Fluorine-doped SiO2 glasses for F2 excimer laser optics: fluorine content and color-center formation

Color-center formation in F-doped, OH-free synthetic SiO(2) glasses by irradiation with F(2) excimer lasers (157 nm) was examined as a function of the F content. The concentration of photoinduced E(') centers was reduced to approximately 1/20 by 1 mol.% F(2) doping and remained almost constant on further doping to 7.3 mol. %. The absorption edge was considerably shifted to a lower wavelength (157.4 nm -->153 nm for a 5-mm-thick sample) by 1-mol. % doping and decreased only slightly on further doping. The intensities of the Raman bands that are due to three- and four-membered ring structures were significantly reduced by 1-mol. % F doping. These results strongly suggest that elimination of strained Si-O-Si bonds by F doping plays a central role in the improvement of radiation resistance of SiO(2) glasses to F(2) laser light.

High expression of doublecortin and KIAA0369 protein in fetal brain suggests their specific role in neuronal migration

The X-linked subcortical laminar heterotopia and lissencephaly syndrome is a disorder of neuronal migration caused by a mutation in XLIS, a recently cloned gene on chromosome Xq22.3-q23. The predicted protein product for XLIS, doublecortin (DC), shows high homology to a putative calcium calmodulin-dependent kinase, KIAA0369 protein (KI). Here we identified DC and KI in the brains of human and rat fetuses by immunochemical and immunohistochemical means. In this study, Western blotting demonstrated that both DC and KI are specific to the nervous system and are abundant during the fetal period, around 20 gestational weeks in humans and embryonic days 17 to 20 in rats. Immunostaining of the developing neocortex disclosed localization of DC and KI immunoreactivities in neuronal cell bodies and processes in the zones of ongoing neuronal migration. Although KI showed a somewhat wider distribution than DC, the temporal and spatial patterns of their expression were similar. These results suggest that DC and KI participate in a common signaling pathway regulating neuronal migration.

The molten globule state of a chimera of human alpha-lactalbumin and equine lysozyme

The molten globule state of equine lysozyme is more stable than that of alpha-lactalbumin and is stabilized by non-specific hydrophobic interactions and native-like hydrophobic interactions. We constructed a chimeric protein which is produced by replacing the flexible loop (residues 105-110) in human alpha-lactalbumin with the helix D (residues 109-114) in equine lysozyme to investigate the possible role of the helix D for the high stability and native-like packing interaction in the molten globule state of equine lysozyme. The stability of the molten globule state formed by the chimeric protein to guanidine hydrochloride-induced unfolding is the same as that of equine lysozyme and is substantially greater than that of human alpha-lactalbumin, although only six residues come from equine lysozyme. Our results also suggest that the non-native interaction in the molten globule state of alpha-lactalbumin changes to the native-like packing interaction due to helix substitution. The solvent-accessibility of the Trp residues in the molten globule state of the chimeric protein is similar to that in the molten globule state of equine lysozyme in which packing interaction around the Trp residues in the native state is partially preserved. Therefore, the helix D in equine lysozyme is one of the contributing factors to the high stability and native-like packing interaction in the molten globule state of equine lysozyme. Our results indicate that the native-like packing interaction can stabilize the rudimentary intermediate which is stabilized by the non-specific hydrophobic interactions.

Multicenter study of paroxysmal dyskinesias in Japan--clinical and pedigree analysis

To investigate the clinical features of paroxysmal dyskinesias and carry out a pedigree analysis, we conducted a multicenter survey in Japan. A questionnaire was mailed to 229 medical institutions. A total of 150 patients with paroxysmal kinesigenic choreoathetosis (PKC), including 53 sporadic cases and 97 affected individuals from 32 pedigrees, were identified. The mean age of onset of PKC was 8.8 years, and 80% of the cases were men. Of the 32 pedigrees with familial occurrence, 18 (56%) were compatible with an autosomal-dominant inheritance (AD) with complete penetrance, and seven (22%) had AD with incomplete penetrance; the remaining seven were sibling recurrence cases with apparently healthy parents. In six of seven familial cases with incomplete penetrance, the disease gene was thought to be transmitted by clinically unaffected females. Paroxysmal dystonic choreoathetosis (PDC) was found in five cases, including two sporadic cases and three affected individuals from two pedigrees; the mean age of onset was 0.6 years, and a male predominance was noted (male:female = 4:1). There was one case of paroxysmal hypnogenic dyskinesia and one case of paroxysmal exertion-induced dyskinesia. There is an unexplained male predominance for paroxysmal dyskinesias. When the genetic defect of patients with paroxysmal dyskinesias is identified, the pathophysiology of the disease will become more clear.

