[Colonic ischemia after open and endovascular aortic surgery : Epidemiology, Risk Factors, Diagnosis And Therapy]. / Kolonischämie nach offener und endovaskulärer Aortenchirurgie : Epidemiologie, Risikofaktoren, Diagnostik und Therapie.

Despite the successful establishment of endovascular techniques, colonic ischemia continues to be a serious complication of aortic surgery.The risk factors for colonic ischemia include aortic aneurysm rupture, prolonged aortic clamping, perioperative hypotension, the need for catecholamine therapy, occlusion of the hypogastric arteries and renal insufficiency.The clinical presentation of postoperative colonic ischemia is often unspecific. Classic symptoms include abdominal pain, diarrhea, peranal bleeding and rise of inflammatory parameters. A specific laboratory parameter for colonic ischemia does not exist. The diagnostic gold standard is endoscopy. Imaging methods such as sonography or computer tomography play only a supportive role. Transmural ischemia resulting in bowel wall necrosis is an indication for emergency surgery, predominantly colonic resection with creation of artificial anus.

Donor-Derived Candida dubliniensis Resulting in Perigraft Abscesses in a Liver Transplant Recipient Proven by Whole Genome Sequencing: A Case Report.

BACKGROUND: The transmission of fungi via transplant, although well-known, has not often been molecularly proven. We describe a case of donor-derived candidiasis verified by whole genome sequencing. CASE DESCRIPTION: The multiorgan donor was a 42-year-old woman with subdural hemorrhage. Procurement of the thoracic organs was performed followed by the abdominal organs. Tissue from the left bronchus grew Candida dubliniensis. The liver recipient was a 63-year-old woman with cryptogenic liver cirrhosis. She was noted to have worsening leukocytosis on postoperative day (POD) 9. Computed tomography of the abdomen and pelvis showed multiple rim-enhancing collections around the graft. Percutaneous drainage was performed. Fluid cultures grew C dubliniensis. C dubliniensis isolated from the donor's left bronchus and the liver recipient's abscesses were verified to be related by whole genome sequencing. We postulate that C dubliniensis colonizing the donor's transected trachea could have contaminated the inferior vena cava when the former was left open after explant of the donor's lungs. A portion of the donor's contaminated inferior vena cava was transplanted along with the liver graft, resulting in the infected collections in the recipient. CONCLUSIONS: Our case report highlights the importance of maintaining a sterile field during organ procurement, especially in a multiorgan donor whose organs are explanted in succession.

Uso de almohadas de gel en recién nacidos de pretérmino se asocia a disminución de deformidad craneana / Using gel pillows in preterm infants is related to decreased cranial deformity

Introducción: la escafocefalia posicional, deformidad craneana típica del recién nacido prematuro, presumiblemente es debida a un inicio anticipado de presión sobre la calota, a un inadecuado control motor que determina un menor cambio de posición y un mayor tiempo de presión asimétrica sobre la calota. El descenso de la presión de puntos de apoyo asimétricos sobre el cráneo podría disminuir la escafocefalia. La superficie de gel puede bajar la presión localizada en el cráneo al disminuir la rigidez de la superficie de contacto. Los estudios existentes, escasos, no son concluyentes al respecto. Objetivo: Mostrar la relación entre el uso de almohadas de gel y la reducción de escafocefalia en recién nacidos de pretérmino. Método: Estudio longitudinal de pacientes prematuros hospitalizados en el servicios de neonatología de un hospital terciario, que utilizaron almohadas de gel por 5 semanas consecutivas, durante al menos el 90 por ciento del tiempo que permanecieron en decúbito. Se realizaron mediciones craneales, considerando el índice de deformidad craneana; la primera medición fue previo al uso de almohadas y luego semanalmente hasta completar 5 semanas. Resultados: 17 pacientes completaron las 5 semanas de protocolo. Edad promedio: 28,9 semanas de gestación (rango 28 a 34). Peso promedio: 1058 grs. (rango 720 a 2000). El índice de deformidad craneana varió desde 70,36 (DE 4,7) al inicio del estudio a 76,95 (DE 3,03) al término del estudio, con una diferencia significativa (p< 0,05). Conclusión: Este trabajo mostró una relación entre reducción del grado de escafocefalia, expresada en el IC, con el uso de almohadas de gel por un período de 5 semanas en RNPT.

