[Research on the framework of biosafety standards for pathogenic microbial laboratories].

Developing and implementing biosafety standards for pathogenic microbiology laboratories is essential to achieving scientific, efficient, and standardized management and operation. This article analyzes the current standardization construction in biosafety in pathogenic microbiology laboratories domestically and internationally. It proposes a framework for the biosafety standard system of pathogenic microbiology laboratories, which mainly includes four parts: basic standards, management standards, technical standards, and industry applications. It provides a reference for the standardization work of pathogenic microbiology laboratories and helps to standardize the biosafety industry in China.

[Clinicopathological observation of 10 cases of salivary secretory carcinoma].

Objective: To investigate the clinical and pathological features of salivary secretory carcinoma (SSC). Methods: Ten cases of SSC confirmed in the Department of Pathology,Capital Medical University School of Stomatology from January 2014 to December 2021 were retrospectively included, including 5 males and 5 females, with a median age of 46.5 years. The microscopic morphology, immunophenotype, special staining and clinical follow-up of 10 cases of salivary secretory carcinoma were observed. Ten patients were tested with S-100, vimentin, mammaglobin, Dog-1, p63 and Ki-67, 9 cases with cytokeratin (CK) 8/18, 8 with CK7, 6 with calponin, 5 with smooth muscle actin (SMA) and GCDFP15, 4 with CK5/6 and 1 with SOX10. The ETV6-NTRK3 fusion gene was detected by fluorescence in situ hybridization. Results: Seven of the 10 SSC were located in the parotid gland and 3 were located in the cheeks. Histomorphology showed solid, papillary-cystic, follicular, microcystic, and macrocystic types. In 7 cases, tumor cells were dominated by single arrangement type, while certain mixed arrangements existed in some areas. The cytoplasm of the tumor cells was rich in eosinophilic, fine granular or vacuolar shapes, and clear cytoplasm was seen in 2 cases. The nuclei were mostly oval-shaped vesicular nuclei, with nucleoli in the center. Immunohistochemistry showed CK7 (8/8) positive, CK8/18 (9/9) positive, S-100 (10/10) positive, vimentin (5/10) positive, (4/10) partially positive and (1/10) less partially positive, mammaglobin (7/10) positive, (1/10) partially positive and (2/10) some individual cells positive, Dog-1 (10/10) negative, CK5/6 (4/4) negative, p63 (7/10) negative and (3/10) partially positive, SMA (5/5) negative, calponin (6/6) negative, and Ki-67 index was 5%-20%. Secretions of 5 cases showed periodic acid-Schiff (PAS) and PAS with diastase (PAS-D) staining positive. All 10 cases showed ETV6-NTRK3 fusion positive. Six cases were successfully followed up for 32-91 months, of which 2 cases recurred after 28 and 74 months and underwent surgical resection again. All cases followed up are alive and disease-free. Conclusions: The salivary secretory carcinoma is a rare low-grade malignant tumor. In certain cases, morphology is atypical and mammaglobin is immunohistochemically positive in only individual tumor cells. Therefore, the diagnosis should be supported with morphology, immunohistochemical staining, and molecular feature preferably.

[Analysis of clinical characteristics and prognosis of 235 pancreatic neuroendocrine tumors underwent Sunitinib treatment].

Objective: To investigate the clinical characteristics, treatment, and prognostic factors of pancreatic neuroendocrine tumors (pNETs) patients treated with Sunitinib. Methods: The clinical data of pNETs patients from Pfizer Drug Assistance Program of Cancer Foundation of China from April 2013 to November 2017 were retrospectively analyzed. Follow-up and statistical analysis were performed. Results: A total of 235 patients were enrolled, the patients' overall survival time was between 4 and 252 months, the 3-years and 5-years survival rates were 73.8% and 60.8%, respectively. Univariate analysis showed that factors such as age, Ki-67 index and surgery were associated with the 3-years survival rates of pNETs patients (P<0.05). Multivariate analysis demonstrated that the age, Ki-67 index and surgery were independent prognostic factors for pNETs patients (P<0.05). For patients with liver metastases, univariate analysis revealed that surgery was associated with prognosis (P<0.05). The 5-years survival rate of 124 patients with extending usage of Sunitinib was 53.3%. Conclusion: PNETs are rare tumors with atypical clinical symptoms and the patients often have metastasis at the initiate diagnosis. The age, Ki-67 index and surgery are associated with the prognosis of pNETs patients.

