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1.
Phys Rev Lett ; 132(5): 051002, 2024 Feb 02.
Artículo en Inglés | MEDLINE | ID: mdl-38364164

RESUMEN

We present the measurement of the cosmic ray proton spectrum from 50 TeV to 1.3 PeV using 7.81×10^{6} extensive air shower events recorded by the ground-based GRAPES-3 experiment between 1 January 2014 and 26 October 2015 with a live time of 460 day. Our measurements provide an overlap with direct observations by satellite and balloon-based experiments. The electromagnetic and muon components in the shower were measured by a dense array of plastic scintillator detectors and a tracking muon telescope, respectively. The relative composition of the proton primary from the air shower data containing all primary particles was extracted using the multiplicity distribution of muons which is a sensitive observable for mass composition. The observed proton spectrum suggests a spectral hardening at ∼166 TeV and disfavors a single power law description of the spectrum up to the Knee energy (∼3 PeV).

2.
Opt Express ; 29(22): 36461-36468, 2021 Oct 25.
Artículo en Inglés | MEDLINE | ID: mdl-34809057

RESUMEN

Phase modulators based upon the thermo-optic effect are used widely in silicon photonics for low speed applications such as switching and tuning. The dissipation of the heat produced to drive the device to the surrounding silicon is a concern as it can dictate how compact and tightly packed components can be without concerns over thermal crosstalk. In this paper we study through modelling and experiment, on various silicon on insulator photonic platforms, how close waveguides can be placed together without significant thermal crosstalk from adjacent devices.

3.
Kathmandu Univ Med J (KUMJ) ; 19(73): 118-122, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34812170

RESUMEN

Digital subtraction angiography (DSA) has been a fluoroscopic golden investigative tool to know the vascular angiography of the brain and spinal cord. The technique in performing this procedure exposes residents in accessing the major vessels, branches of the arch of aorta, selective angiography and diagnosing different vascular anomalies of brain and spine. They are also exposed to the knowledge of different diagnostic catheters, its manipulation, use of dye and radiation exposure and safety. We would like to share our experience in training and disseminating the knowledge of digital subtraction angiography to the residents.


Asunto(s)
Angiografía de Substracción Digital , Fluoroscopía , Humanos
4.
Kathmandu Univ Med J (KUMJ) ; 18(70): 149-154, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-33594021

RESUMEN

Background Uncorrected refractive error is the major cause of visual impairment worldwide. There is no data on refractive error prevalence among school children in hilly region of Far West Nepal. Objective The prevalence of refractive error has been found to vary among children of different caste/ethnic groups and geographical regions. The purpose of this study is to determine the prevalence of refractive error among school children from different caste/ethnic groups in Dadeldhura district of Far West Nepal. Method This is a cross sectional study of refractive error among secondary school children from 2 schools in Dadeldhura district. All children underwent a vision screening consisting of visual acuity, ocular examination and refraction. Myopia was diagnosed for an eye with spherical equivalent refraction (SER) ≤ -0.5 D whereas an eye with SER ≥ +2.0 D was diagnosed as hyperopic. Ethnicity was reported through self administered questionnaire. Result Among children aged 12 to 16 years (14.07 ± 1.4) prevalence of myopia was 3.5%, hyperopia 0.33% and astigmatism 1%. All except three children had spherical equivalent refraction (SER) within ±2 D. Caste/ethnicity was not associated significantly with myopia in either eye (χ2 = 0.27, df= 2, p= 0.87). Conclusion The prevalence of refractive error among secondary school children in Dadeldhura district of Far West Nepal is very low in comparison to myopia prevalence reported in studies from other parts of the world, but slightly lower than myopia prevalence found in other, eastern parts of Nepal.


