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Bhutani VK, Sivieri EM, Abbasi S, Shaffer TH. Evaluation of neonatal pulmonary mechanics and energetics: a two factor least mean square analysis. Pediatr Pulmonol 1988; 4:150-8. [PMID: 3374983 DOI: 10.1002/ppul.1950040306] [Citation(s) in RCA: 160] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Pulmonary mechanics, using a two factor least mean square analysis technique, were determined in 22 preterm neonates with respiratory failure. The respiratory system is modelled as a linear mechanical system. Concurrent signals of airflow and transpulmonary pressure were utilized to calculate values of dynamic lung compliance and pulmonary resistances; these determinations were made over the entire tidal volume range. In addition, values of resistive work of breathing, pulmonary time constants, scalar records of sequential breaths, pressure-volume and flow-volume relationships were available for data review and interpretation. The mean +/- SEM value of tidal volume was 7.4 +/- 0.6 ml/kg; dynamic lung compliance was 0.44 +/- 0.04 ml/cmH2O/kg; and the pulmonary resistance of the whole breath was 106 +/- 9.1 cmH2O/liter/s. The resistive work of breathing (hysteresis) was 41.8 +/- 5.9 gm.cm/kg. In correlating the measured values of pressure and flow to those predicted by the model, the mean value of the correlation coefficient for the least mean square analysis for all 22 studies was 0.995 +/- 0.001; the standard error of estimate of the predicted pressure was less than 4.4% of the range of pressures measured. Thereby, the model was considered to be appropriate for the neonatal respiratory system. In addition to the traditional procedures of evaluating the respiratory status of a sick neonate, bedside analysis of pulmonary mechanics provide graphical information, and quantitative data which should be useful in day-to-day pulmonary management.
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Abbasi S, Shenep JL, Hughes WT, Flynn PM. Aspergillosis in children with cancer: A 34-year experience. Clin Infect Dis 1999; 29:1210-9. [PMID: 10524965 DOI: 10.1086/313445] [Citation(s) in RCA: 142] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
A retrospective review of medical records, microbiology and pathology laboratory records, and nosocomial infection surveillance data was undertaken to describe the experience with culture-documented aspergillus infection in pediatric cancer patients at our facility. Sixty-six patients were identified from a 34-year period. The most common underlying diagnosis was leukemia. Risk factors included neutropenia, immunosuppression, and prior antibiotic therapy. On the basis of clinical presentation, 23 patients were believed to have disseminated disease and 43 to have localized disease. The lung was the most frequently affected organ. Despite aggressive medical and surgical management, overall mortality was 85% within the first year after diagnosis. Patients who presented with disease in sites other than the lungs fared better than patients with initial pulmonary involvement (P=.0014). Aspergillosis continues to be associated with poor outcome. Development of improved medical and adjuvant therapies, including surgery, is warranted.
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Cole CH, Colton T, Shah BL, Abbasi S, MacKinnon BL, Demissie S, Frantz ID. Early inhaled glucocorticoid therapy to prevent bronchopulmonary dysplasia. N Engl J Med 1999; 340:1005-10. [PMID: 10099142 DOI: 10.1056/nejm199904013401304] [Citation(s) in RCA: 124] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
BACKGROUND The safety and efficacy of inhaled glucocorticoid therapy for asthma stimulated its use in infants to prevent bronchopulmonary dysplasia. We tested the hypothesis that early therapy with inhaled glucocorticoids would decrease the frequency of bronchopulmonary dysplasia in premature infants. METHODS We conducted a randomized, multicenter trial of inhaled beclomethasone or placebo in 253 infants, 3 to 14 days old, born before 33 weeks of gestation and weighing 1250 g or less at birth, who required ventilation therapy. Beclomethasone was delivered in a decreasing dosage, from 40 to 5 microg per kilogram of body weight per day, for four weeks. The primary outcome measure was bronchopulmonary dysplasia at 28 days of age. Secondary outcomes included bronchopulmonary dysplasia at 36 weeks of postmenstrual age, the need for systemic glucocorticoid therapy, the need for bronchodilator therapy, the duration of respiratory support, and death. RESULTS One hundred twenty-three infants received beclomethasone, and 130 received placebo. The frequency of bronchopulmonary dysplasia was similar in the two groups: 43 percent in the beclomethasone group and 45 percent in the placebo group at 28 days of age, and 18 percent in the beclomethasone group and 20 percent in the placebo group at 36 weeks of postmenstrual age. At 28 days of age, fewer infants in the beclomethasone group than in the placebo group were receiving systemic glucocorticoid therapy (relative risk, 0.6; 95 percent confidence interval, 0.4 to 1.0) and mechanical ventilation (relative risk, 0.8; 95 percent confidence interval, 0.6 to 1.0). CONCLUSIONS Early beclomethasone therapy did not prevent bronchopulmonary dysplasia but was associated with lower rates of use of systemic glucocorticoid therapy and mechanical ventilation.
