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1.
Zhonghua Yi Xue Za Zhi ; 104(18): 1623-1627, 2024 May 14.
Article in Chinese | MEDLINE | ID: mdl-38742350

ABSTRACT

A total of 37 cases of thyroid tumors with pathological features suggestive of DICER1 gene mutation were selected to detect the DICER1 gene and BRAF gene using Sanger sequencing. A total of 10 patients (27.0%) exhibited DICER1 gene mutation all of whom were female with an age of [M(Q1, Q3)] 38.0 (30.5, 47.5) years. All patients had wild-type BRAFV600E gene. The ultrasound examination showed high-low echogenic well-demarcated intra-thyroidal nodules with abundant peripheral and internal blood flow signals in the DICER1 mutated thyroid tumor. The tumor was confined within the thyroid gland, with a diameter of (3.68±1.31) cm. The pathological features are as follows: the majority of tumors are encapsulated, which mainly composed of large follicles rich in colloid and some are small and micro follicles. The nucleus is round and deeply stained or slightly light stained, small to medium-sized, with occasional nuclear grooves and a lack of nuclear pseudoinclusion bodies within the nucleus. Immunohistochemical staining shows that Ki67 proliferation index of approximately 2%-10%. All cases were followed up for 11 to 18 months, and there was no recurrences or distant metastase. This study confirmed that the DICER1 gene mutation is mutually exclusive with the BRAFV600E gene mutation. The thyroid tumor with DICER1 mutation are in big size and are more common in young females with a good prognosis. Cases with the wild-type DICER1 gene may exhibit similar morphological features, and molecular testing is recommended. If somatic DICER1 mutation is confirmed, patients should undergo germline mutation testing to rule out DICER1 syndrome in order to define whether genetic counseling is necessary.


Subject(s)
DEAD-box RNA Helicases , Mutation , Ribonuclease III , Thyroid Neoplasms , Humans , Ribonuclease III/genetics , DEAD-box RNA Helicases/genetics , Thyroid Neoplasms/genetics , Thyroid Neoplasms/pathology , Adult , Middle Aged , Female , Proto-Oncogene Proteins B-raf/genetics , Male
2.
Zhonghua Bing Li Xue Za Zhi ; 53(1): 16-21, 2024 Jan 08.
Article in Chinese | MEDLINE | ID: mdl-38178741

ABSTRACT

Non-neoplastic lesions were added in the 5th edition WHO classification of adrenal cortical tumor based on the recent update, including adrenal rests, adrenal cysts, congenital adrenal hyperplasia and adrenocortical nodular disease. A range of tumor concepts were updated or refined based on tumor cell origin, histopathology, oncology and molecular biology. The most significant nomenclature change in the field of adrenal cortical pathology involves the refined classification of adrenal cortical nodular disease, which now includes sporadic nodular adrenocortical disease, bilateral micronodular adrenal cortical disease, and bilateral macronodular adrenal cortical disease. The 5th edition WHO classification endorses the nomenclature of the HISTALDO classification to help the classification of aldosterone producing adrenal cortical lesions, which uses CYP11B2 immunohistochemistry to identify functional sites of aldosterone production. The 5th edition WHO classification does not change the Weiss and Lin-Weiss-Bisceglia histopathologic criteria for diagnosing adrenal cortical carcinomas, and underscores the diagnostic and prognostic impact of angioinvasion in these tumors. Reticulin algorithm and Helsinki scoring system were added to assist the differential diagnosis of adrenal cortical neoplasms in adults. Pediatric adrenal cortical neoplasms are assessed using the Wieneke system. The 5th edition WHO classification places an emphasis on an accurate assessment of tumor proliferation rate using both the mitotic count (mitoses per 10 mm2) and Ki-67 labeling index which play an essential role in the dynamic risk stratification of affected patients. This review highlights advances in knowledge of histological features, ancillary studies, and associated genetic findings that increase the understanding of the adrenal cortex pathologies in the 5th edition WHO classification.


