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Biomedical subjects

J Janosky

Publications and source records attributed to J Janosky.

34 records · Page 2Linked to original sources
PubMed1994

Prediction of response to methylphenidate among children with ADHD and mental retardation.

OBJECTIVE: The primary purpose of this study was to predict stimulant medication response among children with attention-deficit hyperactivity disorder (ADHD) and mental retardation (MR). METHOD: Forty-seven children with ADHD and MR (IQs of 48 to 77) served as subjects; ages ranged from 6.1 to 12.5 years. Subjects participated in a double-blind, placebo-controlled study of two doses of methylphenidate (0.3 and 0.6 mg/kg per dose) and a placebo. Data were collected in each child's weekday classroom and a Saturday laboratory classroom. Stepwise multiple regression analyses were used to predict drug responses in both settings. RESULTS: Higher parent ratings of impulsivity and activity level at baseline were associated with greater gains in weekday classroom dependent measures. Similarly, higher weekday teacher measures of activity level, impulsivity, inattention, and conduct problems at baseline were related to improvement on Saturday laboratory classroom dependent measures. Finally, gender, race, and socioeconomic status (SES) were found to be important predictors, with males, Caucasian subjects, and subjects from families of higher SES more likely to evidence clinical gains on a number of variables than other subjects. CONCLUSION: These results were generally consistent with research conducted among children with ADHD but without MR. However, factors such as race and conduct problems appear to have predictive utility specific to children with MR.

Attention Deficit Disorder with Hyperactivity↗
PubMed1994

Transcranial Doppler ultrasonography with induction of anesthesia for neurosurgery.

Intracranial hypertension can occur with induction of anesthesia; however, the clinical significance of this is unclear. We used transcranial Doppler (TCD) ultrasonography in neurosurgical patients during induction of anesthesia and endotracheal intubation to assess the incidence of high intracranial pressure (ICP) waveforms and to correlate TCD observations with specific anesthetics and anesthetic regimens. The middle cerebral artery was monitored by TCD during induction of anesthesia and endotracheal intubation in 196 patients undergoing elective neurosurgery. Middle cerebral artery blood flow velocity (MCABFV) and physiologic data were observed continuously and recorded at the following times: preinduction, induction, intubation, and postintubation. Induction with thiopental or etomidate decreased MCABFV, intubation increased MCABFV, and postintubation ventilation decreased MCABFV. MCABFV was higher throughout the induction sequence in the 92 patients with tumors. Although there were numerous individual exceptions, changes in mean arterial pressure correlated statistically with changes in MCABFV. No patient had an end-diastolic flow velocity of 0. We reached the following conclusions: (a) TCD is a straightforward modality that can be used to monitor dynamic cerebrovascular events during induction of anesthesia; (b) MCABFV is increased with brain tumors; (c) thiopental and etomidate rapidly decrease and intubation rapidly increases MCABFV; and (d) routine TCD monitoring for high ICP waveforms during anesthetic induction for routine elective neurosurgery appears to be unwarranted.

Adult↗
PubMed1994

Extracorporeal membrane oxygenation for pediatric respiratory failure: five-year experience at the University of Pittsburgh.

OBJECTIVES: To describe the etiology, respiratory severity of illness, and outcome in patients with pediatric respiratory failure who were treated with extracorporeal membrane oxygenation (ECMO). To identify predictors of death, and to compare our morbidity and mortality rates with those rates of a previously reported series of patients with pediatric respiratory failure managed conventionally. DESIGN: Survey, case series. SETTING: Intensive care unit in a tertiary care pediatric hospital. PATIENTS: Twenty-eight pediatric patients (3 wks to 20 yrs of age) who underwent ECMO for pediatric respiratory failure between 1985 and 1991. MEASUREMENTS AND MAIN RESULTS: Thirteen (46%) of the 28 patients survived. The most common diagnoses were adult respiratory distress syndrome and nonspecific pneumonitis. Multiple organ system failure occurred in only four (14%) patients; most patients died of respiratory failure. The occurrence of persistent airleak during ECMO was significantly greater in nonsurvivors than in survivors. Furthermore, nonsurvivors had significantly less response to lung reexpansion maneuvers compared with survivors, as measured by a calculated compliance index (effective tidal volume/mean airway pressure x 100). The mortality rate was comparable with those rates of other published studies of conventionally managed and ECMO-treated patients with pediatric respiratory failure. Moreover, our patients appeared to exhibit more severe respiratory failure at the start of ECMO than those patients in other studies. CONCLUSIONS: ECMO appears to be a rational therapy for patients with pediatric respiratory failure who are likely to die with continued conventional management. Recovery of lung function by the end of the first week of ECMO may be a favorable prognostic indicator. Persistent airleak may be a nonfavorable prognostic indicator.

