[Changes of blood circulation, muscle and skeletal systems in 30 d tail-suspended [correction of tail-suspented] rats]

OBJECTIVE

To confirm the tail-suspended rat model for the study of countermeasures against weightlessness.

METHOD

The changes of blood circulation, muscle and skeletal systems in control group rats (n = 15) and 30 d tail-suspended rats (n = 15) were compared.

RESULT

Compared with the control group, the hemorrheology and erythrocyte deformability decreased significantly, muscle-fiber atrophy, muscle contraction function decreased, the type I muscle fibers transformed to the type II muscle fibers, bone-mineral content of L3 and load capacity of femur declined, bone metabolism changed in the suspended rats.

CONCLUSION

The tail-suspended rat is a suitable animal model for the study of countermeasures against weightlessness.

Novel method for isolation of adult porcine pancreatic islets with two-stage digestion procedure

It is particularly difficult to isolate porcine islets (PI). Experience suggests that the success rate of porcine islet isolation (PII) is probably considerably influenced by the distension and digestion of the pancreas. In this study, we divided the digestion procedure into two stages and developed a new enzyme solution to improve both the distension and digestion procedures. As a result, we established a novel and stable method of large-scale adult porcine islet isolation (APII). The harvested pancreata of 2-year-old pigs weighing over 200 kg (n = 18) were distended by introducing our new enzyme solution gently and slowly through the pancreatic ducts. Two-stage digestion (cold, then warm) was then performed by first placing the distended pancreata on ice for 2 h to cause diffusion of the enzyme solution around the islets, and then by incubating the pancreata in a water bath at 37 degrees C for 45 min without shaking. The islets were purified by a COBE 2991 cell processor on dextran T70 discontinuous density gradients. Histological study was performed on porcine pancreata sampled after 0, 15, 30, and 45 min of the second stage, and stained with H&E stain. Next, islet equivalent was calculated. Static incubation study was performed by stimulating the islets with 3.3 and 16.7 mM glucose in Krebs' Ringer bicarbonate buffer (KRBB) solution at 37 degrees C for 1 h, and finally the insulin released was measured. The dilated acinar cells septa around the islets were observed at time 0. Destruction of the acinar cells around the islets by warm digestion was recognized at 15 and 30 min, and destroyed and separated acinar cells present around the islets at 45 min. During the entire course of the warm digestion, the islets remained intact. The number of isolated islets was 291,667 +/- 240,452 IEQ/pancreas (n = 14) and 3,294 +/- 2199 IEQ/g of pancreatic tissue. The purity of recovered porcine islets was over 90%. The concentration of the insulin secreted by 10,000 IEQ islets selected at random was 83.9 +/- 13.4 microU/dish/h in response to 3.3 mM glucose and 104.1 +/- 12.9 microU/dish/h in response to 16.7 mM glucose (n = 20). A success rate of approximately 80% was attained with APII. We demonstrated that this increase in the success rate was due to the improved distension and digestion provided by this method. This two-stage APII method with its new enzyme solution may facilitate the future use of porcine islets in clinical xenotransplantation trials.

[The Raman spectra of rubidium titanyl arsenate]

The Raman spectra of rubidium titanyl arsenate (RTA) single crystal with different geometric arrangements were obtained and compared with those of rubidium titanyl phosphate (RTP), potassium titanyl arsenate (KTA) and potassium titanyl phosphate (KTP) single crystals. The assignments of various vibration modes were made according to the experimental results. The strong Raman scattering intensity implies that RTA crystal possesses large nonlinear optical property and the strongest scattering is from the TiO6 octahedron. From the mode splitting of AsO4 tetrahedron, we conclude that the distortion of AsO4 in RTA is larger than that of PO4 in KTP.

No metal cofactor in orotidine 5'-monophosphate decarboxylase

Orotidine 5'-monophosphate decarboxylase (OMP decarboxylase, ODCase) is an important enzyme that catalyzes the final step of de novo pyrimidine nucleotide biosynthesis. The mechanism of this unique enzyme and whether metal ions play any role in catalysis have been topics of intense research interest. In this report, the role of Zn in ODCase was reexamined. Atomic absorption (AA) and X-ray absorption (XAS) spectroscopic studies did not detect zinc in active enzyme samples at high concentration. The XAS results also indicated the absence of other transition metal ions in ODCase.

Cisplatin-induced activation of mitogen-activated protein kinases in ovarian carcinoma cells: inhibition of extracellular signal-regulated kinase activity increases sensitivity to cisplatin

Cisplatin treatment activates multiple signal transduction pathways, which can lead to several cellular responses including cell cycle arrest, DNA repair, survival, or apoptosis. We investigated the response of the mitogen-activated protein kinases, extracellular signal-regulated kinases 1 and 2 (ERK1/2), c-Jun-N-terminal kinase 1 (JNK1), and p38, to cisplatin treatment in the ovarian carcinoma cell line SK-OV-3. Cisplatin caused a late and prolonged induction in a dose-dependent manner of both ERK1/2 and JNK1 activity. ERK1/2 and JNK1 activities continued to increase in magnitude up to 24 h following initiation of cisplatin treatment. In contrast, cisplatin treatment had no effect on p38 activity. Transplatin failed to induce either ERK1/2 or JNK1 at 24 h, which suggests that the activation of these kinases was dependent on cisplatin-specific DNA damage. Treatment with cycloheximide resulted in inhibition of cisplatin-induced ERK1/2 activation, demonstrating that ERK1/2 activity induced by cisplatin was dependent on de novo protein synthesis. Furthermore, inhibition of cisplatin-induced ERK1/2 activity by PD 98059 caused enhanced cisplatin cytotoxicity. Similar enhanced cytotoxic effects of cisplatin were also observed following treatment with PD 98059 in the ovarian carcinoma cell line UCI 101. These observations indicate that ERK1/2 activation induced by cisplatin partially protects cells from cisplatin cytotoxicity. Continued investigation into the mechanism by which the ERK pathway and other signal transduction pathways modulate the response to cisplatin may be helpful in the development of new strategies for improving the therapeutic use of platinum drugs.

