Combined hepatocellular and cholangiocellular carcinoma in a dog

A transitional type of combined hepatocellular and cholangiocellular carcinoma developed in a 12-year-old male Yorkshire terrier dog. The tumor was histologically composed of both hepatocellular carcinoma and cholangiocellular carcinoma components, and both elements were closely intermingled. Intraluminal mucin accumulation in cytokeratin-positive tubular/glandular structures was observed within the cholangiocellular carcinoma components and this feature was useful histological marker for a differential diagnosis between combined hepatocellular and cholangiocellular carcinoma and a pseudoglandular type of hepatocellular carcinoma. This primary hepatic tumor is extremely rare in dogs.

[Recurrence of bullous pemphigoid after surgery: report of a case]

We report a 38-year-old woman with myoma uteri and bullous pemphigoid controlled by oral prednisolone (7.5 mg.day-1). She underwent transabdominal hysterectomy under epidural anesthesia using mepivacaine supplemented with intravenous midazolam and butorphanol, without untoward event. On the postoperative day 2, recurrence of bullous pemphigoid was noted. The skin lesion of pemphigoid was improved after increasing the prednisolone dose up to 60 mg a day.

Anti-metastatic effect of the sialyl Lewis-X analog GSC-150 on the human colon carcinoma derived cell line KM12-HX in the mouse

We investigated the inhibitory effect of the sialyl Lewis-X (sLeX) analog, GSC-150, on hepatic metastasis of the human colon carcinoma derived cell line, KM12-HX, which highly expresses sLeX antigen on the cell surface. The number of cancer nodules found in BALB/c nude mouse liver 6 weeks after intrasplenic injection of KM12-HX cells was significantly reduced by co-administration of GSC-150. The amount of [3H]thymidine-labeled KM12-HX cells distributed in liver was also significantly reduced by GSC-150 co-administration in lipopolysaccharide (LPS)-treated mice at 48 h after administration of the tumor cells, while GSC-150 did not reduce the amount of HX cells distributed at 30 min. Considering our previous report that the initial phase of the distribution of KM12-HX cells in liver is governed by their being trapped in the hepatic microvessels because of their large size (Mizuno et al., J. Hepatol., 28, 865-877, 1998), these results suggest that GSC-150 does not inhibit this first-pass trapping by microvessels, but inhibits the subsequent process which is more directly related to final metastasis. GSC-150 inhibited the adhesion of KM12-HX cells to tumor necrosis factor-alpha (TNF-alpha)-activated human umbilical vein endothelial cells (HUVECs). These findings imply that the anti-metastatic effect of GSC-150 in vivo could be explained by its inhibition of cell-cell interactions between cancer and host cells.

[Efficacy of radiofrequency catheter ablation in a patient with sinus node reentrant tachycardia]

We performed electrophysiological study and catheter ablation on a 62-year-old patient with supraventricular tachycardia(SVT). This SVT was reproducibly initiated and terminated by atrial stimulation during the electrophysiological testing. The P-wave morphology and atrial activation sequence of intracardiac electrograms were identical to those in normal sinus rhythm. SVT was terminated with carotid sinus massage that increased vagal tone, and for this reason, the reentry circuit of SVT could be localized in sinus node. On the basis of these findings, the SVT was diagnosed as sinus node re-entrant tachycardia and was successfully eliminated by radiofrequency catheter ablation. Radiofrequency catheter ablation would be effective in patients with sinus node reentrant tachycardia refractory to anti-arrhythmic drugs. It should, however, be performed with careful consideration to the influence of the sinus node.

Ventricular remodeling after cardiomyoplasty in heart failure sheep: passive and dynamic effects

BACKGROUND

Recent reports claim that cardiomyoplasty (CMP) has a girdling effect on the left ventricle, to prevent dilatation and functional deterioration, but the mechanism of its long-term effects on the native heart is not known. We compared the relative role of CMP's active squeezing and passive girdling in chronically failing hearts.

METHODS

After induction of stable heart failure (left ventricular ejection fraction = 27% +/- 7%) by staged coronary microembolization, CMP was performed in 11 of 18 sheep. After 8 weeks pacing training of the latissimus dorsi muscle (LDM), cardiac assist was begun with 1:2 synchronous bursts in 6 sheep (d-CMP, n = 6), and the LDM in the passive group (p-CMP, n = 5) remained unstimulated. Four (base line) and 30 weeks after induction of heart failure, the pressure-volume relationship was derived.