Knockdown of lncRNA XIST inhibits hypoxia-induced glycolysis, migration and invasion through regulating miR-381-3p/NEK5 axis in nasopharyngeal carcinoma.

OBJECTIVE: Hypoxia is an important feature of nasopharyngeal carcinoma (NPC). Growing evidence demonstrated that long non-coding RNAs (lncRNAs) could participate in cancer progression and hypoxia regulation. However, the exact roles and underlying mechanism of lncRNA X-inactive specific transcript (XIST) in NPC under hypoxia are still unclear. MATERIALS AND METHODS: The expressions of XIST, microRNA-381-3p (miR-381-3p) and NIMA related kinase 5 (NEK5) were detected by quantitative Real-time polymerase chain reaction (qRT-PCR). The glucose consumption and lactate production were measured using the glucose assay kit and lactate assay kit, respectively. Western blot assay was used to determine the protein levels of hexokinase II (HK2) and NEK5. Transwell assay was employed to evaluate cell migration and invasion. The interaction between miR-381-3p and XIST or NEK5 was predicted by bioinformatics analysis and verified by dual-luciferase reporter assay. The mice xenograft model was established to investigate the roles of XIST in NPC progression in vivo. RESULTS: XIST and NEK5 were highly expressed while miR-381-3p was lowly expressed in NPC (tissues and cells) and hypoxia-induced NPC cells. Deficiency of XIST or NEK5 suppressed hypoxia-induced glycolysis and metastasis in NPC cells. Moreover, miR-381-3p could directly bind to XIST and its inhibition reversed the inhibitory effects of XIST knockdown on glycolysis and metastasis under hypoxia. NEK5 was a direct target of miR-381-3p and its interference attenuated the promotive effects of miR-381-3p downregulation on glycolysis and metastasis under hypoxic conditions. Besides, interference of XIST decreased tumor growth by upregulating miR-381-3p and downregulating NEK5. CONCLUSIONS: XIST knockdown inhibited glycolysis and metastasis in hypoxia-induced NPC cells through regulating miR-381-3p/NEK5 axis, providing new insights into the pathogenesis of NPC.

[Reproductive and developmental toxicity of 2- (2H-1, 2, 3-benzotriazol-2-yl) -4-methyl-6- (2-methylpropen-2-yl) phenol in mice: an experimental study].

Objective: To investigate the reproductive and developmental toxicity of 2- (2H-1, 2, 3-benzotriazol-2-yl) -4-methyl-6- (2-methylpropen-2-yl) phenol in mice and to provide a basis for its risk assessment. Methods: The reproductive and developmental toxicity of 2- (2H-1, 2, 3-benzotriazol-2-yl) -4-methyl-6- (2-methylpropen-2-yl) phenol was tested using the screening method of chemicals with reproductive and developmental toxicity in "Chemical Testing Method" (SEPA). After five days of adaptive feeding, 120 specific pathogen-free healthy Kunming mice (male/female ratio=1:1) were orally administered 0 (control) , 146, 292, and 584 mg/kg 2- (2H-1, 2, 3-benzotriazol-2-yl) -4-methyl-6- (2-methylpropen-2-yl) phenol for two weeks. One male mouse was mated with one female mouse in a single cage. The day on which a vaginal plug was observed was defined as gestation day 0 (GD0). The exposure for female mice was sustained to four days postpartum and the exposure for male mice was sustained for two weeks after mating. The body weight, food intake, body length, tail length, and sex ratio were recorded and the reproductive index was calculated. The reproductive organs were weighed and subjected to histopathological examination. Results: The 584 mg/kg group had significantly lower body weight at weeks 5 and 6 and food intake at week 6 in male mice, uterus weight and uterus/body weight ratio in female mice, and body weight, body length, and tail length on day 0 in offspring compared with the control group (all P<0.05). The 292 mg/kg group had significantly lower testis weight of male mice and food intake of female mice at gestational week 2 than the control group (both P<0.05). The 146 mg/kg group had significantly lower food intake of female mice at gestational week 2 than the control group (P<0.05) . Conclusion: For male and female Kunming mice, the no observed adverse effect levels of 2- (2H-1, 2, 3, -benzotriazol-2-yl) -4-methyl-6- (2-methylpropen-2-yl) phenol are both 146 mg/kg.

