Biomedical subjects

H Takada

Publications and source records attributed to H Takada.

At least 145 records · Page 8Linked to original sources

PubMed1998

Inflammatory cytokine production and specific antibody responses against possible causative bacteria in patients with multilesional periapical periodontitis.

We examined the induction of inflammatory cytokines (including interleukin-1, interleukin-6, interleukin-8, and tumor necrosis factor-alpha) by several species of possible causative bacteria in periapical periodontitis. Assays were done on human whole blood cultures from patients with differing numbers of periapical lesions; those having radiographically clear periapical lesions in 10 or more teeth (high lesion group), in one or two teeth (low lesion group), and healthy volunteers having no periapical lesions (no lesion group). Prevotella melaninogenica ATCC 25845 induced interleukin-6 more strongly in subjects from the high lesion group than in the other groups. To ascertain the degree of sensitization by test bacteria, we examined the reactivities of antibodies in serum and saliva from the six subjects to different bacterial species. Porphylomonas gingivalis cells reacted strongly with sera from the high lesion group. Thus, Prevotella melaninogenica and Porphylomonas gingivalis may be involved in multilesional periapical periodontitis by inducing specific cytokines and/or humoral immune responses.

Aggregatibacter actinomycetemcomitans↗

PubMed1998

Mycoplasma pneumoniae meningoencephalitis and cerebellitis with antiganglioside antibodies.

A male patient with acute meningoencephalitis and cerebellitis associated with Mycoplasma pneumoniae infection is described. T2-weighted MRI demonstrated a high-intensity lesion involving the deep white matter of the right cerebellar hemisphere, which was not enhanced on injection of gadolinium. Brain perfusion scintigraphy revealed hypoperfusion in the bilateral cerebellar hemisphere. Polymerase chain reaction analysis using M. pneumoniae-specific primers failed to reveal the existence of the M. pneumoniae genome in cerebrospinal fluid. Conversely, serum antibodies to gangliosides (GM1, GM2, and GT1b) were detected, suggesting a mycoplasma-related neurologic disorder mediated by an immunologic mechanism. These findings support the hypothesis that vasculopathy and demyelination caused by an immunologic mechanism play an important role in the pathogeneses of neurologic disorders associated with M. pneumoniae infection.

Autoantibodies↗

PubMed1998

Contrasting effects of an aminobisphosphonate, a potent inhibitor of bone resorption, on lipopolysaccharide-induced production of interleukin-1 and tumour necrosis factor alpha in mice.

1. Aminobisphosphonates (aminoBPs), potent inhibitors of bone resorption, have been reported to induce inflammatory reactions such as fever and an increase in acute phase proteins in human patients, and to induce the histamine-forming enzyme, histidine decarboxylase, in mice. In the present study, we examined the effect of aminoBP, 4-amino-1-hydroxybutylidene-1,1-bisphosphonic acid (AHBuBP), on the production of the pro-inflammatory cytokines, IL-1 and TNFalpha, in mice. 2. Intraperitoneal injection of AHBuBP did not itself produce detectable levels of IL-1 (alpha and beta) and TNFalpha in the serum. However, the elevation of serum IL-1 induced by lipopolysaccharide (LPS) was greatly augmented in mice injected with AHBuBP 3 days before the LPS injection, whereas the LPS-induced elevation of serum TNFalpha was almost completely abolished. 3. Spleen and bone marrow cells taken from mice injected with AHBuBP produced IL-1beta in vitro spontaneously, and the production was augmented following the addition of LPS. Cells that accumulated in the peritoneal cavity in response to AHBuBP produced a particularly large amount of IL-1beta. However, AHBuBP treatment of mice did not lead to an impairment of the in vitro production of TNFalpha by these three types of cells. 4. Liposomes encapsulating dichloromethylene bisphosphonate (a non-amino BP) selectively deplete phagocytic macrophages. When an intraperitoneal injection of these liposomes was given 2 days after an injection of AHBuBP, there was a marked decrease in the LPS-induced elevation of serum IL-1 (alpha and beta) (LPS being injected 3 days after the injection of AHBuBP). 5. These results indicate that AHBuBP has contrasting effects on the in vivo LPS-induced production of IL-1 and TNFalpha in mice, enhancing the production of IL-1 by phagocytic macrophages and suppressing the production of TNFalpha, although underling mechanisms remain to be clarified.

Alendronate↗

PubMed1998

Eating habits, activity, lipids and body mass index in Japanese children: the Shiratori Children Study.

