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Biomedical subjects

H Tada

Publications and source records attributed to H Tada.

At least 343 records · Page 19Linked to original sources

[A patient with alternating hemiplegia in childhood].

Alternating hemiplegia in childhood (Verret, 1971) is a disorder presenting with frequent episodes of alternating hemiplegia from early infancy. We report a patient with this disorder, along with a pathophysiological study and a discussion about the available therapies for this disorder. The patient, an 11-year-old boy, visited our hospital with episodes of alternating hemiplegia from early infancy. His family history showed that many members suffered from migraine. He was born with asphyxia. Mental and motor developmental delays were seen from early infancy. The hemiplegic episodes with ipsilateral facial palsy had occurred frequently from early infancy. The episodes were frequently induced by emotional stress. The duration of hemiplegia varied from 10 minutes to 3 days. From the age of 11 years, he had begun to have migrainous attacks with or without hemiplegic episodes. Neurological examination revealed slight muscle hypotonia, choreoathetosis and dystonic movements induced by locomotion, positive Myerson sign, increased deep tendon reflexes and Babinski reflex. CAG, VAG and CAT revealed normal findings. EEG revealed diffuse generalized slowing during hemiplegic episodes. Measurement of regional cerebral blood flow (CBF) by 133Xe inhalation method revealed a slight decrease of bilateral CBF during a quadriplegic episode. Positron emission tomography using C15O2 revealed a slight decrease of CBF at the insula, putamen and claustrum of the left side during a right sided episode. Increased excretion of urinary 5-HIAA was seen during one episode. From our clinical and laboratory findings, we think this disorder may be a special type of migraine. Therapeutic trials of diazepam and flunarizine were both effective, but the initial effectiveness was decreased after 5 months.

Age Factors↗

Piston-pump-type high frequency oscillatory ventilation for neonates with congenital diaphragmatic hernia: a new protocol.

High frequency ventilation and extracorporeal membrane oxygenation (ECMO) are devices that are expected to save the lives of newborn infants whose pulmonary conditions have deteriorated. A piston-pump-type high-frequency oscillator (HFO), developed by Bryan and Miyasaka called "Hummingbird," is considered to be superior to high frequency "jet" ventilators or those of the flow-interrupter type, and was used successfully in two neonates with congenital diaphragmatic hernia (CDH) in a high-risk group. The first baby was on a conventional ventilator with pharmacologic support for the first 54 hours and then operated on. Postoperative deterioration necessitated the use of HFO for the next eight days. The infant then recovered uneventfully. For the second baby, HFO was necessary both preoperatively and postoperatively. This baby had a major diaphragmatic defect and her case was complicated with pneumothorax. There was a long stormy course on HFO (total, 70 days), but the patient was successfully extubated on the 75th day postoperatively and is now doing well. We believe active long preoperative stabilization with pharmacologic support and preoperative and postoperative hyperventilation with a piston-pump-type HFO may be a new innovative strategy for the management of severe CDH patients.

Female↗

Construction of a "mutagenesis cartridge" for poliovirus genome-linked viral protein: isolation and characterization of viable and nonviable mutants.

By following a strategy of genetic analysis of poliovirus, we have constructed a synthetic "mutagenesis cartridge" spanning the genome-linked viral protein coding region and flanking cleavage sites in an infectious cDNA clone of the type 1 (Mahoney) genome. The insertion of new restriction sites within the infectious clone has allowed us to replace the wild-type sequences with short complementary pairs of synthetic oligonucleotides containing various mutations. A set of mutations have been made that create methionine codons within the genome-linked viral protein region. The resulting viruses have growth characteristics similar to wild type. Experiments that led to an alteration of the tyrosine residue responsible for the linkage to RNA have resulted in nonviable virus. In one mutant, proteolytic processing assayed in vitro appeared unimpaired by the mutation. We suggest that the position of the tyrosine residue is important for genome-linked viral protein function(s).

Cloning, Molecular↗

Mutational analysis of the genome-linked protein VPg of poliovirus.

