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1.
Zhonghua Kou Qiang Yi Xue Za Zhi ; 57(12): 1258-1265, 2022 Dec 09.
Artículo en Chino | MEDLINE | ID: mdl-36509529

RESUMEN

Periodontitis is the main cause of adult tooth loss, which seriously affects oral health and acts as a high-risk factor for varieties of systemic diseases. Gestational diabetes mellitus (GDM) is defined as glucose intolerance occurred or firstly identified during pregnancy. Prevalence of GDM is increasing over the past years worldwide. Besides adverse effects toward maternal and infant health in perinatal period, GDM also has long-term effects. Current studies have demonstrated that there is a bidirectional relationship between periodontitis and diabetes; however, the exact relationship between periodontitis and GDM remains elusive. In this paper, first reviewed the clinical association of periodontitis and GDM, and then discussed the underlying mechanisms of the two diseases, finally summarized the positive effect of periodontal therapy in controlling GDM. This paper will provide theoretical basis for the prevention diagnosis and therapy for the related diseases, promoting the maternal and infant health.


Asunto(s)
Diabetes Gestacional , Periodontitis , Embarazo , Adulto , Femenino , Humanos , Diabetes Gestacional/diagnóstico , Diabetes Gestacional/prevención & control , Periodontitis/complicaciones , Factores de Riesgo , Estudios de Casos y Controles
2.
Zhonghua Kou Qiang Yi Xue Za Zhi ; 57(6): 569-575, 2022 Jun 09.
Artículo en Chino | MEDLINE | ID: mdl-35692000

RESUMEN

Objective: To explore the effects of periodontitis and inflammatory factors toward the occurrence of gestational diabetes mellitus (GDM). Methods: Pregnant women who came to the Department of Obstetrics, Northwest Women's and Children's Hospital for prenatal examinations during March to November of 2021 were invited to participate in this study. Participants with GDM who met the inclusion criteria (n=100) were assigned into the case group; while healthy participants (n=100) were assigned into the control group. Information of participants from the two groups were collected by questionnaires and periodontal statuses were clinically recorded in the meantime. Gingival crevicular fluid (GCF) and venous blood were also collected from participants of two groups to analyze the expression levels of inflammatory factors like C-reactive protein (CRP), tumor necrosis factor-α (TNF-α), interleukin (IL)-1ß, IL-6, IL-8, IL-10 and IL-33. Factors different between the two groups were included in the multivariate regression analysis model to determine the risk factors of GDM. Results: The age of participants was (33.4±5.1) years in case group and (30.5±4.5) years in control group respectively, which had statistical differences (t=4.33,P<0.001). Besides, the body mass index of participants from case group was also significantly higher than control group [(28.11±3.85) kg/m2 vs. (23.31±3.15) kg/m2, t=9.65, P<0.001]. Participants with GDM had more adverse periodontal clinical parameters. Prevalence of periodontitis in GDM group was 47.0% (47/100) compared with 29.0% (29/100) in control group (χ²=6.88, P=0.009). Multivariate regression analysis results indicated that periodontitis was a critical risk factor for the occurrence of GDM (OR=1.882, P<0.001). Besides, GCF IL-8, serum TNF-α, IL-8 and IL-10 were also risk factors of GDM due to their higher expressions. Among them, TNF-α in serum (OR=2.077) and IL-8 in serum (OR=2.060) had more significant impacts (P<0.001). Conclusions: This study demonstrated that periodontitis was associated with the occurrence of GDM. Up-regulation of serum pro-inflammatory mediators leaded by local periodontal inflammatory microenvironment might play a critical role in this pathological process.


