Penetrating injury of the transverse sinus by a nail-gun--case report

A 46-year-old male presented with a penetrating injury of the transverse sinus caused by a nail-gun. Open craniotomy reflected a doughnut-shaped bone flap and the 45 mm long nail, which was fortunately only touching the edge of the sinus, successfully removed. A wide surgical exposure and careful manipulation of the embedded nail are important to avoid inadvertent injury to the venous sinus and the surrounding brain tissues during the surgical procedure.

Comparative SPECT study of stroke using Tc-99m ECD, I-123 IMP, and Tc-99m HMPAO

Brain perfusion SPECT imaging using Tc-99m ethyl cysteinate dimer (ECD) was carried out in 12 patients with chronic cerebrovascular disease. The sensitivity of lesion detection and lesion-to-normal tissue contrast was compared with those of I-123 IMP and Tc-99m HMPAO. Eight patients underwent all three studies and the remaining four patients had Tc-99m ECD and I-123 IMP scans. The sensitivity of lesion detection and lesion contrast was analyzed quantitatively using an asymmetric index determined by the equation: 100 x [right - left[/(right + left). In the cerebral cortex, cerebellum, and white matter, I-123 IMP showed higher lesion sensitivity than Tc-99m ECD and Tc-99m HMPAO. In the striatum and thalamus, Tc-99m ECD and I-123 IMP showed higher lesion sensitivity than Tc-99m HMPAO. I-123 IMP showed the highest lesion contrast in cerebral cortex and cerebellum, whereas Tc-99m ECD showed the highest contrast in thalamus and striatum. In all regions, Tc-99m ECD showed higher lesion contrast than Tc-99m HMPAO. These results suggest regional variation in the sensitivity of lesion detection and lesion contrast of Tc-99m ECD compared to I-123 IMP, and the superiority of Tc-99m ECD to Tc-99m HMPAO.

Differential biological significance of tissue-type and urokinase-type plasminogen activator in human breast cancer

Plasminogen activator (PA) is a serine protease existing in two forms known as tissue-type (t-PA) and urokinase-type (u-PA). To examine whether PA is related to the postoperative clinical course of human breast cancer, total PA activity, t-PA activity, u-PA activity, and immunoreactive t-PA were determined in tissue extracts from 144 breast cancer specimens. The patients were initially divided into four groups according to the postoperative clinical course: Group I (83 patients who are disease-free), Group II (20 patients whose first metastases were found only in bone), Group III (19 patients whose first metastases were found in both bone and lung), and Group IV (22 patients whose first metastases were found only in lung). Total PA activity was significantly lower in Groups, II, III and IV than in Group I. Both t-PA activity and t-PA antigen levels were also significantly lower in Groups II, III and IV than in Group I, while no significant difference was found in u-PA activity among these groups, indicating that low activity of total PA in Groups II, III and IV was due to a decrease in t-PA but not in u-PA. In the multivariate analyses, t-PA activity was found to be an independent prognostic factor for relapse-free survival. When four groups of patients were further analysed in terms of nodal status, both t-PA activity and antigen levels were markedly decreased in the node-negative Group II compared with the node-negative Groups III and IV or with the node-positive Groups II, III and IV. Of additional interest, u-PA activity was significantly higher in node-positive patients than in node-negative patients with any group. The clinico-pathologic analyses of the patients in this series showed that node involvement and lymphatic invasion were more frequently positive in Groups III and IV than in Groups I and II. When 144 breast cancers were categorised in terms of combinations of oestrogen receptor (ER) and progesterone receptor (PgR) status, breast cancers which were positive for both receptors were found to contain the highest t-PA activity and antigen. This study provides provocative evidence suggesting a possible differential significance of t-PA and u-PA expression in human breast cancer.

