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1.
Dig Liver Dis ; 2023 Aug 14.
Artículo en Inglés | MEDLINE | ID: mdl-37586908

RESUMEN

BACKGROUND: The optimal strategy for second-line (IIL) treatment in KRAS wt metastatic colorectal cancer (mCRC) is not determined yet. METHODS: A random-effect NMA of phase II/III RCTs was conducted to evaluate IIL treatment for all-RAS wt mCRC, comparing anti-EGFR or anti-VEGF, and chemotherapy (CT). RESULTS: Overall, 11 RCTs (3613 patients) were included. In KRAS wt patients, PFS was improved with anti-VEGF (HR 0.43) and anti-EGFR (HR 0.63) vs CT. However, anti-VEGF based therapy had the highest likelihood of being ranked as the best treatment in terms of PFS (SUCRA 99.3%) and OS (SUCRA 99.4%). Bevacizumab-based treatment is most likely to be the best treatment in terms of PFS (SUCRA 89.1%) and OS (SUCRA 86.7%). CONCLUSIONS: Second line treatment with anti-VEGF and anti-EGFR improved PFS in mCRC patients, however, anti-VEGF based therapy, particularly CT plus bevacizumab, is the best treatment according to SUCRA in terms of PFS and OS.

2.
Ann Oncol ; 33(6): 628-637, 2022 06.
Artículo en Inglés | MEDLINE | ID: mdl-35306156

RESUMEN

BACKGROUND: Histological characteristics at the invasive front may reflect tumor aggressiveness; specifically, tumor budding (Bd) is an emerging prognostic biomarker in colon cancer (CC). We explored further the significance of Bd for risk stratification by evaluating survival of stage III CC patients included in the IDEA-France phase III trial. PATIENTS AND METHODS: This post-hoc study was conducted on tissue slides from 1048 stage III CC patients. Bd was scored by central review by the Bd criteria of the 2016 International Tumor Budding Consensus Conference (ITBCC 2016) and classified as Bd1 (0-4 buds/0.785 mm2), Bd2 (5-9 buds), and Bd3 (≥10 buds) categories. Disease-free survival (DFS) and overall survival (OS) were analyzed by the log-rank test. Clinicopathological features and Immunoscore® were correlated with Bd. RESULTS: Overall, Bd1, Bd2, and Bd3 were observed in 39%, 28%, and 33% of CC, respectively. Bd2 and Bd3 were associated with vascular (P = 0.002) and perineural invasions (P = 0.0009). The 3-year DFS and the 5-year OS rates for Bd (1 versus 2-3) were 79.4% versus 67.2% (P = 0.001) and 89.2% versus 80.8% (P = 0.001), respectively. This was confirmed after adjustment for relevant clinicopathological features for DFS [hazard ratio (HR) 1.41, 95% confidence interval (CI) 1.12-1.77, P = 0.003] and OS (HR 1.65, 95% CI 1.22-2.22, P = 0.001). When combined with pTN stage and Immunoscore® subgroups, Bd significantly improved disease prognostication. CONCLUSIONS: Bd demonstrated its independent prognostic value for DFS and OS. Given these findings, Bd as per the ITBCC 2016 should be mandatory in every pathology report in stage III CC patients. Bd and Immunoscore® could play a complementary role in personalized health care in this setting.


Asunto(s)
Neoplasias del Colon , Neoplasias del Colon/patología , Supervivencia sin Enfermedad , Francia/epidemiología , Humanos , Estadificación de Neoplasias , Pronóstico , Modelos de Riesgos Proporcionales
3.
ESMO Open ; 6(4): 100184, 2021 08.
Artículo en Inglés | MEDLINE | ID: mdl-34237612

