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PubMed2006

Maternal IQ, child IQ, behavior, and achievement in urban 5-7 year olds.

In one study of children in 27 families with maternal retardation, those children with higher intelligence quotient (IQ) were more likely to have multiple behavior problems than those with lower IQ. If true, this result would affect clinical practice, but it has not been replicated. Because the setting of the initial observation is similar to the setting of childhood lead poisoning, we attempted a replication using data from the Treatment of Lead-Exposed Children (TLC) study, in which 780 children aged 12-33 mo with blood lead levels 20-44 microg/dL were randomized to either succimer treatment or placebo and then followed up to 5 y. Of 656 mothers of TLC children with IQ measured, 113 demonstrated mental retardation (IQ <70). Whether maternal IQ was <70 or >or=70, children with IQ >or=85 were rated more favorably on cognitive tests and behavioral questionnaires than children with IQ <85; these measures included Conners' Parent Rating Scale-Revised at age 5, the Developmental Neuropsychological Assessment at ages 5 and 7, and the Behavioral Assessment System for Children at age 7. Among children of mothers with IQ <70, those with IQ >or=85 did not show more severe clinical behavioral problems, nor were they more likely to show multiple behavior problems. Children with higher IQ have fewer behavior problems, irrespective of the mother's IQ. In the special setting of mothers with IQ <70, children with higher IQ are not at greater risk of behavior problems.

Achievement↗
PubMed2004

Reinforcement learning algorithms for robotic navigation in dynamic environments.

The purpose of this study was to examine improvements to reinforcement learning (RL) algorithms in order to successfully interact within dynamic environments. The scope of the research was that of RL algorithms as applied to robotic navigation. Proposed improvements include: addition of a forgetting mechanism, use of feature based state inputs, and hierarchical structuring of an RL agent. Simulations were performed to evaluate the individual merits and flaws of each proposal, to compare proposed methods to prior established methods, and to compare proposed methods to theoretically optimal solutions. Incorporation of a forgetting mechanism did considerably improve the learning times of RL agents in a dynamic environment. However, direct implementation of a feature-based RL agent did not result in any performance enhancements, as pure feature-based navigation results in a lack of positional awareness, and the inability of the agent to determine the location of the goal state. Inclusion of a hierarchical structure in an RL agent resulted in significantly improved performance, specifically when one layer of the hierarchy included a feature-based agent for obstacle avoidance, and a standard RL agent for global navigation. In summary, the inclusion of a forgetting mechanism, and the use of a hierarchically structured RL agent offer substantially increased performance when compared to traditional RL agents navigating in a dynamic environment.

Algorithms↗
PubMed2006

Rollover-free navigation for a mobile agent in an unstructured environment.

This paper introduces a navigation method for a teleoperated mobile agent (or robot) moving in an unstructured environment that includes unknown obstacles and uneven terrain, based on a guided-navigation algorithm (GNA) and a rollover-prevention algorithm (RPA). Although the mobile agent is primarily driven by an operator at a remote site, it reacts autonomously for avoiding collision with obstacles and for preventing rollover when it suspects/detects possible collision or rollover. The autonomous reactive motion is normally unexpected, thus there exists the inconsistency between the intended motion and the controlled motion of the agent from the operator. A force-reflection technique utilizing a force-feedback joystick is developed to manipulate this inconsistency. To verify the feasibility and effectiveness of the proposed navigation method, experiments with the Robot for Hazardous Application-Double Tracks (ROBHAZ-DT) (actual mobile agent) are successfully carried out.

Artificial Intelligence↗
PubMed2000

Embodiment of evolutionary computation in general agents.

