Reduced P-glycoprotein recognition of a radioiodine-labeled phosphonium cation by stilbenylation for mitochondrial membrane potential based-imaging.

The accumulation of radiolabeled phosphonium cations in cells is dependent on the mitochondrial membrane potential (MMP). However, the efflux of these cations from tumor cells via P-glycoprotein (P-gp) limits their clinical application as MMP-based imaging tracers. In the present study, we designed (E)-diethyl-4-[125I]iodobenzyl-4-stilbenylphosphonium ([125I]IDESP), which contains a stilbenyl substituent, as a P-gp inhibitor to reduce P-gp recognition, and evaluated its biological properties in comparison with 4-[125I]iodobenzyl dipropylphenylphosphonium ([125I]IDPP). The in vitro cellular uptake ratio of [125I]IDESP in P-gp expressing K562/Vin cells to the parent (P-gp negative) K562 cells was significantly higher than that of [125I]IDPP. The efflux rate of [125I]IDESP was not significantly different between K562 and K562/Vin, while [125I]IDPP was rapidly effluxed from K562/Vin compared with K562, and the efflux of [125I]IDPP from K562/Vin was inhibited by the P-gp inhibitor, cyclosporine A. The cellular uptake of [125I]IDESP was well correlated with the MMP levels. These results suggested that [125I]IDESP was accumulated in cells depending on the MMP levels, without being effluxed via P-gp, while [125I]IDPP was rapidly effluxed from the cells via P-gp. Despite having suitable in vitro properties for MMP-based imaging, [125I]IDESP showed rapid blood clearance and lower tumor accumulation than [125I]IDPP. Improvement in the normal tissue distribution of [125I]IDESP is required to develop an agent for use in in vivo MMP-based tumor imaging.

COVID-19 in a Hairy Cell Leukemia Patient: A Rare Case Report.

The detailed clinical course of coronavirus disease 2019 (COVID-19) in patients with hairy cell leukemia (HCL) is rarely reported. We report the first case of HCL diagnosed with prolonged pancytopenia after COVID-19 infection in Japan. We describe the case of a 56-year-old man who was diagnosed with COVID-19. Computed tomography revealed ground-glass opacities in the bilateral lung lobes as well as splenomegaly. Remdesivir and dexamethasone were administered for the treatment of COVID-19. Since the pancytopenia persisted, bone marrow examination was performed, and he was diagnosed with HCL. Although pancytopenia can occur with COVID-19 alone, clinicians should be alerted regarding the presence of hematologic malignancies in patients in whom pancytopenia persists after COVID-19 treatment or in those with splenomegaly. Further, the condition of all previously reported patients with COVID-19 associated with HCL was severe enough to require mechanical ventilation. This is the first case in which the disease was not severe. The interleukin-6 (IL-6) level was lower in this case than in previous cases, suggesting that racial differences in IL-6 production may have contributed to COVID-19 severity.

Measurement of Hepatic CYP3A4 and 2D6 Activity Using Radioiodine-Labeled O-Desmethylvenlafaxine.

Drug metabolizing enzyme activity is affected by various factors such as drug-drug interactions, and a method to quantify drug metabolizing enzyme activity in real time is needed. In this study, we developed a novel radiopharmaceutical for quantitative imaging to estimate hepatic CYP3A4 and CYP2D6 activity. Iodine-123- and 125-labeled O-desmethylvenlafaxine (123/125I-ODV) was obtained with high labeling and purity, and its metabolism was found to strongly involve CYP3A4 and CYP2D6. SPECT imaging in normal mice showed that the administered 123I-ODV accumulated early in the liver and was excreted into the gallbladder, as evaluated by time activity curves. In its biological distribution, 125I-ODV administered to mice accumulated early in the liver, and only the metabolite of 125I-ODV was quickly excreted into the bile. In CYP3A4- and CYP2D6-inhibited model mice, the accumulation in bile decreased more than in normal mice, indicating inhibition of metabolite production. These results indicated that imaging and quantifying the accumulation of radioactive metabolites in excretory organs will aid in determining the dosages of various drugs metabolized by CYP3A4 and CYP2D6 for individualized medicine. Thus, 123/125I-ODV has the potential to direct, comprehensive detection and measurement of hepatic CYP3A4 and CYP2D6 activity by a simple and less invasive approach.

