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1.
Bull Exp Biol Med ; 177(1): 15-21, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38954298

RESUMEN

Coronary heart disease (CHD) is related to aberrant aggregation of immune cells in the plaques. This study focused on identification of abnormal T cell subtypes and inflammatory factors in CHD patients. To this end, the subtypes of T cells in peripheral blood of CHD patients (n=141) and healthy controls (n=46) were analyzed by flow cytometry. Plasma concentrations of cytokines were analyzed by multiplex assay. It was shown that the number of T helper cells producing granulocyte-macrophage CSF (GM-CSF) was higher in CHD patients in comparison with healthy controls. In addition, the fractions of Th1 and Th17 cells as well as the levels of IL-4, IL-5, IL-6, and IL-10 in CHD patients also surpassed the control values (p<0.05). However, the level of GM-CSF was insignificantly lower in CHD patients. Thus, we revealed a relationship between the number of T cells producing GM-CSF and the severity of CHD. Our results can be used to develop new potential biomarkers for CHD detection.


Asunto(s)
Biomarcadores , Enfermedad Coronaria , Factor Estimulante de Colonias de Granulocitos y Macrófagos , Interleucina-6 , Humanos , Factor Estimulante de Colonias de Granulocitos y Macrófagos/sangre , Factor Estimulante de Colonias de Granulocitos y Macrófagos/metabolismo , Masculino , Femenino , Enfermedad Coronaria/inmunología , Enfermedad Coronaria/sangre , Persona de Mediana Edad , Biomarcadores/sangre , Interleucina-6/sangre , Estudios de Casos y Controles , Interleucina-10/sangre , Células Th17/inmunología , Células Th17/metabolismo , Células TH1/inmunología , Células TH1/metabolismo , Interleucina-4/sangre , Anciano , Linfocitos T Colaboradores-Inductores/inmunología , Linfocitos T Colaboradores-Inductores/metabolismo , Adulto , Citometría de Flujo , Interleucina-5
2.
Zhonghua Yan Ke Za Zhi ; 60(5): 408-415, 2024 May 11.
Artículo en Zh | MEDLINE | ID: mdl-38706078

RESUMEN

Objective: To compare the medium-term therapeutic effects of Kahook Dual Blade (KDB) goniotomy and Trabectome surgery in the treatment of patients with primary open-angle glaucoma (POAG). Methods: This study was a non-randomized prospective interventional controlled clinical study. POAG patients who underwent KDB goniotomy or Trabectome surgery at Beijing Tongren Hospital from May 2017 to April 2022 were enrolled. The definition of successful surgery was postoperative average intraocular pressure (IOP)≤21 mmHg (1 mmHg=0.133 kPa) and IOP decrease≥20%. Follow-up visits were conducted on the 1st day, 1st week, 1st, 3rd and 6th month after surgery. The IOP value, the number of IOP-lowering medications, the proportion of surgical success (average IOP≤21 mmHg at 6 months), and complications were evaluated. Statistical methods included independent sample t-test, Mann-Whitney rank sum test, χ2 test, repeated measures two-factor analysis of variance, Bonferroni, Friedman M test, Wilcoxon, and Log-rank. The Kaplan-Meier method was used to calculate the cumulative success rate of each group. Results: Seventeen male patients (17 eyes) and 10 female patients (10 eyes) were included. The mean age was (39.9±17.7) years old. There were 11 patients in the KDB group and 16 patients in the Trabectome group. There was no significant difference in clinical baseline conditions between the two groups (P>0.05). The IOPs in the KDB and Trabectome groups at postoperative 1 week [(16.6±6.3) and (16.4±4.1) mmHg) and 6 months [(17.8±5.3) and (19.9±4.4) mmHg) were lower than those before surgery [(25.1±9.3) and (27.4±9.1) mmHg) (all P<0.05). There was no significant difference in the overall IOP between groups (P>0.05). The IOP reduction rates in the KDB and Trabectome groups were 23.4% and 19.0%, with no significant difference (P=0.674). The numbers of IOP-lowering medications used in the KDB and Trabectome groups at 3 months [2.0 (1.0, 4.0) and 2.0 (1.0, 2.3)] and 6 months [2.0 (0.0, 4.0) and 2.0 (1.0, 3.0)] after surgery were not significantly different from those before surgery [4.0 (2.0, 4.0) and 3.0 (2.0, 4.0)] (both P>0.05). There was no statistical significance in the overall number of IOP-lowering medications used between the two groups (P>0.05). There was also no statistically significant difference in the proportion of patients with an IOP decrease of≥20% and the proportion of patients whose mean postoperative IOP was≤21 mmHg (all P>0.05). The proportions of IOP≤21 mmHg in the KDB group and the Trabectome group at 6 months after surgery were 81.8% and 68.8% (P>0.05). Serious intraoperative or postoperative complications occurred in neither group. Conclusions: Both KDB trabeculotomy and Trabectome surgery can effectively reduce IOP and have a good safety profile in treating POAG, with the same number of IOP-lowering medications.


