Dendritic spine geometry is critical for AMPA receptor expression in hippocampal CA1 pyramidal neurons

Dendritic spines serve as preferential sites of excitatory synaptic connections and are pleomorphic. To address the structure-function relationship of the dendritic spines, we used two-photon uncaging of glutamate to allow mapping of functional glutamate receptors at the level of the single synapse. Our analyses of the spines of CA1 pyramidal neurons reveal that AMPA (alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid)-type glutamate receptors are abundant (up to 150/spine) in mushroom spines but sparsely distributed in thin spines and filopodia. The latter may be serving as the structural substrates of the silent synapses that have been proposed to play roles in development and plasticity of synaptic transmission. Our data indicate that distribution of functional AMPA receptors is tightly correlated with spine geometry and that receptor activity is independently regulated at the level of single spines.

Management and survival of female breast cancer: results of a national survey by the American College of Surgeons

This is a resume of a Breast Cancer Survey carried out by the American College of Surgeons in 1978. Four hundred and ninety-eight hospitals in 47 states, Washington, D.C., and Puerto Rico participated, contributing a total of 24,136 female patients with histologically confirmed breast cancer. In these patients, five-year cure rates were 60.5% for clinically localized disease and 33.9% for regional disease. Five-year survival rates were 72.8% for localized disease and 49.1% for regional disease. From the 1960's into the early 1970's, there was a gradual shift away from radical mastectomy towards so-called modified radical mastectomy. In a group of patients treated by either radical or modified mastectomies, the axillary nodal status, size of the tumor, and location of the tumor were examined in relation to the prognosis. In the study of number of metastatic nodes in the axilla, there were reduced cure and survival rates in patients with one or more positive nodes as compared to those with negative axillary nodes. With the increase in the number of positive nodes, there was a continuing associated decline in survival and cure. The clinical size of the tumor also correlated well to the prognosis. With the increase in the size of the tumor, there was a gradual increase in the probability of axillary nodal involvement. However, in the group of patients with tumor size smaller than 1 cm, axillary metastasis occurred in 25%. When the axillary nodes were involved, the cure rate in those patients was not significantly better than the rates for those with larger primary tumors in this study. Tumors located in the medial half of the breast were associated with a slightly lower cure rate than those in the lateral half. Young women under 35 years of age had poorer survival and cure rates, although in women 35-44 years of age, the five-year results were comparable to the older group of patients. In blacks, breast cancer was diagnosed in a relatively more advanced stage than in whites. Survival and cure rates were generally lower for blacks, and such lower rates seem to be associated with the relatively advanced stage of the disease.

Premenopausal breast cancer risk and intake of vegetables, fruits, and related nutrients

BACKGROUND

Given the international variations in breast cancer incidence rates and the changes in breast cancer incidence among migrant populations, it has been hypothesized that diet is a factor influencing risk of this disease. Many studies indicate that a diet high in vegetables and fruits may protect against breast cancer.

PURPOSE

We conducted a case-control study of diet, including the intake of non-food supplements, and premenopausal breast cancer risk. We evaluated in detail usual intake of vegetables and fruits (each measured as the total reported grams consumed for all queried vegetables and fruit), vitamins C and E, folic acid, individual carotenoids, and dietary fiber with its components.

METHODS

Case patients (n=297) were identified through pathology records from hospitals in Erie and Niagara counties in western New York. They consisted of premenopausal women 40 years of age or oder who were diagnosed with breast cancer from November 1986 through April 1991. Control subjects (n=311), frequency-matched to case patients on the basis of age and county of residence, were randomly selected from New York State Department of Motor Vehicles records. In-person interviews included detailed reports of usual diet in the period 2 years before the interview. Unconditional logistic regression was used to estimate odds ratios (ORs) and 95% confidence intervals (CIs).