RESULTS

After 30 weeks in d-CMP the slope (Emax) of the end-systolic pressure-volume relationship increased by 66% +/- 55% (p < 0.05) and external work efficiency by 48% +/- 41% (p < 0.01). In the passive CMP and control groups, slope and external work efficiency were unchanged. Conversely, left ventricular end-diastolic volume decreased (-14% +/- 12%, p < 0.05) in the dynamic CMP group compared with a static course in the passive CMP group (3% +/- 10%, p > 0.05) and an increase (18% +/- 15%, p < 0.05) in controls.

CONCLUSIONS

Dynamic CMP improved native heart's contractility and external work efficiency. In addition, whereas passive CMP has simply a girdling effect, dynamic CMP also induces reverse left ventricular chamber remodeling.

Abnormal distribution of anionic sites in the glomerular basement membrane in glomerulonephritis of dogs infected with Dirofilaria immitis

Ultrastructural alteration of anionic sites (ASs) in the glomerular basement membrane (GBM) was studied in glomerulonephritis characterized by linear capillary IgG deposition in four dogs infected with Dirofilaria immitis and two normal control dogs using polyethyleneimine. ASs were identified as small dense particles distributed regularly in the lamina rara externa (LRE), but there were no ASs in the lamina densa (LD) of the GBM of the control dogs. In the glomeruli of the infected dogs, ASs were distributed regularly or irregularly in the thickened LD. ASs were in addition localized over the characteristic continuous bands of subendothelial dense deposits. The number of ASs of the LRE increased in all four infected cases as compared to the controls (p<0.01).

Salmonella contamination in commercial layer feed in Japan

A total of 4,418 samples of commercial layer feeds obtained in 1998 were investigated for the presence of salmonellae. A total of 146 strains of salmonellae which consisted of 32 serovars, including 20 strains of Salmonella Enteritidis, were isolated from 143 feed samples.

Vimentin/cytokeratin coexpression foci in a well-differentiated canine hepatocellular carcinoma

A number of pale-stained cell foci were observed within a well-differentiated hepatocellular carcinoma which developed in a 10-year-old male mongrel dog. The foci were composed of hepatocyte-like cells, but did not contain glycogen granules in their cytoplasm. Immunohistochemically, the focus cells coexpressed both bile duct type cytokeratin and vimentin. Electronmicroscopically, they were abundant in cytoplasmic organelles and contained bile pigments. Bile canaliculi were noted between the focus cells. The focus cells in the present case were considered to be neoplastic hepatocytes expressed bipotential features of hepatic stem cells.

Maintenance of blood heparin concentration rather than activated clotting time better preserves the coagulation system in hypothermic cardiopulmonary bypass

In cardiopulmonary bypass (CPB), despite heparin regimens in which the activated clotting time (ACT) is kept at more than 400 s, there is biochemical evidence of thrombin generation indicating activation of the coagulation system and increased fibrinolytic activity. Therefore, to reduce the coagulant activation has been one of the main issues in the improvement of CPB. The purpose of this study was to compare the heparin concentration with the ACT and to evaluate the effect of keeping higher heparin concentration on the coagulation and fibrinolytic systems during hypothermic CPB, employing moderate hypothermia (MHT) or deep hypothermic circulatory arrest (DHT). Heparin was either administered to maintain an ACT >400 s (ACT group) or to maintain a whole blood heparin concentration of 3 mg/kg (heparin group). At the lowest core temperature during CPB, the ACT and the heparinase ACT (unrelated to heparin concentration) were increased the most whereas the whole blood heparin concentration was less than half the initial concentration in both ACT groups of MHT and DHT. The thrombin-antithrombin III (TAT) content just after CPB in both MHT and DHT was significantly lower in the heparin group than in the ACT group. In conclusion, ACT does not reflect the whole blood heparin concentration during hypothermic CPB. Furthermore, maintenance of the higher heparin concentration during hypothermic CPB may suppress the activation of the coagulation system via thrombin inhibition. That effect was more remarkable in deep hypothermic CPB. Therefore, we believe that anticoagulation management during hypothermic CPB should be based on the maintenance of the higher blood heparin concentration.

Enterocolitis associated with dual infection by Clostridium piliforme and feline panleukopenia virus in three kittens

Dual infection by Clostridium piliforme and feline panleukopenia virus (FPLV) was found in three kittens. In all cases, we found focal necrosis and desquamation of epithelial cells with occasional neutrophil infiltration in the large intestine. Large filamentous bacilli and spores were observed in the epithelium by using the Warthin-Starry method. Electron microscopy revealed the vegetative forms with characteristic peritrichous flagella and spore forms. Immunohistochemically, these bacilli showed a positive reaction with mouse antisera against the RT and MSK C. piliforme strains. Polymerase chain reaction (PCR) using cecum specimens demonstrated the 196-bp band specific to C. piliforme 16S rRNA. All three kittens were also diagnosed as FPLV-infected on the basis of the characteristic mucosal lesions, including intranuclear inclusions and PCR study for the FPLV genomic DNA. The PCR techniques are useful for confirming the C. piliforme and FPLV infection in spontaneous cases.

