Assessment of intestinal and cardiac-related biomarkers in dogs with parvoviral enteritis.

The aim of this study was to evaluate the intestinal and cardiac biomarkers in the determination of intestinal and cardiac damage in dogs with parvoviral enteritis. The material of this study consisted of 10 healthy dogs (control group) and 30 dogs with parvoviral enteritis (experimental group) admitted to the Department of Internal Medicine, Faculty of Veterinary Medicine, Selcuk University.Serum samples were extracted from the collected blood samples taken from vena cephalicavenipuncture for analysis of blood gases, haemogram and to measure the levels of intestinal-fatty acid-binding protein (I-FABP), trefoil factor 3 (TFF-3), claudin-3 (CLDN-3), heart-type fatty acid-binding protein (H-FABP), cardiac troponin I (cTnI), and creatine kinase-myocardial band (CK-MB) by enzyme linked immunosorbent assay (ELISA) test kits. Statistically significant decreases in the blood gas hydrogen ion concentration (pH), partial pressure of oxygen (pO2), sodium (Na), bicarbonate (HCO3), and oxygen saturation (SatO2) levels and significant increase in the levels of I-FABP, TFF-3, CK-MB, cTnI and also in the haemogram, a decrease in leukocyte (WBC) level and an increase in platelet (THR) level were detected in parvoviral dogs compared to the control group (p⟨0.05). Also ROC analysis revealed on 0th hour for the utility of I-FABP and on 48th hour for TFF-3 in differentiating in the experimental group between the survivor and non-survivor dogs. Other intestinal-related biomarker (CLDN-3) and none of the cardiac-related biomarkers (H-FABP, CK-MB and cTnI) are not high enough for prediction of mortality.In conclusion, it was determined that I-FABP and TFF-3 for the intestinal injury and morta-lity prediction, and CK-MB and cTnI for the cardiac injury were useful and reliable biomarkers to determine the damage caused by parvovirus in dogs.

Ex Vivo Perfusion Characteristics of Donation After Cardiac Death Kidneys Predict Long-Term Graft Survival.

BACKGROUND: Ex vivo perfusion is used in our unit for kidneys donated after cardiac death (DCD). Perfusion flow index (PFI), resistance, and perfusate glutathione S-transferase (GST) can be measured to assess graft viability. We assessed whether measurements taken during perfusion could predict long-term outcome after transplantation. METHODS: All DCD kidney transplants performed from 2002 to 2014 were included in this study. The exclusion criteria were: incomplete data, kidneys not machine perfused, kidneys perfused in continuous mode, and dual transplantation. There were 155 kidney transplantations included in the final analysis. Demographic data, ischemia times, donor hypertension, graft function, survival and machine perfusion parameters after 3 hours were analyzed. Each perfusion parameter was divided into 3 groups as high, medium, and low. Estimated glomerular filtration rate was calculated at 12 months and then yearly after transplantation. RESULTS: There was a significant association between graft survival and PFI and GST (P values, .020 and .022, respectively). PFI was the only independent parameter to predict graft survival. CONCLUSIONS: A low PFI during ex vivo hypothermic perfusion is associated with inferior graft survival after DCD kidney transplantation. We propose that PFI is a measure of the health of the graft vasculature and that a low PFI indicates vascular disease and therefore predicts a worse long-term outcome.

Posttransplant Urinary Tract Infection Rates and Graft Outcome in Kidney Transplantation for End-Stage Renal Disease Due to Reflux Nephropathy Versus Chronic Glomerulonephritis.

