Trans-suppression of gene expression by hepatitis C viral core protein

We have demonstrated that the truncated hepatitis C (HCV) core protein with its C-terminal hydrophobic domains deleted is translocated to the nucleus of transfected cells (22). In this study, intact and truncated core proteins of HCV were transiently expressed in a human hepatoblastoma cell line, HepG2, and their effects on the expression of the chloramphenycol acethyl transferase (CAT) gene driven by viral and cellular promoters were examined. The intact core protein of 22 kDa which is localized in the cytoplasm of the transfected cells suppressed the expression in all of the promoters tested. They were promoters of the SV40 early region, the c-fos oncogene, the retinoblastoma susceptibility gene, the beta-interferon gene and the beta-actin gene. In contrast, the truncated HCV core protein located in the nucleus did not show such a suppressive activity. The HCV core protein appears to function not only as a viral structural protein but as a regulator of gene expression and it might act as a suppressive factor for the cellular gene expression.

Bile flow in a mutant Sprague-Dawley rat with defective biliary excretion of glutathione

The Eisai hyperbilirubinemic rat is a mutant strain of Sprague-Dawley origin with hereditary defects in the biliary excretion of bilirubin glucuronide, glutathione, and several other organic anions. The correlation between bile flow and bile acid excretion rates during taurocholate infusion revealed that bile acid-independent flow was smaller in the mutant than in intact Sprague-Dawley rats (19.3 vs 56.0 microliters/kg per min), while bile acid-dependent flow was similar. The correlation between bile flow and glutathione excretion rates in Sprague-Dawley rats with modified hepatic glutathione levels revealed that a certain portion of bile flow was proportional to the biliary excretion of glutathione, with a coefficient of 551 bile per 1 mol glutathione. One-third of bile acid-independent bile flow in intact Sprague-Dawley rats was accounted for by glutathione osmosis, which feature was absent in the mutant rats.

Echography of inferior vena cava for estimating fluid removed from patients undergoing hemodialysis

Twenty-eight chronic hemodialysis patients were studied, and 118 consecutive measurements of the diameter of their inferior vena cava (VCD) were performed with ultrasonography. There was a significant correlation between the percent change in VCD in the expiratory phase (delta VCD-E%) and the percent change of in body weight (delta BW%). The average VCD-E in predialysis was 10.7 +/- 3.2 mm/m2 and this value decreased gradually following ultrafiltration and reached a minimal diameter of 7.5 +/- 2.8 mm/m2 in postdialysis. Three cases developed hypotension due to fluid removal. Their VCD-E value showed a rapid reduction below 7.5 mm/m2 in the early phase of hemodialysis, then maintained a plateau. The hypotension was thought to be caused by hypovolemia due to overdehydration. We conclude that VCD-E was an effective indicator for determining the volume of fluid removed, and the dry weight was attained safely and correctly by means of undergoing ultrafiltration to keep the value of VCD-E above 7.5 +/- 2.8 mm/m2.

Rarity of squamous cell carcinoma of the thyroid: autopsy review

Squamous cell carcinoma (SCC) of the thyroid is thought to be rare. However, SCC not infrequently occurs in conjunction with other histologic types of tumor. We reviewed 67 thyroid cancer autopsy cases obtained from two institutions from 1969 to 1981 and from 1975 to 1992, respectively. SCC was found in 19 cases (28.4%): 2 SCCs as the only malignancy and of uniform histologic type, 9 cases of tumors mixed with papillary carcinoma, and 8 cases of SCC mixed with papillary and anaplastic carcinomas. In only four of these cases was the SCC component found in the surgical specimens. These results indicate that the presence of SCC component is more likely to be found at the later stage of the disease.

