Effects of Gait Treatment With a Single-Leg Hybrid Assistive Limb System After Acute Stroke: A Non-randomized Clinical Trial

We hypothesized that a single-leg version of the Hybrid Assistive Limb (HAL) system could improve the gait and physical function of patients with hemiparesis following a stroke. In this pilot study, we therefore compared the efficacy of HAL-based gait training with that of conventional gait training (CGT) in patients with acute stroke. Patients admitted to the participating university hospital were assigned to the HAL group, whereas those admitted to outside teaching hospitals under the same rehabilitation program who did not use the HAL were assigned to the control group. Over 3 weeks, all participants completed nine 20 min sessions of gait training, using either HAL (i.e., the single-leg version of HAL on the paretic side) or conventional methods (i.e., walking aids and gait orthoses). Outcome measures were evaluated before and after the nine training sessions. The Functional Ambulation Category (FAC) was the primary outcome measure, but the following secondary outcome measures were also assessed: National Institutes of Health Stroke Scale, Fugl-Meyer Assessment (Lower Extremity), comfortable walking speed, step length, cadence, 6-min walk distance, Barthel Index, and Functional Independence Measure. In total, 22 post-stroke participants completed the clinical trial: 12 in the HAL group and 10 in the CGT group. No serious adverse events occurred in either group. The HAL group showed significant improvement in FAC after nine sessions when compared with the CGT group (P = 0.014). However, secondary outcomes did not differ significantly between the groups. Our results demonstrate that HAL-based gait therapy may improve independent walking in patients with acute stroke hemiplegia who are dependent on ambulatory assistance. A larger-scale randomized controlled trial is needed to clarify the effectiveness of single-leg HAL therapy. Clinical Trial Registration: UMIN Clinical Trials Registry, identifier UMIN000022410.

Regular medications prescribed to elderly neurosurgical inpatients and the impact of hospitalization on potentially inappropriate medications

Objective: This study aimed to evaluate the regular medications prescribed to elderly neurosurgical inpatients in community hospitals in Japan.

Materials and Methods: Elderly patients (aged ≥ 65 years) who had been admitted to neurosurgery departments from April 2015 to March 2017 were enrolled in this study. We collected data on regular medications at the time of admission and discharge. Furthermore, we retrospectively analyzed factors associated with potentially inappropriate medications (PIMs). PIMs were defined as polypharmacy (≥ 6 medications used concurrently) or taking any of the unfavorable medications on the “list of drugs to be prescribed with special caution” in the “Guidelines for Medical Treatment and Its Safety in the Elderly 2015”.

Results: We gathered data on over 1900 medications (mean number, 5.04) prescribed to 197 patients (mean age, 76.9 years). PIMs were observed in 51.3% of patients on admission. The most common prescriptions resulting in PIMs were benzodiazepine agents, followed by loop diuretics and H2 receptor antagonists. The multivariate analysis revealed that age (odds ratio, 1.08; p < 0.01) and the number of prescribers (odds ratio, 6.16; p < 0.01) were significantly related to PIMs on admission. PIM exposure at the time of discharge accounted for 39.1%, a 12.2% decrease.

Conclusion: More than half of the elderly patients were prescribed PIMs on admission; however, this exposure decreased by 12.2% at the time of discharge. Hospitalization is an optimal opportunity for reconsidering the necessity of medications and for changing the prescriptions according to patients’ conditions.

Paraplegia caused by cerebral contusions in the bilateral precentral gyri

Background:

Paraplegia is mainly caused by spinal cord disease and rarely occurs due to head trauma. In this report, we describe a case of paraplegia caused by cerebral contusions in the bilateral precentral gyri.

Case Description:

A 72-year-old man was admitted to our hospital with mildly impaired consciousness and severe pure motor paralysis in both legs. He was healthy until the morning of the day, but his wife found him injured in front of his house upon returning home. He had a subcutaneous hematoma in his occipital region, and seemed to have slipped by accident. Computed tomography of the brain and magnetic resonance imaging (MRI) of his spinal cord revealed no apparent cause of the paraplegia, although an MRI of his brain clearly revealed cerebral contusions in the bilateral precentral gyri. The cerebral contusion was diagnosed as the cause of pure motor paralysis of lower extremities. He received rehabilitation, and manual muscle testing of his legs revealed improvements. In the subacute phase, the precentral gyrus lesion disappeared on MRI.

Conclusion:

We must emphasize that cerebral contusion can be a differential diagnosis for paraplegia. In the acute phase, fluid-attenuated inversion recovery (FLAIR) MRI coronal and sagittal images are useful for identifying precentral gyri contusions. Paraplegia caused by a cerebral contusion may be misdiagnosed as a spinal concussion due to the disappearance of the precentral gyrus lesion on FLAIR MRI in the subacute phase.

