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Biomedical subjects

D Geller

Publications and source records attributed to D Geller.

At least 19 recordsLinked to original sources
PubMed2001

Impact of tic disorders on ADHD outcome across the life cycle: findings from a large group of adults with and without ADHD.

OBJECTIVE: The impact of tic disorders on the outcome of attention deficit hyperactivity disorder (ADHD) remains a subject of high scientific and clinical interest. To evaluate the impact of comorbid ADHD and tic disorders from a lifespan perspective, the authors systematically examined data from adults with and without ADHD. METHOD: They comprehensively evaluated 312 consecutively referred adults with ADHD and 252 comparison subjects without ADHD. Tic disorders were characterized along with a wide range of neuropsychiatric correlates, including other comorbid disorders as well as indexes of function in the domains of school, cognition, and interpersonal functioning. RESULTS: A significantly greater proportion of adults with ADHD (12%) than those without ADHD (4%) had tic disorders. Tic disorders followed a mostly remitting course and had little impact on functional capacities. In addition, tic disorders were not associated with stimulant use. CONCLUSIONS: These findings in adults with ADHD confirm and extend previous findings in young subjects with ADHD, documenting that although individuals with ADHD are at greater risk for tic disorders, the presence of tic disorders has a limited impact on ADHD outcome.

Adolescent↗
PubMed2001

Plastic bottles as spacers for a pressurized metered-dose inhaler: in vitro characteristics.

Homemade spacer devices are commonly used by children with asthma to improve aerosol deposition from pressurized metered dose inhalers (pMDI); however, the efficacy and efficiency of these devices are not fully characterized. We determined the quality of fine particle fraction (< 4.7 microns) and ultrafine particle fraction (< 3.3 microns) of three bottles (from 280 ml to 500 ml) commonly used as spacers in Trinidad and Tobago and compared their performance to the commercially available valved holding chamber (OpT) and pMDI. These data were obtained in vitro using a cascade impactor. All 3 bottles and the OpT were similar (p > 0.05) in reducing the amount of albuterol emitted as large particles (> 4.7 microns) to less than 10 micrograms. The different sized bottles (from 280 ml to 500 ml) produced identical quantities of albuterol in the fine particle and ultrafine particle ranges (p > 0.05). All of the sample bottle spacers emitted a higher amount (p < 0.002) of fine and ultrafine particles than the OpT and pMDI alone. The OpT resulted in a significantly higher fraction of fine particles (p < 0.05) and a greater quantity of drug (p < 0.05) in the ultrafine range as compared to the MDI only. The sizes of particles obtained from the bottle spacers are those that have a high probability of reaching the lower airway; however, the clinical relevance of these findings remains to be determined.

Asthma↗
PubMed2000

Clinical correlates of obsessive compulsive disorder in children and adolescents referred to specialized and non-specialized clinical settings.

The objective of this study was to assess the extent of referral bias by comparing children and adolescents with Obsessive Compulsive Disorder (OCD) ascertained through a specialized pediatric OCD and a general child psychiatry clinic. Subjects were juveniles meeting DSM-III-R and DSM IV criteria for OCD referred to a general pediatric psychopharmacology clinic and to a specialized OCD clinic within the same academic medical center. Subjects were evaluated clinically and with structured diagnostic interviews using the Kiddie SADS-E. OCD was identified in 8.6% of the general psychiatry clinic subjects. The only differences between ascertainment sources in clinical or sociodemographic characteristics of OCD subjects were higher rates of social phobia and ADHD in the non-specialized clinic, while specialty clinic subjects had a greater lifetime severity of OCD and were more likely to have received treatment of their OCD. Because we found limited evidence for referral biases, our results suggest that findings from studies using either of these sources may generalize to the other. It also suggests that pooling subjects from the two sources is justified. Nevertheless, because some group differences did emerge, researchers should acknowledge referral bias as a potential limitation of their work.

Adolescent↗
PubMed2000

Long-term survival after liver transplantation in 4,000 consecutive patients at a single center.

