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Chen HH, Wexner SD, Iroatulam AJ, Pikarsky AJ, Alabaz O, Nogueras JJ, Nessim A, Weiss EG. Laparoscopic colectomy compares favorably with colectomy by laparotomy for reduction of postoperative ileus. Dis Colon Rectum 2000; 43:61-5. [PMID: 10813125 DOI: 10.1007/bf02237245] [Citation(s) in RCA: 104] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
PURPOSE The aim of this study was to compare the length of postoperative ileus in patients undergoing colectomy by either laparotomy or laparoscopy. METHODS A total of 166 patients were studied. These patients were divided into two groups: Group 1, in which colectomy was done laparoscopically, and Group 2, consisting of patients undergoing laparotomy. Both groups contained 83 patients who were matched for disease severity, indications for surgery, and procedure. Indications for surgery included sigmoid diverticulitis in 12 (14 percent) patients, polyps in 22 (27 percent), Crohn's disease in 21 (25 percent), colorectal cancer in 11 (13 percent), stoma reversal in 8 (10 percent), rectal prolapse in 3 (4 percent), and other indications in 6 (7 percent) in each group. Operations were colectomy with anastomosis (42 ileocolic, 26 colorectal, 6 colocolic, 4 ileorectal, and 2 ileal J pouch) or without anastomosis (3 abdominoperineal resections) performed by the same surgeons during the same time period January 1993 to October 1996). The nasogastric tube was removed from all patients immediately after surgery in both groups. All patients received a clear liquid diet on the first postoperative day, followed by a regular diet as tolerated. The nasogastric tube was reinserted if two or more episodes of emesis of more than 200 ml occurred in the absence of bowel movement. Patients were discharged from the hospital when tolerating a regular diet without evidence of ileus. Statistical analysis was performed using unpaired t-test and Fisher's exact probability test. RESULTS The male-to-female ratio was 38 to 45 in both groups. A total of 10 (12 percent) and 23 (28 percent) patients in Group 1 and Group 2 had emesis (P = 0.02), and the rate of nasogastric tube reinsertion was 5 (6 percent) and 13 (16 percent), respectively (P > 0.05). There were significant differences between Groups 1 and 2 relative to the lengths of ileus (3.5 +/- 1.3 vs. 5.4 +/- 1.7 days, respectively; P < 0.001), hospitalization (6.6 +/- 3.3 vs. 8.1 +/- 2.5 days, respectively; P < 0.002), and operative time (170 +/- 60 vs. 114 +/- 46 minutes, respectively; P < 0.001). The morbidity rate was 16 (19.2 percent) and 18 (21.6 percent) in the laparoscopy and laparotomy groups, respectively. CONCLUSIONS Although early oral intake is safe and can be tolerated by 84 percent of patients after colectomy by laparotomy, laparoscopic colectomy reduced the lengths of both postoperative ileus and hospitalization.
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Nixon R, Prevost TC, Duffy SW, Tabar L, Vitak B, Chen HH. Some random-effects models for the analysis of matched-cluster randomised trials: application to the Swedish two-county trial of breast-cancer screening. JOURNAL OF EPIDEMIOLOGY AND BIOSTATISTICS 2000; 5:349-58. [PMID: 11234739] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 04/16/2023]
Abstract
BACKGROUND In the Swedish two-county trial women aged 40-74 years from two counties in Sweden were randomised to invitation to mammographic screening for breast cancer. METHODS This paper uses random effects logistic regression models to analyse recent data from the trial. The analysis accounts for the structure of the trial, where small geographical units are randomised within larger geographical strata (blocks of two or three small units that are socio-economically similar). RESULTS Fixed effects and a variety of random effects models show a strong degree of agreement and yield a significant 29% or 30% reduction in breast-cancer mortality. DISCUSSION Fixed effects and random effects models agree for this example, because heterogeneity both between strata and within strata between clusters is small and because the effect of treatment does not vary much in different strata.
