Plasma C3d: Potential Marker for Disease Activity in Glomerulonephritis Patients

-- Monika Gandhi,
S C Tiwari, Ashok Kumar, A K Dinda and Nibhriti Das

Glomerulonephritis (GN) is defined as a disease characterized by intraglomerular inflammation, with or without cellular proliferation, associated with hematuria, proteinuria, reduced glomerular filtration rate (GFR) and hypertension. The diagnosis of kidney diseases is generally based on the results of kidney function tests like, blood urea, serum creatinine, urinary protein, etc. Complement-mediated tubular injury plays an important role in the progression of renal diseases. It has been previously reported that plasma levels of C3d significantly increase in response to accelerated C3 catabolism in certain inflammatory disorders like systemic lupus erythematosus (SEL), rheumatoid arthritis (RA) and infective endocarditis. It has also been suggested that C3d measurement can help in the assessment of disease activity. However, little is known about the direct relationship between C3d and kidney function test parameters in GN patients. In this paper, the plasma levels of C3d by ELISA in 117 normal individuals and 45 patients suffering from immune complex (IC)-mediated GN were measured. The relationship between plasma C3d and parameters like blood urea, serum creatinine and urinary protein was studied by Pearson Correlation Analysis. The plasma C3d levels were found to be significantly high in IC-mediated GN patients compared to normal healthy individuals (15.4 AU/ml vs. 8.74 AU/ml). IC patients had elevated C3d levels (76.2%) compared to normal individuals. C3d was found to have a significant positive correlation with creatinine, blood urea and urinary protein levels. Based on the findings, it can be concluded that elevated plasma C3d levels in case of GN patients affect renal function. Futhermore, the data suggests that plasma levels of C3d can be considered as possible markers for glomerulonephritis.

© 2007 IUP . All Rights Reserved.

Genetic Diversity and Pathogenic Variability among Colletotrichum gloeosporioides Penz. Isolates: The Causal Agent of Mango Anthracnose

-- A Sampathkumar,
N P Eswara Reddy,
K Hariprasad Reddy,
P Chowdappa and G Subhash Reddy

Seven isolates of Colletotrichum gloeosporioides causing mango anthracnose were collected from Agri Export Zone (AEZ) of Andhra Pradesh and from Tamil Nadu (Cg1 to Cg7). They were identified to species by using species-specific Polymerase Chain Reaction (PCR) primers for a ribosomal Internal Transcribed Spacer (ITS) region and morphological characters. The isolates were evaluated for their pathogenic variability on mango seedlings and genetic diversity with molecular techniques like Random Amplified Ploymorphic DNA (RAPD) and Internal Transcribed Spacer-Restriction Fragment Length Polymorphism (ITS-RFLP). In pathogenicity, isolate Cg2 recorded maximum Percent Disease Incidence (PDI) followed by Cg7 and both were highly virulent (>40 PDI). Cg1, Cg6 and Cg3 were moderately virulent (>30-40 PDI) and Cg4 and Cg3 were less virulent (<30 PDI). In RAPD, the five random primers OPA-03, 04, 19, 20 and OPD-13 were used and the seven isolates were grouped into three main clusters. Cluster I (Cg1 and Cg4), cluster II (IIa: Cg2 and Cg5; IIb: Cg3) and cluster III (Cg6 and Cg7). Clusters I and II have the genetic variability of 61%. Three clusters varied among themselves with a genetic variability of 84%. Out of five primers in RAPD, OPA 19 amplified two fragments of approximately 600 bp and 1400 bp for isolate Cg2 and one fragment of approximately 1300 bp for isolate Cg7. OPA 20 amplified 2700 bp fragment for Cg2 and 1400 bp for Cg7. These were unique fragments specific to highly virulent isolates Cg2 and Cg7. In ITS-RFLP, three enzymes RsaI, TaqI and PvuII produced uniform banding patterns for all isolates. However, enzymes HinfI and TruII differentiated the isolate Cg6 from others by unique banding pattern. The relationship between pathogenic variability and genetic diversity among the isolates of Colletotrichum gloeosporioides were discussed.

© 2007 IUP . All Rights Reserved.

Mulberry Protoplast Database System: A Comprehensive Interface for Research Data on Mesophyll Protoplasts Isolated from Mulberry Plants (Indian Cultivars)

-- Chakravarthy Rama and Ashish Mangalampalli

This paper investigates the type of mulberry cultivar and the enzyme taken during protoplast isolation from mesophyll cells of mulberry. Axenic shoot cultures of four mulberry cultivars (Morus indica) M5, S34, S54 and Mysore-local were cultured from nodal explants. The cultures were made at various treatment times and the levels of osmoticum for all the four cultivars. A comprehensive Mulberry Protoplast Database (MPD) was constructed from the results obtained, using query language. Moreover, since the database is user-friendly, and with the presence Graphical User Interface (GUI) menu, the user is at ease, and gets the results in a well-formatted and legible manner. Complex queries have been written in such a manner that facilitate the return of answers promptly, and without any trouble to the user. The protoplast database provides a fast, convenient and easy way to identify the yield of protoplasts and duration changes of a selected cultivar. Using the various queries of the MPD, it was concluded that protoplast yield in mulberry is dependent on the type of cultivar used and that 4-5 hours of incubation resulted in maximum protoplast yield, as compared to prolonged incubation duration in all the cultivars studied. Also, the protoplast yield was maximum in Mysore-local followed by M5, S34, and S54.