Asunto(s)
Glaucoma de Ángulo Abierto , Presión Intraocular , Trabeculectomía , Humanos , Glaucoma de Ángulo Abierto/cirugía , Trabeculectomía/métodos , Estudios Prospectivos , Resultado del Tratamiento , Femenino , Masculino , Persona de Mediana Edad
3.
Zhonghua Yu Fang Yi Xue Za Zhi ; 53(7): 668-679, 2019 Jul 06.
Artículo en Zh | MEDLINE | ID: mdl-31288336

RESUMEN

Rabies is a zoonotic infectious disease caused by lyssavirus and characterized by central nervous system symptoms. The fatality rate of rabies is almost 100%. About 59 000 cases die of rabies worldwide every year, mainly in Asia and Africa. China is an epidemic country of rabies. Grade II and III exposures are the main types of rabies exposures in China. Standardized post-exposure prophylaxis (PEP) can prevent rabies almost 100%. Human Rabies Vaccine Technical Working Group, National Immunization Advisory Committee and invited experts reached an expert consensus on PEP by referring to the World Health Organization's position paper on rabies vaccine in 2018 and related research progress in recent.


Asunto(s)
Profilaxis Posexposición , Rabia/prevención & control , China/epidemiología , Consenso , Humanos , Rabia/epidemiología , Vacunas Antirrábicas/administración & dosificación
4.
Phys Rev Lett ; 118(11): 116402, 2017 Mar 17.
Artículo en Inglés | MEDLINE | ID: mdl-28368632

RESUMEN

We study the response of the one-dimensional charge density wave in K_{0.3}MoO_{3} to different types of excitation with femtosecond optical pulses. We compare direct excitation of the lattice at midinfrared frequencies with injection of quasiparticles across the low energy charge density wave gap and with charge transfer excitation in the near infrared. For all three cases, we observe a fluence threshold above which the amplitude-mode oscillation frequency is softened and the mode becomes increasingly damped. We show that all the data can be collapsed onto a universal curve in which the melting of the charge density wave occurs abruptly at a critical lattice excursion. These data highlight the existence of a universal stability limit for a charge density wave, reminiscent of the Lindemann criterion for the melting of a crystal lattice.

5.
Epidemiol Infect ; 144(1): 106-12, 2016 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-26081197

RESUMEN

Hepatitis G virus or GB virus C (GBV-C) is a human virus of the Flaviviridae family that is structurally and epidemiologically closest to hepatitis C virus, but replicates primarily in lymphocytes. Co-infection with GBV-C has been reported to confer beneficial outcomes in some HIV-positive patients. Up to now, however, studies on GBV-C infection in the central nervous system (CNS) of HIV-infected patient have rarely been reported. Herein, we report on a 32-year-old HIV-1-infected patient with cerebral toxoplasmosis and fungal encephalitis. GBV-C viral loads were detected in CSF by quantitative real-time reverse transcription polymerase chain reaction (RT-PCR), and the results showed that GBV-C viral load was 6·5 log copies/ml. We amplified and sequenced the E2 and 5'-untranslated regions from the purified viral RNA from CSF by RT-PCR. Both sequences belong to genotype 3 and there were some minor nucleotide divergence among the E2 sequences from the CSF of the patient. These data suggest that GBV-C may be able to penetrate the blood-brain barrier and colonize the CNS of HIV-infected patients. However, the exact mechanisms and potential effect of the infected GBV-C in CNS on HIV-associated neuropathy needs to be further explored.


