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1.
Childs Nerv Syst ; 37(4): 1127-1135, 2021 04.
Artículo en Inglés | MEDLINE | ID: mdl-33185712

RESUMEN

PURPOSE: To assess the functional outcome in school-age children shunted in the neonatal period due to post-hemorrhagic hydrocephalus (PHH), using the HOQ-Spanish version (HOQ-sv), and to analyze predictors of quality of life in this group. METHODS: A cross-sectional study was performed between 2015 and 2018. Parents of pediatric patients with PHH attending our neurosurgery outpatient clinic were invited to complete the HOQ-sv and to enroll in the study. Clinical variables regarding the patients' neonatal course and surgical outcome were recorded. A descriptive analysis was done, and independent variables related to the HOQ scores were studied in univariate and multivariate analyses with regression trees. RESULTS: The study comprised a total of 52 patients. The mean overall HOQ score was 0.67 (on a scale from 0 [worse] to 1 [best]). The quality of life for the PHH children at school age was related to perinatal factors (gestational age at birth, time until shunt surgery, length of hospitalization at the time of shunt implantation, and comorbidity), shunt complications (symptomatic overdrainage, number of shunt revisions, and shunt revisions related to infection during the first year after treatment), and clinical background (seizures, spasticity, Gross Motor Function Classification System level or visual impairment). CONCLUSION: HOQ dimension scores in school-age children shunted due to PHH in our center were similar to those of referral centers for other etiologies of pediatric hydrocephalus. Future goals should be the prevention of complications related to worse outcomes at the time of diagnosis and to try to improve shunt performance later.


Asunto(s)
Hidrocefalia , Calidad de Vida , Niño , Estudios Transversales , Edad Gestacional , Humanos , Hidrocefalia/etiología , Hidrocefalia/cirugía , Recién Nacido , Instituciones Académicas
2.
Sensors (Basel) ; 16(2): 187, 2016 Feb 02.
Artículo en Inglés | MEDLINE | ID: mdl-26848663

RESUMEN

The possibility of a new design concept for dual spin crossover based sensors for concomitant detection of both temperature and pressure is presented. It is conjectured from numerical results obtained by mean field approximation applied to a Ising-like model that using two different spin crossover compounds containing switching molecules with weak elastic interactions it is possible to simultaneously measure P and T. When the interaction parameters are optimized, the spin transition is gradual and for each spin crossover compounds, both temperature and pressure values being identified from their optical densities. This concept offers great perspectives for smart sensing devices.

3.
Sensors (Basel) ; 15(2): 2388-98, 2015 Jan 22.
Artículo en Inglés | MEDLINE | ID: mdl-25621610

RESUMEN

We have investigated the suitability of using the 1D spin crossover coordination polymer [Fe(4-(2'-hydroxyethyl)-1,2,4-triazole)3]I2∙H2O, known to crossover around room temperature, as a pressure sensor via optical detection using various contact pressures up to 250 MPa. A dramatic persistent colour change is observed. The experimental data, obtained by calorimetric and Mössbauer measurements, have been used for a theoretical analysis, in the framework of the Ising-like model, of the thermal and pressure induced spin state switching. The pressure (P)-temperature (T) phase diagram calculated for this compound has been used to obtain the P-T bistability region.

4.
Med Oral Patol Oral Cir Bucal ; 19(5): e444-50, 2014 Sep 01.
Artículo en Inglés | MEDLINE | ID: mdl-24608218

RESUMEN

OBJECTIVES: High doses of chemotherapy generate DNA damage in patients undergoing bone marrow transplantation (BMT), due to the production of reactive oxygen species (ROS). In order to evaluate the local defensive effectiveness of the patient undergoing BMT, the concentrations of the antioxidants superoxide dismutase (SOD) and uric acid (UA) were measured in saliva. STUDY DESIGN: Basal saliva samples were collected from 20 patients undergoing BMT at the Oncology Department, Sanatorio Allende (Córdoba), in the stages: initial, prior to conditioning therapy (I); middle: 7 to 10 days after BMT (M) and final stage, 30 days after discharge from isolation (F). SOD levels were determined using a RANDOX kit (RANSOD superoxide dismutase manual), and for uric acid enzymatic UOD / PAP spectrophotometric method, ( Trinder Color Kit , Wiener Lab) was used. RESULTS: 85% of the patients developed oral mucositis. SOD concentration in the M stage was significantly higher (p<0.01) compared with stage I, and it reversed in stage F. UA concentration was significantly lower (p<0.001) in stage M compared with stage I, and in stage F it recovered the initial values. CONCLUSIONS: SOD increase in stage M coincided with the appearance of mucositis, which could be interpreted as a defensive mechanism of saliva against oxidative stress produced by chemotherapy. UA decrease in stage M would favour the development of higher degrees of mucositis.