Fine antigen specificity of human gamma delta T cell lines (V gamma 9+) established by repetitive stimulation with a serotype (KTH-1) of a gram-positive bacterium, Streptococcus sanguis

We have established human gamma delta T cell lines specific for Streptococcus sanguis (S. sanguis) KTH-1 present in normal oral cavity flora. The CD4-CD8-CD3+V gamma 9+V delta 1-CD45RO+ CD25+ T cell lines showed a proliferative response to the streptococcal antigen (Ag) in the presence of autologous antigen-presenting cells without apparent evidence of HLA restriction. The proliferative response of the gamma delta T cell lines was completely blocked by anti-TcR gamma delta monoclonal antibody (mAb) and anti-HLA class I mAb (W6/32), whereas anti-HLA classical class Ia mAb (B-H9; anti-HLA-A,B,C), anti-HLA class II mAb (anti-DR, anti-DQ, and anti-DP) and anti-CD4 mAb did not have any inhibitory effects. Surprisingly, the gamma delta T cell lines showed the proliferative response against the original bacterial Ag KTH-1 exclusively, and exhibited no cross-reactivity with nominal Ag such as purified protein derivative of tuberculin, tetanus toxoid and Mycobacterium tuberculosis, or the same species but different strain of S. sanguis, American Type Culture Collection (ATCC) standard strain (10556), or even with the same strain but different serotype of S. sanguis, KTH-3. Moreover, cytokine production of the gamma delta T cell lines was similar to the Th1 pattern [interferon-gamma, tumor necrosis factor (TNF)-alpha and TNF-beta]. They also produced interleukin-8 that functions as one of chemoattractants for polymorphonuclear cells. Using direct sequencing technique of the polymerase chain reaction products, we found that junctional diversity of the T cell receptor (TcR) used by the parental KTH-1 specific gamma delta T cell line and its subclones is rather limited. It is suggested that gamma delta T cells with canonical TcR could preferentially respond to KTH-1 Ag. Thus, in addition to a broad or cross-reactivity of gamma delta T cells against phylogenetically conserved stress/heat-shock protein, which is well characterized by others, some peripheral blood gamma delta T cells could recognize and kill exogenous agents with fine antigenic specificity to protect the body against them.

Neuro-Behçet disease with demyelination and gliosis of the frontal white matter

A rare case of neuro-Behçet disease with diffuse demyelination and gliosis of the frontal white matter is reported clinico-pathologically. The disease began with genital ulcer and recurrent oral aphthosis when the patient was 42 years of age. There was erythema, moderate fever, CSF (cerebrospinal fluid)-pleocytosis and elevated CSF-globulin. He was diagnosed as having neuro-Behçet disease and treated with prednisolone. He gradually became euphoric, disinhibited, indifferent and demented. His cranial CT showed diffuse low density areas in the bilateral frontal white matter. He became bedridden, akinetic mute and died from respiratory dysfunction 3 1/2 years after onset. The following neuropathological findings were observed: 1) Moderate demyelination and gliosis was present mainly in the frontal and parietal white matter. 2) There were many micro-spongious necrotic foci in the gray and white matters of the cerebrum, basal ganglia, thalamus, midbrain and pons, some of which were accompanied by gliosis. 3) From 1/2 to 1/3 of all micro-necrotic foci in the frontal white matter were old and accompanied by gliosis. The white matter containing numerous micro-necrotic foci had myelin pallor and gliosis. 4) There was neither micro-necrosis nor gliosis in the occipital lobe. The pathogenetic correlation of white matter lesions with primary and secondary circulatory disturbances is discussed.

Spontaneous adrenal and hepatic myelolipomas in the common marmoset

Myelolipomas occurring simultaneously in the adrenal and liver were found in a 2.7-yr-old, bred female common marmoset (Callithrix jacchus). The animal bore single adrenal and multiple hepatic myelolipomas. The adrenal myelolipoma consisted of mature adipose cells and focal collections of normal hematopoietic elements and was unencapsulated. In the liver, the myelolipomas, which were partially encapsulated, included a large amount of hematopoietic tissue and adipose cells that resembled normal bone marrow cells in various ways. Additionally, one of the multiple nodules contained several bony spicules with osteoblasts. Furthermore, there were invasive figures of hematopoietic cells, such as myeloblasts, erythroblasts, and megakaryocytes, in the hepatic sinusoids around the lesions. Thus, this case has some unusual morphological characteristics and is the first report, to our knowledge, on multiorganic myelolipomas in common marmosets.

