DLC1 encodes GTPase-activating protein with a well-documented tumor suppressor activity. This gene is downregulated in various tumors through aberrant promoter hypermethylation. Five different DLC1 ...isoforms can be transcribed from alternative promoters. Tumor-related DNA methylation of the
DLC1
isoform 1 alternative promoter was identified as being hypermethylated in meningiomas in genome-wide DNA methylation profiling. We determined the methylation pattern of this region in 50 meningioma FFPE samples and sections of 6 normal meninges, with targeted bisulfite sequencing. All histopathological subtypes of meningiomas showed similar and significant increase of DNA methylation levels. High DNA methylation was associated with lack of DLC1 protein expression in meningiomas as determined by immunohistochemistry. mRNA expression levels of 5 isoforms of DLC1 transcript were measured in an additional series of meningiomas and normal meninges. The
DLC1
isoform 1 was found as the most expressed in normal control tissue and was significantly downregulated in meningiomas. Transfection of KT21 meningioma cell line with shRNA targeting DLC1 isoform 1 resulted in increased activation of RHO-GTPases assessed with pull-down assay, enhanced cell migration observed in scratch assay as well as slight increase of cell metabolism determind by MTT test. Results indicate that isoform 1 represents the main pool of DLC1 protein in meninges and its downregulation in meningiomas is associated with hypermethylation of CpG dinucleotides within the corresponding promoter region. This isoform is functional GAP protein and tumor suppressor and targeting of its expression results in the increase of DLC1 related cell processes: RHO activation and cell migration.
There are many discrepancies among the results of studies on the genotoxicity of lead. The aim of the study was to explore lead-induced DNA damage, including oxidative damage, in relation to ...oxidative stress intensity parameters and the antioxidant defense system in human leukocytes. The study population consisted of 100 male workers exposed to lead. According to the blood lead (PbB) levels, they were divided into the following three subgroups: a group with PbB of 20–35 μg/dL (low exposure to lead (LE) group), a group with a PbB of 35–50 µg/dL (medium exposure to lead (ME) group), and a group with a PbB of >50 μg/dL (high exposure to lead (HE) group). The control group consisted of 42 healthy males environmentally exposed to lead (PbB < 10 μg/dL). A comet assay was used to measure the DNA damage in leukocytes. We measured the activity of superoxide dismutase (SOD), catalase, glutathione reductase (GR), glucose-6-phosphate dehydrogenase (G6PD), and glutathione-S-transferase (GST) as well as the concentration of malondialdehyde (MDA), and the value of the total antioxidant capacity. The level of PbB was significantly higher in the examined subgroups than in the control group. The percentage of DNA in the tail was significantly higher in the LE, ME, and HE subgroups than in the control group by 10% (p = 0.001), 15% (p < 0.001), and 20% (p < 0.001), respectively. The activity of GR was significantly lower in the LE and ME subgroups than in the control group by 25% (p = 0.007) and 17% (p = 0.028), respectively. The activity of G6PD was significantly lower in the ME subgroup by 25% (p = 0.022), whereas the activity of GST was significantly higher in the HE subgroup by 101% (p = 0.001) than in the control group. Similarly, the activity of SOD was significantly higher in the LE and ME subgroups by 48% (p = 0.026) and 34% (p = 0.002), respectively. The concentration of MDA was significantly higher in the LE, ME, and HE subgroups than in the control group by 43% (p = 0.016), 57% (p < 0.001), and 108% (p < 0.001), respectively. Occupational lead exposure induces DNA damage, including oxidative damage, in human leukocytes. The increase in DNA damage was accompanied by an elevated intensity of oxidative stress.
The novel inflammatory marker procalcitonin (PCT) was assessed as an index of infection in patients with febrile neutropenia. Blood samples were obtained from 115 patients with febrile neutropenia ...for determination of PCT levels before onset of fever and daily until the resolution of fever. The median PCT level on the first day of fever was 8.23 ng/mL in patients with bacteremia, compared with 0.86 ng/mL in patients with localized bacterial infections (P = .017). The median PCT level on the first day of fever was 2.62 ng/mL in patients with severe sepsis, compared with 0.57 ng/mL in patients with clinically localized infections (P < .001). A dramatic decrease in PCT levels was documented after resolution of the infection; PCT levels were elevated when the infection worsened. Pronounced PCT levels were also found in patients with fever of unknown origin who were responding to antimicrobial chemotherapy, compared with those not responding to treatment with antibiotics. PCT levels were particularly elevated in patients with bacteremia and severe sepsis. These findings provide new insight into the application of PCT in clinical trials as a diagnostic tool of the severity of an infection in patients with febrile neutropenia and of the need to change antimicrobial regimen.
