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1.
Discov Oncol ; 14(1): 178, 2023 Sep 23.
Artículo en Inglés | MEDLINE | ID: mdl-37740836

RESUMEN

INTRODUCTION: Synergistic effects have been discussed for tyrosine kinase (TKI) and immune checkpoint inhibitors (ICI). Primary resistance to TKI might disturb subsequent ICI effectiveness. The objective was to investigate, if primary resistance to 1st line TKI monotherapy predicts response to ICI in subsequent therapy lines and impacts overall survival (OS) in advanced renal cell carcinoma (aRCC). MATERIALS AND METHODS: Retrospectively, aRCC patients which received front-line TKI from 2016 to 2019 were analyzed for the outcomes primary resistance (1LR), response to sequential ICI therapy, progression free survival (PFS) and overall survival (OS). Kaplan-Meier-estimates, Cox proportional hazards and logistic regression were used. RESULTS: Primary resistance to front-line TKI was observed in 27 (53%) of 51 patients. Groups with disease control (DC) and 1st line TKI resistance (1LR) were not different at baseline with regard to clinicopathological features. Median duration on 1st line therapy was significantly shorter in the 1LR (5.1 months) than in the DC (14.7 months) group (p = 0.01). Sequential therapy was started in 21 (75%) and 12 (52%) patients of 1LR and DC groups using nivolumab in 16 (76%) vs. 11 (92%) cases (p > 0.05). Logistic regression revealed that 1LR status, neutrophil-to-lymphocyte ratio < 3, IMDC favorable prognosis and clear cell histology had no significant impact on responsiveness to ICI in subsequent therapy lines. Cox proportional hazards demonstrated no significant association of 1LR status with PFS and OS in patients who received subsequent ICI treatment. CONCLUSION: Primary TKI resistance of aRCC was neither significantly associated with responsiveness to ICI during sequential therapy nor with PFS and OS. This adds the evidence for ICI based sequential therapy in primary TKI resistant aRCC.

2.
World Dev ; 121: 163-177, 2019 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-31481824

RESUMEN

Over the last few decades rapid advances in processes to collect, monitor, disclose, and disseminate information have contributed towards the development of entirely new modes of sustainability governance for global commodity supply chains. However, there has been very little critical appraisal of the contribution made by different transparency initiatives to sustainability and the ways in which they can (and cannot) influence new governance arrangements. Here we seek to strengthen the theoretical underpinning of research and action on supply chain transparency by addressing four questions: (1) What is meant by supply chain transparency? (2) What is the relevance of supply chain transparency to supply chain sustainability governance? (3) What is the current status of supply chain transparency, and what are the strengths and weaknesses of existing initiatives? and (4) What propositions can be advanced for how transparency can have a positive transformative effect on the governance interventions that seek to strengthen sustainability outcomes? We use examples from agricultural supply chains and the zero-deforestation agenda as a focus of our analysis but draw insights that are relevant to the transparency and sustainability of supply chains in general. We propose a typology to distinguish among types of supply chain information that are needed to support improvements in sustainability governance, and illustrate a number of major shortfalls and systematic biases in existing information systems. We also propose a set of ten propositions that, taken together, serve to expose some of the potential pitfalls and undesirable outcomes that may result from (inevitably) limited or poorly designed transparency systems, whilst offering guidance on some of the ways in which greater transparency can make a more effective, lasting and positive contribution to sustainability.

3.
Cell Tissue Res ; 325(1): 175-87, 2006 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-16525830

RESUMEN

Neuronal differentiation is characterized by stereotypical sequences of membrane channel and receptor acquisition. This is regulated by the coordinated interactions of a variety of developmental mechanisms, one of which is the control by steroid hormones. We have used the metamorphosis of the holometabolous insect, Manduca sexta, as a model to study effects of 20-hydroxyecdysone on the maturation of thoracic neuron membrane channel expression. To test for direct hormone action, neurons were dissociated into primary cell culture on the first day of pupal life. In situ hybridization demonstrated that the amount of expression of the acetylcholine receptor alpha subunit, MARA1, was not affected by 20-hydroxyecdysone. Immunocytochemistry with an antibody directed against the SP19 segment of voltage-gated sodium channels revealed no effect of 20-hydroxyecdysone treatment during the first 6 days in culture. SP19 sodium channel protein was evenly distributed along all neurites. In contrast, after 8 days in culture, 20-hydroxyecdysone increased the amount of SP19 protein expression and strongly affected its distribution in differentiating neurons. In the presence of 20-hydroxyecdysone, patches of high densities of SP19 sodium channel protein were found in growth cones close to the base of filopodia. This is a further step toward unraveling the blend of membrane proteins under the control of steroids during the development of the central nervous system of postembryonic Manduca. Our results, taken together with previous studies, indicate that 20-hydroxyecdysone does not affect the expression of potassium membrane current or of the nicotinic acetylcholine receptor but instead regulates the amplitude of the calcium membrane current and the amount and distribution of SP19 sodium channel protein.