An attempt at estrus detection in cattle by continuous measurements of ventral tail base surface temperature with supervised machine learning.

We aimed to determine the effectiveness of estrus detection based on continuous measurements of the ventral tail base surface temperature (ST) with supervised machine learning in cattle. ST data were obtained through 51 estrus cycles on 11 female cattle (six Holsteins and five Japanese Blacks) using the tail-attached sensor. Three estrus detection models were constructed with the training data (n = 17) using machine learning techniques (random forest, artificial neural network, and support vector machine) based on 13 features extracted from sensing data (indicative of estrus-associated ST changes). Estrus detection abilities of the three models on test data (n = 34) were not statistically different among models in terms of sensitivity and precision (range 50.0% to 58.8% and 60.6% to 73.1%, respectively). The relatively poor performance of the models might indicate the difficulty of separating estrus-associated ST changes from estrus-independent fluctuations in ST.

BELL1-like homeobox genes regulate inflorescence architecture and meristem maintenance in rice.

Inflorescence architecture is diverse in angiosperms, and is mainly determined by the arrangement of the branches and flowers, known as phyllotaxy. In rice (Oryza sativa), the main inflorescence axis, called the rachis, generates primary branches in a spiral phyllotaxy, and flowers (spikelets) are formed on these branches. Here, we have studied a classical mutant, named verticillate rachis (ri), which produces branches in a partially whorled phyllotaxy. Gene isolation revealed that RI encodes a BELL1-type homeodomain transcription factor, similar to Arabidopsis PENNYWISE/BELLRINGER/REPLUMLESS, and is expressed in the specific regions within the inflorescence and branch meristems where their descendant meristems would soon initiate. Genetic combination of an ri homozygote and a mutant allele of RI-LIKE1 (RIL1) (designated ri ril1/+ plant), a close paralog of RI, enhanced the ri inflorescence phenotype, including the abnormalities in branch phyllotaxy and rachis internode patterning. During early inflorescence development, the timing and arrangement of primary branch meristem (pBM) initiation were disturbed in both ri and ri ril1/+ plants. These findings suggest that RI and RIL1 were involved in regulating the phyllotactic pattern of the pBMs to form normal inflorescences. In addition, both RI and RIL1 seem to be involved in meristem maintenance, because the ri ril1 double-mutant failed to establish or maintain the shoot apical meristem during embryogenesis.

Renal Handling of 99mTc-Labeled Antibody Fab Fragments with a Linkage Cleavable by Enzymes on Brush Border Membrane.

The high and persistent renal radioactivity levels after injection of radiolabeled low-molecular-weight polypeptides constitute a significant problem for their diagnostic and therapeutic applications, especially when they are labeled with metallic radionuclides. To improve the renal radioactivity levels of technetium-99m (99mTc)-labeled Fab fragments, a mercaptoacetyltriglycine (MAG3)-based new bifunctional chelating agent with a cleavable glycyl-phenylalanyl-lysine (GFK) linkage, MAG3-GFK-suc-TFP, was designed, synthesized, and evaluated. 99mTc-labeled Fab was obtained by reacting MAG3-GFK-Fab conjugate with 99mTc-glucarate. The GFK linkage remained stable in plasma but was cleaved by enzymes on the renal brush border membrane. The comparative biodistribution studies with indium-111 (111In)-labeled Fab using SCN-CHX-A″-DTPA showed that while both radiolabeled Fabs exhibited similar elimination rates from the blood, [99mTc]Tc-MAG3-GFK-Fab registered much lower renal radioactivity levels from 30 min post-injection onward due to the release and subsequent urinary excretion of [99mTc]Tc-MAG3-Gly. However, [99mTc]Tc-MAG3-GFK-Fab showed an increase in the intestinal radioactivity levels with the time that was not observed with 111In-labeled Fab. The analysis of the intestinal contents suggested the redistribution of [99mTc]Tc-MAG3-Gly to the intestine. The retrospective comparison of [99mTc]Tc-MAG3-GFK-Fab with the radiolabeled Fabs so far prepared under the identical concept suggested that some portion of [99mTc]Tc-MAG3-Gly was generated after the coated vesicle formation and they were excreted into the blood, and subsequently redistributed in the intestine via hepatobiliary excretion. In conclusion, MAG3-GFK-suc-TFP provided 99mTc-labeled Fabs that exhibit low renal radioactivity shortly after injection by the post-labeling procedure. The present study indicated that, contrary to our earlier proposal, the generation of the radiometabolites would proceed not only during the internalization process of the parental antibody fragments but also after coated vesicle formation. This study also showed that the intracellular behaviors of radiometabolites played crucial roles in the elimination rates and the routes of the radioactivity from the kidney.

