Folate-based thymidylate synthase inhibitors in cancer chemotherapy

Understanding the relationship between chemical structure and biological properties of folate analogs, particularly their interactions with the target enzymes, transport proteins and folate-metabolizing enzyme, folylpolyglutamate synthetase (FPGS), has enabled the rational design and development of the selective thymidylate synthase (TS) inhibitors with folate-based structures for clinical uses. These compounds specifically inhibit TS devoid of concomitant effects at other loci, unlike 5-fluorouracil (5-FU). ZD1694 ('Tomudex') was designed as a non-nephrotoxic and highly active analog of N10-propargyl-5,8-dideazafolic acid (CB3717), which is a potent TS inhibitor but had unacceptable nephrotoxicity caused by its poor water solubility. The potent cytotoxic activity of ZD1694 is dependent upon active uptake into cells via the reduced folate carrier (RFC), and subsequent rapid and extensive metabolism to polyglutamate forms inside cells. Marked enhancement of the TS inhibitory activity has been noted as the glutamate chain is elongated. Polyglutamation is critical to the biological activity of ZD1694 against tumor and normal proliferating tissues. The retentive property of ZD1694 polyglutamates inside cells led to a single, infrequent administration schedule in clinical studies. ZD1694 has completed phase I and phase II evaluation with activity observed in several tumor types, particularly in colorectal cancer with a 26% objective response rate. A recent European phase III study of ZD1694, randomized against a 5-FU plus leucovorin regimen, demonstrated an equivalent response rate for advanced colorectal cancer (complete or partial responses; 20 versus 17%) and less toxicity than seen with the latter regimen. The newer selective TS inhibitors, which retain potency for TS inhibition but are not substrates for RFC and/or FPGS, are currently under clinical evaluation. These classes of compound may have benefits for circumvention of resistance by virtue of alterations in these protein functions and for the management of toxicity.

Amplification of the thymidylate synthase gene in an N10-propargyl-5,8-dideazafolic-acid-resistant human leukemia, MOLT-3 cell line developed in pteroylglutamic acid, but not in leucovorin

The types of folates used during the development of resistance to methotrexate have been suggested to play an important role in the mechanisms of established resistance. In this study, effects of reduced and oxidized folates on the development of resistance to a thymidylate synthase (TS) inhibitor, N10-propargyl-5, 8-dideazafolic acid (CB3717), were examined in the human leukemia cell line MOLT-3. MOLT-3 cells were made resistant to CB3717 by soft-agar cloning in RPMI-1640 medium with either pteroylglutamic acid (PGA) or a more physiological folate (10 nM leucovorin). A 40-fold CB3717-resistant subline developed in PGA (MOLT-3/CB3717(40)-PGA) showed amplification of the TS gene with a concomitant increased level in the gene expression. A 200-fold CB3717-resistant subline (MOLT-3/CB3717(200)-PGA), which was derived from MOLT-3/CB3717(40)-PGA, showed further enhancement of amplification of the TS gene. In contrast, even a 200-fold CB3717-resistant subline developed in leucovorin (MOLT-3/CB3717(200)-LV) showed neither amplification nor overexpression of the TS gene. Both MOLT-3/CB3717(200)-PGA and MOLT-3/CB3717(200)-LV cells showed decreased membrane transport of PGA as well as methotrexate. These results suggest that the types of folates used during the development of CB3717 resistance may play a role in resistance, and that impaired transport of PGA, in CB3717-resistant MOLT-3 cells developed in PGA, might have accelerated amplification of the TS gene.

Clinical significance of measurements of urinary and serum thrombomodulins in patients with non-insulin-dependent diabetes mellitus

The aim of our study was to elucidate whether serum thrombomodulin (S-TM) and urinary thrombomodulin (U-TM) levels would reflect the pathogenesis of diabetic complications. Studies were conducted in 188 patients with non-insulin-dependent diabetes mellitus (NIDDM) and 132 age-matched healthy subjects. TM was measured by a newly developed enzyme immunoassay. Both S-TM and U-TM levels in NIDDM were much higher than those in healthy controls. S-TM values in NIDDM correlated significantly with age (P < 0.05), HbA1c (P < 0.05), serum 1.5 anhydroglucetol (AG) (P < 0.05) and urinary albumin concentration (UAC) (P < 0.01), respectively. On the other hand, fasting plasma glucose (FPG) (P < 0.001), HbA1c (P < 0 .01), serum fructosamine (P < 0.05) and serum 1.5 AG (P < 0.05) were closely correlated with U-TM values in NIDDM. Patients with clinical nephropathy showed obviously higher S-TM levels (P < 0.05) than patients with latent nephropathy. Furthermore, S-TM values in patients with diabetic proliferative retinopathy increased significantly compared with those in patients without diabetic retinopathy (P < 0.05). When all diabetic patients with normoalbuminuria were studied, no significant changes of S-TM were observed between the no diabetic retinopathy group and the proliferative diabetic retinopathy group.

CONCLUSIONS

The present data suggest that an increase in U-TM reflects the grade of glucose metabolism, whereas an increase in S-TM appears to reveal the advance of diabetic microangiopathy, including nephropathy.

Biological activity and intracellular metabolism of ZD1694 in human leukemia cell lines with different resistance mechanisms to antifolate drugs

The biological activity and cellular metabolism of ZD1694, a novel folate-based thymidylate synthase (TS) inhibitor, were analyzed in a human leukemia cell line, MOLT-3, and its antifolate-resistant sublines with different mechanisms of resistance to methotrexate (MTX), trimetrexate (TMQ) and N10-propargyl-5,8-dideazafolic acid (CB3717). MOLT-3/CB3717(40), which was selected for CB3717 resistance, demonstrated impaired membrane drug transport via reduced folate carrier (RFC) and lower accumulation of [3H]ZD1694-polyglutamates in the cells with a shift in the polyglutamate distribution profile to shorter chain length polyglutamates, indicating an alteration in polyglutamation capacity in this subline. Impaired RFC and reduced rate of polyglutamation could explain the cross-resistance (12-fold) of this subline to ZD1694. On the other hand, there was little or no cross-resistance to this drug in a subline (MOLT-3/TMQ800) reportedly resistant to TMQ through impaired membrane transport for TMQ and an increase in dihydrofolate reductase (DHFR) activity. Total amount of ZD1694 polyglutamated to a level higher than diglutamate was approximately 1.7-fold higher in the TMQ-resistant cells than that in the parent cells, but a low degree of increase in TS activity in the cells counteracted the supposed increase in sensitivity to ZD1694. MOLT-3/TMQ800-MTX10000 cells, which were established by sequential exposure of the TMQ-resistant cells to MTX and were previously shown to amplify mutated DHFR with low affinity for MTX, showed a decreased accumulation of polyglutamated ZD1694 as compared with the parent line and this was consistent with cross-resistance to ZD1694 in this subline. Overproduction of variant DHFR scarcely influenced the sensitivity to this drug. These results indicate that ZD1694 could overcome antifolate resistance through a mechanism such as amplified DHFR activity, and the biological activity of this drug against the cells paralleled the amount of polyglutamated drug inside the cells. Determination of polyglutamation capacity in tumor cells may allow prediction of sensitivity to this drug.

[Clinical evaluation of hepatitis C virus RNA quantification by competitive reverse-transcription PCR]

We have quantified the hepatitis C virus (HCV) RNA by competitive reverse-transcription PCR method (Amplicor) HCV quantification monitor kit) in sera with positive HCV antibody measured by means of the second generation HCV antibody assay. Among the visitors to PL Tokyo Health Control Center for their health examination and the patients to National Defense Medical College Hospital, 123 HCV antibody-positive cases were examined. A positive but low correlation between the amount of HCV-RNA and the titer of HCV antibody (r = 0.508, p value < 0.0001) was obtained. HCV-RNA was not detectable in 19 HCV antibody-positive cases. Among them, 10 cases showed normal ALT values. In the cases with more than 1000 copies/ml of HCV-RNA, the greater the amount of HCV-RNA the higher ALT values were observed, while the titer of HCV antibody was not correlated to ALT. This study demonstrated the dissociation and low correlation between HCV-RNA amount and antibody-titers in some patients, which may recommend direct quantification of RNA for clinical evaluation of the patients with positive-HCV antibody. The quantification of HCV-RNA by such rapid and simple methods can be applicable for the determination of HCV-RNA amount in routine laboratory works.

