Three-dimensional imaging of laryngeal cancers using high-speed helical CT scanning

To evaluate the clinical usefulness and limitations of three-dimensional (3-D) imaging of laryngeal cancers by high-speed helical (spiral) CT scanning, 3-D images were reconstructed for one dissected human larynx and 10 patients with laryngeal cancer. The larynges were scanned in 1- to 2-mm slices, and were reconstructed using a slice thickness of 0.5-1.0 mm. The macroscopic (or endoscopic) findings and the 3-D CT images of the larynx were compared. The selected threshold CT values were -600 HU (Hounsfield units) to -100 HU for the mucous membranes, and 250 HU for bone. Under these conditions, almost all of the structures remained distinct. The 3-D images of the larynx obtained by helical CT were very helpful in understanding laryngeal anatomy, especially in the subglottic area, which cannot be seen clearly by endoscopy or conventional axial CT. Clinically, this system would have advantages in the detection of subglottic cancers, or the invasion of glottic or supraglottic cancers into the subglottic area.

Magnetic resonance signal intensity and volume changes after endovascular treatment of intracranial aneurysms causing mass effect

To determine when and how intracranial aneurysms causing mass effect change following endovascular treatment, we used MRI to assess patients for 2-3 years after the interventional procedure. Nine patients who had aneurysms compressing the surrounding structures underwent endovascular treatment. Proximal occlusion of the parent artery was performed in seven cases, and in two the aneurysm was embolised with microcoils. After embolisation, signal intensity within aneurysms tended to be high on both T1- and T2-weighted images. When there was rapid reduction in size high-signal zones within aneurysms became isointense or gave low signal on T1-weighted images. On T2-weighted images, isointense or low-signal foci appeared within high-signal areas in the aneurysm, giving mixed intensity. In typical cases, the mean volume of the aneurysm fell to approximately 30% of its initial value 2-12 months after treatment. After this, no additional reduction was observed. The aneurysms which showed little signal intensity change tended to shrink more slowly and to a lesser degree than the more typical cases. Aneurysms which gave high signal on both T1- and T2-weighted images early following embolisation shrank more quickly than those showing little signal change.

Isolation of full-length cDNA of mouse PAX4 gene and identification of its human homologue

Recent genetic studies have suggested that PAX4, a member of the paired box (PAX) gene family, is involved in the mechanism regulating the fate of pancreatic islet endocrine progenitor cells. Murine PAX4 was originally identified by genomic screening and, to date, only a partial sequence of PAX4 has been reported. In this study, we cloned the full-length cDNA of mouse PAX4 by RACE (rapid amplification of cDNA ends) using RNA from MIN6 cells, a mouse insulinoma cell line. The full length of cDNA was 1.38 kb, consistent with the estimated size of the transcript by Northern blot. The deduced mouse PAX4 protein was 349 amino acids and had the predicted molecular weight of 38 kDa. Two DNA binding motifs, a 128-amino acid paired domain and a 61-amino acid paired-type homeodomain exhibit the highest amino acid homology with PAX6 (71.2%, 65.0%, respectively), another member of the PAX gene family. However, the sequence of the C-terminal segment of PAX4 diverged and showed no significant homology with any other known PAX genes. As to the genomic DNA, the coding region of the mouse PAX4 gene spanned approximately 5.5 kb and was composed of 10 exons. In the public DNA database, a human cosmid (g1572c264), which was localized on human chromosome 7q31.3, was found to contain a gene homologous to PAX4. The nucleotide and protein sequence homologies between mouse PAX4 and its human homologue were 83.1% and 80.0%, respectively. Interestingly, the ARP5 (ADP-ribosylation factor 5) gene was also found in the same cosmid g1572c264, suggesting the ARP5 gene to be adjacent to the human PAX4 homologue. The human cosmid g1572c264 contains at least four SSRPs (simple sequence repeat polymorphism), which could be used for genetic linkage studies of the locus. The results of this study, i.e. isolation of the full-length cDNA sequence of PAX4 and identification of the homologous human gene, will facilitate further functional and genetic studies of the PAX4 gene.

