Vestibular imbalance associated with a lesion in the nucleus prepositus hypoglossi area

BACKGROUND: The nucleus prepositus hypoglossi (NPH) is known to be a neural integrator of horizontal eye movements. Although the role of the human NPH is not well known, it may also function in postural balance, in view of its anatomic connections with the vestibular nuclei and vestibulocerebellum and of lesion studies in experimental animals. OBJECTIVE: To show that the human NPH contributes to vestibular function in addition to eye movement control. DESIGN: Case series. SETTING: University hospital.Patients Six patients with small and discrete brainstem infarctions that predominantly involved the NPH region.Main Outcome Measure Findings on magnetic resonance images. RESULTS: The NPH was affected at the lower pontine level in 2 patients and at the upper medullary level in 4. In addition to gaze-evoked nystagmus, all patients had vertigo, vomiting, and postural ataxia, suggesting vestibular dysfunction. The patients typically fell contralaterally or bilaterally to the lesion side. CONCLUSION: The NPH serves a vestibular function in addition to its oculomotor control function.     

Persistent increase of matrix metalloproteinases in cerebrospinal fluid of tuberculous meningitis

Matrix metalloproteinase (MMP)-2 and MMP-9 were analyzed by gelatin zymography and an enzyme-linked immunosorbent assay (ELISA) in a cerebrospinal fluid (CSF) from patients with tuberculous meningitis (n=24), acute aseptic meningitis (n=23) and the control (n=10). The MMP-2 and MMP-9 levels were significantly higher in the samples from the tuberculous meningitis patients than those from either the aseptic meningitis patients or the controls. In tuberculous meningitis, the patients with late neurologic complications had higher MMP-2 and MMP-9 levels than those without. The persistent increase in the MMP-2 and MMP-9 levels was associated with the development of complications following tuberculous meningitis. Inhibiting the MMPs may be an effective strategy for preventing or reducing the complications in tuberculous meningitis.     

Prenylated flavonoids as tyrosinase inhibitors

In order to find new tyrosinase inhibitors and the effects of prenyl residue on flavonoid molecules, eight prenylated and three synthetic vinylated flavonoids were examined on their inhibitory effect against tyrosinase activity. From the results, kuwanon C, papyriflavonol A, sanggenon D and sophoflavescenol were found to possess the considerable inhibitory activity. Especially, sanggenon D is revealed as a potent inhibitor (IC50 = 7.3 microM), compared to the reference compound, kojic acid (IC50 = 24.8 microM). However, the prenylation with isoprenyl group or the vinylation to flavonoid molecules did not enhance tyrosinase inhibitory activity.     

Dose-dependent effect of alcohol on insulin-like growth factor systems in male rats

1. Chronic alcohol treatment has been reported to be associated with liver and kidney damage. The insulin-like growth factor (IGF) is the major growth factor related to alcohol consumption. However, the effect of alcohol on the IGF system in the liver and kidney has not been fully elucidated. Thus, the present study was conducted to investigate this issue. 2. Alcohol reduced the level of IGF-I in a dose-dependent manner in the serum, liver and kidney. Alcohol also decreased the level of IGF-II in the liver. In contrast, alcohol increased the level of IGF-II in the serum and kidney. These observations were correlated with IGF-I and IGF-II mRNA expression in the liver and kidney. 3. To examine the effect of alcohol on IGF receptors in the liver and kidney, IGF-I receptor mRNA was measured. Alcohol decreased IGF-I receptor mRNA in the liver and kidney. 4. In experiments performed to examine the regulation of IGF-binding proteins (IGFBP), alcohol increased serum levels of IGFBP-1. However, alcohol had no effect on serum levels of IGFBP-2, -3 and -4. These effects were also observed in the liver and kidney. 5. In conclusion, alcohol alters the IGF system in rat liver and kidney in a tissue-specific manner, which may contribute to the metabolic dysfunction following chronic alcohol consumption.     

A new rapid and non-radioactive assay for monitoring and determining the proliferation of retinal pigment epithelial cells

AlamarBlue is used to induce color and fluorescence in the microenvironment of activated cells. The alamarBlue assay was studied to determine if it could be used as a method of evaluating the number of retinal pigment epithelial (RPE) cells. A series of two-fold dilutions of RPE cells were placed into 96-well culture plates. The alamarBlue was added to the culture media after attaching the cells. The absorbance and fluorescence were measured consecutively at various intervals over a period of 24 hr. Cell viability were evaluated by means of the trypan blue exclusion method and flow cytometry using a combination of propidium iodide and annexin V was done to prove the safety of alamarBlue assay to the cells. Both the absorbance and the fluorescence had a linear relationship with the number of RPE cells. Exposing the RPE cells to alamarBlue was not detrimental to the cells. In conclusion, the alamarBlue assay constitutes a one-step, extremely simple, reproducible, economical and non-toxic procedure for evaluating the number of viable RPE cells.     

