Association of timing of congenital diaphragmatic hernia repair with survival and morbidity for patients not requiring extra-corporeal life support

BACKGROUND

While physiologic stabilization followed by repair has become the accepted paradigm for management of congenital diaphragmatic hernia (CDH), few studies have examined the effect of incremental changes in operative timing on patient outcomes. We hypothesized that later repair would be associated with higher morbidity and mortality.

METHODS

Data were queried from the CDH Study Group (CDHSG) from 2007-2020. Patients with chromosomal or cardiac abnormalities and those who were never repaired or required pre-repair extra-corporeal life support (ECLS) were excluded. Time to repair was analyzed both as a continuous variable and by splitting the cohort into top/bottom percentiles. The primary outcome of interest was in-hospital mortality. Secondary outcomes included need for and duration of post-repair ventilatory and nutritional support.

RESULTS

A total of 4,104 CDH infants were included. Median time to repair was 4 days (IQR 2-6). On multivariable analysis, high-risk (CDHSG stage C/D) defects and lower birthweight predicted later repair. Overall, in-hospital mortality was 6%. On univariate analysis, there was no difference in the number of days to repair between survivors and non-survivors. On risk-adjusted analysis, single-day changes in day of repair were not associated with increased mortality. Later repair was associated with longer time to reach full oral feeds, increased post-repair ventilator days, and increased need for tube feeds and supplementary oxygen at discharge.

CONCLUSIONS

For infants with isolated CDH not requiring pre-operative ECLS, there is no difference in mortality based on timing of repair, but single-day delays in repair are associated with increased post-repair duration of ventilatory and nutritional support.

A randomized controlled prospective study to assess the role of subconjunctival bevacizumab in primary pterygium surgery in Indian patients

BACKGROUND

Pterygium is an ocular surface disorder with prevalence rates ranges from 0.3% to 29% in different parts of the world. Vascular endothelial growth factor (VEGF) has been detected in increased amounts in pterygium epithelium, compared with normal conjunctiva. Bevacizumab is a recombinant, humanized anti-VEGF antibody suggested as a possible adjunctive therapy for pterygium excision that appears to have a role in prevention of recurrence. We conducted this study to evaluate the role of subconjunctival bevacizumab in primary pterygium surgery in Indian patients.

METHODS

In this randomized prospective clinical study, the patients were randomized into two groups of 30 patients each. Study group received 1.25 mg/0.05 ml subconjunctival bevacizumab 1 week before pterygium surgery with conjunctival autograft. Control group received 1.25 mg (0.05 ml) subconjunctival normal saline 1 week prior to pterygium surgery with conjunctival autograft. Patients were followed up at day 1, day 7, 1 month and 3 months. The main outcome measures were morphology of pterygium after injection, intra-operative ease, recurrence of pterygia, and any complications.

RESULTS

After giving bevacizumab, there was statistically significant improvement in grade, color intensity, size of pterygium, and symptoms of patients. Intra-operatively, less bleeding was observed by the surgeon. No statistically significant difference regarding reduction in astigmatism, improvement of visual acuity, and complications were observed in two groups. Recurrence was noted in five patients (8.33%) in total study population at the end of 3 months. It was present in two patients (6.67%) in Group A and three patients (10%) in Group B.

CONCLUSION

Single preoperative administration of subconjunctival injection bevacizumab given 1 week before the pterygium excision with conjunctival autograft decreases the vascularity of newly formed blood vessels, hence may decrease recurrence rate though not in our study.

Way toward "dietary pesticides": molecular investigation of insecticidal action of caffeic acid against Helicoverpa armigera

Bioprospecting of natural molecules is essential to overcome serious environmental issues and pesticide resistance in insects. Here we are reporting insights into insecticidal activity of a plant natural phenol. In silico and in vitro screening of multiple molecules supported by in vivo validations suggested that caffeic acid (CA) is a potent inhibitor of Helicoverpa armigera gut proteases. Protease activity and gene expression were altered in CA-fed larvae. The structure-activity relationship of CA highlighted that all the functional groups are crucial for inhibition of protease activity. Biophysical studies and molecular dynamic simulations revealed that sequential binding of multiple CA molecules induces conformational changes in the protease(s) and thus lead to a significant decline in their activity. CA treatment significantly inhibits the insect's detoxification enzymes, thus intensifying the insecticidal effect. Our findings suggest that CA can be implicated as a potent insecticidal molecule and explored for the development of effective dietary pesticides.

Differential protease activity augments polyphagy in Helicoverpa armigera

Helicoverpa armigera (Lepidoptera: Noctuidae) and other polyphagous agricultural pests are extending their plant host range and emerging as serious agents in restraining crop productivity. Dynamic regulation, coupled with a diversity of digestive and detoxifying enzymes, play a crucial role in the adaptation of polyphagous insects. To investigate the functional intricacy of serine proteases in the development and polyphagy of H. armigera, we profiled the expression of eight trypsin-like and four chymotrypsin-like phylogenetically diverse mRNAs from different life stages of H. armigera reared on nutritionally distinct host plants. These analyses revealed diet- and stage-specific protease expression patterns. The trypsins expressed showed structural variations, which might result in differential substrate specificity and interaction with inhibitors. Protease profiles in the presence of inhibitors and their mass spectrometric analyses revealed insight into their differential activity. These findings emphasize the differential expression of serine proteases and their consequences for digestive physiology in promoting polyphagy in H. armigera.