Subject(s)
Adrenal Cortex Neoplasms , Adrenal Gland Neoplasms , Adrenocortical Carcinoma , Adult , Humans , Child , Aldosterone , Adrenal Cortex Neoplasms/chemistry , Adrenocortical Carcinoma/chemistry , Adrenocortical Carcinoma/diagnosis , Adrenocortical Carcinoma/pathology , World Health Organization
4.
Zhonghua Gan Zang Bing Za Zhi ; 30(10): 1050-1055, 2022 Oct 20.
Article in Chinese | MEDLINE | ID: mdl-36727228

ABSTRACT

Objective: To compare and analyze the clinicopathological features and significance for indications of different types of antiviral therapy in chronic hepatitis B (CHB). Methods: Clinical data of 861 CHB cases who received liver biopsy, had hepatitis B virus (HBV) DNA-positive (> 30 IU/ml) and met the indications for antiviral therapy from January 2014 to December 2019 were included. Liver pathological changes and their correlation with clinical characteristics were compared and analyzed. According to different data, t-test, analysis of variance, nonparametric test, χ2 test, Ridit and logistic regression analysis were used for statistical analysis. Results: Most of the cases (72.24%) had remarkable pathological damage. The degree of liver fibrosis was higher in the normal than the abnormal group (P<0.001). 17.54% cases had hepatic steatosis. The vast majority of cases (97.33%) had positive hepatitis B surface antigen (HBsAg), while only 50.87% had positive hepatitis B core antigen (HBcAg). The positive correlation factors affecting the severity of liver histopathology were alkaline phosphatase level, while the negative correlation factors were positive HBcAg staining, albumin and platelet level. The degree of liver inflammation and fibrosis had statistically significant differences with different HBcAg staining levels (χ2=44.142 and 102.386, respectively; P<0.001), and the severity was more apparent in the negative group. Conclusion: There exist differences in clinicopathological features for indications of different types of antiviral therapy in patients with CHB. Liver function test range is inconsistent with degrees of hepatic histological severity. The positive and intensity of liver tissue HBcAg staining, and albumin and alanine aminotransferase levels have negative correlation with disease severity.


Subject(s)
Hepatitis B, Chronic , Humans , Hepatitis B Core Antigens , DNA, Viral , Hepatitis B virus/genetics , Liver/pathology , Hepatitis B Surface Antigens/analysis , Antiviral Agents/therapeutic use , Hepatitis B e Antigens
5.
Zhonghua Nei Ke Za Zhi ; 60(10): 891-897, 2021 Oct 01.
Article in Chinese | MEDLINE | ID: mdl-34551478

ABSTRACT

Objective: To analyze the liver pathology, clinical characteristics and influence factors in patients with chronic hepatitis B virus (HBV) infection in immune tolerant phase (IT). Methods: The clinical data of 273 patients in IT phase who underwent liver biopsy from January 2015 to December 2019 were included in this study. The correlation between liver pathological changes and clinical features was analyzed. Results: There were 43 cases (15.75%) with liver histologic activity ≥ G2, 30 cases (10.99%) with liver fibrosis ≥ S2, and 55 cases (20.15%) with liver pathology ≥ G2 and/or ≥ S2. A total of 17.95% patients had liver steatosis. The majority (98.17%) of tissue samples were positive for HBsAg staining, while only 79.49% were positive for HBcAg. The characteristics of liver pathology were comparable in men from women patients. The differences of G and S were not statistically significant according to different HBsAg positivity, while those were statistically significant according to different HBcAg positivity. By univariate and multivariate analysis, the independent risk factors of pathological severity were HBcAg intensity, HBeAg level, and age. However, the differences of liver histologic activity and fibrosis were not statistically significant between those younger than 30 years old group from those older than 30 years old, neither between those younger or older than 40. Although the diagnostic value of liver inflammation and fibrosis 5 (LIF-5) was better than that of aspartate aminotransferase-to-platelet ratio index (APRI) and fibrosis 4 score (FIB-4), three diagnostic models for predicting the pathological severity were not strong enough (all area under the curves<0.8). Only the specificity of LIF-5 for predicting≥ G2, ≥ G2 and/or ≥ S2 was over 80%. Conclusions: Approximately 20% patients with chronic HBV infection in IT phase have progressive liver inflammation or fibrosis. The intensity of liver HBcAg and HBeAg level are negatively correlated with the severity of disease. The diagnostic models or most clinical indicators have low predictive effect for chronic HBV infections in IT phase.