[Serum levels of soluble intercellular adhesion molecule 1 in malignant lymphoproliferative disorders]

OBJECTIVE

To investigate the correlation of serum levels of soluble intercellular adhesion molecule 1 (sICAM-1) with clinical situation and treatment outcome in lymphoproliferative disorders.

METHODS

Serum sICAM-1 levels were measured by immunoenzymatic assay.

RESULTS

Pre-treatment serum sICAM-1 levels were above normal in 41% (9/22) of multiple myeloma (MM), 53% (17/32) of non-Hodgkin's lymphoma (NHL) and 63% (12/19) of acute lymphocytic leukemia (ALL) patients. Serum sICAM-1 levels in MM were positively correlated with Bataille stages, but were not related to Durie stage. Meanwhile, sICAM-1 levels in NHL were associated with the category of pathology, Ann Arbor stage and B symptom, but were not related to serum LDH levels. sICAM-1 levels were significantly higher in ALL patients complicated with central nervous system leukemia (CNSL) than in those without CNSL. Patients with elevated serum sICAM-1 levels had poorer treatment outcomes. Serum sICAM-1 levels were returned to normal at remission.

CONCLUSION

Measurement of serum sICAM-1 levels in lymphoproliferative disorders patients is helpful for judging the clinical status and treatment outcome.

Nitroreductase-mediated cell ablation is very rapid and mediated by a p53-independent apoptotic pathway

Nitroreductase (NTR)-mediated selective cell ablation using the prodrug CB1954 has been achieved in vivo by targeting the nitroreductase gene to the luminal cells of the mammary gland in transgenic mice. We report that the cell ablation occurs very rapidly, starting as early as 7 h after administration of the prodrug. By cross-breeding the BLG-NTR transgenic mice to a p53-deficient mouse strain, we have generated BLG-NTR transgenic mice on a p53 null background and tested NTR-mediated cell ablation in these mice. The transgenic mice lacking a functional p53 gene showed cell ablation at a similar level compared with p53 wild-type transgenic mice, showing that functional p53 is not required for CB1954-NTR mediated cell death. These results provide further support for using this system in anti-cancer therapy.

A novel follicle-cell-dependent dominant female sterile allele, StarKojak, alters receptor tyrosine kinase signaling in Drosophila

We describe a new dominant allele, StarKojak, that alters receptor tyrosine kinase signaling in the follicle cells and in the eyes in Drosophila. We isolated StarKojak in a screen for follicle-cell-dependent dominant female sterile mutations. We show that StarKojak and revertants of StarKojak do not complement Star loss-of-function mutations. We propose that StarKojak is a novel type of allele of Star that has both dominant gain-of-function phenotypes early in development and dominant loss-of-function phenotypes later in development. Star encodes a putative transmembrane protein that has previously been shown to be a critical component of the epidermal growth factor receptor tyrosine kinase signaling pathway. Early in oogenesis, Star mRNA expression is higher in StarKojak egg chambers than in wild-type egg chambers, consistent with its gain-of-function phenotype. Later in oogenesis, Star mRNA expression is lower in StarKojak follicle cells than in wild-type follicle cells, consistent with its loss-of-function phenotype. By genetically analyzing StarKojak and its revertants, we present evidence that Star is involved in anterior-posterior axis formation both in the female germline cells and in the somatic follicle cells. We also demonstrate that at least part of the dominant female sterile phenotype of StarKojak is restricted to the posterior-pole follicle cells. We propose that Star functions by processing pro-Gurken to mature Gurken, which is thereby released in the region between the oocyte and the follicle cells and binds to the epidermal growth factor receptor in the follicle cells.

Treatment of hepatitis caused by cytomegalovirus with allitridin injection--an experimental study

To demonstrate the anti-cytomegalovirus (CMV) activity of allitridin injection (AI), an active anti-infection component of garlic, the in vitro effects of AI on human CMV (HCMV) AD169 and 7 newly isolated strains from patients and its in vivo effect on mice of murine CMV (MCMV) hepatitis were assessed. It was found that plaque reduction rate reached 63.5% after infected cells were treated with cell maximal tolerable concentration (7.5 micrograms/ml) of AI. Meanwhile, flow cytometric analysis for effect of AI on expression of HCMV immediate-early antigen (IEA) showed that IEA inhibition rate of 7 isolated strains was in the range from 43.3% to 66.7%, with a mean of 58.4%, similar to that of AD169 strain (60.5%). On the other hand, in vivo anti-CMV activity of AI was evaluated in terms of liver pathological changes, liver function and viral replication. Six model mice with MCMV hepatitis received the treatment of AI for 2 weeks. The severity of liver damage, levels of sALT and MCMV IE genes expression in liver tissues in the treated mice were significantly lower than those of the corresponding untreated controls. Our results showed that AI had an obvious anti-CMV activity both in vitro and in vivo.

