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Biomedical subjects

T W Chin

Publications and source records attributed to T W Chin.

At least 19 recordsLinked to original sources
PubMed1998

Intraoperative non-puncture laparoscopic examination of contralateral internal inguinal rings is feasible in children with unilateral hydrocele.

BACKGROUND: Intraoperative non-puncture laparoscopic examination using the hernia sac as the scope entrance has been successfully conducted in children with unilateral inguinal hernia. This technique selects patients for contralateral inguinal exploration. In spite of the thin and narrow processus vaginalis, children with unilateral hydrocele encounter the same problem of subsequent contralateral inguinal hernia or hydrocele. In this study, we discuss the feasibility of this technique in children with unilateral hydrocele. METHODS: From July 1993 to September 1995, 91 children with unilateral hydrocele were examined during surgery at our institution. The results, including success rate, complications, patent rate of contralateral internal ring and contralateral subsequent hernia or hydrocele, at at least one year follow-up, were compared with those of 329 children with unilateral hernia undergoing the same examination during this period. RESULTS: A patent contralateral processus vaginalis was recognized in 31 children and all were confirmed by surgical exploration. The examination failed in three patients, of whom two had a tear in the processus vaginalis and one had retroperitoneal air dissection as a result of false insertion of the laparoscopic sheath. One patient had a postoperative wound infection. No patient with contralateral obliterated processus vaginalis developed inguinal hernia or hydrocele during follow-up of at least one year. The results were similar to those of the 329 children with hernia who underwent the same procedure in the same period. CONCLUSIONS: Intraoperative non-puncture laparoscopic examination is feasible in children with unilateral hydrocele.

Child↗
PubMed1997

Radiological and survival comparison of four methods of fixation of a proximal femoral stem.

We compared the radiological appearances and survival of four methods of fixation of a femoral stem in 538 hips after follow-up for five or ten years. The fixation groups were: 1) press-fit shot-blasted smooth Ti-A1-V stem; 2) press-fit shot-blasted proximally ridged stem; 3) proximal hydroxyapatite (HA) coating; and 4) cementing. Survival analysis at five to ten years showed better results in the HA-coated (100% at five to six years) and cemented stems (100% at 5 to 6 years) than in the two press-fit groups. There was a higher mean rate of migration in the smooth and ridged Ti-A1-V shot-blasted press-fit groups (0.8 mm/year and 0.6 mm/year, respectively) when compared with the HA-coated and cemented prostheses (both 0.3 mm/year). More radiolucent lines and osteolytic lesions were seen in the press-fit groups than in either the HA-coated or cemented implants, with a trend for a lower incidence of both in the HA compared with the cemented group. Proximal osteopenia increased in the press-fit and cemented prostheses with time, but did not do so in the HA group. There was a higher incidence of resorption of the femoral neck with time in the cemented group than in the other three. We conclude that the HA and the cemented interfaces both provide secure fixation with a trend in favour of HA. The cemented prosthesis meets the suggested National Institutes of Health definition of 'efficacious' at ten years.

Adult↗
PubMed1997

Successful surgical treatment of bilateral congenital chylothorax: a case report.

A male infant was diagnosed at 19 days old to have a right chylothorax. Conservative management, including median-chain triglyceride (MCT) diet, total parenteral nutrition (TPN) and chyle drainage, were unsuccessful. The boy received a right thoracotomy with ligation of the thoracic duct and sutures of leaking lymphatic ducts at the age of 65 days. The result of the operation was satisfactory but left chylothorax developed six days later. Left thoracotomy was performed eight days later to suture the leaking lymphatic chains and finally the patient recovered well. Followed for one year, the patient's physical development was satisfactory. Prompt surgical intervention for congenital chylothorax is strongly recommended, if medical treatment fails.

Chylothorax↗
PubMed1997

Malignant epithelial neoplasm consistent with primitive cystic hepatic neoplasm with mesothelial differentiation: a case report.

