Local-circuit neurones in the medial prefrontal cortex (areas 25, 32 and 24b) in the rat: morphology and quantitative distribution

This paper is a light microscopical study describing the detailed morphology and quantitative distribution of local circuit neurones in areas 25, 32, and 24b of the medial prefrontal cortex (mPFC) in the rat. Cortical interneurones were identified immunocytochemically by their expression of calretinin (CR), parvalbumin (PV), and calbindin D-28k (CB) immunoreactivity. Neurones immunoreactive for gamma-aminobutyric acid (GABA) were also investigated, as were interneurones containing reduced nicotinamide adenine dinucleotide phosphate (NADPH) diaphorase activity. Several distinct classes of CR+, PV+, and CB+ neurones were identified; the most frequent were: bipolar/bitufted CR+ cells in upper layer 3; multipolar PV+ neurones in layers 3 and 5; and bitufted/multipolar CB+ neurones in lower layer 3. CB+ neurones resembling Martinotti and neurogliaform cells were also present in layers 5/6. The morphologies and depth distributions of each cell type were consistent across the three areas of mPFC studied. Seven classes of diaphorase-reactive mPFC neurone are described; these cells were composed about 0.8% of the total neurone population and had a peak distribution located in mid- to lower layer 5 in each area. In areas 32 and 25, three defined bands of diffuse NADPH diaphorase staining were located in layer 2 and in upper and deep layer 5. Diaphorase reactivity was very infrequently colocalised with either CR, PV, or CB immunoreactivities. The numerical densities of neurones (N(V), number of cells per mm3) in each layer were calculated stereologically. The mean total neuronal N(V) estimate for areas 25, 32, and 24b was 51,603 +/- 3,324 (mean +/- S.D.; n = 8). Significant interareal differences were detected. From cortical thickness data and neuronal N(V) estimates, the absolute number of neurones under 1 mm2 of cortical surface (N(C)) have been derived. The mean N(C) value for areas 25, 32, and 24b was 57,328 +/- 7,505 neurones. In immunolabelled Nissl-stained sections, CR+ neurones constituted an overall 4.0%, PV+ cells 5.6%, and CB+ 3.4% of the total neurone populations in mPFC. GABA+ cells represented a mean of 16.2% (14.8-17.2%) of neurones in areas 25, 32 and 24b. The absolute numbers of CR+, PV+, CB+, and GABA+ neurones within individual layers in a column of cortex under 1 mm2 of cortical surface (N(L)) have also been derived, with significant interareal differences in N(L) values being detected. The data provide the structural basis for a qualitative and quantitative definition of local cortical circuits in the rat mPFC.     

Intensive weekly chemotherapy for advanced gastric cancer using fluorouracil, cisplatin, epi-doxorubicin, 6S-leucovorin, glutathione, and filgrastim: a report from the Italian Group for the Study of Digestive Tract Cancer

PURPOSE: A multiinstitutional trial was performed to confirm the clinical activity, in terms of response rate and toxicity (primary objectives) and duration of responses and survival (secondary objectives), of an intensive weekly regimen in advanced gastric cancer. PATIENTS AND METHODS: Patients with measurable unresectable and/or metastatic gastric carcinoma received 1-day per week administration of cisplatin (CDDP) 40 mg/m2, fluorouracil (5FU) 500 mg/m2, epi-doxorubicin (epi-ADR) 35 mg/m2, 6S-stereoisomer of leucovorin 250 mg/m2, and glutathione 1.5 g/m2. On the other days, filgrastim was administered by subcutaneous injection at a dose of 5 mg/kg. One cycle of therapy consisted of eight 1-week treatments. Patients who showed a response or stable disease received a further 6 weeks of therapy. RESULTS: Of 105 enrolled patients, 11 had locally advanced unresectable disease only; 33 had primary nonresected and metastatic disease; 48 had metastatic disease and primary tumor resected; 10 had locoregional recurrence and metastatic disease; and three had locoregional recurrence only. After one cycle, 18 complete responses (CRs) and 47 partial responses (PRs) were achieved, for an overall response rate of 62% (95% confidence interval [CI], 53% to 71%). Twenty patients had stable disease and 20 progressed on therapy. The median survival duration of all 105 patients was 11 months, with 1- and 2-year survival rates of 42% and 5%, respectively. World Health Organization (WHO) grade III to IV toxicity, in terms of anemia, neutropenia, thrombocytopenia, and mucositis, was experienced by 40 patients (38%). There were no treatment-related deaths. CONCLUSION: These data support the results of the pilot study and confirmed the high activity of the regimen, with acceptable toxicity. This schedule deserves evaluation in the adjuvant setting.     

