Fine mapping of LrSV2, a race-specific adult plant leaf rust resistance gene on wheat chromosome 3BS

Fine mapping permits the precise positioning of genes within chromosomes, prerequisite for positional cloning that will allow its rational use and the study of the underlying molecular action mechanism. Three leaf rust resistance genes were identified in the durable leaf rust resistant Argentinean wheat variety Sinvalocho MA: the seedling resistance gene Lr3 on distal 6BL and two adult plant resistance genes, LrSV1 and LrSV2, on chromosomes 2DS and 3BS, respectively. To develop a high-resolution genetic map for LrSV2, 10 markers were genotyped on 343 F2 individuals from a cross between Sinvalocho MA and Gama6. The closest co-dominant markers on both sides of the gene (3 microsatellites and 2 STMs) were analyzed on 965 additional F2s from the same cross. Microsatellite marker cfb5010 cosegregated with LrSV2 whereas flanking markers were found at 1 cM distal and at 0.3 cM proximal to the gene. SSR markers designed from the sequences of cv Chinese Spring BAC clones spanning the LrSV2 genetic interval were tested on the recombinants, allowing the identification of microsatellite swm13 at 0.15 cM distal to LrSV2. This delimited an interval of 0.45 cM around the gene flanked by the SSR markers swm13 and gwm533 at the subtelomeric end of chromosome 3BS.

First isolation and characterization of genomic SSR markers for the giant red shrimp Aristaeomorpha foliacea (Risso, 1827)

Fourteen microsatellite markers were isolated from the giant red shrimp Aristaeomorpha foliacea (Risso, 1827) using the FIASCO protocol (fast isolation by AFLP of sequences containing repeats). Polymorphism was assessed in 30 individuals from two localities of the western Mediterranean basin (N = 20 from Sardinia and N = 10 from Sicily); nine loci showed polymorphism with 2 to 19 alleles per locus (average: 8.9). Polymorphic information content ranged from 0.36 to 0.91, and the observed and expected heterozygosities ranged from 0.50 to 0.97 and from 0.47 to 0.93, respectively. Two loci showed significant deviation from Hardy-Weinberg equilibrium, and evidence of linkage disequilibrium was found for only one locus pair. These loci are the first to be characterized in A. foliacea and could be effective tools for the investigation of genetic diversity, population structure, and demographic connectivity, useful information for the management of this important commercial resource.

Genetic analysis of leaf rust resistance genes and associated markers in the durable resistant wheat cultivar Sinvalocho MA

In the cross of the durable leaf rust resistant wheat Sinvalocho MA and the susceptible line Gama6, four specific genes were identified: the seedling resistance gene Lr3, the adult plant resistance (APR) genes LrSV1 and LrSV2 coming from Sinvalocho MA, and the seedling resistance gene LrG6 coming from Gama6. Lr3 was previously mapped on 6BL in the same cross. LrSV1 was mapped on chromosome 2DS where resistance genes Lr22a and Lr22b have been reported. Results from rust reaction have shown that LrSV1 from Sinvalocho is not the same allele as Lr22b and an allelism test with Lr22a showed that they could be alleles or closely linked genes. LrSV1 was mapped in an 8.5-cM interval delimited by markers gwm296 distal and gwm261 proximal. Adult gene LrSV2 was mapped on chromosome 3BS, cosegregating with gwm533 in a 7.2-cM interval encompassed by markers gwm389 and gwm493, where other disease resistance genes are located, such as seedling gene Lr27 for leaf rust, Sr2 for stem rust, QTL Qfhs.ndsu-3BS for resistance to Fusarium gramineum and wheat powdery mildew resistance. The gene LrG6 was mapped on chromosome 2BL, with the closest marker gwm382 at 0.6 cM. Lines carrying LrSV1, LrSV2 and LrG6 tested under field natural infection conditions, showed low disease infection type and severity, suggesting that this kind of resistance can be explained by additive effects of APR and seedling resistance genes. The identification of new sources of resistance from South American land races and old varieties, supported by modern DNA technology, contributes to sustainability of agriculture through plant breeding.

Efficacy of four different moxifloxacin-based triple therapies for first-line H. pylori treatment

Moxifloxacin has been used in the first-line treatment of Helicobacter pylori infection. The optimal dosage and duration have not been assessed.

AIM

To evaluate the effectiveness of moxifloxacin, amoxicillin and esomeprazole in four regimens, in previously untreated patients infected by H. pylori.