[A cross-sectional study of seroepidemiology of viral hepatitis among Uighurs in Shufu of Xinjiang].

Objective: To explore the status of seroepidemiology on hepatitis A, B and C among students and residents aged equal or greater than 18 years in south Xinjiang, and to provide scientific evidence for prevention and control of viral hepatitis. Methods: Uyghur students in four towns and villages were selected by cluster random sampling from Feb to May, 2015, and Uyghur residents aged 18 to 69 years were selected by stratified cluster sampling from May to September, 2016. 4 507 middle and primary Uygur students and 4 833 Uyghur resides equal or greater than 18 years attended this survey. Self-designed questionnaire was used to collect the demographic information. And Elisa test was adopted to detect HAV-IgG, HBsAg, HBsAb and HCV-IgG. Chi-square test was used to calculate the difference on antibody positive rate of three types of hepatitis among the participants. Results: The overall HAV-IgG positive rate was 99.45% (9 289/9 340). The positive rates were 99.70% (4 006/4 018) in male and 99.27% (5 283/5 322) in female (χ(2)=7.95, P=0.005). The HAV-IgG positive rate among people aged 10 to 14 years was the highest (99.91%, 2 233/2 235), and the difference between the age specific HAV-IgG positive rates was statistical significant (χ(2)=38.21, P<0.001). The overall HBsAg positive rate was 4.11% (384 cases), with 4.55% (183 cases) for male and 3.78% (201 cases) for female. The HBsAg positive rate among participants 19 to 24 years old was the highest (9.46%, 21/222) and the differences between the age specific HBsAg was statistically significant (χ(2)=116.22, P<0.001). The HBsAb positive rate was 35.03% (3 272 cases), with 35.59% (1 430 cases) for male and 34.61% (1 842 cases) for female, and the HBsAb positive rate among participants aged 15 to 18 years was the highest, which was 69.12% (696/1 007). The differences between the age specific HBsAb rates appeared statistically significant (χ(2)=671.80, P<0.001). The overall HCV-IgG positive rate was 0.65%(61 cases). The HCV-IgG positive rate in female was 0.86% (46 cases) and 0.37% (15 cases) in male (χ(2)=8.51, P=0.004).The HCV-IgG positive rate among participants aged over 70 years was the highest (3.78%,9/238) , and the difference between the age specific HCV-IgG positive rates had statistic significance (χ(2)=70.30, P<0.001). The HAV-IgG positive rate in hepatitis A vaccinees (100%, 876/876) was higher than that among the non-vaccinees (99.40%, 8 413/8 464) (χ(2)=4.26, P=0.039). The HBsAb positive rate in hepatitis B vaccinees was 39.32% (1 816/4 619) which was higher than that among the non-vaccinees (30.84%, 1 456/4 721) (χ(2)=73.68, P<0.001). Conclusion: The positive rate of overall HAV-IgG was high, male and participants aged between 10 to 14 had higher probability to be infected. But the infection rates of hepatitis B and C were low, with the low vaccination rate and the poor protective effectiveness of hepatitis B.

Mechanisms of propofol attenuation of ketamine-induced neonatal brain injury.

