Total Histological Score Research Articles

Treatment of Experimental Anterior and Intermediate Uveitis by a Dexamethasone Intravitreal Implant

To assess the efficacy of a dexamethasone (DEX) intravitreal implant in a rabbit model of anterior and intermediate uveitis. Experimental anterior and intermediate uveitis was induced by a unilateral intracameral injection of Mycobacterium tuberculosis H37Ra antigen in preimmunized rabbits. Four days after uveitis induction, rabbits received DEX implant or underwent a sham procedure (no implant). Clinical and histopathologic signs of uveitis were assessed for 13 days, and levels of inflammatory markers in the iris/ciliary body were measured after 21 days. All signs of anterior and intermediate uveitis were reduced by the DEX implant compared with sham procedure. At day 13, mean anterior chamber cell scores ± SD for the DEX implant versus the sham procedure were, respectively, 1.9 ± 1.3 versus 4.0 ± 0.0 (P = 0.04), and mean total histologic inflammatory scores were 3.9 ± 2.5 versus 15.4 ± 6.0 (P = 0.026). Similarly, at day 13, mean vitreous haze severity scores (SD) for the DEX implant versus the sham procedure were, respectively, 0.1 ± 0.2 versus 2.7 ± 1.5 (P = 0.026), and mean vitreous inflammatory cell infiltration scores were 0.0 ± 0.0 versus 1.5 ± 1.3. Treatment with the DEX intravitreal implant also significantly reduced the proinflammatory immune response, as measured by cytokine levels in iris/ciliary body. A single administration of DEX implant significantly reduced inflammation in an animal model of anterior and intermediate uveitis.

Morphological and neuro-behavioral parallels in the rat model of stroke

Middle cerebral artery occlusion (MCAO) is widely used as a rat model of focal brain ischemia. Evaluation of brain damage often includes the morphological analysis of the injury area, MRI, and various scales which depend on functional tests, commonly known as neurological severity score (NSS). We determined the optimal number of NSS tests and assessed their capacity for non-invasive evaluation of brain ischemic injury in the rat MCAO model. 275 male Sprague-Dawley rats were randomly divided into five groups, given either permanent (p) MCAO or transient (t) MCAO using an uncoated 4-0 monofilament catheter or a silicone-coated monofilament. The rats’ neurological status was examined before and at 1 and 24 h following MCAO. The size of brain injury was then measured histologically and the extent of right cerebral hemisphere edema was calculated. We established a correlation between these tests and morphological data for brain injury. Adjusted R 2 of the prediction of total histology score was 0.7. The Hosmer–Lemeshow p-value of this model was 0.812 for total brain histology. For the brain edema the adjusted R 2 of the prediction model was 0.48. The Hosmer–Lemeshow p-value of this model was 0.558 for brain edema. Our methods of estimating infarct size produces reliable and well correlated results at 24 h and demonstrates to be an easy and quick way to assess infarct size soon after ischemic injury has occurred. The described method for neurological assessment could ultimately aid in assessing various treatment modalities in the early hours following stroke.

Significance of Preimplantation Analysis of Kidney Biopsies From Expanded Criteria Donors in Long-Term Outcome

The shortage of organs has led to expanding the criteria for donors. Histologic evaluations before transplantation may enable the identification of organs unsuitable for single implantation. The aim of this study was to evaluate the histologic findings as prognostic factors of allograft survival from expanded criteria donors (ECDs). We included a cohort of 136 single transplantations with kidneys from ECD and correlated the preimplantation pathologic findings with graft failure. Renal structures from ECD older (n=104) or younger (n=32) than 60 years were evaluated histologically for renal senescence and rated with a total histologic score. A multivariate Cox analysis was performed to identify predictors of graft failure. Glomerulosclerosis was the most prevalent lesion in biopsies from donors older and younger than 60 years (P=0.002); interstitial fibrosis was more severe in biopsies from older donors (P=0.001); older donors showed a higher prevalence of tubular atrophy (P=0.022), and vascular compartment showed no significant differences. Kidney biopsy-based scoring system ranged from 0 to 15 points, indicating the presence of changes in the renal parenchyma. Biopsies with total histologic scores less than or equal to 5 showed significantly better 5-year graft survival than those with scores more than 5 (P<0.001). A preimplantation score more than 5 points remained an independent predictor of graft failure (hazard ratio 6.95; 95% confidence interval 1.57-30). Histologic analysis of kidney biopsies before transplantation is a valuable tool for facilitating the selection of viable grafts from ECD donors. When the total score is more than 5, single kidney transplantation from ECD should not be recommended for patients similar to this study population.

