The influence of interfering input from the peroneal nerve on tibial-nerve somatosensory evoked potential.

Using a conditioning-test paradigm, we studied the recovery function of tibial nerve somatosensory evoked potentials (SEPs) conditioned by preceding peroneal nerve stimulation. The inter-stimulus intervals (ISIs) ranged from 0 to 400 msec, where 0 msec indicated simultaneous arrival of tibial and peroneal nerve volleys at the L1 spine. The recovery curve was W-shaped, showing two peaks of SEP suppression, maximum at 6 msec ISI (1st phase) and 50-75 ISI msec (2nd phase). In the 1st phase suppression, we found distinct differences in wave forms between 0-2 msec ISI and 4-6 msec ISI. At 0-2 msec ISI, P40-N50-P60 amplitude decreased and latencies shortened, while P31 and N35 were unchanged. At 4-6 msec ISI, all peaks, possibly excluding P31, were markedly depressed. We attribute the former change to an "occlusive effect" and the latter to an "inhibitory effect," each mediated via a central synaptic network between the two nerves. The attenuation of the 2nd but not the 1st phase suppression by peroneal nerve block distal to the stimulating electrodes provided evidence that the 2nd phase suppression resulted primarily from interfering afferent signals generated by peroneal nerve peripheral receptors, activated by foot movement.     

Long-term observation of immunologic reconstitution after allogeneic bone marrow transplantation: differences in recovery among functional T cell subsets

A 27-year-old male with acute lymphoblastic leukemia in the first relapse received allogeneic marrow graft from an HLA-identical sister on April 28, 1978. We studied in vitro immunologic parameters such as T cell surface phenotypes, proliferative response to PHA and Con A; T cell suppressor and helper function for in vitro immunoglobulin production stimulated with pokeweed mitogen serially after the transplantation. Despite a low OKT4/OKT8 ratio for more than 5 yrs after marrow grafting, proliferative response to PHA recovered to normal 4 yrs and 9 months post-transplant. In contrast, proliferative response to Con A did not recover. T cell suppressor function induced by Con A had recovered at 3 yrs 6 months; however helper T cell function took longer to recover. These findings suggest differences in functional recovery of T cell subsets following allogeneic marrow transplantation.     

Folate receptor allows cells to grow in low concentrations of 5-methyltetrahydrofolate.

The folate receptor mediates the uptake of 5-methyltetrahydrofolate in certain cultured cells by a process called potocytosis. When these cells are grown in physiological concentrations of folate, the receptor increases the efficiency of vitamin uptake by 30-fold. We now show that PAM 212 cells, a mouse keratinocyte cell line, are unable to grow in 1 nM 5-methyltetrahydrofolate unless they express a functional folate receptor. These results suggest that under certain conditions, tissue cells in the body may depend on the folate receptor to obtain enough 5-methyltetrahydrofolate for growth.     

Hypercholesterolemia as a part of chronic GVHD after allogeneic stem cell transplantation

A 45-year-old female with acute myelogenous leukemia (AML-M6) received an allogeneic stem cell transplantation from an HLA-identical sibling donor in June 2002. Prophylaxis against graft-versus-host disease (GVHD) consisted of cyclosporine (CsA) and short-term methotrexate. Acute GVHD did not occur and CsA was discontinued on day 145 after transplantation. However, soon thereafter she suffered from conjunctivitis, stomatitis and liver dysfunction with hypercholesterolemia and was diagnosed as having chronic GVHD. The liver dysfunction and hypercholesterolemia failed to improve despite the administration of CsA and prednisolone. Atrovastatin was not effective and immunosuppressive therapy for two months including ursodeoxycholic acid finally improved the jaundice and hypercholesterolemia. Although lipid metabolism analysis in this case disclosed the same findings as in other intrahepatic cholestatic liver diseases, the results show that the improvement of hypercholesterolemia in chronic GVHD needs the same treatment as chronic GVHD.     

Folate receptors targeted to clathrin-coated pits cannot regulate vitamin uptake.

Potocytosis is an endocytic process that is specialized for the internalization of small molecules. Recent studies on the uptake of 5-methyltetrahydrofolate by the folate receptor have suggested that the glycosyl-phosphatidylinositol anchor on this protein causes it to cluster and be internalized by caveolae instead of coated pits. To test this hypothesis directly, we have constructed a chimeric folate receptor that has the glycosyl-phosphatidylinositol anchor replaced with the transmembrane domain and cytoplasmic tail of the low density lipoprotein receptor. The cells with wild-type receptors delivered 5-methyltetrahydrofolate to the cytoplasm more rapidly than did cells expressing the chimeric receptor. This suggests that efficient delivery to the cytoplasm depends on caveolae. In sharp contrast to cells with wild-type folate receptors, cells internalizing folate by clathrin-coated pits were unable to decrease vitamin uptake when they were either folate replete or confluent.     

