Influence of aortic impedance on the development of pressure-overload left ventricular hypertrophy in rats

BACKGROUND

Aortic input impedance, which represents LV afterload, is considered to be a major determinant for the development of pressure-overload left ventricular (LV) hypertrophy.

METHODS AND RESULTS

To test whether the sustained change in aortic input impedance might affect the mode of development of LV hypertrophy, coarctation of either the ascending aorta (G1, n = 13) or suprarenal abdominal aorta (G2, n = 12) was performed over 4 weeks in 6-weeks-old Wistar rats. Although peak LV pressure and total systemic resistance were increased similarly in G1 and G2, time to peak LV pressure was decreased by 24% (P < .01) in G1 compared with G2. The aortic input impedance spectra revealed that the early systolic loading in G1 was characterized by an increase in characteristic impedance, whereas the late systolic loading in G2 was by an augmented arterial wave reflection. G1 showed a smaller increase (P < .01) in either the ratio of LV weight (mg) to body weight (g) or LV wall thickness than G2 after aortic banding. Myocyte diameter was also smaller (P < .05) in G1 (14.3 +/- 0.7 mm) than in G2 (16.1 +/- 1.2 mm). The ex vivo passive pressure-volume relation had a rightward shift in G1 compared with G2, suggesting less concentric LV hypertrophy in G1.

CONCLUSIONS

The sustained early systolic loading due to the increase in characteristic impedance was accompanied by less concentric, reduced hypertrophy, whereas the sustained late systolic loading due to the augmented arterial wave reflection was accompanied by concentric, adequate hypertrophy.

Effect of bucillamine on the rat trinitrobenzene sulfonic acid induced model of colitis

Salicylazosulphapyridine and corticosteroids are the only remedies for inflammatory bowel disease currently in clinical use. They do not, however, necessarily bring about satisfactory therapeutic benefits, so that new agents are needed. In this study, we evaluated the effect of bucillamine, a new antirheumatic agent, in experimental rat colitis induced by trinitrobenzene sulfonic acid enema. Wistar rats were given vehicle alone (n = 16) or treated with 50 (n = 20) or 150 (n = 20) mg/kg of bucillamine daily for three weeks after induction of colitis. Conventional histological sections of the colon stained by haematoxylin and eosin were prepared and observed under a light microscope to determine colonic damage scores. The determinations were significantly lower in the group treated with 50 mg/kg of bucillamine and tended to be lower in the group treated with 150 mg/kg of bucillamine than in the untreated group, which implied that the experimentally induced colonic inflammatory changes and ulcerations were alleviated by bucillamine. Blood tests showed no abnormal values at the end of the treatment. The present observations suggest that bucillamine should be developed further as a possible therapy for inflammatory bowel disease.

Distribution and anti-inflammatory effect of mesalazine on carrageenan-induced colitis in the rabbit

1. A controlled-release preparation of mesalazine microgranules (PentasaR; Ferring AS, Vanlose, Denmark) releases the active ingredient over a wide area from the small intestine to the rectum and is consequently expected to bring about therapeutic benefits to patients with ulcerative colitis and Crohn's disease. 2. Mesalazine microgranules (50 or 150 mg/kg per day) were administered orally to each rabbit with carrageenan-induced colitis for six weeks. Its inhibitory effect on colonic mucosal damage was assessed in terms of the microscopic damage scores, leukotriene B4 concentrations and concentrations of mesalazine derivatives. 3. At the end of the experiment, the mesalazine 150 mg group had gained a significantly greater bodyweight than the control group. Microscopic damage was significantly lower in the 150 mg group than in the untreated control group. Tissue concentrations of 5-aminosalicylic acid and acetyl-5-amino-salicylic acid in the small and large intestine were higher in the 150 mg group than in the 50 mg group. Mucosal leukotriene B4 levels tended to be lower in rabbits receiving the larger dose of mesalazine. 4. The present study indicates that slow release 5-amino-salicylic acid at the larger dose reaches the large bowel in sufficiently high concentrations following oral administration and significantly reduces carrageenan-induced colitis in the rabbit.

Deficiency of blood coagulation factor XIII in Crohn's disease

OBJECTIVE

Refractory fistula formation is one of most intractable complications in Crohn's disease. Recently, the role of blood coagulation Factor XIII has been recognized as an important wound-healing factor. We investigated the plasma concentration and functional activity of blood coagulation Factor XIIIa, active subunit of the Factor XIII, in patients with Crohn's disease and in healthy volunteers.

METHODS

Peripheral blood was obtained from 24 patients with Crohn's disease and from 10 healthy volunteers. The functional activity of Factor XIIIa was measured by its transglutaminase activity, and plasma concentration was measured by the immunoelectrophoresis method.

RESULTS

The differences in Crohn's disease patients and healthy volunteers were not significant. However, Crohn's disease patients with fistula had significantly lower functional activity than Crohn's disease patients without fistula.

CONCLUSIONS

The deficiency in this wound-healing factor might be one reason for refractory fistulas in Crohn's disease, and supplementation of the factor might be useful therapeutically.

