A giant solitary fibrous tumor of the abdominal pelvic cavity: A case report and literature review.

RATIONALE: Solitary fibrous tumor (SFT) is a rare mesenchymal tumor, especially the giant one from the abdominal pelvic cavity. We report on a rare case of a giant SFT of the abdominal pelvic cavity to review the existing literature in detail to improve the diagnosis and treatment of SFT. PATIENT CONCERNS: The patient is a 52-year-old female who presented with 2 weeks of abdominal distension. Abdominal magnetic resonance imaging showed a giant mass (>20 cm) in the abdominal pelvic cavity, considered a mesenchymal tumor. She denies a history of tumor disease. DIAGNOSES: A whole abdomen bulge and a mass of about 18 cm × 10 cm on the right side and middle side were found in the physical examination after admission. Abdominal enhanced computed tomography revealed a giant cystic-solid mass located on the middle and right side of the abdominal pelvic cavity, measuring approximately 20.4 cm × 11.7 cm, with multiple cystic changes and necrosis and compression of adjacent organs and tissues, and marked inhomogeneous enhancement. INTERVENTIONS: The patient underwent an open abdominal pelvic cavity giant tumor operation to achieve a radical resection, and did not undergo chemotherapy or radiotherapy. OUTCOMES: The patient underwent open complete resection of a giant abdominal pelvic tumor with no complications and was diagnosed as SFT according to the pathology, immunohistochemistry showed that the tumor tested positive for CD34(+), STAT-6(+), and Ki-67 (10%). Abdominal computed tomography scans were performed 6 months after resection, and no signs of recurrence or metastasis were found. LESSONS: The clinical symptoms and imaging features of giant abdominal pelvic cavity SFT are not typical. Preoperative diagnosis is difficult and has the potential for malignancy. Based on the results of the current study, there is no standard treatment strategy around the world and the therapeutic effect of radiation therapy and chemotherapy is relatively limited. Thus, complete surgical resection and close clinical follow-up are advocated.

Giant mucinous liposarcoma of the abdominal cavity: A case report.

RATIONALE: Mucinous liposarcoma myxoid liposarcoma is a malignant mucoid soft tissue tumor derived from undifferentiated stromal cells in perivascular, subbody cavity and intermuscular space, and composed of cells at different stages of differentiation from preadipocytes to mature cells. In rare cases, it may change from lipoma malignancy. The main manifestations is painless mass, relatively slow growth, the course can last decades, the prevalence of liposarcoma in the population is 14% to 18%, mainly in adults, male prevalence is higher than women, but not significant. The main good hair part is the thigh, have mucinous sex, high differentiation type, dedifferentiation type, polymorphic type. Clinical diagnosis is difficult, and there are no obvious symptoms in the early stage, so the diagnosis should be combined with B ultrasound, MRI, CT, and other auxiliary examinations. The gold standard is pathological examination. In December 2023, our department admitted a patient with a mucinous abdominal mass. The report is as follows. PATIENT CONCERNS: Does liposarcoma metastasize? Is any chemotherapy required after surgery? Will it ever relapse in the future? What is the survival period after surgery? DIAGNOSIS: Mucinous liposarcoma. INTERVENTIONS: Surgical resection of the sarcoma. RESULTS: The nodule sample was 33 * 28 * 13 cm, with complete capsule, gray and yellow sections, fine texture, soft, gray, red, grayish, and yellow mucoid nodules in some areas, and the maximum diameter of the nodules was 21cm. Immunohistochemistry was: CD34 (+), CDK 4 (+), CK (-), Desmin (weak +), Ki67 (index 5%), MDM 2 (-), p16 (weak +), S-100P (+), Vimentin (+), BCL-2 (+). He was also sent to the Department of Pathology of Peking Union Medical College Hospital for consultation with Professor Lu Zhaohui, whose consultation opinion was in line with myxoliposarcoma. CONCLUSION: Retroperitoneal liposarcoma is a common retroperitoneal tumor, but it is relatively rare in clinical practice; the overall morbidity is low, mainly manifested as abdominal pain and abdominal distension, abdominal distension, and a long course of disease; it is not sensitive to radiotherapy and chemotherapy, and should be closely follow up by CT examination to understand the recurrence and metastasis.

