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Biomedical subjects

C T Tan

Publications and source records attributed to C T Tan.

At least 109 records · Page 6Linked to original sources
PubMed1987

Phase I and clinical pharmacological study of 4-demethoxydaunorubicin (idarubicin) in children with advanced cancer.

We conducted a phase I and pharmacokinetic study of i.v. idarubicin, a new anthracycline analogue, in 42 evaluable children 1-19 years old. Twenty-seven had leukemia and 15 had various solid tumors. The drug was administered in escalating doses of 10 to 40 mg/m2/course in 3 equal fractions over 3 consecutive days at 14- to 21-day intervals. Myelosuppression and mucositis were the limiting toxicities for short-term administration. Nausea, vomiting, and elevation of liver enzymes and bilirubin were the other toxicities encountered. Peak toxicity occurred 2 weeks after drug administration with median recovery by day 24. All but 4 patients with solid tumors had prior anthracyclines. Mild cardiac function changes without clinical symptoms were observed in 17 of 35 patients measured by serial cardiac evaluations. In addition, there were 4 patients with congestive heart failure. On postmortem examination, 4 patients had changes consistent with anthracycline cardiomyopathy at a prior median total anthracycline dose of 175 mg/m2. The maximum tolerated dose for patients with solid tumors was 15 mg/m2 course in 3 divided doses. Patients with leukemia tolerated 30 mg/m2/course. Six of 15 evaluable patients with acute lymphoblastic leukemia who received greater than or equal to 30 mg/m2 idarubicin achieved a remission (M1 marrow status). The plasma clearance of idarubicin fits a 3-compartment model with a harmonic mean half-life of 2.4 min, 0.6 h, and 11.3 h for alpha, beta, and gamma phases, respectively. Idarubicinol was the only metabolite detected in the plasma and it accumulated during the 3 days of therapy. Idarubicin is similar to daunorubicin in pharmacology and toxicity. While the cardiotoxic dose still must be delineated, the complete remission achieved in multiple relapsed patients with acute lymphoblastic leukemia indicate promising activity in at least that disease.

Adolescent↗
PubMed1987

Cryptococcus meningitis, clinical--CT scan considerations.

Twenty adult cases of cryptococcus meningitis and their cranial CT scan findings were reviewed. Ten patients had abnormal CT scans. The findings were hydrocephalus, gyral enhancement, focal nodules, decreased attenuation in the white matter, and patchy increased uptake of contrast. The CT scan appearance often failed to correspond with symptoms. None of the appearances was specific to the cryptococcal infection. Fourteen patients developed papilloedema during the course of the illness. The majority of the patients who developed papilloedema did not have demonstrable hydrocephalus.

Adolescent↗
PubMed1987

Phase I trial of homoharringtonine in children with refractory leukemia.

Continuous infusion of homoharringtonine was administered to 17 children with refractory leukemia. Ten children with acute lymphoblastic leukemia received a total of 18 courses and seven children with acute nonlymphoblastic leukemia had a total of 13 courses. Doses were escalated from 1.65 to 8.5 mg/m2 for 5-10 consecutive days. Side effects included mild nausea and vomiting and transient changes in liver enzymes. Mucositis and diarrhea were more frequently seen at higher dose levels. Grade 3 hypotension and pain were seen at doses of 7 mg/m2 for 10 days. This is considered to be the maximum tolerated dose in this limited phase I trial. None of these previously heavily treated patients achieved a marrow remission.

Adolescent↗
PubMed1987

Suicidal poisoning deaths in Singapore 1975-1984.

This study presents the pattern of suicidal poisoning deaths in Singapore for 1975 to 1984. A total of 282 suicidal poisoning deaths investigated at the Department of Pathology were retrospectively analysed. It was found that for the ten year period, death by poisoning was the third most popular method of suicide with a mean annual percentage of 10.2%. The most commonly involved suicidal poison was the herbicide, Paraquat, used in 35.1% of the cases. Organophosphate insecticides were involved in 22.3% and drugs were used in 24%. The results of the study suggest that in view of the lethality of Paraquat and its popularity as a suicidal agent, there is a need for stricter controls to restrict the availability of Paraquat to the general population.

