Dose-related effects of nebulized metaproterenol in asthmatic children

The dose-related effects of inhaled 5% metaproterenol solution in asthmatic children between the ages of six and 12 years with acute bronchospasm were evaluated. Tests included FEV1.0, FEF25-75, and PEFR. For entry into the study, subjects were required to have an FEV1.0 or an FEF25-75 less than 80% of the child's predicted normal value based on height and race. Sixty children were randomly assigned in double-blind fashion to receive one of four different doses of 5% metaproterenol inhalant solution: 0.0 ml (placebo), 0.1 ml, 0.2 ml, or 0.3 ml. Drug efficacy was assessed by spirometry using a DeVilbiss Surveyor I spirometer. Spirometry was performed prior to inhalation of the test dose (baseline) and four times after inhalation: immediately after and 15, 30, and 60 minutes after inhalation. Patients in the three treated groups had significantly higher peak post-dose FEV1.0 and FEF25-75 than the placebo group but were not significantly different from one another. There was a significant relationship between dose and incidence of side effects. These results suggest that 0.1 ml (5 mg) of nebulized metaproterenol may provide as much bronchodilatation as higher doses with fewer side effects.     

Regulatory mechanisms in cell-mediated immune responses. V. H-2 homology requirements for the production of a minor locus-induced suppressor factor

A mixed leukocyte reaction suppressor factor is produced by spleen cells sensitized in vivo and restimulated in vitro across non-H-2 antigenic barriers. Cells capable of producing this factor appear in the spleens of minor locus-immunized animals later than in animals sensitized to major histocompatibility complex-encoded antigens. However, both H-2 and non H-2-induced factors suppress proliferative responses to any alloantigen. Splenocytes from animals immunized with H-2-identical, minor locus-disparate cells produce suppressor factor in vitro only when restimulated with cells sharing both H-2 and non-H-2 antigens with the in vivo stimulators.     

The neurophysiological correlates of colour and brightness contrast in lateral geniculate neurons

We report on experiments which were undertaken in an attempt to clarify mechanisms underlying the contrast effects of chromatic surround illumination on spectral responsiveness of cells in the parvocellular layers of the LGN (P-LGN-cells), that had been demonstrated under standard conditions in the preceding companion paper. The experiments were done in anesthetized macaques (Macaca fascicularis). In some neurons, S-potentials were recorded together with the post-synaptic action potentials, and all effects seen in P-LGN-cells were present already in their retinal afferents indicating their retinal origin. The responsiveness of the cells for center stimuli of different wavelengths and during illumination of the receptive field center or the outer surround was determined. Continuous outer surround illumination altered maintained discharge rate (MDR), sensitivity and gain of P-LGN and retinal ganglion cells in the same way and empirically not distinguishable from direct illumination of the receptive field. Responses to surround flashes showed the same dependence on spectral composition as those to center flashes. Adaptation and excitation caused by outer surround illumination (inner diameter 5 degrees, outer diameter 20 degrees) were, in the average, ten times weaker than those exerted by light of the same spectral composition shone directly into the receptive field. Surround effects decreased proportional to r-2. Excitation by outer surround flashes was reduced by adaptation of the receptive field center in the same manner as responses to center flashes. The findings indicate that outer surround light has a direct excitatory and adaptive effect on the excitatory or inhibitory cones feeding into the receptive field. This indicates that straylight from the surround into the center could be responsible for the adaptive and excitatory effects of surround illumination. The straylight fraction from the remote surround into the receptive field must be higher, however, than that estimated from the psychophysically determined point spread function. It comes closer to earlier direct straylight measurements in excised eyes, but may be enhanced by chromatic aberration. If a surround of excitatory colour is flashed simultaneously with an excitatory center stimulus, additivity of center and surround excitation is observed only at low center intensities, while at higher center intensities the gain for center excitation is reduced similar to adaptive gain control. This could be explained by lateral interaction through horizontal connections in the retina, which decays within seconds, while adaptation of the cones feeding into the receptive field center is fully effective only after about 3 s.(ABSTRACT TRUNCATED AT 400 WORDS)     

Uptake of oxidized lipids by the scavenger receptor CD36 promotes lipid peroxidation and dysfunction in CD8+ T cells in tumors

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Ki-67 Expression is a Prognostic Marker of Prostate Cancer Recurrence after Radical Prostatectomy

Purpose

We assessed the cellular proliferation of clinically localized prostate cancer by immunohistochemistry using the monoclonal antibody MIB to Ki-67 antigen in an attempt to identify associations between proliferative indexes and disease progression following radical prostatectomy.

