Absence of smooth muscle actin-positive pericyte coverage of tumor vessels correlates with hematogenous metastasis and prognosis of colorectal cancer patients

OBJECTIVES: Immature microvessels, which are not covered by pericytes, are irregular and leaky. We hypothesized that tumor cells can penetrate immature microvessels more easily than mature microvessels. In this study, we investigated the maturation of angiogenesis by the immunohistochemical staining of colorectal cancer specimens and determined the correlation between the microvessel count or the maturity of microvessels and clinicopathological variables. METHODS: Ninety-two surgical specimens from our department were used. Double immunostaining of endothelial cells with anti-CD34 antibody and pericytes with anti-alpha-smooth muscle actin antibody was performed. The microvessel density (MVD) and microvessel pericyte coverage index (MPI) as an index of microvessel maturation were evaluated. RESULTS: The MVD showed a significant positive correlation with tumor size, depth of invasion and Dukes' stage. The MPI showed a significant positive correlation with the histological differentiation of the tumor tissues and distant metastasis at the time of operation. The high MVD group (> or =26.0, n = 50) tended to have a poorer prognosis than the low MVD group (<26.0, n = 42) (p = 0.097). Next, the 50 patients in the high MVD group were classified into two subgroups of high MPI (> or =78.1%, n = 25) and low MPI (<78.1%, n = 25). MPI showed a significant negative correlation with hematogenous metastasis, and the low MPI group demonstrated a significantly poorer survival than the high MPI group (p = 0.040). CONCLUSIONS: These findings demonstrate that immature neovascularization was observed in poorly differentiated tumors and was correlated with metastasis, resulting in a poorer prognosis. Taken together, not only microvessel density but also vascular maturation were crucial factors for colorectal cancer patients.     

Secondary sclerosing cholangitis with hemobilia induced by pembrolizumab: Case report and review of published work

A 66‐year‐old man was admitted to our department due to cholestatic liver injury. He had received five cycles of pembrolizumab for small‐cell lung cancer. Imaging showed the possibility of sclerosing cholangitis (SC) with hemobilia. Histologically, CD8⁺ T cells had infiltrated the biliary epithelium of the extrahepatic bile duct. We reached the diagnosis of secondary SC induced by pembrolizumab. Although we treated him with high‐dose corticosteroids, laboratory data showed only a moderate response. Clinicians should recognize that immune checkpoint inhibitors can sometimes cause severe and irreversible SC.     

A novel 4-oxo-2(E)-nonenal-derived endogenous thiadiazabicyclo glutathione adduct formed during cellular oxidative stress

Cellular oxidative stress causes increased lipid peroxidation with the concomitant formation of DNA and protein reactive bifunctional electrophiles. Glutathione (GSH) detoxifies these bifunctional electrophiles by forming GSH adducts. Several years ago we discovered 4-oxo-2(E)-nonenal (ONE) as a major bifunctional electrophile derived from lipid hydroperoxides. We have now made the unexpected discovery that glutathione-S-transferase (GST)-mediated GSH addition to ONE occurs primarily to C-1 of the alpha,beta-unsaturated ketone rather than to C-3 of the alpha,beta-unsaturated aldehyde. The resulting intermediate rapidly undergoes two intramolecular cyclizations followed by two separate dehydration reactions to provide an unusual thiadiazabicyclo-ONE-GSH adduct (TOG). Quantification of intracellular TOG was performed using stable isotope dilution liquid chromatography-multiple reaction monitoring/mass spectrometry after the addition of ONE to cells or as an endogenously derived adduct during peroxide-induced oxidative stress. TOG represents the first member of a new class of thiadiazabicyclo GSH adducts that are formed through GST-mediated addition of GSH to reactive intermediates containing the ONE motif during intracellular oxidative stress. ONE formation can potentially result from free radical pathways as well as cyclooxygenase- and lipoxygenase-mediated pathways. Its aldo-keto reductase-mediated reduction product, 4-oxo-2(E)-nonenol (ONO), was also formed and converted to GSH adducts similar to those formed by 4-hydroxy-2(E)-nonenal (HNE). ONO is isomeric with HNE; therefore, protein and peptide adducts ascribed to arise solely from reactions with endogenous HNE will need to be re-appraised.     

