Ajuba, a novel LIM protein, interacts with Grb2, augments mitogen-activated protein kinase activity in fibroblasts, and promotes meiotic maturation of Xenopus oocytes in a Grb2- and Ras-dependent manner

LIM domain-containing proteins contribute to cell fate determination, the regulation of cell proliferation and differentiation, and remodeling of the cell cytoskeleton. These proteins can be found in the cell nucleus, cytoplasm, or both. Whether and how cytoplasmic LIM proteins contribute to the cellular response to extracellular stimuli is an area of active investigation. We have identified and characterized a new LIM protein, Ajuba. Although predominantly a cytosolic protein, in contrast to other like proteins, it did not localize to sites of cellular adhesion to extracellular matrix or interact with the actin cytoskeleton. Removal of the pre-LIM domain of Ajuba, including a putative nuclear export signal, led to an accumulation of the LIM domains in the cell nucleus. The pre-LIM domain contains two putative proline-rich SH3 recognition motifs. Ajuba specifically associated with Grb2 in vitro and in vivo. The interaction between these proteins was mediated by either SH3 domain of Grb2 and the N-terminal proline-rich pre-LIM domain of Ajuba. In fibroblasts expressing Ajuba mitogen-activated protein kinase activity persisted despite serum starvation and upon serum stimulation generated levels fivefold higher than that seen in control cells. Finally, when Ajuba was expressed in fully developed Xenopus oocytes, it promoted meiotic maturation in a Grb2- and Ras-dependent manner.

Overexpression of CALNUC (nucleobindin) increases agonist and thapsigargin releasable Ca2+ storage in the Golgi

We previously demonstrated that CALNUC, a Ca2+-binding protein with two EF-hands, is the major Ca2+-binding protein in the Golgi by 45Ca2+ overlay (Lin, P., H. Le-Niculescu, R. Hofmeister, J.M. McCaffery, M. Jin, H. Henneman, T. McQuistan, L. De Vries, and M. Farquhar. 1998. J. Cell Biol. 141:1515-1527). In this study we investigated CALNUC's properties and the Golgi Ca2+ storage pool in vivo. CALNUC was found to be a highly abundant Golgi protein (3.8 microg CALNUC/mg Golgi protein, 2.5 x 10(5) CALNUC molecules/NRK cell) and to have a single high affinity, low capacity Ca2+-binding site (Kd = 6.6 microM, binding capacity = 1.1 micromol Ca2+/micromol CALNUC). 45Ca2+ storage was increased by 2.5- and 3-fold, respectively, in HeLa cells transiently overexpressing CALNUC-GFP and in EcR-CHO cells stably overexpressing CALNUC. Deletion of the first EF-hand alpha helix from CALNUC completely abolished its Ca2+-binding capability. CALNUC was correctly targeted to the Golgi in transfected cells as it colocalized and cosedimented with the Golgi marker, alpha-mannosidase II (Man II). Approximately 70% of the 45Ca2+ taken up by HeLa and CHO cells overexpressing CALNUC was released by treatment with thapsigargin, a sarcoplasmic/endoplasmic reticulum calcium ATPase (SERCA) (Ca2+ pump) blocker. Stimulation of transfected cells with the agonist ATP or IP3 alone (permeabilized cells) also resulted in a significant increase in Ca2+ release from Golgi stores. By immunofluorescence, the IP3 receptor type 1 (IP3R-1) was distributed over the endoplasmic reticulum and codistributed with CALNUC in the Golgi. These results provide direct evidence that CALNUC binds Ca2+ in vivo and together with SERCA and IP3R is involved in establishment of the agonist-mobilizable Golgi Ca2+ store.

[An HGPRT defective mouse lung cancer cell line and its biological characteristics.]

BACKGROUND

To provide antigenic cells suitable for cell fusion to preparing lung cancer vaccine.

METHODS

An HGPRT (hypoxanthine guanidine phosphoribosyl transferase)-defective cell line , ALA9702 , was gradually induced by 8-azaguanine (8-AG) from mouse lung cancer cell line , LA795 . The biological characteristics and carcinogenicity of ALA9702 cells have been appraised both in vivo and in vitro.

RESULTS

ALA9702 cells have been cultured over one year in medium containing 20mug/ml 8-AG, and maintained their biologic characteristics and carcinogenicity of the original cells , LA795 cells.

CONCLUSIONS

ALA9702 cell line presents as stabile HGPRT-defective mouse lung cancer cell. It will provide useful antigenic cells for establishment of effective specific lung cancer vaccine therapy.

Complications of laparoscopy. Strategies for prevention and cure

With a detailed knowledge of pelvic anatomy, familiarity with the many laparoscopic instruments, and attention to the details of good technique, many of the complications of laparoscopy described in this article can be avoided. The information presented complements that in the other articles in this issue and briefly summarizes many salient lessons already published in other excellent texts. The focus is on the most common laparoscopic complications, namely, those associated with insufflation and trocar insertion, such as vascular injury and bowel perforation. Other complications that may arise during adhesiolysis, removal of and bleeding from an ectopic pregnancy, and specimen removal from the abdomen are also discussed.

Properties of filament-bound myosin light chain kinase

Myosin light chain kinase binds to actin-containing filaments from cells with a greater affinity than to F-actin. However, it is not known if this binding in cells is regulated by Ca2+/calmodulin as it is with F-actin. Therefore, the binding properties of the kinase to stress fibers were examined in smooth muscle-derived A7r5 cells. Full-length myosin light chain kinase or a truncation mutant lacking residues 2-142 was expressed as chimeras containing green fluorescent protein at the C terminus. In intact cells, the full-length kinase bound to stress fibers, whereas the truncated kinase showed diffuse fluorescence in the cytoplasm. After permeabilization with saponin, the fluorescence from the truncated kinase disappeared, whereas the fluorescence of the full-length kinase was retained on stress fibers. Measurements of fluorescence intensities and fluorescence recovery after photobleaching of the full-length myosin light chain kinase in saponin-permeable cells showed that Ca2+/calmodulin did not dissociate the kinase from these filaments. However, the filament-bound kinase was sufficient for Ca2+-dependent phosphorylation of myosin regulatory light chain and contraction of stress fibers. Thus, dissociation of myosin light chain kinase from actin-containing thin filaments is not necessary for phosphorylation of myosin light chain in thick filaments. We note that the distance between the N terminus and the catalytic core of the kinase is sufficient to span the distance between thin and thick filaments.