Naturally occurring Tyzzer's disease in a calf

Naturally occurring Clostridium piliforme infection (Tyzzer's disease) was found in a calf. Light microscopic examination revealed multifocal coagulative necrosis in the liver, catarrhal gastroenteritis, tracheitis and pneumonia, and thymic atrophy. Warthin-Starry staining clearly showed large filamentous bacilli in bundles or criss-cross patterns within the hepatocytes and epithelium and smooth muscle cells of the ileum and cecum. Immunohistochemistry using anti-C. piliforme RT and MSK strain antisera showed positive reaction against the bacilli. Electron microscopic examination revealed bacilli within the hepatocytes that demonstrated a characteristic vegetative form, with peritrichous flagella, and spores. The polymerase chain reaction (PCR) study using the paraffin-embedded liver sections, the 196-bp DNA fragment specific to 16S ribosomal RNA of C. piliforme was amplified. The characteristics of these bacilli are consistent with those of of C. piliforme. The PCR technique using paraffin-embedded sections should be useful for confirming C. piliforme infection in spontaneous cases.

Eosinophilic proliferative pylephlebitis in the liver of Japanese beef cattle with fascioliasis

Intrahepatic pylephlebitis was detected in 17 Japanese beef cattle. Grossly, the intrahepatic vessels in the caudate lobe and/or in the periphery of the other hepatic lobes were thickened and protruded above the lobar surface. The vessel lumina were packed with white to red, waste thread-like contents. A few immature flukes were found in the bile ducts in 3 of the 7 cases with biliary thickening. Foci of hepatic necrosis and hemorrhage were scattered around the thickened vessels in 8 cases. Histologically, the interlobular veins were thickened due to severe intimal hyperplasia with endothelial proliferation and eosinophilic accumulation and medial hypertrophy, accompanied by fibrosis and eosinophilic infiltration in the portal areas. Hepatic tissues with necrosis and hemorrhage were surrounded by eosinophils and histiocytes including a granulomatous reaction. One immature fluke was detected in one of these regions of necrosis. Immunoperoxidase staining revealed that the small fluke, Kupffer cells, and histiocytes in the liver of all cases were positively stained with anti-Japanese Fasciola sp. antiserum. Enzyme-linked immunosorbent assay of the sera of 15 cases revealed that all were positive for the anti-Fasciola antibody. On the basis of these findings, the present cases were regarded as an atypical form of fascioliasis, characterized by eosinophilic proliferative pylephlebitis of the liver.

A case of congenital familial short femur diagnosed prenatally

A fetus at 24 weeks of gestation had been suspected of congenital familial bilateral short femur. The Japanese mother, 41 years old and 139 cm in height presented with bilateral short femur herself. The mother had two affected aunts and one affected daughter in her family history. Ultrasound examination was given to the mother for the first time at 24 weeks of gestation and it revealed bilateral short femur of 30 mm in length on the right and 31 mm on the left femur of the fetus. Other examinations were entirely normal and the pregnancy resulted in a full-term spontaneous vaginal delivery to a male baby. Birth weight was 2,790 g and the 1 and 5 min Apgar scores were at 8 and 10. Diagnosis was confirmed by skeletal radiographs.

Mechanism of initial distribution of blood-borne colon carcinoma cells in the liver

BACKGROUND/AIMS/METHODS

The distribution characteristics of a human colon carcinoma cell line, KM12-HX cells, were examined. After intraportal vein (i.p.v.) or intravenous (i.v.) injection into rats, almost all the injected tumor cells are distributed to liver or lung, respectively, both after 30 s and 30 min. Our previous kinetic analysis of the fate of tumor cells revealed that the cumulative amount of tumor cells distributed in the liver is a factor determining the degree of metastasis. Thus, we examined the mechanism of initial efficient trapping of tumor cells by the liver in more detail.

