Gas chromatographic determination of aldicarb and its metabolites in urine

A method is described for the determination of aldicarb and its metabolites (the sulphoxide and sulphone) in urine by gas chromatography with flame photometric detection (GC-FPD). The sample was concentrated with a column containing activated charcoal and Florisil, and then eluted with dichloromethane-acetone (1:1, v/v). The aldicarb and aldicarb sulphoxide in the eluate solution were oxidized to aldicarb sulphone and the total sulphone concentration was determined by GC-FPD after extraction with dichloromethane and clean-up with an activated charcoal column. The detection limit was 0.0024 mg/l. The mean recoveries from spiked urine in the range 0.04-0.12 mg/l were 90.9%, 86.6%, 92.6% for aldicarb, aldicarb sulphoxide and aldicarb sulphone, respectively.

Modulation of extracellular matrix gene expression by heparin and endothelial cell growth factor in human smooth muscle cells

We have previously shown that human vascular smooth muscle cells grown for several passages in the presence of heparin and endothelial cell growth factor (ECGF) exhibit profound alterations in the synthesis of extracellular matrix proteins. In the present study, we demonstrate that the mRNA steady-state levels for various matrix macromolecules were altered in the presence of heparin and ECGF, but not ECGF alone. Specifically, the expression of types I and IV collagens, fibronectin, and decorin proteoglycan genes were markedly inhibited, whereas that of versican proteoglycan and beta-actin genes were unaffected. The effects were fully reversible. The suppression of the collagen gene expression was related to decreased collagen production by cells incubated with heparin and ECGF. Thus, heparin and ECGF synergistically elicit a coordinate and selective inhibition of matrix gene expression in human smooth muscle cells.

Ultrafast all-optical deflection based on an induced area modulation in nonlinear materials

A novel all-optical area-modulation scheme is suggested and experimentally demonstrated. In a mutually perpendicular interaction geometry inside a nonlinear material, the signal beam, which passes through an induced temporal prism formed by an area-modulated optical pump beam, undergoes a spatial phase modulation that leads to a beam deflection. Advantages and potential applications of the new all-optical modulation are addressed.

The influence of limb alignment on the gait of above-knee amputees

Biomechanical gait tests on above-knee amputees were conducted in which the alignment of the prosthesis was changed systematically. An eight-segment biomechanical model of the above-knee amputee was developed to analyse and present the three-dimensional kinematic and kinetic data obtained. The effects of alignment changes on the above-knee amputees' gait were studied in terms of the angular displacements of the lower limbs, ground reactions and intersegmental moments. It was found that following the alignment changes the angular displacement at the hip joint on the prosthetic side showed compensatory actions by the amputee. The ground reaction force was sensitive to alignment changes, and in particular, the changes in the characteristics of the fore-aft component of the ground force could be related to the alignment changes. The antero-posterior intersegmental moments at the prosthetic ankle and knee joints were evidently influenced by alignment.

Acetylcholine, Ca2+ overload and oscillatory potentials in isolated ventricular myocytes

The events caused by overdrive-induced calcium overload were studied in guinea pig isolated ventricular myocytes. Overdrive may induce oscillatory potentials (Vos) and a prolonged depolarization (Vex), as well as the underlying currents (Ios and Iex, respectively). Acetylcholine (ACh) reduced or abolished these events, an action which was blocked by atropine. Norepinephrine exaggerated the effects of overdrive, and ACh markedly antagonized such an enhancement. Caffeine at low concentrations increased both Ios and Iex whereas at high concentrations caffeine abolished Ios but increased Iex. Quinacrine abolished both events. Voltage clamp depolarizing steps abolished Ios (and did not reverse it). Thus, the effects of Ca overload are antagonized by ACh in the absence and presence of sympathetic enhancement. Also, the mechanism underlying Ios appears to involve an electrogenic Ca extrusion and not an increase in a nonspecific conductance.

