A serine-to-threonine substitution in the triazine herbicide-binding protein in potato cells results in atrazine resistance without impairing productivity

A mutation of the psbA gene was identified in photoautotrophic potato (Solanum tuberosum L. cv Superior x U.S. Department of Agriculture line 66-142) cells selected for resistance to 6-chloro-N-ethyl-N'-(1-methylethyl)-1,3,5-triazine-2,4-diamine (atrazine). Photoaffinity labeling with 6-azido-N-ethyl-N'-(1-methylethyl)-1,3,5-triazine-2,4-diamine detected a thylakoid membrane protein with a M(r) of 32,000 in susceptible, but not in resistant, cells. This protein was identified as the secondary quinone acceptor of photosystem II (QB) protein. Atrazine resistance in selected cells was attributable to a mutation from AGT (serine) to ACT (threonine) in codon 264 of the psbA gene that encodes the QB protein. Although the mutant cells exhibited extreme levels of resistance to atrazine, no concomitant reductions in photosynthetic electron transport or cell growth rates compared to the unselected cells were detected. This is in contrast with the losses in productivity observed in atrazine-resistant mutants that contain a glycine-264 alteration.

Giant hydronephrosis masquerading as massive ascites

A case of unilateral giant hydronephrosis containing about 20 litres of old haemorrhagic fluid, clinically simulating massive ascites, is reported. The role of preceding abdominal trauma in the pathogenesis and the rapidity of the disease process is discussed.

A nucleotide sequence involved in replicative transformation of a filamentous fungus

Replicative plasmids generated through in-vivo recombination have been identified among transformants of the fungus Pleurotus ostreatus. In addition to sequences from a standard selection vector (pAN7-1), these recombinant plasmids contain recombined sequences of chromosomal origin conferring replicative potential upon the vector. One such recombined sequence, an 1148-bp insert into plasmid pP01, has been characterized. This sequence has been analyzed for secondary structural features as well as for consensus sites affiliated with origins of replication (ori) in other eukaryotic systems. The 1148-bp insert lacks an ORF and does not contain an acceptable match to the commonly identified 11-bp ars consensus sequence (A/TTTTATA/GTTTA/T) for autonomous replication in the yeast Saccharomyces cerevisiae. The analysis, however, revealed a cluster of three hairpin-loop-forming subsequences with individual delta G25 degrees C free energy values of -7.6, -6.4 and -5.2 kcal mol-1. Also found were two 7-bp analogues to centromere-affiliated sequences recognized in other fungi, as well as several putative gyrase recognition sites comparable to the 9-bp S. cerevisiae/E. coli gyrase-binding consensus sequence. Sequences comparable to the ori of the yeast 2-microns plasmid or to various sequences associated with ori of yeast/fungal mitochondrial DNAs (mtDNA) were not present in the 1148-bp insert. Replication of pP01 appears rather to involve a replication of chromosomal derivation devoid of an ars-type consensus.

Effects of diet and lifestyle changes on atherosclerotic risk factors after 24 weeks on the Indian Diet Heart Study

In a randomized, single-blind, controlled trial, 621 patients were assigned either intervention diet A (group A, 310 patients) or control diet B (group B, 311 patients) for a period of 24 weeks. After 24 weeks as revealed by dietary questionnaires, group A patients received: (1) a diet with a higher percentage of calories from fruits and vegetables and complex carbohydrates; (2) a higher polyunsaturated/saturated fat ratio diet; and (3) a larger amount of soluble dietary fiber, antioxidant vitamins and minerals and low saturated fat and cholesterol than group B. Group A patients also did more physical and yogic exercises than group B. Adherence to diet and exercise was obtained through questionnaires and information obtained was quantified into a formula. After 24 weeks, the overall score of diet and exercises was significantly higher in group A than in group B. There was a significant decrease in serum total cholesterol (13.3%), low-density lipoprotein cholesterol (16.9%), triglycerides (19.2%), fasting blood glucose (19.5%) and blood pressures (11.5/6.2 mm Hg) in the intervention group compared with initial levels and changes in group B. The effect of exercise on the decrease in risk factors was additive. Within group A, overall score for diet and exercise was greater in 1 subset of 116 patients in the intervention group which had maximal lifestyle changes. A separate analysis of data in this subgroup revealed a greater decrease in risk factors compared with risk factor changes in the remaining 194 patients with less higher overall score; this indicated that the relation of lifestyle changes with reduction in risk factors may be of causal nature.(ABSTRACT TRUNCATED AT 250 WORDS)