Asunto(s)
Infecciones por Flaviviridae/líquido cefalorraquídeo , Virus GB-C/genética , Infecciones por VIH/complicaciones , Hepatitis Viral Humana/líquido cefalorraquídeo , ARN Viral/genética , Carga Viral , Adulto , China , Coinfección/microbiología , Coinfección/parasitología , Coinfección/virología , Infecciones por Flaviviridae/virología , Hongos/fisiología , Virus GB-C/clasificación , Virus GB-C/aislamiento & purificación , VIH-1/fisiología , Hepatitis Viral Humana/virología , Humanos , Encefalitis Infecciosa/microbiología , Masculino , Datos de Secuencia Molecular , Filogenia , ARN Viral/metabolismo , Análisis de Secuencia de ARN , Toxoplasma/fisiología , Toxoplasmosis Cerebral/parasitología , Viremia/líquido cefalorraquídeo , Viremia/virología
6.
Am J Transplant ; 14(11): 2460-6, 2014 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-25323029

RESUMEN

CD28 is a primary costimulation molecule for T cell activation. However, during the course of activation some T cells lose this molecule and assume a CD28-independent existence. These CD28- T cells are generally antigen-experienced and highly differentiated. CD28- T cells are functionally heterogeneous. Their characteristics vary largely on the context in which they are found and range from having enhanced cytotoxic abilities to promoting immune regulation. Thus, CD28 loss appears to be more of a marker for advanced differentiation regardless of the cytotoxic or regulatory function being conducted by the T cell. CD28- T cells are now being recognized as playing significant roles in several human diseases. Various functional CD28- populations have been characterized in inflammatory conditions, infections and cancers. Of note, the recent introduction of costimulation blockade-based therapies, particularly those that inhibit CD28-B7 interactions, has made CD28 loss particularly relevant for solid organ transplantation. Certain CD28- T cell populations seem to promote allograft tolerance whereas others contribute to alloreactivity and costimulation blockade resistant rejection. Elucidating the interplay between these populations and characterizing the determinants of their ultimate function may have relevance for clinical risk stratification and personal determination of optimal posttransplant immune management.


Asunto(s)
Antígenos CD28/inmunología , Linfocitos T/inmunología , Humanos
7.
Zhonghua Yi Shi Za Zhi ; 54(1): 10-16, 2024 Jan 28.
Artículo en Zh | MEDLINE | ID: mdl-38475680

RESUMEN

By systematically examing through Longdan Xiegan Decoction in medical books of the past dynasties, it was found that the Longdan Xiegan Decoction recorded in Lan Shi Mi Cang mainly targeted men's genital odor at frist. After Xue Ji's addition and subtraction, the scope of the prescription was gradually generalized and expanded, and confusion its name, composition and source of the prescription appeared, which was particularly prominent in Jingyue Quanshu and Yifang Jijie.Doctors used to interpret this prescription from the perspective of viscera. In order to better understand the main treatment rules of Longdan Xiegan Decoction, it is necessary to change the perspective and reinterpreted it from the perspective of meridians.Attributing the symptoms of the perineum to Liver Meridian of Foot-Jueyin,hypochondriac pain, deafness and other symptoms to the Gallbladder Meridian of Foot-Shaoyang, and adding or subtracting herbs according to the specific conditions, is not only conducive to a comprehensive and in-depth understanding of the prescription to achieve accurate clinical syndrome differentiation and medication, but also prompts modern researchers to rethink the important role of meridian theory in the formation and development of the theoretical system of traditional Chinese medicine.


