RESUMO
Within a few months a 31-year-old female patient was diagnosed with a psammomatous melanotic schwannoma, an atrial myxoma and microfollicular adenomas in both thyroid lobes. Therefore, sufficient diagnostic criteria of a Carney complex were fulfilled. The Carney complex is an inherited autosomal dominant disorder with highly variable phenotypes, which was initially described by Carney in 1985 as a complex of myxomas, spotty skin pigmentation and endocrine overactivity. Pathologists should consider this differential diagnosis in reports when confronted with a psammomatous melanotic schwannoma.
Assuntos
Adenoma/patologia , Complexo de Carney/patologia , Neoplasias Cardíacas/patologia , Mixoma/patologia , Neoplasias Primárias Múltiplas/patologia , Neurilemoma/patologia , Neoplasias da Glândula Tireoide/patologia , Adenoma/genética , Adulto , Complexo de Carney/genética , Subunidade RIalfa da Proteína Quinase Dependente de AMP Cíclico/genética , Análise Mutacional de DNA , Diagnóstico Diferencial , Feminino , Neoplasias de Cabeça e Pescoço/genética , Neoplasias de Cabeça e Pescoço/patologia , Átrios do Coração/patologia , Neoplasias Cardíacas/genética , Humanos , Mixoma/genética , Neoplasias Primárias Múltiplas/genética , Neurilemoma/genética , Fenótipo , Transdução de Sinais/genética , Glândula Tireoide/patologia , Neoplasias da Glândula Tireoide/genéticaRESUMO
Aerobic glycolysis, a metabolic characteristic of malignant cells, can be exploited to increase the concentration of lactic acid selectivity in tumor tissues in vivo by systemic administration of glucose (E. Jähde and M. F. Rajewsky, Cancer Res., 42: 1505-1512, 1982). To investigate whether a more acidic microenvironment can enhance the effectiveness of cytocidal drugs, we have analyzed the colony-forming capacity of M1R rat mammary carcinoma cells exposed to bis-chloroethylating agents in culture as a function of extracellular pH (pHe). At pHe 6.2 the cytotoxicity of 4-hydroperoxycyclophosphamide, as measured by inhibition of colony formation, was potentiated by a factor of approximately 200 as compared to pHe 7.4. Similar results were obtained with mafosfamide, nitrogen mustard, nornitrogen mustard, melphalan, and chlorambucil; not, however, with ifosfamide. As indicated by experiments using the ionophor nigericin for rapid equilibration of pHe and intracellular pH (pHi; measured with pH-sensitive microelectrodes), modulation of drug action by varying pHe primarily resulted from the concomitant decrease in pHi. The acidic microenvironment enhanced cytotoxicity most effectively during the phase of cellular drug uptake and monofunctional alkylation of DNA. DNA cross-link formation appeared to be less affected by pH, and lowering of pHe during the phase of cross-link removal was only marginally effective.
Assuntos
Ciclofosfamida/farmacologia , Concentração de Íons de Hidrogênio , Neoplasias Mamárias Experimentais/tratamento farmacológico , Alquilantes/farmacologia , Animais , Clorambucila/intoxicação , Ciclofosfamida/análogos & derivados , Neoplasias Mamárias Experimentais/metabolismo , Neoplasias Mamárias Experimentais/patologia , Melfalan/farmacologia , Compostos de Mostarda Nitrogenada/farmacologia , Ratos , Relação Estrutura-Atividade , Ensaio Tumoral de Célula-TroncoRESUMO
Based on the findings that the pH in malignant tumors can be preferentially decreased by stimulation of their aerobic glycolysis, acid-sensible prodrugs, which are nearly nontoxic at physiological pH, were synthesized. At lower pH, however, these compounds are cleaved with liberation of a cytotoxic species. The prototypic drug compound 2-hexenopyranoside of aldophosphamide was prepared, which releases aldophosphamide by acid-catalyzed hydrolysis. Exposure of cultured M1R rat mammary carcinoma cells to this agent at pH 7.4 only resulted in slight toxicity. However, when drug treatment was performed at pH 6.2, the mean pH in malignant tumors of hyperglycemic hosts, the colony-forming fraction of M1R cells decreased to 0.05 and 0.0001 of controls treated at pH 7.4 after exposure for 24 h and 48 h, respectively. The synthesis of the 2-hexenopyranoside of aldophosphamide is described in detail.