Isolation and characterization of wheat triticin cDNA revealing a unique lysine-rich repetitive domain

Polyclonal antibodies were raised against a purified 22 kDa triticin polypeptide (delta) and were used to screen a wheat seed cDNA library in the Escherichia coli expression vector lambda gt11. The isolated cDNA clones were grouped into three families based on their cross-hybridization reactions in DNA dot-blot studies. Southern blots of genomic DNAs extracted from ditelocentric and nullisomic-tetrasomic lines of Chinese Spring wheat, probes with the excised cDNA inserts, indicated that one of the three families (9 clones) had triticin clones. This was finally confirmed by comparing the predicted amino acid sequences of two of these clones (lambda Tri-12, lambda Tri-25) with the published tryptic peptide sequences of triticin. The Southern blots also showed that there is at least one triticin gene located on the short arm of each of the homoeologous group 1 chromosomes (1A, 1B, 1D), although till now no triticin protein product has been identified for the chromosome 1B. The nucleotide sequence of the largest triticin cDNA clone lambda Tri-25 (1567 bp) is presented here, and its predicted amino acid sequence shows strong homology with the legumin-like proteins of oats (12S globulin), rice (glutelin) and legume seeds. A unique feature of the triticin sequence is that it contains a lysine-rich repetitive domain, inserted in the hypervariable region of the typical legumin-like genes. Northern blotting of total RNA extracted from different stages of the developing wheat seed revealed that the triticin gene expression is switched on 5-10 days after anthesis (DAA). There was a steady increase in the level of triticin mRNA until 20 DAA, after which it started decreasing. The maximum mRNA accumulation occurred between 17 and 20 DAA. These observations conform closely with the published data on triticin protein accumulation during grain development.

Can guava fruit intake decrease blood pressure and blood lipids?

A randomized, single-blind, controlled trial was conducted to examine the effects of guava fruit intake on BPs and blood lipids in patients with essential hypertension. Of 145 hypertensives that entered the trial, 72 patients were assigned to take a soluble fibre and a potassium-rich diet containing 0.5-1.0 kg of guava daily (group A) and 73 patients to their usual diet (group B), while salt, fat, cholesterol, caffeine and alcohol intake were similar in both groups. Mean age, mean body weight and male sex, were similar, and so were risk factors, mean BPs, mean serum sodium, potassium, calcium, magnesium, triglycerides, cholesterol and HDL-cholesterol in both groups. Dietary adherence to guava intake was checked by a questionnaire. After four weeks of follow-up on an increased consumption of dietary potassium and low sodium/potassium ratio, group A patients were associated with 7.5/8.5 mmHg net decrease in mean systolic and diastolic pressures compared with group B. Increased intake of soluble dietary fibre (47.8 +/- 11.5 vs. 9.5 +/- 0.85 g/day) was associated with a significant decrease in serum total cholesterol (7.9%), triglycerides (7.0%) and an insignificant increase in HDL-cholesterol (4.6%) with a mild increase in the ratio of total cholesterol/HDL-cholesterol in group A patients compared with group B. It is possible that an increased consumption of guava fruit can cause a substantial reduction in BPs and blood lipids with a lack of decrease in HDL-cholesterol due to its higher potassium and soluble fibre content, respectively.

