Effect of diisopropylfluorophosphate on the antibody response

The impact of the in-vivo administration of diisopropylfluorophosphate (DFP) on the antibody response in mice was examined. The antigen-specific plaque-forming cell (PFC) response of mice injected with DFP (4 mg/kg) at the time of immunization with a macrophage-dependent T-cell antigen, trinitrophenylated keyhole limpet hemocyanin (TNP-KLH) or sheep red blood cells (SRBC), was significantly depressed. In contrast, the injection of a similar dose of DFP had no effect on the PFC response of mice immunized with a macrophage-independent B-cell antigen, lipopolysaccharide (LPS). This differential effect suggests a possible detrimental effect of DFP on cells involved in antigen processing and/or presentation which are required for the antibody response to SRBC and TNP-KLH. These results, however, do not exclude T cells as a possible target and the cellular targets of DFP action remain to be established. The DFP-mediated depression of the PFC response to SRBC was still evident when DFP was given as early as 1 day before, but not 1 day after, the injection of antigen, suggesting that DFP may well affect an early event of the antibody response. For the secondary TNP-specific IgM PFC response, a significant depression was observed only when DFP was administered at the time of antigen challenge. The injection of DFP at the time of antigen priming, however, was effective in depressing the IgG, but not the IgM, PFC response. Therefore, DFP may also interfere with the generation of antigen-specific memory cells for the secondary IgG response.     

Delayed portal vein thrombosis after experimental radiofrequency ablation near the main portal vein

BACKGROUND: Portal venous blood flow may protect adjacent tumour cells from thermal destruction with radiofrequency ablation (RFA). This study aimed to investigate the local effect of RFA on the main portal vein branch, and the completeness of cellular ablation in its vicinity, with or without a Pringle manoeuvre using a porcine model. METHODS: This was an in vivo study on 23 domestic pigs. RFA using a cooled-tip electrode was performed 5 mm from the left main portal vein branch under ultrasonographic guidance for 12 min with (n = 10) or without (n = 10) a Pringle manoeuvre. Ten pigs were killed 4 h after the procedure to study the early effects of RFA and ten others were killed 1 week later to determine any delayed effect. As a control, sham operations with a Pringle manoeuvre for 12 min were performed on three pigs. The flow velocity changes of portal vein and hepatic artery were measured using Doppler ultrasonography, and the completeness of cellular ablation around the portal vein was assessed qualitatively by histochemical staining and quantitatively by measuring intracellular levels of adenosine 5'-triphosphate (ATP). RESULTS: In the absence of the Pringle manoeuvre, there was no significant change in mean(s.d.) portal vein flow velocity before RFA (20.0(3.5) cm/s) and at 4 h (18.5(2.5) cm/s) (P = 0.210) and 1 week (19.5(2.2) cm/s) (P = 0.500) after the procedure. Gross and histological examination of the portal vein branches showed no damage without the Pringle manoeuvre. In all pigs that underwent RFA with a Pringle manoeuvre, the portal vein was occluded 1 week after the operation; histological examination of the affected portal vein showed severe thermal injury and associated venous thrombosis. The local effect of RFA on the hepatic artery was similar. With intact portal blood flow during RFA, complete ablation of liver tissue around the pedicle was demonstrated by histochemical staining and measurement of the intracellular ATP concentration. CONCLUSION: RFA was safe when applied close to the main portal vein branch without a Pringle manoeuvre, with complete cellular destruction. Use of the Pringle manoeuvre resulted in delayed portal vein and hepatic artery thrombosis and injury to the hepatic artery and bile duct.     

Levator defects can be detected by 2D translabial ultrasound

Introduction and hypothesis  Childbirth-related morphological abnormalities or defects of the puborectalis muscle (“avulsion”) can be diagnosed by magnetic resonance imaging and three-dimensional (3D) ultrasound, but neither method is universally available. In this study, we tested validity and reproducibility of a new method for diagnosing levator avulsion by 2D translabial ultrasound. Methods  Seventy-five women were examined for major morphological abnormalities of the puborectalis muscle by palpation, 2D and 3D ultrasound (US). For 2D US, we used an oblique parasagittal translabial approach. The operator using 2D US was blinded against all other findings. Results  Agreement between observers for diagnosis of avulsion by 2D US was 87% (Cohen’s kappa 0.56, CI 0.33–0.80). Agreement between tomographic 3D US and 2D US was 87% (kappa 0.61, CI 0.45–0.77). Conclusions  Defects of the puborectalis muscle can be diagnosed with 2D US. The finding of a discontinuity between the hyperechogenic muscle and the pelvic sidewall is moderately reproducible and agrees moderately well with palpation and 3D US.     

