Dopaminergic Modulation of Dynamic Emotion Perception

Emotion recognition abilities are fundamental to our everyday social interaction. A large number of clinical populations show impairments in this domain, with emotion recognition atypicalities being particularly prevalent among disorders exhibiting a dopamine system disruption (e.g., Parkinson's disease). Although this suggests a role for dopamine in emotion recognition, studies employing dopamine manipulation in healthy volunteers have exhibited mixed neural findings and no behavioral modulation. Interestingly, while a dependence of dopaminergic drug effects on individual baseline dopamine function has been well established in other cognitive domains, the emotion recognition literature so far has failed to account for these possible interindividual differences. The present within-subjects study therefore tested the effects of the dopamine D2 antagonist haloperidol on emotion recognition from dynamic, whole-body stimuli while accounting for interindividual differences in baseline dopamine. A total of 33 healthy male and female adults rated emotional point-light walkers (PLWs) once after ingestion of 2.5 mg haloperidol and once after placebo. To evaluate potential mechanistic pathways of the dopaminergic modulation of emotion recognition, participants also performed motoric and counting-based indices of temporal processing. Confirming our hypotheses, effects of haloperidol on emotion recognition depended on baseline dopamine function, where individuals with low baseline dopamine showed enhanced, and those with high baseline dopamine decreased emotion recognition. Drug effects on emotion recognition were related to drug effects on movement-based and explicit timing mechanisms, indicating possible mediating effects of temporal processing. Results highlight the need for future studies to account for baseline dopamine and suggest putative mechanisms underlying the dopaminergic modulation of emotion recognition.SIGNIFICANCE STATEMENT A high prevalence of emotion recognition difficulties among clinical conditions where the dopamine system is affected suggests an involvement of dopamine in emotion recognition processes. However, previous psychopharmacological studies seeking to confirm this role in healthy volunteers thus far have failed to establish whether dopamine affects emotion recognition and lack mechanistic insights. The present study uncovered effects of dopamine on emotion recognition in healthy individuals by controlling for interindividual differences in baseline dopamine function and investigated potential mechanistic pathways via which dopamine may modulate emotion recognition. Our findings suggest that dopamine may influence emotion recognition via its effects on temporal processing, providing new directions for future research on typical and atypical emotion recognition.

Tight regulation from a single tet-off rAAV vector as demonstrated by flow cytometry and quantitative, real-time PCR

Vectors suitable for delivery of therapeutic genes to the CNS for chronic neurodegenerative diseases will require regulatable transgene expression. In this study, three self-regulating rAAV vectors encoding humanized green fluorescent protein (hGFP) were made using the tetracycline (tet)-off system. Elements were cloned in different orientations relative to each other and to the AAV internal terminal repeat (ITRs). The advantage of this vector system is that all infected cells will carry both the 'therapeutic' gene and the tet-regulator. To compare the efficiency of the vectors, 293T cells infected by each vector were grown in the presence or absence of the tet-analog doxycycline (dox). Cells were analyzed by flow cytometry for hGFP protein expression, and quantitative RT-PCR (QRT-PCR) for levels of hGFP mRNA and the tet-activator (tTA) mRNA. In the presence of dox, cells infected with one of the vectors, rAAVS3, showed less than 2% total fluorescent intensity and mRNA copy number than cells grown without dox. The other two vectors were significantly more leaky. Levels of tTA mRNA were not affected by dox. The S3 vector also displayed tight regulation in HeLa and HT1080 cells. To assess regulation in the brain, the S3 vector was injected into rat striatum and rats maintained on regular or dox-supplemented water. At 1 month after vector injection, numerous positive cells were observed in rats maintained on regular water whereas only rare positive cells with very low levels of fluorescence were observed in rats maintained on water containing dox. The QRT-PCR analysis showed that dox inhibited expression of hGFP mRNA in brain by greater than 99%. These results demonstrate that exceedingly tight regulation of transgene expression is possible using the tet-off system in the context of a self-regulating rAAV vector and that the specific orientation of two promoters relative to each other and to the ITRs is important. Regulatable vectors based on this design are ideal for therapeutic gene delivery to the CNS.