Osmotin gene expression is posttranscriptionally regulated

Accumulation of both osmotin mRNA and osmotin protein in tissues of tobacco (Nicotiana tabacum L. var Wisconsin 38) is subject to complex developmental control. Osmotin was found to be most abundant in tobacco roots and in tissues of the outer stem comprised primarily of epidermis, and it was less abundant in the corolla. It was a minor protein in other tissues and was undetectable in some tissues, including those of developing and mature seeds. The mRNA abundances did not always reflect the amount of protein accumulation because in some tissues high levels of mRNA but not protein were measured and vice versa. Accumulation of osmotin mRNA but not protein occurred in some plant tissues due to treatment with abscisic acid, wounding, and tobacco mosaic virus infection. Ethylene induced the accumulation of osmotin mRNA and, to a small extent, protein in seedlings, but was ineffective with cultured cells. Exposure of cultured cells and plants to NaCl caused high levels of both mRNA and the protein to accumulate. Thus, the accumulation of osmotin mRNA is controlled developmentally and by at least five hormonal or environmental signals. However, posttranscriptional processes can limit osmotin accumulation.

Ultrasonographic patterns of hepatobiliary mass lesions

The study deals with an analysis of ultrasonographic (USG) patterns in 100 consecutive patients with hepatobiliary mass lesions. Amoebic liver abscess, carcinoma (CA) gall bladder and secondaries in liver comprised nearly 70% of cases. USG appearances in liver abscess, hepatoma, secondaries in liver and CA gall bladder were variable, but were characteristic in hydatid disease and congenital polycystic disease. Two patients with cholangiocarcinoma revealed dilated biliary channels with an intraluminal mass in common bile duct.

Analysis of structure and transcriptional activation of an osmotin gene

A Nicotiana tabacum gene encoding the basic PR-like protein osmotin was isolated and characterized. The gene is derived from the N. sylvestris parent of N. tabacum. In cell suspension cultures of tobacco, the osmotin gene was shown to be transcriptionally activated by treatment with ABA. Transcriptional activation of the osmotin promoter was further investigated in transformed plants carrying copies of a fusion of the cloned promoter to the beta-glucuronidase reporter gene. In these plants, the osmotin promoter is transcriptionally activated by the hormones ABA and ethylene. The sensitivity of the osmotin promoter to ABA applied exogenously decreased with age in both roots and shoots of young seedlings. NaCl shock also activated the promoter in plant tissues. The osmotin promoter is much more active in root tissues than in shoot tissues.

Efficacy of low-dose cytarabine therapy in myelodysplastic syndromes

The efficacy of low-dose cytarabine given as 10 mg sub-cutaneously 12 hourly for 2 weeks and repeated at 2 to 3 weekly intervals was evaluated prospectively in 15 consecutive patients of myelodysplastic syndrome over a 3 year period. Response to therapy was assessed clinically and by haematological parameters including bone marrow examination. No patient achieved complete remission. Three patients responded partially. Four patients transformed into acute myelogenous leukaemia. Overall, the results of therapy were disappointing as all the 15 patients died within 6 months of diagnosis.

Recovery of recombinant plasmids from Pleurotus ostreatus transformants

A transformation system employing selectable resistance to hygromycin B has been developed for the mushroom-forming fungus, Pleurotus ostreatus. Vector pAN7-1, a commonly used non-replicative vector for integrative transformation in fungi, yielded 5-46 resistant colonies per micrograms of DNA per 10(7) viable protoplasts. Southern blot analysis of certain transformants revealed unexpected replicative plasmids containing pAN7-1 sequences, but modified for size, methylation and restriction enzyme pattern when compared to the initial transforming vector. Two such replicative derivatives of pAN7-1 have been rescued from P. ostreatus by cloning into Escherichia coli. Rescued plasmids have been used to probe DNA from untransformed P. ostreatus in an effort to identify fungal sequences that recombined in vivo with pAN7-1 to form replicative plasmids. Such replicative sequences have been localized in high molecular weight (chromosomal) DNA of wild-type P. ostreatus. Transformation has been obtained for P. ostreatus using a rescued plasmid, thereby confirming the role of this recombinant plasmid as a shuttle vector.

