Aspartate Aminotransferase Isoenzymes Research Articles

Influence of Polyamines on Red Beet (Beta vulgaris L. ssp. vulgaris) Gynogenesis

The influence of polyamines (PAs), putrescine (Put) and spermidine (Spd) on the efficiency of gynogenesis in ovule cultures of red beet (syn. beetroot) (Beta vulgaris L. vulgaris) cultivar “Czerwona Kula” and breeding accessions no. 3/2010 and no. 7/2008 was investigated. The effect of Put on the process of plant regeneration from gynogenetic embryos was studied. The response to the applied PAs was strongly dependent on the genotype. In “Czerwona Kula”, an increase in the number of obtained embryos was achieved by using each of the two PAs in the B5 medium. The effect of Spd was stronger. Put added to the regeneration medium at the concentration of 0.5 mg L−1 increased the number of obtained plants. All shoots placed on the rooting medium supplemented with 160 mg L−1 Put formed roots. The distribution of ploidy and homozygosity of gynogenetic plants depended on the genotype. Of the tested genotypes, the highest number of haploid plants, 68%, was obtained in red beet “Czerwona Kula”. The highest percentage of homozygotes, 69% for the glucose phosphate isomerase (GPI, E.C.5.3.1.9) isoenzyme and 100% for the aspartate aminotransferase (AAT, E.C.2.6.1.1) isoenzyme, was obtained in the population of gynogenetic plants of cultivar “Czerwona Kula”.

Effects of lymphocyte, C-reactive protein and prealbumin levels on clinical typing and course of disease in children infected with novel coronavirus.

Objectives:To investigate the effects of lymphocyte (LY), C-reactive protein (CRP) and prealbumin (PA) levels on the clinical typing and course of disease in children infected with novel coronavirus (2019-nCoV) at the early stage.Methods:A total of 140 children with 2019-nCoV infection diagnosed in Shijiazhuang People’s Hospital and Hebei Provincial Chest Hospital from January 2021 to February 2021 were selected for this study. According to the clinical symptoms, laboratory results and imaging examination, the children were divided into asymptomatic infection group, mild infection group and common infection group. The levels of white blood cell (WBC), LY, CRP, PA, albumin (ALB), aspartate aminotransferase (AST), alanine aminotransferase (ALT), creatine kinase (CK) and creatine kinase MB isoenzyme (CKMB) in the children were recorded on the 2nd d after the positive detection of 2019-nCoV nucleic acid.Results:There were 73(52.1%) children in the asymptomatic infection group, 35(25.0%) children in the mild infection group and 32(22.9%) children in the common infection group. LY level in the common infection group was lower than that in the asymptomatic infection group and the mild infection group (F= 3.152, both p< 0.05). CRP level in the common infection group was higher than that in the asymptomatic infection group and the mild infection group (F= 6.343, both p< 0.05). CRP level in the mild infection group was higher than that in the asymptomatic infection group (t= 2.052, p< 0.05). PA level in the common infection group and the mild infection group was lower compared with the asymptomatic infection group (F= 5.229, both p< 0.05). WBC, ALB, AST, ALT, CK and CKMB levels in the three groups showed no statistical significance (F= 1.803, F= 1.208, F= 2.391, F= 1.973, F= 0.401, F= 1.332, respectively, all p> 0.05). Correlation analysis demonstrated that LY and PA levels were negatively correlated with hospital stay (r= -0.265, r= -0.325, both p< 0.050), but CRP level was not correlated with hospital stay (r= -0.039, p> 0.05).Conclusion:CRP is correlated with the clinical typing of children with 2019-nCoV infection, while LY and PA levels may be closely correlated with the clinical typing and course of treatment of children with 2019-nCoV infection.

