RESUMO
OBJECTIVES: Violent behavior is influenced by individual and societal characteristics, but the role of environmental factors is less understood. Our aims were to use national-level data to identify the association between criminal behavior and short-term temperature conditions, including the departure of daily temperatures from normal conditions. METHODS: We conducted a multi-stage hierarchical time-series model across 436 U.S. counties and 14-years representing 100.4 million people to investigate the association between daily mean temperature and daily mean temperatures departing from normal conditions with violent and non-violent crime counts. First-stage comparisons were made within counties to control for population and geographic heterogeneities, while a second stage combined estimates. We evaluated differences in risk based on county sociodemographic characteristics and estimated non-linear exposure-response relationships. RESULTS: We observed a total of 9.0 million violent crimes and 20.9 million non-violent property crimes between 2000 through 2013. We estimated that each 10 °C increase in daily temperature or daily departure from long-term normal temperatures were associated with 11.92% (95% PI: 11.57, 12.27) and 10.37% (95% PI: 10.05, 10.69) increase in the risk of violent crime, respectively. Similar, but lower in magnitude trends, were observed for property crime risks. We found that crime risk plateaus and decreases at high daily temperatures, but for temperatures departing from normal, the association with crime increased linearly. Seasonal variations showed that anomalously warm temperatures days during cool months had the greatest risk. CONCLUSIONS: Our study revealed an association between higher temperatures and high departure from normal temperatures with both violent and non-violent crime risk, regardless of community-type. However, our findings on seasonal and daily trends suggest that daily mean temperature may impact crime by affecting routine activities and behavior, as opposed to a temperature-aggression relationship. These results may advance public response and planning to prevent violent behavior.
Assuntos
Agressão , Violência , Crime , Humanos , Estações do Ano , TemperaturaRESUMO
Sampling campaign design is a crucial aspect of air pollution exposure studies. Selection of both monitor numbers and locations is important for maximizing measured information, while minimizing bias and costs. We developed a two-stage geostatistical-based method using pilot NO2 samples from Lanzhou, China with the goal of improving sample design decision-making, including monitor numbers and spatial pattern. In the first step, we evaluate how additional monitors change prediction precision through minimized kriging variance. This was assessed in a Monte Carlo fashion by adding up to 50 new monitors to our existing sites with assigned concentrations based on conditionally simulated NO2 surfaces. After identifying a number of additional sample sites, a second step evaluates their potential placement using a similar Monte Carlo scheme. Evaluations are based on prediction precision and accuracy. Costs are also considered in the analysis. It was determined that adding 28-locations to the existing Lanzhou NO2 sampling campaign captured 73.5% of the total kriged variance improvement and resulted in predictions that were on average within 10.9 µg/m3 of measured values, while using 56% of the potential budget. Additional monitor sites improved kriging variance in a nonlinear fashion. This method development allows for informed sampling design by quantifying prediction improvement (accuracy and precision) against the costs of monitor deployment.
Assuntos
Poluentes Atmosféricos/análise , Poluição do Ar/análise , Monitoramento Ambiental/métodos , Material Particulado/análise , China , Seguimentos , Substâncias Perigosas/análise , Humanos , Método de Monte Carlo , Análise EspacialRESUMO
School facility conditions, environment, and perceptions of safety and learning have been investigated for their impact on child development. However, it is important to consider how the environment separately influences academic performance and attendance after controlling for school and community factors. Using results from the Maryland School Assessment, we considered outcomes of school-level proficiency in reading and math plus attendance and chronic absences, defined as missing 20 or more days, for grades 3-5 and 6-8 at 158 urban schools. Characteristics of the environment included school facility conditions, density of nearby roads, and an index industrial air pollution. Perceptions of school safety, learning, and institutional environment were acquired from a School Climate Survey. Also considered were neighborhood factors at the community statistical area, including demographics, crime, and poverty based on school location. Poisson regression adjusted for over-dispersion was used to model academic achievement and multiple linear models were used for attendance. Each 10-unit change in facility condition index, denoting worse quality buildings, was associated with a decrease in reading (1.0% (95% CI: 0.1-1.9%) and math scores (0.21% (95% CI: 0.20-0.40), while chronic absences increased by 0.75% (95% CI: 0.30-1.39). Each log increase the EPA's Risk Screening Environmental Indicator (RSEI) value for industrial hazards, resulted in a marginally significant trend of increasing absenteeism (pâ¯<â¯0.06), but no association was observed with academic achievement. All results were robust to school-level measures of racial composition, free and reduced meals eligibility, and community poverty and crime. These findings provide empirical evidence for the importance of the community and school environment, including building conditions and neighborhood toxic substance risk, on academic achievement and attendance.
