Acute myocardial infarction in a patient with anomalous left coronary artery origin and primary antiphospholipid syndrome

Anomalous left main coronary artery (LMCA) originating from the right coronary sinus and running between the aorta and pulmonary trunk is a rare congenital condition. Although this disease is known to be associated with myocardial infarction and sudden death, the precise mechanism is uncertain. A 14-year-old male with this anomaly developed myocardial infarction during exercise complicated by primary antiphospholipid syndrome. He was admitted to hospital with persistent chest pain and sudden cardiac collapse that occurred while he was running. Cardiac catheterization demonstrated a narrowed segment in the LMCA and impaired blood flow, prompting a diagnosis of extensive anterior myocardial infarction. Emergency bypass surgery was performed using a single saphenous vein graft to the left anterior descending artery. Postoperative angiography showed the presence of an anomalous LMCA arising from the right sinus of Valsalva and running between the great vessels. The aortic samples were pathologically normal. He was discovered to also have primary antiphospholipid syndrome and was discharged without symptoms after warfarin therapy. Complicated primary antiphospholipid syndrome may trigger myocardial infarction in asymptomatic patients with this type of coronary anomaly.

Structural comparison of the PhoB and OmpR DNA-binding/transactivation domains and the arrangement of PhoB molecules on the phosphate box

PhoB is a transcriptional activator that binds to the phosphate box in the promoters of the phosphate genes of Escherichia coli. PhoB contains two functional domains, an N-terminal phosphorylation domain and a C-terminal DNA-binding/transactivation domain. Here, the three-dimensional structure of the DNA-binding/transactivation domain has been determined by NMR. It consists of an N-terminal four-stranded beta-sheet, a central three helical bundle and a C-terminal beta-hairpin. The second and third helices form a helix-turn-helix (HTH) variant containing a longer turn than the corresponding turn of the classical HTH motif. The overall architecture is very close to that of the OmpR DNA-binding/transactivation domain, however, the conformation of the long turn region of PhoB, a putative interaction site for the RNA polymerase sigma subunit, is entirely different from that of the corresponding turn of OmpR, which interacts with the alpha subunit. In addition, the third helix of PhoB is three amino acid residues longer than the corresponding helix of OmpR. The binding site of PhoB is a TGTCA sequence and the phospahte box contains the two binding sites. NMR studies of the complexes of the PhoB DNA-binding/transactivation domain bound to several different DNA molecules have revealed that two PhoB molecules bind in a tandem array on the phosphate box. In each complex of PhoB the third helix of the DNA-binding/transactivation domain is likely to recognize the TGTCA sequence from the major groove of DNA and the C-terminal beta-hairpin contacts on the minor groove of the 3' site out of the TGTCA sequence in a non-specific manner. The long turn region facing outward is likely to interact with the sigma subunit.

Formation of 2'-deoxyoxanosine from 2'-deoxyguanosine and nitrous acid: mechanism and intermediates

The reaction mechanism for the formation of 2'-deoxy-oxanosine from 2'-deoxyguanosine by nitrous acid was explored using methyl derivatives of guanosine and an isolated intermediate of the reaction. When 1-methylguanosine was incubated with NaNO(2)under acidic conditions, N (5) -methyloxanosine and 1-methylxanthosine were generated, whereas the same treatment of N (2), N (2)-dimethylguanosine generated no product. In a similar experiment without NO(2)(-), participation of a Dimroth rearrangement was ruled out. In the guanosine-HNO(2)reaction system, an intermediate with a half-life of 5.6 min (pH 7.0, 20 degrees C) was isolated and tentatively identified as a diazoate derivative of guanosine. The diazoate intermediate was converted into oxanosine and xanthosine at a molar ratio (oxanosine:xanthosine) of 0.26 at pH 7.0 and 20 degrees C. The ratio was not affected by the incubation pH between 2 and 10, but increased linearly with temperature from 0.22 (0 degrees C) to 0.32 (50 degrees C). The addition of acetone also increased the ratio up to 0.85 (98% acetone). Based on these results, a con-ceivable pathway for the formation of 2'-deoxyoxanosine from 2'-deoxyguanosine by HNO(2)is proposed.