RESULTS

There was a reduction in risk associated with high intake of several nutrients. With the lowest quartile of intake as the referent, adjusted ORs for the highest quartile of intake for specific nutrients were as follows: vitamin C (OR=0.53; 95% CI=0.33-0.86), alpha-tocopheral (OR=0.55; 95% CI=0.34-0.88), folic acid (OR=0.50; 95% CI=0.31-0.82), alpha-carotene (OR=0.67; 95% CI=0.42-1.08) and beta-carotene (OR=0.46; 95% CI=0.28-0.74), lutein + zeaxanthin (OR=0.47; 95% CI=0.28.0-77), and dietary fiber from vegetables and fruits (OR=0.48; 95% CI=0.30-0.78). No association with risk was found for beta-cryptoxanthin, lycopene, or grain fiber. Fruits were weakly associated with a reduction in risk (fourth quartile OR=0.67; 95% CI=0.42-1.09). No association was found between breast cancer risk and intake of vitamins C and E and folic acid taken as supplements. A strong inverse association between total vegetable intake and risk was observed (fourth quartile OR=0.46; 95% CI=0.28-0.74). This inverse association was found to be independent of vitamin C,alpha-tocopherol, folic acid, dietary fiber, and alpha-carotene. Adjusting for beta-carotene or lutein + zeaxanthin somewhat attenuated the inverse association with vegetable intake.

CONCLUSIONS

In this population, intake of vegetables appears to decrease premenopausal breast cancer risk. This effect may be related, in part, to beta-carotene and lutein + zeaxanthin in vegetables. It appears, however, that, of the nutrients and food components examined, no single dietary factor explains the effect. Evaluated components found together in vegetables may have a synergistic effect on breast cancer risk; alternatively, other unmeasured factors in these foods may also influence risk.

Fusion pore dynamics and insulin granule exocytosis in the pancreatic islet

Insulin secretion from intact mouse pancreatic islets was investigated with two-photon excitation imaging. Insulin granule exocytosis occurred mainly toward the interstitial space, away from blood vessels. The fusion pore was unusually stable with a lifetime of 1.8 seconds. Opening of the 1.4-nanometer-diameter pore was preceded by unrestricted lateral diffusion of lipids along the inner wall of the pore, supporting the idea that this structure is composed of membrane lipids. When the pore dilated to 12 nanometers, the granules rapidly flattened and discharged their contents. Thus, our methodology reveals fusion pore dynamics in intact tissues at nanometer resolution.

Chemotherapy induces regression of brain metastases in breast carcinoma

This study improves treatment options and ultimately survival by using systemic chemotherapy in brain metastases from breast carcinoma, since most of these patients have disseminated disease and a dismal prognosis when treated by conventional brain irradiation alone. One hundred consecutive patients with symptomatic brain metastases documented by radionuclide and/or computerized tomography scan were treated with systemic chemotherapy. Fifty of 100 patients demonstrated an objective response of brain metastases which was similar for extracranial metastases. There were 10 complete responders (CR), 40 partial responders (PR), 9 stable, and 41 nonresponders. Median duration of remission was 10+ months for CR and 7 months for PR (range, 2-72 months). Primary chemotherapy of brain metastases yielded responses in 27 of 52 patients (52%) treated with Cytoxan (cyclophosphamide) (C), 5-fluorouracil (F) and prednisone (P); 19 of 35 (54%) receiving CFP-methotrexate (M) and vincristine (V); 3 of 7 (43%) treated with MVP, and 1 of 6 (17%) receiving Cytoxan plus Adriamycin (doxorubicin) (CA). Thirteen of 35 patients (37%) who subsequently had relapse of brain metastases were retreated successfully with secondary chemotherapy. The median survival for CR and PR was 39.5 months and 10.5 months, respectively, in contrast with nonresponder patients who had a median survival of 1.5 months. Thirty-one percent of all treated patients survived more than 12 months. These findings suggest that the chemotherapeutic agents used penetrate the blood-brain barrier inducing regression of brain metastases. This approach offers a significant benefit by simultaneously controlling extracranial disease, improving the response and prolonging survival.

Diet in the epidemiology of breast cancer

A variety of studies have shown that diets high in fat, particularly polyunsaturated, have enhanced the production of tumors in animals challenged with chemical carcinogens. Other studies have found an apparent contradiction of no difference in the incidence of breast cancer among women with varying levels of serum cholesterol as measured decades earlier. The present study concerns 2024 breast cancer cases and 1463 control patients without neoplasms or pathology of the reproductive and digestive organs, seen at Roswell Park Memorial Institute from 1958 to 1965. Based upon the assessments of their varying ingestion of fats from their own reports of diets, no difference in risk was found. Similarly, there was no difference in risk of breast cancer associated with ingesting diets containing various levels of either vitamin C or the cruciferous vegetables. Risk for breast cancer in women 55 years of age and older increased somewhat with decreases in ingestion of foods containing vitamin A.

