A Mott cell hybridoma

A hybridoma is described that exhibits all the characteristic features of Mott cells. It has spherules (Russell bodies) in the cytoplasm made up of dilated rough endoplasmatic reticulum and containing condensed immunoglobulin (λ₁ light chains). Some of the cells appear to be very fragile, and free spherules are often found on cell smears. Cells with the Mott cell characteristics are still able to divide, but they do not secrete immunoglobulin. Hybridomas of this kind should be useful for determining the place of the Mott cell within the scheme of B cell differentiation.     

Taenia crassiceps metacestode vesicular fluid antigens shared with the Taenia solium larval stage and reactive with serum antibodies from patients with neurocysticercosis

After removal of host (mouse) serum proteins (albumin, transferrin, IgG and another five unidentified proteins) by immunoaffinity chromatography, the vesicular fluid of T. crassiceps metacestodes (TcVF) was immunoelectrophoretically examined for antigens recognized by rabbit antiserum to aqueous crude extract of T. solium cysticerci. Based on a precipitate pattern developed in electroimmunodiffusion, nine cross-reactive antigens could be demonstrated. In the ELISA, TcVF was shown to be a potent antigen for the demonstration of IgG antibodies in the sera of Mexican patients (n = 14) with confirmed neurocysticercosis (mean E490 values +/- SD: 0.39 +/- 0.38) although it was less sensitive when compared to T. solium VF (0.95 +/- 0.54). Sensitivity was much higher using cross-reactive TcVF antigens selected by immunoaffinity chromatography with rabbit IgG antibodies to larval T. solium crude extract (0.87 +/- 0.57). SDS-PAGE fluorograph of cross-reactive, radioiodinated TcVF protein antigens and selected by antibodies of individual neurocysticercosis sera (n = 13), exhibited six to nine bands depending on the serum tested. Altogether ten 125I-labelled proteins (Mr range from about 20,000 to 200,000) were recognized by neurocysticerosis antibodies. Four proteins (Mr about 22,000, 25,000, 32,000 and 45,000) were detected by all sera.     

Cardiovascular concomitants of tactile and acoustic startle responses in spontaneously hypertensive and normotensive rats

In the present study we have simultaneously investigated cardiovascular and behavioral responses to repeated tactile and acoustic stimulation in adult, male, spontaneously hypertensive rats (SHR) and normotensive Wistar-Kyoto rats (WKY). Blood pressure and heart rate responses were increased in SHR vs. WKY rats following both types of stimuli. The pressor responses, but not the tachycardic responses, habituated with repeated stimulation in both strains and with both stimulus modalities. The rates of habituation were not significantly different between the two strains. Magnitudes of the behavioral startle responses were significantly elevated in SHR vs. WKY rats with tactile, but not with acoustic stimulation. No significant differences were found between the two strains with respect to the latency, with which the startle responses occurred. These data indicate that SHR as compared to WKY rats respond to repeated stimulation with two different stimulus modalities (tactile and acoustic) with significantly increased pressor and tachycardic responses. This cardiovascular hyperreactivity is not due to different degrees of habituation between the two strains and can be observed even in the absence of significant differences in standard behavioral startle response measures.     

Tetrodotoxin block of A-fibre afferents from skin and muscle - a tool to study pure C-fibre effects in the spinal cord

The properties of tetrodotoxin (TTX)-resistant C-fibre afferents of the dorsal roots were tested in Sprague-Dawley rats. Dorsal roots (L4-L6) were blocked with TTX (0.5-1 micro M) and the amplitude of the first response of the dorsal horn superficial interneurones (cord dorsum potential, CDP) to electrical stimulation of peripheral C-fibres in combination with natural noxious stimulation was taken as measure for intact conductivity of different kinds of noxious input by means of the C-fibre refractory period. After blockade of dorsal roots with TTX, formerly masked CDPs from muscle C-fibre afferents were uncovered. Noxious pressure to the gastrocnemius soleus muscle belly and noxious pinch to the calcanean tendon proved to be TTX resistant and therefore was propagated centrally. For cutaneous heat nociceptors it could also be shown that conductivity was intact after blockade of the dorsal roots with TTX. However, we could not exclude the TTX resistance of non-nociceptive receptors of muscle or skin. Nevertheless, blockade of afferents with TTX together with suitable stimulation techniques proves to be a reliable method to investigate central effects from C-fibre afferents without contaminating effects from A-fibres in the rat.     