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Demirkan F, Chen HC, Wei FC, Chen HH, Jung SG, Hau SP, Liao CT. The versatile anterolateral thigh flap: a musculocutaneous flap in disguise in head and neck reconstruction. BRITISH JOURNAL OF PLASTIC SURGERY 2000; 53:30-6. [PMID: 10657446 DOI: 10.1054/bjps.1999.3250] [Citation(s) in RCA: 135] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
In search of an alternative soft tissue free flap donor site to radial forearm flap and rectus abdominis flap in head and neck reconstruction, we used the anterolateral thigh flap for reconstruction of various defects in the head and neck in 59 patients. The aim was to demonstrate the versatility of this donor site and propose a new approach to achieve a safer flap dissection. With the exception of three cases, all defects resulted from excision of malignant tumours. The defects were categorised as full thickness defects of the mandible (33.9%), full thickness defects of the cheek (52.5%) and others (13.6%). During the flap dissection a direct septocutaneous pedicle was observed in 12% of the cases. In the remaining cases there were only musculocutaneous perforators and the flaps were raised either as a split vastus lateralis musculocutaneous flap (72%) or as a perforator flap (16%), depending on the required thickness. Total flap survival was 96.7% with one total and one partial failure and two re-explorations (3.3%). The mean follow-up time was 7.1 months (range: 1-12 months). In conclusion, the anterolateral thigh flap is a versatile and dependable flap that can be adapted to any type of defect by modifying the flap design and composition. It should be considered to be a musculocutaneous flap of the vastus lateralis muscle that can also be raised as a perforator flap. When harvested and used in this context, the flap dissection becomes very safe and consistent, nullifying the only major disadvantage associated with this donor site.
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Chen HH, Schirger JA, Chau WL, Jougasaki M, Lisy O, Redfield MM, Barclay PT, Burnett JC. Renal response to acute neutral endopeptidase inhibition in mild and severe experimental heart failure. Circulation 1999; 100:2443-8. [PMID: 10595958 DOI: 10.1161/01.cir.100.24.2443] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND Neutral endopeptidase 24.11 (NEP) is a metalloprotease that is localized in the greatest abundance in the kidney and degrades natriuretic peptides, such as atrial natriuretic peptide (ANP). Mild congestive heart failure (CHF) is characterized by increases in circulating ANP without activation of the renin-angiotensin-aldosterone system (RAAS) or sodium retention. In contrast, severe CHF is characterized by sodium retention and coactivation of both ANP and the RAAS. METHODS AND RESULTS We defined the acute cardiorenal actions of the NEP inhibitor candoxatrilat (8 microg. kg(-1). min(-1)) in 4 groups of anesthetized dogs (normal, n=8; mild CHF, n=6; severe CHF, n=5; and severe CHF with chronic AT(1) receptor antagonism, n=5). Mild CHF was produced by rapid ventricular pacing at 180 bpm for 10 days and severe CHF at 245 bpm for 10 days. In mild CHF, urinary sodium excretion and glomerular filtration rate were greatest in response to acute NEP inhibition compared with the response in either control animals or those with severe CHF. Furthermore, an increase in glomerular filtration rate was observed only in mild CHF in association with increases in renal blood flow and decreases in renal vascular resistance and distal tubular sodium reabsorption. Urinary ANP and cGMP excretion, markers for renal biological actions of ANP, were greatest in mild CHF. The renal actions observed in mild CHF were attenuated in severe CHF and not restored by chronic AT(1) receptor antagonism. CONCLUSIONS The results of the present study demonstrate that acute NEP inhibition in mild CHF results in marked increases in renal hemodynamics and sodium excretion that exceed that observed in control animals and severe CHF. These studies underscore the potential therapeutic role for NEP inhibition to enhance renal function in mild CHF, an important phase of CHF that is marked by selective activation of endogenous ANP in the absence of an activated RAAS.
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Chen HH, Iroatulam AJ, Alabaz O, Joo JS, Weiss EG, Nogueras JJ, Wexner SD. Laparoscopic colectomy is superior to laparotomy for reduction of disability in patients with colorectal adenoma. CHANGGENG YI XUE ZA ZHI 1999; 22:586-92. [PMID: 10695205] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/15/2023]
Abstract
BACKGROUND This study was to evaluate disability after laparoscopic colectomy in patients with colorectal adenomas as compared to disability after laparotomy. METHODS Patients who underwent laparoscopic colectomy for colorectal adenoma were compared to patients who underwent laparotomy for the same problem by the same surgeons during the same time period in Cleveland Clinic Florida. A standard questionnaire was used to assess disability which included the number of days to return to partial activity, full activity, and work. RESULTS Twenty-nine patients who underwent laparoscopy were compared with 31 patients who underwent laparotomy. There were no significant differences in age (70.4 vs 72.5 years) (p = 0.405) or gender (M:F 13:16 vs 20:11) (p = 0.126) between the laparoscopy and laparotomy groups. The operative time was longer for the laparoscopy group than the laparotomy group: 170 vs 131 minutes (p = 0.014). However, the duration of postoperative ileus, hospitalization, time until return to partial activity, time until return to full activity, and time off of work were significantly shorter in the laparoscopy group than in the laparotomy group: 3.3 vs 5.2 days, 6.2 vs 8.7 days, 2.3 vs 4.2 weeks, 4.4 vs 9.3 weeks, and 3.7 vs 7.3 weeks, respectively (p < 0.041 for all). Although the incidence of postoperative complications was not significantly different (24% for laparoscopy vs 29% for laparotomy, p = 0.325), the incidence of postoperative prolonged ileus was statistically significantly lower in the laparoscopy group (3% vs 26%, p = 0.027). CONCLUSION Laparoscopic colectomy for patients with colorectal adenoma can reduce postoperative ileus, postoperative hospitalization, and disability in terms of a quicker return to partial activity, full activity, and employment. Laparoscopic colectomy should be considered for all patients who have colorectal adenomas which require resection.
