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1.
J Eur Acad Dermatol Venereol ; 35(3): 712-720, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-32896010

RESUMO

BACKGROUND: There is increasing use of anti-osteoporotic agents (AOA) worldwide for prevention or management of patients with osteoporosis. However, there have been reports of severe cutaneous adverse reactions (SCAR) induced by AOA. A recent study showed weak association between HLA and strontium ranelate (SR)-SCAR. OBJECTIVE: To characterize patients with AOA-SCAR and investigate the HLA association and utility of in vitro diagnostic methods. METHODS: We enrolled 16 cases with AOA-cutaneous adverse drug reactions (cADR), including SCAR (n = 10: 8 with Stevens-Johnson syndrome [SJS] and 2 with drug rash with eosinophilia and systemic symptoms [DRESS]) and maculopapular exanthema (MPE) (n = 6) from Taiwan and Hong Kong. We analysed the clinical characteristics, outcomes, HLA alleles and in vitro testing of AOA-SCAR, and tolerability to alternative drugs. We further performed literature review and meta-analysis on the HLA association of AOA-SCAR. RESULTS: Our data showed strontium ranelate is the most common causality of AOA-SCAR in Asian populations. There was no cross-hypersensitivity of SR-SCAR with other AOA. HLA genotyping showed that SR-SJS was most significantly associated with HLA-A*33:03 (Pc = 5.17 × 10-3 , OR: 25.97, 95% CI: 3.08-219.33). Meta-analysis showed that HLA-A*33:03 was associated with SR-SJS (P = 5.01 × 10-5 ; sensitivity: 85.7%) in Asians. The sensitivity of lymphocyte activation test (LAT) for identifying the culprit drug of SR-SJS was 83.3%. CONCLUSIONS: Strontium ranelate is identified as the most notorious AOA associated with SCAR. The HLA-A*33:03 genetic allele and LAT testing may add benefits to the diagnosis of SR-SCAR in patients whose reaction developed while taking multiple drugs.


Assuntos
Síndrome de Stevens-Johnson , Alelos , Anticonvulsivantes , Povo Asiático , Antígenos HLA-B/genética , Hong Kong , Humanos , Taiwan
2.
Diabet Med ; 35(1): 107-111, 2018 01.
Artigo em Inglês | MEDLINE | ID: mdl-29078006

RESUMO

AIM: To examine the associations between prostate cancer, diabetes and race/ethnicity. METHODS: Using administrative data from British Columbia, Canada for the period 1994 to 2012, we identified men aged ≥50 years with and without diabetes. Validated surname algorithms identified men as Chinese, Indian or of other race/ethnicity. Multivariable Cox regression was used to estimate adjusted risks of prostate cancer according to diabetes status and race/ethnicity. RESULTS: Our cohort of 160 566 men had a mean (sd) age of 64.7 (9.4) years and a median of 9 years' follow-up. The incidence rates of prostate cancer among those with and without diabetes were 177.4 (171.7-183.4) and 216.0 (209.7-222.5) per 1000 person-years, respectively. The incidence among Chinese men was 120.9 (109.2-133.1), among Indian men it was 144.1 (122.8-169.0) and in men of other ethnicity it was 204.8 (200.2-209.5). Diabetes was independently associated with a lower risk of prostate cancer (adjusted hazard ratio 0.82, 95% CI 0.78-0.86), as was Chinese (adjusted hazard ratio 0.54, 95% CI 0.46,0.63) and Indian (adjusted hazard ratio 0.66, 95% CI 0.49,0.89) race/ethnicity; however, there was no statistically significant interaction between diabetes status and race/ethnicity (all P>0.1). CONCLUSION: Diabetes and Chinese and Indian race/ethnicity were each independently associated with a lower risk of prostate cancer.