Expression of Osmotin-Like Genes in the Halophyte Atriplex nummularia L

A peptide (molecular mass 50 kilodaltons) that is immunologically related to tobacco osmotin was detected in cells of the halophyte Atriplex nummularia. This protein was constitutively expressed in both unadapted and NaCl-adapted cells. A predominant osmotin-like peptide (molecular mass 24 kilodaltons) was also found in culture media after cell growth. Two unique A. nummularia cDNA clones, pA8 and pA9, encoding osmotin-like proteins have been isolated. The pA8 and pA9 inserts are 952 and 792 base pairs and encode peptides of 222 and 224 amino acids, respectively. The peptide deduced from pA8 has a molecular mass of 23,808 daltons and theoretical isoelectric point of 8.31, whereas the peptide derived from pA9 has a molecular mass of 23,827 daltons and an isoelectric point of 6.88. Unique transcripts were detected by the inserts of the cDNA clones, two (1.2 and 1.0 kilobases) by pA8 and one (0.9 kilobase) by pA9. The pA8 transcripts were constitutively accumulated in unadapted and NaCl-adapted cells, whereas the mRNA levels were up-regulated by abscisic acid treatment. The level of pA9 mRNA was induced by NaCl treatment and increased in cells as a function of NaCl adaptation. Southern analysis of the genomic DNA indicated the presence of osmotin-like multigene families in A. nummularia.

Isolation and characterization of an analogue-resistant aminoacyl-tRNA synthetase mutant in Aspergillus nidulans

Six mutants resistant to p-fluorophenylalanine (FPA) were selected on a medium containing aspartate as the sole source of nitrogen using a phenylalanine-requiring (phenA)auxotroph of A. nidulans as the wild type. The mutants, on the basis of genetic characterization, were found to be alleilic and located on the left arm of the linkage group III, approximately 13 map unit left to meth H locus, henceforth assigned to the symbol fpaV. At a fixed concentration of phenylalanine (23 micrograms/ml), the LD50 value of FPA for all the six mutants was found to be about three times more than that for the wild type strain. Affinity chromatographic purification of the enzyme phenylalanyl-tRNA (Phe-tRNA) synthetase from the mutant as well as the wild type strains, revealed that the wild type enzyme had about 1.4-fold higher affinity for phenylalanine as compared to that for FPA, both in the affinity column and in the catalytic reaction. However, the mutant enzyme showed almost a similar affinity for both in columns but a greatly reduced affinity for FPA in the catalytic reaction.

NaCl Regulation of Tonoplast ATPase 70-Kilodalton Subunit mRNA in Tobacco Cells

A cDNA clone encoding the 70-kilodalton subunit of the tobacco (Nicotiana tabacum var Wisconsin 38) tonoplast ATPase has been isolated. The 1.656 kilobase insert contains only open reading frame that represents more than 80% of the carrot cDNA coding region. The deduced amino acid sequence has greater than 95% sequence identity with the homologous carrot sequence. A transcript of approximately 2.7 kilobase was detected on Northern blots of tobacco poly(A)(+) selected or total RNA using labeled probe produced from this clone. The gene was expressed throughout the growth cycle in unadapted and 428 millimolar NaCl adapted cells. Transcription of the 70-kilodalton subunit gene or mRNA stability was induced by short-term NaCl treatment in NaCl adapted cells or by abscisic acid treatment in both adapted and unadapted cells. Southern analysis indicated the presence of up to four genes encoding the 70-kilodalton subunit.

Lymphatic leishmaniasis associated with visceral leishmaniasis

Lymphatic leishmaniasis associated with visceral leishmaniasis is rare in India. We are reporting one such case, which is the first case reported so far from Bihar.

