Resonance Rayleigh scattering method for the determination of trace amounts of cadmium with iodide-basic triphenylmethane dye systems

In dilute phosphoric acid solution, cadmium (II) reacts with a large excess of I- to form [CdI4]2- which reacts further with basic triphenylmethane dyes such as crystal violet (CV), ethyl violet (EV), methyl violet (MV), brilliant green (BG) or malachite green (MG) to form an ion-association complex. This results in a significant enhancement of resonance Rayleigh scattering (RRS) intensity and the appearance of new RRS spectra. The characteristics of RRS spectra of the ion-association complexes, the influencing factors and the optimum conditions of these reactions have been investigated. The intensity of RRS is directly proportional to the concentration of cadmium from 0 to 60 ng mL(-1) for EV and MV systems, 0 to 80 ng mL(-1) for CV system, and 0 to 100 ng mL(-1) for BG and MG systems. The methods exhibit high sensitivities and the detection limits for cadmium are between 0.35 and 2.00 ng mL(-1) depending on the different reaction systems. The new RRS method was applied to the direct determination of traces of cadmium in pure zinc and synthetic water samples.

Instrumentation and calibration protocol for imaging dynamic features in dense-scattering media by optical tomography

Instrumentation is described that is suitable for acquiring multisource, multidetector, time-series optical data at high sampling rates (up to 150 Hz) from tissues having arbitrary geometries. The design rationale, calibration protocol, and measured performance features are given for both a currently used, CCD-camera-based instrument and a new silicon-photodiode-based system under construction. Also shown are representative images that we reconstructed from data acquired in laboratory studies using the described CCD-based instrument.

Pacing stress echocardiography: an alternative to pharmacologic stress testing

OBJECTIVES

We sought to evaluate the diagnostic accuracy and feasibility of bedside pacing stress echocardiography (PASE) as a potential substitute for pharmacologic stress echocardiography in patients admitted to the hospital with new-onset chest pain or worsening angina pectoris.

BACKGROUND

Accurate and rapid noninvasive identification and evaluation of the extent of coronary artery disease (CAD) is essential for optimal management of these patients.

METHODS

Bedside transthoracic stress echocardiography was performed in 54 consecutive patients admitted to a community hospital with new-onset chest pain, after acute myocardial infarction had been excluded. We used 10F transesophageal pacing catheters and a rapid and modified pacing protocol. The PASE results were validated in all patients by coronary angiography performed within 24 h of the test. Significant CAD was defined as > or =75% stenosis in at least one major epicardial coronary artery.

RESULTS

The sensitivity of PASE for identifying patients with significant CAD was 95%, specificity was 87% and accuracy was 92%. The extent of significant CAD (single- or multivessel disease) was highly concordant with coronary angiography (kappa = 0.73, p<0.001). Pacing stress echocardiography was well tolerated, and only 4% of the patients had minor adverse events. The mean rate-pressure product at peak pacing was 22,313+/-5,357 beats/min per mm Hg, and heart rate >85% of the age-predicted target was achieved in 94% of patients. The average duration of the bedside PASE test, including image interpretation, was 38+/-6 min.

CONCLUSIONS

Bedside PASE is rapid, tolerable and accurate for identification of significant CAD in patients admitted to the hospital with new-onset chest pain or worsening angina pectoris.

Genetic heterogeneity and molecular epidemiology of GB virus C/hepatitis G virus in China

OBJECTIVE

The inter- and intrapatient genetic variation of GB virus C (GBV-C)/hepatitis G virus (HGV) was investigated to characterize the molecular epidemiologic profile of GBV-C/ HGV infection in China, an area endemic for viral hepatitis. The intrapatient variation of hepatitis C virus (HCV) from the same patients was compared to that of GBV-C/HGV.

STUDY DESIGN/METHODS

GB virus C/HGV RNA was amplified by polymerase chain reaction in 88 patients with hepatitis C, hepatitis B or presumed non-A-E hepatitis from three cities in China. Five clones of the GBV-C/HGV NS3 region were sequenced from each GBV-C/HGV RNA-positive patient. The corresponding region of HCV was also sequenced from patients co-infected with HCV. Representative sequences of the GBV-C/HGV NS3 region from each patient and those of isolates from other continents were subjected to phylogenetic analyses.