Transcriptional Corepressor ASP1 and CLV-Like Signaling Regulate Meristem Maintenance in Rice.

Stem cell homeostasis is maintained by the WUSCHEL-CLAVATA (WUS-CLV) negative feedback loop in Arabidopsis (Arabidopsis thaliana). In rice (Oryza sativa), FLORAL ORGAN NUMBER2 (FON2) functions in the negative regulation of stem cell proliferation, similar to Arabidopsis CLV3 In this study, through genetic enhancer analysis, we found that loss of function of ABERRANT SPIKELET AND PANICLE1 (ASP1), encoding an Arabidopsis TOPLESS (TPL)-like transcriptional corepressor, enhances the fon2 flower phenotype, which displayed an increase in floral organ number. In the fon2 asp1 double mutant, the inflorescence was severely affected, resulting in bifurcation of the main axis (rachis), a phenotype that has not previously been reported. The stem cells showed marked overproliferation in fon2 asp1, resulting in extreme enlargement and splitting of the inflorescence meristem. These results suggest that ASP1 and FON2 synergistically regulate stem cell maintenance in rice. Unexpectedly, genetic analysis indicated that TILLERS ABSENT1, the rice ortholog of WUS, is not involved in promoting stem cell proliferation in this meristem. Transcriptome analysis suggested that ASP1 and FON signaling negatively regulate a set of genes with similar functions, and they act on these genes in concert. Taken together, our results suggest that TPL-like corepressor activity plays a crucial role in meristem maintenance, and that stem cell proliferation is properly maintained via the cooperation of ASP1 and FON2.

Flow Cytometry-Based Photodynamic Diagnosis with 5-Aminolevulinic Acid for the Detection of Minimal Residual Disease in Multiple Myeloma.

Multiple myeloma is the cancer of plasma cells. Along with the development of new and effective therapies, improved outcomes in patients with multiple myeloma have increased the interest in minimal residual disease (MRD) monitoring. However, the considerable heterogeneity of immunophenotypic and molecular markers of myeloma cells has limited its clinical application. 5-Aminolevulinic acid (ALA) is a natural compound in the heme biosynthesis pathway. Following ALA treatment, tumor cells preferentially accumulate porphyrins because of the differential activities of aerobic glycolysis, known as Warburg effect. Among various porphyrins, protoporphyrine IX is a strong photosensitizer; thus, ALA-based photodynamic diagnosis has been widely used in various solid cancers. Here, the feasibility of flow cytometry-based photodynamic detection of MRD was tested in multiple myeloma. Among various human cell lines of hematological malignancies, including K562 erythroleukemia, Jurkat T-cell leukemia, Nalm6 pre-B cell leukemia, KG1a myeloid leukemia, and U937 monocytic leukemia, human myeloma cell line, KMS18, and OPM2 abundantly expressed ALA transporters, such as SLC36A1 and SLC15A2, and 1 mM ALA treatment for 24 h resulted in nearly 100% porphyrin fluorescence expression, which could be competitively inhibited by ALA transport with gamma-aminobutyric acid. Titration studies revealed that the lowest ALA concentration required to achieve nearly 100% porphyrin fluorescence in KMS18 cells was 0.25 mM, with an incubation period of 2 h. Under these conditions, incubation of primary peripheral blood mononuclear cells resulted in only 1.8 % of the cells exhibiting porphyrin fluorescence. Therefore, flow cytometry-based photodynamic diagnosis is a promising approach for detecting MRD in multiple myeloma.