Arsenic in drinking water and incidence of urinary cancers

To investigate the effects of a new nonNMDA antagonist on the trisynaptic pathways in the hippocampus, the author examined kainate(KA)-induced generalized seizures in rats. A novel nonNMDA antagonist, YM90K, showed the blockade of the Schaffer collaterals in 2-deoxyglucose study (2-DG) and that the CA1-2 pyramidal cells of the hippocampus were preserved seven days after the KA injections. On the other hand, the control and MK-801 (NMDA-antagonist) treated rats did not depress the Schaffer collaterals and showed persistent hypermetabolism of glucose in the CA1 pyramidal cell layer, where neurons were not preserved seven days later. 2-DG was useful to reveal the effects of nonNMDA antagonist on the KA-induced generalized seizures. This suggests that YM90K is a potent nonNMDA antagonist and that it has a neuroprotective effect in rats.     

A new high density magnetoresistive tape head

An 8-track magnetic tape head for high-frequency, high-density applications is described. It includes an unshielded magnetoresistive read head and two thin-film record heads for bidirectional operation with write verification. The MR sensors are biased by specially shaped thin-film permanent magnets (PM) that provide fields along both sensor axes to linearize output and eliminate Barkhausen noise. Nearly all films in the head are deposited using dry processes. Deposition conditions for the PM have been optimized to produce a high-coercivity, high-remanence isotropic film. The final head assembly has a contour that utilizes longitudinal slots to achieve intimate contact with low head-to-tape pressure. The associated data channel uses both read and write equalization to obtain the desired output pulse shape from the unshielded head     

AUTO-SMASH: A self-calibrating technique for SMASH imaging

Recently a new fast magnetic resonance imaging strategy, SMASH, has been described, which is based on partially parallel imaging with radiofrequency coil arrays. In this paper, an internal sensitivity calibration technique for the SMASH imaging method using self-calibration signals is described. Coil sensitivity information required for SMASH imaging is obtained during the actual scan using correlations between undersampled SMASH signal data and additionally sampled calibration signals with appropriate offsets ink-space. The advantages of this sensitivity reference method are that no extra coil array sensitivity maps have to be acquired and that it provides coil sensitivity information in areas of highly non-uniform spin-density. This auto-calibrating approach can be easily implemented with only a small sacrifice of the overall time savings afforded by SMASH imaging. The results obtained from phantom imaging experiments and from cardiac studies in nine volunteers indicate that the self-calibrating approach is an effective method to increase the potential and the flexibility of rapid imaging with SMASH.     

Measurements and Calculations of the Halfwidth of Two Rotational Transitions of Water Vapor Perturbed by N2, O2, and Air

In this paper we report the results of both an experimental and theoretical study of the halfwidths of two transitions of water vapor. Measurements on the lines of the H216O and H218O isotopomers located at 325.1 and 203.4 GHz, respectively, were carried out in the temperature range 300-393 K, with N2 and O2 as perturbing gases. The foreign-broadening coefficients and their temperature-dependence parameters were determined assuming a Voigt profile and the usual temperature dependence for the halfwidth. The retrieved values are compared to values calculated using the complex semiclassical formalism of Robert and Bonamy. The assumed intermolecular potential is a combination of electrostatic and atom-atom components. This last contribution is defined as the sum of pairwise Lennard-Jones 6-12 interactions between the atoms of H2O and the atoms of the perturbing molecules expanded to eighth order. Also calculated are the pressure-induced shifts of the spectral lines for temperatures from 200 to 400 K. Calculated and experimental results are in good agreement, within +/-3.2%, except for the N2-broadening temperature coefficients, for which there are discrepancies as high as 23%. Air-broadening parameters are determined following the classical relation: gamma (air) = 0.79gamma (N2) + 0.21gamma (O2). Copyright 1999 Academic Press.