RESUMEN
AIM: To study the students' satisfaction with the week-long summer programme and the importance of common influencing factors (IFs) for choosing dentistry as their career. METHODS: Anonymous questionnaire was given to all 214 participants in July of 2011 and 2012. Demographic information including gender, age and education level was collected. The students were asked about their satisfaction with the programme with separate ratings for learning experiences, including hands-on workshops (HOW); clinic observations (CO); problem-based learning tutorials (PBL); and lectures (L). They also rated the relative importance of the ten common IFs. The Friedman test was used to study the order of their preferences of the programme's activities. The Chi-square test was used to study the influence of their demographic factors on the importance of the IFs. RESULTS: A total of 208 students returned their questionnaires. The majority were below the age of 18 (81%), and 44% were studying in an international school. Most of the students (96%) were satisfied with the programme overall. They liked the HOWs and COs more than the PBL tutorials and Ls. 'Altruism' and 'medical/health care career' were the two most important IFs overall. 'Altruism' and 'past experience with dentist' were considered more important by those aged 18 or above. 'Past experience with dentist' and 'working with hands' were considered more important by the international school students. CONCLUSIONS: Most participants were satisfied with the summer programme. They preferred practical, skill-based activities to knowledge-based activities. The importance of some IFs was associated with age and education system.
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Selección de Profesión , Comportamiento del Consumidor , Odontología , Educación Preodontológica , Adolescente , Adulto , Toma de Decisiones , Escolaridad , Femenino , Objetivos , Hong Kong , Humanos , Masculino , Motivación , Encuestas y CuestionariosRESUMEN
Hong Kong, a Special Administrative Region of People's Republic of China, is a metropolitan city in Asia with a population of over 7 million people. This paper reflects the current oral health and dental care situations in Hong Kong. Water fluoridation was commenced in 1961, with a current level at 0.5 ppm. And there has continuously been lower caries prevalence thereafter. Dental care is mainly provided by private practitioners. The School Dental Care Service, run by the Department of Health, provides dental care to enrolled primary school children through treatments by dental therapists. An Oral Health Education Unit is set up to promote dental health among the public, particularly preschool children. Government dentists serve mainly civil servants and their dependents. Limited emergency dental care is available to the public at designated government clinics for pain relief, most commonly in the form of extractions. There are about 2200 registered dentists and the dentist to population ratio is about 1:3200. Amongst the dental team, dental hygienists are trained in limited numbers. There are only less than 320 dental hygienists registered, working under the supervision of dentists. The Faculty of Dentistry of the University of Hong Kong has been providing 5-year undergraduate training in dentistry since 1981, and this is lengthened to 6 years from 2012 onwards. Specialty training requires at least a further 6 years. There are 8 specialties, which are Community Dentistry, Endodontics, Family Dentistry, Oral & Maxillofacial Surgery, Oral Rehabilitation, Orthodontics, Pediatric Dentistry, and Periodontics.
Asunto(s)
Atención Odontológica , Salud Bucal , Enfermedades Dentales/prevención & control , Hong Kong/epidemiología , Humanos , Morbilidad/tendencias , Enfermedades Dentales/epidemiologíaRESUMEN
B-cell chronic lymphocytic leukemia (B-CLL) is a hematologic malignancy characterized by the proliferation and accumulation of mature-looking B lymphocytes. Patients with B-CLL exhibit a number of immune defects including: auto-antibodies, depressed cell-mediated immunity and hypogammaglobulinemia (HG). We investigated the control of Ig production in the malignant CLL B-cell at a transcriptional and translation level. We isolated fresh leukemic B-cells from CLL patients and analyzed for the presence of nuclear factors OCT-1, OCT-2, and NF-KB. Malignant B-cells were purified to greater than 90% B-cells, and total cellular RNA and nuclear proteins were isolated from these cells. Mobility shift assays were probed with 32P-labeled oligonucleotides specific to the immunoglobulin (Ig) enhancer and promotor regions. We detected endogenous OCT-1, OCT-2, and NF-KB in all patients tested (n = 5). We then evaluated whether activation of CLL B cells could augment kappa-mRNA levels. CLL cells (n = 3) exposed to phorbol ester and A23187 were harvested at 0, 2, 4, 8, and 48 min and examined for kappa-mRNA by Northern blot. All CLL patients (n = 3) had easily detectable levels of endogenous kappa-mRNA. However, only one patient had an obvious increase in kappa-mRNA post-induction with TPA/A23187. There was no concomitant increase in this patient's OCT-1, OCT-2, or NF-KB level. This finding prompted us to survey other B-CLL patients (n = 6) for Ig nuclear transcriptional factors pre- and post-induction. In summary, CLL B cells express Ig transcriptional factor OCT-1, OCT-2, and NF-KB constitutively. The endogenous level of NF-KB may account for the basal kappa-mRNA detected in B-CLL cells. However, the inability to augment NF-KB levels may, in part, explain the low levels of Ig synthesis in CLL B-cells.
