Acute experimental pancreatitis in rat induced by sodium taurocholic acid: objective quantification of pancreatic necrosis

Summary Retrograde injection of 5% sodium taurocholic acid (TA) in Wistar rat pancreatic duct is followed by acute pancreatitis, resulting in 100% mortality within 36 h. Biochemical determinations show raised levels of amylase in ascites and blood. Necrosis has been measured using seven morphometric characteristics of pathological changes that add precise information on the type and extension of the pancreatic lesion. The percentage of necrotic tissue (by area) seems to be the most objective parameter. Necrosis appears 6 h after TA infusion, being 5.77% in extent after 12h, 14.9% after 24 h and animals die with an area of 29.5% necrosis. This experimental model seems to one in which physiopathological and therapeutic trials on acute pancreatitis may be camed out.     

Resumen ejecutivo del Documento de Consenso de la Sociedad Española de Enfermedades Infecciosas y Microbiología Clínica (SEIMC) y de la Asociación Española de Cirujanos (AEC) en profilaxis antibiótica en cirugía

Antibiotic prophylaxis in surgery is one of the most effective measures for preventing surgical site infection, although its use is frequently inadequate and may even increase the risk of infection, toxicities and antimicrobial resistance. As a result of advances in surgical techniques and the emergence of multidrug-resistant organisms, the current guidelines for prophylaxis need to be revised.The Sociedad Española de Enfermedades Infecciosas (Spanish Society of Infectious Diseases and Clinical Microbiology) (SEIMC) together with the Asociación Española de Cirujanos (Spanish Association of Surgeons) (AEC) have revised and updated the recommendations for antibiotic prophylaxis in surgery to adapt them to any type of surgical intervention and to current epidemiology. This document gathers together the recommendations on antimicrobial prophylaxis in the various procedures, with doses, duration, prophylaxis in special patient groups, and in epidemiological settings of multidrug resistance to facilitate standardized management and the safe, effective and rational use of antibiotics in elective surgery.     

Restraint-induced stress ulcer. I. Hypothalamic,urinary, and adrenal biochemical studies

The purpose of these experiments was to study the incidence of stress ulcers in restrained rats and to correlate it with hypothalamic and adrenal cortical and medullary activity, with and without vagotomy. A total of 217 adult rats were used, grouped into 56 sets, and distributed at random in 5 experimental groups. Restraint was followed by a 79% incidence of ulceration in the glandular portion of the gastric mucosa. Vagotomy made these worse (p<0.01). Hypothalamic levels of catecholamines and serotonin showed no significant changes. Urinary measurements revealed decreased excretion of 17-ketosteroids (p<0.001), increased excretion of uropepsinogen (p<0.01), and no significant changes in vanillylmandelic acid among the rats submitted to immobilization. In the adrenal glands of stressed animals, there was a decreased level of catecholamines (p<0.01) and no significant changes in corticosteroid content (17-ketosteroids). These results suggest that hypothalamic stimulation and the participation of the adrenal glands are not essential factors in the pathogenesis of restraint-induced experimental stress ulcer.     

Treatment of Vitamin D Deficiency with Calcifediol: Efficacy and Safety Profile and Predictability of Efficacy

Calcifediol (25-OH-vitamin D3) is the prohormone of the vitamin D endocrine system. It is used to prevent and treat vitamin D deficiency. Calcifediol, as well as cholecalciferol (vitamin D3), is efficient and safe in the general population, although calcifediol has certain advantages over cholecalciferol, such as its rapid onset of action and greater potency. This review analyzed studies comparing the efficacy and safety of both calcifediol and cholecalciferol drugs in the short and long term (>6 months). Calcifediol was found to be more efficacious, with no increase in toxicity. We also assessed the predictability of both molecules. A 25OHD increase depends on the dose and frequency of calcifediol administration. In contrast, after cholecalciferol administration, 25OHD increase depends on more factors than dose and frequency of administration, also phenotypic aspects (such as obesity and malabsorption), and genotypic factors impacts in this increase.     

Glucagon-like peptide-1(7-36) amide stimulates surfactant secretion in human type II pneumocytes

To determine the influence of glucagon-like peptides on the secretion of human pulmonary surfactant, we used human type II pneumocytes. In these cells, GLP-1(7-36) amide and exendin-4 stimulated phosphatidylcholine secretion (PC) and cAMP formation in a concentration-dependent manner; these effects were reversed by exendin(9-39). No changes were observed with other related peptides. The mechanism by which GLP-1(7-36) amide exerts its stimulatory effect was investigated with various agents that are well known to be stimulators or inhibitors of PC secretion. Thus, 8-bromo-cAMP increased and both Rp-cAMPS and H-89, the latter an inhibitor of protein kinase A (PKA), reduced pulmonary surfactant secretion in type II pneumocytes. Also, GLP-1(7-36) amide and TPA exerted additive effects in stimulating PC secretion, and Calph C, a potent inhibitor of protein kinase C (PKC), blocked most of the effect of GLP-1(7-36) amide. By contrast, both the calcium ionophore A23187 and GLP-1(7-36) amide had additive effects in increasing PC secretion, and the specific inhibitor of Ca(2+)-calmodulin-dependent protein kinase (Ca-CM-PK), KN-62, inhibited the effect of A23187 but did not alter the stimulatory action of GLP-1(7-36) amide. Our findings suggest that both PKA and PKC are involved in the stimulatory effects of GLP-1(7-36) amide on PC secretion, whereas this peptide has no effect on PC secretion through a Ca-CM-PK mechanism.     

