[SRSF2 promotes glioblastoma cell proliferation by inducing alternative splicing of FSP1 and inhibiting ferroptosis].

Objective: To investigate the effect of serine/arginine-rich splicing factor 2 (SRSF2) on ferroptosis and its possible mechanism in glioblastoma cells. Methods: The online database of gene expression profiling interactive analysis 2 (GEPIA 2) and Chinese Glioma Genome Atlas were used to analyze the expression of SRSF2 in glioblastoma tissue and its association with patients prognosis. To validate the findings of the online databases, the pathological sections of glioblastoma and non-tumor brain tissues from Tianjin Medical University General Hospital, Tianjin, China were collected and analyzed by using immunohistochemistry. Silencing SRSF2 gene expression in glioblastoma cells by siRNA was analyzed with Western blot. The proliferation index was detected by using CCK8 assay. The rescued experiment was conducted by using expression plasmid of pcDNA3.1(+)-SRSF2. The activity of ferroptosis was assessed by using the levels of iron ions and malondialdehyde in glioblastoma cells and the changes in the ratio of glutathione to oxidized glutathione. The changes of gene expression and differential pre-mRNA alternative splicing (PMAS) induced by SRSF2 were monitored by using the third-generation sequencing technology analysis, namely Oxford nanopore technologies (ONT) sequencing analysis. Results: SRSF2 expression was higher in glioblastoma tissues than non-tumor brain tissues. Immunohistochemistry also showed a positive rate of 88.48%±4.60% in glioblastoma tissue which was much higher than the 9.97%±4.57% in non-tumor brain tissue. The expression of SRSF2 was inversely correlated with overall and disease-free disease survivals (P<0.01). The proliferation index of glioblastoma cells was significantly reduced by silencing with SRSF2 siRNA (P<0.01) and could be reversed with transfection of exogenous SRSF2. The levels of intracellulariron ions and malondialdehyde increased (P<0.05), but the glutathione/oxidized glutathione ratio and the expression of key proteins in the glutathione pathway remained unchanged (P>0.05). ONT sequencing results showed that silencing SRSF2 in glioblastoma cells could induce a significant alternative 3' splice site change on ferroptosis suppressor protein 1 (FSP1). Conclusion: SRSF2 inhibits the ferroptosis in glioblastoma cells and promotes their proliferation, which may be achieved by regulating FSP1 PMAS.

[Attention should be paid to the differentiationbetween benign paroxysmal positional vertigo and vestibular migraine].

As we know, benign paroxysmal positional vertigo is a peripheral vestibular disorder,while vestibular migraine is a central vestibular disease. Although they are two different independent diseases, patients often choose to consult otolaryngology and neurology. The clinical manifestations of some patients with these two diseases are similar and the diagnosis is easy to be confused, but the treatment methods are completely different, and incorrect treatment methods will inevitably affect the curative effect and prognosis. Vestibular migraine is characterized by a diversity of clinical manifestations and signs, and the migraine symptoms of some patients do not match with the vestibular symptoms. There are 30% of vestibular migraine patients who showed isolated paroxysmal vertigo/dizziness and nystagmus, which is easily confused with benign paroxysmal positional vertigo and needs to be identified. Under the framework of the international classification of vestibular diseases, according to the new guideline of nystagmus examination and classification issued by Barany Association and new diagnostic criteria of two diseases, differential diagnosisof benign paroxysmal positional vertigo from vestibular migrainecan make up for one-sided understanding caused by the specialization of disciplines, improve thediagnosis and treatment of vestibular diseases, and thus reduce the misdiagnosis and mistreatment.

Fecal calprotectin and fecal indole predict outcome of fecal microbiota transplantation in subjects with recurrent Clostridium difficile infection.

Fecal calprotectin and indole were studied in 134 subjects with recurrent CDI before and after FMT. Reduced fecal calprotectin (p = 0.0353, 95% CI 0.1305-0.1439) and rising levels of indole (p < 0.0001, 95% CI < 0.0001-0.0003) predicted successful treatment. A ratio of recal calprotectin/indole may provide prognostic value for FMT (p = 0.0004, 95% CI 0.22-0.87).

[Etiological analysis on patients with vertigo or dizziness].