Early myocardial injury is an integral component of experimental acute liver failure - a study in two porcine models.

IntroductionThere is accumulating clinical evidence that acute liver failure may be regularly associated with myocardial injury. To test this hypothesis in a standardized experimental setting, we used two porcine models of ALF.Material and methodsIn 14 domestic pigs ALF was induced by either a) surgical devascularization of the liver (DV group, n = 7), or b) partial (70-75%) hepatectomy and ischaemia/reperfusion of the liver remnant for 150 min (I/R group, n = 7). Four additional animals constituted the sham operation group. All animals were monitored for a 12-h period, at the end of which their hearts were harvested. Plasma troponin I (cTnI) and malondialdehyde (MDA) were measured before the operation (baseline) and at 6 h and 12 h postoperatively. The harvested hearts were histologically analysed, appointing a score from 0 (no injury) to 3 (maximum injury) to selected injury indicators.ResultsIn the sham group, all cTnI measurements and total myocardial injury score were zero in all animals. In both ALF groups, plasma cTnI levels increased by the 6th and remained elevated up to the 12th postoperative hour (p < 0.01 vs. sham animals). Total myocardial injury score and total histological score revealed some extent of myocardial injury. The rise of MDA levels suggests an underlying oxidative mechanism.ConclusionsOur study provides direct evidence of early myocardial injury in the setting of acute liver failure in pigs. The mechanism of injury remains to be elucidated.

Hydroxyethyl Starch 6% (130/0.4) Ameliorates Acute Lung Injury in Swine Hemorrhagic Shock

Traumatic hemorrhage induces acute lung injury. The aim of this study was to assess whether lactated Ringer's solution or 6% hydroxyethyl starch 130/0.4 would have different effects on acute lung injury following hemorrhagic shock. Twenty healthy pigs (19 ± 2 kg) were subjected to hemorrhage and were randomly allocated to two groups: Group A (10 pigs) who received lactated Ringer's solution and Group B (10 pigs) who received hydroxyethyl starch 130/0.4. Hemodynamic response and serum lactate were measured at predetermined phases. Four hours after fluid resuscitation animals were euthanized. Lungs were harvested, and tissue samples were collected. Focal thickening of the alveolar membranes, vascular congestion, number of activated neutrophils, alveolar edema, interstitial neutrophil infiltration, intraalveolar infiltration, and alveolar hemorrhage were assessed. Each feature was given a score from 0 to 3 (0 = absence, 3 = severe). The wet/dry ratio was also calculated, and with the use of Evans blue dye extravasation method, capillary permeability was assessed. The total histology score of Group A differed significantly from that of Group B, being significantly lower in Group B animals P = 0.048. The wet/dry weight ratio was significantly higher in the lactated Ringer's group (median [range]) (Group A, 5.1 [0.5]; Group B, 4.9 [0.3]; P = 0.009). The Evans blue dye extravasation method was utilized to study the lung capillary permeability. The animals in Group B showed a marked reduction in microvascular capillary permeability compared with the animals in Group A (Group A, 58.5 [21] mg/g; Group B, 51.5 [14] mg/g; P = 0.017). Our study indicates that resuscitation after hemorrhagic shock with hydroxyethyl starch 130/0.4 led to less lung edema and less microvascular permeability in this swine model.