Asunto(s)
Errores de Refracción , Adolescente , Niño , Estudios Transversales , Humanos , Nepal/epidemiología , Prevalencia , Errores de Refracción/epidemiología , Instituciones Académicas
5.
Kathmandu Univ Med J (KUMJ) ; 16(63): 220-224, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-31719310

RESUMEN

Background Parkinsons disease is a central nervous system degenerative disorder affecting motor system and characterized by progressive tremor, rigidity, gait abnormalities. Surgical treatment of Parkinsons disease is based on the changes in the basal gangliothalamocortical circuits which is altered in Parkinsons disease. Currently pallidotomy and Deep Brain Stimulation are available modes of surgical treatment of Parkinsons disease. Objective To know efficacy of deep brain stimulation in Parkinsons Disease in Nepal. Method All patients of idiopathic Parkinsons disease who underwent Deep Brain Stimulation in Annapurna Neurological Institute and Allied sciences since 2014 were included. The standard functional coordinates for Subthalamic nucleus and Globus pallidus internus was used. We used Zamarano-Dujovny (ZD) Fisher Frame with its software. Patients' Unified Parkinsons disease rating score, Modified Hoehn and Yahr Staging and Schwab and England Activities of daily living Scale were evaluated preoperativelyv as well as postoperatively. Result Ten patients underwent Deep Brain Stimulation. The male is to female ratio was 2:1. The mean age was 55.4±8.9 years and duration of illness was 5.5±2 years. There was a significant improvement in the scores for the main motor manifestations of the disease between the preoperative off-dopa and postoperative off-dopa/on-stim conditions. There was a significant improvement in Schwab and England Activities of daily living scale scores in the off-dopa condition between the preoperative score and the postoperative M6 score. Conclusion Our result of Deep Brain Stimulation is quite promising. However, it is very expensive and requires frequent follow-up for neuromodulation.


Asunto(s)
Estimulación Encefálica Profunda/métodos , Enfermedad de Parkinson/terapia , Actividades Cotidianas , Adulto , Femenino , Globo Pálido/fisiología , Humanos , Masculino , Persona de Mediana Edad , Nepal , Núcleo Subtalámico/fisiología , Resultado del Tratamiento
6.
Kathmandu Univ Med J (KUMJ) ; 14(54): 134-139, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-28166069

RESUMEN

Background The worldwide prevalence of diabetic retinopathy (DR) was found to be 34.6%. WHO estimates that DR is responsible for 4.8% of the 37 million cases of blindness throughout the world. In a study undertaken in urban population in Nepal, M.D. Bhattarai found the prevalence of diabetes among people aged 20 years and above to be 14.6% and the prevalence among people aged 40 years and above to be 19%. Studies on DR, to our knowledge, have mostly been hospital based in Nepal. Little information is available about prevalence of DR at the community level in Nepal. Objective To investigate the prevalence of diabetic retinopathy and associated risk factors among known diabetic population of Nepal. Method A descriptive cross sectional study was conducted among individuals aged 30 and more using cluster sampling method. The study sites were Kathmandu metropolitan city and Birgunj sub-metropolitan city. A sample size of 5400 was calculated assuming 5% prevalence rate with 95% confidence level, 5% worst acceptable level and 1.5 cluster sampling design effect. Study participants were interviewed, anthropometric measurements and fundus photograph was taken from participants with diabetes. Fundus photographs were used to grade retinopathy. Result Around 12% of the respondents were diabetic, mean age 55.43±11.86 years, of which slightly more than half were females (50.2%). Among these diabetic respondents 9.9% had some forms of diabetic retinopathy, mean age 54.08±10.34 years, 56.7% were male. When severe grade of retinopathy in any eye was considered as overall grade of retinopathy for the individual, prevalence of Non-proliferative Diabetic Retinopathy, Proliferative Diabetic Retinopathy and complete vision loss was found to be 9.1%, 0.5% and 0.3%. Prevalence of Diabetic Macular Edema was 5.5%. Duration of diabetes, family history of diabetes and blood pressure at the day of survey was found to be associated with having any retinopathy. Conclusion Diabetic retinopathy is emerging as a public health threat in Nepal. With increasing diabetes, DR can be expected to increase more. Existing eye care services may require upgrading to provide quality and affordable retinopathy services to address this emerging problem.


Asunto(s)
Retinopatía Diabética/epidemiología , Tamizaje Masivo/estadística & datos numéricos , Enfermedades de la Retina/epidemiología , Adulto , Anciano , Ceguera/epidemiología , Presión Sanguínea , Estudios Transversales , Femenino , Humanos , Masculino , Persona de Mediana Edad , Nepal/epidemiología , Prevalencia , Factores de Riesgo
7.
J Nepal Health Res Counc ; 12(28): 208-10, 2014.
Artículo en Inglés | MEDLINE | ID: mdl-26032063

RESUMEN

Haphazard use of pesticides in the field and stored food commodities for the control of insect and pest has been a serious problem from view of environment and public health. The nutritional value of these is suppressed due to addition of toxins. The increased trend of Non communicable disease and communicable diseases may have close relation with the nutritious value and life styles associated with. The impacts on health should be considered as important issues from the view of public health. The article gives emphasis on organic farming & Integrated Pest Management (IPM) to minimize the harm of chemicals. It is deemed essential to think again about the current trend of malnutrition & obesity overweight among the Nepalese people and relationship with pesticides on the foods and vegetables.


