[Protective effect of baicalein on high fat-induced hepatocytes oxidative damage].

Objective: To investigate the effect of baicalein in improving non-alcoholic fatty liver disease caused by high fat-induced oxidative damage in mice. Methods: Male C57BL/6J mice weighing 18-20 g were randomly divided into 4 groups: normal control group (C, 10% fat for energy), high-fat group (H, 60% fat for energy), high-fat + scutellaria baicalein group (H+B, baicalein: 400 mg·kg(-1)·bw(-1)), and baicalein control group (B, baicalein: 400 mg·kg(-1)·bw(-1)). After 12 weeks, mice were sacrificed, and the tissue samples were collected. Liver pathological changes were observed by hematoxylin and eosin staining. Mitochondrial morphology was examined by ultramicropathology. Malondialdehyde (MDA), superoxide dismutase (SOD), glutathione (GSH) and mitochondrial membrane potential (MMP) changing levels in the liver were determined by kit. Sestrin2 and protein carbonylation (PCOS) levels were detected by Western blotting. Small interfering RNA (siRNA) was used to knock-down the Sestrin2 protein expression in HepG2 cells. Intramyocellular lipid changes in HepG2 cells was detected by fluorescent dye BODIPY493/503. One way ANOVA was used LSD pairwise comparison method was used to test the statistical difference. Results: Compared with the normal control group, high-fat fed caused significant fatty degeneration, decreased GSH and SOD levels (P ​​< 0.05), increased MDA and protein carbonylation levels, and increased Sestrin2 expression (P < 0.05) in mice. Mitochondrial shape changes, swelling, lack of cristae, and MMP was down-regulated by 33.3% (t = 13.456, P ​​< 0.001). Baicalein intervention had effectively inhibited hepatic steatosis and oxidative damage caused by high-fat fed, and further up-regulated Sestrin2 expression, MMP (t = 10.104, P ​​< 0.001), and significantly alleviated liver damage in mice. Sestrin2 expression knock-down had further increased the intracellular lipid deposition and PCOs expression (P ​​< 0.05), and reduced baicalein ability to antagonize lipid deposition and antioxidant capacity in Hep2 cells. Conclusion: Baicalein alleviate non-alcoholic fatty liver by regulating Sestrin2 expression and high-fat fed-induced liver oxidative damage.

Real-Time Motor Cortex Mapping for the Safe Resection of Glioma: An Intraoperative Resting-State fMRI Study.

BACKGROUND AND PURPOSE: Resting-state functional MR imaging has been used for motor mapping in presurgical planning but never used intraoperatively. This study aimed to investigate the feasibility of applying intraoperative resting-state functional MR imaging for the safe resection of gliomas using real-time motor cortex mapping during an operation. MATERIALS AND METHODS: Using interventional MR imaging, we conducted preoperative and intraoperative resting-state intrinsic functional connectivity analyses of the motor cortex in 30 patients with brain tumors. Factors that may influence intraoperative imaging quality, including anesthesia type (general or awake anesthesia) and tumor cavity (filled with normal saline or not), were studied to investigate image quality. Additionally, direct cortical stimulation was used to validate the accuracy of intraoperative resting-state fMRI in mapping the motor cortex. RESULTS: Preoperative and intraoperative resting-state fMRI scans were acquired for all patients. Fourteen patients who successfully completed both sufficient intraoperative resting-state fMRI and direct cortical stimulation were used for further analysis of sensitivity and specificity. Compared with those subjected to direct cortical stimulation, the sensitivity and specificity of intraoperative resting-state fMRI in localizing the motor area were 61.7% and 93.7%, respectively. The image quality of intraoperative resting-state fMRI was better when the tumor cavity was filled with normal saline (P = .049). However, no significant difference between the anesthesia types was observed (P = .102). CONCLUSIONS: This study demonstrates the feasibility of using intraoperative resting-state fMRI for real-time localization of functional areas during a neurologic operation. The findings suggest that using intraoperative resting-state fMRI can avoid the risk of intraoperative seizures due to direct cortical stimulation and may provide neurosurgeons with valuable information to facilitate the safe resection of gliomas.

