A retrospective analysis of the long-term effect of splenectomy on late infections, graft-versus-host disease, relapse, and survival after allogeneic marrow transplantation for chronic myelogenous leukemia

The present study was performed as a retrospective analysis of the role of pretransplant splenectomy to determine the incidence of late bacterial infections, acute and chronic graft-versus-host disease (GVHD), relapse, and survival among 358 patients receiving HLA-identical marrow grafts for chronic myelogenous leukemia. Sixty-eight (19%) of the 358 patients had undergone splenectomy before transplantation. There was a trend towards more grade II-IV acute GVHD among splenectomized patients, but this was not significant in the multivariate analysis. The incidence of chronic GVHD was similar for splenectomized and nonsplenectomized patients. Late infectious complications did not significantly differ between splenectomized and control patients (rates per patient year were 0.16 and 0.14, respectively). The overall risk of leukemic relapse was significantly increased for splenectomized patients (56% v 32% for controls, P = .001) and control patients with splenomegaly (P < .0001). Splenectomy and splenomegaly remained significant and independent hazards for relapse in the multivariate analysis (hazard ratio [HR], 1.82, P = .029; and HR, 1.49, P = .002; respectively). Relapse was also increased in patients with advanced disease (HR, 2.95; P = .0001), in patients with T-cell-depleted marrow (HR, 4.51; P = .0001), and in the female donor and male recipient combination (HR, 1.74; P = .044). Patients with splenectomy had an increased overall mortality (HR, 1.18), but this was not statistically significant in the multivariate analysis. In summary, our study showed no significant influence of splenectomy on late posttransplant infections, acute or chronic GVHD, or overall survival. There was no evidence that splenectomy decreased recurrence of chronic myelogenous leukemia.

Microsatellite instability in multiple gastric cancers

To better elucidate the role of genetic instability in the development of gastric cancer, microsatellite alterations were examined in a total of 30 gastric cancers that developed in 14 Japanese patients with multiple gastric cancers, which are considered to have possibly occurred under the same genetic background and in the same microenvironment of the stomach. Microsatellite instability (MSI) in multiple gastric cancers was recognized in 11 out of 14 cases (78.5%) and in 16 out of 30 cancers (53.3%). Eight out of 11 cases showing MSI exhibited a heterogeneity of microsatellite alterations. The incidence of microsatellite instability in the multiple gastric cancers cases was significantly higher than that in the solitary gastric cancer cases reported previously (20.8%: 5 out of 24 cases). These results suggested that (1) genetic instability plays a more important role in the development of multiple gastric cancers than in that of solitary gastric cancer and (2) the heterogeneity of MSI in multiple gastric cancers may not be a rare event, although the significance of the heterogeneity could not be clarified.

Microsatellite instability in Japanese esophageal carcinoma

Recent studies have shown that microsatellite instability (MSI) may play an important role in the development of various types of cancer. However, there have been only 2 reports describing MSI in esophageal carcinoma and the clinicopathologic significance of MSI in this malignancy has not yet been clarified. To better elucidate the role of genetic instability in the development of esophageal carcinoma, we investigated the presence of MSI in 32 cases of esophageal cancer using paired samples of fresh frozen tumor and normal tissue by a method based on the polymerase chain reaction. MSI was defined as occurring in tumors which showed altered banding patterns at one or more microsatellite loci. The incidence of MSI in esophageal carcinoma was 6 out of 32 patients. MSI was observed more frequently in cases with small-cell carcinoma (2 out of 2) than in cases with squamous-cell carcinoma (4 out of 29). No cases with adenocarcinoma or Barrett's metaplasia were included in our series. No significant correlations between MSI and other clinicopathologic parameters were observed. The present study suggests that (1) some Japanese esophageal carcinomas certainly correlate with DNA replication error, and (2) MSI may be more frequent in small-cell carcinoma of the esophagus than in squamous-cell carcinoma of the esophagus.

