[Clinicopathological features of fibrin-associated diffuse large B-cell lymphoma: a report of six cases]

Objective: To investigate the clinical, pathological and immunophenotypic features, molecular biology and prognosis of fibrin-associated large B-cell lymphoma (LBCL-FA) in various sites. Methods: Six cases of LBCL-FA diagnosed from April 2016 to November 2021 at the Beijing Friendship Hospital, Capital Medical University, Beijing, China and the First Affiliated Hospital, Wenzhou Medical University, Wenzhou, China were collected. The cases were divided into atrial myxoma and cyst-related groups. Clinical characteristics, pathological morphology, immunophenotype, Epstein Barr virus infection status, B-cell gene rearrangement and fluorescence in situ hybridization of MYC, bcl-2, bcl-6 were summarized. Results: The patients' mean age was 60 years. All of them were male. Three cases occurred in atrial myxoma background, while the others were in cyst-related background, including adrenal gland, abdominal cavity and subdura. All cases showed tumor cells located in pink fibrin clot. However, three cyst-related cases showed the cyst wall with obviously fibrosis and inflammatory cells. All cases tested were non germinal center B cell origin, positive for PD-L1, EBER and EBNA2, and were negative for MYC, bcl-2 and bcl-6 rearrangements, except one case with MYC, bcl-2 and bcl-6 amplification. All of the 5 cases showed monoclonal rearrangement of the Ig gene using PCR based analysis. The patients had detailed follow-ups of 9-120 months, were treated surgically without radiotherapy or chemotherapy, and had long-term disease-free survivals. Conclusions: LBCL-FA is a group of rare diseases occurring in various sites, with predilection in the context of atrial myxoma and cyst-related lesions. Cyst-related lesions with obvious chronic inflammatory background show more scarcity of lymphoid cells and obvious degeneration, which are easy to be missed or misdiagnosed. LBCL-FA overall has a good prognosis with the potential for cure by surgery alone and postoperative chemotherapy may not be necessary.

[Translocations of MYC, bcl-2 and bcl-6 genes and Epstein-Barr virus infection in primary cardiac large B-cell lymphoma]

Objective: To investigate the translocations of MYC, bcl-2 and bcl-6 genes, the Epstein-Barr virus (EBV) status and the clinicopathological features of primary cardiac large B cell lymphoma (LBCL). Methods: Seven cases of primary cardiac LBCL were collected at Beijing Friendship Hospital, Capital Medical University, China from February 2013 to May 2019. The clinical feature, pathological morphology and immunophenotype were analyzed. The detections of EBV and gene rearrangements of MYC, bcl-2 and bcl-6 were conducted. The 2017 WHO classification of tumors of haematopoietic and lymphoid tissues was used to classify the tumors. Results: Four patients with right atrial lesions showed diffuse infiltration of medium size lymphoid cells with small vascular hyperplasia, without evidence of EBV infection. Without detectable gene rearrangements of MYC and bcl-2, 2 of the patients showed bcl-6 gene break-apart. The diagnosis was revised from diffuse LBCL to high-grade B-cell lymphoma, not otherwise specified (HGBL-NOS). There was a case of CD5⁺ diffuse LBCL involving the right atrium and ventricle and 2 cases of fibrin-associated diffuse LBCL located at left atrium without gene rearrangements of MYC, bcl-2 and bcl-6. However, EBER and EBNA2 were highly expressed in fibrin-associated diffuse LBCL. The patients were followed up for 10-71 months. Four cases of HGBL-NOS and a case of CD5⁺ diffuse LBCL received R-CHOP with/without autologous stem cell transplantation. All but two patients survived. Two cases of fibrin-associated diffuse LBCL were disease free without adjuvant chemotherapy and radiotherapy. Conclusions: Primary cardiac LBCL is heterogeneous, including at least HGBL-NOS. Primary cardiac HGBL-NOS most frequently occurs in the right atrium. Tumor cells of primary cardiac LBCL have the morphological characteristics similar to Burkitt lymphoma, lacking MYC and bcl-2 gene rearrangements, but usually show bcl-6 gene disruption. Fibrin-associated diffuse LBCL has a good prognosis and postoperative chemotherapy seems unnecessary.

