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1.
Surg Endosc ; 37(3): 1629-1648, 2023 03.
Artículo en Inglés | MEDLINE | ID: mdl-36781468

RESUMEN

BACKGROUND: In recent years, the use of Indocyanine Green (ICG) fluorescence-guided surgery during open and laparoscopic procedures has exponentially expanded across various clinical settings. The European Association of Endoscopic Surgery (EAES) initiated a consensus development conference on this topic with the aim of creating evidence-based statements and recommendations for the surgical community. METHODS: An expert panel of surgeons has been selected and invited to participate to this project. Systematic reviews of the PubMed, Embase and Cochrane libraries were performed to identify evidence on potential benefits of ICG fluorescence-guided surgery on clinical practice and patient outcomes. Statements and recommendations were prepared and unanimously agreed by the panel; they were then submitted to all EAES members through a two-rounds online survey and results presented at the EAES annual congress, Barcelona, November 2021. RESULTS: A total of 18,273 abstracts were screened with 117 articles included. 22 statements and 16 recommendations were generated and approved. In some areas, such as the use of ICG fluorescence-guided surgery during laparoscopic cholecystectomy, the perfusion assessment in colorectal surgery and the search for the sentinel lymph nodes in gynaecological malignancies, the large number of evidences in literature has allowed us to strongly recommend the use of ICG for a better anatomical definition and a reduction in post-operative complications. CONCLUSIONS: Overall, from the systematic literature review performed by the experts panel and the survey extended to all EAES members, ICG fluorescence-guided surgery could be considered a safe and effective technology. Future robust clinical research is required to specifically validate multiple organ-specific applications and the potential benefits of this technique on clinical outcomes.


Asunto(s)
Colecistectomía Laparoscópica , Laparoscopía , Humanos , Verde de Indocianina , Consenso , Fluorescencia , Laparoscopía/métodos
2.
IDCases ; 29: e01529, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35693329

RESUMEN

Background: Cardiobacterum hominis (C. hominis) is the part of the HACEK group (Haemophilus spp, Actinobacillus spp, C. hominis, Eikenella, and Kingella spp) that accounts for the majority of the Gram-negative infective endocarditis cases. Historically, the fastidious characteristics of these microorganisms proved challenging to many clinicians. Advances in microbiological identification of culture-negative endocarditis; however, may be the reason for the rising incidence of these infections. Here, we report an incidentally diagnosed C. hominis endocarditis following an aortic valve replacement. Case report: A healthy 54-year-old gentleman presented after several months of generalized weakness and exertional intolerance. He was found to have a bicuspid aortic valve with regurgitation and underwent aortic valve replacement surgery. Intraoperatively, the patient was found to have a large perforation of the fused leaflet associated with abnormal pink tissue in the aortic valve area. The aortic valve tissue was cultured. Gram-negative rods were isolated 48 h later and were ultimately identified as C. hominis. He was successfully treated with 6 weeks of intravenous ceftriaxone with sterile blood cultures throughout the hospital stay. In retrospect, the patient's valve failure was likely secondary to subacute endocarditis from C. hominis complicated by leaflet perforation. Conclusion: C. hominis is a rare cause of infective endocarditis with an excellent prognosis when timely diagnosed and managed. By reporting this case, we wish to raise awareness of potential asymptomatic infection, particularly amongst patients with underlying native valve abnormalities, new leaflet perforation, and valve insufficiency.

4.
Pacing Clin Electrophysiol ; 41(1): 81-86, 2018 01.
Artículo en Inglés | MEDLINE | ID: mdl-29205396

RESUMEN

BACKGROUND: Cardiac conduction abnormalities requiring permanent pacemaker (PPM) implantation are major complications of transcatheter aortic valve replacement (TAVR). We aimed to investigate whether the relationship between prosthetic valve size and cardiac-gated computed tomography (CT)-based aortic root complex measurements can aid in recognizing patients at risk for PPM implantation post-TAVR. METHODS: We included 83 of 114 consecutive patients who underwent TAVR with the Edwards Sapien valve (Edwards Lifesciences, Irving, CA, USA) at our institution. We excluded patients with preexisting PPM, patients who required conversion to an open surgical procedure, and patients without CT data. We assessed the significance of various potential predictors of PPM placement post-TAVR. RESULTS: Following TAVR, eight patients (9.6%) required PPM. Prosthetic valve to sinus of Valsalva (SOV) index was significantly higher in those patients requiring a PPM post-TAVR (84.1 ± 9.3 vs 76.8 ± 7.1, P  =  0.009). CONCLUSIONS: The prosthetic valve size to diameter of SOV index was identified as a novel predictor of PPM implantation after TAVR.


