Procedures for processing the rabbit primary vitreous for studies with transmission and scanning electron microscopy.
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Biomedical subjects
Publications and source records attributed to I Watanabe.
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We present here the first report of a transformation system developed for the filamentous, ML-236B (compactin)-producing fungus Penicillium citrinum. Hygromycin B-resistant colonies were obtained after treatment of protoplasts with a vector containing an Escherichia coli hygromycin B phosphotransferase gene fused to a 3-phosphoglycerate kinase promoter from Aspergillus nidulans. The transformation rate was 194 transformants per microgram circular DNA per 4 x 10(5) viable protoplasts under optimized transformation conditions. Transformation took place via the integration of plasmid DNA into the fungal chromosomal DNA. Most of the integration events appeared to produce tandemly iterated arrays of plasmid molecules at different sites in the chromosome. The transformed, drug-resistant, phenotype and the integrated plasmids were mitotically stable with or without selection in a majority of cases. The demonstration of such a transformation system is an essential first step in the application of recombinant DNA technology to strain improvement and for the production of novel ML-236B derivatives.
The gene coding for 3-phosphoglycerate kinase (PGK) in ML-236B (compactin)-producing Penicillium citrinum was isolated from the recombinant phage lambda library using the corresponding Aspergillus nidulans pgk gene as a probe. The P. citrinum pgk gene has an open reading frame of 1,254 bp, encoding a protein of 417 amino acids with a predicted molecular weight of 44,079 daltons. The position of the two introns, 59 and 60 bp respectively, was deduced from an homology comparison with the sequence of the A. nidulans pgk gene. The PGK protein of P. citrinum shows extensive high homology to the PGKs of four other fungi: P. chrysogenum (93%), A. nidulans (84%), Trichoderma reesei (78%) and Saccharomyces cerevisiae (68%). Almost total conservation is found in P. citrinum of residues thought to be important for the structure and function of the yeast enzyme. The strong codon preference found has greater similarity to that in other filamentous fungi than in yeast. A DNA fragment encompassing the pgk gene was shown to hybridize a 1.35-kb poly(A)+RNA, sufficient to encode the PGK polypeptide. A fused gene, pgk-hpt, containing the putative pgk promoter and the open reading frame of the Escherichia coli hygromycin B phosphotransferase (hpt) gene was constructed, and was successfully used to transform P. citrinum to a hygromycin B (HmB)-resistant phenotype.
An unusual form of scotopic electroretinogram with a bright white stimulus, which consisted of a rectangular a-wave of normal amplitude and a b-wave of supernormal amplitude, was recorded in three patients with cone dysfunction. In addition to poor visual acuity, abnormal color vision and reduced amplitude of the photopic electroretinogram, these patients showed a 2-log unit elevation of the dark-adaptation threshold. Funduscopic examination and fluorescein angiography revealed fine granular pigment disturbances at the macula. The relationship between the response of the dark-adapted electroretinogram versus stimulus intensity was unique to these patients. The b-wave thresholds were elevated by 1 log unit. The b-waves were reduced in amplitude and markedly delayed in implicit time to dim stimuli, but supernormal in amplitude and normal in implicit time to bright stimuli.
A full-length cDNA clone, BHL4-1, encoding factor B was isolated from a human liver cDNA library and sequenced in its entirety. It consists of 2388 bp which include a 5'-untranslated region of 40 bp, a single open reading frame, 2292 bp in length, and a 3'-untranslated region of 56 bp followed by a poly-A tail. The deduced amino acid sequence comprises 25 residues of a putative leader peptide and 739 residues of the mature polypeptide chain of the F allele of factor B. We constructed an S allele-like Q7R mutant of BHL4-1 by site-directed mutagenesis. Both the wild-type and mutant factor B cDNA were expressed transiently in a eukaryotic system. The specific hemolytic activities of the two recombinant factor B alleles and of native B were not significantly different from each other.
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The production of (R)-3-chloro-1,2-propanediol [(R)-MCP] from prochiral 1,3-dichloro-2-propanol (DCP) was examined with a bacterial strain identified as a Corynebacterium strain. The addition of glycerol as a carbon source or some chlorinated alcohols to a medium was effective for the induction of activity catalyzing the transformation of DCP into MCP. The optimum pH for (R)-MCP production by the resting cell reaction was around 8.0. The optical purity of (R)-MCP formed was improved by keeping the level of DCP in the reaction mixture at a low concentration. (R)-MCP was obtained from 77.5 mM DCP with a 97.3% molar conversion yield and an 83.8% enantiomeric excess of its optical purity by periodic feeding of the substrate.
