Rectal culture could predict carbapenem-resistant organism bloodstream infection and reduce the mortality in haematological patients: A retrospective cohort study.

OBJECTIVES: The objective is to explore the correlation between rectal swab culture and the overall 30-d survival of hematologic patients diagnosed with carbapenem-resistant organism (CRO) bloodstream infection. METHODS: A total of 434 haematological patients who were complicated with Gram-negative bacilli (GNB) bloodstream infections (BSIs) caused by Gram-negative bacteria between January 2020 and December 2021 were included in our retrospective study. Based on their drug susceptibility results, we classified patients into CRO BSIs and non-CRO BSIs cases. Through group comparison, to uncover the correlation between the positive screening of rectal swabs and reducing the mortality of CRO BSI in patients with haematological diseases. RESULTS: Among the 434 cases of Gram-negative bacteria bloodstream infection, 96 were identified as carbapenem-resistant bloodstream infection, which consisted of 57 cases of carbapenem-resistant Klebsiella pneumoniae (CR-KP), 19 cases of carbapenem-resistant Pseudomonas aeruginosa (CR-PA), 11 cases of carbapenem-resistant Escherichia coli (CR-CO), 5 cases of carbapenem-resistant Acinetobacter baumannii (CR-AB), and 4 cases of other Enterobacteriaceae. Before the onset of CRO bloodstream infection, rectal swab cultures were conducted on 36 patients, and the positive result rate was 75.0% (27/36), with 20 cases of CR-KP, 6 cases of CR-CO, and one case of carbapenem-resistant Enterobacter cloacae. It was observed that the rectal and blood cultures had matching outcomes in 75.0% of cases. The mortality rate within 30 d for CRO BSIs was 53.1% (51/96), while for carbapenem-resistant Enterobacteriaceae (CRE) BSIs it was 62.5% (45/72). Univariate analysis showed that 30-d mortality was significantly reduced when there were positive rectal culture results preceding bloodstream infection (P < 0.001), as well as preemptive anti-infection treatment (P < 0.001). Multivariate analysis demonstrated that preemptive adjustment to an effective antibiotic regimen, guided by positive rectal culture results, had a significant effect on decreasing 30-d mortality following CRO BSIs (P= 0.002). Furthermore, for the management of CRE BSIs, antibiotic treatments utilising ceftazidime/avibactam (CAV/AVI) may be more beneficial compared to those that use tigecycline (TGC) or polymyxin (PMB). CONCLUSION: CRO BSI, especially CRE BSI, can be life-threatening for those with haematological diseases. Utilising rectal culture can effectively identify CRO strains with high sensitivity and specificity. Adjusting antibiotic treatment based on the preemptive positive rectal culture results may significantly decrease 30-d mortality rates for haematological patients with CRO BSIs.

Comparative analysis of hypomethylating agents as maintenance therapy after allogeneic hematopoietic stem cell transplantation for high-risk acute leukemia.

We retrospectively analyzed the outcomes of 136 consecutive patients who received allogeneic hematopoietic stem cell transplantation (allo-HSCT) at our center. Among them, 76 cases used hypomethylating agents (decitabine, n = 40; azacitidine, n = 36) as post-transplant maintenance therapy, whereas 60 contemporaneous patients did not adopt maintenance therapy. The 3-year incidences of relapse in two groups were 16.6% and 39.2% (p = .001). The 3-year OS and DFS in maintenance group were 84.0% and 78.6%, which were remarkably improved than in control group (60.0% and 58.0%) (p = .004, p = .011). Moreover, the 3-year relapse rates for patients receiving decitabine and azacitidine therapy were 8.5% and 25.0%, respectively (p = .019). Patients utilizing decitabine had more common possibility of grade 3-4 neutropenia than azacitidine (20.0% vs. 2.8%, p = .031). These results indicate that maintenance therapies using hypomethylating agents could reduce the risk of post-transplant recurrence, resulting into remarkable superior survival. Decitabine might lower relapse after allo-HSCT with somewhat more severe myelosuppression when being compared to azacitidine.

