Collaborative work to evaluate toxicity on male reproductive organs by repeated dose studies in rats 7). Effects of reserpine in 2- and 4-weeks studies.

To assess the efficacy of different period of treatment for evaluating male reproductive toxicity in rats, reserpine was subcutaneously administered on a daily basis to male Sprague-Dawley rats at dosages of 0.05, 0.1 or 0.2 mg/kg for 2 weeks or at dosages of 0.05 or 0.1 mg/kg for 4 weeks. At the end of the administration period the animals were sacrificed and sperm counts, organ weights and histopathological changes in the reproductive organs were examined. The sperm number in the caudal epididymis and genital organ weights were not affected by reserpine with either 2- or 4-weeks treatment. In the 4-weeks study, histopathological examination of the testes revealed retention of step 19 spermatids in the seminiferous tubules of stages IX to XII and decreased secretory content of the prostate in the 0.05 and 0.1 mg/kg groups. In the 2-weeks study, although no distinct histopathological changes were observed in the 0.05 mg/kg group, decreased secretory content of the prostate, apoptosis of spermatocytes in the seminiferous tubules of stage VII and cell debris of the epididymis were observed in the 0.1 and 0.2 mg/kg groups. These results suggested that 2-weeks treatment with reserpine is sufficient for detection of testicular toxicity, although higher dosage levels are appropriate than for 4-weeks treatment.

Serum insulin and lipoprotein(a) concentrations. The Jichi Medical School Cohort Study.

OBJECTIVE: To examine the relationship between serum insulin and lipoprotein (a) [Lp(a)] concentrations in both sexes in a large population. RESEARCH DESIGN AND METHODS: The authors conducted a cross-sectional investigation of fasting serum concentrations of insulin and Lp(a), other blood tests, blood pressures, anthropological measurements, physical activity index, smoking habit, alcohol consumption, and menopause. The subjects were 1,121 men and 1,480 women, ranging between 30 and 90 years of age, who were voluntary participants in the Jichi Medical Cohort Study and who resided in one of five rural communities in Japan. RESULTS: In men, insulin, age, BMI, LDL cholesterol, triglycerides, glucose, and fibrinogen were significantly correlated with Lp(a). In women, insulin, age, LDL cholesterol, fibrinogen, and activated coagulation factor VII were significantly correlated with Lp(a). However, all correlations were weak in either sex. Insulin was inversely correlated with Lp(a) in both sexes. However, the coefficients were weak (r = -0.16 in mean and r = -0.06 in women). In the partial correlation analyses, Lp(a) was not significantly associated with insulin in either sex. The result was not influenced by selecting the subjects on the basis of detectable values of insulin and Lp(a) and stratifying them by serum glucose level. CONCLUSIONS: There was no significant relationship found between serum insulin and Lp(a) concentrations in either sex of the cohort, which indicates that Lp(a) does not play a role in the increased risk of cardiovascular disease in hyperinsulinemic subjects.

Assessment of regional sympathetic nerve activity in vasospastic angina: analysis of iodine 123-labeled metaiodobenzylguanidine scintigraphy.

With the use of iodine 123-labeled metaiodobenzylguanidine (123I-MIBG) scintigraphy, this study evaluated regional sympathetic nerve activity in vasospastic angina. Twenty male patients with left anterior descending coronary artery spasm and 18 male patients with normal coronary arteries as a control group were studied. All patients underwent quantitative 123I-MIBG scintigraphy and atropine stress 123I-MIBG scintigraphy. Both groups showed a similar heterogeneous 123I-MIBG uptake in the left ventricle. However, the regional washout rate in patients with coronary artery spasm was significantly reduced in all three territories compared with that in the control group. In vasospastic angina, the regional washout rate in the left anterior descending coronary artery territory was significantly reduced as compared with the other two regions. After intravenous injection of 1 mg atropine, the regional washout rate in the three regions significantly increased in both groups, but the regional differences between the two groups disappeared. The current study demonstrated that cardiac sympathetic nerve activity in vasospastic angina was suppressed, especially in the territory of the spasm-induced coronary artery, probably because of the enhanced parasympathetic nerve activity.

Characteristics of the insulin resistance syndrome in a Japanese population. The Jichi Medical School Cohort Study.

