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Biomedical subjects

S Hammond

Publications and source records attributed to S Hammond.

At least 37 records · Page 2Linked to original sources
PubMed1999

[Fatigue in the healthy and in cancer patients. II. A qualitative study for conceptual analysis].

A qualitative study to explore the concept of fatigue/tiredness in cancer patients and in healthy individuals Interest in fatigue-research has grown since the finding that fatigue/tiredness is the most frequently reported symptom of cancer and its treatment. But even though several authors have tried to conceptualise fatigue its mechanisms are still poorly understood. The aim of this study was twofold: 1. to explore fatigue in cancer patients, inductively, and 2. to compare experiences of fatigue/tiredness of healthy individuals with that of cancer patients to identify cancer-specific fatigue/tiredness and related concepts. A qualitative research strategy was adopted using a grounded theory approach. The prospective study took place in the Oncology Department of the Kantonsspital St. Gallen (Switzerland) with samples of 20 cancer patients and 20 healthy individuals. Unstructured, tape recorded interviews were conducted to collect data. The transcripts of the interviews were analysed using content analysis and constant comparison. Different themes emerged between the two groups although both fitted a classification system, which categorised fatigue into physical, affective and cognitive expressions of fatigue/tiredness. Physical signs were more frequent than affective and cognitive signs in both groups. In the cancer patients, fatigue involved decreased physical performance, extreme, unusual tiredness, weakness and unusual need for rest, which was distinctly different for healthy persons. Affective and cognitive distress was also more prominent in cancer patients. Interestingly, the concept of malaise was not identified by either sample and not understood as an expression of fatigue by this German speaking population. Linguistic differences in the description of fatigue/tiredness between healthy and ill individuals revealed different perceptions of the phenomenon. A step-like theory, explaining the production of fatigue/tiredness was tentatively put forward involving nociception, perception and expression of tiredness. The emerging concepts break tiredness/fatigue into expression of physical, affective and cognitive tiredness/fatigue. The experience is different between healthy individuals and cancer patients. Generalisability of data needs precaution but the results of the study identifies and clarifies ideas that might form an important basis for further, controlled studies.

Activities of Daily Living↗
PubMed1999

Atypical presentation of Clostridium difficile colitis in patients with cystic fibrosis.

OBJECTIVE: This report describes the unusual presentation of Clostridium difficile colitis in five patients with cystic fibrosis and the role of CT in first suggesting the correct diagnosis in this group of patients. Because of the absence of watery diarrhea and the presence of abdominal bloating and decreased stooling, cystic fibrosis patients with C. difficile colitis will be treated for stool impaction, meconium ileus equivalent, or distal intestinal obstruction syndrome. CT of the abdomen, performed in these five patients because of their lack of improvement after standard therapy for stool impaction, showed an extensive pancolitis later confirmed to be caused by C. difficile infection. CONCLUSION: In patients with cystic fibrosis, imaging findings of a pancolitis should raise the possibility of C. difficile colitis despite the lack of watery diarrhea. Anticlostridial treatment can be initiated before bacteriologic confirmation is obtained.

Adult↗
PubMed1998

Nonteratomatous germ cell tumors in children.

BACKGROUND/PURPOSE: Totipotential germ cells may give rise to a broad range of tumors. The teratomatous variety of germ cell tumors has been the subject of several large studies. The goal of the current study was to describe the clinical features of nonteratomatous germ cell tumors (NTGCT) by reviewing a large series of patients. METHODS: Between 1945 and 1997, there were 78 cases of nonteratomatous germ cell tumors (NTGCT's) in children at The Children's Hospital, Columbus. Their records were reviewed retrospectively. There were 35 boys and 43 girls (M:F ratio 0.8). Mean follow-up was 87 months. RESULTS: Histological subtypes included germinoma (33 cases, 42%), endodermal sinus tumor (24 cases, 31%), embryonal carcinoma (12 cases, 15%), gonadoblastoma (4 cases, 5%), mixed histology (4 cases, 5%), and choriocarcinoma (1 case, 2%). Forty-two tumors were in gonadal sites, but a significant percentage were extragonadal (36 cases, 46%). Forty-six patients (59%) had localized disease, 18 (23%) had regional disease, and 14 (18%) had metastases. Treatment consisted of surgery and selective chemotherapy and radiation. Complete tumor resection was more likely for gonadal (29 of 42, 69%) than extragonadal primaries (15 of 36, 41%; P < or = .05). Forty-nine (63%) of all patients survived, whereas 29 (37%) died of their disease. Survival in patients with gonadal primaries (32 of 42, 76%) exceeded that in patients with extragonadal primaries (17 of 36, 47%; P < or = .01). Survival in patients with localized disease (34 of 46, 74%) exceeded that in patients with regional extension or metastases (15 of 32, 47%; P < .05). CONCLUSIONS: This study highlights the fact that tumor location, gonadal versus extragonadal, was important in determining prognosis, whereas tumor histology was not. This may be the result of a higher rate of complete tumor resection for gonadal primaries and underscores the important role of surgery in the optimal treatment of these unusual tumors.

