In vivo and in vitro evidence for the production of inhibin-like immunoreactivity in human adrenocortical adenomas and normal adrenal glands: relatively high secretion from adenomas manifesting Cushing's syndrome

To clarify whether adrenal gland secretes inhibin in vivo in physiological or pathological conditions, we measured the levels of inhibin-like immunoreactivity (inhibin-LI) in adrenal veins (A-vein) and compared them with those in inferior vena cava (IVC) using blood samples obtained at catheterization of adrenal vein in the patients with adrenal adenoma manifesting Cushing's syndrome (Cs), aldosterone-producing adenoma, clinically non-functioning adenoma and normal adrenal gland. The tumor sides of A-veins in the patients with adenomas and also both sides of A-veins in subjects with normal adrenal glands showed significantly higher contents of inhibin-LI than their IVC. When the inhibin-LI secretion rate from adrenal gland was estimated by the difference between the levels of A-vein (tumor side) and IVC, Cs adenomas showed the highest secretion rate. Similarly, the tissue inhibin-LI content and the basal secretion rate of inhibit-LI from primary cultured cells were the highest in Cs adenomas. These findings indicated that normal adrenal glands and adrenocortical adenomas produced and secreted inhibin-LI into the general circulation in vivo and Cs adenomas have relatively high capacity for secreting inhibin-LI, and the present study provided the first in vivo evidence for adrenal inhibin-LI production in pathological conditions.

Long-term results of valve replacement with the St. Jude Medical valve

Between 1980 and 1992, 908 patients underwent single aortic (n = 178), single mitral (n = 577), or double aortic and mitral (n = 153) valve replacement with the St. Jude Medical valve at our hospital. There were 392 male patients and 516 female patients whose ages ranged from 1.2 to 74 years (mean, 52 years). The early mortality rate was 5.0% (45 patients). A 94% complete follow-up was accomplished for 863 patients who were discharged from the hospital (4682.3 patient-years). Sixty-nine of these patients died, for a late mortality rate of 8.0%. Fifty-two patients, including four patients (0.3%/100 patient-years) had anticoagulant-related hemorrhage, 4(0.1%/100 patient-years) had prosthetic valve endocarditis, 11 (0.2%/100 patient-years) had nonstructural valve dysfunction, and 16 (0.3%/100 patient-years) underwent reoperation. There were no structural valve failures in this series. The total number of valve-related deaths was 22. Of those patients who survived, 98% were in New York Heart Association functional class I or II at the date of the last follow-up. The probabilities of freedom from thromboembolism and anticoagulant-related hemorrhage at 10 years were 94% +/- 2% and 97% +/- 2% in aortic valve replacement, 89% +/- 2% and 98% +/- 4% in mitral valve replacement, and 89% +/- 6% and 92% +/- 6% in double valve replacement, respectively. Significant hemolysis related to the St. Jude Medical valve occurred in 8 of the 577 patients who received mitral valve replacement in our early experience, and modifying the valve orientation appeared to play an important role in reducing hemolysis. The event-free rate, including all complications and late deaths, at 10 years was 75% +/- 7%, 74% +/- 3%, and 81% +/- 6% in aortic valve replacement, mitral valve replacement, and double valve replacement, respectively. On the basis of these results, the St. Jude Medical valve seems to be an excellent mechanical valve in terms of durability and low thrombogenicity and remains our prosthetic valve of choice when valve replacement with a mechanical valve is indicated.

[Analyses of PCNA and AgNOR on advanced colorectal cancer as predictive indicators of the prognosis]

As part of a search for predictive indicators of the prognosis of advanced colon cancers, the significance of PCNA and AgNORs in terms of grading of biological malignancy was investigated. In 47 selected cases, which had been sufficiently followed up for the present study, PCNA labeling indices (PCNA LI) were 20.96 +/- 8.87 and 54.78 +/- 11.35 in normal colonic mucosa and colon cancer, respectively. With survival durations of more or less than 5 years, the PCNA LI values were 57.27 +/- 9.56 and 48.27 +/- 13.37, thus, suggesting a decrease with poor prognosis. PCNA LI decreased in proportion to the depth of cancer invasion and the progression of stage. In all of these cases statistically significant differences were apparent, whereas other histopathologic factors did not demonstrate any correlation. Numbers of AgNORs were 1.31 +/- 0.10 and 2.43 +/- 0.39 in normal tissues and cancers, the differences being statistically significant. However, no correlation with prognosis or histopathologic factors was noted for this parameter. In conclusion, our data suggest that PCNA LI might be an important predictive indicator of prognosis in advanced colon cancer. In contrast, AgNORs are of no assistance with this problem, although use of both or combination might facilitate differentiation between benign and malignant lesions.

