[Assessment of the guidelines for efficacious utilization of laboratory tests in primary care medicine]

The Japan Society of Clinical Pathology has proposed guidelines for efficacious utilization of laboratory tests in primary care medicine. In a series of our studies, attempts were made to assess the usefulness of the "Essential laboratory tests" which are common laboratory tests to be applied for new outpatients regardless of the clinics and disease categories. We looked the individual test item again in the aspect of diagnostic efficiency for the next version of the guideline. An analysis of 1026 new outpatients in Comprehensive Medicine, National Defense Medical College, demonstrated the usefulness of the "Essential laboratory tests" not only for the establishment of more accurate initial diagnosis but also for the screening of the occult diseases unrelated to the patient's chief complaints. Another clinical study with 520 new outpatients established diagnostic efficiency of the individual test item by calculating diagnostic sensitivity, specificity and positive predictive value. There were test items such as urine urobilinogen to be taken away from the guideline because of its extremely low sensitivity, and such as random blood glucose and serum cholinesterase to be added for the screening of urine-glucose negative diabetes mellitus and possible fatty liver, respectively. There have been some controversies in the selection of inflammation markers such as erythrocyte sedimentation rate or serum sialic acid; the former revealed higher diagnostic sensitivity but had lower specificity in infectious or inflammatory diseases than the latter.

Stiff-man syndrome associated with antecedent myasthenia gravis and organ-specific autoimmunopathy

We describe a case of stiff-man syndrome accompanied by diabetes mellitus, Hashimoto's thyroiditis and the antecedent myasthenia gravis. The diagnosis of stiff-man syndrome was made based on not only clinical findings and the characteristic electromyographic pattern but also the presence of antibodies to glutamic acid decarboxylase in the serum and cerebrospinal fluid. Stiff-man syndrome is known to be associated with organ-specific autoimmunopathy including insulin-dependent diabetes mellitus. The present case is the first one that stiff-man syndrome was preceded by myasthenia gravis of organ-specific autoimmunopathy. Stiff-man syndrome in the present case probably represents the one of fully expressed manifestations from the broad spectrum of organ-specific autoimmunopathy caused by the loss of self-tolerance.

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.