Validation of continuous intraabdominal pressure measurement: feasibility and accuracy assessment using a capsular device in in-vivo studies.

BACKGROUND: Monitoring Intraabdominal Pressure (IAP) is essential in critical care, as elevated IAP can lead to severe complications, including Abdominal Compartment Syndrome (ACS). Advances in technology, such as digital capsules, have opened new avenues for measuring IAP non-invasively. This study assesses the feasibility and effectiveness of using a capsular device for IAP measurement in an animal model. METHOD: In our controlled experiment, we anesthetized pigs and simulated elevated IAP conditions by infusing CO2 into the peritoneal cavity. We compared IAP measurements obtained from three different methods: an intravesical catheter (IAPivp), a capsular device (IAPdot), and a direct peritoneal catheter (IAPdir). The data from these methods were analyzed to evaluate agreement and accuracy. RESULTS: The capsular sensor (IAPdot) provided continuous and accurate detection of IAP over 144 h, with a total of 53,065,487 measurement triplets recorded. The correlation coefficient (R²) between IAPdot and IAPdir was excellent at 0.9241, demonstrating high agreement. Similarly, IAPivp and IAPdir showed strong correlation with an R² of 0.9168. CONCLUSION: The use of capsular sensors for continuous and accurate assessment of IAP marks a significant advancement in the field of critical care monitoring. The high correlation between measurements from different locations and methods underscores the potential of capsular devices to transform clinical practices by providing reliable, non-invasive IAP monitoring.

[Vacuum-assisted laparostomy for advanced peritonitisis]. / Rol' vakuum-assistirovannoi laparostomy v lechenii rasprostranennogo peritonita.

OBJECTIVE: To evaluate the efficacy of negative pressure therapy in patients with peritonitis. MATERIAL AND METHODS: The study included 127 patients with advanced secondary peritonitis between 2019 and 2022. All patients were divided into 2 groups. All ones underwent staged sanitation of the abdominal cavity. In the first group (n=76), re-laparotomies were accompanied by skin suture only and passive abdominal drainage. The second group included patients (n=51) with open abdominal cavity strategy and negative pressure therapy (vacuum-assisted laparostomy). We analyzed the number of surgeries, postoperative complications, duration of hospital-stay and mortality. RESULTS: In the second group, there were significantly lower morbidity, mean number of surgeries and hospital-stay. In addition, incidence of fascial closure of abdominal cavity was higher and mortality rate was lower in the same group. CONCLUSION: Vacuum-assisted laparostomy in patients with advanced peritonitis can reduce the number of secondary purulent complications and mortality, as well as increase the incidence of fascial closure of abdominal cavity. This approach reduces the number of surgical interventions and duration of in-hospital treatment.

Pedunculated focal nodular hyperplasia of the liver in a healthy child born following in vitro fertilization: a case report and review of the literature.

BACKGROUND: Focal nodular hyperplasia is a common nonmalignant liver mass. This nonvascular lesion is an uncommon mass in children, especially those with no predisposing factors, namely radiation, chemotherapy, and hematopoietic stem cell therapy. Exophytic growth of the lesion further than the liver margins is not common and can complicate the diagnosis of the lesion. This report observes a focal nodular hyperplasia as a pedunculated lesion in a healthy child. CASE PRESENTATION: We describe a 9-year-old healthy Persian child who was born following in vitro fertilization complaining of abdominal pain lasting for months and palpitation. Employing ultrasound and computed tomography, a mass was detected in the right upper quadrant compatible with focal nodular hyperplasia imaging features. The child underwent surgery and the mass was resected. CONCLUSION: Diagnosing focal nodular hyperplasia, especially pedunculated form can be challenging, although magnetic resonance imaging with scintigraphy is nearly 100% sensitive and specific. Thus, a biopsy may be needed to rule out malignancies in some cases. Deterministic treatment in patients with suspicious mass, remarkable growth of lesion in serial examination, and persistent symptoms, such as pain, is resection, which can be done open or laparoscopic.

