Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 35
Filtrar
Mais filtros

Base de dados
País/Região como assunto
Tipo de documento
Intervalo de ano de publicação
1.
J Viral Hepat ; 24(11): 1052-1066, 2017 11.
Artigo em Inglês | MEDLINE | ID: mdl-28581638

RESUMO

Hepatitis B virus (HBV) infection in the United States is the most common among Asians followed by non-Hispanic blacks. However, there have been few studies that describe HBV infection and immunity by racial group. Our study aimed to assess racial/ethnic disparities in the prevalence and awareness of HBV infection and immunity using nationally representative data. In the National Health and Nutrition Examination Survey 2011-2014, 14 722 persons had HBV serology testing. We estimated the prevalence of HBV infection, past exposure, and immunity by selected characteristics and calculated adjusted odds ratios using survey-weighted generalized logistic regression. Awareness of infection and vaccination history was also investigated. The overall prevalence of chronic HBV infection, past exposure and vaccine-induced immunity was 0.34% [95%CI 0.24-0.43], 4.30% [95%CI 3.80-4.81], and 24.4% [95%CI 23.4-25.4], respectively. The prevalence of chronic infection was 2.74% [95% CI 1.72-3.76] in Asians, 0.64% [95% CI 0.35-0.92] in non-Hispanic blacks, and 0.15% [95% CI 0.06-0.24] in non-Asian, non-blacks. Only 26.2% of those with chronic infection were aware of their infection. The prevalence of the past exposure was 21.5% [95%CI 19.3-23.7] in Asians, 8.92% [95%CI 7.84-9.99] in non-Hispanic blacks, 2.05% [95%CI 1.49-2.63] in non-Hispanic whites and 4.47% [95%CI 3.25-5.70] in Hispanics. Prevalence of vaccine-induced immunity by each race was 34.1% [95%CI: 32.0-36.2] in Asians, 25.5% [95%CI: 24.0-27.0] in non-Hispanic blacks, 24.0% [95%CI: 22.6-25.4] in non-Hispanic whites and 22.2% [95%CI: 21.3-23.3] in Hispanics. There are considerable racial/ethnic disparities in HBV infection, exposure and immunity. More active and sophisticated healthcare policies on HBV management may be warranted.


Assuntos
Conhecimentos, Atitudes e Prática em Saúde , Vírus da Hepatite B/imunologia , Hepatite B/epidemiologia , Hepatite B/imunologia , Imunidade , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Biomarcadores , Criança , Feminino , Anticorpos Anti-Hepatite B/imunologia , Antígenos de Superfície da Hepatite B/imunologia , Vacinas contra Hepatite B/imunologia , Humanos , Masculino , Pessoa de Meia-Idade , Vigilância da População , Prevalência , Estudos Soroepidemiológicos , Estados Unidos/epidemiologia , Estados Unidos/etnologia , Adulto Jovem
2.
Eur Surg Res ; 51(3-4): 146-55, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-24356183

RESUMO

BACKGROUND AND PURPOSES: Capsular contracture is one of the most severe complications that can occur in breast surgery following silicone implant insertion. The purpose of this study was to investigate the effect of montelukast and antiadhesion barrier solution (AABS) on reducing capsular formation and their possible synergism. MATERIALS AND METHODS: This study was approved by the Animal Ethics Committee (Reference No. KNU 2012-33) and was conducted in accordance with the Kyungpook National University - Institutional Animal Care and Use Committee, Animal Ethics Committee. The experiments in this study were conducted in vivo in 4 groups of 24 rats. Following silicone implant insertion, the pocket was injected with different agents. Group I (control group) was given normal saline injections into the pocket and fed with pure water. Group II was given injections of AABS and fed with pure water. Group III was given injections of normal saline and the medication montelukast during the experimental period. Group IV was given injections of AABS and montelukast as postoperative medication. Peri-implant capsules were excised after 8 weeks and were evaluated for transparency, inflammatory cell content, capsule thickness, collagen pattern and TGF-ß expression. RESULTS: The capsules in the experimental groups (i.e., groups II-IV) were significantly more transparent than those in group I (controls; p < 0.05, Student's t test). The mean capsule thickness of the experimental groups II (296 ± 14.76 µm), III (280 ± 14.77 µm) and IV (276 ± 39.28 µm) was smaller than that of the control group I (361 ± 35.43 µm). Compared to the control group, the histologic findings in the experimental groups suggested a decreased inflammatory response occurring in the peri-implant capsules as they exhibited minor vascularization and a reduced number of mast cells and macrophages. The collagen patterns in the experimental groups were of a lower density than in the control group with the former showing a loose, tidy collagen pattern. The amounts of TGF-ß and collagen I were higher in the control group than in the experimental groups. Group IV (the synergic effect group) had a more pronounced effect on all the parameters examined than that in groups II and III with separate drug administration. CONCLUSIONS: Montelukast and AABS reduced the thickness, the inflammatory cell infiltrate and the myofibroblast content of the peri-implant capsules around silicone implants in this white rat model. They lowered the expression of the fibrotic mediator, TGF-ß, and inhibited the peri-implant capsular fibrosis. Therefore, montelukast and AABS are effective in the reduction of silicone-induced peri-implant capsular formation.