Asunto(s)
Sistema Nervioso Central/efectos de los fármacos , Ecdisterona/farmacología , Manduca/metabolismo , Neuronas/efectos de los fármacos , Canales de Sodio/efectos de los fármacos , Animales , Células Cultivadas , Sistema Nervioso Central/citología , Sistema Nervioso Central/metabolismo , Regulación del Desarrollo de la Expresión Génica/efectos de los fármacos , Inmunohistoquímica , Hibridación in Situ , Manduca/anatomía & histología , Manduca/crecimiento & desarrollo , Microscopía Confocal , Neuronas/citología , Neuronas/metabolismo , Receptores Nicotínicos/genética , Receptores Nicotínicos/metabolismo , Canales de Sodio/metabolismo , Tórax/citología
4.
Cell Mol Biol (Noisy-le-grand) ; 49(5): 851-71, 2003 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-14528921

RESUMEN

In order to identify new orcokinin and orcomyotropin-related peptides in crustaceans, molecular and immunocytochemical data were combined with matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). In the crayfish Procambarus clarkii, four orcokinins and an orcomyotropin-related peptide are present on the precursor. Because these peptides are highly conserved, we assumed that other species have an identical number of peptides. To identify the peptides, immunocytochemistry was used to localize the regions of the stomatogastric nervous system in which orcokinins are predominantly present. One of the regions predominantly containing orcokinins was a previously undescribed olive-shaped neuropil region within the commissural ganglia of the lobsters Homarus americanus and Homarus gammarus. MALDI-TOF MS on these regions identified peptide masses that always occur together with the known orcokinins. Seven peptide ions occurred together in the peptide massspectra of the lobsters. Mass spectrometric fragmentation by MALDI-MS post-source decay (PSD) and electrospray ionization quadrupole time-of-flight mass spectrometry (ESI Q-TOF MS) collision-induced dissociation (CID) were used in the identification of six of these masses, either as orcokinins or as orcomyotropin-related peptides and revealed three hitherto unknown peptide variants, two of which are [His13]-orcokinin ([M+H]+ = 1540.8 Da) and an orcomyotropin-related peptide FDAFTTGFGHN ([M+H]+ = 1213.5 Da). The mass of the third previously unknown orcokinin variant corresponded to that of an identified orcokinin, but PSD fragmentation did not support the suggested amino acid sequence. CID analysis allowed partial de novo sequencing of this peptide. In the crab Cancer pagurus, five orcokinins and an orcomyotropin-related peptide were unambigously identified, including the previously unknown peptide variant [Ser9-Val13]-orcokinin ([M+H]+ = 1532.8 Da).


Asunto(s)
Anomuros/química , Nephropidae/química , Neuropéptidos/análisis , Sistema Nervioso Periférico/química , Secuencia de Aminoácidos , Animales , Anomuros/anatomía & histología , Decápodos/anatomía & histología , Decápodos/química , Ganglión/química , Inmunohistoquímica , Nervio Mandibular/química , Microscopía Confocal , Peso Molecular , Nephropidae/anatomía & histología , Neurópilo/química , Sistema Nervioso Periférico/anatomía & histología , Isoformas de Proteínas/análisis , Isoformas de Proteínas/fisiología , Espectrometría de Masa por Ionización de Electrospray , Espectrometría de Masa por Láser de Matriz Asistida de Ionización Desorción , Estómago/inervación
5.
Med Klin (Munich) ; 94 Suppl 3: 93-6, 1999 Oct 15.
Artículo en Alemán | MEDLINE | ID: mdl-10554541