We investigated the relationships between hyperinsulinemia (a major indicator of the insulin resistance syndrome), blood pressure, dyslipidemia, and coagulation factors in 2606 community-dwelling Japanese individuals as part of the Jichi Medical School Cohort Study. An age-related decrease of the fasting insulin level was found in men but not in women. Body mass index, systolic and diastolic blood pressure, triglyceride and fasting glucose levels, and factor VII activity all increased in both sexes as the insulin level became higher, while the HDL cholesterol level decreased. In addition, total cholesterol and LDL cholesterol levels increased as the insulin level became higher and lipoprotein(a) levels decreased in the men. Fibrinogen levels were not related to the insulin level in either sex. Multiple logistic regression analysis revealed that fasting insulin levels were positively correlated with body mass index and fasting glucose and factor VII activity levels, whereas they were negatively correlated with HDL cholesterol in both sexes. In addition, fasting insulin levels were positively correlated with LDL cholesterol levels in men and with triglyceride levels in women. Our results indicate that hyperinsulinemia is associated with high factor VII activity in a general Japanese population as well as with high blood pressure and dyslipidemia. The accumulation of these cardiovascular risk factors in hyperinsulinemic subjects appears to contribute to cardiovascular events in the Japanese as well as in westerners.

Enlargement of multiple cavernous hemangioma of the liver in association with pregnancy.

Four cavernous hemangiomas were found in a 34-year-old woman after the first delivery. All four hemangiomas became enlarged after the second delivery. Due to complaints of symptoms of compression, and to rule out malignancy, surgical intervention was employed. Histologically, the tumors were typical cavernous hemangiomas. Although a relationship between enlargement of hemangiomas and estrogen was suggested, estrogen receptors were not detected in the tumors.

Assessment of the brain areas perfused by superselective intra-arterial chemotherapy using single photon emission computed tomography with technetium-99m-hexamethyl-propyleneamine oxime--technical note.

The brain areas perfused by superselective intra-arterial (i.a.) chemotherapy were assessed using single photon emission computed tomography (SPECT) with technetium-99m-hexamethyl-propyleneamine oxime (99mTc-HMPAO). A superselective catheter was introduced into the anterior, middle, or posterior cerebral artery of patients with malignant glioma for i.a. chemotherapy. 99mTc-HMPAO was subsequently injected via the same catheter used for chemotherapy, and a higher dose of 99mTc-HMPAO was injected intravenously to obtain adequate background brain images. Comparison of the SPECT images with magnetic resonance images could confirm complete perfusion of the tumor tissue. In two patients with malignant glioma, regions of interest were selected in the peritumoral brain area and a reference brain area, and the radioactivity was measured. The concentration of 99mTc-HMPAO was about 50 times higher in tissue perfused by superselective injection into anterior or middle cerebral artery compared to intravenous injection. 99mTc-HMPAO SPECT is readily available in many institutions and the information provided is useful for planning more effective and safe i.a. chemotherapy.

[Intra-arterial ACNU, CDDP chemotherapy for brain metastases from lung cancer: comparison of cases with and without intra-arterial mannitol infusion].

To assess whether therapeutic efficacy is related to intra-arterial (IA) mannitol infusion prior to ACNU and cisplatin (CDDP) for brain metastases from lung cancer, clinical results of patients with and without IA mannitol infusion were compared. Thirty-nine patients were randomly assigned to either a mannitol infusion group (group A) or a non-mannitol infusion group (group B). There were 22 patients in group A and 17 in group B. During radiotherapy, ACNU and CDDP, at a dose of 100 mg/body, were given through the common carotid artery at a rate of 20 mg/min. In group A, 50 ml of 20% mannitol was injected intra-arterially at a rate of 50 ml/min immediately prior to the injection of chemotherapeutic agents. Major complications, such as seizure and neurotoxicity, were not observed. Complete response (disappearance of enhanced tumor mass) was obtained in 72% of group A and in 67% of group B. The median time to tumor progression was 40 weeks for group A and 22 weeks for group B. The median survival time (MST) was 45 weeks for group A and 30 weeks for group B. The survival time was significantly longer in group A as compared to group B (p < 0.05). When the patients who died of failure of vital organ systems other than brain complications were excluded in calculating the survival time, the MST was 69 weeks for 11 patients of group A and 34 weeks for 7 patients of group B. These data suggest that an effort to increase drug delivery to the brain tumor may indeed lengthen the survival time of patients with brain metastases from lung cancer.