Increased activation of Ras in psoriatic lesions

Ras functions as an essential upstream regulator of growth-factor-receptor-coupled signal transduction pathways. Ras is converted from an inactive GDP-bound state to an active GTP-bound state in response to receptor activation. Thus, the ratio of GTP/GDP bound to Ras is a measure of its state of activation. Mutations that stabilize the GTP-bound form of Ras result in constitutive activation and cellular transformation. The most widely used method for measuring Ras activation utilizes [32P]PO4 to label cellular nucleotide pools and is therefore limited to use with cultured cells. We have modified and adapted an enzyme-based method for rapid, precise measurement of Ras-bound GTP and GDP in normal and psoriatic human skin. This method does not require radiolabeling of cellular nucleotides. In cultured fibroblasts, the enzymatic and [32P]PO4 incorporation methods yielded similar results. Application of the enzymatic method to human skin revealed that 6% of Ras was in the active GTP-bound state in normal skin, compared to 15.4% of Ras in psoriatic lesions. The total amount of Ras normalized to protein content was similar in normal and psoriatic skin. Enhanced activation of Ras is likely a critical mediator of the increased cell growth characteristic of psoriatic lesions.

p53 codon 72 polymorphism in Taiwanese lung cancer patients: association with lung cancer susceptibility and prognosis

An association between the BstUI (Pro/Pro) genotype of the p53 codon 72 polymorphism and lung cancer has been reported previously (X. Jin et al., Carcinogenesis (Lond.), 16: 2205-2208, 1995). However, the genotype distribution of p53 codon 72 polymorphism as well as the association of this polymorphism with lung cancer risk and prognosis remain undefined in the Taiwanese population. Therefore, we investigated the genotype distribution of p53 codon 72 polymorphism in 194 lung cancer patients and 152 noncancer controls. The genotype frequencies in Taiwanese noncancer controls were 0.56 (Arg) and 0.44 (Pro). Chi2 analysis indicated significant differences in genotype distribution of p53 from other reports in Swedish (P < 0.001), Spanish (P < 0.001), Caucasians in the United States (P = 0.002), and African-Americans (P = 0.027). In addition, our data suggest that the Pro allele of the p53 codon 72 polymorphism increased the risk of lung cancer among female Taiwanese. The female patients with genotype Pro/Pro showed a significantly increased odds ratio (3.14; confidence interval, 1.48-6.64; P = 0.003) of having lung adenocarcinoma, compared with normal controls with the other genotypes. Patients with the Pro/Pro genotype had an odds ratio of 2.63 (confidence interval, 1.22-5.68; P = 0.01) higher than those with the other genotypes to be diagnosed with lung cancer at the early ages. We further investigated the association of p53 codon 72 polymorphism with prognosis in 133 lung cancer patients. Patients with the Pro/Pro genotype tended to have poorer prognosis than those with the Arg/Pro genotype (P = 0.05, by the log-rank test). Our data suggested that p53 codon 72 polymorphism may play a role in cancer susceptibility and prognosis in specific classes of lung cancer patients in Taiwan.

A 25,000-year tropical climate history from bolivian ice cores

Ice cores that were recovered from the summit of Sajama mountain in Bolivia provide carbon-14-dated tropical records and extend to the Late Glacial Stage (LGS). Oxygen isotopic ratios of the ice decreased 5.4 per mil between the early Holocene and the Last Glacial Maximum, which is consistent with values from other ice cores. The abrupt onset and termination of a Younger Dryas-type event suggest atmospheric processes as the probable drivers. Regional accumulation increased during the LGS, during deglaciation, and over the past 3000 years, which is concurrent with higher water levels in regional paleolakes. Unlike polar cores, Sajama glacial ice contains eight times less dust than the Holocene ice, which reflects wetter conditions and extensive snow cover.

[Chemoprevention of esophageal cancer]

OBJECTIVE

Our goal was to test and pursue the achievement achieved in Heshun township of Linxian county, Henan province. Since 1992, we have been conducting block therapy for precancerous lesions of the esophagus in 9 townships of Ci county, Hebei province, a high risk area of esophageal cancer.

METHODS

By means of a cytological survey, 3,990 and 5,346 cases of severe and mild dysplasia of esophageal epithelium were selected. These cases are divided randomly into the treated group and the control group. In the treated group, the Chinese herbal medicine Zeng Sheng Ping were given to the patients with severe dysplasia, and tablets of riboflavin Calcium were given to the patients with mild dysplasia. Placebo were given to the control group. After administration of drugs for 3 years, the esophageal cytological reexamination was repeated in July 1996.

RESULTS

In the severe dysplasia treated group, RR = 0.50, 95% CI = 0.33-0.75, inhibitory rate of canceration 49.9%; using the method of cytological five grade-six kinds as the mark of standard to calculate the general grade effects, and using the control group as the standard group, the treated group Ridit = 0.58, 95% CI = 0.56-0.60; in the mild dysplasia treated group, RR = 0.80, 95% CI = 0.52-1.22, inhibitory rate 20.4%; Ridit = 0.59, 95% CI = 0.57-0.61.

CONCLUSIONS

These herbal blocking results indicated that the effects of the Chinese herbal medicine Zeng Sheng Ping on esophageal precancerous lesions were worthy of being highly considered.

BOD (Bcl-2-related ovarian death gene) is an ovarian BH3 domain-containing proapoptotic Bcl-2 protein capable of dimerization with diverse antiapoptotic Bcl-2 members

Using the yeast two-hybrid protein-protein interaction system to search for genes capable of forming dimers with the antiapoptotic protein Mcl-1, we have isolated BOD (Bcl-2-related ovarian death agonist) from an ovarian fusion cDNA library. The three variants of BOD (long, medium, and short) have an open reading frame of 196, 110, and 93 amino acids, respectively; all of them contain a consensus Bcl-2 homology 3 (BH3) domain but lack other BH domains found in channel-forming Bcl-2 family proteins. In the yeast cell assay, BOD interacts with diverse antiapoptotic Bcl-2 proteins [Mcl-1, Bcl-2, Bcl-xL, Bcl-w, Bfl-1, and Epstein-Barr virus (EBV) BHRF-1] but not with different proapoptotic Bcl-2 proteins (BAD, Bak, Bok, and Bax). After overexpression in mammalian Chinese hamster ovary (CHO) cells, BOD induces apoptosis that can be prevented by the baculoviral caspase inhibitor P35. The cell-killing activity of BOD is also antagonized in cells cotransfected with the antiapoptotic Bcl-w protein, which showed high affinity for BOD in the two-hybrid assay. Furthermore, mutagenesis studies showed that BOD mutants with alterations in the BH3 domain lose cell-killing ability, suggesting that the BH3 domain is important for the mediation of cell killing by BOD. BOD mRNA is ubiquitously expressed in ovary and multiple other tissues. The BOD gene is also conserved in diverse mammalian species. Identification of BOD expands the group of proapoptotic Bcl-2 proteins that only contains the BH3 domain and allows future elucidation of the intracellular mechanism for apoptosis regulation in ovary and other tissues.

Water permeation barrier in isolated cutaneous newborn rat epidermis

Abnormal water barrier function occurs in irritated skin and certain cutaneous diseases. Methods have been compared for separating the epidermis (site of the barrier) from the whole skin without disturbing the barrier function. The epidermis was separated from newborn rat skin by (1) exposure to 10% trypsin at 4 degrees C for 16 h, (2) exposure to 0.2% dispase at 4 degrees C for 16 h, (3) heating for 50 s at 55 degrees C, (4) or heating for 40 s at 50 degrees C after the whole skin was kept in medium at the air-liquid interface for 1 day at 35 degrees C. Water permeation of the isolated epidermis was then measured immediately or after 3, 5, 8, and 10 days of maintenance at the air-liquid interface. The water permeation barrier constant (kp) was 1.9+/-0.9 cm/h in intact rat skin. At 0 day of maintenance, the kp of the epidermis was 2.1+/-0.9 after treatment with trypsin, 3.8+/-1.2 after dispase, and 4.3+/-1.4 after immediate heating, or 2.2+/-0.7 cm/h after culture and heating. The dispase and heating methods disrupted the barrier to a greater extent than did the trypsin and culture-heating methods. The latter two methods allowed the kp to be maintained at low levels for 8 days (kp for trypsin 2.8+/-0.9 and 2.5+/-0.8 for culture-heating). Epidermis isolated by the trypsin or culture-heating techniques and maintained at the air-liquid interface can be used to study the mechanism by which barrier function is disrupted by chemicals.

