Pathological changes at early stage of multiple organ injury in a rat model of severe acute pancreatitis

BACKGROUND: Severe acute pancreatitis (SAP) is a commonly seen acute abdominal syndrome characterized by sudden onset, rapid progression and high mortality rate. The damage in peripheral organs may be more severe than that in the pancreas, and can even lead to multiple organ dysfunction. It is critical to recognize early pathological changes in multiple organs. This study aimed to assess the early pathological features of damaged organs in a rat model of SAP. METHODS: Thirty clean grade healthy male Sprague-Dawley rats weighing 250-300 g were randomly divided into a model control group (n=15) and a sham-operated group (n=15). The SAP rat model was induced by sodium taurocholate. Samples of blood and from multiple organs were collected 3 hours after operation. We assessed the levels of IL-6, TNF-alpha, PLA2, NO, ET-1, MDA, amylases and endotoxin in blood and observed the early pathological changes in multiple damaged organs. RESULTS: Levels of IL-6, TNF-alpha, PLA2, NO, ET-1 and MDA in serum and of amylase and endotoxin in plasma of the model control group rats were significantly higher than those of the sham-operated group (P<0.01). Different degrees of pathological change were observed in multiple damaged organs. CONCLUSION: Multiple organ injury may occur at the early stage of SAP in rats.

Pathological changes in multiple organs of rats with severe acute pancreatitis treated by baicalin and octreotide

BACKGROUND: Severe acute pancreatitis (SAP) features fatal pathogenetic conditions and high mortality rate. The study of SAP complicated with multiple organ injuries is of important significance. In this study, we explored the protective effect of baicalin on multiple organs of SAP rats and compared it with that of octreotide through light and electron microscopic observations of the pathological changes. METHODS: The improved Aho method was used to prepare SAP rat models. These rats were then randomly divided into a sham-operated group (n=45), a model control group (n=45), baicalin-treated group (n=45) and octreotide-treated group (n=45). Based on the difference in time points after operation, these groups were subdivided into 3, 6 and 12 hour subgroups (n=15). At the corresponding time point after operation, the mortality rate of rats was recorded, and then the rats were humanely killed to take samples of multiple organs that were subsequently examined for pathological changes under light and electron microscopy. RESULTS: At 12 hours after operation, the mortality rate of rats in the baicalin- and octreotide-treated groups was lower than that in the model control group (P < 0.05). Compared to the model control group, the pathological changes and pathological scores in the baicalin- and octreotide-treated groups were mitigated and relieved to varying degrees. The pathological changes under electron microscopy were also improved. CONCLUSIONS: Both baicalin and octreotide show good protective effects on multiple organs of SAP rats. Baicalin as a new drug has good prospects in the treatment of SAP.

A progressive compression model of thoracic spinal cord injury in mice： function assessment and pathological changes in spinal cord

Non-traumatic injury accounts for approximately half of clinical spinal cord injury, including chronic spinal cord compression. However, previous rodent spinal cord compression models are mainly designed for rats, few are available for mice. Our aim is to develop a thoracic progressive compression mice model of spinal cord injury. In this study, adult wild-type C57BL/6 mice were divided into two groups： in the surgery group, a screw was inserted at T9 lamina to compress the spinal cord, and the compression was increased by turning it further into the canal（0.2 mm） post-surgery every 2 weeks up to 8 weeks. In the control group, a hole was drilled into the lamina without inserting a screw. The results showed that Basso Mouse Scale scores were lower and gait worsened. In addition, the degree of hindlimb dysfunction in mice was consistent with the degree of spinal cord compression. The number of motor neurons in the anterior horn of the spinal cord was reduced in all groups of mice, whereas astrocytes and microglia were gradually activated and proliferated. In conclusion, this progressive compression of thoracic spinal cord injury in mice is a preferable model for chronic progressive spinal cord compression injury.

Pathological Changes in the Sinoatrial Node Tissues of Rats Caused by Pulsed Microwave Exposure

To observe microwave induced dynamic pathological changes in the sinus nodes, wistar rats were exposed to 0, 5, 10, 50 mW/cm^2 microwave. In 10 and 50 mW/cm^2 groups, disorganized sinoatrial node cells, cell swelling, cytoplasmic condensation, nuclear pyknosis, and anachromasis, swollen, and empty mitochondria, and blurred and focally dissolved myofibrils could be detected from 1 to 28 d, while reduced parenchymal cells, increased collagen fibers, and extracellular matrix remodeling of interstitial cells were observed from 6 to 12 months. In conclusion, 10 and 50 mW/cm^2 microwave could cause structural damages in the sinoatrial node and extracellular matrix remodeling in rats.

