Subchronic toxicity study of methyl hesperidin in mice

A subchronic toxicity study of methyl hesperidin was performed using B6C3F1 mice. The flavonoid was administered to groups of ten males and ten females in dietary levels of 0, 0.3, 0.6, 1.25, 2.5 and 5.0% for 13 weeks. No significant treatment-related differences were found in data for body weights, food and water consumption, hematology, clinical chemistry and organ weights. Furthermore, no effects of treatment were observed on gross and histopathological examination of the major organs. The present experiment thus demonstrated that methyl hesperidin exerts no obvious toxic effects in mice of either sex when administered at a level as high as 5.0% in the diet.

No enhancing effects of calcium/magnesium salts of L-glutamate and L-ascorbate on tumor development in a rat medium-term multiorgan carcinogenesis bioassay

Calcium/magnesium salts of L-glutamate and L-ascorbate were tested for modification potential using a rat multiorgan carcinogenesis bioassay. Following sequential treatment with three different carcinogens (diethylnitrosamine, N-methylnitrosourea, and dihydroxydi-N-propylnitrosamine) over a 4-wk period, rats were given diet containing 5% monocalcium di-L-glutamate tetrahydrate (Ca-glutamate), 2.5% monomagnesium di-L-glutamate tetrahydrate (Mg-glutamate), 5% L-glutamic acid, 5% monocalcium di-L-ascorbate dihydrate (Ca-ascorbate), 2.5% monomagnesium di-L-ascorbate dihydrate (Mg-ascorbate), or 5% L-ascorbic acid for 16 wk. Body weight increase was slightly suppressed in the groups receiving Ca-ascorbate, Mg-ascorbate, and ascorbic acid supplementation after the carcinogen treatments. While administration of Ca-glutamate or Ca-ascorbate raised urinary pH, ascorbic acid values were decreased. Concentrations of calcium and magnesium ions in the urine increased after ingestion of Ca-glutamate or Ca-ascorbate, and Mg-glutamate or Mg-ascorbate, respectively, but phosphorus levels decreased in all groups given calcium and magnesium salts. No consistent treatment-related changes in the concentrations of sodium or potassium ions in the urine were detected. Histopathological investigation at wk 20 did not demonstrate any modification of tumorigenesis with regard to the incidence of frequency of lesions developing in the various target organs/tissues. The present results thus revealed no apparent enhancement of carcinogenesis at any site, including the urinary system, by calcium or magnesium salts using the present rat multiorgan carcinogenesis bioassay.

Effects of interferon-alpha treatment on hepatitis B virus antigen-specific immunologic responses in patients with chronic hepatitis B

Studies were undertaken to evaluate the relationship between the immune responses and the effectiveness of interferon-alpha treatment in 21 patients with HBeAg-positive chronic active hepatitis. Peripheral blood mononuclear cells (PBMC), obtained on four occasions during an 8-week course of IFN-alpha therapy, were cultured with recombinant HBcAg, purified HBeAg or pokeweed mitogen (PWM). During follow-up for 6 months after therapy, clearance of serum HBeAg was observed in eight patients designated as responders. Immunological responses of PBMC obtained before treatment did not differ between responders and non-responders. In responders, IFN-gamma and anti-HBc production was depressed during therapy, but recovered to above the pretreatment level at the end of and/or after cessation of therapy, while lymphocyte proliferation was enhanced during therapy with a subsequent decline to baseline value. In non-responders, such changes were modest throughout the study, and anti-HBc response remained decreased even after cessation of therapy. These results indicate that PBMC of responders have immunologically different responses to IFN-alpha therapy when compared with non-responders.

