Determination of sulfamethazine in milk by biosensor immunoassay.

A biosensor based on surface plasmon resonance (SPR) measurement was developed for use in an immunoassay for detection of sulfamethazine (SMZ) in milk. The biospecific surface was a carboxymethyl dextran-modified gold-surface sensor chip to which SMZ was covalently bound. The assay was based on inhibition of the binding of polyclonal antibodies to immobilized SMZ by SMZ in the sample. The SPR response changed inversely in relation to the antibiotic concentration in the sample. Calibration curves were constructed for SMZ in buffer and in milk at a concentration which included the maximum residue limit (0 to 200 micrograms/kg). The analysis time per sample varied from 8 to 30 min. Different flow rates and antibodies were modified alternatively during the study to assess their influence on the performance of the assay. The active antibody concentration was calculated at approximately 1880 and 180 nM for the antibody anti-SMZ 1 and the antibody anti-SMZ 2, respectively. No cross-reactivity of antibodies with other antibiotics was found. Under optimal conditions, the detection limits in milk for SMZ were 8 and 1.7 micrograms/kg, respectively, for antibody 1 and antibody 2, at a flow rate of 20 microL/min.

DNA-based and alphavirus-vectored immunisation with prM and E proteins elicits long-lived and protective immunity against the flavivirus, Murray Valley encephalitis virus.

The immunogenicity and protective efficacy of DNA-based vaccination with plasmids encoding the membrane proteins prM and E of the flavivirus Murray Valley encephalitis virus (MVE) were investigated. Gene gun-mediated intradermal delivery of DNA encoding the prM and E proteins elicited long-lived, virus-neutralising antibody responses in three inbred strains of mice and provided protection from challenge with a high titer inoculum of MVE. Intramuscular DNA vaccination by needle injection also induced MVE-specific antibodies that conferred resistance to challenge with live virus but failed to reduce virus infectivity in vitro. The two routes of DNA-based vaccination with prM and E encoding plasmids resulted in humoral immunty with distinct IgG subtypes. MVE-specific IgG1 antibodies were always prevalent after intradermal DNA vaccination via a gene gun but not detected when mice were immunised with DNA by the intramuscular route or infected with live virus. We also tested a Semliki Forest virus replicon as vector for a flavivirus prM and E protein-based subunit vaccine. Single-cycle infections in mice vaccinated with packaged recombinant replicon particles elicited durable, MVE-specific, and virus-neutralising antibody responses.

Tamoxifen versus high-dose oral medroxyprogesterone acetate as initial endocrine therapy for patients with metastatic breast cancer: a Piedmont Oncology Association study.

PURPOSE: To determine in a prospective randomized trial whether high-dose orally administered medroxy-progesterone acetate (MPA) was superior to tamoxifen in patients with recurrent or metastatic breast cancer who had received no prior endocrine therapy in either the adjuvant or advanced setting. PATIENTS AND METHODS: Patients initially received either tamoxifen 20 mg/d orally or MPA 1 g/d orally. At the time of disease progression, patients were crossed over to the other regimen. Eligibility required patients to be age > or = 18 years, performance status 0 to 3, and estrogen receptor (ER)- or progesterone receptor (PR)-positive or unknown. RESULTS: One hundred eighty-two eligible patients were entered and 166 were assessable for response. Complete plus partial response rates for tamoxifen and MPA were 17% and 34%, respectively (P = .01). Patients with bone metastases had a significantly higher partial response rate with MPA compared with tamoxifen (33% v 13%). Median time to treatment failure was 5.5 months for tamoxifen and 6.3 months for MPA (P = .48). The median survival duration was 24 months for tamoxifen and 33 months for MPA (P = .09). Multivariate analysis showed that treatment significantly influenced response rate, but not time to treatment failure or survival. After treatment failure following MPA, six of 42 patients (14%) treated with tamoxifen responded, compared with six of 49 (12%) treated with MPA following tamoxifen. Both agents were associated with minimal toxicity, but 35% of patients on MPA gained more than 20 lb as opposed to only 2% on tamoxifen. CONCLUSION: In this trial, initial treatment with MPA of endocrine-naive metastatic breast cancer patients was associated with a significantly higher response rate but not with improvement in time to treatment failure or survival, when compared with initial treatment with tamoxifen. Further randomized trials in patients with bone metastases are warranted to determine if high-dose progestin therapy is superior to tamoxifen in these patients.

