The antiproliferative function of violacein-like purple violet pigment (PVP) from an Antarctic Janthinobacterium sp. Ant5-2 in UV-induced 2237 fibrosarcoma

Background In this study, we have investigated the chemotherapeutic potential of a purple violet pigment (PVP), which was isolated from a previously undescribed Antarctic Janthinobacterium sp. (Ant5‐2), against murine UV‐induced 2237 fibrosarcoma and B16F10 melanoma cells. Methods The 2237, B16F10, C50, and NIH3T3 cells were treated with PVP at different doses and for different times, and their proliferation and viability were detected by 3‐[4,5‐dimethylthiazol‐2‐yl]‐2,5‐diphenyltetrazolium bromide (MTT) assay. Cell cycle arrest induced by PVP in 2237 fibrosarcoma cells was assessed by flow cytometry and expression analysis of cell cycle regulatory proteins were done by Western blot. Apoptosis induced by PVP in 2237 cells was observed by annexin‐V/propidium iodide double staining flow cytometry assay and fluorescence microscopy. To further determine the molecular mechanism of apoptosis induced by PVP, the changes in expression of Bcl‐2, Bax and cytochrome c were detected by Western blot. The loss of mitochondrial membrane potential in PVP treated 2237 cells was assessed by staining with JC‐1 dye following flow cytometry. Caspase‐3, Caspase‐9 and PARP cleavage were analyzed by Western blot and Caspase‐3 and ‐9 activities were measured by colorimetric assays. Results In vitro treatment of murine 2237 cells with the PVP resulted in decreased cell viability (13–79%) in a time (24–72 h) and dose (0.1–1 μm )‐dependent manner. The PVP‐induced growth inhibition in 2237 cells was associated with both G0/G1 and G2/M phase arrest accompanied with decrease in the expression of cyclin dependent kinases (Cdks) and simultaneous increase in the expression of cyclin dependent kinase inhibitors (Cdki) – Cip1/p21 and Kip1/p27. Further, we observed a significant increase in the apoptosis of the 2237 fibrosarcoma cells which was associated with an increased expression of pro‐apoptotic protein Bax, decreased expression of anti‐apoptotic proteins Bcl‐2, disruption of mitochondrial membrane potential, cytochrome c release, activation of caspase‐3, caspase‐9 and poly‐ADP‐ribose‐polymerase (PARP) cleavage. Conclusions We describe the anti‐cancer mechanism of the PVP for the first time from an Antarctic bacterium and suggest that the PVP could be used as a potent chemotherapeutic agent against nonmelanoma skin cancers.     

Can outer-to-outer diameter be used alone in diagnosing appendicitis on 128-slice MDCT?

AIM: To assess the frequency of visualization, position and diameter of normal appendix on 128-slice multidetector computed tomography (MDCT) in adult population. METHODS: Retrospective cross sectional study conducted at Radiology Department, Dallah Hospital, Riyadh, Saudi Arabia from March 2013 to October 2013. Non-enhanced computed tomography scans of abdomen and pelvis of 98 patients presenting with hematuria (not associated with abdominal pain, fever or colonic disease) were reviewed by two radiologists, blinded to patient history. The study group included 55 females and 43 males with overall mean age of 54.7 years (range 21 to 94 years). The coronal reformatted images were reviewed in addition to the axial images. The frequency of visualization of appendix was recorded with assessment of position, diameter and luminal contents. RESULTS: The appendix was recorded as definitely visualized in 99% of patients and mean outer-to-outer diameter of the appendix was 5.6 ± 1.3 mm (range 3.0-11.0 mm). CONCLUSION: MDCT with its multiplanar reformation display is extremely useful for visualization of normal appendix. The normal appendix is very variable in its position and diameter. In the absence of other signs, the diagnosis of acute appendix should not be made solely on outer-to-outer appendiceal diameter.     

