Macrophage function in the acute phase of lactic dehydrogenase virus-infection of mice: suppression of superoxide anion production in normal mouse peritoneal macrophages by interferon-alpha in vitro

The effect of interferon (IFN)-alpha on the release of superoxide anions (O2-) by normal mouse macrophages (PEM) was examined. Sera from LDV-infected mice at 1 day, but not at 7 days post-infection, suppressed the O2- release by PEM. When PEM were exposed in vitro for 24 h to IFN-alpha, their capacity to release O2- was significantly suppressed. Progressive suppression of O2- release with increasing IFN-alpha concentration was observed. These results suggest that IFN-alpha in the circulation may be one of several suppressive factors on macrophage function in the early phase of infection and IFN-alpha may play a modulatory role in inflammation and immunity.

Production of hydroxyl radicals and their disassociation from myocardial cell injury during calcium paradox

The production of hydroxyl radicals during calcium paradox injury was investigated by measuring the production of 2,5-dihydroxybenzoic acid (2,5-DHBA) from salicylate. Four groups of rats were analyzed. In the first group, isolated hearts were perfused with calcium-free medium for 10 minutes followed by perfusion with medium containing Ca++ for 10 minutes. In the other groups, 0.25 microM N,N'-diphenyl-1,3-phenylenediamine (DPPD), 80 microM cytochrome c, or 450 U/ml catalase was added. Coronary effluent was analyzed for the presence of 2,5-DHBA, and tissue sections were examined using light microscopy. In the first group, 2,5-DHBA production began during the calcium-free period, peaked tenfold 60-90 sec. into the Ca repletion period, and declined thereafter. The increase in 2,5-DHBA was accompanied by severe cell damage. Cytochrome c reduced 2,5-DHBA production, and catalase almost completely inhibited 2,5-DHBA production, while DPPD had no effect on 2,5-DHBA production. None of the three additives provided any complete morphological protection. The data provide evidence for the production of hydroxyl radicals during calcium-paradox injury, that their production is dependent upon the presence of hydrogen peroxide, and that cell damage in the calcium paradox is not primarily mediated by the extracellular hydroxyl radicals.

Increased superoxide anion release by peritoneal macrophages in mice with a chronic infection of lactic dehydrogenase virus

The function of macrophages in mice chronically infected by lactic dehydrogenase virus (LDV) was studied. Superoxide anion (O2-) release was examined by using peritoneal macrophages. O2- release increased markedly from 3 weeks to 12 months, but not at 1 week post infection. O2- release was 1.2 to 1.5 times greater than in uninfected mice. Increased O2- release from macrophages in LDV-infected mice may explain, at least in part, suppressive effects on tumour growth seen in the chronic phase of infection.

Thymic atrophy in type 2 reovirus infected mice: immunosuppression and effects of thymic hormone. Thymic atrophy caused by reo-2

Suckling mice infected with reovirus type 2 showed a thymic atrophy followed by a marked suppression of the antibody, production to SRBC (a T cell dependent antigen) and bacterial LPS, when measured by the splenic PFC assay. The PFCs produced were sometimes less than 1% of uninfected control animals. Histologically the thymus was usually smaller than normal, and atrophy of the cortex and increased number of Hassal's bodies were observed. Number of nucleated cells in the thymus of infected mice showed 90% decrease as compared to uninfected mice. The spleen, although larger in size, showed depletion of lymphocytes from the thymus-dependent and follicular areas. No viral replication was detected in lymphatic organs using virological methods. Virus-infected mice transferred with the splenocytes or thymocytes from age-matched uninfected mice restored the antibody production against SRBC to normal levels. Thymocytes were more efficient than splenocytes in enhancing the antibody production in virus-infected mice. Injection of several different kinds of immunopotentiating agents enhanced the antibody production to SRBC, although LPS exacerbated the unresponsiveness. Thymic hormones such as FTS and TP5 enhanced antibody production to SRBC and LPS more efficiently than MDP. Flow cytometric analysis showed that percentage of CD4+ single positive cells was slightly increased in virus-infected mice treated with FTS, while there was no difference in the phenotypic distributions of thymocyte subpopulations among virus-infected mice, FTS-untreated and FTS-treated normal mice.

Anti-tumor effect of L-methionine-deprived total parenteral nutrition with 5-fluorouracil administration on Yoshida sarcoma-bearing rats

L-methionine-deprived total parenteral nutrition (methionine-deprived TPN), infusing amino acid solution devoid of L-methionine and L-cysteine by the method of TPN as an only protein source, showed enhancement of the effect of several anti-cancer agents. In this study the combined effect of the methionine-deprived TPN with administration of 5-fluorouracil (5-FU) was examined in Yoshida Sarcoma (YS)-bearing rats, from aspects of effects on the tumor metastasis and the host animal's life span, in the following four groups treated with: methionine-deprived TPN with administration of 5-FU, methionine-deprived TPN without administration of 5-FU, L-methionine-contained TPN plus 5-FU, and L-methionine-contained TPN without 5-FU. In the first experiment, TPN was continued for 8 days in the four groups, and the anti-cancer effect of methionine-deprived TPN and administration of 5-FU based on both the growth of the primary tumor at the implanted site and the tumor metastasis was studied from the view point of pathologic findings of animals killed immediately after these treatments. In experiment 2 the survival period was examined after these treatments for 10 days with subsequent oral feeding until death. The results were as follows: proliferation of YS, transplanted subcutaneously, was markedly suppressed; particularly hematogenous metastasis, characteristic in YS, was prominently blunted then obtained an apparent longer survival period in rats treated with the methionine-deprived TPN with administration of 5-FU.

