Note: wearable near-infrared spectroscopy imager for haired region.

A wearable optical topography system was developed that is based on near-infrared spectroscopy (NIRS) for observing brain activity noninvasively including in regions covered by hair. An avalanche photo diode, high voltage dc-dc converter, and preamplifier were placed in an electrically shielded case to be safely mounted on the head. Rubber teeth and a glass rod were prepared to clear away hair and reach the scalp. These devices realized for the first time a wearable NIRS imager for any region of the cortex. The activity in the motor cortex during finger tapping was successfully observed.

Whole-heart coronary MR angiography under a single breath-hold: a comparative study with respiratory-gated acquisition using a multi-element phased-array coil.

AIM: To compare visualization using whole-heart coronary magnetic resonance angiography (CMRA) acquired during a single breath-hold (BH) with that using conventional respiratory-gated (RG) CMRA. MATERIALS AND METHODS: The CMRAs of 14 healthy subjects under either BH or RG conditions were studied using a 1.5 T system equipped with a whole-body phased-array coil and 16-channel receivers. The BH examination was accelerated using parallel imaging (PI) by factors of 2.5 and 2 in the phase and section directions, respectively. For the RG examination, a PI factor of 2 was used only in the phase direction. The visualization quality of 15 coronary segments using each condition was evaluated with a five-point scale (0-4). Differences between two conditions were compared at segments with an average score greater than 2 in RG-CMRA. RESULTS: The average examination time for BH and RG acquisition scans was 34 s and 11 min 31 s, respectively. Ten segments (segments 1-3, 5-9, 11, and 13) had average scores higher than 2 in RG-CMRA. Of these, BH-CMRA had significantly lower scores than RG-CMRA at six segments (segments 1, 5-8, and 11) after correction for multiple comparisons (p<0.005). However, in BH-CMRA, proximal segments (segments 1-2, 5-7, and 11) showed average scores over 2, indicating marginally acceptable image quality. CONCLUSION: Compared with the relatively limited degree of image degradation with RG-CMRA, the present data suggest that BH-CMRA would be useful for screening and as an adjunct to RG-CMRA that is occasionally incomplete.

Significance of Tei-index alterations induced by acute preload reduction with hemodialysis.

AIM: The load dependence of Tei-index, an index to estimate combined systolic and diastolic ventricular functions, remains controversial. Moreover, its significance in the setting of acute preload reduction including hemodialysis (HD) remains unknown. Therefore, we examined the significance of the Tei-index in HD patients. PATIENTS AND METHODS: Doppler echocardiographic parameters of 42 patients with normal left ventricular ejection fraction (LVEF) were evaluated before and after HD. Based on the index of body water excess calculated using a Crit-Line monitor, the patients were assigned to Group A (normal hydration approximately overhydration) and Group B (risk of pulmonary congestion). RESULTS: Group A was younger and had a shorter isovolumic relaxation time (IRT) than Group B before HD. Hemodialysis significantly increased the Tei-index of Group A, which was derived from prolonging IRT and isovolumic contraction time and shortening the ejection time without changing LVEF. Changes in the Tei-index (DeltaTei-index) significantly correlated with the rate at which blood volume decreased. They were derived from graphs generated using the Crit-Line monitor. Furthermore, the DeltaTei-index inversely correlated with the Tei-index before HD. CONCLUSION: These findings suggest that the Tei-index is preload-dependent, which is related to changes in volume and speed. Thus, the Tei-index should be cautiously interpreted according to various hemodynamic situations. However, the correlation between the DeltaTei-index and the Tei-index before HD implies that the latter could be a good indicator of effective fluid removal by HD.

Persistence of viral RNA segments in the central nervous system of mice after recovery from acute influenza A virus infection.

One-hundred thirty-seven BALB/c mice were intranasally inoculated with neurotropic avian influenza A virus (H5N3). Thirty-nine of these mice died within 16 days post-inoculation (PID) and 98 of the mice recovered from the infection. To investigate whether viral antigens and genomes persist in the central nervous system (CNS) of recovered mice, immunohistochemistry and reverse transcription-polymerase chain reaction (RT-PCR) methods were performed. Histopathologically, mild interstitial pneumonia and non-suppurative encephalomyelitis restricted to the basal part of the frontal lobe of the cerebrum, brain stem and thoracic spinal cord were observed in BALB/c mice until 40 PID. Small amounts of viral antigens were detected in the brain and spinal cord and some viral RNA segments (NA, NP, M, PA, HA, NS, PB1) were intermittently detected in the CNS until 48 PID. Immunosuppression of these mice by dexamethazone (DEX) treatment did not increase the frequency of detection of the lesions, viral antigens or genomes. These findings suggest that viral genomes of neurovirulent influenza virus persist with restricted transcriptive activity in the CNS of the mice even after clinical recovery from the infection.