Asunto(s)
Contaminación de Alimentos , Plaguicidas/efectos adversos , Verduras/química , Agricultura , Contaminación Ambiental/efectos adversos , Contaminación Ambiental/prevención & control , Humanos , Nepal , Plaguicidas/análisis , Salud Pública , Verduras/efectos adversos
8.
Nepal J Ophthalmol ; 4(1): 102-7, 2012.
Artículo en Inglés | MEDLINE | ID: mdl-22344006

RESUMEN

INTRODUCTION: Sub-hyaloid haemorrhage is common in acute leukemia. OBJECTIVE: To investigate the effects of Nd: YAG Laser hyaloidotomy in 11 eyes of 8 patients with pre-macular haemorrhage in acute childhood leukemia. MATERIALS AND METHODS: Premacular sub-hyaloid haemorrhage is one of the leading causes of visual disability in children with acute leukemia. Eleven eyes of 8 patients attending Kanti Children Hospital and BP Koirala Lions Centre for Ophthalmic Studies from January 2006 to July 2007 with premacular subhyaloid haemorrhage were included in the study and treated with Nd: YAG Laser. The haemorrhage originated from acute myeloid leukemia (AML) in 4 cases (6 eyes) and acute lymphoblastic leukemia (ALL) in 4 cases (5 eyes). RESULTS: Drainage of premacular sub-hyaloid haemorrhage into the vitreous cavity within 3 months succeeded in 9 eyes out of 11 eyes treated. One eye had a dense clotted haemorrhage and the other had a re-bleed. Overall visual improvement was equal in both AML and ALL cases. No obvious epiretinal membrane, retinal breaks and tractional retinal detachment occurred in any eye. CONCLUSION: Nd: Yag laser hyaloidotomy is a relatively safe, simple and alternative treatment for eyes with a dense premacular sub-hyaloid haemorrhage in acute childhood leukemia. The risks and benefits have to be weighed in randomized clinical trials to establish Nd: YAG hyaloidotomy treatment as a routine procedure in leukemic children.


Asunto(s)
Terapia por Láser/métodos , Láseres de Estado Sólido/uso terapéutico , Leucemia/complicaciones , Hemorragia Retiniana/cirugía , Adolescente , Niño , Femenino , Estudios de Seguimiento , Humanos , Masculino , Retina/patología , Retina/cirugía , Hemorragia Retiniana/etiología , Hemorragia Retiniana/patología , Estudios Retrospectivos , Resultado del Tratamiento , Agudeza Visual
9.
JNMA J Nepal Med Assoc ; 52(185): 1-5, 2012.
Artículo en Inglés | MEDLINE | ID: mdl-23279765

RESUMEN

INTRODUCTION: Chronic subdural hematoma (CSDH) may occasionally contain organized hematoma which can lead to recurrence and other complications after surgery. There is no exact study and data about OHTMF in Nepal so far. The main objective of this study is to study its prevalence and complications. METHODS: This is a multicentric retrospective analytical study being carried out at Norvic International Hospital and Annapurna Neurological Institute. We retrospectively analyzed one hundred cases of CSDH between early 2006 to 2010 August. We focused our study mainly on OHTMF. RESULTS: Of 100 cases, majority of the patients were male ranging from 4 to 85 years of age. Bilateral subdural hematoma was found in about 9% of cases. Majority of cases were treated in usual fashion with single burr hole and drain. OHTMF was found in 3 cases (3%) for which craniotomy with radical membranectomy was performed. In 2 cases membrane formation was noticed during surgery, craniotomy with total membranectomy was performed immediately. In one case there was recurrence of CSDH within 10 days of single burr hole evacuation. Craniotomy with membranectomy was performed in 2nd surgery. There was no recurrence after membranectomy. One case developed seizure post operatively. CONCLUSIONS: OHTMF is one of the important causes of CSDH recurrence. It has to be treated radically. Different hypthotheses have been postulated regarding thick membrane formation in CSDH. We have tried to discuss these hypotheses.