Medial medullary syndrome with contralateral face hypalgesia: A report of two cases

Classically, patients with unilateral medial medullary syndromes show contralateral deep sensory loss, contralateral hemiparesis, and ipsilateral tongue paralysis. We encountered two patients with medial medullary syndromes showing hypalgesia of the contralateral face. Both patients had contralateral deep sensory loss and hemiparesis, but no hypoglossal nerve palsy, so it was difficult to establish a medial medullary syndrome from the clinical neurological signs alone. Magnetic resonance images showed that the infarcted areas were located in the ventromedial area of the upper medulla, probably involving the trigeminothalamic tract in the medial lemniscus. We reviewed the reported cases of medial medullary syndromes and summarized their clinical features as well as the topography concerned with the associated sensory disturbances.

Identification of open reading frames in Schizosaccharomyces pombe cDNAs

A total of 214 non-overlapping cDNA clones from Schizosaccharomyces pombe were selected and completely sequenced. The clones not previously reported were divided into the following three groups: 1) homologous to Saccharomyces cerevisiae genes (139 clones); 2) homologous to genes from other organisms but not to those from Sac. cerevisiae (4 clones); and 3) no similar sequences (40 clones). Among the 31 sequences identical to those in the public databases, 4 genes have regions corresponding to introns. Protein sequences which had homologs both in budding yeast and mammals were compared with those from Sac. cerevisiae and mammals. The search revealed that the evolutionary distances among these species are similar at least with genes of this category.

Intra-arterial Thrombolytic Therapy for Acute Vertebrobasilar Artery Occlusion

SUMMARY

We report on the results of intra-arterial thrombolysis in 11 patients with vertebrobasilar artery occlusion treated within 6 hours after onset of symptoms. Urokinase (5 patients) or recombinant tissue plasminogen activator (t-PA) (6 patients) was injected through a microcatheter conducted to the thrombus. Eight patients showed recanalization of the thrombus. The outcome was excellent in 5 patients, good in 2 patients, and poor in one patient. Recanalization could not be achieved in 3 of the 11 procedures; all patients in whom recanalization failed died. There were no hemorrhagic complications after thrombolysis. Two patients with residual stenosis after thrombolysis underwent successful percutaneous transluminal angioplasty (PTA) to prevent reocclusion. Intra-arterial thrombolysis for vertebrobasilar artery occlusion is a safe and effective treatment if it is performed within 6 hours.

Endovascular Treatment for Tandem Internal Carotid Stenosis. Development of a New Shunt Tube for PTA

SUMMARY

Three patients with tandem internal carotid stenoses were treated in one operation including carotid endarterectomy (CEA) for the proximal stenosis and percutaneous transluminal angioplasty (PTA) for the distal stenosis. We devised a Y-shaped shunt tube which we used for CEA, while a PTA balloon catheter was introduced via the tube to perform PTA guided by portable digital subtraction angiography (DSA). No cerebrovascular events occurred during follow-up. Our approach avoids the risk of a second procedure while effectively treating tandem stenoses.

Metabolic inhibition enhances selective toxicity of L-DOPA toward mesencephalic dopamine neurons in vitro