Objective: To explore the spectrum of causes for patients with vertigo or dizziness in the Department of Neurology, and provide a reference for diagnosis and treatment of patients with vertigo or dizziness. Methods: Clinical data of patients in the Department of Neurology, Baotou Central Hospital between January 2016 and September 2017 was retrospectively analyzed. The target group under study was diagnosed based on the uniform diagnostic criteria. Results: A total of 9 200 patients with a chief complaint of vertigo or dizziness were included. The ratio of male to female was 1∶1.8, with an age range of 19 to 85 years. The different etiology was as follows: benign paroxysmal positional vertigo (BPPV) (3 148 cases, 34.22%), persistent postural-perceptual dizziness (PPPD) (2 006 cases, 21.80%), vertigo caused by cerebrovascular diseases (1 463 cases, 15.90%), vestibular neuritis (741 cases, 8.05%), vestibular migraine (536 cases, 5.83%), vestibular paroxysmia (336 cases, 3.65%), Ménière disease (187 cases, 2.03%), drug-induced vertigo (96 cases, 1.04%), neurological degenerative diseases (74 cases, 0.80%), sudden sensorineural hearing loss (51 cases, 0.55%), multiple sclerosis and neuromyelitis optica (21 cases, 0.23%), other reasons (22 cases, 0.24%), unknown reasons (519 cases, 5.64%). Conclusions: Dizziness is resulted from various causes, and BPPV is the most common reason. Vertigo caused by cerebrovascular diseases appears to gradually increase along with age. PPPD is very common in clinical practice, so clinicians needs to be highly aware of BPPV and PPPD. Although those dizziness diseases have a low incidence, they should not be ignored. There are still certain proportion of vertigo patients whose diagnosis are undetermined.

Etiology of travellers' diarrhea.

Eleven published studies of the etiology of travellers' diarrhea (TD) were reviewed define the etiology of TD and to exam newly developed technology such as Real-Time multiplex polymerase chain reaction (PCR) to identify multiple pathogens in one assay to define the cause of TD. Using PCR methods bacterial pathogens were found in 72% of patients acquiring diarrhea in Latin America and in 80% in travellers with illness acquired in Southeast Asia). In these studies, enterotoxigenic Escherichia coli as the predominant pathogen (42% in Latin America and 28% in Southeast Asia). Ciprofloxacin-resistant Campylobacter was commonly associated with TD in Southeast Asia. Multiplex PCR has improved the detection of enteropathogens and allowed better assessment returning travellers hospitalized with TD and those with persistent diarrhea.

Randomised clinical trial: faecal microbiota transplantation for recurrent Clostridum difficile infection - fresh, or frozen, or lyophilised microbiota from a small pool of healthy donors delivered by colonoscopy.

BACKGROUND: Faecal microbiota transplantation (FMT) has become routine in managing recurrent C. difficile infection (CDI) refractory to antibiotics. AIM: To compare clinical response and improvements in colonic microbiota diversity in subjects with recurrent CDI using different donor product. METHODS: Seventy-two subjects with ≥3 bouts of CDI were randomised in a double-blind study to receive fresh, frozen or lyophilised FMT product via colonoscopy from 50 g of stool per treatment from eight healthy donors. Recipients provided stools pre- and 7, 14 and 30 days post-FMT for C. difficile toxin and, in a subset, microbiome composition by 16S rRNA gene profiling. RESULTS: Overall resolution of CDI was 87% during 2 months of follow-up after FMT. Stool samples before FMT had significantly decreased bacterial diversity with a high proportion of Proteobacteria compared to donors. Cure rates were highest for the group receiving fresh product seen in 25/25 (100%), lowest for the lyophilised product 16/23 (78%; P = 0.022 vs. fresh and 0.255 vs. frozen) and intermediate for frozen product 20/24 (P = 0.233 vs. fresh). Microbial diversity was reconstituted by day 7 in the subjects receiving fresh or frozen product. Improvement in diversity was seen by day 7 in those randomised to lyophilised material with reconstitution by 30 days. CONCLUSIONS: Comparative efficacy in faecal microbiota transplantation was observed in subjects receiving fresh or frozen faecal product from the same donors. The lyophilised product had a slightly lowered efficacy compared with fresh product, but it resembled other treatments in microbial restoration 1 month after faecal microbiota transplantation.

Measurement of Thermal Conductivity of Porcine Liver in the Temperature Range of Cryotherapy and Hyperthermia (250~315k) by A Thermal Sensor Made of A Micron-Scale Enameled Copper Wire.