Intra-arterial mannitol infusion in the chemotherapy for malignant brain tumors.

To assess whether therapeutic efficacy is related to the intra-arterial (IA) mannitol infusion prior to ACNU and cisplatin (CDDP) for malignant brain tumors, the survival time of patients with and without mannitol infusion was compared. Ninety-eight patients were randomly assigned to either a mannitol infusion group (group A) or a non-mannitol infusion group (group B); 34 with malignant gliomas (18 in group A and 16 in group B) and 64 with brain metastases (36 in group A and 28 in group B). During radiotherapy, ACNU and CDDP at a dose of 100 mg/body were given through the common carotid artery at a rate of 20 mg/min. In group A, 50 ml of 20% mannitol was injected intra-arterially at a rate of 50 ml/min immediately prior to the injection of chemotherapeutic agents. Of the patients with malignant gliomas, the median survival time (MST) was 52 weeks for all 34 cases, 68 weeks for group A, and 47 weeks for group B. Survival analysis showed no significant differences between the two treatment groups. Of the patients with brain metastases, the MST was 40 weeks for all 64 cases, 47 weeks for group A, and 24 weeks for group B; the survival time was significantly longer in group A as compared to group B (p < 0.05). This study has demonstrated that, for the patients with brain metastases, IA mannitol infusion provided a survival benefit in the IA chemotherapy employing ACNU and CDDP. In contrast, IA mannitol infusion offered no survival benefit to the patients with malignant gliomas.

[Effect of sex hormones on the onset of diabetic syndrome in WBN/Kob rats].

The effects of sex hormone on diabetic conditions were investigated in WBN/Kob strain rats, i.e., castrated or spayed, hormone-treated, and non-treated rats. The effects of sex hormone on glycosuria, body-weight change, glucose tolerance and histopathology of the pancreas were compared among these animals. There were no abnormal changes in these parameters in the non-treated females and estrogen-treated males. The glycosuria began to be observed from the age of about 30 weeks in the non-treated group and from the age of 52 weeks in the castrated group. In the female animals, this symptom began to appear from the age of 55 weeks in the testosterone-treated group and from the age of 72 weeks in the spayed group. Before the onset of the diabetic symptoms, glucose tolerance was impaired in these animals. Body weights of the castrated and estrogen-treated males were lower than that of the non-treated males, especially in the estrogen-treated males. Those of the spayed and testosterone-treated females were much heavier than that of the non-treated females. Testosterone treatment accelerated body-weight gain in the spayed female animals. Histopathological examination of the pancreas revealed atrophy of the aciner tissue and atrophy and disappearance of the islet cells similar to those of the non-treated WBN/Kob male rats in the castrated males, spayed females and testosterone-treated females. However, these changes were not observed in the non-treated females or estrogen-treated males. These findings suggest that female hormone suppressed the onset of hyperglycemia along with glycosuria and male hormone accelerates the onset of hyperglycemia in the WBN/Kob rats.

Isolation of the avian transforming retrovirus, AS42, carrying the v-maf oncogene and initial characterization of its gene product.

A novel avian transforming retrovirus was isolated from a chicken musculoaponeurotic fibrosarcoma. This virus (called AS42) induces tumors histopathologically indistinguishable from the original sarcoma after a long latent period when inoculated into newborn chickens. AS42 also exhibits a weak transforming activity when infected into chicken embryo fibroblasts (CEF). This virus is replication-defective and associated with a helper virus of subgroup A (called ASAV). An AS42-specific protein of about 100 kDa was immunoprecipitated from lysates of AS42-transformed CEF with antiserum directed against avian retrovirus virion proteins. Molecular analysis of the genomic structure of the AS42 virus has revealed that this 100-kDa protein represents a novel oncogene, v-maf of cellular origin, which is fused with a part of the viral gag gene (Nishizawa et al., Proc. Natl. Acad. Sci. USA 86, 7711-7715, 1989). Interestingly, some size variation was observed among the gag-maf fusion proteins found in individual clones of transformed CEF. Consistent with this observation, Southern blot analyses and nucleotide sequence determination of several independent isolates of proviral DNA indicated that this virus segregates multiple forms of deletion mutants, probably through homologous recombinations among the repetitive sequences present within the v-maf coding region.