Assuntos
Antineoplásicos/metabolismo , Mostardas de Fosforamida/metabolismo , Pró-Fármacos/metabolismo , Animais , Biotransformação , Sobrevivência Celular/efeitos dos fármacos , Glicólise , Concentração de Íons de Hidrogênio , Ratos , Células Tumorais Cultivadas/efeitos dos fármacosRESUMO
Domino reactions are highly efficient processes that allow the synthesis of complex molecules starting from simple substrates, in a straightforward fashion. The transformations are extremely useful for the design of small-molecule libraries by combinatorial chemistry if multicomponent domino reactions are employed. The reactions can be performed in solution, as well as on solid support, and give access to highly diverse molecules; in addition, their use in automated synthesis is possible.
Assuntos
Química Orgânica/métodos , Desenho de Fármacos , Indicadores e Reagentes , Estrutura Molecular , Relação Estrutura-AtividadeRESUMO
This review is a survey of two approaches for a selective anticancer therapy that are based on a specific cleavage of specially designed non-toxic prodrugs with the liberation of a cytotoxic compound either by antibody-enzyme conjugates targeted to tumor-associated antigens or by acid-catalyzed hydrolysis of the prodrugs due to the increased concentration of hydronium ions in malignant tissue under hyperglycemic conditions. Herein, the design, synthesis and the biological testing of prodrugs are described.
Assuntos
Enzimas , Neoplasias/terapia , Pró-Fármacos/uso terapêutico , Prótons , Animais , Anticorpos Monoclonais/administração & dosagem , Anticorpos Monoclonais/metabolismo , Antígenos de Neoplasias , Sobrevivência Celular/efeitos dos fármacos , Enzimas/administração & dosagem , Enzimas/metabolismo , Humanos , Neoplasias/patologia , Pró-Fármacos/química , Células Tumorais CultivadasRESUMO
Chemical conjugation of appropriate carbohydrate ligands to an inert labeled carrier renders probes available to screen for the presence of respective binding sites. A set with a certain plant lectin and a suitable neoglycoprotein can thus determine complementary parts of a potentially relevant glycobiological interaction system. Owing to the interest in the peanut agglutinin-reactive T-antigen, we performed chemical synthesis of the respective disaccharide structure to serve as glycohistochemical ligand and established refinements of the synthetic patway. Coupling of the derivatized monomers had to be performed in the presence of sodium sulfate for optimal results. Complete removal of the protective groups from the p-nitrophenyl derivative of the N-acetylgalactosamine moiety was achieved under mild conditions with 2,3-dichloro-5,6-dicyanobenzoquinone without affecting any other functional groups. Specific binding sites for the synthetic neoglycoprotein as well as for the plant lectin were demonstrated in cell lines of human breast carcinoma colon adenocarcinoma, and erythroleukemia. ABC reagents in conjunction with DAB as peroxidase substrate were used to visualize specific binding sites. Binding complied with the accepted criteria for specificity. Moreover, carbohydrate-specific binding sites were detected in sections of nine out of 14 cases with malignant breast lesions. The percentage of positive tumor cells with both neoglycoprotein and lectin was similar in each of the individual sections, regardless of quantitative variations between cases, lectin staining intensity often being more pronounced. The reactivity pattern in sections of primary and metastatic lesions was not significantly correlated with the lymph node status. This study emphasized that custom synthesis of saccharides and histochemical application of the resulting neoglycoprotein has a remarkable potential for complementary assessment of endogenous binding sites for carbohydrate structures, localized by external tools such as plant lectins, as a step to elucidate the importance of a putative proteincarbohydrate interaction.
