Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 27
Filter
1.
Zhonghua Yan Ke Za Zhi ; 59(10): 838-845, 2023 Oct 11.
Article in Chinese | MEDLINE | ID: mdl-37648680

ABSTRACT

Objective: To investigate the clinical presentation pattern of acute primary angle-closure glaucoma (PACG) during the 2019 novel coronavirus (2019-nCoV) pandemic over the past three years, and its relationship with 2019-nCoV infections of Omicron variants in Guangdong province. Methods: Ecological study.Patients who were newly diagnosed with acute PACG from February 2020 to January 2023 at the Zhongshan Ophthalmic Center of Sun Yat-sen University were included in the study, and their basic information was collected. Patients were divided into the 2020 group (diagnosed between February 1st, 2020 and January 31st 2021), the 2021 group (diagnosed between February 1st, 2021 and January 31st 2022), and the 2022 group (diagnosed between February 1st, 2022 and January 31st 2023). The clinical presentation pattern of newly diagnosed acute PACG was observed and compared between groups. The daily number of newly diagnosed 2019-nCoV infections in Guangdong province was obtained from the Chinese Center for Disease Control and Prevention. The correlation between the daily number of newly diagnosed acute PACG and that of newly diagnosed 2019-nCoV infections during the epidemic period of Omicron variants between December 2022 and January 2023 was assessed. Results: The study included 1 048 patients with newly diagnosed acute PACG, with 235 for the 2020 group, 274 for the 2021 group, and 539 for the 2022 group. Our results showed that the average weekly number of newly diagnosed acute PACG patients in 2022 [8 (5, 11)] was significantly larger than that in 2020 (4.52±1.95, P<0.05) and 2021 (5.27±2.76, P<0.05). The average weekly number increased to 22.11±20.84 between December 2022 and January 2023. The total number of newly diagnosed acute PACG patients during this period was 199, which was 36.9% (199/539) of the total number of the same year and was 6.63 and 6.42 times as many as that in the same period (December and January) of 2020 and 2021. The proportion of patients with bilateral eye involvement during this period in 2022 was significantly higher than that in 2020 and 2021 (P<0.05). Further analysis found that 88.6% (109/123) of cases had a history of 2019-nCoV infection 2 (0, 3) days before the onset of acute PACG symptoms in average. The estimated daily number of acute PACG onset increased rapidly, peaked on December 23th, 2022, and then dropped gradually. This trend was similar to that of the daily number of new 2019-nCoV infections in Guangdong province. Changes of the daily number of new 2019-nCoV infections in Guangdong province had a positive correlation with the estimated daily number of acute PACG onset (r=0.84, P<0.001). Conclusion: A dramatic increase in the clinical presentation of acute PACG was observed at Zhongshan Ophthalmic Center between December 2022 and January 2023, which was the epidemic period of Omicron variants. There is a correlation between the trend of the estimated daily number of acute PACG onset and that of new 2019-nCoV infections of Omicron variants in Guangdong province, but the exact reason remains to be further studied. (This article was published ahead of print on the official website of Chinese Journal of Ophthalmology on August 31, 2023).

2.
Zhonghua Kou Qiang Yi Xue Za Zhi ; 57(6): 629-634, 2022 Jun 09.
Article in Chinese | MEDLINE | ID: mdl-35692008

ABSTRACT

Prediabetes mellitus (Pre-DM) is an intermediate state of hyperglycemia between normal blood glucose homeostasis and type 2 diabetes mellitus (T2DM). More than half of adults in China suffer from Pre-DM. Periodontitis is a chronic inflammatory disease mainly caused by microorganisms in dental plaque. It shares common risk factors and interacts with non-communicable diseases such as diabetes mellitus. Pre-DM may increase the risk of periodontitis, and the latter may also influence the development and progress of diabetes. Oxidative stress, systemic inflammation and intestinal flora are the main mechanisms by which Pre-DM and periodontitis interconnect with each other. This article mainly reviews the relationship between Pre-DM and periodontitis and potential related mechanisms, providing a new basis for the prevention and treatment of both.