The polymerase chain reaction was used to amplify random sequences of DNA from 25 accessions of Azolla to evaluate the usefulness of this technique for identification and phylogenetic analysis of this aquatic fern. Accessions were selected to represent all known species within the genus Azolla and to encompass the world-wide distribution of the fern. Primers of 10 nucleotides with 70% G + C content were used to generate randomly amplified polymorphic DNA from the symbiotic Azolla-Anabaena complex. Twenty-two primers were used and each primer gave 4-10 bands of different molecular weights for each accession. Bands were scored as present or absent for each accession and variation among accessions was quantified using Nei's genetic distances. A dendrogram summarizing phenetic relationships among the 25 accessions was generated using the unweighted pair-group method with arithmetic mean. Principal component analysis was also used to evaluate genetic similarities. Three distinct groups were identified: group 1 contains five species, group 2 contains the pinnata species, and group 3 contains the nilotica species. The analysis demonstrates that the major groups of Azolla species can be easily distinguished from one an other and, in addition, that closely related accessions within species can be identified. We further found that using 10 primers, a phylogeny that is essentially the same as that derived from 22 primers can be constructed. Our results suggest that total DNA extracted from the Azolla-Anabaena symbionts is useful for classification and phylogenetic studies of Azolla.
The relationship between the time required for reperfusion and the incidence of late potentials was studied in 94 patients who survived a first acute myocardial infarction (AMI) and who showed total occlusion of the infarct-related artery at an initial coronary arteriography. Sixty-three patients who successfully underwent direct percutaneous transluminal coronary angioplasty (PTCA), and 31 who were treated conventionally (controls), underwent signal-averaged electrocardiography. Direct PTCA patients were classified into 5 groups according to the time required for reperfusion: < or = 4, 4-6, 6-8, 8-10, and > or = 10 h. The incidence of late potentials in these groups was 8%, 12%, 14%, 33%, and 43%, respectively, and 48% in the controls. Late potentials were recorded more frequently as the period until successful reperfusion increased: the incidence of late potentials was significantly lower in the < or = 4 and 4-6 h groups than in the controls (p < 0.005 and p < 0.05, respectively). Therefore, reperfusion achieved within 6 h reduced the incidence of late potentials in AMI patients and may be effective for preventing malignant ventricular arrhythmias.
In order to investigate the genetic background of Menière's disease, histocompatibility (HLA) antigens in Japanese patients were studied. HLA-class I: HLA-A, -B and -C were typed by the classical microcytotoxicity technique, and HLA-class II: HLA-DR, DQ, and DP were typed by PCR-DNA typing methods. Twenty patient samples tested were selected very strictly following clinical data and classical criteria. Most of the patients had been suffering from typical symptoms during a considerably long period of time (16 +/- 7 years). Normal controls were based on the gene frequency in the Japanese population. Compared with the normal controls, a higher frequency of the DRB1*1602 subtype of HLA-DR2 was found in the patient group (chi 2 = 9,21, p < 0.04). P-values were corrected by multiplying by the total number of antigens. Additionally, HLA-Cw4 was increased, although the p-value was not significant after multiple antigen correction. There was no obvious relationship between the HLA-DRB1*1602 patients and the clinical data that included severity, age at time of onset, etc.
We describe 3 cases of systemic lupus erythematosus (SLE) associated with anti-Scl-70 antibody. Common symptoms were central nervous system disorder, discoid rash, lymphadenopathy, and no renal disorder. Two of 3 cases showed some symptoms of scleroderma but could not be diagnosed as such. Although further followup is required to determine if scleroderma develops, these unique symptoms might be a subtype of SLE or a lupus-like syndrome characterized by symptoms and anti-Scl-70 antibody.
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The long-term durability of a photocured resin bond to ground bovine dentin with its smear layer retained was investigated. The bonding resin that was employed was composed of 5.0 wt% 2-(methacryloxy)ethyl phenyl hydrogen phosphate (phenyl-P) as a diffusion-promoting monomer, 0.5 wt% camphorquinone as a photosensitizer, and 0.5 wt% N-phenylglycine as a reducing agent in triethyleneglycol dimethacrylate. Following polymerization of the bonding resin, a composite resin was placed and photocured for 60 seconds. Prepared specimens were stored in 37 degrees C water for 1 day, 6 months, and 1 year. Measured tensile bond strengths were 6.7 MPa after 1 day of storage, 4.1 MPa after 6 months of storage, and 2.8 mPa after 1 year of storage. Examinations of the interfaces after fracture under tensile loading suggested that long-term water-immersion weakened the bonds between the photocured adhesive resin and the smear layer-retained dentin because there was insufficient diffusion of the adhesive resin through the retained smear layer.