The results of the "essential laboratory tests" applied to new outpatients--re-evaluation of diagnostic efficiencies of the test items

We have analyzed diagnostic efficiencies of the individual "Essential laboratory test" items when these tests were applied to 520 new outpatients in the division of comprehensive medicine in a teaching hospital. The integration of these test results with history-taking and physical examination resulted in 544 primary clinical diagnoses which corresponded to the patient's illness complained and in 361 additional diagnoses unrelated to their chief complaints but found by chance by the addition of the test results. Clinical usefulness of these test items were variable depending on the disease category, demonstrating a superior diagnostic efficiency in infectious or inflammatory diseases, liver and biliary tract diseases, hematological disorders or metabolic diseases such as hyperlipidemia and diabetes mellitus, but a lesser degree of usefulness in gastro-intestinal or neurogenic diseases. Urine urobilinogen could not establish its clinical usefulness because of extremely low diagnostic sensitivity even in liver diseases. The leukocyte differential count provided confirmatory information for infectious or inflammatory diseases and was helpful for the estimation of the etiologic nature of infectious diseases. This study failed to terminate a controversy for the adoption of sialic acid instead of erythrocyte sedimentation rate (ESR) in the "Essential laboratory test" items, since the former test showed lower sensitivity, even though higher specificity, in infectious or inflammatory status than ESR. Low albumin globulin ratio (A/G) revealed equivalent diagnostic sensitivity and specificity to the elevated levels in alpha 1 and/or alpha 2 globulin fractions in infectious or inflammatory status, being helpful for the evaluation of patient's general condition at a glance. Incidental analysis for diagnostic values of cholinesterase and random blood glucose for the detection of fatty liver and diabetes mellitus, respectively, suggested that these two tests may be included in the "Essential laboratory tests". Simultaneous measurement of serum creatinine and blood urea nitrogen levels was recommended for the ambulatory screening of renal insufficiency, rather than the measurement either alone. The results in this study provide scientific bases on the usefulness of the individual test items and should be taken into account in the next version of the "Essential laboratory tests".

Parathyroid carcinoma with metastatic calcification identified by technetium-99m methylene diphosphonate scintigraphy

We describe herein a case of parathyroid carcinoma accompanied with metastatic calcification identified by technetium-99m methylene diphosphonate (Tc-99m MDP) scintigraphy in the lungs, kidneys and stomach. Parathyroid carcinoma remains a rare disorder despite the increased prevalence of primary hyperparathyroidism. Metastatic calcification is noted infrequently even in primary hyperparathyroidism and it may cause respiratory failure. Tc-99m MDP scintigraphy three months after surgery showed a complete disappearance of Tc-99m uptake in the stomach and an obvious reduction in the kidneys but no significant change in the lungs, indicating metastatic calcification can be reversibly reabsorbed. This case indicates that the adequate excision of parathyroid carcinoma as well as the early detection of metastatic calcification by Tc-99m MDP are obligatory.

The influence of drug-exposure conditions on the development of resistance to methotrexate or ZD1694 in cultured human leukaemia cells

The influence of drug exposure conditions on the development of resistance to methotrexate (MTX) or ZD1694 was studied by treating MOLT-3 human lymphoblastic-leukaemia cells in a continuous or a pulsatile (high-dose, short term) drug-exposure schedule. Continuous exposure of the cells to MTX with stepwise escalation of the drug concentrations resulted in a MTX-resistant sub-line (MOLT-3/MTX(10000)) with impaired reduced-folate carrier (RFC) and increased dihydro-folate-reductase (DHFR) activity. Conversely, a MTX-resistant clone (MOLT-3/MTX. P-9) with unaltered RFC and DHFR activity, but with decreased cellular accumulation of anti-folates, was selected by high-dose short-term treatment of the cells with MTX. MTX resistance in the latter cells was pronounced after short-term rather than continuous-exposure incubation with MTX, suggesting defective polyglutamation of the drug. On the other hand, 2 ZD1694-resistant sub-lines which were established by continuous (MOLT-3/ZD1694. C) or by pulsatile drug-exposure schedule (MOLT-3/ZD1694.P-9) demonstrated extremely low accumulation and poor retention of [3H]ZD1694, with no change in initial drug uptake and little or no increase of thymidylate-synthase (TS) activity irrespective of drug exposure conditions for their establishment. HPLC analysis displayed a virtual absence of ZD1694 polyglutamates in both ZD1694-resistant sub-lines and low accumulation in MOLT-3/MTX.p-9 as compared to the parent line. However, folylpolyglutamate-synthetase(FPGS) mRNA was only moderately decreased in the 2 ZD1694-resistant sub-lines and to an even lesser extent in MOLT-3/MTX.p-9. In addition, gamma-glutamyl-hydrolase(GGH) activity was not increased, but was slightly down-regulated in the polyglutamation-defective sub-lines. These results indicate that the mechanism(s) of the resistance developed may depend not only on drug-exposure conditions while raising resistance but also on the biochemical properties of the drug.

[Pathogenesis-screening tests for liver dysfunction in the asymptomatic patients with elevated ALT values and their diagnostic efficacies in primary care medicine]

We have evaluated the diagnostic efficacies of ultrasonography and hepatitis C virus (HCV) antibody measurement to differentiate pathogenesis of liver dysfunction in the asymptomatic adults with elevated ALT value. Among 4256 visitors to PL Tokyo Health Control Center for their health examination, 463 cases (11%) showed abnormal liver function including elevation of ALT value. Ultrasonography and HCV antibody measurement using the second generation reagent had been applied to 362 cases in order to screen the etiology of liver dysfunction. The ultrasonography succeeded to establish the diagnosis of fatty liver in 137 cases (38%) and 41 cases (11%) demonstrated positive HCV antibody. There were 4 cases with positive HBs antigen, however, it was found that their abnormal liver function was attributed to other etiology such as fatty liver and alcoholic liver dysfunction rather than chronic type B hepatitis. HCV antibody-positive cases showed higher levels of total protein, ZTT, AST, ALT, and lower levels of albumin, A/G, total cholesterol, triglyceride, gamma-GT and cholinesterase value than other cases. HCV antibody titers were not correlated to hepatic parenchymal damage estimated by ALT or cholinesterase value. Only a little correlation was observed between HCV antibody titers and HCV-RNA amounts determined by the competitive reverse transcription-polymerase chain reaction (RT-PCR) method. These results indicate sufficient diagnostic efficacies of ultrasonography and HCV antibody measurement for a pathogenesis differentiation in the asymptomatic patients with liver dysfunction, and these examinations should be employed as the first-step screening tests for the etiology determination of liver diseases in the primary care medicine.

Cellular pharmacokinetics of ZD1694 in cultured human leukaemia cells sensitive, or made resistant, to this drug

We have analysed the cellular metabolism of a novel thymidylate synthase (TS) inhibitor, ZD1694, in MOLT-3 and K562 human leukaemia cell lines sensitive to or made resistant to ZD1694 by continuous exposure of the cells to ZD1694 with stepwise escalation of the drug concentration. The initial cellular uptake of [3H]ZD1694 was greater in K562 cells than in MOLT-3 cells and the drug accumulated approximately 3-fold more in the former cells following incubation with 0.1 microM ZD1694 at 37 degrees C for 24 h. TS and dihydrofolate reductase activities were not significantly different between the two cell lines. After a 30-min incubation with the drug at 37 degrees C, 85% of the total drug (2.3 pmol/mg protein) in K562 cells was found as tri- to pentaglutamates, whereas MOLT-3 cells accumulated less drug in this time (0.83 pmol/mg protein) and polyglutamates of chain length greater than triglutamate were not found to a significant extent. When the incubation time was extended to 24 h, the polyglutamate profile in K562 cells was progressively shifted towards those of long glutamate chain length and 59% of the total cellular drug (204 pmol/mg protein) was identified as the penta form. In contrast, even distribution between tri- and pentaglutamate was observed in MOLT-3 cells. Total cellular polyglutamates were approximately 3-fold higher in K562 cells than in MOLT-3 cells, and this may explain the 2.5-fold difference in the sensitivity to ZD1694 between the two cell lines. Continuous exposure of MOLT-3 and K562 cells to ZD1694 up to 1 microM or 0.1 microM resulted in 1600- and 4200-fold resistant sublines, respectively (MOLT-3/ZD1694.C and K562/ZD1694.C). The resistant MOLT-3 cells showed a markedly lower cellular accumulation and poor retention of [3H]ZD1694 with no significant change of initial drug uptake by 10 min and with a little increase of TS activity. HPLC analysis demonstrated that more than 90% of the 3H co-eluted with the monoglutamate (parent drug) in the resistant MOLT-3 cells, indicating extremely diminished polyglutamation in the cells. On the other hand, cellular uptake of [3H]ZD1694 was extensively impaired in K562/ZD1694.C cells and cellular accumulation of the drug was only 2.5% of that in the parent cells following 24 h incubation with the drug. Neither an increase of TS or dihydrofolate reductase activity nor a change in the polyglutamate formation profile was observed in the resistant K562 cells. These results indicate that the cellular ability to produce the polyglutamate metabolites of ZD1694 must influence the sensitivity of the tumour cells to this drug, and development of mechanisms involved in the ZD1694 resistance may relate to the intrinsic biochemical properties of the cells.

