Diclazuril-induced expression of CDK-related kinase 2 in the second-generation merozoites of Eimeria tenella.

Diclazuril is a classic anticoccidial drug. The key molecules of diclazuril in anticoccidial action allows target screening for the development of anticoccidial drugs. Cyclin-dependent kinases (CDK) are prominent target proteins in apicomplexan parasites. In this study, a diclazuril anticoccidiosis animal model was established, and the transcription and translation levels of the CDK-related kinase 2 of Eimeria tenella (EtCRK2) were detected. mRNA and protein expression levels of EtCRK2 decreased in the infected/diclazuril group compared with those in the infected/control group. In addition, immunofluorescence analysis showed that EtCRK2 was localised in the cytoplasm of the merozoites. The fluorescence intensity of EtCRK2 in the infected/diclazuril group was significantly weaker than that in the infected/control group. The anticoccidial drug diclazuril against E.tenella affects the expression pattern of EtCRK2 molecule, and EtCRK2 is a potential target for new drug development.

Hypoglycemic and Hepatoprotective Effects of Dried and Rice-Fried Psidium guajava Leaves in Diabetic Rats.

Psidium guajava leaves (PGL) have been long used as an adjuvant therapy for diabetics. The present study evaluated the in vivo hypoglycemic and hepatoprotective effects of dried and the rice-fried PGL decoctions (PGLD and RPGLD). Our results indicated that both PGLD and RPGLD could significantly decrease the contents of fasting blood glucose (FBG) and haemoglobin A1c (HbA1c) in diabetic rats. Compared with the HFD/STZ (high-fat diet with streptozotocin) group, the PGLD and RPGLD-treated diabetic rats showed different degrees of recovery against the liver pathological changes. The upregulated expressions of glucokinase (GK), glucose transporter 2 (GLUT2), insulin growth factor-1 (IGF-1), insulin receptor substrate-1 (IRS-1), and insulin receptor substrate-2 (IRS-2) in PGLD and RPGLD-treated groups were observed. In general, RPGLD exhibited a much better antidiabetic effect than PGLD, which was further verified by the comprehensive evaluation with the TOPSIS method. Besides, HPLC (high-performance liquid chromatography) and UPLC-MS/MS (ultra-performance liquid chromatography-tandem mass spectrometry) analyses revealed that the contents of the primary constituents (ellagic acid, hyperoside, isoquercitroside, reynoutrin, guaijaverin, auicularin, and quercetin) in RPGLD increased obviously compared with PGLD. These results shed new light on the antidiabetic potential and mechanism of PGL, as well as the "higher efficacy" of the rice-fried processing method in traditional Chinese medicine.

Anticoccidial effect of toltrazuril and Radix Sophorae Flavescentis combination: Reduced inflammation and promoted mucosal immunity.

An anticoccidial model of chicken infected with Eimeria tenella was established to investigate the effect of toltrazuril (Tol) combined with the Radix Sophorae Flavescentis (RSF) on coccidiosis. The anticoccidial index (ACI) was evaluated, and the cecal developmental parameters (i.e., villus height, [VH], crypt depth, [CD], and VH/CD) were determined. The distributions of glycoproteins and goblet cells in the cecal tissue were determined through the Periodic Acid-Schiff (PAS) and Alcian blue PAS staining methods, respectively. The mRNA expression levels of interleukin (IL)-1ß, IL-2, IL-4, IL-6, IL-10, and IL-17 of the cecal tissue were determined through quantitative real-time PCR. The moderate ACI was obtained using the combination of Tol and RSF. Compared with the normal control (NC) group, the infected control (IC) group showed remarkably lower VH and VH/CD at five and seven days postinfection. Compared with the IC group, the IC + RSF and IC + TolRSF groups showed remarkably higher VH and VH/CD at five and seven days postinfection. Compared with the NC group, the IC group contained fewer glycoproteins and goblet cells, but the Tol and RSF treatment promoted more glycoproteins and goblet cells at five and seven days postinfection. The mRNA expression levels of IL-1ß, IL-2, IL-4, IL-6, IL-10, and IL-17 in the IC group were upregulated (P < 0.01) compared with those in the NC group. The IC + RSF and IC + TolRSF groups had downregulated mRNA expression levels of IL-1ß, IL-6, and IL-17 cytokines (P < 0.01), and upregulated mRNA expression levels of IL-2 and IL-4 cytokines (P < 0.01) compared with the IC group. Results showed that the combination of Tol and RSF exerts anticoccidial effect by reducing inflammation and promoting intestinal mucosal immunity.

