hypothermia (37, 34, 31, or 28 degrees C) during cardiopulmonary bypass (CPB) in pigs reduce the physiologic and metabolic consequences of global cerebral ischemia. METHODS: Sagittal sinus and cortical microdialysis catheters were inserted into anesthetized pigs. Animals were placed on CPB and randomly assigned to 37 degrees C (n = 10), 34 degrees C (n = 10), 31 degrees C (n = 11), or 28 degrees C (n = 10) management. Next 20 min of global cerebral ischemia was produced by temporarily ligating the innominate and left subclavian arteries, followed by reperfusion, rewarming, and termination of CPB. Cerebral oxygen metabolism (CMRO2) was calculated by cerebral blood flow (radioactive microspheres) and arteriovenous oxygen content gradient. Cortical excitatory amino acids (EAA) by microdialysis were measured using high-performance liquid chromatography. Electroencephalographic (EEG) signals were graded by observers blinded to the protocol. After CPB, cerebrospinal fluid was sampled to test for S-100 protein and the cerebral cortex was biopsied. RESULTS: Cerebral oxygen metabolism increased after rewarming from 28 degrees C, 31 degrees C, and 34 degrees C CPB but not in the 37 degrees animals; CMRO2 remained lower with 37 degrees C (1.8 +/- 0.2 ml x min[-1] x 100 g[-1]) than with 28 degrees C (3.1 +/- 0.1 ml x min[-1] x 100 g[-1]; P < 0.05). The EEG scores after CPB were depressed in all groups and remained significantly lower in the 37 degrees C animals. With 28 degrees C and 31 degrees C CPB, EAA concentrations did not change. In contrast, glutamate increased by sixfold during ischemia at 37 degrees C and remained significantly greater during reperfusion in the 34 degrees C and 37 degrees C groups. Cortical biopsy specimens showed no intergroup differences in energy metabolites except two to three times greater brain lactate in the 37 degrees C animals. S-100 protein in cerebrospinal fluid was greater in the 37 degrees C (6 +/- 0.9 microg/l) and 34 degrees C (3.5 +/- 0.5 microg/l) groups than the 31 degrees C (1.9 +/- 0.1 microg/l) and 28 degrees C (1.7 +/- 0.2 microg/l) animals. CONCLUSIONS: Hypothermia to 28 degrees C and 31 degrees C provides significant cerebral recovery from 20 min of global ischemia during CPB in terms of EAA release, EEG and cerebral metabolic recovery, and S-100 protein release without greater advantage from cooling to 28 degrees C compared with 31 degrees C. In contrast, ischemia during 34 degrees C and particularly 37 degrees C CPB showed greater EAA release and evidence of neurologic morbidity. Cooling to 31 degrees C was necessary to improve acute recovery during global cerebral ischemia on CPB.     

Functional dissection of systemic lupus erythematosus using congenic mouse strains

We describe the in vivo phenotypes associated with three genomic intervals containing systemic lupus erythematosus (SLE)-susceptibility genes derived from the SLE-prone NZM2410 strain on a C57BL/6 genome. These intervals were identified previously via a genome-wide analysis of SLE susceptibility in a (NZM2410 x C57BL/6)F1 x NZM2410 backcross, and transferred independently on a C57BL/6 background to produce three congenic strains: B6.NZMc1 carrying Sle1, B6.NZMc4 carrying Sle2, and B6.NZMc7 carrying Sle3. B6.NZMc1 develops high titers of IgG anti-nuclear autoantibodies in the absence of any severe nephritis. B6.NZMc4 spontaneously develops elevated levels of IgM, but not IgG Abs against several Ags, indicative of polyclonal activation or polyreactivity affecting the B cell lineage. B6.NZMc7 causes the production of IgM and IgG Abs against both nuclear and non-nuclear Ags and the development of severe lupus nephritis. Therefore, our results show that three defined genomic intervals from the NZM2410 SLE-prone strain each contribute specific component phenotypes that have been associated with SLE, which in combination can mediate severe disease.