Asunto(s)
Medicamentos Herbarios Chinos , Meridianos , Masculino , Humanos , Medicamentos Herbarios Chinos/uso terapéutico , Medicina Tradicional China , Prescripciones
8.
Zhonghua Liu Xing Bing Xue Za Zhi ; 41(11): 1808-1812, 2020 Nov 10.
Artículo en Zh | MEDLINE | ID: mdl-33297643

RESUMEN

Objective: To explore the spatio-temporal patterns and epidemic characteristics of imported dengue fever cases in six provinces (Yunnan, Guangxi, Guangdong, Hainan, Fujian and Zhejiang) of China from 2016 to 2018. Methods: In this study, we collected the surveillance data of imported dengue fever cases from 2016 to 2018 in six southern provinces of China. The risk intensity, spatio-temporal distribution and epidemiological characteristics of imported dengue fever cases in the six provinces were analyzed from the perspective of space, time and population. Results: Among the imported cases of dengue fever in China from other countries in the world, most of them were from Southeast Asia. In Zhejiang, Fujian and Guangdong provinces, there were greater number of imported cases with wide range of sources. While in Yunnan, Guangxi and Hainan provinces, the imported cases were almost from Southeast Asia. The incidence of imported dengue fever increased during the past three years, and the annual incidence peak was during August-November, but slight differences were observed among provinces. The age of the imported cases in Hainan[(37.0±19.6) years] was higher than that in southeastern coastal provinces[(36.0±11.7) years] and in southwestern provinces[(32.0±16.3) years]. The male-female ratio of the cases in southeastern coastal provinces (2.18∶1) were higher than those in southwestern provinces (1.04∶1) and Hainan (1.38∶1). The occupations of the cases were mainly workers and unemployed people in southeastern coastal provinces and farmers in southwestern provinces, but commercial personnel was the population with high incidence in both southeastern and southwestern provinces. Less imported dengue fever cases were reported in Hainan, the population distribution varied. Conclusions: There were differences in incidence pattern of imported dengue fever between southeastern coastal provinces and southwestern provinces as well as Hainan in China. Different prevention and control measures should be carried out in different areas to implement more precise prevention strategies.


Asunto(s)
Enfermedades Transmisibles Importadas , Dengue , Epidemias , Adulto , China/epidemiología , Enfermedades Transmisibles Importadas/epidemiología , Dengue/epidemiología , Femenino , Humanos , Incidencia , Masculino , Persona de Mediana Edad , Análisis Espacio-Temporal
9.
Animal ; 12(6): 1306-1315, 2018 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-29065941

RESUMEN

To explore the effects of maternal nutrition on offspring muscle characteristics, a total of 56 sows were assigned to one of the four dietary groups during gestation: control (CON), or control diets supplemented with methyl donor (MET), bisphenol A (BPA), and combined BPA and MET (BPA+MET). Compared with CON offspring, MET offspring showed a higher meat redness value, but lower glycogen content in the longissimus thoracis (LT). Moreover, compared with CON offspring, MET offspring showed lower LT glycogen synthase (GS) mRNA levels at birth and the finishing stage, and increased methylation at the GS promoter. Prenatal BPA exposure reduced the pH and redness value of meat, but increased the lightness value, lactate content, glycolytic potential and lactate dehydrogenase (LDH) enzyme activity in the LT muscle. Prenatal BPA exposure increased LDH mRNA levels in the LT muscle at birth and the finishing stage, and reduced methylation at the LDH promoter. Thus, maternal MET affects muscle GS and LDH expression via DNA methylation, thereby resulting in persistent effects on pork quality.


Asunto(s)
Compuestos de Bencidrilo , Fenoles , Efectos Tardíos de la Exposición Prenatal , Carne Roja , Porcinos , Animales , Compuestos de Bencidrilo/toxicidad , Femenino , Glucógeno Sintasa/metabolismo , Fenoles/toxicidad , Embarazo , ARN Mensajero/metabolismo , Porcinos/fisiología
10.
Biotechnol Adv ; 1(2): 229-45, 1983.
Artículo en Inglés | MEDLINE | ID: mdl-14540893

RESUMEN

A total of 77 references pertaining to the subject were consulted to compose the present review. In addition to their years of publication (1981-1983), the references were selected primarily for their practicality and ability to provide experimental results and confirmation. First, a generalized model illustrating the biochemical reaction engineering considerations is presented. Here the knowledge of reactor and reaction kinetics is emphasized and the need for process instrumentation identified. Recent developments in key process sensors are then discussed in detail along with their utilities in various process situations. Finally, application of control principles and on-line computers to biochemical process operation is given a realistic evaluation by considering the process dynamics and instrumentation capabilities. Future challenges and opportunities from both the reaction engineering and system engineering points of view are carefully assessed. The most recent review relevant to the subject is that by Bull (1983).

