Inhibiting Multidrug Resistance with Transferrin-Targeted Polymersomes through Optimization of Ligand Density

Transferrin-conjugated polymersomes, transferrin-biotin/avidin/biotin-Pluronic F127-poly(lactic acid) (Tf-F127-PLA), were successfully prepared through a biotin-avidin bridging technique to study their ability to inhibit multidrug resistance of cancer cells. Hydrophilic doxorubicin (DOX) was selected as the model drug to be loaded into Tf-F127-PLA polymersomes. DOX loaded in Tf-F127-PLA polymersomes was released fast initially, followed by a slow release. The effect of the transferrin ligand density of Tf-F127-PLA/DOX polymersomes on their targeting properties was studied by both cytotoxicity and cellular uptake assays against A549 lung cancer cells. It was shown that Tf-F127-PLA/DOX polymersomes had better targeting ability than nontargeted drug-loaded polymersomes. Furthermore, Tf-F127-PLA/DOX polymersomes with 2% Tf molar content have more effective antitumor activity and a higher cellular uptake than those with 4 and 5% Tf molar content. 2% Tf-F127-PLA/DOX polymersomes also exhibited better anticancer ability in multidrug resistant cancer cells A549/ADR than nontargeted PLA-F127-PLA/DOX polymersomes. It was further proved that the endocytosis of polymersomes by A549/ADR cells was an energy-dependent endocytosis process, which was related to clathrin, macrocytosis, and caveolin. Also, the endocytosis of Tf-F127-PLA/DOX polymersomes was proven to be mediated by the transferrin receptor.

Synergistic antitumor effect of folate-targeted Pluronic™ F-127/poly(lactic acid) polymersomes for codelivery of doxorubicin and paclitaxel

Aim: Folate-targeted Pluronic™ F-127/poly(lactic acid) (FA-F127-PLA) polymersomes were used as codelivery carriers of doxorubicin hydrochloride (DOX) and paclitaxel (PTX) to achieve a targeted synergistic antitumor effect. Materials & methods: The cytotoxicity of PTX/DOX polymersomes against OVCAR-3 cells was determined by methyl thiazolyl tetrazolium assay. The cellular uptake of PTX/DOX polymersomes was examined by HPLC and micro-bicinchoninic acid techniques. Results: The polymersomes showed a bilayer core-shell structure with negative charge and good dispersion. PTX₁/DOX₅ polymersomes with a mass ratio of PTX to DOX of 1:5 showed the best synergistic effect and the highest cellular uptake. Conclusion: FA-F127-PLA polymersomes have the great promise for codelivery of multiple chemotherapeutics to achieve a targeted antitumor synergistic effect.

Co-Delivery of paclitaxel and doxorubicin in folate-Targeted pluronic/ploy (D,L-lactide-b-glycolide) polymersomes

Drugs with different solubility can be selectively embedded into polymersomes with the hydrophilic core and hydrophobic bilayer. Novel folate-targeted Pluronic/poly (D,L-lactide-b-glycolide) polymersomes were constructed and used for the co-delivery of paclitaxel (PTX) and doxorubicin (DOX) to improve their inhibitory effect over cancer cells. The particle size of blank polymersomes was mainly distributed below 125 nm. The release of PTX and DOX from polymersomes showed an initial burst release followed by a sustained and slow release. The in vitro cytotoxicity data showed that the targeted co-loaded polymersomes (PTX&DOX FA-Ps) exhibited better inhibitory effect than single-loaded polymersomes and free drugs did. Furthermore, PTX&DOX FA-Ps showed the synergistic therapeutic effect over OVCAR-3 cancer cells. The cellular uptake results also showed that folate modified polymersomes had excellent targeting performance. Therefore, the folate-targeted Pluronic/poly (D,L-lactide-b-glycolide) polymersomes have potential application value as novel drug carriers to co-deliver PTX and DOX.

