Biomedical subjects

K Hughes

Publications and source records attributed to K Hughes.

At least 55 records · Page 3Linked to original sources

PubMed1998

Cardiovascular risk factors in relation to cigarette smoking: a population-based survey among Asians in Singapore.

To investigate how cigarette smoking increases the risk of cardiovascular disease, risk factors were compared between 166 cigarette smokers and 312 non-smokers, in a random sample of males (Chinese, Malays and Asian Indians) aged 30-69 years from the general population of Singapore. There was adjusted for age and ethnic group. The prevalence of hypertension was lower in cigarette smokers (15.2%) than non-smokers (21.9%), with the difference reduced by adjustment for body mass index (BMI). Smokers had: lower mean serum HDL-cholesterol (0.76 versus 0.81 mmol/l) and higher mean serum fasting triglyceride (1.92 versus 1.71 mmol/l), which will increase atherosclerosis; higher mean plasma fibrinogen (2.75 versus 2.67 g/l) and plasminogen activator inhibitor 1 [PAI-1] (24.9 versus 22.2 ng/ml), which will increase thrombosis; and lower mean plasma vitamin C (4.4 versus 6.4 mg/l) and serum selenium (118 versus 123 microg/l), which may increase atherosclerosis. Adjustment for BMI slightly increased the differences for HDL-cholesterol, fasting triglyceride, fibrinogen and PAI-1, indicating that less generalised obesity among smokers reduces their increased cardiovascular disease risk. Smoking was not found to be related to: diabetes mellitus; serum total cholesterol, LDL-cholesterol, apolipoproteins A1 and B and lipoprotein(a); plasma factor VIIc and prothrombin fragment 1 + 2; and plasma vitamins A and E and serum ferritin. There was no evidence of increased insulin resistance in smokers, as measured by mean fasting serum insulin.

Adult↗

PubMed1998

A survey of communication skills training in UK schools of medicine: present practices and prospective proposals.

It is now widely accepted that effective interpersonal communication is at the heart of quality health care delivery but that current standards in medicine must be improved (Numann 1988; Cowan et al. 1992). One approach acknowledged by the General Medical Council (1991) devotes more attention during training to the theme of communication, and quite significant modifications of the undergraduate medical curriculum are presently taking place. This article documents the results of a postal survey of the 26 UK Schools of Medicine, designed to illuminate current practices and future plans in respect of communication skills training (CST). As such, it takes advantage of the present period of ongoing curricular innovation and change to extend and update earlier reviews (Whitehouse 1991; Frederikson & Bull 1992). A total of 19 responses was received. Following preliminary analysis, the four schools who had already implemented their new curriculum were selected for further in-depth investigation by means of telephone interviews. In addition to reporting frequencies and percentages for responses to questions, cross-tabulations were carried out to explore relationships between certain of the findings. Apart from some consistency in CST teaching methods adopted, the overall picture to emerge is one of considerable variability in such areas as course content, timing, duration and assessment. Foremost among the difficulties encountered in implementing CST appeared to be lack of adequate physical resources and suitably trained staff. Future plans were often sketchy and inchoate. Results are discussed and tentative recommendations for the further development of CST in the medical curriculum proffered.

Clinical Competence↗

PubMed1998

NF-kappaB only partially mediates Epstein-Barr virus latent membrane protein 1 activation of B cells.

The latent membrane protein 1 (LMP1) of Epstein-Barr virus (EBV) is required for EBV-induced immortalization of human B cells and causes tumorigenic transformation of cell lines. LMP1 expression induces phenotypic changes resembling B cell activation, such as cell size increase and up-regulation of cell surface activation markers. LMP1 contains two domains that activate the transcription factor NF-kappaB, one through interactions with TRAF proteins and the other with the TRADD protein. The purpose of the present study was to investigate the importance of NF-kappaB induction in the up-regulation of the B cell activation markers ICAM-1 and CD71 by LMP1. This study shows that expression of LMP1 activates transcription from p50/p65- and c-Rel-responsive promoters, and that this activity can be completely inhibited by expression of a dominant inhibitory IkappaB mutant. ICAM-1 and CD71 are nevertheless up-regulated by LMP1 in primary B cells and cell lines expressing the dominant IkappaB. Furthermore, LMP1-induced cell size increase of primary B cells was unaffected by IkappaB expression. It was concluded that even when LMP1 is unable to activate NF-kappaB, it is still capable of inducing certain characteristics of activated B cells, strongly suggesting that LMP1 can also activate cells independently of NF-kappaB.

