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Biomedical subjects

G Scott

Publications and source records attributed to G Scott.

At least 37 records · Page 2Linked to original sources
PubMed2001

Analgesic and antipyretic effects of Dodonaea angustifolia and Salvia africana-lutea.

Water extracts of Dodonaea angustifolia L. and Salvia africana-lutea L., were investigated for analgesic and antipyretic activities using acetic acid writhing and hot plate tests, and lipopolysaccharide (LP)-induced pyrexia test in mice and rats, respectively. D. angustifolia and S. africana-lutea significantly inhibited acetic acid-induced writhing and also significantly delayed the time of reaction of mice to thermal stimulation produced by the hot plate. D. angustifolia and S. africana-lutea significantly reduced fever induced by LP. Paracetamol produced similar effects to D. angustifolia and S. africana-lutea on the acetic acid-induced writhing but has no effect on hot plate-induced nociception and on pyrexia produced by LP. These data indicate the analgesic and antipyretic potential of D. angustifolia and S. africana-lutea.

Analgesics↗
PubMed2001

Programmed-life plastics from polyolefins: a new look at sustainability.

The term "sustainable" is often assumed to be synonymous with "renewable". However, polymers made from renewable natural resources are not necessarily eco-efficient. Cellulose-based polymers utilize more nonrenewable fossil fuels and are more polluting during manufacture than petro-based polymers. Sustainable polymers also have to be industrially acceptable, and although ultimate biodegradability in the natural environment is important, polymer-based products are required to biodegrade in a controlled way. Service life may be a year or more before the commencement of environmental degradation occurs. Many natural polymers such as rubber, lignin, and humus, like the synthetic polyolefins, biodegrade by an oxidative mechanism (oxo-biodegradation), and consequently much of nature's biological waste cannot satisfy the rapid mineralization criteria currently advocated by standards committees for synthetic polymers. Although biometric tests are more convenient to use than full composting tests, they are meaningless when applied to hydrocarbon polymers, whether natural or synthetic, since oxo-biodegradation is a slower process than hydro-biodegradation at ambient temperatures. Biodegradation standards currently proposed are unrealistic and will need to be modified on the basis of recent scientific evidence.

Biodegradation, Environmental↗
PubMed2001

Follicular mycosis fungoides: a case report and review of the literature.

BACKGROUND: Follicular mycosis fungoides is an unusual variant of mycosis fungoides (MF). Unlike classic MF where atypical lymphocytes show a predilection for the epidermis (epidermotropism), follicular MF displays a malignant lymphocytic infiltrate tropic for hair follicles (folliculotropism). This malignant lymphocytic infiltrate results in follicular disruption typically manifesting clinically as plaques, comedones and follicular papules. METHODS: This report describes a 40-year-old patient with follicular MF presenting as nodules on the face and chest. Histologic examination of the patient's biopsy revealed a folliculocentric infiltrate of atypical lymphocytes with sparing of the epidermis. RESULTS AND CONCLUSIONS: Our case is discussed in the context of previously reported cases of follicular MF; we also include a review of all cases of follicular MF published to date that meet the strict criterion for this diagnosis.

Administration, Topical↗
PubMed2001

Protease-activated receptor 2, a receptor involved in melanosome transfer, is upregulated in human skin by ultraviolet irradiation.

Previous studies have shown that the protease-activated receptor 2 is involved in skin pigmentation through increased phagocytosis of melanosomes by keratinocytes. Ultraviolet irradiation is a potent stimulus for melanosome transfer. We show that protease-activated receptor 2 expression in human skin is upregulated by ultraviolet irradiation. Subjects with skin type I, II, or III were exposed to two or three minimal erythema doses of irradiation from a solar simulator. Biopsies were taken from nonexposed and irradiated skin 24 and 96 h after irradiation and protease-activated receptor 2 expression was detected using immunohistochemical staining. In nonirradiated skin, protease-activated receptor 2 expression was confined to keratinocytes in the lower one-third of the epidermis. After ultraviolet irradiation protease-activated receptor 2 expression was observed in keratinocytes in the upper two-thirds of the epidermis or the entire epidermis at both time points studied. Subjects with skin type I showed delayed upregulation of protease-activated receptor 2 expression, however, compared with subjects with skin types II and III. Irradiated cultured human keratinocytes showed upregulation in protease-activated receptor 2 expression as determined by immunofluorescence microscopy and Western blotting. Cell culture supernatants from irradiated keratinocytes also exhibited a dose-dependent increase in protease-activated receptor-2 cleavage activity. These results suggest an important role for protease-activated receptor-2 in pigmentation in vivo. Differences in protease-activated receptor 2 regulation in type I skin compared with skin types II and III suggest a potential mechanism for differences in tanning in subjects with different skin types.

