Gas-chromatographic analysis of busulfan for therapeutic drug monitoring

The development and validation of a gas chromatographic assay method for determination of total and free busulfan concentrations in human plasma for pharmacokinetic studies is reported. 1,6-Bis(methanesulfonyloxy)hexane, the internal standard, and a potential metabolite, 3-hydroxysulfolane, were synthesized. Plasma and plasma ultrafiltrate samples containing busulfan and internal standard were extracted with ethyl acetate and derivatized with 2,3,5,6-tetrafluorothiophenol prior to gas chromatographic determination. The⁶³Ni electron-capture detector provided a limit of detection of 0.0600 g/ml with a limit of quantitation of 0.100 g/ml busulfan in biological samples. Calibration curves were linear from 0.100 to 3.00 g/ml in plasma (500 l) and 0.100 to 2.00 g/ml in plasma ultrafiltrate (100 l). Extraction and derivatization yields ranged from 78.4% to 89.6% and 56.0% to 71.3%, respectively. Specificity of this assay for busulfan in the presence of its potential metabolites was demonstrated. Also, plasma samples containing co-administered drugs gave no response under these conditions. Clinical samples obtained following administration of a 1 mg/kg oral busulfan dose demonstrate the applicability of this method to analysis of total and free plasma concentrations.This work was supported in part by Burroughs Wellcome Inc. and the British Columbia Cancer Agency.     

Intensive chemotherapy with cyclophosphamide, carmustine, and etoposide followed by autologous bone marrow transplantation for relapsed Hodgkin's disease

Fifty-six consecutive patients with advanced Hodgkin's disease considered incurable with further conventional chemotherapy were entered into a protocol that included high-dose cyclophosphamide (7.2 g/m2), carmustine (BCNU; 0.6 g/m2), and etoposide (VP16-213; 2.4 g/m2) (CBV) followed by autologous bone marrow transplantation (BMT). Prior combination chemotherapy had failed in all the patients, and all but five had been previously treated with both mechlorethamine, vincristine, procarbazine, and prednisone (MOPP) and doxorubicin, bleomycin, and vinblastine with or without dacarbazine (ABV[D]). Thirty-four eligible patients received short-course conventional chemotherapy and/or involved-field radiotherapy before CBV. However, formal restaging was not performed after these conventional therapies; ie, the therapies were not used to select responding patients for transplantation, and all who received such therapy subsequently received CBV and autologous marrow grafts. Forty-four patients (80%; 95% confidence interval [CI], 69% to 91%) achieved a complete response after CBV and BMT. Performance status at protocol entry and the use of conventional cytoreduction therapy before CBV correlated with response. Median follow-up is now 3.5 years (range, 2.5 to 5.0 years). Kaplan-Meier estimates for overall and event-free survival 5 years after transplant are 53% (95% CI, 37% to 67%) and 47% (95% CI, 33% to 60%), respectively. In a univariate analysis, patients with a normal performance status and those without constitutional ("B") symptoms at protocol entry had an improved overall and event-free survival. In a multivariate analysis, only a normal performance status remained significant. Disease progression occurred in 17 patients at an actuarial rate of 39% (95% CI; 26% to 56%) and occurred at previous sites of active disease in all but one patient; our analysis did not identify prognostic factors for progression. Toxic deaths, caused by either neutropenic sepsis or interstitial pneumonitis (IP), occurred in 12 patients (21%; 95% CI, 10% to 32%). CBV with autologous marrow support can produce durable remissions in a substantial number of patients with Hodgkin's disease considered incurable with conventional measures. Regimen refinements may even further improve the therapeutic index of BMT in this malignancy.     