Effects of diclazuril on the expression of enolase in second-generation merozoites of Eimeria tenella.

Eimeria tenella is an obligate intracellular parasite of the chicken cecum; it brings huge economic loss to the chicken industry. Enolase is a multifunctional glycolytic enzyme involved in many processes of parasites, such as infection and migration. In this study, the effect of diclazuril on the expression of enolase in second-generation merozoites of E. tenella (EtENO) was reported. The prokaryotic expression plasmid pET-28a-EtENO was constructed and transformed into Escherichia coli BL21 (DE3). Then, it was subjected to expression under the induction of isopropyl-ß-D-1-thiogalactopyranoside. The expressed products were identified and purified. The purified EtENO protein was used for antibody preparation. The EtENO mRNA and protein expression levels were analyzed via real-time PCR and Western blotting. Localization of EtENO on the merozoites was examined by immunofluorescence technique. The mRNA and protein expression levels of EtENO were decreased by 36.3 and 40.36%, respectively, by diclazuril treatment. EtENO distributed in the surface, cytoplasm, and nucleus of the infected/control group. With diclazuril treatment, it was significantly reduced in the surface and cytoplasm and even disappeared in the nucleus of the infected/diclazuril group. These observations suggested that EtENO may play an important role in mechanism of diclazuril anticoccidial action and be a potential drug target for the intervention with E. tenella infection.

Holliday junction recognition protein promotes pancreatic cancer growth and metastasis via modulation of the MDM2/p53 signaling.

Holliday junction recognition protein (HJURP) refers to a histone H3 chaperone that has been implicated in different kinds of malignancies. Yet, its character in pancreatic cancer remains unclear. The expression of HJURP was assessed in PDAC tissues by RT-qPCR, immunoblotting, and immunohistochemistry. HJURP-deficient or overexpressed PDAC cell lines were constructed, using shRNA or plasmids with HJURP insert. MTT, sphere formation assay, migration, and invasion assays were performed to evaluate the viability, proliferation, migration, and invasion of PDAC cells. We used xenograft mice models to assess the tumor growth and metastasis in vivo. RNA-seq was applicated in search of the potential downstream target of HJURP in PDAC and subsequent verification were fulfilled via multiple assays, including immunofluorescence. Additionally, chromatin immunoprecipitation and luciferase reporter assay were conducted to explore the potential regulation of MDM2 expression by HJURP through H3K4me2. In this current research, we found that the expression of HJURP in PDAC cells and tissue was significantly higher than those of adjacent normal tissue, and high HJURP expression predicted poor survival. HJURP significantly promoted the viability, sphere formation, migration, and invasion of PDAC cells in vitro, HJURP also facilitated tumor growth and metastasis in vivo. Mechanically, MDM2/p53 axis is critical for HJURP-mediated malignant behaviors in PDAC, and HJURP regulates MDM2 expression through H3K4me2. HJURP could serve as a promising biomarker, and target for PDAC prognosis and treatment.

Effects of Eimeria tenella infection on the barrier damage and microbiota diversity of chicken cecum.

The symbiosis of host and intestinal microbiota constitutes a microecosystem and plays an important role in maintaining intestinal homeostasis and regulating the host's immune system. Eimeria tenella, an obligate intracellular apicomplexan parasite, can cause coccidiosis, a serious intestinal disease. In this study, the effects of E. tenella infection on development parameters (villus height, crypt depth, mucosa thickness, muscularis thickness, and serosa thickness) and microbiota in chicken cecum were investigated. Fourteen-day-old male Hy-Line Variety Brown layer chickens were inoculated with sporulated oocysts of E. tenella. Cecal tissues were collected 7 d after inoculation. Relative density of goblet cells and glycoproteins were determined by Alcian blue periodic acid-Schiff staining and periodic acid-Schiff staining, respectively. Intestinal development parameters were also evaluated. Cecal contents were extracted, and the composition of cecal microflora was examined by Illumine sequencing in the V3-V4 region of the 16S rRNA gene. Results indicated that E. tenella infection destroyed the structure of cecal tissue and reduced the relative density of goblet cells and glycoproteins. Sequencing analysis indicated that E. tenella infection altered the diversity and composition of cecal microbiota. The populations of Proteobacteria, Enterococcus, Incertae, and Escherichia-Shigella decreased, and those of Bacteroidales and Rikenella significantly increased in the infected group compared with those in the control group. Hence, the pathological damage caused by E. tenella infection is associated with cecal microbiota dysbiosis, and this finding may be used to develop an alternative measure for alleviating the effect of coccidiosis on the poultry industry.

