Alboaggregin-B: a new platelet agonist that binds to platelet membrane glycoprotein Ib

A new protein, called alboaggregin-B (AL-B), has been isolated from Trimeresurus albolabris venom by ion-exchange chromatography. It agglutinated platelets without the need for Ca2+ or any other cofactor. The purified protein showed an apparent molecular mass on SDS-PAGE and gel filtration of about 23 kDa under nonreducing conditions. Ristocetin did not alter the binding of AL-B to platelets or affect AL-B-induced platelet agglutination. Agglutinating activity was not dependent on either proteolytic or lectin-like activity in AL-B. Binding analysis showed that AL-B bound to platelets with high affinity (Kd = 13.6 +/- 9.3 nM) at approximately 30,800 +/- 14,300 binding sites per platelet. AL-B inhibited the binding of labeled bovine von Willebrand factor (vWF) to platelets. Monoclonal antibodies against the 45-kDa N-terminal domain of platelet glycoprotein Ib inhibited the binding both of AL-B and of bovine vWF to platelets, and also inhibited platelet agglutination induced by AL-B and bovine vWF. Specific removal of the N-terminal domain of GPIb by treatment of the platelets with elastase or Serratia marcescens protease reduced the binding of labeled AL-B and bovine vWF to platelets and blocked platelet agglutination caused by both agonists. Monoclonal antibodies to glycoprotein IIb/IIIa, to bovine vWF, and to bovine serum albumin did not show any effect on the binding of AL-B to platelets. Our results indicate that the binding domain for AL-B on platelet GPIb is close to or identical with the one for vWF. This new protein may be a very useful tool for studying the interaction between platelets and vWF.

High-order stimulated Raman scattering and nonlinear red-shifted broadening in benzyl alcohol core optical fiber

Six orders of Stokes lines and the first-order anti-Stokes line were observed we believe for the first time, in a benzyl alcohol liquid core optical fiber. All the Stokes lines were asymmetrically broadened favoring the lower frequencies. The blue-shifted broadening was only a few percent of the amount of the red-shifted broadening, and the broadening of the fifty-order Stokes line was so broadened to exceed the characteristic Raman frequency shift, 1000 cm(-1), to connect with the sixth-order Stokes line. The asymmetric broadening was discussed to be mainly due to the effect of the stimulated Rayleigh wing scattering.

The tissue-specific mammalian transcription factor, Pit-1, activates transcription in Saccharomyces cerevisiae

Pit-1 is a tissue-specific transcription factor which binds to specific DNA sequences within 5' flanking regions of the PRL and GH genes and activates the transcription of these genes. Previous studies have shown that expression of Pit-1 is necessary to activate transcription from the PRL or GH promoters in heterologous mammalian cells. In the present study the ability of Pit-1 expression vectors to activate expression of reporter genes in Saccharomyces cerevisiae was examined. The test system used Pit-1 expression vectors and an indicator plasmid containing multiple copies of a Pit1-binding site as a replacement for the upstream activator sequence of the CYC1 promoter. Significant activation of indicator plasmid expression was detected only in the presence of functional Pit-1 expression vectors. In both mammalian and yeast cells, amino-terminal deletions of the Pit-1 coding sequence produced similar and gradual loss of transcriptional activation. This finding indicates that similar or identical regions of Pit-1 are required for transcriptional activation in mammalian and yeast cells. Although synthetic DNA elements containing multiple copies of a single Pit-1-binding site were sufficient to permit Pit-1-mediated transcriptional activation in both yeast and mammalian cells, DNA fragments representing the proximal region or distal enhancer region of the PRL gene were transcriptionally active only in mammalian cells. These studies establish the ability of Pit-1 to stimulate transcription in the absence of other tissue-specific factors and provide a system for further genetic studies of Pit-1 structure/function relationships as well as evaluation of target sequences necessary for Pit-1 action.