Asunto(s)
Hematoma Subdural Crónico/patología , Hematoma Subdural Crónico/cirugía , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Niño , Preescolar , Craneotomía , Drenaje , Femenino , Hematoma Subdural Crónico/diagnóstico por imagen , Humanos , Masculino , Persona de Mediana Edad , Nepal , Recurrencia , Estudios Retrospectivos , Tomografía Computarizada por Rayos X , Adulto Joven
10.
JNMA J Nepal Med Assoc ; 51(184): 192-5, 2011.
Artículo en Inglés | MEDLINE | ID: mdl-22922900

RESUMEN

Neurocysticercosis (NCC), caused by the pork tapeworm Taenia solium, is reported to be a common condition in Nepal. So far imaging diagnosis was mainstay of the diagnosis. In this paper, we report three patients presenting with neurological symptoms due to intraventricular NCC. We have diagnosed the causative agent as T. solium on molecular basis. Further research is warranted to assess the actual health impact of T. solium in Nepal.


Asunto(s)
Ventrículos Cerebrales/parasitología , Neurocisticercosis/diagnóstico , Taenia solium/aislamiento & purificación , Adolescente , Anciano , Animales , Anticuerpos Antihelmínticos/análisis , Ventriculografía Cerebral/métodos , Diagnóstico Diferencial , Femenino , Humanos , Masculino , Persona de Mediana Edad , Taenia solium/inmunología , Tomografía Computarizada por Rayos X
11.
Nepal Med Coll J ; 12(2): 95-9, 2010 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-21222406

RESUMEN

A retrospective hospital based study was designed in order to evaluate the refractive status of students presenting to Geta Eye Hospital. All the hospital record of secondary level school students were collected from the record unit of the hospital. Children below 5 years of age and those with incomplete record were excluded from the study. All students who visited Geta Eye hospital during May 1 to July 30, 2007 AD were included in the study. Out of 328 students presenting to Geta Eye Hospital, presenting visual acuity was normal (6/6) in 67.4% students, while 32.6% had reduced presenting visual acuity. Altogether 7.0% students had presenting visual acuity worse than 6/18 in the better eye and 2.4% improved to better than 6/18 with correction. Significant refractive error (>0.50 D Spherical Equivalent) was found in total of 32.0% students. Myopia was present in 11.89% students, whereas Astigmatism and hypermetropia were present in 11.3% and 8.8% of the total students respectively. Out of total students, 95.4% students were found to have best corrected visual acuity of 6/6-6/18 in the better eye. There were 4.0% students in MVI category and 0.6% in SVI category after correction. Altogether 7.6% cases of amblyopia were found. Hyperopia was most commonly associated with amblyopia. Associated ocular morbidity in either eye was assessed and was found in 25.0% students. 6.4% cases had convergence insufficiency. About one third of the students presenting to hospital had significant refractive error. Thus, School can be our peripheral referral unit if we could train teachers to detect abnormal vision.


Asunto(s)
Ambliopía/epidemiología , Errores de Refracción/epidemiología , Estudiantes/estadística & datos numéricos , Agudeza Visual , Adolescente , Niño , Femenino , Hospitales Especializados , Humanos , Nepal/epidemiología , Estudios Retrospectivos
12.
Kathmandu Univ Med J (KUMJ) ; 8(32): 370-4, 2010.
Artículo en Inglés | MEDLINE | ID: mdl-22610764

RESUMEN

BACKGROUND: At present there is no data available on reduced vision and refractive errors in school children of far western Nepal. So, school screening records were used to obtain data useful for planning of refractive services. METHODS: Data are provided from school screening conducted by Geta Eye Hospital during February/March 2008. The cases with complete data sets on visual acuity, refractive error and age were included and analyzed using computer software. RESULTS: Of 1165 children (mean age 11.6 ± 2.5 years) examined, 98.8% (n = 1151) had uncorrected visual acuity of 6/9 and better in at least one eye whereas 1.2% (n = 14) had acuity 6/12 and worse in both eyes. Among them, either eye of 9 children improved to 6/9 and better with correction. However, visual acuity was 6/12 and worse in both eyes of 5 children even after correction. There were 24 children with refractive errors (myopia, 1.54%; n = 18 and hypermetropia, 0.51%; n = 6) in at least one eye. The spherical equivalent refraction was not significantly different with age and gender. CONCLUSIONS: The incidence of reduced vision and refractive errors among school children of this semi rural district were low.


