Genome-wide loss of heterozygosity analysis of chemically induced rat hepatocellular carcinomas reveals elevated frequency of allelic imbalances on chromosomes 1, 6, 8, 11, 15, 17, and 20

Neoplastic development is a multistep process that involves the stochastic accumulation of heritable genetic alterations in proto-oncogenes, DNA repair genes, and tumor suppressor genes. Loss of heterozygosity (LOH) analysis has been used successfully to identify the genetic determinants of neoplastic development, including tumor suppressor genes, in several species and organs but not in the rat liver. We report the results of a sensitive genome-wide LOH analysis of rat hepatocellular carcinomas (HCCs). Heterozygous rats (Wistar-Furth x Fisher 344) were subjected to an Initiation-Promotion-Progression (IPP) protocol of hepatocarcinogenesis. Two weeks after initiation (by partial hepatectomy, 10 mg/kg diethylnitrosamine), the rats were placed on a diet containing 0.05% phenobarbital (PB). After 24 wk of PB promotion, the rats received either 100 or 1 50 mg/kg ethylnitrosourea. Hepatocellular tumors were resected after a total of 76wk of PB promotion. LOH analysis was completed on 26 HCCs by using 60 microsatellite markers covering all 20 rat autosomes and chromosome X. While 85% of the HCCs had one or more allelic imbalances, the average HCC had 3.3 allelic imbalances (range 0-9). A conditional hypothesis-testing method called the Hot-Cold model was used to determine the location of statistically significant elevations in the frequency of allelic imbalances. Elevated allelic imbalances were observed on chromosomes 1q, 6, 8, 11, 15, 17, and 20p. Together, these allelic imbalances suggest that the retinoblastoma and insulin-like growth factor genes as well as the resistance to chemical carcinogenesis (rcc) locus may be involved in HCC development in the rat but that LOH of the p53 gene is not. The elevated rate of allelic imbalances on chromosomes 8,11, and 17 may indicate the location of undiscovered tumor suppressor genes important to neoplastic development in rat liver. Microdissection-based LOH analysis of HCC revealed that contamination of non-neoplastic and nonhepatocellular tissue was not masking LOH in the whole-tumor analysis. There were no statistically significant differences in the frequency of allelic imbalances between HCC of any differentiation state (histological grade). To the degree that it does not reflect differences in etiological factors, the absence of allelic imbalances in chromosomal regions containing the p53 and mamose-6-phosphate/insulin-like growth factor II receptor tumor suppressor genes and the generally low frequency of allelic imbalances in these tumors, suggests that LOH and allelic imbalances play a less significant role in the molecular pathogenesis of HCC in rats than humans.     

Usefulness of distraction osteogenesis in the treatment of knee arthrosis]

AIMS: The purpose of this study is the assessment of efficiency of distraction osteogenesis (DO) as a method of operative treatment of knee arthrosis with co-existent varus deformity. MATERIAL AND METHODS: Authors undertook an attempt of evaluation of results of tibial corticotomy in 21 patients (25 operated knee joints) treated in Orthopaedic Clinic of Wroclaw Medical University in years 1995-2001, with the use of circular, external Ilizarov's fixator. All the operated patients underwent corticotomy of proximal tibial metaphysis followed by slow axis correction and bone regenerate formation started at 7th postoperative day. In orthopaedic examination functional evaluation of knee joint with modified point scale according to Ranawat (HSS-score) there were taken into account. In rentgenometric examination the limbs axis in the frontal plane and joint space morphology according to Ahlback were evaluated. RESULTS: The results in our group of patients were very encouraging. Accordingly to Ranawat scale, in majority of patients assessed before the treatment as poor and fair moved to group assessed as fair and good and even excellent. We observed decelerated regenerate formation and remodeling probably caused by advanced age of patients in 6 cases. In 3 cases persistent lose of entire correction was observed. CONCLUSIONS: In author's opinion DO as a method of operative treatment of unicompartmental knee arthrosis could be advocated as alternative method to traditional tibial osteotomy considering its biological effect stimulating regeneration of all tissues including cartilage even in advanced unicompartmental arthrosis.     

Is mechanical bowel preparation mandatory for elective colon surgery? A prospective randomized study