INE: a rice genome database with an integrated map view

The Rice Genome Research Program (RGP) launched a large-scale rice genome sequencing in 1998 aimed at decoding all genetic information in rice. A new genome database called INE (INtegrated rice genome Explorer) has been developed in order to integrate all the genomic information that has been accumulated so far and to correlate these data with the genome sequence. A web interface based on Java applet provides a rapid viewing capability in the database. The first operational version of the database has been completed which includes a genetic map, a physical map using YAC (Yeast Artificial Chromosome) clones and PAC (P1-derived Artificial Chromosome) contigs. These maps are displayed graphically so that the positional relationships among the mapped markers on each chromosome can be easily resolved. INE incorporates the sequences and annotations of the PAC contig. A site on low quality information ensures that all submitted sequence data comply with the standard for accuracy. As a repository of rice genome sequence, INE will also serve as a common database of all sequence data obtained by collaborating members of the International Rice Genome Sequencing Project (IRGSP). The database can be accessed at http://www. dna.affrc.go.jp:82/giot/INE. html or its mirror site at http://www.staff.or.jp/giot/INE.html

Chromosome of the enterohemorrhagic Escherichia coli O157:H7; comparative analysis with K-12 MG1655 revealed the acquisition of a large amount of foreign DNAs

A complete Xba I and Bln I cleavage map was constructed for the chromosome of an enterohemorrhagic Escherichia coli (EHEC) O157:H7 strain isolated from an outbreak in Sakai City, Japan, in 1996. A comparative chromosome analysis with E. coli K-12 strain MG1655 was made. The EHEC chromosome was approximately 5600 kb in length, 1 Mb larger than that of MG1655. Despite the marked difference in chromosome length, the location and direction of seven rRNA operons of the EHEC strain were similar to those for MG1655. Overall organization of genes common in both strains is also highly conserved. Chromosome expansion was observed throughout the EHEC chromosome, albeit in an uneven manner. A large portion of the chromosome enlargement was observed in the region surrounding the replication terminus, particularly in a segment containing the terA locus. Sample sequencing of 3627 random shotgun clones suggested the presence of approximately 1550 kb strain-specific DNAs on the EHEC chromosome, most of which are likely to be of foreign origin.

Structure and stability of the consecutive stereoregulated chiral phosphorothioate DNA duplex

The duplex structures of the stereoregulated phosphorothioate DNAs, [R(p),R(p)]- and [S(p),S(p)]-[d(GC(ps)T(ps)ACG)] (ps, phosphorothioate; PS-DNA), with their complementary RNA have been investigated by combined use of (1)H NMR and restrained molecular dynamics calculation. Compared to those obtained for the unmodified duplex structures (PO-DNA.RNA), the NOE cross-peak intensities are virtually identical for the PS-DNA.RNA hybrid duplexes. The structural analysis on the basis of the NOE restraints reveals that all of the three DNA.RNA duplexes take a A-form conformation and that there is no significant difference in the base stacking for the DNA.RNA hybrid duplexes. On the other hand, the NOE cross-peak intensities of the protons around the central T(ps)A step of the PS-DNA.DNA duplexes are apparently different from those of PO-DNA. DNA. The chemical shifts of H8/6 and H1' at the T(ps)A step are also largely different among PS-DNA.DNAs and PO-DNA.DNA, suggesting that the DNA.DNA structure is readily changed by the introduction of the phosphorothioate groups to the central T(p)A step. The structure calculations indicate that all of these DNA.DNA duplexes are B-form although there exist some small differences in helical parameters between the [R(p),R(p)]- and [S(p),S(p)]PS-DNA.DNA duplexes. The melting temperatures (T(m)) were determined for all of the duplexes by plotting the chemical shift change of isolated peaks as a function of temperature. For the PS-DNA.RNA hybrid duplexes, the [S(p),S(p)] isomer is less stable than the [R(p),R(p)] isomer while this trend is reversed for the PS-DNA.DNA duplexes. Consequently, although the PS-DNA.RNA duplexes take the similar A-form structure, the duplex stability is different between PS-DNA.RNA duplexes. The stability of the DNA.RNA duplexes may not be governed by the A-form structure itself but by some other factors such as the hydration around the phosphorothioate backbone, although the T(m) difference of the DNA.DNA duplexes could be explained by the structural factor.