Mitochondrial haplotypes reveal a strong genetic structure for three Indian sheep breeds

This survey represents the first characterization of mitochondrial DNA diversity within three breeds of Indian sheep (two strains of the Deccani breed, as well as the Bannur and Garole breeds) from different geographic regions and with divergent phenotypic characteristics. A 1061-bp fragment of the mitochondrial genome spanning the control region, a portion of the 12S rRNA gene and the complete phenyl tRNA gene, was sequenced from 73 animals and compared with the corresponding published sequence from European and Asian breeds and the European Mouflon (Ovis musimon). Analysis of all 156 sequences revealed 73 haplotypes, 52 of which belonged to the Indian breeds. The three Indian breeds had no haplotypes in common, but one Indian haplotype was shared with European and other Asian breeds. The highest nucleotide and haplotype diversity was observed in the Bannur breed (0.00355 and 0.981 respectively), while the minimum was in the Sangamneri strain of the Deccani breed (0.00167 and 0.882 respectively). All 52 Indian haplotypes belonged to mitochondrial lineage A. Therefore, these Indian sheep are distinct from other Asian and European breeds studied so far. The relationships among the haplotypes showed strong breed structure and almost no introgression among these Indian breeds, consistent with Indian sheep husbandry, which discourages genetic exchange between breeds. These results have implications for the conservation of India's ovine biodiversity and suggest a common origin for the breeds investigated.

Development of an integrated intraspecific map of chickpea (Cicer arietinum L.) using two recombinant inbred line populations

A composite intraspecific linkage map of chickpea was developed by integrating individual maps developed from two F(8:9) RIL populations with one common parent. Different molecular markers viz. RAPD, ISSR, RGA, SSR and ASAP were analyzed along with three yield related traits: double podding, seeds per pod and seed weight. A total of 273 markers and 186 RILs were used to generate the map with eight linkage groups at a LOD score of >/=3.0 and maximum recombination fraction of 0.4. The map spanned 739.6 cM with 230 markers at an average distance of 3.2 cM between markers. The predominantly used SSR markers facilitated identification of homologous linkage groups from the previously published interspecific linkage map of chickpea and confirmed conservation of the SSR markers across the two maps as well as the variation in terms of marker distance and order. The double podding gene was tagged by the markers NCPGR33 and UBC249z at 2.0 and 1.1 cM, respectively. Whereas, seeds per pod, was tagged by the markers TA2x and UBC465 at 0.1 and 1.8 cM, respectively. Eight QTLs were identified that influence seed weight. The joint map approach allowed mapping a large number of markers with a moderate coverage of the chickpea genome and few linkage gaps.

Molecular mapping of stem and leaf rust resistance in wheat

Stem rust caused by Puccinia graminis f. sp. tritici Eriks and Henn and leaf rust caused by Puccinia triticina Rob. ex Desm. are major constraints to wheat production worldwide. In the present study, F(4)-derived SSD population, developed from a cross between Australian cultivars 'Schomburgk' and 'Yarralinka', was used to identify molecular markers linked to rust resistance genes Lr 3 a and Sr 22. A total of 1,330 RAPD and 100 ISSR primers and 33 SSR primer pairs selected ob the basis of chromosomal locations of these genes were used. The ISSR marker UBC 840(540) was found to be linked with Lr 3 a in repulsion at a distance of 6.0 cM. Markers cfa 2019 and cfa 2123 flanked Sr 22 at a distance of 5.9 cM (distal) and 6.0 cM (proximal), respectively. The use of these markers in combination would predict the presence or absence of Sr 22 in breeding populations. A previously identified PCR-based diagnostic marker STS 638 linked to Lr 20 was validated in this population. This marker showed a recombination value of 7.1 cM with Lr 20.

Pattern of intraocular pressure in epidemic dropsy in India

This study was conducted to report on the intraocular pressure (IOP) pattern in patients with epidemic dropsy. Two hundred and thirty proven cases of epidemic dropsy were sent for ocular examination. We measured IOP by applanation tonometry at different intervals. Patients were followed up until 24 weeks. Intraocular pressure of more than 22 mm of Hg was detected in 10.86% patients at the start of the study. However, at 12 weeks only 0.43% patients needed medication for control of IOP. None required medication for IOP control after 20 weeks. The rise of IOP in this case series of epidemic dropsy appeared to be a transient phenomenon and drugs needed to be titrated on a weekly basis.

Detection of Genetic Variability in Pearl Millet Downy Mildew (Sclerospora graminicola) by AFLP

Downy mildew, caused by Sclerospora graminicola, is an economically important disease of pearl millet in the semiarid regions of Asia and Africa. Amplified restriction fragment length polymorphism (AFLP) was used to detect the extent of genomic variation among 19 fungal isolates from different cultivars of pearl millet grown in various regions of India. Fourteen AFLP primer combinations produced 184 polymorphic bands. An unweighted pair-group method of averages cluster analysis represented by dendrogram and principal coordinate analysis separated the mildew collections into four distinct groups. Isolates having characteristic opposite mating abilities, geographic relatedness, virulence, common host cultivars, and changes through asexual generations reflected heterogeneity of the pathogen. The use of AFLP to detect genetic variation is particularly important in selecting mildew isolates to screen breeding material for identification of resistant millet and monitoring changes in S. graminicola in relation to changes in host for effective disease management.