Asunto(s)
Mucositis/metabolismo , Complicaciones Posoperatorias/metabolismo , Saliva/química , Superóxido Dismutasa/análisis , Ácido Úrico/análisis , Adulto , Anciano , Trasplante de Médula Ósea , Femenino , Humanos , Estudios Longitudinales , Masculino , Persona de Mediana Edad
5.
J Oral Pathol Med ; 42(10): 788-92, 2013 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-23647127

RESUMEN

This work presents a chemical and morphological analysis of samples of saliva taken from patients who were under treatment with intravenous chemotherapy with 5-fluorouracil and leucovorin calcium. Samples of saliva were extracted from fifteen patients during the three stages of the treatment: The initial stage (previous to the chemotherapy), the intermediate stage (during the chemotherapy), and the final stage (twenty-one days after finishing the treatment). An amount of 50 µl was collected in each visit. Chemical contrast images were taken by means of scanning electron microscopy, and X-ray characteristic spectra were obtained from all the studied samples by using an energy dispersive system from all the studied samples. Images that correspond to the intermediate stage showed important differences with respect to the initial and final stages. In addition, X-ray spectra provided information about the present elements in saliva and their relative abundance allowed us to determine variations in the chemical composition. The backscattered electron images and X-ray spectra from the intermediate stage showed clusters of crystals with fluorine content higher than those obtained in initial and final stages. This fact probably indicates the passage of metabolites of 5-fluorouracil and leucovorin calcium from the plasma to the oral cavity. This finding enhances the hypothesis proposed by other authors about the secondary effects of the drugs on the stomatognathic system such as oral mucositis, dysgeusia, and xerostomia with or without hyposalivation.


Asunto(s)
Antimetabolitos Antineoplásicos/uso terapéutico , Fluorouracilo/uso terapéutico , Leucovorina/uso terapéutico , Saliva/química , Complejo Vitamínico B/uso terapéutico , Administración Intravenosa , Adulto , Antimetabolitos Antineoplásicos/administración & dosificación , Calcio/análisis , Carcinoma/tratamiento farmacológico , Neoplasias del Colon/tratamiento farmacológico , Cristalografía , Microanálisis por Sonda Electrónica , Femenino , Flúor/análisis , Fluorouracilo/administración & dosificación , Estudios de Seguimiento , Humanos , Leucovorina/administración & dosificación , Masculino , Microscopía Electrónica de Rastreo , Persona de Mediana Edad , Mucosa Bucal/efectos de los fármacos , Mucosa Bucal/metabolismo , Saliva/efectos de los fármacos , Espectrometría por Rayos X , Estomatitis/inducido químicamente , Estomatitis/metabolismo , Complejo Vitamínico B/administración & dosificación
6.
Neurocirugia (Astur : Engl Ed) ; 34(1): 32-39, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-36623891

RESUMEN

Craniopharyngiomas are benign epithelial tumors which may very occasionally recur in ectopic locations. We present two cases of ectopic recurrence, both in the posterior fossa, and provide a review of the literature with basic statistics. Two patients admitted to our institution with posterior fossa lesions underwent gross total resection. Pathological studies showed adamantinomatous craniopharyngiomas (ACP). Both patients had a prior history of suprasellar tumor surgery. We also reviewed the related data and undertook a basic statistical analysis. We found 67 cases of ectopic recurrent craniopharyngioma (including the present cases): 51 cases were adamantinomatous (76%), 6 papillary (9%) and 10 unknown (15%). 18 cases occurred in the posterior fossa, all of them diagnosed as the ACP subtype. The intervals until recurrence were 15.15 years for posterior fossa recurrences and 5.75 years for supratentorial cases. Student t test showed significant differences in time to recurrence (p 0.002). Gross total resection was performed in 53 cases (79%), subtotal resection+radiotherapy in 3 (5%) and 11 (16%) cases were treated with other options. Ectopic recurrence is a rare but possible event. Those in the posterior fossa may appear later than in the supratentorial space. ACP is likely to be the most common subtype in these cases, possibly due to its more aggressive behavior compared to the papillary subtype. Long term follow-up should be performed to detect ectopic recurrences. Ectopic recurrences are often surgically accessible and gross total resection should be achieved.


Asunto(s)
Neoplasias Encefálicas , Craneofaringioma , Neoplasias Hipofisarias , Humanos , Craneofaringioma/diagnóstico por imagen , Craneofaringioma/cirugía , Neoplasias Hipofisarias/diagnóstico por imagen , Neoplasias Hipofisarias/cirugía , Recurrencia
7.
Sensors (Basel) ; 12(4): 4479-92, 2012.
Artículo en Inglés | MEDLINE | ID: mdl-22666041

RESUMEN

Iron(II) spin crossover molecular materials are made of coordination centres switchable between two states by temperature, pressure or a visible light irradiation. The relevant macroscopic parameter which monitors the magnetic state of a given solid is the high-spin (HS) fraction denoted n(HS), i.e., the relative population of HS molecules. Each spin crossover material is distinguished by a transition temperature T(1/2) where 50% of active molecules have switched to the low-spin (LS) state. In strongly interacting systems, the thermal spin switching occurs abruptly at T(1/2). Applying pressure induces a shift from HS to LS states, which is the direct consequence of the lower volume for the LS molecule. Each material has thus a well defined pressure value P(1/2). In both cases the spin state change is easily detectable by optical means thanks to a thermo/piezochromic effect that is often encountered in these materials. In this contribution, we discuss potential use of spin crossover molecular materials as temperature and pressure sensors with optical detection. The ones presenting smooth transitions behaviour, which have not been seriously considered for any application, are spotlighted as potential sensors which should stimulate a large interest on this well investigated class of materials.