Asunto(s)
Genes de Inmunoglobulinas , Cadenas kappa de Inmunoglobulina/genética , Leucemia Linfocítica Crónica de Células B/genética , Factores de Transcripción/metabolismo , Secuencia de Bases , Calcimicina/farmacología , Núcleo Celular/metabolismo , Proteínas de Unión al ADN/metabolismo , Regulación Neoplásica de la Expresión Génica , Humanos , Técnicas In Vitro , Datos de Secuencia Molecular , FN-kappa B/metabolismo , Factor 2 de Transcripción de Unión a Octámeros , Oligodesoxirribonucleótidos/química , ARN Mensajero/genética , ARN Neoplásico/genética , Activación Transcripcional , Células Tumorales CultivadasRESUMEN
BACKGROUND: Salvage therapies after initial Helicobacter pylori eradication failure of ranitidine bismuth citrate (RBC)-based regimens remain undefined. AIM: To test the efficacy of 1-week omeprazole, amoxycillin and clarithromycin as a second-line treatment and 1-week quadruple therapy after repeated failures of RBC- and proton pump inhibitor-based regimens. METHOD: Patients were recruited from a recently published prospective randomized study if confirmed to have failed H. pylori eradication with RBC-based regimens. They were given omeprazole 20 mg, amoxycillin 1 g and clarithromycin 500 mg (OAC) b.d. for 1 week. 13C-urea breath test was performed 4 weeks after the conclusion of medication. Those who failed to respond to OAC were given 1-week quadruple therapy (bismuth subcitrate 120 mg, tetracycline 500 mg and metronidazole 400 mg q.d.s. plus omeprazole 20 mg b.d.). RESULTS: Among 398 patients receiving RBC-based therapies, 40 (10%) had failed eradication (RAC=7, RC-2=12, RMC=7, and RMT=14). OAC was prescribed to 31 patients (RAC=4, RC-2=9, RMC=6, and RMT=12) and 68% had successful eradication. Nine out of 10 patients with failed second treatment received quadruple therapy; successful eradication occurred in 83% (5 out of 6) after repeated failures of clarithromycin-based regimens. CONCLUSION: One-week OAC is not an optimal second-line therapy when RBC-clarithromycin combinations fail. Quadruple therapy appears to be effective despite repeated failures of clarithromycin-based RBC or proton pump inhibitor therapies.
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Antiulcerosos/uso terapéutico , Bismuto/uso terapéutico , Infecciones por Helicobacter/tratamiento farmacológico , Helicobacter pylori , Ranitidina/análogos & derivados , Terapia Recuperativa , Amoxicilina/uso terapéutico , Antibacterianos/uso terapéutico , Claritromicina/uso terapéutico , Inhibidores Enzimáticos/uso terapéutico , Infecciones por Helicobacter/microbiología , Humanos , Omeprazol/uso terapéutico , Penicilinas/uso terapéutico , Estudios Prospectivos , Inhibidores de la Bomba de Protones , Ranitidina/uso terapéuticoRESUMEN
BACKGROUND: We have previously shown that ranitidine bismuth citrate (RBC)-based triple therapy is comparable to proton pump inhibitor-based triple therapy in eradicating Helicobacter pylori infection. AIM: To test the efficacy of different combinations of antimicrobials with RBC in the treatment of H. pylori infection. METHODS: Dyspeptic patients with H. pylori infection were prospectively randomized to receive one of the following regimens: (i) RBC 400 mg, amoxycillin 1 g, clarithromycin 500 mg [RAC]; (ii) RBC 400 mg, metronidazole 400 mg, clarithromycin 500 mg [RMC]; (iii) RBC 400 mg, metronidazole 400 mg, tetracycline 1 g [RMT] (all given twice daily for 1 week); or (iv) RBC 400 mg plus clarithromycin 500 mg twice daily for 2 weeks [RC-2]. Endoscopy (rapid urease test and culture) and 13C-urea breath test (UBT) were performed before randomization. Four weeks after finishing medication, the 13C-UBT was repeated in all cases and endoscopy was offered to patients with peptic ulcers. RESULTS: Four hundred patients were randomized but in two (one in the RAC group and one in the RMC group) H. pylori infection was not confirmed. Successful eradication of H. pylori (intention-to-treat analysis and 95% CI) of RAC (86% [79-93%]), RMC (90% [84-96%]), RMT (79% [71-87%]) and RC-2 (82% [75-90%]) were comparable, with a trend favouring clarithromycin-containing triple therapy regimens. Among 276 isolates tested for antibiotic sensitivity, primary resistance to metronidazole, clarithromycin and amoxycillin was found in 56%, 2% and 0.4%, respectively. When given RMC or RMT, patients infected by metronidazole-resistant H. pylori had success in eradicating H. pylori similar to patients infected by metronidazole-sensitive H. pylori. CONCLUSION: One-week RBC triple therapy is effective in curing H. pylori infection.
