Activation and alteration of lysosomes in multiple system atrophy

Multiple system atrophy (MSA) is a sporadic neurodegenerative disorder. Its histopathological features include glial cytoplasmic inclusions that contain α-synuclein as the main component. Recently, multiple lines of evidence have suggested a role for lysosomes in the pathogenesis of many neurodegenerative diseases. To elucidate whether lysosomes are also implicated in the pathology of MSA, we carried out an immunohistochemical study using antibodies against lysosomal proteins in the brains of patients with MSA and in control brains. A robust increase in the expression and an alteration in the morphology and distribution of lysosomal-protein-positive structures were observed in MSA brains. Double immunohistochemistry demonstrated that lysosomal markers did not colocalize mainly with glial cytoplasmic inclusions, but colocalized with a microglial marker. These immunohistochemical signatures suggest that lysosomes are activated in microglia during the disease process, and play a pivotal role in the pathology of MSA.     

The progression potential of peritoneal dissemination nodules from gastrointestinal tumors

It is necessary to examine the characteristics of the dissemination nodules to establish a therapeutic strategy for peritoneal dissemination from digestive malignancy. Ki-67 expression as a proliferation marker in peritoneal dissemination nodules was investigated. The subjects were 15 patients with gastrointestinal cancers who underwent resection of the primary tumor and disseminated nodules. The expression of Ki-67 in both primary tumor and peritoneal dissemination nodule from each patient was evaluated by immunohistochemistry. Ki-67 labeling index in the original tumor was higher than that in the disseminated nodule in 13 of 15 patients (P < 0.0001). The mean value of Ki-67 labeling index was 42.2% in the 15 original tumors and 18.7% in the 15 disseminated nodules. Proliferative activity in the disseminated nodules was lower than that in the primary tumors. Further examination about characteristics of cancer dissemination is needed to treat patients with peritoneal metastasis.     

Expression of hypoxia-inducible factor 1α predicts clinical outcome after preoperative hyperthermo-chemoradiotherapy for locally advanced rectal cancer

Hypoxia-inducible factor 1α (HIF-1α) is an intrinsic marker of tumor hypoxia. It has been considered that hypoxic conditions reduce radiosensitivity, but the role of HIF-1α in patients treated with preoperative therapy for rectal cancer is still unclear. The aim of this study was to evaluate the predictive value of tumor response to preoperative hyperthermo-chemoradiotherapy (HCRT) and the prognostic significance of HIF-1α expression in patients with locally advanced rectal cancer. Between 2003 and 2006, 50 patients with histologically proven rectal adenocarcinoma who underwent HCRT followed by surgery were investigated. HIF-1α expression was immunohistochemically evaluated using pre-treatment biopsies. The total radiation dose was 40-50 Gy and chemotherapy consisted of 5-FU and LV administered by continuous infusion on Day 1-5, Day 15-19, and Day 29-33 during radiotherapy. Hyperthermia treatment was performed for once a week for 2-5 sessions. The surgical operation was performed 8 weeks after HCRT and each resected specimen was graded by histological criteria of the Japanese Classification of Colorectal Carcinoma. The effects of HIF-1α on clinical outcomes were analyzed by univariate and multivariate analysis. Positive HIF-1α expression was recognized in 42.0% of samples (21/50). Resected specimens that showed pathological grades 1, 2, and 3 numbered 17, 24, and 9 cases, respectively. There were no significant differences between the HIF-1α-positive group and HIF-1α-negative group for pathological grading and pCR. Overall survival (OS) rate at 3 years in the HIF-1α-negative group was 85.2%, which was significantly better than the 60.6% in the HIF-1α-positive group. Recurrence-free survival (RFS) rate at 3 years in the HIF-1α-negative group was 82.8%, being significantly better than 47.6% in the HIF-1α-positive group. In addition, elevated HIF-1α expression was significantly correlated with recurrence-free survival and metastasis-free survival rate in multivariate analysis. HIF-1α expression might be predictive of recurrence-free survival and metastasis-free survival rate for rectal cancer patients treated with HCRT.     