Asunto(s)
Errores de Refracción/epidemiología , Población Rural , Instituciones Académicas , Selección Visual/métodos , Baja Visión/epidemiología , Distribución por Edad , Niño , Procesamiento Automatizado de Datos , Femenino , Humanos , Incidencia , Masculino , Nepal/epidemiología , Errores de Refracción/diagnóstico , Estudios Retrospectivos , Distribución por Sexo , Baja Visión/diagnóstico , Agudeza Visual
13.
Indian J Public Health ; 53(4): 259-63, 2009.
Artículo en Inglés | MEDLINE | ID: mdl-20469771

RESUMEN

Demographic imbalance created because of the declining sex ratio in India is a cause of concern to policy makers, implementers, demographers and social reformers. To take situation under control, Pre Natal Diagnostic Techniques (PNDT) Act is operational since 1996. Authors have critically reviewed the status of women and socio-cultural factors influencing their status based on data from NFHS III and census 2001 and challenges faced in the operationalisation of PNDT Act in India.


Asunto(s)
Bienestar Materno/legislación & jurisprudencia , Razón de Masculinidad , Valores Sociales , Derechos de la Mujer , Femenino , Humanos , India , Masculino , Dinámica Poblacional , Embarazo , Preselección del Sexo
14.
Indian J Public Health ; 51(4): 244-5, 2007.
Artículo en Inglés | MEDLINE | ID: mdl-18232168

RESUMEN

This health center based study was conducted to find out the proportion and distribution of clinico-social factors for sexually transmitted diseases among male OPD attanders of urban health centre, Subharti Medical College, Meerut. Out of the total 150 male cases of genital diseases from January to June 2005, 42 were found to be symptomatic for STDs according to syndromic approach. The most common symptom was urethral discharge (35.7%). Illiteracy, trucker's occupation, multiple sex partners, extra marital relationship and non-usage of condom were found to be important socio-clinical factors for STDs.


Asunto(s)
Conducta Sexual/estadística & datos numéricos , Enfermedades de Transmisión Sexual/epidemiología , Población Urbana/estadística & datos numéricos , Escolaridad , Humanos , India/epidemiología , Masculino , Ocupaciones , Servicio Ambulatorio en Hospital/estadística & datos numéricos , Enfermedades de Transmisión Sexual/complicaciones , Clase Social
15.
Indian J Public Health ; 50(1): 60-1, 2006.
Artículo en Inglés | MEDLINE | ID: mdl-17193768

RESUMEN

The prevalence of RTIs in 600 married females (15-44 yrs.) representing 12 subcentre villages of Daurala block of Meerut was 35.3%. The reproductive tract infections were significantly associated with place of last delivery (P< 0.001), person conducted the last delivery (P< 0.001) and in women had history of abortions (P< .005).


Asunto(s)
Enfermedades de los Genitales Femeninos/epidemiología , Aborto Inducido/estadística & datos numéricos , Adolescente , Adulto , Femenino , Parto Domiciliario , Humanos , India/epidemiología , Persona de Mediana Edad , Paridad , Periodo Posparto , Embarazo , Prevalencia , Salud Rural
16.
Artículo en Inglés | MEDLINE | ID: mdl-12635830

RESUMEN

The therapeutic efficacy of monoisoamyl meso-2,3-dimercaptosuccinic acid (MiADMSA), a new monoester of 2,3-dimercaptosuccinic acid on arsenic induced oxidative stress in liver and kidneys, alterations in hematopoietic system and depletion of arsenic burden was assessed, in mice. Three different doses of MiADMSA (25, 50 or 100 mg/kg) for five consecutive days were administered in chronically arsenic exposed mice (10 ppm in drinking water for six months). Oral administration of MiADMSA particularly at a dose of 50 mg/kg, produced relatively more pronounced beneficial effects on the inhibited blood delta-aminolevulinic acid dehydratase (ALAD), biochemical variables indicative of hepatic and renal oxidative stress and depletion of arsenic concentration in blood, liver and kidneys, compared with intraperitoneal administration of the drug. The treatment with MiADMSA although, produced essential metals imbalance which could be a restrictive factor for the possible therapeutic use of this compound in chronic arsenic poisoning and thus require further exploration.