The interleukin-13 production by peripheral blood T cells from atopic dermatitis patients does not require CD2 costimulation

BACKGROUND: Although allergic mechanisms appear to be important, the pathogenesis of both extrinsic and intrinsic forms of atopic dermatitis (AD) is unknown. METHODS: We compared the cytokine production of peripheral blood mononuclear cells of extrinsic AD (EAD) and intrinsic AD (IAD) patients and normal control individuals after stimulation with anti-CD3 and/or anti-CD28 monoclonal antibodies (mAbs) in the presence or absence of anti-CD2-blocking mAb. The cytokine production was measured by immunoassays in supernatants of 24-hour cultures. RESULTS: EAD patients showed a decreased capacity to synthesize interferon gamma and granulocyte-macrophage colony-stimulating factor upon anti-CD3 mAb stimulation as compared with IAD patients. Both EAD and IAD patients demonstrated an increased production of interleukin (IL)-5 and IL-13. As expected, interferon gamma, granulocyte-macrophage colony-stimulating factor, and IL-5 levels were reduced in the presence of anti-CD2-blocking mAbs. CD28 costimulation restored the release in cultures with anti-CD2 mAbs added, suggesting that CD2 and CD28 have redundant functions in T cell activation and subsequent cytokine production. Strikingly, the IL-13 production was not blocked by anti-CD2 mAbs and also not increased by agonistic anti-CD28 mAb, in particular within the EAD patient group. CONCLUSION: The signalling pathway initiated by the T cell receptor complex leading to increased IL-13 production in AD patients appears to be highly sensitive and is largely independent on CD2 costimulatory signals.     

Radiopharmacokinetics and radiation dose from 99mTc-HM-PAO (Preliminary report)

Whole body retention measurements were performed in volunteers after i.v. injection of ^99mTc-HM-PAO (Ceretec^®). The organ accumulation was measured in mice and data were transferred to standard man according to ICRP. Absorbed dose calculations were made with these data by using the concept of absorbed fractions (MIRD method). In man, the whole body retention and the retention in the brain could be calculated by direct measurement, absorbed doses to the other organs could only be derived from animal data. The absorbed dose to the brain derived from human data (10.3 Gy/MBq) is greater by a factor of 2 than that derived from animal data. The highest absorbed dose was received by the thyroid (24.4 Gy/MBq), the absorbed dose to the ovaries, testes and whole body ranged from 2.8 to 4.2 Gy/MBq.Dedicated to Professor Dr. Guenter Liess on the occasion of his 65th anniversary     

Pre-irradiation chemotherapy in children with high-grade astrocytoma: Tumor response to two cycles of the ‘8-drugs-in-1-day’ regimen