Asunto(s)
Diabetes Gestacional , Periodontitis , Adulto , Estudios de Casos y Controles , Femenino , Líquido del Surco Gingival/química , Humanos , Interleucina-10/análisis , Interleucina-8 , Periodontitis/complicaciones , Embarazo , Factor de Necrosis Tumoral alfa
3.
Eur Rev Med Pharmacol Sci ; 25(1): 127-138, 2021 01.
Artículo en Inglés | MEDLINE | ID: mdl-33506900

RESUMEN

OBJECTIVE: Nasopharyngeal carcinoma (NPC) is a common cancer with high incidence in Southern China. Taxol is one of the first-line chemotherapeutic drugs for treating NPC; however, Taxol resistance has become the main difficulty for clinical treatment and the mechanisms remain not fully understood. In this study, we mainly focus on exploring whether exosomes from Taxol-resistant NPC cells played some roles in the resistance and progression of NPC. MATERIALS AND METHODS: Taxol was used to treat NPC cell line CNE1 and Taxol-resistant NPC cell line CNE1-TR cells to measure cell viability and IC50 by CCK-8 assay. Exosomes from these two cells were extracted and identified by transmission electron microscopy (TEM), and special protein markers were determined by Western blot (WB) assay. Real-time PCR was performed to detect levels of mRNAs in exosomes, CNE1 and CNE1-TR cells. WB was performed to detect protein levels. The p-DDX53 and si-DDX53 were constructed and cloned into cells, resulted with DDX53 overexpression and inhibition, then resistant associated protein levels and IC50 were measured. Finally, GW4869, an inhibitor to block exosome secretion, was used to verify that the exosomes derived from CNE1-TR cells transferred DDX53 to CNE1 cells and contributed to promote NPC resistance. RESULTS: We found that the IC50 to Taxolin CNE1-TR was much higher than that in CNE1 cells and DDX53 was highly expressed in Taxol-resistant CNE1-TR cells. Furthermore, exosomes were successfully extracted and determined, showing high levels of DDX53 and MDR1. Thus, they could promote cell resistance for CNE1 after adding CNE1-TR exosomes into CNE1 cells. Moreover, DDX53 overexpression increased the IC50 and upregulated MDR1 in CNE1 cells, while DDX53 inhibition showed the opposite results. In addition, the DDX53 inhibition decreased the IC50 and repressed MDR1 in CNE1-TR cells. Besides, blocking exosome released from CNE1-TR by using GW4869 treatment significantly repressed the levels of DDX53 and MDR1, and the IC50 of CNE1 cells was reversed. Finally, the increased levels of MDR1 were significantly reversed following with adding DDX53 si-DDX53-CNE1-TR exosomes, and the increased IC50 to Taxol was obviously reversed. CONCLUSIONS: This study firstly discovered that DDX53 was highly expressed in Taxol-resistant NPC cells, which could be transferred into normal NPC cells via exosome secretion. The transferred DDX53 could upregulate the expression of MDR1 in NPC cells to promote the resistant capacity to Taxol, which provided a novel insight for understanding NPC and might be a potential therapeutic target for NPC.


Asunto(s)
Antineoplásicos Fitogénicos/farmacología , ARN Helicasas DEAD-box/metabolismo , Resistencia a Antineoplásicos/efectos de los fármacos , Exosomas/metabolismo , Carcinoma Nasofaríngeo/metabolismo , Neoplasias Nasofaríngeas/metabolismo , Paclitaxel/farmacología , Compuestos de Anilina/farmacología , Compuestos de Bencilideno/farmacología , ARN Helicasas DEAD-box/genética , Exosomas/efectos de los fármacos , Humanos , Carcinoma Nasofaríngeo/tratamiento farmacológico , Carcinoma Nasofaríngeo/patología , Neoplasias Nasofaríngeas/tratamiento farmacológico , Neoplasias Nasofaríngeas/patología , Células Tumorales Cultivadas
4.
Zhonghua Gan Zang Bing Za Zhi ; 28(12): 1008-1012, 2020 Dec 20.
Artículo en Chino | MEDLINE | ID: mdl-34865347