Measurement of the Cosmic Ray Helium Energy Spectrum from 70 GeV to 80 TeV with the DAMPE Space Mission

The measurement of the energy spectrum of cosmic ray helium nuclei from 70 GeV to 80 TeV using 4.5 years of data recorded by the Dark Matter Particle Explorer (DAMPE) is reported in this work. A hardening of the spectrum is observed at an energy of about 1.3 TeV, similar to previous observations. In addition, a spectral softening at about 34 TeV is revealed for the first time with large statistics and well controlled systematic uncertainties, with an overall significance of 4.3σ. The DAMPE spectral measurements of both cosmic protons and helium nuclei suggest a particle charge dependent softening energy, although with current uncertainties a dependence on the number of nucleons cannot be ruled out.

[Epidemiological characteristics and risk factors of Blastocystis hominis infection among patients with HIV/AIDS in Fuyang City Anhui Province]

OBJECTIVE

To investigate the prevalence and risk factors of Blastocystis hominis infections among patients with HIV/AIDS in Fuyang City, Anhui Province.

METHODS

A cross-sectional study was conducted in Fuyang City, Anhui Province in 2016. The demographic and socioeconomic status, and the lifestyle and production style were collected using a questionnaire survey. B. hominis DNA was detected in subjects'stool samples using a PCR assay, and the CD4+ T lymphocyte count and HIV viral load were measured in the subjects' blood samples. The risk factors of B. hominis infections among patients with HIV/AIDS were identified using univariate and multivariate logistic regression analyses.

RESULTS

A total of 398 HIV/AIDS patients were enrolled in this study, with a mean age of 49.3 years, a mean body weight of 55.9 kg and a mean height of 164.4 cm. The prevalence of B. hominis infection was 6.78% in the study subjects, and no gender- (χ² = 1.589, P = 0.207), education level- (χ² =0.508, P = 0.776), marital status- (χ² = 0.419, P = 0.811) or occupation-specific prevalence (χ² = 2.744, P = 0.615) was detected. Among the patients with HIV/AIDS, there were no significant differences in the age (t = 0.370, P = 0.712), height (t = 1.587, P =0.113), body weight (t = 0.516, P = 0.606), CD4⁺ T lymphocyte count (t = 1.187, P = 0.230) or HIV viral load (t = 0.193, P =0.496) between B. hominis-infected and uninfected individuals. Dinking non-tap water [OR = 6.554, 95% CI: (1.876 to 22.903)] and keeping dogs [OR = 5.895, 95% CI: (2.017 to 17.225)] were identified as risk factors for B. hominis infection in patients with HIV/AIDS.

CONCLUSIONS

The prevalence of B. hominis infection is high in HIV/AIDS patients, and drinking non-tap water and keeping dogs are risk factors for B. hominis infection among HIV/AIDS patients.

[EB virus-positive T/NK lymphoproliferative diseases: an analysis of 156 patients]

Objective: To investigate the clinicopathological features of EBV-positive T/NK cell lymphoproliferative diseases (EBV(+) T/NK-LPD). Methods: The clinical characteristics of 156 cases of EBV(+) T/NK-LPD were collected from August 2002 to March 2015 at Beijing Friendship Hospital, Capital Medical University. Immunohistochemical staining, EBER in situ hybridization and clonal analysis of TCR gene were performed. All patients were followed up. Results: There were 106 male and 50 female patients; patients' age ranged from 1 to 75 years (median 20 years). The course of the diseases before diagnosis ranged from 2 to 540 months (median 20 months). Fever was noted in 122 patients (78.2%), 108 patients had lymphadenopathy (69.2%), and 75 patients had hepatosplenomegaly (48.1%). Thirty-three cases were grade 1, 68 cases were grade 2, and 55 cases were grade 3. TCR gene arrangement analysis was performed in 45 cases, and 33 cases (73.3%) showed clonal rearrangement. The follow-up period ranged from 1-134 months, and 44 patients (28.2%) died. There was a trend of increased death rate associated with increasing grade (P>0.05). Conclusions: There are many types of EBV(+) T/NK-LPD, and they can be classified as systemic, relatively localized and localized. The prognosis should be based on a comprehensive analysis of pathology and clinical data. There is no significant correlation between morphological grade and mortality. An important goal of therapy is to prevent serious complications.

Antibiotic resistance and molecular characterization of diarrheagenic Escherichia coli and non-typhoidal Salmonella strains isolated from infections in Southwest China

BACKGROUND

Bacterial diarrhea is one of the most common causes for medical consultations, mortality and morbidity in the world. Diarrheagenic Escherichia coli (DEC) and non-typhoidal Salmonella (NTS) are major intestinal pathogens in developing countries, and the indiscriminate use of antibiotics has greatly contributed to resistant strains. Hence, the aim of the present study is to identify the antimicrobial resistance patterns and the molecular characteristics of DEC and NTS in southwest, China.