Replication of bovine papillomavirus type 1 DNA initiates within an E2-responsive enhancer element

When bovine papillomavirus transforms cells in vitro, it maintains its genome as a multicopy nuclear plasmid. Plasmid DNA extracted from such transformed cells was analyzed by the two-dimensional gel electrophoresis technique of Brewer and Fangman (B. Brewer and W. Fangman, Cell 51:463-471, 1987). The replication intermediates detected in these assays were found to be the sums of the oligomeric and monomeric forms of the replicating plasmids. The multimeric DNAs were shown by field inversion gel electrophoresis and partial restriction digestion to be head-to-tail concatemers of the monomeric forms. Furthermore, the multimers progressed in size by steps of one monomer, indicating that they did not arise by replication segregation mistakes of the unit length, which would predict a ladder spaced by integrals of two monomers. To map the plasmid DNA replication origin, the replication intermediates of the monomers were isolated by successive sucrose gradient centrifugation and then examined by the two-dimensional gel electrophoresis method. The patterns detected show that bovine papillomavirus type 1 replicates in these cells bidirectionally and that one replication origin site in the viral genome is utilized. By employing several restriction enzymes and specific viral DNA probes to dissect the replication intermediates, we were able to map the origin of initiation site with some precision. The initiation site, which maps to bovine papillomavirus type 1 DNA position 7730 +/- 100 bp, places the origin within that region of the viral upstream regulatory region which contains the major cluster of transcription factor E2-binding sites, E2RE1. Thus, the actual viral plasmid origin of replication maps near, but outside, genetic elements previously shown to be important for plasmid maintenance.

[Isolation and identification of oral spirochaetes and Fusobacterium in juvenile periodontitis]

Periodontal pocket specimens of 40 juveniles periodontitis (JP) and specimens from gingival sulcus in 40 normal juveniles (NP) were examined. 25 strains of anaerobic oral spirochaete (62.5%) (17 strains were Treponema microdentium, 3 strains macrodentium, 2 strains T orale, 3 strains Borrelia) and 21 strains of fusobacterium were isolated in 40 JP. In 40 NP, 2 strains of spirochaetes (5%) and 3 strains fusobacterium (7.5%) were found. This study shows that there is a relationship between the infection of spirochaeta, fusobacterium and JP.

[Dissolution of metronidazole stilus]

Metronidazole stilus is a new preparation to be inserted into periodontal pockets for treatment of periodontitis. The certificate and file number of approval given to this new product were issued by the Ministry of Public Health in August, 1989. Its shape looks like a toothpick and the width, thickness and length are 1.5mm, 0.7mm and 3 cm, respectively. The content of metronidazole in each cm of the stilus is 2.2 mg. We have studied the dissolution of the new preparation by rotation basket method. The kinetic process of dissolution approximates first order kinetics. The K, t0.5 and t0.9 are 0.0624 min-1, 12.8 and 38.6 minutes, respectively. The requirement is that the dissolved percentage should not be lower than 60% of the added amount in 30 minutes. In order to have a dissolution test similar to that of the stilus in dental pockets, we examined the dissolution in static condition. The results showed that a very high dissolution rate appeared in the beginning, but it decreased quickly, and 71.76% of metronidazole was not dissolved until 48 hours. So one insertion per two days for clinical use is suggested.

Prebiotic synthesis of histidine

The prebiotic formation of histidine (His) has been accomplished experimentally by the reaction of erythrose with formamidine followed by a Strecker synthesis. In the first step of this reaction sequence, the formation of imidazole-4-acetaldehyde took place by the condensation of erythrose and formamidine, two compounds that are known to be formed under prebiotic conditions. In a second step, the imidazole-4-acetaldehyde was converted to His, without isolation of the reaction products by adding HCN and ammonia to the reaction mixture. LC, HPLC, thermospray liquid chromatography-mass spectrometry, and tandem mass spectrometry were used to identify the product, which was obtained in a yield of 3.5% based on the ratio of His/erythrose. This is a new chemical synthesis of one of the basic amino acids which had not been synthesized prebiotically until now.

