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J J Ryan

Publications and source records attributed to J J Ryan.

At least 163 records · Page 9Linked to original sources
PubMed1987

The Mlsd-defined primary mixed lymphocyte reaction: a composite response to Mlsa and Mlsc determinants.

Considerable disagreement exists among immunologists regarding the polymorphic nature of the murine Mls system. An estimate of the capacity of a given putative Mls allelic gene product expressed on a stimulator population to elicit proliferation of H-2-compatible Mls-disparate unprimed T cells may vary widely among different groups of investigators. This laboratory has shown previously that preactivation of B lymphocytes in a splenocyte stimulator population by exposure to goat anti-mouse IgD (GaMD) before irradiation dramatically enhanced the in vitro presentation not only of the strongly stimulatory (and highly cross-reactive) Mlsa and Mlsd, but also the more poorly stimulatory Mlsc specificity. Therefore, by the use of GaMD-treated splenocytes that optimally present the various Mls non-H-2 stimulatory epitopes, we attempted in this study to obtain a clearer understanding of Mls polymorphism by re-examining the conflicting claims associated with the mixed lymphocyte reaction (MLR) stimulatory capacity of different Mls specificities. Among H-2k responder cells of the Mls null, Mlsa, Mlsb, or Mlsd genotypes, only T cells from Mlsd-bearing CBA/J mice did not respond to Mlsc determinants present on GaMD-treated C3H/HeJ stimulator cells. Crossing CBA/J with an Mlsc-responsive mouse strain yielded an F1 animal in which nonresponsiveness to Mlsc was dominant. Although Mlsa (AKR/J) and Mlsc (C3H/HeJ) parental T cells both proliferated vigorously to Mlsd (CBA/J) stimulator cells, the Mlsa/c (AKR X C3H)F1 T cells responded poorly to GaMD-treated Mlsd stimulator cells. In addition, Mlsd (CBA/J) T cells were nonresponsive to Mlsa (AKR/J), Mlsc (C3H/HeJ), and Mlsa/c (AKR X C3H)F1 GaMD-treated stimulator cells. Because Mlsa (AKR/J) and Mlsc (C3H/HeJ) specificities are mutually stimulatory, at least limited polymorphism must exist in the Mls system. However, because Mlsa/c (AKR X C3H) and Mlsd (CBA/J) specificities are mutually nonstimulatory, T cell proliferation in an Mlsd-defined primary MLR is most likely due to a composite response to Mlsa and Mlsc epitopes present on CBA/J stimulator cells.

Alleles↗
PubMed1987

Regulation of the in vitro presentation of minor lymphocyte stimulating determinants by major histocompatibility complex-encoded immune response genes.

Activation of murine B lymphocytes in a splenocyte stimulator population with affinity-purified goat anti-mouse IgD (G alpha M delta) antibody was previously shown by this laboratory to enhance the presentation of strongly stimulatory major histocompatibility complex (MHC) and minor lymphocyte-stimulating (Mlsa,d) determinants in a primary mixed lymphocyte reaction. In the present study, the G alpha M delta treatment of murine splenocytes was employed to enhance the detection of the weakly stimulatory non-MHC Mlsc determinant in order to study the role the MHC might play as a restricting element for the recognition of these minor antigens in a primary mixed lymphocyte reaction. Indeed, enhanced T cell proliferation to Mlsc determinants presented on G alpha M delta-treated splenocytes was observed when the responder and activated H-2-compatible stimulator cell shared certain MHC haplotypes. High responsiveness was associated with the H-2a,k,j,p haplotypes, intermediate responsiveness was associated with the H-2f,g haplotypes and low responsiveness was associated with the H-2b,s haplotypes. (Low X high responder)F1 T cells preferentially responded to the Mlsc determinants presented on G alpha M delta-treated stimulator cells of the F1 or parental high responder H-2 haplotype. When mitomycin C instead of irradiation was used to inactivate normal (non-IgD-treated) splenocytes, a similar preferential response of T cells to Mlsc determinants presented on stimulator cells of a high responder H-2 haplotype was also observed. The inability of G alpha M delta-treated splenocytes of the low responder haplotype to elicit substantial levels of T cell proliferation across an Mlsc difference could not be attributed to the failure of these stimulator cells to become activated by the anti-Ig antibody. In addition, co-culture experiments could not identify the poor T cell response to Mlsc determinants presented on certain MHC haplotypes as being caused by the induction of nonspecific suppressor cells. Presentation of Mlsc determinants caused by transgene product complementation was detectable in F1 mice derived by crossing one parent that had the Mlsc non-MHC genes and a poorly permissive H-2 haplotype with a parent that expressed a permissive H-2 haplotype but lacked the Mlsc non-MHC genes.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗
PubMed1987

Clonal analysis of the Mls system. A reappraisal of polymorphism and allelism among Mlsa, Mlsc, and Mlsd.

