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Biomedical subjects

B Wilson

Publications and source records attributed to B Wilson.

At least 91 records · Page 5Linked to original sources

General pharmacology of gemcitabine hydrochloride in animals.

Gemcitabine (2',2'-difluorodeoxycytidine monohydrochloride, LY188011 hydrochloride, CAS 122111-03-9) is a nucleoside analog with a broad spectrum of antitumor activity in murine models and is currently undergoing clinical evaluation. The profile of the pharmacological effects of this agent was assessed in studies evaluating the cardiovascular and respiratory systems, renal function, the gastrointestinal system, the central nervous system, and the autonomic nervous system. In vivo doses ranged from 0.15 to 300 mg/kg given by the intravenous route, while in vitro concentrations up to 1 x 10-3 mol/l were used. Gemcitabine was inactive in the autonomic nervous system, gastrointestinal function, and central nervous system studies. Only minimal changes were seen in the cardiovascular and respiratory study, with a slight decrease in pulmonary arterial pressure at the mid dose and a stroke volume increase at the high dose. In the renal function studies, a slight decrease in the urine pH at the high dose and decreased serum creatinine at the mid dose levels were observed. In summary, gemcitabine had minimal effect in these pharmacodynamic studies. These results indicate that gemcitabine has a low potential to produce adverse pharmacologic effects.

Animals↗

Staff nurse perception of job empowerment and organizational commitment. A test of Kanter's theory of structural power in organizations.

In this study, Rosabeth Kanter's structural theory of organizational behavior was tested in a nursing population by examining the relationship between 161 staff nurses' perceived job empowerment and their commitment to the organization. Data were collected using the Organizational Description Opinionnaire, the Organizational Commitment Questionnaire, a modified version of the Conditions for Work Effectiveness Questionnaire, and a demographic questionnaire. Consistent with Kanter's theory, a strong positive relationship was found between nurses' perceptions of power and opportunity and their commitment to the organization. In addition, overall empowerment was correlated positively with nurses' perceptions of their immediate managers' power. The results suggest that nurse administrators can empower their staff and improve organizational commitment by manipulating the structures in the work environment to allow greater access to the power and opportunity structures that Kanter maintains are important to overall work effectiveness.

Adult↗

Uniparental disomy occurs infrequently in Wilms tumor patients.

Wilms tumors commonly exhibit loss of heterozygosity for polymorphic DNA markers located on the short arm of chromosome 11 at band p15. In some instances, the deleted region does not include 11p13, the location of the WT1 gene, suggesting the existence of a second Wilms tumor gene on 11p. Both the exclusive loss of the maternally derived allele in Wilms tumors and the recent description of constitutional paternal isodisomy for this region in patients with either the Beckwith-Wiedemann syndrome (BWS) or isolated hemihypertrophy have suggested that this second locus is subject to sex-specific genomic imprinting. Given that one of these isodisomic patients had minimal congenital anomalies (hemihypertrophy), we hypothesized that a proportion of Wilms tumors which had not lost heterozygosity for 11p markers (about 60% of all cases) might have arisen consequent to 11p paternal heterodisomy and that patients constitutionally homozygous at 11p15 might harbor paternal isodisomy. We have analyzed 40 Wilms tumor cases to determine the parental origin of the child's 11p15 alleles. Paternal heterodisomy could be excluded in all 28 unilateral and 8/9 bilateral potential candidates. It is intriguing that somatic mosaicism for 11p paternal isodisomy was detected in one child with bilateral Wilms tumor and macroglossia. Isodisomy could only be excluded in one of the three possible cases. Thus, 11p paternal hetero- and isodisomy appear to be uncommon causes of non-anomaly-associated Wilms tumors but may be more frequent in Wilms tumor patients with BWS-associated anomalies.

Aneuploidy↗

Language and development in FG syndrome with callosal agenesis.

The FG syndrome is characterized by unusual facies, sudden infant death, developmental delay, and abnormalities of the cardiac, gastrointestinal, and central nervous systems. No longitudinal data on development in surviving patients are currently available. Serial evaluations of a patient with FG syndrome, whose sole central nervous system anomaly was agenesis of the corpus callosum, showed a consistent pattern over time. Specific language impairments in syntactic and pragmatic-semantic areas are emerging. These findings represent the first detailed data on which expectations for children with the FG syndrome can be based. The findings also fit theoretical constructs on the function of the corpus callosum and may therefore be generalized to provide expectations for other patients with isolated agenesis of the corpus callosum. Given the information gained from this case, it is clear that language intervention/consultation should be a pivotal service for such children, and that the speech-language pathologist should play a role in the development of an integrated educational services plan.