Assuntos
Povo Asiático/estatística & dados numéricos , Diabetes Mellitus/epidemiologia , Neoplasias da Próstata/etnologia , População Branca/estatística & dados numéricos , Idoso , Colúmbia Britânica/epidemiologia , Estudos de Coortes , Etnicidade/estatística & dados numéricos , Humanos , Incidência , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Modelos de Riscos Proporcionais , Neoplasias da Próstata/epidemiologia , Estudos Retrospectivos , Fatores de Risco
3.
Lupus ; 27(11): 1828-1837, 2018 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-30134759

RESUMO

Background Cutaneous lupus erythematosus (CLE) includes a broad range of dermatologic manifestations. Periorbital involvement, however, is a relatively rare clinical presentation of CLE. Objectives This clinical study aimed to investigate the characteristics of this unique presentation of CLE in tertiary medical centers. Methods We enrolled patients with periorbital erythema and swelling as the presenting sign of lupus erythematosus, from January 2003 to November 2017, using the data of 553 pathologically proven CLE cases from the registration database of the Chang Gung Memorial Hospitals in Taiwan. Results We enrolled a total of 25 patients. The mean age was 46.7 years and 68% of the patients were female. Most of the patients (84.0%) presented with unilateral involvement, with the left orbit involved in 15 patients (60%); the upper eyelid was the most frequently involved (72%). Mean duration between the onset of clinical manifestations and the diagnosis of CLE was approximately 59 weeks. Nineteen patients had been previously misdiagnosed. All patients had features compatible with CLE on histopathological examination. In contrast, laboratory analysis of the autoimmune profile often revealed negative results, including those for antinuclear antibodies (25%). Notably, anti-SSA/SSB (45.5%) showed the highest positive rate. During follow-up, six patients developed systemic lupus erythematosus (SLE) and two patients developed Sjögren syndrome. Conclusions The diagnosis of CLE presenting as periorbital erythema and swelling is often delayed because of clinical mimicry and the high proportion of negative results on autoantibody tests. Increased clinical suspicion and prompt histopathological examination are crucial for early diagnosis. Moreover, one-fourth of the patients ultimately developed SLE, which highlights the importance of clinical awareness.


Assuntos
Edema/patologia , Eritema/patologia , Lúpus Eritematoso Cutâneo/diagnóstico , Lúpus Eritematoso Cutâneo/patologia , Pele/patologia , Adulto , Idoso , Anticorpos Antinucleares/análise , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Taiwan , Centros de Atenção Terciária , Adulto Jovem
4.
J Eur Acad Dermatol Venereol ; 32(9): 1575-1583, 2018 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-29356140

RESUMO

BACKGROUND: Protothecosis is an uncommon infection caused by the achlorophyllic algae found more commonly in tropical areas. Only a limited number of cases have been reported. OBJECTIVE: We aimed to evaluate the clinicopathological features and treatment outcomes of cutaneous protothecosis. METHODS: We retrospectively identified 20 pathology-confirmed cases of cutaneous protothecosis based on skin biopsies in two tertiary medical centres in Taiwan from 1997 to 2015. RESULTS: The age of the patients at the time of diagnosis ranged from 48 to 85 years (mean age of 74 years). All lesions developed on the limbs. Twelve (60%) patients had adrenal insufficiency, but no patients had active malignancy at diagnosis. Interestingly, four (20%) patients had concurrent scabies infestation. Clinically, most lesions were erythematous plaques studded with punctate ulcers. Microscopically, the most common finding was granulomatous inflammation. Nineteen (95%) cases were successfully treated with itraconazole for 14-148 days with only one case of recurrence. Concomitant scabies should be suspected if pruritus is recalcitrant despite itraconazole treatment. CONCLUSION: Despite its rarity, cutaneous protothecosis has become more significant due to an increased prevalence of immunocompromised individuals. Steroid overuse or iatrogenic adrenal insufficiency predisposes individuals to high-risk infections. Neglecting the disease leads to a chronic and incurable state. Protothecosis should be suspected in chronic eczematous and ulcerative plaques on the limbs refractory to conventional antibacterial and antiviral treatments, especially in patients with adrenal insufficiency. Clinical suspicion should be confirmed by skin biopsies, and confirmed cases can be successfully treated with itraconazole.