Glycogen accumulation in the renal tubular cells of spontaneously occurring diabetic WBN/Kob rats.

Cytoplasmic and nuclear accumulation of glycogen granules in the kidney cells of 72 male WBN/Kob rats with a long-term diabetic condition was studied histologically and by electron microscopy. The incidence and degree of the accumulation showed good correlation with the blood glucose concentration. In the kidneys, there was evidence of two types of lesion, cytoplasmic glycogen accumulation in the distal convoluted tubules and nuclear accumulation in the ascending thick segment of Henle's loops. Electron microscopically, the cytoplasmic glycogen accumulation was often associated with an increased number of lysosomal bodies containing lamellar bodies. Glycogen bodies, the halo of which was thought to be identical with that of nuclear bodies, were frequently observed in the nuclei containing the glycogen granules. These morphological and topographical differences between the two types of lesion were considered suggestive of different pathogenetic mechanisms for glycogen accumulation in the kidney cells.

Computed tomography and magnetic resonance imaging of nonhemorrhagic, metastatic melanoma of the brain--case report.

Malignant melanoma frequently metastasizes to the central nervous system. Characteristic features of such lesions are increased density on computed tomography (CT) and shortening of the T1 and T2 on magnetic resonance (MR) imaging. Intratumoral hemorrhage, rather than melanin, is considered to be mainly responsible for these unique radiological features. The authors report a case involving a nonhemorrhagic, metastatic intracerebral melanoma. CT revealed a high-density mass, and MR imaging demonstrated a hyperintense mass both on T1- and T2-weighted images. These observations suggest that melanin is in fact a major determinant of the increased density on CT scans and the high signal intensity on T1-weighted MR images. On T2-weighted images, the paramagnetic effect appears to vary according to the melanin content.

[Effect of gonadectomy on the onset of diabetic syndrome in the female WBN/Kob rats].

Almost all the male animals of WBN/Kob rat strain show the diabetic syndrome whereas none of the female animals develop such diseased conditions even at elder age. We investigated the effect of sex hormones on the onset of diabetic syndrome of this rat strain by comparing the results of body weight gain and various clinical tests such as glucose tolerance, serum biochemistry and histopathology of spayed female rats with those of non-treated and sham-operated female animals kept until 88-week-old. Non-treated and sham-operated female animals had shown no abnormal result even at 88-week-old. Spayed female animals began to reveal glucosuria associated with polydipsia and polyuria from 72-week-old, and gradually developed emaciation and cataract. Increased body weight gain, impaired glucose tolerance and lasting hyperglycemia were observed prior to the onset of the symptoms. Pancreatic changes consisted of atrophy of acinar tissue and atrophy or disappearance of islet tissue attributable to clinical data also were detected in spayed female animals. These diabetic syndrome and pancreatic change were analogous to those of aged male WBN/Kob rats but the onset of spayed females was delayed and less severe. Present results suggest that female sex hormones are protective from the onset of diabetic syndrome of WBN/Kob rats.

[Retinal degeneration in the WBN/Kob rat].

Spontaneous, retinal degeneration in the WBN/Kob rat, a new diabetic strain, was examined by behavior pattern, electroretinogram (ERG) and histopathology. Histopathological evidence of retinal degeneration was first detected at about 30 weeks of age in male and female rats. The earliest change in the retina was loss of rads and cones, and the inner layer was gradually involved. The retina showed marked atrophy in the thinned inner plexiform layer and a decreased number of ganglionic cells by 90 weeks. Severe retinal change was observed in almost all rats over 90 weeks old. Prior to the onset of histological change, the ERG showed prominent change. Amplitude of a- and b-waves began to be reduced at 17 weeks and was non-recordable at 32 weeks. This retinal abnormality was thought to be hereditary, but further investigation is needed to clarify the relationship between the genetic background of this change and diabetes.

Serum testosterone, testicular connective tissue protein and testicular histology in rats treated with hyperbaric oxygen.