A novel NE-dlg/SAP102-associated protein, p51-nedasin, related to the amidohydrolase superfamily, interferes with the association between NE-dlg/SAP102 and N-methyl-D-aspartate receptor

The membrane-associated guanylate kinase proteins have been known to interact various membrane receptors with their N-terminal segments designated the PDZ domains and to cluster these receptors at the target site of the cell membrane. NE-dlg/SAP102, a neuronal and endocrine tissue-specific MAGUK family protein, was found to be expressed in both dendrites and cell bodies in neuronal cells. Although NE-dlg/SAP102 localized at dendrites was shown to interact with N-methyl-D-aspartate receptor 2B via the PDZ domains to compose postsynaptic density, the binding proteins existing in the cell body of the neuron are still unknown. Here we report the isolation of a novel NE-dlg/SAP102-associated protein, p51-nedasin. Nedasin has a significant homology with amidohydrolase superfamily proteins and shows identical sequences to a recently identified protein that has guanine aminohydrolase activity. Nedasin has four alternative splice variants (S, V1, V2, and V3) that exhibited different C-terminal structures. NE-dlg/SAP102 is shown to interact with only the S form of nedasin which is predominantly expressed in brain. The expression of nedasin in neuronal cells increases in parallel with the progress of synaptogenesis and is mainly detected in cell bodies where it co-localizes with NE-dlg/SAP102. Furthermore, nedasin interferes with the association between NE-dlg/SAP102 and NMDA receptor 2B in vitro. These findings suggest that alternative splicing of nedasin may play a role in the formation and/or structural change in synapses during neuronal development by modifying clustering of neurotransmitter receptors at the synaptic sites.

A human homolog of Drosophila warts tumor suppressor, h-warts, localized to mitotic apparatus and specifically phosphorylated during mitosis

We identified a human homolog of Drosophila warts tumor suppressor gene, termed h-warts, which was mapped at chromosome 6q24-25.1. The h-warts protein has a serine/threonine kinase domain and is localized to centrosomes in interphase cells. However, it becomes localized to the mitotic apparatus, including spindle pole bodies, mitotic spindle, and midbody, in a highly dynamic manner during mitosis. Furthermore, h-warts is specifically phosphorylated in cells at mitotic phase, most likely by Cdc2 kinase. These findings suggest that h-warts functions as a component of the mitotic apparatus and is involved in proper progression of mitosis.

[A simple method for regional cerebral blood flow measurement by one-point arterial blood sampling and 123I-IMP microsphere model (Part 2): A study of time correction of one-point blood sample count]

In our previous paper regarding determination of the regional cerebral blood flow (rCBF) using the 123I-IMP microsphere model, we reported that the accuracy of determination of the integrated value of the input function from one-point arterial blood sampling can be increased by performing correction using the 5 min: 29 min ratio for the whole-brain count. However, failure to carry out the arterial blood collection at exactly 5 minutes after 123I-IMP injection causes errors with this method, and there is thus a time limitation. We have now revised our method so that the one-point arterial blood sampling can be performed at any time during the interval between 5 minutes and 20 minutes after 123I-IMP injection, with addition of a correction step for the sampling time. This revised method permits more accurate estimation of the integral of the input functions. This method was then applied to 174 experimental subjects: one-point blood samples collected at random times between 5 and 20 minutes, and the estimated values for the continuous arterial octanol extraction count (COC) were determined. The mean error rate between the COC and the actual measured continuous arterial octanol extraction count (OC) was 3.6%, and the standard deviation was 12.7%. Accordingly, in 70% of the cases, the rCBF was able to be estimated within an error rate of 13%, while estimation was possible in 95% of the cases within an error rate of 25%. This improved method is a simple technique for determination of the rCBF by 123I-IMP microsphere model and one-point arterial blood sampling which no longer shows a time limitation and does not require any octanol extraction step.

Complete nucleotide sequence of the prophage VT2-Sakai carrying the verotoxin 2 genes of the enterohemorrhagic Escherichia coli O157:H7 derived from the Sakai outbreak