B-Lymphocytes↗

PubMed1998

Vitamins, selenium, iron, and coronary heart disease risk in Indians, Malays, and Chinese in Singapore.

STUDY OBJECTIVE: To examine the hypothesis that the higher rates of coronary heart disease (CHD) in Indians (South Asians) compared with Malays and Chinese is partly because of differences in antioxidants (vitamins A, C, and E, and selenium) and pro-oxidants (iron). DESIGN: Cross sectional study of the general population. SETTING: Singapore. PARTICIPANTS: Random sample of 941 persons aged 30 to 69 years. MAIN RESULTS: There were moderate correlations between vitamin A and vitamin E, and between these vitamins and selenium. Mean plasma vitamins A and E were similar by ethnic group. Vitamin A concentration for Indians were (men 0.66 and women 0.51 mg/l), Malays (men 0.67 and women 0.54 mg/l), and Chinese (men 0.68 and women 0.52 mg/l). Vitamin E concentrations for Indians were (men 12.9 and women 12.8 mg/l), Malays (men 13.6 and women 13.3 mg/l), and Chinese (men 12.6 and women 12.6 mg/l). In contrast, mean plasma vitamin C concentrations were lower in Indians (men 5.7 and women 6.9 mg/l) and Malays (men 5.1 and women 6.4 mg/l) than Chinese (men 6.3 and women 8.4 mg/l). Mean serum selenium was lower in Indians (men 117 and women 115 micrograms/l) than Malays (men 122 and women 122 micrograms/l) and Chinese (men 126 and women 119 micrograms/l). Mean serum ferritin was much lower in Indians (men 132 and women 50 micrograms/l) than Malays (men 175 and women 85 micrograms/l) and Chinese (men 236 and women 92 micrograms/l). MAIN CONCLUSIONS: Lower vitamin C and selenium in Indians, particularly in combination, could play a part in their increased risk of CHD. Vitamins A and E, and ferritin (iron) have no such role. Lower vitamin C in Indians and Malays is probably because of its destruction by more prolonged cooking. In Indians, lower selenium is probably because of a lower dietary intake and the much lower ferritin to a lower dietary intake of iron and its binding by phytates.

Adult↗

PubMed1998

Plasma vitamins A, C and E in the general population of Singapore, 1993 to 1995.

The National University of Singapore Heart Study measured cardiovascular risk factors, including selected plasma vitamins, on a random sample of the general population aged 30 to 69 years. Plasma vitamins A and E were normal and similar by ethnic group. Mean plasma vitamin A levels were: Chinese (males 0.68 and females 0.52 mg/L), Malays (males 0.67 and females 0.54 mg/L), and Indians (males 0.66 and females 0.51 mg/L). Mean plasma vitamin E levels were: Chinese (males 12.6 and females 12.6 mg/L), Malays (males 13.6 and females 13.3 mg/L), and Indians (males 12.9 and females 12.8 mg/L). No person had plasma vitamin A deficiency (< 0.01 mg/L) and only 0.1% had vitamin E deficiency (< 5.0 mg/L). In contrast, plasma vitamin C was on the low side and higher in Chinese than Malays and Indians. Mean plasma vitamin C levels were: Chinese (males 6.3 and females 8.4 mg/L), Malays (males 5.1 and females 6.4 mg/L), and Indians (males 5.7 and females 6.9 mg/L). Likewise, the proportions with plasma vitamin C deficiency (< 2.0 mg/L) were lower in Chinese (males 14.4 and females 0.7%), than Malays (males 19.7 and females 7.2%), and Indians (males 17.8 and females 11.0%). Relatively low levels of plasma vitamin C may contribute to the high rates of coronary heart disease and cancer in Singapore. In particular, lower plasma vitamin C in Malays and Indians than Chinese may contribute to their higher rates of coronary heart disease. However, plasma vitamin C does not seem to be involved in the higher rates of cancer in Chinese than Malays and Indians. The findings suggest a relatively low intake of fresh fruits and a higher intake is recommended. Also, food sources of vitamin C may be destroyed by the high cooking temperatures of local cuisines, especially the Malay and Indian ones.

