Effects of mixed agro-residues (corn crop waste) on lignin-degrading enzyme activities,growth, and quality of Lentinula edodes

Using agro-residues in bioreactors to produce mushrooms is an important component of eco-agriculture. Here, we tested the cultivation of Lentinula edodes with corn cob (CC) and corn straw (CS), and then evaluated the resulting enzyme activities, agronomic traits, textures and nutrient compositions of mushrooms. Laccase (T1 formula, 3.26 g U⁻¹) and carboxymethyl cellulase (T3 formula, 1.01 g U⁻¹) activities were the highest at the time for a complete substrate colonization stage (TCSC), while acidic xylanase activity was the highest (CK formula, 4.05 g U⁻¹) in the mushroom block to color-turned (TMBCT) stage. The biological efficiency of growth on the T6 formula was 8.82% higher than growth on the CK formula, wherein the low C/N ratio of the substrate had an obvious negative effect on yield while the mass ratio of pileus (MRP) of fruiting bodies did not change with mixed substrates. No significant differences were observed in mineral composition for CK formulas, but corn crop waste (CCW) formulas exhibited more optimal nutritional contents. A formula containing more corn cob and sawdust (SD) (sum of at least 70%) as the substrate can produce fruiting bodies with good hardness. These results indicate that the use of corn cobs as the main ingredient, mixed with sawdust and corn straw to grow L. edodes provides a more efficient use of agro-residues for growth. Thus, mixed agro-residue formulas have exceptional advantages in texture, nutrition of fruiting bodies, and yields.

Using agro-residues in bioreactors to produce mushrooms is an important component of eco-agriculture.     

The yield and quality of Pleurotus abieticola grown on nematode-infected Pinus massoniana chips

In this study, we investigated the use of nematode-infected Pinus massoniana chips (NPC) as the main ingredient in Pleurotus abieticola substrate. The effects of different substrate formulas on nutritional parameters, including total sugars, polysaccharides, proteins, lipids, amino acids, and fatty acids were assessed. The results indicated that NPC was suitable for P. abieticola cultivation. However, the addition of certain amounts of corncobs (CC) and cottonseed hulks (CH) improved the yield. Substrate T5 (45% NPC, 6% CC, and 27% CH) had the greatest yield (121.38 g per bag), 34.56% greater than the yield of the control (78% poplar chips), which was 79.43 g per bag. Across the 11 substrate formulas tested, the total sugar, polysaccharide, crude protein, and crude lipid contents were 16.60–28.90%, 2.71–3.73%, 36.49–45.42%, and 1.03–4.34%, respectively. On all substrates, the fruiting bodies contained 17 amino acids, primarily glutamine (2.42–4.11%), followed by proline (2.56–3.73%), leucine (2.09–3.19%), phenylalanine (1.56–2.61%), and glycine (1.76–2.55%). The fruiting bodies contained 12 fatty acids, of which linoleic acid was the most abundant (82.36%–84.03%), followed by palmitic acid (6.42%–6.89%) and oleic acid (5.50%–7.34%). The fatty acid content was closely associated with the NPC content, which might indicate that NPC promoted fatty acid accumulation. Thus, NPC represents a new substrate suitable for P. abieticola cultivation.

In this study, we investigated the use of nematode-infected Pinus massoniana chips (NPC) as the main ingredient in Pleurotus abieticola substrate.     

Formation mechanism and characterization of porous biomass carbon for excellent performance lithium-ion batteries

Porous biomass carbon derived from corn stalks was prepared via carbonization and activation of CaCl₂. Combined with its microstructure, the formation mechanism and electrochemical properties were analyzed. The addition of CaCl₂ was the key factor to form the porous structure, and the proportion of CaCl₂ had a significant impact on the pores distribution and electrochemical properties. The resulting sample had a specific surface area of 370.6 m² g⁻¹ and an average pore size of 9.65 nm. The sample was circulated at 0.2C for 100 cycles, the specific discharge capacity was 783 mA h g⁻¹. After 60 cycles at different rates, when the current was restored to 0.2C again, the discharge specific capacity quickly recovered. This showed that the sample had excellent rate performance and cycle stability for lithium-ion batteries.