Mesothelioma are primary tumors of the celiomic cavity and are seen more often in adults than in children: only an estimated 2-5% of all cases present within the first two decades of life. To best knowledge of the reviewing world literature reported to date, no more than 80 proved cases of this tumor have occurred in children. One-third of mesothelioma originate in the peritoneum and two-thirds arise in the pleural cavity. Mesothelioma of the liver are extremely rare; a review of the English literature shows only three adult cases that have been reported as fibrous mesothelioma of the liver; experience with these cases suggests a high potential for recurrence, but no progression to malignancy. Cystic mesothelioma occur mainly in adults and are considered to be benign and curable. We describe a case of malignant epithelial neoplasm consistent with primitive cystic hepatic neoplasm with mesothelial differentiation arising in a 3-year-old boy, a condition which has never before been reported in childhood. Malignant primitive cystic mesothelioma is possible that some cases of intraabdominal mesenchymoma or hamartoma with malignant differentiation may have been misdiagnosed in the past; future cases should be fully evaluated, to establish the true incidence of mesothelioma disease in children.

Child, Preschool↗
PubMed1996

Arthroscopic treatment of osteochondral lesion of the talus.

A retrospective study of the arthroscopic treatment of osteochondral lesions of the talus in 25 patients was conducted. The follow-up period ranged from 1 to 4 years with an average of 2 years. Of the 25 patients, 20 could recall a history of injury. The diagnosis could be made by standard anteroposterior and lateral X-rays in 22 out of 25 patients. The standard anteromedial and anterolateral portals were usually sufficient. Patients with stage I and II lesions did well uniformly. In the 16 patients with stage III and IV lesions, good results were obtained in 12 and fair in 4. Morbidity was minimal.

Ankle Injuries↗
PubMed1995

Pharmacokinetics of trimethoprim-sulfamethoxazole in critically ill and non-critically ill AIDS patients.

Current dosage regimens of trimethoprim-sulfamethoxazole used to treat Pneumocystis carinii pneumonia in AIDS patients have been based on data from healthy subjects or patients without AIDS. The clearance and absorption characteristics of the drugs may potentially be different between patients with and without AIDS. This study was conducted to assess the pharmacokinetics of trimethoprim-sulfamethoxazole in critically ill and non-critically ill AIDS patients treated for P. carinii pneumonia. Patients received trimethoprim at 15 mg/kg of body weight and sulfamethoxazole at 75 mg/kg of body weight daily intravenously in three to four divided doses and were switched to the oral route when the regimen was tolerated. Serum samples for determination of drug concentrations were obtained over 12 h after intravenous and oral dosing. The pharmacokinetics of trimethoprim and sulfamethoxazole were compared in eight critically ill versus nine non-critically ill male patients and were as follows, respectively: clearance, 1.88 +/- 0.44 versus 1.73 +/- 0.64 ml/min/kg for trimethoprim and 0.40 +/- 0.12 versus 0.34 +/- 0.11 ml/min/kg for sulfamethoxazole; volume of distribution, 1.6 +/- 0.5 versus 1.5 +/- 0.5 liters/kg for trimethoprim and 0.5 +/- 0.3 versus 0.4 +/- 0.1 liters/kg for sulfamethoxazole; and half-life, 10.9 +/- 7.4 versus 11.3 +/- 4.0 h for trimethoprim, and 15.5 +/- 9.5 versus 14.3 +/- 4.7 h for sulfamethoxazole. No significant differences (P > 0.05) were observed between patient groups, although there was wide intersubject variability. Absorption appeared to be similar between the critically ill and non-critically patients: bioavailability was 97.5% +/- 22.4% versus 101.8% +/- 22.7% for trimethoprim and 86.2% +/- 17.9% versus 99.1% +/- 20.5% for sulfamethoxazole, respectively. Because of the similar pharmacokinetics of trimethoprim-sulfamethoxazole in critically ill and non-critically ill AIDS patients, the two groups of patients may receive similar dosages. Dosage adjustment does not appear to be required when switching from the intravenous to the oral route.

AIDS-Related Opportunistic Infections↗
PubMed1995

Effects of an acidic beverage (Coca-Cola) on absorption of ketoconazole.

