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Vision-Based Jigsaw Puzzle Solving with a Robotic Arm. SENSORS (BASEL, SWITZERLAND) 2023; 23:6913. [PMID: 37571693 PMCID: PMC10422444 DOI: 10.3390/s23156913] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/15/2023] [Revised: 07/31/2023] [Accepted: 08/01/2023] [Indexed: 08/13/2023]
Abstract
This study proposed two algorithms for reconstructing jigsaw puzzles by using a color compatibility feature. Two realistic application cases were examined: one involved using the original image, while the other did not. We also calculated the transformation matrix to obtain the real positions of each puzzle piece and transmitted the positional information to the robotic arm, which then put each puzzle piece in its correct position. The algorithms were tested on 35-piece and 70-piece puzzles, achieving an average success rate of 87.1%. Compared with the human visual system, the proposed methods demonstrated enhanced accuracy when handling more complex textural images.
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Multiskin Color Segmentation Through Morphological Model Refinement. IEEE TRANSACTIONS ON EMERGING TOPICS IN COMPUTATIONAL INTELLIGENCE 2021. [DOI: 10.1109/tetci.2019.2892715] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Baseball Player Behavior Classification System Using Long Short-Term Memory with Multimodal Features. SENSORS 2019; 19:s19061425. [PMID: 30909503 PMCID: PMC6471259 DOI: 10.3390/s19061425] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/14/2019] [Revised: 03/12/2019] [Accepted: 03/20/2019] [Indexed: 11/16/2022]
Abstract
In this paper, a preliminary baseball player behavior classification system is proposed. By using multiple IoT sensors and cameras, the proposed method accurately recognizes many of baseball players' behaviors by analyzing signals from heterogeneous sensors. The contribution of this paper is threefold: (i) signals from a depth camera and from multiple inertial sensors are obtained and segmented, (ii) the time-variant skeleton vector projection from the depth camera and the statistical features extracted from the inertial sensors are used as features, and (iii) a deep learning-based scheme is proposed for training behavior classifiers. The experimental results demonstrate that the proposed deep learning behavior system achieves an accuracy of greater than 95% compared to the proposed dataset.
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Automatic Reference Color Selection for Adaptive Mathematical Morphology and Application in Image Segmentation. IEEE TRANSACTIONS ON IMAGE PROCESSING : A PUBLICATION OF THE IEEE SIGNAL PROCESSING SOCIETY 2016; 25:4665-4676. [PMID: 27390175 DOI: 10.1109/tip.2016.2586658] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
This paper proposes a novel automatic reference color selection (ARCS) scheme for the adaptive mathematical morphology (MM) method, and is specifically designed for color image segmentation applications. Because of the main advantages of being intuitive and simple, in the past decade, it has contributed to the growing popularity of binary and gray-scale MM processing. However, the MM process typically neglects the details of reference color determination. Applying other ordering methods, which select only black as the reference color for sorting pixels, result in the problem in which the scope of the distance measurement is not optimal. The proposed ARCS scheme is used for determining the ideal reference color for MM and for color image segmentation application. In addition, we use both 1D histogram-based modeling scheme binning from 3D color spaces, such as red-green-blue and hue-saturation-intensity, and 2D color models, such as (H, S), (Cb, Cr), and (I, By). According to the results of the quartile analysis, the threshold determination reacts with less sensitivity to the context variations of the images tested. The experiments focused on color-based image segmentation using the proposed ARCS scheme for color MM processing through a bottom-up scenario. To evaluate the system, four quantitative indices were utilized for an ARCS comparison using advanced segmentation methods in the experiments. The cross validation with different system parameters and a comparison of the morphological gradient operation with different color models are also presented.
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New quartile-based region merging algorithm for unsupervised image segmentation using color-alone feature. Inf Sci (N Y) 2016. [DOI: 10.1016/j.ins.2015.12.030] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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Time-weighted average sampling of airborne propylene glycol ethers by a solid-phase microextraction device. JOURNAL OF OCCUPATIONAL AND ENVIRONMENTAL HYGIENE 2012; 9:427-436. [PMID: 22651222 DOI: 10.1080/15459624.2012.685851] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
A solid-phase microextraction (SPME) device was used as a diffusive sampler for airborne propylene glycol ethers (PGEs), including propylene glycol monomethyl ether (PGME), propylene glycol monomethyl ether acetate (PGMEA), and dipropylene glycol monomethyl ether (DPGME). Carboxen-polydimethylsiloxane (CAR/PDMS) SPME fiber was selected for this study. A polytetrafluoroethylene (PTFE) tubing was used as the holder, and the SPME fiber assembly was inserted into the tubing as a diffusive sampler. The diffusion path length and area of the sampler were 0.3 cm and 0.00086 cm(2), respectively. The theoretical sampling constants at 30°C and 1 atm for PGME, PGMEA, and DPGME were 1.50 × 10(-2), 1.23 × 10(-2) and 1.14 × 10(-2) cm(3) min(-1), respectively. For evaluations, known concentrations of PGEs around the threshold limit values/time-weighted average with specific relative humidities (10% and 80%) were generated both by the air bag method and the dynamic generation system, while 15, 30, 60, 120, and 240 min were selected as the time periods for vapor exposures. Comparisons of the SPME diffusive sampling method to Occupational Safety and Health Administration (OSHA) organic Method 99 were performed side-by-side in an exposure chamber at 30°C for PGME. A gas chromatography/flame ionization detector (GC/FID) was used for sample analysis. The experimental sampling constants of the sampler at 30°C were (6.93 ± 0.12) × 10(-1), (4.72 ± 0.03) × 10(-1), and (3.29 ± 0.20) × 10(-1) cm(3) min(-1) for PGME, PGMEA, and DPGME, respectively. The adsorption of chemicals on the stainless steel needle of the SPME fiber was suspected to be one of the reasons why significant differences between theoretical and experimental sampling rates were observed. Correlations between the results for PGME from both SPME device and OSHA organic Method 99 were linear (r = 0.9984) and consistent (slope = 0.97 ± 0.03). Face velocity (0-0.18 m/s) also proved to have no effects on the sampler. However, the effects of temperature and humidity have been observed. Therefore, adjustments of experimental sampling constants at different environmental conditions will be necessary.
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An exploration of prevalence and associated factors of nonalcoholic Fatty liver disease in the taiwanese police service. IRANIAN JOURNAL OF PUBLIC HEALTH 2011; 40:54-62. [PMID: 23113103 PMCID: PMC3481735] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Subscribe] [Scholar Register] [Received: 02/18/2011] [Accepted: 11/17/2011] [Indexed: 10/24/2022]
Abstract
BACKGROUND The purpose of this study was to explore any gender-related differences in prevalence of and condition-associated factors related to non-alcoholic fatty liver disease (NAFLD) amongst police population in Taipei, Taiwan. METHODS We studied a total of 1016 healthy adults with police work (972 males and 44 females) voluntarily admitted to physical check-up between January 2006 and December 2006. Blood samples and ultrasound-proved fatty liver sonography results were collected. RESULTS The prevalence of NAFLD for this sub-population was found to be 52.2%, the prevalence revealing a statistically significant decrease with increasing population age (P<0.001). Males exhibited a greater prevalence of NAFLD than did females (53.6% vs 20.5%, P<0.0001). Using multiple logistic regression analysis, in addition to male gender, an older age, higher BMI, higher ALT, presence of hyperuricemia, hypercholesterolemia, and hypertriglyceridemia were the significant factors associated with NAFLD. Gender-related differences as regards associated factors were also revealed. For males, hyperuricemia (OR=1.35, 95%CI: 1.07-1.86), higher ALT (OR=2.31, 95%CI: 1.50-3.56), hypercholesterolemia (OR=1.33, 95%CI: 1.01-1.82), and hypertriglyceridemia (OR=1.55, 95%CI: 1.01-2.37) were significantly related to NAFLD but these were not so for females. CONCLUSION several gender-related differences were noted pertaining to the prevalence of and relationship between hyperuricemia, higher ALT, hypercholesterolemia, and hypertriglyceridemia and NAFLD in the present study.
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Wire-reinforced endotracheal tube penetrated by the Harmonic Scalpel. Anaesth Intensive Care 2010; 38:400-401. [PMID: 20369786] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
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Eliminate coherence spike in reflection-type pump-probe measurements. OPTICS EXPRESS 2009; 17:11321-11327. [PMID: 19582046 DOI: 10.1364/oe.17.011321] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
The coherence spike of femtosecond laser pulses in the reflection-type pump-probe measurements has been systematically studied in the semiconductor (100) InP. By varying the setup of the pump-probe measuring system, i.e. the polarizations of pump and probe pulses, the incident angles of pump and probe beams, and the interval of delay time between pump and probe pulses, the dramatic changes in the strength of coherence spike could be clear observed. Furthermore, the proposed methods to remove the coherence spike from the transient reflectivity curves have been demonstrated in the time-domain measurements.