Pretreatment of periosteum with TGF-β1 in situ enhances the quality of osteochondral tissue regenerated from transplanted periosteal grafts in adult rabbits

To compare the efficacy of in situ transforming growth factor-beta1 (TGF-beta1)-pretreated periosteum to untreated periosteum for regeneration of osteochondral tissue in rabbits. In the pretreatment group, 12 month-old New Zealand white rabbits received subperiosteal injections of 200 ng of TGF-beta1 percutaneously in the medial side of the proximal tibia, 7 days prior to surgery. Control rabbits received no treatment prior surgery. Osteochondral transverse defects measuring 5mm proximal to distal and spanning the entire width of the patellar groove were created and repaired with untreated or TGF-beta1-pretreated periosteal grafts. Post-operatively the rabbits resumed normal cage activity for 6 weeks. Complete filling of the defects with regenerated tissue was observed in both the TGF-beta1-pretreated and control groups with reformation of the original contours of the patellar groove. The total histological score (modified O'Driscoll) in the TGF-beta1-pretreated group, 20 (95% Confidence Interval (CI), 19-21), was significantly higher (P=0.0001) than the control group, 18 (16-19). The most notable improvements were in structural integrity and subchondral bone regeneration. No significant differences in glycosaminoglycan or type II collagen content, or equilibrium modulus were found between the surgical groups. The cambium of the periosteum regenerated at the graft harvest site was significantly thicker (P=0.0065) in the TGF-beta1-pretreated rabbits, 121 microm (94-149), compared to controls, 74 microm (52-96), after 6 weeks. This study demonstrates that in situ pretreatment of periosteum with TGF-beta1 improves osteochondral tissue regeneration at 6-weeks post-op compared to untreated periosteum in 12 month-old rabbits.

Supplementation of diet with krill oil protects against experimental rheumatoid arthritis

BackgroundAlthough the efficacy of standard fish oil has been the subject of research in arthritis, the effect of krill oil in this disease has yet to be investigated. The objective of the present study was to evaluate a standardised preparation of krill oil and fish oil in an animal model for arthritis.MethodsCollagen-induced arthritis susceptible DBA/1 mice were provided ad libitum access to a control diet or diets supplemented with either krill oil or fish oil throughout the study. There were 14 mice in each of the 3 treatment groups. The level of EPA + DHA was 0.44 g/100 g in the krill oil diet and 0.47 g/100 g in the fish oil diet. Severity of arthritis was determined using a clinical scoring system. Arthritis joints were analysed by histopathology and graded. Serum samples were obtained at the end of the study and the levels of IL-1α, IL-1β, IL-7, IL-10, IL-12p70, IL-13, IL-15, IL-17 and TGF-β were determined by a Luminex™ assay system.ResultsConsumption of krill oil and supplemented diet significantly reduced the arthritis scores and hind paw swelling when compared to a control diet not supplemented with EPA and DHA. However, the arthritis score during the late phase of the study was only significantly reduced after krill oil administration. Furthermore, mice fed the krill oil diet demonstrated lower infiltration of inflammatory cells into the joint and synovial layer hyperplasia, when compared to control. Inclusion of fish oil and krill oil in the diets led to a significant reduction in hyperplasia and total histology score. Krill oil did not modulate the levels of serum cytokines whereas consumption of fish oil increased the levels of IL-1α and IL-13.ConclusionsThe study suggests that krill oil may be a useful intervention strategy against the clinical and histopathological signs of inflammatory arthritis.

Pulsed electromagnetic field therapy results in healing of full thickness articular cartilage defect

This study aimed to determine the efficacy of PEMF (pulsed electromagnetic field) treatment in experimental osteochondral defect healing in a rabbit model. The study was conducted on 12 New Zealand white rabbits. Six rabbits formed the study group and six rabbits the control group. The right knee joints of all 12 animals were exposed and a 3.5-mm diameter osteochondral defect was created in the trochlear groove. The defect was filled with calcium phosphate scaffold. Six animals from the study group were given PEMF of one hour duration once a day for sixweeks with set parameters for frequency of 1Hz, voltage 20V, sine wave and current ±30mA. At six weeks the animals were sacrificed and histological evaluation was done using H&E, Safranin O, Maissons trichrome staining and immunohistochemistry for type 2 collagen. The quality of the repair tissue was graded and compared between groups with the Wakitani histological grading scale and a statistical analysis was done. The total histological score was significantly better in the study group (p = 0.002) with regeneration similar to adjacent normal hyaline cartilage. Immunohistochemistry for collagen type II was positive in the study group. PEMF stimulation of osteochondral defects with calcium phosphate scaffold is effective in hyaline cartilage formation. PEMF is a non-invasive and cost effective adjuvant treatment with salvage procedures such as abrasion chondroplasty and subchondral drilling.