Porous biomass carbon derived from corn stalks was prepared via carbonization and activation of CaCl₂.     

肾脏深度对SPECT测定肾小球滤过率的影响

目的 评估6种肾脏深度估算公式对^99mTc-DTPA肾动态显像测定肾小球滤过率(GFR)的影响。 方法 以232名北京地区健康居民为研究对象,分别采用双血浆法和^99mTc-DTPA肾动态显像法测定GFR(GFR_dt和GFR_Gates)。分析6种肾脏深度估算公式所得GFR_Gates与GFR_dt间的相关性及一致性。 结果 公式1和5所得肾脏深度显著低于其他公式,公式3和6所得GFR_Gates与GFR_dt的相关性最好(r=0.81)。公式1和5所得GFR_Gates与GFR_dt一致性最差,差值均值分别为(-23.62±18.60)ml/(min·1.73 m²)、(-20.66±18.00)ml/(min·1.73 m²);公式3和4所得GFR_Gates与GFR_dt一致性最好,差值均值分别为(-5.80±16.76)ml/(min·1.73 m²)和(-3.81±17.87)ml/(min·1.73 m²)。 结论 肾脏深度估算公式1、2、5准确性较差,其他公式结果差异较小;公式3、4和6均可用于临床,但公式3和4更优。     

Identification and sensitivity of two rare fungal species isolated from two patients with Fusarium keratomycosis

We report two cases of Fusarium keratomycosis in which molecular analysis was used to identify two rare causative Fusarium species. A 65-year-old woman was diagnosed with Fusarium keratomycosis caused by F. equiseti, confirmed by sequencing the internal transcribed spacer (ITS) region and morphological characteristics. She was initially treated with topical corticosteroid but the keratitis did not improve. Even after aggressive antifungal treatment, there was a severe reduction of vision. In the end, the eye perforated. Our second case was a 75-year-old man who had diabetes mellitus. He developed keratitis after his cornea was injured by corn stalks. The ITS region identified the causative organism as F. verticillioides. Unlike the first case, he had good visual recovery after early antifungal therapy. Our findings demonstrate that both ITS and morphological characteristics can be used to identify the exact Fusarium species causing Fusarium keratomycosis. This allowed us to determine the sensitivity of these species to antifungal drugs that can be used to treat patients with these species of Fusarium.     

Co-cultured Lepista sordida and Pholiota nameko polysaccharide-iron(iii) chelates exhibit good antioxidant activity

In the present study, the structural characteristics and antioxidant activities of polysaccharide from the co-cultured Lepista sordida and Pholiota nameko and its polysaccharide-iron(iii) chelates were determined. Two polysaccharide fractions named CP-1 and CP-3 were isolated previously from polysaccharide of the fermentation liquid of the co-cultured Lepista sordida and Pholiota nameko. And their chemical structures were measured by FT-IR infrared spectroscopy, TG analysis, X-ray diffraction and ¹H NMR spectroscopy. The results suggested that polysaccharides were chelated with iron(iii) by –OH and –COOH groups, forming a stable structure of β-FeOOH and improving crystallinity. Furthermore, the antioxidant activities of polysaccharide-iron(iii) chelates exhibited stronger hydroxyl radical and superoxide radical scavenging activity than the polysaccharides. Therefore, the polysaccharide-iron(iii) chelates could be used as a potential iron supplement.

In the present study, the structural characteristics and antioxidant activities of polysaccharide from the co-cultured Lepista sordida and Pholiota nameko and its polysaccharide-iron(iii) chelates were determined.     

