The proliferative potential of human ependymomas measured by in situ bromodeoxyuridine labeling

Twelve patients with ependymomas received a 30- to 60-minute intravenous infusion of bromodeoxyuridine (BrdU), 150 to 200 mg/m2 at surgery, to label tumor cells in the DNA synthesis phase. Labeled cells were detected in excised tumor specimens by indirect immunoperoxidase staining using anti-BrdU monoclonal antibody as the first antibody. The BrdU labeling index (LI, defined as the percentage of labeled cells in relation to the total number of cells scored) was calculated for each specimen. All four spinal cord ependymomas had a BrdU LI of less than 1%, which is consistent with our clinical experience that most such tumors grow slowly and have an excellent prognosis. Five of the eight intracranial ependymomas also had a low BrdU LI of approximately 1% or less, and three had a BrdU LI of 3.2%, 3.4%, and 4.8%. The latter three tumors, only one of which was diagnosed as a malignant ependymoma at the time of study, were either recurrent or recurred within 2 years after gross or subtotal removal. Cytologic analysis of cerebrospinal fluid (CSF) was performed in five cases; CSF seeding of tumor cells was found in only one patient, who had a malignant ependymoma. A high BrdU LI did not always correlate with CSF seeding. Measurement of the LI using BrdU and anti-BrdU monoclonal antibodies can provide more accurate information on the proliferative potential of individual tumors and may lead to a more rational grading system of ependymomas. The results of such studies do not always predict the potential for CSF seeding.     

Determinants of Drug Response in a Cisplatin-resistant Human Lung Cancer Cell Line

To elucidate the mechanism(s) of cisplatin resistance, we have characterized a human non-small cell lung cancer cell line (PC-9/CDDP) selected from the wild type (PC-9) for acquired resistance to cisplatin. PC-9/CDDP demonstrated 28-fold resistance to cisplatin, with cross resistance to other chemotherapeutic drugs including chlorambucil (× 6.3), melphalan (× 3.7) and 3-[(4-amino-2-methyl-5-pyrimidinyl)]methyl-1-(2-chloroethyl)-1-nitrosourea (ACNU) (× 3.9). There was no expression of mdr-1 mRNA in either wild-type or resistant cells. The mRNA and protein levels of glutathione S -transferase (GST) × were similar in the two lines. A GST-μ isozyme was present in equal amounts and the activities of selenium-dependent and independent glutathione peroxidase and glutathione reductase were unchanged. The mRNA level of human metallothionein IIA and the total intracellular metallothionein levels were reduced in the resistant cells. Significantly increased intracellular glutathione (GSH) levels were found in the resistant cells (20.0 vs. 63.5 nmol/mg protein) and manipulation of these levels with buthionine sulfoximine produced a partial sensitization to either cisplatin or chlorambucil. Increased GSH probably also played a role in determining cadmium chloride resistance of the PC-9/CDDP, even though this cell line had a reduced metallothionein level. Also contributing to the cisplatin resistance phenotype was a reduced intracellular level of platinum in the PC-9/CDDP. Thus, at least two distinct mechanisms have been selected in the resistant cells which confer the phenotype and allow degrees of cross resistance to other electrophilic drugs.     

Production of Basic Fibroblast Growth Factor-like Factor by Cultured Human Cholangiocellular Carcinoma Cells

An extract of cultured human cholangiocellular carcinoma cells (HuCC-T1) was found to contain high mitogenic activity for BALB/c3T3 cells. The growth factor eliciting most of the mitogenic activity was purified and concluded to be identical with basic fibroblast growth factor (bFGF)-like factor on the basis of its molecular weight and heparin-Sepharose elution profile, and the results of immunoblotting and radioimmunoassay. HuCC-T1 cells also secreted bFGF-like factor into serum-free medium. A combination of insulin and transferrin or bovine serum albumin stimulated the growth of HuCC-T1 cells in serum-free medium. However, bFGF did not stimulate their growth in the presence and absence of these supplements. Neutralizing monoclonal antibody against bFGF did not inhibit growth. These results indicate that bFGF-like factor is not a growth factor for this cell line.     