　　BACKGROUND: Cryotherapy and hyperthermia are effective treatments for several diseases, especially for liver cancers. Thermal conductivity is a significant thermal property for the prediction and guidance of surgical procedure. However, the thermal conductivities of organs and tissues, especially over the temperature range of both cryotherapy and hyperthermia are scarce. OBJECTIVE: To provide comprehensive thermal conductivity of liver for both cryotherapy and hyperthermia. MATERIALS AND METHODS: A hot probe made of stain steel needle and micron-sized copper wire is used for measurement. To verify data processing, both the least square method and the Monte Carlo inversion method are used to determine the hot probe constants, respectively, with reference materials of water and 29.9 % Ca2Cl aqueous solution. Then the thermal conductivities of Hanks solution and pork liver bathed in Hanks solution are measured. RESULTS: The effective length for two methods is nearly the same, but the heat capacity of probe calibrated by the Monte Carlo inversion is temperature dependent. Fairly comprehensive thermal conductivity of porcine liver measured with these two methods in the target temperature range is verified to be similar. CONCLUSION: We provide an integrated thermal conductivity of liver for cryotherapy and hyperthermia in two methods, and make more accurate predictions possible for surgery. The least square method and the Monte Carlo inversion method have their advantages and disadvantages. The least square method is available for measurement of liquids that not prone to convection or solids in a wide temperature range, while the Monte Carlo inversion method is available for accurate and rapid measurement.

DETERMINATION OF CONVECTIVE HEAT TRANSFER COEFFICIENT AT THE OUTER SURFACE OF A CRYOVIAL BEING PLUNGED INTO LIQUID NITROGEN.

BACKGROUND: Cell survival upon cryopreservation is affected by the cooling rate. However, it is difficult to model the heat transfer process or to predict the cooling curve of a cryoprotective agent (CPA) solution due to the uncertainty of its convective heat transfer coefficient (h). OBJECTIVE: To measure the h and to better understand the heat transfer process of cryovials filled with CPA solution being plunged in liquid nitrogen. MATERIALS AND METHODS: The temperatures at three locations of the CPA solution in a cryovial were measured. Different h values were selected after the cooling process was modeled as natural convection heat transfer, the film boiling and the nucleate boiling, respectively. And the temperatures of the selected points are simulated based on the selected h values. h was determined when the simulated temperature best fitted the experimental temperature. RESULTS: When the experimental results were best fitted, according to natural convection heat transfer model, h(1) = 120 W/(m(2)·K) while due to film boiling and nucleate boiling regimes h(f) = 5 W/(m(2)·K) followed by h(n) = 245 W/(m(2)·K). These values were verified by the differential cooling rates at the three locations of a cryovial. CONCLUSION: The heat transfer process during cooling in liquid nitrogen is better modeled as film boiling followed by nucleate boiling.

Mild maturational delay of the brainstem at term in late preterm small-for-gestation age babies.

AIMS: To detect any functional abnormality in the brainstem auditory pathway in late preterm babies born of small-for-gestational age (SGA) using maximum length sequence brainstem evoked response. STUDY DESIGN: The response was recorded and analyzed at term in 38 SGA (birthweight <3rd centile) babies born at 33-36 week gestation. The results were compared with 40 age-matched babies born of appropriate-for-gestational age (AGA) (birthweight >10th centile). None of the subjects had major perinatal problems. RESULTS: All wave latencies and interpeak intervals in the SGA group were slightly longer than those in the AGA group at most click rates. Wave III latency was significantly longer than that in the AGA group at 227/s (P < 0.05), and wave V latency was at 227 and 910/s (P < 0.05 and 0.05). Of the interpeak intervals, only the I-V interval in the SGA group was significantly longer than that in the AGA group at the highest rate 910/s (P < 0.05). The amplitudes of waves I, III and V in the SGA group all tended to be smaller than those in the AGA group at all click rates 91-910/s. The wave V amplitude was significantly smaller at most click rates (227-910/s, all P < 0.05). The slopes of all wave latency-, interval-, and amplitude-rate functions were similar in SGA and AGA groups. CONCLUSIONS: There were marginal abnormalities in MLS BAER of low-risk late preterm SGA babies, suggesting a mild degree of maturational delay in the brainstem. Intrauterine growth retardation occurring in late preterm babies has a minor effect on neural maturation of the immature brainstem.

Clostridium difficile infection in hospitalized cancer patients in Beijing, China is facilitated by receipt of cancer chemotherapy.

The purpose of this study was to determine the presence of Clostridium difficile infection (CDI) and risk factors for infection in hospitalized patients with diarrhea in a cancer hospital in Beijing, China. A total of 277 patients with hospital-associated diarrhea (HAD) were studied of which 41 (15%) were positive for fecal C. difficile toxin A/B. For each CDI case identified, a control with HAD but negative C. difficile specimen was enrolled to look for CDI risk factors. Receipt of cancer chemotherapy occurred in 20 (49%) patients with CDI and 9 (22.0%) patients with non-CDI HAD (OR3.39, 95%CI 1.78-10.05). Median length of chemotherapy before HAD developed was 39 days for those with CDI and 22 days for patients with CDI-negative HAD (P = 0.0391). The study found that CDI is commonly seen in cancer patients in China with increasing risk for patients who receive chemotherapy.

