Comparative analysis between a bipolar vessel sealing and cutting device and the tie and suture technique in thyroidectomy: A randomized clinical trial.

BACKGROUND: Advanced bipolar and ultrasonic devices have shown significant reduction in the surgical time of thyroid operations. This randomized, controlled trial assessed if operative time and other relevant outcomes are different for thyroidectomies performed either with a second-generation advanced bipolar device or traditional tie and suture technique. METHODS: Forty-one patients were randomized into 2 groups (advanced bipolar device and traditional tie and suture). Secondary end points included estimated blood loss, postoperative hemorrhage or hematoma requiring operative reintervention, recurrent laryngeal nerve injury, hypoparathyroidism, pain intensity, number of ligatures, analgesia usage, and loss of signal during recurrent laryngeal nerve monitoring. RESULTS: Preoperative characteristics were similar between both groups. Mean operative time in the advanced bipolar device group was reduced by 32.5 minutes compared with the traditional tie and suture group (P = .006). Intraoperative blood loss was similar in both groups. Four patients presented postoperative vocal cord dysmotility, 3 in the traditional tie and suture group and 1 in the advanced bipolar device group (P = ns). Two of these 4 patients also had a >50% amplitude decrease during continuous intraoperative neuromonitoring, 1 in each group. Pain intensity, 12 hours after operation, was significantly greater in the traditional tie and suture group (P = .015), even though pain medication requirements during the initial 24 hours after operation were similar between groups (P = .97). There were no cases of postoperative hemorrhage or hematoma requiring reintervention. Postoperative, symptomatic hypocalcemia occurred in 6 patients, 4 in the traditional tie and suture, and 2 in the advanced bipolar device group. One of them developed permanent hypocalcemia. CONCLUSION: The use of an advanced bipolar device in thyroid operation reduces operative time by >30 minutes, with a similar postoperative outcome profile when compared with the traditional tie and suture technique.

Activational action of testosterone on androgen receptors protects males preventing temporomandibular joint pain.

BACKGROUND: Testosterone protects male rats from Temporomandibular Joint (TMJ) pain. This study investigated whether this protective effect is mediated by an organizational action of testosterone during nervous system development, by central estrogen and androgen receptors and by the 5α-reduced metabolite of testosterone, dihydrotestosterone. METHODS: A pharmacological approach was used to assess the ability of the androgen receptor antagonist flutamide, the estrogen receptor antagonist ICI 182 780 and the 5-α reductase inhibitor dutasteride to block the protective effect of testosterone, evaluated through the behavioral response induced by a TMJ injection of 0.5% formalin. Flutamide and ICI 182 780 were injected into the medullary subarachnoid space, and dutasteride and testosterone were systemically administered. RESULTS: The TMJ injection of 0.5% formalin induced a significant nociceptive behavioral response in gonadectomized male and naïve female, but not in sham gonadectomized male rats, confirming that endogenous testosterone prevents TMJ nociception in males. Testosterone administration prevented formalin-induced TMJ nociception in males gonadectomized either in the neonatal (at the day of birth) or adult period and in naïve female rats, suggesting that the protective effect of testosterone on TMJ nociception does not depend on its organizational actions during critical periods of development. The administration of flutamide and dutasteride but not of ICI 182 780 blocked the protective effect of testosterone. CONCLUSIONS: We conclude that the protective effect of testosterone on TMJ nociception depends on activational actions of dihydrotestosterone on androgen receptors rather than on organizational androgenic actions during central nervous system development or estrogenic actions.

The psoralens adversely affect reproductive function in male wistar rats.

The psoralens occur naturally in produce and are widely used in skin therapy. Studies show that 5-methoxypsoralen and 8-methoxypsoralen reduced birth rates in rats. We determined the effect of psoralens on reproductive function in male rats. Male Wistar rats were dosed daily with 5-methoxypsoralen or 8-methoxypsoralen (75 or 150 mg/kg, p.o.), or vehicle control. Treated males had significantly smaller pituitary glands, fewer sperm per ejaculate, and fewer sperm in the vasa defferentia and epididymides than controls. Dosing significantly elevated levels of testosterone and increased relative testis weight, but did not directly affect testicular weight. Females bred to dosed males required more time to become pregnant, and these males required more breeding attempts. The findings demonstrate the importance of determining the potential risk for infertility and/or birth defects in humans who are exposed to therapeutic, dietary, or occupational psoralens.

Effect of gonadal steroid hormones on formalin-induced temporomandibular joint inflammation.