RESULTS

GB virus C/HGV was detected in 22 (25.25%) of 88 patients: 9 (21.4%) of 42 patients with presumed non-A-E hepatitis, 10 (27.7%) of 36 patients with hepatitis C, 3 (30.0%) in 10 patients with hepatitis B and C, and in none of 60 volunteer blood donors. The extent of nucleotide variation was less between Chinese isolates (2.4-17%; median, 10.4%) than between Chinese isolates and seven isolates from outside China (10.5-19.5%; median, 15.3%). Intrapatient sequence variation ranged from 0 to 1.75%, with a mean of 0.57 +/- 0.51%. Phylogenetic analysis grouped most Chinese isolates into four geographically specific clusters with a divergence of 10% to 16% from each other. The ratio of nonsynonymous to synonymous substitutions of GBV-C/HGV (Ka/Ks 0.019) was much lower than for HCV (0.071) in the same patients.

CONCLUSION

Chinese isolates of GBV-C/HGV are genetically distinct. There are local strains as well as shared strains between different locales. The extent of amino acid sequence conservation suggests strong selection against nonsynonymous substitutions in the GBV-C/HGV genome.

[The neutralizing effect of histidine-rich-polypeptides on LPS from suspected periodontal pathogens]

OBJECTIVE

Human parotid histidine-rich-polypeptides (HRPs) are a family of lowmolecular-weight, cationic polypeptides. HRP-1, HRP-3 and HRP-5 comprise 85%-90% of the total HRPs and are called major HRPs. There were many researches indicating the antimicrobial activities of HRPs. Recently, HRPs were reported to have an inhibitory action on the lipopolysaccharide (LPS) of E. coli, with HRP-5 being the most effective one among the three major HRPs. Since the LPS of oral gram-negative bacteria is thought to be one of the important etiological factors during the development of periodontal diseases, our experiment was aimed to investigate the neutralizing effect of human parotid HRP-5 on the LPS of anaerobic suspected periodontal pathogens, which have different chemical structures and biological activities compared with LPS of aerobic E. coli.

METHODS

By using of preparative acid urea polyacrylamide gel electrophoresis (AU-PAGE), HRP-5 was purified from parotid saliva collected from healthy adults. Two stains of suspected periodontal pathogens, Porphyromonas gingivalis (P.g, 47-A) and Fusobacterium nuceatum (F. n, separated from subgingival plaque of a patient with adult periodontitis) were mass cultured. After harvested in the midlogarithmic phase, they were washed and lyophilized. The LPS of dried bacteria were extracted by the modified Westphal hot phenol-water procedures and purified by the enzyme digestion plus ultracentrifugation. Limulus test was applied to test the neutralizing effect of HRP-5 on the LPS-induced gelation of Limulus amoebocyte lysate. In brief, the standard LPS of E. coli, or extracted LPS of P. g or F. n, was preincubated with HRP-5 in a tube separately in room temperature for 10 minutes. Then the reagent of Limulus amoebocyte lysate was added in all the tubes, continued the incubation in 37 degrees C for one hour. After that, the gelation level of every tube was observed.

RESULTS

LPS extracted from P. g and F. n both showed good purity and strong activities to induce gelation of Limulus amoebocyte lysate. The gelation induced by LPS (1 ng/ml) of these two anaerobic suspected periodontal pathogens were weakly inhibited by HRP-5 (10 micrograms/ml), similar to that observed with standard LPS of E. coli. To get a complete neutralizing effect on LPS, it may be important to increase the concentration of HRP-5.

CONCLUSION

It appeared that HRPs could neutralize the endotoxic properties of LPS of suspected periodontal pathogens, therefore may contribute to periodontal health. The present investigation further confirmed that HRPs are important components of the host non-immune defense system.

FLP-mediated recombination for use in hybrid plant production

We have studied the feasibility in Arabidopsis of using a site-specific recombination system FLP/FRT, from the 2 microm plasmid of yeast, for making plant hybrids. Initially, Arabidopsis plants expressing the FLP site-specific recombinase were crossed with plants transformed with a vector containing kanamycin-resistance gene (npt) flanked by FRT sites, which also served to separate the CaMV35S promoter from a promoterless gusA. Hybrid progeny were tested for excision of the npt gene and the positioning of 35S promoter proximal to gusA. GUS activity was observed in the progeny of all crosses, but not in the progeny derived from the self-pollinated homozygous parents. We then induced male sterility in Arabidopsis plants using the antisense expression of a pollen- and tapetum-specific gene, bcp1, flanked by FRT sites. Upon cross-pollination of flowers on the same male-sterile plants with pollen from FLP-containing plants, viable seeds were produced and the progeny hybrid plants developed normally. Molecular analyses revealed that the antisense expression cassette of bcp1 had been excised in these plants. These results show for the first time that a site-specific recombinase can be used to restore fertility in male-sterile plants, providing an alternative method for the production of hybrid seeds and plants.

