Cytoskeleton disruption causes apoptotic degeneration of dentate granule cells in hippocampal slice cultures

Colchicine, a potent microtubule-depolymerizing agent, is well known to selectively kill dentate granule cells in the hippocampal formation in vivo. Using organotypic cultures of rat entorhino-hippocampal slices, we confirmed that in vitro exposure to 1 μM and 10 μM of colchicine reproduced a specific degeneration of the granule cells after 24 h. Similar results were obtained with other types of microtubule-disrupting agents, i.e., nocodazole, vinblastine, and Taxol. Interestingly, the actin-depolymerizing agents cytochalasin D and latrunculin A also elicited selective neurotoxicity in the dentate gyrus without affecting survival of hippocampal pyramidal cells. The selective pattern of degeneration was observable 24 h after a brief treatment with the toxins as short as 5 min, but this delayed neuronal death was unlikely to be a result of excitotoxicity because it was virtually unaffected by glutamate receptor antagonists, tetrodotoxin, or extracellular Ca²⁺-free conditions. The damaged tissues contained a large number of TUNEL-positive neurons and exhibited an increased level in caspase-3-like activity, suggesting that cytoskeleton disruption triggers an apoptosis-like process in dentate granule cells. Thus, this study may provide a basis for understanding the distinctive mechanism that supports granule cell survival.     

Effect of the respiratory movements on the intensity of FDG accumulation in PET inspection image

PURPOSE: With chest PET examination, expansion of an image showing a small accumulation and reduction in the radiation count due to breathing movements are anticipated. The purpose of this paper is to analyze movement in the chest region when breathing and to clarify effects of the movement on expansion of the image of a small accumulation and intensity of the radiation count. METHODS: Movements around the hilum of the lung under resting respiration are analyzed in X-rays, CT images and MR images. Based on results of the analysis, breathing movements are reproduced by means of a phantom of our own design. The phantom is adjusted to the PET apparatus so as to change in accordance with the magnitude and movement of a small accumulation to obtain expansion of the image of this part and the intensity of the radiation count. RESULTS: It was found that movements around the hilum of the lung under resting respiration are of a reciprocative kind in the cranio-caudal direction which can be approximated by the fundamental wave. The extent of the image with average amplitude (8.2 +/- 2.8 mm, n = 30) was 6 mm in the cranio-caudal direction. The average amplitude of the radiation count was lowered 38% at 3 mm phi and 22% at 6 mm phi. CONCLUSIONS: It is considered that breathing movement results in a reduction in the radiation count in small accumulations and this may cause underestimation of SUV.     

High concentration of beta-defensin-2 in oral squamous cell carcinoma

We have previously reported the presence of human beta-defensin-2 (HBD-2), a peptide with antimicrobial and cytotoxic properties, in oral squamous cell carcinomas. The aim of the present study was to measure the concentration of HBD-2 in abnormal tissues such as oral squamous cell carcinomas. HBD-2 was extracted from tissue samples in the presence of retinoic acid and subjected to reversed-phase HPLC. The fraction representing peak 17 (P17) was obtained by elution using a linear gradient of acetonitrile. Amino acid sequencing and homology studies were subsequently performed, and the molecular weight of P17 was calculated to be 432702 daltons. This molecular weight was consistent with HBD-2. The concentration of HBD-2 in the oral squamous cell carcinoma samples was 3.85+/-1.87 microg/mg which was much higher than in normal oral epithelium (0.04+/-0.02 microg/mg).     

MRI findings and effectiveness of cyproheptadine in two patients with ophthalmoplegic migraine

We reported the MRI findings and clinical course of two patients with ophthalmoplegic migraine. Both patients presented with unilateral oculomotor nerve palsy. Contrast enhanced MR imaging revealed unilateral enhancement and thickening of the oculomotor nerve in one patient. Prednisolone was effective in both patients, but only could transiently. On the other hand, cyproheptadine hydrochloride could completely prevent recurrent attacks of ophthalmoplegic migraine. Thus, MR imaging with of contrast enhancement is useful in the diagnosis of ophthalmoplegic migraine. Cyproheptadine hydrochloride is better than prednisolone to prevention recurrent attacks and to avoid adverse effects.     

Prevalence of FOXP3+ regulatory T cells increases during the progression of pancreatic ductal adenocarcinoma and its premalignant lesions.