Adolescent↗
PubMed1993

Continuous intrathecal baclofen infusion for spasticity of cerebral origin.

OBJECTIVE: To determine if continuous intrathecal baclofen infusion (CIBI) would provide continuous relief of spasticity in patients with spasticity of cerebral origin, especially children with cerebral palsy. DESIGN: Prospective, unblinded trial, before and after CIBI. SETTING: Children's Hospital of Pittsburgh (Pa). PATIENTS: Thirty-seven patients, 5 to 27 years of age, with spasticity of cerebral origin. INTERVENTION: Continuous intrathecal baclofen infusion for 3 to 48 months. MAIN OUTCOME MEASURES: Muscle tone, range of motion, upper extremity timed tasks, activities of daily living (ADLs). RESULTS: Six and 12 months after CIBI, muscle tone was significantly decreased in the upper (P = .04) and lower (P = .001) extremities. There was a significant relationship between baclofen dosage and muscle tone in the upper (P = .02) and lower (P = .001) extremities. Hamstring motion, upper extremity function, and ADLs were significantly improved in 25 patients who were capable of self-care. CONCLUSION: Spasticity of cerebral origin can be effectively treated with CIBI. Because baclofen dosages can be titrated for the desired clinical response, CIBI is particularly useful for patients who need some spasticity to stand and ambulate.

Adolescent↗
PubMed1993

The relationship of physical fitness to lipid and lipoprotein(a) levels in adolescents with IDDM.

OBJECTIVE--Increased physical activity and physical fitness are recommended therapeutic modalities in addition to insulin and diet in the management of children with IDDM. The aim of this study was to assess the fitness levels of adolescents with IDDM compared with healthy control subjects and to evaluate the relationship between physical fitness and metabolic control. RESEARCH DESIGN AND METHODS--We studied 59 patients with IDDM, 28 boys and 31 girls, age 15.6 +/- 2.5 yr, duration of diabetes 7.6 +/- 3.5 yr, HbA1 10.6 +/- 2.1% (mean +/- SD), and compared them with 18 healthy, nondiabetic control subjects, 9 boys and 9 girls, matched for age, BMI, and Tanner stage. Physical fitness was measured by VO2max during progressive bicycle ergometry. HbA1 was used to determine glycemic control. Lipid profile included fasting total cholesterol, HDL, LDL, Lp(a), and TG levels. RESULTS--Patients with IDDM had lower VO2max levels than control subjects (33.7 +/- 7.0 vs. 41.0 +/- 10.4 ml.kg-1.min-1, P = 0.001). Males with IDDM had lower VO2max than male control subjects, but diabetic and control females showed no difference. In IDDM patients, VO2max correlated inversely with HbA1, insulin dose, cholesterol, LDL, TGs, and Lp(a), but did not correlate with HDL, which correlated inversely with BMI. CONCLUSIONS--We conclude that the state of physical fitness is an important correlate of lipid levels and Lp(a) in adolescents with IDDM. We speculate that higher physical fitness levels in adolescents with IDDM may decrease the risk of CVD through modulating lipid levels.

Adolescent↗
PubMed1993

Compliance with allergen immunotherapy.

