[Chromosome findings in multiple myeloma]

Cytogenetic studies were performed on 25 patients with multiple myeloma. Five of 25 patients (20%) had chromosomally abnormal clones. The most common anomalous chromosomes were #1, #10, #12, #3, and #14. Chromosomal abnormalities of t (1 ; 10) (q42 ; q26) and t (1 ; 19) (q11 ; p13.3) were observed consistently in a Ig D myeloma patient. Patients with abnormal karyotypes were considered to be in a clinically aggressive phase because of high percentage of immature plasma cell in bone marrow and to have a poor prognosis. Current status of the chromosome findings in multiple myeloma are reviewed in this article.

T cell receptor-mediated signaling events in CD4+CD8+ thymocytes undergoing thymic selection: requirement of calcineurin activation for thymic positive selection but not negative selection

The goal of this study was to identify the differences of intracellular signals between the processes of thymic positive and negative selection. The activation of calcineurin, a calcium- and calmodulin-dependent phosphatase, is known to be an essential event in T cell activation via the T cell receptor (TCR). The effect of FK506, an inhibitor of calcineurin activation, on positive and negative selection in CD4+CD8+ double positive (DP) thymocytes was examined in normal mice and in a TCR transgenic mouse model. In vivo FK506 treatment blocked the generation of mature TCRhighCD4+CD8- and TCRhighCD4-CD8+ thymocytes, and the induction of CD69 expression on DP thymocytes. In addition, the shutdown of recombination activating gene 1 (RAG-1) transcription and the downregulation of CD4 and CD8 expression were inhibited by FK506 treatment suggesting that the activation of calcineurin is required for the first step (or the very early intracellular signaling events) of TCR-mediated positive selection of DP thymocytes. In contrast, FK506-sensitive calcineurin activation did not appear to be required for negative selection based on the observations that negative selection of TCR alpha beta T cells in the H-2b male thymus (a negative selecting environment) was not inhibited by in vivo treatment with FK506 and that there was no rescue of the endogenous superantigen-mediated clonal deletion of V beta 6 and V beta 11 thymocytes in FK506-treated CBA/J mice. DNA fragmentation induced by TCR activation of DP thymocytes in vitro was not affected by FK506. In addition, different effects of FK506 from Cyclosporin A on the T cell development in the thymus were demonstrated. The results of this study suggest that different signaling pathways work in positive and negative selection and that there is a differential dependence on calcineurin activation in the selection processes.

Effects of 15-deoxyspergualin on experimental autoimmune giant cell myocarditis of the rat

BACKGROUND

The benefits of immunosuppressive therapy for human myocarditis are controversial. The effects of a new immunosuppressant agent, 15-deoxyspergualin (DSG), on rats with experimental autoimmune myocarditis (EAM), an animal model of human giant cell myocarditis, were examined.

METHODS AND RESULTS

Lewis rats were immunized with cardiac myosin in Freund's complete adjuvant on day 0. In the first experiment, the effective doses of DSG required to prevent EAM were investigated. Rats were placed into one of five groups: the control group (A) was administered saline from days 1 to 10; group B, 0.3 mg/kg per day of DSG; group C, 1.0 mg/kg per day of DSG; group D, 3.0 mg/kg per day of DSG, and group E, 10.0 mg/kg per day of DSG. Rats were killed on day 28. The heart weight/body weight ratios of the rats of groups D and E were significantly lower than that of the control group. Macroscopic and microscopic scores for myocarditis decreased in groups D and E. In the next experiment, the effects of delayed administration of DSG in preventing autoimmune myocarditis were studied. Two groups of rats received 3.0 and 10.0 mg/kg per day of DSG from days 6 to 15, respectively. Two other groups of rats received the same doses of DSG from days 11 to 20. No preventive effect of delayed DSG treatment was observed. The effects of long-term, delayed initiation therapy then were evaluated. Rats were administered 10.0 mg/kg per day of DSG from days 6 to 25. The heart weight/body weight ratio and macroscopic and microscopic scores of the rats so treated significantly decreased compared with the controls.

CONCLUSIONS

It was demonstrated that DSG can prevent the development of cardiac myosin-induced autoimmune myocarditis.