RESUMEN

Objective: To study the virological and serological indicators before treatment and 24 weeks after treatment to predict the partial virological response (PVR) of 48-week entecavir (ETV) treatment, and formulate early clinical adjustment treatment plans for HBeAg-positive CHB patients. Methods: HBeAg-positive CHB-naïve patients diagnosed in the Department of Infectious Diseases, Shengjing Hospital, China Medical University, who were treated with oral ETV monotherapy from January 2018 were enrolled. The groups were divided according to the test results of HBV DNA at 48 weeks. Among them, HBV DNA < 20 IU/ml was the complete viral response (CVR) group, and HBV DNA ≥ 20 IU/ml was the PVR group. The virological and serological indexes of the two groups before treatment and 24 weeks after treatment were compared. ROC curve univariate analysis and multivariate logistic regression were performed to find out the early predictors of PVR in HBeAg-positive CHB patients receiving ETV therapy for 48 weeks. Results: As of July 2020, a total of 90 cases had completed 48 weeks of treatment, including 50 cases of CVR (55.56%) and 40 cases of PVR (44.44%). Before treatment and at 24 weeks of treatment, HBsAg, HBeAg and HBV DNA in the PVR group were significantly higher than those in the CVR group (P < 0.001). Univariate analysis showed that HBV DNA quantification (AUC = 0.961, P < 0.001, PPV = 97.06%, NPV = 87.50%) and HBeAg quantification (AUC = 0.883, P < 0.001, PPV = 90.63%, NPV = 81.03%) had higher predictive value at 24 weeks of treatment. Multivariate analysis showed that HBeAg > 1.952 log(10) S/CO (OR = 3.177, 95% CI: 1.261 ~ 8.267, P = 0.018) and HBV DNA > 2.205 log(10) IU / ml (OR = 43.197, 95% CI: 6.858 ~ 272.069, P < 0.001) were independent predictors of PVR at 24 weeks of treatment, and their combination had the best predictive effect. Conclusion: In HBeAg-positive CHB patients receiving ETV treatment for 48 weeks, HBV DNA combined with HBeAg quantification can be an early predictor of PVR at 24 weeks. Additionally, patients with both HBV DNA and HBeAg > 2 log(10) at 24 weeks of treatment must wait 48 weeks to obtain CVR, so it is recommended that treatment strategies should be adjusted at this time.


Asunto(s)
Antígenos e de la Hepatitis B , Hepatitis B Crónica , Antivirales/uso terapéutico , Guanina/análogos & derivados , Hepatitis B Crónica/tratamiento farmacológico , Humanos , Resultado del Tratamiento
5.
Genet Mol Res ; 14(3): 10490-9, 2015 Sep 08.
Artículo en Inglés | MEDLINE | ID: mdl-26400280

RESUMEN

We evaluated changes in BAX and BCL2 expression levels after spinal cord ischemia/reperfusion injury (SCII) and hypothermia during operations in rats. Eighty rats were divided into four groups: Group A (N = 20, 18°C); Group B (N = 20, 28°C); Group C (N = 20, room temperature); and Group D (N = 20, sham operation control). Spinal cord ischemia was induced for 90 min. Hypothermia was induced 15 min before, and maintained during ischemia, followed by heating to normothermia for 30 min after reperfusion. Motor function of the lower limbs was evaluated according to the Tarlov score at 72 and 168 h. For each rat, spinal cord samples were taken at 6, 24, 72 h, and 1 week to evaluate the histopathological changes, neuronal apoptosis, and BAX and BCL2 expression levels. Compared with normothermia, hypothermia significantly improved hind limb function; Group B achieved a higher score than Group A. Group D showed no neurologic deficiency, while the other groups showed various degrees. Group C exhibited greater neuronal apoptosis, higher BAX expression, but lower BCL2 expression than the other groups. Compared with Group A, BAX was expressed less and BCL2 more in Group B, and there was less apoptosis in Group B. Hypothermia preserves hind limb motor function and reduces neuronal death, thereby protecting rats from SCII. The spinal cord may be protected from SCII by inhibition of BAX and activation of BCL2. However, deep hypothermia may inhibit the expression of BCL2, resulting in a worse outcome than mild hypothermia.