RESUMEN

PATIENTS AND METHOD: At the Clinic for Paediatric Surgery of the University of Dresden, in a time period ranging from 5/1994 to 12/1996, all patients aged between 1 and 16 years with severe inflammatory surgical diseases or extended scalded skin, were given an adjuvant selenium substitution. As control group, all patients with the same diagnosis and age treated during the months 1/1997 to 12/1998, did not receive this adjuvant selenium substitution. All these patients fulfilled the criteria of "Systemic Inflammatory Response Syndrome" (SIRS). The selenium-therapy group consisted of 34 patients and the control group without substitution consisted of 31 patients. The following laboratory parameters were measured on the 1st, 2nd, 3rd, 6th and last treatment day: white blood cell count, interleukin 6, C-reactive protein, fibrinogen, malondialdehyde, activity of glutathione peroxidase in plasma and level of selenium in plasma and whole blood. RESULTS: The initially high interleukin 6 rates declined significantly in both groups from the 2nd day on. The acute phase proteins, i.e. the C-reactive protein and fibrinogen, normalized in both groups after the 3rd day of treatment. The initial low rates of selenium in plasma and blood gained more rapidly a normal level in the therapy group than in the control group. On the 1st day of therapy the glutathione peroxidase activity in plasma was in both groups at the inferior limit of norm range and remained at this level in the control group for the whole observation period. In the selenium-substitution group on the contrary, these initial low values raised to the double as an expression of an elevated cell membrane protection. The initial significant elevated malondialdehyde rates in both groups, expressing a raised lipidperoxidation, fell down to a normal level in the selenium-substitution group, whereas they remained at their initial high level in the control group during the whole observation period. CONCLUSION: The substitution of selenium in children with SIRS is a supportive therapy.


Asunto(s)
Selenio/administración & dosificación , Síndrome de Respuesta Inflamatoria Sistémica/tratamiento farmacológico , Adolescente , Niño , Preescolar , Femenino , Humanos , Lactante , Masculino , Estrés Oxidativo/efectos de los fármacos , Síndrome de Respuesta Inflamatoria Sistémica/etiología , Resultado del Tratamiento
6.
Med Klin (Munich) ; 92 Suppl 3: 17-9, 1997 Sep 15.
Artículo en Alemán | MEDLINE | ID: mdl-9417488

RESUMEN

PATIENTS AND METHOD: Substitution of selenium was performed in the University Clinic of Paediatric Surgery in Dresden in the time from 1994 to 1996 in 34 children aged 1 to 16 years with severe inflammatory surgical diseases as well a s widespread burns. Seven further patients have been examined within this time who have not received substitution of selenium as preliminary comparison group. All these patients fulfilled the criteria of "Systemic Inflammatory Response Syndrome" (SIRS). The following paraclinical parameters were examined: white cell count, interleukin 6, C-reactive protein, fibrinogen, malondialdehyde, activity of glutathione peroxidase in plasma and level of selenium in plasma and whole blood. RESULTS: Patients with initially low level of selenium who received substitution of selenium reached normal ranges more quickly than patients without substitution. Originally partly elevated values of malondialdehyde as sign of increased peroxidation of lipids were normalized under substitution of selenium. Initially low activity of selenium level in plasma showed a clear increase under substitution of selenium as sign of increased protection of the cell membrane. CONCLUSION: The substitution of selenium in children with SIRS is a supportive therapy.


Asunto(s)
Antioxidantes/administración & dosificación , Quemaduras/cirugía , Selenito de Sodio/administración & dosificación , Síndrome de Respuesta Inflamatoria Sistémica/cirugía , Adolescente , Quemaduras/enzimología , Niño , Preescolar , Femenino , Glutatión Peroxidasa/sangre , Humanos , Lactante , Peroxidación de Lípido/efectos de los fármacos , Masculino , Malondialdehído/sangre , Especies Reactivas de Oxígeno/metabolismo , Síndrome de Respuesta Inflamatoria Sistémica/enzimología
7.
Gynecol Oncol ; 55(1): 25-8, 1994 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-7959261