BACKGROUND: Bowel preparation prior to colonic surgery usually includes antibiotic therapy together with mechanical bowel preparation (MBP). Mechanical bowel preparation may cause discomfort to the patient, prolonged hospitalization, and water and electrolyte imbalance. It was assumed that with the improvement in surgical technique together with the use of more effective prophylactic antibiotics, it was possible that MBP would no longer be necessary. HYPOTHESIS: There is no statistical difference in the postoperative results of patients who undergo elective colon resection with MBP as compared with those who have no MBP.Design and PATIENTS: The study includes all patients who had elective large bowel resection at Campus Golda between April 1, 1999, and March 31, 2002. Emergency operations were not included. The patients were randomly assigned to the 2 study groups (with or without MBP) according to identification numbers. All patients were treated with intravenous and oral antibiotics prior to surgery. The patients in the MBP group received Soffodex for bowel preparation. RESULTS: A total of 329 patients participated in the study, 165 without MBP and 164 with MBP. The 2 groups were similar in age, sex, and type of surgical procedure. Two hundred sixty-eight patients (81.5%) underwent surgery owing to colorectal cancer and 61 patients (18.5%) owing to benign disease. The hospitalization period was longer in the bowel-prepared group (mean +/- SD, 8.2 +/- 5.1 days) as compared with the nonprepared group (mean +/- SD, 8.0 +/- 2.7 days). However, this difference was not statistically significant. The time until the first bowel movement was similar between the 2 groups: a mean +/- SD of 4.2 +/- 1.3 days in the nonprepared group as compared with a mean +/- SD of 4.3 +/- 1.1 days in the prepared group (P = NS). Four patients (1.2%) died in the postoperative course owing to acute myocardial infarction and pulmonary embolism. Sixty-two patients (37.6%) of the non-MBP group suffered from postoperative complications as compared with 77 patients (46.9%) of the MBP group. CONCLUSION: Our results suggest that no advantage is gained by preoperative MBP in elective colorectal surgery.     

Increased activity of Pgp multidrug transporter in patients with Helicobacter pylori infection

AIM: To determine whether local antibiotic resistance involves P-glycoprotein (Pgp)-mediated active drug out-pumping during Helicobacter pylori (H pylori) infection treatment with classic antibiotic therapy. METHODS: Pgp activity was determined in gastric mucosa biopsy specimens obtained from 53 patients with pathohistologically verified gastritis and microbiologically confirmed H pylori infection, and compared with the Pgp activity in 12 control subjects with normal endoscopic findings. The H pylori positive patients were treated with short-term 7-d therapy consisting of two antibiotics (amoxicillin and azithromycin/metronidazole and clarithromycin) and a proton pump inhibitor. Pgp activity was determined by flow cytometry in the test of rhodamine dye efflux and quantified as mean fluorescence ratio (RMF). RESULTS: Upon the first cycle, H pylori was successfully eradicated in 20 patients, whereas therapy was continued in 33 patients. In the course of antibiotic therapy, RMF increased (P＜0.05) and gastric cells showed higher rhodamine dye efflux. The mean pre-treatment RMF values were also higher (P＜0.0001) in patients with multiple therapeutic failure than in those with successful H pylori eradication and control subjects. CONCLUSION: Pgp might be one of the causes of therapy failure in patients with H pylori and antibiotic therapy could be chosen and followed up on the basis of the Pgp transporter local activity.     

Analysis of recombinant <Emphasis Type="Italic">Plum pox virus</Emphasis> (PPV) isolates from Serbia confirms genetic homogeneity and supports a regional origin for the PPV-Rec subgroup

Summary. The recent observation of the frequent occurrence of natural recombinant Plum pox virus (PPV) isolates has led to the identification of a distinct PPV subgroup, named PPV-Rec. The diversity, origin and geographical spread of the recombinant PPV isolates belonging to this subgroup remain, however, relatively poorly known. In an effort to further our understanding of these isolates, eight PPV isolates from Serbia, the country from which the first such recombinant (PPV-o6) originated, were characterized. Depending on the genomic region targeted by different typing assays, seven of the eight isolates tested presented discrepancies in their typing behavior. Sequence analysis of the (Cter)NIb-(Nter)CP region confirmed the recombinant nature of these seven isolates which all presented an identical recombination breakpoint identical to previously characterized PPV-Rec isolates. Biological indexing and immunoblot analysis provided indications that asymptomatic infection of the GF305 peach indicator and migration of the coat protein as a double-band in immunoblots may represent conserved and discriminating properties of PPV-Rec isolates. The genetic diversity of PPV-Rec isolates from former Yugoslavia (Serbia, Bosnia and Herzegovina) was estimated to be twice as large as that of the PPV-Rec isolates obtained from all other countries to date (Albania, Bulgaria, Czech republic, Germany, Hungary and Slovakia). These last results are consistent with the hypothesis that former Yugoslavia is the center of dispersion of PPV-Rec. Taken together, the results presented here provide further evidence for the wide distribution and temporal genetic stability of these natural PPV recombinant isolates and provide for the first time a possible scenario for their dispersion throughout central and eastern Europe.     

Bidirectional effects of benzodiazepine binding site ligands in the passive avoidance task: differential antagonism by flumazenil and beta-CCt

