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Biomedical subjects

Y H Ho

Publications and source records attributed to Y H Ho.

At least 37 records · Page 2Linked to original sources
PubMed2001

Prospective randomised trial comparing ayurvedic cutting seton and fistulotomy for low fistula-in-ano.

The aim of this study was to evaluate the role of ayurvedic setons in the treatment of low fistula-in-ano. One hundred and eight patients were randomised into either conventional fistulotomy (F) or ayurvedic cutting seton insertion (C). Endpoints investigated included time to wound healing and complications of surgery. Post-operative pain scores were measured daily using a visual analog scale. Anal function was compared using a continence score. Pre- and postoperative manometry and ultrasound were also performed. After exclusions, there were 54 patients in group F and 46 in group C. There were no differences in age, sex or follow-up duration between the two groups. Healing time was similar between the groups. Group C reported more pain following operation and on the first 2-4 postoperative days, but both groups experienced the same amount of pain subsequently. In conclusion, chemical seton was more painful than conventional fistulotomy in the first few days following surgery. However, there was no difference in time to wound healing, complications or functional outcome.

Adolescent↗
PubMed2001

Tumor size is irrelevant in predicting malignant potential of carcinoid tumors of the rectum.

The malignant potential and prognosis of rectal carcinoids are said to be related to tumor size. Our study assessed if size could predict the malignant potential and hence its management. All patients in the Department of Colorectal Surgery, Singapore General Hospital, who underwent surgery for rectal carcinoid tumors between February 1991 and September 2000 were analyzed. Twenty patients (11 men), median age 48 years (range, 33-77 years) were studied. Median follow-up was 40 months (range, 5-120 months). The median tumor diameter was 2.5 cm (range, 0.1-5.0 cm). Eleven patients underwent radical resection and 9 patients had local resection for a presumed benign tumor. Morbidity was 15% and postoperative death was 5%. Overall median survival was 24 months (range, 5-120 months). One patient had an anterior resection for rectal adenocarcinoma but had an incidental 0.1-cm carcinoid tumor near the resection margin which on histology was found to have carcinoid tumor metastasis to 2 out of 12 lymph nodes. In conclusion, tumor size cannot predict malignant potential as even small tumors (<1 cm) can be malignant. Accurate preoperative staging with radical surgery may be required.

Adult↗
PubMed2001

Total colectomy with ileorectal anastomosis leads to appreciable loss in quality of life irrespective of primary diagnosis.

Total colectomy with ileorectal anastomosis (TC) is a well-accepted procedure for many colonic pathologies but data on faecal incontinence and related quality of life after TC are lacking. The aims of this study were to assess the long-term bowel frequency, degree of incontinence and quality of life with respect to faecal incontinence and to compare them with the outcome for TC for different diagnostic groups. We identified 54 patients who had undergone TC at Singapore General Hospital and interviewed them using two questionnaires: the faecal incontinence quality of life (FIQL) scale and the Wexner faecal incontinence score (WS). The patients were allocated in 3 groups based on the primary diagnosis leading to operation, i. e. slow-transit constipation or megacolon (STC), colonic neoplasm (CA) and complicated pan-colonic diverticular disease (DD). Median bowel frequencies for STC and DD groups were 2.5/day; for CA, it was 3.5/day (p=0.042). There was no significant difference in the FIQL score and WS between the groups. Eleven patients had some degree of faecal incontinence based on WS. Many patients (20.4%) with perfect continence had fear of faecal leakage affecting their quality of life. In conclusion, patients with frequent stools do not need to have incontinence to suffer from the fear of it. The primary pathology leading to TC made no difference to the faecal incontinence or bowel urgency problems.

Adult↗
PubMed2001

Regulation of herpes simplex virus type 1 replication in Vero cells by Psychotria serpens: relationship to gene expression, DNA replication, and protein synthesis.