RESUMEN

Stage II colon cancer (CC) is probably one of the best prognosis gastrointestinal tumors seen in our consultations, but often takes a lot of time for physicians to determine appropriate treatment because of the limited benefit of adjuvant chemotherapy (CT) in these patients, together with the limited evidence in this situation. How to choose the best treatment for each individual patient is thus dependent on molecular (microsatellite instability/microsatellite stability status) and clinico-pathological features relevant enough to classify these tumors into low-, intermediate- and high-risk stage II disease and to choose an appropriate attitude for each of these subgroups. In practice, the first step in treatment decision making must be to assess the patient's status and comorbidities to see if the patient is eligible for an adjuvant treatment. Then, as fluoropyrimidines (FPs) are the corner stone of CC adjuvant treatment, screening for dihydropyrimidine dehydrogenase deficiency is mandatory in western countries. Finally, depending on the patient's characteristics and tumor risk stage, the strategy may be surveillance, adjuvant FP alone or oxaliplatin-based adjuvant CT. In the near future, new tools such as Immunoscore® (HalioDx; Luminy Biotech Enterprises, Marseille Cedex, France) and circulating tumor DNA may help to identify more precisely patients with minimal residual disease for more personalized adjuvant treatment approaches.


Asunto(s)
Neoplasias del Colon , Quimioterapia Adyuvante , Neoplasias del Colon/diagnóstico , Neoplasias del Colon/tratamiento farmacológico , Neoplasias del Colon/genética , Humanos , Inestabilidad de Microsatélites , Estadificación de Neoplasias , Pronóstico
4.
Cancer Treat Rev ; 68: 102-110, 2018 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-29940524

RESUMEN

Triple negative breast cancer (TNBC) represents the 15-20% of all breast cancers (BC) and is characterized by a very aggressive behavior. Recent data suggest that TNBC is not a single disease, but it is rather an umbrella for different ontology-profiles such as basal like 1 and 2, mesenchymal, and the luminal androgen receptor (LAR). The LAR subtype is characterized by the expression of the Androgen Receptor (AR) and its downstream effects. Notwithstanding the role of the AR in several signaling pathways, its impact on a biological and clinical standpoint is still controversial. The LAR subtype has been associated with better prognosis, less chemotherapy responsiveness and lower pathologic complete response after neoadjuvant treatment. Clinical evidence suggests a role for anti-androgen therapies such as bicalutamide, enzalutamide and abiraterone, offering an interesting chemo-free alternative for chemo-unresponsive patients, and therefore potentially shifting current treatment strategies.


Asunto(s)
Antagonistas de Andrógenos/uso terapéutico , Receptores Androgénicos/biosíntesis , Neoplasias de la Mama Triple Negativas/tratamiento farmacológico , Neoplasias de la Mama Triple Negativas/metabolismo , Animales , Femenino , Humanos
5.
Acta Physiol (Oxf) ; 222(2)2018 02.
Artículo en Inglés | MEDLINE | ID: mdl-28656611

RESUMEN

Acute kidney injury (AKI) represents a significant clinical concern that is associated with high mortality rates and also represents a significant risk factor for the development of chronic kidney disease (CKD). This article will consider alterations in renal endothelial function in the setting of AKI that may underlie impairment in renal perfusion and how inefficient vascular repair may manifest post-AKI and contribute to the potential transition to CKD. We provide updated terminology for cells previously classified as 'endothelial progenitor' that may mediate vascular repair such as pro-angiogenic cells and endothelial colony-forming cells. We consider how endothelial repair may be mediated by these different cell types following vascular injury, particularly in models of AKI. We further summarize the potential ability of these different cells to mitigate the severity of AKI, improve perfusion and maintain vascular structure in pre-clinical studies.


Asunto(s)
Lesión Renal Aguda , Células Progenitoras Endoteliales , Riñón/irrigación sanguínea , Animales , Humanos , Riñón/patología , Neovascularización Fisiológica/fisiología
6.
Tissue Cell ; 44(5): 301-7, 2012 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-22608000

RESUMEN

The aim of this study was to identify and quantify the argyrophil, argentaffin and insulin-immunoreactive cells (IIC) in the small intestine of the opossum Didelphis aurita. Seven adult male specimens of opossums were investigated. The animals were captured, and their blood insulin levels were determined. After euthanasia, fragments of the small intestine were processed for light microscopy and transmission electron microscopy, and submitted to histochemistry and immunohistochemistry for identification of argyrophil and argentaffin endocrine cells, and IIC. Argyrophil and argentaffin cells were identified in the intestinal villi and Liberkühn crypts, whereas IIC were present exclusively in the crypts. Ultrastructure of the IIC revealed cytoplasmic granules of different sizes and electron densities. The numbers of IIC per mm(2) in the duodenum and jejunum were higher than in the ileum (p<0.05). The animals had low levels of blood insulin (2.8 ± 0.78 µIU/ml). There was no correlation between insulin levels and the number of IIC in the small intestine. The IIC presented secretory granules, elongated and variable morphology. It is believed that insulin secretion by the IIC may influence the proliferation of cells in the Liberkühn crypts, and local glucose homeostasis, primarily in animals with low serum insulin levels, such as the opossum.