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Strain-induced effects on antiferromagnetic ordering and magnetocapacitance in orthorhombic HoMnO(3) thin films. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2009; 21:026013. [PMID: 21814006 DOI: 10.1088/0953-8984/21/2/026013] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
We investigated the magnetic and ferroelectric properties of c-axis oriented orthorhombic phase HoMnO(3) (o-HMO in Pbnm symmetry setting) thin films grown on Nb-doped SrTiO(3)(001) substrates. The o-HMO films exhibit an antiferromagnetic ordering near 42 K, irrespective of the orientation of the applied field. However, an additional magnetic ordering occurring around 35 K was observed when the field was applied along the c-axis of o-HMO, which was absent when the field was applied in the ab-plane. The magnetocapacitance measured along the c-axis showed that although there is evidence of dielectric constant enhancement when the temperature is below 35 K the expected abrupt change in dielectric constant appears at a much lower temperature and reaches maximum around 13.5 K, indicating that the low-temperature c-axis polarization might be related to the ordering of the Ho(3+) moment. The lattice constant analyses using x-ray diffraction and the observation of a slight magnetization hysteresis suggest that the weak second magnetic transition along the c-axis at 35 K might be more relevant to the strain-induced effect on antiferromagnetism.
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Ordered YBCO sub-micron array structures induced by pulsed femtosecond laser irradiation. OPTICS EXPRESS 2008; 16:20610-20616. [PMID: 19065200 DOI: 10.1364/oe.16.020610] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
We report on the formation of organized sub-micron YBa(2)Cu(3)O(7) (YBCO) dots induced by irradiating femtosecond laser pulses on YBCO films prepared by pulse laser deposition with fluence in the range of 0.21 approximately 0.53 J/cm(2). The morphology of the YBCO film surface depends strongly on the laser fluences irradiated. At lower laser fluence (approximately 0.21 J/cm(2)) the morphology was pattern of periodic ripples with sub-micrometer spacing. Slightly increasing the laser fluence to 0.26 J/cm(2) changes the pattern into organized sub-micron dots with diameters ranging from 100 nm to 800 nm and height of 150 nm. Further increase of the laser fluence to over 0.32 J/cm(2), however, appeared to result in massive melting and led to irregular morphology. The mechanism and the implications of the current findings will be discussed. Arrays of YBCO sub-micron dots with T(c) = 89.7 K were obtained.
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The effect of an adenosine A1 receptor agonist in the treatment of experimental subarachnoid hemorrhage-induced cerebrovasospasm. Acta Neurochir (Wien) 2006; 148:873-9; discussion 879. [PMID: 16791438 DOI: 10.1007/s00701-006-0793-6] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2005] [Accepted: 04/18/2006] [Indexed: 01/09/2023]
Abstract
BACKGROUND Adenosine is a potent vasodilator and an important modulator of cardiovascular function. It has been postulated that nitric oxide (NO) is involved in adenosine-induced vasodilation. This study was designed to examine the effect of an adenosine A1 agonist, N6-cyclopentyladenosine (CPA), in the prevention of subarachnoid haemorrhage (SAH)-induced vasospasm. Method. Experimental SAH was induced in Sprague-Dawley rats by injecting 0.3 mL autogenous blood into the cisterna magna. Intraperitoneal injections of CPA (0.003 mg/kg), or vehicle were administered 5 min and 24 hours after induction of SAH. The degree of vasospasm was determined by averaging the cross sectional areas of the basilar artery 2 days after SAH. Expressions of endothelial nitric oxide synthase (eNOS) and inducible nitric oxide synthase (iNOS) in basilar artery were evaluated. Findings. There were no significant differences among the control and treated groups in physiological parameters recorded before sacrifice. When compared with animals in the control group, cross-sectional area of basilar arteries areas in the SAH only, SAH plus vehicle and SAH plus CPA groups were reduced by 19% (p < 0.01), 22% (p < 0.01), and 9% (p = 0.133), respectively. The cross-sectional areas of the CPA-treated group differed significantly from those of the SAH only and SAH plus vehicle group (p < 0.05). Induction of iNOS-mRNA and protein in basilar artery by SAH was not significantly diminished by CPA. The SAH-induced suppression of eNOS-mRNA and protein were relieved by CPA treatment. Conclusions. This is the first evidence to show an adenosine A1 receptor agonist is effective in partially preventing SAH-induced vasospasm without significant cardiovascular complications. The mechanisms of adenosine A1 receptor agonists in attenuating SAH-induced vasospasm may be, in part, related to preserve the normal eNOS expression after SAH. Inability in reversing the increased iNOS expression after SAH may lead to the incomplete anti-spastic effect of CPA.
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Abstract
The study sought to identify factors with consistent relationships with the prevalence of asthma and postulate causes for the increasing prevalence. Reduplication of prevalence surveys was conducted among children of similar ages (6-12 years) from the same area (Tainan City, Taiwan). A total of 7523 primary school children from 1993 and 7224 from 1997 participated in the study. The reported prevalence of diagnosed asthma increased from 6.46% in 1993 to 8.45% in 1997 (relative risk 1.31, 95% CI 1.16, 1.47). Among all environment- and heredity-related factors examined, only four showed consistent relationships with childhood asthma, and all appeared to be a related hereditary condition. Dander allergy is the only factor that increased correspondingly with the prevalence of childhood asthma; therefore, it seems to be the most likely key factor responsible for the increasing trend. The investigation of the interactive effects imposed by the environment- (dander exposure) and heredity-related (atopic sensitisation) factors are recommended for further studies.
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Combined use of esmolol and nicardipine to blunt the haemodynamic changes following laryngoscopy and tracheal intubation. Anaesthesia 2002; 57:1207-12. [PMID: 12479191 DOI: 10.1046/j.1365-2044.2002.02624_4.x] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
We examined the effect of different combinations of esmolol and nicardipine upon the circulatory response to tracheal intubation. One hundred patients were randomly allocated into five groups of twenty to receive pretreatments of saline or different combinations of esmolol (0.5 or 1.0 mg x kg(-1)) and nicardipine (15 or 30 microg x kg(-1)). Significant tachycardia persisted over a 5-min period after intubation in all five groups compared with baseline levels (p < 0.05). Patients receiving esmolol 1.0 mg x kg(-1) and nicardipine 30 g x kg(-1) showed no significant change in systolic blood pressure after tracheal intubation compared with baseline and significant lower peak systolic blood pressure than those receiving saline (p = 0.023).
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Prenatal exposure of testosterone prevents SDN-POA neurons of postnatal male rats from apoptosis through NMDA receptor. J Neurophysiol 2001; 86:2374-80. [PMID: 11698527 DOI: 10.1152/jn.2001.86.5.2374] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The role of N-methyl-D-aspartate (NMDA) receptor in mediating the effect of testosterone exposure prenatally on neuronal apoptosis in the sexual dimorphic nucleus of the preoptic area (SDN-POA) of rats was studied. The endogenous testosterone was diminished by prenatal stress (PNS) or simulated by testosterone exposure (TE) to understand the effect of testosterone on NR(1) (a functional subunit protein of NMDA receptor) expression and neuronal apoptosis. To further study whether the testosterone, after being converted into estradiol, modulates NR(1) expression, 4-androstein-4-ol-3,17-dione (ATD; an aromatase inhibitor) was used to block the conversion of estradiol from testosterone. The expressions of the NR(1) mRNA and NR(1) subunit protein were quantified by RT-PCR and western blotting analysis, respectively. In addition, a noncompetitive antagonist of NMDA receptor, MK-801, was used to find out whether blockage of NMDA receptor affects the naturally occurring apoptosis in SDN-POA. The results showed the following. 1) Expression of perinatal NR(1) subunit protein in the central part of the medial preoptic area of male rats was significantly higher than that of females, especially on postnatal days 1 and 3. 2) The testosterone level of male fetuses on embryonic day 18 was significantly higher than that of females, while the testosterone level of TE females or PNS males was similar to that of intact males or intact females, respectively. 3) The apoptotic incidence of intact male rats was significantly less than that of females, and the apoptosis was stimulated by PNS in male or inhibited by TE in female. 4) The expression of NR(1) subunit protein could be inhibited by PNS or ATD-treatment in male, while stimulated by TE in female. 5) NR(1) mRNA showed no significant difference among intact male, PNS male, ATD-treated male, TE female and intact female rats. 6) The low apoptotic incidence of male rats was significantly increased when NMDA receptor was blocked by MK-801. These results suggest that testosterone, after being converted to estradiol, may prevent the SDN-POA neurons of male rats from apoptosis through enhancing the expression of NR(1) at the posttranscriptional level.