Holland's Adaptation in Natural and Artificial Systems largely dealt with how systems, comprised of many self-interested entities, can and should adapt as a whole. This seminal book led to the last 25 years of work in genetic algorithms (GAs) and related forms of evolutionary computation (EC). In recent years, the expansion of the Internet, other telecommunications technologies, and other large scale networks have led to a world where large numbers of semi-autonomous software entities (i.e., agents) will be interacting in an open, universal system. This development cast the importance of Holland's legacy in a new light. This paper argues that Holland's fundamental arguments, and the years of developments that have followed, have a direct impact on systems of general network agents, regardless of whether they explicitly exploit EC. However, it also argues that the techniques and theories of EC cannot be directly transferred to the world of general agents (rather than EC-specific) without examination of effects that are embodied in general software agents. This paper introduces a framework for EC interchanges between general-purpose software agents. Preliminary results are shown that illustrate the EC effects of asynchronous actions of agents within this framework. Building on this framework, coevolutionary agents that interact in a simulated producer/consumer economy are introduced. Using these preliminary results as illustrations, areas for future investigation of embodied EC software agents are discussed.

Algorithms↗
PubMed2001

Intelligent use of NSAIDs--where do we stand?

Non-steroidal anti-inflammatory drugs (NSAIDs) are drugs commonly prescribed for a variety of medical conditions. They are potent pharmacological agents efficacious for inflammatory conditions, but have significant gastrointestinal (GI), renal and haematological toxicity that must not be taken lightly. The newer, more cyclooxygenase-(COX)-2-selective NSAIDs, have no effects on platelet function and little GI toxicity, but do have renal physiological effects. The superiority of one NSAID over another has not been clinically demonstrated in musculoskeletal conditions, nor has the efficacy of NSAIDs in non-inflammatory rheumatic conditions been shown to be better than that of simple analgesics. NSAIDs are indicated for primary therapy of inflammatory rheumatic diseases and the more selective COX-2 agents should be employed as first choice when economically feasible. NSAIDs should not be used indiscriminately for non-inflammatory osteoarthritis or musculoskeletal injuries, particularly in the elderly patient, in whom alternative, less toxic therapy should be sought.

Aged↗
PubMed1999

An electronic study form to support collaborating agents in the management of clinical knowledge.

When dealing with biological organisms, one has to take into account some peculiarities which significantly affect the representation of knowledge about them. These are complemented by the limitations in the representation of propositional knowledge, i.e. the majority of clinical knowledge, by artificial agents. Thus, the opportunities to automate the management of clinical knowledge are widely restricted to closed contexts and to procedural knowledge. Therefore, in dynamic and complex real-world settings such as health care provision to HIV-infected patients human and artificial agents must collaborate in order to optimize the time/quality antinomy of services provided. If applied to the implementation level, the overall requirement ensues that the language used to model clinical contexts should be both human- and machine-interpretable. The eXtensible Markup Language (XML), which is used to develop an electronic study form, is evaluated against this requirement, and its contribution to collaboration of human and artificial agents in the management of clinical knowledge is analyzed.

Artificial Intelligence↗
PubMed1994

Speech abnormalities in tardive dyskinesia.

The authors assessed tardive dyskinesia and the structure and physiology of speech apparatus, phonation, and articulation speech abnormalities in 27 chronically ill male psychiatric patients. Tardive dyskinesia was associated with impairment in phonation, intelligibility, and rate of speech production. Patients with and without tardive dyskinesia had similar rates of structural and physiological abnormalities of speech apparatus. The authors conclude that tardive dyskinesia is associated with substantial impairment in speech.

Antipsychotic Agents↗
PubMed2003

Predicting intellectual outcome among children treated with 35-40 Gy craniospinal irradiation for medulloblastoma.

Fifty children diagnosed with medulloblastoma completed 188 psychological evaluations using the Wechsler Intelligence Scales for Children (D. Wechsler, 1974, 1991) over a 7-year study period following 35-40 Gy postoperative craniospinal irradiation. Random coefficient models were used to predict the trend in the children's intellectual performance as a function of time since diagnosis, with both patient and treatment variables as parameters of this function. A quadratic model demonstrated a delay prior to decline in performance for older patients, whereas the younger patients showed an immediate loss of performance with a plateau at approximately 6 years postdiagnosis. A steeper decline was found for those with higher baseline performance. Clinicians may use the proposed predictive model to identify those patients who are at risk of significant intellectual decline.