Asunto(s)
Didelphis/metabolismo , Células Endocrinas/metabolismo , Células Endocrinas/ultraestructura , Células Enterocromafines/metabolismo , Insulina/metabolismo , Intestino Delgado/metabolismo , Animales , Proliferación Celular , Gránulos Citoplasmáticos/ultraestructura , Didelphis/inmunología , Células Endocrinas/citología , Células Enterocromafines/citología , Células Enterocromafines/ultraestructura , Inmunohistoquímica , Insulina/inmunología , Mucosa Intestinal/citología , Mucosa Intestinal/ultraestructura , Intestino Delgado/ultraestructura , Masculino , Microscopía Electrónica de Transmisión , Zarigüeyas/metabolismo
7.
Neurotoxicology ; 32(1): 140-9, 2011 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-20932997

RESUMEN

Peripheral neuropathy is a major side effect following treatment with the cancer chemotherapeutic drug paclitaxel. Whether paclitaxel-induced peripheral neuropathy is secondary to altered function of small diameter sensory neurons remains controversial. To ascertain whether the function of the small diameter sensory neurons was altered following systemic administration of paclitaxel, we injected male Sprague Dawley rats with 1mg/kg paclitaxel every other day for a total of four doses and examined vasodilatation in the hindpaw at day 14 as an indirect measure of calcitonin gene related peptide (CGRP) release. In paclitaxel-treated rats, the vasodilatation induced by either intradermal injection of capsaicin into the hindpaw or electrical stimulation of the sciatic nerve was significantly attenuated in comparison to vehicle-injected animals. Paclitaxel treatment, however, did not affect direct vasodilatation induced by intradermal injection of methacholine or CGRP, demonstrating that the blood vessels' ability to dilate was intact. Paclitaxel treatment did not alter the compound action potentials or conduction velocity of C-fibers. The stimulated release of CGRP from the central terminals in the spinal cord was not altered in paclitaxel-injected animals. These results suggest that paclitaxel affects the peripheral endings of sensory neurons to alter transmitter release, and this may contribute to the symptoms seen in neuropathy.


Asunto(s)
Miembro Posterior/irrigación sanguínea , Miembro Posterior/efectos de los fármacos , Paclitaxel/toxicidad , Células Receptoras Sensoriales/efectos de los fármacos , Vasodilatación/efectos de los fármacos , Animales , Péptido Relacionado con Gen de Calcitonina/metabolismo , Miembro Posterior/fisiología , Masculino , Ratas , Ratas Sprague-Dawley , Células Receptoras Sensoriales/fisiología , Vasodilatación/fisiología
8.
Minerva Pediatr ; 62(5): 425-30, 2010 Oct.
Artículo en Italiano | MEDLINE | ID: mdl-20940677

RESUMEN

The authors have studied the influence of family history of type 2 diabetes on the physical phenotype of 47 health adolescents. In both sexes groups with positive family history (FH+) had the highest values of stature and body weight (P<0.05 for males, not significant for females), waist circumference (P<0.05 for males, not significant for females), and wrist circumference (P=0.05 for males, not significant for females). Considering athletic performance, FH+ males showed a significant higher performance in power exercises than FH- males; no significant differences were found between FH+ and FH- female groups. The study confirms that family history of type 2 diabetes can induce in both sexes precocious phenotype and athletic performances linked-related variations; larger studies are necessary to confirm these data and to verify preventive interventions promoting significant life-style changes.