Low-temperature heat capacities of confined liquid benzene, implying the behavior of ordinary bulk liquids

Isobaric heat capacities C p of benzene confined in silica MCM-41 mesopores with average diameters equal to and smaller than 2.9 nm were measured by precise adiabatic calorimetry. The confined benzene samples revealed no thermal anomaly due to crystallization/fusion and vitrified at low temperatures. The C p curves displayed a hump and a considerably quick decrease on the low-temperature side of the hump as the pore diameter increased. The enthalpy-relaxation effects observed on intermittent heating showed that the anomaly of the C p hump and quick decrease is not assigned to a glass transition. The bend in the temperature dependence of density reported previously was interpreted as corresponding to the quick decrease in C p . We concluded that the anomalous C p and density behaviors originated from the ordering/excitation in the configurational state, close to the ground state, of confined molecular aggregate and proposed a scenario that explains the general C p curves of ordinary bulk supercooled liquids in equilibrium at low temperatures below the glass-transition temperatures.

PARG dysfunction enhances DNA double strand break formation in S-phase after alkylation DNA damage and augments different cell death pathways

Poly(ADP-ribose) glycohydrolase (PARG) is the primary enzyme responsible for the degradation of poly(ADP-ribose). PARG dysfunction sensitizes cells to alkylating agents and induces cell death; however, the details of this effect have not been fully elucidated. Here, we investigated the mechanism by which PARG deficiency leads to cell death in different cell types using methylmethanesulfonate (MMS), an alkylating agent, and Parg^−/− mouse ES cells and human cancer cell lines. Parg^−/− mouse ES cells showed increased levels of γ-H2AX, a marker of DNA double strand breaks (DSBs), accumulation of poly(ADP-ribose), p53 network activation, and S-phase arrest. Early apoptosis was enhanced in Parg^−/− mouse ES cells. Parg^−/− ES cells predominantly underwent caspase-dependent apoptosis. PARG was then knocked down in a p53-defective cell line, MIAPaCa2 cells, a human pancreatic cancer cell line. MIAPaCa2 cells were sensitized to MMS by PARG knockdown. Enhanced necrotic cell death was induced in MIAPaCa2 cells after augmenting γ-H2AX levels and S-phase arrest. Taken together, these data suggest that DSB repair defect causing S-phase arrest, but p53 status was not important for sensitization to alkylation DNA damage by PARG dysfunction, whereas the cell death pathway is dependent on the cell type. This study demonstrates that functional inhibition of PARG may be useful for sensitizing at least particular cancer cells to alkylating agents.

Evolution of Nanoscale Ferromagnetic Particles in Co-Cr and Cr-Fe Alloys Observed by Atom Probe Field Ion Microscopy

With appropriate processing conditions, nanoscale ferromagnetic particles precipitate from nonmagnetic matrix phase in the Co-Cr and Cr-Fe systems. In these heterogeneous alloys, unique magnetic properties are observed. In order to correlate such magnetic properties with the microstructures, we have employed an atom probe field ion microscope (APFIM) and a three dimensional atom probe (3DAP). In the Co-22Cr thin film sputter-deposited at elevated temperatures (~500 K), both APFIM and 3DAP data convincingly showed that the film was composed of lamellae-like ferromagnetic and paramagnetic phases of approximately 8 nm in thickness. On the other hand, it was shown that the films sputter-deposited at ambient temperature was composed of s-Co single phase without significant compositional heterogeneity. Based on these observations, we conclude that phase separation progresses during the growth of the film on a heated substrate. In the Cr-Fe alloy, large negative MR was observed in the as-quenched alloy at liquid helium temperature. However, the MR behavior changes as the phase decomposition progresses by annealing. The change in the MR behavior observed in this alloy with various heat treatment conditions will be discussed based on the microstructural characterization results by APFIM and 3DAP.

Control of drug loading efficiency and drug release behavior in preparation of hydrophilic-drug-containing monodisperse PLGA microspheres

We prepared monodisperse poly(lactide-co-glycolide) (PLGA) microspheres containing blue dextran (BLD)--a hydrophilic drug--by membrane emulsification technique. The effects of electrolyte addition to the w(2) phase and significance of the droplet size ratio between primary (w(1)/o) and secondary (w(1)/o/w(2)) emulsions during the preparation of these microspheres was examined. The droplet size ratio was evaluated from the effect of stirring rate of the homogenizer when preparing the primary emulsion. The drug loading efficiency of BLD in these microspheres increased with stirring rate. It increased to approximately 90% when 2.0% NaCl was added to the w(2) phase. Drug release from these microspheres was slower than that when they were prepared without electrolyte addition. Despite the very high efficiency drug release was gradual because BLD was distributed at the microspheres core. Relatively monodisperse hydrophilic-drug-containing PLGA microspheres with controlled drug loading efficiency and drug release behavior were prepared.

[Video-assisted thoracic surgery for clinical stage I lung cancer]

We evaluated our results of video-assisted thoracic surgery (VATS) performed for lung cancer over 8 years. Between April 2000 and October 2008, a total of 409 (60.9%) underwent VATS for lung cancer. Operative procedures as a radical operation were partial resection in 58 patients, segmentectomy in 64 patients, and lobectomy in 229 patients. There was 1 patient with operative death including hospital death due to pulmonary thromboembolism. In a median follow-up period of 21 months, the 5-year cause specific survival rate was 93.7%. According to operative procedures, the 5-year survival rate was 100% in patients underwent partial resection and segmentectomy, and 91.1% in patients underwent lobectomy. According to pathological stages, the 5-year survival rate was 98.8% in 289 patients with stage IA, 69.1% in 34 patients with stage IB, and 68.2% in 14 patients with stage IIIA. In conclusion, VATS lobectomy and VATS intentional limited resection can be performed with low mortality and good prognosis for clinical stage IA lung cancer patients.

