Effects of taurine on contractions of human internal mammary artery: a potassium channel opening action

OBJECTIVE

Taurine is an abundant amino acid that is widely distributed in human and animal tissues. Pharmacodynamic studies show that taurine has hypotensive and myocardial protective effects. Studies in isolated tissue baths show that taurine relaxes precontracted arteries. This study aimed to show the effects of taurine on human internal mammary artery (IMA) in vitro and to explain the mechanisms of its effects.

METHODS

The response in the IMA was recorded isometrically by a force displacement transducer in isolated organ baths. Taurine (20, 40, 80 mM) was added to organ baths after precontraction with KCl (45 mM) or serotonin (5-HT, 30 µM). Taurine-induced relaxations were also tested in the presence of the cyclooxygenase inhibitor indomethacin (10 µM), the nitric oxide synthase inhibitor L-NAME (100 µM), the large conductance Ca2+-activated K+ channel inhibitor tetraethylammonium (TEA, 1 mM), the ATP-sensitive K+ channel inhibitor glibenclamide (GLI, 10 µM), the voltage-sensitive K+ channel inhibitor 4-aminopyridine (4-AP, 1 mM) and the inward rectifier K+ channel inhibitor barium chloride (BaCl2, 30 µM).

RESULTS

Taurine did not affect the resting tone of IMA. However, it produced relaxation in the 5-HT and KCl -precontracted preparations. The relaxation to IMA was not affected by GLI, 4-AP, BaCl2, indomethacin and L-NAME. But, TEA inhibited taurine -induced relaxations significantly (p < 0.05).

CONCLUSIONS

The preincubation of IMA with taurine antagonized KCl and 5-HT induced contractions in a concentration dependent manner, while it did not affect the resting tone. The relaxations to taurine were significantly antagonized by pretreatment with TEA. These results suggest that mechanism of vasodilator effect of taurine in IMA may be the activation of large conductance Ca2+-activated K+ channels.

How do patients with asthma and COPD behave during fasting?

BACKGROUND-OBJECTIVE

Several factors might affect the adherence to treatment in patients with asthma and COPD. Among these factors, the effect of religious beliefs and behaviours has been less studied so far. In this study, the effect of fasting on drug use behaviours of patients with asthma and COPD were comparatively analysed.

METHODS

A total of 150 adult patients with asthma and 150 adult patients with COPD were consecutively enrolled into this cross-sectional study. The patients were asked whether they fast during Ramadan and if the answer was yes, they were kindly asked to respond to further questions related to use of inhaled medications during that particular time.

RESULTS

The majority of the cases from both groups [98 (65.3%) of asthma patients and 139 (92.6%) of COPD] were fasting during Ramadan. The majority of the patients with COPD (n=126; 90.6%) reported that they quitted their regular therapy basis during Ramadan. On the other hand, the majority of asthma patients used their controller inhaled medications during Ramadan and preferred to use them on iftar and sahur times (n=81, 82.6%).

CONCLUSION

Our results showed that in a Muslim population, the patients with asthma and COPD do not feel their diseases to be an inhibitory factor for fasting during Ramadan. However, fasting seems to be an important determining factor in medication compliance by modifying the drug use behaviours in each group in a different way. Therefore, the patients should be informed about the effects of fasting on their disease and the allowed drugs during fasting.

Total monoamine oxidase (MAO) inhibition by chestnut honey, pollen and propolis

Monoamine oxidase (MAO) inhibitors are generally used in the treatment of depressive disorders and some neurodegenerative illnesses, such as Parkinson's disease and Alzheimer's disease. The aim of this preliminary study was to investigate the MAO [MAO (E.C.1.4.3.4)] inhibiting effect of various apitherapeutic products, such as chestnut honey, pollen and propolis. Extracts' MAO inhibition was measured using peroxidase-linked spectrophotometric assay in enzyme isolated from rat liver microsomes, and the values are expressed as the inhibition concentration (IC50) causing 50% inhibition of MAO. The antioxidant activity of the bee products was also determined in terms of total phenolic content (TPC) and ferric reducing/antioxidant power in aquatic extracts. All samples exhibited substantial inhibition of MAO, propolis having the highest. Inhibition was related to samples' TPCs and antioxidant capacities. These results show that bee products possess a sedative effect and may be effective in protecting humans against depression and similar diseases.

