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Hong HL, Ton TV, Devereux TR, Moomaw C, Clayton N, Chan P, Dunnick JK, Sills RC. Chemical-specific alterations in ras, p53, and beta-catenin genes in hemangiosarcomas from B6C3F1 mice exposed to o-nitrotoluene or riddelliine for 2 years. Toxicol Appl Pharmacol 2003; 191:227-34. [PMID: 13678655 DOI: 10.1016/s0041-008x(03)00165-0] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The most prominent neoplastic lesions in mice in the 2-year studies of o-nitrotoluene and riddelliine were hemangiosarcomas. Fifteen o-nitrotoluene-induced hemangiosarcomas of the skeletal muscle, subcutaneous tissue, and mesentery; 12 riddelliine-induced hemangiosarcomas of the liver; and 15 spontaneous subcutaneous hemangiosarcomas were examined for genetic alterations in ras, p53, and beta-catenin genes. Mutations in at least one of these genes were identified in 13 of 15 (87%) of the o-nitrotoluene-induced hemangiosarcomas with missense mutations in p53 exons 5-8 detected in 11 of 15 (73%) of these neoplasms. Seven of 15 (47%) hemangiosarcomas from mice exposed to o-nitrotoluene had deletions at exon 2 splice sites or smaller deletions in the beta-catenin gene. K-ras mutation was detected in only 1 of the 15 (7%) o-nitrotoluene-induced hemangiosarcomas. In contrast to the o-nitrotoluene study, 7/12 (58%) riddelliine-induced hemangiosarcomas had K-ras codon 12 GTT mutations and, when screened by immunohistochemistry, 9/12 (75%) had strong staining for the p53 protein in malignant endothelial cells, the cells of origin of hemangiosarcomas. Riddelliine-induced hemangiosarcomas were negative for the beta-catenin protein. Spontaneous hemangiosarcomas from control mice lacked both p53 and beta-catenin protein expression and ras mutations. Our data indicated that p53 and beta-catenin mutations in the o-nitrotoluene-induced hemangiosarcomas and K-ras mutations and p53 protein expression in riddelliine-induced hemangiosarcomas most likely occurred as a result of the genotoxic effects of these chemicals. It also suggests that these mutations play a role in the pathogenesis of the respective hemangiosarcomas in B6C3F1(1) mice.
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Chen R, Gosavi NS, Langston JW, Chan P. Parkin mutations are rare in patients with young-onset parkinsonism in a US population. Parkinsonism Relat Disord 2003; 9:309-12. [PMID: 12781599 DOI: 10.1016/s1353-8020(03)00018-x] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Parkin mutations have been associated with an autosomal recessive-juvenile parkinsonism, but it is unclear how common such patients are in a US based clinic population. In this study, we screened for parkin gene mutations in a clinic-based series of 27 consecutive patients in the US with typical parkinsonism beginning before the age of 50 years. Two patients began the disease before the age of 30 years. Among the 27 patients screened, only one patient, whose disease began at the age of 24 years, was found to harbor a parkin mutation (a 40 bp deletion in exon 3). In addition, we also identified four new polymorphisms in the open reading frames of the parkin gene in this population. Our results suggest parkinsonism due to mutations in the parkin gene is extremely rare in the US population when the disease begins over the age of 30.