Asunto(s)
Amoxicilina/uso terapéutico , Antibacterianos/uso terapéutico , Antiulcerosos/uso terapéutico , Bismuto/uso terapéutico , Claritromicina/uso terapéutico , Infecciones por Helicobacter/tratamiento farmacológico , Helicobacter pylori , Metronidazol/uso terapéutico , Penicilinas/uso terapéutico , Ranitidina/análogos & derivados , Adolescente , Adulto , Anciano , Método Doble Ciego , Combinación de Medicamentos , Dispepsia/tratamiento farmacológico , Dispepsia/etiología , Femenino , Infecciones por Helicobacter/microbiología , Helicobacter pylori/efectos de los fármacos , Humanos , Masculino , Pruebas de Sensibilidad Microbiana , Persona de Mediana Edad , Úlcera Péptica/tratamiento farmacológico , Úlcera Péptica/microbiología , Estudios Prospectivos , Ranitidina/uso terapéutico , Resultado del TratamientoRESUMEN
BACKGROUND: Despite the widely accepted view that Helicobacter pylori is the most important cause of peptic ulcer disease, recent studies have suggested that the microbe protects against nonsteroidal anti-inflammatory drug (NSAID)-associated gastroduodenal lesions and promotes ulcer healing. We investigated the effects of H. pylori eradication on the healing of NSAID-associated bleeding peptic ulcers. METHODS: Chronic NSAID users presenting with peptic ulcer haemorrhage underwent endoscopy to secure haemostasis and to document H. pylori infection by rapid urease test and culture. They were prospectively randomized to receive either omeprazole (20 mg once daily) for 8 weeks or a 1-week course of triple therapy (bismuth subcitrate 120 mg, tetracycline 500 mg, metronidazole 400 mg, all given four times daily) plus omeprazole (20 mg once daily) for 8 weeks. Endoscopy was repeated after 8 weeks. Final H. pylori status was determined by a 13C-urea breath test that was performed at least 4 weeks after discontinuation of omeprazole. RESULTS: 195 H. pylori-infected NSAID users, complicated by bleeding ulcers, were randomized to receive omeprazole alone (102) or triple therapy plus omeprazole (93). 174 patients returned for second endoscopy at 8 weeks (91 in the omeprazole group, 83 in the triple therapy group). Urea breath test was negative in 14% in the omeprazole group vs. 92% in the triple therapy group (P < 0.001). Complete ulcer healing was achieved in 88 (97%) patients in the omeprazole group and 77 (93%) in the triple therapy group (P=0. 31). On intention-to-treat analysis, ulcers were healed in 86% of the omeprazole group and 83% of the triple therapy group (P=0.50). There was no significant difference in the healing rates of gastric or duodenal ulcers between the two groups. CONCLUSION: Eradication of H. pylori did not impair the healing of NSAID-associated bleeding peptic ulcers.
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Antiinflamatorios no Esteroideos/efectos adversos , Antiulcerosos/uso terapéutico , Quimioterapia Combinada/uso terapéutico , Infecciones por Helicobacter/tratamiento farmacológico , Helicobacter pylori/fisiología , Omeprazol/uso terapéutico , Úlcera Péptica Hemorrágica/tratamiento farmacológico , Adulto , Anciano , Femenino , Humanos , Masculino , Metronidazol/uso terapéutico , Persona de Mediana Edad , Compuestos Organometálicos/uso terapéutico , Tetraciclina/uso terapéuticoRESUMEN
We previously described the purification of a membrane-bound diacylglycerol kinase highly selective for sn-1-acyl-2-arachidonoyl diacylglycerols (Walsh, J. P., Suen, R., Lemaitre, R. N., and Glomset, J. A. (1994) J. Biol. Chem. 269, 21155-21164). This enzyme appears to be responsible for the rapid clearance of the arachidonate-rich pool of diacylglycerols generated during stimulus-induced phosphoinositide turnover. We have now shown phosphatidylinositol 4,5-bisphosphate to be a potent and specific inhibitor of arachidonoyl-diacylglycerol kinase. Kinetic analyses indicated a Ki for phosphatidylinositol 4,5-bisphosphate of 0.04 mol %. Phosphatidic acid also was an inhibitor with a Ki of 0.7 mol %. Other phospholipids had only small effects at these concentrations. A series of multiply phosphorylated lipid analogs also inhibited the enzyme, indicating that the head group phosphomonoesters are the primary determinants of the polyphosphoinositide effect. However, these compounds were not as potent as phosphatidylinositol 4,5-bisphosphate, indicating some specificity for the polyphosphoinositide additional to its total charge. Five other diacylglycerol kinases were activated to varying degrees by phosphatidylinositol 4,5-bisphosphate and phosphatidic acid, suggesting that inhibition by acidic lipids may be specific for the arachidonoyl-DAG kinase isoform. Given the presumed role of arachidonoyl-diacylglycerol kinase in the phosphoinositide cycle, this inhibition may represent a mechanism for polyphosphoinositides to regulate their own synthesis.
