[A case of fungal keratitis caused by Petriella setifera infection]

The patient, a 66-year-old male, suffered from redness, blurred vision, photophobia, and tearing in the right eye after being injured by a wooden board. Anti-inflammatory treatment showed poor effectiveness. A 4 mm × 4 mm infiltrate with white deposits on the surface was observed in the central cornea of the right eye. Microscopic examination of corneal scrapings, fungal culture, and in vivo confocal microscopy all indicated fungal infection. The isolated strain was identified as Scedosporium apiospermum through microscopic morphology and confirmed as Petriella setifera by gene sequencing. The patient received corneal debridement combined with routine anti-inflammatory and antifungal treatment in the outpatient clinic. During the follow-up period, the condition continued to improve. Slit lamp examination at the revisit 40 days after the initial diagnosis revealed thinning of the corneal stroma, basic healing of the epithelium, and an increase in uncorrected visual acuity from 0.3 to 0.6.

[A single-center study on the distribution and antibiotic resistance of pathogens causing bloodstream infection in patients with hematological malignancies]

Objective: To study the incidence of bloodstream infections, pathogen distribution, and antibiotic resistance profile in patients with hematological malignancies. Methods: From January 2018 to December 2021, we retrospectively analyzed the clinical characteristics, pathogen distribution, and antibiotic resistance profiles of patients with malignant hematological diseases and bloodstream infections in the Department of Hematology, Nanfang Hospital, Southern Medical University. Results: A total of 582 incidences of bloodstream infections occurred in 22,717 inpatients. From 2018 to 2021, the incidence rates of bloodstream infections were 2.79%, 2.99%, 2.79%, and 2.02%, respectively. Five hundred ninety-nine types of bacteria were recovered from blood cultures, with 487 (81.3%) gram-negative bacteria, such as Klebsiella pneumonia, Escherichia coli, and Pseudomonas aeruginosa. Eighty-one (13.5%) were gram-positive bacteria, primarily Staphylococcus aureus, Staphylococcus epidermidis, and Enterococcus faecium, whereas the remaining 31 (5.2%) were fungi. Enterobacteriaceae resistance to carbapenems, piperacillin/tazobactam, cefoperazone sodium/sulbactam, and tigecycline were 11.0%, 15.3%, 15.4%, and 3.3%, with a descending trend year on year. Non-fermenters tolerated piperacillin/tazobactam, cefoperazone sodium/sulbactam, and quinolones at 29.6%, 13.3%, and 21.7%, respectively. However, only two gram-positive bacteria isolates were shown to be resistant to glycopeptide antibiotics. Conclusions: Bloodstream pathogens in hematological malignancies were broadly dispersed, most of which were gram-negative bacteria. Antibiotic resistance rates vary greatly between species. Our research serves as a valuable resource for the selection of empirical antibiotics.

[Establishment and validation of clinical prediction model for steroid-resistant nephrotic syndrome in children]

Objective: To identify the clinically relevant factors of steroid-resistant nephrotic syndrome (SSNS) in children and establish a predictive model followed by verifying its feasibility. Methods: A retrospective analysis was performed in a total of 111 children with nephrotic syndrome admitted to Children's Hospital of ShanXi from January 2016 to December 2021. The clinical data of general conditions, manifestations, laboratory tests, treatment, and prognosis were collected. According to the steroid response, patients were divided into SSNS and steroid resistant nephrotic syndrome (SRNS) group. Single factor Logistic regression analysis was used for comparison between the 2 groups, and variables with statistically significant differences were included in multivariate Logistic regression analysis. The multivariate Logistic regression analysis was used to identify the related variables of children with SRNS. The area under the receiver operating characteristic curve (ROC), the calibration curve and the clinical decision curve were used to evaluate its effectiveness of the variables. Results: Totally 111 children with nephrotic syndrome was composed of 66 boys and 45 girls, aged 3.2 (2.0, 6.6) years. There were 65 patients in the SSNS group and 46 in the SRNS group.Univariate Logistic regression analysis showed that the 6 variables, including erythrocyte sedimentation rate, 25-hydroxyvitamin D, suppressor T cells, D-dimer, fibrin degradation products, β2-microglobulin, had statistically significant differences between SSNS and SRNS groups (85 (52, 104) vs. 105 (85, 120) mm/1 h, 18 (12, 39) vs. 16 (12, 25) nmol/L, 0.23 (0.19, 0.27) vs. 0.25 (0.20, 0.31), 0.7 (0.6, 1.1) vs. 1.1 (0.9, 1.7) g/L, 3.1 (2.3, 4.1) vs. 3.3 (2.7, 5.8) g/L, 2.3 (1.9,2.8) vs. 3.0 (2.5, 3.7) g/L, χ²=3.73, -2.42, 2.24, 3.38, 2.24,3.93,all P<0.05), were included in the multivariate Logistic regression analysis. Finally, we found that 4 variables including erythrocyte sedimentation rate, suppressor T cells, D-dimer and β2-microglobulin (OR=1.02, 1.12, 25.61, 3.38, 95%CI 1.00-1.04, 1.03-1.22, 1.92-341.04, 1.65-6.94, all P<0.05) had significant correlation with SRNS. The optimal prediction model was selected. The ROC curve cut-off=0.38, with the sensitivity of 0.83, the specificity of 0.77 and area under curve of 0.87. The calibration curve showed that the predicted probability of SRNS group occurrence was in good agreement with the actual occurrence probability, χ²=9.12, P=0.426. The clinical decision curve showed good clinical applicability. The net benefit is up to 0.2. Make the nomogram. Conclusions: The prediction model based on the 4 identified risk factors including erythrocyte sedimentation rate, suppressor T cells, D-dimer and β2-microglobulin was suitable for the early diagnosis and prediction of SRNS in children. The prediction effect was promising in clinical application.

