High-Resolution Magic Angle Spinning Nuclear Magnetic Resonance Spectroscopy for the Metabolic Assessment of Acute Rejection After Cardiac Transplantation in Rats.

PURPOSE: To evaluate the potential of high-resolution magic angle spinning (HR-MAS) 1H nuclear magnetic resonance (NMR) spectroscopy for metabolite characterization and the differentiation of acute rejection after heart transplantation in rat models. METHODS: We transplanted syngeneic heart grafts from Lewis rats (n = 4) and allogeneic heart grafts from F344 rats (n = 4) heterotopically into Lewis recipients. On day 7 postoperatively, the transplanted hearts were harvested for ex vivo 1H NMR spectroscopy and HR-MAS 1H NMR spectroscopy. 1H NMR spectroscopy and HR-MAS 1H NMR spectroscopy were performed at 4.7 T and 11.7 T, respectively. Metabolomic profiles contributing to the differentiation of allogeneic and syngeneic graft groups were statistically assessed by orthogonal partial least squares discriminant analysis (OPLS/O2PLS-DA). Metabolite concentrations were normalized by total spectral intensities and were compared using Mann-Whitney U tests. RESULTS: One allogeneic graft that showed extensive necrotic change suggesting graft failure was excluded from the statistical analysis of the NMR spectroscopy. In the 4.7-T 1H NMR spectroscopy, the creatine peak was decreased in the allogeneic group. The PLS-DA and OPLS/O2PLS-DA score plot demonstrated good discrimination of the allogeneic graft group from syngeneic graft group. The concentrations of creatine, myo-inositol, glucose, niacinamide, hypoxanthine, inosine, and glutamine were significantly decreased in the allogeneic graft group, whereas the concentrations of glycine, phosphoethanolamine, xanthine, sn-glycero-3-phosphocholine, leucine, valine, and tyrosine were significantly increased (P < .05). CONCLUSIONS: HR-MAS 1H NMR spectroscopy can metabolically characterize the acute rejection of heart transplantation.

Use of Jebsen Taylor Hand Function Test in evaluating the hand dexterity in people with Parkinson's disease.

OBJECTIVES: To investigate the test-retest reliability of JTT in older patients with Parkinson's disease (PD); and to compare the Jebsen Taylor Hand Function Test (JTT) scores between PD and healthy subjects. STUDY DESIGN: Cross-sectional comparative study. METHODS: Fifteen PD and fifteen healthy subjects performed the JTT and the time taken to complete the JTT was recorded. RESULTS: Test-retest reliabilities of JTT subtests and total score of both dominant and non-dominant hand were good to excellent (ICCs = 0.77-0.97) except J5 checkers which had moderate reliability. PD subjects required significantly longer time to finish subtests and the whole JTT (p < 0.05), except the subtest J1 writing of dominant hand that showed marginal significance (p = 0.059). CONCLUSION: JTT is a reliable and easily available assessment tool for assessing the hand function of PD subjects. PD subjects took a longer time to complete the JTT, suggesting that they have deficits in gross and fine functional dexterity.

The effects of 188 rhenium-filled balloon dilation following bare stent placement in a rabbit oesophageal model.

The objective of the study was to evaluate the efficacy of beta-radiation using a rhenium-188-mercaptoacetyltriglycine ((188)Re-MAG(3))-filled balloon for preventing tissue hyperplasia secondary to bare stent placement in a rabbit oesophageal model. Immediately following bare stent placement in 30 rabbits, 10 underwent conventional contrast-filled balloon dilation (control group, Group I), and 20 underwent (188)Re-MAG(3)-filled balloon dilation, with half of these receiving 20 Gy (Group II) and half receiving 40 Gy (Group III) at a 1 mm tissue depth. Diameter percentage stenosis was calculated using oesophagography performed before sacrifice 6 weeks later. Gross and microscopic findings were obtained at both an area of untreated oesophageal tissue and a mid-stent area. Apoptosis and an apoptotic index in the mid-stent area were evaluated in two rabbits from each group. 13 rabbits survived the scheduled 6-week stent placement. Diameter percentage stenosis for Groups II and III was significantly lower than for Group I. The oesophageal mucosa showed nodularity in Group I and smoothness in Groups II and III. Oesophageal mucosal erythema (n = 9) and perforations (n = 10) were observed in Groups II and III only. Mid-stent epithelial layer thickness and muscularis propria destruction differed between the three groups (p<0.05). Apoptosis was increased and the apoptotic index was higher in Groups II and III than in Group I. In conclusion, (188)Re-MAG(3)-filled balloon dilation was effective in preventing tissue hyperplasia secondary to bare stent placement, but at the cost of an increased risk of radiation-induced mucosal inflammation and perforation, in a rabbit oesophageal model. Apoptosis may be the mechanism underlying this irradiation-induced suppression of tissue hyperplasia.