[Specific monoclonal antibodies to F41 adhesin of enterotoxigenic Escherichia coli and their potential uses as diagnostic and therapeutic reagents]

A set of hybridoma cell lines, namely, L10, B10, C32, B1, E7, E40 and B49, secreting monoclonal antibodies (MABs) specific to F41 adhesin antigens of ETEC was obtained by somatic hybridization. These MABs manifested strongly specific binding reactivities in DA, ELISA and IFA to all tested F41+ ETEC strains. All these MABs recognized the same or closely related epitopes on the adhesin, as indicated in antigen-competition ELISA with HRP-labeled MABs. The distribution patterns of these epitopes which appeared repeatedly on each pilus were visualized by MAB-immunogold technique and immunoelectron microscopy. The adhesion of ETEC bearing F41 adhesin to the epithelial cells of small intestine from new borne calves and piglets was inhibited in vitro by F41-specific MABs. A dot-immunobinding assay based on F41-specific MABs was developed for determining F41 antigens in fecal samples with HRP-labeled MABs. The assay was highly sensitive and specific, and could be used in rapid detection and screening of F41 adhesin antigens in field samples.

Pharmacokinetics and autoradiography of [3H] or [14C]stepholidine

After iv [3H]stepholidine (SPD) 12 MBq/kg, the concentration-time curve in rats was found to be a two-compartment open model. The distribution phase T1/2 alpha = 3.6 min, the elimination phase T1/2 beta = 168 min. The absorbed radioactivities of [3H] SPD in 15-30 min were 80-87%. The amounts of [3H]SPD bound to plasma protein, liver and kidney homogenates were estimated to be 37, 31, and 30%, respectively. During 3 d after ip [3H]SPD 50 MBq/kg, 56% of the radioactivity was excreted in urine and 5% in feces, thus, it suggested that [3H]SPD was mainly excreted by kidneys. After iv a single dose of [14C]SPD in mice, the whole-body autoradiography showed that [14C]SPD was rapidly distributed among various tissues. High radioactivities were found in kidneys, liver, brain, salivary glands, Harder's glands, heart blood and muscle at 2 min and intensively localized in kidneys and stomach mucosa at 30 min. The radioactivities in these tissues disappeared 4 and 8 h later, while that in intestine could not be detected 24 h later.

Effect of a cell differentiation inducer, ganglioside GM3, on the neutral glycosphingolipid composition and cell membrane fluidity of a human promyelocytic leukemia cell line HL-60

In this paper the authors confirmed the finding reported by Nojiri et al that exogenous ganglioside GM3 could induce HL-60 cells to differentiate along the monocytic-macrophage route with significant inhibition of proliferation. It was found that after differentiation the neutral GSL content of CDH and CMH increased, while that of CXH, a polyhexosyl ceramide with a TLC mobility slower than CQH, decreased significantly. The membrane fluidity of HL-60 cells decreased after GM3 treatment.

Molecular Characterization of the Brittle-2 Gene Effect on Maize Endosperm ADPglucose Pyrophosphorylase Subunits

Activity of the enzyme ADPglucose pyrophosphorylase is known to be reduced in maize (Zea mays L.) endosperm mutants at two independent loci, Shrunken-2 (Sh(2)) and Brittle-2 (Bt(2)). Spinach leaf ADPglucose pyrophosphorylase has previously been shown to comprise two subunits of 51 and 54 kilodaltons. Anti-bodies raised to each of the two subunits of spinach leaf ADPglucose pyrophosphorylase were found to cross-react to different bands on Western blots prepared from polyacrylamide gel electrophoresis separated wild-type maize endosperm proteins. The anti-spinach leaf 51 kilodalton subunit antibody cross-reacted with a 55 kilodalton maize endosperm protein and the anti-spinach leaf 54 kilodalton subunit antibody cross-reacted with a 60 kilodalton maize endosperm protein. These immunological reactions were observed in maize endosperm extracts and with a highly purified preparation of maize endosperm ADPglucose pyrophosphorylase. Mutant bt(2) endosperm lacked the 55 kilodalton subunit while mutant sh(2) endosperm lacked the 60 kilodalton subunit on Western blots. These results suggest that the maize endosperm ADPglucose pyrophosphorylase is made up of two immunologically dissimilar subunits and that the bt(2) and sh(2) mutations cause reduction in ADPglucose pyrophosphorylase activity through the lack of one of these two subunits. An ADPglucose pyrophosphorylase cDNA clone antigenically selected from a rice seed cDNA expression library was found to hybridize strongly with a cDNA corresponding to a maize endosperm transcript which is absent in a W64A bt(2) mutant. Thus, the bt(2) mutant causes the absence not only of the small subunit but of the corresponding transcript. Bt(2) is implicated as the structural gene for the small (54 kilodalton) subunit of maize endosperm ADPglucose pyrophosphorylase.