RESULTS

Thirty minutes after tumor cells were injected into the left ventricle of the heart, the distribution of tumor cells was more restricted in several tissues (kidney, small intestine, large intestine and spleen), as compared with the distribution of microspheres undergoing 100% extraction, indicating that the first-pass extraction of KM12-HX cells is incomplete in these organs. The hepatic first-pass distribution of these tumor cells was unaffected by pretreatment of liposomes, such that the preinjected amount was sufficient to saturate the phagocytotic function of macrophages. Thus, the mechanism of initial distribution of the tumor cells to the liver is different from the mechanism of liposome uptake by macrophages. Considering that the diameter of microvessels in sinusoid and KM12-HX cells is approximately 7 and 12 microm, respectively, it is possible that these tumor cells are trapped physically in hepatic microvessels. In fact, after i.p.v. injection of microspheres 5 microm in diameter, only 20% of the dose was distributed to liver and the rest to other tissues. In contrast, almost 100% of microspheres 10 microm in diameter were distributed to the liver.

CONCLUSIONS

These results support the hypothesis that the initial organ distribution of blood-borne tumor cells is determined by mechanical and physical properties of the cells.

Coxiellosis in domestic and wild birds from Japan

Serological evidence of infection with Coxiella burnetii was found in 41 (2%) of 1,951 domestic birds and in 167 (19%) of 863 wild birds from 17 and 5 prefectures in Japan, respectively, by microagglutination (MA) test. The bacteriological evidence of the infection was found in 17 (41%) of 41 domestic birds and 37 (22%) of 167 wild birds by the nested polymerase chain reaction (PCR). In addition, C. burnetii was isolated from five each of serum, spleen and fecal specimens from five jungle crows (Corvus macrorhynchos) (whose sera were positive by both the MA test and PCR) by inoculating laboratory mice. Domestic quail (Coturnix coturnix japonica) (3%), domestic muscovy ducks (Cairina moschata) (3%), domestic chickens (2%), domestic mallards (Anas platyrhynchos domesticus) (2%), carrion crows (Corvus corone) (37%), jungle crows (35%), and wild rock doves (Columba livia) (6%) showed serologic evidence of experience with C. burnetii. There was a tendency for a high prevalence among birds living and/or feeding in close proximity to infected livestock. This suggests that these birds are one of the less important links in maintaining the whole cycle of C. burnetii infection.

[A case of submitral left ventricular pseudoaneurysm following mitral valve replacement for infective endocarditis]

A 25-year-old female presented with high fever and dyspnea. She was diagnosed as infective endocarditis, severe mitral regurgitation, grade II A-V block and acute left heart failure We performed emergency mitral valve replacement. At operation, mitral ring abscess was found which was extended to submitral left ventricular wall. The abscess was excised and the defect of mitral annulus was repaired with Xenomedica patch. Left ventriography at 30 days after the operation showed a submitral left ventricular pseudoaneurysm (size: 30 x 26 x 33 mm) without evidence of infection. Further examinations showed that the aneurysm extended to the annulus of tricuspid valve through interatrial septum. About 1 year after the operation, she had paroxysmal atrial fibrillation due to right atrial overloading. We decided to perform reoperation. At reoperation, the ostium of the aneurysm was closed with a Xenomedica patch after taking off the prosthetic valve. It was very difficult to close the ostium because we could not see the submitral ventricular wall directly. Although postoperative course was good, she had complete A-V block necessitating permanent pacemaker.

Study on the pathogenesis of porcine serum-induced liver fibrosis in rats with special reference to the effects of hypertension

To investigate the pathogenesis of porcine serum (PS)-induced liver fibrosis in rats, two experiments were carried out, taking into consideration of hypertension and vascular changes. In Experiment I, spontaneous hypertensive rats (SHRs), two-kidney, one clip hypertensive F344 rats (2K1C rats), and normotensive F344 rats were given an intraperitoneal injection of PS of 0.5 ml twice a week for 8 weeks. Histopathological, immunohistochemical, and electron microscopical examinations were performed on the liver from each rat. Histological features of liver fibrosis in hypertensive and normotensive rats were essentially identical. However, in the PS-treated SHRs, 2 of 5 animals showed the most severe fibrosis in all PS-treated groups. Electron microscopically, degranulated mast cells, eosinophils, and macrophages engulfing apoptotic cells were rarely observed in the late stage of fibrous septa (FS) in the PS-treated SHR liver. In Experiment II with normotensive F344 rats, histopathological features of early FS in the liver were compared with those of late FS observed in Experiment I using serial sections, and we found that FS developed along the wall of newly formed vessels to connect between neighboring central veins. However, the effect of hypertension on this fibrosis could not be clearly demonstrated in the present study using SHRs and 2K1C rats.

Hepatoblastoma in a dog

A hepatoblastoma was found in a 13-year-old female Maltese dog. Histologically, the tumor showed a wide trabecular pattern and was frequently accompanied with vascular lake formation. Tumor cells were positive for cytokeratin and neuron specific enolase, but negative for chromogranin. Electronmicroscopically, tumor cells were accompanied with continuous basement membrane and had poorly developed desmosomes. Sinusoidal endothelia had fenestration and were surrounded by myofibroblast-like cells. To the best of our knowledge, this paper is the first report of morphological studies on canine hepatoblastoma.