Prognosis of intracranial germ cell tumours: effectiveness of chemotherapy with cisplatin and etoposide (CDDP and VP-16)

A co-operative study for patients with intracranial germ cell tumours was performed to analyze their prognosis and the effectiveness of Cisplatin/Etoposide (CDDP/VP-16) chemotherapy. A total of 46 patients; 30 primary and 16 recurrent cases were registered from 15 participating neurosurgical institutions in Japan. Based on histological criteria and tumour markers, they were classified into three groups; germinoma, germinoma with syncytiotrophoblastic giant cell (STGC), and non-germinomatous malignant tumour. Sixteen patients were treated with CDDP/VP-16 chemotherapy alone and the other 30 patients were treated by a combination of surgery and/or radiation in addition to chemotherapy. Eleven out of 13 patients (85%) with germinoma showed a complete (n = 10) or partial (n = 1) response to CDDP/VP-16 chemotherapy even if their tumours were recurrent and there was evidence of CSF dissemination. For the germinoma with STGC and non-germinomatous malignant tumour, a high response rate; 100% for the former and 78% for the latter, could also be achieved in both the primary and the recurrent cases except in those cases of immature teratoma. Their survival times were still different between them. Two-year survival was 50% in germinoma with STGC and 48% in non-germinoma, while it was 88% in germinoma cases.

Signal intensity of brain metastases on T2-weighted images: specificity for metastases from colonic cancers

In this report, we present and discuss the signal intensity of brain metastases from colon cancer on both T1- and T2-weighted images. In five of 6 cases, metastases were seen as markedly hypointense areas on T2-weighted images. This finding should alert one to the possibility of a primary cancer of the colon. Some haemorrhagic metastases from other malignancies also showed marked hypointensity. They usually exhibited hyperintensity on T1-weighted images. A case of colon metastasis was also haemorrhagic, and in this case a hyperintense area was observed on T1-weighted images. The marked hypointense area corresponded to peripheral necrosis and probably some viable tumour. Aetiologically, such hypointensity was not induced by severe fibrosis, calcification or excessive iron deposition.

Spinal cord infarction associated with primary antiphospholipid syndrome in a young child. Case report

Antiphospholipid antibodies have been reported to occur in ischemic stroke patients, but there have been no previous reports linking these antibodies to spinal cord infarction. A case of spinal cord infarction associated with primary antiphospholipid syndrome in a 6-year-old boy is reported. Magnetic resonance imaging clearly demonstrated marked swelling of the thoracolumbar spinal cord with gadolinium-diethylenetriamine pentaacetic acid enhancement at an acute stage, followed later by cord atrophy. Serological study disclosed positive lupus anticoagulant and immunoglobulin G anticardiolipin antibody. It is suggested that the role of antiphospholipid antibodies as an etiological factor for spinal cord ischemia should be recognized among causes that might have been categorized as either spontaneous spinal cord infarction or myelitis.

Supratentorial low-grade astrocytoma. Correlation of computed tomography findings with effect of radiation therapy and prognostic variables

BACKGROUND

In supratentorial low-grade astrocytoma, radiation therapy effects and prognostic factors, especially with respect to computed tomography (CT) findings, are not yet well established. A retrospective analysis of 119 patients with this disease (histologically confirmed ordinary astrocytoma) therefore was conducted.

METHODS

Between 1965 and 1989, 101 patients received postoperative radiation therapy, whereas 18 patients received surgery alone. Radiation was directed to the tumor plus a 1- to 3-cm margin in almost all cases; the dose range was 41 to 66 Gy (mean, 57 Gy). CT scan was performed before treatment on 74 patients. Postoperative survival rates were compared by both univariate and multivariate analyses.

RESULTS

The 5- and 10-year survival rates for the irradiated group were 60% and 41%, respectively, which were significantly better than those for the surgery-alone group (37% and 11%, P = 0.048). Among various potential prognostic factors for the irradiated patients, only a lower age was associated with a better prognosis. Sex, tumor site (deep-seated or not), extent of surgery, radiation dose and field, and adjuvant chemotherapy did not influence the prognosis significantly. Among various CT findings, a clear tumor margin, a maximum tumor area less than 25 cm2, presence of a cyst, and lack of mass effect were associated with a better prognosis on univariate analysis (P = 0.02-0.12), but contrast enhancement was not related to prognosis. On multivariate analysis, however, mass effect was the only significant factor.