CORRELATION OF THE MAGNETIC MOTOR EVOKED POTENTIAL TECHNIQUE WITH PATHOLOGICAL CHANGES ASSOCIATED WITH SPINAL CORD INJURY IN ADULT CATS

To determine whether the pathological changes caused by injury to the spinal cord can be correlated with values obtained by the Magnetic Motor Evoked Potential (MEPs) technique, we studied spinal cords from 41 adult cats who were divided into 4 groups. The groups ranged from normal cats whose spinal cords were not compressed, to slightly, moderately and severely injured. MEPs were recorded before compression and in 30 minutes, 6 hours, 1 week, 2 week and 4 week after the compression unit was installed. Pathological changes with increased pressure were seen in blood vessels, nerve cells and fibers, Nissl substance and the central canal. A reversal of pathological changes was observed in slight or moderate injury during the 4 weeks of the experiment. Extensive injury, however, caused irreversible changes in the nerve cells with loss of motor function. The latency of MEPs at 30 minutes and 6 hours in the slightly injured group was 037 and 038 times greater than the baseline and returned to normal levels in 4 weeks. In the moderately injured group, the latency was increased 077 and 081 times and in the severely injured 132 and 136 times over the baseline. Recovery in the second group was partial and not at all in the severely injured. Thus, there appears to be good correlation between observed pathological changes, motor functions and MEPs.

Ultrastructural Pathologic Observation on the Gut-Associated Lymphoid Tissues of Sacculus Rotundus of Rabbits Infected with Rabbit Haemorrhagic Disease Virus

Ultrastructural pathological changes in the gut-associated lymphoid tissues of sacculus rotundus (SR) of rabbits infected with rabbit haemorrhagic disease virus (RHDV) were first observed. There were numerous holes at the luminal and basement membrane surfaces of the dome epithelium (DE), consistently accompanied by necrosis of lymphocytes and M-cells, and pronounced depletion of lymphocytes in the domes and follicles, decrease of DE complex with formation of pseudomembranous structure on the surface of the dome epithelium. A specific finding in lymphocytes and macrophages was that severe destruction detraction of the membrane of rough endoplasmic reticulum(RER) was accompanied by conspicious increase of solitary, ribo-some-like particles in the cytoplasm, with appearances of intranuclear particles and intranuclear inclusions. It was found that there were many round and dense virion-like particles, with 26 nm in diameter, in the nuclei and cytoplasm of lymphoctes, plasma cells, macrophages and fibroblasts, or in degenerated cells and cellular debris. At the same time, another round virion-like particles about 34 nm in diameter were also seen in the cytoplasm of some cells and interstitium. The results indicated that the appearances of the ribosome-like particles, virion-like particles and inclusion bodies were related to the replication and assembly of RHDV. The present observations suggested that DE of sacculus rotundus could be a open pathway and a transporting route for the entry of antigens into hosts. While the antigen is profoundly deleterious, DE may be as a closed portal or a barrier preventing the foreign antigenic materials from invading.

Dual-ratiometric magnetic resonance tunable nanoprobe with acidic-microenvironment-responsive property to enhance the visualization of early tumor pathological changes

The development of microenvironment-responsive nanoprobes has shown great promise for use in magnetic resonance imaging(MRI),with the advantage of significantly improved specificity and good biocompatibility.However,the clinical application of responsive probes is hampered by a lack of biological sensitivity for early molecular diagnostics and visualizing microenvionment of metabolism reprogramming in tumor progression.Here,we report on a dual-ratiometric magnetic resonance tunable(DMRT)nanoprobe designed by crosslinking different ratios of transferrin chelating gadolinium and superparamagnetic nanoparticles,complexed to a pH responsive biocompatible polymer.This dually activatable nanoprobe enables pH-dependent tumor microenvironment visualization,providing exceptional quantitative pathophysiological information in vitro and in vivo.When used in combination with dual-contrast enhancement triple subtraction imaging technique(DETSI),this smart nanoprobe guarantees the diagnosis of early-stage diseases.We envisage that this novel integrated nanoplatform will provide a new paradigm for the clinical translation of robust DMRT nanoprobes for early disease detection and staging,as well as microenvironment visualization and disease progression monitoring.

