Tumour initiation and progression occur due to oncogenic mutations that also contribute to therapeutic resistance in many human tumours. Mutations activating the "PI3K/AKT" signalling pathway and inactivating the "TP53" tumour suppressor gene are common mechanisms that cancer cells require to proliferate and escape pre-programmed cell death. p53 mutant (p53mut) tumours not only fail to respond to DNA damaging therapy, but are also described to promote therapeutic resistance by dominant negative suppression of p53 dependent promoter activity. Our work identifies the crucial interaction between the PI3K/AKT pathway and p53 mutations that regulate treatment sensitivity in tumours. Using a combination of in vitro and in vivo techniques we demonstrate that AKT inhibition promotes reduced cellular levels of p53mut via a novel Nucleophosmin 1 (NPM) mediated regulation of the tumour suppressor p14ARF and promotes re-engagement of cell cycle arrest, senescence and increased sensitivity to ionising radiation in both in vivo and in vitro systems. We show that the PI3K/AKT pathway plays an important role in the regulation of p53mut and inhibitors of this pathway can re-sensitise treatment resistant tumours. This has helped us to simultaneously highlight the cohort of patients where the greatest efficacy may be achieved in clinical practise. We further show that the AKT mediated regulation of NPM that we describe in solid tumours is relevant in Acute Myeloid Leukaemia (AML) with mutated NPM, albeit showing physiologically different effects. This further highlights the necessity for rational treatment planning with the newer targeted agents that inhibit specific signalling pathways in AML patients.

Infections in patients with acute liver failure (ALF) and acute liver injury (ALI) are a frequent occurrence. Because ALF and ALI patients share many of the same clinical features as patients with severe sepsis and septic shock, identifying an infection based upon clinical manifestations is extremely difficult. Bacterial culture and sensitivity reports require 24 to 72 hours to be finalized after the need for a culture is suspected and obtained. During this time period, ALF and ALI patients are either not receiving required antibiotic therapy, receiving antibiotic therapy that is not required or not appropriate for the infecting bacterial pathogen, or receiving the correct antibiotic prophylaxis. Receiving an antibiotic that is not needed or inappropriate adds another level of complexity to the ALF and ALI patients because antibiotics may exacerbate liver dysfunction. The purpose of this study was to determine the utility of serum procalcitonin concentrations (SPCTC) as a biomarker of bacterial infections in patients with acute liver failure (ALF) and acute liver injury (ALI). This three part study measured SPCTC retrospectively on samples from ALF and ALI patients who were prospectively enrolled in the United States Acute Liver Failure Study Group (USALFSG) ALF and ALI studies. In the first part of the study, subjects were categorized according to how many SIRS continuum components they had and whether there was a documented infection. In the second part, serial samples on subjects who developed infections were identified. And, in the third part, serial samples on subjects diagnosed with infection on day one of the study and categorized based upon transplant free survival (TFS) or death and/or liver transplant (DoT) were identified. Procalcitonin was not found to be useful in identifying infection in the ALF and ALI patient populations. A cut-off for indication of infection was calculated to be 1.62 ng/mL using receiver operator curve (ROC) analysis. Despite the fact that there was an overall increase in SPCTC as the severity of illness increased in patients with a documented infection, there were confounding variables including antibiotic use, missing data, and small sample size that may have contributed to the poor sensitivity and specificity (0.643 and 0.620 respectively) calculated as part of the ROC analysis. SPCTC values appeared to be increased in subject with acetaminophen (APAP) toxicity and may have affected the cut-off, sensitivity, and specificity results. Increased SPCTC values were seen in APAP subjects who did not have a documented infection. It is unknown at this time if the SPCTC were increase due to liver damage, an undiagnosed infection, or as a result of increase cytokine production due to the APAP toxicity. Serial PCT concentrations in patients who achieved TFS showed a greater decrease over time than those of patients who died or received a liver transplant, however, the TFS group contained a large portion of APAP subjects. Further prospective studies are needed to determine the extent of interference with SPCTC in patients with APAP toxicity and to better define the PCT concentration cut-off between infection and no infection in the ALF and ALI populations.

Research regarding the development of cardiovascular disease (CVD) is important because CVD is the leading cause of death in the United States (US) and many countries abroad. Risk factors, such as obesity and psychological stress, should be studied in order to understand contributing factors for CVD and the cellular mechanisms which link risk factors with the development of disease. Specifically, the combined influence of multiple risk factors on inflammation is of interest because many individuals have more than one risk factor, which additively increases an individual’s risk for CVD. Obesity is already characterized by disordered inflammation, which suggests that the additional burden of a psychological stressor could elicit a greater inflammatory response and a greater risk for CVD than either stressor alone. The documents included within this thesis include the significance and specific aims of the study in addition to a review of the relevant literature related to the effects of obesity and acute mental stress (AMS) on endocrine and inflammatory markers. Specifically, this study aims to address IL-1β, IL-1Ra, and leptin following an AMS task in non-obese and obese individuals. Additionally, a manuscript is included which evaluates the change in IL-1β, IL-1Ra, and leptin following a 20 minute AMS task. Variables were examined between groups at baseline and at two time points following AMS. Additionally, the relationships among the changes in the markers following AMS were examined. Appendices include expanded methodology and all questionnaires used.