Isolated cell-bound membrane vesicles (CBMVs) as a novel class of drug nanocarriers

BackgroundCell-bound membrane vesicles (CBMVs) are a type of membrane vesicles different from the well-known extracellular vesicles (EVs). In recent years, the applications of EVs as drug delivery systems have been studied widely. A question may arise whether isolated CBMVs also have the possibility of being recruited as a drug delivery system or nanocarrier?MethodsTo test the possibility, CBMVs were isolated/purified from the surfaces of cultured endothelial cells, loaded with a putative antitumor drug doxorubicin (Dox), and characterized. Subsequently, cellular experiments and animal experiments using mouse models were performed to determine the in vitro and in vivo antitumor effects of Dox-loaded CBMVs (Dox-CBMVs or Dox@CBMVs), respectively.ResultsBoth Dox-free and Dox-loaded CBMVs were globular-shaped and nanometer-sized with an average diameter of ~ 300–400 nm. Dox-CBMVs could be internalized by cells and could kill multiple types of cancer cells. The in vivo antitumor ability of Dox-CBMVs also was confirmed. Moreover, Quantifications of blood cells (white blood cells and platelets) and specific enzymes (aspartate aminotransferase and creatine kinase isoenzymes) showed that Dox-CBMVs had lower side effects compared with free Dox.ConclusionsThe data show that the CBMV-entrapped Doxorubicin has the antitumor efficacy with lower side effects. This study provides evidence supporting the possibility of isolated cell-bound membrane vesicles as a novel drug nanocarrier.

Effects of ulinastatin combined with furosemide on myocardial enzymes, renal function and adverse reactions in patients with acute renal failure after cardiopulmonary resuscitation

Objective To explore the effects of ulinastatin combined with intravenous pump injection of furosemide on myocardial enzymes, renal function and adverse reactions in patients with acute renal failure(ARF) after cardiopulmonary resuscitation(CPR). Methods From January 2016 to May 2018, 117 patients with ARF after successful CPR in the Second People's Hospital of Hefei were divided into observation group(n=59) and control group(n=58) using simple random method.The control group received routine treatment, while the observation group added ulinastatin combined with intravenous pump infusion of furosemide.Myocardial enzymology, renal function, metabolism, inflammatory index, adverse reaction and survival rate were compared. Results Three and 7 days after treatment, the hydroxybutyrate dehydrogenase(HDBH), isoenzymes of creatine kinase isoenzyme(CK-MB) and mitochondrial aspartate aminotransferase isoenzyme(m-AST) were decreased in the two groups, and compared with the control group, which of the observation group were lower [HDBH: (231.42±31.15)U/L vs.(268.59±34.87)U/L; F=12.01, P=0.00; CK-MB: (32.38±4.15)ng/mL vs.(37.57±3.96)ng/mL; F=15.12, P=0.00; m-AST: (25.18±4.24)U/L vs.(33.92±5.60)U/L; F=12.36, P=0.00]. After treatment, the blood urea nitrogen(BUN), 24h urine protein quantity and creatinine(Cr) in the two groups increased firstly and then decreased, and compared with the control group, those of the observation group were lower[BUN: (7.02±1.66)mmol/L vs.(8.47±1.38)mmol/L; F=11.24, P=0.00; Cr: (82.69±9.87)μmol/L vs.(90.18±10.37)μmol/L; F=10.39, P=0.00; 24h urine protein quantity: (15.43±2.17)mg vs.(18.62±3.14)mg; F=11.06, P=0.00]. Three and 7 days after treatment, the levels of blood lactic acid(Lac), hypersensitive C-reactive protein(hs-CRP) and tumor necrosis factor-α(TNF-α) were decreased in the two groups, and compared with the control group, those of the observation group were lower [Lac: (1.18±0.27)mmol/L vs.(2.17±0.34)mmol/L, F=16.29, P=0.00; hs-CRP: (4.89±0.81)mg/L vs.(6.17±1.10)mg/L, F=13.41, P=0.00; TNF-α: (72.18±7.62)ng/L vs.(83.16±7.79)ng/L, F=11.39, P=0.00]. The incidence rates of adverse reactions in the observation group and the control group were 5.09% and 1.72%, respectively, the difference was statistically significant(χ2=0.24, P=0.62). The survival rates in the observation group and the control group were 50 cases (84.75%) and 39 cases (67.24%) respectively, the difference was statistically significant(χ2=4.92, P=0.02). Conclusion Intravenous pump injection of furosemide combined with ulinastatin can protect the heart and kidney, and improve the survival rate of patients with ARF after CPR and it is worthy of popularizing. Key words: Cardiopulmonary resuscitation; Renal insufficiency; Blood urea nitrogen; Creatinine; Blood lactic acid; Ulinastatin; Furosemide

Clinical analysis of continuous blood purification in the treatment of severe sepsis in infants