Subject(s)
Chronic Periodontitis , Diabetes Mellitus, Type 2 , Periodontitis , Prediabetic State , Adult , Diabetes Mellitus, Type 2/complications , Humans , Inflammation , Periodontitis/complications , Risk Factors
3.
Sci Rep ; 11(1): 12903, 2021 06 18.
Article in English | MEDLINE | ID: mdl-34145342

ABSTRACT

Abdominal aortic aneurysm (AAA) is a complex disease which is incompletely accounted for. Basement membrane (BM) Collagen IV (COL4A1/A2) is abundant in the artery wall, and several lines of evidence indicate a protective role of baseline COL4A1/A2 in AAA development. Using Col4a1/a2 hemizygous knockout mice (Col4a1/a2+/-, 129Svj background) we show that partial Col4a1/a2 deficiency augmented AAA formation. Although unchallenged aortas were morphometrically and biomechanically unaffected by genotype, explorative proteomic analyses of aortas revealed a clear reduction in BM components and contractile vascular smooth muscle cell (VSMC) proteins, suggesting a central effect of the BM in maintaining VSMCs in the contractile phenotype. These findings were translated to human arteries by showing that COL4A1/A2 correlated to BM proteins and VSMC markers in non-lesioned internal mammary arteries obtained from coronary artery bypass procedures. Moreover, in human AAA tissue, MYH11 (VSMC marker) was depleted in areas of reduced COL4 as assessed by immunohistochemistry. Finally, circulating COL4A1 degradation fragments correlated with AAA progression in the largest Danish AAA cohort, suggesting COL4A1/A2 proteolysis to be an important feature of AAA formation. In sum, we identify COL4A1/A2 as a critical regulator of VSMC phenotype and a protective factor in AAA formation.


Subject(s)
Aortic Aneurysm, Abdominal/etiology , Basement Membrane/metabolism , Collagen Type IV/deficiency , Genetic Predisposition to Disease , Alleles , Animals , Aortic Aneurysm, Abdominal/metabolism , Aortic Aneurysm, Abdominal/pathology , Biomarkers , Biopsy , Collagen Type IV/genetics , Disease Models, Animal , Enzyme-Linked Immunosorbent Assay , Genetic Association Studies , Genotype , Immunohistochemistry , Male , Mice , Mice, Knockout , Muscle, Smooth, Vascular/metabolism , Myocytes, Smooth Muscle/metabolism , Proteolysis , Proteome , Proteomics/methods
4.
Zhonghua Yan Ke Za Zhi ; 56(1): 13-16, 2020 Jan 11.
Article in Chinese | MEDLINE | ID: mdl-31937058

ABSTRACT

Glaucoma surgery is one of the main methods of glaucoma treatment. In recent years, glaucoma surgery has been greatly developed. Minimally invasive surgical procedures for glaucoma have emerged. Patients and surgeons have also increased their expectations of surgery. However, due to the limitation of surgical controllability, the prediction of postoperative efficacy is still not satisfactory. By analyzing the principles and limitations of the existing surgical procedures, the authors put forward the premise of the controllability of glaucoma extrafiltration surgery as that the intraoperative filtration excess can be restricted, so as to effectively avoid the early postoperative complications such as shallow anterior chamber, hypotony and strong inflammation. And within 1 month after surgery, through the filtration of the bubble and the removal of the adjustable suture, the ideal filtration state is gradually achieved. With the controllable maintenance of intraocular pressure at 1 month after surgery, it is possible to effectively predict the intraocular pressure level of 2 years or longer. (Chin J Ophthalmol, 2020, 56: 13-16).


Subject(s)
Filtering Surgery/methods , Glaucoma/surgery , Intraocular Pressure , Glaucoma/diagnosis , Humans , Lens Implantation, Intraocular , Phacoemulsification , Postoperative Complications , Sutures , Tonometry, Ocular , Treatment Outcome
5.
Zhonghua Lao Dong Wei Sheng Zhi Ye Bing Za Zhi ; 37(10): 768-772, 2019 Oct 20.
Article in Chinese | MEDLINE | ID: mdl-31726509