Can resonance frequency analysis detect narrow marginal bone defects around dental implants? An ex vivo animal pilot study.

BACKGROUND: Resonance frequency analysis (RFA) is applied to assess implant stability, as expressed by the implant stability quotient (ISQ). This study aimed to investigate the potential of RFA devices to identify narrow marginal bone defects around implants. METHODS: Twenty-eight Straumann bone level (BL) implants and 28 bone level tapered (BLT) implants were placed ex vivo in porcine ribs. Implants in the control group (A) were fully submerged in the bone. In three experimental groups, implants were placed with a 0.9-mm circumferential marginal bone defect extending 2 mm (B), 4 mm (C) and 6 mm (D) apically. Two RFA devices were used to measure implant stability. RESULTS: ISQ values decreased as the defects' depth increased, with the greatest reduction observed between full bone (A) and 2-mm defects (B) (P < 0.001). No significant differences were found in the ISQ values recorded from BL and BLT implants. CONCLUSIONS: ISQ values can effectively detect narrow, intrabony marginal bone defects, in particular when involving the first coronal 2 mm. This finding could have implications for the early diagnosis of conditions affecting the marginal bone, such as peri-implantitis. Further research is required to investigate if such findings can be replicated after osseointegration is achieved.

A comparison of left and right atrial fibroblasts reveals different collagen production activity and stress-induced mitogen-activated protein kinase signalling in rats.

AIM: Atrial fibrosis plays a pivotal role in the pathophysiology of heart failure (HF). The left atrium (LA) experiences greater fibrosis than the right atrium (RA) during HF. It is not clear whether LA cardiac fibroblasts contain distinctive activities that predispose LA to fibrosis. METHODS: LA and RA fibrosis were evaluated in healthy and isoproterenol-induced HF Sprague Dawley rats. Rat LA and RA primary isolated fibroblasts were subjected to proliferation assay, oxidative stress assay, cell migration analysis, collagen measurement, cytokine array and Western blot. RESULTS: Healthy rat LA and RA had a similar extent of collagen deposition. HF significantly increased fibrosis to a greater severity in LA than in RA. Compared to isolated RA fibroblasts, the in vitro experiments showed that isolated LA fibroblasts had higher oxidative stress and exhibited higher collagen, transforming growth factor-ß1, connective tissue growth factor production and less vascular endothelial growth factor (VEGF) production, but had similar migration, myofibroblast differentiation and proliferation activities. VEGF significantly increased the collagen production ability of LA fibroblasts, but not RA fibroblasts. LA fibroblasts had more phosphorylated ERK1/2 and P38 expression. ERK inhibitor (PD98059, 50 µmol L-1 ) significantly attenuated collagen production and increased VEGF production in RA fibroblasts but not in LA fibroblasts. P38 inhibitor (SB203580, 30 µmol L-1 ) significantly attenuated collagen production in LA fibroblasts but not in RA fibroblasts. P38 inhibitor also significantly increased VEGF production in RA and LA fibroblasts. CONCLUSIONS: Differences in profibrotic activity between LA and RA fibroblasts may be caused by different responses to mitogen-activated protein kinase signalling.

Fanconi anemia pathway--the way of DNA interstrand cross-link repair.

The study of rare genetic diseases usually inspires the research of cancer biology. Fanconi anemia (FA), is a rare cancer susceptibility syndrome with an incidence of only 1 per 350,000 births. FA is an autosomal recessive disease with three main features: chromosome instability, hypersensitivity to DNA cross-linking agents such as mitomycin C (MMC), cisplatin and so on, and susceptible to a number of cancer types, mainly leukemia and squamous cell carcinomas of the head and neck or gynecologic system. DNA crosslinking agents may led to DNA cross-linking lesion, and Fanconi anemia pathway plays a key role in repairing its cross-linking. However, FA pathway is closely linked with carcinogenesis and tumor drug resistance. This paper mainly focuses on the FA pathway and its progress in cancer research.

A sparse intraoperative data-driven biomechanical model to compensate for brain shift during neuronavigation.