Asunto(s)
Intoxicación por Arsénico/terapia , Estrés Oxidativo , Succímero/análogos & derivados , Succímero/farmacología , Administración Oral , Animales , Modelos Animales de Enfermedad , Infusiones Parenterales , Riñón/patología , Hígado/patología , Masculino , Ratones , Succímero/administración & dosificación
17.
J Appl Toxicol ; 22(6): 359-69, 2002.
Artículo en Inglés | MEDLINE | ID: mdl-12424740

RESUMEN

Monoisoamyl 2,3-dimercaptosuccinic acid (MiADMSA), a vicinal thiol chelator, is gaining recognition recently as a better chelator than meso 2,3-dimercaptosuccinic acid (DMSA) in decreasing heavy metal burden in tissues because of its lipophilic character. There is, however, little information available on the toxicological properties of this chelator after repeated administration in animals. In the present study, we investigated the dose-dependent effect of MiADMSA on various biochemical parameters suggestive of alterations in haem biosynthesis and hepatic, renal and brain oxidative stress after 21 days of repeated intraperitoneal (i.p.) or oral (p.o.) administration to rats. The concentration of essential metals in blood and soft tissues was determined along with histopathological observations of hepatic and renal tissues. The results suggest that MiADMSA administration had no effect on blood delta-aminolevulinic acid dehydratase activity. However, an increase in zinc protoporphyrin and a decrease in haemoglobin levels were noted in animals given MiADMSA i.p. A moderate increase in serum alkaline phosphatase suggested mild hepatotoxicity at the highest dose (100 mg kg(-1), i.p.). This was confirmed by histopathological examinations, which identified basophilic stippling, granulation of the cytoplasm, haemorrhage and congestion. At the highest dose, levels of hepatic thiobarbituric acid reactive substance and oxidized glutathione were increased above those of control values. Levels of hepatic reduced glutathione were decreased. Taken together, these observations point to oxidative stress. In animals administered MiADMSA i.p. there was an increase in the brain malondialdehyde levels at the two higher doses (50 and 100 mg kg(-1)). Essential metal status revealed a significant effect of MiADMSA (p.o.) in increasing blood zinc while significantly decreasing the kidney zinc level. The most significant adverse effect of MiADMSA was on copper concentration, which showed significant depletion from almost all major organs. Magnesium levels in blood decreased but increased in liver of MiADMSA-administered rats. Histopathological observations of liver and kidneys suggest few moderate lesions. It can be concluded that repeated administration of MiADMSA is compromised with some mild toxic effect, particularly the loss of copper. The effects during oral administration are comparatively less pronounced than by the i.p. route.


Asunto(s)
Quelantes/toxicidad , Succímero/análogos & derivados , Succímero/toxicidad , Administración Oral , Animales , Encéfalo/efectos de los fármacos , Encéfalo/metabolismo , Quelantes/administración & dosificación , Cobre/sangre , Relación Dosis-Respuesta a Droga , Hemo/biosíntesis , Inyecciones Intraperitoneales , Hierro/sangre , Riñón/efectos de los fármacos , Riñón/metabolismo , Riñón/patología , Hígado/efectos de los fármacos , Hígado/metabolismo , Hígado/patología , Masculino , Estrés Oxidativo , Ratas , Ratas Wistar , Succímero/administración & dosificación , Distribución Tisular , Zinc/sangre
18.
Toxicol Lett ; 132(1): 9-17, 2002 Jun 07.
Artículo en Inglés | MEDLINE | ID: mdl-12084615

