Translational possibility of [18 F]Mefway to image serotonin 1A receptors in humans: Comparison with [18 F]FCWAY in rodents

PURPOSE

To compare the cerebral uptake and binding potential of [¹⁸ F]FCWAY and [¹⁸ F]Mefway in the rodent to assess their potential for imaging serotonin 1A (5-HT_1A ) receptors.

MATERIALS AND METHODS

In vitro liver microsomal studies were performed to evaluate the degree of defluorination. Dynamic positron emission tomography (PET) studies were then conducted for 2 h with or without an anti-defluorination agent. The regions of interest were the hippocampus and frontal cortex (5-HT_1A target regions) and the cerebellum (5-HT_1A nontarget region). The in vivo kinetics of the radioligands were compared based on the brain uptake values and target-to-nontarget ratio. We also performed a comparison of binding potential (BP_ND ) as a steady-state binding parameter. Finally, binding affinities to 5-HT_1A receptors were assessed in Chinese hamster ovary cells (CHO-K1) cells expressing human recombinant 5-HT_1A receptors.

RESULTS

The radiochemical yield of [¹⁸ F]Mefway was slightly higher than that of [¹⁸ F]FCWAY (19 vs. 15%). With regard to metabolic stability against defluorination, both compounds exhibited similar stability in rat liver microsomes, but [¹⁸ F]Mefway displayed higher stability in the human microsome (defluorination ratio at 30 min: 32 vs. 29 in rat liver microsomes, 31 vs. 64 in human liver microsomes for [¹⁸ F]Mefway and [¹⁸ F]FCWAY, respectively). There were no significant differences in brain uptake, the target-to-nontarget ratios, and the BP_ND (at hippocampus, peak brain uptakes: 6.9 vs. 8.5, target-to-nontarget ratios: 6.9 vs. 8.5, BP_ND : 5.2 vs. 6.2 for [¹⁸ F]Mefway and [¹⁸ F]FCWAY). The binding affinity of [¹⁸ F]Mefway was considerably higher than that of [¹⁸ F]FCWAY (IC₅₀ : 1.5 nM vs. 2.2 nM).

CONCLUSION

[¹⁸ F]Mefway exhibits favorable characteristics compared to [¹⁸ F]FCWAY in rodents, and may be a promising radioligand for use in human subjects. Synapse 68:595-603, 2014. © 2014 Wiley Periodicals, Inc.

Acute physical stress induces the alteration of the serotonin 1A receptor density in the hippocampus

Stress affects the serotonergic system, which is associated with depression. Previous research has showed that chronic stress causes the deactivation of the limbic system. However, the influence of the acute physical stress on the serotonergic system in vivo was primarily unclear. The purpose of this research is to elucidate the effects of the acute physical stress in vivo using PET. For quantification of the 5-HT1A receptors in the brain, we measured [(18)F]Mefway uptake in the two experiment groups (control and despair rats). The despair group was subjected to the external stressful situation (i.e., forced swimming) and total duration time of immobility, refers to the despair severity, and was analyzed. In the intercomparison experiment, the resulting PET images of [(18)F]Mefway in the despair rat displayed a significant reduction of radioactivity in the hippocampus (HP) compared with the control. The nondisplaceable binding potential (BPND ) refers to the ratio of the concentration of radioligand in the receptor-rich region (i.e., HP) to the concentration of that in the receptor-free region (i.e., cerebellum). The hippocampal uptake and the BPND in the despair group were respectively about 25 and 18% lower than those of the control group. The ratio of specific binding to nonspecific binding in the despair group was 18% lower than that of the control. In the intracomparison experiments, the BPND and immobility in the despair group showed a strong negative correlation. Taken together, the data illustrates that an acute physical stress induces the change in the serotonergic system that correlates with the behavioral despair.