CONCLUSIONS

Radiation therapy appears definitely to be effective in improving the prognosis for low-grade astrocytoma. Younger age, and the absence of mass effect determined by CT, were associated significantly with a better prognosis.

Uptake of drugs and expression of P-glycoprotein in the rat 9L glioma

Two weeks after the inoculation of 1.5 x 10(5) 9L glioma cells into the rat brain, the uptake of radiolabelled drugs into the brain and the experimental 9L glioma during the first cerebral circulation was measured with a liquid scintillation counter and analyzed by the method of Oldendorf (1970). The expression of P-glycoprotein, which is known to be associated with the efflux of drugs, was also studied, using anti-P-glycoprotein monoclonal antibody, C-219. Furthermore, the ultrastructure of brain capillaries, tumor vessels, and glioma cells was studied by conventional and immunoelectron microscopy. Sucrose (control), the transport of which through the blood-brain barrier is known to be negligible, accumulated to fivefold higher levels in the tumor than in normal brain. Ranimustine (MCNU), 5-fluorouracil (5-FU), and doxorubicin showed little accumulation in the normal brain, whereas nimustine (ACNU) showed an increased accumulation. MCNU and doxorubicin showed negligible accumulation in the glioma cells despite diffusion into the tumor interstitial space. In contrast, ACNU and 5-FU showed an increased accumulation in tumor cells. The accumulation of 5-FU in the cultured 9L glioma cells was decreased by ATP inhibitors or by low temperature. Although both brain capillary endothelial cells and glioma cell membrane were immunohistochemically positive for P-glycoprotein, the tumor vasculature showed low expression of P-glycoprotein. The endothelial cells of tumor vessels ultrastructurally showed increased fenestrations, swelling, and disrupted junctions. Accordingly, it is suggested that hydrophobic drugs such as doxorubicin, being pumped out by P-glycoprotein, do not accumulate in 9L glioma cells as do other lipophilic drugs such as ACNU, or drugs such as 5-FU, which accumulate by a carrier-mediated mechanism.

Supratentorial low-grade astrocytoma. Correlation of computed tomography findings with effect of radiation therapy and prognostic variables

BACKGROUND

In supratentorial low-grade astrocytoma, radiation therapy effects and prognostic factors, especially with respect to computed tomography (CT) findings, are not yet well established. A retrospective analysis of 119 patients with this disease (histologically confirmed ordinary astrocytoma) therefore was conducted.

METHODS

Between 1965 and 1989, 101 patients received postoperative radiation therapy, whereas 18 patients received surgery alone. Radiation was directed to the tumor plus a 1- to 3-cm margin in almost all cases; the dose range was 41 to 66 Gy (mean, 57 Gy). CT scan was performed before treatment on 74 patients. Postoperative survival rates were compared by both univariate and multivariate analyses.

RESULTS

The 5- and 10-year survival rates for the irradiated group were 60% and 41%, respectively, which were significantly better than those for the surgery-alone group (37% and 11%, P = 0.048). Among various potential prognostic factors for the irradiated patients, only a lower age was associated with a better prognosis. Sex, tumor site (deep-seated or not), extent of surgery, radiation dose and field, and adjuvant chemotherapy did not influence the prognosis significantly. Among various CT findings, a clear tumor margin, a maximum tumor area less than 25 cm2, presence of a cyst, and lack of mass effect were associated with a better prognosis on univariate analysis (P = 0.02-0.12), but contrast enhancement was not related to prognosis. On multivariate analysis, however, mass effect was the only significant factor.

CONCLUSIONS

Radiation therapy appears definitely to be effective in improving the prognosis for low-grade astrocytoma. Younger age, and the absence of mass effect determined by CT, were associated significantly with a better prognosis.

