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Biomedical subjects

K Koh

Publications and source records attributed to K Koh.

At least 37 records · Page 2Linked to original sources
PubMed1996

[Diagnosis and therapy for metastatic liver cancer].

Hepatic metastases occur frequently in patients with colorectal cancer. Patients with advanced cancer should be followed carefully after curative resection of the primary lesions for the early detection of the recurrence. If hepatic metastasis is suspected on the basis of rising CEA levels, more sophisticated imaging techniques, such as ultrasound, computed tomography, magnetic resonance imaging and hepatic angiography should be employed for the diagnosis. However, these tests are not cost-effective and not warranted on a routine follow-up basis. To be more cost-effective, a relatively simple and sensitive test or group of tests should be used. The authors have proposed that the basement membrane producibility of the primary lesion yields the most important information predicting a liver metastasis; the basement membrane producing cancer highly metastasizes to the liver. In contrast, more than 90% of non-producing cancer does not metastasize to the liver. The basement membrane producibility is easily examined by laminin staining. In the treatment of hepatic metastases, hepatic resection is the preferred approach when the metastases are located in a resectable segment or can be encompassed by as many as five wedge resections, but these scenarios are relatively uncommon. For unresectable disease, chemotherapy and intravenous and/or intra-arterial embolization are viable alternatives. Loco-regional treatment may offer a pharmacological advantage since a liver metastasis is almost exclusively fed by the hepatic artery. A pilot study we conducted on hepatic infusion chemotherapy combined with interleukin-2 (IL-2.MF) revealed very encouraging results (response rate: 76%), and further study in a prospective randomized trial confirmed this high response rate. Adjuvant IL-2.MF infusion therapy after curative resection of liver metastases is also effective for the prevention of recurrence in the residual liver. Based on the data, we conclude that multimodal treatments of hepatic resection and loco-regional infusion of immuno-chemotherapy (IL-2.MF) make it possible to control both resectable and unresectable liver metastases.

Animals↗
PubMed1996

[LGL lymphoma].

We reported in this article two patients with large granular lymphocytic lymphoma (abbreviated as LGL lymphoma). One was the patient with LGL leukemia/lymphoma (patient 1) and other was the patient with NK-LGL lymphoma (patient 2). Because the gene of TCR delta was rearranged in the patient 1, the clonality of the LGL leukemia/lymphoma was confirmed. However, it is not determined yet whether the lineage of tumor cells is T cells or NK cells. The cytochemical features of the lymphoma cells of the patient 2 were studied. It was found that NK cell-derived lymphoma cells of the patient were positively stained with these two monoclonal antibodies that are reactive with T cell; one is anti-CD45RO (UCHL-1) and other is anti-CD3. Judging from the result, malignant NK-LGL cells in some patients are cytoplasmic CD3+ and UCHl-1+. It is emphasized that May-Grünwald-Giemsa stain of biopsied specimen of the lymphoma is required for making the diagnosis of LGL lymphoma.

Adult↗
PubMed1995

TNF-alpha regulates IL-4-induced Fc epsilon RII/CD23 gene expression and soluble Fc epsilon RII release by human monocytes.

We examined the regulatory effects of TNF-alpha on IL-4-induced gene expression of the low-affinity receptor for IgE (Fc epsilon RII/CD23) in human monocytes and IL-4-induced soluble Fc epsilon RII (sFc epsilon RII) release from monocytes. IL-4-induced Fc epsilon RII expression on the surface of monocytes was reduced by TNF-alpha as early as 1 day after culture and the effect of TNF-alpha increased with prolonged culture. The present analysis was designed to examine whether or not TNF-alpha could suppress IL-4-induced Fc epsilon RII mRNA expression and enhanced IL-4-induced sFc epsilon RII release. The addition of TNF-alpha to monocyte cultures with IL-4 significantly reduced Fc epsilon RII expression on the surface of monocytes and significantly increased sFc epsilon RII release from monocytes. Over time, there was an inverse relationship between the disappearance of cell surface Fc epsilon RII and the appearance of sFc epsilon RII in culture supernatants. Fc epsilon RII mRNA expression in monocytes cultured with IL-4 was not affected by TNF-alpha when examined at 6 h after cultivation. When the cells were cultured with TNF-alpha for more than 24 h, however, TNF-alpha down-regulated IL-4-induced Fc epsilon RII mRNA levels. This correlated with the kinetics of down-regulation of IL-4-induced Fc epsilon RII expression on the surface of monocytes by TNF-alpha.(ABSTRACT TRUNCATED AT 250 WORDS)

Base Sequence↗
PubMed1995

Shorter stay urology: the way forward.

