Transcutaneous electrical nerve stimulation and conditioned pain modulation influence the perception of pain in humans.

BACKGROUND: Research in animal models suggests that transcutaneous electrical nerve stimulation (TENS) and conditioned pain modulation (CPM) produce analgesia via two different supraspinal pathways. No known studies have examined whether TENS and CPM applied simultaneously in human subjects will enhance the analgesic effect of either treatment alone. The purpose of the current study was to investigate whether the simultaneous application of TENS and CPM will enhance the analgesic effect of that produced by either treatment alone. METHODS: Sixty healthy adults were randomly allocated into two groups: (1) CPM plus active TENS; (2) CPM plus placebo TENS. Pain threshold for heat (HPT) and pressure (PPT) were recorded from subject's left forearm at baseline, during CPM, during active or placebo TENS, and during CPM plus active or placebo TENS. CPM was induced by placing the subjects' contralateral arm in a hot water bath (46.5 °C) for 2 min. TENS (100 µs, 100 Hz) was applied to the forearm for 20 min at a strong but comfortable intensity. RESULTS: Active TENS alone increased PPT (but not HPT) more than placebo TENS alone (p = 0.011). Combining CPM and active TENS did not significantly increase PPT (p = 0.232) or HPT (p = 0.423) beyond CPM plus placebo TENS. There was a significant positive association between PPT during CPM and during active TENS (r(2) = 0.46; p = 0.003). CONCLUSIONS: TENS application increases PPT; however, combining CPM and TENS does not increase the CPM's hypoalgesic response. CPM effect on PPT is associated with the effects of TENS on PPT.

Protective mechanism of agmatine pretreatment on RGC-5 cells injured by oxidative stress.

Agmatine has neuroprotective effects on retinal ganglion cells (RGCs) as well as cortical and spinal neurons. It protects RGCs from oxidative stress even when it is not present at the time of injury. As agmatine has high affinity for various cellular receptors, we assessed protective mechanisms of agmatine using transformed RGCs (RGC-5 cell line). Differentiated RGC-5 cells were pretreated with 100 muM agmatine and consecutively exposed to 1.0 mM hydrogen peroxide (H2O2). Cell viability was determined by measuring lactate dehydrogenase (LDH), and the effects of selective alpha 2-adrenergic receptor antagonist yohimbine (0-500 nM) and N-methyl-D-aspartic acid (NMDA) receptor agonist NMDA (0-100 microM) were evaluated. Agmatine's protective effect was compared to a selective NMDA receptor antagonist MK-801. After a 16-h exposure to H2O2, the LDH assay showed cell loss greater than 50%, which was reduced to about 30% when agmatine was pretreated before injury. Yohimbine almost completely inhibited agmatine's protective effect, but NMDA did not. In addition, MK-801 (0-100 microM) did not significantly attenuate the H2O2-induced cytotoxicity. Our results suggest that neuroprotective effects of agmatine on RGCs under oxidative stress may be mainly attributed to the alpha 2-adrenergic receptor signaling pathway.

Protective mechanism of agmatine pretreatment on RGC-5 cells injured by oxidative stress

Agmatine has neuroprotective effects on retinal ganglion cells (RGCs) as well as cortical and spinal neurons. It protects RGCs from oxidative stress even when it is not present at the time of injury. As agmatine has high affinity for various cellular receptors, we assessed protective mechanisms of agmatine using transformed RGCs (RGC-5 cell line). Differentiated RGC-5 cells were pretreated with 100 ìM agmatine and consecutively exposed to 1.0 mM hydrogen peroxide (H2O2). Cell viability was determined by measuring lactate dehydrogenase (LDH), and the effects of selective alpha 2-adrenergic receptor antagonist yohimbine (0-500 nM) and N-methyl-D-aspartic acid (NMDA) receptor agonist NMDA (0-100 µM) were evaluated. Agmatine’s protective effect was compared to a selective NMDA receptor antagonist MK-801. After a 16-h exposure to H2O2, the LDH assay showed cell loss greater than 50 percent, which was reduced to about 30 percent when agmatine was pretreated before injury. Yohimbine almost completely inhibited agmatine’s protective effect, but NMDA did not. In addition, MK-801 (0-100 µM) did not significantly attenuate the H2O2-induced cytotoxicity. Our results suggest that neuroprotective effects of agmatine on RGCs under oxidative stress may be mainly attributed to the alpha 2-adrenergic receptor signaling pathway.