RESUMEN

Compared to extraperitoneal laparotomy, the transperitoneal approach is associated with increased enteric morbidity. Recently, transperitoneal laparoscopy has been employed as a method to surgically stage patients with gynecologic malignancies. The objective of this study was to investigate pelvic adhesion formation in a porcine model after pelvic lymphadenectomy performed via transperitoneal laparoscopy (LS) compared to extraperitoneal laparotomy (EP). Ten adult, female hogs underwent LS and 10 underwent EP. A complete pelvic lymphadenectomy was performed in each animal. Three weeks after the lymphadenectomy, the animals underwent exploratory laparotomy, and the adhesions were quantified. Nineteen animals were evaluable. The adhesion scores for the laparoscopy group (N = 10, mean = 0.075 +/- 0.17) were not statistically different from those of the laparotomy group (N = 9, mean = 0.28 +/- 0.52, P > 0.5). Eight of 10 (80%) and 5 of 9 (56%) animals in the LS and EP groups, respectively, had no adhesions after pelvic lymphadenectomy. Adhesion formation is one of many critical issues concerning the utility of pretreatment surgical staging, especially for cancer of the cervix. It is remarkable that only 20% of the animals undergoing laparoscopy in this study had de novo adhesions after pelvic lymph node dissection and that the mean total adhesion score was not statistically different from the extraperitoneal laparotomy. Therefore, transperitoneal laparoscopic pelvic lymphadenectomy may not induce the degree of adhesion formation associated with the transperitoneal laparotomy technique.


Asunto(s)
Escisión del Ganglio Linfático , Pelvis/cirugía , Complicaciones Posoperatorias , Animales , Femenino , Laparoscopía , Laparotomía , Peritoneo , Infección de la Herida Quirúrgica , Porcinos , Adherencias Tisulares/etiología
8.
Pancreas ; 8(2): 171-5, 1993 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-8460092

RESUMEN

Viable pancreas fragments from five human donors were incubated in oxygenated buffered Eagle Medium. The preparation and incubation conditions were based on the method of Scheele and Palade. In Group 1 there was 1-h preincubation with echothiophate (10(-4) M); then, acetylcholine (10(-5) M) was added. After 2 h tissues were prepared for electron microscopy. Acinar injury with vacuole formation was apparent. Many of these changes were observed in fragments incubated only with acetylcholine (10(-5) M) (Group 2) and in incubates with echothiophate only (10(-4) M) (Group 3); only minor changes were seen in controls with Eagle's Medium (Group 4). Large vacuoles were significantly more numerous in Group 1 than in Control Group 4 (p < 0.05). Zymogen granules were depleted in Groups 1, 2, and 3. This depletion was significant in Group 1 when compared with Group 4 (p < 0.02). These results extend previous in vitro results that showed increased amylase release after echothiophate treatment in human pancreas and a left shift in response to acetylcholine.


Asunto(s)
Yoduro de Ecotiofato/toxicidad , Pancreatitis/inducido químicamente , Acetilcolina/toxicidad , Enfermedad Aguda , Humanos , Técnicas In Vitro , Microscopía Electrónica , Páncreas/ultraestructura , Pancreatitis/patología
9.
Pancreas ; 6(4): 398-403, 1991 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-1715083

RESUMEN

Human pancreas contains two cholinesterase isoenzymes: acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE). In the present study, binding potency of two organophosphates for human cholinesterases were compared by the Ellman method. Echothiophate was found to have much greater potency than iso-OMPA for both cholinesterases. Using Karnovsky histochemical stains on human pancreatic tissue, the same results were confirmed. Dose-response studies with acetylcholine were done on viable pancreas fragments from nine human donors, without pancreatic disease (group I). Cold-preservation time was less than 30 h. Pancreas was minced into fragments, after the technique of Scheele and Palade, placed in Eagle's medium, and gassed with O2. Amylase release was measured by the Phadebas Method and corrected for basal release. There was a dose-dependent response to acetylcholine at 1 and 2 h, with a shift in peak amylase release to the left, when fragments were preincubated in 10(-4) M echothiophate. This indicated a 100-fold increase in sensitivity to acetylcholine. In three patients with chronic pancreatitis (Group II), there were variable patterns of response of amylase release to acetylcholine, and higher basal outputs. In Group III, prolonged storage conditions of over 40 h were tested for 4 pancreas donor tissues. There was no response to acetylcholine. These studies show that for up to 30 h cold storage, fragments of pancreas from human organ donors respond to acetylcholine in dose-dependent manner. An organophosphate, echothiophate (10(-4) M) which inhibits both cholinesterases, increases pancreatic sensitivity to acetylcholine, and these results are similar to findings from canine pancreas fragments, which also showed increased sensitivity.


