Effects of tumor type, degree of obesity, and chemotherapy regimen on chemotherapy dose intensity in obese cancer patients.

The American Society of Clinical Oncology recently published a Clinical Practice Guideline entitled "Appropriate Chemotherapy Dosing for Obesity Adult Patients with Cancer." The panel recommended that full weight (actual weight)-based cytotoxic chemotherapy doses are used to treat obese patients with cancer, particularly when the goal of treatment is cure. However, no study has examined dosage calculation methods used for obese cancer patients in Japan. Here, we retrospectively studied the relationships between chemotherapy dose intensity, the occurrence of adverse events, and treatment outcomes in obese patients undergoing chemotherapy. Patients were divided into two groups: the actual BW group (BWg) was composed of patients receiving dosage amounts calculated using their actual BW (n = 64), and the ideal BWg was composed of patients receiving dosage amounts calculated using their ideal BW (n = 41). There were significant differences in the incidence of Grade 3/4 hematological toxicity in the actual and ideal BWg in solid tumor patients, but not in patients with hematological malignancies. In solid tumor patients with ≥30 body mass index (BMI), the incidence of Grade 3/4 hematological toxicity was significantly lower in the ideal BWg than in the actual BWg. Particularly, in patients with complications, incidence of Grade 4 hematological toxicity was significantly higher in the actual BWg than in the ideal BWg. These results suggest that the tumor type, degree of obesity, complications, and choice of chemotherapy regimen should be considered when determining chemotherapy dosage for obese patients.

ELISA for the quantification of pilsicainide.

A sensitive and specific ELISA for an antiarrhythmic drug, pilsicainide, was developed, which is capable of measuring as low as 1.6 ng/ml. Anti-pilsicainide antibody was obtained by immunizing rabbits with pilsicainide conjugated with bovine serum albumin using diazotized N-(3-amino-2,6-dimethylphenyl)-8-pyrrolizidinylacetamide (3-aminopilsicainide). Enzyme labeling of pilsicainide with beta-D-galactosidase was similarly performed using a diazotized 3-aminopilsicainide. Cross-reactivity data showed that the antibody well recognizes both the aromatic ring and the pyrrolizidine moieties, and thus specific enough to the structure of pilsicainide. The values for the pilsicainide concentrations detected using this assay were comparable with those detected using HPLC. There was a good correlation between the values determined by the two methods. Moreover, the ELISA was about 30-fold more sensitive in detecting pilsicainide at lower concentrations. Using this assay, drug levels were easily measured in the serum of rabbits after oral administration of pilsicainide at a single dose of 1 mg/kg. The ELISA should be a valuable tool in therapeutic drug monitoring (TDM) and pharmacokinetic studies of pilsicainide.

Determination of topotecan by ELISA.

A highly sensitive ELISA for the determination of (s)-9-dimethylaminomethyl-10-hydroxy-camptothecin (topotecan) capable of measuring as low as 80 pg/ml was developed. Anti-topotecan antibody was obtained by immunizing rabbits with topotecan conjugated with bovine serum albumin using diazotized m-aminobenzoic acid as a cross-linker. Enzyme labeling of topotecan with beta-D-galactosidase was performed by utilizing another cross-linker, N-(4-diazophenyl)maleimide. The specificity of this ELISA appears to be primarily toward the lactone moiety of topotecan, showing a very slight cross-reactivity with the lactone opened-ring of topotecan. The values for the topotecan concentrations detected using this assay were comparable with those detected using HPLC. There was a good correlation between the values determined by the two methods. These findings suggest that this ELISA can detect the natural amounts of the lactone form. Using this assay, drug levels were easily determined in the blood and urine of rats for 5 h after i.v. administration of topotecan at a single dose of 1 mg/kg. The sensitivity and specificity of the ELISA should provide a useful tool for developing pharmacokinetic and pharmacodynamic studies of topotecan.

Development of ELISAs for irinotecan and its active metabolite SN-38.

