Cytochrome c mRNA levels decrease in senescent rat heart.

The concentration of mitochondria decrease in the heart as rodents age from maturity to senescence. The reason for this change is not known. One purpose of the present study was to determine if cytochrome c mRNA, representative of proteins of the inner mitochondrial membrane, decreased in the hearts of Fischer 344 rats as they aged from 12 to 24 months. Twenty-two percent less cytochrome c mRNA existed per given quantity of extracted RNA from the heart in 24-month-old rats as compared with the 12-month-old group. No change in the quantities of cardiac -actin mRNA, Ca²⁺/calmodulin protein kinase II mRNA or 18S rRNA was noted between 12- und 24-month-old hearts. Thus, the decrease in cytochrome c mRNA suggests that decreased in mRNAs for proteins of the inner mitochondrial membrane could play some role in the diminished concentration of mitochondria that exists in the senescent heart.     

Capsaicin selectively reduces airway responses to histamine, substance P and vagal stimulation.

Airway responsiveness to histamine, substance P, methacholine and bilateral electrical vagal stimulation was assessed in capsaicin-treated and control guinea pigs. In animals treated with capsaicin (50 mg/kg s.c.) 7 days before experiments, airway responsiveness to histamine, substance P and vagal stimulation was significantly reduced but responsiveness to methacholine was unchanged. The findings suggest that histamine and substance P, but not methacholine, require capsaicin-sensitive sensory afferent nerves for part of their actions.     

Human infection with Cryptosporidium spp.: results of a 24-month survey

We report the findings of a two-year survey of faecal specimens for the protozoal pathogen, Cryptosporidium. Of the 2248 patients who were tested, 55 (2.5%) patients were found to have cryptosporidial infection. Transmission of the parasite appeared mainly to occur from person to person. In immunocompetent patients it caused an acute and sometimes severe gastroenteritis. Immunoincompetent patients experienced a variable illness that ranged from asymptomatic carriage to severe diarrhoea, causing malabsorption and ultimately death. Cryptosporidium is an important cause of gastroenteritis and may be the presenting feature of the acquired immunodeficiency syndrome. Therefore, it is pertinent to screen for this pathogen in all patients with acute diarrhoea.     

The effects of diazoxide on total lung resistance in the anesthetized paralyzed guinea-pig

The initial effects of diazoxide on dynamic pulmonary compliance (C_L) and flow resistance (R_L) were measured in paralyzed, anesthetized guinea-pigs. Diazoxide (10, 20 or 40 mg/kg) caused a dose-related increase in R_L and decrease in C_L. The increase in R_L could be selectively abolished by glossopharyngealotomy or decentralization, and by pretreatment with mepyramine (0.1 mg/kg) or disodium cromoglycate (10 mg/kg). Pretreatment with indomethacin (0.1 mg/kg) or acetylsalicylic acid (1 mg/kg) selectively eliminated the decreases in compliance observed after diazoxide. It is concluded that diazoxide initially constricts both large (R_L) and small (C_L) airways. The constriction of the large airways may involve a release of histamine, whereas the constriction of the small airways may be mediated by a prostaglandin or prostaglandin-like substance.     

Comorbid psychiatric disorders in depressed outpatients: demographic and clinical features

BACKGROUND: This study evaluated the clinical and sociodemographic features associated with various degrees of concurrent comorbidity in adult outpatients with nonpsychotic major depressive disorder (MDD). METHODS: Outpatients enrolled in the STAR*D trial completed the Psychiatric Diagnostic Screening Questionnaire (PDSQ). An a priori 90% specificity threshold was set for PDSQ responses to ascertain the presence of 11 different concurrent DSM-IV Axis I disorders. RESULTS: Of 1376 outpatients, 38.2% had no concurrent comorbidities, while 25.6% suffered one, 16.1% suffered two, and 20.2% suffered three or more comorbid conditions. Altogether, 29.3% met threshold for social anxiety disorder, 20.8% for generalized anxiety disorder, 18.8% for posttraumatic stress disorder, 12.4% for bulimia, 11.9% for alcohol abuse/dependence, 13.4% for obsessive-compulsive disorder, 11.1% for panic disorder, 9.4% for agoraphobia, 7.3% for drug abuse/dependence, 3.7% for hypochondriasis, and 2.2% for somatoform disorder. Those with more concurrent Axis I conditions had earlier ages at first onset of MDD, longer histories of MDD, greater depressive symptom severity, more general medical comorbidity (even though they were younger than those with fewer comorbid conditions), poorer physical and mental function, health perceptions, and life satisfaction; and were more likely to be seen in primary care settings. LIMITATIONS: Participants had to meet entry criteria for STAR*D. Ascertainment of comorbid conditions was not based on a structured interview. CONCLUSIONS: Concurrent Axis I conditions (most often anxiety disorders) are very common with MDD. Greater numbers of concurrent comorbid conditions were associated with increased severity, morbidity, and chronicity of their MDD.