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Biomedical subjects

G V Thomas

Publications and source records attributed to G V Thomas.

At least 19 recordsLinked to original sources
PubMed2006

Multidisciplinary team management is associated with improved outcomes after surgery for esophageal cancer.

We aim to compare the outcomes of patients undergoing R0 esophagectomy by a multidisciplinary team (MDT) with outcomes after surgery alone performed by surgeons working independently in a UK cancer unit. An historical control group of 77 consecutive patients diagnosed with esophageal cancer and undergoing surgery with curative intent by six general surgeons between 1991 and 1997 (54 R0 esophagectomies) were compared with a group of 67 consecutive patients managed by the MDT between 1998 and 2003 (53 R0 esophagectomies, 26 patients received multimodal therapy). The proportion of patients undergoing open and closed laparotomy and thoracotomy decreased from 21% and 5%, respectively, in control patients, to 13% and 0% in MDT patients (chi2 = 11.90, DF = 1, P = 0.001; chi2 = 5.45, DF = 1, P = 0.02 respectively). MDT patients had lower operative mortality (5.7%vs. 26%; chi2 = 8.22, DF = 1, P = 0.004) than control patients, and were more likely to survive 5 years (52%vs. 10%, chi2 = 15.05, P = 0.0001). In a multivariate analysis, MDT management (HR = 0.337, 95% CI = 0.201-0.564, P < 0.001), lymph node metastases (HR = 1.728, 95% CI = 1.070-2.792, P = 0.025), and American Society of Anesthesiologists grade (HR = 2.207, 95% CI = 1.412-3.450, P = 0.001) were independently associated with duration of survival. Multidisciplinary team management and surgical subspecialization improved outcomes after surgery significantly for patients diagnosed with esophageal cancer.

Adenocarcinoma↗
PubMed2004

Comparison of special interest computed tomography, endosonography and histopathological stage of oesophageal cancer.

AIMS: To assess the strength of agreement between the perceived pre-operative stage of oesophageal tumours as determined by spiral computed tomography (CT) and endoscopic ultrasound (EUS), both alone and in combination, with the histopathological stage. METHODS: Sixty patients with oesophageal cancer underwent both pre-operative CT and EUS performed by two consultant radiologists with a special interest in upper gastrointestinal radiology. The strength of the agreement between the radiological stage and the histopathological stage was determined by means of the weighted Kappa statistic (Kw). RESULTS: Sensitivity for T and N stages was 58% and 79% for CT, and 72% and 91% for EUS. Specificity for T and N stages was 80% and 84% for CT, and 85% and 68% for EUS. Kw for T and N stages was 0.455 (p=0.0001) and 0.603 (p=0.0001) for CT compared with 0.604 (p=0.0001) and 0.610 (p=0.0001) for EUS. In patients when CT and EUS agreed regarding the T and N stages, the strength of agreement between the radiological and the histopathological stage was greater (Kw T 0.613 (p=0.0001), Kw N 0.781 (p=0.0001)). CONCLUSION: CT and EUS are complimentary techniques for the staging of oesophageal tumours, and these results reinforce the importance of specialist radiology in stage directed management.

Adenocarcinoma↗
PubMed2003

Illumination of x-rays: the usual lights exposed.

AIMS: Faced with pressure of work and limited resource, doctors frequently use the nearest available light to examine x-ray films. The aim of this study was to examine the relative intensities of hospital light sources, and to compare these with the light intensity guidelines (1500 to 3000 candelas) of the British Institute of Radiology. METHODS: The relative intensities of seven hospital light sources were examined using a standard light meter at a constant 30 cm from the source. A control group of 10 individual consultant's x-ray viewing boxes were compared with six other ward based light sources. RESULTS: Only two light sources approached the British Institute of Radiology light intensity x-ray viewing criteria: the x-ray viewing boxes of consultant radiologists with a median light intensity of 3503 candelas (chi(2)=13.3, df 1; p=0.0001), and daylight from north facing windows with a median of 1464 candelas when overcast (chi(2)=8.571, df 1; p=0.003) and 4669 candelas in sunshine (chi(2)= 6.364, df 1; p=0.0001). CONCLUSION: Few hospital light sources met the British Institute of Radiology guidelines. The long held high regard of artists for northern light appears justified even in the environment of a British district general hospital.