Immunotherapy has been used for the treatment of allergic rhinitis since the turn of this century. The purpose of this study was to assess the compliance with immunotherapy in a medical center. The charts of 315 patients aged 5 to 18 years, who were prescribed immunotherapy for treatment of allergic rhinitis for at least 1 year before the study, were selected by computer and reviewed. The first analysis consisted of using a log-linear analysis in order to investigate the relationship between source of payment (private or nonprivate), gender, and race. All main effects and interactions were entered into the model (P < .01). The second analysis consisted of using a log-linear analysis to investigate the relationship between the presence/absence of pollen, mold, mite, and animal IgE antibodies, and compliance (model, P < .05). Two hundred fifty-eight patients were private and 57 were nonprivate. Fifty-nine percent (n = 152) of private patients and 46% (n = 26) of nonprivate patients were compliant. Of the 315 patients with allergic rhinitis, 52 also had asthma and 34 had atopic dermatitis. Sixty-one percent of the asthmatic patients and 47% with atopic dermatitis were compliant. Compliance was not increased by the number of allergens to which a patient was allergic. Males were slightly more compliant than females, caucasians were more often private patients and non-whites were more often nonprivate patients. Private patients were more complaint with immunotherapy than nonprivate patients.

Adolescent↗
PubMed1992

Multivariate analysis of second trimester midfacial morphology in normal and cleft lip and palate human fetal specimens.

To better understand the contribution of congenital dysmorphogenesis to postnatal midfacial dysplasia in individuals with complete cleft lip and palate (CLP), a series of studies were undertaken to investigate age related changes in a number of midfacial components for a sample of 20 normal and 9 complete CLP second trimester fetal specimens. Using data from this sample, the present study assessed the complex multivariate relationships among these variables which represent the fetal normal and CLP midface. Ten variables were standardized relative to crown-rump length and used in Canonical Discriminant Function Analysis (CDFA). CDF analysis revealed that five variables best described the midface and accounted for 72% of the overall variance. These included nasal capsule length, nasal airway volume, premaxillary length, premaxillary volume, and tongue volume. Classification using the CDFA coefficients resulted in correct group membership assignment for 26 of 29 total specimens (89.66%), 8 of 9 cleft (88.9%), and 18 of 20 normal specimens (90.0%). These results suggest that by as early as the second trimester CLP fetuses have a significantly distinct set of midfacial morphological relationships. Some or all of these factors may be responsible for postnatal growth dysplasias noted in CLP individuals.

Cleft Lip↗
PubMed1992

Plate fixation of premaxillomaxillary suture and compensatory midfacial growth changes in the rabbit.

It has been suggested that rigid fixation of the developing craniofacial skeleton may lead to altered craniofacial growth. However, recent experimental studies have shown that microplate fixation of slow-growing calvarial sutures resulted in regional growth disturbances but had little effect on overall craniofacial growth. The present study was designed to assess the effects of microplate fixation of the more rapidly growing facial sutures on compensatory midfacial growth in the rabbit. Twenty-two 1.5-week-old rabbits were randomly divided into 2 groups: sham controls (n = 11) and animals with bilateral premaxillomaxillary suture fixation (n = 11). Fixation was accomplished using an intraoral approach, a 6-mm straight Luhr microplate, and two 2-mm long self-tapping screws across each suture. Serial lateral head radiographs were collected at 1.5, 3.5, 6, 12, and 18 weeks of age. Results revealed that by 3.5 weeks, animals with rigid fixation showed significantly shortened premaxillary lengths (p < 0.05), class III occlusal relationships, decreased midfacial heights, and abnormal palatocranial base angles compared with sham control animals. By 12 weeks of age, "catch-up" growth was evident in most dimensions in animals with fixation compared with shams. Gross examination of the cleaned and dried skulls revealed bony bridging across the premaxillomaxillary suture and osseous fracture lines extending superiorly from the site of screw fixation. Results demonstrated that rigid fixation of a rapidly growing facial suture did not impair long-term midfacial growth in the rabbit model and suggest that compensatory changes may have occurred at fracture lines from the self-tapping screws in these animals.

Adaptation, Physiological↗
PubMed1992

Effects and noneffects of methylphenidate in children with mental retardation and ADHD.

Stimulant medication efficacy was evaluated in 14 children with attention-deficit hyperactivity disorder and IQs of 48 to 74 in a double-blind crossover study of two methylphenidate doses and placebo. Dependent measures included behavioral ratings, work output, measures of learning, attention and impulsivity, and direct observation of peer social interactions. Nine children (64%) were methylphenidate-responders, based upon the Conners Hyperactivity Index. Significant gains in on-task behavior and attentional skills were noted with methylphenidate in comparison to placebo. No improvement on measures of learning or social interactions were observed. Results extend and replicate previous research conducted by the authors.