ABSTRACT

Objective: To investigate the visual application of the CiteSpace software in the field of work-related musculoskeletal disorders (WMSDs) . Methods: The literature on WMSDs research, published from 1991 to 2017, was retrieved in Web of Science database. The CiteSpace 5.2 was used to make visualization analysis on the hotspots and tendency of the keywords, authors, countries (regions) and research institutes in relevant literature. Results: A total of 3224 literatures were included in the analysis. The amount of the literatures published was increasing annually. The key word co-occurrence network showed that the research hotspots mainly focused on the study of epidemiology, risk factors, symptoms, and other aspects of WMSDs. The cooperation network and time network of counties and regions showed that America and Europe were at the leading position in the field of WMSD, and the top three were America, Canada and Sweden. The developing countries, like Brazil and China, had also begun to make relative research since 2000. In research cooperation, the collaboration among countries, research institutions was relatively close, and multiple leading core authors and teams were formed in the international arena. Conclusion: The CiteSpace software can directly demonstrate the hotspots and tendency in the area of WMSDs.


Subject(s)
Diagnosis, Computer-Assisted , Musculoskeletal Diseases/diagnosis , Occupational Diseases/diagnosis , Software , Humans
6.
Death Stud ; 43(6): 372-380, 2019.
Article in English | MEDLINE | ID: mdl-30015574

ABSTRACT

This study aims to examine perceived challenges, including knowledge, skills, self, and work environment, of professionals in providing pediatric palliative care (PPC) in Hong Kong and the differences in perceived challenges between groups. A total of 680 pediatric doctors and nurses participated in the survey. They tended to perceive the provision of PPC as difficult and considered "advanced skills" (those dealing with death-related issues) challenging. Findings indicate that nurses, professionals who are less experienced, do not have children, and have not received palliative care training perceived a higher level of challenges in providing PPC. Implications for training and support are discussed.


Subject(s)
Attitude of Health Personnel , Attitude to Death , Nurses/psychology , Palliative Care/psychology , Pediatricians/psychology , Adult , Female , Hong Kong , Humans , Male , Middle Aged , Pediatrics , Surveys and Questionnaires , Young Adult
7.
Skin Pharmacol Physiol ; 25(3): 124-32, 2012.
Article in English | MEDLINE | ID: mdl-22343606

ABSTRACT

The objective of this study was to investigate the effect of sebum on drug transport across the human stratum corneum (SC) in vivo for two model compounds, 4-cyanophenol (CP) and cimetidine (CM), of different lipophilicity and molecular size by utilizing noninvasive tape-stripping techniques, in conjunction with an unsteady-state diffusion model for data analysis. The results demonstrated that the SC permeability of the relatively hydrophilic CM on the forehead may be as much as four times the permeability on the forearm. The administration of sebum supplementation to the forearm increased the SC permeability of CM more than threefold, but did not have the same effect with regard to CP. Removal of sebum from the forehead demonstrated a small but significant effect (-22%) on the SC permeability of CM. The presence of sebum on the forehead or forearm increased the diffusion of both molecules, but the effect on partition varied between sites and drugs. The change in the SC permeability of the relatively hydrophilic drug using sebum treatment may be attributable to the altered barrier function of the SC due to the disordering structures of the intercellular lipid molecules.


Subject(s)
Cimetidine/metabolism , Phenols/metabolism , Sebum/metabolism , Skin Absorption , Skin/metabolism , Administration, Cutaneous , Adult , Biological Transport , Cimetidine/administration & dosage , Cimetidine/chemistry , Diffusion , Forearm , Forehead , Humans , Hydrophobic and Hydrophilic Interactions , Male , Models, Biological , Molecular Weight , Permeability , Phenols/administration & dosage , Phenols/chemistry , Sebum/chemistry , Skin/anatomy & histology , Spectroscopy, Fourier Transform Infrared , Taiwan , Time Factors , Water Loss, Insensible , Young Adult
8.
Transbound Emerg Dis ; 58(3): 232-9, 2011 Jun.
Article in English | MEDLINE | ID: mdl-21276209

