Subepithelial fiber components of the round window membrane of the guinea pig: an ultrastructural and immunohistochemical study

Subepithelial fiber components of the round window membrane (RWM) of the guinea pig were studied by the following methods: transmission electron microscopy (TEM), scanning electron microscopy (SEM) with NaOH treatment, high-voltage electron microscopy (HVEM) and immunohistochemical staining. SEM observation revealed intersecting collagen fibers and a vascular network in the middle layer. TEM observation showed that at the attachment region to the bone fibroblasts, collagen fibers and elastic fibers were intermingled with each other, and mesenchymal cells (bone-lining cells) were scattered on the surface of the bone. The cytoplasmic processes of fibroblasts and bone-lining cells were connected by interdigitations. HVEM demonstrated that collagen fibers of the RWM were directly linked to the fibers of the bone matrix. Immunohistochemically, the middle layer was positive for antibody to type I collagen. Immunoreaction for fibronectin was also positive at the middle layer and most intense in the region attached to the bone. Thus, the RWM is securely attached to the bone by type I collagen fibers together with the bone-lining cells and fibroblasts.

Primary malignant mesenchymoma of bone: case report, literature review, and distinction of this entity from mesenchymal and dedifferentiated chondrosarcoma

The seventh case of primary malignant mesenchymoma of bone is reported. It is compared to the other six cases in the literature and clinicopathologic pattern of this entity is developed. Primary malignant mesenchymoma of bone is compared to mesenchymal chondrosarcoma and dedifferentiated chondrosarcoma. Differences as well as similarities are discussed and a more current classification scheme for malignant mesenchymoma of bone is proposed.

[Tissue type plasminogen activator (t-PA) and plasminogen activator inhibitor (PAI) in transplanted kidneys]

We have studied the involvement of fibrinolysis in acute rejection after kidney transplantation by analyzing changes in urinary levels of substances such as FDP, D-dimer, tissue plasminogen activator (t-PA) and plasminogen activator inhibitor (PAI). Fibrinolytic activity was found to be low (that is, PAI is dominant) during acute rejection, and it was elevated (that is, PA became dominant) as acute rejection subsided. It appears that the dominance of PA leads to an increase in the products of fibrinolysis and an elevation in the D-dimer/FDP ratio, resulting in disappearance of the acute rejection. Based on these findings, we thought it necessary to administer t-PA to kidney recipients so that PA becomes dominant earlier and the acute rejection can be reduced. It is necessary for us to directly study the phenomena within the kidneys. Therefore, we recently conducted a histochemical study of the distribution of t-PA, Urokinase type PA (u-PA) and PAI in transplanted kidneys. Transplanted kidney, which functioned well or showed signs of acute or chronic rejection, were biopsied. These renal samples as well as control samples (biopsied from normal nongrafted kidney) were examined as to distribution of t-PA, u-PA and PAI by the indirect enzyme complement method. In conclusion, t-PA, u-PA and PAI were detected in the glomeruli, arterioles, tubule and interstices of the control kidneys, well functioning grafts, acutely rejected grafts chronically rejected grafts. All samples showed intense chromatic responses in the arterioles and part of the tubules. On the whole, the chromatic response tended to be more intense in the acute rejection group than in the other group.

Effect of 24 weeks of treatment with epalrestat, an aldose reductase inhibitor, on peripheral neuropathy in patients with non-insulin-dependent diabetes mellitus

The effects of treatment with epalrestat, an aldose reductase inhibitor, on peripheral neuropathy were studied in 45 patients with non-insulin-dependent diabetes mellitus (NIDDM). Epalrestat 150 mg three times daily was given for 24 weeks. Subjective symptoms, such as spontaneous pain in the lower extremities and numbness and hypoesthesia of the extremities or trunk, were significantly (P < 0.001) relieved after 12 and 24 weeks of epalrestat treatment. Vibratory perception thresholds, as measured by using a tuning fork (C-128) and a vibrometer, were improved after 24 weeks of treatment. Furthermore, there were no adverse effects on glucose or lipid metabolism during treatment. These results suggest that long-term (24-week) epalrestat therapy can be used effectively to treat peripheral neuropathy in NIDDM patients without affecting glucose or lipid metabolism.