SCANNING ELECTRON MICROSCOPIC STUDIES OF DERMAL SKIN AND CONNECTIVE TISSUE DISORDERS

By using scanning electron microscopy (SEM), three dimensional structures of the matrixes and fibrous components in human dermal skin, scleromyxedema, systemic lupus erythematodes (SLE), progresive systemic sclerosis (PSS) and amyloidosis cutis were observed. SEM pictures were compared with those from conventional transmission electron microscopy and histochemistry. In human dermal skin and scleromyxedema, the matrixes were not fixed in glutaraldehyde and osmic acid. FAC fixation was employed in these specimens. After fixing specimens, streptomyces hyaluronidase digestion was made and examined by the SEM. In human dermis and scleromyxedema, hyarulonic acid occurred between collagen and elastic fibers. In systemic lupus erythematodes and progresive systemic sclerosis, specimens were fixed in glutaraldehyde and osmic acid, and examined in the same way. In SLE, collagen fibers were dissociated and the normal wavy pattern was lost. In PSS, abnormally increased branching fibers were observed. In amyloidosis cutis, amyloid fibrils were not observed by conventional SEM. Specimens were dehydrated in a critical point dryer and examined by the field emission scanning microscope. Amyloid fibrils were interwoven in a felt-like fashion.     

Different inducibility of metallothionein in various mammalian cells in vitro

Human lymphocytes and mouse embryonic cells (A-31) have lower or slower inducibility of metallothionein (MT) synthesis on exposure to 2.5 μg of cadmium (Cd)/ml for 24 h than human liver cells, HeLa cells, rabbit kidney cells and mouse FRD cells. Differential inducibility has been observed among some mammalian cells in vitro.     

Meningiomas of the temporal bone

Meningiomas should be considered in the differential diagnosis of otologic tumors arising from the middle ear and mastoid. It is generally recognized that meningiomas may invade the temporal bone via direct extension from the intracranial space (secondary). It is not generally recognized that meningiomas can develop initially in the middle ear cleft (primary). Representative cases of primary and secondary meningiomas of the temporal bone are described, and clinical aspects of diagnosis and surgical management are discussed. In order to assess the pathogenesis of meningiomas of the temporal bone, histological studies were done on 200 temporal bone specimens. In certain specimens, ectopic arachnoid granulations, from which primary meningiomas may originate, were identified and described, according to location. One specimen was most unusual in that it contained ectopic glial as well as arachnoidal tissue.     

Central control of posture: reciprocal discharge by two pontine neuronal groups leading to suppression of decerebrate rigidity

Spinal subarachnoid perfusions of rhesus monkeys were performed to study the transport of 3-methoxy-4-hydroxyphenylethyleneglycol (MHPG) by the spinal cord. The perfusate contained [³H]MHPG and a reference extracellular space marker ([¹⁴C]sucrose or [¹⁴C]ethylenediaminetetraacetic acid-calcium complex). The mean (±S.D.) clearance of MHPG by the monkey spinal cord was 33 (± 4) μl/min. Analysis of serial sections of spinal tissue after each perfusion facilitated determination of several basic parameters of MHPG transport. MHPG has a spinal tissue distribution space of 70–80%. MHPG enters capillaries withing spinal tissus throughout the entire spinal cord. The mean capillary exchange half-time was 8.2 min ± 1.9 min. MHPG crosses cell membranes easily and diffuses through cells rapidly. The apparent tissue diffusion coefficient approximated the diffusion coefficient in water (8.5 × 10^?6 sq.cm/sec). The data suggests that CSF levels of MHPG are an uncertain indicator of norepinephrine metabolism and that lumbar CSF levels of MHPG reflect in large part spinal cord rather than brain metabolism.     

Ultrasonic studies on endocardial fibroelastosis

Four patients with endocardial fibroelastosis were studied by two-dimensional and M-mode echocardiography. The two-dimensional echocardiography showed the characteristic echo from the abnormally thickened endocardium of the left ventricle in every case. Of the 4 cases, 2 were still suffering from congestive heart failure at the time of the study and the other 2 had been already free from clinical symptoms. In the former group, the ultrasonic findings revealed an enlargement of the left ventricle (large left ventricular dimension index) and poor movement of the anterior mitral leaflet which was indicated by a decrease in the diastolic descent rate. The latter group presented almost normal findings concerning the above points. The ultrasonic method is thus proved to be very useful for the diagnosis and evaluation of clinical conditions in cases of endocardial fibroelastosis.