Hepatic changes in adenine nucleotide levels and adenosine 3'-monophosphate forming enzyme in streptozotocin-induced diabetic mice

To elucidate the pathophysiological significance of adenosine 3'-monophosphate (3'-AMP) forming enzyme in mice, the effect of streptozotocin (STZ) on the enzyme activities and adenine nucleotide levels in the ICR mice (4-week-old) liver was examined. After 2 weeks, treatment with a single dosage of STZ (100, 150 or 200 mg/kg i.p.) induced a dose-dependent hyperglycemia and hypoinsulinemia but had no effect on serum alanine aminotransferase activity, indicating that STZ generated type 1 diabetes without hepatitis. In the diabetic liver, the activities of superoxide dismutase (SOD), catalase and ATP levels decreased, and the microsomal CYP2E1 activity increased. Changes of these biological activities might disrupt the cellular homeostatic balance of reactive oxygen species (ROS) production. The activities of 3'-AMP forming enzyme, one of the ribonucleases, in hepatic homogenates were not altered. However, in the STZ 200 mg/kg group, the cytosolic forming enzyme activities were enhanced, and inversely, the mitochondrial activity was reduced significantly, indicating that the decrease in the mitochondrial activity may be accelerated by development of diabetes due to the decrease in the antioxidant defense system and/or increase in ROS production. With the decrease in the 3'-AMP forming enzyme activity, the levels of 3'-AMP, a P-site inhibitor of adenylate cyclase, in mitochondrial were significantly reduced. These results obtained suggested that change in the mitochondrial 3'-AMP forming enzyme activity might reflect the pathophysiological change of mitochondrial function with the development of diabetes. Our results also suggested that change in cytosolic enzyme activity might serve as a new biomarker of oxidative stress because significant negative correlation between the activities of cytosolic 3'-AMP forming enzyme and SOD was found in the early stage of diabetes.

Factors affecting the loading efficiency of water-soluble drugs in PLGA microspheres

Poly(lactide-co-glycolide), PLGA, microspheres containing blue dextran as a hydrophilic model drug were prepared by a solvent evaporation method from w/o/w emulsions using a micro homogenizer. Effects of surfactant concentration in oil phase, stirring time period and stirring rate in the preparation procedure of primary emulsion (w/o) upon drug-loading efficiency were evaluated. Stirring rate during preparation of primary emulsion and surfactant concentration in oil phase affected drug-loading efficiency and the particle size of primary emulsion. Microspheres having the higher drug-loading efficiency were obtained when size differences between the primary emulsions and the secondary ones were large. That is, when the diameter of the primary emulsion is much smaller than that of the secondary emulsion, PLGA microspheres with high-loading efficiency of blue dextran were obtained.

Incorporation of water-soluble drugs in PLGA microspheres

Poly(lactide-co-glycolide) (PLGA) microspheres containing blue dextran, as a model of water-soluble drugs, were prepared from w(1)/o/w(2) emulsions by using a microhomogenizer and a solvent evaporation method. Effects of preparation conditions, such as, concentration of poly(vinyl alcohol) (PVA) in w(2) phase, viscosity of inner soluble water phase, volume ratio of oil phase to w(1) phase in primary emulsion, PLGA concentration in oil phase, and molecular weight or composition of PLGA, upon the properties of PLGA microspheres containing water-soluble drugs were examined. Concentration of poly(vinyl alcohol) (PVA), the dispersant dissolved in w(2) phase of secondary emulsion did not show any effects on the final particle size. On the other hand, volume ratio of oil phase to water one in primary emulsion affected the final particle size, which seemed to be related to the local PLGA concentration in w(1)/o emulsions. That is, the particle size increased as the volume ratio of w(1) phase against oil phase, w(1)/o (v/v), increased. The loading efficiency, however, was not affected by the volume ratio of w(1)/o (v/v), but affected by blue dextran concentration in w(1) phase. Higher loading efficiency was observed in PLGA microspheres prepared from w(1) phase containing lower concentration of blue dextran. Blue dextran solution (inner water phase) with the lower viscosity may result in the lower leakage ratio of blue dextran during the preparation procedure. Increases in concentration and molecular weight of PLGA made particle size larger.

Enhancement of cellular adenosine triphosphate levels in PC12 cells by 2,5-dideoxyadenosine, a P-site inhibitor of adenylate cyclase

To elucidate the biological significance of the P-site inhibitor of adenylate cyclase, the effect of 2,5-dideoxyadenosine (DDA) on cellular levels of adenine compounds in PC12 cells was studied. The addition of DDA and deoxyadenosine (deoxyAdo), P-site inhibitors of adenylate cyclase, as well as the addition of adenosine (Ado) to the incubation medium containing glucose as the sole nutrient significantly enhanced cellular ATP levels in PC12 cells. N6-Methyladenosine and N6-cyclohexyladenosine did not augment the ATP levels. The ATP level-enhancing effect of DDA was further enhanced by Ado. After pretreatment of PC12 cells with theophylline, DDA-induced ATP enhancement was potentiated by theophylline but the effect of Ado was suppressed. cAMP levels in PC12 cells were markedly reduced by DDA but the levels were not changed by Ado. These results suggest for the first time that P-site inhibitors of adenylate cyclase may stimulate ATP synthesis via glycolysis by decreasing cAMP levels and the mode of action of the ATP level-enhancing effect of DDA may be different from that of Ado.