Hepatocyte growth factor stimulates liver regeneration and elevates blood protein level in normal and partially hepatectomized rats

The effects of recombinant human hepatocyte growth factor (HGF) on liver growth and function of normal and partially hepatectomized rats have been examined. HGF was continuously administered into the jugular vein because it was rapidly eliminated from the plasma (t1/2 alpha; approximately 4.5 min) and degraded. In normal rats, the labeling index of hepatocytes was increased about 6 times by the administration of HGF. HGF also decreased the prothrombin time and increased the hepaplastin and serum albumin content. In 70%-hepatectomized rats, HGF stimulated liver regeneration and increased the level of blood proteins such as hepaplastin in a dose-dependent manner. The stimulation of serum protein level seemed to result from not only the increase of hepatic cell number but also the direct effect of HGF on the protein production in hepatocytes, because HGF rapidly enhanced the protein synthesis prior to the increase of cell number and increased the mRNA content of albumin in the liver in vivo. In addition, a combination of heparin with HGF further accelerated the effects of HGF described above, possibly due to the decrease of HGF clearance. These findings suggest that HGF accelerates both the hepatic regeneration and function in vivo, and that rhHGF is clinically expected to be a potent therapeutic agent in hepatectomy and liver injury.

The Pringle maneuver induces only partial ischemia of the liver

It has been questioned whether the Pringle maneuver induces complete ischemia of the liver. We examined changes in liver blood flow (LBF) in sixty patients who underwent liver resection, under conditions of prolonged inflow occlusion. The ischemia period ranged from 30 to 75 minutes. All patients tolerated the procedure. To better understand the metabolic consequences of ischemia, 10 female mongrel pigs were divided into two groups treated with hepatic inflow occlusion or total vascular exclusion for one hour (n = 5, each). Clinical and experimental data showed approximately 10% of residual LBF under the Pringle maneuver. Only one out of five animals tolerated complete ischemia (total vascular exclusion) in terms of 7-day survival while all pigs treated with the Pringle method survived. This was attributed to the lower serum transaminase levels and attenuation of liver adenosine triphosphate (ATP) decline in the inflow-occluded group. Our data indicate that the Pringle maneuver induces partial rather than full ischemia of the liver and hepatic vein "back flow" is likely to be the cause. The clinical implications of hepatic inflow occlusion for liver surgery are discussed.

Tolerance of chronically-diseased liver to prolonged hemihepatic ischemia during hepatectomy

Seventeen patients with chronic liver disease underwent prolonged warm ischemia of hemi-lobe during liver resection. Those included 15 cirrhotic patients and two with chronic hepatitis. The hemi-hepatic ischemia was carried out with a liver clamp. The normothermic liver ischemia time of 40 to 70 minutes (53.8 +/- 10.4 minutes, mean +/- SD) were tolerated well with an acceptable postoperative course and no mortality. The liver with cirrhosis or chronic hepatitis can tolerate a hemi-hepatic ischemia of up to 70 minutes for patients with no high-risk factors.

Ultrastructure and three-dimensional imaging of epimyoepithelial islands in benign lymphoepithelial lesions

Benign lymphoepithelial lesions of the salivary glands associated with Sjögren's syndrome are characterized by extensive infiltration of lymphoid cells, atrophy of acini and the presence of so-called epimyoepithelial islands. This report describes ultrastructural and three-dimensional reconstructive studies of epimyoepithelial islands performed at Tokyo Women's Medical College. Ultrastructural examination showed that these islands are composed mainly of epithelial cells containing intermediate filaments and/or tonofilament bundles, scattered lymphocytes and plasma cells. Myoepithelium-like cells containing myofilaments were sometimes found in the peripheral portion of the myoepithelial islands. Also, mitotic figures were rarely found in these islands. Three-dimensional reconstructive study revealed that the epimyoepithelial islands are not isolated cell clusters but are continuous hypertrophic duct-like structures. These results suggest that the epimyoepithelial islands are derived from proliferating duct epithelial cells, especially those of large peripheral ducts.

Carcinoma ex pleomorphic adenoma of the soft palate

A case of carcinoma ex pleomorphic adenoma arising in the soft palate is reported. The tumour presented had enlarged gradually over 10 years and finally occupied the oral cavity. The patient was admitted to our hospital due to disturbance of her speech and swallowing, and a sudden haemorrhage from the tumour. The initial pathological diagnosis by open biopsy was benign pleomorphic adenoma. After total resection, histological examination revealed that the tumour was composed partly of benign pleomorphic adenoma and partly of an adenocarcinomatous component. The carcinoma cells with prominent nucleoli were spheroid or polygonal in shape, and frequently formed ductal structures with areas of necrosis. Mitoses were also found. These findings showed that this tumour was a secondary carcinoma which had developed in a preexisting pleomorphic adenoma.

A study of cysts in the oral region. Cysts of the jaw

Clinical cases of cysts of the jaw treated in the Department of Oral Surgery of our university during the 10 y between 1980 and 1989 were studied clinically. Patients with radicular cyst, dentigerous cyst, odontogenic keratocyst and postoperative maxillary cyst, which were found at relatively high frequencies, were further analyzed with regard to age, sex and anatomical distribution. A diagnosis of cyst was established in 1,444 patients during the above period, and 1,234 (85.5%) of them had cysts of the jaw. According to a pathological classification by Ishikawa's method, these patients included 509 (41.2%) with radicular cyst, 259 (27.0%) with dentigerous cyst, 95 (7.7%) with odontogenic keratocyst and 267 (21.6%) with postoperative maxillary cyst. The pattern of age distribution in cases of radicular cyst, odontogenic keratocyst and postoperative maxillary cyst was similar to that found in previous studies. Among patients with dentigerous cyst, those aged under 20 y accounted for about 60%. Radicular cyst occurred most frequently in the maxillary lateral incisors, dentigerous cyst in the mandibular wisdom teeth, and odontogenic keratocyst in the region between the mandibular molar and the ramus of the mandible.