Activation of the thyrotropin-releasing hormone (TRH) receptor by a direct precursor of TRH, TRH-Gly

We studied the mechanism by which thyrotropin-releasing hormone (TRH)-Gly stimulated prolactin and thyrotropin (TSH) secretion in pituitary, using a pituitary mammotropic cell line, GH3 cells, and a cell line stably expressing a human TRH receptor (TRH-R). In GH3 cells expressing endogenous TRH-R, an addition of TRH-Gly evoked an immediate rise of intracellular calcium concentration, indicating that TRH-Gly reacted directly without converting from TRH-Gly to TRH. In order to determine whether this reaction might occur through TRH-R, we established a cell line stably expressing a human TRH-R, by transfecting a human TRH-R cDNA into Chinese hamster ovary cells (CHO cells). In this cell line, 10 nM TRH elevated intracellular calcium significantly; the Kd for MeTRH was 1.7 nM. One micromolar and 100 nM TRH-Gly also elevated intracellular concentration of calcium significantly, but not in CHO cells which were not transfected with the TRH-R cDNA. Competition studies further revealed that TRH-Gly displaced MeTRH binding (IC50, 12 microM). These data indicate that at high concentration, TRH-Gly interacts directly with TRH-R to activate signal transduction pathway, and that release of prolactin and TSH induced by TRH-Gly in vitro may be due, at least in part, to the direct effect of TRH-Gly on the TRH-R.

Multiple tumor-suppressor-1 gene and esophageal-carcinoma

The multiple tumor suppressor 1 (MTS1) gene is homozygously deleted frequently in cell lines derived from a wide variety of tumors. We investigated the deletion of the MTS1 gene in esophageal cancer cell lines and primary esophageal squamous carcinomas using the polymerase chain reaction. Sixteen and 15 of 23 esophageal cancer cell lines showed homozygous deletion of MTS1 exon 1 and exon 2, respectively, while none of 21 primary esophageal carcinomas showed the deletion. An analysis of MTS1 gene mutations was carried out by direct DNA sequencing in 8 cell lines and 21 primary carcinomas showing no homozygous deletion. In contrast to previous reports of esophageal carcinoma, there were no mutations recognized in the region sequenced. Our study suggests that the inactivation of the MTS 1 gene may play an important role in esophageal carcinoma cell lines but may be less important in primary carcinomas of the human esophagus.

Increase in serum interleukin-6, plasma ACTH and serum cortisol levels after systemic interferon-alpha administration

Systemic administration of human interferon-alpha stimulates the pituitary-adrenal axis in men, but the exact mechanism still remains to be established. The present study was undertaken to examine the hypothesis that interferon-alpha may alter the circulating concentrations of the cytokines which involve the activation of the pituitary-adrenal axis. Eleven patients with chronically active hepatitis C were treated with human lymphoblastoid interferon-alpha (IFN: 6 x 10(6) IU/day) and changes in plasma adrenocorticotropin (ACTH), serum cortisol and cytokine concentrations were observed on both the first and second days of the treatment. Subcutaneous administration of IFN significantly increased plasma ACTH and serum cortisol concentrations by 3 h after the injection. Serum interleukin-6 (IL-6) increased with the increase in circulating ACTH and cortisol. There was a significant correlation between serum cortisol and IL-6 concentrations at 3 h. In contrast, an increase in serum interleukin-1 beta was only observed in one case. On the second day of IFN treatment, simultaneous administration of 25 mg diclofenac sodium eliminated the IFN effects on circulating ACTH, cortisol and IL-6 concentrations. The present studies demonstrated that circulating IL-6 increases after systemic IFN administration, resulting in activation of the pituitary-adrenal axis.

Effect of continuous infusion of lysine via different routes and hepatic vagotomy on dietary choice in rats

The effect of continuous L-lysine (Lys) infusion on dietary choice between Lys deficient and protein-free diets in Sprague-Dawley rats was studied to determine the sensing site of Lys deficiency. After daily intake of each diet became constant, Lys was continuously infused for 11 days via intraperitoneal (IP), intragastric (IG) or intracerebroventricular (ICV) route, with an osmotic pump. Daily intake of each diet was measured. Intake of the Lys deficient diet compared with protein-free diet in either IP or IG Lys-infused group increased significantly (p < 0.001) vs. the intake in the baseline period. The selection of the Lys deficient diet was quite comparable between IP and IG groups. But the intake of the ICV group was unchanged. Hepatic vagotomy during IP infusion transiently delayed selection of the Lys deficient diet. These results imply the roles of postabsorptive mechanisms in sensing an amino acid deficiency, and possible involvement of the hepatic branch of the vagus in the sensing. However, sensing in the brain or indeed in the intestine was not excluded.