BACKGROUND: The goal of this study was to evaluate posttransplant urinary tract infection (UTI) rates and graft outcome in kidney transplantation for end-stage renal disease (ESRD) due to vesicoureteral reflux (VUR)-related reflux nephropathy (RN) versus chronic glomerulonephritis (CGN). METHODS: A total of 62 patients with ESRD who underwent kidney transplantation for VUR-related RN (VUR-RN group, n = 31; mean ± standard deviation age, 34.1 ± 6.0 years; 58.1% female) or CGN (CGN group, n = 31; mean age, 34.2 ± 6.8 years; 71.0% male) at our unit between January 1996 and January 2011 were included in this retrospective study. Baseline recipient and donor characteristics, renal replacement therapy, posttransplant data on serum creatinine levels, graft outcome, and UTIs were recorded. Posttransplant UTIs and graft outcome were compared between the VUR-RN and CGN groups, as well as between patients with and without pretransplant nephrectomy in the VUR-RN group. RESULTS: The frequency of overall (72 vs 18 of 90; P = .05) UTI episodes was significantly higher in the VUR-RN group than in the CGN group; Escherichia coli (64.2%) was the most common pathogen. The VUR-RN and CGN groups were similar in terms of 1-year (100.0% for each), 5-year (95.8% vs 96.8%), and 10-year (82.0% vs 96.8%) graft survival. VUR-RN patients with and without nephrectomy were similar in terms of 1-year (100.0% for each), 5-year (91.7% vs 85.7%), and 10-year (81.5% vs 85.7%) graft survival. CONCLUSIONS: Our findings indicate kidney transplantation is a safe and effective option in ESRD patients with RN secondary to VUR. It resulted in high 1-year, 5-year, and 10-year graft survival rates.

Erratum:Preoperative neutrophil-to-lymphocyte ratio and platelet-to-lymphocyte ratio as new prognostic factors for patients with colorectal cancer.

In this article published in Volume 21, issue 5, the authors' names appeared in the Pubmed abstract as: "Mahsuni Sevinc M, Riza Gunduz U, Kinaci E, Armagan Aydin A, Bayrak S, Umar Gursu R, Gunduz S". The correct authors' names are: "Sevinc MM, Gunduz UR, Kinaci E, Aydin AA, Bayrak S, Gursu RU, Gunduz S" This error appeared only in the PubMed database and not in the print form of the Journal.

Carcinoid tumor of the cecum presenting with acute appendicitis: a case report.

BACKGROUND: Acute appendicitis is the most common cause of acute abdomen. Carcinoid tumor of the appendix is a rare incidental finding that can present with the clinical picture of acute appendicitis. CASE REPORT: During open surgery for acute appendicitis, a 3 cm solid mass, not noticed externally, was palpated at the base of the appendix. The mass and the appendix were excised by en-bloc wedge resection. The histopathological examination of the lesion revealed carcinoid tumor. CONCLUSION: The aim of this presentation is to remind that neoplasms of the appendix may, although rarely, present the clinical picture of acute appendicitis, and to highlight that they, particularly those located at the base of the appendix and in cecum, may be overlooked during laparoscopy. The importance of preoperative computerized tomography ins uch cases has to be underlined.

Renal Damage Frequency in Patients with Solitary Kidney and Factors That Affect Progression.

Background. The aim of this study is to assess renal damage incidence in patients with solitary kidney and to detect factors associated with progression. Methods. Medical records of 75 patients with solitary kidney were investigated retrospectively and divided into two groups: unilateral nephrectomy (group 1) and unilateral renal agenesis/dysplasia (group 2). According to the presence of kidney damage, each group was divided into two subgroups: group 1a/b and group 2a/b. Results. Patients in group 1 were older than those in group 2 (p = 0.001). 34 patients who comprise group 1a had smaller kidney size (p = 0.002) and higher uric acid levels (p = 0.028) than those in group 1b at presentation. Uric acid levels at first and last visit were associated with renal damage progression (p = 0.004, 0.019). 18 patients who comprise group 2a were compared with those in group 2b in terms of presence of DM (p = 0.038), HT (p = 0.003), baseline proteinuria (p = 0.014), and uric acid (p = 0.032) levels and group 2a showed higher rates for each. Progression was more common in patients with DM (p = 0.039), HT (p = 0.003), higher initial and final visit proteinuria (p = 0.014, for both), and higher baseline uric acid levels (p = 0.047). Conclusions. The majority of patients with solitary kidney showed renal damage at presentation. Increased uric acid level is a risk factor for renal damage and progression. For early diagnosis of renal damage and reducing the risk of progression, patients should be referred to a nephrologist as early as possible.