MR imaging of facial nerve enhancement in Bell palsy or after temporal bone surgery

The authors evaluated magnetic resonance (MR) images obtained with intravenously administered gadolinium in ten patients who had facial paralysis and no facial nerve tumor. In patients with either Bell palsy (four patients) or facial paralysis after temporal bone surgery (six patients), intratemporal facial nerve enhancement was seen. Facial nerve enhancement on MR images proved to be a nonspecific finding.     

Effect of a milk formula containing probiotics on the fecal microbiota of asian infants at risk of atopic diseases

The fecal microbiota of 37 infants with (n = 20) or without (n = 17) probiotic administration was evaluated on D 3, and at 1, 3, and 12 mo by fluorescence in situ hybridization-flow cytometry (FISH-FC), PCR, and bacteriological culture methods. They represent consecutive subjects of an ongoing double-blind, placebo-controlled trial on a probiotic formula (LGG and Bifidobacterium longum) administered during the first 6 mo of life. Despite varying composition in each baby, there was a general bacterial colonization pattern in the first year. Bifidobacteria increased markedly (p = 0.0003) with a parallel decrease in Enterobacteriaceae (p < 0.001) and Bacteroides-Prevotella (p = 0.005) populations. Eubacterium rectale-Clostridium coccoides (p < 0.001) and Atopobium (p = 0.039) groups also gradually increased. This overall pattern was unaffected by probiotic administration (p > 0.05). B. longum (p = 0.005) and Lactobacillus rhamnosus (p < 0.001) were detected more frequently in probiotic group during supplementation, but no difference after supplementation had ceased (p > 0.05). Cultured lactic acid bacteria were also more numerous in the probiotic-administered babies during treatment period (log CFU/g 8.4 versus 7.4; p = 0.035). Our results indicate that supplemented strains could be detected but did not persist in the bowel once probiotic administration had ceased.     

Danish primary schoolteachers'' knowledge about asthma: results of a questionnaire

We present an anonymous questionnaire inquiry involving 334 primary schoolteachers in the Randers area with the purpose of elucidating teachers' knowledge about asthma. To a series of statements about asthma, the teachers answered yes, no or don't know. A limited knowledge of different aspects of asthma in children was found, although 57% had asthma children in their classes. Specially limited was knowledge about medical treatment. Five percent had received proper instruction about asthma and had a significantly better knowledge of medical treatment (p less than 0.001-0.05). Only 57% knew that wheezing after physical exertion is a strong indicator of asthma and only 33% knew that exertion in cold weather increases the risk of an attack. It is recommended that instruction in children's diseases, especially asthma, is introduced in teacher training colleges.     

Post-transplantation lymphoproliferative disease in Chinese: the Queen Mary Hospital experience in Hong Kong

Post-transplantation lymphoproliferative disease (PTLD) is an unique iatrogenic complication after bone marrow transplantation (BMT) and solid organ transplantation (SOTx). The pattern of EBV related lymphoma in Chinese is different from Caucasians. We surveyed the incidence, clinical and pathological spectrum of PTLD among 541 cases of allogeneic BMT, 145 cases of renal transplant, 35 cases of heart/lung transplantation and 146 cases of orthotopic liver transplantation (OLT). From 1994 to 2001, 13 consecutive cases of PTLD were diagnosed, ranging from disseminated NK cell lymphoma to localized plasmacytoma. Both donor and recipient derived PTLD was documented. Disease was often heralded by cytomegaloviral disease and antithymocyte globulin (ATG) usage. Two cases were diagnosed post-mortem, and six patients died of PTLD at a median of 3 months. Complete and partial remission was only achieved in 3 and 2 cases, respectively, despite a range of treatment (reduced immunosuppression, explantation, radiotherapy, combination chemotherapy, donor lymphocytes, autologous marrow infusion and rituximab). Most responding patients died subsequently of rejection, infection and graft versus host disease (GVHD). The incidence of PTLD is not increased in Chinese patients. However, some patients may be at increased risk, especially mismatched allogeneic BMT, parental OLT (especially involving young infants) and heavy ATG exposure.     

Improved delivery through biological membranes. 2. Distribution, excretion, and metabolism of N-methyl-1,6-dihydropyridine-2-carbaldoxime hydrochloride, a pro-drug of N-methylpyridinium-2-carbaldoxime chloride.

N-Methyl-1,6-dihydropyridine-2-carbaldoxime hydrochloride, the pro-drug of 2-PAM, was found to be converted in vivo to 2-PAM, rapidly and quantitatively. The significantly changed properties of the pro-2-PAM resulted in a longer biological half-life and a favorable distribution of 2-PAM formed upon its oxidation. No new metabolite was found when pro-2-PAM was administered intravenously; however, a new metabolic product was formed when the pro-drug was given by oral route.