[Clinicopathological features of verrucous type dysplasia of esophagus].

Objective: To investigate the clinicopathological features of verrucous type (squamous) dysplasia of esophagus. Methods: The clinicopathological data of 18 verrucous type dysplasia of esophagus patients in the 989th Hospital of the Joint Logistics Support Force of the People's Liberation Army (formerly 152 Central Hospital) and Beijing Chaoyang Hospital Affiliated to Capital Medical University from 2009 to 2021 were retrospectively collected. The histomorphologic characteristics and immunophenotype were observed, and human papillomavirus (HPV) genotyping was detected by PCR-fluorescence probe. The relevant literature was reviewed. Results: The median age of the 18 patients was 68 years (range 53-76 years); there were 13 males and 5 females. There were four cases in the upper esophagus, seven in the middle esophagus and seven in the lower esophagus. The median diameter of the lesion was 18 mm (range 6-54 mm). According to the Paris Classification, 11 cases were 0-Ⅱa, one case was 0-Ⅱa+Ⅰ, five cases were 0-Ⅱb, and one case was 0-Ⅱb+Ⅰ. White light endoscopy showed that the surface of the lesion was white plaque, red areas between the plaques, and papillary surface structure could be seen. In narrow-band imaging, some mucosal areas of lesions were opaque or patchy and light brown, and papillary microsurface structures were different in shapes and sizes. Intraepithelial microvessels were elongated, dilated, twisted and varied in diameter. Lugol iodine stain showed nil to faint staining. Histologically, the atypia cells were large with rounded to irregular nuclei, coarse chromatin, mitotic figures, and abundant eosinophilic cytoplasm. The basal cells showed increased atypia, crowding, increased nuclear-cytoplasmic ratio, and active mitosis. The cells were arranged haphazardly. Single cell keratinization, binuclear cells, and hollow-out-like cells, as well as surface epithelial keratinization and parakeratosis were observed in three cases. There were obvious verrucous or papillary structures in the epithelial layer. Five patients had local verrucous carcinoma. Immunohistochemical staining showed that the mutant expression of p53 protein in 6/10 cases; p16 was positive in 5/10 cases; abnormal Ki-67 distribution pattern in 10/10 cases. HPV was negative in all 10 cases tested. The original pathologic diagnosis of preoperative biopsy was high-grade dysplasia in 8 cases, low-grade dysplasia in 6 cases and atypical squamous epithelial cells in 4 cases. Conclusions: Esophageal verrucous dysplasia tumor cells are well differentiated with obvious verrucous or papillary structures. The unique morphological features suggest that it represents a histological subtype of esophageal squamous high-grade dysplasia and it is a precursor of verrucous carcinoma. Its preoperative biopsy diagnosis is challenging.

[Course of disease and related epidemiological parameters of COVID-19: a prospective study based on contact tracing cohort].

Objective: To analyze the course of disease and epidemiological parameters of COVID-19 and provide evidence for making prevention and control strategies. Methods: To display the distribution of course of disease of the infectors who had close contacts with COVID-19 cases from January 1 to March 15, 2020 in Guangdong Provincial, the models of Lognormal, Weibull and gamma distribution were applied. A descriptive analysis was conducted on the basic characteristics and epidemiological parameters of course of disease. Results: In total, 515 of 11 580 close contacts were infected, with an attack rate about 4.4%, including 449 confirmed cases and 66 asymptomatic cases. Lognormal distribution was fitting best for latent period, incubation period, pre-symptomatic infection period of confirmed cases and infection period of asymptomatic cases; Gamma distribution was fitting best for infectious period and clinical symptom period of confirmed cases; Weibull distribution was fitting best for latent period of asymptomatic cases. The latent period, incubation period, pre-symptomatic infection period, infectious period and clinical symptoms period of confirmed cases were 4.50 (95%CI:3.86-5.13) days, 5.12 (95%CI:4.63-5.62) days, 0.87 (95%CI:0.67-1.07) days, 11.89 (95%CI:9.81-13.98) days and 22.00 (95%CI:21.24-22.77) days, respectively. The latent period and infectious period of asymptomatic cases were 8.88 (95%CI:6.89-10.86) days and 6.18 (95%CI:1.89-10.47) days, respectively. Conclusion: The estimated course of COVID-19 and related epidemiological parameters are similar to the existing data.

[Spindle cell type squamous dysplasia of the esophagus: a clinicopathological analysis].