RESUMEN

The effect of meso 2,3-dimercaptosuccinic acid (DMSA) and monoisoamyl DMSA (MiADMSA) on gallium arsenide (GaAs) induced liver damage was studied. The oral feeding rat model was used in this study. The animals were exposed to 10 mg/kg GaAs, orally, once daily, 5 days a week for 24 weeks and treated thereafter with single oral daily dose of either 0.3 mmol/kg DMSA or MiADMSA for two course of 5 days treatment. The animals were sacrificed thereafter. Lipid peroxidation was assessed by measuring liver thiobarbituric acid reactive substance (TBARS). Liver damage was assessed by number of biochemical variables and by light microscopy. The activity of superoxide dismutase (SOD) and delta-aminolevulinic acid dehydratase (ALAD) beside reduced glutathione (GSH) concentration was measured in blood. Exposure to GaAs produced a significant reduction in GSH while, increased the oxidized glutathione (GSSG) concentration. Hepatic glutathione peroxidase (GPx) and catalase activity increased significantly while level of serum transaminase increased moderately. Gallium arsenide exposure also produced marked hepatic histopathological lesions. Overall, treatment with MiADMSA proved to be better than DMSA in the mobilization of arsenic and in the turnover of some of the above mentioned GaAs sensitive biochemical alterations. Histopathological lesions also, responded more favorably to chelation treatment with MiADMSA than DMSA.


Asunto(s)
Arsenicales/antagonistas & inhibidores , Quelantes/farmacología , Enfermedad Hepática Inducida por Sustancias y Drogas/prevención & control , Galio/antagonistas & inhibidores , Galio/toxicidad , Succímero/análogos & derivados , Succímero/farmacología , Alanina Transaminasa/sangre , Animales , Aspartato Aminotransferasas/sangre , Catalasa/metabolismo , Enfermedad Hepática Inducida por Sustancias y Drogas/enzimología , Enfermedad Hepática Inducida por Sustancias y Drogas/patología , Glutatión/sangre , Glutatión Peroxidasa/metabolismo , Peroxidación de Lípido/efectos de los fármacos , Pruebas de Función Hepática , Masculino , Metales/metabolismo , Oxidación-Reducción , Estrés Oxidativo/efectos de los fármacos , Porfobilinógeno Sintasa/sangre , Ratas , Superóxido Dismutasa/metabolismo
19.
Med Hypotheses ; 57(2): 210-5, 2001 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-11461175

RESUMEN

Tardive dyskinesia (TD) is a severe and troubling complication of long-term typical neuroleptic use whose etiology remains obscure. While it is widely believed that central nervous system (CNS) dopamine receptor super-sensitivity is involved in the pathogenesis of the condition, it is unclear why some patients develop TD while others do not. It is proposed that a subclinical peripheral motoneuropathy with consequent enlarging of the motor units may act to unmask neuroleptic-induced CNS changes allowing for the expression of TD. To investigate this hypothesis we examined motor unit size with electrographic examinations in 14 patients (six with mild TD; eight without and all with psychotic illness). There were no differences between the two groups of patients. While the data do not appear to support the hypothesis, a larger study with more severely affected patients is required to more adequately test the hypothesis.


Asunto(s)
Sistema Nervioso Central/fisiopatología , Discinesia Inducida por Medicamentos/etiología , Enfermedades del Sistema Nervioso Periférico/complicaciones , Adulto , Electromiografía , Femenino , Humanos , Masculino , Persona de Mediana Edad , Sistema Nervioso Periférico/fisiopatología
20.
Environ Toxicol Pharmacol ; 9(4): 173-184, 2001 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-11292581

RESUMEN

The administration of chelating agents, meso 2,3-dimercaptosuccinic acid (DMSA), monoisoamyl DMSA (MiADMSA) either individually or in combination with an antioxidant, n-acetylcysteine (NAC) in the prevention and treatment of acute lead intoxication in rats, was investigated. The results suggest that concomitant oral supplementation of DMSA with lead was most effective in preventing the inhibition of lead sensitive blood delta-aminolevulinic acid dehydratase (ALAD) activity in blood, elevation of zinc protoporphyrin level and the alterations in hepatic reduced and oxidized glutathione (GSH and GSSG) contents. A number of other biochemical variables either remained insensitive to lead exposure or responded moderately to chelation treatment. Combined administrations of NAC plus DMSA was most effective when given during lead exposure or post exposure, followed by DMSA and MiADMSA alone or NAC plus MiADMSA treatment, in reducing the accumulation of lead in blood and liver. Administration of NAC alone was only mildly effective in preventing lead absorption in the blood and tissues. The results suggest that combined administration of DMSA and NAC could be a more effective treatment protocol for acute lead toxicity, keeping in view its beneficial effect on oxidative injury.

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