METHODS AND PATIENTS

Patients were randomly assigned to: esomeprazole 20 mg b.i.d., amoxicillin 1g b.i.d., and one of each of the four following dosages of moxifloxacin: moxifloxacin 400 mg b.i.d. for 10 days (EAM800x10), moxifloxacin 400 mg b.i.d. for 7 days (EAM800x7), moxifloxacin 400 mg b.i.d. for 5 days (EAM800x5), moxifloxacin 400 mg o.i.d. for 10 days (EAM400x10). Eradication was assessed by the Urea Breath Test (UBT) 2 months following the end of therapy.

RESULTS

Ninety-four, 102, 92 and 105 patients were recruited in EAM800x10, EAM800x7, EAM800x5, and EAM400x10 respectively. The eradication rate was for Intention-To-Treat (ITT) and Per Protocol (PP) analyses: EAM800x10 group ITT: 90.4%, PP: 94.4%; EAM800x7 group ITT: 80.3%, PP: 86.3%; EAM800x5 group ITT: 71.4%, PP: 75.2%; EAM400x10 group ITT: 80.0%, PP 84.8%. A statistically significant difference was reached between EAM800x10 vs. EAM800x7 (ITT and PP: P<0.05), and between EAM800x10 vs. EAM800x5 (ITT and PP: P<0.01) and vs. EAM400x10 (ITT: P<0.05; PP: P<0.04). Thirty patients treated unsuccessfully with EAM800x5 and EAM400x10 were re-treated with EAM800x10 with an eradication rate of 86.7% (ITT) and 92.2% (PP). Nineteen patients with positive UBT after EAM800x10 and EAM800x7 underwent a second-line rifabutin-based therapy with an eradication rate of 84.2% (ITT and PP).

CONCLUSION

A triple therapy with 800 mg of moxifloxacin a day for 10 days is more effective than the same treatment for 5 or 7 days and a treatment with 400mg of moxifloxacin a day for 10 days for the first-line eradication of H. pylori infection. The high cost of moxifloxacin-based treatment however, may limit its wide use as first-line treatment of H. pylori infection.

[Sildenafil and nitric oxide inhalation in neonatal pulmonary hypertension. Three case reports]

INTRODUCTION

Neonatal persistent pulmonary hypertension (NPPH) is characterised by persistently high pulmonary vascular resistance (PVR). Sildenafil has recently been suggested as an alternative to or an associative therapy with inhaled nitric oxide (iNO) to reduce mortality (10-40%) and morbidity (major neurologic disabilities among surviving newborns remains approximately 15-60%). The objective is to report three cases of NPPH treated with sildenafil in association of iNO.

CASE REPORTS

Echocardiography examination of three newborn babies with respiratory distress syndrome and a gestational age between 33 and 39 weeks revealed pulmonary hypertension following early onset sepsis. Synchronized intermittent mandatory ventilation (SIMV) and surfactant therapy had no effect on oxygen saturation (SatO2) and oxygen alveolar-arterial difference (AaDO2). High frequency oscillatory ventilation (HFOV) and iNO therapy proved to be equally ineffective. Oral sildenafil was administered at 2 mg/Kg/6 hs. A gradual but significant improvement in oxygenation was achieved and a reduction in AaDO2 along with oxygenation index (OI) and pulmonary arterial pressure (PAP) was observed in the first 6-10 hrs after administration of sildenafil. The therapy was maintained for 36-48 hrs with total success.

CONCLUSIONS

A beneficial pulmonary vasodilator effect was obtained in treating NPPH with sildenafil where conventional methods had failed. Sildenafil used in association with iNO reduces the duration of treatment, the quantity of iNO normally required and the associated toxic effects. A multicentric, randomized trial could be useful in demonstrating the safety, efficacy, doses and forms of administration of sildenafil.

Reinfection after successful eradication of Helicobacter pylori: a 2-year prospective study in Alaska Natives

BACKGROUND

Limited information exists regarding risk factors for reinfection after cure of Helicobacter pylori infection.

AIM

To determine the 2-year reinfection rate of H. pylori in a cohort of urban Alaska Natives.

METHODS

Participants over 18 years of age undergoing oesophagogastroduodenoscopy had (13)C urea breath test, culture, CLOtest and histology performed. Those diagnosed with H. pylori who tested urea breath test-negative at 8 weeks after treatment were followed prospectively at 4 months, 6 months, 1 year and 2 years. Subjects experiencing H. pylori reinfection as defined by a positive urea breath test were compared with those who did not become reinfected using univariable and multivariable analysis. Risk of reinfection over time was estimated by the Kaplan-Meier method.