Complete response of transverse colon carcinoma to S1, a new chemotherapy agent: report of a case

A complete response to a new chemotherapeutic agent, S1, was achieved in a 64-year-old Japanese man with advanced transverse colon cancer. S1 is a combination of the agents tegafur, 5-chloro-2,4-dihydroxypyridine, and oxonic acid. Because the patient was considered to be a high operative risk due to his poor general condition, S1 was administered at 100 mg/day for 5 days/week over 12 weeks. However, as the serum carcinoembryonic antigen level continued to gradually increase, partial resection of the transverse colon was finally performed. Histopathological study of the resected specimen showed mucin pools in the colon wall with no residual viable cancer cells. No perioperative complications were recognized and the patient is now leading a normal life 6 months after his operation without any signs of recurrence.

[A case of large cell carcinoma of the lung arising from the inner surface of a pulmonary bulla and complicated by hematoma]

A 64-year-old man with a history of smoking was admitted to our hospital, because he was noted to have a solitary mass lesion at the apex of the right lung on a chest roentgenogram. Eight months before admission, he had come to our hospital because of hemoptysis. At that time, however, no abnormal shadow was seen on his chest roentgemogram, except for multiple bullae at both apexes. Based on chest CT findings on admission, the tumor appeared to be a hematoma growing inside the bulla. The resected tumor was found to contain a large amount of coagulated blood in the bulla. Histopathological examination of the bulla revealed a proliferation of large atypical cells from the inner surface of the bulla toward the inner space. Thus, the diagnosis was large cell carcinoma within the wall of the pulmonary bulla, the inside of which was filled with hematoma. We believe that the hematoma in the bulla allowed us to make an early diagnosis, and thus to succeed in curing the patient.

[Clinical analysis of elderly patients with malignant lymphoma]

An epidemiological study on 173 consecutive elderly malignant lymphoma patients age 65 years or over was performed and the clinical outcome of chemotherapy is reported. Of there, 131 patients (75.7%) had non-Hodgkin's lymphoma (NHL) and 21 patients had Hodgkin's disease (HD). As for clinical staging, 58.9% of patients were in stage 3 or 4. The initial sites were nodal in 61.8% of the patients the most common sites of involvement in superficial lymph nodes being cervical, inguinal and axillar. The most frequent site of extranodal involvement was the gastrointestinal tract. The cases were treated with CHOP/COPP, BACOP or COP-BLAM combination chemotherapy. The clinical efficacy of these modalities was similar, with complete remission rates being about 50%. However, the total response rate (CR+partial remission) by the COP-BLAM regimen were 88.1%. The median survival time of cases achieving CR, was longer than 47 months. The most frequent cause of death was infection, especially pneumonia and septicemia. Many elderly ML patients were found and diagnosed when the disease developed to an advanced stage. Therefore it is necessary to make efforts to find early ML patients by screening apparently healthy elderly people. Improvement of the complete remission rate should be obtained if vigorous and intensive chemotherapy is carried out with careful supportive therapy concerning the general condition and complications in patients.

Transcriptional down-regulation by epidermal growth factor of TRH receptor mRNA in rat pituitary cells