Assuntos
Acetatos/farmacologia , Implantes de Mama/efeitos adversos , Complicações Pós-Operatórias/prevenção & controle , Quinolinas/farmacologia , Silicones/efeitos adversos , Animais , Colágeno/análise , Ciclopropanos , Imuno-Histoquímica , Ratos , Ratos Sprague-Dawley , Soluções , Sulfetos , Fator de Crescimento Transformador beta/análise
3.
Folia Morphol (Warsz) ; 72(2): 147-54, 2013 May.
Artigo em Inglês | MEDLINE | ID: mdl-23740503

RESUMO

Ligament of Henle is one of muscle-associated connective tissues of the rectus abdominis muscle, but it has been confused with the conjoint tendon (a common aponeurosis for insertion of the inferomedial end of the obliquus internus and transversus abdominis muscles). To reconsider the inguinal connective tissue structures, we examined 20 mid-term foetuses (10 males and 10 females) at approximately 14-20 weeks of gestation (crown rump length 100-170 mm). In female horizontal sections, we consistently found the ligament of Henle asa wing-like aponeurosis extending from the lateral margin of the rectus tendon behind the superficial inguinal ring. The ligament was separated from and located behind the conjoint tendon. In all male foetuses, instead of the ligament, the conjoint tendon was evident behind the superficial ring and it winded around the posterior aspect of the spermatic cord. Therefore, although a limited number of specimens were examined, the ligament of Henle was likely to be a female-specific structure. The ligament of Henle, if developed well, may provide an arch-like structure suitable for a name "falx inguinalis" instead of the inferomedial end ofthe conjoint tendon. In addition, a covering fascia of the iliopsoas muscle joined the posterior wall of the inguinal canal in male, but not in female, specimens.


Assuntos
Canal Inguinal/anatomia & histologia , Ligamentos/anatomia & histologia , Reto do Abdome/anatomia & histologia , Povo Asiático , Feminino , Feto , Humanos , Masculino
4.
Zhonghua Er Bi Yan Hou Tou Jing Wai Ke Za Zhi ; 58(10): 966-973, 2023 Oct 07.
Artigo em Zh | MEDLINE | ID: mdl-37840161

RESUMO

Objective: To evaluate the associations between the renalase single-nucleotide polymorphisms rs2576178 and rs10887800 and the risk of hypertension in OSA patients. Methods: A total of 3, 570 male OSA subjects diagnosed via standard polysomnography were included in this retrospective study. We recorded anthropometric, genomic, and polysomnographic parameters and blood pressure levels. All subjects were divided into four groups based on quartiles of the apnea-hypopnea index (AHI). The relationships between rs2576178 and rs10887800 and the risk of hypertension were evaluated using the binary logistic regression, and haplotype analysis. Results: In the bottom AHI quartile, rs10887800 was significantly associated with the risk of hypertension according to the dominant model [odds ratio(OR)=0.691, 95% confidence interval (CI)=0.483-0.990, P=0.044] even after adjustment for age, sex, and the body mass index. The G-A haplotype was associated with a co-effect of the two SNPs, namely, the risk of hypertension decreased (OR=0.879, 95%CI=0.784-0.986, P=0.028). Conclusions: We find no association between single rs2576178 or rs10887800 variants with the risk of hypertension in our OSA population. But, the synergistic effect of the two polymorphisms is associated with the risk of hypertension in OSA patients.