Development of telencephalin in the human cerebrum

Telencephalin (TLN) is a 130kDa, type 1 integral membrane glycoprotein of the immunoglobulin superfamily found in the mammalian central nervous system. TLN shows a molecular structure resembling intercellular adhesion molecules-1 and -3, and binds to the CD11a/CD18 leukocyte integrin. TLN was localized to neuronal dendrites in the telencephalic gray matter: cerebral cortex and basal ganglia. We studied immunohistochemically the expression of TLN in the developing human brain. In the hippocampus, TLN immunoreactivity appeared at 29 gestational weeks (GW), intensified subsequently, and persisted into adulthood. In the temporal cortex, labeling was weak and restricted to the cytoplasm of pyramidal neurons from 35 to 39 GW, but thereafter became diffuse and intense in the cortical layers, especially the molecular layer, by 5 months of postnatal age. The development of TLN was late compared to synaptophysin and microtubule-associated protein 2, suggesting its involvement in the functional maturation of neuronal dendrites and synapses.

Photochemical processes induced by 157-nm light in H(2)-impregnated glassy SiO(2):OH

F(2) excimer-laser irradiation induces two major changes in SiO(2): OH glass impregnated with H(2) molecules. First, the vacuum-UV optical absorption edge is bleached, and the absorption at 157 nm decreases from 0.95 to 0.68 cm(-1) . Second, preexisting free SiOH groups and interstitial H(2) are photochemically converted to hydrogen-bonded hydroxyl groups. It is suggested that the bleaching of the UV-absorption edge is caused by a change of OH groups from a free to a hydrogen-bonded state and by photolysis of distorted Si-O bonds that are absorbing in the edge region.

Skin eruption as the presenting sign of Hunter syndrome IIB

We present a case of Hunter syndrome diagnosed because of skin eruption. A 4-year-old Japanese boy presented with a 3-4-months history of papular lesions on the back and extremities. His growth and development were almost normal. His face was not of coarse appearance. He had multiple, whitish to skin-coloured, papules and nodules symmetrically distributed on the scapular regions and the extensor aspects of the upper arms and thighs. There was no family history of similar symptoms. Skin biopsy showed the deposition of a considerable amount of mucin in the dermis. Although physical examinations failed to detect any other signs of Hunter syndrome, X-rays showed the characteristic features of mucopolysaccharidosis: deformities of the vertebral bone, ribs, and pelvis. Mucopolysaccharide analysis of the urine revealed a marked increase in dermatan sulphate and heparan sulphate. The activity of iduronate sulphatase in the lymphocytes was deficient, which was diagnostic for Hunter syndrome. We emphasize that the skin eruption can be the earliest sign of Hunter syndrome, particularly in the mild form presenting with normal development and growth.

Interleukin-8 inhalation directly provokes bronchoconstriction in guinea pigs

BACKGROUND

Although it has been reported that the concentration of interleukin (IL)-8 in nasal lavage fluid and sputum and its production in bronchial epithelium were increased in asthmatic subjects, the direct effects of IL-8 on the airways in vivo is unclear.

METHODS

We examined bronchoconstriction in response to IL-8 inhalation through an endotracheal cannula in anesthetized, artificially ventilated guinea pigs.

RESULTS

Inhalation of IL-8 at concentrations of 1 and 10 microg/ml caused significant bronchoconstriction, as revealed by the elevation of pressure at the airway opening. Moreover, the bronchoconstriction induced by IL-8 was significantly inhibited by the antihistamines diphenhydramine and terfenadine, suggesting the involvement of histamine release in the IL-8-induced bronchoconstriction. No significant leukocyte infiltration was observed in the bronchoalveolar lavage fluid or histologic findings 25 min after the first IL-8 inhalation.