Antitumor agents. 3. Synthesis and biological activity of 4 beta-alkyl derivatives containing hydroxy, amino, and amido groups of 4'-O-demethyl-4-desoxypodophyllotoxin as antitumor agents

A series of 4 beta-alkyl (7-10), 4 beta-aminoalkyl (12a-y), and 4 beta-amidoalkyl derivatives (14a-g) of 4'-O-demethyl-4-desoxypodophyllotoxin have been synthesized, and their cytotoxicity, inhibition of DNA topoisomerase II (Topo II), and tubulin polymerization were evaluated. All derivatives of 12a-y and 14a-g did not inhibit tubulin polymerization. Many compounds exhibited cytotoxicity and inhibition of Topo II. In particular, 12o, 12s, 12t, and 12u strongly inhibited Topo II (IC50 (microM) 32.5, 60.9, 58.8, and 33.6, respectively) and were strong cytotoxicity against P388 cells (IC50 (M) 1.0, 4.1, 3.3, and 3.0 x 10(-9), respectively), compared with VP-16 (IC50 (microM) 59.2, IC50 (M) 1 x 10(-8), respectively). These compounds were nearly equal to or superior to VP-16 in antitumor activity in vivo (L1210, P388, and Lewis lung) and were more cytotoxic against various human cell lines in vitro than VP-16.

Increased expression of membrane-associated phospholipase A2 shows malignant potential of human breast cancer cells

BACKGROUND

Recently, the authors reported that membrane-associated phospholipase A2 (M-PLA2) was one of the acute phase reactants and increased in serum of patients with various malignant tumors.

METHODS

M-PLA2 concentrations in tissue specimens from 78 breast cancers, 16 benign breast tumors, and 10 normal breast tissues were determined by a specific radioimmunoassay recently developed. Immunohistochemical staining was performed on all specimens by the avidin-biotin-peroxidase method.

RESULTS

Tissue levels of M-PLA2 concentration were significantly higher in breast cancer than in benign breast tumor or normal breast tissue (P < 0.01). Correlation analyses between the tissue concentration of M-PLA2 and clinicopathologic factors showed that tissue M-PLA2 levels were significantly higher in patients with skin or muscle invasion, vessel involvement, and distant metastasis than in those without. In addition, this enzyme concentration was significantly greater in scirrhous carcinoma than in papillotubular or solid-tubular carcinoma. No association was found between M-PLA2 concentration and steroid hormone receptor status. Immunohistochemically, M-PLA2 was preferentially stained in the invading zone of breast cancer tissues, especially in scirrhous carcinoma. Patients with breast cancer with low levels of M-PLA2 showed significantly longer overall survival and disease-free survival compared with those with high levels of this enzyme at the cutoff point of 50 ng/100 mg protein. The combination of estrogen receptor status with M-PLA2 concentration could be a powerful prognostic factor in predicting such survival rates.

CONCLUSIONS

M-PLA2 is closely related to the malignant potential of breast cancers, and the M-PLA2 contents in breast cancer tissues could be a new valuable prognostic factor, other than the hormone receptor, in delineating the status of human breast cancer.

A protein homologous to human Ku p70-protein is required for reconstitution of Xenopus sperm pronuclei

The monoclonal antibody mAbH6, which recognizes one human Ku-protein (p70), cross-reacted with the counterpart protein from Xenopus eggs. The Xenopus antigen purified with a mAbH6-Sepharose column was a complex of 88 kDa and 72 kDa proteins. The role of Ku protein in nuclear structure formation was studied using a cell-free nuclear assembly extract derived from Xenopus interphase eggs. The protein was distributed on the surface of demembranated sperm chromatin and in the membrane vesicle fraction of the nuclear assembly extract. Addition of mAbH6 to the assembly extracts prevented the completion of reconstitution of pronuclei from demembranated sperm chromatins, although partial decondensation mediated by nucleoplasmin was not impeded. As a result, the sperm chromatin remained in partially swollen structures or formed round but small anomalous nuclei. Nuclear membranes were formed on the nuclei in mAbH6-inhibited extract systems, but DNA synthesis was largely decreased, suggesting the incomplete reconstitution of pronuclei. The incorporation of lamin to the nuclei was inhibited by mAbH6. It is suggested that the Xenopus Ku-homologous protein has a role in the formation of the lamin layer after nuclear membrane reconstitution.