Inhibition of contact sensitivity by interferon in mice infected with lactic dehydrogenase virus

The effect of acute lactic dehydrogenase virus (LDV) infection was studied with respect to contact sensitivity (CS) to 2,4-dinitrofluorobenzene (DNFB). CS reaction was severely inhibited in the acute phase but not in the chronic phase of infection. The role of interferon (IFN) was studied to understand further the inhibition of CS during LDV infection. IFN in the blood was detected only in the acute phase, but not in the chronic phase of infection. When anti-IFN (alpha/beta) was administered to infected mice, no inhibition of CS was seen. CS was inhibited in uninfected mice treated with IFN (alpha/beta). These results suggest that IFN production in the blood may be responsible, at least in part, for inhibition of CS observed in the acute phase of LDV infection.

Reperfusion injury in dog hearts with permanent occlusion of a coronary artery, probably due to reperfusion via collateral vessels

To clarify whether or not reperfusion injury occurs in the permanent occlusion of a coronary artery, we analyzed quantitatively contraction band necrosis as an indicator of early recanalization, coagulation necrosis, infarct size and measured regional blood flow in dog hearts with collateral circulation. Fifty mongrel dogs were divided into four groups: 15 dogs with a 24-hour occlusion of the left anterior descending coronary artery just distal to the first diagonal branch (permanent occlusion group): 15 dogs a with 3-hour occlusion followed by 24-hour recanalization (recanalization group); 10 dogs with a 2-hour occlusion without recanalization (transient occlusion group); 10 dogs with a 4-hour occlusion without recanalization (transient occlusion group). The regional blood flow in the subepicardium and subendocardium determined by the generated hydrogen gas clearance method was greatly decreased 30 minutes after occlusion (14 + 8%/12 +/- 9%) and was relatively restored from 180 minutes (31 +/- 21%/21 +/- 14%) to 24 hours later (41 + 19%/26 + 16%) in spite of complete occlusion of the coronary artery. The percentage infarct area in the risk area was significantly greater in the permanent occlusion group (60 +/- 26%) than in the recanalization group (35 +/- 31%). Although most of the infarct was occupied by contraction band necrosis in the recanalization group (86 +/- 12%), contraction band necrosis was diffusely seen even in the permanent occlusion group (54 +/- 27%). In both the permanent and recanalization groups, contraction band necrosis was the main histological feature of small infarcts occupying less than 30% of the risk area, while coagulation necrosis was the main feature in very large infarcts occupying more than 80% of the risk area. In the occlusion groups without recanalization, the percentage area of contraction band necrosis in the risk area was 6 +/- 8% after the 2-hour occlusion, 23 +/- 17% after the 4-hour occlusion and 31 +/- 21% after permanent occlusion; the difference between the 4-hour and permanent occlusion groups was not significant. In the permanent occlusion group, the percentage infarct area in the risk area was inversely correlated with regional blood flow during occlusion, an indicator of collateral flow. It was concluded that reperfusion injury occurs even in hearts without recanalization. The pathogenesis may involve reperfusion in the risk area via collateral circulation. Protection against reperfusion injury is important to minimize the infarct size even in hearts with permanent occlusion, although the presence of collateral flow is an important factor in limiting infarct size.

Detection of hydroxyl radicals in the post-ischemic reperfused heart using salicylate as a trapping agent

The formation of hydroxyl radical in the post-ischemic reperfused heart was measured with high performance liquid chromatography and ultraviolet detection using salicylic acid. Hydroxyl radicals react with salicylic acid yielding 2,3- and 2,5-dihydroxybenzoic acid, which can be separated by the liquid chromatography. Isolated rat hearts were perfused with 1 mM salicylic acid and were subjected to 30 mins of global ischemia followed by aerobic or anaerobic reperfusion at 37 degrees C. The effluent from the hearts was collected at various intervals, extracted with ether, and injected into the high performance liquid chromatography unit. 2,5-dihydroxybenzoic acid was present only after aerobic reperfusion and was not detected before ischemia. The liquid chromatography peak of 2,3-dihydroxybenzoic acid was too small for quantitation. The concentration of 2,5-dihydroxybenzoic acid was the highest within 300 s of reperfusion. 2,5-dihydroxybenzoic acid was not detected in the ischemic hearts during anaerobic reperfusion. In ischemic hearts perfused with mannitol, the amount of 2,5-dihydroxybenzoic acid after reperfusion was reduced. These data suggest that hydroxyl radicals are produced in the post-ischemic reperfused heart and that the present method is useful and reliable for the measurement of hydroxyl radicals in the heart.