8.
Acta Odontol Latinoam ; 25(3): 262-8, 2012.
Artículo en Inglés | MEDLINE | ID: mdl-23798072

RESUMEN

One of the main clinical problems during chemotherapy is the occurrence of severe systemic toxicities, including those related to the stomatognathic system, which contribute to reducing the patient's quality of life. The most frequent oral complications are mucositis, dysgeusia, inflammation, gingival bleeding and decreased salivary flow or hyposalivation, a factor that predisposes to xerostomia, and other local complications that alter the homeostasis of the system. The purpose of this study was to evaluate the functional activity of salivary glands in Wistar rats subject to chemotherapy by measuring salivary flow, glycogen levels and glandular tissue response to autonomic nervous system agonists. Five experimental groups were used: 1) Control group fed "ad libitum"; 2) 5-fluorouracil (20 mg/kg body weight); 3) Calcium leucovorin (10 mg/kg body weight); 4) 5-fluorouracil + calcium leucovorin (20 and 10 mg/kg, respectively) by intraperitoneal injection for five consecutive days and 5) control with paired diet. Groups 1 and 5 did not receive drugs. Treatment with fluorouracil + leucovorin produced an increase in stimulated salivary flow and a higher response to increasing doses of beta agonists compared to other experimental groups. In both groups treated with cytostatic drugs, blocking of glycogen consumption at the end of the experimental period was observed. Our work suggests that salivary secretion may be affected by a dual mechanism: the first would be toxicity induced by 5-FU, which would cause depression of the process of glucose utilization. The second mechanism would affect the sympathetic autonomic reflex arc. In this instance, the synergistic action of 5-FU + LV would have a negative effect on the nerve activity with a reduction of salivary secretion. This would explain the hyposalivation, cited by several authors in patients undergoing the 5-FU + LV scheme in the treatment of colon carcinoma.


Asunto(s)
Citostáticos/farmacología , Fluorouracilo/farmacología , Leucovorina/farmacología , Glándula Submandibular/efectos de los fármacos , Glándula Submandibular/fisiopatología , Animales , Masculino , Ratas , Ratas Wistar
9.
J Clin Med ; 10(16)2021 Aug 17.
Artículo en Inglés | MEDLINE | ID: mdl-34441916

RESUMEN

Although shunt overdrainage is a well-known complication in hydrocephalus management, the problem has been underestimated. Current literature suggests that the topic requires more examination. An insight into this condition is limited by a lack of universally agreed-upon diagnostic criteria, heterogeneity of published series, the multitude of different management options and misunderstanding of relationships among pathophysiological mechanisms involved. We carried out a review of the literature on clinical, radiological, intracranial pressure (ICP), pathophysiological and treatment concepts to finally propose an integrative model. Active prophylaxis and management are proposed according to this model based on determination of pathophysiological mechanisms and predisposing factors behind each individual case. As pathophysiology is progressively multifactorial, prevention of siphoning with gravitational valves or antisiphon devices is mandatory to avoid or minimize further complications. Shunt optimization or transferal and neuroendoscopy may be recommended when ventricular collapse and cerebrospinal fluid isolation appear. Cranial expansion may be useful in congenital or acquired craniocerebral disproportion and shunting the subarachnoid space in communicating venous hydrocephalus and idiopathic intracranial hypertension.

10.
Rev Fac Cien Med Univ Nac Cordoba ; 78(4): 384-390, 2021 12 28.
Artículo en Español | MEDLINE | ID: mdl-34962731

RESUMEN

OBJECTIVE: High doses of chemotherapy used prior to bone marrow transplantation (BMT) promote severe changes in the stomatognathic system. The objective of the present work consisted in evaluating some functional, immunological and oxidative stress markers in saliva of these patients. METHODS: A longitudinal observational study was carried out on 22 patients admitted to the Bone Marrow Transplant Unit of the Oncohematology Service of the Sanatorio Allende between March 2019 and February 2020. Basal saliva collection was carried out in the initial stage (I ) prior to isolation and middle stage (M) 14 days after conditioning therapy and transplantation. The concentration of uric acid (UA), superoxide dismutase (SOD), malondialdehyde (MDA), salivary alpha amylase, secretory immunoglobulin A (Ig As), lactoferrin, ceruloplasmin and urea were analyzed. RESULTS: In (M) the levels of SOD and MAD increased significantly compared to (I) (p <0.01). The concentration of salivary alpha amylase, Ig As, lactoferrin and uric acid was significantly lower in (M) compared to (I ) p <0.0001, p <0.01, p <0.0001, p <0.02 respectively. Ceruloplasmin and Urea did not show variations during treatment. CONSLUSION: In the present study, a decrease in the defensive capacity of saliva was observed as a consequence of a reduction in the concentration of Ig As and lactoferrin. The increase in SOD in (M) could be interpreted as a defense mechanism of saliva against oxidative stress produced by chemotherapy. The decrease in uric acid in stage (M) could allow the worsening of mucositis. The synthesis and release of amylase was affected by treatment with cytostatic drugs.