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Abbasi S, Hirsch D, Davis J, Tolosa J, Stouffer N, Debbs R, Gerdes JS. Effect of single versus multiple courses of antenatal corticosteroids on maternal and neonatal outcome. Am J Obstet Gynecol 2000; 182:1243-9. [PMID: 10819866 DOI: 10.1067/mob.2000.104789] [Citation(s) in RCA: 119] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
OBJECTIVE Treatment of pregnant mothers with a single course of antenatal corticosteroids significantly reduces neonatal mortality and morbidity. Multiple weekly courses are often given. However, the safety and efficacy of repeated courses of antenatal corticosteroids have not been adequately studied. STUDY DESIGN A retrospective study was performed for 609 mothers and their 713 infants who were treated with 1 to 12 courses of antenatal corticosteroids. Data for 369 singleton preterm infants born at < or =34 weeks' gestation, 210 multiple gestations, and 134 infants delivered at > or =35 weeks' gestation were analyzed separately. RESULTS The incidence of respiratory distress syndrome was 45% for single-course and 35% for multiple-course groups (P =.005; odds ratio, 0.44; 95% confidence interval, 0.25-0.79). The multiple-course group also had significantly less patent ductus arteriosus (20% vs 13%; P =.016). Incidence of death before discharge and other neonatal morbidities were similar. The multiple-course group had a reduction of 0.46 +/- 0.19 cm in head circumference at birth (P =.013) when adjusted for gestational age and preeclampsia. The 2 groups had similar birth weights. Infants born at > or =35 weeks' gestation, multiple-gestation infants, and infants who were born >7 days after the last corticosteroid dose had similar outcomes, regardless of the number of courses they received. Mothers treated with multiple courses compared with a single course had a significantly higher incidence of postpartum endometritis (P =.013), even though they had a lower incidence of prolonged rupture of membranes (24% vs 33%, P =.06) and similar cesarean delivery rates. CONCLUSION Exposure to multiple courses of antenatal corticosteroids compared with a single course resulted in a significant reduction in the incidence of respiratory distress syndrome in singleton preterm infants delivered within a week of the last corticosteroid dose. This was associated with a reduction in birth head circumference and an increased incidence of maternal endometritis. Whether the potential benefits of repeated therapy clearly outweigh the risks will ultimately be determined in randomized prospective controlled trials.
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Abstract
OBJECTIVE To study the effects of dopamine on renal, mesenteric, and cerebral blood flow in sick preterm neonates. STUDY DESIGN The pulsatility index was used to assess the dopamine-induced changes in renal, mesenteric, and cerebral blood flow by means of color Doppler ultrasonography in 23 nonhypotensive preterm neonates (birth weight: 981 +/- 314 g; postnatal age: <2 days). Dopamine was given at a dose of 6.1 +/- 3.0 microgram/kg per minute to combat oliguria, impaired peripheral perfusion, or both. Blood flow velocity measurements were made before and during dopamine administration, with each patient serving as his or her own control subject. RESULTS Dopamine significantly increased blood pressure and urine output. Dopamine decreased the pulsatility index in the renal artery (2.98 +/- 1.18 vs 1.68 +/- 0.45; P <.05) while the pulsatility index in the superior mesenteric and medial cerebral artery was not affected. Thus renal blood flow increased while mesenteric and cerebral blood flow remained unchanged during dopamine treatment. The increase in renal blood flow was independent of the blood pressure changes. CONCLUSIONS These findings suggest a functionally mature renal, but not mesenteric, vasodilatory dopaminergic response in the preterm neonate. The observations also indicate the lack of an effect of low- to medium-dose dopamine on cerebral hemodynamics in the nonhypotensive preterm neonate.
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Razeghi P, Young ME, Abbasi S, Taegtmeyer H. Hypoxia in vivo decreases peroxisome proliferator-activated receptor alpha-regulated gene expression in rat heart. Biochem Biophys Res Commun 2001; 287:5-10. [PMID: 11549245 DOI: 10.1006/bbrc.2001.5541] [Citation(s) in RCA: 89] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
We tested the hypothesis that hypoxia decreases PPARalpha-regulated gene expression in heart muscle in vivo. In two rat models of systemic hypoxia (cobalt chloride treatment and iso-volemic hemodilution), transcript levels of PPARalpha and PPARalpha-regulated genes (pyruvate dehydrogenase kinase 4 (PDK4), muscle carnitine palmitoyltransferase-I (mCPT-I), and malonyl-CoA decarboxylase (MCD)) were measured using real-time quantitative RT-PCR. Data were normalized to the housekeeping gene beta-actin. Atrial natriuretic factor (ANF) and pyruvate dehydrogenase kinase 2 (PDK2), which are not regulated by PPARalpha, served as controls. CoCl(2) treatment decreased PPARalpha, PDK4, mCPT-I, and MCD mRNA levels. Iso-volemic anemia also caused a significant decrease in PPARalpha, PDK4, and MCD mRNA levels. Transcript levels of mCPT-I showed a slight, but not significant decrease (P = 0.08). Gene expression of beta-actin, ANF, and PDK2 did not change with either CoCl(2) treatment nor with anemia. Myocardial PPARalpha-regulated gene expression is decreased in two models of hypoxia in vivo. These results suggest a transcriptional mechanism for decreased fatty oxidation and increased reliance of the heart for glucose during hypoxia.
