[Contrastive study on MRI signs of intestinal and pancreatobiliary-type periampullary carcinoma].

Objective: The magnetic resonance imaging (MRI) features of intestinal-type periampullary carcinoma (IPAC) and pancreatobiliary-type periampullary carcinoma (PPAC) were compared and analyzed to discuss the optimal diagnosis scheme. Method: Preoperative MRI images of 59 patients (32 males, 27 females, aged 37-80 years) diagnosed with periampullary carcinoma (PAC) confirmed by surgery and pathology in Nanjing Drum Tower Hospital from January 2017 to July 2020 were retrospectively analyzed. The patients were divided into 21 cases in the IPAC group (11 males, 10 females) and 38 cases in the PPAC group (21 males, 17 females) according to histopathological results. The conventional MRI plain scan signs included in the analysis include lesion morphology, the largest diameter of the lesion, lesion location, duodenal papilla morphology, plain scan lesion signal (with the normal pancreatic signal as reference), diffusion weighted imaging (DWI) signal. Magnetic resonance cholangiopancreatography (MRCP) image signs include the dilatation of common bile duct and main pancreatic duct and quantitative analysis of their diameter, the presence of a round filling defect in the distal end of the common bile duct, the morphology of common bile duct stenosis, the dilatation of lateral branches around the obstructed pancreatic duct, the ductal sign, the distance from the end of the obstructed common bile duct to the duodenal papilla, the distance from the end of the obstructed pancreatic duct to the duodenal papilla, and the angle of the pancreaticobiliary duct. The receiver operating characteristic (ROC) curve was used to evaluate the diagnostic efficacy of single meaningful factors. The MRI features of PAC were summarized according to the significant single factor indicators and were classified into 5 image types. And the diagnostic efficacy of the classification criteria for pathological subtypes of PAC was evaluated by the ROC curve. The DeLong test was used to compare the area under the ROC curve (AUC) of multiple diagnostic methods. Results: In univariate analysis, there were statistically significant differences between IPAC and PPAC in lesion location, duodenal papilla morphology, the circular filling defect in the distal end of the common bile duct, the distance from the obstructed pancreatic duct to the duodenal papilla, the angle of the pancreaticobiliary duct, and lesion signal characteristics on plain T2WI fat suppressant images (all P<0.05). Among the 5 types of MRI images, IPAC is mostly manifested as duodenal papillary nodules(15/21,71.4%), while PPAC is more manifested as pancreatic mass type(18/38,47.4%), thickened common bile duct wall type(9/38,23.7%) or ampullary mass type(9/38,23.7%). Both IPAC(2/21,9.5%) and PPAC(0,0) rarely showed the nodular type of common bile duct lumen. In the DeLong test of the significant univariate index(lesion location, duodenal papilla morphology, the circular filling defect in the distal end of the common bile duct, the distance from obstructed pancreatic duct to duodenal papilla, the angle of the pancreaticobiliary duct, and lesion signal characteristics on plain T2WI fat suppressant images) and the 5 classification of MRI images, the AUC of the 5 classifications of MRI images was 0.932(95%CI:0.867-0.997), which was higher than that of any of the significant univariate indexes (all P<0.05). In addition, the 5 classifications of MRI images have the same high diagnostic power as the logistic regression analysis model(P>0.05). Conclusions: The 5 classification of MRI images can improve the accuracy of differential diagnosis of IPAC and PPAC before surgery, and the diagnostic efficiency is better than any single factor meaningful index and comparable to that of the logistic regression analysis model.

Bioinformatic and expression analysis of the OMT gene family in Pyrus bretschneideri cv. Dangshan Su.

With high nutritional value in its fruits, Dangshan Su pear has been widely cultivated in China. The stone cell content in fruits is a key factor affecting fruit quality in pear, and the formation of stone cells has been associated with lignin biosynthesis. O-Methyltransferase (OMT) is a key enzyme involved in lignin metabolism within the phenylpropanoid pathway. Here, we screened 26 OMT genes from the Pyrus bretschneideri cv. Dangshan Su genome using the DNATOOLs software. To characterize the OMT gene family in pear, gene structure, chromosomal localization, and conserved motifs of PbOMTs were analyzed. PbOMTs were divided into two categories, type I (designated PbCCOMTs) and type II (designated PbCOMTs), indicating the differentiation of function during evolution. Based on the analysis of multiple sequence alignment, cis-element prediction, and phylogenetic relationships, two candidate genes, PbCCOMT1 and PbCCOMT3, were selected for the analysis of temporal and spatial gene expression in pear. The promoter regions of both PbCCOMT1 and PbCCOMT3 contain regulatory motifs for lignin synthesis. Moreover, the two genes show high similarity and close phylogenetic relationships with CCOMTs in other species. Expression analysis showed that transcript levels of two PbCCOMTs were positively associated with the contents of both stone cells and lignin during the development of pear fruit. These results suggest that PbCCOMT1 and PbCCOMT3 are closely associated with lignin biosynthesis. These findings will help clarify the function of PbOMTs in lignin metabolism and to elucidate the mechanisms underlying stone cell formation in pear.