BOD (Bcl-2-related ovarian death gene) is an ovarian BH3 domain-containing proapoptotic Bcl-2 protein capable of dimerization with diverse antiapoptotic Bcl-2 members

Using the yeast two-hybrid protein-protein interaction system to search for genes capable of forming dimers with the antiapoptotic protein Mcl-1, we have isolated BOD (Bcl-2-related ovarian death agonist) from an ovarian fusion cDNA library. The three variants of BOD (long, medium, and short) have an open reading frame of 196, 110, and 93 amino acids, respectively; all of them contain a consensus Bcl-2 homology 3 (BH3) domain but lack other BH domains found in channel-forming Bcl-2 family proteins. In the yeast cell assay, BOD interacts with diverse antiapoptotic Bcl-2 proteins [Mcl-1, Bcl-2, Bcl-xL, Bcl-w, Bfl-1, and Epstein-Barr virus (EBV) BHRF-1] but not with different proapoptotic Bcl-2 proteins (BAD, Bak, Bok, and Bax). After overexpression in mammalian Chinese hamster ovary (CHO) cells, BOD induces apoptosis that can be prevented by the baculoviral caspase inhibitor P35. The cell-killing activity of BOD is also antagonized in cells cotransfected with the antiapoptotic Bcl-w protein, which showed high affinity for BOD in the two-hybrid assay. Furthermore, mutagenesis studies showed that BOD mutants with alterations in the BH3 domain lose cell-killing ability, suggesting that the BH3 domain is important for the mediation of cell killing by BOD. BOD mRNA is ubiquitously expressed in ovary and multiple other tissues. The BOD gene is also conserved in diverse mammalian species. Identification of BOD expands the group of proapoptotic Bcl-2 proteins that only contains the BH3 domain and allows future elucidation of the intracellular mechanism for apoptosis regulation in ovary and other tissues.

Antiangiogenic gene therapy targeting the endothelium-specific receptor tyrosine kinase Tie2

Angiogenesis is required for tumor growth and metastasis, and inhibition of angiogenesis is a promising approach for anticancer therapy. Tie2 (a.k.a Tek) is an endothelium-specific receptor tyrosine kinase known to play a role in tumor angiogenesis. To explore the therapeutic potential of blocking the Tie2 pathway, an adenoviral vector was constructed to deliver a recombinant, soluble Tie2 receptor (AdExTek) capable of blocking Tie2 activation. Two days after i.v. injection of AdExTek, the plasma concentration of ExTek exceeded 1 mg/ml and was maintained for about 8 days. Administration of AdExTek to mice with two different well established primary tumors, a murine mammary carcinoma (4T1) or a murine melanoma (B16F10.9), significantly inhibited the growth rate of both tumors (64% and 47%, respectively). To study the effect of ExTek on tumor metastasis, both tumor cell lines were coinjected i.v. with either AdExTek or a control virus. Mice coinjected with control virus developed numerous large, well vascularized lung metastases. In contrast, mice coinjected with AdExTek virus developed few, if any, grossly apparent metastases, and histologic examination revealed only small avascular clusters of tumor cells. Administration of AdExTek also inhibited tumor metastasis when delivered at the time of surgical excision of primary tumors in a clinically relevant model of tumor metastasis. This study demonstrates the potential utility of gene therapy for systemic delivery of an antiangiogenic agent targeting an endothelium-specific receptor, Tie2.

The mammalian calcium-binding protein, nucleobindin (CALNUC), is a Golgi resident protein

We have identified CALNUC, an EF-hand, Ca2+-binding protein, as a Golgi resident protein. CALNUC corresponds to a previously identified EF-hand/calcium-binding protein known as nucleobindin. CALNUC interacts with Galphai3 subunits in the yeast two-hybrid system and in GST-CALNUC pull-down assays. Analysis of deletion mutants demonstrated that the EF-hand and intervening acidic regions are the site of CALNUC's interaction with Galphai3. CALNUC is found in both cytosolic and membrane fractions. The membrane pool is tightly associated with the luminal surface of Golgi membranes. CALNUC is widely expressed, as it is detected by immunofluorescence in the Golgi region of all tissues and cell lines examined. By immunoelectron microscopy, CALNUC is localized to cis-Golgi cisternae and the cis-Golgi network (CGN). CALNUC is the major Ca2+-binding protein detected by 45Ca2+-binding assay on Golgi fractions. The properties of CALNUC and its high homology to calreticulin suggest that it may play a key role in calcium homeostasis in the CGN and cis-Golgi cisternae.

Status of deleted in colorectal cancer gene expression correlates with neuroblastoma metastasis

Neuroblastoma is an embryonal tumor of neural crest origin noted for its heterogeneity at the clinical, histologic, and molecular levels. The deleted in colorectal cancer (DCC) protein is an adhesion family molecule of unequivocal importance in neural development that has also been implicated in several malignancies, including neuroblastoma, through its apparent loss of function. Immunohistochemical assessment of the DCC protein was performed on a group of 49 neuroblastoma specimens and examined in relation to important clinical, histologic, and molecular parameters. DCC expression was significantly associated with neuroblastoma dissemination as primary tumors from Stage 1 to 3 patients (15/20, 75%) more frequently exhibited the DCC protein than those from Stage 4 patients (5/13, 38%; p = 0.0415). Primary tumors were more frequently DCC-positive (20/33, 61%) as compared with metastatic deposits (3/16, 19%; p = 0.0063), and a single case of a paired primary and metastatic deposit demonstrated the apparent loss of DCC gene expression with tumor progression. The remaining five paired specimens were DCC-negative in both the primary tumor and metastatic deposit. No significant association was appreciated between DCC expression and patient age, the Shimada histologic classification, or N-Myc amplification. These results provide evidence that DCC expression may be lost in the course of metastatic spread in a subset of neuroblastomas. Moreover, DCC function is implicated in neuroblastoma dissemination in a manner independent of N-Myc.

[Adjuvant chemotherapy following radical surgery for non-small cell lung cancer: a randomized study]

OBJECTIVE

To evaluate the efficacy of adjuvant chemotherapy after radical surgery for non-small cell lung cancer (NSCLC).

METHODS

Seventy patients with NSCLC(stage I-III) undergone radical surgery were randomized into two groups: 35 patients received adjuvant chemotherapy with cyclophosphamide (CTX) 300 mg/m2, vincristine(VCR) 1.4 mg/m2, adriamycin(ADM) 50 mg/m2, d1; cisplatin (PDD) 20 mg/m2, d1-5, for 4 cycles, and followed by oral ftorafur (FT-207) 600-900 mg/d for 1 year (adjuvant chemotherapy group). The other 35 patients received surgical treatment only (surgery group).

RESULTS

The overall 5-year survival rate was 48.6% in the adjuvant chemotherapy group, and 31.4% in the surgery group, respectively. The difference between the two groups was not statistically significant (P > 0.05). The 5-year survival rate of patients in atage III was 44.0% and 20.8% (5/24) received surgery with and without adjuvant chemotherapy, respectively. The difference between the two groups was statistically significant (P < 0.025). The 5-year survival rate of patients in stage I-II in the two group was 60.0% and 54.5%, respectively (P > 0.75).

CONCLUSION

Postoperative adjuvant chemotherapy in NSCLC improves survival but only in patients in stage III, it results in significantly higher 5-year susvival rate than surgery alone.