BACKGROUND AND PURPOSE: Intraoperative brain deformation is an important factor compromising the accuracy of image-guided neurosurgery. The purpose of this study was to elucidate the role of a model-updated image in the compensation of intraoperative brain shift. MATERIALS AND METHODS: An FE linear elastic model was built and evaluated in 11 patients with craniotomies. To build this model, we provided a novel model-guided segmentation algorithm. After craniotomy, the sparse intraoperative data (the deformed cortical surface) were tracked by a 3D LRS. The surface deformation, calculated by an extended RPM algorithm, was applied on the FE model as a boundary condition to estimate the entire brain shift. The compensation accuracy of this model was validated by the real-time image data of brain deformation acquired by intraoperative MR imaging. RESULTS: The prediction error of this model ranged from 1.29 to 1.91 mm (mean, 1.62 ± 0.22 mm), and the compensation accuracy ranged from 62.8% to 81.4% (mean, 69.2 ± 5.3%). The compensation accuracy on the displacement of subcortical structures was higher than that of deep structures (71.3 ± 6.1%:66.8 ± 5.0%, P < .01). In addition, the compensation accuracy in the group with a horizontal bone window was higher than that in the group with a nonhorizontal bone window (72.0 ± 5.3%:65.7 ± 2.9%, P < .05). CONCLUSIONS: Combined with our novel model-guided segmentation and extended RPM algorithms, this sparse data-driven biomechanical model is expected to be a reliable, efficient, and convenient approach for compensation of intraoperative brain shift in image-guided surgery.

Effects of overexpression of HBP1 upon growth and differentiation of leukemic myeloid cells.

HMG-box containing protein 1 (HBP1) is a member of the high mobility group (HMG) of chromosomal proteins. Since HBP1 exhibits tumor-suppressor activity in nonmyeloid tissues, we examined the effects of ectopic overexpression of HBP1 upon the growth and differentiation of myeloid cells. We prepared transient and stable transfectants of the myeloblast cell line K562, which overexpress HBP1 mRNA and protein. HBP1 transfectants displayed slower growth in cell culture and reduced colony formation in soft agar, retardation of S-phase progression, reduced expression of cyclin D1 and D3 mRNAs and increased expression of p21 mRNA. HBP1 transfectants also underwent increased apoptosis, as demonstrated by morphology and binding of Annexin V. Fas ligand mRNA levels were increased in HBP1 transfectants, suggesting involvement of the Fas/Fas ligand pathway. HBP1 overexpression enhanced differentiation of K562 cells towards erythroid and megakaryocyte lineages, as evidenced by increased hemoglobin and CD41a expression. Overexpression of HBP1 modulated mRNA levels for myeloid-specific transcription factors C/EBPalpha, c-Myb, c-Myc, and JunB, as well as lineage-specific transcription factors PU.1, GATA-1, and RUNX1. These findings suggest that in myeloid cells HBP1 may serve as a tumor suppressor and a general differentiation inducer and may synergize with chemical differentiating agents to enhance lineage-specific differentiation.

Effects of gentamicin and pH on [Ca2+]i in apical and basal outer hair cells from guinea pigs.

Aminoglycosides are widely used antibiotics and frequently produce acute ototoxicity. In this study we attempted to comparatively investigate the effects of gentamicin on Ca2+ influx of apical and basal outer hair cells (OHCs) isolated from guinea-pig cochlea. Since the solution of gentamicin sulfate salt is acidic (pH 3.1-3.3), we also explored the effect of external acidification on Ca2+ influx. By means of fura-2 microspectrofluorimetry, we measured the intracellular calcium concentration ([Ca2+]i) of OHCs bathed in Hanks' balanced salt solution (pH 7.40) during either a resting state or high K+-induced depolarization. Our results show that at the resting state, the baseline [Ca2+]i in apical OHCs (94+/-2.0 nM) was slightly lower than that in basal OHCs (101.1+/-2.4 nM). By contrast, the increase in [Ca2+]i evoked by high K+ depolarization in apical OHCs was about two-fold greater than that in basal OHCs. Nifedipine (30 microM) abolished the increased [Ca2+]i in both types of OHCs, suggesting that Ca2+ influx was mainly through L-type Ca2+ channels of OHCs. While gentamicin and extracellular acidification (pH 7.14) can separately attenuate this increase in [Ca2+]i in both types of OHCs, their suppressive effects are additive in basal OHCs, but not in apical OHCs. The implications of these findings are that: (1) apical and basal OHCs behave differently in response to depolarization-increased [Ca2+]i, and (2) basal OHCs are more vulnerable to the impairment of Ca2+ entry during depolarization by a combination of gentamicin and extracellular acidification, which is correlated with the clinical observation that ototoxicity of aminoglycosides at the basal coil of OHCs is more severe than that at the apical coils. Moreover, the possibility that extracellular acidification may enhance the acute ototoxic effects of aminoglycosides should be considered especially in topical applications.