Effect of specific antigen stimulation on intraepithelial lymphocyte migration to small intestinal mucosa

Migration of intraepithelial lymphocytes (IELs) into intestinal epithelium is not yet well understood. We established an IEL-cell line from ovalbumin (OVA) 23-3 transgenic (Tg) mice and investigated the effect of antigen stimulation on the dynamic process of IEL migration into small intestinal mucosa. The cell line was a T cell receptor (TCR) alphabeta(+) CD4(+) CD8(-) phenotype, expressing alphaEbeta7 integrin in 90% of cells. Under intravital microscopy, the lined IELs adhered selectively to the microvessels of the intestinal villus tip of the Tg mice. The accumulation of IELs was significantly inhibited by an antibody against beta7-integrin and MAdCAM-1. When IELs were stimulated with OVA, the accumulation was attenuated compared to that of resting cells, with decreased expression of alphaEbeta7 integrin. In Tg mice fed with OVA, the number of IELs which migrated in the villus mucosa was significantly smaller than in the non-fed controls. The preferential migratory capacity of IELs to villus mucosa may be altered by specific antigen stimulations.

Effect of iron lactate overloading on adenine nucleotide levels and adenosine 3'-monophosphate forming enzyme in rat liver and spleen

To elucidate the pathophysiological significance of adenosine 3'-monophosphate (3'-AMP) forming enzyme in rats, the effect of iron lactate overloading on the enzyme activities and adenine nucleotide levels in the liver and spleen was examined. Sprague-Dawley rats were fed a diet supplemented with 0%, 0.625% or 5.0% of iron lactate for 4 weeks. Iron deposition was found in periportal hepatocytes, Kupffer cells and macrophages of red pulp of the spleen. No significant changes in hematological parameters were detected. Although serum alkaline phosphatase and inorganic phosphorus levels elevated slightly in the 5.0% group, activities of alanine aminotransferase and aspartate aminotransferase, and levels of serum urea nitrogen and creatinine were not changed significantly. The ATP levels in the liver and spleen of iron fed groups were significantly decreased, but adenosine 5'-diphosphate (ADP) and adenosine 5'-monophosphate (AMP) levels were within control levels. On the other hand, the levels of ATP, ADP and AMP in the erythrocytes without mitochondria were not suppressed by the iron lactate overloading. Free activity of 3'-AMP forming enzyme, one of ribonucleases (RNase), was not changed in the liver of iron-overloaded rat, and total amount of 3'-AMP and adenosine formed after the treatment of the crude enzyme(s) with p-chloromercuribenzensulfonic acid, a SH blocker of RNase inhibitors, was decreased dose-dependently. On the contrary, free activity of 3'-AMP forming enzyme was enhanced dose-dependently in the spleen of iron-overloaded rat but the total activity was not changed. However, the free and total 3'-AMP forming enzyme activities in the liver and spleen of iron-overloaded rats became equal at the dosage of 5.0% of iron lactate. The results obtained suggested that iron loading might induce significant decrease in hepatic and splenic ATP levels via malfunction of their mitochondria and might lead dissociation of RNase-RNase inhibitor complex to activate 3'-AMP forming enzyme in both tissues.

Micro-emulsion synthesis of monodisperse surface stabilized silicon nanocrystals

Silicon nanocrystals with a uniform size distribution were synthesized in inverse micelles using powerful hydride reducing agents. The silicon nanocrystals surfaces were then stabilized with 1-heptene to produce particles with strong blue photoluminescence.

Enhancement of cellular adenosine triphosphate levels in PC12 cells by extracellular adenosine

To elucidate the biological significance of extracellular adenine compounds, the effects of adenosine (Ado) on cellular levels of adenine compounds, especially adenosine triphosphate (ATP), in PC12 cells were studied. Ado and inosine but not adenosine 5'-monophosphate, adenosine 5'-diphosphate, ATP, guanosine, cytosine, thymidine, and uridine, significantly enhanced cellular ATP levels in PC12 cells in time- and dose-dependent manners. Various P1 receptor agonists of Ado did not enhance the ATP level. In addition, theophylline, an antagonist of P1 receptors, did not inhibit the Ado-evoked ATP enhancement. These results suggest that the Ado receptor is not involved in the augmentation of the cellular ATP level induced by Ado in PC12 cells. The ATP-enhancing effect of Ado was potentiated by dipyridamole, an inhibitor of Ado uptake, or coformycin, an inhibitor of Ado deaminase. The effect of Ado on the ATP level was also observed when PC12 cells were incubated in glucose-free medium. Together these results suggest that enhancement of cellular ATP levels in PC12 cells by extracellular Ado might be acceleration of ATP synthesis through the Ado salvage system using hypoxanthine-guanine phosphoribosyltransferase rather than Ado kinase since 5'-iodotubercidin, an inhibitor of Ado kinase, had no effect on the enhancement elicited by Ado.

