Combined use of the intravascular blood-pool agent, gadomer, and carbon dioxide: a novel type of double-contrast magnetic resonance angiography (MRA)

PURPOSE: To evaluate the combined use of carbon dioxide (CO(2)) and a gadolinium-based blood-pool agent for magnetic resonance angiography (MRA). MATERIALS AND METHODS: After an initial intravenous injection of the blood-pool agent Gadomer (Schering AG, Germany), repeated transcatheter CO(2) injections were performed in the aorta and the renal arteries of two fully-anesthetized pigs. Real-time images were acquired using a true fast imaging with steady-state precession (FISP) sequence. RESULTS: During the CO(2) injections, the Gadomer-enhanced blood was totally replaced, resulting in an immediate, temporary, total signal loss in the vessel lumen. Susceptibility artifacts during the injections or catheter manipulations rarely occurred. CONCLUSION: Due to T1-shortening, the circulating blood-pool agent prevents flow artifacts during catheter manipulations because the steady-state is reached much earlier. Therefore, this double-contrast MRA method improves catheter conspicuity and might be helpful for guiding and controlling intravascular procedures during interventional MRI.     

Surgical treatment of achilles tendon rupture: examination of strength of 3 types of suture techniques in a cadaver model

BACKGROUND: The mechanical properties of present-day percutaneous repairs of Achilles tendon ruptures are not known. MATERIAL AND METHODS: Artificially-created ruptures in 24 human cadaveric Achilles tendons were repaired with an open Bunnell repair, a percutaneous calcaneal tunnel or a percutaneous bone-anchor repair. In the open technique no.1 PDS-II absorbable suture material was used, and in the percutaneous techniques either no.1 PDS-II or no.1 Panacryl absorbable suture material was used. The specimens were tested in a materials testing machine until failure occurred. RESULTS: The common mode of failure was suture breakage in non-anchor repairs, and anchor pullout in anchor repairs. The average strength of the repairs varied from 166 N (SD 60) to 211 N (SD 30), with no differences between the techniques (p = 0.5). INTERPRETATION: Taking costs into account, the percutaneous calcaneal tunnel technique and the open technique are the methods of choice.     

Management of asymptomatic anthracycline-induced cardiac damage after treatment for childhood cancer: a postal survey among Dutch adult and pediatric cardiologists

Asymptomatic anthracycline-induced cardiac damage (A-CD) is a serious problem among young childhood cancer survivors. The aim of this survey was to assess the current treatment policy in these patients in the Netherlands. A questionnaire was sent to all 136 departments of adult or pediatric cardiology in the Netherlands. It was returned by 61% of the departments. Sixty-six percent of the respondents started medical treatment (ie, an ACE inhibitor and/or a beta-blocker) in childhood cancer survivors with asymptomatic A-CD. Fifty-eight percent of the respondents indicated that their treatment decision was based on published findings in the literature, but none of them referred to studies evaluating the treatment of asymptomatic A-CD. A majority of adult and pediatric cardiologists started medical treatment in childhood cancer survivors with asymptomatic A-CD without knowledge of the benefits and risks of treatment in this patient group. Before ACE inhibitors and/or beta-blockers can be recommended as routine practice in childhood cancer survivors with asymptomatic A-CD, randomized controlled trials should be performed. Until then, the authors recommend centralizing the treatment of childhood cancer survivors with asymptomatic A-CD in a specialized center to cluster the available knowledge and experience.     

Sequential switching of DNA polymerase and thymidine kinase-mediated HSV-1 drug resistance in an immunocompromised child

Sequential herpes simplex virus type 1 (HSV-1) isolates were obtained from a paediatric haematopoietic stem cell transplant (HSCT) patient who received prolonged therapy with acyclovir (ACV) followed by foscarnet (PFA) and topical cidofovir (HPMPC) for severe persistent mucocutaneous HSV-1 infection. The isolates were retrospectively studied for drug resistance. The first resistant isolate associated with clinical failure of antiviral therapy emerged 44 days post-ACV treatment initiation. Susceptibility testing revealed an ACV-resistant HSV strain that demonstrated cross resistance to PFA in the absence of any previous PFA treatment. The observed cross resistance was conferred by a single amino acid substitution, Ser724Asn, in the HSV DNA polymerase (DNA pol) gene. During the subsequent course of ACV therapy, the ACV/PFA-cross-resistant isolates were replaced by ACV-resistant, PFA-sensitive isolates. These isolates carried no DNA pol mutations, but had an Arg163His substitution in the thymidine kinase gene. Upon subsequent switching of antiviral therapy from ACV to PFA, the original ACV/PFA-cross-resistant DNA pol mutant re-appeared. Our study shows the emergence of different drug-resistant HSV variants during ongoing, unchanged ACV therapy. Furthermore, a rapid re-selection of the original resistant variant was observed after switch. For optimal antiviral management of HSV infections in HSCT recipients, therapeutic decisions should be guided by drug susceptibility results whenever therapeutic failure is observed and/or when changes in antiviral treatment are considered.     