Assuntos
Prototheca , Escabiose/complicações , Dermatopatias Infecciosas/complicações , Insuficiência Adrenal/induzido quimicamente , Insuficiência Adrenal/complicações , Idoso , Idoso de 80 Anos ou mais , Antifúngicos/uso terapêutico , Complicações do Diabetes/complicações , Eritema/microbiologia , Feminino , Humanos , Itraconazol/uso terapêutico , Masculino , Pessoa de Meia-Idade , Doenças Musculoesqueléticas/complicações , Prurido/parasitologia , Estudos Retrospectivos , Fatores de Risco , Dermatopatias Infecciosas/tratamento farmacológico , Dermatopatias Infecciosas/patologia , Úlcera Cutânea/microbiologia
8.
J Clin Pharm Ther ; 40(6): 689-92, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26365588

RESUMO

WHAT IS KNOWN AND OBJECTIVE: Febuxostat is recommended as an alternative drug for gouty patients with a history of allopurinol hypersensitivity or carrying the HLA-B*5801 allele. CASE SUMMARY: An 81-year-old man with the medical history of gout presented to our clinic with generalized rashes for 2 days. After taking febuxostat for 2 days, he developed generalized skin rash with high fever. Laboratory tests showed elevated liver enzymes and acute kidney injury. WHAT IS KNOWN AND OBJECTIVE: This is the first identified case of febuxostat-associated DRESS. Febuxostat should be withdrawn immediately when DRESS is observed to avoid further serious complications.


Assuntos
Síndrome de Hipersensibilidade a Medicamentos/etiologia , Eosinofilia/induzido quimicamente , Febuxostat/efeitos adversos , Idoso de 80 Anos ou mais , Febuxostat/uso terapêutico , Gota/tratamento farmacológico , Humanos , Masculino
9.
Luminescence ; 30(7): 1004-10, 2015 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-25640921

RESUMO

The binding interaction of lovastatin with calf thymus DNA (ct-DNA) was studied using UV/Vis absorption spectroscopy, fluorescence emission spectroscopy, circular dichroism (CD), viscosity measurement and molecular docking methods. The experimental results showed that there was an obvious binding interaction of lovastatin with ct-DNA and the binding constant (Kb ) was 5.60 × 10(3) M(-1) at 298 K. In the binding process of lovastatin with ct-DNA, the enthalpy change (ΔH(0)) and entropy change (ΔS(0)) were -24.9 kJ/mol and -12.0 J/mol/K, respectively, indicating that the main binding interaction forces were van der Waal's force and hydrogen bonding. The molecular docking results suggested that lovastatin preferred to bind on the minor groove of different B-DNA fragments and the conformation change of lovastatin in the lovastatin-DNA complex was obviously observed, implying that the flexibility of lovastatin molecule plays an important role in the formation of the stable lovastatin-ct-DNA complex.


Assuntos
DNA/química , Lovastatina/química , Simulação de Acoplamento Molecular , Animais , Bovinos , Dicroísmo Circular , Espectrometria de Fluorescência , Espectrofotometria Ultravioleta , Viscosidade
11.
J Viral Hepat ; 20 Suppl 1: 27-39, 2013 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-23458522

