Effects of Erythroid Hyperplasia on Patterns of Glycin-2-C14 Uptake in Heme and Globin of Human Peripheral Blood in Vivo

The rate of appearance of C¹⁴ in the heme and globin of peripheral bloodfollowing intravenous administration of glycine-2-C14 has been measured innormals and in patients with androgen-induced erythrocytosis, polycythemiavera (iron deficiency) and virilizing Cushing’s disease with polycythemia. Inall these cases of accelerated erythropoiesis a common alteration of the globinspecific activity curve was observed. Heme specific activity curves were notaffected.

The changes in the globin specific activity curves are best explained byconsideration of the marrow erythroid cellularity during erythrocytosis.

Submitted on August 6, 1965 Accepted on January 31, 1966     

1,25-Dihydroxyvitamin D3 inhibits the passive transfer of cellular immunity by a myelin basic protein-specific T cell clone.

1,25-Dihydroxyvitamin D3 [1,25-(OH)2D3] and related analogs have been shown to exert immunoinhibitory effects on activated lymphocytes in vitro. However, the effects of the hormone on the mammalian immune response in vivo have not been well studied. To examine the possible immunoactions of 1,25-(OH)2D3 in vivo, we employed a murine model of experimental autoimmune encephalomyelitis (EAE). In this model, T helper lymphocyte clones developed from lines of lymphocytes reactive to myelin basic protein (MBP) confer MBP immunoreactivity and demyelinating central nervous system disease on syngeneic, naive recipients of the T cell clone. Similar to peripheral blood mononuclear cells incubated with mitogen, the T cell clone evaluated in this study expressed a high-affinity specific receptor for 1,25-(OH)2D3 (VDR; K(in) = 0.03 nM) upon exposure to MBP. The MBP-stimulated clone elicited a ninefold enhancement of the local delayed hypersensitivity (DTH) response when as few as 0.5 x 10(5) cells of the T cell clone were injected into the foot pad of recipient mice. The DTH response in the recipient was completely blocked when the clone was preincubated with greater than or equal to 10(-8) M 1,25-(OH)2D3 before transfer; the half-maximal inhibitory concentration of hormone (EC50) was 5 x 10(-9) M. These data indicate that exposure of antigen-reactive T helper lymphocytes to a VDR saturating concentration of 1,25-(OH)2D3 can dramatically lessen the expression of immunoreactivity in vivo.     

Femoral neck stress fracture a potentially disabling condition: a case report

Femoral neck stress fracture represents a focal weakening of the bone often associated with a recent increase in activity level. Since plain film radiographs are initially normal, the clinical diagnosis is based solely on the history and physical examination. The consequence of a delayed diagnosis could result in a complete fracture or avascular necrosis of the femoral head. This paper includes a case report illustrating the important aspects of recognizing patients presenting with an underlying femoral neck stress fracture. The need for radionuclide bone scanning for the early diagnosis of this potentially disabling condition is stressed.     

Spontaneous pneumothorax in primary cavitating lung carcinoma

Primary cavitating lung carcinomas have not previously been described with spontaneous pneumothorax as the presenting manifestation. Two patients whose pneumothoraces resulted in the initial diagnosis of a primary cavitary lung carcinoma are described. Pathologic evidence of vascular invasion suggests tumor necrosis with secondary rupture into the pleural space as a likely mechanism for pneumothorax.     

Social perception of speech in individuals with oropharyngeal reconstruction

Oral cancer affects approximately 5% of the Canadian population every year. One option for treatment of oropharyngeal cancer includes resection of the diseased tissue with primary reconstruction of the defect using a microvascular free flap, followed by post-operative adjuvant radiation therapy. The aim of reconstructive surgery is to maintain functional speech and swallowing. While the literature provides support for the maintenance of speech intelligibility following reconstructive procedures, certain aspects of resonance may be altered when the palatal structures are involved. Little is known about the effect of such alterations on the perception of speakers who have been treated with microvascular free flap reconstruction. Social perception is a process in which we infer attributes of others, with the speech signal playing an integral part in attribution. The purpose of this study was to explore the social perceptions formed about speakers both before and after surgery for oropharyngeal cancer. The results of this study revealed that positive perceptions of speakers significantly diminished as a result of surgery and negative perceptions increased. Certain variables, such as degree of resection of the soft palate and base of tongue, and sex of the speaker, had influence on the results. This research suggests that intelligibility measurements of speech, although useful, do not provide a complete indication of the social impact of reconstructive surgery on patients with oropharyngeal resections.