Objective To investigate the clinical efficacy and safety of continuous blood purification (CBP) in the treatment of severe sepsis in infants. Methods A retrospective analysis of 40 infants with severe sepsis treated with CBP was performed at PICU of Hunan Children′s Hospital from January 2014 to July 2017, and 50 infants with severe sepsis who were not treated with CBP at the same period were enrolled as control group.The indicators included blood gas analysis, lactic acid (Lac), blood glucose, electrolytes, blood routine, C-reaction protein (CRP) and procalcitonin (PCT), alanine aminotransferase (ALT) and aspartate aminotransferase (AST), total bilirubin(TB), urea nitrogen (BUN), serum creatinine (Scr) and creatine kinase isoenzyme MB (CK-MB), pediatric critical illness score (PCIS). Results (1) After 3 days of treatment, the recovery of body temperature, heart rate, respiratory rate and blood pressure in CBP group were better than those in the control group, and the differences between two groups were statistically significant(P 0.05). (5) Two cases of thrombocytopenia, 2 cases of femoral vein thrombosis, 2 cases of hypovolemic shock, and 1 case of blood coagulation in filter happened in CBP gruop, all cases had no puncture site infection. Conclusion CBP can improve the vital signs, internal environment, inflammatory reaction and organ function of infants with severe sepsis, and the effect is better than that of traditional methods.The complications of CBP in infants with severe sepsis are relatively large, so we should strictly master the indications of CBP in the treatment of severe sepsis in children. Key words: Continuous blood purification; Severe sepsis; Infants; Clinical efficacy; Safety

Induced androgenesis as a biotechnology method for obtaining DH plants in Daucus carota L.

ABSTRACTThe influence of various factors on the efficiency of obtaining double haploid lines in anther cultures was examined in Daucus carota L. The impact of the genotype, the formation of donor plants and the growth conditions was investigated. The effects of various regeneration media were analysed. Acclimatisation of androgenic plants and their evaluation were also conducted. Androgenesis was induced on B5 medium containing 2,4-D and NAA at 0.1 g·L−1. Depending on the genotype, 1.2–305.3 embryos per 100 anthers were obtained. The highest number of embryos (5.5 per 100 anthers) was obtained from donor plants with the first-order shoots containing one umbel. Cultivation of donor plants under controlled conditions improved the number of embryos from 305 in the open field to 1764 in the growth chamber. Regeneration of plants from androgenetic embryos proceeded most effectively on B5 medium without hormones and amino acids. Regenerated plants adapted in over 60%. Ploidy analysis showed the presence of 92% of plants with a doubled chromosome set and 8% with a tetraploid number of chromosomes. Plants with a doubled chromosome set were 73% homozygous for the glucose phosphate isomerase isoenzyme and 100% homozygous for the aspartate aminotransferase isoenzyme, which confirms their gametic origin.

Analysis of different toxic impacts of Fipronil on growth, hemato-biochemistry, protoplasm and reproduction in adult cockerels

Fipronil (FIP), a broad-spectrum phenylpyrazole, is extensively used across the globe to control pests and as a veterinary drug. Incorrect use of FIP leads to contamination of soil and water ultimately causes toxic effects in non-target organisms. Therefore, the present experimental study was aimed to determine the deleterious effects of sub-lethal concentrations of FIP in adult cockerels. FIP mixed in corn oil was administered orally in different groups as follows: A = control, B = 1.5 mg/kg, C = 2.5 mg/kg, D = 3.5 mg/kg and E = 4.5 mg/kg body weight for 60 d. Signs of toxicity like anemic comb, tremors, gasping and watery droppings were evident in birds exposed to higher levels. The feed intake, body weight, absolute and the relative weight of different organs were significantly (p ≤ .05) decreased in birds exposed to higher concentrations. Histomorphometric analysis of small intestine in birds exposed to higher levels of FIP showed decreased villus height and crypt depth of duodenum, jejunum and ilium. Histologically, congestion in liver, pyknosis of hepatocytes and congestion in kidneys along with necrosis of tubular epithelial cells and increased urinary spaces were observed in birds. Microscopically, seminiferous tubules exhibited necrotic nuclei of the spermatids, arrest of process of spermatogenesis and admixture of necrotic cells in testes of exposed birds. Moreover, significantly (p ≤ .05) decreased hematological parameters such as erythrocytes counts, hemoglobin concentrations and hematocrit, while increased total leukocyte counts were recorded in birds. Furthermore, significantly (p ≤ .05) increased concentrations of serum urea, creatinine, alanine aminotransferase, aspartate aminotransferase and cardiac isoenzyme (CK-MB), while reduced serum testosterone levels were recorded in birds. Results revealed significantly (p ≤ .05) increased frequency of micronuclei in erythrocyte and bone marrow cells. The findings of our study demonstrated that FIP induces deleterious impacts on multiple tissues in birds even at low doses.

