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Biomedical subjects

N Goel

Publications and source records attributed to N Goel.

At least 37 records · Page 2Linked to original sources
PubMed1998

Removal of the olfactory bulbs delays photic reentrainment of circadian activity rhythms and modifies the reproductive axis in male Octodon degus.

The diurnal rodent, Octodon degus, exhibits robust sex differences in several circadian measures, including circadian period (tau) and reentrainment rates to photic and nonphotic (social) zeitgebers. The neural substrates underlying such physiological differences remain unknown. In female degus, olfactory bulbectomies (BX) inhibit socially-facilitated reentrainment, but do not alter photic reentrainment, entrained measures, or tau in constant darkness (DD). This experiment investigated the effects of BX in male degus on (i) photic reentrainment rates of circadian rhythms following a 6-h phase advance of the light-dark (LD) cycle; (ii) photic entrainment; (iii) tau of free-running activity rhythms in DD; and (iv) body weight, paired testis weight, and the reproductive hormones, testosterone, androstenedione and follicle stimulating hormone (FSH). BX significantly delayed photic reentrainment rates. They did not, however, modify tau, the phase of activity onset or offset, amplitude or duration (alpha) of the activity rhythm, mean daily locomotor activity levels, or body weight. FSH, testosterone and androstenedione were unaffected by BX, whereas paired testis weights were significantly greater in BX degus compared with shams. Thus, the olfactory bulbs influence photic reentrainment of circadian rhythms and modestly affect the reproductive axis in male degus. Our results suggest that the olfactory bulbs may be a neural source of observed sex differences in photic reentrainment in degus, and highlight interspecies variation in the olfactory bulbs' effects on entrained and free-running circadian rhythms and on reproduction.

Animals↗
PubMed1998

Antiphospholipid antibody syndrome: current concepts.

Antiphospholipid antibody syndrome is a well-recognized cause of hypercoagulability and has multiple manifestations. Patients with an unexplained thrombotic event should be evaluated for the disorder, which can be primary or secondary to another autoimmune disease. The mechanisms of thrombosis are still being elucidated, and the optimal therapeutic regimens remain controversial.

Antibodies, Anticardiolipin↗
PubMed1998

Systemic lupus erythematosus in three ethnic groups: II. Features predictive of disease activity early in its course. LUMINA Study Group. Lupus in minority populations, nature versus nurture.

OBJECTIVE: To determine the factors associated with disease activity in patients with recent-onset (< or =5 years) systemic lupus erythematosus (SLE) who were of Hispanic, African-American, or Caucasian ethnicity. METHODS: Incident and prevalent cases of SLE, as defined by the American College of Rheumatology criteria for SLE, among the 3 ethnic groups were identified in Alabama (The University of Alabama at Birmingham) and Texas (The University of Texas-Houston Health Science Center and The University of Texas Medical Branch at Galveston). Variables from the sociodemographic, clinical, immunologic, immunogenetic, behavioral, and psychological domains were obtained using validated instruments. Disease activity was ascertained with the Systemic Lupus Activity Measure (SLAM). Stepwise domain regressions with SLAM score as the dependent variable were performed. Final ethnic-specific and overall regression models were obtained by entering variables that were retained in the domain regressions. RESULTS: SLAM scores at study entry were higher in the African Americans (mean +/- SD 12.6 +/- 6.9) and Hispanics (11.0 +/- 6.2) than in the Caucasians (8.5 +/- 3.7) (P < or = 0.001). The final overall regression model (R2 = 28%) for higher SLAM score included the following variables: African-American ethnicity, lack of private health insurance, abrupt disease onset, presence of anti-Ro antibodies, absence of HLA-DRB1*0301, higher levels of helplessness, and abnormal illness-related behaviors. CONCLUSION: Socioeconomic, immunologic, immunogenetic, behavioral, and psychological variables were all predictive of disease activity early in the course of SLE, irrespective of ethnic group. However, there remain ethnic group differences in disease activity that were not explained by these factors.

Adolescent↗
PubMed1997

Social cues modulate free-running circadian activity rhythms in the diurnal rodent, Octodon degus.