ABSTRACT

The aim of this study was to evaluate the production of chicken anaemia virus VP3 protein in different Escherichia coli strains and to address the diagnostic application of purified E. coli-expressed VP3 protein for the detection of chicken anaemia virus (CAV) infection and the development of an ELISA kit. Three E. coli strains, BL21, BL21 codonplus RP and BL21 pLysS, each harbouring a VP3 protein expressing plasmid, were investigated after induction to produce recombinant VP3 protein. After isopropyl-ß-D-thiogalactoside (IPTG) induction, VP3 protein was successfully expressed in all three E. coli strains. The BL21 pLysS strain gave the best performance in terms of protein productivity and growth profile. In addition, the optimal culture temperature and IPTG concentration were found to be 0.25 mM and 20 °C, respectively. Using Ni-NTA-purified VP3 protein as an ELISA coating antigen, the purified VP3 was shown to be highly antigenic and able to discriminate sera from chickens infected with CAV from those that were uninfected during an evaluation of CAV infection serodiagnosis. A VP3-based ELISA demonstrated 100% (6/6 x 100%) specificity and sensitivities of 91.3% (21/23 x 100%) and 82.6% (19/23 x 100%) using cut-off values of the mean plus 2 SD and the mean plus 3 SD, respectively.


Subject(s)
Capsid Proteins/immunology , Chicken anemia virus/immunology , Escherichia coli/virology , Animals , Antigens, Viral , Chicken anemia virus/isolation & purification , Chickens/virology , Polymerase Chain Reaction , Sensitivity and Specificity , Temperature
9.
Proc Natl Acad Sci U S A ; 106(9): 3633-8, 2009 Mar 03.
Article in English | MEDLINE | ID: mdl-19211801

ABSTRACT

It is widely appreciated that neurotransmission systems interact in their effects on human cognition, but those interactions have been little studied. We used genetics to investigate pharmacological evidence of synergisms in nicotinic/muscarinic interactions on cognition. We hypothesized that joint influences of nicotinic and muscarinic systems would be reflected in cognitive effects of normal variation in known SNPs in nicotinic (CHRNA4 rs1044396) and muscarinic (CHRM2 rs8191992) receptor genes. Exp. 1 used a task of cued visual search. The slope of the cue size/reaction time function showed a trend level effect of the muscarinic CHRM2 SNP, no effect of the nicotinic CHRNA4 SNP, but a significant interaction between the 2 SNPs. Slopes were steepest in individuals who were both CHRNA4 C/C and CHRM2 T/T homozygotes. To determine the specificity of this synergism, Exp. 2 assessed working memory for 1-3 locations over 3 s and found no significant effects on either SNP. Interpreting these results in light of Sarter's [Briand LA, et al. (2007) Modulators in concert for cognition: Modulator interactions in the prefrontal cortex. Prog Neurobiol 83:69-91] claims of tonic and phasic modes of cholinergic activity, we argue that reorienting attention to the target after invalid cues requires a phasic response, dependent on the nicotinic system, whereas orienting attention to valid cues requires a tonic response, dependent on the muscarinic system. Consistent with that, shifting and scaling after valid cues (tonic) were strongest in CHRNA4 C/C homozygotes who were also CHRM2 T/T homozygotes. This shows synergistic effects within the human cholinergic system.


Subject(s)
Attention/physiology , Polymorphism, Single Nucleotide/genetics , Receptors, Muscarinic/metabolism , Receptors, Nicotinic/metabolism , Visual Perception/physiology , Adolescent , Adult , Aged , Aged, 80 and over , Genotype , Humans , Memory , Middle Aged , Receptors, Muscarinic/genetics , Receptors, Nicotinic/genetics
11.
Vaccine ; 20(3-4): 526-31, 2001 Nov 12.
Article in English | MEDLINE | ID: mdl-11672918

ABSTRACT

Economic models were used to describe the potential for an AIDS vaccine to prevent medical spending and lost productivity throughout the world. In terms of avoided medical spending, preventing 75% of the AIDS risk for 10 years in one adult male is estimated to be worth US$ 343 in western Europe, US$ 4.59 in south and SE Asia, and US$ 2.67 in sub-Saharan Africa. The expected medical savings from a 75% effective vaccine would exceed US$ 25.00 per person for over 700 million people. Although an AIDS vaccine would save more lives in poverty stricken areas, it would save more money in developed countries. The mismatch between the public health needs and market forces is highlighted by this model.