DNA content and other factors associated with ten-year survival after resection of pancreatic carcinoma

BACKGROUND AND OBJECTIVES

The 5-year survival rates after resection of pancreatic carcinoma have recently increased and are predicted by tumor size, DNA content, and lymph node metastases at the time of resection. However, whether the 10-year survival rates have also increased and are similarly predicted by these factors is not known.

METHODS

The influence of preoperative imaging tests, alcohol consumption, cigarette smoking, K-ras mutations, anatomic location, details of surgical resection, pathologic findings, and tumor DNA content on survival was tested for 96 patients after a successful resection of a pancreatic carcinoma with 17 patients being followed for more than 5 years.

RESULTS

The 5- and 10-year patient survival rates were 18% and 3%, respectively. Univariate and multivariable analyses showed that tumor DNA content, pathologic tumor size, and lymph node metastases were the strongest prognostic indicators for long-term patient survival, although the importance of tumor size may diminish 2 or more years after resection. Surprisingly, the 11 patients with diploid carcinomas > or = 4 cm had an estimated 10-year survival rate of 36%.

CONCLUSION

These results show that the 10-year survival rate for pancreatic carcinoma remains very low, although the subset of patients with biologically favorable tumors has a prolonged survival and possible cure after resection.

Concentrations of carotenoids, tocopherols, and retinol in paired plasma and cervical tissue of patients with cervical cancer, precancer, and noncancerous diseases

Paired blood (collected after an overnight fast) and cervical tissue (cancerous, precancerous, and noncancerous) samples were obtained from 87 patients (age, 21-86 years) who had a hysterectomy or biopsy due to cervical cancer, precancer (cervical intraepithelial neoplasia I, II, and III), or noncancerous diseases. The samples were analyzed using high-performance liquid chromatography for 10 micronutrients (lutein, zeaxanthin, beta-cryptoxanthin, lycopene, alpha-carotene, beta-carotene, cis-beta-carotene, alpha-tocopherol, gamma-tocopherol, and retinol). The results indicated that: (a) among the three patient groups, the mean plasma concentrations of all micronutrients except gamma-tocopherol were lowest in the cancer patients; however, the mean tissue concentrations of the two tocopherols and certain carotenoids were highest in the cancerous tissue; and (b) among the 10 micronutrients, only the concentrations of beta-carotene and cis-beta-carotene were lower in both the plasma and tissue of cancer and precancer patients than in those of noncancer controls. These results suggest that: (a) not all of the micronutrient concentrations in plasma reflect the micronutrient concentrations in cervical tissue; thus, in some cases, it may be necessary to measure the tissue micronutrient concentrations to define the role of the micronutrients in cervical carcinogenesis; and (b) maintaining an adequate plasma and tissue concentration of beta-carotene may be necessary for the prevention of cervical cancer and precancer.

Retinoic acid inhibits induction of c-Jun protein by ultraviolet radiation that occurs subsequent to activation of mitogen-activated protein kinase pathways in human skin in vivo

Human skin is exposed daily to solar ultraviolet (UV) radiation. UV induces the matrix metalloproteinases collagenase, 92-kD gelatinase, and stromelysin, which degrade skin connective tissue and may contribute to premature skin aging (photoaging). Pretreatment of skin with all-trans retinoic acid (tRA) inhibits UV induction of matrix metalloproteinases. We investigated upstream signal transduction pathways and the mechanism of tRA inhibition of UV induction of matrix metalloproteinases in human skin in vivo. Exposure of human skin in vivo to low doses of UV activated EGF receptors, the GTP-binding regulatory protein p21Ras, and stimulated mitogen-activated protein (MAP) kinases, extracellular signal-regulated kinase (ERK), c-Jun amino-terminal kinase (JNK), and p38. Both JNK and p38 phosphorylated, and thereby activated transcription factors c-Jun and activating transcription factor 2 (ATF-2), which bound to the c-Jun promoter and upregulated c-Jun gene expression. Elevated c-Jun, in association with constitutively expressed c-Fos, formed increased levels of transcription factor activator protein (AP) 1, which is required for transcription of matrix metalloproteinases. Pretreatment of human skin with tRA inhibited UV induction of c-Jun protein and, consequently, AP-1. c-Jun protein inhibition occurred via a posttranscriptional mechanism, since tRA did not inhibit UV induction of c-Jun mRNA. These data demonstrate, for the first time, activation of MAP kinase pathways in humans in vivo, and reveal a novel posttranscriptional mechanism by which tRA antagonizes UV activation of AP-1 by inhibiting c-Jun protein induction. Inhibition of c-Jun induction likely contributes to the previously reported prevention by tRA of UV induction of AP-1-regulated matrix-degrading metalloproteinases in human skin.

Solid-phase synthesis of peptidomimetic oligomers with a phosphodiester backbone

An unnatural biopolymer is described in which amino acid side-chains are presented along a negatively charged phosphodiester backbone. For this purpose, a series of phosphoramidite monomers was prepared from chiral 1,2-diols. These were efficiently converted into oligomers using standard coupling conditions on an automated DNA synthesizer.

Induction and maintenance of increased VEGF protein by chronic motor nerve stimulation in skeletal muscle

Vascular endothelial growth factor (VEGF) causes endothelial cell proliferation in vitro and angiogenesis in vivo. Glycolytic skeletal muscles have a lower capillary density than oxidative muscles but can increase their capillary density and convert to a more oxidative phenotype when subject to chronic motor nerve stimulation (CMNS). We used Western analysis and immunohistochemical techniques to examine VEGF protein in a rabbit CMNS model of glycolytic skeletal muscle and in muscles with innate glycolytic versus oxidative phenotypes. VEGF protein per gram of total protein was increased in stimulated vs. control muscles 2.9 +/- 1.0, 3.6 +/- 1.3, 3.1 +/- 0.5, 4.4 +/- 1.6, and 2.7 +/- 0.3 times after 3 (n = 4), 5 (n = 2), 10 (n = 3), 21 (n = 3), and 56 (n = 2) days, respectively. VEGF protein was increased 3.1 +/- 0.5 times (P < 0.005) before (3, 5, and 10 days) and remained elevated 3.7 +/- 1.0 times (P < 0.05) after (21 and 56 days) the transition to an oxidative phenotype. By immunohistochemistry, VEGF protein was found primarily in the matrix between stimulated muscle fibers but not in the myocytes. In addition, VEGF protein was consistently lower in innate glycolytic compared with oxidative muscles. These findings suggest that VEGF plays a role in the alteration and maintenance of vascular density in mammalian skeletal muscles.

DNA content and other factors associated with ten-year survival after resection of pancreatic carcinoma

BACKGROUND AND OBJECTIVES

The 5-year survival rates after resection of pancreatic carcinoma have recently increased and are predicted by tumor size, DNA content, and lymph node metastases at the time of resection. However, whether the 10-year survival rates have also increased and are similarly predicted by these factors is not known.

METHODS

The influence of preoperative imaging tests, alcohol consumption, cigarette smoking, K-ras mutations, anatomic location, details of surgical resection, pathologic findings, and tumor DNA content on survival was tested for 96 patients after a successful resection of a pancreatic carcinoma with 17 patients being followed for more than 5 years.

RESULTS

The 5- and 10-year patient survival rates were 18% and 3%, respectively. Univariate and multivariable analyses showed that tumor DNA content, pathologic tumor size, and lymph node metastases were the strongest prognostic indicators for long-term patient survival, although the importance of tumor size may diminish 2 or more years after resection. Surprisingly, the 11 patients with diploid carcinomas > or = 4 cm had an estimated 10-year survival rate of 36%.