Abnormalities, Multiple↗

Neuropsychiatric aspects of HIV-1 infection in gay men: controlled investigation of psychiatric, neuropsychological and neurological status.

The aim of this study was to determine whether HIV infection is associated with psychiatric morbidity or neuropsychological impairment in asymptomatic and early symptomatic stages of disease in gay men. The subjects were 100 gay men (68 HIV-ve, 32 HIV+ve, 6 being CDC IV). All subjects were recruited at the time of requesting their first HIV test and the assessment was double-blind to HIV serostatus. There were no differences in psychiatric status or neuropsychological performance between the HIV-ve and HIV+ve groups. Multiple regression analysis and logistic regression were used to identify factors associated with psychiatric morbidity, neuropsychological impairment and subjective reporting of memory problems and physical symptoms for all 100 subjects. Previous psychiatric history and current illegal (non-dependent) drug use were associated with psychiatric morbidity, poor education was associated with neuropsychological impairment and psychiatric status (score on HAD and PSE) was associated with subjective reporting of memory problems and physical symptoms.

AIDS Dementia Complex↗

A feasibility study on quantitating myocardial perfusion with Albunex, an ultrasonic contrast agent.

Quantitating regional myocardial perfusion has been the much sought-after but still elusive goal of many intensive investigations over the years. Videodensitometry of the variation of myocardial echogenicity in two-dimensional (2-D) echocardiograms as a function of time in conjunction with the injection of a bolus of an ultrasound contrast agent has been used clinically as a tool for a direct assessment of regional myocardial perfusion, despite that the precise relationship between tissue echogenicity observed on an image and the echoes detected by the ultrasonic probe is unknown. A study was undertaken to determine whether ultrasonic backscatter calculated from unprocessed radio frequency (RF) echoes returned from myocardium could be used to quantitate regional myocardium perfusion. A real-time ultrasonic scanner has been modified and interfaced to a microcomputer to acquire RF data at a rate up to 10 frames per second. Preliminary experimental data were obtained from four open-chest dogs following intracoronary injection of a bolus of Albunex and two dogs following intravenous injection with this modified scanner. On one hand, these results indicate that the integrated backscatter measured from the region of myocardium perfused by the coronary artery where Albunex is injected and selected for monitoring initially increases, reaches a peak, and then decreases as the contrast agent is washed out and that the magnitude of the peak is approximately linearly proportional to the volume concentration of Albunex microspheres injected, clearly demonstrating the feasibility of this approach for quantitating region myocardial perfusion. On the other hand, intravenous injections did not result in any appreciable change in myocardial backscatter in the left ventricle although a response could be observed in the left ventricular blood pool.

Albumins↗

Cellulitis caused by Legionella pneumophila.

A patient with lymphoma presented with pneumonia. While receiving antibiotics, he developed a rapidly spreading cellulitis. The soft tissues were debrided in the operating room, and pathological examination showed fat necrosis and a fibrinopurulent exudate in the fibroadipose tissue; direct immunofluorescence of the debrided tissue revealed the presence of Legionella pneumophila. Culture of the specimen obtained during the operation yielded L. pneumophila. To our knowledge, this represents the first case report of cellulitis due to L. pneumophila.

Aged↗

Neuropsychological and SPECT scan findings during and after transient global amnesia: evidence for the differential impairment of remote episodic memory.

A patient had neuropsychological testing during, and at two days and seven weeks after a transient global amnesia (TGA) attack. During the attack she exhibited a characteristically profound anterograde amnesia but a limited remote memory loss; the most striking impairment was a deficit in personal episodic memory revealed by her performance on the Autobiographical Memory Interview. Personal and general semantic information was less impaired although there were indications of a temporal gradient in the impairment. When tested after the attack, she demonstrated normal anterograde and retrograde memory. A SPECT scan performed during TGA showed a focal reduction in cerebral perfusion in the postero-medial temporal lobes bilaterally which had resolved after seven weeks.

Amnesia↗

Irreversible inhibition of human cytomegalovirus replication by topoisomerase II inhibitor, etoposide: a new strategy for the treatment of human cytomegalovirus infection.

