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Biomedical subjects

C Parsons

Publications and source records attributed to C Parsons.

At least 37 records · Page 2Linked to original sources
PubMed1994

Modulation of fast excitatory synaptic transmission by cyclothiazide and GYKI 52466 in the rat hippocampus.

The effects of cyclothiazide, a drug which potentiates AMPA receptor-mediated responses and GYKI 52466, a non-competitive AMPA receptor antagonist, were studied on fast glutamatergic transmission in rat hippocampal slices. Cyclothiazide prolonged the decay of AMPA receptor-mediated EPSCs (AMPA-EPSCs) in a concentration-dependent manner. GYKI 52466 reduced the peak amplitude of AMPA-EPSCs and blocked the induction of LTP. When GYKI 52466 was applied in the presence of cyclothiazide it still reduced the peak amplitude of AMPA-EPSCs but was not able to reverse the cyclothiazide induced prolongation of AMPA-EPSC duration. These data suggest that GYKI 52466 and cyclothiazide probably mediate their effects on the AMPA receptor via different binding sites.

2-Amino-5-phosphonovalerate↗
PubMed1994

Efficacy of feeding glucosinolate-extracted crambe meal to broiler chicks.

Glucosinolates and their breakdown products (nitriles) have long been implicated as toxic factors when feeding rapeseed (Brassica napus) meals and crambe (Crambe abyssinica) meals to poultry. Accordingly, various methods have been developed to remove these compounds from the meals to enhance their value as feed supplements. Glucosinolates and nitriles were extracted from commercially processed, defatted crambe meal by washing with water or various solvent-water mixtures: 50% isopropanol, 50% acetone, or 50% ethanol. In addition, crambe seed was extruded and extracted in the laboratory with isopropanol or hexane. Water washing of commercially defatted meal proved to be the most effective method of extraction, removing 95% of the glucosinolates and nitriles. Meals were fed to 7-d-old broiler chicks at 10% of the diet for 14 d. Weight gain decreased (P < .05) in most groups; however a greater decrease (P < .01) was observed in birds fed meals with high glucosinolate content. Feed intake also decreased (P < .05) in most groups; consequently, feed efficiencies were similar for all groups. No changes in serum chemistries, triiodothyronine, thyroxine, or tissue lesions were associated with glucosinolate or nitrile intake. A relationship (P < .05, r = .74) was found between weight gain and glucosinolate intake. No correlation was found between feed intake and meal glucosinolate or nitrile concentrations.

Alkenes↗
PubMed1994

Back care in pregnancy.

Early in pregnancy it is useful to encourage the mother to do some gentle exercise to offset some of the mechanical strain that will arise with postural changes. Manipulation of the lumbar spine and pelvic joints is possible until the sixth month for primigravidae and the fourth or fifth month for multiparae. The joints and soft tissues will respond very readily to gentle stretching techniques because of hormonal changes. It is appropriate for midwives to have a good working knowledge of the mechanical advantages and disadvantages of different maternal positions adopted during labour.

Exercise Therapy↗
PubMed1993

Life satisfaction of the home care client.

Improving the quality of life is one of the prime motivations for home care providers, but how much and what kind of improvement does home care actually offer? This research brings up questions that the industry may wish to address.

Aged↗
PubMed1993

Detection of serum hepatitis C virus RNA in HCV antibody-seropositive volunteer blood donors.

Approximately 90% of subjects with chronic hepatitis resulting from hepatitis C virus infection have hepatitis C virus RNA in serum. However, the prevalence of hepatitis C virus RNA in serum from subjects with hepatitis C virus antibody associated with persistent normal liver biochemical values is unclear. Do these subjects have resolved or continuing infection with hepatitis C virus? The aim of this study was to examine whether subjects with hepatitis C virus antibody but normal ALT levels had evidence of ongoing infection. Our study population was divided into four groups. Groups 1, 2 and 3 comprised hepatitis C virus antibody-positive volunteer blood donors. Group 1 was made up of subjects found to be hepatitis C virus antibody-positive on enzyme-linked immunosorbent assay with persistent abnormal ALT levels (59 donors: 53 positive on recombinant immunoblot assay and 6 indeterminate). Group 2 members were hepatitis C virus antibody positive, with persistent normal ALT levels (50 donors: 39 positive on recombinant immunoblot assay and 11 indeterminate). Group 3 members were hepatitis C virus seropositive but negative on second-generation recombinant immunoblot assay (n = 48). Twenty patients (not blood donors) with chronic liver disease who were anti-hepatitis C virus seronegative were used as controls (group 4). Serum samples from all four groups were assayed for hepatitis C virus RNA on reverse transcription and a 40-cycle polymerase chain reaction with a combination of primers from the highly conserved 5'-noncoding and less-conserved third and fourth nonstructural regions. All assays were confirmed on hybridization with an internal probe.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1992

Benign mimics of soft tissue sarcomas.

