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Pythium spp. cause seed decay, damping-off, and root rot in soybean and corn; however, their diversity and importance as pathogens in Minnesota are unknown. Our objectives were to identify the Pythium spp. present in Minnesota soybean fields, determine their aggressiveness on corn and soybean, and investigate their sensitivity to seed treatment fungicides. For identification, sequences obtained using internal transcribed space ITS4 and ITS1 primers were compared with reference sequences in the National Center for Biotechnology Information database. Seedling and soil samples yielded over 30 oomycete species. Aggressiveness was determined using two methods; a seed assay, which also examined temperature effects on aggressiveness, and a seedling assay. Of 21 species evaluated, seven Pythium spp. were pathogenic on both soybean and corn, reducing root growth by 20% or more while two Pythium and one Phytopythium spp. were pathogenic only on soybean. Aggressiveness of many isolates increased as temperature increased from 15°C to 25°C. The sensitivity of 10 pathogenic species to azoxystrobin, ethaboxam, mefenoxam, pyraclostrobin, or trifloxystrobin was tested. EC50 values for mefenoxam and ethaboxam were 10-2 of those to strobilurin fungicides. Pythium spp. in Minnesota are diverse and a significant cause of seedling disease on soybean and corn. Most Pythium spp. isolated in this study were more sensitive to mefenoxam and ethaboxam than to strobilurin fungicides.
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Blueberries are eaten fresh or after storing at room temperature, refrigerator or freezer but little is known about changes in food values of wild blueberries due to harvest dates and storage conditions. The aim of this study was to investigate the effect of harvest date and storage conditions of wild blueberries on berry quality and health related chemistry. We analyzed Vaccinium angustifolium, V. angustifolium var. nigrum, and V. myrtilloides native to NW Ontario, Canada harvested early and late in the season for total phenol (TP), anthocyanin contents (AC), and soluble solids to titratable acidity ratio storing at room temperature, refrigerator and freezer temperature. We also determined their antioxidant content and activity (ORAC). Late harvest and low temperature storage significantly increased TP and AC for most genotypes. In V. myrtilloides TP increased by 50, 44 and 45% respectively at late harvest, 14 days refrigerator and 90 days freezer storage. It also had significantly higher ORAC (22 and 33%) than the other two genotypes. Wild blueberry pickers and consumers can optimize health benefits and quality attributes of blueberries by customizing harvest protocols and choice of cultivar and storage in household fridge and freezer. Blueberry storage, at household fridge and freezer temperature, does not reduce its health benefits.
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White spot disease (WSD) caused by white spot syndrome virus (WSSV) creates severe epizootics in shrimp aquaculture industry worldwide. Despite several efforts, no such permanent remedy was yet developed. Selective breeding using DNA markers would be a cost-effective strategy for long-term solution of this problem. In the present investigation, out of 30 random primers, only one primer produced a statistically significant (P < 0.01) randomly amplified polymorphic DNA (RAPD) marker of 502 bp, which provided a good discrimination between disease resistant and disease susceptible populations of Penaeus monodon from three geographical locations along the East coast of India. Because RAPD markers are dominant, a sequence characterized amplified region (SCAR) marker was developed by cloning and sequencing of 502 bp RAPD fragment, which generates a single 457 bp DNA fragment after PCR amplification only in the disease resistant shrimps. Challenge experiment was also conducted to validate this 457 bp SCAR marker, and the results suggested that the WSSV loads were 2.25 × 10(3) fold higher in disease susceptible than that in disease resistant shrimps using real-time PCR. Therefore, this 457 bp DNA SCAR marker will be very valuable towards the development of disease-free shrimp aquaculture industry.
