Corneal stroma PDGF blockade and myofibroblast development

Myofibroblast development and haze generation in the corneal stroma is mediated by cytokines, including transforming growth factor-beta (TGF-beta), and possibly other cytokines. This study examined the effects of stromal PDGF-beta blockade on the development of myofibroblasts in response to -9.0 diopter photorefractive keratectomy in the rabbit. Rabbits that had haze generating photorefractive keratectomy (PRK, for 9 diopters of myopia) in one eye were divided into three different groups: stromal application of plasmid pCMV.PDGFRB.23KDEL expressing a subunit of PDGF receptor b (domains 2-3, which bind PDGF-B), stromal application of empty plasmid pCMV, or stromal application of balanced salt solution (BSS). The plasmids (at a concentration 1000 ng/mu l) or BSS was applied to the exposed stroma immediately after surgery and every 24 h for 4-5 days until the epithelium healed. The group treated with pCMV.PDGFRB.23KDEL showed lower alpha SMA+ myofibroblast density in the anterior stroma compared to either control group (P <= 0.001). Although there was also lower corneal haze at the slit lamp at one month after surgery, the difference in haze after PDGF-B blockade was not statistically significant compared to either control group. Stromal PDGF-B blockade during the early postoperative period following PRK decreases stromal alpha SMA+ myofibroblast generation. PDGF is an important modulator of myofibroblast development in the cornea. (C) 2008 Elsevier Ltd. All rights reserved.

Equal Numbers of Neuronal and Nonneuronal Cells Make the Human Brain an Isometrically Scaled-Up Primate Brain

The human brain is often considered to be the most cognitively capable among mammalian brains and to be much larger than expected for a mammal of our body size. Although the number of neurons is generally assumed to be a determinant of computational power, and despite the widespread quotes that the human brain contains 100 billion neurons and ten times more glial cells, the absolute number of neurons and glial cells in the human brain remains unknown. Here we determine these numbers by using the isotropic fractionator and compare them with the expected values for a human-sized primate. We find that the adult male human brain contains on average 86.1 +/- 8.1 billion NeuN-positive cells (""neurons"") and 84.6 +/- 9.8 billion NeuN-negative (""nonneuronal"") cells. With only 19% of all neurons located in the cerebral cortex, greater cortical size (representing 82% of total brain mass) in humans compared with other primates does not reflect an increased relative number of cortical neurons. The ratios between glial cells and neurons in the human brain structures are similar to those found in other primates, and their numbers of cells match those expected for a primate of human proportions. These findings challenge the common view that humans stand out from other primates in their brain composition and indicate that, with regard to numbers of neuronal and nonneuronal cells, the human brain is an isometrically scaled-up primate brain. J. Comp. Neurol. 513:532-541, 2009. (c) 2009 Wiley-Liss, Inc.

Haze Development After Photorefractive Keratectomy: Mechanical vs Ethanol Epithelial Removal in Rabbits

PURPOSE: To compare mechanical and ethanol epithelial removal with respect to myofibroblast development and haze formation after photorefractive keratectomy (PRK). METHODS: Seventeen rabbits underwent mechanical or ethanol debridement, and the opposite eye of each rabbit served as an unwounded control. In both groups, the epithelium was removed with a spatula and discarded. A -9.00-diopter PRK was performed in each eye. The level of haze in each cornea at 4 weeks was graded at the slit-lamp microscope according to the Fantes scale. Myofibroblast generation was detected with immunocytochemistry for alpha-smooth muscle actin (alpha-SMA) and cells were quantitatively analyzed. RESULTS: No difference was noted between the two groups in alpha-SMA + myofibroblasts 4 weeks after surgery (43.6 +/- 2.0/400X field and 45.7 +/- 4.8/400X field in ethanol and mechanical groups, respectively) (P=.10). A slight difference was noted but did not reach statistical significance with regard to stromal haze between ethanol and mechanical groups (2.0 +/- 0.5 and 2.3 +/- 0.4, respectively, P=.063). The ethanol and mechanical groups were statistically different when compared to controls regarding stromal haze and alpha-SMA+ cells (P <.0001 for all comparisons). CONCLUSIONS:No difference was noted in clinical haze or myofibroblast generation between corneas that had PRK with mechanical,or ethanol epithelial debridement. [J Refract Surg., 2008;24:923-927.]