OBJECTIVE: We studied the mechanisms of protective effects of propofol on ketamine-induced damage to neonatal cognitive function. MATERIALS AND METHODS: We utilized a rat model of ketamine anaesthesia. Eighty neonatal rats (7 days after birth) were divided into four groups: normal saline group, ketamine group, and low- and high-dose propofol combined with ketamine groups. Six hours after anaesthesia, we obtained hippocampal tissue, and quantified apoptotic index and total protein concentration, and assessed global proteomics changes induced by two tested drugs. The latter changes were documented by two-dimensional electrophoresis and matrix-assisted laser desorption/ ionization time of flight mass spectrometry. To evaluate cognitive functions, water maze test was applied after animals grew for 21 days. We further repeated proteomics studies at 21 days post-anaesthesia. RESULTS: Ketamine markedly up-regulated apoptotic index and decreased total protein concentration. Propofol dose-dependently reverted these adverse changes. Six hours post-anaesthesia, combined propofol and ketamine administration up-regulated the following proteins in the hippocampus: PD1A3, NDUFB10, HSPA8, ATP5JD, and PSMA1. Furthermore, the following proteins were down-regulated: PPIA, PKM2, GFAP, NSE, PPIA, PKM2, and GFAP. After 21 days, animals treated with ketamine showed marked disturbances in cognitive function as demonstrated by increased time of the water maze test, whereas propofol diminished these changes. In addition, expression of proteins largely normalized in propofol-treated animals, with only two up-regulated proteins (FUBP3 and PRDX5) and three down-regulated proteins (GAPDH, AKR1A1, and VCP). CONCLUSIONS: Adverse effects of ketamine on cognitive function are reverted by propofol, also through beneficial effects on protein expression in the hippocampus.

Patients with brain metastases derived from gastrointestinal cancer: clinical characteristics and prognostic factors.

PURPOSE: This study seeks to evaluate the natural history, outcome, and possible prognostic factors in patients with brain metastases derived from gastrointestinal cancers. METHODS: The clinical features, prognostic factors, and the effects of different treatment modalities on survival were retrospectively investigated in 103 patients with brain metastases derived from gastrointestinal cancers. RESULTS: The median time from diagnosis of primary tumor to brain metastasis was 22.00 months. The interval between diagnosis of primary tumor relapse and brain metastasis was 8.00 months. The median follow-up time was 7.80 months. The median survival time after diagnosis of brain metastases was 4.10 months for all patients and 1.17 months for patients who received only steroids (36.9 %), 3.97 months for patients who only received whole-brain radiation therapy (WBRT 31.1 %), 11.07 months for patients who received gamma-knife surgery alone or/and WBRT (20.4 %), and 13.70 months for patients who underwent surgery and radiotherapy (12 patients, 11.6 %) (P < 0.001). Multivariate analysis revealed that recursive partitioning analysis (RPA) class, extracranial metastasis, and chemotherapy were independent prognostic factors. Brain metastasis derived from gastrointestinal tract cancer is rare, and overall patient survival is poor. CONCLUSION: RPA class, chemotherapy after brain metastases, and treatment regimens were independent prognostic factors for the survival of patients with brain metastases derived from gastrointestinal cancers.

Analysis and clinical significance of microRNA-499 expression levels in serum of patients with acute myocardial infarction.

The aim of this study was to investigate the expression level of microRNA-499 and its clinical significance in serum of patients with acute myocardial infarction (AMI). We recruited 59 patients with AMI and 60 healthy individuals undergoing physical examination in our hospital during the same period as controls. Peripheral blood was drawn in the morning on the same day of microRNA extraction. The expression level of microRNA-499 was analyzed by real-time fluorescent quantitative polymerase chain reaction (qPCR). The sensitivity and specificity of the clinical diagnosis of AMI were analyzed by a receiver operating characteristic (ROC) curve. Fluorescent qPCR analysis showed that the expression of microRNA-499 in serum of patients with AMI was significantly higher than in controls (P < 0.05). MicroRNA-499 was detected in blood serum 3 h post-AMI, reaching a peak after 12 h and declining after 15 h. The area under the ROC curve (AUC) for the gold standard cardiac troponin I (cTnI) was 0.971 [95% confidence interval (CI): 0.951-1.000], and for the microRNA-499, AUC = 0.915 (95%CI: 0.826-1.000). When the microRNA-499 levels in patient and control (> 1.5) sera were compared, the sensitivity of microRNA-499 in judging AMI was found to be 86.37% and the specificity was 93.47%. Our results demonstrated that the expression levels of microRNA-499 in serum of patients with AMI were abnormal. Its high sensitivity and specificity for the diagnosis of AMI suggest that it would be useful as an auxiliary index for clinical diagnosis of AMI.

