Combination of all-stage and high-temperature adult-plant resistance QTL confers high-level, durable resistance to stripe rust in winter wheat cultivar Madsen.

KEY MESSAGE: Wheat cultivar Madsen has a new gene on the short arm of chromosome 1A and two QTL for all-stage resistance and three QTL for high-temperature adult-plant resistance that in combination confer high-level, durable resistance to stripe rust. Wheat cultivar Madsen has maintained a high-level resistance to stripe rust over 30 years. To map quantitative trait loci (QTL) underlying the high-level, durable resistance, 156 recombinant inbred lines (RILs) developed from cross Avocet S × Madsen were phenotyped with selected races of Puccinia striiformis f. sp. tritici in the greenhouse seedling tests, and in naturally infected fields during 2015-2017. The RILs were genotyped by SSR and SNP markers from genotyping by sequencing and the 90 K wheat SNP chip. Three QTL for all-stage resistance were mapped on chromosomes 1AS, 1BS and 2AS, and two QTL for high-temperature adult-plant (HTAP) resistance were mapped on 3BS and 6BS. The most effective QTL on 2AS, explaining 8.97-23.10% of the phenotypic variation in seedling tests and 8.60-71.23% in field tests, contained Yr17 for all-stage resistance and an additional gene for HTAP resistance. The 6BS QTL, detected in all field tests, was identified as Yr78. The 1AS QTL, conferring all-stage resistance, was identified as a new gene, which explained 20.45 and 30.23% of variation in resistance to races PSTv-37 and PSTv-40, respectively, and contributed significantly to field resistance at Pullman in 2015-2017, but was not detected at Mount Vernon. The interactions among QTL were mostly additive, and RILs with all five QTL had the highest level of resistance in the field, similar to Madsen. Genotyping 148 US Pacific Northwest wheat cultivars with markers for the 1AS, 2AS and 6BS QTL validated the genes and markers, and indicated their usefulness for marker-assisted selection.

Molecular Mapping of YrSP and Its Relationship with Other Genes for Stripe Rust Resistance in Wheat Chromosome 2BL.

Stripe rust, caused by Puccinia striiformis f. sp. tritici, is an important disease of wheat worldwide. Resistance is the best way to control the disease. YrSP, a gene originally from 'Spaldings Prolific' wheat and providing resistance to a broad spectrum of races, is used for differentiating P. striiformis f. sp. tritici races but its chromosomal location is not clear. To map YrSP, a near-isogenic line (AvSYrSPNIL) was backcrossed to the recurrent parent, Avocet S. Genetic analysis of the BC7F1, BC8, BC7F2, and BC7F3 progenies confirmed a single dominant gene for resistance. In total, 182 BC7F2 plants and their derived BC7F3 lines were phenotyped with an avirulent P. striiformis f. sp. tritici race and genotyped with simple-sequence repeat (SSR), single-nucleotide polymorphism (SNP), and sequence-tagged site (STS) markers. A linkage map was constructed with 3 SSR, 17 SNP, and 3 STS markers covering 23.3 centimorgans (cM). Markers IWA638 and dp269 were 0.6 cM proximal and 1.5 cM distal, respectively, to YrSP. The gene was mapped in chromosome bin 2BL-C-0.5, physically within the proximal 50% of the chromosome 2BL arm. Allelism tests based on F2 phenotypes indicated that YrSP is closely linked to but not allelic with genes Yr5, Yr7, Yr43, Yr44, and Yr53. Infection type data from tests with 10 historical and currently predominant P. striiformis f. sp. tritici races in the United States also demonstrated differences in specificity between YrSP and the other genes. The specificity of YrSP is useful in differentiating P. striiformis f. sp. tritici races and studying the plant-pathogen interactions, and the information of chromosomal location of the gene and its tightly linked markers should be useful in developing resistant cultivars when combined with other genes for resistance to stripe rust.

Treatment of urinary tract infection with gentamicin once or three times daily.

