Satoshi Takasaki

Three-dimensional observations of the human hepatic artery: (Arterial system in the liver)

BACKGROUND/AIMS We examined the three-dimensional structures of the hepatic artery. MATERIALS/METHODS A 39-year-old man who died of brain hemorrhage was autopsied. The liver was perfused with physiological saline and 20% formalin from the hepatic artery and portal vein. More than 700 serial sections were obtained from a paraffin-embedded block, and vascular reconstruction was performed under a light microscope. RESULTS The hepatic artery divides into the axial artery and the peribiliary branch given off from it. These two systems also connect to each other by a few anastomoses. The former systematically supplies arterial blood to all the parenchymal liver cells. The latter forms two layers of plexes around the bile duct. The inner capillary layer is afferent and the outer vascular layer is efferent to the bile duct. CONCLUSION To maintain constant sinusoidal blood flow, the terminal portions of the axial arteries may contract and thereby divert blood to peribiliary branches through bifurcations and anastomoses. The blood flow of the peribiliary capillary plexus may affect bile flow. The hepatic artery may act as a functional mediator between portal flow and bile excretion.

Stereoscopic scanning electron microscopy of the red pulp of dog spleen with special reference to the terminal structure of the cordal capillaries

SummaryIn order to obtain direct morphological information about the three-dimensional fine structure of the splenic terminal vascular bed, especially the terminating mode of the cordal capillaries, stereoscopic scanning electron microscopy of perfusion-fixed and freeze-fractured red pulp of a normal dog spleen was undertaken.An improved method of perfusion-fixation was utilized in which the hydrostatic pressures of the splenic artery and vein were maintained at approximately the same levels as those in the living state. Stereoscopic observations of scanning electron micrographs clearly demonstrated the three-dimensional fine architecture of the splenic sinuses, the spongy cordal reticular tissue and the intracordal vasculature.The cordal capillaries terminate in the labyrinthine cordal space according to a certain mode in which the walls of the terminals are transformed into a meshwork structure continuous with the cordal reticular tissue owing to an increase in number and size of fenestrations. No evidence could be detected to prove or suggest any direct continuity of the capillary end with the splenic sinus. These results strongly support the concept of an “open circulation”, at least in the red pulp of the dog spleen, with the possibility of a “functionally closed circulation” under some physiological conditions.

A pathological study on eosinophilic lymphfolliculoid granuloma (Kimura's disease).

The present study Included 46 cases of eosinophilic lymphfolliculoid granuloma(Kimuras disease), which occurred mainly in males between the ages of 11 to 52 years. The common sites were the soft tissue of the head and neck region. Although recurrence was not infrequent, the clinical course was benign. Laboratory findings revealed eosinophilia and frequent elevation of serum IgE. The histological characteristics consisted of proliferation of lymphoid follicles and granulation tissue with infiltration of eosinophils, mast cells, plasma cells, lymphocytes, and histiocytes, some degree of vascular proliferation, and fibrosis. With the appliance of unlabeled peroxidase‐antiperoxidase method, a marked reticular reaction of IgE was confirmed in the germinal center of the folliculoid structure, and there were quite a number of IgE producing plasma cells. Many mast cells with IgE bound to their cell surface were seen in the granulation tissue. Toluidine blue staining and electron microscopy revealed fairly well preserved granules in mast cells, being quite different from the changes seen in type I allergy.

Histopathologic Diagnostic and Histogenetic Problems in Malignant Soft Tissue Tumors

More than 10 years have passed since immunohistochemistry was introduced with the expectation of enabling reliable objective differential diagnosis in soft tissue tumors difficult to diagnose on light microscopic examination, and of the analysis of the cell origin of tumors of unknown histogenesis. At present, much immunophenotypic information can be obtained on routine surgical pathology of soft tissue tumors and one can ascertain the diagnosis with objective evidence on many occasions. On the other hand, newly obtained findings may give rise to other diagnostic or histogenetical problems. For example, malignant fibrous histiocytoma, the concept of which was first proposed by OBrien and Stout (1) in 1964 and supported by many investigators (2-10) after that, is now regarded as a definite clinicopathologic entity. However, this is still a controversial tumor in terms of its differential diagnosis (1 1, 12) and histogenesis even after extensive ultrastructural (1 3-1 7), immunohistochemical(l8-22) and xenograft studies (23, 24). Interesting but difficult problems in interpret-

Three-dimensional observations on the alterations of lobular architecture in chronic hepatitis with special reference to its angioarchitecture for a better understanding of the formal pathogenesis of liver cirrhosis

For a better understanding of the formal pathogenesis of liver cirrhosis, the angioarchitecture of the liver lobule in chronic viral hepatitis was investigated three dimensionally. The histological reconstruction method, using serial histological sections, was adopted for the three-dimensional observation. Histology of the case showed chronic active hepatitis with occasional fibrous bridging of the portal to portal tract or hepatic vein. Graphic reconstructions revealed various degrees of altered angioarchitecture from place to place. While the conducting portion of the portal vein was almost preserved, the pathological changes mostly began at the parenchymal portion, especially second step or subsequent branches of the portal vein. In general, portal vein branches showed damage such as stenoses, disappearance, an increase and decrease in number and distorted spatial arrangements. Even in less damaged portal tracts, portal veins showed such changes to some extent. In severely damaged places with bridging fibrosis, a normal lobular angioarchitecture was completely lost; instead, portal veins, arteries and hepatic veins were tangled with each other. Parenchymal nutrition was suggested to be dependent on the remaining third-step portal branches or newly formed ones. However, the hepatic vein system had a tendency to be preserved and distributed fluently in the parenchyma. The distortion of these portal vessels indicated various degrees of loss of the lobular architecture. In conclusion, it is suggested that an early histological sign of cirrhosis develops in the course of chronic hepatitis.