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Positive association of ankylosing spondylitis with homozygous HLA-B2704, but protection with B2705 in Taiwan Chinese. Kaohsiung J Med Sci 2001; 17:509-16. [PMID: 11831114] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/23/2023] Open
Abstract
The study was undertaken to determine the effects of HLA-B27 subtypes on susceptibility to ankylosing spondylitis (AS) in Taiwan Chinese, a polymerase chain reaction-restrictive fragment length polymorphism (PCR-RFLP) method was developed for subtyping of HLA-B27. In this series, there are 62 patients with AS who were tested HLA-B27 positive serologically and 738 normal persons over the age of 65. Among the 738 normal controls, 42 (5.7%) were HLA-B27 positive. There were six (14.3%) homozygous for B2704, 18 (42.9%) heterozygous for B2704, 2 (4.8%) double heterozygous for B2704 and B2705, one (2.3%) double heterozygous for B2704 and B2706, 2 (4.8%) homozygous for B2705, 11 (26.1%) heterozygous for B2705, and 2 (4.8%) heterozygous for B2706. In our patients with AS, 37 (59.7%) were homozygous for B2704 and 25 (40.3%) were heterozygous for B2704. The HLA-B27 carrier rate in Taiwan healthy old persons is estimated at 5.7%. Susceptibility to AS is determined by homozygosity for B2704. However, B2705 may be an indicator of protection against AS in Taiwan Chinese.
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Hemodynamic Response of Modified Fluid Gelatin Compared with Lactated Ringer's Solution for Volume Expansion in Emergency Resuscitation of Hypovolemic Shock Patients: Preliminary Report of a Prospective, Randomized Trial. World J Surg 2001; 25:598-602. [PMID: 11369986 DOI: 10.1007/s002680020081] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
The objective of this study was to compare the cardiac and hemodynamic responses to a rapid infusion of 1000 ml of modified fluid gelatin (group A) or 1000 ml of lactated Ringer's solution (group B) in emergency room patients suffering from shock. This prospective, randomized, open, noncrossover study was performed at a medical center university hospital in a surgical resuscitation room in the emergency department. The subjects were 34 patients with either hypovolemic or neurogenic shock who were admitted to the emergency room. A resuscitation protocol according to Advanced Trauma Life Support (ATLS) with an additional central venous line or Swan-Ganz catheters for hemodynamic monitoring was used. Physical parameters and hemodynamic variables were measured at baseline and 15 minutes, 30 minutes, and 1 hour after the infusion of each fluid. In both groups the mean arterial blood pressure (MAP), systolic and diastolic pressure, central venous pressure (CVP), and pulmonary artery occlusion pressure (PAOP) increased significantly. The CVP and PAOP increased significantly more in the modified fluid gelatin resuscitation group. In patients with traumatic or neurogenic shock due to acute volume deficiency, there was significantly better hemodynamic improvement, judged by CVP and PAOP measurements using the modified fluid gelatin for volume replacement than with lactated Ringer's solution during the first hour of resuscitation.
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Abstract
We report cases of posterior cranial fossa arteriovenous fistula (AVF) with presenting with exophthalmos, chemosis and tinnitus in 26- and 66-year-old men. The final diagnoses was vertebral artery AVF and AVF of the marginal sinus, respectively. The dominant venous drainage was the cause of the unusual presentation: both drained from the jugular bulb or marginal sinus, via the inferior petrosal and cavernous sinuses and superior ophthalmic vein. We used endovascular techniques, with coils and liquid adhesives to occlude the fistulae, with resolution of the symptoms and signs.
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Comparison of the metabolic effects of metformin and troglitazone on fructose-induced insulin resistance in male Sprague-Dawley rats. J Formos Med Assoc 2001; 100:176-80. [PMID: 11393112] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/20/2023] Open
Abstract
BACKGROUND AND PURPOSE Insulin resistance is a hallmark of the development of type 2 diabetes. Metformin and troglitazone are oral antidiabetic agents used to reduce insulin resistance. The aim of this study was to compare the metabolic effects of these two drugs in fructose-induced insulin-resistant rodents. METHODS Male Sprague-Dawley rats were allocated to receive one of the following four treatments for 6 weeks: normal rat chow (control group, n = 7), high-fructose diet (fructose group, n = 7), high-fructose diet plus metformin (metformin group, n = 8), or high-fructose diet plus troglitazone (troglitazone group, n = 8). Systolic blood pressure (SBP), insulin, free fatty acid (FFA), and triglyceride concentrations were measured as parameters of insulin resistance. Leptin concentration was also measured in the four groups. RESULTS The fructose group developed significantly elevated SBP, hyperinsulinemia, and hypertriglyceridemia without significant change in body weight or leptin concentration compared with the control group. The metformin group had significantly reduced body weight (397.9 +/- 40.9 vs 470.1 +/- 59.6 g, p < 0.05), insulin concentration (14.8 +/- 10.5 vs 48.4 +/- 15.2 microU/mL, p < 0.05), triglyceride concentration (75.3 +/- 65.5 vs 250.1 +/- 95.7 mg/dL, p < 0.05), and leptin concentration (3.1 +/- 1.5 vs 6.9 +/- 2.0 ng/mL, p < 0.05) without significant change in SBP (147.8 +/- 5.8 vs 152.4 +/- 13.0 mm Hg, p > 0.05) compared with the fructose group. The troglitazone group had significantly reduced SBP (137.8 +/- 9.2 vs 152.4 +/- 13.0 mm Hg, p < 0.05), insulin concentration (15.0 +/- 13.6 vs 48.4 +/- 15.2 microU/mL, p < 0.05), FFA concentration (38.9 +/- 22.7 vs 78.7 +/- 24.6 mg/dL, p < 0.05), triglyceride concentration (67.6 +/- 32.4 vs 250.1 +/- 95.7 mg/dL, p < 0.05), and leptin concentration (4.4 +/- 2.0 vs 6.9 +/- 2.0 ng/mL, p < 0.05) without significant change in body weight (452.5 +/- 32.8 vs 470.1 +/- 59.6 g, p > 0.05) compared with the fructose group. The metabolic effects of metformin and troglitazone on insulin, FFA, triglyceride, and leptin concentrations were not significantly different. However, metformin treatment resulted in significantly lower body weight (397.9 +/- 40.9 vs 452.5 +/- 32.8 g) and troglitazone treatment in significantly lower SBP (137.8 +/- 9.2 vs 147.8 +/- 5.8 mm Hg) compared to the fructose group, after adjusting for basal values (p < 0.05). CONCLUSIONS Both metformin and troglitazone were comparably effective in reducing insulin resistance. Metformin treatment caused body weight reduction but was not effective in reducing SBP. Troglitazone treatment lowered SBP but did not reduce body weight.
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Warning from Nagano: increase of vulvar hematoma and/or lacerated injury caused by snowboarding. THE JOURNAL OF TRAUMA 2001; 50:328-31. [PMID: 11242300 DOI: 10.1097/00005373-200102000-00021] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
BACKGROUND On the basis of the number of women snowboarders whose vulvar injuries we have recently treated, we believe that the cases of vulvar hematoma and lacerated injuries caused by snowboarding have been increasing. To analyze the causal relation between snowboarding and vulvar injuries, we investigated how women were injured during snowboarding. METHODS During the last three ski-ing seasons at the five hospitals near the ski resorts in Nagano Prefecture, Japan, the clinical charts of all patients with vulvar injuries during snowboarding were reviewed for the number of patients treated, the condition of the patients at diagnosis, and the characteristics of vulvar injuries. All patients were also asked by phone about how their vulvar injury was caused during snowboarding. RESULTS The number of patients with vulvar injuries during the last three seasons was 16, 14, and 35, respectively. The types of vulvar injuries included hematoma in 33 (51%) patients, hematoma with lacerated injury in 17 (26%), and lacerated injury in the remaining 15 (23%). Of the 65 patients, 45 (69%) needed surgical treatment. Characteristically, 54 (88%) patients were injured when they tumbled onto the binding of the snowboard at the same time that one foot was left off the board and the binding was not turned down but left erect. CONCLUSION It is important for women snowboarders to realize that in snowboarding there are dangers that may cause vulvar injuries. The prevention of such injuries requires that the binding should be turned down when the foot is left off the board and that snowboarders should try not to tumble onto the board.