OBJECTIVE: To evaluate the long-term survival outcomes of a large cohort of liver transplant recipients and to identify static and changing factors that influenced these outcomes over time. SUMMARY BACKGROUND DATA: Liver transplantation has been accepted as a therapeutic option for patients with end-stage liver disease since 1983, with continual improvements in patient survival as a result of advances in immunosuppression and medical management, technical achievements, and improvements in procurement and preservation. Although many reports, including registry data, have delineated short-term factors that influence survival, few reports have examined factors that affect long-term survival after liver transplantation. METHODS: Four thousand consecutive patients who underwent liver transplantation between February 1981 and April 1998 were included in this analysis and were followed up to March 2000. The effect of donor and recipient age at the time of transplantation, recipient gender, diagnosis, and year of transplantation were compared. Rates of retransplantation, causes of retransplantation, and cause of death were also examined. RESULTS: The overall patient survival for the entire cohort was 59%; the actuarial 18-year survival was 48%. Patient survival was significantly better in children, in female recipients, and in patients who received transplants after 1990. The rates of retransplantation for acute or chronic rejection were significantly lower with tacrolimus-based immunosuppression. The risk of graft failure and death was relatively stable after the first year, with recurrence of disease, malignancies, and age-related complications being the major factors for loss. CONCLUSION: Significantly improved patient and graft survival has been observed over time, and graft loss from acute or chronic rejection has emerged as a rarity. Age-related and disease-related causes of graft loss represent the greatest threat to long-term survival.

Adolescent↗
PubMed1999

Multicenter open-label sertraline study in adolescent outpatients with major depression.

OBJECTIVE: The aim of this multicenter outpatient study was to assess the therapeutic benefits, response patterns, and safety of sertraline in adolescent major depressive disorder (MDD). METHOD: Fifty-three adolescent outpatients with MDD were treated in an open-label, 10-week, acute-phase trial with sertraline and, if responders, for an additional 12-week continuation phase. Diagnostic and response assessments included the Schedule for Affective Disorders and Schizophrenia for School-Age Children (K-SADS), 17-item K-SADS-derived depression severity score, Hamilton Depression Rating Scale, Beck Depression Inventory, and Clinical Global Impression Scale. RESULTS: By 2 weeks, when analyzed as continuous variables, all severity scores showed significant differences from baseline. This pattern persisted through 10 weeks, with a significantly greater response occurring when treatment was extended from 6 to 10 weeks. Both clinician- and patient-rated improvement was maintained during continuation treatment. Response rates varied considerably when depression rating scales were analyzed categorically. Sertraline was generally well tolerated and did not induce manic symptoms. CONCLUSIONS: In open treatment of adolescent MDD with sertraline, significant improvement occurred early on and was maintained for 22 weeks. Absolute response rates varied depending on the rating scales used, definition of response, and length of treatment. Maximal response rates were obtained by clinician-defined ratings after 10 weeks of treatment.

Adolescent↗
PubMed1999

Absence of cardiovascular adverse effects of sertraline in children and adolescents.

OBJECTIVE: In a 12 week, placebo-controlled, parallel-design, multicenter study of sertraline for obsessive-compulsive disorder in 107 children and 80 adolescents, the authors prospectively assessed cardiovascular effects to doses of sertraline of < or = 200 mg/day. METHOD: Vital signs (blood pressure and heart rate) and electrocardiograph parameters (ECGs) were systematically evaluated at baseline and again throughout treatment. RESULTS: There were no clinically significant cardiovascular adverse events in any of the subjects enrolled in the study. Moreover, compared with baseline and placebo, sertraline treatment at an average dose of 167 mg did not result in any clinically meaningful changes in any ECG indices (PR, QRS, and QTc intervals), cardiac rhythm, blood pressure, or heart rate. CONCLUSIONS: These prospectively derived results support the cardiovascular safety of sertraline at doses up to 200 mg in children and adolescents.

Adolescent↗
PubMed1998

Is juvenile obsessive-compulsive disorder a developmental subtype of the disorder? A review of the pediatric literature.

OBJECTIVE: To examine the clinical correlates of obsessive-compulsive disorder (OCD) in children and adolescents. METHOD: A systematic review of the extant literature on juvenile OCD was conducted examining age at onset, gender distribution, symptom phenomenology, psychiatric comorbidity, neurological and perinatal history, family psychiatric history, cognitive and neuropsychological profiles, and treatment and outcome in juvenile OCD subjects. RESULTS: Juvenile OCD was associated with a unique peak of age at onset indicating a bimodal incidence of the disorder, male preponderance, a distinct pattern of comorbidity with attention-deficit/hyperactivity disorder and other developmental disorders as well as frequent associated neuropsychological deficits, an increased familial loading for OCD, and frequent absence of insight. CONCLUSION: These findings show that juvenile OCD is associated with a unique set of correlates that appear to differ from findings reported in studies of adult OCD subjects. Although in need of confirmation, these findings suggest that juvenile OCD may be a developmental subtype of the disorder. Since juvenile OCD is likely to continue into adulthood, these findings stress the importance of considering age at onset in clinical and research studies of adults with OCD.