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Resistencia a la Enfermedad/genética , Penaeidae/genética , Penaeidae/virología , Virus del Síndrome de la Mancha Blanca 1/fisiología , Animales , Marcadores Genéticos , Técnica del ADN Polimorfo Amplificado Aleatorio/veterinaria , Reacción en Cadena en Tiempo Real de la Polimerasa/veterinariaRESUMEN
Audiovestibular sequelae of electrical injury, due to lightning or electric current, are probably much more common than indicated in literature. The aim of the study was to review the impact of electrical injury on the cochleovestibular system. Studies were identified through Medline, Embase, CINAHL and eMedicine databases. Medical Subject Headings used were 'electrical injury', 'lightning', 'deafness' and 'vertigo'. All prospective and retrospective studies, case series and case reports of patients with cochlear or vestibular damage due to lightning or electrical current injury were included. Studies limited to external and middle ear injuries were excluded. Thirty-five articles met the inclusion criteria. Fifteen reported audiovestibular damage following electric current injury (domestic or industrial); a further 15 reported lightning injuries and five concerned pathophysiology and management. There were no histological studies of electrical current injury to the human audiovestibular system. The commonest acoustic insult after lightning injury is conductive hearing loss secondary to tympanic membrane rupture and the most frequent vestibular symptom is transient vertigo. Electrical current injuries predominantly cause pure sensorineural hearing loss and may significantly increase a patient's lifetime risk of vertigo. Theories for cochleovestibular damage in electrical injury include disruption of inner ear anatomy, electrical conductance, hypoxia, vascular effects and stress response hypothesis. The pathophysiology of cochleovestibular damage following electrical injury is unresolved. The mechanism of injury following lightning strike is likely to be quite different from that following domestic or industrial electrical injury. The formulation of an audiovestibular management protocol for patients who have suffered electrical injuries and systematic reporting of all such events is recommended.
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Oído Interno/lesiones , Traumatismos por Electricidad/diagnóstico , Traumatismos por Acción del Rayo/diagnóstico , Accidentes de Trabajo , Sordera/diagnóstico , Sordera/terapia , Traumatismos por Electricidad/terapia , Pérdida Auditiva Sensorineural/diagnóstico , Pérdida Auditiva Sensorineural/terapia , Humanos , Traumatismos por Acción del Rayo/terapia , Enfermedad de Meniere/diagnóstico , Enfermedad de Meniere/terapia , Pronóstico , Reino UnidoRESUMEN
BACKGROUND: Visceral leishmaniasis is potentially fatal protozoan diseases caused by Leishmania donovani. Nepal is an endemic region in which visceral leishmaniasis causes a major public health problem in the lowland areas that border the endemic areas of Bihar state in India. Accurate diagnosis to inform treatment is a first step in achieving the goal of visceral leishmaniasis elimination from South East Asian regions by 2020. OBJECTIVE: The objective of the present study was to compare between the Microcopy and polymerase chain reaction for diagnosis of visceral leishmaniasis. METHODS: In the present study, 236 bone marrow aspirations were collected from suspected visceral leishmaniasis patients in Janakpur Zonal Hospital, Dhanusa district, Terai region of Nepal in between 2003-2007. We evaluated bone marrow samples by microscopic examination with subsequent testing of the same sample by polymerase chain reaction and sequence analysis. RESULTS: Giemsa's solution stained bone marrow slides stored for over five years were used for polymerase chain reaction amplification. The result showed that 71% were polymerase chain reaction positive and 56% were microscopic positive. Out of 104 microscopic negative bone marrow samples, 15% of samples were positive by polymerase chain reaction. CONCLUSION: Polymerase chain reaction could make a very good option for diagnosis by using less or non-invasive material from visceral leishmaniasis patients in endemic areas of Nepal.
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Médula Ósea/patología , ADN Protozoario/análisis , Leishmania donovani/genética , Leishmaniasis Visceral/diagnóstico , Reacción en Cadena de la Polimerasa/métodos , Adolescente , Adulto , Animales , Biopsia con Aguja , Médula Ósea/parasitología , Diagnóstico Diferencial , Femenino , Humanos , Leishmaniasis Visceral/genética , Leishmaniasis Visceral/parasitología , Masculino , Persona de Mediana Edad , Reproducibilidad de los Resultados , Estudios Retrospectivos , Adulto JovenRESUMEN
We consider the Sel'kov model of glycolytic oscillator for a quantitative study of the limit cycle oscillations in the system. We identify a region of parameter space where perturbation theory holds and use both Linstedt Poincaré technique and harmonic balance to obtain the shape and frequency of the limit cycle. The agreement with the numerically obtained result is excellent. We also find a different extreme, where the limit cycle is of the relaxation oscillator variety, has a large time period and it is seen that, as a particular parameter in the model is varied, the time period increases indefinitely. We characterize this divergence numerically. A calculational method is devised to capture the divergence approximately.