A large part of the total cost of the treatment of surgical patients in hospitals is from the duration of hospitalization. Urology is well suited for short-stay surgery, and a large proportion of our work is elective in nature. We audited our in-patients over a 6-month period and found that 77% of our patients stayed for 3 days or fewer. The advantages of having elective 5-day beds in maintaining our throughput without requiring an increase in the total number of beds is discussed.

Costs and Cost Analysis↗
PubMed1994

Complete remission of liver metastases from colorectal cancer by treatment with a hepatic artery infusion (HAI) of interleukin-2-based immunochemotherapy: reports of three cases.

In an attempt to improve the therapeutic efficacy against liver metastases, a hepatic arterial infusion (HAI) of interleukin-2 (IL-2)-based immunochemotherapy for anticipating the regional potentiation of hepatic lymphokine-activated killer (LAK)/tumor-infiltrating lymphocytes (TIL) was initiated. We present herein the cases of three patients with multiple liver metastases from colorectal cancer in whom complete remission was achieved by treatment with an HAI of IL-2 in combination with mitomycin C (MMC) and 5-fluorouracil (5-FU). These patients received an HAI of IL-2 at 8 x 10(5) JRU, 5-FU at 250 mg daily, and MMC at 4 mg once weekly for 3 weeks, being the induction regimen, after which they were discharged on maintenance therapy consisting of IL-2 at 2 x 10(6) JRU, 5-FU at 250 mg twice weekly, and MMC at 4 mg once weekly. It was evident from the liver CT scan taken after 2-3 months that the metastatic foci seen before therapy had clearly disappeared, while the serum carcinoembryonic antigen (CEA) had decreased to normal levels in all three patients. Pancytopenia was seen in one patient, but other laboratory studies of the hepatic and renal parameters were normal. The total lymphocyte count in the peripheral blood showed a mild decrease, while the lymphocyte phenotype study showed a notable increase in CD4+ cells and a decrease in CD8+ cells, with an elevation of a 4/8 ratio, in all cases during therapy. One patient relapsed with pelvic recurrence 14 months after the initiation of therapy, but the other two patients are still in remission 25 and 22 months after the initiation of therapy.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1994

Relationship of decreased caecal urease activity by dietary penicillin to nitrogen utilisation in chickens fed on a low protein diet plus urea.

1. The relationship of the decreased caecal urease activity by dietary penicillin to nitrogen utilisation was assessed in chickens fed a low protein diet plus urea. 2. Dietary penicillin at 20 and 100 mg/kg decreased anaerobic bacteria counts, urease activity and ammonia concentration in caecal contents (P < 0.05, except for ammonia in the case of the 100 mg/kg penicillin diet). 3. The 20 mg/kg penicillin diets significantly increased the excretion of urea and total nitrogen (P < 0.05) and decreased ammonia excretion, and significantly reduced nitrogen retention (P < 0.05). The 100 mg/kg penicillin diet also resulted in similar but not significant changes, which tended to be less than those by the 20 mg/kg penicillin diet. 4. Ammonia, urea, glutamine and uric acid concentrations in blood, liver and kidney were unchanged by dietary penicillin. 5. It is concluded that caecal ammonia production from urea was closely correlated with nitrogen utilisation in chickens fed a low protein diet plus urea.

Ammonia↗
PubMed1994

Inhibitory effect of penicillin on caecal urease activity in chickens fed on a low protein diet plus urea.