Isolation, expression and characterization of a minor allergen from Penicillium crustosum.

A ribosomal P1 protein, Pen b 26 from Penicillium brevicompactum, was previously identified as a major allergen. A homolog protein was isolated and characterized from Penicillium crustosum which is not known to be allergenic mold. A cDNA library of P. crustosum was constructed and screened using a probe based on the DNA sequence of Pen b 26. A positive clone was isolated, expressed in Escherichia coli, purified and characterized by comparing its immunological and physical properties to Pen b 26. It was designated as Pen cr 26 and had a 321 nt ORF corresponding to 107 amino acids with a MW of 11 kDa. Pen cr 26 had strong sequence homology to Pen b 26 (92% for nucleotides and 86% for amino acids) and its physical and predicted structural properties were similar to the latter. The level of expression of Pen cr 26 was much lower than that of Pen b 26 in the same expression vector. Both proteins were recognized equally well by the IgG class specific antibodies, but Pen cr 26 was poorly recognized by Penicillium-sensitive atopic sera (IgE), suggesting striking antigenic difference in IgE epitopes, i.e., 87% were positive for Pen b 26 while only 23% were positive for Pen cr 26. The allergenicity of Pen cr 26 seems to be minor in nature and it could be a hypoallergenic variant of Pen b 26.

Effects of infectious complications on patients' survival in peritoneal dialysis.

AIM: To investigate the impacts of infectious complications on mortality and morbidity; and to identify the other potential factors effective in mortality in peritoneal dialysis (PD) patients. PATIENTS AND METHODS: We included patients who initiated therapy between 2001-2011. Patients were divided into two groups regarding to presence or absence of infectious complications. Socio-demographic data and clinical courses were compared and the reasons for PD withdrawal were obtained. Survival analysis of all patients was performed and the effects of infectious complications on mortality were investigated. RESULTS: 301 patients were included in this retrospective study. 214 patients (mean follow-up time 28.7±16.5 months) had infection history, 87 patients (mean follow-up time 48.9±29.6 months) had no infection history. There were no statistically significant difference in comparison of the groups in terms age, gender, education levels, hemodialysis history. In patients with infection history, 465 peritonitis and 213 catheter exit site infection attacks were diagnosed. The most frequently agent was methicillin-sensitive Staphylococcus aureus and Methicillin-resistant Staphylococcus aureus in both conditions, while 25% of catheter exit site infection and 25% of peritonitis attacks were culture negative. During follow-up period, 60 patients transferred to hemodialysis, 58 patients died, 18 patients had renal transplantation in patients with infection history. In other group, 27 patients died, 23 patients had renal transplantation and 11 patients transferred to hemodialysis. Mean survival times were 56.3±2.8 months in patients with infection history and 86.8±6.1 months in other group. Mortality rate was found higher in patients with infection history (long-rank: 0.030). PD preference (OR: 5.213, p < 0.001), pretreatment low serum albumin (OR: 0.378, p = 0.001), low hemoglobin levels (OR: 0.810, p = 0.029) were found as predictors of survival in patients with infection history. CONCLUSIONS: Infectious complications have negative effects on patient survival. Nature of PD preference, initial hypoalbuminemia and anemia were found to increase the mortality rate. The major causes of deaths were peritonitis and/or sepsis in patients with infectious complications, while the major cause of death was cardiac reasons in patients without infectious complications.

Fungal peritonitis in peritoneal dialysis: a 10 year retrospective analysis in a single center.

