RESUMEN
Zika virus belongs to family of viruses 'Flaviviridae' and spreads mostly by daytime-active Aedes mosquitoes. The resulting infection is known as Zika fever. It is usually asymptomatic or often causes mild symptoms, which are very similar to dengue fever. The Aedes aegypti mosquito is also responsible for dengue and chikungunya viruses. Zika virus can spread by crossing the placental barrier from a pregnant mother to a fetus, which can result in microcephaly, severe brain malformations including Guillain-Barre syndrome (GBS), and other birth defects. Until now, there is no specific treatment of Zika fever disease, and Zika virus illness cannot be prevented by medications or vaccines. According to WHO, no vaccine is likely to be available until 2020. The only way of preventing this disease is to prevent the mosquito bites. This article presents the history of Zika virus, its reported cases including microcephaly and GBS, and a comparison of its symptoms with those of dengue and chikungunya diseases, as well as preventive measures. With advances in research and technology, knowledge about the Zika virus has grown, yet some questions remain unanswered regarding Zika virus's genetic diversity, pathophysiology, transmission vectors and reservoirs, potential synergetic of coinfection with other related arboviruses, and treatment. These problems highlight the need for further research to achieve adequate the surveillance, infection management, optimized treatment, and public health mediations in Zika virus outbreaks. This article contributes to our understanding of the disease mechanism, genome structure, diagnosis, transmission, and preventive strategies to combat Zika virus infection.
Asunto(s)
Infección por el Virus Zika/epidemiología , Infección por el Virus Zika/transmisión , Virus Zika/fisiología , Virus Zika/patogenicidad , Animales , Ensayo de Inmunoadsorción Enzimática , Femenino , Genoma Viral , Síndrome de Guillain-Barré/etiología , Síndrome de Guillain-Barré/virología , Humanos , Masculino , Mosquitos Vectores , Reacción en Cadena de la Polimerasa , Embarazo , Primates/virología , Infección por el Virus Zika/diagnósticoRESUMEN
Retinitis pigmentosa (RP) is the most frequent genetically and clinically heterogeneous inherited retinal degeneration. To date, more than 80 genes have been identified that cause autosomal dominant, autosomal recessive and X linked RP. However, locus and allelic heterogeneity of RP has not been fully captured yet. This heterogeneity and lack of an accurate genotype phenotype correlation makes molecular dissection of the disease more difficult. The present study was designed to characterize the underlying pathogenic variants of RP in Pakistan. For this purpose, a large consanguineous family with RP phenotype showing autosomal recessive mode of inheritance was selected after a complete ophthalmological examination. Next generation sequencing was used for the identification of molecular determinant followed by Sanger-sequencing for confirmation. After sequence analysis a novel homozygous missense mutation, (c.602 C > T) in exon 4 of the RDH5 gene (MIM: 601617) was identified. This mutation resulted in substitution of phenyl alanine for serine at amino acid 201 (p.Ser201Phe) of the RDH5 gene. The same mutation was not detected in the 200 ethnically-matched control samples by Sanger sequencing. The identified mutant allele segregated in homozygous fashion in all the affected individuals of pedigree. Identification of this mutation reveals the allelic heterogeneity of RDH5 in patients with RP phenotype. The findings of this study demonstrate the clinical significance of next generation sequencing to understand the molecular basis of diseases and would help to reveal new proteins and their function in visual cycle will pave the way for early diagnosis, genetic counseling and better therapeutic inventions.
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Oxidorreductasas de Alcohol/genética , Oxidorreductasas de Alcohol/fisiología , Retinitis Pigmentosa/genética , Adolescente , Adulto , Alelos , Consanguinidad , Proteínas del Ojo/genética , Familia , Femenino , Estudios de Asociación Genética , Secuenciación de Nucleótidos de Alto Rendimiento , Homocigoto , Humanos , Masculino , Persona de Mediana Edad , Mutación , Mutación Missense/genética , Pakistán , Linaje , Polimorfismo de Nucleótido Simple/genéticaRESUMEN
Carrageenan is a natural polysaccharide extracted from edible red seaweeds of Rhodophycea class. It has been used as a viscosity increasing or gelling agent for prolonged and controlled drug release, food, pharmaceuticals and other industries. However, in spite of wide range of applications, carrageenan has some drawbacks and adverse effects on the biological systems, so its modifications with natural and synthetic polymers are carried out. This review article presents different sources and properties of carrageenans with special emphasis on natural polymer based carrageenan blends and composites and their applications in controlled drug delivery system, wound dressing and tissue engineering because of their biodegradability and biocompatibility, food industry as thickening/gelling materials, cosmeceuticals and making polyelectrolyte complexes.
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Biopolímeros/química , Carragenina/química , Carragenina/síntesis química , Técnicas de Química Sintética/métodos , Animales , Fenómenos Químicos , HumanosRESUMEN
Gynaecological malignancies contribute significantly to cancer burden and have a higher rate of mortality and morbidity. The aim of this retrospective study was to determine the pattern of gynaecological malignancies identified between January, 2000 and December, 2011, at the Centre for Nuclear Medicine and Radiotherapy (CENAR). At CENAR 5,072 female patients were registered with different malignancies, of which 632 cases were gynaecological malignancies. Ovarian cancer (47%) was the most common gynaecological malignancy, followed by cervical cancer (29%), uterine cancer (14%), vulvar and vaginal cancer (6%), and gestational trophoblastic neoplasm (4%). Of the ovarian cancer cases, 72.5% had epithelial while 26.5% had non-epithelial cancer. Squamous cell carcinoma was 75.9% in cervix and 87.8% in vulva and vagina while endometrial carcinoma (75.9%) was more frequent in uterus. For gestational trophoblastic neoplasm, 69.2% of patients had choriocarcinoma. Ovarian cancer was the most common type for the age range of 50-59 years. In the case of cervical and gestational trophoblastic neoplasm the majority of patients presented at the ages of 40-49 and 30-39 years while uterus, vulvar and vaginal tumor presented in the elderly (>60 years). Thus, ovarian cancer is the leading gynecological malignancy in Pakistan.
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Collagen is mostly found in fibrous tissues such as tendons, ligaments and skin. Collagen makes up approximately 30% of the proteins within the body. These are tough and strong structures found all over the body: in bones, tendons and ligaments. Collagen being the most abundant protein provides tensile strength via cell matrix interactions to tissue architecture. Biomimetic materials of collagen origin gained wide spread acceptance in clinical applications. Vitamin C deficiency causes scurvy a serious and painful disease in which defective collagen prevents the formation of strong connective tissue, gums deteriorate and bleed, with loss of teeth; skin discolors, and wounds do not heal. Effective collagens prevent the manifestation of such disorders. Polyurethanes on the other hand are frequently used for various applications as they offered in wide-ranging of compositions, properties and complex structures. Collagen/PU bio-composites have potential array for biomedical applications. Considering versatile properties of the elongated fibrils and wide industrial and biomedical applications including biocompatibility of polyurethane, this review shed a light on collagen based polyurethane materials with their potential applications especially focusing the bio-medical field.