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Chan P, Cheng JT. 2P-0434 Antihyperglycemic action of angiotensin II receptor antagonist, valsartan, in streptozotocin-induced diabetes rats. ATHEROSCLEROSIS SUPP 2003. [DOI: 10.1016/s1567-5688(03)90576-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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279
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Cheng TH, Chan P, Chen JJ. 1P-0177 Inhibitory effect of resveratrol on cyclic strain-induced endothelin-1 gene expression in endothelial cells. ATHEROSCLEROSIS SUPP 2003. [DOI: 10.1016/s1567-5688(03)90250-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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280
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Liu J, Chan P, Cheng TH, Chen JJ. 4P-1203 Inhibitory effect of trilinolein on angiotensin II-induced cardiomyocytes hypertrophy. ATHEROSCLEROSIS SUPP 2003. [DOI: 10.1016/s1567-5688(03)91459-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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281
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Chan P. Vascular Brachytherapy. 2nd ed. R. Waksman (ed.). 260 × 180 mm. Pp. 630. Illustrated. 1998. Armonk, New York: Futura Publishing Company. Br J Surg 2002. [DOI: 10.1046/j.1365-2168.1999.1101b.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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282
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Stewart JB, Norman KE, John AE, Chan P, Hellewell PG. P-selectin deficiency is protective against remote organ injury in a model of ruptured abdominal aortic aneurysm. Br J Surg 2002. [DOI: 10.1046/j.1365-2168.2001.01757-34.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Abstract
Background
Multisystem organ failure (MSOF) accounts for 50–60 per cent of postoperative deaths following repair of ruptured abdominal aortic aneurysm (AAA). A murine model is described in which the combined insults of hypotension and aortic clamping reproduce the physiological changes during repair of ruptured AAA. The resulting remote organ injury (the hallmark of MSOF) is prevented in the absence of the adhesion molecule P-selectin, which mediates neutrophil–endothelial interaction.
Methods
C57BL6 wild-type mice (n = 4) and mice constitutively unable to express P-selectin (P–/–) (n = 4) were subjected to 60 min of controlled hypotension followed by cross-clamping of the infrarenal aorta for 60 min, reinfusion of shed blood and then 60 min of reperfusion. Controls (n = 16) were sham-operated, had hypotension only or clamp/reperfusion only. Lungs and kidneys were harvested and assayed for the neutrophil-specific marker myeloperoxidase (MPO), which indicates inflammatory infiltrate in the tissue.
Results
MPO levels in the organs of C57BL6 mice subjected to hypotension and aortic clamping were 50 times greater than those in sham-operated mice. MPO levels in sham-operated P–/– animals were similar to those in sham-operated C57BL6 mice. MPO levels in the lungs and kidneys of P–/– mice subjected to hypotension and aortic clamping were unchanged from those in sham-operated P–/– mice.
Conclusion
The combined effects of hypotension and infrarenal aortic clamping, followed by reperfusion, are synergistic. This gives rise to a profound early inflammatory reaction in tissues remote from the site of ischaemia–reperfusion, which is likely to contribute towards clinical MSOF after ruptured AAA repair. Absence of the adhesion molecule P-selectin protects against this remote organ injury.
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Chan P, Kenny SR. National consistency and provincial diversity in delivery of long-term care in Canada. J Aging Soc Policy 2002; 13:83-99. [PMID: 12216364 DOI: 10.1300/j031v13n02_07] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
The aim of this article is to demonstrate the diversity in delivery of long-term care at the provincial level, within a national legislative framework that provides universal health insurance and public administration. Not all provinces have legislated provision of long-term care, but mandates for provincial long-term care programs typically address the needs of those with chronic health needs and maintain them in the community for as long as possible. Eligibility is based on common criteria of residency, health need, facility, assessment, and consent. The three common components of the service delivery system are institutional care, community-based services, and home-based services; the kinds of services within each component and the mix among them vary from province to province. There are also five common features in provincial service delivery systems: single point of entry, assessment, client classification, case management, and single administration. Throughout the article, examples from different provinces show the varying ways in which these aspects of service delivery have been addressed, and recent innovations have furthered this diversity. A detailed account of quality management systems also shows that while all provinces have adopted a common set of principles, they use a range of methods to pursue quality of care and to promote good practice.