Materials and Methods

Ki-67 proliferative antigen was evaluated using MIB 1 monoclonal antibody in archival paraffin embedded radical prostatectomy specimens from 180 patients followed for 1 to 9 years (mean 4.4). The percentage of tumor nuclei expressing Ki-67 antigen was measured and assigned an MIB 1 score (none or rare-negative, 1+-low score and 2 to 4+-high score) and analyzed for prostate specific antigen, stage, age, race, grade and serological recurrence postoperatively.

Results

There was a significant association between MIB 1 score and nuclear grade (p less than 0.001), Gleason score (p less than 0.001) and pathological stage (p = 0.01). Patients with a high MIB 1 score had earlier progression and a lower 5-year recurrence-free survival rate (44 percent) than those with negative MIB 1 scores (71 percent, p less than 0.001). In multivariate Cox regression analysis with backward elimination, pathological stage (p less than 0.01), pretreatment prostate specific antigen (p = 0.04) and MIB 1 score (p = 0.05) were statistically significant predictors of disease-free survival, and patients with a high MIB 1 score were 3.1 times as likely to have recurrence as those with a negative score. Controlling for stage, patients with organ confined disease and a high MIB 1 score had a lower 5-year disease-free survival rate (68 percent) than those with a low MIB 1 score (95 percent, p greater than 0.01).

Conclusions

Proliferative activity as measured by the Ki-67 proliferative antigen, MIB 1, appears to be a prognostic marker of recurrent prostate cancer after radical prostatectomy.     

Inhaled nitric oxide reduces pulmonary vascular resistance more than prostaglandin E(1) during heart transplantation

Heart transplantation in patients with increased pulmonary vascular resistance is often associated with postbypass right heart failure. We therefore compared the abilities of prostaglandin E(1) (PGE(1)) and inhaled nitric oxide to reduce pulmonary vascular resistance during heart transplantation. Patients undergoing orthotopic heart transplantation for congestive heart failure were randomly assigned to either a PGE(1) infusion at a rate of 8 ng. kg. (-1)min(-1) starting 10 min before weaning from cardiopulmonary bypass (CPB) (n = 34) or inhalation of 4 ppm nitric oxide starting just before weaning from CPB (n = 34). Both treatments were increased stepwise, if necessary, and were stopped 6 h postoperatively. Hemodynamic values were recorded after the induction of anesthesia, 10 and 30 min after weaning from CPB, and 1 h and 6 h postoperatively. Immediately after weaning from CPB, pulmonary vascular resistance was nearly halved in the nitric oxide group but reduced by only 10% in the PGE(1) group. Pulmonary artery pressure was decreased approximately 30% during nitric oxide inhalation, but only approximately 16% during the PGE(1) infusion. Six hours after surgery, pulmonary vascular resistance and pulmonary artery pressure were similar in the two groups. The ratio between pulmonary vascular resistance and systemic vascular resistance was significantly less in the nitric oxide patients at all postbypass times. In contrast, the pulmonary-to-systemic vascular resistance ratio increased approximately 30% in the patients given PGE(1). Cardiac output, heart rate, mean arterial pressure, right atrial pressure, and pulmonary wedge pressure did not differ between the groups. Weaning from CPB was successful in all patients assigned to nitric oxide inhalation; in contrast, weaning failed in six patients assigned to PGE(1) (P = 0.03). IMPLICATIONS: Nitric oxide inhalation selectively reduces pulmonary vascular resistance and pulmonary artery pressure immediately after heart transplantation which facilitates weaning from cardiopulmonary bypass.