Asunto(s)
Insuficiencia de la Válvula Aórtica/diagnóstico por imagen , Insuficiencia de la Válvula Aórtica/cirugía , Técnicas de Imagen Sincronizada Cardíacas , Prótesis Valvulares Cardíacas , Marcapaso Artificial , Tomografía Computarizada por Rayos X , Reemplazo de la Válvula Aórtica Transcatéter , Anciano de 80 o más Años , Femenino , Humanos , Masculino , Estudios Retrospectivos , Resultado del Tratamiento
5.
mBio ; 2(3): e00094-11, 2011.
Artículo en Inglés | MEDLINE | ID: mdl-21628500

RESUMEN

UNLABELLED: Toll-like receptor 4 is thought to have a primary role in host defense against Escherichia coli bladder colonization, based on mouse models of urinary tract infection using C3H/HeJ female mice. This strain carries a point mutation in the Tlr4 gene, which renders the mice unresponsive to lipopolysaccharide (LPS) and thus limits the bladder inflammatory response and infection resolution. The importance of Tlr4 as the sole genetic determinant of resistance or susceptibility can be questioned, however, by the observation that C3H/HeOuJ female mice with a functional Tlr4 do not effectively resolve E. coli bladder infections. The present study further examined this inconsistency by investigating the association of Tlr4 Lps(d) and Lps(n) alleles with bladder infection susceptibility by using genetic crosses of C3H/HeJ mice with Tlr4 (Lps(n)/Lps(n)) or (Lps(n)/Lps(d)) mice. Heterozygous offspring of C3H/HeJ (Lps(d)/Lps(d)) × BALB/cAnN (Lps(n)/Lps(n)) mice successfully resolved bladder infections induced by a uropathogenic E. coli strain, while heterozygous mice from a C3H/HeJ (Lps(d)/Lps(d)) × C3H/HeOuJ (Lps(n)/Lps(n)) cross had severe infections. A backcross of C3H/HeJ (Lps(d)/Lps(d)) with (BALB/cAnN × C3H/HeJ)F(1) (Lps(n)/Lps(d)) produced mice that were either resistant or susceptible to E. coli bladder infections and had Lps(d)/Lps(d) or Lps(n)/Lps(d) Tlr4 genotypes. The Lps(d)/Lps(d) or Lps(n)/Lps(d) genotypes were present in individual mice with unresolved bladder infections, and the Lps(d)/Lps(d) genotype was found in infection-resistant mice. These results indicate that at least one gene other than Tlr4 strongly influences susceptibility to E. coli bladder infections in C3H/HeJ mice. IMPORTANCE: We have previously demonstrated that mouse strains with either a functional or nonfunctional Tlr4 were not able to resolve induced Escherichia coli bladder infections and that a chromosomal site distinct from Tlr4 was associated with an inability to resolve bladder infections in C3H/HeJ mice. The present study has further investigated the relevance of Tlr4 in bladder infection resolution by defining the Tlr4 alleles present in offspring of genetic crosses of C3H/HeJ mice with infection-resistant and -susceptible inbred strains. The results of these experiments showed that mice with a normal Tlr4 on different genetic backgrounds were not able to clear E. coli bladder infections and that animals with a defective Tlr4 could successfully resolve infections. These results strongly imply the presence of a gene other than in Tlr4 as an important genetic determinant of infection resistance/susceptibility in C3H/HeJ and other inbred mouse strains used in mouse models of infectious diseases.