[Relation of the changes in hemorheologic indices and the site and size of cerebral infarction]

According to the CT findings, 83 cases of cerebral infarction were divided into two groups. One group consisted of cases with occlusion of the cerebral arterial main trunks and the other of those with occlusion of the penetrating arteries. The HCT and the whole blood viscosity were higher in the former group, whereas the rate of platelet aggregation was higher in the latter group. These results suggested that the physiopathology involved in the formation of the large cerebral infarction in the cerebral cortex and subcortex was different from that of the small infarction in the deep cerebral structures. Besides, it was found that the blood viscosity has positive relationship with the size of the cerebral infarction in the former group. It was presumed that the HCT and the blood viscosity should be reduced immediately for treating the larger cerebral infarction, but to lower the rate of platelet aggregation for treating the small infarction in the deep cerebral structures would be of benefit.

Effects of strophanthidin on the slow inward current in guinea-pig isolated ventricular myocytes

1. The effect of strophanthidin on the slow inward current (Isi) and on contractile force were studied in guinea-pig isolated ventricular myocytes and intact papillary muscles, respectively. In myocytes, both low (10 nmol/L) and high (1-10 mumols/L) concentrations had small or no effects in either direction on Isi whereas norepinephrine (10-100 nmol/L) increased it. To determine whether the same results are obtained after decreasing or increasing intracellular calcium or sodium, the same concentrations of strophanthidin were tested in different procedures that are known to (i) increase [Ca]i and decrease [Na]i (high [Ca]o, 3.6-5.4 mmol/L; low [Na]o, 112 mmol/L; (ii) decrease [Ca]i and increase [Na]i (low [Ca]o, 0.45-1 mmol/L; Sr, 1 mmol/L; (iii) decrease [Ca]i and [Na]i (Cd, 0.1-0.2 mmol/L); and (iv) increase [Ca]i and [Na]i (veratridine, 0.2 mumol/L). High [Ca]o and veratridine increased whereas low [Ca]o and Cd decreased Isi. In contrast, during these various procedures, strophanthidin had small and inconsistent effects at a low or high concentration. In intact papillary muscles, low strophanthidin decreased whereas high strophanthidin increased contractile force. It is concluded that strophanthidin has little direct or indirect effect on Isi and that the decrease in force by low and increase in force by high concentrations in intact muscle are probably related to demonstrated decrease and increase, respectively, in intracellular sodium activity.

[The effect of intrapartum and neonatal asphyxia on the cognitive and behavioral development of children]

The present study includes 4 groups of subjects: 30 children with a history of intrapartum asphyxia, 30 children with a history of mild neonatal asphyxia, 15 children with a history of severe but transitory neonatal asphyxia, and 30 children who had normal deliveries. Psychological and neuropsychological assessments were done at 6 years of age. There are no significant difference among 4 groups in IQ, social maturity age, most neuropsychological functions and incidence of attention deficit disorder with hyperactivity. 4 test scores in Halstead-Reitan Battery infer to visual-motor functioning showed backwardness in asphyxiated groups. Behavior problems are more frequently seen in the asphyxiated groups than in the control group.

Nonlinear-optical response in polythiophene films using four-wave mixing techniques

We report measurement of X(3) in polythiophene and a homologous series of polycondensed thiophene-based polymers above and below the absorption edge using the folded-boxcar four-wave mixing technique. Above gap the nonlinear coefficient X(3) was found to be one of the largest and fastest in a polymer.

Quinacrine decreases the slow inward current and force in guinea pig ventricular tissue

In guinea pig isolated ventricular myocytes, quinacrine (40 microM) decreases the action potential amplitude and duration, and markedly decreases the slow inward current (Isi). A lower quinacrine concentration (20 microM) has similar but smaller effects. In guinea pig papillary muscles, quinacrine decreases contractile force reversibly. Thus, in myocardial fibers the decrease in Isi by quinacrine appears to predominate over the inhibition of Na-Ca exchange found in membrane vesicles.