Effects of lactoferrin on the viability and the encystment of Acanthamoeba trophozoites.

Lactoferrin (LF) is an iron-binding basic glycoprotein that has an antimicrobial effect against certain microbes. The purpose of this study is to evaluate the amoebicidal effect of bovine milk LF (bLF) against Acanthamoeba clinical-isolate trophozoites, which cause severe keratitis. Most of the risk factor for Acanthamoeba keratitis is from wearing soft contact lenses (SCLs). Acanthamoeba trophozoites were incubated in bovine LF (bLF) solution, and the ratios of viability and encystment were determined with microscopic analysis of cyst formation. The amoebicidal effect of bLF was assessed by Trypan blue assay. The ratios of viable cells in the presence of iron-free bLF (apo-bLF), native-bLF, and iron-saturated bLF (Fe-bLF) at the concentration of 10 µmol/L for 60 min were 7.7% ± 4.6%, 80.7% ± 10.1%, and 97.3% ± 1.5%, respectively. Apo-bLF showed potent amoebicidal effect against Acanthamoeba trophozoites, but Fe-bLF did not have this effect. After treating with apo-bLF, most dead cells were nonglobular forms of trophozoites but not cystic forms. Encystment of Acanthamoeba was assessed by the sarkosyl-calcofluor white assay. The encystment ratios treated with 0.5% propylene glycol (positive control) and 10 µmol/L apo-bLF for 24 h were 96.12% ± 10.6% and 0.47% ± 0.5%, respectively. These results suggest that the amoebicidal effect of apo-bLF without encystment might lead to the prevention of contamination of Acanthamoeba in SCL stock cases.

Lipid-rich bovine serum albumin improves the viability and hatching ability of porcine blastocysts produced in vitro.

The effects of lipid-rich bovine serum albumin (LR-BSA) on the development of porcine blastocysts produced in vitro were examined. Addition of 0.5 to 5 mg/ml LR-BSA to porcine blastocyst medium (PBM) from Day 5 (Day 0 = in vitro fertilization) significantly increased the hatching rates of blastocysts on Day 7 and the total cell numbers in Day-7 blastocysts. When Day-5 blastocysts were cultured with PBM alone, PBM containing LR-BSA, recombinant human serum albumin or fatty acid-free BSA, addition of LR-BSA significantly enhanced hatching rates and the cell number in blastocysts that survived compared with other treatments. The diameter, ATP content and numbers of both inner cell mass and total cells in Day-6 and Day-7 blastocysts cultured with PBM containing LR-BSA were significantly higher than in blastocysts cultured with PBM alone, whereas LR-BSA had no effect on mitochondrial membrane potential. The mRNA levels of enzymes involved in fatty acid metabolism and ß-oxidation (ACSL1, ACSL3, CPT1, CPT2 and KAT) in Day-7 blastocysts were significantly upregulated by the addition of LR-BSA. The results indicated that LR-BSA enhanced hatching ability and quality of porcine blastocysts produced in vitro, as determined by ATP content, blastocyst diameter and expression levels of the specific genes, suggesting that the stimulatory effects of LR-BSA arise from lipids bound to albumin.

Centrifugation on Percoll density gradient enhances motility, membrane integrity and in vitro fertilizing ability of frozen-thawed boar sperm.

The effects of Percoll density gradient centrifugation on sperm quality, in vitro fertilizability and developmental capacity of frozen-thawed boar sperm were evaluated. Two-step density gradient centrifugation by Percoll enhanced significantly the motility parameters of sperm compared with a simple centrifugation procedure. Percentages of motile sperm and sperm with intact plasma and acrosome membranes after Percoll separation were significantly greater than those after simple centrifugation. The rates of penetration, cleavage and blastocyst formation after in vitro fertilization were significantly improved by Percoll separation compared with simple centrifugation and were influenced positively by the intactness of sperm head membranes, but not any sperm motility parameters. However, insemination with increased concentrations of sperm prepared by Percoll gradient centrifugation did not improve the success of fertilization and embryo development in vitro. Our results indicate that the integrity of sperm head membranes after Percoll separation is important for successful embryo development in vitro, more so than sperm motility.

