Biocompatible inkjet printing technique for designed seeding of individual living cells

Inkjet printers are capable of printing at high resolution by ejecting extremely small ink drops. Established printing technology will be able to seed living cells, at micrometer resolution, in arrangements similar to biological tissues. We describe the use of a biocompatible inkjet head and our investigation of the feasibility of microseeding with living cells. Living cells are easily damaged by heat; therefore, we used an electrostatically driven inkjet system that was able to eject ink without generating significant heat. Bovine vascular endothelial cells were prepared and suspended in culture medium, and the cell suspension was used as "ink" and ejected onto culture disks. Microscopic observation showed that the endothelial cells were situated in the ejected dots in the medium, and that the number of cells in each dot was dependent on the concentration of the cell suspension and ejection frequency chosen. After the ejected cells were incubated for a few hours, they adhered to the culture disks. Using our non-heat-generating, electrostatically driven inkjet system, living cells were safely ejected onto culture disks. This microseeding technique with living cells has the potential to advance the field of tissue engineering.     

Inhibitory effect of glucocorticoids on human-cloned 5-hydroxytryptamine3A receptor expressed in xenopus oocytes

BACKGROUND: Methylprednisolone, dexamethasone, and other glucocorticoids have been found effective against nausea and vomiting induced by chemotherapy and surgery. Although the specific 5-hydroxytriptamine3 (5-HT3) receptor antagonists such as ondansetron and ramosetron are used as antiemetics, reports show that the use of 5-HT3 receptor antagonists with some glucocorticoids brings additional effects. Glucocorticoids are reported to be antiemetic. The effect of glucocorticoids on 5-HT3 receptor, however, has not been well characterized. This study was designed to examine whether dexamethasone and methylprednisolone had direct effects on human-cloned 5-HT3A receptor expressed in Xenopus oocytes. METHODS: Homomeric human-cloned 5-HT3A receptor was expressed in Xenopus oocytes. The authors used the two-electrode voltage-clamping technique to study the effect of methylprednisolone and dexamethasone on 5-HT-induced current. RESULTS: Both dexamethasone and methylprednisolone concentration-dependently attenuated 5-HT-induced current. Dexamethasone inhibited 2 microm 5-HT-induced current, which was equivalent to EC30 concentration for 5-HT3A receptor, with an inhibitory concentration 50% of 5.29 +/- 1.02 microm. Methylprednisolone inhibited 2 microm 5-HT-induced current with an inhibitory concentration 50% of 1.07 +/- 0.15 mm. The mode of inhibition with either dexamethasone or methylprednisolone was noncompetitive and voltage-independent. When administered together with the 5-HT3 receptor antagonists, ramosetron or metoclopramide, both glucocorticoids showed an additive effect on 5-HT3 receptor. CONCLUSION: The glucocorticoids had a direct inhibitory effect on 5-HT3 receptors. The combined effect of glucocorticoids and the 5-HT3 receptor antagonists seems additive.     

Measurement of carpal canal and median nerve pressure in patients with carpal tunnel syndrome

Carpal tunnel syndrome is a compression neuropathy wherein the median nerve is compressed inside of the carpal canal. Its diagnosis is made clinically, electrophysiologically, and sometimes by carpal canal pressure measurement. The objective of surgical management of this condition is the decompression of the median nerve. We usually measure carpal canal pressure preoperatively and postoperatively using a continuous infusion technique for diagnoses as well as for postoperative evaluation of decompression following our Universal Subcutaneous Endoscope system procedure. To evaluate whether our procedure effectively decompressed the median nerve, we measured intraneural pressure preoperatively and postoperatively in the resting position, with active power grip, and in the Okutsu test position. Correlation between the carpal canal pressure and intraneural median nerve pressure was statistically analyzed using the Kendall rank correlation coefficient (n = 157 hands). A significant correlation was present preoperatively in resting position and postoperatively with active power grip and in the Okutsu test position. Because of this correlation, we conclude that our endoscopic operative procedure effectively decompresses the median nerve and that simple carpal canal pressure measurement is sufficient to confirm diagnoses and to evaluate the status of postoperative decompression.     

In vitro inhibition of recombinant ligand-gated ion channels by high concentrations of milnacipran

Rationale Tricyclic antidepressants are known to inhibit various ligand-gated ion-channel (LGIC) receptors, and some of their clinical features may be associated with this activity. The effects of milnacipran, a selective inhibitor of the reuptake of serotonin and noradrenaline, on LGIC receptors have not yet been investigated on such ion-channel receptors.Objectives To determine the in vitro effect of milnacipran on four recombinant LGIC receptors, nicotinic acetylcholine, N-methyl-d-aspartate, -amino butyric acid (GABA) and 5-hydroxytryptamine_3A receptors.Methods Receptors were expressed in Xenopus oocytes and LGIC activity measured using a two-voltage clamp technique.Results There was no interaction at the GABA receptor. The results at the other LGIC receptors showed that they could be inhibited by high concentrations of milnacipran.Conclusions At high concentrations, milnacipran can inhibit certain LGICs. It is, however, unlikely that these interactions have any clinical consequence under normal therapeutic conditions, since the concentrations required are considerably higher than those achieved in plasma of treated patients.     