Enrichment of presenilin 1 peptides in neuronal large dense-core and somatodendritic clathrin-coated vesicles

Presenilin 1 is an integral membrane protein specifically cleaved to yield an N-terminal and a C-terminal fragment, both membrane-associated. More than 40 presenilin 1 mutations have been linked to early-onset familial Alzheimer disease, although the mechanism by which these mutations induce the Alzheimer disease neuropathology is not clear. Presenilin 1 is expressed predominantly in neurons, suggesting that the familial Alzheimer disease mutants may compromise or change the neuronal function (s) of the wild-type protein. To elucidate the function of this protein, we studied its expression in neuronal vesicular systems using as models the chromaffin granules of the neuroendocrine chromaffin cells and the major categories of brain neuronal vesicles, including the small clear-core synaptic vesicles, the large dense-core vesicles, and the somatodendritic and nerve terminal clathrin-coated vesicles. Both the N- and C-terminal presenilin 1 proteolytic fragments were greatly enriched in chromaffin granule and neuronal large dense-core vesicle membranes, indicating that these fragments are targeted to these vesicles and may regulate the large dense-core vesicle-mediated secretion of neuropeptides and neurotransmitters at synaptic sites. The presenilin 1 fragments were also enriched in the somatodendritic clathrin-coated vesicle membranes, suggesting that they are targeted to the somatodendritic membrane, where they may regulate constitutive secretion and endocytosis. In contrast, these fragments were not enriched in the small clear-core synaptic vesicle or in the nerve terminal clathrin-coated vesicle membranes. Taken together, our data indicate that presenilin 1 proteolytic fragments are targeted to specific populations of neuronal vesicles where they may regulate vesicular function. Although full-length presenilin 1 was present in crude homogenates, it was not detected in any of the vesicles studied, indicating that, unlike the presenilin fragments, full-length protein may not have a vesicular function.

Fine particulate organic material in the Los Angeles Basin-I: assessment of the high-volume Brigham Young University organic sampling system, BIG BOSS

A multi-system, high-volume, parallel plate diffusion denuder Brigham Young University Organic Sampling System (BIG BOSS) was tested using collocated samplers at the Pico Rivera Monitoring Station of the South Coast Air Quality Management District, South Coast Air Basin, in September 1994. Six-hr daytime and 9-hr nighttime samples were collected with a flow of about 200 L/min through each of the three systems designed to collect particles smaller than 2.5, 0.8, and 0.4 microns in a diffusion denuder sampler. Efficiency for the removal of gas phase organic compounds by the diffusion denuder was evaluated using both theoretical predictions and field measurements. Both measured and calculated data indicate high denuder efficiency for the removal of gas phase aromatic and paraffinic compounds. The precision of the BIG BOSS was evaluated using collocated samplers. The precision of determination of total carbon and elemental carbon retained by a quartz filter or of semi-volatile carbonaceous material lost from particles during sampling averaged +/- 7%. The precision of determination of individual organic compounds averaged +/- 10%. An average of 42 and 62% of the particulate organic material was semi-volatile organic compounds (SVOCs) lost from particles during sampling for daytime and nighttime samples, respectively. This "negative" sampling artifact was an order of magnitude larger than the "positive" quartz filter artifact due to adsorption of gas phase organic material. Daytime concentrations of fine particulate elemental carbon and nonvolatile organic carbon were higher than nighttime concentrations, but nighttime fine particles contained more semi-volatile organic material than daytime.

Effect of a new immunosuppressive agent, FTY720, on survival of islet allografts

A newly developed immunosuppressant, FTY720, has a unique mechanism that is quite different from those of conventional immunosuppressants, and is presumed to be mediated through decreases in the number of peripheral lymphocytes, especially helper T cells. This study was performed to ascertain whether this innovative drug could prolong islet allograft survival. The donors were inbred Lewis rats and the recipients were ACI rats rendered hyperglycemic with intravenous streptozotocin. In the study group, FTY720 dissolved in distilled water was orally administered at a dose of 5 mg/kg to the recipient ACI rats 1 day before and on the day of grafting. In the control group, only distilled water was orally administered to the recipient ACI rats on the day before and the day of grafting. Two thousand islets were transplanted into the portal vein of the recipient rats in the study and control groups immediately after isolation. The graft survival time in the study group was significantly longer than that in the control group, indicating that FTY720 retains a potent effect on the prolongation of islet allograft survival. FTY720 could become a useful immunosuppressant for future clinical islet allotransplantation.

[Changes of bone cytokines and compensating regulation in tail suspended rats]

The aim of the study was to determine the relationship between the changes in bone metabolism and insulin-like growth factor--I(IGF-I) as well as epidermal growth factor (EGF). 10 Male S.D. rats were tail-suspended for 28 d with another 10 free active rats as control. The results showed that mineral content increased significantly, osteocalcin and albumin content had no significant change, but IGF-I and EGF content increased significantly in L3 in the suspended rats. The results suggest that although there are no change in osteocalcin and albumin content, the phenomenon of bone mineral loss still exists in the suspended rats. The increase in IGF-I and EGF content may be one of the compensation responses of the bone in the suspended rats.