A dual role for zinc fingers in both DNA binding and zinc sensing by the Zap1 transcriptional activator

The Zap1 transcriptional activator of Saccharomyces cerevisiae controls zinc homeostasis. Zap1 induces target gene expression in zinc-limited cells and is repressed by high zinc. One such target gene is ZAP1 itself. In this report, we examine how zinc regulates Zap1 function. First, we show that transcriptional autoregulation of Zap1 is a minor component of zinc responsiveness; most regulation of Zap1 activity occurs post-translationally. Secondly, nuclear localization of Zap1 does not change in response to zinc, suggesting that zinc regulates DNA binding and/or activation domain function. To understand how Zap1 responds to zinc, we performed a functional dissection of the protein. Zap1 contains two activation domains. DNA-binding activity is conferred by five C-terminal C(2)H(2) zinc fingers and each finger is required for high-affinity DNA binding. The zinc-responsive domain of Zap1 also maps to the C-terminal zinc fingers. Furthermore, mutations that disrupt some of these fingers cause constitutive activity of a bifunctional Gal4 DNA-binding domain-Zap1 fusion protein. These results demonstrate a novel function of Zap1 zinc fingers in zinc sensing as well as DNA binding.

Transthoracic stress echocardiography with transesophageal atrial pacing for bedside evaluation of inducible myocardial ischemia in patients with new-onset chest pain

To date, there are no data on the feasibility and accuracy of bedside pacing stress echocardiography in patients admitted to the hospital with new-onset chest pain or unstable angina. We evaluated the feasibility of pacing stress echocardiography and examined its correlation with myocardial perfusion stress scintigraphy (rest thallium-201/stress technetium-99m sestamibi dual-isotope myocardial perfusion single-photon emission computerized tomography) performed within 24 hours of the pacing stress echocardiography test. We studied 70 consecutive patients after acute myocardial infarction had been excluded. The bedside pacing stress echocardiography test was performed with 10Fr transesophageal pacing catheters. We found pacing stress echocardiography to be feasible and safe (3% minor adverse event rate) at the patients' bedside. Target heart rate of >85% of the age-predicted heart rate was achieved in 96% of patients, and the mean rate-pressure product was 22,644 +/- 4,520 beats/min/mm Hg. The mean duration of the bedside pacing stress echocardiography test including technical preparations and image interpretation was 41 +/- 7 minutes. Pacing stress echocardiography and myocardial perfusion stress scintigraphy correlated well for identification or exclusion of inducible myocardial ischemia in 63 of 70 patients (90%) (kappa 0.81, p <0.001). The extent of inducible myocardial ischemia by vascular territories correlated with myocardial perfusion stress scintigraphy in 52 of 70 patients (74%) (kappa 0.6, p <0.001). We conclude that bedside pacing stress echocardiography is feasible and safe, and highly correlates with myocardial perfusion stress scintigraphy for identifying inducible myocardial ischemia in patients with new onset of chest pain or unstable angina.

[Total cavo-pulmonary connection for complex congenital heart disease]

Between April 1994 and January 1997, 10 patients with complex congenital heart disease were treated with total cavo-pulmonary connection(TCPC). They included 7 males and 3 females, aged 2-17 years(mean 10.1 years). These cases were single ventricle in 5, tricuspid atresia in 4, severe Ebstein anomaly in 1. For construction of the right atrial lateral tunnel, Gore-Tex patch was used in 9 cases and autologous right atrial wall in another, 4 of the 10 patients underwent TCPC without aortic crossclamping. There were no operative deaths. The follow-up is 2-36 months(mean 12.3 months). All of these patients did well and were in NYHA class I. The advantages, operative indication and technique of TCPC and the experience of improvement of surgical results are briefly discussed in this paper.