Effect of testing for IgG avidity in the diagnosis of Toxoplasma gondii infection in pregnant women: experience in a US reference laboratory

The usefulness of testing for IgG avidity in association with Toxoplasma gondii was evaluated in a US reference laboratory. European investigators have reported that high-avidity IgG toxoplasma antibodies exclude acute infection in the preceding 3 months. In this US study, 125 serum samples taken from 125 pregnant women in the first trimester were chosen retrospectively, because either the IgM or differential agglutination (AC/HS) test in the Toxoplasma serologic profile suggested or was equivocal for a recently acquired infection. Of 93 (74.4%) serum samples with either positive or equivocal results in the IgM ELISA, 52 (55.9%) had high-avidity antibodies, which suggests that the infection probably was acquired before gestation. Of 87 (69.6%) serum samples with an acute or equivocal result in the AC/HS test, 35 (40.2%) had high-avidity antibodies. Forty women were given spiramycin, to prevent congenital transmission, and 7 (17.5%) had high-avidity antibodies. These findings highlight the value of testing a single serum sample obtained in the first trimester of pregnancy for IgG avidity.

Detection of immunoglobulin M antibodies to P35 antigen of Toxoplasma gondii for serodiagnosis of recently acquired infection in pregnant women

We examined the efficiency of detection of immunoglobulin M (IgM) antibodies to a 35-kDa antigen (P35) of Toxoplasma gondii for serodiagnosis of acute infection in pregnant women. A double-sandwich enzyme-linked immunosorbent assay (ELISA) with recombinant P35 antigen (P35-IgM-ELISA) was used for this purpose. On the basis of the clinical history and the combination of results from the toxoplasma serological profile (Sabin-Feldman dye test, conventional IgM and IgA ELISAs, and the differential agglutination test), the patients were classified into three groups: group I, status suggestive of recently acquired infection; group II, status suggestive of infection acquired in the distant past; group III, status suggestive of persisting IgM antibodies. Eighteen (90.0%) of 20 serum samples from group I patients were positive by the P35-IgM-ELISA, whereas none of the 33 serum samples from group II patients were positive. Only 4 (25.0%) of 16 serum samples from group III patients were positive by the P35-IgM-ELISA, whereas all these serum samples were positive by the conventional IgM ELISA. These results indicate that demonstration of IgM antibodies against P35 by the P35-IgM-ELISA is more specific for the acute stage of the infection than demonstration of IgM antibodies by the ELISA that uses a whole-lysate antigen preparation. Studies with sera obtained from four pregnant women who seroconverted (IgG and IgM antibodies) during pregnancy revealed that two of them became negative by the P35-IgM-ELISA between 4 and 6 months after seroconversion, whereas the conventional IgM ELISA titers remained highly positive. The P35-IgM-ELISA appears to be useful for differentiating recently acquired infection from those acquired in the distant past in pregnant women.

Focal brain injury, FGF-2 and the adverse effects of excessive motor demand on cortical and nigral degeneration: marked protection by delayed intermittent exposure to halothane

The neuroprotective potential of halothane anesthesia was investigated following unilateral electrolytic lesions to the forelimb representation area of the sensorimotor cortex (FL-SMC). Previously, it was found that the FL-SMC lesion increases substantially in size when the intact forelimb is immobilized with a plaster of paris cast for the first 7 days postlesion, which forces extreme overuse of the impaired forelimb during a time when nonlethally damaged tissue is vulnerable to behavioral demand. Initially, the purpose of this study was to investigate whether intracisternal infusion of basic fibroblast growth factor (bFGF or FGF-2), a potent neurotrophic factor that has been shown to have neuroprotective and plasticity promoting properties in focal stroke and other injury models, could prevent this use-dependent exaggeration of injury. Although intracisternal bFGF (starting 24 h after surgery, twice per week) was not found to produce significant neuroprotective or behavioral effects, the brief exposure to halothane anesthesia (15-20 min) during bFGF or vehicle administration was found to prevent expansion of the lesion size, and to reduce delayed loss of neurons in the substantia nigra pars reticulata (SNr). The data have implications for investigations of the effects of neurotrophic factor in vivo, and other investigations requiring brief, intermittent halothane anesthesia.

