The proabsorptive effect of D-ala2-metenkephalinamide is mediated by naloxone-sensitive opiate receptors in the isolated perfused ileum

Methionine-enkephalin is an endogenous opiate pentapeptide, originally isolated in the brain, that exists within enteric plexuses and enterocytes. The purpose of this study was to delineate the effects of the opiate agonist methionine-enkephalin on intestinal water and electrolyte transport, with the stable analog D-ala2-metenkephalinamide (m-ENK). Ileal segments from New Zealand white rabbits (n = 39) were harvested and vascularly and luminally perfused ex vivo. Net fluxes of H2O, Na+, and Cl- were calculated for three 20-minute periods: basal, drug infusion, and recovery. Six groups were studied: (1) control, (2-4) m-ENK at three doses, (5) naloxone, and (6) naloxone plus m-ENK. Oxygen consumption and arterial perfusion pressure were assessed as measures of metabolic activity and viability. The control and naloxone groups had no changes in the fluxes of water and electrolytes. Significant proabsorptive effects were demonstrated for the fluxes of H2O, Na+, and Cl- at increasing doses of m-ENK (p less than 0.05). Naloxone completely prevented m-ENK-induced absorption. These results with exogenous m-ENK suggest that endogenous methionine-enkephalin, serving as an enteric neurotransmitter and acting through naloxone-sensitive opiate receptors, may function as a physiologic modulator of intestinal water and electrolyte absorption.     

Human spermatozoa motility analysis in a Ringer's solution containing cupric ions

The ability of cupric ions to immobilize human spermatozoa was assessed in vitro using an optical microscope. A Ringer's solution containing human spermatozoa and three cupric ion concentrations of 8 x 10(-8) mol/L, 8 x 10(-6) mol/L and 8 x 10(-5) mol/L were tested. The higher cupric ion concentrations (8 x 10(-5) mol/L and 8 x 10(-6) mol/L) significantly reduced spermatozoa motility after about 20 min. However, with the lower cupric ion concentration tested (8 x 10(-8) mol/L), also for 20-min experimentation, the reduction in motility was more limited.     

Phase II trial of preoperative 3D conformal radiotherapy,protracted venous infusion 5-fluorouracil,and weekly CPT-11, followed by surgery for ultrasound-staged T3 rectal cancer

PURPOSE: CPT-11 sensitizes tumor cells to radiation and in combination therapy with 5-fluorouracil (5-FU) results in enhanced cytotoxicity to metastatic colorectal cancer. We report the results from a Phase II trial of preoperative radiotherapy (RT), CPT-11, and 5-FU for patients with ultrasound-staged T3 rectal cancer. METHODS AND MATERIALS: Between April 1999 and August 2001, 32 patients (21 men, 11 women; median age 52 years, range 40-74) with biopsy-proven adenocarcinoma of the rectum were enrolled in the study. All patients underwent endorectal ultrasonography for staging (uT3N0 = 19; uT3N1 = 13; uT2N1 = 1). RT was prescribed to the draining lymph nodes (45 Gy in 1.8-Gy daily fractions) and tumor (50.4 Gy in 1.8-Gy daily fractions). Patients also received concurrent CPT-11 (50 mg/m(2), Days 1, 8, 15, and 22) and 5-FU (200 mg/m(2) daily, 7 d/wk, Days 1-33). Surgical resection was performed 6-10 weeks after completing chemoradiotherapy. RESULTS: Acute toxicity was frequently observed, and 18 patients (56%) required either a chemotherapy dose reduction or RT interruption of >3 days. One patient withdrew because of diarrhea and abdominal cramping (Grade III) after 10 days of treatment. Although no Grade IV toxicity was observed, Grade III diarrhea (n = 9, 28%), mucositis (n = 7, 21%), rectal sores (n = 7, 21%), abdominal cramping (n = 3, 9%) were noted. Of the 32 patients who underwent surgery, 12 had a complete pathologic response. Of the 32 patients, the disease of 23 (71%) was downstaged. The average length of hospitalization was between 5 and 12 days, with 1 patient staying 33 days. All patients were followed for disease-free survival. CONCLUSION: Although associated with frequent acute toxicity, the regimen is associated with significant tumor "downstaging." Additional patients and longer follow-up are necessary to define the role of this regimen fully.     