Eukaryotic elongation factor 2 is involved in the anticoccidial action of diclazuril in the second-generation merozoites of Eimeria tenella.

Eimeria tenella, an obligate intracellular parasite, can actively invade the cecal epithelial cells of chickens and cause severe enteric disease. Eukaryotic elongation factor 2 (eEF2) plays a major role in protein synthesis and cell survival. This study aims to explore the exact mechanisms underlying diclazuril inhibition in second-generation merozoites of E. tenella. The eEF2 cDNA of the second-generation merozoites of E. tenella (EtEF2) was cloned by reverse transcriptase polymerase chain reaction and rapid amplification of cDNA ends. Diclazuril-induced expression profiles of EtEF2 were also analyzed. The cloned full-length cDNA (2893 bp) of the EtEF2 nucleotide sequence encompassed a 2499 bp open reading frame (ORF) that encoded a polypeptide of 832 residues with an estimated molecular mass of 93.12 kDa and a theoretical isoelectric point of 5.99. The EtEF2 nucleotide sequence was submitted to the GenBank database with the accession number KF188423. The EtEF2 protein sequence shared 99 % homology with the eEF2 sequence of Toxoplasma gondii (GenBank XP_002367778.1). The GTPase activity domain and ADP-ribosylation domain were conserved signature sequences of the eEF2 gene family. The changes in the transcriptional and translational levels of EtEF2 were detected through quantitative real-time PCR and Western blot analyses. The mRNA expression level of EtEF2 was 2.706 fold increases and the protein level of EtEF2 was increased 67.31 % under diclazuril treatment. In addition, the localization of EtEF2 was investigated through immunofluorescence assay. Experimental results demonstrated that EtEF2 was distributed primarily in the cytoplasm of second-generation merozoites, and its fluorescence intensity was enhanced after diclazuril treatment. These findings indicated that EtEF2 may have an important role in understanding the signaling mechanism underlying the anticoccidial action of diclazuril and could be a promising target for novel drug exploration.

Hydroxide-bridged five-coordinate DyIII single-molecule magnet exhibiting the record thermal relaxation barrier of magnetization among lanthanide-only dimers.

A hydroxide-bridged centrosymmetric DyIII dimer with each DyIII being five-coordinated has been synthesized using bulky hindered phenolate ligands. Magnetic studies revealed that this compound exhibits a slow magnetic relaxation of a single-ion origin together with a step-like magnetic hysteresis of the magnetic coupled cluster. The thermal relaxation barrier of magnetization is 721 K in the absence of a static magnetic field, while the intramolecular magnetic interaction is very large among reported 4f-only dimers. CASSCF calculations with a larger active space were performed to understand the electronic structure of the compound. The thermal relaxation regime and the quantum tunneling regime are well separated, representing a good model to study the relaxation mechanism of SMMs with intramolecular Dy-Dy magnetic interactions.

[Application of ICP-MS to Detect Rare Earth Elements in Three Economic Macroalgaes in China].

In order to investigate the content and distribution of rare earth elements (REE) in main economic macroalgaes in our country, fifteen rare earth elements in three economic macroalgaes (including 30 samples of kelp, 30 samples of laver and 15 samples of Enteromorpha) were detected using ICP-MS method. Results showed that the total content of REE in different species of macroalgaes was different. The highest total content of REE was in Enteromorpha (16,012.0 ng · g⁻¹), while in kelp and laver, the total REE was similar for two macroalgaes (3887.4 and 4318.1 ng · g⁻¹ respectively). The content of fifteen rare earth elements in kelp ranged from 7.9 to 1496.4 ng · g⁻¹; in laver, it ranged from 8.2 to 1836.6 ng · g⁻¹. For Enteromorpha, the concentration of 15 rare earth elements were between 19.2 and 6014.5 ng · g⁻¹. In addition, the content and distribution of different rare earth elements in different macroalgaes was also different. For kelp, the highest content of REE was Ce (1 496.4 ng · g⁻¹), and the second was La (689.1 ng · g⁻¹). For laver, the highest was Y (1836.6 ng · g⁻¹), and the second was Ce (682.2 ng · g⁻¹). For Enteromorpha, the highest was Ce (6014.5 ng · g⁻¹), and the second was La (2902.9 ng · g⁻¹). Present results also showed that three macroalgaes accumulated the light rare earth elements much more than the high rare earth elements. The light rare earth elements occupied 90.9%, 87.3% and 91.1% for kelp, laver and Enteromorpha respectively. The result that the Enteromorpha had high content of rare earth elements could provide important support for opening new research directions for the utilization of Enteromorpha.