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Anti-aging effects of the traditional Chinese medicine bu-zhong-yi-qi-tang in mice. THE AMERICAN JOURNAL OF CHINESE MEDICINE 2000; 28:77-86. [PMID: 10794119 DOI: 10.1142/s0192415x00000106] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Among the "alternative medicines," which may ably supplement modern Western medicine in the treatment of certain diseases, the holistic approach and mild nature of the majority of Traditional Chinese Medicine (TCM) may make it particularly suitable for the treatment of diseases associated with old age, as the general health of elderly patients is already compromised. The TCM formulation of bu-zhong-yi-qi-tang (B.Z.Y.Q.T.), prescribed mainly for the improvement of circulation and in particular that to the gastroenteric regions, may have anti-aging effects. In the present study, possible anti-aging effects of B.Z.Y.Q.T. were studied using normal (ICR) mice and the Dull, P/8 and R/1 strains of the Senescence Accelerated Mouse (S.A.M.). Following repeated oral administrations of B.Z.Y.Q.T. at 250 and 500 mg/kg the test mice were assessed for (1) endurance (2) learning and memory (3) neuromuscular coordination and (4) changes in the levels of monoamines in the brain. The results indicated that B.Z.Y.Q.T. improved endurance in all strains in a dose-dependent manner. At the higher dose of 500 mg/kg, it improved memory in the R/1 and P/8 S.A.M. mice. In prolonged rota-rod tests, which assessed both motor coordination and endurance, B.Z.Y.Q.T. significantly improved performance in the P/8 S.A.M. mice. Elevated dopamine and noradrenaline were observed in cortical tissues of the S.A.M./Dull and ICR mice respectively with the high dose of 500 mg/Kg, B.Z.Y.Q.T. Taken together, the results indicated that B.Z.Y.Q.T. appeared to exert anti-aging effects in mice and elevation in certain monoamines in brain cortical tissues. How and whether the monoamines changes after B.Z.Y.Q.T. treatment might be related to the behavioral effects await further investigation.
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Selective association between a macrocyclic nickel complex and extrahelical guanine residues. Biochemistry 1999; 38:15034-42. [PMID: 10555986 DOI: 10.1021/bi991877h] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Nickel-dependent recognition and oxidation of guanine have been linked in part through the paramagnetic effects of nickel on the NMR of model oligonucleotide duplexes. Direct interaction between nickel and guanine N7 had originally been postulated from correlations between the efficiency of guanine oxidation and the environment surrounding its N7 position. (1)H and (31)P NMR spectra of DNA containing a single, isolated extrahelical guanine are consistent with selective binding of nickel to the N7 of this unique base over a background of nonspecific association to the phosphate backbone. The presence of a macrocyclic complex or simple salt of nickel did not detectably alter the structure of the duplex or extrahelical residue. Accordingly, nickel appeared to bind the extrahelical guanine N7 within the major groove as indicated by paramagnetic effects on the proton signals of nucleotides on the 5' but not 3' side of the nickel binding site. Similar (1)H NMR analysis of DNA containing a dynamic equilibrium of extrahelical guanine residues also suggested that the nickel complex did not affect the native distribution of structures. Oxidation of these sites by a nickel-mediated pathway consequently reflected their solvent accessibility in a general and metal-independent manner. The close proximity of the extrahelical guanines produced a composite of paramagnetic effects on each adjacent nucleotide resulting from both direct and proximal coordination of nickel.
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The advisability of implementing cholesterol screening in school-age children and adolescents with a family history of cardiovascular disease and hyperlipidaemia. Fam Pract 1999; 16:501-5. [PMID: 10533947 DOI: 10.1093/fampra/16.5.501] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
BACKGROUND The family basis of coronary heart disease is well recognized and it is important for family physicians to assess whether children have elevated cholesterol levels. OBJECTIVES We aimed to evaluate the advisability of implementing cholesterol screening in children with a family history of cardiovascular disease and hyperlipidaemia. METHODS We conducted a cross-sectional study in Taiwan from February to June 1996. There were 47,800 students in the population. A total of 4520 students were recruited by two-stage sampling. All the participants were required to fill out a structured questionnaire. RESULTS The response rate was 92.5%. Our results show that 16-18% of the children had a positive family history of cardiovascular disease or hyperlipidaemia. Children with a family history of hyperlipidaemia were significantly more likely to have elevated total cholesterol and low-density lipoprotein cholesterol than those without such a history (both odds ratios: 1.4, P < 0.05). Positive predictive values of hyperlipidaemia were less than 13% based on family history. More than 75% of children with abnormal lipid levels would be missed. CONCLUSIONS The data suggest that parents' self-reported family history is an ineffective means of identifying children with elevated serum lipid levels in Taiwan. Further research and modification of current National Cholesterol Education Program Panel guidelines for selective cholesterol screening in children may be warranted.
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Safety of distilled water as an irrigating fluid for transurethral resection of the prostate. ZHONGHUA YI XUE ZA ZHI = CHINESE MEDICAL JOURNAL; FREE CHINA ED 1999; 62:503-8. [PMID: 10462826] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/13/2023]
Abstract
BACKGROUND Irrigating fluid is necessary for transurethral resection of the prostate (TURP). Initially, distilled water was used as irrigating fluid and some advantages and complications were noted. Although other solutions were used to substitute for distilled water, we collected data for changes in electrolytes and hematocrit (Hct) during surgery to evaluate the safety of distilled water as irrigating fluid for TURP with suprapubic trocar cystostomy. METHODS Fifty-three patients who underwent TURP using distilled water as irrigating fluid were investigated. TURP was performed with suprapubic trocar cystostomy routinely. Preoperative and postoperative blood samples were collected and analyzed for electrolytes and Hct to study any changes during surgery. RESULTS The change in plasma sodium concentration was not statistically significant, but the decreases in blood Hct and plasma potassium concentration were statistically significant. There was no major operative complication and no clinical-evident related postoperative renal impairment. CONCLUSIONS Distilled water is a relatively safe solution as an irrigating fluid for TURP under drainage with suprapubic trocar cystostomy, but attention must be paid to the inevitable blood loss during surgery.
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Noninvasive evaluation of blunt abdominal trauma: prospective study using diagnostic algorithms to minimize nontherapeutic laparotomy. World J Surg 1999; 23:265-69; discussion 269-70. [PMID: 9933698 DOI: 10.1007/pl00013178] [Citation(s) in RCA: 46] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
A prospective study was performed to investigate the feasibility and benefit of evaluating blunt abdominal trauma (BAT) without diagnostic peritoneal lavage (DPL) or other invasive methods. Diagnostic algorithms were designed by using ultrasonography (US) as a screening method. For unstable patients, a free fluid >/= 2 mm thickness on US images over any one of the intraperitoneal spaces (bilateral subphrenic, Morrison, and Douglas pouch) was used as an indicator for laparotomy. For stable patients, any intraabdominal free fluid detected by US was used as an indicator for further investigations. Computed tomography served as a principal complementary method. To further clarify the clinical results, the rate of nontherapeutic laparotomy (NTL) was compared with that from a previous 5-year review done before this study. During studying period of 1 year, 170 patients were consecutively enrolled. There was no delayed diagnosis, and 66 patients were found to have BAT; 17 patients were initial unstable, among whom 15 had free fluid shown by US and 13 patients had confirmed BAT. Eight of the unstable patients with free fluid on US were saved from NTL, of whom six had retroperitoneal hematoma. There was no NTL in unstable patients. Twenty-two patients underwent laparotomy. Two laparotomies done for a suspicion of bowel injury turned out to be NTL. The rate of NTL in the present study was significant lower than that in a previous review (9.1% vs. 32.2%, p = 0.025). Hence following well designed algorithms, noninvasive evaluation of BAT can proceed with safety, and NTL is minimized.
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Superoxide production of neutrophils after severe injury: impact of subsequent surgery and sepsis. Am J Emerg Med 1999; 17:15-8. [PMID: 9928689 DOI: 10.1016/s0735-6757(99)90005-0] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
To evaluate the early variations of superoxide production of neutrophils (SPN) in injured patients, SPN was serially measured on the first, third, and seventh day after severe injury (injury severity score of >16). For patients receiving subsequent surgery, SPN was measured again on the first postoperative day. Eighteen patients were studied. Six had subsequent surgery within 1 day (early operation); 6 had surgery 3 days after injury (late operation); 6 did not have surgery (nonoperation). SPN increased on the first day and recovered from the third day after injury in all three groups. In patients who had surgery, SPN did not significantly increase on the first postoperative day. Eight patients developed sepsis, 4 of whom had early multiple organ dysfunction (EMOD). On the last measurement, mean SPN was suppressed in septic patients with EMOD, whereas it was elevated in septic patients without EMOD. Patients with EMOD also had a higher injury severity score. In conclusion, subsequent surgery after injury has no effect on the priming of neutrophils. While late priming of neutrophils in injured patients coincides with the development of sepsis, suppression of SPN is found in septic patients with EMOD that frequently results from severe injury.