Astrocytes modulate thapsigargin-induced changes in calcium concentration and neuronal survival.

When mature cerebellar granule neurons (CGN) grown in high K+ (25 mM K+, HK)-serum containing medium are subjected to the HK/serum deprivation, they are destined for neuronal death. In this study, we attempted to elucidate the roles of endoplasmic reticular (ER) Ca2+-store and co-cultured astrocytes in HK/serum deprivation induced neuronal death. Thapsigargin (TG), an inhibitor of ER Ca2+-ATPase was simultaneously applied with normal K+ (5 mM K+, NK) serum free medium, and its effects on neuronal death in either astrocyte-poor or astrocyterich culture were examined. By means of the fura-2 microfluorimetric technique, we monitored the changes of the intracellular Ca2+ concentration, [Ca2+]i, associated with neuronal death under various treatments. The results obtained showed that in astrocyte-poor cultures of mature CGN (10 days in vitro, DIV), the basal level of [Ca2+]i markedly decreased from 184 +/- 5 to 89.7 +/- 5 nM 24 h after HK/serum deprivation. Although treatment with TG slightly increased the [Ca2+]i to 117.6 +/- 4 nM, the survival rate of the neurons was even worse; it was reduced from 49 +/- 4% to 28 +/- 2%. In the astrocyte-rich cultures, HK/serum deprivation also caused a profound reduction of neuronal [Ca2+]i, from 166 +/- 3 to 90.2 +/- 6 nM, accompanied by even more serious neuronal death (95.5 +/- 1%). On the other hand, treatment with TG in astrocyterich cultures further lowered the [Ca2+]i to 65 +/- 2 nM but markedly improved the neuronal survival rate from 4.5 +/- 1% to 60 +/- 2% in a concentration-dependent manner. The strong implication of these findings is that ER Ca2+-store and astrocytes participate in modulating the responses of neurons to stress stimulation.

Protein gene product 9.5-immunoreactive neurons in the retina of striped dolphin (Stenella coeruleoalba) and Fraser dolphin (Lagenodelphis hosei).

This study demonstrates immunocytochemically that protein gene product 9.5 (PGP 9.5), a neuronal marker, is expressed by various populations of retinal cells in Stenella coeruleoalba (striped dolphin) and Lagenodelphis hosei (Fraser dolphin): one in the retinal ganglion cells and the other in the inner nuclear layer, resembling horizontal and amacrine cells. The specific distribution of PGP 9.5 in a dolphin closely resembles that in rodents and carnivores; however, some differences arise among these animals. In a dolphin's retina, for example, only a few of giant ganglion cells are immunoreacted while almost all the small ganglion cells are stained strongly. The processes of horizontal cells, identified according to their localization, appear not to connect entirely in a dolphin. Instead, PGP 9.5 positive cells are widely distributed in the small to moderate ganglion cells and have distinct processes which are ramified extensively in the outer plexiform layer in rodents and carnivores. The high levels of PGP 9.5 expressing in the inner part of dolphin retina, including ganglion cells and their axons as well as distinct sublamination in the inner plexiform layer, indicate that this molecule markedly influences the retinal system, possibly in visual connection. Although mammals have various visual behavior, i.e., living marine vs. terrestrial environment, and active during daytime vs. in the night, the retina is a common model to characterize the neurochemical properties.

