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H Kondoh

Publications and source records attributed to H Kondoh.

At least 109 records · Page 6Linked to original sources
PubMed1994

Lens-specific activity of the chicken delta 1-crystallin enhancer in the mouse.

A lens-specific enhancer was identified in the third intron of the chicken delta 1-crystallin gene by analysis based on transient transfection of primary-cultured cells. To assess the significance of this enhancer's activity in embryonic lens cells during development, tkCAT gene carrying the enhancer was introduced into mouse embryos utilizing ES (embryonic stem) cell-mediated gene transfer. In the undifferentiated culture condition, ES lines with enhancer-carrying tkCAT did not express any significant level of CAT (chloramphenicol acetyltransferase). However, when the ES cells were injected into a blastocyst and allowed to differentiate into various somatic cells of an embryo, CAT expression was observed exclusively in lens, and the expression was dependent upon the delta 1-crystallin enhancer. We concluded that the delta 1-crystallin enhancer alone is sufficient for eliciting lens-specific gene expression in developing mouse embryos and that the mechanism of lens-specific regulation effected by the delta 1-crystallin enhancer is conserved between the chicken and the mouse.

Animals↗
PubMed1993

A mouse homologue of the Drosophila tumour-suppressor gene l(2)gl controlled by Hox-C8 in vivo.

The homeobox is a 183-base-pair DNA sequence originally found in Drosophila segmentation and homeotic genes. In Drosophila, homeotic genes are clustered in the Antennapedia and Bithorax complexes, collectively called the homeotic gene complex (HOM-C). In the mouse genome, about 40 homeobox genes (Hox) are clustered in four chromosomal regions (Hox A to D). The Hox genes are arranged in the same order and have the same anteroposterior pattern of expression as their structural homologue in the HOM-C, suggesting that they control mouse pattern formation in the same way that HOM-C members do in Drosophila. Homeobox gene products are believed to be transcription factors that regulate expression of target genes. A few candidate target genes have been identified in Drosophila by various approaches but the Hox gene targets are poorly understood, mostly because of limitations in the available approaches. Here we identify several candidate Hox gene targets, including a mouse homologue of the Drosophila tumour-suppressor gene l(2)gl, by immunopurification of DNA sequences bound to a Hox protein in native chromatin.

Amino Acid Sequence↗
PubMed1993

Murine chromosomal location of four class III POU transcription factors.

A family of mouse genes encoding class III POU transcription factors consists of four members: Oct-6, Brn-2, Brn-1, and Brn-4. In accordance with mouse nomenclature, these loci have been designated Otf-6, Otf-7, Otf-8, and Otf-9, respectively. While the four genes share a highly conserved class III POU domain, the remaining regions are considerably diverged from each other. The POU domains of these transcription factors recognize the octamer-motif sequence and possess a similar DNA-binding specificity. Chromosomal mapping has demonstrated that the four genes are unlinked: Otf-6 is located on the distal region of chromosome 4, Otf-7 on the proximal region of chromosome 4, Otf-8 on chromosome 1, and Otf-9 on the X chromosome.

Animals↗
PubMed1993

Transition of localization of the N-Myc protein from nucleus to cytoplasm in differentiating neurons.

N-myc is a developmentally regulated proto-oncogene encoding a putative sequence-specific DNA-binding protein. Previous studies on tissue distribution of N-myc transcripts indicated that one of the major sites of N-myc expression is the CNS and neural crest derivatives in developing embryos. We investigated N-Myc protein expression in embryonic neural tissues and found that the protein was usually localized in the nucleus, but accumulated in the cytoplasm upon differentiation of specific classes of neurons, e.g., retinal ganglion cells, neurons of spinal ganglia, and Purkinje cells of the cerebellum. The change of localization of N-Myc from the nucleus to the cytoplasm indicates a novel feature of regulation of myc family proteins and suggests functions of N-myc in the cytoplasm of maturing neurons.

Amino Acid Sequence↗
PubMed1993

Overlapping positive and negative regulatory elements determine lens-specific activity of the delta 1-crystallin enhancer.