Humans↗
PubMed2002

Special interest radiology improves the perceived preoperative stage of gastric cancer.

AIM: The aim of this study was to compare the accuracy of spiral computed tomography (CT) performed by a specialist radiologist within a multi disciplinary team (MDT) framework with that of radiologists working outside of this framework. MATERIALS AND METHODS: One hundred and ten patients [median age 70 (35-86)yr, 71m] underwent either a preoperative CT performed by the MDT specialist consultant radiologist (n=60) or a CT performed by one of 13 other consultant radiologists (n=50). The strength of the agreement between the CT stage and the histopathological stage was determined by the weighted Kappa statistic (Kw). RESULTS: Sensitivity for T, N and M stage were 64%, 65% and 25% for MDT specialist CT, compared with 24%, 24% and 5% for control CT. Specificity for T, N and M stage were 68%, 59% and 95% for MDT specialist CT compared with 79%, 94% and 93% for control CT. Kw for T, N and M stage were 0.314, 0.350 and 0.255 for MDT specialist CT compared with 0.088, 0.102 and -0.019 for control CT. Unsuspected metastases were found in 12 patients staged by MDT specialist CT compared with 19 patients staged by control CT (Chi2=4.366, df=1,p =0.037). CONCLUSION: Improved patient selection for surgery should maximize use of limited resource.

Adenocarcinoma↗
PubMed2001

Prostate stem cell antigen is overexpressed in human transitional cell carcinoma.

Prostate stem cell antigen (PSCA), a homologue of the Ly-6/Thy-1 family of cell surface antigens, is expressed by a majority of human prostate cancers and is a promising target for prostate cancer immunotherapy. In addition to its expression in normal and malignant prostate, we recently reported that PSCA is expressed at low levels in the transitional epithelium of normal bladder. In the present study, we compared the expression of PSCA in normal and malignant urothelial tissues to assess its potential as an immunotherapeutic target in transitional cell carcinoma (TCC). Immunohistochemical analysis of PSCA protein expression was performed on tissue sections from 32 normal bladder specimens, as well as 11 cases of low-grade transitional cell dysplasia, 21 cases of carcinoma in situ (CIS), 38 superficial transitional cell tumors (STCC, stages T(a)-T(1)), 65 muscle-invasive TCCs (ITCCs, stages T(2)-T(4)), and 7 bladder cancer metastases. The level of PSCA protein expression was scored semiquantitatively by assessing both the intensity and frequency (i.e., percentage of positive tumor cells) of staining. We also examined PSCA mRNA expression in a representative sample of normal and malignant human transitional cell tissues. In normal bladder, PSCA immunostaining was weak and confined almost exclusively to the superficial umbrella cell layer. Staining in CIS and STCC was more intense and uniform than that seen in normal bladder epithelium (P < 0.001), with staining detected in 21 (100%) of 21 cases of CIS and 37 (97%) of 38 superficial tumors. PSCA protein was also detected in 42 (65%) of 65 of muscle-invasive and 4 (57%) of 7 metastatic cancers, with the highest levels of PSCA expression (i.e., moderate-strong staining in >50% of tumor cells) seen in 32% of invasive and 43% of metastatic samples. Higher levels of PSCA expression correlated with increasing tumor grade for both STCCs and ITCCs (P < 0.001). Northern blot analysis confirmed the immunohistochemical data, showing a dramatic increase in PSCA mRNA expression in two of five muscle-invasive transitional cell tumors when compared with normal samples. Confocal microscopy demonstrated that PSCA expression in TCC is confined to the cell surface. These data demonstrate that PSCA is overexpressed in a majority of human TCCs, particularly CIS and superficial tumors, and may be a useful target for bladder cancer diagnosis and therapy.