The development of a rat model of erectile dysfunction after radical prostatectomy: preliminary findings

To develop a rat model of erectile dysfunction (ED) after cavernous nerve injury. Given the great similarity between the anatomical structure of the cavernous nerve in rats and humans, 24 rats underwent dissections and the cavernous nerves were identified with the aid of an operating microscope. Then the rats were randomized into two groups: sham-operated controls and a bilateral cavernous nerve section group. At 3 months after surgery, the rats were evaluated for their response to an apomorphine challenge. The erectile response after an apomorphine challenge was normal in all the control rats, while there were no erections in the bilateral injured group. The rat major autonomic ganglion and its cavernous nerve can be identified with the aid of a microscope. Rats are inexpensive and easy to handle, thus a good animal for developing an ED model of cavernous nerve injury. In the present study, the rats with cavernous nerve injury lost erectile capacity in a reliable and reproducible fashion. Because of the great similarity between the cavernous nerve of rats and humans, one may consider this technique as a reliable experimental model for studying ED after radical prostatectomy.

Topical interleukin-1 receptor antagonist inhibits inflammatory cell infiltration into the cornea

Interleukin (IL)-1 alpha and beta are important modulators of many functions of corneal epithelial and stromal cells that occur following injury to the cornea, including the influx of bone marrow-derived inflammatory cells into the stroma attracted by chemokines released from the stroma and epithelium. In this study, we examined the effect of topical soluble IL-1 receptor antagonist on bone marrow-derived cell influx following corneal epithelial scrape injury in a mouse model. C57BL/6 mice underwent corneal epithelial scrape followed by application of IL-1 receptor antagonist (Amgen, Thousand Oaks, CA) at a concentration of 20 mg/ml or vehicle for 24 h prior to immunocytochemical detection of marker CD11b-positive cells into the stroma. In two experiments, topical IL-1 receptor antagonist had a marked effect in blocking cell influx. For example, in experiment 1, topical IL-1 receptor antagonist markedly reduced detectible CD11b-positive cells into the corneal stroma at 24 It after epithelial injury compared with the vehicle control (3.5 +/- 0.5 (standard error of the mean) cells/400x field and 13.9 +/- 1.2 cells/400x field, respectively, p < 0.01). A second experiment with a different observer performing cell counting had the same result. Thus, the data demonstrate conclusively that topical IL-1 receptor antagonist markedly down-regulates CD-11b-positive monocytic cell appearance in the corneal stroma. Topical IL-1 receptor antagonist could be an effective adjuvant for clinical treatment of corneal conditions in which unwanted inflammation has a role in the pathophysiology of the disorder. (c) 2008 Elsevier Ltd. All rights reserved.

A randomized double-blind placebo-controlled trial to increase feasibility of dobutamine stress echocardiography in patients with hypertension

Objective: To increase dobutamine stress echocardiography feasibility in patients with uncontrolled hypertension, we studied 729 consecutive patients referred for ischemia assessment. Methods: Patients with blood pressure ( BP) levels above 160/ 110 mm Hg were randomized to sublingual placebo or captopril ( 25 mg), and dobutamine stress echocardiography undertaken if BP decreased below 160/ 110 mm Hg after 15 minutes. Results: Of 149 patients ( 20%) with high BP levels, 104 ( 63 +/- 11 years, 51 male) were randomized. Baseline BP levels were similar for captopril ( 178 +/- 15/ 103 +/- 15 mm Hg) and placebo ( 181 +/- 17/ 103 +/- 15 mm Hg) groups. After intervention, 15 patients from captopril and 17 from placebo group had decreased BP ( 11% and 12% for systolic and 13% and 13% for diastolic BP, respectively). Five patients from placebo group ( P =.007) had to prematurely terminate the test because of hypertension ( BP > 220/ 120 mm Hg). Feasibility was similar for captopril and placebo groups ( 35% vs 25%, respectively, P = not significant). Conclusion: Although both captopril and placebo are effective in increasing dobutamine stress echocardiography feasibility in patients with uncontrolled BP, test interruption because of hypertension is less likely to occur after captopril administration.

Immunoendocrinology of the Thymus in Chagas Disease

During immune response to infectious agents, the host develops an inflammatory response which could fail to eliminate the pathogen or may become dysregulated. In this case, the ongoing response acquires a new status and turns out to be detrimental. The same elements taking part in the establishment and regulation of the inflammatory response (cytokines, chemokines, regulatory T cells and counteracting compounds like glucocorticoids) may also mediate harmful effects. Thymic disturbances seen during Trypanosoma cruzi (T. cruzi) infection fit well with this conceptual framework. After infection, this organ suffers a severe atrophy due to apoptosis-induced thymocyte exhaustion, mainly affecting the immature double-positive (DP) CD4+CD8+ population. Thymus cellularity depletion, which occurs in the absence of main immunological mediators involved in anti-T. cruzi defense, seems to be linked to a systemic cytokine/hormonal imbalance, involving a dysregulated increase in Tumor Necrosis Factor alpha (TNF-alpha) and corticosterone hormone levels. Additionally, we have found an anomalous exit of potentially autoimmune DP cells to the periphery, in parallel to a shrinkage in the compartment of natural regulatory T cells. In this context, our data clearly point to the view that the thymus is a target organ of T. cruzi infection. Preserved thymus may be essential for the development of an effective immune response against T. cruzi, but this organ is severely affected by a dysregulated circuit of proinflammatory cytokines and glucocorticoids. Also, the alterations observed in the DP population might have potential implications for the autoimmune component of human Chagas disease. Copyright (C) 2011 S. Karger AG, Basel