Endothelium-dependent relaxation in response to adenosine diphosphate is impaired under poor runoff conditions in the canine femoral artery

To examine whether poor distal runoff conditions of the canine femoral artery modulates endothelium-dependent relaxations, we developed a poor distal runoff limb in the canine right femoral artery (poor runoff group). The left femoral artery was used as a control. Endothelium-dependent responses were examined in vitro. The rings of femoral artery were obtained from dogs pretreated with 6 weeks of poor distal runoff. In the control, flow rate and tau-variation were 79.1 ml/min and 214.2 dynes/cm2, respectively. In the poor runoff group, the flow rate and tau-variation were 27.4 ml/min and 52.7 dynes/cm2. There were significant differences between the two groups. In the rings taken from the control group contracted with norepinephrine, adenosine diphosphate (ADP) and A23187 caused endothelium-dependent relaxations. In the poor runoff group, the endothelium-dependent relaxations in response to ADP were impaired, while A23187 caused comparable endothelium-dependent relaxations. Direct relaxations in response to sodium nitroprusside were comparable between the two groups. These experiments indicate that under poor runoff conditions, the endothelium-dependent relaxations to ADP are impaired without changing the properties of the smooth muscle cells. This dysfunction of the endothelium under conditions of abnormal flow may accelerate a loss of late patency of the reconstructed arteries.

Severe mitochondrial cardiomyopathy and extra-neuromuscular abnormalities in mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episode (MELAS)

An autopsy case of mitochondrial encephalomyopathy, lactic acidosis and stroke-like episodes (MELAS) in a 56 yr-old woman is reported. Histopathologic abnormalities are shown widely in the heart, liver, kidney, pancreas and thyroid gland, other than the central nervous system and skeletal muscles that had been so far emphasized in the cases of MELAS. Particularly in the myocardium, focal fibrosis and a disarray of myofibrils were demonstrated, which closely resembled that seen in idiopathic hypertrophic cardiomyopathy. In addition, unique mitochondrial abnormality exhibiting a central glycogen aggregation with surrounding multiple radiating cristae was noted in some cardiomyocytes, which has never been reported in previous cases of MELAS. Thus, in MELAS, various histopathological abnormalities including the mitochondrial abnormalities may involve tissues other than those of the neuromuscular system.

Eliminating effects of an air purifier on infectants during dental procedure

Blood and drill dust from dental plaque microorganisms, teeth, and filling materials can cause environmental pollution in the dental clinic. Currently, as a preventive measure against air pollution from a patient's mouth during dental treatment, dust-collecting aspirators such as an extra-oral vacuum aspirator (EOVA) are coming into general use. We tested the eliminating effects by the EOVA with the plaque solution aerosol and the aerosol from drilling a tooth by examining the distribution of floating aerosol in the air turbine's tank when a plaque solution was sprayed and when a human tooth was drilled with a plaque solution. We concluded that infectious aerosol increases in diameter with the drilling of human teeth to the size of about 0.5-5.0 micrometers, which is microbiologically and hygienically hazardous and also can be inhaled without much difficulty.

Comparison of endothelial function between in situ and reversed vein graft: differences in endothelium-dependent responses

BACKGROUND

The endothelium releases endothelium-derived relaxing factors that are potent vasodilators and inhibitors of platelet aggregation. Experiments were performed to determine whether the endothelium-dependent responses differed between in situ and reversed vein grafts. The influence of valve disruption or of dissection of the adventitia was also examined.

METHODS

Segments of canine jugular veins were grafted into the carotid arteries during procedures such as reversed grafting, in situ grafting with valve disruption, in situ grafting without valve disruption, and in situ grafting with dissection of adventitia. After 4 weeks the endothelium-dependent responses of the grafts were examined by isometric tension recording.

RESULTS

In the reversed and in situ vein graft with valve disruption, acetylcholine caused endothelium-independent contractions, whereas in the in situ vein graft without valve disruption acetylcholine-induced endothelium-dependent relaxations were preserved. Adenosine diphosphate (ADP) caused comparable endothelium-dependent relaxations in the in situ vein graft irrespective of valve disruption. In the reversed vein graft ADP-induced relaxations were significantly impaired. In the in situ vein graft with dissection of the adventitia, relaxations in response to acetylcholine and ADP were significantly reduced.