OBJETIVO: Altas dosis de quimioterapia utilizadas previo al trasplante de médula ósea (TMO) pueden promover severos cambios en el sistema estomatognático. El objetivo consistió en evaluar algunos marcadores funcionales, inmunológicos y de estrés oxidativo en saliva de pacientes sometidos a dicho tratamiento. MÉTODOS: Estudio observacional longitudinal en 22 pacientes de la Unidad de trasplante de Médula Ósea del Servicio de Oncohematología del Sanatorio Allende. Se efectuó recolección de saliva basal en etapa inicial (I) previa al aislamiento y etapa media (M) 14 días posteriores a la terapia de acondicionamiento y trasplante. Se analizó la concentración de ácido úrico (AU), superóxido dismutasa (SOD), malondialdehido (MDA), alfa amilasa salival, inmunoglobulina A secretora (Ig As), lactoferrina, ceruloplasmina y urea. RESULTADOS: En (M) los niveles de SOD y MAD aumentaron significativamente respecto de (I) (p< 0.01). La concentración de  alfa amilasa salival, Ig As, lactoferrina y ácido úrico fue significativamente menor en (M) respecto de ( I ) p < 0.0001, p < 0.01, p < 0.0001, p <0.02 respectivamente. Ceruloplasmina y Urea no mostraron variaciones. CONCLUSIÓN: se observó una disminución de la capacidad defensiva de la saliva como consecuencia de una reducción de la concentración de Ig As y lactoferrina. El incremento de SOD en (M) podría interpretarse como un mecanismo de defensa de la saliva contra el estrés oxidativo producido por la quimioterapia. La disminución de ácido úrico en la etapa (M) podría favorecer el agravamiento de mucositis.  La síntesis y liberación de amilasa fue afectada por el tratamiento con citostáticos.


Asunto(s)
Trasplante de Médula Ósea , Saliva , Biomarcadores , Humanos , Estrés Oxidativo , Superóxido Dismutasa/metabolismo
11.
Phys Chem Chem Phys ; 12(23): 6107-23, 2010 Jun 21.
Artículo en Inglés | MEDLINE | ID: mdl-20390192

RESUMEN

We report a thorough investigation of the absorption spectra of the cis and trans isomers of the 4-styrylpyridine photoswitch based on TDDFT calculations. The spectra of both isomers were analysed first from the results of excitation calculations performed on their optimised geometries. The main absorption band of the cis isomer is thus predicted to be due to the S(0)--> S(1) and S(0)--> S(2) transitions, while the main absorption band of the trans isomer is predicted to originate exclusively from the S(0)--> S(1) transition. The convolution of the calculated oscillator strengths with Gaussians helped mimic the broadening of the electronic transitions. However, it proved necessary to use Gaussians with a large full width at half maximum of 5000 cm(-1); and, compared to experiment, the calculated main absorption bands of the two isomers are significantly red-shifted and far too symmetric. Consequently, as required for the detailed analysis of the finite-temperature absorption spectrum of a molecule as flexible as 4-styrylpyridine, the influence of the thermal fluctuations has been taken into account by calculating the spectra as time averages over Car-Parrinello molecular dynamics trajectories. For both isomers, this led to a noticeable improvement in the relative positions of the calculated and experimental main absorption bands, and the asymmetry of the calculated bands brings them in better agreement with the experimental ones. Furthermore, these last results show that, actually, the S(0)--> S(1) and S(0)--> S(2) transitions both contribute significantly to the finite-temperature main absorption bands of the two isomers. Finally, in order to also take the vibrational broadening into account, the Franck-Condon factors of the relevant vibrations were calculated within the displaced harmonic oscillator approximation. By thus taking both the thermal and the vibrational broadening into account for the calculation of the absorption bands, the agreement between experiment and theory could be further improved.

