Search PubMed⌕ Search

Biomedical subjects

C W Sharp

Publications and source records attributed to C W Sharp.

At least 19 recordsLinked to original sources
PubMed1996

Implications of comorbidity for genetic studies of bipolar disorder: P300 and eye tracking as biological markers for illness.

In large families with affective illness, identification of a biological variable is needed that reflects brain dysfunction at an earlier point than symptom development. Eye movement disorder, a possible vulnerability marker in schizophrenia, is less clearly associated with affective illness, although a subgroup of affective disorders shows smooth-pursuit eye movement disorder. The auditory P300 event-related potential may be a useful marker for risk to schizophrenia, but a role in bipolar illness is less certain. The distribution of these two biological variables and their association with symptoms in two multiply affected bipolar families is described. In a single, five-generation family identified for linkage studies through two bipolar I (BPI) probands, 128 members (including 20 spouses) were interviewed. The 108 related individuals had diagnoses of BPI (7), bipolar II (2), cyclothymia (3), or major depressive disorder (19). Eight others had generalised anxiety (1), minor depression (5), intermittent depression (1), or alcoholism (1). Sixty-nine subjects had no psychiatric diagnosis. P300 latency (81) and eye tracking (71) were recorded from a subgroup of relatives within the pedigree. Eye tracking was abnormal in 11 of 71 relatives (15.5%) and was bimodally distributed. In these 11 relatives, clinical diagnoses included minor depression (1), alcoholism (1) and generalised anxiety disorder (1). P300 latency was normally distributed and did not differ from controls. In a second family in which five of seven siblings have BPI illness, P300 latency and eye movement disorder were found in affected relatives and in some unaffected offspring. In these large families, clinical diagnoses of general anxiety, alcoholism and minor depression, when associated with eye tracking abnormality, may be considered alternative clinical manifestations of the same trait that in other relatives is expressed as bipolar illness.

Anxiety Disorders↗
PubMed1995

Auditory P300 event-related potentials and neuropsychological performance in schizophrenia and bipolar affective disorder.

The auditory P300 event-related potential (ERP) and performance on neuropsychological tests were evaluated in 26 subjects with schizophrenia, 19 with bipolar affective disorder, and 27 controls. The schizophrenic and the bipolar groups were similar in having prolonged P300 latency recorded from central and temporal leads. The P300 was significantly reduced in amplitude in the schizophrenic group at midline leads and the left temporal lead but was not significantly reduced in amplitude at any electrode site when the bipolar group was compared to controls. Schizophrenics performed significantly less well than bipolars and controls on tests of verbal fluency and, within this group, a significant correlation was found between the latency of P300 and verbal fluency test scores. While the bipolar group of patients was similar to the schizophrenic group in having prolonged P300 latency, these groups differed in P300 amplitude, performance on verbal fluency tests, and the relationship between the physiological and neuropsychological variables.

Adolescent↗
PubMed1994

Schizophrenia and mental retardation associated in a pedigree with retinitis pigmentosa and sensorineural deafness.

A family is presented with multiple cases of mild mental retardation, schizophrenia and other functional psychoses, progressive hearing loss, and retinitis pigmentosa (RP). It closely resembles a previously reported Finnish family. We suggest that the phenotypes are not associated in this family by chance, but define a novel syndrome which may be caused by a mutant allele at a single genetic locus.

Adolescent↗
PubMed1994

Clinical presentation of anorexia nervosa in males: 24 new cases.

As part of a larger prognostic study of anorexia nervosa, clinical features at presentation of 24 males with anorexia are described, and compared with a female group matched for date of admission. Data were extracted from the original case records and follow-up interview. The study confirms the view that males display the classical syndrome of anorexia nervosa, but differs from previous studies in several respects. Age at onset (mean 18.6 years) and at presentation (mean 20.2 years) is later, with a mean duration of illness at presentation of only 1.6 years. A premorbid tendency to obesity is confirmed; maximum weight loss during the illness amounted to 42% matched population mean weight (MPMW), and weight at presentation was 78.5% MPMW, somewhat higher than the female group. In keeping with earlier studies, binging and vomiting were noted commonly, in around half of sufferers, but laxative abuse was less frequent and excessive exercising more frequent in males. Depressive and obsessional symptoms are common in both groups, and a strong family history of affective disorders and alcohol abuse was noted in over one third.