1. The effects of dietary penicillin on the urease activities of small intestine, large intestine, caecum and their contents, liver and kidney in chickens fed a diet containing 5 g/kg protein plus urea were examined. 2. About 0.88 of the total urease activity determined was observed in intestinal contents, of which 0.95 of the activity was accounted for by caecal contents, 0.05 by colo-rectal contents and none by small intestinal contents. Intestinal tissues (caecum included), liver and kidney accounted for 0.03, 0.06 and 0.02, respectively, of the total urease activity. 3. Dietary penicillin decreased urease activity to 0.17 in caecal contents and to 0.05 in colo-rectal contents of the corresponding control values (P < 0.01). The urease activity of caecal tissue was lowered by penicillin to half that of control activity (P < 0.05) but none of the activities of other tissues were affected. 4. It is concluded that, even when the urease activity is stimulated by dietary urea, 20 mg/kg dietary penicillin can strikingly lower it in the caecum, where most of the urease activity in the chicken body is to be found.

Animals↗
PubMed1994

Dementia in elderly patients: can the 3R mental stimulation programme improve mental status?

The aim of this study was to determine whether the 3R mental stimulation programme can improve the mental status score (MSS) of a group of patients with dementia attending a day care centre. Fifteen patients with dementia attending a day care centre were exposed to the 3R stimulation programme over eight weeks while 15 controls were not. All patients from both groups were subjected to pre- and post-exposure questionnaires modified from the Mental Status Questionnaire of Kahn et al. A mental status score (MSS) was thus calculated on both occasions. All patients in the exposed group showed an improved mental status score, with the mean 'pre-exposure' and 'post-exposure' scores of 4.4 and 7.3, respectively (p < 0.001; paired t test). In contrast, the mental status scores of 12 control patients had deteriorated and mean 'pre-exposure' and 'post-exposure' scores were 4.1 and 3.4, respectively (p < 0.05; paired t test). Using multiple covariance analysis, the adjusted 'post-exposure' mean mental status score was 7.1 for the exposed and 3.6 for the controlled group (p < 0.001). The 3R programme appears to be effective for short-term mental stimulation of demented elderly people.

Aged↗
PubMed1994

[Adaptation and effects of ileal reservoir on ileo-proctostomy following total colectomy in dogs].

We examined postoperative adaptation and effects of J-pouch reservoir on ileo-proctostomy following total colectomy in dogs. End to end (E-E; n = 5) or J-pouch (J-P; n = 5) anastomosis was performed after resection of total colon and the rectum 3 cm above the peritoneal reflexion. Gastrointestinal motility with strain gauge force transducers (SG) and transit time with barium meal under the fluoroscopy were recorded 6 months after total colectomy. Then, histological changes of seven specimens from totally resected ileum in J-P and E-E vs control (normal ileum; n = 5) were measured with hematoxylin-eosin and PYY immunohistochemical stains. Propagation rate of interdigestive migrating complex (IMC) from jejunum to ileum was significantly lower in J-P (64.8 +/- 13.2%) than in E-E (98.6 +/- 1.2%) (p < 0.001). Oro-neorectal transit time (ONTT) in E-E (138 +/- 10 min) was shorter (p < 0.05), but ONTT in J-P (189 +/- 26 min) was significantly longer (p < 0.01) than oro-caecal transit time (OCTT) in preoperative control (165 +/- 19 min; n = 10). There was no difference about length of villi among control, E-E and J-P, but length of crypts in J-P (0.59 +/- 0.08 mm) was longer than that in E-E (0.27 +/- 0.02 mm) and normal ileum (0.34 +/- 0.07 mm) (p < 0.01). PYY positive cells in J-P were more than in E-E and control at any site of ileum and total number of PYY positive cells in J-P (168 +/- 18) significantly increased than that in E-E (111 +/- 16) and control (103 +/- 14) (p < 0.05). Thus, increase of PYY positive cells in J-P inhibits gastrointestinal motility and transit. Delayed transit time and crypts elongation were intestinal adaptation that assists the absorption of luminal contents. Therefore, it suggested that J-pouch reservoir had advantage to ileo-proctostomy following total colectomy in dogs.