Controllable surface morphology and properties via mist polymerization on a plasma-treated polymethyl methacrylate surface.

Surface modification by grafting polymers on solid materials is an important strategy used to improve surface properties. This article reports that under appropriate conditions, very thin layers with desired morphologies may be constructed on a plasma-treated substrate by feeding a small quantity of a monomer with a mist stream carrying droplets produced from monomer solutions. We investigate the effects of process parameters that affect layer morphology, including exposure time to the mist stream, concentration of the monomer solution, and solvent selectivity. For a methyl methacrylate solution in ethanol, nanoparticles are uniformly grown with increasing monomer concentration or exposure time and finally form a porous layer at 3.65 mol L(-1) for 30 min. Decreasing solvent polarity not only affects surface morphology, but also increases hydrophobicity of the resulting surface. With 2,2,3,4,4,4-hexafluorobutyl methacrylate as the monomer, SEM and AFM micrographs indicated that mist polymerization results in numerous microspheres on the activated surface. These experimental results were interpreted by a mechanism in terms of an in situ polymerization accompanied by a phase transformation of the resulting polymer. Specifically, plasma treatment provides highly active cations and radicals to initiate very rapid polymerization, and the resulting polymers are consequently deposited from the liquid onto the surface under phase transition mechanisms.

Bioethanol production from hydrolysates of inulin and the tuber meal of Jerusalem artichoke by Saccharomyces sp. W0.

It has been confirmed that Saccharomyces sp. W0 can produce high concentration of ethanol. However, this yeast strain cannot secrete inulinase. Therefore, in this study, inulin was hydrolyzed into reducing sugar by the recombinant inulinase produced by Pichia pastoris X-33/pPICZaA-INU1. It was found that 38.2U of the recombinant inulinase per gram of inulin was suitable for the inulin hydrolysis and ethanol production by Saccharomyces sp. W0 and the fermentation period was 120 h. At the end of the fermentation, over 14.6 ml of ethanol per 100ml of the fermented medium was produced, the ethanol productivity was over 0.384 g of ethanol/g of inulin and over 98.8% of total sugar was utilized. When the Saccharomyces sp. W0 was grown in the mixture of 4.0% hydrolysate of soybean meal and 20.0% of the hydrolysate of inulin for 120 h, over 14.9 ml of ethanol per 100ml of the fermented medium was yielded, the ethanol productivity was over 0.393 g of ethanol/g of inulin and 98.9% of total sugar was used by the yeast strain. When Saccharomyces sp. W0 carrying the same inulinase gene was grown in the medium containing 50 g of the tuber meal of Jerusalem artichoke per 100ml for 144 h, over 12.1+/-0.35%ml of ethanol per 100ml of the fermented medium was yielded, the ethanol productivity was 0.319+/-0.9 g of ethanol/g of sugar and 3.7% (w/v) of total sugar and 0.5% (w/v) of reducing sugar were left in the fermented media.

Expressions of 5-HT/5-HT(2A) receptors and phospho-protein kinase C theta in the pre-Bötzinger complex in normal and chronic intermittent hypoxic rats.