[Separation of methotrexate-polyglutamates by capillary electrophoresis and its application to the measurement of gamma-glutamyl hydrolase activity in human leukemia cells in culture]

We have applied capillary electrophoresis to the separation of methotrexate (MTX)-polyglutamates, and gamma-glutamyl hydrolase (GGH) activities in tumor cells were measured by using this new analytical method. MTX-polyglutamates were sufficiently separated in 15min by capillary electrophoresis with silica fused capillary (phi 50 microns x 75cm), being electrophoresed at 25kV and 30 degrees C in a buffer which contained 20mM sodium tetraborate, 20mM SDS and adjusted pH to 9.5. MTX-polyglutamates eluted were detected at 300nm UV. Cellular extracts obtained from the sensitive and antifolate-resistant human leukemia cell lines, MOLT-3 and K562, were incubated with MTX-glu5 at 37 degrees C for 1, 2 and 4 hr, and the amounts of the degradation products (glu1-glu4) were measured for GGH activity by capillary electrophoresis. There was no significant difference in the production of the metabolites between MOLT-3 and K562 cells (867 +/- 109 vs 799 +/- 56 pmol products/min/1 x 10(7) cells), however, the MTX-resistant MOLT-3 cells with a diminished polyglutamation of folates (MOLT-3/MTX.P-17) and the ZD1694-resistant K562 cells with the impaired membrane transport for reduced folates/MTX/ZD1694 (K562/ZD1694.C) showed decreased activities of GGH (519 +/- 52 and 680 +/- 99 pmol products/min/1 x 10(7) cells, respectively), suggesting the down-regulation of the enzyme in these antifolate-resistant cells concomitant with the intracellular substrate depletion. This study indicates that capillary electrophoresis is a rapid, cost-efficacious method with a sufficient reproducibility in the measurement of GGH activity and must be more suitable for the analysis of clinical samples than HPLC method which requires a large volume of the material.

Effect of hammerhead ribozyme against human thymidylate synthase on the cytotoxicity of thymidylate synthase inhibitors

One of the resistance mechanisms to folate-based thymidylate synthase (TS) inhibitors is the increase in TS activity in tumor cells. Human B lymphoblastoid cell line (W1L2) was made resistant to a lipophilic non-polyglutamatable TS inhibitor (ZM249148), and the subline (W1L2:R179) showed a 20-fold increase in TS enzyme activity with concomitant overexpression of TS mRNA. To overcome the resistance, we designed a ribozyme that can cleave the CUC sequences in a triple tandemly repeated sequence of TS mRNA. Expression of this ribozyme in W1L2:R179 cells transfected with Epstein Barr virus-based expression vector resulted in sensitization to TS inhibitors concomitantly with a decrease of TS expression. The ribozyme expressed in transfectants was shown to be functional in cleaving artificial TS RNA in vitro.

Studies on the inhibitory effects of some acridone alkaloids on Epstein-Barr virus activation

Twenty-five acridone alkaloids from Citrus plants were examined for their inhibitory effects on Epstein-Barr virus activation by a short-term in vitro assay. 5-Hydroxynoracronycine (20) and acrimarine-F (25) showed remarkable inhibitory effects.

Effect of thyrotropin-releasing hormone on serum thyroid hormones: a study in the patients with untreated and treated Graves' disease and subacute thyroiditis

In order to investigate the extrapituitary action of TRH on the thyroid, serum T3, T4, and TSH levels after im administration of TRH were analyzed in 63 patients with untreated hyperthyroid Graves' disease, in 60 euthyroid patients with treated Graves' disease, in 8 patients with subacute thyroiditis, and in 140 healthy subjects. TRH administration in the healthy subjects resulted in a significant increase in serum T3 and T4 levels after 2 h. However, in the patients with untreated hyperthyroid Graves' disease, a significant decrease in serum T3 and T4 levels with undetectable TSH was found 2 h after TRH administration. In the patients with subacute thyroiditis, serum T3 levels also significantly decreased after TRH administration. When a decrease in serum T3 and T4 levels after TRH administration in the patients with hyperthyroid Graves' disease was analyzed in terms of thyroid microsomal antibody and thyroglobulin antibody, a decrease in serum T3 and T4 levels was largest in patients with thyroid microsomal antibody and thyroglobulin antibody. In contrast, an increase in serum T3 and T4 levels in response to TRH in the euthyroid patients with Graves' disease was largest in patients without thyroid autoantibodies. It is concluded that TRH acts directly on the thyroid to suppress the thyroid hormone secreting activity in the absence of circulating TSH and that thyroid autoantibodies affect thyroidal response after TRH administration.

Ten-year follow-up study of thyroid function in euthyroid patients with simple goiter or Hashimoto's thyroiditis

In an attempt to study the natural course of Hashimoto's thyroiditis and simple goiter, 74 euthryroid patients with Hashimoto's thyroiditis and 212 patients with simple goiter were followed for 10 years. In 204 patients with simple goiter (96.2%) it remained as a simple goiter throughout the observation period, whereas 8 patients (3.8%) later had Hashimoto's thyroiditis as evidenced by the appearance of circulating thyroid autoantibodies. These 8 patients had HLA typing significantly different from that of control subjects. None of the patients with simple goiter had hyperthyroid Graves' disease despite the fact that 17.5% of those patients had mild to moderate exophthalmos with either Moebius' sign or von Graefe's sign. In contrast, 12 patients with Hashimoto's thyroiditis (16.2%) had exophthalmos with Moebius' sign and/or von Graefe's sign, and 4 of 12 such patients later had hyperthyroid Graves' disease. TSH binding inhibitory immunoglobulin was detected in 3 of 4 such patients with hyperthyroid Graves' disease. Forty-nine patients with Hashimoto's thyroiditis (66.2%) still remained euthyroid but 20 of those (27.0%) turned into hypothyroidism during the 10-year follow-up.

Hyperuricemia in patients with hyperthyroidism due to Graves' disease

The effects of hyperthyroidism on uric acid metabolism were investigated. First, the serum uric acid level was measured in 92 patients with hyperthyroidism due to Graves' disease, eight patients with subacute thyroiditis, six patients with hypothyroidism, and 70 sex- and age-matched controls. Second, the correlation between serum thyroxine (T4) and serum uric acid was obtained in hyperthyroid Graves' disease patients before and during antithyroid drug therapy. Finally, uric acid clearance (CUA) was determined in untreated patients with hyperthyroidism due to Graves' disease. Serum uric acid was significantly elevated in patients with hyperthyroidism, and the elevation correlated well with serum T4 before treatment as a group and during treatment in each patient. A significant elevation of serum uric acid was not present in patients with a transient mild thyrotoxicosis due to subacute thyroiditis. Serum uric acid was significantly decreased in patients with hypothyroidism. Renal excretion of uric acid clearly increased in hyperthyroid patients, and CUA also increased. The increase in CUA corresponded to the increase in renal plasma flow (RPF), which was measured by p-aminohippuric acid clearance. The fractional excretion of uric acid as determined by CUA/glomerular filtration rate (GFR) was similar and within the normal range in hyperthyroid patients and normal controls. A significant inverse correlation between CUA and serum uric acid concentration was present in hyperthyroid patients as in normal controls, indicating that the renal handling of uric acid in the tubule affected uric acid excretion.(ABSTRACT TRUNCATED AT 250 WORDS)

Expression of variant dihydrofolate reductase with decreased binding affinity to antifolates in MOLT-3 human leukemia cell lines resistant to trimetrexate

