Preliminary evaluation of cyto-rich: An improved automated cytology preparation

A new cervical cytology monolayer preparation system called Cyto-Rich was evaluated. Using samples from 557 patients, Cyto-Rich monolayers were compared to matched conventional smears. After conventional smears were prepared and spray fixed, residual exfoliated cells were transferred to preservative fluid. The cell suspensions were gently disaggregated and the epithelial component enriched with gradient centrifugal sedimentation. The batched samples were then placed on the Cyto-Rich work station where slides are automatically prepared and stained. The results demonstrate that Cyto-Rich prepared monolayers are vastly superior to the conventional smears for cell presentation. While the study showed 99% overall concordance, Cyto-Rich improved the detection of low-grade cervical intraepithelial lesions.     

Quantitative assessment of the microstructure of rat behavior: I.f(d), The extension of the scaling hypothesis

Previous studies demonstrated that drug effects on the movement sequences of rats in unconditioned motor activity paradigms can be quantified by scaling measures that describe the average relationship between a variable of interest and an experimental parameter. However, rats engage in a wide variety of geometrically distinct movements that can be influenced differentially by drugs. In this investigation, the extended scaling approach is presented to capture quantitatively the relative contributions of geometrically distinct movement sequences to the overall path structure. The calculation of the spectrum of local spatial scaling exponents,f(d), is based on ensemble methods used in statistical physics. Results of thef(d) analysis confirm that the amount of motor activity is not correlated with the geometrical structure of movement sequences. Changes in the average spatial scaling exponent,d, correspond to shifting the entiref(d) function, and indicate overall changes in path structure. With the extended scaling approach, straight movement sequences are assessed independently from highly circumscribed movements. Thus, thef(d) function identifies drug effects on particular ranges of movement sequences as defined by the geometrical structure of movements. More generally, thef(d) function quantifies the relationship between microscopically recorded variables, in this paradigm consecutive (x, y) locations, and the macroscopic behavioral patterns that constitute the animal's response topography.Exemplary calculations of path segments with different geometrical characteristics can be obtained from the authors. Questions regarding the computational implementation of this method should be addressed to MPP preferably via email (martin@rat.ucsd.edu) or FAX (619-543-2493)     

Ultrahistochemical demonstration of cations in the guinea pig organ of Corti.

The distribution of cations in the guinea pig organ of CORTI was studied by means of the ultrahistochemical pyroantimonate method. In the outer hair cells precipitates were localized at the cell membrane, at stereocilia, in the subplasmalemmal cisterns, in the the nucleus, in mitochondria and within the ground plasm. Coarse precipitates at the cell membrane may consist mainly of cations other than calcium ions. The subplasmalemmal cisterns are suggested to sequester cations in the outer hair cells. The mechanism of the trapping reaction and factors injuring this histochemical method are discussed.     

Chromosome mapping of biological pathways by fluorescence-activated cell sorting and cell fusion: Human interferon gamma receptor as a model system

Human chromosome 6 encodes both the interferon gamma receptor as well as the class I major histocompatability complex antigens, HLA-A, -B, and -C. However, the presence of chromosome 6 in somatic cell hybrids is insufficient to confer sensitivity to human interferon gamma (Hu-IFN-) as assayed by class I HLA induction; it is necessary for both human chromosomes 6 and 21 to reside in the hybrid to generate a response to Hu-IFN-. Treatment of such a hamster-human hybrid, Q72-18, with Hu-IFN- induces the class I HLA antigens. Q72-18 cells selected by fluorescence-activated cell sorting for the loss of class I HLA induction also lost human chromosome 21. Fusions of such cells to a hybrid that contains only human chromosome 21 reconstitutes HLA antigen induction by Hu-IFN-. Furthermore, fusions of hybrids containing a translocated human chromosome 6q and the HLA-B7 gene to a line containing only human chromosome 21 or a translocated 21q also reconstitutes HLA-B7 mRNA and antigen induction by Hu-IFN-. Thus the segregation of cells on the basis of a biological effect by fluorescence-activated cell sorting and reconstitution by hybrid fusion provides a strategy by which some biological pathways can be mapped at a chromosomal level.     

The acoustic startle reflex and its modulation: effects of age and gender in humans

The acoustic startle reflex and its modulation by prepulse inhibition (PPI) and habituation are used in many studies in different fields of neuropsychiatric research. The aim of this study was to examine the effects of age and gender on PPI, startle magnitude, and habituation in healthy human volunteers. Twenty-seven male and 28 female participants of four different age groups (range: 20-60 years) were investigated in an acoustic startle paradigm using a startle stimulus of 115 dB and a prepulse of 86 dB (16 dB over the white noise background) with five different lead intervals (30, 60, 120, 240, and 2000 ms). Seventeen males and 16 female participants were tested three times at monthly intervals. Aged participants showed significantly lower startle magnitude and significantly more habituation than younger participants, but there was no effect of age on PPI or prepulse facilitation. Moreover, there were no effects of gender on startle magnitude, PPI, prepulse facilitation, or habituation measures. Healthy males and females exhibited stable startle magnitudes and PPI across sessions. The results demonstrated that PPI and startle are reliable measures of sensory information processing in both genders and that startle magnitude and habituation are age-dependent measures.     

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.     

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.