Effect of intra-abdominal boric acid in the experimental adhesion model.

BACKGROUND: The continuous advancement in medical and surgical techniques has led to a rise in the frequency of abdominal operations, subsequently increasing the incidence of intra-abdominal adhesions. Over 90% of laparotomies result in postoperative intra-abdominal adhesions. This study investigates the effect of a 5% boric acid solution on the development of intra-abdominal adhesions in rats, using an adhesion model. METHODS: This study was conducted with two groups: a control group, in which the adhesion model was applied without any treatment, and a boric acid group, which was treated with a 5% boric acid solution. Each group comprised 16 rats. On the 14th postoperative day, the rats were sacrificed, re-explored, and the developed adhesions were evaluated both macroscopically and microscopically. The data from macroscopic and microscopic scoring were analyzed using the Mann-Whitney U test in the IBM Statistical Package for the Social Sciences (SPSS) Statistics 24 program. A p-value of less than 0.05 was considered statistically significant. This research was supported by the Manisa Celal Bayar University Scientific Research Projects Commission. RESULTS: A statistically significant difference was observed between the boric acid-treated group and the control group, with the boric acid group showing a significant decrease in adhesion development both macroscopically and microscopically (p<0.05). CONCLUSION: In the future, boron could play a significant role in reducing and preventing intra-abdominal adhesions after surgery. This investigation could pave the way for further research into the mechanism by which boric acid prevents the development of intra-abdominal adhesions. Moreover, it is imperative to explore the potential side effects of intra-abdominal boron application at the optimum concentration of the solution.

Halichoeres sanchezi n. sp., a new wrasse from the Revillagigedo Archipelago of Mexico, tropical eastern Pacific Ocean (Teleostei: Labridae).

A new labrid fish species, Halichoeres sanchezi n. sp., is described from eight specimens collected in the Revillagigedo Archipelago in the tropical eastern Pacific Ocean, off the coast of Mexico. The new species belongs to the Halichoeres melanotis species complex that is found throughout the region, differing by 2.4% in the mtDNA cytochrome c oxidase I sequence from its nearest relative, H. melanotis from Panama, and 2.9% from Halichoeres salmofasciatus from Cocos Island, off Costa Rica. The complex is distinguished from others in the region by having a black spot on the opercular flap and a prominent black area on the caudal fin of males. The juveniles and initial phase of the new species closely resemble those of H. salmofasciatus and Halichoeres malpelo from Malpelo Island of Colombia, differing in having an oblong black spot with a yellow dorsal margin on the mid-dorsal fin of initial-phase adults as well as on juveniles. In contrast, the terminal-phase male color pattern is distinct from other relatives, being vermilion to orangish brown with dark scale outlines, a white patch on the upper abdomen, and a prominent black band covering the posterior caudal peduncle and base of the caudal fin. The new species adds to the list of endemic fish species for the isolated archipelago and is an interesting case of island endemism in the region. The discovery was made during the joint 2022 collecting expedition to the archipelago, which featured a pioneering collaborative approach to an inventory of an island ichthyofauna, specifically including expert underwater photographers systematically documenting specimens in situ, before hand-collection, and then photographed fresh, tissue-sampled, and subsequently vouchered in museum collections.

The association of TLR4 gene polymorphisms with the severity of peritonitis in acute inflammatory diseases of the abdominal cavity organs.