Asunto(s)
Acetilcolina/farmacología , Compuestos Organofosforados/farmacología , Páncreas/efectos de los fármacos , Amilasas/metabolismo , Colinesterasas/metabolismo , Relación Dosis-Respuesta a Droga , Yoduro de Ecotiofato/metabolismo , Yoduro de Ecotiofato/farmacología , Humanos , Compuestos Organofosforados/metabolismo , Páncreas/enzimología , Páncreas/metabolismo , Pancreatitis/inducido químicamente , Tetraisopropilpirofosfamida/metabolismo , Tetraisopropilpirofosfamida/farmacología
10.
Z Gesamte Hyg ; 36(6): 337-9, 1990 Jun.
Artículo en Alemán | MEDLINE | ID: mdl-2392855

RESUMEN

Electrodic systems, consist of gold or silver and metals of the IV, or V, subsidiary groups of the periodic system of elements are qualified for that, because they based strength of their electrodic steepness, selectivity, potentionel stability and sensibility by destination of cyanid ions in waste-water. We are going to introduce a fast-analysis-method for cyanid ions in waste-water of technical processes, which had been tested practically by the continuous control of limits, demanded by the legislator.


Asunto(s)
Cianuros/análisis , Potenciometría/instrumentación , Contaminantes Químicos del Agua/análisis , Contaminantes del Agua/análisis , Calibración , Humanos
11.
Pancreas ; 5(2): 177-82, 1990 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-2315293

RESUMEN

Sublethal doses of organophosphate anticholinesterases cause acute pancreatitis in dogs within 2 h. In vitro studies using canine pancreatic fragments have also demonstrated that the peak of amylase release in response to acetylcholine is shifted far to the left after incubation with the organophosphates echothiophate (10(-4) M) or tetraisopropyl pyrophosphoramide (iso-OMPA) (10(-3) M), indicating an increased sensitivity of response. The present in vitro study examined whether there was also an increased susceptibility to acinar cell damage at the electron microscopic level after acetylcholine or cholecystokinin. Minced pieces of whole fresh canine pancreas 2-3 mm in size were placed in buffered Eagle's solution and gassed with 100% O2. After pretreatment 1 h with echothiophate or iso-OMPA, they were then incubated with acetylcholine (10(-5) M). Other tissues preincubated with echothiophate were stimulated with cholecystokinin (10(-9) M). These are submaximal doses for untreated canine pancreatic fragments. After acetylcholine and echothiophate or acetylcholine and iso-OMPA, there was extensive acinar damage with the appearance of large vacuoles and lakes, and interstitial edema. There was evidence of intense supramaximal stimulation and lateral exocytosis. Similar destructive changes were seen after echothiophate and cholecystokinin. In control sections from tissues stimulated with acetylcholine (10(-5) M) or cholecystokinin (10(-9) M, there were lumenal exocytotic patterns typical of submaximal stimulation. Other controls, organophosphate alone and unstimulated basal conditions, showed only minor changes. It is concluded that the increased sensitivity to acetylcholine after organophosphate incubation correlates with an increased susceptibility to acinar ultrastructural damage from acetylcholine and cholecystokinin.


Asunto(s)
Acetilcolina/toxicidad , Colecistoquinina/toxicidad , Yoduro de Ecotiofato/toxicidad , Compuestos Organofosforados/toxicidad , Pancreatitis/inducido químicamente , Tetraisopropilpirofosfamida/toxicidad , Acetilcolina/administración & dosificación , Enfermedad Aguda , Animales , Colecistoquinina/administración & dosificación , Perros , Sinergismo Farmacológico , Yoduro de Ecotiofato/administración & dosificación , Microscopía Electrónica , Pancreatitis/patología , Tetraisopropilpirofosfamida/administración & dosificación
12.
Pancreas ; 4(4): 423-8, 1989.
Artículo en Inglés | MEDLINE | ID: mdl-2474812

RESUMEN

There are two tissue-fixed cholinesterases in dog pancreas: acetylcholinesterase and butyrylcholinesterase. In the present experiments, an organophosphate that only inhibits butyrylcholinesterase (isopropylpyrophosphoramide, or iso-OMPA) was compared with echothiophate and a nonorganophosphate compound, physostigmine. The latter two agents inhibit both cholinesterases. Fresh canine pancreas from anesthetized dogs was minced into fragments and suspended in Eagle's solution gassed with 100% O2. Amylase release was measured by the Phadebas method. In 2-h dose-response studies, there was a fivefold increase in sensitivity to acetylcholine when fragments were preincubated 1 h with iso-OMPA. There was a 1,000-fold increase in sensitivity when fragments were preincubated for 1 h in echothiophate. Basal amylase release in incubates with echothiophate were also increased. In dose-response studies with CCK-8, iso-OMPA was without effect, but echothiophate treatment resulted in a greater total response to CCK-8. There was a corresponding increase in basal output with echothiophate alone. Physostigmine also potentiates the response to CCK-8. Cumulative responses up to 3 h with half-maximal acetylcholine or half-maximal CCK-8 doses showed enhanced total output in fragments preincubated with echothiophate (p less than 0.05). The enhancement effect was atropine-sensitive to hexamethonium ganglionic blockade. In calcium-free medium, the enhancement with echothiophate was greatly reduced but still present. Inhibitors of both cholinesterases in the pancreas cause a greater total amylase release to sub-maximal doses of acetylcholine and CCK-8 than agents that only inhibit butyrylcholinesterase. Though our data do not provide direct proof, the results could be explained by a greater accumulation of endogenous acetylcholine when both cholinesterases are inhibited.


