ABSTRACT
The activation of presynaptic histamine 3 (H(3)) receptors inhibits the release of histamine and other neurotransmitters from central nervous system neurons. Rat brain mast cells (MCs) release histamine and 5-hydroxytryptamine (5-HT) in response to neuropeptides and neurotransmitters secreted from adjacent neurons. Dura MCs also degranulate in response to antidromic trigeminal nerve stimulation and with acute psychological stress. Such findings have implicated brain MCs in certain neuroinflammatory disorders, such as migraines. We investigated the ultrastructural appearance of control and stimulated thalamic/hypothalamic (brain) MCs before and after treatment with the H(3) receptor agonist N(alpha)-methylhistamine (N(alpha)-mH) and the H(3) receptor antagonist thioperamide (Th). Ultrastructural investigation of brain MCs stimulated with compound 48/80 revealed extensive intragranular changes that paralleled 5-HT secretion but without degranulation by exocytosis typical of connective tissue MCs. N(alpha)-mH significantly reduced these morphological changes, as well as 5-HT release from brain MCs and neurons stimulated with KCl; conversely, Th augmented both histamine and 5-HT release from brain neurons and MCs. Neither N(alpha)-mH nor Th had any effect on peritoneal MCs. Simultaneous addition of both drugs largely antagonized each other's effects on brain MC activation and 5-HT secretion. Ultrastructural observations and lack of lactic dehydrogenase release in the perfusate excluded any cytotoxic effect. The ability of H(3) agonists to inhibit brain MC activation, as well as secretion of 5-HT from both brain MCs and neurons, may be useful in the management of migraines.
Subject(s)
Brain/cytology , Brain/drug effects , Histamine Agonists/pharmacology , Histamine Antagonists/pharmacology , Mast Cells/drug effects , Methylhistamines/pharmacology , Peritoneal Cavity/cytology , Piperidines/pharmacology , Receptors, Histamine H3/physiology , Animals , Brain/metabolism , Cell Survival/drug effects , Histamine Release/drug effects , Male , Mast Cells/physiology , Mast Cells/ultrastructure , Neurons/metabolism , Rats , Rats, Sprague-Dawley , Serotonin/metabolismABSTRACT
A case of spontaneous pneumomediastinum secondary to hyperemesis gravidarum is presented. The pathophysiology, clinical presentation, differential diagnosis, and management of this unusual complication of hyperemesis gravidarum are reviewed.
Subject(s)
Hyperemesis Gravidarum/complications , Mediastinal Emphysema/etiology , Adult , Diagnosis, Differential , Esophageal Perforation/diagnosis , Female , Humans , Hyperemesis Gravidarum/drug therapy , Mediastinal Emphysema/diagnostic imaging , Mediastinal Emphysema/therapy , Pregnancy , RadiographyABSTRACT
Clinical infection with Trichomonas vaginalis (T. vaginalis) in the neonate is an unusual occurrence. We present a case of T. vaginalis in a 2-week-old girl with vaginal discharge. Our patient had complete resolution of symptoms after treatment with metronidazole. We found few references in the medical literature on the treatment of this condition. This report discusses the pathogenesis and treatment of T. vaginalis in the neonate.
