Age-related changes in the distribution of Na(v)1.1 and Na(v)1.2 in rat cerebellum

Modification of sodium channel availability and behavior is obviously a good candidate for alteration of action potential observed during aging. In the present study, we revealed age-related alterations in the expression of voltage-gated Na+ (Na(v)) channel in rat cerebellum by immunohistochemistry. In the cerebellar cortex of aged rats, Na(v)1.1 immunoreactivity in Purkinje cell bodies was highly increased, whereas granule cells showed lower staining intensity. In the cerebellar nuclei of aged rats, Na(v)1.1 and Na(v)1.2 expression was specifically increased in the cerebellar output neurons, which was confirmed by image analysis. The first demonstration of age-related changes in Na(v) channel expression contributes to our understanding of the mechanisms responsible for alteration in synaptic transmission during aging.     

Effects of morphine on mechanical allodynia in a rat model of central neuropathic pain

We examined whether morphine reduced the behavioral signs of neuropathic pain below level induced by T13 spinal hemisection in rats. In order to examine the effect of morphine on the mechanical allodynia, morphine alone, morphine with naloxone and saline were administered intraperitoneally and intrathecally and behavioral tests were conducted. In systemic injection, mechanical allodynia was reduced only when a higher concentration of morphine (5 mg/kg) was used. Intrathecally injected morphine (0.5, 1, 2, 5 microg) reduced mechanical allodynia dose-dependently. It is suggested that systemic morphine has limited effect on mechanical allodynia but direct spinal administration of morphine is more effective in controlling central pain following spinal cord injury.     

Education and the association between vascular risk factors and cognitive function: a cross-sectional study in older Koreans with cognitive impairment

BACKGROUND/OBJECTIVE: The association between hypertension, diabetes, and worse cognitive function has been reported to be stronger in groups with low levels of education. Using data from a cross-sectional community survey of Korean elders, we sought to investigate this within a sample with relative cognitive impairment. METHODS: The sample consisted of 341 participants with Mini-Mental State Examination (MMSE) (Korean version) scores of 24/30 or below. Previous diagnoses were ascertained and participants were examined for resting blood pressure and nonfasting blood glucose and cholesterol. RESULTS: After adjustment for age, occupation, physical dependence, and cholesterol levels, worse cognitive function (MMSE score <21) within the sample was associated with raised systolic blood pressure, raised glucose levels, and a previous diagnosis of diabetes. These associations were significant only in participants with no formal education. In this group the adjusted odds ratios for worse cognitive function were 1.18 (95% confidence interval [CI] 1.04-1.34) for each 10 mmHg increase in systolic blood pressure and 3.47 (1.14-10.6) for a previous diagnosis of diabetes. Odds ratios for the group with previous education were 0.99 (0.81-1.21) and 1.82 (0.48-6.92), respectively. CONCLUSION: The association between risk factors for cerebrovascular disease and cognitive impairment appears to be particularly strong in people with lower educational attainment.     

Sialolithiasis in the sublingual gland

Sialolithiasis is a major cause of salivary gland dysfunction. The submandibular gland is the most common site followed by the parotid gland. The sublingual gland and minor glands are very rare sites for stone formation. This paper describes a case of multiple sialoliths arising in the sublingual gland. They presented on the right floor of the mouth. The sublingual gland and sialoliths were completely removed with careful preservation of the lingual nerve and Wharton's duct. This was an uncommon sialolithiasis of the sublingual gland in a 14-year-old female.     

