Overexpression of LncRNA FER1L4 in endometrial carcinoma is associated with favorable survival outcome

OBJECTIVE

Long noncoding RNA Fer-1-like protein 4 (FER1L4) is a novel cancer-related lncRNA and functions as a tumor suppressor in several cancers. However, the clinical significance of FER1L4 has not been investigated. The purpose of this study was to investigate whether the increased expression of FER1L4 can be used as a prognostic biomarker in endometrial carcinoma (EC).

PATIENTS AND METHODS

Expression levels of FER1L4 in 191 pairs of EC and adjacent normal tissues were detected by TaqMan Real-time quantitative RT-PCR assay. The association between FER1L4 expression and clinicopathological parameters was subsequently determined. The clinical and prognostic significance of FER1L4 expression was analyzed statistically by Kaplan-Meier estimate and Cox regression model.

RESULTS

We observed that FER1L4 in EC tissues was significantly down-regulated compared with adjacent non-tumor tissues (p<0.01). Low expression of FER1L4 was significantly correlated with distant metastasis (p=0.002), lymph node metastasis (p=0.010) and FIGO stages (p=0.006). Furthermore, Kaplan-Meier survival curves showed that overall survival rate in patients with high FER1L4 expression level was markedly higher than those with low FER1L4 expression level (p=0.0071). Finally, multivariate analysis of the prognosis factors confirmed that low FER1L4 expression was a significant independent predictor of poor survival in EC (HR=2.782, 95% CI: 1.144-5.123, p=0.004).

CONCLUSIONS

We provided the significant clinical relevance of FER1L4 in EC and suggested that FER1L4 may act as an independent prognostic indicator for EC patients.

Ectopic parathyroid adenoma in the submandibular region: a case report

Ectopic parathyroid adenomas that affect the submandibular region have not been widely reported. We describe a 34-year-old man who presented with a painless swelling of the submandibular region. The identification of hypercalcaemia encouraged us to engage a multidisciplinary team to evaluate further serum changes. Parathyroid hormone analysis, ^99mTc-methoxy-isobutyl-isonitrile (^99mTc-MIBI) scintigraphy, and single-photon emission computed tomography (SPECT-CT) were done to rule out hyperparathyroidism. Raised parathyroid hormone together with ^99mTc-MIBI and SPECT-CT examination were consistent with a tumour caused by the hyperparathyroidism. Removal of the lesion resulted in rapid improvement in serum calcium and parathyroid hormone, and the normalisation of the serum creatinine, concentrations. Histopathological analysis confirmed a parathyroid adenoma. We conclude that ectopic parathyroid adenomas should be considered as part of a differential diagnosis for tumours of the submandibular region.

Apoptosis-promoting and migration-suppressing effect of alantolactone on gastric cancer cell lines BGC-823 and SGC-7901 via regulating p38MAPK and NF-κB pathways

BACKGROUND

Gastric cancer is a malignant tumor with high incidence rate and mortality rate.

PURPOSE

In this study, we investigated the anti-cancer effect of alantolactone, a sesquiterpene lactone, on gastric cancer cell lines BGC-823 and SGC-7901.

METHODS

BGC-823 and SGC-7901 cells were treated with different concentrations of alantolactone, Hoechst 33258 staining, flow cytometry, wound healing assay, invasion assay, colony forming assay, quantative polymerase chain reaction, and western blot analysis were used to evaluate the anticancer activity of alantolactone to gastric cancer.

RESULTS

Alantolactone induced apoptosis of gastric cancer cells by regulating the expression of Bax, Bcl-2, and p53, which related to intrinsic apoptotic pathway, and suppressed colony formation, migration, and invasion by mediating the expression of matrix metalloproteinase (MMP)-2, MMP-7, and MMP-9. Cell signaling pathway analysis showed that alantolactone enhanced the phosphorylation of p38 and decreased the translocation of nucleus p65, suggesting that the apoptosis-promoting and migration-suppressing effect of alantolactone might at least partially rely on regulating p38 mitogen-activated protein kinase (p38MAPK) pathway and nuclear factor-κB (NF-κB) pathway.