The pre-Bötzinger complex (pre-BötC), a functionally defined subregion in the ventrolateral medulla oblongata, is a presumed kernel of normal respiratory rhythmogenesis. However, less is known about the pre-BötC's contribution to respiratory neuroplasticity. The most frequently studied model for respiratory neuroplasticity is episodic hypoxia-induced phrenic long-term facilitation, which is 5-HT(2A) receptors (5-HT(2A)R)-dependent. We hypothesized that preconditioning with chronic intermittent hypoxic (CIH) would activate the 5-HT/5-HT(2A)R system and the downstream protein kinase C (PKC) pathway in the pre-BötC. Animals were exposed to alternating 5 min of hypobaric hypoxia and 5 min of normoxia for 10 h/day for 7 days. Hypobaric hypoxia was achieved by continuous air evacuation to reach a pressure of 210-220 mm Hg, corresponding to an altitude of 9000-10000 m. In contrast to the CIH model, a group of animals were pretreated with chronic sustaining hypoxia (CSH), a protocol of continuous hypobaric hypoxia at 360 mm Hg, corresponding to an altitude of about 6000 m, for 10 h/day for 7 days. Immunoreactivity of 5-HT and 5-HT(2A)R was examined in the pre-BötC, identified by the presence of neurokinin-1 receptor (NK1R). We found that 15.5% of 5-HT-immunoreactive (ir) terminals were in contact with NK1R-ir neurons. Asymmetric synapses could be identified between them. 38.7% of NK1R-ir dendrites were also immunoreactive for 5-HT(2A)R, which was distributed along the inner surface of the plasma membrane in control animals. CIH challenge increased the expressions of 5-HT and 5-HT(2A)R in the pre-BötC, an increase in the expressed 5-HT(2A)R that was not detected in this region in CSH animals. Specifically, 5-HT(2A)R was distributed not only along the inner surface, but also along the outer surface, or directly on the plasma membrane, a pattern not detectable in control animals. 5-HT(2A)R was also detectable in the invaginations of the plasma membrane, where receptor endocytosis or exocytosis might occur, indicating CIH-induced higher trafficking of 5-HT(2A)R. Concurrently, there was an up-regulation of phospho-PKC theta (P-PKCtheta) in the pre-BötC, suggesting a 5-HT/5-HT(2A)R-activated PKC mechanism that may contribute to hypoxia-induced respiratory neuroplasticity in the pre-BötC. The close association of P-PKCtheta with the postsynaptic density implicates a postsynaptic mechanism mediating respiratory neuroplasticity in the pre-BötC.

Influence of wastewater composition on biological nutrient removal in UniFed SBR process.

The effects of influent C/N ratio and C/P ratio on biological nutrient removal performance were investigated in a lab-scale UniFed SBR apparatus treating real domestic wastewater. The results showed that TN removal efficiency increased as C/N ratio increased from 43.6% at 2.8 to 80.8% at 5.7. But when C/N ratio increased further, TN removal efficiency increased very slowly. This was because when C/N ratio was higher than 5.7, complete denitrification in the sludge blanket during feed/decant period had been achieved, TN removal efficiency during this period always kept the maximum value and only TN removal efficiency during aeration period rose as C/N ratio increased. PO(4) (3-) removal efficiency increased as C/N ratio increased from 27.3% at 2.8 to 88.1% at 5.7. When C/N ratio was 6.5 and above, PO(4) (3-) concentration couldn't be detected in the effluent. When influent C/N ratio and volumetric exchange ratio were fixed at 6 and 33% respectively, as C/P ratio was higher than 33, PO(4) (3-) concentration of effluent always remained below the detection level and phosphorus removal efficiency kept stable at 100%, but as the C/P ratio was lower than 33, phosphorus removal efficiency increased as C/P ratio increased linearly. C/P ratio hardly affected TN removal efficiency, which always kept at 82.2%-85.8% in this study.

6-Hydroxydopamine-induced alterations in blood-brain barrier permeability.

Vascular inflammation is well known for its ability to compromise the function of the blood--brain barrier (BBB). Whether inflammation on the parenchymal side of the barrier, such as that associated with Parkinson's-like dopamine (DA) neuron lesions, similarly disrupts BBB function, is unknown. We assessed BBB integrity by examining the leakage of FITC-labeled albumin or horseradish peroxidase from the vasculature into parenchyma in animals exposed to the DA neurotoxin 6-hydroxydopamine (6OHDA). Unilateral injections of 6OHDA into the striatum or the medial forebrain bundle produced increased leakage in the ipsilateral substantia nigra and striatum 10 and 34 days following 6OHDA. Microglia were markedly activated and DA neurons were reduced by the lesions. The areas of BBB leakage were associated with increased expression of P-glycoprotein and beta 3-integrin expression suggesting, respectively, a compensatory response to inflammation and possible angiogenesis. Behavioural studies revealed that domperidone, a DA antagonist that normally does not cross the BBB, attenuated apomorphine-induced stereotypic behaviour in animals with 6OHDA lesions. This suggests that drugs which normally have no effect in brain can enter following Parkinson-like lesions. These data suggest that the events associated with DA neuron loss compromise BBB function.