Subchronic oral toxicity study of captafol in B6C3F1 mice

The effects of subchronic administration of captafol were studied in B6C3F1 mice given dose levels of 0, 0.3, 0.625, and 1.25% in the diet for 12 wk. There was a dose-related decrease in body weight gain during the 12-wk experiment and a loss of body weight in the 1.25% group of both sexes. Whiles the mice given captafol consumed less diet than the control mice, this was not directly dose-related. The relative weights of liver demonstrated a tendency for dose-dependent increase. Light-microscopic examination revealed cytoplasmic vacuolar degeneration, depending in severity on the dosage, in the livers of both sexes given captafol. In conclusion, the findings obtained from the present subchronic toxicity study indicated the liver to be a primary target organ.

Effects of recombinant human granulocyte colony-stimulating factor on neutrophil functions in aged animals

We have studied the effects of recombinant human granulocyte colony-stimulating factor (rG-CSF) on granulopoiesis and neutrophil functions in aged rats and aged mice. We subcutaneously injected rG-CSF or control vehicle into aged rats (22 months old and 25 months old) for 7 consecutive days, counted the peripheral neutrophils and evaluated the functions of neutrophils isolated from venous blood. The peripheral neutrophil count in aged rats tended to be increased as compared with that in young rats (11 weeks old). However, the neutrophils in aged rats exhibited a decline of superoxide anion (O2-) release and phagocytic activity as compared with young rats. The peripheral neutrophil count in aged rats was significantly increased 5-6-fold as many as the control value by rG-CSF treatment, which was accompanied by a significant enhancement of O2- release and of phagocytic activity being restored to normal levels or better. In another series of experiments, we subcutaneously injected rG-CSF or control vehicle into aged mice (24-28 months old) or young mice (8 weeks old) for 7 consecutive days, and evaluated the functions of neutrophils isolated from peritoneal cavity. The peritoneal exudate neutrophils from the aged mice exhibited a decline of phagocytic and chemotactic activity as compared with the young mice. These functions in both young and aged mice were significantly enhanced by rG-CSF-treatment, and these functions in rG-CSF-treated aged mice were restored to a level higher than the level in control young mice. These findings demonstrate that rG-CSF is capable of enhancing granulopoiesis and restoring the age-related decline of neutrophil functions.

Influence of caffeic acid and other o-dihydroxybenzene derivatives on N-methyl-N'-nitro-N-nitrosoguanidine-initiated rat forestomach carcinogenesis

Promotion effects of the o-dihydroxybenzene derivatives, protocatechuic acid (PCA), dopamine hydrochloride (DAH), dl-dopa and caffeic acid on forestomach and glandular stomach carcinogenesis were investigated in rats pretreated with N-methyl-N'-nitro-N-nitrosoguanidine (MNNG). Groups of 20 male F344 rats were given a single intragastric administration of 150 mg/kg body wt MNNG and starting 1 week later than received diet containing 1.5% PCA, 1.5% DAH, 1.5% dl-dopa or 1% caffeic acid or basal diet alone for 51 weeks and then killed. Other groups of 10-15 rats were given PCA, DAH, dl-dopa or basal diet alone without the MNNG pretreatment. On histological assessment, the incidences of forestomach papillomas and squamous cell carcinomas were significantly enhanced in the group treated with caffeic acid (95 and 100%) as compared with the control values (35 and 10%). Although the incidence was not different, the number of papillomas per rat in the group given DAH (0.79 +/- 0.79) was also significantly increased (0.35 +/- 0.49). PCA and dl-dopa treatments did not modify the development of neoplastic lesions in the forestomach epithelium to any significant extent. None of the four chemicals enhanced glandular stomach carcinogenesis. The results thus demonstrated that whereas caffeic acid and DAH respectively, exert strong and weak promotion activity for rat forestomach carcinogenesis this promotion potential is not shared by all dihydroxybenzene derivatives. An influence of substituents in the para position in addition to the o-dihydroxy moiety is indicated.