Attention Deficit Disorder with Hyperactivity↗
PubMed1992

Initial platelet deposition at the human microvascular anastomosis: effect on downstream platelet deposition to intact and injured vessels.

Initial platelet deposition (PD) in and around the region of a small-vessel anastomosis may set the stage for thrombosis and tissue loss. To study this problem, a human vessel model (human placental artery, HPA) has been designed to mimic the vascular injuries attendant on clinical microsurgery. To perform these studies, dissected lengths of human placental artery were treated to provide the following four types of injury: group I: control, dissected but otherwise uninjured (N = 5); group II: distal portion of vessel endothelium removed (N = 5); group III: central anastomosis, distal endothelium intact (N = 7); and group IV: central anastomosis, distal endothelium removed (N = 4). Vessels were perfused with 25 ml human whole blood for 17 +/- 5 s at an average shear rate of 536 s-1. Vessels in groups I to IV were segmented at 2-cm intervals, and the number of 111In-labeled platelets was measured. Data from the following groups of exposure zones were pooled and analyzed: endothelium intact, endothelium absent, anastomosis present, postanastomosis with endothelium intact, and postanastomosis with endothelium absent. Significant numbers of platelets were found to attach to intact endothelium, indicating that ischemia and microsurgical handling may augment platelet deposition to otherwise uninjured vessels. A similar degree of platelet deposition was measured after exposure of the subendothelium and perfusion, indicating that superficial subendothelial exposure in the absence of an additional prothrombotic stimulus may lead to no greater platelet deposition than occurs on slightly injured endothelium alone. Platelet deposition at anastomoses was strikingly elevated, although the anastomosis had no additive effect on platelet deposition to downstream endothelium.(ABSTRACT TRUNCATED AT 250 WORDS)

Anastomosis, Surgical↗
PubMed1991

Examination of the roles of glycoprotein Ib and glycoprotein IIb/IIIa in platelet deposition on an artificial surface using clinical antiplatelet agents and monoclonal antibody blockade.

The mechanism of platelet thrombus growth on an artificial surface is incompletely understood. While glycoprotein (GP)Ib and GPIIb/IIIa are required for normal attachment and thrombus formation on subendothelium, their roles in platelet deposition to artificial surfaces remain unclear. Using selected platelet inhibitors (aspirin [ASA], low molecular weight dextran, monoclonal antibodies 10E5 [v GPIIb/IIIa], and 6D1 [GPIb]) we examined the mechanism of platelet deposition to polyethylene (PE) surfaces under steady laminar and oscillatory flow conditions. Polyethylene-100 (PE-100) tubes (0.86 mm internal diameter) were perfused under steady laminar flow with citrated human whole blood reconstituted with 111indium-labeled platelets at 312 seconds-1 shear rate in the presence and absence of platelet inhibitors. The effect of oscillatory flow on platelet deposition was examined in a microwell system using 3/16-inch diameter discs of National Heart, Lung, and Blood Institute primary reference PE as the test surface. ASA and dextran did not significantly (P greater than .05) inhibit platelet deposition in laminar flow (not tested in oscillatory). Antibody 10E5 was a potent inhibitor (laminar less than 1%, P less than .0001, oscillatory less than 1.6%, P less than .01) of platelet deposition in both systems, and in this case, true adhesion (first attached layer) was blocked. Antibody 6D1 unexpectedly inhibited 70% of platelet deposition (P less than .01) in steady laminar flow and 56.5% in oscillatory flow (P less than .01). Scanning electron microscopy demonstrated platelets atop platelets in the controls, rare platelets in the 10E5 group, and a patchy monolayer of platelets in the 6D1 group. Transmission electron microscopy of cross-sections confirmed these observations. We conclude that the adhesion of the first platelet layer to an artificial surface requires GPIIb/IIIa. The data also suggest that GPIb is required for the development of the second layer in vertical platelet thrombus growth.

Adenosine Diphosphate↗
PubMed1991

Skeletal muscle density: effects of obesity and non-insulin-dependent diabetes mellitus.

