[Percutaneous versus open technique transpedicular fixation in patients with thoracolumbares type A fractures]. / Fijación transpedicular percutánea versus técnica abierta en pacientes con fracturas toracolumbares tipo A.

INTRODUCTION: Percutaneous transpedicular fixation techniques are an emerging tool in the treatment of spinal trauma, however, their use is not fully accepted. OBJECTIVE: Compare results in patients with traumatic vertebral fracture, treated with percutaneous transpedicular fixation surgery versus open transpedicular fixation. MATERIAL AND METHODS: From January to December 2016, 15 patients with traumatic vertebral fracture were randomly divided into 2 groups, group A were six treated with percutaneous transpedicular fixation, group B were treated with open technique transpedicular fixation, three patients were eliminated. Transoperative bleeding, postoperative pain with the 24-hour and two-week postoperative visual scale, the six-week Oswestry lumbar pain disability index, and three, six, 12 and 24 months of postoperative control were evaluated. RESULTS: The follow-up was 24 months. Statistically significant differences in transoperative bleeding (p 2.43E-05), EVA on the first day (p 0.0003), EVA at two weeks (p = 0.01) were reported in the Oswestry lumbar pain disability questionnaire at six weeks (p = 0.0007), three months (p = 0.005), six months (p = 0.005), 12 months (p = 0.01) and 24 months (p = 0.004), no significant differences were observed with respect to operating time (p = 0.12). DISCUSSION: In our work we find that transoperative bleeding, postoperative pain and functional disability are significantly minor in the percutaneous transpedicular fixation group.

INTRODUCCIÓN: Las técnicas de fijación transpedicular percutánea son una herramienta emergente en el tratamiento del trauma espinal, sin embargo, su uso no es totalmente aceptado. OBJETIVO: Comparar resultados en pacientes con fractura vertebral traumática que fueron tratados con cirugía de fijación transpedicular percutánea versus fijación transpedicular abierta. MATERIAL Y MÉTODOS: De Enero a Diciembre de 2016, 15 pacientes con fractura vertebral traumática fueron divididos aleatoriamente en dos grupos: el grupo A fue de seis pacientes tratados con fijación transpedicular percutánea y el grupo B fue de seis pacientes tratados con fijación transpedicular con técnica abierta; tres pacientes fueron eliminados. Se evaluó el sangrado transoperatorio, el dolor postoperatorio con la escala visual análoga a las 24 horas y a las dos semanas del postoperatorio; también se evaluó el índice de discapacidad de dolor lumbar Oswestry a seis semanas, además de tres, seis, 12 y 24 meses del postoperatorio. RESULTADO: El seguimiento fue de 24 meses. Se reportaron diferencias estadísticamente significativas en el sangrado transoperatorio (p 2.43E-05), EVA al primer día (p 0.0003), EVA a las dos semanas (p = 0.01); también en el cuestionario de discapacidad de dolor lumbar Oswestry a las seis semanas (p = 0.0007), tres meses (p = 0.005), seis meses (p = 0.005), 12 meses (p = 0.01) y 24 meses (p = 0.004). No se observaron diferencias significativas con respecto al tiempo operatorio (p = 0.12). DISCUSIÓN: En nuestro trabajo encontramos que el sangrado transoperatorio, dolor postoperatorio y discapacidad funcional son significativamente menores en el grupo de fijación transpedicular percutánea.

Preclinical evaluation of the effects on the gastrointestinal tract of the antineoplastic drug vincristine repeatedly administered to rats.

