[Role of DNMT3a in Hydroquinone-Induced Hematopoietic Stem Cell Toxicity].

OBJECTIVE: To investigate the regulatory effect and mechanism of DNA methyltransferase 3A (DNMT3a) in hydroquinone-induced hematopoietic stem cell toxicity. METHODS: Cells (HSPC-1) were divided into 4 groups, that is A: normal HSPC-1; B: HQ-intervented HSPC-1; C: group B + pcDNA3 empty vector; D: group B + pcDNA3- DNMT3a. RT-qPCR and Western blot were used to detect the expression levels of DNMT3a and PARP-1 mRNA and protein, respectively. Cell morphology was observe; Cell viability and apoptosis rate of HSPC-1 were detected by MTT and flow cytometry, respectively. RESULTS: Compared with group A, the expression levels of DNMT3a mRNA and protein in HSPC-1 of group B were decreased, while PARP-1 mRNA and protein were increased (P<0.05); there was no significant difference in the above indexes between group C and group B; compared with group B, the expression levels of DNMT3a mRNA and protein showed increased, while PARP-1 mRNA and protein were decreased significantly in cells of group D transfected with DNMT3a (P<0.05). Cells in each group were transfected with DNMT3a and cultured for 24 h, HSPC-1 in group A showed high density growth and mononuclear fusion growth, while the number of HSPC-1 in group B and C decreased and grew slowly. Compared with group B and C, the cell growth rate of group D was accelerated. The MTT analysis showed that cell viability of HSPC-1 in group B were lower than that of group A at 24 h, 48 h and 72 h (P<0.05); after transfected with DNMT3a, the cell viability of HSPC-1 in group D were higher than that of group B at 24 h, 48 h and 72 h (P<0.05). The apoptosis rate of cells in group B was significantly higher than that of group A (P<0.001), while the apoptosis rate in group D was lower than that of group B (P<0.001). CONCLUSION: DNMT3a may be involved in the damage of hematopoietic stem cells induced by hydroquinone, which may be related to the regulation of PARP-1 activity by hydroquinone-inhibited DNMT3a.

Progress in the Study of Epidemiologic Characteristics and Influencing Factors of Asymptomatic Malaria Infection in Africa.

Malaria is caused by protozoan parasitic Plasmodium infections. Plasmodium falciparum is common in Africa; P ovale, P malaria and P vivax infections are less prevalent and globally confined, contributing to major causes of global mortality and morbidity, particularly in children in sub-Saharan African countries. In 2018, the total incidence of malaria increased from 221 million to 229 million, with an estimated 503 000 deaths reported. Sub-Saharan Africa has the highest number of cases of malaria and highest mortality rate compared with other countries, like southeastern Asia, east Pacific, western, and America with an estimated 213 million cases. In addition, continuous exposure to Plasmodium parasites results in the production of partial immunity to guard against more problems, resulting in asymptomatic carriers. The diagnosis of asymptomatic malaria is not simple because of the apparent absence of clinical factors and sometimes low levels of parasites. The most basic concept appears to be parasitemia and a lack of malaria signs, primarily fever (axillary temperature <37.5° C). Thus, a better awareness of asymptomatic malaria epidemiology in affected countries will help improve strategies to reduce the local burden of malaria and its health consequences. Therefore, the objective of this study was to determine the magnitude of asymptomatic malaria pathology and related risk factors with epidemiologic characteristics in individuals on the African continent.

Nocardia Infection in Nephrotic Syndrome Patients: Three Case Studies and A Systematic Literature Review.

OBJECTIVE: The multicenter literature review and case studies of 3 patients were undertaken to provide an updated understanding of nocardiosis, an opportunistic bacterial infection affecting immunosuppressed nephrotic syndrome (NS) patients receiving long-term glucocorticoid and immunosuppressant treatment. The results provided clinical and microbiological data to assist physicians in managing nocardiosis patients. METHODS: Three cases between 2017 and 2018 from a single center were reported. Additionally, a systematic review of multicenter cases described in the NCBI PubMed, Web of Science, and Embase in English between January 1, 2001 and May 10, 2021 was conducted. RESULTS: This study described three cases of Nocardia infection in NS patients. The systematic literature review identified 24 cases with sufficient individual patient data. A total of 27 cases extracted from the literature review showed that most patients were > 50 years of age and 70.4% were male. Furthermore, the glucocorticoid or corticosteroid mean dose was 30.9 ± 13.7 mg per day. The average time between hormone therapy and Nocardia infection was 8.5 ± 9.7 months. Pulmonary (85.2%) and skin (44.4%) infections were the most common manifestations in NS patients, with disseminated infections in 77.8% of patients. Nodule/masses and consolidations were the major radiological manifestations. Most patients showed elevated inflammatory biomarkers levels, including white blood cell counts, neutrophils percentage, and C-reactive protein. Twenty-five patients received trimethoprim-sulfamethoxazole monotherapy (18.5%) or trimethoprim-sulfamethoxazole-based multidrug therapy (74.1%), and the remaining two patients (7.4%) received biapenem monotherapy. All patients, except the two who were lost to follow-up, survived without relapse after antibiotic therapy. CONCLUSIONS: Nephrotic syndrome patients are at high risk of Nocardia infection even if receiving low-dose glucocorticoid during the maintenance therapy. The most common manifestations of nocardiosis in NS patients include abnormal lungs revealing nodules and consolidations, skin and subcutaneous abscesses. The NS patients have a high rate of disseminated and cutaneous infections but a low mortality rate. Accurate and prompt microbiological diagnosis is critical for early treatment, besides the combination of appropriate antibiotic therapy and surgical drainage when needed for an improved prognosis.