Asunto(s)
Infecciones por Escherichia coli/genética , Predisposición Genética a la Enfermedad , Receptor Toll-Like 4/genética , Receptor Toll-Like 4/inmunología , Vejiga Urinaria/microbiología , Infecciones Urinarias/genética , Animales , Cruzamientos Genéticos , Infecciones por Escherichia coli/inmunología , Femenino , Genotipo , Ratones , Ratones Endogámicos BALB C , Ratones Endogámicos C3H , Infecciones Urinarias/inmunología , Infecciones Urinarias/microbiología
6.
Scand J Rheumatol ; 40(3): 211-6, 2011 May.
Artículo en Inglés | MEDLINE | ID: mdl-21231806

RESUMEN

OBJECTIVES: Systemic sclerosis (SSc) is characterized by progressive fibrosis of various organs, and causes hard, tethered, and inelastic skin. The modified Rodnan score is used to quantify skin involvement, but this method is subjective and user dependent. The aim of this study was to test the ability of a new skin torsion device to measure skin elasticity in patients with SSc. METHODS: The study included 16 female SSc patients and 58 healthy controls. Skin elasticity was assessed on the forearms and backs of the hands using a new hand-held device that gently rotates the skin for 15 s to a maximum of 40 deg, and measures the speed of rotation and the angle of rotation at 15 s. Total and localized modified Rodnan scores were also documented. RESULTS: Measurements produced by the skin torsion device had good intra-subject reproducibility, particularly in the control group. The SSc patients had significantly lower skin elasticity than an age-matched subgroup of control subjects, as determined by the median speed of rotation of the device in the hands (1.91 vs. 2.60 deg/s, p < 0.0001) and forearms (1.84 vs. 2.46 deg/s, p < 0.0001), and the rotation at 15 s in the hands (28.6 vs. 39.0 deg, p < 0.0001) and forearms (27.6 vs. 36.9 deg, p < 0.0001). The presence of SSc disease was the only independent predictor of skin elasticity. CONCLUSIONS: This pilot study has shown the potential value of a new skin torsion device to assess skin involvement in patients with SSc.


Asunto(s)
Elasticidad/fisiología , Esclerodermia Sistémica/fisiopatología , Piel/fisiopatología , Adulto , Anciano , Femenino , Humanos , Persona de Mediana Edad , Proyectos Piloto , Esclerodermia Sistémica/diagnóstico , Piel/patología , Torsión Mecánica , Adulto Joven
7.
J Immunol ; 171(10): 5554-61, 2003 Nov 15.
Artículo en Inglés | MEDLINE | ID: mdl-14607963

RESUMEN

The phenomenon of tolerance to noninherited maternal Ags (NIMA) is poorly understood. To analyze the NIMA effect C57BL/6 (H-2(b/b)) males were mated with B6D2F(1) (H-2(b/d)) females, whereby 50% of the offspring are H-2(b/b) mice that have been exposed to maternal H-2(d) alloantigens. Controls were H-2(b/b) offspring of C57BL/6 mothers, either inbred C57BL/6 mice or F(1) backcross mice from breedings with H-2(b/d) fathers. We found that 57% of the H-2(b/b) offspring of semiallogeneic (H-2(b/d)) mothers accepted fully allogeneic DBA/2 (H-2(d/d)) heart grafts for >180 days, while similar transplants were all rejected by day 11 in controls (p < 0.0004). Foster nursing studies showed that both oral and in utero exposure to NIMA are required for this tolerogenic effect. An effect of NIMA was also found to extend the survival of skin grafts from a semiallogeneic donor (p < 0.02). Pretransplant analysis of splenocytes showed a 40-90% reduction of IL-2-, IL-5-, and IFN-gamma-producing T cells responding to H-2(d)-expressing APC in NIMA(d)-exposed vs control mice. Injection of pregnant BALB/c-dm2 (H-2L(d)-negative) female mice i.v. with H-2L(d)(61-80) peptide profoundly suppressed the offspring's indirect pathway alloreactive CD4(+) T cell response to H-2L(d). These results suggest that the natural exposure of the fetus and newborn to maternal cells and/or soluble MHC Ags suppresses NIMA-allospecific T cells of the offspring, predisposing to organ transplant tolerance in adult mice.