We have recently demonstrated that gonadal steroid hormones decrease formalin-induced temporomandibular joint nociception in rats. Given that the attenuation of inflammation is a potential mechanism underlying this antinociceptive effect, we evaluated the effect of gonadal steroid hormones on formalin-induced temporomandibular joint inflammation. Plasma extravasation, a major sign of acute inflammation, and neutrophil migration, an important event related to tissue injury, were evaluated. Formalin induced significantly lower temporomandibular joint plasma extravasation and neutrophil migration in proestrus females than in males and in diestrus females. Since estradiol serum level is high in proestrus females and low in diestrus females and in males, these findings suggest that the high physiological level of estradiol decreases temporomandibular joint inflammation. Estradiol but not progesterone administration in ovariectomized females significantly decreased formalin-induced plasma extravasation and neutrophil migration, an effect that was blocked by the estrogen receptor antagonist ICI 182780. Plasma extravasation and neutrophil migration were not affected by orchiectomy, but testosterone or estradiol administration in orchidectomized males significantly decreased them. The androgen receptor antagonist flutamide blocked the anti-inflammatory effect of testosterone while ICI 182780 blocked that of estradiol in males. Previous intravenous administration of a nonspecific selectin inhibitor significantly decreased formalin-induced temporomandibular joint nociception and neutrophil migration in males, revealing a potent and positive correlation between temporomandibular joint nociception and inflammation. Taken together, these findings demonstrate a pronounced anti-inflammatory effect of estradiol and testosterone in the temporomandibular joint region and suggest that this effect may mediate, at least in part, the antinociceptive effect of these hormones.

Peripheral estradiol induces temporomandibular joint antinociception in rats by activating the nitric oxide/cyclic guanosine monophosphate signaling pathway.

Recently, we have reported that high physiological estradiol level during the proestrus phase of the estrous cycle or systemic estradiol administration in ovariectomized rats decreases formalin-induced temporomandibular joint nociception. However, the mechanisms underlying the antinociceptive effect of estradiol are presently unknown. In this study, we used the temporomandibular joint formalin model in rats to investigate whether estradiol decreases nociception by a peripheral non-genomic mechanism, and if so, whether this mechanism is mediated by the activation of the nitric oxide-cyclic guanosine monophosphate signaling pathway and of opioid receptors. The administration of estradiol into the ipsilateral, but not into the contralateral temporomandibular joint significantly reduced formalin-induced temporomandibular joint nociception in ovariectomized and diestrus but not in proestrus females. However, the administration of the estrogen receptor antagonist ICI 182780 into the ipsilateral, but not into the contralateral temporomandibular joint blocked the antinociceptive effect of serum estradiol in proestrus females, suggesting that the physiological effect of estradiol in nociception is mediated, at least in part, by a peripheral mechanism. The administration of estradiol into the ipisilateral temporomandibular joint did not affect formalin-induced nociception in male rats. The antinociceptive effect of temporomandibular joint estradiol administration in ovariectomized and diestrus females was mimicked by estradiol conjugated with bovine serum albumin, which does not diffuse through the plasma membrane, and was blocked by the estrogen receptor antagonist ICI 182780. The administration of the nitric oxide synthase inhibitor (nitro-l-arginine) or of a guanylate cyclase inhibitor (1H-(1,2,4)-oxadiasolo (4,2-a) quinoxalin-1-one) into the ipsilateral, but not into the contralateral temporomandibular joint blocked the antinociceptive effect of estradiol and of estradiol conjugated with bovine serum albumin, while the opioid receptor antagonist naloxone had no effect. These findings suggest that estradiol decreases temporomandibular joint nociception in female rats through a peripheral non-genomic activation of the nitric oxide-cyclic guanosine monophosphate signaling pathway.

Eficacia y seguridad clínica de ebastina contra loratadina en monoterapia o en combinación con fluticasona en pacientes con rinitis alérgica persistente / Efficacy and clinical safety of ebastine versus loratadine in monotherapy or in combination with fluticasone in patients with persistent allergic rhinitis