OBJECTIVE: To describe the eating habits and physical activity of Japanese children aged 10 y, and to investigate their relationship to lipids and body mass index (BMI); also to study the relationship between BMI and lipids in these children. DESIGN: This was a cross-sectional study conducted at six schools in Shiratori, Japan during 1992-1994. Physical examinations and questionnaires were used to collect data from 457 fifth grade children, aged 10 y. RESULTS: The diet of these children was mixed, with Japanese and Western foods almost equally reported. Boys were more active than girls. More active children had higher high density lipoprotein cholesterol (HDL-C), and children who ate a more Japanese diet had slightly lower HDL-C. BMI was positively related to cholesterol, low density lipoprotein cholesterol (LDL-C), triglycerides and inversely related to HDL-C. The amount of rice intake was positively associated with the BMI of these children. CONCLUSION: In our study of Japanese children aged 10 y, their diets were fairly Westernized, and most children were fairly inactive based on our activity score. Although obesity is low in these young Japanese subjects (14.1%), children who were obese (BMI>20) had worse lipid profiles than those who were not obese. An exceptionally high rice intake was associated with obesity, and thus may be an early warning sign for future obesity.

Body Mass Index↗

PubMed1998

The role of gammadelta T cells in induction of bacterial antigen-specific protective CD8+ cytotoxic T cells in immune response against the intracellular bacteria Listeria monocytogenes.

The role of T-cell receptor (TCR) gammadelta T cells in the induction of protective TCR alphabeta T cells against infection by the intracellular bacteria Listeria monocytogenes was analysed. We found that depletion of gammadelta T cells by anti-TCR delta monoclonal antibody treatment before intravenous immunization of mice with a sublethal dose of viable L. monocytogenes resulted in reduction of protection against secondary challenge infection in the immunized mice. The gammadelta T-cell depletion also reduced induction of protective alphabeta T cells capable of transferring the protection against challenge infection of L. monocytogenes into naive mice. Furthermore, the protective T cells that were affected by the gammadelta T-cell depletion were suggested to be CD8+ cytotoxic T cells rather than CD4+ T cells by the following observations. First, induction of cytotoxic T lymphocytes specific to a L. monocytogenes-derived H-2Kd-restricted peptide (listeriolysin O 91-99) was significantly suppressed by gammadelta T-cell depletion before immunization. Second, gammadelta T-cell depletion did not affect cytokine production and proliferation of T cells from immunized mice in response to in vitro stimulation with heat-killed Listeria which preferentially stimulates CD4+ T cells. Third, CD8+ alphabeta T cells from control immunized mice transferred protection against infection of L. monocytogenes into naive mice but only a limited degree of protection was transferred by CD8+ T cells from the gammadelta T-cell-depleted immunized mice; and fourth, CD4+ alphabeta T cells from the gammadelta T-cell-depleted mice transferred a similar level of protection as those from the control immunized mice. All these results suggest that gammadelta T cells participate in establishment of protective immunity against intracellular bacteria by supporting priming of bacterial antigen-specific CD8+ cytotoxic T cells.

Adoptive Transfer↗

PubMed1998

Interstitial fibrin-fibronectin deposition with T cell infiltrates precedes fibrosis in murine viral myocarditis.

This study was carried out to investigate interstitial fibrin and fibronectin deposition and subsequent myocardial connective tissue abnormalities in BALB/c-nu/+ (euthymic and normal T cell function) and BALB/c-nu/nu (athymic and T cell-deficient) mice. Both types of mice were inoculated with encephalomyocarditis virus and sacrificed periodically. Sections of the hearts were stained with haematoxylin-eosin, trichrome, lymphocyte subsets, silver impregnation, and fibrin or fibronectin. In addition, myocardial collagen concentration was measured. Interstitial fibrin and fibronectin appeared in parallel with inflammatory T lymphocytes and myocardial necrosis in the BALB/c-nu/+ mice. The changes increased until 14 days, subsequently decreasing with time. Interstitial fibrosis and abnormal reticulin fibres were absent until 7 days postinfection, and then increased with time until 60 days. In BALB/c-nu/nu mice, in contrast, although myocardial necrosis and fibrin-fibronectin deposition associated with immature T lymphocytes were evident on days 7 and 14, subsequent myocardial fibrosis and reticulin fibre abnormalities were minimal on days 30 and 60. In BALB/c-nu/+ mice, myocardial collagen concentration increased on day 30, but it did not in BALB/c-nu/nu mice. Thus, interstitial fibrin-fibronectin deposition resulting from virus-induced and T lymphocyte-mediated myocyte necrosis precedes the subsequent development of interstitial fibrosis and abnormal reticulin architectures in this model of murine myocarditis.