12.
Med Oral Patol Oral Cir Bucal ; 15(3): e437-40, 2010 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-20038904

RESUMEN

UNLABELLED: The aim of this study was to assess changes in salivary electrolyte flow and composition and the presence of anti-Ro/SSA and anti-La/SSB serum and saliva antibodies and their implications for the non-invasive diagnosis of SS. STUDY DESIGN: 73 patients were studied, divided into the following experimental groups: primary Sjögren syndrome (SSp) (n=15), secondary SS (SSs) (n=17), dry mouth, dry eye without Sjögren's syndrome (BO) (n=20) and healthy controls (C) (n=21). We conducted a baseline assessment of salivary flow and saliva sampling for the measurement of sodium, chlorine, potassium, calcium and phosphate electrolytes, and the determination of anti-Ro/SSA and La/SSB antibodies; a serum sampling was made to assess antibody positivity. RESULTS: Salivary flow in SSp, SSs and BO was significantly lower (p<0.001) relative to C. The salivary composition of SS showed an increase of inorganic components. Anti-Ro/SSA and anti-La/SSB antibodies occurred more frequently in serum and saliva in SS patients compared with BO and C, with higher frequency of positivity in serum compared with saliva. CONCLUSION: Our results suggest new tools that could aid the non-traumatic diagnosis of the origin of hyposalivation.


Asunto(s)
Anticuerpos Antinucleares/análisis , Electrólitos/análisis , Saliva/química , Síndrome de Sjögren/diagnóstico , Anticuerpos Antinucleares/sangre , Femenino , Humanos , Masculino , Persona de Mediana Edad , Síndrome de Sjögren/sangre
13.
Inorg Chem ; 48(16): 7838-52, 2009 Aug 17.
Artículo en Inglés | MEDLINE | ID: mdl-19618904

RESUMEN

One-dimensional (1D) coordination polymers of formula [Fe(NH(2)trz)(3)]A.nH(2)O, {A = TiF(6)(2-), n = 0.5 (1) and n = 1 (2); A = ZrF(6)(2-), n = 0.5 (3) and n = 0 (4); A = SnF(6)(2-), n = 0.5 (5) and n = 1 (6); A = TaF(7)(2-), n = 3 (7) and n = 2.5 (8); A = GeF(6)(2-), n = 1 (9) and n = 0.5 (10), NH(2)trz = 4-amino-1,2,4-triazole} have been synthesized, fully characterized, and their spin crossover behavior carefully studied by SQUID magnetometry, Mossbauer spectroscopy, and differential scanning calorimetry. These materials display an abrupt and hysteretic spin transition around 200 K on cooling, as well as a reversible thermochromic effect. Accurate spin transition curves were derived by (57)Fe Mossbauer spectroscopy considering the corrected f factors for the high-spin and low-spin states determined employing the Debye model. The unusual hysteresis width of 3 (28 K), was attributed to a dense hydrogen bonding network involving the ZrF(6)(2-) counteranion and the 1D chains, an organization which is also revealed in [Cu(NH(2)trz)(3)]ZrF(6).H(2)O (11). Trinuclear spin crossover compounds of formula [Fe(3)(NH(2)trz)(10)(H(2)O)(2)](SbF(6))(6).S {S = 1.5CH(3)OH (12), 0.5C(2)H(5)OH (13)} were also obtained. A structural property relationship was derived between the volume of the inserted counteranion and the transition temperature T(1/2) of the 1D chains. Two linear size regimes were identified for monovalent anions (0.04 or= 0.11 nm(3)) with saturation around T(1/2) = 200 K. These characteristics allowed us to derive an anion based database that is of interest for the prediction of the transition temperature of such functional switchable materials. Diffuse reflectivity measurements under hydrostatic pressure for 3,4 combined with calorimetric data allow an estimation of the electrostatic pressure between cationic chains and counteranions in the crystal lattice of these materials. The chain length distribution that ranges between 1 and 4 nm was also derived.

14.
Med Oral Patol Oral Cir Bucal ; 14(3): E108-13, 2009 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-19242388

RESUMEN

UNLABELLED: Several studies have shown how cytostatics may cause hypofunction of salivary glands but failed to elucidate any potentially related side effects. Keeping in mind the sialochemical assistance and the role of saliva on the homeostasis of the stomatognathic system, the aim of this study was to establish potential gland disorders in patients submitted to 5- Fluorouracil (5-Fu) and Leucovorin calcium (LV) as well as their correlation with certain oral health disorders that diminish the quality of life. MATERIALS AND METHODS: the focus of this research was observational and longitudinal. Twenty-five patients diagnosed with colon cancer at an initial, intermediate and late phase submitted to specifically devised therapy were assessed. Clinical history, oral health indexes and basal or stimulated saliva samples were recorded. RESULTS: Basal and stimulated flow dropped in the intermediate stage. Stimulated saliva pH decreased during treatment. On basal saliva, urea, sodium and potassium rose during the intermediate phase. Löe and Silness rates as well as simplified bleeding increased during therapy but reverted by the end of the treatment. Depth index of the vestibular gingival sulcus rose during the intermediate phase but did not return. CONCLUSION: This treatment caused functional salivary gland disorders as evidenced by basal and stimulated hyposialia, and acidification of stimulated saliva pH during the intermediate phase. Increase in basal urea may be due to proteic catabolism arising from plasma or glands. Variation in Na+ and K+ of basal saliva concentrates might be assumed as a possible duct disorder. Recovery of bleeding and Löe and Silness rates may point to a transient inflammatory effect associated to a decrease in salivary flow. Increase in the depth rates of the periodontal vestibular sulcus could be correlated with a higher risk of periodontal disease.