Asunto(s)
Proteínas Proto-Oncogénicas c-bcl-2/genética , Daño por Reperfusión/genética , Daño por Reperfusión/prevención & control , Isquemia de la Médula Espinal/genética , Médula Espinal/metabolismo , Proteína X Asociada a bcl-2/genética , Animales , Apoptosis/genética , Frío , Regulación de la Expresión Génica , Miembro Posterior/irrigación sanguínea , Miembro Posterior/fisiopatología , Masculino , Actividad Motora/fisiología , Neuronas/metabolismo , Neuronas/patología , Proteínas Proto-Oncogénicas c-bcl-2/metabolismo , Ratas , Ratas Sprague-Dawley , Daño por Reperfusión/metabolismo , Daño por Reperfusión/fisiopatología , Médula Espinal/patología , Isquemia de la Médula Espinal/metabolismo , Isquemia de la Médula Espinal/patología , Isquemia de la Médula Espinal/fisiopatología , Proteína X Asociada a bcl-2/metabolismo
6.
Nanoscale ; 4(4): 1304-7, 2012 Feb 21.
Artículo en Inglés | MEDLINE | ID: mdl-22241243

RESUMEN

With structural miniaturization down to the nanoscale, the detectable quantities of solid materials no longer remain constant but become tunable. For the II-VI semiconductors example, the band gap expands, the elastic modulus increases, the melting point drops, and the Raman optical phonons experience red shift associated with creation of low frequency Raman acoustic modes that undergo blue shift with decreasing the dimensional scale. In order to understand the common origin of the size dependency of these seemingly irrelevant properties, we formulated these quantities for CdS, ZnS, and CdSe semiconductors from the perspectives of bond order-length-strength correlation and the local bond averaging approach. Consistency between the theory predictions and the measured size dependence of these quantities clarified that the undercoordination-induced local strain and quantum entrapment and the varied fraction of undercoordinated atoms of the entire solid correlate these quantities and dominate their size effect.

7.
Nanoscale ; 4(2): 502-10, 2012 Jan 21.
Artículo en Inglés | MEDLINE | ID: mdl-22105904

RESUMEN

From the perspective of bond relaxation and bond vibration, we have formulated the Raman phonon relaxation of graphene, under the stimuli of the number-of-layers, the uni-axial strain, the pressure, and the temperature, in terms of the response of the length and strength of the representative bond of the entire specimen to the applied stimuli. Theoretical unification of the measurements clarifies that: (i) the opposite trends of the Raman shifts, which are due to the number-of-layers reduction, of the G-peak shift and arises from the vibration of a pair of atoms, while the D- and the 2D-peak shifts involve the z-neighbor of a specific atom; (ii) the tensile strain-induced phonon softening and phonon-band splitting arise from the asymmetric response of the C(3v) bond geometry to the C(2v) uni-axial bond elongation; (iii) the thermal softening of the phonons originates from bond expansion and weakening; and (iv) the pressure stiffening of the phonons results from bond compression and work hardening. Reproduction of the measurements has led to quantitative information about the referential frequencies from which the Raman frequencies shift as well as the length, energy, force constant, Debye temperature, compressibility and elastic modulus of the C-C bond in graphene, which is of instrumental importance in the understanding of the unusual behavior of graphene.