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Mastrangeli M, Abbasi S, Varel C, Van Hoof C, Celis JP, Böhringer KF. Self-assembly from milli- to nanoscales: methods and applications. JOURNAL OF MICROMECHANICS AND MICROENGINEERING : STRUCTURES, DEVICES, AND SYSTEMS 2009; 19:83001. [PMID: 20209016 PMCID: PMC2832205 DOI: 10.1088/0960-1317/19/8/083001] [Citation(s) in RCA: 76] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
The design and fabrication techniques for microelectromechanical systems (MEMS) and nanodevices are progressing rapidly. However, due to material and process flow incompatibilities in the fabrication of sensors, actuators and electronic circuitry, a final packaging step is often necessary to integrate all components of a heterogeneous microsystem on a common substrate. Robotic pick-and-place, although accurate and reliable at larger scales, is a serial process that downscales unfavorably due to stiction problems, fragility and sheer number of components. Self-assembly, on the other hand, is parallel and can be used for device sizes ranging from millimeters to nanometers. In this review, the state-of-the-art in methods and applications for self-assembly is reviewed. Methods for assembling three-dimensional (3D) MEMS structures out of two-dimensional (2D) ones are described. The use of capillary forces for folding 2D plates into 3D structures, as well as assembling parts onto a common substrate or aggregating parts to each other into 2D or 3D structures, is discussed. Shape matching and guided assembly by magnetic forces and electric fields are also reviewed. Finally, colloidal self-assembly and DNA-based self-assembly, mainly used at the nanoscale, are surveyed, and aspects of theoretical modeling of stochastic assembly processes are discussed.
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research-article |
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Stefano JL, Abbasi S, Pearlman SA, Spear ML, Esterly KL, Bhutani VK. Closure of the ductus arteriosus with indomethacin in ventilated neonates with respiratory distress syndrome. Effects of pulmonary compliance and ventilation. THE AMERICAN REVIEW OF RESPIRATORY DISEASE 1991; 143:236-9. [PMID: 1990934 DOI: 10.1164/ajrccm/143.2.236] [Citation(s) in RCA: 75] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
The reported effects of indomethacin on pulmonary compliance are variable depending upon the patient population and on the degree to which indomethacin resulted in successful ductal closure. Eleven fluid-restricted, furosemide-treated premature infants being mechanically ventilated for respiratory distress syndrome (RDS) who also had a significant patent ductus arteriosus (PDA) had pulmonary function testing performed before and after successful closure of the PDA. The diagnosis of a significant PDA was made by clinical and echocardiographic criteria. Indomethacin was administered at a dosage of 0.2 mg/kg/dose every 12 to 18 h for 1 to 3 doses. To control for the 48-h time interval to achieve ductal closure, nine premature infants being ventilated for RDS but who did not have a significant PDA also had pulmonary function evaluations performed before and after the 48 h. Also, to control for the independent effect of fluid restriction and diuretic therapy on pulmonary compliance, eight such premature infants with a PDA had pulmonary function evaluations performed at a 48-h interval. Successful closure of the ductus with indomethacin was associated with an improvement in compliance and ventilation parameters in all infants in the indomethacin-treated infants. In the indomethacin-treated group, the mean percent improvements were noted in the following parameters: CLdyn, 59.2%; CLI, 78.3%; CLE, 63.3%; VT, 63.3%; VE, 54.6%. There were no significant changes in the pulmonary functions in the 48-h RDS or the 48-h PDA fluid-restricted, furosemide-treated control groups. In conclusion, successful closure of the ductus with indomethacin causes a significant improvement in compliance and ventilation parameters in infants being mechanically ventilated for RDS.
