Effects of taurine on vascular tone.

Taurine is widely distributed at high concentrations in mammalian tissues, and it plays an important role in a wide range of biological effects including modulation of cardiovascular functions. This review summarizes the role of taurine in vascular tone and blood pressure modulation based on experimental and human studies. It is well established that supplementation of taurine prevents development of hypertension in several animal models and p.o. taurine administration reduces blood pressure in hypertensive patients. Both central and peripheral actions of taurine may be involved in its hypotensive effects. In isolated animal arteries, taurine exerts vasodilation through endothelium-dependent and independent mechanisms. Several studies showed that taurine relaxed various animal arteries through opening potassium channels. We have recently shown that taurine relaxes human internal mammary and radial arteries by opening large conductance Ca2+-activated K+ channels. To date, the molecular mechanism(s) involved in the vascular effects of taurine are largely unknown and require further investigation. Clarifying the mechanisms in which taurine affects the vascular system may facilitate the development of therapeutic and/or diet-based strategies to reduce the burden of vascular diseases.

Hydroxychloroquine induces endothelium-dependent and endothelium-independent relaxation of rat aorta.

BACKGROUND: Hydroxychloroquine (HCQ) is an antimalarial that is widely used in the management of rheumatoid arthritis and other autoimmune diseases. In this study, we aimed to examine the vascular effects of HCQ on rat aorta (RA). METHODS: The RA rings were suspended in isolated organ baths and tension was recorded isometrically. HCQ-induced relaxations were tested in the presence of the nitric oxide synthase inhibitor, nitro-L-arginine methyl ester (L-NAME, 100 mM); the cyclooxygenase enzyme inhibitor, indomethacin (10 mM); the calcium (Ca2+) ion channel blocker, nilvadipine (10 µM); and the K+ ion channel inhibitors, tetraethylammonium (1 mM), glibenclamide (10 mM), 4-aminopyridine (1 mM), and barium chloride (30 mM). The effect of HCQ on Ca2+ channels was examined using Ca2+-free Krebs solution, and adding calcium chloride (CaCl2 , 10-5- 10-2 M) cumulatively to baths incubated with HCQ. RESULTS: Removing the endothelium resulted in less relaxation of RA rings compared to endothelium-intact rings (p < 0.05). The effect of endothelium was supported by using L-NAME where HCQ produced-vasorelaxation was decreased (p < 0.05). The contraction of vascular rings was inhibited to a significant degree following the addition of CaCl2 , PE, or KCl on HCQ-incubated RA rings (p < 0.05). The incubation of the RA rings with the Ca2+ channel blocker, the K+ channel blockers, and the COX inhibitor, indomethacin did not significantly affect vascular relaxation induced by HCQ. DISCUSSION: HCQ produced relaxation of RA rings. The relaxation mechanism differs according to the concentration of HCQ. At con-centrations of 10-6 and 10-5 M, the relaxation is endothelium-dependent and mediated by NO. We strongly suggest that Ca2+ channel inhibition is involved at concentrations of 10-5 and 10-4 M, as well as NO.

An unusual presentation of pulmonary artery sarcoma: Several pseudoaneurysms with massive hemoptysis.

A 53-year-old woman was admitted to the emergency department with sudden onset of massive hemoptysis. She had previous history of dyspnea and cough for two months. She had no history of chronic disease, smoking, or use of anticoagulant and antiplatelet drugs. On arrival, she was tachycardic and tachypneic, but her body temperature was normal. Chest X-ray showed enlarged right hilus and multiple nodular opacities predominantly in the left lung basis. Computed tomography (CT) scan of the chest demonstrated massive intraluminal filling defect extending from the right pulmonary artery through the main and left pulmonary arteries. Pulmonary artery sarcoma (PAS) was the preliminary imaging-based diagnosis. However, CT also revealed presence of several pseudoaneurysms arising from the distal branches of the left pulmonary artery encased by metastatic nodules. Although hemoptysis is an uncommon presentation for patients with PAS, accompanied pseudoaneurysms were the main reason for massive hemoptysis. Differentiation of PAS from bland thromboembolism could be challenging on CT. Herein reported case provides an additional imaging feature that may utilize differentiating pulmonary artery sarcoma from bland thrombus.