Rational Engineering of XCaMPs, a Multicolor GECI Suite for In Vivo Imaging of Complex Brain Circuit Dynamics

To decipher dynamic brain information processing, current genetically encoded calcium indicators (GECIs) are limited in single action potential (AP) detection speed, combinatorial spectral compatibility, and two-photon imaging depth. To address this, here, we rationally engineered a next-generation quadricolor GECI suite, XCaMPs. Single AP detection was achieved within 3-10 ms of spike onset, enabling measurements of fast-spike trains in parvalbumin (PV)-positive interneurons in the barrel cortex in vivo and recording three distinct (two inhibitory and one excitatory) ensembles during pre-motion activity in freely moving mice. In vivo paired recording of pre- and postsynaptic firing revealed spatiotemporal constraints of dendritic inhibition in layer 1 in vivo, between axons of somatostatin (SST)-positive interneurons and apical tufts dendrites of excitatory pyramidal neurons. Finally, non-invasive, subcortical imaging using red XCaMP-R uncovered somatosensation-evoked persistent activity in hippocampal CA1 neurons. Thus, the XCaMPs offer a critical enhancement of solution space in studies of complex neuronal circuit dynamics. VIDEO ABSTRACT.

Nutritional epidemiology of postmenopausal breast cancer in western New York

The authors studied 439 postmenopausal breast cancer cases, identified in hospitals throughout western New York, with an interview schedule that considered frequency and amount ingested of 172 foods and provided data for an estimate of total calories ingested. These were compared with age-matched controls comprising a random sample of the same communities as the cases. The extensive interviews, requiring 2.0 hours on average to administer, also covered alcohol ingestion, Quetelet index, and a wide variety of reproductive factors. The authors found, as have most investigators over the past 25 years, that risk increased with increases in age at first pregnancy, decreased with increases in numbers of children and pregnancies, and increased in those with history of benign breast disease and in those with female relatives previously affected with breast cancer. Risk adjusted for potential confounders was highest among women with the lowest ingestion of carotene or a substance correlated with its ingestion. Risk was not associated with retinol ingestion. It increased with increases in Quetelet index. Fat intake, whether studied in terms of quantity or the proportion of total calories derived from fat, was not associated with risk of breast cancer. Our analyses of these factors were adjusted for age, education, and the reproductive history traits described above.

Solitary pulmonary nodule: preliminary study of evaluation with incremental dynamic CT

PURPOSE

To use incremental dynamic computed tomography (CT) to evaluate solitary pulmonary nodules (SPNs).

MATERIALS AND METHODS

Thirty-two adult patients with SPNs less than 3 cm in diameter had 18 primary lung cancers, 10 tuberculomas, and four hamartomas. The CT numbers of the inner area of the nodule were calculated before and 30 seconds, 2 minutes, and 5 minutes after administration of contrast material.

RESULTS

All lung cancers and one of four hamartomas showed significantly greater enhancement (P < .0001) than benign SPNs, which did not show enhancement (except for one hamartoma). All lung cancers and one of four hamartomas showed complete enhancement, one hamartoma showed peripheral enhancement, two hamartomas and eight of 10 tuberculomas showed capsular enhancement, and two tuberculomas showed no enhancement.

CONCLUSION

Maximum attenuation of 20-60 HU appears to be a good predictor of malignancy.

Sequential-replenishment mechanism of exocytosis in pancreatic acini

Here we report exocytosis of zymogen granules, as examined by multiphoton excitation imaging in intact pancreatic acini. Cholecystokinin induces Ca 2+ oscillations that trigger exocytosis when the cytosolic Ca 2+ concentration exceeds 1 microM. Zymogen granules fused with the plasma membrane maintain their Omega-shaped profile for an average of 220 s and serve as targets for sequential fusion of granules that are located within deeper layers of the cell. This secondary exocytosis occurs as rapidly as the primary exocytosis and accounts for most exocytotic events. Granule-granule fusion does not seem to precede primary exocytosis, indicating that secondary fusion events may require a plasma-membrane factor. This sequential-replenishment mechanism of exocytosis allows the cell to take advantage of a large supply of fusion-ready granules without needing to transport them to the plasma membrane.