CONCLUSIONS

Alantolactone can be used as a potential therapeutic agent for treating gastric cancer.

[Preliminary observation on the changes of T(1) weighted signal of globus pallidus after multiple intravenous injection of linear gadolinium contrast agent]

Objective: To explore the changes in signal intensity (SI) ratios of globus pallidus (GP) on unenhanced T(1)-weighted(T(1)WI)magnetic resonance imaging (MRI) scans between the first and last MRI using the linear gadolinium-based contrast agent (GBCAs) intravenously. Methods: Clinical and imaging data of 114 patients who underwent at least 4 consecutive enhanced MRI examinations at the Affiliated Hospital of Xuzhou Medical University between January 2016 and April 2018 were analyzed. The SI ratio of GP, thalamus and cerebrospinal fluid (CSF) were measured on unenhanced T(1)WI. The GP to thalamus SI ratio was calculated by dividing the SI in the GP by that in the thalamus, and so was the GP to CSF SI ratio. The difference of SI ratio in the same patient was analyzed by nonparametric tests, linear regression analysis was used to analyze clinical factors. Results: The SI ratio of GP-to-thalamus and GP-to-CSF after multiple enhancement were higher than before, and the difference was statistically significant. The SI ratio of GP-to-thalamus and GP-to-CSF before and after repeated contrast-enhanced were 1.036(1.010, 1.075), 1.104(1.074, 1.168); 4.215(3.590, 5.614), 5.409(4.213, 6.502), all P<0.01. The SI ratio differences showed a significant positive correlation with the number of enhanced examination(pons:b=0.023, P<0.01,CSF:b=0.279,P=0.034), and a significant negative correlation with the interval (pons: b=-0.002,P< 0.01, CSF: b=-0.023, P=0.039). There was no correlation with other clinical factors (all P>0.05). Conclusions: There is an increase in SI in the GP after serial injections of linear GBCAs, and there is a positive correlation with the times of enhanced examination, and a negative correlation with time interval.

BRAF inhibitors: efficacious and tolerable in BRAF-mutant acral and mucosal melanoma

BRAF inhibitors substantially have impressive clinical efficacy in cutaneous melanoma. However, their role in acral and mucosal melanoma remains unclear. Records were reviewed of patients with metastatic or unresectable BRAF-mutant acral and mucosal melanoma hospitalized and administrated BRAF inhibitors during January 2011 and March 2016. Clinical data were collected to determine PFS, ORR, DCR, OS, and safety. Among 28 acral and 12 mucosal melanoma patients treated with BRAF inhibitors, median PFS were 3.6 (95%CI 3.0-6.4) and 4.4 (95%CI 0.8-12.7) months, median OS were 6.2 (95%CI 6.1-12.1) and 8.2 (95%CI 6.6-19.9) months; ORRs were 38.1% and 20.0%, DCRs were 81.0% and 70.0% in acral and mucosal melanoma, respectively. BRAF inhibitors were well tolerated. The most common adverse effects (AEs) were cutaneous and hematological. Grade 3/4 AEs were relatively rare. In conclusion, BRAF inhibitors have acceptable efficacy and good tolerance in BRAF mutant acral and mucosal melanoma.

MiR-146a regulates osteogenic differentiation and proliferation of bone marrow stromal cells in traumatic femoral head necrosis

OBJECTIVE

  To investigate the regulatory mechanism of micro ribonucleic acid (miR)-146a in osteogenic differentiation and proliferation of bone marrow stromal cells (BMSCs) in traumatic femoral head necrosis.