Propofol Relaxes Isolated Rat Aorta through BKCa Activation.

BACKGROUND: Propofol is an intravenous anesthetic that can be used for the induction and maintenance of anesthesia. In the present study, it was aimed to investigate the mechanism of vasodilator action of propofol in the rat aorta (RA). METHODS: The RA rings were suspended in isolated organ baths and tension was recorded isometrically. First, potassium chloride (KCl) and phenylephrine (PE) were added to organ baths to form precontraction. When the precontractions were stable, propofol (1, 10, and 100 µM) was added cumulatively to the baths. The antagonistic effect of propofol on KCl (45 mM), PE (1 µM), 5-hydroxytryptamine (5-HT) (30 µM), and calcium chloride (CaCl2) (10 µM to 10 mM) induced contractions in the vascular rings were investigated. Propofol-induced relaxations were also tested in the presence of the K+ channel inhibitors tetraethylammonium (TEA, 1 mM), glibenclamide (GLI, 10 µM), 4-aminopyridine (4-AP, 1 mM), and barium chloride (BaCl2, 30 µM). RESULTS: Preincubation with propofol (1, 10, and 100 µM) did not affect the basal tone but inhibited the contraction induced by KCl, PE, 5-HT, and CaCl2-induced contractions. Propofol-induced relaxation was not effected by 4-AP, GLI, and BaCl2. However, TEA inhibited propofol-induced relaxations significantly. CONCLUSIONS: The propofol induces relaxation in contracted RA and inhibits KCl, PE, 5-HT, and CaCl2-induced contractions. The results demonstrate that the mechanism of action of propofol-induced vasodilation in the RA may be related to large conductance Ca2+-activated K+ channel activation.

Propofol-Induced Vasodilation in Human Internal Mammary Artery: Role of Potassium Channels.

OBJECTIVES: The aim of this study was to investigate the vascular effects and mechanisms of propofol in the human internal mammary artery (IMA). DESIGN: In vitro experimental study. SETTING: The study was conducted in the research laboratory of a pharmacology department. PARTICIPANTS: IMA segments were obtained from 52 patients undergoing coronary artery bypass surgery. INTERVENTIONS: The IMA rings were suspended in isolated organ baths, and the changes in the tension were isometrically recorded. The antagonistic effect of propofol (1 µM, 10 µM, and 100 µM) on contractions induced by potassium chloride (45 mM), phenylephrine (1 µM), 5-hydroxytryptamine (30 µM), and calcium chloride (10 µM-10 mM) was investigated. The relaxations induced by propofol also were tested in the presence of the nitric oxide synthase inhibitor, nitro-L-arginine methyl ester (100 mM); the cyclooxygenase inhibitor, indomethacin (10 mM); and the potassium ion channel inhibitors, tetraethylammonium (1 mM), iberiotoxin (20 nM), glibenclamide (10 µM), 4-aminopyridine (1 mM), and barium chloride (30 µM). MEASUREMENTS AND MAIN RESULTS: Propofol caused a significant concentration-dependent vasorelaxation, which was endothelium independent. It inhibited the contractions induced by potassium chloride, phenylephrine, 5-hydroxytryptamine, and calcium chloride (p < 0.001), but it did not affect the basal tension. Propofol-induced relaxation was significantly inhibited by iberiotoxin and tetraethylammonium (p < 0.001); however, it was not affected by 4-aminopyridine, glibenclamide, and barium chloride. CONCLUSION: This study clearly reveals that propofol relaxes the IMA, and propofol-induced vasodilation may be related to large conductance calcium ion-activated potassium ion channel activation. Propofol use in coronary artery bypass surgery can be valuable via its favorable vasodilator effect to overcome perioperative vasospasm of IMA.

Taurine relaxes human radial artery through potassium channel opening action.