Hepatotoxicity of DR-3438, tienilic acid, indacrinone and furosemide studied in vitro

A new diuretic antihypertensive, DR-3438, and marketed diuretic drugs were evaluated for their toxicity in vitro. Hepatocytes were isolated from male rats by the collagenase perfusion method and incubated in Dulbecco's modified Eagle medium containing various doses of DR-3438, tienilic acid, indacrinone or furosemide. Tienilic acid decreased cell viability and glutathione content in hepatocytes and increased lipid peroxidation in the cells. Indacrinone also decreased cell viability, but neither cell viability nor glutathione content was affected by furosemide or DR-3438.

Decrease in neutrophil migration induced by endotoxin and suppression of interleukin-1 production by macrophages in lactic dehydrogenase virus-infected mice

Neutrophil (PMN) migration into the peritoneal cavity after intraperitoneal injection of lipopolysaccharide (LPS), chemotactic activity of PMN, interleukin-1 (IL-1) production by macrophages (M phi) and its ability to attract PMN in mice chronically infected with lactic dehydrogenase virus (LDV) were compared with those in uninfected control mice. PMN migration into the peritoneal cavity decreased in infected mice when LPS was injected intraperitoneally. PMN chemotactic activity did not show any difference following infection. To assess the mechanism of this decreased PMN migration, IL-1 production, which is responsible for PMN attraction, was studied in LDV-infected mice. IL-1 production by M phi derived from infected mice decreased and its ability to attract PMN was weak. IL-1 production by M phi from control and infected mice increased after treatment by indomethacin and LPS. PMN migration into the peritoneal cavity increased after treatment with indomethacin and LPS in both control and infected mice. However, the rate of increase of IL-1 production and PMN migration was greater in infected mice. These results suggest that the excess activation of cyclo-oxygenase-derived products (prostaglandins) in infected mice might be responsible for the suppression of IL-1 production by M phi, resulting in decreased PMN migration induced by endotoxin.

Development of single-mode four-fiber ribbon splicer with accurate splice loss estimation

A mass-fusion splicer for single-mode four-fiber ribbon has been developed with an accurate splice loss estimation function capability. Measurements in two orthogonal directions are used to obtain a high axis offset resolution of 0.3 microm. An average splice loss of 0.05 dB and an average splice loss estimation error of -0.002 dB are achieved.

Anti-thyroglobulin antibodies induced with recombinant reovirus infection in BALB/c mice

BALB/c mice that are infected with reovirus Type 1 develop thyroiditis. Viral antigens were seen in the cytoplasm of epithelial cells but not in the surrounding colloidal space of the thyroid. Examination of sera from the infected mice revealed autoantibodies that, by immunofluorescence, reacted with second antigens in the colloid (ground-glass staining pattern) and thyroglobulin (puffy staining pattern). An enzyme-linked immunosorbent assay designed to identify the reactive antigens showed the autoantibodies to direct against thyroglobulin. Synthetic serum thymic factor (FTS) suppressed autoantibody production to the thyroid after reovirus Type 1 infection. Reovirus Type 3, in contrast to reovirus Type 1, did not induce autoantibodies to react against thyroglobulin. By the use of recombinants between reovirus Type 1 and Type 3, the segment of the reovirus genome responsible for the induction of autoantibodies to thyroglobulin was identified. Virus containing the S1 genome segment from reovirus Type 1, which codes the sigma 1 polypeptide (i.e. haemagglutinin), infected epithelial cells in the thyroid and induced autoantibodies against the thyroglobulin. However, virus containing the S1 gene segment from reovirus Type 3 failed to infect cells in the thyroid and did not induce autoantibodies against thyroglobulin. In this study, reovirus Type 1 induces thyroiditis and autoimmunity, and the S1 gene segment is required for the induction of autoantibodies against thyroglobulin.

A single gene controls resistance to Japanese encephalitis virus in mice

The inheritance of resistance to Japanese encephalitis virus (JEV) was investigated using inbred strains of mice to study genetic resistance against JEV infection. C57BL/6 mice immunized intraperitoneally (i.p.) with an infective dose of JEV were resistant to intracerebral (i.c.) challenge with JEV, whereas most C3H/He mice treated in the same manner died. C57BL/6 mice developed this resistance 2 weeks earlier than C3H/He after intraperitoneal (i.p.) immunization. Passive transfer of spleen cells from immunized C57BL/6 protected the recipient mice from i.c. challenge, while transfer from immunized C3H/He was less effective. Since immunized athymic nude mice were not resistant to i.c. challenge with JEV, T lymphocytes were considered to be necessary for protection. When F1, F2 and backcross mice derived from C57BL/6 and C3H/He were challenged i.c. with JEV after i.p. immunizations, the number of resistant and susceptible mice were consistent with Mendelian ratios. Thus it can be concluded that resistance to JEV in mice was controlled by a single, dominant autosomal gene which was not linked to a (non agouti)-locus (chromosome 2).