AIM: To examine the safety and efficacy of once-daily (OD) gentamicin treatment compared with conventional 8-hourly dosing (TDS) for urinary tract infection (UTI). METHODS: This was a prospective, randomized, controlled trial of children 1 mo to 13 y of age with presumed UTI. Children were randomly assigned to OD gentamicin 5 mg kg(-1) d(-1) or TDS gentamicin 6 mg kg(-1) d(-1) divided 8 hourly. Microbiological efficacy, nephrotoxicity, ototoxicity and renal scarring were assessed at the end of treatment. RESULTS: 210 patients with presumed UTI were recruited, of whom 172 were analysable (OD 84, TDS 88). The median age was 7 mo, 50% were male and 74% (n = 127) of patients had pyelonephritis. The majority of infections were due to Escherichia coli (n = 153, 89%), of which 9 (5.2%) were bacteraemic. Comparing the two groups, there was no significant difference in age, gender, duration of fever before admission, pyuria, nitrite positivity or initial total white blood cell count. All patients had negative urine cultures after 2-3 d of treatment, demonstrating 100% microbiological efficacy. There was no difference between the two groups in terms of ototoxicity, nephrotoxicity, duration of gentamicin treatment or time to fever defervescence. CONCLUSION: OD gentamicin is as efficacious as TDS gentamicin in the treatment of UTI in children, with no difference in ototoxicity and nephrotoxicity.

Efficacy and safety of oral desmopressin in the treatment of primary nocturnal enuresis in Asian children.

OBJECTIVE: To determine the efficacy and safety of oral desmopressin (DDAVP) treatment in Asian children with nocturnal enuresis. METHODOLOGY: This was a multicentre randomized placebo-controlled double-blind cross-over study. Patients were randomized to either active treatment with oral 400 mg DDAVP or placebo, with a 2-week medication-free period between the cross-over. Children with primary monosymptomatic nocturnal enuresis, aged between 7 and 18 years, with a minimum frequency of wetting of 6 nights or more during a 2-week observation period were recruited. Efficacy was measured by reduction in the average number of wet nights per week. RESULTS: Of the 37 children initially recruited, the outcomes for 34 children were included in the final cross-over analysis, as they had complete data for both the treatment periods. Statistical analysis by ANOVA showed that there was no significant difference between the medication-free period and the pretreatment period. However, the average number of wet nights per week for the DDAVP treatment period (2.5+/-2.7) was significantly lower than that of the placebo treatment period (4.5+/-2.1) (P < 0.0001). In terms of the safety profile, there was no significant change in bodyweight, blood pressure, serum sodium, serum osmolality, and urine osmolality following DDAVP treatment. CONCLUSION: Oral DDAVP is a safe and efficacious drug for the short-term treatment of children with primary nocturnal enuresis.

Efficacy and safety of one year of growth hormone therapy in steroid-dependent nephrotic syndrome.

OBJECTIVES: To study the efficacy and safety of 1 year of growth hormone (GH) therapy in children with steroid-dependent nephrotic syndrome. STUDY DESIGN: A prospective pilot, open study in which GH (mean dose 0.32 mg/kg per week) was administered for 1 year to 8 children with steroid-dependent nephrotic syndrome requiring prednisolone (mean dose 0.46 mg/kg per day) to maintain remission. Steroid dependence was defined as recurrence of proteinuria within 2 weeks of discontinuation of prednisolone, or when the dose was lowered below a critical level. At entry, all patients had been steroid dependent for at least 1 year. Anthropometric and bone mineral density measurements after treatment were compared with 1-year pretreatment data. RESULTS: Pretreatment mean (+/-SD) chronologic age was 12.6 (+/-3.1) years, with a mean bone age of 9.1 (+/-2.0) years, with delayed puberty in five patients. The mean height velocity increased from 3.7 (+/-1.4) to 9.4 (+/-2.1) cm/yr after 1 year of treatment (p < 0.05). The mean height standard deviation score increased from -1.4 (+/-1.6) to -0.3 (+/-1.1), (p < 0.05). In the spine, the mean bone mineral density increased from 0.50 to 0.64 gm/cm2 (p < 0.05), and in the femoral neck, from 0.55 to 0.64 gm/cm2 (p < 0.05) after 1 year of treatment. Mean lean body mass increased from 58.1% to 62.6% (p < 0.01). There were no significant changes in creatinine clearance, fasting glucose, fasting insulin, or glycosylated hemoglobin levels. The mean bone age increased to 11.4 (+/-2.4) years, and pubertal stage advanced in 2 patients. CONCLUSIONS: One year of GH therapy is effective in improving the height standard deviation score, height velocity, bone mineral density, and lean body mass of children with steroid-dependent nephrotic syndrome. There were no significant adverse effects. However, the bone age accelerated at a greater pace than the height age, and further studies are required to define the role of GH therapy in steroid-dependent nephrotic syndrome.

Primary monosymptomatic nocturnal enuresis in Singapore--parental perspectives in an Asian community.