Analysis of lactate dehydrogenase activities and isoenzyme patterns in colorectal cancer tissues.

AIM: To investigate the relationship between lactate dehydrogenase (LDH) activity or LDH isoenzyme patterns and the pathogenesis of colorectal cancer. METHODS: Activities of tissue LDH and LDH isoenzyme patterns in 16 patients with colorectal cancer were assayed using spectrophotometric procedures and agarose gel electrophoresis, respectively. RESULTS: The total and specific activities of LDH were significantly higher in colorectal cancer tissues than those in adjacent noncancerous tissues (P < 0.001). The LDH isoenzyme pattern was also different from that in the control. The percentage of LDH5 doubled and the ratio of LDH4 + LDH5/LDH1 + LDH2 was 3.6 ± 1.4 in cancer tissue, significantly greater than in the control. CONCLUSIONS: The increased LDH activity in colorectal cancer tissues resulted mainly from the increased LDH5, suggesting that the alteration of LDH activity and isoenzyme patterns were related to the pathogenesis of colorectal cancer.

Substrate specificity of acetyltransferase and reductase enzyme systems used in pheromone biosynthesis by Asian corn borer,Ostrinia furnacalis.

The substrate specificity of the acetyltransferase and the reductase enzyme systems used byOstrinia furnacalis (Lepidoptera: Pyralidae) in pheromone biosynthesis was studied in vivo by topical application of precursors to pheromone glands. Each of the tetradecenols, varying in double bond position (from 7 to 13) and geometry of the double bond, was converted to the corresponding acetate by the acetyltransferase. The similarity in the conversion rates of all tested fatty alcohols indicated that the acetyltransferase has a low substrate specificity. Most of the corresponding tetradecenoic acids could also be converted to the respective acetates. However, very different conversion rates among the tested fatty acids demonstrated that the reductase system has a higher substrate specificity than the acetyltransferase. The conversion rates of mostE isomers were higher than those of the correspondingZ isomers, except for the (Δ)-11-tetradecenoic acids, in which much moreZ isomer was converted to the product. Saturated tetradecanoic acid was converted to the corresponding acetate at a high rate; the shorter homolog, tridecanoic acid, was converted at a lower rate (56%), and conversion to the respective acetates of the longer homolog, pentadecanoic and hexadecanoic acids, was insignificant (<5%). The results from the present study showed that specificity of pheromone production is to a large extent controlled by the pheromone gland reductase system.

Components of moribund American elm trees as attractants to elm bark beetles,Hylurgopinus rufipes and Scolytus multistriatus.

Hylurgopinus rufipes male and female beetles were attracted to American elms infected with Dutch elm disease, and to American elms killed by injection of cacodylic acid.H. rufipes was also attracted to solvent extracts of elm, or to Porapak Q-trapped volatiles from elm. The major components of attractive fractions of Porapak Q-trapped volatiles were isolated, identified, and tested in field bioassays. Several artificially compounded mixtures of sesquiterpenes were attractive toH. rufipes, although no bait tested was as attractive as diseased tree controls. Laboratory bioassays with H. rufipes were marginally successful. In laboratory bioassays, nine of 14 sequiterpenes identified from active fractions of Porapak extracts elicited significant response from Scolytus multistriatus male and female beetles: δ- and γ-cadinene, α-cubebene, γ-muurolene, and ß-elemene were most active. However, in field tests, none of the sesquiterpenes alone or in combination significantly attracted S. multistriatus, nor did they significantly enhance the attraction of S. multistriatus to female-produced pheromone components (4-methyl-3-heptanol [H] and α-multistriatin [M]). In other field tests, α-cubebene (C) significantly enhanced response of S. multistriatus to H plus M, but foliage, logs, or chips of healthy elm did not enhance trap catch to HMC.