[A case of microsporidial keratitis]

A case of keratitis caused by microsporidia infection was reported. A 57-year-old female patient, without any obvious predisposing cause, presented with eye redness, eye abrasion and vision loss for one year in the left eye. The patient was diagnosed with viral keratitis based on laboratory examinations and clinical symptoms two months ago in our hospital. He was given outpatient treatment for antivirus. Two months later, he was admitted to our hospital with worsened condition that presented with corneal ulcer. After admission, corneal scraping examination was performed for the detection of microsporidia with calcofluor white (CFW) and Ziehl-Neelsen staining, the smear revealed multiple oval spore-like structures, with acid-fast positive and showed blue fluorescence on potassium hydroxide with CFW stain, confirming a diagnosis of microsporidial keratitis in the left eye. Treatment: topical use of ofloxacin eye ointment and voriconazole eye drops was not effective, and then penetrating keratoplasty was performed, and the patient's condition was stable after surgery. At present, they are still in treatment and follow-up.

[Current status and prospect of treatment for esophageal cancer in the era of precision medicine]

Esophageal cancer (EC) is one of the most common malignant tumors around the world and has a high incidence in China. Chinese EC patients account for more than 50% in the world. The pathological subtype of EC shows a geographic distribution. Adenocarcinoma is the main pathological type in western countries, while squamous cell carcinoma is the dominant subtype in China. Thus specific diagnosis and treatment of EC are needed for Chinese patients. Although early diagnosis, progress in surgery and comprehensive treatment of EC have made remarkable achievements in China in recent years, yet the prognosis for resectable EC patients remains poor, with a 5-year survival of 30%. In addition, as the level of treatment varies significantly in different regions and centers around China, the current status of treatment for EC needs further improvement. This article reviews the advances in the treatment for EC in recent years, analyzes the present problems, and explores the perspective of the progress in esophageal cancer treatment in the era of precision medicine.

Kinetic basis for insensitivity to tetrodotoxin and saxitoxin in sodium channels of canine heart and denervated rat skeletal muscle

The single-channel blocking kinetics of tetrodotoxin (TTX), saxitoxin (STX), and several STX derivatives were measured for various Na-channel subtypes incorporated into planar lipid bilayers in the presence of batrachotoxin. The subtypes studied include Na channels from rat skeletal muscle and rat brain, which have high affinity for TTX/STX, and Na channels from denervated rat skeletal muscle and canine heart, which have about 20-60-fold lower affinity for these toxins at 22 degrees C. The equilibrium dissociation constant of toxin binding is an exponential function of voltage (e-fold per 40 mV) in the range of -60 to +60 mV. This voltage dependence is similar for all channel subtypes and toxins, indicating that this property is a conserved feature of channel function for batrachotoxin-activated channels. The decrease in binding affinity for TTX and STX in low-affinity subtypes is due to a 3-9-fold decrease in the association rate constant and a 4-8-fold increase in the dissociation rate constant. For a series of STX derivatives, the association rate constant for toxin binding is approximately an exponential function of net toxin charge in membranes of neutral lipids, implying that there is a negative surface potential due to fixed negative charges in the vicinity of the toxin receptor. The magnitude of this surface potential (-35 to -43 mV at 0.2 M NaCl) is similar for both high- and low-affinity subtypes, suggesting that the lower association rate of toxin binding to toxin-insensitive subtypes is not due to decreased surface charge but rather to a slower protein conformational step. The increased rates of toxin dissociation from insensitive subtypes can be attributed to the loss of a few specific bonding interactions in the binding site such as loss of a hydrogen bond with the N-1 hydroxyl group of neosaxitoxin, which contributes about 1 kcal/mol of intrinsic binding energy.