Electrophoretic Studies of Isozymes of Glutamate Dehydrogenase (EC 1.4.1.3) (GDH) and Aspartate aminotransferase (EC: 2.6.1.1) AspAT (GOT) inSesuvium portulacastrum(L.), An Associate Halophyte.

Sesuvium portulacastrum L. (Aizoaceae) is a pioneer, psammophytic associate halophyte of subtropical, Mediterranean regions. It dominates coastal and warmer zones of the world. Apart from being utilized as a vegetable and forage by local people, it is also utilized for bioreclamation of saline soil in the arid and semiarid regions. Coastal soils has poor nitrogen content whereas halophytes which inhabit these areas have high protein content due to the ability to conserve nitrogen and recycle it through their body metabolism. In present investigation, Sesuvium portulacastrum (L.) is used as a model system representing an associate halophyte with efficacy in Nitrogen utilization in saline conditions. The plant has adapted to nitrogen stress by evolving efficient nitrogen assimilating isoenzymes. Isoenzymes of glutamate dehydrogenase (GDH) and Aspartate aminotransferase (AspAT) are separated electrophoretically from the leaves and roots of Sesuvium portulacastrum L. Presence of Isozymes for nitrogen assimilating and distributing enzymes like GDH and AspAT indicates the physiological adaptation of plants growing in saline nitrogen deficient conditions. The same study would be extended to other important enzymes of Nitrogen metabolism to get an insight in efficacy of such halophytes to conserve available Nitrogen from saline soils and help in phytoremediation of saline soils.

Aspartate aminotransferase isoenzymes in cucumber roots as depending upon the mineral composition of the medium

Aspartate aminotransferase (GOT) isoenzymes separated by means of electrophoresis on cellulose acetate gel were examined. Five GOT isoenzymes were discovered in cucumber roots after several days of their growth. The activity of these isoenzymes was dependent upon the mineral composition of the medium. If the medium did not contain nitrogen, isoenzymes 1, 3, and 4 showed only slight activity. Activity of all of the isoenzymes in the roots of seedlings assimilating NH&lt;sub&gt;4&lt;/sub&gt;&lt;sup&gt;+&lt;/sup&gt; ions was higher than in the roots of seedlings assimilating N0&lt;sub&gt;3&lt;/sub&gt;&lt;sup&gt;-&lt;/sup&gt; ions. Higher activity was observed in all of the isoemzymes in the nitrate or ammonium medium lacking calcium, while only some showed higher activity at the lack of potassium.

Liver Aspartate Transaminase Isoenzymes as Biomarkers of Chronic Exposure to Chromium(VI)

Exposure to hexavalent chromium compounds is associated with the risk of lung cancer, dermatitis, gastrointestinal ulcers, and other tissue damages. The aim of this study was to compare liver isoenzyme and total serum activities of aspartate aminotransferase (AST) as cytotoxic biomarkers of acute and chronic cytotoxicity of Cr(VI). We investigated the extent of cell damage caused by chromium(VI) in acute (2.5 mg kg(-1)) daily doses administered over five days and chronic (0.25 mg kg(-1) and 0.5 mg kg(-1)) daily doses administered over 15 to 60 days by measuring total AST in serum and low molecular weight AST (LMW-AST) and high molecular weight AST (HMW-AST) activities in thirty liver fractions. We also evaluated the kinetic properties and electrophoretic mobility of the LMW- and HMW-AST isoenzymes in liver subcellular fractions. Liver LMW-AST and total serum AST activities significantly decreased after 15 days of exposure (P<0.05). With continued treatment, AST activity increased by 15.67% (P<0.05). Interestingly, changes in serum AST activity were similar to changes in the liver LMW-AST isoenzyme. Our results confirmed that total serum AST activity may serve as a reliable tissue biomarker for long-term exposures to Cr(VI), but they also suggest that the LMW-AST isoenzyme could be even more sensitive.