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Tsai JC, Chan P, Wang CH, Jeng C, Hsieh MH, Kao PF, Chen YJ, Liu JC. The effects of exercise training on walking function and perception of health status in elderly patients with peripheral arterial occlusive disease. J Intern Med 2002; 252:448-55. [PMID: 12528763 DOI: 10.1046/j.1365-2796.2002.01055.x] [Citation(s) in RCA: 90] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
OBJECTIVE To determine the effects of 12-week exercise programme on ambulatory function, free-living daily physical activity and health-related quality of life in disabled older patients with intermittent claudication. DESIGN Prospective, randomized controlled trial. SETTING University Medical Center and Veterans Affairs Medical Center, Taipei, Taiwan. SUBJECTS Thirty-two of 64 patients with Fontaine stage II peripheral arterial occlusive disease (PAOD) were randomized to exercise training and 32 to usual care control. Five patients from the exercise group and six patients from the control group dropped out, leaving 27 and 26 patients, respectively, completing the study in each group. INTERVENTIONS Twelve weeks of treadmill exercise training. MAIN OUTCOME MEASURES Treadmill walking time to onset of claudication pain and to maximal claudication pain, 6-min walk distance, self-reported ambulatory ability and perceived health-related quality of life (QOL). RESULTS Compliance of exercise programme was 83% of the possible sessions. Exercise training increased treadmill walking time to onset of claudication pain by 88% (P < 0.001), time to maximal pain by 70% (P < 0.001), and 6-min walk distance by 21% (P < 0.001). SUBJECTS Perception of health-related QOL improved from 12% to 178% in the exercise group. These improvements were significantly better than the changes in the control group (P < 0.05). CONCLUSIONS Significant improvements in claudication following 12-week exercise training in elderly PAOD patients were observed. Increase in treadmill walking time to maximal claudication pain in these patients translated into the improvement of perceived physical health, which enabled the patients to become more functionally independent.
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Dean NL, Phillips SJ, Chan P, Tan SL, Ao A. Reported relationship between increased CTG repeat lengths in myotonic dystrophy and azoospermia. Hum Reprod 2002; 17:3003-4; author reply 3004. [PMID: 12407064 DOI: 10.1093/humrep/17.11.3003-a] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
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286
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Chan P. In whose best interests? An examination of the ethics of the UK government's White Paper 'Reforming the Mental Health Act'. J Psychiatr Ment Health Nurs 2002; 9:399-404. [PMID: 12164901 DOI: 10.1046/j.1365-2850.2002.00513.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Throughout history the legislative framework for the treatment of the mentally ill has reflected societies' attitudes, and the proposals in the United Kingdom (UK) government's White Paper 'Reforming the Mental Health Act' are no exception. This paper examines some of the fundamental ethical issues invoked by the proposals, particularly the concept of paternalism and use of risk assessment in determining 'best interests'. The issue of power in relation to the mentally ill is also examined, alongside the impact of the change on nurses' ethical decision making. As will be seen, the proposed Act will require high standards of professional practice to ensure the ethical application of care, particularly in the case of individuals diagnosed as suffering from 'dangerous and severe personality disorders'. Nurses need to ensure that the interventions used are of the highest quality and are indeed in the patient's 'best interests'. If they are not, then again nurses need to be very clear as to why the profession should be involved at all. Nurses should demonstrate vigilance and high professional standards to ensure they are maintaining rigorous safeguards to promote the public interest. Although relating specifically to UK legislation the underlying ethical dilemmas posed by this proposed legislation are relevant to all mental health nurses, as they challenge fundamental assumptions regarding the role of nurses in supporting mental health legislation that may have a social, rather than therapeutic, function.