Prevention of pterygium recurrence by postoperative single-dose beta-irradiation: a prospective randomized clinical double-blind trial

PURPOSE: To affirm the effectiveness and complication rate of postoperative single-dose beta-irradiation (RT) with (90)Sr in the case of primary pterygium in a clinical trial. Pterygium is a benign disease of the supporting orbital tissue that can cause impairment of visual function. Depending on the technique used for surgery, recurrence is described in up to 70% of cases-a reason to combine the initial treatment with radiotherapy or chemotherapy. METHODS AND MATERIALS: This trial was designed as a prospective, randomized, multicenter, double-blind study. Surgery was performed in all cases according to the bare sclera technique. Ninety-one patients with 96 pterygia were postoperatively randomized to either beta-RT or sham RT. In the case of beta-RT, a (90)Sr eye applicator was used to deliver 2500 cGy to the sclera surface at a dose rate of between 200 and 250 cGy/min. Sham RT was given using the same type of applicator without the (90)Sr layer. After treatment, both an ophthalmologist and a radiation oncologist performed the follow-up examinations. The accumulated data were analyzed using a group sequential test. RESULTS: Between February 1998 and September 2002, 96 eyes with primary pterygium were operated on according to the trial protocol. Additional treatment was performed within 24 hours postoperatively. Ten patients were lost to follow-up, resulting in 86 patients who could be analyzed. In the 44 eyes randomized to receive beta-RT, 3 relapses occurred compared with 28 recurrences in the 42 eyes that received sham RT, for a crude control rate of 93.2% vs. 33.3%, respectively. At a mean follow-up of 18 months, major treatment complications had not been observed. CONCLUSION: Single-dose beta-RT after bare sclera surgery is a simple, effective, and safe treatment that reduces the risk of primary pterygium recurrence.     

Assessing structural and functional plankton responses to carbendazim toxicity

A model ecosystem experiment was conducted to investigate the ability of an in situ Daphnia magna feeding bioassay to assess impairment of ecosystem function. Animals were deployed in model ecosystems dosed with different concentrations of the fungicide carbendazim, and effects on the postexposure feeding rate of D. magna were compared with effects on zooplankton species richness (ecosystem structure) and development of phytoplankton biomass (ecosystem function). In the medium-dosed systems (21 microg/L), a structural change was observed within the zooplankton community, but no indirect effects on phytoplankton development were detected. It appears that at this treatment level, functional redundancy was sufficient to prevent functional impairment despite species loss. The feeding assay did not show any response at this concentration. In the high-dosed systems (221 microg/L), structural changes in the zooplankton community were accompanied by increased development of phytoplankton biomass. The feeding bioassay also showed a significant response at this concentration. At the high treatment level, species loss resulted in functional impairment, indicating that at this level, functional redundancy could not compensate for loss of individuals. The D. magna feeding bioassay matched well with the functional response (i.e., the indirect effects on phytoplankton) in the dosed systems but not with the more subtle effects on zooplankton community structure. These results lend positive support to the use of in situ feeding bioassays in combination with structural indices, such as species richness, to assess the effects of stress on ecosystem functioning in a direct way.     

Effects of a brief intervention program for patients with cancer and their partners on feelings of inequity, relationship quality and psychological distress

When one member of a couple develops a serious illness, the lives of both partners are likely to be affected. Interventions directed at both partners are generally lacking, however. In the present study, a brief counseling program directed at couples confronted with cancer was evaluated. The intervention focused mainly on the exchange of social support and help between both partners and was aimed at restoring perceptions of equity. Couples were randomly assigned to an experimental group or a waiting-list group. After the intervention, both patients and their partners reported lower levels of perceptions of underinvestment and overbenefit, and higher levels of relationship quality. Moreover, among patients psychological distress decreased after the intervention. These effects were generally maintained until follow-up three months later. Associations between perceptions of equity and relationship quality and psychological distress were also examined.     

Development of cortisol circadian rhythm in infancy

BACKGROUND AND AIMS: Cortisol is the final product of the hypothalamus-pituitary-adrenal (HPA) axis. It is secreted in a pulsatile fashion that displays a circadian rhythm. Infants are born without a circadian rhythm in cortisol and they acquire it during their first year of life. Studies do not agree on the age of appearance of the circadian rhythm (varying between 2 weeks till the age of 9 months) nor on whether it is related to the appearance of the sleep-wake circadian rhythm. The object of the present study was to find evidence of the age of appearance of the diurnal rhythm of cortisol and to compare the results obtained by several different analysis methods on a new data set. DESIGN AND MEASURES: Cortisol was determined in salival samples of 14 normally developing infants who were followed monthly between the ages of 2 and 5 months. The data were analyzed with several previously published analysis methods as well as with Multilevel Analysis (Hierarchical Linear Modeling). RESULTS: The previously published analysis methods each produced different results when applied to the current data set. Moreover, our results indicate striking differences between young infants in both age of appearance and stability of the diurnal cortisol rhythm. Also, a link was found between the appearance of the sleep-wake circadian rhythm and the cortisol circadian rhythm. An important intraindividual variability in cortisol levels was found even after correcting for the different variables that affect cortisol (i.e. time of sampling, feeding, etc.). CONCLUSIONS: Although the choice of analysis method influences the age of appearance obtained, our use of HLM shows that the infants' own variability in onset and stability of the cortisol circadian rhythm greatly contributes to the different results.