Phycochemical analyses and pharmacological activities of seven macroalgae of Arabian Sea (Northern coast line).

Seaweeds have been used as nutraceuticals because of certain metabolites present in some species including polyphenols. Seven species of seaweeds collected from the Karachi coast were screened for the first time both for phycochemical analysis and pharmacological activities. The phycochemicals quantified included phenols, flavonoids, tannins and saponins. Melanothamnus afaqhusainii showed the highest content of phenols (2.16mg GAE/g) while highest flavonoids were observed in Coelarthrum muelleri (4.59mg RE/g). Tannins were found in low amounts while saponins were observed as major constituents among the seaweeds ranging from 1.34-3.47% in Sargassum swartzii and Codium flabellatum, respectively. Saponins were not analysed in Rhodophyta due to gel formation. Pharmacological screening revealed analgesic and anti-inflammatory effects. Both the methods of analgesic activities have shown significant increase in reaction time when methanol extracts were used. The reason for delayed anti-inflammatory activity of Solieria robusta and C. muelleri was found correlating with its gel forming ability. While Cystoseira indica and C. flabellatum exhibited highly significant effect from 1st to 5th h. Results suggested that selected seaweeds had potential in combating both acute and chronic inflammation and pain and hence can be used for therapeutic efficacy.

Phycochemical and pharmacological studies on Ulva fasciata Delile.

Phycochemical and pharmacological studies were carried out on Ulva fasciata Delile. The ash content was found as 20.4812 % dry weight, moisture content 14.5514 %, total fat content as 0.1878% and 0.49341 %. Total carbohydrate was found as 54.5301-54.2246% dry weight, phenolic content as 0.022%, flavonoids found to be 0.0313% and tannins were 0.00003 %. Ulva fasicata showed central analgesic activity and significant anti-inflammatory activity at the dose of 400 mg/kg bw.

A Novel Colorimetric PCR-Based Biosensor for Detection and Quantification of Hepatitis B Virus.

Hepatitis B virus (HBV) can cause viral infection that attacks the liver and it is a major global health problem that puts people at a high risk of death from cirrhosis of the liver and liver cancer. HBV has infected one-third of the worldwide population, and 350 million people suffer from chronic HBV infection. For these reasons, development of an accurate, sensitive, and expedient detection method for diagnosing, monitoring, and assessing therapeutic response of HBV is very necessary and urgent for public health and disease control. Here we report a new strategy for detection of viral load quantitation of HBV based on colorimetric polymerase chain reaction (PCR) with DNAzyme-containing probe. The special DNAzyme adopting a G-quadruplex structure exhibited peroxidase-like activity in the presence of hemin to report colorimetric signal. This method has shown a broad range of linearity and high sensitivity. This study builds an important foundation to achieve the specific and accurate detection level of HBV DNA with a low-cost and effective method in helping diagnosing, preventing and protecting human health form HBV all over the world, and especially in developing countries.

Sequence-Specific Biosensing of DNA Target through Relay PCR with Small-Molecule Fluorophore.

Polymerase chain reaction coupled with signal generation offers sensitive recognition of target DNA sequence; however, these procedures require fluorophore-labeled oligonucleotide probes and high-tech equipment to achieve high specificity. Therefore, intensive research has been conducted to develop reliable, convenient, and economical DNA detection methods. The relay PCR described here is the first sequence-specific detection method using a small-molecule fluorophore as a sensor and combines the classic 5'-3' exonuclease activity of Taq polymerase with an RNA mimic of GFP to build a label-free DNA detection platform. Primarily, Taq polymerase cleaves the 5' noncomplementary overhang of the target specific probe during extension of the leading primer to release a relay oligo to initiate tandem PCR of the reporting template, which encodes the sequence of RNA aptamer. Afterward, the PCR product is transcribed to mRNA, which could generate a fluorescent signal in the presence of corresponding fluorophore. In addition to high sensitivity and specificity, the flexibility of choosing different fluorescent reporting signals makes this method versatile in either single or multiple target detection.

