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1.
Aquac Nutr ; 2024: 6337005, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38298207

RESUMO

The effects of plant protein sources (PPSs) on the health of the liver and intestine of the largemouth bass, Micropterus salmoides, were compared to verify the potential damaging effects of dietary fiber (DF). A diet containing 55% fish meal (FM) was used as the control. The test diets contained 25% soybean meal (SBM), rapeseed meal (RSM), cottonseed meal, or peanut meal, and the FM content was decreased to 30%. The protein and lipid contents of these five diets were balanced by casein and oil. Fish were raised for 8 weeks. The fish fed the diet containing PPS showed a trend of decreasing growth and apparent digestibility coefficients. The contents of total bile acid, lipid, and collagen in the liver were increased, and the mRNA expression levels of genes encoding inflammatory factors and enzymes involved in de novo fatty acid synthesis and bile acid synthesis were upregulated. Both the lipid and collagen contents in the liver were positively correlated with the DF content in the diet significantly. Morphology and histology showed reduced liver size, hepatic steatosis, and fibrosis in fish fed diets containing PPS. The lowest hepatosomatic index was observed in fish fed the SBM diet, and the most severe damage was observed in fish fed the RSM diet. No obvious histological abnormalities were observed in the hindgut. The bile acid profile in the liver could be used to distinguish the types of PPS very well by Fisher discriminant analysis. These results indicated that 25% of each of the four PPSs in the diet exceeded the tolerance range of largemouth bass and caused liver damage, which might be mediated by bile acid. DF in PPS might be an important agent contributing to liver damage.

2.
Aquac Nutr ; 2022: 6173245, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36860455

RESUMO

The concentration of butyric acid in the intestine increased with the increase in the content of fermentable dietary fibre; however, the potential physiological impact of a high dose of butyric acid on fish has not been sufficiently studied. The aim of this study was to investigate the effect of two dosages of butyric acid on the growth and health of the liver and intestine of the largemouth bass (Micropterus salmoides). Sodium butyrate (SB) was added to the diet at 0 g/kg (CON), 2 g/kg (SB2), and 20 g/kg (SB20), and the juvenile largemouth bass were fed to apparent satiation for 56 days. No significant difference was observed in the specific growth rate or hepatosomatic index among the groups (P > 0.05). The concentration of ß-hydroxybutyric acid in the liver, the activities of alanine aminotransferase, aspartate aminotransferase, and alkaline phosphatase, and the concentrations of triglyceride and total cholesterol in serum increased significantly in the SB20 group compared to the CON group (P < 0.05). The relative expression of fas, acc, il1b, nfkb, and tnfa in the liver of the SB20 groups was also significantly higher than that of the CON group (P < 0.05). The above indicators in the group SB2 had similar change tendencies. The expression of nfkb and il1b in the intestine of both the SB2 and SB20 groups was significantly downregulated compared with that in the CON group (P < 0.05). The size of hepatocytes was enlarged, and the intracellular lipid droplets and the degree of hepatic fibrosis were increased in the SB20 group compared to the CON group. There was no significant difference in intestinal morphology among the groups. The above results indicated that neither 2 g/kg nor 20 g/kg SB had a positive effect on the growth of largemouth bass, while a high dosage of SB induced liver fat accumulation and fibrosis.

3.
Fish Physiol Biochem ; 2022 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-36454392

RESUMO

In a study on the anti-nutritional effect of dietary fiber, it was noticed that a high-pectin diet (PEC diet) caused growth retardation, hepatic cholestasis, steatosis, fibrosis, and enteritis accompanied by decreased glycocholic acid (GCA) in Pelteobagrus fulvidraco. This study was conducted to investigate the potential alleviating effects of supplementation with GCA. A PEC diet and a diet supplemented with 0.6 g kg-1 GCA based on the PEC diet (named the GCA diet) were formulated and randomly fed to juvenile Pelteobagrus fulvidraco. Compared to fish that were fed the PEC diet for 7 days, the GCA content in liver increased significantly in fish fed the GCA diet, the incidence of abnormal liver color, gallbladder somatic index (GBSI), total bile acid concentration in serum and liver, and the expression of arnesoid X receptor gene (fxr) upregulated and genes involved in bile acid (BA) synthesis and uptake in liver decreased significantly. After 56 days, the SGR, the expression of fxr and genes involved in BA synthesis and transportation in the liver, the serum content of total bilirubin, total protein, and globulin were significantly higher, while the hepatosomatic index, GBSI, liver lipid and collagen content, and the incidence of distal intestine tissue damage were lower in fish fed the GCA diet than in those fed the PEC diet. These results suggested that GCA improved growth performance and alleviated hepatic cholestasis and tissue damage to the liver and intestine induced by a high-pectin diet, which might occur through activating FXR.