CONCLUSIONS

IL-8 provokes bronchoconstriction without leukocyte accumulation in the airways, mediated in part by histamine release, in guinea pigs.

[Brain malformation and apoptosis]

Apoptosis is a physiological phenomenon that occurs extensively in the developing central nervous system (CNS). The death of neural cells is strictly controlled by the bcl-2 family and other regulatory systems. In particular, neurons are prevented from undergoing apoptosis by multiple mechanisms such as their intracellular control device and neurotrophic factors delivered by their innervating neurons, target cells and surrounding glial cells. A defect in any of these may cause a CNS malformation due to massive neuronal death.

Expression of protective protein in human tissue

The authors investigated by immunohistochemistry the distribution of protective protein in human tissues. Immunoreactivity was observed in the cytoplasm, revealing a granular pattern and cell type specificity. The most intense staining was observed in the large neurons of brain, distal and collecting tubular cells of kidney, epithelial cells of bronchus, and Leydig cells of testis. In a patient with galactosialidosis type IIa, all these stains were absent. The neurons that were most strongly stained in the control group, such as the Betz cells, neurons in the basal forebrain, motor neurons in the cranial nerve nuclei, and ventral horn cells of the spinal cord, were markedly ballooned in the patient with galactosialidosis.

[A case of ophthalmoplegic migraine: swelling and Gd-DTPA enhancement of the oculomotor nerve on MRI]

We report here a 9-year-old girl with ophthalmoplegic migraine. At the age of 2 years and 6 months she first developed left ptosis and ophthalmoparesis that resolved gradually within 2 weeks. She experienced similar episodes repeatedly. After 5 years of age, left periorbital pulsatile pain preceded ptosis and ophthalmoparesis, and after 7 years, she showed permanent left third nerve paresis even between the attacks. On cranial MRI the left oculomotor nerve showed swelling and contrast enhancement, the latter being more prominent in the ictal than interictal images. Ophthalmoplegic migraine should be considered in the differential diagnosis of opthalmoplegia in children even in the absence of headache. The diagnosis is strongly suspected when MRI demonstrates swelling and enhancement of the oculomotor nerve.

The expression of late infantile neuronal ceroid lipofuscinosis (CLN2) gene product in human brains

We raised polyclonal antibodies against a gene product responsible for late infantile neuronal ceroid lipofuscinosis (CLN2). By Western blotting, all three antisera recognized the CLN2 protein at approximately 49 kDa in human brain homogenates. Immunohistochemistry using the antisera demonstrated the granular labelling in the cytoplasm of cerebral neurons and glial cells. The immunoreactivity on Western blots was absent from the brain of a patient with CLN2. Our results suggest the usefulness of these antibodies for the diagnosis of CLN2, which currently requires demonstration of characteristic ultrastructure by electron microscopy.

A large-scale mitochondrial DNA deletion causing progressive ataxia

Mitochondrial diseases are characterized by heteroplasmic mitochondrial DNA mutations and multisystemic dysfunction. Base substitutions of mitochondrial DNA have been reported in mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episodes (MELAS), 1,2 myoclonus epilepsy with ragged red fibers (MERRF), 3 and other neuromuscular disorders.4 Heteroplasmic mitochondrial DNA deletions are usually detected in chronic external ophthalmoplegia, including Kearns-Sayre syndrome, 5 and on rare occasions in Pearson marrow-pancreas syndrome.6 A few unusual clinical complexes associated with single mitochondrial DNA deletions have been reported, such as maternally transmitted diabetes and deafness,7 diffuse leukodystrophy,8 MELAS, Fanconi's syndrome,9 pure myopathy and neuropathy,10 myopathy with lipomatosis, 11 and Leigh-type neuropathology.12

We report here a patient with a large-scale mitochondrial DNA deletion, which was located at a novel site and produced an atypical Kearns-Sayre syndrome phenotype. The major clinical sign at the early stage was not ophthalmoplegia, but cerebellar ataxia.