Asunto(s)
Diabetes Mellitus Tipo 2/genética , Deportes/fisiología , Adolescente , Femenino , Humanos , Masculino , Fenotipo , Proyectos Piloto
9.
Minerva Cardioangiol ; 58(4): 425-31, 2010 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-20938409

RESUMEN

AIM: Cryptogenic stroke remains the final diagnosis in 40% of ischemic acute cerebrovascular events. Until now there are no clinical evidences that the percutaneous closure of PFO is able to prevent the recurrence of stroke or transient ischemic attack (TIA). The aim of this study was to evaluate the incidence of recurrence in patients successfully treated by percutaneous closure of PFO with different occluder devices by using TCD, TTE and clinical evaluation. METHODS: From February 2004 to November 2009, 72 pts, (40 females and 32 males; average age 46 yrs, range 14-66), admitted with diagnosis of recurrent ischemic neurologic events (58 stroke and 14 TIA) underwent percutaneous closure of PFO. Thirty-one (43%) of the 72 patients had a concomitant history of migraine, 16 (52%) of whom with aura. Five different occluder devices were used, with a total amount of 74 implants. All pts were studied during the follow-up by clinical evaluation (Rankin modified scale), TCD and TTE. RESULTS: Successful device deployment is achieved in 100% of pts without any periprocedural major complication. Only in two pts atrial arrhythmia have occurred. All pts was discharged within 3 days in good overall conditions. In all pts a double antiplatelet regimen was adopted. The follow-up was complete in 100% of the cases (median 30, range 3-58 months ). At five years, there was no recurrent stroke or TIA, and no new cerebral lesions developed by MRI in those patients with residual shunt. Moreover, in 65 (90%) of them the Rankin scale significantly (P<0.0001) reduced to 0 whereas only in 2 pts score 1 was reached. In 19 (61%) of the 31pts with concomitant migraine, the intensity and the frequency of the attacks significantly (P<0.0001) decreased over time. At the TCD, 5 pts (7%) resulted positive for microembolic signals but, only 1 of them, was successfully treated for an associate defect. The TTE evaluation showed however an optimal sealing of all the devices without signs of erosion, incomplete closure and thrombus formation around the device. CONCLUSION: Our experience suggests that percutaneous treatment of PFO is safe and beneficial at the medium term follow-up for secondary prevention since able to prevent the clinical recurrence of acute cerebrovascular events irrespective of the device used.


Asunto(s)
Foramen Oval Permeable/cirugía , Ataque Isquémico Transitorio/etiología , Dispositivo Oclusor Septal , Accidente Cerebrovascular/etiología , Adolescente , Adulto , Anciano , Ecocardiografía Transesofágica , Femenino , Estudios de Seguimiento , Humanos , Ataque Isquémico Transitorio/prevención & control , Masculino , Persona de Mediana Edad , Trastornos Migrañosos/complicaciones , Prevención Secundaria , Accidente Cerebrovascular/prevención & control , Resultado del Tratamiento , Ultrasonografía Doppler Transcraneal , Adulto Joven
11.
J Neurosurg Sci ; 53(2): 55-7, 2009 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-19546844

RESUMEN

Chronic subdural hematoma (CSDH) is a common pathology in the elderly but very rare in young adults. When CSDH occurs in this age group, severe head injury or some promotive factors are usually present. This article reports the case of a 29-year-old female presented at our Emergency Department with a few days' history of progressive frontal headache. Computed tomography scan of the head showed a right frontal CSDH. Only a decreased level of consciousness without focal deficits was present at clinical examination and her medical history was negative for trauma or promotive factors. Blood count showed a mild sideropenic anemia while coagulation tests were normal. No vascular malformations were shown at digital subtraction angiography. The patient underwent craniotomic evacuation. After surgery, the patient showed a full neurological recovery. Spontaneous CSDH in young adults is very rare. In the worldwide literature, many cases of non-traumatic CSDH are reported, but a promotive factor is generally present. We described a case of spontaneous CSDH, whose etiology remains unknown.