PET/CT imaging of renal intravascular large B-cell lymphoma

Clinical and Experimental Nephrology -     

Clinical value of abnormal findings on brain magnetic resonance imaging in patients with intravascular large B-cell lymphoma

To investigate the prevalence and clinical value of abnormal findings detected via brain magnetic resonance imaging (MRI) in patients with intravascular large B-cell lymphoma (IVLBCL), we identified 33 patients with IVLBCL pathologically diagnosed and evaluated with pretreatment brain MRI. Abnormal findings on brain MRI were categorized into four patterns: (1) hyperintense lesion in the pons on T2-weighted imaging (T2WI), (2) nonspecific white matter lesions, (3) infarct-like lesions, and (4) meningeal thickening and/or enhancement. Abnormal cerebral findings were detected in 29 patients (87.9%). Hyperintense lesion in the pons was the most common finding (n?=?19 (57.6%) patients), followed by nonspecific white matter lesions (n?=?14 (42.4%) patients), infarct-like lesions (n?=?8 (24.2%) patients), and meningeal thickening and/or enhancement (n?=?4 (12.1%) patients). Impaired consciousness was seen in most of the patients with infarct-like lesions (87.5%) but less frequently in patients with hyperintense lesion in the pons (47.4%). We reviewed brain MRI findings in 39 patients with diffuse large B cell lymphoma with central nervous system (CNS) involvement and/or high-risk extranodal lesions for CNS involvement as a control group. In contrast to the patients with IVLBCL, no patient had hyperintense lesion in the pons in the control group (P?<?0.001). Follow-up brain MRI revealed improvement of abnormal findings in most of the patients who responded to chemotherapy. This study highlighted the diagnostic implication of hyperintense lesion in the pons on T2WI and the clinical usefulness of pretreatment brain MRI in IVLBCL even in patients without impaired consciousness.     

Clinical Effectiveness of Tolvaptan in Patients with Acute Decompensated Heart Failure and Renal Failure: Design and Rationale of the AQUAMARINE Study

Purpose

Over half of all admitted acute decompensated heart failure (ADHF) patients have renal failure. Although diuretics represent the mainstay of treatment strategy even in this population, there are unmet needs for safer and more effective treatment. Tolvaptan is a vasopressin-2 receptor antagonist, and we hypothesized that adding tolvaptan to standard diuretic therapy would be more effective in ADHF patients with renal function impairment.

Methods

The Answering question on tolvaptan’s efficacy for patients with acute decompensated heart failure and renal failure (AQUAMARINE) is a multicenter, randomized controlled clinical trial, which will enroll 220 patients from 17 hospitals in Japan. ADHF patients whose estimated glomerular filtration rate is above 15 and below 60 mL/min/1.72 m² will be randomly assigned within 6 h after admission to usual care with furosemide or tolvaptan add-on therapy. Primary endpoint is achieved urine output within 48 h. Secondary endpoints include dyspnea relief measured by 7-points Likert scale, incidence of worsening renal function, dose of furosemide used within 48 h, and changes of brain natriuretic peptide.

Conclusion

This study is the first multicenter study in Japan to evaluate clinical effectiveness of tolvaptan add-on therapy in ADHF patients with renal failure. The results of this study address the treatment strategy of this high-risk population (UMIN Clinical Trial Registry Number: UMIN000007109).     

Peripheral microvascular dysfunction predicts residual risk in coronary artery disease patients on statin therapy

Objective

Although lowering of low-density lipoprotein cholesterol (LDL-C) by statins is essential in treatment of coronary artery disease (CAD) patients, there is considerable residual risk of secondary coronary artery events (CAE). We examined whether microvascular dysfunction (MiD), measured by peripheral artery tonometry (PAT), can predict prognosis of CAD patients previously treated with statins.

Methods

We measured log-transformed reactive hyperemia index (L_RHI) in 213 CAD patients who had already achieved LDL-C <100 by statin therapy. Patients were followed-up for secondary CAE for a median of 2.7 years. Patients were divided into two groups: L_RHI ≥ 0.54 (n = 99) and L_RHI < 0.54 (n = 114).

Results

During follow-up, CAE occurred in 4 (4.0%) patients in the L_RHI ≥ 0.54 group and 18 (15.8%) patients in the L_RHI < 0.54 group (P = 0.006). Cox regression analysis indicated that L_RHI was an independent predictor for CAE even after adjustment by Framingham traditional risk factors (FRF; age, T-C/HDL-C ratio, systolic blood pressure, diabetes, current smoker, and gender) and estimated glomerular filtration rate (eGFR) for secondary CAE (HR 0.79, 95% CI: 0.66–0.95). ROC analysis for CAE prediction showed that the AUC for models including FRF only, FRF + eGFR, and FRF + eGFR + L_RHI were 0.60, 0.71, and 0.77, respectively. Moreover, adding eGFR to FRF only (0.63, P = 0.003) and adding L_RHI to the FRF + eGFR model were associated with significant improvement of net reclassification improvement (0.79, P = 0.007).

Conclusion

MiD measured by non-invasive PAT adds incremental predictive ability to traditional risk factors for prognosis of CAD patients successfully treated with statins.