Improved large-scale isolation of breeder porcine islets: possibility of harvesting from nonheart-beating donor

To establish a large-scale isolation procedure for adult porcine islets usable as a donor source for xenotransplantation and as a model of human islet isolation, we improved several characteristics of the conventional isolation procedure. At a slaughterhouse we first selected a breeder pig over 1.5 years old (and over 200 kg in weight) with warm ischemic time (WIT) of 15 +/- 2 minutes as nonheart-beating donors. Then, we made a special enzymic mixture that consisted of collagenase S-1 (260 U/mg, NittaZelatin, Japan), collagenase P (1.86 U/ml Lyo Boehringer-Mannheim, USA), DNase (Sigma, St. Louis, Mo), Disparse (NittaZelatin, Japan), and protease inhibitor (Sigma). Third, this mixture was injected very gently into the pancreatic duct at the time of pancreatic harvesting. To prevent overdigestion of the pancreas, the mixture was first cooled to less than 10 degrees C. Fourth, during the warm digestion of pancreas, the pancreas with the enzymic mixture was quietly put in a water bath at 37 degrees C without mechanical shaking. Fifth, we purified the islets with a COBE 2991 cell processor by the Dextran 70 gradient method, because Dextran 70 is very cheap and has the same purification effect as the Ficoll gradient. The results of 10 consecutive breeder porcine islet isolations are reported. The total yield of isolations of islets over 50 microm in the longest diameter after staining with Dithizone (DTZ) was 85,900 +/- 19,954 islets, 291,667 +/- 240,452 IEQ (2,900 +/- 2,324 IEQ/g). The purity of the isolated islets was very high: 90.2 +/- 3.8%. Glucose stimulation during in vitro incubation induced significant insulin release from isolated breeder porcine islets. In two of the diabetic rats receiving encapsulated islets grafts using a mesh-reinforced polyvinyl alcohol hydrogel bag (MRPB), a prominent reduction in serum glucose levels (less than 200 mg/dL) persisted for 13 and 19 days, respectively, after intraperitoneal xenotransplantation islets without immunosuppression. In conclusion, we succeeded in a more efficient and less-expensive isolation of a large amount of adult porcine islets from a nonheart-beating donor.

Transforming growth factor beta is essential for spindle cell conversion of mouse skin carcinoma in vivo: implications for tumor invasion

Transforming growth factor beta1 (TGF-beta1) regulates both cell growth and cellular plasticity and is therefore important in the molecular control of both the developmental and neoplastic processes. It has been suggested that TGF-beta1 may be a positive or negative regulator of tumorigenesis. Stimulation of tumorigenesis could be due to its action as an immunosuppressor or as an inducer of angiogenesis, or by its direct action on the cell in promoting cellular plasticity. In the current study, we provide evidence that TGF-beta1 can act directly on keratinocytes in vivo to induce the reversible epithelial-mesenchymal conversion of a malignant metastatic keratinocyte cell line. Two squamous clones from the cell line were shown to undergo a reversible conversion to a fibroblastoid phenotype after culture in 1 ng/ml TGF-beta1. The morphological conversion became apparent at 24 h post-TGF-beta treatment and was complete after another 24 h. The conversion was characterized by a rapid delocalization of E-cadherin within 6-12 h posttreatment, followed by down-regulation of E-cadherin levels by 72 h. These squamous clones spontaneously converted to a fibroblastoid phenotype after s.c. injection in nude mice. Importantly, four of four clones that had been stably transfected with a dominant negative TGF-beta type II receptor were unable to undergo this mesenchymal switch in vivo, despite the fact that all clones stably transfected with neomyocin resistance alone retained their spindle characteristics in vivo. This demonstrates that the epithelial-mesenchymal conversion event is mediated directly via the TGF-beta signaling pathway of the tumor cell per se, and that it is sufficient to significantly enhance tumorigenicity and the malignant and invasive characteristics of the tumor in vivo.

Detection and identification of enteroviruses RNA by using polymerase chain reaction

For rapid diagnosis of enteroviral infection in clinic practice, we developed a reverse transcription and polymerase chain reaction (RT-PCR) assay. Primers homologous to the conserved 5' non-coding region were designed by analyzing enteroviral genomes, and then they were used to enzymatically amplify RNA from 31 prototype enteroviral strains and enteroviruses (EV) in cerebrospinal fluid (CSF) of 34 cases of aseptic meningitis and 11 cases of aseptic encephalitis. The RT-PCR products generated with these enteroviral primers were analyzed by agar gel electrophoresis and dot blot hybridization analysis. 31 EV strains showed an obvious monoclonal amplification band, and all dot blot hybridization results were positive. Four other viruses and cells cultured were all negative. The study of sensitivity of the RT-PCR showed that amplification production were positive to 10(-2)-10(-3) 50% tissue culture infective doses. With this assay, 21 (61.8%) of 34 aseptic meningitis and 8 (72.7%) of 11 aseptic encephalitis contained EV RNA in CSF samples. Two cases of meningitis and one of encephalitis with EV infection were still positive during convalescence. Our results suggest that this RT-PCR method was a fast, sensitive and specific technique for detection of common EV infection.

Tumor necrosis factor alpha, interleukin-6, interleukin-8, and interferon alpha in children with viral hepatitis

To investigate the cellular immunological changes in children with viral hepatitis, interleukin 6 (IL-6), interleukin 8 (IL-8), interferon alpha (IFN alpha), and tumor necrosis factor alpha (TNF alpha) in supernatant of cultured peripheral blood mononuclear cells (PBMCs) of 49 children with hepatitis A, B or C were measured. The levels of IL-6, IL-8, TNF alpha in PBMCs of the 3 viral hepatitis groups were increased and the level of IFN alpha decreased as compared with those of normal control group. But there were no significant differences among the 3 viral hepatitis groups. It was concluded that cellular immunological disorders were related to the onset and the induced damage of the viral hepatitis in children.