Fundamento y objetivo. Comparar la eficacia y seguridad de ebastina 20 mg, ebastina 10 mg y loratadina 10 mg en monoterapia o en terapia combinada con fluticasona en el tratamiento de la rinitis persistente. Pacientes y método. Estudio prospectivo, comparativo, al azar, abierto, con grupos paralelos, en 36 pacientes con diagnóstico de rinitis alérgica persistente que fueron asignados primero a tres grupos: ebastina 20 mg (n=12), ebastina 10 mg + pseudoefedrina 120 mg (n=12), y loratadina 10 mg + pseudoefedrina 120 mg; posteriormente se reasignaron a 6 grupos en los que se trataron con ebastina 20 mg, ebastina 10 mg o loratadina 10 mg en monoterapia o terapia combinada con fluticasona nasal. Al término de cada fase se calificaron los síntomas de rinitis, y para evaluar la seguridad se practicaron biometría hemática, pruebas de funcionamiento hepático y ELISA para IL-4, IL-5 e IL-13. Resultados. No se observaron diferencias significativas entre los diferentes grupos de estudio en las pruebas realizadas para evaluar la eficacia y la seguridad de los tratamientos. Se observó al final del estudio una disminución significativa (p=0,003) en los niveles de IL-5 en el lavado nasal de los pacientes de todos los grupos de estudio. Conclusiones. Duplicar la dosis de ebastina a 20 mg fue tan seguro y eficaz como la combinación de la mitad de la dosis de esta (10 mg, con descongestionante nasal). La co-administración con fluticasona no mejoró la eficacia del tratamiento de la rinitis alérgica con antihistamínicos y se sugiere valorar como segunda opción en pacientes con pobre respuesta. Los tratamientos con ebastina 20 mg, ebastina 10 mg y loratadina 10 mg mostraron similar perfil de seguridad y eficacia.(AU)

[Mechanisms of bacterial resistance to heavy metals]. / Mecanismos de resistencia bacteriana a metales pesados.

Resistance to toxic heavy metals has been found in bacteria from clinical and environmental origins. The genetic determinants of resistance are frequently located on plasmids or transposons. Several heavy metal resistance genes have been cloned and sequenced. The mechanisms of resistance to heavy metals are commonly based on novel membrane transport systems that expel the toxic ions (including cobalt, nickel, zinc, and probably copper and chromium) from the bacterial cytoplasm. Arsenic and cadmium ions are effluxed from the cells by specific membrane ATPases encoded by resistance plasmids. Reduction of mercuric ions to the volatile metallic form by a plasmid-coded enzyme is responsible for mercury resistance. Studies on other resistance determinants (e.g., antimony, bismuth, boron, lead, silver, tin, tellurium) have been reported but the mechanisms of resistance are still unknown.

Examination of psoralens-induced photodermatitis in Wistar rats under scanning electron microscopy.

The psoralens are photoactivated plant biosynthetic compounds which are found in several plant families, including common fruits and vegetables. Synthetic forms of the psoralens bergapten (5-methoxypsoralen) and xanthotoxin (8-methoxypsoralen) are extensively used in skin chemotherapy in combination with long-wave ultraviolet radiation (PUVA). Side effects of PUVA therapy are not, however, desirable, and this therapy has been linked with increased incidence of skin cancer in humans. The psoralens are known to be carcinogenic, mutagenic and teratogenic, and to cause photodermatitis. The main objective of this study was to document the effect of PUVA on the epidermis of rats. Female Wistar rats were administered dietary bergapten and/or xanthotoxin (0-200 mg/kg body) and exposed to UVA radiation (45 min./day) for four weeks. At the end of the four-week period the rats were sacrificed; skin samples were taken from the ears and the top part of the tail and fixed for examination by Scanning Electron Microscopy. The animals subjected to PUVA had significantly smaller scales on the tail epidermis (mean scale size for the control 926 mu vs. 725 to 805 mu for the psoralen treatment groups. The rats that received dietary psoralens also had significantly less hair on the ears compared with the control animals (mean number of hairs per millimeter over the ear edge for the control 54.9 vs. 2.00 to 10.7 for the treatment groups). The two compounds were synergistic in their ability to reduce scale size on the tail epidermis.

A novel group of ovarian toxicants: the psoralens.

The psoralens are naturally occurring metabolites found in many crop plants; synthetic forms of 5-methoxypsoralen (bergapten) and 8-methoxypsoralen (xanthotoxin) are widely used in skin photochemotherapy. Our previous research documented that dietary bergapten and xanthotoxin reduced birthrates in female rats when males and females were exposed to these chemicals. The present study was designed to determine the cause of this reduced birthrate and whether this resulted from direct impact on the females. The study demonstrates that bergapten and xanthotoxin administered, either alone or in combination to female rats (mated to undosed males), significantly reduced the number of implantation sites, pups, and corpora lutea in dosed females compared with control animals. Additionally, full uterine weight and empty uterine weight were significantly reduced. These compounds also significantly reduced circulating estrogen levels in a dose-dependent manner. Interestingly, the psoralens significantly induced mRNAs of liver enzymes typically induced by polycyclic aromatic hydrocarbons, CYP1A1 and UGT1A6; the higher the dose, the greater the induction. UGT 2B1 mRNA, typically induced by phenobarbital-like compounds, was not significantly affected. Thus, enhanced oxidative metabolism and conjugation of estrogens in psoralen-treated animals may provide a partial explanation for the effects observed. These findings are also consistent with psoralen-induced reduction in ovarian follicular function and ovulation.