Inhibition of radical reactions for an improved potassium tert-butoxide-promoted (11) C-methylation strategy for the synthesis of α-(11) C-methyl amino acids.

α-(11) C-Methyl amino acids are useful tools for biological imaging studies. However, a robust procedure for the labeling of amino acids has not yet been established. In this study, the (11) C-methylation of Schiff-base-activated α-amino acid derivatives has been optimized for the radiosynthesis of various α-(11) C-methyl amino acids. The benzophenone imine analog of methyl 2-amino butyrate was (11) C-methylated with [(11) C]methyl iodide following its initial deprotonation with potassium tert-butoxide (KOtBu). The use of an alternative base such as tetrabutylammonium fluoride, triethylamine, and 1,8-diazabicyclo[5.4.0]undec-7-ene did not result in the (11) C-methylated product. Furthermore, the KOtBu-promoted (11) C-methylation of the Schiff-base-activated amino acid analog was enhanced by the addition of 1,2,4,5-tetramethoxybenzene or 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO) and inhibited by the addition of 1,10-phenanthroline. These results suggest that inhibition of radical generation induced by KOtBu improves the α-(11) C-methylation of the Schiff-base-activated amino acids. The addition of a mixture of KOtBu and TEMPO to a solution of Schiff-base-activated amino acid ester and [(11) C]methyl iodide provided optimal results, and the tert-butyl ester and benzophenone imine groups could be readily hydrolyzed to give the desired α-(11) C-methyl amino acids with a high radiochemical conversion. This strategy could be readily applied to the synthesis of other α-(11) C-methyl amino acids.

Development of radioiodine-labeled mequitazine for evaluation of hepatic CYP2D activity.

Background: As drug-metabolizing enzyme activities are affected by a variety of factors, such as drug-drug interactions, a method to evaluate drug-metabolizing enzyme activities in real time is needed. In this study, we developed a novel SPECT imaging probe for evaluation of hepatic CYP2D activity. Methods: Iodine-123- and 125-labeled 4-iodobenzylmequitazine (123/125I-BMQ) was synthesized with high labeling and purity. CYP isozymes involved in the metabolism of 125I-BMQ in mouse liver microsomes were evaluated, and the utility of 123/125I-was assessed from biological distribution and SPECT imaging evaluation in normal and CYP2D-inhibited mice. Results: In vitro metabolite analysis using mouse liver microsomes showed that 125I-BMQ is specifically metabolized by CYP2D. Biological distribution and SPECT imaging of 123/125I-BMQ in normal mice showed that injection 123/125I-BMQ accumulated early in the liver and was excreted into the gallbladder and intestines. In CYP2D-inhibited mice, accumulation in the liver was increased, but accumulation in the gallbladder and intestines, the excretory organ, was delayed. Since only metabolites of 125I-BMQ are detected in bile, visualization and measuring of the accumulation of metabolites over time in the intestine, where bile is excreted, could predict the amount of metabolites produced in the body and evaluate CYP2D activity, which would be useful in determining the dosage of various drugs metabolized by CYP2D. Conclusion: 123/125I-BMQ is useful as a SPECT imaging probe for comprehensive and direct assessment of hepatic CYP2D activity in a minimally invasive and simple approach.

Neural substrates of cough control during coughing.

Cough is known as a protective reflex to keep the airway free from harmful substances. Although brain activity during cough was previously examined mainly by functional magnetic resonance imaging (fMRI) with model analysis, this method does not capture real brain activity during cough. To obtain accurate measurements of brain activity during cough, we conducted whole-brain scans during different coughing tasks while correcting for head motion using a restraint-free positron emission tomography (PET) system. Twenty-four healthy right-handed males underwent multiple PET scans with [15O]H2O. Four tasks were performed during scans: "resting"; "voluntary cough (VC)", which simply repeated spontaneous coughing; "induced cough (IC)", where participants coughed in response to an acid stimulus in the cough-inducing method with tartaric acid (CiTA); and "suppressed cough (SC)", where coughing was suppressed against CiTA. The whole brain analyses of motion-corrected data revealed that VC chiefly activated the cerebellum extending to pons. In contrast, CiTA-related tasks (IC and SC) activated the higher sensory regions of the cerebral cortex and associated brain regions. The present results suggest that brain activity during simple cough is controlled chiefly by infratentorial areas, whereas manipulating cough predominantly requires the higher sensory brain regions to allow top-down control of information from the periphery.