Recent in vitro studies have described the toxicity of levodopa (L-DOPA) to dopamine (DA) neurons. We investigated whether metabolic inhibition with rotenone, an inhibitor of complex I of the mitochondrial respiratory chain, may enhance the toxicity of L-DOPA toward DA neurons in mesencephalic cultures. The uptakes of DA and GABA were determined to evaluate the functional and morphological integrity of DA and non-DA neurons, respectively. Pretreatment with rotenone significantly augmented the toxic effect of L-DOPA on DA neurons. Interestingly, prior metabolic inhibition with rotenone rendered DA cells susceptible to a dose (5 microM) of L-DOPA that otherwise exhibited no toxic effect. DA uptake was more intensely attenuated than GABA uptake after the combined exposure to rotenone and L-DOPA. This was confirmed by cell survival estimation showing that tyrosine hydroxylase-positive DA cells are more vulnerable to the sequential exposure to the drugs than total cells. The selective toxic effect of L-DOPA on rotenone-pretreated DA neurons was significantly blocked by antioxidants, but not antagonists of NMDA or non-NMDA glutamate receptors. This indicates that oxidative stress play a central role in mediating the selective damage of DA cells in the present experimental paradigm. Our results raise the possibility that long-term L-DOPA treatment could accelerate the progression of degeneration of DA neurons in patients with Parkinson's disease where potential energy failure due to mitochondrial defects has been demonstrated to take place.

Regulation of myosin phosphatase through phosphorylation of the myosin-binding subunit in platelet activation

Human platelets were found to contain myosin phosphatase consisting of a 38-kD catalytic subunit of protein phosphatase type 1delta, a 130-kD myosin-binding subunit (MBS) and a 20-kD subunit, all of which cross-reacted with antibodies against these subunits of smooth muscle myosin phosphatase. Anti-MBS antibody coimmunoprecipitated RhoA and Rho-kinase of human platelets. Platelets MBS is a substrate for Rho-kinase and phosphorylation of MBS decreases the activity of myosin phosphatase. Treatment of intact platelets with 9, 11-epithio-11,12-methano-thromboxane A2 led to a dramatic increase in phosphorylation of MBS and a significant decrease in the activity of myosin phosphatase. These findings suggest a putative mechanism for agonist-induced regulation of myosin phosphatase activity in platelets.

[Angiotensin I-converting enzyme gene polymorphism and renal disease]

ACE inhibitor is known to have a therapeutic efficacy in renal diseases by reducing proteinuria and maintaining renal function. However, the relationship between ACE gene polymorphism and renal disease has not been fully elucidated. In this study, a 287 base pair(bp) I/D polymorphism of the ACE gene was examined with polymerase chain reaction(PCR) in 100 healthy subjects, 34 patients with chronic glomerulonephritis(CGN), 29 with chronic renal failure(CRF) and 25 with diabetes mellitus(DM) with(13) and without(12) nephropathy. We also measured serum ACE activity of these patients. ACE genotype and derived allele frequencies in each disease group did not differ significantly from those in healthy subjects. In all disease groups, values of serum ACE activity were higher in genotype DD than in genotype II. These findings suggest no significant association between I/D polymorphism of the ACE gene and renal disease. Further studies are needed to clarify these findings, considering renal function and type of renal disease.

Clinical usefulness of the effective regurgitant orifice area determined by transesophageal echocardiography in patients with eccentric aortic regurgitation

BACKGROUND AND AIMS OF THE STUDY

The aortic regurgitant jet is frequently eccentric, and Doppler color flow mapping techniques of the distal jet is influenced by this eccentricity. The aim of the present study was to determine whether the effective regurgitant orifice area (EROA), determined by the proximal isovelocity surface area (PISA) method using multiplane transesophageal echocardiography (m-TEE), could be used to evaluate the severity of aortic regurgitation (AR) in patients with an eccentric jet.

METHODS

Forty-eight patients with eccentric AR were studied. Values of EROA determined by the PISA method were compared with results from cross-sectional area (CSA), vena contracta (VC) width, aortic angiography, and regurgitant fraction.

RESULTS

Values of EROA correlated well with results from CSA (r = 0.73, p < 0.001), VC (r = 0.74, p < 0.001), angiographic grade (rs = 0.90 p < 0.001), and regurgitant fraction (r = 0.84, p < 0.001) in patients with eccentric aortic regurgitation. Values of EROA > 0.27 cm2 were always associated with a regurgitant fraction > 0.4, while EROA values < 0.27 cm2 were always associated with a regurgitant fraction < 0.4.

CONCLUSIONS

We conclude that, in patients with an eccentric jet, measurement of EROA values by the PISA method using m-TEE is a reliable method of assessing the severity of AR.