4.
Epidemiol Infect ; 149: e196, 2021 08 09.
Artigo em Inglês | MEDLINE | ID: mdl-34369328

RESUMO

This study aimed to evaluate the performance of Cobas human papillomavirus (HPV) test in cervical cancer screening. A total of 3442 women aged ⩾20 years used Cobas HPV and hybrid capture 2 (HC2) tests were included in this study. Women with any positive result were examined by liquid-based cytology (LBC) test. Then subjects with abnormal LBC or positive Cobas HPV16/18 were further checked by colposcopy to observe the visible lesions to perform the pathological examination. Of these 3442 women, 328 cases were Cobas HPV positive, and the positive rate was 9.53% (95% confidence interval (CI) 8.50-10.53). The positive rate of HPV16, HPV18, and other 12 types of high-risk HPV were 1.54% (95% CI 1.12-1.95), 0.55% (95% CI 0.30-0.80), and 7.44% (95% CI 6.56-8.32), respectively. The coincidence rate of Cobas HPV test and HC2 test was 90% (95% CI 89.00-91.00; Kappa = 0.526) in the primary screening. Age had a non-linear relationship with Cobas HPV positive rate (χ2 = 4.240, P = 0.040) and HPV16/18 typing positive rate (χ2 = 6.610, P = 0.010). Compared with the LBC test, the Cobas HPV test had higher sensitivity when detecting patients with high cervical intraepithelial neoplasia (CIN2+ and CIN3+).


Assuntos
Detecção Precoce de Câncer , Papillomaviridae/isolamento & purificação , Infecções por Papillomavirus/diagnóstico , Neoplasias do Colo do Útero/diagnóstico , Adulto , China , Feminino , Humanos , Pessoa de Meia-Idade , Papillomaviridae/classificação , Migrantes
5.
Fish Physiol Biochem ; 47(6): 2015-2025, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34709495

RESUMO

To reveal the impact of dietary fiber (DF) on the bile acid (BA) profiles of fish, yellow catfish (Pelteobagrus fulvidraco) were fed a diet containing 300 g kg-1 dextrin (CON diet, control) or pectin (a type of soluble DF, PEC diet) for 7 days, and then the BA profiles were analyzed by UHPLC-MS/MS. A total of 26 individuals of BAs were detected in the fish body, with 8, 10, 14, and 22 individuals of BAs detected in the liver, serum, bile, and hindgut digesta, respectively. The conjugated BAs (CBAs) of fish were dominated by taurine CBAs (TCBAs). The concentrations of free BAs (FBAs) and the value of FBAs/CBAs in the bile of fish fed the PEC diet were nearly 5 and 7 times higher, respectively than those in fish fed the CON diet. The value of glycine CBAs/TCBAs in the liver, serum and bile of fish fed the PEC diet was significantly lower, and in the hindgut digesta was higher than that of fish fed the CON diet (P < 0.05). These results suggested that dietary pectin greatly changed the BA profiles of Pelteobagrus fulvidraco, attributed to inhibition of reabsorption of BAs. Therefore, attention should be paid to the impact on BA homeostasis when replacing fishmeal with DF-rich plant ingredients in the fish diet.