Downregulation of Bim by brain-derived neurotrophic factor activation of TrkB protects neuroblastoma cells from paclitaxel but not etoposide or cisplatin-induced cell death.

Chemoresistance and increased expression of TrkB and brain-derived neurotrophic factor (BDNF) are biomarkers of poor prognosis in tumors from patients with neuroblastoma (NB). Previously, we found BDNF activation of TrkB through PI3K/Akt protects NB from etoposide/cisplatin-induced cell death. In this study, the role of Bim, a proapoptotic protein, was investigated. Bim was involved in paclitaxel but not etoposide or cisplatin-induced cell death in NB cells. Pharmacological and genetic studies showed that BDNF-induced decreases in Bim were regulated by MAPK and not PI3K/Akt pathway. Both MAPK and PI3K pathways were involved in BDNF protection of NB cells from paclitaxel-induced cell death, while PI3K predominantly mediated BDNF protection of NB cells from etoposide or cisplatin-induced cell death. These data indicate that different chemotherapeutic drugs induce distinct death pathways and growth factors utilize different signal transduction pathways to modulate the effects of chemotherapy on cells.

Genotyping CagA, VacA subtype, IceA1, and BabA of Helicobacter pylori isolates from Korean patients, and their association with gastroduodenal diseases.

The genetic status of cagA, vacA subtype, iceA1, and babA, and the relationship to gastroduodenal diseases were assessed in Helicobacter pylori isolates in Korea. Seventy-six strains of H. pylori were isolated from the antrum and the corpus of 41 adult patients (22 with peptic ulcer and 19 with gastritis). The cagA, iceA1, and babA genes were assessed by polymerase chain reaction and the vacA subtypes were determined by reverse hybridization-line probe assay. The positive rates of 349-bp cagA, 208-bp cagA, iceA1, and babA genes were 97.4%, 96.1%, 84.2%, and 36.1%, respectively. The vacA s1a, s1b, s1c, and s2 variants were detected in 11.8%, 3.9%, 80.4%, and 1.3%, respectively. m1 (78.9%) is more prevalent than m2 (5.3%). The most common vacA genotype was s1c/m1 (61.9%), and 14 isolates (18.4%) contained mixed vacA genotypes from a single biopsy specimen. Twenty-one (60%) of 35 patients were infected with more than two strains of different cagA, iceA1, babA, and vacA genotypes. None of cagA, iceA1, babA, and vacA s1/m1 were associated with peptic ulcer. In conclusion, most H. pylori isolates in Korea carry cagA, iceA1, and vacA s1c/m1 genes, and reside with multiple strains. These genes do not correlate with the peptic ulcer in the Korean patients.

Tensile, shear and cleavage bond strengths of alginate adhesive.

OBJECTIVES: This study determined the effect of alginate adhesive on various bond strengths of alginate to stainless steel. METHODS: Three test assemblies were designed and machined in stainless steel for tension, shear and cleavage tests. Alginate adhesive (Fix) was applied thinly and dried for 5 min. Alginate (Blueprint) was then loaded and allowed to set for 5 min before testing. The force at failure was measured by an Instron machine with a cross-head speed of 50 mm min(-1). RESULTS: Breaking stresses of alginate without adhesive were found to be 65 kPa (tension), 31 kPa (shear) and 10 kPa (cleavage). The bond strengths of Blueprint with Fix were 100 kPa (tension), 42 kPa (shear) and 37 kPa (cleavage) giving improvements of 53%, 37% and 270% respectively (p < 0.05). CONCLUSIONS: Alginate adhesive increases the bond strength of alginate, particularly cleavage, to stainless steel.

Selectivity of oxomemazine for the M1 muscarinic receptors.