Effect of the level and type of dietary fat on the metabolism of cholesterol and beta lipoproteins in the Cebus monkey

A study was carried out to determine the effect of the level and type of dietary fat on the concentration of cholesterol and beta lipoproteins in the sera of Cebus monkeys. Three groups of monkeys were fed isocaloric diets containing a fixed ratio of alpha protein and cholesterol to calories but with different amounts of corn oil and sucrose. Corn oil provided 10, 32, and 45 per cent of the calories in the three diets, and the level of sucrose was varied inversely. After 8 weeks the serum cholesterol and S_f 12 to 100 beta lipoprotein concentrations were significantly greater in the medium and high fat groups. When corn oil was decreased from 45 to 10 per cent of dietary calories and sucrose was increased, the serum cholesterol fell in all cases, and when the reverse change was made, the concentration of serum cholesterol increased. Variation in dietary sucrose had no specific effect. Substitution of starch for sucrose with diets otherwise constant did not cause significant change in the concentration of serum cholesterol. When monkeys fed corn oil diets at any of three levels were changed to hydrogenated cottonseed oil diets at the same level, the serum cholesterol and S_f 12 to 100 beta lipoproteins rose. However, hydrogenated cottonseed oil had no greater hypercholesteremic effect than did corn oil in the absence of dietary cholesterol. Diets containing lard with cholesterol also produced strikingly greater serum lipide responses than did diets based on corn oil and cholesterol. Hydrogenated cottonseed oil had a greater hypercholesteremic effect than an unhydrogenated cottonseed oil from the same lot. Preliminary studies indicated that the saturated fats (hydrogenated cottonseed oil) produced the most striking elevation of serum cholesterol values (above controls fed corn oil) when casein was the dietary protein.     

Fractionnement et valorisation de l’huile essentielle de la sciure de bois de Tetraclinis articulata (Vahl) Masters du Maroc

With a view to contributing to the evaluation of Moroccan flora through the identification of new potentially interesting substances at a biological and therapeutic level, we have undertaken a study of the essential oils in the sawdust of the Tetraclinis articulata (Vahl) Masters originating from the Khemisset region (Morocco). The study of the sawdust’s essential oil, completed by CPG and CPG/SM, identified 22 components, the main five being: α-acorenol (20.9%), cedrol (17.9%), totarol (8.8%), α-cedrene (8.7%) and β-acorenol (7.4%). This essential oil was fractionated on an open silica column using an eluent of increasing polarity. Five fractions were collected in this way. The fraction (FH) eluted with the pentane comprised sesquiterpene hydrocarbons whereas the four oxygenated fractions (FO₁ to FO₄) eluted with a diethyl oxide/pentane mix of increasing polarity were dominated by a diterpenoid phenol and two sesquiterpene alcohols respectively: totarol in the FO₁ fraction (42.4%), α-acorenol in the FO₂ (34.9%) and FO₃ (54.0%) fractions, and cedrol in the FO₄ fraction (58.2%). The sawdust’s oil and its chromatographic fractions were tested in vitro against four bacterium: Escherichia coli, Bacillus subtilis, Staphylococcus aureus and Micrococcus luteus, and three funghi: Penicillium parasiticus, Aspergillus niger and Trametes pini. The unfractionated essential oil and oxygenated fractions, particularly FO₁, comprising mainly of totarol, were the most active. Therefore, the FO₁ fraction would be recommended for optimising the antimicrobial activity of the Tetraclinis articulata’s essential oils.     