Transferrin/folate dual-targeting Pluronic F127/poly(lactic acid) polymersomes for effective anticancer drug delivery

A novel dual-targeting Pluronic/poly(lactic acid) polymersome containing transferrin and folic acid ligands (Tf/FA-F127-PLA) has been designed to study its application in the targeted drug delivery system. Both biotin and folic acid conjugated Biotin/FA-F127-PLA polymersomes (Ps) were prepared as the precursor. The dual-targeting behaviors of Tf/FA-F127-PLA over C6 glioma cells were then fulfilled through connecting the precursor with biotinylated transferrin by using a three-step biotin-avidin technique. Paclitaxel (PTX) was loaded successfully into Biotin/FA-F127-PLA and showed a burst release followed by a slow-release process in vitro. It was also obtained that Tf/FA-F127-PLA had higher cytotoxicity and cellular uptake amount than non-targeted and single-targeted Ps did. These results could be because more PTX-loaded Tf/FA-F127-PLA Ps entered C6 cells through both FA-folate receptor (FR) and Tf-transferrin receptor (TfR) specific affinity and thus possessed the better anti-tumor ability. It was further proved that the uptake of Ps by C6 cells was through the endocytosis related to clathrin, caveolae, lysosome, etc. Furthermore, it was demonstrated that the uptake of dual-targeting Tf/FA-F127-PLA Ps by C6 cells was related to the endocytosis mediated by both FR and TfR. These findings indicated that dual-targeting Tf/FA-F127-PLA Ps could be a potential carrier in targeted drug delivery systems.

Study on the Influencing Factors of Hypoglycemic Effect of Folate Targeted Polymersomes Encapsulating Insulin

PURPOSE

To study the effects of the density of folic acid (FA) on the hypoglycemic ability of FA-targeted polymersomes as oral insulin carriers. Also to study the change of the hypoglycemic effect of FA-targeted mixed polymersomes added with various mass ratio of d-α-tocopherol polyethylene glycol 1000 succinate (TPGS).

METHODS

The FA-targeted polymersomes with different FA molar contents were prepared. The in vitro insulin release experiments in different media for FA-targeted polymersomes with various FA contents were studied. Their quantitative cellular uptake in Caco-2 cells was examined. The in vivo hypoglycemic activity of FA-targeted polymersomes was also studied with diabetic rats. The polymersomes with the optimal FA molar content was chosen to prepare mixed polymersomes with various TPGS contents.

RESULTS

Among insulin-loaded FA-targeted polymersomes with four different FA molar contents, insulin-loaded polymersomes with 10% FA molar content (insulin-loaded 10%FA-Ps) showed the hightest cellular uptake and the best hypoglycemic response. In addition, the insulin-loaded FA-Ps/TPGS5:1 mixed polymersomes exhibited higher cellular uptake and better hypoglycemic response than the other two insulin-loaded mixed polymersomes adding TPGS did.

CONCLUSIONS

FA-Ps/TPGS5:1 could be a promising formulation for the oral administration of insulin.

[Clinical experience of minimal invasive coronary surgery-coronary artery bypass grafting: a series of 244 cases]

Objective: To examine the safety and efficacy of minimally invasive coronary surgery-coronary artery bypass grafting (MICS-CABG). Methods: From the first case in November 2015 to November 2019, a total of 244 cases of MICS-CABG were performed in Department of Cardiovascular Surgery, Peking University Third Hospital. There were 197 males and 47 females, aging (62.3±8.7)years (range: 36 to 88 years). The operations were performed via the 5(th) intercostal space of left thoracic lateral incision (length: 4 to 5 cm extended for 8 to 10 cm), and were performed under off-pump, with the help of the chest wall suspension device and cardiac fixator. The proximal anastomosis on ascending aorta and the distal anastomosis of left anterior descending branch, circumflex branch and right coronary system were completed according to procedure. In all 244 cases, the proportion of 2 grafts was 53.7% (131 cases), 3 grafts was 36.1% (88 cases), 4 grafts was 9.8% (24 cases) and 5 grafts was 0.4% (1 case). The average of grafts was 2.6±0.7 (range: 2 to 5). The proportion of hybrid was 14.3% (35 cases), sequential bypass procedure was 43.0% (105 cases) and multiple artery grafts was 25.4% (62 cases). The perioperative complications of the patients were collected, the patency rate of the grafts was evaluated by coronary angiography or CT within 7 days after the operation, and main adverse cardiovascular and cerebrovascular events (MACCE) were followed up. The survival curve was drawn by Kaplan-Meier method, and the 1-year MACCE rate was calculated by survival analysis. Results: All cases had no transition to thoracotomy and cardiopulmonary bypass procedure, and no cases needed intra aortic balloon pumping and extracorporeal membrane oxygenation during the operation.There were 2 cases of poor incision healing, and reoperation was performed in 10 cases (6 cases of postoperative bleeding, 2 cases of incision debridement, and 2 cases of grafts problems). The rate of MACCE in 30 days was 2.6% (10 cases), which contained 3 cases of death (2 cases of grafts occlusion, 1 case of serious hemorrhage after thoracic puncture drainage), 3 cases of stroke and 5 cases of non-fatal myocardial infarction. By the re-examination of angiography in 7 days after operation, the overall patency of the grafts was 96.1%, and the patency of the left anterior descending was 98.6%. Kaplan-Meier survival analysis was conducted for 235 patients (96.3%) with 1 to 36 months follow-up results, and the 1-year MACCE rate was 5.6% (95%CI: 4.2% to 7.0%) . There was no significant difference among the incidences of MACCE at each stage of learning curve. Surgeon could reduce the operation time and complete more anastomosis with the accumulation of experience after the early 30 cases. Conclusions: MICS-CABG can safely achieve completed revascularization, which has good operative effects in short and medium-long term. There is no significant risk in the early cases of learning curve.

