Comparison of novel synthetic peptide-based DETECT-RUBELLA enzyme immunoassays with Enzygnost and IMx for detection of rubella-specific immunoglobulin G.

Enzyme immunoassays (EIAs) using synthetic peptides SP-E1 and SP-E1E2 (DETECT-RUBELLA [Bio-Chem]) were compared with two viral lysate-based EIAs (Enzygnost [Behring] and IMx [Abbott]) for the detection of rubella virus-specific immunoglobulin G antibodies. Sensitivities of 94.7, 100, 98.6, and 100% and specificities of 100, 97.4, 100, and 73.7% were found for the SP-E1, SP-E1E2, Enzygnost, and IMx EIAs, respectively.     

Effect of delayed specimen processing on cytomegalovirus antigenemia test results.

Blood samples held at either 4 degrees C or room temperature for 1 day had similar mean decreases in number of cytomegalovirus antigenemia-positive cells (52 to 55%) and similar false-negative test results (13 to 14%). After 2 days, samples held at 4 degrees C showed no further decline, whereas samples held at room temperature had a mean 81% decrease in positive cells, a 32% false-negative rate, and a more marked deterioration in cell morphology.     

A controlled trial comparing foscarnet with vidarabine for acyclovir-resistant mucocutaneous herpes simplex in the acquired immunodeficiency syndrome. The AIDS Clinical Trials Group.

BACKGROUND AND METHODS. Most strains of herpes simplex virus that are resistant to acyclovir are susceptible in vitro to both foscarnet and vidarabine. We conducted a randomized trial to compare foscarnet with vidarabine in 14 patients with the acquired immunodeficiency syndrome (AIDS) and mucocutaneous herpetic lesions that had been unresponsive to intravenous therapy with acyclovir for a minimum of 10 days. The patients were randomly assigned to receive either foscarnet (40 mg per kilogram of body weight intravenously every 8 hours) or vidarabine (15 mg per kilogram per day intravenously) for 10 to 42 days. In the isolates of herpes simplex virus we documented in vitro resistance to acyclovir and susceptibility to foscarnet and vidarabine. RESULTS. The lesions in all eight patients assigned to foscarnet healed completely after 10 to 24 days of therapy. In contrast, vidarabine was discontinued because of failure in all six patients assigned to receive it. The time to complete healing (P = 0.01), time to 50 percent reductions in the size of the lesions (P = 0.01) and the pain score (P = 0.004), and time to the end of viral shedding (P = 0.006) were all significantly shorter in the patients assigned to foscarnet. Three patients had new neurologic abnormalities while receiving vidarabine. No patient discontinued foscarnet because of toxicity. Although initial recurrences of herpes simplex infection after the index lesion had healed tended to be susceptible to acyclovir, acyclovir-resistant infection eventually recurred in every healed patient, a median of 42.5 days (range, 14 to 191) after foscarnet was discontinued. CONCLUSIONS. For the treatment of acyclovir-resistant herpes simplex infection in patients with AIDS, foscarnet has superior efficacy and less frequent serious toxicity than vidarabine. Once the treatment is stopped, however; there is a high frequency of relapse.     

Genetic linkage of the tricho-dento-osseous syndrome to chromosome 17q21

Tricho-dento-osseous syndrome (TDO), MIM# 190320, is transmitted as a highly penetrant autosomal dominant trait that is characterized by variable clinical expression. The principal clinical features include kinky/curly hair in infancy, enamel hypoplasia, taurodontism, as well as increased thickness and density of cranial bones. Possible genetic linkage has been reported for TDO with the ABO blood group locus, but the gene defect remains unknown. We have identified four multiplex families (n = 63, 39 affected, 24 unaffected) from North Carolina segregating TDO. We previously have excluded a major locus for TDO in the ABO region for these families. Utilizing a genome-wide search strategy, we obtained conclusive evidence for linkage of the TDO syndrome locus to markers on chromosome 17q21 (D17S791, Z max = 10.54, Theta = 0.00) with no indication of genetic heterogeneity. Multipoint analysis suggests the TDO locus is located in a 7 cM chromosomal segment flanked by D17S932 and D17S941. This finding represents the first step towards isolation and cloning of the TDO gene. Identification of this gene has important implications for understanding normal and abnormal craniofacial development of hair, teeth and bone.      