Mechanism of dimer formation of the 90-kDa heat-shock protein

This study describes the mechanism of homodimer formation of the 90-kDa heat-shock protein (HSP90). In eukaryotic cells, there are two HSP90 isoforms, alpha and beta, encoded by two separate genes. HSP90 alpha exists predominantly as a homodimer, HSP90 beta mainly as a monomer. Analysis by native PAGE revealed that bacterially expressed HSP90 alpha fused to glutathione S-transferase (GST) existed as a high-molecular-mass oligomer, and was converted to a homodimer following removal of the fusion enzyme by thrombin cleavage. A deletion mutant, HSP90 alpha D44-603, formed a monomer and an N-terminal truncated mutant, HSP90 alpha 533-732, existed as a dimer, indicating that the dimer-forming ability resides somewhere in the C-terminal 200 amino acids. Limited proteolysis of the C-terminal 200 amino acids of HSP90 alpha with chymotrypsin produced the C-terminal 16-kDa fragment (Met628/Ala629-Asp732) and its adjacent more N-terminal 13-kDa fragment (Val542-Tyr627/Met628). Size-exclusion HPLC and two-dimensional PAGE analyses demonstrated that these two chymotryptic fragments bound each other. The C-terminal 198 amino acids as well as the full-length form of HSP90 beta revealed a lower dimer-forming activity than HSP90 alpha. Expression of the chimeric proteins at the C-terminal 198 amino acids of the alpha and beta isoforms further indicated that the 16 amino acid substitutions locating between amino acids 561 and 685 account for the impeded dimerization of HSP90 beta. A leucine zipper motif (Met402-Leu423) was unlikely to be involved in the dimer formation. Taken together, these results indicate that the dimeric structure of HSP90 alpha is mediated by the C-terminal 191 amino acids and consists of duplicate interactions of the C-terminal region (Met628/Ala629-Asp732) of one subunit and the adjacent more N-terminal region (Val542-Try627/Met628) of the other subunit.

Social context of HIV risk behaviours among male-to-female transgenders of colour

To explore the social context of drug use and sexual behaviours that put male-to-female (MTF) transgenders at risk for HIV, focus groups were conducted consisting of African American, Latina and Asian and Pacific Islander MTF transgenders (N = 48) who reside or work in San Francisco, California. Participants were likely to report having unprotected sex with primary partners to signify love and emotional connection, as well as to receive gender validation from their partners. In contrast, viewing sex work with customers as a business encouraged intentious to use condoms. Safer sex intentions with customers were frequently undermined by urgent financial needs, which stemmed from transphobia, employment discrimination and costly procedures associated with gender transition. Participants reported using drugs as a way to cope with or escape life stresses associated with relationships, sex work, transphobia and financial hardship. Interventions with at-risk MTF transgenders should address the interpersonal and social context of unsafe sex and drug use, particularly the unique roles of relationship issues with male partners, stigma, discrimination and community norms regarding sex work and drug use.

Catalytic asymmetric epoxidation of enones using La-BINOL-triphenylarsine oxide complex: structural determination of the asymmetric catalyst

The catalytic asymmetric epoxidation of enones using the La-BINOL-Ph(3)As=O complex generated from La(O-i-Pr)(3), BINOL, and Ph(3)As=O in a ratio of 1:1:1 is described herein. Using 1-5 mol % of the asymmetric catalyst, a variety of enones, including a dienone and a cis-enone, were found to be epoxidized in a reasonable reaction time, providing the corresponding epoxy ketones in up to 99% yield and with more than 99% ee. The possible structure of the actual asymmetric catalyst has been clarified by various methods, including X-ray crystal structure analysis. This is the first X-ray analysis of an alkali-metal free lanthanoid-BINOL complex. Although La(binaphthoxide)(2)(Ph(3)As=O)(2) (7) was observed as the major complex in the complexes' solution, generated from La(O-i-Pr)(3), BINOL, and Ph(3)As=O in a ratio of 1:1:1, the possible active species turned out to be the La-BINOL-Ph(3)As=O complex in a ratio of 1:1:1. A probable reaction mechanism of the catalytic asymmetric epoxidation of enones is also proposed, suggesting that preferential formation of a heterochiral complex is the reason for asymmetric amplification. Moreover, the interesting role of La(O-i-Pr)(3) for accelerating the epoxidations while maintaining high ee's is discussed.