Evaluation of six commercial kits for detection of human immunoglobulin M antibodies to Toxoplasma gondii. The FDA Toxoplasmosis Ad Hoc Working Group

As a result of reports received by the Food and Drug Administration (FDA) of false-positive results obtained with FDA-cleared in vitro diagnostic kits for the detection of Toxoplasma-specific human immunoglobulin M (IgM) antibodies, an FDA-sponsored evaluation of six kits was performed. A battery of 258 serum specimens, including 30 specimens drawn 1 to 5 months after initial Toxoplasma infection and 228 specimens from Toxoplasma IgG-positive individuals, Toxoplasma IgG-negative individuals, rheumatoid factor-positive persons, and persons determined to be Toxoplasma IgM positive by commercially available assays, was assembled, randomly assorted, and coded. The battery was tested at the FDA with six commercially available kits, at the Palo Alto Medical Foundation (PAMF) by the PAMF double-sandwich IgM enzyme-linked immunosorbent assay (PAMF IgM ELISA), and at the Centers for Disease Control and Prevention (CDC) by the CDC EIA IgM. The results of the PAMF IgM ELISA that were obtained with the battery were considered to be the "gold standard" for this study; specificity rates were computed by considering the PAMF results to be 100% specific. Sensitivity and specificity rates were found to be as follows: CDC EIA IgM, 100 and 99.1%, respectively; Abbott IMx Toxo IgM, version 1, 100 and 77.5%, respectively; Abbott IMx Toxo IgM, version 2, 93.3 and 97.3%, respectively; Abbott Toxo-M EIA, 100 and 84.2%, respectively; BioMérieux Vitek VIDAS Toxo IgM, 100 and 98.6%, respectively; BioWhittaker Toxocap-M, 100 and 95.9%, respectively; Gull Toxo IgM, 97 and 85.6%, respectively; and Sanofi Diagnostics Pasteur Platelia Toxo IgM, 100 and 96.8%, respectively. Although the extent of false-positive reactions with these kits cannot be calculated because the study was retrospective and sample choices were biased, the results may be useful as an indicator of the relative specificities of these kits.

False-positive results in immunoglobulin M (IgM) toxoplasma antibody tests and importance of confirmatory testing: the Platelia Toxo IgM test

Although tests for detection of immunoglobulin M (IgM) toxoplasma antibodies have been reported to have a high degree of accuracy, it is well recognized by investigators in the United States and Europe that false-positive results may occur with many of these tests, at times to an alarming degree. Unfortunately, this information is not well documented in the literature. Studies on various toxoplasma IgM test kits are frequently flawed. The investigators often use reference tests which have not previously been carefully evaluated as well as sera that were not appropriate to answer the question of how often false-positive results might occur. We recently had the unique opportunity to evaluate the accuracy of the Platelia Toxo IgM test in 575 serum samples obtained during an outbreak of toxoplasmosis which occurred in 1995 in the Capital Regional District of British Columbia, Canada. When compared with results obtained in a reference IgM enzyme-linked immunosorbent assay (ELISA), the Platelia Toxo IgM test had a sensitivity of 99.4%, specificity of 49.2%, positive predictive value of 51.9%, negative predictive value of 99.3%, and an overall agreement of 67.0%. In an attempt to resolve discrepancies between these two tests, a serological profile (Sabin-Feldman dye test, IgA and IgE antibody tests, differential agglutination [AC/HS] test, and IgG avidity method) was performed. Of 153 serum samples that were positive in the Platelia Toxo IgM test and negative in the IgM ELISA, 71 (46.4%) were negative in the Sabin-Feldman dye test. Of the serum samples that were positive in the dye test, 77 (93.9%) had a serological profile most compatible with an infection acquired in the distant past. These results reveal high numbers of false-positive results in the Platelia Toxo IgM test and highlight the importance of appropriate evaluation of commercial tests that are currently being marked. Our results also emphasize the importance of confirmatory testing to determine whether the results of an IgM antibody test reflect the likelihood of a recently acquired infection.