Routine abdominal drains after Roux-en-Y gastric bypass: a prospective evaluation of the inflammatory response

Background: Despite the extensive published data regarding the use of drains in surgery, it is still controversial. Most bariatric surgeons use drains as routinely. However, drains have sometimes have been shown to be unhelpful and even to increase the anastomotic leak rates. The purpose of the present study was to evaluate the peritoneal inflammatory response in the presence of a drain left in place until the seventh postoperative day after bariatric surgery. Methods: All patients who underwent open Roux-en-Y gastric bypass from February 2007 to August 2008 were prospectively evaluated. A 24F Blake drain was left in place for 7 days. The peritoneal effluent from the drain was collected for the determination of cytokine levels and for microbiologic analysis. Results: A total of 107 obese patients were studied. A marked increase in the levels of tumor necrosis factor-alpha and interleukin-1 beta was observed by the seventh postoperative day, even in patients without any abdominal complications. Bacterial contamination of the peritoneal effluent was also demonstrated. Conclusion: The results of our study have shown that at 7 days after surgery, a marked peritoneal inflammatory response and bacterial contamination are present. These findings could have resulted from the use of the drain for 7 postoperative days. (Surg Obes Relat Dis 2010;6:648-652.) (C) 2010 American Society for Metabolic and Bariatric Surgery. All rights reserved.

Nutritional Course of Patients Submitted to Bariatric Surgery

Background Surgical treatment has proved to be effective for weight loss, improving the quality of life of obese individuals. However, metabolic and nutritional deficiencies may occur during the late postoperative period. The objective of the present study was to assess the metabolic and nutritional profile of grade III obese individuals for 12 months after Roux-en-Y gastric bypass (RYGBP). Methods Forty-eight patients with mean body mass index (BMI) of 51.9 +/- 7.8 kg/m(2) were submitted to RYGBP. Anthropometric, food intake, and biochemical data were obtained before and for 12 months after surgery. Results There was an average weight and body fat reduction of 35% and 46%, respectively. Calorie intake was reduced, ranging from 773 +/- 206 to 1035 +/- 345 kcal during the study. Protein intake remained below recommended values throughout follow-up, corresponding to 0.5 +/- 0.3 g/kg/current body weight/day during the 12th month. Iron and fiber intake was significantly reduced, remaining below recommended levels throughout the study. Serum cholesterol, low-density lipoprotein cholesterol, and glycemia were reduced. Albumin deficiency was present in 15.6% of subjects at the beginning of the study vs 8.9% at the end, calcium deficiency was present in 3.4% vs 16.7%, and iron deficiency was present in 12.2% vs 14.6%. Conclusions RYGBP was effective for weight loss and for the reduction of obesity rates and risk factors for comorbidities. The diet of these patients, who frequently present inadequate intake of macronutrients and micronutrients, should receive special attention. Patient follow-up and assessment at short intervals are necessary for an early correction of nutritional deficiencies.

Early Identification of Infectious Complications in Bariatric Surgery by the Determination of Peritoneal and Systemic Cytokines

Obesity has become a global epidemic and bariatric surgery is one of the therapeutic tools to deal with it. Postoperative complications can occur, such as staple line dehiscence and anastomotic leaks, leading to increased patient mortality. The diagnosis of these complications is frequently difficult. The objective of the present study was to determine whether peritoneal and systemic cytokines could early detect those complications. All patients who underwent open Roux-en-Y gastric bypass from February 2007 to August 2008 were prospectively evaluated. Blood and peritoneal effluent from the drain were collected for the determination of cytokine levels. We also evaluated the clinical signs and the leukograms of the patients. A total of 107 obese patients were studied. Ninety patients had no complications; 17 had at least one infectious complication which include five cases of staple line dehiscence. Until the third postoperative day, the vital signs and the leukogram did not predict the onset of infectious complications, but the cytokines (interleukin-1 beta and interleukin-6) were early markers of these complications. Cytokines are good predictors of poor postoperative evolution in bariatric surgery since peritoneal cytokines diagnose better these infectious complications even before changes in blood count and before the occurrence of clinical manifestations.