To gain insight into the mechanism underlying the epidermal growth factor (EGF)-induced changes in responsiveness to TRH and in the numbers of TRH receptors (TRH-Rs) in the pituitary, we investigated the transcriptional regulation by EGF of the TRH-R gene in GH4C1 cells. Northern blot analyses and binding studies revealed that EGF reduced both TRH binding and TRH-R mRNA levels in a dose- and time-dependent manner, while no significant changes were observed in beta-actin mRNA levels. Addition of actinomycin D caused an acute increase in the basal TRH-R mRNA level, and the rate of decrease of the TRH-R mRNA was identical in control and EGF-treated groups, suggesting that the stability of the TRH-R mRNA was not significantly affected in EGF-treated cells. Incubation with cycloheximide also induced an increase in the basal TRH-R mRNA level and completely reversed the EGF-induced reduction of TRH-R mRNA levels. Furthermore, a nuclear run-on assay demonstrated that the rate of transcription of the TRH-R gene was significantly inhibited in cells treated with EGF. We conclude that (1) EGF decreases the expression of the TRH-R mRNA largely by reducing its rate of transcription, and this action requires the synthesis of new proteins, and (2) inhibitors of protein and RNA synthesis cause a significant increase in the basal TRH-R mRNA level, suggesting that there may be a short-lived protein suppressing the TRH-R mRNA level in the pituitary.

Expression of Fas antigen and Bcl-2 protein in hepatocellular carcinoma

Fas antigen (ag) is a cell surface protein known to trigger apoptosis in a variety of cells upon specific antibody binding. On the other hand, Bcl-2 protein, an oncogene product located at the mitochondrial inner surface, prolongs cell survival by blocking apoptosis. In this study we examined the expression of Fas ag and bcl-2 protein in 17 cases of hepatocellular carcinoma (HCC) to determine their role on HCC. By flow cytometric analysis, mean (SD) value of the expression of Fas ag on hepatocytes derived from normal liver, diseased liver (chronic hepatitis or liver cirrhosis) and HCC was 5.8 (4.7)%, 10.3 (6.9)%, and 24.0 (18.2)%, respectively. Fas ag expression on hepatoma cells was significantly greater than normal and diseased liver cells. The expression of Bcl-2 protein in normal liver, diseased liver and HCC was 4.3 (8.5)%, 0.8 (2.5)% and 2.1 (3.4)%, respectively, and the difference was not significant. These results suggest that induction of apoptosis may be a possible therapy against HCC.

Esophagocardioplasty for achalasia in closure of a complicated esophagobronchial fistula

We report a rare case of benign esophagobronchial fistula associated with achalasia. The fistula healed spontaneously after esophagocardioplasty with a gastric patch, suggesting the utility of this procedure.

Improvements in diagnosis have changed the incidence of histological types in advanced gastric cancer

The data on 912 patients with early cancer and 1245 with advanced cancer who were seen between 1971 and 1990 were compared. The incidence of undifferentiated-type cancer increased significantly in patients with advanced gastric cancer, but not in patients with early gastric cancer. When the histological types were compared with regard to sex, age and location in patients with early gastric cancer the undifferentiated type was found to increase only in males, while in patients with advanced gastric cancer the undifferentiated type increased in both sexes as well as in younger patients and in both the upper and middle third of the stomach. These differences in the trends between early and advanced cancers are probably due to the different degrees of diagnostic accuracy for the early detection of histological types.

Detection of cancer micrometastases in lymph nodes by reverse transcriptase-polymerase chain reaction

There are few DNA-based studies that detect cancer micrometastases in lymph nodes. We have assayed for the specific detection of carcinoembryonic antigen (CEA)-expressing carcinoma cells in the lymph nodes of patients with gastrointestinal or breast carcinomas. A CEA-specific nested reverse transcriptase (RT)-PCR assay was optimized using limiting dilutions of a CEA-positive cancer cell line mixed with normal lymphocytes. The expression of CEA mRNA was studied in 100 carcinoma tissues, 75 normal mucosal tissues, and 15 lymph nodes from patients with cholelithiasis. Each of 117 lymph nodes from 13 patients with carcinoma was divided into two pieces: one was used for histological examination and the other for RT-PCR, and the results were compared. The sensitivity ratio was one CEA-expressing cancer cell detected in 1 x 10(5) normal lymphocytes. All carcinoma tissues and normal mucosal tissues expressed CEA mRNA, while no amplification was detected in any control lymph nodes. Thirty of 117 lymph nodes were histologically involved by carcinoma cells, and all of these yielded the expected product by RT-PCR. Of the remaining 87 histologically negative nodes, CEA mRNA was detected in 47 lymph nodes by RT-PCR. The positive rate increased from 26% by histological examination to 66% by RT-PCR. The assay by CEA-specific nested RT-PCR is not only sensitive but widely applicable for the detection of cancer micrometastases in lymph nodes. This method may lead to an earlier diagnosis and treatment of patients with subclinical lymph node metastasis.