Assuntos
Adenocarcinoma/patologia , Antígenos de Diferenciação de Linfócitos T/imunologia , Antígenos Glicosídicos Associados a Tumores/metabolismo , Neoplasias da Mama/patologia , Neoplasias do Colo/patologia , Glicoproteínas/metabolismo , Histocitoquímica/métodos , Lectinas/metabolismo , Leucemia Eritroblástica Aguda/patologia , Receptores de Antígenos de Linfócitos T/metabolismo , Adenocarcinoma/metabolismo , Adenocarcinoma/ultraestrutura , Neoplasias da Mama/metabolismo , Neoplasias da Mama/ultraestrutura , Neoplasias do Colo/metabolismo , Neoplasias do Colo/ultraestrutura , Glicoproteínas/imunologia , Humanos , Leucemia Eritroblástica Aguda/metabolismo , Aglutinina de Amendoim , Células Tumorais Cultivadas/metabolismo , Células Tumorais Cultivadas/patologia , Células Tumorais Cultivadas/ultraestruturaRESUMO
A decreased fibrinolytic activity of serosal surfaces appears to be a major factor in the development of peritoneal fibrous adhesions. Serosal fibrinolysis is regulated by mesothelial release of tissue type plasminogen activator (t-PA) and plasminogen activator inhibitor types 1 and 2 (PAI-1 and PAI-2). We investigated the influence of tumor necrosis factor alpha (TNF-alpha), transforming growth factor beta (TGF-beta1) and interleukin 1beta (IL-1beta) on pro- and antifibrinolytic properties of mesothelial cells (HOMC) using a cell/fibrin clot assay. TGF-beta1, TNF-alpha and IL-1beta induced a dose dependent 2.9, 2.3 and 1.9-fold increase of PAI-1 antigen, respectively, whereas t-PA concentrations decreased to one third of the control values. This modified PAI-1/t-PA secretion pattern leads to a significant delay of fibrinolysis. Analysis of m-RNA levels revealed increased PAI-1 m-RNA concentrations after 12 h and decreased m-RNA concentrations for t-PA after 6 h. Serosal hypofibrinolysis during peritonitis may be explained at least in part by cytokine effects which thus may favor adhesion formation.
Assuntos
Fibrinólise/fisiologia , Interleucina-1/farmacologia , Peritônio/citologia , Peritônio/fisiologia , Fator de Crescimento Transformador beta/farmacologia , Fator de Necrose Tumoral alfa/farmacologia , Adesão Celular/efeitos dos fármacos , Células Cultivadas , Epitélio/efeitos dos fármacos , Epitélio/fisiologia , Fibrinólise/efeitos dos fármacos , Humanos , Inibidor 1 de Ativador de Plasminogênio/biossínteseRESUMO
The present study was aimed at evaluating the effect of the matrix metalloproteinase (MMP) inhibitor prinomastat (AG3340) on tumor progression using an orthotopic pancreatic carcinoma model in severe combined immunodeficient mice. In controls, receiving vehicle only, the poorly differentiated ductal adenocarcinoma invaded into adjacent organs and metastasized to different sites in the abdomen and to the lungs. Treatment with prinomastat, intraperitoneally twice daily for 21 days, reduced primary tumor volume significantly to 19.0 (+/-7.7)% of control, with induction of necrosis, differentiation, and fibrotic tissue in the pancreatic tumors. Invasion was not observed in 63% of prinomastat-treated mice, and metastases were reduced markedly. Surprisingly, prinomastat-treated tumors had on average higher microvessel densities as a consequence of an increased angiogenesis in perinecrotic tumor areas. We conclude that prinomastat is highly effective in inhibiting pancreatic carcinoma growth and progression in an orthotopic cancer model. This model appears to be a valuable tool to investigate the potency of novel antimetastatic strategies in pancreatic ductal adenocarcinoma by specifically targeting certain MMPs.