[Early clinical outcomes of minimally invasive coronary surgery-total arterial coronary revascularization]

Objective: To summarize the early experience and clinical value of minimally invasive coronary surgery-total arterial coronary revascularization (MICS-TACR) through the left anterior small incision. Methods: Between May 2015 and June 2018, a total of 31 consecutive cases [21 males and 10 females, aged (63.2±9.3) years] in Peking University Third Hospital who were performed MICS-TACR with bilateral internal mammary artery and radial artery were enrolled. Meanwhile, 1 489 cases of conventional median sternal incision off-pump coronary artery bypass grafting (OPCABG) were matched as control group. According to exclusion criteria and matching score, 90 cases [55 males and 35 females, aged (63.8±9.5) years] were selected as the control group, and the perioperative data of the two groups were compared. All patients in MICS-TACR group underwent postoperative angiography and the graft patency was evaluated. Results: There were no statistically significant differences in baseline data between the two groups. The perioperative blood transfusion of MICS-TACR group was less than control group [0(0,0) U vs 0(0,4) U, P=0.003]. There were no statistically significant differences in operative mortality, intraoperative and postoperative intra-aortic balloon pump (IABP) and extracorporeal membrane oxygenation (ECMO) use, re-operation rate, perioperative major adverse cardiac and cerebrovascular events (MACCE), new-onset renal failure, atrial fibrillation, and multiple organ failure between the two groups. Postoperative angiography showed that there was no significant difference in the patency rate between the MICS-TACR group and control group(all P>0.05). Conclusion: Total arterial coronary revascularization can be successfully accomplished under the left anterior small incision, and the early clinical outcome is satisfied.

[Clinical significance of minimal residual disease in patients with Ph-negative precursor B-acute lymphoblastic leukemia]

目的

探讨微小残留病（MRD）水平在Ph染色体阴性的急性B淋巴细胞白血病（Ph⁻ B-ALL）中的预后意义。

方法

采用多色流式细胞术对2010年9月至2017年11月初诊的193例Ph⁻ B-ALL患者在治疗后1、3、6个月进行骨髓MRD监测，并对不同MRD水平患者的预后进行比较。

结果

中位随访22（1~92）个月，所有193例患者共行497次MRD检测。1个月时MRD水平<0.1%和≥0.1%患者的3年预期无复发生存（RFS）率分别为74.5%和29.9%，3年预期总生存（OS）率分别为67.5%和30.3%；3个月时MRD水平阴性和阳性患者的3年预期RFS率分别为75.6%和29.7%，3年预期OS率分别为71.6%和27.8%；6个月时MRD水平阴性或阳性患者的3年预期RFS率分别为74.6%和11.6%，3年预期OS率分别为74.0%和15.7%，差异均有统计学意义（P值均<0.001）。3个监测点全部达到MRD阴性标准的患者与至少1次未达到MRD阴性标准的患者比较，3年预期RFS、OS率差异均有统计学意义（80.5%对30.5%，77.1%对29.4%，P值均<0.001）。多因素分析结果显示，3个月时的MRD水平是Ph⁻ B-ALL患者独立的预后因素之一。

结论

治疗后MRD监测对Ph⁻ B-ALL的预后判断有重要意义。

Effect of the Folate Ligand Density on the Targeting Property of Folated-Conjugated Polymeric Nanoparticles