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Glucólisis , Modelos Biológicos , TemperaturaRESUMEN
Community awareness, preparedness and response to public health emergencies are essential for a successful response to public health emergencies. This study was carried out to determine community awareness and perceptions regarding health sector preparedness and response to Cyclone Nargis in Myanmar. Six focus group discussions were carried out in 3 villages severely affected by Cyclone Nargis. Thematic content analysis was carried out to determine community perceptions. Focus group participants, consisting of community members, community leaders and government personnel, were aware of the cyclone, but were unaware of its intensity and where it would make landfall. There was inadequate knowledge on how to prepare for a cyclone. There was some training on cyclone preparation but coverage was not wide enough. Participants received service and relief from health sector; they had a positive attitude toward health services provided to them. However, 5 out of 6 focus groups stated most villagers were not interested in health education. Only a few participants had some knowledge on how to prepare for a cyclone. Based on these results, there are evident weaknesses on how to prepare for cyclones. Community preparedness is essential to prevent disasters with cyclones, such as with Cyclone Nargis.
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Concienciación , Tormentas Ciclónicas , Planificación en Desastres/organización & administración , Adolescente , Adulto , Estudios Transversales , Atención a la Salud/organización & administración , Femenino , Grupos Focales , Humanos , Conocimiento , Masculino , Persona de Mediana Edad , Mianmar , Adulto JovenAsunto(s)
Infecciones por Virus ADN/veterinaria , Repeticiones de Microsatélite/genética , Penaeidae/virología , Virus del Síndrome de la Mancha Blanca 1/patogenicidad , Animales , Infecciones por Virus ADN/genética , Susceptibilidad a Enfermedades/veterinaria , Marcadores Genéticos/genética , Penaeidae/genéticaAsunto(s)
Insuficiencia de la Válvula Mitral/cirugía , Enfermedad de von Willebrand Tipo 2/cirugía , Factor VIII/uso terapéutico , Humanos , Masculino , Persona de Mediana Edad , Periodo Perioperatorio , Cuidados Posoperatorios , Resultado del Tratamiento , Enfermedad de von Willebrand Tipo 2/tratamiento farmacológico , Factor de von Willebrand/metabolismoRESUMEN
White spot disease caused by white spot syndrome virus (WSSV) is responsible for harming shrimp aquaculture industry and results in a pandemic throughout the world. Undeniably, the knowledge on geographic distribution, transmission, virulence, and seasonal prevalence of this disease alongside information on the distribution of disease-resistant shrimps may be helpful to understand important aspects of disease biology. This study was intended to estimate WSSV prevalence by qualitative and quantitative PCR method among the Penaeus monodon samples collected from four different places namely Digha, West Bengal; Chilika, Orissa; Visakhapatnam, Andhra Pradesh; and Chennai, Tamil Nadu at three different seasons in the period of 2011-2013 from east coast of India. Along with this, the disease-resistant prevalence was also investigated using earlier developed 71 bp microsatellite and 457 bp RAPD-SCAR DNA marker among the collected shrimps. Qualitative PCR depicted that the cumulative WSSV prevalence at four places was the lowest (0%) at pre-monsoon, whereas, it was the highest (21.2%) during post-monsoon season. Quantitative real-time PCR showed the average copy number of WSSV to be the highest (~10(3) copy µg(-1) shrimp genomic DNA) at post-monsoon season. Additionally, estimated disease-resistant prevalence was the highest in Visakhapatnam (79%) and lowest in Digha (21%). It is well known to all that a trait cannot be identified using a single genetic pattern. This study will significantly contribute insight to develop specific pathogen-resistant (SPR) seeds of P. monodon simultaneously using two DNA markers that would be a cost-effective and safer approach towards disease prevention instead of conventional trends of seed generation from unselected wild broodstock.