Assuntos
Adenocarcinoma/tratamento farmacológico , Adenocarcinoma/metabolismo , Antineoplásicos/farmacologia , Carcinoma Ductal Pancreático/tratamento farmacológico , Carcinoma Ductal Pancreático/metabolismo , Compostos Orgânicos , Neoplasias Pancreáticas/tratamento farmacológico , Neoplasias Pancreáticas/metabolismo , Animais , Antígenos CD34/biossíntese , Diferenciação Celular/efeitos dos fármacos , Feminino , Fibrose , Humanos , Imuno-Histoquímica , Masculino , Inibidores de Metaloproteinases de Matriz , Camundongos , Camundongos SCID , Necrose , Invasividade Neoplásica , Transplante de Neoplasias , Células Tumorais CultivadasRESUMO
The manipulation of stress gene expression by heavy metals provides protection against the lethal effects of endotoxemia in murine models of septic shock. Recent in vitro studies with alveolar macrophages or monocytes show that induction of the stress response in these cells is followed by a decreased liberation of major cytokines [tumor necrosis factor-alpha (TNF alpha) and interleukin-1 (IL-1)] after endotoxin challenge. These findings suggest that the increased resistance to endotoxin in vivo after stress protein induction could be explained by an altered pattern of inflammatory mediator release. Therefore, we measured the time course of thromboxane-B2 (TxB2), 6-keto-PGF1 alpha, platelet activating factor (PAF), TNF alpha, interleukin-1 beta (IL-1 beta), and interleukin-6 (IL-6) formation with and without induction of the stress response in an established porcine model of recurrent endotoxemia (Klosterhalfen et al., Biochem Pharmacol 43: 2103-2109, 1992). Induction of the stress response was done by a pretreatment with Zn2+ (25 mg/kg zinc-bis-(DL-hydrogenasparate = 5 mg/kg Zn2+). Pretreatment with Zn2+ prior to lipopolysaccharide (LPS) infusion induced an increased heat shock protein 70 and metallothionein expression in the lungs, liver, and kidneys and increased plasma levels of TNF alpha, IL-1 beta, IL-6, and TxB2 as opposed to untreated controls. After LPS infusion, however, pretreated animals showed significantly decreased peak plasma levels of all mediators as opposed to the untreated group. The time course of mediator release was identical with the decreasing and increasing three peak profiles described previously. Hemodynamic data presented significantly decreased peak pulmonary artery pressures and significantly altered hypodynamic/hyperdynamic cardiac output levels in the pretreated group. In conclusion, the data show that the induction of stress proteins by Zn2+ could be a practicable strategy to prevent sepsis.
Assuntos
Endotoxemia/prevenção & controle , Endotoxemia/fisiopatologia , Proteínas de Choque Térmico HSP70/biossíntese , Mediadores da Inflamação/fisiologia , Metalotioneína/biossíntese , Zinco/farmacologia , 6-Cetoprostaglandina F1 alfa/biossíntese , Animais , Ácido Aspártico/farmacologia , Pressão Sanguínea/efeitos dos fármacos , Débito Cardíaco/efeitos dos fármacos , Modelos Animais de Doenças , Endotoxemia/genética , Expressão Gênica/efeitos dos fármacos , Proteínas de Choque Térmico HSP70/genética , Interleucina-1/biossíntese , Interleucina-6/biossíntese , Rim/efeitos dos fármacos , Rim/metabolismo , Lipopolissacarídeos/toxicidade , Metalotioneína/genética , Fator de Ativação de Plaquetas/biossíntese , Artéria Pulmonar/efeitos dos fármacos , Recidiva , Suínos , Tromboxano B2/biossíntese , Fator de Necrose Tumoral alfa/biossínteseRESUMO
Sertoli-Leydig cell tumors (SLCTs) represent a rare group of sex-cord stromal tumors of the ovary of unknown pathogenesis. We report a SLCT of intermediate differentiation with peritoneal recurrence and lymph node metastasis 12 months after removal, including cytogenetic analysis by comparative genomic hybridization and fluorescence in situ hybridization, which showed trisomy 8 as sole unbalanced karyotypic aberration. Our results provide evidence that a simple numeric chromosomal abnormality in SLCT may be associated with a malignant phenotype and suggest that the molecular pathogenesis of SLCT may be different from ovarian granulosa-stromal cell tumors.
Assuntos
Cromossomos Humanos Par 8 , Metástase Neoplásica/genética , Neoplasias Ovarianas/genética , Tumor de Células de Sertoli-Leydig/genética , Trissomia , Adolescente , Evolução Fatal , Feminino , Humanos , Hibridização in Situ Fluorescente , Cariotipagem , Metástase Linfática , Recidiva Local de Neoplasia , Hibridização de Ácido Nucleico , Neoplasias Ovarianas/patologia , Neoplasias Ovarianas/cirurgia , Peritônio/patologia , Tumor de Células de Sertoli-Leydig/patologia , Tumor de Células de Sertoli-Leydig/cirurgiaRESUMO
Benign metastasizing leiomyoma (BML) is a rare condition, characterized by the occurrence of multiple smooth-muscle nodules, most often located in the lung after previous hysterectomy because of histologically benign appearing leiomyoma. Although the condition resembles a metastatic process, case studies provided evidence that it may be the result of an intravenous leiomyomatosis or an independent and multifocal smooth-muscle proliferation. Comparative genomic hybridization and X-chromosome inactivation analysis were used in a case of BML to determine whether pulmonary and uterine tumors are related one to another. A balanced karyotype, previously reported in leiomyomas and an identical X-chromosome inactivation pattern found in all tumorlets, is most consistent with a monoclonal origin of both uterine and pulmonary tumors and the interpretation that pulmonary lesions are metastatic.