Equilibrium and kinetics of the folding of equine lysozyme studied by circular dichroism spectroscopy

The equilibrium unfolding and the kinetics of unfolding and refolding of equine lysozyme, a Ca2+-binding protein, were studied by means of circular dichroism spectra in the far and near-ultraviolet regions. The transition curves of the guanidine hydrochloride-induced unfolding measured at 230 nm and 292.5 nm, and for the apo and holo forms of the protein have shown that the unfolding is well represented by a three-state mechanism in which the molten globule state is populated as a stable intermediate. The molten globule state of this protein is more stable and more native-like than that of alpha-lactalbumin, a homologous protein of equine lysozyme. The kinetic unfolding and refolding of the protein were induced by concentration jumps of the denaturant and measured by stopped-flow circular dichroism. The observed unfolding and refolding curves both agreed well with a single-exponential function. However, in the kinetic refolding reactions below 3 M guanidine hydrochloride, a burst-phase change in the circular dichroism was present, and the burst-phase intermediate in the kinetic refolding is shown to be identical with the molten globule state observed in the equilibrium unfolding. Under a strongly native condition, virtually all the molecules of equine lysozyme transform the structure from the unfolded state into the molten globule, and the subsequent refolding takes place from the molten globule state. The transition state of folding, which may exist between the molten globule and the native states, was characterized by investigating the guanidine hydrochloride concentration-dependence of the rate constants of refolding and unfolding. More than 80% of the hydrophobic surface of the protein is buried in the transition state, so that it is much closer to the native state than to the molten globule in which only 36% of the surface is buried in the interior of the molecule. It is concluded that all the present results are best explained by a sequential model of protein folding, in which the molten globule state is an obligatory folding intermediate on the pathway of folding.

Role of tachykinins in distilled water-induced bronchoconstriction in guinea-pigs

BACKGROUND

An inhalation of ultrasonically nebulized distilled water (UNDW) induces bronchoconstriction only in asthmatics, but the mechanism underlying the response is not fully understood. We recently showed that bronchoconstriction occurs immediately after UNDW is inhaled 20min after an aerosolized antigen challenge in passively sensitized guinea-pigs.

OBJECTIVE

This study was conducted to examine the role of tachykinins in this response.

METHODS

Passively sensitized animals were anaesthetized and artificially ventilated, and changes in pressure at the airway opening (Pao) were measured as an overall index of airway narrowing. A tachykinin NK1 and NK2 dual receptor antagonist, FK224, and a tachykinin NK1 selective antagonist, FK888, were intravenously administered 15 min after the antigen challenge. The effects of capsaicin desensitization and a neutral endopeptidase inhibitor, phosphoramidon, were also examined.

RESULTS

FK224 and FK888 significantly (P < 0.05 and P < 0.05, respectively) reduced the time course curve of the increase in Pao caused by UNDW inhalation in a dose-dependent manner. The percentage increase in Pao from the preantigen challenge value at 1 min after the UNDW inhalation was 267.4+/-17.1, 358.0+/-33.7 and 412.4+/-27.6% with 10 mg/kg of FK224, 1.0 mg/kg of FK224 and vehicle, respectively, (P<0.01 between 10 mg/kg of FK224 and vehicle) and the value was 254.4+/-48.5% with 10 mg/kg of FK888, 327.1+/-57.6% with 1.0 mg/kg of FK888 and 418.5+/-39.0% with vehicle, respectively (P < 0.05 between 10 mg/kg of FK888 and vehicle). The capsaicin desensitization, but not phosphoramidon, significantly reduced the UNDW-induced increase in Pao.

CONCLUSION

These results suggest that tachykinins, at least substance P, are involved in a part of the UNDW-induced bronchoconstriction in our guinea-pig model.

[Acute necrotizing encephalopathy of childhood: recent advances and future prospects]

Acute necrotizing encephalopathy of childhood (ANE) is a clinicopathological entity recently separated from acute encephalopathy of unknown etiologies. The hallmark of ANE is multiple, bilateral symmetric brain lesions showing edema and necrosis which occur in the bilateral thalami and other specific regions. Since its establishment in 1993-1995, data have further accumulated and have provided additional insight into its pathogenesis. This review summarizes recent achievements on ANE, with reference to issues to be clarified by future studies.