Various alterations of the dihydrofolate reductase (DHFR) gene are involved in resistance. In order to understand the mechanism that induce such gene alterations in human leukemia cells, we studied the expression products of DHFR gene in trimetrexate (TMQ)- and/or methotrexate (MTX)-resistant sublines derived from a MOLT-3 human leukemia cell line. A 200-fold TMQ-resistant subline (MOLT-3/TMQ200) expressed the mutated DHFR mRNA, with a base change (T-->C) at the second position of codon 31, as well as the wild type gene. A MTX-resistant subline derived from MOLT-3/TMQ200 (MOLT-3/TMQ200-MTX500) showed a further increase in the expression of the mutated DHFR mRNA, compared to MOLT-3/TMQ200, with a marked decrease of expression of the wild type DHFR mRNA, which is confirmation of amplification of the mutated DHFR gene. By contrast, a 10,000-fold MTX-resistant subline (MOLT-3/MTX10,000) over-expressed the wild type DHFR mRNA, which is confirmation of amplification of the wild type gene. Increased levels of the DHFR enzyme in these sublines were proportional to expression levels of the DHFR mRNA. The DHFR enzyme expressed in MOLT-3/TMQ200-MTX500 cells showed a 40-fold increase in the Ki values for both MTX and TMQ, compared with values for the wild type DHFR expressed in both MOLT-3/MTX10,000 and its parent cell line. These findings suggest that the altered DHFR gene, which was introduced in MOLT-3 cells by exposure to TMQ, gave rise to a variant enzyme with reduced affinity to antifolates, and that complex DHFR alterations confer drug-resistant phenotypes in antifolate-resistance. Structural difference between the antifolates could be important in the introduction of the differential DHFR gene alterations in the antifolate resistance.

[Application of inflammation markers in the "essential laboratory tests" to new outpatients and analysis for the efficacious selection of these items]

We have re-evaluated the usefulness of the inflammation markers in the "essential laboratory tests" advocated by Japan Society of Clinical Pathology and analyzed for efficacious selection of these items by applying these tests to 349 new outpatients visited Comprehensive Medicine, National Defense Medical College. Among the patients with "tentative initial diagnoses" of infectious or inflammation-related diseases (133 cases), the diagnoses were confirmed in 102 patients by positive inflammation marker(s), whereas additional 22 cases with the diagnoses other than inflammation-related diseases were found to be in the inflammatory status by these tests. Elevated C-reactive protein (CRP) levels were not correlated with the leukocyte number, however, neutrophilia (neutro. > 70%) and/or left shift of the neutrophils (stab > 15%) were demonstrated in approximately 50% of the patients with elevated serum CRP levels. Increases of serum sialic acid highly accompanied with increases of CRP, alpha 1 or alpha 2 fraction of serum protein and elevation of erythrocyte sedimentation rate (ESR), indicating that serum sialic acid levels reflected more strictly inflammatory status than ESR. There is a relatively good correlation (r = 0.813) between serum sialic acid values and the total amounts of alpha 1 and alpha 2 protein fraction, while poor correlations were shown between CRP and sialic acid values (r = 0.606), or ESR and sialic acid values (r = 0.671). These results indicate that (1) simultaneous measurements of CRP, leukocyte number and leukocyte differential fraction are useful for the confirmation of early stage of inflammation and evaluation of the nature of infectious diseases; (2) measurement of serum sialic acid levels is more desirable for the evaluation of inflammatory status than ESR; and (3) serum protein profile can be substituted by sialic acid for the evaluation of acute inflammatory status alone.

Chondroitinase ABC-resistant sulfated trisaccharides isolated from digests of chondroitin/dermatan sulfate chains

Four kinds of sulfated trisaccharides resistant to chondroitinase ABC were isolated after chondroitinase B or ABC treatment of dermatan sulfate or various chondroitin sulfate isomers, respectively. Their composition was determined by chemical analysis and fast atom bombardment-mass spectrometry. Their structures were characterized by chondroitinase ACII digestion in conjunction with HPLC, and 500-MHz one- and two-dimensional 1H NMR spectroscopy. All the four trisaccharides have in common the core saccharide sequence, alpha-L-delta 4,5HexpA-(1-->3)-beta-D-GalpNAc-(1-->4)-D-GlcpA. A monosulfated component isolated from shark scapular cartilage chondroitin sulfate C or bovine aorta dermatan sulfate was elucidated as alpha-L-delta 4,5HexpA-(1-->3)-beta-D-GalpNAc6SO3(-)-(1-->4)-D-GlcpA or alpha-L-delta 4,5HexpA-(1-->3)-beta-D-GalpNAc4SO3(-)-(1-->4)-D-GlcpA , respectively. A disulfated component obtained from shark scapular cartilage chondroitin sulfate C or squid cartilage chondroitin sulfate E was identified as alpha-L-delta 4,5HexpA2SO3(-)-(1-->3)-beta-D-GalpNAc6SO3(-)-(1-->4)-D-G lcpA or alpha-L-delta 4,5HexpA-(1-->3)-beta-D-GalpNAc4SO3(-)6SO3(-)-(1-->4)- D-GlcpA, respectively. These trisaccharides are derived from the reducing termini of the parent polysaccharides. Some of the trisaccharides could be derived from the reducing termini exposed by the peeling reaction during the alkaline treatment while some others may represent the cleavage sites exposed by tissue endo-beta-D-glucuronidase(s), indicating the presence of such enzyme(s) which may release chondroitin/dermatan sulfate fragments from proteoglycans.

Development of glycoside-bound radiopharmaceuticals: novel radioiodination method for digoxin

We combined 2-hydroxy-3-methylbenzoylhydrazide (HMBH) with glycosides as a novel method for the radioiodination of physiologically active glycosides. This method was tested using digoxin, which is one of the cardiac glycosides. A digoxin-HMBH conjugate was synthesized by periodate cleavage of the third sugar ring, and was readily radiolabeled with Na[125I] by the chloramine-T method. 125I labelled digoxin-HMBH conjugate retained Na+, K(+)-ATPase binding in vivo and in vitro, and also retained immunoreactivity to an anti-digoxin antibody. Thus, this 125I labelled digoxin-HMBH conjugate represents a potential radiopharmaceutical for Na+, K(+)-ATPase imaging, as well as for the radioimmunoassay of digoxin.

Basic evaluation of 67Ga labeled digoxin derivative as a metal-labeled bifunctional radiopharmaceutical

To develop metal-labeled digoxin radiopharmaceuticals with affinity with anti-digoxin antibody as well as Na+,K(+)-ATPase, a digoxin derivative conjugated with deferoxamine was synthesized. The derivative had a high binding affinity with 67Ga at deferoxamine introduced to the terminal sugar ring of digoxin. The 67Ga labeled digoxin derivative showed enough in vitro binding affinity and selectivity to anti-digoxin antibody as well as Na+,K(+)-ATPase. The 67Ga labeled digoxin derivative is considered to be a potential metal-labeled bifunctional radiopharmaceutical for digoxin RIA as well as myocardial Na+,K(+)-ATPase imaging.

[Laboratory tests in primary care medicine: pre-clinical, ambulatory screening test system on the basis of the patient's chief complaints in the initial diagnosis making]

We have explored the efficacious laboratory test system to be performed before the first medical contact with a physician on the basis of the patient's chief complaints and their abnormalities of the "essential laboratory tests" advocated by the Japan Society of Clinical Pathology by analyzing 2,625 complaints from 2,175 new patients visited the outpatient unit of Comprehensive Medicine, National Defense Medical College. The patients with complaints such as general fatigue, fever of unknown origin or reno-urinary symptoms showed higher abnormalities of these diagnostic tests than those in 750 patients performed these tests irrespective of the patient's chief complaints. However, complaints originated from neurological, gastro-intestinal, cardiovascular or respiratory diseases were not associated with abnormalities of these laboratory tests in the patients as compared to those in 750 patients mentioned above. These results indicate that (1) clinical usefulness of the "essential laboratory tests" are variable depending on the patients chief complaints and these tests are recommended for the patients with complaints such as general fatigue, fever of unknown origin or reno-urinary symptoms as pre-clinical ambulatory screening tests before history taking and physical examination to enable to make accurate initial diagnosis and subsequent efficacious medical approach and (2) test items should be selected depending on the patient's chief complaints.