Moderate levels of dietary sheep milk powder reduce experimentally induced colonic inflammation in rats

Anecdotal evidence suggests that sheep milk may be more beneficial than cow milk for people with intestinal health problems; however, there are no published reports on the effects of sheep milk on intestinal function. Our hypothesis was that sheep milk powder can reduce the severity of colonic inflammation in rats with dextran sodium sulfate (DSS)-induced colitis. A preliminary experiment investigated the palatability of sheep milk powder in the diet of 5-week-old rats with (n = 8) or without (n = 8) DSS-induced colitis. Increasing sheep milk powder from 11 to 56% in the diet had no effect (P &gt; 0.05) on food intake, showing that rats readily eat low and high levels of sheep milk powder in the diet, with or without DSS. Experiment 2 investigated the effects of moderate levels of sheep milk powder (11%) in rat diet on colon morphology, colonic biochemical markers of intestinal function, and caecal short-chain fatty acid concentrations, with (n = 8) or without (n = 8) DSS-induced colitis. Colon total histological injury scores decreased and caecal concentrations of butyric and propionic acids were increased (P &lt; 0.05) in DSS rats fed moderate (11%) dietary levels of sheep milk powder. Experiment 3 investigated the effects of high levels (56%) of sheep milk powder in rat diet on colonic markers of intestinal inflammation, and caecal microbial populations, with (n = 11) or without (n = 8) DSS-induced colitis. Sheep milk powder at 56% of the diet had no effect on colonic biochemical markers of intestinal health, or on caecal short-chain fatty acid concentrations. However, the caecal digesta concentrations of beneficial microbial populations (lactobacilli, bifidobacteria and clostridia) were increased (P &lt; 0.05) and the concentrations of potentially harmful bacteria (coliforms) were decreased (P &lt; 0.05). These results suggest the benefits of moderate levels of sheep milk during DSS-induced colonic inflammation may be due to alterations in the caecal microbiota composition, and further investigation into its health benefits are warranted.

Replacement of the Condyle and Ascending Ramus by a Modular Endoprosthesis in Macaca fascicularis—Part 2: Microcomputed Tomographic and Histologic Evaluation of the Ramus and Stem

The present study presents the microcomputed tomographic and histologic evaluation of the peri-implant tissues of a modular endoprosthesis used to replace the condyle and ascending ramus in Macaca fascicularis. The right condyle and ascending ramus were resected in 8 adult monkeys and replaced by a modular endoprosthesis, fixed with polymethylmethacrylate bone cement (Palacos). Four monkeys were sacrificed at 3 months and 4 at 6 months postoperatively. Microcomputed tomographic scanning was performed to analyze the bone volume at the bone-cement interface. Histologic and histomorphometric assessments were done using a modified hard and soft tissue grading scale and by studying the total bone contact at the interface. The combined (buccal, lingual, and inferior) mean bone volume percentage of the 6-month group was significantly greater than that of the 3-month group (P < .05). The 6-month specimens showed a reduced inflammatory response and more abundant bone formation around the stem. The total soft tissue histologic score was significantly greater in the 6-month group (P < .05). A total bone contact percentage of 15.4% to 85.2% was achieved in 3 specimens. Satisfactory bone growth was found at the bone-cement interface at the stem region, although direct bone contact with the cement was not achieved in all cases. Soft tissue contact with the prosthetic ramus, in the form of a fibrous capsule, was present in some areas. At 6 months, minimal interfacial inflammation was found in this monkey model.