Effect of nitric oxide on the proliferation of cultured porcine trabecular meshwork cells

To investigate the effect of nitric oxide (NO) on the proliferation of trabecular meshwork (TM) cells, primarily cultured porcine TM cells were exposed to NO donor (SNAP, S-nitroso-N-acetyl-D,L-penicillamine) with and without its inhibitor (L-NAME, Nomega-Nitro-L-arginine methyl ester). The proliferation of TM cells was quantified by a rapid colorimetric assay. Acridine orange/Hoechest 33342 staining and flow cytometry with annexin-PI were done. As a result, NO inhibited the proliferation of TM cells significantly in a dose-dependent manner and this inhibitory effect was abolished by L-NAME. Fluorescent microscopy and flow cytometric analysis revealed that NO induced apoptotic cell death. The current results suggest that NO inhibit the proliferation of TM cells and apoptosis may be involved in some degree.     

Identification of a compound that directly stimulates phospholipase C activity

Phosphoinositide-specific phospholipase C (PLC) plays a pivotal role in the signal transduction of various cellular responses. However, although it is undeniably important that modulators of PLC activity be identified, no direct PLC activity modulator has been identified until now. In this study, by screening more than 10,000 different compounds in human neutrophils, we identified a compound that strongly enhances superoxide-generating activity, which is well known to be PLC-dependent. The active compound 2,4,6-trimethyl-N-(meta-3-trifluoromethyl-phenyl)-benzenesulfonamide (m-3M3FBS) stimulated a transient intracellular calcium concentration ([Ca(2+)](i)) increase in neutrophils. Moreover, m-3M3FBS stimulated the formation of inositol phosphates in U937 cells, indicating that it stimulates PLC activity. The compound showed no cell-type specificity in terms of [Ca(2+)](i) increase in the various cell lines including leukocytes, fibroblasts, and neuronal cells. We also ruled out the possible involvement of heterotrimeric G proteins in m-3M3FBS-stimulated signaling by confirming the following: 1) pertussis toxin does not inhibit m-3M3FBS-induced [Ca(2+)](i) increase; 2) m-3M3FBS does not stimulate cyclic AMP generation; and 3) the inhibition of G(q) by the regulator of G protein-signaling 2 does not affect the m-3M3FBS-induced [Ca(2+)](i) increase. We also observed that m-3M3FBS stimulated PLC activity in vitro. The purified isoforms of PLC that were tested (i.e., beta2, beta3, gamma1, gamma2, and delta1) were activated by m-3M3FBS and showed no isoform specificity. Taken together, these results demonstrate that m-3M3FBS modulates neutrophil functions by directly activating PLC. Because m-3M3FBS is the first compound known to directly activate PLC, it should prove useful in the study of the basic molecular mechanisms of PLC activation and PLC-mediated cell signaling.     

Doxorubicin-based chemotherapy for diffuse large B-cell lymphoma in elderly patients: comparison of treatment outcomes between young and elderly patients and the significance of doxorubicin dosage

BACKGROUND: Although many studies of elderly patients with non-Hodgkin lymphoma have focused on the dose intensity of chemotherapy, few studies have restricted the histologic inclusion criteria such that only patients with diffuse large B-cell lymphoma (DLCL) are considered. In the current study, treatment outcomes for elderly patients (age > or = 60 years) were analyzed, with emphasis on the dose intensity of doxorubicin. METHODS: Between 1994 and 2000, 195 patients with DLCL were treated initially with doxorubicin-based chemotherapy (cyclophosphamide, doxorubicin, vincristine, and prednisone; or cyclophosphamide, vincristine, bleomycin, doxorubicin, procarbazine, and prednisone). Of these patients, 70 were aged 60 years or older. RESULTS: Elderly patients had poorer treatment outcomes than did young patients (5-year survival, 30% vs. 57%; P < 0.001); however, elderly patients who received doxorubicin at dose intensities > or = 10 mg/m2 per week (n = 25) had outcomes (5-year survival, 52%) that were comparable to those of young patients. Among prognostic factors, only International Prognostic Index score (P = 0.022) and dose intensity of doxorubicin (P = 0.039) were found to have significant effects on the overall survival of elderly patients. When the reasons for doxorubicin dose reduction in 45 elderly patients who ultimately received doxorubicin at dose intensities < 10 mg/m2 per week were analyzed, it was found that 20 patients received reduced doses from the start of treatment because of their old age alone; these dose reductions in the 20 cases resulted in poorer treatment outcomes. CONCLUSIONS: Elderly patients with DLCL who received doxorubicin at dose intensities > or = 10 mg/m2 per week had treatment outcomes that were comparable to those of young patients; however, physician bias associated with patient age was found to be related to unnecessary dose reductions. Efforts to maintain doxorubicin dose intensities > or = 10 mg/m2 per week and more objective standards for the selection of elderly patients capable of tolerating doxorubicin-based regimens are required.