The existence of protein kinase C in cone photoreceptors in the rat retina

We examined the localization of protein kinase C (PKC) in the rat retina, using a monoclonal antibody against PKC. The PKC immunoreactivities were localized in bipolar cells as reported previously, and also in outer and inner segments (OS and IS) of photoreceptor cells. As the PKC immunoreactive OS and IS of photoreceptors were very few in number, we hypothesized that these were of cone photoreceptors. We then examined whether the PKC immunoreactive OS and IS were bound by peanut agglutinin which was shown to bind specifically to cone OS and IS. Almost all of the PKC immunoreactive OS and IS showed PNA binding.

Reactive oxygen metabolite-induced toxicity to cultured bovine endothelial cells: status of cellular iron in mediating injury

We aimed to determine the status of iron in mediating oxidant-induced damage to cultured bovine aortic endothelial cells. Chromium-51-labeled cells were exposed to reaction mixtures of xanthine oxidase/hypoxanthine and glucose oxidase/glucose; these produce superoxide and hydrogen peroxide, or hydrogen peroxide, respectively. Xanthine oxidase caused a dose dependent increase of 51Cr release. Damage was prevented by allopurinol, oxypurinol, and extracellular catalase, but not by superoxide dismutase. Prevention of xanthine oxidase-induced damage by catalase was blocked by an inhibitor of catalase, aminotriazole. Glucose oxidase also caused a dose-dependent increase of 51Ci release. Glucose oxidase-induced injury, which was catalase-inhibitable, was not prevented by extracellular superoxide dismutase. Both addition of and pretreatment with deferoxamine (a chelator of Fe3+) prevented glucose oxidase-induced injury. The presence of phenanthroline (a chelator of divalent Fe2+) prevented glucose oxidase-induced 51Cr release, whereas pretreatment with the agent did not. Apotransferrin (a membrane impermeable iron binding protein) failed to influence damage. Neither deferoxamine nor phenanthroline influenced cellular antioxidant defenses, or inhibited lysis by non-oxidant toxic agents. Treatment with allopurinol and oxypurinol, which inhibited cellular xanthine oxidase, failed to prevent glucose oxidase injury. We conclude that (1) among the oxygen species extracellularly generated by xanthine oxidase/hypoxanthine, hydrogen peroxide induces damage via a reaction on cellular iron; (2) deferoxamine and phenanthroline protect cells by chelating Fe3+ and Fe2+, respectively; and (3) reduction of cellular stored iron (Fe3+) to Fe2+ may be prerequisite for mediation of oxidant-induced injury, but this occurs independently of extracellular superoxide or cellular xanthine oxidase-derived superoxide.

Expression of proliferating cell nuclear antigens in parathyroid glands of renal hyperparathyroidism

Total parathyroidectomy with autotransplantation of a small piece of the resected hyperplastic gland is currently the usual surgical procedure for renal hyperparathyroidism in Japan. Empirically, the smallest glands showing diffuse growth are selected for the graft. In order to seek the rationale for this procedure, we examined 50 cases of both nodular and diffuse hyperplastic parathyroid glands and five cases of recurrent grafted tissues histologically and immunohistochemically with anti-proliferating cell nuclear antigen (PCNA) antibody. The proliferative activity of the glands growing in diffuse fashion was much lower than that of those growing in nodular fashion (p < 0.05). All the parathyroid glands selected for grafting in the recurrent cases showed nodular growth. No relation was revealed between PCNA expression and the size of the glands, or between the former and the type of cell components (chief and oxyphilic cells). In nodular lesions, immunopositive cells were frequently distributed near the thick fibrous capsule. From these results, we conclude that parathyroid glands showing a diffuse growth pattern are indeed suitable for the graft. When only a nodular hyperplastic parathyroid gland is available, it is suggested that the central portion of the nodule may provide a better source for the graft with little change of recurrence.