[Detection of alterations of dihydrofolate reductase gene in folate-resistant leukemia cells by in vitro enzymatic amplification]

Three methods for analyzing the products of polymerase chain reaction were applied to detect complex alterations of dihydrofolate reductase (DHFR) gene, in order to assess their value in detection of folate-resistance in leukemia cells. A single point mutation in the second position of codon 31, a T-to-C transition, in trimetrexate (TMQ) resistant MOLT-3/TMQ200 cells was detected by either allele-specific oligonucleotide hybridization or restriction pattern of the PCR product. These two analyses allowed us to detect not only the presence of the mutation, but also the amplification of the mutated gene in TMQ-methotrexate (MTX) doubly-resistant MOLT-3/TMQ200-MTX500 cells. The base change was confirmed by direct sequencing method of the PCR product. Using these analyses of the PCR product, the complex alterations of DHFR gene are to be examined in leukemic patient cells.

The prognosis of idiopathic portal hypertension in Japan

To clarify the factors relating to the prognosis of patients with idiopathic portal hypertension (IPH), we followed 171 patients with IPH until the end of 1990, who were registered in the database among those with abnormal portal circulation as of 1985 in hospitals of Japan. During the follow-up period, twenty patients died; 6 from gastro-intestinal tract bleeding, 5 from hepatic insufficiency and 9 from other causes. Cox's proportional hazard model suggested that male patients (hazard ratio 4.85, 95% confidence interval 1.82-12.94), with a disease onset at less than 40 years of age (H.R.3.94, 95% C.I. 1.31-11.57), and/or with varices (H.R.2.86, 95% C.I. 1.05-7.77) generally had poorer prognoses.

Differential alterations of dihydrofolate reductase gene in human leukemia cell lines made resistant to various folate analogues

In order to clarify a molecular mechanism of folate resistance in leukemia cells, we studied alterations of the dihydrofolate reductase (DHFR) gene in a human leukemia cell line, MOLT-3, and its sublines made resistant to methotrexate (MTX), trimetrexate (TMQ) and N10-propargyl-5,8-dideazafolic acid (CB3717), alone or in combination. Major alterations of the DHFR gene were examined by Southern analysis of high-molecular-weight DNA. The presence of a base change (T-->C) at nucleotide position 91 of the DHFR gene, which is reported to be responsible for the reduced affinity of the enzyme for MTX in an MTX-resistant human colon carcinoma cell, was examined by allele-specific oligonucleotide hybridization. In a 10,000-fold MTX-resistant subline (MOLT-3/MTX10,000), the normal allele of DHFR gene had been amplified. In contrast, a 200-fold TMQ-resistant subline (MOLT-3/TMQ200) and a 30-fold CB3717-resistant subline selected from MOLT-3/TMQ200 (MOLT-3/TMQ200-CB-3717(30)) were shown to have the mutant allele. Furthermore, the mutant allele had been amplified in a 500-fold MTX-resistant subline, which was established by the continuous exposure of the MOLT-3/TMQ200 cells to stepwise increases of drug concentration and designated as MOLT-3/TMQ200-MTX500. On the other hand, a 40-fold-resistant subline to CB3717 alone (MOLT-3/CB3717(40)) showed the normal allele without amplification. These data suggest that complex alterations of the DHFR gene are involved in the molecular mechanisms of folate resistance that can be differentially introduced into leukemia cells by exposure to various folate analogues, alone or in combination.

MDR1 (multidrug resistance) gene expression in adult acute leukemia: correlations with blast phenotype

Resistance to multiple chemotherapeutic agents is related to the production of P-glycoprotein, a transmembrane drug efflux pump that is encoded by the multidrug resistance gene (MDR1). To detect low-level or heterogenous expression of the MDR1 gene in acute leukemia, we have developed sensitive, specific and semi-quantitative protocols for measuring levels of MDR1 mRNA, based on the polymerase chain reaction. Using this assay, we screened blasts from 20 patients with untreated adult acute leukemia for evidence of MDR1 gene expression. The level of MDR1 mRNA was normalized to beta 2-microglobulin mRNA and was defined by reference to the highly resistant trimetrexate-selected leukemia cells MOLT-3/TMQ200 (1.80). MDR1 mRNA was observed in 14 out of 20 patients. Higher MDR1 mRNAs were observed in three patients with phenotypes of undifferentiated or minimally differentiated nonlymphocytic acute leukemia, as compared with other types of acute leukemia (0.98 vs. 0.25). In contrast, lower MDR1 mRNAs were found in five patients with acute promyelocytic leukemia, as compared with other types of acute leukemia (0.08 vs. 0.45). These findings suggest that MDR1 gene expression is correlated with the leucocyte differentiation stage of leukemia. MDR1 gene expression may, in part, explain the responsiveness to chemotherapy in these distinct subtypes of acute leukemia.

[Comparable evaluation of serological diagnostic tests (ELISA, IFA and PA methods) for the detection of anti-Borrelia burgdorferi antibody]

We have evaluated the usefulness of the enzyme-linked immunosorbent assay (ELISA), indirect fluorescent antibody assay (IFA) and particle agglutination (PA) method as serological screening tests for Lyme-borreliosis. Serum samples obtained from two patients with Lyme-borreliosis showed marked high antibody titers for Borrelia burgdorferi when measured by these methods. Of the serum of 368 healthy members of the Self-Defense Force in north-eastern Japan screened for the antibody to B. burgdorferi, 8.4%, 3.7%, 4.6% were found positive by the ELISA, IFA, and PA method, respectively. However, Western blot analysis of these "positive" sera demonstrated no identical bands to those seen in the serum from the patients with Lyme-borreliosis. While 85% and 15% of Treponema pallidum hemagglutination test (TPHA)-positive sera (20 samples) showed a false-positive reaction by the ELISA and IFA method, respectively, no cross-reaction to the anti-B. burgdorferi antibody was observed in these sera by the PA method. The analysis of the serum of the patients with autoimmune diseases (rheumatoid arthritis; 11 cases, systemic lupus erythematosus; 46 cases) by the ELISA and PA methods resulted in a cross-reaction to some extent, which suggested that the antibodies produced by autoimmune mechanisms such as the anticardiolipin antibody can cause a cross-reaction to the anti-B. burgdorferi antibody. These findings indicate that the PA and ELISA rather than the IFA method should be recommended for rapid and conventional screening of Lyme-borreliosis and that serum "positive" for the anti-B. burgdorferi antibody determined by these tests should be confirmed by Western blot analysis to negate the cross-reactions.

N10-propargyl-5,8-dideazafolic acid (CB3717): inhibitory effects on human leukemia cell lines resistant to methotrexate or trimetrexate

The inhibitory effects of N10-propargyl-5,8-dideazafolic acid (CB3717), a quinazoline antifolate and a potent thymidylate synthase inhibitor, were evaluated in human leukemia cell lines resistant to methotrexate (MTX) and trimetrexate (TMQ). MTX-resistant MOLT-3 cell lines, MOLT-3/MTX200 and MOLT-3/MTX10,000, were cross-resistant to CB3717; however, the degree of resistance was only tenfold for both cell lines, and increased dihydrofolate reductase activity in MOLT-3/MTX10,000 had little influence on the degree of CB3717 resistance. The MOLT-3 cell line made resistant to TMQ, MOLT-3/TMQ200, was as sensitive to CB3717 as the parent line. The cell growth inhibitory effect of CB3717 on MOLT-3 was reversed by the addition of thymidine. Leucovorin also partially reversed CB3717-induced growth inhibition. Cellular uptake of MTX and 5-methyl-tetrahydrofolate was hindered by the presence of a high concentration of CB3717, whereas TMQ uptake was not influenced by CB3717. CB3717 appears to enter the cells not only through reduced folate transport system, but by other route(s). CB3717 does not share the transport pathway with TMQ. Our observations that MTX-resistant cells with increased dihydrofolate reductase are not more resistant than cells without increased enzyme activity, and that TMQ-resistant cells are not cross-resistant to CB3717, may have clinical relevance.