Hypothermic extracorporeal circulation in immature swine: a comparison of continuous cardiopulmonary bypass, selective antegrade cerebral perfusion and circulatory arrest☆

Selective antegrade cerebral perfusion (SCP) has been widely used during complex congenital heart surgery and theoretically affords some degree of neuroprotection. There are limited data to support this claim, however. This study was designed to compare, at profound hypothermia, continuous cardiopulmonary bypass, SCP and circulatory arrest in a survival model of extracorporeal circulation in immature swine. Fifteen piglets (5.9+/-1.1 kg) were placed on cardiopulmonary bypass (CPB), cooled to a rectal temperature of 15 degrees C and subjected to 90 min of hypothermic circulatory arrest (HCA), selective cerebral perfusion (30 ml kg(-1)min(-1)) (SCP) or systemic full-flow perfusion (FF; 100 ml kg(-1)min(-1)). Piglets were weaned from CPB and extubated. Daily neurologic assessments were performed for 5 days using neurologic deficit scoring (NDS) and overall performance categories (OPC). On postoperative day (POD) 5, all brains were perfusion-fixed and assigned a total histologic score (THS) of neuronal injury by a neuropathologist blinded to the study groups. The median POD 1 NDS/OPC was 0 (range 0-115)/1(range 1-2) for FF, 130 (range 0-195)/2 (range 1-3) for HCA and 0 (range 0-30)/1 for SCP. Although there was a trend for the neurologic status in the HCA group to be worse on POD 1, this did not achieve significance, and both NDS and OPC scores for HCA animals normalised by POD 5. Median THS was 9 (range, 0-11) for FF, 12 (range, 4-14) for HCA and 9 (range, 0-11) for SCP with no statistically significant difference between the groups. In this survival model of hypothermic extracorporeal circulatory support in immature swine, histologic brain injury was similar in piglets subjected to FF, SCP or HCA. Although the HCA group tended to have worse early neurologic outcome, any difference clearly disappeared by POD 5. These data raise the possibility that profound hypothermia alone during extracorporeal support may produce this observed brain injury. Additional study is required to define the precise aetiology of the brain injury observed in this animal model.

Changes in matrix metalloproteinase (MMP) and tissue inhibitors of metalloproteinases (TIMP) expression profile in Crohn's disease after immunosuppressive treatment correlate with histological score and calprotectin values

Matrix metalloproteinases (MMPs) constitute a family of enzymes capable of degrading various extracellular matrices (ECM) and basement membrane components playing a role in ECM turnover. They activate and degrade signaling molecules, such as cytokines and chemokines. MMPs are involved in inflammation and have been implicated in tissue degradation and repair occurring in inflammatory bowel disease. The aim of this study was to investigate the MMP profile of intestinal Crohn's disease (CD) patients before and after immunosuppressive treatment (anti-TNF-alpha agents or corticosteroids and conventional immunosuppressants azathioprine or methotrexate) to learn more about the therapeutic pathways for immunosuppressive agents. Expression of MMP-1, MMP-7, MMP-9, MMP-10, and MMP-26 and tissue inhibitors of metalloproteinases (TIMP)-1 and TIMP-3 was studied by immunohistochemistry in pretreatment and post-treatment tissue samples. Semiquantitative immunohistochemical scores were tested for correlations with fecal and serum inflammation markers as well as endoscopic and clinical disease activity scores. Neutrophil MMP-9 (p = 0.039) and MMP-26 (p = 0.030) and stromal TIMP-1 (p = 0.041) and TIMP-3 (p = 0.029) decreased along with treatment. However, expression of TIMP-3 by enterocytes tended to increase. Total histological score demonstrated positive correlation with neutrophil MMP-9 (p = 0.000), MMP-26 (p = 0.014), and macrophage TIMP-1 (p = 0.001). Calprotectin followed a similar pattern with stromal MMP-26 (p = 0.011), TIMP-1 (p = 0.000), and TIMP-3 (p = 0.001). Crohn's disease endoscopic index of severity (CDEIS) value correlated positively with macrophage TIMP-1 (p = 0.007) and stromal TIMP-3 (p = 0.005). Epithelial TIMP-3 presented with negative correlations with CDEIS (p = 0.006) and C-reactive protein values (p = 0.004). Our results suggest that immunosuppressive drugs modulate disease activity in CD by downregulation of MMP-9 and MMP-26 positive neutrophils and stromal TIMP-1 and TIMP-3.