Subject(s)
AIDS Vaccines/economics , Acquired Immunodeficiency Syndrome/prevention & control , Models, Economic , Adolescent , Adult , Child , Child, Preschool , Humans , Infant , Infant, Newborn , Male , Middle Aged , Public Health
12.
J Am Geriatr Soc ; 48(11): 1389-97, 2000 Nov.
Article in English | MEDLINE | ID: mdl-11083313

ABSTRACT

OBJECTIVE: Older persons with general medical and surgical conditions increasingly receive posthospital rehabilitation care in nursing homes and rehabilitation hospitals. This study describes the characteristics of such patients, contrasted with patients with traditional rehabilitation diagnoses of hip fracture and stroke. DESIGN: Prospective cohort study. SETTING: Seventeen skilled nursing facilities and six rehabilitation hospitals in seven states. PARTICIPANTS: Medicare patients age 65 or older receiving posthospital rehabilitation. METHODS: A total of 290 medical/surgical patients were compared with 336 hip fracture and 429 stroke patients. Data were collected prospectively from charts, nursing assessments, and patient interviews. Patient characteristics associated with functional recovery and mortality were estimated using multivariate regression. RESULTS: Medical/surgical patients had greater premorbid activities of daily living (ADL) (P < .001) and instrumental activities of daily living (IADL) (P < .01) disability, but suffered less decline with the acute event than hip fracture or stroke patients (P < .001). Medical/surgical patients were more likely to recover premorbid ADL function (P < .05) but 1-year mortality was significantly greater (30% vs. 14% hip fracture; 18% stroke; P < .001). Predictors of functional recovery and mortality differed between the three groups. Among medical/surgical patients, premorbid ADL difficulty, cognitive impairment, a pressure ulcer at rehabilitation admission, and depression were associated with failure to recover premorbid function whereas increasing comorbidity and incontinence were associated with mortality. CONCLUSIONS: Medical/surgical patients represent a unique rehabilitation population. They experienced greater premorbid functional disability, less acute decline, but greater mortality than patients with traditional rehabilitation diagnoses. Further study of this distinct rehabilitation population may help identify patients most likely to benefit from rehabilitation.


Subject(s)
Activities of Daily Living , Hip Fractures/rehabilitation , Mortality , Postoperative Complications/rehabilitation , Rehabilitation Centers/statistics & numerical data , Rehabilitation , Skilled Nursing Facilities/statistics & numerical data , Stroke Rehabilitation , Aged , Aged, 80 and over , Female , Geriatric Assessment , Hip Fractures/mortality , Humans , Linear Models , Male , Medicare , Postoperative Complications/mortality , Predictive Value of Tests , Prospective Studies , Social Support , Stroke/mortality , Treatment Outcome , United States
13.
Inflammation ; 22(2): 161-73, 1998 Apr.
Article in English | MEDLINE | ID: mdl-9561926

ABSTRACT

Adjuvant arthritis (AA) is an accepted model of inflammatory arthritis. Until now, however, there is little information about inflammatory mediators, specifically in relation to the arachidonic acid cascade in AA. Our objective was to study the expression of secretory (sPLA2) and cytosolic (cPLA2) phospholipases A2 in various organs during the course of AA. AA was induced in Lewis rats which were sacrificed at days 0, 7, 14, 21, 28 and 42. Expression of sPLA2 mRNA and protein and mRNA of cPLA2 in paws, regional lymph nodes, spleen, liver, lungs and aorta was investigated. Serum sPLA2 activity increased from 15213 +/- 1131 to a maximum of 32,455 +/- 4109 nmol/30' on day 21. Maximal increase in sPLA2 mRNA in paws, lung and aorta was observed on day 14, and in the lymph nodes and spleen on day 28. In the liver, trace levels were found with no corresponding protein expression. In paws, lung, aorta and lymph nodes maximum increase in sPLA2 protein was noted on day 14 whereas the spleen showed constant sPLA2 protein level during AA. cPLA2 mRNA detected in all organs, did not significantly change during the course of AA, with the exception of regional lymph nodes where the message increased between 14 and 28 day. Induction of mRNA and protein of sPLA2 in several organs is an evidence that AA is a systemic inflammatory process. The parallelity of the sPLA2 expression to the severity of inflammatory process, implies that sPLA2 may play pathogenic role in AA. Lack of enhancement of cPLA2 mRNA may mean that this enzyme is either not induced in AA, or it increases earlier in the course of the inflammatory process.