Inorganic alkalizers and acidifiers under conditions of high urinary Na+ or K+ on cell proliferation and two-stage carcinogenesis in the rat bladder

Effects of alkalizers and acidifiers on bladder cell proliferation and two-stage carcinogenesis were investigated under conditions of high urinary Na+ or K+. Animals were given 0.05% N-butyl-N-(4-hydroxybutyl)nitrosamine in their drinking water for 4 weeks and then received Na3PO4, NaH2PO4, NaCl, NaH2PO4 + NaCl, K3PO4, KH2PO4, KCl, KH2PO4 + KCl or no chemical supplement in the diet from weeks 5 to 8 and from weeks 12 to 20. During weeks 9 to 11, the rats were fed 3% uracil in their diet for acceleration of promotion. Na3PO4 or K3PO4 induced marked natriuresis or kaluresis and alkalinuria associated with strong promoting potential for bladder carcinogenesis. NaH2PO4 induced moderate natriuresis and aciduria and exhibited weak promoting activity. NaH2PO4 + NaCl or KH2PO4 + KCl caused marked increase in the respective cation levels and aciduria with elevation of promotion as compared to NaH2PO4 or KH2PO4 alone. NaCl or KCl induced moderate natriuresis or kaluresis and did not alter urinary pH. NaCl but not KCl also exerted weak promoting activity for bladder carcinogenesis. Increased DNA synthesis after test chemical exposure for 8 weeks and morphological alterations observed by scanning electron microscopy in the bladder epithelium were only quantitatively linked with promoting activity in the Na3PO4 case. With the other treatments no clear correlation between early cell proliferation and promotion potential was apparent. The present results suggest that although elevation in urinary Na+ or K+ level may be an essential factor for promotion of rat bladder carcinogenesis, the action of these cations may depend strongly on urinary alkalinity.

Lack of carcinogenicity of tragacanth gum in B6C3F1 mice

Tragacanth gum was administered at dietary levels of 0 (control), 1.25 and 5.0% to groups of 50 male and 50 female B6C3F1 mice for 96 wk after which all animals were maintained on a basal diet without tragacanth gum for a further 10 wk. Mean body weights of females in the 5.0% and 1.25% groups were lower than those of the controls after 11 and 16 wk, respectively. However, there were no treatment-related clinical signs or adverse effects on survival rate, urinalysis, haematology, blood biochemistry and organ weight. While detailed histopathology revealed the development of squamous cell hyperplasias, papillomas and one carcinoma in the forestomach, there was no significant treatment-related increase in the incidence of any preneoplastic or neoplastic lesion. Thus, under the experimental conditions used, tragacanth gum was not carcinogenic in B6C3F1 mice of either sex.

[The oral 1-25 dihydroxyvitamin D3 pulse therapy in hemodialysis patients for the early treatment of secondary hyperparathyroidism]

It is said that maintenance hemodialysis patients are already suffering from secondary hyperparathyroidism (2HPT) from early stage of chronic renal failure. The treatment of 2HPT in this stage is very important for preventing renal osteodystrophy (ROD). But many long-term dialysis patients are still afflicted with ROD although vitamin D have been used for treatment. In this study, an oral administration of 1-25 (OH)2 D3 (4 micrograms) with pulse therapy twice a week at the day before hemodialysis was started for 12 weeks. The concentration of 1-25 (OH)2D3, total calcium (Ca), ionized calcium (Ca++), alkaline phosphatase (ALP) and parathyroid hormone (PHT) in serum were measured not only before and after every 2 hours of administration a day, but also for 12 weeks after that. The peak of serum 1-25 (OH)2D3 could be sufficiently elevated after 8 hours, and the slight peak of Ca++ could be seen after 8 hours as well. But the level of total calcium could not increased. Although the level of only HS-PTH has not increased after 24 hours, a significant reduction in serum level of C-PTH, intact-PTH and HS-PTH could be recognized after 12 weeks finally. This pulse therapy was effective in reducing the serum level of PTH in this early stage from beginning hemodialysis. But, it needs further studies for the standard treatment.