[Localization of salazopyrin in colonic mucosa patients with ulcerative colitis]

In this study SASP metabolite levels were measured in colonic mucosal specimens and plasma samples from 31 patients with ulcerative colitis (UC) under treatment with the drug. Colonic tissue specimens were obtained by endoscopically guided biopsy and plasma was isolated from peripheral blood. Measurements were performed by HPLC according to the procedure of Fischer et al. The levels of 5-ASA and SP in either of colonic tissue or plasma were significantly lower than those of Ac-5-ASA and Ac-SP, respectively. The tissue level of 5-ASA had a significant correlation to the dosage of 5-ASA. The tissue levels of 5-ASA and Ac-5-ASA were low in an active stage of UC than during a remission period and the difference observed with respect to the latter metabolite was significant. These findings suggest that acetylation of 5-ASA is inhibited in the colonic mucosa in an active stage of the disease.

[Antiinflammatory effects of the betamethasone sodium phosphate enema on carrageenan induced colitis in the rabbit]

The effect of the betamethasone sodium phosphate (BSP) enema on the colonic mucosal lesions in the carrageenan induced colitis (rabbit) was examined laboratory and histologically. The effect of drugs were evaluated by the changes of body weight, fecal occult blood, blood analysis, and histological examinations. Fecal occult blood were highly positive in the physiological saline treated but less positive in the BSP groups. In the blood analysis, anemia was not detected in both groups. Histological findings such as the defect of superficial epithelium, crypt abscess, inflammatory cell infiltration, atrophic changes, defect of muscularis mucosae, goblet cell depletion, goblet cell depletion, ulcer formation, and edematous change were scored to evaluate the colonic mucosal lesions. These scores (Mean +/- S.D.) were 4.4 +/- 1.96, 7.7 +/- 3.67 for BSP, physiological saline groups respectively. From these results, BSP enema showed an antiulcerative effect on the entire colonic lesions in the carrageenan induced colitis in the rabbit.

[A case of subfrontal schwannoma]

We encountered a rare case of subfrontal schwannoma. A 55-year-old woman had received resection of a left frontal tumor because of hyposmia, at the age of 28 years. On June 10, 1989, she was admitted with the chief complaint of progressive contraction of visual field. Neurologic examination revealed anosmia, impaired vision and concentric contraction of visual field. Fundoscopy showed optic atrophy. CT examination demonstrated a calcified mass of mixed density which was occupying her nasal cavity, ethmoid sinus and anterior skull base. The lesion was enhanced with contrast medium. MRI clearly depicted the extension of the lesion and a low signal intensity area in the left frontal lobe as a postoperative scar. Angiography showed hypovascularity. The tumor was totally removed by bifrontal craniotomy on August 22, 1989. Infiltration into the brain or compression of the optic nerve was not detected. The dura on the cranial base side was damaged and lost by infiltration of the tumor, normal olfactory bulb was not able to be identified, and the cribriform plate was broken. The anterior skull base was reconstituted by covering the dural defect with cadaveric dura and the bony defect with a pericranium. HE staining showed Antoni A&B types of schwannoma. Postoperative course was uneventful. In this case, it is most likely that a remnant of the tumor resected when she was 28 years old had developed subfrontal schwannoma a long time after the operation, although the histological type at that time was unknown. It is also possible that a primary tumor in the nasal cavity or paranasal sinus may have extended into the cranium.(ABSTRACT TRUNCATED AT 250 WORDS)

Polyamine metabolism in colonic mucosa from patients with ulcerative colitis

Polyamine metabolism in mucosa both from patients in the active or remission stage of ulcerative colitis (UC) and from healthy controls was studied. In the active stage of UC, mucosal spermidine concentration was higher than in remission or in the controls, but the activities of ornithine decarboxylase and S-adenosylmethionine decarboxylase, rate-limiting enzymes of polyamine biosynthesis, were lower. In the active stage of UC, the mucosal level of mRNA coding for ornithine decarboxylase was lower than in the remission stage of UC or in the controls. The activity of spermidine/spermine N1-acetyltransferase, the rate-limiting enzyme of polyamine degradation, was higher in the active stage of UC than in the remission stage of UC or in the controls. However, it seemed that this activity did not reflect the increase in the spermidine concentration. The results showed that the spermidine increase in the active stage of UC was not due to changes in the synthesis or degradation of polyamines; the increase may have been due to increased exogenous spermidine uptake.

Posttranslational regulation of spermidine/spermine N1-acetyltransferase with stress

The effect of stress on the activity and level of mRNA of spermidine/spermine N1-acetyltransferase (SAT), a polyamine degradation rate-limiting enzyme, was studied in Ehrlich ascites tumor cells. When the cells were treated with sodium arsenite or ethanol for 1 h at 37 degrees C, the activity of SAT increased time- and dose-dependently. Total RNA was isolated from cells treated with stress, and the relative abundance of the SAT mRNA was measured by Northern blot analysis. The amount was comparable to those in control cells. In stress-treated cells, the biological half-life of the enzyme was 48-55 min, but 27-30 min in control cells. When cells were treated with arsenite in the presence of cycloheximide, enzyme activity did not increase. In those cells, half-life of the enzyme was shorter than in the cells treated with arsenite alone. This suggests that stress-treatment of cells enhanced SAT activity posttranslationally and that some factor(s) which was synthesized de novo during the treatment of arsenite is involved in the stabilization of the enzyme.