Assuntos
Hipertensão , Apneia Obstrutiva do Sono , Humanos , Masculino , Polimorfismo de Nucleotídeo Único , Estudos Retrospectivos , Hipertensão/complicações , Hipertensão/genética , Apneia Obstrutiva do Sono/genética , Apneia Obstrutiva do Sono/complicações , Fatores de Risco
6.
Eur Rev Med Pharmacol Sci ; 22(13): 4075-4079, 2018 07.
Artigo em Inglês | MEDLINE | ID: mdl-30024594

RESUMO

OBJECTIVE: To investigate the effect of nuclear factor-kappaB (NF-κB) on the myocardin-mediated differentiation of hysteromyoma cells. MATERIALS AND METHODS: Expression levels of myocardin in hysteromyoma cells from patients with hysteromyoma were detected. Normal uterine smooth muscle cells were used as control group. Overexpression of myocardin in hysteromyoma cells was achieved through lentivirus infection. Changes in expression levels of uterine smooth muscle cell maker p21, p57, Cyclin D1, PCNA, SM22α, and αSMA were detected. Hysteromyoma cells with lentivirus infection were stimulated by lipopolysaccharide (LPS), and changes in expression levels of myocardin were detected. RESULTS: Compared with normal uterine smooth muscle cells, the expression level of myocardin in hysteromyoma cells was extremely low, or even undetectable, and expression levels of smooth muscle cell differentiation markers were also minimal, and cells were in the de-differentiated state. Expression of exogenous myocardin can improve the expression of smooth muscle cell differentiation markers to induce cell re-differentiation. LPS stimulation can activate NF-κB to inhibit myocardin expression, thereby inducing cell dedifferentiation. CONCLUSIONS: NF-κB can inhibit the differentiation of hysteromyoma cells by decreasing the expression level of myocardin.


Assuntos
Mioma/patologia , NF-kappa B/metabolismo , Proteínas Nucleares/metabolismo , Transativadores/metabolismo , Neoplasias Uterinas/patologia , Diferenciação Celular/efeitos dos fármacos , Feminino , Humanos , Miócitos de Músculo Liso/metabolismo
7.
Aliment Pharmacol Ther ; 48(1): 44-54, 2018 07.
Artigo em Inglês | MEDLINE | ID: mdl-29797518

RESUMO

BACKGROUND: Hepatitis B virus (HBV) is the leading cause of hepatocellular carcinoma (HCC) worldwide. It remains incompletely understood in the real world how anti-viral therapy affects survival after HCC diagnosis. METHODS: This was an international multicentre cohort study of 2518 HBV-related HCC cases diagnosed between 2000 and 2015. Cox proportional hazards models were utilised to estimate hazard ratios (HR) with 95% (CI) for anti-viral therapy and cirrhosis on patients' risk of death. RESULTS: Approximately, 48% of patients received anti-viral therapy at any time, but only 17% were on therapy at HCC diagnosis (38% at US centres, 11% at Asian centres). Anti-viral therapy would have been indicated for >60% of the patients not on anti-viral therapy based on American criteria. Patients with cirrhosis had lower 5-year survival (34% vs 46%; P < 0.001) while patients receiving anti-viral therapy had increased 5-year survival compared to untreated patients (42% vs 25% with cirrhosis and 58% vs 36% without cirrhosis; P < 0.001 for both). Similar findings were seen for other patient subgroups by cancer stages and cancer treatment types. Anti-viral therapy was associated with a decrease in risk of death, whether started before or after HCC diagnosis (adjusted HR 0.62 and 0.79, respectively; P < 0.001). CONCLUSIONS: Anti-viral therapy improved overall survival in patients with HBV-related HCC across cancer stages and treatment types but was underutilised at both US and Asia centres. Expanded use of anti-viral therapy in HBV-related HCC and better linkage-to-care for HBV patients are needed.