Acute lymphocytic leukemia presenting as masquerade syndrome

An 11-year-old child presented with plastic iridocyclitis and hypopyon. Subsequent paracentesis revealed leukemic infiltrates. A bone marrow biopsy confirmed the diagnosis of acute lymphocytic leukemia. Because of this unusual case of leukemic hypopyon, we advocate anterior chamber paracentesis and pediatrician referral in all cases of refractory uveitis.

Molecular marker analysis of protein content using PCR-based markers in wheat

Grain protein concentration (GPC) of hexaploid wheat is one of the important factors that determines the end-product quality as well as playing a pivotal role in human nutrition. In an attempt to identify PCR-based DNA markers linked to GPC, 106 recombinant inbred lines (RILs) were developed from a cross between two wheat cultivars PH132 and WL711, which differ significantly in GPC, by the single seed descent method. The RILs were phenotyped for GPC at two diverse agroclimatic locations, namely Pune and Ludhiana, to study the influence of genotype and environment interactions on this trait. The parents were screened with 85 inter simple sequence repeat (ISSR) primers and 350 random primers. The selective genotyping and whole population analysis revealed nine DNA markers associated with the trait. Three markers (UBC8441100, UBC8801000, and OPA4800) were observed to be associated with the trait in both locations, whereas two markers (OPH41400) and UBC873750) werefound to be specific to Pune, and four markers (OPM5870, OPO10870, OPV141200, and UBC8251000) were specific to Ludhiana. Together five markers at the Pune location representing five QTLs and seven markers at Ludhiana representing four QTLs accounted for 13.4 and 13.5% of total phenotypic variation, respectively. This study clearly demonstrates that GPC is highly influenced by the environment, and the applicability of ISSR and RAPD markers in finding regions on chromosomes associated with quantitative characters in wheat such as GPC.

Genetic diversity across natural populations of three montane plant species from the Western Ghats, India revealed by intersimple sequence repeats

We analysed genetic diversity across the natural populations of three montane plant species in the Western Ghats, India; Symplocos laurina, Gaultheria fragrantissima and Eurya nitida using intersimple sequence repeat (ISSR) markers. These markers revealed genetic diversity within the populations of these plants from Nilgiri and also between two populations of S. laurina from Nilgiri and Amboli. Genetic variation within and between populations was analysed using various parameters such as total heterozygosity (HT), heterozygosity within population (HS), diversity between populations (DST), coefficient of population differentiation (GST), genetic distance (D) and gene flow (Nm). Total heterozygosity (HT) was higher for S. laurina (0.238) than for G. fragrantissima (0.172) and E. nitida (0.182). Two populations of S. laurina, separated by > 1000 km, showed a high within-population variation (53.7%) and a low gene flow (Nm = 0.447). upgma phenograms depicted a tendency of accessions to group according to their geographical locations in all the three plant species. The insight gained into the genetic structure of these plant populations might have implications in developing in situ and ex situ conservation strategies.

Comparative analysis of genetic diversity among Indian populations of Scirpophaga incertulas by ISSR-PCR and RAPD-PCR

Genetic variation between 28 Indian populations of the rice pest, Scirpophaga incertulas was evaluated using inter-simple sequence repeats (ISSR)-PCR assay. Nine SSR primers gave rise to 79 amplification products of which 67 were polymorphic. A dendrogram constructed from this data indicates that there is no geographical bias to the clustering and that gene flow between populations appears to be relatively unrestricted, substantiating our earlier conclusion based on the RAPD (random amplified polymorphic DNA) data. The dendrograms obtained using each of these marker systems were poorly correlated with each other as determined by Mantel's test for matrix correlation. Estimates of expected heterozygosity and marker index for each of these marker systems suggests that both these marker systems are equally efficient in determining polymorphisms. Matrix correlation analyses suggest that reliable estimates of genetic variation among the S. incertulas pest populations can be obtained by using RAPDs alone or in combination with ISSRs, but ISSRs alone cannot be used for this purpose.

Use of three different marker systems to estimate genetic diversity of Indian elite rice varieties

Genetic diversity among 42 Indian elite rice varieties, which is important for selection of parents for conventional breeding and hybrid program, was evaluated using three different types of DNA markers and parentage analysis. Random amplified polymorphic DNA (RAPD), inter-simple sequence repeat (ISSR) and sequence tagged microsatellite site (STMS) markers resulted in mean heterozygosity values of 0.429, 0.675 and 0.882 over all loci, respectively, and marker index values of 2.21, 4.05 and 5.49, respectively. The three molecular marker systems together provide wider genome coverage and, therefore, would be a better indicator of the genetic relationships among the 42 elite rice cultivars than those revealed using individual molecular markers. A total of 153 bands (91%) were polymorphic out of 168 bands amplified, considering all the markers together. The average genetic similarity coefficient across all the 861 cultivar pairs was 0.70 while the average coefficient of parentage was 0.10. Cluster analysis revealed that there was a very poor correlation (correlation coefficient <0.1) between dendrograms generated using coefficients of parentage and molecular marker generated genetic similarities, which can be attributed to selection pressure, genetic drift, sampling of loci and unknown relationships among supposedly unrelated ancestors.