Recent research on genetically modified mice has attributed the amnesic effect of benzodiazepines mainly to the alpha1-containing GABA(A) receptor subtypes. The pharmacological approach, using subtype selective ligands, is needed to complement genetic studies. We tested the effects of the non-selective antagonist flumazenil (0-20.0 mg/kg), the preferential alpha1-subunit selective antagonist beta-carboline-3-carboxylate-t-butyl ester (beta-CCt) (0-30.0 mg/kg), the non-selective agonist midazolam (0-2.0 mg/kg), the preferential alpha1-subunit selective agonist zolpidem (0-3.0 mg/kg), and the non-selective inverse agonist methyl 6,7-dimethoxy-4-ethyl-beta-carboline-3-carboxylate (DMCM) (0-2.0 mg/kg) in the one-trial step-through passive avoidance task in rats. The compounds were administered intraperitoneally, before the acquisition test. Flumazenil and beta-CCt did not affect retention performance. Midazolam and zolpidem induced amnesia in a dose-dependent manner. The complete reversal of amnesia was unattainable. The effects of zolpidem were significantly attenuated by the both, flumazenil (10.0 mg/kg) and beta-CCt (30.0 mg/kg); by contrast, only flumazenil was considerably effective when combined with midazolam. DMCM exerted promnesic effects at 0.2mg/kg, in an inverted U-shape manner. Both antagonists tended to abolish this action. The results indicate that some other alpha-subunit(s), in addition to the alpha1-subunit, contribute to the amnesic actions of non-selective benzodiazepine site agonists in the passive avoidance task. On the other hand, a significant part of the DMCM-induced promnesic effect could involve the alpha1-subunit and/or other putative beta-CCt-sensitive binding site(s).     

Early results of cementless hip arthroplasty in the treatment of femoral head posttraumatic and atraumatic osteonecrosis

AIM: To evaluate the value of cementless hip arthroplasty in the treatment of posttraumatic and atraumatic osteonecrosis (ON) of the femoral head. METHODS: The study was conducted at the Department of Orthopedics and Traumatology, Military Medical Academy, between January 1st, 1999 and December 31st, 2003. Twenty-five patients with 27 implanted endoprostheses, and the diagnosis of osteonecrosis of the femoral head, and radiographically confirmed Arlet-Ficat stage III and IV were evaluated retrospectively. The results were evaluated according to Harris Hip Score (HHS). The research included 10 patients with traumatically induced osteonecrosis and 15 patients (17 endoprothesis) with osteonecrosis of the femoral head. The mean age of the patients in the group with posttraumatic osteonecrosis of the femoral head was 41 (19-62) years, and in the group of the patients with atraumatic osteonecrosis of the femoral head it was 40.2 (21-53) years. Complications included one case with postoperative luxation, and one case with iatrogenic sciatic nerve palsy. RESULTS: The average Harris Hip Scores in the group of posttraumatic osteonecrosis were 31 points preoperatively and 86 points postoperatively. In the group of osteonecrosis of atraumatic etiology, the average Harris Hip Score was 28 points preoperatively, and 77 points postoperatively. Postoperative Harris Hip Scores were compared with the Student's t-test and the results showed no statistically significant difference (p = 0,125). CONCLUSIONS: Our study did not find any significant difference between the results of posttraumatic and atraumatic osteonecrosis of the femoral head treated with cementless endoprosthesis.     

Acute leg compartment syndrome after exertion

A case of a 22-year old soldier, with a history of pain in the leg during heavy exercise, which desisted at rest, was presented. One day before admission, the patient had felt an extreme exertion-induced pain in his right leg which had not lessenned at rest. At the same time, the patient noticed persistent severe leg edema. On physical examination, the intracompartmental pressure was 62 mmHg (> 30 mmHg). The patient was urgently operated on, and fasciotomy according to Mubarak was used. At second surgery, the debridement of the muscles of the posterior group of the leg, and the evacuation of hemathoma from the anterior and lateral group of the right leg muscles were perfomed. Postoperative recovery was uneventful. Fasciotomy wounds were closed within 14 days of the surgery. The complete physical treatment was done. Follow-up examinations 1, 3, and 6 months afterwards were satisfactory. The soldier completed his compulsory military service without any sequelae. Laboratory results were normal. Overlooked, unrecognized or surgically untreated compartment syndrome can cause severe damage, including even the loss of the extremity.     

Tertiary blast injury to the intestines

BACKGROUND: To present the first case of the tertiary blast injury to the intestine, and the tertiary blast injury in general. CASE REPORT: A parachutist of the Army of Serbia and Montenegro was injured when descended from the 1 200m height by parachute which did not expand. The force of stroke to the ground, caused the reactive transfer of energy and the subsequent blast injury to the intestine. After 24 hours, the secondary perforation of the small intestine, contusioned by the blast, developed which was the indication of explorative laparotomy. The resectioned small intestine showed the histologic characteristics of a blast injury, so the tertiary blast injury was diagnosed on the basis of these and of the mechanism of the injury. CONCLUSION: Tertiary blast injuries fall into the group of indirect blast injuries. The only difference between indirect injuries as compared to direct ones, is in the manner of inflicting, otherwise the traumatic mechanisms are alike, and include the transfer of the energy of stroke through the tissue of different density.     

Prolonged survival of a female patient with total pelvic exenteration

BACKGROUND: To present a female patient who lived 5 years after total pelvic exenteration (TPE). CASE REPORT: The female patient underwent TPE due to retrovesicovaginal fistula as a consequence of locoregional irradiation after the operation for the malignoma of the vaginal part of the uterus. In the formation of Bricker conduit, the ureter antireflux was achieved by the application of the "tobacco sack muff" made of the intestines around the ureter. By the use of this technique, the occurrence of pyelonephritis, as the leading cause of death in such patients, was prevented. CONCLUSION: TPE is a hope for significantly prolonged survival of patients with advanced pelvic malignomas, or with a postirradiatiation fistula.