Lens-specific expression of the delta 1-crystallin gene is governed by an enhancer in the third intron, and the 30-bp-long DC5 fragment was found to be responsible for eliciting the lens-specific activity. Mutational analysis of the DC5 fragment identified two contiguous, interdependent positive elements and a negative element which overlaps the 3'-located positive element. Previously identified ubiquitous factors delta EF1 bound to the negative element and repressed the enhancer activity in nonlens cells. Mutation and cotransfection analyses indicated the existence of an activator which counteracts the action of delta EF1 in lens cells, probably through binding site competition. We also found a group of nuclear factors, collectively called delta EF2, which bound to the 5'-located positive element. delta EF2a and -b were the major species in lens cells, whereas delta EF2c and -d predominated in nonlens cells. These delta EF2 proteins probably cooperate with factors bound to the 3'-located element in activation in lens cells and repression in nonlens cells. delta EF2 proteins also bound to a promoter sequence of the gamma F-crystallin gene, suggesting that delta EF2 proteins are involved in lens-specific regulation of various crystallin classes.

Animals↗
PubMed1993

Relationship between vitamin K dependent coagulation factors and anticoagulants (protein C and protein S) in neonatal vitamin K deficiency.

To determine the relationship between vitamin K dependent coagulation factors and natural anticoagulants, namely protein C and protein S, in various degrees of vitamin K deficiency, plasma values for clotting activity, protein induced by vitamin K absence (PIVKA-II), protein C antigen, gamma-carboxy protein C antigen, and protein S antigen including total and free fractions and activity of protein C were measured in 66 full term and healthy breast fed neonates who did not receive vitamin K supplement at birth. The 66 neonates were divided into a control group (17 cases) and a low group (49 cases) according to their values for clotting activity--that is, > or = 20% or < 20% during the first six days of life--and vitamin K was immediately given when the neonates showed values < 20%. In the low group clotting activity gamma-carboxy protein C, free protein S, and protein C activity was significantly decreased to a minimum on day 2 or 3, and increased in parallel after vitamin K administration. Furthermore, they were positively correlated with one another and inversely cor-correlated with the PIVKA-II concentrations. These findings suggest that simultaneous gamma-carboxylation of coagulation factors and proteins C and S acts to maintain both coagulation and anticoagulation activities in parallel at various concentrations of vitamin K. The breast milk intake in the group with low values of clotting activity was significantly lower than that in the control group during the first three days of life.(ABSTRACT TRUNCATED AT 250 WORDS)

Biomarkers↗
PubMed1993

Interpretation of subtle interstitial lung abnormalities: conventional versus storage phosphor radiography.

To evaluate the reliability of storage phosphor radiography (SR) in diagnosis of subtle interstitial lung abnormalities, the differences among radiologists in interpreting conventional screen-film radiographs and full-size and minified SR images obtained in 80 patients were studied. Forty patients had subtle interstitial lung abnormalities and 40 had no lung abnormalities. Seven chest radiologists and seven residents evaluated the images by using a five-point presence of abnormality scale. Results were evaluated with receiver operating characteristic technique. For all observers, no significant differences were observed among the three image types. For the chest radiologists, significant differences were observed between conventional radiographs and the two SR formats (P < .01). Furthermore, perceptual accuracy was best with conventional radiographs evaluated by chest radiologists. Overall performance with SR and conventional radiography was identical for diagnosis of abnormalities, but detection performance was significantly dependent on observer experience (P < .01 for chest radiologists and P > .01 for residents). For chest radiologists, critically important information may be lost with commercially available SR.

Adolescent↗
PubMed1993

Focal organizing pneumonia: CT appearance.

PURPOSE: To clarify the computed tomographic (CT) features of focal organizing pneumonia. MATERIALS AND METHODS: The authors retrospectively studied CT scans of 18 patients with histologically proved focal organizing pneumonia. Chest radiographs in all 18 patients suggested bronchogenic carcinoma. RESULTS: Seventeen of the 18 lesions (94%) had an irregular margin, 10 (56%) had satellite lesions, nine (50%) had a pleural tag, and nine (50%) had an air bronchogram. The pneumonia could be classified into three types: Type A (n = 5) was a small round mass (pleural tag, n = 4). Type B (n = 7) was an oval mass with broad contact with the pleura (satellite lesions and convergence of peripheral vessels, n = 6). Type C (n = 6) was an oval mass along the bronchovascular bundle (satellite lesions, n = 3; pleural tag, n = 4). CONCLUSION: The CT features of focal organizing pneumonia show wide variation, and some type B and C lesions are suggestive of benign lesions. However, other lesions may be difficult to differentiate from bronchogenic carcinoma even with CT.

Adult↗
PubMed1993

Defects of embryonic organogenesis resulting from targeted disruption of the N-myc gene in the mouse.

