Evaluation of arylmethylaminopropanediols by a novel in vitro pharmacodynamic assay: correlation with antitumor activity in vivo

The pharmacodynamics of a new series of antitumor DNA intercalators, known as arylmethylaminopropanediols (AMAPs), has been evaluated in vitro against adherent (MCF-7 human breast cancer) and nonadherent (P388 murine leukemia) cell lines. Previous work had shown that the in vitro antitumor activity of the model AMAP crisnatol was a function of exposure (Cn x T), rather than concentration alone. A unique exposure parameter, the minimum C x T, was proposed as an end point for antitumor activity in cell culture. Comparison of crisnatol to several established agents by the minimum C x T versus the standard concentration producing 10% survival indicated that these end points were not equivalent. The current work examined the validity of the pharmacodynamic approach using AMAP isomers from three different ring systems that were known to exhibit a spectrum of activity against the P388 tumor in vivo. The results indicated that antiproliferative, but not cytotoxic, activity of AMAPs in the pharmacodynamic assay correlated with their differential activity in vivo, expressed as percentage of increase in life span. In contrast, the concentration producing 10% survival either at 1 h or after continuous exposure did not show a similar correlation. The pharmacodynamic assay also revealed that certain AMAPs, while equipotent by concentration alone, required significantly less time and therefore less overall exposure for efficacy. Finally, the activity of AMAP isomers in P388 cells differed from that in MCF-7 cells, which may indicate AMAP selectivity for certain tumor types. Since AMAP action was a function of exposure, drug effects on cellular targets could likewise depend on exposure rather than concentration. These findings emphasize the importance of relating drug mechanisms to the pharmacodynamics of anticancer agents.     

EEG abnormalities during treatment with typical and atypical antipsychotics.

OBJECTIVE: Clozapine produces EEG abnormalities and dose-dependent risk of epileptic seizures. Much less is known about EEG effects of newer antipsychotics. The present study therefore examined the risk of EEG abnormalities associated with various antipsychotic drugs. METHOD: EEG recordings from 323 hospitalized psychiatric patients (293 treated with antipsychotics, 30 who did not receive any antipsychotic treatment) were graded blind to diagnosis and treatment for type and severity of EEG abnormalities. Drug type, dose, and clinical factors were evaluated for association with EEG abnormalities by multivariate logistic regression. RESULTS: EEG abnormalities occurred in 56 subjects (19.1%) treated and four (13.3%) not treated with antipsychotics. EEG abnormality risk among antipsychotic agents varied greatly (clozapine=47.1%, olanzapine=38.5%, risperidone=28.0%, typical neuroleptics=14.5%, quetiapine=0.0%). Significant risk factors in order of influence were hypertension, use of an atypical antipsychotic, bipolar diagnosis, and older age; benzodiazepine cotreatment lowered risk. Unassociated with risk were sex, treatment response, length of hospital stay, drug potency, daily dose (in mg or mg/kg), drug exposure time, or cotreatments. CONCLUSIONS: EEG abnormality risk varied widely among specific antipsychotics. Risk was particularly high with clozapine and olanzapine, moderate with risperidone and typical neuroleptics, and low with quetiapine. Comorbid hypertension, bipolarity, and older age-but not dose or clinical response-were associated with risk.     

Radioiodine ablation of thyroid remnants after preparation with recombinant human thyrotropin.

Radioiodine ablation (RA) of normal thyroid remnants after thyroidectomy for differentiated thyroid carcinoma improves the sensitivity of subsequent radioiodine scans and serum thyroglobulin measurements for detection of residual thyroid carcinoma. Local cancer recurrences are also lower after RA. One standard preparation for RA involves rendering the patient hypothyroid in order to stimulate endogenous thyrotropin (TSH) secretion and sodium iodide symporter (NIS) activity. An alternative approach is to prescribe thyroxine after thyroidectomy and to stimulate NIS with exogenous recombinant human thyrotropin (rhTSH). This latter approach was used in 10 patients at our medical center. Complete resolution of all visible 131I thyroid bed uptake was achieved in all when follow-up scans were performed 5 to 13 months later. This approach has the potential to successfully ablate thyroid remnants without the need to induce hypothyroidism.     

Ulnar nerve injuries of the hand producing intrinsic muscle denervation on magnetic resonance imaging

Muscle and nerve injuries in the hand may be difficult to detect and diagnose clinically. Two cases are reported in which magnetic resonance imaging showed ulnar nerve injury and intrinsic hand muscle denervation. The clinical, anatomical and radiological features of injury to the deep motor branch of the ulnar nerve and associated muscle denervation are discussed and illustrated.     