Establishment and characterization of pthrp-producing human pancreatic-cancer cell-line

Human pancreatic ductal cell carcinoma cell line, which can secrete parathyroid hormone-related peptide (PTHrP), designated as KP 4, and its daughter cell lines with different PTHrP-secreting activities, termed KP 4-1 and KP 4-2, have been established in tissue culture. KP 4 cells were able to form tumors in nude mice. The absolute production rate of PTHrP in KP 4-1 was 5 to 10 times higher than that in KP 4-2. Similarly, the level of PTHrP mRNA in KP 4-1 was significantly higher than that in KP 4-2. KP 4-2 cells exhibited more rapid growth than KP 4 and KP 4-1 in vitro. Our established cell lines should provide a useful system to study the regulation of PTHrP production and its pathophysiological roles.

Mammalian cell gene mutation assays working group report

As part of the International Workshop on Standardization of Genotoxicity Test Procedures, in Melbourne, 27-28 February 1993, various international guidelines were examined with respect to protocol issues in the area of mammalian cell gene mutation assays. The working group on mammalian cell gene mutation assays discussed a wide range of protocol issues related to study design; in most cases the recommendations are reasonably consistent with existing guidelines. Agreement was reached on several issues as follows. The upper limit of concentration for testing non-toxic substances should be 10 mM or 5 mg/ml, whichever is lower. For testing toxic substances the criteria of an acceptable upper limit of concentration should yield 10-20% survival. Any of several established mammalian cell mutation assays (L5178Y TK+/-, CHO/HPRT, AS52/XPRT, V79/HPRT) can be used to evaluate mutagenesis in mammalian cells; the ouabain (Na/K-ATPase) system is not an acceptable mutation assay for routine evaluation of mutagenesis in mammalian cells. Ability to recover small colonies must be convincingly demonstrated when using the L5178Y TK+/- mouse lymphoma assay. In the mouse lymphoma assay (L5178Y TK+/-), colonies in positive controls and at least two (if available) representative positive doses of the test compound should be sized if a positive response is seen; in the event of a negative response due to the test compound, colony sizing of the positive control is necessary to validate the conduct of the assay. Testing both in the presence and absence of S9 metabolic activation is necessary. It was not possible to come to a firm conclusion about the length of treatment. There was a general agreement that extended treatment times (> 2 cell cycles) often bear more disadvantages than advantages and should only be used with adequate justification. It is not necessary to repeat clear positive or clear negative tests when the assay has been adequately performed; this recommendation differs significantly from the UK guidelines. If treatment groups are not replicated, the numbers of doses tested should be increased; this recommendation differs significantly from the UK guidelines. Each laboratory should establish a historical database for the performance of a given assay in that laboratory.

Alternative cell fate choice induced by low-level expression of a regulator of protein phosphatase 2A in the Drosophila peripheral nervous system

The Drosophila gene twins encodes the regulatory B subunit of type 2A protein phosphatase. Here we report that its partial loss-of-function mutations caused abnormal morphogenesis in the adult peripheral nervous system. In wild-type flies, the mechanoreceptor, one major class of sensory organs, is composed of four specialized cells (one neuron and three accessory cells) that are derived from a single precursor cell. The hypomorphic twins mutations did not block division of this precursor, but most likely altered cell fate in this lineage to produce only accessory cells that form sensory structures. Stepwise reductions of twins protein enhanced this transformation. In these mutants, another regulatory subunit, A, and the catalytic subunit, C, of the phosphatase were expressed at normal levels. Therefore, the modulation of the phosphatase activity by the B subunit appears to be crucial for specification of neural cell identity.

Structure of the genomic DNA encoding cucumber ascorbate oxidase and its expression in transgenic plants

Genomic DNA (Aso1) encoding the ascorbate oxidase (ASO) of cucumber (Cucumis sativas) was cloned and sequenced. From a comparison of the sequences of Aso1 and its cDNA [Ohkawa et al. Proc. Natl. Acad. Sci. USA 86 (1989) 1239-1243], it was concluded that Aso1 consisted of four exons and three introns. In the 5'-flanking region, sequence motif resembling a TATA box and a CAAT box, were found 124 and 218 bp upstream, respectively, from the start codon. Sites of initiation of transcription, determined by primer extension, were the A and G residues located 90 and 93 bp, respectively, upstream from the initiation codon. ASO was abundant in cucumber fruits and stems. The 5'-flanking region, placed upstream of the structural gene of β-glucuronidase (GUS), expressed the GUS activity in cucumber plants in a transient expression assay after introduction of DNA with a particle gun. High-level GUS expression was found in stems of transgenic tobacco plants harboring Aso1 promoter-GUS chimeric gene.