Subject(s)
Hepatitis B, Chronic , Adult , Female , Hepatitis B Surface Antigens , Hepatitis B e Antigens , Hepatitis B virus , Humans , Liver , Liver Cirrhosis , Male
6.
Zhonghua Liu Xing Bing Xue Za Zhi ; 42(2): 278-283, 2021 Feb 10.
Article in Chinese | MEDLINE | ID: mdl-33626616

ABSTRACT

Objective: To understand the current status of HIV self-testing reagent use in pre-exposure prophylaxis (PrEP) and related factors in men who have sex with men (MSM). Methods: From December 2018 to December 2019, "Gold data" online platform (www.jinshuju.com) was used to conduct multicenter PrEP studies in Shenyang, Beijing, Chongqing and Shenzhen of China. Results: A total of 1 222 MSM PrEP users were included in the multicenter study. The average age of the participants was (31.5±8.7) years, and the number of sexual partners in the past three months was 3 (P25,P75:2,6). The proportions of those who did not use condoms in anal sex with fixed, casual and commercial partners were 62.7% (456/727), 56.3% (440/781) and 41.0% (16/39), respectively. Up to 74.5% (910/1 222) of participants had used HIV self-testing reagents, and the number of HIV self-testing during last year was 3 (P25,P75:2,5). The multivariate logistic regression analysis indicated that compared with age group >40 years, those with education level of junior high school or below, those with psychological identity as female, event driven PrEP users, those never using new type drugs in past 3 months, the participants aged 18- years (aOR=2.06, 95%CI: 1.35-3.14), 26- years (aOR=2.72, 95%CI: 1.77-4.17), 31- years (aOR=1.76, 95%CI: 1.19-2.59), undergraduates (aOR=2.18, 95%CI: 1.35-3.49), graduate students and above (aOR=3.06, 95%CI: 1.69-5.54), those with psychological identity as male (aOR=3.22, 95%CI: 1.55-6.70), daily PrEP users (aOR=1.35, 95%CI: 1.03-1.78), and new type drug users in the past three months (aOR=1.72, 95%CI: 1.30-2.28) had higher proportions of HIV self-testing behaviors. Conclusions: The proportion of HIV self-testing in MSM PrEP users was high, while it was relatively low in older age group, event driven PrEP users and MSM never using new type drugs. To assess and improve the effectiveness and compliance of PrEPs, it is necessary to provide better HIV self-testing service for MSM with low HIV self-testing rate.


Subject(s)
HIV Infections , Homosexuality, Male , Pre-Exposure Prophylaxis , Self-Testing , Adolescent , Adult , China , HIV Infections/prevention & control , Homosexuality, Male/statistics & numerical data , Humans , Indicators and Reagents , Male , Socioeconomic Factors , Young Adult
7.
Zhonghua Yu Fang Yi Xue Za Zhi ; 54(12): 1396-1401, 2020 Dec 06.
Article in Chinese | MEDLINE | ID: mdl-33333657