Adult↗
PubMed2001

Discharge patterns of neurons in the medial pontobulbar reticular formation during fictive mastication in the rabbit.

In this study, we describe functional characteristics of neurons forming networks generating oral ingestive motor behaviours. Neurons in medial reticular nuclei on the right side of the brainstem between the trigeminal and hypoglossal motor nuclei were recorded in anaesthetized and paralysed rabbits during two types of masticatory-like motor patterns induced by electrical stimulation of the left (contralateral) or right (ipsilateral) cortical masticatory areas. Sixty-seven neurons in nucleus reticularis pontis caudalis (nPontc), nucleus reticularis parvocellularis (nParv), and nucleus reticularis gigantocellularis (Rgc) were studied. These were classified as phasic or tonic depending on their firing pattern during the fictive jaw movement cycle. Phasic neurons located in the dorsal part of nPontc were active during the jaw opening phase, whilst those in dorsal nParv tended to fire during the closing phase. In most neurons, burst duration and firing frequency changed between the two motor patterns, but there was little change in phase of firing. Tonic units were mainly recorded in the ventral half of nPontc, and at the junction between Rgc and caudal nParv. Cortical inputs with short latency from the contralateral masticatory area were more frequent in phasic (82%) than tonic (44%) neurons, whilst inputs from the ipsilateral cortex were equal in the two subgroups (57% and 56%). Phasic neurons had significantly shorter mean contralateral than ipsilateral cortical latencies, whilst there was no difference among tonic neurons. Intra- and perioral primary afferent inputs activated both types of neurons at oligo-synaptic latencies. Our results show that subpopulations of neurons in medial reticular nuclei extending from the caudal part of the trigeminal motor nucleus to the rostral third of the hypoglossal motor nucleus are active during the fictive masticatory motor behaviour. Unlike masticatory neurons in the lateral tegmentum, the medial subpopulations are spatially organized according to discharge pattern.

Action Potentials↗
PubMed2001

First experience of topical SDZ ASM 981 in children with atopic dermatitis.

BACKGROUND: SDZ ASM 981 is a selective inhibitor of inflammatory cytokine release under development for the topical treatment of atopic dermatitis. OBJECTIVES: This first paediatric study was designed to measure the systemic exposure to SDZ ASM 981 in young children with atopic dermatitis treated on extensive skin areas. METHODS: Children 1-4 years of age referred to a tertiary care centre for their atopic dermatitis were treated twice daily for 3 weeks with 1% SDZ ASM 981 cream. SDZ ASM 981 blood concentrations were measured on day 4 and 22 (last day) of treatment, and 1 week after the last application, using a radioimmunoassay with a limit of quantification of 0.5 ng mL(-1). Efficacy was assessed by the Eczema Area Severity Index (EASI). RESULTS: The 10 patients included had 23-69% of their body surface area (BSA) affected at baseline. Of the 63 SDZ ASM 981 blood concentrations measured, 63% were < 0.5 ng mL(-1); the maximum value observed was 1.8 ng mL-1. No accumulation was evidenced between days 4 and 22. The first two patients experienced a flare of atopic dermatitis that was not controlled by the study medication. In the other patients, the EASI improved by 8-89% at 3 weeks of treatment. CONCLUSIONS: In these children 1-4 years of age, blood concentrations of SDZ ASM 981 during topical treatment with the 1% cream were consistently low even in the children with the most extensive areas treated (up to 69% of their BSA).

Administration, Cutaneous↗
PubMed2001

Pseudotumour in von Willebrand disease.

Pseudotumour is a rare complication of haemophilia; it has previously been reported in patients with moderate or severe haemophilia and rarely in mild disease. We report a case of a proximal pseudotumour occurring in a 36-year-old patient with mild von Willebrand disease (vWD) who made a good recovery with conservative management. Surgery has been advocated as the optimal treatment for proximal pseudotumours due to the risk of continued bleeding and progression. However, in mild haemophilia or vWD, where the risk of spontaneous bleeds is low, conservative management may be an appropriate alternative.