Primary hepatic solitary fibrous tumor with histologically benign and malignant areas

Extrapleural solitary fibrous tumor （SFT） is an uncommon mesenchymal neoplasm, presenting most commonly in the intrathoracic sites but which has been reported at nu- merous extrathoracic locations. The majority of intra-thoracic SFTs are benign, but 10%-15% behave aggressively. We report a case of primary hepatic SFT with histologically benign and ma- lignant areas. A 65-year-old man underwent an abdominal CT scan following a cerebrovascular accident, which demonstrated a sharply demarcated large liver mass with a heterogenous enhancing area and occupying most of the left lobe of the liver. Histological examination following a hemihepatectomy showed an SFT with morphological patterns ranging from benign to malignant areas, including pleomorphism, increased cellularity, herringbone pattern, necrosis and a raised mitotic count. On review of the literature, only an occasional case report with malignant areas in a hepatic SFT was identified. This case highlights that SFT should be included in the differential diagnosis of a hepatic spindle cell lesion, and that on rare occasions, malignant areas can occur in this already uncommon neoplasm.

Effect of L-cysteine on remote organ injury in rats with severe acute pancreatitis induced by bile-pancreatic duct obstruction

BACKGROUND: Remote organ failure occurs in cases of acute pancreatitis (AP); however, the reports on AP induced by pancreatic duct obstruction are rare. In this study we determined the effect of L-cysteine on pancreaticobiliary inflammation and remote organ damage in rats after pancreaticobiliary duct ligation (PBDL). METHODS: AP was induced by PBDL in rats with 5/0 silk Sixty rats were randomly divided into 4 groups. Groups A and B were sham-operated groups that received injections of saline or L-cysteine (10 mg/kg) intraperitoneally (15 rats in each group). Groups C and D were PBDL groups that received injections of saline or L-cysteine (10 mg/kg) intraperitoneally (15 rats in each group). The tissue samples of the pancreas and remote organs such as the lung, liver, intestine and kidney were subsequently examined for pathological changes under a light microscope. The samples were also stored for the determination of malondialdehyde and glutathione levels. Blood urea nitrogen (BUN), plasma amylase, ALT and AST levels were determined spectrophotometrically using an automated analyzer. Also, we evaluated the effect of L-cysteine on remote organ injury in rats with AP induced by retrograde infusion of 3.5% sodium taurocholate (NaTc) into the bile-pancreatic duct. RESULTS: Varying degrees of injury in the pancreas, lung, liver intestine and kidney were observed in the rats 24 hours after PBDL. The severity of injury to the lung, liver and intestine was attenuated, while injury status was not changed significantly in the pancreas and kidney after L-cysteine treatment. Oxidativestress was also affected by L-cysteine in PBDL-treated rats. The concentration of tissue malondialdehyde decreased in the pancreas and remote organs of PBDL and L-cysteine administrated rats, and the concentration of glutathione increased more significantly than that of the model control group. However, L-cysteine administration reduced the severity of injury in remote organs but not in the pancreas in rats with NaTc-induced AP. CONCLUSION: L-cysteine treatment attenuated multiple organ damage at an early stage of AP in rats and modulated the oxidant/antioxidant imbalance.

Effect of organophosphorus pesticide pollution on soil animals

This paper studied the change in soil animal community in contaminated and irrigated area by organophosphorus pesticide waste water and its mechanism was discussed. The results showed that the species and quantities of soil animals decreased with organophosphorus pesticide pollution degree increasing. The species of soil animals decreased with average and rare population mainly decreasing, while the amount change was associated with that of the dominant population of Acarina, Collembola and Nematoda. Toxicity experiment demonstrated that the respiration intensity of soil animal was restrained obviously by pesticide pollution. After observation of SEM, the effect of pesticide pollution on the earthworm (\%Pheretima robusta)\% stomach intestinal mucosa damage has been observed, which showed the pesticide contamination may damage the earthworms bodies. Ulcerous focus and perforation on stomach mucosa were usually seen. The stomach microvilli appeared atrophic and disordered especially in the bodies of these earthworms growing in seriously polluted soil, bad atrophic phenomena were seen not only on the stomach mucosa microvilli but also on the cilia of the intestinal mucosa which appeared swollen as a spheroid. Under TEM, RER and Golgi compound dilatation, chondrisome swell and ridge disappearance were observed on cells of stomach epithelium mucosa of \%P.robusta\% collected from heavy polluted area. By calculation, the safety concentration of earthworm in methamidophos pesticide is 0\^2517 ml/L.