Absorption of ketoconazole is impaired in patients with achlorhydria. The purpose of this study was to determine the effectiveness of a palatable acidic beverage (Coca-Cola Classic, pH 2.5) in improving the absorption of ketoconazole in the presence of drug-induced achlorhydria. A prospective, randomized, three-way crossover design with a 1-week wash-out period between each treatment was employed. Nine healthy nonsmoking, nonobese volunteers between 22 and 41 years old were studied. Each subject was randomized to receive three treatments: (A) ketoconazole 200-mg tablet with water (control), (B) omeprazole (60 mg) followed by ketoconazole (200 mg) taken with water, and (C) omeprazole (60 mg) followed by ketoconazole (200 mg) taken with 240 ml of Coca-Cola Classic. The pH values of gastric aspirates were checked after omeprazole was administered to confirm attainment of a pH of > 6. Multiple serum samples were obtained for measurements of ketoconazole concentrations by high-pressure liquid chromatography. The mean area under the ketoconazole concentration-time curve from zero to infinity for the control treatment (17.9 +/- 13.1 mg.h/liter) was significantly greater than that for treatment B (3.5 +/- 5.1 mg.h/liter; 16.6% +/- 15.0% of control). The mean peak concentration was highest for the control treatment (4.1 +/- 1.9 micrograms/ml), for which the mean peak concentration showed a significant increase over that for treatment B. The absorption of ketoconazole was reduced in the presence of omeprazole-induced achlorhydria. However, drug absorption was significantly increased, to approximately 65% of the mean for the control treatment, when the drug was taken with an acidic beverage, such as Coca-Cola.

Achlorhydria↗
PubMed1995

Surgical treatment of symptomatic accessory navicular.

The accessory navicular is a known cause of foot pain. When symptomatic and conservative measures have failed, surgical intervention may be required. Simple excision of the ossicle or the Kidner procedure with transplantation of tibialis posterior tendon to the undersurface of the navicular bone may be done. Eighteen patients with symptomatic accessory navicular were reviewed at the Singapore General Hospital, Department of Orthopaedic Surgery 'O' Unit. All 18 patients had foot pain and restriction of activities. Thirteen noticed a prominence on the medial side of the affected foot and 7 had difficulty with shoe fitting. Nine underwent simple excision of the ossicle while the other 9 had the Kidner procedure done. The average follow-up period was 3.1 years. Both the simple excision and the Kidner procedure were equally successful in relieving symptoms in 15 out of the 18 cases. The Kidner procedure did not confer any particular advantage over simple excision.

Adolescent↗
PubMed1995

Tarsometatarsal (Lisfranc's) injuries--results of open reduction and internal fixation.

Injuries of the tarsometatarsal (Lisfranc's) joint are uncommon and are potentially associated with chronic disability. The aim of our study was to review retrospectively the results of open reduction with Kirschner wire internal fixation of tarsometatarsal injuries. In this study, 12 patients with Lisfranc's injuries treated between January 1986 and March 1993 were reviewed at an average of 36 months after the injuries. Majority of the patients suffered from type B injuries (Hardcastle's classification, 1982). There were 9 closed and 3 open injuries. All were high energy injuries sustained in motor vehicle accidents, fall from a height or crush force. All were treated with open reduction and internal fixation with Kirschner wires. Anatomical reduction was achieved and maintained. There was no postoperative redisplacement. During follow-up, most patients developed radiological evidence of post-traumatic osteoarthritic changes. However, majority of the patients were pain-free or had very little foot pain, and were able to return to their previous occupation. Our study showed that open reduction with Kirschner wire internal fixation offered satisfactory anatomical and functional results.

Accidental Falls↗
PubMed1994

Histiocytosis X involving thyroid gland: a case report.

Diffuse histiocytosis X involving thyroid gland is rare. A 10-year-old boy with progressively enlarged neck mass, skin rash over scalp and face, splinter hemorrhage, otitis externa, episodes of pneumothorax and abnormal liver function was hospitalized. Thyroid scan showed a nonfunctioning mass in the right lobe of the thyroid and needle aspiration biopsy suspected histiocytosis X. Right thyroid lobectomy was performed and revealed histiocytosis X in light and electron microscopic examinations.