ABSTRACT

Objective: To analyze the association between elevated blood pressure (BP) and carotid intima-media thickness (cIMT) in children according to four BP references. Methods: Study population came from"Huantai Childhood Cardiovascular Health Cohort Study"in Huantai County, Zibo City, Shandong Province. A convenient cluster sampling method was used to conduct a cross-sectional survey on 1 515 children from November 2017 to January 2018 in a primary school. A total of 1 431 children aged 6-11 years old with complete data were included in this study. Data on demographic characteristics, BP and cIMT were collected through questionnaire survey, physical examination and ultrasound examination. High cIMT was defined as the level of cIMT ≥ age-and sex-specific 90th percentile of this study population. Based on the Chinese Guideline reference, the Health Industry reference, the International reference and the U.S. reference, all participants were divided into three subgroups: the normal BP, high normal BP and, elevated BP. The multivariate logistic regression models were used to examine the association between BP status and high cIMT in children. Results: The age of children was (8.9±1.5) years, and boys accounted for 53.4% (n=682). The multivariate logistic regression models showed that after adjusting for relevant confounding factors, the risk of high cIMT in elevated BP group was increased compared with the normal BP group according to the four references (all P values<0.05) Conclusion: Elevated BP according to the four BP references is associated with high cIMT in children.


Subject(s)
Blood Pressure Determination , Carotid Intima-Media Thickness , Blood Pressure , Child , Cohort Studies , Cross-Sectional Studies , Humans , Male , Risk Factors
8.
Zhonghua Yi Xue Za Zhi ; 97(30): 2372-2378, 2017 Aug 08.
Article in Chinese | MEDLINE | ID: mdl-28822457

ABSTRACT

Objective: To evaluate the safety and efficacy of peripheral arterial disease patients with critical limb ischemia who accepted BSX or EVT. Methods: According to the requirements of systematic review, we searched MEDLINE (1980-2014), Emabse (1980-2014), Journals @ Ovid Full Text (1980-2014) databases, selected literature and extracted data, meta-analysis was performed through STATA11.2. Results: A total of 17 studies (3 RCTs, 14 non-randomized studies) and 5 515 patients (BSX group: 2 454, EVT group: 2 769) were deemed eligible. Meta-analysis showed there were no differences between the two groups in 30-day mortality (OR=1.110, P=0.523). However, BSX was significantly associated with increasing overall complications (OR=2.456, P=0.003), infections (OR=3.163, P<0.001) and thrombosis (OR=3.069, P=0.002), but showed a reduction in dissection and pseudoaneurysm (OR=0.537, P=0.012). During the follow-up, BSX had significant advantages. The 1-year and 3-year primary patency of BSX patients were higher than EVT group (1 year, OR=1.415, P=0.008; 3 years, OR=1.619, P<0.001); so were in secondary patency( 1 year, OR=2.156, P<0.001; 3 years, OR=2.547, P<0.001). Meanwhile, the 5-year overall survival rate was also higher in BSX group (OR=1.243, P=0.007). Conclusions: EVT has potential advantages in reducing surgical trauma and early postoperative complications, shortening hospital stay and so on. Concerning long-term results, BSX is better in reducing long-term mortality and improving long-term patencies than EVT group.


Subject(s)
Ischemia , Peripheral Arterial Disease , Amputation, Surgical , Angioplasty, Balloon , Humans , Retrospective Studies , Risk Factors , Treatment Outcome
9.
Zhonghua Wai Ke Za Zhi ; 54(12): 891-893, 2016 Dec 01.
Article in Chinese | MEDLINE | ID: mdl-27916029

ABSTRACT

Bypass surgery(BSX) and endovascular therapy(EVT) are the most important therapeutic method to critical limb ischemia.EVT has potential advantages in reducing surgical trauma and early postoperative complications, shortening hospital stay and so on. Concerning long-term results, BSX is better in reducing long-term mortality and improving long-term patency than EVT group. Therefore, control indications reasonably and select individualized methods, avoid the abuse of EVT are more meaningful for patients.


Subject(s)
Peripheral Arterial Disease/surgery , Vascular Grafting , Aged , Endovascular Procedures , Female , Humans , Ischemia , Limb Salvage , Male , Middle Aged , Postoperative Complications , Retrospective Studies , Treatment Outcome
10.
J Biol Regul Homeost Agents ; 29(2): 367-72, 2015.
Article in English | MEDLINE | ID: mdl-26122224