Stimulation of insulin action and stabilization of cell membrane in 3T3-L1 cells by glycinin acidic subunit A1a

Glycinin acidic subunit A1a and its trypsinized product (A1a/Try) were found to potentiate insulin-mediated antilipolysis antagonized to isoproterenol in 3T3-L1 preadipocytes and adipocytes. A1a and A1a/Try protected 3T3-L1 preadipocytes from the cytotoxic action of trypan blue. Furthermore, the oxygen consumption in rat liver mitochondria that was accelerated during incubation, which implies an increase in the permeability of the inner membrane, was suppressed by the addition of A1a and A1a/Try. On the other hand, the chymotryptic product of A1a did not show such effects. These results suggest that specific amino acid alignment is required for the functions of A1a and that the insulin-stimulating action of A1a and A1a/Try is closely correlated with their stabilizing effect on cell membranes.

Metabolism of essential amino acids in growing rats at graded levels of soybean protein isolate

The metabolic fates of the carbon skeletons of essential amino acids were investigated in growing rats fed on diets containing graded percentages of protein calories (5, 10, 15, 20, 30, and 40 PC%) using soybean protein isolate at 4,100 kcal of metabolizable energy per kg of diet. The incorporation of 14C into the body protein 12 h after the intraperitoneal injection of labeled essential amino acids was more than 60% of the dose in the 5 to 10 PC% groups, but it began to decline gradually in the higher PC% groups. The expired 14CO2 production from labeled threonine, tryptophan, leucine, isoleucine, valine, phenylalanine, and lysine increased linearly with increasing levels of dietary soybean protein, but the rate of increase in the 14CO2 production was lower in the higher PC% groups. In comparison, the 14CO2 production from methionine, histidine, and arginine decreased in the 5 to 15 PC% groups, and it increased linearly in the higher PC% groups. The extent of 14CO2 production varied among the essential amino acids in each dietary group. These results indicate that the carbon skeletons of essential amino acids are mainly utilized for body protein synthesis, but significant amounts of their carbons are oxidized to expired carbon dioxide for energy production, and that the metabolic responses of these amino acids to dietary protein level change at around 20 PC%, where the growth rate reached its approximate maximum. The utilization of individual essential amino acids in rats fed on the soybean protein diets changed markedly as compared to those on purified whole egg protein diets, the results of which have been reported elsewhere.

Chromogranin positive cells in colorectal carcinoma and transitional mucosa

AIMS

Immunostaining of chromogranin identifies gastrointestinal mucosal endocrine cells. The detailed distribution and significance of chromogranin positive cells in colorectal carcinomas and in transitional mucosa remain unclear. The aim of this study was to clarify these aspects.

METHODS

The distribution of chromogranin positive cells was studied by immunohistochemical methods in normal epithelium remote from carcinoma, in transitional mucosa, and in carcinomas of the colorectum. In selected cases northern or western blot analyses were performed.

RESULTS

Chromogranin positive cells were seen in the lower third of the normal crypts and less frequently in transitional mucosa. Thirty five per cent (n = 38) of colorectal carcinomas showed immunohistochemically positive carcinoma cells in the tumour tissue. Northern and western blot analyses showed similar results. There was no difference in clinicopathological factors, including prognosis, between chromogranin positive cases of colorectal carcinoma (n = 38) and chromogranin negative cases (n = 70).

CONCLUSIONS

Neuroendocrine cell differentiation is controlled in transitional mucosa and the presence of chromogranin positive cells in carcinoma tissue does not influence the patient's prognosis.