Expression of a 45K subunit of platelet-activating factor acetylhydrolase in the developing mouse cerebellum

The 45K subunit of platelet-activating factor acetylhydrolase (PAFAH-45K) is the product of a candidate gene for Miller-Dieker lissencephaly. We studied the expression of this protein in the developing mouse cerebellar cortex by immunochemical and immunohistochemical methods. Western blotting studies indicated that PAFAH-45K is more abundant in the fetal than the postnatal period. Immunohistochemical studies revealed developmental changes in the localization of PAFAH-45K-immunoreactivity, which shifted from the somata of Purkinje cells to the neuropil of the molecular layer. Our findings indicate that PAFAH expression is developmentally regulated and suggest its role in histogenetic processes in the cerebellar cortex other than neuronal migration.

Loss of neurofibromin in the leptomeningeal astroglial heterotopia of NF-1

Neurofibromin, the protein product of the neurofibromatosis type 1 (NF-1) gene, has important roles in tumor suppression or normal embryogenesis. Cerebellar leptomeningeal astroglial heterotopia (LAH) is a proliferation of heterotopic astroglial cells and fibers in the cerebellar leptomeninges, which is characteristically demonstrated in the NF-1 patients. In this study, neurofibromin expression was investigated in NF-1 and non-NF-1 human tissues, especially in the cerebellum of NF-1 patients. Neurofibromin was found by immunoblotting in the CNS but not in the heart, liver, and kidney. Immunohistochemistry in the normal areas of the brains with NF-1 demonstrated neurofibromin immunoreactivity as did the brains of unaffected controls. Cerebellar LAH showed no neurofibromin immunoreactivity. The results of this study suggest that neurofibromin expression remains unchanged in the nonproliferated region of the CNS of the NF-1 patient but changes occur in the abnormally proliferated region, resulting in cerebellar LAH. Loss of neurofibromin may result in the excessive migration and growth of astrocytes in the early fetal period.

Developmental and aging changes of Bak expression in the human brain

The gene bak regulates apoptosis. To explore its role in the human central nervous system, we examined the distribution of its protein product, Bak, in the brains at various ages, by immunochemical and immunohistochemical means. Western blotting revealed that Bak expression in the cerebrum and cerebellum is high in the brains of the fetuses and elderly subjects, but low in those of young adults. Immunostaining of the cerebellum localized Bak immunoreactivity to Purkinje cells, which was strong in the fetal period and senescence, but undetectable from infancy to adolescence. These results suggest that bak regulates neuronal death associated with the development and aging of the central nervous system.

Tuberin immunohistochemistry in brain, kidneys and heart with or without tuberous sclerosis

We have studied immunohistochemically the expression of tuberin, the protein product of the TSC2 gene, in cerebral, renal and cardiac tissues obtained from patients with tuberous sclerosis and from control patients. Tuberin immunoreactivity was moderate to strong in neurons and reactive astrocytes of control brains, but was reduced in brains with tuberous sclerosis. Staining intensity of abnormal giant cells varied from negative to moderate in cortical tubers, subependymal nodules and subependymal giant cell astrocytomas. In control kidneys, uriniferous and collecting tubules showed positive immunoreactivity, whereas a focal decrease in their staining intensity was noted in kidneys with tuberous sclerosis. Renal angiomyolipomas were negative for tuberin. In the heart, cardiac muscles in both control and tuberous sclerosis patients were strongly immunoreactive. Cardiac rhabdomyomas in the latter were stained less intensely. These results provide histological evidence for the loss of tuberin in tuberous sclerosis tissues, which is associated with the development of hamartomas in an organ-specific manner.

Gastrointestinal submucosal tumors: evaluation with endoscopic US

PURPOSE

To describe the endoscopic ultrasound (US) features of benign versus malignant submucosal tumors throughout the gastrointestinal tract.

MATERIALS AND METHODS

One hundred nine patients aged 24-81 years suspected to have submucosal tumors (11 esophageal, 41 stomach, 24 duodenal, and 33 colorectal tumors) at barium studies or endoscopy underwent endoscopic US. The layer of origin, internal echo pattern, and lesion margin were analyzed by means of consensus and independent interpretation by three radiologists.