Adaptation, Physiological↗
PubMed1994

Outpatient adult bronchial asthma in Singapore.

OBJECTIVES: To describe the clinical pattern and drug use in adult bronchial asthma seen in Government polyclinics (primary health care centres). DESIGN: A cross-sectional study using a structured questionnaire. SETTING: The five largest Government polyclinics in Singapore. SUBJECTS: Eight hundred and two subjects aged between 21-58 years drawn from the register of outpatient attendances. The response rate was 63%. RESULTS: The mean age of the study subjects was 37.4 years and the mean age of onset was 19.2 years. Thirty-three percent had onset of asthma under 10 years old. The most commonly reported trigger factors were cold drinks (67%), a change of temperature or humidity (65%), influenza or colds (65%), house dust (58%) and cigarette smoke (37%). In 27%, the work environment was a provoking factor. One-fifth had attacks every night or every day. About half of the patients had FEV1 under 80% of predicted. In the past year, 10% had 4 or more acute attacks requiring emergency attendance, 18% had one or more hospital admissions and 21% had sickness absence from asthma for one week or more. Of the 186 subjects who needed bronchodilators/inhalers 3 times or more a day, only 19.3% were on inhaled steroids. CONCLUSIONS: Considerable morbidity existed amongst outpatient asthmatics. Inhaled steroids appeared to be under-used.

Adult↗
PubMed1994

[Extramedullary blastic crisis of chronic myelogenous leukemia--a case with various additional chromosomal appearance].

We describe a characteristic case of chromosomal abnormalities in a 47-year-old man with chronic myelogenous leukemia (CML). He had been diagnosed with the chronic phase of CML on May 1990, but he refused treatment. He was readmitted in October 1991 because of peripheral lymphadenopathy. Hematologic studies showed that he remained in the chronic phase of CML. There were no additional chromosomal findings in the bone marrow, but cervical lymph node biopsy revealed complete replacement with blastoid cells. The blasts were positive for CD13 and CD33. DNA analysis for the breakpoint cluster region gene showed rearrangement pattern, but immunoglobulin heavy chain joining region genes and T-cell antigen receptor gene rearrangement were not observed. The karyotype of lymph node cells showed various additional chromosomal abnormalities. Therefore, we concluded that the patient had an extramedullary blastic crisis in his peripheral lymph nodes. Abnormal clones were composed of one main clone and three subclones, with the latter occupying more than 10% of the volume each other. Considering the types of the additional chromosomal abnormalities, all four types of clones were thought to have evolved through independent pathways.

Blast Crisis↗
PubMed1993

Effect of dietary protein and urea on in vitro caecal ammonia production from urea and uric acid in cockerels.

1. Single Comb White Leghorn adult cockerels were fed on 50 g/kg protein diet, 200 g/kg protein diet or 50 g/kg protein diet plus urea and in vitro ammoniagenesis from urea and uric acid in the caeca was determined. 2. Four-fold protein intake caused about 4.6-fold increase in caecal ammonia production from urea (P < 0.05), and tended to increase it from uric acid as compared with 50 g/kg protein-fed birds. 3. Dietary urea significantly increased caecal ammonia production from urea and uric acid by about 2 and 3 times as much as those of control birds, respectively (P < 0.05). 4. It is concluded that increased protein intake and the feeding of urea are able to induce ammoniagenesis from urea and uric acid in the caeca of fowls.

Animals↗
PubMed1993

Detection of Mycobacterium leprae DNA in formalin-fixed, paraffin-embedded samples from multibacillary and paucibacillary leprosy patients by polymerase chain reaction.

BACKGROUND: Diagnosis of paucibacillary leprosy is often difficult. A method that could confirm the diagnosis is the polymerase chain reaction (PCR) of M. leprae DNA. This reaction was applied to biopsied tissues of leprotic patients to determine the suitability and sensitivity of the reaction. METHODS: Biopsy samples were taken from previously untreated patients with multibacillary (5 patients) and paucibacillary (3 patients) leprosy, fixed in formalin, and embedded in paraffin. DNA was extracted from paraffin blocks and PCR applied. The sensitivity of the PCR method was tested by using the serially diluted DNA sample as the template. RESULTS: All eight patients showed a positive PCR for M. leprae DNA. The sensitivity was such that a single organism of M. leprae, as counted by staining of the acid-fast bacilli was identified by the PCR. CONCLUSIONS: The PCR method is simple, sensitive, specific, and does not require the use of radioisotopes. It can be applied to the unequivocal diagnosis of paucibacillary leprosy which is difficult by other means. The diagnosis can be obtained within 10 hours.