First Report of Brown Spot Disease Caused by Neoscytalidium dimidiatum on Hylocereus undatus in Guangdong, Chinese Mainland.

Pitahaya or dragon fruit [Hylocereus undatus (Haw.) Britton & Rose] is one of the most popular tropical fruits in the world. In China, it is widely planted in Guangdong, Guangxi, Hainan, and Taiwan. In July 2011, a new pitahaya disease was found in Conghua City and Yunfu City, Guangdong Province, China, characterized by many small, circular, reddish brown spots over the diseased stems. The spots continuously expanded, and ultimately formed large areas of canker on stems. It is similar to pitahaya stem canker disease caused by Neoscytalidium dimidiatum in Taiwan (1). Pieces of tissues were collected from the lesion margins. After surface disinfestations with 1% sodium hypochloride for 1 min and rinsing in sterile water three times, the diseased tissues were placed on potato dextrose agar medium plates (PDA) and incubated at 28°C for 3 days. A dark, fast-growing fungus was isolated from all samples. For identification, single-spore cultures were grown on PDA in an incubator at 28°C. After 5 days, colonies with dark gray to black aerial mycelium formed. The colonies produced abundant conidia that occurred in arthric chains in aerial mycelium. The conidia were disarticulating, cylindrical-truncate, oblong-obtuse to doliform, dark brown, zero- to one-septate, and averaged 7.56 (5.46 to 10.30) × 6.20 (3.79 to 8.93) µm. The teleomorph was never observed in PDA culture. Based on these characteristics, the fungus was identified as N. dimidiatum (Penz.) Crous & Slippers (2). The internal transcribed spacer (ITS) regions of rDNAs from two isolates were amplified by primers ITS1 and ITS4 (3), and then sequenced. Both sequences were completely identical and 579 bp long (GenBank Accession Nos. JX128103 and JX128104), with 99% identity to that of N. dimidiatum previously deposited (Accession No. HQ439174). To confirm its pathogenicity, six healthy detached stems of pitahaya designed as two replicates were inoculated by injecting 10 µl of conidia suspension (1 × 106 conidia per ml). Three stems were inoculated with sterile water as controls. The inoculated stems were kept in an incubator at 28°C in dark. The stems exhibited the same symptoms as described above after 10 days post inoculation, whereas no symptoms developed on the control stems. The fungus was reisolated from the lesions of the inoculated stem. These results indicated that N. dimidiatum was the pathogen of pitahaya brown spot disease. To our knowledge, this is the first report of brown spot caused by N. dimidiatum on H. undatus on the Chinese mainland. References: (1) M. F. Chuang et al. Plant Dis. 96:906, 2012. (2) P. W. Crous et al. Stud. Mycol. 55:235, 2006. (3) T. J. White et al. Page 315 in: PCR Protocols: A Guide to Methods and Applications. M. A. Innis et al., eds. Academic Press, New York, 1990.

Characterization of norovirus-associated traveler's diarrhea.

BACKGROUND: Traveler's diarrhea is the most common medical complaint of international visitors to developing regions. Previous findings suggested that noroviruses (NoVs) are an underappreciated cause of traveler's diarrhea. METHODS. In the present study, we sought to define the presence of NoVs in 320 acute diarrheic stool samples collected from 299 US students who traveled to Guadalajara, Cuernavaca, or Puerto Vallarta, Mexico, during the period from 2007 through 2008. Conventional and quantitative real-time polymerase chain reaction assays were used to detect and determine NoV loads in stool samples. NoV strains were characterized by purification of viral RNA followed by sequencing of the viral capsid protein 1 gene. Sequences were compared using multiple sequence alignment, and phylogenetic trees were generated to evaluate the evolutionary relatedness of the viral strains associated with cases of traveler's diarrhea. RESULTS: NoV RNA was detected in 30 (9.4%) of 320 samples. Twelve strains belonged to genogroup I, and 18 strains belonged to genogroup II. NoV prevalence was higher in the winter season than in the summer season (23% vs 7%, respectively; P = .001). The cDNA viral loads of genogroup I viruses were found to be 500-fold higher than those of genogroup II strains. Phylogenetic analysis revealed a diverse population of NoV strains over different locations and years. CONCLUSIONS: NoV strains are important causes of traveler's diarrhea in Mexico, especially during the wintertime, and US students in Mexico may represent a suitable group for future NoV vaccine efficacy trials.