Antigens, Neoplasm↗
PubMed2001

Effects of drawing on children's item recall.

In four experiments, we used item recall tasks to investigate recent claims that young children's event recall can be facilitated by drawing. In Experiments 1 to 3, children of ages 5 to 8 years were tested 4 h after presentation for recall of a set of 25 items that had been presented in groups on a colored, segmented board. In Experiment 1, recall was enhanced by replacement of the objects on the board as they were recalled, but not by drawing them. In Experiments 2 and 3, drawing the board and objects concurrently with or just prior to verbal recall not only failed to facilitate recall, but significantly reduced the number of items reported by 5- to 6-year-olds. In Experiment 4, drawing again impaired recall of items that had been presented as paired associates. Overall, results indicate that under some conditions drawing can impair children's recall rather than facilitate it, as reported in several recent studies.

Child↗
PubMed2000

Preoperative prostate needle biopsy p27 correlates with subsequent radical prostatectomy p27, Gleason grade and pathological stage.

PURPOSE: Loss of p27 protein expression in radical prostatectomy specimens has been shown to be an adverse prognostic factor in patients with clinically localized prostate cancer. To our knowledge no studies have examined p27 expression in prostate needle biopsies. To test the potential predictive power of p27 in prostate biopsies we compared p27 expression in preoperative biopsies and matched prostatectomy specimens of patients with clinically localized prostate cancer. MATERIALS AND METHODS: Matched biopsies and radical prostatectomy specimens from 44 patients were examined. Mean followup was 22.7 months (range 1 to 46). Tumors expressing less than 30% positive nuclei were classified as low expressors and tumors expressing greater than 30% positive nuclei were classified as high expressors of p27 protein. RESULTS: Expression of p27 in prostate biopsies correlated significantly with subsequent p27 expression in radical prostatectomy specimens (p = 0.002). Sensitivity and specificity of biopsy p27 for predicting subsequent prostatectomy p27 were 87.5% and 88.9%, respectively (p <0.001). Univariate analysis showed that low expression of p27 in the biopsy correlated significantly with biopsy and prostatectomy Gleason score (p = 0.000 and 0.001, respectively), and final pathological stage (p = 0.028). Despite the small sample size and short followup, 36.4% of patients with low p27 expression had a biochemical recurrence compared to only 12.1% with high expression (hazards ratio 3.56). In addition, Kaplan-Meier analysis suggested that low p27 expression in prostate biopsies may be associated with a shorter time to recurrence, although this did not reach statistical significance (p = 0.081). CONCLUSIONS: Expression of p27 in prostate biopsies can be used to predict the degree of expression in radical prostatectomy specimens. As loss of p27 protein expression in prostatectomy specimens has been shown to correlate with biochemical recurrence and shortened prostate specific survival, these results suggest that biopsy p27 may help identify high risk patients preoperatively.

Adult↗
PubMed1999

Realist errors in children's responses to pictures and words as representations.

In three experiments we examined the judgments made by 3- to 4- year-old children about out-of-date physical representations which no longer matched their referents. The referent was a doll wearing a sticker, and the sticker was swapped for a different one after a picture had been drawn of the initial state of affairs (Experiments 1 and 2) or after the name of the doll and its original sticker had been written down (Experiment 3). We confirmed previous findings of realist errors in identity judgments for pictures and showed also that children tended to misidentify the name of a sticker in a written list to match a change to its referent. Thus, realist errors are not confined to representations which are iconically similar to their referents. Furthermore, children also judged incorrectly that the pictures and words had actually been changed, indicating that realist errors to external representations extend to operations performed on their referents as well as to their identities.

Child Language↗
PubMed1998

Down-regulation of p27 is associated with development of colorectal adenocarcinoma metastases.