Mapping the DNA binding domain of the Zap1 zinc-responsive transcriptional activator

The Zap1 transcriptional activator of Saccharomyces cerevisiae plays a major role in zinc homeostasis by inducing the expression of several genes under zinc-limited growth conditions. This activation of gene expression is mediated by binding of the protein to one or more zinc-responsive elements present in the promoters of its target genes. To better understand how Zap1 functions, we mapped its DNA binding domain using a combined in vivo and in vitro approach. Our results show that the Zap1 DNA binding domain maps to the carboxyl-terminal 194 amino acids of the protein; this region contains five of its seven potential zinc finger domains. Fusing this region to the Gal4 activation domain complemented a zap1Delta mutation for low zinc growth and also conferred high level expression on a zinc-responsive element-lacZ reporter. In vitro, the purified 194-residue fragment bound to DNA with a high affinity (dissociation constant in the low nanomolar range) similar to that of longer fragments of Zap1. Furthermore, by deletion and site-directed mutagenesis, we demonstrated that each of the five carboxyl-terminal zinc fingers are required for high affinity DNA binding.

Noninvasive, transthoracic, low-frequency ultrasound augments thrombolysis in a canine model of acute myocardial infarction

BACKGROUND

Limitations of coronary thrombolysis include the time to reperfusion, patency rate, and bleeding. We evaluated the use of noninvasive transcutaneous ultrasound to augment coronary thrombolysis.

METHODS AND RESULTS

In 24 dogs, a thrombotic occlusion of the left anterior descending coronary artery was induced and documented by 12-lead ECG and coronary angiography. After >/=60 minutes of occlusion, tissue-type plasminogen activator (t-PA; 1.42 mg/kg) was given intravenously over 90 minutes. A total of 12 of the 24 dogs had concomitant transcutaneous application of low-frequency ultrasound (27 kHz) over the chest. At 90 minutes, the mean TIMI grade flow in the t-PA alone group was 0.92+/-1.4 compared with 2. 42+/-1.9 in the t-PA plus ultrasound group (P=0.006). TIMI 2 to 3 flow was present in 4 of 12 cases receiving t-PA alone compared with 10 of 12 cases receiving t-PA plus ultrasound (P=0.003). At 180 minutes, mean TIMI grade flow was 0.75+/-1.4 in the t-PA alone group versus 2.58+/-0.9 in the t-PA plus ultrasound group (P=0.001). Pathological examination confirmed the angiographic patency rate and did not reveal injury secondary to ultrasound in the skin, soft tissues, heart, or lungs.

CONCLUSIONS

In vivo, the noninvasive transthoracic application of low-frequency ultrasound (1) greatly augments the efficacy of t-PA-mediated thrombolysis, (2) seems safe, and (3) has substantial potential as a noninvasive adjunct to improve coronary patency without increasing the risk of bleeding.

Deletion of the murine Duffy gene (Dfy) reveals that the Duffy receptor is functionally redundant

All of the antigenic determinants of the Duffy blood group system are in a glycoprotein (gp-Fy), which is encoded by a single-copy gene (FY) located on chromosome 1. gp-Fy is also produced in several cell types, including endothelial cells of capillary and postcapillary venules, the epithelial cell of kidney collecting ducts, lung alveoli, and the Purkinje cells of the cerebellum. This protein, which spans the cell membrane seven times, is a member of the superfamily of chemokine receptors and a malarial parasite receptor. The mouse Duffy gene (Dfy) homolog of human FY is also a single-copy gene, which maps in a region of conserved synteny with FY and produces a glycoprotein with 60% homology to the human protein. The mouse Duffy-like protein also binds chemokines. To study the biological role of gp-Fy, we generated a mouse strain in which Dfy was deleted. These homozygous Dfy(-/-) mice were indistinguishable in size, development, and health from wild-type and heterozygous littermates. We also examined components of the immune system and found no differences in lymph nodes or peripheral blood leukocyte levels between knockout and wild-type mice. The gross and histological anatomy of the thymus, spleen, lung, and brain showed no significant differences between mutants and wild-type mice. There was no indication of an overall difference between the knockout and wild-type mice in systematic neurological examinations. The only significant difference between Dfy(-/-) and Dfy(+/+) mice that we found was in neutrophil migration in peritoneal inflammations induced by lipopolysaccharide and thioglycolate. In mice homozygous for the deletion, there was less neutrophil recruitment into the peritoneal cavity and neutrophil influx in the intestines and lungs than in wild-type mice. Despite this, the susceptibility to Staphylococcus aureus infection was the same in the absence and in the presence of gp-Fy. Our results indicate that gp-Fy is functionally a redundant protein that may participate in the neutrophil migratory process.

