Onset Of Irritability Research Articles

Interferon-related Depression in Hepatitis C Patients: Predictive Value of Bio-psycho-social Factors

Introduction Interferon-related depressive disorders are well known in literature. Despite this, few study have been able to identify reliable predictors of depression Aims Our aim was to examine the predictive value of several bio-psycho-social factors for the development of persistent clinically significant depression in patients affected by HCV treated with IFN. We also aimed at describing the clinical course, treatment and impact on quality of life of depression. Methods We conducted a cohort prospective study with assessments at baseline and at 4, 8, and 24 weeks with clinical interview and self-administered psychometric tests. We evaluated depressive symptoms with the Hamilton Depression Rating Scale, manic symptoms, anxiety, suicidal ideation, temperament, alexithymia and quality of life with other reliable instruments. Results Preliminary results are available for 61 patients. Depressive symptoms increased significantly during IFN therapy to peak after 4 weeks. A third of patients still suffered clinically significant symptoms after six months. In a multivariate model, the onset of irritability (aOR= 6.5; p=0.03) and living alone (aOR= 7.4; p=0,06) predicted the persistence of depression after 6 months. The preliminary model displayed good levels of specificity and sensitivity. Conclusions Both psychological traits (irritability) and social factors (living alone) predicted the persistence of depression. These findings might prove useful to improve early detection of vulnerable patients and their mental health care in the real clinical world. Larger samples are however needed to confirm these findings.

Index of Suspicion in the Nursery

A 4-day-old term male infant develops progressive irritability with pallor and poor capillary refill. He has been hospitalized in the intensive care nursery for refractory hypoglycemia since birth. He has no risk factors for hypoglycemia, and his glucose concentrations have stabilized to normal limits with the administration of intravenous 20% glucose through an umbilical venous catheter (UVC). Imaging of the UVC initially showed placement in the liver; the UVC was withdrawn 1 to 15 cm and confirmed by chest radiograph to be in the right atrium. The infant has been otherwise well, with stable vital signs and unremarkable laboratory values except for glucose. At the onset of irritability, glucose concentrations are normal. He is afebrile, but develops rapidly progressive hypoxia and bradycardia that requires the administration of 100% oxygen. Transillumination of the chest wall does not suggest pneumothorax. A chest radiograph reveals a cardiac silhouette at the upper limit of normal, but well-aerated lung zones without infiltrates (Fig. 1). A complete blood count (CBC) and blood cultures are obtained, and prophylactic ampicillin and gentamicin are initiated. Electrocardiography reveals normal results. Four extremity blood pressures are attempted but are unable to be recorded. The infant deteriorates to asystole, is intubated with an endotracheal tube, and receives cardiopulmonary resuscitation (CPR). Figure 1. Chest radiograph showing the cardiac silhouette at the upper limit of normal, but no lung infiltrates. During resuscitation, epinephrine is administered via the endotracheal tube, and bicarbonate and fluid repletion are provided. A prostaglandin drip is started. When these interventions do not result in clinical improvement, intravenous epinephrine is administered without response. Within 10 minutes of resuscitation, beside echocardiography is obtained and reveals the diagnosis (Fig. 2). Figure 2. Echocardiographic image. A 10-day-old male infant is admitted to the hospital because of abdominal distention. He was delivered at term by repeat cesarean section …

Natural selection and feeding speed in a blood-sucking insect

When a blood-sucking insect 'bites’ a sensitized host it must, if it is to survive, depart before the host is alerted by the irritation that accompanies or precedes the 'immediate’ reaction. There is a safety period between initial salivary injection by the insect and onset of irritation in the host during which the insect’s meal must be completed; immunity from attack by the host must, therefore, depend partly on the speed at which the insect can tap the blood supply and complete its meal, and partly on an adequate delay in the onset of irritation in the host. In mosquitoes, and other insects that depend on a blood meal for egg production, only those that complete the meal within the safety period can lay a full complement of eggs; the others will either be killed or injured by the host before egg development begins, or they will be disturbed before completion of the meal and so lay fewer eggs. Thus, fast feeders and those producing a delay in the onset of irritation will tend to lay more eggs, and these two properties will be maintained by natural selection, with the onset of irritation in the host acting as the main selection force. Experiments were made comparing a population of wild mosquitoes ( Aëdes africanus ) with that of a colonized species ( A. aegypti ), which had been protected from retaliatory action by the host during the previous 3 years. They showed that while the period between salivary injection and the onset of irritation was the same in both species ( ca . 3 min), feeding was usually fast in the wild species, which had presumably been subjected to rigorous selection against slow feeding, but variable and often slow in the captive species, which had been reared for generations in the absence of this pressure. The results also indicated a slight compensatory delay in the onset of irritation following slow feeding in the wild mosquitoes; presumably a difference in antigenic properties of the saliva affects the speed at which the insect can take up blood, and provides what appears to be a remarkable alternative path way to successful feeding, and so to maximum egg output and thus to survival.