Inhibitory effects of ethanolic extracts from seven Chinese herbs on herpes simplex virus type 1 (HSV-1) replication were investigated. From a bioassay-guided fractionation procedure, PS-A-6 was isolated from Psychotria serpens (P. serpens), which suppressed HSV-1 multiplication in Vero cells without apparent cytotoxicity. Time-of-addition experiments suggested that the inhibitory action of PS-A-6 on HSV-1 replication was not through blocking of virus adsorption. In an attempt to further localize the point in the HSV-1 replication cycle where arrest occurred, a set of key regulatory events leading to viral multiplication was examined, including viral gene expression, DNA replication, and structural protein synthesis. The results indicated that gB mRNA and protein expression in Vero cells were impeded by PS-A-6. Southern blot analysis showed that HSV-1 DNA replication in Vero cells was arrested by PS-A-6. In addition, PS-A-6 decreased thymidine kinase (tk) and ICP27 mRNA expression in the cells. The mechanisms of antiviral action of PS-A-6 seem to be mediated, at least in part, through inhibition of early transcripts of HSV-1, such as tk and ICP27 mRNAs, arresting HSV-1 DNA synthesis and gB gene expression in Vero cells. Plans are underway for the isolation of pure compounds from PS-A-6 and elucidation of their mechanism of action.

Animals↗
PubMed2001

Randomized trial assessing anal sphincter injuries after stapled haemorrhoidectomy.

BACKGROUND: Conventional stapled haemorrhoidectomy involves the use of a large circular anal dilator (DL technique), which may cause anal sphincter injuries. This study compared whether the procedure can be effectively performed without this dilator (ND technique), with better sphincter preservation. METHODS: Fifty-eight patients with symptomatic prolapsed irreducible haemorrhoids were randomized to DL (n = 29) and ND (n = 29) groups. Preoperative continence scoring, anorectal manometry and endoanal ultrasonography were performed. These were repeated at up to 14 weeks after operation, with additional pain scores, analgesic requirements and quality of life assessments. RESULTS: DL haemorrhoidectomy took significantly longer to perform (P = 0.02). However, there were fewer residual skin tags (P = 0.044) and less perianal pruritus (P = 0.007) at 2 weeks, although such symptoms subsided to an equivalent level in both groups afterwards. Internal anal sphincter fragmentation persisting to at least 14 weeks was found in four patients after DL, but not after ND haemorrhoidectomy (P = 0.038). However, these were asymptomatic and no differences were found in continence scores and anal pressures. The pain scores, satisfaction scores, quality of life assessments and time off work were similar. CONCLUSION: The large circular anal dilator used for stapled haemorrhoidectomy increased the risk of anal sphincter injuries, which may become problematic with ageing.

Adult↗
PubMed2001

Primary colorectal signet-ring cell carcinoma in Singapore.

BACKGROUND: Primary colorectal signet-ring cell carcinoma is a rare but distinctive tumour of the colon and rectum. The clinicopathological features are still controversial. The aim of this study is to review the clinicopathological features and management of this type of tumour in our hospital. METHODS: The clinicopathological features and survival data of all cases of primary colorectal signet-ring cell carcinoma were reviewed retrospectively. RESULTS: There were nine cases of primary colorectal signet-ring cell carcinoma in 3000 consecutive colorectal carcinoma patients seen from 1989 to 1999. There were seven male and two female patients with a mean age of 54.7 years. Three patients were younger than 40 years. The common presenting symptoms were rectal bleeding (33%) and small bowel obstruction (33%). Two (22%) patients required emergency surgery due to acute small bowel obstruction. The most common tumour location was the right colon (44%) followed by the rectum (33%). All nine patients presented at a very late stage of disease. A majority (77%) had Dukes' C disease while two (22%) had Dukes' D disease with distant dissemination. Peritoneal spread (33%) was the most frequent way of dissemination. There was no patient with liver metastases at the time of diagnosis and initial presentation. The mean survival time was 30 (range 5-108) months. The 5-year survival rate was 12%. CONCLUSIONS: Primary colorectal signet-ring cell carcinoma is frequently diagnosed late with a very poor prognosis. A high incidence of peritoneal seeding and low incidence of liver metastases appears to be a characteristic of signet-ring cell carcinoma of the colon and rectum.

Adult↗
PubMed2001

External beam radiation therapy for inoperable hepatocellular carcinoma with portal vein thrombosis.