Reserved Sertoli cell function in the hypogonadic male patients with myotonic dystrophy

To clarify the Sertoli cell and Leydig cell function in hypogonadic male patients with myotonic dystrophy (DM), serum concentrations of inhibin, total testosterone (TT), follicle-stimulating hormone (FSH) and luteinizing hormone (LH) were measured by radioimmunoassay in 6 male DM patients (41 to 56 years old, 47.7 +/- 5.05 years old) and compared with those in normal adult men. In 116 healthy men aged from 24 to 92 years, serum inhibin and TT levels decreased and serum FSH and LH concentrations increased with advancing age. There was an inverse correlation between serum inhibin and FSH. These results support the concept of negative feedback regulation system of FSH secretion by inhibin. Male DM patients showed significantly lower serum TT and higher concentrations of FSH and LH, compared with the age-matched 39 normal adult men (49-59 years old, 48.2 +/- 6.14 years old). However, there was no significant difference in serum inhibin levels between the patients and normal counterparts. These results indicate that the Sertoli cell function is reserved in male DM patient, although the Leydig cell function is impaired. It is also suggested that in these patients a negative feedback control system between inhibin and FSH may be disordered to some extent.

Characterization of effector cells against B16 melanoma in mice inoculated with allogeneic spleen cells

Inbred C57BL/6 (B6) mice which had received an inoculation of allogeneic spleen cells showed remarkable antitumor activity against syngeneic tumor challenge with B16 melanoma cells 3 days after the allogeneic cell inoculation. This antitumor activity was not specific to the inoculated alloantigen, since the challenging B16 cells are syngeneic to B6 mice and since it was induced by BALB/c spleen cells as well as C3H/He spleen cells. The antitumor activity was sensitive to an in vivo treatment with anti-asialo GM1 (AGM1) antiserum or anti-Thy.1 monoclonal antibody (mAb) just before the tumor challenge and was resistant to an in vivo treatment with anti-CD8 (Ly.2) mAb. These results suggest that AGM1+Thy.1+CD8- activated natural killer (NK) cells were generated by alloantigen inoculation and took an important part in the antitumor effect of the alloantigen inoculation.

Sertoli cell function declines earlier than Leydig cell function in aging Japanese men

In order to evaluate the age-related changes in Leydig cell and Sertoli cell function, we measured serum levels of total testosterone (TT), free testosterone (FT), inhibin, LH and FSH in 116 healthy Japanese men, aged 24-92 years. Serum TT remained constant up to the age of 80 years and decreased thereafter. Serum FT declined linearly with aging and was significantly lower in men in their forties than in younger men (24-39 years old). Serum inhibin levels also declined with aging, with serum concentrations significantly lower in men older than 40 and markedly lower in men over 80 years old. LH and FSH were elevated in men over 60 and 40 years old, respectively. We also examined relationships between gonadotropins and gonadal hormones in these men divided into three age groups, young (24-39 years old), middle aged (40-59 years old) and aged (60-92 years old) men. Although there was a significant inverse correlation between LH and TT or FT for the entire population, subset analysis demonstrated that this inverse correlation was confined to men over 60 years old. In fact, in young men, TT and FT were positively correlated with LH. Overall, there was also an inverse correlation between FSH and inhibin. In subset analysis this relationship was present in both middle aged and aged men. These findings suggest that in Japanese men testicular endocrine functions decline after the fourth decade of life, and that Sertoli cell function declines earlier than Leydig cell function.

Megabase-scale analysis of the origin of N-myc amplicons in human neuroblastomas

In order to elucidate the initiation of the N-myc gene amplification, we have analyzed the original structures of the N-myc amplicons among 38 human neuroblastomas. Nineteen DNAs isolated from the N-myc amplicons recognized a continuous stretch totally encompassing a 5.5 megabase region spanning the normal N-myc gene. The co-amplification profiles with these DNAs showed that two of them, which mapped into a 300 kb region flanking the N-myc gene, were commonly amplified in most specimens, while others were differentially amplified among various subsets. These profiles enabled us to divide the N-myc amplicons into several groups and outline their original domains as a continuous stretches, pointing to the existence of 'consensus sites' for the ends of the initial domains in the original region. In one cell line, the domain was found to be several times larger than that of the derivative amplicon; and the rearranged sites identified within the amplicons, which showed no site specificity, were consistent with those deduced from the domain structure. These results lead to a model in which N-myc gene amplification is initiated at some consensus sites by a preferential mechanism and followed by a random loss of the domain structures during subsequent stages.