Adolescent↗
PubMed1983

Late effects of treatment on the intelligence of children with posterior fossa tumors.

This retrospective pilot study was undertaken to evaluate the late effects of treatment on intelligence in a population of children with posterior fossa tumors. Ten children with posterior fossa tumors treated with radiation and chemotherapy received intellectual evaluations at least one year following diagnosis. Six children had medulloblastomas, one child had a fourth ventricular ependymoma, two children had brainstem gliomas, and one child had a recurrent cerebellar astrocytoma. Children with supratentorial tumors were specifically excluded from the study in order to eliminate the possible influence of the tumor on intellectual functioning. Four children had had intelligence testing in school prior to treatment of their tumor. In each case results following treatment revealed a deterioration of full scale IQ of at least 25 points. Six children did not have prior testing; of these, two had IQ's less than 20. Overall, 50% of the patients had IQ's of less than 80 and 20% had IQ's of greater than 100. Furthermore, four children with normal intelligence (IQ greater than 80) have learning problems requiring special classes. Thus, of the ten children evaluated, all have either dementia, learning disabilities, or evidence of intellectual retardation. This study suggests that aggressive treatment of children with brain tumors may improve survivals but may be associated with significant long-term disabilities.

Adolescent↗
PubMed1999

Behavioural parameters in hypertensives on atenolol therapy.

Behavioural responses which included psychological tests and cold pressor test as a stress test were studied in 20 mild to moderate hypertensives of both sexes, excluding smokers, alcoholics, secondary hypertensives and patients of chronic obstructive pulmonary diseases. Subjects were put on 2 weeks of placebo washout period followed by 6 weeks of treatment with atenolol. Following treatment with atenolol they showed no significant alteration in the scores of psychological tests which included Weschler adult intelligence scale for orientation, while showing significant depression in the rise of heart rate, systolic blood pressure and diastolic blood pressure following cold pressor test. On further analysis, the results showed that hypertensives on placebo had lower scores of memory and attention test as compared to normotensive controls. Besides this, hypertensives on placebo had higher rise of heart rate and systolic blood pressure as compared to normotensive controls after cold pressor test.

Adrenergic beta-Antagonists↗
PubMed2007

Efficacy of cognitive rehabilitation in patients with mild cognitive impairment treated with cholinesterase inhibitors.

BACKGROUND: Individuals who have Mild Cognitive Impairment (MCI) may be in a transitional stage between aging and Alzheimer's disease (AD). The high rate of conversion from MCI to AD makes early treatment an important clinical issue. Recent evidence suggests that cognitive training intervention may reduce the rate of progression to AD. OBJECTIVES: To evaluate the efficacy of a NeuroPsychological Training (TNP) in patients with MCI who are treated with cholinesterase inhibitors (ChEIs), compared with patients MCI treated only with ChEIs and patients not treated, in a longitudinal, one year follow-up study. METHODS: One year longitudinal and retrospective comparison study of neuropsychological performances in 59 subjects affected by Mild Cognitive Impairment (MCI) according to Petersen's criteria. Fifteen subjects were randomised to receive TNP plus cholinesterase inhibitors; 22 subjects cholinesterase inhibitors alone and 22 subjects no treatment. All the subjects referring memory complaints, corroborated by an informant, underwent a multidimensional assessment concerning neuropsychological, behavioural and functional characteristics, at baseline and after one year follow-up. RESULTS: Subjects without treatment maintained their cognitive, functional and behavioural status after one year; patients treated only with ChEIs improved in depressive symptoms whereas subjects treated with TNP and ChEIs showed significant improvements in different cognitive areas, such as memory, abstract reasoning and in behavioural disturbances, particularly depressive symptoms. CONCLUSIONS: A long-term TNP in ChEIs-treated MCI subjects induces additional cognitive and mood benefits.