ABSTRACT

An increasing number of people die from breast cancer every year. Consequently, more research has been concentrated on the study of this type of tumour, and miR-373 resulted as an important gene for treating breast cancer. To explore the influence of miR-373 on the invasion and migration of breast cancer and the expression level of target gene TXNIP, a set of therapeutic methods were designed based on miR-373. The transfection was performed using miR-373 inhibitor; the concentration of miR-373 was controlled by inhibitor, and it was transfected into MCF-7 cell by lipofectin. Fluorescent quantitative polymerase chain reaction was used to detect the expression level of miR-373 in cells after transfection as well as that of Caspase-3 and Caspase-8. MTT assay was used to detect the influence of miR-373 inhibitor on MCF-7 cells. The expression quantity of miR-373 in cell and tissue of breast cancer with high-low invasion and migration ability was detected by qRT-PCR (quantitative real-time polymerase chain reaction), thus the influence of the expression quantity of miR-373 on the invasion and migration of cell was determined. The expression of miR-373, EMT and TXNIP was determined by Western blot. Through the identification of proteomics and bioinformatics, it was finally found that TXNIP was regulated by miR-373. The protein expression level of TXNIP was negatively correlated with the level of miR-373. Thus it was concluded that miR-373 could promote the invasion and migration of breast cancer. In addition, in the tissue and cell of breast cancer with different invasion and migration abilities, the expression level of TXNIP was negatively correlated with the level of miR-373.


Subject(s)
Breast Neoplasms/pathology , Carrier Proteins/physiology , Gene Expression Regulation, Neoplastic , MicroRNAs/physiology , Neoplasm Proteins/physiology , RNA, Neoplasm/physiology , Adenocarcinoma/pathology , Breast Neoplasms/genetics , Breast Neoplasms/metabolism , Carrier Proteins/biosynthesis , Carrier Proteins/genetics , Caspase 3/biosynthesis , Caspase 3/genetics , Caspase 9/biosynthesis , Caspase 9/genetics , Cell Line, Tumor , Female , Humans , MicroRNAs/antagonists & inhibitors , Neoplasm Proteins/biosynthesis , Neoplasm Proteins/genetics , RNA, Messenger/biosynthesis , RNA, Neoplasm/antagonists & inhibitors , RNA, Neoplasm/biosynthesis , Transfection , Up-Regulation
11.
Clin Pharmacol Ther ; 94(1): 80-94, 2013 Jul.
Article in English | MEDLINE | ID: mdl-23588303

ABSTRACT

Drug interactions due to efflux transport inhibition at the blood-brain barrier (BBB) have been receiving increasing scrutiny because of the theoretical possibility of adverse central nervous system (CNS) effects identified in preclinical studies. In this review, evidence from pharmacokinetic, pharmacodynamic, imaging, pharmacogenetic, and pharmacovigilance studies, along with drug safety reports, is presented supporting a low probability of modulating transporters at the human BBB by currently marketed drugs.


Subject(s)
Blood-Brain Barrier/metabolism , Drug Interactions , Membrane Transport Proteins/metabolism , Pharmaceutical Preparations , Biological Transport/physiology , Drug Design , Drug Evaluation, Preclinical , Humans , Pharmacokinetics
12.
Drug Deliv ; 17(1): 28-37, 2010 Jan.
Article in English | MEDLINE | ID: mdl-22747073

ABSTRACT

The study described the development of lipid vesicles as colloidal carriers for uricase, an enzyme with low activity at physicological conditions and low stability in vitro and in vivo. The lipid vesicles containing uricase (UOXLVs) were prepared and the process parameters were optimized with the indexes of entrapment efficiency, polydispersion, particle size, and zeta potential. The storage stability of uricase in lipid vesicles was significantly increased compared to that of free uricase at 4°C. The stability to proteolytic digestion was also increased obviously by entrapping the uricase in the lipid vesicles. In vitro and in vivo pharmacodynamic studies on the hyperuricemia rat model explicitly suggested that the uricase entrapped by UOXLVs possessed high uricolytic activity and distinctively decreased the uric acid level.