Marker assisted selection of bacterial blight resistance genes in rice

Bacterial leaf blight caused by Xanthomonas oryzae pv. oryzae is one of the most important diseases affecting rice production in Asia. We were interested in surveying rice genotypes that are popularly used in the Indian breeding program for conferring resistance to bacterial blight, using 11 STMS and 6 STS markers. The basis of selection of these DNA markers was their close linkage to xa5, xa13, and Xa21 genes and their positions on the rice genetic map relative to bacterial blight resistance genes. Eight lines were found to contain the xa5 gene while two lines contained Xa21 gene and none of the lines contained the xa13 gene with the exception of its near-isogenic line. Using the polymorphic markers obtained in the initial survey, marker-assisted selection was performed in the F3 population of a cross between IR-64 and IET-14444 to detect lines containing multiple resistance genes. Of the 59 progeny lines analyzed, eight lines contained both the resistance genes, xa5 and Xa4.

Differential distribution of simple sequence repeats in eukaryotic genome sequences

Complete chromosome/genome sequences available from humans, Drosophila melanogaster, Caenorhabditis elegans, Arabidopsis thaliana, and Saccharomyces cerevisiae were analyzed for the occurrence of mono-, di-, tri-, and tetranucleotide repeats. In all of the genomes studied, dinucleotide repeat stretches tended to be longer than other repeats. Additionally, tetranucleotide repeats in humans and trinucleotide repeats in Drosophila also seemed to be longer. Although the trends for different repeats are similar between different chromosomes within a genome, the density of repeats may vary between different chromosomes of the same species. The abundance or rarity of various di- and trinucleotide repeats in different genomes cannot be explained by nucleotide composition of a sequence or potential of repeated motifs to form alternative DNA structures. This suggests that in addition to nucleotide composition of repeat motifs, characteristic DNA replication/repair/recombination machinery might play an important role in the genesis of repeats. Moreover, analysis of complete genome coding DNA sequences of Drosophila, C. elegans, and yeast indicated that expansions of codon repeats corresponding to small hydrophilic amino acids are tolerated more, while strong selection pressures probably eliminate codon repeats encoding hydrophobic and basic amino acids. The locations and sequences of all of the repeat loci detected in genome sequences and coding DNA sequences are available at http://www.ncl-india.org/ssr and could be useful for further studies.

Use of DNA markers in prediction of hybrid performance and heterosis for a three-line hybrid system in rice

Two Cytoplasmic Male Sterile lines were crossed with fourteen restorer lines of rice widely grown in the western regions of Maharashtra, India, to produce 28 F1 hybrids which were evaluated for eight agronomically important traits, contributing to yield potential, in replicated field trials. The hybrid performance was recorded along with heterosis and heterobeltiosis. All the rice lines under investigation were subjected to marker-based variability analysis. An attempt was made to correlate genetic distance based on specific markers for each trait individually, as well as average genetic distance based on all specific markers, with hybrid performance and heterosis, by regression analysis. Specific markers could cluster the parental lines in different groups and showed significant correlation with hybrid performance. The data also supports the proposition that epistasis is the basis of heterosis. The analysis, however, revealed a lack of significant predictive values for field application.

Complexity in specificities and expression of Helicoverpa armigera gut proteinases explains polyphagous nature of the insect pest

Helicoverpa armigera is a devastating pest of cotton and other important crop plants all over the world. A detailed biochemical investigation of H. armigera gut proteinases is essential for planning effective proteinase inhibitor (PI)-based strategies to counter the insect infestation. In this study, we report the complexity of gut proteinase composition of H. armigera fed on four different host plants, viz. chickpea, pigeonpea, cotton and okra, and during larval development. H. armigera fed on chickpea showed more than 2.5- to 3-fold proteinase activity than those fed on the other host plants. H. armigera gut proteinase composition revealed the predominance of serine proteinase activity; however, the larvae fed on pigeonpea revealed the presence of metalloproteases and low levels of aspartic and cysteine proteases as well. Gut proteinase activity increased during larval development with the highest activity seen in the fifth instar larvae which, however, declined sharply in the sixth instar. Over 90% of the gut proteinase activity of the fifth instar larvae was of the serine proteinase type, however, the second instar larvae showed the presence of proteinases of other mechanistic classes like metalloproteases, aspartic and cysteine proteases along with serine proteinase activity as evident by inhibition studies. Analysis of fecal matter of larvae showed significant increase in proteinase activity when fed on an artificial diet with or without non-host PIs than larvae fed on a natural diet. The diversity in the proteinase activity observed in H. armigera gut and the flexibility in their expression during developmental stages and depending upon the diet provides a base for selection of proper PIs for insect resistance in transgenic crop plants.

