Quantitative assessment of skin disorders induced by panitumumab: a prospective observational study.

PURPOSE: Acneiform rash is frequently observed in patients undergoing cancer treatment with anti-epidermal growth factor receptor (EGFR) antibody drugs and can often necessitate treatment discontinuation. However, the specific changes in skin parameters resulting from anti-EGFR antibody drug administration are poorly understood. Therefore, this study aimed to longitudinally and quantitatively evaluate the changes in skin parameters (transepidermal water loss [TEWL], hydration level, and sebum level) caused by anti-EGFR antibody drugs and investigate their potential as control markers for skin disorders. METHODS: This prospective study included 12 patients with colorectal cancer who received anti-EGFR antibody drugs for the first time. The assessment items included the grade of acneiform rash and skin parameters (TEWL, hydration level, and sebum level), which were observed for up to 6 weeks after administration of the medication. RESULTS: The enrolled patients were classified into two groups based on the grade of acneiform rash caused by anti-EGFR antibody drugs: "Grade 1 and lower," and "Grade 2 and higher." The skin parameters were compared between these groups. The results showed that in the "Grade 2 and higher" group, TEWL in the face (at week 2 of administration), chest (baseline, weeks 2 and 6 of administration), and back (at week 2 of administration) were significantly higher than those in the "Grade 1 and lower" group. However, the two groups showed no significant differences in hydration or sebum levels at any time point. CONCLUSION: TEWL can serve as a marker for acneiform rashes induced by anti-EGFR antibody drugs during cancer treatment.

Analysis of serotonin concentrations in human milk by high-performance liquid chromatography with fluorescence detection.

Serotonin (5-hydroxytryptamine, 5-HT) plays an important role in milk volume homeostasis in the mammary gland during lactation; 5-HT in milk may also affect infant development. However, there are few reports on 5-HT concentrations in human breast milk. To address this issue, we developed a simple method based on high-performance liquid chromatography with fluorescence detection (HPLC-FD) for measuring 5-HT concentrations in human breast milk. Breast milk samples were provided by four healthy Japanese women. Calibration curves for 5-HT in each sample were prepared with the standard addition method between 5 and 1000 ng/ml, and all had correlation coefficients >0.999. The recovery of 5-HT was 96.1%-101.0%, with a coefficient of variation of 3.39%-8.62%. The range of 5-HT concentrations estimated from the calibration curves was 11.1-51.1 ng/ml. Thus, the HPLC-FD method described here can effectively extract 5-HT from human breast milk with high reproducibility.

Inhibition by pregnenolone sulfate of nicotinic acetylcholine response in adrenal chromaffin cells.

To evaluate whether pregnenolone sulfate, an abundant neurosteroid in the brain, modulates nicotinic receptor-mediated responses, the effect of pregnenolone sulfate on acetylcholine-induced catecholamine secretion was investigated in cultured bovine adrenal chromaffin cells. Pregnenolone sulfate inhibited acetylcholine-induced catecholamine secretion (IC(50): 27 microM). In addition, pregnenolone sulfate inhibited acetylcholine-induced Na(+) (IC(50): 12 microM) and Ca(2+) (IC(50): 20 microM) influxes. However, pregnenolone sulfate did not inhibit either catecholamine secretion or Ca(2+) influx stimulated by high K(+). Binding of [3H]nicotine to nicotinic receptors was not altered by pregnenolone sulfate. The inhibitory effect on the acetylcholine-induced secretion was insurmountable by increasing acetylcholine concentrations, but was enhanced by decreasing external Na(+) concentrations. These results suggest strongly that pregnenolone sulfate noncompetitively inhibits nicotinic receptor-operated ion channels, thereby suppressing Na(+) influx through the channels and, consequently, attenuates both Ca(2+) influx and catecholamine secretion. Our results further indicate that pregnenolone sulfate may modulate nicotinic receptor-mediated responses in the brain.