Preoperative chemoradiotherapy improves local recurrence free survival in locally advanced rectal cancer

PURPOSE

Preoperative chemoradiotherapy (pre-CRT) followed by total mesorectal excision (TME) is the recommended therapy for patients with locally advanced rectal cancer (LARC). The primary aim of this study was to compare the rates of local and distant recurrence and overall survival (OS) in LARC patients who received pre-CRT vs postoperative (post) CRT.

METHODS

The medical records of 158 rectal cancer patients with clinical stage T3, T4 or N positive disease who received either pre-CRT or post-CRT between 2000-2009 were retrospectively analysed. Pre-CRT employed protracted 5-fluorouracil (5FU) infusion, whereas post-CRT included bolus 5FU and leucovorin concurrently with radiation therapy (RT). Radiation dose was 50.4 Gy in 82% and 45 Gy in 18% of the patients.

RESULTS

158 patients (65 females, 93 males) were analysed. Median age was 56.5 years (range 19-78). Fifty-three (34%) patients received pre-CRT and 105 (66%) post-CRT. Median follow-up was 43.3 months (range 8-182) and 47.6 months (range 9-194) in pre-CRT and post-CRT patients, respectively. After pre-CRT, significant downstaging was achieved. However, the type of surgical resection was not influenced by the administration of pre-CRT in tumors ≥5 cm distant from the anal verge (p=0.3). Pathologic complete response was achieved in 20% of the patients in the pre-CRT group. Local recurrence free survival (LRFS) at 5-years was 89.2% in the pre-CRT and 74.8% in the post-CRT group (p=0.04). Distant recurrence free survival (DRFS) at 5-years was 81.7% and 68.5 % in pre-CRT and post-CRT groups, respectively (p=0.1). OS was similar in the two groups (71.4 vs 64.4%, p=0.9).

CONCLUSION

Treatment of LARC with pre-CRT followed by surgery improved LRFS as compared to surgery followed by post-CRT, but failed to improve DRFS or OS in our patient population.

Cerebellar mutism syndrome and its relation to cerebellar cognitive and affective function: Review of the literature

Tumors of the cerebellum and brainstem account for half of all brain tumors in children. The realization that cerebellar lesions produce clinically relevant intellectual disability makes it important to determine whether neuropsychological abnormalities occur in long-term survivors of pediatric cerebellar tumors. Little is known about the neurobehavioral sequale resulting specifically from the resection of these tumors in this population. We therefore reviewed neuropsychological findings associated with postoperative cerebellar mutism syndrome and discuss the further implications for cerebellar cognitive function.

Atomoxetine and methylphenidate treatment in children with ADHD: the efficacy, tolerability and effects on executive functions

The aim of this study was to compare the safety, efficacy, tolerability, and the effects of atomoxetine and OROS-MPH on executive functions in children with ADHD. This study was an open-label study that only included two medication groups. Children were randomized to open-label atomoxetine or OROS-MPH for 12 weeks. Primary efficacy measures were T-DSM-IV-S, CGI-I and neuropsychological tests battery. Safety assessments included electrocardiogram, adverse events checklist and laboratory tests. According to the endpoint improvement scores of CGI and parents T-DSM-IV-S, treatment responses were not significantly different between the two study groups. OROS-MPH led to a significantly greater reduction in teacher T-DSM-IV-S scale scores. OROS-MPH was more effective than atomoxetine on Stroop-5 time and number of corrections. Significant decrease in the percentage of perseverative errors on WCST in the OROS-MPH group was seen (p = 0.005). The most frequently reported adverse events in the atomoxetine group were anorexia, nausea, nervousness, weight loss, abdominal pain, and somnolence. In the OROS-MPH group, patients most frequently reported anorexia, nervousness, insomnia, headache, nausea, and weight loss. When all these results are considered, although both drugs can be considered effective in ADHD treatment, more remarkable improvement is provided by OROS-MPH based on the rates across informant (i.e., teachers, clinicians) and neuropsychological evaluation.

Natural selection and functional genetic variation in the p53 pathway

The allele frequencies of two functional single-nucleotide polymorphisms (SNPs) in the p53 pathway, the MDM2 SNP309 and TP53 Arg72Pro, vary dramatically among populations. That the frequencies of the TP53 SNP follow a clinal distribution may suggest that selective pressure from environmental variables correlated with latitude contributed to these observed population differences. Recently, winter temperature and UV radiation were found to be significantly correlated with the TP53 and the MDM2 SNPs, respectively, in East Asians; whether these correlations are more extreme than expected based upon nonselective factors such as patterns of human migration remains unclear. Here, we genotyped these two SNPs in 971 unrelated individuals from 52 unique populations worldwide and tested for correlations with both latitude and a number of climate-related environmental variables on a global scale, controlling for these neutral processes. The TP53 SNP was associated with a significant selection signal for a few climate variables, such as short-wave radiation flux in the winter, but these signals were no longer significant after correction for multiple tests. The MDM2 SNP did not exhibit a significant signal with any climate variable. Therefore, these SNPs are unlikely to be under selective pressure driven by these variables. Thus, these data underscore the need to incorporate population history when assessing signatures of selection.