Asunto(s)
Carbono/química , Grafito/química , Nanoestructuras/química , Nanoestructuras/ultraestructura , Espectrometría Raman/métodos , Sitios de Unión , Fuerza Compresiva , Elasticidad , Sustancias Macromoleculares/química , Ensayo de Materiales , Conformación Molecular , Tamaño de la Partícula , Estrés Mecánico , Propiedades de Superficie , Resistencia a la Tracción , Temperatura de Transición
8.
J Phys Chem B ; 114(4): 1648-51, 2010 Feb 04.
Artículo en Inglés | MEDLINE | ID: mdl-20055382

RESUMEN

An analytical form connecting the energy shift of Raman modes directly to the bonding identities (order, nature, length, energy) of a specimen and the response of the bonding identities to the applied stimuli of temperature and pressure was presented for a deeper understanding of the atomistic origin of the ZnO Raman shift. Theoretical reproduction based on the BOLS correlation theory [Sun, C. Q. Prog. Solid State Chem. 2007, 35, 1] and the local bond average (LBA) approach [Sun, C. Q. Prog. Mater. Sci. 2009, 54, 179] of the measurements revealed that the thermally softened ZnO Raman modes arise from bond expansion and bond weakening due to vibration and that the pressure-stiffened Raman modes result from bond compression and bond strengthening due to mechanical work hardening. The developed approach could be useful in generalizing the lattice dynamics directly to the process of vibration and relaxation of a representative bond of the specimen under external stimuli.

9.
Vet J ; 182(1): 79-85, 2009 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-18602849

RESUMEN

Immunoglobulin (Ig) G1 concentrations in milk from Holstein cows was measured to determine if transfer and concentration was influenced by production factors (lactation number, stage of lactation, daily milk production), milk composition (milk fat, protein, lactose, and total solids content) or by serum IgG1 concentration. Two hundred and ninety-nine Chinese Holstein cows were randomly selected from four herds containing a total of more than 1600 lactating animals. The concentration of IgG1 in the milk and serum was determined by ELISA. Milk IgG1 concentrations varied between 0.030 and 0.614 mg/mL and significantly correlated with lactation number, stage of lactation, daily milk production and somatic cell count. The IgG1 mass was found to highly correlate with lactation number, stage of lactation, daily milk production and milk protein content. Lactation number had the highest positive direct relationship with IgG1 concentration.


Asunto(s)
Bovinos/inmunología , Inmunoglobulina G/análisis , Lactancia/inmunología , Leche/inmunología , Animales , Bovinos/sangre , Recuento de Células/veterinaria , Ensayo de Inmunoadsorción Enzimática/veterinaria , Grasas/análisis , Femenino , Inmunoglobulina G/sangre , Leche/química , Leche/citología , Leche/metabolismo , Proteínas de la Leche/análisis , Paridad , Embarazo
10.
J Environ Sci (China) ; 13(3): 361-4, 2001 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-11590771

RESUMEN

Kinetic processes of alpha-naphthaleneacetic acid (NAA) photolysis were studied under different conditions. The results showed that the ultraviolet light was more effective than fluorescent light in promoting degradation, and the degradation of NAA under ultraviolet light followed the first order kinetics with the photolysis rate constant of 1.15 x 10(-2) min-1 and half-life time (t1/2) of 60 min. Further, it was proved that the photolysis rate was higher in the presence of oxygen, titanium dioxide (TiO2), and low pH (acidic solution). At last, two photolysis intermediates were identified by GC-MS and possible photolysis pathways were proposed.


Asunto(s)
Ácidos Naftalenoacéticos/química , Cinética , Ácidos Naftalenoacéticos/efectos de la radiación , Fotoquímica , Fotólisis , Soluciones , Agua
11.
Bioorg Med Chem ; 9(11): 2849-55, 2001 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-11597465

RESUMEN

Copper(II) complexes (Cu-L, L=N,N'-dialkyl-1,10-phenanthroline-2,9-dimethanamine) were synthesized and characterized by elemental analyses, IR spectra and conductance measurement. The interaction of the copper(II) complex with calf thymus DNA was studied by means of UV melting experiments, fluorescence spectra and circular dichroic spectra. Using ethidium bromide as a fluorescence probe, the binding mode of the complexes Cu-L with calf-thymus DNA was studied spectroscopically. The results indicate that the complexes Cu-L perhaps interact with calf-thymus DNA by both intercalative and covalent binding. Kinetics of binding of the cupric complexes to DNA was studied for the first time using ethidium bromide as a fluorescence probe with stopped-flow spectrophotometer under pseudo-first-order condition. The stronger binding of two steps in the process of the complexes Cu-L interacting with DNA was observed, and the probable interaction process was discussed in detail. The corresponding k(obs) and E(a) of binding to DNA (where k(obs) is the observed pseudo-first-order rate constant, E(a) is the observed energy of activation) were obtained.