The highest expression of the N-myc gene occurs during embryonic organogenesis in the mouse ontogeny, with the peak of expression around embryonic day 9.5. Homozygous N-myc-deficient mice, produced by germline transmission of a disrupted allele in ES cells, developed normally to day 10.5, indicating dispensability of N-myc expression in the earlier period, but later accumulated organogenic abnormalities and died around day 11.5. The most notable abnormalities were found in the limb bud, visceral organs (lung, stomach, liver and heart) and the central/peripheral nervous systems, and were highly correlated with the site of N-myc expression. The limb buds and the lungs excised from N-myc-deficient mutant embryos were placed in culture to allow their development to stages beyond the point of death of the embryos. Analyses indicated that the mutant limbs failed to develop distal structures and the development of bronchi from the trachea was defective in the lungs. The latter defect was largely corrected by addition of fetal calf serum to the culture medium, suggesting that an activity missing in the mutant lung was replenished by a component of the serum. The phenotype of N-myc-deficient mutant embryos indicated requirement of the N-myc function in many instances of tissue interactions in organogenesis and also in cell-autonomous regulation of tissue maturation.

Animals↗
PubMed1993

Delta-crystallin enhancer binding protein delta EF1 is a zinc finger-homeodomain protein implicated in postgastrulation embryogenesis.

We investigated nuclear factors that bind to delta 1-crystallin enhancer core and regulate lens-specific transcription. A nuclear factor delta EF1, which binds to the essential element of the delta 1-crystallin enhancer core, was molecularly cloned from the chicken by a southwestern method. The protein organization of delta EF1 deduced from the cDNA sequence indicated that it has heterogeneous domains for DNA-binding, two widely separated zinc fingers and a homeodomain, analogous to Drosophila ZFH-1 protein. The C-terminal zinc fingers were found to be responsible for binding to the delta 1-crystallin enhancer core sequence. delta EF1 had proline-rich and acidic domains common to various transcriptional activators. During embryogenesis, delta EF1 expression was observed in the postgastrulation period in mesodermal tissues; initially, in the notochord, followed by somites, nephrotomes and other components. The expression level changed dynamically in a tissue, possibly reflecting the differentiation states of the constituent cells. Besides mesoderm, delta EF1 was expressed in the nervous system and the lens, but other ectodermal tissues and endoderm remained very low in delta EF1 expression. Cotransfection experiments indicated that this factor acts as a repressor of delta 1-crystallin enhancer. Possession of heterogeneous DNA-binding domains and its dynamic change of expression in embryogenesis strongly suggest that delta EF1 acts in multiple ways depending on the cell type and the gene under its regulation.

Amino Acid Sequence↗
PubMed1993

Diagnosis of coronoid process hyperplasia by three-dimensional computed tomographic imaging.

Three-dimensional (3D) CT imaging was performed on three cases (one unilateral, two bilateral) of coronoid process hyperplasia. This technique displayed the impingement of the enlarged coronoid process on an exostosis on the lower border of the malar bone. In addition, a small concavity was found on the inner surface of the malar bone that was not displayed by other imaging modalities. The 3D images were useful in planning surgical treatment. In cases of limitation of opening, finding a malar exostosis on conventional radiographs such as a Water's view should suggest the presence of coronoid process hyperplasia even if the impingement cannot be demonstrated.

Adult↗
PubMed1993

Staining senile plaques using Bodian's method modified with methenamine.

A new method is presented for staining various types of senile plaques isolated from the brains of patients with Alzheimer type dementia and related diseases in paraffin embedded sections using a modified Bodian's method with methenamine. This methenamine-Bodian method made it possible to observe diffuse plaques and other amyloid deposits which are barely detected by Bodian's original method. The staining of senile plaques by the method presented here was comparable to that of immunostaining with anti-beta-protein. The new method also stained neurofibrillary tangles. Therefore, the methenamine-Bodian method could be widely used for the detection of senile changes in paraffin embedded sections from autopsied human brains.

Aged↗
PubMed1993

[Standardization in hematology and the use of the data in clinical laboratories].

Recently developed automated blood cell counters provide accurate and precise data on complete blood count (CBC). The results of nationwide surveys obtained using them are usually better than those obtained by biochemical tests. The precision of CBC counting has been improved owing to the efforts of laboratories and manufacturers. As for hemoglobinometry, the cyanmethemoglobin and oxyhemoglobin methods used in blood cell counters gave different results for fresh and artificial blood in control surveys. Now instead of the oxyhemoglobin method, the sodium lauryl sulfate-hemoglobin method is used to minimize the variation among different counters. The biggest problem at present is the lack of control blood which can be used for any blood cell counter. Another problem is the laboratory report sent to clinicians, which gives only numerical data. However, other comments and normal reference values should also be presented. Sufficient care may not be taken for normal reference values; they vary considerably among different laboratories. Also, most laboratories and manufacturers now use various conventional units for CBC, but the SI unit should be used for comparison of the data. In conclusion, nationwide unification of CBC values should be established in the near future with cooperative efforts by laboratories and manufacturers.