Assuntos
Antivirais/uso terapêutico , Carcinoma Hepatocelular/tratamento farmacológico , Carcinoma Hepatocelular/mortalidade , Hepatite B/tratamento farmacológico , Hepatite B/mortalidade , Neoplasias Hepáticas/tratamento farmacológico , Neoplasias Hepáticas/mortalidade , Padrões de Prática Médica/estatística & dados numéricos , Idoso , Ásia/epidemiologia , Carcinoma Hepatocelular/virologia , Estudos de Coortes , Uso Indevido de Medicamentos/estatística & dados numéricos , Feminino , Mau Uso de Serviços de Saúde/estatística & dados numéricos , Hepatite B/complicações , Vírus da Hepatite B/fisiologia , Humanos , Prescrição Inadequada/estatística & dados numéricos , Cirrose Hepática/complicações , Cirrose Hepática/tratamento farmacológico , Cirrose Hepática/mortalidade , Cirrose Hepática/virologia , Neoplasias Hepáticas/virologia , Masculino , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Análise de Sobrevida , Estados Unidos/epidemiologia
9.
Transplant Proc ; 49(2): 303-308, 2017 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-28219589

RESUMO

BACKGROUND: The objective of the study was to establish a right-lobe graft weight (GW) estimation formula for living donor liver transplantation (LDLT) from right-lobe graft volume without veins (GVw/o_veins), including portal vein and hepatic vein measured by computed tomographic (CT) volumetry, and to compare its estimation accuracy with those of existing formulas. Right-lobe GW estimation formulas established with the use of graft volume with veins (GVw_veins) sacrifice accuracy because GW measured intra-operatively excludes the weight of blood in the veins. Right-lobe GW estimation formulas have been established with the use of right-lobe GVw/o_veins, but a more accurate formula must be developed. METHODS: The present study developed right-lobe GW estimation formulas based on GVw/o_veins as well as GVw_veins, using 40 cases of Korean donors: GW = 29.1 + 0.943 × GVw/o_veins (adjusted R2 = 0.94) and GW = 74.7 + 0.773 × GVw_veins (adjusted R2 = 0.87). The proposed GW estimation formulas were compared with existing GVw_veins- and GVw/o_veins-based models, using 43 cases additionally obtained from two medical centers for cross-validation. RESULTS: The GVw/o_veins-based formula developed in the present study was most preferred (absolute error = 21.5 ± 16.5 g and percentage of absolute error = 3.0 ± 2.3%). CONCLUSIONS: The GVw/o_veins-based formula is preferred to the GVw_veins-based formula in GW estimation. Accurate CT volumetry and alignment between planned and actual surgical cutting lines are crucial in the establishment of a better GW estimation formula.


Assuntos
Transplante de Fígado/métodos , Fígado/anatomia & histologia , Doadores Vivos , Adulto , Feminino , Veias Hepáticas/anatomia & histologia , Veias Hepáticas/diagnóstico por imagem , Humanos , Fígado/diagnóstico por imagem , Masculino , Tamanho do Órgão , Veia Porta/anatomia & histologia , Veia Porta/diagnóstico por imagem , Sensibilidade e Especificidade , Tomografia Computadorizada por Raios X/métodos , Tomografia Computadorizada por Raios X/normas , Sítio Doador de Transplante/anatomia & histologia , Sítio Doador de Transplante/diagnóstico por imagem , Transplantes/anatomia & histologia , Transplantes/diagnóstico por imagem , Adulto Jovem
10.
Zhonghua Xue Ye Xue Za Zhi ; 38(11): 951-955, 2017 Nov 14.
Artigo em Zh | MEDLINE | ID: mdl-29224318

