Kaoru Aihara

Experimental studies of moderate temperature burns

The pathology and characteristics of moderate temperature burns have been investigated in rats with a heating apparatus capable of applying thermal doses varying in temperature and exposure time, to which the responses have been observed both macroscopically and microscopically. The macroscopic examination showed only erythema and greyish necrosis. The microscopic changes were divided into six grades of severity from 0 to 5. From the time-temperature threshold curves made by microscopic observations, the critical temperatures for superficial and deep dermal burns, and full skin thickness burns were 37.8 degrees C, 41.9 degrees C and 47.9 degrees C, respectively. According to the data, almost all commercially available topical heaters are considered hazardous. Susceptibility to thermal injury was markedly increased by compression and ischaemia, the effects of which are thought to be due mainly to rapid heat accumulation (heat damage) and hypoxaemia (hypoxic damage).

Silver staining of nucleolar organizer regions in prostatic lesions

Variations in the number of silver‐stained nucleolar organizer region‐associated proteins (AgNORs) were studied in paraffin sections of 42 benign prostatic lesions, comprising four cases of granulomatous prostatitis, five of squamous or transitional metaplasia, eight of atypical and 25 of regular hyperplasia, and 37 of prostatic adenocarcinoma, with their metastases. There was a significant difference between the mean AgNOR counts of the benign and malignant prostatic lesions (1.58±0.26 v. 4.34±1.53; P<0.01). The mean AgNOR counts significantly increased with increasing Gleasons grade (P<0.01) and clinical stage (P<0.05) of the tumours. AgNOR counting may contribute to the conventional diagnostic and prognostic indices of cancer of the prostate.

A Histological, Ultrastructural and Immunohistochemical Study of Superficial Temporal Arteries and Middle Meningeal Arteries in Moyamoya Disease

Pathologic changes in superficial temporal arteries (STA) and middle meningeal arteries (MMA) biopsied from 15 patients with moyamoya disease (MD) who had undergone cerebro temporal arterio synangiosis were studied histologically, ultrastructurally and immunohistochemically. The main pathologic features were: proliferation of smooth muscle cells (SMCs) and thickening of the intima, degeneration and destruction of SMCs in the media and intima, and the presence of condensed organelles in necrosed SMCs or the interstitium among SMCs, or both outside and within the elastica interna (El). The El had become thin, porous, fragmented and was even absent in some segments. These changes are different from those of other forms of angiopathy, but identical with those at the ends of internal carotid arteries (ICA) reported by us previously, being pathognomonic for MD. These changes in the STA and MMA reveal that MD involves not only the ICA but also the intra and extracranial branches of external carotid arteries. The medial necrosis of SMCs seems to be the primary injury of the arterial wall in MD. STA tissue blocks from two cases of MD were stained immunohistochemically. By electron microscopy, IgG, IgM, and C3 positive granules were observed on the ER of endothelial and intimal cells. Further studies on more cases are needed to determine whether an immunoreaction has occur ed in these arteries. Acta Pathol Jpn 41: 521 530, 1991.

RENAL AND PULMONARY VASCULAR CHANGES INDUCED BY CROTALARIA SPECTABILIS IN RATS

Some species of the plant Crotalaria spectabilis widespread in pastures in the United States have been suspected as responsible for incidental deaths of farm animals since the late 19th century. Since 1934, attention has gradually been focused upon the toxicity of the species Crotalaria spectabilis, Rothl ) or its. principle ingredient, the extracted alkaloid, Monocrotalinez). In the previous reports of the postmortem findings on either natural or experimentally induced cases of poultry, domestic animals or cattles following ingestion of Crotalaria spectablilis seeds or Monocrotaline, the main pathological alterations observed were pulmonary edema and hemorrhage, pulmonary thrombosis, bronchial hyperplasia and hepatic hemorrhage, necrosis or cirrhosis3~ 4 51 61 77 *! D * 10). Recently, LALICH and his associates77 8~ 9) descrihed pulmonary arteritis of the medium and small sized arteries in Crotalaria spectabilis or Monocrotaline fed Sprague-Dawley rats, and BERRY et al.4) pointed out the hepatic vein occlusion of the liver in cows and horses. However, certain morphological features of the kidney, especially glomerubr capillary thrombosis, have hitherto received little attention. Our interest so far has been concerned on the peripheral vascular damages and their influences upon permeability. The reports concerning administration of alkaloid-containing plant seeds such as Crotalaria spectabilis which could produce organic peripheral vascular changes were rather scanty. Our main intention was to reproduce the vascular changes in rats by feeding Crotalaria spectabilis seeds and to examine the distribution and severity of the morbid processes and angio-