Clinical significance of signal pattern of high-risk human papillomavirus using a novel fluorescence in situ hybridization assay in cervical cytology.

The present study aimed to evaluate a novel fluorescence in situ hybridization (FISH) assay for detecting the high-risk human papillomavirus (HR-HPV) DNA and signal pattern in cervical cytology specimens and for identifying cervical intraepithelial neoplasia (CIN) lesions. One hundred and ninety-six liquid-based cytology specimens with CIN were recruited. The signal pattern (punctate, mixed punctate and diffuse, and diffuse) detected by FISH was compared with E6 mRNA and correlated with histological classification. FISH and E6-type specific polymerase chain reaction (PCR) had fair to good agreement for detecting HPV DNA across all grades of CIN (kappa coefficient, 0.37-0.73). Among 44 samples of negative FISH and positive E6 type-specific PCR in HPV 16, 18, 31, 33, 52 and 58, 82% (36/44) of E6 mRNA were not detected, in contrast to 41% (48/118) of positive FISH and positive E6 type-specific PCR (p <0.0001). Among HR-HPV DNA positive cases tested by the FISH assay, the specificity of predicting CIN3 using the punctuate pattern is higher than that using E6 mRNA (96.3% vs. 44.8%). The punctate pattern was 0% in patients with

Disturbances of amino acids from temporal lobe synaptosomes in human complex partial epilepsy.

We have studied the levels of neuroactive amino acids in synaptosomes (P2 fraction) isolated from brain tissue of ten patients with medically intractable epilepsy who were undergoing temporal lobectomy. First, lateral temporal tissue (nonfocal) was removed followed by medial temporal tissue (focal). A synaptosomal fraction (P2) was immediately prepared from each tissue and analyzed for free amino acid concentrations. Statistically significant reductions were seen in glutamine and GABA concentrations in focal tissue compared to nonfocal tissue. The ratio of excitatory amino acids (aspartate and glutamate) to inhibitory amino acids (taurine and GABA) was significantly higher in focal tissue compared to nonfocal. The glutamine/glutamate ratio was significantly reduced. These data support the hypothesis that alterations in the balance between excitatory and inhibitory amino acids may be involved in the expression of epilepsy.

Effects of taurine and guanidinoethane sulfonate on toxicity of the pyrrolizidine alkaloid monocrotaline.

Monocrotaline (MONO), a pyrrolizidine alkaloid, causes pulmonary arterial hypertension and right ventricular hypertrophy due to hepatic metabolism to the alkylating pyrrole dehydromonocrotaline. Taurine a sulfonic amino acid, is hepato- and cardioprotective in a variety of conditions. We have examined the effects of taurine and its amidino analog, guanidinoethane sulfonate (GES), in rats injected i.p. with MONO (65 mg/kg). Taurine and GES were given as 1% solutions in drinking water beginning 14 days before administration of MONO and continuing for 14 days therafter, when the rats were killed. The MONO group had right ventricular hypertrophy and pulmonary hyperplasia. Compared with control, no significant changes in the right ventricle/left ventricle weight ratio, or the right ventricle/body weight ratio occurred in rats also given taurine of GES. Lung weights in these two groups were higher than in the control group, but below that of the MONO-alone group. The lethality of MONO over 14 days was decreased by taurine (LD50 for MONO alone 80 mg/kg; for MONO + taurine 121 mg/kg). Rats given only MONO had lower hepatic concentrations of GSH and cysteine (Cys), and higher activities of microsomal GSH transferase activity were no different from control. Gamma-Glutamylcysteine (Glu-Cys) synthetase and gamma-glutamyl transpeptidase activities were elevated. In MONO-injected rats given GES, hepatic GSH levels were higher and Cys levels were lower than in either the MONO alone or MONO + taurine groups. Gamma-Glu-Cys synthetase activity was depressed. Microsomal GSH transferase, GSH peroxidase and gamma-glutamyl transpeptidase activities were elevated. Livers of MONO-injected animals showed higher levels of serine (reversed by both taurine and GES) and glycine (Gly; reversed by GES) and lower levels of glutamine. Compared with control rats, the following changes occurred in serum amino acids: MONO alone: increased aspartate, taurine and lysine; taurine-supplemented: increased taurine, methionine (Met) and lysine, and decreased Gly; GES-supplemented: decreased asparagine, serine, Gly, arginine, taurine, and valine. Compared with the MONO-alone group, the taurine-supplemented group had higher glutamate (Glu), Met and alanine, and the GES-supplemented group higher alanine and lower serine, Gly, arginine and valine. We conclude that taurine protects against MONO-induced lethality and right ventricular hypertrophy. GES also protects against right ventricular hypertrophy. However, these agents act by different mechanisms, taurine preventing many of the biochemical changes induced by MONO, with GES inducing additional changes.

