PubMed Health⌕ Search

Biomedical subjects

T Spencer

Publications and source records attributed to T Spencer.

At least 19 recordsLinked to original sources
PubMed1997

Juvenile mood disorders and office psychopharmacology.

Mood disorders afflict pediatric patients, cause significant impairment, and interfere with normal development. Increasingly, pediatricians are called on to assess and collaborate with mental health practitioners in medicating children and adolescents with mood disorders. Approaching the juvenile with a primary emphasis on clarifying the diagnoses, determining environmental antecedents and sequelae, and investigating suicide risk enables the pediatrician to institute appropriate treatment. Despite limited data from controlled studies, psychotherapy often is used for mild to moderate depression. Pharmacotherapy is indicated in cases unresponsive to psychotherapy and in severe or suicidal cases. First-line pharmacotherapy for depressed adolescents is usually an SRI followed by the atypical or TCA antidepressants. Bipolar disorder typically requires an aggressive medication regimen, including anticonvulsants, lithium, or a combination, as well as environmental modifications. With severe, difficult, or refractory cases, mental health consultation is recommended to clarify diagnoses and to provide psychotherapy and medication input.

Adolescent↗
PubMed1997

A study of the quantitative and qualitative impact of catheter shaft angulation in a mechanical intravascular ultrasound system.

Nonuniform rotation of mechanical intravascular ultrasound transducers may give rise to a geometric distortion of the ultrasound image known as the rotation angle artefact. This investigation studied the influence of different degrees and combinations of catheter shaft angulation on image morphology and the quantitative impact of the artefact using a circular perspex phantom and 3.5 F, 30 MHz Boston Scientific "Sonicath" catheters connected to a Hewlett Packard Sonos intravascular scanner. Major and minor diameters, cross-sectional area and circumference of the phantom lumen were measured and a "distortion index" calculated. Visually apparent geometric distortion was graded from 1 (absent) to 4 (severe). As expected, eccentric transducer location was associated much more frequently with identifiable distortion (70%) than was a concentric location (6%). Greater distortion occurred with increasing degrees of catheter shaft angulation, and was more pronounced in images from older catheters. The lumen area measurements in images in which no artefact was identified were accurate to within +/- 10% in 97% of cases, compared to only 81% of cases when an artefact was noted. The quantitative accuracy of an image in which geometric distortion is identified is thus not reliable. The direction of the quantitative error cannot be confidently predicted in any given case, although the mean lumen area tends to increase as the grade of distortion increases.

Artifacts↗
PubMed1997

Characterisation of atherosclerotic plaque by spectral analysis of intravascular ultrasound: an in vitro methodology.

Raw 30-MHz intravascular ultrasound data have been captured from postmortem coronary arteries (n = 4) to develop radio frequency analysis techniques for the characterisation of atherosclerotic plaque. Digitised data acquired from positions (n = 8) within diseased sections of artery were compared with the corresponding histology and radiology. Scan-converted images were used to locate regions of interest (ROI = 33) within areas of tissue composition: loose fibrotic tissue (LFT), dense fibrotic tissue (DFT) and calcium (CA). A range of parameters was extracted from the normalised power spectrum of each ROI within the bandwidth 17-42 MHz. Significant discrimination between LFT/DFT and between LFT/CA was provided by maximum power and spectral slope (dBMHz-1). However, the greatest discriminative power was given by the y-axis (0 Hz) intercept of the spectral slope: LFT/DFT (p = 0.001); LFT/CA (p = 0.0001); and DFT/CA (p = 0.089).

Coronary Artery Disease↗
PubMed1997

Characterisation of red and white thrombus by intravascular ultrasound using radiofrequency and videodensitometric data-based texture analysis.

Visual assessment of intravascular ultrasound (IVUS) video images cannot reliably identify thrombus. We examined if texture analysis of radiofrequency (r.f.) data or videodensitometric data (VD) could distinguish thrombi of different ages and cell compositions. Whole human blood (red clot = RC), platelet-rich plasma (white clot = WC) and plasma (n = 6/group) were imaged at 4 and 24 h with 30 MHz IVUS transducers. At 4 h, VD- and r.f.-based analyses revealed significant differences between RC and WC with variance (VD red 26.4 +/- 2.5, white 33.9 +/- 7.8; r.f. red 1.4 +/- 0.5, white 4.9 +/- 1.3), kurtosis (VD red 0.29 +/- 0.9, white 0.23 +/- 0.3) and skewness (VD red 0.23 +/- 0.13, white 0.35 +/- 0.52; r.f. red 0.06 +/- 0.01, white -0.06 +/- 0.05). Also mean grey-level from both data sets was higher in RC (VD 134.8 +/- 18.0; r.f. -13.3 +/- 1.2) than in WC (VD 105.3 +/- 17.4, r.f. 16.5 +/- 2.2) (p < 0.01). With increasing time, variance increased in WC (5.5 +/- 1.5 at 24 h) and decreased in RC (0.9 +/- 0.3.3 at 24 h). The more heterogeneous structure of WC may be distinguished from that of RC using texture analysis of either VD or r.f.-signals.