Assuntos
Ácidos e Sais Biliares , Peixes-Gato , Pectinas/administração & dosagem , Animais , Ácidos e Sais Biliares/análise , Dieta/veterinária , Fígado , Espectrometria de Massas em Tandem , Taurina
6.
Angew Chem Int Ed Engl ; 60(45): 24054-24058, 2021 Nov 02.
Artigo em Inglês | MEDLINE | ID: mdl-34519405

RESUMO

Natural hydrogen (H2 ) has gained considerable attentions as a renewable energy resource to mitigate the globally increasing environmental concerns. Low-temperature serpentinization (<200 °C) as a typical water-rock reaction is a major source of the natural H2 . However, the reaction mechanism and the controlling step to product H2 remained unclear, which hinders the further utilization of natural H2 . Herein, we demonstrated that the H2 production rate could be determined by the Fe(OH)2 oxidation during low-temperature serpentinization. Moreover, the co-existence of Ni2+ could largely enhance the H2 production kinetics. With the addition of only 1 % Ni2+ , the H2 production rate was remarkably enhanced by about two orders of magnitude at 90 °C. D2 O isotopic experiment and theoretical calculations revealed that the enhanced H2 production kinetics could be attributed to the catalytic role of Ni2+ to promote the reduction of H2 O.

7.
Fish Physiol Biochem ; 40(6): 1783-92, 2014 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-25074470

RESUMO

To confirm the existence of the tight junction (TJ) in middle intestine and obtain the genetic information of Claudin-3, Claudin-15a, Claudinb and Claudinc of grass carp, we observed the physical structure of TJ by transmission electron microscopy and cloned the partial cDNAs of the four Claudins using reverse transcriptase PCR technique. The four partial cDNAs consist of 1,261, 490, 776 and 662 bp encoded 131, 150, 195 and 171 amino acids, respectively. Homology analysis showed that the grass carp Claudin shared high homology with other teleost species, especially with Danio rerio and Carassius auratus. Multi-alignments of the four Claudin amino acid sequences have seen the two conserved cysteines existing in the first extracellular loop of Claudin-15a, Claudinb and Claudinc, and the sequence diversity of the four Claudins mainly lies within the C-terminal tails, which usually end with the -Y-V motif, except the -F-V motif in Claudinb. Tissue distributions of the four Claudins were measured by applying quantitative real-time PCR technique. Results showed that Claudin-3 was mainly expressed in liver and middle intestine and Claudinb was ubiquitously expressed with a higher expression in middle intestine while Claudin-15a and Claudinc were mainly expressed in middle intestine. Our study revealed the existence of the TJ in the middle intestinal and obtained the genetic information of Claudin-3, Claudin-15a, Claudinb and Claudinc of grass carp, aiming to found the molecular biology basis for the further study of the intestinal barrier function of grass carp.


Assuntos
Carpas/metabolismo , Claudinas/metabolismo , Clonagem Molecular , Regulação da Expressão Gênica/fisiologia , Intestinos/fisiologia , Junções Íntimas/fisiologia , Sequência de Aminoácidos , Animais , Sequência de Bases , Claudinas/genética , Intestinos/ultraestrutura , Dados de Sequência Molecular , Distribuição Tecidual
8.
Sci Rep ; 14(1): 11996, 2024 05 25.
Artigo em Inglês | MEDLINE | ID: mdl-38796638

RESUMO

Different from the Qaidam basin with about 320 billion m3 microbial gas, only limited microbial gases were found from the Junggar basin with similarly abundant type III kerogen. To determine whether microbial gases have not yet identified, natural gas samples from the Carboniferous to Cretaceous in the Junggar basin have been analyzed for chemical and stable isotope compositions. The results reveal some of the gases from the Mahu sag, Zhongguai, Luliang and Wu-Xia areas in the basin may have mixed with microbial gas leading to straight ethane to butane trends with a "dogleg" light methane in the Chung's plot. Primary microbial gas from degradation of immature sedimentary organic matter is found to occur in the Mahu sag and secondary microbial gas from biodegradation of oils and propane occurred in the Zhongguai, Luliang and Beisantai areas where the associated oils were biodegraded to produce calcites with δ13C values from + 22.10‰ to + 22.16‰ or propane was biodegraded leading to its 13C enrichment. Microbial CH4 in the Mahu sag is most likely to have migrated up from the Lower Wuerhe Formation coal-bearing strata by the end of the Triassic, and secondary microbial gas in Zhongguai and Beisantan uplifts may have generated after the reservoirs were uplifted during the period of the Middle and Late Jurassic. This study suggests widespread distribution of microbial gas and shows the potential to find large microbial gas accumulation in the basin.