Effects of monocrotaline, a pyrrolizidine alkaloid, on glutathione metabolism in the rat.

Monocrotaline (MONO), a pyrrolizidine alkaloid, causes veno-occlusive disease of the liver, pulmonary arterial hypertension, and right ventricular hypertrophy. Toxicity is due to the hepatic formation of a pyrolic metabolite that can be detoxified by conjugation with glutathione (GSH). We have shown that the GSH content of the liver affects the quantity of the pyrrolic metabolite that is released from the liver. We have now examined whether MONO, in turn, affects GSH metabolism. Twenty-four hours after administration of MONO to rats (65 mg/kg, i.p.), the highest concentration of bound pyrrolic metabolites was found in the liver, followed by the lung and kidney. Heart and brain contained lower concentrations of these metabolites. Significantly higher levels of GSH were found in liver and lungs of MONO-treated rats than in saline-injected control animals. In the liver, activities of the following enzymes were elevated: gamma-glutamylcysteine synthetase, GSH synthetase, gamma-glutamyl transpeptidase, dipeptidase, and microsomal GSH transferase. The same changes were seen in the lung. In the heart, gamma-glutamyl transpeptidase activity was decreased markedly, and cytosolic GSH transferase activity was elevated. In the kidney, the activities of GSH synthetase, gamma-glutamyl transpeptidase, and cytosolic GSH transferase were increased. Our results establish a mutual interaction of MONO and sulfur metabolism. It appears that an early metabolic action of MONO is to modify sulfur amino acid metabolism, diverting cysteine metabolism from oxidation to taurine towards synthesis of GSH.

Physicochemical and metabolic basis for the differing neurotoxicity of the pyrrolizidine alkaloids, trichodesmine and monocrotaline.

Monocrotaline and trichodesmine are structurally closely related pyrrolizidine alkaloids (PAs) exhibiting different extrahepatic toxicities, trichodesmine being neurotoxic (LD(50) 57 mu mol/kg) and monocrotaline pneumotoxic (LD(50) 335 mu mol/kg). We have compared certain physicochemical properties and metabolic activities of these two PAs in order to understand the quantitative and qualitative differences in toxicity. Both PAs were metabolized in the isolated, perfused rat liver to highly reactive pyrrolic dehydroalkaloids that appear to be responsible for the toxicity of PAs. More dehydrotrichodesmine (468 nmol/g liver) than dehydromonocrotaline (116 nmol/g liver) was released from liver into perfusate on perfusion for 1 hr with 0.5 mM of the parent PA. Dehydrotrichodesmine had a significantly longer aqueous half-life (5.4 sec) than that of dehydromonocrotaline (3.4 sec). In vivo, significantly higher levels of bound pyrroles were found in the brain 18 hr after injection of trichodesmine (25 mg/kg; i.p.) than were seen following either an equal dose (25 mg/kg; i.p.) or an equitoxic dose (90 mg/kg; i.p.) of monocrotaline. Trichodesmine had a higher partition coefficient than monocrotaline for both chloroform and heptane, indicating its greater lipophilicity. The pK(a) of trichodesmine (7.07) was only slightly higher than that of monocrotaline (pK(a¿ 6.83), suggesting that a difference in degree of ionization was not a major factor affecting the relative ability of the dehydroalkaloids to cross the blood-brain barrier. We conclude that the greater lethality and neurotoxicity of trichodesmine compared to monocrotaline is due to two structural characteristics: (i) steric hindrance at position 14 of dehydrotrichodesmine results in greater resistance to hydrolysis, allowing more to be released from the liver and to be delivered to the brain; (ii) the larger isopropyl substituent at position 14 of dehydrotrichodesmine renders the molecule more lipophilic, leading to greater penetration of the brain.

Fluorimetric determination of monobromobimane and o-phthalaldehyde adducts of gamma-glutamylcysteine and glutathione: application to assay of gamma-glutamylcysteinyl synthetase activity and glutathione concentration in liver.