METHODS

1121 diarrheal patients and 319 non-diarrheal subjects across all age groups were recruited from four sentinel hospitals from June 2014 to July 2015 in Kunming City, Yunnan Province. Each stool specimen was collected to detect DEC and NTS with standard microbiological and molecular methods. Antimicrobial resistance testing was performed with the Kirby-Bauer disk diffusion method, and the standards for antimicrobial susceptibility testing complied with the Clinical and Laboratory Standards Institute (CLSI). Molecular characterization of strains was carried out using pulsed-field gel electrophoresis (PFGE). A structured questionnaire was used to record basic epidemiological data (e.g. sex, age, residence, season, etc.). Data were analyzed using Chi-square or Fisher's exact test.

RESULTS

DEC was detected in 127 (11.33%) diarrhea cases and 9 (2.82%) non-diarrheal cases (χ² = 20.69, P < 0.001, OR = 4.36, 95% CI: 2.19-8.65), and the prevalence of NTS isolated from diarrhea cases was higher than that of non-diarrheal cases across all age groups (n = 42, 3.75%, n = 1, 0.31%, χ² = 10.10, P = 0.002, OR = 12.38, 95% CI: 1.70-90.29). The rates of resistance to ten antibiotics of DEC and NTS showed significant differences (χ ²  = 386.77, P < 0.001; χ² = 191.16, P < 0.001). The rates of resistance to Amoxicillin and Clavulafiate (AMC), Cephalothin (CEP), Gentamicin (GEN) and Sulfamethoxazole-Trimethoprim (SXT) of DEC isolated from diarrhea cases were higher than those of NTS isolated from diarrhea patients (37.01% vs 14.29%, χ² = 7.57, P = 0.006; 29.92% vs 11.90%, χ² = 5.40, P = 0.02; 37.01% vs 11.90%, χ² = 5.80, P = 0.016; 62.20% vs 26.19%, χ² = 16.44, P < 0.001; respectively). Ciprofloxacin (CIP) was the most sensitive antibiotic for DEC and NTS strains isolated from diarrhea cases. Resistance rates of DEC isolates from cases and controls to more than three kinds antimicrobials (multidrug resistance, MDR) showed no significant differences (81.10% vs 88.89%, P = 0.33). Pulsotype patterns of DEC strains were highly diverse; however, the pulsotype pattern of NTS strains was closely related to the serotype. The pattern of S. enteritidis was highly similar, but the S. enterica Typhimurium strain was discrete.

CONCLUSIONS

Antibiotic resistance of Enterobacteriaceae is of great concern. The societal effects of antibiotic use justify strict monitoring to combat increases in antimicrobial resistance. Molecular epidemiology and systematic epidemiological investigation can provide accurate evidence for tracking the infection source.

[Quantitative assay of telomerase activity in head and neck squamous cell carcinoma]

OBJECTIVE

To detect and quantify telomerase activity in tissues from head and neck squamous cell carcinoma (HNSCC), and to explore whether the levels of telomerase activity can be a useful marker for cancer risk assessment in HNSCC.

METHOD

The levels of telomerase activity of 55 fresh specimens obtained from 25 patients with HNSCC were detected by the method of telomeric repeat scintillation radioactive count, including 25 primary tumors, 7 samples of neck metastases and 23 corresponding normal tissues as control. In 7 patients, both primary and metastatic tumors were obtained. The levels of telomerase activity were determined with a liquid scintillation counter. The basic principle of the technique is that a G-rich oligonucleotide strand of telomeric sequence is used as primer, 3H-dTTPs are incorporated into the products while telomerase elongates the primers, and then free 3H-dTTPs are removed by rinsing step, finally radioactive count per minute (cpm) of products is detected, and the levels telomerase activity can be evaluated according to the value (cpm).

RESULT

1. The levels of telomerase activity (cpm) in tissues with HNSCC were significantly higher than those in the normal tissues (P < 0.05); 2. The levels of telomerase activity in the primary tumors were higher than those of their neck metastases, but the difference was not statistical significance (P > 0.05); 3. The levels of telomerase activity in the neck metastases were remarkably higher than those in the normal tissues (P < 0.05).

CONCLUSION

1. Detection of telomerase activity in HNSCCs can be a useful marker for cancer assessment. 2. To quantify telomerase activity may have clinical diagnostic value for HNSCC. 3. The levels of telomerase activity in the metastatic lymph nodes were higher.