Alteration of anionic sites in renal glomerular basement membrane of pigs

Ultrastructural alteration of anionic sites (ASs) in the glomerular basement membrane (GBM) was studied in 10 cases of swine mesangial proliferative glomerulonephritis using a cationic ultrastructural tracer, 0.5% polyethyleneimine (M.W. = 1,800). Glomerular ASs were seen as discrete electron-dense particles in the GBM, mesangial matrix and epithelial cell surfaces by electron microscopy. In the lamina rara externa (LRE) of the normal GBM, ASs were distributed regularly in a single layer. In those areas of the LRE that contained electron dense deposits or clusters of spherical microparticles (SMPs), however, a distinct reduction or loss of ASs was observed in all the pigs. Quantitative assessment of ASs in the LRE over 1,000 nm of the GBM revealed a significant reduction in ASs in one case with diffuse global thickening of the GBM as compared with the remaining nine pigs without GBM thickening (P < 0.001, Mann-Whitney's U-test). There were no ASs in the lamina densa (LD) of the normal GBM, but an irregular distribution of ASs was seen within the LD of the pig showing diffuse global thickening of the GBM. These results suggest that a disturbance of the charge-selective barrier in the GBM may be induced by electron-dense deposits or SMPs, in the LRE as well as thickening of the GBM in swine glomerulonephritis.

Morphological and immunohistochemical studies on porcine serum-induced rat liver fibrosis

In order to clarify the pathogenesis of porcine serum (PS)-induced rat liver fibrosis, three experiments differing in dose of PS or duration of treatment were performed on male Fischer 344 rats. The rats were given an intraperitoneal injection of PS twice a week for 3 to 16 weeks and euthanized 7 days after the last injection for each treatment group. Liver tissues from these animals were subjected to detailed morphological and immunohistochemical examinations. Biochemical tests on treated rat serum revealed an increase in globulin concentration but no elevation in AST, ALT and ALP activities. There were no relationships among the dose of PS, the extent of fibrosis, and the anti-PS antibody titer. A number of alpha-smooth muscle actin-positive non-myofibroblastic cells, desmin-positive cells, and lipofuscin-laden Kupffer cells were found around the central veins and in the fibrous septa. In advanced stages of fibrosis, a proliferation of elastic fibers were observed in the septa. These findings were considered to indicate gradually occurred hepatocellular necrosis. The vascular endothelial cells in the fibrous septa expressed factor VIII-related antigen, exhibited fenestration accompanied by basement membrane formation, and were surrounded by Ito cells. Most of the portal vein branches showed hypertrophic thickening of the smooth muscle layer, resulting in narrowing of the lumen. These vascular changes suggested that hemodynamic alterations of the intrahepatic circulation induced hepatocellular necrosis/apoptosis and played an important role in the pathogenesis of porcine serum-induced liver fibrosis in rats.

Hemangiopericytoma of the sigmoid mesentery: report of a case with immunohistochemical findings

Hemangiopericytoma has been described in various sites in the body but only rarely in the mesocolon. This report describes the clinical course of an 83-year-old man whose mesosigmoidal tumor (hemangiopericytoma) was resected on 11 November 1994. Immunostaining was done with the following primary antibodies: alpha-actin, vimentin, factor VIII-related antigen, chromogranin, and S-100. Staining for factor VIII-related antigen was strongly positive in the endothelial cells of the capillaries, but negative in the tumor cells. The tumor cells contained immunoreactive vimentin, but demonstrated no alpha-actin, chromogranin, or S-100. Since the operation, the patient has been disease-free for 11 months.

[Reversible changes of cranial MRI in a girl with SLE]

The 11-year-old girl had hypertension and generalized tonic-clonic convulsions during the steroid pulse therapy. Her cranial T2-weighed MRI showed small areas of high signal intensity in the right occipital lobe. Her neurological findings were normal. After 2 months of steroid pulse therapy, multiple high signal intensities were demonstrated on T2-weighed MRI. After 5 months of the therapy, however, only a small T2-weighed MRI spot of high signal intensity in the white matter was observed, and the multiple lesions disappeared. On follow up, she did not show any neurological defects. It is postulated that not only steroid pulse therapy-induced hypertension but also SLE-induced angiopathy caused such flexible lesions. According to the literature, these lesions can be considered to be edema around small vessels. Such MRI findings have been reported in adult patients with SLE, but to our knowledge there have not been reports on children with SLE.