3p21, 5q21, 9p21 and 17p13.1 allelic deletions are potential markers of individuals with a high risk of developing adenocarcinoma in Barrett's epithelium without dysplasia

BACKGROUND/AIMS: A common genetic abnormality detected in Barrett's adenocarcinoma is LOH (loss of heterozygosity) at the sites of known or putative tumor suppressor genes. Thus, some deletions have also been determined in peritumoral Barrett's epithelium. These findings suggest that a tissue field of somatic genetic alterations precede the histopathological phenotypic changes of carcinoma. We investigated 32 cases of Barrett's esophagus with no evidence of dysplasia for LOH at 5q21 (APC), 3p21, 9p21 (p16) and 17p13.1 (p53) chromosomal regions. METHODOLOGY: Two groups were randomly selected and compared: 16 cases of Barrett's epithelium adjacent to adenocarcinoma and 16 cases of Barrett's epithelium with no evidence of malignant transformation in a 5-10 years follow-up period. In three adenocarcinomas cases several previous endoscopic biopsies of Barrett's esophagus were available. RESULTS: We determined frequent allelic losses in adenocarcinomas at p53 (54%), p16 (50%), 3p21 (40%) and 5q21 (33%). Identical LOH was present in most cases in the Barrett's epithelium adjacent to adenocarcinoma. LOH at these loci was unusual in Barrett's epithelium with no evidence of malignant transformation. However, in cases where sequential endoscopic biopsies were performed in advance to the adenocarcinoma diagnosis LOH was already present in the Barrett's epithelium. CONCLUSIONS: We suggest that LOH at these loci may be present before the onset of the malignant growth and LOH studies may supplement the histopathological evaluation of Barrett's epithelium. LOH at 3p21, 5q21, 9p21 and 17p13 chromosomal regions in cells of Barrett's epithelium without dysplasia may have a role as a potential marker for individuals with a high risk of developing adenocarcinoma.     

Nogo receptor antagonizes p75NTR-dependent motor neuron death

The Nogo-66 receptor (NgR) plays a critical role in restricting axon regeneration in the central nervous system. This inhibitory action is in part mediated by a neuronal receptor complex containing p75NTR, a multifunctional receptor also well known to trigger cell death upon binding to neurotrophins such as NGF. In the present study, we show that Pep4 and NEP1-40, which are two peptides derived from the Nogo-66 sequence that modulate NgR-mediated neurite outgrowth inhibition, prevent NGF-stimulated p75NTR-dependent death of cultured embryonic motor neurons. They also confer protection on spinal cord motor neurons after neonatal sciatic nerve axotomy. These findings demonstrate an as-yet-unknown function of NgR in maintaining neuronal survival that may be relevant for motor neuron development and degeneration.     

Double-blind,randomized pilot study of bioadhesive chlorhexidine gel in the prevention and treatment of mucositis induced by chemoradiotherapy of head and neck cancer

Background

To evaluate, in an initial way, the effectiveness of bioadhesive chlorhexidine gel 0.2% versus placebo as a preventive and therapeutic intervention of oral mucositis induced by radiation therapy and chemotherapy in patients diagnosed with head and neck cancer treated with chemoradiotherapy.

Material and Methods

In this pilot study, 7 patients (range of age: 18- 65), having histological documented diagnosis of squamous carcinoma on the head and neck region in stage III and IV, and receiving combined radiation treatment and chemotherapy (cisplatin 100 mg/m2 IV on days 1, 22, and 43 of irradiation) were studied. Simultaneously, a topical application was performed with bioadhesive chlorhexidine gel 0.2% in the study group, and the placebo gel for the control group in 5 applications per day, from the time of initiation of cancer treatment to 2 weeks after completion of chemo-radiotherapy treatment (11 weeks of follow-up). The gradation of mucositis, pain, analgesic consumption, infectious complications, and treatment tolerance was measured.

Results

After 7 patients completed the protocol, any differences were observed between groups in an interval analysis. Mucositis, pain, and tolerance was similar in both groups.

Conclusions

Our results must be interpreted with caution due to the reduced sample size, but the use of bioadhesive chlorhexidine gel 0.2% didn’t contribute clinical improvement to the oral mucositis induced by radiation therapy and chemotherapy. Key words: Chlorhexidine, mucositis, head and neck cancer.