Utility of cardiac biomarkers during adulticide treatment of heartworm disease (Dirofilaria immitis) in dogs

Heartworm disease (Dirofilaria immitis) is a parasitic disease of dogs and other carnivores, characterized by the presence of adult worms in the pulmonary arteries and right ventricle, leading to pulmonary hypertension which may progress to congestive heart failure. Cardiac biomarkers are biological parameters that can be objectively measured as indicators of pathological processes, or to assess the response to therapeutic interventions. To evaluate the myocardial damage during the adulticide treatment in 15 heartworm-infected dogs with ivermectin, doxycycline and melarsomine, measurements of cardiac troponin I (cTnI), myoglobin, MB isoenzyme of creatine kinase (CK-MB) and aspartate aminotransferase (AST) were carried out on days 0, 60 and afterwards weekly on days 67, 75, 82, 91, 106, 113 and 120. Dogs were divided by low parasite burden (n=9) and high parasite burden (n=6). On day 0, dogs with high worm burden showed increased cTnI concentrations (3.62±4.78ng/ml) while dogs with low worm burden had concentrations similar to those of healthy dogs (0.78±0.22ng/ml), CK-MB concentrations were increased only in dogs with high parasite burden as well (54.4±54.2U/l) and 26.6% (4/15) of the dogs showed pathological concentrations of myoglobin. On day 91, most dogs showed pathological concentrations of myoglobin, CK-MB and AST, probably due to the myositis associated to the intramuscular injection of melarsomine. The rest of the measurements made in the study, the biomarkers concentrations were within normal values, except for cTnI in dogs with high parasite burden, which remained above reference concentrations for healthy dogs during all the study. The evaluation of cardiac biomarkers seems to be a helpful test in the assessment of the myocardium in dogs with heartworm disease during the adulticide treatment.

Relationship between Tei index and the myocardial enzymes in newborns after asphyxia LEI Xiao-yan,

Objective To study the relationship between Tei index and the myocardial enzymes in newborns with myocardial damage due to asphyxia. Methods Forty-four newborns with mild asphyxia,27 newborns with severe asphyxia and 20 healthy newborns hospitalized in our hospital from January 2005 to December 2008 were enrolled in this study.The peak E and peak A and E/A ratio at mitral valve,the ejection fraction,isovolumetric contraction time,isovolumetric relaxation time and Tei index were measured by conventional echocardiography,and aspartate aminotransferase,creatine kinase,lactate dehydrogenase,hydroxybutyrate dehydrogenase and creatine phosphate kinase isoenzyme,and cardiac troponin T were tested also.One-way ANOVA was used to analyze the difference between groups. Results Tei index,isovolumetric contraction time and isovolumetric relaxation time in the severe asphyxia newborns were 0.62±0.13,(47±7)ms and(52±8)ms,higher than those in the mild asphyxia newborns[0.51±0.14,(41±6)ms and(43±6)ms],those in the mild asphyxia newborns were higher than in the healthy newborns[0.39±0.12,(34±6)ms and (37±6)ms] (all P<0.01).Aspartate aminotransferase,lactate dehydrogenase,hydroxybutyrate dehydrogenase,creatine kinase and its isoenzymes and cardiac troponin T in the severe asphyxia newborns were higher than in the mild asphyxia newborns and healthy group(P<0.01).Tei index,isovolumetric contraction time and isovolumetric relaxation time were positively related to the myocardial enzymes.The positive relationships were more statistically significant in Tel index,creatine kinase,its isoenzymes and cardiac troponin T(r=0.762,0.821,0.778,P<0.01).Conclusions Combination of Tei index and myocardial enzymes can not only be applied to assess the cardiac function in newborns with myocardial damage due to asphyxia,but also to evaluate the degree of cardiac dysfunction accurately and dynamically. Key words: Asphyxia neonatorum; Stroke volume; Creatine kinase; Lactate dehydrogenases

Isoenzyme variation in barley (Hordeum L.) 2. Aspartate aminotransferase and 6-phosphoglyconate dehydrogenase