RESULTS

Helicobacter pylori reinfection occurred in 14 of 98 subjects successfully treated. The cumulative reinfection rate was 5.1% (95% CI: 0.7%-9.5%) at 4 months, 7.2% (2.0-12.3%) at 6 months, 10.3% (4.2-16.3%) at 1-year and 14.5% (7.5-21.6%) at 2 years. In multivariable analysis, a history of previous peptic ulcer disease or presence of ulcer at time of study oesophagogastroduodenoscopy were the only risk factors associated with reinfection (P = 0.01).

CONCLUSIONS

Based on the findings from our study, subjects with a history of or current peptic ulcer disease should be followed, after successful treatment for H. pylori, with periodic urea breath test to detect reinfection, as reinfection would put them at high risk for ulcer recurrence.

Physical and genetic mapping of amplified fragment length polymorphisms and the leaf rust resistance Lr3 gene on chromosome 6BL of wheat

The Argentinian wheat cultivar Sinvalocho MA carries the Lr3 gene for leaf rust resistance on distal chromosome 6BL. In this cultivar, 33 spontaneous susceptible lines were isolated and cytogenetically characterized by C-banding. The analysis revealed deletions on chromosome 6BL in most lines. One line was nulli-6B, two lines were ditelo 6BS, two, three, and ten lines had long terminal deletions of 40, 30, and 20%, respectively, three lines showed very small terminal deletions, and one line had an intercalary deletion of 11%. Physical mapping of 55 amplified fragment length polymorphism (AFLP) markers detected differences between deletions and led to the division of 6BL into seven bins delimited by deletion breakpoints. The most distal bin, with a length smaller than 5% of 6BL, contained 22 AFLP markers and the Lr3 gene. Polymorphism for nine AFLPs between Sinvalocho MA and the rust leaf susceptible cultivar Gamma 6 was used to construct a linkage map of Lr3. This gene is at a genetic distance of 0.9 cM from a group of seven closely linked AFLPs. The location of the gene in a high recombinogenic region indicated a physical distance of approximately 1 Mb to the markers.

Cloning and mapping of genes involved in wheat-leaf rust interaction through gene-expression analysis using chromosome-deleted near-isogenic wheat lines

Molecular markers on wheat chromosome 6BL were isolated using mRNA differential display. Two wheat isolines inoculated with Puccinia recondita were analysed: Sinvalocho MA line carrying the Lr3 gene for leaf rust resistance on distal chromosome 6BL, and a rust-susceptible derivative of the Sinvalocho MA line with a deletion at the distal end of chromosome 6BL. Comparison of mRNA fingerprinting profiles, obtained from control and rust-inoculated plants, let to the isolation of 34 differentially displayed cDNAs. All these genes, except TaRr16, were up-regulated in the rust-inoculated resistant line. TaRr16 has constitutive expression in the rust-resistant line while no expression was detected in the rust-susceptible line. A number of those cDNAs revealed homology to genes previously identified in other plant-pathogen interactions. Two out of the 34 cDNAs, mapped in the distal part of chromosome 6BL and TaRr16, was genetically linked to the Lr3 gene. DNA sequence differences and differential expression between non-allelic copies of TaRr16, are also reported.

Screening for hepatocellular carcinoma in Alaska natives infected with chronic hepatitis B: a 16-year population-based study

The benefits of screening hepatitis B surface antigen (HBsAg)-positive carriers for hepatocellular carcinoma (HCC) in terms of long-term survival have not been established. We conducted a prospective 16-year, population-based cohort study to determine the impact of screening for HCC in 1,487 HBsAg-positive Alaska native carriers with alpha-fetoprotein (AFP) determinations every 6 months. Men and nonpregnant women with an elevated AFP level were evaluated for the presence of HCC by ultrasound (US) examination. The long-term survival rate for patients whose HCC was detected by the screening program was compared with a historical control group of Alaska native patients with HCC from the same population who were clinically diagnosed with HCC between 1969 and October 1982, through a National Cancer Institute-sponsored Cancer Registry. Between October 1982 and December 1998, 26,752 AFP determinations in HBsAg carriers were performed. One or more AFP elevations were found in 61 men and 39 nonpregnant women. HCC was diagnosed in 32 patients (24 men and 8 women). HCC tumors less than 6 cm were found in 23 patients; 22 patients had resections, and 1 patient refused a resection. Compared with 12 patients with hepatitis B virus (HBV)-related HCC diagnosed from 1969 to October 1982, before this program, the 5- and 10-year survival rate for the 32 patients with HCC were 42% (P =.008) and 30% (P =.07), respectively. Five- and 10-year tumor-free survival rates for carriers who had a normal AFP level on initial screening and subsequently developed HCC were 29% (P =.004) and 24% (P =.024), respectively. Screening of HBsAg carriers with semiannual AFP was effective in detecting most HCC tumors at a resectable stage and significantly prolonged survival rates when compared with historical controls in this population.