Animals↗

PubMed1998

Benign myoclonic epilepsy in infants: video-EEG features and long-term follow-up.

We report video-EEG findings and a long-term follow-up study in 10 patients with benign myoclonic epilepsy in infants (BMEI). A high incidence of a past and family history of febrile convulsions was noted. Six of the 10 patients manifested characteristic vocalization associated with myoclonic seizures. It consisted of a sudden, brief expiratory noise and is considered to be characteristic of BMEI. Afebrile convulsions occurred before the onset of myoclonic seizures or during the clinical course in six patients, but the accurate type of these seizures remains to be clarified. Monotherapy with valproatic acid (VPA) was very effective, but plasma VPA levels over 100 micrograms/ml were initially necessary in most of the cases, although they did not need to be maintained for further seizure control. All patients showed a favorable long-term seizure outcome, although one showed moderate mental retardation.

Adolescent↗

PubMed1998

Effects of fatty acids on liver metastasis of ACL-15 rat colon cancer cells.

The effects of eicosapentaenoic acid [EPA; n-3 polyunsaturated fatty acid (PUFA)], linoleic acid (LA; n-6 PUFA), and palmitic acid (PA; saturated fatty acid) on 1,2-dimethylhydrazine-induced F344 rat colon carcinoma cells (ACL-15) were investigated in vivo and in vitro. The number and size of liver metastatic foci via a superior mesenteric vein injection of ACL-15 cells in F344 rats were significantly inhibited in the EPA-treated group compared with the LA-treated group (p < 0.01); the PA-treated animals and those fed commercial rodent chow (standard diet) demonstrated intermediate values. In a dot immunoblotting assay, vascular cell adhesion molecule 1 expression on ACL-15 cells was downregulated by EPA-ethyl ester treatment and upregulated by LA-ethyl ester treatment compared with the untreated control cells, whereas the expression of matrix metalloproteinase 1 and 2 was not influenced by the fatty acid ethyl esters. In a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay, EPA-ethyl ester suppressed ACL-15 cell growth in a schedule-dependent manner, and LA-ethyl ester showed schedule-dependent stimulation. In contrast, PA demonstrated no regulatory effect on cell growth at lower concentrations (< or = 5 mg/ml) but concentration-dependent inhibition at higher concentrations. According to our in vivo cell kinetic study, the difference in tumor growth at the metastatic site was due to different tumor cell proliferation rates; the cell loss rate was not altered. Therefore, the inhibitory effect of liver metastasis on ACL-15 cells by EPA can be explained by a decreased ability of tumor cell adhesion to the capillary bed (low expression of vascular cell adhesion molecule 1) and a lower potential of tumor cell proliferation (low mitotic rate) at the secondary site.

Animals↗

PubMed1998

Response of parathyroid hormone to anaerobic exercise in adolescent female athletes.

It has been shown that moderate exercise suppresses parathyroid hormone (PTH) secretion, while strenuous exercise is apt to induce continuous secretion, which has a negative effect on bone mineral densities (BMD). The present study investigated a typical response of PTH to brief exercise. The study group comprised six adolescent female basketball players whose BMD were within normal limits. Maximal anaerobic power by three-step cycling was loaded on each subject. The first blood sample was drawn 30 min prior to testing test, the second was immediately following, the third was 15 min after, and the fourth was 30 min after. The proportional change in plasma volume was -11.5% immediately following (P < 0.05), +2.1% 15 min after, and +5.5% at 30 min after exercise (P < 0.05). The expected value was calculated on the assumption of no effect, except changes in plasma volume, by exercise. The measured values of PTH and calcium (Ca) immediately after exercise were lower than each of the expected values (P < 0.05 for both). At 15 min after, there was no significant difference between expected and measured values of PTH, Ca and magnesium (Mg), respectively. At 30 min after, the measured value of Ca and Mg was higher than each expected value (P < 0.05 for both). It was concluded that PTH secretion is suppressed transiently immediately after maximal anaerobic exercise and is then stimulated during the recovery time in normal BMD subjects.

Adolescent↗

PubMed1998

A lipoteichoic acid fraction of Enterococcus hirae activates cultured human monocytic cells via a CD14-independent pathway to promote cytokine production, and the activity is inhibited by serum components.