Comparison of the effects of prophylactic antibiotic therapy and cost-effectiveness between cefazolin (CEZ) and Sulbactam/Ampicillin (SBT/ABPC) in gastric cancer surgery employing clinical pathway

The present study was designed to investigate the effects of prophylactic antibiotic therapy and the cost-effectiveness of Cefazolin (CEZ) and Sulbactam/Ampicillin (SBT/ABPC) in gastric cancer surgery employing clinical pathway. 157 patients (62 in the CEZ group and 95 in the SBT/ABPC group), who underwent surgery for gastric cancer at the First Department of Surgery of our hospital, were investigated. There was no significant difference between the groups with regard to sex, age, incidence of complication, stage of cancer, surgical method, operative time and blood loss, length of hospitalization, the appearance of systemic inflammatory response syndrome (SIRS), changes body temperature, white blood cell count (WBC), C-reactive protein (CRP), or clinical outcome of postoperative care by a nurse during post-operation for 7 days. The prophylactic effect of infection was also no different between the CEZ (69.4%) and SBT/ABPC (69.5%) groups. In contrast, decision analysis strongly indicated that the anticipate cost of antibiotics was higher in the latter group (yen 20402) than in the CEZ group (yen 15556), suggesting that the prophylactic effect of CEZ may be more cost-effective. Thus, evaluations of pharmacotherapy from the aspect of cost may be one of the important responsibility of hospital pharmacists in the future.     

Evidence for the involvement of GABA(A) receptor blockade in convulsions induced by cephalosporins

There is accumulating evidence that most beta-lactam antibiotics (i.e., cephalosporins and penicillins) have some degree of convulsive activity, both in laboratory animals as well as in clinical settings. The proposed mechanism is suppression of inhibitory postsynaptic responses, mainly mediated by gamma-amino butyric acid (GABA)(A)-receptors (GABA(A)-R). However, comprehensive studies on the convulsive activities of various beta-lactam antibiotics in vivo and in vitro have not been performed. We have therefore examined the convulsive activities of seven different cephalosporins using both in vivo and in vitro models: intracerebroventricular (ICV) administration in mouse; [(3)H]muscimol binding assay (BA) in mouse brain synaptosome; and inhibition of recombinant mouse alpha1beta2gamma2s GABA(A)-Rs in Xenopus oocyte (GR). The rank orders of convulsive activities in mouse (cefazolin>cefoselis>cefotiam>cefpirome>cefepime>ceftazidime>cefozopran) correlated with those of inhibitory potencies on [(3)H]muscimol binding and GABA-induced currents of GABA(A)-R in vitro, with correlation coefficients of ICV:GR, ICV:BA and BA:GR of 0.882, 0.821 and 0.832, respectively. In contrast, none of the antibiotics had affinities for N-methyl-D-aspartate (NMDA) receptors nor facilitatory actions on NMDA receptor-mediated current in oocytes. These results clearly demonstrate that the mechanism of cephalosporin-induced convulsions is mediated predominantly through the inhibition of GABA(A)-R function and not through NMDA receptor modulation.     

Genome-wide searches for blood pressure quantitative trait loci in the stroke-prone spontaneously hypertensive rat of a Japanese colony

OBJECTIVES: Although several quantitative trait loci for blood pressure have been reported in stroke-prone spontaneously hypertensive rats (SHRSP), the results are not always concordant among different crosses. To evaluate potential confounding factors in linkage analysis, we performed genome-wide screens in F2 populations derived from SHRSP and Wistar-Kyoto rats of a Japanese colony. METHODS: Two F cohorts were independently produced: F2-1 (110 male and 110 female rats), and F2-2 (174 male and 184 female rats). Blood pressure was measured longitudinally (from 2 to 5 months of age and 1 month after salt-loading) in F2-1, while it was measured at 13 weeks of age in F2-2. Subsequent to an initial screen with 251 markers in F2-1 male progeny, 170 markers were selected and characterized in the remaining populations. RESULTS: When 578 rats were analyzed together, markers from five chromosomal regions showed significant linkage to blood pressure at 13 weeks of age. The strongest and the most consistent linkage was found on rat chromosome 1 (a maximal log of the odds score reached 8.3). In the other regions, the degree of linkage was more prominent in either of sexes. Some evidence of age-specific and sex-specific linkage was detected in five additional regions in the F2-1 cohort. In the Japanese colony, however, there was no significant linkage to several chromosomal regions previously reported in other SHRSP colonies. CONCLUSIONS: Our data provide solid evidence of a chromosome-1 linkage and demonstrate the importance of aging, sex, and dietary manipulation in linkage analysis. Also, the combination of parental rat strains seems to be critical when searching for blood pressure quantitative trait loci.