Adolescent↗
PubMed1986

Phase I study of carboplatin (CBDCA) in children with cancer.

A phase I study of carboplatin (CBDCA) was performed in 40 children with advanced cancer. A single course of CBDCA consisted of 4 weekly 1-hour infusions followed by a 2-week rest. The starting dose of 100 mg/m2/week was 66% of the maximum tolerated dose in adults. Escalated dose levels given were: 125, 150, 175, and 210 mg/m2. Myelosuppression was dose limiting, with thrombocytopenia more pronounced than leukopenia. There was no evidence of cumulative toxicity. The maximum tolerated dose for children with solid tumors was 210 mg/m2/week X 4. Other side effects included transient nausea and vomiting at the higher dose levels and non-dose-related, reversible changes in creatinine clearance. One patient developed hives. No hepatic toxicity was seen. Among the 28 evaluable patients with solid tumors, one of ten with osteogenic sarcoma had complete disappearance of a lung nodule for 15+ months. Two of four patients with medulloblastoma had partial responses by clinical and computerized tomographic scan for 4 and 10 months. All three responders had received prior cisplatin therapy. CBDCA has major advantages over cisplatin in terms of reduced toxicity. Responses observed in patients previously treated with cisplatin are encouraging. The recommended phase II dose for children with solid tumors is 175 mg/m2/week X 4 with a 2-week rest.

Adolescent↗
PubMed1986

Paralytic shellfish poisoning in Singapore.

Paralytic shellfish poisoning is caused by the ingestion of shellfish meat rendered toxic by exposure to a high level of toxic dinoflagellates during the phenomenon of "red tide". This paper reports the first outbreak of paralytic shellfish poisoning from green mussels in Singapore which resulted in two deaths. Analysis of the mussel meat by a standardised mouse bioassay confirmed the presence of the toxin. An attempt was also made to extend the bioassay to an analysis of the gastrointestinal contents. The clinical features of the condition are presented.

Animals↗
PubMed1984

Bovine serum albumin: characterization of a fatty acid binding site on the N-terminal peptic fragment using a new spin-label.

A new spin-label, 4-(L-glutamo)-4'-[(1-oxy-2,2,5,5-tetramethyl-3L-pyrrolidinyl )amino]-3, 3'-dinitrodiphenyl sulfone, is shown to bind to one high-affinity binding site on bovine serum albumin (K = 5 X 10(4) M-1, n = 1). Analysis of the binding of the spin-label to the amino-terminal half (peptic fragment PB) and the carboxy-terminal half (peptic fragment PA) of BSA, and their complex (PA-PB), indicates that the spin-label binds to a long-chain fatty acid binding site located on PB. The usefulness of the novel specificity of the spin-label in characterizing this binding site is discussed.

Binding Sites↗
PubMed1984

Sequential combination of methotrexate and vindesine in previously treated children with acute leukemia. A phase I-II study.

A therapeutic synergistic effect is seen in animal models when vinca alkaloids are administered after methotrexate. To examine further this interaction in clinical studies, a phase I-II trial was conducted in children with hematologic malignancies in the Department of Pediatrics at Memorial Sloan-Kettering Cancer Center. A schedule of sequential of methotrexate and vindesine was developed which showed effect in acute lymphoblastic leukemia in children in relapse and which was relatively nontoxic. The regimen has also been useful for reinduction for patients who are candidates for bone marrow transplant.

Acute Disease↗
PubMed1984

Deliberate alteration of the visual evoked potential.

Seven out of 12 normal subjects could deliberately produce abnormal pattern-reversal visual evoked potentials (VEPs) which simulated disorders of the anterior visual pathways without detection. In six the mechanism was near-point accommodation and in one eccentric fixation. If voluntary suppression of the VEPs is suspected various modifications to the recording technique may be of value. These include the use of a large check size and stimulus field and binocular stimulation.

Adult↗