PATIENTS AND METHODS

Femoral neck fracture patients undergoing surgery were divided into necrosis group and non-necrosis group. The expression level of miR-146a in BMSCs isolated from these patients was detected via quantitative Real Time-Polymerase Chain Reaction (qRT-PCR). The clinical correlation of miR-146a with BMSCs in traumatic femoral head necrosis was explored. The regulatory effects of miR-146a on osteogenic differentiation and proliferation of BMSCs in traumatic femoral head necrosis were detected. Moreover, the cell proliferation was analyzed via cell counting kit-8 (CCK-8) assay. The deposition of calcium on the cell surface was detected via alizarin red staining to evaluate the osteogenic differentiation. The messenger RNA (mRNA) expressions of osteogenesis-specific genes, alkaline phosphatase (ALP), and osteocalcin (Ocn) in BMSCs undergoing osteogenic differentiation were detected via qRT-PCR.

RESULTS

Expression level of miR-146a in BMSCs of necrosis group was significantly lower than that in non-necrosis group, and the difference was statistically significant (p<0.01). CCK-8 assay revealed that the proliferation of BMSCs was significantly enhanced in miR-146a-mimic group compared with that in miR-NC group, while it significantly declined in miR-146a-inhibitor group compared with that in miR-NC group. The results of alizarin red staining showed that the deposition of calcium obviously increased in miR-146a-mimic group compared with that in miR-NC group, indicating that the osteogenic differentiation ability is significantly enhanced, while it markedly decreased in miR-146a-inhibitor group compared with that in miR-NC group. The detection of osteogenesis-specific genes via qRT-PCR manifested that the mRNA expressions of ALP and Ocn remarkably increased in miR-146a-mimic group compared with those in miR-NC group, and there were statistically significant differences (p<0.05). The mRNA expressions of ALP and Ocn remarkably decreased in miR-146a-inhibitor group compared with those in miR-NC group, and there were statistically significant differences (p<0.05), suggesting the inhibited osteogenic differentiation ability.

CONCLUSIONS

We showed that miR-146a regulates the osteogenic differentiation and proliferation of BMSCs in traumatic femoral head necrosis.

[Efficacy and mechanism of loading dose clopidogrel in patients with transient ischemic attack and minor stroke]

Objective: To assess outcome, safety and possible mechanism of loading dose clopidogrel in patients with transient ischemic attack (TIA) and minor stroke. Methods: We reviewed patients with confirmed TIA and minor stroke admitted between July 2016 and December 2017 into the First Affiliated Hospital of Soochow University. Loss-of-function allele carriers of CYP2C19 were included and randomly divided into loading dose group (first dose of 300 mg clopidogrel) and standard dose group (first dose of 75 mg clopidogrel), 100 mg aspirin was gave at the same time, followed by aspirin 100 mg/d plus clopidogrel 75 mg/d maintaining for 20 days. Platelet aggregation (maximum aggregation ratio, MAR) induced by Adenosine diphosphate (ADP) was examined before and 3 days after administration. The National Institutes of Health Stroke Scale (NIHSS) score method was employed to assess the NIHSS scores before and after treatment in each group of patients; the modified Rankin Scale (mRS) was used to assess the 3-month functional outcome. Results: There was no significant difference in baseline data between the two groups (P>0.05).The proportion of early neurological function improvement in the two groups was 75.0% and 54.8%, and the difference was statistically significant (χ(2)=4.498, P=0.034). The 3-month prognosis was 79.5% and 61.3%, and the difference was statistically significant (χ(2)=4.000, P=0.045). Adverse events: 1 case in the loading dose group, 1 case in the standard dose group, the difference was not statistically significant (2.3% vs 1.6%, χ(2)=0.061, P=0.806). After 3 days of antiplatelet therapy, the MAR of the loading dose group decreased (11%±8%), and the MAR of the standard dose group decreased (9%±4%), the difference was statistically significant (P=0.013).In the loading dose group, there were 32 (72.7%)CYP2C19*2 carriers and 42 (95.5%)CYP2C19*2+*3 carriers; early neurological function improvement in 33 cases, accounting for 93.8% and 76.2%, respectively, and the difference was statistically significant (χ(2)=4.122, P=0.042). There were 35 patients with good prognosis in 3 months, accounting for 96.9% and 81.0%, respectively. The difference was statistically significant (χ(2)=4.310, P=0.038); MAR of CYP2C19*2 carrier was decreased (15%±5%), and MAR of CYP2C19*2+*3 carrier was decreased (12%±8%). The difference was statistically significant (P=0.039). Conclusions: Loading dose clopidogrel can improve the clinical prognosis of minor stroke/TIA without increasing the risk of bleeding. Loading dose clopidogrel may improve the prognosis of minor stroke/TIA by decreasing MAR of CYP2C19*2 carriers.