Two experiments assessed the effects of social cues and daily disturbance on the circadian locomotor activity rhythms of Octodon degus housed in constant darkness. In experiment 1, females in free-running conditions were housed alone or with entrained female partners ("donors") in cages on either side of a mesh barrier. Donors were removed daily and entrained to 1 h of light, and as a control, the cages of singly housed animals were rustled daily coincident with donor removal and replacement. None of the animals housed alone entrained to daily disturbances presented during the active phase, and seven of eight degus failed to show changes in the circadian period (tau) or phase of their rhythms. In contrast, although the presence of entrained donors did not elicit full entrainment of free-running rhythms, five of six animals demonstrated partial entrainment for 5-12 days (of 30 days), four of six altered phase of activity onset, and six of six lengthened tau of circadian rhythms. In experiment 2, females whose free-running circadian activity rhythms were at least 10 h out of phase were housed together in pairs. None of the pairs demonstrated mutual synchronization of their activity rhythms, although 8 of 12 degus modified phase of activity onset and 9 of 12 animals altered tau. We conclude social information in the absence of light, is sufficient for partial entrainment and for changes in tau and phase of free-running rhythms in this diurnal rodent.

Animals↗
PubMed1997

Rhythm chronotypes in a diurnal rodent, Octodon degus.

Interindividual variations in entrained human circadian rhythms and their relationship to differences in ease of adjustment to phase shifts have been well described. Humans classified as morning type (MT) display phase-advanced temperature minimum, onset of daily activity, and onset of sleep, whereas evening type (ET) individuals demonstrate the opposite pattern with a later phase angle of entrainment for these measures. We examined 15 variables of circadian activity and temperature for diurnal Octodon degus (n = 49; 28 male, 21 female), and noted similar chronotype variations as described for humans. Individuals with extreme MT and ET chronotypes were identified as those who differed from the entire population mean by one or more standard deviations. Compared with MTs (n = 5) and intermediate chronotypes (ITs, n = 34), ETs (n = 10) displayed a significant delay in the phase of temperature minimum, rise in temperature above the daily mean, and decline in activity and temperature below the daily mean, and had longer elevated activity and temperature durations and higher levels of mean daily activity and activity amplitude. MTs also displayed a significant phase advance in the morning temperature rise compared with ITs and ETs. This is the first description of variation in entrained circadian rhythms similar to that described for humans in both an outbred animal population and a diurnal rodent.

Activity Cycles↗
PubMed1997

Olfactory bulbectomy impedes social but not photic reentrainment of circadian rhythms in female Octodon degus.

Recent studies demonstrated that nonphotic (social) cues markedly accelerate reentrainment to large phase shifts of the light-dark (LD) cycles in female Octodon degus and that such changes are likely effected by chemosensory stimuli. This experiment investigated the effects of olfactory bulbectomies on (1) socially facilitated reentrainment rates of circadian rhythms following a 6-h phase advance of the LD cycle, (2) photic reentrainment rates of circadian rhythms following a 6-h advance of the LD cycle, (3) photic entrainment, and (4) the circadian period (tau) of activity rhythms in constant darkness (DD). olfactory bulbectomies (BX) blocked socially facilitated reentrainment rates but did not alter reentrainment rates of circadian rhythms to photic cues alone. In addition, BX lowered mean daily locomotor activity levels and decreased the amplitude of the activity rhythm in degus housed in entrained (LD 12:12) conditions but did not alter the phase of activity onset or offset, duration (alpha) of activity, or mean daily core body temperature. Bulbectomies also failed to modify tau of free-running activity rhythms. This experiment confirms that the olfactory bulbs and chemosensory cues are necessary for socially facilitated reentrainment. In contrast to their effects in nocturnal rodents, BX do not produce significant circadian photic changes in diurnal degus. This is the first experiment to determine that chemosensory stimuli modulate the circadian system in a diurnal rodent.

Animals↗
PubMed1997

Rapid diagnosis of chlamydial infection in patients with pelvic inflammatory disease and infertility by immunoperoxidase assay.

The study describes the value of specific chlamydial IgM antibody detection by indirect immunoperoxidase assay (IPA) for early confirmation of cases of primary infertility and pelvic inflammatory diseases (PID) of chlamydial aetiology. Forty-eight infertile women and forty-six women with acute PID were screened. Seven (14.2%) infertility patients and twenty-one (45.6%) PID patients had positive titers for chlamydia trachomatis. The difference in incidence of antichlamydial antibodies in the study group as compared with control was statistically significant (p < 0.05). These findings suggest that in the absence of tissue culture facilities, detection of specific chlamydial IgM antibody is a sensitive serological marker for specific diagnosis of chlamydial infection.