Antitumor agents. II: Regio- and stereospecific syntheses of 1-beta-alkyl-1-desoxypodophyllotoxin derivatives and biological activity

1-beta-Alkyl derivatives of 1-desoxypodophyllotoxin were synthesized, and their cytotoxicity and inhibitory effects on DNA topoisomerase II (Topo-II) and tubulin polymerization were examined. The reaction of epipodophyllotoxin derivatives (1a-c) with trimethylallylsilane in the presence of boron trifluoride etherate gave 1-beta-allylated compounds (2a-c). The regiochemistry and the beta-stereochemistry of the 1-allyl group were confirmed by comparison of the 13C-NMR spectra and NOE's (%) of 2c, podophyllotoxin (POD) and epipodophyllotoxin (1b). 1-beta-Alkyl-1-desoxypodophyllotoxin derivatives (3-8) were prepared from 2b. None of the tested compounds (3-8) showed any inhibitory effect on Topo-II. 1-beta-Propyl compound (3) and its 4'-demethyl compound (4) inhibited tubulin polymerization and the cytotoxicities of these compounds were equal to that of VP-16. 1-beta-(2,3-Dihydroxypropyl) compounds (5 and 8) and 1-beta-(2,3-diacetoxypropyl) compounds (6 and 7) showed no inhibitory effect on tubulin polymerization. Although 5 did not inhibit either Topo-II activity or tubulin polymerization, it showed a high cytotoxicity against sarcoma 180.

An open reading frame in the Rhodospirillum rubrum plasmid, pKY1, similar to algA, encoding the bifunctional enzyme phosphomannose isomerase-guanosine diphospho-D-mannose pyrophosphorylase (PMI-GMP)

The nucleotide sequence of a BglII fragment (3188 bp) from the plasmid pKY1 of Rhodospirillum rubrum was determined. A significant similarity was found between the amino acid sequences deduced from the nucleotide sequence of BglII fragment with that of algA, encoding the bifunctional enzyme with both the activities of phosphomannose isomerase and guanosine diphospho-D-mannose pyrophosphorylase of Pseudomonas aeruginosa.

Interleukin 6 stimulates the production of immunoreactive endothelin 1 in human breast cancer cells

To investigate the potential regulation of endothelin 1 production in human breast cancer cells, we measured the release of immunoreactive endothelin 1 (ir-ET-1) from the MCF-7 and ZR-75-1 breast cancer cell lines in response to various agents including estrogen and tamoxifen as well as several cytokines. ir-ET-1 was detected in conditioned medium of MCF-7 cells and ZR-75-1 cells by specific radioimmunoassay. Among the agents tested, estrogen, tamoxifen, tumor necrosis factor, gamma-interferon, interleukin (IL) 1, and transforming growth factor beta had no effect on ir-ET-1 secretion by these breast cancer cells. However, IL-6 (20 ng/ml) treatment of MCF-7 cells and ZR-75-1 cells caused maximal increases in the amount of ir-ET-1 secreted into the culture medium to 206 and 314% of basal values after 6 h, respectively. This effect of IL-6 on ir-ET-1 secretion was inhibited by actinomycin D and cycloheximide, indicating that IL-6 stimulates de novo synthesis of ir-ET-1 at a transcriptional level. Reverse-phase high performance liquid chromatography coupled with radioimmunoassay in the conditioned medium from IL-6-treated cells revealed one major ir-ET-1 component corresponding to human standard ET-1. The present study demonstrates the potential for IL-6 to stimulate ir-ET-1 production in human breast cancer cells, which may participate in the process of acute phase reactant-like expression of this peptide and/or in the process of IL-6 enhanced breast cancer cell motility, the latter being recently clarified.

