[Investigation for pathological interpretation criteria and its prognostic value for P53 expression in Chinese diffuse large B-cell lymphoma].

Objective: To explore the feasibility of predicting TP53 mutation risk by immunohistochemical staining (IHC) pattern of P53 in Chinese diffuse large B-cell lymphoma (DLBCL) and its correlation with a prognostic difference. Methods: Between January 2021 and December 2021, 51 DLBCL cases at Beijing Boren Hospital were gathered. These cases had both IHC and next-generation sequencing (NGS) results. IHC classified the P53 protein expression pattern into a loss (<1% ) , diffuse (>80% ) , and heterogeneous (1% -80% ) . The sensitivity and specificity of the predicting TP53 mutation by IHC were assessed by comparing the results of the NGS, and the TP53 high mutation risk group included both loss and diffuse expression of P53. From June 2016 to September 2019, Peking University Cancer Hospital collected 131 DLBCL cases with thorough clinicopathological and follow-up data. From their tumor blocks, tissue microarray blocks were made for IHC evaluation of P53 expression pattern, and prognosis effect of P53 studies. Results: Among 51 cases with both IHC and NGS results, 23 cases were classified as TP53 high mutation risk (7 cases loss and 16 cases diffuse) , 22/23 cases were proved with mutated TP53 by NGS. Only 1 of the 28 cases classified as TP53 low mutation risk was proved with mutated TP53 by NGS. IHC had a sensitivity and specificity of 95.7% and 96.4% for predicting TP53 mutation. NGS identified a total of 26 TP53 mutations with a mutation frequency of 61.57% (13.41% -86.25% ) . In the diffuse group, 16 missense mutations and 2 splice mutations were detected; 6 truncating mutations and 1 splice mutation were detected in the loss group; 1 truncating mutation was detected in the heterogeneous group. Multivariate analysis demonstrated that TP53 cases with high mutation risk have impartial adverse significance for the 131 patients included in survival analysis (HR=2.612, 95% CI 1.145-5.956, P=0.022) . Conclusion: IHC of P53 exhibiting loss (<1% ) or diffuse (>80% ) pattern indicated TP53 high mutation risk, IHC can predict TP53 mutation with high specificity and sensitivity. TP53 high mutation risk is an independent predictor for adverse survival.

[The pathological diagnosis and differential diagnosis of hematopoietic cell tumors of ambiguous lineage].

Objective: To explore the key points of the pathological and differential diagnoses of extra-medullary masses of hematopoietic cell tumors of ambiguous lineage, and to discuss the possible solutions. Methods: Five hematopoietic cell tumors of ambiguous lineage cases were collected, including myeloid sarcoma, mixed phenotype acute leukemia, B/myeloid, T-lymphoblastic lymphoma combined with acute myeloid leukemia, acute undifferentiated leukemia with cutaneous MPDCP and early T-precursor cell acute lymphoblastic leukemia. The data including morphology, immunostaining, and flow cytometry analysis were collected, and we explored the problems and differential diagnosis in the diagnosis of hematopoietic cell tumors of ambiguous lineage. Results: The five cases showed that the accurate pathological diagnosis and classification of hematopoietic cell tumors of ambiguous lineage should be based on lineage-specific antigens. Moreover, tumor cells have the potential of multi-directional differentiation. In different sites or different periods, the differentiation of tumor cells may be different. Biopsy and detection of all related markers should be performed for the initial diagnosis, and the detection should be repeated when the condition of the patient changes. Combined application of multi-techniques, including morphology and flow cytometry analysis, is recommend for the diagnosis of hematopoietic cell tumors of ambiguous lineage, since the conventional morphology and immunophenotyping methods are limited. Conclusion: Hematopoietic cell tumors of ambiguous lineage are derived from hematopoietic stem cells with a potential of multi-differentiation. The differentiation of tumor cells is variable. We need to integrate cell morphology, flow cytometry, pathology, clinical data, and molecular genetics to make a comprehensive diagnosis.

[Effects of 7 d -6 degrees bed-rest on postural equilibrium].

OBJECTIVE: To quantitatively assess the effects of 7 d -6 degrees head-down bed-rest (HDBR) on postural equilibrium and to investigate the contributions of vestibular, somatosensory and visual informations to postural equilibrium. METHOD: Eight healthy males, aged 33 - 42 years, were exposed to -6 degrees head-down tilt bed rest for 7 d. Sensory Organization Test (SOT) and Motor Coordination Test (MCT) were measured before and after HDBR, and day 4 of recovery. RESULT: Equilibrium scores of SOT in condition 1 (eyes opened, platform and visual scence environment fixed), 5 (eyes closed visual scence environment fixed, platform movable) were significantly lower as compared with pre-HDBR value, and recovered to pre-HDBR level on day 4 of recovery. Postural strategy scores of SOT in condition 1, 2 (eyes closed, platform and visual scence environment fixed) and 3 (eyes opened, platform fixed, visual scence environment movable) were significantly lower as compared with pre-HDBR value, and recovered to pre-HDBR level on day 4 of recovery. The dependence of somatosensory and visual information (ratio pair codition 2/condition 1, condition 3/condition 1 in sensory analysis) was significantly higher as compared with pre-HDBR value, and recovered on day 4 of recovery. Mean SOT alignment scores in conditions 1, 4 (eyes opened, visual scence environment fixed, platform movable) and 6 (eyes opened, platform and visual scence environment movable) were significantly higher as compared with pre-HDBR value, and only the scores of conditions 1, 6 were recovered on day 4 of recovery, but that of condition 4 did not. Mean postural-evoked response latencies of MCT were not significantly different as compared with pre-HDBR value. CONCLUSION: 7 d -6 degrees head-down tilt bed-rest has significant effects on postural equilibrium. The contributions of somatosensory and visual informations to postural equilibrium are increased.

[Effect of 7 d -6 degrees head-down tilt (HDT) on electromyogram of gastrocnemius and anterior tibialis muscles].

Objective. To assess the effect of 7 d -6 degrees HDT on electromyogram of the weightbearing muscles. Method. Eight healthy males, aged 33-42, were exposed to -6 degrees HDT bed-rest for 7 d, electromyogram from the gastrocnemius and anterior tibialis muscles were recorded before and after HDT, and day 4 of recovery. Result. The latency of SLR (short latency response) recorded from lower leg muscles after HDT was not different from that pre-HDT. But the latency of MLR (middle latency response) and LLR (long latency response) after HDT were significantly increased as compared with that pre-HDT, and recovered to pre-HDT level on day 4 of recovery. The durations of SLR recorded from right leg muscles after HDT were significantly longer as compared with that pre-HDT, and did not recover. The integrated amplitude of SLR and MLR after HDT were significantly increased as compared with that pre-HDT, and only the integrated amplitude of SLR recovered, but that of MLR did not. Conclusion. Seven day -6 degrees HDT bed-rest had significant effects on electromyogram of the weightbearing muscles.