We demonstrated previously that human cytomegalovirus (CMV) infections could enhance the expression of cellular topoisomerase II and this enzyme activity is essential for CMV to replicate in vitro (Benson and Huang, 1988; Benson and Huang, 1990). In this study, we further show that in addition to m-AMSA and VM26 which we had previously reported, a widely used and clinically available drug, etoposide (VP-16 or VePesid) can irreversibly inhibit CMV replication at the drug concentration (2.5 micrograms/ml) greatly below toxic levels to stationary phase cells. Growing cells were more sensitive to etoposide than stationary phase cells and slight growth inhibition occurred at 2.5 micrograms/ml level. This inhibitor does not prevent the expression of CMV immediate-early and early genes, but can inhibit viral DNA and late viral-proteins synthesis. Because of their irreversible inhibitory effects and approval usage in clinical oncology, it is suggested that this group of compounds, particularly etoposide (VP-16), can be used to control life-threatening CMV infections, such as CMV pneumonitis and CMV retinitis, in cancer and immunocompromised patients or patients with AIDS.

Amsacrine↗

Developmental changes in the recognition and comprehension of facial expression: implications for frontal lobe function.

Children aged 6-15 years old and adults (over 18) were given three tests designed to test perception and comprehension of facial expression. In the first test subjects were given two composite symmetrical faces made from the left or right half of a normal face, the subjects' task being to indicate which composite more closely resembled the original face. In the second test the subjects matched a series of photographs from Life magazine with key photographs of one of six distinct emotions (sad, fear, happy, anger, disgust, surprise). In the third test the subjects chose a key photograph that was appropriate for the face of a faceless character in a cartoon. On the composite faces test the subjects in all groups exhibited a preference for the left visual field composite, implying that all age groups were processing the faces in a similar manner. The results of the other two tests showed that there was an improvement in the perception of facial expression between the ages of 6 and 8 years, little change until about 13 years, and then a second improvement to adult performance at about 14 years. The performance of the 8- to 13-year-old children was similar to that of adult patients with frontal lobe injuries, which could be taken as evidence that the regions of the frontal lobe involved in the performance of these tasks may not be mature until about 14 years of age.

Adult↗

Neuropsychological and psychiatric abnormalities in myalgic encephalomyelitis: a preliminary report.

Ten patients attending one general medical hospital clinic who fulfilled operational criteria for the diagnosis of myalgic encephalomyelitis (ME) and with a history longer than three months, underwent a series of standardized neuropsychological and psychiatric tests. Nine were able to complete the tests and were individually matched with a normal control group for age, sex, educational background and premorbid intelligence. The ME subjects showed inferior performance to the controls on two tests of verbal memory. Their personality scores displayed less extraversion and less psychoticism. This is the first report of objective neuropsychological abnormalities in patients with ME, suggesting a discrete deterioration of short-term memory. The findings may also suggest a concurrent psychiatric component of the condition, but the direction of causality remains to be clarified.

Anxiety Disorders↗

Recovery and compensatory strategies in head injured memory impaired people several years after insult.

A follow up study of 29 patients with traumatic head injury who were referred for memory therapy five to 10 years earlier is described. Of the original sample, 28 were traced, one had died, and one refused to take part, thus leaving 26 subjects who were seen and reassessed. Most (21) were living in their own homes with relatives, friends or alone; the others were in long term residential care or residential college or in warden controlled accommodation. Eleven subjects were in paid employment, although only one was in a position comparable to pre-injury status. On a standardised memory test some 58% of subjects showed no change since their last assessment several years earlier; 31% improved; and 11% deteriorated. The most encouraging finding was that subjects were using more memory aids and strategies now than before or at the end of their rehabilitation programme.

Adolescent↗

Reliability and construct validity of the Clinical Observations of Motor and Postural Skills.

The Clinical Observations of Motor and Postural Skills (COMPS) is a screening tool for children with motor incoordination. A study of reliability (test-retest, interrater, and internal consistency) and construct validity with 132 children, both with and without developmental coordination disorder, is reported here. Test-retest reliability over 2 weeks was high: .92 for a group of 48 children. Interrater reliability for occupational therapists experienced in pediatrics was also excellent: .87 for a group of 72 children. Internal consistency of the COMPS was high, particularly when one of the seven items (Schilder's arm extension) was deleted. The test discriminates well between children with and without motor problems and has many properties of a good screening test.

Child↗