The vascular actions and mechanisms of taurine were investigated in the isolated human radial artery (RA). RA rings were suspended in isolated organ baths and tension was recorded isometrically. First, a precontraction was achieved by adding potassium chloride (KCl, 45 mM) or serotonin (5-hydroxytryptamine, 5-HT, 30 µM) to organ baths. When the precontractions were stable, taurine (20, 40, 80 mM) was added cumulatively. Antagonistic effect of taurine on calcium chloride (10 µM to 10 mM)-induced contractions was investigated. Taurine-induced relaxations were also tested in the presence of the K+ channel inhibitors tetraethylammonium (1 mM), glibenclamide (10 µM) and 4-aminopyridine (1 mM). Taurine did not affect the basal tone but inhibited the contraction induced by 5-HT and KCl. Calcium chloride-induced contractions were significantly inhibited in the presence of taurine (20, 40, 80 mM) (p<0.05). The relaxation to taurine was inhibited by tetraethylammonium (p<0.05). However, glibenclamide and 4-aminopyridine did not affect taurine-induced relaxations. Present experiments show that taurine inhibits 5-HT and KCl-induced contractions in RA, and suggest that large conductance Ca2+-activated K+ channels may be involved in taurine-induced relaxation of RA.

Evaluating the performance of ChatGPT in answering questions related to urolithiasis.

PURPOSE: ChatGPT is an artificial intelligence (AI) program with natural language processing. We analyzed ChatGPT's knowledge about urolithiasis whether it can be used to inform patients about urolithiasis. METHODS: Frequently asked questions (FAQs) about urolithiasis on the websites of urological associations and hospitals were analyzed. Also, strong recommendation-level information was gathered from the urolithiasis section of the European Association of Urology (EAU) 2022 Guidelines. All questions were asked in order in ChatGPT August 3rd version. All answers were evaluated separately by two specialist urologists and scored between 1 and 4, where 1: completely correct, 2: correct but inadequate, 3: a mix of correct and misleading information, and 4: completely incorrect. RESULTS: Of the FAQs, 94.6% were answered completely correctly. No question was answered completely incorrectly. All questions about general, diagnosis, and ureteral stones were graded as 1. Of the 60 questions prepared according to the EAU guideline recommendations, 50 (83.3%) were evaluated as grade 1, and 8 (13.3%) and 2 (3.3%) as grade 3. All questions related to general, diagnostic, renal calculi, ureteral calculi, and metabolic evaluation received the same answer the second time they were asked. CONCLUSION: Our findings demonstrated that ChatGPT accurately and satisfactorily answered more than 95% of the questions about urolithiasis. We conclude that applying ChatGPT in urology clinics under the supervision of urologists can help patients and their families to have better understanding on urolithiasis diagnosis and treatment.

Evaluating the performance of ChatGPT in answering questions related to pediatric urology.

INTRODUCTION: Artificial intelligence is advancing in various domains, including medicine, and its progress is expected to continue in the future. OBJECTIVE: This research aimed to assess the precision and consistency of ChatGPT's responses to commonly asked inquiries related to pediatric urology. MATERIALS AND METHODS: We examined commonly posed inquiries regarding pediatric urology found on urology association websites, hospitals, and social media platforms. Additionally, we referenced the recommendations tables in the European Urology Association's (EAU) 2022 Guidelines on Pediatric Urology, which contained robust data at the strong recommendation level. All questions were systematically presented to ChatGPT's May 23 Version, and two expert urologists independently assessed and assigned scores ranging from 1 to 4 to each response. RESULTS: A hundred thirty seven questions about pediatric urology were included in the study. The answers to questions resulted in 92.0% completely correct. The completely correct rate in the questions prepared according to the strong recommendations of the EAU guideline was 93.6%. No question was answered completely wrong. The similarity rates of the answers to the repeated questions were between 93.8% and 100%. CONCLUSION: ChatGPT has provided satisfactory responses to inquiries related to pediatric urology. Despite its limitations, it is foreseeable that this continuously evolving platform will occupy a crucial position in the healthcare industry.

Evaluating ChatGPT ability to answer urinary tract Infection-Related questions.