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Tabar L, Chen HH, Duffy SW, Krusemo UB. Primary and adjuvant therapy, prognostic factors and survival in 1053 breast cancers diagnosed in a trial of mammography screening. Jpn J Clin Oncol 1999; 29:608-16. [PMID: 10721943 DOI: 10.1093/jjco/29.12.608] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND As mammographic screening becomes more widespread, larger numbers of tumours are diagnosed while small and node negative. METHODS We examined detection mode, tumour size, node status, histological type, therapy and outcome in 1053 breast cancers diagnosed in one county of the Swedish Two-County Trial of mammographic screening for breast cancer. RESULTS Of patients undergoing total mastectomy with axillary dissection, 65% were found to be node negative. For tumours of size 1-9 mm, 95% were node negative. The major effects on survival were tumour size, node status and histological type. Primary adjuvant therapy had no significant association with survival. CONCLUSIONS The advent of mammography has substantially enhanced the possibilities for less radical treatment. There is an urgent need for therapeutic trials utilizing mammographic-pathological correlations to ascertain in advance which tumours can and which cannot benefit from more radical therapy.
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Chen HH, Chen JT, Ho WL. Clinicopathologic and cytologic features of a metanephric adenoma of the kidney: a case report. ZHONGHUA YI XUE ZA ZHI = CHINESE MEDICAL JOURNAL; FREE CHINA ED 1999; 62:896-900. [PMID: 10634005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/15/2023]
Abstract
Metanephric adenoma is a recently described rare and benign renal neoplasm. Our patient, a 37-year-old woman, suffered from flank pain for five months and was found to have a renal mass. Ultrasound, computerized tomography and angiography findings were consistent with a hypovascular renal cyst. Wilms' tumor was the initial misdiagnosis, based on needle biopsy and aspiration cytology. A radical nephrectomy was performed. Histologically, the tumor was well defined and was composed of uniform small cells arranged in a solid, tubular or rosette-like pattern. The prognosis is good for metanephric adenoma. The tumor was first considered a benign counterpart of papillary carcinoma or Wilms' tumor; however, recent cytogenetic evidence suggested that the tumor might be related to papillary adenoma and papillary renal cell carcinoma. The clinical, radiologic, histologic and cytologic features presented here should help to promote the correct preoperative diagnosis and to avoid unnecessary aggressive treatment.
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Tabar L, Vitak B, Chen HH, Prevost TC, Duffy SW. Update of the Swedish Two-County Trial of breast cancer screening: histologic grade-specific and age-specific results. SWISS SURGERY = SCHWEIZER CHIRURGIE = CHIRURGIE SUISSE = CHIRURGIA SVIZZERA 1999; 5:199-204. [PMID: 10546517 DOI: 10.1024/1023-9332.5.5.199] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
UNLABELLED The benefit of mammographic screening in reducing mortality from breast cancer is well established. Questions remain with respect to the magnitude of the long-term benefit of modern mammography screening, age specific benefits and the timing of these, and histology specific effects. METHODS The Swedish Two-County Trial was set up in 1977, with 77,080 women aged 40-74 randomised to invitation to mammographic screening for breast cancer (active study population, ASP) and 55,985 women randomised to no invitation (passive study population, PSP). There is now follow-up for mortality to 31 December 1996, approximately 18 years average follow-up. We investigated the effect of invitation of screening on breast cancer mortality and incidence of advanced tumours by age group (40-49 and 50-74) and histologic type. In addition we estimated progression rates by histologic grade using markov chain models. RESULTS A significant 29% reduction in breast cancer mortality was observed in association with invitation to screening (relative risk = 0.71, 95% confidence interval 0.60-0.83), maintaining the effect observed at previous stages of follow-up. Age-specific analyses show a smaller and later mortality benefit in women aged 40-49. This is related to the fact that there is a considerable benefit from early detection in terms of mortality from aggressive, poorly differentiated cancers in women aged 50-74, whereas the major effect in women aged 40-49 is on the less aggressive tumours of good or intermediate differentiation. Among women aged 50-74, the incidence of grade III tumours in the ASP is significantly lower than in the PSP, but this is not the case for women aged 40-49. This is related to the greater prevalence and rapidity of progression with respect to histologic grade, as evidenced by the results of markov chain models and the proportions of grade III tumours by time since last screen. CONCLUSIONS The substantial and significant mortality benefit of invitation to mammographic screening in women aged 40-74 is maintained at 18 years of follow-up. To achieve a substantial mortality benefit at an early stage in the screening program in women aged under 50 years, an interscreening interval of 12-18 months would be required.
