OBJECTIVETo explore the pathophysiological and biomechanical features of skeletal muscular injury for providing a rational basis for its treatment, prevention and rehabilitation.

METHODSIn 70 adult rabbits, the left tibialis anterior (TA) muscle was stretched to injury, while the right TA muscle served as control. Histological, enzymohistochemical and biomechanical changes were observed on days 0, 1, 2, 3, and 7 after injury. Cytochrome oxidase (CCO), acid phosphatase (ACP), ATPase, succinate dehydrogenase (SDH), malate dehydrogenase (MDH), NADH-diaphorase (NADHD), glutamatedehydrogenase (GDH), alpha-glycerophosphate dehydrogenase (alpha-GPD) and lactate dehydrogenase (LDH) were measured. The examined biomechanical parameters included maximal contractile force, ultimate load, length, energy absorption, tangent stiffness, and rupture site.

RESULTSPartial or complete rupture of TA muscle occurred near the muscle-tendon junction. There was an intense inflammatory reaction on day 1 and 2 after injury. Endomysium fibrosis and myotube formation were observed on day 3, and developed further on day 7. The activity of cell oxidases (CCO, ATPase, MDH, alpha-GPD, SDH, NADHD and GDH) showed a significant drop from day 0 to 2, and resumed with different levels on day 3. The increment of enzymatic activities continued on day 7 and the levels of NADHD and alpha-GPD reached to the levels of control muscle. Maximal contractile force was 70.17%+/-3.82% of controls immediately after injury, 54.82%+/-3.09% at 1 day, 66.41%+/-4.36% at 2 days, 78.39%+/-4.90% at 3 days and 93.64%+/-5.02% at 7 days. Ultimate load was 85.78%+/-7.54% of controls at the moment of injury, 61.44%+/-5.91% at 1 day, 49.17%+/-4.26% at 2 days, 64.43%+/-5.02% at 3 days, and 76.71%+/-6.46% at 7 days.

CONCLUSIONSEndomysium fibrosis and scar formation at the injured site are responsible for frequent recurrence of skeletal muscle injury. Recovery of tensile load slower than that of maximal contractile force may be another cause. Whether the injured muscle returns to normal exercise is mainly determined by the tensility on which the muscle-tendon can bear rather than the maximal contractile force.

Acid Phosphatase ; analysis ; Adenosine Triphosphatases ; analysis ; Animals ; Biomechanical Phenomena ; Dihydrolipoamide Dehydrogenase ; analysis ; Electron Transport Complex IV ; analysis ; Glutamate Dehydrogenase ; analysis ; Glycerolphosphate Dehydrogenase ; analysis ; L-Lactate Dehydrogenase ; analysis ; Malate Dehydrogenase ; analysis ; Muscle, Skeletal ; injuries ; pathology ; physiology ; Rabbits ; Succinate Dehydrogenase ; analysis

OBJECTIVETo study the mechanism of vestibular compensation and to observe the changes of c-Fos and NADPH-d expressions in the brainstem of the vestibular deafferentation rats in static status or following angular acceleration stimulation.

METHODSTotally 60 SD rats were randomly divided into control group (labyrinthine intact), complete unilateral vestibular deafferentation (UVD) group, simultaneous complete bilateral vestibular deafferentation (BVD) group (n = 20 in each group). Subgroups (n = 10 in each subgroup) were set for static status or following angular acceleration stimulation in each group. Double labeling with histochemistry-immunohistochemistry was performed to observe c-Fos/NADPH-d neurons.

RESULTSNo positive c-Fos/NADPH-d expression was observed in the both sides of medial vestibular nucleus (MVN) and prepositus hypoglossi (PrH) of normal rats in static status and BVD rats whether following canal rotation or not. c-Fos/ NADPH-d expression was observed in the ipsilesional MVN and the contralesional PrH of UVD rats. However, c-Fos/NADPH-d were detected in both sides of MVN and PrH in UVD rats and normal rats following angular acceleration stimulation.

CONCLUSIONIn the ipsilesional MVN and the contralesional PrH, c-Fos plays an important role in vestibular compensation, in which nitric oxide acts as a key neurotransmitter.

Animals ; Brain Stem ; metabolism ; Dihydrolipoamide Dehydrogenase ; genetics ; metabolism ; Female ; Gene Expression ; Male ; Proto-Oncogene Proteins c-fos ; genetics ; metabolism ; Random Allocation ; Rats ; Rats, Sprague-Dawley ; Vestibule, Labyrinth ; physiology

We studied the ability of lpdA gene knockout Escherichia coli to ferment different sugars in mineral salts medium for the production of pyruvate. The sugars studied were glucose, fructose, xylose and mannose at a concentration of 10 g/L. At the same time, effect of inoculum size on lpdA fermentation with glucose was studied. The strain was able to use all sugars for biomass generation and pyruvate production. The lpdA knockout mutant converted glucose, fructose, xylose and mannose to pyruvate with yields of 0.884 g/g, 0.802 g/g, 0.817 g/g and 0.808 g/L, respectively. The pyruvate accumulation curve coupled with cell growth except for mannose as carbon source. When the inoculation size increased, the rate of glucose consumption, pyruvate accumulation and cell growth increased but lower pyruvate concentration. This study demonstrates that E. coli lpdA mutant has the potential to produce pyruvic acid from xylose and mannose.
Carbon ; metabolism ; Dihydrolipoamide Dehydrogenase ; genetics ; Escherichia coli ; genetics ; metabolism ; Escherichia coli Proteins ; genetics ; Fermentation ; Fructose ; metabolism ; Gene Knockout Techniques ; Glucose ; metabolism ; Mannose ; metabolism ; Pyruvic Acid ; metabolism ; Xylose ; metabolism