Lymphocyte Subsets in The white Pulp of Human Spleen in Normal and Diseased Cases

The distribution of T and B‐lymphocytes and their subsets in the white pulp of human spleens extirpated from patients with cancer of the digestive tract and those with portal hypertension was examined with the appliance of monoclonal antibodies. T‐lymphocytes were distributed in the core of lymphatic sheath protuberance (Matsumoto), while the mantle zone of lymphatic nodule and germinal center were solely occupied by B‐lymphocytes. On the other hand, both T and B‐lymphocytes were found in the cortical zone of lymphatic sheath protuberance and outer and inner layer of lymphatic nodule. The ratio of both cells differed from one case to the other. The majority of T‐lymphocytes in the core of lymphatic sheath protuberance and those localized in the light region of germinal center were helper T cells. Although the lymphatic sheaths in cases with portal hypertension were narrower than those in the controls, there was no difference in the distribution density of T cells between the two groups. Hardly any B‐lymphocytes were found in the cortical zone of lymphatic sheath protuberance, while the mixture of T‐lymphocytes tended to become prominent in the outer and inner layer of lymphatic nodule in those cases.

MORPHOLOGICAL AND BIOCHEMICAL ALTERATION IN THE RAT LIVER INDUCED BY MAPROTILINE

The fatty change in the liver induced in male rats by a new antide‐pressant, maprotiline, given at high‐dose was studied morphologically and biochemically.

Autoimmune forms of chronic hepatitis associated with hepatitis C virus (HCV) infection with and without HCV-RNA: Histological differences from pure autoimmune hepatitis and chronic hepatitis C

Liver biopsy specimens of pure autoimmune hepatitis (pAIH), autoimmune forms of chronic hepatitis with positivity for anti‐hepatitis C virus (anti‐HCV) and negativity for HCV‐RNA (cAIH‐RNA(–)), autoimmune forms of chronic hepatitis with positivity for anti‐HCV and HCV‐RNA (cAIH‐RNA(+)), and chronic hepatitis C (CHC) were compared histologically and statistically to clarify the histological character of the autoimmune form of chronic hepatitis with HCV infection. The following representative histological features were used to investigate: inflammation, fibrosis, plasma cell infiltration, lymphoid aggregates/follicles, non‐suppurative destructive cholangitis, and the shape of the enlarged portal tracts. While a considerable overlap in histological features between the pAIH and cAIH‐RNA(–) groups and between the CHC and cAIH‐RNA(+) groups was recognized, the overlap between the pAIH and CHC groups was small. Significant differences were found between cAIH‐RNA(–) and cAIH‐RAN(+) groups, especially in necroinflammatory findings. In conclusion, most cases of cAIH‐RNA(–) with histological features similar to those of pAIH were shown to be AIH. The remaining cases might be CHC with subsidence of viral duplication. Conversely, many cases of cAIH‐RNA(+) with histological findings similar to those of CHC were shown to be CHC clinically mimicking pAIH. The remaining cases might represent coexistence of pAIH and HCV infection.

A autopsied case of hypercitrullinemia in adult caused by partial deficiency of livcr arginosuccinate synthetase

46歳の男性で,反復する意識障害,高アンモニア血症,高シトルリン血症などの臨床所見を示しながら,明らかな肝機能障害や門脈大循環短絡を認めない1症例を経験した.剖検にて類瘢痕型肝脳疾患の病理診断を得,また剖検肝および腎にて尿素サイクル酵素系の酵素化学的検討を行い,本症例の病因が,肝Arginosuccinate Synthetase活性の低下であることを明らかにし,本症の病因と病態に関して文献的考察を行った.

In the non-cirrhotic stage of nonalcoholic steatohepatitis, angioarchitecture of portal veins and lobular architecture are maintained

The morphogenesis of lobular restructuring to liver cirrhosis in nonalcoholic steatohepatitis (NASH) is yet to be clearly understood. Therefore, we observed tissue samples from three biopsies and one autopsy with NASH in the non-cirrhotic stage three-dimensionally to elucidate the evolution of fibrosis and the changes of angioarchitecture. Histologic reconstructions revealed that pericellular fibrosis developed around the central vein in the early stage and gradually progressed to arch-shaped band-like fibrosis connecting the central veins in the neighboring lobules. In contrast, the basic angioarchitecture of the portal vein in the portal tracts tended to be preserved in the non-cirrhotic stage, although the portal vein architecture was slightly altered as the portal tract underwent gradual fibrous expansion. In addition, a striking development of arteries originating from the portal tract was found in the fibrotic area around the central and sublobular veins. In summary, while central–central bridging fibrosis and ectopic arterial development were conspicuous, the lobular architecture was maintained relatively well in the non-cirrhotic stage of NASH because of only mildly damaged angioarchitecture of the portal veins. The process of lobular restructuring in NASH is considered to be different from that in chronic viral hepatitis in the non-cirrhotic stage.