Lignocellulosic hydrogen production using dark fermentation by Clostridium lentocellum strain Cel10 newly isolated from Ailuropoda melanoleuca excrement

Due to the characteristics of renewable and carbon-neutral, lignocellulose is considered to be one of the most potential, feasible, and ample resources for biofuel production on the Earth. However, the low energy conversion capacity of microorganisms is the primary bottleneck for utilizing lignocellulosic biomass to produce biofuel. In the present study, a mesophilic bacterial strain Cel10 identified as Clostridium lentocellum, according to 16S rRNA sequence homology, which can produce hydrogen from lignocellulose was isolated and characterized. The optimal conditions of hydrogen production from carboxymethylcellulose (CMC) are 37 °C, pH 7.0, and 5.0 g L⁻¹. The H₂ production peaked at 5.419 mmol H₂ g⁻¹ CMC under these conditions, which is relatively high compared to the other reported mesophilic bacteria that use cellulose as a substrate. Moreover, the H₂-producing performance of strain Cel10 using cassava residues, a type of natural lignocellulosic feedstock, was also investigated. The results show that the hydrogen production peaked at 4.08 mmol H₂ g⁻¹ after 72 h of incubation, which is almost 1.2–3.8 times higher than the production of other mesophilic and thermophilic strains, while the highest cassava residues degradation rate reached 45.43%. The results validate that Clostridium lentocellum strain Cel10, newly isolated from Ailuropoda melanoleuca excrement, can offer a new method for directly converting lignocellulosic biomass to bio-hydrogen.

Lignocellulosic biomass, such as cassava residues, rice straw, corn stalks, and corncob, can be directly converted to hydrogen using dark fermentation by newly isolated Clostridium lentocellum strain Cel10.     

An Antiregurgitation Milk Formula in the Management of Infants with Mild to Moderate Gastroesophageal Reflux

Background: Thickened milk formulas are used to treat infants with gastroesophageal reflux (GER), but these substances often increase the duration of reflux episodes and worsen symptoms, and they have been associated with diarrhea, constipation, and cough.Objectives: The aims of this study were to determine the efficacy of an antiregurgitation milk formula in the clinical and laboratory setting in infants with proved GER, to investigate any possible adverse events (cough and change in the number of bowel movements or the consistency of stools), and to identify its effects on height and body weight.Methods: Infants with recurrent vomiting and GER who were not responsive to standard treatment were eligible for the study. Infants in the treatment group (group A) were managed for 4 weeks with a specific antiregurgitation milk formula (with cornstarch and an increased amount of casein), and those in the control group (group B) were given a standard milk formula. The number of episodes of vomiting, regurgitation, and cough, as well as the frequency and consistency of stool, height, and body weight were noted at least 10 days before and during the study. A second pH monitoring was performed after 4 weeks in both groups.Results: Fifty-six infants (30 boys, 26 girls; mean [SD] age, 3.1 [1.2] months) were included in the study; 30.4% had mild GER; 44.6%, moderate GER; and 25.0%, severe GER. Significantly more infants in group A than in group B (50.0% vs 14.3%, respectively) with mild or moderate GER had normal findings on the second pH monitoring (P<0.05). Changes in the reflux index and in the mean number of vomiting and regurgitation episodes were significantly different between the 2 groups (P<0.05). No significant differences in changes in the mean number of bowel movements and cough events or in the consumption time of the 2 formulas were found between the 2 groups.Conclusion: Infants with mild or moderate GER can be managed effectively with this antiregurgitation milk formula. Improved clinical and laboratory findings were seen in the majority of infants, and the formula was well tolerated, without adverse events.     

Diagnosis and treatment of primary pulmonary enteric adenocarcinoma: Report of Six cases