Template supercoiling during ATP-dependent DNA helix tracking: studies with simian virus 40 large tumor antigen

Incubation of topologically relaxed plasmid DNA with simian virus 40 (SV40) large tumor antigen (T antigen), ATP, and eubacterial DNA topoisomerase I resulted in the formation of highly positively supercoiled DNA. Eukaryotic DNA topoisomerase I could not substitute for eubacterial DNA topoisomerase 1 in this reaction. Furthermore, the addition of eukaryotic topoisomerase I to a preincubated reaction mixture containing both T antigen and eubacterial topoisomerase I caused rapid relaxation of the positively supercoiled DNA. These results suggest that SV40 T antigen can introduce topoisomerase-relaxable supercoils into DNA in a reaction coupled to ATP hydrolysis. We interpret the observed T antigen supercoiling reaction in terms of a recently proposed twin-supercoiled-domain model that describes the mechanics of DNA helix-tracking processes. According to this model positive and negative supercoils are generated ahead of and behind the moving SV40 T antigen, respectively. The preferential relaxation of negative supercoils by eubacterial DNA topoisomerase I explains the accumulation of positive supercoils in the DNA template. The supercoiling assay using DNA conformation-specific eubacterial DNA topoisomerase I may be of general use for the detection of ATP-dependent DNA helix-tracking proteins.

Identification of a developmentally regulated gene for a 140-kDa secretory protein in salivary glands of Chironomus tentans larvae

Secretory proteins are synthesized in salivary glands of the insect, Chironomus tentans, and assemble in vivo into silk-like threads which aquatic larvae use to construct tubes for filter feeding and pupation. Thus far, all known secretory protein genes contain repetitious protein-coding sequences and are located in cytological structures known as Balbiani rings, giant puffs found on polytene secretory cell chromosomes. In this paper we describe the identification of another secretory protein gene which is comprised of repeated sequences; however, this gene is not located in a Balbiani ring. Two partial cDNA clones from a 3.6-kilobase pair poly(A)+ RNA were sequenced and found to contain two open reading frames for protein synthesis. Antibodies were raised against synthetic oligopeptides whose sequences were derived from these two open reading frames. An immunoaffinity-purified antibody for one of these peptides bound specifically to a 140-kDa secretory protein (sp140). The cDNA sequences contain tandem repeats of 42 base pairs which encode a repeat of 14 amino acids with a composition and oligopeptide sequence similar to other secretory proteins. The C. tentans genome contains about 70 copies of this 42-base pair repeat organized as a contiguous block of 3 kilobase pairs or less. The sp140 gene was mapped by in situ hybridization to polytene chromosome band I-17-B. Developmental studies of protein accumulation, steady-state levels of mRNA, and relative transcription rate suggested that the sp140 gene is developmentally regulated so that maximal expression is achieved during the prepupal stages of the fourth larval instar. Based upon these results we proposed that sp140 gene belongs to a prepupal class of secretory protein genes. While the sp140 gene shares structural and expression characteristics with other secretory protein genes, its unique chromosomal location shows that this multigene family is not restricted to Balbiani rings.

Self-phase modulation in multimode optical fibers produced by moderately high-powered picosecond pulses

The spectral distributions of 8-psec ultrashort laser pulses propagating through multimode glass fibers were measured and compared with those of single-mode fibers at comparable intensities. In multimode optical fibers the spectral broadening arising from self-phase modulation was found to be asymmetric to the Stokes side owing to modal dispersion.

Three-dimensional imaging systems: a new development

An optical system which produces 3-D images exhibiting continuous parallax with no flipping or cardboarding is described. Both integral and lenticular images can be recorded on photographic film without recourse to a specialized environment. Standard photographic processing and enlarging techniques are used to obtain hard copy. Measurements on commercially available retrodirective screens and a new retroscreen arrangement show that the new screen developed gives significant advantages. A retrodirective and a transmission version of the system have been constructed.

Discussion of the optics of a new 3-D imaging system

The geometric optics of a new 3-D imaging system, which has several innovative features, is discussed. The principles governing the primary design of the system are considered in some detail, and the calculation method employed in achieving the basic design parameters is presented. The aberration of the system is then investigated in detail using primary aberration theory, and the limitations imposed on a light beam passing through the arrangement is discussed quantitatively.