OBJECTIVE: To analyze the clinical and genetic characteristics of a patient with dihydrolipoamide dehydrogenase deficiency. METHODS: Potential variants of the DLD gene were detected by whole exome sequencing and verified by Sanger sequencing. RESULTS: Compound heterozygous variants, c.704_705delTT (p.Leu235Argfs*8) and c.1058T>C (p.Ile353Thr), were detected in the DLD gene. The c.1058T>C (p.Ile353Thr) variant was derived from his mother and known to be pathogenic. The c.704_705delTT (p.Leu235Argfs*8) variant was derived from his father and was unreported previously. CONCLUSION The compound heterozygous variants of c.704_705delTT (p.Leu235Argfs*8) and c.1058T>C (p.Ile353Thr) of the DLD gene probably underlay the disease in this patient. Above finding has facilitated genetic counseling and prenatal diagnosis for the family.
Acidosis, Lactic/genetics* ; Dihydrolipoamide Dehydrogenase/genetics* ; Female ; Genetic Testing ; Genetic Variation ; Humans ; Male ; Maple Syrup Urine Disease/genetics* ; Pregnancy ; Whole Exome Sequencing

OBJECTIVETo compare the application of HE and enzyme histochemical staining in assessing the viability of hepatocellular carcinoma (HCC) cells coagulated by microwave ablation at different temperatures.

METHODSTwo groups of mice (n=6) with transplanted homogenic HCC were treated by microwave ablation at 60 degrees C and 50 degrees C for 3 min, respectively. Before and after microwave ablation, paraffin sections and frozen sections of the tumors were prepared for routine HE staining and enzyme histochemical staining with nicotinamide adenine dinucleotide diaphorase (NADH-diaphorase), respectively, and observed under microscope.

RESULTSShortly after microwave ablation, the morphology and arrangements of the nucleus of the ablated tumor cells in the two groups showed no obvious alteration in HE stained sections, but in sections with enzyme histochemical staining, the activity of NADH-diaphorase in ablated tumor tissue at 60 degrees C disappeared, suggesting the death of HCC cells; sporadic activity of the enzyme was detected in the coagulated tumor at 50 degrees C, indicating tumor cells surviving the ablation. The ablation effect was markedly different between the two groups (P<0.01).

CONCLUSIONHE staining is not suitable for evaluation of HCC destruction immediately after microwave ablation, and detection of NADH-diaphorase activity with the enzyme histochemical method better suits this purpose.

Animals ; Catheter Ablation ; methods ; Dihydrolipoamide Dehydrogenase ; metabolism ; Female ; Histocytochemistry ; methods ; Liver Neoplasms ; enzymology ; pathology ; therapy ; Liver Neoplasms, Experimental ; enzymology ; pathology ; therapy ; Mice ; Mice, Inbred C57BL ; Microwaves ; therapeutic use ; Temperature

Methemoglobinemia is an uncommon clinical problem generally caused by inherited disorders of hemoglobin metabolism or environmental toxicity from oxidizing agents. Since methemoglobin has no oxigen carrying capacity, patient with severe methemoglobinemia may have dangerous hypoxia even when arterial oxygen tension is normal. Degree of exposure to oxidants which are benign for older individuals may produce severe methemoglobinemia I Fetal hemoglobin has increased susceptibility to oxidatin. NADH diaphorase activity is reduced to 60% of adult levels in newborn erythrocytes. Low pH further reduces the activity of the enzyme. We report our experience with 5 unrelated nweborns, ranging in age from 9 to 33 days, who presented with diarrhea, dehydration, acidosis and transient methemoglobinemia. No history of toxin exposure could be elicited. On admission, all patients weighted less than their birth weights. All were mild to severely dehydrated, acidotic and methemoglobin levels ranged from 14.7% to 49.1%. In one cases Pseudomonas aeruginosa was isolated in the stool. Rehydration and correction of acidosis were done. Three of them were trated with 2mg/kg of methylene blue and improved immediately. Two patient improved without methylene blue injection. Methemoglobinemia under acidosis may be a common phenomenon in newborn period.
Acidosis* ; Adult ; Anoxia ; Birth Weight ; Natural Resources ; Dehydration ; Diarrhea ; Dihydrolipoamide Dehydrogenase ; Erythrocytes ; Fetal Hemoglobin ; Fluid Therapy ; Humans ; Hydrogen-Ion Concentration ; Infant, Newborn* ; Metabolism ; Methemoglobin ; Methemoglobinemia* ; Methylene Blue ; Oxidants ; Oxygen ; Pseudomonas aeruginosa