Self report ratings of psychopathology in Korean and Jamaican women

Women from different nations with different customs may express varying levels of psychological distress and present problems in forms their societies accept. We compared women from Korea and Jamaica where women's roles and behaviour differ, and may influence the types of symptoms they display. Korean culture supports women's dependence, submissiveness, and obedience toward male partners and discourages women from expressing feelings, a custom that causes women distress which is usually expressed as anxiety related disorders. Jamaican women comprise most Jamaica's work force and are described as independent, outwardly expressive, and unlike Korean women may externalize their psychological distress. We tested these hypotheses using the Brief Symptom Inventory (BSI), a multidimensional psychopathology measure, to survey Korean (N = 214) and Jamaican women (N = 282). Using age and nationality as predictors and total score and the nine BSI scales as criterion variables considered separately, multiple regression analyses reveal significantly higher scores on total problems and on all the paranoid scales scores on total problems and on all the paranoid scale scores for Korean than for Jamaica women. Large effect on the Somatization and Obsessive Complusive scales and a medium effect on the anxiety scale indicate that while Korean women generally expressed much more distress than Jamaica women, they are particularly vulnerable for the development of anxiety related problems(AU)

Identification of emotions and emotional confusion in Jamaican men vs women: do they predict severity and types of psychopathology?

In Jamaica, women comprise two-thirds of the workforce, but the society rigidly defines gender roles and behaviour for men versus women. Jamaican women are reportedly independent and outwardly express wide varieties of feelings. Jamaican men have greater difficulty acknowledging, labelling and expressing their emotions, a process labelled alexithymia. Therefore, Jamaican men may report higher levels of alexithymia. Since identification and expression of feelings are positively associated with psychological health, Jamaicans (especially men) with higher alexithymia scores should report higher levels of psychological distress than those with low alexithymia scores. These hypotheses were tested using the Toronto Alexithymia Scale II (TAS-II), and Brief Symptom Inventory (BSI), to survey 400 Jamaican men and women

Phase II study of neoadjuvant concurrent biochemotherapy in melanoma patients with local-regional metastases.

Our results with concurrent biochemotherapy in patients with stage IV melanoma have been encouraging. Based on these data, we conducted a phase II study to determine the clinical and histological response rate to neoadjuvant concurrent biochemotherapy in patients with local-regional metastases of cutaneous melanoma (stage III). A total of 65 patients with biopsy-proven, measurable and potentially resectable local-regional disease (nodal, satellite/in-transit metastases and/or local recurrence) were treated with cisplatin 20 mg/m2 intravenously (i.v.) on days 1 to 4, vinblastine 1.5 mg/m2 i.v. on days 1 to 4, dacarbazine 800 mg/m2 i.v. on day 1 only, interleukin-2 9 MIU/m2 per day i.v. by 96 h continuous infusion on days 1 to 4, and interferon-alpha 2a 5 MU/m2 subcutaneously on days 1 to 5, repeated every 3 weeks. Patients underwent surgery after two to four courses of biochemotherapy. Those with tumour regression after two preoperative courses received two additional postoperative courses. Of the 64 patients assessable for clinical response, 28 (44%) had a partial response. Of the 62 patients whose response was assessed histologically, four (6.5%) had no evidence of viable tumour in the surgical specimen (pathological complete remission, pCR) and 27 (43.5%) had a partial response, giving an overall response rate of 50%. Tumour burden did not correlate with response, although patients who achieved a pCR had a significantly lower tumour burden (P = 0.02). Our phase II study indicates that neoadjuvant biochemotherapy is an active treatment for melanoma patients with local-regional metastases. However, it is unclear if biochemotherapy is more active than chemotherapy alone; phase III randomized trials are ongoing to answer this question in patients with stage IV disease.