We reviewed all new patients referred for treatment to the Sarcoma Unit at the Royal Marsden Hospital with a clinical diagnosis of soft tissue sarcoma (STS) during the course of 1 year (1989-1990). Of 118 patients, 65 (55.1%) had primary STS, 26 (22.0%) had recurrent STS, 19 (16.1%) had benign soft tissue tumours and eight (6.8%) had malignant tumours other than STS involving soft tissues and presenting clinically as soft tissue tumours. All patients underwent CT scanning which was used to assist diagnosis, assess operability or for radiotherapy planning. The CT findings of the benign lesions, all clinically suspicious of sarcoma, are discussed. The role of CT in the identification and management of these cases is emphasized.

Arteriovenous Malformations↗
PubMed1992

The role of diagnostic CT scanning of the brachial plexus and axilla in the follow-up of patients with breast cancer.

In order to assess the value of computed tomographic scanning of the axilla and brachial plexus in the management of patients with arm symptoms following treatment for breast cancer, the case notes and diagnostic films of 102 such patients who underwent scanning between 1985 and 1990 at this institution were analysed retrospectively. The clinical indications for requesting computed tomography (CT) of the brachial plexus and axilla included arm oedema (52 patients, 51%), brachial plexus neuropathy (73 patients, 72%), and/or the presence of a palpable axillary mass (18 patients, 18%). Of 102 CT scans, 80 showed either no abnormality (31 patients, 30%), or axillary fibrosis (49 patients, 48%), and 22 (21%) showed radiological evidence of recurrent tumour. Only 4 of 84 patients with no palpable mass had computed tomographic evidence of occult recurrent tumour; all of these had concurrent evidence of distant metastatic disease (lung, liver, bone). Patients have been followed up for from between 1 and 15 years from diagnosis (median 5.5 years). The extremely low yield of tumour recurrence on computed tomographic scanning in the absence of a palpable axillary mass (4/84 patients, 5%; 95% CI 1-12), cannot justify CT as a method of screening for clinically occult axillary relapse in patients with arm symptoms following axillary surgery and radiotherapy for breast cancer. Computed tomographic scanning in these patients should only be employed to confirm the clinical suspicion of tumour as a baseline prior to further treatment.

Axilla↗
PubMed1992

Chest radiography in the management of breast cancer.

This study was undertaken to assess the utility of chest radiography (CXR) in the management of patients with breast cancer and to devise a suitable imaging policy for such patients. A retrospective analysis was performed of the case notes and the CXRs of a series of 141 patients presenting to this hospital in 1980 with a diagnosis of early breast cancer. Data retrieved covered the entire clinical course to date and included the number of CXRs performed for a clinical reason and the number performed as "routine". Correlation of the result of every CXR requested to subsequent therapeutic decision-making throughout the complete clinical course of each patient was undertaken and the proportion of CXRs initiating a management change, or performed for a clinical reason, out of the total requested was assessed. A total of 1161 CXRs were performed on the 141 patients studied. Of these, only 174 (15%) were undertaken for a direct clinical reason and 987 (85%) were undertaken as part of "routine" follow-up procedures and had no impact on patient management. Four "routine" CXRs (< 0.4%) demonstrated previously undiagnosed pulmonary metastases, in patients with no other history of metastatic disease. Thus, routine chest radiography is not a cost-effective method of monitoring asymptomatic patients with breast cancer for metastasis. It is recommended that outside staging procedures for clinical trials, the CXR is used only to address a clinical problem relating specifically to the thorax. It is anticipated that the cessation of all other chest radiography in patients being followed up for breast cancer at this institution will have significant budgetary implications.

Bone Neoplasms↗
PubMed1991

Accuracy of CT in detecting squamous carcinoma metastases in cervical lymph nodes.

The accuracy of computed tomography (CT) in the assessment of nodal metastases was correlated retrospectively with the pathological examination in 28 patients with known head and neck squamous cell carcinoma, who underwent neck dissections. Three patients had bilateral neck dissections resulting in a total of 31 dissections. CT scanning correctly staged 28 of 31 neck dissections providing an accuracy of 90%, a sensitivity of 87.5% and a specificity of 100% in the detection of nodal metastases. Of the 21 true positives, underestimation of the extent of nodal disease occurred in seven cases. Regarding extracapsular nodal spread, CT resulted in an accuracy of 62%, a sensitivity of 62.5% and a specificity of 60%. All three false negatives for nodal metastases occurred in metastatic spread to the submandibular nodes. The existing criteria for assessment of nodal metastases with CT are sensitive and specific, but in the assessment of extranodal spread CT may not detect 37.5% of cases.

Carcinoma, Squamous Cell↗
PubMed1991

Retroconversion of immature teratoma of the ovary: CT appearances.