In vitro susceptibility of Clostridium difficile to rifaximin and rifampin in 359 consecutive isolates at a university hospital in Houston, Texas.

AIM: This was an in vitro study to analyse the susceptibility of Clostridium difficile isolates to rifampin and rifaximin. METHODS: Stool samples from patients who had nosocomial diarrhoea and C difficile toxin B at a university hospital between August 2006 and December 2007 were cultured for C difficile. Susceptibility of C difficile isolates to rifaximin and rifampin was determined by agar dilution and E strips, respectively. C difficile isolates were analysed via PCR for genes encoding toxins A and B, for binary toxin (BT), and for partial deletions of the tcdC gene (tcdC-del). RESULTS: Rifaximin exhibited high-level activity against 359 C difficile isolates, with MIC(50) <0.01 microg/ml and MIC(90) 0.25 microg/ml; rifampin had MIC(50) <0.002 microg/ml and MIC(90) 4 microg/ml. Among isolates analysed, 55 (15%) were positive for BT and tcdC-del. 28 (8% of 359) isolates were resistant to rifampin (> or = 32 microg/ml), of which 6 (2% of 359) were resistant to rifaximin and rifampin with MIC values > or = 32 microg/ml. 2 of the 28 isolates resistant to rifampin were A(+)/B(+)/BT(+)/tcdC-del(+), 5 were A(+)/B(+)/BT(-)/tcdC-del(+), 4 were A(+)/B(+)/BT(+)/tcdC-del(-), 13 were A(+)/B(+)/BT(-)/tcdC-del(-), and 4 had no detectable toxin genes. Of the 11 isolates resistant to rifaximin alone, 1 was A(+)/B(+)/BT(-)/tcdC-del(+), 2 were A(+)/B(+)/BT(+)/tcdC-del(-), 6 were A(+)/B(+)/BT(-)/tcdC-del(-), and 2 had no detectable toxin genes. CONCLUSIONS: The study demonstrates that rifaximin has high-level activity against C difficile in vitro. Determination of resistance to rifampin by E strip did not predict rifaximin resistance.

A clinical risk index for Clostridium difficile infection in hospitalised patients receiving broad-spectrum antibiotics.

Identification of a population at high risk for Clostridium difficile infection (CDI) would enable CDI prevention strategies to be designed. The purpose of this study was to create a clinical risk index that would predict those at risk for CDI. A CDI risk index was therefore developed, based on a cohort of hospital patients given broad-spectrum antibiotics, and divided into a development and validation cohort. Logistic regression equations helped identify significant predictors of CDI. A scoring algorithm for CDI risk was created using identified risk factors and collapsed to create four categories of CDI risk. The area under the receiver operating characteristic (aROC) curve was used to measure goodness-of-fit. Among 54 226 patients, 392 tested positive for C. difficile. Age 50-80 years [odds ratio (OR: 0.5; P<0.0116)], age >80 years (OR: 2.5; P<0.0001), haemodialysis (OR: 1.5; P=0.0227), non-surgical admission (OR: 2.2; P<0.0001) and increasing length of stay in the intensive care unit (OR: 2.1; P<0.0001) were significantly associated with CDI. A simple risk index using presence of significant variables was significantly associated with increasing risk for CDI in both development (OR: 3.57; P<0.001; aROC: 0.733) and validation (OR: 3.31; P<0.001; aROC: 0.712) cohorts. An OR-derived risk index did not perform as well as the simple risk index. This easily implemented risk index should allow stratification of patients into risk group categories for development of CDI and help fashion preventive strategies.

Rifaximin: in vitro and in vivo antibacterial activity--a review.

In vitro inhibitory activity of rifaximin is directed against Gram-positive and Gram-negative, aerobic and anaerobic bacteria. It is effective in the treatment of gastrointestinal infections when given orally because of the high concentration of the drug remaining in the gut lumen. Laboratory investigations have been carried out to assess the in vitro activity of rifaximin on different bacterial strains isolated from both human and domestic animals. The objective of this project is to review the in vitro and in vivo activity of rifaximin against bacterial infection with Gram-negative rods, Gram-positive rods and Gram-positive cocci and their resistance to rifaximin. The available data suggest that rifaximin is active in vitro and in vivo in the treatment of bacterial infection of adults and children.