The enterohemorrhagic Escherichia coli (EHEC) O157:H7 strain RIMD 0509952, derived from an outbreak in Sakai city, Japan, in 1996, produces two kinds of verotoxins, VT1 and VT2, encoded by the stx1 and stx2 genes. In the EHEC strains, as well as in other VT-producing E. coli strains, the toxins are encoded by lysogenic bacteriophages. The EHEC O157:H7 strain RIMD 0509952 did not produce plaque-forming phage particles upon inducing treatments. We have determined the complete nucleotide sequence of a prophage, VT2-Sakai, carrying the stx2A and stx2B genes on the chromosome, and presumed the putative functions of the encoded proteins and the cis-acting DNA elements based on sequence homology data. To our surprise, the sequences in the regions of VT2-Sakai corresponding to the early gene regulators and replication proteins, and the DNA sequences recognized by the regulators share very limited homology to those of the VT2-encoding 933W phage carried by the EHEC O157:H7 strain EDL933 reported by Plunkett et al. (J. Bacteriol., p1767-1778, 181, 1999), although the sequences corresponding to the structural components are almost identical. These data suggest that these two phages were derived from a common ancestral phage and that either or both of them underwent multiple genetic rearrangements. An IS629 insertion was found downstream of the stx2B gene and upstream of the lysis gene S, and this might be responsible for the absence of plaque-forming activity in the lysate obtained after inducing treatments.

Two-Layer Structure of Microcapsule Membrane as Predicted from Electrophoretic Studies

Four types of hydrophilic gel microcapsules containing water have been prepared by an interfacial polymerization method. Each type of microcapsules has membranes of different compositions. Using three kinds of monomers, N,N-dimethylacrylamide (DMAAm), 4-aminomethylstyrene (AmSt), and N,N-dimethylaminopropylacrylamide (DMAPAA), two types of water-soluble copolymers with different compositions having primary and tertiary amino groups were obtained. Two more types of copolymers were synthesized by copolymerization of alpha-acryloxy-omega-methoxy-poly(ethylene glycol) (a-PEG) with the above two kinds of monomer mixtures. These copolymers were polymerized with terephthaloyldichloride at the water/oil interface to prepare four types of microcapsules containing water. By electrophoretic mobility measurements of these microcapsules and the analyses of the data, it was found that the surface layer of the microcapsule membranes were composed of two sublayers, each of which has different charge density and softness. The outer sublayer was negatively charged and inner sublayer was positively charged. By PEGylation, the charge density in the outer sublayer decreased, while that in the inner sublayer was not affected. Also, the surface layer became softer by PEGylation. The effects of membrane composition upon the swellability of the microcapsule membrane were studied. It was found that the asymmetrical structure of the microcapsule membranes causes the nonuniform distribution of charges and then the swellability of the microcapsule membrane changes depending on the permittivity of the dispersing medium. Copyright 1999 Academic Press.

Evaluation of the in-line filters for the intravenous infusion of amphotericin B fluid

OBJECTIVE

To evaluate the effects of four types of in-line filters on filtration rate, amphotericin B concentration and particulate matter.

METHODS

Filtration rates of amphotericin B fluid through in-line filters under maximum gravity flow were examined. The concentrations of amphotericin B and the particulate matter in the non-filtered and filtered amphotericin B fluid at the flow rate of 500 ml/24 h were measured.

RESULTS

Filtration through a 1.2 microm or 0.2 microm polyethersulphone (PES) filter under maximum gravity flow took less than 40 min. The 0.2 microm positively charged nylon 66 and 0.2 microm nylon 66 filters took 70 and 100 min, respectively, to filter 500 ml of amphotericin B fluid. The 0.2 microm positively charged nylon 66 filter and the 0.2 microm nylon 66 filter, but not the PES filter (1.2 and 0.2 microm), decreased the concentrations of amphotericin B in the filtered fluid by 100% within 1 h and by 66% within 24 h after the start of filtration, respectively. The particulate count in the non-filtered amphotericin B fluid was 27+/-5 particles/ml, exceeding the limit defined by USP XXIII. The 1.2 microm and 0.2 microm PES filters significantly decreased particulate matter by 83 and 97%, respectively, just after filtration.

CONCLUSION

The present results indicate that the 0.2 microm PES filter is optimal for intravenous infusion of amphotericin B fluid to minimize the introduction of particulate matter, microbial contaminants and endotoxin into patients.

[CT findings of non-traumatic colorectal perforation]

We retrospectively analyzed CT scans from 23 patients with non-traumatic colorectal perforation. We compared the sensitivity of CT and plain film radiography in the detection of free gas. Free gas was observed in 7 of the 23 cases (30.4%) on plain film radiography and 16 of the 23 cases (69.6%) on CT. Retroperitoneal abscess was demonstrated in 6 of the 7 patients without free gas on CT. Extraluminal air and abscess covered by the omentum and mesenterium were demonstrated in the remaining one patient. The site of perforation was identified in 19 of the 23 patients (82.6%) on CT. CT was useful for demonstrating retroperitoneal free gas, changes in mesenteric fat, extraluminal feces, and tumors. We conclude that CT is indicated in cases of suspected colorectal perforation.