Effect of craniotomy on oxidative stress and its effect on plasma L-carnitine levels.

OBJECTIVE: to investigate the impact of craniotomy on oxidative stress and its effect on levels of plasma L-carnitine (LC). METHODS: plasma levels of reactive oxygen species, superoxide dismutase (SOD), glutathion peroxidase (GSH-Px), catalase (CAT), total antioxidative capacity (T-AOC), and thiobarbituric acid reactive substances (TBARS) were measured in 34 patients (26 males and 8 females, mean age 47.7 ± 6.7 years) before and after craniotomy. Plasma levels of LC, acetyl-L-carnitine (ALC), and propionyl-L-carnitine (PLC) were also measured before and after the craniotomy. RESULTS: the plasma concentrations of SOD, GSH-Px, CAT, and T-AOC within the first 4 h after craniotomy were lower than their baseline values (P < 0.05). There were no statistically significant differences in the mean plasma levels of SOD, GSH-Px, CAT, or T-AOC between the baseline and 24 h post-operative values. The level of TBARS at 4 h after the craniotomy was lower than the pre-operative level (P < 0.05), but the 24 h post-operative value was similar to the baseline concentration (P > 0.05). Plasma levels of LC, ALC, and PLC were lower after the craniotomy (P < 0.05), but these levels returned to the baseline levels 24 h after the operation. CONCLUSIONS: craniotomy and the associated procedures for surgery/anesthesia temporarily reduce antioxidant activity and plasma levels of L-carnitine.

[Process monitoring of dissolution of valsartan and hydrochlorothiazide tablets by fiber-chemical sensor assisted by mathematical separation model of linear equations].

A method for on-line monitoring the dissolution of Valsartan and hydrochlorothiazide tablets assisted by mathematical separation model of linear equations was established. UV spectrums of valsartan and hydrochlorothiazide were overlapping completely at the maximum absorption wavelength respectively. According to the Beer-Lambert principle of absorbance additivity, the absorptivity of Valsartan and hydrochlorothiazide was determined at the maximum absorption wavelength, and the dissolubility of Valsartan and hydrochlorothiazide tablets was detected by fiber-optic dissolution test (FODT) assisted by the mathematical separation model of linear equations and compared with the HPLC method. Results show that two ingredients were real-time determined simultaneously in given medium. There was no significant difference for FODT compared with HPLC (p > 0.05). Due to the dissolution behavior consistency, the preparation process of different batches was stable and with good uniformity. The dissolution curves of valsartan were faster and higher than hydrochlorothiazide. The dissolutions at 30 min of Valsartan and hydrochlorothiazide were concordant with US Pharmacopoeia. It was concluded that fiber-optic dissolution test system assisted by the mathematical separation model of linear equations that can detect the dissolubility of Valsartan and hydrochlorothiazide simultaneously, and get dissolution profiles and overall data, which can directly reflect the dissolution speed at each time. It can provide the basis for establishing standards of the drug. Compared to HPLC method with one-point data, there are obvious advantages to evaluate and analyze quality of sampling drug by FODT.

Cytogenetic and molecular identification of small-segment chromosome translocation lines from wheat-rye substitution lines to create wheat germplasm with beneficial traits.

Intergeneric crop plant hybrid lines with small-segment chromosome translocations are very useful in plant genetic research and breeding. In this study, to create small-segment chromosome translocations with beneficial agronomic characters, the progeny of wheat-rye substitution lines 5R/5A and 6R/6A were selected from generations F2 to F5 for rye-specific characteristics. A PCR primer and specific simple sequence repeat marker for rye were used in F5 populations to detect rye chromatin and to amplify a specific chromosome band in six translocation lines (06-6-5, 06-6-6, 06-6-9, 6-26-1, 7-23, and 7-33). Fragment pSc119.1 cloned from 7-33 had 99% homology with the big ear gene sequence (GenBank AF512607.1) in wheat. The six lines were further characterized via pollen mother cell meiosis analysis for genetic stability, and chromosome C-banding and genomic in situ hybridization for rye chromatin. The results show that line 7-33 was still within the 5R/5A substitution lines and possessed the big ear gene. The other lines all contained small-segment rye chromosome translocations. The results indicated that substitution line hybridization is an effective method for creating small-segment chromosome translocations with useful agronomic traits. Trials for these six wheat-rye translocation lines are justified because they possess many important stably-inherited agronomic characters, including disease resistance and improved yield.