The major peanut allergen,Ara h 2, functions as a trypsin inhibitor,and roasting enhances this function

BACKGROUND: The widespread use of peanut products, the severity of the symptoms, and its persistence in afflicted individuals has made peanut allergy a major health concern in western countries such as the United States, United Kingdom, and Canada. In a previous study, the authors showed that the allergenic properties of peanut proteins are enhanced as a result of thermal processing. OBJECTIVE: The purpose of this investigation was to determine whether any specific functions are associated with the major peanut allergen, Ara h 2, and whether the functionality of this protein is influenced by processing. An assay was developed and used to assess structure/function changes in Ara h 2 induced by roasting and the effect of these alterations on the allergenic properties of this major peanut allergen. METHODS: A protein domain homology search was used to determine possible functions for Ara h 2. One of the putative functions (protease inhibition) was tested by means of appropriate enzyme assays and protein gel electrophoresis. Circular dichroism was used to compare the structural properties of Ara h 2 purified from raw and roasted peanuts. RESULTS: Ara h 2 purified from peanuts is homologous to and functions as a trypsin inhibitor. Roasting caused a 3.6-fold increase in trypsin inhibitory activity. Functional and structural comparison of the Ara h 2 purified from roasted peanuts to native and reduced Ara h 2 from raw peanuts revealed that the roasted Ara h 2 mimics the behavior of native Ara h 2 in a partially reduced form. CONCLUSIONS: The data indicate that thermal processing might play an important role in enhancing the allergenic properties of peanuts. Not only has it previously been shown to affect the structural and allergic properties of peanut proteins but also, for the first time, the functional characteristics of an allergen. These structural and functional alterations are likely to influence the allergenicity of peanuts.     

Dynamic balance of metabotropic inputs causes dorsal horn neurons to switch functional states

Sensory relay structures in the spinal cord dorsal horn are now thought to be active processing structures that function before supraspinal sensory integration. Dorsal horn neurons directly receive nociceptive (pain) signals from the periphery, express a high degree of functional plasticity and are involved in long-term sensitization and chronic pain. We show here that deep dorsal horn neurons (DHNs) in Wistar rats can switch their intrinsic firing properties from tonic to plateau or endogenous bursting patterns, depending upon the balance of control by metabotropic glutamate (mGlu) and GABA(B) receptors. We further show that this modulation acts on at least one common target, the inwardly rectifying potassium channel (Kir3). Finally, we found that these firing modes correspond to specific functional states of information transfer in which dorsal horn neurons can faithfully transmit, greatly enhance or block the transfer of nociceptive information.     

Real-time nucleic acid sequence-based amplification using molecular beacons for detection of enterovirus RNA in clinical specimens

Real-time nucleic acid sequence-based amplification (NASBA) using molecular beacon technology (NASBA-beacon) was compared to standard NASBA with postamplification hybridization using electrochemiluminescently labeled probes (NASBA-ECL) for detection of enteroviruses (EV) in 133 cerebrospinal fluid and 27 stool samples. NASBA-ECL and NASBA-beacon were similar in sensitivity, detecting 55 (100%) and 52 (94.5%) EV-positive samples, respectively. There were no false positives. Both NASBA assays were significantly more sensitive than culture. Real-time NASBA-beacon reagents and equipment rental were more expensive than those for NASBA-ECL; however, time to result was shortened by 1.5 h, hands-on time was reduced by 25 min, and the assay was much simpler for technologists to learn and perform.