Synthesis and in vitro cellular uptake of 11C-labeled 5-aminolevulinic acid derivative to estimate the induced cellular accumulation of protoporphyrin IX.

Protoporphyrin IX (PpIX) accumulation induced by exogenous 5-aminolevulinic acid (ALA) in tumors affects the therapeutic efficacy of ALA-based photodynamic and sonodynamic therapies. To develop a new imaging probe to estimate the ALA-induced PpIX accumulation, (11)C-labeled ALA analog (4), an ALA-dehydratase inhibitor, was radiosynthesized via (11)C-methylation of a Schiff-base-activated precursor in the presence of tetrabutylammonium fluoride, followed by the hydrolysis of ester and imine groups. The cellular uptake of 4 linearly increased with time and was inhibited by ALA and other transporter competitors. Monitoring analog 4 with positron emission tomography might be useful to estimate the ALA-induced PpIX accumulation in tumors.

Effective nose-to-brain drug delivery using a combination system targeting the olfactory region in monkeys.

The nose-to-brain (N2B) pathway has garnered attention because it transports drugs directly into the brain. Although recent studies have suggested the necessity of selective drug administration to the olfactory region for effective N2B drug delivery, the importance of delivering the formulation to the olfactory region and the detailed pathway involved in drug uptake in primates brain remain unclear. Here, we developed a combination system for N2B drug delivery comprising a proprietary mucoadhesive powder formulation and a dedicated nasal device (N2B-system) and evaluated it for nasal drug delivery to the brain in cynomolgus monkeys. This N2B-system demonstrated a much greater formulation distribution ratio in the olfactory region in an in vitro experiment using a 3D-printed nasal cast and in vivo experiment using cynomolgus monkeys, as compared to that in other nasal drug delivery systems that comprise of a proprietary nasal powder device developed for nasal absorption and vaccination and a commercially available liquid spray. Additionally, Texas Red-labeled dextran (TR-DEX, 3 kDa) was administered using the N2B-system to estimate the drug transition pathway from the nasal cavity to the brain. TR-DEX preferentially localized to the olfactory epithelium and reached the olfactory bulb through the cribriform foramina. Moreover, domperidone, a model drug with poor blood-brain barrier permeability, was administered to assess the brain uptake of medicine after olfactory region-selective administration by using the N2B-system. Domperidone accumulation in the brain was evaluated using positron emission tomography with intravenously administered [18F]fallypride based on competitive inhibition of the dopamine D2 receptor (D2R). Compared to other systems, the N2B-system significantly increased D2R occupancy and domperidone uptake in the D2R-expressing brain regions. The current study reveals that the olfactory region of the nasal cavity is a suitable target for efficient nasal drug delivery to the brain in cynomolgus monkeys. Thus, the N2B-system, which targets the olfactory region, provides an efficient approach for developing effective technology for nasal drug delivery to the brain in humans.

In vivo imaging of acute physiological responses after treatment of cancer with near-infrared photoimmunotherapy.