BACKGROUND: Vincristine is a commonly used chemotherapeutic agent. It is associated with undesirable digestive side effects. However, the impact of vincristine on gastrointestinal structure and motility or its long-term effects have not been deeply studied in animal models. This could be useful in order to develop therapeutic or preventive strategies for cancer patients. The aim of this study was to analyze such effects. METHODS: Rats received saline or vincristine (0.1 mg kg-1 , ip) daily for 10 days. Evaluations were performed during treatment and 2-6 weeks after. Somatic mechano-sensitivity was assessed using von Frey hairs. Gastrointestinal motor function was studied by means of radiographic still images and colonic propulsion of fecal pellets using fluoroscopy videos. Histological assessment of the gut morphology and immunohistochemistry for HuC/D and nNOS were performed in whole-mount myenteric plexus preparations. KEY RESULTS: Peripheral sensitivity was increased in animals treated with vincristine and did not subside 2 weeks after treatment finalization. Vincristine treatment inhibited gastrointestinal motility although this was recovered to normal values with time. Damage in the digestive wall after vincristine treatment was greater in the ileum than in the colon. Villi shortening (in ileum) and large inflammatory nodules still remained 2 weeks after treatment finalization. Finally, the proportion of nNOS-immunoreactive neurons was increased with vincristine and continued to be increased 2 weeks after treatment finalization. CONCLUSIONS AND INFERENCES: Vincristine alters gastrointestinal motility, peripheral sensitivity and mucosal architecture. Vincristine-induced neuropathy (somatic and enteric), intestinal mucosa damage and inflammatory infiltrations are relatively long-lasting.

May cannabinoids prevent the development of chemotherapy-induced diarrhea and intestinal mucositis? Experimental study in the rat.

BACKGROUND: The antineoplastic drug 5-fluoruracil (5-FU) is a pirimidine analog, which frequently induces potentially fatal diarrhea and mucositis. Cannabinoids reduce gastrointestinal motility and secretion and might prevent 5-FU-induced gut adverse effects. Here, we asked whether cannabinoids may prevent diarrhea and mucositis induced by 5-FU in the rat. METHODS: Male Wistar rats received vehicle or the non-selective cannabinoid agonist WIN 55,212-2 (WIN; 0.5 mg kg-1 injection-1 , 1 injection day-1 , 4 consecutive days) by intraperitoneal (ip) route; on the first 2 days, animals received also saline or 5-FU (150 mg kg-1 injection-1 , cumulative dose of 300 mg kg-1 ). Gastrointestinal motor function was radiographically studied after barium contrast intragastric administration on experimental days 1 and 4. Structural alterations of the stomach, small intestine and colon were histologically studied on day 4. PAS staining and immunohistochemistry for Ki67, chromogranin A and CD163 were used to detect secretory, proliferating, and endocrine cells, and activated macrophages respectively. KEY RESULTS: As shown radiographically, 5-FU induced significant gastric emptying delay (on days 1 and 4) and diarrhea (on day 4). WIN did not significantly alter the motility curves obtained for either control or 5-FU-treated animals but tended to reduce the severity of 5-FU-induced diarrhea and increased permanence of barium from day 1 to the beginning of day 4 in 5-FU-treated animals. 5-FU-induced mucositis was severe and not counteracted by WIN. CONCLUSIONS AND INFERENCES: 5-FU-induced diarrhea, but not mucositis, was partly prevented by WIN at a low dose. Cannabinoids might be useful to prevent chemotherapy-induced diarrhea.

Computer vision-based diameter maps to study fluoroscopic recordings of small intestinal motility from conscious experimental animals.

BACKGROUND: When available, fluoroscopic recordings are a relatively cheap, non-invasive and technically straightforward way to study gastrointestinal motility. Spatiotemporal maps have been used to characterize motility of intestinal preparations in vitro, or in anesthetized animals in vivo. Here, a new automated computer-based method was used to construct spatiotemporal motility maps from fluoroscopic recordings obtained in conscious rats. METHODS: Conscious, non-fasted, adult, male Wistar rats (n=8) received intragastric administration of barium contrast, and 1-2 hours later, when several loops of the small intestine were well-defined, a 2 minutes-fluoroscopic recording was obtained. Spatiotemporal diameter maps (Dmaps) were automatically calculated from the recordings. Three recordings were also manually analyzed for comparison. Frequency analysis was performed in order to calculate relevant motility parameters. KEY RESULTS: In each conscious rat, a stable recording (17-20 seconds) was analyzed. The Dmaps manually and automatically obtained from the same recording were comparable, but the automated process was faster and provided higher resolution. Two frequencies of motor activity dominated; lower frequency contractions (15.2±0.9 cpm) had an amplitude approximately five times greater than higher frequency events (32.8±0.7 cpm). CONCLUSIONS & INFERENCES: The automated method developed here needed little investigator input, provided high-resolution results with short computing times, and automatically compensated for breathing and other small movements, allowing recordings to be made without anesthesia. Although slow and/or infrequent events could not be detected in the short recording periods analyzed to date (17-20 seconds), this novel system enhances the analysis of in vivo motility in conscious animals.