Adult↗

PubMed1998

Serum ferritin and iron status in the general population of Singapore, 1993 to 1995.

The National University of Singapore Heart Study is a cross-sectional survey of cardiovascular risk factors in persons aged 30 to 69 years from the general population of Singapore, with 957 persons having measurements of serum ferritin. For males aged 30 to 69 years, mean serum ferritin concentrations were highest in Chinese (236 micrograms/L), followed by Malays (175 micrograms/L) and then Indians (132 micrograms/L). For females aged 30 to 49 years (pre-menopausal), mean levels were higher in Chinese (61 micrograms/L) and Malays (55 micrograms/L) than Indians (30 micrograms/L), and likewise for the 50 to 69 years age group (post-menopausal) where the mean values were 144 micrograms/L for Chinese, 141 micrograms/L for Malays, and 85 micrograms/L for Indians. The proportions with iron deficiency (serum ferritin < 12 micrograms/L) were low in males aged 30 to 69 years (1.9%) and in females aged 50 to 69 years (2.6%), but fairly high in females aged 30 to 49 years and was highest in Indians (23.0%), followed by Malays (15.6%), and then Chinese (7.8%). The much lower ferritin in Indians is maybe partly due to their more vegetarian diet and binding of dietary iron by phytates, but other mechanisms probably exist. Only 0.4% of males and no females had serum ferritin > or = 1000 micrograms/L. Levels of serum ferritin were somewhat higher than that reported in the USA. The overall iron status in Singapore seems to be satisfactory, although pre-menopausal females (especially Indians) have a fairly high rate of iron deficiency and these females need to be identified and treated with iron supplementation.

Adult↗

PubMed1998

Serum selenium in the general population of Singapore, 1993 to 1995.

Selenium is a trace element which plays a vital role in many metabolic functions and in particular is an integral part of the antioxidant enzyme glutathione peroxidase. It may be involved in the prevention of a number of diseases including cardiovascular diseases and cancer, which are the main causes of death in Singapore with ethnic differences. The National University of Singapore Heart Study measured cardiovascular risk factors, including serum selenium, in a random of the general population aged 30 to 69 years from 1993 to 1995. Mean serum selenium was higher in Chinese (males 126 and females 119 micrograms/L) and Malays (males 122 and females 122 micrograms/L) than Indians (males 117 and females 115 micrograms/L). These levels (with an estimated mean of 122 micrograms/L in Singapore) are lower than those in the USA but higher than those in Western Europe. The proportions with serum selenium < 80 micrograms/L (classified as low values) were low, though highest in Indians (males 1.2% and females 1.2%), then Chinese (males 0.6% and females 1.3%) and then Malays (males 0.0% and females 0.0%), but the differences were not statistically significant. The overall estimate for the prevalence of low selenium in Singapore was 0.8%. It is concluded that levels of serum selenium in Singapore are satisfactory and no action with regard to dietary supplementation is needed. Serum selenium levels are slightly lower in Indians than in Chinese and Malays (probably due to a more vegetarian diet) and this may make a small contribution to Indians' higher rates of coronary heart disease compared to Chinese and Malays.

Adult↗

PubMed1997

Evolution of foraging behavior in Drosophila by density-dependent selection.