Blood Coagulation↗
PubMed1997

Predicting desipramine levels in children and adolescents: a naturalistic clinical study.

OBJECTIVE: To determine the predictability and stability of desipramine (DMI) concentrations in a clinically treated sample of children, estimating the risk of developing potentially toxic DMI levels at a higher dose after a most recent level in a clinically acceptable range. METHOD: Subjects were 90 consecutive psychiatrically referred children and adolescents treated with DMI with at least two assays of serum DMI concentrations (462 pairs). Assay data were analyzed after log transformation and linear regression. RESULTS: Despite wide between-patient variability in serum DMI levels at the same dose, future within-subject DMI blood levels were highly predictable from knowledge of current levels, current dose, and the future dose. When the DMI serum level was 200 to 300 ng/ml, there was a 7.0% risk for subsequent levels at the same dose to exceed 300 ng/mL, but potentially toxic levels above 500 ng/mL were very infrequent (1.7%). CONCLUSIONS: Although the results of this naturalistic clinical study may not generalize to other situations, the results indicate a reasonable stability, predictability, and safety of DMI levels in individual psychiatrically treated children that result from clinically chosen dose changes.

Adolescent↗
PubMed1997

Attention-deficit hyperactivity disorder with bipolar disorder: a familial subtype?

OBJECTIVE: To clarify the nosological status of children with attention-deficit hyperactivity disorder (ADHD) who also satisfy diagnostic criteria for bipolar disorder (BPD). METHOD: Blind raters and structured psychiatric interviews were used to examine 140 children with ADHD, a sample of 120 non-ADHD comparisons, and their 822 first-degree relatives. Data analyses tested specific hypotheses about the familial relationship between ADHD and BPD. RESULTS: After stratifying the ADHD sample into those with and without BPD, the authors found that (1) relatives of both ADHD subgroups were at significantly greater risk for ADHD than relatives of non-ADHD controls; (2) the two subgroups did not differ significantly from one another in their relatives' risk for ADHD; (3) a fivefold elevated risk for BPD was observed among relatives when the proband child had BPD but not when the proband had ADHD alone; (4) an elevated risk for major depression with severe impairment was found for relatives of ADHD + BPD probands; (5) both ADHD and BPD occurred in the same relatives more often than expected by chance alone; and (6) there was a trend for random mating between ADHD parents and those with mania. CONCLUSIONS: The data suggest that comorbid ADHD with BPD is familially distinct from other forms of ADHD and may be related to what others have termed childhood-onset BPD.

Adolescent↗
PubMed1997

Attention deficit hyperactivity disorder (ADHD) is associated with early onset substance use disorders.

We evaluated the association between attention deficit hyperactivity disorder (ADHD) and the age of onset of psychoactive substance use disorders (PSUD) in adults with ADHD. We hypothesized that ADHD and psychiatric comorbidity would be risk factors for early onset PSUD. We compared 120 referred adults having a clinical diagnosis of childhood-onset ADHD with 268 non-ADHD adults. All diagnoses were obtained using DSM-III-R based structured psychiatric interviews. We used group comparisons of age at onset and Cox proportional hazard models to examine the development of PSUD over time. ADHD was associated with earlier onset of PSUD independently of psychiatric comorbidity. Conduct and juvenile bipolar disorders conferred a significantly increased risk for early onset PSUD independently of ADHD. Psychiatric disorders commonly emerged before the onset of PSUD in both groups. Persistent ADHD with and without psychiatric comorbidity was associated with adolescent onset PSUD. In addition, comorbidity with conduct and juvenile bipolar disorders predicted very early onset PSUD in both ADHD and non-ADHD individuals. These findings confirm and extend previous findings documenting important associations between PSUD and psychiatric comorbidity including persistent ADHD.