Identification of a downstream sequence and binding protein that regulate adenovirus major late promoter transcription in vitro

Gel electrophoresis mobility shift and DNase I footprint assays detect a cellular nuclear protein in extracts made from uninfected human cells which binds to a downstream promoter sequence (DPS) in the human adenovirus 2 major late promoter. By DNase I footprint and mutation analyses, we have determined that this new regulatory element extends from positions +146 to +165 (relative to the cap site at position +1). We show by UV cross-linking that a 40-kDa polypeptide specifically binds to this region. Mutations within the DPS which decrease protein binding by 80-90% also cause a 2.5-3-fold decrease in in vitro major late promoter transcription efficiency. Alteration of the template in the 5'-flanking region of the DPS does not affect nuclear protein binding or transcription efficiency. Interestingly, a T----G transversion at position +160 which increases protein binding also impairs promoter activity.

Caffeine, mental stress, and risk for hypertension: a cross-cultural replication

Separate and combined effects of caffeine and mental arithmetic stress on systolic blood pressure (SBP) and heart rate (HR) were assessed in a double-blind, placebo-controlled study. Thirty-six Chinese nationals, half with and half without a family history of hypertension, received either 0, 125, or 250 mg of caffeine in three separate experimental sessions, each preceded by a 12-hour abstention from caffeine consumption. Caffeine and mental stress elevated SBP, but caffeine did not potentiate the SBP response to mental stress. Caffeine did not affect HR. A positive family history of hypertension was associated with larger SBP elevations to the higher dose of caffeine. Family history of hypertension was associated with larger blood pressure elevations during mental stress, but only under conditions of high-level stimulation provided by the initial exposure to the stress. These results support previous findings of greater cardiovascular reactivity to laboratory stress in individuals at high risk for hypertension.

Prebiotic synthesis of imidazole-4-acetaldehyde and histidine

The prebiotic synthesis of imidazole-4-acetaldehyde and imidazole-4-glycol from erythrose and formamidine has been demonstrated as well as the prebiotic synthesis of imidazole-4-ethanol and imidazole-4-glycol from erythrose, formaldehyde and ammonia. The products were identified by TLC, HPLC, and LC-MS by comparison with authentic samples. The maximum yields of imidazole-4-acetaldehyde, imidazole-4-ethanol, and imidazole-4-glycol obtained in these reactions are 1.6, 5.4, 6.8% respectively, based on the erythrose. Imidazole-4-acetaldehyde would have been converted to histidine on the primitive earth by a Strecker synthesis, and several prebiotic reactions would convert imidazole-4-glycol and imidazole-4-ethanol to imidazole-4-acetaldehyde.

Roles of DNA topoisomerases in simian virus 40 DNA replication in vitro

We examined the roles of DNA topoisomerases in the replication of simian virus 40 (SV40) DNA in a cell-free system composed of an extract from HeLa cells supplemented with purified SV40 tumor antigen. When the activities of both topoisomerase I (EC 5.99.1.2) and topoisomerase II (EC 5.99.1.3) in the extract were blocked with specific inhibitors or antibodies, DNA synthesis was decreased by a factor of 15-20. Addition of purified HeLa DNA topoisomerase II to extracts immunologically depleted of both topoisomerases completely restored replication, and the replication products consisted largely of monomeric daughter molecules. Addition of purified HeLa DNA topoisomerase I to depleted extracts restored DNA synthesis, but the primary products were multiply intertwined, catenated daughter molecules. We conclude that DNA topoisomerases have at least two roles in the replication of SV40 DNA. Either topoisomerase I or topoisomerase II is sufficient to provide the unlinking activity necessary for fork propagation during SV40 DNA replication. However, topoisomerase II is uniquely required for the segregation of newly synthesized daughter molecules.

Research note: sleep problems of normal Chinese adolescents

Eight hundred and forty-six Chinese adolescents were surveyed concerning sleep behaviours including insomnia, nightmares, somniloquism, somnambulism, bruxism, and enuresis. Bruxism was reported most frequently (22%) followed by somniloquism (17%) and insomnia (14.9%). Subjects were compared by sex, age, and rearing by parents or parent surrogates. Cross cultural comparisons and the possible significance of findings are discussed.