Therapeutic effects of smecta or smectite powder on rats with paraquat toxication

BACKGROUND:The plasma concentration of paraquat is closely related to the prognosis of patients with paraquat toxication,and the most common cause of death from paraquat poisoning is multiple organ failure(MOF).This study aimed to evaluate therapeutic effect of smecta on the plasma concentrations of paraquat and multi-organ injury induced by paraquat intoxication in rats.METHODS:A total of 76 healthy adult SD rats were randomly divided into group A(control group,/7=6),group B(poisoned group,n=30) and group C(smecta-treated group,n=30).Rats in groups B and C were treated intragastrically with PQ at 50 mg/kg,and rats in group A was treated intragastrically with saline(1 ml_).Rats in group C were given intragastrically smecta at 400 mg/kg 10 minutes after administration of PQ,while rats in other two groups were treated intragastrically with 1ml_ saline at the same time.Live rats in groups B and C were sacrificed at 2,6,24,48,72 hours after administration of PQ for the determination of paraquat plasma concentrations and for HE staining of the lung,stomach and jejunum.The rats were executed at the end of trial by the same way in group A.RESULTS:The plasma concentration of paraquat(ng/mL) ranged from 440.314±49.776 to4320.6150±413.947.Distinctive pathological changes were seen in the lung,stomach and jejunum in group B.Lung injuries deteriorated gradually,edema,leukocyte infiltration,pneumorrhagia,incrassated septa and lung consolidation were observed.Abruption of mucosa,hyperemic gastric mucosa and leukocyte infiltration were obvious in the stomach.The hemorrhage of jejunum mucosa,the abruption of villus,the gland damage with the addition of inflammatory cell infiltration were found.Compared to group B,the plasma concentration of paraquat reduced(P<0.01) and the pathological changes mentioned above were obviously alleviated in group C(P<0.05,P<0.01).CONCLUSION:Smecta reduced the plasma concentration of paraquat and alleviated pathologic injury of rats with PQ poisoning.

Evaluation of the toxicity of fluorine in Antarctic krill on soft tissues of Wistar rats

Antarctic krill are a potential food source for humans and animals, but krill are known to contain high levels of fluorine （F）. In this study, we investigated the toxicity of F in Antarctic krill using Wistar rats. There were three experimental groups： The control group were fed a basal diet, the krill treatment group were fed the same basal diet mixed with krill powder （150 mg＇kg-~ F）, and the sodium fluoride （NaF） treatment group were fed the basal diet with added NaF （150 mg.kg1 F）. General toxicity indicators including body weight and food intake were measured during the experiment. After three months the rats were dissected and tissue samples were collected from the liver, kidney, spleen, brain, and testis. Morphological changes in the cells of these tissues were assessed using HE staining. There were no significant differences in the body weight, the food intake, or the viscera coefficients among the three groups. In both treatment groups some pathological changes were observed in all soft tissue samples except the testis, although there were fewer and less severe pathological changes in the krill treatment group than in the NaF treatment group. The results showed that the toxicity of F in Antarctic krill was lower than for an equivalent amount of F in NaF, but it was still toxic to rats consuming large quantities of krill. The findings of this study highlight the need for further investigation into potential F toxicity if krill is to be used for human consumption.