INTRODUCTION: For the first time, the accuracy and proficiency of ChatGPT answers on urogenital tract infection (UTIs) were evaluated. METHODS: The study aimed to create two lists of questions: frequently asked questions (FAQs, public-based inquiries) on relevant topics, and questions based on guideline information (guideline-based inquiries). ChatGPT responses to FAQs and scientific questions were scored by two urologists and an infectious disease specialist. Quality and reliability of all ChatGPT answers were checked using the Global Quality Score (GQS). The reproducibility of ChatGPT answers was analyzed by asking each question twice. RESULTS: All in all, 96.2 % of FAQs (75/78 inquiries) related to UTIs were correctly and adequately answered by ChatGPT, and scored GQS 5. None of the ChatGPT answers were classified as GQS 2 and GQS 1. Moreover, FAQs about cystitis, urethritis, and epididymo-orchitis were answered by ChatGPT with 100 % accuracy (GQS 5). ChatGPT answers for EAU urological infections guidelines showed that 61 (89.7 %), 5 (7.4 %), and 2 (2.9 %) ChatGPT responses were scored GQS 5, GQS 4, and GQS 3, respectively. None of the ChatGPT responses for EAU urological infections guidelines were categorized as GQS 2 and GQS 1. Comparison of mean GQS values of ChatGPT answers for FAQs and EAU urological guideline questions showed that ChatGPT was similarly able to respond to both question groups (p = 0.168). The ChatGPT response reproducibility rate was highest for the FAQ subgroups of cystitis, urethritis, and epididymo-orchitis (100 % for each subgroup). CONCLUSION: The present study showed that ChatGPT gave accurate and satisfactory answers for both public-based inquiries, and EAU urological infection guideline-based questions. Reproducibility of ChatGPT answers exceeded 90% for both FAQs and scientific questions.

The relaxation effect of endocannabinoid anandamide on isolated rat bladder and vas deferens tissues and possible mechanisms.

BACKGROUND: The endocannabinoid system plays important roles in various systems, including the genitourinary system; however, its mechanism of action is not fully understood. OBJECTIVES: This study aimed to investigate the direct relaxant effects of anandamide and its possible mechanisms in isolated rat bladder and vas deferens tissues. METHODS: Twenty-one adult male Wistar albino rats were used. Bladder and vas deferens (prostatic and epididymal portions) tissues were mounted in 10 mL of organ baths. Relaxation responses to anandamide were recorded at 3 and 10 µM concentrations. After the rest period, the procedures were repeated in the presence of cannabinoid (CB) and vanilloid receptor antagonists, various potassium channel blockers, cyclo-oxygenase, and nitric oxide synthase inhibitors. In different tissues to investigate the Ca2+-channel antagonistic effect of anandamide, concentration-response curves to CaCl2 were obtained in the absence and presence of anandamide. RESULTS: Anandamide caused a significant relaxation response in the bladder and epididymal vas deferens tissues, but not in the prostatic portion. The effect of anandamide was antagonized in the presence of the CB1 antagonist AM251 or the non-selective potassium channel blocker tetraethylammonium in bladder tissue. In the epididymal vas deferens, anandamide significantly inhibited the calcium contraction responses, especially at high concentrations. The CB2 antagonist AM630 reversed this inhibition. CONCLUSIONS: The results show that anandamide has a direct relaxant effect on the isolated rat bladder and epididymal vas deferens. Anandamide triggers different mechanisms in different types of tissues, and further studies are needed to elucidate the mechanism of action of anandamide.

The Role of Cannabinoid-1 Receptor Ligands in the Ovalbumin-Induced Mouse Model of Allergic Asthma: Is It Related to Transient Receptor Potential Vanilloid-1 Channels?