Adolescent↗
PubMed1998

Using "stages of behavioral change" constructs to measure the short-term effects of a worksite-based intervention to increase moderate physical activity.

We evaluated a three-level incentive program to promote regular, moderate physical activity among employees working in a federal agency. The objective was to assess the short-term effects of the intervention by examining the stages people go through as they attempt to make permanent changes in physical activity. Indicators of the process by which changes in physical activity take place were based on a modified version of the Transtheoretical Model of Behavior. A one-group pretest/posttest design was used to ascertain which of the stages the 1,192 participants were in both before and after the intervention. Analysis indicated that, of the 1,192 participants, 6.5% regressed one or more stages, 30.3% did not regress or progress from one stage to another, 27.7% remained in the maintenance stage, and 35.4% progressed one (21.1%) or more (14.3%) stages during the 50-day intervention. Among those who progressed, the most common change was from preparation to late preparation (20.8%) and from late preparation to action (19.4%). Findings reinforce the notion that the stages of change concept can serve as indicators of the change process which in turn, can be used as evidence of the short-term effectiveness of interventions. Findings also indicate this type of intervention holds promise for increasing physical activity among willing participants of a worksite population.

Behavior Therapy↗
PubMed1997

Acute pulmonary toxicity in an infant from intravenous amiodarone.

Intravenous amiodarone is an effective treatment for supraventricular and ventricular tachyarrhythmias. We report a case of acute pulmonary toxicity in an infant from intravenous amiodarone and describe the clinical evaluation and laboratory studies leading to the diagnosis.

Acute Disease↗
PubMed1997

Can the histologic changes of cystic fibrosis-associated hepatobiliary disease be predicted by clinical criteria?

BACKGROUND: Correlation between clinical parameters and histology changes in cystic fibrosis liver disease has not been documented. The purpose of this study was to determine the histologic spectrum of cystic fibrosis liver disease and the degree to which a clinical scoring system can identify subjects with significant histologic abnormalities. METHODS: We reviewed the predictive value of physical examination, biochemical parameters, and a clinical liver score, incorporating physical examination and biochemical parameters, in predicting significant abnormalities of liver histology in 43 cystic fibrosis patients who underwent hepatic biopsy. Biopsies were scored by two masked pathologists for fibrosis, inflammation, inspissation, fatty infiltration, and congestion. RESULTS: Significant histologic disease was present in 56% of patients despite little biochemical or physical examination evidence of disease. No single parameter used in the scoring system predicted the type or degree of the liver disease. The clinical liver score had a sensitivity of 85% and a specificity of 82% in predicting significant histologic changes, yet it was unable to predict the specific lesion. CONCLUSIONS: Significant histologic liver disease is common in cystic fibrosis, although the exact nature of the lesion cannot be predicted without liver biopsy. A clinical liver score that was developed for this may be useful in determining which patients require more definitive evaluation.

Adolescent↗
PubMed1997

Randomized trial of chemotherapy and radiation therapy with or without warfarin for limited-stage small-cell lung cancer: a Cancer and Leukemia Group B study.

PURPOSE: Studies by the Veterans Administration Cooperative Studies Program and Cancer and Leukemia Group B (CALGB) suggested that the addition of warfarin to chemotherapy might enhance response and/or survival in small-cell lung cancer (SCLC). This randomized study evaluated the effect of warfarin with chemotherapy and radiation therapy in limited-stage SCLC. PATIENTS AND METHODS: Patients were randomized to receive warfarin or no warfarin. All patients received three cycles of doxorubicin, cyclophosphamide, and etoposide (ACE). Cycles 4 and 5 (cisplatin, cyclophosphamide, and etoposide [PCE]) were given concurrently with radiation therapy. Three cycles of ACE were given after chemoradiation therapy, but were discontinued due to a high rate of pulmonary toxicity. RESULTS: There were no significant differences in response rates, survival, failure-free survival, disease-free survival, or patterns of relapse between the warfarin-treated and control groups. In patients treated according to the initial design, an increase in failure-free survival seen with warfarin treatment approached significance (P = .07). Preamendment results, while not significant, did not have superimposable treatment survival curves. A landmark analysis at 8 months showed a median survival time after the landmark for complete responders of 33 months with warfarin treatment compared with < or = 13.75 months for complete or partial responders not treated with warfarin (P = .05). Differences between the complete responders in this preamendment population were not significant (P = .103). CONCLUSION: Warfarin does not appear to improve outcome significantly in limited-stage SCLC. However, the differences in some variables between populations before the protocol amendment correspond to the favorable effects of anticoagulants observed in previous studies.