Isoenzymes of aspartate aminotransferase (AAT) and 6-phosphoglyconate dehydrogenase (PGD) have been studied by polyacrylamide gel electrophoresis (PAGE) to elucidate phylogenetic relationships among Eurasian barley species. H. vulgare, H. spontaneum and H. bulbosum share the same electrophoretic phenotype of AAT different from those of the Murina group. This supports the inclusion of H. bulbosum in the type section, but argues against the inclusion of the Murina group. H. murinum s. str. (4x) and H. hrasdanicum (6x) of the Murina group have different heterozygous phenotypes of PGD, suggesting their alloploid nature. H. hrasdanicum reveals fixation of additional heterozygosity at two AAT loci. No accession of H. glaucum (2x) was found, fitting the donor of any of the genomes of H. murinum and H. hrasdanicum. The annuals of the series Marina differ distinctly from the Murina annuals of the section Trichostachys in some isoenzymes. They are removed from the section Trichostachys in a new section Marina (NEVSKI) JAASKA stat.nov. H. marinum ssp. gussoneanum tetraploids (= H. geniculalum auct.) show fixation of heterozygosity at two AAT loci, suggesting their alloploid nature. The outcrossing perennials H. bulbosum and H. brevisubulatum s. 1. show allozymic polymorphism of AAT-B and AAT-C, but are invariant in PGD-A. H. secalinum and H. jubatum share fixed heterozygosity of AAT-B, favouring their alloploid nature.

Isoenzyme variation in barley (Hordeum L.)

Isoenzymes of aspartate aminotransferase (AAT) and 6-phosphoglyconate dehydrogenase (PGD) have been studied by polyacrylamide gel electrophoresis (PAGE) to elucidate phylogenetic relationships among Eurasian barley species. H. vulgare, H. spontaneum and H. bulbosum share the same electrophoretic phenotype of AAT different from those of the Murina group. This supports the inclusion of H. bulbosum in the type section, but argues against the inclusion of the Murina group. H. murinum s. str. (4x) and H. hrasdanicum (6x) of the Murina group have different heterozygous phenotypes of PGD, suggesting their alloploid nature. H. hrasdanicum reveals fixation of additional heterozygosity at two AAT loci. No accession of H. glaucum (2x) was found, fitting the donor of any of the genomes of H. murinum and H. hrasdanicum. The annuals of the series Marina differ distinctly from the Murina annuals of the section Trichostachys in some isoenzymes. They are removed from the section Trichostachys in a new section Marina (Nevski) Jaaska stat.nov. H. marinum ssp. gussoneanum tetraploids (=H. geniculalum auct.) show fixation of heterozygosity at two AAT loci, suggesting their alloploid nature. The outcrossing perennials H. bulbosum and H. brevisubulatum s. 1. show allozymic polymorphism of AAT-B and AAT-C, but are invariant in PGD-A. H. secalinum and H. jubatum share fixed heterozygosity of AAT-B, favouring their alloploid nature.

Isoenzyme variation in the grass genus Elymus (Poaceae)

Variation of aspartate aminotransferase (AAT), aliphatic and aromatic alcohol dehydrogenases (ADH and AAD), esterase (EST), 6-phosphoglyconate dehydrogenase (PGD), and superoxide dismutase (SOD) isoenzymes encoded by 16 loci has been studied in about 60 Elymus species by means of polyacrylamide gel electrophoresis. Fixation of isoenzyme heterozygosity characteristic of alloploids is inherent to most Elymus species, evidenced by frequent occurrence of symmetric three-banded electrophoretic phenotypes of several dimeric enzymes. A fast-moving dimeric EST-A distinguishes two different types of alloploids with one common genome and the second, divergent, genome with distinctly different EST-A electromorphs. SOD-B, a cytosolic isoenzyme, revealed in most species fixed heterozygosity, combining four frequent and three rare electromorphs, whereas the chloroplastic SOD-A is mostly homozygous for a common one. Hexaploids frequently showed double heterozygosity of SOD-B with six-banded phenotypes. The two basic isoenzymes of AAT reveal homo- and heterozygous phenotypes with 5–7 homoeoallelic electromorphs. ADH showed up to six electromorphs, frequently in heterozygous phenotypes. The isoenzyme data are considered to support a view about a multiple polyphyletic origin of the genus Elymus through alloploidy followed by further-differentiation at the polyploid level.

