Immune response in urinary tract infection determined by radioimmunoassay and immunofluorescence: serum antibody levels against infecting bacterium and Enterobacteriaceae common antigen.

A solid-phase radioimmunoassay (RIA) procedure was compared with the indirect fluorescent antibody (IFA) test in a serological study of 76 female adults with urinary tract infections. Relative serum antibody activity was determined against patients' homologous infecting enterobacteria by RIA and IFA and against heterologous enterobacterial common antigen (Escherichia coli O14) by RIA. There was marked correlation between results of the IFA and RIA methods using the homologous system; 22 of 51 patients (43%) with pyelonephritis had significantly elevated serum antibody activity by both IFA (titers greater than or equal to 512) and RIA (binding ratio greater than or equal to 2.0) when compared with normal serum controls; three had significant antibody activity detectable by RIA only. Eighteen (72%) of 25 patients with pyelonephritis had RIA binding ratios of greater than or equal to 2.0 against their homologous bacterial isolates and the enterobacterial common antigen; an additional 6 patients had binding ratios of greater than or equal to 2.0 against the antigen only. All 25 patients with cystitis had low serum antibody levels by IFA and RIA when tested against their own isolate as well as enterobacterial common antigen. The RIA procedure was objective, quantitative, and less tedious to perform than IFA.     

THE INTERACTION OF RESPONSES IN THE BRAIN TO SEMANTIC STIMULI

Long time-constant EEG recording during paired stimuli has led to the discovery of the contingent negative variation or expectancy wave (Walter, 1964). This effect is produced when a conditional stimulus signals that an imperative stimulus demanding action, decision, or attention will follow at a short, constant time interval. Symbolic and meaningful stimuli were presented to subjects tachistoscopically, and the evoked responses in the brain were electronically averaged. The cerebral evoked responses to such psychological stimuli are more complex than to flashes. A slow negative DC potential shift (CNV) was seen during the interval between an auditory ready signal and the visual exposure if recognition of the stimulus was required, or if it was interesting. Following the visual exposure, a slow positive DC shift occurred. The method has been developed to study the brain responses to psychological stimuli. The amplitude of the responses relates to the information content and subjective factors rather than to the physical strength of the stimulus.     

Increased frequency of rheumatoid factor precursor B lymphocytes after immunization of normal adults with tetanus toxoid.

Vaccination of normal adults with tetanus toxoid induced a two-three-fold rise in the frequency of IgM anti-IgG (rheumatoid factor, RF) B lymphocytes inducible by the polyclonal B cell activator, Epstein-Barr virus. The increase in IgM-RF precursors occurred earlier, was greater in magnitude, and was more sustained than the change in plasma IgM-RF. It was associated with a rise in total IgM levels, and correlated positively with the magnitude of the IgG anti-tetanus antibody response, but not with levels of circulating immune complexes. The ability of apparently innocuous infections and immunizations to increase the frequency of IgM-RF precursor B lymphocytes may be the reason for the previously noted expansion in this autoreactive B cell pool between birth and adulthood.     

Intertubular growth in pure seminomas: associations with poor prognostic parameters

Clinical stage I seminomas are effectively treated with surgery raising concerns as to when to give adjuvant radiation therapy given the risk of secondary malignancies. A recent randomized trial found tumor size and rete testis invasion to be the strongest predictors of relapse in clinical stage I seminomas. These 2 parameters may be surrogate measures of tumor volume. Intertubular seminoma (ITS) of the testis describes the presence of neoplastic germ cells within the interstitium of the testis. These cells are detected away from the main macroscopic mass. Because ITS can infiltrate in a 3-dimensional fashion, it may also represent a measure of tumor volume not usually noted in standard pathology reporting. The goal of this study was to determine the incidence of ITS in pure seminomas and its association with other prognostic parameters. One hundred twenty consecutive pure seminomas surgically removed between 1998 and 2003 were evaluated. ITS was defined as the presence of an interstitial or intertubular growth pattern of tumor cells, which was noncontiguous with the main tumor and present at least 3 high-power fields away from the tumor mass. The average tumor size was 3.4 cm. Of the entire cohort of patients, which included pathological stages T1 through T3, 11% had invasion through the tunica albuginea, 51% had rete testis invasion, 51% had lymphovascular invasion, 93% had associated intratubular germ-cell neoplasia, and 36% had ITS. ITS was significantly associated with rete testis invasion ( P = .001). Logistic regression analysis looking at ITS, tumor size, patient age, and lymphovascular invasion revealed that only ITS was associated with rete testis invasion (RR, 4.1, P < .0001). ITS is present in a significant proportion of pure seminomas and has a significant association with rete testis invasion. The presence of ITS may therefore be an important prognostic factor, not only because it alters the calculated size of the tumor but also because it has an association with rete testis invasion.     

Sensation Seeking and Cortical Augmenting-Reducing

The experiment was designed to establish the relationship between the Sensation Seeking Scales (SSS) and cortical augmenting-reducing. Forty-nine male undergraduate Ss were used. Ss were presented with five intensities of light flashes in randomly presented blocks of trials at each intensity. Averaged evoked response (AER) amplitudes were measured at each intensity of light. Augmenting-reducing was measured for each S as the slope of the relationship between stimulus intensity and amplitude of response. This slope measure correlated very significantly (r= .59) with the Disinhibition subscale of the SSS and positively, but not significantly, with other subscales. Comparing the low and high scorers on the Disinhibition scale, a significant interaction between groups and stimulus intensities was found but no main effects of stimulus intensity or groups were found. The high Disinhibitors did not differ from the lows at the low stimulus intensities but did differ significantly at the highest intensity where the lows showed a marked reducing tendency. The results show an interesting convergence between the Disinhibition type of sensation seeking, manic tendencies, and the AER.     