Asunto(s)
Craneotomía , Hematoma Subdural Crónico , Tomografía Computarizada por Rayos X , Adulto , Femenino , Hematoma Subdural Crónico/diagnóstico por imagen , Hematoma Subdural Crónico/etiología , Hematoma Subdural Crónico/cirugía , Humanos , Recuperación de la Función
12.
Kidney Int ; 72(2): 151-6, 2007 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-17495858

RESUMEN

Recent evidence suggests that injury to the renal vasculature may play an important role in the pathogenesis of both early and chronic ischemic acute kidney injury (AKI). Established and new data support the suggestion that vascular injury, in particular, endothelial cell injury, participates in the extent and maintenance of AKI by pathways that are related to vascular tone. Early alterations in peritubular capillary blood flow during reperfusion has been documented and associated with loss of normal endothelial cell function, which can be replaced pharmacologically or with cell replacement interventions. Distorted peritubular capillary morphology is associated with loss of barrier function that may contribute to early alterations in vascular stasis. In addition, ischemia induces alterations in endothelial cells that may promote inflammation and procoagulant activity, thus contributing to vascular congestion. Reductions in microvasculature density may play a critical part in the progression of chronic kidney disease following initial recovery from ischemia/reperfusion-induced AKI. The exact nature of how capillary loss alters renal function and predisposes renal disease is thought to be due at least in part to hypoxia. Finally, the loss of endothelial cell function may represent an important therapeutic target in which nitric oxide, vascular trophic support, and/or endothelial progenitor cells may show potential importance in ameliorating the acute and/or chronic effects of ischemic AKI.


Asunto(s)
Lesión Renal Aguda/patología , Endotelio Vascular/patología , Isquemia/patología , Células Endoteliales/patología , Humanos , Riñón/irrigación sanguínea , Riñón/patología , Microcirculación/patología
13.
Am J Physiol Renal Physiol ; 281(5): F887-99, 2001 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-11592947

RESUMEN

Acute episodes of severe renal ischemia result in acute renal failure (ARF). These episodes are followed by a characteristic recovery and repair response, whereby tubular morphology and renal function appear completely restored within approximately 1 mo. However, the chronic effects of such an injury have not been well studied. Male rats were subjected to 60-min bilateral ischemia followed by reperfusion, yielding a characteristic injury. Postischemic animals manifested severe diuresis, peaking at 1 wk postinjury (volume: >45 ml/day, ARF vs. 18 ml/day, sham; P < 0.05). Urine flow subsequently declined but remained significantly elevated vs. sham animals for a 40-wk period. The prolonged alteration in urinary concentrating ability was attributable, in part, to a diminished capacity to generate a hypertonic medullary interstitium. By week 16, proteinuria developed in the post-ARF group and progressed for the duration of the study. Histological examination revealed essentially normal tubular morphology at 4 and 8 wk postinjury but the development of tubulointerstitial fibrosis at 40 wk. Transforming growth factor (TGF)-beta1 expression was elevated at 40 wk, but not at 4 and 8 wk postinjury. Microfil analysis revealed an approximately 30-50% reduction in peritubular capillary density in the inner stripe of the outer medulla at 4, 8, and 40 wk in post-ARF groups vs. sham animals. In addition, post-ARF rats manifested a significant pressor response to a low dose of ANG II (15 ng x kg(-1) x min(-1)). We hypothesize that severe ischemic injury results in a permanent alteration of renal capillary density, contributing to a urinary concentrating defect and the predisposition toward the development of renal fibrosis.


Asunto(s)
Capilares/fisiopatología , Isquemia/fisiopatología , Riñón/irrigación sanguínea , Daño por Reperfusión/fisiopatología , Lesión Renal Aguda/etiología , Animales , Presión Sanguínea , Deshidratación , Diuresis , Fibrosis , Riñón/patología , Capacidad de Concentración Renal , Túbulos Renales/irrigación sanguínea , Masculino , Natriuresis , Concentración Osmolar , Proteinuria , ARN Mensajero/análisis , Ratas , Ratas Sprague-Dawley , Factor de Crecimiento Transformador beta/genética , Factor de Crecimiento Transformador beta1 , Orina
15.
J Surg Res ; 98(2): 123-8, 2001 Jun 15.
Artículo en Inglés | MEDLINE | ID: mdl-11397128