Abdominal pain in children: a case of acalculous cholecystitis

Acalculous cholecystitis is a rare disease in children. Most cases are associated with systemic infections or with autoimmune pathologies, but it may also occur without predisposing factors. A case observed in an otherwise healthy child is reported.

Mapping of the leaf rust resistance gene Lr3 on chromosome 6B of Sinvalocho MA wheat

The Lr3 gene for resistance to race 66 of Puccinia recondita present in hexaploid wheat cv. Sinvalocho MA was mapped on chromosome 6B, using intervarietal polymorphic RFLP loci and the Amp-B1 isozyme gene as a centromere marker. The RFLP markers were located mainly in two subregions of chromosome 6BL. Six RFLP loci clustered in the centromeric region and one other, Xmwg798, cosegregated with the Lr3 gene. C-banding analysis of the leaf rust resistant standard 'Sinvalocho MA' line and three naturally occurring susceptible lines of 'Sinvalocho MA' revealed a terminal deletion on 6BL that covered 20% of its length in one susceptible line. Because Xmwg798 was missing in this line, both Xmwg798 and Lr3 were allocated to the deleted segment. Distorted segregations were observed for the proximal markers, suggesting a selection against gametes carrying the centromeric region of 'Sinvalocho MA'.Key words: wheat, RFLP, Lr3 gene, chromosome 6B, C-banding.

[Sepsis caused by Haemophilus influenzae type B with septic arthritis in an infant]

Septic arthritis is a serious pyogenic infection that may lead to permanent orthopedic sequelae. Infants represent the most of the cases. It usually develops as a result of bacterial seeding into the capillary-rich synovium in the course of a bacteremic episode. Etiology changes according to different ages; in children after the neonatal period but younger than 24 months, Haemophilus influenzae is the most frequent causative organism. A case of sepsis due to Haemophilus influenzae type b (Hib) with septic arthritis in a patient 3 months old, is reported. The child was admitted to the hospital with a very high temperature (39 degrees C) for five days. His right wrist and ankle appeared swelling and hyperemic. He was affected by congenital cardiopathy from birth. He was not immunizated against Hib. The blood colture was positive for Hib. The leukocyte count was 21,400 cell/mm3 with 55% of polymorphonuclear cells. During the second day of recovery, the patient was transfused, because of the very low value of hemoglobin (5.2 g/dl). The child was treated with netilmycina and ceftriaxone for 15 days. The temperature fell in two days. The articular pathology resolved in nearly ten days. The case reported confirms the importance of septic arthritis as a pathology that necessarily requires an early diagnosis and treatment. The Haemophilus influenzae vaccine, is recommended especially in immunocompromised or cardiopathic subjects and before the age of 2 years.

[Forceps delivery and long term follow-up urinary incontinence]

553 patients undergoing complete urodynamic evaluation were investigated concerning mode of delivery. Forceps delivery was not associated with worsened urethral competence and significant risk of subsequent incontinence.

[Unstable bladder and Sjögren syndrome. Clinical case]

A female patient developed severe detrusor instability years after a diagnosis of Sjogren syndrome. A common etiology could be possible if an association with viral demyelinization in Sjogren patients is confirmed. Vaginal Sicca syndrome was present and responded to a topical androgen-oestriol association with definite cytologic improvement. Anticholinergics were tolerated and moderately effective. Low initial dose were slowly increased (over three months) to avoid excessive mouth dryness and avoid gastrooesophageal symptoms.