Characterization of lymphocyte subpopulations in the blood of the cynomolgus monkey using flow cytometry

This study was performed to assess the usefulness of flow cytometry in comparison with acid alpha-naphthyl acetate esterase (ANAE) staining for the enumeration of lymphocyte subpopulations in cynomolgus monkeys. For flow cytometry, use was made of mouse antihuman leukocyte monoclonal antibody (T11), recognized to undergo cross-reaction with monkey T lymphocytes or antimonkey IgG serum labelled with fluoroscein isothiocyanate. The percentages of lymphocyte subpopulations in mononuclear cells of thirty healthy female cynomolgus monkeys were 72.1 +/- 2.4% for T cells and 24.6 +/- 2.4% for B cells as assayed by flow cytometry evaluation, and 63.8 +/- 2.5% for T cells and 15.8 +/- 2.2% for B cells as determined by ANAE staining. Although the percentage of T cells shown by ANAE staining was significantly lower than that seen with flow cytometry, the coefficient of correlation indicated a close correlation in both T and B cell subsets between these two methods. In monkeys receiving 20 mg kg-1 cyclophosphamide daily for 14 days, counts of all leukocytes and T and B cells were decreased, whereas animals treated with 1.0 mg kg-1 muroctasin daily for 14 days showed higher monocyte and neutrophil counts without changes in T or B cells. These results suggest that flow cytometry evaluation has several advantages over ANAE staining with respect to rapidity and precision in toxicological studies using large numbers of monkeys.

Reovirus type 2-induced diabetes in mice prevented by immunosuppression and thymic hormone

Reovirus type 2 that had been isolated from a cow with diarrhoea and passaged in bovine kidney cell culture produced a Type 1 (insulin-dependent) diabetes-like syndrome when inoculated into NC mice. The infection resulted in insulitis and destruction of islet cells. Viral antigens were found in islet cells by staining with fluorescein-labelled antibody to reovirus type 2. The destruction of islet cells resulted in abnormalities shown on glucose tolerance testing. Studies on the susceptibility of the host showed that only certain strains of mice had overtly abnormal glucose tolerance tests when infected with reovirus type 2. To assess the immunological role in the pathogenesis of reovirus type 2-induced diabetes, infected mice were subjected to immunosuppressive or thymic hormone treatment. The administration of either anti-thymocyte serum or serum thymic factor reduced or prevented the development of the diabetes-like syndrome, while Arg-Lys-Asp-Val-Try did not show any therapeutic effects.

Influences of cephem antibiotics on the immune response in mice

The effects of six cephem antibiotics, including ceftezole, cefmetazole, cefoxitin, cefotiam, cefoperazone, and cefotaxime, on murine humoral immunity were examined. In female BDF1 mice each cephem antibiotic was administered at a dose of 800 mg/kg/day i.v. for 7 consecutive days. Among the antibiotics tested, only ceftezole and cefoperazone induced a significant increase in serum total IgM, but not in serum total IgG. Especially in case of ceftezole, the mice developed splenomegaly due to the proliferation of IgM-producing cells in the germinal centers. The proliferation of splenic IgM-producing cells was also observed in female thymus-deficient Balb/c-nu/nu mice receiving intravenous ceftezole. Thus, the drug was indicated to enhance the polyclonal IgM production in mice by acting as a B cell mitogen. This is consistent with the in vitro finding that ceftezole exhibited a mitogenic effect on whole spleen cells from BDF1 mice, but not on B cell depleted spleen cells.

Response of large and small coronary arteries of pigs to intracoronary injection of acetylcholine: angiographic and histologic analysis

With coronary arteriography we examined the effect of acetylcholine (ACh) on large and small coronary arteries. ACh (12.5 to 200 micrograms) was injected into the right coronary arteries of 10 pigs during left ventricular pacing. The percentage of narrowing of the epicardial major coronary artery was used as an indicator of the constriction of the large coronary arteries, and the time required for the contrast medium to reach the posterior descending coronary artery from the ostium of the right coronary artery (blood-flow delay) was used as an indicator of the constriction of the same coronary arteries. A small dose of ACh (12.5 to 100 micrograms) induced mild narrowing (14 to 41%) of the epicardial major coronary artery and a marked blood-flow delay of over 7.0 sec (control: less than or equal to 1.8 sec) in all 10 pigs. A large dose of ACh (100 to 200 micrograms) caused over 75% narrowing of the epicardial major coronary artery and a marked blood-flow delay in 4 of the 10 pigs. When the marked blood-flow delay appeared, the perfused right ventricular myocardium became macroscopically anemic (ischemic). The constriction of large and small coronary arteries was not prevented by diphenhydramine (H1 blocker: 100 mg i.v.), but was prevented by pretreatment with atropine (1.0 mg i.v.). The intracoronary injection of histamine (1.5 mg) in 5 pigs constricted the epicardial major coronary artery over 75% in 2 pigs, 50 to 75% in 1 pig, and 25 to 50% in 2 pigs, but there was no evidence of blood-flow delay. Neither methoxamine nor norepinephrine caused any significant coronary artery narrowing. The histology of the large and small coronary arteries was examined quantitatively with an image analyzer. The coronary artery showed no intimal thickening, and the endothelium was intact on light microscopic examination. The % area of the smooth muscle layer (media) to the calculated total vascular area, and the ratio of the calculated medial thickness to the calculated inner radius (h/Ri) were 64 +/- 7% (mean +/- SD) and 0.69 +/- 0.16, respectively, in the small coronary arteries less than 100 microns in external diameter, 47 +/- 9% and 0.39 +/- 0.12 in the small coronary arteries 100 to 2000 microns in external diameter, and 34 +/- 4% and 0.24 +/- 0.03 in the large right coronary arteries over 2000 microns in external diameter; the % area of the media and the h/Ri showed a negative correlation with the size of the coronary arteries.(ABSTRACT TRUNCATED AT 400 WORDS)