Adolescent↗
PubMed1998

Disentangling the overlap between Tourette's disorder and ADHD.

OBJECTIVE: To identify similarities and differences in neuropsychiatric correlates in children with Tourette's syndrome (TS) and those with ADHD. METHOD: The sample consisted of children with Tourette's syndrome with ADHD (N = 79), children with Tourette's syndrome without ADHD (N = 18), children with ADHD (N = 563), psychiatrically referred children (N = 212), and healthy controls (N = 140). RESULTS: Disorders specifically associated with Tourette's syndrome were obsessive compulsive disorder (OCD) and simple phobias. Rates of other disorders, including other disruptive behavioral, mood, and anxiety disorders, neuropsychologic correlates, and social and school functioning were indistinguishable in children with Tourette's and ADHD. However, children with Tourette's syndrome plus ADHD had more additional comorbid disorders overall and lower psychosocial function than children with ADHD. CONCLUSIONS: These findings confirm previously noted associations between Tourette's syndrome and OCD but suggest that disruptive behavioral, mood, and anxiety disorders as well as cognitive dysfunctions may be accounted for by comorbidity with ADHD. However, Tourette's syndrome plus ADHD appears to be a more severe condition than ADHD alone.

Adolescent↗
PubMed1996

Comparative topology studies in Saccharomyces cerevisiae and in Escherichia coli. The N-terminal half of the yeast ABC protein Ste6.

Gene fusions have provided a strategy for determining the topology of polytopic membrane proteins in Escherichia coli. To evaluate whether this highly effective approach is applicable to heterologously expressed eukaryotic integral membrane proteins, we have carried out a comparative topological study of the eukaryotic membrane protein Ste6 both in bacteria and in yeast. Ste6, is an ATP binding cassette (ABC) protein, essential for export of the a-factor mating pheromone in Saccharomyces cerevisiae. The topogenic reporters, invertase in S. cerevisiae and alkaline phosphatase in E. coli, were fused to Ste6 at identical sites and the fusions were expressed in yeast and bacteria, respectively. The results obtained in both systems are similar, although more definitive in E. coli, and support the predicted six-transmembrane spans organization of the N-terminal half of Ste6. Thus, the topological determinants for membrane insertion of polytopic proteins in prokaryotic and in eukaryotic systems appear to be highly similar. In this study we also demonstrate that Ste6 does not contain a cleaved signal sequence.

ATP-Binding Cassette Transporters↗
PubMed1996

Effect of aminoguanidine and cyclosporine on lung allograft rejection.

BACKGROUND: Aminoguanidine, a nitric oxide synthase inhibitor, has been shown to reduce the inflammatory allogeneic response. Here we used it in combination with cyclosporine to evaluate its effect on a clinically relevant immunosuppressive protocol. METHODS: Orthotopic left lung transplantation was performed in 120 rats, of which 24 were syngeneic Lewis to Lewis controls, and allogeneic transplantations were performed across major histoincompatibility barriers (ACI to Lewis). We studied synchronous histologic changes accompanying cytokines and nitric oxide synthase messenger RNA by reverse transcriptase polymerase chain reaction in the grafted lungs. Nitrate/nitrite, oxidized degradation products of nitric oxide, were measured in the whole blood, as were concentrations of cyclosporine. Lung tissue was immunohistochemically stained for nitric oxide synthase protein. Rats receiving allografts were either untreated (24) or received low-dose cyclosporine (232 +/- 105 ng/mL blood by high-performance liquid chromatography), high-dose cyclosporine (2,046 +/- 664 ng/mL), aminoguanidine alone (800 mg. kg-1. day-1 intraperitoneally), or aminoguanidine plus low-dose cyclosporine. RESULTS: The results suggest that aminoguanidine combined with low doses of cyclosporine can reduce the allogeneic response across major histoincompatibilities in rodent lung transplantation. Its biologic effect may not exclusively depend on the inhibition of nitric oxide synthase and may, by other means, reduce proinflammatory cytokines. CONCLUSIONS: Aminoguanidine may be an effective adjuvant to conventional immunosuppression.