X-ray crystal structure of bone marrow kinase in the x chromosome: a Tec family kinase

Bone marrow kinase in the X chromosome, a member of the Tec family of tyrosine kinases, plays a role in both monocyte/macrophage trafficking as well as cytokine secretion. Although the structures of Tec family kinases Bruton’s tyrosine kinase and IL‐2‐inducible T‐cell kinase are known, the crystal structures of other Tec family kinases have remained elusive. We report the X‐ray crystal structures of bone marrow kinase in the X chromosome in complex with dasatinib at 2.4 Å resolution and PP2 at 1.9 Å resolution. The bone marrow kinase in the X chromosome structures reveal a typical kinase protein fold; with well‐ordered protein conformation that includes an open/extended activation loop and a stabilized DFG‐motif rendering the kinase in an inactive conformation. Dasatinib and PP2 bind to bone marrow kinase in the X chromosome in the ATP binding pocket and display similar binding modes to that observed in other Tec and Src protein kinases. The bone marrow kinase in the X chromosome structures identify conformational elements of the DFG‐motif that could potentially be utilized to design potent and/or selective bone marrow kinase in the X chromosome inhibitors.     

Expression of delta- and mu-opioid receptors in the ventricular and subventricular zones of the developing human neocortex

Recent research has documented the involvement of the endogenous opioid system in neural development, including neurogenesis and neuronal differentiation. However, the expression of opioid receptors (ORs) in different cell types of the human ventricular and subventricular zones (VZ and SVZ) has not been studied during early gestation. In the present study, we have used immunohistochemistry and quantified the results to demonstrate that the levels of delta- and mu-OR subtypes were high in the VZ and SVZ between 11 and 16 gestation weeks (GW) and decreased by 20GW. These results have also been confirmed by studying OR mRNA expression in the VZ and SVZ. Both delta- and mu-OR subtypes were expressed by multipotential stem cells, newly differentiated neurons and developing glial cells to different extents. However, migrating neurons expressed negligible levels of both OR subtypes. Our results suggest that the opioid system may affect cellular proliferation and/or differentiation of stem cells into neurons and glia during the first and second trimesters of gestation in humans. Since layers II and III of the cerebral cortex are being formed during the second trimester, their development is most likely affected by the opioid system mediated through delta- and mu-ORs.     

Downstaging of hepatocellular carcinoma and liver metastases from colorectal cancer by selective intra-arterial chemotherapy

BACKGROUND: Although resection is the sole chance of cure in patients with hepatocellular carcinoma (HCC) or metastatic colorectal cancer to the liver, most patients are not candidates for surgery at the time of diagnosis. Strategies aiming at downstaging large or multifocal tumors to enable curative resection are appealing. The aim of this study was to evaluate the effects of neoadjuvant selective intra-arterial chemotherapy in noncirrhotic patients with unresectable HCC or metastatic colorectal cancer to the liver in the absence of extrahepatic disease. METHODS: Selective chemotherapy was provided by using a subcutaneous pump device via a catheter placed in the gastroduodenal artery. Chemotherapy regimen included floxuridine (0.2 mg/kg/day for 14 days) in each patient with additional boluses of cisplatin and doxorubicin on day 1 of each cycle in the presence of HCC. Patients were evaluated at 3, 6, 9, and 12 months for possible curative resection. Complete follow-up was available for each patient. RESULTS: Twenty-eight patients with unresectable liver tumors (5 HCC and 23 metastatic colorectal cancer) were included in this study. There were no surgical complications related to pump insertion, and local chemotherapy was started within 1 week of surgery in each patient. The median follow-up in survivors was 31 months (range, 30 months to 5 years). Chemotherapy was well tolerated in 18 (64%) patients. Chemotherapy was discontinued in 4 patients because of abnormal liver function test results, and 2 of them required a biliary stent to relieve a biliary stricture. In 9 patients downstaging enabled curative resection (3 HCC, 6 colorectal metastasis). Seven of these patients were alive and tumor free at the completion of the study, with at least 2 years of follow-up. The actuarial survival rates at 3 years for HCC and colorectal metastases were 60% and 50%, respectively. CONCLUSIONS: About one third of patients with unresectable liver tumors can be successfully treated by neoadjuvant intra-arterial chemotherapy followed by curative resection. This strategy appears particularly promising in patients with large HCC. This approach should be investigated further.     