Cytosolic L-alanine:4,5-dioxovalerate transaminase differs from the mitochondrial form

L-Alanine:4,5-dioxovalerate transaminase was detected in the kidney cytosolic fraction with a lower specific activity than the mitochondrial enzyme. The enzyme was purified from the cytosol to homogeneity with a yield of 32%, and comparative analysis with the mitochondrial form was performed. Both forms of the enzyme have identical pH and temperature optima and also share common antigenic determinants. However, differences in their molecular properties exist. The molecular mass of the native cytoplasmic enzyme is 260 kDa, whereas that of the mitochondrial enzyme is 210 kDa. In addition, the cytoplasmic L-alanine: 4,5-dioxovalerate transaminase had a homopolymeric subunit molecular mass of 67 kDa compared to a subunit molecular mass of 50 kDa for the mitochondrial L-alanine:4,5-dioxovalerate transaminase. This is the first report of two forms of L-alanine:4,5-dioxovalerate transaminase. The different responses of cytosolic and mitochondrial L-alanine:4,5-dioxovalerate transaminases to hemin supplementation both in vitro and in vivo was demonstrated. Maximum inhibition of mitochondrial L-alanine:4,5-dioxovalerate transaminase activity was demonstrated with hemin injected at a dose of 1.2 mg/kg body mass, whereas the same dose of hemin stimulated the cytosolic enzyme to 150% of the control. A one-dimensional peptide map of partially digested cytosolic and mitochondrial L-alanine:4,5-dioxovalerate transaminase shows that the two forms of the enzymes are structurally related. Partial digestion of the cytosolic form of the enzyme with papain generated a fragment of 50 kDa which was identical to that of the undigested mitochondrial form (50 kDa). Moreover, papain digestion resulted in a threefold increase in cytosolic enzyme activity over the native enzyme, and such enhancement was comparable to the activity of the mitochondrial form of the enzyme. Therefore, we conclude that the cytosolic form of L-alanine: 4,5-dioxovalerate transaminase is different from the mitochondrial enzyme. Furthermore, immunoblot analysis indicated that the mitochondrial enzyme has antigenic similarity to the cytosolic enzyme as well as to the papain-digested cytosolic enzyme 50-kDa fragment.

Changing response to diamidine compounds in cases of kala-azar unresponsive to antimonial

Two hundred and forty patients of kala-azar unresponsive to antimonial were treated with pentamidines in a dose of 4 mg/kg body weight on alternate days for 20 injections. Of these, 175 were treated with pentamidine isethionate and 65 with pentamidine methane sulphonate (Lomidine). Clinical and parasitological cure were significantly higher with lomidine as compared to pentamidine isethionate. However, cardiovascular, gastrointestinal and metabolic toxicity including hyperglycaemia were more marked with lomidine. Mortality rate was also significantly (P less than .05) higher with lomidine therapy. Significantly lower clinical and parasitological cure and higher relapse rate were observed in the present study compared with an earlier study in which pentamidine was used in the same doses for 10-12 injections only.

Linkage mapping of genes for resistance to leaf, stem and stripe rusts and ω-secalins on the short arm of rye chromosome 1R

The genes controlling resistance to three wheat rusts, viz., leaf rust (Lr26), stem rust (Sr31) and stripe or yellow rust (Yr9), and ω-secalins (Sec1), located on the short arm of rye chromosome 1R, were mapped with respect to each other and the centromere. Analysis of 214 seeds (or families derived from them) from testcrosses between a 1BL.1RS/1R heterozygote and 'Chinese Spring' ditelocentric 1BL showed no recombination between the genes for resistance to the three rusts, suggesting very tight linkage or perhaps a single complex locus conferring resistance to the three rusts. The rust resistance genes were located 5.4 ± 1.7 cM from the Sec1 locus, which in turn was located 26.1 ± 4.3 cM from the centromere; the gene order being centromere - Sec1 - Lr26/Sr31/Yr9 - telomere. In a second test-cross, using a different 1BL.1RS translocation which had only stem rust resistance (SrR), the above gene order was confirmed despite a very large proportion of aneuploids (45.8%) among the progeny. Furthermore, a map distance of 16.0 ± 4.8 cM was estimated for SrR and the telomeric heterochromatin (C-band) on 1RS. These results suggest that a very small segment of 1RS chromatin is required to maintain resistance to all three wheat rusts. It should be possible but difficult to separate the rust resistance genes from the secalin gene(s), which are thought to contribute to dough stickiness of wheat-rye translocation lines carrying 1RS.