To elucidate the cellular activation mechanisms of lipoteichoic acid (LTA) compared with those of lipopolysaccharide (LPS), a quantitatively major LTA fraction, QM-1M, was prepared from hot phenol-water extracts of Enterococcus hirae (ATCC 9790) by hydrophobic octyl-Sepharose chromatography and by ion-exchange membrane (QMA-Mem Sep 1010) chromatography as a 60% 1-propanol- and 1 M NaCl-eluted fraction. Unlike the reference Escherichia coli LPS, QM-1M did not demonstrate any ability to induce cytokines in a human whole blood culture system in this study, whereas QM-1M induced a few cytokines such as interleukin (IL)-8 and tumor necrosis factor-alpha in human monocytic THP-1 cell and human peripheral mononuclear cell (PBMC) cultures in the absence of serum. Fetal calf and human sera decreased the above cytokine induction by QM-1M in THP-1 and PBMC cultures, whereas sera increased activities of the reference LPS. IL-8 induction in the absence of serum in response to QM-1M was demonstrated to proceed through a CD14-independent pathway unlike the reference LPS.

Cell Line↗

PubMed1998

Wax D of Mycobacterium tuberculosis induced osteomyelitis accompanied by reactive bone formation in Buffalo rats.

A suspension of heat-killed Mycobacterium tuberculosis in liquid paraffin has been reported to induce foot swelling accompanied by new bone formation in Buffalo (BUF) rats, which are low responders to the induction of adjuvant arthritis. In the present study, we found that wax D, a mycobacterial cell wall peptidoglycan fragment-arabinogalactan-mycolic acid complex, was an effective component of this bacterium for the induction of osteomyelitis accompanied by reactive bone formation in BUF rats. Chronic inflammation was produced in BUF rats by a single subcutaneous injection of wax D suspended in liquid paraffin. Other Mycobacterium species and Gordona bronchialis were also capable of inducing this reaction. Other bacterial cells including the acid-fast bacteria Nocardia and Rhodococcus, purified cell walls and peptidoglycans from Lactobacillus plantarum, wax C, cord factor, arabinogalactan and mycolic acid prepared from M. tuberculosis were inactive in this respect. In addition, when wax D was administered as a water-in-oil emulsion (Freund's type adjuvant), bone formation scarcely occurred in BUF rats. In Fisher (F344) and Wistar rats, both of which are responder strains to adjuvant arthritis, wax D in liquid paraffin did not induce bone formation.

Animals↗

PubMed1998

Heterogeneous expression and release of CD14 by human gingival fibroblasts: characterization and CD14-mediated interleukin-8 secretion in response to lipopolysaccharide.

To identify the role in periodontal inflammatory diseases of human gingival fibroblasts (HGF), the major constituents of gingival tissue, the expression of CD14, a possible lipopolysaccharide (LPS) receptor, and the release of soluble CD14 (sCD14) by HGF were examined. Among the HGF samples from the nine donors tested, more than 50% of the HGF from five donors expressed CD14 but less than 20% of HGF from the other four donors did so, as determined by flow cytometric analysis. The CD14 expression on the cell surface was correlated with the expression of CD14 mRNA. The HGF and skin and lung fibroblasts tested expressed no CD18, which indicates that fibroblasts do not possess other LPS receptors, such as CD11b/CD18 and CD11c/CD18. The CD14 expression by the HGF was decreased after subculturing and was highest at the confluent stage of culture. The treatment of high-CD14-expressing (CD14(high)) HGF with phosphatidylinositol-phospholipase C reduced CD14 expression; this result and the increase in a 55-kDa CD14 indicate that the membrane CD14 (mCD14) on the HGF may be a 55-kDa glycosylphosphatidylinositol-anchored protein. CD14(high) HGF spontaneously released 48- and 57-kDa sCD14. The total release of sCD14 by the HGF was augmented by gamma interferon and Escherichia coli LPS in accordance with the increased expression of mCD14. The CD14(high) HGF secreted interleukin-8 in response to LPS, and the secretion was completely inhibited by anti-CD14 antibody. These results suggest that (i) HGF consist of populations that are heterogeneous on the basis of different levels of expression of CD14 and (ii) CD14(high) HGF secrete inflammatory cytokines in response to LPS via CD14.

Adolescent↗

PubMed1998

Dual regulatory effects of interferon-alpha, -beta, and -gamma on interleukin-8 gene expression by human gingival fibroblasts in culture upon stimulation with lipopolysaccharide from Prevotella intermedia, interleukin-1alpha, or tumor necrosis factor-alpha.