Two highly sensitive and specific enzyme-linked immunosorbent assays (ELISAs) for the determination of 7-ethyl-10-[4-(1-piperidino)-1-piperidino]carbonyloxy-camptothecin (irinotecan) and 7-ethyl-10-hydroxycamptothecin (SN-38), an active metabolite of irinotecan, were developed, which are capable of measuring as low as 16 and 160 pg of each drug/ml, respectively. Anti-irinotecan antibody was obtained by immunizing rabbits with irinotecan conjugated with mercaptosuccinyl bovine serum albumin (MS.BSA) using N-(4-diazophenyl)maleimide (DPM) as a heterobifunctional coupling agent. An enzyme marker was similarly prepared by coupling irinotecan with horseradish peroxidase (HRP) via DPM. This ELISA for irinotecan was specific for irinotecan and showed almost no cross-reactivity with its active metabolite SN-38. Anti-SN-38 antibody was obtained by immunizing rabbits with SN-38 conjugated with BSA using the N-succinimidyl ester method. An enzyme marker was prepared by coupling SN-38 with HRP employing DPM. The ELISA for SN-38 was specific to SN-38 and showed a very slight cross-reactivity with irinotecan (0.08%). Using the 2 assays, we reconfirmed the rapid metabolite of irinotecan with rat serum. The 2 ELISAs may be a valuable tool for studies of the pharmacokinetics and pharmacodynamics of these drugs.

A highly sensitive ELISA for the quantification of polymyxin B sulfate in human serum.

A highly sensitive ELISA for the determination of polymyxin B sulfate (PMB) was developed which is capable of measuring as low as 32 pg/ml. Anti-PMB antibody was obtained by immunizing rabbits with PMB conjugated with mercaptosuccinyl bovine serum albumin (MS. BSA) using N-(gamma-maleimidobutyryloxy) succinimide (GMBS) as a heterobifunctional coupling agent. An enzyme marker was similarly prepared by coupling PMB with horseradish peroxidase (HRP) employing GMBS. This ELISA showed very low reactivity with the PMB analogue, polymyxin E (0.05%). The values for PMB concentration detected by this assay were comparable with those detected by the bioassay. Moreover, the ELISA was about 10,000 times more sensitive in detecting PMB at lower concentrations. Serum PMB concentration after the oral administration of a PMB tablet to human subjects was determined by the ELISA. PMB was rapidly absorbed from the gastrointestinal tract after the administration, then slowly decreased. These results indicate that the ELISA may be a valuable tool for studies of the pharmacokinetics and pharmacodynamics of the anti-endotoxin drug, PMB.

Localization of parathyroid glands using technetium-99m-tetrofosmin imaging.

UNLABELLED: Preoperative localization of hyperactive parathyroid glands is useful to minimize operative time and reduce patient morbidity. This investigation compared the sensitivity of radionuclide imaging with 99mTc tetrofosmin with that of ultrasonography and magnetic resonance (MR) imaging in patients with hyperparathyroidism. METHODS: Twenty-six patients with primary (n = 7) or secondary (n = 19) hyperparathyroidism were imaged with 99mTc tetrofosmin, ultrasound and MR imaging of the neck and thorax to localize the lesions. The presence of hyperparathyroidism was identified by an intact parathyroid hormone in vitro assay. The parathyroid/normal thyroid tissue activity ratio was calculated for all patients with evidence of an abnormality on tetrofosmin images. Pathological findings were compared with the results of imaging in 18 of the 26 patients who underwent parathyroidectomy. RESULTS: Technetium-99m tetrofosmin scans demonstrated focal uptake in 46 glands of 26 patients. The uptake was categorized as slight in 78.3% (36/46) and intense (parathyroid/normal thyroid tissue activity ratio, > 1.4) in 21.7% (10/46). Ultrasonography and MR imaging identified 44 and 47 glands, respectively, in these patients. Eleven of the 18 patients who underwent parathyroidectomy within 1 mo after tetrofosmin imaging had hyperplastic glands, while 7 had parathyroid adenomas. Tetrofosmin imaging successfully localized 7 of 7 (100%) adenomas and 27 of 37 (73.0%) hyperplastic glands. The sensitivities of each technique for localizing abnormal parathyroid glands were 77.3% (34/44) for tetrofosmin imaging: 68.2% (20/44) for ultrasonography: and 68.2% (30/44) for MR imaging. Technetium-99m tetrofosmin uptake ratio in the 18 patients with surgical exploration was not proportional to several oxyphil cells. CONCLUSION: Technetium-99m tetrofosmin parathyroid imaging may be useful for localizing abnormal glands in patients with primary and secondary hyperparathyroidism. The sensitivity of 99mTc tetrofosmin parathyroid imaging was high as compared to ultrasonography or MR imaging. The prolonged retention of tetrofosmin may not depend on the number of mitochondria-rich oxyphil cells.

