Management of Neuropathic Chronic Pain with Methadone Combined with Ketamine: A Randomized, Double Blind, Active-Controlled Clinical Trial.

BACKGROUND: Methadone and ketamine are used in neuropathic pain management. However, the benefits of both drugs association are uncertain in the treatment of neuropathic pain. OBJECTIVE: Our primary objective was test the hypothesis that oral methadone combined with oral ketamine is more effective than oral methadone or ketamine alone in reducing neuropathic pain. STUDY DESIGN: We conducted a randomized, double blind, active-controlled parallel-group clinical trial. METHODS: Forty-two patients with neuropathic pain refractory to conventional therapy were randomly assigned to receive oral methadone (n = 14), ketamine (n = 14), or methadone plus ketamine (n = 14) over a 3-month period. RESULTS: During these 90 days, we observed pain scores using a visual analogical scale (VAS), allodynia, burning/shooting pain, and some side effects. All treatments were effective in reducing pain scores by at least 40%. However, a significant improvement in pain was observed only in the ketamine alone group compared with both the methadone or methadone/ketamine groups. No significant differences were observed among the treatment groups for the reduction of burning or shooting pain, while ketamine alone was more effective than methadone or methadone/ketamine for the reduction of allodynia. LIMITATIONS: Formal assessment for awareness of the allocation was not performed, some co-intervention bias may have occurred, our results could be only relevant to the patient population investigated and the use of VAS as the primary outcome detect changes in pain intensity but not to assess neuropathic pain symptoms. CONCLUSION: This study indicates that ketamine was better than methadone or methadone/ketamine for treating neuropathic pain.Key words: Multimodal analgesia, refractory pain, NMDA receptor, opioid.

Glyphosate applied at low doses can stimulate plant growth.

BACKGROUND: Glyphosate blocks the shikimic acid pathway, inhibiting the production of aromatic amino acids and several secondary compounds derived from these amino acids. Non-target plants can be exposed to low doses of glyphosate by herbicide drift of spray droplets and contact with treated weeds. Previous studies have reported that low doses of glyphosate stimulate growth, although these data are very limited. The objective of this study was to determine the effects of low glyphosate doses on growth of a range of plant species. RESULTS: Growth of maize, conventional soybean, Eucalyptus grandis Hill ex Maiden, Pinus caribea L. and Commelia benghalensis L. was enhanced by 1.8-36 g glyphosate ha(-1). Growth of glyphosate-resistant soybean was unaffected by any glyphosate dose from 1.8 to 720 g AE ha(-1). The optimum doses for growth stimulation were distinct for plant species and tissue evaluated. The greatest stimulation of growth was observed for C. benghalensis and P. caribea. Shikimic acid levels in tissues of glyphosate-treated soybean and maize were measured and found to be elevated at growth-stimulating doses. CONCLUSION: Subtoxic doses of glyphosate stimulate the growth of a range of plant species, as measured in several plant organs. This hormesis effect is likely to be related to the molecular target of glyphosate, since the effect was not seen in glyphosate-resistant plants, and shikimate levels were enhanced in plants with stimulated growth.

Gut structure of two species of the neotropical genus Tauritermes Krishna (Isoptera: Kalotermitidae) / Estructura del tubo digestivo de dos especies del género neotropical Tauritermes Krishna (Isoptera: Kalotermitidae)

Gut morphology of two species of the neotropical genus Tauritermes Krishna was analyzed. Detailed description of the coiling gut and the cuticular armature of the gizzard and first and second proctodeal segments of pseudergates are given. The characteristics of Tauritermes gut followed the pattern previously known for the family, but some differences among this genus and other Kalotermitidae genera were: the length of the midgut, the structure and cuticular ornamentation of the first and second proctodeal segments, the junction of the third and fourth proctodeal segments and the armature of the rectal valve. Tauritermes was differentiated from other Kalotermitidae genera by means of the gut characters, currently used in termite systematics and phylogeny

En este trabajo se analizó la anatomía del tubo digestivo de dos especies del género neotropical Tauritermes Krishna. Se presentan descripciones detalladas del enrollamiento del tubo digestivo y de la armadura cuticular de la molleja y del primer y segundo segmento proctodeal de pseudoergates. Aunque las principales características observadas en Tauritermes se incluyen en el patrón previamente conocido para la familia, fueron establecidas varias diferencias entre este género y otros de Kalotermitidae, principalmente con respecto a la longitud del mesenterón, la estructura y ornamentación cuticular del primer y segundo segmento proctodeal, la unión del tercer y cuarto segmento proctodeal y la armadura de la válvula rectal. Los caracteres del intestino, actualmente usados en sistemática y filogenia de termites, permiten diferenciar a Tauritermes de otros géneros de Kalotermitidae