Susceptibility of four species of small rodents to encephalomyocarditis (EMC) virus infection

The D variant of encephalomyocarditis virus (10(1)-10(5) PFU/head) was intraperitoneally inoculated into 4 species of small rodents, rats, mice, Syrian hamsters, and Mongolian gerbils, and the susceptibility of these animals to EMC virus was examined virologically and histopathologically 3 days after infection. Viral replication was detected in the brain (mice), in the heart (mice and gerbils), and in the pancreas (mice, hamsters, and gerbils). No viral replication was detected in rats. Histopathological changes were seen in the brain (mice and hamsters), in the heart (mice and gerbils), and in the pancreas (mice, hamsters, and gerbils). No histopathological changes were seen in rats. The present results suggest that it may be quite possible to produce EMC virus-induced diabetes mellitus not only in mice but also in hamsters and gerbils.

[Studies related to the discoloration in the surrounding gingiva of fixed prosthesis. 2. Detection period of silver-sulfate and the effects of metal alloys]

The purpose of this study is to investigate the relationship between gingival discoloration and Ag2S. Minute granules of dental alloys were embedded in the gingiva during a 5-11 months span, and their histological and colorimetric analyses were undertaken. Results showed the following; 1. Cases of low melting silver alloy, 12% Au-Ag-Pd alloy, and Ni-Cr alloy all resulted in gingival discoloration, but it did not occur during the specified experimental period. 2. Regardless of the size of the granules or time, the electron microanalyser showed no signs of sulfer detection in cases of low melting silver alloy. However, in the case of 12% Au-Ag-Pd alloy, sulfer was detected 5 months later for only those granules having the size of 0.2-0.3 microns. No sulfer was detected in cases of Ni-Cr alloy. 3. Although no proliferation of inflammatory cells were observed around those areas surrounding the 12% Au-Ag-Pd alloy granules, they appeared in cases of the low melting silver alloy and Ni-Cr alloy.

Endotoxic properties of chemically synthesized lipid A analogs. Studies on six inflammatory reactions in vivo, and one reaction in vitro

Biological activities of two groups of synthesized lipid A analogs, the counterpart of biosynthetic precursor, Lehmann's Ia type, 406, and E. coli lipid A type, 506, as well as their non-phosphorylated, and mono-phosphorylated analogs were investigated. The activities employed included four bone marrow cell reactions in mice, mice skin reaction, leukocytes migration in rabbits' cornea, and hemagglutination. Compound 406 and 506 elicited bone marrow reactions in mice and hemagglutination of mouse RBC, although 406 failed to elicit hemorrhage and necrosis also in mice skin. Compound 406 did not elicit corneal reaction in rabbits. The results suggest that for elicitation of this reaction and mice skin reaction, acyloxyacyl structure is required. Cytotoxicity and thromboplastin production of four bone marrow reactions had been reported by us to be endotoxic reactions, since these had not been elicited by peptidoglycan of Lactobacillus and Staphylococcus (1981) and 300 series synthesized analogs (1984) which did not have endotoxic structures. From these results, it seems that these two marrow reactions and hemagglutination require, as does the limulus test, the lipid A part structure as is present in 406.

Studies on experimental conditions for detecting phototoxic potentials of drugs in Balb/c mice

This study was designed to establish a procedure for detecting the phototoxicity of drugs in an animal model. Experimental conditions in relation to intensity distribution of ultraviolet-A (UVA), duration of irradiation, and suitable region for irradiation were investigated. One black light gave a wide constant-energy region when the distance from the light source to the irradiation area was 15 cm. The intensity distribution of a bank of 10 black lights formed a pattern like the contour map of a truncated cone in the irradiation area. In phototoxic studies, Balb/c strain mice were orally administered chlorpromazine and nalidixic acid, clinically known as photosensitizers, and were immediately exposed to UVA irradiation. The optimal irradiation time was 4 hours at an energy of 20 Joules/cm2, which with a high frequency caused erythema on the surface of the ears in the central area, which received about 1.5 mW/sec.cm2, but no reaction occurred in the surrounding area (0.5-0.8 mW/sec.cm2). These results indicate that it is important to select a suitable irradiation area and sufficient intensity of irradiation in order to determine whether a drug has phototoxic potential.

Influence of propranolol on high energy phosphate and tissue acidosis in regional ischemic myocardium of pigs: assessment with arterial pressure and respiration gated in vivo 31-phosphorus magnetic resonance spectroscopy

In an attempt to define the metabolic abnormalities of the ischemic myocardium, the changes in high energy phosphates, inorganic phosphate and intracellular pH were serially and quantitatively evaluated in ischemic porcine hearts having no collateral circulation, using arterial pressure and respiration gated in vivo 31P magnetic resonance spectroscopy. The protocol was also modified for propranolol pretreatment (0.6 mg/kg intravenously) to define its effect on the metabolism of ischemic myocardium. In the non-treated group, creatine phosphate was rapidly depleted by 10 minutes after ischemia; by 40 minutes, ATP and intracellular pH gradually decreased to 10 +/- 11% of control and to 5.90 +/- 0.26, respectively, and inorganic phosphate rose to 303 +/- 43% of control. In the propranolol treated group, the concentrations of creatine phosphate and ATP were higher, and those of inorganic phosphate and tissue pH were similar compared with controls during 40 minutes of ischemia. This suggests that the beneficial effect of propranolol on the ischemic myocardium is due to the preservation of ATP, an essential energy resource for numerous enzymatic reactions in viable myocardium.