Primary monosymptomatic nocturnal enuresis (PMNE) is often not openly discussed in Asian societies. We report the parental view of PMNE in Singapore, its impact on patients and their families and the traditional beliefs and its influence on subsequent management. A screening questionnaire was used in evaluating 30 children enrolled in a clinical trial on the use of oral Desmopressin for the treatment of PMNE. Primary monosymptomatic nocturnal enuresis was familial in 56.7% of patients. Fifty per cent of them were previously unevaluated. Earlier remedial attempts included bedtime fluid restriction and voiding (100%), incentive measures (43.3%), traditional practices (26.7%), punishment (20%), drugs (16.7%), psychotherapy (100%) and bladder training (3.3%). Perceived causes of PMNE were maturational delay (50%), deep sleep (50%), familial (43.3%), behavioural problems (43.3%) and excessive fluid intake (26.7%). Reasons for seeking treatment included restricted outdoor activities (90%), parental fatigue (86.7%), disrupted sleep for the household (46.7%) and fear of underlying pathology (26.7%). Perceived adverse effects on patients included social stigma (83.3%), disrupted sleep (33.3%) and impaired school performance (13.3%). Primary monosymptomatic nocturnal enuresis can thus be a chronic distressing problem in Asian communities.

Children hospitalized for varicella: a prevaccine review.

OBJECTIVES: To describe varicella complications in healthy and previously ill children hospitalized for varicella and to explore trends in group A beta-hemolytic streptococcus complications of varicella. METHODS: A retrospective record review of children hospitalized for varicella between January 1, 1990, and March 31, 1994, was conducted in nine large acute care hospitals in Los Angeles County, California. RESULTS: We identified 574 children hospitalized for varicella in study hospitals during the 4.25-year study period (estimated risk of hospitalization, approximately 1 in 550 cases of varicella); 53% of the children were healthy before the onset of varicella and 47% were previously ill with underlying cancers or other chronic illnesses. Children were hospitalized for treatment of complications (n = 427, 74%) or for prophylactic antiviral therapy or observation (n = 147, 26%). Systems involved in complications included skin/soft tissue (45%), neurologic (18%), respiratory (14%), gastrointestinal (10%), and hematologic, renal, or hepatic (8% or less). The mean age of children with skin/soft tissue infections was 2.7 years (range < 1 to 16 years) compared with 4.7 years (< 1 to 18 years) for other complications. Children with skin/soft tissue and neurologic complications were more often previously healthy (p < 0.05), whereas those with respiratory complications were more often previously ill (p < 0.001). Hospitalizations for skin/soft tissue infections increased during the study period. The proportion of complications as a result of group A beta-hemolytic streptococcus infection increased from 4.7% before 1993 to 12.2% for the remainder of the study period (p = 0.02). CONCLUSIONS: Prior health status was predictive of the type of complications experienced by children with varicella requiring hospitalization. Our data suggest a recent increase in skin/soft tissue complications of varicella requiring hospitalization and an increase in the proportion of complications related to group A beta-hemolytic streptococcus. Wide-scale vaccine use should reverse this trend and reduce the overall impact of varicella on both healthy and previously ill children.

Phaeochromocytoma--a rare cause of hypertension in an 11-year-old girl.

Severe sustained hypertension occurs in only 0.1% of the paediatric population and only about 2% of these patients will have an underlying endocrine cause. Phaeochromocytoma as a catecholamine-secreting tumour causing severe hypertension is exceedingly rare in children. A high index of suspicion and an awareness of the clinical spectrum are therefore necessary to make the diagnosis. Phaeochromocytomas can have protean manifestations which may be mistaken for a variety of clinical conditions. We highlight the problems encountered in making the diagnosis in an 11-year-old Chinese girl who presented with sustained hypertension, heart failure and transient renal impairment with two normal 24-hour urinary vanillyl mandelic acid (VMA) results before a third produced the diagnosis. We emphasize that total reliance on a single biochemical urinary screening is not acceptable. The measurement of urinary catecholamines or their metabolites increases the sensitivity of diagnosis. We recommend that in situations where biochemical screening is doubtful, appropriate imaging should be undertaken to exclude the diagnosis.

Suppressive effects of methyl methacrylate on the mutagenicity and DNA adduct formation induced by 1-nitropyrene and benzo[a]pyrene.