Tricuspid valve replacement with the St. Jude Medical valve

A study was conducted on 20 patients who underwent tricuspid valve replacement (TVR) with the St. Jude Medical (SJM) valve. Isolated TVR was performed on 9 patients, and additional mitral, or mitral and aortic valve replacements were performed on 11 patients. Four patients (20%) died in the early postoperative period, but there were no deaths related to the SJM valve in the tricuspid position. The mean follow-up period of the 16 survivors was 74.4 months, and there have been no deaths during the follow-up period. The postoperative actuarial survival rate was 80%, 10 years after surgery. Three patients, representing 0.25%/patient-months, developed valve thrombosis, the valve thrombosis-free rate being 72.8%, 10 years after surgery, while entrapment of a leaflet by endothelial pannus was found in one patient, representing 0.08%/patient-months. Thus, the incidence of all prosthetic valve-related complications was 0.34%/patient-months, and the postoperative complication-free rate was 65.3%, 10 years after surgery. The medium-term follow-up study of TVR with the SJM valve revealed no prosthetic valve-related deaths and a relatively low incidence of prosthetic valve-related complications. However, as with other mechanical valves, valve thrombosis was a major risk posed by the SJM valve in the tricuspid position.

Obstruction of the St. Jude Medical valve--diagnostic and therapeutic values of cineradiography

Between 1984, and 1992, we observed 8 patients with an obstructed St. Jude Medical (SJM) valve. Of these, 1 had an obstructed SJM valve in the aortic position, 3 in the mitral position, and 4 in the tricuspid position. Diagnosis of obstruction of the SJM valve was made by cineradiography combined with echocardiography in all 8 patients. Restriction or absence of movement of the leaflet of the SJM valve was observed by cineradiography in all of the 8 patients. Normal range of leaflet mobility of the SJM valve was measured by conventional cineradiography in 70 patients with a normal SJM valve, and the results were compared with the leaflet mobility obtained from the 8 patients with an obstructed SJM valve. In this study, leaflet function in the obstructed SJM valve was strikingly abnormal, with both opening and closing angles, and leaflet motion clearly outside the normal range. Of the 8 patients, 4 underwent urgent prosthetic valve replacements after cineradiography and echocardiography were carried out. Thrombolysis using urokinase was performed in 4 patients, and this treatment was successful in 1 patient. Efficacy of thrombolytic therapy was evaluated by repeat cineradiography. Three of the 4 patients who received thrombolysis showed no significant improvement of leaflet mobility after at least 72 hours of thrombolytic therapy, and finally required surgical correction for the obstructed SJM valve. We believe that cineradiography combined with echocardiography is the optimal method for the diagnosis of obstruction of the SJM valve, and to follow the effect of thrombolytic therapy on prosthetic valve function.(ABSTRACT TRUNCATED AT 250 WORDS)

Treatment of isolated growth hormone deficiency type IA due to GH-I gene deletion with recombinant human insulin-like growth factor I

Biosynthetic insulin-like growth factor I (IGF-I) was administered subcutaneously twice a day for one year to a patient with isolated growth hormone deficiency (IGHD) type IA with high titres of anti-GH antibody (up to 1:1,000,000). During IGF-I therapy he showed good linear growth without any side effects, such as hypoglycemia and anti-IGF-I antibody formation. Administration of IGF-I to IGHD type IA with poor response to GH therapy appears to have a beneficial effect on growth.

Persistent synchronous periodic discharges caused by anoxic encephalopathy due to cardiopulmonary arrest

We report a patient with vegetative state induced by anoxic encephalopathy due to cardiopulmonary arrest who showed synchronous periodic discharges for a prolonged period. The patient was a 47-year-old man admitted to our hospital for depression, who suddenly developed cardiopulmonary arrest of unknown etiology, and entered chronic vegetative state as a result of anoxic encephalopathy. Electroencephalography (EEG) revealed that synchronous periodic discharges were present for up to 5 months. The wave pattern, periodicity and duration of appearance of synchronous periodic discharges were similar to those of synchronous periodic discharges in Creutzfeldt-Jakob disease (CJD). The periodicity of synchronous periodic discharges was gradually prolonged, with the course again similar to the discharges in CJD. The mechanism of occurrence is considered to be similar to that of synchronous periodic discharges in CJD.

