Anesthesia of CO2 laser surgery in a patient with Hunter syndrome: case report

Hunter syndrome (mucopolysaccharidosis, type II; MPS II) is one of a heterogeneous group of recessively inherited mucopolysaccharide storage diseases. Patients with mucopolysaccharidosis show progressive involvement and derangement of many organs, especially upper airway anomalies, which are the major cause of perioperative death. In recent years, a CO2 laser is often applied to upper airway lesions. A 16-year-old patient suffering from Hunter syndrome was scheduled for CO2 laser surgery because of sleep apnea and respiratory stridor. Otolaryngological examination revealed bulging of the bilateral false cord with stenosis of the glottis. We adopted sevoflurane mask induction and high-frequency jet ventilation to overcome the perioperative airway problems. The anesthetic course was uneventful, and the patient was discharged 2 days after the operation.

Respiratory management after self-extubation

BACKGROUND AND PURPOSE

Self-extubation is a potentially life-threatening event, but may also provide an opportunity to wean patients who should have been extubated earlier. The purpose of this study was to determine the risk factors for re-intubation after self-extubation.

METHODS

The medical charts of 69 self-extubated patients treated in Shin Kong Hospital, Taipei, from September 1996 through August 1998 were reviewed. Demographic data, ventilator settings before self-extubation, arterial blood gas values, and the type of respiratory management used after self-extubation were examined to determine their association with re-intubation.

RESULTS

Of the 69 self-extubated patients, 38 fared well without further ventilatory support after self-extubation. Four factors were associated with extubation outcome: 1) mean pre-extubation FiO2 (fraction of inspired oxygen), which was significantly higher in the re-intubated group (RI) than in the not re-intubated group (NRI) (0.48 vs 0.33, p = 0.002)--all self-extubated patients receiving an FiO2 of more than 0.40 were re-intubated; 2) PaO2/FiO2 (ratio of arterial oxygen tension to inspired oxygen concentration), which was lower in the RI group than in the NRI group (259.4 vs 346.4, p = 0.005); 3) requirement for assist/control ventilatory mode--patients needing this type of ventilatory support had a greater likelihood of reintubation than those requiring partial ventilatory support (odds ratio [OR], 3.790; confidence interval [CI], 1.055-13.621; p = 0.041); and 4) female sex (OR 0.188; CI 0.048-0.732; p = 0.016).

CONCLUSIONS

About half of self-extubated patients may not require re-intubation. Pre-extubation FiO2, PaO2/FiO2, and ventilator mode, as well as gender, may be useful in determining the likelihood that a self-extubated patient will require re-intubation.

Effects of VEGF121 and/or VEGF165 gene transfection on collateral circulation development

BACKGROUND AND PURPOSE

Angiogenesis is regulated by various factors, including vascular endothelial growth factor (VEGF). Five isoforms of VEGF have been discovered: VEGF121, VEGF145, VEGF165, VEGF189, and VEGF206. The teleologic basis for the various VEGF isoforms remains unclear, but different VEGF isoforms may mediate distinct endothelial cell functions such as angiogenesis, vascular permeability, and differentiation. We sought to determine the effects of various VEGF isoforms on angiogenesis under ischemic conditions in rabbits.

METHODS

The effects of VEGF121 and/or VEGF165 gene transfection on collateral circulation development in ischemic rabbit hindlimb muscles were investigated by using naked plasmids encoding VEGF121 or VEGF165 (pVEGF121 or pVEGF165), either individually or in combination. pCMV beta was used as the control plasmid. The femoral artery on one side of New Zealand White rabbits was ligated. Ten days later, the ischemic muscles received direct intramuscular injection of pVEGF121 (500 micrograms), pVEGF165 (500 micrograms), or pVEGF121 (250 micrograms) + pVEGF165 (250 micrograms) in experimental groups, while pCMV beta (500 micrograms) was used in the control group. Therapeutic effects were evaluated 30 days later by anatomic and physiologic analysis.

RESULTS

Internal iliac angiography showed strong development of collateral circulation in all of the pVEGF-treated groups. In contrast, collateral arteries developed weakly in the control group. Combination treatment with both pVEGF121 and pVEGF165 did not result in additional improvement compared with pVEGF121 or pVEGF165 treatment alone (angiographic scores: pVEGF121 = 0.85 +/- 0.10; pVEGF165 = 0.81 +/- 0.11; pVEGF121 + pVEGF165 = 0.83 +/- 0.09; control = 0.53 +/- 0.09; p < 0.01). A favorable response in the development of circulation at the capillary level with pVEGF121 and/or pVEGF165 versus pCMV beta was also found. Blood pressure measurement and regional blood flow measurement using colored microspheres revealed similar results.

CONCLUSIONS

Our results show that direct intramuscular injection of naked DNA encoding VEGF121 or VEGF165, individually or in combination, is an effective method for gene transfer in an animal model of ischemic limbs and results in augmented collateral vascular development and tissue perfusion.

Antibacterial mechanism of allyl isothiocyanate

Allyl isothiocyanate (AITC), a natural compound in plants belonging to the family Cruciferae, has been shown to have strong antimicrobial activity in liquid media as well as in its vapor form. To understand its antimicrobial mechanism, AITC was tested for bactericidal activities to Salmonella Montevideo, Escherichia coli O157:H7, and Listeria monocytogenes Scott A at different stages of growth and was compared with streptomycin, penicillin G, and polymyxin B, each of known antibacterial mechanisms. Bactericidal activities were determined by measuring bacterial viability and leakage of metabolites. To determine its effects on membrane permeability, beta-galactosidase activity was examined after exposure of E. coli K-12 strain 3.300 to the three antibiotics and to AITC. The two gram-negative bacteria, Salmonella Montevideo and E. coli O157:H7, were more sensitive to AITC and to polymyxin B than the gram-positive L. monocytogenes. AITC and polymyxin B were effective bactericidal agents to bacteria at all growth stages, whereas penicillin G and streptomycin did not exhibit bactericidal activity to stationary cells. High A260 and A280 values of cellular filtrate and beta-galactosidase activity were obtained after treatments of AITC and polymyxin B. These data indicated that AITC was most similar to polymyxin B with respect to its antibacterial effect on cell membranes and on leakage of cellular metabolites. Gaseous AITC caused metabolite leakages, measurable increases in 3-galactosidase activity, and reduction of viable bacteria. The effectiveness of AITC in inhibiting bacteria at all growth stages and its strong activity in vapor phase support its application in food preservation.

Cloning and functional characterization of a constitutively expressed nitrate transporter gene, OsNRT1, from rice

Elucidating how rice (Oryza sativa) takes up nitrate at the molecular level could help improve the low recovery rate (<50%) of nitrogen fertilizer in rice paddies. As a first step toward that goal, we have cloned a nitrate transporter gene from rice called OsNRT1. OsNRT1 is a new member of a growing transporter family called PTR, which consists not only of nitrate transporters from higher plants that are homologs of the Arabidopsis CHL1 (AtNRT1) protein, but also peptide transporters from a wide variety of genera including animals, plants, fungi, and bacteria. However, despite the fact that OsNRT1 shares a higher degree of sequence identity with the two peptide transporters from plants (approximately 50%) than with the nitrate transporters (approximately 40%) of the PTR family, no peptide transport activity was observed when OsNRT1 was expressed in either Xenopus oocytes or yeast. Furthermore, contrasting the dual-affinity nitrate transport activity of CHL1, OsNRT1 displayed only low-affinity nitrate transport activity in Xenopus oocytes, with a K(m) value of approximately 9 mM. Northern-blot and in situ hybridization analysis indicated that OsNRT1 is constitutively expressed in the most external layer of the root, epidermis and root hair. These data strongly indicate that OsNRT1 encodes a constitutive component of a low-affinity nitrate uptake system for rice.

Bactericidal activity of isothiocyanate against pathogens on fresh produce

The bactericidal activity of allyl and methyl isothiocyanate (AITC and MITC) was tested with a rifampicin-resistant strain of Salmonella Montevideo and streptomycin-resistant strains of Escherichia coil O157:H7 and Listeria monocytogenes Scott A. Iceberg lettuce inoculated with high (10(7) to 10(8) CFU/g) and low (10(3) to 10(4) CFU/g) concentrations of bacterial pathogens was treated with AITC and MITC in sealed containers at 4 degrees C for 4 days. AITC showed stronger bactericidal activity than MITC against E. coli O157:H7 and Salmonella Montevideo, whereas MITC showed stronger activity against L. monocytogenes than E. coli O157:H7 and Salmonella Montevideo. Up to 8-log reduction occurred with E. coli O157:H7 and Salmonella Montevideo on lettuce following treatment with vapor generated from 400 microl of AITC for 2 and 4 days, respectively. AITC was used to treat tomatoes inoculated with Salmonella Montevideo on stem scars and skin and apples inoculated with E. coli O157:H7 on stem scars. The bactericidal effect of AITC varied with bacteria species and exposure time. Salmonella Montevideo inoculated on tomato skin was more sensitive to AITC than that on stem scars. Treatment with vapor generated from 500 microl of AITC caused an 8-log reduction in bacteria on tomato skin but only a 5-log reduction on tomato stem scars. The bactericidal activity of AITC was weaker for E. coli O157:H7 on apple stem scars; only a 3-log reduction in bacteria occurred when 600 microl of AITC was used.

Mouse endostatin inhibits the formation of lung and liver metastases

Angiogenesis is required for tumor formation. Several studies have demonstrated that tumor angiogenesis is regulated by a balance between proangiogenesis and antiangiogenesis factors and that this balance varies in different organ environments. To investigate whether expression of an angiogenesis inhibitor by cancer cells could alter this balance and prevent tumor formation in different organ environments, we engineered stable transfectants from RenCa mouse renal carcinoma cells and SW620 human colon carcinoma cells to constitutively secrete a mouse endostatin protein with c-myc and polyhistidine (His) tags. Production and secretion of the endostatin-c-myc-His fusion protein by endostatin-transfected cells were confirmed by immunofluorescence staining and Western blot analysis. The endostatin transfectants and control transfectants, stably transfected with a control plasmid, had similar in vitro growth rates compared with their parental cell lines. Conditioned medium from endostatin-transfected cells inhibited human umbilical vein endothelial cell proliferation by 36-51% compared with conditioned medium from control cells. After inoculation into mice, flank tumors from endostatin-transfected cells were 73-91% smaller than flank tumors from control cells after 3 weeks. Inoculation of a cell mixture containing 25% endostatin-transfected cells and 75% control cells resulted in inhibition of flank tumor formation as effective as after inoculation of 100% endostatin-transfected cells. Formation of lung metastases by RenCa endostatin-transfected cells and formation of liver metastases by SW620 endostatin-transfected cells were dramatically inhibited compared with formation of metastases by control cells. These findings demonstrate that endostatin can inhibit tumor formation in different organ environments and that gene delivery of endostatin into even a minority of tumor cells may be an effective strategy to prevent progression of micrometastases to macroscopic disease.

Towards metabolic sink therapy for mut methylmalonic acidaemia: correction of methylmalonyl-CoA mutase deficiency in T lymphocytes from a mut methylmalonic acidaemia child by retroviral-mediated gene transfer

The pathology associated with mut methylmalonic acidaemia (MMA) is caused by systemic accumulation of methylmalonate. Therefore, removal of methylmalonate from the circulation of affected individuals by an engineered metabolic system is proposed as a potential treatment. The haematopoietic cell is a potential site for such a metabolic system because of its direct contact with the accumulated metabolite and the demonstrated safety and ease in utilizing this cell. In this study, we assessed the feasibility of developing a haematopoietic cell-based methylmalonate sink by analysing propionate/methylmalonate metabolism in a variety of haematopoietic cells. The results show that propionate metabolism and methylmalonyl-CoA mutase (MCM) activity are intact in primary T cells, EBV-B cells, and CD34+ haematopoietic stem cell-derived granulocytes, whereas they are defective in those from a mut MMA child. Moreover, normal T and EBV-B cells clear methylmalonate from the medium at a significant rate. Transduction of MCM-deficient T cells with a recombinant retrovirus encoding the human MCM cDNA results in correction of propionate metabolism. These results establish the basis for developing haematopoietic cell-based metabolic sink therapy for mut MMA by T lymphocyte/haematopoietic stem cell-directed gene transfer.

Cardiogenic shock in a patient with glyphosate-surfactant poisoning

We present a case of glyphosate-induced cardiogenic shock in a young man. The patient a 26-year-old man, presented with nausea and vomiting 4 hours after attempting suicide by drinking 150 mL of glyphosate surfactant. Cardiogenic shock with accelerated idio-ventricular rhythm on electrocardiography developed after admission. Intravenous injection of epinephrine, atropine, and calcium failed to improve the condition. Over the next 16 hours, the QRS complex gradually narrowed, sinus rhythm returned, and the hemodynamic status improved. Echocardiograms revealed diffuse left ventricular hypokinesis with markedly reduced ejection fraction while the patient was in shock; normal left ventricular function resumed the next day. In this case, the glyphosate surfactant poisoning-induced shock may have been due to transient suppression of the cardiac conduction system and contractility, rather than intravascular hypovolemia.

Evaluation of serum CA27.29, CA15-3 and CEA in patients with breast cancer

The Truquant BR radioimmunoassay (RIA) using monoclonal antibody BR 27.29 to recognize a peptide sequence on the MUC-1 gene product for quantification of the CA 27.29 antigen in serum was used in this report to evaluate in 145 patients with breast cancer and compared the other conventional serum markers such as CA15-3 and CEA. The upper limit of normal (25 u/ml) was determined from CA27.29 values 12.4 +/- 4.1 u/ml (mean +/- 3 S.D.) for 112 female subjects apparently free of disease. The CA15-3 levels above 25 u/ml and CEA levels above 5 ng/ml were considered positive values. Thirty-seven cases of 145 patients studied had elevated CA 27.29 levels (sensitivity: 25.5%), 35 of 145 had positive CA15-3 levels (sensitivity 24.1%) and 27 of 145 patients had positive CEA levels (sensitivity: 18.6%) (p < 0.05). One hundred and ten cases of the breast cancer patients (75.8%) did not have metastatic disease. In this group CA 27.29 sensitivity was 6.4%, while CA15-3 sensitivity was 5.5% and CEA sensitivity was 4.5% (p > 0.05). Mean values were 10.2 +/- 9.2 u/ml for CA 27.29, 14.1 +/- 5.6 u/ml for CA 15-3 and 1.7 +/- 1.5 ng/ml for CEA. Thirty-five patients (24.2%) had metastatic disease. In this group CA 27.29 sensitivity was 85.7%, CA15-3 sensitivity was 82.8% and CEA sensitivity was 62.8% (p < 0.05). Mean values for CA27.29 was 152.6 +/- 131.6 u/ml, CA15-3 was 123.1 +/- 107.6 u/ml and 21.8 +/- 36.9 ng/ml of CEA. With regard to the correlation of three tumor markers with clinical stages, patients had significantly higher levels of CA27.29 than CEA, but they were similar to CA 15-3 in metastatic breast cancer. These results suggest CA27.29 to be more sensitive and specific than CEA, but that it is similar to CA15-3 for metastatic breast cancer detection and monitoring.

Effect of dietary glutamate on chemotherapy-induced immunosuppression

Chemotherapy causes severe host immune depression and consequently increases susceptibility to infection. Dietary glutamate (GLU) serves as a stable substrate for the formation of glutamine (GLN), which is an important fuel and metabolic precursor for the immune cells. The effect of addition of GLU to a GLN/GLU-free amino acid diet upon immune response was studied in rats recovering from chemotherapy. Animals were fed a 0, 4, or 8% GLU diet and received a single intraperitoneal injection of methotrexate (MTX, 20 mg/kg BW). Two in vivo immune tests, delayed-type hypersensitivity (DTH) and popliteal lymphoproliferation (PLP), were performed 3 and 7 d after MTX treatment. Food intake and body weight decreased significantly immediately after MTX treatment and gradually recovered after 8 d with no significant difference among treatment groups. In a 23-d feeding study, no significant difference was found in the DTH response, but the PLP response increased in a GLU dose related fashion (83 and 133% increases for the 4 and 8% GLU diets, respectively). In a 44-d feeding study, the DTH response increased 61 and 83%, while the PLP response increased 191 and 382% for the 4 and 8% GLU diets, respectively. Plasma GLN, GLU, or glutathione (GSH) levels were increased by dietary GLU, but only in the immediate postprandial state. In summary, dietary GLU improves immune status of rats recovering from MTX treatment. The immune-enhancing effect of dietary GLU was dose-dependent and more pronounced after a longer duration of dietary GLU intake.

Cutting edge: trimolecular interaction of TCR with MHC class II and bacterial superantigen shows a similar affinity to MHC:peptide ligands

Bacterial superantigens such as Staphylococcus aureus enterotoxin A (SEA) are very potent stimulators of T cells. They bind to the Vbeta region of the TCR and to MHC class II, stimulating T cells at nanomolar concentrations. Using surface plasmon resonance measurements, we find that binding between the individual components of the complex (TCR-class II, TCR-SEA, SEA-class II) is very weak, but that the stability of the trimolecular complex is considerably enhanced, reaching an affinity similar to that found for TCR interactions with MHC:peptide ligand. Thus, the potency of SEA in stimulation of T cells is not due to particularly strong affinities between the proteins, but to a cooperative effect of interactions in the TCR-SEA-MHC class II trimolecular complex that brings the kinetics into a similar range to binding of conventional Ags. This range may be the optimum for T cell activation.

Virus reduction in the preparation of intravenous immune globulin: in vitro experiments

BACKGROUND

While immune globulins for intravenous administration (IGIV) have an excellent record with respect to virus safety, concern regarding these preparations has been raised by reports of transmission of hepatitis C virus (HCV) to patients treated with IGIV and the presence of genetic material for HCV in IGIV preparations.

STUDY DESIGN AND METHODS

This in vitro study evaluated the effectiveness of several manufacturing steps, including ethanol precipitation and pasteurization, in reducing HIV and model viruses including encephalomyocarditis (EMC) virus, pseudorabies virus (PRV), bovine viral diarrhea virus (BVDV), Sindbis virus, vaccinia virus, and vesicular stomatitis virus (VSV), as well as HCV RNA, in IGIV.

RESULTS

Ethanol precipitation carried out after pasteurization resulted in virus reductions (log10) of >3.97 for HIV, 1.95 for EMC virus, >5.39 for PRV, and 3.52 for BVDV. Pasteurization inactivated EMC virus by 4.52 log10 and resulted in a log10 reduction of >6.54 for HIV, >5.39 for PRV, >6.64 for BVDV, >7.78 for Sindbis virus, >5.84 for vaccinia virus, and >6.99 for VSV. All viruses except EMC virus were reduced below the limit of detection within 6 hours of the beginning of pasteurization. Cohn processing of Fraction II + III paste and the 4.5-percent alcohol precipitation step prior to pasteurization provided additional virus removal. Studies using the polymerase chain reaction technique found that HCV RNA was detectable in the starting fraction of Cohn Fraction II paste, but not in the final IGIV preparation.

CONCLUSION

These findings strongly support the viral safety of IGIV prepared by this method and show a significant added measure of virus safety associated with pasteurization of this preparation.

Qualitative and quantitative differences in T cell receptor binding of agonist and antagonist ligands

The kinetics of interaction between TCR and MHC-peptide show a general relationship between affinity and the biological response, but the reported kinetic differences between antigenic and antagonistic peptides are very small. Here, we show a remarkable difference in the kinetics of TCR interactions with strong agonist ligands at 37 degrees C compared to 25 degrees C. This difference is not seen with antagonist/positive selecting ligands. The interaction at 37 degrees C shows biphasic binding kinetics best described by a model of TCR dimerization. The altered kinetics greatly increase the stability of complexes with agonist ligands, accounting for the large differences in biological response compared to other ligands. Thus, there may be an allosteric, as well as a kinetic, component to the discrimination between agonists and antagonists.

Glutamine synthetase expression in rat lung is regulated by protein stability

During physiological stress, the lung increases production of the amino acid glutamine (Gln) using the enzyme Gln synthetase (GS) to maintain Gln homeostasis. Glucocorticoid hormones are considered the principal mediators of GS expression during stress. However, whereas animal studies have shown that glucocorticoids increase lung GS mRNA levels 500-700%, GS activity levels rise only 20-45%. This discrepancy suggests that a posttranscriptional control mechanism(s) ultimately determines GS expression. We hypothesized that the level of GS protein in the lung is governed by the intracellular Gln concentration through a mechanism of protein destabilization, a feedback regulatory mechanism that has been observed in vitro. To test this hypothesis, Sprague-Dawley rats were treated with a Gln-free diet and the GS inhibitor methionine sulfoximine (MSO) to deplete tissue Gln levels and prevent this feedback regulation. Exposure to Gln-free chow and MSO (100 mg/kg body wt) for 6 days decreased plasma Gln levels 50% (P < 0.01) and decreased lung tissue Gln levels by 70% (P < 0.01). Although lung GS mRNA levels were not influenced by Gln depletion, there was a sevenfold (P < 0.01) increase in GS protein. A parenteral Gln infusion (200 mM, 1.5 ml/h) for the last 2 days of MSO treatment replenished lung Gln levels to 65% of control level and blunted the increase in GS protein levels by 33% (P < 0.05) compared with rats receiving an isomolar glycine solution. The acute effects of glucocorticoid and MSO administration on lung GS expression were also measured. Whereas dexamethasone (0.5 mg/kg) and MSO injections individually augmented lung GS protein levels twofold and fourfold (P < 0.05), respectively, the combination of dexamethasone and MSO produced a synergistic, 12-fold induction (P < 0.01) in lung GS protein over 8 h. The data suggest that, whereas glucocorticoids are potent mediators of GS transcriptional activity, protein stability greatly influences the ultimate expression of GS in the lung.

Synthesis and biological evaluation of 2-acyl analogues of paclitaxel (Taxol)

The anticancer drug paclitaxel (Taxol) has been converted to a large number of 2-debenzoyl-2-aroyl derivatives by three different methods. The bioactivities of the resulting analogues were determined in both tubulin polymerization and cytotoxicity assays, and several analogues with enhanced activity as compared with paclitaxel were discovered. Correlation of cytotoxicity in three cell lines with tubulin polymerization activity showed reasonable agreement. Among the cell lines examined, the closest correlation with antitubulin activity was observed with a human ovarian carcinoma cell line.

Transgenic fish and its application in basic and applied research

Since 1985, transgenic fish have been successfully produced by microinjecting or electroporating desired foreign DNA into unfertilized or newly fertilized eggs using many different fish species. More recently, transgenic fish have also been produced by infecting newly fertilized eggs with pantropic, defective retroviral vectors carrying desired foreign DNA. These transgenic fish can serve as excellent experimental models for basic scientific investigations as well as in biotechnological applications. In this paper, we will review the current status of the transgenic fish research and its potential application in basic and applied research.

Expression of human phenylalanine hydroxylase activity in T lymphocytes of classical phenylketonuria children by retroviral-mediated gene transfer

Classical phenylketonuria (PKU) is a metabolic disorder caused by mutations in the phenylalanine hydroxylase (PAH) gene. At present, T lymphocyte-directed gene therapy is the only means for which a safety record has been established. Thus, we investigated the applicability of this strategy to PKU gene therapy. We first looked for tetrahydrobiopterin (BH4) and dihydropteridine reductase (DHPR) activity, which are required for the phenylalanine hydroxylation reaction and BH4 regeneration, respectively, in T cells isolated from PKU children. We found that T cells contained a small amount of biopterin, but significant DHPR activity, and that the intracellular biopterin content could be increased by exogenous BH4 supplementation. Moreover, PKU T cells were capable of taking up phenylalanine efficiently and effluxing acquired tyrosine. Finally, a recombinant retrovirus containing the human PAH cDNA was constructed and used to transduce isolated PKU T cells. Viral-transduced T cells produced high levels of PAH activity as compared to control mock-infected T cells. These results indicate that T lymphocytes express all that is required for synthesizing/replenishing constituents of the phenylalanine hydroxylation reaction and expressing transduced phenylalanine hydroxylase cDNA.

Antitumor agents. 178. Synthesis and biological evaluation of substituted 2-aryl-1,8-naphthyridin-4(1H)-ones as antitumor agents that inhibit tubulin polymerization

As part of our continuing search for potential anticancer drug candidates in the 2-aryl-1,8-naphthyridin-4(1H)-one series, we have synthesized two series of 3'-substituted 2-phenyl-1,8-naphthyridin-4(1H)-ones and 2-naphthyl-1,8-naphthyridin-4(1H)-ones. All compounds showed significant cytotoxic effects (log GI50 < -4.0; log molar drug concentration required to cause 50% growth inhibition) against a variety of human tumor cell lines of the National Cancer Institute's in vitro screen, including cells derived from solid tumors such as non-small cell lung, colon, central nervous system, melanoma, ovarian, prostate, and breast cancers. All 3'-substituted compounds demonstrated strong cytotoxic effects in almost all tumor cell lines. Introduction of an aromatic ring at the 2'- and 3'-positions also generated compounds with potent antitumor activity. Incorporation of an aromatic ring at the 3'- and 4'-positions produced compounds with reduced activity. Interestingly, introduction of a halogen at the 3'-position yielded compounds with different selectivity for the tumor cell lines tested. All 3'-halogenated compounds (29-36) and compounds 38 and 42-44 were potent inhibitors of tubulin polymerization with activities nearly comparable to those of the potent antimitotic natural products colchicine, podophyllotoxin, and combretastatin A-4. Active agents also inhibited the binding of [3H]colchicine to tubulin.

Evoked facial nerve EMG and brainstem auditory evoked potential monitoring in cerebellopontine angle tumor resection

BACKGROUND

The preservation of normal nerve function or identification of nerve route is critical in some surgeries of cerebellopontine angle tumors. Over the last 5 years, intraoperative facial nerve electromyogram (EMG) and brainstem auditory evoked potential (BAEP) were applied for evaluation of facial nerve integrity and brainstem function in patients while undergoing resection of cerebellopontine angle (CPA) tumor. This report represents the retrospective analysis of our results.

METHODS

The inhalational anesthesia with 1-1.5% isoflurane in pure O2 was used. Muscle relaxation was maintained with continuous infusion of atracurium. The degree of muscle relaxation was aimed at a T4/T1 ratio of train-of-four response more than 20% of the adductus pollicis upon ulnar nerve stimulation at the wrist. In 236 patients suffering from CPA tumor without facial palsy, the EMG of the mentalis muscle ipisilateral to the tumor was obtained through stimulation of the facial nerve. The stimulation was applied with a nerve finder, which delivered an electrical stimulation of a single 2 mamp direct current. The EMG finding was compared with the clinical result. In 198 patients, BAEP was used to monitor the brainstem function during tumor resection. In case of intact hearing the BAEP was taken ipsilateral to the operation side and in case with total hearing loss contralateral BAEP to operation side was used. For BAEP stimulation, 90 db click sound stimulation with frequency of 11.26 Hz was applied to both ears. BAEP signals were obtained and recorded at the mastoid region of either side in reference to the vertex. The EMG and BAEP signals were recorded and saved to an evoked potential monitor.

RESULTS

In facial nerve EMG monitoring, there were two false positive and no false negative tests. Except for the two false positive tests, the postoperative clinical results in the other cases were compatible with the intraoperative facial nerve EMG findings. In BAEP monitoring, there were twenty-eight positive tests.

CONCLUSIONS

The low incidence of false negative test suggests that facial nerve EMG is valuable in detection of facial nerve function in CPA tumor resection. Intraoperative BAEP abnormality is possibly useful in identifying postoperative brainstem dysfunction.

Synthesis of analogs of 2-methoxyestradiol with enhanced inhibitory effects on tubulin polymerization and cancer cell growth

A new series of estradiol analogs was synthesized in an attempt to improve on the anticancer activity of 2-methoxyestradiol, a naturally occurring mammalian tubulin polymerization inhibitor. The compounds were evaluated as inhibitors of tubulin polymerization and the binding of [3H]colchicine to tubulin, as well as for in vitro cytotoxicity in human cancer cell cultures. Overall, the most potent of the new compounds were 2-(2',2',2'-trifluoroethoxy)-6-oximinoestradiol, 2-ethoxy-6-oximinoestradiol, and 2-ethoxy-6-methoximinoestradiol. These agents lacked significant affinity for the estrogen receptor. The cytotoxicities of the compounds correlated in general with their abilities to inhibit tubulin polymerization, thus supporting inhibition of tubulin polymerization as the primary mechanism causing inhibition of cell growth.

Antitumor agents. 174. 2',3',4',5,6,7-Substituted 2-phenyl-1,8-naphthyridin-4-ones: their synthesis, cytotoxicity, and inhibition of tubulin polymerization

Two series of 2',3',4',5,6,7-substituted 2-phenyl-1,8-naphthyridin-4-ones and 2-phenylpyrido[1,2-alpha]pyrimidin-4-ones have been synthesized and evaluated as cytotoxic compounds and as inhibitors of tubulin polymerization. Most 2-phenyl-1,8-naphthyridin-4-ones showed potent cytotoxic and antitubulin activities, whereas 2-phenylpyrido[1,2-alpha]pyrimidin-4-ones showed no activity in either assay. In general, a good correlation was found between cytotoxicity and inhibition of tubulin polymerization in the 2-phenyl-1,8-naphthyridin-4-one series. The 2-phenyl-1,8-naphthyridin-4-ones (44-49) with a methoxy group at the 3'-position showed potent cytotoxicity against most tumor cell lines with GI50 values in the low micromolar to nanomolar concentration range in the National Cancer Institute's 60 human tumor cell line in vitro screen. Introduction of substituents (e.g. F, Cl, CH3, and OCH3) at the 4'-position led to compounds with reduced or little activity and substitution at the 2'-position resulted in inactive compounds. The effects of various A-ring substitutions on activity depend on the substitution in ring C. Compounds 44-50 were potent inhibitors of tubulin polymerization, with activity nearly comparable to that of the potent antimitotic natural products colchicine, podophyllotoxin, and combretastatin A-4. Compounds 44-49 also inhibited the binding of radiolabeled colchicine to tubulin, but the inhibition was less potent than that obtained with the natural products. Further investigation is underway to determine if substitution at the 3'-position and multisubstitutions in ring C will result in compounds with increased activity.

Synthesis and biological activity of A-nor-paclitaxel analogues

A number of paclitaxel analogues with a 5-membered A-ring (A-nor-paclitaxels, or (15-->1)-abeo-paclitaxels) have been prepared in order to determine whether analogues of this class might have improved bioactivity as compared with paclitaxel. Most of the compounds synthesized were less active than paclitaxel, but one analogue was equivalent to paclitaxel in a tubulin-assembly assay, and another analogue was more cytotoxic than paclitaxel in two different cell lines of the NCI screen.

Characterization of rainbow trout (Oncorhynchus mykiss) growth hormone 1 gene and the promoter region of growth hormone 2 gene

Studies by Agellon et al. (Mol. Reprod. Dev. 1, 11-17) showed the presence of two growth hormone (rtGH1 and rtGH2) mRNA species in pituitary glands of adult rainbow trout (Oncorhynchus mykiss). In this study, we have detected rtGH1 and rtGH2 mRNAs in pituitary glands of rainbow trout from fry to 2 years of age. The level of rtGH1 mRNA is notably higher than that of rtGH2 mRNA in 10-day-old fry and 2-year-old females. These results suggest differential expression of rtGH1 and rtGH2 genes in different sexes and developmental stages. As a step toward elucidating the mechanism of differential expression of both GH genes, DNA fragments encoding rtGH1 gene and the promoter/regulatory region of rtGH2 gene were isolated and characterized. Rainbow trout GH genes span approximately 4.5 kb and are composed of six exons and five introns. The 5'-flanking region of both genes contain consensus sequences for TATA boxes and several Pit-1 binding sequences. Consensus sequences related to the cAMP response element, thyroid hormone response element, retinoic acid response element, estrogen response element (ERE), and glucocorticoid response element are present not only in the 5'-flanking region, but also in introns and exons in rtGH1 gene. These hormone response elements, except ERE, are also present in rtGH2 gene.

Synthesis and biological evaluation of 1,1-dichloro-2,3-diarylcyclopropanes as antitubulin and anti-breast cancer agents

Z-1,1-Dichloro-2,3-diphenylcyclopropane (1) is an effective anti-breast cancer agent in rodents and in cell culture. We recently determined that 1 inhibits tubulin assembly in vitro and causes microtubule loss in breast cancer cells, leading to accumulation in the G2/M portion of the cell cycle. Aryl ring-halogenated, methoxylated and benzyloxylated derivatives of 1, as well as its E-isomer and the dichlorocyclopropyl derivative of diethylstilbestrol (DES), were synthesized and tested for their ability to inhibit, the assembly of tubulin into microtubules. Including 1, 17 cyclopropyl compounds were tested. One (Z-1,1-dichloro-2-(4-methoxyphenyl)-3-phenylcyclopropane (12)) was found to be more active than 1. In addition, E-1,1-dichlorocyclopropylDES (17) was more potent than DES. The E-isomer of 1 (16) was inactive. The cytostatic activities of the compounds against MCF-7 and MDA-MB231 human breast cancer cells, and their abilities to perturb microtubules in MCF-7 cells were also evaluated. Z-Dichloro-2-(4-fluorophenyl)-3-phenylcyclopropane (5), Z-1,1-dichloro-2-(4-fluorophenyl)-3-(4-methoxyphenyl)cyclopropane (11), and Z-1,1-dichloro-2-(4-methoxyphenyl)-3-phenylcyclopropane (12) were more potent than 1 against the breast cancer cells.

A convenient tubulin-based quantitative assay for paclitaxel (Taxol) derivatives more effective in inducing assembly than the parent compound

A room temperature biochemical assay, based on centrifugal removal of tubulin polymer, was developed to permit ready detection of paclitaxel analogs more active than the parent compound and to permit reliable quantification of differences in activity relative to paclitaxel in terms of drug concentration. The assay was validated by comparing paclitaxel to two compounds (docetaxel and 2-debenzoyl-2-meta-azidobenzoylpaclitaxel) known to be more active under multiple reaction conditions. The assay was designed to yield a relatively high EC50 (23 microM) for paclitaxel. This was possible because paclitaxel only weakly induced tubulin assembly at room temperature in 0.4 M glutamate without exogenous GTP. Under these same reaction conditions 50% assembly occurred with 4.7 microM 2-debenzoyl-2-meta-azidobenzoylpaclitaxel and 11 microM docetaxel. These biochemical EC50 values were in agreement with the relative cytotoxicity of the three compounds for human Burkitt lymphoma CA46 cells (IC50 values for paclitaxel, docetaxel, and 2-debenzoyl-2-meta-azidobenzoylpaclitaxel were 40, 10, and 3 nM, respectively).

Echocardiographic predictors of survival after surgery for mitral regurgitation in the age of valve repair

The objective of this study was to identify echocardiographic and clinical predictors of survival after mitral valve surgery when mitral repair is an option. In 132 patients undergoing mitral valve repair or replacement for the diagnosis of mitral regurgitation, preoperative echocardiograms were analyzed quantitatively and reviewed by two independent observers for structural abnormalities of the mitral valve. In Cox regression analysis, clinical factors such as age (mortality rate ratio [MRR] 1.7/decade, 95% confidence intervals [CI] 1.1, 2.4), and New York Heart Association class IV (MRR 3.1, 95% CI 1.4, 6.7) and echocardiographic factors including morphologic evidence of endocarditis or myxomatous disease (MRR 0.3, 95% CI 0.1, 0.7) were significant predictors of overall survival, although valve repair itself was not. End-systolic dimensions and volumes were not, likely related to the small number of patients with markedly increased end-systolic dimensions or volumes (5 patients [4%] with end-systolic dimension > 5.5 cm, 12 patients [9%] with end-systolic volume index > 60 ml/m2). New York Heart Association class IV (MRR 2.9, 95% CI 1.3, 6.4), age (MRR 1.7/decade, 95% CI 1.2, 2.6), and the presence of calcification (MRR 4.6, 95% CI 1.3, 16.2) were independent predictors of survival in multivariate analysis. In this contemporary cohort of patients undergoing repair or replacement for mitral regurgitation, factors such as echocardiographically determined cause of disease and presence of calcification predicted survival; traditional measurements such as end-systolic dimensions and volumes were less predictive, most likely because patients underwent surgery before their ventricles became markedly enlarged. Clinical factors such as age and functional status remained the most potent predictors of survival after surgery for mitral regurgitation.

Interactions of 2-methoxyestradiol, an endogenous mammalian metabolite, with unpolymerized tubulin and with tubulin polymers

2-Methoxyestradiol (2ME) is an endogenous mammalian catabolite of estradiol with antimitotic activity. Although it is a competitive inhibitor of the binding of colchicine to tubulin, it has unusual effects on glutamate-induced tubulin polymerization. Polymer that was little changed in morphology assembled at a reduced rate and was relatively cold stable. We have now examined interactions of [4-3H]-2ME with unpolymerized tubulin and polymer. The [3H]2ME binds avidly to tubulin even on ice, and it is readily displaced by other colchicine site drugs. An association rate constant on ice of 1.9 x 10(2) M-1s-1 was obtained. Scatchard analysis indicated a single class of binding site and an association equilibrium constant of 5.7 x 10(5) M-1. These values lead to a calculated dissociation rate constant of 3.3 x 10(-4) s-1. In glutamate-induced tubulin assembly, a reaction that requires GTP and leads to the formation of sheets of parallel protofilaments, increasing amounts of [3H]2ME were incorporated into polymer, reaching near-stoichiometry with tubulin at 100 microM 2ME. Equivalent binding of [3H]2ME occurred when the drug was added to preformed polymer, but binding of [3H]2ME to polymer was not readily inhibited by colchicine site drugs. Significant amounts of [3H]2ME were also incorporated into microtubule polymer formed with microtubule-associated proteins, glycerol, or 4-morpholineethanesulfonate buffer, but the stoichiometry was substantially lower than that in the sheet polymer induced by either glutamate or 1,4-piperazineethanesulfonate buffer. The structural differences between the microtubule and sheet polymers leading to these differences in apparent affinity for 2ME are unknown, but presumably interaction of the estrogen metabolite with cellular microtubules has functional significance related to the antimitotic properties of the compound.

Antitumor 2,3-dihydro-2-(aryl)-4(1H)-quinazolinone derivatives. Interactions with tubulin

A series of derivatives of 2,3-dihydro-2-(aryl)-4(1H)-quinazolinone (DHQZ) with known antitumor activity was re-evaluated in the National Cancer Institute cancer cell line screen. Analysis by the COMPARE algorithm suggested that their cytotoxicity derived from interactions with tubulin. Significant inhibition of tubulin assembly and of the binding of radiolabeled colchicine to tubulin was demonstrated with several of the compounds, particularly NSC 145669, 175635, and 175636. The DHQZ derivatives are structurally analogous to a number of antimitotic agents, flavonols and derivatives of 2-styrylquinazolin-4(3H)-one and of 2-phenyl-4-quinolone. Structure-activity analogies between these agents, the combretastatins, and the colchicinoids were analyzed and summarized.

Discodermolide, a cytotoxic marine agent that stabilizes microtubules more potently than taxol

Computer-assisted structure analysis indicated (+)-discodermolide, a polyhydroxylated alkatetraene lactone marine natural product, was an antimitotic compound, and we confirmed this prediction. Previous work had shown an accumulation of discodermolide-treated cells in the G2/M portion of the cell cycle, and we have now found that discodermolide arrests Burkitt lymphoma cells in mitosis. Discodermolide-treated breast carcinoma cells displayed spectacular rearrangement of the microtubule cytoskeleton, including extensive microtubule bundling. Microtubule rearrangement that occurred with 10 nM discodermolide required 1 microM taxol. Discodermolide had equally impressive effects on tubulin assembly in vitro. Near-total polymerization occurred at 0 degree C with tubulin plus microtubule-associated proteins (MAPs) under conditions in which taxol at an identical concentration was inactive. Without MAPs and/or without GTP, tubulin assembly was also more vigorous with discodermolide than with taxol under every reaction condition examined. Discodermolide-induced polymer differed from taxol-induced polymer in that it was completely stable at 0 degree C in the presence of high concentrations of Ca2+. In a quantitative assay designed to select for agents more effective than taxol in inducing assembly, discodermolide had an EC50 value of 3.2 microM versus 23 microM for taxol.

Interactions of tubulin with guanine nucleotides that have paclitaxel-like effects on tubulin assembly: 2',3'-dideoxyguanosine 5'-[alpha,beta-methylene]triphosphate, guanosine 5'-[alpha,beta-methylene]triphosphate, and 2',3'-dideoxyguanosine 5'-triphosphate

Despite reduced affinity for the exchangeable nucleotide binding site of tubulin relative to GTP, 2',3'-dideoxyguanosine 5'-triphosphate (ddGTP) and guanosine 5'-[alpha, beta-methylene]triphosphate [pp(CH2)pG] are highly active in promoting tubulin assembly. Like the antimitotic drug paclitaxel, which interacts with the same part of the beta-tubulin molecule as exchangeable-site GTP, both analogs enhance nucleation reactions and promote formation hyperstable polymers. These observations led us to synthesize the doubly modified analog 2',3'-dideoxyguanosine 5'-[alpha, beta-methylene]triphosphate [pp(CH2)pddG]. We compared the effects of pp(CH2)pddG to those of ddGTP, pp(CH2)pG, and the three-cognate diphosphates in their interactions with tubulin. We found that pp(CH2)pddG was as active as ddGTP and pp(CH2)pG in supporting formation of polymer of increased stability, but that its affinity for the exchangeable site was lower than that of both singly modified analogs [relative affinities for the exchangeable site for pp(CH2)pddG:ddGTP:pp(CH2)-pG:GTP were 1:2.8:10:273]. There were significant differences in interactions of each of the three analogs with tubulin, and the behavior of pp(CH2)pddG was intermediate between that of ddGTP and that of pp(CH2)pG. Most importantly, under the reaction conditions studied, with heat-treated microtubule-associated proteins (MAPs) ddGTP-induced polymer consisted of short microtubules, while polymer formed with both pp(CH2)pddG and pp(CH2)pG consisted of short sheets. On the other hand, assembly without MAPs had a fivefold lower critical concentration for tubulin with ddGTP and pp(CH2)pddG (0.5 mg/ml) than with pp(CH2)pG (2.5 mg/ml). De novo assembly, which occurs readily with 2',3'-dideoxyguanosine 5'-diphosphate, was not observed with either alpha, beta-methylenediphosphate GDP analog.

Effects of alcohol moderation on blood pressure and intracellular cations in mild essential hypertension

It is known that moderation of alcohol intake reduces blood pressure, although the exact mechanism has not yet been established. To clarify the hypotensive mechanism of alcohol reduction, we evaluated the change in cellular magnesium and sodium metabolism during alcohol reduction in mild hypertensive patients. We measured intraerythrocyte sodium and magnesium, intraplatelet free magnesium concentrations, and erythrocyte ouabain-sensitive 22Na efflux rate constant (Kos) in 17 mild essential hypertensive patients regularly consuming more than 40 g/day of alcohol, before and after 4 weeks of alcohol reduction, and 12 age-matched nondrinking hypertensives. Intraerythrocyte magnesium (P < .01) and intraplatelet free magnesium (P < .05) concentrations were significantly lower in drinkers than in nondrinkers. In drinkers, advice to reduce alcohol intake for 4 weeks resulted in a reduction in self-reported alcohol consumption from 461.7 to 71.6 g/week, a significant fall in both supine systolic blood pressure (136.3 +/- 10.8 to 130.8 +/- 11.3 mm Hg, P < .001) and supine diastolic blood pressure (85.1 +/- 8.6 to 82.6 +/- 8.7 mm Hg, P < .05). The fall in mean blood pressure correlated positively with the reduction in weekly alcohol consumption. Intraerythrocyte magnesium and Kos were increased (P < .05, P < .01, respectively), while intraerythrocyte sodium was decreased (P < .01). The increase in intraerythrocyte magnesium correlated negatively with the fall in mean blood pressure and positively with the increase in Kos, which correlated negatively with the decrease in intraerythrocyte sodium.(ABSTRACT TRUNCATED AT 250 WORDS)

Synthesis, antitubulin and antimitotic activity, and cytotoxicity of analogs of 2-methoxyestradiol, an endogenous mammalian metabolite of estradiol that inhibits tubulin polymerization by binding to the colchicine binding site

In order to define the structural parameters associated with the antitubulin activity and cytotoxicity of 2-methoxyestradiol, a mammalian metabolite of estradiol, an array of analogs was synthesized and evaluated. The potencies of the new congeners as inhibitors of tubulin polymerization and colchicine binding were determined using tubulin purified from bovine brain, and the cytotoxicities of the new compounds were studied in a variety of cancer cell cultures. Maximum antitubulin activity was observed in estradiols having unbranched chain substituents at the 2-position with three non-hydrogen atoms. 2-Ethoxyestradiol and 2-((E)-1-propenyl)-estradiol were substantially more potent than 2-methoxyestradiol itself. The tubulin polymerization inhibitors in this series displayed significantly higher cytotoxicities in the MDA-MB-435 breast cancer cell line than in the other cell lines studied. The potencies of the analogs as cytotoxic and antimitotic agents in cancer cell cultures correlated with their potencies as inhibitors of tubulin polymerization, supporting the hypothesis that inhibition of tubulin polymerization is the mechanism of the cytotoxic action of 2-methoxyestradiol and its congeners. Several of the more potent analogs were tested in an estrogen receptor binding assay, and their affinities relative to estradiol were found to be very low.

Antitumor agents, 154. Cytotoxic and antimitotic flavonols from Polanisia dodecandra

Three flavonols, 5,3'-dihydroxy-3,6,7,8,4'-pentamethoxyflavone [1], 5,4'-dihydroxy-3,6,7,8,3'-pentamethoxyflavone [2], and quercetin 3-O-beta-D-glucopyranosyl-7-O-alpha-L-rhamnopyranoside [3], were isolated from Polanisia dodecandra. Compound 1 showed remarkable cytotoxicity in vitro against panels of central nervous system cancer (SF-268, SF-539, SNB-75, U-251), non-small cell lung cancer (HOP-62, NCI-H266, NCI-H460, NCI-H522), small cell lung cancer (DMS-114), ovarian cancer (OVCAR-3, SK-OV-3), colon cancer (HCT-116), renal cancer (UO-31), a melanoma cell line (SK-MEL-5), and two leukemia cell lines (HL-60 [TB], SR), with GI50 values in the low micromolar to nanomolar concentration range. This substance also inhibited rubulin polymerization (IC50 = 0.83 +/- 0.2 microM) and the binding of radiolabeled colchicine to tubulin with 59% inhibition when present in equimolar concentrations with colchicine. Compound 2 also showed cytotoxicity against medulloblastoma (TE-671) tumor cells with an ED50 value of 0.98 microgram/ml. Compound 1 appears to be the first example of a flavonol to exhibit potent inhibition of tubulin polymerization and, therefore, warrants further investigation as an antimitotic agent.

Production of a biologically active recombinant teleostean growth hormone in E. coli cells

We have isolated and characterized several recombinant lambda phage clones carrying growth hormone (GH) cDNA of striped bass (Morone saxatilis). Nucleotide sequence and the predicted amino acid sequence of sbGH was determined from a recombinant clone carrying the longest cDNA insert. The sbGH cDNA encodes a pre-hormone of 204 amino acid residues. Comparison of the predicted amino acid sequence of sbGH with those of other vertebrates revealed different degrees of sequence identity: approximately 98% with European sea bass; 90% with bluefin tuna; bonito and red seabream; 71% with winter flounder; 64% with salmonids; 55% with carp; and 38% with human. Expression of the mature sbGH cDNA (without the signal peptide sequence) in E. coli cells under regulation of the lambda phage PL promoter produced a polypeptide of 20 kDa. Following renaturation, this recombinant hormone was shown to be biologically active in a radioreceptor competition binding assay and in the induction of hepatic insulin-like growth factor I (IGF-I) mRNA synthesis in vivo.

Antitumor agents. 155. Synthesis and biological evaluation of 3',6,7-substituted 2-phenyl-4-quinolones as antimicrotubule agents

A series of 3',6,7-substituted 2-phenyl-4-quinolones were designed and synthesized as antimitotic antitumor agents. All compounds showed cytotoxic effects (log GI50 < or = -4.0; log drug molar concentration required to cause 50% inhibition) against the growth of a variety of human tumor cell lines, including those derived from solid tumors such as non-small cell lung, colon, central nervous system, ovary, prostate, and breast cancers, when evaluated in the National Cancer Institute's 60 human tumor cell line in vitro screen. The most potent compound (26) demonstrated strong cytotoxic effects with GI50 values in the nanomolar or subnanomolar range in almost all the tumor cell lines. Compound 26 was also a potent inhibitor of tubulin polymerization and radiolabeled colchicine binding to tubulin, with activity comparable to those of the potent antimitotic natural products colchicine, podophyllotoxin, and combretastatin A-4.

2-Methoxyestradiol, an endogenous mammalian metabolite, inhibits tubulin polymerization by interacting at the colchicine site

A metabolite of estradiol, 2-methoxyestradiol (2ME), inhibits angiogenesis in the chicken embryo chorioallantoic membrane assay. Since 2ME causes mitotic perturbations, we examined its interactions with tubulin. In our standard 1.0 M glutamate system (plus 1.0 mM MgCl2 at 37 degrees C), superstoichiometric concentrations (relative to tubulin) of 2ME inhibited the nucleation and propagation phases of tubulin assembly but did not affect the reaction extent. Although polymer formed in the presence of 2ME was more cold-stable than control polymer, morphology was little changed. Under suboptimal reaction conditions (0.8 M glutamate/no MgCl2 at 26 degrees C), substoichiometric 2ME totally inhibited polymerization. No other estrogenic compound was as effective as 2ME as an inhibitor of polymerization or of the binding of colchicine to tubulin. Inhibition of colchicine binding was competitive (Ki, 22 microM). Thus, a mammalian metabolite of estradiol binds to the colchicine site of tubulin and, depending on reaction conditions, either inhibits assembly or seems to be incorporated into a polymer with altered stability properties.

Antitumor agents. 150. 2',3',4',5',5,6,7-substituted 2-phenyl-4-quinolones and related compounds: their synthesis, cytotoxicity, and inhibition of tubulin polymerization

As part of our continuing search for potential anticancer drug candidates in the 2-phenyl-4-quinolone series, we have synthesized a series of 6,7-methylenedioxy-substituted and unsubstituted 2-phenyl-4-quinolones, as well as related compounds. Their in vitro inhibition of human tumor cell lines and tubulin polymerization is reported. In general, a good correlation was found between cytotoxicity and inhibition of tubulin polymerization. Compounds 7, 9, 13, 16, 22, 23, 36, and 37 showed potent inhibitory effects in both assays. All rigid analogs (47-49) and trimethoxy-substituted compounds showed little or no activity. Substitution at the 4'-position also resulted in compounds with little or no activity, except for hydroxyl or methyl groups at this position. Further investigation is underway to determine if substitution at the 3'-position will result in compounds with increased activity.

Calcium supplementation inhibits the expression of parathyroid hypertensive factor in DOCA-salt hypertensive rats

To elucidate the antihypertensive mechanism of oral calcium supplementation in salt-dependent hypertension, we investigated the hypertensive activity of plasma from DOCA-salt hypertensive rats fed with (DS-Ca) or without (DS) a high calcium diet. Four weeks of calcium supplementation (4% CaCl2) attenuated the blood pressure increase in DS rats. Intravenous bolus injection of dialyzed plasma (1.0-kDa cutoff) from DS rats to normotensive rats resulted in a sustained elevation in blood pressure, whereas that from DS-Ca rats did not. As the endothelin concentration was not different between the two groups, the circulating hypertensive substance in DS rats may be identical to parathyroid hypertensive factor (PHF) and the inhibition of its expression by calcium may be involved in the hypotensive mechanism of high calcium diets in salt-dependent hypertension.

Two new cytotoxic chalcones from Calythropsis aurea

The crude extract of Calythropsis aurea (Myrtaceae) produced a pattern of differential cytotoxicity in the NCI 60 cell line assay which was similar to those of known tubulin-interactive compounds. Cytotoxicity-guided fractionation led to the isolation of two new chalcones, calythropsin [1] and dihydrocalythropsin [2], which were responsible for the activity. Calythropsin was demonstrated to have a weak effect on mitosis, and presumably also on tubulin polymerization.

Synthesis and evaluation of a series of benzylaniline hydrochlorides as potential cytotoxic and antimitotic agents acting by inhibition of tubulin polymerization

Although certain substituted cis-stilbenes have displayed potent tubulin polymerization inhibitory activity and significant cytotoxicities in cancer cell cultures, these compounds have limited aqueous solubility and are therefore difficult to formulate for in vivo evaluation. A series of water-soluble N-(3,4,5-trimethoxybenzyl)aniline salts has therefore been synthesized in which the olefinic bridge of the stilbenes is replaced by an aminomethylene hydrochloride moiety. A relationship was found between the size of the substituent in the 4-position of the aniline ring and both antitubulin activity and cytotoxicity, such that the smaller the substituent, the greater the potency. The most promising of the newly synthesized compounds was 4-methyl-N-(3,4,5-trimethoxybenzyl)aniline hydrochloride, with an IC50 value of 3.5 microM for inhibition of tubulin polymerization and cytotoxicity for a wide variety of cancer cell lines. The cytotoxicities of the benzylaniline hydrochlorides correlated remarkably well with their antitubulin activities.

Structure of the channel catfish (Ictalurus punctatus) growth hormone gene and its evolutionary implications

A DNA fragment of 1.6 kilo base pairs (kb), encoding part of the channel catfish (Ictalurus punctatus) growth hormone (GH) gene, was generated by the polymerase chain reaction (PCR) using 2 degenerate synthetic oligonucleotides (30 and 33 mer) derived from the N- and C-terminal amino acid sequences of the catfish GH polypeptide as amplification primers and with catfish genomic DNA as a template. This DNA fragment was used as a probe for the isolation of a catfish GH gene from a genomic library constructed in a lambda phage cloning vector, lambda Dash II. Three positive clones were isolated, and their complete nucleotide sequences were determined. Nucleotide sequences from clones 1 and 3 were identical, whereas clone 2 had 2 base substitutions. The gene spans approximately 3 kb and is comprised of 5 exons and 4 introns. The initiation codon, the termination codon, and the canonical polyadenylation sequence were identified. The amino acid sequence deduced from the predicted coding region of the gene is in agreement with that of the native GH polypeptide sequence. A sequence (TATAAAA) matching the TATA box consensus sequence was located at nucleotide positions -30 to -23. Furthermore, 2 sequences corresponding to the mammalian Pit-1/GHF-1 binding sites (consensus sequence TT[AA]TATNCAT) were identified in the 5' flanking region starting at positions -113 and -134. Another sequence (GTACCAGTGA) conserved among the GH genes of the channel catfish and other known animal species was also identified at position -220. The biological functions of this sequence remain to be determined.(ABSTRACT TRUNCATED AT 250 WORDS)

Distribution of 64Cu in Saccharomyces cerevisiae: cellular locale and metabolism

The metabolism of copper in the yeast Saccharomyces cerevisiae has been studied with respect to the distribution and stability to exchange of newly arrived 64Cu. Cells pre-incubated with 10 microM-Cu2+ accumulated 64Cu into two pools distinguishable by cellular locale and lability to exchange with extracellular cold copper. One pool was non-exchangeable and was localized to protoplasts. Size-exclusion chromatography of a soluble cell (protoplast) extract showed that this 64Cu was associated with up to four species. Two were identified as copper metallothionein and Cu,Zn superoxide dismutase based on comparisons of chromatograms derived from strains in which the genes for these two proteins had been deleted. A third species was identified as copper-glutathione based on chromatographic and biochemical assays. A second pool was exchangeable and was localized to the cell wall. In contrast to its rapid copper-stimulated exchange (t1/2 approximately 1 min), this pool exhibited only slow efflux (10% 64Cu loss per 60 min). Zn2+ did not stimulate the loss of 64Cu from this pool indicating that it was selective for copper. This pool was released into the supernatant upon protoplast formation and was found in the cell wall debris obtained when cells were mechanically disrupted. This 64Cu eluted in the void volume (peak Pv) of the column used to size-fractionate copper-binding species. The metal in Pv was exchangeable in vivo and in vitro. However, the corresponding chromatographic fraction obtained from copper-naive cells when labelled in vitro could bind less than 20% of the 64Cu bound to it in vivo indicating that the deposition of copper in this pool was primarily cell-dependent. In fact, this deposition was shown to be dependent on the cellular reduction of medium sulphate or sulphite to the level of sulphide, or on the addition of sulphide to the 64Cu uptake buffer. 64Cu in the non-exchangeable protoplast pool was not mobilized by cellular sulphide generation, indicating that cellular sulphide generation did not causally lead to the partitioning of 64Cu to the cell wall pool. The data indicate that the appearance of copper sulphide(s) on the cell wall in S. cerevisiae is gratuitous and does not represent a sulphide-based mechanism of copper resistance in this yeast.

Distribution of 64Cu in Saccharomyces cerevisiae: kinetic analyses of partitioning

The cell association of copper in the yeast Saccharomyces cerevisiae can involve both binding to the cell wall and the accumulation of copper within the cell. The former process requires the concurrent generation of H2S by the cell via the reduction of sulphate. The contributions of each of these processes to the uptake of 64Cu by wild type and met3-containing (ATP sulphurylase-deficient) strains have been kinetically dissected. The Michaelis constant for uptake (4 microM) is independent of the type of cell association which is occurring, suggesting, although not requiring, that both processes are associated with a common kinetic intermediate. The time dependence of the cell-association of 64Cu also suggests the presence of this intermediate pool of bound copper. The Vmax for uptake includes a constant contribution from accumulation of 64Cu within the plasmalemma [0.1 nmol min-1 (mg protein)-1] plus that fraction of the 64Cu within the intermediate pool which diffuses away and is trapped on the cell wall as a metal sulphide. This latter contribution to Vmax can be two- to three-times greater than the intracellular uptake depending on the amount and type of sulphur supplementation provided in the 64Cu2+ uptake buffer. Both processes are energy-dependent although the sulphide-dependent periplasmic accumulation is somewhat more sensitive to metabolic inhibition. This can be attributed to the ATP required for the activation of sulphate prior to its reduction to the level of sulphite and then sulphide. Periplasmic 64Cu accumulation is strongly inhibited by Zn2+ and Ni2+. This inhibition is due to competition for cell-generated sulphide; in the presence of 65Zn2+, the decrease in 64Cu bound is quantitatively related to the amount of 65Zn which becomes cell-associated. In contrast, intracellular 64Cu uptake is not inhibited by these two metals (at 50 microM) showing that the copper translocation pathway is metal-specific. These observations suggest a model for the way newly arrived copper is handled at the cell membrane and is partitioned for intracellular uptake.

Antitumor agents. 141. Synthesis and biological evaluation of novel thiocolchicine analogs: N-acyl-, N-aroyl-, and N-(substituted benzyl)deacetylthiocolchicines as potent cytotoxic and antimitotic compounds

Three series of novel thiocolchicine analogs, N-acyl-, N-aroyl-, and N-(substituted benzyl)-deacetylthiocolchicinoids, have been synthesized and evaluated for their cytotoxicity against various tumor cell lines, especially solid tumor cell lines, and for their inhibitory effects on tubulin polymerization in vitro. Most of these compounds showed strong inhibitory effects on tubulin polymerization comparable to that obtained with thiocolchicine and greater than that obtained with colchicine. Only compounds with a long side chain at the C(7) position, such as 22-24, did not inhibit tubulin polymerization. Several of the active N-aroyldeacetylthiocolchicine analogs had positive optical rotations, in contrast to the negative optical rotation observed with most colchicinoids. This property might be attributed to a reversal of biaryl configuration from the normal aS to aR. Therefore, the N-aroyl analogs were further evaluated by circular dichroism, which readily distinguishes between the aS and aR biaryl configurations. This latter technique demonstrated that the active N-aroyl analogs do have an aS configuration despite their positive optical rotations. However, comparison of 1H NMR and UV spectral data of N-(substituted benzyl)-deacetylthiocolchicines with those of corresponding N-aroyldeacetylthiocolchicines suggested a different biaryl dihedral angle [even though these compounds have the same aS biaryl configuration]. The similar tubulin binding properties of these compounds suggest that a biaryl dihedral angle of 53 degrees is not essential for colchicinoid-tubulin interaction. The increased cytotoxicity of N-(substituted benzyl)deacetylthiocolchicines compared to the N-aroyldeacetylthiocolchicines may be attributed to different lipophilicity, drug uptake, or drug metabolism in the tumor cells. The side chain at the C(7) position affects inhibition of tubulin polymerization and the cytotoxic activity of colchicinoids as a function of its size and its contribution to lipophilicity.

Synthesis and cytotoxicity of 1,6,7,8-substituted 2-(4'-substituted phenyl)-4-quinolones and related compounds: identification as antimitotic agents interacting with tubulin

A series of 1,6,7,8-substituted 2-(4'-substituted phenyl)-4-quinolones and related compounds have been synthesized and evaluated as cytotoxic compounds and as antimitotic agents interacting with tubulin. The 2-phenyl-4-quinolones (22-30) with substituents (e.g. F, Cl, and OCH3) at C-6, C-7, and C-8 show, in general, potent cytotoxicity against human lung carcinoma (A-549), ileocecal carcinoma (HCT-8), melanoma (RPMI-7951), and epidermoid carcinoma of the nasopharynx (KB) and two murine leukemia lines (P-388 and L1210). Introduction of alkyl groups at N-1 or C-4 oxygen led to inactive compounds (35-43 and 50). In addition, compounds 24, 26, and 27 were evaluated in the National Cancer Institute's 60 human tumor cell line in vitro screen. These compounds demonstrated the most marked effects in the screen on two colon carcinoma cell lines (COLO-205 and KM-20L2) and on a central nervous system tumor cell line (SF-539) with compound 26 the most potent of the three agents. Compounds 24, 26, and 27 were potent inhibitors of tubulin polymerization, with activity nearly comparable to that of the potent antimitotic natural products colchicine, podophyllotoxin, and combretastatin A-4. The three agents also inhibited the binding of radiolabeled colchicine to tubulin, but this inhibition was less potent than that obtained with the natural products.

Paragonimus calcified ova mimicking left renal staghorn stone

We report on a 49-year-old woman with clusters of Paragonimus calcified ova unusually located in the left retroperitoneal space and renal capsule mimicking a left renal staghorn stone. The diagnosis and treatment are discussed. We also reviewed the endemic condition of paragonimiasis in Taiwan.

Antitumor agents. 139. Synthesis and biological evaluation of thiocolchicine analogs 5,6-dihydro-6(S)-(acyloxy)- and 5,6-dihydro-6(S)-[(aroyloxy)methyl]-1,2,3-trimethoxy-9-(methylthio)-8H- cyclohepta[a]naphthalen-8-ones as novel cytotoxic and antimitotic agents

A series of novel thiocolchicine analogs, 5,6-dihydro-6(S)-(acyloxy)-and 5,6-dihydro-6(S)-[(aroyloxy)-methyl]-1,2,3-trimethoxy-9-(methylthi o)-8H- cyclohepta[a]naphthalen-8-ones, possessing a six-membered ring B, have been synthesized and evaluated for their cytotoxicity against various tumor cell lines, including solid tumor cell lines, and for their interaction with tubulin. The configuration of the parent alcohol (compound 5) was established unequivocally as (aR,6S) by X-ray crystallographic analysis. The side chain at the C(6) position is in a pseudoaxial orientation. The optical properties and 1H NMR data indicated that these compounds have the same conformations in solution as in the solid state. Biological results showed that compounds (5, 6, 14, 15, 17, and 18) bearing a small side chain at C(6) demonstrate high potency in inhibiting tubulin polymerization and binding of radiolabeled colchicine to tubulin. The most cytotoxic compounds were 14, 15, 17, and 18, with good activity against several solid tumor cell lines. To explain the strong antitubulin activity of compound 5 (with an aR configured biaryl system in contrast to the aS configuration previously described for colchicinoids, allocolchicinoids, and steganacin) we speculate that a rapid atropisomerism equilibrium must exist for 5 and its active derivatives. This equilibrium would yield adequate amounts of aS-configured conformers that interact, strongly with tubulin. Since the optically inactive 18 is also a potent inhibitor of tubulin, the configuration of the side chain of these six-membered ring B analogs cannot be essential for their binding to tubulin. Instead we propose that the size of ring B and of its side chain play important roles in tubulin binding activity by affecting the rotation of the rings A and C along their linking C-C bond axis.

Expression and inheritance of RSVLTR-rtGH1 complementary DNA in the transgenic common carp, Cyprinus carpio

Transgenic common carp, Cyprinus carpio, possessing the long terminal repeat (LTR) sequence of avian Rous sarcoma virus (RSV) fused to the rainbow trout (rt) growth hormone (GH1) complementary DNA (cDNA) were produced by microinjection. Initial studies showed that the transgenic common carp transmitted the foreign DNA to a significant fraction of their progeny in three of four crosses of transgenic males with control females. These progeny grew 20 to 40% faster than their nontransgenic full siblings. In this study, additional experiments were conducted to evaluate inheritance and expression of the foreign GH gene in transgenic common carp, and the growth performance of these transgenic fish. Four P1 (parental generation produced by microinjection) x nontransgenic controls, four P1 x P1, and one P1 x F1 matings of transgenic carp containing RSVLTR-rtGH1 cDNA were made. The percentages of transgenic progeny resulting from these matings were: 0, 32, 42, 100 (4 progeny only), 21, 21, 31, 30, and 23%, respectively. All crosses except 1 siblot (control x P1) exhibited progeny ratios below the expected 50 or 75% transgenic. These results indicate that most of these transgenic P1 had the foreign gene in their germ line but were mosaics, and at least one transgenic individual did not have the RSVLTR-rtGH1 cDNA in the gonadal tissue. Both P1 and F1 transgenic fish produce trout growth hormone mRNA and polypeptide as determined by reverse transcription polymerase chain reaction amplification, RNA dot-blot hybridization, and radio-immunobinding assay. Growth response by families of F1 transgenic fish to the addition of rtGH1 cDNA varied widely.(ABSTRACT TRUNCATED AT 250 WORDS)