Vincristine with high-dose etoposide in advanced breast cancer: a phase II trial of the Piedmont Oncology Association.

Vincristine (VCR) and etoposide (VP-16) have been shown to be synergistic in a murine model, and this combination was studied in a phase II trial. Eligibility required measurable disease, a performance status of 0-2, a life expectancy of > or = 2 months, an interval of at least 3 weeks since the receipt of previous radiation therapy or chemotherapy and recovery from related toxicity, no prior treatment with VCR or VP-16, and no more than two prior chemotherapy regimens (only one for treatment of metastatic disease). Treatment consisted of 0.5 mg i.v. (bolus) VCR followed by 200 mg/m2 VP-16 given over 2 h. Both drugs were given daily for 3 consecutive days every 3 weeks (total dose: VCR, 1.5 mg; VP-16, 600 mg/m2). A total of 18 patients with metastatic breast cancer were accured; 14 had adjuvant chemotherapy and 8 had chemotherapy for advanced disease. As judged by International Union Against Cancer (UICC) criteria, one complete response (CR) and three partial responses (PR) were obtained, for a CR + PR rate of 22% (95% confidence interval, 6%-48%). All responders had soft-tissue involvement only. Six patients had stable disease and 8 showed progression. The median time to treatment failure was 3.5 months, and the median survival from study entry was 8.3 months. The major toxicity was myelosuppression, with 9 patients (50%) experiencing a total WBC of < 1,000/mm3. Grade 2-3 neurologic toxicity was noted in 6 patients (33%) and grade 3 nausea and vomiting was noted in 5 (28%). The combination of VCR and VP-16 is active in advanced breast cancer but is not convincingly superior to either of these agents used alone.

Comparison of patient-controlled and nurse-controlled antiemetic therapy in patients receiving chemotherapy.

The purpose of this quasi-experimental pilot study was to compare the effect of patient-controlled (PCAE) and nurse administered (NCAE) antiemetic therapy for controlling chemotherapy-induced nausea and vomiting in patients receiving moderate emetogenic chemotherapy. Twenty subjects were randomly assigned to either the PCAE group who received IV antiemetic medication via a patient-controlled pump or the NCAE group who received antiemetic medication via nurse administered minibags. Nausea, vomiting, sedation, and drug consumption were measured. There was no difference in nausea scores between the two groups. Subjects in the PCAE group consumed significantly less medication than subjects in the NCAE group.

Orthotopic liver transplantation for graft-versus-host disease following bone marrow transplantation.

Chronic graft-vs.-host disease occurs in 30%-50% of long-term survivors of allogeneic bone marrow grafts, and may eventuate in cirrhosis. In this study, a young woman, originally diagnosed as having acute myelogenous leukemia, underwent successful bone marrow transplantation but later developed graft-vs.-host disease-induced cirrhosis and recurrent variceal hemorrhage. She underwent successful orthotopic liver transplant. Her postoperative course was uncomplicated, with no evidence of rejection or recurrence of graft-vs.-host disease. As bone marrow transplantation is more widely used and survival improves, the number of patients with graft-vs.-host disease or venoocclusive disease resulting in cirrhosis is likely to increase. Hepatic transplantation should be considered for bone marrow transplant patients who develop end-stage liver disease.

Vinblastine infusion in non-Hodgkin's lymphomas: lack of total cross-resistance with vincristine.