Breast cancer prognosis is poor when total plasminogen activator activity is low

Plasminogen activator (PA) is a serine protease which exists in two forms: tissue-type (t-PA) and urokinase-type (u-PA). The total PA activity was measured in tumour extracts of 235 breast cancer patients who were followed for a median of 8.5 years after surgery. Patients were initially divided into three groups with low (< 60 units mg-1 protein), intermediate (60-300 unit mg-1 protein), or high (> 300 unit mg-1 protein) total PA activity in tumour extracts. The PA activity was not significantly associated with the recognised prognostic factors of age, menstrual status, tumour size, lymph node involvement, histologic type, grade of anaplasia, and/or vessel involvement. A significant association was found between total PA activity and the oestrogen receptor (ER) or progesterone receptor (PgR) status. Among receptor-positive tumours, a significantly greater proportion of patients had high PA activity in their tumour extracts. Breast cancer patients with low total PA activity had a significantly shorter disease-free and overall survival rate when compared to those with intermediate or high PA activity. In univariate and multivariate analyses, total PA activity (< 60 unit mg-1 vs > or = 60 unit mg-1 protein) was found to be a significant prognostic factor for disease-free and overall survival of about the same import as lymph node involvement. Furthermore, the combination of total PA activity and nodal status could be even more precise in predicting survival times and probabilities in individual patients. This retrospective study demonstrates the total PA activity is a valuable prognostic factor in determining prognosis in human breast cancer.

Effects of high-dose chemotherapy with syngeneic bone marrow transplantation in experimental brain tumor in rats

BACKGROUND

The clinical dose of 3-[(4-amino-2-methyl-5-pyrimidinyl)methyl]-1-(2-chloroethyl)-1-nitro- sourea hydrochloride (ACNU) is limited by the bone marrow suppression it produces. The authors investigated whether bone marrow transplantation (BMT) associated with a high dose of ACNU could alleviate marrow toxicity and achieve greater antitumor effects in Fischer rats.

METHODS AND RESULTS

High doses of ACNU (20, 25, and 30 mg/kg) were administered on day 1, followed by injection of syngeneic bone marrow cells on day 3. Patterns of leukocyte recovery were compared in BMT and non-BMT groups. There was a significant benefit in leukocyte recovery in the BMT groups. A 9L glioma that was sensitive to ACNU was transplanted into the brain tissue of rats. Seven days later, the animals were divided into three groups based on the dose of ACNU (2, 10, and 25 mg/kg). The median survival time increased with larger ACNU doses.

CONCLUSIONS

This suggested that high-dose ACNU chemotherapy with BMT could achieve greater antitumor effects and less bone marrow suppression than high-dose ACNU alone.

Poorly differentiated orbital rhabdomyosarcoma with intracranial extension: a case report

The authors report a case of poorly differentiated orbital rhabdomyosarcoma with intracranial extension in a 5-month-old female. The clinical and pathologic characteristics are discussed with reference to the differential diagnosis.

High resolution Tc-99m HMPAO SPECT in a patient with transient global amnesia

This is a report of a patient who underwent high-resolution brain perfusion SPECT studies during and after an episode of transient global amnesia. During the attack, SPECT imaging showed increased perfusion in the left medial temporal region involving the amygdala and hippocampus. After recovery from amnesia, a follow-up SPECT examination showed slightly decreased perfusion in this region. These findings support the hypothesis that transient global amnesia is associated with transient hyperperfusion in the medial temporal brain structures, and confirm the utility of high-resolution SPECT imaging for the evaluation of the fine details of functional brain anatomy.

Gliosarcoma of the posterior cranial fossa: MRI findings

We report the MR findings of a biopsy-proven gliosarcoma of the posterior cranial fossa. Multiple homogeneously enhancing lesions had shaggy margins and broad-based dural attachments, which may reflect the gliomatous and sarcomatous element of this tumour.

