Factors predictive of response and survival in patients with metastatic colorectal cancer in Taiwan

5-Fluorouracil in combination with leucovorin has been shown to be active in therapeutic trials of metastatic colorectal carcinoma. In this study, we administered these drugs to 72 patients with metastatic colorectal carcinoma. Thirty-six of them without previous exposure to 5-fluorouracil were treated with weekly bolus injections of 5-fluorouracil (425 mg/m2) and leucovorin (25 mg/m2) supplemented with oral levamisole. Another 36 patients with or without prior 5-fluorouracil treatment received 5-fluorouracil 3,000 mg/m2 and leucovorin 300 mg/m2 in a 48-hour continuous infusion every two weeks. Clinical efficacy and toxicity were assessed by WHO criteria. Variables were tested for relations to response and survival by univariate and multivariate analysis. The response rate was 19.4% in weekly bolus arm and 13.9% in biweekly high-dose infusion arm (P = 0.527). Median survivals in the two arms were 18.4 months (weekly) and 21 months (biweekly) respectively (P = 0.708). Gastrointestinal side effects including nausea, vomiting, diarrhea and mucositia were the major toxicities of these regimens. By multivariate analysis, the only factor to influence response rate was the site of metastases (P = 0.009). The only factor to affect survival was performance status of the patient (P = 0.0001). We concluded that the two 5-fluorouracil based regimens are well-tolerated and shown to have a response rate comparable with previous reports of similar regimens in patients with metastatic colorectal cancer. Only liver metastases seemed to have a better response to therapy. Performance status is the most important prognostic factor in patients with metastatic colorectal cancer.      

Langerhans' cell histiocytosis with thyroid involvement masquerading as thyroid carcinoma

A 28-year-old woman was admitted to our Hospital with a chief complaint of progressive gingival swelling and loosening of teeth over about a year. According to past history, she had received total thyroidectomy 2 years previously due to thyromegaly. The thyroidectomy specimen was at first interpreted as 'poorly differentiated carcinoma of the thyroid'. One year ago, she began to be aware of gingival swelling and loosening of teeth. A gum biopsy was taken and the pathologic features were similar to her 'thyroid carcinoma'. Subsequent investigations, including immunohistochemical stain, showed the gum was heavily infiltrated with histiocyte-like Langerhans' cells which were positive for S-100 protein. Ultrastructural examination of the cells under electron microscope revealed many typical intra-cytoplasmic Birbeck granules. Langerhans' cell histiocytosis was diagnosed. Langerhans' cell histiocytosis with thyroid involvement is extremely rare and may run a relatively indolent course. Even on a retrospective examination, it may easily be confused with poorly differentiated carcinoma of the thyroid. We suspect that this error may have been made on other occasions and that the occurrence of this condition may be underreported.      

Treatment related deaths during induction and in first remission in acute lymphoblastic leukaemia: MRC UKALL X

The benefits of achieving a long term event free survival of 60-70% by using increasingly intense treatment regimens must be weighed against the increased risk of treatment toxicity. From 1985 to 1990, 1612 children with childhood acute lymphoblastic leukaemia (ALL) in the UK were treated on MRC UKALL X with intensive induction therapy, central nervous system directed therapy (cranial irradiation and intrathecal methotrexate), and continuing treatment for two years. There was a randomisation to receive blocks of additional intensification treatment at five weeks, 20 weeks, not at all, or both. The five year disease free survival was 71% for children randomised to two blocks of intensification, a 14% improvement on children randomised to no intensification treatment. Treatment related mortality in this national multicentre study has been analysed for induction and first remission (including those after intensification treatment). There were 38 induction deaths, 2.3% and 53 deaths in first remission, 3.3% (including those from a second malignancy). Thirty one (84%) of the induction deaths followed an infection: bacterial in 22 and fungal in nine. Thirty seven infective remission deaths occurred: bacterial in 11, viral in 16, fungal in seven, and three caused by Pneumocystis carinii pneumonia. Ten of these deaths followed a block of intensification treatment. The majority of noninfective remission deaths followed the development of a second tumour. Risk analysis for an induction death showed girls and children with Down's syndrome to be at greater risk. For deaths in first remission analysis showed an increased risk for bone marrow transplant (BMT) patients and children with Down's syndrome. There was no effect of age and leucocyte count for either group. Most significantly when BMT patients were excluded from the analysis, intensification treatment did not increase the risk of remission death.     

Cyto-adherence studies of the adhesin P50 of Mycoplasma hominis

Recombinant peptides of Mycoplasma hominis adhesin P50 were expressed in Escherichia coli to investigate which regions of the P50 molecule are responsible for cyto-adherence. The respective DNA fragments were obtained by PCR amplification of the p50 gene with the use of mutating oligonucleotides to change the TGA codons of mycoplasma to TGG codons, which are translated in E. coli as tryptophan. The resulting three clones (I, I+II and I+III) contained regions of P50 which closely represent the repeat regions A, A+B and A+C. After expression in E. coli, the polyhistidine-tagged recombinant peptides were purified by metal chelation chromatography. The three recombinant peptides were detected in Western blot analysis by a polyclonal antiserum directed against M. hominis FBG and two P50-specific monoclonal antibodies, BA10 and BG2. Each of the three recombinant peptides I, I+II and I+III was able to adhere to immobilised HeLa cells in an adhesion assay. The cyto-adhesion of the peptides could be inhibited by pre-incubation with the appropriate antibody. Therefore, it is suggested that adherence may be mediated by all regions of the P50 molecule. Attachment of the recombinant peptides to immobilised HeLa cells was inhibited by high mol. wt dextran sulphate (MW 500000), indicating that the respective P50 regions bind to sulphatides on the host cell membrane.     