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Wu MP, Chen HH, Yen EY, Tsai SC, Mo LR. A potential complication of laparoscopy--the surgeon's herniated cervical disk. THE JOURNAL OF THE AMERICAN ASSOCIATION OF GYNECOLOGIC LAPAROSCOPISTS 1999; 6:509-11. [PMID: 10548715 DOI: 10.1016/s1074-3804(99)80021-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/13/2023]
Abstract
Almost all operations that were traditionally performed by open laparotomy operations can be done laparoscopically; however, surgeons may experience several negative health effects. A 37-year-old gynecologic laparoscopist had a herniated intervertebral disk at C5-6 level. Due to a negative trauma history, a possible explanation may be the nonergonomic posture that he held while performing laparoscopic surgery for many hours. To reduce the risk of this complication, we recommend that surgeons' spatial orientation and hand-eye coordination for laparoscopy be improved by sequential phases of training.
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Tseng CS, Chung CW, Chen HH, Wang SS, Tseng HM. Development of a robotic navigation system for neurosurgery. Stud Health Technol Inform 1999; 62:358-9. [PMID: 10538386] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/14/2023]
Abstract
This paper presents a robotic navigation system for image-guided neurosurgery, which can be applied to the treatment of Parkinson's disease and biopsy of brain tumor. The system integrates a computer for real-time display of brain anatomy, a magnetic tracking device for measuring the positions and orientations of surgical instruments, and a robot manipulator for guiding surgical instruments to the preplanned positions and orientations. The computer display of brain anatomy offers a convenient tool for surgeons to diagnose brain disease and to plan safe surgical paths; while the tracking device assists the robot manipulator to automatically guide surgical instruments to the preplanned direction. The registrations among the tracking device, the image system, and the robot are completed on the base of coordination mappings of external markers. An experiment of using a skull model for simulating a robotic biopsy of brain tumor has been done to verify the performance of the navigation system. The result shows that the system can accomplish a positioning accuracy around 2 mm.
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Chen HH, Burnett JC. The natriuretic peptides in heart failure: diagnostic and therapeutic potentials. PROCEEDINGS OF THE ASSOCIATION OF AMERICAN PHYSICIANS 1999; 111:406-16. [PMID: 10519161 DOI: 10.1111/paa.1999.111.5.406] [Citation(s) in RCA: 129] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
The natriuretic peptides are a group of structurally similar but genetically distinct peptides that have diverse actions in cardiovascular, renal, and endocrine homeostasis. Atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP) are of myocardial cell origin and C-type natriuretic peptide (CNP) is of endothelial origin. ANP and BNP bind to the natriuretic peptide-A receptor (NPR-A), which, via 3',5'-cyclic guanosine monophosphate (cGMP), mediates natriuresis, vasodilation, renin inhibition, antimitogenesis, and lusitropic properties. CNP lacks natriuretic actions but possesses vasodilating and growth-inhibiting actions via the guanylyl cyclase-linked natriuretic peptide-B receptor (NPR-B). All three peptides are cleared by the natriuretic peptide-C receptor (NPR-C) and are degraded by the ectoenzyme neutral endopeptidase 24.11 (NEP), both of which are widely expressed in the kidneys, lungs, and the vascular wall. Congestive heart failure (CHF) represents a pathological state in which the activation of the natriuretic peptides exceeds those of all other states. In this brief review, we will attempt to provide an update on important issues regarding natriuretic peptides in CHF, with a focus on their functional importance as a beneficial humoral response in asymptomatic left ventricular dysfunction (LVD), the mechanisms of natriuretic peptide hyporesponsiveness in severe heart failure, the diagnostic and prognostic significance of the natriuretic peptides in CHF, and the therapeutic potential of the natriuretic peptides in this multiorgan syndrome.