RESUMO

α-Galactosylceramide (α-GalCer)-activated natural killer T (NKT) cells have antiviral properties against hepatitis B virus (HBV). However, α-GalCer activation of NKT cells can induce anergy. We hypothesized that this effect may be overcome by a treatment strategy that includes manipulation of CD28/CD80 costimulatory and PD-1/PDL1 coinhibitory signals of NKT cells, thereby enhancing the anti-HBV effect of α-GalCer. We established a transgenic mouse model of chronic HBV infection and investigated hepatic NKT cell frequencies, functions and expression of immunomodulatory factors. Our results showed that compared with uninfected control mice, hepatic NKT cells from HBV transgenic mice displayed lower frequencies (7.91% vs 16.74%, P < 0.05), impaired capabilities to produce interferon (IFN)-γ (5.6% vs 1.4%, P < 0.05) and interleukin (IL)-4 (6.8% vs 0.3%, P < 0.05), higher expression of PD-1 (9.64% vs 6.36%, P < 0.05) and lower expression of CD28 (5.05% vs 28.88%, P < 0.05). However, when hepatic mononuclear cells (MNCs) were isolated from HBV transgenic mice, α-GalCer exposure in culture remarkably upregulated both PD-1(+) NKT cells (P < 0.05) and CD28(+) NKT cells (P < 0.05). Furthermore, when HBV transgenic mice were treated with combination therapies consisting of α-GalCer and anti-PDL1 monoclonal antibody (mAb) and/or anti-CD80/anti-CD28 mAbs, IFN-γ(+) NKT cell frequency was selectively increased (P < 0.05) and HBV replication was suppressed; these effects were accompanied by varying degrees and types of liver damage. Surprisingly, activating CD28/CD80 signal in HBV transgenic mice was more effective but caused less liver injury than blocking PD-1/PDL1 signal in modulating αGalCer-activated NKT cell function to inhibit HBV infection. Our findings also show that combined therapy with blocking PD-1/PDL1 and activating CD28/CD80 signal in the presence of aGalCer cannot superimpose the effect of antivirus. α-GalCer combination therapy that modulates the CD28/CD80 pathways of NKT cells may represent a promising approach to inhibit HBV replication in chronically infected patients.


Assuntos
Vírus da Hepatite B/fisiologia , Hepatite B Crônica/imunologia , Células T Matadoras Naturais/imunologia , Receptores Imunológicos/imunologia , Replicação Viral/imunologia , Animais , Anticorpos Monoclonais/administração & dosagem , Anticorpos Monoclonais/imunologia , Antígeno B7-1/imunologia , Antígeno B7-1/metabolismo , Antígeno B7-H1/imunologia , Antígeno B7-H1/metabolismo , Antígenos CD28/imunologia , Antígenos CD28/metabolismo , China , Modelos Animais de Doenças , Feminino , Citometria de Fluxo , Galactosilceramidas/administração & dosagem , Galactosilceramidas/imunologia , Galactosilceramidas/farmacologia , Vírus da Hepatite B/efeitos dos fármacos , Vírus da Hepatite B/genética , Hepatite B Crônica/tratamento farmacológico , Hepatite B Crônica/virologia , Humanos , Ativação Linfocitária , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Células T Matadoras Naturais/metabolismo , Receptor de Morte Celular Programada 1/imunologia , Receptor de Morte Celular Programada 1/metabolismo , Receptores Imunológicos/metabolismo , Resultado do Tratamento
12.
J Neonatal Perinatal Med ; 16(4): 735-740, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38073401

RESUMO

Trisomy 21 (Down Syndrome) may lead to multiple hematological and hepatobiliary manifestations including the development of transient abnormal myelopoiesis. While many cases resolve, transient abnormal myelopoiesis may lead to significant morbidity and mortality in a small percentage of patients. This condition may present a diagnostic challenge for physicians and currently there is only limited data on effective treatments, particularly with low blast percent transient abnormal myelopoiesis. We present a case of a neonate with trisomy 21 and multiple congenital anomalies who consequently developed hepatic failure with evidence of non-cirrhotic portal hypertension likely due to transient abnormal myelopoiesis. This clinical scenario highlights the need for additional evaluation for transient abnormal myelopoiesis associated hepatic disorder and possibly hepatic sinusoidal occlusive syndrome among trisomy 21 neonates particularly with low blast percentage.