Introduction: the positional scaphocephaly is the preterm infants’ typical cranial deformity. And probably is due to improper motor control, which determines minor change in position and longer asymmetric pressure on the skull. Decreasing the pressure of asymmetric support points on the skull, might decrease scaphocephaly. Gel’s surface may decrease localized pressure in the skull thus decreasing the stiffness of the contact surface. There are scarce reports about this issue and all are inconclusive. Objective: To show the relationship between the use of gel pillows and reduction of scaphocephaly in preterm infants. Method: Longitudinal study of preterm infants hospitalized in neonatology service of a tertiary hospital. They used gel pillows for 5 consecutive weeks, for at least 90 percent of the time in prone position. Cranial measurements were performed, considering the index of cranial deformity, the first measurement before to the use of pillows and then weekly until 5 weeks. Results: 17 patients completed the 5-week protocol. Average age 28.9 weeks of gestation (range 28-34), average weight 1058 g. (range 720-2000). The index of cranial deformity ranged from 70.36 (SD 4.7) at baseline to 76.95 (3.03) at the end of the study with a significant difference (p <0.05). Conclusions This study showed a relationship between the degree of reduction of scaphocephaly expressed in the IC, using gel pillows for a period of 5 weeks in preterm infants.

Carcinoma papilar de tiroides en quiste tirogloso / Papillary carcinoma in thyroglossal duct cyst

Background: to report a rare case of papillary carcinoma in thyroglossal duct cyst and discuss its management. Material and Method: a 72 year-old man was clinically diagnosed to have a big thyroglossal duct cyst. Sistrunk's procedure followed by total thyroidectomy on the evidence of papillary cancer in thyroglossal duct cyst. Results: histopathologic examination revealed a papillary carcinoma in the thyroglossal duct cyst and normallity in the thyroid gland. The patient remained free of disease on follow-up. Conclusion: most cancers arising in thyroglossal duct cyst are of low risk, and Sistrunk's procedure with a total thyroidectomy is an adequate treatment for such cancers.

Objetivo: reportar un caso raro de carcinoma papilar en un quiste tirogloso y discutir su manejo. Paciente y Método: un hombre de 72 años a quien se realizó un diagnóstico clínico de un quiste tirogloso, fue llevado a una cirugía de Sistrunk's y luego una tiroidectomía total ante la evidencia de cáncer papilar en el quiste tirogloso. Resultados: el examen histopatológico reveló un carcinoma papilar de tiroides en el quiste tirogloso y la glándula tiroides fue normal, el paciente permaneció libre de enfermedad en su seguimiento. Conclusiones: la mayoría de los cánceres que surgen en quiste del conducto tirogloso son de bajo riesgo, y el procedimiento Sistrunk's con una tiroidectomía total es un tratamiento adecuado para este tipo de cáncer.

Emergence of Klebsiella pneumoniae co-producing NDM-type and OXA-181 carbapenemases.

The emergence of carbapenemase-producing Enterobacteriaceae is a rapidly evolving threat worldwide. Here, we report the molecular characterization of two Klebsiella pneumoniae isolates carrying both bla(OXA -181) and bla(NDM -1) or bla(NDM -5) isolated from epidemiologically unrelated patients in Singapore. The bla(OXA -181) genes were found existing in different genetic environments.

A pilot study of glioblastoma multiforme in elderly patients: treatments, O-6-methylguanine-DNA methyltransferase (MGMT) methylation status and survival.