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Lisy O, Jougasaki M, Heublein DM, Schirger JA, Chen HH, Wennberg PW, Burnett JC. Renal actions of synthetic dendroaspis natriuretic peptide. Kidney Int 1999; 56:502-8. [PMID: 10432389 DOI: 10.1046/j.1523-1755.1999.00573.x] [Citation(s) in RCA: 90] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
BACKGROUND Dendroaspis natriuretic peptide (DNP), recently isolated from the venom of the green Mamba snake Dendroaspis angusticeps, is a 38 amino acid peptide containing a 17 amino acid disulfide ring structure similar to that of atrial natriuretic peptide (ANP), brain natriuretic peptide (BNP), and C-type natriuretic peptide (CNP). DNP-like immunoreactivity (DNP-LI) was reported to be present in human plasma and atrial myocardium and to be elevated in human congestive heart failure. Although previously named DNP, it remains unknown if DNP is natriuretic or if is it present in canine plasma, urine, and atrial myocardium. METHOD Studies were performed in vivo in anesthetized dogs (N = 6) using intravenous infusion of synthetic DNP at 10 and 50 ng/kg/min. Employing a sensitive and specific radioimmunoassay for DNP, the presence of DNP-like peptide was assessed in the canine plasma and urine before, during, and following the administration of exogenous synthetic DNP. Additionally, we performed immunohistochemical studies using the indirect immunoperoxidase method with polyclonal DNP antiserum in normal atrial myocardium (N = 10). Atrial concentrations of DNP-LI were also assessed. RESULTS We report that DNP is markedly natriuretic and diuretic, which, like ANP and BNP, is associated with the increase in urinary and plasma cGMP. DNP-like peptide is also detected in canine plasma, urine, and atrial myocardium. CONCLUSION These studies establish that DNP is a potent natriuretic and diuretic peptide with tubular actions linked to cGMP and that DNP may play a physiological role in the regulation of sodium excretion.
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Abstract
Although the response properties and synaptic projections of muscle sensory neurons have been studied extensively, relatively little is known about how these sensory neurons develop their unique phenotypes during embryonic life. The explosion of new information on neurotrophins, however, has revealed that neurotrophin 3 (NT3) is critically involved in several aspects of this development, including the initial differentiation, survival, and perhaps even the terminal arborizations of muscle sensory neurons within the spinal cord. The ETS family of transcription factors, recently shown to be expressed in these sensory neurons, may help specify their choice of synaptic targets in the central nervous system.
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Hung YC, Lee EJ, Wang LC, Chen HH, Yan JJ, Yu CY. Mixed germ cell tumor presenting as intratumoral hemorrhage: report of a case originated from the pineal region. Kaohsiung J Med Sci 1999; 15:498-503. [PMID: 10518367] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/14/2023] Open
Abstract
A 17-year-old male patient was brought to our clinic because of sudden onset of headache, vomiting, followed by transient loss of consciousness during a strenuous exercise. Neurologic examinations revealed that the patient had severe sensorimotor and brain stem dysfunction. Examinations of cranial CT and MR imaging showed a huge heterogeneously enhanced tumor originated from the pineal region with tumoral hemorrhage. The tumor markers were found to be high in AFP but not the beta-HCG and CEA. A clinical diagnosis highly suggestive of germ cell tumor was made. Prior to the planned emergency radiation therapy, he received an external ventricular drainage (EVD) and open biopsy of the tumor. Due to a postoperative complication of cerebellar hemorrhage observed 8 hours later, another maneuver was therefore required to extirpate the pineal tumor and cerebellar hematoma. The histological diagnosis proved to be a mixed germ cell tumor with tumoral hemorrhage. Spontaneous intratumoral hemorrhage in germ cell tumor of the pineal region is rare, probably due to compromised venous circulation within the tumor. The bleeding propensity, which may contribute to the formation of cerebellar hematoma, warrants a special attention when a biopsy procedure is to be performed.