[Impact of first-line chemotherapy on renal function in patients with advanced upper tract urothelial carcinoma]

Objective: To observe the impact of first-line chemotherapy on renal function in patients with unresectable/metastatic upper tract urothelial carcinoma(UTUC). Methods: A total of 222 (130 males and 92 females) unresectable/metastatic upper tract urothelial carcinoma patients were included in the study between January 2005 and May 2017, with age of 29 to 87 (62.4±10.1) years old. The serum creatinine level and estimated glomerular filtration rate (eGFR) were compared before and after first-line chemotherapy. And predictive factors for decreased renal function were analyzed in logistic regression model. Results: After the first-line chemotherapy, the average serum creatinine level increased, with a median changing value of 1.5 μmol/L. Howerver, the eGFR improved, with a median changing value of 0.5 ml·min^-1· (1.73 m²)^-1, but the differences were not statistically significant (all P>0.05). In 149 patients who were treated with cisplatin-based chemotherapy, the average serum creatinine level increased by 1.31 μmol/L and eGFR improved by 0.14 ml·min^-1·(1.73 m²)^-1, but the differences were not statistically significant (P>0.05). In multivariate logistic regression model, age more than and equal to 60 years old (OR=0.88, P=0.745) and cisplatin-based chemotherapy (OR=0.95, P=0.893) did not increase the risk of renal dysfunction after first-line chemotherapy. If the time interval between surgery and first-line chemotherapy was more than 1 year, the risk of renal dysfunction due to chemotherapy decreased (OR=0.54, P=0.196). Eastern Cooperative Oncology Group Performance Status (ECOG PS) Scale≥1 (OR=1.81, P=0.131), anemia before treatment (OR=1.14, P=0.764), the cycles of first-line chemotherapy (OR=1.41, P=0.398) may lead to increase the risk of renal dysfunction, but the differences were not statistically significant. However in the patients who accepted nephrectomy, the risk of renal dysfunction after chemotherapy increased, but the difference was still not statistically significant (OR=3.06, P=0.089). Conclusions: First-line chemotherapy, especially the cisplatin-based regimen, had no significant impact on renal function in the patients with UTUC. Nephrectomy maybe a predictive risk factor for decreased renal function after chemotherapy. Adequate assessment of renal function before treatment, hydration and close monitoring during chemotherapy can effectively protect renal function of the patients.

[Effects and mechanism of apolipoprotein A5 on adipogenic differentiation of human adipose-derived mesenchymal stem cells]