Biopsy, Needle↗
PubMed1992

Recombinant human mullerian inhibiting substance inhibits human ocular melanoma cell lines in vitro and in vivo.

Since Mullerian Inhibiting Substance (MIS) causes regression of the Mullerian duct, the anlagen of the uterus, vagina, and fallopian tube, we expected and have previously observed that purified recombinant human MIS causes regression of gynecological tumors. However, recent experiments indicating that neural crest derivatives might be responsive to MIS prompted study of a group of human ocular melanoma cell lines in 4 in vitro inhibition assays, and a subrenal capsule assay in vivo. Ocular melanoma cell lines that grew well in a respective assay were studied with MIS to determine whether this biological modifier could inhibit growth. Three human ocular melanomas, OM431 (P less than 0.01), OM467 (P less than 0.02), and OM482 (P less than 0.03), were growth-inhibited by highly purified human recombinant MIS in soft agarose. A dose-dependent tumor inhibition was noted when OM431 cells were incubated with MIS in a liquid colony inhibition assay (P less than 0.05). In addition, OM467 was inhibited (P less than 0.05) by MIS in a multicellular tumor spheroid assay. Cell cycle analysis indicated that OM431 cells were inhibited in monolayer by MIS while in G1. At 100-fold lower serum concentrations than required in the media of in vitro assays, MIS delivered via i.p. osmotic pumps inhibited (P less than 0.05) in vivo the growth of OM431 implanted beneath the renal capsule of nude and CD-1 irradiated mice when compared to mice given implants of pumps containing no MIS. The responsiveness of ocular melanoma to MIS broadens the spectrum of tumors that might be treated with MIS and suggests further investigation of other neural crest tumors.

Animals↗
PubMed1992

Detrimental effect of hypotonic cromolyn sodium.

In a randomized, double-blind, placebo-controlled, crossover study, inhalation of the commercially available nebulized form of cromolyn sodium resulted in a significant decrease in forced midexpiratory flow rate between the 25th and 75th percentile points, equivalent to that observed for distilled water, in children with chronic asthma. We conclude that inhalation of the current hypotonic concentration of cromolyn sodium may be detrimental.

Administration, Inhalation↗
PubMed1992

Familial pulmonary nodular lymphoid hyperplasia.

We describe three persons in one family with diffuse lung infiltrates, digital clubbing, and chronic hypoxia. Elevated immunoglobulin levels and antinuclear antibodies were found in all patients; pathologic findings included hyperplastic lymphoid follicles infiltrating the epithelium of the small airways. These cases may represent a familial systemic autoimmune disorder seen primarily with pulmonary compromise.

Adult↗
PubMed1992

Case report: treatment of blastomycosis with fluconazole.

The authors present two cases of systemic blastomycosis successfully treated with fluconazole. In one case, the disease involved the respiratory tract, and the central nervous system was presumed to be involved. The second case consisted only of pulmonary blastomycosis. Both patients were treated with oral fluconazole 200 mg twice per day for 9 and 6 months, respectively. Treatment with this new triazole antifungal agent resulted in the complete resolution of the disease in both patients. They have remained asymptomatic for more than 6 months after the completion of therapy.

Adult↗
PubMed1992

Catheter-related complications of continuous ambulatory peritoneal dialysis.

OBJECTIVE: To assess the effectiveness of continuous ambulatory peritoneal dialysis (CAPD) with particular reference to morbidity. DESIGN: Open study. SETTING: Two city general hospitals. SUBJECTS: 104 Adults and 11 children with end stage renal failure. MAIN OUTCOME MEASURE: Morbidity. RESULTS: There were 29 complications (25%), the most common being obstruction of the tube (n = 8, 7%), and migration of the tube (n = 7, 6%). Others were peritonitis (n = 5), haemorrhage (n = 4), infection at the exit site (n = 3), and leakage of fluid (n = 2). All were readily treatable. CONCLUSIONS: Fixing the catheter in two places may prevent its migration. The complication rate of CAPD is acceptable, and in children with end stage renal failure it is a suitable alternative to haemodialysis while they are waiting for renal transplantation.

