Recognition of refractory Mycoplasma pneumoniae pneumonia among Myocoplasma pneumoniae pneumonia in hospitalized children: development and validation of a predictive nomogram model.

BACKGROUD: The current diagnostic criteria for refractory Mycoplasma pneumoniae pneumonia (RMPP) among Mycoplasma pneumoniae Pneumonia (MPP) are insufficient for early identification, and potentially delayed appropriate treatment. This study aimed to develop an effective individualized diagnostic prediction nomogram for pediatric RMPP. METHODS: A total of 517 hospitalized children with MPP, including 131 with RMPP and 386 without RMPP (non-RMPP), treated at Lianyungang Maternal and Child Health Care Hospital from January 2018 to December 2021 were retrospectively enrolled as a development (modeling) cohort to construct an RMPP prediction nomogram. Additionally, 322 pediatric patients with MPP (64 with RMPP and 258 with non-RMPP, who were treated at the Affiliated Hospital of Xuzhou Medical University from June 2020 to May 2022 were retrospectively enrolled as a validation cohort to assess the prediction accuracy of model. Univariable and multivariable logistic regression analyses were used to identify RMPP risk factors among patients with MPP. Nomogram were generated based on these risk factors using the rms package of R, and the predictive performance was evaluated based on receiver operating characteristic (ROC) curves and using decision curve analysis (DCA). RESULTS: Multivariate analysis revealed five significant independent predictors of RMPP among patients with MPP: age (hazard ratio [HR] 1.16, 95% confidence interval [CI] 1.08-1.33, P = 0.038), fever duration (HR 1.34, 95%CI 1.20-1.50, P < 0.001), lymphocyte count (HR 0.45, 95%CI 0.23-0.89, P = 0.021), serum D-dimer (D-d) level (HR 1.70, 95%CI 1.16-2.49, P = 0.006), and pulmonary imaging score (HR 5.16, 95%CI 2.38-11.21, P < 0.001). The area under the ROC curve was 90.7% for the development cohort and 96.36% for the validation cohort. The internal and external verification calibration curves were almost linear with slopes of 1, and the DCA curve revealed a net benefit with the final predictive nomogram. CONCLUSION: This study proposes a predictive nomogram only based on five variables. The nomogram can be used for early identification of RMPP among pediatric patients with MPP, thereby facilitating more timely and effective intervention.

Case report: Fatal infantile hypertonic myofibrillar myopathy with compound heterozygous mutations in the CRYAB gene.

Background: Fatal infantile hypertonic myofibrillar myopathy (FIHMM) is an autosomal recessive hereditary disease characterized by amyotrophy, progressive flexion contracture and ankylosis of the trunk and limb muscles, apnea and respiratory failure, and increased creatine phosphate levels. It is caused by mutations in the CRYAB gene, and only around 18 cases including genetic mutations have been reported worldwide. All patients with FIHMM develop respiratory distress, progressive stiffness of the limbs, and have a poor prognosis. However, no effective treatment for CRYAB-associated respiratory failure has been reported. Here, we report a case of FIHMM with a novel heterozygous missense mutation. Case Presentation: A 2-year-old female developed scoliosis of the lumbar spine and restrictive ventilatory dysfunction in infancy. She was admitted to the hospital with labored breathing on the third day after the second injection of inactivated poliomyelitis vaccine. Acute respiratory failure, pneumothorax, and cardiac arrest arose in the patient during hospitalization, and progressive stiffness of the trunk and limb muscles appeared, accompanied by obvious abdominal distension and an increase in phosphocreatine kinase levels. Screenings for genetic metabolic diseases in the blood and urine were normal. Electromyography revealed mild myogenic damage. A muscle biopsy indicated the accumulation of desmin, α-crystallin, and myotilin in the musculus biceps brachii, and dense granules were observed in muscle fibers using electron microscopy. Mutation analysis of CRYAB revealed a novel heterozygous missense mutation in the proband, c.302A > C (p.His101Pro) and c.3G > A (p.Met1Ile), which inherited from her asymptomatic, heterozygous carrier parents, respectively. The proband was finally diagnosed as FIHMM. One month after the FIHMM diagnosis, the child died of respiratory failure. Conclusion: We report a case of FIHMM with a novel heterozygous missense mutation of CRYAB. This finding might improve our understanding of FIHMM and highlight a novel mutation in the Chinese population.

Apoptosis in human myelodysplastic syndrome CD34+ cells is modulated by the upregulation of TLRs and histone H4 acetylation via a ß-arrestin 1 dependent mechanism.