RESUMEN

BACKGROUND: Iron deficiency results in altered gallbladder and sphincter of Oddi (SO) motility and cholesterol crystal formation. In addition, gallbladder neuronal nitric oxide synthase (nNOS) has been shown to be markedly reduced after 8 weeks on an iron-deficient diet. However, the effects of prolonged iron deficiency on gallbladder and SO nNOS as well as crystal formation have not been determined. Therefore, we tested the hypothesis that iron deficiency would downregulate both gallbladder and SO nNOS expression and that nNOS downregulation and cholesterol crystal formation would progress over time. MATERIALS AND METHODS: Thirty-eight adult female prairie dogs were fed either an ironsupplemented (Fe+) (200 ppm) or an iron-deficient (Fe-) (8 ppm) diet for 8 weeks (Fe+ n = 9, Fe- n = 10) or 16 weeks (Fe+ n = 9, Fe- n = 10). Blood hemoglobin (HbG) was measured; gallbladder cholesterol crystals were counted; and cholesterol saturation indices (CSI) were calculated. Gallbladder and SO nNOS levels were measured by Western blot. RESULTS: The Fe+ prairie dogs had significantly higher HbG than the Fe- animals (16.9 +/- 0.6 g/dl vs 15.2 +/- 0.5 g/dl, respectively, P < 0.05) after 8 weeks. This difference was even greater after 16 weeks (16.1 +/- 0.4 g/dl vs 14.0 +/- 0.5 g/dl, P < 0.01). At 8 weeks, more cholesterol crystals per 10 HPF were observed in the Fe- animals (0.4 +/- 0.3 vs 1.6 +/- 0.4 per 10 HPF, P < 0.05). This difference was even greater after 16 weeks (0.0 +/- 0.0 vs 52.6 +/- 25.3 per 10 HPF, P < 0.01). No difference in the CSI was observed in the four groups. Iron deficiency decreased the nNOS/beta-actin protein levels in the gallbladder and SO at 8 weeks (57.0 +/- 29.6 vs 7.4 +/- 2.6, gallbladder, P < 0.05) (98.4 +/- 39.7 vs 29.9 +/- 11.0, SO, P = 0.09), but these levels returned to baseline at 16 weeks. CONCLUSIONS: We conclude that iron deficiency acutely suppresses gallbladder and SO nNOS, and that compensatory mechanisms return nNOS to baseline levels while cholesterol crystal formation increases over time.


Asunto(s)
Anemia Ferropénica/metabolismo , Vesícula Biliar/enzimología , Óxido Nítrico Sintasa/metabolismo , Esfínter de la Ampolla Hepatopancreática/enzimología , Animales , Bilis/química , Western Blotting , Peso Corporal , Colelitiasis/metabolismo , Colesterol/química , Colesterol/metabolismo , Cristalización , Regulación hacia Abajo , Femenino , Hemoglobinas , Hierro de la Dieta/farmacología , Óxido Nítrico Sintasa/análisis , Óxido Nítrico Sintasa de Tipo I , Sciuridae
16.
J Gastrointest Surg ; 5(4): 393-9; discussion 399-400, 2001.
Artículo en Inglés | MEDLINE | ID: mdl-11985981

RESUMEN

Intestinal motility disorders are more common in women of childbearing age who are prone to iron deficiency anemia. The neurotransmitters nitric oxide (NO) and acetylcholine (ACh) play a key role in ileal smooth muscle relaxation and contraction, respectively. Iron-containing heme is known to be a cofactor for nitric oxide synthase (NOS), the enzyme responsible for NO production. Therefore we tested the hypothesis that iron deficiency would downregulate ileal NOS activity without affecting the ileum's response to ACh. Twelve adult female prairie dogs were fed either an iron-supplemented (Fe+) (200 ppm) (n = 6) or an iron-deficient (Fe-) (8 ppm) (n = 6) diet for 8 weeks. Ileal circular muscle strips were harvested to measure responses to ACh and electrical field stimulation. Under nonadrenergic noncholinergic (NANC) conditions, Nomega-nitro-L-arginine (L-NNA), an NOS inhibitor, and VIP(10-28), a vasoactive intestinal peptide (VIP) inhibitor, were added prior to electrical field stimulation. NANC inhibitory responses are expressed as a percentage of optimal relaxation from EDTA. The excitatory response to ACh was similar in both groups (1.1 +/- 0.3 N/cm(2) vs. 1.5 +/- 0.3 N/cm(2), P = 0.45). The inhibitory response to electrical field stimulation under NANC conditions was greater in the Fe+ group (34.7 +/- 2.9%) compared to the Fe- group (23.9 +/- 3.2%; P<0.01). L-NNA eliminated the inhibitory response in the Fe+ group (0.02 +/- 0.02%) but not in the Fe- group (8.38 +/- 2.15%; P <0.01). VIP(10-28) led to greater relaxation in the Fe+ animals (45.8 +/- 6.6%) than in the Fe- animals (23.4 +/- 5.8%; P <0.05). Both L-NNA and VIP(10-28) had no inhibitory response (0.02 +/- 0.02%) in the Fe+ animals, whereas the Fe- animals had some residual inhibition (2.54 +/- 1.04%; P <0.05). These data suggest that ileal NANC relaxation is due to NOS and that iron deficiency results in (1) decreased NANC relaxation, (2) a compensatory relaxation due to a non-NOS, non-VIP mechanism, and (3) a normal excitatory response. We conclude that iron deficiency suppresses ileal NOS activity.