RESUMO

Objective: To investigate the distribution and resistance of pathogens isolated from blood cultures in patients with hematological malignancies after chemotherapy in Union Hospital of Fujian Medical University so as to understand the real situation of blood stream infection (BSI) and provide the basis for rational use of antibiotics in clinic. Methods: The data of 657 strains isolated from blood culture specimens of patients with hematological malignancies from January 2013 to December 2016 were collected analyzed. Results: A total of 657 cases of blood culture positive bacterial strains were included in the study, involving 410 cases (62.4%) with single Gram-negative bacteria (G(-) bacteria) , 163 cases (24.8%) with single Gram-positive bacteria (G(+) bacteria) , 50 cases (7.6%) with single fungi. The most common 5 isolates in blood culture were Klebsiella pneumoniae (17.5%) , Escherichia coli (17.2%) , Coagulase negative staphylococci (CNS) (14.9%) , Pseudomonas aeruginosa (14.2%) and Staphylococcus aureus (3.5%) . The extended-spectrum beta-lactamase (ESBL) production rates of Klebsiella pneumoniae and Escherichia coli were 25.2% and 55.8%, respectively. ESBL producing strains were almost more resistant than non-ESBL producing strains. The resistance rates of Enterobacteriaceae to carbapenems, piperacillin/tazobactam and tigecycline were lower than 14.0%. The resistance rates of Pseudomonas aeruginosa to a variety of drugs were lower than 12.0%. Tigecycline-resistant Acinetobacter baumannii bacteria were not detected, and the resistance rates of Acinetobacter baumannii to cefixime and cefotaxime were 7.1%. Methicillin-resistant strains in CNS (MRCNS) and in Staphylococcus aureus (MRSA) accounted for 84.7% and 43.5%, respectively. Vancomycin, linezolid and tigecycline-resistant G(+) bacteria were not detected. Conclusion: The pathogens isolated from blood culture were widely distributed. Most of them were G(-) bacteria, and the resistance to antibiotics was quite common. Furhermore, vancomycin, linezolid and tigecycline can be chosen empirically to treat patiens who ar suspected to have G(+) bacterial BSI.


Assuntos
Bacteriemia/complicações , Farmacorresistência Bacteriana , Neoplasias Hematológicas/complicações , Antibacterianos , Resistência a Medicamentos , Humanos , Testes de Sensibilidade Microbiana
11.
Arch Gen Psychiatry ; 47(2): 135-40, 1990 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-2105705

RESUMO

Neuroendocrine testing was carried out in seven male volunteers before and at the end of a 10-day course of carbamazepine (up to 700 mg daily). After carbamazepine treatment, the prolactin response to intravenous administration of the serotonin precursor tryptophan (5 g) was significantly enhanced, but there was no change in basal plasma tryptophan level or in tryptophan disposition after infusion. The prolactin response to intravenous protirelin (6.25 micrograms) was unaltered. Carbamazepine treatment also produced an increase in the growth hormone response to subcutaneous administration of the dopamine agonist apomorphine hydrochloride (5 micrograms/kg). These data suggest that carbamazepine may alter brain serotonin and dopamine function in humans. Such effects could be involved in the therapeutic properties of carbamazepine in affective disorder.


Assuntos
Carbamazepina/farmacologia , Prolactina/sangue , Hormônio Liberador de Tireotropina/farmacologia , Adulto , Apomorfina/farmacologia , Encéfalo/efeitos dos fármacos , Encéfalo/metabolismo , Carbamazepina/uso terapêutico , Transtorno Depressivo/tratamento farmacológico , Transtorno Depressivo/metabolismo , Dopamina/metabolismo , Hormônio do Crescimento/sangue , Humanos , Masculino , Serotonina/metabolismo , Triptofano/sangue , Triptofano/farmacologia
12.
J Med Chem ; 43(8): 1635-40, 2000 Apr 20.
Artigo em Inglês | MEDLINE | ID: mdl-10780920

RESUMO

In search of water-soluble artemisinin derivatives that are more stable than sodium artesunate, over 30 derivatives containing an amino group (compounds 3-5) were synthesized and tested in mice. All products tested (except 5a and 5b) are the beta isomers. These basic compounds combined with organic acids (oxalic acid, maleic acid, etc. ) to yield the corresponding salts. Generally, the maleates have better solubility in water than the corresponding oxalates. The aqueous solutions of these salts can be kept at room temperature for several weeks without any discernible decomposition. Compounds 3f, 3h, and 3r are much more active against P. berghei than artesunic acid by oral administration and therefore were further tested in monkeys. However, their oral efficacies are poorer than that of artesunic acid against P. knowlesi in rhesus monkeys. It is interesting to note that 3f, 3h, and 3r showed much lower efficacies against P. berghei when they were administered subcutaneously than orally.


