An improved computer-assisted diagnostic scheme using wavelet transform for detecting clustered microcalcifications in digital mammograms

RATIONALE AND OBJECTIVES

We evaluated the potential usefulness of a computer-assisted diagnostic (CAD) scheme incorporating the wavelet transform for detecting clustered microcalcifications in mammograms.

METHODS

A wavelet transform technique was applied to the detection of clustered microcalcifications. We examined several wavelets to study their effectiveness in detecting subtle microcalcifications. We used a database consisting of 39 mammograms containing 41 clusters of microcalcifications. The performance of the wavelet-based CAD scheme was evaluated using free-response receiver operating characteristic analysis.

RESULTS

The CAD scheme with the wavelet transform was useful in detecting some of the subtle microcalcifications that were not detected by our previous scheme, which was based on the difference-image technique. When the two schemes were combined, the overall performance was improved to a sensitivity of approximately 95%, with a false-positive rate of 1.5 clusters per image.

CONCLUSION

The wavelet transform approach can improve the detection of subtle clustered microcalcifications.

Insulin suppresses endothelial secretion of C-type natriuretic peptide, a novel endothelium-derived relaxing peptide

We have previously reported that C-type natriuretic peptide (CNP), the third member of the natriuretic peptide family, is produced in vascular endothelial cells (ECs) and acts as an endothelium-derived relaxing peptide. We further demonstrated the detection of the gene transcripts of CNP and atrial natriuretic peptide (ANP) B receptor, a specific receptor for CNP, in human blood vessels. We thus propose the existence of a vascular natriuretic peptide system (NPS). CNP secretion was also demonstrated to be stimulated by various growth factors and cytokines. To clarify the significance of vascular NPS in proliferative vascular complications associated with diabetes, hypertension, or atherosclerosis, in the present study we examined the effect of insulin on CNP secretion from cultured ECs. Insulin at a concentration in the physiological range (10(-10)-10(-7) mol/l) potently suppressed CNP secretion, whereas insulin at the same concentration did not suppress endothelin (ET) secretion from EC. IGF-I had no significant effect on CNP secretion. Insulin, therefore, can be a potent inhibitor of CNP secretion through the activation of insulin receptor. Since CNP has been shown to be a potent inhibitor of vascular smooth muscle cell proliferation, the present study suggests the possibility that attenuated activity of vascular NPS is associated with hyperinsulinemia, which might result in proliferative vascular lesions.

Reconstruction of irreparable brachial plexus injuries with reinnervated free-muscle transfer. Case report

The complete avulsion of the brachial plexus is a severe injury usually caused by high-energy trauma. Even with the advent of modern microsurgical techniques, many patients have been rendered severely handicapped following this injury. The authors present a new reconstructive procedure that uses a microsurgical reinnervated free-muscle transfer to return prehensile function to an upper limb that is completely paralyzed. Although the procedure is still preliminary, a successful case is briefly described.

Effect of a computer-aided diagnosis scheme on radiologists' performance in detection of lung nodules on radiographs

PURPOSE

To evaluate the effect of a computer-aided diagnosis (CAD) scheme on radiologists' performance in the detection of lung nodules, and to examine a new method of receiver operating characteristic (ROC) analysis.

MATERIALS AND METHODS

One hundred twenty radiographs (60 normal and 60 abnormal with lung nodules of varying subtlety) were used. Sixteen radiologists (two thoracic, six general, and eight residents) participated in an observer study in which they read both conventional radiographs and digitized radiographs. The radiologists' performance was evaluated with ROC analysis with two different methods (independent testing and sequential testing) and a continuous rating scale.

RESULTS

Az (area under the best fit binormal ROC curve when it is plotted in the unit square) values obtained from ROC analysis with and without CAD output were 0.940 and 0.894, respectively, in the independent test and 0.948 and 0.906, respectively, in the sequential test. Findings with both methods indicated that the CAD scheme statistically significantly improved diagnostic accuracy, particularly for radiologists with less experience (P < .001). Reading time was not increased when CAD was used.