The need for long-term audiologic follow-up of neonatal intensive care unit (NICU) graduates

OBJECTIVE: To evaluate the adequacy of newborn hearing screening in the identification of hearing loss in post-neonatal intensive care unit (NICU) infants. METHODS: Eighty-two post-NICU infants who had initially passed automated auditory brainstem response (AABR) screening were studied prospectively between November 1997 and July 1999. Tympanometry and transient evoked otoacoustic emissions (TEOAE) were used to evaluate middle ear status and screen the hearing of subjects when they were seen routinely in the Mary L. Johnson Infant Development Clinic, where NICU graduates are followed at our institution. TEOAEs were not performed in subjects with abnormal tympanometry, defined as negative pressures greater than 200 daPa or flat tympanograms. RESULTS: Of the 82 subjects, 31 (37%) had abnormal tympanometry in at least one ear, with 24 (29%) exhibiting abnormal values bilaterally. Two subjects were identified with delayed-onset or previously undiagnosed sensorineural hearing loss. One had a history of persistent pulmonary hypertension (PPHN) and extracorporeal membrane oxygenation. The other infant had no risk factors for sensorineural hearing loss. CONCLUSIONS: Our data indicate that newborn hearing screening programs may not provide adequate vigilance for NICU graduates. The high incidence of abnormal middle ear status and the identification of delayed-onset hearing loss in an infant without known risk factors highlights the need for close audiologic and speech/language follow-up in the post-NICU population.     

Fume generation and content of total chromium and hexavalent chromium in flux-cored arc welding

This study was performed to investigate the fume generation rates (FGRs) and the concentrations of total chromium and hexavalent chromium when stainless steel was welded using flux-cored arc welding (FCAW) with CO2 gas. FGRs and concentrations of total chromium and hexavalent chromium were quantified using a method recommended by the American Welding Society, inductively coupled plasma-atomic emission spectroscopy (NIOSH Method 7300) and ion chromatography (modified NIOSH Method 7604), respectively. The amount of total fume generated was significantly related to the level of input power. The ranges of FGR were 189-344, 389-698 and 682-1157 mg/min at low, optimal and high input power, respectively. It was found that the FGRs increased with input power by an exponent of 1.19, and increased with current by an exponent of 1.75. The ranges of total chromium fume generation rate (FGRCr) were 3.83-8.27, 12.75-37.25 and 38.79-76.46 mg/min at low, optimal and high input power, respectively. The ranges of hexavalent chromium fume generation rate (FGRCr6+) were 0.46-2.89, 0.76-6.28 and 1.70-11.21 mg/min at low, optimal and high input power, respectively. Thus, hexavalent chromium, which is known to be a carcinogen, generated 1.9 (1.0-2.7) times and 3.7 (2.4-5.0) times as the input power increased from low to optimal and low to high, respectively. As a function of input power, the concentration of total chromium in the fume increased from 1.57-2.65 to 5.45-8.13% while the concentration of hexavalent chromium ranged from 0.15 to 1.08%. The soluble fraction of hexavalent chromium produced by FCAW was approximately 80-90% of total hexavalent chromium. The concentration of total chromium and the solubility of hexavalent chromium were similar to those reported from other studies of shielded metal arc welding fumes, and the concentration of hexavalent chromium was similar to that obtained for metal inert gas-welding fumes.     

Depletion of intracellular zinc and copper with TPEN results in apoptosis of cultured human retinal pigment epithelial cells

PURPOSE: Although zinc deficiency may contribute to the pathogenesis of age-related macular degeneration, how it leads to retinal pigment epithelium (RPE) degeneration is unknown. To investigate this, cultured human RPE cells were rendered zinc depleted with a membrane-permeant metal chelator, N,N,N',N-tetrakis(2-pyridylmethyl) ethylenediamine (TPEN), and the resultant cytopathic changes were examined. METHODS: RPE cell degeneration was examined with light microscopy, TdT-mediated dUTP nick end labeling (TUNEL) staining, Hoechst dye staining, and electron microscopy and quantified with cell counting or lactate dehydrogenase release assay. The effect of sublethal zinc depletion on the vulnerability of RPE cells to UV irradiation or hydrogen peroxide (H(2)O(2)) exposure, was studied in cultures without or with pretreatment with low-concentration TPEN. RESULTS: Exposure to 1 to 4 microM TPEN for 48 hours induced RPE cell death in a concentration-dependent manner. Features of apoptosis such as membrane blebbing, chromatin condensation, nuclear fragmentation, and caspase-3 activation, accompanied the TPEN-induced cell death. Addition of equimolar zinc or copper completely reversed TPEN-induced apoptosis, whereas addition of iron had no effect. As in apoptosis of several other cell types including neurons, a protein synthesis inhibitor as well as caspase inhibitors blocked TPEN-induced apoptosis. On the contrary, at sublethal concentrations, TPEN increased the vulnerability of RPE cells to subsequent UV irradiation but not to H(2)O(2) exposure. CONCLUSIONS: The present results suggest that depletion of intracellular zinc and copper, but not copper alone, may be harmful to RPE cells, directly inducing apoptosis or indirectly increasing vulnerability of RPE cells to UV injury. The present culture model may be useful for gaining insights into the mechanisms of zinc depletion-associated RPE cell degeneration.     