In vitro and non-invasive in vivo effects of the cannabinoid-1 receptor agonist AM841 on gastrointestinal motor function in the rat.

BACKGROUND: Cannabinoids have been traditionally used for the treatment of gastrointestinal (GI) symptoms, but the associated central effects, through cannabinoid-1 receptors (CB1R), constitute an important drawback. Our aims were to characterize the effects of the recently developed highly potent long-acting megagonist AM841 on GI motor function and to determine its central effects in rats. METHODS: Male Wistar rats were used for in vitro and in vivo studies. The effect of AM841 was tested on electrically induced twitch contractions of GI preparations (in vitro) and on GI motility measured radiographically after contrast administration (in vivo). Central effects of AM841 were evaluated using the cannabinoid tetrad. The non-selective cannabinoid agonist WIN 55,212-2 (WIN) was used for comparison. The CB1R (AM251) and CB2R (AM630) antagonists were used to characterize cannabinoid receptor-mediated effects of AM841. KEY RESULTS: AM841 dose-dependently reduced in vitro contractile activity of rat GI preparations via CB1R, but not CB2R or opioid receptors. In vivo, AM841 acutely and potently reduced gastric emptying and intestinal transit in a dose-dependent and AM251-sensitive manner. The in vivo GI effects of AM841 at 0.1 mg/kg were comparable to those induced by WIN at 5 mg/kg. However, at this dose, AM841 did not induce any sign of the cannabinoid tetrad, whereas WIN induced significant central effects. CONCLUSIONS & INFERENCES: The CB1R megagonist AM841 may potently depress GI motor function in the absence of central effects. This effect may be mediated peripherally and may be useful in the treatment of GI motility disorders.

Effects of chronic dietary exposure to monosodium glutamate on feeding behavior, adiposity, gastrointestinal motility, and cardiovascular function in healthy adult rats.

BACKGROUND: Monosodium glutamate (MSG) is a flavor-enhancer widely used as a food additive. However, its safe dietary concentration and its toxicity, including its possible implication in the recent metabolic syndrome pandemia, is still a controversial issue. Therefore, a deep knowledge of its effects upon regular dietary use is needed. Our aim was to evaluate the effects of chronic exposure to MSG on feeding behavior, abdominal fat, gastrointestinal motility, and cardiovascular function in rats. METHODS: Two groups of adult male Wistar rats were used: control and treated with MSG (4 g/L in drinking water) for 6 weeks. Different functional parameters were determined and the histological structure was analyzed in tissues of interest. KEY RESULTS: Compared to control animals, chronic MSG increased water intake but did not modify food ingestion or body weight gain. Neither the abdominal fat volume nor the fat fraction, measured by magnetic resonance imaging, was modified by MSG. Monosodium glutamate did not alter general gastrointestinal motility, but significantly increased the colonic response to mechanical stimulation. It slightly reduced endothelium-dependent relaxation in aorta, without significantly modifying any other cardiovascular parameters. No significant histological alterations were detected in salivary glands, intestinal wall, aorta, heart, and kidney. CONCLUSIONS & INFERENCES: Chronic treatment with MSG in the adult rat increased water intake. This supports its potential to improve acceptance of low-fat regimens and to increase hydration in the elderly and sportspeople, often at risk of dehydration. Changes in colonic contractility and cardiovascular function could have some long-term repercussions warranting further research.

Hormone regulation of the rodent Harderian gland: binding properties of the androgen receptor in the male golden hamster.