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Zheng YX, Chan P, Pan ZF, Shi NN, Wang ZX, Pan J, Liang HM, Niu Y, Zhou XR, He FS. Polymorphism of metabolic genes and susceptibility to occupational chronic manganism. Biomarkers 2002; 7:337-46. [PMID: 12171760 DOI: 10.1080/13547500210146740] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
In this study we investigated genetic polymorphisms of five metabolizing genes and their association with occupational chronic manganism. We recruited 49 patients with chronic manganism and 50 unrelated healthy control subjects who were welders and ferromanganese smelters and occupationally exposed to manganese dust and fume in the same workshops from three metallurgical industries. The controls were matched to the cases by sex, age, cigarette and alcohol intake, as well as the manganese exposure duration. Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) was used to genotype the cytochrome P450 2D6L gene (CYP2D6L) and the NAD(P)H:quinone oxidoreductase gene (NQO1). Allele-specific PCR was used to detect the cytochrome P450 1A1 gene (CYP1A1), and the glutathione-S-transferase mu and theta genes (GSTM and GSTT). The frequency of polymorphic alleles, a mutation of CYP2D6L, was significantly lower in patients with chronic manganism (16.3%) than in controls (29.0%). Individuals with the homozygote polymorphism (L/L) of CYP2D6 had a 90% decreased risk of chronic manganism compared with the wild-type (Wt/Wt) (odds ratio =0.10, 95% confidence interval = 0.01-0.82). A significant association between the CYP2D6 genotype subgroup and the latency of chronic manganese poisoning was also found. Patients who had homozygous (L/L) or heterozygous (Wt/L) mutant alleles developed manganism an average of 10 years later than those who were homozygous wildtype (Wt/Wt). However, the allele and genotype frequencies of CYP1A1 and NQO1 genes were distributed similarly in cases and controls. In addition, no difference in the frequencies of GSTM1 and GSTT1 null genotypes were observed between cases and controls. The results suggest that CYP2D6L gene polymorphism might influence susceptibility to manganese-induced neurotoxicity. However, because of limited sample size, our results should be validated in large-scale studies.
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Woulfe JM, Duke R, Middeldorp JM, Stevens S, Vervoort M, Hashimoto M, Masliah E, Chan P, Di Monte DA, Langston JW, Petzinger G, Hoogendoorn H, Munoz DG. Absence of elevated anti-alpha-synuclein and anti-EBV latent membrane protein antibodies in PD. Neurology 2002; 58:1435-6. [PMID: 12011302 DOI: 10.1212/wnl.58.9.1435] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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289
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Sceh S, Corselli J, Chan P, Bailey L. Ovarian stimulation and ultrasound-guided oocyte retrieval in baboon (Papio Cynocephalus Anubis) during pituitary suppression with a GnRH agonist. Acta Vet Hung 2002; 49:443-50. [PMID: 11942123 DOI: 10.1556/004.49.2001.4.8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The objective of this study was to investigate whether baboon females respond to an ovarian stimulation protocol incorporating pituitary suppression with a GnRH agonist (GnRHa) and either highly purified human FSH (hphFSH) or recombinant human FSH (rhFSH) with follicular development and oocyte maturation. A modified human ovulation induction protocol was applied to 5 adult female baboons with a history of regular menstrual cycles (33-34 days). A long-acting GnRHa implant containing goserelin acetate was placed subcutaneously (s.c.) on Days 22-24 of their menstrual cycle. Concentrations of serum oestradiol (E2), progesterone (P4) and human FSH were obtained by ELISA. Menses occurred approximately 10 days after GnRHa implantation. Daily hphFSH or rhFSH (75 IU i.m.) treatments were started approximately 10 days following menses. When the majority of follicles were > or = 5 mm in diameter and the E2 levels had reached a maximum, hCG (2000 IU i.m.) was administered to induce final maturation of oocytes and ovulation. Thirty to 34 h after hCG administration, transabdominal follicular aspiration was performed using a variable frequency transvaginal transducer with ultrasound. A total of 71 oocytes were collected from 4 animals (average: 17). The meiotic maturity of oocytes was evaluated 3 h after retrieval. Ninety-one percent of oocytes were in metaphase 2 and of grades I and II which are appropriate for in vitro insemination.