Familial Creutzfeldt-Jakob disease: three autopsy cases of the panencephalopathic type

Three autopsy cases of panencephalopathic type of familial Creutzfeldt-Jakob disease (CJD) were investigated. Cases 1 (51-year-old male) and 3 (54-year-old female) were siblings and Case 2 (68-year-old female) was their aunt. In cases 1 and 3, the age of onset (Case 1:51, Case 3:53), duration of illness (Case 1:9 months, Case 3:8 months) and neuropsychiatric symptoms (pyramidal and extrapyramidal tracts involvements, blindness and dementia in chronological order) were similar, but in Case 2, the onset was later (66 years old), duration was longer (32 months) and the initial symptom was dementia. Myoclonus and apallic state in the terminal stage were common to all 3 cases. Neuropathologically, all 3 cases had characteristics that indicated panencephalopathic type of CJD. Cases 1 and 3 had similar neuropathological findings with characteristic circumscribed necrotic foci in the subcortical white matter. In Case 2 in contrast, diffuse demyelination and fibrillary gliosis in the cerebral white matter were observed without circumscribed necrotic foci. In the cerebellum of Case 3, granular cell loss was very slight. The other lesions in the cerebral cortex and striatum of the 3 cases were common. In conclusion, the clinical symptoms and neuropathological findings of our familial CJD cases were different from one another.

The induction of specific antitumor immunity by in vivo treatment with interleukin-1 and sonicated tumor extract in a murine model

BALB/c mice were pretreated intraperitoneally with interleukin-1 (IL-1) and sonicated tumor extract (SE) from plasmacytoma MOPC104E, 10, 7, and 4 days prior to the intraperitoneal or subcutaneous inoculation of MOPC104E cells, following which significant suppression was observed. The mean survival time and tumor diameter on day 21 were 46.7 days and 0 mm, respectively, in contrast to the 20.9 days and 20.4 mm of control mice. Mice pretreated with IL-1 and SE from MOPC104E (MOPC-SE) were not suppressed following fibrosarcoma MethA inoculation, which indicates the tumor specificity of immunity in this model. This systemically operating antitumor immunity was also achieved by the intramuscular administration of IL-1, or when tumor challenge was performed on day 7 or 14. Moreover, MOPC104E-specific delayed-type hypersensitivity was detected in these mice. The results of this study suggest the possibilities of a new type of active specific immunotherapy, which could prove useful as postsurgical adjuvant therapy for cancer patients.

Pironetin, a novel plant growth regulator produced by Streptomyces sp. NK10958. I. Taxonomy, production, isolation and preliminary characterization

A novel plant growth regulator, pironetin, was isolated from the culture broth of Streptomyces sp. NK10958. It was extracted from the culture broth with ethyl acetate and purified by column chromatographies. Pironetin showed 23% inhibition on the growth of rice plants without any loss of crop yield at 10 g/a on 9 days before heading.

Role of iron and glutathione redox cycle in acetaminophen-induced cytotoxicity to cultured rat hepatocytes

The aims of this study were to investigate the roles of iron as a catalyst in reactive oxygen metabolite-mediated cellular injury and of the endogenous antioxidant defenses against acetaminophen-induced cytotoxicity in cultured rat hepatocytes. Hepatocytes were isolated and cultured from either 3-methylcholanthrene-treated or untreated rats. Cytotoxicity was evaluated by measuring 51Cr and lactate dehydrogenase release. Acetaminophen caused dose-dependent cytotoxicity in 3-methylcholanthrene-treated, but not untreated, cells. There was a good correlation between 51Cr and lactate dehydrogenase release values. Pretreatment with both diethyl maleate, which covalently binds glutathione as catalyzed by glutathione-S-transferase, and bis(chloroethyl)-nitrosourea, an inhibitor of glutathione reductase, enhanced acetaminophen-induced cytotoxicity. Inhibition of endogenous catalase activity by pretreatment with aminotriazole did not affect acetaminophen-induced cellular damage. Addition of exogenous catalase failed to protect against acetaminophen-induced cytotoxicity. Preincubation with both deferoxamine, a ferric iron chelator, and phenanthroline, a ferrous iron chelator, diminished acetaminophen-induced cytotoxicity. These results indicate that iron is crucial in mediating acetaminophen-induced cytotoxicity and that the glutathione redox cycle, but not catalase, plays a critical role in the endogenous defenses against acetaminophen-induced cellular damage in cultured rat hepatocytes in vitro.