Asunto(s)
Acetilcolinesterasa/metabolismo , Amilasas/metabolismo , Butirilcolinesterasa/metabolismo , Inhibidores de la Colinesterasa/farmacología , Colinesterasas/metabolismo , Yoduro de Ecotiofato/farmacología , Compuestos Organofosforados/farmacología , Páncreas/enzimología , Fisostigmina/farmacología , Tetraisopropilpirofosfamida/farmacología , Amilasas/antagonistas & inhibidores , Animales , Colecistoquinina/farmacología , Perros , Técnicas In Vitro , Páncreas/efectos de los fármacos
13.
Gastroenterology ; 94(2): 419-27, 1988 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-2446949

RESUMEN

This study was undertaken to clarify the issue of whether feedback regulation of pancreatic enzyme secretion occurs in humans. A naturally occurring inhibitor of trypsin and chymotrypsin, the Bowman-Birk inhibitor of soybeans, was used to reduce the activities of these enzymes normally secreted by the pancreas into the duodenum. Pure pancreatic juice was collected by endoscopic retrograde cannulation of the pancreatic duct in a protocol consisting of three periods: period 1 (15 min), collections of juice without return to the duodenum ("washout phase"); period 2 (35 min), intraduodenal infusion of juice to which buffered saline or heat-inactivated Bowman-Birk inhibitor had been added; and period 3 (55 min), intraduodenal infusion of juice in which greater than 90% of the trypsin and chymotrypsin activities had been abolished by treatment with the active inhibitor. Control experiments were included in which untreated juice was infused in period 3 as well as period 2. Enzyme analyses (trypsin, chymotrypsin, elastase, and amylase) of samples of juice collected at 5-min intervals revealed a twofold to threefold increase in the output and concentration of all four enzymes in period 3 compared with period 2. These results thus confirm the existence of feedback control in humans.


Asunto(s)
Jugo Pancreático/metabolismo , Inhibidor de la Tripsina de Soja de Bowman-Birk/farmacología , Inhibidores de Tripsina/farmacología , Adulto , Amilasas/metabolismo , Quimotripsina/metabolismo , Femenino , Humanos , Técnicas In Vitro , Masculino , Elastasa Pancreática/metabolismo , Jugo Pancreático/enzimología , Proteínas/metabolismo , Tripsina/metabolismo
14.
Artículo en Inglés | MEDLINE | ID: mdl-3598877

RESUMEN

The organophosphate insecticide Diazinon has been reported to cause acute pancreatitis in dogs. Based on histochemical examination of the acinar tissue, it was suggested that pancreatic tissue-fixed butyrylcholinesterase (BuChE) is the target enzyme of organophosphate toxicity. To further evaluate this theory, we exposed dogs, cats, and guinea pigs to a single sublethal dose of the organophosphate insecticide Diazinon (75 mg/kg). In cats, which lack pancreatic BuChE, no pathological changes occurred after two, three, and six hours, whereas in the guinea pigs as in dogs, both having abundant pancreatic BuChE, vacuolization of the acinar cells, interstitial edema and vasculitis indicate acute edematous pancreatitis as early as two hours. Atropine pretreatment (0.2 mg/kg) gave complete protection against pancreatitis. It was concluded that inhibition of pancreatic BuChe leads to cholinergic hyperstimulation of the acinar cell, which results in acute pancreatitis, and that pancreatic BuChE is essential for dogs and guinea pigs to downregulate cholinergic excitation. The insecticide pancreatitis model is considered a simple, non-invasive, reproducible, and cheap and useful method to evaluate early changes and methods of treatment in acute pancreatitis. Pancreatitis in humans has also been reported after accidental insecticide exposure.