Genetic variation in Indian populations of Scirpophaga incertulas as revealed by RAPD-PCR analysis

Scirpophaga incertulas, commonly referred to as yellow stem borer, is a predominant pest of rice causing serious losses in its yield. Genetic variation among populations of Scirpophaga incertulas collected from 28 hotspot locations in India was examined using the randomly amplified polymorphic DNA-polymerase chain reaction (RAPD-PCR). In all, 32 primers were used and 354 amplification products were observed. No RAPD-PCR bands diagnostic to the pest population from any specific region were identified. Cluster analysis using UPGMA showed that, with the exception of the pest population from Pattambi, all the populations cluster as one group with GD values in the range of 6-22%, suggesting that gene flow between populations is independent of geographic distance and appears to be unrestricted. The relatively high GD value of 48% exhibited by the pest population from Pattambi was the only exception.

Ty1-copia retrotransposon-like elements in chickpea genome: their identification, distribution and use for diversity analysis

Ty1-copia retrotransposon-like elements were amplified from Cicer species using primers derived from the conserved region of the reverse transcriptase gene. Two fragments, of size approximately 280bp and approximately 650 bp, were obtained, which on sequencing showed homology for the Ty1-copia reverse transcriptase region. Interestingly, the approximately 650 bp fragment showed two reverse transcriptase regions, one from Ty1-copia and the other from Tto1 element fused together. The copy number was high in the cultivated Cicer arietinum genome compared with the wild Cicer reticulatum. Genetic diversity among the Cicer species was investigated using the conserved primers which grouped the wild species and the cultivated C. arietinum separately.

TRES: comparative promoter sequence analysis

Comparative promoter analysis is a promising strategy for elucidation of common regulatory modules conserved in evolutionarily related sequences or in genes showing common expression profiles. To facilitate such analysis, we have developed a software tool that detects conserved transcription factor binding sites, cis-elements, palindromes and k-tuples simultaneously in a set of sequences, and thus helps to identify putative motifs for designing further experiments.

Amino acid repeat patterns in protein sequences: their diversity and structural-functional implications

All the protein sequences from SWISS-PROT database were analyzed for occurrence of single amino acid repeats, tandem oligo-peptide repeats, and periodically conserved amino acids. Single amino acid repeats of glutamine, serine, glutamic acid, glycine, and alanine seem to be tolerated to a considerable extent in many proteins. Tandem oligo-peptide repeats of different types with varying levels of conservation were detected in several proteins and found to be conspicuous, particularly in structural and cell surface proteins. It appears that repeated sequence patterns may be a mechanism that provides regular arrays of spatial and functional groups, useful for structural packing or for one to one interactions with target molecules. To facilitate further explorations, a database of Tandem Repeats in Protein Sequences (TRIPS) has been developed and is available at URL: http://www.ncl-india.org/trips.

Pearl millet cysteine protease inhibitor. Evidence for the presence of two distinct sites responsible for anti-fungal and anti-feedent activities

Recently, pearl millet cysteine protease inhibitor (CPI) was, for the first time, shown to possess anti-fungal activity in addition to its anti-feedent (protease inhibitory) activity [Joshi, B.N. et al. (1998) Biochem. Biophys. Res. Commun. 246, 382-387]. Characterization of CPI revealed that it has a reversible mode of action for protease inhibition. The CD spectrum exhibited a 35% alpha helix and 65% random coil structure. The intrinsic fluorescence spectrum was typical of a protein devoid of tryptophan residues. Demetallation of Zn2+ resulted in a substantial change in the secondary and tertiary structure of CPI accompanied by the complete loss of anti-fungal and inhibitory activity indicating that Zn2+ plays an important role in maintaining both structural integrity and biological function. The differential response of anti-fungal and inhibitory activities to specific modifiers showed that there are two different reactive sites associated with anti-fungal and anti-feedent activity in CPI located on a single protein as revealed from its N-terminal sequence data (AGVCYGVLGNNLP). Modification of cysteine, glutamic/aspartic acid or argnine resulted in abolition of the anti-fungal activity of CPI, whereas modification of arginine led to an enhancement of the inhibitory activity in solution. Modification of histidine resulted in a twofold increase in the protease inhibitory activity without affecting the anti-fungal activity, whereas modification of serine led to selective inhibition of the protease inhibitory activity. The differential nature of the two activities was further supported by differences in the temperature stabilities of the anti-fungal (60 degrees C) and inhibitory (40 degrees C) activities. Binding of papain to CPI did not abolish the anti-fungal activity of CPI, supporting the presence of two active sites on CPI. The differential behavior of CPI towards anti-fungal and anti-feedent activity cannot be attributed to changes in conformation, as assessed by their CD and fluorescence spectra. The interaction of CPI modified for arginine or histidine with papain resulted in an enhancement of CPI activity accompanied by a slight decrease in fluorescence intensity of 15-20% at 343 nm. In contrast, modification of serine resulted in inhibition of CPI activity with a concomitant increase of 20% in the fluorescence intensity when complexed by the enzyme. This implies the involvement of enzyme-based tryptophan in the formation of a biologically active enzyme-inhibitor complex. The presence of anti-fungal and anti-feedent activity on a single protein, as evidenced in pearl millet CPI, opens up a new possibility of raising a transgenic plant resistant to pathogens, as well as pests, by transfer of a single CPI gene.