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Abstract
Construction workers are known to have occupational dermatoses. The prevalence of such dermatoses was unknown in Taiwanese construction workers. The objective of this study was to determine the work exposure, prevalence of skin manifestations, and sensitivity to common contact allergens in cement workers of southern Taiwan. A total of 1147 current regular cement workers were telephone-interviewed about skin problems during the past 12 months, work exposure, and personal protection. Among those interviewed, 166 were examined and patch tested with common contact allergens. A high % of cement workers reported skin problems in the past 12 months. More men (13.9%) reported skin problems possibly related to work than women (5.4%). Prevalence was associated with lower use of gloves, duration of work as cement worker, and more time in jobs involving direct manual handling of cement, especially tiling. A high % of dermatitis was noted in the 166 workers examined, which correlated with reported skin problems. On patch testing, construction workers had a high frequency of sensitivity to chromate. Sensitivity to chromate or cobalt was associated with reported skin problems, or dorsal hand dermatitis on examination. These workers' dermatitis was under-diagnosed and inadequately managed. It is concluded that cement workers in southern Taiwan had a high prevalence of skin problems related to cement use. Protective measures, work practice, and physician education should be improved to prevent or manage such problems.
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Plasma alkaline phosphatase activity in children and adolescents. ZHONGHUA MINGUO XIAO ER KE YI XUE HUI ZA ZHI [JOURNAL]. ZHONGHUA MINGUO XIAO ER KE YI XUE HUI 1998; 39:386-8. [PMID: 9926512] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 04/11/2023]
Abstract
From February to June in 1996, there were 47,800 students for health examination in Taichung City, Taiwan. The population consisted of the first and fourth graders of primary schools and the first grader of junior high schools. We selected 3,452 healthy students for further study by two stage sampling. In this report, 52.5% of the students were boys, and 47.5% of the students were girls. The mean age of students was 9.9 +/- 2.4 years. Girls at age 7 and age 10 had higher activity of alkaline phosphatase than boys at the same age. The peak of alkaline phosphatase activity in girls occurred at age 10. Alkaline phosphatase activity was significantly related to weight-length index by multiple regression analysis (p < 0.05). Although clinical application as an obesity factor still needs further investigation, in the future it may be well to routinely check this enzyme when assessing childhood obesity.
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Modulation of ceramide-activated protein phosphatase 2A activity by low molecular weight aromatic compounds. Biochem Pharmacol 1998; 55:1105-11. [PMID: 9605434 DOI: 10.1016/s0006-2952(97)00685-0] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Protein phosphatase 2A (PP2A) is one of the most important and abundant serine/threonine phosphatases in mammalian tissues and plays a role in gene expression, cell division, and signal transduction. PP2A is activated by ceramide, which is produced by the hydrolysis of membrane sphingomyelin in response to a variety of stress-related stimuli. To further study the role of ceramide-mediated signal transduction in cellular processes such as senescence and apoptosis, we designed and synthesized a series of low molecular weight aromatic compounds, mainly of the isoquinolone and tetralone classes, and evaluated their ability to inhibit enzymes known to be activated by ceramide. Those enzymes studied were ceramide-activated protein kinase, protein kinase C zeta and PP2A. Of these, only PP2A was found to be inhibited. A few of the compounds inhibited both ceramide-activated as well as basal PP2A activity. In addition, several of the compounds activated PP2A by up to 300% above basal enzyme activity, but only in the presence of ceramide. Thus, modulation (both inhibition and activation) of the catatylic activity of ceramide-activated PP2A is demonstrated by certain low molecular weight aromatic compounds.
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Effects of ovarian steroid hormones and thyroxine on calcitonin secretion in pregnant rats. THE AMERICAN JOURNAL OF PHYSIOLOGY 1998; 274:E246-52. [PMID: 9486154 DOI: 10.1152/ajpendo.1998.274.2.e246] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
In the present study, the roles of ovarian steroid hormones and thyroxine (T4) in regulating the secretion of calcitonin (CT) in pregnant rats were examined. The levels of plasma progesterone, pre- and post-CaCl2 plasma CT, and recovery time of plasma CT and calcium after calcium challenge were greatest in midterm pregnant rats. The levels of basal plasma progesterone, CT, calcium, and recovery time of plasma CT after calcium challenge were less in late pregnant rats, but basal plasma estradiol was highest in late pregnancy. The concentrations of plasma T4 were gradually decreased in rats during pregnancy. Regardless of the presence of estradiol, administration of progesterone in ovariectomized (Ovx) rats resulted in an increase of plasma T4 as well as the basal and calcium-induced secretion of CT. Administration of estradiol alone did not alter the CaCl2-induced levels but decreased the post-CaCl2 levels of plasma calcium in Ovx rats. The basal levels of plasma CT were decreased in Ovx rats treated with T4. These results suggest that the hypercalcitoninemia in midterm pregnant rats is due to an increased secretion of progesterone. Hypocalcitoninemia in late pregnant rats, however, is due in part to lower plasma calcium.
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Alternations of surface antigens on leukocytes after severe injury: correlation with infectious complications. Intensive Care Med 1998; 24:152-6. [PMID: 9539073 DOI: 10.1007/s001340050537] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
OBJECTIVE To investigate the alternations of surface antigens of leukocytes after severe injury and the correlation with clinical outcome. SETTING Emergency Department and Intensive Care Unit of a university hospital. PATIENTS Patients with severe trauma (injury severity score > 16) were enrolled. Those who were transferred or had critical injuries were excluded. MEASUREMENTS AND RESULTS Polymorphonuclear cells (PMN) and mononuclear cells (MN) were isolated from patients on the 1st, 3rd and 7th day following injury. The mean fluorescent expressions of CD11b and CD16 of PMN, and CD25 of MN were measured and compared with those obtained from paralleled controls. Sixteen injured patients were included. The CD11b expressions of PMN increased on the 1st day and were still high on the 7th day. The CD16 expressions decreased on the 1st day and CD25 decreased on the 3rd day; both were still low on the 7th day. Six patients developed infectious complications. CD11b expression remained high and CD16 expression remained low on three measurements of the infectious patients, whereas both expressions recovered on the last measurement of non-infectious patients. CD25 expression remained low in both groups. Three infectious patients with pneumonia died from multiple organ failure. CONCLUSIONS Phenotypic alternations of leukocytes develop early after severe injury. The alternations may represent a state of activation of PMN and subsequent suppression of IL-2 related immunity. Persistent activation of PMN with enhanced CD11b and attenuated CD16 expression indicates the development of infectious complications and a poor prognosis can be anticipated if the infectious sites can not be controlled early.
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Inhibition of bufalin on pituitary and testicular function in rats. J Pharmacol Exp Ther 1997; 283:528-32. [PMID: 9353366] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
The effects of bufalin on the secretion of testosterone and luteinizing hormone (LH) and the accumulation of testicular adenosine 3':5'-cyclic monophosphate (cAMP) were studied. Male rats were injected with bufalin, human chorionic gonadotropin (hCG), gonadotropin releasing hormone (GnRH), hCG plus bufalin or GnRH plus bufalin via a jugular catheter. Blood samples were collected at several intervals subsequent to the challenge. In the in vitro study, rat testis blocks were incubated with bufalin, hCG or both for 1 h. The anterior pituitary gland was incubated with bufalin, GnRH or both for 30 min. The media were analyzed for testosterone or LH. For studying cAMP accumulation, testicular blocks were incubated for 1 h with the medium containing isobutyl-1-methylxanthine. After incubation, tissues were extracted by ethanol before measuring cAMP concentration. A single intravenous injection of bufalin decreased the basal and hCG-stimulated levels of plasma testosterone. Administration of bufalin in vitro resulted in an inhibition of both basal and hCG-stimulated release of testosterone. Bufalin diminished cAMP accumulation in rat testes. However, the basal levels of plasma and medium LH were not altered by bufalin administration. Likewise, the LH response to GnRH was diminished by bufalin administration, both in vivo and in vitro. These results suggest that the inhibition of testosterone production by bufalin is partly caused by a decrease of testicular cAMP accumulation and LH response to GnRH in rats.
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Unilateral pulmonary edema during general anesthesia--report of two cases. ACTA ANAESTHESIOLOGICA SINICA 1997; 35:175-80. [PMID: 9407683] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Unilateral presentation of pulmonary edema, though well known to occur, is an uncommon entity. Previous reviews of this subject have discussed the different etiologies, which include rapid reexpansion of collapsed lung, down lung syndrome (gravitational edema), systemic-to-pulmonary arterial shunts, heart failure, compression or occlusion of pulmonary vasculatures, obstruction of a bronchus and an acute manifestation of neuropulmonary reaction (neurogenic pulmonary edema). Occurrence of this complication during surgery, however, is even rarer. We report 2 cases of unilateral pulmonary edema occurring during general anesthesia for elective surgery.