BACKGROUNDPrimary pulmonary enteric adenocarcinoma (PEAC) is a very rare subtype of invasive adenocarcinoma, and there have been no large studies on PEAC to date. Therefore, it is necessary to obtain much more information about the clinical and pathological features, diagnosis, differential diagnosis, and treatment of PEAC.CASE SUMMARYAll clinical data of six patients with confirmed PEAC from 2013 to 2018 were collected, and data on diagnosis, differential diagnosis, and treatment of PEAC are discussed combined with all the associated literature. The mean age of six patients was 64.0 ± 5.6 (59-73) years old. Their clinical manifestations were heterogeneous, and during their disease course, there were no gastrointestinal symptoms. There was no evidence from colonoscopy or imaging studies to suggest digestive tract tumors or new metastases. The most commonly mutated gene was KRAS (50.0%), and the pathological features of the six cases were similar to those of colorectal cancer. CDX2 (83.3%) and CK7 (66.7%) had the highest positive rates upon immunohistochemical examination. In the associated literature, 252 cases were identified, and the most commonly mutated gene was KRAS (42.9%). Additionally, CDX2 (68.3%) and CK7 (85.8%) had the highest positive rates. Patients mainly received surgery, chemotherapy, and radiotherapy, immunotherapy was not included.CONCLUSIONPositive results for CDX2 and CK7 play an important role in the diagnosis and differential diagnosis of PEAC, and immunotherapy or targeted therapy focused on KRAS needs to be further studied for the treatment of PEAC.     

Estimation of Fetal Weight in Fetuses With Abdominal Wall Defects

Objective. Estimation of fetal weight is particularly challenging in fetuses with abdominal wall defects (AWDs). We sought to compare the accuracy and screening efficiency for intrauterine growth restriction (IUGR) of 2 recent sonographic formulas to those of the Hadlock formula (Am J Obstet Gynecol 1985; 151:333–337) in fetuses with AWDs. Methods. This was a retrospective cohort study of fetuses with AWDs. Fetuses with sonographically estimated fetal weights (EFWs) within 14 days before delivery were included. Using the individual biometric measurements, EFWs were calculated using the Honarvar (Int J Gynaecol Obstet 2001; 73:15–20; femur length [FL]), Siemer (Ultrasound Obstet Gynecol 2008; 31:397–400; FL, biparietal diameter [BPD], and occipitofrontal diameter), and Hadlock (BPD, head circumference, abdominal circumference, and FL) formulas. The calculated EFWs were adjusted for interval growth between the dates of sonography and delivery using published sonographic fetal growth velocity standards. Accuracy and screening efficiency for IUGR were compared. Results. Seventy‐six fetuses were included: 53 with gastroschisis and 23 with omphalocele. The median gestational age at delivery was 36.6 weeks (range, 25.0 to 39.0 weeks). The Siemer formula had the lowest mean percentage error (?2.5% [95% confidence interval (CI), ?6.2% to +1.2%]) without systematic bias (P = .182). The Hadlock formula had the highest precision (random error, 11.4%), sensitivity (91%), and accuracy for predicting IUGR (85% [95% CI, 77% to 94%]). Conclusions. None of the 3 sonographic formulas is ideal for estimating fetal weight in fetuses with AWDs. The Siemer formula should be used when accuracy in the absolute EFW is the goal. For the purpose of making the more clinically relevant diagnosis of IUGR, use of the Hadlock formula is justified.     

Comparative analysis on adsorption properties and mechanisms of nitrate and phosphate by modified corn stalks

In this study, modified corn stalks (MCS) were successfully synthesized by grafting or crosslinking triethylenetetramine (TETA) and triethylamine (TEA) in the presence of epichlorohydrin (EPI) and N,N-dimethylformamide (DMF) for the effective removal of nitrate and phosphate. The characteristics of adsorbents were determined and the adsorption properties and mechanisms of nitrate and phosphate on MCS were studied and compared. Results from Zeta potential, elemental analysis (EA), scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR) showed that quaternary ammonium group was successfully grafted onto corn stalks (CS). Both adsorption properties and mechanisms indicated that the MCS had a better affinity to phosphate. For adsorption properties, under conditions of a dosage of 4 g L⁻¹, pH 6.0 and an initial concentration of 50 mg L⁻¹, the phosphate removal rate was 10.97% higher than that nitrate, and SO₄²⁻ and Cl⁻ had a larger inhibitive effect on nitrate. Mechanisms analysis included adsorption kinetics, isotherm and thermodynamics. Results indicated that the parameters of different models were closely related to the adsorption effect of nitrate and phosphate. In addition, pseudo-second-order and Freundlich model fitted both nitrate and phosphate adsorption well. The thermodynamics analysis indicated that the adsorption process was spontaneous and endothermic in nature.