The cyclin-dependent kinase inhibitor p27 is a negative regulator of the cell cycle and a potential tumor suppressor gene. Because we had previously demonstrated that loss of p27 protein is associated with aggressive behavior in colorectal adenocarcinomas, we used immunohistochemistry and in situ hybridization to evaluate the potential role of alterations in p27 expression in primary and metastatic colorectal adenocarcinomas. Parallel immunostaining was performed for Ki-67 and p53. We evaluated 13 cases of metachronous and 23 cases of synchronous primary and metastatic colorectal tumor pairs. In the synchronous subgroup (Stage IV tumors), 57% of the primary tumor and metastases pairs did not express p27 protein and the remainder were low expressors. In the metachronous subgroup, 54% of the primary tumors were low expressors and the remainder high expressors of p27 protein. There was a significant reduction in the expression of p27 in the metachronous metastases (mean positive cells: 14.5%) when compared to the corresponding primary tumors (mean positive cells: 41.8%), P = 0.0023. All the primary and metastatic tumors in the metachronous subgroup showed high levels of p27 mRNA expression. There was no association between loss of p27 and either Ki-67 count or p53 expression. Because p27 is known to be up-regulated when epithelial cells are grown in suspension, the down-regulation of p27 in circulating tumor cells may confer the ability to grow in an environment of altered extracellular matrix or intercellular adhesion properties, two situations which may facilitate metastases.

Adenocarcinoma↗
PubMed1998

Drawing conclusions: a re-examination of empirical and conceptual bases for psychological evaluation of children from their drawings.

PURPOSE: Although consideration of children's art work (usually drawings) in clinical investigations of children referred to psychologists is fairly common, there is little evidence for the reliability and validity of such assessments. We consider a variety of possible mechanisms which could operate to influence the characteristics of children's drawings, and review the evidence that such mechanisms operate to allow meaningful psychological evaluations of children from their drawings. METHODS: The problem for making a reliable interpretation of the significance of a drawing is that a given feature could plausibly support several very different interpretations, depending which of many possible processes was active or dominant in the production of the drawing. Evidence from studies of clinical populations and experimental studies with non-selected samples are reviewed in the light of these possibilities. RESULTS: The review indicates that drawings are inaccurate and unreliable as personality or state assessments but can be influenced by children's emotional attitudes towards the topics depicted. The form of that expression, however, may be personal and idiosyncratic. Analogue studies of these effects undertaken with non-clinical samples under controlled conditions have produced mixed results. At best the reported effects are small. CONCLUSIONS: Children's drawings on their own are too complexly determined and inherently ambiguous to be reliable sole indicators of the emotional experiences of the children who drew them. Further research is needed to establish the extent to which such drawings can usefully facilitate assessment of children by other means or provide useful support as one of several converging lines of evidence.

Art↗
PubMed1993

Significant relationships and social supports of injecting drug users and their implications for HIV/AIDS services.

Strong social support networks have been associated with positive outcomes for health and well-being throughout the life-cycle. This paper investigates the structural and functional nature of social support networks of 100 injecting drug users (IDUs) in Sydney and the implications for HIV/AIDS services. Using a modified ISEL respondents saw support in terms of its tangibility of people and support, in terms of an appraisal of having friends, and as a self-esteem measure. We found the majority of respondents 'hung around' with other IDUs, lived with other IDUs, and were satisfied with the support they received from their friends. Friends appeared to be a more important source of social support than biological families and if respondents were to become HIV infected they would be more open about their status with friends than family. Where family was involved in support it was likely to be provided by mothers and siblings who were also the family members who knew about the respondent's drug use. There was no relationship between numbers of supports and satisfaction of support, suggesting quality and quantity of support were independent. Non-social supports were conceptualized primarily in terms of medical services.

Acquired Immunodeficiency Syndrome↗
PubMed1992

Origins of fear of dogs in adults and children: the role of conditioning processes and prior familiarity with dogs.

