T cells are divided into two subsets,αβΤandγδT cells, according to the T-cell recep-tor ( TCR) expressed. γδT cells are a small minority of T cells and in contrast to αβΤ cells, they do not seem to require antigen processing and major-histocompatibility-complex ( MHC ) presentation of peptide epitopes. This group of T cells is usually much less common than αβT cells, but plays an important role in anti-infection, anti-tumor and immunoregulation. This review summarizes the production, development, dis-tribution, genetic characteristics, antigen recognition characteristics, biological and immunological functions of γδT cells as well as their unique roles and mechanisms in bacterial infectious diseases.

Objective:To investigate the relationship between Watchman occluder and structure of mitral valve apparatus in patients with nonvalvular atrial fibrillation after left atrial appendage closure(LAAC) by transesophageal echocardiography.Methods:From January 2018 to December 2020, 29 patients [20 male, 9 female, (69.55±10.06)years old] with nonvalvular atrial fibrillation underwent LAAC in Zhongshan Hospital (implanted Watchman occluder), and all patients underwent pre-operative and follow-up two and three dimensional transesophageal echocardiography(2DTEE, 3DTEE) at 60 days after the operation. The quantitative parameters of mitral valve apparatus were obtained by offline analysis using the MVA module in QLab 13.0 (Philips Healthcare, Andover, MA), the differences between pre-operation and post-operation were compared, and the relationship between occluder compression ratio and mitral valve parameters with significant changes after operation was analyzed.Results:①The values of AL-PM diameter(AL-PM), 3D annulus circumference(3DAC), 2D annulus area(2DAA), 3D annulus area(3DAA), tenting volume(TnV), tenting area(TnA) and commissural diameter(CD) decreased significantly compared with pre-operative values(all P<0.05), while the annulus sphericity index(SPI) increased significantly ( P<0.05). ②In the quantitative mitral value parameters with significant pre- and post-operation changes, TnV was correlated with the occluder compression ratio ( r=0.403, P=0.030), but AL-PM, SPI, 3DAC, 2DAA, 3DAA, TnA, CD were not correlated with it(all P>0.05). Conclusions:3DTEE can accurately evaluate the effect of Watchman occluder on the morphology of mitral valve device. Implanting Watchman occluder in left atrial appendage can make three-dimensional mitral valve apparatus flat and decrease annulus left-right diameter and annulus area; the pre-operative TnV, the more susceptible to the occluder implantation, and TnV is correlated with the compression ratio.

ObjectiveTo investigate the clinicopathological features， diagnosis and treatment methods， and prognosis of gallbladder sarcomatoid carcinoma （GBSC）. MethodsA retrospective analysis was performed for the clinical data of 16 patients with GBSC who were admitted to The First Affiliated Hospital of Zhengzhou University from January 2015 to April 2023， including general information， clinical manifestations， imaging features， pathological features， and treatment modality， and follow-up was performed for all patients. The Kaplan-Meier method was used to perform the survival analysis and plot the survival curve， and the Log-rank test was used for comparison between groups. ResultsAmong the 16 patients， there were 6 male patients and 10 female patients， with a mean age of 62.9±8.4 years. The main clinical manifestations were right upper abdominal pain in 13 patients （81.3%）， nausea in 5 patients （31.3%）， abdominal distension in 4 patients （25.0%）， poor appetite in 3 patients （18.8%）， weakness in 2 patients （12.5%）， fever in 2 patients （12.5%）， and jaundice in 1 patient （6.3%）， and 3 patients were asymptomatic and were found to have this disease by physical examination. Of all patients， 81.3% （13/16） were in the advanced stage （stage Ⅲ/Ⅳ） at the time of initial diagnosis. Histopathological examination showed that some cancer cells were spindle-shaped under the microscope， with marked nuclear division and noticeable heteromorphism. Immunohistochemistry showed a positive expression rate of 100% （16/16） for Vimentin， AE1/AE3， and CK8/18， and Ki-67 proliferation index was highly expressed in 81.3% （13/16） of the patients （≥50%）， with a median of 70% （range 20%‍ ‍—‍ ‍90%）. All 16 patients underwent surgical treatment， with radical surgery in 11 patients and palliative surgery in 5 patients， among whom 9 received R0 resection， 2 received R1 resection， and 5 received R2 resection， and 7 patients received adjuvant therapy after surgery. Effective follow-up was achieved for all 16 patients， with a follow-up time of 0.5‍ ‍—‍ ‍26.0 months and a median follow-up time of 11.0 months. By the end of follow-up， 2 patients survived and 14 patients died due to tumor recurrence or metastasis， with a median survival time of 10.0 months， and the 1- and 2-year cumulative survival rates after surgery were 31.3% and 8.3%， respectively. The prognostic analysis showed that TNM stage （χ²=6.727， P=0.009）， surgical approach （χ²=7.508， P=0.006）， margin condition （χ²=7.934， P=0.005）， and adjuvant therapy （χ²=4.608， P=0.032） were associated with the prognosis of patients. ConclusionThe clinical manifestations of GBSC lack specificity， and a confirmed diagnosis relies on immunohistochemical analysis. Most patients are in the advanced disease at the time of initial diagnosis and tend to have a poor prognosis. There are currently no targeted therapies for this disease， and radical surgery with negative margins and adjuvant therapy can improve the survival rate of patients.