Monovalent cation selective channel in the apical membrane of rat inner medullary collecting duct cells in primary culture

Ion channels in the apical membrane of rat inner medullary collecting duct (IMCD) were investigated by the patch clamp technique. Owing to the histological heterogeneity of IMCD, cells were cultured from the lower half of the inner medulla of Wistar rat kidney. Channel activity was rarely seen in cell attached patch, but membrane excision activated multiple units of 28.2 +/- 0.7 pS cation selective channel. A Na or K selective channel was not found. The 28 pS channel showed membrane voltage dependency, no rectification, almost equal permeability to monovalent cations (Na/K/Li/Cs/Rb/NH4 = 1:1.00:0.82:0.97:1.10:1.71) and no significant permeation to anions or divalent cations. Calcium of the cytoplasmic side from 10(-7) M to 10(-4) M affected the mean number of open channels (nPo) dose-dependently in excised patch (IC50 = 5 x 10(-6) M). 1 mM of ATP, ADP, AMP and gadolinium reversibly suppressed nPo to near zero whereas amiloride, cAMP or cGMP had no effect. Multiple conductance substates were frequently observed. These results suggested that this channel belongs to the nonselective cation channels which has been identified in other epithelia and is not responsible for amiloride sensitive Na transport through IMCD cells.

Intraoperative irradiation after palliative surgery for locally recurrent rectal cancer

BACKGROUND

In patients with locally recurrent rectal cancer, long-term disease control and survival is uncommon with single-modality therapy. This report evaluates results achieved at the Mayo Clinic (Rochester, MN) with single- or combined-modality treatment, including intraoperative irradiation.

METHODS

From 1981 to 1988, 106 patients underwent palliative surgical resections at the Mayo Clinic for locally recurrent rectal cancer. None had evidence of extrapelvic disease, and 42 received intraoperative electron beam irradiation (IORT) as a component of treatment. Gross residual disease remained after maximal surgical resection in 34 of the 42 patients and 61 of the patients who did not receive IORT. The IORT dose was 15-20 Gy in 39 patients and 10, 25, and 30 Gy in the other 3. External beam irradiation (EBRT) was administered to 41 of the 42 patients (doses > or = 45 Gy to 38 patients).

RESULTS

Kaplan-Meier survival estimates at 3 and 5 years were analyzed for the 106 patients. Palliative surgical resection alone (12 patients) resulted in a 3-year survival of 8% and a 5-year survival of 0%. Statistically significant factors relative to survival based on the univariate analysis of all patients included amount of residual tumor (microscopic vs. gross, P = 0.032) treatment method (P = 0.005), IORT versus no IORT (P = 0.0006), type of symptoms (P = 0.0075), type of fixation (P < 0.0001), and preoperative Eastern Cooperative Oncology Group status (P = 0.03). For patients who received IORT, 3-year survival with gross residual tumor or presentation with pain was 44% and 43%, respectively. Factors not associated with survival (univariate) included extended versus conventional surgical resection, grade, age, and sex. The 3-year cumulative probability of distant metastasis was 60% in the patients who received IORT and 54% in those who did not. The 3-year local relapse rates were 40% versus 93% in patients who received IORT versus those who did not.

CONCLUSIONS

Although the addition of IORT to external irradiation and maximal surgical resection appears to improve local tumor control and survival in patients who undergo palliative surgical resection for locally recurrent rectal cancer, further gains in treatment are necessary. Considering the high rates of distant metastasis, more routine systemic therapy with 5-fluorouracil (5-FU) leucovorin, 5-FU levamisole, or all three needs to be incorporated into aggressive treatment approaches. In patients with gross residual tumor after maximum surgical resection, local tumor control is inadequate despite treatment combinations including IORT. The evaluation of radiation sensitizers or biologic modifiers during external irradiation and IORT is indicated.

Proliferative capacity of oligodendrocytes in the demyelinating twitcher spinal cord