Effect of verapamil on the class I major histocompatibility complex antigen expression in K562 chronic myelogenous leukemia cells treated with recombinant human interferon-gamma

The effects of various compounds which modulated the intracellular signal transduction on the induction of class I major histocompatibility complex (MHC) antigens by recombinant human interferon-gamma (rIFN-gamma) were investigated using K562, chronic myelogenous leukemia cells. Class I or class II MHC antigens were not expressed in untreated K562 cells and rIFN-gamma (600 units/ml) weakly induced class I antigens on the cells. Among the compounds tested, verapamil but not the calcium ionophore A23187 enhanced the rIFN-gamma-induced class I antigen expression at both the surface molecule and mRNA levels and enhancement by verapamil occurred in a dose-dependent manner at non-toxic concentrations examined (approximately 50 microM). Verapamil alone had no inducible effect on MHC antigen expression. Deprivation of Ca2+ in culture medium by ethylene glycol-bis(beta-aminoethyl ether) N,N,N',N'-tetraacetic acid (EGTA) could not cause an enhancement of class I antigen induction by rIFN-gamma. Simultaneous exposure of K562 cells to rIFN-gamma (600 units/ml) and recombinant human tumor necrosis factor (rTNF; 1000 units/ml) in combination with verapamil (50 microM) resulted in a further increase of class I antigens in the cells. The expressions of c-myc oncogene in K562 cells were not changed when the cells were treated with rIFN-gamma (600 units/ml) or verapamil (50 microM), either alone or in combination. These results indicate that verapamil synergistically interacts with rIFN-gamma on the class I antigen induction in K562 cells irrespective of c-myc gene expression and that class I antigen induction in this cell line may not be relevant to calcium influx triggered by IFN-gamma.

Noonan syndrome presenting growth hormone neurosecretory dysfunction

Noonan syndrome has been diagnosed by the characteristic physical stigmata for more than two decades. Recent studies of growth hormone secretory pattern provide a new category of growth hormone neurosecretory dysfunction to characterize short stature. We describe herein a case of growth hormone neurosecretory dysfunction in a 16-year-old boy with Noonan syndrome. Growth hormone neurosecretory dysfunction was diagnosed primarily based on the low amplitude and small numbers of the spontaneous bursts of growth hormone secretion during 12-hour nocturnal growth hormone sampling. Treatment with synthetic human growth hormone has markedly accelerated the growth velocity for one year and a half. This case notes the wide spectrum of short stature in Noonan syndrome and the effectiveness of treatment with human growth hormone.

["Essential laboratory tests" in primary care medicine--experiences in Comprehensive Medicine, National Defense Medical College]

The "essential laboratory tests" were applied to 1,026 new patients visiting the outpatient unit of Comprehensive Medicine, National Defense Medical College, to determine the usefulness of these tests in primary care medicine. The "essential laboratory tests" have contributed to the establishment of the initial diagnosis or confirmation of the "tentative initial diagnosis", and to the estimation of the nature or degree of seriousness of the disease. In addition, other diseases not related to the patient's chief complaint could be screened in 32% of the new patients examined with these tests. The "essential laboratory tests" were also found to be useful for the estimation of the presence of malignant tumors in 12 patients with various kinds of malignancies as well as the estimation or evaluation for such conditions as infection or inflammation, anemia, liver or renal dysfunction, and the ambulatory screening of metabolic diseases including hyperlipidemia, liver or urinary tract diseases. In conclusion, simultaneous performance of the "essential laboratory tests" with the history taking and the physical examination will provide important medical information in primary care medicine.

High myocardial accumulation of radioiodinated digoxin derivative: a possible Na,K-ATPase imaging agent

In view of the high binding ability of cardiac glycosides to the myocardial Na,K-ATPase, radioiodinated digoxin derivatives were surveyed as candidates for myocardial imaging, with particular emphasis on the noninvasive monitoring of cardiac glycoside therapy. Among the radioiodinated digoxin derivatives surveyed, 125I-digoxin-iodohistamine(bis(O-carboxymethyloxime)) showed the highest accumulation in the myocardium and similar binding ability to Na,K-ATPase as digoxin itself against ouabain displacement, as indicated by in vivo and in vitro studies. Based on these results, 123I labeling of digoxin-histamine(bis(O-carboxymethyloxime)) and imaging in a dog demonstrated uptake in the myocardium.

Serial changes of the serum macrophage colony-stimulating factor level after cytoreductive chemotherapy

To investigate the physiologic role of macrophage colony-stimulating factor (M-CSF) in hematological recovery from bone marrow hypoplasia, we used an enzyme-linked immunosorbent assay to measure serial changes of the serum M-CSF level during 25 intensification chemotherapy courses given to seven patients with acute non-lymphocytic leukemia who were in complete remission. Three M-CSF peaks were observed during therapy: the first peak was during or just after chemotherapy, the second peak was around the leukocyte nadir, and the third peak coincided with a rapid increase in the monocyte count. We could find no significant correlation between the height of the second peak and the time from the initiation of therapy to hematological recovery. On the other hand, there was a significant positive correlation between the height of the second peak and the interval from the last day of chemotherapy to the peak (r = 0.62, p = 0.001), and there was a significant negative correlation between the peak height and the time from the peak until hematological recovery (defined as a neutrophil count of over 500/microliters (r = -0.63, p = 0.001) and a leukocyte count of over 1,000/microliters (r = 0.55, p = 0.008)). However, we found only a weak correlation between the peak height and monocyte recovery. These data suggest that increased M-CSF levels lead to the stimulation of granulocyte progenitors, and that we can predict the time of neutrophil recovery by monitoring the serum M-CSF level and finding its peak.

[Laboratory tests in primary care medicine: "essential laboratory tests" (2). Usefulness of hematological, biochemical and serological tests in diagnosis of new outpatients]

We evaluated diagnostic utility of the hematological, biochemical and serological tests comprised in the "essential laboratory tests" advocated by the Japan Society of Clinical Pathology in 1,026 new patients visiting the outpatient unit of Comprehensive Medicine, National Defense Medical College. Of 750 evaluable patients, 52 showed anemia associated with such conditions as ulcer or cancer of digestive tract, inflammatory disease, or renal failure. Leukocytosis (greater than 9,000/microliters) was found only in 25 of 112 CRP-positive (greater than 0.3 mg/dl) patients, suggesting bacterial infection. Forty-four patients showed hypoproteinemia and/or hypoalbuminemia indicating chronic conditions including liver and inflammatory disease. Elevation of serum creatinine level was found in 4 patients subsequently diagnosed with renal failure, whereas 32 patients demonstrated elevated BUN. After application of the "essential laboratory tests", 97 patients were diagnosed with hyperlipidemia (total cholesterol greater than 230 mg/dl and/or triglyceride greater than 250 mg/dl). Determination of serum enzyme activity was useful not only for the diagnosis of liver dysfunction or biliary tract disease but also for those of hematological malignancies or myogenic disorders; however, in patients with abnormal values of LDH, gamma-GT and ALP, clinical significance was not clarified in 53%, 38% and 59%, respectively. These results indicate that the "essential laboratory tests" are useful in the following aspects of primary care medicine: for (1) estimation of the degree or nature of infection or inflammatory status; (2) classification of anemia and its relation to underlying diseases; (3) evaluation of patient general condition and protein-producible function of liver; (4) evaluation of renal function; (5) ambulatory screening for metabolic diseases such as hyperlipidemia; and (6) diagnosis of liver and biliary tract diseases.

The role of folates in the development of methotrexate resistance in human leukemia cell line K562

The effect of reduced and oxidized folates on the development of methotrexate (MTX) resistance has been examined in human leukemia cell line K562 (K562/S). K562/S cells were made resistant to MTX by soft-agar cloning either in RPMI-1640 medium (K562/MTX-PGA) or in folic-acid-free RPMI-1640 medium containing 10 nM leucovorin (K562/MTX-LV). The optimal concentrations of leucovorin for the growth of K562/S, K562/MTX-PGA and K562/MTX-LV cells were 1 nM, 5 nM and 10 nM respectively. K562/MTX-PGA cells were 24-fold resistant to MTX as noted by impaired MTX transport. In contrast, K562/MTX-LV cells were 26-fold resistant to MTX as noted by gene amplification of dihydrofolate reductase. Furthermore cross-resistance to cytosine arabinoside was only demonstrated in K562/MTX-PGA, while the K562/MTX-LV cells showed no significant cross-resistance to cytosine arabinoside. These results suggest that the type and level of folates used during the development of MTX resistance may play a role in the mechanism for MTX resistance. Leukemia cells that are grown in leucovorin might serve as a model for acquired MTX resistance in vivo.