Portal vein thrombosis (PVT) in patients with hepatocellular carcinoma (HCC) has a poor impact on prognosis. Many of these tumors may cause intrahepatic and extrahepatic metastases. From January 1991 to December 1996, 41 unresectable HCC patients with PVT underwent transcatheter arterial chemoembolization (TACE) and external beam radiation therapy (EBRT) to the portion of PVT. The irradiated field, with a mean equivalent field size of 6.6 x 7.1 cm2, was localized and simulated by abdominal sonography, angiography and computed tomography. Radiation dose ranged from 36 to 66 Gy (mean dose: 51.4 Gy), in a daily fraction of 1.8 to 2 Gy. The response of EBRT was evaluated by abdominal sonography within 3 months of completion of EBRT. The response rates of the PVT after treatment were 39% for complete response (CR), 41% for partial response (PR), and 19% for no response (NR), respectively. The median overall survival time from start of radiotherapy was 10 months for all patients, 17 months for CR patients, 8 months for PR patients and 4 months for NR patients. By multivariate analysis, response of PVT resulted in a significant improvement in survival. (P = 0.001) There was no occurrence of severe complication of radiation-induced liver disease. The results obtained with combined treatment modality of EBRT and TACE in the treatment of HCC patients with PVT are encouraging.

Adult↗
PubMed2000

Postoperative intra-abdominal free gas after open colorectal resection.

PURPOSE: An erect chest radiograph for subdiaphragmatic free gas can be a useful adjunct in detecting a defect in gastrointestinal continuity. The usefulness of this test after laparotomy has not been defined, because the period of persistence of free gas is unknown. We set out to determine the length of time for natural absorption of postlaparotomy pneumoperitoneum in a prospective cohort study. METHOD: Plain erect chest radiographs were performed on the second and fourth postoperative day and daily thereafter until the disappearance of subdiaphragmatic free gas after laparotomy. RESULTS: Seventy-five consecutive patients were studied after informed consent. The mean age was 62.1 (standard error of the mean, 1.7) years. On the fifth postoperative day, sixth postoperative day, and seventh postoperative day, 71.6, 80, and 89 percent of patients, respectively, had no visible subdiaphragmatic gas. Five patients had gas persisting beyond the tenth postoperative day. Two of these patients did not have an anastomosis. The use of drainage tubes did not affect significantly the mean time to disappearance of subdiaphragmatic free gas (4.5 vs. 4.9 days; P = 0.45: t-test). The duration of surgery, body mass index, and time to resume bowel function had no significant effect on gas disappearance. Two patients had a clinical leak on the fifth postoperative day. This was manifested as an increase in the collection of subdiaphragmatic gas during the course of a day. CONCLUSION: By the sixth postoperative day 80 percent of patients had no subdiaphragmatic free gas on an erect chest radiograph regardless of the presence of a drainage tube. The erect chest radiograph may therefore be a simple and readily available adjunct in the evaluation of postoperative abdominal pain, especially after the sixth postoperative day when a similar prior examination is done routinely on the fourth postoperative day for comparison.

Anastomosis, Surgical↗
PubMed2000

Stapled hemorrhoidectomy--cost and effectiveness. Randomized, controlled trial including incontinence scoring, anorectal manometry, and endoanal ultrasound assessments at up to three months.

PURPOSE: Stapled hemorrhoidectomy is performed without leaving painful perianal wounds. The aim of this study was to assess any benefits, compared with a conventional open diathermy technique. METHODS: A total of 119 consecutive patients with prolapsed irreducible hemorrhoids were randomly assigned (conventional open diathermy technique = 62; stapled hemorrhoidectomy = 57). Preoperative fecal incontinence scoring, anorectal manometry, and endoanal ultrasound were performed. Postoperatively, these were repeated at up to three months with pain scores, analgesic requirements, quality of life assessment, and total related medical costs. RESULTS: Conventional open diathermy technique was quicker to perform (mean, 11.4 (standard error of the mean, 0.9) vs. 17.6 (3.1) minutes). Hospitalization was similar, but conventional open diathermy technique patients felt more pain during defecation (5.1 (0.4) vs. 2.6 (0.4); P < 0.005) at two weeks, and analgesic requirements were more for up to six weeks (P < 0.05). Up to the latter, 85.5 percent conventional open diathermy technique wounds remained unhealed, with more bleeding (33 (53.2 percent) vs. 19 (33.3 percent); P < 0.05) and pruritus (27 (43.5 percent) vs. 9 (15.8 percent); P < 0.05). Total complication rates were similar (conventional open diathermy technique 16 (25.8 percent) vs. stapled hemorrhoidectomy 10 (17.5 percent)), including mild strictures and bleeding in both groups. Minor incontinence occurred postoperatively in two conventional open diathermy technique and two stapled hemorrhoidectomy patients at six weeks. Endoanal ultrasound internal anal sphincter defects were found in the incontinent conventional open diathermy technique patients, but were asymptomatic in another one conventional open diathermy technique and one stapled hemorrhoidectomy. Only one patient (conventional open diathermy technique with internal sphincter defect) remained incontinent at three months. Changes between preoperative and postoperative anorectal manometry were similar in the two groups. Patients' satisfaction scores and quality of life assessments were also similar. Conventional open diathermy technique patients resumed work later (mean 22.9 (1.8) vs. 17.1 (1.9) days; P < 0.05), but the total costs incurred were less ($921.17 (16.85) vs. $1,283.09 (31.59); P < 0.005). CONCLUSIONS: Stapled hemorrhoidectomy is a safe and effective option in treating irreducible prolapsed piles. It is more expensive but less painful, with less time needed off work. Nonetheless, long-term results are still awaited.