Adolescent↗
PubMed1994

Methodological considerations in measurement of the P300 component of the auditory oddball ERP in schizophrenia.

Twenty-three schizophrenic patients and 26 age-matched control subjects were studied using the P300 recorded during the auditory oddball task, with counting. Our aim was to assess the most suitable method of measurement and analysis of P300 amplitude and latency for use in clinical studies of schizophrenia. The effect of high-pass filtering, peak definition method and recording electrode site were all investigated. We have developed a technique, based on a least-mean-squares approximation to data, which seems particularly well suited to dealing with multi-peak P300 complexes. We have also investigated the spectral composition of the P300 and have found some evidence to support a proposed 2-frequency model of the P300 complex.

Acoustic Stimulation↗
PubMed1994

Correlation of regional cerebral blood flow equivalents measured by single photon emission computerized tomography with P300 latency and eye movement abnormality in schizophrenia.

Single photon emission tomography with the intravenous blood flow marker 99mTc-exametazime was carried out in 14 acutely ill drug-free schizophrenic patients from whom P300 event-related potential, smooth eye pursuit eye tracking and verbal fluency were measured within a few days of scanning. Smooth pursuit eye movement abnormality correlated significantly with abnormal tracer uptake in superior pre-frontal cortex on the right and left and inferior pre-frontal cortex on the left. Abnormal eye movement was also associated with higher tracer uptake in left anterior cingulate and left posterior cingulate. P300 latency was significantly correlated with higher tracer uptake in left superior pre-frontal and left parietal regions. Verbal fluency performance was negatively correlated with tracer uptake in left frontal region. Eye tracking abnormality in schizophrenia is associated with bilateral frontal lobe disturbance and P300 latency increase with left-sided frontal and temporoparietal dysfunction. There was, however, a significant inverse relation between eye tracking abnormalities and abnormal perfusion in the left anterior cingulate region.

Adult↗
PubMed1993

Anorexia nervosa and depression in a woman blind since the age of nine months.

A woman aged 58 who has been blind since the age of nine months presented with major depression and a 40 year history of an eating disorder characterized by a restriction of food intake and body disparagement. The case is additional evidence that a specifically visual body image is not essential for the development of anorexia nervosa and supports the view that the concept of body image is unnecessary and unproductive in eating disorders. Greater emphasis should be placed on attitudes and feelings toward the body, and the possibility of an eating disorder should be considered in cases of older women with an atypical presentation.

Anorexia Nervosa↗
PubMed1993

The medical complications of anorexia nervosa.

The physical complications of anorexia nervosa are common and can be life threatening, but psychiatrists and the increasing number of non-medical therapists involved in treatment programmes often overlook these complications. Cardiovascular complications are the most common, and the most likely to result in fatalities, particularly in those patients who vomit, purge or abuse diuretics, because of the electrolyte abnormalities induced. Osteoporosis is an early and perhaps irreversible consequence of severe weight loss. Further, there are dangers in rapid intravenous hyperalimentation.

Anorexia Nervosa↗
PubMed1991

Immediate enteral feeding in burn patients is safe and effective.

Recent animal studies indicate that immediate enteral feeding may be beneficial in patients with major burns. Yet, largely because of the fear of complications, immediate enteral feeding is not commonly performed in patients with major burns until after the resuscitation period. The purpose of this study was to evaluate the safety and efficacy of immediate enteral tube feedings in patients with burns larger than 20% of their body surface area. The daily intake of enteral feedings begun immediately (less than 6 hours) after burn was measured during the first 7 days after burn in 106 consecutive patients with a mean +/- SD burn size of 40% +/- 21%. The incidence of complications related to enteral feeding was low; aspiration pneumonia did not occur. Vomiting was the major complication observed and occurred 21 times in 16 patients during the 745 study days (2.8% daily incidence). The mean number of calories absorbed enterally increased daily and met the patient's calculated resting energy expenditure (REE) on day 3 after burn (99% +/- 7% REE). The results of this study indicate that immediate enteral feeding is a safe and effective method of delivering nutritional support to burn victims with major burns.

Adolescent↗