Antibodies, Bacterial↗
PubMed1996

Oxy free radical system in heart failure and therapeutic role of oral vitamin E.

Twenty patients of heart failure and ten matched healthy controls were included in the trial. Out of these 20 patients of heart failure, 12 patients were also studied prospectively. Plasma levels of superoxide anion and malonyldialdehyde were increased while the levels of superoxide dismutase, catalase and glutathione reductase were decreased in patients of heart failure as compared to control subjects. The alteration in oxidative stress and antioxidant system did not correlate with the age and sex of patients or the etiology of heart failure. With the increasing severity of heart failure the malonyldialdehyde and superoxide anion increased significantly and catalase, glutathione reductase and superoxide dismutase levels decreased. The group of heart failure patients with ejection fraction < 40% (n = 7) exhibited significantly higher levels of malonyldialdehyde than those with an ejection fraction > 40% (n = 13). The superoxide anion and malonyldialdehyde levels were significantly higher in patients of heart failure in the pre-treatment state as compared to those in post-treatment state. Conversely catalase, glutathione reductase and superoxide dismutase were higher in the post-treatment period as compared to their values before treatment. The addition of vitamin E in doses of 400 mg once a day orally for 4 weeks significantly reduced the malonyldialdehyde and superoxide anion levels and produced an elevation of the antioxidant enzymes. Thus, there is an apparent normalisation of the indices of oxidative stress following treatment of heart failure and a markedly improved response on vitamin E supplementation which may be more beneficial.

Administration, Oral↗
PubMed1996

Visual search for natural grains in pigeons (Columba livia): search images and selective attention.

The experiments reported here were designed to test the suggestion of many researchers that selective attention to visual features of a prey can account for search-image effects. In 3 experiments pigeons ate wheat and vetch grains presented on multicolored and gray gravel trays. In Experiment 1 search-image effects were evident when grains were cryptic but not when they were conspicuous. Experiment 2 demonstrated that search images can be activated when the grains encountered are either cryptic or conspicuous but that search images affect search performance only when the grains are cryptic. Experiment 3 demonstrated that search images are short-term in nature: A 3-min delay between successive encounters with a type of grain disrupted an activated search image. The discussion addresses how these results further develop a model in which search images are viewed as selective attention to visual features of a prey.

Animals↗
PubMed1996

Extensive extraaxial blastomycosis granuloma at the skull base--case report.

A 37-year-old female presented with a rare case of intradural, extraaxial Blastomyces dermatitidis granuloma involving a large part of the skull base. She had the principal complaint of worsening vision, but was otherwise healthy. The lesion mimicked an en-plaque meningioma on radiological examination and in gross appearance during surgery. This is a very unusual presentation for a blasto-mycosis granuloma.

Adult↗
PubMed1996

P3 event related evoked potentials in pregnancy.

Cognitive function using P3 auditory event related evoked response was examined in 18 pregnant women of age group 18-25 years (Mean 21.78 +/- 2.1). P3 was obtained from scalp electrodes at CZ, PZ referenced to ear lobules during a task in which the subjects concentrated and pressed the button on hearing high pitched rare clicks in a train of low-pitched frequent and high pitched rare clicks. Latency and amplitude of P3 was compared with age matched twelve non-pregnant women. There was a significant increase in P3 latency and amplitude in the pregnant group suggesting that changed milieu of pregnancy does affect generators of P3 component of event related potential and cognitive functions of the brain.

Adolescent↗
PubMed1995

Lack of correlation between serum soluble Fas/APO-1 levels and autoimmune disease.

OBJECTIVE: To determine whether elevated soluble Fas/APO-1 (sFas/APO-1) levels are associated with either autoimmune disease or evidence of flares in autoimmune disease. METHODS: Thirty-seven serum samples were retrospectively obtained from normal controls and patients with laboratory evidence of autoimmune disease activity. These samples were assayed for sFas/APO-1 levels by an enzyme-linked immunosorbent assay, and hospital medical records were retrospectively reviewed for clinical and laboratory characteristics of the patients. RESULTS: Soluble Fas/APO-1 levels did not correlate with clinical diagnoses or laboratory abnormalities. The mean and range of sFas/APO-1 levels were similar in systemic lupus erythematosus patients (including those with active disease), patients with other autoimmune diseases, and normal controls. CONCLUSION: These data strongly suggest that measurement of sFas/APO-1 levels is unlikely to hold clinical value or play a role in the pathogenesis of autoimmune disease.