Studies were conducted in castrated golden hamsters to assess whether sexual dimorphism and sensitivity to sex steroid hormones in the rodent Harderian gland are mediated by an interaction of androgens with specific intracellular receptors. Physical properties, binding kinetics and stereospecificity of the androgen receptor were analysed using [3H]mibolerone as the radioligand. The presence of [3H]mibolerone-androgen receptor complexes with a sedimentation coefficient of 7-8S was demonstrated in Harderian gland cytosol by a linear sucrose gradient ultracentrifugation technique using a vertical rotor. Kinetic analysis revealed an androgen-binding site with an apparent dissociation constant of 0.3 +/- 0.07 (S.D.) nmol/l and a saturation binding capacity of 113 +/- 15 fmol/mg protein. Displacement studies indicated that unlabelled mibolerone, methyltrienolone, 5 alpha-dihydrotestosterone and testosterone were efficient competitors for the androgen-binding sites, while progesterone, 17 beta-oestradiol, dexamethasone, dehydroepiandrosterone, ethiocholanolone and 5 alpha-16-androsten-3-one were not. Experiments in longterm castrated animals revealed that the Harderian gland androgen receptor concentration and sedimentation coefficient remained unmodified. The results of these studies were interpreted as demonstrating the presence of a specific high-affinity intracellular androgen receptor in the male hamster Harderian gland.

Binding and effects of catecholestrogens on adenylate cyclase activity, and adrenoceptors, benzodiazepine and GABA receptors in guinea-pig hypothalamic membranes.

Catecholestrogen (CE) binding to guinea-pig hypothalamic membranes was assessed by using [3H]2-hydroxyestrone (2-OHE1) as a ligand. Binding was maximal at pH 7.4 and 37 degrees C, and after 10 min incubations. A high affinity binding site with dissociation constant (KD) = 0.20 +/- 0.02 nM and site concentration (Bmax) = 38 +/- 2 fmol/mg protein, and a low affinity binding site with KD = 235 +/- 10 nM and Bmax = 4.2 +/- 1.0 pmol/mg protein (n = 7) were detected. The order of affinity (Ki, microM) for displacement of 10 nM [3H]2-OHE1 from hypothalamic binding sites was 2-OHE1 (0.8), 2-hydroxyestradiol (2-OHE2) (1.0), epinephrine (5.9), norepinephrine (NE) (7.7), dopamine (270), estradiol, estrone, propranolol, phentolamine, domperidone (greater than 10 000). NE inhibition of 2-OHE1 binding was non-competitive, Only 0.5 mM 2-OHE2 depressed in a non-competitive way the hypothalamic beta-adrenoceptor binding (measured by using [3H]dihydroalprenolol) without affecting alpha-adrenoceptor binding (measured by using [3H]dihydroergocryptine). Both 2-OHE2 and 2-OHE1 impaired NE-stimulated adenylate cyclase activity in hypothalamic membranes with EC50 of about 5 and 10 microM, respectively. CE decreased [3H]gamma-aminobutyric acid binding by hypothalamic membranes with Ki = 8 microM (2-OHE2) and 50 microM (2-OHE1). The binding of [3H]flunitrazepam to the same membrane preparation was not affected by CE. These results support the existence of significant CE binding and effects in guinea-pig hypothalamic membranes.

In vitro conversion of 5-androstenediol to testosterone by the central nervous system and pituitary of the male rat.

The in vitro metabolism of 7-3H-5-androstenediol by the pituitary, some brain structures, and ventral prostate of adult castrated male rat was studied. Conversion of 5-androstenediol to radiochemically pure testosterone was demonstrated in all tissues studied in the presence of a NADPH generating system. Formation of dihydrotestosterone and dehydroepiandrosterone was also detected. The higher conversion rates were found in the pituitary, hypothalamus and mesencephalic tegmentum. These results demonstrate the presence of 3beta-hydroxy steroid oxidoreductase, delta4- delta5 isomerase, 5alpha-reductase, and 17beta-ol dehydrogenase in the rat brain which may in part explain the behavioral and brain virilization effects of 5-androstenediol.