11.
Biotechnol Adv ; 9(4): 613-22, 1991.
Artículo en Inglés | MEDLINE | ID: mdl-14542051

RESUMEN

Colored dye wastewater presents a formidable task for biological treatment. Depending on how it is generated, wide pH spans and high salt concentrations such as chloride ion often add to the difficulties. Systematic screening for dye decolorizing and/or degrading bioagents from soil and water samples discovered fungi which show dramatic color removal capability (Shen, et al., 1990). One example shows that up to 99% reduction of light absorption at characteristic wavelength of a red dye (200 mg/L) could be obtained within 48 hours. This ability does not appear to be specific toward dyes targeted for action. It clarifies, often beyond detection by naked eyes, a repertoire of colored wastewater samples. These results appeared to be insensitive to wide variations in pH and salt concentration and, they are not limited to one particular fungal species or genus either upon further investigation. This dye adsorption mechanism may be of great significance in uncovering new methods for bio-removal or bio-recovery of dye substances in wastewater.

12.
Ann N Y Acad Sci ; 646: 259-72, 1991 Dec 27.
Artículo en Inglés | MEDLINE | ID: mdl-1809195

RESUMEN

Recombinant E. coli strains and culture conditions were studied for the fermentation expression of porcine somatotropin (PST) inclusion bodies under the control of a pL promoter. Our objective was to achieve high cell density together with a high level of recombinant protein expression. Improved fermentation conditions included oxygen enrichment, yeast extract (YE) effect, optimal specific growth to switch on gene expression, and feeding strategies. To maintain a low residual glucose concentration, a medium feed rate was controlled on a real-time basis by using cell density information estimated from on-line carbon dioxide monitoring of a fermentor's exhaust gas. The optimal specific growth rate required to initiate a temperature shift in our system was found to be around 0.2 hr-1. The cell density and PST expression level could reach 55 OD600 and 35%, respectively, after 16 hours of cultivation under optimal conditions by applying computer-controlled nutrient feed. In our recombinant host/vector system, the location of cl gene appears to affect gene expression under YE-supplemented and/or a high cell density culture condition. With cl gene placed on plasmid, our E. coli host no longer showed sensitivity toward YE in PST gene expression.


Asunto(s)
Escherichia coli/genética , Fermentación , Hormona del Crecimiento/biosíntesis , Animales , Clonación Molecular , Computadores , Electroforesis en Gel de Poliacrilamida , Escherichia coli/metabolismo , Expresión Génica , Vectores Genéticos , Hormona del Crecimiento/genética , Plásmidos , Porcinos , Levaduras
13.
Enzyme Microb Technol ; 14(4): 321-6, 1992 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-1368426

RESUMEN

Fermentation studies were performed on an Escherichia coli culture that carries a recombinant plasmid composed of an ampicillin-resistant gene, a temperature-regulated pL promoter, and a porcine pituitary cDNA sequence coding for growth hormone. The objective was to achieve high cell density while maintaining the specific expression level of recombinant porcine growth hormone (r-pGH) observed in shake flasks. At a specific expression level of 20% of total cell protein, the cell density of a glucose-limited fed-batch process reached 38 units of OD600 in 14 h, compared to flask cultivation, which resulted in only 1.4 units of OD600 in the same period. The observed critical fermentation conditions for maximal expression included (1) limiting glucose concentration below 1 g l-1 throughout the fed-batch growth and induction phases, (2) keeping postinduction temperature at 42 degrees C for 5-7 h, and (3) maintaining a postinduction growth rate around 0.17-0.21 h-1.