Rapid quantification of adult and developing mouse spatial vision using a virtual optomotor system

PURPOSE: To develop a simple, rapid method of quantifying the spatial vision of mice. METHODS: A rotating cylinder covered with a vertical sine wave grating was calculated and drawn in virtual three-dimensional (3-D) space on four computer monitors facing to form a square. C57BL/6 mice standing unrestrained on a platform in the center of the square tracked the grating with reflexive head and neck movements. The spatial frequency of the grating was clamped at the viewing position by repeatedly recentering the cylinder on the head. Acuity was quantified by increasing the spatial frequency of the grating until an optomotor response could not be elicited. Contrast sensitivity was measured at spatial frequencies between 0.03 and 0.35 cyc/deg. RESULTS: Grating acuity was measurable on the day of eye opening (postnatal day [P]15: mean acuity, 0.031 cyc/deg) and reached a maximum (approximately 0.4 cyc/deg) by P24. A peak in the contrast sensitivity function emerged on P16 (4.7, or 21% contrast at 0.064 cyc/deg). The peak remained at 0.064 cyc/deg and climbed to a maximum sensitivity of 24.5, or 4% contrast, by P29. Acuity was obtained in each mouse in <10 minutes, and a detailed contrast sensitivity curve was generated in approximately 30 minutes. CONCLUSIONS: The virtual optomotor system provides a simple and precise method for rapidly quantifying mouse vision. Behavioral measures of vision in mice are essential for interpreting the results of experiments designed to reveal the cellular and molecular mechanisms of vision and visual development and for evaluating potential treatments for visual diseases.     

Does the novel PET/CT imaging modality impact on the treatment of patients with metastatic colorectal cancer of the liver?

OBJECTIVE: To compare the diagnostic value of contrast-enhanced CT (ceCT) and 2-[18-F]-fluoro-2-deoxyglucose-PET/CT in patients with metastatic colorectal cancer to the liver. BACKGROUND: Despite preoperative evaluation with ceCT, the tumor load in patients with metastatic colorectal cancer to the liver is often underestimated. Positron emission tomography (PET) has been used in combination with the ceCT to improve identification of intra- and extrahepatic tumors in these patients. We compared ceCT and a novel fused PET/CT technique in patients evaluated for liver resection for metastatic colorectal cancer. METHODS: Patients evaluated for resection of liver metastases from colorectal cancer were entered into a prospective database. Each patient received a ceCT and a PET/CT, and both examinations were evaluated independently by a radiologist/nuclear medicine physician without the knowledge of the results of other diagnostic techniques. The sensitivity and the specificity of both tests regarding the detection of intrahepatic tumor load, extra/hepatic metastases, and local recurrence at the colorectal site were determined. The main end point of the study was to assess the impact of the PET/CT findings on the therapeutic strategy. RESULTS: Seventy-six patients with a median age of 63 years were included in the study. ceCT and PET/CT provided comparable findings for the detection of intrahepatic metastases with a sensitivity of 95% and 91%, respectively. However, PET/CT was superior in establishing the diagnosis of intrahepatic recurrences in patients with prior hepatectomy (specificity 50% vs. 100%, P = 0.04). Local recurrences at the primary colo-rectal resection site were detected by ceCT and PET/CT with a sensitivity of 53% and 93%, respectively (P = 0.03). Extrahepatic disease was missed in the ceCT in one third of the cases (sensitivity 64%), whereas PET/CT failed to detect extrahepatic lesions in only 11% of the cases (sensitivity 89%) (P = 0.02). New findings in the PET/CT resulted in a change in the therapeutic strategy in 21% of the patients. CONCLUSION: PET/CT and ceCT provide similar information regarding hepatic metastases of colorectal cancer, whereas PET/CT is superior to ceCT for the detection of recurrent intrahepatic tumors after hepatectomy, extrahepatic metastases, and local recurrence at the site of the initial colorectal surgery. We now routinely perform PET/CT on all patients being evaluated for liver resection for metastatic colorectal cancer.