Diversity in inhibitors of trypsin and Helicoverpa armigera gut proteinases in chickpea (Cicer arietinum) and its wild relatives

Developing seeds of eight chickpea (Cicer arietinum L.) cultivars (12-60 days after flowering) showed a significant variation in the trypsin inhibitor (TI) and the Helicoverpa armigera gut proteinase inhibitor (HGPI) content. For example, the highest TI (198 units/g) and HGPI (23 units/g) activities were exhibited by mature seeds of cv ICCV-2, whereas the lowest inhibitor activities were observed in cv PG8505-7 (96.1 TI units/g) and cv Vijay (5 HGPI units/g). Electrophoretic patterns showed a variation in TI bands during the early stages of seed development, indicating cultivar-specific TI accumulation. Among the seed organs, TI and HGPI activities were highly localized in the embryo-axis as compared to the cotyledons in immature and mature seeds. Moisture stress, as effected under rainfed conditions, resulted in reduced PI levels. Wild relatives of chickpea revealed variability in terms of the number and intensity of TI bands. However, when assessed for inhibition of HGP, none of the wild Cicer species showed more than 35% inhibition, suggesting that a large proportion of HGP was insensitive to PIs from Cicer. Our results provide a biochemical basis for the adaptation of H. armigera to the PIs of Cicer species and advocate the need for the transformation of chickpea with a suitable gene(s) for H. armigera resistance.

Expansion of a (GA) dinucleotide at a microsatellite locus associated with domestication in rice

Microsatellites undergo rapid changes over short evolutionary time periods which can be phylogenetically informative in related species. Here we show the repeat unit expansion of a (GA)n-type microsatellite in the process of cultivation of rice from its wild ancestors. We amplified a microsatellite locus harboring (GA)n repeats from several wild and cultivated rices. Sequencing revealed an increase in repeat number from 14 in distantly related wild rice species to 24 in the widely grown present-day indica rice cultivars.

Characterization of Helicoverpa armigera gut proteinases and their interaction with proteinase inhibitors using gel X-ray film contact print technique

Since Helicoverpa armigera is a devastating pest, an attempt was made to separate its gut proteinases and assess their diversity. Gelatin coating present on the X-ray film was used as a substrate to detect electrophoretically separated proteinases of H. armigera gut extract on native polyacrylamide gel electrophoresis (PAGE), sodium dodecyl sulfate (SDS)-PAGE and isoelectric focusing gels. The method involves electrophoresis, followed by washing the gel with Triton X-100 in case of SDS-PAGE, equilibration of the gel in proteinase assay buffers, overlaying the gel on X-ray film followed by washing the film with hot water to remove hydrolyzed gelatin revealing bands of proteinase activity. Using this protocol, at least six different proteinase isoforms were detected in H. armigera gut contents while three isoproteinases were identified in a commercial bacterial proteinase preparation. Adoption of the technique facilitated characterization of the H. armigera gut proteinases (HGP) and provided an easy tool to study the properties of the individual proteinases without purification. The approximate molecular masses of HGP as determined by SDS-PAGE were: 172.9, 59.3, 54.9, 47.6, 44.1 and 41.6 kDa, and of bacterial proteinases: 180.7, 127.3 and 95.3 kDa. The isoelectric point (pI) values of HGP and bacterial proteinase were in the range of 5.1-7.1 and 3.5-7.7, respectively. Some of the HGP isoforms were found to be highly pH-sensitive and showed activity only at pH 10.0. The major HGPs were inhibited by phenylmethylsulfonyl fluoride but not by (4-amidinophenyl)-methanesulfonyl fluoride. Incubation of HGP-resolved electrophoretic gel strips in chickpea or winged bean proteinase inhibitor solution permitted identification of specific inhibitors of individual proteinases and revealed that the major HGPs were insensitive to chickpea inhibitors whereas winged bean inhibitors effectively inhibited all the HGPs. Our results suggest that considerable variability exists among the isoproteinases of H. armigera gut with respect to their pH optima and sensitivity towards chemical and plant proteinase inhibitors. Such diversity is of immense biological significance as it explains the polyphagous nature of the insect which imparts unique adaptability to it against the defensive proteinase inhibitors of its wide range of host plants.

Cysteine protease inhibitor from pearl millet: a new class of antifungal protein

A cysteine protease inhibitor exhibiting antifungal activity from pearl millet seeds has been purified to homogeneity by ammonium sulphate precipitation and chromatographic procedures involving CM- sephadex and SP-sepharose cation exchange columns. The molecular characterization has revealed its molecular mass as 24 kD and isoelectric point 9.8. The amino acid composition data shows presence of high content of serine and glycine (34 residues/mole) and absence of tryptophan. The inhibitor exhibits potent antifungal activity against Trichoderma reesei, a dead wood fungus with minimum inhibitory dose to inhibit mycelial growth or spore germination is as low as 1 microgram/ml (250 ng/disc). In addition to Trichoderma reesei, the antifungal activity is observed against some important phytopathogenic fungi, namely, Claviceps, Helminthosporium, Curvularia, Alternaria and Fusarium species. To the best of our knowledge, a cysteine protease inhibitor as an antifungal protein is reported for the first time from a plant system.

Generalization and exclusive allocation of credit in unsupervised category learning

A new way of measuring generalization in unsupervised learning is presented. The measure is based on an exclusive allocation, or credit assignment, criterion. In a classifier that satisfies the criterion, input patterns are parsed so that the credit for each input feature is assigned exclusively to one of multiple, possibly overlapping, output categories. Such a classifier achieves context-sensitive, global representations of pattern data. Two additional constraints, sequence masking and uncertainty multiplexing, are described; these can be used to refine the measure of generalization. The generalization performance of EXIN networks, winner-take-all competitive learning networks, linear decorrelator networks, and Nigrin's SONNET-2 network are compared.