Adult↗
PubMed2000

Anal sphincter injuries from stapling instruments introduced transanally: randomized, controlled study with endoanal ultrasound and anorectal manometry.

PURPOSE: Injury sustained from the transanally introduced stapling technique was assessed by comparison with biofragmentable anastomotic ring anastomosis, which excluded anal manipulation. METHODS: A randomized, controlled trial was conducted on consecutive patients undergoing sigmoid colectomy (where pelvic nerve injury was avoided). A bowel function questionnaire was administered six months after surgery. Anorectal manometry and endoanal ultrasonography were performed preoperatively and at six months postoperatively. The observers were blinded to the randomization. RESULTS: There were 18 patients in the transanally introduced stapling technique group and 17 patients in the biofragmentable anastomotic ring group, with no differences in age, gender, Dukes staging, and follow-up. Three of the transanally introduced stapling technique patients had occasional liquid soiling, which was absent in biofragmentable anastomotic ring patients. Mean change in resting anal pressures was also significantly impaired when compared with patients with biofragmentable anastomotic ring (P = 0.007). Endosonographic internal sphincter fragmentation was found in five transanally introduced stapling technique patients but none after biofragmentable anastomotic ring anastomosis (P = 0.046). Internal sphincter fragmentation was associated with the impaired resting pressures (P = 0.007). External sphincter deficiencies were found after transanally introduced stapling technique in two patients (biofragmentable anastomotic ring = 0), and these were associated with the soiling (P = 0.005). CONCLUSIONS: The transanally introduced stapling technique may result in anal sphincter defects and impaired anal pressures when assessed at six months of follow-up.

Adenocarcinoma↗
PubMed2000

Micronized purified flavonidic fraction compared favorably with rubber band ligation and fiber alone in the management of bleeding hemorrhoids: randomized controlled trial.

PURPOSE: The aim of this study was to assess the role of micronized purified flavonidic fraction in the management of bleeding nonprolapsed hemorrhoids. METHODS: Patients were randomly assigned to receive ispaghula husk alone, rubber band ligation plus ispaghula husk, or micronized purified flavonidic fraction plus ispaghula husk. Other colorectal diseases were excluded by colonoscopy. Blinded observers noted the time for bleeding to stop completely, recurrences, and treatment complications. RESULTS: A total of 162 patients were randomly assigned with no significant differences in the age and gender distributions among the groups. Hemorrhoidal bleeding was relieved most expediently in the micronized purified flavonidic fraction plus ispaghula husk group (ispaghula husk alone n = 66, mean (standard error of the mean) 10.6 (2.3) days; rubber band ligation plus ispaghula husk n = 57, 5.6 (1.1) days; micronized purified flavonidic fraction plus ispaghula husk n = 39, 3.9 (1.2) days; P = 0.03). However, there were no significant differences in the recurrences at six months of follow-up (ispaghula husk alone n = 8 (12 percent); rubber band ligation plus ispaghula husk n = 12 (21 percent); micronized purified flavonidic fraction plus ispaghula husk n = 2 (5.1 percent); P = 0.075). No complications or side-effects were noted. CONCLUSIONS: micronized purified flavonidic fraction used with fiber supplements rapidly and safely relieved bleeding from nonprolapsed hemorrhoids.