Adolescent↗
PubMed1995

Sex differences and effects of social cues on daily rhythms following phase advances in Octodon degus.

Two experiments were designed to determine whether social cues could enhance the rate of resynchronization in body temperature and general activity rhythms in male or female Octodon degus following a 6 h phase advance. The first experiment examined average resynchronization rates for animals in each condition. The second experiment examined resynchronization rates for a smaller group of animals, each treated as its own control. Female phase-shifters resynchronized temperature and activity rhythms significantly faster when housed with an entrained (donor) female than those females housed with another phase-shifting female or housed alone. Females housed with entrained males resynchronized their temperature rhythms significantly slower than females housed with entrained females. No differences in resynchronization rate for phase-shifting males existed between test conditions. However, activity rhythms of male controls (housed alone) reentrained significantly faster than those of female controls. These experiments demonstrate a sex difference in (i) reentrainment rate by photic cues alone; (ii) donors' effect on female phase-shifters' resynchronization; and (iii) phase-shifters' resynchronization response to donor cues. In these studies, resynchronization in the presence of another animal could either have been achieved by entrainment of the pacemaker or by masking of the circadian rhythms.

Animals↗
PubMed1994

Grease gun injuries to the orbit and adnexa.

The grease gun injury is an uncommon injury to the orbit. However, high-pressure injection of grease, oil, or paint is frequently reported in injuries of the hand and usually affects the fingers or palm, which require complicated surgical and medical care. Two cases of grease gun injury to the orbit are reported: one, a catastrophic injury, and the other resulting in satisfactory recovery after surgical debridement and adjuvant medical treatment. Presentation, investigation, and therapy are discussed.

Accidents, Occupational↗
PubMed1994

Levels of erythrocyte malonyldialdehyde, vitamin E, reduced glutathione, G6PD activity & plasma urate in patients of pregnancy induced hypertension.

To assess the oxidative stress across the cell membrane in patients suffering from pregnancy induced hypertension, erythrocyte malonyldialdehyde, vitamin E, reduced glutathione, glucose-6-phosphate dehydrogenase activity and plasma urate levels were estimated in 25 non pregnant women, 40 normotensive pregnant women and 40 women with pregnancy induced hypertension (PIH). As compared to non pregnant women, there was a significant increase in the levels of erythrocyte malonyldialdehyde and plasma urate in normotensive pregnant women, which were further increased in women with PIH. Erythrocyte glutathione levels were raised in normotensive pregnant women as compared to non pregnant women. Its levels were decreased in patients of PIH as compared to normotensive pregnant women. Cellular bio-availability of vitamin E was depressed in both normotensive pregnancy as well as patients with pregnancy induced hypertension as compared to non pregnant women.

Adult↗
PubMed1988

Evaluation of the CellSoft automated semen analysis system in a routine laboratory setting.

The sperm concentration and percentage motility values generated by version 3.2 of the CellSoft (Cryo Resources Ltd., New York, NY) automated semen analyzer on 200 ejaculates were compared with those obtained by standardized traditional methods. Overall, CellSoft gave mean concentrations that were 20.9 x 10(6)/ml lower (95% range of differences = -112.6 to +154.4 x 10(6)/ml). However, the difference between methods was not systematic. Below 50 x 10(6)/ml, CellSoft more often gave higher values, and above 100 x 10(6)/ml, it usually gave lower values. In the middle range, differences were randomly distributed. For motility, the CellSoft values were usually higher than those obtained by visual counting (mean difference = -17.5%, 95% range = -56.0% to +21.0%). Multiple regression analyses revealed a strong concentration dependency such that reliable values will probably be obtained only if all samples are diluted (with homologous seminal plasma) before CellSoft analysis. This upper concentration limit is of the order of 30 to 50 x 10(6)/ml. Without such dilution, this version of CellSoft will not provide sufficiently accurate values for basic semen characteristics and cannot be accepted as a routine diagnostic method.

Humans↗