In order to assess the diagnostic value of procalcitonin, 158 patients with febrile neutropenia from centres across Europe were studied. Patients with fever were diagnosed on the basis of either: (1) ...clinical, radiological and microbiological criteria; or (2) the procalcitonin value. In the latter case, concentrations of 0.5-1.0 ng/mL were considered diagnostic of localised infection, concentrations of 1.0-5.0 ng/mL of bacteraemia, and concentrations of > 5.0 ng/mL of severe sepsis. Procalcitonin and C-reactive protein were estimated daily in serum by immunochemiluminescence and nephelometry, respectively. Overall, the sensitivity (specificity) of procalcitonin for bacteraemia was 44.2% (64.3%) at concentrations of 1.0-5.0 ng/mL, and 83.3%(100%) for severe sepsis at concentrations of > 5.0 ng/mL. It was concluded that procalcitonin is a marker strongly suggestive of severe sepsis at concentrations of > 5.0 ng/mL. Estimated concentrations of < 0.5 ng/mL indicate that infection is unlikely, but it was observed that bacteraemia associated with coagulase-negative staphylococci may fail to elevate serum procalcitonin levels.
To define the role of procalcitonin in the differential diagnosis, prognosis and follow-up of critically ill patients.
Prospective study during the 2-year period from January 1998-2000.
One hundred ...nineteen critically ill patients: 29 with systemic inflammatory response syndrome (SIRS) without any signs of infection, 11 with sepsis, 17 with severe sepsis, 10 with septic shock and 52 controls. Daily measurements of procalcitonin were performed by an immunocheminoluminometric assay, and values were correlated to the clinical characteristics of the patients.
Mean concentrations of procalcitonin were 5.45 (95% CI: 2.11, 8.81), 7.29 (95% CI: -1.92,14.59), 6.26 (95% CI: -1.32, 13.85) and 38.76 ng/ml (95% CI: 0.15, 77.38) on the 1st day in patients with SIRS, sepsis, severe sepsis and septic shock, respectively, and were statistically superior to those of control patients. Procalcitonin was gradually diminished over time with the resolution of the syndrome, while it was sustained in the same or more augmented levels upon worsening. Mean concentrations of procalcitonin on the 1st day for patients finally progressing to ARDS, to ARDS and acute renal failure, to ARDS, acute renal failure and DIC and to ARDS, acute renal failure, DIC and hepatic failure were 10.48, 8.08, 32.72 and 43.35 ng/ml, respectively. ROC curves of the sensitivity and specificity of procalcitonin for the evaluation of SIRS and sepsis were similar.
The definite differential diagnosis between SIRS and sepsis may not rely on a single application of procalcitonin but on the complete clinical and laboratory evaluation of the patient with procalcitonin playing a considerable role. Procalcitonin is an early prognostic marker of the advent of MODS; therefore, daily determinations might help in the follow-up of the critically ill patient.
Purpose:
To define whether procalcitonin should be introduced in the diagnostic criteria of sepsis.
Methods:
Procalcitonin was estimated in sera of 105 critically ill patients by an ...immunochemiluminometric assay. Diagnosis was settled by 3 types of criteria: A, the American College of Chest Physicians/Society of Critical Care Medicine (ACCP/SCCM) 1992 criteria; B, the ACCP/SCCM criteria and concentrations of procalcitonin above 1.0 ng/mL as indicative of SIRS/sepsis; and C, the ACCP/SCCM criteria and concentrations of procalcitonin 0.5 to 1.1 ng/mL for SIRS and above 1.1 ng/mL for sepsis.
Results:
Criteria A identified 50.5% of patients with SIRS, 18.1% with sepsis, 0.9% with severe sepsis and 22.9% with septic shock; respective diagnosis by criteria B were 26.7%, 9.5%, 10.5% and 25.7%; and respective diagnosis by criteria C were 19.0%, 25.7%, 9.5%, and 25.7%. Sensitivity of concentrations between 0.5 ng/mL and 1.1 ng/mL was 25.6% for Systemic Inflammatory Response Syndrome (SIRS); and above 1.1 ng/mL 92.8% for sepsis. Sepsis-related death was associated with elevated procalcitonin upon presentation of a clinical syndrome.
Conclusions:
Despite the limited diagnostic value of procalcitonin for SIRS, concentrations of procalcitonin above 1.1 ng/mL are highly indicative for sepsis without, however, excluding the presence of SIRS.