Asunto(s)
Antígenos H-2/inmunología , Tolerancia Inmunológica , Intercambio Materno-Fetal/inmunología , Animales , Animales Recién Nacidos/inmunología , Vasos Coronarios/trasplante , Cruzamientos Genéticos , Femenino , Feto/inmunología , Refuerzo Inmunológico de Injertos/métodos , Supervivencia de Injerto/genética , Supervivencia de Injerto/inmunología , Antígenos H-2/administración & dosificación , Antígenos H-2/genética , Trasplante de Corazón/inmunología , Trasplante de Corazón/patología , Antígeno de Histocompatibilidad H-2D , Tolerancia Inmunológica/genética , Inmunoglobulina G/biosíntesis , Inyecciones Intravenosas , Masculino , Intercambio Materno-Fetal/genética , Ratones , Ratones Endogámicos C57BL , Ratones Endogámicos DBA , Fragmentos de Péptidos/administración & dosificación , Fragmentos de Péptidos/inmunología , Embarazo , Trasplante de Piel/inmunología , Subgrupos de Linfocitos T/inmunología
8.
Artículo en Inglés | MEDLINE | ID: mdl-12504186

RESUMEN

A sensitive bioanalytical method for the measurement of dexloxiglumide, a new selective and potent cholecystokinin type-1 (CCK(1)) receptor antagonist, in plasma, is reported. The method is based on reversed-phase liquid chromatography with ultraviolet absorption detection. Samples are extracted under acidic conditions into an organic solvent, and following evaporation, reconstitution and centrifugation stages, the supernatant is injected on to an ODS column with detection at 244 nm. The method has been validated over the concentration range 0.2-20 microgram/ml, 0.2 microgram/ml being the lower limit of quantification. The overall precision and accuracy (expressed as relative error) of the method was less than 6.1 and 2.3%, respectively. Dexloxigulmide was shown to be stable in plasma when stored at -20 degrees C for at least 200 days. The method is suitable for studying the pharmacokinetics of dexloxiglumide in man.


Asunto(s)
Ácidos Pentanoicos/sangre , Receptores de Colecistoquinina/antagonistas & inhibidores , Calibración , Humanos , Ácidos Pentanoicos/farmacocinética , Estándares de Referencia , Reproducibilidad de los Resultados , Sensibilidad y Especificidad
9.
Xenobiotica ; 32(8): 699-713, 2002 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-12296990

RESUMEN

1. Single oral doses of a solution formulation of (14)C-droloxifene citrate (141 mg) appeared to be rapidly and well absorbed in four post-menopausal female subjects. Peak plasma concentrations (C(max)) of total (14)C (1260 ng eq. ml(-1)), droloxifene (196 ng ml(-1)) and the major metabolite droloxifene glucuronide (851 ng eq. ml(-1)) occurred at 0.9-1.1 h (T(max)) and declined bi-exponentially with terminal half-lives of 45.0, 31.6 and 32.0 h respectively. The mean AUCs of droloxifene and the major metabolite were 21 and 37% respectively that of total (14)C. 2. Total (14)C was excreted slowly, mainly in the faeces. Mean totals of 6.6 and 90.3% of the dose were excreted in the urine and faeces respectively during 11 days. The data were consistent with biliary excretion and enterohepatic circulation of the major metabolite, droloxifene glucuronide. 3. GC-MS showed that the major (14)C-components in 0-24-h urine were droloxifene (mean 0.4% dose) and its glucuronide (2.3% dose), and in faeces were droloxifene (60.2% dose) and N- desmethyldroloxifene (4.2% dose). Other components in faeces corresponded chromatographically to reference standards, droloxifene N-oxide (1.9% dose), side-chain hydroxylated droloxifene (dimethylamine moiety of droloxifene side-chain replaced by hydroxyl, 1.3% dose) and droloxifene glucuronide (10.7% dose). The latter was resistant to enzymic hydrolysis by the beta-glucuronidase used. 4. Intersubject variability in the pharmacokinetics of droloxifene in this study was relatively low (CV < 20% for AUC and half-life).