Assuntos
Antimaláricos/síntese química , Artemisininas , Compostos Heterocíclicos de 4 ou mais Anéis/síntese química , Sesquiterpenos/química , Administração Oral , Animais , Antimaláricos/administração & dosagem , Antimaláricos/química , Antimaláricos/farmacologia , Compostos Heterocíclicos de 4 ou mais Anéis/administração & dosagem , Compostos Heterocíclicos de 4 ou mais Anéis/química , Compostos Heterocíclicos de 4 ou mais Anéis/farmacologia , Injeções Subcutâneas , Malária/tratamento farmacológico , Camundongos , Plasmodium berghei , Relação Estrutura-Atividade
13.
Neurosci Lett ; 295(1-2): 41-4, 2000 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-11078932

RESUMO

There is now overwhelming evidence that the varepsilon4 allele of apolipoprotein (APOE) gene is a major risk factor for late-onset Alzheimer's disease (AD). However, the APOE locus only accounts for a proportion of the overall genetic risk for AD. The angiotensin-converting enzyme (ACE) is widely expressed in the brain and may have a role in AD. Recently an insertion/deletion (I/D) DNA polymorphism at the intron 16 of ACE gene has been found associated with late-onset AD, but the results are not consistent. We have examined ACE gene in a cohort of Han Chinese AD cases and controls. We have found the ACE-I allele was enriched in our cases compared to controls (odds ratio (OR)=2.09, P=0.0043). The phenomenon was restricted to cases presenting with AD after the age of 70 years (P<0.0005), and was independent of APOE genotype. We conclude that ACE genotype is a risk factor for late onset AD.


Assuntos
Alelos , Doença de Alzheimer/genética , Peptidil Dipeptidase A/genética , Polimorfismo Genético/genética , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Estudos de Casos e Controles , China/etnologia , Feminino , Genótipo , Humanos , Masculino , Pessoa de Meia-Idade , Razão de Chances
14.
Neurosci Lett ; 350(1): 25-8, 2003 Oct 16.
Artigo em Inglês | MEDLINE | ID: mdl-12962909

RESUMO

Polymorphisms at positions -491, -427 and -219 in the promoter region of the Apolipoprotein E APOE gene have been variously reported to confer an increased risk of developing Alzheimer's disease (AD) independent of the effect of epsilon 2, 3 or 4 alleles in exon 4. In order to assess APOE promoter polymorphisms as independent risk factors in AD we have compared results in 183 definite or probable AD cases with 133 controls. We assayed markers at sites -491, -427, -219, and +113 in APOE gene and a polymorphic Hha1 site in the nearby APOC1 gene. We found that APOE promoter polymorphisms and APOC1 insertion alleles were significantly associated with AD. However, after stratification for epsilon 4 allele, only the A allele at -491 in APOE remained significantly associated with AD. The effects of the other markers depended almost entirely upon linkage disequilibrium with epsilon 4 allele, and only trends remained when cases and controls were stratified for the presence or absence of epsilon 4 allele. This occurred irrespective of whether markers were examined separately or together as haplotypes. So in the Chinese population only APOE -491 promoter alleles confer significant risk of AD independent of epsilon 4 status.


Assuntos
Doença de Alzheimer/genética , Apolipoproteínas E/genética , Polimorfismo Genético , Regiões Promotoras Genéticas , Idoso , Alanina/genética , Alelos , Doença de Alzheimer/epidemiologia , Apolipoproteínas E/classificação , Povo Asiático , Estudos de Casos e Controles , Distribuição de Qui-Quadrado , Estudos de Coortes , Análise Mutacional de DNA , Manual Diagnóstico e Estatístico de Transtornos Mentais , Éxons , Feminino , Frequência do Gene , Ligação Genética , Genótipo , Humanos , Desequilíbrio de Ligação , Masculino , Reação em Cadeia da Polimerase/métodos , Fatores de Risco , Treonina/genética
15.
J Biotechnol ; 33(2): 107-22, 1994 Mar 31.
Artigo em Inglês | MEDLINE | ID: mdl-7764727