CONCLUSION

The CAD scheme can assist radiologists in the detection of lung nodules on chest radiographs.

[Antiplatelet therapy after open heart surgery]

This study evaluated the effects of an antiplatelet drug for the patients after open heart surgery. Dipyridamole (D), aspirin (A), ticlopidine (T) and sarpogrelate hydrochloride (S) were chosen as an antiplatelet drug. The 6 groups were devided into as G 1 with warfarin (W) and D, as G 2 with W alone, as G 3 with A and D, as G 4 with A alone, as G 5 with A and T, and as G 6 with A and S. The indices of anticoagulation and antiplatelet were as follows: TT, APTT, PT, D. Dimer, fibrinogen, TXB2, 6 kPGF1 alpha, beta TG, vWF and platelet aggregation with Grading Curve methods. The results showed that D.Dimer was beyond the normal range in G 1 and G 2. Thromboxane B 2 was increased markedly in G 1 and G 2 and showed under the normal range in G 3 and G 6. In all groups, 6 kPGF1 alpha showed low levels than normal. Activation of platelet causes the increased beta TG which was not suppressed with the antiplatelet drugs administered. The platelet aggregation was not suppressed in G 1 and G 2. Mild to moderate suppression was seen in G 3 and G 4 with no difference between the two group. Moderate to marked suppression was demonstrated in G 5 and G 6. This study demonstrated that dipyridamole had no effects as antiplatelet function. Aspirin showed antiplatelet effects and the combination of aspirin with the another antiplatelet drugs demonstrated the additional effects.

[Quick radioimmunoassay for plasma immunoreactive gastrin--application for localizing occult gastrinoma(s) during operation]

A rapid method for determining gastrin, quick gastrin, has been developed. Separation/washing procedure has been improved and can be completed within three minutes. It required only 48 minutes for the assay of 22 blood samples. Quick gastrin is a RIA that uses magnetic particles. On magnetic particles, a goat anti-rabbit IgG antibody is bound covalently. An anti-human gastrin rabbit antibody is bound to an anti-rabbit IgG antibody. Assay is started by adding the magnetic particles to a mixture of sample and 125I-gastrin. Following 30 minute incubation at 37 degrees C, the particles are sedimented in a magnetic field and washed. The gastrin content of the sample is then quantitated by counting radioactivity of the particles. Incomplete equilibration of antigen-antibody reaction is corrected using standard solution prepared from charcoal treated plasma. The immunoreactive gastrin values by quick gastrin correlated well with those by a commercial assay kit (Gammadab RIA kit; y = 1.01 x +4.3, r = 0.99). When compared to a reported conventional rapid assay, quick gastrin is easier and more accurate. Quick gastrin is sensitive enough to use for intra-operative determination of gastrin. We applied quick gastrin to the samples obtained from intra-operative secretin test in a gastrinoma patient. Twofold increases in gastrin after injection of secretin clearly indicated the existence of occult gastrinomas in her pancreas. When gastrin was assayed with the conventional rapid method, the increase in gastrin was less and did not reach the criteria for existence of gastrinoma.

Restoration of sensibility in the hand after complete brachial plexus injury

Twenty-one patients with complete brachial plexus palsy due to the avulsion of multiple cervical nerve roots underwent motor and sensory reconstruction. Of these, 15 patients who had been followed for at least 2 years were included in the present study. Sensory reconstruction was performed by nerve graft or nerve crossing to the median nerve. The donor nerves included the supraclavicular nerve in 10 patients, the intercostal nerve in 3, and the C5 nerve root in the first 2 patients. Limited sensibility in the median nerve distribution of the hand was restored in 12 patients, and the results were classified as S2+ in 2, S2 in 4, S1 in 6, and S0 in 3, according to the S0 to S4 grading system. No moving two-point discrimination was restored in any case. While the best recovery obtained was only at the S2+ level, even this limited sensibility was useful for otherwise completely anesthetic patients.