OBJECTIVES: Elderly Glioblastoma multiforme (GBM) patients have a worse prognosis and receive variable treatments. MGMT gene promoter methylation is linked with improved survival in GBM. We examined treatments administered and survival including in relation to MGMT methylation status in elderly GBM patients. PATIENTS AND METHODS: Patients ≥65 years with diagnosed GBM between 1/01/2007 and 30/04/2009 and undergoing either a biopsy, subtotal (STR) or gross total resection (GTR) were included. The collected information included MGMT status [methylated (ME) vs. unmethylated (UN)] and survival data. p<0.05 was considered significant. RESULTS: 59 patients were identified with median age at diagnosis being 72.68 years (65.72-85.04). Treatment included surgery (25 GTR, 8 STR, 26 biopsy), chemoradiation (22) and radiotherapy alone (20). Overall median overall survival (MOS) was 219 days. MOS with chemoradiation was 316 days vs. 143 days without it (p=0.011). 47 patients had definite MGMT status (28 ME, 19 UN). In ME patients, 9/28 received temozolamide compared to 10/19 in UN category. Temozolamide administration in patients with definite MGMT status was based on WHO performance status (p=0.007). MOS in UN group was 308 days vs. 167 days in ME group (p=0.068). In a multivariate Cox model including use of temozolamide, WHO score and methylation status, only temozolamide use was significantly associated with a reduced risk for death (HR 0.443, 95% CI 0.200-0.982, p=0.045). CONCLUSIONS: In this small cohort of patients, chemoradiation in suitable elderly GBM patients seemed to afford a survival benefit. MGMT methylation was not associated with an improved survival with temozolamide being the only factor leading to a better survival. Temozolamide use should be considered irrespective of MGMT status in this population with future large prospective studies needed to elucidate this further.

Resultados alejados de la cirugía reparadora de la insuficiencia mitral isquémica / Long-term results of mitral valve repair for ischemic mitral insufficiency

Background: The preferred treatment for ischemic mitral insufficiency is mitral valve repair with a prosthetic ring, because it does not deteriorate left ventricular function, allowing better immediate and long-term results. Aim: To assess long-term results of mitral annuloplasty with a prosthetic ring for ischemic mitral insufficiency. Patients and Methods: One hundred patients (68 men), with a mean age of 65.7 ± 8.6 years were included. They underwent a mitral annuloplasty with a prosthetic ring to treat ischemic mitral insufficiency, between February 1992 and May 2009. Fortyfour had a history of prior myocardial infarction and 46 had an evolving acute coronary syndrome. The inferior left ventricular wall was involved, exclusively or associated with an adjacent wall, in 72 cases. Coronary artery bypass grafts were performed in 92 patients and 32 required intra-aortic balloon pumping at some time during the peri-operative period. Results: Operative mortality was 10% (10 patients). During follow-up 30 patients died, at an average of 39 months after surgery (range: 3-142 months). Actuarial long-term survival rates at 1, 3 and 5 years were 79%, 72% and 64.5%, respectively. Trans esophageal echocardiogram performed in the operating room showed none or minimal residual mitral insufficiency in 96% of the cases. Echocardiographic follow-up was completed in 80% of the survivors; 79% of them had no or minimal mitral insufficiency. Only one patient was re-operated on due to severe mitral insufficiency and 4 required a permanent pacemaker. Conclusions: Considering the critical illness of these patients, good long-term results were observed after treatment of ischemic mitral regurgitation performing a mitral annuloplasty with a prosthetic ring.

[Long-term results of mitral valve repair for ischemic mitral insufficiency]. / Resultados alejados de la cirugía reparadora de la insuficiencia mitral isquémica.