Blood Cell Count↗
PubMed1992

[Cefepime (diHCl/L-arginine blend): intravenous continuous infusion and/or single dose subcutaneous toxicity study in rats and dogs].

To investigate single dose toxicity of cefepime (CFPM diHCl/L-arginine blend), the test drug was administered to rats [Crj: CD (SD)] of both sexes at dose levels of 500, 1,000 and 2,000 mg/kg using intravenous continuous infusion or subcutaneous injection, and to male beagle dogs at 1,000 and 2,000 mg/kg using intravenous continuous infusion. As the control, two additional groups of each animals were given either saline or L-arginine alone which was used in the test formulation to adjust pH values of CFPM diHCl solutions. The obtained results are summarized as follows: 1. Rats dosed with 2,000 mg/kg CFPM through intravenous continuous infusion showed slightly decreased spontaneous physical activity. One male rat dosed with L-arginine alone via continuous infusion also showed slightly decreased activity. Slight to severe inflammatory reactions at injection sites including sloughing of the tail were prominent at doses of 1,000 or 2,000 mg/kg of CFPM, or L-arginine alone. Average body weights of rats in the test groups of either sex were comparable to the controls in all of the dose groups of the same sex during the 14-day test period. 2. Rats receiving 2,000 mg/kg CFPM in single subcutaneous injection showed slightly diminished activities. Slight to moderate reactions occurred around the injection site (viz., hardening, depilation, scab-formation and necrosis) in rats injected any of the 3 doses of CFPM. Though body weight gains were slightly retarded in male rats receiving 2,000 mg/kg CFPM during the last half of the observation period, such weight gain retardation was not observed in rats of other dose groups.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1992

[Cefepime (BMY-28142 diHCl/L-arginine blend): one-month repeated dose subcutaneous toxicity study in rats].

In order to investigate the toxicity of cefepime (CFPM, BMY-28142 diHCl/L-arginine blend upon repeated subcutaneous dosing), the test article was administered to Crj:CD(SD) rats of both sexes at daily dose levels of 150 (low dose), 500 (intermediate dose) and 1,500 (high dose) mg/kg/day by subcutaneous route for 28 days. Two additional groups of rats were given either saline (negative control) or L-arginine (vehicle control). Doses were equally divided and administered twice each day with an interval of approximately 5 hours between the 2 doses of a same day. A half of rats in negative control and high dose groups were retained for examination during one-month recovery period. The results obtained are summarized as follows: 1. Upon general observations, it was found that drug-related changes were restricted to the injection sites. Depilation and scab-formation of the injection sites were noted in high dose rats of both sexes and intermediate dose females. No deaths occurred during the study. 2. Slightly depressed body weight gains were observed for high dose males during the latter part of the dosing period. 3. Slightly lower food consumptions were noted for intermediate and high dose males at Week 1. 4. Slightly higher water consumptions were generally detected for high dose rats during the dosing period. 5. Hematological examinations revealed that a slight decrease in the average value of relative lymphocyte counts and a slight increase in the average value of relative segmented neutrophil counts were evident for high dose males. These findings might be attributable to the inflammatory reactions at the injection sites.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1991

Identification of nuclear factor delta EF1 and its binding site essential for lens-specific activity of the delta 1-crystallin enhancer.

The lens-specific reglatory element of the delta 1-crystallin enhancer lies within the core segment (Goto et al., (1990) Mol. Cell. Biol. 10, 935-964). The element was allocated within the 55 bp long HN fragment of the core. Block-wise base substitutions were introduced to the 55 bp and their effect on the enhancer activity of the multimers in lens cells was examined. By base sequence alteration of either of the contiguous blocks 5 and 6, with their original sequence of TTGCT and CACCT, respectively, enhancer activity was totally lost. A lens nuclear factor delta EF1 was found which bound specifically to the base sequences defined by the blocks. DNA binding activity very similar to delta EF1 was also found in extracts of tissues other than lens, suggesting that delta EF1 participates in lens-specific regulation through tissue-dependent modification or interaction with other factors.

Animals↗