Structural organization of MYCN amplicons of neuroblastoma tumors, xenografts, and cell lines characterized by the sequences encompassing the MYCN amplicons in a human neuroblastoma cell line

We characterized differences in the structural organization of the MYCN amplicons of a number of neuroblastomas by analyzing 8 contigs spanning 330 kb cloned from the MYCN amplicon of a neuroblastoma cell line. Some regions were amplified in almost all specimens, the conserved regions (CRs), and others were differentially amplified in some subsets, the non-conserved regions (NCRs). CRs constituted only 20% of the 330 kb region, with the remainder being NCRs. The regions that inevitably co-segregate with the MYCN gene make up the core, whereas flanking regions are retained at random. If a histogram of the frequency with which the amplified NCR sequences from one specimen match those of the cell line MC-NB-I shows a random distribution, the NCRs would co-segregate with MYCN as a result of random events. However, both the tumors and cell lines/xenografts showed a distribution with two distinct peaks; one from a group containing a small number of sequences with a fairly high degree of homology to the NCRs of MC-NB-I, and the other from a group containing a large number of sequences with little homology. These results indicate that the flanking segments are preferentially co-segregated with MYCN by a non-random mechanism.

Antipromoting effects of 5-lipoxygenase inhibitors, 3-nitro-2,4,6- trihydroxybenzamide derivatives, on TPA-promoted transformation in BALB 3T3 cells

In order to discover the role in the promotion process of 5-lipoxygenase (5-LO), a key enzyme in the arachidonate cascade, the antipromoting effects of the 5-LO inhibiting 3-nitro-2,4,6-trihydroxybenzamide (NTB) derivatives were studied in a two-stage transformation assay system using BALB 3T3 cells. All compounds inhibited TPA-promoted transformation in a dose-dependent manner. Most of them achieved a 70-80% inhibition. Good correlations were observed between the inhibition of TPA-promoted transformation and that of 5-LO. These results indicate that 5-LO plays an important role in the promotion stage of the transformation of BALB 3T3 cells.

Growth hormone therapy in achondroplasia

The status of growth hormone (GH) secretion together with the effect of GH therapy was studied in six children with achondroplasia. One patient had impaired GH secretion, which may, in part, be due to obesity. The pre-GH-treatment height velocity was 3.8 +/- 0.7 cm/year, but this increased to 6.0 +/- 1.0 cm/year in the first year of treatment and to 4.4 +/- 0.6 cm/year in the second year. One patient who underwent GH therapy for 4 years showed good response in height velocity. A considerable variation was observed in response to GH therapy within the treated cases.

High expression of cytochrome b5 in adrenocortical adenomas from patients with Cushing's syndrome associated with high secretion of adrenal androgens

The mechanism of dissociated secretion between adrenal androgens and cortisol observed in several clinical situations remains unclear. We investigated whether the electron transfer systems NADPH-cytochrome P450 reductase and cytochrome b5, both of which had been shown to increase 17,20-lyase activity in vitro, were involved in the reaction selectivity between 17 alpha-hydroxylase and 17,20-lyase in adrenocortical adenomas obtained from eight patients with Cushing's syndrome producing different concentrations of adrenal androgen. In vitro enzyme assay using microsomal fraction of adenoma indicated that all adenomas from seven patients showed almost the same degree of 17 alpha-hydroxylase and 3 beta-hydroxysteroid dehydrogenase (3 beta HSD) activities. However, the 17,20-lyase activities of two adenomas producing high concentrations of adrenal androgens were 3-fold greater than those of other five adenomas producing low concentrations of adrenal androgens. The mRNA concentrations of cytochrome P45017 alpha and 3 beta HSD were approximately the same in all adenomas, whereas those of cytochrome b5 in two adenomas possessing high 17,20-lyase activities were greater than those in other adenomas. The increased levels of cytochrome b5 in the two adenomas were further confirmed at the protein level using Western blot analysis of the microsomal fraction. No significant expression of NADPH-cytochrome P450 reductase was detected in any of the adenomas by Northern blot analysis. These results suggest that the difference in the concentration of cytochrome b5 in adrenal adenomas from patients with Cushing's syndrome may partially account for the difference in the amount of adrenal androgens produced by the tumors.