Study of viruses co-infecting white clover(Trifolium repens)in China

Globally, white clover（Trifolium repens L.） is commonly infected by plant viruses. It is grown at gardens, roadsides, and public areas as ornamental plants in northern China. Some leaves present disease symptoms that are similar to those of virus infection. However, to our knowledge, no records are available from China regarding white clover（Trifolium repens L.） virus co-infection. To determine the viral species that infect white clover in China, plant samples with virus disease symptoms were collected and virion morphology and ultrastructure morphology of co-infected plants were observed by electron microscopy; viruses were detected by enzyme linked immunosorbent assay（ELISA） and reverse transcription PCR（RT-PCR）. Virus co-infection was studied by double antibody sandwich enzyme linked immunosorbent assay（DAS-ELISA） and real-time fluorescence quantitative PCR（RT-q PCR） after rub-inoculation of virus-free white clover planted in a growth chamber（25°C） with a photoperiod of 16 h, using single or several purified virions. Results showed that there were six types of symptoms, including those of shrinking mosaic, shrinking and macular mosaic, severe mottle mosaic, yellow macular mosaic, shrinkage chlorisis, and ring plaque and ring stria. The incidence rates for each symptom were 20.93, 1.48, 16.85, 59.07, 1.30, and 0.37%, respectively, based on the field investigation. Two types of viral pathogens were identified as Alfalfa mosaic virus（AMV） and White clover mosaic virus（WCMV）. In mesophyll cells, virus particles with bacilliform virions formed aggregates and linear virions were bundle shaped. The detection rate of AMV was 100% in white clover samples by DAS-ELISA and RT-PCR detection, whereas that of WCMV was 83.33%. The co-infection rate was 83.33%. The relative contents of AMV and WCMV were significantly increased by 5.897-and 3.515-fold upon co-infection, when compared to that with single virus infection. We observed larger starch particles and fewer or collapsed chloroplast grana in co-infected plants; in addition, vacuoles were twisted and smaller, compared to those of healthy plants. To our knowledge, this is the first report of co-infection by AMV and WCMV in white clover, which has caused severe mosaicism and ultrastructure lesions in co-infected plants in China.

Dysbiosis of gut microbiome affecting small intestine morphology and immune balance:a rhesus macaque model

There is a growing appreciation for the specific health benefits conferred by commensal microbiota on their hosts.Clinical microbiota analysis and animal studies in germ-free or antibiotic-treated mice have been crucial for improving our understanding of the role of the microbiome on the host mucosal surface;however,studies on the mechanisms involved in microbiome-host interactions remain limited to small animal models.Here,we demonstrated that rhesus monkeys under short-term broad-spectrum antibiotic treatment could be used as a model to study the gut mucosal host-microbiome niche and immune balance with steady health status.Results showed that the diversity and community structure of the gut commensal bacteria in rhesus monkeys were both disrupted after antibiotic treatment.Furthermore,the 16S rDNA amplicon sequencing results indicated that Escherichia-Shigella were predominant in stool samples 9 d of treatment,and the abundances of bacterial functional genes and predicted KEGG pathways were significantly changed.In addition to inducing aberrant morphology of small intestinal villi,the depletion of gut commensal bacteria led to increased proportions of CD3+T,CD4+T,and CD16+NK cells in peripheral blood mononuclear cells(PBMCs),but decreased numbers of Treg and CD20+B cells.The transcriptome of PBMCs from antibiotic-treated monkeys showed that the immune balance was affected by modulation of the expression of many functional genes,including IL-13,VCAM1,and LGR4.

Interpretation of Diagnosis and Treatment Protocol for Novel Coronavirus Pneumonia(Trial Version 7)

On March 3,2020,the National Health Commission and the National Administration of Traditional Chinese Medicine of China jointly promulgated the Notice on Printing and Distributing the Diagnosis and Treatment Protocol for Novel Coronavirus Pneumonia(Trial Version 7).The content has been revised and supplemented on the basis of the Version 6,including etiological characteristics and pathological changes in lung,heart,kidney,spleen,liver,gallbladder,esophagus,stomach and intestinal mucosal epithelium.In particular,the diagnosis and treatment methods of traditional Chinese medicine are supplemented.It provides an evidence-based diagnosis and treatment protocol for the treatment and recovery of suspected and confirmed cases of novel coronavirus pneumonia with traditional Chinese medicine and Western medicine.

Structural and physiological changes of the human body upon SARS-CoV-2 infection

Since December 2019,the novel coronavirus(severe acute respiratory syndrome coronavirus 2(SARS-CoV-2))has spread to many countries around the world,developing into a global pandemic with increasing numbers of deaths reported worldwide.To data,although some vaccines have been developed,there are no ideal drugs to treat novel coronavirus pneumonia(coronavirus disease 2019(COVID-19)).By examining the structure of the coronavirus and briefly describing its possible pathogenesis based on recent autopsy reports conducted by various teams worldwide,this review analyzes the possible structural and functional changes of the human body upon infection with SARS-CoV-2.We observed that the most prominent pathological changes in COVID-19 patients are diffuse alveolar damage(DAD)of the lungs and microthrombus formation,resulting in an imbalance of the ventilation/perfusion ratio and respiratory failure.Although direct evidence of viral infection can also be found in other organs and tissues,the viral load is relatively small.The conclusion that the injuries of the extrapulmonary organs are directly caused by the virus needs further investigation.