Adult↗
PubMed1996

A qualitative study to explore the concept of fatigue/tiredness in cancer patients and in healthy individuals.

Interest in fatigue research has grown since the finding that fatigue/tiredness is the most frequently reported symptom of cancer and its treatment. But even though several authors have tried to conceptualise fatigue, its mechanisms are still poorly understood. The aim of this study was twofold: (a) to explore fatigue in cancer patients inductively, and (b) to compare experiences of fatigue/tiredness of healthy individuals with those of cancer patients to identify cancer-specific fatigue/tiredness and related concepts. A qualitative research strategy was adopted using a grounded-theory approach. The prospective study took place in the oncology department of the Kantonsspital, St. Gallen, Switzerland, with samples of 20 cancer patients and 20 healthy individuals. Unstructured, tape-recorded interviews were conducted to collect data. The transcripts of the interviews were analysed using content analysis and constant comparison. Different themes emerged between the two groups although both fitted a classification system that categorised fatigue into physical, affective and cognitive expressions of fatigue/tiredness. Physical signs were more frequent than affective and cognitive signs in both groups. In the cancer patients, fatigue involved decreased physical performance, extreme, unusual tiredness, weakness and an unusual need for rest, which was distinctly different for healthy persons. Affective and cognitive distress was also more prominent in cancer patients. Interestingly, the concept of malaise was not identified by either sample and not understood as an expression of fatigue by this German-speaking population. Linguistic differences in the description of fatigue/tiredness between healthy and ill individuals revealed different perceptions of the phenomenon. A step-like theory, explaining the production of fatigue/tiredness was tentatively put forward involving nociception, perception and expression of tiredness. The emerging concepts break tiredness/fatigue into an expression of physical, affective and cognitive tiredness/fatigue. The experience is different between healthy individuals and cancer patients. Care must be taken when drawing generalised conclusions but the results of the study identify and clarify ideas that might form an important basis for further, controlled studies.

Adult↗
PubMed1996

Beta subunits promote K+ channel surface expression through effects early in biosynthesis.

Voltage-gated K+ channels are protein complexes composed of ion-conducting integral membrane alpha subunits and cytoplasmic beta subunits. Here, we show that, in transfected mammalian cells, the predominant beta subunit isoform in brain, Kv beta 2, associates with the Kv1.2 alpha subunit early in channel biosynthesis and that Kv beta 2 exerts multiple chaperone-like effects on associated Kv1.2 including promotion of cotranslational N-linked glycosylation of the nascent Kv1.2 polypeptide, increased stability of Kv beta 2/Kv1.2 complexes, and increased efficiency of cell surface expression of Kv1.2. Taken together, these results indicate that while some cytoplasmic K+ channel beta subunits affect the inactivation kinetics of alpha subunits, a more general, and perhaps more fundamental, role is to mediate the biosynthetic maturation and surface expression of voltage-gated K+ channel complexes. These findings provide a molecular basis for recent genetic studies indicating that beta subunits are key determinants of neuronal excitability.

Animals↗
PubMed1996

A qualitative study to explore the concept of fatigue/tiredness in cancer patients and in healthy individuals.

