Assessment of HIV-1 entry inhibitors by MLV/HIV-1 pseudotyped vectors

Background  

Murine leukemia virus (MLV) vector particles can be pseudotyped with a truncated variant of the human immunodeficiency virus type 1 (HIV-1) envelope protein (Env) and selectively target gene transfer to human cells expressing both CD4 and an appropriate co-receptor. Vector transduction mimics the HIV-1 entry process and is therefore a safe tool to study HIV-1 entry.     

A practical approach to interpretation of corneal specimens

Corneal specimens form only a small part of the routine practice for most histopathologists but their assessment often requires considerable effort and specialized knowledge. The most common corneal specimens, full-thickness corneal discs and corneal biopsies, are discussed in this review. Corneal discs removed at keratoplasty are non-urgent specimens, as definitive treatment has already been undertaken, and while the pathologic diagnosis may change the prognosis for the graft, it rarely affects immediate treatment. Accurate diagnosis is still important, and will affect counseling of the patient, but referral to a colleague with a special interest is possible if necessary. Conversely, small partial-thickness corneal biopsies, which are mostly undertaken for culture negative keratitis with underlying suspected infection, are very urgent. Infectious keratitis can follow an extremely aggressive course, resulting in destruction of the cornea within hours. Accurate diagnosis is imperative. Due to the urgency of such specimens and the importance of diagnosis for immediate treatment, referral is not usually possible. It is the role of the pathologist to make optimal use of a small specimen to reach the relevant diagnosis in the minimum space of time.     

Association of ulcerative colitis with the inflammatory bowel disease susceptibility locus IBD2 in non-Jewish Caucasians and evidence of genetic heterogeneity among racial and ethnic populations with Crohn disease

Genomewide scanning has been used to identify chromosomal regions encoding susceptibility loci to inflammatory bowel disease (IBD). The greatest evidence for linkage to IBD has been reported for a region of chromosome 12q14 surrounding the microsatellite marker D12S83, with a logarithm of odds score of 5.47 and a positive transmission disequilibrium test, and which was subsequently named IBD2. We wished to confirm this locus by genotyping the highly polymorphic microsatellites D12S1022, D12S1056, and D12S83, spanning a continuous region on chromosome 12 of 342 kb, in a cohort of nonrelated individuals with ulcerative colitis (89 patients), Crohn disease (121 patients), and population-based control subjects (100 patients). In non-Jewish Caucasians, one D12S1022 allele, one D12S1056 genotype, and three D12S83 alleles were found to have statistically significant differences in distribution between the two disease groups and the control population. These data support a significant association of IBD with the IBD2 locus in close vicinity to the three markers studied. The replication of genetic risk loci in a case control association study may indicate susceptibility genes in this region and may facilitate identification of candidate genes for IBD. Subgroup analysis revealed a notable difference in genotype distribution among Jewish Caucasian and African American patients affected with Crohn disease when compared with similarly affected non-Jewish Caucasians. Using Fisher exact test, statistically significant distribution differences were observed for D12S1022 and D12S83. These data indicate that there may be significant genetic heterogeneity between different ethnic and racial IBD populations or may simply reflect differences in marker allele frequencies among populations.     

Childhood adversities as risk factors for alexithymia and other aspects of affect dysregulation in adulthood

BACKGROUND: Affect regulation is assumed to be a biologically based function that can become disrupted by inadequate parenting and by traumatic experiences. We studied the relation between the perceived parental parenting style, and sexual and physical abuse, with alexithymia, dissociation, anxiety and depression. METHODS: In a cross-sectional study psychiatric outpatients were administered a structured interview on childhood physical and sexual abuse and they completed a number of questionnaires about the parenting styles of their parents, and about alexithymia, dissociation and mood pathology. RESULTS: Maternal and paternal parenting styles were moderately correlated with alexithymia and depression. The paternal parenting style was also correlated with dissociation. Optimal parenting of one of the parents had a buffering effect on the degree of alexithymia, but not on the severity of other forms of affect dysregulation. The effect of sexual or physical abuse did not add to that of parental parenting style in terms of predicting affect dysregulation. However, a positively perceived maternal parenting style was found to have a buffering effect in terms of the degree of alexithymia, if sexual abuse had also taken place. CONCLUSIONS: Perceived parenting does appear to be of some significance in the development of alexithymia. Optimal parenting of one of the parents may protect against the development of alexithymia when the parenting of the other parent is perceived as non-optimal. However, it is likely that other factors besides parental care and sexual or physical abuse play an important role in the development of an adequate affect regulation.     

Clinical effectiveness of a mite allergen-impermeable bed-covering system in asthmatic mite-sensitive patients

BACKGROUND: Exposure to allergens plays a role in the development of bronchial hyperresponsiveness and in the chronic inflammatory response seen in asthmatic patients. House dust mites (HDMs) are an important source of allergen. Reduction of these allergens might lead to better lung function and reduction of asthma symptoms. OBJECTIVE: The effect of HDM-impermeable covers on HDM allergen levels, peak flow values, and asthma symptoms were measured. Therefore a randomized clinical trial was carried out. METHODS: Fifty-two allergic asthmatic patients were randomly allocated to use the HDM-impermeable or placebo covers. During the study period, daily peak flow and asthma symptom scores were recorded. Dust samples were taken from the mattresses. RESULTS: We observed a significant reduction in HDM allergen levels on the mattresses after encasing them with HDM-impermeable covers (reduction of 87% of Der p 1 in micrograms per gram of dust; P <.001). Baseline symptoms were so low that no improvement could be established. Morning peak expiratory flow is significantly higher in the intervention group compared with that seen in the placebo group during the study period (beta=20.2; P <.01). CONCLUSIONS: HDM-impermeable covers significantly decreased the level of HDM allergens. Furthermore, morning peak flow was significantly increased during the intervention period. This study indicates that HDM allergen-avoidance measures might have beneficial effects on allergen reduction and asthma outcome.     