An 11 year old, hispanic girl with a history of B-cell acute lymphoblastic leukemia was admitted to the hospital for symptoms compatible with Bartonella henselae infection. The first molecularly diagnosed case of disseminated Bartonella henselae infection was reported in an immunocompromised patient in Lima, Peru. The analysis was confirmed by Polymerase Chain Reaction and automated sequencing of a liver biopsy sample, even though the serologic tests were negative. In conclusion, Bartonella spp. infection should have a particular diagnostic consideration in immunocompromised patients with fever of unknown origin and further investigation regarding the patient's past exposures with cats should also be elicited.

No description available.

Acute lymphoblastic leukemia (ALL) is the most common childhood malignancy. Most ALL cases originate from immature B-cells (BCP-ALL) and are characterized by reoccurring structural genetic aberrations. These aberrations hold information of the pathogenesis of ALL and are used for risk stratification in treatment. Despite increased knowledge of genetic aberrations in pediatric T-cell ALL (T-ALL), no reliable molecular genetic markers exist for identifying patients with higher risk of relapse. The lack of molecular prognostic markers is also evident in patients with relapsed ALL. During the last decades, aberrant epigenetic mechanisms including DNA methylation have emerged as important components in cancer development. Telomere maintenance is another important factor in malignant transformation and is crucial for long-term cell survival. Like DNA methylation, telomere length maintenance has also been implicated to reflect outcomes for patients with leukemia. In this thesis, the prognostic relevance of DNA methylation and telomere length was investigated in pediatric ALL at diagnosis and relapse. The telomere length (TL) was significantly shorter in diagnostic ALL samples compared to normal bone marrow samples collected at cessation of therapy, reflecting the proliferation associated telomere length shortening. Prognostic relevance of TL was shown in low-risk BCP-ALL patients where longer telomeres at diagnosis were associated with higher risk of relapse. Genome-wide methylation characterization by arrays in diagnostic T-ALL samples identified two distinct methylation subgroups denoted CIMP+ (CpG Island Methylator Phenotype high) and CIMP- (low). CIMP- T-ALL patients had significantly worse outcome compared to CIMP+ cases. These results were confirmed in a Nordic cohort treated according to the current NOPHO-ALL2008 protocol.  By combining minimal residual disease (MRD) status at treatment day 29 and CIMP status at diagnosis we could further separate T-ALL patients into risk groups. Likewise, the CIMP profile could separate relapsed BCP-ALL patients into risk groups, where the CIMP- cases had a significantly worse outcome compared to CIMP+ cases.  From these data we conclude that DNA methylation subgrouping is a promising prognostic marker in T-ALL, as well as in relapsed BCP-ALL two groups where reliable prognostic markers are currently missing. By elucidating the biology behind the different CIMP profiles, the pathogenesis of ALL will be further understood and may contribute to new treatment strategies.

Master of Science / Department of Clinical Sciences / Daniel U. Thomson / Acute Interstitial Pneumonia (AIP) is a costly issue that affects feedlot cattle, especially during hot and dry summers. Research has yet to elucidate the exact etiology of AIP; therefore this study was conducted to determine possible factors that contribute to AIP in feedlot cattle. During the summer of 2011 in a 55,000 head feedyard in southwest Kansas, animals exhibiting clinical signs of AIP were selected for ante-mortem examination and data collection. The animal population within the feedlot consisted of 75% heifers and 25% steers. Approximately 50% of the animal population was black hided animals. Ante-mortem data consisted of rumen gas cap measurement for NH3 and H2S, rumen pH, serum chemistry, rectal temperature, and body weight. Post-mortem cases with and without ante-mortem evaluations were also selected for an additional examination. Postmortem examination included similar data as ante-mortem examination with addition of visual and histological examination of lung tissue. There were 31 ante-mortem cases of clinical AIP with the following observations (mean ± SD): rectal temperature 105.3 ± 0.7 °F, weight 1098 ± 123 lbs., H2S 136 ± 133.3 ppm, and rumen pH 6.4 ± 0.5. Twenty-five healthy cohorts were selected from identical pens to serve as controls. Observations from control animals were: rectal temperature 103.7 ± 1.1 °F, weight 1113 ± 133.3lbs, H2S 269.8 ± 311.6 ppm and rumen pH 6.2 ± 0.6. A total of 61 post-mortem cases with a preliminary diagnosis of AIP were analyzed and displayed the following values: H2S 1279.7 ± 1569 ppm, and rumen pH 6.3 ± 0.36. Fifty-three of these postmortem cases had diffuse, focal and /or patchy AIP confirmed by histology.