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Lactate and the effects of exercise on testosterone secretion: evidence for the involvement of a cAMP-mediated mechanism. Med Sci Sports Exerc 1997; 29:1048-54. [PMID: 9268962 DOI: 10.1097/00005768-199708000-00010] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
The effects of swimming and lactate on the release of testosterone were examined in male rats. During in vivo experiments, male rats were catheterized via the right jugular vein and blood was collected at 0, 10, 15, 30, and 60 min following the exercise, or they were catheterized via the right jugular vein and the left femoral vein and blood was collected at 0, 2, 5, 10, 15, 30, 60, and 120 min after a 10-min infusion at lactate (13 mg.kg-1.min-1). Trunk blood and blood from the testicular vein were also collected after 10 min of swimming or water immersion. In an in vitro experiment, testicular fragments were challenged with lactate (0.01-10 mM) and/or human chorionic gonadotropin (hCG; 0.5 IU.mL-1), and the mediobasal hypothalamus (MBH) was challenged with lactate (8 mM). The post-exercise levels of plasma lactate and testosterone at 10, 15, and 30 min were higher than resting levels. Plasma luteinizing hormone (LH) was increased following 30 min of swimming. Administration of lactate or hCG increased in a dose dependent manner testicular cyclic adenosine 3':5' monophosphate (cAMP) and testosterone release. Plasma testosterone increased after swimming and lactate infusion. Incubation of MBH with lactate increased the gonadotropin-releasing hormone (GnRH) level in the medium. These results suggest that the increased plasma testosterone levels in male rats during exercise is at least partially a result of a direct and LH-independent stimulatory effect of lactate on the secretion of testosterone by increasing testicular cAMP production. Swim-elevated plasma LH may be a result of a rise of GnRH caused by lactate.
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Response of resuscitation in multiple trauma with pelvic fracture. ZHONGHUA YI XUE ZA ZHI = CHINESE MEDICAL JOURNAL; FREE CHINA ED 1997; 60:98-104. [PMID: 9360335] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
BACKGROUND The early management of patients with pelvic injury remains a great challenge for emergency physicians and trauma surgeons. A retrospective study was performed in this hospital to identify the clinical significance of different responses in the resuscitation of pelvic injury. METHODS From March 1989 to May 1995, 75 patients with pelvic ring injury who had initially had unstable hemodynamic status were studied. They were divided into four groups as "good response" (GR), "delayed response" (DR), "poor response" (PR) and "no response" (NR) according to the time when hemodynamics became stable after immediate resuscitation. RESULTS Motor vehicle accidents (MVA) had a higher incidence than other causes in the trauma mechanism. The fracture types of pelvis had no correlation with the response to resuscitation. The injury severity score (ISS) was higher in the PR group (41.7 +/- 18.3) than in the GR (17.5 +/- 8.6) or DR (19.5 +/- 17.0). The incidence of extrapelvic hemorrhage (EPH) and of mortality rates was higher in the PR group (38% and 75%, respectively), and the DR group (25% and 13%, respectively), than in the GR group (6% and 2%, respectively). CONCLUSIONS The responses of resuscitation is a valuable parameter in the management of multiple trauma with pelvic injury. Nonoperative treatment may be tried in patients of good response to resuscitation with EPH. In those patients with poor or delayed response, delayed extrapelvic bleeding (especially from abdominal injury) must be ruled out besides aggressive management for pelvic injury. Poor prognosis can also be expected in those patients with poor response.
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Gastric emptying and gastrointestinal transit during lactation in rats. THE AMERICAN JOURNAL OF PHYSIOLOGY 1997; 272:G626-31. [PMID: 9124584 DOI: 10.1152/ajpgi.1997.272.3.g626] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Female sex hormones can influence gastrointestinal function. To understand whether postpartum changes in female sex hormones may affect such function, gastric emptying and gastrointestinal transit were measured in rats on days 1-2, 10, 15, and 21 of lactation, on day 7 postweaning, and at the nonpregnant diestrous stage. Gastric emptying and gastrointestinal transit were assessed in conscious rats 15 min after intragastric instillation of a test meal containing charcoal and (51)Cr. The results showed that gastric emptying was increased throughout the first 2 wk of lactation, with a gradual decrease as lactation proceeded toward weaning, and returned to the level of the virgin rats by 1 wk postweaning. Gastrointestinal transit was greater in the early stage of lactation and was related to gastric emptying (P < 0.001). Increases in gastric emptying and intestinal length were correlated with lactation (P < 0.001) and plasma prolactin levels (P < 0.05) but not with plasma progesterone or estradiol levels. We concluded that the sex steroid hormones associated with lactation do not mediate a change in gastric emptying and gastrointestinal transit during lactation.
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Abstract
The secretion of erythropoietin (EPO) and testosterone in response to hypoxia in old (22-25 months), middle (mid)-aged (15-17 months), adult (6-7 months), and young (3 months) male rats was studied. Rats of different ages were bled by cardiac puncture before and subsequent to 8 h exposure to 12% O2. The metabolic clearance rate of EPO was determined by a single-injection method. The effects of orchidectomy and replacement of testosterone propionate on plasma EPO concentrations were also investigated. Analysis of the direct effects of testosterone on EPO release from kidney tissue was carried out in an in vitro study. Both basal and hypoxia-induced EPO levels were lower in old rats than in mid-aged, adult, and young rats (p < .01). Plasma testosterone levels decreased in response to hypoxia in all rats (p < .01 for young, adult, and mid-aged rats, and p < .05 for old rats). The old rats also had lower plasma testosterone levels following hypoxia when compared with other rats (p < .05). The metabolic clearance rate of EPO was not affected by age. Orchidectomy decreased rat plasma EPO concentration (p < .05). This decrease could be restored to intact levels after testosterone propionate replacement. Both 10(-10) M (p < .05) and 10(-9) M (p < .01) testosterone stimulate EPO release from kidney tissue in vitro. Our findings indicate that the basal levels of plasma EPO and testosterone are decreased, and the hypoxia-induced EPO is also diminished with aging in male rats. These data suggest that the mechanism of tolerance to hypoxia and the endocrine function of the kidneys in male rats during the aging process are testosterone-dependent.
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Lactate stimulates progesterone secretion via an increase in cAMP production in exercised female rats. THE AMERICAN JOURNAL OF PHYSIOLOGY 1996; 271:E910-5. [PMID: 8944680 DOI: 10.1152/ajpendo.1996.271.5.e910] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
The effect of exercise on the production of ovarian progesterone was examined in female rats. During in vivo experiments, diestrous rats were catheterized via the right jugular vein (RJV), and blood samples were collected before and after 10, 15, 30, and 60 min of swimming. In addition, blood samples were collected from the RJV before and 2, 5, 10, 15, 30, 60, and 120 min after 10 min of infusion of lactate (13 mg.kg-1.min-1) through the left femoral vein. To explore if lactate modulates progesterone secretion by acting directly on rat ovary or on anterior pituitary gland (AP), an in vitro experiment that mimicked the in vivo condition was performed. The ovarian tissue was challenged with lactate (0.01-10 mM) or porcine follicle-stimulating hormone (1 microgram/ml) and 3-isobutyl-1-methylxanthine (1 mM) for 60 min, and the AP was challenged with lactate ranging from 0.1 to 10 mM or 10 nM gonadotropin-releasing hormone for 30 min. The postexercise levels of plasma glucose, lactate, and progesterone at 10, 15, and 30 min were significantly higher than the corresponding basal levels. Plasma luteinizing hormone (LH) did not change after exercise. An elevation of plasma lactate and progesterone was found at 15 and 30 min subsequent to 10 min of infusion of lactate. Lactate ranging from 0.01 to 10 mM significantly increased ovarian adenosine 3',5'-cyclic monophosphate (cAMP) and progesterone production in a dose-dependent manner. LH concentration in plasma was not changed subsequent to lactate infusion. LH level in media samples was not altered after incubation of AP with lactate. These results suggest that the increase of plasma progesterone level in rats during exercise is independent of LH secretion and at least in part is due directly to a stimulatory effect of lactate on the production of ovarian cAMP.