Asunto(s)
Ingeniería Genética/métodos , Hormona del Crecimiento/biosíntesis , Proteínas Recombinantes/biosíntesis , Animales , División Celular/efectos de los fármacos , Medios de Cultivo , Escherichia coli/crecimiento & desarrollo , Regulación Bacteriana de la Expresión Génica , Porcinos
14.
Chin Med J (Engl) ; 111(4): 309-12, 1998 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-10374393

RESUMEN

OBJECTIVE: To investigate the pathogenetic role of endogenous angiotensin II (Ang II) in the mechanism of stress ulcer in obstructive jaundice rats and to detect the effect of angiotensin converting enzyme inhibitor (ACEI) on stress ulcer in obstructive jaundice rats. METHODS: After common bile duct ligation (CBDL) in Wistar rats, the content of plasma and gastric mucosal Ang II, gastric mucosal blood flow (GMBF) and gastric mucosal damage were measured, and the relationship among them was analyzed. RESULTS: The plasma Ang II contents increased much more significantly at 1, 3, 7 and 14 days following CBDL than those in non-CBDL rats (P < 0.05, < 0.01, < 0.01 and < 0.01, respectively). Within 120 minutes following cold-restraint stress, plasma and gastric mucosal Ang II contents were elevated, GMBF decreased, and ulcer index and gastric mucosal damage increased more significantly than those in non-cold-restraint stress rats (P < 0.05, < 0.05, < 0.01, < 0.01 and < 0.05, respectively). Administration of an ACEI, enalaprili, to CBDL rats (5 mg.kg-1.day-1, orally for two days) before stress reduced both the plasma and gastric mucosal Ang II levels, inhibited the decrease of GMBF and decreased ulcer index and gastric mucosal damage (P < 0.001, < 0.01, < 0.01, < 0.01 and < 0.05, respectively). CONCLUSION: The endogenous Ang II plays a significant pathogenetic role in the development of stress ulcer in obstructive jaundice rats, and ACEI may prevent stress ulcer.


Asunto(s)
Angiotensina II/fisiología , Colestasis/metabolismo , Úlcera Gástrica/etiología , Estrés Fisiológico/complicaciones , Inhibidores de la Enzima Convertidora de Angiotensina/farmacología , Animales , Colestasis/complicaciones , Enalapril/farmacología , Masculino , Ratas , Ratas Wistar , Úlcera Gástrica/metabolismo
16.
Int J Neurosci ; 116(11): 1303-16, 2006 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-17000531

RESUMEN

To investigate the neuronal losses of hens' spinal cords in the model of organophosphate-induced delayed neuropathy (OPIDN) and to analyze the impact of apoptosis on the pathogenesis of OPIDN. Adult hens were challenged with triorthocresyl phosphate (TOCP) at a single dose (750 mg/kg). Neuronal losses in the 3rd lumbar spinal cord (L3) were assessed by light-microscopy and electron-microscopy methods at different days post exposure, respectively. The typical OPIDN signs were seen in the TOCP-exposed hens at about 9th day. The number of large nerve cells declined gradually. And these cells were verified as neurons by immunostained with neuronal marker NeuN. The expression of FasL reached proximal at about 9th day, decreased from 14th day. Neurons in TOCP exposed groups displayed degenerative morphologies in electronic microscopy. Some neurons showed apoptotic-like ultrastructure profiles at 5th day. The nuclear membrane was complete with chromatin condensed to the margins of nuclear membrane like a crescent-shaped body. Mitochondria morphologic changes appeared early (5 d) following exposure to TOCP, and developed in a time-dependent fashion. Apoptosis might be involved in the development of OPIDN, and play a role in the pathogenesis of OPIDN.


Asunto(s)
Exposición a Riesgos Ambientales/efectos adversos , Neuronas Motoras/efectos de los fármacos , Degeneración Nerviosa/inducido químicamente , Médula Espinal/efectos de los fármacos , Tritolilfosfatos/toxicidad , Administración Oral , Animales , Antígenos Nucleares/metabolismo , Apoptosis/efectos de los fármacos , Apoptosis/fisiología , Biomarcadores/metabolismo , Recuento de Células , Pollos , Modelos Animales de Enfermedad , Proteína Ligando Fas/metabolismo , Femenino , Inmunohistoquímica , Vértebras Lumbares , Microscopía Electrónica de Transmisión , Neuronas Motoras/patología , Degeneración Nerviosa/patología , Degeneración Nerviosa/fisiopatología , Proteínas del Tejido Nervioso/metabolismo , Neurotoxinas/toxicidad , Membrana Nuclear/efectos de los fármacos , Membrana Nuclear/patología , Médula Espinal/patología , Médula Espinal/fisiopatología
17.
Se Pu ; 15(4): 319-21, 1997 Jul.
Artículo en Zh | MEDLINE | ID: mdl-15739465