Use of recombinant human antibody fragments for detection of cytomegalovirus antigenemia.

The determination and quantitation of peripheral blood leukocytes (PBLs) expressing human cytomegalovirus (HCMV) antigens is widely employed in clinical virology for rapid diagnosis of HCMV-related infections. We describe how CMV antigenemia may be accurately detected by means of human recombinant monoclonal Fab fragments rescued from a combinatorial phage display library prepared from an HCMV-infected donor. Fourteen recombinant Fabs were tested against HCMV-positive PBLs from a patient with ongoing HCMV infection. Three clones were found to react specifically with the nuclei of these cells. These three recombinant Fabs were subsequently tested, individually and pooled together, against 60 PBL samples taken from immunosuppressed patients. The reactivity observed was comparable to that obtained with mouse monoclonal antibodies commercially available for this purpose. The three recombinant Fabs were shown to react specifically with the 65-kDa viral tegument phosphoprotein encoded by UL83 (pUL83), which is the most abundant viral antigen in HCMV-infected PBLs.     

Intralesional isotype profiles in human localized cutaneous leishmaniasis lesions

This immunocytochemical study evaluates the presence of IgG1-4, IgA and IgE immunoglobulins in active lesions of 25 localized cutaneous leishmaniasis patients from three bioclimatic areas (Awa, Afa and Bsha) in Mérida State, Venezuela. All immunoglobulin isotypes except IgE were detected, with variable intensity, in one or more of the epidermal or dermal components of skin lesions. IgG1 and IgG2 were detected significantly more frequently than IgG3, IgG4 and IgA. The ranking of the isotypes according to frequency of detection was the same in all areas: IgG1 = IgG2 > IgG3 = IgG4 = IgA, but considered as whole, all isotypes were detected significantly more frequently in patients from the Awa area than in those from the Bsha area. The predominant expression of isotypes IgG1 and IgG2 suggests a preferential Th1 like immune response. Anti-Leishmania immunoserum stained only parasites and their debris, suggesting that most of the immunostaining was nonspecific.     

Effect of reactive oxygen species scavengers,antiinflammatory drugs,and calcium-channel blockers on carbon dioxide pneumoperitoneum-enhanced adhesions in a laparoscopic mouse model

Background Postoperative adhesions are a clinical problem. They can cause female infertility, intestinal obstruction, chronic pelvic pain, and difficulties at the time of reoperation. A variety of approaches described to prevent adhesions have shown variable and inconsistent results. Therefore, this study aimed to evaluate most known substances in a laparoscopic mouse model to obtain quantitative and comprehensive information on adhesion prevention. Specifically, this first study aimed to investigate the effects of reactive oxygen species (ROS) scavengers, antiinflammatory agents, and a calcium-channel blocker on pneumoperitoneum-enhanced adhesions. Methods Adhesions were induced during laparoscopy in BALB/c female mice by creation of a bipolar lesion. Carbon dioxide (CO₂) pneumoperitoneum was maintained for 60 min using humidified CO₂. Six experiments were conducted to evaluate the effects of ROS scavengers (superoxide dismutase [SOD], catalase, melatonin, and ascorbic acid), antiinflammatory agents (dexamethasone, tenoxicam, ibuprofen, parecoxib, nimesulide, anti–tumor necrosis factor [TNF]-alpha), and a calcium-channel blocker (diltiazem). Adhesions were scored after 7 days during laparotomy. Results Adhesions were reduced by SOD (p < 0.01, proc general linear methods (GLM) of experiments 1 and 2), diltiazem (p = 0.05, Wilcoxon), and dexamethasone (p < 0.03), but not by nonsteroidal antiinflammatory drugs (NSAIDs) nor by anti–TNF-alpha. When all the experiments were grouped for analysis, adhesions also decreased with one and three doses of SOD (p < 0.01 and p < 0.01, respectively) and with one and three doses of ascorbic acid (p < 0.02 and p = 0.05, respectively). Conclusions These experiments confirm that SOD, diltiazem, and dexamethasone can decrease adhesion formation. The absence of effect from the other antiinflammatory drugs and anti-TNF-alpha is surprising. Presented at the XV Annual Congress of the International Society for Gynecological Endoscopy (ISGE), 29 March to 1 April, 2006, Buenos Aires, Argentina