One of the rare examples of a single major gene underlying a naturally occurring behavioral polymorphism is the foraging locus of Drosophila melanogaster. Larvae with the rover allele, forR, have significantly longer foraging path lengths on a yeast paste than do those homozygous for the sitter allele, fors. These variants do not differ in general activity in the absence of food. The evolutionary significance of this polymorphism is not as yet understood. Here we examine the effect of high and low animal rearing densities on the larval foraging path-length phenotype and show that density-dependent natural selection produces changes in this trait. In three unrelated base populations the long path (rover) phenotype was selected for under high-density rearing conditions, whereas the short path (sitter) phenotype was selected for under low-density conditions. Genetic crosses suggested that these changes resulted from alterations in the frequency of the fors allele in the low-density-selected lines. Further experiments showed that density-dependent selection during the larval stage rather than the adult stage of development was sufficient to explain these results. Density-dependent mechanisms may be sufficient to maintain variation in rover and sitter behavior in laboratory populations.

Animals↗

PubMed1997

Lymph node negative invasive breast carcinoma 1 centimeter or less in size (T1a,bNOMO): clinicopathologic features and outcome.

BACKGROUND: Patients with lymph node negative invasive breast carcinomas < or = 1 cm in size have a low recurrence rate and may be spared adjuvant therapy. Reliable prognostic features will help physicians design appropriate treatment for these patients. METHODS: The clinicopathologic features, prognostic marker profiles, and clinical outcomes of 88 T1a,bN0M0 carcinomas in 87 patients who presented between 1975 and 1990 were studied. The size of each tumor was determined by direct measurement of histologic sections. The median follow-up was 7.8 years (range, 4-15 years). The characteristics of tumors diagnosed between 1975 and 1983 and between 1984 and 1990 were also compared. RESULTS: Before 1984, the majority of patients presented with palpable mass lesions, whereas from 1984 on, more patients presented with mammographic abnormalities. However, no significant differences in the pathologic features of tumors were observed between the two periods. There were only 3 locoregional recurrences (3%) and 4 distant recurrences (5%). Palpable tumors had worse prognoses than mammographically detected lesions (P = 0.02). Histologic grade, lymphatic invasion, hormone receptors, Ki-67 antigen, and bcl-2 expression were significant univariate prognostic indicators. The small number of patients in the series precluded multivariate analysis. None of the 43 patients (49%) with tumors < or = 0.5 cm, or of histologic and nuclear Grade 1, or of favorable histologic types developed recurrences; and their outcomes were significantly better than those of other patients (P = 0.013). Tumors originally classified as T1b, but which exceeded 1 cm on review and were excluded from the study, had a significantly higher distant recurrence rate (23%) than bona fide T1a,b carcinomas (P = 0.03). CONCLUSIONS: T1a,bN0M0 carcinomas have a low recurrence rate, especially those tumors < or = 0.5 cm, or of low histologic or nuclear grade, or of favorable histologic type. The high recurrence among patients with tumors initially understaged as T1a,b carcinoma underscores the importance of accurately determining tumor size.

Adult↗

PubMed1997

Young people, alcohol, and designer drinks: quantitative and qualitative study.

OBJECTIVE: To examine the appeal of "designer drinks" to young people. DESIGN: Qualitative and quantitative research comprising group discussions and questionnaire led interviews with young people accompanied by a self completion questionnaire. SETTINGS: Argyll and Clyde Health Board area, west Scotland. SUBJECTS: Eight groups aged 12-17 years; 824 aged 12-17 recruited by multistage cluster probability sample from the community health index. RESULTS: Young people were familiar with designer drinks, especially MD 20/20 and leading brands of strong white cider. Attitudes towards these drinks varied quite distinctly with age, clearly reflecting their attitudes towards and motivations for drinking in general. The brand imagery of designer drinks-in contrast with that of more mainstream drinks-matched many 14 and 15 year olds' perceptions and expectations of drinking. Popularity of designer drinks peaked between the ages of 13 and 16 while more conventional drinks showed a consistent increase in popularity with age. Consumption of designer drinks tended to be in less controlled circumstances and was associated with heavier alcohol intake and greater drunkenness. CONCLUSIONS: Designer drinks are a cause for concern. They appeal to young people, often more so than conventional drinks, and are particularly attractive to 14-16 year olds. Consumption of designer drinks is also associated with drinking in less controlled environments, heavier drinking, and greater drunkenness. There is a need for policy debate to assess the desirability of these drinks and the extent to which further controls on their marketing are required.