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Chang SJ, Chuang HJ, Chen HH. Vitamin B6 down-regulates the expression of human GPIIb gene. J Nutr Sci Vitaminol (Tokyo) 1999; 45:471-9. [PMID: 10575637 DOI: 10.3177/jnsv.45.471] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Glycoprotein IIb (GPIIb) is the alpha-subunit of the platelet membrane receptor GPIIb/IIIa, which plays a major role in platelet aggregation. Vitamin B6 has been reported to be an antiaggregative agent, although its mechanism is not well known. To understand the molecular mechanism of vitamin B6 on antiaggregation, we analyzed the effects of various forms of vitamin B6 on the expression of human GPIIb promoter using chloramphenicol acetyl transferase (CAT) as the reporter gene. The GPIIb promoter region was amplified by polymerase chain reaction (PCR), cloned into pBLCAT3 to drive the CAT reporter gene and transfected into human erythroleukemia (HEL) cells. Transient expression of the GPIIb promoter was determined after transfected cells were treated with 1 microM pyridoxine (PN), pyridoxal (PL), pyridoxal-5-phosphate (PLP), or 4-deoxypyridoxine (4-dex) for 48 h. Our results show that the GPIIb promoter activity was down-regulated to 54, 35 and 63% in the presence of PN, PL and PLP, respectively, as compared to an untreated control whose promoter activity was 100%. However, no adverse effect on GPIIb promoter was detected by 4-dex, which is an antagonist of vitamin B6. The down-regulation effect of vitamin B6 on GPIIb promoter activity may lead to a reduction of GPIIb protein expression and thus be detrimental to platelet aggregation.
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Iroatulam AJ, Chen HH, Potenti FM, Parameswaran S, Wexner SD. Laparoscopic colectomy yields similar morbidity and disability regardless of patient age. Int J Colorectal Dis 1999; 14:155-7. [PMID: 10460906 DOI: 10.1007/s003840050202] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
This study compared the outcome factors of morbidity and the length of disability in older and younger patients following laparoscopic colorectal surgery. All patients undergoing laparoscopic segmental resection during the study period were included. Morbidity was determined by reviewing the medical records, and disability by a patient-administered questionnaire. The series was divided into two age cohorts (</=64 and >/=65 years), which did not differ significantly in gender or type of procedure. Between these two groups we found no significant differences in mean duration of ileus (3.3 days in both groups), the mean length of hospitalization (5.7 vs. 6.3 days, respectively), morbidity rate (18% vs. 21%), or time until returning to partial activity (1.6 vs. 1.6 weeks) or to full activity (3 vs. 2 weeks). Our findings demonstrate that neither the morbidity rate nor the disability period after laparoscopic techniques differ between elderly and younger patients. We therefore endorse the use of laparoscopy regardless of patient age.
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Chao JS, Wei LY, Huang MC, Liang SC, Chen HH. Genotoxic effects of triphenyltin acetate and triphenyltin hydroxide on mammalian cells in vitro and in vivo. Mutat Res 1999; 444:167-74. [PMID: 10477351 DOI: 10.1016/s1383-5718(99)00082-0] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Two organotin pesticides, triphenyltin acetate (TPTA) and triphenyltin hydroxide (TPTH), were evaluated for their ability to induce micronuclei (MN) and sister chromatid exchange (SCE) in vitro using cultured Chinese hamster ovary (CHO) cells and in vivo BALB/c mouse erythrocytes. Both pesticides induced a dose-dependent increase but only TPTH induced a significant increase in MN at the highest dose (150 ng/ml) tested in CHO cells. With adding S9 microsomal fractions, both pesticides induced a meaningful MN induction at 150 ng/ml and a dose-dependent significant increase in SCE. In vivo MN induction in erythrocytes was conducted by treating BALB/c mice orally or intraperitoneally with these pesticides either in a single or triple treatments. Oral gavage (p.o.) of TPTA resulted in a dose-related significant increase of MN induction in peripheral blood and of TPTH induced a significant increase in micronucleated reticulocyte (MNRETs) only in a single treatment. Intraperitoneal administration of TPTA or TPTH, however, resulted in meaningless random increases in MN though these increases might be attributable to toxic effects. The MNRETs levels in the treatment with both pesticides were independent to the sampling time. This study demonstrated that TPTA and TPTH was potential chromosome mutagens.