Asunto(s)
Cobre/química , ADN/metabolismo , Compuestos Organometálicos/metabolismo , Aminas/química , Animales , Sitios de Unión , Dicroismo Circular , ADN/química , Cinética , Conformación de Ácido Nucleico/efectos de los fármacos , Compuestos Organometálicos/química , Fenantrolinas/química , Espectrometría de Fluorescencia , Temperatura , Termodinámica
12.
Anticancer Drug Des ; 15(6): 405-11, 2000 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-11716433

RESUMEN

Eight lanthanum(III) complexes with novel 1,10-phenanthroline-2,9-bis-alpha-amino acid conjugates were synthesized and characterized by elemental analyses, IR, MS, 1H-NMR, thermal analysis and conductance measurement. All lanthanum(III) complexes and the corresponding soluble ligand in water have been assayed for antitumor activity in vitro against HL-60 (human leukocytoma) cells, HCT-8 (human coloadenocarcinoma) cells, BGC-823 (human stomach carcinoma) cells, BeL-7402 (human liver carcinoma) cells and KB (human nasopharyngeal carcinoma) cells. The results show that several complexes have relative activity against different cell lines. In particular, the complexes La(L2) and La(L5) show relatively high activity against the BeL-7402 cell line. Moreover, they are slightly more effective than cisplatin. DNA binding studies indicate that the complex La(L2) possibly interacts with calf thymus DNA by both intercalative and covalent binding.


Asunto(s)
Aminoácidos/química , Antineoplásicos/química , Lantano/química , Compuestos Organometálicos/química , Fenantrolinas/química , Aminoácidos/síntesis química , Aminoácidos/farmacología , Antineoplásicos/síntesis química , Antineoplásicos/farmacología , Ensayos de Selección de Medicamentos Antitumorales , Humanos , Lantano/farmacología , Espectroscopía de Resonancia Magnética , Espectrometría de Masas , Compuestos Organometálicos/síntesis química , Compuestos Organometálicos/farmacología , Fenantrolinas/síntesis química , Fenantrolinas/farmacología , Espectrofotometría Infrarroja , Células Tumorales Cultivadas
13.
Zhonghua Liu Xing Bing Xue Za Zhi ; 18(1): 18-21, 1997 Feb.
Artículo en Chino | MEDLINE | ID: mdl-9812475

RESUMEN

Under cluster sampling, an early serum essay of helicobacterpylori (Hp) infection among 1084 healthy people, was carried out. Out of them, 325 among the Yi and Han Nationalities at Yunxian County of Yunnan Province were given a simultaneous test of anti-HAV IgG. The results were as follows: overall Hp infection rate was 51.1%; no difference of the infection was observed between the Yis and the Hans; the prevalence of Hp antibody went up with age; Higher rates were detected among those who drank river water or unboiled-water than among those who drank tap water, well water or boiled water, from poultry raisers than from non-poultry raisers and with drug abusers than with non-drug abusers. Hp infection showed a parallel relation to HAV infection. Finally, seven main epidemic factors were sifted from multi-factor logistic analysis namely source of drinking water, drinking habit, chicken-raising, pig-keeping, dog-breeding, drug-abusing and consumption of garlic. All these findings suggested that drinking water was an important vehicle of Hp infection. Our research data seems to have lend support to both fecal- oral transmission viewpoint and the hypothesis that Hp infection derives from animals. Frequent intake of garlic may serve as an agent in long-term prevention of Hp infection among people in this area.