Adolescent↗

PubMed1997

Evolution of the lambda or twin-chorionic peak sign in dichorionic twin pregnancies.

OBJECTIVE: To study the sonographic evolutaion of the chorionic tissue projection at the intertwin membrane-placental junction, or lambda sign, or twin-chorionic peak sign, in dichorionic twin pregnancies and to determine the effect of placental location on its prevalence during the first half of pregnancy. METHODS: We prospectively recruited women with twin pregnancies undergoing sonographic screening for chromosomal abnormalities at 10-14 weeks' gestation for this study. The presence or absence of the lambda sign and the position of the placenta(s) were recorded in all cases. The presence of the lambda sign was evaluated prospectively at 16 and 20 weeks' gestation. RESULTS: There were 101 twin pregnancies with a lambda sign identified at 10-14 weeks' gestation, 67 with fused placentas and 34 with separate placentas. At 16 weeks, the lambda sign was present in all 67 pregnancies with fused placentas (100%) and in 31 of 34 (91%) pregnancies with separate placentas. At 20 weeks, the lambda sign was present in 25 of the 34 (74%) pregnancies with separate placentas and in 62 of the 67 (93%) with fused placentas. The lambda sign was identified subsequently in none of the 53 pregnancies in which it was absent at 10-14 weeks' gestation. CONCLUSIONS: At 10-14 weeks' gestation, twin pregnancies with the lambda sign can be classified as dichorionic and pregnancies with absent lambda sign can be classified as monochorionic and therefore monozygotic. At 16-20 weeks, the lambda sign is indicative of dichorionicity but its absence does not exclude dizygosity.

Adolescent↗

PubMed1997

Increased nuchal translucency thickness at 10-14 weeks of gestation as a predictor of severe twin-to-twin transfusion syndrome.

The study examines a possible association between increased nuchal translucency thickness at 10-14 weeks of gestation in monochorionic twin pregnancies and the subsequent development of severe twin-to-twin transfusion syndrome (TTS). In 132 monochorionic twin pregnancies, including 16 that developed severe TTS at 15-22 weeks of gestation and 116 that did not develop TTS, crown-rump length, nuchal translucency thickness and fetal heart rate were measured at 10-14 weeks. In those that developed severe TTS, the prevalence of nuchal translucency thickness above the 95th centile of the normal range and the intertwin difference in nuchal translucency thickness and fetal heart rate were significantly higher than in the non-TTS group; there were no significant differences between the groups in the inter-twin difference in crown-rump length. For fetal nuchal translucency above the 95th centile, the positive and negative predictive values for the development of TTS were 38% and 91%, respectively; the likelihood ratios of nuchal translucency above or below the 95th centile for the development of severe TTS were 4.4 (1.8-9.7) and 0.7 (0.4-0.9), respectively. These findings demonstrate that the underlying hemodynamic changes associated with TTS may manifest as increased fetal nuchal translucency thickness at 10-14 weeks of gestation.

Adult↗

PubMed1997

Use of carcinoembryonic antigen radioimmunodetection and computed tomography for predicting the resectability of recurrent colorectal cancer.