CONCLUSION

These results show that the 10-year survival rate for pancreatic carcinoma remains very low, although the subset of patients with biologically favorable tumors has a prolonged survival and possible cure after resection.

Metastatic germ cell tumors: modeling for response to chemotherapy

PURPOSE

This study sought to determine factors that predict response to chemotherapy for patients with advanced germ cell tumors (GCTs), to evaluate different methods by which serum tumor markers can be used to predict response independent of assay method, and to develop criteria to guide allocation to clinical trials.

METHODS

Pretreatment data from 796 patients treated with platinum-based chemotherapy on Memorial Hospital protocols from 1975 to 1990 were analyzed. Multivariate analyses were performed on a developmental data set (n = 597) to assess for independently significant predictors of response. Predictive models developed using these methods were confirmed on the validation set (n = 199).

RESULTS

Independently significant factors for response included a mediastinal primary tumor (.015), pure seminomatous histology (.002), metastases to nonpulmonary visceral sites (bone, liver, and brain; .0001), and the pretreatment values of lactate dehydrogenase (LDH; .0001) and human chorionic gonadotropin (HCG; .0001). The likelihood of complete response (CR) was increased by seminomatous histology and decreased by the other factors. Serum levels of HCG and LDH could predict outcome independent of assay methodology. A model to predict good-, intermediate-, and poor-risk categories with CR rates of 92%, 76%, and 39%, respectively, was developed.

CONCLUSION

The independent prognostic factors of serum tumor markers LDH and HCG, the sites of metastases, and the primary origin of GCTs can predict outcome in patients with advanced GCT. These factors should be considered in the allocation of patients with advanced disease to clinical trials and have been included in the new tumor-node-metastasis (TNM) staging systems developed for the American Joint Committee on Cancer (AJCC) and the Union Internationale Contre le Cancer (UICC).

Inhibition of tumor growth by targeting tumor endothelium using a soluble vascular endothelial growth factor receptor

Vascular endothelial growth factor (VEGF) is a leading candidate for an endogenous mediator of tumor angiogenesis. Recently, two endothelial cell surface receptors, flk-1 and flt-1, have been shown to mediate the angiogenic activities of VEGF. In this study, we have evaluated whether a soluble VEGF receptor could suppress tumor angiogenesis and thereby inhibit tumor growth. A soluble VEGF receptor was constructed by fusing the entire extracellular domain of murine flk-1 to a six-histidine tag at the COOH terminus (ExFlk.6His). In vitro, recombinant ExFlk.6His protein bound VEGF with high affinity (Kd, 16 nM) and blocked receptor activation in a dose-dependent manner and inhibited VEGF-induced endothelial cell proliferation and migration. ExFlk.6His bound to endothelial cells only in the presence of VEGF, and cell surface cross-linking yielded a high molecular weight complex consistent with the VEGF-mediated formation of a heterodimer between ExFlk.6His and the endogenous VEGF receptor. In vivo, ExFlk.6His potently inhibited corneal neovascularization induced by conditioned media from a rat mammary carcinoma cell line (R3230AC). Moreover, when ExFlk.6His protein was administered into a cutaneous tumor window chamber concomitantly with R3230AC carcinoma transplants, tumor growth was inhibited by 75% (P < 0.005) and vascular density was reduced by 50% (P < 0.002) compared with control-treated tumors. These results demonstrate the potential of ExFlk.6His to inhibit VEGF action by a potent "dominant-negative" mechanism and suggest that targeting VEGF action using a soluble receptor may be an effective antiangiogenic therapy for cancer and other "angiogenic" diseases.

Analysis of mutationally altered forms of the Cct6 subunit of the chaperonin from Saccharomyces cerevisiae

The Cct double-ring chaperonin complex of Saccharomyces cerevisiae is comprised of eight essential subunits, Cct1p-Cct8p, and assists the folding of substrates such as actins and tubulins. Single and multiple amino acid replacements of Cct6p were constructed by oligonucleotide-directed mutagenesis, including changes of charged to alanine residues and uncharged to charged residues. The replacements were targeted, in part, to residues corresponding to functionally critical regions identified in the published crystal structure of the Escherichia coli chaperonin, GroEL. Here, we report the critical hydrophobic residues and clusters of hydrophilic residues in regions corresponding to those from the apical domain of GroEL implicated in peptide binding and peptide release, and certain residues in the putative equatorial domain implicated in subunit-to-subunit interaction. In contrast to their homologous counterparts in Cct2p and Cct1p, the highly conserved putative ATP binding motifs of Cct6p were relatively amenable to mutations. Our data suggest that the entire Cct6p molecule might be essential for assembly of Cct complex and might participate in binding substrates. However, there appeared to exist a functional hierarchy in ATP binding/hydrolysis among Cct subunits, as suggested by the high tolerance of Cct6p to mutations within the putative ATP binding pocket.

Neutralizing IGF-1 monoclonal antibody with cross-species reactivity

We report the generation of a murine IGF-1 monoclonal antibody designated 35I17, which exhibits unique cross-species reactivity. The antibody recognizes recombinant human and rat IGF-1 in ELISA, Western blots, and in an 125I-recombinant human IGF-1 Scintillation Proximity Assay. In addition, 35I17 blocks cell proliferation induced by recombinant human and rat IGF-1, and inhibits cell proliferation induced by sera from human, rat, calf, dog, goat, or mouse. The antibody inhibits rat IGF-1 binding to IGF-1 receptors, and prevents IGF-1-stimulated receptor and IRS-1 phosphorylation in LISN C4 cells, an IGF-1 receptor-transfected cell line. The cross-species and neutralizing properties of 35I17 may be useful in in vitro and in vivo animal studies for elucidating the role of IGF-1 in cancer, rheumatoid arthritis, and other diseases.

In vivo modification of the C-terminal lysine of human lens alphaB-crystallin

Both the structural and chaperone-like properties of lens alpha-crystallins have been implicated in maintaining lens transparency. Modifications of lens alpha-crystallins may lead to formation of cataract by affecting the close-packing of the crystallins or by reducing the chaperone-like activity of the alpha-crystallins. A previously unreported modified alphaB-crystallin, whose molecular weight is 72 u greater than unmodified alphaB-crystallin, has been isolated from human lenses by size exclusion chromatography, reversed phase HPLC and ion exchange HPLC. Approximately one nanomole of this modified alphaB-crystallin was obtained from each of five human eye lenses. Molecular weight determinations of peptides produced by digestion with trypsin or endoproteinase Asp-N showed that the modification is in the C-terminal region of alphaB-crystallin. The fragmentation pattern of peptides from the C-terminal region, analysed by tandem mass spectrometry, located the modification of the epsilon-amino group of the C-terminal lysine. The elemental composition of this modification, determined from its exact mass, is C3H4O2. Because this modification decreases the net charge of alphaB-crystallin by one unit, and because the C-terminus has been implicated in the chaperone activity attributed to alphaB-crystallin, this modification at Lys 175 may have a significant role in cataractogenesis.

Chromosome 19 single-locus and multilocus haplotype associations with multiple sclerosis. Evidence of a new susceptibility locus in Caucasian and Chinese patients

CONTEXT

Susceptibility to multiple sclerosis (MS) involves a genetically complex autoimmune component. However, except for genes in the HLA system, specific susceptibility loci are unknown or unconfirmed.