Enhancement of spermidine/spermine N1-acetyltransferase activity by treatment with lithium chloride in Ehrlich ascites tumor cells

The activity of spermidine/spermine N1-acetyltransferase (SAT) was enhanced in Ehrlich ascites tumor cells by the addition of lithium chloride. Na+ did not affect the enzyme activity. Total RNA was isolated from cells treated with LiCl and the relative abundance of the SAT mRNA was measured by Northern blot analysis. The levels in cells treated with LiCl were comparable to those in control cells. In the treated cells, the biological half-life of SAT was approximately 20 min, which was the same as for control cells. When LiCl and H-7, a protein kinase inhibitor, were added simultaneously to culture, the elevation caused by LiCl of SAT activity was reduced. LiCl did not cause maximum enhancement of the enzyme in cells treated beforehand with a higher concentration of TPA. These results suggest that treatment of Ehrlich ascites tumor cells with LiCl enhanced SAT activity during translation, not during transcription or after translation and that the enhancement of SAT by LiCl is probably mediated by protein kinase C.

Induction of irreversible glomerulosclerosis in the rat by repeated injections of a monoclonal anti-Thy-1.1 antibody

The present experiment demonstrated that an irreversible glomerulosclerosis could be induced in the rat through repeated intravenous administrations of OX-7 (a monoclonal anti-Thy-1.1 antibody). Rats were injected with 0.2 mg of affinity-purified OX-7 at 1-week intervals for a period of 4 weeks. Glomerular damage was periodically examined at light-microscopic level. Thirty-five days after the initial injection (7 days after the final injection), capillary aneurysms and expansion of the mesangial areas with hypercellularity were frequently observed. Similar glomerular damage was also observed in rats 7 days after they received a single injection of either 1.0 or 0.2 mg of OX-7. After repeated injections, 112 days from the initial administration (84 days after the final injection), approximately 60% of the glomeruli had expanded mesangial areas with an apparent increase in the mesangial matrix. The result contrasts sharply with that obtained from a single injection of OX-7 in that more than 85% of the glomeruli showed no abnormalities 84 days after the injection. This chronic model, as a result of repeated injections of the antibody, could serve as a potential for further investigation of the mechanisms involved in the development of chronic glomerulonephritis.

[Medical students' images of the occupational health physician--on the evaluation of motivation in medical education]

One of the aims of the University of Occupational and Environmental Health, Japan, is to educate students to become occupational health physicians. However, the number of students who enter the university without an understanding of this aim is large. Therefore, the course titled 'Introductory Lectures on Occupational and Environmental Health' was planned for the 2nd-year students with the purpose of giving them the motivation to become occupational health physicians. Surveys of students' images of the term "occupational health physician" before and after taking the course were accomplished using the method of 'Monju card', that is, three students, in turn, write their ideas of an occupational health physician on a card. Moreover, after the series of lectures, students were assigned a self-evaluation regarding the improvement of their images. The results of these surveys show that favorable images increased after the course, that classes offering information regarding the occupational health physician had an influence on the improvement of the images, and that students desire more such information. However, as some students indicated a strong rejection to becoming occupational health physicians throughout the course, a different type of course, and a new philosophy regarding the training of medical students may be necessary.

Acute megakaryoblastic leukemia in Down syndrome, following thrombocytopenia with antiplatelet antibody

We report a case of acute megakaryoblastic leukemia (AMKL) with antiplatelet antibody in a boy with Down syndrome. When the patient was admitted, his platelet count was 1.3 X 10(4)/mm3 and antiplatelet antibody in the plasma was detected. Two months after admission, blasts, which showed positive reaction to both antiplatelet monoclonal antibody and platelet peroxidase, increased.

Cortical blindness caused by acute general cerebral swelling

A 7-year-old girl who suffered from acute general cerebral swelling as a result of a traffic accident showed cortical blindness. Computed tomography (CT) scan on admission revealed marked slitlike ventricles and narrowing of the perimesencephalic cisterns, which indicated general cerebral swelling. While hospitalized, the patient developed transtentorial herniation twice on day 3, and CT scans at herniation episodes showed disappearance of the perimesencephalic cisterns. After recovery of consciousness, the patient showed cortical blindness, and during gradual recovery she showed pure alexia without agraphia. The visual evoked potentials at 8 weeks, 16 weeks, and 3 years 4 months after trauma showed normalization of the pattern, but revealed left occipital inactivity.

[Basis of bioethics--bioethics in Japan and the United States]

During the past ten years bioethics has gradually become an important subject for discussion in Japan. However these discussions are quite different from those in the United States where bioethics has been a major field of study for some time. The purpose of this paper is to show the differences between the Japanese and American ideas regarding bioethics by studying the social environment in the United States. When compared to Japan, there is a great difference in this environment and the American views on ethics. Japanese studying bioethical problems should study them by first comparing the points of differences stated in this paper and then applying their conclusions to the bioethical problems here in Japan.