Novel compliant and tissue-permeable microporous polyurethane vascular prosthesis fabricated using an excimer laser ablation technique

A small-diameter vascular prosthesis with a multiply pored structure could have great potential to elevate the patency rate, for the following two reasons: 1) increased flexibility of the graft may increase compliance matching, consequently minimizing intimal hyperplasia; and 2) enhanced transmural tissue ingrowth may accelerate endothelialization. In this study, we fabricated a polyurethane (PU)-based artificial graft with well-controlled micropores in terms of their diameter and distribution, which was achieved using a computer-aided excimer laser (KrF) ablation technique. Three types of microporous PU tubes (2 mm in internal diameter, 100 microns in wall thickness) were designed: pore size (100 microns) and longitudinal pore-to-pore distance (200 microns) were constant, and circumferential pore-to-pore intervals were 60 degrees (type 1), 30 degrees (type 2), and 15 degrees (type 3). The fabricated prostheses were coated with photoreactive gelatin, which was photogelled and chemically fixed on PU surfaces upon ultraviolet light irradiation. Scanning electron microscopy showed that pore size and arrangement were precisely controlled as designed, and that a gelatinous hydrogel layer was formed over the entire luminal surface. The stiffness parameter (beta), inversely related to compliance, was determined from the change in external diameter against intraluminal pressure. An increase in the number of pores around the circumference decreased the beta value. The type 3 graft, the stiffness parameter of which was very close to that of human coronary artery, was the most compliant among the three types. The combination of excimer laser-directed microporing and photochemical surface processing techniques enabled the development of a novel compliant small-caliber vascular prosthesis, which is expected to show enhanced transmural tissue in growth in vivo.

Detection of the single-stranded DNA of Streptomyces plasmid pSA1.1 and a binding histone-like protein

Streptomyces plasmid pSA1.1 accumulated single-stranded DNA as replication intermediates in S. lividans; therefore, this plasmid was considered to replicate by a rolling-circle mechanism. A DNA-binding protein (pI > 9.7 and about 10 kDa) was purified on a denatured DNA-Cellulose column, then on a native DNA-Cellulose column. The N-terminal amino acid sequence of this protein has a high homology with bacterial histone-like proteins. In the gel retardation assay, this protein bound with the single-stranded DNA of pSA1.1. We propose that this protein may participate in the replication of pSA1.1.

Excessive production of nitric oxide in rat solid tumor and its implication in rapid tumor growth

BACKGROUND

Rapid tumor growth is caused by angiogenesis factors, growth factors, etc. We previously reported a possible connection between nitric oxide (NO) and enhanced vascular permeability in solid tumor. In the present experiment, the role of NO in solid tumor pathology was further investigated in animal tumor.

METHODS

To identify NO formed in solid tumor (AH136B) implanted in the feet of rats, electron paramagnetic resonance (EPR) spectroscopy was performed directly on the frozen tumor tissue at 110K by measuring endogenous nitrosyl iron-sulfur complexes, and by using exogenously added NO capturing agents, i.e., diethyldithiocarbamate (DETC)-Fe2+ and N-(dithiocarboxy) sarcosine (DTCS)-Fe2+ complexes. Induction of inducible isoform of nosymthase iNOS mRNA was examined with reverse transcriptase-polymerase chain reaction (RT-PCR) combined with Southern blot analysis. In addition, vascular permeability was assessed by measuring extravasation of 51Cr-labeled bovine serum albumin in solid tumor.

RESULTS

Strong EPR signals from NO adducts of DETC-Fe2+ and DTCS-Fe2+ as well as strong signals from NO-hemoglobin and dinitrosyl iron sulfur complex were generated by tumor. The signal height of NO-(DTCS)2-Fe2+ observed in AH136B solid tumor was increased as the tumor gained up to 1.75 g. Induction of iNOS mRNA expression was confirmed by the above methods. Enhanced vascular permeability was suppressed by NOS inhibitors N omega- monomethyl-L-arginine or S-methylisothiourea sulfate and augmented with administration of L-arginine.

CONCLUSIONS

Excessive NO production by iNOS in solid tumor was identified unequivocally by EPR spectroscopy. NO formed in solid tumor can be involved in enhanced vascular permeability and increased blood flow, and hence sustain tumor growth.

