Reprint of Staged Repair of Tetralogy of Fallot with Pulmonary Atresia and Major Aortopulmonary Collateral Arteries

Tetralogy of Fallot with pulmonary atresia and major aortopulmonary collateral arteries (MAPCAs) is a rare but important anatomical configuration. Unifocalization is one surgical procedure that creates an adequate pulmonary circulation in the setting of MAPCAs. In this text, the variable anatomy of MAPCAs and the correspondingly variable unifocalization procedures are described in seven case presentations.     

Estimation of collimator scatter factor, S(c), of small field sizes using long-SCD method and two saturation models

To estimate the collimator scatter factor, S(c) of small field sizes in which a mini-phantom cannot be fully included at the nominal treatment distance (NTD=100 cm), we measured the in-air output of 4 MV and 10 MV X-rays of a Varian's Clinac 2100 C/D using a mini-phantom at NTD and at a long source-to-chamber distance (SCD=200 cm) with field-size defined at the isocenter down to 4.6 x 4.6 cm(2) and 2.3 x 2.3 cm(2), respectively. We then compared the fitted curve to the NTD dataset by a cumulative exponential distribution model with that by a cumulative Gaussian distribution (error function) model containing a zero-field extrapolated term derived from the long SCD dataset. The results showed that the zero-field extensions of two fitted curves coincided for a 4 MV X-ray, but a large discrepancy was seen between them for a 10 MV X-ray. Therefore, the S(c) of small field sizes not measurable using a mini-phantom at the NTD can be well estimated by applying the cumulative exponential model to the NTD dataset in the case of a 4 MV X-ray beam filtrated with a cone-shaped flattener. However, to estimate the S(c) of such small field sizes in the case of a 10 MV X-ray beam filtrated with a bell-shaped flattener, we consider it preferable to also measure in-air output at a long SCD and to apply the cumulative Gaussian model as described here.     