PCR-detectable Candida DNA exists a short period in the blood of systemic candidiasis murine model.

Invasive candidiasis is a major challenge to clinical medicine today. However, traditional fungal diagnostic techniques and empirical treatments have shown great limitations. Although efforts are necessarily needed in methodology standardization and multicenter validation, polymerase chain reaction (PCR) is a very promising assay in detecting fungal pathogens. Using a "heat-shock" DNA preparation method, a rapid and simple PCR protocol for quantification of the Candida albicans (C. albicans) ribosomal DNA was established. The PCR assay could detect Candida DNA as low as 10 CFU/mL in samples prepared by the heat-shock protocol, without any cross-reaction with DNA prepared from other Candida spp. and bacterial pathogens. For simulated blood samples, the PCR test sensitivity of whole blood samples was better than that of plasma and blood cells. In the systemic candidiasis murine model, detectable DNA was only observed within 24 h after C. albicans SC5314 injection, which is much shorter than that observed in the kidney.

Development of a Lateral Flow Immunoassay for the Rapid Diagnosis of Invasive Candidiasis.

Early and accurate diagnosis of invasive candidiasis (IC) is very important. In this study, a lateral flow immunoassay (LFIA) was developed to detect antibody against Candida albicans enolase (Eno). Colloidal gold particle labeled mouse anti human IgG (1.0 mg/L) was used as the detector reagent. Recombinant enolase (rEno, 1.0 mg/L) and goat anti IgG (1.0 mg/L) were immobilized in test and control lines, respectively, of a nitrocellulose membrane, acting as the capture reagents. The LFIA was used to detect anti Eno in 38 sera from clinically proven IC patients, as well as in 50 healthy control subjects. Compared with an indirect ELISA designed as a reference test, the specificity and sensitivity of the LFIA were 98.2 and 84.8%, respectively. Excellent agreement between the results obtained by ELISA and the LFIA (κ = 0.851) was observed in this study. In addition, the agreement between the blood culture results and LFIA test is strong (κ = 0.658). The data presented in the study indicate that the LFIA test is a suitable tool for the serological surveillance of IC in the field or in poorly equipped laboratories.

Serological response and diagnostic value of recombinant candida cell wall protein enolase, phosphoglycerate kinase, and ß-glucosidase.

There are no specific signs and symtoms for invasive candidiasis (IC), which makes its diagnosis a challenge. Efforts have been made for decades to establish serological assays for rapid diagnosis of IC, but none of them have found widespread clinical use. Using a systemic candiasis murine model, serological response to recombinant proteins of enolase (rEno1), phosphoglycerate kinase (rPgk1), and ß-glucosidase (rBgl2) were evaluated and rEno1 was found to possess the strongest immunoreactivity, followed by rPgk1 and rBgl2. Likewise, IgG antibody titers to rEno1, rPgk1, and rBgl2 in the positive sera of proven IC patients were determined by ELISA. Results show anti-rEno1 antibody possesses the highest titer, followed by rPgk1 and rBgl2. Antibodies against rEno1, rPgk1, and rBgl2 were detected by ELISA tests in a group of 52 proven IC patients or 50 healthy subjects, The sensitivity, specificity, positive and negative predictive values were 88.5, 90.0, 90.2, and 88.2% for anti-rEno1 detection, 86.5, 92.0, 91.8, and 86.8% for anti-rPgk1 detection, and 80.8, 90.0, 89.4, and 81.8% for anti-rBgl2 detection, respectively. The data clearly demonstrate that the recombinant proteins of Eno1, Pgk1, and Bgl2 are promising candidates for IC serodiagnosis. There's great possibility that the recombinant Eno1 will be more applicable in serodiagnosis and vaccine research on account of its strong serological response.

[Relationship between pathological alterations of spermatogenic impairment and serum inhibin B concentration in patients with azoospermia].

OBJECTIVE: To investigate the relationship between pathological alterations of spermatogenic impairment in seminiferous tubules and serum inhibin B concentration in patients with azoospermia and to verify the significance of INH B in evaluating spermatogenesis. METHODS: Eighty-three cases of azoospermia underwent testicular biopsy for the purpose of diagnosis. In accordance with the pathological alterations of spermatogenesis in seminiferous tubules, the samples were divided into four groups: Sertoli cell-only syndrome (n = 21); hypospermatogenesis (n = 20); maturation arrest (n = 24) and almost normal spermatogenesis (n = 18). Serum INHB and FSH, LH, T concentrations were tested before testicular biopsy for each patient respectively. RESULTS: The INHB levels were (20. 85 +/- 18.78) pg/ml, (67.25 +/- 40.98) pg/ml, (73.63 +/- 25.54) pg/ml and (149.48 +/- 27.92) pg/ml in the above four groups, respectively. There was no significant statistical difference in the level of serum INH B between maturation arrest and hypospermatogenesis groups (P > 0.05), and there was a very significant difference in almost normal spermatogenesis group and the other three groups, respectively (P < 0.001). There was no significant difference in the concentration of serum FSH when maturation arrest group compared with spermatogenesis group (P > 0.05), whereas between the other two groups and between each of them and maturation arrest or almost normal spermatogenesis there was a very significant difference in the level of serum FSH (P < 0.05); The concentrations of LH and T were not significantly different among the four groups (P > 0.05). CONCLUSION: Serum INHB concentration was decreased when spermatogenesis got impaired. It dropped the most markedly in Sertoli cell-only syndrome group. INH B reflects directly the spermatogenic function in seminiferous tubules of the testis. Therefore, it could be considered valuable for spermatogenesis and potential fertility in patients with azoospermia.