Congenital skull fracture as a presentation of Menkes disease

We report the rare presentation of Menkes disease with a congenital skull fracture, intracerebral bleeding, and seizures. The diagnosis was made at 3 months of age based on the characteristic features of the syndrome, by which time the child experienced uncontrollable seizures. Following progressive neurodegeneration, death occurred at 3 years of age. The prognosis in Menkes disease is dependent on early copper-histidine therapy. Effective treatment has led to children surviving into adulthood. Diagnosing the syndrome during the neonatal period is difficult. There are no published reports of congenital skull fracture as a presenting sign of Menkes disease. It is concluded that Menkes disease should be considered in any child who presents with congenital skull fracture as early diagnosis and treatment significantly improve the outcome.     

Sonographic evaluation of the normal developmental anatomy of fetal cerebral ventricles: I. The frontal horn

A prospective ultrasound study was conducted in 179 normal pregnant women with gestational ages ranging from 15-40 weeks. Several biometric measurements were obtained throughout pregnancy, including the cerebrofrontal horn distance of the lateral ventricle, the frontal hemispheric width, and the calculated ratio of cerebrofrontal horn distance/hemispheric width. Curvilinear relationships were found between cerebrofrontal horn distance and gestational age (R2 = 0.597; P less than .0001) and between cerebrofrontal horn distance and the biparietal diameter (R2 = 0.618; P less than .0001). In addition, a curvilinear relationship existed between cerebrofrontal horn distance/hemispheric width ratio and gestational age (R2 = 0.492; P less than .0001) and biparietal diameter (R2 = 0.930; P less than .0001). These data represent a comprehensive characterization of normal growth of the fetal frontal horns. They provide a method by which variations from the norm can be assessed and early prenatal diagnosis of developmental anomalies of the fetal ventricular system can be made.     

Cooperative interaction between mutant p53 and des(1-3)IGF-I accelerates mammary tumorigenesis

Mammary tumorigenesis was analysed in transgenic mice which overexpress des(1-3)hIGF-I (WAP-DES) and/or a mutant form of p53 (p53172R-H). Nonlactating, multiparous WAP-DES mice exhibited hyperplastic lesions termed mammary interepithelial neoplasia (MIN) which constitutively expressed WAP-DES. By 23 months of age, 53% of the WAP-DES mice developed mammary adenocarcinomas. A 75% reduction in both apoptosis and proliferation was observed in the normal mammary glands of WAP-DES mice. Mammary tumor incidence in WAP-DES/p53 bitransgenic mice was similar to that of WAP-DES and 2 - 3-fold greater than that of nontransgenic and p53172R-H females. Tumor latency, however, was reduced by 8 months in bitransgenic mice as compared to mice of the other three genotypes. Aneuploidy was frequently observed in tumors from bitransgenic and p53172R-H mice, but not from mice expressing only the WAP-DES transgene. Expression of IGFBP3 was elevated in tumors from WAP-DES, but not bitransgenic mice, indicating an alteration in the p53/IGF-I axis. These studies indicate that overexpression of des(1-3)hIGF-I increases the frequency of MIN and stochastic mammary tumors and that the appearance of tumors displaying genomic instability is accelerated by mutant p53172R-H. Oncogene (2000) 19, 889 - 898.     

An antibody assay predictive of BRCA1 mutations in ovarian tumors and normal tissue

To determine whether immunohistochemistry can identify BRCA1 mutations, immunohistochemical (IH) analysis was undertaken on paraffin sections of paired ovarian cancer and normal tissue using antibodies against both terminal regions of the BRCA1 protein. Ten patients at risk for BRCA1 mutations were studied. The results of BRCA1 mutation analysis and IH were compared. In tumor, IH correctly identified the presence or absence of loss of heterozygosity in all specimens. In all uninvolved specimens, IH correctly identified the presence or absence of a germline mutation. The sensitivity, specificity, positive and negative predictive values were 100% suggesting promise as a rapid and inexpensive screen.     