Subject(s)
Drug Carriers/chemistry , Phosphatidylcholines/chemistry , Urate Oxidase/administration & dosage , Animals , Drug Compounding , Drug Storage , Enzyme Stability , Male , Particle Size , Rats , Rats, Sprague-Dawley , Surface Properties , Urate Oxidase/chemistry , Urate Oxidase/pharmacokinetics
13.
Int J Pharm ; 384(1-2): 165-72, 2010 Jan 15.
Article in English | MEDLINE | ID: mdl-19782743

ABSTRACT

Uricase-containing lipid vesicles (UOXLVs) were prepared by reverse-phase evaporation method with high efficiency and the characteristics of UOXLVs were described. The average size and zeta potential of UOXLVs obtained by the optimized formulation were 205.47 nm and -37.33 mV, respectively. Uricase was encapsulated in the alkaline aqueous phase of the lipid vesicle and the stability of its tetrameric structure was thus improved and its activity preserved. The storage stability of uricase in lipid vesicles was significantly increased compared to that of free uricase at 4 degrees C in borate buffer of pH 8.5. At 55 degrees C, free uricase was deactivated much more quickly especially at lower concentration predominantly due to enhanced dissociation of uricase into subunits. An intrinsic tryptophan of uricase recovered from the lipid vesicle thermally treated at 55 degrees C revealed that a partially denatured uricase molecule was stabilized through its hydrophobic interaction with lipid vesicle membrane. This interaction was depressed mainly by dissociation of uricase into subunits. At the physiological pH, significant increase of enzyme activity was found for the uricase entrapped in the lipid vesicles (1.8 times that of free uricase) at their respective optimum pH. The shift of optimum pH and increased uricolytic activity suggested the conformation change of the uricase during the entrapment process. The stability to proteolytic digestion was increased obviously by entrapping the uricase in the lipid vesicles. UOXLVs also showed relatively slower loss in activity compared with free uricase when treated with some chemical reagents. Lastly, in vitro study explicitly indicated that the uricase entrapped by UOXLVs possessed higher uricolytic activity than that of native uricase solution.


Subject(s)
Lipids/chemistry , Urate Oxidase/chemistry , Urate Oxidase/metabolism , Animals , Cattle , Drug Carriers/administration & dosage , Drug Carriers/chemistry , Drug Carriers/metabolism , Drug Stability , Enzyme Activation/physiology , Lipids/administration & dosage , Urate Oxidase/administration & dosage
14.
Anal Chem ; 78(22): 7891-5, 2006 Nov 15.
Article in English | MEDLINE | ID: mdl-17105185

ABSTRACT

Different pharmaceutical preparations against the common cold contain acetaminophen, phenylephrine hydrochloride, and chlorpheniramine maleate. A degradation product had been discovered in these preparations after short- and long-term stability studies. This degradation product was isolated and found to be an adduct of phenylephrine and maleic acid. An account of the isolation and characterization of this compound was published. Our interest in this area led us to synthesize the compound, and we found that the synthesized compound does not have the same spectroscopic properties described in the original paper. Our subsequent work identified the structure of the degradation product as a "Michael addition" product of phenylephrine and maleic acid.


Subject(s)
Acetaminophen/analysis , Chemistry, Pharmaceutical , Chlorpheniramine/isolation & purification , Phenylephrine/isolation & purification , Acetaminophen/chemistry , Analgesics, Non-Narcotic/analysis , Analgesics, Non-Narcotic/pharmacology , Anti-Allergic Agents/analysis , Anti-Allergic Agents/pharmacology , Chlorpheniramine/chemistry , Common Cold/drug therapy , Drug Stability , Magnetic Resonance Spectroscopy , Maleates/isolation & purification , Nasal Decongestants/analysis , Nasal Decongestants/pharmacology , Phenylephrine/chemistry
15.
J Am Soc Mass Spectrom ; 12(10): 1127-35, 2001 Oct.
Article in English | MEDLINE | ID: mdl-11605975