INTRODUCTION: Fungal peritonitis (FP) is a rare but serious complication in patients undergoing peritoneal dialysis (PD), and is associated with higher morbidity, mortality. We aimed to analyze the predisposing factors, etiological agents, outcome and treatment of FP in patients with PD. METHODOLOGY: We evaluated retrospectively all PD patients PD center between 2001 and 2011. Sixteen patients with FP were included into the study. RESULTS: The clinical records of 16 patients with FP among 355 patients were reviewed for the clinical and laboratory data. Among 506 episodes of PD-related peritonitis in 10 years, we identified 16 episodes of FP. Median PD duration was 36.7±22.2 months. In 87.5% of patients had one or more previous episode of bacterial peritonitis that were treated with multiple broad-spectrum antibiotics. FP was primary infection in five patients, whereas eleven patients experienced FP during the course of treatment of bacterial peritonitis. Six patients died due to the fungal infection whereas others were transferred to haemodialysis. CONCLUSIONS: Treatment of bacterial peritonitis with broad spectrum antibiotics was an important risk factor predisposing to the development of FP. The catheter removal and initiation of antifungal therapy as soon as possible are obligatory in episode of FP because it is responsible from high mortality rate.

Scar endometriosis in the abdominal wall: a predictable condition for experienced surgeons.

PURPOSE: Endometriosis in surgical scars develops in 0.1% of those women who undergo Caesarean section or other obstetric surgery. Herein we analyse and discuss the clinico-pathological characteristics of 15 patients with scar endometriosis in the abdominal wall. METHODS: Fifteen cases of scar endometriosis in the abdominal wall that were treated surgically in our department between 2003 and 2009 were examined retrospectively. Age, parity, complaint, medical or surgical history, pre/postoperative hormonotherapy, size of the mass, surgical procedure, follow-up and disease recurrence were analysed. RESULTS: This retrospective study included 15 patients presenting with 17 postoperative abdominal wall masses. The mean age of the patients was 32.1 +/- 6.0 years (range, 23-48). Eleven of the patients had a painful mass that became bigger before menstruation, two had palpable masses only, and two were hospitalised because of a mass with persistent pain. The locations of the masses were as follows: eight were close to the right side and three were close to the left side; two were in the middle of the Pfanenstiel incision and two were in trocar tracts. The patients' surgical histories included Caesarean section in thirteen, bilateral laparoscopic ovarian cyst excision in one, and laparoscopic appendectomy in one. CONCLUSIONS: If a patient presents with incision pain and a palpable mass after gynaecologic surgery, an incisional endometrioma should be considered. Surgical excision and hormone therapy are effective treatment approaches in these patients.

Multiple intestinal intussusceptions in Peutz-Jeghers' syndrome: a case report.

Peutz-Jeghers' syndrome (PJS) is an autosomal dominant inherited disease, which is characterized by mucocutaneus pigmentation and hamartomatous gastro-intestinal polyps. Intussusceptions can easily occur in patients with PJS. Repeated laparotomy with resections and eventual short bowel syndrome is a major problem in these patients. We present a 20-year-old woman with multiple intestinal intussusceptions. Multiple enterotomies and intestinal resections were performed to achieve a longer symptom-free period.

Expression and characterization of Pen b 26 allergen of Penicillium brevicompactum in Escherichia coli.

Pen b 26 is one of the allergens produced by Penicillium brevicompactum which is one of the most prevalent in door airborne fungi and a major source of respiratory problems, including asthma. Pen b 26 wa scloned and expressed as an N-terminal as well as a C-terminal His6 tagged fusion protein in Escherichia coli. This allergen was purified by immobilized Ni2+-affinity chromatography. The purified Pen b 26 was characterized by immunological, biochemical and biophysical methods. C-His6 tagged Pen b 26 produced several fold greater yield than N-His6 tagged Pen b 26. The affinity of C-His6 tagged Pen b 26 for the specific antibody was also 2.75 times higher than N-His6 tagged Pen b 26

Effectivity of qualitative urinary trypsinogen-2 measurement in the diagnosis of acute pancreatitis: a randomized, clinical study.