Curvilinear transformation of z-shaped upper lip scar by diamond-shaped excision in secondary cleft lip deformities: a photogrammetric evaluation

Purpose : The visible Z-shaped upper lip scar that occurs after the Tennison and Randall triangular flap technique remains a cleft stigma. Herein, we present our curvilinear transformation technique for the Z-shaped upper lip scar by diamond-shaped excision and evaluate the results using photogrammetric analyses. Patients and Methods : From 1997 to 2006, 23 patients with secondary cleft lip deformity with the visible Z-shaped upper lip scar underwent correction with the technique. The scar was excised in the diamond shape above the muscle. After curvilinear closure, the elongated length of the upper lip was excised just below the nostril sill, as the measured Cupid's bow height discrepancy. The result was assessed by the authors' standardized photogrammetry technique. Results : There was a statistically significant decrease between the preoperative central limb of the Z-shaped scar and the width of the postoperative curvilinear upper lip scar. The pre- and postoperative Cupid's bow height differences were not statistically significant. Conclusions : The curvilinear transformation of the Z-shaped scar is an efficient procedure that provides (1) a significant decrease in the width of an upper lip scar to make it less conspicuous, (2) incorporation of the scar into the philtral column, (3) a biconcave natural philtral column shape in frontal view, and (4) formation of the natural concave philtral contour in profile view.

Anthocyanins from black soybean seed coat enhance wound healing

Anthocyanins are known to have antioxidant and antiinflammatory effects. We hypothesized that anthocyanins would enhance wound healing in Sprague-Dawley rats. The purpose of this study was to evaluate our hypothesis and investigate the mechanism of wound healing enhancement. The cytoprotective effect of an immortalized epidermal keratinocyte cell line (HaCaT) and human neonatal dermal fibroblasts in response to various concentrations of anthocyanins was determined. Vascular endothelial growth factor (VEGF) and thrombospondin 1 (TSP1) of HaCaT were measured by Western blot analysis. Anthocyanins were applied to the wounds in rats, and the healing ratio was calculated. Tissue VEGF, TSP1, CD31, nuclear factor-κB, and phosphorylation of IκBα were measured. The viability of the HaCaT cell line and human neonatal dermal fibroblasts increased under cytotoxicity by H2O2 in the anthocyanin-treated groups. The VEGF in the anthocyanin-treated groups increased, whereas TSP1 decreased. Wounds in the experimental groups healed faster, and VEGF and CD31 increased in the experimental groups, whereas TSP1 decreased. Anthocyanins inhibited the translocation of nuclear factor-κB (p65) from cytosol to nucleus and also prevented the phosphorylation of IκBα. Anthocyanins enhance wound healing through a cytoprotective effect, enhancement of angiogenesis, and an antiinflammatory effect.

Effect of Recombinant Human Bone Morphogenetic Protein-2 and Adipose Tissue-Derived Stem Cell on New Bone Formation in High-Speed Distraction Osteogenesis

PURPOSE

The effects of recombinant human bone morphogenetic protein-2 (rhBMP-2) and osteogenically differentiated adipose tissue-derived stem cells (ADSC) on new bone formation in high-speed distraction osteogenesis of adult rabbit cranium were investigated.

MATERIALS AND METHODS

A total of 41 adult rabbits were used in the study. Distraction began after a 5-day latency period at a rate of 1.5 mm twice a day until 10-mm length gain was obtained both in the control group, where a bone defect was induced, and in the experimental group, in which ADSC (group A), rhBMP-2 (group B), or both (group C) were injected in the distraction gap after distraction. At 4, 8, and 12 weeks after distraction, computed tomography analysis was done to determine the bone defect dimension and bone mineral density (BMD), while histologic examination was also done to calculate bone formation ratio.

RESULTS

Bone defect dimension significantly decreased in groups B and C, compared with the control group, at 4 and 12 weeks after distraction. BMD was significantly increased in groups B and C at 4 weeks. On histologic examination, bone formation ratio was significantly increased in group C only at 12 weeks.

CONCLUSION

This study suggests that the use of rhBMP-2 in combination with or without ADSC is helpful to promote bone regeneration in high-speed distraction osteogenesi s of adult rabbit cranium.