Cellular and humoral adjuvant activity of lectins isolated from Korean mistletoe (Viscum album colaratum)

The adjuvant effect of lectins (KML-C) isolated from Korean mistletoe (Viscum album coloratum) on induction of humoral and cellular immune responses against keyhole limpet hemocyanine (KLH) was examined. When mice were immunized subcutaneously (s.c.) with KLH (20 micrograms/mouse) admixed with or without 50 ng/mouse of KML-C (KLH + KML-C), mice immunized with KLH + KML-C showed significantly higher antibody titers against KLH than those immunized with KLH alone, showing the highest titer 5 weeks after immunization. Furthermore, boost immunization with KLH + KML-C at 2-week interval elicited much higher activity than single immunization to enhance antibody responses against KLH. The assay for determining isotypes of antibodies revealed that KML-C augmented KLH-specific antibody titers of IgG1, IgG2a and IgG2b. The culture supernatants obtained from the splenocytes of mice treated with KLH + KML-C also showed a higher level of both KLH-specific Th-1 (IL-2 and IFN-gamma) and Th-2 type cytokine (IL-4). In an in vitro analysis of T lymphocyte proliferation to KLH on week 4, the splenocytes of mice treated with KLH + KML-C showed a significantly higher proliferating activity than those treated with KLH alone. In addition, mice immunized twice with KLH + KML-C and followed by intrafootpad (i.f.) injection of KLH (50 micrograms/site) 14 weeks after the primary immunization induced a higher delayed-type hypersensitivity (DTH) reaction than mice treated with KLH alone. These results suggest that KML-C is a potent immunoadjuvant to enhance cellular and humoral immune responses.     

Location of the chronic subdural haematoma: role of the gravity and cranial morphology

Chronic subdural haematoma (SDH) frequently originates from subdural hygroma (SDG). The cranial morphology can determine the location of SDG. Since SDG is the precursor of chronic SDH, the shapes of the cranium wall act an important role in location of chronic SDH. The authors tried to test this hypothesis. The computed tomographic scans or magnetic resonance images of 118 consecutive patients with chronic SDH were re-evaluated, and the symmetry of the cranium and location of the lesion were checked. The cranium was symmetrical in 55 patients (47%) and asymmetrical in 63 patients (53%). Chronic SDH was bilateral in 25 patients (21%) and unilateral in 93 patients (79%). It was more commonly bilateral in symmetrical craniums than in asymmetrical craniums (29.1% vs. 14.3%) (p = 0.0496). In 63 patients with asymmetric cranium, the chronic SDH was bilateral in nine patients, located on the opposite side of the flat side in 38 patients, and located on the same side of the flat side in 17 patients. This unequal distribution was statistically significant (p = 0.03). In four patients, the haematoma originated from the acute SDH located on the same side of the flat side. No reason could be found in the remaining 13 patients. Chronic SDH originating from SDG usually locates on the opposite to the flat side of the skull. The shape and posture of the cranium can predict the location of chronic SDH, as in the SDG.