Targeted drug delivery systems have attracted increasing attention due to their ability for delivering anticancer drugs selectively to tumor cells. Folic acid (FA)-conjugated targeted block copolymers, FA-Pluronic-polycaprolactone (FA-Pluronic-PCL) are synthesized in this study. The anticancer drug paclitaxel (PTX) is loaded in FA-Pluronic-PCL nanoparticles by nanoprecipitation method. The in vitro release of PTX from FA-Pluronic-PCL nanoparticles shows slow and sustained release behaviors. The effect of FA ligand density of FA-Pluronic-PCL nanoparticles on their targeting properties is examined by both cytotoxicity and fluorescence methods. It is shown that FA-Pluronic-PCL nanoparticles indicated better targeting ability than non-targeted PCL-Pluronic-PCL nanoparticles. Furthermore, FA-F127-PCL nanoparticle with 10% FA molar content has more effective antitumor activity and higher cellular uptake than those with 50% and 91% FA molar content. These results prove that FA-F127-PCL nanoparticle with 10% FA molar content can be a better candidate as the drug carrier in targeted drug delivery systems.

Longissimus dorsi muscle transcriptomic analysis of Yunling and Chinese simmental cattle differing in intramuscular fat content and fatty acid composition

Intramuscular fat (IMF) content and fatty acid (FA) composition vary significantly across beef cattle breeds, which play an important role in taste and nutritional value. However, the molecular mechanisms underlying these phenotypic differences remain unknown. The present study compared meat quality traits between Yunling cattle and Chinese Simmental cattle. Yunling cattle showed a lower IMF content and proportion of monounsaturated fatty acids (MUFA), as well as higher proportions of saturated fatty acids (SFA), polyunsaturated fatty acids (PUFA), and short-chain fatty acids (sc-FA) in the longissimus dorsi (LD) muscle than Chinese Simmental cattle. To further identify the candidate genes and pathways responsible for these phenotypic differences, the transcriptome of LD muscle from the two breeds were measured using RNA-seq. A total of 1347 differentially expressed genes were identified. The major metabolic pathways that were differentially modulated were lipolysis and glycometabolism. Yunling cattle showed a higher expression of lipolysis genes (ALDH9A1, ACSL5, ACADM, ACAT2, ACOT2) and a lower expression of genes related to glycometabolism (PGM1, GALM, PGM1, GPI, LDHA). This research identified candidate genes and pathways for IMF content and FA composition in the LD muscle of beef cattle, which may facilitate the design of new selection strategies to improve meat quality.

[Comparison of outcomes of two minimally invasive approaches for multi-vessel coronary revascularization]

OBJECTIVE

To compare the safety and effectiveness of two minimally invasive approaches for multi-vessel coronary revascularization.

METHODS

From August 2014 to February 2017, 70 consecutive patients who underwent minimally invasive coronary artery bypass grafting in Peking University Third Hospital were randomly divided into two groups. In one group, 40 patients underwent staged-hybrid coronary revascularization (staged-HCR) treatment; in the other group, 30 patients underwent minimally invasive total arterial revascularization with bilateral internal thoracic artery (BITA). In staged -HCR group, the patients underwent minimally invasive direct coronary artery bypass grafting (MIDCAB) and percutaneous coronary intervention (PCI) procedure for treatment of multi-vessel disease. In BITA group, the patients underwent total arterial coronary artery bypass grafting with composite "Y" BITA graft. Preoperative and postoperative data of the two groups, including postoperative blood usage, mechanical ventilation time, domiciling duration in intensive care unit (ICU), major adverse cerebral and cardiovascular event (MACCE), and postoperative coronary angiography results were compared, in order to evaluate the safety and effectiveness of these surgical approaches.

RESULTS

The preoperative characteristics of 70 patients in the two groups showed no significant difference. All the patients underwent successfully, elective minimally invasive multi-vessel coronary artery bypass grafting as scheduled preoperatively. Postoperative result showed the patients in staged-HCR group took advantages in less postoperative mechanical ventilation time [Staged-HCR group (11.2±8.7) h vs. BITA group (18.3±9.1) h, P=0.013], shorter domiciling duration in ICU [Staged-HCR group (26.29±4.05) h vs. BITA group (44.74±28.75) h, P=0.022], and less total drainage [Staged-HCR group (695.57±250.46) mL vs. BITA group (1 103.26±547.44) mL, P=0.03] than the patients in the group of minimally invasive total arterial revascularization with BITA. Postoperative in hospital coronary angiography showed satisfactory graft patency rates in both groups [97.5% in Staged-HCR group vs. 97.8% in BITA group]. No MACCE occurred in both groups during hospitalization.

