<Emphasis Type="Italic">MGMT</Emphasis> promoter hypermethylation is a frequent,early, and consistent event in astrocytoma progression,and not correlated with <Emphasis Type="Italic">TP53</Emphasis> mutation

Hypermethylation of the MGMT gene promoter and mutation of the TP53 tumor-suppressor gene are frequently present in diffuse astrocytomas. However, there is only anecdotal information about MGMT methylation status and TP53 mutations during progression of low-grade diffuse astrocytoma (AII) to anaplastic astrocytoma (AIII) and secondary glioblastoma (sGB). In this study biopsy specimens from 51 patients with astrocytic tumors with radiologically proved progression from low to high-grade malignancy were investigated for the presence and consistency of MGMT promoter hypermethylation and TP53 mutations. For 27 patients biopsy samples both of primary tumors and their recurrences were available. For the other 24 patients histology of either the low-grade lesion or the high-grade recurrence was available. It was found that MGMT promoter hypermethylation and TP53 mutations are both frequent and early events in the progression of astrocytomas and that their status is consistent over time. No correlation was found between MGMT methylation status and the presence of TP53 mutations. In addition, no correlation was found between MGMT promoter hypermethylation and the type of TP53 mutations. These results argue against the putative TP53 G:C>A:T transition mutations suggested to occur preferentially in MGMT hypermethylated tumors.     

The pre-operative stratification of patients with colorectal liver metastases: Computed tomography arterial portography (CTAP) has no added value

Aims

The purpose of this study was to determine if Computed Tomography Arterial Portography (CTAP) has additional value to Contrast Enhanced helical CT (CE-CT) in selecting patients for hepatic surgery or Isolated Hepatic Perfusion/systemic chemotherapy.

Materials and methods

Forty-one patients were included. All CT's were performed in the normal pre-operative work-up of patients with liver metastases in our regular clinical setting and reviewed blinded by a radiologist. For CE-CT and CTAP the number, size (largest diameter) and location of all suspected malignant liver lesions were recorded. The favourable treatment option was determined based on the results of CE-CT and CTAP independently. The therapeutic decision based on CE-CT and CTAP was compared with the definite treatment. For all patients with recorded findings during surgery, consisting of intra-operative ultrasound, liver palpation and histology a standard of reference for lesion detection was available. For these patients detection rates and the fraction of false positive lesions were calculated.

Results

Twenty-seven patients were treated with hepatic resection and/or RFA. Fourteen patients were treated with chemotherapy, 4 with Isolated Hepatic Perfusion (IHP) and 10 with systemic therapy. Based on the findings on CE-CT 31 patients were classified as surgical candidates and 10 as non-surgical patients. Based on the findings on CTAP, surgery should be the treatment of choice in 29 patients and 12 patients were classified non-surgical. CE-CT and CTAP disagreed in two cases (4.9%). Seventy-four metastases were identified at surgery and pathologically proved. CE-CT and CTAP showed 53 (.72) and 66 (.89) metastases, respectively.

Conclusion

Despite a significantly higher detection rate for hepatic metastases, CTAP has no added value in the therapeutic stratification in candidates for resection of hepatic metastases of colorectal cancer.     

Correlation of acetylcholinesterase activity in the brain and blood of wistar rats acutely infected with Trypanosoma congolense

ObjectiveTo investigate the neurotransmitter enzyme Acetylcholinesterase (AChE) activity in the brain and blood of rats infected with Trypanosoma congolense (T. congo).MethodsPresence and degree of parasitemia was determined daily for each rat by the rapid matching method. AChE activity was determined by preparing a reaction mixture of brain homogenate and whole blood with 5, 5-dithiobisnitrobenzioc acid (DTNB or Ellman's reagent) and Acetylthiocholine (ATC). The increase in absorbance was recorded at 436 nm over 10 min at 2 min intervals. Trypanosome species identification (before inoculation and on day 10 post infection) was done by Polymerase chain reaction using specific primers.ResultsThe AChE activity in the brain and blood decreased significantly as compared with the uninfected control. The AChE activity dropped to 0.32 from 2.20 μmol ACTC min^?1mg protein^?1 in the brain and 4.57 to 0.76 μmol ACTC min-1mg protein^?1 in the blood. The animals treated with Diminaveto at 3.5 mg/kg/d were observed to have recovered significantly from parasitemia and were able to regain AChE activity in the blood but not in the brain as compared to the control groups. We also observed, that progressive parasitemia resulted to alterations in PCV, Hb, RBC, WBC, neurophils, total protein, lymphocytes, monocytes and eosinophil in acute infections of T. congo. Polymerase chain reaction (PCR) of infected blood before inoculation and on day 10 post infection revealed 600 bp on agarose gel electrophoresis.ConclusionsThis finding suggest that decrease in AChE activity increases acetylcholine concentration in the synaptic cleft resulting to neurological failures in impulse transfer in T. congo infection rats.     