Excessive apoptosis of hematopoietic precursors in the bone marrow underlies the ineffective hematopoiesis characteristic of myelodysplastic syndrome (MDS). Toll-like receptor (TLR) signaling is abnormally activated in MDS and may be involved in excessive programmed cell death in the pathogenesis of MDS. TLRs expression and global histone H3/H4 acetylation were analyzed in bone marrow (BM) CD34+ cells from 20 lower-risk and 20 higher-risk MDS patients and 10 healthy controls. Apoptosis of BM CD34+ cells was examined by flow cytometry, and its correlation to histone acetylation and the expression of TLR2 and ß-arrestin1 (ß-arr1), measured by enzyme-linked immunosorbent assay and qRT-PCR, was assessed. TLR1, TLR2 and TLR6 expression and H4 acetylation levels were higher in lower-risk MDS patients than in higher-risk MDS patients or controls, and TLR2 expression and H4 acetylation levels were positively correlated with an increased rate of apoptosis. Lower-risk MDS was associated with increased ß-arr1 expression and histone acetyltransferase p300 activity. In in vitro-cultured primary normal and lower-risk MDS CD34+ cells, TLR2 activation-induced apoptosis was mediated by the upregulation of ß-arr1 leading to the recruitment of p300 and increased histone H4 acetylation. The nuclear accumulation of ßarr1 following TLR2 activation promote H4 acetylation at specific target gene promoters and may thus affect transcription of target genes in BM CD34+ cells. The mechanisms underlying the deregulation of TLR2 and increased apoptosis in MDS may involve the ß-arr1 mediated recruitment of p300 leading to increased levels of histone H4 acetylation.

Clinical study on the effect of Shengxueling on idiopathic thrombocytopenic purpura.

OBJECTIVE: To observe the clinical effect of Shengxueling (SXL) on idiopathic thrombocytopenic purpura (ITP), and study the possible mechanism. METHODS: Eighty-six cases of ITP were randomly divided into two groups. The SXL group, 56 patients treated with SXL, a traditinal Chinese medicine and 30 patients administered with prednisone were taken as control. Each group took drugs for 3 months and was under follow-up observation. RESULTS: In the SXL group, the total effective rate was 85.71%, similar to prednisone 83.33% (P > 0.05) for 3 months, but the total effective rate of SXL (91.07%) were obviously better than that of the control group (53.33%) (P < 0.01) for 6 months and had no obvious adverse reaction. The patients bleeding was alleviated or stopped, the general condition was improved. At the same time, blood platelet count (PLT) was increased, platelet associated immunoglobulin (PAIg) and interleukin-4 (IL-4) were markedly dropped, the level of natural killers cells activity (NKa) increased, the rate of T lymphocyte subsets gradually returned to normal level. Megakaryocyte tended to maturation on bone marrow smear after treatment. All differences above were statistically significant. CONCLUSION: SXL is an effective and safe medicine for ITP. Its mechanism could regulate cytoimmune, inhibit platelet antibody to reduce the destruction of platelet, increase the number of platelet, promote the division and maturation of megakaryocyte, facilitate the production and release of platelet, lower the fragility of capillary, prevent and cure hemorrhagic tendency.

[Clinical study on idiopathic thrombocytopenic purpura treated with Shengxueling Granule].

OBJECTIVE: To observe the clinical effect of Shengxueling Granule (SXLG) in treating idiopathic thrombocytopenic purpura (ITP), and to study its possible mechanism. METHODS: Eighty-six cases of ITP were divided into two groups randomly. Fifty-six cases in the treatment group were treated with SXLG, a traditional Chinese medicine, and 30 cases administered with Western medicine (prednisone) were taken as control. Patients in each group took drugs for three months and were under follow-up observation. RESULTS: In SXLG-treated group, the total effective rate in 3 months was 85.71%, similar to 83.33% in prednisone-treated group (P>0.05), while the total effective rate in 6 months in the SXLG-treated group was 91.07%, higher than 53.33% of the prednisone-treated group (P<0.01), and no obvious side-effects were observed. The patients' bleeding was alleviated or stopped, and their general condition was improved. And the blood platelet count (BPC) was increased, the platelet associated immunoglobulin (PAIg) and interleukin-4 (IL-4) were markedly dropped, the level of natural killer cells activity (NKCA) increased, and the rate of T lymphocyte subsets gradually returned to normal level. Megakaryocytes tended toward maturation on bone marrow smear after SXLG treatment. All differences above were statistically significant. CONCLUSION: SXLG is an effective and safe medicine for ITP. It can regulate the cellular immunity, inhibit the platelet antibody to reduce the destruction of the platelet and to increase the number of platelet, promote the differentiation and maturation of megakaryocyte, facilitate the production and release of platelet, lower the fragility of capillary, and prevent the hemorrhagic tendency.