ABSTRACT

A fast method to detect and sequence photomodified oligodeoxynucleotides (ODNs) by exonuclease digestion and matrix-assisted laser desorption/ionization (MALDI) mass spectrometry (MS) is reported. Upon treatment of modified ODNs with both phosphodiesterase I and phosphodiesterase II, the digestion stops at the sites of photomodification. Post-source decay (PSD) of MALDI-produced ions from two enzymatic digestion end products distinguishes isomers such as 5'-d(T[cis-syn]TAAGC) and 5'-d(CGAAT[cis-syn]T), which have symmetrical or identical compositions at the 3' and 5' ends, respectively. Studies have also been done to follow the kinetics for enzyme degradation of photomodified ODNs. The calculated rate constants from a mathematical treatment of the time-dependent MALDI data clearly show that the enzymatic digestion rate slows as the enzyme approaches the modified site.


Subject(s)
Exonucleases/chemistry , Oligonucleotides/chemistry , Hydrolysis , Kinetics , Photochemistry , Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
16.
Anal Chem ; 73(15): 3679-86, 2001 Aug 01.
Article in English | MEDLINE | ID: mdl-11510834

ABSTRACT

Room-temperature ionic liquids are useful as solvents for organic synthesis, electrochemical studies, and separations. We wished to examine whether their high solubalizing power, negligible vapor pressure, and broad liquid temperature range are advantageous if they are used as matrixes for UV-MALDI. Several different ionic matrixes were synthesized and tested, using peptides, proteins, and poly(ethylene glycol) (PEG-2000). All ionic liquids tested have excellent solubilizing properties and vacuum stability compared to other commonly used liquid and solid matrixes. However, they varied widely in their ability to produce analyte gas-phase ions. Certain ionic matrixes, however, produce homogeneous solutions of greater vacuum stability, higher ion peak intensity, and equivalent or lower detection limits than currently used solid matrixes. Clearly, ionic liquids and their more amorphous solid analogues merit further investigation as MALDI matrixes.


Subject(s)
Bradykinin/analysis , Coumaric Acids/chemistry , Insulin/analysis , Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization , Animals , Apoproteins/analysis , Humans , Myoglobin/analysis , Polyethylene Glycols/analysis , Solvents
17.
Anal Chem ; 73(14): 3263-73, 2001 Jul 15.
Article in English | MEDLINE | ID: mdl-11476224

ABSTRACT

A method using a combination of exonuclease enzymatic digestion and matrix-assisted laser desorption/ionization (MALDI) mass spectrometry was developed to locate model abasic sites in a series of model 21-base oligodeoxynucleotides in which a nucleobase was replaced by a hydrogen atom. The exonuclease digestion rate, with either snake venom phosphodiesterase (SVP) or bovine spleen phosphodiesterase (BSP), clearly slows as the digestion approaches the abasic sites and stops as it reaches it. An oligodeoxynucleotide containing an abasic site in which OH replaces the nucleobase shows similar results. MALDI mass spectra taken at appropriate times during the course of hydrolysis are the basis for rate measurements, and the kinetics also reveal the location of the abasic site. A mathematical treatment of the time-dependent MALDI data was implemented to obtain rate curves and rate constants for the enzymatic digestion of both modified and unmodified oligodeoxynucleotides.


Subject(s)
Apurinic Acid/metabolism , Exonucleases/metabolism , Oligonucleotides/metabolism , Phosphoric Diester Hydrolases/metabolism , Polynucleotides/metabolism , Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization/methods , Apurinic Acid/chemistry , Base Sequence , Chromatography, High Pressure Liquid , DNA/chemistry , DNA/metabolism , Exonucleases/chemistry , Hydrolysis , Kinetics , Oligonucleotides/chemistry , Phosphodiesterase I , Phosphoric Diester Hydrolases/chemistry , Polynucleotides/chemistry
18.
J Am Soc Mass Spectrom ; 12(4): 376-80, 2001 Apr.
Article in English | MEDLINE | ID: mdl-11322184