The reversed-phase HPLC separation of fluorescent o-phthalaldehyde (OPA) derivatives has been applied to the assay of hepatic gamma-glutamylcysteine and glutathione (GSH) levels and the enzymes producing these peptides. The method has been compared to the assay using monobromobimane (MB) as the derivatizing agent. The OPA method has the advantage of faster derivatization, the lack of need to adjust the pH, isocratic separation and selectivity for GSH and gamma-glutamylcysteine. The MB method requires pH adjustment following derivatization and gradient elution chromatography. MB is also non-selective, yielding fluorescent derivatives of all biological thiols and more interfering peaks on the chromatogram. MB-based analyses are also approximately sixty times more expensive per sample. MB yields fluorescent degradation products on exposure to light. OPA adducts are stable for up to ten days when stored at -20 degrees C. OPA detection is sensitive to 12.5 pmol in the sample, at a signal-to-noise ratio of 2.5. The two methods correlate well. Hepatic gamma-glutamylcysteine synthetase in the same liver preparation was found to be 4.85 +/- 0.47 nmol min-1 mg-1 protein by the OPA method and 4.42 +/- 0.52 nmol min-1 mg-1 protein by the MB method. GSH concentrations were found to be 90.4 +/- 6.5 nmol/mg protein for the OPA method and 92.5 +/- 3.4 for the MB method.

The comparative metabolism of the four pyrrolizidine alkaloids, seneciphylline, retrorsine, monocrotaline, and trichodesmine in the isolated, perfused rat liver.

Despite their similarity in structure, pyrrolizidine alkaloids (PAs) vary in their LD50s and in the organs in which toxicity is expressed. We have examined whether there are differences in the metabolism of certain PAs that are associated with these quantitative and qualitative differences in toxicity. Isolated rat livers were perfused with one of four PAs (seneciphylline, retrorsine, monocrotaline, and trichodesmine) at 0.5 mM for 1 hr, and the pyrrolic metabolites determined that were released into perfusate and bile or bound in the liver. The proportion of the PA removed by the liver varied from 93% for retrorsine to 55% for trichodesmine. However, trichodesmine-perfused livers released the greatest amount of the dehydroalkaloid into the perfusate. These reactive pyrrolic metabolites appear to be largely responsible for the toxicity of PAs. Over the course of a 1-hr perfusion, dehydroalkaloid release varied fourfold among the PAs examined. Seneciphylline and retrorsine significantly increased bile flow. Highest concentrations of PAs in bile were achieved at 30-40 min perfusion. Conversion of dehydroalkaloid to the conjugate 7-glutathionyl-6,7-dihydro-1-hydroxymethyl-5H-pyrrolizine (GSDHP) is a detoxification reaction. GSDHP release into bile varied from 80 nmol/g liver for trichodesmine to 880 nmol/g for retrorsine. Release of the less toxic hydrolytic product of dehydroalkaloids, 6,7-dihydro-7-hydroxy-1-hydroxymethyl-5H-pyrrolizine, was also determined. Bound pyrroles in liver are probably an indication of heptatoxicity. At the end of perfusion these varied from 55 nmol/g for monocrotaline to 195 nmol/g for retrorsine. The chemical form of the bound pyrroles is a 7-thioether conjugate of 6,7-dihydro-1-hydroxymethyl-5H-pyrrolizine. No 7,9-dithio conjugate was detected, indicating that only monoalkylation has been found. These differences in metabolic pattern reflect differences in reactivity of the initially formed dehydroalkaloid and can account for the toxicological differences between the parent PAs.

The effect of the pyrrolizidine alkaloids, monocrotaline and trichodesmine, on tissue pyrrole binding and glutathione metabolism in the rat.

One day after in vivo administration of equitoxic doses of the hepatotoxic and pneumotoxic pyrrolizidine alkaloid, monocrotaline (65 mg/kg, i. p.) or the related hepatotoxic and neurotoxic alkaloid trichodesmine (15 mg/kg, i. p.) hepatic GSH levels are increased by more than 50%. These doses of alkaloids represent 60% of the LD50 values. Accompanying these changes in GSH levels is an increase in the overall rate of GSH synthesis in supernatants of alkaloid-exposed livers. The ability of the rat to metabolize the two alkaloids was shown by the appearance of tissuebound pyrrolic metabolites of pyrrolizidines in various organs. The levels of these metabolites appear to correlate with organ toxicity. For the hepatic and pneumotoxic alkaloid, monocrotaline, higher levels are found in liver (17 nmoles/g tissue) and lung (10 nmoles/g) than for trichodesmine (7 nmoles/g and 8 nmoles/g, respectively). For the neurotoxic alkaloid, trichodesmine, higher levels are found in brain (3.8 nmoles/g tissue) than for monocrotaline (1.7 nmoles/g tissue).