Biomedical subjects

Jyoti Krishna

Publications and source records attributed to Jyoti Krishna.

5 recordsLinked to original sources

PubMed2006

Sleep studies: which technologies?

The demand for sleep services for young patients has escalated due to the increased recognition of pediatric sleep disorders over the past two decades. In this overview, we will highlight the essentials of pediatric sleep monitoring and stress particular issues that require the awareness of clinicians evaluating children for sleep disorders. While many techniques used in the "adult" sleep centers may suffice for the older adolescent patient, specific tailoring of the design of the sleep center to younger children and their families, and attention to the age-sensitive components of sleep data acquisition and interpretation are increasingly important in younger children. Several promising newer technologies and their potential for future clinical utility will be also reviewed.

Blood Pressure Determination↗

PubMed2006

Urinary protein expression patterns in children with sleep-disordered breathing: preliminary findings.

BACKGROUND: Obstructive sleep apnea (OSA) is the most common form of sleep-disordered breathing, with almost 15 million Americans affected and many more at risk. Current diagnostic approach to OSA requires polysomnography, which is laborious, onerous, and time-consuming. There is ample evidence that inflammatory responses to the perturbations associated with OSA trigger a variety of genes and signaling cascades that ultimately lead to end-organ injury and changes in kidney function and protein expression. The aim of this study was therefore to analyze proteins in human urine and assess whether differential expression of particular proteins is associated with the presence of OSA. METHODS: Eleven OSA and 11 control children between the ages of three and 14 (males=17; females=5) underwent overnight sleep studies followed by a first-morning urine sample. Proteomic analysis of urine samples yielded a unique map of proteins, of which, five spots were selected for further analysis due to their significant intensity differences between OSA and control groups. RESULTS: Mass spectrometry followed by peptide mass fingerprinting conclusively identified four of the five spots as gelsolin, perlecan (a heparan sulfate proteoglycan), albumin, and immunoglobulin (P<0.05 and protein scores>67). CONCLUSIONS: Overall, increased expression of gelsolin and perlecan in the urinary proteome of children with OSA suggests that the episodic hypoxia associated with OSA may lead to changes in protein permeability or alternatively to increased catabolism of these proteins and their excretion in urine.

Body Mass Index↗

PubMed2006

Urinary F2-isoprostane metabolite levels in children with sleep-disordered breathing.

Oxidant stress-related mechanisms have been proposed as a major contributor to the increased prevalence of cardiovascular morbidity in adult patients with sleep-disordered breathing. Isoprostanes provide a reliable biomarker of oxidant injury in vivo. The purpose of the present study was to examine the hypothesis that oxidant stress, as evidenced by increased levels of F2-isoprostane metabolites (IsoP-m) in urine, is present in children with a spectrum of sleep-disordered breathing. Assays were performed on urinary samples obtained from each of 47 pediatric patients immediately upon awakening after standard overnight polysomnography. Of the subjects, 15% had mild, 9% had moderate, and 6% had severe sleep-disordered breathing. After controlling for correlations between BMI and IsoP-m and SpO2 values, IsoP-m values were unrelated to any polysomnographic measures. The absence of increased levels of urinary F2-isoprostane metabolites in children with sleep-disordered breathing suggests that oxidative stress is not a significant feature of pediatric sleep-disordered breathing.

Body Mass Index↗

PubMed2006

Persistence of obstructive sleep apnea syndrome in children after adenotonsillectomy.

OBJECTIVE: To investigate the relative contribution of various risk factors to the surgical outcome of adenotonsillectomy for obstructive sleep apnea syndrome in children. STUDY DESIGN: Children (n = 110; mean age, 6.4 +/- 3.9 years) underwent two polysomnographic evaluations before and after adenotonsillectomy. In addition, 22 control children were studied. History for allergy and family history of sleep-disordered breathing was taken before each polysomnographic evaluation. RESULTS: Significant changes in sleep stage percentages and sleep fragmentation were found in the postsurgery study compared with the presurgery study; 25% of the children had apnea/hypopnea index (AHI) </=1, 46% had AHI >1 and <5, and 29% had AHI >/=5 in the postsurgery study. The frequency of subjects with AHI </=1 after surgery was significantly lower among obese subjects (P < .05). Comparison between the children who had AHI </=1 after surgery and 22 control children showed complete normalization of sleep architecture after surgery. CONCLUSIONS: Adenotonsillectomy yields improvements in respiratory abnormalities in children with obstructive sleep apnea syndrome. Complete normalization occurs in only 25% of the patients. Obesity and AHI at diagnosis are the major determinant for surgical outcome. When normalization of respiratory measures occurs after surgery, normalization of sleep architecture will also ensue.

Adenoidectomy↗

PubMed2006

Inflammatory mediators in exhaled breath condensate of children with obstructive sleep apnea syndrome.

BACKGROUND: Upper airway inflammation is now recognized in adults with obstructive sleep apnea (OSA) syndrome. However, the role played by eicosanoids such as leukotrienes and prostaglandins is unclear. OBJECTIVE: To investigate whether eicosanoids are measurable in exhaled breath condensate (EBC), and to determine whether differences in these inflammatory mediators emerge among children with and without sleep-disordered breathing (SDB). METHODS: EBC was collected from 50 consecutive snoring children undergoing overnight polysomnography for suspected SDB, and from 12 nonsnoring control subjects. Prostaglandin E2 (PGE2), leukotriene B4 (LTB4), and cysteinyl leukotrienes (cys-LTs: leukotriene C4 [LTC4]/leukotriene D4 [LTD4]/leukotriene E4 [LTE4]) EBC levels were analyzed using enzyme-linked immunosorbent assay. RESULTS: LTB4 levels were elevated in children with an apnea-hypopnea index (AHI) > 5/h (SDB; 97.6 +/- 6.3 pg/mL) compared to children with an AHI < 5/h (mild SDB; 66.4 +/- 19.1 pg/mL; p < 0.01) and control subjects (27.8 +/- 3.7 pg/mL; p < 0.01). Similarly, cys-LT (LTC4/LTD4/LTE4) concentrations were also increased in SDB (45.1 +/- 10.6 pg/mL in SDB vs 27.6 +/- 8.3 pg/mL in mild SDB, and 15.7 +/- 7.6 pg/mL in control subjects; p < 0.01). In contrast, PGE2 concentrations were similar among the three groups. CONCLUSIONS: Inflammatory mediators such as leukotrienes and prostaglandins can be readily quantified in EBC collected from the upper airway of children. Disease severity-dependent increases in leukotriene concentrations (LTB4 and LTC4/LTD4/LTE4) emerge among children and may serve as a noninvasive tool in the clinical assessment of these children.

Adolescent↗