Social anxiety level in Turkish adolescents

Social phobia is a mental disorder characterized by extreme and consistent fear of meeting new people, scrutiny in a variety of performance and/or interactional situations. The aim of this study was to investigate the level of self-reported social anxiety in a community sample of Turkish adolescents and the relationship between social anxiety and some sociodemographic parameters. This study was a school-based cross-sectional study. Students in grades 6-8 (aged 10-16) from 12 schools in Kocaeli/Turkey were screened by the Social Anxiety Scale for Adolescents (SAS-A). The correlations of sociodemographic parameters with the SAS-A scores were examined. Data from a sample of 1,713 students (865 boys 50.4% and 848 girls 49.5%) were analyzed. A significant gender difference in the SAS-A points was found. Boys reported higher SAS-A total and subscale scores (except social avoidance and distress-general subscale score) than did girls. A significant negative correlation was found between socioeconomic status and social anxiety level. SAS-A scores were higher in those with a low socioeconomic level, and who were going to rural schools. The result of this study showed that social phobic symptoms among Turkish adolescents were more severe in boys. Some factors such as low socioeconomic level, and going to a rural school had impact on the SAS-A scores. As the impairment in the school-domain was reported to be quite high, professionals and teachers need to recognize social anxiety in adolescents, so that help can be offered to overcome the difficulties social phobia causes.

Priapism associated with methylphenidate: a case report

Priapism is a persistent unwanted erection that is not associated with sexual desire or sexual stimulation. Immediate diagnosis and treatment are essential for priapism; otherwise, it causes ischemia of cavernous tissues, which will result in erectile dysfunction. In this paper, we report a 14-year-old male patient who presented with priapism after administration of immediate-release methylphenidate. When the usage of immediate-release methylphenidate was terminated, priapism spontaneously disappeared. To our knowledge, this is the first report in the literature of priapism associated with immediate-release methylphenidate use. This issue is significant because in the case of immediate-release methylphenidate prescription to adolescent male patients, the probability of the development of priapism should not be ignored.

A multi-center, open label, crossover designed prospective study evaluating the effects of lipid lowering treatment on steroid synthesis in patients with Type 2 diabetes (MODEST Study)

OBJECTIVE

It has been suggested that lipid-lowering treatment with the use of statins adversely affects the steroid hormones. However, the safety of lipid lowering treatment targeting very low levels of LDL with respect to the steroid hormones has not been established.

RESEARCH DESIGN AND METHODS

A prospective, randomized, multicenter trial was conducted involving 98 patients. The patients were randomized into 2 groups: group-I received 10 mg of atorvastatin plus 10 mg of ezetimibe and group-II 80 mg of atorvastatin for the first 3 months. After crossover, the first group received 80 mg of atorvastatin and the second group 10 mg of atorvastatin plus 10 mg of ezetimibe for the following 3 months. Cortisol, DHEAS, testosterone, and estradiol levels were measured at the enrollment and at the end of the 1st, 2nd, 3rd, and 6th months.

RESULTS

Along with a decrease in LDL level, the levels of DHEAS, testosterone, and estradiol decreased in both groups (p<0.001). While cortisol levels were maintained in the group given 10 mg of atorvastatin plus 10 mg of ezetimibe, it decreased significantly after the crossover to 80 mg of atorvastatin (p<0.001). The group initially given 80 mg of atorvastatin measured a lower level of cortisol for the first 3 months and it returned to normal levels after switching to 10 mg of atorvastatin plus 10 mg of ezetimibe.

CONCLUSION

Eighty milligrams of atorvastatin decreased all adrenal and gonadal steroids, whereas 10 mg of ezetimibe combined with 10 mg of atorvastatin had at least no impact on cortisol levels.

Effects of depression and anxiety on quality of life of patients with rheumatoid arthritis, knee osteoarthritis and fibromyalgia syndrome

OBJECTIVE

To measure the effects of depression and anxiety on quality of life (QoL) in patients with rheumatoid arthritis (RA), knee osteoarthritis (OA) and fibromyalgia syndrome (FMS).