OBJECTIVE

To investigate several loci spanning 3 candidate regions for a role in multiple sclerosis (MS) susceptibility in 2 ethnic groups using both single-locus and haplotype analyses. The 3 regions include HLA on chromosome 6p21.3, APOE on chromosome 19ql 3.2, and MBP(myelin basic protein) on chromosome 18q23.

DESIGN

Case-control association testing.

SUBJECTS

A total of 120 Caucasian patients with MS and 107 unrelated control individuals from California, and 32 patients and 32 unrelated control individuals from Beijing, China. All patients with MS were diagnosed as having clinically definite disease according to published criteria.

MAIN OUTCOME MEASURES

Chi2 Testing of loci and individual alleles and haplotypes. Haplotype frequencies were estimated with standard maximum likelihood methods.

RESULTS

The HLA effect is due to the class II DR2 haplotype, DRB1*1501-DQA1*0102-DRB1*0602; contributions to MS susceptibility from additional DRB1-DQB1 alleles or other HLA region loci were not observed. Variation within the MBP locus on chromosome 18q23 showed no effect in MS. The distribution of haplotypes from 5 loci within the chromosome 19q13.2 region, including D19S178, D19S574, APOE, APOC2, and D19S219, differed between patient and control samples. D19S574 showed a significant effect (P=.015) in Caucasian patients with MS due to the increased frequency of a single allele (P=.002). The APOE variation, prominent in other neurological diseases, showed no influence on MS susceptibility, despite its location within the chromosome 19q13.2 region. Interaction effects between DR2 and chromosome 19q13.2 or MBP in MS susceptibility were not apparent.

CONCLUSIONS

The significant chromosome 19q13.2 single-locus and multilocus haplotype associations with MS in Caucasian and Chinese patient samples indicate an effect from a nearby disease susceptibility locus. These initial observations are an encouraging step toward the description of non-HLA genetic susceptibility to MS.

Inhibition of tumor angiogenesis using a soluble receptor establishes a role for Tie2 in pathologic vascular growth

Tie2 is a novel receptor tyrosine kinase that is expressed almost exclusively by vascular endothelium. Disruption of Tie2 function in transgenic mice resulted in embryonic lethality secondary to characteristic vascular defects; similar defects occurred after disruption of the Tie2 ligand. These findings indicate that the Tie2/Tie2 ligand pathway plays important roles during development of the embryonic vasculature. To determine whether the Tie2 pathway was involved in pathologic angiogenesis in adult tissues, a soluble form of the extracellular domain of murine Tie2 (ExTek.6His) was developed and used as a Tie2 inhibitor. After a single application of the ExTek.6His protein into a rat cutaneous window chamber, growth of a mammary tumor inside the chamber was reduced by > 75% (P < 0.005), and tumor vascular length density was reduced by 40% when compared with control-treated tumors (P < 0.01). In the rat cornea, ExTek.6His blocked angiogenesis stimulated by tumor cell conditioned media. ExTek.6His protein did not affect the viability of cultured tumor cells, indicating that the antitumor effect of ExTek.6His was due to the inhibition of tumor angiogenesis. These data demonstrate a role for the Tie2 pathway in pathologic angiogenesis, suggesting that targeting this pathway may yield effective antiangiogenic agents for treatment of cancer and other angiogenic diseases.

Does vaginal cuff closure decrease the infectious morbidity associated with abdominal hysterectomy?

BACKGROUND

Infectious morbidity after total abdominal hysterectomy includes fever (31%) and antibiotic administration (45%). Whether vaginal cuff closure reduces postoperative infectious morbidity remains unresolved.

STUDY DESIGN

We reviewed the records of 172 consecutive abdominal hysterectomies for nonmalignant disease performed at an inner-city hospital. We identified potential risk factors for infectious morbidity by univariate analysis and determined adjusted odds ratios by multiple logistic regression analysis.

RESULTS

The open vaginal cuff technique was associated with an increased risk of wound infection. Use of prophylactic antibiotics was associated with a decreased risk of febrile morbidity and a decreased risk of prolonged hospitalization. Body weight in the heaviest quartile was associated with increased risk of wound infection, increased risk of prolonged hospitalization, and decreased risk of postoperative vaginal cuff granulation tissue. Older age was associated with an increased risk of prolonged hospitalization.

CONCLUSIONS

Closure of the vaginal cuff and use of prophylactic antibiotics at total abdominal hysterectomy were associated with decreased infectious morbidity in a high-risk population.

[Reconstruction of the hypopharyngeal and cervical esophagus using flap of epiglottis]

Reconstruction of the hypopharyngeal and cervical esophagus was performed for eight patients after the resection of hypopharyngeal carcinoma. The flap of the epiglottis and the facial flap of the sternohyoid muscle or the uninvolved mucous membrane of the hypopharynx were used for the reconstruction of the hypopharyngeal and cervical esophagus. A good swallowing function was obtained. No pharyngeal-cervical fistula occurred. Although stomach transposition or colon interpolation and pectoralis major myocutaneous flap could be used to reconstruct the hypopharynx and the cervical esophagus, however, the operative time became longer, more complex and the patient suffered more. The procedure of the flap of epiglottis had the following advantages: (1) a rich vascularized flap; (2) simple operative technique; (3) higher success rate; and (4) few complications.

The unique hetero-oligomeric nature of the subunits in the catalytic cooperativity of the yeast Cct chaperonin complex

The structural and functional organization of the Cct complex was addressed by genetic analyses of subunit interactions and catalytic cooperativity among five of the eight different essential subunits, Cct1p-Cct8p, in the yeast Saccharomyces cerevisiae. The cct1-1, cct2-3, and cct3-1 alleles, containing mutations at the conserved putative ATP-binding motif, GDGTT, are cold-sensitive, whereas single and multiple replacements of the corresponding motif in Cct6p are well tolerated by the cell. We demonstrated herein that cct6-3 (L19S), but not the parolog cct1-5 (R26I), specifically suppresses the cct1-1, cct2-3, and cct3-1 alleles, and that this suppression can be modulated by mutations in a putative phosphorylation motif, RXS, and the putative ATP-binding pocket of Cct6p. Our results suggest that the Cct ring is comprised of a single hetero-oligomer containing eight subunits of differential functional hierarchy, in which catalytic cooperativity of ATP-binding/hydrolysis takes place in a sequential manner different from the concerted cooperativity proposed for GroEL.

[The shrinkage of ovarian and uterine size and the decline of serum estradiol level in post-menopausal women]

OBJECTIVE

To investigate the shrinkage of ovarian and uterine size, and the decline of serum estradiol (E2) level in normal women.

METHODS

Ovarian and uterine area of 92 perimenopausal and 292 postmenopausal women, measured by transvaginal ultrasonography, were analysed retrospectively and were compared with those of the controls consisting of 41 normal women in midfollicular phase, so did the serum E2 levels.

RESULTS

As compared with the control group, ovarian area and endometrium thickness shrunk on an average of 30%, 2% and 56%, 48% in early perimenopausal and postmenopausal groups respectively. Serum E2 level and uterine area increased by 11% and 38% in early perimenopausal group, but decreased by 67% and 21% in postmenopausal groups respectively. No obviously further decline of serum E2 level was found 1 year after menopause, and of ovarian, uterine area 3-5 years after menopause.

CONCLUSION

These data represent a normal profile of ovarian and uterine shrinkage and decline of serum E2 levels related to the time of menopause.