Adult↗
PubMed2001

Rab3a and SNARE proteins: potential regulators of melanosome movement.

Melanosomes are specialized organelles that undergo a dynamic process of transport along the melanocyte dendrite to the dendrite tip and transfer to keratinocytes. We hypothesized that soluble N-ethylmaleimide-sensitive factor attachment protein receptors (SNARE), which are involved in membrane fusion, and rab3a, a GTP-binding protein involved in exocytosis in neuronal cells and in SNARE complex assembly, may play a part in melanosome transport and transfer. By reverse transcription-polymerase chain reaction we identified transcripts for rab3a, vesicle-associated membrane protein-2, synaptosome-associated proteins of 23 kDa and 25 kDa, and syntaxin-4 in murine melanocytic cells. We also showed that purified melanosome preparations contain rab3a and SNARE, including vesicle-associated membrane protein-2, syntaxin-4, synaptosome-associated proteins 23 kDa and 25 kDa, and the SNARE accessory protein, alpha-soluble N-ethylmaleimide-sensitive factor attachment protein. Ultraviolet radiation is a potent stimulus for melanosome transport and transfer. We show that ultraviolet radiation rapidly suppresses melanosome-associated rab3a expression and that this occurs at the protein and mRNA level. Finally, we show that vesicle-associated membrane protein-2 and synaptosome-associated protein 23 kDa coimmunoprecipitate from purified melanocytic cell membranes, suggesting that they form complexes. The presence of rab3a and SNARE on melanosomes, and of SNARE complexes in melanocytic cell membranes suggests that these proteins play a part in targeting melanosomes to the plasma membrane, to melanosome transfer to keratinocytes, or both.

Animals↗
PubMed2001

Ganglioglioma of the lateral ventricle presenting with blepharospasm - case report and review of the literature.

Gangliogliomas of the lateral ventricle are unusual tumours of the central nervous system. We report a 25-year-old female who presented with a 4-week history of generalized headaches associated with left-sided blepharospasm. Clinical examination revealed bilateral papilloedema but no focal neurological deficits. Computed tomography and magnetic resonance imaging demonstrated a large lesion within the left lateral ventricle. Gross total surgical resection of the lesion was performed through a para-sagittal, trans-callosal approach. Histopathological analysis revealed the diagnosis of ganglioglioma. The post-operative course was uneventful, with complete resolution of both the headaches and blepharospasm. The presentation with an ipsilateral blepharospasm has never previously been reported in the setting of a lateral ventricular tumour.

Adult↗
PubMed2001

"War stories": AIDS prevention and the street narratives of drug users.

The day-to-day discourse of illicit drug users is replete with stylized narratives of street experience. These "war stories," as they are popularly known, are shared among drug users as they hustle for money, purchase drugs, get high, and hang out in diverse street locations. Drug-user narratives, which describe complex adventures and grave suffering, are primary ethnographic sources of information about patterns of drug consumption and risk behaviors. Importantly, in the time of AIDS, street narratives provide a much-needed window on the generally hidden lives of socially marginalized street drug users. As part of an effort to put the analysis of drug-user war stories to use in HIV prevention, in this article the authors analyze a corpus of street narratives told to members of an HIV-prevention research team in Hartford, Connecticut.

Adaptation, Psychological↗
PubMed2001

A study of family carers of people with a life-threatening illness 1: the carers' needs analysis.

This study examines the educational and supportive requirements of carers of people with a life-threatening illness. Responses would indicate the content and format of an educational or supportive programme of material that might then be developed. Twenty-four carers known to a Macmillan team in a national health service trust in the north of England were targeted for participation and quantitative data collected were analysed manually. Qualitative data arising from the carer interviews were subjected to a simple content analysis exercise that led to the identification of some overarching themes. In both strands of the research, similar emergent themes of physical, emotional and social stress were identified. Findings suggest that consideration of carers' age, length of caring experience and gender may be helpful in understanding their experience of stress and in developing support strategies.

Adult↗
PubMed2001

A study of family carers of people with a life-threatening illness. 2: Implications of the needs assessment.

