Identification and expression of the Pseudomonas syringae pv. aptata hrpZ(Psa) gene which encodes an harpin elicitor.

A sequence homologous to an internal fragment 0.75 kb BstXI of the Pseudomonas syringae pv. syringae hrpZ gene was identified in Pseudomonas syringae pv. aptata NCPPB 2664, the causal agent of bacterial blight in sugar beet, lettuce and other plants. and in E. coli DH10B (pCCP1069) containing the P. syringae pv. aptata hrp gene cluster. PCR with oligonucleotides, based on the hrpZ(Pss) gene and used as primers with the total genomic DNA of P. syringae pv. aptata, amplified a 1 kb fragment that hybridized with the probe in highly stringent conditions. The amplicon was cloned into the pGEM-T plasmid vector, amplified in E. coli DH5alpha and sequenced. The sequence showed 95%, 83% and 61% identity with those of hrpZ(Pss), hrpZ(Psg and hrpZ(Pst) genes encoding the harpins of the P. syringae pv. syringae, glycinea and tomato, respectively. The amplicon was cloned into the pMAL expression system. The expressed protein, fused with maltose-binding protein, was cleaved with a specific protease factor Xa, and purified using affinity chromatography. On the basis of the amino acid sequence and its ability to induce HR in tobacco leaves, it was identified as a P. syringae pv. aptata harpin.

Poisoning with hair-dye containing paraphenylene diamine: ten years experience.

Hair-dye containing paraphenylene diamine (PPD) is widely used and this compound is known to be toxic, when ingested, to several organs including the kidney. In this study, we reviewed 150 cases presenting to Khartoum Teaching Hospital with PPD poisoning over a period of 10 years. The clinical features commonly involved the gastrointestinal tract, skin and eyes. Nearly all the patients had angioneurotic edema and some cases developed flaccid paraplegia or paraperesis. With regards to the renal involvement, we observed that 90 of the 150 study cases (60%) developed acute renal failure (ARF) requiring dialysis. The mean period on dialysis was 15 days (range 1-42 days). All patients recovered normal renal function. In order to exclude permanent glomerular damage following overdose of PPD, 20 patients were subjected to renal biopsy following recovery from ARF. None had evidence of glomerular injury. On the other hand, three patients who had chronic (skin) contact with the dye and one patient who recovered from ARF a year earlier showed evidence of focal segmental glomerulosclerosis on renal biopsy. We conclude that hair-dye containing PPD can cause severe side effects particularly after oral ingestion. Its use should be discouraged and public attention should be drawn in this regard.

Diverse activity of sc-RIP saporin 6 on primary and metastatic melanoma cells in vitro.

The inhibitory effect of saporin 6, a single-chain ribosome-inactivating protein (sc-RIP) purified from the seeds of Saponaria officinalis, on the proliferation of human primary (MeWo, WM 164, SK MEL 28, MEM), cloned (MEM A9, A12, A13) and metastatic (M14) melanoma cells has been tested by protein synthesis and colony formation assays in vitro. Results indicate a marked difference in the sensitivity of primary and metastatic cells to the action of saporin 6, the latter being significantly more affected, both in treated and in pretreated cultures, with a high and specific response evident after 24 h of treatment and progressively increasing up to 72 h of culture with the drug (IC50 = 0.82 microgram/ml). This effect, which was dose-dependent in exponentially growing cells, was partially reversed upon removal of the inhibitor from the culture medium. No inhibitory effect was evident in the MeWo primary cells at the highest saporin 6 concentration used: the p170 glycoprotein-mediated mechanism is not involved in such a resistance pathway.

Enhanced DNA repair in lymphocytes of Down syndrome patients: the influence of zinc nutritional supplementation.

Oral zinc supplementation is able to correct zinc deficiency and some immune defects present in Down's syndrome (DS), while other beneficial effects can be predicted because of the broad spectrum of biochemical pathways and the great variety of enzymes which depend on zinc bio-availability. To test if the maintenance of DNA integrity is also affected by zinc supplementation, DNA damage and repair after gamma-radiation was studied by alkaline elution assay in phytohemagglutinin-stimulated lymphocytes from Down's syndrome children before and after an oral zinc supplementation given for 4 months to correct their immune defects. In comparison with lymphocytes from normal children the DNA damage induction after ionizing radiation in DS lymphocytes both before and after zinc supplementation was normal. On the other hand, the rate of DNA repair in DS was highly and significantly accelerated before zinc treatment. After supplementation with zinc sulfate, the DNA repair rate was consistently slowed down becoming similar to that of control subjects. This is the first demonstration that a nutritional intervention in humans is apparently able to modify the biochemical steps which control the rate of DNA repair.

The aetiology of chronic renal failure in adult Sudanese patients.

One hundred adult Sudanese patients who presented to Soba University Hospital (SUH) with established chronic renal failure (CRF) were studied to determine the aetiology. Thirty-eight had chronic glomerulonephritis, 12 renal calculi, nine diabetic renal disease, seven chronic pyelonephritis, five sequelae of acute renal failure (ARF), four renal vascular disease, three polycystic disease of the kidneys, and two obstructive uropathy. In 20 patients the aetiology was not determined because of late presentation to hospital. The results were compared with those of the developed countries, which differ greatly from Sudan in climate, diet, race, culture and social habits. The main differences were in the prevalence of renal calculi which, although being the second commonest cause of CRF in the Sudan, were rare in European countries. Also, diabetes mellitus was a much commoner cause of CRF in Sudan than Europe. Other aetiological factors were similar.

The effects of sorghum and wheat bran on the colonic functions of healthy Sudanese subjects.

The effects of sorghum and wheat bran were compared and contrasted in a group of healthy Sudanese subjects. Ten medical students were studied while taking their normal diet, a diet of 20 g/day of sorghum bran and a diet of 20 g/day of wheat bran, each for 3 wk. Toward the end of each dietary period the wet stool weight, gut transit time, and frequency of bowel evacuation were estimated. The mean stool weight on normal diet was 136.6 +/- 43.1 g/day, on sorghum bran 173.3 +/- 48.4 g/day, and on wheat bran 219.1 +/- 98.3 g/day. The increase produced by wheat bran was significant, p less than 0.001. Both brans produced a similar number of bowel evacuations. The results suggest that sorghum bran, which is both cheap and readily available in the Sudan, produces a similar number of bowel evacuations to those of wheat bran without significantly affecting stool weight or transit time.

The nephrotic syndrome in the Sudan with special reference to schistosomal nephropathy. A preliminary morphological study.

The morphology of 68 renal biopsies from the Sudan is analysed. Schistosomal infection was more common among the nephrotic patients than in the average population (32% against less than 1%). In the schistosomal group the high incidence of focal sclerosing glomerulonephritis (28%) and of secondary amyloidosis (38%) was remarkable. The history is described of a boy in whom repeated biopsies showed the decrease of glomerular amyloid depositions accompanied by mesangial cell proliferation following treatment for schistosomiasis.