Obesity is associated with increased lean mass but its effects on lean-tissue density are less clear. To examine the effects of obesity and non-insulin-dependent diabetes mellitus (NIDDM) on lean-tissue composition and density, cross-sectional computed tomography (CT) scans of the midthigh were obtained in 20 men of various weights. Obesity was associated with increases in thigh-adipose (r = 0.75) and lean-tissue volumes (r = 0.52) and with reduced density of lean tissue (r = -0.73). The increased lean tissue in obesity was due to a nonadipose tissue component with a density below the normal range of muscle, an effect compounded by NIDDM, whereas normal-density muscle volume was unchanged.

Adipose Tissue↗
PubMed1991

Vasospasm and platelet deposition in human arteries: effects of topical methylene blue.

Vasodilation of small blood vessels is controlled in part by the endothelium-derived relaxing factor (EDRF), which also inhibits platelet adhesion. Methylene blue (MB), which is occasionally applied directly to blood vessels during microsurgery to provide orientation and prevent torsion, is an irreversible inhibitor of the effects of endothelium-derived relaxing factor and may thereby augment both vasospasm and platelet responses. We have investigated the effects of the extravascular adventitial application of methylene blue on platelet deposition to human placental arteries (HPA) in the presence and absence of surgically induced vasospasm. A trend toward increased platelet deposition to human placental arteries was seen in each group but did not reach significance. The degree of platelet deposition to control human placental arteries suggests that the effects of methylene blue on platelet deposition may be dwarfed by the effects of surgical trauma and ischemia.

Administration, Topical↗
PubMed1991

A prospective analysis of inter-rater agreement between a physician and a physician's assistant in selecting QMR vocabulary terms.

We prospectively identified a cohort of 19 hospital inpatients to serve as a test set to determine the agreement between a physician and a physician's assistant in selecting and entering Quick Medical Reference (QMR) vocabulary terms for use in QMR case analysis mode. For positive findings, there was good agreement between data entered by the physician's assistant and data entered by the physician. Overall matches for positive findings were 0.66 concordance for the initial state, and 0.67 for the final state. Concordance for negative findings was substantially lower. The QMR generated differential diagnoses lists of the physician and physician's assistant were judged as similar in 14 (74%) of the 19 cases when QMR critique and assert functions were used.

Artificial Intelligence↗
PubMedDate not supplied

Inhibition of platelet retention on artificial microvascular grafts with monoclonal antibodies and a high-affinity peptide directed against platelet membrane glycoproteins.

Rapid occlusion of artificial microvascular grafts (AMGs; less than or equal to 2-mm diameter) by platelet-rich thrombi prevents the clinical use of AMGs in cardiac, vascular, and plastic surgery. Since present antiplatelet agents are unable to assure AMG patency, we have studied the role of specific platelet membrane-glycoprotein blockade on platelet retention by AMGs. In a customized in vitro perfusion chamber, retention on polytetrafluoroethylene (PTFE) AMGs (1.0-mm i.d.) of indium-111-labeled platelets in human whole blood was measured in the presence and absence of inhibitors. Specific blockade of platelet membrane glycoprotein (Gp) IIb/IIIa was achieved using monoclonal antibody 10E5 (10 micrograms/ml) and the peptide GRGDS (Gly-Arg-Gly-Asp-Ser, 0.75 mM). These inhibited 98% and 35%, respectively, of platelet retention under circumstances in which aspirin (7 mM) and dextran (4 mg/ml) inhibited 19% and 18%, respectively, of platelet retention. Nonspecific immunoglobulin G F(ab')2 (10 micrograms/ml) and nonspecific peptide (GGDA; Gly-Gly-Asp-Ala, 0.75 mM), used as control reagents, were ineffective in this setting. Monoclonal antibody 6D1 (10 micrograms/ml), which blocks platelet membrane GpIb, prevented 82% of platelet retention on PTFE. These doses of 10E5 and GRGDS completely inhibited platelet aggregation in response to 20 microM ADP, and the dose of 6D1 completely inhibited ristocetin-induced platelet agglutination. The aspirin dose prevented the second phase of ADP-induced aggregation. These data indicate that not only does initial platelet adhesion to PTFE require GpIIb/IIIa but also that GpIb plays a significant role in the early stages of platelet retention on PTFE AMGs.

Adenosine Diphosphate↗