[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.

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.

Effects of cholesterol uptake from high-density lipoprotein on bile secretion and 3-hydroxy-3-methylglutaryl-coenzyme A reductase activity in perfused rat liver.

Small aliquots of rat high-density lipoproteins (HDL) (388 +/- 67 nmol lipoprotein cholesterol) were labeled with [14C]cholesterol and administered as a bolus to perfused rat livers. Bile and perfusate samples were collected for 2 hours at 30-minute intervals. After perfusion, both the microsomes and lipid extracts were prepared from the livers. Lipid composition was examined in both liver and microsomes, and 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase activity was evaluated in microsomes. Basal values of bile flow, lipid composition, and enzyme activity were evaluated using livers in which perfusion was discontinued before injecting the lipoprotein. In some experiments, the effect of perfusion per se was assessed by infusing saline instead of lipoprotein. After 10 minutes of lipoprotein perfusion, 50% of cholesterol administered was taken up by the perfused liver. During infusion, transient but significant increases in both bile flow and bile steroid secretion were observed. Cholesterol administration, even if rapid, represented less than 0.4% of total liver cholesterol content. However, this was enough to significantly increase the cholesterol to phospholipid (CH/PL) molar ratio in liver microsomes and at the same time decrease HMG-CoA reductase activity. In conclusion, the main response of the perfused liver to HDL cholesterol infusion is a reduced activity of the rate-limiting enzyme in cholesterol biosynthesis, due to the shift in the microsomal CH/PL molar ratio. A small proportion of the infused cholesterol enters bile as cholesterol and bile salts.

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).

Effect of the pyrrolizidine alkaloid, monocrotaline, on bile composition of the isolated, perfused rat liver.

Monocrotaline is a hepatotoxic pyrrolizidine alkaloid, releasing high levels of metabolites into bile of isolated, perfused liver. Although perfusion of rat liver with 0.5 mM monocrotaline does not affect bile flow over a 1 hr study period, it markedly affects bile composition. Biliary release of conjugated and free GSH increases 30-fold. Marked increases are also observed in the biliary concentration of the related sulfur-containing substances, cysteine and cysteinylglycine. However, biliary release of the sulfur amino acids, taurine and methionine, is unaffected. Only two amino acids show mildly increased releases, 23% for glycine and 46% for aspartate. Release of bile acids, cholesterol and phospholipids also decrease, both in terms of mM concentration in bile and in terms of nmol secreted per g liver. Thus, exposure to monocrotaline causes disturbances in sulfur metabolism in the liver and in the composition of bile. The consequences of the digestive properties of bile and gastrointestinal toxicity remain to be established. As sulfhydryl compounds are involved in detoxification of monocrotaline metabolites, these findings indicate a mutual interaction of pyrrolizidine toxicity and sulfur metabolism. This suggests that dietary sulfur amino acid intake may influence susceptibility to pyrrolizidine poisoning.

Effect of HDL1 infusion on biliary secretion in perfused rat liver.

The effects of HDL1 lipoprotein infusion on biliary lipid secretion were studied in the in vitro model of rat perfused liver. A strong increase in bile flow was observed during and after lipoprotein infusion. This caused a significant rise in cholesterol, phospholipid and bile salt secretions. However, only the percentage of cholesterol increased with respect to the other bile lipids. The changes observed in the cholesterol/phospholipid molar ratio values of liver membrane subfractions (i.e., liver plasma membrane, mitochondria plus lysosomes and microsomes) isolated from the perfused rat liver after HDL1 administration were not significant.

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

Typhoid polymyositis.

Four patients with typhoid polymyositis, 3 of whom were members of one family, are described. There was clinical, biochemical and histological evidence of severe muscle involvement which reversed on treatment with Chloromycetin. Muscle involvement in typhoid fever is a recognised pathological entity, but a clinical syndrome involving muscle has not previously been described.

The relationship between the concentration of the pyrrolizidine alkaloid monocrotaline and the pattern of metabolites released from the isolated liver.