Blotting, Southern↗
PubMed1993

Induction of combination rules in two-dimensional function learning.

Previous studies have typically found that when people learn to combine two dimensions of a stimulus to select a response, they learn additive combination rules more easily than nonadditive (e.g., multiplicative) ones. The present experiments demonstrate that in some situations people can learn multiplicative rules more easily than other (e.g., additive) rules. Subjects learned to produce specified response durations when presented with stimulus lines varying in length and angle of orientation. When stimuli and correct responses were related by a multiplicative combination of power functions, learning was relatively easy (Experiment 1). In contrast, systematic response biases occurred during the early phases of learning an additive combination of linear functions (Experiment 2) and a more complex (nonadditive and nonmultiplicative) combination of linear functions (Experiment 3), suggesting that people have a tendency to induce a multiplicative combination of power functions. However, the initial biases decreased with practice. These results are explained in terms of a revised adaptive regression model of function learning originally proposed by Koh and Meyer (1991). Differences between the present results and previous results in the literature are discussed.

Adult↗
PubMed1993

Parental body mass index: a predictor of childhood obesity?

Cross-sectional data of 210 Chinese children aged three to 16 years, of whom 29 (13.8%) were obese, and their biological parents were statistically assessed whether the body mass index (BMI = weight/height2) of the parents were predictive of childhood obesity. Using the logistic regression and proportional hazards models to predict the probability of obesity and to control for potential confounding due to the age and sex of the children, families with one parent having a BMI score of 25 or higher were 3.7 times, and families with two such parents were five times more likely to have an obese child than families with no such parent. Childhood obesity was more markedly correlated with the mother's BMI than with the father's BMI. These findings were all stochastically significant (p < 0.05) inspite of the modest sample size. One in two parents with an obese child did not perceive their child to be overweight and 62% of the parents with an obese child did not want their child to lose weight.

Adolescent↗
PubMed1992

Clinical trials of intrasplenic arterial infusion of interleukin-2 (IS-IL-2) to patients with advanced cancer.

We tried a infusion of interleukin-2 (IL-2) of a relatively low dose via an intrasplenic arterial catheter connected to a chronometric infusion (IS-IL-2). Eighteen patients of colorectal cancer with metastases to the liver or lung or of unresectable hepatoma received a 24 hour continuous infusion with low dose recombinant of IL-2 (mainly 8 x 10(5) JRU/day) for 25-40 days. All patients tolerated this protocol of the therapy and the main toxic effects were fever and general fatigue. Such serious toxicity as previously reported by high dose IL-2 therapy was not observed. Data of hepatic and renal functions were normal. IS-IL-2 therapy induced a high incidence of eosinophilia (12/18) and thrombocythemia (12/18). Peripheral natural killer (NK) and LAK activities were augmented in all patients and total white blood cell counts were increased during IS-IL-2 therapy. An increase in IL-2 receptor expression of peripheral blood mononuclear cells and significant rises in numbers of Leu11 (CD16)+, OKM1(CD11)+ and OKIa1(HLA-DR)+ were observed. Of 18 patients 12 were evaluable for their response to therapy. Partial response (PR) was observed in one unresectable hepatoma and 11 demonstrated no change (NC) or progressive disease (PD). Six patients were not evaluable because of additional therapy (3 cases) or decreasing tumor cell markers having no measurable lesions (3 cases). Three patients of colorectal cancer from an unresectable group were presumed to have micrometastases to the liver as suggested by an elevated serum CEA level. After receiving IS-IL-2 therapy they demonstrated a decrease in the serum CEA level for more than 3 years after treatment.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