Asunto(s)
Fosfatos de Fosfatidilinositol/farmacología , Fosfatidilinositoles/biosíntesis , Fosfotransferasas (Aceptor de Grupo Alcohol)/antagonistas & inhibidores , Células 3T3 , Animales , Diacilglicerol Quinasa , Concentración de Iones de Hidrógeno , Ratones , Ácidos Fosfatidicos/farmacología , Ácidos Fosfatidicos/fisiología , Fosfatidilinositol 4,5-Difosfato , Fosfatos de Fosfatidilinositol/fisiología , Fosforilación , Fosfotransferasas (Aceptor de Grupo Alcohol)/metabolismoRESUMEN
Sequential alterations in 5-fluorouracil-treated hamster fetal palate were studied by light and electron microscopy and by acid phosphatase cytochemistry. At an early stage in 5-fluorouracil-treated fetuses, when the palatal shelves were vertical, lysosomes first appeared in cells of the prospective fusion epithelium and then in the cells of subjacent mesenchyme. In contrast to controls, increasing numbers of both the epithelial and mesenchymal cells of the vertical palate showed lysosomal injury in 5-fluorouracil-treated fetuses as development progressed. Subsequently, the basal lamina in the vertical palate showed alterations, characterized initially by disturbances in lamina lucida, by fingerlike extensions of lamina densa, and ultimately by its complete breakdown. At a later stage, when shelves became horizontal, the lysosomes were absent in both the epithelial and mesenchymal cells, and the basal lamina continuity was restored. Unlike controls, however, 5-fluorouracil-treated horizontal shelves never contacted one another. Instead, the epithelia of the horizontal shelves underwent stratification. It appears that premature formation of lysosomes in palatal epithelial and mesenchymal cells following 5-fluorouracil treatment disrupts normal cytodifferentiation and affects the integrity of the basal lamina; both effects are associated with cleft-palate development.
Asunto(s)
Fisura del Paladar/embriología , Fosfatasa Ácida/metabolismo , Animales , Fisura del Paladar/inducido químicamente , Fisura del Paladar/enzimología , Cricetinae , Fluorouracilo , Histocitoquímica , Mesocricetus , Microscopía Electrónica , Hueso Paladar/enzimología , Hueso Paladar/ultraestructuraRESUMEN
In 70 B-CLL patients, deletion or translocation, at or near the retinoblastoma (Rb) site, was detected in 20 by cytogenetic analysis. Purified B cell clones from 13 of these B-CLL patients were isolated and studied for Rb gene status, Rb mRNA and the Rb protein product. Southern blot analysis of the Rb site detected internal deletions (N = 1) or a single allele loss (N = 2) in five patients. Northern blots detected reduced Rb mRNA in four patients. Immunoblot of whole cell lysate revealed reduced levels of unphosphorylated Rb protein in six CLL patients. No CLL B cell clone contained phosphorylated Rb species. These molecular studies have confirmed the cytogenetic alteration of 13q12-14 sites in B-CLL cells. In addition, cytogenetic and molecular biologic analysis suggest heterogeneity in the B cell clone for Rb gene abnormality. B-CLL patients with abnormalities in both cytogenetic and Rb DNA/RNA analysis will have a dominance of B cells with an Rb abnormality (N = 5). In patients whose Rb defective CLL cells constitute only a minor subpopulation of the total B cell clone, only cytogenetic defects would likely be detected (N = 7).
Asunto(s)
Eliminación de Gen , Genes de Retinoblastoma/genética , Leucemia Linfocítica Crónica de Células B/genética , Translocación Genética , Northern Blotting , Southern Blotting , Western Blotting , Células Clonales , Humanos , ARN Mensajero/análisis , Proteína de Retinoblastoma/análisisRESUMEN
Cyclophosphamide (CP), when injected in hamster mother between days 9 and 11 of pregnancy, was teratogenic in fetuses. On the basis of a morphological study it was deduced that CP delayed the reorientation of hamster palatal shelves by 16-20 h. In a subsequent experiment, in both control and CP-treated palatal shelves, the numbers of epithelial and mesenchymal cells were counted and cross-sectional area was measured. DNA synthesis, measured by 3H-thymidine incorporation, was used as an index of growth by cell proliferation. The results showed that during the vertical development of palatal shelves, the mesenchymal cells reached their peak number during the initial 24 hours, i.e., at the end of the second peak in DNA synthesis, and remained unchanged thereafter throughout reorientation. The shelf area also showed rapid increase during the initial 24 h followed by a spurt 2 h prior to reorientation. Cyclophosphamide prolonged the acquisition of these features by affecting the mesenchymal cells and consequently delayed the reorientation of the vertical shelves until such time that the number of healthy mesenchymal cells and shelf area were restored to the control values. The data lend further support to the hypothesis that the acquisition of a specific number of cells and shelf volume, during vertical palatal development, may be essential for palatal shelf reorientation.