Kinetic factors determining wheelchair propulsion in marathon racers with paraplegia

OBJECTIVE

To assess the different factors that determine the propulsion of wheelchair in long distance racers with spinal cord injuries.

DESIGN AND METHODS

Nine highly handicapped men who competed at the Oita International Wheelchair Marathon in 1995, participated in this study. Subjects performed steady and exhaustive wheelchair propulsion at their optimal speed on wheelchair rollers in a laboratory setting during a 5-min period. Movements of the trunk and arms were filmed by a video camera then analyzed kinetically using a two-dimensional analysis system. In order to determine the actual pushing time and angle of wheelchair, we measured the duration between hand contact and hand release from handrim.

SETTING

Department of Rehabilitation Medicine University of Occupational and Environmental Health, Japan.

RESULTS

The push time, cycle time, total push time, and angular velocity did not relate with the race time or wheelchair velocity. However, the total push angle correlated significantly (P<0.01) with the race time and wheelchair velocity. Improvement of the pushing angular velocity and pushing duration did not contribute to the race time.

CONCLUSION

The skilful wheelchair propulsion in long distance racing depends on the total push angle. Improvement of the total push angle should be achieved by both prolongation of the total push time and increased pushing angular velocity.

Assessment of outcome by EC/IC bypass with 123I-iomazenil brain SPECT

We report two patients with occlusive cerebrovascular disease who were examined by means of benzodiazepine receptor SPECT(BZR-SPECT) with 123I-iomazenil (IMZ) before extracranial-intracranial bypass surgery (EC/IC bypass). Preoperative low perfusion areas detected by cerebral blood flow SPECT (CBF-SPECT) were divided into two parts on BZR-SPECT images. In the low perfusion areas where the BZR were preserved, regional cerebral blood flow (rCBF) increased on postoperative CBF-SPECT, but where the BZR were not preserved, rCBF did not increase on postoperative CBF-SPECT. On visual inspection, the SPECT images of postoperative CBF-SPECT appeared similar to those of preoperative BZR-SPECT. For evaluation of the ischemic brain condition itself, instead of the cerebral metabolism, the distribution and activity of cerebral neurons indicated by BZR-SPECT with IMZ might be utilized.

[Ruptured persistent primitive hypoglossal artery aneurysm: case report]

Persistent primitive hypoglossal artery is less common than persistent primitive trigeminal artery. About one hundred examples of such hypoglossal arteries have been demonstrated by angiography. The origin of persistent primitive hypoglossal artery is the cervical segment of the internal carotid artery, usually at the level of the first to second cervical vertebrae. The artery then enters, with varying degrees of tortuosity, the anterior condyloid (hypoglossal) canal and joints the basilar artery immediately above its lower end. When enlargement of this canal is identified, the presence of a persistent primitive hypoglossal artery should be strongly suspected. The homolateral vertebral artery is frequently hypoplasia. A 66-year-old man was brought to our hospital due to faintness. CT showed thick subarachnoid hemorrhage. Angiography showed that a persistent primitive hypoglossal artery aneurysm was present, but the posterior communicating artery was absent. Right vertebral angiography showed extravasation due to re-rupture of the aneurysm. An operation was performed at day 0 using the left transcondylar approach despite deterioration of SAH grading. Intraoperative re-rupturing occurred and the lower cranial nerves clustered around the aneurysm, so the aneurysm was partially clipped on the dome. The second angiography was carried out at day 10, and there was no vasospasm. Palsy of the lower cranial nerves appeared transiently. A ventricle-peritoneum shunt was required due to normal pressure hydrocephalus, but the patient was discharged with no neurological deficits.