Historically, vinblastine given by intravenous bolus injection has not been an effective treatment for non-Hodgkin's lymphomas; vincristine has displayed greater activity. Also, vinblastine has generally been considered to be cross-resistant with vincristine in such patients. In an attempt to overcome these obstacles, a protracted infusion of vinblastine was administered (0.5-1.5 mg/m2 per day for 5 days) and repeated every 3 weeks. Partial responses were observed in 4 of 29 (14%) patients with a variety of non-Hodgkin's lymphoma lasting 2.4, 2.4, 5.5, and 9.0 months. Just prior to treatment the responding patients had received and eventually become refractory to vincristine. These data show a lack of total cross-resistance between vinblastine and vincristine which might have important therapeutic implications in this disease.

Moderate-dose vincristine infusion in refractory breast cancer.

Continuous infusion of vincristine at the maximally tolerated infusion dosage of 0.5 mg/m2/day for 5 days has been investigated in 15 patients with refractory breast cancer. Infusion courses were repeated every 3 weeks in the absence of disease progression or prohibitive toxicity. Progressive disease was observed in 14 patients. A partial response lasting 2 months occurred in a patient with pulmonary and skin metastases who had previously received vincristine by bolus injection. Toxicity consisted primarily of mild neurotoxicity of similar degree to that expected with bolus injection. Thrombocytopenia occurred, but was uncommon. The cumulative response rate at this dosage level (2/16, 13%) in our phase I-II trials indicates very limited clinical activity of vincristine infusion in advanced, refractory metastatic breast cancer.

Vincristine infusion in refractory gynecologic malignancies.

Prolonged intravenous infusion of vincristine was evaluated in 26 patients with advanced, refractory gynecologic malignancies. Most patients (88%) had progressive disease following treatment with one or more chemotherapeutic agents. Treatment consisted of a 0.5 mg intravenous bolus injection followed immediately by continuous infusion of 0.25-0.50 mg/m2 vincristine given daily for 5 days. There were no objective responses observed among 14 patients with carcinoma of the cervix, 7 patients with carcinoma of the ovary, or 5 patients with carcinoma of the endometrium. Toxicity was mild when present and consisted of paresthesias and myalgias. Vincristine infusion appears to be a well-tolerated but ineffective treatment for refractory gynecologic malignancies.

Gynecomastia in men following antineoplastic therapy.

Six men had painful gynecomastia develop during or following the administration of cytotoxic chemotherapy. Alternative causes of gynecomastia were not delineated in any patient. Sharp increases in levels of plasma follicle-stimulating hormone (FSH) and luteinizing hormone (LH) were noted in five patients. Plasma testosterone concentrations were within or above the normal range in all five patients in whom they were determined. In three patients, plasma estradiol concentrations were modestly increased. One patient was studied prospectively: painful gynecomastia developed at a time when plasma FSH and LH levels were elevated, serum testosterone was decreasing from supranormal to low-normal concentrations, and plasma estradiol was rising to high levels. Plasma prolactin levels were increased in one of four patients in whom they were measured. The mechanisms leading to gynecomastia following cytotoxic chemotherapy were not defined. Damage to germinal epithelium and Leydig cells as well as changes in the peripheral metabolism of testosterone and estrogen may be important. Gynecomastia may occur following cytotoxic chemotherapy and does not necessarily represent current or progressive cancer.

Paraprotein-induced hyperviscosity. A reversible cause of stroke.

Although the occurrence of the hyperviscosity syndrome with IgG plasma cell leukemia is unusual, it should be considered in the evaluation of patients with focal neurologic deficit with or without a known malignant paraproteinemia. If serum viscosity is elevated, then emergent plasmapheresis should be considered, as it may reverse the neurologic deficit.

The regulatory effect of estrogens on fetal growth. IV. Brain development in growth accelerated fetuses in rabbits.

Brain weights and DNA, RNA, and total protein concentrations were determined on 31-day-old fetuses whose growth had been accelerated incidental to estrogen deficiency following maternal oophorectomy. Compared to controls, there were no differences in the DNA, RNA, or total protein concentrations, although the mean brain weight was increased. The higher mean brain weight in the growth accelerated fetuses was related to the increased mean fetal weight, and did not represent an independent response to the estrogen deficiency. A comparison of the influence of fetal weight versus gestational age on the weight of the fetal brain shows that gestational age exerts an effect apart from that of fetal weight.