RESUMEN

A manual pre-column derivatization procedure has been developed for the determination of amino acids in sample by reversed-phase high performance liquid chromatography. OPA/3-mercaptopropionic acid (3-MPA) were used as derivatization reagents and separation of OPA-amino acids derivatives was performed on a 5 microm partical-size ODS column. A phosphate buffer of 10 mmol/L pH 7.2 (PB) containing 0.3% tetrahydrofuran (THF) was used as mobile phase (A) and a mixture of PB-methanol-acetonitrile (50:35:15) as mobile phase (B). A single linear gradient program was employed and the signals were detected at 340 nm with UV detector. Under the above conditions all 18 amino acids in standard solution were separated to baseline in 40 minutes. The precision of analysis was observed from the reproducibility of the retention times and peak areas of eight consecutive injections of 18 amino acids standard solution and the results showed that both retention times and peak areas were highly reproduceable with the RSD 0.09%-0.48% for retention times and 1.2%-4.9% for peak areas. The linearity of UV response was tested by injecting of derivatized amino acid with different concentrations from 25 to 250 micromol/L for each of 18 amino acids. The r values were 0.996-0.999. External standardization method was used for the quantitation. The method was applied to analyze amino acid composition of bovine serum albumin (BSA) and the results were in consistence with literature values. Free amino acids in rat plasma were also determined and good results were obtained.


Asunto(s)
Aminoácidos/análisis , Cromatografía Líquida de Alta Presión/métodos , Albúmina Sérica/análisis , o-Ftalaldehído/química , Ácido 3-Mercaptopropiónico/química , Animales , Bovinos , Cromatografía Líquida de Alta Presión/instrumentación , Plasma/química , Unión Proteica , Ratas
18.
Scand J Dev Altern ; 5(4): 5-24, 1986 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-12280787

RESUMEN

PIP: The authors analyze internal migration trends in Nigeria by examining individual household strategies and how they have adapted to structural changes brought about by colonial rule and capitalist development. The first section of this article describes the structural changes that started the process of labor migration. The second section deals with post-independence industrialization and the consequent rural-urban migration. The final section analyzes the consequences of these migration patterns for urban growth and rural productivity.^ieng


Asunto(s)
Colonialismo , Economía , Eficiencia , Emigración e Inmigración , Industrias , Sistemas Políticos , Dinámica Poblacional , Población Rural , Cambio Social , Urbanización , África , África del Sur del Sahara , África Occidental , Demografía , Países en Desarrollo , Geografía , Nigeria , Población , Características de la Población , Población Urbana
19.
Biotechnol Bioeng ; 25(1): 225-55, 1983 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-18548550

RESUMEN

A computer-aided methodology is developed for on-line monitoring and control of cell growth in fed-batch penicillin fermentation using a semidefined medium containing low corn steep liquor concentration (5.7 g/L). Cell growth is monitored and controlled with the use of experimental correlation and carbon-balancing equatiions on a real-time basis throughout the fermentation. Through a combination of feed-forward and feedback control of sugar addition, residual glucose concentration in the broth was maintained below 1 g/L and cell-growth rate was kept at constant at preset vaiues. The accuracy and reproducibility of this technique are demonstrated. The use of real-time control of cell growth is expected to aid future investigations of this antibiotic fermentation.

20.
Biotechnol Bioeng ; 25(1): 257-69, 1983 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-18548551

RESUMEN

To broaden the practicality of on-line growth monitoring and control, its application in fedbatch penicillin fermentation using high corn steep liquor (CSL) concentration (53 g/L) is demonstrated. By employing a calculation method that considers the vagaries of CSL consumption, overall and instantaneous carbon-balancing equations are successfully used to calculate, on-line, the cell concentration and instantaneous specific growth rate in the penicillin production phase. As a consequence, these equations, together with a feedback control strategy, enable the computer control of glucose feed and maintenance of the preselected production-phase growth rate with error less than 0.002 h(-1).

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