[Fetal liver cell transfusion in chemotherapy of malignant tumors and blood diseases]

From Feb. to Dec. 1985, 15 patients were treated with fetal liver cell transfusion (FLT). They were 10 cases with malignant tumors treated by chemotherapy (tumor group) and 5 with blood diseases (blood group). Under strict aseptic technique, 3 1/2-6 month old fetus was selected for preparing suspension of the fetal liver cells on the superclean table. The speed of FLT should be increased gradually from slow to rapid. There are 1.8 X 10(8)-4 X 10(12) fetal liver cells in a fetus of more than 5 months old, in which most are CFU-C. In the tumor group, after FLT, white blood cell, platelet and hemoglobin increased by 700-3,900/mm3, 5,000-116,000/mm3 and 0.5-2.0 gm/mm3 respectively. But in the blood group, they increased by 800-1,300/mm3, 14,000-84,000/mm3 and 0.4-11.0 gm/mm3. In most of the cases, these hematological indexes reached up to the highest in 2 weeks after FLT. It suggests that FLT can improve the peripheral blood picture obviously and stimulate bone marrow. Experiment confirms that there are considerable hematopoietic stem cells in the fetal liver, by which the functions of hematopoiesis and immunity are able to recover. It is more marked in the tumor group than in the blood group. FLT provides a favourable condition for high dose chemotherapy.

Identification of DNA topoisomerase II as an intracellular target of antitumor epipodophyllotoxins in simian virus 40-infected monkey cells

The effect of antitumor epipodophyllotoxins, etoposide (VP-16) and teniposide (VM-26), on chromosomal DNA in mammalian cells was studied using SV40 virus-infected monkey cells as a model system. Treatment of SV40 virus-infected monkey cells with these drugs results in DNA breaks on intracellular SV40 DNA. The broken DNA strands are sensitive to phenol extraction, suggesting that they are associated with tightly linked protein(s). Several pieces of evidence suggest that DNA topoisomerase II is covalently linked to the broken SV40 DNA strands following drug treatment. ovobiocin, an inhibitor of topoisomerase II, blocks the epipodophyllotoxin-induced SV40 DNA breaks in vivo and in vitro. Epipodophyllotoxin-induced cleavage sites on intracellular SV40 DNA are strikingly similar to those produced on purified SV40 DNA by purified calf thymus DNA topoisomerase II. The protein-linked SV40 DNA is specifically immunoprecipitated by antisera against topoisomerase II. We thus conclude that epipodophyllotoxins induce chromosomal DNA breakage via DNA topoisomerase II. The physiological effects of epipodophyllotoxins on cell death, chromosomal DNA breakage, sister chromatid exchanges, and chromosomal aberrations may be the consequence of drug interaction with DNA topoisomerase II. Our present results are also consistent with the proposal that epipodophyllotoxins interfere with the breakage-reunion reaction of DNA topoisomerase II by stabilizing an enzyme-DNA complex in its putative cleavable state.

Patterns of psychiatric consultation in a Chinese general hospital

The authors conducted a study of psychiatric consultation in a Chinese general hospital. Seventy-five inpatients (0.74% of the patients in the hospital) were referred by different services over a 1-year period. Internal medicine referred the most patients, and organic brain syndromes were the most common diagnoses. Depression was not a frequent diagnosis, but neurasthenia was a fairly common one. None of the referred patients had a diagnosis of alcoholism, drug abuse, or personality disorder. The authors compare these data with those of Western studies and discuss the possible factors influencing psychiatric consultation in China.

In vivo mapping of DNA topoisomerase II-specific cleavage sites on SV40 chromatin

The antitumor drug, m-AMSA (4'-(9-acridinylamino)-methanesulfon-m-anisidide), is known to interfere with the breakage-reunion reaction of mammalian DNA topoisomerase II by blocking the enzyme-DNA complex in its putative cleavable state. Treatment of SV40 virus infected monkey cells with m-AMSA resulted in both single- and double-stranded breaks on SV40 viral chromatin. These strand breaks are unusual because they are covalently associated with protein. Immunoprecipitation results suggest that the covalently linked protein is DNA topoisomerase II. These results are consistent with the proposal that the drug action in vivo involves the stabilization of a cleavable complex between topoisomerase II and DNA in chromatin. Mapping of these double-stranded breaks on SV40 viral DNA revealed multiple topoisomerase II cleavage sites. A major topoisomerase II cleavage site was preferentially induced during late infection and was mapped in the DNAase I hypersensitive region of SV40 chromatin.