Arsenic Species in Edible Seaweeds Using In Vitro Biomimetic Digestion Determined by High-Performance Liquid Chromatography Inductively Coupled Plasma Mass Spectrometry.

Arsenite [As (III)], arsenate [As (V)], methylarsonate (MMA), and dimethylarsinate (DMA) in five edible seaweeds (the brown algae Laminaria japonica, red algae Porphyra yezoensis, brown algae Undaria pinnatifida, brown algae Hizikia fusiformis, and green algae Enteromorpha prolifera) were analyzed using in vitro digestion method determined by high-performance liquid chromatography inductively coupled plasma mass spectrometry. The results showed that DMA was found in the water extracts of all samples; As (III) were detected in L. japonica and U. pinnatifida and about 23.0 and 0.15 mg/kg of As (V) were found in H. fusiformis and E. prolifera respectively. However, after the gastrointestinal digestion, As (V) was not detected in any of the five seaweeds. About 0.19 and 1.47 mg/kg of As (III) was detected in the gastric extracts of L. japonica and H. fusiformis, respectively, and about 0.31 and 0.10 mg/kg of As (III) were extracted from the intestinal extracts of Porphyra yezoensis and U. pinnatifida, respectively. The present results successfully reveal the differences of As species and levels in the water and biomimetic extracts of five edible seaweeds. The risk assessment of the inorganic arsenic in the five edible seaweeds based on present data showed almost no hazards to human health.

7-[(7S)-7-Aza-niumyl-5-aza-spiro-[2.4]hept-5-yl]-8-chloro-6-fluoro-1-[(1S,2R)-2-fluoro-cyclo-prop-yl]-4-oxo-1,4-dihydroquinoline-3-carboxyl-ate methanol monosolvate.

Sitafloxacin is a newly developed fluoro-quinolone anti-bacterial drug. The crystal studied, C(19)H(18)ClF(2)N(3)O(3)·CH(3)OH, consists of one mol-ecule of sitafloxacin and one methanol solvent mol-ecule. The mol-ecule of sitafloxacin is a zwitterion with a protonated primary amine group and a deprotonated carboxylate group. The cyclopropane ring and the CO(2) group make dihedral angles of 79.5 (3) and 35.4 (4)°, respectively, with the fused ring system. The supra-molecular structure is defined by N-H⋯O and O-H⋯O hydrogen bonds.

Sorption behavior of nonylphenol on marine sediments: effect of temperature, medium, sediment organic carbon and surfactant.

The sorption behavior of nonylphenol (NP, a toxic endocrine disruptor) on marine sediments was studied in detail through a series of kinetic and thermodynamic sorption experiments. The results showed that the sorption reaction of NP on marine sediments reached equilibrium in 1.5 h and that it accorded well with the non-linear Ho-McKay pseudo-second-order model. The sorption isotherms of NP on H2O-treated sediments could be well described by the Linear isotherm model, while the sorption isotherm on H2O2-treated sediments could be well fitted with the Freundlich isotherm model. A positive correlation was found between the distribution coefficient (Kd) and the sediment organic carbon contents. The medium salinity showed a positive relation with the Kd and a negative relation with the dissolved organic carbon (DOC). Hexadecyl trimethyl ammonium bromide (CTAB) enhanced the sorption amount of NP the most, while sodium dodecylbenzenesulfonate (SDBS) enhanced it the least. The sorption reaction of NP on marine sediments was a spontaneous, physical, exothermic and entropy-decreasing process.

[Comparison of the models of acute hypoxia and hypoxic-ischemia in newborn piglets].