Melatonin Modulates the Severity of Taurocholate-Induced Acute Pancreatitis in the Rat

The aim of this study was to investigate the effects of melatonin on serum amylase, tumor necrosis factor-alpha (TNF-alpha) and histological changes in rats with taurocholate-induced acute pancreatitis. Thirty male Wistar rats were randomly divided into three groups; group 1, group 2 and group 3 were enrolled as melatonin, control and sham groups, respectively (n = 10 per group). Acute pancreatitis was induced by 1 ml/kg body weight using 5% taurocholate injection into the biliopancreatic duct in groups 1 and 2 after clamping the hepatic duct. Those in group 1 received 50 mg/kg body weight melatonin by intraperitoneal (i.p.) injection. Group 2 received physiological saline i.p. at the same dose. Group 3 solely underwent laparotomy with cannulation of the biliopancreatic duct. Twenty-four hours after the intervention, the rats were killed, and serum samples were collected to measure amylase and TNF-alpha levels. Simultaneously, pancreatic tissues were removed, stained with hematoxylin-eosin and examined under a light microscope. Serum amylase and TNF-alpha levels were significantly lower in the melatonin group compared to the controls (P < 0.001). The total histological score, including edema, inflammation, perivascular infiltrate, acinar necrosis, fat necrosis and hemorrhage, was also significantly lower in the melatonin group as compared to the control (P < 0.0001). In conclusion, melatonin is potentially capable of reducing pancreatic damage by decreasing serum TNF-alpha levels in taurocholate-induced acute pancreatitis in rats. This result supports the idea that melatonin might be beneficial in ameliorating the severity of acute pancreatitis.

Transglutaminase 2 is a marker of chondrocyte hypertrophy and osteoarthritis severity in the Hartley guinea pig model of knee OA

The transglutaminase (TG) isoenzyme TG2, which catalyzes protein cross-linking via transamidation, influences healing phenotype in multiple forms of tissue injury. Moreover, TG2 knockout suppresses cartilage destruction but promotes osteophyte formation in instability-induced mouse knee osteoarthritis (OA). TG2 is marker of growth plate chondrocyte hypertrophy. Moreover, TG2 secreted by chondrocytes acts in part by promoting chondrocyte maturation to hypertrophy, a differentiation state linked with MMP-13 expression and disease progression in OA. Moreover, glucosamine, which is currently under investigation as an OA therapy, binds and inhibits TG2. Here, we examined TG2 as a potential marker of cartilage hypertrophy in the spontaneous guinea pig model of OA. Synovial fluid ELISA and cartilage Immunohistochemistry and quantitative Reverse transcription-polymerase chain reaction (RT-PCR), were used to examine TG2 expression and TG transamidation-catalyzed isopeptide bonds. TG isopeptide bonds and TG2 were most abundant in articular cartilage in early knee OA. TG2 expression was robust at sites of early but not established osteophytes. Synovial fluid TG2 correlated with knee OA total histological score (r=0.47, P=0.01), as did medial tibial plateau cartilage TG2 mRNA (r=1.0, P=0.003). At 12 months of age, medial tibial plateau cartilage TG2 mRNA expression rose markedly in association with elevated type X collagen, as well as ADAMTS-5, and MMP-13 expression, changes not shared in age-matched Strain 13 guinea pigs that are less susceptible to knee OA. Hartley guinea pig knee TG2 expression associates with enhanced articular chondrocyte hypertrophy and is a biomarker of OA severity.