We have studied seven patients presenting to the Royal Marsden Hospital between 1983 and 1989 with metastatic immature teratoma of the ovary. All patients underwent initial surgery followed by combination chemotherapy and a second laparotomy. Serial CT scans were performed at 2-3 monthly intervals from diagnosis until the second laparotomy, and the results of this were correlated with the CT appearances. In six of the seven patients CT scanning demonstrated 'retroconversion' of immature malignant tumour masses to benign mature disease during treatment. CT features of maturation included increased density of mass lesions, whose margins became better circumscribed in relation to adjacent tissues, and the onset of internal calcification, with fatty areas and cystic change. These changes on CT correlated exactly with normalization of an initially raised serum tumour marker, alpha feto-protein (AFP) in all six patients. The second laparotomy revealed only mature teratoma in all patients following chemotherapy. In three patients show continued growth of the mature deposits necessitated further surgery for local pressure symptoms, but overall, none has shown malignant relapse, and all are currently well between 1 and 6 years after diagnosis. This is the first report of the CT appearances of retroconversion of immature ovarian teratoma in a series of patients, which is an important radiological diagnosis to make in order to avoid confusion with advancing malignancy. A review of the literature is presented.

Adolescent↗
PubMed1991

Lymphography--current role in oncology.

A review of the use of lymphography at this hospital, a major oncology centre, is presented. The advent of computed tomography has brought a dramatic reduction in the number of lymphograms currently performed for diseases such as lymphoma, testicular tumours and gynaecological malignancies. This study analyses the reasons for this decline, and concludes that valuable information can still be obtained from lymphography in certain selected groups of patients.

Female↗
PubMed1991

Focal myositis, a benign inflammatory pseudotumour: CT appearances.

Focal myositis is a rare benign pseudotumour of skeletal muscle, of unknown cause. Clinically it presents as an enlarging mass within muscle, usually of an extremity, and is often mistaken for a soft tissue neoplasm. The diagnosis is made by biopsy which reveals characteristic histological changes of inflammation, focal degeneration and regeneration, and some evidence of denervation. The CT findings include irregularity and enlargement of the muscles involved, with diffuse, poorly defined fatty infiltration of the muscle planes, but no evidence of an associated mass. We present two cases of focal myositis of the calf, both of which mimicked a soft tissue neoplasm, and in which CT was helpful in determining the nature and extent of the abnormality, for needle biopsy, and follow-up.

Adult↗
PubMed1990

Radiation-induced brachial plexus injury: follow-up of two different fractionation schedules.

All 449 breast cancer patients treated with post-operative radiotherapy to the breast and lymph nodes between 1982 and 1984 have been followed for 3-5.5 years. In this group two different fractionation schedules were used, one five times a fortnight and one daily, both over 6 weeks. The calculated dose to the brachial plexus was 45 Gy in 15 fractions or 54 Gy in 30 fractions. These schedules are equivalent doses using the standard NSD formula. The diagnosis of a brachial plexus injury was made clinically and computed tomography was used to distinguish radiation injury from recurrent disease. The actuarial incidence of a radiation-induced brachial plexus injury for the whole group was 4.9% at 5.5 years. No cases were seen in the first 10 months following radiotherapy. The incidence rises between 1 and 4 years and then starts to plateau. When the large fraction size group is compared with the small fraction size group the incidence at 5.5 years is 5.9% and 1.0%, respectively (p = 0.09). Two different treatment techniques were used in this group but were not found to contribute to the probability of developing a brachial plexus injury. It is suggested that radiation using large doses per fraction are less well tolerated by the brachial plexus than small doses per fraction; a commonly used fractionation schedule such as 45 Gy in 15 fractions may give unacceptably high brachial plexus morbidity; and the use of small doses per fraction or avoiding lymphatic irradiation is advocated.

Brachial Plexus↗
PubMed1990

CT scanning in patients following surgery on the tongue and floor of mouth.

Computed tomographic (CT) scanning was performed on 15 patients who had undergone carefully documented major surgery for malignancy to the tongue and floor of mouth in order to assess appearances of the face and neck following extensive resection. The appearances following a variety of operations, often with reconstruction, were identified. Familiarity with the normal post-operative anatomy allows the recognition of small volume recurrent tumour and the implementation of appropriate treatment.

Humans↗
PubMed1990

Assessment of intestinal amino acid availability in cattle by use of the precision-fed cecectomized rooster assay.

The digestibilities of amino acids in duodenal digesta of steers were measured using a precision-fed cecectomized rooster assay. Freeze-dried duodenal digesta from steers fed five different diets were utilized. Amino acids present in digesta of steers fed diets supplemented with corn gluten meal were more digestible than those from digesta of steers fed diets supplemented with soybean meal, blood meal, fish meal, or no true protein source. Measurements of amino acid digestibility in the cecectomized rooster were similar to those obtained previously when measured with reference to chromic oxide in steers fitted with duodenal and ileal cannulae, suggesting that the precision-fed cecectomized rooster assay is an appropriate technique for estimating small intestinal digestibility of amino acids in cattle.

Amino Acids↗