Screening of polyacetylenic alcohols in crude drugs using the ELISA for panaxytriol.

Polyacetylenic alcohols such as panaxytriol, panaxynol and panaxydol isolated from the roots of Panax ginseng C. A. MEYER have antiproliferative activity against various cultured tumor cells. Anti-panaxytriol antibody was obtained by immunizing rabbits with panaxytriol-bovine serum albumin conjugates. Although the antibody reactivity was directed mainly toward panaxytriol, there was a slight cross-reactivity with other polyacetylenic compounds. The antibody was, therefore, used for screening a large number of crude drugs for polyacetylenic compounds such as panaxytriol. Methanol-extracts from 31 crude drugs were examined. Significant reactivity was observed in 15 methanol-extracts from Aralieaceae, Compositae and Umbelliferae as reported by other investigators. Three out of the 15 crude drugs were selected for determination of the potent cross-reactive compounds. Four kinds of cross-reactive compounds were isolated by silica gel column chromatography, monitoring each fraction using the enzyme-linked immunosorbent assay (ELISA). Among them, panaxynol and heptadeca-1,8-diene-4,6-diyne-3,10-diol were identified from Saposhnikoviae Radix. Falcarindiol was newly identified from Peucedani Radix. A new polyacetylenic alcohol, 9,10-epoxy-16-hydroxy-octadeca-17-ene-12,14-diyne-1-al, was also isolated from Foeniculi Fructus. All these polyacetylenic alcohols inhibited the growth of a human gastric adenocarcinoma cell line, MK-1 cells, in a dose-dependent manner. These results indicate that the antibody against panaxytriol is an effective tool for "screening" antiproliferative polyacetylenic compounds.

A highly sensitive enzyme-linked immunosorbent assay (ELISA) for antitumor polyacetylenic alcohol, panaxytriol.

A new type of antitumor polyacetylenic alcohol, panaxytriol, was isolated from the roots of Panax ginseng C. A. Meyer. A highly sensitive enzyme-linked immunosorbent assay (ELISA) for the determination of panaxytriol was developed, which is capable of measuring as low as 25.6 pg/ml. Anti-panaxytriol antibody was obtained by immunizing rabbits with panaxytriol conjugated with bovine serum albumin using the N-succinimidyl ester method. An enzyme marker was similarly prepared by coupling panaxytriol with horseradish peroxidase. The specificity of this ELISA seems to be primarily toward both the glycol moiety and the diacetylene moiety of the panaxytriol, showing a slight cross-reaction with the other panaxytriol analogues which are structurally different only in C-9,10 positions, but no cross-reaction with the 1,2-decanediol or 3-nonyn-1-ol. The values for panaxytriol concentration detected by this assay were comparable with those detected by the gas chromatography method. The ELISA was about 5000 times more sensitive in detecting panaxytriol. Using this assay, panaxytriol levels were easily determined in the blood of rats. The ELISA may be a valuable tool for studies of the biological and pharmacological properties of the polyacetylenic alcohol, panaxytriol.