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Resistencia a la Enfermedad/genética , Penaeidae/virología , Virus del Síndrome de la Mancha Blanca 1/genética , Animales , ADN Viral/análisis , Marcadores Genéticos , India , Datos de Secuencia Molecular , Prevalencia , Técnica del ADN Polimorfo Amplificado Aleatorio , Reacción en Cadena en Tiempo Real de la Polimerasa , Estaciones del AñoRESUMEN
OBJECTIVE: A non-invasive imaging technique (laser Doppler perfusion imaging-LDI) based on measurement of backscattered Doppler-broadened near infra-red laser radiation was used to provide two-dimensional images of perfusion over the proximal interphalangeal (PIP) joints of a group of normal subjects compared to a group of patients with rheumatoid arthritis (RA). RESULTS: Some PIP joints of the RA group showed areas of increased perfusion whereas normal subjects showed much less variation in perfusion between joints. These hyperaemic areas arose from the underlying joint, as scans taken with a less penetrating red laser did not show such areas. CONCLUSION: Apart from its obvious dermatological uses, LDI could be employed to image hyperaemia associated with a variety of inflammatory conditions affecting subcutaneous structures.
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Artritis Reumatoide/fisiopatología , Articulaciones de los Dedos/irrigación sanguínea , Flujometría por Láser-Doppler/métodos , Adulto , Velocidad del Flujo Sanguíneo , Femenino , Humanos , Procesamiento de Imagen Asistido por Computador , Masculino , Persona de Mediana EdadRESUMEN
This paper analyses the results of post-operative radiotherapy in 256 cases of cancer of the corpus uteri. Myometrial invasion by tumour was shown to be significantly related to histological grading (p less than 0.001) as it was to recurrence rates (p less than 0.025). By placing patients into one of three subsets according to the depth of myometrial invasion, survival was sufficiently different for each subset to validate their use, not only for prognostic purposes but to determine the type of radiotherapy indicated. Radiotherapy was given as either local intravaginal treatment using an obturator loaded with 60Co or by a combination of this and external beam teletherapy. The value of using radiotherapy to treat the whole pelvis as opposed to treating only the vaginal tissues was significant (p less than 0.01) in terms of local disease control for the deep myometrial invasive group. In terms of survival, external beam therapy was of benefit for all three subsets, i.e. superficial, not more than half and more than half myometrial invasion. A planned approach to post-operative radiotherapy was significantly better for the series as a whole compared to previous ad hoc approaches (p less than 0.01). The treatment methods used did not produce unacceptable morbidity.
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Neoplasias Uterinas/radioterapia , Adulto , Anciano , Femenino , Humanos , Ganglios Linfáticos , Persona de Mediana Edad , Miometrio , Metástasis de la Neoplasia , Recurrencia Local de Neoplasia , Neoplasias Uterinas/mortalidad , Neoplasias Uterinas/cirugía , Neoplasias Vaginales/radioterapiaRESUMEN
BACKGROUND: Iodine deficiency disorders (IDDs) are an important cause of mental handicap and poor educability of children. Though Delhi does not lie in the classical Himalayan goitre belt, it has been shown that IDD was endemic in Delhi. Studies of school children in Delhi reported a total goitre rate of 55% which indicates severe endemicity. The sale of uniodized salt has been banned in Delhi since July 1989. This study was done five years later to assess the impact of this measure on IDD prevalence in Delhi. METHODS: A cross-sectional study was done among class VI students studying in government schools of Delhi. A complete list of government middle schools in Delhi was obtained and 30 were selected on the basis of 'probability proportion to size'. A sample size of 1200 was decided based on an expected prevalence of 50% with 5% error and design effect of three. All children in class VI of each school were clinically examined by a trained doctor for the presence of goitre and casual urine samples were collected in capped plastic tubes. The urinary iodine estimation was done by the wet ashing method. RESULTS: The total goitre rate was 20.5%. If the results were limited to children in the age group of 10-12 years it was 19.7%. The urinary iodine was less than the recommended 100 micrograms/L of urine in 23.6% of the children; 7.6% had no iodine in the urine. It is possible that some children could have substituted water in place of urine. The median urinary iodine level was 198 micrograms/L of urine. CONCLUSION: The study showed that IDD continues to be prevalent in mild endemic proportions. Compared to the results of previous surveys, the IDD rates have declined in the last few years. However, it continues to be an important public health problem in Delhi. It is essential to monitor the iodine content of salt on a regular basis. IDD control activities should be strengthened in Delhi and repeat surveys should be done every 3-5 years to monitor the progress achieved in eliminating IDD.