A capture-enzyme immunoassay for rapid diagnosis of transmissible gastroenteritis virus

Two enzyme immunoassays (EIA) were developed for the detection of swine transmissible gastroenteritis virus (TGEV) antigens. The 2 EIAs used the same detecting system, a monoclonal antibody conjugated to horseradish peroxidase, but used different capture systems including a monoclonal antibody (m-EIA) or a polyclonal antibody (p-EIA). The EIAs were compared with the fluorescent antibody test (FAT) and electron microscopy (EM) for the detection of TGEV in intestinal samples of experimentally inoculated gnotobiotic piglets and of conventional diarrheic pigs submitted for diagnosis. In the gnotobiotic piglets experimentally inoculated with TGEV, 81.8% (9/11) were positive for TGEV by p-EIA, and 72.7% (8/11) were positive by m-EIA. In comparison, 81.8% (9/11) were positive by FAT and 27.2% (3/11) were positive by EM. Three noninfected controls were negative by all tests. In the diagnostic samples, 86.0% (43/50) were positive by p-EIA, 68.2% (30/44) were positive by m-EIA, 28.6% (14/49) were positive by IFA, and 38.0% (19/50) were positive by EM. The m-EIA had a higher agreement with FAT and EM than did p-EIA.

Correlation between CD4 cell counts and cellular and plasma viral load in HIV-1-seropositive individuals

We conducted a study of 152 HIV-1-seropositive individuals in order to evaluate the possible correlations between the isolation of HIV from peripheral blood mononuclear cells or from plasma and CD4 cell counts. HIV was isolated from only 36% of plasma samples, and the isolation rate was closely related to CD4 cell counts, increasing gradually from 0% in subjects with greater than 800 x 10(6)/l CD4 cells to 88% in those with less than 100 x 10(6)/l CD4 cells. In contrast, HIV was isolated from 92% of cell samples (99% in subjects with less than 900 x 10(6)/l CD4 cells, 46% in those with CD4 counts greater than or equal to 900 x 10(6)/l). Since most cell samples were positive, a scoring method was designed to quantify the cellular viral load. The results obtained demonstrated that the cellular viral load was closely related to CD4 counts. We also found that the cellular viral load was higher in subjects with either positive plasma isolation or positive p24 antigenaemia. The measurement of the cellular viral load by this scoring method appears to be useful for the management of HIV-seropositive individuals and for the evaluation of therapeutic trials.

[The X-ray characteristic feature of the multiple primary malignant tumor of digestive tract]

A study on the multiple primary malignant tumor of digestive tract (MPMTDT) was made in the period of 1984-1988 in our hospital. Twenty five cases are reported in this paper. All of them were examined by X-ray, endoscopy, and proved to be MPMTDT by surgery and pathological examination. Twenty three cases were double primary tumors and 2 cases triple primary malignant tumors. The characteristic X-ray feature of the site of predilection and manifestation in primordial period of MPMTDT are described in this paper. These criteria are important for the early detection and selection of treatment of the tumors.

Vasodilatory action of endogenous atrial natriuretic factor in a rat model of chronic heart failure as determined by monoclonal ANF antibody