Subject(s)
Arthritis, Experimental/enzymology , Inflammation/enzymology , Phospholipases A/biosynthesis , Animals , Arthritis, Experimental/etiology , Arthritis, Experimental/genetics , Cytosol/enzymology , Gene Expression , Inflammation/etiology , Inflammation/genetics , Inflammation Mediators/metabolism , Male , Phospholipases A/genetics , Phospholipases A/metabolism , Phospholipases A2 , RNA, Messenger/genetics , RNA, Messenger/metabolism , Rats , Rats, Inbred Lew , Tissue Distribution
14.
Toxicology ; 117(1): 45-53, 1997 Feb 14.
Article in English | MEDLINE | ID: mdl-9020198

ABSTRACT

CrO3 was found to affect norepinephrine release in a biphasic manner: at concentrations above 100 microM, it inhibited, while at concentrations below 10 microM, it enhanced DMPP- and high K+-induced [3H]norepinephrine (NE) release from bovine adrenal medullary cells. Similar effects were found for K2Cr2O7. CrO3 inhibited the 45Ca2+ uptake induced by DMPP and high K+, suggesting that the voltage-gated Ca2+ channels are possible sites of the inhibitory action of CrO3. CrCl3, possessing a trivalent state in contrast to the hexavalent states of CrO3, K2Cr2O7, inhibited DMPP-induced [3H] release and inhibited, to a lesser extent, high K+-induced [3H]-NE release, suggesting that nicotinic receptors are also possible sites of Cr3+ action. In medullary cells permeabilized with digitonin, both CrO3 and CrCl3 induced [3H]-NE release from cells preloaded with [3H]-NE. In intact cells, CrO3 but not CrCl3 enhanced secretagogue-induced [3H]-NE release and entered into the cells as demonstrated by fluorescence quenching experiments. These results suggest that chromium compounds can induce catecholamine secretion after entering the cytoplasm. The enhancement of norepinephrine release induced by chromium ions appears to be due to interference with the intracellular functions of Ca2+ in the cytoplasm.


Subject(s)
Adrenal Medulla/drug effects , Adrenal Medulla/metabolism , Catecholamines/metabolism , Chromium Compounds/toxicity , Adrenal Medulla/cytology , Animals , Calcium/metabolism , Cattle , Cells, Cultured , Chlorides/toxicity , Norepinephrine/metabolism , Potassium Dichromate/toxicity , Time Factors
15.
J Rheumatol ; 23(7): 1162-6, 1996 Jul.
Article in English | MEDLINE | ID: mdl-8823686

ABSTRACT

OBJECTIVE: A limited retrospective study of patients with rheumatoid arthritis (RA) found that serum secreted phospholipase A2 (sPLA2) activity correlates with disease activity (J Rheumatol 1988; 15:1351-5). To assess the strength of this relationship we investigated prospectively 212 patients with RA using a double blind approach. METHODS: 212 patients who fulfilled the 1987 ACR criteria for RA had 420 clinical and laboratory assessments. 65 patients were assessed on one occasion and 147 on multiple occasions (a mean of 2.41 visits/patient). sPLA2 was tested by an independent investigator. RESULTS: sPLA2 activity assessed as a dichotomous variable (less or more than mean +/- 2 SD) correlated highly (p < 0.005) with Lansbury index, number of effusions, number of damaged joints, erythrocyte sedimentation rate (ESR), platelet count, and low hemoglobin. Univariate and multivariate regression analyses showed significant correlations with Lansbury index, active and effused joints, hemoglobin, platelet count, and ESR. The best correlation was observed in a multivariate model that included Lansbury index, ESR, and platelet count (r = 0.60). Analysis of longitudinal changes in sPLA2 activity in 147 patients assessed more than once showed that sPLA2 correlates significantly with Lansbury index, active and effused joints, and hemoglobin. CONCLUSION: Serum sPLA2 activity correlates significantly with Lansbury index, active and effused joints, ESR, platelet court, and hemoglobin. Thus, sPLA2 can serve as an index of disease activity in RA.