Assuntos
Leiomioma/patologia , Neoplasias Pulmonares/secundário , Neoplasias Uterinas/patologia , Adulto , Feminino , Inativação Gênica , Humanos , Cariotipagem , Leiomioma/genética , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/patologia , Hibridização de Ácido Nucleico , Células Tumorais Cultivadas , Neoplasias Uterinas/genética , Cromossomo X/genéticaRESUMO
The manipulation of stress gene expression by heavy metals provides protection against the lethal effects of endotoxemia in murine models of septic shock. These findings suggest that the increased resistance to endotoxin in vivo after stress protein induction could be explained by an attenuation of hemodynamic alterations and an altered pattern of inflammatory mediator release. Therefore, we measured main hemodynamic variables such as systemic and pulmonary artery pressure, cardiac output, heart rate, central venous pressure, and pulmonary artery wedge pressure, as well as the time-course of thromboxane-B2, 6-keto-PGF1 alpha, and interleukin 6 formation with and without induction of the stress response in an established porcine model of recurrent endotoxemia (Circ Shock 35:237-244, 1991). Induction of the stress response was carried out by a pretreatment with Zn2+ (25 mg/kg zinc-bis-(DL-hydrogenaspartate) = 5 mg/kg Zn2+). Pretreatment with Zn2+ prior to lipopolysaccharide (LPS) infusion induced an increased heat shock protein 70 (HSP70) expression in the lungs, liver, and kidneys and significantly increased plasma levels of interleukin 6, 6-keto-PGF1 alpha, and thromboxane-B2, compared with untreated controls. After LPS infusion, however, pretreated animals showed significantly decreased peak plasma levels of all mediators compared with the untreated group. Hemodynamic data presented significantly decreased peak pulmonary artery pressure and pulmonary vascular resistance index values, significantly increased systemic artery pressure and systemic vascular resistance index values, and significantly altered hypodynamic/hyperdynamic cardiac output levels in the pretreated group. In conclusion, the data show that the induction of HSP70 by Zn2+ attenuates the liberation of inflammatory mediators, as well as the course of hemodynamic variables due to LPS.
Assuntos
Proteínas de Choque Térmico HSP70/biossíntese , Hemodinâmica/efeitos dos fármacos , Choque Séptico/metabolismo , Zinco/farmacologia , 6-Cetoprostaglandina F1 alfa/sangue , Animais , Modelos Animais de Doenças , Interleucina-6/sangue , Lipopolissacarídeos/farmacologia , Suínos , Tromboxano B2/sangueRESUMO
AIMS: Cytogenetic data on solitary fibrous tumours (SFT) are very limited. We studied a benign pleural SFT for its ultrastructural and immunohistochemical details, and made cytogenetic analyses for comparison with other genetic and ultrastructural studies of SFT. RESULTS: Immunohistochemistry showed strong positivities for CD34 and vimentin, but no reactions with anti-cytokeratins and epithelial membrane antigens. Electron microscopy revealed primitive desmosomes in our SFT. The results thus evinced fibroblast-like cells with intermediate epithelial-mesenchymal character. Comparative genomic hybridization of the tumour revealed losses of 1p33-->pter, 17pter q21, entire copies of chromosomes 19 and 22, and gains of 1p21-p22, 2q23-q32.3, 3pl2-q13.2, 4p14-q28, 6p12-q21, 9p21-->pter and 13q21-q31. Furthermore, there was loss of 20q, as was previously reported elsewhere in a case of benign and a case of malignant SFT. CONCLUSIONS: The results furnish further evidence of the involvement of -20q in SFT. In addition, they show that SFT may have complex genomic imbalances and primitive features, despite having a benign appearance.