BACKGROUND: The preferred treatment for ischemic mitral insufficiency is mitral valve repair with a prosthetic ring, because it does not deteriorate left ventricular function, allowing better immediate and long-term results. AIM: To assess long-term results of mitral annuloplasty with a prosthetic ring for ischemic mitral insufficiency. PATIENTS AND METHODS: One hundred patients (68 men), with a mean age of 65.7 ± 8.6 years were included. They underwent a mitral annuloplasty with a prosthetic ring to treat ischemic mitral insufficiency, between February 1992 and May 2009. Forty four had a history of prior myocardial infarction and 46 had an evolving acute coronary syndrome. The inferior left ventricular wall was involved, exclusively or associated with an adjacent wall, in 72 cases. Coronary artery bypass grafts were performed in 92 patients and 32 required intra-aortic balloon pumping at some time during the peri-operative period. RESULTS: Operative mortality was 10% (10 patients). During follow-up 30 patients died, at an average of 39 months after surgery (range: 3-142 months). Actuarial long-term survival rates at 1, 3 and 5 years were 79%, 72% and 64.5%, respectively. Trans esophageal echocardiogram performed in the operating room showed none or minimal residual mitral insufficiency in 96% of the cases. Echocardiographic follow-up was completed in 80% of the survivors; 79% of them had no or minimal mitral insufficiency. Only one patient was re-operated on due to severe mitral insufficiency and 4 required a permanent pacemaker. CONCLUSIONS: Considering the critical illness of these patients, good long-term results were observed after treatment of ischemic mitral regurgitation performing a mitral annuloplasty with a prosthetic ring.

X-linked adrenoleukodystrophy: clinical course and minimal incidence in South Brazil.

UNLABELLED: X-linked adenoleukodystrophy is a genetic disease that affects the degradation of very long-chain fatty acids. In male patients, common pictures are the cerebral form (CALD), myeloneuropathy (AMN), and Addison-only. OBJECTIVE: To describe the clinical course of affected male patients from South Brazil between 1993 and 2007. METHODS: Affected male patients and their maternal lineages were studied from a clinical, neurological and biochemical standpoint. RESULTS: Eighty-three male patients from 30 families were biochemically evaluated: 51 were affected. 27/51 (54%) presented the cerebral form; 11/51 had AMN (22%); 5 had Addison-only (10%), and 8 (16%) were asymptomatic. Between 2002 and 2006, the minimal incidence was 1:35,000 males in our State (South Brazil). Forty-three affected individuals were followed for 5.4+/-3.7 years. Of 10 boys detected at early stages, three developed CALD. These three boys and another five CALD at baseline were referred to hematopoietic stem cell transplantation. Seven transplants were carried out, 5 with good clinical evolution after 2.2 years post-transplant. The non-transplanted case was later defined as a stable cerebral form. DISCUSSION: Among the present families, the observed cases were comparable to the 50% expected by Mendelian segregation. Based on the natural history, the number of cases that developed CALD was similar to the expected. Transplants were successful in 70% of cases. The occurrence of a stable cerebral form pointed to an urgent need for better markers of active cerebral disease.

[Surgery of post myocardial infarction papillary muscle rupture]. / Cirugía de la rotura de músculo papilar por infarto miocárdico.

BACKGROUND: Papillary muscle rupture is a serious complication of myocardial infarction whose only treatment is surgery. AIM: To analyze our most recent surgical experience with papillary muscle rupture. PATIENTS AND METHODS: The database of our Service was reviewed for the period 1995-2005, to identify patients with papillary muscle rupture. Then, the clinical records and operating protocols were analyzed. Survival and functional class of patients were assessed. RESULTS: Twelve patients (7 men), aged 52 to 89 years, had papillary muscle rupture. They represented 2.2% of all mitral procedures for mitral insufficiency and 8.8% of mitral surgeries for ischemic mitral regurgitation, during the study period. In eight cases myocardial infarction was inferior, in three lateral and in one, anterior. In 10 patients, a mitral replacement was carried-out and in two the mitral valve was repaired. In seven patients, myocardial revascularization was performed. Mean lapse between infarction and surgery was 13.5 days (1 to 85). Two patients died in the perioperative period. Follow-up ranged from 1.7 to 120.4 months. Four patients died during follow-up, 2 due to a cardiovascular cause. Thus, at the end of follow-up 6 patients were alive. All were in functional class I-II. CONCLUSIONS: Papillary muscle rupture is an uncommon complication of myocardial infarction, with considerable operative and long-term mortality. However, survivors have good quality of life.