OBJECTIVE: The objective was to determine the role of arcitumomab (CEA-Scan; Immunomedics, Morris Plains, NJ), an anticarcinoembryonic antigen (CEA) Fab' labeled with technetium-99m, in the presurgical evaluation of patients with recurrent or metastatic colorectal carcinoma. SUMMARY BACKGROUND DATA: Surgical resection is the only method known to cure recurrent or metastatic colorectal carcinoma. The location and extent of disease must be determined before surgery. The role of antibody imaging, a new cancer detection modality, in preoperative evaluation for resection of locally recurrent or metastatic colorectal cancer has not been established, either alone or in combination with standard diagnostic modalities. METHODS: In a blinded analysis of 209 patients with known or suspected colorectal cancer, the accuracy of arcitumomab, alone and combined with computed tomography (CT), was compared to that of CT for predicting abdominopelvic tumor resectability by correlating the results with surgical and histopathologic findings. RESULTS: Arcitumomab alone or combined with CT was found to be significantly more accurate for predicting surgical outcome than CT alone. When the results of CT and arcitumomab were concordant for abdominopelvic resectability, nonresectability, or absence of disease, the prediction was accurate in 67%, 100%, and 64%, respectively. Thus, the concordance for nonresectability (100% correct) may obviate the need for other diagnostic modalities or exploratory surgery. When the two tests were discordant, arcitumomab was correct substantially more often than CT. Because the liver is the most common site of distant metastasis in colorectal cancer, a subset of patients with hepatic disease was also analyzed; findings were similar to the overall resectability results. The product's safety profile was excellent: the incidence of induction of an immune response against arcitumomab was <1% and that of potentially adverse events was 1.2%. CONCLUSIONS: The accuracy of arcitumomab for assessing resectability status is greater than that of CT, both in all patients undergoing evaluation for curative abdominopelvic resection of colorectal cancer and in the subset of patients with suspected or proven liver metastases. The additional use of arcitumomab with CT potentially doubles the number of patients who could be saved the cost, morbidity, and mortality of unnecessary abdominopelvic surgery and increases those who are potentially resectable for cure by 40%.

Adult↗

PubMed1997

Effects of embryo reduction from trichorionic triplets to twins.

Sixty-six trichorionic triplet pregnancies reduced to twins were compared with 47 triplet pregnancies that were not reduced. The miscarriage rate was higher (7.6% compared with 2.6%) but the number delivering between 24 and 32 weeks was lower (8.2% compared with 24.0%). Since severe preterm delivery is associated with risks of neonatal death and severe handicap, embryo reduction of triplets to twins may not improve the chance of survival but may reduce the rate of handicap.

Abortion, Spontaneous↗

PubMed1997

The hidden mortality of monochorionic twin pregnancies.

In an ultrasound screening study at 10 to 14 weeks of gestation for measurement of fetal nuchal translucency thickness there were 102 monochorionic and 365 dichorionic twin pregnancies. In the monochorionic compared with the dichorionic pregnancies there was a higher rate of fetal loss before 24 weeks of gestation (12.2% versus 1.8%), perinatal mortality (2.8% versus 1.6%), prevalence of delivery before 32 weeks (9.2% versus 5.5%), and prevalence of birthweight below the 5th centile in both twins (7.5% versus 1.7%). However, the proportion of pregnancies with a birthweight discordancy of more than 25% was similar in the two groups (11.3% versus 12.1%).

Abortion, Spontaneous↗

PubMed1997

The prevalence and consequences of missed abortion in twin pregnancies at 10 to 14 weeks of gestation.

In singleton pregnancies at 10 to 14 weeks of gestation the prevalence of missed abortion is about 2%. In an ultrasound screening study at 10 to 14 weeks of gestation involving 492 twin pregnancies the prevalence of missed abortion was about twice as high as in singletons. The risk of subsequent miscarriage in twin pregnancies with one missed abortion was about ten times higher than in normal twin pregnancies. These findings may have important implications both in terms of counselling and for future research into the causes of miscarriage.

Abortion, Missed↗

PubMed1997

Maternal serum alpha-fetoprotein in fetal neural tube and abdominal wall defects at 10 to 14 weeks of gestation.

Maternal serum alpha-fetoprotein concentration was determined in nine pregnancies with fetal anencephaly, seven with exomphalos containing liver, two with spina bifida and 100 normal controls at 10 to 14 weeks of gestation. The median alpha-fetoprotein in the group with fetal anencephaly and exomphalos was significantly higher than in normal fetuses but the sensitivity of this test is likely to be only about 30% for a false positive rate of 5%.

Abdominal Muscles↗

PubMed1997

Dichorionic twins discordant for intrauterine growth retardation.

A policy of expectant management until 32 weeks of gestation in 29 dichorionic pregnancies discordant for growth retardation resulted in an overall mortality of 24% (95% CI 13.9-37.2%) and a handicap of 2.2% (95% CI 0-12.0%). None of the normally grown co-twins died or was handicapped as a result of iatrogenic prematurity.

Delivery, Obstetric↗