Assuntos
Deleção Cromossômica , Cromossomos Humanos Par 20/genética , Neoplasias de Tecido Fibroso/genética , Neoplasias Pleurais/genética , Desmossomos/ultraestrutura , Epitélio , Feminino , Humanos , Cariotipagem , Pessoa de Meia-Idade , Neoplasias de Tecido Fibroso/patologia , Neoplasias Pleurais/patologiaRESUMO
Adenomyomas of the stomach are rare tumours characterised by duct/gland-like structures embedded within a smooth muscle stroma. Although the histogenesis of adenomyomas remains unclear, the histological appearance has justified the assumption that these are abortive forms of pancreatic heterotopia. We report an unusual case with simultaneous and independent appearance of both adenomyoma and pancreatic heterotopia of the stomach including immunohistochemical characterisation, supporting the concept of a common histiogenetic origin of both lesions.
Assuntos
Adenomioma/patologia , Coristoma/patologia , Pâncreas , Neoplasias Gástricas/patologia , Adenomioma/complicações , Adenomioma/metabolismo , Biomarcadores Tumorais/metabolismo , Coristoma/complicações , Coristoma/metabolismo , Humanos , Técnicas Imunoenzimáticas , Masculino , Pessoa de Meia-Idade , Proteínas de Neoplasias/metabolismo , Neoplasias Gástricas/complicações , Neoplasias Gástricas/metabolismoRESUMO
Human papillomavirus (HPV) infection is common in cervical intraepithelial neoplasia (CIN). This study investigates HPV detection and typing assay based on polymerase chain reaction amplification of L1 open reading frame with general primers GP5/GP6, followed by enzyme-linked immunosorbent assay detection with type-specific DNA probes. To determine the sensitivity of this assay, formalin-fixed CaSki cells were used as reference cell lines. Fifty copies of viral DNA diluted in DNA from 100,000 noninfected cells could be detected. This assay was also investigated for HPV detection and typing of 67 cervical specimens diagnosed with with CIN III or carcinoma in situ (CIS) and their adjacent squamous epithelium. The CIN III lesions were infected in approximately 80% of the samples, 81% in the neighboring CIN II, and 68% in CIN I. The HPV infection was even detectable in 54% of nondysplastic epithelium located near a CIN III lesion.
Assuntos
Papillomaviridae/genética , Infecções por Papillomavirus/diagnóstico , Infecções Tumorais por Vírus/diagnóstico , Displasia do Colo do Útero/induzido quimicamente , Neoplasias do Colo do Útero/diagnóstico , Sequência de Bases , Primers do DNA/química , DNA Viral/análise , Ensaio de Imunoadsorção Enzimática/métodos , Feminino , Células HeLa/virologia , Humanos , Dados de Sequência Molecular , Papillomaviridae/classificação , Infecções por Papillomavirus/virologia , Reação em Cadeia da Polimerase/métodos , Sensibilidade e Especificidade , Células Tumorais Cultivadas , Infecções Tumorais por Vírus/virologia , Neoplasias do Colo do Útero/virologia , Esfregaço Vaginal/métodos , Displasia do Colo do Útero/virologiaRESUMO
Reaction of estrone methyl ether 1 with sodium hydride and 1,3-dibromopropane, 1,4-dibromobutane, and 1,5-dibromopentane, respectively, gives the 16-spirosteroid derivatives 2-4, which were reduced to the 17 beta-alcohols 7-9. Acetylation afforded the acetates 10-12. In the reaction of 1 and 1,3-dibromopropane a bis-allyl compound 5 and an annulated dihydropyran 6 were also formed. Cleavage of the ether moiety in 2 and 3 was accomplished with diisobutylaluminum hydride to give 3,17 beta-diols 13 and 14, respectively.