Objectives: The aim of this study was to investigate the role of cannabinoid (CB1) receptors on airway inflammation and hypersensitivity in allergic asthma and the potential interactions with TRPV1 channels. Materials and Methods: BALB/c mice were sensitized and provoked with ovalbumin to create a model of allergic asthma. CB1 selective agonist arachidonoyl 2'-chloroethylamide (ACEA) was administered intraperitoneally at doses of 0.5, 3, and 5 mg/kg. Receptor antagonism studies were performed utilizing selective CB1 antagonists AM251 at a dose of 3 mg/kg. TRPV1 channel was selectively blocked by capsazepine at a dose of 2.5 mg/kg. Penh values were recorded in vivo by a whole-body plethysmograph under methacholine challenge. Inflammatory cell count was performed in bronchoalveolar lavage fluid (BALF). Serum levels of proinflammatory cytokines were measured by Enzyme-Linked ImmunoSorbent Assay (ELISA). Inflammation in the lung tissue was scored histopathologically. Statistical significance was determined using one-way analysis of variance or Kruskal-Wallis test and expressed as p<0.05. Results: In sensitized animals, provocation with inhaled ovalbumin increased Penh values, serum interleukin (IL)-4, IL-5, IL-13 levels, eosinophil, neutrophil, lymphocyte, macrophage counts in BALF, and inflammation in the lung tissue. ACEA applications did not significantly alter Penh values, BALF inflammatory cell levels, and histological changes related to inflammation in the lung tissue according to the disease group; however, only at a dose of 5 mg/kg, it reduced the levels of the inflammatory cytokine IL-4. AM251 decreased Penh values, eosinophil and neutrophil migration in BALF, and inflammation score of lung tissue compared with the disease group. Although BALF inflammatory cell levels and Penh values were higher in the AM251+ACEA group than in the AM251 group, the differences were insignificant. In the CPZ+ACEA group, Penh values were significantly higher, and serum IL-4 and IL-13 levels and BALF eosinophil counts were lower than that in the CPZ group. Conclusions: This study demonstrated an important role of the CB1 receptors in allergic asthma. CB1 antagonism reduced airway hyperresponsiveness and inflammation and showed immunomodulatory effects. The effect of the CB1 agonist ACEA on asthma does not appear to be related to TRPV1 channels.

Assessing the Performance of Chat Generative Pretrained Transformer (ChatGPT) in Answering Andrology-Related Questions.

OBJECTIVE: The internet and social media have become primary sources of health information, with men frequently turning to these platforms before seeking professional help. Chat generative pretrained transformer (ChatGPT), an artificial intelligence model developed by OpenAI, has gained popularity as a natural language processing program. The present study evaluated the accuracy and reproducibility of ChatGPT's responses to andrology-related questions. METHODS: The study analyzed frequently asked andrology questions from health forums, hospital websites, and social media platforms like YouTube and Instagram. Questions were categorized into topics like male hypogonadism, erectile dysfunction, etc. The European Association of Urology (EAU) guideline recommendations were also included. These questions were input into ChatGPT, and responses were evaluated by 3 experienced urologists who scored them on a scale of 1 to 4. RESULTS: Out of 136 evaluated questions, 108 met the criteria. Of these, 87.9% received correct and adequate answers, 9.3% were correct but insufficient, and 3 responses contained both correct and incorrect information. No question was answered completely wrong. The highest correct answer rates were for disorders of ejaculation, penile curvature, and male hypogonadism. The EAU guideline-based questions achieved a correctness rate of 86.3%. The reproducibility of the answers was over 90%. CONCLUSION: The study found that ChatGPT provided accurate and reliable answers to over 80% of andrology-related questions. While limitations exist, such as potential outdated data and inability to understand emotional aspects, ChatGPT's potential in the health-care sector is promising. Collaborating with health-care professionals during artificial intelligence model development could enhance its reliability.

Evaluating the performance of ChatGPT in answering questions related to benign prostate hyperplasia and prostate cancer.

BACKGROUND: The aim of this study was to evaluate the accuracy and reproducibility of ChatGPT's answers to frequently asked questions about benign prostate hyperplasia (BPH) and prostate cancer. METHODS: Frequently asked questions on the websites of urology associations, hospitals, and social media about prostate cancer and BPH were evaluated. Also, strong recommendation-level data were noted in the recommendations tables of the European Urology Association (EAU) 2022 Guidelines on Prostate Cancer and Management of Non-neurogenic Male Lower Urinary Tract Symptoms sections. All questions were asked in order in ChatGPT Mar 23 Version. All answers were evaluated separately by two specialist urologists and scored between 1-4. RESULTS: Forty questions about BPH and 86 questions about prostate cancer were included in the study. The answers to all BPH-related questions resulted in 90.0% completely correct. This rate for questions about prostate cancer was 94.2%. The completely correct rate in the questions prepared according to the strong recommendations of the EAU guideline was 77.8% for BPH and 76.2% for prostate cancer. The similarity rates of the answers to the repeated questions were 90.0% and 93% for questions related to BPH and prostate cancer, respectively. CONCLUSIONS: ChatGPT has given satisfactory answers to questions about BPH and prostate cancer. Although it has limitations, it can be predicted that it will take an important place in the health sector in the future, as it is a constantly evolving platform. ChatGPT was able to provide helpful information about BPH and prostate cancer, although it is not perfect. It is constantly getting better, and may become an important resource in the healthcare field in the future.