The effect of magnetization transfer in meniscal fibrocartilage

Magnetic resonance imaging of the knee was performed in 28 patients (ages 15-72 years), using a 1.5-T unit. Volume gradient echo (3D GRASS) acquisition with and without presaturation off-resonance RF pulse was used to evaluate magnetization transfer (MT) effects, determined by placing regions of interest on muscle, fat, hyaline, and fibrocartilage; the percent change in signal intensity was calculated and compared using a paired two-sample t test. An in vitro study of the normal meniscus from a cadaver containing a scalpel cut extending to an articular surface was performed to observe the relative improvement in contrast in the presence of a small meniscal defect. MR imaging of the specimen was performed using an Omega CSI 2.0-T system (General Electric Medical Systems, Fremont, CA). Analysis of clinical images resulted in signal loss, compared to that of the identically timed and tuned non-MT images of 47 +/- 5, 8 +/- 5, 49 +/- 5, and 57 +/- 7% for muscle, fat, articular cartilage and fibrocartilage, respectively. Application of MT improved the depiction of the artificially introduced meniscal defect. Meniscal fibrocartilage demonstrates significant MT effect after application of off-resonance RF presaturation, which may improve visualization of meniscal defects.

Regulation of endothelial production of C-type natriuretic peptide in coculture with vascular smooth muscle cells. Role of the vascular natriuretic peptide system in vascular growth inhibition

Recently, we have demonstrated that C-type natriuretic peptide (CNP) is produced in vascular endothelial cells (ECs). In the present study, we investigated the interaction of ECs and vascular smooth muscle cells (SMCs) for endothelial production of CNP and its action on vascular growth, using the EC/SMC coculture system. The concentration of CNP-like immunoreactivity in the medium was increased 60-fold within 48 hours in the EC/SMC coculture with direct contact compared with that in EC alone. Northern blot analysis revealed the augmented expression of CNP mRNA in the EC/SMC coculture. The accumulation of intracellular cGMP in the coculture was concomitantly increased, and this response was blocked by anti-CNP monoclonal antibody and HS-142-1, a nonpeptide atrial natriuretic peptide receptor antagonist. The concentration of biologically active transforming growth factor-beta (TGF-beta) in the culture medium of the coculture with direct contact of ECs and SMCs was elevated to the level to stimulate endothelial production of CNP. Actually, the neutralizing antibody against TGF-beta abrogated the cGMP accumulation in the coculture. These results show that endothelial production of CNP in the EC/SMC coculture is at least in part regulated by TGF-beta. Furthermore, the conditioned medium from ECs stimulated by TGF-beta was demonstrated to have a growth-inhibitory effect on SMCs, which was abolished by anti-CNP monoclonal antibody and HS-142-1. The treatment with anti-CNP monoclonal antibody and HS-142-1 also significantly increased the cell number of the EC/SMC coculture. The present study reveals the pathophysiological significance of endothelial CNP as a paracrine/autocrine vascular regulator for vascular growth in the interaction of ECs and SMCs.

An improved shift-invariant artificial neural network for computerized detection of clustered microcalcifications in digital mammograms

A shift-invariant artificial neutral network (SIANN) has been applied to eliminate the false-positive detections reported by a rule-based computer aided-diagnosis (CAD) scheme developed in our laboratory. Regions of interest (ROIs) were selected around the centers of the rule-based CAD detections and analyzed by the SIANN. In our previous study, background-trend correction and pixel-value normalization were used as the preprocessing of the ROIs prior to the SIANN. A ROI is classified as a positive ROI, if the total number of microcalcifications detected in the ROI is greater than a certain number. In this study, modifications were made to improve the performance of the SIANN. First, the preprocessing is removed because the result of the background-trend correction is affected by the size of ROIs. Second, image-feature analysis is employed to the output of the SIANN in an effort to eliminate some of the false detections by the SIANN. In order to train the SIANN to detect microcalcifications and also to extract image features of microcalcifications, the zero-mean-weight constraint and training-free-zone techniques have been developed. A cross-validation training method was also applied to avoid the overtraining problem. The performance of the SIANN was evaluated by means of ROC analysis using a database of 39 mammograms for training and 50 different mammograms for testing. The analysis yielded an average area under the ROC curve (A(z)) of 0.90 for the testing set. Approximately 62% of false-positive clusters detected by the rule-based scheme were eliminated without any loss of the true-positive clusters by using the improved SIANN with image feature analysis techniques.