The prostate apoptosis response-4 protein participates in motor neuron degeneration in amyotrophic lateral sclerosis

Prostate apoptosis response-4 (Par-4), a protein containing a leucine zipper domain within a death domain, is up-regulated in prostate cancer cells and hippocampal neurons induced to undergo apoptosis. Here, we report higher Par-4 levels in lumbar spinal cord samples from patients with amyotrophic lateral sclerosis (ALS) than in lumbar spinal cord samples from neurologically normal patients. We also compared the levels of Par-4 in lumbar spinal cord samples from wild-type and transgenic mice expressing the human Cu/Zn-superoxide dismutase gene with a familial ALS mutation. Relative to control samples, higher Par-4 levels were observed in lumbar spinal cord samples prepared from the transgenic mice at a time when they had hind-limb paralysis. Immunohistochemical analyses of human and mouse lumbar spinal cord sections revealed that Par-4 is localized to motor neurons in the ventral horn region. In culture studies, exposure of primary mouse spinal cord motor neurons or NSC-19 motor neuron cells to oxidative insults resulted in a rapid and large increase in Par-4 levels that preceded apoptosis. Pretreatment of the motor neuron cells with a Par-4 antisense oligonucleotide prevented oxidative stress-induced apoptosis and reversed oxidative stress-induced mitochondrial dysfunction that preceded apoptosis. Collectively, these data suggest a role for Par-4 in models of motor neuron injury relevant to ALS.

[Clinical analysis of early complications in 132 low body weight infants performed open-heart surgery]

A clinical analysis of early complications in 132 low body weight infants undergoing open-heart surgery is reported. There were a higher risk of early complication associated with severe illness and/or experienced a longer duration time of cardiopulmonary bypass and endotracheal tube. The total complication rate was 42.4% and the major three complications were low cardiac output, acute respiratory distress syndrome and problems from endotracheal tube (occlusion and/or in proper position of tube). The author emphasized the importance of management of endotracheal tube after operation.

Compromised kidney graft rejection response in Vervet monkeys after withdrawal of immunosuppressants tacrolimus and sirolimus

BACKGROUND

In nonprimates, organ allografts are often not rejected after withdrawal of immunosuppression. In this study, we examined whether such a phenomenon also occurs in primates.

METHODS

Vervet monkeys were transplanted with renal allografts and treated for 60 days with tacrolimus, or tacrolimus plus sirolimus. The drugs were totally withdrawn on day 61. The survival of the monkeys was monitored, and their response to donor- or third party-derived alloantigens was examined in vivo and in vitro.

RESULTS

The majority (80-100%) of the grafts survived for at least additional 30 days with no signs of acute rejection. The compromised rejection is donor-specific, because recipient monkeys failed to reject a donor-derived skin graft, but a third-party skin graft was rejected. In vitro mixed lymphocyte reaction and interleukin-2 production in the mixed lymphocyte reaction between the recipients and their donors or between the recipients and a third party had no discernable patterns, and thus did not reflect the in vivo status of the immune system. Although the recipients could not reject the graft acutely after drug withdrawal, the kidney grafts and the donor-derived skin grafts had pathological findings of chronic rejection.

CONCLUSIONS

The rejection response of the monkeys to an established graft after withdrawal of immunosuppression is compromised. The compromised rejection is specific and is not due to a permanent alteration of the immune system by the initial drug treatment. The allografts are not inert but have low levels of interaction with the recipient immune system.