Subject(s)
Arthritis, Rheumatoid/enzymology , Phospholipases A/blood , Synovial Fluid/enzymology , Adolescent , Adult , Aged , Aged, 80 and over , Arthritis, Rheumatoid/blood , Arthritis, Rheumatoid/diagnosis , Biomarkers , Double-Blind Method , Enzyme Activation , Female , Humans , Joint Diseases/diagnosis , Joint Diseases/enzymology , Joint Diseases/physiopathology , Longitudinal Studies , Male , Middle Aged , Multivariate Analysis , Phospholipases A/metabolism , Phospholipases A2 , Prospective Studies , Regression Analysis
16.
Neurosci Lett ; 204(3): 181-4, 1996 Feb 09.
Article in English | MEDLINE | ID: mdl-8938260

ABSTRACT

Dehydroepiandrosterone sulfate (DHEAS) dose-dependently inhibited [3H]norepinephrine (NE) secretion and the corresponding [Ca2+]i rise induced by the nicotinic receptor agonist 1,1-dimethyl-4-phenylpoperazimium (DMPP) in bovine chromaffin cells. DHEAS at 10 microM, the physiological concentration in human serum, significantly inhibited both the release of [3H]NE and the rise of [Ca2+]i induced by DMPP in chromaffin cells. DHEAS also inhibited the [3H]NE release induced by the Na+ channel activator veratridine. However, DHEAS did not affect either the [3H]NE release, or the corresponding [Ca2+]i rise induced by high K+. Moreover, DHEAS suppressed the [Na+]i rise induced by either DMPP or high K+ as monitored by the fluorescence 340/380 ratio of SBFI loaded chromaffin cells. Our results suggest that the inhibitory effects of DHEAS on secretion mainly occur at nicotinic receptors as well as at the voltage-dependent Na+ channels.


Subject(s)
Adrenal Glands/cytology , Chromaffin System/cytology , Dehydroepiandrosterone Sulfate/pharmacology , Norepinephrine/antagonists & inhibitors , Adrenal Glands/metabolism , Animals , Benzofurans , Calcium/analysis , Catecholamines/antagonists & inhibitors , Catecholamines/metabolism , Cattle , Cells, Cultured/drug effects , Cells, Cultured/metabolism , Chromaffin System/drug effects , Chromaffin System/metabolism , Cytosol/chemistry , Dimethylphenylpiperazinium Iodide/pharmacology , Ethers, Cyclic , Fluorescent Dyes , Fura-2 , Ion Channel Gating/physiology , Nicotinic Agonists/pharmacology , Norepinephrine/metabolism , Sodium/analysis , Tritium/metabolism
17.
Toxicology ; 90(1-2): 81-91, 1994 May 31.
Article in English | MEDLINE | ID: mdl-8023345

ABSTRACT

The lethality of organophosphorous compounds has been attributed to their inhibitory effect on acetylcholinesterase (AChE) in the nervous system. However, subacute exposure of humans to organophosphates induces cognitive and emotional defects which might not solely be attributable to AChE inhibition. Therefore we investigated the toxic effects of methyl parathion and malathion on bovine adrenal chromaffin cells. Catecholamine secretion and 45Ca2+ uptake evoked by either a nicotinic agonist (DMPP) or high [K+] were inhibited by methyl parathion and malathion. The [Ca2+]i rise induced by DMPP was inhibited by both compounds. We conclude that in addition to AChE, voltage-gated Ca2+ channels and nicotinic receptors are possible sites of action of organophosphates in mammalian systems.


Subject(s)
Adrenal Medulla/drug effects , Calcium/metabolism , Malathion/toxicity , Methyl Parathion/toxicity , Norepinephrine/metabolism , Adrenal Medulla/cytology , Adrenal Medulla/metabolism , Animals , Calcium Channels/drug effects , Cattle , Cells, Cultured/drug effects , Cells, Cultured/metabolism , Chromaffin Granules/drug effects , Chromaffin Granules/metabolism , Ion Channel Gating/drug effects , Receptors, Nicotinic/drug effects , Receptors, Nicotinic/metabolism
SELECTION OF CITATIONS
SEARCH DETAIL
...