Better prediction of protein cellular localization sites with the k nearest neighbors classifier

We have compared four classifiers on the problem of predicting the cellular localization sites of proteins in yeast and E. coli. A set of sequence derived features, such as regions of high hydrophobicity, were used for each classifier. The methods compared were a structured probabilistic model specifically designed for the localization problem, the k nearest neighbors classifier, the binary decision tree classifier, and the naïve Bayes classifier. The result of tests using stratified cross validation shows the k nearest neighbors classifier to perform better than the other methods. In the case of yeast this difference was statistically significant using a cross-validated paired t test. The result is an accuracy of approximately 60% for 10 yeast classes and 86% for 8 E. coli classes. The best previously reported accuracies for these datasets were 55% and 81% respectively.

Functional prediction of B. subtilis genes from their regulatory sequences

In bacterial cells, gene expression is regulated by multiple sigma factors, each of which has its promoter specificity, according to their conditions. Thus, if we can discriminate which sigma factor binds to the upstream region of a given coding sequence, we can predict in what condition it will be expressed. In this paper, we show this approach is feasible for the analysis of Bacillus subtilis genome. Based on our collection of known promoter sequences, we prepared 8 predictors to characterize known sigma factors using the hidden Markov model and their prediction accuracies were estimated with a cross-validation test. Furthermore, we predicted the sigma-dependencies for each of 1415 candidate genes in the genome. Our prediction results are experimentally testable and seem useful for the post-sequencing project.

Rehabilitation of patients with anosognosia for hemiplegia due to intracerebral haemorrhage

We have studied the differences in the lesions, concomitant symptoms and ADL levels in patients in acute-stage cerebral-haemorrhage and manifesting anosognosia. Twelve of 50 patients (24.0%) presented with anosognosia. The (+) group had longer intervals between onset and the first evaluation than did the (-) group, demonstrating severe sensory disturbance. The volume of haemorrhage was significantly larger in the (+) group. Anosognosia disappeared within 3 months in all cases. In the (+) group the time until discharge was long, with the ADL level at the time of discharge being low. Therefore, it was considered that anosognosia was important as an inhibitory factor hampering rehabilitation.

Visuospatial impairment and activities of daily living in patients with Parkinson's disease: a quantitative assessment of the cube-copying task

By using a cube-copying task, visuospatial impairment in patients with Parkinson's disease was identified and studied in relation to the performance IQ, neuropsychological symptoms, and activities of daily living. In addition, a quantitative assessment of the performance IQ was also attempted by establishing a scoring guideline for the copying task. The results indicated that the subjects' performances in the copying task correlated to motor function, visuospatial impairment, and the results from the mobility and social cognition subtests of the Functional Independence Measure. The quantitative evaluation of the results from the copying task also showed a high correlation to the patients' constructional ability, assessed by the Block design and the Object assembly tasks from the Wechsler Adult Intelligence Scale-Revised. This study demonstrated that visuospatial deficits in Parkinson's disease patients were associated with impairments in both activities of daily living and motor function. In addition, quantitative assessment of the copying task suggested that this test may be predictive of the nonverbal IQ. Therefore, we concluded that the copying task is a useful tool for the assessment of visuospatial impairment in patients with Parkinson's disease; these deficits may be associated with an increased risk of motor dysfunction such as difficulties in the activities of daily living.

Predictors of sinus rhythm restoration after Cox maze procedure concomitant with other cardiac operations

BACKGROUND

There have been sporadic cases of persistent atrial fibrillation and sick sinus syndrome after the maze procedure. The purpose of this study was to identify the predictors of sinus rhythm restoration after operation.

METHODS

Between March 1993 and June 1995, we evaluated retrospectively 96 consecutive patients who underwent the maze procedure (maze III) in combination with another type of cardiac operation. Four patients who died and 6 patients who required permanent pacemaker implantation because of sick sinus syndrome were excluded. Ambulatory electrocardiographic monitoring was evaluated 1 year after operation. Multiple logistic regression analysis was applied to identify the predictors of sinus rhythm restoration.