Specific stimulation by estradiol of tissue-type plasminogen activator production in 7,12-dimethylbenz[a]anthracene-induced rat mammary tumor cells

The hormonal regulation of two plasminogen activators, tissue-type plasminogen activator (t-PA) and urokinase (u-PA), was studied both in 7,12-dimethylbenz[a]anthracene (DMBA)-induced rat mammary carcinoma and in DMBA-induced rat mammary dysplasia. t-PA activity in DMBA-mammary carcinoma was decreased markedly by oophorectomy and recovered upon estradiol administration to reach the maximum level at 12 hr. In contrast to its effect on DMBA-mammary carcinoma, estradiol had no effect on t-PA activity in DMBA-mammary dysplasia. Furthermore, DMBA-mammary carcinoma cells in primary culture displayed similar estrogen-dependency in production of t-PA, while t-PA production in DMBA-mammary dysplasia cells was not under the control of estradiol in vitro. Moreover, estrogen-stimulated production of u-PA activity was not observed in DMBA-mammary carcinoma cells or DMBA-mammary dysplasia cells both in vivo and in vitro. Taken together, these results suggest that estrogen stimulates the production of t-PA but not u-PA and that this estrogen dependency of t-PA is limited to malignant DMBA-mammary tumor cells.

Postoperative central conduction time and cerebral blood flow in patients with aneurysmal subarachnoid hemorrhage: relationship with prognosis and ischemic conditions

Cerebral blood flow (CBF) and somatosensory evoked potential (SEP) were monitored periodically on 32 patients who underwent aneurysm clipping within 3 days after subarachnoid hemorrhage (SAH). From the SEP data, central conduction time (CCT) was obtained, and CCT fluctuations were categorized into three types. Patients with CCT prolongation over 7.5 ms within 10 days after SAH tended to have poor recovery of CBF and unfavorable outcome. Therefore, periodical monitoring of CCT was considered as a useful indicator for predicting prognosis and post-SAH changes of cerebral blood flow.

Plasminogen activators in breast-cancer cells

This review summarizes recent experimental and clinical studies on plasminogen activator (PA) expression in breast cancer cells. The two PAs, urokinase-type (u-PA) and tissue-type (t-PA), have quite different biological significance in breast cancer cells. Sufficient evidence indicates that t-PA production is regulated by estrogen via an estrogen receptor system and suggests the potential usefulness of this enzyme as a marker for estrogen action in breast cancer cells. On the other hand, u-PA has been implicated in cancer cell invasion and metastasis formation because this enzyme can degrade components of the extracellular matrices and basement membranes either directly through its enzyme activity or indirectly by activation of other proteinases. High levels of u-PA correlates with both shortened disease-free survival and overall survival in patients with breast cancer indicating that u-PA is a new prognostic marker in human breast cancer. In contrast to u-PA, t-PA is associated with a good prognosis. However, t-PA is involved in bone-only metastasis formation by its effects through the vertebral venous plexus.

Expression of cell adhesion molecule E-cadherin in human arachnoid villi

Calcium-dependent epithelial cell adhesion molecules designated as E-cadherin (also known as uvomorulin or L-CAM) were identified in human arachnoid villi by immunoblotting and immunocytochemical analyses using a monoclonal antibody HECD-1 raised against human mammary carcinoma MCF-7 cells. Immunoblot analysis showed that HECD-1 recognizes E-cadherin with a molecular weight of 124 kD. In all arachnoid cells of an arachnoid villus, E-cadherin was detected by immunolight microscopy within the cytoplasm rather than the cellular boundaries as seen in the control group. Furthermore, the extent of expression by immunolight microscopy varied from portion to portion. The expression was usually weak in the syncytial cluster which was ultrastructurally composed of tightly juxtaposed cells characterized by few extracellular cisterns and numerous cell junctions, while it was intense in the reticular cluster and the surface layer which were ultrastructurally characterized by abundant extracellular cisterns and smaller numbers of cell junctions. The cells of the reticular cluster and the surface layer contained more free ribosomes than those of the syncytial cluster. Immunoelectron microscopy showed that E-cadherin was localized not only to the opposing plasma membranes and the cytoplasm around the free ribosomes or the rough endoplasmic reticulum but also to the extracellular cisterns. As the expression of E-cadherin was closely related to the arachnoid cells adjacent to the cerebrospinal fluid pathway, it is suggested that, instead of the cell junctions, E-cadherin may play an important role in the flexible adhesion of arachnoid cells even in the presence of the cerebrospinal fluid.