Modification of the Na,K-pump of glial cells within cobalt-induced epileptogenic cortex of rat

The characteristics of a glial Na⁺,K⁺-pump dependent on extracellular K⁺ within epileptogenic cortex were studied electrophysiologically, biochemically and histochemically in vitro using slices from cobalt-induced epileptogenic cortex of rat. When the extracellular K⁺ concentration ([K⁺]_o) was varied between 4 and 40 mM, the mean slope of membrane potential plotted against [K⁺]_o was about 57 mV in glia from the normal cortex (tissue A) and about 44 mV in glia from the epileptogenic cortex (tissue B); whereas no significant difference in the resting membrane potential of these tissues was observed. In glia from tissue B, a marked transient hyperpolarization above control level was caused by replacement of elevated [K⁺]_o with the normal medium. Ouabain abolished these phenomena observed in glia from tissue B, but had no effect on the membrane potential during normal [K⁺]_o. Reduction of extracellular Na⁺, Ca²⁺ and Cl⁻ did not significantly affect the membrane potential of glia from either tissue. In tissue A, the cells marked by intracellular injection of horseradish peroxidase after intracellular recording were protoplasmic astrocytes; in tissue B, fibrous astrocytes with abnormal processes predominated. K⁺-dependent stimulation of Na⁺,K⁺-ATPase activity of the astrocyte-enriched fraction and its membrane preparation from tissue B was much larger than that from tissue A. A certain amount of the reaction product of K⁺-pNPPase activity was seen on glial plasma membrane within tissue B but not on that from tissue A. The above findings suggest that a glial Na⁺,K⁺-pump within actively firing epileptogenic cortex may be modified to increase in its activity.     

Correlation of 99mTc-MDP scintimetry and histology in cervical hip fracture

In 20 cases of fresh cervical hip fracture, treated with primary prosthetic replacement, preoperative 99mTc-MDP scintimetry was compared with histologic findings of the extracted femoral heads. The radionuclide uptake was classified into three types according to the activity distribution; overall increase, focal decrease, and overall decrease. Histologically, the location and extent of ischemic necrosis in the femoral heads were closely related to the distribution of decreased activity.     

Electrochemotherapy significantly inhibits the growth of colon 26 tumors in mice

Electrochemotherapy is a novel antitumor treatment involving the systemic administration of bleomycin followed by the delivery of electrical pulses to the tumor. The present study investigates the effects of electrochemotherapy on the growth of colon 26 cells inoculated subcutaneously into the backs of BALB/c mice. The mice were divided into the following four experimental groups: 20 that received no further treatment after the inoculation of colon 26 cells (control group); 20 that received 500 μg of bleomycin intraperitoneally 7 and 9 days after the inoculation (BLM group); 20 that received electric pulses to the tumor 7 and 9 days after the inoculation (EP group); and 30 that received electrochemotherapy 7 and 9 days after the inoculation (ECT group). During 28 days of observation, no deaths due to tumor progression occurred in the ECT group, but there were 18 in the control group, 11 in the BLM group, and 18 in the EP group. While weight loss was observed in all groups, it was most remarkable in the control group. Tumor growth was significantly inhibited in the ECT group, compared to the other experimental groups (P<0.01). The results of this study demonstrated that electrochemotherapy significantly inhibited the growth of colon 26 tumors in mice, without causing any remarkable adverse effects.     

Monoclonality of both pale cells and cuboidal cells of sclerosing hemangioma of the lung.

Sclerosing hemangioma of the lung remains poorly understood, and it is still unclear whether this lesion is neoplastic or not. It consists of two major cell types, pale cells and cuboidal cells. We analyzed the clonality of each cell types from six female cases of surgically resected sclerosing hemangioma. The pale cells and cuboidal cells were separated by microdissection from methanol-fixed sections, and DNA was extracted for clonal analysis based on an X-chromosome-linked polymorphic marker, the human androgen receptor (HUMARA) gene or the phosphoglycerate kinase (PGK) gene. The HUMARA and PGK genes were found to be amplified with or without digestion by the methylation-sensitive restrictive endonuclease HpaII. Five of six cases were informative. Pale cells and cuboidal cells showed the same monoclonality in all of the informative cases, whereas the control cells showed a polyclonal pattern. Our results demonstrated that sclerosing hemangioma is caused by monoclonal expansion of cells, confirming that it is a neoplasia. Moreover, the present data indicate that both pale cells and cuboidal cells are derived from the same cell.     

A case report of invasive thymoma presenting as a solitary metastatic lesion of the lung]

A 66-year-old woman visited our hospital for further investigation of a coin-shaped lesion in the right lower lung field. After admission, CT-scan revealed an anterior mediastinal tumor. Thymoma and lung metastasis from thymoma were suspected. At thoracotomy, an invasive thymoma involving the left phrenic nerve, the left upper lobe, and the pericardium was found, and the diagnosis of lung metastasis was made. Postoperative pathological findings showed a predominantly lymphocytic thymoma with round and oval-shaped epithelial cells, and the metastatic lung lesion revealed the same findings. Postoperative radiotherapy (4000 rads) and chemotherapy with a combination of CDDP, VDS, and CPA were administered. The metastasis of thymoma is not rare, but most often it is found after operation. In this case the diagnosis of metastatic thymoma was made pre-operatively from a solitary lung lesion.     

Cystic radiolucencies of carpal bones, distal radius and ulna as a marker for dialysis-associated amyloid osteoarthropathy.

Patients on long-term hemodialysis (HD) are known to develop amyloid osteoarthropathy, evidenced as cystic radiolucencies on X-rays of the affected joints. To study the relationship between cystic radiolucencies and amyloid osteoarthropathy in 394 patients, we classified the severity of the cystic radiolucencies seen in the wrist joint on a 4-point scale and evaluated the association between lesion severity (grade) and several parameters. Biopsy was performed in 8 patients with 11 bone cysts of the wrist joint who had been operated for carpal tunnel syndrome. HD for 10 years or longer, age 50 or older and the presence of carpal tunnel syndrome were associated with severe cyst rating. There was no association between lesion grade and serum level of PTH-C, aluminum or beta 2-microglobulin (B2M). Ten of the 11 biopsied bone cysts in 8 patients with carpal tunnel syndrome demonstrated amyloid deposits which reacted with B2M. We conclude that a cystic radiolucency observed in the wrist joint of a patient undergoing HD indicates the deposition of amyloid. The cyst grade provides a useful marker for the severity of amyloid osteoarthropathy in HD patients.