Assuntos
Síndrome de Down , Doenças do Recém-Nascido , Reação Leucemoide , Recém-Nascido , Humanos , Síndrome de Down/complicações , Reação Leucemoide/diagnóstico , Resultado do Tratamento
13.
Eur Rev Med Pharmacol Sci ; 23(22): 10151-10160, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31799687

RESUMO

OBJECTIVE: To assess the effect of omega-3 polyunsaturated fatty acids (n-3 PUFA) on liver regeneration of rats with liver cirrhosis after hepatectomy and antifibrosis. MATERIALS AND METHODS: Omega-3 polyunsaturated fatty acids were intravenously injected in n-3 PUFA group 3 days before the operation to 1 day after partial hepatectomy. 70% hepatectomy was performed in rats, which were subsequently divided into 4 groups, namely normal and hepatectomy group (PH); liver cirrhosis and hepatectomy group (LC+PH); liver cirrhosis, n-3 PUFA (1 mL/kg), and hepatectomy group (LC+n-3 PUFA+PH); liver cirrhosis, n-3 PUFA (2 mL/kg) and hepatectomy group (LC+n-3PUFA*+PH). Body/liver weight ratios, serum parameters, histopathological examination, immunostaining, inflammatory cytokine and quantification of mRNA expression were also investigated. RESULTS: Liver regeneration was significantly delayed compared with PH group 7 days after hepatectomy (PH) in LC+PH group. Besides, liver regeneration of LC+n-3 PUFA*+PH group increased significantly compared with LC+PH group 7 days after PH. In LC+PH group, liver cirrhotic was significantly higher compared with LC+n-3 PUFA+PH group 7 days after PH. In the meantime, liver cirrhosis of LC+n-3 PUFA*+PH group was significantly reduced compared with LC+n-3 PUFA+PH group 7 days after PH. Anti-inflammatory cytokine IL-10 was increased and pro-inflammatory cytokine IL-6 was decreased in LC+n-3 PUFA*+PH group compared with LC+PH group. N-3 PUFA also suppressed increments in mRNA expression for transforming growth factor-ß and up-regulated the expression of matrix metalloproteinase-9 and matrix metalloproteinase-1 in the liver. CONCLUSIONS: The mentioned results clearly show that n-3 PUFA reduces liver fibrosis and promotes liver regeneration, even under cirrhotic conditions. This could be a potentially useful treatment for liver cirrhosis.


Assuntos
Ácidos Graxos Ômega-3/administração & dosagem , Hepatectomia/efeitos adversos , Cirrose Hepática/dietoterapia , Regeneração Hepática/efeitos dos fármacos , Animais , Citocinas/genética , Citocinas/metabolismo , Progressão da Doença , Ácidos Graxos Ômega-3/farmacologia , Injeções Intravenosas , Cirrose Hepática/genética , Masculino , Ratos , Resultado do Tratamento
14.
Prostate Cancer Prostatic Dis ; 20(1): 122-126, 2017 03.
Artigo em Inglês | MEDLINE | ID: mdl-28071672

RESUMO

BACKGROUND: Men with diabetes may have a lower risk of prostate cancer than men without diabetes which may be altered by metformin use or race/ethnicity. METHODS: Using administrative databases, from 1994 to 2012, adult (age⩾50 years) men with diabetes were identified. Metformin exposure was defined as a time-dependent variable, stratified first into any use, and into tertiles of cumulative dose. Surname algorithms identified individuals as Chinese or non-Chinese. Multivariable Cox regression estimated the risk of prostate cancer. RESULTS: The cohort of 80 001 had a mean age of 64 years and median follow-up of 9 years. Chinese users of metformin aged 50-59, 60-69 and ⩾70 had similar risks of prostate cancer as non-users. Non-Chinese users aged 50-59 (adjusted hazards ratio (aHR): 0.86, 0.74 to 1.00) had a decreased risk whereas men aged 60-69 and ⩾70 did not. However, when metformin exposure was stratified into tertiles, there was no association in any strata except non-Chinese men aged 50-59 in the first (aHR: 0.68, 95% confidence interval (CI): 0.55, 0.84), second (aHR: 0.75, 95% CI: 0.61, 0.92) and third (aHR: 0.79, 95% CI: 0.64, 0.96) tertiles of metformin exposure and non-Chinese men aged 60-69 in the first (aHR: 0.81, 95% CI: 0.68, 0.95) tertiles of metformin exposure. CONCLUSIONS: There was no clear association between metformin and risk of prostate cancer in men with diabetes in either race/ethnicity. Our findings suggest a consistent relationship between metformin and prostate cancer across race/ethnicity.