Lnk-dependent axis of SCF–cKit signal for osteogenesis in bone fracture healing

The therapeutic potential of hematopoietic stem cells/endothelial progenitor cells (HSCs/EPCs) for fracture healing has been demonstrated with evidence for enhanced vasculogenesis/angiogenesis and osteogenesis at the site of fracture. The adaptor protein Lnk has recently been identified as an essential inhibitor of stem cell factor (SCF)–cKit signaling during stem cell self-renewal, and Lnk-deficient mice demonstrate enhanced hematopoietic reconstitution. In this study, we investigated whether the loss of Lnk signaling enhances the regenerative response during fracture healing. Radiological and histological examination showed accelerated fracture healing and remodeling in Lnk-deficient mice compared with wild-type mice. Molecular, physiological, and morphological approaches showed that vasculogenesis/angiogenesis and osteogenesis were promoted in Lnk-deficient mice by the mobilization and recruitment of HSCs/EPCs via activation of the SCF–cKit signaling pathway in the perifracture zone, which established a favorable environment for bone healing and remodeling. In addition, osteoblasts (OBs) from Lnk-deficient mice had a greater potential for terminal differentiation in response to SCF–cKit signaling in vitro. These findings suggest that inhibition of Lnk may have therapeutic potential by promoting an environment conducive to vasculogenesis/angiogenesis and osteogenesis and by facilitating OB terminal differentiation, leading to enhanced fracture healing.Embryonic stem cells in the blastocyst stage have the potential to generate any terminally differentiated cells in the body; however, other adult stem cell types, including hematopoietic stem cells/progenitor cells (HSCs/HPCs), have limited potency for postnatal tissue/organ regeneration. The hematopoietic system has traditionally been considered unique among phenotypically characterized adult stem/progenitor cells (Slack, 2000; Blau et al., 2001; Korbling and Estrov, 2003) in that it is an organized, hierarchical system with multipotent, self-renewing stem cells at the top, lineage-committed progenitor cells in the middle, and lineage-restricted precursor cells, which give rise to terminally differentiated cells, at the bottom (Weissman, 2000). Recently, Takaki et al. (2002) reported that Lnk is expressed in hematopoietic cell lineages, and BM cells of Lnk-deficient mice are competitively superior in hematopoietic population to those of WT mice. They also clarified that not only HSC/HPC numbers but also the self-renewal capacity of some HSCs/HPCs were markedly increased in Lnk-deficient mice (Ema et al., 2005). In addition, they identified the functional domains of Lnk and developed a dominant-negative Lnk mutant that inhibits the functions of Lnk that are endogenously expressed in the HSCs/HPCs and thereby potentiates the HPCs for engraftment (Takizawa et al., 2006). Lnk shares a pleckstrin homology domain, a Src homology 2 domain, and potential tyrosine phosphorylation sites with APS and SH-2B. It belongs to a family of adaptor proteins implicated in integration and regulation of multiple signaling events (Huang et al., 1995; Takaki et al., 1997; Yokouchi et al., 1997; Li et al., 2000; Ahmed and Pillay, 2003) and has also been suggested to act as a negative regulator in the stem cell factor (SCF)–c-Kit signaling pathway (Takaki et al., 2000, 2002).In another category of regenerative medicine, bone formation and regeneration has been extensively researched to meet clinical demand. A biologically optimal process of fracture repair results in the restoration of normal structure and function in the injured skeletal tissue. Although most fractures heal within a certain time period with callus formation that bridges the fracture gap while bone repair takes place, a large number of patients with fractures lose valuable time because of disability or confinement, leading to a loss of productivity and income. Moreover, a significant amount (5–10%) of fractures fail to heal and result in delayed union or persistent nonunion (Marsh, 1998; Rodriguez-Merchan and Forriol, 2004). Among various causes of failed bone formation and remodeling, inappropriate neoangiogenesis is considered to be a crucial factor (Harper and Kalgsbrun, 1999; Colnot and Helms, 2001). Notably, appropriate vasculogenesis by BM endothelial progenitor cells (EPCs; Asahara et al., 1997) is emerging as a prerequisite for bone development and regeneration, and there appears to be a developmental reciprocity between endothelial cells (ECs) and osteoblasts (OBs; Karsenty and Wagner, 2002). We have recently proved a pathophysiological role and contribution of murine BM-derived Sca1⁺Lin⁻ (SL) cells, HSC/EPC-enriched fraction, for bone healing (Matsumoto et al., 2008). Another group has also reported the increase of CD34⁺/AC133⁺ cells in peripheral blood (PB) of patients with fracture, suggesting the contribution of PB EPCs to bone healing (Laing et al., 2007). However, previous studies have demonstrated that the majority of callus-formed cells in fracture were derived from the periosteum rather than from PB (Nakazawa et al., 2004), indicating a minor contribution of BM-derived cells to fracture healing. Moreover, periosteal cells, but not endosteal BM cells, have recently been shown to be competent to produce fracture callus (Colnot, 2009). Therefore, emerging the concept of enhanced osteogenesis/angiogenesis by HSCs/EPCs, one of the novel factors responsible for stem/progenitor cell mobilization from BM, that is Lnk, attracted our research interests to develop therapeutic strategy using circulating EPCs for bone fracture.SCF has already been reported to stimulate proliferation and differentiation of HSCs (Broudy, 1997) and mobilize HSCs/EPCs into PB (Mauch et al., 1995; Takahashi et al., 1999) by binding with cKit. Thus, we have investigated the hypothesis that a lack of Lnk signaling, dependent on the SCF–cKit signaling pathway, enhanced the regenerative response via vasculogenesis and osteogenesis in fracture healing by HSC/EPC mobilization and recruitment to sites of fracture in Lnk-deficient mice. In our series of experiments, we showed that a negatively controlled Lnk system contributed to a favorable environment for fracture healing by enhancing vasculogenesis/angiogenesis and osteogenesis via activation of SCF–cKit signaling pathway, which leads to prompt recovery from fracture. In contrast, cKit expression was observed in several tissues and cells, including OBs (Bilbe et al., 1996).This is the first study showing interaction between the Lnk system and fracture healing that provides a new insight into negatively controlling the Lnk system not only to promote an environment conducive to vasculogenesis/angiogenesis and osteogenesis but also to up-regulate the potential of OB terminal differentiation so that fractures can promptly heal. Therefore, negatively regulating the Lnk system has important implications for the formulation of new therapeutic strategies to enhance bone repair.     

A useful procedure for observing the cervical esophagus via the hypopharynx

Objective

The aim of the study was to evaluate upper gastrointestinal endoscopy with movable over tube (i.e., the movable over tube method) for observing the hypopharynx to cervical esophagus, for use in treatment, and to determine its safety.