Evaluation of Z-(R,R)-IQNP for the potential imaging of m2 mAChR rich regions of the brain and heart

Alterations in the function or density of the m2 muscarinic (mAChR) subtype have been postulated to play an important role in various dementias such as Alzheimer's disease. The ability to image and quantify the m2 mAChR subtype is of importance for a better understanding of the m2 subtype function in various dementias. Z-(R)-1-Azabicyclo[2.2.2]oct-3-y (R)-alpha-hydroxy-alpha-(1-iodo-1-propen-3-yl)-alpha-phenylacetate (Z-(R,R)-IQNP) has demonstrated significant uptake in cerebral regions that contain a high concentration of m2 mAChR subtype in addition to heart tissue. The present study was undertaken to determine if the uptake of Z-(R,R)-IQNP in these regions is a receptor mediated process and to identify the radiospecies responsible for binding at the receptor site. A blocking study demonstrated cerebral and cardiac levels of activity were significantly reduced by pretreatment (2-3 mg/kg) of (R)-3-quinuclidinyl benzilate, dexetimide and scopolamine, established muscarinic antagonists. A direct comparison of the cerebral and cardiac uptake of [I-125]-Z-(R,R)-IQNP and [I-131]-E-(R,R)-IQNP (high uptake in ml, m4 rich mAChR cerebral regions) demonstrated Z-(R,R)-IQNP localized to a higher degree in cerebral and cardiac regions containing a high concentration of the m2 mAChR subtype as directly compared to E-(R,R)-IQNP. In addition, a study utilizing [I-123]-Z-(R,R)-IQNP, [I-131]-iododexetimide and [I-125]-R-3-quinuclidinyl S-4-iodobenzilate, Z-(R,R)-IQNP demonstrated significantly higher uptake and longer residence time in those regions which contain a high concentration of the m2 receptor subtype. Folch extraction of global brain and heart tissue at various times post injection of [I-125]-Z-(R,R)-IQNP demonstrated that approximately 80% of the activity was extracted in the lipid soluble fraction and identified as the parent ligand by TLC and HPLC analysis. These results demonstrate Z-(R,R)-IQNP has significant uptake, long residence time and high stability in cerebral and cardiac tissues containing high levels of the m2 mAChR subtype. These combined results strongly suggest that Z-(R,R)-IQNP is an attractive ligand for the in vivo imaging and evaluation of m2 rich cerebral and cardiac regions by SPECT.

The proteasome controls the expression of a proliferation-associated nuclear antigen Ki-67

The proteasome is a protease complex responsible for rapid, selective, and irreversible removal of regulatory proteins, as well as many other cellular proteins. In this study, we have demonstrated that a proliferation-associated nuclear protein Ki-67 depended on the proteasome for its rapid degradation. A proteasome-specific inhibitor lactacystin augmented Ki-67 protein levels in pancreatic cancer BxPC-3 cells while repressed the level of steady-state Ki-67 mRNA. Inhibition of the proteasome also led to accumulation of two CDK inhibitors p27(kip1) and p21(cip1) in the BxPC-3 cells. Failed reduction of Ki-67 protein and enhanced levels of the two CDK inhibitors are likely contributing factors for the suppressed BxPC-3 proliferation after proteasome inhibition.

Ultrasound has synergistic effects in vitro with tirofiban and heparin for thrombus dissolution

Previous studies have shown synergism between ultrasound and thrombolytic agents or microbubbles on blood clot dissolution. It has not been investigated whether heparin or glycoprotein IIb/IIIa blockers enhance clot lysis by ultrasound. We compared the blood clot dissolution effect of saline, heparin, tissue plasminogen activator (tPA), tirofiban, and an echocardiographic contrast media (Optison) without and with ultrasound application. Human blood clots from four donors, 2 to 4 hours old, were cut into 200- to 400-mg sections, weighed, and immersed for 2 minutes in 1 L of normal saline 0.9% solution containing either heparin 1000 U, tirofiban 150 microg, tPA 20 mg, Optison 0.5 mL, or normal saline alone. Clots were randomized to 2 minutes ultrasound application or immersion alone without ultrasound. Ultrasound was applied with a 19.5 KHz catheter. After treatment, the clots were weighed, and the absolute and percent difference in weight was calculated. Immersion in heparin, tirofiban, and tPA without ultrasound did not augment clot disruption relative to normal saline alone. Immersion in Optison (p = 0.07) tended to result in less lysis than saline alone. Ultrasound enhanced clot dissolution compared to immersion alone with: saline (48.1+/-15.3% vs. 26.0+/-13.8%, p<0.0000002); heparin (60.8+/-17.5% vs. 30.8+/-15.1%, p = 0.000001); tirofiban (61.8+/-13.6% vs. 30.1+/-12.2%, p<0.0000001); tPA (53.1+/-15.3% vs. 30.2+/-11.5%, p<0.000002); and Optison (47.8+/-16.0% vs. 18.4+/-11.5%, p<0.0000001). The combination of tirofiban with ultrasound, as well as heparin with ultrasound, was associated with a significant augmentation of clot dissolution compared with the saline plus ultrasound group (p = 0.002, 0.013, respectively). Ultrasound with tPA or with Optison had no significant augmentation of clot dissolution over the ultrasound + saline effect. This in vitro study of catheter-delivered high-intensity low-frequency ultrasound demonstrates that: (1) tirofiban and heparin, as well as perfluorocarbon microbubbles, augment clot dissolution by ultrasound; (2) augmentation of clot dissolution is evident even after only brief exposure of ultrasound and the drug studied.