Objective: To investigate the clinicopathological features and significance of spindle cell type squamous dysplasia of the esophagus. Methods: The clinicopathological data of 37 cases of spindle cell type squamous dysplasia of esophagus were collected retrospectively at People's Liberation Army Joint Logistics Support Force 989 Hospital (formerly 152 Hospital), Pingdingshan, China, from 2009 to 2019. The histological and immunohistochemical characteristics were analyzed, with a literature review. Results: The median age of the 37 patients was 65 years (range 47-81 years), while the ratio of men to women was 1.5∶1.0. There were 4 cases in the upper esophagus, 31 in the middle esophagus and 2 in the lower esophagus. The median diameter of the lesions was 14 mm (range 3-40 mm). According to the Paris classification, 11 cases were 0-Ⅱa, 14 cases were 0-Ⅱb, 3 cases were 0-Ⅱb and 0-Ⅱa, and 9 cases were 0-Ⅱc. Under endoscope, the lesional mucosa was reddish. The micro-vessels were dilated, with various shapes and density. Histologically, tumor cells and nuclei were spindle shaped or elongated spindle shaped, with considerable homogeneity, dark nuclei and delicate or slightly thickened chromatin. The mitosis was conspicuous, and atypic mitoses were seen; the cytoplasm was acidophilic, and the intercellular bridge was obvious. The cells were dense and often lost polarity, but still arranged in parallel, mostly perpendicular to the basement membrane. Spindle cells often involved the whole layer of epithelium, with no gradient maturation and differentiation of normal squamous epithelium. The tumor was well demarcated. The spindle cells often invaded lamina propria. There were 15 cases with focal high-grade dysplasia and superficial invasive squamous cell carcinoma. Immunohistochemical staining showed that the mutation rate of p53 was 41.4% (12/29), the median of Ki-67 labeling index was 40% (range 20%-80%), and the abnormal distribution pattern of Ki-67 was 29 (100%). According to the initial pathological diagnosis, there were 6 cases of low-grade dysplasia, 4 cases of atypical epithelial cells and 27 cases of high-grade dysplasia and superficial invasive squamous cell carcinoma. Conclusions: Spindle tumor cells have moderate to severe atypia, and some tumors show invasive pattern. P53 mutation and Ki-67 abnormal distribution pattern indicate that they are high-grade dysplasia of esophageal squamous epithelium. The unique characteristics of spindle tumor cells suggest that they may represent a spindle cell subtype in the morphological spectrum of esophageal squamous dysplasia. When the knowledge of the lesion is insufficient, it can be easily misdiagnosed or missed.

[Clinicopathological features of basal cell type dysplasia of esophagus].

Objective: To investigate the clinicpathological features of basal cell type dysplasia of the esophagus. Methods: The clinicopathological data of 71 cases of basal cell type dysplasia of esophagus were collected at the People's Liberation Army Joint Logistics Support Force 989 Hospital, from 2009 to 2019, and the histomorphologic characteristics and immunophenotype were evaluated. The relevant literature was reviewed. Results: The ratio of male to female patients was 1.6∶1.0, and the median age was 65 years (range 48-81 years). The tumors were located in the upper segment of the esophagus in four cases (5.6%), the middle segment in 54 cases (76.1%), and the lower segment in 13 cases (18.3%).The median maximal tumor diameter was 12.0 mm (range 3-42 mm). According to Paris Classification, 0-Ⅱb accounted for 42.3% (30/71) of the cases. Under endoscope, the lesions were reddish with abnormal mucosal microvessels. Histologically, the neoplastic cells were small, with a high nuclear-cytoplasmic ratio, similar to basal cells, and uniform in morphology. The structural atypia was characterized by dense and disordered tumor cells, loss of basal cell polarity, and absence of normal squamous differentiation gradient. In 10 cases, the tumors were confined to the lower part of the epithelium. The tumor cells were smaller and more uniform in shape, and extend to the superficial lamina propria. Sixty-one tumors involved at least the entire layer of the upper cortex. There were 31 cases of neoplasms with superficial invasive carcinoma. The types of neoplasms included typical squamous cell carcinoma, basaloid squamous cell carcinoma, small cell neuroendocrine carcinoma, squamous cell carcinoma with sebaceous adenoid carcinoma, and differentiation of glandular/ductal epithelioid carcinoma. Immunohistochemical staining showed that the mutant expression rate of p53 protein was 41.5% (17/41). All 41 cases (100.0%) showed abnormal distribution pattern of Ki-67. According to the initial pathologic diagnosis, there were 18 cases of low grade dysplasia, 12 cases of atypical epithelial cells, and 41 cases of high grade dysplasia and superficially invasive carcinoma. Conclusions: Basal cell type dysplasia has unique morphologic characteristics and represents a tumor subtype in the morphologic lineage of esophageal squamous dysplasia. Tumor cells of basal cell type dysplasia, especially those distributed only in the lower part of the stratified squamous epithelium, may be tumor stem cells at the earliest stage of esophageal carcinogenesis and have multidirectional differentiation potential. When the tumor is confined to the lower part of the stratified squamous epithelium, it does not meet the diagnostic criteria for esophageal squamous dysplasia as defined by the current WHO classification.