Asunto(s)
Infecciones por Helicobacter/epidemiología , Helicobacter pylori , Adolescente , Adulto , Factores de Edad , Niño , Preescolar , China/epidemiología , Etnicidad , Femenino , Infecciones por Helicobacter/etnología , Humanos , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Muestreo , Trastornos Relacionados con Sustancias/complicaciones , Abastecimiento de Agua
14.
Zhongguo Yao Li Xue Bao ; 16(5): 396-8, 1995 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-8701751

RESUMEN

AIM: To study pharmacokinetics of tablet huperzine A (Hup-A) in Chinese volunteers to help establishing its drug administration schedule. METHODS: For 6 volunteers after a single oral dose of 0.99 mg, drug concentrations in plasma were assayed by reverse phase high pressure liquid chromatography (HPLC) at 0.5, 0.75, 1.0, 1.25, 1.5, 2, 4, 6, 8, and 10 h. The pharmacokinetic parameters were calculated with a 3P87 program by computer. RESULTS: The time course of plasma concentrations conformed to a one-compartment open model with a first order absorption. The pharmacokinetic parameters were as follows: T 1/2ka = 12.6 min, T 1/2ke = 288.5 min, Tmax = 79.6 min, Cmax = 8.4 micrograms L-1, AUC = 4.1 mg L-1 min. CONCLUSION: Hup-A was absorbed rapidly, distributed widely in the body, and eliminated at a moderate rate.


Asunto(s)
Inhibidores de la Colinesterasa/farmacocinética , Sesquiterpenos/farmacocinética , Adulto , Alcaloides , Cromatografía Líquida de Alta Presión/métodos , Femenino , Humanos , Masculino , Comprimidos
15.
Biomed Environ Sci ; 7(4): 362-8, 1994 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-7702767

RESUMEN

Six hundred and thirty-four food samples of six kinds were collected from Beijing, Shanghai, Jiangsu, Sichuan, Jilin and Guangdong areas, China and Hg, Pb, Cd contents were determined. The results showed that their levels in the Chinese foods were low; their levels in meat, egg, milk and fish were generally below the national hygienic standard. The average daily dietary intake of Hg, Pb, Cd were 7.25 micrograms, 103.77 micrograms and 30.72 micrograms respectively and they were all less than the ADI established by WHO.


Asunto(s)
Cadmio/análisis , Contaminación de Alimentos , Plomo/análisis , Mercurio/análisis , Adulto , China , Dieta , Contaminación de Alimentos/legislación & jurisprudencia , Humanos , Espectrofotometría Atómica
16.
Ann N Y Acad Sci ; 637: 152-63, 1991.
Artículo en Inglés | MEDLINE | ID: mdl-1785769

RESUMEN

Leydig cell progenitors contain significant concentrations of androgen receptors. When the metabolism of DHT to 3 alpha-DIOL is blocked, DHT stimulates testosterone production by Leydig cell progenitors, most probably via an androgen receptor dependent mechanism. Rapid metabolism by 3 alpha-HSD may limit the potency of exogenous DHT to stimulate differentiation of Leydig cell progenitors in vitro. Insulin-like growth factor-I enhances androgen production by purified immature Leydig cells. The elevated sensitivity of immature Leydig cells versus adult Leydig cells to IGF-I stimulation indicates that this peptide hormone has a role in their differentiation during puberty.


Asunto(s)
Andrógenos/fisiología , Células Intersticiales del Testículo/citología , Andrógenos/metabolismo , Animales , Diferenciación Celular , Dihidrotestosterona/metabolismo , Factor I del Crecimiento Similar a la Insulina/fisiología , Masculino , Ratas , Receptores Androgénicos/metabolismo , Testosterona/metabolismo , Testosterona/fisiología
17.
J Androl ; 11(3): 233-9, 1990.
Artículo en Inglés | MEDLINE | ID: mdl-2143504