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Chen YC, Chen HH, Yeh JC. Postdialysis serum albumin is more rational than predialysis value. Nephron Clin Pract 1999; 82:284-5. [PMID: 10396005 DOI: 10.1159/000045417] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
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Pfeifer GP, Chen HH, Komura J, Riggs AD. Chromatin structure analysis by ligation-mediated and terminal transferase-mediated polymerase chain reaction. Methods Enzymol 1999; 304:548-71. [PMID: 10372381 DOI: 10.1016/s0076-6879(99)04032-x] [Citation(s) in RCA: 48] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/10/2023]
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Chen HH, Cooper A, Taylor I, Johnson CD. Effect of a microwave coagulator on implanted liver neoplasms in rats. Dig Surg 1999; 16:140-4. [PMID: 10207241 DOI: 10.1159/000018707] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/10/2022]
Abstract
An experimental study was conducted to determine the applicability of a microwave (MW) source for coagulation and dissection of metastatic tumour and liver parenchyma. Twenty PVG rats were studied after implantation of MC28 tumour cells into the liver. Eleven days later they underwent sham laparotomy (control) MW coagulation of the tumour deposit, local resection of the tumour deposit with 2 mm clearance or resection of the tumour with MW coagulation of the resection zone. The control animals all died with blood-stained ascites and heavy tumour burden in the liver. After MW coagulation, tumours disappeared in all but one rat. Local resection also led to tumour clearance in 4 of 5 rats. MW coagulation of the resection zone allowed rapid bloodless resection, and no tumour recurrence was observed after 40-89 days. We conclude that MW coagulation is a potentially useful tool for ablation of hepatic metastasis and as an adjunct to hepatic resection.
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146
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Chen HH, Prevost TC, Duffy SW. Evaluation of screening for nasopharyngeal carcinoma: trial design using Markov chain models. Br J Cancer 1999; 79:1894-900. [PMID: 10206310 PMCID: PMC2362802 DOI: 10.1038/sj.bjc.6690301] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/02/2022] Open
Abstract
In this paper, we develop a Markov chain model to estimate parameters pertaining to the natural history of nasopharyngeal carcinoma (NPC). The model is of progression from no disease to Epstein-Barr virus (EBV) infection, preclinical screen-detectable tumour and clinical tumour. We derive tentative estimates of the parameters of the model, based on limited published data, to assess the efficacy of serum screening in conjunction with clinical assessment (indirect mirror examination for NPC), for example the average duration of the preclinical screen-detectable phase is estimated as 3.1 years. We further apply these parameters to a hypothetical screening trial in the Hong Kong population to assess the efficacy of serum screening with clinical assessment by different combinations of screening regime. Results suggest: (1) there is no substantial difference between 3-yearly and 6-yearly serum screening; and (2) within the same serum screening regime annual and 3-yearly clinical assessment can prevent 33% and 28% of deaths from NPC respectively. Prediction of deaths and surrogate end points can be used to estimate the required sample size and duration for designing a randomized trial of screening for NPC. Based on these findings and power projections, we suggest a design for a randomized trial in a high incidence area such as Hong Kong.
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147
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Chen HC, Kuo YR, Hwang TL, Chen HH, Chang CH, Tang YB. Microvascular prefabricated free skin flaps for esophageal reconstruction in difficult patients. Ann Thorac Surg 1999; 67:911-6. [PMID: 10320227 DOI: 10.1016/s0003-4975(99)00152-6] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
BACKGROUND Reconstruction of the esophagus for complicated benign stricture or after resection of malignant lesion is still a challenge for surgeons. When abdominal viscera cannot be used, skin flaps are selected for esophageal reconstruction. However, skin flaps for esophageal reconstruction are notorious for leakage, and have not been widely accepted. Prefabrication before microvascular transfer to its final site can improve the result of esophageal reconstruction when skin flaps are used. METHODS Eight patients with complicated corrosive esophagitis had been treated with prefabricated skin flaps for esophageal reconstruction. The procedures are described in detail. RESULTS All patients healed well without leakage. The barium study showed smooth passage. There was no dysphasia or regurgitation after education. Pulmonary complication happened in only 1 patient. Revision for the distal anastomosis was required in 1 patient due to narrowing. When the skin tube is long, the patients need water (or soup) to facilitate swallowing and occasionally use their hand to help the food passage. This method has the following advantages: (1) healing of the long suture line before transfer to withstand the intestinal juice; (2) reliable viability in the distal part of the flap, especially when an extended length of the flap is required; (3) more length of stable tissue for two-layered, tension-free anastomosis at the junction of skin and gastrointestinal mucosa to prevent leakage; and (4) the flap can be placed in the substernal position to meet the aesthetic requirement of young patients. The disadvantage was the staged operations. However, after prefabrication the transfer becomes safe and free of leakage. The overall morbidity is minimal. CONCLUSIONS In rare situations when skin flaps are used for esophageal reconstruction, prefabrication provides advantages over conventional one-stage methods, although it needs additional procedures. This method is a combination of conventional technique and microsurgery.