Extremely Elevated Lactate Dehydrogenase and Aspartate Aminotransferase Level as an Indicator of Tumor Lysis during Bortezomib Treatment in a Multiple Myeloma Patient: Case Report.

Bortezomib has been shown to increase the response rate, time to disease progression, and overall survival in patients with relapsed-refractory multiple myeloma(MM). We currently treated a refractory MM patient and observed extremely elevated lactate dehydrogenase(LDH) and aspartate aminotransferase (AST) levels during bortezomib treatment, but without the abnormal serum electrolyte concentrations and elevated uric acid level. A 67 years old female was admitted to our hospital. She has been suffered with fatigue, lumbar myalgia, dizziness and difficulty in ambulation since Nov 2005. She was found renal inadequacy and intermediate anemia and was diagnosed with stage III MM, IgG type on bone marrow pathology, immunoglobulin analysis and X-ray examination. The disease was not controllable after 3 cycles of VAD regimen (vincristine, adriamycin and dexamethason). She had severe chest and back pain and was on morphine. Bone marrow morphology showed 32 percent plasma cells and her immunoglobulin G (IgG) level was 85g/L, microglobulin β2 level over 10000 ng/ml and creatinine 310.3mmol/L. She was also with hypercalcinemia and elevated serum LDH and AST transaminase level. Bortezomib therapy was considered with her refractory MM in disease progression and deterioration. Bortezomib at 1.3 mg/m2 IV days 1, 4, 8, 11 were planned to be administered in the first three weeks, in combination with dexamethazone at 40 mg on the same days. And a diphosphonate regimen was administered simultaneously. Hydration and alkalinization were initiated one day before the administering of chemotherapy. She was also given allopurinol prophylactically. She was suffered with severe debilitation and mild diarrhea after the second dosage of bortezomib. Gradually elevated LDH and AST were observed, with an extremely high point at 18666 and 9551 respectively on day 9 (table 1). LDH isoenzymes analysis showed that tumor-derived LDH3 and LDH4 were dramatically increased. AST isoenzyme analysis demonstrated elevated serum AST level, with normal level of mitochondria-derived AST level. Although her serum phosphate level was mild elevated and the calcium level was decreased, but the serum potassium, uric acid levels were normal. This could be the effect of diphosphonate regimen. The third and fourth doses of bortezomib were delayed for one week. Her chest and back pain was relieved shortly after the combination therapy. And only 1 percent of plasma cells were found on bone marrow smear prepared on day 20. Her IgG level decreased steadily and it was 19.5g/L on day 28. The microglobulin β2 level was 7200 ng/ml and creatinine was 173 mmol/L. She was still with elevated serum LDH and AST transaminase levels at 1129 and 324 respectively on day 28. We concluded that combination therapy with bortezomib and dexamethazone is very potent and effective in this refractory MM patient. The response is dramatically prompt with rapid tumor lysis demonstrated by extremely elevated LDH and AST level in this case. Carefully prophylactical measurement is recommended for patients under bortezomib treatment to prevent tumor lysis syndrome, a life-threatening metabolic emergency.Dynamic changes of LDH and AST level during bortezomib treatmentLDH(IU/L)AST(u/L)day 0915529day 21022539day 550323120day 7186669551day 8147066090day 973543575day 1056023704day 1148383324day 1328471220day 142529842

Regulation of glutamate‐synthesizing enzymes by NMDA and potassium in cerebellar granule cells

The presence of 25 mm potassium (KCl) or N-methyl-d-aspartate (NMDA) in cultured cerebellar granule neurons (CGN) induces a trophic effect, including a specific regulation of the enzymes involved in the glutamate neurotransmitter synthesis. In this study we explored the effect of these conditions on the cytosolic and mitochondrial isoenzymes of aspartate aminotransferase (AAT), and phosphate-activated glutaminase (PAG) in CGN. We found that NMDA and KCl increased the AAT total activity by 40% and 70%, respectively. This effect was mediated by an augmentation in the protein levels (68% by NMDA, 58% by KCl). NMDA raised the Vmax and KCl raised both the maximol velocity (Vmax) and Michaelis constant (Km) of AAT. NMDA increased cytosolic AAT activity by 30% and mitochondrial activity by 70%; KCl increased cytosolic and mitochondrial AAT activity by 60% and 100%, respectively. This activation was also related to an increase in the protein levels. The effect of both conditions on the activity and protein levels were more pronounced in mitochondrial than cytosolic AAT and the increment elicited by KCl was higher in both isoforms than that produced by NMDA. The PAG and AAT mRNA levels were also regulated by incubation with NMDA and KCl similarly to the observed changes in the protein levels. These results suggest that NMDA receptor stimulation during CGN development differentially regulates the two AAT isoenzymes involved in the maturation of CGN and that the regulation of both AAT and PAG occurs also at the mRNA expression level, suggesting the involvement of a mechanism of gene expression regulation.