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Johnson L, Quinn GE, Abbasi S, Otis C, Goldstein D, Sacks L, Porat R, Fong E, Delivoria-Papadopoulos M, Peckham G. Effect of sustained pharmacologic vitamin E levels on incidence and severity of retinopathy of prematurity: a controlled clinical trial. J Pediatr 1989; 114:827-38. [PMID: 2654350 DOI: 10.1016/s0022-3476(89)80149-0] [Citation(s) in RCA: 73] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
The incidence and severity of retinopathy of prematurity (ROP) as affected by vitamin E prophylaxis at pharmacologic serum levels (5 mg/dl) were evaluated in a double-masked clinical trial of infants with a birth weight less than or equal to 2000 gm or a gestational age less than or equal to 36 weeks. The infants were enrolled by age 5 days and randomly assigned to receive parenterally administered, and later orally administered, free alpha-tocopherol (vitamin E) or its placebo. Study medication was continued until retinal vascularization was complete or active ROP had subsided, except in infants with a diagnosis of severe disease, in whom vitamin E was substituted for study medication. Acute ROP data were collected on 755 infants. Logistic regression analysis, with control for immaturity, oxygen exposure, and other illness risk factors, showed a decrease in incidence of ROP in vitamin E-treated infants (p = 0.003, all infants; p = 0.035, infants weighing less than or equal to 1500 gm at birth). Among the 424 infants weighing less than or equal to 1500 gm at birth, the age at enrollment influenced treatment effect (age day 0 to 1, p = 0.006 (n = 288) vs age day 2 to 5, p greater than 0.1 (n = 136]. Overall, 77.6% of infants with ROP had mild disease. Moderate to severe ROP was confined to infants weighing greater than or equal to 1500 gm at birth (25 given placebo, 25 given vitamin E), with progression to severe disease in nine placebo-treated versus three vitamin E-treated infants (p = 0.048). The incidence of severe ROP per se was not significantly decreased (all birth weights, p = 0.086; less than or equal to 1500 gm birth weight, p = 0.080); the sample size was too small, however, to assess this end point adequately. An increased incidence of sepsis and late-onset necrotizing enterocolitis was found among vitamin E-treated infants weighing less than or equal to 1500 gm at birth who received study medication for greater than or equal to 8 days (p = 0.006). Because most ROP is mild in degree and regresses completely, the risk/benefit ratio of pharmacologic prophylaxis for ROP is unfavorable. Treatment of moderate and severe ROP with vitamin E above physiologic serum levels (greater than 3 mg/dl) appears promising and should be further investigated. The interpretation of cicatricial outcome was confounded by the small number of patients involved and by subsequent treatment of severe ROP in placebo-treated infants with vitamin E.
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Abstract
The proliferation and differentiation of trophoblast cells is under the control of a variety of hormones and growth factors and is influenced by nutrient availability. The intracellular signaling pathways acting downstream of these mitogenic factors and nutrients to regulate trophoblast proliferation and placental development are poorly understood. Immortalized human trophoblast cells were used (HTR-8/SVneo) to investigate trophoblast proliferation in response to angiopoietin-2 (Ang-2), a major angiogenic factor and glucose (a major nutrient). Trophoblast cell proliferation was induced through activation of the phosphatidylinositol-3 (PI-3) kinase and the mammalian target of rapamycin (mTOR) signaling pathways, following Tie-2 receptor activation. Glucose also stimulated trophoblast cell proliferation through mTOR signaling. Ang-2 activated mTOR via PI-3 kinase-dependent signaling; whereas glucose-mediated mTOR activation was PI-3 kinase-independent and involved a novel nutrient sensor, glutamine fructose-6-phosphate amidotransferase (GFAT). Metabolites of the GFAT reaction acted upstream of mTOR and functioned as a nutrient sensor to regulate trophoblast cell proliferation in response to glucose. Overall, the results show that growth factor and nutrient signaling converge at tuberin, an upstream regulator of mTOR and that mTOR functions as an important placental growth signaling sensor. These results are the first to link mTOR with GFAT metabolites as nutrient sensors for trophoblast cell proliferation.
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Research Support, U.S. Gov't, P.H.S. |
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Doheny DO, Brin MF, Morrison CE, Smith CJ, Walker RH, Abbasi S, Müller B, Garrels J, Liu L, De Carvalho Aguiar P, Schilling K, Kramer P, De Leon D, Raymond D, Saunders-Pullman R, Klein C, Bressman SB, Schmand B, Tijssen MAJ, Ozelius LJ, Silverman JM. Phenotypic features of myoclonus-dystonia in three kindreds. Neurology 2002; 59:1187-96. [PMID: 12391346 DOI: 10.1212/wnl.59.8.1187] [Citation(s) in RCA: 67] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
BACKGROUND Myoclonus-dystonia (M-D) is a movement disorder with involuntary jerks and dystonic contractions. Autosomal dominant alcohol-responsive M-D is associated with mutations in the epsilon-sarcoglycan gene (SGCE) (six families) and with a missense change in the D2 dopamine receptor (DRD2)gene (one family). OBJECTIVE To investigate the clinical phenotype associated with M-D including motor symptoms, psychiatric disorders, and neuropsychological deficits. METHODS Fifty individuals in three M-D families were evaluated and a standardized neurologic examination and DNA analysis were performed. Psychiatric profiles were established with the Diagnostic Interviews for Genetic Studies (DIGS) and the Yale-Brown Obsessive-Compulsive Scale (YBOCS). Cognition was evaluated with standardized neuropsychological tests. RESULTS Distinct truncating mutations in the SGCE gene were identified in each family. Additionally, a missense alteration in the DRD2 gene was previously found in one family. Motor expression was variable, with onset of myoclonus or dystonia or both affecting the upper body and progression to myoclonus and dystonia in most cases. Psychiatric profiles revealed depression, obsessive-compulsive disorder, substance abuse, anxiety/panic/phobic disorders, and psychosis in two families, and depression only in the third family. Averaged scores from cognitive testing showed impaired verbal learning and memory in one family, impaired memory in the second family, and no cognitive deficits in the third family. CONCLUSIONS Cognitive deficits may be associated with M-D. Psychiatric abnormalities correlate with the motor symptoms in affected individuals. Assessment of additional M-D families with known mutations is needed to determine whether these are characteristic phenotypic manifestations of M-D.