[Correlations between results of selective intracoronary thrombolysis and histologic findings of the infarct-related coronary arteries]

To define the histopathogenesis of successful and unsuccessful recanalization following selective intracoronary thrombolysis, coronary angiography (CAG) in thrombolysis and histologic findings were compared in 13 patients who died within four days (mean 1.5 days) after the procedure. Thirteen infarct-related arteries were evaluated in respect to recanalization; presence of an intraluminal thrombus, and rupture and hemorrhage of atheromatous plaques were histologically evaluated in serial sections. Intraluminal thrombi of the infarct-related coronary artery were found in all of the five cases with unsuccessful recanalization and in none of the eight cases with successful recanalization. Rupture and hemorrhage of atheromatous plaques in infarct-related arteries were observed in all of the five cases with unsuccessful recanalization and in seven of the eight cases with successful recanalization. It was concluded that 1) in recanalized cases, thrombi are considered to be lysed; 2) unsuccessful recanalization does not necessarily indicate the absence of thrombi; and 3) rupture and hemorrhage of atheromatous plaques do not affect recanalization.

Rapid development of renal lesions in diabetic DBA mice infected with the D-variant of encephalomyocarditis virus (EMC-D)

Marked hyperglycaemia and renal lesions developed rapidly in DBA mice infected with 10 plaque-forming units of the D-variant of encephalomyocarditis virus (EMC-D). Renal alterations were demonstrated in the glomeruli, tubular epithelium and small vessels 2 months after infection. Glomerular changes were characterized by mesangial thickening due to an increase of basement membrane-like material in the mesangial matrix. Nodular glomerular lesions were commonly observed 3 months after infection, whereas distinct thickening of the glomerular basement membrane was rarely seen. Besides these glomerular changes, glycogen inclusions in the distal tubular epithelium and medial degeneration in the arterioles were also noticed. The EMC-D-infected DBA mouse appears to be a useful experimental model for the study of human diabetic nephropathy.

Cineangiographic and pathological features of the infarct related vessel in successful and unsuccessful thrombolysis

The postmortem histology and the results of cineangiography after selective intracoronary thrombolysis in vessels that were recanalized and in those that were not were compared in 21 patients who died within seven days (mean 2 days) of selective intracoronary thrombolysis. There was a persistent intraluminal thrombus in the infarct related coronary artery in five of six segments in which recanalisation was unsuccessful and in one of 15 segments in which recanalisation was successful. Rupture and haemorrhage of the atheromatous plaque were seen in most of the infarct related segments, both in those in which recanalisation was achieved and in those in which it was not. Irregular narrowing and filling defects on the coronary cineangiograms were associated with rupture and haemorrhage of the atheromatous plaque. These results suggest that failure of coronary thrombolysis to recanalize the infarct related artery does not indicate that the occlusion was not caused by thrombus.

Acceleration of cell necrosis following reperfusion after ischemia in the pig heart without collateral circulation

A study of whether reperfusion accelerates cell death was performed in 35 pig hearts without collateral circulation. In 15 animals, the distal one-third of the left anterior descending coronary artery was occluded for 1 hour followed by 1-, 3-, or 7-hour reperfusion in 5 animals each. As controls, 5 hearts each were examined after 1, 2, 4 and 8 hours of occlusion of the artery without reperfusion. Heart rate and aortic pressure before and during occlusion and reperfusion did not change in any group. The subepicardial and subendocardial regional blood flow decreased to almost zero in all hearts after occlusion (85 +/- 1 to 2 +/- 2) but recovered during reperfusion (65 +/- 15 ml/100 g/min). Specimens were histologically examined by an enzyme method using nitrotetrazolium blue, an immunohistochemical method using myoglobin antibody, by staining with hematoxylin-eosin and Masson's trichrome. In the control hearts, clear demarcation of the infarct area was observed 4 hours after occlusion. However, in the reperfusion group, clear demarcation of the infarct was seen after 1-hour reperfusion, namely, 2 hours after the onset of infarct. Demarcation was seen not only in the tissue with contraction band necrosis, but also in the tissue with coagulation necrosis. Therefore, it is concluded that reperfusion accelerates cell death due to both contraction band necrosis and coagulation necrosis.