Histochemical, lectin-histochemical and morphometrical characteristics of intestinal goblet cells of germfree and conventional mice

Histochemical, lectin-histochemical and morphometrical studies were carried out on intestinal goblet cells of 8-week-old germfree (GF) and conventional (CV) mice of the BALB/c strain. Except for the reactivity of cecal goblet cells to Dolichos biflorus agglutinin (DBA) and Ulex europeus-I agglutinin (UEA-I), there was no difference between GF and CV mice in histochemical and lectin-histochemical properties. In the cecal mucosa, DBA stained the goblet cells strongly in CV mice but not in GF mice and UEA-I stained the goblet cells strongly in the lower part of crypts in CV mice but only faintly in GF mice. These findings suggest that terminal residues of cecal goblet cell mucin were different in GF and CV mice. Morphometrically, cecal goblet cells were fewer in number and smaller in size in GF mice than in CV mice. In addition, high iron diamine-alcian blue staining made a very clear border between the cecum and colon, because cecal goblet cells were exclusively positive for sulfomucin and colonic goblet cells were predominantly positive for sialomucin.

Depletion of Mac1-positive macrophages protects DBA/2 mice from encephalomyocarditis virus-induced myocarditis and diabetes

DBA/2 mice treated with anti-Mac1 monoclonal antibody (MAb) failed to develop encephalomyocarditis virus (EMCV)-induced diabetes and myocarditis. Virus concentrations and the number of viral RNA-positive cells in the pancreas and heart were significantly reduced in mice treated with anti-Mac1 MAb. Mac1-positive macrophages seem to be involved in EMCV-induced disease and to affect the replication of EMCV in target organs.

Immunohistochemical study on the deposition of apolipoprotein E in cerebral and islet amyloidoses in cynomolgus monkeys (Macaca fascicularis)

To investigate the role of apolipoprotein E (apo E) in amyloidoses of cynomolgus monkeys, the localization of apo E in cerebral amyloid, including senile plaques and cerebrovascular amyloid, and in islet amyloid was examined immunohistochemically. Mature types of senile plaques with amyloid deposits and cerebrovascular amyloid showed intense immunoreactivity to both antisera to apo E and amyloid beta protein (A beta). In contrast, diffuse plaques without obvious Congophilic amyloid showed weak immunoreactivity to antiserum to apo E, but intense reactivity to antiserum to A beta. In addition, the number of these apo E-positive diffuse plaques was small compared with that of A beta-positive plaques. On the other hand, diabetic islet amyloid that was negative with A beta, reacted intensely with antiserum to apo E. These findings suggest that apo E plays an important role in amyloid fibril formation in several types of amyloidoses.

Vascular endothelial growth factor suppresses C-type natriuretic peptide secretion

Angiogenesis plays a pivotal role not only in wound healing and tumor progression but also in diabetic angiopathy, arteriosclerosis, and collateral formation of obstructive vascular diseases. Vascular endothelial growth factor (VEGF) is now thought to be an endothelium-specific and potent angiogenic factor. We previously demonstrated that C-type natriuretic peptide (CNP), originally isolated from porcine brain, is produced by endothelial cells and proposed that CNP can exert control over vascular tone and growth as a local vascular regulator. In the present study, we examined the effect of VEGF on CNP secretion from endothelial cells using the specific radioimmunoassay for CNP we developed. VEGF (1 to 100 ng/mL) dose-dependently suppressed CNP secretion from cultured bovine endothelial cells, and 100 ng/mL VEGF suppressed endothelial CNP secretion to 28% of control levels (31.7 +/- 5.5 versus 8.9 +/- 0.8 fmol/mL, vehicle versus VEGF). VEGF also suppressed CNP mRNA expression in endothelial cells 9 hours after administration. In contrast, basic fibroblast growth factor (20 ng/mL), an endothelium-nonspecific angiogenic factor, significantly stimulated CNP secretion by 290%. These results indicate that VEGF can regulate vascular tone and growth in the process of angiogenesis through suppression of endothelial secretion of CNP, which is an endothelium-derived vasorelaxing and growth-inhibitory peptide.