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Ciclofosfamida/toxicidad , Intercambio Materno-Fetal , Hueso Paladar/efectos de los fármacos , Anomalías Inducidas por Medicamentos , Animales , Cricetinae , Relación Dosis-Respuesta a Droga , Femenino , Edad Gestacional , Inyecciones Intraperitoneales , Mesocricetus , Mesodermo/efectos de los fármacos , Morfogénesis/efectos de los fármacos , Hueso Paladar/embriología , EmbarazoRESUMEN
Previous work in our laboratory demonstrated the existence of a membrane-bound diacylglycerol kinase highly selective for diacylglycerols containing arachidonate as the sn-2 fatty acyl moiety (MacDonald, M. L., Mack K. F., Richardson, C. N., and Glomset, J. A. (1988) J. Biol. Chem. 263, 1575-1583). We now report the purification of arachidonoyl-diacylglycerol kinase 34,400-fold to apparent homogeneity from bovine testis. High concentrations of both salt and detergent were required to extract the enzyme from membranes and stabilize its activity, suggesting that in vivo the enzyme is part of a complex with other membrane or cytoskeletal proteins. Arachidonoyl-diacylglycerol kinase had an apparent M(r) of 58,000 both on SDS-polyacrylamide gels and by size exclusion chromatography. The enzyme appeared to be an integral membrane protein. In a mixed micellar assay, arachidonoyl-diacylglycerol kinase followed surface dilution kinetics with respect to diacylglycerol. The purified enzyme retained the arachidonate selectivity observed previously in membranes. Kinetic analyses indicated a Km for sn-1-stearoyl-2-arachidonoylglycerol of 2.4 mol %, as compared to 43 mol % for sn-1-palmitoyl-2-oleoylglycerol. Calcium, an activator of some other diacylglycerol kinases, had no apparent effect on the arachidonate-specific enzyme. Guanosine triphosphate could effectively substitute for ATP as the phosphoryl donor and Mg2+ could be replaced by Mn2+ or Ca2+. Phosphatidylserine and, to a lesser extent, phosphatidylinositol inhibited the purified enzyme. Phosphatidylcholine and phosphatidylethanolamine had only small effects.
Asunto(s)
Fosfotransferasas (Aceptor de Grupo Alcohol)/aislamiento & purificación , Testículo/enzimología , Células 3T3 , Adenosina Trifosfato/metabolismo , Animales , Cationes Bivalentes , Bovinos , Cromatografía en Gel , Cromatografía por Intercambio Iónico , Diacilglicerol Quinasa , Diglicéridos/metabolismo , Electroforesis en Gel de Poliacrilamida , Concentración de Iones de Hidrógeno , Cinética , Masculino , Proteínas de la Membrana/aislamiento & purificación , Proteínas de la Membrana/metabolismo , Ratones , Peso Molecular , Fosfolípidos/farmacología , Fosfotransferasas (Aceptor de Grupo Alcohol)/metabolismo , Distribución TisularRESUMEN
Consecutive Chinese patients undergoing endoscopy for dyspepsia were tested for Helicobacter pylori infection by two rapid whole-blood tests: FlexPack HP (Abbott Laboratories) and Helisal One-Step (Cortecs Diagnostics). Biopsy-based tests (rapid urease test and histology) and the [13C]urea breath test were used as the "gold standard." One hundred sixty-one consecutive patients were studied, and 88 (54.7%) were confirmed to have H. pylori infection. The sensitivities, specificities, and positive and negative predictive values were 81.8%, 83.6% (P = 0.008), 85.7% (P = 0.04), and 79.2% for FlexPack HP and 84.1%, 63.0% (P = 0.008), 73.3% (P = 0.047), and 76.7% for Helisal One-Step, respectively.
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Bacteriemia/diagnóstico , Técnicas Bacteriológicas , Infecciones por Helicobacter/diagnóstico , Helicobacter pylori/aislamiento & purificación , Adulto , Anciano , Anciano de 80 o más Años , Bacteriemia/metabolismo , Bacteriemia/microbiología , Técnicas Bacteriológicas/estadística & datos numéricos , China , Estudios de Evaluación como Asunto , Femenino , Infecciones por Helicobacter/metabolismo , Infecciones por Helicobacter/microbiología , Helicobacter pylori/metabolismo , Humanos , Masculino , Persona de Mediana Edad , Valor Predictivo de las Pruebas , Sensibilidad y Especificidad , Urea/metabolismo , Ureasa/metabolismoRESUMEN
Embryonic development of the secondary palate of the Japanese quail, Coturnix coturnix japonica, was studied. The palatal shelves appeared on day 5 of incubation in a horizontal direction over the dorsal surface of the tongue. Subsequently, unlike those in mammals, the opposing palatal shelves do not fuse, and a physiological cleft persists between them. In comparison with the chick, where the palatal shelves do not fuse and the medial edge epithelium (MEE) becomes orthokeratinized stratified squamous type, the quail MEE differentiates into a parakeratinized stratified squamous type. The basal cells of the quail MEE differentiated from cuboidal to columnar and showed reorganization of their cytoplasmic organelles. In contrast to both the chick and mammalian MEE, quail MEE showed very little ruthenium red (RR) binding at the plasma membrane of both the basal and superficial cells. Initial development in a horizontal direction, lack of fusion, and an absence of programmed cell death in MEE of developing quail palate distinguished it from the mammalian palatogenesis. Also, although the morphogenesis of palate in quail and chick was similar, the pattern of cytodifferentiation in their MEE was different, which may be attributed to their ontogenesis.