Objective: To investigate the effect and related mechanism of apolipoprotein A5 (ApoA5) on adipogenic differentiation of human adipose-derived mesenchymal stem cells (AMSC). Methods: Subcutaneous adipose tissue was obtained from 40 patients undergoing abdominal surgery at our hospital from February to July 2015. After induction of human AMSC by collagenase digestion, the adipose tissue was induced to differentiate into mature adipocytes and treated with ApoA5 at 600 and 1 200 ng/ml, respectively (ApoA5 intervention groups). Cells treated without ApoA5 protein were used as control group. The cells were harvested on the 7th and 14th day of differentiation, and the following assays were performed: (1) the effect of ApoA5 on TG content was measured by a TG assay kit; (2) RT-qPCR assay was used to detect the effect of ApoA5 on aP2 and FAS mRNA expression; (3) the effect of ApoA5 on the expression of CIDEC mRNA and protein was detected by RT-qPCR and Western blot; (4) the effect of ApoA5 on the expression of C/EBPβ mRNA and protein was detected by RT-qPCR and Western blot; (5) using lentiviral transfection technique, we overexpressed the gene of CIDEC in AMSC and cells were divided into lentiviral negative control group, lentiviral over-expressed CIDEC group and lentiviral over-expressed CIDEC+ApoA5 intervention group (the ApoA5 intervention concentration was 1 200 ng/ml). Thereby, we examined the effect of ApoA5 on the above indicators in adipogenic differentiation of AMSC in the case of CIDEC overexpression. Results: (1) Effect of ApoA5 on TG content in AMSC: on the 7th and 14th day after the intervention, the TG levels were lower in ApoA5 600 and 1 200 ng/ml group AMSC than those in the control group (all P<0.05). (2) The effect of ApoA5 on the expression of aP2 and FAS mRNA in AMSC: on the 7th day after intervention, the expression levels of aP2 and FAS mRNA were significantly lower in ApoA5 600 and 1 200 ng/ml group than those in the control group (all P<0.05). On the 14th day after intervention, the expression levels of aP2 and FAS mRNA were lower in ApoA5 600 and 1 200 ng/ml group than those in the control group (all P<0.05). (3) The effect of ApoA5 on the mRNA and protein expression of CIDEC in AMSC: on the 7th day after intervention, the mRNA and relative protein expression levels of CIDEC were significantly lower in AMSC of ApoA5 600 and 1 200 ng/ml group than those of the control group (all P<0.05). On the 14th day after intervention, the mRNA and relative protein levels of CIDEC were further reduced in ApoA5 600 and 1 200 ng/ml AMSC groups than those in the control group (all P<0.05). (4) The effect of ApoA5 on C/EBPβ mRNA and protein expression in AMSC: on the 7th day after intervention, C/EBPβ mRNA and relative protein expression levels were significantly lower in ApoA5 600 and 1 200 ng/ml group than those in the control group (all P<0.05). On the 14th day after intervention, the levels of C/EBPβ mRNA and relative protein were lower in ApoA5 600 and 1 200 ng/ml group than those in the control group (all P<0.05). (5) The effect of ApoA5 on the content of TG in AMSC after CIDEC overexpression: on the 7th and 14th day after intervention, the TG contents in AMSC were higher in the lentivirus over-expressed CIDEC group than in the lentivirus negative control group (both P<0.05). However, TG contents in AMSC were similar between the over-expressed CIDEC group and the CIDEC+ApoA5 over-expression group (both P>0.05). (6) The effect of ApoA5 on the expression of aP2 and FAS mRNA in AMSC after CIDEC overexpression: on the 7th day after intervention, the expression levels of aP2 and FAS mRNA in AMSC were higher in the lentivirus over-expressed CIDEC group than in the lentivirus negative control group (both P<0.05). On the 14th day after intervention, the expression level of aP2 mRNA in the AMSC was higher in the lentivirus over-expressed CIDEC group than in the lentivirus negative control group (P<0.05). On the 7th and 14th day after intervention, the expression levels of aP2 and FAS mRNA in AMSC were similar between the lentivirus over-expressed CIDEC group and the lentivirus over-expressed CIDEC+ApoA5 group (all P>0.05). (7) The effect of ApoA5 on the expression of C/EBPβ mRNA and protein in AMSC after CIDEC overexpression: on the 7th day after intervention, the mRNA and relative protein expressions of C/EBPβ in AMSC were higher in lentivirus-overexpressed CIDEC group than in lentivirus negative control group (both P <0.05). On the 14th day after intervention, C/EBPβ mRNA and protein expression levels in AMSC were higher in the lentivirus over-expressed CIDEC group than in the lentivirus negative control group (both P<0.05). On the 7th and 14th day after intervention, the expressions of C/EBPβ mRNA and protein in AMSC were similar between lentivirus over-expressed CIDEC group and lentivirus over-expression CIDEC+ApoA5 intervention group (all P>0.05). Conclusions: ApoA5 can inhibit the adipogenic differentiation of AMSC,and this effect may be mediated by down-regulating the expression of CIDEC. Furthermore, our results indicate that CIDEC could be considered as a key factor in adipogenic differentiation.