Elucidation of the role of (elevated) endogenous atrial natriuretic factor (ANF) in chronic heart failure has been hampered by a lack of specific inhibitors. We used a newly developed monoclonal antibody that has been shown to specifically block both exogenously and endogenously released ANF in vivo. For assessment of the vasodilatory action of ANF in chronic heart failure, either this antibody against ANF or ascites (control serum) was injected in rats with myocardial infarction and failure and in sham animals. Ascites did not alter central hemodynamics in either the sham or infarcted group. Antibody significantly increased right atrial pressure, left ventricular end-diastolic pressure, and systemic vascular resistance (SVR) in the infarction group but did not affect these variables in the sham group. Because renal blood flow, as measured by radioactive microspheres, decreased significantly in all four groups, probably due to nonspecific renal vasoconstrictor effects of the ascites, a separate group of infarcted animals was treated with purified ANF antibody (devoid of nonspecific effects) or mouse IgG as a control injection. In these animals, right atrial pressure increased from 1.1 +/- 0.7 to 2.6 +/- 0.7 mm Hg (p less than 0.001). Although SVR, renal blood flow velocity (measured by Doppler probe), and renal vascular resistance did not change in the infarcted animals after administration of purified ANF antibody, a significant correlation was found between baseline plasma ANF values and the change in SVR exerted by purified ANF antibody (r = 0.758, p less than 0.02, n = 9); that is, SVR increased in rats with high baseline plasma ANF (greater than 350 pg/ml), but decreased in animals with plasma ANF less than 200 pg/ml. These results suggest that moderately elevated endogenous plasma ANF levels in chronic heart failure do affect central hemodynamics, primarily by reducing venous pressure (e.g., by decreasing intravascular volume or by venous dilation). Arterial vasodilation, however, appears to emerge when plasma ANF is greatly increased.

Accessible magnetic resonance imaging

The cost of magnetic resonance imaging (MRI) is driven by magnetic field strength. Misperceptions as to the impact of field strength on performance have led to systems that are more expensive than they need to be. Careful analysis of all the factors that affect diagnostic quality lead to the conclusion that field strength per se is not a strong determinant of system performance. Freed from the constraints imposed by high-field operation, it is possible to exploit a varied set of opportunities afforded by low-field operation. In addition to lower costs and easier siting, we can take advantage of shortened T1 times, higher contrast, reduced sensitivity to motion, and reduced radiofrequency power deposition. These conceptual advantages can be made to coalesce onto practical imaging systems. We describe a low-cost MRI system that utilizes a permanent magnet of open design. Careful optimization of receiving antennas and acquisition sequences permit performance levels consistent with those needed for an effective diagnostic unit. Ancillary advantages include easy access to the patient, reduced claustrophobia, quiet and comfortable operation, and absence of a missile effect. The system can be sited in 350 sq ft and consumes a modest amount of electricity. MRI equipment of this kind can widen the population base than can access this powerful and beneficial diagnostic modality.

Clinical and experimental studies on paediatric pneumonia treated by lung easing tablets

197 cases of paediatric pneumonia from 2 hospitals were treated by Ning Fei Pian (NFP, the Lung Easing Tablets), a proprietary Chinese medicine for antipyresis, detoxication, blood invigoration, resolution of cough and phlegm; the control group was treated by penicillin, and the therapeutic results were comparable. Examinations of microcirculation and hemorrheology in the nailbed revealed improvements by NFP, which were conducive to the recovery of pneumonia. Electron-microscopically, the tablets also produced improvements in microcirculation, relief of lung edema, and the ratio of ventilation and blood flow.

Atrial natriuretic peptide in a rat model of cardiac failure. Atrial and ventricular mRNA, atrial content, plasma levels, and effect of volume loading