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Coturnix/embriología , Hueso Paladar/embriología , Codorniz/embriología , Animales , Membrana Basal/ultraestructura , Diferenciación Celular , Epitelio/ultraestructura , Microscopía Electrónica , Organoides/ultraestructura , Hueso Paladar/ultraestructura , Reacción del Ácido Peryódico de Schiff , Coloración y EtiquetadoRESUMEN
A series of experiments were undertaken to compare the in vitro behaviour of the medial edge epithelium (MEE) of hamster, in which palatal shelves normally fuse, and chick, in which they do not fuse. Homotypic pairs of hamster and chick embryo palatal processes, single palatal processes, and heterotypic palatal shelves of both animals were grown in vitro. The results indicated that contact between palatal shelves may not be crucial for MEE differentiation in mammals. The ability to acquire pre-fusion characteristics may be present in mammalian palatal tissue from their early development and may be expressed by cessation of DNA synthesis in the MEE, elevation of cAMP, and MEE cell death. Isolated chick palatal shelf cultured under identical conditions did not express these mammalian pre-fusion characteristics. When MEE of hamster and chick palatal shelves were placed in contact with one another, the intervening epithelia underwent cytolysis. This could be due to either the destruction of chick MEE by lysosomal enzymes liberated from adjacent degenerating hamster MEE cells, or by induction of cell death in chick MEE by hamster mesenchyme. Heterotypic palatal tissue combinations also suggest that release of lysosomal enzymes in the hamster MEE, which leads to its dissolution, may be the terminal event in epithelial differentiation prior to the establishment of mesenchymal continuity. It is suggested that an inverse relationship exists between DNA synthesis and cAMP levels during palatogenesis: when palate closes (as in mammals) the MEE is eliminated by increasing cAMP levels, whereas when palate remains open (as in birds) low level of cAMP preserve the integrity of MEE by supporting DNA synthesis.
Asunto(s)
Hueso Paladar/embriología , Animales , Embrión de Pollo , Cricetinae , Técnicas de Cultivo , Mesocricetus , Hueso Paladar/anatomía & histologíaRESUMEN
BACKGROUND: Patients with hepatocellular carcinoma complicated by variceal bleeding have a very limited life span. Recurrent bleeding after endoscopic injection sclerotherapy is common. Our aim was to compare the efficacy of endoscopic injection of cyanoacrylate versus sodium tetradecyl sulphate in the control of variceal bleeding in patients with hepatocellular carcinoma. METHODS: Patients known to be suffering from inoperable hepatocellular carcinoma who presented with upper gastrointestinal bleeding underwent endoscopy within 24 hours of admission. After bleeding from esophageal varices was confirmed, they were randomized to receive endoscopic injections of either cyanoacrylate (1:1 mixture with Lipoidol) or sodium tetradecyl sulphate (1.5%). Injection were given intravariceally into each visible column for up to four injections for cyanoacrylate and up to 30 mL for sodium tetradecyl sulphate. RESULTS: A total of 50 patients were recruited for this study with 25 cases randomized to each endoscopic treatment group. Control of acute bleeding failed in four patients (16%) in both treatment groups, and two patients in each group died during the index episode of bleeding. Six patients (24%) in the cyanoacrylate group and four patients (16%) in the sodium tetradecyl sulphate group developed recurrent bleeding during their hospital stay (p = 0.48). Recurrent bleeding within 30 days after the index episode of bleeding was documented in seven patients (28%) who received cyanoacrylate injection and five patients (20%) who received sodium tetradecyl sulphate injection (p = 0.51). Median survival in the cyanoacrylate group was 16 days (range 1 to 485 days) and that of the sodium tetradecyl sulphate group was 13 days (range 1 to 407 days). There was no difference in cumulative survival between the two groups as analyzed by the Kaplan-Meier method. Patients with portal vein thrombosis had a higher risk of recurrent hemorrhage. Patients with Child's C liver disease had a significantly higher mortality. CONCLUSIONS: Cyanoacrylate did not improve the outcome of hepatocellular carcinoma patients with variceal hemorrhage.