OBJECTIVE: Aim: To determine the role of TLR4 gene polymorphisms as risk factors for peritonitis severity in patients undergoing surgery for acute inflammatory diseases of the abdominal cavity. PATIENTS AND METHODS: Materials and Methods: The study included 139 patients who were operated on for acute abdominal diseases (acute appendicitis and cholecystitis, perforated gastric or duodenal ulcer, etc.). Depending on the number of points on the modified APACHE II scale, patients were divided into two groups: Group 1 - 1-3 points (63 patients, 45.3%) and Group 2 - 4 or more points (76 patients, 54.7%). Polymorphisms rs1927911, rs2149356 and rs4986790 were determined by polymerase chain reaction. RESULTS: Results: The rs1927911 polymorphism of the TLR4 gene was protective for the development of peritonitis (according to the allelic model, OR 0.48; 95% CI 0.27-0.84; p=0.015). Regression analysis revealed a reduced (p=0.015) risk of severe peritonitis in rs1927911 A/A or G/A genotype carriers (OR 0.42; 95% CI 0.21-0.84) compared with G/G genotype carriers. There was no effect on the severity of peritonitis of TLR4 polymorphisms rs2149356 and rs4986790. There was a tendency to increase the frequency of the mutant G rs4986790 allele in patients with severe peritonitis (χ2=2.17; p<0.001). The analysis of the association of TLR4 gene polymorphisms with the phenotype of patients showed that carriers of mutant homozygotes and heterozygotes in the presence of severe peritonitis were older, had a tendency to coagulopathy, higher leukocytosis and leukocyte clotting rate. CONCLUSION: Conclusions: Thus, the importance of TLR in the development of severe peritonitis was confirmed and the protective role of the rs1927911 promoter polymorphism was established.

Conservative versus Surgical Treatment of Pneumatosis Intestinalis: Experience from a Multidisciplinary Center.

BACKGROUND Pneumatosis intestinalis (PI) is an uncommon condition that is not specific to any particular disease. Currently, there is no specific clinical guideline for treating and diagnosing PI. Furthermore, there are numerous causes of PI, which makes it difficult for clinicians - internal medicine physicians as well as surgeons - to take a clinical approach to diagnosis and treatment. CASE REPORT We present 3 clinical scenarios with PI. In the first patient there was a solitary image of PI, which was treated successfully with parenteral nutrition and intravenous antibiotics, and he was discharged after 5 days. The other 2 cases, which involve gas in the hepatic portal vein (HPVG), were handled in 2 distinct ways: surgically and conservatively. One needed diagnostic laparoscopy with necrotic segmentectomy and was discharged from the hospital on postoperative day 16. The last patient, received resuscitation treatment due to severe comorbidities and inability to tolerate surgery. After 3 days, abdominal CT scan revealed no signs of remaining PI. However, the patient was terminally discharged after 7 weeks of treatment due to septic shock caused by sacrococcygeal ulcer and urinary tract infection. By drawing comparisons among these 3 scenarios, we aim to highlight certain indicators for conservative treatment success. CONCLUSIONS PI with HPVG is a sign of severe prognosis, which often requires surgical intervention. However, the decision to manage conservatively or surgically depends on the patient's condition and other criteria such as peritonitis, free fluid in the abdominal cavity, and the presence of shock. Physicians should also weigh the benefits and risks of surgical intervention in critically ill patients.

Safety of postdischarge extended venous thromboembolism prophylaxis after hepatopancreatobiliary surgery.

BACKGROUND: The risk of venous thromboembolism (VTE) after hepatopancreatobiliary (HPB) surgery is high. Extended postdischarge prophylaxis in this patient population has been controversial. This study aimed to examine the safety of postdischarge extended VTE prophylaxis in patients at high risk of VTE events after HPB surgery. METHODS: Adult patients risk stratified as very high risk of VTE who underwent HPB operations between 2014 and 2020 at a quaternary care center were included. Patients were matched 1:2 extended VTE prophylaxis to the control group (patients who did not receive extended prophylaxis). Analyses compared the proportions of adverse bleeding events between groups. RESULTS: A total of 307 patients were included: 103 in the extended prophylaxis group and 204 in the matched control group. Demographics were similar between groups. More patients in the extended VTE prophylaxis group had a history of VTE (9% vs 3%; P = .045). There was no difference in bleeding events between the extended VTE prophylaxis and the control group (6% vs 2%; P = .091). Of the 6 patients with bleeding events in the VTE prophylaxis group, 5 had gastrointestinal (GI) bleeding, and 1 had hemarthrosis. Of the 4 patients with bleeding events in the control group, 1 had intra-abdominal bleeding, 2 had GI bleeding, and 1 had intra-abdominal and GI bleeding. CONCLUSION: Patients discharged with extended VTE prophylaxis after HPB surgery did not experience more adverse bleeding events compared with a matched control group. Routine postdischarge extended VTE prophylaxis is safe in patients at high risk of postoperative VTE after HPB surgery.