Adult↗
PubMed2000

Ambulatory manometry in patients with colonic J-pouch and straight coloanal anastomoses: randomized, controlled trial.

PURPOSE: Bowel function after ultralow anterior resection may be improved by a colonic J-pouch. The aim of this study was to compare the bowel function and ambulatory manometry in patients randomly assigned to straight coloanal anastomosis or colonic J-pouch. METHODS: Forty-seven consecutive patients underwent ultralow anterior resection for adenocarcinoma. The colonic J-pouch was constructed with 6-cm limbs. A bowel function questionnaire was administered at one year after surgery. Ambulatory manometry was performed before and at one year after surgery. RESULTS: Values are expressed below as mean and (standard error of the mean). Patients with colonic J-pouch were found to have less frequent stools (4.6 (0.3) vs. 7.1 (0.9) stools/day; P < 0.05) and stool clustering (35 vs. 63.2 percent; P < 0.05) and were less unlikely to soil when passing flatus (85 vs. 35.3 percent; P < 0.05). The ambulatory anorectal pressure gradient was better preserved in the colonic J-pouch group (30.3 (3.7) vs. 18 (2.6) mmHg; P < 0.05). Stool frequency was predicted by the mean rectal pressures (t = 3.368; P = 0.003). However, higher mean rectal pressures were tolerated by the colonic J-pouch for each daily bowel movement (6.7 (0.6) vs. 4.4 (0.5) mmHg/stool; P = 0.008). Anal sampling episodes and slow wave activity were impaired postoperatively in both groups. The minimal anal pressures were lower in patients unable pass flatus without soiling (12.4 (5.3) vs. 26 (2.3) mmHg; P = 0.004). Large contraction waves were not seen, and this may be related to the absence of severe defecation problems with 6-cm colonic J-pouches. CONCLUSIONS: A colonic J-pouch resulted in better bowel function and more favorable ambulatory manometric findings at one year of follow-up.

Adenocarcinoma↗
PubMed2000

Pilonidal disease in Singapore: clinical features and management.

BACKGROUND: Pilonidal disease has not been well documented in Asian people. The aims of the present study were to investigate any variations in the clinical features and effectiveness of various surgical treatments in such a population. METHODS: A prospectively collected computerized database of 61 consecutive patients admitted to a specialist colorectal unit over a 9-year period was studied. The five methods of surgical treatment used during this period (incision and drainage; laying open; marsupialization; primary closure; and the flap procedure) were compared. RESULTS: There were 38 men and 23 women with a mean age of 27+/-1.02 years. Pilonidal disease was significantly more common among the Indian people (52.5% of patients) than the other ethnic races in the Singaporean community (P < 0.001). Chronic discharging sinuses were the most common presentation (93.4%). There were no differences between the various surgical techniques employed with regard to the time required for wound healing (mean: 48+/-21 days) and recurrence rates (4/61, 6.6%). Wound dehiscence after primary wound closure (10%) and flap procedures (42%) meant that the overall healing rate was not faster than when the wound was just laid open. Furthermore, flap procedures required a longer hospitalization than other procedures (P = 0.005). CONCLUSION: Pilonidal disease was more common among Indian people, the more hirsute among the Singaporean population. Primary closure and flap procedure did not improve overall wound healing because of dehiscence.

Adult↗
PubMed1999

Anal pressures impaired by stapler insertion during colorectal anastomosis: a randomized, controlled trial.