Auditory plasticity in cochlear implant patients

Dynamic range (DR) of cochlear implant electrodes and speech recognition scores (SRS) were chronologically studied in 23 post-lingually deaf subjects over a period of one year. DR significantly increased over one year (ANOVA, p = 0.03). When DR was compared among three groups of electrodes which were located in the inferior, ascending and superior segments of the cochlear basal turn, that in the superior segment showed the largest increase (p = 0.001), followed by those in the ascending and inferior segments. Vowel and consonant recognition scores with auditory cue were best 6 months after operation and were maintained at the level for one year. Although the time course of improvement differed between DR and SRS, a significant positive correlation was observed at 12 months after operation. Improvement of SRS could be a result of a DR increase in the superior segment of the cochlea, which should convey pitch information over the mid-frequency region.

Malignant and benign clustered microcalcifications: automated feature analysis and classification

PURPOSE

To develop a method for differentiating malignant from benign clustered microcalcifications in which image features are both extracted and analyzed by a computer.

MATERIALS AND METHODS

One hundred mammograms from 53 patients who had undergone biopsy for suspicious clustered microcalcifications were analyzed by a computer. Eight computer-extracted features of clustered microcalcifications were merged by an artificial neural network. Human input was limited to initial identification of the microcalcifications.

RESULTS

Computer analysis allowed identification of 100% of the patients with breast cancer and 82% of the patients with benign conditions. The accuracy of computer analysis was statistically significantly better than that of five radiologists (P = .03).

CONCLUSION

Quantitative features can be extracted and analyzed by a computer to distinguish malignant from benign clustered microcalcifications. This technique may help radiologists reduce the number of false-positive biopsy findings.

[Experience with 2 cases of traumatic diaphragmatic hernia occurred at the same time]

Two cases of traumatic diaphragmatic hernia (TDH) which occurred at the same traffic accident, are reported. The first case, a plain chest X-P was diagnostic of TDH. With thoracotomy and additional laparotomy, lacerated diaphragm was repaired. The second case, continual observation on plain chest X-P was useful to suspect TDH, and thoracoscopy was diagnostic. With thoracotomy diaphragm was repaired. Two patients recovered well. It has not been reported that two cases of TDH occurred at same trauma. For diagnosis of TDH, chest X-P is useful for suspicion, and thoracoscopy is useful for correct diagnosis. Surgical approach should be decided in consideration of phase, location, and complicated injuries.

Antitumor activity of vincristine encapsulated in glucuronide-modified long-circulating liposomes in mice bearing Meth A sarcoma

Liposomes modified with the uronic acid derivative palmityl-D-glucuronide (PGlcUA) have a long circulation time and tend to accumulate in the tumors of tumor-bearing mice. Taking advantage of this character, we investigated the therapeutic effect of vincristine (VCR) encapsulated in liposomes containing PGlcUA (dipalmitoylphosphatidylcholine/cholesterol/PGlcUA = 4:4:1 as a molar ratio) on tumor-bearing mice. VCR was loaded into liposomes by a remote loading method, and then free or liposomal VCR was injected intravenously into BALB/c mice bearing Meth A sarcoma implanted subcutaneously 5 days before hand. Single-dose administration of VCR (3.0 mg/kg) in PGlcUA-liposomes significantly suppressed tumor growth, and prolonged the survival time (T/C = 1.37). Furthermore, two-dose administration of the liposomes cured one third of the animals. The therapeutic effect of PGlcUA-liposomes was greater than that of control liposomes containing dipalmitoylphosphatidylglycerol instead of PGlcUA. PGlcUA-liposomes might thus be a useful tool for delivering antitumor agents to tumor tissues.

