Homogeneity of kerato-epithelin codon 124 mutations in Japanese patients with either of two types of corneal stromal dystrophy.
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Adult↗
Biomedical subjects
M Yamada
Publications and source records attributed to M Yamada.
Coherent detection techniques in optical imaging of tissues.
To form optical images from the transmitted or reflected light that is multiply scattered inside biological tissue, several detection techniques that extract the least-scattered photons or path-resolved photons have been developed. This paper reviews the coherent detection techniques. Emphasis is put on coherent detection imaging methods based on optical heterodyning, whose attractive features include quantum-noise-limited sensitivity, wide dynamic range, and excellent directionality and selectivity. Coherent detection methods have been implemented to achieve laser computed tomography and micrometre-resolution cross-sectional images in both in vivo and in vitro biological systems. Imaging works by ourselves and others are described, and an experimental study on coherent photon migration through highly scattering media is described to aid the understanding of the coherent detection method in selectively detecting the signal-carrying photons.
Diagnostic Imaging↗
Genomic organization of the OS-9 gene amplified in human sarcomas.
The OS-9 gene is frequently amplified in human sarcomas. We isolated and characterized an OS-9 genomic DNA from a human BAC library. Sequencing of the genomic DNA showed that the gene spanned approximately 30.4 kbp and had 15 exons. The 1,010 bp sequence of the 5' upstream region was also determined. The potential binding-sequence motifs TATA and CCAAT for general transcription factors were found in the 5' upstream region. Primer extension analysis revealed two putative transcription start sites. The significance of the 5' upstream sequence in the ubiquitous expression of the OS-9 gene in various tissues and culture cells is discussed.
Base Sequence↗
High-resolution immuno-scanning electron microscopy using a non-coating method: study of herpes simplex virus glycoproteins on the surface of virus particles and infected cells.
The expression of two glycoproteins, i.e. glycoprotein C (gC) and glycoprotein D (gD), of herpes simplex virus type 1 (HSV-1) on the surface of extracellular particles of this virus was examined by immuno-scanning electron microscopy. Scanning electron microscopy specimens of infected cells immuno-labelled against the glycoproteins with colloidal gold particles were prepared by a conventional coating and a non-coating method. Surface ultrastructure of infected cells and gold particles were observed more clearly with specimens prepared by the non-coating method. The appearance of virus particles in association with glycoprotein expression on these particles and on the surface of infected cells was then studied. Progeny virus particles began to appear 6 h after infection, increased in number as the infection proceeded, and covered most of the cell surface by 16 h. Six to 24 h after the infection, the labelling density for each glycoprotein on virus particles remained constant. The labelling density for gD was always higher than that for gC. The patch-like distribution of gold-labelling against gD was often detected on infected cell monolayers at the exponential and late stage of one cycle of virus growth. The labelling density for gD on virus particles was the highest on these produced in Vero and L-929 cells, moderate in MRC-5, BHK-21 and FL cells, and the lowest in HEp-2 cells.
Animals↗
Studies on the SEM examination of un-coated non-conductive specimens prepared by plasma-ion shower method.
The plasma-ion shower method is an effective technique for the SEM examination of un-coated electrically non-conductive specimens. However, milling damage to specimens cannot be prevented by the irradiation method using accelerated Ar ion beam. We, therefore, applied positive ions obtained by plasma discharge to the specimen like a shower by reflecting from the target electrode surface. He, N2 or Ar was used as the environmental gas, and the discharge voltage was varied from 200 V to 1000 V. At 5 kV to 25 kV of SEM accelerating voltage, it was possible to visualize un-coated hard and soft biological and inorganic specimens under 5 mA or 10 mA of discharge current and 5 min or 10 min of processing time.
Adult↗
The use of a nasogastric tube as an aid in blind nasotracheal intubation: a postscript.
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Humans↗
Mass effect caused by clinically unruptured cerebral arteriovenous malformations.
