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Biomedical subjects

P Isaacs

Publications and source records attributed to P Isaacs.

At least 19 recordsLinked to original sources
PubMed2001

A conceptual model of child psychopathology: implications for understanding attention deficit hyperactivity disorder and treatment efficacy.

Highlights the desirability of using a theoretical framework for guiding the design and evaluation of therapeutic interventions for children with attention deficit hyperactivity disorder (ADHD). A general conceptual model is introduced and used to evaluate ADHD treatment outcome research. Treatments designed to target the substrate level (pharmacological interventions) result in broad, robust improvement in both core and peripheral areas of functioning. Those targeting hypothesized core features of the disorder (i.e., attention, impulsivity-hyperactivity) produce corresponding improvement in core and peripheral outcome measures with the exception of studies employing cognitive-behavior therapy. Those targeting peripheral features of the disorder effect change only in corresponding peripheral areas of functioning. Implications for clinical practice are discussed, and an alternative conceptual model of ADHD is introduced and compared with existing models.

Attention↗
PubMed2000

Upgrading the science and technology of assessment and diagnosis: laboratory and clinic-based assessment of children with ADHD.

Reviews the usefulness of clinic-based and laboratory-based instruments and paradigms for diagnosing attention deficit hyperactivity disorder (ADHD) and monitoring treatment effects. Extant literature examining the performance of normal children and those with ADHD on an extensive range of neurocognitive tests, tasks, and experimental paradigms indicates that particular types of instruments may be more reliable than others with respect to detecting between-group differences. We review task parameters that may distinguish the more reliable from less reliable instruments. The value of clinic-based and laboratory-based instruments for monitoring treatment response in children with ADHD is questionable when evaluated in the context of ecologically relevant variables such as classroom behavior and academic functioning. We present a general conceptual model to highlight conceptual issues relevant to designing clinic-based and laboratory-based instruments for the purposes of diagnosing and monitoring treatment effects in children with ADHD. Application of the model to currently conceptualized core variables indicates that attention and impulsivity-hyperactivity may represent correlative rather than core features of the disorder. We discuss implications of these findings for designing the next generation of clinic-based and laboratory-based instruments.

Attention Deficit Disorder with Hyperactivity↗
PubMed1997

Colonic tuberculosis and adenocarcinoma: an unusual presentation.

A case is presented of caecal tuberculosis coexisting with adenocarcinoma at the same site, unusually presenting as a right iliac fossa abscess. The relevant literature on 61 previously reported patients with coexisting tuberculosis and colonic carcinoma is reviewed. The patient was 81-years-old, female with a tender swelling in the right iliac fossa. Following examination by ultrasound, laparotomy was undertaken which revealed a large abscess cavity contaminated by Mycobacterium tuberculosis. Although anti-tuberculosis treatment was given, there was a persistent purulent discharge from the wound, so a new ultrasound, computed tomography scan and barium enema were arranged. These could not clearly differentiate between ileocaecal tuberculosis and carcinoma. A second laparotomy showed that there was an underlying adenocarcinoma. Although rare, the coexistence of colonic tuberculosis with carcinoma should be seriously considered especially in patients who fail to respond to anti-tuberculosis treatment. A definitive diagnosis can be established only by histological examination.

Adenocarcinoma↗
PubMed1996

Methylphenidate and attentional training. Comparative effects on behavior and neurocognitive performance in twin girls with attention-deficit/hyperactivity disorder.

The effectiveness of four doses (5-mg, 10-mg, 15-mg, 20-mg) of methylphenidate (MPH) and attentional training (AT) were evaluated using neurocognitive instruments (Continuous Performance Test; Matching Unfamiliar Figures Test), narrow- and broad-band rating scales in the context of a double-blind, placebo-control, within-subject reversal design for dizygotic twin girls with Attention-Deficit/Hyperactivity Disorder (ADHD). Both interventions proved effective for improving neurocognitive test performance and behavior, although broad-band ratings revealed dose-response curves different from those obtained from the neurocognitive tests. Implications for clinical management of girls with ADHD are discussed.

Attention↗
PubMed1987

A mixed pattern of endocrine cells in metaplastic Barrett's oesophagus. Evidence that the epithelium derives from a pluripotential stem cell.

In order to characterize the differentiation of endocrine cells present in Barrett's oesophagus and to determine if they express a single or multiple hormonal pattern, endoscopic biopsies were taken from both the lesion and the fundus of 45 patients and studied at the light microscopical level. Conventional histology revealed three different epithelial patterns: gastric atrophic fundic, intestinal and junctional. A mixture of these patterns was present in 28 cases (62%) and the single type was identified in 17 cases (38%). The use of three silver staining methods and antibodies to human chromogranins allowed us to identify numerous endocrine cells in all but 1 case. Eleven sera against all the most common hormones stored in the endocrine cells of the gut were used to identify the main products of the cells. The following immunoreactivities were identified: 5-hydroxytryptamine (5-HT) (in 75% of the studied cases), somatostatin (87%), motilin (31%), pancreatic polypeptide (PP) (20%), glucose-dependent insulinotropic polypeptide (20%), gastrin (15%), glucagon (15%), peptide tyrosine tyrosine (13%), secretin (7%) and neurotensin (2%). No cholecystokinin-immunoreactive cells were identified. Our results indicated that, in Barrett's epithelium, both gastric and intestinal endocrine cells differentiate, in accordance with the variability of differentiation in the non-endocrine cells present in the different types of columnar epithelium. These findings provide support for the conclusion that Barrett's epithelium arises from a pluripotential stem cell capable of both gastric and intestinal differentiation.

Aged↗
PubMed1987

Ischemic jejunal stenosis and blind loop syndrome after blunt abdominal trauma.

One month after suffering blunt abdominal trauma a patient developed severe steatorrhea and profound weight loss in association with an ischemic distal jejunal stricture and blind loop syndrome. Evidence for a partial mesenteric tear was found at resection of the stricture, which resulted in complete cure.

Blind Loop Syndrome↗
PubMed1986

Anorexia nervosa and pancreatic ascites.

Acute alcoholic pancreatitis was undiagnosed in a patient with anorexia nervosa who subsequently developed pancreatic ascites and oedema, wrongly attributed to protein malnutrition alone. She became hyperphagic in an attempt to reverse the malnutrition and hence the abdominal swelling, indicating that the goal of attaining a thin shape was the major determinant of the eating disorder in this patient. Measurement of ascitic fluid amylase concentration should be carried out in all patients with unexplained ascites.

Adult↗