Asunto(s)
Diazinón/toxicidad , Insecticidas/toxicidad , Páncreas/patología , Animales , Atropina/farmacología , Gatos , Perros , Cobayas , Microscopía Electrónica , Páncreas/efectos de los fármacos , Páncreas/ultraestructura , Secretina/farmacología , Especificidad de la Especie
16.
Pancreas ; 2(6): 664-8, 1987.
Artículo en Inglés | MEDLINE | ID: mdl-2449688

RESUMEN

Organophosphates (OPs) cause irreversible inhibition of cholinesterases (ChEs) and profound cholinergic stimulation. There are major differences in the response of the dog and cat pancreas to the in vivo administration of Diazinon (O,O-diethyl O-2-isopropyl-4-methyl-6-pyrimidyl phosphothioate), a butyrylcholinesterase (BuChE) inhibitor. Acute edematous pancreatitis is found in the dog but not in the cat. The present experiments were designed to see what effect OP had in vitro on pancreatic exocrine function of dog, cat, and guinea pig, and whether the effects were consistent with an anti-ChE activity. A water-soluble OP agent, tetraisopropyl pyrophosphoramide (iso-OMPA) at 10(-3) M, which like Diazinon inhibits BuChE, was used. Minced pieces of fresh whole pancreata 3 mm in size were taken from 3 dogs, 4 guinea pigs, and 2 cats. The tissues were placed in flasks containing Eagle's solution and gassed with 100% O2. Cumulative amylase release was measured by Phadebas method up to 3 h. At half-maximal acetylcholine (ACH) concentration (10(-5) M), the canine pancreas pretreated with iso-OMPA (10(-3) M) showed a 42-87% greater release of amylase than tissues receiving ACH alone (p less than 0.001). The same potentiated response to ACH was seen in guinea pig pancreas pretreated with iso-OMPA (p less than 0.001), but iso-OMPA pretreatment did not augment the ACH response in the cat. Atropine pretreatment effectively blocked all ACH responses, and there was no effect seen with iso-OMPA alone. In the dog, iso-OMPA in combination with half-maximal carbachol (10(-6) M), or in combination with half-maximal cholecystokinin (CCK-8) stimulation (10(-9) M), provided no potentiated amylase release.(ABSTRACT TRUNCATED AT 250 WORDS)


Asunto(s)
Amilasas/metabolismo , Inhibidores de la Colinesterasa/toxicidad , Diazinón/toxicidad , Insecticidas/toxicidad , Páncreas/enzimología , Acetilcolina/farmacología , Animales , Butirilcolinesterasa , Carbacol/farmacología , Gatos , Colecistoquinina/farmacología , Perros , Relación Dosis-Respuesta a Droga , Cobayas
17.
Am J Surg ; 147(1): 72-7, 1984 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-6691555

RESUMEN

Severe epithelial hyperplasia was produced in a canine model by the perfusion of the main pancreatic duct with 15 mM of deoxycholate at rates as low as 1.5 ml/day in 6 to 14 days. At higher rates (5 ml/day) deoxycholate caused complete epithelial cell lysis in the duct closest to the tip of the cannula with hyperplastic changes downstream from this section. Perfusion with a buffer solution alone and cannulation alone produced none of these changes in similar duct segments. No hyperplasia was seen in the upstream cannula obstructed duct, even in the presence of severe atrophy. Long-term (81 days) perfusion with 3 mM of deoxycholate at 3 ml/day resulted in more severe hyperplasia that still appeared benign. When glycine-conjugated deoxycholate was perfused through the duct, hyperplasia but no cell lysis was seen. In vitro, deoxycholate caused epithelial cell lysis in pancreatic duct fragments at concentrations of 0.5 mM and above. The results of this study suggest that secondary bile salts or other similar surface-active cytotoxic agents present in the biliary tree or duodenum may play a more important role in the pathogenesis of pancreatic ductal epithelial hyperplasia associated with pancreatic cancer than ductal obstruction.