[Changes in renal function after catheter ablation in patients with persistent atrial fibrillation]

Objective: The aim of the study was to evaluate the changes and outcome of kidney function after catheter ablation in patients with persistent atrial fibrillation (PAF). Methods: A total of 146 patients with PAF underwent primary atrial fibrillation (AF) ablation were enrolled from January 2013 to December 2014 and followed up. The subjects were divided into the AF recurrence and AF non recurrence groups. The estimated glomerular filtration rate (eGFR) was calculated and serum creatinine levels were detected before ablation and during follow-up. Renal failure was defined as ≥ 25% decline in eGFR. Kaplan-Meier survival curves was applied for the incidence of renal failure. Cox proportional hazards models were conducted to assess the relationship between recurrence of AF and renal failure. Results: After (16.3±11.8) months of follow-up, the eGFR in patients with no recurrence of AF was higher than that in patients with recurrence. eGFR and ΔeGFR in patients with no AF recurrence differed significantly from those in patients with recurrence [(114.15±18.24) ml·min(-1)·1.73m(-2) vs. (98.64±24.09) ml·min(-1)·1.73m(-2), and (7.42±6.36) ml·min(-1)·1.73m(-2) vs. (-11.40±10.19) ml·min(-1)·1.73m(-2), all P<0.001]. The incidence of the renal failure was significantly lower (4.41% vs. 16.67%, P<0.05) and the survival prognosis was significantly better in patients with no recurrence than those in patients with recurrence (χ(2)=5.965, log-rank P=0.05). The multivariate Cox regression analysis revealed that age, baseline eGFR, recurrences of AF and diabetes were independent predictors of the renal failure, with the HR 1.152, 1.086, 13.442 and 6.076, respectively. Conclusions: PAF patients with no recurrence after ablation had a better renal function than those with recurrence, and the recurrence of AF is associated with the deterioration of kidney function in patients with PAF.

[The similarities and differences of mandarin open-set word recognition between cochlear implant children and normal hearing children]

Objective:To evaluate the ability of open-set word recognition in cochlear implant (CI) children,and compare the similarities and difference of open-set word recognition between CI children and normal hearing(NH) children.Method:This study included 485 children with CI and 162 children with NH, who completed the Mandarin lexical neighborhood test. The results for children at 1-8 years after receiving their CI were compared to those from the children with NH using analysis of variance.Result:There were significant differences in open-set word recognition between the CI and NH groups(P<0.05).For implantation before 2 years, there was no significant difference in recognition at the ages of 6-7 years,compared to 3-year-old children with NH, or at the age of 10 years, compared to 6-year-old children with NH(P>0.05).For implantation before 3 years, there was no significant difference in recognition at the ages of 8-9 years, compared to 3-year-old children with NH,or at the age of 10 years, compared to 6-year-old children with NH(P>0.05).For implantation after 3 years, there was a significant difference in recognition at the age of 13 years,compared to 3-year-old children with NH(P<0.05).Conclusion:Mandarin open-set word recognition increased with time after CI.Chinese children with CI had delayed but similar development of recognition, compared to normal children. Early CI can shorten the gap between children with CI and normal children.

Geniposide prevents H2 O2 -induced oxidative damage in melanocytes by activating the PI3K-Akt signalling pathway

BACKGROUND

Oxidative stress is one possible pathogenic event in vitiligo that induces melanocyte destruction. Geniposide exerts certain antioxidant effects on various cells by activating the phosphoinositol 3-kinase (PI3K)-Akt signalling pathway. However, researchers have not clearly determined whether geniposide protects human melanocytes from oxidative stress or identified the underlying mechanism of such protection.

AIM

To determine whether geniposide protects melanocytes from H₂ O₂ -induced oxidative damage and to explore the role of the PI3K-Akt signalling pathway in this protective effect.