Cirugía de la rotura de músculo papilar por infarto miocárdico / Surgery of post myocardial infarction papillary muscle rupture

Background: Papillary muscle rupture is a serious complication of myocardial infarction whose only treatment is surgery. Aim: To analyze our most recent surgical experíence with papillary muscle rupture. Patients and Methods: The datábase of our Service was reviewed for the period 1995-2005, to identify patients with papillary muscle rupture. Then, the clinical records and operating protocols were analyzed. Survival and functional class of patients were assessed. Results: Twelve patients (7 men), aged 52 to 89 years, had papillary muscle rupture. They represented 2.2 percent of all mitral procedures for mitral insufficiency and 8.8% of mitral surgeries for ischemic mitral regurgitation, during the study períod. In eight cases myocardial infarction was inferior, in three lateral and in one, anterior. In 10 patients, a mitral replacement was carried-out and in two the mitral valve was repaired. In seven patients, myocardial revascularization was performed. Mean lapse between infarction and surgery was 13.5 days (1 to 85). Two patients died in the perioperative period. Follow-up ranged from 1.7 to 120.4 months. Four patients died during follow-up, 2 due to a cardiovascular cause. Thus, at the end of follow-up 6 patients were alive. All were in functional class III. Conclusions: Papillary muscle rupture is an uncommon complication of myocardial infarction, with considerable operative and ¡ong-term mortality. However, survivors have good quality of life.

Síndrome hemolítico urémico en Chile: presentación clínica, evolución y factores pronósticos / Hemolytic-uremic syndrome in Chile: clinical features, evolution and prognostic factors

Background: Hemolytic-uremic syndrome (HUS) is characterized by acute renal failure, microangiopathic hemolytic anemia and thrombocytopenia. Aim: To describe the characteñstics ofpatients with the diagnosis ofHUS in Chile, and to identify the most reliable early predictors oímorbidity and moñality. Material and methods: The clinical records ofpatients with HUS aged less than 15 years, attended between January 1990 and December 2003 in 15 hospitals, were reviewed. Demographic, clinical, biochemical, hematological parameters, morbidity and mortality were analyzed. Results: A cohort of 587 patients aged 2 to 8 years, 48 percent males, was analyzed. Ninety two percent had diarrhea. At the moment of diagnosis, anuria was observed in 39 percent of the patients, hypertension in 45 percent and seizures in 17 percent. Forty two percent required renal replacement therapy (RRT) and perítoneal dialysis was used in the majoríty of cases (78 percent). The most frequently isolated etiological agentwas Escherichia coli. Mortality rate was 2.9 percent in the acute phase of the disease and there was a positive correlation between mortality and anuria, seizures, white blood cell count (WCC) >20.000/mm³ and requirements of renal replacement therapy (p <0.05). Twelve percent of patients evolved to chronic renal failure and the risk factors during the acute phase were the need for renal replacement therapy, anuria, WCC >20.000/mm³, seizures and hypertension. Conclusions: The present study emphasizes important clinical and epidemiological aspeets ofHUSin a Chilean pediatricpopulation.

Factors influencing survival after relapse from acute lymphoblastic leukemia: a Children's Oncology Group study.

Despite great progress in curing childhood acute lymphoblastic leukemia (ALL), survival after relapse remains poor. We analyzed survival after relapse among 9585 pediatric patients enrolled on Children's Oncology Group clinical trials between 1988 and 2002. A total of 1961 patients (20.5%) experienced relapse at any site. The primary end point was survival. Patients were subcategorized by the site of relapse and timing of relapse from initial diagnosis. Time to relapse remains the strongest predictor of survival. Patients experiencing early relapse less than 18 months from initial diagnosis had a particularly poor outcome with a 5-year survival estimate of 21.0+/-1.8%. Standard risk patients who relapsed had improved survival compared with their higher risk counterparts; differences in survival for the two risk groups was most pronounced for patients relapsing after 18 months. Adjusting for both time and relapse site, multivariate analysis showed that age (10+ years) and the presence of central nervous system disease at diagnosis, male gender, and T-cell disease were significant predictors of inferior post-relapse survival. It can be noted that there was no difference in survival rates for relapsed patients in earlier vs later era trials. New therapeutic strategies are urgently needed for children with relapsed ALL and efforts should focus on discovering the biological pathways that mediate drug resistance.