Low susceptibility of nude mice to induction of invasive urinary bladder cancers by N-ethyl-N-(4-hydroxybutyl)nitrosamine

A time- and dose-dependent study of N-ethyl-N-(4-hydroxybutyl)nitrosamine (EHBN) bladder carcinogenesis was performed in nude mice maintained on tap water containing 0.025% EHBN for 4, 12, and 20 weeks ad libitum. A total of 13 invasive tumors, comprising 11 transitional cell carcinomas (TCCs) (84.6%) and 2 squamous cell carcinomas (SCCs) (15.4%), were found. Compared with previous results for B6C3F1 mice exposed to the same EHBN insult, the numbers of invasive carcinomas induced in nude mice, and especially of SCCs, were low. In order to ascertain whether this difference in cancer incidence between nude and B6C3F1 mice was due to variation in urinary excretion, the metabolism of EHBN was also investigated and compared with that of N-butyl-N-(4-hydroxybutyl)nitrosamine (BBN). Respective total urinary excretions over 48 hr of N-ethyl-N-(3-carboxypropyl)nitrosamine (ECPN) or N-butyl-N-(3-carboxypropyl)nitrosamine (BCPN), the ultimate carcinogenic species of EHBN or BBN, were 822.4 +/- 41.4 micrograms and 530.4 +/- 81.0 micrograms, respectively, in nude mice, and 800.6 +/- 83.7 micrograms and 407.8 +/- 69.7 micrograms, respectively, in B6C3F1 mice. In conclusion, although it is apparent that nude mice have a low susceptibility to EHBN induction of urinary bladder cancer, this does not appear to be dependent on reduced metabolism to the active form.

Selective induction of rat urinary bladder tumors by simultaneous administration of 3,2'-dimethyl-4-aminobiphenyl (DMAB) and butylated hydroxyanisole or butylated hydroxytoluene is associated with increased DMAB-DNA adduct formation

Modification of 3,2'-dimethyl-4-aminobiphenyl (DMAB) multi-organ carcinogenesis by simultaneous treatment with butylated hydroxyanisole (BHA) or butylated hydroxytoluene (BHT) was studied using young and old male F344 rats. Animals, 4 or 54 weeks old, were given DMAB (s.c. injection of 50 mg/kg body wt once a week for 10 weeks) along with BHA (2.0% in diet for 11 weeks) or BHT (1.0% in diet for 11 weeks). The experiments were terminated 55 weeks after the commencement. Combined administration of BHA or BHT with the carcinogen resulted in development of urinary bladder tumors in greater than 90% of both young and old rats thus treated, whereas no tumors were induced in animals given DMAB alone. In contrast, the appearance of preneoplastic lesions in the liver and pancreas was reduced by BHA or BHT treatment. Tumor development (less than 30% incidence) was also evident in the small and large intestines, prostate, preputial glands, skin/subcutis and ear duct, with no modification by BHA or BHT. No ageing effects were evident. The formations of DMAB-DNA adducts, evaluated by the enzyme-linked immunosorbent assay and immunohistochemical staining, correlated well with tumorigenesis in the urinary bladder, liver and pancreas. The selective enhancement of urinary bladder tumor induction by BHA and BHT appeared to be due to both increased DMAB-DNA adduct formation caused by metabolic alteration of DMAB in the liver and increased DNA synthesis in the urothelial cells.

Comparative promoting activities of phosphate salts on rat two-stage bladder carcinogenesis under conditions of equivalent urinary Na+ or K+ levels