Isolation and characterization of diazoate intermediate upon nitrous acid and nitric oxide treatment of 2'-deoxycytidine

The intermediate produced from dCyd by HNO2 and NO treatments was isolated and characterized. When 10 mM dCyd was treated with 100 mM NaNO2 in 1.0 M acetate buffer (pH 3.7) at 37 degrees C, a previously unidentified product was formed. By spectrometric measurements, the product was identified as a diazoate derivative of dCyd, 1-(beta-D-2'-deoxyribofuranosyl)-2-oxopyrimidine-4-diazoate. The time course of the concentration change of the diazoate showed a profile characteristic of a reaction intermediate, and the maximum yield was 37 microM at the reaction time of 25 min. Up to the reaction time of 10 min, the diazoate concentration was greater than that of dUrd, a deamination product of dCyd. Addition of thiocyanate increased the yield of the diazoate in HNO2 treatment, whereas addition of ascorbate decreased the yield. When 10 mM dCyd in 100 mM phosphate buffer was treated with NO at 37 degrees C under aerobic conditions holding the pH (7.2-7.6), the diazoate was also generated. The yield of the diazoate was higher than that of dUrd up to 15 mmol of NO absorption. At pH 3.7 and 37 degrees C, the diazoate was converted to dUrd with the first-order rate constant k = 4.8 x 10(-)4 s-1 (t1/2 = 24 min). Under physiological conditions (pH 7.4, 37 degrees C), however, it was fairly stable (k = 5.8 x 10(-)7 s-1, t1/2 = 330 h). In both cases, the diazoate was converted to dUrd exclusively and no other intermediates were detected by HPLC analysis. Uracil-DNA glycosylase did not remove the diazoate residue from an oligodeoxynucleotide containing this damage, [d(T6DT5), D = the diazoate]. The Tm value of a duplex containing the diazoate, d(T6DT5).d(A5GA6), was much lower than that of a duplex containing a correct C:G base pair, d(T6CT5).d(A5GA6). These results show that the diazoate is generated as a stable intermediate in the reactions of dCyd with HNO2 and NO and that the major product is the diazoate but not dUrd in the initial stage of the reactions. Thus, once formed in vivo, the diazoate persists for long time in DNA and may act as a major cytotoxic and/or genotoxic lesion with biologically relevant doses of HNO2 and NO.

Stability of the dimerization domain effects the cooperative DNA binding of short peptides

The basic region peptide derived from the basic leucine zipper protein GCN4 bound specifically to the native GCN4 binding sequences in a dimeric form when the beta-cyclodextrin/adamantane dimerization domain was introduced at the C-terminus of the GCN4 basic region peptide. We describe here how the structure and stability of the dimerization domain affect the cooperative formation of the peptide dimer-DNA complex. The basic region peptides with five different guest molecules were synthesized, and their equilibrium dissociation constants with a peptide possessing beta-cyclodextrin were determined. These values, ranging from 1.3 to 15 microM, were used to estimate the stability of the complexes between the dimers with various guest/cyclodextrin dimerization domains and GCN4 target sequences. An efficient cooperative formation of the dimer complexes at the GCN4 binding sequence was observed when the adamantyl group was replaced with the norbornyl or noradamantyl group, but not with the cyclohexyl group that formed a beta-cyclodextrin complex with a stability that was 1 order of magnitude lower than that of the adamantyl group. Thus, cooperative formation of the stable dimer-DNA complex appeared to be effected by the stability of the dimerization domain. For the peptides that cooperatively formed dimer-DNA complexes, there was no linear correlation between the stability of the inclusion complex and that of the dimer-DNA complex. With the beta-cyclodextrin/adamantane dimerization domain, the basic region peptide dimer preferred to bind to a palindromic 5'-ATGACGTCAT-3' sequence over the sequence lacking the central G.C base pair and that with an additional G.C base pair in the middle. Changing the adamantyl group into a norbornyl group did not alter the preferential binding of the peptide dimers to the palindromic sequence, but slightly affected the selectivity of the dimer for other nonpalindromic sequences. The helical contents of the peptides in the DNA-bound dimer with the adamantyl group were decreased by reducing the stability of the dimer-DNA complex, which was possibly caused by deformation of the helical structure proximal to the dimerization domain.

Severe stenosis of the internal carotid artery presenting as loss of consciousness due to the presence of a primitive hypoglossal artery: a case report

BACKGROUND

Symptoms of ischemic attacks in the internal carotid system usually involve focal cerebral dysfunction, i.e., hemiparesis or aphasia. However, an ischemic attack in the vertebrobasilar artery system usually presents with combined symptoms. The variety of manifestations included in the vertebrobasilar profile makes the potential pattern of symptoms considerably more variable and complex than that in the carotid system. Manifestations can include syncope and also vertigo.