Only two sets of antigenic determinants are recognized by T lymphocytes at uniquely high precursor frequencies: those encoded by the MHC and those encoded by Mls. The structural as well as functional characteristics of MHC products have been extensively analyzed. In contrast, little information concerning the nature of Mls genes or their products is available. Although it was originally described (5, 6) that the Mls locus on chromosome 1 is composed of four alleles that encode polymorphic cell surface structures, the issues of polymorphism and allelism in the Mls system have been controversial for some time. In the present study, T cell clones were generated by continuous stimulation of B10.BR (H-2k, Mlsb) T cells by CBA/J (H-2k, Mlsd) stimulators and they were used to analyze the relationship of putative Mlsa, Mlsc, and Mlsd determinants. All clones proliferated in response to determinants expressed by CBA/J stimulators. In addition, each of these clones exhibited a second reactivity to either AKR/J (H-2k, Mlsa) or C3H/HeJ (H-2k, Mlsc) stimulators. No clone responded to both AKR/J and C3H/HeJ. These second specificities were defined to be for Mlsa or Mlsc determinants, respectively, by the response patterns of clones and unprimed T cells to stimulators derived from congenic strains, recombinant inbred (RI) strains, and backcross mice. Moreover, a segregation analysis of the (CBA/J X B10.BR)F1 X B10.BR backcross indicated that the Mlsa-like and Mlsc-like determinants expressed on CBA/J (Mlsd) cells are in fact encoded by nonallelic, unlinked genes. These findings suggest a new concept of the polymorphism and genetics of the Mls system. It is proposed that two distinct and nonallelic gene products express, respectively, the noncrossreacting Mlsa and Mlsc determinants, and that the Mlsd phenotype does not represent an independent genotype but rather reflects the concurrent expression of Mlsa and Mlsc. The Mls system, therefore, consists of at least two systems that are distinct both genetically and antigenically, and that may be of different biologic or physiologic significance as well.

Alleles↗
PubMed1987

T cell recognition of Mls. T cell clones demonstrate polymorphism between Mlsa, Mlsc, and Mlsd.

The determinants encoded by the minor lymphocyte stimulating locus (Mls) are defined as determinants that induce strong T cell proliferative responses in primary mixed lymphocyte reactions. Although the Mls locus was originally described as having four alleles, a, b, c, and d, a number of recent observations have led several investigators to challenge the idea that Mls is truly a polymorphic system. To better define this system of determinants recognized at high frequency by T cells, the present studies were undertaken to evaluate the polymorphism of Mls products. In the present study, the in vitro proliferative responses of Mlsa- and Mlsc-specific T cell clones were employed to analyze Mls products. The identification of determinants recognized by Mlsa- and Mlsc-reactive clones was established by the pattern of responses to stimulators derived from congenic strains, recombinant inbred strains, and backcross mice. T cell clones and unprimed T cells gave concordant responses that confirmed the Mlsa or Mlsc specificity of the cloned populations. With the use of these two sets of Mls-specific T cell clones, the existence or absence of polymorphism of Mls-encoded gene products was examined. It was found that Mlsa-specific cloned T cells responded to Mlsa but not Mlsc stimulators, whereas Mlsc-specific clones responded to Mlsc but not Mlsa. This reciprocal pattern of specificity indicates that the Mls system as currently defined is therefore truly polymorphic. In addition, it was observed that both Mlsa- and Mlsc-specific clones were stimulated by Mlsd stimulators. In particular, the possibility that Mlsa and Mlsc are not alleles but products of different loci and that Mlsd strains are those that express both Mlsa and Mlsc is considered.

Animals↗
PubMed1987

Effect of plate preincubation on Bacillus stearothermophilus disc assay zone diameters.

Effect of plate preincubation on the Bacillus stearothermophilus disc assay zone size was studied. Each of three raw milk samples were subdivided and treated with five levels of US Pharmacopeial reference standard penicillin G. Freshly prepared, 2.5- and 5-d old seeded disc assay culture plates were preincubated at 64 degrees C for 0 (control), 20, 40, 60, 80, 100, and 120 min prior to placement of discs on the medium surface. Plate age did not have a significant effect on the size of the zone diameter. Following 20 and 40 min of plate preincubation, zone diameters were in some, but not all, cases significantly different from the control. Plate preincubation of 60 min or greater always significantly decreased zone diameter. Routine preincubation of B. stearothermophilus plates is not recommended. In situations where time is a critical factor, plates should be preincubated no longer than 40 min.