Assuntos
Metano , Gás Natural , Metano/análise , Metano/metabolismo , Gás Natural/análise , Gases/metabolismo , Gases/análise , China , Sedimentos Geológicos/microbiologia , Sedimentos Geológicos/química , Sedimentos Geológicos/análise , Isótopos de Carbono/análise
9.
Sci Adv ; 10(28): eadm7773, 2024 Jul 12.
Artigo em Inglês | MEDLINE | ID: mdl-38985875

RESUMO

The release of phosphorous (P) via chemical weathering is a vital process that regulates the global cycling of numerous key elements and shapes the size of the Earth's biosphere. It has long been postulated that global climate should theoretically play a prominent role in governing P weathering rates. Yet, there is currently a lack of direct evidence for this relationship based on empirical data at the global scale. Here, using a compilation of temperature and P content data of global surface soils (0 to 30 cm), we demonstrate that P release does enhance at high mean annual surface temperatures. We propose that this amplification of nutrient supply with warming is a critical component of Earth's natural thermostat, and that this relationship likely caused expanded oceanic anoxia during past climate warming events. The potential acceleration of phosphorus loss from soils due to anthropogenic climate warming may pose threats to agricultural production, terrestrial and marine ecosystems, and alter marine redox landscapes.

10.
Sci Adv ; 10(13): eadk2152, 2024 Mar 29.
Artigo em Inglês | MEDLINE | ID: mdl-38552018

RESUMO

The evolution of oxygen cycles on Earth's surface has been regulated by the balance between molecular oxygen production and consumption. The Neoproterozoic-Paleozoic transition likely marks the second rise in atmospheric and oceanic oxygen levels, widely attributed to enhanced burial of organic carbon. However, it remains disputed how marine organic carbon production and burial respond to global environmental changes and whether these feedbacks trigger global oxygenation during this interval. Here, we report a large lithium isotopic and elemental dataset from marine mudstones spanning the upper Neoproterozoic to middle Cambrian [~660 million years ago (Ma) to 500 Ma]. These data indicate a dramatic increase in continental clay formation after ~525 Ma, likely linked to secular changes in global climate and compositions of the continental crust. Using a global biogeochemical model, we suggest that intensified continental weathering and clay delivery to the oceans could have notably increased the burial efficiency of organic carbon and facilitated greater oxygen accumulation in the earliest Paleozoic oceans.

11.
PNAS Nexus ; 1(4): pgac122, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-36714851

RESUMO

Ocean sulfate concentration might have fluctuated greatly throughout the Earth's history and may serve as a window into perturbations in the ocean-atmosphere system. Coupling high-resolution experimental results with an inverse modeling approach, we, here, show an unprecedented dynamic in the global sulfate reservoir during the Frasnian-Famennian (F-F) boundary event, as one of the "Big five" Phanerozoic biotic crises. Notably, our results indicate that, in a relatively short-time scale (∼200 thousand years), seawater sulfate concentration would have dropped from several mM before the Upper Kellwasser Horizon (UKH) to an average of 235 ± 172 µM at the end of the UKH (more than 100 times lower than the modern level) as the result of evaporite deposition and euxinia, and returned to around mM range after the event. Our findings indicate that the instability in the global sulfate reservoir and nutrient-poor oceans may have played a major role in driving the Phanerozoic biological crises.