This study examined the relation between synthesis, atrial storage, and plasma levels of atrial natriuretic peptide (ANP), and it examined plasma ANP levels and hemodynamic output in response to volume expansion in a rat model of myocardial infarction and failure. Arterial ANP concentrations did not correlate linearly with infarct size, but they did show an abrupt increase when infarct size exceeded 30% of the left ventricle, similar to the abrupt increase of left ventricular end-diastolic pressure with infarct size greater than 30%. Consequently, a close relation was found between plasma ANP levels and left ventricular end-diastolic pressure (n = 23, r = 0.89, p less than 0.001). Atrial ANP content per gram of tissue but not ANP content per pair of atria was reduced in rats with large infarcts (greater than 40%, p less than 0.05 vs. control animals). ANP mRNA level per pair of atria (related to total atrial RNA), determined by liquid hybridization (controlled by northern blot analysis), was increased by 38% in infarcted rats (p less than 0.05 vs. controls), but the ratio of atrial ANP mRNA relative to atrial beta-actin mRNA levels was not increased. Right and left ventricular ANP mRNA level increased by 90% and 380%, respectively, far exceeding the concomitant increase in beta-actin mRNA (+26% in the left ventricle). Plasma ANP increased with volume loading in controls and rats with moderate infarcts but not in rats with large infarcts despite a similar increase in right atrial pressure (compared with control animals); thus, the relation of delta ANP/delta right atrial pressure exerted by volume loading decreased in rats with large infarcts. Similarly, the response of cardiac output and renal blood flow (determined by radioactive microspheres) to volume loading was attenuated in rats with large infarcts. Thus, in this model of chronic cardiac failure, the activation of the ANP system is closely coupled with the increase in intracardiac pressures without correlating linearly to the extent of myocardial loss. Second, in severe cardiac failure, additional stimulation such as volume loading may elicit only an attenuated ANP secretion response, for example, due to saturation of the ANP receptor sensing system or to a limited transformation rate of pro-ANP. Third, the increase in atrial ANP synthesis and the increase in atrial ANP gene expression seems limited; however, substantial specific ANP gene expression occurs in the ventricles, which, in turn, may contribute to increased plasma ANP levels in chronic heart failure.

Frequency domain compensation for inhomogeneous layers in ultrasound holography

A frequency-domain compensation method is presented that is based on the ultrasound holography B-scan (UHB) imaging principle. In an acoustic imaging system, the wavefront-angle-dependent distortions caused by any kind of known inhomogeneous reason can be compensated by this method. It is applied here in the frequency domain using the so-called rear-ranging operation for the longitudinal distortion and the multiplication of phase factors for the lateral distortion. The method is especially suitable for compensating different velocity layers in acoustic imaging systems. The results of both computer simulations and water-tank experiments are promising.

Pharmacokinetic and pharmacodynamic studies of piretanide in rabbits. IV. Effect of piretanide on the proximal tubules and the loop of Henle under a hydrated condition

In order to evaluate the effect of piretanide on the renal transport of water and osmotic substances, a clearance study was carried out in well hydrated rabbits. After intravenous bolus administration of piretanide, glomerular filtration rate, proximal tubular clearance and urine flow rate, as well as the pharmacokinetics of piretanide, were determined. A pharmacokinetic and pharmacodynamic link model which was developed in the previous paper was applied to the present experimental results. The results indicated that the effect of piretanide on the renal transport of water and osmotic substances in the hydrated rabbits was reasonably described by the model. The model analysis suggested that the diuretic response to piretanide was attributable to the inhibition of reabsorption of electrolytes in the proximal tubule, as well as in the loop of Henle.

Regeneration of tepals, stamens and ovules in explants from perianth of Hyacinthus orientalis L. importance of explant age and exogenous hormones

Regeneration of tepals, stamens and ovules from perianth explants of Hyacinthus orientalis L. in different developmental stages could be controlled by means of exogenous hormones. Perianth explants in a relatively early stage of development were competent for differentiation of tepals on Murashige and Skoog (MS) medium supplemented with 2 mg·1(-1) N(6)-benzylaminopurine (BAP) or zeatin and 0.1 mg·1(-1) 2,4-dichlorophenoxyacetic acid (2,4-D). Perianth explants in a later stage of development regenerated stamens and ovules, and marked difference was observed in the activity of BAP and zeatin in this regard. Zeatin stimulated more strongly stamen formation, while BAP enhanced ovule formation. Thus, stamens were formed when the explants were cultured for four months on medium with 2 mg·1(-1) BAP and 0.1 mg·1(-1) 2,4-D and then transferred to medium with 0.2 mg·1(-1) zeatin and 0.005 mg·1(-1) 1-naphthaleneacetic acid. On the other hand, differentiation of ovules occured in explants cultured for two weeks on the former medium and then transferred to medium with 0.1 mg·1(-1) BAP and 0.01 mg·1(-1) 2,4-D. Although ovule formation could also be obtained with 2 mg·1(-1) BAP alone, it was substantially enhanced by the presence of 0.1 mg·1(-1) 2,4-D in the medium in the early stages of culture. The results demonstrate the importance of both the developmental stage of the source organ from which explants are excised and of the hormone composition of the medium for the regeneration of different floral organs by perianth explants of Hyacinthus.