We report a case of 33-year-old man with multiple sclerosis, showing piano playing movement in both hands. His course of multiple sclerosis was remittent/progressive during 2 years and the clinical manifestation suggested the spinal cord involvement. On July 15, 1991, he was admitted with numbness of the right limbs, and then developed piano playing movement in both hands, more marked in the right side. Neurological examination revealed mild weakness in the right upper extremity, and rough touch, pain, and temperature sensation were slightly decreased. However, there was no deep sensory abnormalities, such as vibration, fine touch, and position senses. Vibration sense was lost below ilium. CSF examination showed elevation of IgG index (1.6), three oligoclonal bands and myelin basic protein content of 2.4 ng/ml. There was no HTLV-I antibody in CSF. SSEP, elicited by median nerve stimulation at the right wrist, showed no N13 and low amplitude of N20. T2-weighted images of cervical MRI revealed area of high signal intensity at the C3-C4 level. The piano playing movement gradually improved and disappeared by the initiation of steroid hormone therapy. It was considered that involuntary movement in this patient was due to the spinal cord lesion caused by multiple sclerosis. These findings suggested that the involuntary movement like pseudoathetosis could present without deep sensory abnormalities.
We have experienced two cases of anaphylactoid reactions following intravenous methylprednisolone sodium succinate administration. They had neither asthmatic nor other allergic histories. The first case was a 45-yr-old man. In addition to the antigenicity of hydrocortisone itself, it is suggested that administration speed was so fast that its side effects were intensified. The second case was a 10-yr old girl. Succinate ester was thought to be the cause of her allergic reaction (urticaria). It is also possible that her hypersensitivity to steroids was dose-dependent.
The Aulhorn flicker test measures the subjective brightness of various frequencies of flickering light. We modified an Aulhorn flicker test with light emitting diode (LED) and the results of 21 normal eyes and 18 affected eyes (7 eyes with idiopathic optic neuritis, one eye with rhinogenous optic neuropathy (ethmoid sinus mucocele), two eyes with preoperative pituitary tumor, one eye with empty sella, one eye with anterior ischemic optic neuropathy, one eye with syphilitic optic neuritis, five eyes with primary open angle glaucoma) were presented. All normal eyes showed the Brücke-Bartley effect which refers to an enhanced subjective brightness at lower frequencies. Six eyes with idiopathic optic neuritis and one eye with rhinogenous optic neuropathy in the acute stage demonstrated the Aulhorn effect which refers to a reduced subjective brightness at lower frequencies. Four eyes with the Aulhorn effect that were followed up showed less prominent Aulhorn effect. One eye with idiopathic optic neuritis and 10 eyes with other conditions did not show the Aulhorn effect. It was suggested that the modified Aulhorn flicker test with LED is a useful method for diagnosis of optic neuritis in the acute stage.
A 34-year-old woman showed a partially pigmented, greyish-white mass at a position of 1 o'clock behind the iris of her left eye. The lens equator was compressed and focal opacity had developed. The adjacent ciliary processes and zonules were intact. Photocoagulation was not effective and dense cataract gradually developed, so we performed extracapsular cataract extraction and partial iridocyclectomy. The tumor was nonencapsulated, nodular and myxomatous in appearance, arising from the pars plicata. Histological examinations revealed that the tumor was composed of nonpigmented cells and a small number of pigmented cell clusters. The cells were arranged like cords or gland-like structure with intervening myxomatous, fibrillar, and partially hyalinous interstitium. There was no finding of malignancy. The tumor showed similar microscopic structure and findings of mucous stains of normal ciliary nonpigmented epithelium and internal basement membrane, so a diagnosis of benign epithelioma was made.
Serotonin (5-hydroxytryptamine, 5HT) is believed to play a role in vasospasm and increased platelet aggregability that in turn could contribute to atherosclerosis. The present study was designed to evaluate a possible participation of serotonin in the development of vascular complications in diabetes mellitus. Whole blood and plasma serotonin, the platelet uptake and release of the amine and serotonin- induced platelet aggregation were studied in 32 patients with Type 2 diabetes. The patients were divided into three groups according to the presence and advancement of retinopathy. Mean levels of blood serotonin content were significantly lower in diabetic patients. The concentration of the amine in the plasma was markedly increased in diabetes. It was correlated with vascular changes of the retina. We established that platelets from diabetic patients took up less serotonin when compared to the control group. Concomitantly enhanced spontaneous release of 5HT from platelets was observed. The platelets of diabetic patients showed increased response to serotonin. There was a relation between serotonin-induced aggregation and the presence of retinopathy. These results suggest that serotonin may be involved in the pathogenesis of diabetic vasculopathy.