Assuntos
Diabetes Mellitus Tipo 2/complicações , Hipoglicemiantes/efeitos adversos , Metformina/efeitos adversos , Grupos Populacionais/estatística & dados numéricos , Neoplasias da Próstata/epidemiologia , Neoplasias da Próstata/etiologia , Idoso , Idoso de 80 Anos ou mais , Colúmbia Britânica/epidemiologia , Estudos de Coortes , Diabetes Mellitus Tipo 2/tratamento farmacológico , Seguimentos , Humanos , Hipoglicemiantes/uso terapêutico , Masculino , Metformina/uso terapêutico , Pessoa de Meia-Idade , Vigilância da População , Modelos de Riscos Proporcionais , Estudos Retrospectivos , Risco , Fatores Socioeconômicos
15.
J Natl Cancer Inst ; 60(4): 819-24, 1978 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-633391

RESUMO

The formation of tobacco-specific nitrosamines from the major tobacco alkaloid nicotine was examined. Detached leaf tobacco was fed either [2'-14C]nicotine or [2'-14C]nornicotine and air cured. The cured leaf was then analyzed for [2'-14C]N'-nitrosonornicotine ([2'-14C]NNN). The yield of [2'-14C]NNN was 0.007% from nornicotine and 0.009% from nicotine. Because the ratio of nicotine to nornicotine in conventional nicotine-type tobacco is 20-100:1, nicotine is considered to be the major precursor for the carcinogen NNN in tobacco. The formation of other nitrosamines from nicotine in vitro was then studied. Reaction of nicotine with NaNO2 gave rise to NNN, as well as to two other nitrosamines, 4-(N-methyl-N-nitrosamino)-1-(3-pyridyl)-1-butanone (NNK) and 4-(N-methyl-N-nitrosamino)-4-(3-pyridyl)butanal (NNA). Analysis of market products revealed the presence of NNK (0.6-24 microgram/g) in chewing tobacco and snuff. The tumorigenic activity of NNN, NNK, and NNA in strain A mice was studied. NNK induced more lung adenomas per mouse than did NNN, whereas NNA was less active than NNN. In addition, two cases of undifferentiated carcinoma of the salivary glands occurred in the NNN experimental groups.


Assuntos
Adenoma/induzido quimicamente , Neoplasias Pulmonares/induzido quimicamente , Nicotiana/metabolismo , Nitrosaminas/metabolismo , Plantas Tóxicas , Animais , Feminino , Técnicas In Vitro , Camundongos , Camundongos Endogâmicos A , Neoplasias Experimentais/induzido quimicamente , Nicotina/análogos & derivados , Nicotina/metabolismo , Nicotina/toxicidade , Piridinas/metabolismo
16.
Cancer Res ; 40(11): 4144-50, 1980 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-7471055

RESUMO

The metabolism of the tobacco-specific carcinogen, 4-(N-methyl-N-nitrosamino)-1-(3-pyridyl)-1-butanone (NNK), was studied in the F344 rat, in which it induces tumors of the nasal cavity, liver, and lung. When NNK was incubated with rat liver microsomes and a reduced nicotinamide adenine dinucleotide phosphate-generating system, metabolites resulting from alpha-hydroxylation, carbonyl reduction, and N-oxidation were isolated. alpha-Hydroxylation at the methylene carbon gave 4-oxo-4-(3-pyridyl)butanal, whereas alpha-hydroxylation at the methyl carbon gave myosmine and 4-hydroxyl-1-(3-pyridyl)butan-1-one. The formation of these products involved the intermediacy of electrophilic diazohydroxides or carbonium ions which may be proximate or ultimate carcinogens of NNK. Carbonyl reduction gave 4-(N-methyl-N-nitrosamino)-1-(3-pyridyl)butan-1-ol and N-oxidation yielded 4-(N-methyl-N-nitrosamino)-1-(3-pyridyl-N-oxide)-1-butanone. When rats were gavaged with NNK, the microsomal products of alpha-hydroxylation were not detected in the 48-hr urine. Compounds which presumably resulted from further oxidation or reduction of these products, 4-oxo-4-(3-pyridyl)butyric acid, 4-hydroxy-4-(3-pyridyl)butyric acid, and 4-hydroxy-1-(3-pyridyl)butan-1-ol, were isolated. 4-(N-Methyl-N-nitrosamino)-1-(3-pyridyl)butan-1-ol and 4-(N-methyl-N-nitrosamino)-1-(3-pyridyl-N-oxide)-1 butanone were also urinary metabolites.