Assuntos
Absenteísmo , Desempenho Acadêmico , Meio Ambiente , Instituições Acadêmicas , Criança , Cidades , Crime , Humanos , Maryland , PobrezaRESUMO
The leishmaniases consist of visceral and cutaneous syndromes present in > 30 endemic regions of the world. Miltefosine (hexadecylephosphocholine) is the first oral agent that is effective and tolerated for both visceral and cutaneous disease in several endemic regions, and represents a major advance in the treatment of these diseases.
Assuntos
Antiprotozoários/uso terapêutico , Leishmaniose/tratamento farmacológico , Fosforilcolina/análogos & derivados , Adulto , Antiprotozoários/química , Antiprotozoários/farmacologia , Criança , Ensaios Clínicos como Assunto , Desenho de Fármacos , Infecções por HIV/complicações , Humanos , Leishmaniose/complicações , Fosforilcolina/química , Fosforilcolina/farmacologia , Fosforilcolina/uso terapêuticoRESUMO
The oral agent miltefosine has demonstrated a >95% cure rate in Indian visceral leishmaniasis. We performed a large, placebo-controlled study of miltefosine therapy (2.5 mg/kg per day orally for 28 days) against cutaneous leishmaniasis in Colombia and Guatemala. In regions in Colombia where Leishmania vianna panamensis is common, the per-protocol cure rates for miltefosine and placebo were 91% (40 of 44 patients) and 38% (9 of 24). These values are similar to historic values for the antimony standard of care and placebo. In regions in Guatemala where L. v. braziliensis and L. mexicana mexicana are common, the per-protocol cure rates were 53% (20 of 38) for miltefosine and 21% (4 of 19) for placebo. The miltefosine rate was lower than historic antimony cure rates of >90%. Miltefosine was well tolerated. Miltefosine is a useful oral agent against cutaneous leishmaniasis due to L. v. panamensis in Colombia but not against leishmaniasis due to L. v. braziliensis in Guatemala.
Assuntos
Antiprotozoários/uso terapêutico , Leishmaniose Cutânea/tratamento farmacológico , Cooperação do Paciente , Fosforilcolina/análogos & derivados , Fosforilcolina/uso terapêutico , Administração Oral , Adulto , Animais , Antiprotozoários/efeitos adversos , Colômbia , Método Duplo-Cego , Tolerância a Medicamentos , Feminino , Guatemala , Humanos , Leishmania/efeitos dos fármacos , Masculino , Fosforilcolina/efeitos adversos , Resultado do TratamentoRESUMO
Firm diagnosis of visceral leishmaniasis (kala-azar) requires organ aspiration and microscopic examination of tissue specimens. To determine the usefulness of noninvasive diagnosis by strip test detection of anti-K39 immunoglobulin (Ig) G antibody in blood specimens obtained by fingerstick, 143 Indian patients with suspected kala-azar (fever, splenomegaly, anemia) were studied. Of 120 strip test-positive subjects (subjects with presumed kala-azar [group A]), amphotericin B treatment induced clinical cure in 119. Of 23 strip test-negative subjects (subjects presumed to have other diseases [group B]), 16 had other disorders diagnosed at entry, 4 responded to empiric antimalarial therapy, 2 were proven to have kala-azar, and 1 died elsewhere after undergoing splenic aspiration. Six months after treatment ended, all 120 patients in group A and the 18 assessable patients in group B were healthy. In a region in India where visceral infection is prevalent, strip test detection of anti-K39 IgG is a clinically promising diagnostic guide in persons with suspected kala-azar.