Spontaneous sustained ventricular tachycardia in the Electrophysiologic Study Versus Electrocardiographic Monitoring (ESVEM) Trial

OBJECTIVES

We compared the QRS waveforms of the initial and subsequent complexes of spontaneous sustained monomorphic ventricular tachycardia and the rhythm induced at electrophysiologic study to test the theory that premature ventricular complexes "trigger" spontaneous ventricular tachycardia and that a stable substrate exists such that the spontaneous arrhythmia can be reproduced at electrophysiologic study.

BACKGROUND

Failure rates have been high in several recent studies in which prevention of ventricular tachyarrhythmias was guided by suppression of premature ventricular complexes or induced ventricular tachycardias.

METHODS

Digital waveform analysis was used to distinguish events of ventricular tachycardia initiated by configurationally distinct, possibly triggering, complexes (type 1) from events in which the initial QRS waveforms were identical to subsequent complexes, suggesting no requirement for premature ventricular beats (type 2).

RESULTS

Of 1,102 episodes of spontaneous ventricular tachycardia, 73 (6.6%) were type 1; 1,012 were type 2 (91.8%); and 17 (1.5%) were uncertain. Of 59 patients only 14 (24%) had only type 1 episodes (group 1), whereas 37 patients (63%) had predominantly type 2 events (group 2) (p < 0.0001). Sustained ventricular tachycardia was inducible in all group 1 patients, and in most (57%) the induced rhythm was similar to the spontaneous rhythm. Ventricular tachycardia could not be induced in 7 patients from group 2 (19%), and in 18 patients (49%) the induced and spontaneous rhythms were dissimilar. Recurrence of arrhythmia rates differed according to the guidance method in group 2.

CONCLUSIONS

Discrepancies between observed and predicted modes of initiation of ventricular tachycardia and between spontaneous and induced rhythms could result in inappropriate guidance and subsequent failure of antiarrhythmic treatment.

Nucleotide sequence analysis of two nuclear inclusion body and coat protein genes of a sweet potato feathery mottle virus severe strain (SPFMV-S) genomic RNA

Recombinant DNA molecules containing cDNA of a sweet potato feathery mottle virus severe strain (SPFMV-S) RNA genome were constructed and the partial nucleotide sequences were determined for three DNA inserts, which cover 4-2 kb from the 3'-terminus excluding the poly (A) tail. This region of the genome consists of an open reading frame of 1340 amino acids (a.a.) and a 3'-non-translated region of 224 nucleotides. The protein products expected were 6K2 (53 a.a.), NIa (435 a.a.), NIb (521 a.a.) and CP (315 a.a.). Among NIa, NIb and coat proteins, the NIb protein was found to be the most conserved (59-68%) when compared to the corresponding proteins of other distinct potyviruses.

[Changes of specific and non-specific immunological functions before and after transsphenoidal tumor excision--a case of Cushing disease]

The interrelationship between the hypothalamic-pituitary-adrenal axis and the immune system has been becoming clear. However, most research about this interrelationship has been performed by in vitro experiments and by using animal models. To know the effect of hypercortisolism on human immune systems in vivo, we report at 32-year-old man with typical Cushing disease whose specific and non-specific immunological functions were estimated before and after successful transsphenoidal surgery. We made a diagnosis of Cushing disease with dexamethasone suppression test, CRF stimulation test, venous sampling, and MRI scan. Before transsphenoidal surgery, both plasma ACTH (100pg/ml) and urinary free cortisol (567 micrograms/day) were higher than the normal range, and the parameters of specific (CD4/CD8 ratio, serum Ig A, PHA/Con-A induced T cell blast formation, and NK cell activity) and non-specific (neutrophil phagocytosis and bactericidal function) immunological functions were clearly impaired. However, at 6 weeks and 6 months after the tumor excision when hormonal abnormalities were changed to normal, every impaired immunological function was improved to the normal range. These data suggest that impaired specific and non-specific immunological functions were induced by hyercortisolism not only in vitro but also in vivo (a state of Cushing disease).