Renal Artery Stenosis and Renal Parenchymal Damage in Patients with Abdominal Aortic Aneurysm Proven by Autopsy

Background: Chronic kidney disease is a major risk factor for patients with cardiovascular diseases (CVD). The aim of this study is to evaluate the relationship between clinical characteristics and renal histology in patients with abdominal aortic aneurysm (AAA). Methods: We studied 79 cases with AAA autopsied at the National Cardiovascular Center. They were classified into two groups: 14 subjects with renal artery stenosis (RAS) (group A) and 65 subjects without RAS (group B). Proteinuria, elevated serum creatinine and decreased estimated glomerular filtration rate had been recorded. We evaluated renal parenchymal damage using a semiquantitative histological score (score 0–3; normal to severe) for glomerulosclerosis, interstitial fibrosis, tubular atrophy, and arteriolar hyalinosis (maximal score = 12). Results: Total histological score was 8.2 ± 2.4 and significantly higher in the stenosed kidneys of group A than in the non-stenosed kidneys of group B (8.9 ± 2.6 vs. 8.0 ± 2.3). The histological score had a significant association with RAS, smoking, kidney function, proteinuria, kidney weight and the presence of other CVD. Conclusion: We demonstrated that renal parenchymal damage and deteriorated kidney function are closely associated in the patients with AAA. Treatment of these patients in view of protection of the kidney is thus relevant.

Partially Hydrolyzed Guar Gum Attenuates the Severity of Pouchitis in a Rat Model of Ileal J Pouch-Anal Anastomosis

We aimed to evaluate the efficacy of treatment with partially hydrolyzed guar gum (PHGG) using a rat model of ileal pouch-anal anastomosis and pouchitis. In the J pouch groups, tissue myeloperoxidase activities were significantly higher than native myeloperoxidase activities (P = 0.020; P = 0.015; P = 0.004, respectively). A statistically significant difference in total histological score was detected in the J pouch + 5% dextran sulfate sodium (DSS) group, compared to the J pouch control and the J pouch + 5% DSS + PHGG groups (P < 0.01 and P < 0.01, respectively). There was a significant overgrowth of aerobes and anaerobes in the J pouch + 5% DSS group. This study demonstrated that rectal administration of PHGG attenuates the severity of pouchitis in a rat model. In conclusion, PHGG may be an additional therapeutic strategy for the treatment of pouchitis.

Diuretic Renography in Hydronephrosis: Delayed Tissue Tracer Transit Accompanies Both Functional Decline and Tissue Reorganization

The significance of delayed tissue tracer transit (TTT) of (99m)Tc-mercaptoacetyltriglycine ((99m)Tc-MAG3) has not been systematically evaluated in hydronephrosis. We sought to demonstrate that delayed TTT accompanies both functional decline and histomorphologic restructuring. Twenty 2- to 3-mo-old piglets with surgically induced partial unilateral ureteral stenosis were examined with magnetic resonance urography (MRU) to evaluate morphology and with (99m)Tc-MAG3 diuretic renography (DR) to determine single-kidney function (SKF), evaluate the response to furosemide stimulation (RFS), and assess TTT. All animals had DR and MRU before and after surgery and a third DR after surgery. Piglets were sacrificed after the final DR for renal histology. A total histologic score (THS) was generated. Preoperative DR demonstrated nonobstructive RFS, timely TTT, and balanced SKF in all 20 kidneys. After ureteral ligature, MRU demonstrated pelvic dilatation in all piglets. The postoperative DRs revealed 12 kidneys with delayed TTT in one or both follow-ups. In these 12 kidneys, the SKF declined from 51% +/- 4% to 18% +/- 14%, and the THS was 9.0 +/- 4.0. Three kidneys always had timely TTT, balanced SKF, and a THS of 1.8 +/- 0.3. The contralateral, nonoperated kidneys had timely TTT and a THS of 1.2 +/- 0.9. Postoperative scintigrams showed that 3 of 8 kidneys (38%) with an obstructive RFS had timely TTT, which demonstrates that TTT and RFS are not equivalent. In hydronephrosis, a delayed TTT of (99m)Tc-MAG3 accompanies both functional decline and histomorphologic restructuring in obstruction. According to the literature, a delayed TTT is determined by the filtration fraction of the kidneys and appears to identify an obstruction-mediated upregulated renin-angiotensin system.