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Greenspan JS, Abbasi S, Bhutani VK. Sequential changes in pulmonary mechanics in the very low birth weight (less than or equal to 1000 grams) infant. J Pediatr 1988; 113:732-7. [PMID: 3171798 DOI: 10.1016/s0022-3476(88)80391-3] [Citation(s) in RCA: 61] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Pulmonary function tests were performed on 36 very low birth weight neonates (birth weight less than or equal to 1000 gm, gestational age less than or equal to 30 weeks, appropriate size for gestational age) from birth until 8 weeks of age. Tidal airflow was measured by means of a pneumotachygraph, and the transpulmonary pressure changes were determined by the esophageal balloon technique. Pulmonary mechanics and energetics were calculated by the least mean square analysis technique at 1/2, 1, 2, 4, 6, and 8 weeks of age. Compliance was lowest at 2 weeks and subsequently increased linearly (at approximately 0.1 ml/cm H2O/wk). When compliance was based on body weight, however, no change was noted with advancing age. Resistance was greatest at 2 weeks and subsequently decreased. The infants maintained a normal minute ventilation with a slightly increased resistive work of breathing. Despite our ability to wean 53% of the infants to room air by 8 weeks, none of them had pulmonary mechanics considered normal for term infants. Infants with and without bronchopulmonary dysplasia (BPD) had similar patterns of pulmonary development. At 8 weeks of age, the pulmonary mechanics in infants with BPD who had been weaned to room air were comparable to those in infants without BPD, an observation that calls into question the rationale for defining BPD at 4 weeks in this population. These data suggest that such pulmonary function profiles provide evidence of persistent lung parenchymal abnormalities.
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Blondheim O, Abbasi S, Fox WW, Bhutani VK. Effect of enteral gavage feeding rate on pulmonary functions of very low birth weight infants. J Pediatr 1993; 122:751-5. [PMID: 8496756 DOI: 10.1016/s0022-3476(06)80021-1] [Citation(s) in RCA: 55] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
To compare the effects of intermittent and continuous feedings on pulmonary function, we studied 24 very low birth weight neonates (mean +/- SD: birth weight, 1.2 +/- 0.3 kg; gestational age, 30.5 +/- 1.1 weeks) at 2 to 4 weeks of age. All infants had a previous diagnosis of respiratory distress syndrome but no subsequent diagnosis of bronchopulmonary dysplasia. Pulmonary mechanics were measured before the beginning of intermittent or continuous feedings and 10 minutes after each meal was completed. Twelve infants were randomly assigned to intermittent and 12 to continuous feedings. These infants had similar birth weight, gestational age, study age, and baseline lung function. After intermittent feedings, there was a significant decrease in tidal volume (38%), minute ventilation (44%), and dynamic compliance (28%), whereas pulmonary resistance increased significantly (100%). In comparison, the pulmonary function data remained unchanged after continuous feedings. These data demonstrate that intermittent feeding of very low birth weight infants can lead to airflow and respiratory instability. These adverse effects appear to be dependent on the rate that feedings are administered. A slower pace of feeding may be more advantageous for infants prone to respiratory instability.
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Clinical Trial |
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55 |
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Abdolahad M, Janmaleki M, Mohajerzadeh S, Akhavan O, Abbasi S. Polyphenols attached graphene nanosheets for high efficiency NIR mediated photodestruction of cancer cells. MATERIALS SCIENCE & ENGINEERING. C, MATERIALS FOR BIOLOGICAL APPLICATIONS 2012; 33:1498-505. [PMID: 23827601 DOI: 10.1016/j.msec.2012.12.052] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/01/2012] [Revised: 11/04/2012] [Accepted: 12/17/2012] [Indexed: 11/17/2022]
Abstract
Green tea-reduced graphene oxide (GT-rGO) sheets have been exploited for high efficiency near infrared (NIR) photothermal therapy of HT29 and SW48 colon cancer cells. The biocompatibility of GT-rGO sheets was investigated by means of MTT assays. The polyphenol constituents of GT-rGO act as effective targeting ligands for the attachment of rGO to the surface of cancer cells, as confirmed by the cell granularity test in flow cytometry assays and also by scanning electron microscopy. The photo-thermal destruction of higher metastatic cancer cells (SW48) is found to be more than 20% higher than that of the lower metastatic one (HT29). The photo-destruction efficiency factor of the GT-rGO is found to be at least two orders of magnitude higher than other carbon-based nano-materials. Such excellent cancer cell destruction efficiency provided application of a low concentration of rGO (3 mg/L) and NIR laser power density (0.25 W/cm(2)) in our photo-thermal therapy of cancer cells.