Long-acting nicardipine for elderly hypertensive patients: effect on diurnal variation of blood pressure

The effect of long-acting nicardipine tablets on diurnal variation of blood pressure was compared with that of standard nicardipine tablets and long-acting nifedipine tablets by 24-hour ambulatory blood pressure monitoring in 35 patients with hypertension. Long-acting nicardipine decreased systolic blood pressure in each age group, and there was no difference in its anti-hypertensive effect when compared with the other two drugs. All three drugs had no effect on the amplitude of daily blood pressure variation, and all three drugs decreased the baseline blood pressure in each age group when compared with untreated patients. In addition, no change was observed in the decrement of baseline blood pressure after switching from the other two drugs to long-acting nicardipine. Long-acting nicardipine had less effect on diurnal blood pressure variation than standard nicardipine tablets, which are administered three times daily. In each age group, long-acting nicardipine also more effectively inhibited the increase in cardiac work resulting from the morning rise phenomenon when compared with standard nicardipine tablets. These findings suggest that long-acting nicardipine may be a more useful preparation for the treatment of essential hypertension, particularly in elderly patients.

Glomerular expression of type III and type IV collagens in benign nephrosclerosis: immunohistochemical and in situ hybridization study

The development of glomerular sclerosis in benign nephrosclerosis (BNS) was studied. We investigated the intraglomerular expression of type III and IV collagens and their mRNAs by immunohistochemistry and by the in situ hybridization method. Formalin-fixed paraffin sections from 28 patients with BNS and 10 control cases were stained by the avidin-biotin complex (ABC) method using monoclonal antibodies for human type III and IV collagens. In the course of the sclerotic process of the glomerulus in BNS, the glomerular staining intensity of type IV collagen increased. The strongest staining was observed in the glomerulus at the early sclerotic stage, and intensity decreased slightly at the later stages. Although type III collagen was absent in normal and nonsclerotic glomeruli, peripheral regions of the sclerotic glomeruli were positive at the early sclerotic stage. Later, type III collagen was diffusely observed in the completely hyalinized glomeruli. The expression of type III and type IV collagen mRNAs was detected in the glomeruli of BNS by the non-radioactive in situ hybridization method using thymine-thymine (T-T) dimerized synthetic oligonucleotides. The number of mRNA positive cells for type III and type IV collagens increased at the presclerotic and early sclerotic stages. But these cells gradually decreased in number as glomerular sclerosis developed. We concluded that type III collagen was presumably synthesized by the intraglomerular cells and may contribute to the development of glomerular sclerosis in BNS along with type IV collagen.

Rotational occlusion of the vertebral artery at the atlantoaxial joint: is it truly physiological?

We present a patient with vertebrobasilar insufficiency, with vertigo and horizontal nystagmus, induced by turning the head to the right. Angiography demonstrated transient occlusion of the left vertebral artery at the atlantoaxial joint during rotation of the head. The pathogenesis and angiographic findings are discussed.

Graft-versus-host reaction and GvH disease

Chronic GvHR was induced by inoculating parental lymphoid cells into F1 hybrid mouse. Combination of ATL and ATH, which were congenic recombinant strains differing only in H-2I and S region from each other, was chosen to induce class II-GvHR. Selective activation against partner's alloantigen of graft CD4+ T cells was the primary event of the GvHR and then led to concomitant activation of both graft and host cells. Immune dysregulation among these cells made the GvHR-mouse express various chronic diseases including immune complex glomerulonephritis, autoimmune-like lesions of the liver or the salivary gland, tumor-like proliferations of T cells and abnormal extramedullary hematopoiesis. Chronic GvHR was also induced by a preferential but not a selective activation of graft CD4+ T cells. A combination of DBA/2 and C57BL/6, which differ in whole MHC antigens, was an example. When D2 cells, but not B6 cells, were incoulated into the BDF1 mouse, predominant activation of CD4+ cells over CD8+ cells were observed. Contributing factors to this phenomenon were low responsiveness of graft CD8+ T cells to allogeneic class I MHC antigens and anti-parent activity of host CD8+ cells. Thus both graft and host cells participate either actively or passively in the reaction induced in the parent --> F1 experimental system of GvHR/D.