Assuntos
Estrona/análogos & derivados , Estrona/química , Compostos de Espiro/síntese química , Acetilação , Cristalização , Furanos , Hidrocarbonetos Bromados , Espectroscopia de Ressonância Magnética , Estrutura Molecular , Pentanos , Propano/análogos & derivados , Espectrofotometria Infravermelho , EstereoisomerismoRESUMO
The reaction of methyl 2,3,4,6-tetra-O-acetyl-1-O-trimethylsilyl-beta- and -alpha-D-glucopyranuronate severally with the dimethyl or diethyl acetals of formaldehyde, bromoacetaldehyde, propionaldehyde, 3-benzyloxypropionaldehyde, 5-carboxypentanal, and 2-bromohexanal in the presence of catalytic amounts of trimethylsilyl trifluoromethanesulfonate at -78 degrees gave the corresponding (1-alkoxyalkyl) alpha- and beta-glycosides (acetal-glucopyranosiduronates) with retention of configuration at C-1 in yields of 41-91%. Instead of the dialkyl acetals, the corresponding aldehydes and alkyl trimethylsilyl ether can be used. Deacetylation gave the corresponding methyl (acetal-beta- and -alpha-D-glucopyranosid)uronates in good yield. De-esterification of methyl [(1R)-1-methoxybutyl beta-D-glucopyranosid]uronate with esterase gave the acetal-beta-D-glucopyranosiduronic acid which was an excellent substrate for beta-D-glucuronidase.
Assuntos
Antineoplásicos/síntese química , Glucuronatos/síntese química , Glucuronatos/farmacologia , Estrutura Molecular , Pró-Fármacos/síntese química , EstereoisomerismoRESUMO
The synthesis is described of highly acid-sensitive, 1,1-dialkyl-1-methoxymethyl glucosides (acetal-glucosides) as potential anti-cancer prodrugs. Reaction of 2,3,4,6-tetra-O-acetyl-1-O-trimethylsilyl-beta-D-glucopyranose (4) severally with various aliphatic and alicyclic ketones and methyl trimethylsilyl ether, in the presence of catalytic amounts of trimethylsilyl trifluoromethanesulfonate, afforded the corresponding acetylated acetal-beta-glucosides, e.g., acetone gave 1-methoxy-1-methylethyl 2,3,4,6-tetra-O-acetyl-beta-D-glucopyranoside (7a). Likewise the alpha-anomer (8a) of 7a was obtained from the alpha-anomer of 4. Deacetylation of the tetra-acetates then gave the acetal-alpha- and -beta-glucosides.
Assuntos
Acetais/síntese química , Glucosídeos/síntese química , Glicosídeos/síntese química , Antineoplásicos/síntese química , Configuração de Carboidratos , Desenho de Fármacos , Indicadores e Reagentes , Rotação Ocular , Pró-Fármacos/síntese química , EstereoisomerismoRESUMO
OBJECTIVE: Bone-anchored hearing aids (BAHAs) are indicated for use in children with bilateral microtia or chronic suppurative otitis media, which precludes the use of conventional hearing aids. METHODS: Nineteen consecutive children using BAHAs were reviewed retrospectively. Outcome measures included the long-term stability of BAHAs, frequency of adverse dermatological reactions at the implant site, and audiologic thresholds. RESULTS: Osseointegration was achieved in 95% of patients. One patient lost the implant fixture secondary to direct head trauma. Site revisions were required for only two patients secondary to soft-tissue overgrowth at the abutment site. There were no differences between pre-implantation and post-implantation bone or air conduction thresholds, but there was a statistical improvement in the post-implantation aided thresholds. CONCLUSIONS: Utilization of paediatric BAHAs, in a distinct population, is a reliable and successful method for audiologic rehabilitation.
Assuntos
Auxiliares de Audição , Perda Auditiva Condutiva/reabilitação , Processo Mastoide/cirurgia , Próteses e Implantes , Adolescente , Audiometria , Criança , Pré-Escolar , Feminino , Seguimentos , Perda Auditiva Condutiva/etiologia , Perda Auditiva Condutiva/cirurgia , Humanos , Masculino , Osseointegração , Otite Média Supurativa/complicações , Estudos Retrospectivos , Sensibilidade e Especificidade , Resultado do TratamentoRESUMO
Diverticulitis of the vermiform appendix is an often disregarded disease. Diagnosis follows after appendectomy due to inflammatory complications in the form of diverticulitis and appendicitis. Diverticula can also be found as a reason for complaints in histologically unaltered appendix or as an incidental finding. Diverticula of the vermiform appendix are classified as false (acquired) or true (congenital). We report on the case of a 57-year-old man with a perforated appendix diverticulum as reason for peritonitis and a paralytic ileus of the colon and small intestine.