Changes in bone noncollagenous proteins and bone mineral loss in lumbar vertebrae of tail-suspended rats

The purpose of the study is to clarify whether the noncollagenous proteins play a role in bone mineral loss and whether the quality of osteocalcin (OC) is deteriorated in simulated weightlessness. Noncollagenous proteins, such as OC and albumin, have been shown to be effective in promoting bone mineralization. In this study, the contents of OC, albumin, and mineral in the third lumbar vertebra (L3) were determined in rats suspended by tail for 21 days. The concentration of serum-immunoreactive osteocalcin (irOC) were also measured before and after adsorption to hydroxylapatite. The results showed that the contents of mineral, osteocalcin, and albumin in L3 were significantly decreased in suspended rats. The concentration of serum irOC and serum irOC with a high affinity to hydroxylapatite (irOCbound) were significantly decreased, but the low affinity (irOCfree) remained unaffected. The data suggest that the mineral loss in L3 of suspended rats is related to the decreased contents of osteocalcin, and albumin in bone mass. The incomplete gamma-carboxylation of osteocalcin in suspended rats is also one of the important causes of bone loss.

A Drosophila kinesin-like protein, Klp38B, functions during meiosis, mitosis, and segmentation

We show that klp38B, isolated as a mutation that dominantly prolongs blastoderm mitotic cycles in Drosophila, encodes a Drosophila kinesin-like protein. Further genetic analyses show that Klp38B not only functions during mitosis, but is also required for meiosis and abdominal segmentation. Sequence comparisons suggest that Klp38B encodes an amino-terminal microtubule motor domain, a central alpha-helical coiled-coil domain, and a C-terminal globular domain. Evidence that Klp38B is required during meiosis is that flies transheterozygous for mutations in both klp38B and nod have a high frequency of 4th chromosome meiotic nondisjunction. Nod is a chromokinesin, a chromosome binding kinesin, that is believed to provide astral-exclusion forces during the metaphase stage of meiosis. Evidence that Klp38B is required during mitosis is that embryos from female germline clones of klp38B mutations have holes in the cuticle similar to a zygotic string (dCDC25) phenotype. Also, anti-Klp38B antibody injection into precellularization blastoderm embryos causes developmental arrest and the formation of circular mitotic figures. We speculate, based on these phenotypes, that Klp38B is a chromokinesin that provides astral-exclusion forces on the chromosomes during meiosis and mitosis. Consistent with this hypothesis, we have identified an HMG-1 homologous region on Klp38B that could potentially bind AT-rich DNA sequences. Finally, we show that klp38B mutations have defects in abdominal segmentation, suggesting that Klp38B, like Xenopus chromokinesin Xklp1, might be involved in polar granule formation.

[Study on serum soluble interleukin-6 receptor levels in patients with malignant hematological diseases]

OBJECTIVE

To explore the clinical implication of soluble interleukin-6 receptor(sIL-6R) in patients with malignant hematological diseases.

METHODS

Serum levels of sIL-6R in 26 multiple myeloma (MM), 34 acute leukemia (AL) and 17 non-Hodgkin's lymphoma (NHL) patients before and after chemotherapy and 20 normal controls were measured by immunoenzymetic assay.

RESULTS

Serum levels of sIL-6R in MM and B-ALL patients at diagnosis were significantly higher than that in normal controls (P < 0.001, and P < 0.01, respectively), while the levels in ANLL, T-ALL and NHL patients were normal. Serum beta2 microglobulin and creatinine levels in MM patients with elevated serum sIL-6R were higher than that in patients with normal sIL-6R levels(P < 0.001, and P < 0.05, respectively). Serum sIL-6R levels did not relate to clinical stages. Serum lactic-dehydrogenase (LDH) levels in B-ALL patients with elevated sIL-6R were higher than that in patients with normal sIL-6R levels (P < 0.05). Serial measurement of serum sIL-6R in MM patients showed a good correlation with serum M-protein and plasma cell percentage in bone marrow.

CONCLUSION

Serum sIL-6R levels were significantly increased in MM and B-ALL patients, and it is a predictive factor for responsiveness to chemotherapy and an indicator of disease activity.

[Differential expression and response of growth factors in metastatic variants of human pulmonary giant cell carcinoma cell line]

OBJECTIVE

To study the difference in expression and response of certain growth factors between the two metastatic variants PGbE1 and PGLH7 of human pulmonary giant cell carcinoma, and the action of these growth factors on the metastasis of tumor cells.

METHODS

RT-PCT was conducted to detect the expression of TGF alpha, TGF beta 1, IL-6, IL-8, bFGF and ANG, and the expression of receptors EGFR, IL-6R and IL-8R; 3H-TdR incorporation assay was used to determine the effects of recombinant TGF alpha, TGF beta 1 and IL-6 on the proliferation of the two cells.

RESULTS

TGF alpha, EGFR, IL-6 and IL-6R were expressed at a higher level in PGbE1 cells than in PGLH7 cells. No significant differences were found in the expression of TGF beta 1, bFGF, IL-8, IL-8R and ANG between the two cells. Recombinant TGF alpha and IL-6 stimulated the proliferation of both cells, while TGF beta 1 had dual effects.

CONCLUSION

TGF alpha, TGF beta 1, bFGF, IL-6, IL-8 and ANG may be involved in the autocrine regulation of the growth and proliferation of pulmonary giant cell carcinoma, TGF alpha and IL-6 may play an important role in the metastasis of the tumor cells.