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Yodo/deficiencia , Niño , Estudios Transversales , Enfermedades Carenciales/epidemiología , Enfermedades Endémicas , Humanos , India/epidemiología , Yodo/orina , PrevalenciaRESUMEN
BACKGROUND: The term 'Iodine deficiency disorders' (IDDs) reflects the spectrum of health effects due to iodine deficiency at all ages. So far, no survey for IDD has been carried out in the Andaman and Nicobar Islands (A&N). Therefore, we aimed to determine the status of IDDs at Car Nicobar Island and to assess the iodine content of salt available for consumption on the island. METHODS: The study population comprised tribal school children between 7 and 18 years of age in government schools of Car Nicobar, A&N. Children were selected from each school by the simple random sampling method using the random number table. The same sampling method was used for each school till completion of the desired sample size for that school. Casual urine samples (in screw-capped plastic bottles for iodine estimation) and blood samples (on No. 3 Whatman filter paper for TSH estimation) were collected from a randomly selected sub-sample of students. Salt samples for iodine estimation were collected from 'captains' (village headman) of each village and the headmasters of the schools and 'canteens' in government retail outlets in the villages. RESULTS: Of the 969 children surveyed, 160 (16.5%) had goitre. The prevalence was significantly more among females (23.6%) than males (9.7%). Analysis of 105 urine samples showed that the median urinary iodine excretion level was 7.0 micrograms/dl. The median TSH values in subjects was 5.7 mU/L. Fifty (82.5%) of the 54 salt samples had adequate iodine (> or = 15 parts per million). CONCLUSIONS: IDDs pose a mild-to-moderate public health problem in Car Nicobar Island. The supply of iodized salt and its iodine content was found to be satisfactory at the time of the study.
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Yodo/deficiencia , Adolescente , Niño , Femenino , Bocio/epidemiología , Humanos , India/epidemiología , Masculino , PrevalenciaRESUMEN
Using steady state/time resolved spectroscopic and electrochemical techniques the spectroscopic and photophysical studies were made on a novel synthesized selenophene compound SeP in nonpolar methylcyclohexane (MCH), polar aprotic acetonitrile (ACN) and polar protic ethanol (EtOH) solvents at the ambient temperature as well as at 77 K. Both from the studies on unimolecular and bimolecular photoprocesses this selenophene compound was found to possess several electronic levels, 1Bb, 1La, 1Lb (all are of pi pi* nature and 1Lb is hidden within 1La band envelop like the characteristics of most of the acenes) and 1(nO pi*) state arising due to carbonyl oxygen atom. In polar ACN environment this nO pi* state disappears because it moves within the envelop of intense 1La band due to large destabilization. Large overlapping of different band systems within the 1La band of SeP was confirmed from the observed depolarization effect. The lack of phosphorescence of SeP both in MCH and EtOH rigid glassy matrix at 77 K has been inferred due to large vibronic interactions between closely lying triplets of the corresponding 1nO pi* and 1Lb states. From the bimolecular investigations, it reveals that SeP acts as a good electron donor in presence of the well known electron acceptor 9 cyanoanthracene (9CNA). Transient absorption spectra measured by laser flash photolysis technique demonstrate the formation of ion-pair when the acceptor is excited. From the analysis of the fluorescence quenching data it seemingly indicates that the major contribution in the diminution of the fluorescence intensity of the acceptor 9CNA in presence of SeP is not only due to the photoinduced electron transfer (ET) but also originates from static type (instantaneous) quenching processes along with external heavy atom effect. The possibility of occurrence of photoinduced ET reaction in Marcus inverted region is hinted.