Animals↗
PubMed1996

Six-week, double-blind, placebo-controlled study of desipramine for adult attention deficit hyperactivity disorder.

OBJECTIVE: Despite the increasing awareness of attention deficit hyperactivity disorder (ADHD) in adults, there are a limited number of controlled pharmacologic studies of this disorder; most of the trials have focused on the psychostimulants. Because the tricyclic anti-depressant desipramine has been found to be effective in treating ADHD in pediatric groups, the authors tested its efficacy in adults with ADHD. METHOD: The authors conducted a randomized, 6-week, placebo-controlled, parallel-design study of desipramine at a target daily dose of 200 mg in 41 adult patients with DSM-III-R ADHD. They used standardized structured psychiatric instruments for diagnosis and, as the dependent variables (outcome), used separate assessments of ADHD, depressive, and anxiety symptoms at baseline and at each biweekly visit. RESULTS: There were highly significant differences in the reduction of ADHD symptoms between adults receiving desipramine and placebo. Within the desipramine-treated group, there were clinically and statistically significant differences between baseline and the week 6 end point for 1) reduction of 12 of 14 symptoms of ADHD and 2) decreases in the broad categories of hyperactivity, impulsivity, and inattentiveness. In contrast, placebo-treated patients showed no differences between baseline and end point for any of the ADHD symptoms assessed. According to strict, predefined criteria for response, 68% of desipramine-treated subjects and no subjects in the placebo group were considered positive responders. Response to desipramine was independent of dose, level of impairment, gender, or lifetime psychiatric comorbidity with anxiety or depressive disorders. CONCLUSIONS: These results, similar to findings in children and adolescents with ADHD, indicate that desipramine is effective in the treatment of ADHD in adults.

Adolescent↗
PubMed1995

Regulation of inducible nitric oxide production by intracellular calcium.

BACKGROUND: Because increased nitric oxide (NO) production during sepsis can be detrimental to the host, inhibition of NO synthesis by various antagonists has been proposed as a therapeutic option. However, none of these approaches has addressed the possible regulation of inducible NO synthesis (iNOS) by endogenous intracellular signaling mechanisms. The purpose of our study was to determine whether intracellular calcium ([Ca2+]i) regulates iNOS. METHODS: The macrophage cell line RAW 264.7 cells stimulated to produce NO were cultured in the presence or absence of the calcium ionophore A23187, ionomycin, or the Ca(2+)-adenosine triphosphatase inhibitor thapsigargin. Supernatants and total cellular RNA were recovered for measurement of iNOS messenger RNA (Northern blot) and NO2- (stable end product of NO), respectively. Simultaneous measurement of [Ca2+]i was performed by fluorescence spectrophotometry. RESULTS: The calcium ionophore A23187, ionomycin, and thapsigargin all produced a dose-dependent inhibition of NO end product and iNOS messenger RNA (confirmed by densitometry) with a simultaneous increase in [Ca2+]i, confirmed by fluorescence spectrophotometry. This could not be reversed by exogenous L-arginine and was not observed if these agents were added beyond 0 hours of culture. CONCLUSIONS: Although iNOS is traditionally viewed as calcium independent, these data clearly show that [Ca2+]i regulates iNOS messenger RNA induction and end product synthesis. Endogenous cellular second messenger may thus be important in autoregulation of NO synthesis. Alternatives to pharmacologic or antagonist inhibition of NO deserve further investigation.

Arginine↗
PubMed1995

TGF-beta regulates production of NO in pulmonary artery smooth muscle cells by inhibiting expression of NOS.

We have previously reported that a mixture of lipopolysaccharide and cytokines stimulates cultured rat pulmonary artery smooth muscle cells (RPASM) to express elevated levels of mRNA for inducible nitric oxide synthase (iNOS), and to produce large amounts of nitric oxide (NO). The current study tests the hypothesis that transforming growth factor-beta (TGF-beta) modulates this process. Accordingly, RPASM were treated with a mixture of LPS (10 micrograms/ml) and the cytokines interleukin-1 beta (5 U/ml), tumor necrosis factor-alpha (500 U/ml), and interferon-gamma (100 U/ml). In the absence of TGF-beta 1, NO production (indicated by colorimetric assay of cumulative nitrite levels at 24 h) was greatly increased, as previously observed. Under identical conditions, TGF-beta 1 caused a concentration-dependent decrease in NO production. The addition of neither excess L-arginine nor sepiapterin reversed the inhibition, indicating that the effect of TGF-beta 1 was not due to limitation of enzyme substrate or cofactor tetrahydrobiopterin, respectively. Northern and Western analyses showed that TGF-beta 1 reduced levels of iNOS mRNA and protein to baseline at all time points examined up to 24 h. Complete suppression of iNOS protein expression was evident even when TGF-beta 1 was added at postinduction time points. One mechanism of action of TGF-beta 1 was demonstrated in experiments in which degradation of iNOS protein was greatly increased by the addition of TGF-beta 1. These results demonstrate that TGF-beta 1 regulates production of NO in RPASM by inhibiting iNOS expression in part by increasing degradation of existing iNOS protein.