Changes in ultrastructure and the occurrence of permeability transition in mitochondria during rat liver regeneration.

Mitochondrial bioenergetic impairment has been found in the organelles isolated from rat liver during the prereplicative phase of liver regeneration. To gain insight into the mechanism underlying this impairment, we investigated mitochondrial ultrastructure and membrane permeability properties in the course of liver regeneration after partial hepatectomy, with special interest to the role played by Ca2+ in this process. The results show that during the first day after partial hepatectomy, significant changes in the ultrastructure of mitochondria in situ occur. Mitochondrial swelling and release from mitochondria of both glutamate dehydrogenase and aspartate aminotransferase isoenzymes with an increase in the mitochondrial Ca2+ content were also observed. Cyclosporin-A proved to be able to prevent the changes in mitochondrial membrane permeability properties. At 24 h after partial hepatectomy, despite alteration in mitochondrial membrane permeability properties, no release of cytochrome c was found. The ultrastructure of mitochondria, the membrane permeability properties and the Ca2+ content returned to normal values during the replicative phase of liver regeneration. These results suggest that, during the prereplicative phase of liver regeneration, the changes in mitochondrial ultrastructure observed in liver specimens were correlated with Ca2+-induced permeability transition in mitochondria.

Characterization of aspartate aminotransferase isoenzymes from leaves of Lupinus albus L. cv Estoril.

Two aspartate aminotransferase (EC 2.6.1.1) isoenzymes (AAT-1 and AAT-2) from Lupinus albus L. cv Estoril were separated, purified, and characterized. The molecular weight, pI value, optimum pH, optimum temperature, and thermodynamic parameters for thermal inactivation of both isoenzymes were obtained. Studies of the kinetic mechanism, and the kinetics of product inhibition and high substrate concentration inhibition, were performed. The effect of some divalent ions and irreversible inhibitors on both AAT isoenzymes was also studied. Native PAGE showed a higher molecular weight for AAT-2 compared with AAT-1. AAT-1 appears to be more anionic than AAT- 2, which was suggested by the anion exchange chromatography. SDS-PAGE showed a similar sub-unit molecular weight for both isoenzymes. The optimum pH (between 8.0 and 9.0) and temperature (60-65 degrees C) were similar for both isoenzymes. In the temperature range of 45-65 degrees C, AAT-2 has higher thermostability than AAT-1. Both isoenzymes showed a high affinity for keto-acid substrates, as well as a higher affinity to aspartate than glutamate. Manganese ions induced an increase in both AAT isoenzymes activities, but no cooperative effect was detected. Among the inhibitors tested, hydroxylamine affected both isoenzymes activity by an irreversible inhibition mechanism.

Effects of substrate structural analogues on the enzymatic activities of aspartate aminotransferase isoenzymes.

Aspartate aminotransferase (AAT, EC 2.6.1.1) catalyses the transamination of L-asparate to oxaloacetate. It has been reported that AAT from different plant sources can catalyse the transamination of other compounds structurally similar to the natural substrates. Specificity and kinetic studies were performed with two aspartate aminotransferase isoenzymes (AAT-1 and AAT-2) from leaves of Lupinus albus L. cv Estoril using different amino donors and acceptors. Both isoenzymes showed residual activity for some of the substrates tested. Competitive inhibition was found with most of the structural analogues which is typical of a ping-pong bi-bi kinetic mechanism. It was found that both isoenzymes can use 2-amino-4-methoxy-4-oxobutanoic acid as amino donor. AAT-2 uses 2-amino-4-methoxy-4-oxobutanoic acid at a similar rate as L-aspartate but AAT-1 uses this substrate at a slower rate. The use of this amino donor by AAT isoenzymes has not been reported previously, and our results indicate structural differences between both isoenzymes.