Activities of Daily Living↗
PubMed1987

Issues in the pharmacologic management of primary hypertension in adolescence.

Hypertension may occur in as many as 12% of adolescents and is usually of primary origin. There is an age-related increase of the blood pressure, making it difficult to define the limits of normal. True hypertension can be defined as blood pressure exceeding 140/90 mmHg regardless of age. Borderline blood pressure is said to exist when the blood pressure is above the 90th percentile for age. Blood pressure can be lowered with a wide variety of drugs, and adolescents are most often prescribed adult doses. There are specific concerns about the drugs' side effects in adolescents, particularly effects on growth and development, cognitive function, and metabolism. Diuretics are not the best first choice for therapy because of their metabolic effects. Cardiac hypertrophy and the morbidity of sustained hypertension are reduced by sympathetic inhibitors. Beta-blockers are the best currently available choice, although newer alpha-blocking agents may have some advantages. Even borderline pressure has been associated with evidence of cardiac hypertrophy, and there is substantial evidence that the adolescents with the highest blood pressures, even if still within normal limits, have the highest likelihood of developing sustained hypertension as adults. Yet there is no data establishing a beneficial effect on long-term risk of early treatment with drugs. For these reasons, nonpharmacologic intervention and close follow up are preferred as treatment for borderline blood pressure.

Adolescent↗
PubMed2006

Serial contrast-enhanced MRI of the pancreas: correlation with secretin-stimulated endoscopic pancreatic function test.

RATIONALE AND OBJECTIVES: The purpose of this study was to determine the relationship between the pancreatic enhancement on serial contrast-enhanced MRI (CEMRI) and pancreatic exocrine function using the secretin-stimulated endoscopic pancreatic function test (ePFT). MATERIALS AND METHODS: A total of 30 patients with clinical symptoms consistent with chronic pancreatitis underwent CEMRI of the abdomen and ePFT within a 1- to 4-week interval. CEMRI was performed in arterial, early venous, and late venous phases. Secretin ePFT was performed with the measurement of HCO(3) concentration from the duodenal aspirates after secretin stimulation. Contrast enhancement ratio of the arterial phase to early venous phase was measured on CEMRI (SIRa/SIRv). A three-point evaluation system was used for grading the HCO(3) concentration and the enhancement ratio on MRI. For the significance of correlation, kappa statistics was used. Sensitivity and specificity of CEMRI was determined for the diagnosis of early chronic pancreatitis accepting ePFT as a reference. RESULTS: Twenty patients had identical scores on both secretin ePFT and CEMRI. Ten patients revealed discrepancy in scores. Kappa statistics revealed moderate agreement between MRI and ePFT (kappa = 0.44). Sensitivity and specificity values for the diagnosis of pancreatitis were 82% and 57%, respectively. Positive predictive value was 56%, and negative predictive value was 86%. CONCLUSION: The results of our data indicate that serial CEMRI is an appropriate imaging technique to rule out early chronic pancreatitis. However, secretin-stimulated imaging or ePFT may still be needed for the definite diagnosis of pancreatic exocrine dysfunction.

Adult↗
PubMed2000

Transient seizure remission in intractable localization-related epilepsy.

We sought to elucidate the clinical features of transient seizure remission in intractable cryptogenic or symptomatic localization-related epilepsy of childhood onset. Transient seizure remission has been reported to occur in mesial temporal sclerosis or focal cortical dysplasia, but few reports have focused on this phenomenon. We retrospectively scrutinized the temporal profiles of seizure frequency of 99 patients with intractable localization-related epilepsy by reviewing their medical charts. Ten patients (10%) had transient seizure remissions that lasted for 2 years or longer. When an appropriate antiepileptic agent was administered, seizure remission occurred within 1-18 months. Without any triggering factors, the seizures recurred abruptly in seven patients and gradually in three. Epileptiform discharges on electroencephalography disappeared during the transient remission in seven patients and reappeared in five of them after recurrence. After recurrence, no antiepileptic agent was able to control the seizures. In comparison with those without transient seizure remission, these 10 patients tended to have normal intelligence and a positive family history for epilepsy. Transient seizure remission occurs in a variety of pathologic changes and may be a result of an interaction between the progressive nature of some types of epileptogenic foci and an effect of the antiepileptic drugs.