Call number: LD2668 .T4 1986 R63 / Master of Science / Diagnostic Medicine/Pathobiology

Renal ischemia/reperfusion (I/R) is a main cause of acute kidney injury (AKI) and delayed graft function after renal transplantation. Previous studies in human and experimental models have identified that inflammation and oxidative stress are two key players in renal I/R injury. However, the underlying mechanisms remain speculative. The overall objective of the study was to investigate the biochemical and molecular mechanisms of I/R-induced renal injury and the effect of tyrosol supplementation on I/R-induced kidney oxidative stress damage. In the present study, renal I/R was induced in Sprague-Dawley rats and in a human kidney proximal tubular cell line. A significantly elevated expression of pro-inflammatory cytokine expression (MCP-1, IL-6) was observed. There was a significant decrease in mRNA and protein levels of two hydrogen sulphide (H2S)-producing enzymes, CBS and CSE, with a concomitant reduction of glutathione and H2S production. In the cell culture model, hypoxia–reoxygenation of proximal tubular cells led to a decrease in CBS and CSE expression and an increase in pro-inflammatory cytokine expression. Supplementation of glutathione or H2S donor (NaHS) effectively abolished cytokine expression in tubular cells. Experiments were conducted to detect oxidative stress markers. It was demonstrated that there was a significant increase in peroxynitrite formation and lipid peroxidation in the kidney after I/R insult, which might be caused by the elevation in nitric oxide (NO) metabolites and inducible nitric oxide synthase (iNOS). Administration of tyrosol, a natural phenolic compound, reduced peroxynitrite formation, lipid peroxidation and the level of NO metabolites via inhibiting NF-B activation and iNOS expression. Tyrosol treatment improved kidney function and had a protective effect against I/R-induced AKI. The present study has clearly demonstrated that (1) there is a reduction of H2S production via inhibition of CBS and CSE expression, which contributes to increased pro-inflammatory cytokine expression in the kidney and in tubular cells upon I/R insult; (2) restoration of endogenous H2S production would be of therapeutic value in regulating inflammatory response in I/R-induced kidney injury; (3) tyrosol treatment has a beneficial effect against renal I/R-induced oxidative stress, in part, through its inhibition on NF-B activation and iNOS-mediated NO production. / May 2016

La gastroenteritis ocasionada por rotavirus se encuentra entre las principales causas de morbilidad y mortalidad infantil. En el Perú rotavirus representa el 30% de las muertes por diarrea y 4% del total de defunciones, afectando principalmente a niños menores de 5 años. Desde el año 2009 el Perú implementó la vacuna contra rotavirus en su programa de vacunación universal, sin embargo, debido a la aparición de genotipos emergentes, es importante monitorear la diversidad del virus para evaluar los posibles efectos sobre la eficacia de la vacuna. Pese a esto, existen escasos reportes de la epidemiología de rotavirus en nuestro país. El objetivo del presente estudio es determinar la presencia y los genotipos G y P de Rotavirus en muestras provenientes de niños con gastroenteritis aguda atendidos en un hospital de Lima entre Octubre del 2013 y Octubre del 2014. Como metodología se utilizó el RT-PCR en tiempo real (qRT- PCR) para la detección del rotavirus y el RT PCR convencional para la genotipificación de las muestras positivas, asimismo se secuenciaron algunas muestras para determinar los genotipos finales. De las 448 muestras analizadas en el estudio, 45 (10%) tuvieron resultado positivo para rotavirus. Entre los genotipos identificados, G12 (40.9%), G2 (25%) y P[8] (77.3%) fueron los más frecuentes y la combinación G/P más dominante fue G12P[8] (54.5%). Los resultados evidenciaron una alta prevalencia de G12P[8]entre los casos positivos, genotipo no reportado previamente en el Perú. Se recomienda realizar nuevos estudios para evaluar las variaciones en la diversidad de rotavirus circulantes en el Perú y los posibles efectos ante la presión selectiva de la vacuna.Rotavirus gastroenteritis is one of the leading causes of morbidity and mortality in children. In Peru rotavirus represents 30% of deaths due to diarrhea and is responsible of 4% of the total deaths, affecting mostly children under 5 years. Peru implemented the rotavirus vaccine in its universal vaccination program since 2009. Due to the appearance of emerging genotypes, it is important to evaluate the diversity of the virus in order to determine possible effects on vaccine efficacy. However there are few reports on the molecular epidemiology of rotavirus in our country. The aim of this study was to determine the presence and Rotavirus G and P genotypes in samples from children with acute gastroenteritis attended in a hospital in Lima between October 2013 and October 2014. The method usedfor the detection of rotavirus was real time RT-PCR (qPCR) and conventional RT-PCR to determine the genotype of positive samples. Additionally, sequencing was used to confirm the final genotype of some samples. Of the 448 samples analyzed, 45 (10%) were positive for rotavirus.G12 (40.9%), G2 (25%) and P[8] (77.3%) were the most frequent genotypes and the most prevalent G/P combination was G12P[8] (54.5%). The results showed a high prevalence of G12P[8] among the positive cases. G12P[8] has not been previously reported in Peru. We recommend more in deep studies to identify the diversity of circulating genotypes in Peru.