Stabilization of Exocytosis by Dynamic F-actin Coating of Zymogen Granules in Pancreatic Acini

Reorganization of F-actin in the apical region of mouse pancreatic acinar cells during Ca(2+)-dependent exocytosis of zymogen granules was investigated by two-photon excitation microscopy with intact acini. Granules were rapidly coated with F-actin in response to either agonist stimulation or photolysis of a caged-Ca(2+) compound. Such F-actin coating occurred exclusively at the surface of granules undergoing exocytosis and was prevented either by latrunculin-A, which inhibits actin polymerization, or by Clostridium botulinum exoenzyme C3, which inhibits the small GTPase Rho. Latrunculin-A or exoenzyme C3 also triggered the formation of vacuoles in acinar cells, a characteristic of acute pancreatitis. Stimulation of acini with high concentrations of cholecystokinin, which cause acute pancreatitis in mice, also impaired the F-actin coating of granules and induced vacuole formation. Latrunculin-A reduced the latency to exocytosis but did not affect the total number of exocytic events, suggesting that F-actin slows and further stabilizes exocytosis by facilitating F-actin coating. Rho-dependent F-actin coating of granule membranes thus stabilizes exocytic structures and is necessary for physiological progression of sequetial compound exocytosis in the exocrine pancreas and for prevention of acute pancreatitis.

HIV risk behaviours among male-to-female transgenders in comparison with homosexual or bisexual males and heterosexual females

Issues and concerns among six directors, one counsellor and one consultant for transgender programmes in San Francisco are described. Additionally, 173 clients who were enrolled in programmes in eight AIDS service organizations were interviewed using a structured survey questionnaire. This study examined the relationships between HIV risk behaviours and social and cognitive factors among transgendered females (male-to-female transgenders) (n = 25) in comparison with homosexual or bisexual males (n = 122) and heterosexual females (n = 26). Transgendered females engaged in riskier behaviours than the other groups in terms of the number of sex partners in the past 30 days and the past six months, commercial sex activities, and having a steady sex partner who injected drugs. Adverse socioeconomic conditions and transgender-specific risk behaviours such as injecting hormones in relation to HIV risk behaviours must be targeted by future intervention studies.

Axillary lymph node metastasis from an occult breast cancer

Twenty-nine cases were reviewed in which carcinoma manifested first as the enlargement of an axillary node from an occult breast carcinoma. A small hidden breast cancer was identified in 16 patients. In the remaining 13, the breast tumor was never discovered. Regardless of whether the primary tumors were discovered, the metastasis-free survival rates were comparable to those of patients with breast carcinoma with axillary nodal metastasis. The authors recommend that carcinoma found in an axillary node should be treated as a breast cancer, even in the absence of the breast tumor. Extensive investigative procedures in an attempt to uncover an extramammary primary site were largely unproductive and should either be omitted or performed selectively. Mammography, if positive or suspicious, can lead to the primary tumor in 75% of the patients, but, when negative, it does not necessarily exclude the breast as the source of the carcinoma. A carcinoma of the breast was found by pathologic examination in 44% of the patients with negative mammograms.

A rapid optical clearing protocol using 2,2'-thiodiethanol for microscopic observation of fixed mouse brain

Elucidation of neural circuit functions requires visualization of the fine structure of neurons in the inner regions of thick brain specimens. However, the tissue penetration depth of laser scanning microscopy is limited by light scattering and/or absorption by the tissue. Recently, several optical clearing reagents have been proposed for visualization in fixed specimens. However, they require complicated protocols or long treatment times. Here we report the effects of 2,2'-thiodiethanol (TDE) solutions as an optical clearing reagent for fixed mouse brains expressing a yellow fluorescent protein. Immersion of fixed brains in TDE solutions rapidly (within 30 min in the case of 400-µm-thick fixed brain slices) increased their transparency and enhanced the penetration depth in both confocal and two-photon microscopy. In addition, we succeeded in visualizing dendritic spines along single dendrites at deep positions in fixed thick brain slices. These results suggest that our proposed protocol using TDE solution is a rapid and useful method for optical clearing of fixed specimens expressing fluorescent proteins.