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Benzopiranos/química , Compuestos de Organoselenio/química , Fotoquímica/métodos , Acetonitrilos/química , Electroquímica , Etanol/química , Luminiscencia , Solventes/química , Espectrometría de Fluorescencia , TemperaturaRESUMEN
The effects of Co(II) and Mn (II) supplements at abundant as well as, deficient doses on in vitro synthesis of serum lipoproteins in rats maintained on normal and atherogenic diets were studied. While an adequate oral supplement of Co(II) or iv administration of Mn (II) at very low doses to the experimental rats fed on salt-free stock ration diet produces hyperlipidemic changes in increasing C/P ratio in serum and also the serum LP content. On the other hand, the animals on atherogenic diet supplemented with deficient Co(II) or excess Mn(II) results in a lowering of hyperlipidemia and hyperlipoproteinemia, with concomitant decrease in C/P ratio. Dietary lipids (eg. cholesterol, butter-fat etc.) vis-a-vis Mn (II) deficiency or Co(II) in excess reflect a homeostatic control mechanism for keeping the excess lipid in a state of solution as lipoprotein complexes. Deficient Co(II) or excess Mn (II) in turn, results in a decrease in protein synthesis and a relatively impaired rate of secretion of protein from liver to serum. Moreover, Mn (II) deficiency increases, while its abundance, significantly restricts 14C- labelled amino acid incorporation into alpha 2-lipoprotein molecules. Neither cobalt depletion, nor its adequate oral substitution help improvise the hepatic synthesis of alpha 2-apolipoproteins in experimental animals. This situation remains unaltered even by overloading the diets with saturated fats or by other atherogenic agents, instead of vegetable oils preferably rich in mono or dienoic fatty acids.
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Cobalto/administración & dosificación , Dieta Aterogénica , Lipoproteínas/biosíntesis , Manganeso/administración & dosificación , Animales , Lipoproteínas/sangre , Hígado/metabolismo , Masculino , RatasRESUMEN
It is estimated that 1,570 million people are at risk of iodine deficiency. Because of the wide spectrum of disorders that IDD includes, and lack of any obvious association between iodine deficiency and its health effects, IDD is not perceived as a major public health problem. For any disease to be effectively controlled, awareness at all levels from community to policy makers is necessary. This study was conducted to assess knowledge, beliefs and practices regarding iodine deficiency Disorders in Car Nicobar districts of Andaman and Nicobar Islands. The population is predominantly tribals involved in coconut plantations. All the village heads of the sixteen villages and parents of 10% of the school children examined for goiter were interviewed. Initial focus group discussions were conducted as no prior knowledge about local names for goitre or other related IDD information was available. The interview schedule was designed in English which was then translated into Hindi and Nicobarese and back translated into Hindi and English. A total of 114 persons were interviewed 60 males, 54 females. The local name for goiter was "Rulo" and 44% felt that it only affected females. No one had correct knowledge of the cause of goiter. About half of the respondents believed that these swellings caused problems. Sixty three (55.3%) of respondents believed that there was treatment, of which 33 said there was medical treatment, 18 respondents said traditional treatment by "LAM-EEN" and 12 felt that both therapies are required. Majority (85%) brought salt samples from the Government canteen. They did not now whether this salt was iodised. Salt was not washed before use and storage practice was satisfactory. The awareness about IDD needs reinforcement. At present the community is a passive participant in the I.D.D. Control Programme.
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Países en Desarrollo , Bocio Endémico/etiología , Conocimientos, Actitudes y Práctica en Salud , Yodo/deficiencia , Medicina Tradicional , Población Rural , Adulto , Niño , Femenino , Bocio Endémico/prevención & control , Humanos , India , Masculino , Persona de Mediana EdadRESUMEN
The authors analyse the results of examination of 154 patients who were admitted for the postcholecystectomy syndrome, 130 of them underwent retrograde cholangiopancreatography. The most common cause of the postcholecystectomy syndrome was residual or recurrent choledocholithiasis (38.5%), stricture of the major duodenal papilla or terminal part of the choledochus (34.6%). Treatment of the syndrome was differentiated and three methods were applied: operative--43 patients, endoscopic--45 patients, and combined--3 patients. Nasobiliary drainage was conducted in 63 patients in preparation for a surgical or endoscopic operation. Indications for the use of different methods of treatment are shown. With the use of the endoscopic techniques and combination of laparoscopic and endoscopic methods of surgical treatment, the number of laparotomies in patients with the postcholecystectomy syndrome reduced by one half and the operative intervention became less injurious.