RESULTS

The final population comprised 86 patients (mean age, 59.8 years; 67 patients with mitral valve disease). Overall, sinus rhythm was restored in 68 of 86 patients (79.1%). The magnitude of the atrial fibrillatory wave positively predicted postoperative sinus rhythm restoration. Conversely, left atrial diameter was inversely related to postoperative sinus rhythm restoration. The odds ratio of having both a fine atrial fibrillatory wave (< 1.0 mm) and enlarged left atrial diameter (> or = 65 mm) for patients with sinus rhythm restoration was 0.04 (95% confidence interval, 0.01 to 0.28).

CONCLUSIONS

Atrial fibrillatory wave and left atrial diameter were independent predictors of sinus rhythm restoration after the maze procedure in patients with chronic atrial fibrillation and organic heart disease.

Demonstration of the facilitatory role of 8-OH-DPAT on cholinergic transmission in the rat hippocampus using in vivo microdialysis

The role of the serotonin (5-HT)1A receptor in the regulation of acetylcholine (ACh) release in the hippocampus was investigated using an in vivo microdialysis technique and a sensitive radioimmunoassay specific for ACh. The mean (+/- S.E.M.) basal ACh contents in the hippocampal perfusate of conscious, freely moving rats was 60 +/- 4 (n = 29) and 3691 +/- 265 fmol/30 min (n = 31), respectively, in the absence and presence of physostigmine (Phy) in the perfusion fluid. Systemic administration of 8-hydroxy-2-(di-n-propylamino)tetralin (8-OH-DPAT, 0.5 mg/kg, s.c.), a 5-HT1A agonist, significantly enhanced ACh release both in the presence and absence of Phy. Local application of 8-OH-DPAT (3-30 microM) into the hippocampus through the microdialysis probe significantly potentiated ACh release only in the presence of Phy, whereas no significant effect was observed in its absence. Pretreatment with NAN-190 (3 mg/kg, i.p.), a 5-HT1A antagonist, eliminated the increasing effect of systemically applied 8-OH-DPAT on ACh release, while NAN-190 alone had no effect on basal ACh release either in the absence or presence of Phy. Consistent with the time course of ACh release, systemic administration of 8-OH-DPAT evoked hyperlocomotion, which was reversed by NAN-190. However, local hippocampal application of 8-OH-DPAT did not affect the locomotor activity of the rats. These findings suggest that at least two different sites are involved in the 8-OH-DPAT-induced increase in the release of ACh in the rat hippocampus in vivo.

Is unilateral spatial neglect a single phenomenon? A comparative study between exploratory-motor and visual-counting tests

The aim of this study is to report the preliminary findings of a traditional battery of tests and our original battery capable of assessing the presence of components and extent of lesions in patients with unilateral spatial neglect. Thirty patients who had unilateral spatial neglect with a stroke in the right hemisphere were assessed for unilateral spatial neglect on exploratory-motor (E-M) tasks, visual-counting (V-C) tasks, and traditional neglect batteries at least 4 weeks after the onset. Other neuropsychological tests and computed tomography were also performed to investigate the relationship with neglect. A factor analysis showed that our tasks loaded significantly on three factors. E-M neglect was found in 16 patients, and V-C neglect in 22 patients with unilateral spatial neglect. There were high correlations between E-M neglect and motor paralysis, word fluency, backward digit span and motor impersistence. There were high correlations between V-C neglect and visual-field defect, line bisection, line cancellation and figure copying. Lesions in the frontal lobe, caudate, insula, and anterior portion of the paraventricular white matter were commonly associated with E-M neglect. Lesions in the occipital lobe were also associated with V-C neglect. We suggest that unilateral neglect is not a single phenomenon, but rather involves several different components. We propose that E-M and V-C tasks are useful methods for evaluating the extent of lesions in patients with unilateral spatial neglect.

