[Clinical characteristics and prognosis of MLL-AF6 positive patients with acute myeloid leukemia]

OBJECTIVE

To investigate the clinical features and prognosis of acute myeloid leukemia (AML) patients with the mixed lineage leukemia (MLL) gene rearrangements AF6 (MLL-AF6) positive.

METHODS

In the study, 11 patients who were newly diagnosed with MLL-AF6 positive AML were analyzed retrospectively, related literature was reviewed to clarify the clinical features and prognosis of MLL-AF6 positive patients.

RESULTS

Among the 11 patients, there were 6 males and 5 females, with a median age of 36 years. Six patients were diagnosed with AML M5 and five with M4 according to FAB classification (French-American-British classification systems). Gingival swelling and pain occurred in 6 cases and fever occurred in 5 cases. At first diagnosis, the median white blood cells were 55.5×109/L. Immunotype showed the expression of myeloid/monocyte and early stem cell series antigens. The expression level of MLL-AF6 fusion gene (real-time quantitative PCR) was 14.2%-214.5%, and 6/11 cases (54.5%) were associated with high EVI1 gene expression. Mutations of KRAS, TET2, ASXL1, TP53, DNMT3A, and FLT3-ITD were detected by next generation sequencing (NGS) in 4 patients. Chromosome G banding examination showed that 2 cases were t(6;11)(q27, q23) with complex karyotype abnormality, 4 cases with +8 abnormality and 2 cases with normal karyotype. Hematological complete remission (CR) was achieved in 8/11 patients (72.7%) after conventional induction chemotherapy, and primary drug resistance was observed in 3 patients. Two of the eight patients with CR were negative for minimal residual disease (MRD), with a median CR duration of 4.5 months. Two patients with positive MRD and three patients with refractory recurrence underwent allogeneic hematopoietic stem cell transplantation (allo-HSCT), but all died due to leukemia progression. At the end of follow-up on December 1, 2019, 2 patients were alive and 9 died, with median survival time of 9 months.

CONCLUSION

The AML patients with MLL-AF6 positive were mostly young, the majority of FAB types were M4 and M5, and most of the patients often had fever as the first symptom, with increased white blood cells, accompanied by organ infiltration, and high EVI1 gene expression. The hematological remission rate of routine chemotherapy is not low, but it is difficult to achieve molecular remission, most of which have early recurrence. Early allo-HSCT in a molecular negative state may prolong the CR duration.

Preparation and Properties of Polyaminosiloxane Modified Polyester Waterborne Polyurethane

In this study, a organosilicon modified waterborne polyurethane (WPU) is synthesized with polyethylene glycol 1,4-butanediol adipate ester diol (PBA) to form the soft segment, dimethylolpropionic acid (DMPA) as the hydrophilic chain extender, and isophorone diisocyanate as the hard segment to synthesize the WPU prepolymer, and aminoethyl aminopropyl dimethicone (AEAPS) as the graft chain extender. The properties of the formed WPU films are then characterized by using Fourier transform infrared spectrometry, thermogravimetric analysis, X-ray diffraction, and dynamic mechanical analysis. It is found that when the amount of AEAPS in the WPU is increased from 0 to 30 wt%, the particle size of the AEAPS modified WPU emulsion is increased from 84.8 nm to 271.9 nm and maintained high centrifugal stability. Moreover, the water absorption of the WPU film is reduced from 43.4% to 24.1%, and the hardness is enhanced from 3H to 5H, while the glass-transition temperature (Tg) of the soft segment of the modified WPU shifts from -37.4 °C to -44.3 °C, and the Tg of the hard segment shifts from 73.6 °C to 118.1 °C. Therefore, the overall performance of AEAPS modified WPU is improved.

[Current applications of artificial intelligence in tumor histopathology]

The tasks of artificial intelligence (AI) in tumor histopathology include image segmentation and classification. Currently, the specific contents including lymph node metastasis, pathological classification, grade and prognostic evaluation of malignant diseases, such as breast cancer, lung cancer and prostate cancer, have been studied by AI. Evaluation of sentinel lymph node metastasis of breast cancer has been the most mature application of AI technology, whose level can be analogous to the excellent pathologists. In the future, with the close cooperation of pathologists and engineers, the research of AI will be focus on improving the technology of simple and repetitive clinical diagnosis and differential diagnosis, such as the diagnosis of sentinel lymph node metastasis of breast cancer from biopsy frozen section and the judgment of incisal margin. Ultimately, AI will help us to precisely diagnose the tumor.

Fetuin A is down-regulated in rats during heterotopic ossification after Achilles tenotomy

We investigated the role of fetuin A during heterotopic ossification (HO) in rats following Achilles tenotomy. We performed a right midpoint Achilles tenotomy on 24 rats. At 5 and 10 h after surgery, we investigated the formation of ectopic bone using X-ray and histological examination. We evaluated the mRNA level of fetuin A using real-time PCR. Presence of fetuin A in the Achilles tendon was assessed by immunohistochemical staining. We also measured the serum concentration of fetuin A using enzyme linked immunosorbent assay (ELISA). The expression of fetuin A was significantly decreased in both the liver and Achilles tendon during HO. ELISA showed a small amount of fetuin A in blood throughout the development of HO. Immunohistochemical staining showed that fetuin A was abundant in the ectopic bone. Fetuin A appears to be involved in the formation of ectopic bone induced by Achilles tenotomy, and a deficiency of fetuin A plays a role in the development of HO.

