Role of the Agrobacterium tumefaciens VirD2 protein in T-DNA transfer and integration

VirD2 is one of the key Agrobacterium tumefaciens proteins involved in T-DNA processing and transfer. In addition to its endonuclease domain, VirD2 contains a bipartite C-terminal nuclear localization sequence (NLS) and a conserved region called omega that is important for virulence. Previous results from our laboratory indicated that the C-terminal, bipartite NLS and the omega region are not essential for nuclear uptake of T-DNA, and further suggested that the omega domain may be required for efficient integration of T-DNA into the plant genome. In this study, we took two approaches to investigate the importance of the omega domain in T-DNA integration. Using the first approach, we constructed a T-DNA binary vector containing a promoterless gusA-intron gene just inside the right T-DNA border. The expression of beta-glucuronidase (GUS) activity in plant cells transformed by this T-DNA would indicate that the T-DNA integrated downstream of a plant promoter. Approximately 0.4% of the tobacco cell clusters infected by a wild-type A. tumefaciens strain harboring this vector stained blue with 5-bromo-4-chloro-3-indolyl beta-D-glucuronic acid (X-gluc). However, using an omega-mutant A. tumefaciens strain harboring the same binary vector, we did not detect any blue staining. Using the second approach, we directly demonstrated that more T-DNA is integrated into high-molecular-weight plant DNA after infection of Arabidopsis thaliana cells with a wild-type A. tumefaciens strain than with a strain containing a VirD2 omega deletion/substitution. Taken together, these data indicate that the VirD2 omega domain is important for efficient T-DNA integration. To determine whether the use of the T-DNA right border is altered in those few tumors generated by A. tumefaciens strains harboring the omega mutation, we analyzed DNA extracted from these tumors. Our data indicate that the right border was used to integrate the T-DNA in a similar manner regardless of whether the VirD2 protein encoded by the inciting A. tumefaciens was wild-type or contained an omega mutation. In addition, a mutant VirD2 protein lacking the omega domain was as least as active in cleaving a T-DNA border in vitro as was the wild-type protein. Finally, we investigated the role of various amino acids of the omega and bipartite NLS domains in the targeting of a GUS-VirD2 fusion protein to the nucleus of electroporated tobacco protoplasts. Deletion of the omega domain, or mutation of the 10-amino-acid region between the two components of the bipartite NLS, had little effect upon the nuclear targeting of the GUS-VirD2 fusion protein. Mutation of both components of the NLS reduced, but did not eliminate, targeting of the fusion protein to the nucleus.     

Telephone communication with in-the-ear hearing aids using acoustic and electromagnetic coupling

The purpose of this study was to determine whether telephone communication was improved with electromagnetic coupling for in-the-ear hearing aid users with mild to moderate hearing losses. Each user adjusted his hearing aid gain to the level he determined to be best for telephone communication with each coupling method. Under these conditions, average word recognition scores in quiet and average high-frequency output levels measured at the tympanic membrane were not different for each coupling method. The ability to tolerate background noise was also studied. Background noise tolerance was not different for the two coupling methods. However, significantly greater levels of background noise were tolerated when telephone side-tone feedback was eliminated regardless of coupling method.     

A review of major nursing vocabularies and the extent to which they have the characteristics required for implementation in computer-based systems

Fertilised mouse eggs develop the oolemma block to sperm penetration within 1 h. This block makes zona-free eggs at the pronuclear stage (zygotes) fully resistant to sperm penetration. In this study we investigated whether this block can spread--as a result of cell fusion--to the oolemma of eggs that are competent to be penetrated by spermatozoa. Preovulatory (GV) oocytes, ovulated oocytes in metaphase II (MII) and 1-cell parthenotes were fused with zygotes and the hybrid cells inseminated at various intervals after fusion. Sperm penetration was assessed on the basis of the presence of Giemsa-positive sperm heads in the air-dried preparations. The oolemma block to sperm penetration develops in all types of hybrids although at different speeds: it develops fast (2-3 h) in oolemma derived from MII oocytes and artificially activated eggs, and slowly in oolemma derived from GV oocytes. In the GV oocyte-zygote hybrids the time of formation of the block varied: while 50% of cells lost the ability to fuse with sperm by 2 h after fusion, in the remaining cells the block must have developed some time between 5 and 18 h after fusion. How these sperm-induced modifications of the oolemma of fertilised egg spread in the hybrid cell and render the 'virgin' part of oolemma resistant to sperm penetration remains unknown.     