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Cseh S, Corselli J, Chan P, Bailey L. Superovulation using recombinant human FSH and ultrasound-guided transabdominal follicular aspiration in baboon (Papio anubis). Anim Reprod Sci 2002; 70:287-93. [PMID: 11943499 DOI: 10.1016/s0378-4320(02)00007-6] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
The response of baboon females to a modified human ovarian stimulation protocol incorporating start of pituitary suppression in the luteal phase of the cycle with a GnRH agonist (GnRHa) and recombinant human FSH (rhFSH) was studied. A long-acting GnRHa implant supplying goserelin acetate was administered s.c. to six adult female baboons experiencing regular menstrual cycles (33-34 days) on days 22-24 of the cycle. Follicular development was monitored by transabdominal ultrasonography and serum levels of E2 and progesterone (P4) and rhFSH were determined by ELISA. Menses occurred 9-10 days after GnRHa administration. Daily i.m. administration of 75 IU rhFSH commenced 9-10 days after menses and continued for 9-10 days. When most follicles were > or =5mm diameter and serum E2 had reached its maximum level, 2000 IU hCG was administered i.m. to induce follicle maturation. Transabdominal ultrasound-guided follicular aspiration of follicles > or =2mm diameter was performed 30-34h after hCG administration. One baboon did not show an adequate response to rhFSH stimulation. This animal did not receive further treatment and no data for it are presented. The number of follicles aspirated was 21+/-4 and 17.2+/-3.8 oocytes were recovered per animal with an average recovery rate of 82% (86/105). The number of oocytes collected from five animals were 14, 21, 16, 15, and 20 (n=86). Most of the oocytes recovered were in metaphase II and 3h after recovery 91% (78/86) were considered suitable for in vitro fertilization. It was concluded that recombinant human FSH can successfully induce follicular recruitment and oocyte maturation in baboon females during pituitary suppression with a GnRHa
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Abstract
It has been clearly established that lipid-lowering treatments [such as 3-hydroxyl-3-methylglutamyl coenzyme A reductase inhibitors ('statins') or fibrates] can reduce cardiovascular events, and with one of the statins even total mortality, in high-risk populations. Intervention studies have not included the very old, but it is generally assumed that this patient group would benefit from these treatments to an extent similar to younger patients. Worries about the associations seen in observational studies between low cholesterol levels and cancer, cerebral haemorrhage or mood and behaviour change have been largely overcome by findings from the latest large drug intervention trials, which do not show any increase in these conditions with statin or fibrate treatments. The common adverse effects associated with these drugs are relatively mild and often transient in nature. Potentially more serious adverse effects, which are more clearly related to drug treatment and are probably dose-dependent, include elevations in hepatic transaminase levels and myopathy; however, these effects are uncommon and generally resolve rapidly when treatment is stopped. The risk of myopathy with fibrate treatment is increased in patients with renal impairment, and the risk of myopathy with statin treatment increases with co-administration of drugs that inhibit statin metabolism or transport. Other adverse effects are related to specific drugs, for example, clofibrate is associated with an increased risk of gallstones. Studies in elderly patients have not shown an increased risk of adverse effects with lipid-lowering drugs compared with younger patients, but in clinical practice there may be some increased risk, particularly with regards to drug interactions. Therefore, lipid-lowering drugs should be administered with extra caution to elderly patients.
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Lam TP, Irwin M, Chow LWC, Chan P. Early introduction of clinical skills teaching in a medical curriculum--factors affecting students' learning. MEDICAL EDUCATION 2002; 36:233-40. [PMID: 11879513 DOI: 10.1046/j.1365-2923.2002.01142.x] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
OBJECTIVE To evaluate the effects of the early introduction of clinical skills teaching on students' learning following an overhaul of the curriculum of a traditional Asian medical school. METHODS Randomly selected medical students in Year I and II were invited to participate in 30 focus group interviews while all students were asked to assist with the questionnaire survey. Most students were contacted personally to help them understand the objectives of the study. Confidentiality was emphasised and a non-faculty interviewer was recruited for the interviews. RESULTS Two hundred and eight of Year I/Year II students attended the lunchtime focus group interviews (response rate=86.7%) while 252 (73.5%) students returned the questionnaire. The majority of them (87%) agreed or strongly agreed that it was good to introduce clinical skills in the early years of the curriculum. They reflected that the course enhanced their learning interest and made them feel like doctors. They also made many constructive suggestions on how the course could be improved during the interactive focus group interviews so that the negative effects could be minimised. CONCLUSION It is useful to introduce clinical skills in the early years of a medical curriculum. A comprehensive course evaluation, using both quantitative and qualitative methods, helps to collect useful information on how the course can be improved.