The new P2Y-like receptor G protein-coupled receptor 17 mediates acute neuronal injury and late microgliosis after focal cerebral ischemia in rats

G protein-coupled receptor 17 (GPR17), the new P2Y-like receptor, is phylogenetically related to the P2Y and cysteinyl leukotriene receptors, and responds to both uracil nucleotides and cysteinyl leukotrienes. GPR17 has been proposed to be a damage sensor in ischemic stroke; however, its role in brain inflammation needs further detailed investigation. Here, we extended previous studies on the spatiotemporal profiles of GPR17 expression and localization, and their implications for brain injury after focal cerebral ischemia. We found that in the ischemic core, GPR17 mRNA and protein levels were upregulated at both 12-24 h and 7-14 days, but in the boundary zone the levels increased 7-14 days after reperfusion. The spatiotemporal pattern of GPR17 expression well matched the acute and late (subacute/chronic) responses in the ischemic brain. According to previous findings, in the acute phase, after ischemia (24 h), upregulated GPR17 was localized in injured neurons in the ischemic core and in a few microglia in the ischemic core and boundary zone. In the late phase (14 days), it was localized in microglia, especially in activated (ED1-positive) microglia in the ischemic core, but weakly in most microglia in the boundary zone. No GPR17 was detectable in astrocytes. GPR17 knockdown by a small interfering RNA attenuated the neurological dysfunction, infarction, and neuron loss at 24 h, and brain atrophy, neuron loss, and microglial activation at 14 days after reperfusion. Thus, GPR17 might mediate acute neuronal injury and late microgliosis after focal cerebral ischemia.

Modification of central nervous system effects of laudanosine by inhalation anaesthetics

To determine the effect of inhalation anaesthetics on the plasma concentration of laudanosine necessary to produce CNS excitation, we administered laudanosine 0.5 mg kg-1 min-1 i.v. to 40 rabbits under eight study conditions: 1.0 or 0.7% halothane, 1.6% isoflurane, 2.0% enflurane, during normocapnia and hypocapnia; 70% nitrous oxide, alone and with 1.0% halothane, and room air (control). At the onset of purposeless, unco-ordinated movements of the entire body, blood samples were obtained to determine the CNS excitation-threshold plasma concentration (ETPC) of laudanosine. During normocapnia, 1.0% halothane, 1.6% isoflurane and 2.0% enflurane increased ETPC (mean (SD) 11.8 (2.5), 11.3 (2.8) and 9.1 (1.4) micrograms ml-1, respectively) from control (5.0 (0.9) microgram ml-1). ETPC during enflurane anaesthesia did not change significantly with hypocapnia. Nitrous oxide, alone or in combination with halothane, did not change ETPC. The combination of nitrous oxide with 1.0% halothane significantly decreased ETPC to less than that for halothane alone (6.7 (1.2) v. 11.8 (2.5) micrograms ml-1, respectively).

Pharmacology of laudanosine in dogs

The authors determined the pharmacokinetics (including transfer into cerebrospinal fluid [CSF]) and the cardiovascular and central nervous system (CNS) effects of laudanosine, a metabolite of atracurium. Eight dogs were anesthetized with halothane; blood pressure and a fronto-occipital electroencephalographic lead were monitored. Laudanosine (1 mg . kg-1 iv) was administered as a bolus, and its concentrations in plasma, CSF, urine, and bile were determined by liquid chromatography. Three-compartment modeling of plasma laudanosine concentrations yielded an elimination half-life for laudanosine of 113 +/- 24 min (mean +/- SD) and a clearance of 25 +/- 8 ml . kg-1 . min-1. CSF concentrations of laudanosine were highest 5-10 min after iv injection of laudanosine and ranged in concentration from 208 to 572 ng . ml-1 (i.e., 36-87% of the corresponding plasma concentrations). Unchanged laudanosine was found in urine (0.5-12% of injected dose) and bile (less than 0.1%); metabolites of laudanosine were found in both fluids. After a 6-h sampling period, dogs were hyperventilated with halothane (FIO2 = 0.2) to a PaCO2 of 26-28 mmHg. Laudanosine was then administered 2 mg . kg-1 iv every 5 min. With cumulative doses of 2-8 mg . kg-1, all dogs showed signs of "awakening" from anesthesia. Cumulative doses of 14-22 mg . kg-1 produced seizure activity in all animals. Mean arterial blood pressure decreased significantly to 86% of control levels at 1 min following administration of laudanosine (1 mg . kg-1 iv) and returned to control levels 4 min later.(ABSTRACT TRUNCATED AT 250 WORDS)

Laudanosine (a metabolite of atracurium) increases the minimum alveolar concentration of halothane in rabbits

The authors hypothesized that laudanosine, a metabolite of atracurium and a central nervous system stimulant, might increase the minimum alveolar concentration (MAC) of halothane. An initial study in five rabbits anesthetized with halothane used a two-compartment model to produce estimates of pharmacokinetic variables for laudanosine. These estimates were used to determine the rates of infusion that would produce steady state plasma concentrations of laudanosine of approximately 200, 400, and 800 ng . ml-1. Subsequent infusion of laudanosine in eight rabbits produced mean (+/- SD) steady state plasma concentrations of laudanosine of 234 +/- 56, 457 +/- 66, and 873 +/- 105 ng . ml-1. The control value for MAC of halothane was 1.08 +/- 0.28%. At the lowest steady state plasma laudanosine concentration, MAC did not significantly differ from control (MAC = 1.15 +/- 0.23%, P less than 0.1). However, at 457 and 873 ng . ml-1, laudanosine significantly increased the MAC of halothane by 23% and 30%, respectively. Infusion with saline in two additional rabbits did not affect MAC. Therefore, at the plasma concentrations of laudanosine found in humans after administration of atracurium, laudanosine increased the MAC of halothane in rabbits.