PURPOSE: Antitumor immune response changes drastically during the progression of cancers. Established cancers often escape from the host immune system, although specific immune surveillance operates in the early stages of tumorigenesis in murine models. CD4+CD25+ regulatory T cells (TR) play a central role in self-tolerance and suppress effective antitumor immune responses. The aim of this study was to investigate the clinical significance and roles of TR in the progression and multistep carcinogenesis of pancreatic ductal adenocarcinoma. EXPERIMENTAL DESIGN: We raised anti-FOXP3 antibodies and used them in immunohistochemical studies of the prevalence of FOXP3+CD4+CD25+ TR in the CD4+ T cells, which infiltrated in tissue and draining lymph nodes of 198 pancreatic ductal adenocarcinomas, their premalignant lesions (84 lesions of pancreatic intraepithelial neoplasias and 51 intraductal papillary-mucinous neoplasms), and 15 nonneoplastic pancreatic lesions. RESULTS: The prevalence of TR was significantly increased in the ductal adenocarcinomas compared with that in the stroma of nonneoplastic inflammation (P<0.0001). The increased prevalence of T(R) was significantly correlated with certain clinicopathologic factors. A better prognosis was observed in patients with a low prevalence of T(R), and this was independent of other survival factors (P<0.0001). Infiltration of intraepithelial CD8+TIA-1+ cytotoxic T cells in pancreatic ducts was marked in low-grade premalignant lesions but diminished during the progression of both pancreatic intraepithelial neoplasias and intraductal papillary-mucinous neoplasms. Conversely, the prevalence of TR increased significantly during the progression of premalignant lesions. CONCLUSIONS: T(R) play a role in controlling the immune response against pancreatic ductal carcinoma from the premalignant stage to established cancer. In pancreatic ductal carcinoma, a high prevalence of TR seems to be a marker of poor prognosis.     

A clinically relevant CTLA4-Ig-based regimen induces chimerism and tolerance to heart grafts

BACKGROUND: We determined whether a nontoxic CTLA4-Ig-based conditioning regimen effected mixed chimerism and donor-specific tolerance when heart and bone marrow were transplanted simultaneously. METHODS: Fully mismatched rat strain combinations were used. Recipients received total-body irradiation (300 centigrays), bone marrow (10(8) cells), and cardiac transplants from the donor on day 0. Subsequently, recipient animals received CTLA4-Ig (2 mg/kg, every other day, x 5 doses), tacrolimus (1 mg/kg/day; days 0 to 9), and one dose (10 mg) of antilymphocyte serum on day 10. RESULTS: All bone marrow recipients (n = 7) developed mixed chimerism (mean = 25% +/- 9% at 1 year) and accepted cardiac allografts permanently (> 375 +/- 32 days). Recipients that received conditioning regimen but no bone marrow (n = 5) rejected donor hearts within 51 +/- 13 days (p < 0.01). Recipients that accepted heart grafts also permanently accepted (> 180 days) donor-specific skin grafts, but rapidly rejected (< 10 days) third-party skin grafts. CONCLUSIONS: A nontoxic CTLA4-Ig-based conditioning regimen effects mixed chimerism and donor-specific tolerance when heart and bone marrow are transplanted simultaneously. This regimen may have clinical application.     

Nemaline myopathy: Histological,histochemical and ultrastructural studies

Summary Histological, histochemical and ultrastructural studies were performed on muscle biopsies from three siblings with congenital nemaline myopathy. Histological studies revealed type I fibre atrophy and type II fibre paucity. Ultrastructural studies of intramuscular nerves showed that the axonal diameters were very narrow compared with the width of myelin lamellae. Granular or membranous osmiophilic material occurred in the adaxonal Schwann cell cytoplasm and had a periodicity of 33–38Å. The neuromuscular junctions showed degenerative features such as glycogen granules or myelin figures in 27.1% of total terminal axons. The secondary synaptic clefts were markedly decreased in number and short in length. Myotendinous junction-like structures were found in 5.5% of the muscle fibres near the neuromuscular junctions, and often near sites of fibre-splitting. Rods in nemaline myopathy might be caused as a result of longitudinal splitting and disruption of fibres due to deficient regeneration of the muscle fibres associated with neurotrophic abnormalities.     

Important prognostic histological parameters for patients with invasive ductal carcinoma of the pancreas

For clinicians, the orthodox histological investigation of patients with invasive ductal carcinoma (IDC) remains important for predicting prognoses. The purpose of the present study was to determine the most important of the known prognostic histological parameters (including fibrotic focus and tumor necrosis), enabling the outcomes of 101 patients with IDC of the pancreas to be predicted accurately. Furthermore, we established a scoring classification consisting of important prognostic histological parameters examined in this study. Multivariate survival analyses showed that invasive tumor size of more than 3 cm, the presence of tumor necrosis, the presence of nerve plexus invasion and lymph vessel invasion scores of 2 or 3 were important prognostic factors. Our scoring classification, consisting of the above four parameters, accurately classified the outcome of patients independent of the invasive tumor size of IDC. We concluded that invasive tumor size of 3 cm or more, the presence of tumor necrosis, the presence of nerve plexus invasion and lymph vessel invasion scores of 2 or 3 are important histological prognostic parameters for patients with IDC of the pancreas. Furthermore, the scoring system consisting of the above four histological parameters is probably a very useful prognostic histological classification for patients with IDC of the pancreas.