OBJECTIVE: To compare the newborn piglet models of hypoxic ischemic brain damage in hypoxia and hypoxia combined with occlusion of both carotid arteries. METHODS: Twenty four 7-day-old piglets were divided into two groups. Group H: mechanical ventilation with low concentration of oxygen, Group HI: mechanical ventilation with low concentration of oxygen combined with occlusion of both carotid arteries. The piglets were inhaled with 10%, 8%, and 6% low-concentration oxygen for 30 min, and grouped into mild, moderate, and severe hypoxia ones. The changes of physiological parameter, cerebral blood flow and cerebral oxygen perfusion were detected. RESULTS: There were no significant differences in blood gas analysis of oxygen saturation, blood lactic acid and pH between the two groups(P>0.05).The mean arterial pressure of severe hypoxia in HI was significantly lower than in H (P<0.05). The cerebral blood flow in H and HI was relatively stable after different degrees of hypoxia. As compared with the cerebral blood flow perfusion in group H and HI, there were no significant differences between them(P>0.05). The cerebral oxygen perfusion in H and HI was significantly descent after different degrees of hypoxia(P<0.05). As compared with the cerebral oxygen perfusion in groups H and HI, there were no significant differences between them. CONCLUSION: H and HI have the same effect on physiological parameter, cerebral volume and cerebral oxygen perfusion of newborn piglets. The mechanical ventilation with low concentration of oxygen to newborn piglets can develop the HIBD model, it is not necessary to occlude carotid arteries.

[Clinicopathological significance of cytotoxic lymphocytes in breast cancer and draining lymph nodes].

OBJECTIVE: To analyze retrospectively the quantity and activation status of the tumor infiltrating cytotoxic lymphocytes in breast cancer and the draining lymph nodes, and its relation to the clinical pathological significance. METHODS: Seventy-four breast cancer samples with their corresponding axillary lymph nodes were histologically typed and staged. Cytotxic lymphocytes were analyzed by immunohistochemistry with the monoclonal antibodies against CD8, CD56, granzyme B and perforin. RESULTS: The number of infiltrating CD8(+) T cells in the cancerous interstitial tissue were much higher than that in the tumor parenchyma. Compared with the metastatic tumor samples, the CD8(+) T cells were more intensive in the primary tumors (35.7 +/- 16.0 vs. 23.7 +/- 9.6). The tumor infiltrating CD8(+) T cells of patients with 5 years survivals were more than that of the dead cases in this follow-up series death (32.9 +/- 14.1 vs. 20.1 +/- 9.9). There was no significant difference of activated tumor infiltrating cytotoxic T cell analyzed by using the activation marker granzyme B(+) and there was also no significant correlation between the intensity of CD8(+), CD56(+) cells and the clinicopathological stages. However, percentages of the activated cytotoxic lymphocytes in Stage I groups were significantly higher than those in stage III and IV. Moreover, the number of perforin(+) cells was significantly less than that of granzyme B(+) cells, particularly in the cancerous tissue, indicating a dysfunctional status of tumor infiltrating cytotoxic lymphocytes. CONCLUSIONS: Activated cytotoxic lymphocytes may play a significant role against the tumor progression and is associated with a favorable prognosis to some extent. However, a putative dysfunctional status of cytotoxic lymphocytes at tumor site may compromise the host immunity against cancer.

[Detecting cerebral hypoxia-ischemia of newborn piglets using spatially-resolved near-infrared spectroscopy].

As a non-invasive technique for measuring tissue oxygenation, near-infrared spectroscopy (NIRS) has increasing applications in detecting cerebral hypoxia-ischemia. The authors, introduced the basic principle of the NIRS oximeter developed independently by our group (TSAH-100). The authors achieved the optimal coupling between the probe and the detected cerebral tissue. The present study investigated different regional oxygen saturations of brain (rSO2) measured non-invasively by NIRS, arterial blood oxygen saturation (SaO2) measured invasively by blood gas analysis and physiological parameters in newborn pigs with different hypoxia, in order to prove if the non-invasively cerebral rSO2 can indicate cerebral oxygenation status in clinical practice. Using this oximeter, cerebral rSO2 of 28 newborn piglets under different oxygenation status was detected. After mechanical ventilation and inhalation of 8%-17% oxygen for 30 min in the newborn pigs, the pigs were grouped according to the inhalation of oxygen. With the inhalation of 13%-17% oxygen was mild hypoxia group, with 10%-13% was moderate hypoxia group, and with 8%-10% was severe hypoxia group. There were 4 animals in mild hypoxia group, 8 animals in moderate hypoxia group, 12 animals in severe hypoxia group and 4 animals were in the normal control group. The physiological parameters were monitored during the experiment. The SaO2 were invasively measured by blood gas analysis after the experiment. The results indicate that both rSO2 and SaO2 decreased after different degree of hypoxia and there was a good correlation between cerebral rSO2 non-invasively measured by NIRS and SaO2 invasively measured by blood gas analysis (p<0.001). Cerebral rSO2 was also consistent with the degree of hypoxia and the changes in physiological parameters after hypoxia. The arterial pH and the mean arterial pressure (MAP) in the severe hypoxia group was lower than that in the control group (p<0.05). The blood lactic acid in the severe hypoxia group was higher than that in the control group (p<0.05). Thus, the rSO2 can accurately and directly indicate cerebral oxygenation status and can also replace the SaO2 invasively measured by blood gas analysis. Cerebral hypoxia-ischemia can be non-invasively and conveniently diagnosed using NIRS.