Sensory stimulation reduces seizure severity but not afterdischarge duration of partial seizures kindled in the hippocampus at threshold intensities

Epilepsy is a family of neurological disorders that result in seizure activity that is characterized by transient hypersynchronous activation of a large population of neurons. In animal models, focal tetanic electrical stimulation of sufficient duration and intensity, can elicit epileptiform activity, that if repeated results in progressive intensification of seizure activity known as kindling. Kindling serves as a model of partial as well as secondarily generalized temporal lobe epilepsy. We utilized hippocampal kindling to provide a means of evaluating the effect of sensory stimulation on the duration and severity of the induced seizure activity. Sensory stimuli targeted either the olfactory, auditory or somatosensory systems in an attempt to retard or suppress seizure activity. To that end, rats were chronically implanted with electrodes in the CA1 region of dorsal hippocampus and kindled once daily until the seizure behaviour was fully generalized. Kindling stimulation consisted of daily application of 1-s trains of biphasic square wave pulses applied at a frequency of 60Hz, at the afterdischarge (AD) threshold. Sensory stimulation was applied 6-8s after the kindling stimulation every third day. One group of rats received a different sensory stimulus (novel) every third day, while another group was presented with the same sensory stimulus (repeated) every third day. Kindling stimulation applied to the dorsal hippocampus resulted in progression of the AD characteristics and seizure behavior, which typically developed very slowly in the early stages. The application of both the novel and repeated sensory stimulation during partial seizures (stages 1 and 2) resulted in a reduction in the seizure severity but not in the afterdischarge duration. Sensory stimulation delivered during secondarily generalized seizures (stages 4 and 5) failed to affect either parameter.     

The spectrum of aldolase B (ALDOB) mutations and the prevalence of hereditary fructose intolerance in Central Europe

We investigated the molecular basis of hereditary fructose intolerance (HFI) in 80 patients from 72 families by means of a PCR-based mutation screening strategy, consisting of heteroduplex analysis, restriction enzyme digest, DNA single strand electrophoresis, and direct sequencing. For a subset of patients mutation screening with DHPLC was established which turned out to be as fast and as sensitive as the more conventional methods. Fifteen different mutations of the aldolase B (ALDOB) gene were identified in HFI patients. As in smaller previous studies, p.A150P (65%), p.A175D (11%) and p.N335K (8%) were the most common mutated alleles, followed by c.360_363delCAAA, p.R60X, p.Y204X, and c.865delC. Eight novel mutations were identified in eight families with HFI: a small indel mutation (c.1044_1049delTTCTGGinsACACT), two small deletions (c.345_372del28; c.841_842delAC), two splice site mutations (c.113-1G>A, c.799+2T>A), one nonsense mutation (c.612T>G (p.Y204X)), and two missense mutations (c.532T>C (p.C178R), c.851T>C (p.L284P)). By mutation screening for the three most common ALDOB mutations by DHPLC in 2,000 randomly selected newborns we detected 21 heterozygotes. Based on these data and after correction for less common and private ALDOB mutations, HFI prevalence in central Europe is estimated to be 1:26,100 (95% confidence interval 1: 12,600-79,000).     

Delayed-type hypersensitivity reaction to paraphenylenediamine is mediated by 2 different pathways of antigen recognition by specific alphabeta human T-cell clones

BACKGROUND: Allergic contact dermatitis to paraphenylenediamine (PPD) is a frequent cause of morbidity and occupational disability. OBJECTIVE: The aim of the study was to characterize T-cell responses to PPD and Bandrowski's base (BB), an autoxidation product of PPD, by using polyclonal and monoclonal T-lymphocyte cultures. METHODS: PPD- and BB-driven proliferation of PBMCs and T-cell clones (TCCs) was assessed by means of tritiated thymidine incorporation. Surface markers were studied by means of flow cytometry, and cytokine generation was assessed with an ELISA. RESULTS: TCCs, with one exception, were CD4+/CD45RO+, and T-cell receptors were alphabeta+. Three of 6 TCCs expressed Vbeta 16. TCC stimulation was HLA-DP restricted, and TCCs secreted IL-4, IL-5, and marginal levels of IFN-gamma. TCCs reacted to both PPD and BB. Presentation of BB to TCCs was dependent on viable antigen-presenting cells (APCs) pulsed for 4 hours, and fixed APCs failed to stimulate TCCs. Moreover, polyclonal responses to BB were enhanced by metabolically active enzymes, such as cytochrome P450 enzymes. BB has to be metabolized and processed. In contrast, fixation of APCs did not impair their ability to present PPD to TCC, whereas pulsing of APCs with PPD failed to stimulate TCCs. Thus PPD had to be present during the process, and polyclonal stimulation was not enhanced by cytochromes. CONCLUSION: These results suggest that PPD itself can be recognized by T cells through a processing-independent pathway, whereas its autoxidation product, BB, required processing and possibly metabolism to stimulate the same TCC. Our data demonstrate that 2 distinct pathways of antigen presentation to activate specific TCCs are involved in the immune response to PPD.