Intercellular cell adhesion molecule-1 regulates lymphocyte movement into intestinal microlymphatics of rat Peyer's patches

The objective of this study was to determine whether specific adhesion molecules modulate lymphocyte movement from Peyer's patches into intestinal microlymphatics. The fluorochrome acridine orange was injected via a micropipette into Peyer's patches to fill lymphatics. The flux of labeled lymphocytes into intestinal microlymphatics was monitored with intravital fluorescence microscopy. The lymphatic microvessels in the perifollicular area of Peyer's patches were filled with lymphocytes, most of which remained within the lymphatics. Some lymphocytes became detached and were drained into intestinal lymph. Administration of antibodies directed against ICAM-1 significantly increased lymphocyte flux into interfollicular lymphatics. The immunohistochemical study showed intense ICAM-1 expression on the lymphocytes densely packed in the lymphatics surrounding follicles in Peyer's patches. A large number of lymphocytes are normally sequestered in the lymphatic network of Peyer's patches. This sequestration of lymphocytes is largely mediated by ICAM-1-dependent cell-cell interactions.

In situ demonstration of intraepithelial lymphocyte adhesion to villus microvessels of the small intestine

The recirculation of lymphocytes through the intestinal mucosa is important for specific immune defense, but the origin and differentiation of intraepithelial lymphocytes (IEL) are not fully understood. The present study therefore used intravital microscopy to investigate the migration of IEL to the villus mucosa and Peyer's patches of the small intestine. IEL were separated from inverted murine small intestine and mesenteric lymph node (MLN) T cells were also isolated. The adhesion of fluorescence-labeled lymphocytes to postcapillary venules (PCV) of Peyer's patches and arcade microvessels of small intestinal villi was observed after injection. In some experiments, the effect of antibodies against adhesion molecules on cell kinetics were investigated. IEL time-dependently accumulated in villus microvessels of the small intestine, whereas few MLN cells did. Few IEL adhered to the PCV of Peyer's patches. IEL were shown to express alpha(E)beta(7)-integrin but not L-selectin. The accumulation of IEL in villus archade was significantly inhibited by antibody against beta(7)-integrin or mucosal addressin cell adhesion molecules (MAdCAM)-1, but not by alpha(E)-integrin. The combined blocking of beta(7)-integrin and MAdCAM-1 further attenuated the sticking of IEL in this area, although it did not entirely block the IEL adherence. The adherence of CD4(+) or TCRalphabeta IEL to villus microvessels was significantly greater than that of CD4(-) or TCRgammadelta IEL. It was demonstrated in situ for the first time that IEL adhered selectively to the villus microvessels of the small intestine partly via beta(7) and MAdCAM-1.

Intravital demonstration of modulation of T lymphocyte migration by CINC/gro in rat Peyer's patches

BACKGROUND/AIMS

Cytokine-induced neutrophil chemoattractant (CINC/gro), a member of interleukin-8 family, was found as a potent chemotactic factor for rat neutrophils. Although several chemokines have been shown to be potent regulators of T cell chemotaxis in vitro, the potential role of chemokines in T-cell migration in gut-associated lymphoid tissues has not been investigated in vivo. In the present study, the effects of CINC/gro on T-lymphocyte migration were examined in rat Peyer's patches.

METHODS

T lymphocytes collected from intestinal lymph of rats were fluorescence-labeled and injected into the jugular vein. Peyer's patches of the recipient rats were observed with intravital fluorescence microscopy and the effects of CINC/gro infusion was investigated. Lymphocyte flux in mesenteric collecting lymphatics was also observed.

RESULTS

In vivo infusion of CINC/gro significantly attenuated the initial lymphocyte interaction with postcapillary venules of Peyer's patches. However, once these lymphocytes adhered to venules, CINC/gro treatment significantly accelerated the transendothelial migration of T lymphocytes and they also significantly increased their subsequent flux in collecting lymphatics.

CONCLUSION

There is a possibility that CINC/gro could modulate the characteristics of T lymphocyte homing in the inflammatory sites of gut.

The receptor for advanced glycation end products is induced by the glycation products themselves and tumor necrosis factor-alpha through nuclear factor-kappa B, and by 17beta-estradiol through Sp-1 in human vascular endothelial cells

The binding of advanced glycation end products (AGE) to the receptor for AGE (RAGE) is known to deteriorate various cell functions and is implicated in the pathogenesis of diabetic vascular complications. Here we show that AGE, tumor necrosis factor-alpha (TNF-alpha), and 17beta-estradiol (E(2)) up-regulated RAGE mRNA and protein levels in human microvascular endothelial cells and ECV304 cells, with the mRNA stability being essentially invariant. Transient transfection experiments with human RAGE promoter-luciferase chimeras revealed that the region from nucleotide number -751 to -629 and the region from -239 to -89 in the RAGE 5'-flanking sequence exhibited the AGE/TNF-alpha and E(2) responsiveness, respectively. Site-directed mutation of an nuclear factor-kappaB (NF-kappaB) site at -671 or of Sp-1 sites at -189 and -172 residing in those regions resulted in an abrogation of the AGE/TNF-alpha- or E(2)-mediated transcriptional activation. Electrophoretic mobility shift assays revealed that ECV304 cell nuclear extracts contained factors which retarded the NF-kappaB and Sp-1 elements, and that the DNA-protein complexes were supershifted by anti-p65/p50 NF-kappaB and anti-Sp-1/estrogen receptor alpha antibodies, respectively. These results suggest that AGE, TNF-alpha, and E(2) can activate the RAGE gene through NF-kappaB and Sp-1, causing enhanced AGE-RAGE interactions, which would lead to an exacerbation of diabetic microvasculopathy.