One hundred adults and 30 children completed questionnaires to investigate fear of dogs. Dog fearful adults asked to recall the origins of their fear reported classical conditioning experiences more frequently than vicarious acquisition or informational transmission. Overall, however, there was no difference in the frequency of attacks reported by the fearful and non-fearful groups. Significantly more fearful than non-fearful adults reported little contact with dogs prior to the onset of their fear which suggests that early non-eventful exposure to dogs may prevent a conditioning event from producing a dog phobia. Most adults reported that their fear began in childhood, and dog fear were more frequently reported by children than by adults. In the aggregate, however, dog-fearful adults and children differed in several ways; children were more likely than adults to report having received warnings about dogs, but also to recognize the potential attractiveness of a friendly dog. Unlike dog-fearful children, dog-fearful adults reported many other fears in addition to their fear of dogs. A better understanding of fear of dogs in adults may depend on discovering why some dog-fearful children, but not others, apparently lose their fear of dogs as they become older.

Adaptation, Psychological↗
PubMed1992

Children's drawings of topics differing in emotional significance--effects on placement relative to a self-drawing: a research note.

Children aged 4-6 years were asked to add drawings of someone they liked and someone they disliked to a picture of themselves. Liked figures were drawn closer than disliked figures to the self-figure only when the procedure was standardized and controlled so as to equate the tasks of positioning each of the added figures. With unmatched positioning tasks there was no effect of significance of figure on placement. The data demonstrate that a child's emotional attitude to a figure can affect its placement in a drawing, but that the effect is weak and easily masked.

Art↗
PubMed1992

Choledochal cyst and congenital anomalies of the pancreatico-biliary junction: the clinical findings, radiology and outcome in nine cases.

Nine patients with choledochal cyst have been reviewed. There was a 6:3 preponderance of females. Four patients presented in adulthood. Cholangiocarcinoma developed in three patients with an interval ranging from 2 to 35 years following surgery. The predominant complaint was of abdominal pain and symptoms had been present from weeks up to 28 years. Imaging by sonography may be all that is required in the paediatric age group, but in adults further confirmation of the choledochal cyst and the associated anomalous junction of the pancreatico-biliary duct (AJPB) by direct cholangiography is recommended.

Abdominal Pain↗
PubMed1991

An exploratory study of drawings by bereaved children.

Bereaved and non-bereaved children made drawings of a person, themselves, their family, and a topic of their choice; the drawings were then analysed to investigate whether the experience of bereavement was expressed in drawing in any reliable way. Bereaved children were no more likely than non-bereaved children to include indicators of emotional disturbance in their human figure drawings. Bereaved children, however, were reliably more likely than non-bereaved children to include themselves in a drawing of their family.

Adaptation, Psychological↗
PubMed1991

Pitfalls of bone scintigraphy in suspected hip fractures.

In a review of 2617 patients who were admitted with a suspected fractured neck of femur over a period of five years, 213 had normal or equivocal plain radiographs, and were subsequently investigated by bone scintigraphy. Normal scans were obtained in 127 (60%) cases. Of the remaining 86 cases, 82 (38%) were reported to show fractures of the proximal femur, three showed pubic ramus fractures, and one acetabular fracture was demonstrated. Review and follow-up has revealed eight false positive and two false negative scans. The various factors accounting for these errors are considered, and the clinical implications discussed. Careful analysis of accompanying plain radiographs is stressed when interpreting scintigrams.

Aged↗
PubMed1990

Children's drawings of an anxiety-eliciting topic: effects on the size of the drawing.

Our aim was to investigate whether or not children's drawings of a potentially threatening topic (a Hallowe'en witch) were made significantly smaller than drawings of a non-threatening topic (a woman). The first study confirmed an earlier claim by Craddick (1963) that drawings of a witch were made significantly smaller on the day before Hallowe'en compared to drawings made one week before or after, but we found that drawings of a non-threatening topic (a woman) changed in size in exactly the same way. Furthermore, we found no evidence that children became significantly more frightened of witches as Hallowe'en approached. In the second study, questionnaire responses were used to allocate children into two groups, those who were scared of witches and those who were not. Scared children drew both smaller witches and larger women than did non-scared children, with the result that relative heights of witches compared to women differed significantly between the two groups. However, only the difference in the height of the drawings of a woman was statistically significant. The implications of these results for the clinical assessment of children through their drawings are discussed.

Anxiety↗