Asunto(s)
Antimetabolitos Antineoplásicos/efectos adversos , Neoplasias del Colon/tratamiento farmacológico , Fluorouracilo/efectos adversos , Leucovorina/efectos adversos , Enfermedades de las Glándulas Salivales/inducido químicamente , Complejo Vitamínico B/efectos adversos , Adulto , Anciano , Antimetabolitos Antineoplásicos/administración & dosificación , Femenino , Fluorouracilo/administración & dosificación , Humanos , Infusiones Intravenosas , Leucovorina/administración & dosificación , Estudios Longitudinales , Masculino , Persona de Mediana Edad , Complejo Vitamínico B/administración & dosificación , Adulto Joven
15.
Inorg Chem ; 47(17): 7577-87, 2008 Sep 01.
Artículo en Inglés | MEDLINE | ID: mdl-18672871

RESUMEN

The title compound [Fe (II)(L) 2][ClO 4] 2.C 7H 8 (L = 2-[3-(2'-pyridyl)pyrazol-1-ylmethyl]pyridine) has been isolated while attempting to grow single crystals of the spin-transition (continuous-type) compound [Fe (II)(L) 2][ClO 4] 2, published earlier ( Dalton Trans. 2003, 3392-3397). Magnetic susceptibility measurements, as well as Mossbauer and calorimetric investigations on polycrystalline samples of [Fe(L) 2][ClO 4] 2.C 7H 8 revealed the occurrence of an abrupt HS ( (5) T 2) <--> LS ( (1) A 1) transition with steep and narrow (2 K) hysteresis at approximately 232 K. The photomagnetic properties exhibit features typical for a broad distribution of activation energies, with relaxation curves in the shape of stretched exponentials. We performed a crystal structure determination of the compound at 120, 240, and 270 K. A noteworthy temperature-dependent behavior of the structural parameters was observed, in terms of disorder of both the anions and solvent molecules, leading to a strong thermal dependence of the strength and dimensionality of the interaction network. Additional data were obtained by diffuse reflectance measurements. We model and discuss the antagonistic effects of interactions and disorder by using a two-level cooperative mean-field approach which includes a distribution of barrier energies at the microscopic scale.

16.
J Phys Chem B ; 110(12): 5883-8, 2006 Mar 30.
Artículo en Inglés | MEDLINE | ID: mdl-16553394

RESUMEN

The molecular solid [Fe(II)L(2)](ClO(4))(2).CH(3)CN where L is 2,6-bis(3,5-dimethylpyrazol-1-ylmethyl)pyridine provides a stable high-spin (HS) state at low temperature. Photoexcitation and subsequent relaxation have been studied using light-induced excited state spin trapping [LIESST(H --> L)] in the 700-850 nm range, determination of T(LIESST), relaxation curves at different temperatures, and temperature dependence of the light-induced spin equilibrium under constant irradiation. The measured photoinduced population of the metastable low-spin (LS) state (<30%) was drastically limited by the concomitant L --> H photoprocess. The absence of static light-induced thermal hysteresis and the stretched exponential shape of the relaxation curves respectively revealed the absence of sizable interactions and a large spreading of the activation energies attributed to the ligand flexibility. The whole data set has been simulated using a linear rate equation, with a simplified correction for the bulk extinction of light in the powder sample.

17.
Artículo en Inglés | MEDLINE | ID: mdl-15970461

RESUMEN

Investigation on solvent-induced polymorphism in X-ray structures of 2-hydroxy-1,4-naphthoquinone (Lawsone) 1, is carried out. In protic methanol, 1 crystallizes in monoclinic space group P2(1)/c (1a) comprising of 2D hydrogen bonded network via cyclic dimers. In aprotic solvent such as acetone on the other hand, 1 exhibits orthorhombic space group Pna 2(1) (1b) and emerges with 1D catemeric chain. Solvent-induced topological isomerism of cyclic dimers and helical catemeric chains arising from (i) bifurcated intra- and inter molecular hydrogen bondings viz. O-H...O=C interactions between C(2) hydroxyl and C(1), C(4) carbonyls, (ii) C-H...O interactions viz. C(3)-H...O(1)C(1) have been discussed. A signal for radical in 1 at g = 2.0058 is signatured by EPR spectrum and it's oxime derivative viz. 2-hydroxy-4-naphthoquinone-1-oxime 2, in solid state shows biradical and monoradical formation with aggregation of dimer and monomer due to non-covalent hydrogen bonds. Zero field split parameters for 2 are estimated to be D = 215 G, Ex = 13 G, Ey = 47 G at 298 K. A half field signal at 77 K indicates triplet ground state. Frozen glass EPR of 2 resolves as regioregular dimeric-monomeric species showing hyperfine interactions with 1-oximino nitrogen in dimer A (14N) = 15.5 G].