Adolescent↗
PubMed1996

Three-year follow-up of participants in a commercial weight loss program. Can you keep it off?

BACKGROUND: One third of Americans are obese, according to the 1988-1991 National Health and Nutrition Endpoint Survey III survey. Obesity increases the risk of death and a variety of chronic diseases. Numerous commercial weight loss programs demonstrate short-term success. OBJECTIVE: To assess maintenance of weight loss achieved during dieting. METHODS: We surveyed 192 participants in the Sandoz Nutrition (Sandoz Pharmaceuticals, Minneapolis, Minn) diet program approximately 3 years after participation. Initial date were supplied by the diet clinics and follow-up data, including weight at various points after the program, participation in other weight loss programs, and lifestyle variables, such as exercise, smoking, and television watching, were collected by a mailed questionnaire. RESULTS: On average, the group lost 22 kg during the diet program. After the follow-up period, the mean weight (mean, 102.6 kg) was only modestly less than the group's original weight at the start of the diet (mean, 105.9 kg). Twelve percent of the subjects maintained 75% of their weight loss after leaving the diet program, 57% maintained at least 5% of the loss, and 40% gained back more than they had lost during the diet. The frequency of exercise after the diet program was the strongest predictor of weight loss maintenance, while television viewing predicted a gain in weight. CONCLUSION: Given the apparent lack of substantial, long-term success at weight reduction, perhaps greater emphasis should be placed on prevention of obesity.

Commerce↗
PubMed1996

A prospective 4-year follow-up study of attention-deficit hyperactivity and related disorders.

BACKGROUND: Previous cross-sectional data showed that children and adolescents with attention-deficit hyperactivity disorder (ADHD) are at increased risk of comorbid conduct, mood, and anxiety disorders as well as impairments in cognitive, social, family, and school functioning. However, longitudinal data were needed to confirm these initial impressions. METHODS: Using DSM-III-R structured diagnostic interviews and raters blinded as to diagnosis, we reexamined psychiatric diagnoses at 1- and 4-year follow-ups in children with ADHD and controls. In addition, subjects were evaluated for cognitive, achievement, social, school and family functioning. RESULTS: Analyses of follow-up findings revealed significant differences between children with ADHD and controls in rates of behavioral, mood, and anxiety disorders, with these disorders increasing markedly from baseline to follow-up assessments. In addition, children with ADHD had significantly more impaired cognitive, family, school, and psychosocial functioning than did controls. Baseline diagnosis of conduct disorder predicted major depression and bipolar disorder at follow-up, and anxiety disorders at baseline predicted anxiety disorders at follow-up. CONCLUSION: These results confirm and extend previous retrospective results indicating that children with ADHD are at high risk of developing a wide range of impairments affecting multiple domains of psychopathology such as cognition, interpersonal, school, and family functioning. These findings provide further support for the value of considering psychiatric comorbidity in both clinical assessment and research protocols involving children with ADHD.

Achievement↗
PubMed1996

An image-processing strategy for the segmentation and quantification of microaneurysms in fluorescein angiograms of the ocular fundus.

Digital image-processing techniques can provide an objective and highly repeatable way of quantifying retinal pathology. This study describes an image-processing strategy which detects and quantifies microaneurysms present in digitized fluorescein angiograms. After preprocessing stages, a bilinear top-hat transformation and matched filtering are employed to provide an initial segmentation of the images. Thresholding this processed image results in a binary image containing candidate microaneurysms. A novel region-growing algorithm fully delineates each marked object and subsequent analysis of the size, shape, and energy characteristics of each candidate results in the final segmentation of microaneurysms. The technique is assessed by comparing the computer's results with microaneurysm counts carried out by five clinicians, using Receiver Operating Characteristic (ROC) curves. The performance of the automated technique matched that of the clinicians' analyses. This strategy is valuable in providing a way of accurately monitoring the progression of diabetic retinopathy.

Algorithms↗
PubMed1996

Predictors of persistence and remission of ADHD into adolescence: results from a four-year prospective follow-up study.

