Spontaneous regression of suspected cystic dysplasia of the rete testis in three neonates.

INTRODUCTION: Cystic dysplasia of the rete testis (CDRT) is a rare cause of scrotal swelling during infancy. It is a benign lesion that is often associated with ipsilateral renal, ureteral or genital abnormalities. Leissring and Oppenheimer described it for the first time in 1973. CASE REPORTS: Since 2006, three neonates were referred to our pediatric surgery department because of a scrotal swelling related to intra-testicular cysts. Physical examination showed enlarged testicles without pain or inflammation. The ultrasound scan (USS) showed enlarged testicles related to multiple small cysts surrounded by normal parenchyma, and no other urinary abnormalities. As CDRT was suspected, a conservative strategy was proposed with repeated clinical examinations and USS. The cysts gradually regressed and disappeared in all cases, with a mean follow-up of 52 months. DISCUSSION: As reported by Jeyaratnam et al., mean age at presentation was around 6 years. The most frequently associated urinary abnormalities were renal agenesis and multicystic dysplasia of the kidney. Differential diagnosis of CDRT included single testicular cyst, epidermoid cyst, albugina cyst, teratoma, cystic lymphangioma, testicular juvenile granulosa cell tumor, cystic transformation after orchitis, or spermatic cord torsion. Ultrasonography was the method of choice for the diagnosis of CDRT and its follow-up. The USS showed multiple small cysts with normal, but compressed, surrounding testicular parenchyma. A high-frequency transducer was mandatory to exclude other causes of scrotal swelling. With the involution of the cysts, the aspect of the parenchyma could be slightly heterogeneous or confused with microlithiasis. Historically, orchidectomy was the proposed treatment. However, because of a more precise diagnosis with USS, a conservative approach has been proposed. Nonetheless, recurrence after sparing surgery was frequent, as reported by many authors. Non-surgical management was reported in selected cases, sometimes after a surgical biopsy to confirm a benign lesion. Spontaneous regression of CDRT without any sequelae has been reported in six cases (see Summary Table) but long-term follow-up in the adult population has never been published. Limitations of the present series were related to the small number of cases, the absence of follow-up beyond puberty, and the absence of biopsy to confirm the diagnosis of CDRT. CONCLUSION: Spontaneous regression of CDRT was possible, and conservative attitude was an option, as CDRT is a benign lesion. Careful and prolonged 'watch and wait' management was a safe alternative to surgery, but other causes of scrotal swelling must be excluded, possibly with a testicular biopsy.

Identification of a novel pathogen-responsive element in the promoter of the tobacco gene HSR203J, a molecular marker of the hypersensitive response.

The tobacco gene, HSR203J, which is specifically activated during the early steps of incompatible plant/pathogen interactions has been shown to be a molecular marker of the hypersensitive response (HR). It constitutes an ideal model for the identification of HR-responsive cis-regulatory elements. As a first step in the promoter dissection, deletion mutants of the 5' flanking sequence of HSR203J fused to the GUS reporter gene were analyzed. Then, the construction and study of chimeric constructs containing HSR203J promoter fragments fused to a minimal promoter enabled us to identify a 28-bp regulatory element located between -106 and -79 upstream of the transcription initiation site. This element has been shown to be necessary and sufficient for transcriptional activation in response to pathogen. It contains a 10-bp palindrome followed by its imperfect repeat. The mutagenesis of these two sequence elements led to the identification of a 12-bp motif termed HSRE (HSR203 responsive element) responsible for the marked induction of the HSR203J gene during the HR. Since this DNA region did not show any homology with known regulatory sequences, this 12 bp motif corresponds to a novel cis-regulatory element.

Characterization of an Arabidopsis thaliana receptor-like protein kinase gene activated by oxidative stress and pathogen attack.

An Arabidopsis thaliana cDNA clone that encodes a putative receptor-like protein kinase gene (At-RLK3) was characterized. The deduced 667-amino acid protein consists of an amino-terminal signal sequence, an extracellular domain, a single transmembrane domain, and a cytoplasmic domain with characteristics of serine/threonine protein kinase. Because of the original features of its extracellular domain, the At-RLK3 protein is a member of a new class of receptor-like protein kinases. The At-RLK3 gene is present as a single copy within the Arabidopsis genome and its transcripts are detected in root, stem, leaf and flower. In cultured cells, the At-RLK3 gene is activated upon oxidative stress and salicylic acid treatment. In plants, the gene appears to be differentially regulated during various plant-pathogen interactions: upon inoculation with strains of Pseudomonas syringae pv. tomato harboring or not, different avr genes, At-RLK3 transcripts accumulate transiently at similar levels during both compatible and incompatible interactions. This gene is, however, preferentially expressed during the incompatible interaction induced by the soil-borne vascular bacteria, Ralstonia solanacearum. The involvement of At-RLK3 in signal transduction pathways during pathogen attack is discussed.

Genetic characterization of RRS1, a recessive locus in Arabidopsis thaliana that confers resistance to the bacterial soilborne pathogen Ralstonia solanacearum.

The soilborne, vascular pathogen Ralstonia solanacearum, the causative agent of bacterial wilt, was shown to infect a range of Arabidopsis thaliana accessions. The pathogen was capable of infecting the Col-5 accession in an hrp-dependent manner, following root inoculation. Elevated bacterial population levels were found in leaves of Col-5, 4 to 5 days after root inoculation by the GMI1000 strain. Bacteria were found predominantly in the xylem vessels and spread systematically throughout the plant. The Nd-1 accession of A. thaliana was resistant to the GMI1000 strain of R. solanacearum. Bacterial concentrations detected in leaves of Nd-1, inoculated with an hrp+ strain of R. solanacearum, were only slightly higher than those detected in the susceptible accession, Col-5, following inoculation with a strain whose hrp gene cluster was deleted. Leaf inoculation of the GMI1000 strain on the resistant accession Nd-1 induced the formation of lesions in the older leaves of the rosette whereas the same strain of R. solanacearum provoked complete wilting of Col-5. Resistance to strain GMI1000 of R. solanacearum segregated as a simply inherited recessive trait in a genetic cross between Col-5 and Nd-1. F9 recombinant inbred lines generated between these two accessions were used to map a locus, RRS1, that was the major determinant of resistance between restriction fragment length polymorphism markers mi83 and mi61 on chromosome V. This region of the A. thaliana genome is known to contain many other pathogen recognition capabilities.