The proliferative capacity of oligodendrocytes was investigated in the spinal white matter of the twitcher mouse, a murine model of a genetic demyelinating disease globoid cell leukodystrophy (GLD), in which degeneration of oligodendrocytes due to metabolic perturbation has been well documented. In normal mice at 30 and 45 days of age, proliferating cells labeled with 5-bromo-2'-deoxyuridine (BrdU) were scarce, and the majority of BrdU-labeled cells did not immunostain with antibodies for oligodendrocytes, astrocytes, or microglia/macrophages. Only a few cells with markers for oligodendrocytes, carbonic anhydrase (CA), or the Pi form of glutathione-S-transferase (Pi), were labeled with BrdU. In the twitcher spinal cord, total numbers of BrdU-labeled cells were almost 6 times that of the normal littermate mice at 30 days of age, and 28 times at 45 days of age. However, this increase was largely due to an increase of cells labeled with F4/80, a marker for the microglia/macrophages. CA or Pi positive cells only constituted less than 10% of all labeled cells. With progression of demyelination from 30-45 days, total numbers of CA positive or Pi positive oligodendrocytes decreased, but percentages of cells double-labeled with BrdU and CA or Pi remained fairly constant. The results indicated that oligodendrocytes proliferated, to some extent, in the twitcher despite the genetic metabolic defect, and their decrease in number with progression of disease was not due to declined proliferation but rather cellular degeneration as the result of an intrinsic metabolic perturbation.

Hepatitis B virus strains with mutations in the core promoter in patients with fulminant hepatitis

OBJECTIVE

Fulminant hepatitis B can be induced by hepatitis B virus (HBV) strains with mutations in the precore region that cannot encode hepatitis B e antigen (HBeAg). Such mutations are rarely seen in HBV DNA clones from patients with fulminant hepatitis B in the United States and France. Thus, the other mutations in HBV strains causing fulminant hepatitis B need to be identified.

DESIGN

Retrospective clinical, serologic, and molecular biological studies of patients with fulminant hepatitis B.

SETTING

University and city hospitals in Japan.

PATIENTS

43 patients with fulminant hepatitis B.

MEASUREMENTS

The precore region coding for a part of the HBeAg precursor and the core promoter regulating the transcription of precore messenger RNA were sequenced in HBV DNA clones.

RESULTS

A point mutation from G to A at nucleotide 1896 in the precore region was detected in 519 (98%) of 529 HBV DNA clones from 38 patients. Two point mutations in the core promoter, from A to T at nucleotide 1762 and from G to A at nucleotide 1764, were detected in all 130 clones from the remaining 5 patients, who did not have mutations in the precore region, and in 20 (63%) of 32 clones from a patient with chronic hepatitis B who had transmitted HBV to 1 of these other 5 patients. Mutations in the core promoter were also detected in clones from 26 (68%) of the 38 patients with the precore mutation at nucleotide 1896. Neither HBeAg nor antibody to HBeAg was detected in 37 (90%) of the 41 patients tested.

CONCLUSIONS

In Japan, fulminant hepatitis B is closely associated with HBV strains that do not produce HBeAg because of mutations in the precore region, which affect translation of HBeAg, or because of mutations in the core promoter, which affect transcription of the HBeAg coding region.

Molecular cloning and functional characterization of rat plasma protein S

Plasma protein S is a cofactor of activated protein C (APC) in the regulation of the blood coagulation system. Rat protein S homogeneously purified from plasma showed cofactor activity for rat APC, but not for human APC when the APC cofactor activity was assayed using protein S- and C4b-binding protein (C4BP)-depleted human plasma. Rat plasma protein S was separated by gel chromatography into two forms, a free form and a form complexed with C4BP. Rat protein S forms complexes with rat and human C4BP in a solid-phase model with apparent dissociation constants (Kds) of 6.7 x 10(-8) and 1.2 x 10(-8) M, respectively, in the presence of 5 mM Ca2+. Human protein S also forms a complex with solid-phase human and rat C4BP with Kds of 6.3 x 10(-9) and 2.7 x 10(-8) M, respectively. Human C4BP strongly inhibited the APC cofactor activity of both human and rat protein S, whereas rat C4BP was only weakly inhibitory. The degree of the inhibitory activity of C4BP appears to depend on the affinity between protein S and C4BP. In order to evaluate the structure-function relationship of the rat protein S, the complete cDNA sequence of rat protein S was determined. This cDNA of 3,315 bp was composed of a 103-bp 5'-noncoding region, a 2,028-bp coding region that encodes a preprosequence of 41 amino acids, a mature protein S of 634 amino acids and a stop codon, and a 1,184-bp 3'-noncoding region. The rat mature protein S consisted of domains with distinct functions similar to those of human protein S, and with two potential Asn-linked glycosylation sites. The amino acid sequence of the mature form of rat protein S showed 80.4, 78.7, and 79.7% identity with those of human, bovine, and rabbit mature protein S, respectively. These findings suggest that despite the species-specificity of the APC cofactor activity of rat protein S, it is structurally very similar to human protein S. Expression of rat protein S mRNA (approximately 3.5 kb) was demonstrated by RNA blot analysis not only in the liver, but also in the lung, spleen, testis, and uterus of rats.

