Laboratory diagnosis of canine GM2-gangliosidosis using blood and cerebrospinal fluid.

In the present study, laboratory techniques were used to diagnose canine GM2-gangliosidosis using blood and cerebrospinal fluid (CSF) that can be collected noninvasively from living individuals. Lysosomal acid beta-hexosaminidase (Hex) was measured spectrofluorometrically using 4-methylumbelliferyl N-acetyl-beta-D-glucosaminide and 4-methylumbelliferyl 7-(6-sulfo-2-acetamido-2-deoxy-beta-D-glucopyranoside) as substrates. Main isoenzymes A and B of Hex in leukocytes were also analyzed using cellulose acetate membrane electrophoresis. GM2-ganglioside in CSF was detected and determined quantitatively by using thin-layer chromatography/enzyme-immunostaining method with anti-GM2-ganglioside antibody. In normal dogs, Hex activities could be determined in leukocytes, serum, and CSF and the total activities were markedly reduced in all the enzyme sources in a dog with Sandhoff disease. Electrophoresis of a leukocyte lysate from a normal dog showed that the Hex A and Hex B were not separated distinctively with formation of a broad band, whereas there were no bands in electrophoresis of a lysate from a dog with Sandhoff disease, showing a deficiency in the total enzyme activity. GM2-ganglioside could be detected and determined quantitatively in as little as 100 microl of canine CSE GM2-ganglioside in CSF in a dog with Sandhoff disease increased to 46 times the normal level. In conclusion, the methods in the present study are useful for diagnosis of canine GM2-gangliosidosis. These techniques enable definitive and early diagnosis of canine GM2-gangliosidosis even if tissues and organs cannot be obtained.     

Oral administration of L-citrulline changes the concentrations of plasma hormones and biochemical profile in heat-exposed broilers

We examined the effects of oral administration of L-citrulline (L-Cit) on plasma metabolic hormones and biochemical profile in broilers. Food intake, water intake, and body temperature were also analyzed. After dual oral administration (20 mmol/head/administration) of L-Cit, broilers were exposed to a high ambient temperature (HT; 30 ± 1°C) chamber for 120 min. Oral administration of L-Cit reduced (p < .001) rectal temperature in broilers. Food intake was increased (p < .05) by heat stress, but it was reduced (p < .05) by L-Cit. Plasma levels of 3,5,3′-triiodothyronine, which initially increased (p < .0001) due to heat stress, were reduced (p < .01) by oral administration of L-Cit. Plasma insulin levels were increased by heat exposure (p < .01) and oral L-Cit (p < .05). Heat stress caused a decline (p < .05) in plasma thyroxine. Plasma lactic acid (p < .05) and non-esterified fatty acids (p < .01) were increased in L-Cit-treated heat-exposed broilers. In conclusion, our results suggest that oral L-Cit can modulate plasma concentrations of major metabolic hormones and reduces food intake in broilers.     

Single nucleotide polymorphism in avian uncoupling protein gene is associated with thermoregulation in chicks

Avian uncoupling protein (av-UCP) is a key protein for thermoregulation in poultry. A single nucleotide polymorphism (SNP) in the av-UCP gene has been reported in chickens. The purpose of the current study was to clarify the association between this av-UCP gene mutation and thermoregulation in chickens. Wild and mutant type chicks for the av-UCP gene SNP (g. 1270 of the av-UCP gene exon 3 with C to T substitution and amino acid substitution) were exposed to high ambient temperature. Rectal temperature, radiation temperature on the body surface, and the expression of heat dissipation behavior (wing drooping and panting) during heat exposure were measured. In addition, oxygen consumption rate in the thermoneutral zone in wild and mutant type chicks was measured. Changes in wing temperature during heat exposure in wild-type chicks were lower than those in mutants. The latency of continuous wing drooping during heat exposure in wild-type chicks was shorter than in mutant chicks. It was also found that the SNP in the av-UCP gene caused reduced oxygen consumption. These results suggest that the av-UCP gene mutation affects thermoregulation, especially heat production, in chickens.     