This is the second of two articles that consider the findings of a Carers' Assessment of Difficulties Index (CADI) (Nolan et al, 1998) delivered in a palliative care context. It analyses the implications of these findings for practitioners concerned with the delivery of palliative care to such carers and their families. The development of support strategies and services addressing their needs are also presented against a backdrop of transactional stress theory. For people new to caring, recommendations for the local service include early intervention through informational support and validation of their emotional responses to caring; for longer-term carers they include assistance with cognitive reappraisal of the stressfulness of caring and regular 'respite' and socializing opportunities. These are taking place in a political climate that finally recognizes the contribution and value of carers (Department of Health, 1999). The research behind these carer identity and recognition initiatives aims to apply the spirit of public recognition and practical wisdom of palliative care expertise by responding sensitively to the specific needs of carers of people with a life-threatening illness.

Caregivers↗
PubMed2001

Hepatitis C virus among genitourinary clinic attenders in Scotland: unlinked anonymous testing.

Our objective is to gauge the prevalence of hepatitis C virus (HCV) antibodies among a population at risk of contracting sexually transmitted infections (STIs) and, thus, the efficiency with which the virus is transmitted sexually. The investigators undertook an unlinked anonymous HCV antibody testing study of residual syphilis serology specimens taken from attenders of genitourinary clinics in Glasgow, Edinburgh and Aberdeen during 1996/97. The results were linked to non-identifying risk information. Anti-HCV prevalences among non-injecting heterosexual men and women, and non-injecting homosexual/bisexual males ranged between 0 and 1.2%; the only exception to this was a 7.7% (4/52) prevalence among homosexual/bisexual males in Aberdeen. The overall anti-HCV prevalence for homosexual/bisexual males was 0.6% (4/668), for heterosexual males 0.8% (32/4135), for heterosexual females 0.3% (10/3035) and for injecting drug users 49% (72/148). Only 3 (all female) of the 46 non-injectors who were antibody positive were non-UK nationals or had lived abroad. HCV antibody positive injectors were less likely to have an acute STI and more likely to know their HCV status than non-injectors; no differences in these parameters were found between positive and negative non-injectors on anonymous HCV antibody testing. Our findings are in keeping with the prevailing view that HCV can be acquired through sexual intercourse but, for most people, the probability of this occurring is extremely low. Interventions to prevent the spread of HCV should be targeted mainly at injecting drug user (IDU) populations.

Female↗
PubMed2001

Septo-optic dysplasia and unexpected adult death--an autopsy approach.

A 20-year-old woman who suffered from septo-optic dysplasia died unexpectedly following a presumed viral gastroenteritis. Autopsy and neuropathological examination confirmed optic nerve hypoplasia with absence of the septum pellucidum. Marked adrenal gland hypoplasia reflected hypothalamic hypopituitarism. The small and large intestines were dilated and filled with liquid fecal material. This case demonstrates that individuals with septo-optic dysplasia may be at risk of unexpected death at all ages. The complexity of mechanisms of death in rare dysmorphic conditions may be overlooked if relevant clinical information is not available at the time of autopsy and unless specific steps are taken to clearly delineate the underlying features of the condition.

Adrenal Gland Diseases↗
PubMed2000

The outcome of cemented vs. cementless fixation of a femoral component in total knee replacement (TKR) with the identification of radiological signs for the prediction of failure.

A survival analysis and radiological review were performed on a series of femoral total knee arthroplasty (TKA) prostheses either cemented (150 cases) or cementless, press-fit (201 cases). The internal surface of the femoral components were shot-blast CoCr alloy. The incidence of loosening of the femoral component at 6 years was 9.8% with cementless fixation and 0.6% with cement (P<0.05) at 6 years. Amongst uncemented prostheses, there was no difference in the survival or radiological outcome with the use of a stem as against two condylar pegs. The clinical need for revision may be predicted radiologically 3 years after operation in symptomless patients by noting a change in component position combined with progressive radiolucent lines and osteolysis. Thus, radiological follow-up should be continued for a minimum of 3 years after knee replacement. The use of a stem enabled the detection of radiolucent lines which we believe were missed around prostheses with condylar pegs. Thus, the use of a stem improves the prediction of failure (but does not improve fixation).

Journal Article↗