Assuntos
Antígenos de Protozoários , Leishmaniose Visceral/diagnóstico , Proteínas de Protozoários/análise , Adolescente , Adulto , Anticorpos/análise , Biomarcadores/análise , Técnicas e Procedimentos Diagnósticos , Feminino , Seguimentos , Humanos , Índia/epidemiologia , Leishmaniose Visceral/tratamento farmacológico , Leishmaniose Visceral/imunologia , Masculino , Pesquisa , Resultado do TratamentoRESUMO
Plasmodia infect the liver for about 7 days before subsequently infecting the blood. Present prophylaxis against Plasmodium falciparum malaria employs agents that primarily kill blood stages and must be continued for 28 days after the last exposure. Atovaquone-proguanil (Malarone) is a new antimalarial agent that is licensed in 35 countries as treatment against blood-stage infection, but its components (atovaquone and proguanil) have separately been shown to be active also against liver stages. To determine whether atovaquone-proguanil is sufficiently active against liver stages to be discontinued 7 days after exposure, we challenged 16 volunteers with P. falciparum via infected mosquitoes. Twelve volunteers received atovaquone-proguanil (1 tablet daily) on the day prior to challenge, on the day of challenge, and for the next 6 days; 4 volunteers received matching placebo. All placebo volunteers demonstrated parasitaemia and malarial symptoms beginning on days 11-12 after challenge. No atovaquone-proguanil volunteer acquired malaria. Atovaquone-proguanil is the first licensed antimalarial agent that kills P. falciparum in the liver and that may be discontinued 7 days after the last exposure.
Assuntos
Antimaláricos/uso terapêutico , Hepatopatias Parasitárias/tratamento farmacológico , Malária Falciparum/prevenção & controle , Naftoquinonas/uso terapêutico , Proguanil/uso terapêutico , Adolescente , Adulto , Atovaquona , Método Duplo-Cego , Combinação de Medicamentos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Naftoquinonas/farmacocinética , Proguanil/farmacocinética , Resultado do TratamentoRESUMO
Cutaneous leishmaniasis is presently treated with 20 days of parenteral therapy with a frequently toxic drug (antimony). Topical formulations of paromomycin (15%) plus methylbenzethonium chloride (MBCL, 12%) or plus urea (10%) in soft white paraffin have been tested for Old and New World disease in humans. We compared the efficacy of a new topical formulation, WR 279,396 (paromomycin [15%] plus gentamicin [0.5%]) to the clinical formulations in the treatment of cutaneous disease in BALB/c mice. Sixty-day-old lesions were treated twice a day for 10 days, and the response to therapy was determined over a further 70 days. For ulcers due to Leishmania major or to Leishmania mexicana, 100% of lesions in the WR 279,396 group healed by day 20 after therapy and did not relapse by day 70; 83% of lesions healed without relapse in the paromomycin-MBCL group. In the paromomycin-urea group, 100% of L. major lesions healed by day 30 but 30% relapsed. For ulcers due to Leishmania panamensis or Leishmania amazonensis, all lesions treated with WR 279,396 healed and did not relapse; < 50% of lesions treated with paromomycin-MBCL healed by day 30, and all lesions relapsed by day 70. In addition to being active, WR 279,396 was not toxic in this model and appears to have a cosmetic effect (promoting hair growth, healing, and limiting the size of the scar).