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Colangitis/cirugía , Colecistectomía/efectos adversos , Enfermedades del Conducto Colédoco/cirugía , Complicaciones Posoperatorias/cirugía , Adulto , Colangitis/diagnóstico , Colangitis/etiología , Enfermedades del Conducto Colédoco/diagnóstico , Enfermedades del Conducto Colédoco/etiología , Humanos , Persona de Mediana Edad , Complicaciones Posoperatorias/diagnóstico , Complicaciones Posoperatorias/etiología , ReoperaciónRESUMEN
BACKGROUND: People in rural Bangladesh have a poor understanding of the link between use of contaminated surface water and disease. An inexpensive point-of-use water treatment agent was developed to purify surface water. METHODS: Surface water was collected from various sources in Bangladesh from February 2007 to January 2008. Microbiological and physicochemical parameters of raw and treated surface water were analysed. Water was treated with a mixture of alum potash, bleaching powder and lime, or with each agent individually. RESULTS: Raw water was contaminated with bacteria, the counts for total coliforms, faecal coliforms and faecal streptococci being 26,431, 14,548 and 240 colony-forming units (cfu) 100 ml(-1), respectively. These counts fell to 0 cfu 100 ml(-1) after treatment with the mixture. The count of artificially introduced Vibrio cholerae was also reduced to 0 cfu 100 ml(-1) after treatment. Treatment of raw water altered the pH from 6.90 to 6.87, turbidity from 21.61 to 3.55 nephelometric turbidity units (NTU), residual chlorine from 0 to 0.09 mg litre(-1), conductivity from 124.03 to 229.96 µS cm(-1), and total dissolved solids from 59.40 to 199.25 mg litre(-1). All these results of treatment were within the range recommended by the WHO as acceptable for drinking water. CONCLUSION: The mixture of alum potash, bleaching powder and lime described can be safely used to disinfect contaminated surface water to make it suitable for drinking and other household purposes in Bangladesh.
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Diarrea/prevención & control , Desinfección/métodos , Heces/microbiología , Vibrio cholerae/aislamiento & purificación , Purificación del Agua , Abastecimiento de Agua/normas , Compuestos de Alumbre , Bangladesh , Compuestos de Cloro , Diarrea/epidemiología , Diarrea/microbiología , Femenino , Conocimientos, Actitudes y Práctica en Salud , Humanos , Masculino , Salud Rural , Microbiología del Agua , Contaminación del Agua , Purificación del Agua/métodosRESUMEN
This study was directed to the measurement of the mechanical response of fetal membranes to physiologically relevant loading conditions. Characteristic mechanical parameters were determined and their relation to the microstructural constituents collagen and elastin as well as to the pyridinium cross-link concentrations analyzed. 51 samples from twelve fetal membranes were tested on a custom-built inflation device, which allows mechanical characterization within a multiaxial state of stress. Methods of nonlinear continuum mechanics were used to extract representative mechanical parameters. Established biochemical assays were applied for the determination of the collagen and elastin content. Collagen cross-link concentrations were determined by high-performance liquid chromatography measurements. The results indicate a distinct correlation between the mechanical parameters of high stretch stiffness and membrane tension at rupture and the biochemical data of collagen content and pyridinoline as well as deoxypyridinoline concentrations. No correlation was observed between the mechanical parameters and the elastin content. Moreover, the low stretch stiffness is, with a value of 105 ± 31 × 10(-3) N/ mm much higher for a biaxial state of stress compared to a uniaxial stress configuration. Determination of constitutive model equations leads to better predictive capabilities for a reduced polynomial hyperelastic model with only terms related to the second invariant, I 2, of the right Cauchy-Green deformation tensor. Relevant insights were obtained on the mechanical behavior of fetal membranes. Collagen and its cross-linking were shown to determine membrane's stiffness and strength for multiaxial stress states. Their nonlinear deformation behavior characterizes the fetal membranes as I 2 material.