Asunto(s)
Moduladores de los Receptores de Estrógeno/farmacocinética , Tamoxifeno/análogos & derivados , Tamoxifeno/farmacocinética , Área Bajo la Curva , Radioisótopos de Carbono/farmacocinética , Cromatografía , Cromatografía en Capa Delgada , Femenino , Cromatografía de Gases y Espectrometría de Masas , Glucuronidasa/metabolismo , Humanos , Hidrólisis , Espectrometría de Masas , Modelos Químicos , Posmenopausia , Factores de Tiempo
10.
Physiol Behav ; 59(2): 213-9, 1996 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-8838597

RESUMEN

Excessive dietary Fe is known to be toxic, but the extent of neurobiological involvement is not clear. In the present study male weanling rats were fed diets containing Fe at 35 (control), 350, 3500, or 20000 ppm for 12 wk. An Fe-deficient group (4 ppm) was included for comparison. Rats were tested for behavioral and body weight changes at various times after initiation of diets, and liver and brain nonheme Fe were measured at term. Excess dietary Fe, primarily at 20000 ppm, significantly decreased activity, habituation, reflex startle, and conditioned avoidance response performance, and enhanced prepulse modulation of startle. Body weights were also markedly decreased. Fe-deficient animals showed similar behavioral effects but more moderate body weight changes. Liver nonheme Fe varied directly with dietary levels. Whole-brain nonheme Fe was significantly reduced in Fe-deficient animals but increased only at the 20000-ppm level. Homeostatic mechanisms appear to regulate whole-brain Fe more effectively under conditions of dietary Fe overload than under conditions of Fe deficiency. The behavioral changes associated with dietary Fe overload may represent secondary consequences of systemic toxicity.


Asunto(s)
Conducta Animal/efectos de los fármacos , Encéfalo/efectos de los fármacos , Sobrecarga de Hierro/fisiopatología , Hierro/toxicidad , Anemia Ferropénica/patología , Anemia Ferropénica/fisiopatología , Animales , Reacción de Prevención/efectos de los fármacos , Reacción de Prevención/fisiología , Conducta Animal/fisiología , Encéfalo/patología , Condicionamiento Clásico/efectos de los fármacos , Condicionamiento Clásico/fisiología , Relación Dosis-Respuesta a Droga , Hierro/metabolismo , Sobrecarga de Hierro/patología , Masculino , Actividad Motora/efectos de los fármacos , Actividad Motora/fisiología , Ratas , Ratas Sprague-Dawley , Reflejo de Sobresalto/efectos de los fármacos , Reflejo de Sobresalto/fisiología
12.
J Am Acad Dermatol ; 28(5 Pt 2): 853-8, 1993 May.
Artículo en Inglés | MEDLINE | ID: mdl-8491880

RESUMEN

A 65-year-old woman treated with etretinate for pityriasis rubra pilaris developed chronic active hepatitis. The elevated transaminases were noted 2 months after initiation of therapy and peaked 2 months after discontinuation of etretinate. The spectrum of liver toxicity induced by etretinate is reviewed. We suggest that reported cases of retinoid-induced liver disease can be divided into four distinct categories: nonspecific reactive hepatitis, acute hepatitis, chronic active hepatitis, and severe fibrosis or cirrhosis.


Asunto(s)
Enfermedad Hepática Inducida por Sustancias y Drogas/etiología , Etretinato/efectos adversos , Anciano , Enfermedad Hepática Inducida por Sustancias y Drogas/patología , Enfermedad Hepática Crónica Inducida por Sustancias y Drogas , Femenino , Hepatitis Crónica/patología , Humanos , Hígado/patología , Pitiriasis Rubra Pilaris/tratamiento farmacológico
13.
Biopharm Drug Dispos ; 12(7): 481-92, 1991 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-1932611

RESUMEN

The pharmacokinetics of the anti-inflammatory drug benzydamine were determined after intravenous infusion of 5 mg to six healthy male subjects. Benzydamine was characterized as a drug of relatively low systemic clearance (ca. 160 ml min-1) but high volume of distribution (ca. 1101); the apparent terminal half-life in plasma was ca. 8 h. Benzydamine was well absorbed after oral administration, as indicated by a mean systemic availability of 87 per cent. However, absorption of the drug was low (less than 10 per cent of the dose) after its use by male subjects as a mouthwash, or after its application to female subjects as dermal cream and vaginal douche preparations. The data suggest that benzydamine is generally not well absorbed through the skin and non-specialized mucosae, thereby limiting unrequired systemic exposure to this drug when it is used by these routes.