CONCLUSION

Staged-HCR is a feasible method for the treatment of multi-vessel revascularization involving right coronary artery. Minimally coronary revascularization with BITA is associated with superior long-term graft patency and it's recommended for patients who could not tolerate dual-antiplatelet therapy. This study shows that both minimally invasive surgical approaches are safe and effective for treatment of patients with multi-vessel coronary artery disease.

The targeting properties of folate-conjugated Pluronic F127/poly (lactic-co-glycolic) nanoparticles

Novel Folated Pluronic F127/poly (lactic-co-glycolic) (FA-F127-PLGA) and PLGA-F127-PLGA block copolymer were synthesized and nanoparticles self-assembled from these two copolymers were prepared by dialysis method. Paclitaxel (PTX) was successfully encapsulated in these two nanoparticles. According to in vitro release studies of PTX-loaded nanoparticles, after an initial burst release during the first 11h, the entrapped PTX released slowly in the following 82h. The cytotoxicity studies demonstrated that the in vitro antitumor effect of PTX could be improved by encapsulating PTX into PLGA-F127-PLGA nanoparticles. Moreover, folate-targeted FA-F127-PLGA nanoparticles were more effective than PLGA-F127-PLGA when delivering PTX in folate receptor overexpressing OVCAR-3 cells, which mainly due to the FA-receptor-meditated endocytosis. As the treatment time became longer, the targeting effects were more obvious. The targeting effect of FA-F127-PLGA nanoparticles was also investigated in vitro by measuring the cellular uptake of the nanoparticles. The results showed that FA-F127-PLGA nanoparticles were more easily to be uptaken by OVCAR-3 cells in comparison with PLGA-F127-PLGA nanoparticles. In vivo pharmacokinetic studies indicated that FA-F127-PLGA nanoparticles prolong the circulation time of PTX in plasma, and delay the blood clearance of PTX. These results indicated that Folated FA-F127-PLGA could be a potential carrier in long-term PTX delivery.

Enhanced effect of folated pluronic F87-PLA/TPGS mixed micelles on targeted delivery of paclitaxel

Targeted drug delivery systems have great potential to overcome the side effect and improve the bioavailability of conventional anticancer drugs. In order to further improve the antitumor efficacy of paclitaxel (PTX) loaded in folated Pluronic F87/poly(lactic acid) (FA-F87-PLA) micelles, D-α-tocopheryl poly(ethylene glycol) 1000 succinate (TPGS or Vitamin E TPGS) were added into FA-F87-PLA to form FA-F87-PLA/TPGS mixed micelles. The LE of PTX-loaded mixed micelles (13.5%) was highest in the mass ratio 5 to 3 of FA-F87-PLA to TPGS. The in vitro cytotoxicity assays indicated that the IC50 values for free PTX injections, PTX-loaded FA-F87-PLA micelles and PTX-loaded FA-F87-PLA/TPGS mixed micelles after 72h of incubation were 1.52, 0.42 and 0.037mg/L, respectively. The quantitative cellular uptake of coumarin 6-loaded FA-F87-PLA/TPGS and FA-F87-PLA micelles showed that the cellular uptake efficiency of mixed micelles was higher for 2 and 4h incubation, respectively. In vivo pharmacokinetic studies found that the AUC of PTX-loaded FA-F87-PLA/TPGS mixed micelles is almost 1.4 times of that of PTX-loaded FA-F87-PLA micelles. The decreased particle size and inhibition of P-glycoprotein effect induced by the addition of TPGS could result in enhancing the cellular uptake and improving the antitumor efficiency of PTX-loaded FA-F87-PLA/TPGS mixed micelles.

Novel folated Pluronic/poly(lactic acid) nanoparticles for targeted delivery of paclitaxel

In vivo prolonged circulation time and enhanced tumor resistant ability of targeted PTX-loaded FA–Pluronic–PLA nanoparticles.