RESULTS

Endoscopic US findings revealed several distinct patterns among various submucosal tumors. Sixteen (94%) of the 17 homogeneous lesions with histopathologic findings of malignancy were hypoechoic, although 29 (43%) of the 68 homogeneous lesions with histopathologic findings of benignity were similarly hypoechoic. Homogeneous lesions that were anechoic, of intermediate echogenicity, or hyperechoic were almost exclusively benign (39 [98%] of 40). In contrast, 23 (96%) of the 24 malignant lesions were heterogeneous (n = 7) or homogeneously hypoechoic (n = 16). The sizes of benign and malignant lesions were significantly different (P < .05). There was no significant difference in the echo pattern (i.e., homogeneous versus heterogeneous), but there was a significant difference in the proportion of hypoechoic versus nonhypoechoic lesions (anechoic, hyperechoic, or of intermediate echogenicity; P < .001).

CONCLUSION

The differential diagnosis of gastrointestinal submucosal tumors is assisted with endoscopic US.

Fourier-transform infrared spectroscopic studies on the coordination of the side-chain COO- groups to Ca2+ in equine lysozyme

Interactions between Ca2+ and the Asp side chains in the Ca2+-binding site of equine lysozyme were investigated by Fourier-transform infrared (FT-IR) spectroscopy. In the spectrum of equine lysozyme, the intensities of the bands at about 1595 cm-1 and 1578 cm-1 in the region of the COO antisymmetric stretches increased upon Ca2+ binding. In the region of the COO- symmetric stretches, the loss of intensity at about 1388 cm-1 and gains of intensities at about 1423 cm-1 and 1403 cm-1 were observed due to Ca2+ binding to equine lysozyme. The spectral changes for equine lysozyme indicate that the COO- groups of Asp85, Asp90 and Asp91 in the Ca2+-binding site coordinate to Ca2+ in the pseudo-bridging mode, where divalent metal cation is bound to one of the two oxygens in the COO- group and a water molecule is hydrogen bonded to the other oxygen. The results presented here provide further evidence for a high degree of similarity between Ca2+-binding lysozyme and alpha-lactalbumin. The effects of Ca2+ binding on the main-chain conformation of equine lysozyme were compared with those of bovine alpha-lactalbumin and hen egg-white lysozyme.

FT-IR study of the Ca2+-binding to bovine alpha-lactalbumin. Relationships between the type of coordination and characteristics of the bands due to the Asp COO- groups in the Ca2+-binding site

Fourier-transform infrared spectroscopy (FT-IR) was applied to examine relationships between the type of coordination and the COO- antisymmetric and symmetric stretches of the COO- groups in the Ca2+-binding site of bovine alpha-lactalbumin. The peaks at 1593, 1578, 1425, and 1403 cm(-1) were assigned to the COO- groups of Asp-82, 87, and 88 coordinating to Ca2+ in the pseudo bridging mode, according to the results of X-ray crystallography. The bands due to the COO- groups were quite similar to each other between alpha-lactalbumin and EDTA which is the model compound for the pseudo bridging state.

Endoscopic submucosal tumorectomy for gastrointestinal submucosal tumors restricted to the submucosa: a new form of endoscopic minimal surgery

BACKGROUND

Endoscopic minimally invasive therapy for submucosal tumors of the gastrointestinal tract by use of endoscopic ultrasound has not yet come into widespread use, and this technique has not been fully evaluated. We therefore investigated this method of treatment in patients with gastrointestinal submucosal tumors.

METHODS

Forty-five patients with suspected gastrointestinal submucosal tumors (esophagus [5], stomach [1], duodenum [16], colon [23]) based on barium enema studies and endoscopy underwent endoscopic ultrasound by the water-filled or balloon method. The layer of origin and the internal echogenicity of the lesions were evaluated. After confirming that the tumors were submucosal, the lesions were resected using injection of physiological saline solution and electrocautery.

RESULTS

Using a one-channel or two channel method, all tumors were completely resected without serious complications and the diagnosis was histologically confirmed. Ulceration at the site of resection healed within 2 to 4 weeks (mean 23 days) and there has been no local recurrence.

CONCLUSIONS

Our technique of endoscopic submucosal tumorectomy appears to be a safe and useful diagnostic-cum-therapeutic procedure for gastrointestinal submucosal tumors.