Interest in fatigue research has grown since the finding that fatigue/tiredness is the most frequently reported symptom of cancer and its treatment. But even though several authors have tried to conceptualize fatigue (Piper & Rieger, 1989; Cimprich, 1992; Gibson & Edwards, 1985; Winningham, 1994; Irvine et al. 1994; Grandjean, 1970; et al.), its mechanisms are still poorly understood. The aim of this study was two-fold: i) to explore fatigue in cancer patients, inductively, and ii) to compare fatigue/tiredness experiences of healthy individuals with those of cancer patients to identify cancer-specific fatigue/tiredness and related concepts. A qualitative research strategy was adopted using a grounded-theory approach. The prospective study took place in the Oncology Department of the Kantonsspital St Gallen (Switzerland) with samples of 20 cancer patients and 20 healthy individuals. Unstructured, tape-recorded interviews were conducted to collect data. Transcripts of the interviews were analysed using content analysis and constant comparison. Although different themes emerged between the two groups, both fitted a classification system that categorized expression of fatigue/tiredness as physical, affective or cognitive. Physical signs were more frequent than affective and cognitive signs in both groups. For the cancer patients, fatigue involved decreased physical performance, extreme, unusual tiredness, weakness and an unusual need for rest, which was distinctly different for healthy persons. Affective and cognitive distress were also more prominent in cancer patients. Interestingly, the concept of malaise was not identified by either sample and not understood as an expression of fatigue by this German-speaking population. Linguistic differences in the description of fatigue/tiredness between healthy and ill individuals revealed different perceptions of the phenomenon. A step-like theory, involving nociception, perception and expression of tiredness, was put forward tentatively to explain the production of fatigue/tiredness. The emerging concepts break tiredness/fatigue into expressions of physical, affective and cognitive tiredness/fatigue. The experience is different between healthy individuals and cancer patients. The generalization of data needs precaution but the results of the study identify and clarify ideas that might form an important basis for further, controlled studies.

Adult↗
PubMed1996

Comparison of radiographer/radiologist double film reading with single reading in breast cancer screening.

OBJECTIVES - To assess the efficacy of dual film reading in screening mammography with a suitably trained radiographer as the second reader and to determine a suitable decision model for radiographer/radiologist double reading. SETTING - Three breast screening centres in South Thames (West) region. METHODS - Seven radiographers with prior film reading training double read 17 202 screening mammograms with a radiologist. Screening performance of radiographers and radiologists was assessed taking into account interval cancers. The efficacy of radiographer/radiologist double reading was assessed in terms of changes in sensitivity and specificity compared with radiologist single reading. RESULTS - Radiographers yielded equivalent sensitivity but lower specificity than radiologist film readers. The effect of double reading between radiographer/radiologist pairs was an increase in sensitivity of 6-4%, which was achieved at the cost of a 0-6% decrease in specificity. This was reached by a decision system involving radiologists' review of radiographer queries and recall classifications. If all radiographer queries were recalled a large increase in sensitivity would be counterbalanced by an equally large decrease in specificity. CONCLUSIONS - Radiographer/radiologist double reading resulted in similar increases in sensitivity as those previously reported in radiologist double reading studies. Radiologist review of radiographer reported abnormalities is a suitable means by which to limit excess recall.

Adult↗
PubMed1996

Radiographers as film readers in screening mammography: an assessment of competence under test and screening conditions.

The aim of this study was to investigate the potential of radiographers as film readers in screening mammography. Seven radiographers received training in mammogram interpretation at a National Health Service (NHS) Breast Screening Training Centre. Film reading performance was assessed over a period of 1 year after training with test sets of selected screening mammograms. Actual screening performance on contemporary screening mammograms was monitored after training in relation to radiologist decisions and screening outcome. It was found that trained radiographers read mammograms to a standard comparable with that of radiologists. Film reading skills were maintained consistently over the period of this study and transferred to actual screening performance. It was concluded that radiographers could play a useful role as second readers in screening mammography. Training needs have to be assessed in relation to the role the film reading radiographer is to adopt.

Adult↗
PubMed1992

Memory impairment in schizophrenia: its extent, affiliations and neuropsychological character.

In a sample of 60 schizophrenic patients encompassing all grades of severity and chronicity memory impairment was found to be prevalent, often substantial, and disproportionate to the overall level of intellectual impairment. The deficits were not easily attributable to poor cooperation, attention or motivation; nor were they related to neuroleptic or anticholinergic medication. Memory impairment was significantly associated with severity and chronicity of illness and also with negative symptoms and formal thought disorder. There was evidence from the sample as a whole, and from a more detailed examination of five patients with relatively isolated deficits, that schizophrenic memory impairment conformed to the pattern seen in the classical amnesic syndrome. Additionally, there was preliminary evidence for a marked deficit in semantic memory.

Adult↗
PubMed1992

Transient chloride binding as a contributory factor to corneal stromal swelling in the ox.