Nuclear DNA content and nucleolar organizer regions in colorectal cancer

The prognostic value of nuclear DNA content and argyrophilic nucleolar organizer regions (AgNOR) is still controversial in colorectal cancer. Sixty patients with colorectal cancer were studied by flow cytometric DNA analysis and AgNOR measurement, and their prognostic significance was tested. DNA index was closely linked to depth of invasion and lymph node metastasis, while AgNOR count did not correlate with such parameters. The survival curve was strongly influenced by depth of invasion, lymph node metastasis, and Dukes' stage but was not affected by DNA ploidy and AgNOR count. These results indicate that neither DNA ploidy nor AgNOR count correlates with survival of patients, although DNA ploidy is linked to progression of colorectal cancer.

Role of heat shock cognate 70 protein in import of ornithine transcarbamylase precursor into mammalian mitochondria

The roles of the 70-kDa cytosolic heat shock protein (hsp70) in import of precursor proteins into the mitochondria were postulated to be related to (i) unfolding of precursor proteins in the cytosol, (ii) maintenance of the import-competent state, and (iii) unfolding and transport of precursor proteins through contact sites, in cooperation with matrix hsp70. We examined roles of cytosolic hsp70 family members in import of ornithine transcarbamylase precursor (pOTC) into rat liver mitochondria, using an in vitro import system and antibodies against hsp70. Immunoblot analysis using an hsc70 (70-kDa heat shock cognate protein)-specific monoclonal antibody and a polyclonal antibody that reacts with both hsc70 and hsp70 showed that hsc70 is the only or major form of hsp70 family members in the rabbit reticulocyte lysate. The hsc70 antibody did not inhibit pOTC import when added prior to import assay. However, when pOTC was synthesized in the presence of the antibody and then subjected to import assay, pOTC import was markedly decreased. pOTC import was also decreased when the precursor was synthesized in the lysate depleted for hsc70 by treatment with hsc70 antibody-conjugated Sepharose. This reduction was almost completely restored by readdition of purified mouse hsc70 during pOTC synthesis. The readdition of hsc70 after pOTC synthesis and only during the import assay was not effective. Thus, once import competence of pOTC was lost, hsc70 was ineffective for restoration. Newly synthesized pOTC lost import competence in the absence of hsc70 somewhat more rapidly than in its presence. These results indicate that hsc70 is required during pOTC synthesis and not during import into the mitochondria. hsc70 presumably binds to pOTC polypeptide and maintains it in an import-competent form.

Clinical usefulness of thyroid-stimulating antibody measurement using Chinese hamster ovary cells expressing human thyrotropin receptors

Human thyrotropin (TSH) receptors were expressed in Chinese hamster ovary (CHO) cells using eukaryotic expression plasmid pCXN2, which contains beta-actin promoter. We measured cAMP stimulation in CHO cells expressing human TSH receptors (CHO-hTSH-R cells) by immunoglobulin G (IgG) of patients with Graves' disease and Hashimoto's thyroiditis, and compared the results with a conventional thyroid-stimulating antibody (TS-Ab) assay using porcine thyroid cells and a TSH-binding inhibiting immunoglobulin (TBII) assay. Nineteen untreated patients with Graves' disease, including a case who developed hyperthyroidism after interferon -alpha therapy for chronic hepatitis C, and 13 treated patients with Graves' disease, 10 patients with Hashimoto's thyroiditis and 8 control subjects were studied. In 19 untreated patients with Graves' disease, 17 patients showed positive CHO-hTSH-R cell stimulation, 11 patients showed positive porcine thyroid cell stimulation and 15 patients showed positive TBII. All the untreated patients showed positive results in at least one assay. Although significantly positive correlations were observed among CHO-hTSH-R cell stimulation, porcine thyroid cell stimulation and TBII activities, the IgG of several patients showed significant discrepancy in the assay results. In a patient with interferon-induced hyperthyroidism only CHO-hTSH-R cell stimulation was positive, while porcine thyroid cell stimulation and TBII were negative. After the treatment with propylthiouracil for 6 months, CHO-hTSH-R cell stimulation became negative. The IgG of patients with Hashimoto's thyroiditis did not show significant stimulation of CHO-hTSH-R cells. These results suggest that the CHO-hTSH-R cell stimulation assay is clinically useful for the diagnosis and follow-up of patients with Graves' disease.