OBJECTIVE: It is generally considered that mass effect caused by arteriovenous malformations (AVMs) is evidence of ruptures. In the present study, the incidence of mass effect in clinically unruptured AVMs was evaluated, and the underlying causative factors and pathophysiological mechanisms were studied. METHODS: Twenty-seven patients with clinically unruptured supratentorial pial AVMs were examined. The majority were suffering from epilepsy, and frontal lobe involvement was revealed in approximately half of the patients. Angiographic studies, computed tomographic scans, and magnetic resonance images were obtained for all patients. Twenty-one patients underwent removal of AVMs. In 10 of the surgically treated patients, intraoperative vascular pressure measurements were obtained before removal of the AVMs. RESULTS: Mass effect was detected in 12 (44%) of the 27 patients. Cortical sulci obliteration (eight patients) and lateral ventricle displacement (seven patients) were frequently noted. The volume of AVMs was significantly larger in patients with mass effect than in those without mass effect (P < 0.001). Large dilated venous sacs or ectatic veins were observed to be associated with mass effect (P < 0.001). In only one patient was gross displacement related to a surrounding massive brain edema. Draining vein pressure in patients with mass effect was significantly elevated as compared to the average value in patients without mass effect (22 +/- 5 versus 12 +/- 3 mm Hg) (P < 0.01). CONCLUSION: The present study suggests that mass effect is not infrequent in clinically unruptured AVMs. Furthermore, multiple causative factors were detected, including the large size of AVMs, marked draining vein dilatation, and brain edema around the AVMs. Findings also indicated that a pathophysiologically high pressure in the venous drainage system may contribute to mass effect.
Adolescent↗
Transmission of human herpesvirus 7 through multigenerational families in the same household.
BACKGROUND: Human herpesvirus 7 (HHV-7) closely resembles HHV-6 and to a lesser degree cytomegalovirus. HHV-7 infection is usually acquired during early childhood. Primary infection can cause a roseola-like illness but in most cases it is only mildly symptomatic. The majority of adults are seropositive and in contrast to HHV-6 and cytomegalovirus infection, they continue to secrete the virus in their saliva for many years. The mode of intrafamilial transmission of this virus is not well-understood. METHODS: Saliva samples for virus isolation and DNA restriction analysis were obtained from all 47 members of 6 Japanese families, including 4 families with 3 generations living in the same household. RESULTS: HHV-7 was isolated from 43 of 47 saliva samples collected from children and adult members of the 6 families (91.5%). In one family the restriction patterns of the maternal grandmother, the mother and the children were similar, and the patterns of the paternal grandmother and the father were similar. In another family the patterns of the father and 5 of 6 children were similar, and those of the mother and the other child were similar. Altogether similar HHV-7 restriction profiles with his or her mother were found in 48% of offspring, and similar profiles with his or her father were found in 28% of offspring. CONCLUSIONS: The results strongly suggested horizontal transmission of HHV-7 from grandparents to parents to children through close contact within a household. Either parent could transmit HHV-7 to the children.
Adolescent↗
Escherichia coli is unable to produce pyrroloquinoline quinone (PQQ).
Many bacteria can synthesize the cofactor pyrroloquinoline quinone (PQQ), a cofactor of several dehydrogenases, including glucose dehydrogenase (GCD). Among the enteric bacteria, Klebsiella pneumoniae has been shown to contain the genes required for PQQ biosynthesis. Escherichia coli and Salmonella typhimurium were thought to be unable to synthesize PQQ but it has been reported that strain EF260, a derivative of E. coli FB8, can synthesize PQQ after mutation and can oxidize glucose to gluconate via the GCD/PQQ pathway (F. Biville, E. Turlin & F. Gasser, 1991, J Gen Microbiol 137, 1775-1782). We have re-investigated this claim and conclude that it is most likely erroneous. (i) Strain EF260, isolated originally by Biville and coworkers, was unable to synthesize a holo-enzyme GCD unless PQQ was supplied to the growth medium. No GCD activity could be detected in membrane fractions. (ii) The amount of PQQ detected in the growth medium of EF260 was very low and not very different from that found in a medium with its parent strain or in a medium containing no cells. (iii) EF260 cells were unable to produce gluconate from glucose via the PQQ/GCD pathway. (iv) Introduction of a gcd::Cm deletion in EF260, eliminating GCD, did not affect glucose metabolism. This suggested a pathway for glucose metabolism other than the PQQ/GCD pathway. (v) Glucose uptake and metabolism in EF260 involved a low-affinity transport system of unknown identity, followed most likely by phosphorylation via glucokinase. It is concluded that E. coli cannot synthesize PQQ and that it lacks genes required for PQQ biosynthesis.
Apoenzymes↗
In vitro selection of variants of herpes simplex virus type 1 which differ in cytopathic changes.