RESUMO

A modeling framework is proposed to assess the detrimental effects of air sparging and other bubble phenomena (vortex entrainment, coalescence, bursting) on freely suspended cells in an aerated, agitated bioreactor. It is assumed that cells may be rendered nonviable by bubble breakup/coalescence within the medium, by bubble formation at the sparger, or by bubble bursting at the free surface. Some plausible mechanisms are argued from the energetic view point. The dominant parameters in each case are the cell-bubble encounter rate and the bubble breakup/bursting rate. These inactivation processes lead to a Michaelis-Menten expression for the specific cell death rate, which is shown to be linearly proportional to the specific bubble interfacial area (total bubble surface area per unit volume of media). By using published viable cell concentration data for retarded growth of mammalian cells due to sparging, the interfacial area correlation is demonstrated. The method is generalized to aerated bioreactor conditions. The article offers a unique, consistent perspective on how cell death can be viewed.


Assuntos
Morte Celular , Modelos Biológicos , Ar , Animais , Células Cultivadas , Meios de Cultura , Humanos
16.
Biotechnol Prog ; 8(3): 244-51, 1992.
Artigo em Inglês | MEDLINE | ID: mdl-1368260

RESUMO

Bioreactor headspace pressurization represents an excellent means of enhancing oxygen mass transfer to a culture. This method is particularly effective in situations where stirring or vigorous aeration is difficult. Because it in itself introduces no undesirable hydrodynamic force, the proposed method is also attractive for cells susceptible to agitation and sparging. Experiments were first conducted in an ideal fermentor by sparging air into a sulfite solution free from extraneous microbial effects. An increased oxygen mass transfer rate resulting from pressurization led to a superior cell growth rate and a higher maximum cell density in both of the microbial systems studied: a bacterial (Escherichia coli) culture up to 2.72 bar and a fragile algal (Ochromonas malhamensis) culture with pressure programming. Applying pressurization increased the maximum dry cell weight from 1.47 g/L to 1.77 g/L in the E. coli culture and increased the maximum viable cell density from 4 x 10(7) cells/mL to 10(8) cells/mL in the algal culture. An additional advantage is that formation of undesirable products under oxygen limitation, e.g., acetic acid in the E. coli culture, can be suppressed. A significant (over 250%) improvement in the oxygen transfer rate can be achieved with existing fermentors with little modification as they are already designed to withstand reasonable pressure from autoclaving. This method is simple, clean, inexpensive, and easily implemented, and it can be applied alongside other existing methods of oxygen mass transfer enhancement.


Assuntos
Biotecnologia/métodos , Fermentação , Oxigênio/metabolismo , Ciclo Celular , Divisão Celular/fisiologia , Escherichia coli/citologia , Eucariotos/citologia , Oxigênio/química , Pressão
17.
Chin Med J (Engl) ; 104(10): 851-7, 1991 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-1752144

RESUMO

In 30 patients with intractable generalized epilepsy treated with cerebral commissurotomy, the corpus callosum was stimulated intraoperatively at a 1 cm interval with electric current, and evoked potentials (EPs) were recorded from different areas of the brain for determining the distribution patterns of functional projections from the corpus callosum to the cerebral cortex. The surface of the corpus callosum in man was 12 cm long and it was divided into 12 segments (1 cm each). Stimulation of the first segment resulted in EPs only in the frontal lobe. Stimulation of segments 2-4 produced EPs mainly in the anterior, middle and posterior frontal lobe, anterior and central temporal lobe, rarely in parietal and occipital lobes. Stimulation of segments 5-8 induced EPs mainly in the frontal and temporal lobes, but rarely in the parietal and occipital regions; on stimulation of segments 9-11, EPs occurred only in the parietal and occipital regions. These results were confirmed electrophysiologically in 5 cats and anatomically in 8 cats. These data provide an anatomical basis for selective cerebral commissurotomy in the treatment of intractable epilepsy. Hence in patients with a concentration of epileptic discharges in the frontal lobe, the 4 anterior segments of the corpus callosum should be incised. Epileptic discharges in the frontotemporal region indicates that the middle segments should be incised and epileptic activities originating from the parieto-occipital regions can be treated effectively by selective section of the posterior corpus callosum (segments 9-12).