Enzyme-linked immunospot assays provide a sensitive tool for detection of cytokine secretion by monocytes.

Blood monocytes as well as tissue-differentiated macrophages play a pivotal role in controlling immune reactions. Monocytes regulate the extent, nature, and duration of immune responses by secretion of cytokines. Interleukin 6 (IL-6), tumor necrosis factor alpha (TNF-alpha), IL-10, and IL-12 are of particular interest, since IL-12 shifts the immune response towards a Th1 type, facilitating the production of, e.g., TNF-alpha and IL-6, while IL-10 counteracts Th1 responses and promotes the production of Th2-related cytokines such as IL-4. A tight regulation of these four cytokines keeps the balance and decides whether Th1 or Th2 will predominate in immune reactions. Enzyme-linked immunospot (ELISPOT) assays are among the most-sensitive and -specific methods available for cytokine research. They permit ex vivo identification of individual cells actively secreting cytokines. In the present study we prepared monocytes from healthy subjects' blood and adapted ELISPOT assays to define optimal conditions to detect and enumerate monocytes secreting IL-6, TNF-alpha, IL-10, and IL-12. The optimal time for monocyte incubation was 24 h, and optimal monocyte numbers (in cells per well) were 2,000 for IL-6, 1,000 for TNF-alpha, 50,000 for IL-10, and 100,000 for enumeration of IL-12 secreting monocytes. Among healthy subjects, 10% +/- 5% of the monocytes secreted IL-6, 12% +/- 12% secreted TNF-alpha, 0.1% +/- 0.1% secreted IL-10, and 0.2% +/- 0.3% secreted IL-12 (values are means +/- standard deviations). In conclusion, ELISPOT assays constitute a valuable tool to enumerate monocytes secreting IL-6, TNF-alpha, IL-10, and IL-12 and probably to enumerate monocytes secreting other cytokines and proteins.     

The nitric oxide pathway in pre-eclampsia: pathophysiological implications

Pre-eclampsia, one of the most significant health problems inhuman pregnancy, complicates 6-7% of all gestations and is theleading cause of fetal growth retardation, infant morbidityand mortality, premature birth and maternal death. Recent researchimplicates free radicals in the pathophysiology of pre-eclampsia.This review covers the biochemistry of nitric oxide (NO) andpossible interactions with other free radicals. Studies in therat show that pregnancy is associated with enhanced productionand responsiveness to NO in both reproductive tissues and bloodvessels. Rats infused with N^G-nitro-L-arginine methyl ester(L-NAME, a NO synthase inhibitor) have been used as an animalmodel of pre-eclampsia, and the effects of steroid hormoneson blood pressure in this model have been tested. Results suggestthat pre-eclampsia may be a state of NO deficiency. However,in humans there seem to be contradictions regarding the involvementof NO in maternal adaptation to pregnancy. It is suggested thatNO may be one of several systems that act in concert to maintaina symbiotic relationship between mother and fetus. However,the input of each system may be genetically determined.     

Diagnostic Splenectomy for Visceral Leishmaniasis

A 57-year-old-man with a history of malaise, fever,night sweats and shortness of breath presented a diagnostic challenge to his medical team. He was pancytopaenic and had splenomegaly on admission but other investigations, including bone marrow aspiration, proved inconclusive. After the patient deteriorated clinically, the general surgical team was requested to perform a diagnostic splenectomy. The histology of this showed infection with visceral leishmaniasis. He recovered completely with Amphotericin treatment. Although this is a rare condition, particularly for the general surgeon, this case highlights the difficult position surgeons are often put in when performing major surgery diagnostically.     

Fear for the intraabdominal abscess after laparoscopic appendectomy: not realistic

Background: The risk for intraabdominal abscess (IAA) after laparoscopic appendectomy (LA) is still a matter of debate. The aim of the present study was to evaluate postoperative complications after open (OA) and laparoscopic appendectomy, in particular in perforated appendicitis (PA).Methods: In the period 1999–2002, 331 appendectomies were performed for histological proven appendicitis, 144 by the open and 187 by the laparoscopic technique. Parameters were conversion rate, perforation, wound infection, and IAA.Results: Conversion to OA was done in 20 cases (10.7%). Perforated appendicitis led more frequently to conversion than simple appendicitis (23.5 vs 7.8%; p = 0.007). Perforated appendicitis was equally seen in the open and laparoscopic technique (15 vs 18%). Wound infections after OA, converted and LA for acute appendicitis were 3 of 144 (2.1%), 1 of 20 (5.0%) and 1 of 167 (0.6%), respectively (NS). IAA formation did not differ among the three procedures (3.5 vs 0 vs 3.6%). In PA the rate of IAA formation was increased. However, the risk was not influenced by the technique: Two patients after the OA, none after a converted procedure, and two patients after LA formed an abscess (9.5 vs 0 vs 7.7% [NS]).Conclusion: LA does not lead to more intraabdominal abscesses than the open technique; even for perforated appendicitis the laparoscopic technique can be used safely.