Methyl methacrylate (MMA) is widely used as a cement in dentistry, orthopaedic surgery and ophthalmology. Studies based on short-term genotoxicity tests have produced conflicting results in the last two decades. In the present study, the effects of MMA on the mutagenicity of 1-nitropyrene (1-NP) and benzo[a]pyrene (B[a]P) were evaluated with the Salmonella typhimurium TA98 strain in the absence and presence of S9 mix. The direct-acting mutagenicity of 1-NP was markedly decreased by MMA in a dose-dependent manner. However, a low inhibitory effect of MMA on the metabolic-acting mutagenicity of B[a]P was observed. MMA did not show mutagenicity within the concentrations of 4.7-37.6 microM either with or without S9 mix. The inhibitory effect of MMA was not due to its cytotoxicity because very low and/or no cytotoxicity of MMA to S. typhimurium TA98 was observed. To confirm the antimutagenicity of MMA against 1-NP and B[a]P, a 32P-postlabelling method was used to determine whether MMA modified DNA adduct formation produced by both compounds in calf thymus DNA. MMA inhibits the formation of 1-NP- and B[a]P-DNA adducts in a dose-dependent manner. The DNA adduct of 1-NP reduced by MMA was greater than that of B[a]P. Thus, we suggested that MMA was possibly acting as an inhibitor of chemical carcinogenesis.

Risk factors for invasive group A streptococcal infections in children with varicella: a case-control study.

OBJECTIVE: To identify characteristic clinical manifestations and potential risk factors for invasive group A streptococcal (GAS) disease in children with varicella. DESIGN AND PARTICIPANTS: A case-control study was conducted in Los Angeles and Orange Counties, CA. Cases were children with varicella who developed invasive GAS disease between January 1 and May 3, 1994 (n = 25). Controls were acquaintance, neighborhood or schoolmate children with uncomplicated varicella during the study period (n = 62). Cases were compared with controls with regard to underlying illness, child care practices, parental home health practices, health care-seeking behaviors, sociodemographic characteristics and clinical characteristics. RESULTS: Controlling for age we found that cases were more likely than controls: (1) to be cared for in the home vs. out-of-home child care (odds ratio (OR), 4.4 (95% confidence interval (95% CI), 1.1 to 17)); (2) to report having asthma (OR, 6.2 (95% CI, 1.2 to 41.0)) and to be taking albuterol (OR, 11.6 ((95% CI, 1.0 to 581)); (3) to be secondary varicella cases within a household (OR, 7.3 (95% CI, 2.2 to 25)); (4) to report fever after Day 2 of varicella; and (5) to have contacted their health care provider later than controls (Day 3.8 rather than Day 1.7, P < 0.001). CONCLUSIONS: To our knowledge this is the first case-control study exploring potential risk factors for invasive GAS disease in children with varicella. Both previously healthy children with varicella and those with underlying medical problems, including asthma, may be at increased risk for GAS complications. Interventions should be targeted to parents and health care providers to increase awareness of early signs and symptoms of invasive GAS disease in children with varicella. Additional studies are needed to confirm the associations suggested by this study between GAS complications of varicella and asthma, in-home child care, secondary vs. primary varicella household cases and delayed contact with medical care providers.

Triple immunosuppression with subsequent prednisolone withdrawal: 6 years' experience in paediatric renal allograft recipients.

Thirty-four children (< or = 15 years of age) with end-stage renal failure received 39 renal allografts between 1985 and 1991 and were treated with cyclosporin A (CyA), azathioprine and low-dose prednisolone (PNL). We aimed to withdraw PNL by 6 months after transplantation. Median duration of follow-up was 2 years 4 months (range 0.1 month to 6 years 4 months). There were no deaths. Crude graft survival for living-related grafts (n = 9) was 100%, although only 1 patient has been followed for > 2 years. For cadaveric grafts (n = 30), 1- and 5-year actuarial graft survivals were 90% and 79% respectively. At 12 months posttransplant, the median (range) glomerular filtration rate for all patients was 63 (19-109) ml/min per 1.73 m2 (n = 25) and at 5 years was 48 (17-64) ml/min per 1.73 m2 (n = 9). Complications observed included rejection episodes which occurred after discontinuation of PNL. Long-term (after 12 months), 28% of patients remain on PNL. Hypertension was present in more than 50% of patients. Severe CyA nephrotoxicity was not seen. Catch-up growth as determined by the change (delta) in mean height standard deviation score (Ht-SDS) was noted at 1 year [delta SDS/year = +0.60; P < 0.001 (n = 18)] and at 2 years [delta SDS/year = +0.27; P < 0.01 (n = 16)] in pre-pubertal patients. The median Ht-SDS at 2 years for pre-pubertal children was -0.71 SD and growth velocity did not improve thereafter.(ABSTRACT TRUNCATED AT 250 WORDS)

Comparison of progression of renal failure in children with hypoplastic-dysplastic kidneys and chronic glomerulonephritis.