Study of Abbott Toxo IMx system for detection of immunoglobulin G and immunoglobulin M toxoplasma antibodies: value of confirmatory testing for diagnosis of acute toxoplasmosis

We compared the Abbott Toxo immunoglobulin G (IgG) and IgM IMx assays with the Sabin-Feldman dye test and an IgM enzyme-linked immunosorbent assay (ELISA) in 398 serum samples previously tested in our laboratory (retrospective group) and 1,000 consecutive serum samples, tested as they were received in our laboratory in 1995 (prospective group). In the retrospective group, the IgG IMx had a sensitivity of 100%, specificity of 99.0%, positive predictive value of 99.0%, negative predictive value of 100%, and overall agreement of 99.5%. The percentages for the IgM IMx were 97.8, 99.0, 98.9, 98, and 98.4%, respectively. In the prospective group, the IgG IMx had a sensitivity of 97.8%, specificity of 98.7%, positive predictive value of 97.8%, negative predictive value of 98.7%, and overall agreement of 98.4%. The percentages for the IgM IMx were 88.3, 95.9, 74.7, 98.3, and 95%. A serological profile (IgA and IgE antibodies and the differential agglutination [AC/HS] test) was performed in an attempt to resolve discrepancies. Of 21 serum samples that were positive in the IgM IMx and negative in the IgM ELISA, 19 had serological profiles which were most compatible with an infection acquired in the distant past. Of 8 serum samples which were positive in the IgM ELISA and negative in the IgM IMx, 5 had serological profiles which were most compatible with an infection acquired in the distant past. Of the 55 serum samples that were positive in both IgM tests, 21 were from patients who had serological profiles which were most compatible with an infection acquired in the distal past. In conclusion, our data highlight the importance of confirmatory testing for the diagnosis of recently acquired infection with Toxoplasma gondii. When compared with the dye test and IgM ELISA, the Toxo IgG and IgM IMx assays, respectively, revealed high overall agreement in the retrospective and prospective study.

Computer-assisted morphometric analysis of absorptive and follicle-associated epithelia of Peyer's patches in sheep foetuses and lambs indicates the presence of distinct T- and B-cell components

The phenotypes of lymphocytes infiltrating the epithelium of the jejunal and ileal Peyer's patches in foetal sheep at about 130 days gestation and 2-month-old lambs were examined using indirect immunoperoxidase histochemistry, a panel of monoclonal antibodies and enzyme histochemistry. Computer-assisted morphometric analysis enabled the relative size of reactive areas within epithelia to be estimated. The comparison of the intraepithelial lymphocyte populations associated with structurally developed Peyer's patches of foetal sheep and those of lambs allowed assessment of the impact of extrinsic factors from which the sheep foetus is shielded. The study confirmed the postnatal expansion in the villous intraepithelial lymphocyte population and showed that this expansion involved the CD8 and gamma delta phenotypes. CD4 lymphocytes did not appear in the follicle-associated epithelium until after birth. Unlike the villous epithelium, the follicle-associated epithelium had a high frequency of IgM+ and MHC II+ cells, which was dramatically reduced after birth. This postnatal reduction was particularly prominant in the follicle-associated epithelium of the jejunal Peyer's patch, where the frequency of IgM+ cells fell from 12.4% in foetal sheep to 0.7% in lambs. Double staining for alkaline phosphatase in the jejunal Peyer's patch suggested that clusters of IgM+ cells were associated with M cells.