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Dixon JM, Venizelos B, Chan P. Latissimus dorsi mini-flap: a technique for extending breast conservation. Breast 2002; 11:58-65. [PMID: 14965647 DOI: 10.1054/brst.2001.0312] [Citation(s) in RCA: 72] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2001] [Accepted: 03/30/2001] [Indexed: 11/18/2022] Open
Abstract
The latissimus dorsi (LD) flap was first used in patients for breast reconstruction in 1896. More recently it has been used to fill defects after quadrantectomy or very wide excision. We have developed a two stage procedure for excision of large breast cancers which would otherwise require mastectomy. The first stage is a wide excision of the cancer without removal of the overlying skin. Thirty patients with large localized operable breast cancer underwent wide local excision followed 5 to 10 days later in 25 patients who had clear histological margins by an axillary dissection with transfer of the LD muscle and overlying fat into the defect in the breast (mini-flap). The cosmetic outcome of these 25 patients who underwent mini-flap were compared with age matched patients having a standard wide local excision and axillary node clearance or mastectomy and immediate breast reconstruction. The volume of tissue excised in patients having their defects filled by LD mini-flap was significantly greater than those women undergoing standard wide excision, p<0.001. Compared with patients who had a mastectomy and immediate breast reconstruction, patients who had mini-flaps reported a better treated breast shape, p=0.04, a greater resemblance to the opposite breast, less self consciousness and less change in attitude of their spouse, p=0.03 and they were more likely to choose the same operation in future compared with patients having immediate whole breast reconstruction, p=0.02. Results as rated by patients in the mini-flap group were similar to those women treated by standard wide local excision. Only one patient in the mini-flap group felt sexually inhibited. When wide local excision and LD mini-flap is performed as a two stage procedure, it is an oncologically safe technique and extends breast conservation to women with larger tumours. The cosmetic outcomes appear better than those following the alternative of mastectomy and immediate breast reconstruction.
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Choksy S, El-Wajeh Y, Chan P. Vascular 12. Br J Surg 2002. [DOI: 10.1046/j.1365-2168.89.s.1.33_8.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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295
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Chen YJ, Chen SA, Chen YC, Yeh HI, Chan P, Chang MS, Lin CI. Effects of rapid atrial pacing on the arrhythmogenic activity of single cardiomyocytes from pulmonary veins: implication in initiation of atrial fibrillation. Circulation 2001; 104:2849-54. [PMID: 11733406 DOI: 10.1161/hc4801.099736] [Citation(s) in RCA: 206] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND Pulmonary veins (PVs) are important sources of paroxysmal atrial fibrillation. Long-term rapid atrial pacing (RAP) changes atrial electrophysiology and facilitates the maintenance of atrial fibrillation. It is not clear whether RAP alters the arrhythmogenic activity of PVs. The purpose of this study was to isolate single PV cardiomyocytes from control and RAP dogs and evaluate their electrophysiological characteristics. METHODS AND RESULTS The action potential and ionic currents were investigated in PV cardiomyocytes from control and long-term (6 to 8 weeks) RAP (780 bpm) dogs by use of the whole-cell clamp technique. Dissociation of PVs yielded rod-shaped single cardiomyocytes without (n=91, 60%) or with (n=60, 40%) pacemaker activity. Compared with the control group, the RAP dog PV cardiomyocytes had faster beating rates (0.86+/-0.28 versus 0.45+/-0.07 Hz, P<0.05) and shorter action potential duration. The RAP dog PV cardiomyocytes with pacemaker activity have a higher incidence of delayed (59% versus 7%, P<0.001) or early (24% versus 0%, P<0.005) after depolarization. The RAP dog PV cardiomyocytes with pacemaker activity had smaller slow inward and transient outward but larger transient inward (0.017+/-0.004 versus 0.009+/-0.002 pA/pF, P<0.05) and pacemaker (0.111+/-0.019 versus 0.028+/-0.008 pA/pF, P<0.001) currents. The RAP dog PV cardiomyocytes without pacemaker activity had only smaller slow inward and transient outward and larger pacemaker currents. CONCLUSIONS PVs contain multiple cardiomyocytes with distinct electrophysiological characteristics. RAP changes the electrophysiological characteristics and arrhythmogenic activity of PVs.