[Usefulness of "essential laboratory tests" for the establishment of the initial diagnosis in new outpatients]

"Essential laboratory tests" advocated by Japan Society of Clinical Pathology were simultaneously performed with the history taking of the present illness and the physical examination in 1,026 new patients visited the outpatient unit of Comprehensive Medicine, National Defense Medical College. We have analyzed the usefulness of the "essential laboratory tests" for the establishment of the initial diagnosis in evaluable 750 patients by comparing the diagnosis made only by the history taking and the physical examination (tentative initial diagnosis) with that included the results of these laboratory tests. The "essential laboratory tests" had contributed to remarkably increased incidences of metabolic and endocrine diseases, liver or biliary tract diseases, renal and urinary tract diseases and anemia after the application of these tests. The initial diagnoses of 61 patients were successfully established by the addition of the "essential laboratory tests" among 157 cases of which tentative initial diagnoses remained undetermined. These tests confirmed the tentative diagnoses in 78 patients, while 78 tentative diagnoses were negated and corrected after evaluation of the results of these tests. Furthermore, the diagnostic tests such as CRP and leukocyte count were useful for the estimation of the nature or degree of seriousness of the disease in 57 patients. In addition, other diseases not related to the patient's chief complaint could be detected in 238 patients (303 total number of diseases) by these tests. These results indicate the usefulness of the "essential laboratory tests" not only for the establishment of more accurate initial diagnosis but also for the screening of the "hidden" diseases such as hyperlipidemia and liver dysfunction.

Relationship between tumor cell density and drug concentration and the cytotoxic effects of doxorubicin or vincristine: mechanism of inoculum effects

When tumor cell density increases, the cytotoxic activity of certain anticancer agents, such as vincristine (VCR) and doxorubicin (DXR), progressively decreases. This phenomenon is termed the inoculum effect. Since VCR and DXR are less active in an acidic environment, we questioned whether the inoculum effects could have resulted from acidification of the medium that may have developed due to the high cell density. However, measurements of the cytotoxic activity of these agents in a pH-controlled medium revealed only a minor correction of the inoculum effects. Second, we wondered whether the inoculum effects that occurred at the high cell density might have been attributable to insufficient amounts of drugs to bind all the binding sites of the cells. To test this hypothesis, we used drug-resistant sublines, which required higher VCR or DXR concentrations for cell killing than did the parent cell line. When higher drug concentrations were used, the dose-response curves generated for low- and high-density cell populations became closer and overlapped each other, resulting in virtual disappearance of the inoculum effects. Measurements of cellular drug levels revealed that at a high cell density, cells accumulated much smaller amounts of both VCR and DXR in parallel with the positive inoculum effect. In contrast, when high concentrations of the drugs were used in drug-resistant cells, differences in the cellular drug contents between low and high cell densities became narrow. Cisplatin (DDP) belongs to a group of drugs that do not produce inoculum effects, and DDP's cytotoxic effects were not influenced by the pH-controlled medium or by the use of drug-resistant cell lines. These observations indicate that the inoculum effects are the result of the unavailability of VCR or DXR molecules to all cellular binding sites when cells at high densities are exposed to drugs. The drug concentration relative to cell density was apparently the major determinant for the inoculum effects seen in VCR- or DXR-induced cell killing.

Application of the new zinc-62/copper-62 generator: an effective labeling method for 62Cu-PTSM

A potential PET flow tracer, 62Cu-labeled pyruvaldehyde bis(N4-methylthiosemicarbazone) (62Cu-PTSM), was prepared using a new 62Zn/62Cu generator. With this 62Cu-labeling method based on a ligand exchange reaction, 62Cu-PTSM was quantitatively obtained by simple mixing of the generator eluate, 62Cu-glycine and PTSM solution for a few seconds. The glycine contained in the 62Cu-PTSM injectate had no significant effect in mouse biodistribution studies. The PET studies of 62Cu-PTSM showed brain images that were not visualized by 62Cu-labeled albumin (a plasma pool tracer), in the dog cranium.

Antitumor activities of new platinum compounds, DWA2114R, NK121 and 254-S, against human leukemia cells sensitive or resistant to cisplatin

(R)-(-)-1,1-(2-amino-methylpyrrorodine)-platinum(II) (DWA2114R), cis-1,1-cyclobutanedicarboxylato(2R)-2-methyl-1,4-butanediammin eplatinum(II) (NK121; CI-973) and glycolate-o,-o'-diammine platinum(II) (254-S; NSC375101D) are new platinum compounds developed in Japan. We studied the antitumor effects of these compounds on the cisplatin (cis-diamminedichloroplatinum, DDP)-resistant human leukemia cell line, K562/DDP. K562/DDP cells were 10-fold resistant to DDP, while the cells showed minimal cross-resistance to carboplatin (2.1-fold) and DWA2114R (3.3-fold), and were as sensitive to NK121 (1.6-fold) and 254-S (1.0-fold) as the parent cells. Increases in exposure time of K562 cells to DWA2114R resulted in progressive shifting of the dose-response curve to the left, or more effective cell growth inhibition of the cells. Time dependency indices (ID80 obtained from dose-response curve after 1 hr-exposure of K562 cells to drug followed by 72 hr-culture without drug/ID80 after 24 hr-exposure) of DDP, NK121 and 254-S were 10, 8 and 20, respectively. A multidrug resistant cell-line, MOLT-3/TMQ200, was as sensitive to platinum compounds as the parent MOLT-3 cells. Little or no influence of tumor cell density was observed in the growth inhibition of MOLT-3 or K562 cells induced by these new compounds even if cells were concentrated to a density of 10(8) cells/ml. These results indicate that NK121 and 254-S may overcome the drug resistance developed in the patients after treatment with DDP. The antitumor effect of DWA2114R is more dependent not only on drug-concentration but also on exposure time than that of DDP, suggesting that continuous infusion rather than bolus administration appears the favorable schedule in clinical trials.

A human leukemia cell line made resistant to two folate analogues, trimetrexate and N10-propargyl-5,8-dideazafolic acid (CB3717)

We established a novel human acute lymphoblastic leukemia cell line made resistant to two folate analogues, trimetrexate (TMQ) and N10-propargyl-5,8-dideazafolic acid (CB3717), by sequential exposure of the 200-fold TMQ-resistant cells (MOLT-3/TMQ200) to CB3717. A 30-fold-resistant subline to CB3717 was selected from the TMQ-resistant cells and designated as MOLT-3/TMQ200-CB371730. This double-folate-resistant cell line was 15-fold more resistant to methotrexate (MTX) than MOLT-3/TMQ200; however, TMQ resistance was decreased to 10-fold as compared to MOLT-3/TMQ200. The doubly resistant cells also showed 2-fold cross-resistance to 5-fluorouracil (5-FU). Equimolar concentrations of leucovorin almost completely reversed the inhibitory effect of MTX on the doubly resistant cells and partially that of CB3717 and TMQ; on the other hand, leucovorin enhanced the inhibitory effect of 5-FU. Thymidylate synthase activities demonstrated little or no difference among these three cell lines, being consistent with no overexpression of mRNA for this enzyme in the doubly resistant cells. MOLT-3/TMQ200 cells displayed classical multidrug resistance; sequential development of CB3717 resistance in the TMQ-resistant cells resulted in an enhancement of the multidrug-resistance phenotype and a concomitant increase of MDR1 mRNA. The development of a complex resistance pattern seen in this double-folate-resistant subline indicates intricacy in the study of drug resistance after multidrug chemotherapy.

[Clinical diagnosis and laboratory data]

Modern medicine can not be practiced without laboratory tests. Laboratory tests play a vital role from the initial stage of clinical examination. The Japanese Society of Clinical Pathology has formed a committee specifically dealing with the effective and economic use of lab tests without missing or duplicating the important tests. As is shown in table 1 in the main text "Essential Laboratory Tests" were initially agreed as those tests a patient should take when visiting a clinic regardless of the complaint. From an early stage, laboratory tests were done simultaneously with history-taking and physical examinations. Then the "Initial Impression" is obtained and "Organ-oriented 1st and 2nd screening tests" and confirmatory tests will be done to make the final diagnosis. To evaluate the validity of the "Essential Laboratory Tests", we performed the tests on 1026 patients who visited our general medicine clinic for the first time. We compared the Initial Impression with or without Essential Laboratory Tests. Cases in which a diagnosis could not be made by history-taking and physical examination were decreased from 17.4% to 8.0% by performing the essential laboratory tests. Diagnoses made without the essential laboratory tests were found to be mistaken in 10.4% and the additional use of the tests was suggested to lead to a more accurate diagnosis. In 110 cases, diseases unrelated to the chief complaints, were discovered. Even for the respiratory tract infection, CRP and WBC count, which were included in the essential laboratory tests, were very informative.