Methods

The study population consisted of 28 patients (23 men, 5 women; a mean age of 66.6 years old; age range of 50–80 years old). The patients consisted of nine cases of globus sensation, eight cases of hypopharyngeal cancer (post-chemoradiotherapy), three cases of hypopharyngeal cancer (untreated), two cases of hoarseness, two cases of unknown primary carcinoma, two cases of foreign body, one case of esophageal cancer, and one case of dysphagia. We used upper gastrointestinal endoscopy with movable over tube to examine the hypopharynx to the cervical esophagus in subjects.

Results

With the movable over tube method, which was performed under pharyngeal surface anesthesia and an infusion of diazepam (5–10 mg/kg body weight), one could observe from the hypopharynx to cervical esophagus without any blind spots. There were no complications after the examination.

Conclusions

The results suggest that the movable over tube method is an easy, useful, and safe method to observe the region from the hypopharynx to the cervical esophagus.     

Inner ear pathology of alpha-galactosidase A deficient mice,a model of Fabry disease

Objective

Fabry disease is characterized by genetic alpha-galactosidase A deficiency, resulting in accumulation of glycolipids (GL-3) and tissue damage. Hearing loss is also common and attributed to GL-3 accumulation in the inner ear. The only reported histological studies dealt with murine and human specimens. Accordingly, histopathological studies of the cochlea were performed on an alpha-galactosidase A deficient murine model of Fabry disease, using C57BL6/J mice as the controls.

Methods

The hearing ability was evaluated using the ABR threshold, while cochlear specimens were observed light microscopically and ultrathin temporal bone sections by TEM.

Results

HE staining showed no accumulation of GL-3 or abnormal cochlear morphology in the alpha-galactosidase A deficient mice, but toluidine blue staining and TEM revealed GL-3 accumulation in the stria vascularis and kidney. No GL-3 accumulation was detected in the C57BL6/J controls by either HE staining or TEM. The alpha-galactosidase A deficient mice and the controls showed no clear differences in the ABR threshold (hearing acuity), but for older animals the threshold was higher in the C57BL6/J controls.

Conclusion

In summary, although the alpha-galactosidase A deficient mice showed no clear hearing loss, GL-3 accumulation was demonstrated in the cochlea.     

Hemoglobin-Vesicles as Oxygen Carriers : Influence on Phagocytic Activity and Histopathological Changes in Reticuloendothelial System

Hemoglobin-vesicles (HbV) have been developed for use as artificial oxygen carriers (particle diameter, 250 nm) in which a purified Hb solution is encapsulated with a phospholipid bilayer membrane. The influence of HbV on the reticuloendothelial system was studied by carbon clearance measurements and histopathological examination. The HbV suspension ([Hb] = 10 g/dl) was intravenously infused in male Wistar rats at dose rates of 10 and 20 ml/kg, and the phagocytic activity was measured by monitoring the rate of carbon clearance at 8 hours and at 1, 3, 7, and 14 days after infusion. The phagocytic activity transiently decreased one day after infusion by about 40%, but it recovered and was enhanced at 3 days, showing a maximum of about twice the quiescent level at 7 days, and then returned to the normal value at 14 days. The initial transient decreased activity indicates a partly, but not completely, suppressed defensive function of the body. The succeeding increased phagocytic activity corresponds to the increased metabolism of HbV. The histopathological examination with anti-human Hb antibody, hematoxylin/eosin, and oil red O stainings showed that HbV was metabolized within 7 days. Hemosiderin was very slightly confirmed with Berlin blue staining at 3 and 7 days in liver and spleen, though they completely disappeared at 14 days, indicating that the heme metabolism, excretion or recycling of iron proceeded smoothly and iron deposition was minimal. Electron microscopic examination of the spleen and liver tissues clearly demonstrated the particles of HbV with a diameter of about 1/40 of red blood cells in capillaries, and in phagosomes as entrapped in the spleen macrophages and Kupffer cells one day after infusion. The vesicular structure could not be observed at 7 days. Even though the infusion of HbV modified the phagocytic activity for 2 weeks, it does not seem to cause any irreversible damage to the phagocytic organs. These results offer important information for evaluating the safety issues of HbV for clinical use.     