In a previous study, we demonstrated that the amount of interleukin (IL)-8 mRNA expressed by human gingival fibroblasts stimulated with lipopolysaccharide (LPS) from Prevotella intermedia ATCC 25611 is increased by pre-treatment with beta or gamma interferon (IFN-beta or -gamma). In the present study, we identified the regulatory effects of these IFNs on IL-8 mRNA expression and IL-8 production by human gingival fibroblasts. Priming with IFN-alpha (alpha), -beta, or -gamma upregulated the IL-8 mRNA expression in response to P. intermedia LPS, whereas co-stimulation with these IFNs reduced the amount of mRNA expressed by the cells. The regulation of IL-8 mRNA expression induced by recombinant human tumor necrosis factor-alpha (rHuTNF-alpha) or rHuIL-1alpha was similar to that induced by LPS. The IL-8 mRNA expression in response to P. intermedia LPS was enhanced by IFN-gamma independently of de novo protein synthesis, and was regulated, at least in part, at the transcriptional level. The IL-8 mRNA accumulation in response to P. intermedia LPS was inhibited by tosylphenyl-alanyl chloromethyl-ketone, an inhibitor of NF-kappaB activation, although the NF-kappaB activation itself was not altered by IFN-gamma. These findings suggest that IFNs might be capable of both enhancing and inhibiting inflammatory responses in periodontal tissues through the dual regulation of IL-8 production by gingival fibroblasts in response to bacterial components and cytokines.

Blotting, Northern↗

PubMed1998

The relationship between R amplitude in lead V5 (RV5) and left ventricular mass in the groups of adolescent subjects classified by body composition.

How the amplitude of the R wave in lead V5 (RV5) of the ECG represents the left ventricular (LV) mass was investigated in 894 students aged 15 (boys: 545, girls: 349). The influence of body composition [ie, percentage of body fat (%fat)] was taken into consideration. A significant correlation was found between RV5 amplitude and LV mass for both genders. However, the relationship was stronger for boys than for girls. The students were then divided into 3 groups; that is, those at either the top or bottom 10th percentile (low or high-fat range) and the rest of the students (middle-fat range), depending on the % fat calculated by the bioelectrical impedance method. The significant correlation between RV5 and LV mass was found only for the 2 groups of boys whose percentage fat was in the low or middle-fat range. The correlation coefficients were 0.40 and 0.34, respectively. Moreover, in the boys' low-fat range, the RV5 of students whose LV mass was large (> or =90th percentile), was significantly higher (p<0.01) than in the other ranges. Setting a particular cutoff point of RV5 in the low-fat range of boys improved sensitivity as well as specificity (20-30% better among all boys) for detecting large LV mass. These observations suggest that classification of subjects by body composition could be improve the reliability of ECG assessment for left ventricular hypertrophy, although the gender and number of subjects in whom improvement is expected are limited.

Adolescent↗

PubMed1998

[An evaluation of the biting force, the body composition and the amount of masticatory action in young females].

UNLABELLED: The purposes of this study were to investigate factors related to maximum biting force and to understand the characteristics of physical properties of daily ingested foods in young females. One hundred and forty subjects aged 18-23, with Angle 1 class occlusion, had not suffered from periodontitis, and had not been treated for preparation of tooth crown of first molars. Body height and weight were measured, and percentage of body fat, fat mass (FM) and lean body mass (LBM) were estimated, using the impedance analyzer. The maximum biting force was measured by the press sensation method. According to the formula on the basis of our new version of Yanagisawa's food classification, the mean value of the amount of masticatory action for one day was calculated. Subjects were divided into the normal biting force and the low biting force groups with -1SD of the maximum biting force, in order to compare body composition and backgrounds in sports activities between these two groups. Multiple linear regression analysis was carried out, employing maximum biting force (kg.f) as a dependent variable, and having a background in sports activities, FM, LBM, the number of missing teeth, the number of dental caries and the amount of masticatory action for one day as independent variables. Results were as in the following: 1) The proportion of subjects who had a background in sports activities in the low biting force group were less than that in the normal biting force group (p < 0.01). 2) Having a background in sports activities and LBM were positively correlated to maximum biting force (p < 0.01), while the amount of masticatory action for one day was not. 3) All subjects, especially those in the low biting force group seldom had food requiring the highest amount of masticatory action. CONCLUSION: Having a background in sports activities and LBM are positively correlated with the maximum biting force, while the amount of masticatory action for one day was not correlated positively nor negatively in young females.