Prognostic significance of pretreatment ¹⁸F-FDG PET/CT in patients with relapsed/refractory B-cell non-Hodgkin's lymphoma treated by radioimmunotherapy using ¹³¹I-rituximab

AIMS

It was the aim of this paper to identify prognostic factors in patients with relapsed or refractory B-cell non-Hodgkin's lymphomas, treated by radioimmunotherapy (RIT) with radioiodinated human/murine chimeric anti-CD20 monoclonal antibody rituximab (¹³¹I-rituximab).

METHODS

Twenty-four patients were enrolled prospectively and were treated with unlabeled rituximab 70 mg and a therapeutic activity (median 7.3 GBq) of ¹³¹I-rituximab. Contrast-enhanced ¹⁸F-FDG PET/CT scans were performed before and after 1 month of RIT. Tumor sizes and maximum standardized uptake values (SUVmax) of scans were measured.

RESULTS

Four of the 24 patients survived. High SUVmax in a pretreatment scan was found to be related to poorer overall survival (OS) and progression-free survival (p = 0.04 and 0.02, respectively). Furthermore, a large tumor size in a pretreatment scan was associated with poorer OS but not with progression-free survival (p < 0.01 and p = 0.07, respectively). By multivariate analyses, a high SUVmax, a large tumor size in a pretreatment scan and diffuse large B-cell lymphoma histology were significantly associated with poorer OS [p = 0.04/hazard ratio (HR) = 3.54, p < 0.01/HR = 5.52, and p = 0.02/HR = 3.38, respectively).

CONCLUSION

SUVmax and tumor size determined by a pretreatment ¹⁸F-FDG PET/CT result as significant predictors of OS in patients with relapsed or refractory B-cell non-Hodgkin's lymphoma treated by RIT.

Mycobacterium marinum infection in Drosophila melanogaster for antimycobacterial activity assessment

OBJECTIVES

The major advantages of Drosophila melanogaster are a well-characterized immune system and high degree of susceptibility to tuberculosis caused by Mycobacterium marinum. The D. melanogaster-M. marinum infection model is gaining momentum as a screening tool because it is genetically amenable, low priced, rapid, technically convenient and ethically acceptable. In this context, the aim of this study was to develop a new, effective D. melanogaster-M. marinum in vivo efficacy model for antimycobacterial drug discovery.

METHODS

D. melanogaster were challenged with intra-abdominal injections of M. marinum and infected flies were fed with a fly medium containing isoniazid, rifampicin, ethambutol, pyrazinamide, amikacin, dinitrobenzamide or ampicillin dissolved in DMSO at different concentrations (0, 100 and 500 mg/L). Bacterial dissemination in flies was monitored by fluorescence microscopy/cfu counts and a fly survival curve was plotted.

RESULTS

The D. melanogaster-M. marinum model allowed assessment of the effectiveness of antibiotic treatment not only with conventional drugs, but also with newly discovered antimycobacterial agents. Rifampicin, dinitrobenzamide, amikacin and isoniazid effectively extended the life span of infected flies and ethambutol showed slightly improved survival. However, M. marinum infection was not cured by ampicillin or pyrazinamide.

CONCLUSIONS

This D. melanogaster-M. marinum infection/curing methodology may be valuable in the rapid evaluation of the activity of new antimycobacterial agents in drug discovery.

Anti-inflammatory effects of anthocyanins from black soybean seed coat on the keratinocytes and ischemia-reperfusion injury in rat skin flaps

Ischemia-reperfusion injury is a phenomenon that occurs when tissues are subjected to ischemia for a variable period of time, and then reperfused. Inflammatory reaction has been implicated as one of the most important mechanism of ischemia-reperfusion injury. The purpose of this study was to evaluate the anti-inflammatory effects of anthocyanins from black soybean seed coat on keratinocytes in vitro and ischemia-reperfusion injury in vivo. We investigated the inhibition, by anthocyanins, of the expression of various inflammatory genes associated with ischemia-reperfusion injury in the tumor necrosis factor-alpha-treated (TNF-α) immortalized epidermal keratinocyte cell line (HaCaT). We also investigated the effects of anthocyanins on the survival of skin flaps after ischemia-reperfusion injury in the rats. According to Western blot analysis and a luciferase activity assay, anthocyanins inhibited TNF-α-induced intercellular adhesion molecule-1 and cyclooxygenase-2 (COX-2) levels through the NF-κB-dependent pathway. Administration of anthocyanins (50 and 100 mg/kg) significantly improved the flap area survival in the 10-hour ischemic model from 62% to 74.5% and 83%, respectively (P = 0.001). The related cytokines in skin flap also changed as the same pattern as in vitro. Our results indicate that anthocyanins from black soybean seed coat had anti-inflammatory effects on the HaCaT cell line and increase the survival of skin flaps through anti-inflammatory properties against ischemia-reperfusion injury.