BACKGROUND: There is no any definite diagnostic test for acute pancreatitis. In the present study we investigated the value of the qualitative urinary trypsinogen-2 measurement in the diagnosis of acute pancreatitis by an immuno-chromatographic dipstick test. METHODS: A prospective, randomized, clinical trial was planned on 99 patients (53 male, 46 female; male/female : 1.11; age range: 16-83; mean age: 37.4). Patients were divided into two groups: 50 cases were referred to our emergency surgical unit due to abdominal pain and diagnosed with acute pancreatitis by abdominal computerized tomography (CT) (Group 1); 49 cases were referred to our emergency surgical unit due to abdominal pain and whose abdominal CTs did not show any sign of acute pancreatitis (Group 2). Qualitative urinary trypsinogen-2 measurement, abdominal CT and blood amylase values were obtained in all cases. RESULTS: In group 1, urinary trypsinogen-2 measurement was found positive in 28 cases out of 50 cases diagnosed with acute pancreatitis (56% sensitivity). In group 2, results were found positive in 3 out of 49 patients with abdominal pain, who lacked an acute pancreatitis diagnosis (90.9% specificity). Severe intra-abdominal inflammation was present in three cases of group 2 where we obtained false positive results which may stimulate the pancreatic exocrine secretion. CONCLUSION: Qualitative measurements of urinary trypsinogen-2 in patients with abdominal pain may be useful in the diagnosis of acute pancreatitis. It is an easy, inexpensive, rapid and noninvasive method.

Isolation and characterization of a cDNA clone encoding one IgE-binding fragment of Penicillium brevicompactum.

BACKGROUND: The abundance of allergenic Penicillium species has been associated with an increased incidence of childhood asthma and pulmonary bleeding. Penicillium brevicompactum has been identified as the most prevalent indoor species of this genus. However, detailed studies on the allergens of the ubiquitous Penicillium species are still lacking. For the characterization of allergens of prevalent Penicillium species, molecular cloning of the allergen genes of P. brevicompactum was performed in the present study. METHODS: A phage cDNA library of P. brevicompactum was constructed in Uni-ZAP XR vector using mRNA isolated from the organism. The cDNA library of P. brevicompactum was screened using pooled atopic sera. RESULTS: Screening of P. brevicompactum cDNA library resulted in one positive clone encoding an estimated molecular weight of 11 kDa polypeptide, rich in acidic residues (>20%), with a pI of 3.87. This clone was designated as Pen b 26 and found to be reactive only against the atopic sera obtained from individuals sensitive to P. brevicompactum. The amino acid sequence analysis of Pen b 26 revealed that it had strong homology to the 60S acidic ribosomal protein P1 family from different eukaryotic sources, predominantly fungal aero-allergens. Other features of Pen b 26 including having high alpha-helical content (>50%), alanine-rich residues (>20%), and a well-conserved C-terminal epitope region fits well into the common properties of 60S acidic ribosomal proteins. CONCLUSIONS: The results obtained suggest that the allergenic clone, Pen b 26 is a 60S acidic ribosomal protein P1 of P. brevicompactum and shows strong similarity to other P1 family proteins.

Efficacy of local adrenalin injection during sacrococcygeal pilonidal sinus excision.

BACKGROUND: The most commonly preferred treatment method for sacrococcygeal pilonidal sinus disease is surgery. Peroperative and postoperative hemorrhages may develop frequently because of the increased vascularity of the region. The aim of this study was to evaluate the effects of adrenalin, a potent vasoconstrictor agent, on pilonidal sinus operations in comparison to a control group. METHODS: A prospective, randomized, double-blind, clinical study was designed and 51 patients with symptomatic, uncomplicated pilonidal disease were included (44 males and 7 females; mean age 24.5, range 16-44 years). Adrenalin 0.1 mg with 10 ml 0.9% NaCl (1/100,000 dilution) was injected through the incision tracts to all layers and the base of the incision area in group 1 (n = 21). The same process was applied to group 2 (n = 21) with 10 ml physiological serum solution. Then, after removal of the sinus and its tracks, a suction-type drain was placed in the pouch in all cases and the incision was primarily closed. Peroperative and postoperative hemorrhage, and operation time were accepted as the evaluation criteria. Cases were followed for 6 months postoperatively. RESULTS: The amount of peroperative hemorrhage was 6.5 +/- 3.5 ml in group 1 and 17.5 +/- 9.5 ml in group 2 (p < 0.001). The postoperative hemorrhage was 11 +/- 7.5 ml in group 1 and 13.5 +/- 6 ml in group 2 (p > 0.05). The operation time was 14 +/- 5 min in group 1 and 22 +/- 8.5 min in group 2 (p < 0.05). No reactionary hemorrhage, hematoma or recurrence was seen during the follow-up period. CONCLUSIONS: Adrenalin injection is quite effective to decrease peroperative bleeding and operation time, but it does not decrease postoperative bleeding and the need for a drain.