Assuntos
Antiprotozoários/uso terapêutico , Quimioterapia Combinada/uso terapêutico , Gentamicinas/uso terapêutico , Leishmania/efeitos dos fármacos , Leishmaniose Cutânea/tratamento farmacológico , Paromomicina/uso terapêutico , Administração Tópica , Animais , Benzetônio/análogos & derivados , Benzetônio/uso terapêutico , Cricetinae , Quimioterapia Combinada/administração & dosagem , Gentamicinas/administração & dosagem , Camundongos , Camundongos Endogâmicos BALB C , Paromomicina/administração & dosagem , Resultado do Tratamento , Ureia/uso terapêuticoAssuntos
Anfotericina B/uso terapêutico , Antiprotozoários/uso terapêutico , Aprovação de Drogas , Leishmaniose Visceral/tratamento farmacológico , Anfotericina B/administração & dosagem , Antiprotozoários/administração & dosagem , Ensaios Clínicos como Assunto , Portadores de Fármacos , Humanos , Lipossomos , Estados Unidos , United States Food and Drug AdministrationRESUMO
Mucosal leishmaniasis is arguably the most morbid sequelae of cutaneous leishmaniasis. The importance of early diagnosis for effective therapy, coupled with the difficulty of diagnosing the disease parasitologically, prompted this investigation of humoral immune markers of mucosal disease. Promastigote soluble antigens of Leishmania braziliensis, isolated from cutaneous and mucosal lesions, were separated by sodium dodecyl sulfate polyacrylamide gel electrophoresis; antigens were identified by immunoblotting with parasite-specific IgG antibody-positive sera of patients with mucosal disease (n = 18) and cutaneous disease (n = 23). For antigens of the cutaneous parasite WR 2095, mucosal sera generally reacted intensely to antigens of 75, 66, and 45 kDa and weakly to 48-50-kDa antigens, whereas cutaneous sera generally detected weakly the first 3 antigens and intensely the latter doublet. The data suggest that the transition from the cutaneous antigenic profile to a mucosal antigenic profile could be used to predict mucosal disease in approximately half of mucosal patients. An additional finding was that antibodies present in the sera of patients with mucosal disease labeled a 66-kDa peptide of normal human lip mucosa more intensely than did cutaneous sera. Autoimmune processes stimulated by the reaction of IgG, originally directed against the 66-kDa of L. braziliensis, to the 66-kDa antigen of mucosal tissue may contribute to the clinical presentation of mucosal leishmaniasis.
Assuntos
Anticorpos Antiprotozoários/biossíntese , Leishmania braziliensis/imunologia , Leishmaniose Cutânea/imunologia , Leishmaniose Mucocutânea/imunologia , Adolescente , Adulto , Idoso , Animais , Antígenos de Protozoários/imunologia , Western Blotting , Reações Cruzadas , Eletroforese em Gel de Poliacrilamida , Ensaio de Imunoadsorção Enzimática , Feminino , Técnica Indireta de Fluorescência para Anticorpo , Interações Hospedeiro-Parasita , Humanos , Imunoglobulina G/análise , Masculino , Pessoa de Meia-IdadeRESUMO
In India, sodium antimony gluconate is the drug of choice for kala-azar. Due to increasing unresponsiveness to this drug in the current epidemic that began in the early 1970s, daily doses of 20 mg/kg/day for 30 days or more is recommended as opposed to the 10 mg/kg/day dose for 6-10 days used in the past. Of the 130-150 patients treated annually at our center with locally made sodium antimony gluconate, serious cardiotoxicity has occurred in less than 10%. During April 1995 at the University Hospital in Varanasi, we encountered life-threatening cardiotoxicity after 3-28 days of therapy in each of the eight patients being treated with a new lot of this drug made by a different manufacturer. Of the eight patients, six each developed congestive heart failure and/or prolongation of the corrected QT interval (QTc), and three died as a direct consequence of drug-induced toxicities. In three instances, the life-threatening complications occurred with a cumulative dose of less than 300 mg/kg. In patients with prolonged QTc, ventricular premature beats and ventricular tachycardia were recorded; in one patient, the ventricular tachycardia progressed to torsade de pointes, culminating in ventricular fibrillation and death. Since switching to different lots of this drug, we have not seen further clustering of dangerous cardiotoxicity. The antimony content of the implicated drug was comparable with that in lots from other manufacturers that did not show overt toxicity, but the osmolarity was approximately 300 mOsm/L higher. The simple technique of measuring of osmolarity may help identify inappropriately manufactured drug.