Noninvasive assessment of regional cardiac adenosine using positron emission tomography.

One of the early metabolic changes associated with myocardial ischemia is the breakdown of adenine nucleotides resulting in the enhanced production of adenosine. In order to image regional cardiac adenosine by positron emission tomography (PET) the enzymatic conversion of adenosine into [11C]-S-adenosylhomocysteine ([11C]SAH) was used in the presence of 11C-labeled homocysteine thiolactone (adenosine + [11C] - homocysteine-->[11C] - SAH + H2O). Following production of an experimental coronary constriction in anesthetized dogs carrier added 1-[11C]-D,L-homocysteine thiolactone (5-27 mCi, 30 mg/kg) was infused over 1 min. This intervention, while hemodynamically ineffective, increased the plasma homocysteine concentration from 2.5 to 306 microM, which thereafter declined with a T1/2 of 28 min to 97 microM after 60 min. During the first minutes following infusion of [11C] homocysteine, the radioactivity concentration in the blood pool, the nonischemic and the ischemic myocardium were similar. Between 20 and 60 min, however, the regional radioactivity concentration was highest in the perfusion area of the stenosed vessel: 6.6% compared to 5.2 and 5.2% of the injected dose per 1 I tissue. The elevated radioactivity concentration was strictly confined to the perfusion area of the occluded artery. Using [35S]-L-homocysteine (20 microCi; 30 mg/kg) chromatographic separation of SAH in tissue extracts confirmed that the radioactivity accumulation was due to trapping of adenosine in the cellular SAH-pool. These experiments provide first evidence that 1-[11C]homocysteine thiolactone can be successfully used to assess regional adenosine formation in the heart with PET via measurement of [11C] SAH accumulation.     

Roxatidine versus ranitidine in the treatment of duodenal ulcers: A randomized double-blind controlled multicentre study in Singapore

Roxatidine acetate, a new H₂ receptor antagonist, was compared with ranitidine in the treatment of duodenal ulcers in a double-blind multicentre study. Eighty-four patients with endoscopically proven duodenal ulcer were randomized to receive 150 mg roxatidine acetate or 300 mg ranitidine at bedtime. Repeat endoscopy was performed after 4 weeks (25–33 days) and if the ulcer had not healed, another endoscopy was performed after a further 4 weeks of treatment. Using per protocol analysis 73.6% of ulcers treated with roxatidine healed at 4 weeks compared to 72.2% of ulcers treated with ranitidine (P=NS). The healing rates at 8 weeks were 92% with roxatidine and 83.3% with ranitidine (P=NS). Using equivalence tests, the healing rate of roxatidine was found to be equivalent to that of ranitidine within a 20% region. Roxatidine users took significantly less antacids than ranitidine users (P < 0.05). There were no significant adverse effects due to roxatidine or ranitidine. Roxatidine is a safe effective drug in the treatment of duodenal ulcers with a healing rate comparable to that of ranitidine.     

Effect of iodide treatment on iodine concentration and volume of endemic non-toxic goitre in childhood

In a total of 195 children and adolescents of both sex (mean age 12.9, range 5-17 years) with endemic non-toxic goitre the thyroidal iodine concentration (IC) was determined using X-ray fluorescent scanning on admission and during iodine (100 micrograms daily) and L-thyroxine (3 micrograms/kg body weight daily) treatment respectively. Additionally the thyroid volume was measured sonographically in a longitudinal study including 46 patients before and after 4-8 months of iodine supplementation (100 micrograms daily). The IC was 305 +/- 144 micrograms/g. It compared well with that of adult goitre patients (288 +/- 109 micrograms/g) and was significantly inferior to the value of normal controls (389 +/- 170 micrograms/g). Under L-thyroxine therapy the IC further decreased (243 +/- 144 micrograms/g), whereas patients receiving iodide showed an increase of the IC (570 +/- 197 micrograms/g). The mean TSH level fell from 2.3 +/- 0.9 microU/ml to 1.4 +/- 0.6 microU/ml. The average T4/TBG (thyroxine binding globulin) ratio showed a slight increase which, however, was not significant. The mean goitre volume decreased by 40%. It was evidenced that iodide is useful not only in the prophylaxis of non-toxic goitre but also as a more physiologic treatment than thyroid hormones, at least for young subjects with simple diffuse goitres.     

Relationship of a leukemia-associated antigen to the presence of lymphoblasts in the peripheral blood in children with acute lymphocytic leukemia

Peripheral blood samples from 57 children with newly diagnosed E- rosette-negative, surface-immunoglobulin negative acute lymphocytic leukemia (ALL) were studied for the presence of a leukemia-associated antigen (ALLA). Ficoll-Hypaque separated cells were tested using a rabbit antiserum to human null lymphoblasts and an indirect immunofluorescent assay. The percentage of ALLA-positive cells were compared to the percentage of lymphoblasts determined by differential counts of a Wright-Giemsa-stained smear of a concurrently obtained peripheral blood sample. The mean ratio of percentage of lymphoblasts to percentage of ALLA-positive cells was 0.90. However, in 13 patients, the ratio of percent of ALLA-positive cells to percent of lymphoblasts was equal to or greater than 2:1. In the blood of 6 additional children (5 newly diagnosed, 1 relapsed patient) in whom no morphologically identifiable lymphoblasts were detected. ALLA-positive cells were present (7%-49%). These results indicate that testing for ALLA-positive cells in a sensitive technique for detection of leukemic cells in children with ALLA-positive ALL.