[Three cases of Lermoyez's syndrome and its pathophysiology]

Two cases of bilateral Lermoyez's syndrome and one case of unilateral Lermoyez's syndrome are reported. The patients had recurrent episodes of vertigo with improvement of hearing or tinnitus, which is characteristic is Lermoyez's syndrome. In case 1, a 48-year-old female, dehydration with glycerol or furosemide induced nystagmus and improved bilateral hearing and the gain of the vestibulo-ocular reflex, while overhydration with drinking water impaired bilateral hearing with disappearance of nystagmus. These findings indicate that she had endolymphatic hydrops in both ears, suggesting that simultaneous changes in bilateral cochlear and vestibular function induce Lermoyez's syndrome. In case 3, a 52-year-old female, which we already reported, endolymphatic collapse in both ears may have changed bilateral inner ear function, resulting in Lermoyez's syndrome. On the other hand, patients 2, a 47-year-old male, experienced a vertigo attack with improvement of unilateral hearing after defibrinogenation therapy. In this case, slowly developing insufficiency of the inner ear blood supply may have caused the gradual hearing loss. It seemed that decreasing blood viscosity by defibrinogenation allowed blood to rush into the labyrinth, causing vertigo but at the same time improving hearing. We proposed that there are two types of Lermoyez's syndrome, bilateral (cases 1 and 3) and unilateral (case 2).

Relation between distribution of viral RNA and development of histopathological changes in encephalomyocarditis virus-induced orchitis in mice

The relation between the distribution of viral RNA and the development of histopathological changes was investigated in the early stage of encephalomyocarditis (EMC) virus-induced orchitis in mice. Signals of viral RNA were first detected by in situ hybridization in a few Sertoli cells in almost intact germinal epithelia at 2 days post-inoculation (d.p.i.). The number of Sertoli cells bearing signals of viral RNA increased at 3 d.p.i. when mild degenerative changes were exceptionally found in germinal epithelia. Signals of viral RNA came to be detected not only in Sertoli cells but also in a small number of germinal cells and spermatogonia at 4 d.p.i. when mild to moderate degenerative changes developed in germinal epithelia, resulting in desquamation of degenerated cells. At the same time, virus-like particles were observed by electron-microscopy in the degenerated and desquamated germinal cells. At and after 5 d.p.i., luminal obstruction with cellular debris and inflammatory cells was generally found. These results suggest that EMC virus carried to seminiferous tubules via the blood first attacks Sertoli cells and then damages germinal cells and spermatogonia.

In vivo administration of serum thymic factor (FTS) prevents EMC-D virus-induced diabetes and myocarditis in BALB/cAJcl mice

The effect of serum thymic factor (FTS) on the D-variant of encephalomyocarditis (EMC-D) virus-induced diabetes and myocarditis in BALB/cAJcl mice was investigated. Mice pretreated with 50 or 10 micrograms of FTS were infected with 10 or 10(3) PFU of EMC-D virus. In the mice inoculated with 10 PFU of virus, 40% developed diabetes on post-infection day (PID) 14, whereas those treated with FTS (50 micrograms/administration) on day 2 and 1 before infection did not develop diabetes. FTS (10 micrograms)-pretreated mice developed diabetes. In histological observation, FTS non-treated mice which developed diabetes showed severe necrosis and inflammation of mononuclear cells in the islets of Langerhans and myocardia on 19 PID. Mice pretreated with 50 micrograms of FTS, however, manifested mild islet degeneration without any myocardial inflammation. Furthermore, in FTS non-treated mice, immunohistological staining showed a loss of insulin granules. This loss was markedly reversed and insulin granules remained largely intact in FTS-pretreated mice. Viral titers in pancreas of FTS-pretreated mice approximated well to those of non-treated mice on PID 4, 7 and 19. In mice inoculated with higher titer of EMC-D virus (10(3) PFU), however, 50 micrograms of FTS pretreatment did not change the course of these acute pathological developments (diabetes and myocarditis observed from PID 4).