Assuntos
Córtex Cerebral/fisiopatologia , Corpo Caloso/fisiopatologia , Epilepsia/fisiopatologia , Adolescente , Adulto , Animais , Gatos , Córtex Cerebral/anatomia & histologia , Criança , Corpo Caloso/anatomia & histologia , Corpo Caloso/cirurgia , Estimulação Elétrica , Epilepsia/cirurgia , Potenciais Evocados , Feminino , Humanos , Masculino
18.
Appl Biochem Biotechnol ; 42(1): 53-66, 1993 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-8215348

RESUMO

An in situ optical probe was developed to measure reliably the local specific interfacial area of the suspended phase (specifically air bubbles) in a bioreactor. The light transmission-based probe can be simply and inexpensively constructed from readily available components. The probe's performance was tested in a suspension of opaque monodisperse polystyrene spheres as well as in the presence of nonspherical, nonuniformly distributed bubbles. The probe signal is directly related to the local specific interfacial area by a calibration equation obtained with polystyrene beads, as opposed to the cumbersome direct photographic bubble measurements that the probe attempts to replace. Its utility was demonstrated by measuring the specific bubble interfacial area at two locations in a bioreactor at various agitation intensities.


Assuntos
Biotecnologia/instrumentação , Fermentação , Biotecnologia/métodos , Calibragem , Luz , Matemática , Microesferas , Poliestirenos/química
19.
Yao Xue Xue Bao ; 32(11): 874-8, 1997 Nov.
Artigo em Zh | MEDLINE | ID: mdl-11596209

RESUMO

For the purpose of improving the oral antimalarial activities of the fluorenemethanols (reported by us in previous articles) which were less effective by oral than by subcutaneous administration, 24 alpha-(alkylaminomethyl)-2, 7-dichloro-9-substituted benzylidene-4-fluorenemethanols (III) were synthesized. The results of preliminary screenings demonstrated that five compounds (No. 1-4, 8) exhibited significant antimalarial activities against Plasmodium berghei NK65 strain in mice by oral administration, at dose of 6.25 mg.kg-1.d-1 x 3 with suppressive rate of 100%. Further evaluation of these 5 compounds showed that 4 of them (No. 1-4) were superior to chloroquine in parallel tests, their ED50 and ED90 were 1.0, 1.6; 0.6, 0.9; 0.7, 1.5 and 0.8, 1.6 mg.kg-1.d-1 x 3 respectively, while the ED50 and ED90 of chloroquine were 1.9 and 2.9 mg.kg-1. d-1 x 3 respectively; one compound (No 8) was equal to chloroquine, its ED50 and ED90 were 1.5 and 3.2 mg.kg-1.d-1 x 3 respectively. Further assessment of these 4 compounds are in progress.


Assuntos
Antimaláricos/síntese química , Fluorenos/síntese química , Fluorenos/uso terapêutico , Malária/tratamento farmacológico , Metanol/análogos & derivados , Metanol/síntese química , Metanol/uso terapêutico , Plasmodium berghei , Animais , Antimaláricos/química , Antimaláricos/uso terapêutico , Fluorenos/química , Metanol/química , Camundongos , Estrutura Molecular
20.
Yao Xue Xue Bao ; 29(4): 268-75, 1994.
Artigo em Zh | MEDLINE | ID: mdl-7976342

RESUMO

On basis of our previous work, seven 4-methyl-5-substituted phenoxy-6-methoxy-8-(1-methyl-4-amino-butylamino)-quinolines (II2-8) were synthesized and their antimalarial activities were preliminarily evaluated. The target compounds were prepared from 2-nitro-4-methoxy-5-bromo-acetanilide as previously described. The structures of II2-8 and all of the unknown intermediates were confirmed by elementary and spectral analyses. Preliminary biological evaluation revealed that all of II2-8 exhibited significant blood schizonticidal activity and were 4-8 times as effective as primaquine in causal prophylactic test in mice.


Assuntos
Antimaláricos/síntese química , Primaquina/síntese química , Animais , Antimaláricos/uso terapêutico , Malária/tratamento farmacológico , Camundongos , Plasmodium berghei , Primaquina/uso terapêutico
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA