A novel cis-acting element controlling the rat CYP2D5 gene and requiring cooperativity between C/EBP beta and an Sp1 factor

The rat CYP2D5 gene encodes a cytochrome P450 and is expressed in liver cells. Its expression commences a few days after birth, and maximal mRNA levels are achieved when animals reach puberty. Transfection and DNA binding studies were performed to investigate the mechanism controlling developmentally programmed, liver-specific expression of CYP2D5. Transfection studies using a series of CYP2D5 upstream DNA chloramphenicol acetyltransferase gene fusion constructs identified a segment of DNA between nucleotides -55 and -156 that conferred transcriptional activity in HepG2 cells. Activity was markedly increased by cotransfection with a vector expressing C/EBP beta but was unaffected by vectors producing other liver-enriched transcription factors (C/EBP alpha, HNF-1 alpha, and DBP). DNase I footprinting revealed a region protected by both HepG2 and liver cell nuclear extracts between nucleotides -83 and -112. This region displayed some sequence similarity to the Sp1 consensus sequence and was able to bind the Sp1 protein, as assessed by a gel mobility shift assay. The role of Sp1 in CYP2D5 transcription was confirmed by trans activation of the 2D5-CAT construct in Drosophila melanogaster cells by using an Sp1 expression vector. C/EBP beta alone was unable to directly bind the -83 to -112 region of the promoter but was able to produce a ternary complex when combined with HepG2 nuclear extracts or recombinant human Sp1. C/EBP alpha was unable to substitute for C/EBP beta in forming this ternary complex. A poor C/EBP binding site is present adjacent to the Sp1 site, and mutagenesis of this site abolished formation of the ternary complex with the CYP2D5 regulatory region. These result establish that two transcription factors can work in conjunction, possibly by protein-protein interaction, to activate the CYP2D5 gene.

Antitumor agents--CLI. Bis(helenalinyl)glutarate and bis(isoalantodiol-B)glutarate, potent inhibitors of human DNA topoisomerase II

Evaluation of a number of cytotoxic antitumor sesquiterpene lactones and their derivatives has led to the discovery of bis(helenalinyl)glutarate (4) and bis(isoalantodiol-B)glutarate (10) as potent inhibitors of human-derived topoisomerase II. Unlike etoposide, which inhibits by preventing the DNA rejoining process, compounds 4 and 10 inhibit topoisomerase II without causing DNA breakage. The structure-activity relationships of 4, 10, and related compounds are discussed.

[Injection of 5-fluorouracil in the treatment of tubal pregnancy through salpingo-catheter under hysteroscopy]

Seventeen women with unruptured tubal pregnancy were given 5-FU through salpingo-catheter under hysteroscopy. In one case the injection failed because the tube opening could not be found. The success rate of salpingo-catheterization was 94.12% (16/17). The cure rate for the tubal pregnancies was 88.24% (15/17). 12 cases received injection once and 3 cases twice. The dose of 5-FU per injection was 250 mg in 10 ml solution. Serum beta-hCG test became negative in 7 to 14 days after the treatment, and signs and symptoms disappeared. Salpingography were done in 8 cases after 2 to 3 months, and all the diseased tubes were found patient. There was little side effects due to this treatment, which is more effective, convenient and less traumatic than injecting 5-FU to the affected site through laparoscopy or systemic administration. It may turn out to be an effective, simple, safe and acceptable new method for treating early tubal pregnancy.

Total pelvic exenteration for locally advanced rectal carcinoma

Total pelvic exenteration was performed in 31 patients (30 males and 1 female) who had rectal cancers involving adjoining pelvic structures. Twenty-nine patients had primary tumors and two had recurrent diseases after previous abdominoperineal resection. Preoperative irradiation was used in nine patients with fixed tumors. When performing the surgical procedure, we also actively employed lateral node dissection to make the operation more radical. Three patients (one with primary tumor and two with recurrent) underwent the exenteration with partial sacrectomy because of the sacral involvement and they all died of local failure within 15 months. The overall 5-year survival rate was 52 percent for all patients and 56 percent for those who had primary tumors. The results suggest that total pelvic exenteration with lateral node dissection should be performed for locally advanced rectal cancer if the tumor is not completely fixed to the pelvic wall and preoperative irradiation should be used to convert a fixed tumor to a resectable one.

[Studies on the isolation of endogenous sleep factors from Tupaia Belangeri Chinensis (TBC) after sleep deprivation]

The present study was undertaken to explore endogenous sleep factors isolated from 48-72 h sleep deprived (SD) male Tupaia belangeri chinensis (TBC). Only drink ad libitum (10% glucose) was available within 24 h before collection of urine. Controlled "clean" urinary samples were pooled and stored at 20 C. Fraction I-V from the urine were determined after ultrafiltration and Sephadex-G15. Amino-acid analysis of each fraction was automatically done by a 835 Amino-acid Analyzer, respectively. Bioassay was performed in 40 adult rabbits weighing 2.5-3.5 kg of either sex. Experiments were undertaken via the mesodiencephalic intraventricular infusion. Results show that S2C (Fraction-III) (50 micrograms/rabbit, i.c.v.) exhibited significant delta-enhancing effect compared to the controls. Further purification was done with Sephadex G-25 and Sephadex LH-20. The more purified S4B (50 micrograms/rabbit, i.c.v.) also exhibited significant delta-enhancing effect compared to the controls. The amino-acid analysis of Fraction-III revealed that the compositional contents of S2C and S4B are different from what have been known with Factor S, DSIP and SPS.

[Results of surgical treatment of recurrent retroperitoneal soft tissue sarcomas]

Thirty patients with locally recurrent retroperitoneal soft tissue sarcomas, whose primary tumors had been previously resected, were surgically treated. Complete resection was achieved in 18 patients (60%), of which 6 underwent en bloc resection of adjacent organs involved by the tumor. The overall 3- and 5-year survival rate for all patients was 39% and 14%, respectively. Survival at 3 and 5 years was 49% and 24% respectively for those undergoing complete resection, compared to 25% and 0% respectively for those undergoing partial resection or biopsy only (P < 0.005). An aggressive surgery aimed at complete resection. in treating recurrent retroperitoneal soft tissue sarcomas is strongly recommended. Prognostic value and clinical significance of factors such as disease-free interval, tumor size, and histologic type were discussed.

Antiplatelet structure-activity relationship of tetramethylpyrazine

Tetramethylpyrazine (TMPZ) is an active component of certain plants previously found to have inhibitory effects on platelet function using both in vivo and in vitro assays(1). In this study, we examined the antiplatelet activity of structural analogues of TMPZ in order to assess structural requirements for activity. Functional requirements included nitrogen substitutions on the aromatic ring; substitutions could be either heterocyclic or ring substituted in the meta position. Enhanced antiplatelet activity was associated with increasing the number of alkyl groups on the pyrazine ring as well as increasing the length of unbranched alkyl side chains. Increased inhibition of platelet aggregation correlated with increased lipophilicity of the compounds tested. In addition, several compounds were identified which deserve further pharmacological investigation.

Effects of selenium supplement on the de novo biosynthesis of glycerolipids in the isolated rat heart

The effect of selenium supplement on glycerolipid biosynthesis in the isolated rat heart was investigated. Selenium was administered to the rat by intraperitoneal injection of 4.33 mumol/kg per day for 3 consecutive days. Animals administered with an equal volume of saline were used as controls. Hearts from both animal groups were perfused in Krebs-Henseleit buffer containing labelled glycerol. Subsequent to perfusion, the radioactivity associated with each glycerolipid group was determined. Selenium supplement caused elevations in the labelling of phosphatidic acid and phosphatidylcholine but not in other phospholipids, diacylglycerol or triacylglycerol. The mechanisms for the enhancement of labelling into phosphatidic acid and phosphatidylcholine were examined. The activity of the enzymes responsible for the synthesis of phosphatidic acid in the rat heart was not changed by selenium supplement. However, a 51% increase in the acyl-CoA level was detected which might account for the elevated labelling of phosphatidic acid in the selenium supplemented animal. The 2-fold increase in the activity of CDPcholine:diacylglycerol cholinephosphotransferase might also account for the increase in the labelling of phosphatidylcholine in the heart of the selenium-supplemented rat. It is clear from this study that selenium plays a regulatory role in the control of cellular lipid metabolism.

Tissue oxygenation in hypovolemic shock

Bowel mucosal ischemia may be related to the development of systemic sepsis. Traditional indices of oxygen metabolism are flow-weighted averages which do not reflect tissue-specific oxygen concentration. We undertook this study to examine the relationship between systemic oxygen delivery (DO2) and tissue oxygen tension (TPO2) in hypovolemic shock. A modified Wiggers model was used to produce hypotension in five swine. TPO2 was measured continuously with fluorescence-quenching 1-mm probes placed in the submucosa of the terminal ileum and subcutaneously in an axillary fold. Shock was maintained for 1 hr, followed by resuscitation. Cardiac output, systemic and pulmonary arterial pressures, and arterial and mixed venous blood gases were measured every 15 min. Data were analyzed by nonparametric ANOVA and rank coefficients, with logarithmic curve fitting and linear regression. DO2 decreased with phlebotomy (P < 0.003) as did skin TPO2 (P < 0.001) and bowel TPO2 (P < 0.0004). Skin and bowel TPO2 varied with DO2 and each other (P < 0.05). TPO2 remained low throughout the shock period and returned to or exceeded baseline levels with resuscitation (P < 0.05). The following were concluded: (1) Hypovolemic shock produces a significant and rapid decrease in subcutaneous and bowel TPO2 with concomitant change in DO2. (2) The degree of bowel ischemia, clinically inaccessible for quantitation, is paralleled by subcutaneous TPO2. (3) TPO2 provides information about oxygen availability in shock and resuscitation not available from traditional parameters of oxygen transport.

Helium insufflation for laparoscopic operation

Laparoscopic surgical procedures are becoming simultaneously more commonplace and complex. However, carbon dioxide (CO2) pneumoperitoneum required for these procedures causes a respiratory acidosis. We undertook this study to determine if an alternate insufflating gas, such as helium, prevents this sequelae. Twenty patients undergoing elective laparoscopic cholecystectomy were randomized to receive either CO2 or helium insufflation. Intraoperative parameters, including arterial CO2 (PaCO2), end-tidal CO2, pH, bicarbonate (HCO3-), cardiac output and blood pressure were obtained before, during and at the conclusion of pneumoperitoneum. Effects of the two gases on these variables were compared. The average CO2 rose significantly from 35.7 +/- 1.0 to 50.4 +/- 3.2 (p < 0.0001), while pH decreased from 7.434 +/- 0.014 to 7.286 +/- 0.018 (p < 0.0001) in those who received CO2. No change in PaCO2 was observed in those who received He, although a small decrease in pH from 7.428 +/- 0.011 to 7.392 +/- 0.012 (p < 0.05) was observed. HCO3- decreased slightly in both groups. Increases in blood pressure and pulse rate were independent of the gas received. The cardiac output did not change. Helium insufflation for laparoscopic cholecystectomy does not produce the respiratory acidosis caused by CO2 and, therefore, merits further investigation for use, particularly in patients with underlying respiratory disease.

Comparative cardiopulmonary effects of carbon dioxide versus helium pneumoperitoneum

The recent surge in enthusiasm for laparoscopic surgery has created concern that abdominal insufflation with carbon dioxide produces a respiratory acidosis. This may be because of both transperitoneal gas absorption and impaired ventilation with increased dead space from elevated intraabdominal pressure. To examine the relative contributions of these factors, we developed an animal model of surgical pneumoperitoneum that evaluated the cardiorespiratory effects of abdominal insufflation. Helium was chosen as an alternative to CO2 because it is both chemically and biologically inert. Carbon dioxide absorption during CO2 pneumoperitoneum caused arterial PCO2 to increase from 41.3 +/- 3.0 to a maximum of 58.3 +/- 4.0 mm Hg, with pH descending from 7.46 +/- 0.02 to a nadir of 7.31 +/- 0.02 (p < 0.05). Pulmonary artery pressure increased to twice baseline levels during CO2 insufflation (p < 0.05). Helium did not cause hypercarbia, acidemia, or pulmonary hypertension despite insufflation under identical conditions. These results indicate that transperitoneal absorption of CO2, not increased dead space, is responsible for the respiratory acidosis observed. Helium merits further study as an agent to induce pneumoperitoneum, especially when concerns of underlying acidosis or impaired gas exchange are present.

In vitro and in vivo evaluations of Chinese traditional (kampo) medicines as anticalculus agents in the rat

Inhibitory effects of two Chinese traditional (Kampo) medicines, Shigyaku-san and Shikunshi-to, on the in vitro formation of calcium phosphate precipitates and the in vivo deposition of supragingival dental calculus were studied. Both had inhibitory effects on hydroxyapatite transformation and induction; effects of Shigyaku-san and Shikunshi-to were 1/100 and 1/400 of that of 1-hydroxyethylidene-1,1-bisphosphonate (HEBP). When used topically (in drinking water) for 4 weeks, 20-40 mg/ml of Shigyaku-san or Shikunshi-to reduced the formation of dental calculus by 40-60%, while 0.03% (w/v) HEBP decreased it by 70-98%. However, when these drugs were given by gastric intubation for 2 weeks, they were all ineffective, suggesting that the observed anticalculus effects were of topical rather than of systemic origin.

Inhibition of the formation of oral calcium phosphate precipitates: beneficial effects of Chinese traditional (kampo) medicines

Screening tests on the formation of calcium phosphate precipitates using 23 different kinds of Kampo medicines (Chinese traditional medicines) were carried out, at concentrations where the effects of chelation are not significant. Four of them, Hochu-ekki-to (TJ-41), Kyuki-kyogai-to (TJ-77), Oren-to (TJ-120) and Inchin-ko-to (TJ-135) showed an inhibitory effect on the formation of amorphous calcium phosphate (ACP). The inhibitory effect on the induction time and the rate of transformation to hydroxyapatite (HAP) varied greatly among the 23 Kampo medicines. We classified them according to their effects on increasing the induction time and/or decreasing the rate of HAP transformation. Ethane-1-hydroxy-1, 1-diphosphonate (EHDP) was used as the standard. This compound is a common toothpaste additive which decreases dental calculus formation. Two of the 23 Kampo medicines showed little or no inhibition either on the induction time or on the rate of HAP transformation. Twelve of them reduced the rate of HAP transformation by 20-40% and with 1.9- to 4.0-fold increases in the induction time. The remaining nine showed even greater activity. Keishi-ninjin-to (TJ-82), Dai-kenchu-to (TJ-100), Toki-to (TJ-102), Rikko-san (TJ-110) and San'o-shashin-to (TJ-113) showed the same inhibitory effect as EHDP. Shigyaku-san (TJ-35;5.2-fold), Dai-kanzo-to (TJ-84;4.9-fold), Oren-gedoku-to (TJ-15;12.7-fold) and Inchin-ko-to (TJ-135;9.5-fold) had a greater effect on the increase of induction time than EHDP and reduced the rate of HAP transformation by 50-60%. These results suggest that these nine kinds of Kampo medicines may have potential as anticalculus agents in toothpastes and mouthwashes.

Effectors of hypercarbia during experimental pneumoperitoneum

Hypercarbia occurs during laparoscopy with carbon dioxide (CO2) insufflation. This may be due to increased ventilatory dead space after expansion of the peritoneal cavity with impairment of diaphragmatic excursion, or to increased absorption of CO2 from the peritoneum. To separate these effects, the authors examined the consequences of different insufflating gases and of diminished tissue perfusion on hypercarbia and dead space during pneumoperitoneum. Helium was chosen as an alternate insufflating gas because it is both inert and minimally absorbed. Eight swine (18 to 20 kg) were anesthetized, paralyzed, and mechanically ventilated at constant minute volume. Pneumoperitoneum with helium was maintained at 15 mm Hg for 45 minutes. After desufflation and stabilization for 1 hour, pneumoperitoneum was repeated with CO2. The sequence was again repeated after hemorrhagic shock to constant mean arterial pressure of 50 mm Hg. Data was analyzed by analysis of variance; significance levels are P < 0.01 unless otherwise listed. Arterial PCO2 increased significantly with CO2 insufflation within 15 minutes in normotensive animals and within 30 minutes during hypotension. Arterial pH decrease with CO2 pneumoperitoneum was significant in both groups at 30 minutes. Mixed venous PCO2 also increased with CO2 pneumoperitoneum within 30 minutes. Hypotension did not alter these changes. No significant changes were seen with helium pneumoperitoneum. Neither helium nor CO2 pneumoperitoneum significantly altered dead space. The authors make the following conclusions: 1) Absorption of CO2 from the abdomen during CO2 pneumoperitoneum produces respiratory acidosis, which is not seen with helium insufflation; 2) Pneumoperitoneum does not significantly increase dead space with either gas; 3) Transperitoneal absorption of CO2 is only partly related to perfusion because significant hypercarbia occurs during hemorrhagic shock.

Accuracy of capnography in nonintubated surgical patients

Previous studies have reported mixed results when correlating etCO2 and PaCO2 in mechanically ventilated patients with underlying respiratory disease. However, the utility and accuracy of capnography in nonintubated patients, without chronic pulmonary disease, has received little attention. We studied 25 nonintubated surgical patients to (1) examine the correlation between PaCO2 and etCO2 and (2) describe the relationship between dead space (VD/VT), venous admixture and P(a-et)CO2. End tidal CO2 was lower than PaCO2 by an average of 3.6 mm Hg. Regression analysis found a close correlation between dead space and the P(a-et)CO2 gradient (r = 0.77, p < 0.001), while venous admixture was of lesser importance (r = 0.47). Capnographic estimates of PaCO2 can be useful for continuously monitoring the respiratory status of nonintubated spontaneously breathing patients weaned from mechanical ventilation. This may be of particular value in trauma victims and in selected surgical patients without underlying respiratory disease in whom other injuries require continued critical care.

Relationship between cardiovascular functions and ionic hypocalcemia induced by citrate infusion in anhepatic swines: CaCl2 therapy in severe ionic hypocalcemia

Baseline and serial values of serum [Ca++], [K+], [Na+], arterial blood gas tensions, acid-base status, temperature and hemodynamic functions were measured during infusion of citrate-phosphate-dextrose (CPD) solution (0.35 ml.kg-1 x min-1) in anhepatic pigs of three randomized groups. Thirteen pigs (group I) continued to receive intravenous infusion of CPD solution until cardiac arrest. When mean arterial pressure (MAP) decreased to about 50 mmHg (group II, n = 7), or 40 mmHg (group III, n = 7) infusion of CPD solution was discontinued, and pigs received CaCl2 (20 mg/kg) intravenously. Serial (1, 4, 8, and 12 min after CaCl2 administration) values of all the above variables and serum citrate at baseline and lowest [Ca++] were measured. After hepatectomy and venovenous bypass, cardiac output (CO) decreased 30%. When ionic hypocalcemia was above 0.7 mM, there was no significant change of cardiovascular functions. When [Ca++] was between 0.34-0.7 mM, there were linear relationships between [Ca++] and CO, systemic vascular resistance (SVR) and MAP, respectively. When [Ca++] was below 0.34 mM, cardiovascular functions decreased abruptly, and the pigs died at [Ca++] of 0.26 +/- 0.06 mM. When [Ca++] decreased to 0.36 +/- 0.06 mM and MAP to 50 +/- 4 mmHg, most hemodynamic functions could be reversed by calcium therapy. However, when [Ca++] decreased to 0.33 +/- 0.05 mM and MAP to 40 +/- 2 mmHg, hemodynamic functions could not be reversed by calcium therapy alone.

Antitumor agents. 134. New shiraiachrome-A- and calphostin-C-related perylene derivatives as cytotoxic and antiviral agents and inhibitors of protein kinase C

Shiraiachrome-A and -B have been isolated from the mycelium of the Chinese bamboo fungus Shiraia bambusicola as the cytotoxic principles. A series of new perylene derivatives (7-27) related to Shiraiachrome-A and -B as well as Calphostin-C have been synthesized and evaluated for their cytotoxicity, antiviral activity, and inhibitory activity against protein kinase C. The results indicated that 11 and 12 are potent cytotoxic agents against HCT-8, RPMI-7951, and TE-671 solid tumor cells, whereas 24 and 26 demonstrated strong antiviral activity against HSV-1 and HSV-2. Compound 10 is an inhibitor of protein kinase C.

Effects of body position and age on membrane diffusing capacity and pulmonary capillary blood volume

The effects of body position and age on the membrane diffusing capacity (Dm), pulmonary capillary blood volume (Vc), and the single breath carbon monoxide diffusing capacity (Dco) were evaluated in the erect (sitting) and supine positions in 16 normal young men (under 40 years old, younger group) and in 13 older men (over 40 years old, older group). Dm and Vc were estimated by several measurements of the Dco at increasing alveolar oxygen tension (PAO2). The results showed that Dco, Dm, Vc, and Kco (Dco corrected by alveolar volume) decreased with age in both positions. The differences in Dco, VC, and Kco between the two positions (supine minus the erect position) also decreased with age. The mechanisms of the increases in Dco in the supine position remain to be explained but may be due to a change in pulmonary capillary shape from an elliptical (erect position) to a circular configuration (supine position) since Vc increased more than Dm on assuming the supine position. The findings may be of clinical importance since many physicians have attempted to utilize a reduction in the positional change in Dco as a potential marker of disease.

Antitumor agents. 123. Synthesis and human DNA topoisomerase II inhibitory activity of 2'-chloro derivatives of etoposide and 4 beta-(arylamino)-4'-O-demethylpodophyllotoxins

The 2'-chloro derivatives of etoposide and 4 beta-(arylamino)-4'-O-demethylpodophyllotoxins have been synthesized and evaluated for their inhibitory activity against the human DNA topoisomerase II as well as for their activity in causing cellular protein-linked DNA breakage. The results showed that none of the compounds are active as a result of the C-2' chloro substitution on ring E. This would suggest that the free rotation of ring E is essential for the aforementioned enzyme inhibitory activity. In addition, these 2'-chloro derivatives showed no significant cytotoxicity (KB).

Prospective analysis of cardiopulmonary responses to laparoscopic cholecystectomy

This prospective study evaluates the extent and temporal course of the cardiorespiratory effects of CO2 during laparoscopic cholecystectomy in otherwise healthy patients. Sixteen patients (M:F = 3:13, average age = 40.2 +/- 14.1 years) were monitored with capnography, transesophageal cardiac output, continuous blood pressure, heart rate, and pulse oximetry. Arterial blood gases were obtained immediately before insufflation of the abdomen with CO2 and before desufflation. Average operative time was 137 +/- 13 minutes. Patients were paralyzed and mechanically ventilated. Minute ventilation was increased if EtCO2 exceeded 45 mmHg or rose by more than 12 mmHg from baseline. End tidal (EtCO2) and arterial CO2 (PaCO2) increased from 31.4 +/- 0.7 mmHg to 42.1 +/- 1.6 mmHg and 33.3 +/- 0.7 mmHg to 43.7 +/- 1.2 mmHg, respectively, during the course of the procedure. Arterial pH decreased from 7.43 +/- 0.01 to 7.34 +/- 0.01, while bicarbonate concentration remained unchanged. Thirteen of the 16 patients required increased minute ventilation due to hypercarbia detected by capnography. Blood pressure increased from 78 +/- 2 mmHg (mean) at the start to 98 +/- 2 mmHg. This increase was coincidental with the maximal PaCO2. Good agreement was observed between paired EtCO2 and PaCO2 measurements. Laparoscopic cholecystectomy with carbon dioxide insufflation causes significant respiratory acidosis and associated cardiovascular changes in otherwise healthy patients. Careful monitoring and cautious application of this technique in patients with pre-existing cardiopulmonary disorders will be required to prevent acute decompensation.

Effect of pH buffer molecules on the light-induced currents from oriented purple membrane

The effect of pH buffers on the microsecond photocurrent component, B2, of oriented purple membranes has been studied. We found that under low salt conditions (less than 10 mM monovalent cationic salt) pH buffers can dramatically alter the waveform of the B2 component. The effect is induced by the protonation process of the buffer molecules by protons expelled from the membrane. These effects can be classified according to the charge transition upon protonation of the buffer. Buffers that carry two positive charges in their protonated form add a negative current component (N component) to B2. Almost all of the other buffers add a positive current component (P component) to B2, which is essentially a mirror image of the N component. Buffers with a pK less than 5.5 have only a small positive buffer component. The pH dependence of the buffer effect is closely related to the pK of the buffer; it requires that the buffer be in its unprotonated form. The rise time of the buffer component increases with the concentration of the buffer molecules. All the buffer effects can be inhibited by the addition of 5 mM of a divalent cation such as Ca2+. Reducing the surface potential slows down the N component but accelerates the P component without affecting the amplitude of the buffer effect significantly. Many of the buffer effects can be explained if we assume that upon protonation of the buffer by a proton expelled from the membrane by light, the buffer molecules move toward the membrane. This backward movement of buffer molecules forms a counter current very similar to that due to cations discussed in Liu, S. Y., R. Govindjee, and T. G. Ebrey. (1990. Biophys. J. 57:951-963).

Effect of 4 beta-arylamino derivatives of 4'-O-demethylepipodophyllotoxin on human DNA topoisomerase II, tubulin polymerization, KB cells, and their resistant variants

Six 4 beta-arylamino derivatives of 4'-O-demethylepipodophyllotoxin were examined for inhibitory activity against human DNA topoisomerase II and tubulin polymerization, their ability to generate protein-linked DNA breaks in cells, and their cytotoxicity toward the KB cell line and its VP-16- and vincristine-resistant variants. Five of these derivatives were 5- to 10-fold more potent than VP-16 as inhibitors of DNA topoisomerase II in vitro, and all of these derivatives could generate the same amount of or more protein-linked DNA breaks in cells than VP-16 at 1-20 microMs. Tubulin polymerization was inhibited by these compounds to different degrees in the order: podophyllotoxin greater than W73 greater than W87 greater than NPF greater than NPC greater than W68 greater than W38 greater than VP-16. These analogues were cytotoxic not only to KB cells but also to their VP-16-resistant and vincristine-resistant variants which showed decreased cellular uptake of VP-16 and a decrease in DNA topoisomerase II content or overexpression of MDR1 phenotype. These characteristics may cause these derivatives to have different spectrums of antitumor activity.

A new method for the study of the formation and transformation of calcium phosphate precipitates: effects of several chemical agents and Chinese folk medicines

A simple method of assaying the formation of amorphous calcium phosphate and its transformation to hydroxyapatite using a conventional pH meter and recorder is described. Its validity was confirmed by direct assay of calcium consumption with atomic absorption spectrophotometry. The method was used to study substances which influence the formation of amorphous calcium phosphate and its transformation to hydroxyapatite, such as albumin, casein, chondroitin sulphate, phospholipid, ATP, Mg2+, Sr2+, pyrophosphate and several Chinese folk medicines.

Amino acid sequence of a phospholipase A2 from the venom of Trimeresurus gramineus (green habu snake)

Two phospholipases A2, named phospholipases A2-I and A2-II, were purified to homogeneity from the venom of Trimeresurus gramineus (green habu snake). The complete amino acid sequence of phospholipase A2-I was determined by sequencing the native protein and the peptides produced by enzymatic (Achromobacter protease I, clostripain, and chymotrypsin) and chemical (hydroxylamine) cleavages of the S-pyridylethylated derivative of the protein. The protein consisted of 122 amino acid residues and was similar in sequence to phospholipases A2 from the venoms of crotalid snakes which belong to the category of Group II. A most striking feature of this protein is that tyrosine at the 28th position which is common in phospholipases A2 and is assumed to be a part of the Ca2(+)-binding loop is replaced by phenylalanine. Such replacement is the first finding in Group II phospholipases A2. Secondary structure compositions of phospholipase A2-I are similar to those of Crotalus atrox phospholipase A2. No appreciable Ca2(+)-induced difference spectrum was observed, due probably to the absence of the effective chromophoric groups in the neighborhood of the Ca2+ binding site although Ca2+ is bound with affinity similar to that for T. flavoviridis phospholipase A2.

Cucurbitacin contents in Hemsleya dolichocarpa

Hemsleya dolichocarpa was studied for its cucurbitacin contents during growing period. A colorimetric method was used to determine the total cucurbitacin levels, and a TLC densitometric assay was employed for estimating dihydrocucurbitacin F and its acetate, two active principles in Hemsleya plants. Cucurbitacin contents rise progressively from May to November; the month of November is thus the most desirable time for harvesting plant materials for medicinal uses. It was noticed that the spoiled plant samples gave an intense color reaction while dihydrocucurbitacin F and its acetate levels were not significantly altered. The accuracy of the assays is discussed.

Decreased Hnf-1 gene expression in mice homozygous for a 1.2-centiMorgan deletion on chromosome 7

The mammalian CYP2E1 gene encodes a cytochrome P450 enzyme that is markedly increased soon after birth. In vitro evidence suggests that the rat CYP2E1 gene is positively regulated by the transcription factor HNF-1 or a protein displaying DNA-binding properties similar to HNF-1. In contrast to newborn wild-type mice and mice heterozygous for a 1.2-centiMorgan deletion on chromosome 7, newborn mice homozygous for this deletion do not show significant expression of the Cyp2e-1 and Hnf-1 genes. However, the Cyp2e-1 and Hnf-1 structural genes are not in the chromosome 7 segment deleted in these mice. Although Cyp2e-1 maps to chromosome 7, it is distal to this deletion; Hnf-1 maps to chromosome 5. These data suggest that the deleted region of chromosome 7 contains a gene encoding a trans-acting factor which is upstream (epistatic) in the regulatory cascade that includes Hnf-1 gene expression.

[Effects of simulated space rhythm (L:D = 0.75h:0.75h) on circadian rhythm in tree shrews (Tupaia belangeri chinensis)]

It is known that contemporary space station revolves at the altitude of 400-500 km in the outer space. The present study was undertaken to investigate the effects of simulated space rhythm (L:D = 0.75 h:0.75 h) at this altitude on circadian rhythm in tree shrews (Tupaia belangeri chinensis) and the effects of endogenous sleep inducing neuropeptide Asp5-alpha-DSIP on the space-rhythm-entrained circadian rhythm. This primitive stock serves as one species of Tupaiidae and is a unique native of South China. Our previous studies have shown that this species showed striking differences in natural circadian rhythm between day and night (e.g. 3.03 degrees C of rectal temperature). Results showed that the above mentioned space rhythm (L:D = 0.75h:0.75h) could drastically disturb the inherent circadian rhythm of Tupaia belangeri chinensis. The maximal peak of motor activity dropped significantly in the morning (0600-1200) and a new enhanced peak (more than 20 times greater than that of the control) was found between 1800-2400, whereas the maximal trough of motor activity (2400-0600) remained basically unchanged. Concurrently, the total amount of 24-h motor activity was significantly decreased and the recovery after the cessation of space rhythm was slow. Experimental results also demonstrated that consecutive administration of Asp5-alpha-DSIP (30 micrograms/kg, i.p.) for 5 days (2 days before and 3 days during space rhythm) did not prevent the basic disturbance of circadian rhythm of Tupaia belangeri chinensis caused by the space rhythm (L:D = 0.75h:0.75h). Nevertheless, no decrease or even some enhancement of the total amount of 24th motor activity was observed during space rhythm or after its cessation.

Antitumor agents. 113. New 4 beta-arylamino derivatives of 4'-O-demethylepipodophyllotoxin and related compounds as potent inhibitors of human DNA topoisomerase II

A number of 4'-O-demethylepipodophyllotoxin derivatives possessing various 4 beta-N-, 4 beta-O- or 4 beta-S-aromatic rings have been synthesized and evaluated for their inhibitory activity against the human DNA topoisomerase II as well as for their activity in causing cellular protein-linked DNA breakage. The results indicated, that for DNA topoisomerase II, a basic unsubstituted 4 beta-anilino moiety is structurally required for the enhanced activity. Substitution on this moiety with CN, COOCH3, COOC2H5, OH and COOCH3, OCH3, COCH3, CH2OH, OCH2O, OCH2CH2O, phenoxy, morpholino, NO2, and NH2 either at the para and/or the meta position yielded compounds which are as potent or more potent than etoposide. Substitution with COOC2H5 and OH at the ortho position afforded inactive compounds. Replacement of the aryl nitrogen with oxygen or sulfur gave compounds which are much less active or inactive. However, replacement of the phenyl ring with a pyridine nucleus furnished compounds which are as active or slightly more active than etoposide. There is a lack of correlation between the ability of these compounds in inhibiting DNA topoisomerase II and in causing protein-linked DNA breaks.

[Protective effects of vitamin E and selenium on myocardial mitochondria in rats--a study on the pathogenic factors and pathogenesis of Keshan disease]

The protective effects of vitamin E (VE) and selenium (Se) on myocardial mitochondria were investigated in rats fed grains (with 0.006 ppm Se) from an endemic area of Keshan disease. The results indicated that supplementing the endemic grains with VE or Se (in 150 ppm and 0.1 ppm respectively) elevated, in different degrees, the depressed activities of four myocardial mitochondrial complexes of electron transport, of which the activity of complex II was increased significantly (P less than 0.05). In addition, the activity of Mn- superoxide dismutase was increased and the content of lipid peroxides was decreased in the myocardial mitochondria of rats of both groups with the supplements. The study shows that VE and Se protect the myocardial mitochondria from damage induced by lipid peroxidation in the rats fed grains from Keshan disease endemic areas.

Antitumor agents. 111. New 4-hydroxylated and 4-halogenated anilino derivatives of 4'-demethylepipodophyllotoxin as potent inhibitors of human DNA topoisomerase II

A series of C-4 hydroxylated and halogenated anilino derivatives of epipodophyllotoxin or 4'-demethylepipodophyllotoxin have been synthesized and evaluated for their inhibitory activity against the human DNA topoisomerase II as well as for their activity in causing cellular protein-linked DNA breakage. Compounds 11-17 and 22 are more potent than etoposide in causing DNA breakage, while compounds 11-13, 15, 16, and 20 are as active or more active than etoposide in their inhibition of the human DNA topoisomerase II. The cytotoxicity in KB cells appears to have no direct correlation with their ability to inhibit DNA topoisomerase II and to cause protein-linked DNA breaks in cells.

Antithrombotic/antiplatelet activity of tetramethylpyrazine

Tetramethylpyrazine (TMPZ) is an active component that can be extracted from certain plants. In China, this herbal extract is used to treat ischemic vascular diseases. We have assessed the antithrombotic activity of TMPZ using arterial and venous thrombosis models in rats. Antithrombotic activity of TMPZ is at least partly due to its potent antiplatelet effect. We have shown that TMPZ inhibits platelet aggregation induced by ADP, collagen, thrombin, and A23187 but not by diacylglycerol (DAG). Platelets that were induced to produce maximal aggregation could be dispersed by the addition of TMPZ. Platelets could then be reaggregated by the addition of DAG. Studies monitoring intracellular ionized calcium suggest that TMPZ inhibits calcium mobilization from both the extracellular medium and from intracellular stores.

Purification and amino acid sequence of basic protein II, a lysine-49-phospholipase A2 with low activity, from Trimeresurus flavoviridis venom

A basic protein (pI 10.3), named basic protein II, was purified to homogeneity from the venom of Trimeresurus flavoviridis (Habu snake) after four chromatographic steps. The amino acid sequence of this protein was determined by sequencing the S-pyridylethylated derivative and its peptides produced by chemical (cyanogen bromide) and enzymatic (chymotrypsin, clostripain, and Staphylococcus aureus V8 protease) cleavages. The protein consisted of 122 amino acid residues and was found to be identical in sequence to basic protein I from the same source except that Asp-58 of basic protein I is replaced by asparagine. Like basic protein I, the structural feature of basic protein II is that Tyr-28 and Asp-49 common in phospholipases A2 from snake venoms and mammalian pancreas are replaced by asparagine and lysine, respectively. Thus, basic protein II belongs to the category of lysine-49-phospholipase A2. The action of basic protein II on 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphorylcholine released only oleic acid, indicating that it has phospholipase A2 activity. Its molar activity toward 1,2-dilauroyl-sn-glycero-3-phosphorylcholine, however, was only 1.7% of that of T. flavoviridis phospholipase A2 isolated previously. Affinity for Ca2+ and reactivity toward p-bromophenacyl bromide of basic protein II were 8 and 5.3 times, respectively, smaller than those of phospholipase A2 from the same source, substantiating the low phospholipase A2 activity of basic protein II.

Tyrosine- and phenylalanine-restricted formula diet augments immunocompetence in healthy humans

Previous studies indicate that limiting tyrosine and phenylalanine intake in the diet decreases tumor growth and metastasis. General health status, immune status, and platelet function were studied in nine healthy human subjects consuming low-protein foods supplemented with formula diets free of tyrosine and phenylalanine to maintain total daily intake of tyrosine at 2.4 mg/kg body wt and phenylalanine at 3.5 mg/kg body wt. This regimen decreased plasma tyrosine (p less than 0.05) but not phenylalanine. Blood indicators of protein status were not changed. Platelet aggregation decreased in response to adenosine diphosphate and platelet activating factor in seven of nine subjects. Natural killer, T-helper, and T-cytotoxic/suppressor lymphocyte numbers proportionally increased relative to neutrophils (p less than 0.05). Natural killer cell activity increased in six of nine subjects. Increased natural killer cell activity and decreased platelet aggregation are two indices associated with decreased tumor growth and metastasis.

Purification and amino acid sequence of basic protein I, a lysine-49-phospholipase A2 with low activity, from the venom of Trimeresurus flavoviridis (Habu snake)

A basic protein (pI 10.2), named basic protein I, was purified to homogeneity from the venom of Trimeresurus flavoviridis (Habu snake) after four chromatographic steps. The amino acid sequence of this protein was determined by sequencing the S-pyridylethylated derivative of the protein and its peptides produced by chemical (cyanogen bromide and formic acid) and enzymatic (chymotrypsin, Achromobacter protease I, and Staphylococcus aureus V8 protease) cleavages. The protein consisted of 122 amino acid residues and was similar in sequence to phospholipases A2 from the venoms of crotalid and viperid snakes. A most striking feature of this protein is that aspartic acid at the 49th position common in phospholipases A2 is replaced by lysine. When the protein acted on 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphorylcholine, oleic acid was preferentially released, indicating that the protein has phospholipase A2 activity. Its molar activity toward 1,2-dilauroyl-sn-glycero-3-phosphorylcholine, however, was 1.5% that of T. flavoviridis phospholipase A2 isolated previously. The fact that both affinity to Ca2+ and reactivity to p-bromophenacyl bromide of basic protein I are approximately one order of magnitude lower than those of T. flavoviridis phospholipase A2 might explain the low activity of basic protein I.

Augmentation of antimetastatic activity of interferon and tumor necrosis factor by heparin

Interferon (IFN) and tumor necrosis factor (TNF) suppress the development of experimental metastasis and when used together, TNF and IFN show synergistic activity. However, the use of TNF is limited by its ability to initiate inappropriate hemostasis. Hemostatic effects are exaggerated by the procoagulant activity of certain tumor cell lines. Therapy with anticoagulants are indicated to block the effects of tumor cell products as well as chemotherapeutic side effects. Heparin is a glycosaminoglycan with diverse biological activity, including the ability to rapidly accelerate the inactivation of active clotting factors. The present studies have explored the therapeutic effects of combining heparin with TNF or interferon on experimental metastasis in mice using a melanoma cell line (B16BL6). Our data indicate that continued heparinization augments the antitumor activity of both interferon and TNF. Alterations of the hemostatic and immune systems play a role in the producing the observed effect.

[Manifestations of fluorescein angiography in choroidal melanoma]

This paper reported on the manifestations of fundus fluorescein angiography in 21 patients with choroidal melanoma. According to the findings of fluorescein angiography, we suggest that this disease can be classified into 3 types: type I shows hyperfluorescent mottles (12 cases); type II shows hyperfluorescent spots and patches, (4 cases); type III shows a dark area in the tumor body, (5 cases). The angiographic characteristics of the three types of melanoma and their histopathologic changes are discussed. The differential diagnosis of the three types of melanoma from metastatic choroidal carcinoma, senile macular degeneration with subretinal hemorrhage and choroidal hemangiomas is discussed. For the first time choroid melanoma has been classified into 3 types according to fluorescein angiography. It may contribute to the early diagnosis of this disease.

Podophyllotoxin analogs: effects on DNA topoisomerase II, tubulin polymerization, human tumor KB cells, and their VP-16-resistant variants

Several derivatives of podophyllotoxin with modifications at the C-4 position of ring C, in addition to demethylation at the C-4' position of ring E, were examined for inhibitory activity against DNA topoisomerase II and tubulin polymerization, generation of protein-linked DNA breaks, and cytotoxicity against KB cells and VP-16-resistant KB variants. Substitution of podophyllotoxin with a group in the beta configuration at the C-4 position of ring C resulted in compounds with greater inhibitory activity against DNA topoisomerase II and lower inhibitory activity against tubulin polymerization than those with an alpha configuration. These active analogs exhibited the same mechanism of DNA topoisomerase II inhibition as the epipodophyllotoxin derivative VP-16, which causes protein-linked DNA breaks in vitro as well as in cells. Two analogs selectively inhibited DNA topoisomerases II to a greater extent than tubulin polymerization. These analogs were cytotoxic towards KB cells in addition to VP-16-resistant KB cell lines, which indicated limited cross-resistance with VP-16 in VP-16-resistant KB variants.

Interaction of several nucleoside triphosphate analogues and 10-hydroxycamptothecin with human DNA topoisomerases

DNA topoisomerase I (Topo I) can exist in several different molecular weight forms in human leukemic cells. The Mr 98,000 form of Topo I was inhibited by several nucleoside triphosphates and their analogues at a 500 microM concentration in the order: dideoxy-GTP greater than 2-bromo-dATP greater than dideoxy-ATP greater than dideoxy-CTP greater than 2-fluoro-dATP greater than 2-chloro-dATP. The same concentration of these nucleoside triphosphates also inhibited the Mr 32,000 and the Mr 35,000 Topo I forms in the order: 2-bromo-dATP greater than dideoxy-GTP greater than 2-fluoro-dATP greater than dideoxy-ATP; however, dideoxy-CTP and 2-chloro-dATP did not inhibit these forms. ATP inhibited both the large and the small molecular weight forms of Topo I at a concentration of 8 mM. DNA topoisomerase II (Topo II) isolated from human leukemic cells requires ATP for its activity. Of the nucleoside triphosphates examined, only dATP could substitute for ATP. In the presence of 500 microM ATP, equimolar concentrations of 2-bromo-dATP, dideoxy-ATP, 2-chloro-dATP, 2-fluoro-dATP, and dideoxy-GTP nucleotide analogues inhibited the unknotting activity of the Topo II enzyme. When the nucleotide analogue concentration was decreased to 250 microM, only 2-bromo-dATP still had a significant inhibitory effect on Topo II. With the exception of 2-bromo-dATP, the analogues studied appeared to inhibit the nicking step of both the Topo I and Topo II enzyme activity. These results differ from previously described mechanisms of inhibition by camptothecin of Topo I and etoposide of Topo II. These enzymatic studies suggest the inhibition of Topo I and Topo II activities could contribute to the cytotoxicity of the respective nucleoside analogues in cell culture, particularly when high concentrations of these nucleoside analogues accumulate as triphosphates inside the cells.

Antitumor agents. 100. Inhibition of human DNA topoisomerase II by cytotoxic ether and ester derivatives of podophyllotoxin and alpha-peltatin

A principal mechanism of action of the clinical antitumor drugs etoposide (1) and teniposide (2) is the inhibition of catalytic activity of type II DNA topoisomerase and concurrent enzyme-mediated production of lethal DNA strand breaks. Substitution of the glycosidic moiety of 1 or 2 by ester and ethers, as well as the esterification and etherification of alpha-peltatin (4) including its glucosidic ethylidene and thenylidene cyclic acetals (25 and 26), has afforded compounds of much less activity than that of 1. The in vitro cytotoxicity (KB) appears to have no correlation with the inhibitory activity of the human DNA topoisomerase II.

Sorption and Metabolism of Metolachlor by a Bacterial Community

A stable bacterial community absorbed and transformed the herbicide metolachlor [2-chloro- N -(2-ethyl- 6-methylphenyl)- N -(2-methoxy-1-methylethyl)-acetamide] from a liquid medium. About 80% of the added ring-[U- 14 C]metolachlor (50 μg/ml) disappeared from the medium and accumulated inside the cells. The ratio of cellular 14 C to 14 C in 1 mg of supernatant reached a value of 1.1 × 10 4 in a 10-day-old culture. 14 C remaining in the medium consisted primarily of two dechlorinated products of metolachlor with m/z 233 and 263 as determined by mass spectrometry. The 14 C-labeled material absorbed by the cells was strongly bound; only 2% of the 14 C was released into deionized water after shaking for 3 h. Approximately 96% of the 14 C associated with the biomass was extracted with acetone, and high-performance liquid chromatographic analysis of this fraction showed six peaks containing radioactivity. Since no metolachlor was detected by chromatographic analysis, it was concluded that the radioactivity recovered from the cells represented transformed products of metolachlor. Pure cultures isolated from the bacterial mixed culture were less effective in transforming and accumulating metolachlor. These results suggest that it may be advantageous to seed an aquatic environment with a mixture of microorganisms, rather than individual microbial species, as a method for removal or detoxification of metolachlor.

Transformation of Metalaxyl by the Fungus Syncephalastrum racemosum

The fungus Syncephalastrum racemosum (Cohn) Schroeter was found to transform the fungicide metalaxyl [ N -(2,6-dimethylphenyl)- N -(methoxyacetyl)-alanine methyl ester] in pure culture. After 21 days of incubation in a basal medium amended with 5 μg of metalaxyl per ml, more than 80% of the compound was transformed by the fungus. The transformation rates decreased as the concentrations of metalaxyl increased from 5 to 100 μg/ml. No transformation was observed when the concentration of metalaxyl was higher than 200 μg/ml. Two isomeric metabolites and a mixture of two other isomeric metabolites were isolated from the organic extract of the growth medium and identified as N -(2-methyl-6-hydroxymethylphenyl)- N - and N -(2-hydroxymethyl-6-methylphenyl)- N -(methoxyacetyl)-alanine methyl ester and N -(3-hydroxy- and N -(5-hydroxy-2,6-dimethyl-phenyl)- N -(methoxyacetyl)-alanine methyl ester according to their mass-spectral and nuclear magnetic resonance-spectral characteristics. Benzylic hydroxylation of the methyl side chains and/or aromatic hydroxylation appeared to be the major reactions involved in the metabolism of metalaxyl.

[Outbreak of intestinal infectious diseases due to contamination of two-time pressure water supply with sewage]

Two outbreaks of intestinal infectious disease occurred due to contaminations of Two-time pressure water supply at Hai-zhou and Tai-ping districts in 1985 and 1986. There were 659 cases, the incidence rate was 55%. The cause of contamination was that the underground water storage tanks were contaminated by domestic sewage, which back-flowed into the tanks through an overflow pipe, connecting the tank with observation well of the sewage system.