Light and electron microscopic analyses of immediate and late tissue damage caused by radiofrequency ablation in porcine liver

Radiofrequency ablation (RFA) is an effective procedure for localized hepatocellular carcinoma. Contrast-enhanced CT depicts the ablated area as a hypoattenuated area without hepatic blood flow; however, light microscopy does not show obvious necrosis in the ablated area. We evaluated liver tissue changes after RFA by light microscopy and electron microscopy. The normal livers of three anesthetized pigs were coagulated using RFA after laparotomy. The liver was examined immediately, and 1 week after operation by light and electron microscopy. After RFA, the liver parenchyma surrounding the needle electrode was brown in color and surrounded by a red marginal zone separate from the normal liver parenchyma. Hematoxylin-eosin staining of the central area did not show cell necrosis, and the structures of liver sinusoids, liver cell cord and the nuclei of hepatocytes were preserved. However, electron microscopic examination of tissue immediately after RFA showed destruction of mitochondria of hepatocytes and fixation of sinusoidal cells. One week later, there was a large quantity of debris in the enlarged sinusoids, in addition to irreversible destruction of hepatocyte organelles. RFA of the porcine liver causes hepatocyte damage. This damage was not evident by light microscopy but clearly identified by electron microscopy.     

Chromosome 1q terminal deletion resulting fromde novo translocation with an acrocentric chromosome

Summary Distal deletion of chromosome 1q has been reported in nearly 30 patients, all being associated with a deletion ranging from the 1q42 or q43 band to 1qter region. Here, we describe a girl with 1q terminal deletion resulting from an unbalancedde novo translocation t(1;D or G)(q44; p11), as revealed by the presence of a satellited feature and an NOR-stained region at the tip of 1q. We suggest that most of the phenotypic abnormalities seen in patients with 1q distal deletion are attributable to the monosomy for band 1q44.     

No allelic association between Parkinson's disease and dopamine D2, D3, and D4 receptor gene polymorphisms

Parkinson's disease is thought to be caused by a combination of unknown environmental, genetic, and degenerative factors. Evidence from necropsy brain samples and pharmacokinetics suggests involvement of dopamine receptors in the pathogenesis or pathophysiology of Parkinson's disease. Genetic association studies between Parkinson's disease and dopamine D2, D3 and D4 receptor gene polymorphisms were conducted. The polymorphism was examined in 71 patients with Parkinson's disease and 90 controls. There were no significant differences between two groups in allele frequencies at the D2, D3, and D4 dopamine receptor loci. Our findings do not support the hypothesis that susceptibility to Parkinson's disease is associated with the dopamine receptor polymorphisms examined. © 1994 Wiley-Liss, Inc.     

Clear cell hepatocellular carcinoma with abundant myxoid stroma.

A case of the clear cell variant of hepatocellular carcinoma with an abundant myxoid stroma is presented. The tumor occurred in a 55-year-old Japanese man, and swelling of the scrotum was the initial symptom. The patient underwent high-level orchiectomy, and the pathologic diagnosis was a metastatic tumor on the surface of the processus vaginalis and intact testis. Extensive examination failed to show a primary site. Subsequent autopsy revealed a large hepatic tumor and metastatic nodules with a prominent myxoid appearance in multiple organs. Histologically, each tumor consisted of uniform small tumor cells with clear cytoplasm attributed to abundant accumulation of glycogen particles, and an abundant myxoid stroma was also present. The tumor cells were positive for keratin, alpha 1-antitrypsin, alpha 1-antichymotrypsin, liver ferritin, prealbumin, and fibrinogen, but lacked alpha-fetoprotein. These findings indicated that this case was hepatocellular carcinoma of the clear cell type with a prominent myxoid stroma.     