Overexpression of protein tyrosine kinases in human esophageal cancer

Using a PCR-based cloning technique, we isolated a series of protein tyrosine kinases (PTKs) expressed in a cell line of esophageal squamous cell carcinoma. Sequence analysis revealed 10 different kinds of PTKs of the receptor type [epidermal cell growth factor receptor, insulin-like growth factor I receptor, fibroblast growth factor receptor 4, eck, erk, discoidin domain receptor (DDR)/trkE/cell adhesion kinase (Cak), HEK2, HEK8, axl and sky] and one PTK of the nonreceptor type (tyk2). Subsequently, we examined the expression of the transcripts of these 11 genes in paired samples of normal and carcinomatous esophageal tissues obtained from 12 cases of esophageal cancer. We found that all 11 gene transcripts were expressed in both carcinomatous and normal tissues, and 6 of them were significantly overexpressed in carcinomatous tissues relative to adjacent normal tissues. Among these, the magnitude of mRNA expression of DDR/trkE/Cak PTK was positively correlated with the proliferative activity of carcinoma cells, but not with their degree of differentiation. Immunohistochemically, DDR was expressed in both normal and cancerous esophageal cells. The intensity of the expression was higher in cancer than normal tissue. In addition, we confirmed the expression of two isoforms of DDR/trkE/Cak in normal and cancerous esophagus. Our study suggests that DDR/trkE/Cak plays an important role in the regulation of proliferation of esophageal cancer.

Race-related differences in breast cancer patients. Results of the 1982 national survey of breast cancer by the American College of Surgeons

Data from the 1982 breast cancer survey of the American College of Surgeons were used to evaluate factors related to clinical, epidemiologic, and survival differences between black and white patients. Breast cancer in blacks was not discovered as early as in whites. Distribution of pathologic types of tumors were similar for both races with the exception of medullary carcinoma, which was more frequent in blacks than in whites. Estrogen receptor-positive tumors were found significantly less frequently in blacks compared with whites. Survival was better for whites compared with blacks within each axillary nodes group 0, 1 to 3, and 4+. Black women with negative or positive estrogen receptors had lower survival rates than white women of the same receptor status. A regression analysis using Cox's proportional hazards model showed race, clinical stage or axillary nodal status, age at diagnosis, and estrogen receptor status as significant predictors of survival. Significant differences between black and white patients were also observed with respect to the report of family history of breast cancer, age at first pregnancy, number of pregnancies, and age at cessation of menses.

Breast cancer and dietary and plasma concentrations of carotenoids and vitamin A

A case-control study of breast cancer was conducted in Buffalo. Participants completed a food frequency questionnaire and donated a fasting blood sample before definitive workup for breast masses. Dietary and plasma concentrations of carotenoids and retinol for 83 women found to have breast cancer were compared with those of 113 women found to be free of breast cancer (control subjects). There were no case-control differences in dietary estimates of vitamin A intake or in plasma alpha-carotene and lycopene. However, subjects with breast cancer had lower concentrations of plasma beta-carotene than did control subjects (P = 0.02). There was no overall association between plasma retinol and breast cancer but a positive relationship was observed between retinol and breast cancer in the subgroup with low beta-carotene values. These results suggest that low plasma beta-carotene is associated with increased risk of breast cancer. Other studies will need to determine whether low carotene concentrations are a subtle effect of the disease or might be causally related to breast cancer.