Isolation of an antioxidant from Penicillium roquefortii IFO 5956

In the search for antioxidants from microbial organisms, we found that Penicillium roquefortii IFO 5956 produced an antioxidant. This antioxidant was isolated from a culture broth of the strain, and its structure was identified to be 2,3-dihydroxy benzoic acid (1). The antioxidative activity of 1 was nearly equal to that of tert-butyl-4-hydroxyanisol (BHA).

Proteoglycan degradation in hemarthrosis. Intraarticular, autologous blood injection in rat knees

We determined the degradation of articular cartilage proteoglycans in a single episode of experimental hemarthrosis in rat knees. The right knee joints of rats were injected once with autologous whole blood. Both knee joints were examined histologically. Biochemical studies of cartilage proteoglycans extracted from the knees were also conducted. Histological examination revealed an accumulation of mononuclear cells in intraarticular fibrin clots and subsynovial layers 8 hours after the injection of blood. Accordingly, initiation of proteoglycan degradation occurred 8 hours after injection of blood, lasting from 1 day of limited degradation to 3 days; recovery then occurred within 7 days. The proteoglycan degradation could be inhibited by 1 mM phenylmethylsulfonyl fluoride, a general serine proteinase inhibitor, 0.1 M 6-aminohexanoic acid, a specific inhibitor of plasminogen activators, 10 mM EDTA, and 10(-6) to 10(-8) M dexamethasone, indicating that the accumulation of mononuclear cells in intraarticular fibrin clots and subsynovial layers may play an important role in cartilage damage.

Hemiresection-interposition arthroplasty for osteoarthritis of the distal radioulnar joint

Hemiresection-interposition arthroplasty of the distal radioulnar joint has been carried out in 12 men. The indication was osteoarthritis with an intact triangular fibrocartilage, or when the fibrocartilage could be reconstructed. The average age was 41 years and average follow up for 53 months. In all the patients, there was relief of pain and a significant increase in movement and in grip strength.

Growth activity in hyperplastic and neoplastic human thyroid determined by an immunohistochemical staining procedure using monoclonal antibody MIB-1

To increase our understanding of the basic biological mechanisms of thyroid diseases, growth activity (GA) in 232 thyroid lesions was determined by immunohistochemistry using monoclonal antibody MIB-1. The GA tended to be higher in hyperplastic lesions, adenomatous goiter (MIB-1-positive cell rate, 0.73%), and Graves' disease (1.68%) than in normal tissue (0.19%). The GA for differentiated thyroid carcinomas (2.00%) was much lower than for adenocarcinomas of other organs, such as breast, lung, stomach and colon (44.67%). Of the thyroid carcinomas, the highest GA was observed in undifferentiated carcinomas (32.67%), and follicular carcinomas (3.18%) showed a higher GA than papillary carcinomas (1.83%). There was no significant difference between the GA of follicular carcinomas and solid/trabecular adenomas, although widely invasive follicular carcinomas showed a higher GA than minimally invasive carcinomas. No significant correlations between GA and patient age, sex, and tumor diameter, metastasis, or histological features were observed in papillary carcinomas. Familial medullary carcinomas showed a higher GA than sporadic tumors. All latent papillary carcinomas had a very low GA. Our findings suggest that immunohistochemical investigation using the antibody MIB-1 contributes to the understanding of growth characteristics and biological activities in thyroid diseases.

Specific restrictions in the progression of Venezuelan equine encephalitis virus-induced disease resulting from single amino acid changes in the glycoproteins