The distribution and density of monocarboxylate transporter 2 in cerebral cortex, hippocampus and cerebellum of wild-type mice.

Monocarboxylates cannot cross the blood-brain barrier freely to participate in brain energy metabolism. Specific monocarboxylate transporters (MCTs) are needed to cross cellular membranes. Monocarboxylate transporter 2 (MCT2) is a major monocarboxylate transporter encoded by the SLC16A7 gene. Recent studies reported that neurodegenerative diseases of the CNS, such as Alzheimer's disease (AD) and Parkinson's disease (PD), were related to energy metabolic impairment. MCT2 also plays an important role in energy metabolism in the CNS. To provide experimental evidence for future research on the role of MCT2 in the pathological process of CNS degenerative diseases, the distribution and density of MCT2 in different subregions of wild-type mouse brain was examined using immunohistochemistry, western blot and immunogold post-embedding electron microscopic techniques. The amount of MCT2 was higher in cerebellum than in cortex and hippocampus on western blots, and there was no statistical difference between cortex and hippocampus. Immunohistochemistry assay revealed the highest density of MCT2 in the CA3 of the hippocampus. The granular cell layer of the cerebellum contained more MCT2 than the molecular layer. The MCT2 density on the end feet of astrocytes of molecular layer was lower than in hippocampus, but the postsynaptic densities (PSDs) of asymmetric synapses in the molecular layer exhibited a high density using immunogold post-embedding electron microscopic techniques.

High power sub 100-fs Kerr-lens mode-locked Yb:YSO laser pumped by single-mode fiber laser.

We report on a Kerr-lens mode-locked Yb:YSO lasers for the first time. Pumped by a single-mode fiber laser with high brightness and linear polarization, the Yb:YSO laser can deliver as high as 2 W average power with as short as 95 fs pulse duration at the repetition rate of 137.2 MHz, resulting in the single pulse energy of 14.8 nJ and the peak power of 155.7 kW. This work proves the potential on generation of sub-100 fs pulses with multi-watt level average power with the Yb doped oxyorthosilicates crystals.

CEO stabilized frequency comb from a 1-µm Kerr-lens mode-locked bulk Yb:CYA laser.

We report the first Kerr-lens mode-locked (KLM) bulk frequency comb in the 1-µm spectral regime. The fundamental KLM Yb:CYA laser is pumped by a low-noise, high-bright 976-nm fiber laser and typically provides 250-mW output power and 57-fs pulse duration. Only 58-mW output pulses were launched into a 1.3-m photonic crystal fiber (PCF) for one octave-spanning supercontinuum generation. Using a simplified collinear f-2f interferometer, the free-running carrier-envelope offset (CEO) frequency was measured to be 42-dB signal-to-noise ratio (SNR) for a 100-kHz resolution and 9.6-kHz full width at half maximum (FWHM) under a 100-Hz resolution. A long-term CEO control at 23 MHz was ultimately realized by feeding the phase error signal to the pump power of the oscillator. The integrated phase noise (IPN) of the locked CEO was measured to be 316 mrad with an integrated range from 1 Hz to 10 MHz. The standard deviation and Allan deviation for more than 4-hour recording are 1.6 mHz and 5.6 × 10(-18) (for 1-s gate time), respectively. This is, to the best of our knowledge, the best stability achieved among the 1-µm solid-state frequency combs.

Diode-pumped Kerr-lens mode-locked Yb:LYSO laser with 61fs pulse duration.

A stable diode pumped Kerr-lens mode-locked (KLM) Yb:LuYSiO5 (Yb:LYSO) laser of generating 61 fs pulses at a central wavelength of 1055.4 nm is experimentally demonstrated. This is, to the best of our knowledge, the first demonstration of femtosecond KLM operation in Yb:LYSO laser, and it is believed that 61 fs is the shortest pulse duration ever produced from an Yb-doped orthosilicate laser. The average output power of the mode-locked laser is 40 mW and the repetition rate is 113 MHz.