In vitro metabolism of 3-H-androstenedione by the male rat pituitary, hypothalamus, and hippocampus.

The in vitro metabolism of 2,2-3-H-androstenedione by the pituitary, hypothalamus, and hippocampus of intact and castrated adult male rats was studied. Conversion of androstenedione to radiochemically pure 5alpha-androstanedione, testosterone, 5alpha-dihydrotestosterone, androsterone, and traces of 3alpha, 5alpha-androstanediol was demonstrated in minced preparations of the three tissues in the absence of cofactors. 5alpha-androstanedione was the metabolite formed in the highest proportion. The pituitary showed the highest enzymatic conversions followed in decreasing order by the hippocampus and the hypothalamus. Castration performed three weeks prior to the experiments resulted in a significant decrease of pituitary 17beta-old-dehydrogenase activity with a concomitant increase of 5alpha-reductase. No significant changes were observed after castration in the hypothalamus and the hippocampus.

[Endoscopic diagnosis of tumors of Vater's ampulla]. / Diagnóstico endoscópico de los tumores del ámpula de Vater.

The diagnosis of ampulla of Vater tumors is complex due to the proximity of other anatomical structures that are the originating sites of tumors with different natural histories, treatment and prognosis. A retrospective study of 65 consecutive patients with conclusive ampulla of Vater tumor diagnosis from January 1994 to April 1998 was conducted. Icterus was the principal symptom in 92%. In 34/65 patients on whom ultrasound or CT scan were performed, nearly half showed only dilation in the bile ducts, an ampullar tumor was suspected in six, in another six, pancreatic tumor was suspected and then discarded, and seven had no specific findings. Endoscopic imaging discovered the tumor in all of the cases, but the biopsy was diagnostic in only 84.6%: forty-eight carcinomas were discovered in addition to six adenomas (two with carcinoma and one with dysplasia) and one lymphoma. A diagnosis was arrived at in ten patients with negative biopsies through other means. Surgeries uncovered two carcinoids with endoscopic diagnosis of carcinoma. It was concluded that endoscopy is a good diagnostic method that allows palliation; however, it requires a perfecting process such as endoluminal ultrasound, specially if, taking into consideration the elevated morbimortality involved in pancreatoduodenectomies, conservative treatment is sought.

Cannabinoids may worsen gastric dysmotility induced by chronic cisplatin in the rat.

BACKGROUND: Although cannabinoids have traditionally been used for the treatment and/or prevention of nausea and/or emesis, anorexia and weight loss induced by clinical use of antineoplastic drugs, their efficacy and safety in long-term treatments are still controversial. Our aim was to analyze the effects of the non-selective cannabinoid agonist WIN 55 212-2 (WIN) on gastrointestinal (GI) dysmotility and other adverse effects induced by repeated cisplatin administration in the rat. METHODS: Male Wistar rats received two intraperitoneal injections once a week for 4 weeks: the first one was WIN, at non-psychoactive doses (0.5 or 1 mg kg(-1)), its vehicle or saline; the second one was cisplatin (2 mg kg(-1)) or saline. Radiographic techniques were used to determine the acute (after first dose), chronic (after last dose), and residual (1 week after treatment finalization) effects of cisplatin and/or WIN on GI motility. Bodyweight gain, food ingestion, and mechanical sensitivity were also tested. KEY RESULTS: Weekly cisplatin induced mechanical allodynia, which WIN prevented, as well as weight gain reduction and anorexia, which WIN did not. Gastric emptying was dose-dependently delayed by cisplatin and this effect was enhanced upon chronic treatment. WIN aggravated cisplatin-induced gastric dysmotility. One week after treatment finalization, only minor alterations of GI motor function were found in rats treated with cisplatin, WIN or both. CONCLUSIONS & INFERENCES: WIN weekly administered at low doses prevents neuropathy, but does not prevent anorexia or weight loss and aggravates gastric dysmotility induced by cisplatin. Cannabinoids should be handled with caution if chronically administered during chemotherapy.