[Correlation of brain hypoxia at different degrees with brain function and brain damage investigated using near infrared spectroscopy].

OBJECTIVE: To study correlation of brain hypoxia of different degrees with brain function and damage. METHODS: The brain regional oxygen saturation (rSO2) was determined by using a non-invasive near infrared spectroscopy (NIRS) technique in 15 piglets; the piglets were subjected to inhale 3% - 11% oxygen-nitrogen mixed gas through mechanical ventilation for 30 min. The piglets were divided into groups according to the level of brain rSO2 (i.e. < 30%, 30% - 35%, 35% - 40%, and 40% - 50%), and the data were compared with those of the control group (rSO2 > 60%). Changes of brain function were detected through amplitude and frequency of EEG waves and signal complexity. The piglets were sacrificed via decapitation 72 h after brain damage, and then histopathological and ultrastructural examinations were performed on cerebral cortex and hippocampal CA1 area. RESULTS: In the group with rSO2 > 40%, the mean arterial pressure (MAP) after hypoxia was (56 +/- 0.00) mm Hg (1 mm Hg = 0.133 kPa), the blood lactic acid (LA) was (2.3 +/- 1.2) mmol/L, the EEG findings were within normal range, and there was no change in brain tissue ultrastructure. In the group with brain rSO2 = 30% approximately 40%, the MAP was (73 +/- 8) mm Hg, the LA was (8.2 +/- 3.9) mmol/L, the EEG waves showed decreased amplitude, frequency and complexity, but restored to some extent after hypoxia. The brain tissue ultrastructure showed damages to the cerebral cortex and neuron mitochondria at hippocampal CA1 area. In the group with brain rSO2 < 30%, the MAP was (35 +/- 0) mm Hg, the LA was (12 +/- 2) mmol/L, the EEG showed decreased amplitude, frequency, and complexity of signals compared with those of the normal control group, and was difficult to restore after hypoxia in some of the piglets; the brain tissue ultrastructure appeared to be similar to the changes seen with high-degree swollen cerebral cortex and neuron mitochondria at hippocampal CA1 area. CONCLUSION: Different degrees of hypoxia had different influence on brain function and brain damage. The lower the brain rSO2, the more severe the damages to the brain and its function. The rSO2 of brain tissues detected with noninvasive NIRS can reflect brain injury and its severity during cerebral anoxia.

[Spectral study of voltage sensitive dye di-4-ANEPPS].

This study investigated the absorption spectrum and the fluorescence spectrum of rabbit hearts stained with the voltage sensitive dye (di-4-ANEPPS). The results suggested that the optical absorption of tissue with the dye was higher than that of the control group, and there were significant differences between the experimental group and control group in the range of 450-550 nm. It was also indicated that the maximum absorption peak of the dye in tissues was at (479.25 +/- 0.44) nm. Additionally, the different peaks of fluorescence emission spectra from the atriums, ventricles and aorta were originally found by testing the five parts of rabbit hearts with the dye. Their relative intensities were related to the distribution concentrations of the dye. Meanwhile, the peaks of excitation spectra and fluorescence emission spectra were determined by examining the three-dimensional and two-dimensional fluorescence spectra using ventricles and atriums with the dye. Based on the discrepancy of rest membrane voltages between ventricles and atriums, the best wavelength ranges of excitation light and emissions light of optical mapping were determined by the shifts of the dye in emission spectra with excitation at different wavelengths. These results offer a theoretical foundation for the design of a cardiac optical mapping system.