[Pregnancy following organ transplantation]

In 17 of 74 patients, in the 20-40 years of age group, who had undergone an organ transplantation (kidney or liver), the course and outcome of pregnancy were evaluated. In three cases, the pregnancies ended in premature miscarriage and in five cases they were terminated for medical reasons. Nine infants were born alive between the 32nd to the 40th week of gestation, six of them spontaneously, three of them by abdominal Caesarean section. One of these infants born in the 32nd week of gestation with a birth weight of 800 grams died on the second day after birth. One infant born in the 33rd week of gestation showed incidence of a persistent ductus arteriosis Botalli. Four of the nine newborns suffered from intrauterine dystrophy. The birth weight of four further infants corresponded to the 10th to 25th percentile. Neither the incidence of a maternal varicella zoster infection in the early stages of pregnancy nor the reactivation of a herpes simplex (HSV) and cytomegalia virus infection during the pregnancy resulted in any perceptible damage to the infant or transplant. During pregnancy, three of the mothers were treated with immunosuppressants, either with a combination of azathioprine and prednisone (conventional) or cyclosporine (CSA) and prednisone, or with a combination of all three drugs (triple therapy). As opposed to the newborn of those mothers, who had been treated conventionally, the newborn of those treated with CSA showed post partum a tendency towards hypocalcaemia. Two of the mothers gave birth to their infants outside the Federal Republic of Germany.(ABSTRACT TRUNCATED AT 250 WORDS)

Three sera defining a new granulocyte-monocyte-T-lymphocyte antigen

Three sera containing antibodies recognizing a previously undescribed antigen on granulocytes were found during testing of sera from multiparous donors. All of the antibody producers were in good health. None had a history of transfusion. Using the granulocyte agglutination assay the sera recognize a single antigen which is not associated with the neutrophil antigens NA1, NA2, NB1, NC1, ND1, NE1, 5a, 5b, 9a, nor common red blood cell or HLA antigens. The three sera did not react with autologous cells or with the cells of the other antibody producers. Granulocytes from one antibody producer did not absorb antibody activity from any of the three sera. The antigen was found in large quantities on granulocytes and monocytes, in smaller quantities on T lymphocytes, and not on B lymphocytes, red cells, and platelets. The sera reacted with 340 of 343 random donors (99.1%) and were negative with the same donor cells. Family studies showed autosomal dominant inheritance of the antigen. Five of 12 sibs in three families lacked this antigen (not statistically different from the expected ratio). The calculated gene frequency for the gene controlling the production of this antigen is 0.906. There appeared to be no association to the HLA, NA or Rh loci or to the X or Y chromosomes. None of the infants of these three women showed clinical signs of alloimmune neonatal neutropenia.

A microtiter modification of granulocyte immunofluorescence

The granulocyte immunofluorescence test (GIFT) is valuable for detecting allogeneic and autologous granulocyte antibodies. However, the original tube technique (macro GIFT) requires 50-100 microliters of serum and 10(6) granulocytes with time-consuming washing steps which cause cell loss. We report a modification (micro GIFT) using microtiter trays which requires only 20 microliters of serum and 2 X 10(5) granulocytes. The modified method conserves reagents, reduces the time required for washing by 67%, decreases cell loss in washing by 74%, reduces the volume of conjugate required by 67%, and compares favorably with the macro GIFT in accuracy, specificity, and sensitivity.

Severe pulmonary hypersensitivity associated with passive transfusion of a neutrophil-specific antibody

A life-threatening pulmonary hypersensitivity reaction accompanied by profound leucopenia and transient hypocomplementaemia developed in a 73-year-old man after repair of an abdominal aortic aneurysm. A neutrophil-specific antibody, anti-NA2) was demonstrated by granulocyte immunofluorescence and microagglutination in one of the transfused donor units. In addition, activated complement component C5a was generated in vitro by incubation of the patient's serum with the aortic graft material. This severe clinical reaction may have resulted from the interaction of the transfused anti-NA2 antibody with complement activation induced by the aortic graft material.