Prognostic significance of microvascular invasion in localized renal cell carcinoma.

OBJECTIVES: The treatment of localized and even advanced renal cell carcinoma (RCC) is radical nephrectomy. However, 30% of these patients progress after radical nephrectomy. Prognostic factors are needed in order to determine the course of disease in patients undergoing radical nephrectomy. The aim of this study is to study the prognostic significance of microvascular invasion (MVI) in patients who had undergone radical nephrectomy for localized RCC. METHODS: Between June 1989 and February 1999, pathologic sections of the specimens from 41 patients without metastases, nodal involvement or macroscopic venous involvement were investigated for MVI. RESULTS: MVI was observed in 17% of the patients. MVI was related to the grade of the tumor and tumor size (p = 0.032, p = 0.017). In sarcomatoid-type RCC, MVI was more common than in other histologic types (p = 0.003). After a median follow-up of 48 months, the progression rate was 29% in patients with MVI and 17% without MVI (p = 0.001). Median progression time was 3 months in those with MVI and 41 months with no MVI (p = 0.01). The survival rate decreased from 85 to 70% in patients with MVI during a median follow-up of 48 months (p = 0.031). In multivariate analysis, MVI was not found to be an independent prognostic factor. CONCLUSION: Although MVI is closely related to progression and prognosis, in multivariate analysis it was not found to be an independent prognostic factor in localized RCC. We conclude that MVI should also be evaluated together with tumor grade in predicting the prognosis of patients with localized RCC.

Mutants that alter the covalent structure of catalase hydroperoxidase II from Escherichia coli.

The three-dimensional structures of two HPII variants, V169C and H392Q, have been determined at resolutions of 1.8 and 2.1 A, respectively. The V169C variant contains a new type of covalent bond between the sulfur atom of Cys(169) and a carbon atom on the imidazole ring of the essential His(128). This variant enzyme has only residual catalytic activity and contains heme b. The chain of water molecules visible in the main channel may reflect the organization of the hydrogen peroxide substrates in the active enzyme. Two alternative mechanisms, involving either compound I or free radical intermediates, are presented to explain the formation of the Cys-His covalent bond. The H392Q and H392E variants exhibit 75 and 25% of native catalytic activity, respectively. The Gln(392) variant contains only heme b, whereas the Glu(392) variant contains a mixture of heme b and cis and trans isomers of heme d, suggesting of a role for this residue in heme conversion. Replacement of either Gln(419) and Ser(414), both of which interact with the heme, affected the cis:trans ratio of spirolactone heme d. Implications for the heme oxidation mechanism and the His-Tyr bond formation in HPII are considered.

Role of the lateral channel in catalase HPII of Escherichia coli.

