Development of a vaccine for immunization against classical as well as variant strains of infectious bursal disease virus using reverse genetics

Available IBDV vaccines based on classical IBDV strains do not induce full protection in the presence of maternally derived antibodies (MDA) against variant strains. The aim of this study was the generation of an IBDV chimera between both classical and variant strains. Characterization of the generated chimeric IBDV (D78-Chim) was performed in both cell culture and susceptible chickens using the classical vaccine strain D78 for comparison. Growth kinetics on cell culture showed that the D78-Chim replicates comparable to the live vaccine strain D78. Administration of the D78-Chim to SPF chickens resulted in equally high virus neutralizing antibodies titres against both, classical and variant IBDV strains. In vivo experiments in commercial chickens revealed that D78-Chim and D78 induced comparable bursal damage in presence of maternally derived antibodies. Both D78-Chim and D78 viruses were able to breakthrough a similar level of MDA.     

Effect of antithymocyte globulin on quantitative immune recovery and graft-versus-host disease after partially T-cell-depleted bone marrow transplantation: a comparison between recipients of matched related and matched unrelated donor grafts

The effect of antithymocyte globulin (ATG) on quantitative immune recovery and graft-versus-host disease (GVHD) after partially T-cell-depleted bone marrow transplantation was analyzed in 59 and 32 recipients of grafts from matched related donors and matched unrelated donors (MUDs), respectively. The conditioning regimen was similar in all patients, except for ATG which was given only to MUD recipients. Thirteen MUD patients were treated with high-dose (20 mg/kg) ATG and 19 with low-dose (8 mg/kg) ATG. During the posttransplant period, CD3+, CD4+, and CD8+ T-cell numbers and the incidence of acute and chronic GVHD were significantly lower in MUD recipients compared with matched related donor recipients. MUD recipients treated with high-dose ATG showed the worst T-cell and subsets recovery. These data indicate that ATG, often used as part of conditioning regimens in recipients of T-cell-depleted grafts from MUDs, contributes to the severe and prolonged T-cell deficiency that is typical of these patients. On the other hand, it effectively reduces the incidence and severity of GVHD.     

Effects of dietary folate and alcohol intake on promoter methylation in sporadic colorectal cancer: the Netherlands cohort study on diet and cancer

Sporadic colorectal cancer (CRC) is characterized by genetic and epigenetic changes such as regional DNA hypermethylation and global DNA hypomethylation. Epidemiological and animal studies suggest that aberrant DNA methylation is associated with low dietary folate intake, which is aggravated by high alcohol intake. The relationship between promoter methylation of genes involved in CRC carcinogenesis and folate and alcohol intake was investigated. Methylation of the APC-1A, p14(ARF), p16(INK4A), hMLH1, O(6)-MGMT, and RASSF1A promoters was studied using methylation-specific PCR in 122 sporadic CRCs, derived from patients with folate and alcohol intake at either the lower or the higher quintiles of the distribution. Overall, promoter hypermethylation frequencies observed were: 39% for APC; 33% for p14(ARF); 31% for p16(INK4A); 29% for hMLH1; 41% for O(6)-MGMT; and 20% for RASSF1A. For each of the tested genes, the prevalence of promoter hypermethylation was higher in CRCs derived from patients with low folate/high alcohol intake (n = 61) when compared with CRCs from patients with high folate/low alcohol intake (n = 61), but the differences were not statistically significant. The number of CRCs with at least one gene methylated was higher (84%) in the low folate intake/high alcohol intake group when compared with the high folate intake/low alcohol intake group (70%; P = 0.085). Despite the size limitations of this study, these data suggest that folate and alcohol intake may be associated with changes in promoter hypermethylation in CRC.     

Condom use promotes regression of human papillomavirus-associated penile lesions in male sexual partners of women with cervical intraepithelial neoplasia

Penile HPV-associated lesions are frequently seen in male sexual partners of women with CIN. The natural course and clinical significance of these lesions are unclear. Women with CIN and their male sexual partners were randomized for condom use (condom group n = 68, noncondom group n = 68). Males were screened for the presence of penile lesions, i.e., flat lesions, papular lesions and condylomata acuminata, and of HPV in their penile swabs by PCR testing. Median follow-up time was 13.1 months (range 2.9-57.4). The outcome of our study was clinical regression of penile lesions defined as disappearance of lesions at penoscopy. Potentially prognostic factors, i.e., HPV status, lesion type and age, were studied as well. Outcomes were assessed in 57 men of the condom group and in 43 men of the noncondom group. Condom use shortened the median time to regression of flat penile lesions (7.4 months condom group vs. 13.9 months noncondom group; HR = 2.1, 95% CI 1.2-3.7). This effect was not found for papular lesions (HR = 0.5, 95% CI 0.1-2.8). HPV-negative men showed a significantly shorter median time to regression of flat lesions (3.8 months) compared to men with either HPV-positive status (8.5 months; HR = 0.4, 95% CI 0.2-0.9) or inconsistent HPV status (13.1 months; HR = 0.2, 95% CI 0.1-0.6). Regression of flat penile lesions is HPV-dependent and accelerated by condom use. This effect is probably the result of blocking viral transmission between sexual partners.     