An in vitro study demonstrating that haematomas found at the site of human fractures contain progenitor cells with multilineage capacity

We isolated multilineage mesenchymal progenitor cells from haematomas collected from fracture sites. After the haematoma was manually removed from the fracture site it was cut into strips and cultured. Homogenous fibroblastic adherent cells were obtained. Flow cytometry revealed that the adherent cells were consistently positive for mesenchymal stem-cell-related markers CD29, CD44, CD105 and CD166, and were negative for the haemopoietic markers CD14, CD34, CD45 and CD133 similar to bone-marrow-derived mesenchymal stem cells. In the presence of lineage-specific induction factors the adherent cells could differentiate in vitro into osteogenic, chondrogenic and adipogenic cells. Our results indicate that haematomas found at a fracture site contain multilineage mesenchymal progenitor cells and play an important role in bone healing. Our findings imply that to enhance healing the haematoma should not be removed from the fracture site during osteosynthesis.     

Single base substitutions in the capsid region of the norovirus genome during viral shedding in cases of infection in areas where norovirus infection is endemic

Norovirus (NoV) infections are the major cause of food- and waterborne nonbacterial gastroenteritis in Japan. Some individuals showed long-term excretion of the virus into feces in 29 outbreaks of acute nonbacterial gastroenteritis that occurred in Toyama Prefecture, Japan, in fiscal year 2006. In one of these cases, single base substitutions from A to G in the capsid region of the NoV genome were commonly detected in two individuals during virus shedding by direct sequencing of PCR products. The A-to-G substitution was accompanied by an N-to-S amino acid change. The population of clones that possessed A at the corresponding site was gradually replaced by those with G during the infectious course. Although other substitutions were observed in the complete open reading frame 2 sequence, they were not common in these two individuals. NoVs are capable of evolving in the gastroenteric tract.     

Factors associated with deep foot fissures in diabetic patients: a cross-sectional observational study

BackgroundFoot ulcers can develop from fissures in patients with diabetes. It is generally considered that fissures can develop with dry skin due to decreased perspiration associated with autonomic neuropathy. Especially, deep fissures that extend into the dermis may have a higher risk of ulceration than superficial fissures because of damage of skin barrier function. However, distinctions between superficial and deep fissures have not been well described, and specific factors involved in their development are generally unknown.ObjectiveTo investigate factors associated with the superficial and deep foot fissures in patients with diabetes.Design and methodsThis cross-sectional observational study involved 578 patients with diabetes evaluated at a university hospital between September 2007 and March 2008. Patients with foot ulcers or foot defects due to amputation were excluded. Superficial fissures were defined as narrow skin cracks limited to the epidermis. Deep fissures were defined as narrow, deep, linear skin cracks extending to the dermis, possibly with higher ulceration risk than superficial fissures. Logistic regression analysis was performed to analyze factors associated with the depth (superficial or deep) of foot fissures.ResultsThe prevalence of superficial fissures was 9.0%, and that of deep fissures was 3.8%. Presence of superficial fissures was correlated with autonomic neuropathy (OR 2.35, 95% CI 1.20–4.59, p = 0.012). Notably, presence of deep fissures was correlated with autonomic neuropathy and angiopathy (OR 2.88, 95% CI 1.11–7.48, p = 0.030; and OR 3.29, 95% CI 1.30–8.35, p = 0.012, respectively).ConclusionsOur new finding of a correlation between deep fissures and angiopathy suggests that control of blood supply should be effective for preventing deep fissures prone to ulceration. In the future, elucidation of the mechanism of the angiopathy-induced deep fissures will be needed to promote more effective preventive care of fissures.     

Different pathophysiology underlying animal models of fibromyalgia and neuropathic pain: comparison of reserpine-induced myalgia and chronic constriction injury rats

The reserpine-induced myalgia (RIM) rat manifests fibromyalgia-like chronic pain symptoms. The present study explored the pathophysiology underlying the pain symptoms in the RIM rat and the chronic constriction injury (CCI) rat, an animal model of neuropathic pain as a reference. Nerve tissue samples were collected from the nociception-tested animals for pathological examinations. Additionally, the therapeutic efficacy of a sodium channel blocker mexiletine was assessed in both rats. A slight vacuolization in the substantia nigra (SN) occurred in some of the RIM rats without any other histopathological changes in the brain or peripheral neurons. All the RIM rats, with or without vacuolization, showed hypersensitivity to tactile, muscle pressure, and cold stimuli. In the CCI rat, neurodegenerative changes were apparent in the sciatic nerve and the spinal cord only. CCI rats displayed muscle hyperalgesia in addition to tactile and cold allodynia. Pharmacotherapy with mexiletine did not attenuate the pain in the RIM rat, although it was effective in the CCI rat. Taken together, it is not likely that pain symptoms in RIM rats are caused by degenerative changes at the level of primary afferents and spinal cord, as is the case for CCI rats. The significance of the vacuolization in the SN is less clear at present because of the minor extent of the change and the lack of correlation with nociceptive sensitivity. The pain symptoms in RIM rats could be associated with dysfunction of biogenic amines-mediated CNS pain control even without apparent pathologies in the nervous system.