Hepatitis B core antigen expression pattern predicts response to lamivudine therapy in patients with chronic hepatitis B

Negative hepatitis B core antigen (HBcAg) staining in hepatocytes is indicative of viral replication by an active immune response. HBcAg is expressed mainly in the cytoplasm in patients with active hepatitis and hepatocyte regeneration, and mainly in the nuclei of hepatocytes in patients with minimal liver injury in the absence of hepatocyte regeneration. The aim of this study was to elucidate whether the existence and expression pattern of HBcAg predicts the response to antiviral treatment. The study involved 58 patients with biopsy-proven chronic hepatitis B who were treated with lamivudine. Hepatitis B e antigen (HBeAg), antibody to HBeAg, hepatitis B virus DNA, and alanine aminotransferase in serum were recorded every 3 months. The inflammation grade and the fibrosis stage of chronic hepatitis were scored from 0 to 4 according to lobular inflammation, portal inflammation, periportal inflammation, and fibrosis. The 58 patients included 49(84%) HBcAg-positive patients, with HBcAg staining confined to the cytoplasm in 15(31%) and in both cytoplasm and nuclei in 34(69%). The grade of lobular inflammation and the total histology score were significantly higher in patients with cytoplasmic expression of HBcAg than in HBcAg-negative patients (lobular inflammation: 2.9 vs 2.1, P=0.02; total histology score: 12.2 vs 10.3, P=0.04). The virologic responses at 3, 6, 9, and 12 months differed significantly between the cytoplasmic and mixed expression groups (P<0.01). The expression pattern of HBcAg (including its possible absence) before initial therapy appears to predict the response to antiviral treatment.

Acute protective effects of different doses of simvastatin in the rat model of renal ischemia-reperfusion injury

It was previously shown that acute pretreatment with simvastatin (1 mg/kg) significantly protects rats from renal ischemia-reperfusion injury (I/R, 45 min + 4 h). The aim of our present study was to determine whether this beneficial effect of simvastatin was dose-related. A single dose of simvastatin of 1 or 3 mg/kg, i.v. bolus, dissolved in 10% DMSO (Sim1 and Sim3), was injected 30 min before ischemia, 30 min before reperfusion or 5 min before reperfusion (30I, 30R, and 5R, respectively). Simvastatin-treated rats were compared to the appropriate controls (I/R + DMSO and Sham + DMSO group). Sim1 and Sim3 groups were similar regarding serum concentrations of urea, creatinine, aspartate aminotransferase, and gamma-glutamiltransferase (sUr, sCre, ALT, and γGT, respectively), as well as total histological score. Both doses of the drug (Sim1 and Sim3) were more effective in the reduction of total histological score in comparison with I/R + DMSO group. Also, the higher dose of drug 3 mg/kg (Sim3) was somewhat more effective than Sim1 in the reduction of tubular necrosis score and loss of brush border. In conclusion, the acute protective effect of simvastatin in the experimental model of renal I/R injury does not seem to be dose-related, and the dose of 1 mg/kg should be chosen for further investigation.

Comparison of radiofrequency treatment and mechanical debridement of fibrillated cartilage in an equine model

To compare a radiofrequency energy (RFE) prototype probe to mechanical debridement (MD) and a commercially available RFE system used for chondroplasty in the treatment of an experimentally created partial thickness cartilage lesion in horses. The study design was experimental, randomized complete block, n=8, using fifteen mature ponies. Grade 2 to 3 cartilage lesions were prepared in both patellae. After 10 months duration, the injuries were used to study the effects of MD, a commercially available bipolar RFE device (CoVac 50; ArthroCare Corporation) and a prototype monopolar RFE device (Smith & Nephew Endoscopy). Six months after treatment the patellae were examined for chondrocyte viability and cartilage structure. Mean depth of cell death was significantly different among groups (controls, MD <prototype<CoVac 50) (P<0.05). Total histologic scores did not demonstrate any significant differences among the controls, MD and prototype RFE groups, which were all better than the CoVac 50 scores (P<0.05). There was a trend for the prototype RFE probe treated regions to have better surface structural characteristics than MD (P=0.11). Cartilage thickness was greater for the prototype RFE group than all other groups, and was the thinnest for the CoVac 50 group (P<0.05). When thermal chondroplasty is performed with a power-controlled prototype RFE probe, there is a better surface smoothing effect compared to MD, which causes less chondrocyte death and has the potential to maintain thicker cartilage compared to the commercially available RFE system.