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Biomedical subjects

P Wilson

Publications and source records attributed to P Wilson.

At least 253 records · Page 14Linked to original sources
PubMed1991

Effect of neonatal denervation of hindlimb digits on the somatotopic organization of lumbar spinocervical tract neurons in the cat.

1. The effect of transection and ligation of the digital nerves of either one (toe 3) or two (toe 3 and toe 4) hindpaw digits, in the first postnatal week, on the tactile receptive fields (RFs) of spinocervical tract (SCT) neurons was studied in adult, alpha-chloralose-anesthetized cats. Immediately before recording, the digital nerves of the corresponding digit(s) of the opposite, intact hindpaw were transected, and the neonatally lesioned digital nerves were recut proximal to the transection neuroma. 2. In the medial part of the dorsal horn at the L6-L7 level, the digits of the hindlimb are represented in the RFs of SCT cells in a precise axial sequence from the most medial digit (toe 2) rostrally to the most lateral digit (toe 5) caudally. Acute denervation of one or two digits in the adult produced an area in the ipsilateral dorsal horn in which SCT cells lacked any RFs. When acute denervation was restricted to a single digit, the unresponsive region of dorsal horn was approximately 3 mm in length, and when two digits were denervated the unresponsive zone was approximately 6 mm long. Because the representation of the toes of the left hindpaw is a mirror image of that of the right, the rostrocaudal extent and position of the region of unresponsive SCT cells was used to assess the location of the borders of the chronically deprived region on the opposite side of the cord. 3. In all cats examined after neonatal denervation of toe 3, most (89%) of the SCT cells sampled within the chronically deprived toe 3 representation had RFs. These RFs were either on toe 2 (44%) or toe 4 (18%), and a large proportion of cells (38%) had multiple RFs with components on both toe 2 and toe 4. In most cases the cells fired briskly to displacement of hairs or light touch of the skin within these RFs. SCT cells with a RF on toe 2 and/or toe 4 were found throughout the whole 3-mm length of the chronically deprived toe 3 region, but cells with a RF on toe 2 were more commonly found than cells with a RF on toe 4 at axial distances greater than or equal to 1.5 mm from the boundary of the normal representations of the respective digit. 4. After chronic, neonatal denervation of both toe 3 and toe 4, 59% of SCT cells sampled overall had RFs, but there was a large degree of interanimal variation in the proportion of unresponsive neurons.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗
PubMed1991

Evidence for reduced fibrinolytic activity in unstable angina at rest. Clinical, biochemical, and angiographic correlates.

BACKGROUND: The goal of this study was to evaluate the role of the fibrinolytic system in patients with unstable angina at rest associated with transient electrocardiographic changes. METHODS AND RESULTS: Tissue plasminogen activator activity in plasma was comparable among patients with unstable angina (n = 17), patients with stable exertional angina (n = 10), and control patients with normal coronary arteriograms (n = 8). In contrast, plasminogen activator inhibitor-1 (PAI-1) activity in plasma was elevated in the unstable angina group (21.67 +/- 9.52 AU/ml) as compared with either the stable angina group (12.01 +/- 7.06 AU/ml, p less than 0.02) or the controls (12.49 +/- 8.54 AU/ml, p less than 0.02). Coronary angiography performed within 24 hours after the last anginal episode showed a similar extent of coronary artery disease in the unstable and stable angina groups. However, intracoronary thrombi were observed in eight patients in the unstable angina group while no thrombus was noted in the stable angina group (chi 2 = 7.22, p less than 0.01). CONCLUSIONS: We conclude that patients with unstable angina at rest have a reduced fibrinolytic activity and an increased incidence of intracoronary thrombi. It is postulated that elevated PAI-1 activity in the presence of coronary arterial wall injury may be an important factor leading to the development of acute coronary syndromes.

Angina Pectoris↗
PubMed1991

Cell rearrangement during gastrulation of Xenopus: direct observation of cultured explants.