Effects of lactoferrin on iron absorption in immature mice

Abstract The effects of lactoferrin (LF) on iron absorption in weanling (2 week-old) mice fed different amounts of iron salt for a long term (1–2 weeks) were investigated in comparison with adult mice. Hepatic iron levels in weanling mice fed a diet containing excess iron (25mg Fe/100g diet) without LF were extremely high compared with those of LF-fed mice. However, the hepatic iron levels in adult mice (4 weeks old) fed excess iron were not affected by ingested LF. When the weanling mice were fed the iron excess diet for one week and then orally administered a single dose of 59 FeLF (0.33 μCi /mouse), the levels of 59 Fe remaining in the blood and liver decreased within one week to levels lower than those observed in groups fed the same diet and administered 59 Fe without LF. These results indicate that the administration of LF to iron overloaded weanling mice inhibited iron absorption. Electron microscopic analysis revealed that endocytosis of massive amounts of iron into the premature enterocytotic system led to vacuole formation in the region of the intercellular junction of epithelial cells.

Pararectal rhabdomyosarcoma: Report of a case

Primary rhabdomyosarcoma of the alimentary tract is extremely rare, only 11 cases have been reported in the literature. Long-term survival in adults may be possible if the tumor is detected at an early stage even though it is asymptomatic. This highly malignant tumor can be treated by surgical excision, chemotherapy, and irradiation. A 12th case—of stage 1, pararectal, rhabdomyosarcoma—is reported.

Silver-stained nucleolar organizer regions in hypertrophic and keloid scars.

Silver-stained nucleolar organizer regions (AgNORs) have been widely used as a marker of cellular activity and proliferation. In a retrospective study, we investigated the potential value of AgNORs in 12 hypertrophic and 24 keloid scar tissues. Ten normal skin tissues served as controls. A standard silver-staining method was used, and the mean AgNOR count of dermal fibroblastic cells in each tissue was determined. In normal skin, the mean AgNOR count of dermal fibroblasts was 1.79+/-0.55, whereas fibroblastic cells in hypertrophic and keloid scars had mean AgNOR counts of 3.18+/-0.56 and 5.10+/-0.97, respectively. There was a statistically significant difference between the mean AgNOR counts of fibroblastic cells from normal skin, hypertrophic scar, and keloid scar [one-factor analysis of variance (ANOVA), p < 0.0001]. Our findings suggest that AgNOR count may be a useful marker for assessment of fibroblastic cell activity in hypertrophic and keloid scars, which may have potential value for histologic and biologic characterization of the two lesions.

Combined immunohistochemical study of tissue polypeptide antigen and cancer antigen 125 in human ovarian tumours

An indirect immunoperoxidase method was used to study the expression of tissue polypeptide antigen (TPA) and cancer antigen 125 (CA 125) in 47 benign and malignant ovarian tumours. Tissue polypeptide antigen and CA 125 antigen were expressed respectively in 22 (73%) and 16 (53%) of the 30 adenocarcinomas and in five (29%) and four (23%) of the 17 benign tumours. Co‐expression of TPA and CA 125 antigen occurred in 12 (40%) malignant and four (23%) benign tumours. Ultrastructurally, TPA and CA 125 antigens were located at the cell surface and microvillous surfaces.

Early changes in the arterial endothelium under various pathological conditions: an electron histochemical study with visualization of altered permeability using electron microscopic tracers.

The authors have studied the endothelial changes in the aorta and the arteries of heart, kidney and other organs in cholesterol fed rabbits and endotoxin administrated rats through electron histochemical and vascular clearance methods. The vascular changes are variable presumably due to the functional and morphological difference of vessels. The administration of cholesterol and endotoxin may result in increased vascular permeability which is directly related to the qualitative increase and decrease of hydrolytic enzymes in the vascular wall. The permeability of high molecular substances was enhanced with the widening of the intercellular space in contraction of endothelium and the changing of molecular structure of plasma membrane accompanied with plasma lipid, platelets and hemodynamic stress. This fact was confirmed by use of horseradish peroxidase and dextran fesin as tracers of different molecular sizes. The authors emphasize that direct injury and subsequent abnormal contraction of the endothelial cell may initiate increased permeability of plasma protein and lipid in the medial layer and eventually may develop and enhance arteriosclerosis.

Formation of the cardiac vascular system and ventricular compact wall

The corrosion cast method for scanning electron microscopy, transmission electron microscopy and auto-injection of tracers for light microscopy were used to examine the cardiac coronary development and the forming of the ventricular compact wall to the embryonal sponge-work wall. Our observations suggest that the coronary artery first extends over outer layer, and later over middle and inner layers. As intertrabecular spaces are closed by fusion to each endocardium in the inner layer position, the veins are formed by the remaining expanded sinusoidal intertrabecular spaces. The capillaries of the coronary vessels are then connected to the veins to finally complete the cardiac vascular system.