A novel colorimetric PCR-based biosensor for detection and quantification of hepatitis B virus.

Hepatitis B virus (HBV) can cause viral infection that attacks the liver and it is a major global health problem that put people at a high risk of death from cirrhosis of the liver and liver cancer. HBV has infected one third of the worldwide population, and 350 million people suffer from chronic HBV infection. For these reasons, development of an accurate, sensitive and expedient detection method for diagnosing, monitoring and assessing therapeutic response of HBV is very necessary and urgent for public health and disease control. Here we report a new strategy for detection of viral load quantitation of HBV based on colorimetric polymerase chain reaction (PCR) with DNAzyme-containing probe. The special DNAzyme adopting a G-quadruplex structure exhibited peroxidase-like activity in the presence of hemin to report colorimetric signal. This method has shown a broad range of linearity and high sensitivity. This study builds important foundation to achieve the specific and accurate detection level of HBV DNA with a low-cost and effective method in helping diagnosing, preventing and protecting human health form HBV generally all over the world and especially in developing countries.

In vitro selection of DNA-cleaving deoxyribozyme with site-specific thymidine excision activity.

Single-nucleotide polymorphisms, either inherited or due to spontaneous DNA damage, are associated with numerous diseases. Developing tools for site-specific nucleotide modification may one day provide a way to alter disease polymorphisms. Here, we describe the in vitro selection and characterization of a new deoxyribozyme called F-8, which catalyzes nucleotide excision specifically at thymidine. Cleavage by F-8 generates 3'- and 5'-phosphate ends recognized by DNA modifying enzymes, which repair the targeted deoxyribonucleotide while maintaining the integrity of the rest of the sequence. These results illustrate the potential of DNAzymes as tools for DNA manipulation.

Signal amplification of glucosamine-6-phosphate based on ribozyme glmS.

Ribozyme glmS based isothermal amplification assay is developed for the colorimetric detection of glucosamine-6-phosphate (GlcN6P). Upon binding to the metabolite target GlcN6P, self-cleavage of glmS ribozyme is initiated to release RNA fragment that can trigger the cascade signal amplification to release large amount of G-quadruplex DNAzymes as reporter for colorimetric detection. Given the importance of GlcN6P for cell wall biosynthesis, the glmS riboswitch has become a new drug target for the development of antibiotics. This assay not only offers a convenient detection of GlcN6P with high specificity and sensitivity, but also provides a platform for high-throughput screening of antibiotics based on glmS riboswitches.

Template-directed chemical ligation to obtain 3'-3' and 5'-5' phosphodiester DNA linkages.

Up to now, the direct ligation of two DNA fragments with opposite directions to obtain 3'-3' or 5'-5' phosphate ester bonds is still challenging. The only way to obtain DNA oligonucleotides containing a 3'-3' or 5'-5' inversion of polarity sites is based on professional DNA chemical synthesis. Herein, we demonstrate a convenient template-directed chemical ligation that enables 3'-3' and 5'-5' linkages of two DNA oligonucleotides. This method is based on the assembly of two oligonucleotides on a template in opposite directions through forming antiparallel and parallel duplexes simultaneously, followed by coupling with N-Cyanoimidazole under mild condition. Moreover, on the basis of DNA oligonucleotides with 5'-5' linkage obtained through our template-directed chemical ligation, we developed a new cDNA display technique for in vitro selection of functional polypeptides.

DNA based identification of medicinal materials in Chinese patent medicines.

Chinese patent medicines (CPM) are highly processed and easy to use Traditional Chinese Medicine (TCM). The market for CPM in China alone is tens of billions US dollars annually and some of the CPM are also used as dietary supplements for health augmentation in the western countries. But concerns continue to be raised about the legality, safety and efficacy of many popular CPM. Here we report a pioneer work of applying molecular biotechnology to the identification of CPM, particularly well refined oral liquids and injections. What's more, this PCR based method can also be developed to an easy to use and cost-effective visual chip by taking advantage of G-quadruplex based Hybridization Chain Reaction. This study demonstrates that DNA identification of specific Medicinal materials is an efficient and cost-effective way to audit highly processed CPM and will assist in monitoring their quality and legality.