The heme-containing catalase HPII of Escherichia coli consists of a homotetramer in which each subunit contains a core region with the highly conserved catalase tertiary structure, to which are appended N- and C-terminal extensions making it the largest known catalase. HPII does not bind NADPH, a cofactor often found in catalases. In HPII, residues 585-590 of the C-terminal extension protrude into the pocket corresponding to the NADPH binding site in the bovine liver catalase. Despite this difference, residues that define the NADPH pocket in the bovine enzyme appear to be well preserved in HPII. Only two residues that interact ionically with NADPH in the bovine enzyme (Asp212 and His304) differ in HPII (Glu270 and Glu362), but their mutation to the bovine sequence did not promote nucleotide binding. The active-site heme groups are deeply buried inside the molecular structure requiring the movement of substrate and products through long channels. One potential channel is about 30 A in length, approaches the heme active site laterally, and is structurally related to the branched channel associated with the NADPH binding pocket in catalases that bind the dinucleotide. In HPII, the upper branch of this channel is interrupted by the presence of Arg260 ionically bound to Glu270. When Arg260 is replaced by alanine, there is a threefold increase in the catalytic activity of the enzyme. Inhibitors of HPII, including azide, cyanide, various sulfhydryl reagents, and alkylhydroxylamine derivatives, are effective at lower concentration on the Ala260 mutant enzyme compared to the wild-type enzyme. The crystal structure of the Ala260 mutant variant of HPII, determined at 2.3 A resolution, revealed a number of local structural changes resulting in the opening of a second branch in the lateral channel, which appears to be used by inhibitors for access to the active site, either as an inlet channel for substrate or an exhaust channel for reaction products.

Truncation and heme pocket mutations reduce production of functional catalase HPII in Escherichia coli.

The subunit of catalase HPII from Escherichia coli is 753 residues in length and contains a core of approximately 500 residues, with high structural similarity to all other heme catalases. To this core are added extensions of approximately 80 and 180 residues at the N- and C-termini, respectively. The tetrameric structure is made up of a pair of interwoven dimers in which 90 N-terminal residues of each subunit are inserted through a loop formed by the hinge region linking the beta-barrel and alpha-helical domains of the adjacent subunit. A high concentration of proline residues is found in the vicinity of the overlap regions. To study the influence of the extended regions on folding and subunit association of HPII, a diversity of modifications have been introduced. Removal of the complete C-terminal domain or the N-terminal extension, either separately or together, effectively creating a small subunit catalase, resulted in no enzyme accumulation. Systematic truncations showed that only nine C-terminal residues (Ile745 to Ala753) could be removed without significantly affecting the accumulation of active enzyme. Removal or even conservative replacements of the side chain of Arg744 significantly reduced the accumulation of active enzyme despite this residue interacting only with the C-terminal domain. Removal of as few as 18 residues from the N-terminus also reduced accumulation of active enzyme. Changes to other residues in the protein, including residues in the heme binding pocket, also reduced the accumulation of active protein without substantially affecting the enzyme specific activity. Implications of these data for the interdependence of subunit folding and subunit-subunit interactions are discussed.

Is magnetic resonance imaging necessary in the staging of prostate cancer?

OBJECTIVE: To evaluate the necessity of using magnetic resonance imaging (MRI) in the staging of patients with clinically localized prostate cancer. METHODS: Sixty-one patients with prostate cancer were evaluated with MRI for preoperative staging with a conventional body-coil (Siemens Magnetom, 1.0 Tesla superconducting system). Twenty-nine patients underwent radical prostatectomy for presumed clinically localized disease. Of those, 17 were staged both with MRI and computerized tomography (CT). The remaining patients were staged with CT alone. MRI and CT findings, and the final pathologic staging of patients are reviewed. RESULTS: On pathological examination of the surgical specimens, the tumor was found to extend beyond the prostate in 7 patients (41%). Among the 17 patients who were operated, extraprostatic extension (EPE) was detected accurately in 3 patients with MRI (sensitivity 20%, specificity 92%, accuracy 70. 5%). No metastatic lymph nodes were detected on the basis of MRI (sensitivity 0%, specificity 93%, accuracy 88.2%). In 1 patient EPE was correctly identified by CT (sensitivity 14%, specificity 100%, accuracy 64.7%). CONCLUSION: Neither MRI with conventional body-coild nor CT are sufficient to indicate local extension of disease in clinically localized prostate cancer.