We compare and analyze the different properties and mechanisms of MCS on nitrate and phosphate.     

Comparison of CD44 and cytokeratin 20 mRNA in voided urine samples as diagnostic tools for bladder cancer

ObjectivesWe evaluated the diagnostic efficacy of urinary CD44 and cytokeratin 20 (CK20) mRNA in comparison with voided urine cytology (VUC) for the detection of bladder cancer.Design and methodsA total of 136 Egyptian patients provided a single voided urine sample for CD44, CK20 mRNA and VUC before cystoscopy. Of the 136 cases, 111 were histologically diagnosed as bladder cancer whereas the remaining 25 had benign urological disorders. A group of 20 healthy volunteers was also included in this study. Voided urine was centrifuged and the urine sediment was used for cytology, estimation of CD44 by ELISA and RNA extraction. CK20 mRNA was detected by conventional RT-PCR and quantitative real-time RT-PCR.ResultsThe best cutoff values for CD44 and relative CK20 mRNA detected by real-time RT-PCR were calculated by receiver operating characteristic curve. The positivity rates and the mean ranks for CD44 and CK20 mRNA showed significant difference among the three investigated groups (p = 0.001). Quantitative real-time RT-PCR results were comparable to conventional RT-PCR for the detection of CK20 mRNA. The positivity rate of CD44 was significantly associated with schistosomiasis and urine cytology. The overall sensitivity and specificity were 52.3% and 88.9% for VUC, 63.1% and 88.9% for CD44, and 82.0% and 97.8% for CK20 mRNA. Combined sensitivity of VUC with CD44 and CK20 mRNA together (95.5%) was higher than either the combined sensitivity of VUC with CD44 (78.4%) or with CK20 mRNA (91.0%) or than that of the biomarker alone.ConclusionUrinary CD44 and CK20 mRNA had higher sensitivities compared to VUC. However, when the diagnostic efficacy was considered, CK20 mRNA by either conventional RT-PCR or real-time RT-PCR had the highest sensitivity and specificity compared to CD44 and VUC.     

Comparison of the Verigene Clostridium difficile, Simplexa C. difficile Universal Direct,BD MAX Cdiff,and Xpert C. difficile assays for the detection of toxigenic C. difficile

We compared the Verigene Clostridium difficile test (Nanosphere, Northbrook, IL, USA), the Simplexa C. difficile Universal Direct (Focus Diagnostics, Cypress, CA, USA), the BD MAX Cdiff (Becton Dickinson, Franklin Lakes, NJ, USA), and the Xpert C. difficile (Cepheid, Sunnyvale, CA, USA) assays for the detection of toxigenic C. difficile. One hundred and ninety deidentified, remnant diarrheal specimens were included in this study. After resolution of discordant results by toxigenic culture, the Xpert C. difficile assay displayed the highest sensitivity (100%), with a specificity of 98.8%. The sensitivity and specificity were 95.2% and 99.4% and 87% and 100% for the Verigene CDF and Simplexa Universal Direct assays, respectively. Finally, the BD MAX assay showed a sensitivity of 87% and a specificity of 98.8%. Despite differences in the overall performance of these assays, these results support the routine use of these platforms for the detection of toxigenic C. difficile in the clinical laboratory.     