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Inhibition by amphetamine of testosterone secretion through a mechanism involving an increase of cyclic AMP production in rat testes. Br J Pharmacol 1996; 118:984-8. [PMID: 8799572 PMCID: PMC1909523 DOI: 10.1111/j.1476-5381.1996.tb15496.x] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
1. The effect of amphetamine on the secretion of testosterone and the production of testicular adenosine 3':5'-cyclic monophosphate (cyclic AMP) in rats was studied. 2. A single intravenous injection of amphetamine decreased the basal and human chorionic gonadotropin (hCG)-stimulated levels of plasma testosterone. Plasma LH levels were not altered by the injection of amphetamine. 3. Administration of amphetamine in vitro resulted in a dose-dependent inhibition of both basal and hCG-stimulated release of testosterone. 4. Amphetamine enhanced the basal and hCG-increased levels of cyclic AMP accumulation in vitro in rat testes. 5. These results suggest that amphetamine inhibits the spontaneous and hCG-stimulated secretion of testosterone from the testes through a mechanism involving an increase in cyclic AMP production.
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Progesterone stimulates in vitro release of prolactin and thyrotropin involving cAMP production in rat pituitary. CHINESE J PHYSIOL 1996; 39:245-51. [PMID: 9058009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
Effects of progesterone administration in vivo or in vitro on the release of pituitary prolactin (PRL) and thyroid stimulating hormone (TSH) in vitro, as well as the generation of pituitary cyclic adenosine 3', 5'-monophosphate (cAMP) were studied in ovariectomized (Ovx) rats. Ovx rats were either decapitated or injected subcutaneously with progesterone, or oil for 3 days before decapitation. The anterior pituitary glands (APs) of progesterone treated Ovx rats were incubated with Locke's medium containing thyrotropin-releasing hormone (TRH, 10 nM) and/or 3-isobutyl-1-methylxanthine (IBMX, 1 mM) at 37 degrees C for 30 min. The APs of untreated Ovx rats were incubated in vitro with IBMX and progesterone (0, 0.1, 1, 10 nM). Progesterone increased spontaneous and TRH-induced release of PRL and TSH in vitro. Administration of progesterone, either in vivo or in vitro, increased the production of pituitary cAMP following incubation of IBMX. These results suggest that progesterone increases the release of PRL and TSH through a mechanism associated with an increase of cAMP production in rat APs.
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Role of chloride groups in the nephrotoxic potential of N-(3,5-dichlorophenyl)-2-hydroxysuccinimide, an oxidative metabolite of N-(3,5-dichlorophenyl)succinimide. Toxicol Lett 1995; 78:49-56. [PMID: 7604399 DOI: 10.1016/0378-4274(94)03232-v] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Although the addition of chloride groups to the phenyl ring of N-phenylsuccinimide (NPS) is known to enhance the nephrotoxic potential of NPS, the mechanism of this enhancement is unknown. One chlorinated NPS derivative, N-(3,5-dichlorophenyl)succinimide (NDPS), is a potent nephrotoxicant which induces marked proximal tubular necrosis at i.p. doses of 0.4 mmol/kg or greater. The purpose of this study was to compare the nephrotoxic potential of 2-hydroxy-N-phenylsuccinimide (HNPS) and N-(3,5-dichlorophenyl)-2-hydroxysuccinimide (NDHS), an oxidative and nephrotoxicant metabolite of NDPS, to determine the importance of the chloride groups for the nephrotoxic potential of NDHS. Male Fischer 344 rats (4/group) were administered a single i.p. injection of HNPS (1.0 or 1.5 mmol/kg), NDHS (0.1 mmol/kg) or vehicle (25% dimethyl sulfoxide in sesame oil), and renal function measured at 24 and 48 h. HNPS was a nonnephrotoxicant at both doses tested, while NDHS induced marked nephrotoxicity characterized by diuresis, increased proteinuria, glucosuria, elevated blood urea nitrogen (BUN) concentration and kidney weight, decreased organic ion accumulation by renal cortical slices and proximal tubular necrosis. In vitro, HNPS reduced p-aminohippurate (PAH) and tetraethylammonium (TEA) accumulation beginning at HNPS bath concentrations of 0.05 and 0.5 mM, respectively. The results of this study indicate that although HNPS has direct effects on renal function in vitro, HNPS is not a nephrotoxicant in vivo at doses up to 15 times the minimal nephrotoxicant dose of NDHS. Therefore, the chloro groups present on NDHS play an essential role in the nephrotoxic potential of NDHS and contribute to aspects of the nephrotoxic mechanism of NDPS beyond NDPS oxidation to form NDHS.
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Urgent laparotomy versus emergency craniotomy for multiple trauma with head injury patients. THE JOURNAL OF TRAUMA 1995; 38:154-7. [PMID: 7745648 DOI: 10.1097/00005373-199501000-00035] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
In blunt multiple trauma (MT) with head injury (HI) patients, it is difficult to decide whether to proceed with immediate laparotomy or craniotomy. In August 1989, abdominal ultrasonography (US) using a simple US scoring system was introduced for MT and HI patients as an initial rapid screening procedure. In MT and HI patients with a US score > or = 3 (n = 14), urgent laparotomy was the procedure of first choice. However, immediate head CT scan, then emergency craniotomy, may be justified in hemodynamically stable MT and HI patients with a US score < 3 (n = 98). Appropriate decision making can be applied to decide which procedure is most exigent.
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Abstract
The evaluation, management, and final outcome of 34 patients with blunt gastrointestinal injury (BGI) were reviewed. Initial absence of symptoms and signs led to two delayed diagnoses. Sonography provided 80% (12/15) positive-predictive value, and three false-negative patients were subsequently detected by diagnostic peritoneal lavage (DPL). Besides repeated clinical surveillance, screening by sonography complemented with DPL provided early detection of blunt bowel injury in trauma patients. In the outcome analysis, BGI patients with high injury-severity scores, intraoperative hypotension, or accompanying major medical diseases were associated significantly with increased risk of infectious complications (P < .05).
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Sequential cytogenetic alterations in hamster oral keratinocytes during DMBA-induced oral carcinogenesis. EUROPEAN JOURNAL OF CANCER. PART B, ORAL ONCOLOGY 1994; 30B:252-64. [PMID: 7950840 DOI: 10.1016/0964-1955(94)90007-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Using the hamster cheek pouch oral cancer model, we have performed a comprehensive analysis of the cytogenetic changes in hamster oral keratinocytes during 7,12-dimethylbenz[a]anthracene (DMBA)-induced carcinogenesis. Tumour induction in the hamster cheek pouch required repeated application of the carcinogen for 14 weeks. We have found that this hamster oral cancer model to be suitable for cytogenetic studies. Unlike human oral cancers where chromosome breaks have been shown, this is only infrequently observed in DMBA-treated hamster oral keratinocytes. Of importance is the finding that at the beginning of the second week of DMBA treatment, there is a significant increase of karyotypes demonstrating tetraploid or near-tetraploidy. We propose that the significant increase in hamster oral keratinocytes exhibiting tetraploidy be further evaluated as a marker of premalignancy/malignancy.
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Ultrasonography for the evaluation of hemoperitoneum during resuscitation: a simple scoring system. THE JOURNAL OF TRAUMA 1994; 36:173-7. [PMID: 8114130 DOI: 10.1097/00005373-199402000-00003] [Citation(s) in RCA: 94] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
To assess the need for therapeutic laparotomy in patients with blunt abdominal trauma (BAT), ultrasonography (US) and a simple US scoring system were used to estimate the amount of hemoperitoneum during resuscitation. In group I (BAT with a US score > or = 3), 24 of 25 patients (96%) required therapeutic laparotomy. In group II (BAT with a US score < 3), therapeutic laparotomy was required in only 9 of 24 patients (38%); nonsurgical treatment may be justified in hemodynamically stable patients. Appropriate decisions can be made to perform urgent laparotomy when intra-abdominal bleeding is the culprit in BAT patients. Unnecessary laparotomy can be avoided when the major site of blood loss is not in the abdomen. Ultrasonography, an initial rapid screening procedure in BAT patients, is useful for trauma surgeons in decision making during resuscitation.