The binding characteristics of pirenzepine and oxomemazine to muscarinic receptor were studied to evaluate the selectivity of oxomemazine for the muscarinic receptor subtypes in rat cerebral microsomes. Equilibrium dissociation constant (KD) of (-)-[3H]quinuclidinyl benzilate([3H]QNB) determined from saturation isotherms was 64 pM. Analysis of the pirenzepine inhibition curve of [3H]QNB binding to cerebral microsome indicated the presence of two receptor subtypes with high (Ki = 16 nM, M1 receptor) and low (Ki = 400 nM, M3 receptor) affinity for pirenzepine. Oxomemazine also identified two receptor subtypes with about 20-fold difference in the affinity for high (Ki = 84 nM, OH receptor) and low (Ki = 1.65 microM, OL receptor) affinity sites. The percentage populations of M1 and M3 receptors to the total receptors were 61:39, and those of OH and OL receptors 39:61, respectively. Both pirenzepine and oxomemazine increased the KD value for [3H]QNB without affecting the binding site concentrations and Hill coefficient for the [3H]QNB binding. Oxomemazine had a 10-fold higher affinity at M1 receptors than at M3 receptors, and pirenzepine a 8-fold higher affinity at OH receptors than at OL receptors. Analysis of the shallow competition binding curves of oxomemazine for M1 receptors and pirenzepine for OL receptors yielded that 69% of M1 receptors were of OH receptors and the remaining 31% of OL receptors, and that 29% of OL receptors were of M1 receptors and 71% of M3 receptors. However, M3 for oxomemazine and OH for pirenzepine were composed of a uniform population. These results suggest that oxomemazine could be classified as a selective drug for M1 receptors and also demonstrate that rat cerebral microsomes contain three different subtypes of M1, M3 and the other site which is different from M1, M2 and M3 receptors.

Torsional stability of the lumbosacral junction. Significance of the iliolumbar ligament.

Previous study has shown that the iliolumbar ligament is important in restraining flexion, extension, and lateral bending of L5 on S1, and its effect on axial rotation was not apparent at 6 N-m of loading. An apparatus was devised to further evaluate its role in relation to the torsional stability of the lumbosacral junction. Torque-rotation characteristics were studied with 24 cadaveric lumbosacral-pelvic specimens. The specimens were divided into three groups. In Group A, the "facet joints," lumbosacral disc and the iliolumbar ligament were all intact. In Group B, the "facet joints" were removed, and in Group C, both the "facets" and the iliolumbar ligament were removed. The results indicated that the ligament was important in maintaining torsional stability of the lumbosacral junction and contributed to 35.2% of the normalized elastic strain energy of the junction.

Studies on suppressor factors produced by T-cell hybridomas. I. Characterization of antigen-specific suppressor factors.

Antigen-specific and antigen-nonspecific suppressor T cells were generated when spleen cells prepared from C57BL/6J (H-2b) were incubated with trinitrophenylated polyacrylamide beads (TNP-PAA) in vitro. T hybridomas were prepared by fusion of spleen cells cultured with TNP-PAA for 4 days and the thymoma cell line BW5147. More than 100 hybridomas were generated, and 15 of them suppressed the anti-TNP PFC response of fresh spleen cells cultured with TNP-PAA. The suppression was antigen specific with three of these five hybridoma supernatants tested. Hybridomas that caused antigen-specific suppression secrete factors which bring about suppression of the anti-TNP PFC response by spleen cells cultured with TNP-PAA. These hybridoma supernatants which cause antigen-specific suppression typically depressed the anti-TNP PFC response by 60% while depressing anti-SRBC PFC response by only 10%. The antigen-specific suppressor factors were bound to a TNP-BGG column but not to a BGG column. The suppressor factors, purified by affinity chromatography on a TNP-BGG column, were bound to anti-I-Jb antibody.

The biomechanical functions of the iliolumbar ligament in maintaining stability of the lumbosacral junction.

The iliolumbar ligament is one of the three lumbopelvic ligaments. Recent study has shown that the ligament is not present at birth and is formed from metaplasia of the quadratus lumborum muscle at the end of the first decade. To study the biomechanical functions of this ligament, an apparatus was developed using linear variable differential transformers. Twenty fresh cadaveric specimens of the lumbosacral pelvis were tested. The flexibility of the intact lumbar segment was studied before and after the ligaments were divided. Flexion of L5 on S1 was mainly controlled by the posterior band and lateral bending by the anterior band of the ligament. When the L5-S1 disc was degenerated, total division of the ligaments reduced extension during loading. Its effect on torsion was not evident from this study.