Antitumor efficacy of doxorubicin in combination with cisplatin on human lymphoma cells at various cell densities in vitro

The influence of tumor cell density on the antitumor effect of doxorubicin (DXR) in combination with cisplatin (CDDP) was studied in vitro using DND-39A lymphoma cells. DXR was progressively less effective on colony formation inhibition when cell density was increased from 10(5) to 10(8) viable cells/ml (positive inoculum effect), whereas the effect of CDDP was not influenced by cell densities. At a density of 10(5) cells/ml, inhibition of colony formation was virtually identical irrespective of cells being exposed to DXR and CDDP either simultaneously or sequentially. When cell density was increased to 10(7) and 10(8) cells/ml, sequential exposure to CDDP followed by DXR was more active than simultaneous or reversed order of exposure to the two drugs. These results indicate that for DXR-CDDP combination chemotherapy against the cells at high density, the proper sequence of the treatment should be the administration of CDDP followed by DXR, rather than simultaneous or reversed order of exposure. Inoculum effect may be an additional determinant for the rational development of combination chemotherapy.

Nephrotic syndrome associated with generalized amyloidosis and IgM-monoclonal proteinemia

A 67-year-old woman was admitted for nephrotic syndrome. In spite of the lack of lymphadenopathy, hepatosplenomegaly and serum hyperviscosity, remarkable monoclonal IgM-proteinemia was demonstrated. Amyloid kidney was shown by renal biopsy. However, in the bone marrow and other organs, neither proliferation nor invasion of monoclonal immunoglobulin-producing cells was revealed by immunohistological investigations of the specimens biopsied or examined at autopsy, excluding Waldenström's macroglobulinemia. Immunosuppressive chemotherapy with cyclophosphamide, vincristine and prednisolone was effective in reducing serum IgM, but could not slow the progression of renal failure. This case suggested the association of generalized amyloidosis with excessive IgM-proteinemia caused by a non-malignant mechanism.

The influence of tumor cell density on cellular accumulation of doxorubicin or cisplatin in vitro

The effect of tumor cell density on the cellular pharmacokinetics of doxorubicin (DXR) and cisplatin (CDDP) was studied using MOLT-3 human acute lymphoblastic leukemia cells. As determined by the MTT assay, the growth-inhibitory effect of DXR was approx. 40 times lower when cell density was increased from 10(6) to 10(8) cells/ml (positive inoculum effect), whereas little or no influence of cell density was observed in CDDP-induced cell-growth inhibition. As measured by high-performance liquid chromatography using a fluorescence detector, the cellular accumulation of DXR showed 6- and 18-fold decreases after 1 h incubation when the cells were concentrated from 10(6) to 10(7) and 10(8) cells/ml, respectively. Only at low cell density (10(6) cells/ml) did the amount of DXR in the cells increase with increasing exposure times of up to 6 h. The DXR concentration in the supernatant that was separated from a cell suspension showing a density of 10(8) cells/ml fell to 20% of that obtained at 10(6) cells/ml. The metabolites of DXR, including Adriamycinol and Adriamycinone, were not detectable in the cell extracts or supernatants at any cell density examined. In contrast, the cellular accumulation of CDDP calculated from the platinum concentration, which was measured with a flameless atomic absorption spectrophotometer, was essentially identical at all cell densities examined; moreover, extension of the exposure period resulted in a linear increase in the amount of CDDP in the cells. CDDP concentrations in the supernatants were equally retained, irrespective of cell densities. These observations indicate that the positive inoculum effect shown in DXR-induced cell-growth inhibition results from the decreased cellular accumulation of the drug at high cell densities. We found no influence for cell density on the cellular accumulation of CDDP that might be relevant to the therapeutic potentiation of this drug at high tumor-cell density.

Myocardial accumulation of iodinated beta-methyl-branched fatty acid analogue, iodine-125-15-(p-iodophenyl)-3-(R,S)methylpentadecanoic acid (BMIPP), in relation to ATP concentration

To clarify the relationship between the myocardial accumulation of 125I-15-(p-iodophenyl)-3-(R,S)-methylpentadecanoic acid (BMIPP) and intracellular adenosine-5'-triphosphate (ATP) content, the effect of 2,4-dinitrophenol (DNP, an electron transport uncoupler) on myocardial BMIPP accumulation was studied, in comparison with that of thallium-201-chloride (201Tl-Cl). In the mouse myocardium, DNP decreased the intracellular ATP and ADP levels, without affecting either acyl-CoA synthetase activity or the level of CoA-SH. Following treatment with DNP, decreases in myocardial BMIPP accumulation correlated well with those of ATP, while 201Tl-Cl showed slightly increased accumulation in the myocardium. Thus, in some diseases, BMIPP may be useful in evaluating myocardial ATP levels.

[Laboratory tests in primary care medicine: "essential laboratory tests" (1). Urinalysis]

Japan Society of Clinical Pathology has formed a committee dealing with "lab. tests in primary care medicine". As the first step, they made "Essential Lab. Tests" which were composed of simple qualitative bed-side tests such as urinalysis, Complete blood count (CBC: Hb, Ht, WBC, RBC), CRP, or ESR (Erythrocyte sedimental rate), A/G ratio and biochemical tests if necessary (Table 1). We have performed "Essential Lab. Tests" on 1,026 outpatients who visited General Medicine Clinic for the first time. They consisted of 456 male (age 13-81), and 526 female (age 10-85). This report is the result of urinalysis from "Essential Lab. Tests" of 1,026 patients. 1) The result showed that overall positivity of the urinalysis was 21.3% (when more than one item of the qualitative tests was positive). 2) There was distinctive difference in the positivity of the urinalysis between the sex; i.e. protein and glucose were about twice frequently positive in male, where as occult blood and WBC (Esterase reaction) were 2-3 times more positive in female. 3) Urine protein shows positive in the individual 10-20 yrs old and more than 50 yrs old in both sexes. 4) Glucose was positive in over 40 yrs in male, and occult blood, 40-50 yrs or older in male. 5) WBC shows positive in all age groups in female and 50 yrs or older in male. 6) Positive WBC patients did not necessarily reflect urinary infection in female but nitrites roughly corresponded with urinary WBC in male of 50 yrs or older, meaning probable urinary infection associated with prostatic hypertrophy. 7) Abnormality of urinary sediment corresponded to the positive occult blood and WBC Erastase. 8) Urinalysis is an useful method of screening in primary care medicine.

A case of relapsing polychondritis associated with hemolytic anemia

Relapsing Polychondritis (RPC) is a rare disorder of unknown etiology which affects mucopolysaccharide-rich tissues such as cartilage. A 64-year-old man developed auricular and nasal chondritis with complaints of arthralgia of the hands and cervical pain. The auricular biopsy established the diagnosis of RPC. The hematological data revealed normocytic, slightly hypochromic anemia, a persistently elevated reticulocyte count, slightly increased bilirubin, and decreased haptoglobin. The presence of hemolytic anemia was confirmed by the shortened half-life of erythrocytes and erythroid hyperplasia of the bone marrow. This case illustrates the coexistence of RPC and hemolytic anemia which has been only rarely reported. The pathogenesis of RPC is also discussed may elucidate the pathogenesis of this disease.

A case of postnephrectomy arteriovenous fistula

A rare case of a postnephrectomy arteriovenous fistula involving the major renal vessels is presented herein. This type of postnephrectomy arteriovenous fistula is very unusual; in fact, since first documented in 1934, only 65 cases have been reported in the world literature, including 2 cases from Japan. Even though postoperative arteriovenous fistulae are rare, one should bear this complication in mind when unknown causes of bruit or heart failure develop following surgery.

Plasma atrial natriuretic peptide, plasma renin activity and aldosterone during treatment of hyperthyroidism due to Graves' disease

Plasma atrial natriuretic peptide (ANP), plasma renin activity (PRA) and aldosterone were consecutively measured during methimazole treatment in patients with hyperthyroidism due to Graves' disease. ANP values of untreated hyperthyroid patients varied greatly from patient to patient, but decreased progressively with a decrease of serum thyroid hormone concentration during methimazole treatment. PRA was elevated in hyperthyroid patients but less aldosterone was secreted as evidenced by lower aldosterone/PRA ratio in these patients than in normal subjects and in hypertensive patients treated with thiazide. In addition, aldosterone/PRA ratio increased progressively with a decrease of ANP during methimazole treatment. The data indicated that ANP secretion was increased and ANP thus secreted depressed aldosterone secretion in hyperthyroid patients. Propranolol depressed pulse rate but failed to affect ANP secretion. It is suggested that thyroid hormone specifically acts on myocytes to stimulate ANP secretion but physiologic significance of such increased ANP secretion remains to be solved.