Involvement of CX3CR1+ cells appearing in the abdominal cavity in the immunosuppressive environment immediately after gastric cancer surgery.

BACKGROUND: Gastric cancer is primarily treated by surgery; however, little is known about the changes in the intraperitoneal immune environment and the prognostic impact of surgery. Surgical stress and cancer-associated inflammation cause immune cells to mobilize into the abdominal cavity via numerous cytokines. One such cytokine, CX3CR1, has various immune-related functions that remain to be fully explained. We characterized the intraperitoneal immune environment by investigating CX3CR1+ cells in intraperitoneal lavage fluid during gastric cancer surgery. METHODS: Lavage fluid samples were obtained from a total of 41 patients who underwent gastrectomy. The relative expression of various genes was analyzed using quantitative real-time PCR. The association of each gene expression with clinicopathological features and surgical outcomes was examined. The fraction of CX3CR1+ cells was analyzed by flow cytometry. Cytokine profiles in lavage fluid samples were investigated using a cytometric beads array. RESULTS: CX3CR1high patients exhibited higher levels of perioperative inflammation in blood tests and more recurrences than CX3CR1low patients. CX3CR1high patients tended to exhibit higher pathological T and N stage than CX3CR1low patients. CX3CR1 was primarily expressed on myeloid-derived suppressor cells and tumor-associated macrophages. In particular, polymorphonuclear myeloid-derived suppressor cells were associated with perioperative inflammation, pathological N, and recurrences. These immunosuppressive cells were associated with a trend toward unfavorable prognosis. Moreover, CX3CR1 expression was correlated with programmed death-1 expression. CONCLUSIONS: Our results suggest that CX3CR1+ cells are associated with an acute inflammatory response, tumor-promotion, and recurrence. CX3CR1 expression could be taken advantage of as a beneficial therapeutic target for improving immunosuppressive state in the future. In addition, analysis of intra-abdominal CX3CR1+ cells could be useful for characterizing the immune environment after gastric cancer surgery.

[Evaluation of safety of early enteral nutrition in patients with severe intra-abdominal infection and intestinal fistulas].

Objective: To evaluate the safety of early enteral nutrition (EEN) support in patients with severe intra-abdominal infection and intestinal fistulas. Methods: This was a retrospective cohort study. We collected relevant clinical data of 204 patients with severe intra-abdominal infection and intestinal fistulas who had been managed in the No. 1 Department of General Surgery, Shanghai Ninth People's Hospital, Shanghai Jiaotong University between 1 January 2017 and 1 January 2020. The patients were allocated to EEN or delayed enteral nutrition (DEN) groups depending on whether enteral nutrition had been instituted within 48 hours of admission to the intensive care unit. The primary outcome was 180-day mortality. Other outcomes included rates of intraperitoneal hemorrhage, septic shock, open abdominal cavity, bloodstream infection, mechanical ventilation, and continuous renal replacement therapy. Risk factors for mortality were analyzed by logistic regression. Results: There were no significant differences in hematological data or other baseline characteristics between the two groups at the time of admission to the intensive care unit (all P>0.05). However, septic shock (31.2% [15/48] vs. 15.4% [24/156], χ2=4.99, P=0.025), continuous renal replacement therapy (27.1% [13/48] versus 9.0% [14/156], χ2=8.96, P=0.003), and 180-day mortality (31.2% [15/48] vs. 7.7% [12/156], χ2=15.75, P<0.001) were significantly more frequent in the EEN than the DEN group (all P<0.05). Multivariate regression analysis showed that older age (OR=1.082, 95%CI:1.027-1.139,P=0.003), worse Acute Physiology and Chronic Health Evaluation (APACHE) II scores (OR=1.189, 95%CI: 1.037-1.363, P=0.013), higher C-reactive protein (OR=1.013, 95%CI:1.004-1.023, P=0.007) and EEN (OR=8.844, 95%CI:1.809- 43.240, P=0.007) were independent risk factors for death in patients with severe intra-abdominal infection and intestinal fistulas. Conclusion: EEN may lead to adverse events and increase mortality in patients with both enterocutaneous fistulas and severe abdominal infection. EEN should be implemented with caution in such patients.