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Research Support, Non-U.S. Gov't |
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54 |
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Bhutani VK, Abbasi S, Long WA, Gerdes JS. Pulmonary mechanics and energetics in preterm infants who had respiratory distress syndrome treated with synthetic surfactant. J Pediatr 1992; 120:S18-24. [PMID: 1735846 DOI: 10.1016/s0022-3476(05)81228-4] [Citation(s) in RCA: 52] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Pulmonary mechanics and energetics were determined in 32 neonates with respiratory distress syndrome, who were randomly assigned to receive treatment with an exogenous synthetic surfactant, Exosurf Neonatal, or air placebo. Pulmonary mechanics were measured before and 2 hours after surfactant (n = 13) or air placebo (n = 19) treatment, then longitudinally at 24, 48, and 72 hours after treatment, and again at 7, 14, and 28 days of age. There were no significant differences in the values for pulmonary mechanics or energetics 2 hours after the first dose of surfactant. Improvement in pulmonary mechanics was apparent 24 hours after surfactant treatment, when dynamic compliance was 36% greater than in the placebo group (p less than 0.03). Lung compliance values were also higher in surfactant-treated infants 48 and 72 hours after treatment, with a maximal increase of 64% at 7 days of age (p less than 0.03). Surfactant treatment also caused a significant decrease in total pulmonary resistance at 48 and 72 hours after initial treatment and at 14 days of age (p less than 0.04). Similarly, a decrease in flow-resistive work of breathing was demonstrated 24, 48, and 72 hours after surfactant treatment. At 28 days of age, pulmonary mechanics were not different in the two groups. We conclude that beneficial effects of surfactant on pulmonary mechanics were not apparent 2 hours after dosing but were evident 24 hours after dosing and persisted for the first 7 to 14 days of life.
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Alighourchi H, Barzegar M, Abbasi S. Effect of gamma irradiation on the stability of anthocyanins and shelf-life of various pomegranate juices. Food Chem 2008; 110:1036-40. [DOI: 10.1016/j.foodchem.2008.03.013] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2007] [Revised: 02/18/2008] [Accepted: 03/04/2008] [Indexed: 10/22/2022]
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Bhutani VK, Abbasi S. Relative likelihood of bronchopulmonary dysplasia based on pulmonary mechanics measured in preterm neonates during the first week of life. J Pediatr 1992; 120:605-13. [PMID: 1552402 DOI: 10.1016/s0022-3476(05)82491-6] [Citation(s) in RCA: 47] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
We studied 143 low birth weight infants (less than or equal to 1500 gm) with respiratory distress syndrome who required mechanical ventilation, and determined the efficacy of using the alterations in pulmonary mechanics (measured at 1 to 3 days, 4 to 7 days, 2 weeks, and 4 weeks) as possible predictors for the subsequent diagnosis of bronchopulmonary dysplasia (BPD). The sensitivity and specificity of pulmonary compliance and resistance as predictors of BPD were ascertained by logistic regression correlation (p less than 0.01) and receiver operating characteristic curves. With these pulmonary mechanics data and logistic discriminant analysis techniques, we developed BPD prediction models based on pulmonary mechanics, measured between 4 and 7 days of age, to define the likelihood ratio for the subsequent diagnosis of BPD. Eight different BPD prediction models were developed by using combinations of four vectors (pulmonary compliance, total pulmonary resistance, birth weight, gestational age), and each model was validated in a subsequent low birth weight study population (n = 53). All models were deemed accurate for negative prediction of BPD. The models dependent on gestational age and dynamic pulmonary compliance had the highest positive predictive accuracy. The predictive impact of total pulmonary resistance appeared to be minimal. These prediction models may be used to calculate the likelihood ratio for a subsequent BPD diagnosis and thereby objectively categorize both the risk and the magnitude of acute lung injury by the first week of life.
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Abstract
Energetics and mechanics of sucking in preterm and term neonates were determined by simultaneous records of intraoral pressure, flow, volume, and work of individual sucks. Nine term infants (mean postconceptional age: 38.6 +/- 0.7 SD weeks; mean postnatal age: 18.4 +/- 6.1 SD days) and nine preterm infants (mean postconceptional age: 35.2 +/- 0.7 SD weeks; mean postnatal age: 21.9 +/- 5.4 SD days) were studied under identical feeding conditions. Preterm infants generated significantly lower peak pressure (mean values of 48.5 cm H2O compared with 65.5 cm H2O in term infants; P less than 0.01), and the volume ingested per such was generally less than or equal to 0.5 mL. Term infants demonstrated a higher frequency of sucking, a well-defined suck-pause pattern, and a higher minute consumption of formula. Energy and caloric expenditure estimations revealed significantly lower work performed by preterm infants for isovolumic feeds (1190 g/cm/dL in preterm infants compared with 2030 g.cm/dL formula ingested in term infants; P less than 0.01). Furthermore, work performed by term infants was disproportionately higher for volumes greater than or equal to 0.5 mL ingested. This study indicates that preterm infants expend less energy than term infants to suck the same volume of feed and also describes an objective technique to evaluate nutritive sucking during growth and development.