METHODS

The antioxidant effects of geniposide on human melanocytes were examined by measuring cell viability, apoptosis rates, reactive oxygen species (ROS) production and activities of the antioxidant enzymes superoxide dismutase (SOD) and catalase (CAT). We examined expression of Akt, phosphorylated Akt (p-Akt), Bcl-2, Bax, and cleaved caspase 3 and cleaved caspase 9 proteins to determine the involvement of the PI3K-Akt pathway.

RESULTS

Pretreatment with geniposide 5, 25, 125 or 625 μmol/L increased cell viability and decreased the apoptosis rate of H₂ O₂ -treated melanocytes. In addition, geniposide enhanced the antioxidant activity of SOD and CAT, and decreased intracellular ROS accumulation. Furthermore, geniposide increased the levels of p-Akt and regulated the expression of downstream proteins in the PI3K-Akt pathway, such as Bcl-2, Bax, and cleaved caspase 3 and 9, in H₂ O₂ -treated melanocytes. Notably, these effects were largely blocked by treatment with LY294002 prior to H₂ O₂ treatment.

CONCLUSIONS

Based on these results, geniposide protects human melanocytes from H₂ O₂ -induced oxidative damage, and the PI3K-Akt signalling pathway is involved in its antioxidant effect.

Rapid in-focus corrections on quantitative amplitude and phase imaging using transport of intensity equation method

Transport of intensity equation (TIE) method can acquire sample phase distributions with high speed and accuracy, offering another perspective for cellular observations and measurements. However, caused by incorrect focal plane determination, blurs and halos are induced, decreasing resolution and accuracy in both retrieved amplitude and phase information. In order to obtain high-accurate sample details, we propose TIE based in-focus correction technique for quantitative amplitude and phase imaging, which can locate focal plane and then retrieve both in-focus intensity and phase distributions combining with numerical wavefront extraction and propagation as well as physical image recorder translation. Certified by both numerical simulations and practical measurements, it is believed the proposed method not only captures high-accurate in-focus sample information, but also provides a potential way for fast autofocusing in microscopic system.

Comparative studies on the fermentation performance of autochthonous Saccharomyces cerevisiae strains in Chinese light-fragrant liquor during solid-state or submerged fermentation

AIM

To explore the metabolic characteristic of autochthonous Saccharomyces cerevisiae strains in Chinese light-fragrant liquor fermentation.

METHODS AND RESULTS

Inter-delta amplification analysis was used to differentiate the S. cerevisiae strains at strain level. Twelve biotypes (I-XII) were identified among the 72 S. cerevisiae strains preselected. A comparison was conducted between solid-state fermentation (SSF) and submerged fermentation (SmF) with S. cerevisiae strains had different genotype, with a focus on the production of ethanol and the volatile compounds. The degree of ethanol ranged from 28·0 to 45·2 g l^-1 in SmF and from 14·8 to 25·6 g kg^-1 in SSF, and SSF was found to be more suitable for the production of ethanol with higher yield coefficient of all the S. cerevisiae strains. The metabolite profiles of each yeast strain showed obvious distinction in the two fermentations. The highest amounts of ethyl acetate in SmF and SSF were found in genotype VII (328·2 μg l^-1 ) and genotype V (672 μg kg^-1 ), respectively. In addition, the generation of some volatile compounds could be strictly related to the strain used. Compound β-damascenone was only detected in genotypes I, II, X and XII in the two fermentation processes. Furthermore, laboratory scale fermentations were clearly divided into SSF and SmF in hierarchical cluster analysis regardless of the inoculated yeast strains, indicating that the mode of fermentation was more important than the yeast strains inoculated.

CONCLUSION

The autochthonous S. cerevisiae strains in Chinese light-fragrant liquor vary considerably in terms of their volatiles profiles during SSF and SmF.

SIGNIFICANCE AND IMPACT OF THE STUDY

This work facilitates a better understanding of the fermentative mechanism in the SSF process for light-fragrant liquor production.