Adolescent↗
PubMed2002

The potential economic consequences of cognitive improvement with losartan.

In a clinical trial, treatment of mild-moderate hypertensive patients with losartan (50 mg) increased Mini-Mental State Examination (MMSE) scores by 4 points from baseline over a 26-month period, compared with a 1-point increase in patients treated with hydrochlorothiazide (25 mg). This study explores the potential economic consequences of this improvement in cognitive function in a population of elderly hypertensive patients in Sweden. Resource use and MMSE data for 437 hypertensive, non-demented subjects aged 75 years and above, were taken from a population-based study in Sweden. MMSE scores were strongly related with costs of care due to higher utilization of home help and special living arrangements in patients with low scores. A 1-point difference in MMSE was associated with a difference in the annual cost of care of approximately 5700 Swedish kronor (SEK). Over 26 months, the potential cost savings from the 4-point improvement observed with losartan was estimated to be between 24700 and 43700 SEK. This can be compared with the acquisition cost of losartan; approximately 5700 SEK over the study period. Thus, an improvement in cognitive function of the magnitude documented in the study of losartan vs hydrochlorothiazide, may translate into economic benefits beyond those expected in terms of blood pressure control.

Adult↗
PubMed2006

Elevated childhood serotonergic function protects against adolescent aggression in disruptive boys.

OBJECTIVE: This longitudinal study examined whether responsiveness of the neurotransmitter serotonin (5-HT) in childhood predicts adolescent aggression. METHOD: Boys (N = 33) with disruptive behavior disorders who received assessments of central 5-HT function via the prolactin response to fenfluramine between 1990 and 1994 when they were 7 to 11 years old were re-evaluated clinically on average 6.7 years later. RESULTS: After accounting for baseline aggression, early 5-HT function accounted for a significant proportion of variance in adolescent aggression. This prospective relationship of childhood 5-HT function with adolescent aggression (r = -0.71) and antisocial behavior (r = -0.59) was found primarily in adolescents who were aggressive during childhood. Irrespective of childhood aggression, no child with high 5-HT function was particularly aggressive at follow-up. CONCLUSIONS: Low childhood 5-HT function appears important, but not sufficient, for the emergence of adolescent aggression. However, early high 5-HT function may protect against adolescent violence and aggression.

Adolescent↗
PubMed1986

A critical appraisal of recent drug research in mental retardation: the Coldwater studies.

This paper attempts to assess public and professional attitudes toward drug treatment in mental retardation and concludes that considerable sentiment has developed in recent years against the use of pharmacotherapy. A number of factors contributing to this prevailing attitude were identified and discussed. In particular, a series of investigations carried out by researchers at the Coldwater Regional Center for Developmental Disabilities (Michigan), which have had negative implications for drug treatment, were summarized. These studies have suggested that psychotropic drugs, especially the antipsychotics, may adversely affect clinical management of mentally retarded persons, depress learning performance, and interfere with the efficacy of reinforcement contingencies. However, certain features of these studies, such as the procedures for selecting subjects, the doses utilized and overall guiding philosophy, appear to limit their relevance. Balanced against these are a number of other investigations showing circumscribed positive clinical effects, a lack of interference with learning and little or no disruption of reinforcement contingencies. It was concluded that all-encompassing judgments about the value of pharmacotherapy in mentally retarded people are premature at this time. We suggested that a major objective of clinical drug research should be to look for enhancement of adaptive functioning by discovering appropriate subject-treatment combinations, while remaining vigilant for adverse effects.

Aggression↗