Contrast enhancement of the cochlear aqueduct in MR imaging: its frequency and clinical significance.

There have been no previous reports on contrast enhancement of the cochlear aqueduct in magnetic resonance imaging. The purpose of the present study was to evaluate the frequency and significance of this finding. Thirty-one patients (15 men and 16 women; age range 18-81 years) with otologic symptoms (sudden sensorineural hearing loss, vertigo, or tinnitus) were examined using contrast-enhanced imaging on a 1.5-T MR scanner. The normal ear served as the control. Two radiologists evaluated contrast enhancement in the area of the cochlear aqueduct. Forty-eight of 62 ears (77.4%) showed contrast enhancement of the cochlear aqueduct, but no significant differences in the frequency of contrast enhancement were observed between patients with and patients without vertigo, tinnitus, sensorineural hearing loss, cerebellopontine angle tumors, or a high-riding jugular bulb. In addition, no gender- or age-related differences were noted. Contrast enhancement of the cochlear aqueduct was frequently observed, but the frequency of enhancement in symptomatic ears was not significantly higher than in control ears. The results of this study may prove helpful in avoiding unnecessary examinations and potential diagnostic confusion.

Successful removal of a left main coronary artery thrombus induced by vasospasm to the aorta [correction of vasospasm of the aorta] after the injection of contrast medium.

A 51-year-old woman with acute myocardial infarction underwent emergency coronary angiography. The patient had an episode of idiopathic thrombocytopenic purpura, and underwent splenectomy at the age of 36. On admission, platelet count in the peripheral blood was 43.2x10(4)/microl. During the initial emergency left coronary angiography, a thrombus was detected in the left main trunk. The thrombus was drawn back to the orifice of the left coronary artery, and finally disappeared into the aorta by injecting contrast media. After the thrombus disappeared, no stenotic lesion was detected in the left coronary artery. One month later, when acetylcholine-provocation coronary angiography was performed, marked vasospasm was detected in the left coronary arteries. Coronary thrombosis in the patient might have been induced by a coronary spasm, and the presence of thrombocytosis might also have affected the development of a coronary thrombus. However, it was spontaneously drawn back to the aorta by back flow of contrast media, which was injected via the entrance of the left coronary artery. A case of acute myocardial infarction whose thrombus occluded the left main coronary artery and was removed at first injection of contrast media is presented.

Virtual endoscopy of the labyrinth, using a 3D-FastASE sequence.

Virtual endoscopy (VE) of the labyrinth was performed using three-dimensional (3D)-fast asymmetric spin-echo MR imaging. The spatial resolution requirements and the usefulness of zero-fill interpolation (ZIP) were evaluated, and VE was used to examine three patients. The (0.6-mm) voxel data with ZIP satisfies the minimum requirements for VE for evaluation of the complex 3D anatomy and pathology of the labyrinth. J. Magn. Reson. Imaging 2001;13:792-796.

Abnormalities of synapses and neurons in the hippocampus of neuropsin-deficient mice.

In the present study, we produced null-mutant mice of neuropsin, an extracellular matrix serine protease, to examine the neural functions of this protein particularly in the hippocampus. Golgi-Cox impregnation and Nissl-staining revealed morphological change of cell soma in the mutant mice compared to wild-type mice. However, Golgi-Cox impregnation revealed no apparent change in the dendritic arborization and spine density. Quantitative electronmicroscopic analysis revealed that number of asymmetrical synapses were significantly decreased in the stratum radiatum, the major terminal field of Schaffer-collaterals, whereas free boutons still holding synaptic vesicles but with no synaptic specialization were increased in number in the same microscopic fields. An increased number of parvalbumin-immunoreactive cells (known as fast spiking cells) in mutant was also observed. These results strongly suggest that neuropsin is involved in connectivity of a group of CA1 synapses and consequently in the hippocampal networking.

Precursor genes of future pandemic influenza viruses are perpetuated in ducks nesting in Siberia.

Influenza A viruses of different subtypes were isolated from fecal samples of ducks in their nesting areas in Siberia in summer from 1996 to 1998. Phylogenetic analysis of the NP genes of the isolates in Siberia and those in Hokkaido, Japan on their flyway of migration from Siberia to the south in autumn revealed that they belong to the Eurasian lineage of avian influenza viruses. It is noted that the genes of the isolates in Siberia are closely related to those of H5N1 influenza virus strains isolated from chickens and humans in Hong Kong in 1997 as well as to those of isolates from domestic birds in southern China. The results indicate that influenza viruses perpetuated in ducks nesting in Siberia should have contributed genes in the emergence of the H5N1 virus in Hong Kong. Vaccine prepared from avirulent A/duck/Hokkaido/4/96 (H5N3) influenza virus was potent enough to protect mice from challenge with lethal dose of the pathogenic H5N1 virus [19]. Intensive surveillance study of aquatic birds especially in Siberia is, therefore, stressed to provide information on the future pandemic influenza virus strains and for vaccine preparation.