Adolescent↗

PubMed1998

Finger skin temperature and laser-Doppler finger blood flow in subjects exposed to hand-arm vibration.

OBJECTIVES: This study was aimed to assess the peripheral circulatory functions of forestry workers exposed to hand-arm vibration, using simultaneous measurements of finger skin temperature (FST) and finger blood flow (FBF). METHODS: The subjects were five men with vibration-induced white finger (VWF), four subjects with numbness in their hands and five exposed controls without any signs or symptoms related to vibration syndrome. Simultaneous measurements of FST and laser-Doppler FBF were performed before, during and following a 10-min recovery period after the hand was immersed in cold water (10 degrees C, 10 min). Partitional measurements of finger blood flows could be made between the capillaries and deeply located vessels using two laser-Doppler flow probes having narrower and wider optic fiber separations. RESULTS: The FST as well as the FBF of the capillary and deeply located vessels during and following the cold immersion test in those with VWF and in the subjects with numbness had a slight increase immediately following the cold immersion and no tendency to be augmented as the time span increased. After the cold immersion test, the control group had significantly greater FST and FBF compared to other groups. Particularly, from the 5th to the 10th min after the cold provocation, the values of FBF of the deeply located vessels in those with VWF were significantly lower than the controls. During the course of observation, the FST had significantly linear relationship with the recorded capillary and deep FBF values, and that was much closely correlated with the deep FBF (i.e., P < 0.01 in each selected condition). The slope of the regression lines in the capillary were steeper and shallow in the deep FBF. CONCLUSIONS: In addition to the measurement of capillary FBF, more detailed and accurate information on the peripheral circulatory functions of vibration-exposed subjects can be obtained by including the assessment of the deep FBF.

Aged↗

PubMed1998

20beta-hydroxysteroid dehydrogenase catalyzes ketone-reduction of acetohexamide, an oral antidiabetic drug, in liver microsomes of adult male rats.

We examined the catalytic properties and physiological function of an enzyme responsible for the ketone-reduction of acetohexamide, an oral antidiabetic drug, in liver microsomes of adult male rats. Progesterone, 17alpha-hydroxyprogesterone, cortisone and cortisol, which have a ketone group at 20-position of C21-steroids, were potent inhibitors for ketone-reduction of acetohexamide in liver microsomes of adult male rats. Progesterone was also found to inhibit competitively the ketone-reduction of acetohexamide, suggesting that the ketone-reduction of acetohexamide and progesterone is catalyzed by the same enzyme. When progesterone was used as a substrate, 20beta-hydroxysteroid dehydrogenase present in liver microsomes of adult rats, such as acetohexamide reductase, exhibited a male-specific and androgen-dependent activity. Furthermore, a significant correlation was observed between the activities of 20beta-hydroxysteroid dehydrogenase and acetohexamide reductase in liver microsomes of individual male rats at various ages. Based on all results, we conclude that 20beta-hydroxysteroid dehydrogenase catalyzes the ketone-reduction of acetohexamide in liver microsomes of adult male rats.

Acetohexamide↗

PubMed1997

Extracellular matrix remodeling in coxsackievirus B3 myocarditis.

The connective tissue abnormality in relation to T lymphocytes was investigated in murine myocarditis. Inbred BALB/c-nu/+ (euthymic and normal T cell function) and BALB/c-nu/nu (athymic and T cell deficient) mice were inoculated with coxsackievirus B3 (CB3). Hearts were stained with hematoxylin-eosin, Malloryazan, and silver impregnation, for reticulin fiber abnormalities, and T lymphocyte subsets. In BALB/c-nu/+ mice, active myocardial necrosis appeared parallel with T lymphocyte infiltrates, that is, it was absent on day 0, increased until 14 days, and then decreased with time. In contrast, the abnormal reticulin fiber architecture and interstitial fibrosis increased with time until 60 days, when ventricular remodeling was noted. In the hearts of BALB/c-nu/nu mice, although minimal myocardial necrosis associated with infiltrating immature T lymphocytes was noted earlier, subsequent interstitial fibrosis and reticulin fiber abnormalities were not documented later. The abnormal reticulin fiber architecture seen in BALB/c-nu/+ mice may contribute to the extracellular matrix remodeling in murine CB3 myocarditis in which dilated cardiomyopathy develops later.

Animals↗