Autosomal recessive congenital cataract in consanguineous Pakistani families is associated with mutations in GALK1.

PURPOSE: To identify the pathogenic mutations responsible for autosomal recessive congenital cataracts in consanguineous Pakistani families. METHODS: All affected individuals underwent detailed ophthalmologic and medical examination. Blood samples were collected and genomic DNA was extracted. A genome-wide scan was performed with polymorphic microsatellite markers on genomic DNA from affected and unaffected family members and logarithm of odds (LOD) scores were calculated. All coding exons of galactokinase (GALK1) were sequenced to identify pathogenic lesions. RESULTS: Clinical records and ophthalmological examinations suggested that affected individuals have nuclear cataracts. Linkage analysis localized the critical interval to chromosome 17q with a maximum LOD score of 5.54 at theta=0, with D17S785 in family PKCC030. Sequencing of GALK1, a gene present in the critical interval, identified a single base pair deletion: c.410delG, which results in a frame shift leading to a premature termination of GALK1: p.G137fsX27. Additionally, we identified a missense mutation: c.416T>C, in family PKCC055 that results in substitution of a leucine residue at position 139 with a proline residue: p.L139P, and is predicted to be deleterious to the native GALK1 structure. CONCLUSIONS: Here, we report pathogenic mutations in GALK1 that are responsible for autosomal recessive congenital cataracts in consanguineous Pakistani families.

A new locus for autosomal recessive congenital cataract identified in a Pakistani family.

PURPOSE: To identify the disease locus for autosomal recessive congenital cataract in a consanguineous Pakistani family. METHODS: All affected individuals underwent detailed ophthalmologic and medical examination. Blood samples were collected and DNA was extracted. A genome-wide scan was performed with polymorphic microsatellite markers on genomic DNA from affected and unaffected family members, and logarithm of odds (LOD) scores were calculated. RESULTS: The clinical records and ophthalmological examinations suggested that all affected individuals have nuclear cataracts. Maximum LOD scores of 5.01, 4.38, and 4.17 at theta=0 were obtained with markers D7630, D7S657, and D7S515, respectively. Fine mapping refined the critical interval and suggested that markers in a 27.78 cM (27.96 Mb) interval are flanked by markers D7S660 and D7S799, which co-segregate with the disease phenotype in family PKCC108. CONCLUSIONS: We have identified a new locus for autosomal recessive congenital cataract, localized to chromosome 7q21.11-q31.1 in a consanguineous Pakistani family.

A variant form of Oguchi disease mapped to 13q34 associated with partial deletion of GRK1 gene.

PURPOSE: The purpose of this paper is to map the locus for a variant form of Oguchi disease in a Pakistani family and to identify the causative mutation. METHODS: Family 61029 was ascertained in the Punjab province of Pakistan. It includes three 13- to 19-year-old patients with night blindness and 12 unaffected family members. A complete ophthalmological examination including fundus photography and electroretinography (ERG) was performed on each family member. A genome-wide scan was performed using microsatellite markers at about 10 cM intervals, and two-point lod scores were calculated. Polymerase chain reaction (PCR) cycle dideoxynucleotide sequencing was used to screen candidate genes inside the linked region for mutations and to delineate the deletion. Multiplex PCR and long template PCR were used to detect deletions and to define the size of deletions. Evaluation of fundus changes and ERG, lod score estimation, and identification of a mutation in the GRK1 gene were carried out. RESULTS: All patients had night blindness since early childhood. Irregular coarse pigmentation was observed in the peripheral retina of each patient. The fundus appearance before and after 4 h of dark adaptation was similar except that the peripheral retinal pigmentary changes were slightly less evident after extended dark adaptation. Minimal or no rod function with normal cone function on ERG recordings were detected in all three affected members. The rod showed slow recovery to nearly normal amplitude after 4 h in the dark ERG in one individual but not in two other patients. A genome-wide scan showed linkage only to D13S285. Fine mapping defined a region from D13S1315 to 13qter, with a lod score of 2.89 at theta=0 shown by D13S285 and 2.90 at theta=0 by the D13S261-D13S285-D13S1295-D13S293 haplotype. Analysis of the GRK1 gene, which is included in this interval, identified a c.827+623_883del mutation. This intragenic deletion cosegregates with the disease in the family and is only homozygous in affected individuals. This mutation was not detected in 96 controls. CONCLUSIONS: The retinal disease in the family reported here has several features differing from typical Oguchi disease, including an atypical Mizuo-Nakamura phenomenon and a non-recordable rod ERG even after 4 h of dark adaptation. Normal visual acuity, normal caliber of retinal blood vessels, and normal cone response on ERG recording suggest retinal dysfunction rather than degeneration (i.e., a variant form of Oguchi disease but unlikely to be retinitis pigmentosa). The disease in the Pakistani family localizes to 13q34 and is caused by a novel deletion including Exon 3 of the GRK1 gene.