© 2007 IUP . All Rights Reserved.

Codon Volatility: An Efficient Tool to Detect the Purity of Genes

-- Uttam Kr. Mondal,
Saubashya Sur, Arnab Sen, and Asim Bothra

Plotkin et al. (2004), introduced a concept to detect positive and purifying selections of genes using a single genome. In this paper, the authors have used the widely used non-synonymous to synonymous substitution rate and Plotkin's method based on codon volatility for detecting natural selection. This study shows that Plotkin's method can efficiently detect purifying selection. This can be very useful in genomic research as well as targeted drug design.

© 2007 IUP . All Rights Reserved.

In vitro Study of DPPH Radical Scavenging Activity of Leaf Extracts of Physalis minima Linn.

-- A Ramteke, S Hasnua, S Boraha and R K Dasa

1,1-diphenyl-2-picrylhydrazyl (DPPH), a stable radical and investigated as reactive hydrogen acceptor, has been widely used for studying antioxidant properties of bioactive compounds isolated from the plant extracts. This paper investigates the DPPH radical scavenging activity of the leaf extract of Physalis minima Linn., which is expressed as percentage inhibition of DPPH free radical, using standard reference compounds—Butylated hydroxytoluene (BHT), Butylated hydroxy anisole (BHA) and Gallic acid. It was found that 50 mg/ml and 100 mg/ml of the extracts lowered the radical level to 57% and 80%, respectively. As 50% and above reduction of DPPH radical is considered significant, it suggests the scavenging capabilities of different components of the extract used in the present study. This further suggests that the different components of the extracts are good hydrogen donors but the concentration of the extract that resulted in 50% and above inhibition of DPPH radicals was found to be high as compared to the standard reference compound used. This might be due to the crude ethanol extract of leaves of Physalis minima Linn. used in the study. From the present findings it may be concluded that the radical scavenging activity is present only in a few components of the leaf extract of Physalis minima Linn. Hence, there is a need to purify and characterize the individual components present in the leaf extract responsible for the scavenging activity of DPPH radical.

© 2007 IUP . All Rights Reserved.

Sequence Variation in Human Succinate Dehydrogenase Genes: Evidence for Long-term Balancing Selection on SDHA

-- Bora E Baysal,
Elizabeth C Lawrence and Robert E Ferrell

Balancing selection operating for long evolutionary periods at a locus is characterized by the maintenance of distinct alleles because of a heterozygote or rare-allele advantage. The loci under balancing selection are distinguished by their unusually high polymorphism levels. In this report, we provide statistical and comparative genetic evidence suggesting that the SDHA gene is under long-term balancing selection. SDHA encodes the major catalytical subunit (flavoprotein, Fp) of the succinate dehydrogenase enzyme complex (SDH; mitochondrial complex II). The inhibition of Fp by homozygous SDHA mutations or by 3-nitropropionic acid poisoning causes central nervous system pathologies. In contrast, heterozygous mutations in SDHB, SDHC, and SDHD, the other SDH subunit genes, cause hereditary paraganglioma (PGL) tumors, which show constitutive activation of pathways induced by oxygen deprivation (hypoxia). We sequenced the four SDH subunit genes (10.8 kb) in 24 African American and 24 European American samples. We also sequenced the SDHA gene (2.8 kb) in 18 chimpanzees. Increased nucleotide diversity distinguished the human SDHA gene from its chimpanzee ortholog and from the PGL genes. Sequence analysis uncovered two common SDHA missense variants and refuted the previous suggestions that these variants originate from different genetic loci. Two highly dissimilar SDHA haplotype clusters were present in intermediate frequencies in both racial groups. The SDHA variation pattern showed statistically significant deviations from neutrality by the Tajima, Fu and Li, Hudson-Kreitman-Aguade, and Depaulis haplotype number tests. Empirically, the elevated values of the nucleotide diversity (% p = 0.231) and the Tajima statistics (D = 1.954) in the SDHA gene were comparable with the most outstanding cases for balancing selection in the African American population. The SDHA gene has a strong signature of balancing selection. The SDHA variants that have increased in frequency during human evolution might, by influencing the regulation of cellular oxygen homeostasis, confer protection against certain environmental toxins or pathogens that are prevalent in Africa.

© 2007 Bora E Baysal, Elizabeth C Lawrence and Robert E Ferrell; Licensee BioMed Central Ltd. This paper was earlier published in BMC Biology, Vol. 5, No. 1, p. 12. Reprinted with permission.