Brain water diffusion in normal and creatine-supplemented rats during transient global ischemia

Brain water diffusion in response to transient global ischemia (12 min), reperfusion (60 min), and cardiac arrest was monitored by localized proton magnetic resonance spectroscopy. The trace of the apparent diffusion coefficient tensor (ADC(Av)) was determined at high temporal resolution (10 sec) to assess the putative neuroprotective potential of oral creatine (Cr) in rats that received 2.2 g Cr-monohydrate per kg body weight per day for 10 days (n = 8) relative to controls (n = 9). Cr-fed rats revealed a statistically significant increase of the cerebral concentration ratio of Cr to choline-containing compounds (20%). The decrease of the ADC(Av) value during acute ischemia showed a three-phasic behavior in line with energy depletion, cytotoxic edema, and brain cooling. In Cr-fed rats, slightly less severe and mildly delayed diffusion changes during ischemia and similar beneficial trends during early reperfusion did not reach statistical significance. Magn Reson Med 42:798-802, 1999.

Altered migration of gut-derived T lymphocytes after activation with concanavalin A

Although activation of lymphocytes is known to be associated with profound changes in homing behavior, it remains unclear how activation alters migration of gut-derived lymphocytes in lymphoid and nonlymphoid organs. The objectives of this study were 1) to compare migration of naive and concanavalin A (ConA)-activated T lymphocytes into the gut mucosa, spleen, and liver and 2) to define the role of specific adhesion molecules in this homing process. Fluorescently labeled T lymphocytes collected from rat intestinal lymph were injected into the jugular vein, and the kinetics of appearance of the infused lymphocytes were monitored in ileal Peyer's patches, spleen, and liver. The migration of naive and ConA-activated T lymphocytes into microvessels were compared using an intravital microscope. ConA stimulation significantly increased the rolling velocity of T lymphocytes in postcapillary venules of Peyer's patches, and ConA-stimulated lymphocytes exhibited a loss of the selective adherence properties in Peyer's patches that is normally observed with naive T cells. ConA activation also suppressed the accumulation of T cells in the spleen. On the other hand, the adherence of T cells to hepatic sinusoidal endothelium was significantly increased after ConA activation, especially in the periportal area, and this increase was attenuated by an anti-intercellular adhesion molecule (ICAM)-1 antibody. Flow cytometry analysis revealed a decline in L-selectin expression and an increase in CD11a expression and ICAM-1 on the surface of ConA-treated T cells. In conclusion, activation of gut-derived T lymphocytes with ConA significantly alters their migration path, with a diminished localization to Peyer's patches and spleen and a preferential accumulation in hepatic sinusoids. This altered migration pattern likely results from changes in the expression of leukocyte adhesion molecules such as L-selectin and CD11a.

Proton MRS of oral creatine supplementation in rats. Cerebral metabolite concentrations and ischemic challenge

Proton magnetic resonance spectroscopy (MRS) was employed to determine the concentrations of N-acetylaspartate (NAA), total creatine (tCr), choline-containing compounds (Cho), myo-inositol (Ins), glucose (Glc), and lactate (Lac) in rat brain before and after 10 days of oral supplementation of 2.6 g Cr-monohydrate per kg body weight per day. Measurements were performed both in vitro (n = 16) and in vivo (n = 6). The neuroprotective potential of oral Cr was assessed by dynamically monitoring brain Glc and Lac in response to transient global ischemia (12 min). In comparison to controls the in vitro concentrations of Cr (13.1 +/- 9.3%) and Ins (12.7 +/- 14. 0%) were significantly increased in Cr-fed rats. Under in vivo conditions, the data revealed trends for elevated tCr (4.7%) and Ins (10.6%) which were enhanced in the concentration ratios of tCr:Cho (10.2%) and Ins:Cho (17.8%). Together with an increased Glc level (27.3%), the observation of a statistically significant decrease of brain Lac (-38.5 +/- 19.3%) in Cr-fed rats may reflect a shift of the energy metabolism from non-oxidative toward oxidative glycolysis. One hour after global ischemia most of the metabolic differences between Cr-fed rats and controls were retained. The increased Glc level (44.4 +/- 33.3%) reached statistical significance, but the accumulation of Lac and its time course during ischemia and early reperfusion showed no differences between Cr-fed rats and controls.

Dumbbell-shaped trigeminal neurinoma in a child

We experienced a case of solitary trigeminal neurinoma in a 10-year-old boy without stigmata of neurofibromatosis. This boy presented with progressive cerebellar ataxia, right abducens palsy and right hemiparesis. Magnetic resonance images (MRI) demonstrated a tumour extending into both the middle and posterior fossas forming a dumbbell-shaped mass lesion with a size of 35 x 30 x 45 mm. The tumour was successfully removed free of complications by a two-stage operation composed of right subtemporal and suboccipital retromastoid approaches. It is extremely rare for a solitary neurinoma to occur at this site in a child without neurofibromatosis. Surgical approaches in this type of tumour are discussed with a review of the literature.