Assuntos
Carcinógenos/metabolismo , Nitrosaminas/metabolismo , Ratos Endogâmicos F344/metabolismo , Ratos Endogâmicos/metabolismo , Animais , Biotransformação , Hidroxilação , Microssomos Hepáticos/metabolismo , Oxirredução , Plantas Tóxicas , Piridinas/metabolismo , Ratos , Nicotiana
17.
Cancer Res ; 38(1): 215-8, 1978 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-618576

RESUMO

Metabolic alpha hydroxylation of cyclic nitrosamines is important in the activation of these compounds to their ultimate carcinogenic forms. Direct evidence for this process is presented. Both alpha-hydroxynitrosopyrrolidine and 3-formyl-1-propanediazohydroxide, which are unstable intermediates resulting from alpha hydroxylation of nitrosopyrrolidine, were generated inaqueous solution from the stable precursors alpha-acetoxynitrosopyrrolidine and 4-(N-carbethoxy-N-nitrosamino)butanal. The major product resulting from the decomposition of slpha-hydroxynitrosopyrrolidine and 3-formyl-1-propanediazohydroxide was 2-hydroxytetrahydrofuran, the cyclic hemiacetal of 4-hydroxy-butyraldehyde. The same product was isolated as its dinitrophenylhydrazone derivative after incubation of rat liver microsomes with nitrosopyrrolidine and after treatment of rats with nitrosopyrrolidine.


Assuntos
Microssomos Hepáticos/metabolismo , Nitrosaminas/metabolismo , Pirrolidinas/metabolismo , Animais , Fenômenos Químicos , Química , Hidroxilação , Técnicas In Vitro , Masculino , Ratos
18.
Cancer Res ; 40(2): 298-302, 1980 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-7356512

RESUMO

The tobacco-specific carcinogens, N'-nitrosonornicotine (NNN) and 4-(N-methyl-N-nitrosamino)-1-(3-pyridyl)-1-butanone (NNK), were tested for carcinogenicity in F344 rats. Each nitrosamine in trioctanoin was administered by s.c. injection to 12 male and 12 female rats over a period of 20 weeks. The total dose of each nitrosamine was 3.4 mmol. The experiment was terminated after 12 months. NNK induced nasal cavity tumors in 83% of the males and in 83% of the females, liver tumors in 83% of the males and in 100% of the females, and lung tumors in 67% of the males and in 67% of the females. NNN induced nasal cavity tumors in 92% of the males and in 75% of the females. Only one liver tumor and no lung tumors were observed in the NNN-treated rats. These results indicate that, in the F344 rat, NNK is a more powerful carcinogen than is NNN.