Mutations in betaB3-crystallin associated with autosomal recessive cataract in two Pakistani families.

PURPOSE: To identify the disease locus for autosomal recessive congenital cataracts in consanguineous Pakistani families. METHODS: Two Pakistani families were ascertained, patients were examined, blood samples were collected, and DNA was isolated. A genome-wide scan was performed using >382 polymorphic microsatellite markers on genomic DNA from affected and unaffected family members. Two-point lod scores were calculated, haplotypes were formed by inspection, and candidate genes were sequenced. Real-time quantitative PCR techniques were used to determine the mRNA levels, and molecular modeling was performed to gain a better understanding of the significance of the disease-causing mutation. RESULTS: In the genome-wide scan, maximum lod scores of 2.67 and 2.77 for family 60004 and 2.02 and 2.04 for family 60006 were obtained for markers D22S539 and D22S315, respectively. The linked region, 22.7 cM (10 Mb) flanked by markers D22S420 and D22S1163, contains the beta-crystallin gene cluster including the genes CRYBA4, CRYBB1, CRYBB2, and CRYBB3. Sequencing of these genes showed a G-->C transition in exon 6 of CRYBB3 resulting in a p.G165R change in the betaB3-crystallin protein that cosegregates with the disease in both families. Real-time PCR analysis suggested that betaB3-crystallin mRNA levels approximate those of other betagamma-crystallins. Molecular modeling predicted changes in electrostatic potential that would be expected to reduce the stability of the fourth Greek-key motif, and hence the entire protein, dramatically. CONCLUSIONS: For the first time, a mutation in CRYBB3 is reported in two consanguineous Pakistani families with autosomal recessive congenital cataracts.

A new locus for autosomal recessive nuclear cataract mapped to chromosome 19q13 in a Pakistani family.

PURPOSE: To identify the disease locus of autosomal recessive congenital nuclear cataracts in a consanguineous Pakistani family. METHODS: A large Pakistani family with multiple individuals affected by autosomal recessive congenital cataracts was ascertained. Patients were examined, blood samples were collected, and DNA was isolated. A genome-wide scan was performed using 382 polymorphic microsatellite markers on genomic DNA from affected and unaffected family members. Two-point lod scores were calculated, and haplotypes were formed by inspection. RESULTS: In the genome-wide scan, a maximum lod score of 2.89 was obtained for marker D19S414 on 19q13. Fine mapping using D19S931, D19S433, D19S928, D19S225, D19S416, D19S213, D19S425, and D19S220 markers from the Généthon database showed that markers in a 14.3-cM (12.66-Mb) interval flanked by D19S928 and D19S420 cosegregated with the cataract locus. Lack of homozygosity further suggests that the cataract locus may lie in a 7-cM (4.3-Mb) interval flanked by D19S928 proximally and D19S425 distally. On fine mapping, a maximum lod score of 3.09 was obtained with D19S416 at theta = 0. CONCLUSIONS: Linkage analysis identified a new locus for autosomal recessive congenital nuclear cataracts on chromosome 19q13 in a consanguineous Pakistani family.