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Carcinoma Hepatocelular/complicaciones , Cianoacrilatos/uso terapéutico , Várices Esofágicas y Gástricas/terapia , Hemorragia Gastrointestinal/terapia , Hemostasis Endoscópica , Neoplasias Hepáticas/complicaciones , Soluciones Esclerosantes/uso terapéutico , Tetradecil Sulfato de Sodio/uso terapéutico , Carcinoma Hepatocelular/mortalidad , Várices Esofágicas y Gástricas/etiología , Várices Esofágicas y Gástricas/mortalidad , Femenino , Hemorragia Gastrointestinal/etiología , Hemorragia Gastrointestinal/mortalidad , Humanos , Neoplasias Hepáticas/mortalidad , Masculino , Persona de Mediana Edad , Vena Porta , Pronóstico , Estudios Prospectivos , Recurrencia , Escleroterapia/métodos , Tasa de Supervivencia , Trombosis/epidemiologíaRESUMEN
One hundred consecutive patients with acute suppurative cholangitis were randomized in a prospective, controlled clinical trial to receive either ciprofloxacin (200 mg bd iv) or triple therapy comprising ceftazidime (1 g bd iv), ampicillin (500 mg qds iv) and metronidazole (500 mg tds iv); 46 and 44 patients in the ciprofloxacin and triple therapy groups respectively were suitable for inclusion in the analysis of efficacy. In two-thirds of the patients biliary obstruction was caused by ductal calculi and in one-third by malignant or benign strictures of the biliary tract. Bacteraemia was documented in 38% of patients in the ciprofloxacin group and in 34% of patients in the triple therapy group, while bile cultures were positive in 87% and 92% of patients in the ciprofloxacin and triple therapy groups respectively. Escherichia coli, Klebsiella spp. and Enterococcus spp. were the most common biliary isolates. Eighty-five per cent of evaluable patients in the ciprofloxacin group and 77% of those in the triple therapy group responded to therapy. The mean durations of fever, septicaemic shock and hospitalization were also similar in the two treatment groups. Six (13%) patients in the ciprofloxacin group and seven (16%) in the triple therapy group required urgent endoscopy or surgery for uncontrolled infection. Recurrence of fever after an initial response was documented in one (2%) patient receiving ciprofloxacin and in three (7%) patients receiving triple therapy. The incidences of mortality were 4% in the ciprofloxacin group and 2% in the triple therapy group. The results of this study suggest that ciprofloxacin alone is adequate empirical therapy for patients with cholangitis.
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Colangitis/tratamiento farmacológico , Ciprofloxacina/uso terapéutico , Enfermedad Aguda , Anciano , Bacterias/efectos de los fármacos , Bilis/microbiología , Sistema Biliar/fisiología , Colangitis/microbiología , Ciprofloxacina/administración & dosificación , Ciprofloxacina/efectos adversos , Método Doble Ciego , Drenaje , Femenino , Humanos , Inyecciones Intravenosas , Masculino , Pruebas de Sensibilidad Microbiana , Estudios ProspectivosRESUMEN
The objective was to study the gastrointestinal complications in chronic NSAID users with Helicobacter pylori infection. Eighty-two Chinese patients on long-term NSAID or aspirin treatment were studied for the occurrence of H. pylori infection and gastroduodenal mucosal injuries by upper endoscopy. H. pylori infection was confirmed by CLO test, histology and bacteriological cultures. Frequency and severity of symptoms of dyspepsia were also assessed. Thirty-three (40%) patients were diagnosed to have H. pylori infection and 49 (60%) patients were not infected. The two groups were comparable in age, sex, smoking and drinking habit and the use of anti-ulcer drags. Twenty-four out of 33 (72.7%) H. pylori-positive patients and 31 out of 49 (63%) of H. pylori-negative patients were found to have macroscopic lesions by endoscopy. The overall incidence of gastroduodenal lesions in the H. pylori positive patients was not significantly different from the H. pylori-negative patients (p = 0.34). However a higher incidence of duodenal ulcers in the H. pylori-infected group than the H. pylori-negative group (33% vs 6%, p = 0.0001) was found. The difference in severity and frequency of dyspeptic symptoms between the two groups did not reach statistical significance. H. pylori infected chronic NSAID users is associated with a higher rate of duodenal ulcer.