Treatment of Acute Promyelocytic Leukemia in Patients Presenting at Vancouver General Hospital from 1983 to 1992

Between 6/83 and 8/92, 23 of 361 patients (6.4%) presenting at Vancouver General Hospital with acute myelogenous leukemia had acute promyelocytic leukemia (APL). Treatment plan was: 1) induction with high-dose cytosine arabinoside and an intercalator; and 2) consolidation with allogeneic bone marrow transplantation (BMT) for those aged ≤ 50 years with a sibling donor or repeat of induction for the others. Complete remission (CR) was achieved in 20 patients (87%). Eleven patients in CR were eligible for allogeneic BMT; 4 were considered unsuitable, 2 refused, and 5 underwent this treatment-1 died of acute graft-versus-host disease, 1 relapsed and 3 are leukemia-free and well 1.6, 3.3 and 3.9 years after diagnosis. Fifteen patients did not undergo allogeneic BMT in CR; 4 received no further treatment and all died, 2 relapsed before consolidation therapy and both died, 1 underwent autologous BMT and died of complications, and 8 received consolidation treatment as planned--1 died of sepsis, 2 relapsed and 5 are leukemia-free and well 1.0, 3.8, 4.5, 4.9 and 8.5 years after diagnosis. The actuarial overall survival for all 23 patients was 38% (95% confidence interval [CI] 18-57%). The actuarial 2-year leukemia-free survival was 60% (95% CI 20-85%) for the 8 patients who underwent consolidation chemotherapy as planned and 53% (95% CI 68-86%) for the 5 patients who underwent allogeneic BMT in CR. These results suggest that patients with APL who are able to undergo consolidation chemotherapy have a relatively good prognosis and allogeneic BMT may reasonably be held in reserve for salvage therapy.     

Does intensive glycemic control in diabetic pregnancies result in normalization of other metabolic fuels?

Intensive treatment of insulin-dependent diabetes mellitus during pregnancy often normalizes plasma glucose levels. However, it is unclear whether this adversely affects other metabolic fuels that are essential to normal fetal growth and development. Metabolic studies were conducted after the subjects ingested a standardized mixed meal during each trimester in 7 normal and 15 insulin-dependent diabetic pregnant women. The latter were treated with continuous subcutaneous insulin infusion or multiple injections, which were adjusted to achieve strict glucose control throughout pregnancy. Insulin, alanine, branched-chain amino acids, triglycerides, free fatty acids, and ketones were measured every 15 to 30 minutes before a standardized breakfast and for 150 minutes after the breakfast. Patients with insulin-dependent diabetes mellitus were studied while they received their unusual insulin dosages. Fasting glucose levels (87 +/- 7 mg/dl) and glucose levels 150 minutes after the meal (112 +/- 11 mg/dl) were near normal. However, normoglycemia was achieved at the expense of increased plasma insulin levels (area under insulin response curves, p less than 0.01, vs nondiabetic curves). Nevertheless, fasting and post-prandial plasma branched-chain amino acids, alanine, and free fatty acids were similar in both groups. Fasting cholesterol, triglyceride, and ketone levels were also normalized. We conclude that normalization of circulating amino acids and lipids in conjunction with correction of hyperglycemia may contribute to favorable outcomes in infants of intensively treated diabetic mothers.     

Interference in assays for hydralazine in humans by a major plasma metabolite, hydralazine pyruvic acid hydrazone.

The present study showed that published spectrophotometric and GLC methods for hydralazine in plasma do not distinguish between the drug and a major plasma metabolite, hydralazine pyruvic acid hydrazone. These methods involve the acid treatment of the sample, which hydrolyzes that hydrazone back to hydralazine. A specific GLC assay for the hydrazone was developed and involves its selective extraction from plasma and transformation to 3-trifluoromethyl-s-triazolo[3,4-a]phthalazine. This derivative could be sensitively measured by GLC using an electron-capture detector. With this procedure, it was shown that most "apparent hydralazine" in plasma is the hydrazone, which forms rapidly from hydralazine and endogenous pyruvic acid. Previous work indicated that the hydrazone was inactive when administered intravenously to rabbits.