OBJECTIVE: To evaluate the predictors of persistence and the timing of remission of attention-deficit hyperactivity disorder (ADHD). METHOD: Subjects were 6- to 17-year old Caucasian, non-Hispanic boys with and without ADHD. DSM-III-R structured diagnostic interviews and blind raters were used to examine psychiatric diagnoses, cognitive achievement, social, school, and family functioning at a 4-year follow-up assessment. RESULTS: At the 4-year follow-up assessment, 85% of children with ADHD continued to have the disorder and 15% remitted. Of those who remitted, half did so in childhood and the other half in adolescence. Predictors of persistence were familiality of ADHD, psychosocial adversity, and comorbidity with conduct, mood, and anxiety disorders. CONCLUSIONS: The findings prospectively confirm that the majority of children with ADHD will continue to express the disorder 4 years later. For a minority of children, ADHD was a transient disorder that remits early in development. In addition, we have shown that persistence of ADHD is predictable. Familiality, adversity, and psychiatric comorbidity may be clinically useful predictors of which children with ADHD are at risk for a persistent disorder.

Achievement↗
PubMed1996

Pharmacotherapy of attention-deficit hyperactivity disorder across the life cycle.

OBJECTIVE: To evaluate the scope of the available therapeutic armamentarium in attention-deficit hyperactivity disorder (ADHD). METHOD: The literature of medication trials in ADHD was systematically reviewed, with attention to issues of psychiatric comorbidity, age, gender, and ethnic background. RESULTS: One hundred fifty-five controlled studies of 5,768 children, adolescents, and adults have documented the efficacy of stimulants in an estimated 70% of subjects. The literature clearly documents that stimulants not only improve abnormal behaviors of ADHD, but also self-esteem, cognition, and social and family function. However, response varied in different age groups and with certain comorbid conditions. In addition, there is an impressive body of literature documenting the efficacy of tricyclic antidepressants on ADHD in more than 1,000 subjects. Studies of alternative antidepressants, antipsychotics, antihypertensives, and other compounds were also reviewed. CONCLUSIONS: The available literature indicates the important role of psychopharmacological agents in the reduction of the core symptoms of ADHD and associated impairments. More research is needed on alternative pharmacological treatments and to further evaluate established therapeutics beyond school-age Caucasian boys. In addition, more research is needed on the efficacy of treatment for comorbid ADHD, use of combined medications, and the combination of medication and psychosocial treatment.

Adolescent↗
PubMed1995

Enrollment in the Health Alliance Plan HMO is not an independent risk factor for coronary artery bypass graft surgery.

BACKGROUND: Henry Ford Hospital is the sole provider of cardiac surgical services for the Health Alliance Plan, a health maintenance organization (HMO) that presently serves 450,000 enrollees. METHODS AND RESULTS: To determine the effect of managed care referral patterns on the outcome of coronary artery bypass graft (CABG) surgery, we retrospectively reviewed two concurrent groups of patients, 569 HMO patients and 225 patients with free-for-service (FFS) insurance, who had undergone isolated primary CABG surgery between January 1, 1990 and January 31, 1994. The 605 patients with Medicare operated on during the same time frame were excluded to obviate age bias. Age, sex, use of cardiac medications, history of prior percutaneous transluminal coronary angioplasty or thrombolytic therapy, history of recent and remote myocardial infarction, extent of coronary disease, presence of preexisting comorbid conditions, and incidence of unstable clinical syndromes and left ventricular dysfunction (ejection fraction < 40%) were comparable for both groups. In hospital mortality (HMO group, 1.9%; FFS group, 2.2%), mean ICU stay (HMO, 2.6 +/- 0.3 days; FFS, 2.3 +/- 0.3 days), and total hospital length of stay (HMO, 9.8 +/- 0.8 days; FFS, 8.6 +/- 0.6 days) were likewise similar. CONCLUSIONS: These data refute the notion that the gate-keeper mentality often associated with managed-care health insurance vehicles results in delayed referral of patients with coronary artery disease and results in suboptimal outcome.

Coronary Artery Bypass↗
PubMed1995

A double-blind, crossover comparison of methylphenidate and placebo in adults with childhood-onset attention-deficit hyperactivity disorder.

BACKGROUND: There are few controlled studies of methylphenidate hydrochloride in adults with attention-deficit hyperactivity disorder (ADHD), and their results have been equivocal. The discrepancies among these studies may be related to low doses, diagnostic uncertainties, and lack of attention to comorbid disorders. METHODS: We conducted a randomized, 7-week, placebo-controlled, crossover study of methylphenidate in 23 adult patients with DSM-III-R ADHD using standardized instruments for diagnosis, separate assessments of ADHD and depressive and anxiety symptoms, and a robust daily dose of methylphenidate hydrochloride, 1.0 mg/kg per day. RESULTS: We found a marked therapeutic response for methylphenidate treatment of ADHD symptoms that exceeded the placebo response (78% vs 4%, P < .0001). Response to methylphenidate was independent of gender, psychiatric comorbidity with anxiety or moderate depression, or family history of psychiatric disorders. CONCLUSION: Robust doses of methylphenidate are effective in the treatment of adult ADHD.