Asunto(s)
Bencidamina/administración & dosificación , Administración Cutánea , Administración Intravaginal , Administración Oral , Administración Tópica , Adolescente , Adulto , Bencidamina/sangre , Bencidamina/farmacocinética , Disponibilidad Biológica , Femenino , Humanos , Infusiones Intravenosas , Masculino , Persona de Mediana Edad , Antisépticos Bucales
14.
Eur J Drug Metab Pharmacokinet ; Spec No 3: 9-14, 1991.
Artículo en Inglés | MEDLINE | ID: mdl-1820942

RESUMEN

Cefepime (BMY-28142) is a new parenteral cephalosporin antibiotic with excellent activity against a broad-spectrum of clinically important pathogens resistant to other new cephalosporins. A single bolus dose of 10, 20 or 40 mg/kg cefepime was given i.v. to male and female Sprague-Dawley rats from which blood and urine samples were collected. For statistical reasons, pharmacokinetic parameters (AUC, Kel) were derived by fitting an exponential curve to the plasma concentrations; subsequently, contrasts were made between the different doses for AUC and Kel and, in addition, plasma concentrations observed after the first sampling time (Cmax). Cmax and AUC appeared to be linearly related to the administered dose in both males and females. The dose increased in the ratio 1:2:4 and mean Cmax in male and female rats increased in the ratio 1:2.3:4.1 and 1:2.3:4.4 respectively; similarly, AUC increased in the ratio 1:2.2:4.3 and 1:2.0:4.2 respectively. Deviations from linearity and proportionality were not significant (P0.05). The systemic clearance of cefepime in rats was 2.3 ml/min. The volume of distribution was about 60 ml and cefepime appears to be selectively distributed into the extracellular water. Plasma concentrations declined monoexponentially with a mean half-life of 15-20 min which did not significantly change with increasing doses. The renal clearance of cefepime was 1.8 ml/min and approximately 80% of the dose was excreted in the urine unchanged; renal excretion of cefepime is the major route of elimination in rats. The elimination and distribution characteristics of cefepime in rats were similar to those observed in man.


Asunto(s)
Cefalosporinas/farmacocinética , Animales , Cefepima , Cefalosporinas/administración & dosificación , Cromatografía Líquida de Alta Presión , Femenino , Masculino , Ratas , Ratas Endogámicas , Análisis de Regresión , Espectrofotometría Ultravioleta
15.
J Chromatogr ; 530(2): 377-85, 1990 Sep 14.
Artículo en Inglés | MEDLINE | ID: mdl-2079512

RESUMEN

A simple, sensitive and selective method for the determination of ximoprofen and its keto and hydroxy metabolites in human urine has been developed using high-performance liquid chromatography in the reversed-phase mode. The limit of reliable determination of ximoprofen and each of its metabolites in urine is about 1 microgram/ml (4 nmol/ml). The method has been applied to urine samples obtained from human volunteers after administration of single intravenous doses of 30 mg of ximoprofen and about 70% dose was accounted for in terms of these compounds and their glucuronic acid conjugates.


Asunto(s)
Antiinflamatorios no Esteroideos/orina , Fenilpropionatos/orina , Antiinflamatorios no Esteroideos/metabolismo , Biotransformación , Cromatografía Líquida de Alta Presión , Glucuronidasa , Semivida , Humanos , Concentración de Iones de Hidrógeno , Hidrólisis , Inyecciones Intravenosas , Fenilpropionatos/metabolismo , Espectrofotometría Ultravioleta
16.
J Chromatogr ; 529(1): 113-23, 1990 Jul 13.
Artículo en Inglés | MEDLINE | ID: mdl-2211924

RESUMEN

A simple, sensitive and selective method for the determination of benzydamine in human plasma and urine, and for benzydamine N-oxide in urine, has been developed using high-performance liquid chromatography in the reversed-phase mode. The limit of reliable determination of benzydamine in plasma was 0.5 ng/ml and that in urine 1 ng/ml; the limit of reliable determination of benzydamine N-oxide in urine was 50 ng/ml. The method has been successfully applied to the analysis of these compounds in biological fluids after administration of intravenous and oral doses of benzydamine to human volunteers.