[Current status and prospects for targeted therapy for thyroid cancer]

New strategies are currently being developed with regard to targeted (missile) therapy for cancer using anticancer agent-labeled specific antibodies. A range of problems prevent their clinical application, however, because each specific cancer may not yet have a known unique antigen. In turn, this serves to impede the development of specific antibodies. Regarding thyroid cancer, no reports of targeted therapy have appeared since specific antigens remain to be identified. Monoclonal antibodies A2B5, HISL-19 and 4F2 bind to neuroendocrine tumors (A2B5, HISL-19) and severe malignant tumors (4F2) indicating rapid growth, enabling these tumors to express common anti-genetic determinants to our monoclonal antibodies. The immunohistochemical study for thyroid cancers revealed that A2B5 and HISL-19 only react with medullary carcinoma and that 4F2 only reacts with anaplastic carcinoma. When 131I-labeled A2B5 was injected into the rat bearing insulinoma, the antigen of which is common to medullary carcinoma of the thyroid, clear accumulation of radiolabeled antibody corresponding to the transplanted tumor was observed by scintiscanning. Furthermore, the biochemical study undertaken to identify anti-genetic protein using the Western blotting procedure demonstrated new HISL-19 antigen in medullary carcinoma of the thyroid, which is not recognized in benign endocrine tumor, and 4F2 antigen in anaplastic carcinoma. Since these antigens do not circulate in the blood stream, the administered antibody reaches the targeted lesion without decreasing antibody titer. Although many problems remain, such as the effect on normal cells and affinity to the targeted lesion, our current aim is to establish an efficient and effective chemotherapy using monoclonal antibodies in medullary carcinoma and anaplastic carcinoma arising in the thyroid.

Acute low-tone sensorineural hearing loss without vertigo

OBJECTIVE

To study the pathophysiological features of acute low-tone sensorineural hearing loss without vertigo (ALHL) and its correlation with Meniere's disease.

DESIGN

Retrospective review of medical charts of patients with ALHL.

SETTING

University hospital clinic.

PARTICIPANTS

Eighty consecutive patients with ALHL, including 45 patients whose conditions were followed up for more than 3 years (average, 5 years 2 months; range, 3 years 3 months to 8 years).

OUTCOME MEASURES

Age and sex distributions and results of audiological and neuro-otological tests, initial outcome, recurrence rates, and differences between patients with and without recurrence.

RESULTS

About 75% (62/80) of the patients were between the ages of 30 and 60 years and the female-male ratio was 2:6. Positive glycerol test results were found in 74% (26/35) of patients and abnormally increased negative summating potential/action potential ratio in 63% (50/80). No abnormalities were found on neuro-otological tests. Hearing loss improved within 3 months in 84% (67/80) of the patients. Of 45 patients followed up for more than 3 years, 28 (62%) showed no evidence of recurrence, 12 (27%) developed cochlear Meniere's disease, and five (11%) developed classic Meniere's disease. No significant differences were found at the first examination between patients with and without recurrence.

CONCLUSIONS

These results suggest that ALHL may be caused by endolymphatic hydrops confined to the cochlea and that ALHL does not always lead to cochlear or classic Meniere's disease.

The synergistic antitumor effect of recombinant interleukin-1 and low-dose of cyclophosphamide in tumor-bearing mice

Intraperitoneal (i.p.) treatment of MOPC104E ascitic tumor-bearing BALB/c mice with interleukin-1 (IL-1) followed by a low dose of cyclophosphamide (CPA) resulted in synergistic prolongation of their survival time. This antitumor effect was abolished when administration of CPA preceded that of IL-1. The combined i.p. therapy also eradicated subcutaneous (s.c.) tumors, indicating a systemically operating antitumor mechanism. In Winn assay, splenocytes from MOPC104E-bearing mice treated with the combined therapy completely suppressed the growth of MOPC104E cells, but not that of another syngeneic tumor cell line, RL female-8 cells. This tumor-neutralizing activity was completely abrogated by treatment with anti-asialo-GM1 or anti-Thy1.2 and complement, and reduced by treatment with anti-Lyt2.2 and complement. Treatment of splenocytes with 1-leucine methyl ester (Leu0Me), which depletes natural killer (NK) cells and macrophages in vitro, did not affect the neutralizing activity.