[Ultrasonographic and urodynamic evaluation in stress incontinence]

Transvaginal sonography can show partial urinary penetration in the urethra in patients with no clinical incontinence. The Fluid Bridge Test-Pressure urodynamically demonstrates the same phenomenon. We compared these two technics in women with stress urinary incontinence (SUI). 49 patients underwent urodynamic testing and transvaginal sonography; 18 had SUI, 20 were asymptomatic postoperatively (Burch procedure) and 11 were normal controls. Urodynamics consisted of filling cystometry with saline (infusion speed: ml 70/min) using transurethral Foley catheter (n degree 14 Fr), and a profilometric-pressure Bard catheter (10 Fr); micturitional cystometry; uroflowmetry; clino- and orthostatic urethral pressure profile (UPP) (extraction speed: cm 0.5-1/sec; infusion speed: cm 1.2/min); sphincteric electromyography (EMG); FBT-P with the Bard catheter only. During extraction patients were requested to cough (stress condition). If the urethra is incompetent pressure is transmitted to the water column connected to the pressure transducer, and a "spike" is observed. A competent urethra shows little pressure variation. Ultrasound (US) equipment consisted in a General Electric (RT 3600) sonograph with an electronic transvaginal probe (7.5 MHz) inserted in a gel-lubricated condom. The probe was positioned in the vaginal vestibule in direct proximity to the urethra. Axial and coronal scannings were performed. Echo-imagings were submitted to "post-processing" on US recording equipment. Fluid penetration in the urethra was evident if iperchogenic "turbulence" was observed on playback of the dynamic sonogram on a videocassette recorder (VCR) connected to the sonograph. The SUI group shows leakage of water under stress without detrusorial activity and dynamic UPP with reduced transmission of abdominal pressure on the urethra.(ABSTRACT TRUNCATED AT 250 WORDS)

[Comparison of methods for the diagnosis of urinary obstruction in women]

The International Continence Society does not offer secure guidelines for the diagnosis of micturitional obstruction. The problem has been extensively addressed in relation to male voiding difficulties. Little is known on the subject in female patients. Two criteria for the diagnosis of obstructed micturition are in clinical use. The Sussett formula divides the maximum micturitional pressure by the square of the corresponding maximum urinary flow rate. Two cutoffs, corresponding approximately to the 90th and 95th centiles can be used (0.15, and 0.5). A more complex graphic nomogram developed by Schafer plots maximum flow versus maximum detrusor pressure, identifying obstruction and detrusor dysfunction simultaneously according to the author. We feel that these methods, extensively tested on a male population, can both be used on a female population. We noticed that in some instances the results were different. 469 women referred for micturitional disturbances underwent pressure/flow studies. 62 (13.2%) were obstructed according to the Schafer nomogram, 103 (21.9%) and 31 (6.6%) respectively using the Sussett mathematical formula using two different cutoffs (0.15 and 0.5). The two methods identify the same patients only if micturitional pressures are normal (40 to 60 cmH2O) to high (over 60 cmH2O) and the Sussett formula is used with a higher (95th centile) cutoff. This means that both methods are clearly insufficient in the diagnosis of obstruction if detrusor function is impaired. This can happen in case of chronic retention due to detrusor failure after a long-standing obstruction or for primary failures due to central nervous system lesions. Extreme care should be exercised if pressure-flow studies indicate obstruction at low micturitional pressures.(ABSTRACT TRUNCATED AT 250 WORDS)

[Acute urinary obstruction in pregnancy]

Five cases of acute urinary obstruction during pregnancy are presented. A complete urodynamic workup, including pressure-flow studies showed high micturitional pressures with little or no flow, with at least 60% residual urine. Filling cystometry, urethral profilometry (static and dynamic), pelvic electromyography were normal. Two cases were due to uterine pelvic incarceration. One of these cases happened very early during pregnancy, because of extensive fibroids. Any cause of abnormal uterine enlargement can lead to early obstruction. Three cases were associated with paraurethral abscess (skenitis in 2 cases, urethral diverticulum in 1). Manual reduction in case of pelvic incarceration or surgical draining and antibiotic therapy in case of abscess were effective in all cases. Immediate catheterization is possible and indicated as soon as urinary obstruction is diagnosed. This prevents neuromuscular dysfunction due to excessive bladder distention. The transurethral catheter might work as a stent, and periurethral surgical drainage is probably safer with a catheter in place. Suprapubic catheterization is probably less useful in this respect. An indwelling catheter removes any urgency in treatment. Voiding difficulties can persist for some days after surgical treatment. Urodynamic testing performed in all indicated acute micturitional obstruction. Anyway, it added little to the clinical understanding of the problem, which was obvious, and the Authors feel that extensive urodynamic testing should be limited to cases presenting with a complex preexisting dysfunction or performed after treatment if symptoms do not disappear completely. All clinically doubtful cases should likewise be investigated. If periurethral abscess or incarceration are evident, simple evaluation of residual urine percentage should be sufficient in establishing the diagnosis.