[Diagnostic value of identifying location and amount of free gas in the abdominal cavity by multidetector computed tomography in patients with acute gastrointestinal perforation].

Objective: To evaluate the relationships between the location and extent of diffusion of free intraperitoneal air by multi-slice spiral CT (MSCT) and between the location and size of acute gastrointestinal perforation. Methods: This was a descriptive case series. We examined abdominal CT images of 33 patients who were treated for intraoperatively confirmed gastrointestinal perforation (excluding appendiceal perforation) in the Department of General Surgery, Nanfang Hospital between January and September 2022. We identified five locations of intraperitoneal air: the subphrenic space, hepatic portal space, mid-abdominal wall, mesenteric space, and pelvic cavity. We allocated the 33 patients to an upper gastrointestinal perforation (n=23) and lower gastrointestinal perforation group (n=10) base on intraoperative findings and analyzed the relationships between the locations of free gas and of gastrointestinal perforation. Additionally, we established two models for analyzing the extent of diffusion of free gas in the abdominal cavity and constructed receiver operating characteristic (ROC) curves to analyze the relationships between the two models and the size of the gastrointestinal perforation. Results: In the upper gastrointestinal perforation group, free gas was located around the hepatic portal area in 91.3% (21/23) of patients: this is a significantly greater proportion than that found in the lower gastrointestinal perforation group (5/10) (P=0.016). In contrast, free gas was located in the mesenteric interspace in 8/10 patients in the lower gastrointestinal perforation group; this is a significantly greater proportion than was found in the upper gastrointestinal perforation group (8.7%, 2/23) (P<0.010). The sensitivity of diagnosis of upper gastrointestinal perforation base on the presence of hepatic portal free gas was 84.8% and the specificity 71.4%. Further, the sensitivity of diagnosis of lower gastrointestinal perforation base on the presence of mesenteric interspace free gas was 80.0% and the specificity 91.3%. The rates of presence of free gas in the subdiaphragmatic area, mid-abdominal wall, and pelvic cavity did not differ significantly between the two groups (all P>0.05). Receiver operating characteristic curves showed that when free gas was present in four or more of the studied locations in the abdominal cavity, the optimal cutoff for perforation diameter was 2 cm, the corresponding sensitivity 66.7%, and the specificity 100%, suggesting that abdominal free gas diffuses extensively when the diameter of the perforation is >2 cm. Another model revealed that when free gas is present in three or more of the studied locations, the optimal cutoff for perforation diameter is 1 cm, corresponding to a sensitivity of 91.7% and specificity of 76.2%; suggesting that free gas is relatively confined in the abdominal cavity when the diameter of the perforation is <1 cm. Conclusion: Identifying which of five locations in the abdominal cavity contains free intraperitoneal air by examining MSCT images can be used to assist in the diagnosis of the location and size of acute gastrointestinal perforations.

Transumbilical Endoscopic Resection of Intra-abdominal Mesenchymal Tumor.