Prostaglandins involved in contractions by angiotensin II and bradykinin of isolated dog sphincter pupillae

1. The dog isolated sphincter pupillae contracted in response to acetylcholine, angiotensin II (AII), bradykinin, prostaglandins F2 alpha, D2, E2 and I2, and thionate thromboxane A2 (sTXA2) in a concentration-dependent manner. 2. AII-induced contractions were suppressed by treatment with saralasin, indomethacin, aspirin and diphloretin phosphate (DPP), a prostaglandin receptor antagonist. Contractions induced by bradykinin were also attenuated by indomethacin, aspirin and DPP. The amount of prostaglandin F2 alpha (PGF2 alpha) in the bathing media was increased approximately 41% following stimulation of the preparations by bradykinin. 3. The potency of contractile responses was in the order of PGF2 alpha greater than PGD2 = sTXA2 greater than PGE2 greater than arachidonic acid greater than PGI2. Contractions induced by PGF2 alpha were not significantly affected by treatment with indomethacin and ONO3708, an antagonist of the vasoconstrictor effect of prostaglandins, but appreciably attenuated by DPP. Arachidonic acid-induced contractions were inhibited by indomethacin. 4. Contractions of dog iris sphincter muscle in response to AII and bradykinin may be mediated via substances synthesized by cyclo-oxygenase from arachidonic acid. The distribution and nature of the prostaglandin receptors appear to differ markedly in iris sphincter and vascular smooth muscles.

Pharmacokinetic and pharmacodynamic studies of piretanide in rabbits. III. Sodium and potassium excretion under different hydrated conditions

The diuretic effect of piretanide, one of the loop diuretics, was investigated in three different hydrated conditions, namely well hydrated condition (treatment I), progressive hydropenic condition (treatment II) and complete hydropenic condition (treatment III) in rabbits. Each rabbit received intravenous administration of 1.5 or 15 mg/kg of piretanide and the urine flow rate, the excretion rates of Na and K, plasma concentrations of Na and K, urine osmolarity, plasma concentration of piretanide and urinary excretion of piretanide were determined after administration. The pharmacokinetics of piretanide was not influenced by the hydration state of the body, even in treatment III. The diuretic effect of piretanide evaluated by both urine flow rate (EH2O) and Na+K excretion rate (ENa+K), was significantly affected by the hydration state of the body. The more the hydropenic state was developed, less amounts of urine or electrolytes were excreted. A pharmacokinetic-pharmacodynamic link model which was proposed in the previous paper was applied to the present experimental results. The result indicated that the diuretic effect, even in the complete hydropenic condition (treatment III), was reasonably described by the model, with minor modifications. The time course of the excretion rate of K (EK) was not always in parallel with ENa+K, but was dependent on treatments. We found that the K-fraction, which was known as an indicator of the Na-K exchange reaction in the distal tubule, was quantitatively related to ENa+K, using a simple equation. Accordingly, the time course of EK was also calculated. The result also indicated that time courses of EK were described reasonably well by the model, regardless of treatments and doses.

