PubMed Health⌕ Search

Biomedical subjects

A Karnik

Publications and source records attributed to A Karnik.

9 recordsLinked to original sources
PubMed2001

Monitoring task loading with multivariate EEG measures during complex forms of human-computer interaction.

Electroencephalographic (EEG) recordings were made while 16 participants performed versions of a personal-computer-based flight simulation task of low, moderate, or high difficulty. As task difficulty increased, frontal midline theta EEG activity increased and alpha band activity decreased. A participant-specific function that combined multiple EEG features to create a single load index was derived from a sample of each participant's data and then applied to new test data from that participant. Index values were computed for every 4 s of task data. Across participants, mean task load index values increased systematically with increasing task difficulty and differed significantly between the different task versions. Actual or potential applications of this research include the use of multivariate EEG-based methods to monitor task loading during naturalistic computer-based work.

Adult↗
PubMed1999

Pleural fluid findings in patients with the acquired immunodeficiency syndrome: correlation with concomitant pulmonary disease.

BACKGROUND: We sought to define the spectrum of conditions associated with pleural effusion (PE) in patients with the acquired immunodeficiency syndrome (AIDS) who submitted to diagnostic thoracentesis. METHODS: The medical records of patients with human immunodeficiency virus (HIV) infection and PE studied by thoracentesis over a 5-year period, were reviewed for demographics, clinical presentation, concomitant illnesses, pleural fluid analysis, management, and outcome. RESULTS: Thoracentesis was done in 30 patients, 24 men and 6 women, with an overall mean age of 36 +/- 9 years. Mean CD4 cell count was 157 +/- 249/mm3. The cause of the PE was infectious in 21 (70%) and noninfectious in 9 (30%). Bacterial pneumonia was the most common cause of PE (57%). Streptococcus pneumoniae and Staphylococcus aureus were the major organisms recovered. Mycobacterial infections were present in 3 patients, and Nocardia sp was isolated from 1 patient. Non-Hodgkin's lymphoma (5 cases) was the leading noninfectious cause of PE, followed by Kaposi's sarcoma (3 cases) and adenocarcinoma of the lung (1 case). Twelve of the 30 patients died during hospitalization. CONCLUSION: Pleural effusion is an important problem in patients with advanced HIV infection. It is most frequently associated with bacterial pneumonia. Cytologic and microbiologic examination of the pleural fluid is helpful in determining the cause of PE in this patient population.

AIDS-Related Opportunistic Infections↗
PubMed1999

Tracheostomy management in ordinary wards.

Tracheostomy is more commonplace, particularly since the introduction of percutaneous techniques performed at the patient's bedside in the intensive care unit. Subsequent care and management within ordinary wards causes anxiety among staff. This review identifies some of the problems encountered and discusses their potential management.

Guidelines as Topic↗
PubMed1999

Role of ethamsylate in preventing periventricular-intraventricular hemorrhage in premature infants below 34 weeks of gestation.

OBJECTIVE: To determine the role of ethamsylate in prevention of PVH-IVH in premature infants <34 weeks gestational age. DESIGN: Prospective, randomized, controlled study. METHODS: Infants less than 34 weeks gestational age were included in the trial. Neonates with congenital malformations, family history of bleeding disorders and with Apgar scores <5 at 5 minutes were excluded. Subjects were randomized into two groups--Group A infants received intravenous ethamsylate (12.5 mg/kg) six hourly for four days and Group B infants served as a control group. Regular cranial ultrasounds to detect the presence of PVH-IVH were done between days 3-5, 10-14 and 28-30 of post natal age, and before hospital discharge in all infants and weekly in infants detected to have PVH-IVH on earlier scans. Various antenatal and postnatal factors known to affect the incidence of PVH-IVH were recorded. RESULTS: A total of 192 infants underwent the trial, 93 in Group A and 99 in Group B. Antenatal corticosteroids (1 or 2 doses) were administered to 32 ( 34.4%) and 36 (36.3%) women in Group A and Group B, respectively. None of the mothers received phenobarbitone, vitamin K or indomethacin antenatally and none of the infants received phenobarbitone, vitamin E or indomethacin postnatally during the study period. PVH-IVH was seen in 26 infants in Group A, of which Grade I IVH occurred in 9, Grade II in 14, Grade III in 2 and Grade IV in one infant. Twenty-nine infants had PVH-IVH in Group B of which 11 had Grade I, 15 Grade II and 3 Grade III. None of the differences were statistically significant. CONCLUSION: Postnatal administration of ethamsylate did not decrease the incidence of PVH-IVH in the study infants.

Cerebral Hemorrhage↗
PubMedDate not supplied

Nitric oxide production and apoptosis by GP120.

Nitric oxide (NO) is increased by gp120 in astrocytes and in monocyte-derived macrophages. Of the gp120 fragments (F1: amino acid 254-274, F2: amino acid 315-329, F3: amino acid 421-438), F1 has been shown to increase NO in astrocytes and gp120 also primes CD4+ T cells for apoptosis. Peripheral blood mononuclear cells (PBMCs) at 10(6)/ml (N = 10) were incubated at 24 and 72 hours in RPMI, 10% CO2 with low doses (100 nM) gp120 and high doses (400 nM) of the smaller fragments. Supernatants were collected and assayed for the relative contribution of gp120 and its fragments on NO production at both time points. Apoptosis was detected by in situ hybridization with and without 1 microgram/ml LPS as superantigen at 72 hours. The major contribution to apoptosis and NO production was from F1. At 24 hours F1 had a 1.9-fold increase from control, whereas F2 and F3 had 1.25- and 1.35-fold increases. At 72 hours both F1 and F2 had a 1.5-fold increase and F3 had a 1.33 increase. Thus, F1 contributed significantly to NO production at 24 hours. Both F1 and F2 had significant contributions to NO production at 72 hours. F1 had the most contribution to apoptosis both with and without lipopolysaccharide (LPS). These findings may contribute to further understanding the mechanism of HIV-induced apoptosis.

Apoptosis↗