PURPOSE: The significance of anal sphincter injury from transanal inserted staplers was studied. A randomized, controlled comparison was made of anorectal manometry and clinical function after sigmoid colectomy (avoiding nerve injury from rectal mobilization), anastomosed by either transanal inserted stapler or biofragmentable anastomotic ring (avoiding anal manipulation). METHOD: Fifty-eight consecutive patients with sigmoid adenocarcinoma were randomly assigned to transanal inserted stapler or biofragmentable anastomotic ring groups. Anorectal manometry and clinical bowel function assessment were performed by an independent blinded observer before surgery and six weeks and six months after surgery. RESULTS: At six weeks after surgery, there was significant impairment of mean anal resting pressures (mean impairment, 23 percent; P < 0.001) and physiologic anal length (mean impairment, 31 percent; P < 0.01) in the transanal inserted stapler group (27 completed the trial), but not in the biofragmentable anastomotic ring group (18 completed the trial). Pressures remained impaired at six months. When changes in the anal pressures were compared between groups, the mean anal resting pressure (P < 0.001) and maximum squeeze pressure (P < 0.01) at six weeks and mean anal resting pressure at six months (P < 0.01) were significantly more impaired in the transanal inserted stapler group. Postoperative bowel function was not different between the two groups. Postoperative complications were similar. In the transanal inserted stapler group one patient died of anastomotic leak sepsis and one had wound infection; in the biofragmentable anastomotic ring group one patient died of myocardial infarct and one had wound infection. CONCLUSION: Direct injuries to the internal anal sphincter occurred after transanal inserted stapler but not biofragmentable anastomotic ring anastomoses. Clinical function was not correspondingly affected, probably because of the adequate residual rectal reservoir after sigmoid colectomy.

Adenocarcinoma↗
PubMed1999

Randomized, controlled trial of low molecular weight heparin vs. no deep vein thrombosis prophylaxis for major colon and rectal surgery in Asian patients.

PURPOSE: Routine deep venous thrombosis prophylaxis is controversial in Asian patients, because deep venous thrombosis incidence was considered negligible. Because of recent reports of significantly higher incidences, a randomized, controlled trial was conducted to assess the effectiveness and complications of enoxaparin prophylaxis (low molecular weight heparins) in major colorectal surgery. METHODS: Three hundred twenty consecutive patients were randomly assigned to control or low molecular weight heparins groups. Patients in the low molecular weight heparins group were given perioperative enoxaparin starting 12 hours before surgery. The surgeon (blinded) assessed for difficulties related to possible enoxaparin administration. Independent blinded observers performed daily clinical assessments and Doppler studies (at the 3rd and 5th postoperative day). Deep venous thrombosis was confirmed by duplex ultrasound, and pulmonary embolism was confirmed by lung scans or postmortem examinations. RESULTS: Deep venous thrombosis developed in 5 of 169 (3 percent) controls and 0 of 134 low molecular weight heparins patients (P = 0.045). Three of the deep venous thrombosis patients had pulmonary embolism, which was fatal in one patient. The surgeons were unable to perceive any increased surgical difficulties in the low molecular weight heparins group. The bleeding-related complications were significantly higher in the low molecular weight heparins patients (controls, n = 3 (1.8 percent); low molecular weight heparins, n = 9 (6.7 percent)). However, apart from one subdural hematoma and two abdominal hemorrhages needing re-exploration, which also occurred in one of the controls, these complications were minor bruises at the wounds, drains, or injection sites. CONCLUSION: Deep venous thrombosis prophylaxis is needed in Asian patients undergoing major colorectal surgery.

Aged↗
PubMed1999

Difference in the effects of radioprotection between aerial and root parts of Lycium chinense.

Radiation protection from bone marrow death by consecutive injections of crude extracts from different parts of Lycium chinense (LC), root (LCR) and aerial part (LCA), before whole body X-irradiation was confirmed by tests with ICR strain mice. Both extracts were effective after intraperitoneal injection of a high dose, once a day, for seven consecutive days before irradiation. Based on the studies of endogenous hematopoietic spleen colony formation (CFUs), and the postirradiation behavior of hematograms and hematocrits, it was demonstrated that the LCR protects mice more effective when given in a dose of 500 mg/kg. Enhanced CFUs was found in the irradiation range of 4-8 Gy by various treatments. Recovery of leukocyte, erythrocyte and thrombocyte counts was significantly stimulated by the extract of LCR with 500 mg/kg administration. Stimulated recovery by the extract from the LCR was also observed in hematocrit. On the contrary, the extracts of both LCA and LCR did not markedly affect recovery of leukocyte, erythrocyte, thrombocyte counts and hematocrits by 250 mg/kg administration. It could be deduced that the uncertainly radioprotective action is induced by a possible process of enhanced regeneration of the hematopoietic stem cells due to either enhanced postirradiation repair or an increased proliferation of the hematopoietic stem cells under the suitable extract administration.

Animals↗