[Pathological characteristics of colorectal adenoma with submucosal pseudoinvasion].

Objective: To investigate the pathomorphological characteristics of colorectal adenoma with submucosal pseudoinvasion and to summarize the corresponding pseudoinvasion patterns. Methods: The clinicopathological data of 9 cases of colorectal adenoma were collected at 989 Hospital of PLA Joint Logistics Support Force (4 cases) and Beijing Chaoyang Hospital, Capital Medical University (5 cases), from 2016 to 2019. retrospectively, and the histomorphological characteristics and immunophenotypes were analyzed, and discussed in light of the relevant literature. Results: There were 8 cases of adenoma with stalk. Tumor glands were found in the submucosa at the head end of adenoma, similar to infiltrating adenocarcinoma. The structure and cellular morphology of submucosal glands were very similar to the intramucosal tumor while the local submucosal tumor showed continuity with the intramucosal tumor. The submucosal tumors were lobule-like or nest-like with clear boundary. The outline of the gland was smooth and blunt-round, and there was loose fibromyxoid stroma around the gland, similar to the mucosa propria stroma. Some cases of the submucosal glands were cystic dilated with mucocele formation and hemosiderin deposition. One case with broad stalk-base showed an elevated adenoma with local high grade dysplasia involved in the aggregated lymphoid nodule, forming the lymphoglandular complexes, simulating invasive adenocarcinoma with associated submucosal lymphoid aggregates. Submucosal cancer tissue and intramucosal cancer tissue had continuity, and their morphology was the same. The submucosal tumor was round in the outline, smooth and blunt in the edge, and surrounded by lymphoid tissue. There was no stromal response around the gland to promote the proliferation of connective tissue, neither was there single-cell or small-cell cluster, sharp angle branch of gland, or vascular infiltration. Conclusions: There are two unique morphological patterns in colorectal adenoma with submucosal pseudoinvasion. Morphologically, the data show that one is lobular-like pattern, and the other is lymphoglandular complexes-like pattern. The main features of the two patterns are the same-morphology and continuity of submucosal tumor and intramucosal tumor. The pushed glands were surrounded by the intrinsic membrane stroma and muscularis mucosae in proper order, lacking the typical morphological characteristics of invasive adenocarcinoma.

[Experimental study on the improvement of Ilizarov transverse tibial bone transport and microcirculation reconstruction technique].

Objective: To observe the effect of traditional and modified Ilizarov transverse tibial bone transport on microvascular regeneration of lower limbs in dogs. Methods: After general anesthesia on 10 experimental dogs, traditional and modified transverse tibial bone transport were performed on both tibias respectively. The control group was treated with the traditional method (the periosteum and bone flap were completely isolated), while the experimental group was treated with the modified method (the fibular periosteum of the open window bone flap was retained). All the external fixators were pulled outwards at a speed of 1 mm every day from 5 days after operation;after one week, the external fixators were moved back every 3 days for one week. The situation of wounds and activity of lower limbs were observed. Simultaneously, the angiogenesis was observed by digital subtraction angiography (DSA) through femoral artery at different stages, and the density of vascular endothelial cells measured by local tissue sections. The data before and after the operation were compared with paired t test. Results: The operation was successfully completed in 10 experimental dogs, and all wounds healed about 1 week after the operation. There was no significant abnormality in lower limb movements in all dogs. Peripheral blood vessel area in middle leg of lower limb in 4 weeks and 8 weeks after operation was (5.9±0.4) mm(2) and (6.9±0.6) mm(2) in control group and it was (6.2±0.6) mm(2) and (8.0±0.6) mm(2) in experimental group, respectively; all were significantly improved than those before the operation ((5.0±0.4) mm(2), (4.9±0.4) mm(2), respectively) (F=446.457, 829.192, both P<0.05). There was no significant differences in vessel area between the two groups at the 4th week after operation (t=1.216, P=0.240), but there was significant difference at the 8th week after operation between the two groups (t=4.423, P=0.000). The percentage of vascular endothelial cells in stained cells under endoscopy was 4.42%±0.28% and 5.63%±0.53% in the control group at the 8th week; and in the experimental group, it was 5.35%±0.26% and 7.18%±0.25%, respectively;all were significantly elevated than those before the operation; and there were significant differences between the two groups (t=7.35, 8.30, both P<0.05). Conclusion: Transverse tibial bone transport and microvascular network regeneration technology can reconstruct the microvasculature below the calf of dogs; the method of window-opening osteotomy is improved to "door" type window-opening, it can retain the lateral periosteum of tibial crest and regenerate the microvasculature network more abundantly.