[Hemolytic-uremic syndrome in Chile: clinical features, evolution and prognostic factors]. / Síndrome hemolítico urémico en Chile: presentación clínica, evolución y factores pronósticos.

BACKGROUND: Hemolytic-uremic syndrome (HUS) is characterized by acute renal failure, microangiopathic hemolytic anemia and thrombocytopenia. AIM: To describe the characteristics of patients with the diagnosis of HUS in Chile, and to identify the most reliable early predictors of morbidity and mortality. MATERIAL AND METHODS: The clinical records of patients with HUS aged less than 15 years, attended between January 1990 and December 2003 in 15 hospitals, were reviewed. Demographic, clinical, biochemical, hematological parameters, morbidity and mortality were analyzed. RESULTS: A cohort of 587 patients aged 2 to 8 years, 48% males, was analyzed. Ninety two percent had diarrhea. At the moment of diagnosis, anuria was observed in 39% of the patients, hypertension in 45% and seizures in 17%. Forty two percent required renal replacement therapy (RRT) and peritoneal dialysis was used in the majority of cases (78%). The most frequently isolated etiological agent was Escherichia coli. Mortality rate was 2.9% in the acute phase of the disease and there was a positive correlation between mortality and anuria, seizures, white blood cell count (WCC)>20.000/mm3 and requirements of renal replacement therapy (p<0.05). Twelve percent of patients evolved to chronic renal failure and the risk factors during the acute phase were the need for renal replacement therapy, anuria, WCC>20.000/mm3, seizures and hypertension. CONCLUSIONS: The present study emphasizes important clinical and epidemiological aspects of HUS in a Chilean pediatric population.

[Microbiologic and molecular diagnostic of cariogenic bacteria in pregnant women from the Araucania Region of Chile]. / Diagnóstico microbiológico y molecular de bacterias cariogénicas en mujeres embarazadas de la Región de La Araucanía, Chile.

Dental caries is a transmissible infectious disease in which Streptococcus mutans is a principal protagonist. Although it is widely believed that pregnancy is harmful to teeth, the effect of pregnancy on the development of caries is not clear. Considering this situation, the aim of the present study was to evaluate the levels of infection and to differentiate bacterial species with cariogenic potential in pregnant women from the Araucania region in Chile, by bacteriological and molecular analysis. In this work, we evaluated 51 pregnant women aged 15 to 40 years. The results show that 100% of women are infected by mutans streptococci Group, and 70.6% exhibited high levels of infection (> 500.000 cfu/mL). The molecular analysis shows that Streptococcus mutans and Streptococcus sobrinus frequencies were 92.1% and 1.9%, respectively. In conclusion, our data suggest that pregnant women are a high risk group for caries development.

[Substance use and risk behaviors of out-of-treatment cocaine base paste and cocaine hydrochloride users]. / Consumo de sustancias y conductas de riesgo en consumidores de pasta base de cacaína no consultantes a servicios de rehabilitación.

BACKGROUND: In Chile, cocaine base paste (CBP) is the illegal substance that produces the highest rate of addiction. Nonetheless, a marginal number of users receive treatment each year. AIM: To compare the consumption patterns and risk behavior of CBP and cocaine hydrochloride (CH) users who do not attend rehabilitation services. MATERIAL AND METHODS: In a prospective research design, through a study methodology called Privileged Access Interview of hidden populations, 28 surveyors recruited 231 CBP users (group 1) and 236 CH users (group 2). The Risk Behavior Questionnaire was applied in four communities of Metropolitan Santiago, that have the highest prevalence of PBC and CH use. RESULTS: CBP users showed higher schools drop-out and unemployment rates. Subjects of both groups were predominantly polysubstance and polyaddicted users. The severity of addiction to CBP of group 1 was significantly higher than the severity of addiction to CH of group 2 (5.5 versus 5.1: p<0.001). CBP users showed significantly higher rates of sexual risk behaviors, antisocial behavior, self infliction of injuries, suicide attempt and child neglect. CONCLUSIONS: A higher vulnerability was shown for users of CBP than those of CH. Attention is drawn to the need for developing community interventions in order to alter substance abuse and the risk behavior of these vulnerable groups.