We have analyzed cell behavior in the organizer region of the Xenopus laevis gastrula by making high resolution time-lapse recordings of cultured explants. The dorsal marginal zone, comprising among other tissues prospective notochord and somitic mesoderm, was cut from early gastrulae and cultured in a way that permits high resolution microscopy of the deep mesodermal cells, whose organized intercalation produces the dramatic movements of convergent extension. At first, the explants extend without much convergence. This initial expansion results from rapid radial intercalation, or exchange of cells between layers. During the second half of gastrulation, the explants begin to converge strongly toward the midline while continuing to extend vigorously. This second phase of extension is driven by mediolateral cell intercalation, the rearrangement of cells within each layer to lengthen and narrow the array. Toward the end of gastrulation, fissures separate the central notochord from the somitic mesoderm on each side, and cells in both tissues elongate mediolaterally as they intercalate. A detailed analysis of the spatial and temporal pattern of these behaviors shows that both radial and mediolateral intercalation begin first in anterior tissue, demonstrating that the anterior-posterior timing gradient so evident in the mesoderm of the neurula is already forming in the gastrula. Finally, time-lapse recordings of intact embryos reveal that radial intercalation takes places primarily before involution, while mediolateral intercalation begins as the mesoderm goes around the lip. We discuss the significance of these findings to our understanding of both the mechanics of gastrulation and the patterning of the dorsal axis.

Animals↗
PubMed1990

Attitudes to chemotherapy: comparing views of patients with cancer with those of doctors, nurses, and general public.

OBJECTIVE: To compare responses of patients with cancer with those of a matched control group, cancer specialists, general practitioners, and cancer nurses in assessing personal cost-benefit of chemotherapy. DESIGN: Prospective study of consecutively recruited patients with cancer and other groups by questionnaire; half of the patients received the questionnaire again three months after starting treatment. SETTING: A medical oncology ward of a London teaching hospital. SUBJECTS: 106 Patients with newly diagnosed solid tumours referred to the unit for consideration of treatment with cytotoxic chemotherapy, 100 of whom were able to complete the questionnaire. 100 Matched controls, 315 cancer doctors (238 radiotherapists and 77 medical oncologists), 1500 randomly chosen general practitioners, and 1000 randomly chosen cancer nurses. MAIN OUTCOME MEASURES: Percentage chance of cure, prolonging life, or palliation of symptoms required to make treatment worth while with two hypothetical chemotherapy treatments, with severe and mild side effects respectively. RESULTS: Respondents to the questionnaire comprised 100 patients, 100 controls, 60 (78%) medical oncologists, 88 (37%) radiotherapists, 790 (53%) general practitioners, and 303 (30%) cancer nurses. Most patients were willing to accept intensive chemotherapy for a very small chance of benefit. The median benefit required to make the hypothetical intensive treatments worth while for patients compared with controls were: for chance of a cure (range 1 to 100%) 1% v 50%, for prolonging life (range three months to five years) 12 months v 24-60 months, and for relief of symptoms (range 1 to 100%) 10% v 75% respectively. There were no significant differences in the responses of the 50 patients completing the questionnaire on a second occasion. Doctors and nurses were less likely to accept radical treatment for minimal benefit compared with the patients (median scores 10-50%, 12-24 months, and 50-75%, for chance of cure, prolonging life, and relief of symptoms respectively). Significantly more patients than controls accepted treatments giving the minimal benefit for each category (cure 53.1 v 19.0%, 67.0 v 35.0%; prolonging life 42.1 v 10.0%, 53.0 v 25.0%; relief of symptoms 42.6 v 10.0%, 58.7 v 19.0% for intensive and mild treatments respectively, p less than 0.001) as was the case for comparison of patients with other groups. CONCLUSION: Patients with cancer are much more likely to opt for radical treatment with minimal chance of benefit than people who do not have cancer, including medical and nursing professionals. This could be taken into account when discussing treatment options with patients and their relatives.

Antineoplastic Agents↗
PubMed1990

Apical hypertrophic cardiomyopathy presenting with sustained monomorphic ventricular tachycardia and electrocardiographic changes simulating coronary artery disease and left ventricular aneurysm.

A 52-year-old male presented with sustained monomorphic ventricular tachycardia as the initial manifestation of apical hypertrophic cardiomyopathy. The electrocardiogram during normal sinus rhythm showed a pattern of an old anterior wall myocardial infarction with aneurysm formation. Cardiac catheterization documented angiographically normal coronary arteries. Apical hypertrophic cardiomyopathy was documented at cardiac catheterization and by echocardiogram and Doppler studies. Monomorphic ventricular tachycardia was reproducibly initiated and terminated during electrophysiological studies and antiarrhythmic drugs failed to control the tachycardia. At the time of implantation of a cardioverter defibrillator, left ventricular apical biopsy revealed pathologic findings characteristic of hypertrophic cardiomyopathy.

Cardiomyopathy, Hypertrophic↗
PubMed1990

Hemisphere priming through practice in a musical chords task.