Asunto(s)
Ácido Desoxicólico/toxicidad , Conductos Pancreáticos/patología , Animales , Reflujo Biliar/complicaciones , Ácido Desoxicólico/metabolismo , Perros , Epitelio/patología , Hiperplasia , Técnicas In Vitro
18.
Surg Gynecol Obstet ; 154(5): 681-8, 1982 May.
Artículo en Inglés | MEDLINE | ID: mdl-6176035

RESUMEN

The effects of pancreatic intraductal infusions of the surface active pancreatic ductogram enhancing agent, polyoxyethylene hydrogenated castor oil, were studied in the dog. Moderately high pressure retrograde infusions of 5 per cent polyoxyethylene hydrogenated castor oil into the main pancreatic duct resulted in pancreatitis-like changes significantly greater than those seen in the saline solution control group. These changes persisted despite buffering of the agent to physiologic pH and the elimination of nonphysiologically high pressure by direct ductal perfusion. Similar inflammatory changes were associated with ductal perfusion using oleic and, to a lesser degree, ricinoleic-fatty acids at concentrations of 10(-4) molar sufficient to account for the titratable acidity of 5 per cent polyoxyethylene hydrogenated castor oil. It is postulated that residual-free fatty acids may play some role in polyoxyethylene hydrogenated castor oil related toxicity. The surface active properties of the agent may also be involved. Caution and further research are recommended prior to widespread use of the agent in endoscopic retrograde pancreatography.


Asunto(s)
Aceite de Ricino/análogos & derivados , Páncreas/efectos de los fármacos , Pancreatitis/inducido químicamente , Tensoactivos , Amilasas/sangre , Animales , Bicarbonatos/farmacología , Aceite de Ricino/farmacología , Perros , Ácidos Oléicos/farmacología , Pancreatitis/patología , Ácidos Ricinoleicos/farmacología , Bicarbonato de Sodio , Cloruro de Sodio/farmacología , Tensoactivos/farmacología
19.
Ann Surg ; 195(4): 424-34, 1982 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-6175284

RESUMEN

Three groups of eight dogs each were studied to evaluate the early evolution of the hyperamylasemia, hyperlipasemia, and acinar cell pathology at the light and electron microscopic levels during acute Diazinon-induced pancreatitis. Two more groups of five dogs each were evaluated for the effects of cholinergic receptor blockade with atropine and ductal decompression on the evolution of serum enzyme changes and acinar cell pathology. Group I dogs received a secretin infusion of 2 units/kg/hr, and a Diazinon infusion of 75 mg/kg, and demonstrated significant increases in serum amylase and lipase at one, two and three hours. Light microscopy revealed acinar cell vacuolization and progressive interstitial edema. Electron microscopy revealed the formation of large intracytoplasmic vacuoles filled with flocculent material, the fusion of these vacuoles with basolateral membrane, and the formation of interstitial edema. In both group II dogs (that received secretin alone) and Group III dogs (that received atropine, 200 micrograms/kg IV prior to secretin and Diazinon), the serum enzyme levels and histologic results were normal. In group IV dogs, pancreatic duct cannulation to prevent hypertension prevented the hyperamylasemia and hyperlipasemia, but not the acinar cell vacuolization and interstitial edema. This model for acute interstitial pancreatitis is apparently cholinergic-receptor mediated, the serum enzyme elevations are due primarily to ductal hypertension, and the acinar cell pathology is primarily due to cholinergic stimulation and occurs independent of ductal hypertension.


Asunto(s)
Atropina/farmacología , Diazinón , Insecticidas , Pancreatitis/inducido químicamente , Enfermedad Aguda , Amilasas/sangre , Animales , Colinesterasas/metabolismo , Modelos Animales de Enfermedad , Perros , Intubación , Lipasa/sangre , Microscopía Electrónica , Páncreas/patología , Conductos Pancreáticos , Pancreatitis/enzimología , Pancreatitis/patología , Secretina/farmacología
20.
Jpn J Surg ; 12(1): 35-40, 1982.
Artículo en Inglés | MEDLINE | ID: mdl-6978423

RESUMEN

In this paper the 10th case of esophageal hematoma, a rare variant of the Mallory-Weiss syndrome, is reported. The radiographic study strongly suggested an obstructing neoplasm, however, this hematoma disappeared within five days and this same rapid disappearance was noted in dogs in which esophageal hematomas were induced. Fiberoptic esophagoscopy provides a clue to the diagnosis since the mural hematoma is differentiated from carcinoma by its dark color.


Asunto(s)
Enfermedades del Esófago/diagnóstico por imagen , Neoplasias Esofágicas/diagnóstico por imagen , Hematoma/diagnóstico por imagen , Anciano , Animales , Sulfato de Bario , Diagnóstico Diferencial , Perros , Esofagoscopía , Hemorragia Gastrointestinal/diagnóstico por imagen , Humanos , Masculino , Radiografía
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