Animals↗
PubMed1986

Factor analysis of the Wechsler Adult Intelligence Scale-Revised (WAIS-R) in a brain-damaged sample.

The Wechsler Adult Intelligence Scale-Revised (WAIS-R) was factor analyzed for a sample of 100 diagnostically heterogeneous brain-damaged patients. Subjects were from two VA Medical Centers located in the Midwest with means for age, education, and Full Scale IQ of 52.31 (SD = 14.41), 11.37 (SD = 2.57), and 86.72 (SD = 10.78), respectively. A principal factor analysis followed by Varimax rotation provided evidence for the existence of three factors underlying the WAIS-R (i.e., Performance, Verbal, and Freedom from Distractibility). The present results are consistent with earlier studies that employed the 1939 and 1955 versions of Wechsler's Adult Intelligence Scale with neurologically impaired subjects.

Adult↗
PubMed1986

Critical analysis of open peritoneal lavage in blunt abdominal trauma.

Using the generally accepted paracentesis and lavage criteria for laparotomy for patients with blunt abdominal trauma, we found an accuracy rate of 97 percent but a nontherapeutic laparotomy rate of 27 percent. The 17 percent true false-positive rate of paracentesis and lavage is much higher than has been previously appreciated.

Abdominal Injuries↗
PubMed1986

Alternate form reliability and equivalency of the Rey Auditory Verbal Learning Test.

Assessed alternate form reliability and equivalency for the Rey Auditory Verbal Learning Test (AVLT) in a clinical sample. A test-retest, counterbalanced design was utilized with a diagnostically heterogenous group of 85 VA Medical Center patients. The mean test-retest interval was 140 min. Alternate form reliability coefficients were highly significant, all p less than .001, and ranged from .60 to .77. The forms yielded comparable means with differences of less than 1 point on each of the five learning trails and the postinterference (VI) and recognition trials. Total words recalled on trials I through V differed by less than 3 points across forms. From a statistical point of view, when the alternate form was administered second it was slightly more difficult than the original. In the reverse order, the two measures were comparable. Overall, differences between forms lacked clinical significance and the tests were judged to be equivalent measures.

Adult↗
PubMed1986

Detection of penicillin, cephapirin, and cloxacillin in commingled raw milk by the Spot test.

The objective of this study was to compare Spot Test results with the results of the Bacillus stearothermophilus disc assay. Commingled raw milk samples were subdivided and spiked with penicillin, cephapirin, or cloxacillin. All subsamples, including unspiked subsamples, were analyzed by the Spot Test (3 or 9 replicates) and disc assay (9 replicates). Mean zone diameter for every subsample was calculated; subsamples having a mean zone diameter greater than or equal to 16 mm were considered positive. At penicillin concentrations less than or equal to 3.7 ng/ml, agreement between the Spot Test and disc assay was 83.4%, and false positive and negative percentages were 14.4 and 2.2%, respectively. Above 3.7 ng/ml, agreement was 100%. At cephapirin concentrations less than or equal to 12 ng/ml, agreement between the two tests was 67.9%, and false positive and negative percentages were 28.8 and 3.3%, respectively. Above 15 ng/ml, agreement was 99.3% with .7% false negatives. At cloxacillin concentrations less than or equal to 50 mg/ml agreement between the two tests was 54.5 with 45.5% false positives. At cloxacillin concentrations greater than or equal to 62.5 ng/ml, agreement between the two tests was 87.2% and false positive and negative percentages were 12.6 and .2%, respectively. In a field trial consisting of 823 bulk samples, Spot Test and disc assay agreement was 100%. The Spot Test is a rapid and reliable method for detecting penicillin, cephapirin, and cloxacillin residues in raw milk at concentrations that will produce a 16-mm zone.

Animals↗
PubMed1986

Validity and diagnostic accuracy of an alternate form of the Rey Auditory Verbal Learning Test.

The diagnostic validity of an alternate form of the Rey Auditory Verbal Learning Test (AVLT) is investigated. Subjects were 73 inpatients from a VA Medical Center who were classified as having either intact (n = 41) or impaired (n = 32) memory functions. Employing a counterbalanced design, both groups were administered the standard (Form A) and alternate (Form C) forms of the AVLT. Means for the learning trials, trial VI and the recognition procedure were calculated for the intact and memory-impaired subjects and contrasted for each test. Results suggested that Form C discriminated groups at a level comparable to that of Form A. This impression was confirmed by separate stepwise discriminant analyses for Form A and Form C that yielded identical hit-rates (i.e., 75.3%) in terms of identifying subjects as memory-intact or memory-impaired. These findings suggested that Form C may be used for the assessment of persons with verbal mnemonic deficits with the same degree of confidence that has been attributed to Form A.