Adolescent↗
PubMed1995

Effects of moderate hyperglycemia on the temporal profile of brain tissue intracellular pH and [Mg2+] after global cerebral ischemia in rats.

In an attempt to understand the mechanisms by which preischemic plasma glucose (pg) worsens neurologic and neuropathologic outcomes, we investigated the effect of moderate preischemic hyperglycemia (200 mg/dl < mean plasma glucose < 360 mg/dl) on postischemic energy metabolism, tissue intracellular pH (pHi) and tissue free intracellular pMg (= -log[Mg2+]) over a one week period after transient global cerebral ischemia in the rat. In vivo 31P nuclear magnetic resonance spectroscopy was performed prior to and daily up to 1 week (wk) in rats after 12 min of forebrain ischemia, induced by bicarotid occlusion concurrent with systemic hypotension. Preischemic plasma glucose significantly affected 1 wk postischemic survival (p = 0.05, Fisher's exact test). The temporal profile of the brain tissue pHi was significantly different (p < 0.03) between the moderate hyperglycemic (H-1wk, n = 7, mean pg = 266.0 +/- 47.3 mg/dl) and the normoglycemic (N-1wk, n = 8, mean pg = 91.2 +/- 23.7 mg/dl) ischemic animals over 1 wk. Postischemic tissue alkalosis was measured at 24 (p = < 0.006) and 48h (p = 0.001) postischemia in the N-1wk group. A single marginally significant (p = 0.011) mean pHi upshift was measured at 72h postischemia in the H-1wk group. The mean change in pHi at 24h postischemia from the baseline values in moderate hyperglycemic animals that survived only 48h after ischemia (H-48h, n = 6, mean pg = 298.8 +/- 70.1 mg/dl) was significantly lower (p = 0.02) than that of the N-1wk ischemic animals.(ABSTRACT TRUNCATED AT 250 WORDS)

Alkalosis↗
PubMed1995

Quantitative image analysis of macular drusen from fundus photographs and scanning laser ophthalmoscope images.

Drusen are common features in the ageing macula and are associated with exudative age-related macular degeneration (ARMD). They appear as characteristic structures in indirect mode infrared scanning laser ophthalmoscope (SLO) images. Manual counting of drusen area in SLO images has shown no significant difference from that in standard fundus photographs in 6 eyes of 5 patients (p > 0.5). Computerised image processing techniques have been applied to digitised colour fundus photographs and indirect mode images to quantify the area of the macula affected by drusen in an automated fashion. Application of these methods may permit objective and repeatable assessment of the natural history of macular drusen. For a specificity of 90%, a sensitivity of 60% for colour fundus photographs and 35% for SLO images has been achieved, when compared with manual counting. The colour fundus photograph method also showed superior reproducibility compared with the SLO technique.

Aged↗
PubMed1995

Similarities in response to fluoxetine in the treatment of children and adolescents with obsessive-compulsive disorder.

OBJECTIVE: Obsessive-compulsive disorder (OCD) is a relatively common disorder that frequently has its onset in childhood and is associated with substantial morbidity and dysfunction despite availability of new treatments. However, antiobsessional agents have not been systematically evaluated in young children and their effectiveness beyond the short term has not been well studied. The purpose of this study was to evaluate the usefulness of fluoxetine in the long-term treatment of both children and adolescents with OCD. METHOD: All pediatric patients with a DSM-III-R diagnosis of OCD who were treated with fluoxetine were ascertained from retrospective chart reviews of a pediatric psychopharmacology clinic. Response to treatment was evaluated by experienced clinicians using the Clinical Global Impression Scale. RESULTS: Of 38 identified patients, 28 (74%) showed moderate to marked improvement of OCD symptoms on doses averaging 50 mg/day (1.0 mg/kg per day) over an average follow-up period of 19 months. Similar effects were observed in children and adolescents. CONCLUSION: Although limited by their retrospective nature, these findings indicate that fluoxetine may be effective in prepubertal children and that the effect can be sustained over time.

Adolescent↗