Transcription initiation at the TATA-less spliced leader RNA gene promoter requires at least two DNA-binding proteins and a tripartite architecture that includes an initiator element

Eukaryotic transcriptional regulatory signals, defined as core and activator promoter elements, have yet to be identified in the earliest diverging group of eukaryotes, the primitive protozoans, which include the Trypanosomatidae family of parasites. The divergence within this family is highlighted by the apparent absence of the "universal" transcription factor TATA-binding protein. To understand gene expression in these protists, we have investigated spliced leader RNA gene transcription. The RNA product of this gene provides an m(7)G cap and a 39-nucleotide leader sequence to all cellular mRNAs via a trans-splicing reaction. Regulation of spliced leader RNA synthesis is controlled by a tripartite promoter located exclusively upstream from the transcription start site. Proteins PBP-1 and PBP-2 bind to two of the three promoter elements in the trypanosomatid Leptomonas seymouri. They represent the first trypanosome transcription factors with typical double-stranded DNA binding site recognition. These proteins ensure efficient transcription. However, accurate initiation is determined an initiator element with a a loose consensus of CYAC/AYR (+1), which differs from that found in metazoan initiator elements as well as from that identified in one of the earliest diverging protozoans, Trichomonas vaginalis. Trypanosomes may utilize initiator element-protein interactions, and not TATA sequence-TATA-binding protein interactions, to direct proper transcription initiation by RNA polymerase II.

Dual-label studies with [125I]-3(R)/[131I]-3(S)-BMIPP show similar metabolism in rat tissues

Biodistribution studies with the radioiodinated 3(R)- and 3(S)-isomers of 15-(p-iodophenyl)-3-methylpentadecanoic acid (BMIPP) in rats have shown that 3(R)-BMIPP has 20%-25% higher heart uptake than 3(S)-BMIPP (15-180 min). In contrast, the 3(S)-isomer has slightly higher liver uptake, and uptake in other tissues examined is similar.

METHODS

To evaluate the possible differences in metabolic fate of the two isomers, a mixture of [125I]-3(R)/[131I]-3(S)-BMIPP was administered to fasted female Fisher rats. Groups of rats (3 per group) were killed 15, 60 and 180 min after administration. Urine and feces were collected from a fourth group (n = 3) over 7 d. Samples of blood, heart, liver, lungs, kidney and urine were Folch extracted. The distributions of 125I and 131I in the organic (lipid), aqueous and pellet samples were determined. The lipid samples as well as the organic fractions from base-hydrolyzed triglyceride (TG) fractions and acid-hydrolyzed urine samples were then analyzed by thin-layer chromatography (TLC) and high-performance liquid chromatography (HPLC).

RESULTS

The relative distributions of 125I and 131I in the lipid, aqueous and pellet samples were similar for both isomers. Distribution of 125I and 131I in the various components of the lipid extracts observed by TLC (hexane:ether:HOAc, 70:30:1) was also similar, with principal incorporation into the free fatty acid (FFA) and TG pools. HPLC analyses (C18) of the FFA fraction showed similar 125I and 131I profiles, corresponding to BMIPP, and the alpha-methyl-C14 (14-(p-iodophenyl)-3-(R,S)-methyltetradecanoic acid) and C12, C10 and C6 carbon chain-length catabolites. By TLC, radioactive components of 125I and 131I in the urine had the same TLC mobility as hippuric acid. HPLC analyses (C18) of acid-hydrolyzed urine gave a single 125I/131I component with the same relative retention time as 2-(p-iodophenyl)acetic acid, which is the final alpha/beta-oxidative BMIPP catabolite. Unexpectedly, HPLC of lipids from base-hydrolyzed TG from the heart tissue showed 125I/131I components with the same retention times as shorter-chain fatty acids, similar to the FFA fraction, with only low levels of activity detected in BMIPP.