Influence of L-methionine-deprived total parenteral nutrition on the tumor tissue and plasma amino acids fraction and the host metabolism: experimental study with Sato lung carcinoma-bearing rats

Creation of an amino acid imbalance, particularly curtailment of L-methionine, at the tumor cell level is thought to have a favorable effect on the inhibition of tumor growth. In the present study, we examined the influence of a specially-formulated amino acid mixture, avoid of sulfur-containing amino acids (L-methionine and L-cysteine), on the growth and amino acid fraction of Sato lung carcinoma (SLC) and the host metabolism in SLC-bearing rats. The rats were treated by total parenteral nutrition containing the above amino acid mixture, plus other nutrients (methionine-deprived TPN) for 10 days. Tumor growth began to decrease 4 days after the start of this treatment and the size was significantly less at the end of the treatment than in rats receiving conventional TPN with general purpose Vuj-N type amino acid solution as a protein source. The tumor-to-carcass weight ratio also showed a similar trend. In biochemistry, the albumin level and albumin-to-globulin ratio were significantly lower than in the rats receiving conventional TPN but other parameters such as total protein, glucose, GOT and GPT were not affected by the treatment. In the amino acid fraction of the tumor tissue extraction, both L-methionine and L-tyrosine were decreased and L-serine was increased significantly compared with the control group.

Experimental encephalomyocarditis virus infection in Mongolian gerbils (Meriones unguiculatus)

Two strains of Mongolian gerbils (Meriones unguiculatus), Tumble Brook (TUM) and Japan Medical Science (JMS), were intraperitoneally inoculated with the D variant of encephalomyocarditis virus (EMC-D) and killed 3 days later. Mortality was significantly higher in females than in males. Evidence of viral replication was detected in the heart of both strains and in the pancreas of the TUM strain. Histopathological alterations were found in the heart and pancreas. Heart lesions involved foci of necrosis with inflammatory cell infiltration and calcification in both strains. Pancreatic lesions were restricted to the exocrine glands; islets of Langerhans were rarely and secondarily involved in the extensive destruction of exocrine glands. Severe acinar cell necrosis with marked inflammatory edema was conspicuous in TUM, whereas only slight acinar cell involvement was detected in JMS gerbils. Immunoperoxidase staining showed viral antigens in intracytoplasmic vacuoles in damaged acinar cells.

Effect of ofloxacin on the uptake of [3H]thymidine by articular cartilage cells in the rat

Ofloxacin (900 mg/kg) was orally administered to Sprague-Dawley rats aged 4 weeks. A single dosage induced chondrocyte degeneration in the middle zone of the articular cartilage 5 h later and cavity formation 12 and 24 h later. The number of cells labeled with [3H]thymidine was decreased in histologically normal and abnormal cartilage at 5 h. Incorporation rate of [3H]thymidine into the articular cartilage was gradually decreased until 12 h later, but increased above the control level at 24 h. Another experiment showed that labeled cells were retained for a longer period than in control rats in the middle zone at the predilection site of osteochondrosis.

Effect of intraoperative radiotherapy on pancreatic carcinoma: histopathological findings from autopsy cases

Histopathological examinations of 18 necropsy patients with pancreatic carcinoma who died after receiving intraoperative radiotherapy (IOR) revealed the following: 1) Cancer cells were suspected of remaining in the periphery of the irradiated areas. 2) Thickening of intima of small arteries, some of which were obstructed, was found in the tumor tissues. 3) Highly degenerated nerve fibers were observed within the necrotic or viable tumor tissues. These findings provide evidence of the effects of IOR, while they also demonstrate the problems encountered in improving this treatment and the necessity of a complementary therapy for complete local control of pancreatic cancer by IOR.

Morphological investigation of osteochondrosis induced by ofloxacin in rats

Oral doses of 300 or 900 mg/kg/day of ofloxacin, a quinolone antibacterial agent, for 8 weeks induced a high incidence osteochondrotic lesions in rats. The predilection site of the lesions was the caudal area of the medial femoral condyle. Early changes included thickening of the middle zone of the articular cartilage with a markedly thinned deep zone. As the course of administration progressed, the columns of chondrocytes in the thickened middle zone became more and more numerous, many degenerated cells were seen, and the staining intensity of the matrix of the cartilage with with safranin-O decreased slightly. After the completion of dosing, the articular cartilage was markedly thickened and was made up mainly of middle zone cartilage. In advanced cases, a cleft was formed along the tidemark which occasionally extended to the articular surface. This resulted in erosion of the articular cartilage. Beneath the cleft there were focal necrosis of the subchondral bone and fibrotic lesions in the marrow space. Nalidixic acid also produced similar lesions in rats. The two drugs induced osteochondrosis in rats when treatment began at 4 weeks of age, but not at 8 weeks of age. This lesion was different in developmental process from the spontaneous osteochondrosis of rats, which is characterized by retention of the inherently thick deep zone.

Subacute toxicity of muroctasin in mice and dogs

The subacute toxicity of N2-[(N-acetylmuramoyl)-L-alanyl-D-isoglutaminyl]-N6-stearoyl-L-lysine (MDP-Lys (L18), muroctasin), a synthetic muramyl dipeptide, was investigated in mice and dogs. Both species exhibited leukocytosis, immunologically activated appearances of the axillary lymphnode and splenic white pulp, and irritatic lesions at the injection site, when treated with MDP-Lys(L18) for 4 weeks. Anemia, and synovitis were also found in dogs. These findings reflected main pharmacological action of MDP-Lys(L18), though there was some species difference.