Advanced glycation endproducts accelerate calcification in microvascular pericytes

Vascular calcification in advanced atherosclerosis is frequently associated with diabetes, and is a predictor of future cardiovascular events. To investigate the molecular mechanisms of vascular calcification, we examined whether advanced glycation endproducts (AGE) formed at an accelerated rate under diabetes induce the osteoblastic differentiation of pericytes, a mesenchymal progenitor. First, von Kossa staining demonstrated that AGE significantly increased the number of calcified nodules in a bovine pericyte culture. AGE were also found to induce calcium accumulation in the pericyte monolayer in time- and dose-dependent manners. Second, quantitative reverse transcription-polymerase chain reaction revealed that AGE increased the pericyte levels of mRNAs coding for alkaline phosphatase and osteopontin, the representative markers for early and late osteoblastic differentiation, respectively. Alkaline phosphatase activity was actually enhanced by AGE. The results suggest that AGE have the ability to induce the osteoblatic differentiation of pericytes, which would contribute to the development of vascular calcification in diabetes.

Volumetric MRI measurements of the tree shrew hippocampus

Protocols suitable for repeated magnetic resonance imaging (MRI) studies of the tree shrew's brain were established. This included the development of (i) a technique for prolonged inhalation anesthesia by endotracheal intubation; (ii) a reproducible fixation of the animal's head in a stereotaxic frame and finally (iii) the set-up of the hardware (rf coil) and software (MRI sequences) of the MRI system. The endotracheal intubation as well as the repeated and prolonged anesthesia showed no complications. The in vivo measurements of the tree shrew's hippocampal formation revealed a high reproducibility. Right and left hippocampal volume was determined as 85.2 mm3 +/- 8% and 87.4 mm3 +/- 10%, respectively. The utility of MRI in delineating alterations in brain anatomy was demonstrated in three animals receiving cortisol via the drinking water (5 mg/animal/day). After a 4-week treatment, in two of the three tree shrews a reduction in hippocampal volume was observed. Thus, the MRI protocols used here allow for repeated and non-invasive measurements of changes in hippocampal anatomy within the same animal and to monitor the temporal dynamics of structural alterations within this brain structure.

Insulin stimulates the growth and tube formation of human microvascular endothelial cells through autocrine vascular endothelial growth factor

Insulin treatment is known epidemiologically as an independent risk factor for the progression of diabetic retinopathy. However, how insulin exacerbates the retinopathy is not yet fully understood. In this study, we investigate the effects of insulin on the growth and tube formation of microvascular endothelial cells (EC). When human skin microvascular EC were grown under various concentrations of insulin, DNA synthesis as well as tube formation of EC was found to be significantly stimulated. We obtained evidence that it is mainly vascular endothelial growth factor (VEGF) that mediates the angiogenic activity of insulin as follows. (1) Insulin upregulates the level of mRNA coding for secretory forms of VEGF, while the expression of the two VEGF receptor genes, kinase insert domain-containing receptor (kdr) and fms-like tyrosine kinase1 (flt1), was essentially unchanged by exposure to insulin. (2) A monoclonal antibody against human VEGF can completely neutralize both the proliferation and the tube formation of EC induced by insulin. The angiogenic effects of insulin were additive with those of hypoxia, a principal factor that causes angiogenesis. Further, insulin significantly stimulated plasminogen activator inhibitor-1 activity in EC. The results thus suggest that insulin not only elicits angiogenesis through the induction of autocrine VEGF but also is a predisposing factor for thrombogenesis, which may give rise to focal ischemia that could superdrive angiogenesis, thereby leading to the exacerbation of diabetic retinopathy.

Vascular endothelial growth factor acts as a pericyte mitogen under hypoxic conditions

Angiogenesis is the process by which new vascular networks are formed from preexisting capillaries. The small vessels are composed of two types of cells, namely endothelial cells (EC) and pericytes, with the former being encircled by the latter. We previously showed that hypoxia, the principal cause of angiogenesis, can induce the proliferation of pericytes as well as EC. In this report we present evidence that the hypoxic induction of pericyte growth can be ascribed at least in part to vascular endothelial growth factor (VEGF) produced by this very cell type. First, the finding that hypoxia can stimulate the proliferation of pericytes was confirmed by cultivating bovine retinal pericytes in a controlled-atmosphere culture chamber containing various concentrations of oxygen and then assaying pericyte synthesis of DNA. Second, Northern blot analysis revealed that pericyte levels of mRNA encoding VEGF increased as the atmospheric oxygen tension was decreased; this was accompanied by an increase in de novo synthesis of VEGF proteins. Third, pericytes were able to respond to exogenously added VEGF, resulting in a dose-dependent increase in viable cell numbers. Fourth, polyclonal antibodies against VEGF efficiently blocked the hypoxic induction of pericyte growth. Fifth, pericytes expressed the gene for fms-like tyrosine kinase 1 (flt1) as the predominant form of VEGF receptor, and tyrosine phosphorylation of this receptor protein was enhanced when pericytes were exposed to hypoxia, as it was when cells were exposed to VEGF. Sixth, the antisense DNA complement of flt1 mRNA abolished the hypoxia-induced stimulation of pericyte growth. Finally, exogenous VEGF stimulated the migration of pericytes in a dose-dependent manner. The results thus suggest that VEGF, which has been thought to be a specific mitogen for EC, also acts on neighboring pericytes, probably in both autocrine and paracrine manners, and that the hypoxia-induced overproduction of VEGF could promote not only EC sprouting but also the recruitment of pericytes, thereby contributing to the maturation of newly formed microvessels.