Effectiveness of [(124)I]-PET/CT and [(18)F]-FDG-PET/CT for localizing recurrence in patients with differentiated thyroid carcinoma

Although the prognosis of patients with differentiated thyroid carcinoma (DTC) is generally encouraging, a diagnostic dilemma is posed when an increasing level of serum thyroglobulin (Tg) is noted, without detection of a recurrent tumor using conventional imaging tools such as the iodine-131 whole-body scanning (the [(131)I] scan) or neck ultrasonography (US). The objective of the present study was to evaluate the diagnostic value of [(124)I]-PET/CT and [(18)F]-FDG-PET/CT in terms of accurate detection of both iodine- and non-iodine-avid recurrence, compared with that of conventional imaging such as the [(131)I] scan or neck ultrasonography (US). Between July 2009 and June 2010, we prospectively studied 19 DTC patients with elevated thyroglobulin levels but who do not show pathological lesions when conventional imaging modalities are used. All involved patients had undergone total thyroidectomy and radioiodine (RI) treatment, and who had been followed-up for a mean of 13 months (range, 6-21 months) after the last RI session. Combined [(18)F]-FDG-PET/CT and [(124)I]-PET/CT data were evaluated for detecting recurrent DTC lesions in study patients and compared with those of other radiological and/or cytological investigations. Nine of 19 patients (47.4%) showed pathological [(18)F]-FDG (5/19, 26.3%) or [(124)I]-PET (4/19, 21.1%) uptake, and were classed as true-positives. Among such patients, disease management was modified in six (66.7%) and disease was restaged in seven (77.8%). In particular, the use of the described imaging combination optimized planning of surgical resection to deal with locoregional recurrence in 21.1% (4/19) of patients, who were shown to be disease-free during follow-up after surgery. Our results indicate that combination of [(18)F]-FDG-PET/CT and [(124)I]-PET/CT affords a valuable diagnostic method that can be used to make therapeutic decisions in patients with DTC who are tumor-free on conventional imaging studies but who have high Tg levels.

Evaluation of dopamine transporters and D2 receptors in hemiparkinsonian rat brains in vivo using consecutive PET scans of [18F]FPCIT and [18F]fallypride

The aim of this study was to investigate dopaminergic function in unilaterally lesioned 6-OHDA rats by dual PET radioligands: [(18)F]FPCIT (a dopamine transporter imaging radioligand) and [(18)F]fallypride (a dopamine D2 receptors imaging radioligand). As a result, the brain uptake of [(18)F]FPCIT was significantly reduced and that of [(18)F]fallypride was increased in the ipsilateral striatum (lesion side) of the 6-OHDA rats. These findings implicated that dopamine transporter is down-regulated and dopamine D2 receptor is up-regulated in this hemiparkinsonian rat model.

Regeneration of peripheral nerves by transplanted sphere of human mesenchymal stem cells derived from embryonic stem cells