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Comparative Study |
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Akinbi H, Abbasi S, Hilpert PL, Bhutani VK. Gastrointestinal and renal blood flow velocity profile in neonates with birth asphyxia. J Pediatr 1994; 125:625-7. [PMID: 7931888 DOI: 10.1016/s0022-3476(94)70024-9] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Pulsed Doppler ultrasound blood flow profiles were studied, before the initiation of enteral feedings, in 23 neonates with birth asphyxia. We observed a significant direct correlation between the reduction of peak velocity and increased resistance in the renal and superior mesenteric arteries to the severity of asphyxia (r = 0.8; p < 0.05); the changes often persisted up to 3 days of age. Longitudinal evaluation of flow in these vessels might help to time the initiation of enteral nutrition in neonates with asphyxia.
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Sosulski R, Abbasi S, Bhutani VK, Fox WW. Physiologic effects of terbutaline on pulmonary function of infants with bronchopulmonary dysplasia. Pediatr Pulmonol 1986; 2:269-73. [PMID: 3774383 DOI: 10.1002/ppul.1950020504] [Citation(s) in RCA: 37] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
This study defines the physiologic changes in pulmonary mechanics induced by subcutaneous terbutaline administration in ventilator-dependent infants with severe bronchopulmonary dysplasia (BPD). Eight such infants (mean +/- SEM weight = 2.56 +/- 0.32 kg, postnatal age = 13.0 +/- 3.2 weeks) were chosen for the study. Pulmonary mechanics and arterial blood gases were measured in the control state and at 30 and 60 minutes following the subcutaneous injection of 5 micrograms/kg terbutaline. There was a significant (p less than 0.001) improvement in lung compliance from baseline values at 30 minutes and at 60 minutes (38%). A significant (p less than 0.05) decrease of 23% in the average pulmonary resistance at 30 minutes and a 26% decrease at 60 minutes from control values were observed. An increase in the I/E ratio occurred in all patients at 60 minutes (p less than 0.01). In addition, clinical improvement was noted in six of eight infants. Administration of terbutaline demonstrated a significant improvement in the pulmonary mechanics of infants with severe BPD.
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Chesney PJ, Wilimas JA, Presbury G, Abbasi S, Leggiadro RJ, Davis Y, Day SW, Schutze GE, Wang WC. Penicillin- and cephalosporin-resistant strains of Streptococcus pneumoniae causing sepsis and meningitis in children with sickle cell disease. J Pediatr 1995; 127:526-32. [PMID: 7562271 DOI: 10.1016/s0022-3476(95)70107-9] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
OBJECTIVE We investigated the possibility that antimicrobial-resistant pneumococci were causing invasive disease in children with sickle-cell disease (SCD). STUDY DESIGN Records of all children with SCD observed at the Mid-South Sickle Cell Center (MSSCC) at LeBonheur Children's Medical Center were reviewed from January 1990 to June 1994. Children with SCD and pneumococcal sepsis were identified. The Streptococcus pneumoniae isolates from these children were examined for serotype and antimicrobial susceptibilities. Two additional children not observed in the MSSCC had pneumococcal sepsis caused by penicillin-resistant isolates and were also included. RESULTS Antimicrobial susceptibility testing of the six penicillin-resistant isolates revealed that four were resistant to trimethoprim-sulfamethoxazole, two to erythromycin, and one to clindamycin. The two isolates that were resistant to ceftriaxone also were multiply resistant. From the MSSCC, 26 children had pneumococcal sepsis during the 4 1/2-year period studied. Five of these children (19%) died. Four (15%), including one who died, were infected with penicillin-resistant strains. CONCLUSION Pneumococcal sepsis, meningitis, and infections of other foci in children with SCD may be caused by S. pneumoniae that is resistant to one or more antimicrobial agents, including penicillin. The addition of vancomycin to the antibiotics currently used for initial management should be considered in areas where the antibiotic resistance of S. pneumoniae is prevalent.