Many faces of torsion in pediatric female pelvis.

Pediatric patients of various ages, from infancy through adolescence, can have ovarian torsion. Torsion may not only be confined to the ovaries but may also involve the isolated cyst, tube, and even the uterus. In this pictorial review, we review the spectrum of torsion in pediatric (from infants to adolescents) female pelvis, emphasizing imaging methods.

Case Report: Imaging-Guided Percutaneous Catheterization and Microwave Ablation of a Bone Hydatid Cyst with Soft-Tissue Component.

Cystic echinococcosis (CE) of the bone is a rare disease compared with CE of the viscera, and the most involved bony structures are the spine and the pelvis. Both the diagnosis and the treatment of bone CE are challenging for several reasons. The combination of surgery and antimicrobial therapy is the most common approach, the results are far from adequate. Luckily, percutaneous treatment has appeared on the horizon for bone lesions as a more practical option with fewer drawbacks in light of current reports. This article deals with the successful result of ablation-assisted percutaneous treatment of a bone CE lesion and a soft tissue CE lesion treated by modified catheterization technique in a male patient with left hip pain that was unresponsive to previous surgery for CE.

The effect of intravesical acetylsalicylic acid instillation on tissue prostaglandin levels after partial bladder outlet obstruction in rabbits.

AIMS: To examine whether obstruction changes the expression of prostaglandins (PGs) in bladder, intravesical low-dose aspirin could be used as a new route of drug administration, this way of administration influences PGs' expression, and contractile function of the bladder is protected after treatment. METHODS: Eighteen rabbits were divided into three groups. Sham-operated group (group 1) included 6 rabbits. Twelve rabbits were partially obstructed for 70 days. Six of these 12 rabbits not receiving any treatment constituted obstructed group (group 2). The remaining six rabbits received 2 mg/kg/day aspirin (group 3). One rabbit in each group was evaluated on 1st, 7th, 14th, 28th, 42nd, and 70th days following obstructive surgery. After scarification, the percentage of collagenous area and concentrations of PGE2 and PGF2-alpha were measured. Contractile responses to field stimulation (EFS), carbachol, and potassium chloride (KCl) were determined. RESULTS: Wet tissue PGE2 and PGF2-alpha levels were higher in obstructed group than the other groups. Aspirin decreased the percentage of collagenous area in group 3 compared to the group 2, but this difference was not statistically significant. The strips from aspirin groups resulted in better contractile response to cholinergic stimulation with KCl, but this difference was not statistically significant between the obstructed and aspirin groups. Similarly, carbachol did not elicit significantly greater concentration-dependent contraction in strips from obstructed group compared to those from aspirin groups. Maximum responses to EFS were not significant in aspirin group compared to those from obstructed group. CONCLUSIONS: Intravesical aspirin may have protective effect on partially obstructed bladder.

Percutaneous Treatment of Bone Hydatid Cyst.

Cystic echinococcosis (CE) may be encountered in almost every site of the body, but bone involvement is relatively rare. The vertebral column and pelvis are the most affected areas. The combined medical and surgical approach is the main treatment option in current literature. Although percutaneous treatment of CE cysts located in the liver, spleen, kidney, and soft tissues has become a serious alternative to surgery, there is no bone CE cyst treated percutaneously in the literature. This case report aims to point out that percutaneous treatment can be an effective treatment choice and alternative to surgery.

Potassium channels in vascular smooth muscle: a pathophysiological and pharmacological perspective.