METHODS

One hundred and fifty-four patients with RA, knee OA, and FMS who presented to the physical medicine and rehabilitation department were studied. For evaluation of the patients, Beck depression scale, Beck anxiety scale, and Short Form-36 were used.

RESULTS

Twenty-two per cent of patients (n = 34) were diagnosed with of RA, 52.6% (n = 81) knee OA and 25.3% (n = 39) FMS. Except for the subscales, of physical and emotional role, there were statistically significant differences among diagnostic groups in the rest of the SF-36 subscales. In the physical functioning subscale, the highest score was obtained in the fibromyalgia group and the lowest in the RA group (p < 0.001). However, in the bodily pain subscale, the lowest score was recorded in the fibromyalgia group (p = 0.019). In all diagnostic groups, the scores of SF-36 subscales were significantly low in patients who scored above the threshold value of Beck depression scale (p < 0. 001). A strong negative correlation was detected between scores of Beck anxiety scale and the scores of all SF36 subscales in patients with RA and knee OA. On the other hand, in patients with FMS, anxiety scores correlated negatively with only physical and somatic function scores of SF-36.

CONCLUSION

Quality of life is significantly low in patients with RA, knee OA and FMS, whose depression and/or anxiety scores are high. Therefore, these patients should be managed using a multidisciplinary approach including psychiatric support.

Vasodilating Mechanisms of Testosterone

The increased incidence of cardiovascular disease in man compared with premenopausal women suggests an unfavourable effect of male sex hormone testosterone on the cardiovascular system. However, numerous clinical and epidemiological studies reported a controversial relationship between testosterone and cardiovascular disease. Furthermore, an increasing amount of evidence indicate that testosterone can exert acute vasorelaxing effects, VIA non-genomic mechanisms. These effects involve primarily the vascular smooth muscle, without requiring the presence of endothelium, although an endothelial contribution is apparent in some studies. To date, the mechanism behind the vasodilatory action of testosterone is still under debate and might be through either activation of K (+) channels or blockade of Ca (2+) channels in vascular muscle cells. The purpose of this article is to review the evidence regarding the vasodilating effect of testosterone as well as its mechanism of action.

Metastatic primitive neuroectodermal tumor of the ovary in pregnancy

Primitive neuroectodermal tumor (PNET) is a small round tumor belonging to the PNET/Ewing's sarcoma family. We hereby report a case of PNET of the ovary, which was detected at the second trimester of pregnancy. Chemotherapy was administered and a healthy baby was delivered by cesarean section. After the pregnancy, the mother was found to have metastatic disease. Chemotherapy was continued, but she died due to progressive disease 13 months after the initial diagnosis. In this case report, we discuss chemotherapy options during pregnancy and the importance of multidisciplinary approach to unusual presentations of rare tumors

Leptin, soluble interleukin-6 receptor, C-reactive protein and soluble vascular cell adhesion molecule-1 levels in human coronary atherosclerotic plaque

The aim of the present study was to explore the relationship between tissue levels of leptin, soluble interleukin-6 receptor (sIL-6R), high-sensitive-C-reactive protein (hs-CRP) and soluble vascular cell adhesion molecule-1 (sVCAM-1) in atherosclerotic plaques, and traditional risk factors. Coronary artery specimens were obtained from 35 consecutive patients (26 men and nine women) who underwent coronary artery bypass grafting procedure. The mean tissue levels of leptin, hs-CRP and sIL-6R were significantly higher in patients with diabetes mellitus than without diabetes mellitus. When patients were classified according to the smoking status, the mean tissue levels of leptin, hs-CRP and sIL-6R were significantly higher in current smokers than both former smokers and non-smokers. In addition, the mean tissue levels of leptin and sIL-6R were significantly higher in former smokers than non-smokers. There was a positive association between leptin and hs-CRP, sIL-6R and plasma glucose in all patients. Plasma HDL levels were associated negatively with atherosclerotic tissue levels of leptin. Tissue levels of sIL-6R were associated significantly in a positive manner with leptin, hs-CRP and plasma glucose, while tissue levels of hs-CRP were associated with both leptin and sIL-6R. In conclusion, it is attractive to speculate that hs-CRP, sIL-6R and leptin could act synergistically in course of local inflammatory activity and those molecules may not be just markers of inflammation and cardiovascular risk but are also likely to play a pathogenic role in atheromatous plaque. In addition, atherosclerotic tissue levels of CRP, sIL-6R and leptin were significantly higher in current smokers and patients with diabetes.