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New adenosine kinase inhibitors with oral antiinflammatory activity: synthesis and biological evaluation. J Med Chem 1993; 36:3424-30. [PMID: 8230132 DOI: 10.1021/jm00074a024] [Citation(s) in RCA: 61] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Several 5-iodotubercidin analogues in the pyrazolo[3,4-d]pyrimidine ring system were synthesized as potential inhibitors of adenosine kinase by a direct Lewis acid-catalyzed glycosylation procedure using both the preformed carbohydrate and the heterocyclic base as starting materials. The 5'-hydroxyl, -chloro, -azido, -deoxy, -amino, and -fluoro derivatives were prepared and evaluated in three systems for biological activity relative to adenosine, the true substrate, and 5-iodotubercidin, a known inhibitor. First, each compound was studied kinetically for inhibition of purified human placental adenosine kinase activity. The order of potency was: iodotubercidin > hydroxyl > amino > or = deoxy > fluoro > chloro >> azido. The Ki values for the 5'-hydroxyl and 5'-amino compounds, the two most potent inhibitors, were 80 and 150 nM, respectively. The inhibition appeared to be essentially competitive in nature, although a noncompetitive component of significance for the more potent inhibitors cannot be ruled out. Second, a bioassay was conducted in which the toxicity of 6-methylmercaptopurine riboside toward human CEM lymphoblasts was reversed by varying concentrations of the compounds. The order of effectiveness of the compounds in this system, representing a functional inhibition of adenosine kinase in cultured cells, was about the same as that with the purified enzyme, except that the 5'-chloro and 5'-fluoro compounds were ineffective. Third, the 5'-hydroxyl derivative was evaluated in vivo in a rat pleurisy inflammation model and displayed biological activity at a dose of 30 mg/kg given orally. Finally, the in vitro toxicity of each compound was assessed in CEM lymphoblasts. Results indicated that the two most potent inhibitors in the pyrazolo[3,4-d]pyrimidine ring system, the 5'-hydroxyl (7) and the 5'-amino (20), were 15-fold and 75-fold, respectively, less growth inhibitory than 5-iodotubercidin.
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Abstract
Phensuximide (PSX) is an antiepileptic agent which has been shown to induce hemorrhagic cystitis and mild nephrotoxicity following repeated administration in man or rats or when acutely administered to phenobarbital-pretreated rats. The purpose of this study was to explore the role of para-hydroxylation of the phenyl group of PSX in PSX-induced urotoxicity. Two PSX derivatives, 2-(4-fluorophenyl)-N-methylsuccinimide (FMPS) and N-methyl-2-(4-methylphenyl)succinimide (MMPS), were synthesized and evaluated for urotoxic potential. Male Fischer 344 rats (four rats/group) were administered intraperitoneally (i.p.) a succinimide (0.4 or 1.0 mmol/kg) or vehicle and renal function monitored for 48 h. In a separate experiment, rats were pretreated with phenobarbital (75 mg/kg/day; 3 days, i.p.) prior to succinimide or succinimide vehicle. In non-phenobarbital pretreated rats, acute FMPS or MMPS treatment had little effect on renal function or morphology at the doses tested. Hematuria (+) was noted in the FMPS (1.0 mmol/kg) group on post-treatment day 2. However, in the phenobarbital-pretreated rats, FMPS (0.4 or 1.0 mmol/kg) induced marked hematuria (++) and increased proteinuria while having little or no effect on other renal functional parameters or renal morphology. At killing, bladders of treated rats were distended with bloody urine and exhibited hemorrhagic areas within the bladder wall. In phenobarbital-pretreated rats, MMPS administration had little effect on any renal functional parameter measured or urological morphology. These results suggest that para-hydroxylation does not contribute to the hemorrhagic cystitis induced by PSX.
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N-(3,5-dichlorophenyl)succinimide nephrotoxicity: evidence against the formation of nephrotoxic glutathione or cysteine conjugates. Toxicology 1991; 68:307-25. [PMID: 1680251 DOI: 10.1016/0300-483x(91)90077-e] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
The agricultural fungicide N-(3,5-dichlorophenyl)succinimide (NDPS) induces nephrotoxicity via one or more metabolites. Previous studies suggested that glutathione is important for mediating NDPS-induced nephropathy. The purpose of this study was to examine the possibility that a glutathione or cysteine conjugate of NDPS or an NDPS metabolite might be the penultimate or ultimate nephrotoxic species. In one set of experiments, male Fischer 344 rats were administered intraperitoneally (i.p.) NDPS (0.4 or 1.0 mmol/kg) 1 h after pretreatment with the gamma glutamyltranspeptidase inhibitor AT-125 (acivicin) (10 mg/kg, i.p.) and renal function was monitored at 24 and 48 h. In general, AT-125 pretreatment had few effects on NDPS-induced nephropathy. In a second set of experiments, rats were treated i.p. or orally (p.o.) with a putative glutathione (S-(2-(N-(3,5-dichlorophenyl)succinimidyl)glutathione (NDPSG), a cysteine (S-(2-(N-(3,5-dichlorophenyl)succinimidyl)cysteine (NDPSC) (as the methyl ester) or N-acetylcysteine (S-(2-(N-(3,5-dichlorophenyl)succinimidyl)-N-acetylcysteine (NDPSN) conjugate of NDPS (0.2, 0.4 or 1.0 mmol/kg) or vehicle and renal function was monitored at 24 and 48 h. An intramolecular cyclization product of NDPSC, 5-carbomethoxy-2-(N-(3,5-dichlorophenyl)carbamoylmethyl)-1,4-th iazane-3-one (NDCTO) was also examined for nephrotoxic potential. None of the compounds produced toxicologically important changes in renal function or morphology. The in vitro ability of the conjugates to alter organic ion accumulation by cortical slices was also examined. All of the conjugates tested caused a reduction in p-aminohippurate (PAH) accumulation at a conjugate bath concentration of 10(-4) M, but none of the conjugates reduced tetraethylammonium (TEA) uptake. In a third experiment, the ability of the cysteine conjugate beta-lyase inhibitor aminooxyacetic acid (AOAA) (0.5 mmol/kg, i.p.) to alter the nephrotoxicity induced by two NDPS metabolites, N-(3,5-dichlorophenyl)-2-hydroxysuccinimide (NDHS) or N-(3,5-dichlorophenyl)-2-hydroxysuccinamic acid (NDHSA) (0.2 mmol/kg, i.p.), was examined. AOAA pretreatment had no effect on NDHS- or NDHSA-induced nephrotoxicity. These results do not support a role for a glutathione or cysteine conjugate of NDPS or and NDPS metabolite as being the penultimate or ultimate nephrotoxic species.
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Abstract
Phensuximide (PSX) is a 2-arylsuccinimide useful in the treatment of absence seizures. PSX is a mild urotoxicant and is structurally related to N-phenylsuccinimide (NPS) and its antifungal derivatives. Since substitution of the phenyl ring of NPS with chloro or tert-butyl groups can produce compounds with enhanced nephrotoxic potential, it was felt that similar substitutions on the phenyl ring of PSX also might produce derivatives with enhanced nephrotoxic potential. Three derivatives of PSX were prepared and tested: 2-(3-chlorophenyl)-N-methylsuccinimide (CPMS); 2-(4-tert-butylphenyl)-N-methylsuccinimide (BPMS) and 2-(3,5-dichlorophenyl)-N-methylsuccinimide (DPMS). In one set of experiments, male Fischer 344 rats were administered a single intraperitoneal (i.p.) injection of a succinimide (0.4 or 1.0 mmol kg-1) or vehicle (sesame oil, 2.5 ml kg-1) and renal function monitored at 24 and 48 h. Only minor changes in renal function were noted with the PSX derivatives. BPMS and DPMS (1.0 mmol kg-1) treatment induced mild renal tubular necrosis and thickening of the glomerular membranes. However, no significant morphological changes were noted in ureters, bladder or liver in any treatment group. In a second set of experiments, rats were pretreated with phenobarbital (75 mg kg-1 day-1, i.p., 3 days) followed by a single i.p. injection of DPMS (0.4 or 1.0 mmol kg-1) or DPMS vehicle. Renal function was monitored as before. Phenobarbital pretreatment did not markedly enhance the functional nephrotoxicity induced by DPMS (0.4 mmol), but tubular necrosis was greater than observed in non-phenobarbital-pretreated rats receiving DPMS (1.0 mmol kg-1). In addition, hepatotoxicity was observed as the appearance of numerous non-staining vacuoles in hypertrophied hepatocytes. In the phenobarbital plus DPMS (1.0 mmol kg-1) treatment group, all rats died by 48 h. Prior to death, rats exhibited increased proteinuria (+3), hematuria (+3) and blood urea nitrogen concentration. At 24 h, kidneys from rats treated with phenobarbital plus DPMS (1.0 mmol kg-1) exhibited extensive proximal tubular necrosis and numerous glomeruli with thickened membranes. Hepatotoxicity was more pronounced than with phenobarbital plus DPMS (0.4 mmol kg-1) at 48 h and urinary bladders had focal areas of erythrocytes pooling below the epithelial lining. These results demonstrate that although NPS and PSX are structural analogs, chemical substitutions that enhance the nephrotoxic potential of NPS do not have a similar effect on PSX. In addition, DPMS can induce urotoxicity in a manner similar to that observed for PSX and probably induces toxicity via one or more metabolites.
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