The pathogenesis of Venezuelan equine encephalitis virus (VEE) was examined in the mouse model using V3000, a virus derived from a molecular clone of the Trinidad donkey strain of VEE. These results were compared in parallel experiments with avirulent mutants of VEE derived by site-directed mutagenesis of the clone. Adult mice, inoculated subcutaneously in their left rear footpad with V3000, were followed in a time course study for 6 days in which 15 organs were tested for histopathological changes, for the presence of viral antigen by immunohistochemical staining, for the presence of viral nucleic acid by in situ hybridization analysis, and for content of viable virus. Virus was detected in the footpad inoculation site, but until 12 hr postinoculation (pi), the level of virus did not suggest early viral replication. By 4 hr pi, however, replication of V3000 was evident in the draining popliteal lymph node. At this early time point, no virus could be isolated from any other organ examined. At 12 hr, a significant serum viremia was observed, and virus was detected at a low level in a number of well vascularized organs, including spleen, heart, lung, liver, kidney, and adrenal gland. By 18 hr, high virus titers were present in serum and all the lymphoid organs examined, and these tissues appeared to be the major peripheral sites of V3000 replication. Virus in serum and peripheral organs was cleared by 3-4 days pi. In a second phase of the infection, V3000 invaded the central nervous system (CNS), replicated predominantly in neurons, and persisted in the brain until death by encephalitis. Pathologic findings as well as the results of immunocytochemical and in situ hybridization examination were generally coordinate with virus titration. A site-directed mutant of V3000, V3010, contained a mutation in the gene for the E2 glycoprotein at codon 76 (Glu to Lys) which rendered it avirulent after footpad inoculation. Detection of V3010 replication in the draining lymph node was sporadic and was sometimes delayed to as long as 3 days pi. Infrequent and/or delayed virus spread to other sites also was observed. Analogous experiments were performed with other mutants which were avirulent by the footpad inoculation route: V3014, a mutant differing from V3000 at three loci (E2 Lys 209, E1 Thr 272, and E2 Asn 239), as well as single-site mutants V3032 (E2 Lys 209) and V3034 (E1 Thr 272).(ABSTRACT TRUNCATED AT 400 WORDS)

[Immunohistological study of fibrinolytic factors of head and neck squamous cell carcinomas]

We investigated immunohistochemically the localization of urokinase-type plasminogen activator (u-PA), tissue-type plasminogen activator (t-PA), plasminogen activator inhibitor-1 (PAI-1), plasmin inhibitor (PI), and transforming growth factor-beta (TGA-beta) in tissue sections to examine the relationships between their localization and local invasiveness, tumor size and cervical lymph node metastasis of head and neck squamous cell carcinomas (SCCs). In invasive carcinomas, u-PA, PAI-1 and PI were stained stronger in carcinoma cells than in surrounding connective tissues or normal epithelial cells. However, no relationship was found between cell invasiveness and the localization of t-PA and TGF-beta in invasive SCCs. The expression of these factors was not related to cervical lymph node metastasis or the size of head and neck SCCs. These results suggest a disorder of the fibrinolytic systems of carcinoma cells, and that u-PA play a part in the invasion of head and neck SCCs by degenerating connective tissue.

Enhancement of the intracranial arterial wall at MR imaging: relationship to cerebral atherosclerosis

PURPOSE

To investigate the relationship between intracranial arterial wall enhancement and atherosclerosis.

MATERIALS AND METHODS

Intracranial vertebral arteries of 30 patients and carotid arteries of 62 patients were studied with spin-echo magnetic resonance imaging with contrast enhancement and spatial presaturation. Arterial wall enhancement was graded as follows: stage 1, no substantial enhancement; stage 2, faint or thin area of enhancement; stage 3, definite and thick area of enhancement.

RESULTS

In vertebral arteries, stage 3 enhancement was seen in 11 patients (mean age, 73.7 years) and stage 1 in eight (mean age, 56.4 years). In carotid arteries, stage 3 enhancement was seen in 13 patients (mean age, 71.0 years) and stage 1 in 21 patients (mean age, 39.0 years). In both arteries, stage was well correlated with age (P < .05).

CONCLUSION

Arterial wall enhancement is related to aging and is probably due to neovascularity in association with atherosclerotic plaques. This finding may permit assessment of intracranial atherosclerosis and other vascular diseases.

Atypicality of several antipsychotics on the basis of in vivo dopamine-D2 and serotonin-5HT2 receptor occupancy

An in vivo receptor binding technique was used to evaluate the binding profiles of typical and atypical antipsychotic drugs to striatal dopamine-D2 and frontal serotonin-5-HT2 receptors in a rat brain using more specific ligands than those previously employed. [3H]-YM-09151-2 or [3H]-ketanserin was injected into the tail vein 10 minutes after administration of test drugs. One hour after the ligand injection, radioactivities in the striatum, frontal cortex, and cerebellum were counted to obtain receptor occupancies by the test drugs. Higher ratios of potency in occupying 5-HT2 versus D2 receptors were found for clozapine, RMI-81512, and tiospirone compared to haloperiodol and pimozide. Zotepine, mosapramine, and clocapramine produced ratios that fall between these two groups. Chlorpromazine was exceptional as a typical antispychotic by these criteria. Relatively strong antagonism of 5-HT2 receptors by atypical antipsychotics was confirmed by this in vivo measure of receptor binding using more selective ligands than those used in previous studies.