High-dose lymphoblastoid interferon in advanced renal cell carcinoma: an Eastern Cooperative Oncology Group Study

This report describes a phase II Eastern Cooperative Oncology Group (ECOG) study of high-dose lymphoblastoid interferon (IFN alpha-n1) in 39 patients with measurable, advanced renal cell carcinoma. The original treatment plan was 30 X 10(6) units/m2 (30 mU) of IFN alpha-n1 im daily X 10 days; treatments were repeated every 21 days. This dose and schedule proved intolerable, with none of seven patients able to complete greater than 10 days of therapy because of fever, lassitude, hepatic dysfunction, and myelosuppression. Patients were subsequently treated with the following regimen: 3 mU/m2 on Day 1; 5 mU/m2 on Day 2; 10 mU/m2 on Day 3; and 20 mU/m2 on Days 4-10. Thirty-three new patients received this regimen and two patients received this schedule after having received 30 mU/m2. Using this second regimen, 30% of the patients were able to complete two cycles of treatment without dose reduction or interruption. Five patients (13%) had partial response (ECOG criteria) of measurable tumor. Median time to response was 140 days. Responses were documented in lung metastases in four patients and in a pelvic soft tissue mass in the fifth. Response rates and survival times are similar to those seen in prior ECOG phase II trials in advanced renal cell carcinoma. Eight of 39 patients are still alive greater than 2 years after beginning therapy. Only two of these patients had had an objective response, however. Such prolonged survival is more frequent than has been seen in previous ECOG studies. The relative contribution of patient selection and interferon therapy to this survival is uncertain.     

Pulmonary histiocytosis X: comparison of radiographic and CT findings

The authors retrospectively evaluated radiographs, computed tomographic (CT) scans, and results of pulmonary function tests (when available) for 17 patients with biopsy-proved pulmonary histiocytosis X. In 11 patients, high-resolution CT was used. In 12 patients, CT demonstrated cystic air spaces, usually less than 10 mm in diameter. In three of these 12, cysts were the only abnormality, but in six others, nodules (usually less than 5 mm in diameter) were also present. Two patients had only nodules and one, only emphysema. CT showed that many lesions that appeared reticular on plain radiographs were actually cysts. CT showed no central or peripheral concentration of lesions, but it did reveal that many small nodules were distributed in the centers of secondary lobules around small airways. CT findings correlated better with the diffusing capacity (rho = -0.71) than did the plain radiographic findings (rho = -0.57). Thus, CT was better than radiography at showing the morphology and distribution of lung abnormalities.     

Distinguishing malignant mesothelioma from pulmonary adenocarcinoma: an immuno-histochemical approach using a panel of monoclonal antibodies

A panel of six monoclonal antibodies (MAbs) was employed to evaluate antigen expression in pulmonary adenocarcinomas and mesotheliomas. Monoclonal anti-human milk fat globulin (HMFG-2), anti-carcinoembryonic antigen (NP-2), anti-epithelial membrane antigen (EMA), anti-cytokeratin (PKK-1), anti-tumor-associated antigen 72 (B72.3), and anti-human myelomonocytic antigen (Leu M-1) antibodies were used to localize their respective antigens in formalin-fixed, paraffin-embedded tumors by using the avidin-biotin-complex immunoperoxidase technique. In all, 28 mesotheliomas obtained from Ohio State University Anatomic Pathology files and from a Southwest Oncology Group (SWOG) protocol were compared to 22 pulmonary adenocarcinomas by using this MAb panel. None of the mesotheliomas demonstrated positive staining with MAbs NP-2 (anti-CEA) or Leu M-1. However, 95% (21/22) of adenocarcinomas stained with one of these two antibodies. Although neither of these two MAbs stained all adenocarcinomas, each antibody demonstrated positive immunostaining in more than 90% of the adenocarcinomas studied. Therefore, MABs NP-2 and Leu M-1 are, individually, quite useful for distinguishing mesothelioma from adenocarcinoma. However, in our study, no single MAb could be used to distinguish these two tumor types in every case. MAb B72.3 stained 91% (20/21) adenocarcinomas but also stained 7% (2/28) of mesotheliomas. MAb HMFG-2 reacted positively with 95% of adenocarcinomas, but also stained 39% of the mesotheliomas, usually in a membranous pattern. MAbs EMA and PKK-1 were not found useful in distinguishing mesothelioma from adenocarcinoma. We conclude that MAbs Leu M-1 and NP-2 were both useful in distinguishing mesothelioma from pulmonary adenocarcinoma in that positive staining was demonstrated in adenocarcinomas and not mesotheliomas.