Avirulent Avian influenza virus as a vaccine strain against a potential human pandemic.

In the influenza H5N1 virus incident in Hong Kong in 1997, viruses that are closely related to H5N1 viruses initially isolated in a severe outbreak of avian influenza in chickens were isolated from humans, signaling the possibility of an incipient pandemic. However, it was not possible to prepare a vaccine against the virus in the conventional embryonated egg system because of the lethality of the virus for chicken embryos and the high level of biosafety therefore required for vaccine production. Alternative approaches, including an avirulent H5N4 virus isolated from a migratory duck as a surrogate virus, H5N1 virus as a reassortant with avian virus H3N1 and an avirulent recombinant H5N1 virus generated by reverse genetics, have been explored. All vaccines were formalin inactivated. Intraperitoneal immunization of mice with each of vaccines elicited the production of hemagglutination-inhibiting and virus-neutralizing antibodies, while intranasal vaccination without adjuvant induced both mucosal and systemic antibody responses that protected the mice from lethal H5N1 virus challenge. Surveillance of birds and animals, particularly aquatic birds, for viruses to provide vaccine strains, especially surrogate viruses, for a future pandemic is stressed.

Tyrosine kinase is essential for the constitutive expression of type I interleukin-1 receptor in human fibroblast cells.

The effect of genistein, an inhibitor of tyrosine kinase, on the constitutive expression of type I interleukin-1 receptor (IL-1RI) was examined in the human lung fibroblast cell line TIG-1, which has been shown to express only type I IL-1R. Genistein inhibited the 125I-labeled IL-1alpha binding to TIG-1 cells in both a time and dose dependent manner. Scatchard plot analysis revealed that the number of IL-1RI decreased with no change in binding affinity. Genistein did not affect the level of IL-1RI mRNA, and cycloheximide did not inhibit the down-regulatory effect of genistein. These results indicate that genistein inhibits IL-1RI expression, not at the transcriptional level, but at the post-translational level. IL-1RI expression, IL-1R associated kinase (IRAK) activity and IL-1-induced-IL-6 production were all down-regulated by pretreatment with genistein. These findings indicate that tyrosine kinase activity is essential for the constitutive expression of functional IL-1RI.

Optimization of preparative conditions for polylactide (PLA) microspheres containing ovalbumin.

Polylactide (PLA) microspheres containing ovalbumin (OVA) as a model protein were prepared by a water-in-oil-in-water (w/o/w) emulsion solvent evaporation method. The optimization of preparative parameters for the PLA microspheres containing OVA were performed, and the in vitro characteristics of the obtained microspheres were examined. Firstly, a smaller internal aqueous phase volume was found to be advantageous in obtaining high loading efficiency. Secondly, the addition of 2-10% (w/v) NaCl into the external aqueous phase (0.5% (w/v) polyvinyl alcohol solution) also improved OVA loading efficiency. Prepared products showed a sharp release of OVA at the initial phase, but the following phase was characterized by a slow release rate of OVA that continued at least 28 d. The release rate of OVA from microspheres made of PLA with a molecular weight of 15400 was faster than that from microspheres made of PLA with a molecular weight of 58300. However, the LA/GA (lactide/glycolide) ratio was not likely to have much effect on the release profile of OVA. Finally, the effect of PLA microsphere particle size on the release profiles of OVA was examined. The extent of burst release at the initial phase increased as the mean diameter of prepared PLA microspheres decreased. For example, the PLA microspheres with a small mean diameter (5.0 microns) showed a 40% burst release, but almost 30% of OVA remained in the PLA microspheres (confirmed by HPLC method) after the 28 d release test, suggesting the possibility of using this carrier as a long-acting protein delivery system.

Unbalanced 1;7 translocation in myelodysplastic syndrome following treatment of acute myeloblastic leukemia with an 8;21 translocation.

The chromosome der(1;7)(q10;p10) consists of the short arm of chromosome 7 and the long arm of chromosome 1, and is a common abnormality in treatment-related leukemia and myelodysplastic syndrome. Here we describe a 39-year-old Japanese man with acute myeloblastic leukemia (FAB-M2) exhibiting t(8;21)(q22;q22). He entered complete remission after induction therapy, and intensification therapy including alkylating agents was subsequently continued for 3 years. The patient then developed pancytopenia; bone marrow aspiration revealed myelodysplastic syndrome exhibiting the der (1;7) chromosome. To our knowledge, this is the first reported case of such an abnormality in myelodysplastic syndrome secondary to acute myeloblastic leukemia with the 8;21 translocation.