A review of biodegradable polymeric systems for oral insulin delivery

Currently, repeated routine subcutaneous injections of insulin are the standard treatment for insulin-dependent diabetic patients. However, patients' poor compliance for injections often fails to achieve the stable concentration of blood glucose. As a protein drug, the oral bioavailability of insulin is low due to many physiological reasons. Several carriers, such as macromolecules and liposomes have been used to deliver drugs in vivo. In this review article, the gastrointestinal barriers of oral insulin administration are described. Strategies for increasing the bioavailability of oral insulin, such absorption enhancers, enzyme inhibitors, enteric coatings are also introduced. The potential absorption mechanisms of insulin-loaded nanoparticles across the intestinal epithelium, including intestinal lymphatic route, transcellular route and paracellular route are discussed in this review. Natural polymers, such as chitosan and its derivates, alginate derivatives, γ-PGA-based materials and starch-based nanoparticles have been exploited for oral insulin delivery; synthetic polymers, such as PLGA, PLA, PCL and PEA have also been developed for oral administration of insulin. This review focuses on recent advances in using biodegradable natural and synthetic polymers for oral insulin delivery along with their future prospects.

Synthesis and biological evaluation of substituted phenylpyrazole[4,5-b]oleanane derivatives as inhibitors of glycogen phosphorylase

A series of substituted phenylpyrazole[4,5-b]oleanane derivatives have been synthesized and biologically evaluated as inhibitors of glycogen phosphorylase (GP). The structure of phenylpyrazole moiety in compound 17 was determined by ROESY. All of the synthesized oleanane derivatives were biologically evaluated against rabbit muscle GPa. Within this series of compounds, pyrazole triterpene 7 (IC(50) = 10.8 μM) exhibited slightly more potent activity than its parent compound 1. Preliminary SAR analysis of the pyrazoleoleanane derivatives as GP inhibitors is discussed.

[Ultrastructure changes of electrical injury in rats]

OBJECTIVE

To observe ultrastructure changes of electrical injury in rats.

METHODS

An experimental model of rats suffered from the low voltage were designed. Ultrastructure changes of electrical injured tissues were observed under transmission electron microscope.

RESULTS

(1) Plasma of epithelium was concreted in the affected areas and inner membrane system was broken. (2) Hypercontraction bands were observed in skeleton muscles. (3) There was dissolved necrosis and hypercontraction bands in the myocardium. (4) Vacuoles were found in plasma of endothelium of blood vessels on electrical current path, and myelin sheath of nerve fiber were loosed.

CONCLUSION

The above mentioned ultrastructure changes could be used as assistant diagnostic index of electrocution. The mechanism of the changes were discussed.

[Studies of the correlations between DNA fingerprints and meat production traits in chickens]

This study revealed correlations between DNA fingerprints (DFPs) and slaughter traits of SR92A male x Xiaoshan female hybrids with EAV (endogenous avian retroviral element) as the probe. In the DFP patterns, the band J with molecular weight of about 4 kilobasepairs correlated significantly with alive weight, dressing weight, semi-eviscerated weight, talon weight, breast muscle weight, head weight and thigh weight. The mean alive weight, dressing weight, semi-eviscerated weight and breast muscle weight are 280 g (28.57%), 225 g (28.87%), 216 g (28.76%) and 16.71 g (54.00%) higher respectively in individuals without band J than in those with band J. With the following formula: delta W = (XJ(-) - XJ+) x N x FJ+, it was estimated that an addition of 165.2 kilograms of alive weight can be achieved in a hybrid population with size of 1,000 chickens established by selecting parents without band J.

[Forensic medical identification of sudden death due to tuberculosis of adrenal glands]

Two cases died of tuberculosis of adrenal glands were reported. The pathological findings are presented and their medico-legal significance was also discussed. In particular, emphasis is placed on the importance of histopathologic examination of the adrenal glands in the tuberculous subjects dying suddenly and in whom no obvious cause of death was found at necropsy.

[A pathological study of hemorrhage and necrosis of pancreas due to poisoned death: analysis of 22 cases]

Pathological changes of pancreas in 22 cases died of intoxication were studied and the mechanism was discussed. The results showed that: in death cases by eating of toxicants, the hemorrhage and necrosis of pancreas is extensive mainly in caput and corpus, while inhaling of carbon monoxide is focal in corpus and cauda.