Asunto(s)
Anemia Ferropénica/metabolismo , Íleon/enzimología , Óxido Nítrico Sintasa/metabolismo , Acetilcolina/farmacología , Animales , Western Blotting , Regulación hacia Abajo , Estimulación Eléctrica , Inhibidores Enzimáticos/farmacología , Femenino , Humanos , Íleon/fisiología , Músculo Liso/enzimología , Músculo Liso/fisiología , Nitroarginina/farmacología , Fragmentos de Péptidos/farmacología , Receptores de Péptido Intestinal Vasoactivo/antagonistas & inhibidores , Sciuridae , Péptido Intestinal Vasoactivo/farmacología
18.
JPEN J Parenter Enteral Nutr ; 24(2): 81-8, 2000.
Artículo en Inglés | MEDLINE | ID: mdl-10772187

RESUMEN

BACKGROUND: Intestinal adaptation after loss of functional small bowel surface area is characterized by cellular hyperplasia and increased absorptive function. Interventions to enhance the adaptive response are needed to decrease the morbidity and mortality associated with short bowel syndrome. Retinoic acid was shown to stimulate crypt cell proliferation in the adapting remnant rat ileum by 6 hours after resection. Thus, vitamin A, which is required for normal epithelial cell proliferation and differentiation and which can modulate programmed cell death, may play an important role in the adapting intestine. On the basis of these observations, the effects of vitamin A deficiency on intestinal morphology, epithelial cell proliferation, and apoptosis in the adapting intestine after resection were investigated. METHODS: Weanling male Sprague-Dawley rats fed either a vitamin A-deficient or -sufficient diet for 58 days underwent 70% proximal small bowel resection. The deficient rats were divided into cohorts that were either maintained on the experimental diet after surgery or replenished with vitamin A 20 hours before surgery and switched to the control diet after surgery. RESULTS: Ten days after resection, vitamin A-deficient rats exhibited a markedly blunted adaptive response. The adaptive increase in villus height and crypt depth was absent in the deficient rats. However, adaptive increases in crypt cell proliferation were not attenuated by vitamin A deficiency, and there were no differences in apoptotic indices. CONCLUSIONS: Vitamin A deficiency inhibits the adaptive response to partial small bowel resection, supporting a role for vitamin A in the adaptive process. Changes in cellular proliferation or programmed cell death are not sufficient to account for this inhibition. This model system will be useful for examining the role of other mechanisms, such as changes in cell-cell and cell-extracellular matrix interactions, and rates of epithelial cell migration and cell extrusion.