RESUMEN

To investigate whether endogenous opioid peptides (EOP) play an important role in intragonadal regulation of testicular function and regulation of the hypothalamic-pituitary-gonadal axis of the male rat, the authors employed two principal methods: culture of testicular Leydig cells and Sertoli cells, and in vitro perifusion of hypothalamo-pituitary Leydig cells of the adult rat. The results demonstrated that incubation of Leydig cells with B-endorphin (B-EP 10(-9) = 10(-6) mol/L) or naloxone (NAL 10(-5) = 10(-8) mol/L) manifested no significant changes of non-stimulated or hCG-stimulated testosterone secretion both in 20 and 60 day-old rats. Similar results were obtained when the cells were treated with B-EP (10(-10) = 10(-7) mol/L) for 48 h during culture. Pretreatment of incubated Leydig cells with B-EP in similar concentrations for 48 h showed no effect on the response to hCG stimulation. In addition, treatment with B-EP in vitro for 24 or 72 h manifested no effects on estradiol production by aromatization of cultured Sertoli cells. Neither NAL 10(-5) given in vitro nor NAL (5 mg/body weight) injected subcutaneously 1 h before decapitation affected LH and testosterone release from the perifused hypothalamo-pituitary Leydig cells system. These results could not support the hypothesis that B-EP is a local regulator of testicular function. The physiological significance of EOP in regulating the function of gonadal axis of adult male rat remains to be investigated further.


Asunto(s)
Células Intersticiales del Testículo/metabolismo , Naloxona/farmacología , Células de Sertoli/metabolismo , Testosterona/metabolismo , betaendorfina/fisiología , Animales , Aromatasa/metabolismo , Células Cultivadas , Hipotálamo/fisiología , Células Intersticiales del Testículo/efectos de los fármacos , Hormona Luteinizante/metabolismo , Masculino , Perfusión , Hipófisis/fisiología , Ratas , Ratas Endogámicas , Células de Sertoli/efectos de los fármacos , Células de Sertoli/enzimología
18.
Sheng Li Xue Bao ; 41(4): 388-94, 1989 Aug.
Artículo en Chino | MEDLINE | ID: mdl-2602948

RESUMEN

We have reported that intracerebroventricular (i. c. v.) injection of 1-4 ng of CCK-8 to the rat produced a remarkable antagonistic effect on morphine analgesia. In order to study the species specificity and the site of action, CCK-8 was microinjected into the PAG of the rabbit, and its influence on morphine analgesia and electroacupuncture analgesia was observed. The latency of the escape response (ERL) to radiant heat focused on the snout was measured as an index of the pain threshold. Microinjections were made via cannulae chronically implanted into the PAG. The drug solutions were delivered in a volume of 1 microliter, at a speed of 0.125 microliter/min. The ERL was measured for a period of 60 or 70 minutes at 10 min intervals. 1. CCK-8 administered unilaterally to the PAG of the rabbit at a dose of 3 ng antagonized the analgesia induced by morphine (4 mg/kg, i. v.) by 73% (P less than 0.001), and reduced the analgesic effect of electroacupuncture by 67% (P less than 0.001). These effects were dose-dependent within the range from 1.5 ng to 6.0 ng. The effect of CCK-8 was reversed by CCK receptor blocker proglumide (4 microliters, intra-PAG injection). Unsulfated CCK-8 (CCK-us) had no effect in this regard. These results indicate that in the PAG of the rabbit, exogenously administered CCK-8 was capable of antagonizing opioid analgesia by the activation of CCK receptors. 2. Two groups of rabbits were given with morphine (2 mg/kg, i. v.) and simultaneous injection of CCK-8 antiserum (CCK-AS, 1 microliter) or normal rabbit serum (NRS) into the PAG.(ABSTRACT TRUNCATED AT 250 WORDS)


Asunto(s)
Analgesia por Acupuntura , Electroacupuntura , Morfina/antagonistas & inhibidores , Sustancia Gris Periacueductal/fisiología , Sincalida/farmacología , Animales , Inyecciones Intraventriculares , Masculino , Conejos , Sincalida/administración & dosificación
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