Loss of syndecan-1 and increased expression of heparanase in invasive esophageal carcinomas

Heparan sulfate proteoglycans play important biological roles in cell-cell and cell-matrix adhesion, and are closely associated with growth factor actions. Loss of syndecan-1, a cell surface-bound heparan sulfate proteoglycan, has been reported for advanced head and neck carcinomas, and expression of endoglycosidic heparanase, which cleaves heparan sulfate glycosaminoglycans (HS-GAGs), is associated with invasion and metastatic potential of malignant tumors. Paraffin sections of 103 primary esophageal squamous cell carcinomas were immunohistochemically examined for the expression of syndecan-1 core protein, HS-GAGs and heparanase protein, and the results were compared with various clinicopathological parameters, such as invasion depth. For 16 cases, fresh tumor samples were quantitatively analyzed for heparanase and syndecan-1 mRNA expression by real-time RT-PCR in addition to the immunohistochemical studies. Syndecan-1 core protein and HS-GAGs expression was significantly decreased in pT2 and pT3 cases compared with their pTis and pT1 counterparts. Decreased expression of core protein and HS-GAGs was correlated with the incidence of lymphatic invasion, and venous involvement. Furthermore, decreased expression of HS-GAGs was correlated positively with the incidence of nodal metastasis and distant organ metastasis, and negatively with the grade of tumor cell differentiation. The percentage of cytoplasmic heparanase protein-positive cases increased significantly in pT2 and pT3 cases compared to that in pTis and pT1 cases, and this was associated with lymphatic invasion, and venous and lymph nodal involvement. The level of heparanase mRNA was inversely correlated with the degree of HS-GAGs expression rather than core protein. In conclusion, loss of syndecan-1 and heparanase overexpression in esophageal squamous cell carcinomas are closely associated with malignant potential. Regarding the mechanism of loss of HS-GAGs, heparanase upregulation appears to play an important role.

Acute up-regulation of brain-derived neurotrophic factor expression resulting from experimentally induced injury in the rat spinal cord

Brain-derived neurotrophic factor (BDNF), a member of the nerve growth factor family of trophic factors, has multiple functions including a role in the promotion of neuronal survival and nerve fiber elongation in both the central and the peripheral nervous systems. We assessed the expression of endogenous BDNF following an experimentally induced compression injury to the spinal cord. Expression of BDNF mRNA was increased following the spinal cord injury; reaching maximum levels 24 h after the injury. Expression of BDNF mRNA returned to the levels observed in sham-operated control animals within 3 days of the injury. Using the in situ hybridization technique, we observed a wide distribution of BDNF expression among the different cell types in the spinal cord, including motor and sensory neurons, and in glia cells, including astrocytes. We also observed expression of BDNF in putative macrophages and/or microglia; however, this effect was not observed until day 7 following spinal cord injury. These results suggest that BDNF is synthesized in both neurons and astrocytes during the acute response to injury to the spinal cord, functioning in a mainly neuroprotective role. This is followed by a later phase of expression in which BDNF is produced by macrophages and/or microglia, apparently functioning in a restorative capacity.

Constitutive phosphorylation and nuclear localization of Smad3 are correlated with increased collagen gene transcription in activated hepatic stellate cells

Hepatic stellate cells (HSC) are the main producers of type I collagen in fibrotic liver, and transforming growth factor-beta (TGF-beta) plays critical roles in stimulating collagen gene expression in the cells mainly at the level of transcription. We have previously identified an upstream sequence of alpha2(I) collagen gene (COL1A2) that is essential for its basal and TGF-beta-stimulated transcription in skin fibroblasts and HSC. We designated this region the TGF-beta-responsive element (TbRE). Recently Smad3, an intracellular mediator of TGF-beta signal transduction, has been shown to bind to the TbRE and stimulate COL1A2 transcription when overexpressed in skin fibroblasts. In the present study, we demonstrate increased transcription of COL1A2 and plasminogen activator inhibitor-1 (PAI-1) genes and low response to TGF-beta in an activated HSC clone derived from a cirrhotic liver. Western blot analyses indicated constitutive phosphorylation of Smad3 in the cells. Immunofluorescence studies revealed that, in contrast to Smad2 that translocated from the cytoplasm to the nucleus upon TGF-beta treatment, Smad3 and Smad4 were present in the nucleus irrespective of ligand stimulation. Increased COL1A2 and PAI-1 gene transcription in the cells was not affected by overexpression of inhibitory Smad7. Altogether, the results correlate abnormality in TGF-beta/Smad signaling with pathologically accelerated collagen gene transcription in activated HSC.