Asunto(s)
Adaptación Fisiológica , Intestino Delgado/fisiología , Deficiencia de Vitamina A/fisiopatología , Vitamina A/farmacología , Animales , Apoptosis , Peso Corporal , División Celular , Cromatografía Líquida de Alta Presión , Dieta , Ingestión de Alimentos , Intestino Delgado/efectos de los fármacos , Intestino Delgado/cirugía , Hígado/efectos de los fármacos , Hígado/metabolismo , Masculino , Ratas , Ratas Sprague-Dawley , Vitamina A/sangre
19.
J Surg Res ; 90(1): 26-31, 2000 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-10781371

RESUMEN

BACKGROUND: Iron deficiency has been demonstrated in the prairie dog to result in cholesterol crystal formation and altered biliary motility. Gallbladder filling and emptying are influenced by both inhibitory and excitatory stimuli, with nitric oxide (NO) playing a key role in normal relaxation. Iron is a cofactor for nitric oxide synthase. Therefore, we tested the hypothesis that iron deficiency would result in diminished levels of gallbladder neuronal nitric oxide synthase (nNOS) but would not influence the gallbladder's response to excitatory stimuli. MATERIALS AND METHODS: Twenty adult female prairie dogs were fed either an iron-supplemented (Fe(+)) (200 ppm) control diet (n = 10) or an iron-deficient (Fe-) (8 ppm) diet (n = 10) for 8 weeks. Fasting gallbladder volume was measured. Gallbladder muscle strips were harvested for response to excitatory stimuli and measurement of nNOS protein levels by Western blotting. Muscle strip response to a spectrum of doses of cholecystokinin, acetylcholine, and electrical field stimuli was determined, and the areas under the response curves were calculated. RESULTS: Gallbladder volume increased in the iron-deficient prairie dogs compared with the iron-supplemented group (1.45 +/- 0.27 mL vs 0.80 +/- 0.13 mL, P < 0.05). Iron deficiency diminished the ratio of gallbladder nNOS to beta-actin protein levels (0.05 +/- 0.01 vs 3.48 +/- 1.02, P < 0.05) but resulted in a normal response to excitatory stimuli. CONCLUSIONS: We conclude that diminished gallbladder neuronal nitric oxide synthase contributes to the gallbladder stasis that occurs with iron deficiency. This phenomenon may contribute to the increased incidence of gallstones in premenopausal women.


Asunto(s)
Vesícula Biliar/enzimología , Deficiencias de Hierro , Óxido Nítrico Sintasa/metabolismo , Animales , Western Blotting , Peso Corporal , Colelitiasis/etiología , Colelitiasis/metabolismo , Colesterol/metabolismo , Perros , Femenino , Vesícula Biliar/efectos de los fármacos , Vesícula Biliar/fisiología , Contracción Muscular/efectos de los fármacos , Óxido Nítrico Sintasa de Tipo I , Sincalida/farmacología , Transferrina/metabolismo
20.
Surg Neurol ; 52(3): 246-50; discussion 250-1, 1999 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-10511081

RESUMEN

BACKGROUND: Monoventricular hydrocephalus is usually treated with extrathecal shunting. However, today endoscopic fenestration of the septum pellucidum seems to be a very useful and less invasive technique. METHODS: Five patients with monoventricular hydrocephalus have been treated with neuroendoscopic techniques. In three cases with an excluded lateral ventricle due to contralateral shunt overdrainage, the normal-sized ventricle was first cannulated and fenestration of the septum pellucidum from the normal to the enlarged lateral ventricle was performed. RESULTS: Complete remission of intracranial hypertension symptoms and decrease in size of the enlarged ventricle were observed in all five patients. CONCLUSIONS: Endoscopic fenestration of the septum pellucidum is the technique of choice for treating monoventricular hydrocephalus. We advise first cannulating the normal lateral ventricle and then performing a septostomy from it to the enlarged ventricle. This approach allows one to easily recognize the protruding septum pellucidum and perform fenestration without difficulty using a direct trajectory. In exceptional cases of choroid plexus cyst obstructing one foramen of Monro, fenestration of the cyst wall is sufficient.


Asunto(s)
Endoscopía , Hidrocefalia/cirugía , Procedimientos Neuroquirúrgicos/métodos , Tabique Pelúcido/cirugía , Adolescente , Ventrículos Cerebrales/patología , Niño , Preescolar , Endoscopía/métodos , Femenino , Humanos , Hidrocefalia/diagnóstico , Hidrocefalia/diagnóstico por imagen , Imagen por Resonancia Magnética , Masculino , Estudios Retrospectivos , Tabique Pelúcido/diagnóstico por imagen , Tomografía Computarizada por Rayos X , Resultado del Tratamiento
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