Selective cell ablation in transgenic mice expression E. coli nitroreductase

The gene encoding E. coli nitroreductase (NTR) was expressed in the luminal cells of the mammary gland of transgenic mice using the ovine beta-lactoglobulin promoter. Treatment of NTR expressing animals with the prodrug CB1954 (5-aziridin-1-yl-2-4-dinitrobenzamide) resulted in a rapid and selective killing of this population of cells whereas the closely associated myoepithelial cells were unaffected. NTR-mediated inducible cell ablation offers a number of advantages over the use of HSV1-tk for the selective killing of cells in vivo.

[Comparison of changes of bone mass, parathyroid hormone and calcitonin between two animal models of bone loss]

The changes in bone mass, blood parathyroid hormone (PTH) and calcitonin (CT) between rats suspended for 14 and 21 days, simulated weightlessness, and rats ovariectomized (OVX) for 30 and 60 days were observed. The results revealed that mineral density of T6 and L3 was significantly increased in rats suspended for 14 days. T6 mineral density was also significantly increased in rats suspended for 21 days, but L3 mineral density was significantly decreased. T6 mineral density had no change in OVX rats, but L3 mineral density was significantly decreased in them both for 30 and 60 days. Mineral content at proximal 1/3 of femur shaft was significantly decreased in rats suspended for 14 and 21 days, and in rats OVX for 60 days. Bone biomechanical properties of suspended rats were more seriously deteriorated than that in OVX rats. There was no change in blood PTH, but CT was significantly increased in rats suspended for 14 and 21 days. Blood PTH and CT were significantly decreased in rats OVX for 30 and 60 days. The results indicate that the mineral redistribution and bone loss are presented in trabecular bone of suspended rats, but not in OVX rats. The deterioration of bone quality was more seriously in suspended rats than that in OVX rats. Both the cortical and trabecular bone in the two models were affected.

[Effects of repeated nicotine uptake on brain inositol levels]

In the acute experiments, 30 minutes after nicotine was intraperitoneally injected at the doses of 0.5, 1.0, 1.0, 2.0, 2.0 mg/kg with 5 min interval, the inositol levels were increased in rats cerebral cortex and hippocampus rather than striatum. While the inositol level was decreased in rat cerebral cortex 30 minutes after lithium chloride was given at the dose of 10 mmol/kg. In the chronic experiments, after nicotine at the doses of 2.0-5.0 mg/kg was subcutaneouly injected twice a day for 14 days the inositol level was increased in rat cerebral cortex. In other experiments, nicotine was orally given at the dosese of 2.69, 6.26, 11.53 mg/kg.d for 64 days, the inositol level of rat cerebral cortex was also increased. These indicated that the effects of nicotine on inositol level of rat brain are different from those of lithium chloride, the inositol level of rat cerebral cortex can be increased by repeated administration of nicotine.

Modeling the G-protein-coupled neuropeptide Y Y1 receptor agonist and antagonist binding sites

Neuropeptide Y (NPY) receptors belong to the G-protein-coupled receptor (GPCR) superfamily and mediate several physiological responses, such as blood pressure, food intake, sedation and memory retention. To understand the interactions between the NPY Y1 receptor subtype and its ligands, computer modeling was applied to the natural peptide agonist, NPY and a small molecule antagonist, BIBP3226. An agonist and antagonist binding domain was elucidated using mutagenesis data for the Y1 receptor as well as for other GPCR families. The agonist and antagonist ligands which were investigated appear to share common residues for their interaction within the transmembrane regions of the Y1 receptor structure, including Gln120, Asn283 and His306. This is in contrast to findings with tachykinin receptors where the binding domains of the non-peptide antagonists have very little in common with the binding domains of the agonist, substance-P. In addition, a hydrogen bond between the hydroxyl group of Tyr36 of NPY and the side chain of Gln219, an interaction that is absent in the model complex between Y1 and the antagonist BIBP3226, is proposed as one of the potential interactions necessary for receptor activation.

Integrated regulation in response to simulated weightlessness

To investigate physiological effects of tail suspension, Ca2+ concentration, immune factors, erythrocyte rheological properties, and growth hormone were determined in rats suspended for 15 and 30 d. The results showed that inhibitory changes of both local factors (proteins secreted by bone cell, Ca(2+)-ATPase in sarcoplasmic reticium) and integrated regulative factors (immune factor, growth hormone) were observed simultaneously with the decrease of bone mineral content, calcium transportation in skeletal muscles as well as erythrocyte deformability. It suggests that both local and integrated regulative processes are functioning in response to the effects of weightlessness.

A quantitative study on vascular angiotensin II receptors in rats with portal hypertension

Angiotension-II (A-II) receptor maximal binding capacity (Bmax) and dissociation constants (Kd) of different blood vessels in rats with prehepatic portal hypertension were studied by radioligand binding analysis. The results showed that the A-II receptor Bmax in the thoracic aorta, superior mesenteric artery and portal vein of portal hypertensive animals (113.7 +/- 19.4 fmol/mg protein, 206.9 +/- 39.3 fmol/mg protein and 31.5 +/- 9.2 fmol/mg protein respectively) was all significantly lower than that of controls (146.8 +/- 24.5 fmol/mg protein, 297.2 +/- 44.7 fmol/mg protein and 53.4 +/- 12.1 fmol/mg protein respectively, P < 0.01). The A-II receptor Kd in the superior mesenteric artery was markedly increased in portal hypertensive animals (1.03 +/- 0.11 nmol/L) compared with that in controls (0.88 +/- 0.08 nmol/L, P < 0.05). In the thoracic aorta and portal vein, the A-II receptor Kd in portal hypertensive animals was slightly higher than that in controls, but no significant difference was observed between the two groups. The results suggested that the vascular hyporesponsiveness to A-II in portal hypertension was caused partially by a reduction in number and a decrease in affinity of vascular A-II receptors, and these changes might possibly lead to the formation of hyperdynamic circulation.