Amino Acid Oxidoreductases↗
PubMed1995

The effect of nedocromil sodium on childhood asthma during the viral season.

Viral-induced symptomatic respiratory infections (SRI) frequently cause exacerbations of asthma in children. This study investigated the protective effects of 0.5% nedocromil sodium nebulizer solution given three times a day in preventing asthma exacerbations associated with SRI. Ninety-three mild-moderate asthmatic children (6 to 12 yr of age) received either 0.5% nedocromil sodium or placebo for 24 wk during the viral season. The nedocromil sodium group was symptom-free 58% of the days, and the placebo-treated patients were symptom-free 45% of the days (p = 0.027). During Weeks 1-12, significant differences favored nedocromil sodium for asthma summary score (means: nedocromil sodium = 0.61, placebo = 0.92; p = 0.026), and daytime asthma (nedocromil sodium = 0.78, placebo = 1.22; p = 0.03). Significant differences were noted during monthly intervals for cough (Weeks 1-4: nedocromil sodium = 0.61, placebo = 0.92, p = 0.027) and peak expiratory flow rate (PEFR) (nedocromil sodium 262, placebo = 254 L/min, p = 0.041 Weeks 9-12). Patients in the active treatment group reduced their need for rescue inhaled beta 2-agonist by 10%, whereas patients treated with placebo demonstrated a 24% increase. There was a strong correlation between asthma symptoms and SRI symptoms (r = 0.47; p < 0.001). During SRIs, patients in the nedocromil sodium group demonstrated more rapid resolution of asthma symptoms immediately following infection (p = 0.033 summary score, p = 0.039 sleep difficulty). No serious adverse events were noted. Nedocromil sodium did not prevent the infection or exacerbation of asthma symptoms during SRI.(ABSTRACT TRUNCATED AT 250 WORDS)

Anti-Asthmatic Agents↗
PubMed1990

Reversal of the behavioral and electrophysiological abnormalities of an animal model of hepatic encephalopathy by benzodiazepine receptor ligands.

Behavioral and electrophysiological evidence implicating the GABA-benzodiazepine receptor complex in the pathogenesis of hepatic encephalopathy was obtained using an improved rat model of hepatic encephalopathy caused by thioacetamide-induced fulminant hepatic failure. After the administration of thioacetamide together with supportive therapy, acute hepatocellular failure developed in rats as a result of massive hepatocellular necrosis without evidence of renal failure or hypoglycemia. The evolution of hepatic encephalopathy in this model was sufficiently slow to readily permit the staging of the syndrome. Prominent features of the encephalopathy include a marked reduction in open field activity and an abnormal visual evoked response. Both the deficits in spontaneous motor function and visual evoked response abnormalities of rats in stages III to IV hepatic encephalopathy were significantly improved after the administration of the benzodiazepine receptor ligands flumazenil or Ro 15-4513. Doses of flumazenil or Ro 15-4513 that produced these effects in rats with hepatic encephalopathy had no detectable action on either the behavior or the visual evoked responses of normal rats. The ability of benzodiazepine receptor ligands to ameliorate both the behavioral depression and the visual evoked response abnormalities associated with hepatic encephalopathy in the thioacetamide-induced rat model suggest an involvement of the GABA/benzodiazepine receptor complex in the pathogenesis of hepatic encephalopathy. In addition, the similarity of these observations to those in rabbits with hepatic encephalopathy caused by galactosamine-induced fulminant hepatic failure is compatible with the hypothesis that the mechanisms of hepatic encephalopathy in these two distinct models share a common final pathway, the allosteric enhancement of GABAergic tone through the benzodiazepine receptor.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