[Application of preventive flap-placement of terminal ileostomy in laparoscopic radical resection of low rectal cancer].

Objective: To evaluate the value of preventive flap placement of terminal ileostomy in laparoscopic radical resection of low rectal cancer. Methods: A retrospective analysis was conducted in the patients (n=63) who received preventive terminal ileostomy in laparoscopic radical resection of low rectal cancer in our institution from April 2016 to March 2018, including 33 patients who underwent ileostomy with flap-placement (flap group), and 30 patients who underwent ileostomy with stent (stent group). Clinical data were collected from both groups and statistically analyzed. Results: All patients were successfully completed laparoscopic radical resection with preventive ileostomy. All patients of stent group received stoma-closure surgery one month later after rectal resection. There were significantly statistical differences in operating time of ileostomy (28.9±4.3 vs 36.3±2.3, t=11.73, P<0.001) and overall stoma-related complications (1 vs 7, χ(2)=4.155, P=0.042), but no difference in anastomosis leakage, operating time of stoma-reversal, parastomal infection, parastomal hernia and parastomal prolapse. Conclusions: Preventive flap placement of terminal ileostomy represents a secure and feasible approach to laparoscopic low rectal cancer resection. Patients can be released from the discomfort of removing the stent and may suffer fewer stoma-related complications.

[Clinical effect of preservation of the left colonic artery in laparoscopic anterior resection for rectal cancer].

Objective: To evaluate the value and feasibility of preservation of the left colonic artery (LCA) in laparoscopic anterior resection for rectal cancer. Methods: The clinical data of 97 patiens who received laparoscopic anterior resection of rectal cancer from 2009.3 to 2015.3 were randomly divided into two groups, including 52 cases with preservation of LCA and 45 cases without preservation of LCA. The operation time, quantity of bleeding, number of lymph nodes removed around the root of inferior mesenteric artery (IMA), the rate of lymph node metastasis around the root of IMA, the incidence of transverse colostomy and anastomotic leak were compared between the two groups. Results: All 97 operations were successfully completed by laparoscopic operation. There were significantly statistical differences in operation time, quantity of bleeding and transverse colon stoma between two groups(P<0.05), but no difference in the number of lymph nodes removed and the rate of lymph node metastasis. Conclusions: The preservation of the left colonic artery in laparoscopic anterior resection of rectal cancer can preserve more supplying vessels for anastomosis and prevent anastomotic leak.

Molecular characterization, tissue expression, and polymorphism analysis of liver-type fatty acid binding protein in Landes geese.

Liver weight is an important economic trait in the fatty goose liver industry. Liver-type fatty acid binding protein (L-FABP) is involved in the formation and metabolism of fatty acids. Thus, we hypothesized that sequence polymorphisms in L-FABP were associated with fatty liver weight in goose. We first isolated, sequenced, and characterized the goose L-FABP gene, which had not been previously reported. The goose L-FABP gene was 2490 bp and included 4 exons coding for a 126-amino acid protein. Analysis of expression levels of the goose L-FABP gene in different tissues showed that the expression level in the liver tissue was higher than in other tissues, and was significantly higher in the liver tissue of overfed geese than in control geese. Moreover, a single nucleotide polymorphism located at 774 bp in the gene was identified in a Landes goose population. To test whether this single nucleotide polymorphism was associated with fatty liver production, liver weight and the ratio of liver to carcass weights were determined for the 3 genotypes with this single nucleotide polymorphism (TT, TG, GG) in overfed Landes geese. Our data indicate that individuals with the GG genotype had higher values for the variables measured than those with the other 2 genotypes, suggesting that L-FABP can be a selection marker for the trait of fatty liver production in goose.