Effects of iron overload in a rat nutritional model of non-alcoholic fatty liver disease.

BACKGROUND/AIMS: This study sought to determine whether excess hepatic iron potentiates liver injury in the methionine choline-deficient (MCD) model of non-alcoholic fatty liver disease (NAFLD). METHODS: Iron-loaded rats were fed either MCD or control diets [MCD diet plus choline bitartrate (2 g/kg) and DL-methionine (3 g/kg)] for 4 and 12 weeks, after which liver pathology, hepatic iron, triglyceride, lipid peroxidation products and hydroxyproline (HYP) levels and serum alanine aminotransferase (ALT) levels were evaluated. RESULTS: Iron supplementation in MCD animals resulted in histologic evidence of hepatic iron overload at 4 and 12 weeks and a 14-fold increase in hepatic iron concentration at 12 weeks (P < 0.001). Iron supplementation in these animals was associated with increased lobular necroinflammation at 4 weeks (P < 0.02) and decreased hepatic steatosis (P < 0.01), hepatic triglyceride levels (P < 0.01), hepatic-conjugated dienes (CD; P < 0.02) and serum ALT levels (P < 0.002) at 12 weeks. Reduced hepatic steatosis (P < 0.005) and CD (P < 0.01) were apparent by 4 weeks. Iron supplementation was associated with a trend towards increased perivenular fibrosis not hepatic HYP content. CONCLUSION: Hepatic iron overload in the MCD model of NAFLD is associated with decreased hepatic lipid, decreased early lipid peroxidation products, increased necroinflammation and a trend towards increased perivenular fibrosis.

Rodent nutritional model of steatohepatitis: effects of endotoxin (lipopolysaccharide) and tumor necrosis factor alpha deficiency.

BACKGROUND AND AIMS: Intestinal endotoxin (lipopolysaccharide) is thought to contribute to liver injury in both alcoholic and nonalcoholic steatohepatitis (NASH). Tumor necrosis factor alpha (TNFalpha) is an important mediator of this process and is considered central to the inflammatory response in NASH. This study aimed to investigate the effects of lipopolysaccharide on liver injury in the methionine choline deficient (MCD) nutritional model of NASH, and to determine if TNFalpha is required for the development of steatohepatitis in this model. METHOD: Male C57/BL6 mice received a MCD diet for 4 weeks, whilst a control group received an identical diet supplemented with 0.2% choline bitartrate and 0.3% methionine. At 4 weeks, mice received either an intraperitoneal injection of lipopolysaccharide (0.5 microg/g body mass) or sterile saline, and were killed 24 h thereafter. In a separate study, TNFalpha knockout and wild type C57BL/6 mice received either MCD or control diets for 4 weeks. Serum transaminase levels, liver histology (steatosis, inflammation and apoptosis), hepatic triglyceride concentration and hepatic lipid peroxidation products (conjugated dienes, lipid hydroperoxides and thiobarbituric reactive substances, free and total) were evaluated. RESULTS: Intraperitoneal administration of lipopolysaccharide augmented serum alanine aminotransferase (ALT) levels (P<0.02), hepatic inflammation (P<0.025), apoptosis (P<0.01) and free thiobarbituric acid reactive substances (P<0.025) in MCD mice. TNFalpha knockout mice fed the MCD diet developed steatohepatitis with histological and biochemical changes similar to those seen in wild type counterparts. CONCLUSIONS: Lipopolysaccharide augments liver injury in MCD mice, and TNFalpha is not required for the development of steatohepatitis in MCD mice.

Preliminary transcriptional analysis of spoT gene family and of membrane proteins in Rickettsia conorii and Rickettsia felis.

Rickettsiae survival implicates adaptation to different environmental conditions. We hypothesized that multiple copies of genes in bacteria with reduced genomes might account for such a process. Transcription of spoT and sca paralogs was thus analyzed in R. conorii and R. felis.