Assuntos
Gluconato de Antimônio e Sódio/efeitos adversos , Antiprotozoários/efeitos adversos , Cardiopatias/induzido quimicamente , Coração/efeitos dos fármacos , Leishmaniose Visceral/tratamento farmacológico , Adulto , Antimônio/análise , Gluconato de Antimônio e Sódio/química , Gluconato de Antimônio e Sódio/uso terapêutico , Antiprotozoários/química , Antiprotozoários/uso terapêutico , Eletrocardiografia , Evolução Fatal , Feminino , Cardiopatias/fisiopatologia , Humanos , Masculino , Pessoa de Meia-Idade , Concentração OsmolarRESUMO
Reported are the results of a study to determine the efficacy and safety of liposomal amphotericin B (AmBisome) for treating visceral leishmaniasis (kala-azar) in several developing countries where the disease is endemic (Brazil, India, and Kenya). At each study site, sequential cohorts of 10 patients each were treated with AmBisome at a dose of 2 mg.kg-1.day-1 (2 MKD). The first cohort received regimen 1:2 MKD on days 1-6 and day 10 (total dose: 14 mg/kg). If the efficacy with this regimen was satisfactory, a second cohort received regimen 2:2 MKD on days 1-4 and 10 (total dose: 10 mg/kg); and a third cohort received regimen 3:2 MKD on days 1, 5, and 10 (total dose: 6 mg/kg). In India, regimens 1, 2, and 3 (which were studied concurrently) each cured 100% of 10 patients. In Kenya, regimen 1 cured all 10 patients, regimen 2 cured 90% of 10 patients, but regimen 3 cured only 20% of 5 patients. In Brazil, regimen 1 was only partially curative: 5 of 13 patients (62%). Therefore, 15 patients were administered regimen 4 (2 MKD for 10 consecutive days; total dose, 20 mg/kg) and 13 patients were cured (83%). These results suggest that for the treatment of kala-azar the following doses of AmBisome should be administered: in India and Kenya, 2 mg/kg on days 1-4 and day 10; and in Brazil, 2 mg/kg on days 1-10.
PIP: The efficacy and safety of liposomal amphotericin B (AmBisome) for the treatment of visceral leishmaniasis (kala-azar) were evaluated in a phase II clinical trial conducted in Brazil, India, and Kenya--countries where kala-azar is endemic. At each study site, sequential cohorts of 10 patients each received three different dosage regimens of AmBisome. The first cohort received 2 mg/kg/day (MKD) on days 1-6 and day 10 (total dose, 14 mg/kg). If the efficacy of this regimen was satisfactory, the second cohort received 2 MKD on days 1-4 and day 10 (total dose, 10 mg/kg) and a third cohort was administered 2 MKD on days 1, 5, and 10 (total dose, 6 mg/kg). In India, all three regimens (studied concurrently) cured 100% of the total of 30 patients. In Kenya, the first regimen cured all 10 patients (100%), the second cured 9 of 10 patients (90%), and the third cured only 1 of 5 patients (20%). In Brazil, since the first regimen cured only 5 of 13 patients (62%), the next 15 patients were given 2 MKD for 10 consecutive days (total dose, 20 mg/kg); this intensified regimen cured 13 of the 15 patients (83%). Adverse effects were minor, primarily fever and chills associated with infusion and irregular pulse. These findings suggest that leishmaniasis patients in India and Kenya should receive 2 mg/kg of AmBisome on days 1-4 and day 10, while those in Brazil should be given 2 mg/kg on days 1-10. AmBisome treatment is especially recommended for those for whom standard agents are likely to be ineffective, toxic, or difficult to administer.