Pharmacokinetic and pharmacodynamic studies of piretanide in rabbits. II: Effects on the proximal tubules and the loop of Henle

In order to clarify the effect of piretanide in the nephrons, pharmacokinetics and pharmacodynamics of piretanide were studied under a hydropenic condition in the rabbit. The hydropenic condition was developed by a simultaneous infusion of an antidiuretic hormone and hyperosmotic saline. Lithium was used as the indicator of the proximal sodium reabsorption. Plasma concentrations and urinary excretion rates of piretanide were not influenced by the hydration state of the body. The glomerular filtration rate (GFR) showed a long lasting decrease after piretanide administration; however, the urinary excretion rates of salts and water were increased prominently just after administration. The lithium clearance ratio, which was obtained by dividing the lithium renal clearance by GFR, indicated that piretanide inhibited the proximal reabsorption of sodium. The urine osmolarity after piretanide administration showed a significant decrease, and this indicated that the osmolarity of the renal medulla was also influenced by piretanide. From these observations, a model describing the transport of water and osmotic substances in the nephrons was constructed to calculate the effect of piretanide. The results indicated that the diuretic effect of piretanide in the hydropenic rabbit was reasonably described by the model. The model parameters obtained suggested that the site of action of piretanide in the proximal tubules might be in the peritubular side rather than inside the lumen, whereas the site of action in the loop of Henle might be inside the lumen.

Pharmacokinetic and pharmacodynamic studies of piretanide in rabbits. I. Effect of different hydrated conditions

The pharmacokinetics and pharmacodynamics of piretanide in rabbits were investigated. After intravenous administration, the plasma concentrations and the urinary excretion rates of piretanide, as well as the pharmacologic effects, were measured under two different hydrated conditions. In one experiment, the amount of the body fluid which was lost during diuresis was replaced by infusing Ringer's solution at exactly the same rate with the urine flow rate (treatment I). In another experiment, no compensatory infusion was made (treatment II). There was no appreciable difference between treatment I and II, as far as the plasma concentrations and urinary excretion rate were concerned. In spite of the similarities in the pharmacokinetic properties, the pharmacologic effects of piretanide were influenced considerably by the hydrated conditions of the body. The diuretic effect expressed as the excretion rate of the sum of urinary sodium and potassium was plotted against the corresponding urinary excretion rate of unchanged piretanide. The shape of the each graph showed a similar sigmoid like curve; however, the curve in treatment I was significantly shifted to the right compared to that in treatment II. This fact indicated that the pharmacologic effect of piretanide seemed to be modified by the contents of water and electrolytes in the body. The plasma concentrations and urinary excretion of piretanide were reasonably described by a linear three compartment open model.(ABSTRACT TRUNCATED AT 250 WORDS)

Aminoterminal procollagen III peptide elevation in alcoholics who are selenium and vitamin E deficient

Serum aminoterminal procollagen III peptide (PIIIP) was measured in 36 alcoholic subjects. There was a significant elevation of PIIIP in subjects with proven liver disease (median 17.5 ng/ml, n = 24) compared to those without liver disease (median 4.7 ng/ml, n = 12). Those subjects with raised serum transaminase values (AST) had elevated PIIIP values (median 13.7 ng/ml, n = 22) compared to those with normal transaminase values (median 3.7 ng/ml, n = 14). In those alcoholic subjects who were deficient in both selenium and vitamin E there was a significant elevation (p less than 0.01) of PIIIP values (median 26.4 ng/ml, n = 7) compared to subjects with normal levels (median 7 ng/ml, n = 11). Subjects deficient in selenium alone had PIIIP values in an intermediate range. Selenium and vitamin E, as important free radical scavengers, may protect the liver in alcoholic subjects from oxidative damage leading to hepatic fibrosis.

Mutagenicity of benzidine and related compounds employed in the detection of hemoglobin

Seven compounds commonly used as chromagens for the detection of hemoglobin and its derivatives have been assayed for mutagenicity employing the Salmonella/mammalian microsome test. Three of these compounds, benzidine, o-dianisidine, and o-tolidine, were shown to be mutagenic. Since benzidine and o-tolidine are already known to be carcinogens, there is a high probability that o-dianisidine will also prove to be a carcinogen. Four compounds tested with this system, o-anisidine, diphenylamine, guaicol, and o-toluidine, were not mutagenic.