In a study of selective hemisphere activation, the performance of 30 subjects given either a "local" or "global" priming activity before and after a monoaurally presented chord analysis task was compared with an unprimed control group. The hypothesis was that ear advantage scores on the chords task would show increased left hemisphere involvement following local priming and increased right hemisphere involvement following global priming. The results failed to support this hypothesis. All subjects, however, regardless of priming condition, showed a very strong practice effect represented by a shift from a weak initial left ear (right hemisphere) advantage towards a significant right ear (left hemisphere) advantage (P less than 0.00006). The findings suggest that although the local/global priming activity did not lead to selective hemisphere activation, repeated exposure to the chords task resulted in increased use of analytic left hemisphere processing strategies as subjects became familiar with its processing requirements.

Adolescent↗
PubMed1990

Solitary plasmacytoma of the frontal bone.

We report a case of a solitary, painless, lytic lesion in the frontal bone in an otherwise asymptomatic patient. This was investigated with plain radiographs, computed tomography (CT), angiography and finally biopsy. Histology showed it to be a plasmacytoma. The radiological features of this lesion are discussed. Solitary plasmacytoma of bone has an uncertain relationship to multiple myeloma; it has only rarely been described in the skull and very rarely in the frontal bone.

Adult↗
PubMed1990

Attitudes, knowledge, experience and behaviour related to HIV and AIDS among Zimbabwean social workers.

A recent study of Samuels & Boyle (1989) examined knowledge, attitudes, and behaviours of social service team members in Newham, East London in relation to HIV and AIDS. This study extends theirs to investigate social workers, both experienced and in training, in Harare, Zimbabwe, Whilst overall, there appear to be high levels of knowledge and positive attitudes displayed by these social workers, detailed examination of their responses shows gaps in knowledge and ambivalent attitudes and behaviours. These issues should be addressed when planning AIDS training courses.

Acquired Immunodeficiency Syndrome↗
PubMed1990

Characterization of monoclonal antibodies reactive with normal resting, lactating and neoplastic human breast.

Mouse monoclonal antibodies reacting with human mammary gland constituents have been generated and characterized in an attempt to raise breast- or breast-cancer-specific antisera. The immunogens used in these studies included fractionated human milk fat globule membrane, the human breast cancer cell line MCF7 and a crude membrane preparation derived from an axillary nodal metastasis from a patient with breast cancer. Of the antibodies obtained, 8 were characterized and found to bind to different structures in the normal breast. The antibody LICR-LON-LC28 recognizes secretory component and binds strongly to normal resting and lactating breast, but only focally to a minority of breast carcinomas. The antibodies LICR-LON-14.1 and 32.2 react strongly with the lactating breast and recognize kappa- and beta-casein, respectively. Caseins are not produced by breast tumors. The antibodies LICR-LON-TW19.5, H10A and 39.8 all react with carbohydrate epitopes and bind heterogeneously to normal resting breast luminal epithelium and cellular subsets of breast carcinomas. LICR-LON-59.2 and 19.2 react with normal breast myoepithelial cells and the basement membrane, respectively. LICR-LON-59.2 is unusual as a myoepithelial marker in that it stains cells in the majority of breast carcinomas. LICR-LON-19.2 shows extensive reactivity to tumor cell lines in culture but has no reactivity with carcinoma cells from breast biopsies.

Animals↗
PubMed1989

Immunohistochemical study of beta- and kappa-casein in the human breast and breast carcinomas, using monoclonal antibodies.

The immunohistochemical analysis of human beta- and kappa-caseins in the human breast, benign breast disease, and breast carcinomas is reported. The monoclonal antibodies LICR-LON-32.2 and LICR-LON-14.1 which react with human beta- and kappa-casein, respectively (Earl, H. M., and McIlhinney, R. A. J. Mol. Immunol., 22: 981-991, 1985) were used for these studies. Human beta- and kappa-caseins were detected in lactating human breast tissue, lactational foci in the resting breast, and heterogeneously in the 16th-week pregnant breast, but not in normal breast tissue. In benign breast disease occasional epithelial cells were demonstrated to synthesize beta- and kappa-caseins, but this finding did not appear to correlate with the hormonal status or previous obstetric histories of the patients. However, similar studies in 45 breast carcinomas with a wide range of estrogen receptor content, demonstrated no detectable beta- or kappa-casein. These results demonstrate that the caseins, which are biochemical markers of mammary gland differentiated function, and have been previously put forward as markers of breast cancer, were not synthesized in the 45 human breast carcinomas studied here, even in tumors with high levels of estrogen receptor protein.

Antibodies, Monoclonal↗