Assuntos
Anfotericina B/uso terapêutico , Antiprotozoários/uso terapêutico , Países em Desenvolvimento , Doenças Endêmicas , Leishmaniose Visceral/tratamento farmacológico , Adolescente , Adulto , Brasil , Criança , Relação Dose-Resposta a Droga , Esquema de Medicação , Humanos , Índia , Quênia , Leishmaniose Visceral/epidemiologia , Resultado do TratamentoRESUMO
We conducted a randomized, double-blind, placebo-controlled multicenter trial of azithromycin (1,200 mg once weekly) for the prevention of Mycobacterium avium complex (MAC) infection in patients with AIDS and a CD4 cell count of < 100/mm3. In an intent-to-treat analysis through the end of therapy plus 30 days, nine (10.6%) of 85 azithromycin recipients and 22 (24.7%) of 89 placebo recipients developed MAC infection (hazard ratio, 0.34; P = .004). There was no difference in the ranges of minimal inhibitory concentrations of either clarithromycin or azithromycin for the five breakthrough (first) MAC isolates from the azithromycin group and the 18 breakthrough MAC isolates from the placebo group. Of the 76 patients who died during the study, four (10.5%) of 38 azithromycin recipients and 12 (31.6%) of 38 placebo recipients had a MAC infection followed by death (P = .025). For deaths due to all causes, there was no difference in time to death or number of deaths between the two groups. Episodes of non-MAC bacterial infection per 100 patient years occurred in 43 azithromycin recipients and 88 placebo recipients (relative risk, 0.49; 95% confidence interval, 0.33-0.73). The most common toxic effect noted during the study was gastrointestinal, reported by 78.9% of azithromycin recipients and 27.5% of placebo recipients. Azithromycin given once weekly is safe and effective in preventing disseminated MAC infection, death due to MAC infection, and respiratory tract infections in patients with AIDS and CD4 cell counts of < 100/mm3.
Assuntos
Infecções Oportunistas Relacionadas com a AIDS/prevenção & controle , Antibacterianos/uso terapêutico , Azitromicina/uso terapêutico , Infecção por Mycobacterium avium-intracellulare/prevenção & controle , Infecções Oportunistas Relacionadas com a AIDS/epidemiologia , Infecções Oportunistas Relacionadas com a AIDS/microbiologia , Adolescente , Adulto , Antibacterianos/administração & dosagem , Antibacterianos/efeitos adversos , Azitromicina/administração & dosagem , Azitromicina/efeitos adversos , Método Duplo-Cego , Esquema de Medicação , Feminino , Seguimentos , Humanos , Masculino , Testes de Sensibilidade Microbiana , Pessoa de Meia-Idade , Infecção por Mycobacterium avium-intracellulare/epidemiologia , Infecção por Mycobacterium avium-intracellulare/microbiologia , SobreviventesRESUMO
Azithromycin prevents malaria in animal models and early clinical trials. We determined the prophylactic efficacy of three antibiotic regimens given for 10 weeks (azithromycin, 250 mg daily; azithromycin, 1,000 mg weekly; and doxycycline, 100 mg daily) relative to that of placebo for 232 adult volunteers residing in an area of intense malaria transmission. Any confirmed parasitemia during the study was considered a prophylactic failure. Two hundred thirteen volunteers (92%) completed the study. The prophylactic efficacies were as follows: daily azithromycin, 82.7% (95% confidence interval [CI], 68.5%-91.1%); weekly azithromycin, 64.2% (95% CI, 47.1%-77.1%); and daily doxycycline, 92.6% (95% CI, 79.9%-97.5%). All regimens were well tolerated. We concluded that both 100 mg of doxycycline and 250 mg of azithromycin, given daily, were effective as prophylaxis for malaria in this setting. If studies with nonimmune volunteers confirm these results for semi-immune volunteers, a daily azithromycin regimen may have special utility for individuals with contraindications to treatment with doxycycline or other antimalarial agents.