To analyze the mechanisms for in vitro emergence of the syncytial variants of herpes simplex virus type 1 (HSV-1), several cell lines were infected with a mixture of equal amounts of two HSV-1 variants, one syncytial and the other non-syncytial, and changes in their relative abundance were monitored during passage. With a combination of two variants of the Miyama strain of HSV-1, the syncytial variant became dominant during passage in Vero, RK-13 and FL cells. On the other hand, the ratios of the two variants remained around 1:1 during the passage in HEp-2, MGC and HEL cells. In another set of variants of the SKO strain of HSV-1, the outcomes were different from those of the Miyama strain in the FL, MGC and HEp-2 cells. The ratios of the two variants remained around 1:1 during passage in FL cells, while the non-syncytial variant became dominant during passage in MGC and HEp-2 cells. In addition, we examined the effects of a complement and interferon-beta (IFN-beta) on the outcome of the selection. As a result, the complement slowed the selection of a syncytial variant, whereas IFN-beta facilitated it.
Cell Line↗
Clinical and histological features of cytomegalovirus hepatitis in previously healthy adults.
It is well known that cytomegalovirus infection is often accompanied by hepatitis, but there have been few comparative studies with respect to clinical features of cytomegalovirus-associated hepatitis and other acute viral hepatitides. In the present study, clinical and pathological features of 11 acute sporadic cytomegalovirus hepatitis infections in previously healthy adults were compared with those of 45 acute sporadic viral hepatitis, including type A, type B and type C. As a result, the characteristics of cytomegalovirus hepatitis were a long-lasting fever, splenomegaly, atypical lymphocytosis, a mild transaminasemia, a low ratio of alanine aminotransferase level to lactate dehydrogenase level, and mild hepatic histopathological changes.
Acute Disease↗
[Diagnosis of neonatal enterovirus meningitis by reverse transcription-polymerase chain reaction].
We evaluated the potential clinical utility of a reverse transcription-polymerase chain reaction (RT-PCR) for neonatal enterovirus meningitis, comparing the results with viral culture and white blood cell (WBC) counts in the cerebrospinal fluid (CSF). Of the 41 cases of enteroviral infection, 31 cases (76%) were finally diagnosed as meningitis by either viral culture, CSF WBC count or RT-PCR. Of those with culture positive and negative, the RT-PCR positive rates were 10 (100%) and 6/13 (46%), respectively. Of those with and without WBC increase in the CSF, the RT-PCR positive rates were 18/20 (90%) and 5/14 (36%), respectively. There was one RT-PCR positive case (1/6, 17%) among those with culture negative and no WBC increase in the CSF. RT-PCR performed on CSF is a sensitive and specific method for the diagnosis of neonatal enterovirus meningitis.
Enterovirus Infections↗
Differences in sialic acid-galactose linkages in the chicken egg amnion and allantois influence human influenza virus receptor specificity and variant selection.
Human influenza viruses are more efficiently isolated by inoculating patient samples into the amniotic rather than the allantoic cavity of embryonated chicken eggs. This type of cultivation selects virus variants with mutations around the hemagglutinin (HA) receptor binding site. To understand the molecular basis of these phenomena, we investigated the abundances of sialic acid (SA) linked to galactose (Gal) by the alpha-2,3 linkage (SA alpha2,3Gal) and SA alpha2,6Gal in egg amniotic and allantoic cells and in Madin-Darby canine kidney (MDCK) cells. Using SA-Gal linkage-specific lectins (Maackia amurensis agglutinin specific for SA alpha2,6Gal and Sambucus nigra agglutinin specific for SA alpha2,3Gal), we found SA alpha2,3Gal in both allantoic and amniotic cells and SA alpha2,6Gal in only the amniotic cells. MDCK cells contained both linkages. To investigate how this difference in abundances of SA alpha2,3Gal and SA alpha2,6Gal in allantoic and amniotic cells affects the appearance of host cell variants in eggs, we determined the receptor specificities and HA amino acid sequences of two different patient viruses which were isolated and passaged in the amnion or in the allantois and which were compared with MDCK cell-grown viruses. We found that the viruses maintained high SA alpha2,6Gal specificities when grown in MDCK cells or following up to two amniotic passages; however, further passages in either the amnion or allantois resulted in the acquisition of, or a complete shift to, SA alpha2,3Gal specificity, depending on the virus strain. This change in receptor specificity was accompanied by the appearance of variants in the population with Leu-to-Gln mutations at position 226 in their HA. These findings suggest that lack of SA alpha2,6Gal linkages in the allantois of chicken eggs is a selective pressure for the appearance of host cell variants with altered receptor specificities and amino acid changes at position 226.
Allantois↗
Panencephalopathic type of Creutzfeldt-Jakob disease associated with cadaveric dura mater graft.