Acute toxicity of muroctasin in mice, rats and dogs

Acute toxicity of N2-[(N-acetylmuramoyl)-L-alanyl-D-isoglutaminyl]-N6-stearoyl-L-lysine (MDP-Lys(L18), muroctasin), a synthetic muramyl dipeptide derivative, was studied in Std-ddy mice, Std-Wistar rats and beagle dogs by subcutaneous and intravenous administration. Subcutaneous LD50 values were 436 mg/kg for male, 625 mg/kg for female in mice, 761 mg/kg for male, 801 mg/kg for female in rats and more than 200 mg/kg for dogs. Toxic signs included screaming, decrease of locomotor activity, weakness, emaciation and loss of hair, crust formation, necrosis and ulceration around the injection site in all species. Death occurred within 7 days after treatment. Pathological examination revealed inflammation around the injection site. In dogs a subcutaneous cavity with puruloid fluid and enlargement of the axillary lymphnodes were seen in addition. No marked toxic signs and pathological findings were observed in mice and rats after intravenous administration of 90 mg/kg, a critical dose of treatment.

Chronic toxicity of muroctasin in mice

The chronic toxicity of N2-[(N-acetylmuramoyl)-L-alanyl-D-isoglutaminyl]-N6-stearoyl-L-lysine (MDP-Lys(L-18), muroctasin), a synthetic muramyl dipeptide, was investigated in mice. Leukocytosis and immunologically activated appearances of splenic white pulp and lung were seen in mice, when treated with MDP-Lys(L18) for 26 weeks. Furthermore, inflammation around the injection site and synovial epithelium hyperplasia of the tarsal joint occurred in higher incidence in the high dose group. These changes were similar to those seen in the subacute toxicity study with mice.

Morphological investigation of cavity formation in articular cartilage induced by ofloxacin in rats

Ofloxacin, a quinolone antibacterial agent, induced blisters and/or erosions in the articular cartilage of the humeral trochlea, femoral condyle, and femoral head of immature rats. Histologically, cavity formation was seen in the middle zone of the articular cartilage. Changes were detected as early as 5 hr after a single oral administration of 1000 or 3000 mg/kg. These changes were characterized by condensation, atrophy, and deformation of the nuclei of chondrocytes distributed in the middle zone. In such nuclei, aggregation of heterochromatin was observed. Degenerated cells with vacuolated and partially disintegrated cytoplasms were also seen in this zone. These lesions were followed by edema of the matrix accompanied with markedly decreased stainability with safranin-O, and a cavity was formed later by liquefaction of the cartilage. The changes were reversible, with rebounding occurring even with continued treatment with ofloxacin. The proliferation of chondrocytes around the lesion chiefly contributed to the repair. Ofloxacin had no adverse effects on the articular cartilage in rats when treatment was initiated at 8 weeks of age or later.

Histopathology of BALB/c mice infected with the D variant of encephalomyocarditis virus

BALB/c mice infected with 10(5) pfu of the D variant of encephalomyocarditis virus were examined histopathologically during the subacute stage of infection. Main pathologic changes were observed in the brain, heart (massive myocardial necrosis with subsequent organization (i.e., replacement of necrotic myocardium by connective tissue) and congestion and dilatation of the right ventricle) and pancreas (moderate degranulation of beta-cells resulting in elevation of blood glucose level). The brain lesions were found most frequently in the pyramidal layer of the hippocampus and the granular layer of the cerebellum and were characterized by degeneration of neurons containing virus antigens. Perivascular mononuclear cell infiltration, spreading to the adjacent brain tissue, and thrombosis in small vessels were also frequently seen. Focal loss of neurons and gliosis developed later in these lesions.

Distribution and progression of coronary arterial and aortic lesions in the conventional Watanabe heritable hyperlipidemic rabbit--quantitative analysis

The distribution and progression of coronary arterial and aortic lesions were examined in 40 conventional Watanabe heritable hyperlipidemic (WHHL) rabbits. They were classified according to age into stage I (3-5 months old, 14 rabbits), stage II (6-12 months old; 12 rabbits) and stage III (14-28 months old; 14 rabbits). Fifteen normal Japanese rabbits served as controls. The findings obtained from serial and transverse sections of each of the extramural coronary arteries (ECA) and transverse sections of 4 to 5 equal pieces of whole ventricle for intramural coronary arteries (ICA) were quantified by an image analyzer. Atherosclerosis with positive Sudan III stain was seen in aorta, ECA and ICA over 200 mu in diameter. Atherosclerotic lesions were noted in the aortic arch in stage I rabbits and in the whole aorta in stages II and III rabbits. In ECA, stenosis due to atherosclerosis was noted in 14, 33 and 93% of stages I, II and III rabbits, respectively. Stenosis of over 75% in the orifices of the left and right coronary arteries was noted frequently (71%), while mural thrombi, hemorrhage, intimal rupture and recanalization were seen rarely. Striking features were non-atherosclerotic stenosis with negative Sudan III, seen in the ICA less than 200 mu in diameter of almost all the hearts of stages II and III rabbits. Acute and old myocardial infarction appeared in 5 of the 14 hearts of the stage III rabbits and the infarct-related ECA showed severe stenosis of over 90%. In conclusion, to detect coronary atherosclerosis, serial and transverse sections of ECA are needed. In conventional WHHL rabbits, the incidence of stenosis in ECA is very high, compared with that of the previous reports, and myocardial infarction is due to severe stenosis in ECA. Non-atherosclerotic lesions in ICA occur before the appearance of the atherosclerotic lesions in ECA.