Hepatic metabolism of the pyrrolizidine alkaloid monocrotaline results in extrahepatic toxicity caused by the release of metabolites from the liver. We have quantified the release of pyrrolic metabolites into the perfusate and bile of isolated rat livers perfused with monocrotaline over the concentration range of 0.125-1.5 mM. Over a 1-hr perfusion period, the amount of dehydromonocrotaline released from the liver varied from 60 nmol/g liver at 0.125 mM monocrotaline to 460 nmol/g liver at 1.5 mM monocrotaline. As a percentage of total pyrrole release, this is a monotonic increase from 30 to 41%. The percentage of pyrroles released into the bile, representing mainly 7-glutathionyl-6,7-dihydro- 1-hydroxymethyl-5H-pyrrolizine (GSDHP), increased over the monocrotaline concentration range 0.125-1.0 mM, but fell sharply from 38% of total at the latter concentration to 21% of total at 1.5 mM monocrotaline. This is probably a reflection of glutathione depletion. Nonalkylating pyrrole released into the perfusate, represents largely 6,7-dihydro-7-hydroxy-1-hydroxymethyl-5H-pyrrolizine (DHP). Pyrrole released into perfusate showed an opposite pattern. The percentage of pyrroles released as DHP into the perfusate fell from 38% at 125 microM monocrotaline to 27% at 1.0 mM monocrotaline, but increased sharply to 38% at 1.5 mM monocrotaline. When calculated on a body weight basis, concentrations of monocrotaline of 500 microM result in the release from the liver of 5.3 mumol/kg of dehydromonocrotaline. This is comparable to the amount of dehydromonocrotaline, given in vivo, required for pneumotoxicity. The amounts of other pyrrolic metabolites released over a 1-hr period of perfusion are insufficient to produce pneumotoxicity in vivo. Based on the body weight of the donor rat, pyrrole release on perfusion of the isolated liver with 1,500 microM monocrotaline can be calculated as mumol/kg body weight. These amounts can then be compared to acute doses producing pneumotoxicity in vivo (given in parentheses): DHP, 13 mumol/kg body weight released (350 mumol/kg); GSDHP, 8 mumol/kg (300 mumol/kg); and dehydromonocrotaline, 14 mumol/kg (15 mumol/kg). This suggests, therefore, that dehydromonocrotaline is the pyrrolic metabolite contributing the most to the extrahepatic toxicity of monocrotaline.

Relationship between glutathione concentration and metabolism of the pyrrolizidine alkaloid, monocrotaline, in the isolated, perfused liver.

The influence of GSH concentration on metabolism of monocrotaline was examined in the isolated, perfused rat liver. Chloroethanol (0.37 mmol/kg), diethyl maleate (5.6 mmol/kg), and buthionine sulfoximine (72.9 mmol/kg) given in vivo reduced hepatic GSH from 3.7 mumol/g wet weight to 1.5, 0.6 and 0.9 mumol/g, respectively. Livers were then perfused in vitro for 1 hr with monocrotaline (0.5 mM). GSH depletion had no effect on the total release of pyrrolic metabolites of monocrotaline. Depletion, however, markedly affected the pattern of pyrrole release. Biliary release of 7-glutathionyl-6,7-dihydro-1-hydroxy-methyl-5H-pyrrolizine (GSDHP) was reduced by up to 72%. Pretreatment with diethyl maleate or buthionine sulfoximine increased the level of protein-bound pyrroles in the liver by 107 and 84%, respectively. Such pyrroles are probably responsible for liver toxicity. GSH depletion also led to a doubling of dehydromonocrotaline release into the perfusate. This metabolite is probably responsible for the extrahepatic toxicity of monocrotaline. Release into perfusate of the relatively nontoxic metabolite, 6,7-dihydro-7-hydroxy-1-hydroxymethyl-5H-pyrrolizine (DHP) was correspondingly decreased. Hepatic GSH content was increased to 4.4 mumol/g by pretreatment with oxo-4-thiazolidine carboxylate (4.76 mmol/kg). This agent increased total pyrrolic metabolites by 54%. Biliary release of GSDHP and perfusate release of dehydromonocrotaline and DHP were all increased. Thus, hepatic GSH levels regulate the metabolism of monocrotaline and dehydromonocrotaline and, consequently, the hepatic and extrahepatic toxicity of monocrotaline. GSH depletion leads to a switch from the biliary release of the midly toxic GSDHP to the perfusate release of the highly toxic dehydromonocrotaline. GSH depletion also permits more dehydromonocrotaline in the liver to become available for macromolecular alkylation. These findings suggest that nutritional intake of sulfur-containing amino acids can influence the severity of pyrrolizidine poisoning.