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Case Reports |
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Abstract
Pulmonary mechanics and energetics were determined in 33 healthy low birthweight infants (less than 1,500 g, 28-34 weeks gestation) who had never received ventilatory support. Tidal volume, dynamic pulmonary compliance, pulmonary resistance, pressure-volume relationships, and tidal flow-volume measurements were obtained by pneumotachography and the esophageal balloon technique. Standardized data collection and software data analysis by least mean squares technique yielded data at 0.5, 1, 2, and 4 weeks postnatally, as a function of gestational age (less than 30, 30-32, and greater than 32 weeks gestation). Relatively stable values were obtained for tidal volume and minute ventilation (normalized for body weight); these were associated with values of peak-to-peak esophageal pressure significantly (P less than 0.001) increasing from 4.4 +/- 0.3 SEM cmH2O at 0.5 weeks to 8.1 +/- 0.8 SEM cmH2O at 4 weeks of age. Dynamic pulmonary compliance ranged from 2.0 to 2.4 mL/cmH2O in the first 4 weeks of life. When normalized for weight, compliance decreased with age, which may suggest a slower pulmonary maturation as compared to increase of body weight. Mean pulmonary resistance decreased from 62.9 cmH2O/L/s at less than 30 weeks gestation to 32.5 cmH2O/L/s at greater than 32 weeks gestation, 0.5 weeks postnatally. Pulmonary resistance peaked at 2 weeks postnatally (P less than 0.05), at all gestational ages, then decreased. Changes in pulmonary mechanics resulted in increasing resistive work of breathing. Our findings suggest a postnatal retardation of pulmonary and airway growth, relative to gestation maturation. These data can provide an objective base of comparison for data in sick, low birthweight neonates.
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Gerson A, Abbasi S, Johnson A, Kalchbrenner M, Ashmead G, Bolognese R. Safety and efficacy of long-term tocolysis with indomethacin. Am J Perinatol 1990; 7:71-4. [PMID: 2294913 DOI: 10.1055/s-2007-999450] [Citation(s) in RCA: 31] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Indomethacin was utilized in 24 pregnancies (31 exposed fetuses) in preterm labor who labored despite intravenous tocolysis. The mean gestational age at the start of indomethacin therapy was 25.1 weeks (+/- 4.4), mean duration of indomethacin therapy was 43.9 days (+/- 31.4), mean gestational age at delivery 33.1 weeks (+/- 3.7). Neonatal follow-up revealed the same incidence of complications in these indomethacin-exposed infants, when they were compared with all other infants born in the same time period and exposed to intravenous tocolytics only when matched for gestational age at delivery.
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Al-Tawfiq JA, Hinedi K, Abbasi S, Babiker M, Sunji A, Eltigani M. Hematologic, hepatic, and renal function changes in hospitalized patients with Middle East respiratory syndrome coronavirus. Int J Lab Hematol 2017; 39:272-278. [PMID: 28444873 PMCID: PMC7165514 DOI: 10.1111/ijlh.12620] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2016] [Accepted: 11/21/2016] [Indexed: 12/24/2022]
Abstract
Background There are no longitudinal data on the changes in hematologic, hepatic, and renal function findings in patients with Middle East respiratory syndrome coronavirus (MERS‐CoV) infection. Methods This is a retrospective cohort study of 16 MERS‐CoV patients, to describe the hematological, hepatic, and renal findings of patients with MERS‐CoV. Results During the 21 days of observation, there was no significant change in the hepatic panel or creatinine tests. There was a significant increase in the mean ± SD of the white blood cell count from 8.3 ± 4.6 to 14.53 ± 7 (P value = 0.001) and an increase in mean ± SD of the absolute neutrophil count from 6.33 ± 4.2 to 12 ± 5.5 (P value = 0.015). Leukocytosis was observed in 31% (5/16) of the patients on day 1 and in 80% (4/5) on day 21. Transient leukopenia developed in 6% (1/16) of the patients on day 1 and in 13% (1/8) on day 8. None of the patients had neutropenia. Lymphopenia was a prominent feature with a rate of 44% (7/16) of the patients on day 1 and 60% (3/5) on day 21. Lymphocytosis was not a feature of MERS‐CoV infection. Thrombocytopenia developed in 31% (5/16) of the patients on day 1 and 40% (2/5) on day 21. Thrombocytosis was not a prominent feature and was observed in 6% (1/16) of the patients on day 1 and 17% (1/6) on day 9. Conclusions Patients with MERS‐CoV infection showed variable hematologic parameters over time. Lymphocytosis and neutropenia were not features of MERS‐CoV infection.
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Journal Article |
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Abstract
Nineteen infants (mean +/- SD gestational age 30 +/- 2 weeks, birth weight 1.28 +/- 0.53 kg) with Staphylococcus epidermidis bacteremia were found on retrospective chart review to have had signs and symptoms of acute enterocolitis. This S. epidermidis-associated enterocolitis constituted 37% of the 51 cases of enterocolitis and 23% of the 81 cases of S. epidermidis sepsis during the study period. S. epidermidis-associated enterocolitis was relatively mild compared with other forms of enterocolitis. Although abdominal radiographs showed markedly abnormal bowel gas patterns with distended bowel loops and bowel wall edema, only one infant had pneumatosis intestinalis and none had portal venous or free intraperitoneal gas. Only three infants had neutropenia, and five had thrombocytopenia. None of these infants required surgical intervention. Although bloody stools often persisted for weeks, none of the neonates had prolonged feeding intolerance or development of a stricture. We conclude that S. epidermidis infection is commonly associated with a mild form of enterocolitis in the neonate and that this association should be considered when selecting antibiotics for therapy.
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