In cell therapy, the most important factor for therapeutic efficacy is the stable supply of cells with best engraftment efficiency. To meet this requirement, we have developed a culture strategy such as three-dimensional sphere of human embryonic stem cell-derived mesenchymal stem cells (hESC-MSCs) in serum-free medium. To investigate the in vivo therapeutic efficacy of hESC-MSC spheres in nerve injury model, we transected the sciatic nerve in athymic nude mice and created a 2-mm gap. Transplantation of hESC-MSC as sphere repaired the injured nerve significantly better than transplantation of hESC-MSC as suspended single cells in regard to 1) nerve conduction (sphere; 28.81 ± 3.55 vs. single cells; 18.04 ± 2.10, p < 0.05) and 2) susceptibility of nerve stimulation at low voltage (sphere; 0.38 ± 0.08 vs. single cells; 0.66 ± 0.11, p < 0.05) at 8 weeks. Recovery after sphere transplantation was near-complete when compared with the data of normal control (sphere 28.81 ± 3.55 vs normal 32.62 ± 2.85 in nerve conduction : sphere 0.38 ± 0.08 vs normal 0.36 ± 0.67 in susceptibility of nerve stimulation, no significant difference, respectively). Recovery in function of the injured nerve was well corroborated by the histologic evidence of regenerated nerve. In the mechanistic analysis, the supernatant of sphere-forming hESC-MSC contains hepatocyte growth factor and insulin-like growth factor-binding protein-1 significantly more than the supernatant of the single cells of hESC-MSC has, which might be the key factors for the improved engraftment efficiency and greater regeneration of injured peripheral nerve.

Direct and indirect contribution of human embryonic stem cell-derived hepatocyte-like cells to liver repair in mice

BACKGROUND & AIMS

Many studies of embryonic stem cells have investigated direct cell replacement of damaged tissues, but little is known about how donor cell-derived signals affect host tissue regeneration. We investigated the direct and indirect roles of human embryonic stem cell-derived cells in liver repair in mice.

METHODS

To promote the initial differentiation of human embryonic stem cells into mesendoderm, we activated the β-catenin signaling pathway with lithium; cells were then further differentiated into hepatocyte-like cells. The differentiated cells were purified by indocyanine green staining and laser microdissection and characterized by immunostaining, polymerase chain reaction, biochemical function, electron microscopy, and transplantation analyses. To investigate indirect effects of these cells, secreted proteins (secretomes) were analyzed by a label-free quantitative mass spectrometry. Carbon tetrachloride was used to induce acute liver injury in mice; cells or secreted proteins were administered by intrasplenic or intraperitoneal injection, respectively.

RESULTS

The differentiated hepatocyte-like cells had multiple features of normal hepatocytes, engrafted efficiently into mice, and continued to have hepatic features; they promoted proliferation of host hepatocytes and revascularization of injured host liver tissues. Proteomic analysis identified proteins secreted from these cells that might promote host tissue repair. Injection of the secreted proteins into injured livers of mice promoted significant amounts of tissue regeneration without cell grafts.

CONCLUSIONS

Hepatocyte-like cells derived from human embryonic stem cells contribute to recovery of injured liver tissues in mice, not only by cell replacement but also by delivering trophic factors that support endogenous liver regeneration.

Change in upper lip height and nostril sill after alveolar bone grafting in unilateral cleft lip alveolus patients

INTRODUCTION

Alveolar bone grafting is known to reduce nasal asymmetry by supporting a defective alar base and a sunken nostril. However, there are no studies which include details of changes to the upper lip with appropriate measurements. The purpose of this study was to measure the change in the upper lip height and nostril sill after alveolar bone grafting, using photogrammetry.

MATERIALS AND METHODS

The study included 18 unilateral cleft lip alveolus (UCLA) patients who were diagnosed with unilateral cleft lip and palate (mean age, 9.87 years). The patients underwent alveolar bone grafting with iliac bone between June 2007 and June 2008. The average follow-up period was 16.6 months. The average bone graft volume was 2.39 cm(3). We obtained photographs of the frontal, lateral and basal views using standardised photographic techniques. We defined 14 landmarks and measured the distance of 11 points (distance items) for the determination of upper lip height, upper lip projection and nostril sill elevation. We defined the proportion index as the ratio of the cleft side to non-cleft side or reference line (R). We compared the preoperative proportion index with the postoperative proportion index for each distance items.

RESULTS

The height of the upper lip increased significantly in four of five distance items. The projection of the upper lip was more prominent, but it was not statistically significant. The nostril sill was significantly elevated in all four distance items.

CONCLUSION

The height of the upper lip was elongated and the nostril sill was elevated after alveolar bone grafting in UCLA patients.