Journal Article↗
PubMed1985

MCMI characteristics of DSM-III posttraumatic stress disorder in Vietnam veterans.

Compared the MCMI profiles of 25 veterans with a diagnosis of Posttraumatic Stress Disorder (PTSD) with those of 25 veterans carrying psychiatric disorders which typically cause problems in the differential diagnosis of PTSD. The PTSD group had higher elevations on nine of the 20 MCMI scales (all ps less than .05). Profiles were also significantly different in shape and scatter. A discriminant analysis accounted for 100% of the variance and correctly classified 88% of the patients. Resulting MCMI profiles appear to be consistent with DSM-III criteria for PTSD.

Combat Disorders↗
PubMed1985

Short-term memory and averaged evoked cortical potentials.

Cortical electrical activity reflected by changes in N1 and CNV evoked potentials was compared to performance on a battery of neuropsychological measures of attention and short-term memory. Results supported the hypothesis that N1 reflects the accuracy of the short term memory image. Attentional processes indexed by CNV also appeared to be involved in establishing the memory trace. The two cortical generators appear to interact in some types of short-term memory tasks, but not in others.

Adult↗
PubMed1985

Vulnerability to tardive dyskinesia.

Of 99 consecutive male patients studied at the North Chicago VA Tardive Dyskinesia Program, 58 had tardive dyskinesia and 41 did not. Factors that were significantly related, singly and in combinations, to tardive dyskinesia were 1) diagnosis of affective disorder with alcoholism and/or drug-induced parkinsonism, and 2) diagnosis of schizophrenia with advanced age (over 50) and/or prolonged hospitalization (over 14 years). A diagnosis of schizophrenia in patients under age 50 with short hospitalizations was not significantly associated with the presence of tardive dyskinesia.

Age Factors↗
PubMed1985

Test-retest stability of the WAIS-R in a clinical sample.

This study assessed WAIS-R test-retest stability for a sample of 21 psychiatric and neurological patients. The test-retest interval ranged from 2 weeks to 144 weeks, with a mean of 38 weeks. Subtest stability coefficients were highly significant; only Similarities, r(19) = .45, p less than .05, fell below a correlation of .74. The Verbal, Performance, and Full Scale IQs yielded highly significant stability coefficients (.79, .88, and .86). Nevertheless, the range of gain or loss for any single individual was comparatively large. On the Full Scale IQ, 18 of 21 (86%) subjects showed changes of 3 points or more, and 8 of 21 (38%) actually changed IQ classifications. Gain or loss in total score was unrelated to initial level of brightness on the Full Scale, age at initial testing, or days between examinations. Conversely, gain or loss on the Full Scale was associated strongly with years of education, r(19) = .55, p less than .01. When the sample was divided into brain-damaged and psychiatric subgroups, the difference in retest gain on the Full Scale IQ was nonsignificant.

Brain Damage, Chronic↗
PubMed1984

Study of chlorinated diphenyl ethers and chlorinated 2-phenoxyphenols as interferences in the determination of chlorinated dibenzo-p-dioxins and chlorinated dibenzo furans in biological samples.

Two classes of environmentally occurring chlorinated aromatic hydrocarbons which have mass spectral properties similar to the chlorinated dibenzo-p-dioxins (dioxins) and chlorinated dibenzofurans (furans) were studied. Standards of chlorinated diphenyl ethers (CDEs), and chlorinated 2-phenoxyphenols (CPPs) and their methyl ethers, along with the dioxins and furans were passed in steps through a simple method for the analysis of the latter compounds in biological samples. The CDEs, which interfere with the determination of furans by mass spectrometry, had similar extraction, high-performance liquid chromatographic and gas chromatographic properties as the furans but, in all cases studied, were well separated from them on an activated Florisil column using combinations of hexane and dichloromethane as eluting solvents. The higher CPPs on the other hand tended to generate dioxin residues by ring closure when exposed to strong hydrochloric acid solution during sample preparation. In addition, their methyl ethers containing four to six chlorines tracked completely through all stages of the method with the dioxins. Thus, if the methyl ethers of CPPs were present in a sample extract, additional mass spectral information would be needed to further differentiate them from dioxins in environmental samples.

Benzofurans↗