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Lee CN, Wong KL, Liu JC, Chen YJ, Cheng JT, Chan P. Inhibitory effect of stevioside on calcium influx to produce antihypertension. PLANTA MEDICA 2001; 67:796-799. [PMID: 11745013 DOI: 10.1055/s-2001-18841] [Citation(s) in RCA: 69] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Stevioside is a sweet-tasting glycoside occurring abundantly in the leaves of Stevia rebaudiana (Compositae). It has been used popularly in Japan and Brazil as a sugar substitute for decades. Previous study has shown that it lowered blood pressure in spontaneously hypertensive rats (SHRs) when administered intravenously. This study shows that intraperitoneal injection of stevioside 25 mg/kg also has antihypertensive effect in SHRs. In isolated aortic rings from normal rats, stevioside could dose-dependently relax the vasopressin-induced vasoconstriction in both the presence and absence of endothelium. However, stevioside had no effect on phenylephrine- and KCl-induced phasic vasoconstriction. In addition, stevioside lost its influence on vasopressin-induced vasoconstriction in Ca(2+)-free medium. The results indicate that stevioside caused vasorelaxation via an inhibition of Ca(2+) influx into the blood vessel. This phenomenon was further confirmed in cultured aortic smooth muscle cells (A7r5). Using 10(-5) M methylene blue for 15 min, stevioside could still relax 10(-8) M vasopressin-induced vasoconstriction in isolated rat aortic rings, showing that this vasorelaxation effect was not related to nitric oxide. The present data show that the vasorelexation effect of stevioside was mediated mainly through Ca(2+) influx inhibition.
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Cseh S, Corselli J, Chan P, Bailey L. Controlled ovarian stimulation and ultrasound guided follicular aspiration in the baboon (Papio cynocephalus anubis). REPRODUCTION, NUTRITION, DEVELOPMENT 2001; 41:531-4. [PMID: 12126298 DOI: 10.1051/rnd:2001107] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
The objective of this study was to investigate whether baboon females respond to an ovarian stimulation protocol incorporating pituitary suppression with a GnRH agonist (GnRHa) and highly purified human FSH (hphFSH) with follicular development and oocyte maturation. An ovulation induction protocol was applied to 5 adult female baboons with a history of regular menstrual cycles (33-34 days). A long-acting GnRHa implant containing goserelin acetate was placed s.c. on days 22-24 of their menstrual cycle. Daily hphFSH (75 IU im) treatments were started approximately 10 days following menses. When the majority of the follicles were > or = 5 mm in diameter and the E2 levels had reached a maximum, hCG (2000 IU i.m.) was administered to induce final maturation of the oocytes and ovulation. 30 to 34 h after hCG administration, transabdominal follicular aspiration was performed using a variable frequency transvaginal transducer with ultrasound. A total of 71 oocytes were collected (average: 17). 91% of the oocytes were morphologically normal indicating that they were appropriate for in vitro insemination.