The origin of a cathode-migrating creatine kinase found in serum from a cancer patient

The origin of an atypical creatine kinase (CK, ATP:creatine W-phosphotransferase, EC 2.7.3.2) migrating cathodic to the MM position found in the serum of a cancer patient was studied. The electrophoretic mobility of the atypical CK is similar to that of the fast-moving cathodal mitochondrial CK. The relative molecular mass was estimated to be approximately 350000, and was similar to that of the fast-moving cathodal mitochondrial CK. The atypical CK reacted with anti-human mitochondrial CK antibody. It is therefore suggested that the atypical CK is of mitochondrial origin.After incubation in 2 mol/l urea, the enzyme was converted into a new form migrating to the MM position. The conversion was observed in liver mitochondrial CK but not heart mitochondrial CK. The residual CK activity after heating at 56°C for 60 s was 77%, and the apparent K_m value for creatine phosphate at 30°C was about 0.27 mmol for the atypical CK. These characteristics were very similar to those of the liver mitochondrial CK, because the data from the enzyme determined at the same time were 75% for residual enzyme activity to heat, and 0.24 mmol for apparent K_m value. Therefore liver mitochondria are suggested to be the source of the atypical CK.     

数学模型在α珠蛋白生成障碍性贫血筛查中的价值

目的 探讨红细胞参数的数学模型在α珠蛋白生成障碍性贫血(旧称:α地中海贫血)筛查中区分α珠蛋白生成障碍性贫血合并缺铁与缺铁性贫血的价值.方法 利用红细胞参数进行逐步logistic回归模型分析,建立本实验室区分α珠蛋白生成障碍性贫血合并缺铁与缺铁性贫血的鉴别数学模型,并与国外6种红细胞参数的数学模型进行比较.结果 α珠蛋白生成障碍性贫血合并缺铁者7种红细胞参数的数学模型与缺铁性贫血者比较,差异均有统计学意义(P<0.01),鉴别数学模型在区分α珠蛋白生成障碍性贫血合并缺铁与缺铁性贫血时鉴别效果 (AUC=0.95)及一致性(Kappa=0.813)较其他数学模型高,Green指数的敏感度最高(96.7%),Shine and Lal指数特异度最好(94.7%).结论 红细胞参数的数学模型在区分α珠蛋白生成障碍性贫血合并缺铁与缺铁性贫血方面具有较高的鉴别价值.     

STUDIES ON THE CULTIVATION OF THE TYPHUS FEVER RICKETTSIA IN THE PRESENCE OF LIVE TISSUE

1. Rickettsia prowazeki can be cultivated for many generations in vitro, without diminution in numbers or virulence, in media similar to those described by Maitland, Rivers, and others for the cultivation of certain viruses. In all probability, such cultures can be maintained indefinitely. 2. It has been impossible, thus far, to cultivate the typhus rickettsia without employing living tissue.     

Comparison of serum creatine kinase and creatine kinase MB activities post marathon race versus post myocardial infarction

Serial total creatine kinase (CK) and CK MB activities were determined in the serum of seven runners following a marathon race and compared to enzyme activities in the sera from five patients following acute myocardial infarction (AMI). In the runner's sera, total CK and CK MB activities were significantly elevated at 1, 24, 48 and 72 hours post marathon race when compared to the 1 hour pre-marathon samples (p < 0.01). Serum CK MB activities peaked at 24 hours in both groups of subjects. The MB activities 24 hours following the marathon were substantially higher (91 ± 30 U/l; mean ± SD) than the MB activities 24 hours following AMI (46 ± 38 U/l). However, the percentages of CK MB 24 hours following the marathon and AMI were almost identical (7.0 ± 2.4% and 7.2 ± 2.3%, respectively). Furthermore, CK and CK MB clearances were significantly prolonged (p < 0.02 and p < 0.001, respectively) following the marathon race (T $\text{1}\text{2}$ CK, 49 hours; T $\text{1}\text{2}$ CK MB, 29 hours) as compared to following AMI (T $\text{1}\text{2}$ CK, 27 hours; T $\text{1}\text{2}$ CK MB, 12 hours). These results suggest release of CK MB from the skeletal muscle of marathon runners. Therefore, we recommend that elevation of CK MB in the range indicative of myocardial damage be interpreted with caution in long-distance runners.