Roles of thapsigargin-sensitive Ca2+ stores in the survival of developing cultured neurons.

The roles of the intracellular calcium pool involved in regulating the Ca2+ profile and the neuronal survival rate during development were studied by using thapsigargin (TG), a specific inhibitor of endoplasmic reticulum (ER) Ca2+-ATPase in cultured cerebellar granule neurons. Measuring the neuronal [Ca2+]i directly in the culture medium, we found a bell-shaped curve for [Ca2+]i versus cultured days in cerebellar granule neurons maintained in medium containing serum and 25 mM K+. The progressive increase in [Ca2+]i of the immature granule neurons (1-4 days in vitro) was abolished by TG, which resulted in massive neuronal apoptosis. When the [K+] was lowered from 25 to 5 mM, neither the progressively increasing [Ca2+]i nor the survival of immature granule neurons was significantly changed over 24-h incubation. Similarly, TG caused a dramatic decrease in the [Ca2+]i and survival rate of these immature neurons when switched to 5 mM K+ medium. Following maturation, the granule neurons became less sensitive to TG for both [Ca2+]i and neuronal survival. However, TG can protect mature granule neurons from the detrimental effect of switching to a 5 mM K+ serum-free medium by decreasing [Ca2+]i to an even lower level than in the respective TG-free group. Based on these findings, we propose that during the immature stage, TG-sensitive ER Ca2+-ATPase plays a pivotal role in the progressive increase of [Ca2+]i, which is essential for the growth and maturation of cultured granule neurons.

Altered intracellular calcium level in association with neuronal death induced by lithium chloride.

In this study, we examined the effects of lithium chloride (LiCl) on the intracellular calcium levels ([Ca2+]i), and the survival of immature and mature cultured cerebellar granule neurons (CGNs) grown in medium containing high (25 mmol/L) or normal (5 mmol/L) potassium (K+) levels. LiCl dramatically reduced [Ca2+]i in immature CGNs maintained in high K+ (HK) medium and in those switched to serum containing normal K+ (NK) medium for 1 to 2 days. This reduction in [Ca2+]i led to massive neuronal death of immature neurons developed in both HK and NK medium. In mature (cultured 5-8 days in vitro) CGNs, LiCl exhibited potent toxicity when cells were grown in HK medium, and led to increased [Ca2+]i. Exposing mature CGNs to serum deprivation and normal extracellular K+ concentrations decreased [Ca2+]i and induced cell death, while the addition of LiCl in these conditions further decreased [Ca2+]i but prevented cell death. The morphologic features revealed by Nomarski optics further confirmed these effects of LiCl on neuronal survival. Together, these findings indicate that the effects of LiCl on [Ca2+]i and neuronal death, and the association between [Ca2+]i and cell death, depend on the developmental stage of CGNs and the growth conditions to which they are subjected. These findings may help in understanding the mechanism of neurotoxicity of LiCl during therapy.

Hepatoprotective effects of Taiwan folk medicine: Ixeris chinensis (Thunb.) Nak. on experimental liver injuries.

The hepatoprotective effects of Ixeris chinensis (Thunb.) Nak. were studied on acute hepatitis induced in mice by a single dose of carbon tetrachloride (31.25 microliters/kg, ip) or acetaminophen (600 mg/kg, ip), and in rats by a single dose of beta-D-galactosamine (188 mg/kg, ip). Hepatoprotective activity was monitored by estimating the serum transaminases (SGOT and SGPT) levels and histopathological changes in the livers of experimental animals. The Ixeris chinensis (Thunb.) Nak. extracts significantly inhibited the acute elevation of serum transaminases. Histopathologically, the crude I. chinensis extract significantly ameliorated hepatotoxin-induced histopathological changes in the livers of experimental animals. All pharmacological and histopathological effects of Ixeris chinensis (Thunb.) Nak. were compared with Bupleurum chinense DC., which has been previously reported as a treatment herb for hepatitis.