CONCLUSIONS

These results suggest that endothelial function, in terms of endothelium-derived relaxing factors in the in situ vein graft, can be preserved and that adventitial dissection in the in situ vein graft should be minimized to preserve endothelial function.

Characterization of biliary epithelial cells isolated from needle biopsies of human liver in the presence of hepatocyte growth factor

Current methods for the isolation of intrahepatic biliary epithelial cells from human liver rely upon relatively large segments of tissue, thereby limiting studies to cells isolated from patients with end-stage disease. To investigate a greater range of diseases and those at an earlier stage, we have developed a method to isolate biliary epithelial cells from biopsy-sized fragments of human liver. Tissue explants are cultured for > 4 weeks, and, in approximately 50% of samples incubated with medium containing hepatocyte growth factor, biliary epithelial cells begin to migrate from the fragments and proliferate. With time they form confluent pavements of cells that express cytokeratin 19 and gamma-glutamyl transpeptidase and are negative for markers of non-biliary cell phenotype. After subculturing, cells can be expanded, yielding substantial numbers for subsequent study in vitro. Cells can be isolated with a similar degree of success from adult normal liver, from a variety of liver diseases, and from post-transplant liver biopsies. Overall, pediatric tissue yielded cells less frequently than adult tissue. This novel technique is likely to have a major impact on the study of biliary pathophysiology, as small fragments of tissue removed from biopsies taken for diagnostic purposes can be used.

The C-terminal 165 amino acids of the plasma membrane Ca(2+)-ATPase confer Ca2+/calmodulin sensitivity on the Na+,K(+)-ATPase alpha-subunit

The C-terminal 165 amino acids of the rat brain plasma membrane (PM) Ca(2+)-ATPase II containing the calmodulin binding auto-inhibitory domain was connected to the C-terminus of the ouabain sensitive chicken Na+,K(+)-ATPase alpha 1 subunit. Expression of this chimeric molecule in ouabain resistant mouse L cells was assured by the high-affinity binding of [3H]ouabain. In the presence of Ca2+/calmodulin, this chimeric molecule exhibited ouabain inhibitable Na+,K(+)-ATPase activity; the putative chimeric ATPase activity was absent in the absence of Ca2+/calmodulin and activated by Ca2+/calmodulin in a dose-dependent manner. Furthermore, this chimeric molecule could bind monoclonal IgG 5 specific to the chicken Na+,K(+)-ATPase alpha 1 subunit only in the presence of Ca2+/calmodulin, suggesting that the epitope for IgG 5 in this chimera is masked in the absence of Ca2+/calmodulin and uncovered in their presence. These results propose a direct interaction between the calmodulin binding auto-inhibitory domain of the PM Ca(2+)-ATPase and the specific regions of the Na+,K(+)-ATPase alpha 1 subunit that are structurally homologous to the PM Ca(2+)-ATPase. A comparison of the deduced amino acid sequences revealed several possible regions within the Na+,K(+)-ATPase that might interact with the auto-inhibitory domain of the PM Ca(2+)-ATPase.

Temporal bone findings in Cogan's syndrome

We report on the pathological findings in temporal bones taken from a 92-year-old man who had been diagnosed as suffering from Cogan's syndrome before death. Extensive endolymphatic hydrops was observed in the cochlea of the right ear. The saccule showed a collapse following intense dilation. Outpouching of the utricle and crus commune was found and the perilymphatic space of the posterior semicircular canal was occupied by the fibrotic tissue. The left ear showed neither hydrops nor fibrosis. There was absorption of the enchondral bone in both ears, but in the blood vessels there were no pathological changes.

Retroperitoneal Ewing's sarcoma

We report a case of extraskeletal Ewing's sarcoma arising in the retroperitoneal cavity. The tumor was excised en bloc with the left kidney and infiltrated portion of the left ureter. Histological diagnosis was confirmed by both electron micrography and immunohistochemical staining using a newly developed mouse monoclonal antibody 5C11, which specifically reacts with Ewing's sarcoma. An adjuvant chemotherapy T-11 regimen has been successfully preventing the recurrence.

Mechanical properties of human round window, basilar and Reissner's membranes

In order to measure the mechanical strength of small and delicate biological specimens, a microtesting system was developed. We measured the mechanical properties of the round window, basilar and Reissner's membranes taken from the autopsied cases. The testing method was a displacement of the specimen by a force sensor needle until rupture. A load-displacement curve was then drawn and the mechanical value of each specimen was calculated. Reissner's membrane was the weakest, though it showed a measurable strength. From the load-displacement curve of the basilar membrane, it could be displaced by a smaller force than the rupture strength of Reissner's membrane. Speculation about the concept of a negative summating potential in Meniere's disease is therefore theoretically possible from a mechanical point of view.