Genetic fingerprinting of pigeonpea [Cajanus cajan (L.) Millsp.] and its wild relatives using RAPD markers

Randomly amplified polymorphic DNA (RAPD) markers were used for the identification of pigeonpea [Cajanus cajan (L.) Millsp.] cultivars and their related wild species. The use of single primers of arbitrary nucleotide sequence resulted in the selective amplification of DNA fragments that were unique to individual accessions. The level of polymorphism among the wild species was extremely high, while little polymorphism was detected within Cajanus cajan accessions. All of the cultivars and wild species under study could be easily distinguished with the help of different primers, thereby indicating the immense potential of RAPD in the genetic fingerprinting of pigeonpea. On the basis of our data the genetic relationship between pigeonpea cultivars and its wild species could be established.

DNA fingerprinting detects genetic variability in the pearl millet downy mildew pathogen (Sclerospora graminicola)

Genetic variability in six host genotype-specific pathotypes of pearl millet downy mildew pathogen S. graminicola was studied at the molecular level using mini- and micro-satellites. Our results indicated that microsatellites (GAA)6, (GACA)4, and especially (GATA)4 were quite informative and showed high levels of polymorphism among the pathotypes. The six pathotypes could be classified into five groups based on the cluster analysis of their genetic similarities, thereby confirming the existence of distinct host genotype-specific virulence in S. graminicola pathotypes. We demonstrate, for the first time, the use of DNA fingerprinting to detect genetic variation in downy mildew fungus of pearl millet.

DNA fingerprinting to detect genetic variation in rice using hypervariable DNA sequences

The suitability of miniand microsatellite related DNA sequences capable of detecting multiple loci was investigated for their ability to generate DNA fingerprints in rice. These included R18.1, a cattle-derived probe, the M13 repeat probe, pV47, a human minisatellite probe; and repeats in the Per gene, telomere, chi sequence and 3' hypervariable region of apolipoprotein B. With the R18.1, pV47 and M13 repeat probes, the level of polymorphism was high enough to identify all of the cultivars and wild rice species used in this study. R18.1, which showed the highest level of polymorphism, was estimated to identify up to 2.5×10(20) genotypes of rice. In a F2 population of a 'Basmati-370' and 'Taichung-65' cross, loci detected by R18.1 segregated in a Mendelian fashion. DNA fingerprints were somatically stable and the hybridization patterns were identical among different plants of the same cultivar. Application of the above molecular genetic markers for identification of rice genotypes is reported here for the first time.

DNA fingerprinting in rice using oligonucleotide probes specific for simple repetitive DNA sequences

In this report we describe the use of five oligonucleotide probes, namely (GATA)4, (GACA)4, (GGAT)4, (GAA)6 and (CAC)5, to reveal highly polymorphic DNA regions in rice. With each of the oligonucleotide probes, the level of polymorphism was high enough to distinguish several rice genotypes. Moreover, individual plants of one cultivar showed the same cultivar-specific DNA fingerprint. The multilocus fingerprint patterns were somatically stable. Our study demonstrates that microsatellite-derived DNA fingerprints are ideally suited for the identification of rice genotypes. As the majority of the probes detected a high level of polymorphism, they can be very useful in monitoring and aiding gene introgression from wild rice into cultivars.

(CAC)5 detects DNA fingerprints and sequences homologous to gene transcripts in rice

In the present report the potential of (CAC)5 is demonstrated for DNA fingerprinting in rice. Based on the fingerprint data, (CAC)5 was estimated to differentiate up to 6.3 x 10(8) genotypes of rice. In a search for homologous sequences in rice transcripts, four oligonucleotide probes, namely, (CAC)5, (GATA)4, (GACA)4, and (TG)10, were used. Among these probes, (CAC)5 showed hybridization to total rice RNA in a tissue-specific manner; while a band at 1.2 kb was common in both seed and leaf RNA, there were additional prominent bands at 1.9 and 2.3 kb in seed and leaf RNA, respectively. When (CAC)5 was hybridized to poly(A)+ RNA, in addition to a band at 1.2 kb in seed and leaf, hybridization was observed only in seed to heterogeneously sized RNAs.

Studies of operational variables in batch mode for genetically engineered Escherichia coli cells containing penicillin acylase

A recombinant Escherichia coli was constructed by cloning the penicillin acylase gene from E. coli ATCC 11105. The cloning was carried out using a recombinant plasmid pUSAD2 harboring the pac gene. The recombinant E. coli DH 5 cells were used as a biocatalyst and were studied in a batch reactor for determination of optimum value for some of the process parameters, such as effect of pH, temperature, substrate concentration, kLa and effect of carbon and nitrogen source on penicillin acylase production. These values were then compared with the values obtained with the standard parent strain. Whereas the cloned pac gene was found to produce higher levels of penicillin acylase constitutively, the process parameters remained about the same for both the parent and the recombinant.