1. Investigations were made of the cation exchange capacity of fresh isolated ox corneal stroma (Q, units: mequiv fixed stromal charge/kg stromal fluid) at pH 7.4 over a variety of stomal hydrations (H, units: kg stromal fluid/kg dry tissue) both above and below the physiological hydration of 3.2, whilst the stromas were immersed in a variety of sodium chloride solutions (range 5-1000 mM). 2. At any particular salt concentration, the product QH (dry tissue exchange capacity, units: mequiv/kg dry tissue) appeared constant, over all the hydrations investigated. 3. Dry tissue exchange capacity (QH) varied, however, when the bathing salt concentration was altered. It varied between 55 mequiv/kg dry tissue (e.g. Q = 17 mequiv at H = 3.2) in 5 mM-NaCl to 240 mequiv/kg dry tissue (e.g. Q = 75 mequiv/l at H = 3.2) in 1000 mM-NaCl. 4. The variation of stromal exchange capacity in NaCl solutions of different concentrations was similar when detected by three independent procedures: stromal gel pressure measurements, intrastromal sodium ion distributions, and intrastromal electrical potentials. 5. Intrastromal chloride ion distributions were anomalous. Total chloride (measured by radio-isotopes) was consistently higher than that predicted by Donnan theory. 6. The data were consistent with Elliott's hypothesis that a fraction of intrastromal chloride ions bind to the corneal stromal matrix and in so doing contribute to the fixed negative charge of the stroma. 7. Our observations may be explained by a model of the cation exchange capacity of ox cornea which has two types of components. On is (at constant pH) invariant, and has a dry tissue exchange capacity of about 50 mequiv/kg dry tissue, and is probably generated by the sulphonic and carboxylic acid groups of the glycosaminoglycans. The other is explained by supposing it to consist of a chloride binding ligand which exhibits first order binding, is half occupied at ambient chloride concentrations of 300 mM, and has a total capacity of 240 mequiv/kg dry tissue. 8. Partial stromal extraction with 4 M-guanidine HCl indicated that the chloride binding ligand is not associated with the collagen molecules in the corneal stromal fibrils. 9. It is suggested that such a stromal chloride ion binding ligand would help to stabilize the hydration and transparency of the living cornea when it is exposed to environments of varying tonicity (such as in river or sea bathing).

Animals↗
PubMed1990

Amnesic syndrome in schizophrenia.

Memory impairment is not usually considered to form part of the clinical picture of schizophrenia, except perhaps in severely deteriorated patients. In a survey of 60 patients encompassing all grades of severity and chronicity poor memory performance was found to be common, sometimes substantial, and disproportionately pronounced compared to the degree of general intellectual impairment. Although associated with severity and chronicity of illness, impaired memory was by no means confined to old, institutionalized, or markedly deteriorated patients. The pattern of deficit appeared to resemble that of the classic amnesic syndrome rather than that seen in Alzheimer-type dementia.

Adolescent↗
PubMed1988

In situ DNA hybridization for cytomegalovirus in colonoscopic biopsies.

We reviewed colonoscopic biopsies of the lower gastrointestinal tract performed during a two-year period. Those representing neoplasia were excluded. Formalin-fixed paraffin-embedded biopsy specimens from 53 patients were studied by in situ DNA hybridization for cytomegalovirus (CMV) using commercially available biotinylated DNA probes detected by an avidin-biotin peroxidase technique. Nine of the patients were severely immunocompromised: four had acquired immunodeficiency syndrome, three had ulcerative colitis and were receiving high-dose steroid therapy, one was a bone marrow transplant recipient, and one had idiopathic pulmonary fibrosis and was receiving therapy with prednisone and cyclophosphamide. Four of these had evidence of CMV infection by routine histology and DNA hybridization. Three additional immunocompromised patients had evidence of CMV infection by DNA hybridization alone. Forty-four patients had inflammatory conditions or ulcerations of the lower gastrointestinal tract. Six of these had evidence of CMV by DNA hybridization alone. Histologically normal as well as enlarged and cytomegalic cells were probe positive, and the cells were sparse to numerous in number. They were found in the epithelium and/or lamina propria. This technique was demonstrated to be applicable to routinely processed colonic biopsy specimens.

Adult↗
PubMed1987

15N and 1H NMR evidence for multiple conformations of the complex of dihydrofolate reductase with its substrate, folate.

The binding of folate to Lactobacillus casei dihydrofolate reductase in the presence and absence of NADP+ has been studied by 15N NMR, using [5-15N]folate. In the presence of NADP+, three separate signals were observed for the single 15N atom, in agreement with our earlier evidence from 1H and 13C NMR for multiple conformations of this complex [(1982) Biochemistry 21, 5831-5838]. The 15N spectra of the binary enzyme-folate complex provide evidence for the first time that this complex also exists in at least two conformational states. This is confirmed by the observation of two separate resonances for the 7-proton of bound folate, located by two-dimensional exchange spectroscopy.

Bacterial Proteins↗