K-ras oncogene mutations in sporadic colorectal cancer in The Netherlands Cohort Study

Activation of K-ras oncogene has been implicated in colorectal carcinogenesis, being mutated in 30-60% of the adenocarcinomas. In this study, 737 incident colorectal cancer (CRC) patients, originating from 120 852 men and women (55-69 years at baseline) participating in the Netherlands Cohort Study (NLCS), were studied in order to evaluate subgroups with respect to K-ras mutation status. Mutation analysis of the exon 1 fragment of the K-ras oncogene, spanning codons 8-29, was performed on archival colorectal adenocarcinoma samples of all patients using macrodissection, nested PCR and direct sequencing of purified fragments. The method of mutation detection was validated by the confirmation of reported K-ras status in CRC cell lines, a good correlation between fresh-frozen and routinely fixed, paraffin-embedded tissue, a detection limit of 5% mutated DNA and a good reproducibility. Various types of K-ras mutations were evaluated with respect to tumour sub-localization, Dukes' stage and tumour differentiation. In 37% (271/737) of the patients, the exon 1 fragment of K-ras gene was found to be mutated. The predominant mutations are G>A transitions and G>T transversions, and codons 12 and 13 are the most frequently affected codons. Patients with a rectal tumour were found to have the highest frequency of G>T transversions as compared with patients with a colon or rectosigmoid tumour. This difference appeared to be confined to women with a rectal tumour harbouring G>T transversions. No significant differences were observed for Dukes' stage with respect to types of K-ras mutation, which does not support direct involvement of the K-ras oncogene in adenocarcinoma progression. The equal distribution of K-ras mutations among cases with or without a family history of colorectal cancer argues against an important role for this mutation in familial colorectal cancer, and could imply that K-ras mutations are more probably involved in environmental mechanisms of colorectal carcinogenesis.     

Simultaneous detection of apoptosis and proliferation in colorectal carcinoma by multiparameter flow cytometry allows separation of high and low-turnover tumors with distinct clinical outcome

BACKGROUND: Dukes C colorectal carcinoma is treated with adjuvant chemotherapy. Adjuvant treatment is not standard for patients with Dukes B tumors, even though about 20% of patients within this tumor stage die of recurrent disease. The authors investigated whether a novel method of simultaneous detection of apoptosis and proliferation would improve the assessment of prognosis in colorectal carcinoma patients, with the ultimate goal of accurately identifying patients eligible for adjuvant therapy. METHODS: A multiparameter flow cytometric assay with heat pretreatment was performed on 278 paraffin-embedded colorectal adenocarcinomas. After immunochemical isolation of tumor cells, apoptosis and proliferation were assessed simultaneously by immunostaining for the M30 antibody and by quantitative DNA analysis, respectively. Patients were followed for more than 10 years. RESULTS: The mean values of apoptosis (apoptotic fraction [AF], i.e., the percentage of M30-positive cells) and proliferation (S-phase fraction [SPF]) were 11.1% and 13.1%, respectively. The AF and SPF values were correlated positively (P = 0.01) and both increased with advancing tumor stage (P = 0.02). Combining AF and SPF, patients with tumors with a high turnover (i.e., both AF and SPF values were greater than the mean) had an overall survival rate of 13%, whereas patients with low-turnover tumors (i.e., both AF and SPF values were less than the mean) had an overall survival rate of 89% (P < 0.001 by log rank test). Moreover, within Dukes B and C stages, patients with high-turnover tumors had a poorer survival than patients with low-turnover tumors (P < 0.001 for both stages). CONCLUSIONS: The simultaneous detection of apoptosis and proliferation in archival material allows separation of high and low-turnover colorectal adenocarcinomas and improves the assessment of prognosis. This technique could be used to stratify patients for adjuvant chemotherapy.     

Moyamoya and extracranial vascular involvement: fibromuscular dysplasia? A report of two children

We present two patients with moyamoya syndrome and the unusual involvement of extracranial vessels. The first case illustrates the rare association between moyamoya and primary pulmonary hypertension. In the second patient, moyamoya was complicated by stenoses of vertebral, renal, and mesenteric arteries. In both cases, a systemic intima-proliferative disease, such as fibromuscular dysplasia (FMD), was suspected to be the cause of both intracranial and extracranial arterial disease.     

Application of a Combined “Effect Compartment/Indirect Response Model” to the Central Nervous System Effects of Tiagabine in the Rat

Pharmacological inhibition of GABA uptake transporters provides a mechanism for increasing GABAergic transmission, which may be useful in the treatment of various neurological disorders. The purpose of our investigations was to develop an integrated pharmacokinetic–pharmacodynamic (PK/PD) model for the characterization of the pharmacological effect of tiagabine, R-N-(4,4-di-(3-methylthien-2-yl)but-3-enyl)nipecotic acid, in individual rats in vivo. The tiagabine-induced increase in the amplitude of the EEG 11.5–30 Hz frequency band (), was used as pharmacodynamic endpoint. Chronically instrumented male Wistar rats were randomly allocated to four groups which received an infusion of 3, 10, or 30 mg kg ^–1 ml min ^-1 kg^–1, 1.50.1 L kg^–1 and 200.2 min.A time delay was observed between the occurrence of maximum plasma drug concentrations and maximal response. A physiological PK/PD model has been used to account for this time delay, in which a biophase was postulated to account for tiagabine available to the GABA uptake carriers in the synaptic cleft and the increase in EEG effect was considered an indirect response due to inhibition of GABA uptake carriers. The population values for the pharmacodynamic parameters characterizing the delay in pharmacological response relative to plasma concentrations were k_eo=0.030 min ^–1 and k_out=81 min^–1, respectively. Because of the large difference in these values the PK/PD model was simplified to the effect compartment model. Population estimates were E₀=155 6 V, E_max=100 5 V, EC₅₀=287 7 ng ml^–1, Hill factor=1.8 0.2 and k_eo=0.030 0.002 min ^–1. The results of this analysis show that for tiagabine the combined effect compartment-indirect response model can be simplified to the classical effect compartment model.     

Informing the Patient With Fatal Illness

A physician has neither the right nor the obligation to impose on a patient factual evidence which serves no therapeutic purpose. The handing down of a medical death sentence can severely demoralize a patient who inwardly realizes the true situation but prefers to proceed on a basis of tacit communication.