Protection of cultured rat gastric cells against oxidant-induced damage by exogenous glutathione

BACKGROUND/AIMS

Reduced glutathione (GSH) is an intracellular protectant against oxidants. The present study determined whether extracellular GSH protects against oxidant damage or whether an uptake system of GSH is present in cultured gastric cells.

METHODS

Hydrogen peroxide was generated by glucose oxidase and glucose. Cytotoxicity was assessed by 51Cr release. Intracellular GSH was assayed by the method of Tietze.

RESULTS

Pretreatment with extracellular GSH decreased H2O2-induced 51Cr release. Treatment with GSH enhanced cellular GSH content. Protection by pretreatment with GSH was prevented by buthionine sulfoximine (an inhibitor of gamma-glutamylcysteine synthetase). Enhancement of intracellular GSH was also prevented by buthionine sulfoximine. Acivicin (an inhibitor of gamma-glutamyl transpeptidase) prevented intracellular accumulation of GSH from extracellular GSH. Cysteine was effective in preventing damage and enhancing intracellular GSH content, whereas both glutamine and glycine were not.

CONCLUSIONS

Extracellular GSH protects cultured gastric cells from H2O2 damage by accelerating intracellular GSH synthesis; this is mediated by membrane-bound gamma-glutamyl transpeptidase acting on extracellular GSH (which supplies these cells with cysteine) and then by intracellular gamma-glutamylcysteine synthetase.

Penile verrucous carcinoma with anaplastic transformation following radiotherapy. A case report with human papillomavirus typing and flow cytometric DNA studies

We report a case of penile verrucous carcinoma with anaplastic transformation after radiotherapy. A 49-year-old man with penile verrucous carcinoma initially underwent excision and chemotherapy followed by radiotherapy when the carcinoma recurred locally. Twenty-four months after the completion of radiotherapy, the verrucous cancer transformed to an anaplastic spindle-cell carcinoma, which resulted in his death 10 months after diagnosis. Autopsy confirmed a huge hemorrhagic recurrent lesion and lung metastases. In situ hybridization with biotinylated DNA probes did not detect any type of human papillomavirus (HPV) (types 6/11, 16/18, and 31/33/51) in either the primary or the anaplastic tumor. Immunohistochemical HPV capsid antigens were also negative in both lesions. A flow cytometric analysis, using paraffin-embedded materials, showed a diploid DNA content in the excised verrucous carcinoma and an aneuploid content in the anaplastic tumor. This patient most likely had radiation-induced transformation of an anaplastic carcinoma. Wide excision and, if necessary, amputation, are preferred to radiotherapy.

Biliary excretion of cholephilic organic dyes in glutathione-depleted rats

Sprague-Dawley rats were treated with a combination of buthionine sulfoximine (2.5 mmol/kg body wt) and diethyl maleate (6.2 mmol/kg). After 4 h, the hepatic glutathione was depleted to 0.02 +/- 0.01 mumol/g liver (mean +/- SD, n = 6) (4.73 +/- 0.29 mumol/g in controls (n = 6), p < 0.005). The bile flow rate was lower in treated animals than in controls (39.0 +/- 11.2 vs. 73.7 +/- 13.7 microliters.kg-1.min-1, p < 0.005). Bile concentrations of bile acids, phospholipids, and cholesterol were not changed compared to controls, while glutathione was virtually absent from the bile. A bolus of indocyanine green (6.5 mumol/kg), rose bengal (6.5 mumol/kg), or sulfobromophthalein-glutathione conjugate (20 mumol/kg) was injected i.v. and the biliary excretion was monitored. In glutathione-depleted rats, the excretion of indocyanine green was delayed, and the cumulative excretion in 90 min was 36 +/- 8% (n = 6) of the injected dose (79 +/- 18% in controls (n = 7), p < 0.005). The bile concentration of indocyanine green was lower in the glutathione-depleted rats than in controls, while the other dyes increased. The plasma disappearance curve of indocyanine green was not significantly altered by the treatment, whereas the hepatic retention of indocyanine green 90 min after the injection was significantly increased (58 +/- 12% of the injected dose vs. 8 +/- 2% in controls, p < 0.005). The results indicate that depletion of hepatic glutathione inhibits biliary excretion of indocyanine green.