Assuntos
Antibacterianos/uso terapêutico , Azitromicina/uso terapêutico , Doxiciclina/uso terapêutico , Malária/prevenção & controle , Adolescente , Adulto , Método Duplo-Cego , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos ProspectivosRESUMO
Loss of the p16INK4A gene by homozygous deletions or point mutations is attributed to the development of many types of cancers including leukemia. T cell acute lymphoblastic leukemias (T-ALLs) and B-cell ALLs show a remarkable rate of 75 and 20% homozygous deletion of this gene, respectively. Restoration of p16 expression in p16-deficient solid tumor cell lines results in a dramatic reduction of growth and maligant phenotype. To test the hypothesis that p16INK4A suppresses the growth of p16-deficient leukemias, we utilized a retroviral system to restore wild-type (wt) or mutant p16 protein expression. We tested the efficacy of our system by expressing the wt or mutant p16 genes in the osteosarcoma cell line, U20S, which lacks p16 and retains functional retinoblastoma protein (pRb). The wt p16 protein formed complexes with both cyclin-dependent kinases (CDK) 4 and 6 and inhibited U20S growth by 30-fold. The p16 mutants E120K and R144C formed complexes with CDK4 and CDK6 in cells and inhibited cell growth as effectively as wt p16 (20-fold) while the mutant proteins that did not complex with detectable levels of CDK4 or CDK6 only inhibited growth 0.25- and five-fold (G101W and D141, respectively) or not at all (H83Y and DA4). The COOH-terminal 'tail' of the wt p16 protein (amino acid residues 141-156), missing in mutant D141, enhanced the growth suppressive capability of p16. The amino acid substitutions in mutants G101W and H83Y not only disrupted CDK4 and CDK6 binding, but decreased the protein half-lives by two- and three-fold, respectively, compared to wt p16. The wt, but not mutant p16 genes, effectively inhibited the growth of T cell acute lymphoblastic (CEM) and myeloid leukemia (NB-4 and K562) cell lines that lacked the p16 gene, but retained functional pRb. Growth of the T-ALL cell line, HSB-2, which lacked both p16 and pRb, was not inhibited, indicating the growth suppression involved the pRb pathway. These results define regions critical for the function of p16 and demonstrate that restoration of wt p16 expression in p16-deficient leukemias significantly reverted their transformed phenotype and inhibited their growth.
Assuntos
Proteínas de Transporte/fisiologia , Leucemia/terapia , Animais , Células COS , Proteínas de Transporte/biossíntese , Proteínas de Transporte/genética , Divisão Celular/fisiologia , Inibidor p16 de Quinase Dependente de Ciclina , Quinases Ciclina-Dependentes/metabolismo , DNA de Neoplasias/genética , DNA de Neoplasias/metabolismo , Humanos , Leucemia/genética , Leucemia/metabolismo , Leucemia Eritroblástica Aguda/genética , Leucemia Eritroblástica Aguda/metabolismo , Leucemia Eritroblástica Aguda/terapia , Leucemia Mieloide/genética , Leucemia Mieloide/metabolismo , Leucemia Mieloide/terapia , Leucemia de Células T/genética , Leucemia de Células T/metabolismo , Leucemia de Células T/terapia , Mutação , Osteossarcoma/genética , Osteossarcoma/metabolismo , Sequências Repetitivas de Ácido Nucleico , Retroviridae/genética , Retroviridae/metabolismo , Células Tumorais CultivadasRESUMO
Tumor necrosis factor alpha (TNFalpha) is a cytotoxic/cytostatic compound for a variety of human cancer cells. The p21WAF1 protein is a cyclin-dependent kinase inhibitor (CDKI) that binds to cyclin/cyclin-dependent kinase (CDK) complexes and inhibits their kinase activities, thereby leading to cell cycle arrest. We found that the cytostatic effect of TNFalpha on the cervical cancer cell line, ME180, was concomitant with an arrest of these cells in the G0/G1 phase of the cell-cycle. This corresponded with an increase in both p21WAF1 mRNA and protein levels which likely occurred via a p53-independent pathway since ME180 is infected with the human papilloma virus. To elucidate the role of p21WAF1 in the TNFalpha-mediated growth and cell cycle arrest, we stably transformed ME180 cells with an antisense p21WAF1 expression vector. Two clones with reduced levels of p21WAF1 both in their basal state as well as after their exposure to TNFalpha were selected. The growth of these cells was still inhibited by TNFalpha and they arrested in G0/G1 similar to wildtype or empty vector transfected cells. These results indicate that although p21WAF1 expression increases dramatically with TNFalpha treatment, it may not play a critical role in the cytostatic effect of TNFalpha on ME180 cervical cancer cells.