Covered Gianturco stent for tracheal stricture: application of polychlorovinylidene and polyurethane as covering materials

The aim of this study was to assess the efficacy and safety of thin membranes of polychlorovinylidene (PCV) or polyurethane (PU) as covering materials for Gianturco stents in the treatment of severe tracheal stricture caused by intraluminal tumor. Manufactured Gianturco stents covered with PCV or PU membrane were used to treat six malignant and one benign tracheal stricture. The initial results, complications, clinical follow-up, bronchoscopic findings, and three autopsy microscopic examinations were reviewed. Informed consent was obtained after the nature of the treatment had been fully explained before every procedure. The stents successfully dilated the tracheal strictures, providing immediate relief of respiratory symptoms in all patients with no major complications. During the follow-up period, the covering materials prevented tumor ingrowth until death or intraluminal granuloma formation. Autopsies proved that no histological change occurs in the tracheal mucosa in response to the presence of PCV or PU; however, ulcer formation occurred in one patient and penetration of the stent struts into the tracheal wall in two. Bloody sputum with ulcer formation, minimal granuloma formation at the distal end of the stent, and abnormal bacterial load in the sputum were long-term complications. The Gianturco stent covered with PCV or PU membrane is a useful option as a palliative treatment for malignant and an emergent salvage for benign tracheal stricture, because both materials are thinner and less voluminous than the others. However, the indications for its use are limited to patients with poor prognoses, because hemoptysis, granuloma formation, and bacterial propagation remain problematic.     

Low-concentration Lidocaine Rapidly Inhibits Axonal Transport in Cultured Mouse Dorsal Root Ganglion Neurons

Background: Axonal transport plays a critical role in supplying materials for a variety of neuronal functions such as morphogenetic plasticity, synaptic transmission, and cell survival. In the current study, the authors investigated the effects of the analgesic agent lidocaine on axonal transport in neurites of cultured mouse dorsal root ganglion neurons. In relation to their effects, the effects of lidocaine on the growth rate of the neurite were also examined.

Methods: Isolated mouse dorsal root ganglion cells were cultured for 48 h until full growth of neurites. Video-enhanced microscopy was used to observe particles transported within neurites and to measure the neurite growth during control conditions and in the presence of lidocaine.

Results: Application of 30 [mu]m lidocaine immediately reduced the number of particles transported in anterograde and retrograde axonal directions. These effects were persistently observed during the application (26 min) and were reversed by lidocaine washout. The inhibitory effect was dose-dependent at concentrations from 0.1 to 1,000 [mu]m (IC50= 10 [mu]m). In Ca2+-free extracellular medium, lidocaine failed to inhibit axonal transport. Calcium ionophore A23187 (0.1 [mu]m) reduced axonal transport in both directions. The inhibitory effects of lidocaine and A23187 were abrogated by 10 [mu]m KN-62, a Ca2+-calmodulin-dependent protein kinase II inhibitor. Application of such low-concentration lidocaine (30 [mu]m) for 30 min reduced the growth rate of neurites, and this effect was also blocked by KN-62.     

The cytotoxicity of cyclophosphamide is enhanced in combination with monascus pigment

Monascus pigment is derived from red-mold rice fermented by monascus purpureus and utilized as a natural coloring agent and natural food additive in East Asia. Monascus pigment works as a radical scavenger. Some antioxidant combine cancer chemo­therapy to protect normal tissue because chemotherapy induce side effect for normal tissue. This combination therapy can attenuate the cytotoxicity of anti­cancer drugs by antioxidants effects. However, the effect of this combination therapy for cancer cells dose not investigate enough. In this study, we investigated the combination effect of anti­oxidants and anti­cancer drugs. We selected an anti­oxidant as monascus pigment and following four anti­cancer drugs: doxorubicin, tamoxifen, paclitaxicel, and cyclophosphamide. Combination treatment with monascus pigment and cyclophosphamide enhanced the cytotoxicity of cyclophosphamide. Moreover, this combination treatment accelerated apoptosis. The spot on TLC assay board of the monascus pigment and cyclophosphamide mixture is different from the spot of monascus pigment alone and cyclophosphamide alone. The interaction between monascus pigment and cyclo­phosphamide can produce some cytotoxicity compounds or accelerate intracellular cyclophosphamide accumulation. Hence, we concluded that the interaction of both cyclophosphamide and monascus pigment involved enhancement of cyclophosphamide cytotoxicity.