This study was done to ascertain whether hyperbaric oxygenation really affects testicular activity in rats. We evaluated serum testosterone concentration, testicular content of connective tissue protein and histological analysis of testes in each rat treated with 2 or 3 atmospheric pressures associated with oxygen saturation, together or singly for 90 minutes daily for 58 days. There were no significant differences in serum testosterone concentrations between the examined groups. The amounts of collagen, non-collagenous protein or elastin in testis were similar in all groups except one set of determinations. In addition, no prominent histological differences were noted in the testes of the animals. Thus, the pressure environment of this study, which can be regarded as almost the same as that of the hyperbaric oxygenation chamber in clinical use, appears to be nontoxic to rat testes.

A new diabetic strain of rat (WBN/Kob).

A new, spontaneously occurring diabetic syndrome has been observed in the aged males of an inbred strain of Wistar rats, WBN/Kob. The main clinical sign, glycosuria, was first detected at about 60 weeks of age, and thereafter some animals developed hyperlipidaemia and gradual emaciation. Prior to the onset of glucosuria, male rats showed impaired glucose tolerance after a glucose load at 21 weeks of age. The histopathologic lesions of the pancreas in the diabetic males consisted of multifocal fibrosis, decreased in number and size of islets and atrophy of exocrine tissue. Multifocal inflammatory foci of varying stages were the main pancreatic lesion in prediabetic male rats. This inflammatory change was detected even in 12-week-old rats and tended to occur around the islets. Therefore focal fibrosis and the decrease in the number and size of islets were considered to result from post-inflammatory scarring. The maturity-onset of this syndrome and the impaired glucose tolerance in younger animals suggested that diabetes mellitus of this rat strain is insulin-independent type II. However, the histological lesions of the pancreas were somewhat different from previous reports of both type I and II diabetes mellitus in man and animals.

[A simplified method for detection of visual abnormality in rats on reproduction study: the critical intensity of illumination and the effect of dark-adaptation].

A newly designed Y-shaped box was previously reported by authors to be useful for a screening test of visual abnormality in rats because of easy numerization and statistical analysis of the results. In the present paper, the relationship between the intensity of illumination and the negative phototaxic response were examined. The total selection rate for the dark area (total time of selecting dark area/total trials) of non-treated rats under 30 lux illumination was 98% and identical wit the result of those under 1600 lux. The selecting rates of non-treated rats under the illumination of 15, 10, 7.5, 5 and 1.25 lux were 95, 93, 89, 82 and 67%, respectively. On the other hand those of dark-adapted rats one hour under 15, 7.5 and 5 lux showed 98, 95 and 92%, respectively. From these results, the critical intensities of illumination-unaffected selection rate for darkness in non-treated and dark-adapted rats were estimated at 30 and 15 lux, respectively. There was an obvious effect of dark-adaptation on the visual ability of rats. The selection rate of eyelid-sutured rats under 30 lux was 52%, an approximate theoretical value of true blindness, but it was 85% under 1600 lux. It is suggested that a more exact detection of visual abnormality would be possible under the critical intensity of illumination-unaffected selection rate for darkness.

[A simplified method for detection of visual abnormality in the rat in a reproduction study (author's transl)].

A Y-shaped test box was designed for the screening of visual abnormality using negative phototaxis in normal rats. Its availability was determined by examination of 100 animals belonging to non-treated, eyelids-sutured, and eyeballs-enucleated groups. Two kinds of examination were undertaken, the first being observation of the general behavior of the animals in the box for one minute. The second was 4 trials at selection of the dark area of the box given to each animal. In each examination many animals could be tested in a short time. The behavioral pattern of the eyelids-sutured and the eyeballs-enucleated groups was significantly different from that of the non-treated group. The selection rate for darkness by non-treated, eyelids-sutured and enucleated groups in the second examination was 97.5%, 84.5, and 50.0 percent, respectively. Therefore successful estimation could be possible by both procedures and it was possible to numerize the gained value and analyze statistically in the second examination. It was concluded that this simplified method for testing visual function should prove very useful as a behavioral teratology screening test in routine reproduction studies.

The influence of hyperbaric oxygenation on rat testes.

Using Wistar stain male rats, it has been shown that 2 atmospheric pressures associated with oxygen saturation, together or singly for 90 minutes daily for successive 46 days, resulted in no significant change on the ratio of testes to body weight. No significant change was observed in the incorporation of 3H-thymidine into testes and pituitary glands between the pressure-treated groups and the control group.