Immunonutrition with diets enriched in polyunsaturated fatty acids (PUFAs) are becoming mandatory for multiple trauma patients. Solutions containing single n-6 PUFAs were administered intravenously ...in an experimental model of trauma. Thirty-five rabbits were studied; 13 controls; 10 administered gamma-linolenic acid (GLA) 30 min after fracture of the right femor; and 12 arachidonic acid (AA). Systolic, diastolic and mean arterial pressures and heart rate were recorded; serum levels of tumor necrosis factor-alpha (TNF
α), malondialdehyde (MDA) and nitrate were estimated before and after therapy. Mean survival of controls, of animals treated with GLA and of animals treated with AA was 0.80, 1.41 and 3.60 days, respectively. Administration of PUFAs induced higher levels of blood pressure; that of AA decreased serum TNF
α and tissue bacterial load compared to controls. Intravenous administration of n-6 PUFAs conferred hemodynamic stability and increased survival in a model of trauma rendering further research mandatory.
Quinupristin/dalfopristin (RP59500) is a novel streptogramin and a semisynthetic derivative of pristinamycins IA and IIB. The following properties of RP59500 were investigated: (i) its in-vitro ...activity against 164 hospital isolates of Staphylococcus aureus, 101 of which were methicillin-resistant (MRSA); (ii) its killing effect against 24 MRSA and seven methicillin-susceptible (MSSA) isolates; (iii) its interactions with rifampicin and ciprofloxacin against 18 MRSA isolates, six susceptible to both rifampicin and ciprofloxacin and 12 resistant to both, at 1 x MIC, 2 x MIC and 4 x MIC. Rifampicin and ciprofloxacin were applied at a concentration equal to their mean serum levels in order to establish the clinical relevance of the results. The MIC50, MIC90, MBC50 and MBC90 of quinupristin/dalfopristin were, respectively, < or = 0.015, 2, 0.12 and 2 mg/L for MRSA isolates and < or = 0.015, 0.06, < or = 0.015 and 0.25 mg/L for MSSA isolates. All isolates were inhibited by quinupristin/dalfopristin. Its killing effect varied with concentration and time, being optimal at 4 x MIC and after 24 h growth. Strains surviving 24 h exposure to this agent had much higher MICs than the parent strain, but only a limited number of them became resistant. Quinupristin/dalfopristin at 2 x MIC and 4 x MIC showed in-vitro synergy with rifampicin against highly resistant isolates mainly at 6 h and 24 h of growth involving 50-83% of MRSA isolates, and showed synergy with ciprofloxacin at 24 h involving 42-75% of isolates. The MIC increase in colonies surviving at 24 h was restricted by the presence of rifampicin or ciprofloxacin. In contrast, the above combinations acted synergically over the total number of MRSA strains susceptible to both rifampicin and ciprofloxacin. The above findings show that quinupristin/dalfopristin is a very potent antistaphylococcal agent, and that its activity against MRSA isolates is enhanced when it is combined with rifampicin or ciprofloxacin.
Based on former studies in experimental animals on the effect of octreotide on serum and ascitic levels of tumor necrosis factor-alpha and interleukin-6 in the field of necrotizing pancreatitis, the ...present study was designed to investigate the effect of octreotide on serum interleukin-6 of patients with acute edematous pancreatitis.
A total of 36 patients with acute edematous pancreatitis and initiation of symptoms 12 hours before their admission were enrolled in the study; 20 were treated with octreotide 200 microg tid and 16 with octreotide 500 microg tid for five days. Blood was sampled at regular time intervals. Interleukin-6 was determined by an enzyme-immunoassay and C-reactive protein by nephelometry.
Mean concentrations of interleukin-6 of patients treated with octreotide 200 microg tid were 59.52 pg/mL before and 94.08, 46.25, 49.94, 58.16 and 26.08 pg/mL at 3, 6, 24, 48 and 72 hours after the start of therapy respectively. Respective values of patients treated with octreotide 500 microg tid were 57.19, 53.07, 57.83, 36.06, 54.29 and 65.49 pg/mL. Mean C-reactive protein of patients treated with octreotide 200 microg tid were 67.37 mg/L before and 48.51, 106.08 and 95.58 mg/L at 24, 48 and 72 hours after the start of therapy respectively. Respective values of patients treated with octreotide 500 microg tid were 65.51, 60.56, 90.68 and 64.22 mg/L.
A transient, but not statistically significant, decrease of serum interleukin-6 levels was documented after administration of octreotide in the field of acute edematous pancreatitis. That decrease was earlier after the application of the 500 microg tid dose than the 200 microg tid dose. Studies with a greater number of patients are mandatory to fully clarify the effect of octreotide, if any, on acute pancreatitis.
PDF
