Scintigraphy and distribution of labeled antibodies in rats with tumors

Radioiodinated antitumor (Ab-gamma globulins), non-tumor-specific Ab, and R¹³¹ISA were used for imaging radiation-induced intestinal tumors in rats. Each agent detected tumors larger than 2 g, but labeled Ab were most efficient in detecting smaller tumors. Tissue distribution studies showed that while purified Ab localized specifically in tumors, unpurified Ab concentrated in the tumor by a mechanism not considered immunological. Localization was variable and the concentration of antitumor Ab reached useful levels only in a small number of cases. The use of high specific activity purified Ab unexpectedly decreased the concentrations of label observed in the tumors when compared with the use of the same activity of low specific activity purified Ab. These results indicated the presence of circulating tumor antigens which were capable of binding the injected Ab. Subsequently, these findings have been substantiated. Thus the animal-to-animal variability could be explained on the basis of differing degrees of interaction of injected Ab with circulating tumor antigens. The usefulness of labeled purified or monospecific antitumor antibodies for tumor imaging and therapy would thus be influenced by the extent of such interactions.This work was presented in part at the Twentieth Annual Meeting of the Radiation Research Society, Portland, Oregon, May, 1972.     

Hemin enhances the in vitro growth of primitive erythroid progenitor cells

Since exogenous hemin has been shown to exert a variety of stimulatory effects on erythroid cells, including the augmentation of hemoglobin synthesis, we determined its effect on early stages of erythroid development by employing clonal cells assays. The addition of hemin at a concentration of 2 X 10(-4) M to cultures of normal murine marrow substantially increased the observed number of primitive BFU-E, which was in contrast to its lack of an effect on more mature erythroid colony-forming cells. This cell-specific enhancement of primitive BFU-E resulted in marrow frequencies equivalent to or exceeding those reported in the presence of "burst-promoting activity." In the presence of hemin, the number of BFU-E was also observed to be linearly related to the number of cells plated at very low plating densities, and the cell titration curve was observed to extrapolate to the origin. The evidence suggests that hemin may be a primary growth regulator of early developmental stages of erythroid progenitor cells.     

Falx and interhemispheric fissure on axial CT: II. Recognition and differentiation of interhemispheric subarachnoid and subdural hemorrhage

Interhemispheric hyperdensity or unenhanced computed tomography was originally considered a sign of subarachnoid hemorrhage, the "falx sign." It has since been identified as a normal feature and has also been seen with interhemispheric subdural hemorrhage. To determine the differential features of interhemispheric hemorrhage, 50 patients with subarachnoid hemorrhage and 32 patients with interhemispheric subdural hematomas were reviewed. Subarachnoid hemorrhage produced anterior interhemispheric hyperdensity only, with a zigzag contour and extension from the calvarium to the rostrum of the corpus callosum. Interhemispheric subdural hematomas produce unilateral crescentic hyperdensities that are largest in the posterior superior part of the fissure, behind and above the splenium of the corpus callosum. Interhemispheric hyperdensity in children is more complex. Because the anterior part of the fissure is narrow in younger patients, subarachnoid hemorrhage may go undetected. Likewise, interhemispheric subdural hematomas in children are smaller and more difficult to recognize. They produce asymmetric thickening of the falx shadow with extension over the tentorium. They are, however, of great significance since they are generally seen in abused patients and carry a poor prognosis.     

Isolation and characterization of a hormone-producing cell line from human small cell anaplastic carcinoma of the lung.

A continuous cell culture line was established from a bone marrow metastasis of small cell anaplastic carcinoma of the lung. The cultures were characterized by light and electron microscopy, and an unusual concentric arrangement of cells was observed, both in sectioned material from the patient's tumor and from the cell cultures. The cells had two types of specialized cell junctions and contained secretory-like granules of the type described in neuroendocrine cells. Lactic dehydrogenase isozyme patterns were the same as those observed in normal human serum, and the karyotype revealed the presence of several marker chromosomes. Vasopressin was present in the cells and secreted into the culture medium in the absence of neurophysin, as shown by the immunoperoxidase technique and radioimmunoassay. Oxytocin was also absent from cells.     

Frequency of anxiety disorders in psychiatric outpatients with major depressive disorder

OBJECTIVE: The authors determined the frequency of anxiety disorders in a large group of depressed outpatients seeking treatment. METHOD: The Structured Clinical Interview for DSM-IV was administered to 373 depressed outpatients. RESULTS: More than one-half of the patients met the full criteria for a current anxiety disorder, and more than one-half of the patients with an anxiety disorder had more than one. When partial remissions and anxiety disorder diagnoses classified as "not otherwise specified" were included, two-thirds of the patients had a current anxiety disorder and three-quarters had a lifetime history of an anxiety disorder. CONCLUSIONS: The majority of patients with a principal diagnosis of unipolar major depressive disorder have a comorbid anxiety disorder. Because antidepressant medications have differential efficacies for anxiety disorders, knowledge of the presence of a comorbid anxiety disorder in a depressed patient may have treatment implications.     

Short-term spontaneous improvement rates in depressed outpatients

The objectives of the present report were: a) to determine the spontaneous remission rate in depressed outpatients who do not receive antidepressant medication; b) to develop a novel method for obtaining a control group that can be used to gauge the effectiveness of antidepressant medication in clinical practice; and c) to compare response rates from the present sample with outcomes of depressed patients in our practice who were treated with antidepressant medications. By using a naturalistic design, prospective assessments were made on all depressed outpatients. Twenty-five patients who met full criteria for a major depressive episode ended up not taking antidepressant medication for a variety of reasons. "Response" rates to a no-treatment trial were determined with standard outcome criteria using the Clinical Global Impression-Improvement scale. Eight patients (32.0%) had a positive response, 5 patients (20.0%) had a partial response, and 12 patients (48.0%) were nonresponders to a no-treatment trial. These response rates were higher than expected, but significantly lower than what we had found in a cohort of depressed patients who underwent an antidepressant trial (p = .02). Likewise, treatment-resistant patients fared better on pharmacotherapy, though this difference was not statistically significant. These results suggest that the occurrence of spontaneous remissions may be common in clinical practice, and therefore the specific short-term benefits of antidepressant medication in clinical practice may frequently be overestimated. Despite the high rate of spontaneous remission in our sample, the present study allowed us to confirm the effectiveness of antidepressant medication in clinical practice using a novel method for obtaining a control comparison group.