Bispecific humanized anti-IL-2 receptor alpha beta antibodies inhibitory for both IL-2- and IL-15-mediated proliferation

Humanized anti-Tac (HAT) and Mik beta1 (HuMik beta 1) Abs directed at IL-2R alpha and IL-2R beta, respectively, inhibit IL-2 binding and biological activity and together act synergistically in vitro. The Abs have been used successfully in primate models of allograft rejection, graft-vs-host disease, and autoimmunity. We produced bifunctional humanized anti-IL-2R alpha beta Abs (BF-IgG) to combine the specificity of the two Abs into one entity by fusing HAT-producing NSO cells and HuMik beta 1-producing Sp2/0 cells. BF-IgG was purified using protein G-Sepharose affinity chromatography, followed by IL-2R alpha and IL-2R beta affinity chromatography and hydrophobic interaction chromatography. BF-IgG exhibited both anti-IL-2R alpha and anti-IL-2R beta specificities in binding assays. While the Ab binds the IL-2R with intermediate affinity (Kd = 2.82 nM), it does not inhibit IL-15 binding to its high affinity IL-15R. In Kit225/K6 (IL-2R alpha beta gamma+) cells, BF-IgG was 10-fold more potent than a HAT/HuMik beta 1 equimolar mixture in blocking IL-2-induced proliferation and, unexpectedly, was at least 65-fold more active than the mixture in blocking IL-15-induced proliferation. This dual inhibitory activity may be due to cross-linking of the IL-2R alpha and IL-2R beta, thus blocking IL-2 binding and possibly impeding the association of IL-2R beta with IL-15R. BF-IgG has potent immunosuppressant activities against both IL-2- and IL-15-mediated responses, and this antagonist could be more efficacious than HAT and/or HuMik beta 1 for the treatment of autoimmunity and the prevention of allograft rejection.

Bispecific humanized anti-IL-2 receptor alpha beta antibodies inhibitory for both IL-2- and IL-15-mediated proliferation

Humanized anti-Tac (HAT) and Mik beta1 (HuMik beta 1) Abs directed at IL-2R alpha and IL-2R beta, respectively, inhibit IL-2 binding and biological activity and together act synergistically in vitro. The Abs have been used successfully in primate models of allograft rejection, graft-vs-host disease, and autoimmunity. We produced bifunctional humanized anti-IL-2R alpha beta Abs (BF-IgG) to combine the specificity of the two Abs into one entity by fusing HAT-producing NSO cells and HuMik beta 1-producing Sp2/0 cells. BF-IgG was purified using protein G-Sepharose affinity chromatography, followed by IL-2R alpha and IL-2R beta affinity chromatography and hydrophobic interaction chromatography. BF-IgG exhibited both anti-IL-2R alpha and anti-IL-2R beta specificities in binding assays. While the Ab binds the IL-2R with intermediate affinity (Kd = 2.82 nM), it does not inhibit IL-15 binding to its high affinity IL-15R. In Kit225/K6 (IL-2R alpha beta gamma+) cells, BF-IgG was 10-fold more potent than a HAT/HuMik beta 1 equimolar mixture in blocking IL-2-induced proliferation and, unexpectedly, was at least 65-fold more active than the mixture in blocking IL-15-induced proliferation. This dual inhibitory activity may be due to cross-linking of the IL-2R alpha and IL-2R beta, thus blocking IL-2 binding and possibly impeding the association of IL-2R beta with IL-15R. BF-IgG has potent immunosuppressant activities against both IL-2- and IL-15-mediated responses, and this antagonist could be more efficacious than HAT and/or HuMik beta 1 for the treatment of autoimmunity and the prevention of allograft rejection.

[Study on red cell enzymes and isoenzymes in patients with leukemia and myelodysplastic syndromes]

OBJECTIVE

To define the prevalence of acquired red cell enzymopathy in leukemia and MDS patients and explore its clinical significance.

METHODS

Red cell enzymes (G6PD, 6PGD, PK, ENOL, ADA, PNP,ALD) activities and PK,ADA isoenzymes were assayed by the methods recommended by ICSH and PAGE electrophoresis.

RESULTS

The prevalence rate of G6PD deficiency was 43.1%, and of PK deficiency was 27.8%, in leukemia and MDS patients. The prevalence rates of PK, G6PD and PNP deficiency in MDS patients were 50%, 48% and 39.1%, respectively, while of ADA, ENOL and ALD over production in MDS patients were 69. 6%, 40% and 30. 4%, respectively. PK activity was increased in CML, while the PK isoenzyme pattern was normal. Administration of antitumor antibiotics to AL decreased G6PD and 6PGD activities (P < 0.05). ADA2 was expressed in MNC of AML (M4 and M5) and in RBC of CMML, but not expressed in ALL (P < 0.001).

CONCLUSION

Determination of enzymes may be used as prognostic parameters in CML,a predictor of antitumor drug resistance in acute leukemia, and a differential parameter between MDS-RA and aplastic anemia and between CML and CMML.

Methylene-blue-sensitized dichromated gelatin holograms with antihumidity polymer coatings

An efficient method of resisting humidity for methylene-blue-sensitized dichromated gelatin (MBDCG) holograms is reported. The method uses a viscous liquid pure poly(styrene) solution with a low degree of polymerization as the coating material. On the basis of this coating, the diffraction efficiency of treated MBDCG holograms exposed to a high-humidity (relative humidity of 80-85%) environment was not obviously changed during observation over 3 mon.

Failure to activate interleukin 1beta-converting enzyme-like proteases and to cleave retinoblastoma protein in drug-resistant cells

We previously found that retinoblastoma (RB) is cleaved at the initiation of apoptotic execution. Here we report that when an HL-60 cell line resistant to cytosine arabinoside (Ara-C) was exposed to this anticancer drug, neither RB cleavage nor apoptosis was detected. Consistent with that, processing of interleukin 1beta-converting enzyme (ICE) and CPP32 (an ICE-like protease) was also prevented in these cells. In contrast, treatment of the HL-60-Ara-C-resistant cells with etoposide induced all of these apoptotic events. Furthermore, the etoposide-induced RB cleavage was inhibited by a specific tetrapeptide ICE-like inhibitor. Our results demonstrate that activation of the RB cleavage enzyme, an ICE-like protease, is required for overcoming drug resistance.

[Clinical study of the pattern of lymphnode metastasis in carcinoma of esophagus: an analysis of 200 cases]

To study the pattern of lymphnode metastasis in carcinoma of the esophagus, 200 cases of resected esophageal cancer specimens were carefully examined pathologically. Lymphnode metastasis, its pathway and extent in relation to pathological changes were analyzed. Lymphnode metastasis was mainly regional and extended vertically in both directions. Leaping-over metastasis was another feature. The deeper invasion by the tumor, the higher frequencies of metastasis development, and vice versa. However, leaping-over metastasis was more likely to occur where tumor invasion was less severe. Owing to the high frequency of lymphnode metastasis in the superior mediastinum and the widely spanned leaping-over metastases, an operative approach by three incisions through right thoracotomy with excision of the whole segment of esophagus and anastomosis at cervical region was recommended, in order to dissect lymphnodes in the cervical, thoracic and abdominal regions and to leave less or no metastatic lymphnodes behind.