Assuntos
Carcinógenos , Neoplasias Experimentais/induzido quimicamente , Nicotiana , Nicotina/análogos & derivados , Nitrosaminas/toxicidade , Plantas Tóxicas , Animais , Feminino , Neoplasias Hepáticas/induzido quimicamente , Neoplasias Pulmonares/induzido quimicamente , Masculino , Cavidade Nasal , Neoplasias Experimentais/patologia , Nicotina/toxicidade , Neoplasias Nasais/induzido quimicamente , Piridinas/toxicidade , Ratos , Ratos Endogâmicos F344
19.
Cancer Res ; 38(11 Pt 1): 3812-6, 1978 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-698939

RESUMO

A high-pressure liquid chromatographic assay for alpha hydroxylation of N-nitrosopyrrolidine by isolated hepatic microsomes was developed. Mixtures consisting of N-nitrosopyrrolidine, microsomes, and an NADPH-generating system were incubated at 37 degrees. The major product of alpha hydroxylation of N-nitrosopyrrolidine, 2-hydroxytetrahydrofuran, was trapped by the addition of 2,4-dinitrophenylhydrazine reagent to form 4-hydroxybutyraldehyde-2,4-dinitrophenylhydrazone. The latter was quantified by reverse-phase high-pressure liquid chromatography. Under optimal conditions, as determined by varying protein and substrate concentrations, the alpha hydroxylation of N-nitrosopyrrolidine was linear for at least 90 min and showed characteristics typical of the microsomal mixed-function oxidase system, such as inhibition by CO and induction by pretreatment of male F-344 rats with Aroclor. N-Nitrosopyrrolidine exhibited type II spectral changes upon interaction with isolated hepatic microsomes. A close correspondence between binding affinity and alpha hydroxylation of N-nitrosopyrrolidine was observed.


Assuntos
Microssomos Hepáticos/metabolismo , N-Nitrosopirrolidina/metabolismo , Nitrosaminas/metabolismo , Animais , Arocloros/farmacologia , Biotransformação , Fenômenos Químicos , Química , Cromatografia Líquida de Alta Pressão , Hidroxilação , Técnicas In Vitro , Masculino , Microssomos Hepáticos/efeitos dos fármacos , Ratos , Ratos Endogâmicos F344
20.
Mini Rev Med Chem ; 16(11): 917-25, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-26948324

RESUMO

Cerebral edema causes intracranial hypertension (ICH) which leads to severe outcome of patients in the clinical setting. Effective anti-edema therapy may significantly decrease the mortality in a variety of neurological conditions. At present drug treatment is a cornerstone in the management of cerebral edema. Osmotherapy has been the mainstay of pharmacologic therapy. Mannitol and hypertonic saline (HS) are the most commonly used osmotic agents. The relative safety and efficacy of HS and mannitol in the treatment of cerebral edema and reduction of enhanced ICP have been demonstrated in the past decades. Apart from its osmotic force, HS exerts anti-edema effects partly through inhibition of Na(+)-K(+)-2Cl(-) Cotransporter-1 (NKCC1) and aquaporin 4 (AQP4) expression in astrocytes. Melatonin may also reduce brain edema and exert neuroprotective effect on several central nervous system diseases through inhibition of inflammatory response. The inhibitors of Na/H exchanger, NKCC and AQP4 may attenuate brain edema formation through inhibition of excessive transportation of ion and water from blood into the cerebral tissue. In this review we survey some of the most recent findings in the drug treatment of brain edema focusing on the use of osmotherapy, melatonin and inhibitors of ion cotransporters and water channels. A better understanding of the molecular mechanism of these agents would help to improve in the clinical management of patients with brain edema.


Assuntos
Edema Encefálico/tratamento farmacológico , Encéfalo/efeitos dos fármacos , Animais , Aquaporina 4/antagonistas & inibidores , Aquaporina 4/metabolismo , Encéfalo/metabolismo , Encéfalo/patologia , Edema Encefálico/metabolismo , Edema Encefálico/patologia , Hidratação/métodos , Humanos , Manitol/farmacologia , Manitol/uso terapêutico , Melatonina/farmacologia , Melatonina/uso terapêutico , Fármacos Neuroprotetores/farmacologia , Fármacos Neuroprotetores/uso terapêutico , Solução Salina Hipertônica/farmacologia , Solução Salina Hipertônica/uso terapêutico , Membro 2 da Família 12 de Carreador de Soluto/metabolismo , Simportadores/antagonistas & inibidores
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