[A case of cilostazol-induced pneumonitis]

A 73-year-old man had been treated with cilostazol for antithrombotic therapy after a myocardial infarction. Seventy days after the start of cilostazol therapy, he developed dyspnea, dry cough, and fever. He was admitted to our hospital on April 13, 1923. Chest radiography and CT revealed a ground glass appearance. All drugs except isosorbide dinitrate were discontinued and he was treated with steroids under the presumptive diagnosis of drug-induced pneumonitis. Steroid therapy was effective. The result of a lymphocyte stimulation test was positive for cilostazol. Based on the above findings, cilostazol-induced pneumonitis was diagnosed. To our knowledge, there have been no previous reports of cilostazol-induced pneumonitis.

[Adrenalectomy for nonfunctioning adrenal tumors--comparison between open and laparoscopic surgery, and indication for operation]

Since 1977, we have operated on 18 nonfunctioning adrenal tumors. The pathological diagnosis included seven adrenocortical adenomas, three adrenocortical hypeplasias, three ganglioneuromas two adrenal cysts, two myelolipomas and one metastatic cancer. We successfully performed laparoscopic adrenalectomy in 11 of these patients and open surgery in the other 7 patients. In the patients undergoing laparoscopic adrenalectomy, post-operative recovery (fist oral intake, first ambulation, and total convalescence) was remarkably rapid. The indication of adrenalectomy for nonfunctioning adrenal tumors is controversial, but we can not exclude the possibility of malignancy even in small tumors. Therefore, because of the minimally invasive nature of laparoscopic surgery, the indications for operating on nonfunctioning adrenal tumors will be widened by introducing laparoscopic adrenalectomy.

Effects of hypertonic saline and dextran 70 on cardiac functions after burns

The effects of hypertonic saline-dextran (HSD) on cardiac contractility and hemodynamics after burns were studied in anesthetized animals with full-thickness 50% total body surface area burns that were resuscitated with HSD or lactated Ringer solution (LR) alone. No significant difference in cardiac contractility during 6 h postburn was observed between the two groups, as assessed by the end-systolic pressure-volume relationship and the stroke work-end-diastolic volume relationship. An additional bolus of HSD at 6 h postburn caused no significant changes in the end-systolic pressure-volume relationship and stroke work-end-diastolic volume relationship in the burned and sham-burned animals, both of which were resuscitated with HSD. Ten minutes of hemodynamic changes following HSD infusion at 30 min postburn revealed a sudden increase in stroke volume with biphasic responses in left ventricular systolic pressure, which first decreased, then increased, and finally returned to the pre-HSD value. End-diastolic volume was maintained at approximately 110% of the pre-HSD value during this period. We concluded that HSD does not enhance cardiac contractility after severe burns but does produce direct effects on postburn circulation to reduce afterload and augment preload, resulting in a short-lived increase in cardiac output.

Effect of fluoride on the activities of the Na+/glucose cotransporter and Na+/K(+)-ATPase in brush border and basolateral membranes of rat kidney (in vitro and in vivo)

In this study, renal Na+/K(+)-ATPase activity was demonstrated to be strongly suppressed prior to the glucosuria caused by a fluoride dose (NaF 35 mg/kg, i.p.), and the 50% suppression of the enzyme activity was almost at the same dose of NaF, about 30 mg/kg, i.p. to rats. In the rats, renal Na+/glucose cotransporter activity in brush border membranes was not affected by in vivo NaF, whereas the renal Na+/K(+)-ATPase in basolateral membranes showed a dip in activity 3 h after NaF treatment of the whole animal. Moreover, it was suggested from experiments with inhibitors of calphostin C and KT5720 that protein kinase C, but not protein kinase A, may play an important role in the suppression of Na+/K(+)-ATPase following the administration of fluoride to rats. Na+/glucose cotransporter was fairly insensitive to NaF, being competitively inhibited with a Ki of about 100 mM, whereas Na+/K(+)-ATPase was much more sensitive, with a Ki of about 2 mM. From these results, the elevation of urinary glucose excretion after a single dose of fluoride was deduced to be due to suppression of the renal Na+/K(+)-ATPase activity by a direct and/or secondary action of fluoride, rather than of the corresponding Na+/glucose cotransporter activity.