Somatic histone H1 microinjected into fertilized mouse eggs is transported into the pronuclei but does not disrupt subsequent preimplantation development

We injected somatic subtypes of histone H1 into newly fertilized mouse eggs, which do not naturally contain this chromosomal protein, and examined the fate of the injected protein and its effect on preimplantation development of recipient eggs. Rhodamine-labelled H1 injected into the cytoplasm of 53 eggs was transported into the pronuclei in 51 cases, and this nuclear accumulation could be detected within 15 min of injection. Unlabelled histone H1, which was detected using immunofluorescence, was also transported following microinjection to the pronuclei, where it colocalized with the chromatin and remained associated with the nuclei following cleavage to the two-cell stage. Nuclear accumulation of injected H1 was inhibited when injected eggs were incubated in the presence of drugs that prevent mitochondrial electron transport or glycolysis, which indicates that nuclear transport occurs through an energy-dependent process, as previously observed in tissue culture cells. To determine whether the presence of somatic H1 in early embryonic nuclei would influence subsequent development, fertilized eggs were injected with an approximately physiological quantity (1-5 pg) of somatic H1 or, as controls, with another small basic protein, cytochrome c. Fifty-three eggs were injected with cytochrome c, of which 51 divided to the two-cell stage, and 32 (60%) reached the blastocyst stage, after 5 days in culture. One hundred and eleven eggs were injected with somatic H1, of which 95 divided to the two-cell stage, and 53 (48%) reached the blastocyst stage, after 5 days in culture. The two groups did not differ statistically (chi 2, P > 0.1) with respect to the fraction of injected embryos that developed to the blastocyst stage. These results show that, although mouse embryos lack the somatic subtypes of histone H1 until the four-cell stage of development, they are able to progress through preimplantation development when these subtypes are present beginning at the one-cell stage. This may imply that the distinctive chromatin composition that characterizes early embryos of a variety of species is not essential for early development in mammals.

[The influence on prognosis of intraoperative chemotherapy for adenocarcinoma of gastric cardia]

Four hundred and four patients underwent surgical treatment for adenocarcinoma of the gastric cardia in our hospital between January 1980 to June 1990. Of 342 resected cases, 231 cases were treated with surgery alone, their 1-, 3-, and 5-year survival rates were 83.8%, 38.5% and 20.8%, respectively. Since January 1987, postoperative chemotherapy was given in 47 patients, their 1-, 3-, and 5-year survival rates were 89.4%, 46.8%, 29.8%, respectively, while intraoperative chemotherapy in 54 cases, had 1-, 3-, and 5-year survival rates of 87.1%, 63.0% and 38.9%, respectively. The result showed that the 3- and 5-year survival rates were higher in postoperative chemotherapy cases than in cases with operation alone, but there was no statistical significance between the two groups. However, intraoperative chemotherapy group had much higher 3- and 5-year survival rates than operation alone (P < 0.01). Intra-operative chemotherapy is recommended especially in patients beyond stage I with lymph node metastasis.

Formation of interstrand DNA cross-links by bis-(2-chloroethyl)sulfide (BCES): a possible cytotoxic mechanism in rat keratinocytes

Interstrand cross-links in the DNA of epidermal basal keratinocytes may be responsible for cell death and consequent vesication in skin exposed to BCES. The formation of cross-links and cytotoxicity were compared when cells in primary monolayer cultures of rat epidermal keratinocytes, synchronized at the G1/S boundary or in the G1 phase of the cell cycle, were exposed to BCES. The dose-responsive formation of cross-links, measured with an ethidium bromide-fluorescence assay, was determined immediately after exposure of cells at either position of the cycle. At 24 hr post-exposure, the level of cross-links in cells exposed at the G1 phase showed had not decreased significantly and was still dose-dependent. However, cells exposed in the G1 phase showed a major decrease in cross-links. Formation of interstrand DNA cross-links appears to be related to the mustard's cytotoxicity.

GABAA receptors modulate early spontaneous excitatory activity in differentiating P19 neurons

P19 embryonic carcinoma (EC) stem cells are pluripotent and are efficiently induced to differentiate into neurons and glia with retinoic acid (RA) treatment. Within 5 days, a substantial number of differentiating P19 cells express gene products that are characteristic of a neuronal phenotype. P19 neurons were used as a model to explore the relationship between neuronal "differentiation" in vitro and the acquisition of gamma-aminobutyric acid (GABAA) receptors and functional GABA responses. Pulse-labeling experiments using bromodeoxyuridine indicated that all neurons had become postmitotic within 3-4 days after treatment with RA. This was confirmed by a reduction in the immunocytochemical detection of the undifferentiated stem cell antigen SSEA-1. Subsequently, a transient expression of nestin was observed during the first 5 days in vitro (DIV) after exposure to RA. By 5-10 DIV after RA, a significant number of neurons (approximately 80-90%) expressed immunocytochemically detectable glutamate decarboxylase and GABA coincident with the acquisition of membrane binding sites for tetanus toxin. These phenotypic markers were maintained for > 30 DIV after RA. Under current-clamp conditions, random, low-amplitude, spontaneous electrical activity appeared in neurons within the first few days after RA treatment and this was blocked by the specific GABAA receptor antagonist bicuculline. Thereafter, the appearance and progressive increases in the frequency of spontaneous action potentials in P19 neurons were observed that were similarly attenuated by bicuculline. In neurons > 5 DIV after RA, exogenous application of GABA elicited similar action potentials. The onset of excitatory responses to GABA or muscimol in voltage-clamped neurons appeared immediately after the cessation of neuronal mitosis and before the previously reported acquisition of responses to glutamate. In fura-2 imaging studies, the exogenous application of GABA resulted in neuron-specific increases in intracellular Ca2+. Thus, P19 neurons provide an in vitro model for the study of the early acquisition and properties of electrical excitability to GABA and the expression of functional GABAA receptors.

Appearance of interleukin 1 alpha relates DNA interstrand cross-links and cytotoxicity in cultured human keratinocytes exposed to bis-(2-chloroethyl) sulfide

The utility of an increase in the level of interleukin 1 alpha (IL-1 alpha) as an indicator of cytotoxicity from exposure to bis-(2-chloroethyl) sulfide (BCES) was evaluated in submerged monolayer cultures of human cutaneous keratinocytes. Four-day-old cultures were exposed to 1-100 microM BCES at 37 degrees for 30 min. The amounts of IL-1 alpha in the medium at and in cells 72 h after exposure were measured immunologically with an enzyme-linked immunosorbent assay using monoclonal antibody to human IL-1 alpha. The antibody was conjugated with peroxidase for visualization. Cell viability was measured concomitantly using the trypan blue exclusion technique. The degree of interstrand cross-linking as a measure of damage in the cellular DNA was determined by measuring the fluorescence resulting from the intercalation of ethidium bromide into double-stranded molecules that remained in heat-denatured DNA isolated from cells that had been exposed to BCES. A high correlation was observed between the dose-responsive increase in the level of IL-1 alpha in the medium and in the cells, and the dose-responsive decrease that took place in the fraction of viable cells in exposed cultures. The dose-responsive increase in the interstrand cross-linking found in the DNA of cells immediately after exposure to BCES also correlated with the increase in IL-1 alpha 72 h after exposure. These data suggest that the appearance of IL-1 alpha can be used to quantify the cytotoxicity resulting from BCES-medicated damage to cellular DNA and that degree of cross-linking in the DNA immediately after exposure to BCES is predictive of the level of cytotoxicity in an exposed culture 3 days later.

De-O-ethylsalvonitin and salprionin, two further diterpenoids from Salvia prionitis

From Salvia prionitis two new diterpenoids, de-O-ethylsalvonitin and salprionin, were isolated, and their structures and NMR data were assigned by spectral analysis and computer modelling calculations.