Therapeutic effect of anti-TNF-alpha antibody and levofloxacin (LVFX) in a mouse model of enterohemorrhagic Escherichia coli O157 infection

The ability of an anti-TNF-alpha antibody to confer protection against enterohaemorrhagic Escherichia coli (EHEC) O157 was investigated in germfree IQI mice. The use of an antibiotic levofloxacin (LVFX) alone or with the antibody was also studied. Protection included an increase in survival rate. Treatment with the anti-TNF-alpha antibody inhibited the histological signs associated with EHEC infection but did not prevent the colonization of EHEC or production of Shiga toxin (Stx). No clinical signs were observed and EHEC was completely eliminated in the mouse model receiving both anti-TNF-alpha antibody and LVFX. Anti-TNF-alpha antibody suppressed inflammatory cytokine response in the mouse kidney and brain by EHEC infection.     

Silicon content in rice seedlings to protect rice blast fungus at the nursery stage

To control rice blast effectively at the nursery stage, the absolute SiO₂ content necessary for rice plants to resist blast disease was investigated using various rice cultivars and soils. Nine rice cultivars with different complete resistance genes and different degrees of partial resistance were grown on nursery soils amended with silica gel at different rates to change the SiO₂ content of rice plant. The rice seedlings were then inoculated 28 days after sowing with Pyricularia grisea to estimate their blast resistance. In all rice cultivars, the number of lesions was significantly reduced when SiO₂ content increased in the rice seedling; lesions were reduced to 5%–20% of the number on the seedlings grown in soil without silica gel when the seedling SiO₂ content reached 5%. Additionally, the susceptibility to blast disease of rice seedlings grown on eight soils collected from different districts, with varying amounts of silica gel, was compared. The number of lesions decreased significantly when the SiO₂ content in the seedlings reached 5%. These results suggest that SiO₂ content of at least 5% in the rice plant can control this disease at the nursery stage under any conditions.     

Spectral analysis of heart rate variability in dogs with mild mitral regurgitation

OBJECTIVE: To assess autonomic function in dogs with mild mitral regurgitation (MR) that did not have clinical signs of the condition. ANIMALS: 6 healthy adult Beagles. PROCEDURE: Mild MR was experimentally induced. A 24-hour ambulatory ECG was recorded before and after induction of MR. Heart rate variability was analyzed in frequency domains by use of the ambulatory ECG. Low-frequency (LF) and high-frequency (HF) power were calculated by integrating over their frequency intervals, and the ratio of LF to HF was also calculated. Measurements of frequency domains were analyzed for 4 time periods (midnight to 6 AM, 6 AM to noon, noon to 6 PM, and 6 PM to midnight). RESULTS: Dogs with experimentally induced MR were classified as International Small Animal Cardiac Health Council class Ia. The HF power of dogs with MR was significantly decreased between 6 AM and noon. The ratio of LF to HF in dogs with MR was significantly increased for the periods between midnight and 6 AM, 6 AM and noon, and noon and 6 PM. CONCLUSIONS AND CLINICAL RELEVANCE: Compensatory response through autonomic modulation was observed in dogs with mild MR that did not have abnormalities, except for cardiac murmur, during clinical examination. This result suggests that treatment during the early stages of mild MR may be beneficial. Additional studies are necessary to determine whether such treatment will delay the onset of congestive heart failure and prolong survival in dogs affected with mild MR.     

家蚕肾形卵的荧光差异显示分析

Liang等建立的mRNA的荧光差异显示法 (flourescentdifferentialdisplay,FDD)具有高效、安全、有用信息多等特点。利用这一方法在mRNA水平上探讨了肾形卵 (ki)与正常卵在初期胚胎阶段的基因表达 ,回收了差异片段 10条 ,并对其差异进行了验证。其中之一的片段序列分析表明为低分子量热激蛋白基因 (smallheatshockgene)。