Laparoscopic orchiopexy: procedure of choice for the nonpalpable testis?

PURPOSE: Multiple approaches exist for the management of the nonpalpable testis. With the use of diagnostic laparoscopy widely accepted in the setting of the nonpalpable testis we have found laparoscopic orchiopexy to be an efficient and logical extension. To evaluate its use we report our experience with laparoscopic orchiopexy to treat 44 nonpalpable testes in 36 patients. MATERIALS AND METHODS: We retrospectively reviewed the medical records of all patients who underwent laparoscopic orchiopexy for a 2 1/2-year period. Modifications of the surgical technique are described. RESULTS: The left testis was affected in 18 boys, the right in 9 and both in 9. At laparoscopy 8 testes were at the internal ring or were peeping and the remainder were intra-abdominal. One patient underwent a unilateral 1-stage Fowler-Stephens orchiopexy, and 3 unilateral and 1 bilateral 2-stage Fowler-Stephens orchiopexy. Two patients underwent laparoscopically assisted orchiectomy. The remaining 31 patients underwent laparoscopic orchiopexy without division of the spermatic vessels. At followup (mean 6 months) all testes are without atrophy, and 39 of 42 (93%) are in an acceptable scrotal position. There are 3 testes (7%) high in the scrotum. CONCLUSIONS: Laparoscopic orchiopexy is a logical extension of diagnostic laparoscopy for the evaluation and treatment of the nonpalpable testis. The low incidence of complications and 93% success rate underscore the feasibility of this procedure. It is our procedure of choice for the treatment of nonpalpable testis.     

What do cancer patients mean when they complain of concentration and memory problems?

Cognitive function items are increasingly included in quality of life measures, and complaints of concentration and memory difficulties are often reported by cancer patients. The aim of this study was to examine the factors influencing patients' level of complaint by comparing subjective reports with objective test performance of a sample of adult lymphoma patients, disease-free and > or = 6 months after treatment. There was no significant difference between complainers and non-complainers in sociodemographic or clinical characteristics or in their performance on standard neuropsychometric tests of concentration and memory. Those reporting concentration and memory difficulties had significantly higher scores on measures of anxiety, depression and fatigue. This calls into question the validity of including cognitive function items in self-report quality of life measures. Patients who report concentration and memory difficulties should be screened for clinically significant and potentially remediable mood disorder. Objective testing remains the method of choice for assessing higher mental function.     

The neuropathology of HIV-infected African children in Abidjan, C?te d'Ivoire

In an autopsy study of HIV-infected children in Abidjan, C?te d'Ivoire, the neuropathology of 76 HIV-1- and 2 HIV-2-positive children was compared with that of 77 frequency-matched HIV-negative children, in whom the systemic pathology was also known. Seventy of the 78 HIV-seropositive children were confirmed as HIV-infected, as determined by combined serology, IgA Western blots and clinicopathological criteria. The HIV-negative children showed a high background level (n = 49, 64%) of neuropathological abnormalities, including nonspecific inflammatory infiltrates, micromineralization, and bacterial and lymphocytic meningitis. In the HIV-positive children, HIV encephalitis was found in 4 (6%), cytomegalovirus in 2 (3%), toxoplasmosis in 3 (4%) and measles encephalitis in one (1%). Bacterial meningitis was equally common in both groups, but cerebral malaria was less common (n = 2, 3%) in HIV-positive than in HIV-negative children (n = 11, 14%). The low prevalence of HIV encephalitis may reflect comparatively early death in HIV infection in Africa as compared with our experience in Europe and the US.     

Efficacy of indirect haemolysis test in the diagnosis of human brucellosis

The authors report one operated case of traumatic sternal segmental dislocation in a child, and propose a mechanism for this uncommon lesion. A fourteen year old boy was admitted in emergency for anterior chest pain, occurring during an exercise in parallel bars without any fall. X ray showed traumatic dislocation of the upper sternal segment. After 12 hours, because of bad clinical tolerance (pain, dyspnea with sweats and disphagia) reduction and plate stabilization (Senegas plate) was performed with immediate pain relief. The boy returned to school after 10 days. Plate was removed two months later after healing, with good clinical and radiological results. According to rare published cases, conservative treatment can be proposed in very young children because of dislocation remodeling. By others, in case of bad tolerance, surgical treatment is suggested despite the inconvenient of device's removal. The originality of this case is the indirect lesion mechanism. Hypothesis is given by authors. Treatment by plate is easy and gives immediate pain relief with good clinical and radiological results in teen-agers.