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At least 1,693 records · Page 94Linked to original sources
PubMed2004

Phase I and pharmacokinetic study of irofulven administered weekly or biweekly in advanced solid tumor patients.

PURPOSE: We performed a Phase I and pharmacokinetic study to determine the maximum tolerated dose of irofulven (6-hydroxymethylacylfulvene; MGI-114, MGI PHARMA, Inc.), administered in intermittent weekly schedules in patients with advanced solid tumors. EXPERIMENTAL DESIGN: Three schedules were tested: A, days 1, 8, and 15 every 4 weeks; B, days 1 and 8 every 3 weeks; C, days 1 and 15 every 4 weeks. Drugs were administered as 5- and 30-min (schedules B and C) infusions. Dose levels of 10, 12, and 14 mg/m(2)/week were explored. RESULTS: Ninety-nine patients received 256 cycles. Fifteen of 74 patients evaluable for maximum tolerated dose experienced 16 dose-limiting toxicities (5 of 17 patients on schedule A, 2 of 25 on schedule B, and 8 of 32 on schedule C), principally treatment delay for thrombocytopenia. Schedule A was considered unsuitable because of frequent thrombocytopenia and treatment discontinuations. Twenty-three percent of the overall population (22 patients with grade 1-2, and 1 patient with grade 3), including 37% of patients on dose level 3, experienced unexpected dose-limiting visual toxicity, which included color perception and visual field alterations linked to retinal cone cell toxicity; the visual toxicity had an early onset, was mostly reversible, and was related to higher dose per infusion. Safety profiles were similar for 5- and 30-min infusions. The relationships between dose and area under the plasma concentration-time curve and maximum plasma concentration were linear for both 5- and 30-min infusions in the 78 patients evaluated for pharmacokinetics. The area under the plasma concentration-time curve and clearance were comparable between infusion durations. Responses included one complete (ovarian), one partial (renal), and seven disease stabilizations lasting >4 months. CONCLUSIONS: We recommend doses of 18 mg/m(2)/infusion for schedule B and 24 mg/m(2)/infusion for schedule C, limited to 0.55 mg/kg and a total dose of 50 mg/infusion, administered over 30-min.

Adult↗
PubMedDate not supplied

Blue-on-yellow perimetry to evaluate S cone sensitivity in diabetics.

Blue-on-yellow (B/Y) perimetry was performed on 31 patients with non-insulin-dependent diabetes mellitus to study the loss of sensitivity to short wavelengths. Of these patients, 21 were without retinopathy (NDR) and 10 had early background retinopathy (SDR). Eleven normal subjects served as controls. The results were compared to white-on-white (W/W) perimetry. Foveal sensitivity determined by B/Y and W/W perimetry showed no significant difference between NDR, SDR and normals. However, the mean sensitivity in the central 30-degree area and that in the upper half of the central 20- to 30-degree concentric circular field were significantly decreased in B/Y perimetry in SDR patients (p < 0.05, p < 0.01, respectively). No significant sensitivity loss was detected in the W/W test. We conclude that there is a blue cone system sensitivity loss in the central 30-degree area, particularly in the upper half of the visual field and the paracentral area in diabetic patients with early background retinopathy.

Adult↗
PubMed1984

Cone mechanisms and their colour-opponent interaction in monkeys and cat.

Cone mechanisms and colour opponency were investigated in 108 recordings from tonic ganglion cells of the rhesus monkey retina and 265 recordings from ganglion cells of the cat retina. Colour-opponent cells input from short and longer wavelength sensitive cones can be found in both species in about equal proportions (6-8%). Although cells with opponency between middle and long-wavelength sensitive cones are very common in monkey (49%), they are rare in the cat (4%); usually the opponency of the latter can only be detected with strong chromatic adapting lights suppressing the dominant mechanism, while in monkey colour opponency is usually revealed under neutral adapting conditions. These differences between both species in processing chromatic stimuli can help to explain certain types of colour vision deficiencies in man.

Animals↗
PubMed1980

Different endocrinal and hemodynamic response patterns to various noxious stimuli.

Various endocrinal and hemodynamic parameters of 5 patients during a cardiovascular investigation were assessed in and after the adaptation phase, and together with the following noxious stimuli in random order: reading a confusion color chart based on the principle of interference in color perception, cold pressure test, isometric stress with a hand ergometer. The following parameters were assessed: arginine vasopressin, renin, heart rate, systolic, diastolic and mean arterial blood pressure, cardiac index, stroke volume and total peripheral resistance in the adaptation phase and during the various psychological and physical demand situations as well as 5 min afterwards. The results show that the organism reacts to the various stimuli with endocrinal and hemodynamic responses in a differentiated pattern in contrast to the model of the "alarm reaction" which, according to Cannon, states a homogeneous directed response with regard to the various parameters.

Adolescent↗
PubMed1994

Field quadrant asymmetry in perimetric thresholds: results of normal and red-green-deficient persons.

Perimetric thresholds of normal and red-green-deficient persons were measured using three colored test stimuli and a low-intensity white background. Meridians of 45 degrees, 135 degrees, 225 degrees and 315 degrees were tested within 30 degrees peripherally. A statistically significant sensitivity difference between the quadrants was found at eccentricities of 5-30 degrees from the center with the highest sensitivity in the lower temporal field and the lowest one in the upper nasal field, this difference being slightly larger when tested with red (615 nm) or violet (443 nm) light compared with blue-green (497 nm) test light. No difference in the field quadrant sensitivity was observed between the results of the series of normal and red-green-deficient persons.

Adolescent↗