Asunto(s)
Naftoquinonas/química , Oximas/química , Acetona/química , Cristalografía por Rayos X , Espectroscopía de Resonancia por Spin del Electrón , Metanol/química , Estructura Molecular , Solventes/química
18.
J. oral res. (Impresa) ; 8(5): 363-369, oct. 31, 2019. tab, graf
Artículo en Inglés | LILACS | ID: biblio-1248086

RESUMEN

Objective: Chemotherapy treatment against cancer produce systemic toxicities, among which are those related to important structures of the stomatognathic system and its functional activity. 5 Fluorouracil (5-FU) and cyclophosphamide (Cf) are drugs widely used in solid tumors and in bone marrow transplantation, respectively. The objective of this work was to evaluate the toxicity of these drugs regarding functional activity of the submandibular glands, by measuring the percentage of glycogen consumption in two experimental models. Material and Methods: 84 male Wistar rats aged three months were used, housed in individual cages, with controlled temperature and lighting and ad libitum diet. They were divided into four experimental groups: 1) Control (C); 2) Treated with 5-FU+leucovorin (LV) at 20 and 10mg/Kg of body weight respectively for five consecutive days; 3) treated with Cf i.p. at 50mg/Kg of body weight for two consecutive days; and 4) rats with paired feeding (PF): for five and two days respectively, the amount administered resulted from the average of the ingested food of groups 2 and 3. Both submandibular glands were excised. The submandibular glycogen concentration was analyzed at initial time (t0) and after 60 minutes of mechanical stimulation (t60). Results: the average variation changed significantly between time 0 and 60 in the groups C and PF. (p-value=0.0001), the 5-FU + LV treatment group had an average concentration higher at t0 than groups C and PF, without significant consumption at T60. While group Cf showed a lower average concentration at time 0 with respect to groups C and PF, without significant consumption at T60. Conclusion: 5-FU+LV and Cf affect the metabolism of carbohydrates, decreasing the use of glycogen as a metabolic substrate. In the present experimental model, the toxicity of these drugs affected the functional activity of the submandibular gland.


Objetivo: el tratamiento de quimioterapia contra el cáncer produce toxicidades sistémicas, entre las que se encuentran las relacionadas con estructuras importantes del sistema estomatognático y su actividad funcional. El 5-fluorouracilo (5-FU) y la ciclofosfamida (Cf ) son fármacos ampliamente utilizados en tumores sólidos y en trasplantes de médula ósea, respectivamente. El objetivo de este trabajo fue evaluar la toxicidad de estos fármacos con respecto a la actividad funcional de las glándulas submandibulares, midiendo el porcentaje de consumo de glucógeno en dos modelos experimentales. Material y Métodos: se utilizaron 84 ratas Wistar machos de tres meses de edad, alojadas en jaulas individuales, con temperatura e iluminación controladas y dieta ad libitum. Se dividieron en cuatro grupos experimentales: 1) Control (C); 2) Tratados con 5-FU+leucovorina (LV) a 20 y 10mg/Kg de peso corporal, respectivamente, durante cinco días consecutivos; 3) tratados con Cf i.p. a 50mg/Kg de peso corporal durante dos días consecutivos; y 4) ratas con alimentación por parejas (PF): durante cinco y dos días respectivamente, la cantidad administrada resultó del promedio de los alimentos ingeridos de los grupos 2 y 3. Ambas glándulas submandibulares fueron extirpadas. La concentración de glucógeno submandibular se analizó en el momento inicial (t0) y después de 60 minutos de estimulación mecánica (t60). Resultados: la variación promedio cambió significativamente entre el tiempo 0 y 60 en los grupos C y PF. (p=0,0001), el grupo de tratamiento 5-FU+LV tuvo una concentración promedio más alta en t0 que los grupos C y PF, sin un consumo significativo en T60. Mientras que el grupo Cf mostró una concentración promedio más baja en el tiempo 0 con respecto a los grupos C y PF, sin un consumo significativo en T60. Conclusión: 5-FU + LV y Cf afectan el metabolismo de los carbohidratos, disminuyendo el uso de glucógeno como sustrato metabólico. En el presente modelo experimental, la toxicidad de estos medicamentos afectó la actividad funcional de la glándula submandibular.