Promoting effects of Na or K phosphate salts on rat two-stage bladder carcinogenesis were compared. Animals were treated with 0.05% N-butyl-N-(4-hydroxybutyl)nitrosamine (BBN) in their drinking water for 4 weeks and thereafter received 1.4% Na3PO4, 2.0% NaH2PO4, 1.0% K3PO4, or 2.5% KH2PO4, these dietary concentrations being selected because they result in approximately equal levels of Na+ and K+ in the urine, equivalent to moderate natriuresis or kaluresis in comparison with our previous data. Treatment with Na3PO4 or K3PO4 induced significant increase in urinary pH compared with control values, whereas urinary pH in the NaH2PO4 and KH2PO4 groups was comparable to control values. With regard to preneoplastic lesion development, both incidences and multiplicity were significantly increased in the groups given Na3PO4 or K3PO4 compared with both controls and NaH2PO4 or KH2PO4 groups, respectively. Furthermore, treatment with Na3PO4 significantly increased multiplicity of papillomas, accompanied by a tendency to increased incidence. No statistically significant difference in promoting potential between Na3PO4 and K3PO4 groups was evident. The present results thus suggest that tumor promotion under conditions of moderate natriuresis or kaluresis depends primarily on high urinary pH.

Carcinogenicity of captafol in F344/DuCrj rats

Captafol was administered at dietary levels of 0 (control), 750 and 1,500 parts per million (ppm) to groups of 50 male and 50 female F344/DuCrj rats for 104 weeks, and then all animals were maintained without captafol for a further 8 weeks, and killed in week 113. Renal cell carcinoma was found in eight of 50 male rats treated with 1,500 ppm and in one of 50 male rats treated with 750 ppm of captafol. The incidences of renal adenomas, including micro-adenomas, and basophilic altered cell tubules were significantly higher in both sexes treated with captafol than in controls, and the increases were apparently dose-dependent except that of adenomas in females. The incidences of neoplastic and preneoplastic lesions of the kidney in captafol-treated animals were higher in males than in females. Captafol also induced hepatocellular carcinomas in four of 50 female rats in the 1,500 ppm group. The incidences of hyperplastic (neoplastic) nodules and foci of cellular alterations in the liver were also significantly increased in both sexes treated with captafol, the increases being dose-dependent. In conclusion, captafol induced renal cell carcinomas in male rats and hepatocellular carcinomas in female rats.

[How to discriminate between vibration syndrome and local fatigue of motorcyclists]

Motorcyclists who work in some offices sometimes complained of coldness, pain and numbness of upper limbs. We studied how to discriminate between vibration syndrome and local fatigue of the motorcyclists. Subjects are 42 motorcyclists of an office in Aichi prefecture. 25 of them held several letters in their left hand when they delivered the letters. They complained of coldness, pain and numbness in the left upper limbs more than in the right limbs (p less than 0.01). We think that it is the local fatigue rather than the disorder of vibration syndrome that causes such symptoms. So it is very important to recognize the existence of local fatigue in order to know how to discriminate between vibration syndrome and local fatigue of the motorcyclists.

Recombinant human alpha-interferon therapy for chronic non-A, non-B hepatitis: second report

Four million units per day of recombinant human alpha-interferon were administered three times weekly for 16 wk to 26 patients with chronic non-A, non-B hepatitis. The efficacy of therapy was assessed by comparing it with the results in the nontreated patients, or with our previous study in which we administered 2 million units per day of interferon. The treatment was discontinued in four patients 8 wk after start of therapy because there was no improvement in serum aminotransferase levels. The remaining 22 patients completed the treatment schedule, and their aminotransferase values showed significant decreases throughout the therapy and during the follow-up period, compared with their baseline levels or the nontreated group. After 3 months of follow-up, normal aminotransferase activities were seen in eight treated patients. In four of these patients, liver histology showed a marked improvement in inflammation and parenchymal cell necrosis. Percent change from pretreatment level of serum 2',5'-oligoadenylate synthetase activity was significantly higher in the aminotransferase-normalized group than in the nonnormalized group during therapy. The present study suggested that a higher dose of alpha-interferon could control the disease activity more effectively in patients with chronic non-A, non-B hepatitis.