12.
Sci Rep ; 12(1): 196, 2022 Jan 07.
Artigo em Inglês | MEDLINE | ID: mdl-34997136

RESUMO

Diamondoid compounds are widely used to reflect thermal maturation of high mature source rocks or oils and oil cracking extents. However, diamondoids and thiadiamondoids were demonstrated to have newly been generated and decomposed in our hydrothermal pyrolysis of crude oil and TSR experiments. Our results show that adamantanes and diamantanes are generated primarily within the maturity range 0.48-2.1% and 1.2-3.0% EasyRo, respectively. Their formation is enhanced and the decomposition of diamantanes obviously lags at elevated temperatures compared with anhydrous experiments. MDI, EAI, DMAI-1, DMDI-2 may serve as reliable maturity proxies at > ca.1.0% EasyRo, and other isomerization indices (TMAI-1, TMAI-2 and DMAI-2) are effective for the highly mature organic matter at EasyRo > 2.0%. The extent of oil cracking (EOC) calculated from the broadly used (3- + 4-) MD method (Dahl et al. in Nature 399:54-56, 1999) is proven to overestimate, especially for highly cracked samples due to the new generation of (3- + 4-) MD. Still, it can be corrected using a new formula at < 3.0% EasyRo. Other diamondoid-related indices (e.g., EAI, DMDI-2, As/Ds, MAs/MDs, DMAs/DMDs, and DMAs/MDs) can also be used to estimate EOC. However, these indices cannot be applied to TSR-altered petroleum. TSR is experimentally confirmed to generate diamantanes and thiaadmantanes at 1.81% EasyRo likely via direct reactions of reduced S species with hydrocarbons and accelerate the decomposition of diamantanes at > 2.62% EasyRo compared with thermal chemical alteration (TCA). More studies are needed to assess specific mechanisms for the formation of thiadiamondoids under natural conditions.

13.
Am J Transl Res ; 14(3): 1737-1741, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35422906

RESUMO

To investigate the efficacy and safety of laparoscopic internal iliac artery temporary occlusion and uterine repair combined with hysteroscopic aspiration in type III cesarean scar pregnancy. 135 cases of cesarean scar pregnancy in Guangzhou Women and Children's Hospital from November 2017 to November 2020 were collected and 32 cases of type III patients were retrospectively analyzed. They were divided into internal iliac artery temporary occlusion (IIATO) group (21 cases), and bilateral uterine artery embolization (UAE) group (11 cases). The general condition, intraoperative bleeding, postoperative complications, and prognosis of the two groups were analyzed. In the IIATO group, the bilateral internal iliac arteries were temporarily blocked with No. 10 silk thread under laparoscopy. The scar pregnancy clearance and repair of the scar were performed after incision. Subsequently, we performed hysteroscopic aspiration. After the operation, the internal iliac artery ligation thread was removed. In the UAE group, the patients were treated with bilateral uterine artery embolization. Laparoscopic uterine scar repair and hysteroscopy aspiration were performed within 24 hours after embolization. There was no significant difference in age, times of pregnancy, times of cesarean section and gestational weeks between the two groups (P>0.05). No significant differences were observed in the diameter of gestational sac or gestational mass and serum human chorionic gonadotropin (ß-hCG) level between the two groups before operation (P>0.05). The operations were successfully completed in 32 patients, and intraoperative blood loss was 67.14±32.78 ml and 71.35±31.56 ml, respectively (P<0.05). The length of hospital stay was 5.14±0.32 day and 4.97±0.21 day, respectively. No peri-procedural bleeding occurred and no secondary surgeries were required. Laparoscopic internal iliac artery temporary occlusion and uterine repair combined with hysteroscopic aspiration is an effective and safe treatment for type III cesarean scar pregnancy, with less postoperative complications and better protection of fertility function for patients.

14.
Biomed Pharmacother ; 134: 111135, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33352448

RESUMO

Currently, the clinical treatment of preterm birth, mainly using uterine contraction inhibitors, does not fundamentally reduce the incidence of premature birth (PTB). Premature cervical ripening is an important factor in PTB. We previously found that nicotine-treated pregnant murine had significant cervical resistance to stretch and higher collagen cross-links compared to the control animals, and nicotine prolonged gestation and inhibited cervical ripening. However, the regulatory effects of nicotine on premature cervical ripening and its role in PTB remain unclear. To investigate the effects of nicotine on cervical TGF-ß1/Smad3 pathway and fibroblast-myofibroblast differentiation regulated by this pathway in PTB-like models. Intraperitoneal injection with 15 µg lipopolysaccharide (LPS) in 200 µl PBS into pregnant mice was used to induce the PTB-like model. Mice were randomly divided into four groups: control group, LPS-treated group, LPS + Nicotine co-treated group and LPS + Nicotine+α-BGT co-treated group. Pregnancy outcomes were monitored. The collagen content was assessed by Picrosirius red staining. Expressions of genes and proteins in the TGF-ß/Smad3 pathway were detected by double immunofluorescence staining and quantitative Real-time PCR (qRT-PCR). myofibroblast differentiation were investigated by double immunofluorescence staining and qRT-PCR. Ultrastructures were analyzed by conventional transmission electron microscopy. The rate of PTB and neonatal mortality at birth was significantly higher in the LPS-treated group than in the control group; collagen content also decreased remarkably; the expression of TGF-ß1 in macrophages and p-Smad3 in fibroblasts were reduced; the expression of α-smooth muscle actin (α-SMA, markers for activated fibroblasts) was down-regulated while the expression of calponin and smoothelin (markers for fibroblasts at rest) was up-regulated. Nicotine improved pregnancy outcomes and inhibited collagen degradation, activated the TGF-ß1/Smad3 pathway and promoted cervical fibroblast-myofibroblast differentiation in PTB-like mice; such effects could be reversed by α-bungarotoxin (α-BGT). Nicotine inhibited premature cervical ripening in PTB-like models in relation with up-regulating the TGF-ß/Smad3 pathway and promoting fibroblast to differentiate into myofibroblasts.