METHOD AND RESULTS

A 42-year-old woman experienced frequent attacks of faintness with vertigo. Angiography demonstrated severe stenosis of the left internal carotid artery with a persistent primitive hypoglossal artery just distal to the stenosis. The right internal carotid artery was normal and cross circulation through the anterior communicating artery was not well developed. Both vertebral arteries were hypoplastic. The patient underwent carotid endarterectomy and, thereafter the episodes of syncope completely disappeared.

CONCLUSION

It was supposed that global ischemia including the brain stem occurred because of stenosis of the left internal carotid artery attributable to the presence of a primitive hypoglossal artery.

Isokinetic strength of elbow extensor muscles correlates with race time in wheelchair half marathon racers

It has been reported that grasping power and isometric muscle strength of elbow extensors in fine wheelchair racers were greater than the poor racers in the wheelchair full marathon. The purpose of the present study was to investigate the relationship between muscle strength of elbow extensors and flexors and the race time in wheelchair half marathon race. Four wheelchair half marathon racers who completed the half marathon division of the 16th Oita International Wheelchair Marathon (OIWM) in 1996 participated in the present study. The day before the race, all subjects reported to the training room and the isokinetic muscle strength of elbow extensor and flexor muscle groups was measured at angular speeds of 60 degrees, 120 degrees and 240 degrees/sec using the isokinetic dynamometer. There was a significant correlation between race time and isokinetic muscle strength of the elbow extensors at 60 degrees, 120 degrees and 240 degrees/sec, but not flexor muscles. Our findings suggest that increased muscle strength of elbow extensors may improve the race time in wheelchair half marathon race.

Interaction of NE-dlg/SAP102, a neuronal and endocrine tissue-specific membrane-associated guanylate kinase protein, with calmodulin and PSD-95/SAP90. A possible regulatory role in molecular clustering at synaptic sites

NE-dlg/SAP102, a neuronal and endocrine tissue-specific membrane-associated guanylate kinase family protein, is known to bind to C-terminal ends of N-methyl-D-aspartate receptor 2B (NR2B) through its PDZ (PSD-95/Dlg/ZO-1) domains. NE-dlg/SAP102 and NR2B colocalize at synaptic sites in cultured rat hippocampal neurons, and their expressions increase in parallel with the onset of synaptogenesis. We have identified that NE-dlg/SAP102 interacts with calmodulin in a Ca2+-dependent manner. The binding site for calmodulin has been determined to lie at the putative basic alpha-helix region located around the src homology 3 (SH3) domain of NE-dlg/SAP102. Using a surface plasmon resonance measurement system, we detected specific binding of recombinant NE-dlg/SAP102 to the immobilized calmodulin with a Kd value of 44 nM. However, the binding of Ca2+/calmodulin to NE-dlg/SAP102 did not modulate the interaction between PDZ domains of NE-dlg/SAP102 and the C-terminal end of rat NR2B. We have also identified that the region near the calmodulin binding site of NE-dlg/SAP102 interacts with the GUK-like domain of PSD-95/SAP90 by two-hybrid screening. Pull down assay revealed that NE-dlg/SAP102 can interact with PSD-95/SAP90 in the presence of both Ca2+ and calmodulin. These findings suggest that the Ca2+/calmodulin modulates interaction of neuronal membrane-associated guanylate kinase proteins and regulates clustering of neurotransmitter receptors at central synapses.

Improved method of determining thiamylal enantiomers in human serum by high-performance liquid chromatography

Thiamylal, a widely used anesthetic drug, has two enantiomers. We developed a simple and rapid method for measuring the thiamylal enantiomers in human serum. The method involves a liquid-liquid extraction procedure followed by chiral resolution using a 5 microm silica-bonded alpha1-acid glycoprotein column (Chiral-AGP). The thiamylal enantiomers and internal standard were eluted within 15 min and were well-resolved. At concentrations of 1, 5 and 20 microg ml(-1), the relative standard deviations of R(+)- and S(-)-thiamylal were 1.35-2.88% and 1.37-3.01%, respectively, for the intra-day assay, and 2.93-4.46% and 2.46-4.84%, respectively, for the inter-day assay. This method facilitates the routine monitoring and pharmacokinetic studies of thiamylal enantiomers.