Cerebral angioplasty in a patient with vascular dementia

A 66-year-old man with a history of previous transient ischemic attacks had progressive memory and gait disturbance caused by severe stenoses of both the internal carotid arteries and vertebral arteries. The patient underwent percutaneous transluminal angioplasty of the vertebral arteries and endarterectomy of the internal carotid arteries with satisfactory results. On admission, the patient was alert, but disoriented to time and place. He exhibited mild motor weakness in both legs. Neuropsychological tests revealed remarkable intellectual deterioration and he required maximum support to perform activities of daily living. Higher cortical function and the ability to perform activities of daily living improved remarkably after the angioplasty. Angioplasty is an alternative therapy to reverse functional deficits in patients with cerebrovascular hemodynamic compromise.

[Spontaneous intracranial hypotension with severe headache and typical neuroradiological findings: report of two cases]

Intracranial hypotension causes the postural headache that sometimes follows lumbar puncture. When postural headache and associated symptoms occur after lumbar puncture, the diagnosis is usually obvious. However, similar symptoms may occur after minor trauma or without an obvious precipitating cause (spontaneous intracranial hypotension: SIH). SIH is rare, but is now increasingly recognized as a cause of postural headache. We encountered two cases of SIH showing typical neuroradiological findings. Case 1 is a 47-year-old man who was admitted with severe frontalgia. CT scan revealed vague visualization of bilateral Sylvian fissures and slit ventricles. Spinal fluid pressure was 6cm H2O in the lateral recumbent position. Cerebrospinal fluid (CSF) showed slight lymphocytic pleocytosis. We treated him as having viral meningitis. His headache improved gradually and he was discharged 2 weeks later with slight occipitalgia. One week after discharge, he complained of severe headache again and plain CT showed bilateral subdural hematoma. The subdural hematoma in both sides was evacuated and his headache improved after the operation. Follow-up CT scans two months later showed normalization of ventricle size and cisterns. Case 2 is a 52-year-old woman who was admitted with severe occipitalgia. CT scan on admission showed slit ventricles and the disappearance of the suprasellar cistern and the Sylvian fissure. Spinal fluid pressure was 3cm H2O. Gd-enhanced MRI showed remarkable meningeal enhancement and effacement of the optic chiasm suggesting brain sagging. Her headache improved 2 weeks later after strict bed rest and oral pain relief drugs. The follow-up MRI showed disappearance of abnormal meningeal enhancement and normalization of optic chiasma effacement. SIH is one of the important differential diagnoses of patients complaining of postural headache. Meningeal enhancement of gadolinium-enhanced MRI is an important finding to diagnose SIH. We have to consider SIH when diagnosing postural headache.

Subdural and meaningful involvement related to Wegener's granulomatosis: case report

OBJECTIVE AND IMPORTANCE

The first case of Wegener's granulomatosis associated with subdural empyema is presented.

CLINICAL PRESENTATION

A 37-year-old man was admitted to our hospital for treatment of bilateral subdural masses. Magnetic resonance imaging demonstrated strong bilateral subdural and meningeal enhancement. The patient was treated with subdural drainage, based on the diagnosis of bilateral subdural hematoma or empyema as revealed by magnetic resonance imaging. Even after surgery, he developed systemic symptoms that are typical for Wegener's granulomatosis, including hemosputum, papules, peripheral nervous disorders, hematuria, myalgia, and joint pain. A diagnosis of Wegener's granulomatosis was confirmed by positive circulating antineutrophil cytoplasmic antibodies and histological findings from the skin and nasal mucosa. We diagnosed the subdural masses as Wegener's granulomatosis from the laboratory and neuroimaging studies, retrospectively.

INTERVENTION

Pus-like fluid containing hematoma with negative micro-organism was evacuated by surgery.

CONCLUSION

Wegener's granulomatosis should be suspected in young patients with pulmonary symptoms and subdural hematoma without head injury. This is the first case of Wegener's granulomatosis associated with subdural masses.