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298
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Ma Q, Chan P, Yang J. [Association between DLST gene polymorphism and Alzheimer's disease]. ZHONGHUA YI XUE ZA ZHI 2001; 81:1246-8. [PMID: 11825528] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/23/2023]
Abstract
OBJECTIVE To investigate the association between the polymorphic alleles of dihydrolipoamide succinyltransferase (DLST) gene cDNA at position A19117G in intron 13 and C19183T in exon 14 and the risk for sporandic Alzheimer's disease (SAD). METHODS The polymorphism of DLST gene was detected using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) techniques in 105 patients with sporadic Alzheimer disease and 109 normal controls. RESULTS The frequency of AT/AC genotype was found to be significantly higher in SAD patients (21%) than in controls (10%) with an odds ratio of 2.36 (P < 0.05). The frequencies of AC/AC, AT/AT genotypes and AC allele were slightly decreased in cases with SAD as compared with controls. While the frequencies of the GC/GC genotype and GC allele were slightly higher in SAD patients than in controls. However, these differences were not statistically significant (P > 0.05). CONCLUSION The AT/AC genotype of DLST gene is associated with an increased risk for SAD.
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Figueroa KP, Chan P, Schöls L, Tanner C, Riess O, Perlman SL, Geschwind DH, Pulst SM. Association of moderate polyglutamine tract expansions in the slow calcium-activated potassium channel type 3 with ataxia. ARCHIVES OF NEUROLOGY 2001; 58:1649-53. [PMID: 11594924 DOI: 10.1001/archneur.58.10.1649] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
BACKGROUND The small-conductance calcium-activated potassium channel gene (hSKCa3) contains 2 CAG repeats, 1 of which is highly polymorphic. Although this repeat is not pathologically expanded in patients with schizophrenia, some studies have suggested an allelic association with schizophrenia. CAG expansions in other genes such as the alpha1 subunit of a brain-specific P/Q-type calcium channel gene cause spinocerebellar ataxia type 6, whereas the length of the CAG repeat in the RAI1 gene modifies the age of onset of spinocerebellar ataxia type 2. OBJECTIVES To evaluate expansions in the hSKCa3 polyglutamine domain as causative for ataxia, and to study the association between the length of the polyglutamine repeat and the presence of ataxia. METHODS We analyzed this repeat in 122 patients with autosomal dominant cerebellar ataxia, or sporadic ataxia, and compared allele distribution with 750 alleles seen in 2 healthy control groups and 172 alleles in patients with Parkinson disease. RESULTS The distribution of alleles in ataxia patients and controls was significantly different by Wilcoxon rank test (P <.001). Twenty-two or more polyglutamine tracts were more common in ataxia patients compared with controls by chi2 analysis (P<.001). CONCLUSION Longer stretches of polyglutamines in a human potassium channel are not causative for ataxia, but they are associated with the presence of ataxia. There is no association with the presence of Parkinson disease.
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Furrer H, Chan P, Weber R, Egger M. Increased risk of wasting syndrome in HIV-infected travellers: prospective multicentre study. Trans R Soc Trop Med Hyg 2001; 95:484-6. [PMID: 11706654 DOI: 10.1016/s0035-9203(01)90011-2] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
HIV-infected patients from moderate regions who travel in tropical countries may experience clinical disease progression due to exposure to bacteria (including mycobacteria), fungi and parasites. In the Swiss HIV Cohort Study we examined the hypothesis that travelling increases the risk of tuberculosis, wasting syndrome, cryptosporidiosis, isosporiasis, cryptococcosis, coccidiomycosis, histoplasmosis and Salmonella septicaemia. A total of 4549 participants were included (in 1988-98) of whom 596 (13.1%) travelled at least once. During 16,800 person-years of follow-up 231 patients developed at least 1 of the diseases of interest. Wasting syndrome was the only diagnosis significantly associated with travelling (hazard ratio 2.16, 95% confidence interval 1.09 to 4.30). The risk of wasting syndrome ('slim disease') should be taken into account when counselling HIV-infected patients intending to travel in tropical regions.
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