Latex specific IgE: performance characteristics of the IMMULITE 2000 3gAllergy assay compared with skin testing.

BACKGROUND: In the absence of a US Food and Drug Administration (FDA)-cleared latex skin testing reagent, in vitro tests remain important for the diagnosis of latex allergy. OBJECTIVE: To evaluate the performance characteristics of IMMULITE 2000 3gAllergy (Immulite), a third-generation, FDA-cleared, continuous random-access immunoanalyzer, for the quantification of latex specific IgE. METHODS: Stored serum samples (N = 201) from patients classified as having positive or negative latex puncture skin test results were measured for latex specific IgE levels using Immulite, and these data were compared with historical results from 3 second-generation, FDA-cleared IgE antilatex assays (AlaSTAT [Ala], AutoCAP [CAP], and HY*TEC enzyme immunoassay [HT]). RESULTS: The diagnostic performances of the CAP, Ala, and Immulite assays (> or = 0.35 kU/L cutoff value) were equivalent in sensitivity and specificity (P > .05). The HT assay (> or = 0.05 kU/L cutoff value) was more sensitive and less specific (P < .05). Immulite (> or = 0.10 kU/L cutoff value) had greater sensitivity than Ala and CAP and greater specificity than HT (P < .05 for both). Diagnostic efficiency was greater for Immulite than for CAP, Ala, and HT (P < .05). CONCLUSIONS: The Immulite system is superior in diagnostic performance, especially at the 0.10 kU/L or greater cutoff level, for the diagnosis of latex allergy compared with older, second-generation assays. Immulite still misclassifies 15.5% of puncture skin test-positive individuals as negative for latex specific IgE. Compared with second-generation assays, Immulite represents a technological advance, with enhanced speed and less operator intervention.     

The CARD15 2936insC mutation and TLR4 896 A>G polymorphism in African Americans and risk of preterm premature rupture of membranes (PPROM)

Infection is believed to be a leading cause of preterm premature rupture of membranes (PPROM). The bacterial cell wall component, lipopolysaccharide (LPS), is thought to initiate tissue responses leading to PPROM in the setting of Gram negative infection. LPS is recognized by the innate immune system, including the proteins encoded by the CARD15 and TLR4 genes. A recently described mutation (2936insC) in CARD15 and a polymorphism in TLR4 896 A>G impair responses to LPS. The objective of this study was to determine if African Americans, who have a higher incidence of PPROM than Caucasians, have different frequencies of the mutant CARD15 allele and the TLR4 hyporesponsive variant, and if risk of PPROM is influenced by fetal carriage of these alleles. The allele frequencies for the CARD15 mutation and the TLR4 896G variant in African Americans were similar to those reported for Caucasians. There was no association between the TLR4 alleles examined and PPROM. However, the CARD15 mutation was only detected in controls and not in PPROM cases. We conclude that the CARD15 mutation and hyporesponsive TLR4 allele do not contribute to ethnic variation in the incidence of PPROM.     

Changes in muscle recruitment patterns during skill acquisition

The control of movement is predicated upon a system of constraints of musculoskeletal and neural origin. The focus of the present study was upon the manner in which such constraints are adapted or superseded during the acquisition of motor skill. Individuals participated in five experimental sessions, in which they attempted to produce abduction-adduction movements of the index finger in time with an auditory metronome. During each trial, the metronome frequency was increased in eight steps from an individually determined base frequency. Electromyographic (EMG) activity was recorded from first dorsal interosseous (FDI), first volar interosseous (FVI), flexor digitorum superficialis (FDS), and extensor digitorum communis (EDC) muscles. The movements produced on the final day of acquisition more accurately matched the required profile, and exhibited greater spatial and temporal stability, than those generated during initial performance. In the early stages of skill acquisition, an alternating pattern of activation in FDI and FVI was maintained, even at the highest frequencies. In contrast, as the frequency of movement was increased, activity in FDS and EDC was either tonic or intermittent. As learning proceeded, alterations in recruitment patterns were expressed primarily in the extrinsic muscles (EDC and FDS). These changes took the form of increases in the postural role of these muscles, shifts to phasic patterns of activation, or selective disengagement of these muscles. These findings suggest that there is considerable flexibility in the composition of muscle synergies, which is exploited by individuals during the acquisition of coordination.     

Use of HLA marker associations and HLA haplotype linkage to estimate disease risks in families with gluten-sensitive enteropathy

Based on a two-locus, double recessive model, we derive formulas for the risks that relatives of individuals with gluten-sensitive enteropathy (GSE) will also develop the disease. The calculations take advantage of: the linkage between the HLA locus and one of the two proposed GSE loci, and the preferential association of the HLA-DR3 and DR7 alleles with the GSE disease allele that occupies the HLA-linked locus. We use Bayes' rule to quantitate the strength of the association between the GSE disease allele and the HLA marker allele. This method predicts that siblings of the proband have an overall 10% risk for GSE, which is consistent with observed family data. This predicted risk rises to 30% when siblings are HLA-identical to the proband (also consistent with observed data) or when the sibling has the DR3 allele in the HLA haplotypes not shared with the proband. In those populations where DR7 also is associated with GSE, siblings of probands have a 10% predicted risk for GSE when only one HLA haplotype is shared with the proband and DR7 is included in the unshared haplotype. Other DR alleles are associated with much lower disease risks. By separating individuals into high and low risk groups, HLA typing identifies those individuals who would benefit from further diagnostic procedures. This general strategy should be applicable to other multilocus, marker-associated diseases.