Distribution of Antigens Detected with MB1, MB2 and MB3 on Non-hematopoietic Human Organs and Various Tumors

We have examined the distribution of antigens detected by MB1, MB2 and MB3 on non-hematopoietic normal human tissues and various types of benign and malignant tumors. MB1 and MB2 reacted with various organs, such as the epithelium of various glands, smooth muscle cells, vascular endothelial cells, and peripheral nerve tissue. The distributions of these two antibodies were essentially identical. Reactivity with MB3 was confined to the ductal eDithelium of salivary glands, the pancreas, and sweat glands, and the cortex of the adrenal gland. lmmunoblotting analysis demonstrated that MB1 and MB2 reacted with a few bands of an extract of myometrial cytoskeletal fraction and salivary gland cytosol fraction, whereas MB3 failed to show any bands on these materials. The reactivities of MB1 and MB2 with various neoplasms were similar to those in normal organs, with slight variations of staining pattern and preponderance in well differentiated tumors. Exceptionally, carcinoid tumor and small round cell tumors, such as small cell carcinoma or neuroblastoma, were not reactive with MB1 and MB2. MB3 reacted with several cases of well differentiated benign and malignant epithelial tumors in various organs, and exceptional cases of malignant schwannoma and glioma. These results indicate that the antigens detected by MB1 and MB2 are distributed broadly on non-hematopoietic normal organs, whereas those detected by MB3 are confined to exceptional cases of epithelial and non-epithelial tumors. Thus, although the use of MB1, MB2 and MB3 is of little value for differential diagnosis of various tumors, these three antibodies may be useful for determining of the origin of some tumor types. Acta Pathol Jpn 42: 339–346, 1992.     

Benign clear cell tumor of the lung in an 8-year-old girl

A case of "benign clear cell tumor of the lung" occurred in an 8-year-old girl. The tumor was a solid well-circumscribed mass, measuring 1 cm in diameter. Histologically, it consisted of polygonal cells intermingled with large, thin-walled vessels. Glycogen was scarce in paraffin sections; however, electron microscopic observation revealed a large amount of glycogen. Intracytoplasmic filaments were not observed, but scattered pinocytotic vesicles and plaquelike densities along the plasma membrane were found.     

The afferent and efferent pathways of the recto-colonic reflex in the dog

The nature of the afferent and efferent pathways of the recto-colonic reflex was studied electrophysiologically in the dog. A compound action potential consisting of many peaks was evoked on a sacral dorsal rootlet by a stimulus to the ipsilateral rectal strands of the pelvic nerve. Conduction velocities of the peaks indicate that A delta and C afferent fibers innervate the colon and rectum. When the stimuli were subthreshold for C fibers, the reflex discharges of contralateral parasympathetic post-ganglionic fibers in the rectal strands and the reflex contraction of the colon were smaller than those caused by stronger stimuli. As the intensity of the stimulus to the sacral ventral roots was weakened, response peaks of preganglionic B fibers in the rectal branch, post-ganglionic C fibers in the rectal strands and a bladder branch of the pelvic nerve disappeared in the order of slow to fast conduction velocities. Contraction of the colon also decreased. The number of peaks arising from each nerve correlated well with the strength of the contraction. These results indicate that the peripheral limbs of the recto-colonic reflex arc consist of afferent A delta and C fibers, preganglionic B fibers and post-ganglionic C fibers.     

NGF-dependent and -independent growth of neurites from sympathetic ganglion cells of the aged human in a serum-free culture

Small pieces of tissue isolated from abdominal sympathetic ganglia in aged male patients were cultured in a chemically defined, serum-free medium. The growth of neurites from pieces of ganglia in cultures with and without 50 ng/ml mouse 2.5S nerve growth factor (NGF) was compared. The NGF stimulated significantly greater regeneration of neurites, causing the growth of long fibers from the ganglion pieces. Many short neurites grew, even in the absence of the NGF, but these were generally short, except for long neurites generated in several nerve cells. A method was devised for the evaluation of NGF-dependent growth of neurites in the culture. The rate of the NGF-dependent growth of neurites, which was calculated by the difference in the total lengths of the NGF-dependent neurites between 2- and 4-day-old cultures, was approximately 160 micron/day. The results indicate that although the growth of neurites from some sympathetic nerve cells of the aged human become independent of the NGF, most of the nerve cells remain dependent on the NGF, even in the stage of senescence.