PURPOSE: Near-infrared photoimmunotherapy (NIR-PIT) is a new cancer phototherapy using an antibody-photosensitizer conjugate (Ab-IR700). By NIR light irradiation, Ab-IR700 forms a water-insoluble aggregation on the plasma membrane of cancer cells, leading to lethal membrane damage of cancer cells with high selectivity. However, IR700 produces singlet oxygen, which induces non-selective inflammatory responses such as edema in normal tissues around the tumor. Understanding such treatment-emergent responses is important to minimize side effects and improve clinical outcomes. Thus, in this study, we evaluated physiological responses during NIR-PIT by magnetic resonance imaging (MRI) and positron emission tomography (PET). PROCEDURES: Ab-IR700 was intravenously injected into tumor-bearing mice with two tumors on the right and left sides of the dorsum. At 24 h after injection, a tumor was irradiated with NIR light. Edema formation was examined by T1/T2/diffusion-weighted MRI and inflammation was investigated by PET with 2-deoxy-2-[18F]fluoro-D-glucose ([18F]FDG). Because inflammation can increase vascular permeability via inflammatory mediators, we evaluated changes in oxygen levels in tumors using a hypoxia imaging probe, [18F]fluoromisonidazole ([18F]FMISO). RESULTS: The uptake of [18F]FDG in the irradiated tumor was significantly decreased compared to the control tumor, indicating the impairment of glucose metabolism induced by NIR-PIT. MRI and [18F]FDG-PET images showed that inflammatory edema with [18F]FDG accumulation was present in the surrounding normal tissues of the irradiated tumor. Furthermore, [18F]FMISO accumulation in the center of the irradiated tumor was relatively low, indicating the enhancement of oxygen supply due to increased vascular permeability. In contrast, high [18F]FMISO accumulation was observed in the peripheral region, indicating enhancement of hypoxia in the region. This could be because inflammatory edema was formed in the surrounding normal tissues, which blocked blood flow to the tumor. CONCLUSIONS: We successfully monitored inflammatory edema and changes in oxygen levels during NIR-PIT. Our findings on the acute physiological responses after light irradiation will help to develop effective measures to minimize the side effects in NIR-PIT.

Glucose and glycine synergistically enhance the in vitro development of porcine blastocysts in a chemically defined medium.

In the present study, the effects of glucose and/or glycine on the in vitro development of Day 5 (Day 0=IVF) porcine blastocysts were determined. The addition of 2.5-10 mM glucose to the chemically defined culture medium porcine zygote medium (PZM)-5 significantly increased blastocyst survival rates compared with those of blastocysts cultured in the absence of glucose. The addition of 5 and 10 mM glycine to PZM-5 containing 5 mM glucose significantly enhanced the development to hatching and the number of hatched blastocysts compared with no addition of glycine. However, the addition of glycine to PZM-5 with no glucose did not improve blastocyst development. The ATP content of Day 6 blastocysts cultured with glucose was significantly higher than that of blastocysts cultured in the absence of glucose, regardless of glycine supplementation. The diameter and total cell numbers were significantly greater, and the apoptotic index was significantly lower, in Day 6 blastocysts cultured with both glucose and glycine. These results indicate that glucose is an important energy source for the porcine blastocyst and that glucose and glycine act synergistically to enhance development to the hatching and hatched blastocyst stage in vitro.

Indirect SPECT Imaging Evaluation for Possible Nose-to-Brain Drug Delivery Using a Compound with Poor Blood-Brain Barrier Permeability in Mice.

Single-photon emission computed tomography (SPECT) imaging using intravenous radioactive ligand administration to indirectly evaluate the time-dependent effect of intranasal drugs with poor blood-brain barrier permeability on brain drug distributions in mice was evaluated. The biodistribution was examined using domperidone, a dopamine D2 receptor ligand, as the model drug, with intranasal administration at 0, 15, or 30 min before intravenous [123I]IBZM administration. In the striatum, [123I]IBZM accumulation was significantly lower after intranasal (IN) domperidone administration than in controls 15 min after intravenous [125I]IBZM administration. [123I]IBZM SPECT was acquired with intravenous (IV) or IN domperidone administration 15 min before [123I]IBZM, and time-activity curves were obtained. In the striatum, [123I]IBZM accumulation was clearly lower in the IN group than in the control and IV groups. Time-activity curves showed no significant difference between the control and IV groups in the striatum, and values were significantly lowest during the first 10 min in the IN group. In the IN group, binding potential and % of receptor occupancy were significantly lower and higher, respectively, compared to the control and IV groups. Thus, brain-migrated domperidone inhibited D2R binding of [123I]IBZM. SPECT imaging is suitable for research to indirectly explore nose-to-brain drug delivery and locus-specific biological distribution.