TGFbeta1 inhibits the formation of benign skin tumors, but enhances progression to invasive spindle carcinomas in transgenic mice

TGFbeta1 has been implicated in cell cycle control and carcinogenesis. To address the exact function of TGFbeta1 in skin carcinogenesis in vivo, mice with TGFbeta1 expression targeted to keratinocytes were subjected to long-term chemical carcinogenesis treatment. TGFbeta1 showed biphasic action during multistage skin carcinogenesis, acting early as a tumor suppressor but later enhancing the malignant phenotype. The transgenics were more resistant to induction of benign skin tumors than controls, but the malignant conversion rate was vastly increased. There was also a higher incidence of spindle cell carcinomas, which expressed high levels of endogenous TGFbeta3, suggesting that TGFbeta1 elicits an epithelial-mesenchymal transition in vivo and that TGFbeta3 might be involved in maintenance of the spindle cell phenotype. The action of TGFbeta1 in enhancing malignant progression may mimic its proposed function in modulating epithelial cell plasticity during embryonic development.

Altered epidermal cell growth control in vivo by inducible expression of transforming growth factor beta 1 in the skin of transgenic mice

An inducible bovine KIV* keratin gene promoter was used to target expression of latent or activated transforming growth factor beta 1 (TGF beta 1) to keratinocytes in transgenic mice. This short (2.2-kb) keratin 6 (K6) promoter element was generally silent in untreated animals but was induced in keratinocytes when placed in culture or, in vivo, in response to hyperplasia that follows topical application of the tumor promoter, 12-O-tetradecanoylphorbol-13-acetate. All of the K6-TGF beta 1 transgenic lines studied showed attenuation of the basal keratinocyte proliferative response to 12-O-tetradecanoylphorbol-13-acetate as a consequence of inducible TGF beta 1 gene expression. One of the six lines studied showed constitutive transgene expression at low levels in the skin, and this line had a 2- to 3-fold increase in epidermal DNA labeling index over control mice. Although in vitro TGF beta 1 is known to be a potent negative regulator of epithelial cell proliferation, in vivo TGF beta 1 has complex biological activities and can act as either a positive or negative regulator of keratinocyte proliferation.

[Clinical significance of ophthalmo-electromyography in the determination of the function of the superior levator muscle]

Preoperative electromyographic examinations of superior levator muscle were done in 36 ptotic patients using the Neurematic 2000 electromyograph. Shortening of the levator palpebrae superior was done through a combined internal and external route. In 12 patients of mild ptosis the spike voltage was all above 30 mv during contraction. When the spike voltage was above 100 mv, better operative results were obtained. In 24 patients whose ptosis was moderate or severe, the graphs of contraction generally showed simple phases with low amplitude. In 9 patients whose spike voltage was below 30 mv, their palpebral fissure did not reach the anticipated width after the operation. On the contrary, in 15 patients whose spike voltage was above 30 mv the operative results were satisfactory. It is concluded that in patients whose ptosis is moderate or severe, the operative procedure should be based on electromyographic examinations. If the spike voltage of the superior levator muscls is higher than 30 mv on contraction, simple shortening of the levator will be successful. If the spike voltage is lower than 30 mv and the graph presents simple phase or electro-tranquilization, then suspension of the frontalis muscle is preferable.

Characterization of the glucose-induced inactivation of maltose permease in Saccharomyces cerevisiae

The addition of glucose to maltose-fermenting Saccharomyces cerevisiae cells causes a rapid and irreversible loss of the ability to transport maltose, resulting both from the repression of transcription of the maltose permease gene and from the inactivation of maltose permease. The latter is referred to as glucose-induced inactivation or catabolite inactivation. We describe an analysis of this process in a maltose-fermenting strain expressing a hemagglutinin (HA)-tagged allele of MAL61, encoding maltose permease. The transfer of maltose-induced cells expressing the Mal61/HA protein to rich medium containing glucose produces a decrease in maltose transport rates which is paralleled by a decrease in Mal61/HA maltose permease protein levels. In nitrogen starvation medium, glucose produces a biphasic inactivation, i.e., an initial, rapid loss in transport activity (inhibition) followed by a slower decrease in transport activity, which correlates with a decrease in the amount of maltose permease protein (proteolysis). The inactivation in both rich and nitrogen-starved media results from a decrease in Vmax with no apparent change in Km. Using strains carrying mutations in END3, REN1(VPS2), PEP4, and PRE1 PRE2, we demonstrate that the proteolysis of Mal61/HAp is dependent on endocytosis and vacuolar proteolysis and is independent of the proteosome. Moreover, we show that the Mal61/HA maltose permease is present in differentially phosphorylated forms.

Modeling and mutagenesis of the human alpha 1a-adrenoceptor: orientation and function of transmembrane helix V sidechains

A 3-dimensional model of the seven transmembrane helical segments (TMs) of the human alpha 1a-adrenoceptor was initially built by analogy to the known structure of bacteriorhodopsin. However, the rotational orientation of TM V about its helical axis, and the roles of several TM V residues in ligand binding and receptor activation remained in question. Accordingly, we determined the effects of six site-specific mutations in TM V on binding affinity and functional potency of a structurally diverse series of agonists and antagonists. Mutation of Ser 192 and Phe 193 disrupted the binding of many of the tested ligands, as measured by displacement of [3H]prazosin. In addition, mutation of Ser 188, Ser 192, and Phe 193 disrupted receptor activation, as measured by [3H]inositol phosphate formation. On the basis of these results, a specific rotational orientation of TM V is proposed as part of a revised receptor model, which also takes into account more recently reported information about the structure of rhodopsin. This revised alpha 1a-adrenoceptor model accounts for direct interactions which are proposed between Ser 188 and Ser 192 and the meta and para hydroxyl groups of norepinephrine, respectively, in the G-protein coupled receptor state.