Assuntos
Diferenciação Celular/efeitos dos fármacos , Maturidade Cervical/efeitos dos fármacos , Colo do Útero/efeitos dos fármacos , Miofibroblastos/efeitos dos fármacos , Nicotina/farmacologia , Agonistas Nicotínicos/farmacologia , Nascimento Prematuro/prevenção & controle , Proteína Smad3/metabolismo , Fator de Crescimento Transformador beta1/metabolismo , Actinas/metabolismo , Animais , Colo do Útero/metabolismo , Colo do Útero/ultraestrutura , Colágeno/metabolismo , Modelos Animais de Doenças , Feminino , Lipopolissacarídeos , Camundongos Endogâmicos C57BL , Miofibroblastos/metabolismo , Miofibroblastos/ultraestrutura , Fosforilação , Gravidez , Nascimento Prematuro/induzido quimicamente , Nascimento Prematuro/metabolismo , Nascimento Prematuro/patologia , Proteólise , Transdução de Sinais
15.
Biomed Res Int ; 2020: 5373927, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32076607

RESUMO

OBJECTIVE: To demonstrate various benign gynecologic diseases that can be performed by laparoendoscopic single-site surgery (LESS) with conventional laparoscopic instruments. METHOD: Patients with benign gynecologic diseases that need ovarian cystectomy, fallopian tube resection, or myomectomy were divided into experimental group and control group, and perioperative outcomes of these patients were analyzed. RESULTS: From November 2017 to May 2018, 65 LESS gynecological surgeries were performed, among which there were 25 ovarian cystectomies, 28 unilateral fallopian tube resections, and 12 myomectomies. All the surgeries were completed smoothly, and only one surgery needed one more additional port. No patients have severe complications. Operative time, intraoperative blood loss, and perioperative complications have no difference between the two groups. The LESS laparoscopy group had less postoperative pain scores and longer bowel recovering time, compared with the conventional laparoscopy group (<0.05). CONCLUSION: Compared with traditional laparoscopy, LESS surgery with conventional laparoscopic instruments is feasible and safe, but postoperative exhaust time is longer than the control group.


Assuntos
Doenças dos Genitais Femininos/cirurgia , Procedimentos Cirúrgicos em Ginecologia/efeitos adversos , Procedimentos Cirúrgicos em Ginecologia/instrumentação , Hospitais de Ensino , Laparoscopia/efeitos adversos , Laparoscopia/instrumentação , Adulto , China , Cistectomia/instrumentação , Cistectomia/métodos , Feminino , Procedimentos Cirúrgicos em Ginecologia/métodos , Humanos , Laparoscopia/métodos , Pessoa de Meia-Idade , Ovário , Miomectomia Uterina
16.
ACS Omega ; 4(6): 9835-9842, 2019 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-31460074

RESUMO

Methyltrimethyltridecylchromans (MTTCs) are structurally similar to tocopherols, which were identified in large numbers of source rocks and crude oils (Pleistocene to Early Cambrian). The occurrence of MTTCs was widely used as a proxy indicator of paleosalinity in the field of organic geochemistry. However, their origin and geological formation pathway still remain greatly debated. Here, we review the progress made over the past 30 years in the distribution and origin of MTTCs and their applications. Furthermore, we discussed several key points for future studies on MTTCs.