Adult↗
PubMed1991

Human müllerian inhibiting substance inhibits tumor growth in vitro and in vivo.

Müllerian inhibiting substance (MIS) causes regression of the müllerian duct in the male fetus. Bovine MIS has been reported to inhibit the growth of some gynecological tumors. Recombinant human MIS (rhMIS) produced in transfected Chinese hamster ovary cells has been highly purified by immunoaffinity chromatography. The introduction of a salt wash prior to elution of MIS from the affinity column removes a growth-stimulating factor(s) derived from Chinese hamster ovary cells. This immunopurified rhMIS caused significant inhibition (34-59% survival) of A431 (a vulvar epidermoid carcinoma), HT-3 (a cervical carcinoma), HEC-1-A (an endometrial adenocarcinoma), NIH:OVCAR-3 (an ovarian adenocarcinoma), and OM431 (an ocular melanoma) human cell lines in colony inhibition assays. Two cell lines, Hep 3B (a hepatocellular carcinoma) and RT4 (a bladder transitional cell papilloma), were unresponsive to immunopurified rhMIS. Using an in vivo subrenal capsule assay in irradiated CD-1 mice, the growth of A431 and OM431 cells was inhibited by immunopurified rhMIS. We conclude that rhMIS inhibits the growth of certain tumor cell lines in vitro and in vivo.

Animals↗
PubMed1991

Effects of herpes simplex virus on induced cell-mediated cytotoxicity in neonates and adults.

Deficient cellular cytotoxic mechanisms are present in neonates, contributing to their increased susceptibility to certain viruses, notably herpes simplex virus (HSV). Significant lymphokine-activated killer (LAK) cell activity has been described in cord blood, suggesting a possible role for LAK and/or interleukin-2 (IL-2) therapy in newborns with serious viral infections. The effect of HSV (type 1) on the activation of cord versus adult LAK cells was investigated by adding virus (multiplicity of infection, MOI = 10) to cells that had been previously incubated for 4-6 days with IL-2 (50-100 U/ml). The cells were then tested 24 h after virus exposure for cytotoxic activity against 51Cr-labelled K562 and Raji target cells. HSV inhibited LAK cytotoxicity of adult cells against K562 by 44% (72 +/- 2.4%, SEM; specific lysis to 40 +/- 6.2%, n = 15) and by 62% against Raji targets (50 +/- 5.6 to 19 +/- 4.4%). A similar degree of inhibition was observed for cord cells against K562 (76 +/- 2.0 to 46 +/- 5.3%) and Raji (60 +/- 4.6 to 24 +/- 6.2%). The degree of inhibition was correlated with the dose of virus in dose-response experiments. Inhibition was also noted with irradiated (10,000 rad) but not with heat-inactivated (56 degrees C for 60 min) virus. No inhibition was found when virus was added directly to the cytotoxic assay or when virus was added at the initiation or end of culture of cells with IL-2 (i.e. day 0 or day 5-7). In contrast, HSV stimulated cytotoxic activity against both the natural killer (NK)-sensitive (K562) and NK-resistant (Raji) targets in cells not incubated with IL-2. The cytotoxicity of adult cells incubated with infectious HSV (MOI = 10) for 5-7 days increased from 5.5 +/- 1.9% in the absence of virus to 25 +/- 6.0% against K562 in the presence of virus and from 3.5 +/- 1.0 (no virus) to 16 +/- 4.3% (with virus) against Raji targets (n = 8). The cytotoxicity of cord cells was also stimulated, but to a lesser degree. Irradiated virus also stimulated cytotoxic activity but to a lesser degree in cord cells. Virus-induced nonspecific cytotoxicity may represent an important component of the host's antiviral defense that is present at birth, but somewhat diminished compared to normal adults.

Antibodies, Monoclonal↗