CONCLUSION

These results show that 3(R)-BMIPP and 3(S)-BMIPP are metabolized similarly in rat tissues and that higher myocardial extraction observed for 3(R)-BMIPP may reflect differences in the relative membrane transport of the two isomers.

[Studies on chemical constituents of the roots of Gypsophila oldhamiana Miq]

OBJECTIVE

To separate compounds from the root of Gypsophila oldhamiana.

METHOD

Chemical and chromatographic methods were used to separate the compounds. IR, MS, NMR were used to determine the structures of compounds.

RESULT

Compound pentacosanoic acid, lacceroic acid, beta-sitosterol, alpha-spinasterol, daucosterol and sucrose were identified.

CONCLUSION

All the above compounds were obtained from this genus for the first time.

[Quantitative determination of mass ratio of additives in special super-high pressure hydraulic oil]

Two additives, phenol, 2,6-bis(1,1-dimethylethyl)-4-methyl- and triphenyl phosphate with mass ratio of less than one thousandth in special super-high pressure hydraulic oil were determined by GC-MS. Tributyl phosphate ester was used as internal standard. The correction factor of each additive was determined before analysis. Each sample was analysed for 5 times to get good precision. It is satisfactory to use SIM as the detecting mode, and the CVs of correction factors and mass ratio were about 5%. The problems of how to select the monitoring ion in SIM mode and the sample size required are discussed in this paper. This method is satisfactory in analyzing low mass ratio constituents in a mixture.

Inhibition of DNA synthesis in isolated human endometrial cells by a levonorgestrel-releasing intrauterine device

OBJECTIVE

To estimate the effect of an intrauterine device (IUD) releasing 20 micrograms levonorgestrel (LNG) per 24 hours on DNA synthesis in human endometrial cells before and after 12 months of use.

STUDY DESIGN

Endometrial specimens were collected from the anterior or posterior wall of the miduterus from 6 females on cycle day 10-12 before insertion of the IUD and after 12 months of use.

RESULTS

Previous results from our group did not reveal any influence on endometrial DNA cell content when a levonorgestrel IUD releasing 2 micrograms/24 h was used for 12 months in a group of fertile females. In this study, the IUD release rate, 20 micrograms LNG/24 h, was statistically significantly different from the results in the previous studies. The effect of the levonorgestrel IUD on endometrial proliferation was dose dependent, and a significant correlation could be found between continuous exposure to LNG and inhibition of DNA synthesis in endometrial cells.

CONCLUSION

Inhibition of proliferative activity in endometrial cells seems to be reflected by a decrease in DNA synthesis per cell nucleus and contributes to the clinical performance of the LNG-releasing IUD.

Improved radioiodination of 1,2-dipalmitoyl-3-IPPA via a tributyltin intermediate

1,2-Palmitoyl-3-[15-(4-iodophenyl)pentadecan-3-oyl]-rac-glycerol (MIPAG) is a new agent for the clinical evaluation of pancreatic lipase activity and has demonstrated promise in preliminary clinical studies with patients affected with pancreatic insufficiency. Iodine-131-MIPAG was initially prepared via thallium-iodide displacement. Because of the need for a simple method which is amendable for the routine clinical use of MIPAG we have investigated the preparation and radioiodination of MIPAG utilizing the tributyltin precursor, 1,2-palmitoyl-3-[15-(4-tributylstannylphenyl)pentadecan-3-oy l]-rac-glycerol (TBT-MIPAG, 2). Compound 2 was prepared via the condensation of 1,2-palmitoyl-rac-glycerol with 15-(4-tributylstannylphenyl)pentadecanoic acid (TBT-PPA) prepared from 4-bromophenylacetylene. Electrophilic radioiodination using peracetic acid with sodium iodide-125 in ethanol at 80 degrees C for 60 min afforded I-125-MIPAG in 65.9% (+/- 11.5%) yield and radiochemical purity of 94% (+/- 3.0%) after C-18 Sep-Pak purification (n = 6). This improved method for radioiodination utilizing TBT-MIPAG now provides radioiodinated MIPAG for routine clinical evaluation.