17.
Geobiology ; 17(3): 247-260, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-30629323

RESUMO

By about 2.0 billion years ago (Ga), there is evidence for a period best known for its extended, apparent geochemical stability expressed famously in the carbonate-carbon isotope data. Despite the first appearance and early innovation among eukaryotic organisms, this period is also known for a rarity of eukaryotic fossils and an absence of organic biomarker fingerprints for those organisms, suggesting low diversity and relatively small populations compared to the Neoproterozoic era. Nevertheless, the search for diagnostic biomarkers has not been performed with guidance from paleoenvironmental redox constrains from inorganic geochemistry that should reveal the facies that were most likely hospitable to these organisms. Siltstones and shales obtained from drill core of the ca. 1.3-1.4 Ga Roper Group from the McArthur Basin of northern Australia provide one of our best windows into the mid-Proterozoic redox landscape. The group is well dated and minimally metamorphosed (of oil window maturity), and previous geochemical data suggest a relatively strong connection to the open ocean compared to other mid-Proterozoic records. Here, we present one of the first integrated investigations of Mesoproterozoic biomarker records performed in parallel with established inorganic redox proxy indicators. Results reveal a temporally variable paleoredox structure through the Velkerri Formation as gauged from iron mineral speciation and trace-metal geochemistry, vacillating between oxic and anoxic. Our combined lipid biomarker and inorganic geochemical records indicate at least episodic euxinic conditions sustained predominantly below the photic zone during the deposition of organic-rich shales found in the middle Velkerri Formation. The most striking result is an absence of eukaryotic steranes (4-desmethylsteranes) and only traces of gammacerane in some samples-despite our search across oxic, as well as anoxic, facies that should favor eukaryotic habitability and in low maturity rocks that allow the preservation of biomarker alkanes. The dearth of Mesoproterozoic eukaryotic sterane biomarkers, even within the more oxic facies, is somewhat surprising but suggests that controls such as the long-term nutrient balance and other environmental factors may have throttled the abundances and diversity of early eukaryotic life relative to bacteria within marine microbial communities. Given that molecular clocks predict that sterol synthesis evolved early in eukaryotic history, and (bacterial) fossil steroids have been found previously in 1.64 Ga rocks, then a very low environmental abundance of eukaryotes relative to bacteria is our preferred explanation for the lack of regular steranes and only traces of gammacerane in a few samples. It is also possible that early eukaryotes adapted to Mesoproterozoic marine environments did not make abundant steroid lipids or tetrahymanol in their cell membranes.


Assuntos
Biomarcadores/análise , Eucariotos/metabolismo , Fósseis , Sedimentos Geológicos/química , Água do Mar/química , Northern Territory , Oxirredução
18.
PLoS One ; 11(1): e0148135, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-26820139

RESUMO

Aquatic animals have a close relationship with water, but differences in their symbiotic bacteria and the bacterial composition in water remains unclear. Wild or domestic Chinese mitten crabs (Eriocheir sinensis) and the water in which they live were collected from four sampling sites in Jiangsu and Shanghai, China. Bacterial composition in water, gills or guts of E. sinensis, were compared by high-throughput sequencing using 16S rRNA genes. Analysis of >660,000 sequences indicated that bacterial diversity was higher in water than in gills or guts. Tenericutes and Proteobacteria were dominant phyla in guts, while Actinobacteria, Proteobacteria and Bacteroidetes were dominant in gills and water. Non-metric multidimensional scaling analysis indicated that microbiota from gills, guts or water clearly separated into three groups, suggesting that crabs harbor a more specific microbial community than the water in which they live. The dominant OTUs in crab gut were related to Mycoplasmataceae, which were low in abundance in gills, showing that, like mammals, crabs have body-site specific microbiota. OTUs related to Ilumatobacter and Albimonas, which are commonly present in sediment and seawater, were dominant in gills but almost absent from the sampled water. Considering E. sinensis are bottom-dwelling crustacean and they mate in saline water or seawater, behavior and life cycle of crabs may play an important role in shaping the symbiotic bacterial pattern. This study revealed the relationship between the symbiotic bacteria of Chinese mitten crab and their habitat, affording information on the assembly factors of commensal bacteria in aquatic animals.