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148
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Ma T, Chen HH, Ho IK. Effects of chronic lead (Pb) exposure on neurobehavioral function and dopaminergic neurotransmitter receptors in rats. Toxicol Lett 1999; 105:111-21. [PMID: 10221273 DOI: 10.1016/s0378-4274(98)00388-9] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Sprague-Dawley rats were maternally and permanently exposed to Pb (1000 ppm in their drinking water as lead acetate). Behavioral functions were examined starting at post-natal day (PN) 84. Lead exposure did not change spatial learning in the radial arm maze, but induced higher locomotor activity as observed in the open-field and in the radial arm maze. Lead treatment did not impact motor coordination. Autoradiographic analysis of brain sections indicated that Pb-exposure did produce a decrease in [125I]sulpride (D2 receptor antagonist) binding in the cerebral cortex, but not in the striatum and thalamus nucleus. No change was found in [125I]SCH-23982 (D1 receptor antagonist) binding. Since the cortical dopaminergic system is critical for cognitive processes and motor behavior, it is possible that Pb-related change in D2 receptors may mediate to it induced hyperlocomotor activity.
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149
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Cheng CK, Chen HH, Chen CS, Lee SJ. Influences of walking speed change on the lumbosacral joint force distribution. Biomed Mater Eng 1999; 8:155-65. [PMID: 10065882] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/11/2023]
Abstract
To more understand the influence of the walking speed on the spinal joint force distribution, a three-dimensional biomechanical model was used to estimate the spine loads during human gait with three different walking speeds. This previously developed and validated model included a dynamic external model and an internal model with forces of disc, 8 major muscles, 2 ligaments and 2 facet joints at L5/S1 level. A linear optimization method was used to solve the internal model to estimate the L5/S1 spinal joint force distribution. The results of five young male subjects showed that the mean peak L5/S1 disc compressive forces on the slow, preferred and fast speeds were 2.28, 2.53, 2.95 body weight, respectively. The peak forces happened right after the heel strike and before completely toe off. The facet joint forces were generally increased with the walking speed increase, too. To reduce the loads on the spine, the slow walking is then recommended for the patients with low back pain or after spinal surgery.
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150
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Chen HH. Anal manometric findings before and after hemorrhoidectomy: a preliminary report. CHANGGENG YI XUE ZA ZHI 1999; 22:25-30. [PMID: 10418206] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/13/2023]
Abstract
BACKGROUND A difference of opinion exists as to whether patients with symptomatic hemorrhoids, patients after hemorrhoidectomy, and patients with no hemorrhoids have different anal physiologies. METHODS Twenty-four patients with symptomatic hemorrhoids undergoing hemorrhoidectomy were investigated using anorectal manometry. There were 12 male and 12 female patients with a mean age of 42 years (range: 23 to 72 years). The anorectal manometry was performed one day before the operation and 8 to 12 weeks after the operation. Another normal group, comprised of 138 volunteers, was included and matched for age and gender. RESULTS The anorectal inhibitory reflex was present in all the normal group (NG), symptomatic hemorrhoid (SH), and post-hemorrhoidectomy (PH) patients. No major incontinence was noted clinically. The mean resting pressure (MRP) in the SH group (mean: 84.5 +/- 28.7 cmH2O, range: 26 to 166 cmH2O) was significantly greater than in the NG (mean: 74.4 +/- 14.9 cmH2O, range: 61 to 116 cmH2O) and the PH groups (mean: 63.7 +/- 23.6 cmH2O, range: 20 to 116 cmH2O) (p = 0.032 and 0.005, respectively). After hemorrhoidectomy, the MRP was significantly decreased compared to the normal group (p = 0.018). The other manometric data showed no statistical change in these three groups. CONCLUSION The results indicate that persons with SH have a higher MRP than normal. Overactivity of the internal sphincter muscle may be a cause rather than a result of symptomatic hemorrhoids. Compared with the SH and normal groups, the MRP was significantly decreased to prevent recurrent symptomatic hemorrhoids in the PH group. Though the MRP was significantly decreased, no major incontinence was noted after hemorrhoidectomy, and this might be due to the increase in rectal compliance and mean squeeze pressure.
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