NO depletes cellular ATP contents via inactivation of glyceraldehyde-3-phosphate dehydrogenase in PC12 cells

Recently, we demonstrated that nitric oxide (NO) reduces ATP generation via oxidative phosphorylation coupled with the mitochondrial respiratory chain in PC12 cells resulting in induction of apoptotic cell death. To further study the correlation between NO-induced ATP depletion and neuronal death, we examined the effect of NO on glycolytic ATP generation in PC12 cells, a neuronal model. When the oxidative phosphorylation was maximally suppressed by DNP and oligomycin, which are inhibitors of the mitochondrial respiratory chain, the cellular ATP contents were reduced by sodium nitroprusside (SNP). In addition, the cellular ATP contents were further decreased along with a decrease in the activity of glyceraldehyde-3-phosphate dehydrogenase (G3PDH), a key enzyme in the glycolytic pathway. Benzamide, an inhibitor of poly (ADP-ribose) synthetase, could protect the depletion of NAD but had no effect on the depletion of ATP in PC12 cells induced by NO. These results suggest that the depletion of ATP in PC12 cells caused via the inhibition of G3PDH by NO is one of the mechanisms responsible for NO neurotoxicity.

Advanced glycation endproducts inhibit prostacyclin production and induce plasminogen activator inhibitor-1 in human microvascular endothelial cells

Several thrombogenic abnormalities are associated with diabetes. To investigate the underlying molecular mechanisms, we examined the effects of advanced glycation endproducts (AGE), non-enzymatically glycated protein derivatives, on the production of prostacyclin (PGI2), an anti-thrombogenic prostanoid, and of plasminogen activator inhibitor-1 (PAI-1), a fast-acting serine protease inhibitor of fibrinolysis, in human microvascular endothelial cells (EC). Firstly, AGE-bovine serum albumin (BSA) but not non-glycated BSA, was found to considerably decrease the production of PGI2 to about two-thirds of the control value. Secondly, quantitative reverse transcription-polymerase chain reaction showed that AGE-BSA increased the EC levels of mRNA coding for PAI-1, this being associated with a concomitant increase in the immunoreactive PAI-1 contents and the anti-fibrinolytic activity. Thirdly, the effects of AGE on PGI2 and PAI-1 syntheses in EC were found to be mediated by a receptor for AGE (RAGE) because antisense DNA against RAGE mRNA could reverse the AGE effects. Further, it was found that AGE decreased the intracellular cyclic AMP concentrations in EC and that cyclic AMP agonists such as dibutyryl cyclic AMP, forskolin and PGI2 analogue reduced the AGE-stimulated PAI-1 production, suggesting the involvement of cyclic AMP in the AGE-signalling pathway. The results thus suggest that AGE have the ability to cause platelet aggregation and fibrin stabilization, resulting in a predisposition to thrombogenesis and thereby contributing to the development and progression of diabetic vascular complications.

A specific and rapid method for determination of adenosine 3'-monophosphate (3'-AMP) content and 3'-AMP forming enzyme activity in rat liver mitochondria, using reversed-phase HPLC with fluorescence detection

To study the physiological significance of adenosine 3'-monophosphate (3'-AMP), an intracellular P-site inhibitor of adenylate cyclase, in rat liver mitochondria, a specific, rapid and reliable assay method for determination of 3'-AMP and the activity of its forming enzyme is required. 3'-AMP in rat liver was determined to be ca. 23+/-7 nmol/g wet weight, but no 2-deoxy-3'-AMP, another P-site inhibitor of adenylate cyclase, was detected, even when using a reversed-phase HPLC column with a fluorescent-reaction, as established in this study. By using the optimized assay method developed here, 3'-AMP forming enzyme activity in rat crude mitochondrial extract was found to be enhanced by EDTA and inhibited by p-chloromercurybenzoate. The optimum pH was ca. 5.8 and no divalent cation was required for activity. From these results, 3'-AMP forming enzyme(s) in rat liver mitochondria could be classified as acid exoribonuclease, which mainly existed in an active form. The results obtained in this study will help to gain more insight into the physiological roles of 3'-AMP in living systems.

Morphologic and hematologic characteristics of storage pool deficiency in beige rats (Chédiak-Higashi syndrome of rats)

Characterization of beige rats as having a platelet storage pool deficiency (SPD) was undertaken. Platelets from beige rats, an animal model of Chédiak-Higashi syndrome (CHS), completely lacked the ability to aggregate when stimulated with high dosages of collagen (50 micrograms/ml), and lacked secondary aggregation induced by adenosine diphosphate (ADP). Concentrations of ADP, ATP, and serotonin in the platelets of beige rats were significantly lower than those of control rats. However, platelet count remained within normal values. Electron microscopy revealed that platelets had fewer dense granules, whereas other organelles had normal structure. This morphologic and functional evidence confirms that platelets of beige rats have the typical characteristics of SPD.