A 52 year old man with Creutzfeldt-Jakob disease who received a cadaveric dura mater graft 99 months before the onset is reported. The prion protein gene was homozygous for methionine at the polymorphic codon 129. Neuropathological examination disclosed a panencephalopathic type of Creutzfeldt-Jakob disease which was characterised by severe involvement of the cerebral white matter and cerebellum, as well as of the cerebral cortical and deep grey matter. Thus the panencephalopathic type of Creutzfeldt-Jakob disease may occur in association with cadaveric dura mater grafts.
Cadaver↗
Association of presenilin-1 polymorphism with cerebral amyloid angiopathy in the elderly.
BACKGROUND AND PURPOSE: An intronic polymorphism of presenilin-1 (PS-1), a gene responsible for early-onset familial Alzheimer's disease, has been reported to be associated with late-onset sporadic Alzheimer's disease. In a search for a genetic risk factor of sporadic cerebral amyloid angiopathy (CAA), we investigated the association of the polymorphism of PS-1 with CAA. METHODS: The association between the severity of CAA and genotypes of a polymorphism in intron 8 of PS-1 was investigated in 137 autopsy cases of the elderly. RESULTS: A significant decrease of PS-1 2/2 genotype frequency was associated with severe or moderate CAA. CONCLUSIONS: Our results suggest that PS-1 intronic polymorphism may be associated with the severity of CAA in the elderly.
Aged↗
Mutation analysis of five Japanese families with Wiskott-Aldrich syndrome and determination of the family members' carrier status using three different methods.
Mutation analysis for five families with Wiskottt-Aldrich syndrome was performed. The mutations found were two missense mutations, two one-base deletion mutations, and a large deletion mutation in the WASP gene. The three mutations had been reported before, but the remaining two were new. We used the mutation information to determine the carrier status of the female relatives of the patients. Three different approaches were taken depending on the type of mutation, and the carrier determination was successfully performed.
Adult↗
Expression of thyrotropin-releasing hormone (TRH) receptor mRNA in somatotrophs in the rat anterior pituitary.
A response of growth hormone (GH) to thyrotropin-releasing hormone (TRH) is observed in lower mammals and patients with diseases such as a cromegaly, but not in normal subjects. We have previously demonstrated the existence of intact TRH receptor mRNA in GH-secreting adenoma. To examine whether intact somatotrophs in the anterior pituitary also express TRH receptor, we attempted to localize both TRHR mRNA and GH immunoreactivity simultaneously. In situ hybridization analysis revealed TRHR mRNAs specifically in the anterior pituitary, and 61.1% of the anterior pituitary cells expressed this transcript. Staining for GH and PRL on the same samples showed that the somatotrophs apparently expressed TRHR mRNA and approximately 62.3% and 30.9% of hybridization-positive cells were somatotorophs and mammotrophs, respectively. Moreover, TRHR mRNA level in the somatotrophs expressed as the number of silver grains per cell was equivalent to that in the mammotrophs. These findings demonstrated expression of the TRHR mRNA in somatotrophs in the rat anterior pituitary, and also showed that more than 50% of the TRHR mRNA detected in the anterior pituitary was derived from these cells.
Animals↗
A novel transcript for the thyrotropin-releasing hormone receptor in human pituitary and pituitary tumors.
We measured the amounts of TRH receptor (TRHR) messenger ribonucleic acid (mRNA) in human normal pituitary and pituitary tumors and found a novel transcript of the TRHR gene. Competitive PCR revealed expression of the TRHR mRNA in all pituitary adenomas examined, and its level was variable and similar to that in the normal pituitary. When the C-terminal region was amplified by PCR, an additional short product was observed. Cloning and sequence analysis of this short fragment revealed that the deleted sequence corresponded exactly to the 5'-sequence of exon 3, indicating alternative splicing of the TRHR mRNA. This alternative splicing resulted in a frame shift, yielding a C-terminal truncated protein (HTRHR2) on translation. Expression analysis of HTRHR2 in Chinese hamster ovary cells showed no significant binding to [3HIMeTRH or response of intracellular calcium to TRH administration. However, the mRNA ratio of HTRHR2 vs. the wild type (HTRHR1) was significantly different among pituitary tumors. The highest ratio was observed in prolactinomas (30%), and almost no detectable expression was found in GH-producing tumors. These findings indicate that this novel transcript of the human TRH receptor gene is produced in a tumor-specific manner and may be a useful parameter for evaluation of individual pituitary tumors.
Adenoma↗