SummaryPurpose This study was undertaken to evaluate the radiographie response to two cycles of chemotherapy prior to irradiation in newly diagnosed children with high-grade astrocytomas.Patients and methods. One hundred and thirty children less than 21 years of age with newly-diagnosed highgrade astrocytoma were treated with the eight-drugs-in-one-day chemotherapy regimen as part of a phase III multi-institutional Childrens Cancer Group (CCG) trial. Computerized Tomographic (CT) or Magnetic Resonance Image (MRI) scans, obtained after two cycles of chemotherapy had been administered, were compared with post-operative scans to determine treatment response. Scans were evaluated by institutional radiologists, and were reviewed centrally by a single neuroradiologist.Results Of 79 patients with evaluable post-operative residual tumor on CT or MRI scans, 26 (33%) were determined on institutional evaluation to have had an objective response. However, central review of scans documented responses on only 14/79 (18%). A significantly higher response rate on central review was observed for those children 36 months of age or less at study entry than for older children (33% v 11%; p < 0.001). However, a higher disease progression rate was also observed for those children 36 months of age or less than for older children (21% v 2.6%; p < 0.001).Conclusion In this study, the largest yet reported in newly-diagnosed children with high-grade astrocytomas, the chemotherapy regimen has activity in younger children. The differences in response rates reported by institutional and central review highlight the difficulties inherent in assessing response to brain tumor therapy. However, the study does demonstrate the consistent ability of radiologists to identify disease progression within the institutional and central reviews.     

Amphetamine disrupts P50 suppression in normal subjects.

BACKGROUND: P50 suppression is viewed as an operational measure of sensory "gating" that is reduced in patients with schizophrenia and their family members. Previous reports have demonstrated that neural gating is regulated by monoaminergic tone in rodent models of P50 suppression. METHODS: In this study, 11 healthy subjects participated in P50 event-related potential recordings at baseline and after either oral administration of dextroamphetamine (.3 mg/kg) or placebo, to determine if the administration of a monoaminergic agonist produces P50 suppression deficits similar to those observed in patients with schizophrenia. RESULTS: As hypothesized, amphetamine disrupted the suppression of the P50 event-related potential. There was a statistically significant decrement in P50 suppression during the amphetamine challenge condition (t10 = 3.15, p < .01, mean difference = -44.1%, d = -2.5) relative to the baseline P50 condition. A comparison of P50 suppression in the placebo and amphetamine conditions (both after a baseline recording session) revealed a significant amphetamine-induced disruption of P50 suppression (t6 = 3.71, p < .01, mean difference = -54.4%, d = -3.14). CONCLUSIONS: The biochemical alterations associated with an amphetamine-induced disruption of P50 suppression in this study may be related to the pathophysiology of P50 suppression deficits in schizophrenia. The findings are consistent with several careful examinations of suppression deficits in rodent models that have identified the monoaminergic regulation of P50 suppression. These data indicate that amphetamine induces a disruption of P50 suppression in normal subjects.     

Critical review of the categorical structures of the core Conflictual Relationship Theme Method (CCRT)

The CCRT-method developed by Lester Luborsky is the most widespread and best established method to assess relationship structures in the field of psychodynamic psychotherapy research. Although its categorical structures are criticised in many different ways there have not been any attempts to modify them. This article points out the inconsistency of the current categorical system and demonstrates first approaches to alternative solutions. For this purpose genetic algorithms are used. Their application in psychotherapy research is demonstrated here for the first time.     

Regionally selective effects of intracerebral dopamine infusion on sensorimotor gating of the startle reflex in rats

Systemic administration of dopamine (DA) agonists markedly disrupts sensorimotor gating in rats as measured by prepulse inhibition (PPI) of the acoustic startle response. A qualitatively similar, but quantitatively weaker disruption of PPI follows DA infusion into the nucleus accumbens (NAC). The present study was designed to determine whether forebrain DA terminal fields other than the NAC contribute to the DAergic modulation of PPI. PPI was impaired significantly after infusion of DA (0–40 µg) into the NAC or anteromedial striatum, but not after DA infusion into the orbital cortex or posterolateral striatum. DA infusion into the amygdala also disrupted PPI, but this disruption was accompanied by a dose-dependent decrease in startle amplitude. These results suggest that DA overactivity in the both NAC and anteromedial striatum contribute to the gating-disruptive effects of systemically administered DA agonists, and that DA overactivity in mesocortical, mesoamygdaloid and non-limbic mesostriatal DA systems are not major substrates for a DAergic modulation of PPI.