Asunto(s)
Animales , Ratas , Glándula Submandibular/fisiología , Ciclofosfamida/efectos adversos , Fluorouracilo/efectos adversos , Glucógeno/metabolismo , Ratas Wistar , Ciclofosfamida/uso terapéutico , Fluorouracilo/uso terapéutico , Antineoplásicos
19.
Neurocirugía (Soc. Luso-Esp. Neurocir.) ; 34(1): 32-39, ene.-feb. 2023. ilus, tab
Artículo en Inglés | IBECS (España) | ID: ibc-214411

RESUMEN

Craniopharyngiomas are benign epithelial tumors which may very occasionally recur in ectopic locations. We present two cases of ectopic recurrence, both in the posterior fossa, and provide a review of the literature with basic statistics. Two patients admitted to our institution with posterior fossa lesions underwent gross total resection. Pathological studies showed adamantinomatous craniopharyngiomas (ACP). Both patients had a prior history of suprasellar tumor surgery. We also reviewed the related data and undertook a basic statistical analysis. We found 67 cases of ectopic recurrent craniopharyngioma (including the present cases): 51 cases were adamantinomatous (76%), 6 papillary (9%) and 10 unknown (15%). 18 cases occurred in the posterior fossa, all of them diagnosed as the ACP subtype. The intervals until recurrence were 15.15 years for posterior fossa recurrences and 5.75 years for supratentorial cases. Student t test showed significant differences in time to recurrence (p 0.002). Gross total resection was performed in 53 cases (79%), subtotal resection + radiotherapy in 3 (5%) and 11 (16%) cases were treated with other options. Ectopic recurrence is a rare but possible event. Those in the posterior fossa may appear later than in the supratentorial space. ACP is likely to be the most common subtype in these cases, possibly due to its more aggressive behavior compared to the papillary subtype. Long term follow-up should be performed to detect ectopic recurrences. Ectopic recurrences are often surgically accessible and gross total resection should be achieved. (AU)


Los craneofaringiomas son tumores epiteliales benignos que pueden recurrir ocasionalmente en localizaciones ectópicas. Presentamos 2 casos de recurrencias ectópicas, ambos en fosa posterior, y realizamos una revisión de la literatura con análisis estadístico básico. Dos pacientes ingresaron en nuestro servicio con lesiones en fosa posterior en quienes se indicó resección quirúrgica. El diagnóstico histopatológico fue de craneofaringioma adamantinomatoso en ambos casos. Ambos pacientes fueron intervenidos años atrás por un tumor supraselar. Se hallaron 67 casos descritos de recurrencia ectópica de craneofaringioma (incluyendo el presente estudio): 51 fueron adamantinomatoso (76%), 6 papilar (9%) y 10 desconocidos (15%). Dieciocho casos ocurrieron en la fosa posterior, todos con diagnóstico de craneofaringioma adamantinomatoso. El intervalo hasta la recurrencia fue de 15,15 años para aquellas en la fosa posterior y de 5,75 años para recurrencias supratentoriales. El test de Student mostró diferencias estadísticamente significativas en el tiempo de recurrencia (p 0,002). En 53 casos se obtuvo una resección completa (79%), resección subtotal + radioterapia en 3 (5%) y 11 casos se usaron otras modalidades de tratamiento (16%). La recurrencia ectópica es un evento raro, pero posible. Aquellas en la fosa posterior pueden aparecer más tarde que a nivel supratentorial. Los craneofaringiomas adamantinomatosos son los subtipos más probables en esos casos, posiblemente debido a su comportamiento más agresivo comparado con los papilares. Un seguimiento a largo plazo debe llevarse a cabo para detectar dichas recurrencias ectópicas, ya que estas suelen ser quirúrgicamente accesibles, y debe obtenerse una resección completa. (AU)


Asunto(s)
Humanos , Masculino , Adulto , Neoplasias Encefálicas/diagnóstico por imagen , Neoplasias Encefálicas/cirugía , Craneofaringioma/diagnóstico por imagen , Craneofaringioma/cirugía , Recurrencia Local de Neoplasia , Fosa Craneal Posterior
20.
Rev. bioét. derecho ; (40): 167-177, jul. 2017. tab
Artículo en Inglés | IBECS (España) | ID: ibc-163464

RESUMEN

Substandard ethical practices in biomedical research have been exported from more developed countries to less developed countries worldwide. The term for this practice is called ethics dumping, which can be described as exporting, in clinical research, sensitive ethical practices from more developed to less developed countries, with subpar requirements and other economic or operational advantages that would be inadmissible in developed countries. Examples for this practice are described, as well as its origin, receptivity, and perpetuation, together with some preliminary guidance and advice in order to work towards possible solutions for this ethically sensitive issue in the future


En la investigación biomédica se han exportado prácticas éticas deficientes desde los países con mayor grado de desarrollo hacia países con menor grado de desarrollo a nivel mundial. El término para esta práctica es el de deposición de prácticas éticas («Ethics Dumping»), que puede describirse como el hecho de exportar, en la realización de investigación clínica, prácticas éticas sensibles del tipo de exigencia disminuida y otras ventajas de índole operativa y económica no aceptables en países desarrollados, hacia países no desarrollados. Se describen ejemplos de esta práctica, así como su origen, receptividad, y perpetuación, junto con algunas guías preliminares y recomendaciones, con el fin de trabajar hacia el futuro en busca de posibles soluciones para este asunto éticamente sensible


Asunto(s)
Humanos , Evaluación de la Tecnología Biomédica/ética , Investigación Biomédica/ética , Ética en Investigación , Academias e Institutos/ética , Investigación sobre Servicios de Salud/ética
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