A comparative study was made on two groups of children comprising 20 patients with renal hypoplasia/dysplasia in one group and 12 patients with chronic glomerulonephritis (GN) in the other, presenting with chronic renal failure (CRF) in the Department of Paediatrics, Singapore General Hospital and National University Hospital between 1975 and 1989. The age of onset of CRF, the progression of renal failure and the presence of various clinical complications were analysed and compared. The mean age of onset of CRF was earlier in patients with renal hypoplasia/dysplasia (p less than 0.001) but the progression of renal failure in these patients were slower (p less than 0.005). Hypertension occurred more frequently in the chronic GN group (p less than 0.001) while urinary tract infection (UTI) occurred more frequently in the renal hypoplasia/dysplasia group (p less than 0.004). With the early onset of renal failure and slow deterioration of renal function in patients with renal hypoplasia/dysplasia, the provision of good conservative treatment for renal failure is most important in the management of these patients. In the chronic GN patients however, with the rapidity of deterioration of renal function, early preparation for replacement therapy becomes more imminent. However, renal replacement therapy in end-stage renal failure (ESRF) is costly and not readily available, it is more prudent to delay the onset of ESRF by providing effective conservative treatment of renal failure which includes the early recognition and treatment of hypertension in chronic GN and UTI in renal hypoplasia/dysplasia.

Vesicoureteric reflux and renal scarring in children--a local perspective.

This study was undertaken to determine the extent of primary vesicoureteric reflux and renal scarring in patients investigated for urinary tract infection in the Singapore General Hospital between 1983 and 1988. The clinical profile of patients and possible clinical features associated with renal scarring were analysed. These findings serve as a useful guide in the investigation and management of VUR in our population. The incidence of vesicoureteric reflux among patients investigated for documented urinary tract infection was high at 32.9%. The mean age at presentation was 15.2 months. Almost all patients were less than five years-old. A male predominance was noted in affected infants. High grade refluxes of Grade IV or more (International Reflux Study Classification) were found in 45.7/patients and were associated with a higher incidence of recurrent urinary tract infection (p less than 0.05). Thirty-four 99mTc-dimercaptosuccinic acid scans were done and 46.4% of refluxing kidneys showed renal scars. The incidence of renal scarring was significantly higher in patients presenting at an early age (less than 2 years), in high grade reflux and in recurrent urinary tract infection (p less than 0.05; p less than 0.01 and p less than 0.001 respectively). Therefore all children with documented urinary tract infection who are less than five years old and especially male infants should be fully investigated for early detection and treatment of vesicoureteric reflux and renal scars. Kidneys with vesicoureteric reflux at risk of scarring appeared to be those with early presentation, high grade reflux and recurrent urinary tract infection whose management should therefore be vigorous.

A novel proline-rich protein from wheat.

A cDNA (WPRP1) encoding a wheat proline-rich protein has been isolated and sequenced. The amino acid composition shows 45% proline, with high levels of methionine, lysine and glutamic acid. The derived 378 residue amino acid sequence has a highly repetitive structure which is unlike those of other proline-rich proteins. The WPRP1 cDNA clone was used to determine the copy number and chromosomal location of the WPRP1 gene by restriction fragment length polymorphism analysis of wheat inbred lines. Although WPRP1 is encoded by a single-copy gene it is also a representative of a larger family of related sequences. RNA gel blot analysis showed that expression of WPRP1 is highest in rapidly growing tissue which together with its amino acid composition suggests a structural role for the encoded protein.

Perineal eruption as an early sign of Kawasaki disease.

Kawasaki Disease can present as a diagnostic problem at the early stage of the disease. An interesting and distinctive perineal eruption which appeared early in the course of the disease had been reported recently but sporadically in the medical literature. We reported seven patients with Kawasaki Disease who had this perineal eruption. The rash began two to three days after the onset of fever followed by desquamation in all instances by days five to seven. When compared with other signs of Kawasaki Disease, this rash appeared early. In an earlier study done in the department, the diagnosis of Kawasaki Disease was made on an average of nine days after the onset of fever. This has an important implication as early treatment had been shown to decrease the incidence of coronary arteriectasia which is the most important complication of this disease. We believe that this distinctive perineal eruption is a valuable early clinical finding which may facilitate early diagnosis and treatment of Kawasaki Disease and unless one is aware and actively looked for the perineal eruption, this early sign may be completely missed.