Predominance and tissue specificity of adenine methylation in rice

Using 'A' and 'C' methylation-specific restriction enzymes, namely, MboI, Sau3AI, DpnI, MspI, and HpaII, total rice cv Basmati 370 DNA, repetitive DNAs, and a specific repeat sequence indicated an abundance of adenine methylation. Although cytosine methylation in 5'-CCGG-3' sequences suggested more CpC methylation than CpG, the 'C' methylation in sequence 5'-GATC-3' was comparatively less than 'A' methylation. Furthermore, the presence of adenine methylation was tissue specific; it was predominant in rice shoot DNA as compared to embryo DNA. This pattern was also observed in two other cultivars of rice, i.e., R-24 and Sona, and was again confirmed using a cloned probe of a specific repeat sequence. Besides the changes in adenine methylation, there was also a qualitative change in 5mC from CpG to CpC dinucleotides in these two tissue systems.

Identification of a dispersed MboI repeat family in five higher plant genomes

Digestion of nuclear DNAs of five plants, namely Cucurbita maxima (red gourd), Trichosanthes anguina (snake gourd), Cucumis sativus (cucumber), Cajanus cajan (pigeon pea) and Phaseolus vulgaris (french bean) with the restriction endonuclease MboI yielded discrete size classes with molecular weights in the range of 0.5 to 5 kbp. The MboI digestion pattern of Cot 0.1 DNA in french bean is comparable with that of total DNA, indicating that these bands represented highly repeated DNA sequences. Cleavage of the DNAs with varying amounts of MboI indicated the dispersed nature of the repeat families. Southern hybridization studies using french bean highly repetitive DNA as a probe indicated more homology with repeats of pigeon pea and less homology with red gourd, snake gourd and cucumber repeats.

Modulation of humoral immune responses by endogenous opioids

The effects of opioid agonists and antagonists were investigated on humoral immune mechanisms in mice and rats. Opioid agonists like morphine, Leu-enkephalin, and Met-enkephalin, enhanced antigen-induced histamine release from mixed peritoneal cells of rats in vitro; this enhancement was effectively antagonized by naloxone, an opioid antagonist. Naloxone, per se, decreased anaphylactic mortality in doses of 10 mg/kg, while it increased mortality in a dose of 1 mg/kg. Reduced IgE antibody titer, measured by passive cutaneous anaphylaxis, decreased hemagglutination titer to sheep red blood cells, blocked histamine release from mixed peritoneal cells of rats in vitro induced by antigen, but had no significant effect when histamine release was induced by compound 48/80. Thus, it appears that endogenous opioids are involved in humoral immune responses.

DNA sequence organization in the genomes of three related millet plant species

A major portion of the genomes of three millet species, namely, barn yard millet, fox tail millet and little millet has been shown to consist of interspersed repeat and single copy DNA sequences. The interspersed repetitive DNA sequences are both short (0.15-1.0 kilo base pairs, 62-64% and long (>1.5 kilo base pairs, 36-38%) in barn yard millet and little millet while in fox tail millet, only long interspersed repeats (>1.5 kilo base pairs) are present. The length of the interspersed single copy DNA sequences varies in the range of 1.6-2.6 kilo base pairs in all the three species. The repetitive duplexes isolated after renaturation of 1.5 kilo base pairs and 20 kilo base pairs long DNA fragments exhibit a high thermal stability with Tms either equal to or greater than the corresponding native DNAs. The S1 nuclease resistant repetitive DNA duplexes also are thermally stable and reveal the presence of only 1-2% sequence divergence.The present data on the modes of sequence arrangement in millets substantiates the proposed trend in plants, namely, plants with 1C nuclear DNA content of less than 5 picograms have diverse patterns of sequence organization while those with 1C nuclear DNA content greater than 5 picograms have predominantly a short period interspersion pattern.

Toxicity of 5-methoxymethyl-2'-deoxyuridine in hamsters and evaluation of its mutagenicity by sister chromatid exchanges and hypoxanthine guanine phosphoribosyl transferase assays

Toxic effects of 5-methoxymethyl-2'-deoxyuridine (MMdUrd), a drug with antiviral activity against herpes simplex virus, were investigated in Chinese golden hamsters. Pathological, hematological, and clinical chemistry parameters were studied. Systemic toxicity was not observed in hamsters after intraperitoneal (ip) administration of MMdUrd in single doses up to 3000 mg/kg and in repeated dosages of 600 mg/kg daily for 15 days. No gross or microscopic lesions related to MMdUrd treatment were observed in the tissues examined from the animals of subchronic toxicity study. Administration of a single dose of 6000 mg/kg of MMdUrd ip caused cloudy swelling, increased mitotic figures, varied nuclear sizes, and scattered coagulation necrosis of hepatocytes on the second day after drug administration. These hepatic lesions were not observed in animals sacrificed on the fourth and sixth days postadministration of MMdUrd. Microscopic examination of marrow smears from control and MMdUrd-treated animals revealed no differences in morphological features of hematopoiesis, nor were significant differences observed between treated and control animals for hematological parameters. Increased concentrations of alanine amino transferase were observed on the first and second day in animals, given a single dose of 6000 mg/kg of MMdUrd. Increases in sister chromatid exchanges and the number of azaguanine-resistant mutants were observed after exposure to a high concentration of MMdUrd (1024 micrograms/ml).