Isolation and Partial Characterization of a Seed Lectin from Tepary Bean that Delays Bruchid Beetle Development

Four isolectin forms of a seed lectin from mature seed of tepary bean (Phaseolus acutifolius) were isolated using solubility fractionation, affinity chromatography, and high performance liquid chromatography. The subunits are polypeptides with an apparent molecular mass of 30,000 daltons. The 30 kilodalton subunits are produced starting approximately 13 days after flowering and subsequently comprise a major fraction of the proteins found in the mature seed. The amino terminus of each isolectin fraction was determined to be highly homologous with that of the subunits of common bean (Phaseolus vulgaris L.) phytohemagglutinin (PHA). The tepary isolectin cross-reacts with both erythroagglutinating and leucoagglutinating subunits of PHA antibodies, although differential cross-reactivity was noted. A seed protein fraction enriched in tepary bean lectin was found to be toxic to bean bruchid beetles (Acanthoscelides obtectus), when incorporated into their diets at incremental concentrations from (1-5% w/w) above that of PHA concentrations in mature seeds of the susceptible common bean variety "Red Kidney."

Efficacy of enalapril in essential hypertension and its comparison with atenolol

The effect of enalapril was evaluated in 67 patients with essential hypertension, and its therapeutic efficacy was compared with atenolol in a placebo run-in, single-blind, cross-over trial. Enalapril significantly reduced blood pressure in all grades of essential hypertension. As monotherapy it 'normalized' blood pressure in 88%, 50% and 25% of patients with mild, moderate and severe hypertension respectively. Optimal dose for most of the patients was 20 to 40 mg/day. Comparison with atenolol revealed almost parallel efficacy of the two drugs, although enalapril produced a significantly greater reduction in systolic blood pressure in patients with mild and moderate hypertension (P less than 0.01 in each group). No serious side effects were encountered with either drug. Enalapril, therefore, has a potent and slightly superior antihypertensive effect to that of atenolol, and may be used as a 'first-step' drug in the treatment of hypertensive patients.

Stable NaCl Tolerance of Tobacco Cells Is Associated with Enhanced Accumulation of Osmotin

Osmotin is a major protein which accumulates in tobacco cells (Nicotiana tabacum L. var Wisconsin 38) adapted to low water potentials. Quantitation of osmotin levels by immunoblots indicated that cells adapted to 428 millimolar NaCl contained 4 to 30 times the level of osmotin found in unadapted cells, depending on the stage of growth. Unadapted cells accumulated low levels of osmotin with apparent isoelectric points, (pl) of 7.8 and >8.2. Upon transfer of NaCl-adapted cells to medium without NaCl and subsequent growth for many cell generations, the amount of osmotin declined gradually to a level intermediate between that found in adapted and unadapted cells. NaCl-adapted cells grown in the absence of NaCl accumulated both pl forms; however, the form accumulated by cells adapted to NaCl (pl > 8.2) was most abundant. Adapted cells grown in the absence of NaCl exhibited absolute growth rates and NaCl tolerance levels which were intermediate to those of NaCl-adapted and unadapted cells. The association between osmotin accumulation and stable NaCl tolerance indicates that cells with a stable genetic change affecting the accumulation of osmotin are selected during prolonged exposure to high levels of NaCl. This stable alteration in gene expression probably affects salt tolerance.

Kala-azar mortality in hospitalized cases in north Bihar, India

The mortality in kala-azar was studied in 261 cases admitted in SKMCH during the years 1983-1987. 23 deaths (8.81%) were observed; 9 (39.1%) died due to complications of the disease, while 14 (60.9%) died of toxicity of Sodium Stibogluconate or Pentamidine.