ABSTRACT

The product ion formation characteristics of the four diastereomeric tetrahydroxy benzo[ghi]fluoranthene compounds formed by hydrolysis of the syn and anti diastereomers of trans-3,4-dihydroxy-5,5a-epoxy-3,4,5,5a-tetrahydrobenzo[ghi]fluoranthene are studied using matrix-assisted laser desorption/ionization and post-source decay (PSD) to determine a correlation between the fragmentation characteristics of these tetraols and the structures of the diol-epoxide diastereomers from which they are hydrolyzed. The tetraols formed by the trans ring opening of the diol epoxides during hydrolysis yield product ion spectra specific for the syn and anti configurations of their precursor diol epoxides. All four diastereomeric tetraols form product ions by the losses of one and/or two water molecules in varying proportions when lithium-cationized molecule ions (m/z 301) are selected for PSD product ion analysis. The differences in the PSD spectra of these four Li+-cationized molecules are rationalized in terms of a water loss mechanism that involves the 1,2 elimination of a hydrogen atom and hydroxyl group that are cis with respect to each other on adjacent carbons.


Subject(s)
Fluorenes/chemistry , Molecular Conformation , Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization , Stereoisomerism
19.
J Am Soc Mass Spectrom ; 11(10): 854-65, 2000 Oct.
Article in English | MEDLINE | ID: mdl-11014447

ABSTRACT

A comatrix of anthranilic acid and nicotinic acid is optimum for the matrix-assisted laser desorption/ionization time of flight determination of oligodeoxynucleotides that are comprised of up to 21 nucleotides. A detection limit of approximately 200 amol was obtained for an oligonucleotide 21mer. The comatrix system is also suitable for quantification of oligodeoxynucleotides provided an internal standard having one more or less nucleotide than the number in the analyte is used. Furthermore, the matrix, when used in combination with the ladder method of sequencing, allows the complete sequence of tens of picomoles of model oligodeoxynucleotides to be determined.


Subject(s)
Oligonucleotides/analysis , Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization/methods , Base Sequence , Calibration , Escherichia coli/chemistry , Hydrolysis , Indicators and Reagents , Phosphoric Diester Hydrolases , Sequence Analysis , Sequence Analysis, RNA , ortho-Aminobenzoates
20.
Sheng Li Xue Bao ; 52(6): 459-62, 2000 Dec.
Article in Chinese | MEDLINE | ID: mdl-11941407

ABSTRACT

The present study was undertaken to explore the mechanism of G protein-mediated signal transduction pathway during endothelin-1 (ET-1) pre-treatment and ischemic preconditioning (IP). Rats were divided into four groups: ET-1, IP, ischaemia-reperfusion (IR) and control groups. ET-1 pre-treatment model was prepared by administrating 0.5 nmol/(L.kg) ET-1 into rat left ventricle, whereas IP model was prepared by ligating the left coronary artery for 5 min followed by 30 min reperfusion. All the animals were subjected to 60 min regional ischaemia and 30 min reperfusion alternately and then parameters of ventricular arrhythmia and expression of cardiac Galphaq/11 and Gialpha2 were measured. The results showed that the scores of ventricular arrhythmia decreased significantly in both ET-1 and IP treated groups as compared with IR group. In comparison with control group, Galphaq/11 increased by 77.8% (P<0.05) and 110.6% (P<0.01) in IP and ET-1 group respectively. Gialpha2 showed no significant difference in IP group, while it decreased by 31.0% (P<0.01) in ET-1 group. In conclusion, activation of G alphaq/11 may be related to the protecting mechanism of ET-1 pre-treatment and IP, whereas Gialpha2 may only play a role in ET-1 pre-treatment.


Subject(s)
Endothelin-1/pharmacology , GTP-Binding Protein alpha Subunits, Gi-Go/metabolism , Heterotrimeric GTP-Binding Proteins/metabolism , Ischemic Preconditioning, Myocardial , Myocardium/metabolism , Proto-Oncogene Proteins/metabolism , Animals , GTP-Binding Protein alpha Subunit, Gi2 , GTP-Binding Protein alpha Subunits, Gq-G11 , Male , Rats , Rats, Wistar
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