Assuntos
Actinobacteria/isolamento & purificação , Bacteroidetes/isolamento & purificação , Braquiúros/microbiologia , Brânquias/microbiologia , Proteobactérias/isolamento & purificação , Simbiose , Microbiologia da Água , Actinobacteria/genética , Actinobacteria/fisiologia , Animais , Bacteroidetes/genética , Bacteroidetes/fisiologia , Braquiúros/fisiologia , China , Microbioma Gastrointestinal , Brânquias/fisiologia , Microbiota , Filogenia , Proteobactérias/genética , Proteobactérias/fisiologia , RNA Ribossômico 16S/genética
19.
Nan Fang Yi Ke Da Xue Xue Bao ; 35(1): 128-30, 2015 Jan.
Artigo em Zh | MEDLINE | ID: mdl-25613627

RESUMO

OBJECTIVE: To investigate the expression of SOX2 in cervical intraepithelial neoplasia (CIN) and cervical cancer and explore its association with the clinical features. METHODS: SOX2 expressions were examined using immunohistochemical method in 10 normal cervical tissue specimens, 36 cervical intraepithelial neoplasia specimens (including 10 cases of grade I, 12 of grade II, and 14 grade III) and 40 cervical cancer specimens (including 21 cases of stage I and 19 of stage II). The correlation between the immunohistochemical results and the clinical features of the patients was analyzed. RESULTS: SOX2 expression was negative in normal cervical tissues, and was positive in 41.6% of CIN specimens (10.0% in CIN I, 41.7% in CIN II, and 64.3% in CIN III) in 82.5% of cervical cancer specimens (78.2% in stage I and 88.2% in stage II). The patients with cervical cancer had a significantly higher positivity rate of SOX2 than normal control group (P<0.05). The positivity rate of SOX2 increased with the evolution of cervical disease. SOX2 protein expression was significantly correlated with the histological grade and lymph node metastasis (P<0.05), but not with the age or clinical stage of the patients (P<0.05). CONCLUSION: SOX2 expression may serve as a useful indicator for evaluating metastasis and malignancy of cervical cancer.


Assuntos
Fatores de Transcrição SOXB1/metabolismo , Displasia do Colo do Útero/metabolismo , Displasia do Colo do Útero/patologia , Humanos , Metástase Linfática , Gradação de Tumores , Estadiamento de Neoplasias , Fatores de Transcrição SOXB1/genética , Displasia do Colo do Útero/genética
20.
Nan Fang Yi Ke Da Xue Xue Bao ; 33(1): 128-30, 2013 Jan.
Artigo em Zh | MEDLINE | ID: mdl-23353172

RESUMO

OBJECTIVE: To investigate the expression of SOX2 in cervical intraepithelial neoplasia (CIN) and cervical cancer and explore its association with the clinical features. METHODS: SOX2 expressions were examined using immunohistochemical method in 10 normal cervical tissue specimens, 36 cervical intraepithelial neoplasia specimens (including 10 cases of grade I, 12 of grade II, and 14 grade III) and 40 cervical cancer specimens (including 21 cases of stage I and 19 of stage II). The correlation between the immunohistochemical results and the clinical features of the patients was analyzed. RESULTS: SOX2 expression was negative in normal cervical tissues, and was positive in 41.6% of CIN specimens (10.0% in CIN I, 41.7% in CIN II, and 64.3% in CIN III) in 82.5% of cervical cancer specimens (78.2% in stage I and 88.2% in stage II). The patients with cervical cancer had a significantly higher positivity rate of SOX2 than normal control group (P<0.05). The positivity rate of SOX2 increased with the evolution of cervical disease. SOX2 protein expression was significantly correlated with the histological grade and lymph node metastasis (P<0.05), but not with the age or clinical stage of the patients (P<0.05). CONCLUSION: SOX2 expression may serve as a useful indicator for evaluating metastasis and malignancy of cervical cancer.


Assuntos
Fatores de Transcrição SOXB1/metabolismo , Displasia do Colo do Útero/metabolismo , Neoplasias do Colo do Útero/metabolismo , Adulto , Idoso , Feminino , Humanos , Pessoa de Meia-Idade , Gradação de Tumores , Estadiamento de Neoplasias , Neoplasias do Colo do Útero/patologia , Displasia do Colo do Útero/patologia
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