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Antiinflamatorios no Esteroideos/antagonistas & inhibidores , Infecciones por Helicobacter/complicaciones , Helicobacter pylori , Úlcera Péptica/inducido químicamente , Úlcera Péptica/etiología , Adulto , Anciano , Anciano de 80 o más Años , Endoscopía , Femenino , Humanos , Incidencia , Masculino , Persona de Mediana Edad , Úlcera Péptica/patología , Factores de Riesgo , Factores de TiempoRESUMEN
UNLABELLED: Triple therapy with bismuth, metronidazole, and tetracycline or amoxicillin is effective for the treatment of Helicobacter pylori, but side effects are common. Sucralfate inhibits H. pylori hemagglutinin, protease, and lipase and thus might affect colonization of the bacterium in the stomach. OBJECTIVE: We compared the efficacy and side effects of triple therapy with sucralfate versus triple therapy with bismuth plus omeprazole in the treatment of H. pylori-associated duodenal ulcer (DU). METHODS: One hundred and fifty DU patients were recruited in this study; 71 cases were randomized to receive bismuth 120 mg q.i.d., metronidazole 400 mg q.i.d., and tetracycline 500 mg q.i.d. (BMT) for 1 wk, and 79 cases were randomized to receive sucralfate 1 g q.i.d., metronidazole 400 mg q.i.d., and tetracycline 500 mg q.i.d. (SMT) for 1 wk. For the ulcer treatment, BMT patients were also given omeprazole 20 mg daily for 4 wk, and SMT patients received sucralfate for 4 wk from day of randomization. RESULTS: Fifty-three patients in the BMT group and 60 in the SMT group finished the treatment and follow-up at 8 wk. H. pylori was eradicated in 49 out of 53 (92%) patients in the BMT group and in 45 out of 60 (75%) patients in the SMT group (p = 0.0057). Forty-nine (92%) patients who received omeprazole and BMT and 53 (88%) patients who received SMT had healed DU at 8 wk (p = 0.34). Side effects related to medication were reported in 38 (71.7%) patients in the BMT group and in 42 (70%) patients in the SMT group. On an intention-to-treat basis, there was no difference in ulcer healing between the BMT group (93.1%) and the SMT group (89.7%). H. pylori eradication was achieved in 84.4 and 66.2% in the BMT and SMT groups, respectively (p = 0.018). CONCLUSION: Therapy of sucralfate, tetracycline, and metronidazole for 1 wk has a satisfactory but lower success rate in eradication of H. pylori when compared with the conventional triple therapy plus omeprazole. Side effects of this therapy are no fewer than the conventional triple therapy.
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Úlcera Duodenal/tratamiento farmacológico , Úlcera Duodenal/microbiología , Infecciones por Helicobacter/tratamiento farmacológico , Helicobacter pylori , Metronidazol/administración & dosificación , Sucralfato/administración & dosificación , Tetraciclina/administración & dosificación , Adulto , Bismuto/administración & dosificación , Bismuto/efectos adversos , Esquema de Medicación , Quimioterapia Combinada , Femenino , Humanos , Masculino , Metronidazol/efectos adversos , Omeprazol/administración & dosificación , Omeprazol/efectos adversos , Sucralfato/efectos adversos , Tetraciclina/efectos adversosRESUMEN
BACKGROUND: Through-the-scope balloon dilation has been used for treatment of benign pyloric stenosis; however, long-term results are lacking in the literature. METHOD: A retrospective analysis using the Kaplan-Meier method. RESULTS: Between November 1986 and December 1993, 54 patients underwent through-the-scope balloon dilations for pyloric stenosis. The mean age was 57.5 years. There were 5 (9.3%) initial treatment failures due to tight stenoses and perforations from dilation occurred in 4(7.4%) patients. Forty-five (83.3%) patients underwent successful dilation. Four patients developed rapid restenoses and were found to have malignant obstructions. Forty-one patients entered our study. Time at risk commenced on the date of initial dilation. The end point was defined at the time at which patients presented with recurrent obstruction or other ulcer complications. The median follow-up period was 39 months. The ulcer complication-free probability at 3 months, and at 1, 2, and 3 years was 79.1%, 73.4%, 69.3%, and 54.7%, respectively. In all, 21 (51.2%) patients required subsequent surgery: 18 for recurrent obstructions, 2 for interval perforations, and 1 for bleeding. CONCLUSION: While through-the-scope balloon dilation may palliate symptoms of obstruction, recurrent obstruction and other ulcer complications are common. It should be reserved only for patients at high risk for operative surgery.
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Cateterismo/métodos , Estenosis Pilórica/terapia , Adulto , Anciano , Anciano de 80 o más Años , Endoscopía del Sistema Digestivo , Femenino , Estudios de Seguimiento , Humanos , Masculino , Persona de Mediana Edad , Estudios Retrospectivos , Resultado del TratamientoRESUMEN
We compared the ulcer healing effect and eradication of H. pylori by one-week triple therapy of bismuth, metronidazole, and tetracycline with two-week dual therapy of amoxicillin and omeprazole. One hundred twelve patients with confirmed H. pylori infection and duodenal ulcers were recruited in a prospective, randomized, single-blinded trial. Ulcer healing, eradication of H. pylori in the stomach six weeks after randomization and side effect reported by patients during the therapy. Duodenal ulcers were healed in 44 of 49 (89.8%, 95% CI, 81.3-98.3 %) patients receiving triple therapy and in 44 of 53 (83.0%, 95% CI, 72.9-93.1%) patients receiving dual therapy (P=0.32). H. pylori was successfully eradicated in 41 of 49 (83.6%, 95% CI 73.4-94%) patients and in 40 of 53 (75.5%, 95% CI 63.9-87.1%) patients in the triple therapy group and the dual therapy group respectively (P=0.31). Side effects experienced by patients who received triple therapy were significantly more frequent than those who received dual therapy (P=0.0076). In conclusion, a two-week course of omeprazole and amoxicillin achieves a comparable rate of H. pylori and ulcer healing with fewer side effect.