Potassium (K+ ) ion channel activity is an important determinant of vascular tone by regulating cell membrane potential (MP). Activation of K+ channels leads to membrane hyperpolarization and subsequently vasodilatation, while inhibition of the channels causes membrane depolarization and then vasoconstriction. So far five distinct types of K+ channels have been identified in vascular smooth muscle cells (VSMCs): Ca+2 -activated K+ channels (BKC a ), voltage-dependent K+ channels (KV ), ATP-sensitive K+ channels (KATP ), inward rectifier K+ channels (Kir ), and tandem two-pore K+ channels (K2 P). The activity and expression of vascular K+ channels are changed during major vascular diseases such as hypertension, pulmonary hypertension, hypercholesterolemia, atherosclerosis, and diabetes mellitus. The defective function of K+ channels is commonly associated with impaired vascular responses and is likely to become as a result of changes in K+ channels during vascular diseases. Increased K+ channel function and expression may also help to compensate for increased abnormal vascular tone. There are many pharmacological and genotypic studies which were carried out on the subtypes of K+ channels expressed in variable amounts in different vascular beds. Modulation of K+ channel activity by molecular approaches and selective drug development may be a novel treatment modality for vascular dysfunction in the future. This review presents the basic properties, physiological functions, pathophysiological, and pharmacological roles of the five major classes of K+ channels that have been determined in VSMCs.

The vasodilator effect of testosterone on the human internal spermatic vein and its relation to varicocele grade.

PURPOSE: Several animal and human studies in vivo and in vitro indicate that testosterone has vasodilatory effects on different vessels. However, the effect of testosterone on the internal spermatic vein is not clear. In addition, the role of testosterone in the pathophysiology of varicocele is not established. We investigated the effect of testosterone on the internal spermatic vein in vitro in patients with varicocele and analyzed its relation to varicocele grade. MATERIALS AND METHODS: Isolated internal spermatic veins were collected from patients who underwent varicocelectomy and orchiectomy. The preparations (3 to 4 mm rings) were mounted in an organ bath containing 10 ml Krebs-Henseleit solution on an L-shaped brace for tension measurement along the former circumferential axis. Changes in venous tension in the presence of testosterone (0.1 to 300 microM) were recorded isometrically by a force displacement transducer. RESULTS: Cumulative concentrations of testosterone (0.1 to 300 microM) elicited concentration dependent relaxation of 45 mM KCl induced active tone in the internal spermatic vein (mean +/- SEM 60.97% +/- 5.05% of the KCl induced contraction). Relaxation to testosterone (1 to 300 microM) was significantly higher in 5 cases of grades 0 and 1 varicocele than in 15 of grades 2 and 3 varicocele (maximum relaxation response 78.58% +/- 8.25% vs 55.10% +/- 5.3% of the KCl induced contraction). CONCLUSIONS: To our knowledge the current report is the first to describe testosterone induced relaxation of the human internal spermatic vein. The vasodilatory effect of testosterone on the human internal spermatic vein decreases in high grade varicoceles.

Comparison of three different second-line quadruple therapies including bismuth subcitrate in Turkish patients with non-ulcer dyspepsia who failed to eradicate Helicobacter pylori with a 14-day standard first-line therapy.

BACKGROUND AND AIM: Many studies have reported poor results with standard first-line treatment for Helicobacter pylori. Second-line regimens that may overcome bacterial resistance can minimize side-effects and optimize compliance. The aim of this study was to evaluate the efficacy of proton pump inhibitor (PPI) and bismuth subcitrate-based quadruple therapy, after failure of a PPI plus clarithromycin and amoxicillin as first-line therapy. METHODS: Patients who failed to eradicate the infection after initial therapy were randomly separated into three groups. The first group received lansoprazole, bismuth subcitrate, metronidazole and amoxicillin (LBMA); in the second group metronidazole was replaced by tetracycline (LBTA); and the third group was given metronidazole and tetracycline in addition to same doses of lansoprazole and bismuth subcitrate (LBMT). RESULTS: In the LBMA group, the eradication rate was 74.7% and was significantly related to sex, with no relationship to age. In the LBTA group the eradication rate was 81.5% with similar rates in males and females. No relation to sex or age was observed. In the LBMT group the eradication rate was 82.1% with no difference between women and men and it was not related to age, either. Eradication rates in study groups were similar (P > 0.05). CONCLUSION: A-14-day regimen of lansoprazole, bismuth subcitrate and antibiotic pairs, tetracycline-amoxicillin and tetracycline-metronidazole, is an effective quadruple therapy after one failed course of standard triple therapy. The evaluation of tolerability of and compliance with quadruple therapy needs further studies.