One-step sandwich enzyme immunoassays for human C4b-binding protein (C4BP) and protein S-C4BP complex using monoclonal antibodies

C4b-binding protein (C4BP), a regulatory component in the complement system, binds to an anticoagulant vitamin K-dependent plasma protein S (PS) which acts as a cofactor of activated protein C. We raised monoclonal antibodies against C4BP and PS, and developed two different one-step sandwich enzyme immunoassay (EIA) systems for human total C4BP (assay A) and PS-C4BP complex (assay B) by using a solid phase monoclonal antibody and a horseradish peroxidase-labeled monoclonal antibody (Fab'). The reaction time of the assay was 45 min in both EIA systems: 30 min for the immunoreaction and 15 min for the color reaction. The sensitivities were 12 and 20 mg/l in assays A and B, respectively. Linearity was obtained between 31 and 500 mg/l in both EIA systems. Assay A could detect both uncomplexed C4BP and PS-C4BP complex with equal efficiency so that total C4BP level was not affected by PS. The levels of total C4BP and PS-C4BP complex were found to significantly increase in sera from patients with membranous nephropathy and decrease with liver cirrhosis in comparison with the levels in normal subjects. On the other hand, a difference in the total C4BP and PS-C4BP complex levels was not shown between IgA nephropathy and normal subjects. Affinity column analysis and difference of total C4BP and PS-C4BP complex levels showed that most of C4BP in sera exists as PS-C4BP complex.

Tay-Sachs disease: intron 7 splice junction mutation in two Portuguese patients

A single nucleotide transversion (G-->C) in the 5' donor site of intron 7 of the beta-hexosaminidase alpha-chain gene was identified in two Portuguese patients with infantile Tay-Sachs disease. One patient was found to be homozygous and the other a compound heterozygote with the four-base insertion in exon 11 on the other allele. In fibroblasts from the homozygous patient the beta-hexosaminidase alpha mRNA was observed as a nearly undetectable fast migrating band. Through cDNA-PCR amplification and hybridization with full length alpha cDNA several fragments of smaller size than the normal transcript were detected, most of them lacking exon 7. We propose that this point mutation in the 5' donor site of intron 7 of the beta-hexosaminidase alpha-chain gene is responsible for an inefficient and abnormal processing of the mutant transcript, resulting in functional abnormality.

[A case of polyglandular autoimmune syndrome (PGA) type 1 complicated with slowly progressive IDDM]

A case of an 18-year-old female with polyglandular autoimmune syndrome (PGA) type 1 complicated by slowly progressive IDDM was described. She had epilepsy at the age of 5, and mucocutaneous candidiasis and hypoparathyroidism at 7 years. At the age of 18, the patient noticed thirst and body weight loss. On admission, she had uneven teeth and chronic mucocutaneous candidiasis. Plasma blood glucose was 312 mg/dl without ketosis, hemoglobin Alc 9.1%, serum calcium 3.5 mEq/l, serum phosphorus 6.0 mg/dl. A CT scan of her brain revealed calcification in the bilateral basal ganglia. Serum intact PTH was less than 10 pg/ml. Ellsworth-Howard's test showed hyperresponsiveness in the secretion of urinary phosphorus and cyclic-AMP. Other endocrinological studies showed no abnormality except for mild hyporesponsiveness in the secretion of urinary C-peptide (39.6 mu g/day). After admission, she was initially treated with diet alone with positive islet cell antibody (ICA). Three months later she was treated with low dose insulin, and ICA became negative. Then 5 months later it became positive again. Sixteen months later she had IDDM with positive ICA and without the secretion of urinary C-peptide. On the basis of these results, we diagnosed this case as PGA type 1 with the manifestations of hypoparathyroidism, chronic mucocutaneous candidiasis and slowly progressive IDDM. This is the second case report in Japan about PGA type 1. Furthermore, this case demonstrates for the first time in Japan that slowly progressive IDDM is complicated by PGA type 1. The patient had this HLA typing: A 24(9), BW52(5), BW60(40), CW3, DR2, DRW12, DQW7. More investigation is necessary to clarify the mechanism of PGA type 1.