Asunto(s)
Bencidamina/análogos & derivados , Bencidamina/análisis , Bencidamina/sangre , Bencidamina/orina , Cromatografía Líquida de Alta Presión , Humanos
17.
Drug Chem Toxicol ; 12(1): 1-19, 1989 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-2496967

RESUMEN

Calimycin (A23187), a divalent cationic ionophore which increases intraneuronal concentrations of calcium, has been shown to produce neurofunctional changes associated with depression of brain excitability. The present report describes further characterization of the neurofunctional effects of acute parenteral exposure to A23187. Adult male rats were tested for the effects of A23187 on operant performance and general motor activity. In order to gain some insight into the neuronal systems which may be affected by A23187, brain levels of norepinephrine (NE), dopamine, serotonin, and their metabolites were determined. In addition, provocative pharmacologic challenges were employed to assess the interaction between A23187 and the centrally active drugs amphetamine (AMPH), scopolamine (SCOP), or chlorpromazine (CPZ). A23187 was found to effectively suppress fixed ratio-15 operant performance (p less than 0.001) at a dose of 0.5 mg/kg. This effect was temporary in nature inasmuch as performance was normalized by the day after dosing. This same dose of A23187, which produces a selective hypomotility, was found to have no apparent latent effects on the processes controlling circadian motor activity. Neurochemically, A23187 at 1 mg/kg induced a 64% increase (p less than 0.01) in the NE metabolite 3-methoxy-4-hydroxyphenylglycol, although levels of NE were unaffected. In the pharmacological challenge studies, AMPH and SCOP both attenuated and CPZ enhanced the acute hypomotility induced by 0.5 mg A23187/kg. The data show that low doses of A23187 induce a specific pattern of neurobehavioral dysfunction which may involve some interaction between the central catecholaminergic and cholinergic systems.


Asunto(s)
Calcimicina/farmacología , Neuronas/efectos de los fármacos , Animales , Peso Corporal/efectos de los fármacos , Química Encefálica/efectos de los fármacos , Catecolaminas/metabolismo , Condicionamiento Operante/efectos de los fármacos , Masculino , Actividad Motora/efectos de los fármacos , Ratas , Ratas Endogámicas , Esquema de Refuerzo
20.
Neurotoxicol Teratol ; 9(2): 99-106, 1987.
Artículo en Inglés | MEDLINE | ID: mdl-3116383

RESUMEN

The divalent cationic ionophore A23187 (calimycin) facilitates the transport of calcium ions across biological membranes, resulting in an increase of cytosolic calcium. A23187 has been used extensively in vitro to activate calcium-dependent neurocellular processes. Because of its potential usefulness as a neurotoxicological probe, our laboratory conducted a series of studies to characterize the neurofunctional consequences of A23187 in the intact organism. In addition to approximating the LD50, the effects of acute parenteral administration of A23187 on conditioned avoidance, nociceptive shock threshold, open-field activity, consummatory behavior, body temperature and neuromotor function, including general activity, coordination, balance and grip strength, were assessed in the rodent. The LD50 of A23187, administered intraperitoneally to adult male rats, was 9.2 mg/kg. The predominant overt signs of toxicity included lethargy, limb weakness and apnea. Lower doses, from 0.5 to 0.03 mg/kg, produced a variety of more subtle neurobehavioral effects, including a selective depression of motor activity, a moderate elevation of shock threshold, altered conditioned avoidance behavior and hypothermia.


Asunto(s)
Conducta Animal/efectos de los fármacos , Calcimicina/toxicidad , Sistema Nervioso/efectos de los fármacos , Animales , Reacción de Prevención/efectos de los fármacos , Temperatura Corporal/efectos de los fármacos , Conducta Exploratoria/efectos de los fármacos , Inyecciones Intraperitoneales , Dosificación Letal Mediana , Masculino , Actividad Motora/efectos de los fármacos , Nociceptores/efectos de los fármacos , Ratas , Ratas Endogámicas , Factores de Tiempo
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