[Mutation of P53 gene in a highly metastatic human lung cancer cell line]

PG cell line, derived from a lung giant cell carcinoma, has the characteristics of rapid growth and high tumorigenicity. When transplanted to nude mice, spontanious metastasis to lung and lymphnode is high in frequency and stable. To understand the molecular basis of PG's biological behaviors, expression of tumor suppressor gene p53 was studied. It was found that expression of p53 protein was increased as demonstrated by immunohistochemical stainning. A change in polymorphsim in exon 7 of p53 gene was detected by nonisotopic PCR-SSCP, suggesting a change in base composition. Thermal cycling sequencing of both strands of exon 7 demonstrated a transversion of CGG to CTT at codon 248. Similar study with the same methods on Ki-ras oncogene was done, but no mutation was found. The relationship between p53 gene mutation and the metastatic potential of PG cells needs further exploration.

A practical procedure for the cryopreservation of marrow cells intended for autotransplantation

A simple and practical method of unfractionated bone marrow processing and cryopreservation was studied. The date shows that RBCs can be rapidly sedimented by methylcellulose or sodium carboxymethyl starch within 15-45 min. The cells can be cryopreserved in a mixture consisting of 5% DMSO, 6% HES and 4% Albumin prepared in a Lactated Ringer solution which is widely used, and can be simply immersed into a -80 degrees C freezer and stored in liquid nitrogen until infusion. Recovery percentages of nucleated cell, cell viability and CFU-G were similar to those cryopreserved with the conventional method. Clinical toxicity was mild in 12 infused patients. Of them 8 patients had received high dose chemotherapy +/- TBI and their peripheral WBC recovery was rapid. The recovery of WBC or Platelet (PLT) in the study group was similar to that of the control group whose marrow cells were cryopreserved in 10% DMSO. Therefore, cells cryopreserved with this method can also accelerate the hematopoietic recovery in myeloablatively treated patients.

Concerted action of TGF-beta 1 and its type II receptor in control of epidermal homeostasis in transgenic mice

Transforming growth factor-beta 1 (TGF-beta 1) is a modulator of cellular proliferation, differentiation, and extracellular matrix deposition. It is a potent epithelial growth inhibitor and can alter the differentiative properties of keratinocytes, in vitro, but little is known about its normal physiological function in the epidermis in vivo. Transgenic mice were generated using a keratin 10 (K10) gene promoter to drive constitutive expression of TGF-beta 1 in the suprabasal keratinocyte compartment. Surprisingly, these mice showed a two- to threefold increase in epidermal DNA labeling index over control mice, in the absence of hyperplasia. The transgene, however, acted in the expected fashion, as a negative regulator of cell growth, when hyperplasia was induced by treatment by 12-tetradecanoyl-phorbol-13-acetate (TPA). Epidermal TGF-beta type I and II receptor (T beta RI and T beta RII) levels were examined in control and transgenic mice during induction of hyperplasia by TPA. Whereas T beta RI levels remained relatively constant, T beta RII expression was strongly induced in TPA-treated skins, prior to the induction of the growth inhibitory response to TGF-beta 1, and its level of expression correlated with growth sensitivity to TGF-beta 1 in vivo and in vitro. These results suggest that TGF-beta 1 and its type II receptor are part of the endogenous homeostatic regulatory machinery of the epidermis.

Lack of transforming growth factor-beta 1 expression in benign skin tumors of p53null mice is prognostic for a high risk of malignant conversion

Expression of transforming growth factor beta 1 (TGF beta 1) protein was examined in chemically induced benign skin tumors with genetically defined empirical risks for malignant conversion. Benign tumors induced in mice which have both alleles of the p53 gene deleted have a malignant conversion frequency of approximately 50%, whereas similar tumors induced in wildtype and heterozygous p53 mice have conversion probabilities of 3 and 8%, respectively (Kemp et al., Cell, 74: 813-822, 1993). The TGF beta 1 antibody, anti-CC (1-30-1), was shown to stain either the proliferative keratinocyte compartment of the tumor or the tumor stroma, whereas another TGF beta 1 antibody, anti-LC (1-30-1), stained highly differentiated granular cells of the tumors. A strong correlation was found between staining of the proliferative keratinocyte compartment of tumors with the anti-CC (1-30-1) antibody and tumor genotype. Only 18% (6 of 32) of homozygous p53 null tumors showed any basal keratinocyte staining with this antibody, whereas over 80% (32 of 38) of heterozygous and wild-type tumors showed positive staining. Additionally, in most tumors examined, the spatial distribution of staining for the proliferating cell nuclear antigen appeared to be mutually exclusive with that of TGF beta 1 on adjacent serial sections. This suggests that, in these cases, tumor keratinocytes are sensitive to negative growth regulation by TGF beta. TGF beta 1 protein staining in benign tumors is thus prognostic for a low probability of malignant conversion, and its expression may be mechanistically involved in limiting malignant conversion since, at the benign tumor stage examined, keratinocytes are still sensitive to growth inhibition by TGF beta 1.