Effects of aphidicolin on Entamoeba histolytica growth and DNA synthesis

We have detected and characterized DNA polymerase activity in cell extracts from trophozoites of Entamoeba histolytica and have found that the activity of E. histolytica is inhibited by aphidicolin, which is a specific inhibitor of eukaryotic nuclear replicative DNA polymerases. The present study was aimed to evaluate the effect of aphidicolin on growth and DNA synthesis by this parasite. Aphidicolin blocked the growth of axenic E. histolytica strain HM-1: IMSS. DNA synthesis was also inhibited by aphidicolin when assayed by incorporation of [3H] thymidine into the DNA. The inhibitory effect of aphidicolin on the growth of E. histolytica was abrogated by removal of the drug, and exposure to 3 microg/ml of the drug for at least 48 hr had little effect on the viability. Synchronous growth was observed in the recovery phase after removal of aphidicolin.     

Effect of cytochalasin D on the growth,encystation, and multinucleation of <Emphasis Type="Italic">Entamoeba invadens</Emphasis>

The effect of cytochalasin D, a specific inhibitor of microfilaments, on the growth, encystation, and multinucleation of Entamoeba invadens was examined. Cytochalasin D blocked the growth of axenic E. invadens strain IP-1 in a dose-dependent manner, which suggests that the drug is effective against this species of Entamoeba as well as against E. histolytica strain HM1: IMSS as previously demonstrated. Encystation of E. invadens as induced in vitro was also inhibited by cytochalasin D. This is the first evidence of the participation of microfilaments in the encystation process. Concentrations of cytochalasin D effective for the inhibition of encystation were lower than those effective for the inhibition of growth. Trophozoites grown with cytochalasin D became multinucleate; more than three nuclei per cell were observed in 71% of trophozoites grown in the presence of the drug as opposed to only 5% of those grown in the absence of the drug. Also, trophozoites grown with cytochalasin D produced multinucleate cysts following their transfer to encystation medium. Encystation with cytochalasin D was more strongly inhibited among trophozoites grown in the presence of the drug than among those grown in the absence of the drug. Also, encystation without cytochalasin D was less frequently observed among trophozoites grown in the presence of the drug than among those grown in the absence of the drug. Thus, the multinucleation of trophozoites induced by cytochalasin D had an inhibitory effect on their encystation. Received: 28 September 1999 / Accepted: 25 November 1999     

An associated molecule, p64, with high-affinity interleukin 2 receptor

TU11 mAb specific for the human interleukin-2 receptor (IL-2R) beta-chain, p75, co-precipitated two molecules, p64 and p55, with the beta-chain in the lysates of cells bearing the high-affinity IL-2R. The co-precipitation was detected in the presence of IL-2 even in the absence of a chemical cross-linker. H-48 mAb specific for the IL-2R alpha-chain completely pre-absorbed p64 as well as p55 and partially pre-absorbed the beta-chain from the lysates. The co-precipitation was also detected in phytohemagglutinin-stimulated normal peripheral blood lymphocytes, which express the high-affinity IL-2R, but not in the cell line cells bearing only the low-affinity IL-2R. The peptide maps indicate that p64 is a molecule distinct from both the alpha- and beta-chains, and that p55 is identical to the alpha-chain. These findings suggest that p64, along with the alpha- and beta-chains, is a component of the high affinity IL-2R complex, and we have tentatively named it the gamma-chain of IL-2R.     

A simple procedure for isolation of tumor-associated antigens by affinity chromatography using fucose-specific Aleuria aurantia lectin

An affinity column containing L-fucose specific Aleuria aurantia lectin was used for the efficient separation of tumor-associated antigens. Five of six glycoconjugates antigens tested, carcinoembryonic antigen (CEA), CA19-9, sialyl Lewis X-i, DU-PAN-2 and CA125, bound to the affinity gel and eluted in high yield with 20 mM L-fucose, but alpha-fetoprotein, which is known to contain fucose in the carbohydrate chain, passed through the column. This column was also proved to be useful for group separation of CA19-9, sialyl Lewis X-i and Leb antigens from a serum sample with gastric cancer.     

Demyelinating neuropathy in a 6‐year‐old girl with autism spectrum disorder

Herein we report the case of a 6‐year‐old girl with autism spectrum disorder (ASD) and weakness in the distal portion of the right upper limb. Although difficult to perform, nerve conduction studies indicated demyelinating neuropathy. Magnetic resonance imaging (MRI) showed swelling a nd high‐intensity signals in the right brachial plexus and cervical spinal roots. The symptoms recovered after a single course of i.v. immunoglobulin. Electrophysiological indices and MRI findings also improved after treatment. This case demonstrates the utility of neuroimaging in addition to electrophysiological assessments for the diagnosis of demyelinating neuropathy, particularly in young patients with ASD.