Gastrointestinal stromal tumors (GISTs) typically occur in the stomach and proximal small intestine but can also be found in any other part of the digestive tract, including the abdominal cavity, albeit rarely. In the present case, the tumor was resected endoscopically through the anterior gastric wall. Computed tomography (CT) scan and gastroscopy of a 60-year-old woman revealed submucosal lesions in the gastric body. The possibility of a stromal tumor was considered more likely. The endoscopic surgery was performed under endotracheal anesthesia. After a solution had been injected at the lesion site in the stomach, the entire gastric wall was dissected to expose the tumor. As the lesion was in the abdominal cavity and its base was attached to the abdominal wall, it was accessed using a sterilized PCF colonoscope. A sodium chloride injection was administered at the base. The tumor was then peeled along its boundaries using the hooking and excision knife combined with the precutting knife. Subsequently, the tumor was pulled into the stomach through the incision made in the stomach and then extracted externally through the upper digestive tract using the ERCP spiral mesh basket. After confirming the absence of bleeding at the incision site, the endoscope was returned to the stomach, and the stomach opening was closed using purse-string sutures. The patient recovered satisfactorily following the surgery and was discharged on day 4. Histological examination revealed a low-risk stromal tumor (spindle cell type, <5 mitosis/50 high-power fields [HPF]). Immunohistochemistry revealed positive staining for CD34 and CD117, negative staining for SMA, positive staining for DOG1, and negative staining for S100. Additionally, the expression of ki67 was 3%.

Effects of nano-cerium dioxide on intestinal microflora in rats by oral subchronic exposure.

OBJECTIVE: To investigate intestinal toxicity in rats and the effects of Nano-cerium dioxide on intestinal flora in rats after oral sub-chronic exposure. METHOD: Forty healthy male SD rats were randomly divided into four groups: a control group (deionized water) and three groups treated with different doses of Nano-ceria (e.g., 20 mg/kg, 100 mg/kg, and 500 mg/kg), with 10 rats in each group. The rats were given intragastric administrations (every other day) for 90 days. After the last intragastric administration, fresh fecal samples were collected by pressing the abdomen, and the animals were sacrificed. Jejunum, ileum and cecum tissues were retained for pathological analysis by Hematoxylin-eosin staining. The stool samples of rats were sequenced by the Illumina NovaSeq sequencing platform, and the sequencing results were further analyzed by QIIME2 software. RESULTS: The histopathology results show that compared with the control group, in the middle- and high-dose groups, epithelial tissue was shed, lamina propria glandular structures were damaged or disappeared, and large numbers of inflammatory cells were distributed in the mucosa. The intestinal flora results show that there were no significant differences in the α-/ß-diversities in each Nano-ceria-treated group compared with the control group (P>0.05). Compared with the control group, the intestinal pathogenic bacteria, Mucispirillum and Streptococcus increased significantly after Nano-cerium dioxide ingestion, while Weissella decreased. The abundances of Akkermansia in all Nano-ceria-treated groups were higher than those in the control group, but the abundances decreased with increasing dose. MetagenomesSeq analysis show that, compared with the control group, the abundances of S24-7, Lactobacillus and Clostridiales in all experimental groups significantly decreased. CONCLUSIONS: The sub-chronic toxicity of Nano-cerium dioxide to rats can affect the structure and abundance of intestinal microflora, long-term exposure to high doses (>100 mg/kg) causes enteritis, but there was no significant difference in the diversity of gut microbiota. Therefore, we infer that the enteritis in rats may be associated with the relative ratios of the pathogenic bacteria and intestinal probiotics, and increased of the intestinal pathogenic bacteria can disrupted intestinal homeostasis.

Quantifying effectiveness and best practices for bumblebee identification from photographs.

Understanding pollinator networks requires species level data on pollinators. New photographic approaches to identification provide avenues to data collection that reduce impacts on declining bumblebee species, but limited research has addressed their accuracy. Using blind identification of 1418 photographed bees, of which 561 had paired specimens, we assessed identification and agreement across 20 bumblebee species netted in Montana, North Dakota, and South Dakota by people with minimal training. An expert identified 92.4% of bees from photographs, whereas 98.2% of bees were identified from specimens. Photograph identifiability decreased for bees that were wet or matted; bees without clear pictures of the abdomen, side of thorax, or top of thorax; bees photographed with a tablet, and for species with more color morphs. Across paired specimens, the identification matched for 95.1% of bees. When combined with a second opinion of specimens without matching identifications, data suggested a similar misidentification rate (2.7% for photographs and 2.5% specimens). We suggest approaches to maximize accuracy, including development of rulesets for collection of a subset of specimens based on difficulty of identification and to address cryptic variation, and focused training on identification that highlights detection of species of concern and species frequently confused in a study area.