[Porphyria cutanea tarda in a chronic hemodialysis patient]

After 6 months on hemodialysis, a 58-year-old male patient with diabetes developed photosensitive bullous dermatosis on his hands and face. There was no evidence of liver diseases although the patient had a history of excessive alcohol consumption. He was suspected to have iron overload in the liver. Analysis of porphyrins in plasma, hemofiltrate, urine and feces by high performance liquid chromatography revealed significantly high levels in these samples with a porphyrin profiles which is consistent with porphyria cutanea tarda. The fluorometric assays of plasma also disclosed an elevated plasma porphyrin level. And it seemed that there were correlation between the fluctuation of vesicle formation, serum ferritin level and plasma porphyrin level. Small volume plasma exchange temporarily reduced the plasma porphyrin level and prevented vesicle formation.

[Neoplastic angioendotheliosis: a case of T cell lymphoma positive for S-100 protein]

A 63-year-old woman presented with painless, firm, subcutaneous nodules on her legs and trunk. The lesions were annular or serpiginous and their surface was livid-red to pale-red. Superficial lymph nodes were not palpable. Upper gastrointestinal series, barium enema, Ga scintigraphy, and CT findings were negative. Histological examination revealed deep dermal vessels occupied by neoplastic cells and fibrin thrombi. We diagnosed her as having neoplastic angioendotheliosis. Electron microscopically, tumor cells lacked Weibel-Palade bodies. Immunohistochemically, the tumor cells were positive for leukocyte common antigen, T11, MT-1, HLA-DR and S-100 protein. They were negative for Factor VIII-related antigen, epithelial membrane antigen, carcinoembryonic antigen, B-1, and B-2. Immunoelectron microscopic study showed that their nuclei, cytoplasma, and cell membranes were positive for S-100 protein. Based on these findings, we diagnosed her as having T cell lymphoma. The patient rejected chemotherapy and was discharged. Three months after discharge, right hemiplegia developed. Brain CT scan revealed enhanced masses in the left frontal, temporal, and occipital lobes. Craniotomy showed only gliosis and hemorrhage. She died of cerebral bleeding three months after craniotomy.

[Two cases of scleroderma associated with vibration syndrome]

Case 1, a 49-year-old male who had been engaged in repair and reclamation of automobile tires, developed symptoms of vibration syndrome (Raynaud's phenomenon, numbness of both hands, tinnitus and impaired hearing) after some 30 years' use of a grinder and impact wrench. Two years thereafter, multiple sclerodermic lesions appeared over the trunk, upper extremities, and thighs; these disappeared about 2 years later. Histologically, hyperplasia and nodular swelling of collagen bundles were present in the dermis. An immunological study showed the serum to be positive for anti-centromere antibody, but no visceral lesions were demonstrable. This case corresponded to generalized morphea. Case 2, a 53-year-old male, developed symptoms of vibration syndrome (Raynaud's phenomenon, numbness of both hands, impaired hearing and arthralgia) after 25 years' use of a jack hammer in a quarry. Thereafter, sclerodermic changes of the forearms, lower legs, face and abdomen occurred with an associated sclerodactyly. Histological examination of involved skin revealed diffuse hyperplasia and homogenization of collagen bundles throughout the entire thickness of the dermis. These findings, together with serum positivity for anti-RNP antibody and dilation of the lower portion of the esophagus, led us to a diagnosis of progressive systemic sclerosis. We inferred that the vibration syndrome in the present cases might be related etiologically to these forms of scleroderma.

[A case of primary malignant fibrous histiocytoma of the right lung]

A malignant fibrous histiocytoma (MFH) is the most common soft tissue sarcoma found in adults, but a primary MFH of the lung is very rare. A chest X-ray taken of a 73-year-old man revealed a massive lesion in the right upper lobe, and a subsequent right upper lobe lobectomy uncovered a soft, light yellow tumor in the right S3 area, measuring 2.8 x 2.6 x 1.7 cm. Histologically, the tumor manifested a typical storiform pattern of spindle-sharp cells with no sign of a myosarcoma. As no abnormal lesion was detected in the abdomen and extremities, the tumor was diagnosed as a primary MFH of the lung.