Assuntos
Quinases Ciclina-Dependentes/antagonistas & inibidores , Ciclinas/fisiologia , Fator de Necrose Tumoral alfa/farmacologia , Ciclo Celular , Divisão Celular/efeitos dos fármacos , Inibidor de Quinase Dependente de Ciclina p21 , Ciclinas/metabolismo , Humanos , RNA Mensageiro/análise , Transformação Genética , Células Tumorais CultivadasRESUMO
Stimulus-induced acetylcholine (ACh) exocytosis from presynaptic nerve terminals involves two important steps: fusion of ACh loaded vesicles at presynaptic release sites, followed by release into the synaptic cleft. We studied the role of the putative vesicle fusion protein SNAP-25 in this process. The nerve growth factor-differentiated PC12 cell line was used as an experimental model. A bee venom tetradecapeptide (INLKALAALAKKIL-NH2) phospholipase A2 (PLA2) activator, mastoparan, was used to induce ACh release. Treatment of PC12 cells with appropriate antisense oligonucleotides blocked SNAP-25 expression, as judged by Western blot protein analysis with a specific monoclonal antibody. Despite apparent elimination of SNAP-25, treatment of differentiated PC12 cells with mastoparan and high (80 mM) K+ induced ACh exocytosis. The results indicate that in PC12 cells, ACh exocytosis due to mastoparan plus K+ can occur in the absence of SNAP-25.
Assuntos
Acetilcolina/metabolismo , Exocitose/fisiologia , Proteínas de Membrana , Proteínas do Tecido Nervoso/metabolismo , Células PC12/metabolismo , Animais , Western Blotting , Exocitose/efeitos dos fármacos , Peptídeos e Proteínas de Sinalização Intercelular , Neurotoxinas/farmacologia , Peptídeos , Cloreto de Potássio/farmacologia , Ratos , Proteína 25 Associada a Sinaptossoma , Venenos de Vespas/farmacologiaRESUMO
The current interest in leishmaniasis stems from the importance of this disease with respect to travel medicine, veterans of Operation Desert Storm, humanitarian concerns, and infection with human immunodeficiency virus. Herein, I review aspects of leishmaniasis that are of practical value to practitioners, including presentation, diagnosis, and chemotherapy; I will emphasize advances in chemotherapy over the last 10 years. Amphotericin B and its new lipid formulations are now competitive with pentavalent antimony as primary therapy for visceral leishmaniasis. Pentamidine, paromomycin, and adjunctive therapy with interferon-gamma are secondary regimens for the treatment of this condition. High-dose long-term regimens of antimony have been shown to be highly effective for the treatment of cutaneous leishmaniasis. Preliminary evidence of efficacy has been observed with short courses of pentamidine for the treatment of Leishmania braziliensis complex disease and topical paromomycin/methylbenzethonium chloride for the treatment of Leishmania major disease.