The first specific antibody against cytotoxic polyacetylenic alcohol, panaxynol.

Antitumor polyacetylenic alcohol, panaxynol, was isolated and purified from a powder of the root of Panax ginseng C.A. Meyer. Panaxynol inhibited the growth of various kinds of cultured tumor cell lines in a dose-dependent manner. In this paper we demonstrated the first specific antibody production against panaxynol. Anti-panaxynol antibody was elicited in rabbits by immunization with panaxynol hemisuccinate-bovine serum albumin conjugate (panaxynol hemisuccinate-BSA conjugate). An enzyme immunoassay (EIA) for the determination of panaxynol was established using a double-antibody technique. The EIA was highly specific against panaxynol although the antibody showed a minimal cross-reactivity with other types of polyacetylenic alcohol, i.e. panaxydol (12.0%) and panaxytriol (0.77%). Panaxynol at a concentration as low as 6.4 ng/ml can be detected. Using this assay we reconfirmed the rapid consumption of panaxynol by target tumor cells in an in vitro-culture system. The anti-panaxynol antibody may be a valuable tool for studies of the biological properties of polyacetylenic compounds.

Cytotoxic activity of polyacetylene compounds in Panax ginseng C. A. Meyer.

The effects of the three polyacetylene compounds, panaxynol, panaxydol and panaxytriol, on in vitro-cell growth were studied. These compounds are much different in their water-solubility. In order to increase water-solubility, solid complexes of polyacetylene compounds with alpha-cyclodextrin (CD) were prepared. Accurate concentrations of the active compounds in a culture medium were determined by gas chromatography. All of these CD-complexes inhibited the growth of various kinds of cultured cell lines in a dose-dependent fashion. The cell growth inhibitory activity of these complexes was much stronger against malignant cells than against normal cells. A continuous contact between the compounds and target cells was not necessarily required for growth inhibition. And the inhibition was cytotoxic at high concentrations and cytostatic at low concentrations. These findings indicate that these polyacetylene compounds' mode of action is more dose-dependent than time-dependent. The panaxynol, panaxydol and panaxytriol contents in red ginseng powder were 250, 297 and 320 micrograms/g, respectively.

Correlation between the saliva and free serum concentration of phenobarbital in epileptic children.

Twenty epileptic children taking phenobarbital (PB) were evaluated for the concentration of PB in their saliva (Sa), total serum concentration (TS), free serum concentration (FS), and also the pH of the saliva samples. The Sa/TS ratio was 43.0 +/- 5.2% (mean +/- SD), and showed a close relationship between the two (r = 0.98). The free serum concentrations for PB were also observed to be closely correlated to the saliva concentration (r = 0.99), as well as to the total serum concentration, with the FS/TS ratio being 45.0 +/- 5.6%. However, no obvious relationship between the salivary pH and the Sa/TS ratio for PB was observed. This suggested the usefulness of monitoring the PB saliva concentrations in clinical management of epilepsy.

Further studies of lipid peroxidation in human paraquat poisoning.

In patients with subacute toxic reactions from paraquat poisoning (death within 11 to 41 days), the extent of lipid peroxidation, expressed as serum malondialdehyde level, was 2.7-fold higher (12.33 +/- 4.42 nmole/mL) before pulmonary fibrosis than that in normal controls (4.55 +/- 1.23 nmole/mL). The extent of lipid peroxidation in patients with acute toxic reactions (death within one to three days) was not elevated; these patients died of pulmonary edema and hemorrhage (acute respiratory distress), liver failure, renal failure, and adrenal necrosis. Remarkable high levels of paraquat (greater than 5 mg/L) were found in the urine, serum, and tissues of patients with acute toxic reactions; a small amount of paraquat was found in the serum or urine of patients with subacute toxic reactions five to 11 days after ingestion. Patients who survived had no elevation in lipid peroxidation. Administration of vitamin E (100 to 4,000 mg/day from the first hospital day) had no effect on survival.