Using a mutagenesis cartridge (R. J. Kuhn, H. Tada, M. F. Ypma-Wong, J. J. Dunn, B. L. Semler, and E. Wimmer, Proc. Natl. Acad. Sci. USA 85:519-523, 1988), we have generated single and multiple amino acid replacement mutants, as well as a single amino acid insertion mutant in the genome-linked protein VPg of poliovirus. Moreover, we constructed three different 5-amino-acid insertion mutants that map close to the C terminus of 3A, a viral polypeptide whose coding sequence is adjacent to VPg. Transfection of HeLa cells with RNA synthesized in vitro was used to test the effect of the mutation on viral proliferation. Mutations were either lethal or nonlethal. A temperature-sensitive phenotype was not observed. The arginine at position 17 of VPg could not be exchanged with any other amino acid without loss of viability, whereas the lysine at position 20, an amino acid conserved among all known polioviruses, coxsackieviruses, and echoviruses, was replaceable with several neutral amino acids and even with glutamic acid. Replacement of poliovirus VPg with echovirus 9 VPg yielded viable virus with impaired growth properties. Our results suggest considerable flexibility in the amino acid sequence of a functional VPg. All insertions in polypeptide 3A proved to be lethal. In vitro translation of mutated viral RNAs gave patterns of proteolytic processing that in some cases was aberrant, even though the mutation was nonlethal.

Amino Acid Sequence↗

Torn acetabular labrum in young patients. Arthroscopic diagnosis and management.

Arthroscopy of the hip revealed a torn acetabular labrum in seven young patients. Three of them had had an acute onset of symptoms during sporting activities. On examination all seven patients had pain on passive flexion and medial rotation of the joint. All but one of the tears were located on the posterosuperior portion of the labrum, and, in the acute cases, vascular dilatation around the tear was observed. In these cases, repeated arthroscopy several months later showed that the vascular changes had disappeared, but the tear was still present. The aetiology, diagnosis and treatment of the torn acetabular labrum are discussed.

Acetabulum↗

Non-Hodgkin's lymphoma of the pleural cavity developing from long-standing pyothorax.

Malignant lymphomas developing in tissue affected by a long-standing severe inflammatory process of nonautoimmune nature are presented. Two men and a woman aged 50, 58, and 73 years, were admitted after 22 to 30 year histories of pyothorax resulting from artificial pneumothorax for the treatment of pulmonary tuberculosis or tuberculous pleuritis. The diagnoses at admission were chronic pyothorax associated with a lung mass. Microscopically, tumors diffusely or locally proliferated with thickened pleura were present. A histologic examination showed that all the tumors were diffuse non-Hodgkin's lymphomas (NHL) of immunoblastic type with (one case) or without (two cases) plasmacytoid differentiation. Immunohistochemistry on paraffin sections revealed restricted expression of immunoglobulin light chains in one case showing plasmacytoid differentiation. A review of the literature showed that malignant lymphomas of this type have been reported exclusively from Japan but never from Western countries.

Aged↗

A case of Shwachman syndrome with increased spontaneous chromosome breakage.

In a patient with Shwachman syndrome, a high incidence of chromosome breakage was found. Chromosome studies done on three occasions on the patient's PHA-stimulated peripheral blood lymphocytes showed elevated frequencies of spontaneous chromosome aberrations compared with those in normal individuals. The patient's lymphocytes did not show increased sensitivity to mitomycin C.

Bone Marrow Diseases↗

The entire nucleotide sequence of the genome of human hepatitis A virus (isolate MBB).

Hepatitis A virus (HAV) is an important human pathogen causing hepatitis, with high incidence in developed as well as in developing countries. No vaccines are available. In order to determine the primary structure of the HAV genome, we have prepared cDNAs from viral RNA and cloned these into plasmid pBR322. These clones were used to determine the entire nucleotide sequence of the HAV RNA by rapid sequencing methods. We have compared this sequence of 7470 bases to known partial sequences, and one complete sequence of HAV RNA which were obtained recently from different strains of HAV. It is hoped that a comparison of sequence data from different isolates will help in the elucidation of the unusual growth pattern of HAV. In addition, it might provide helpful information about the immunological determinants that elicit the antibody response to infection.

Amino Acid Sequence↗

The effect of glycemic control on plasma soluble fibrin monomer complexes and fibronectin in diabetic patients.

We have shown previously that increased concentrations of plasma soluble fibrin monomer complexes (SFMC) and elevated fibronectin (Fn) levels are closely related to the development of diabetic microangiopathy. The purpose of the present study was to explore whether or not changes in plasma glucose levels could have an effect on these protein constituents. Plasma glucose levels of 25 uncontrolled diabetic patients were brought under control with insulin and serial measurements of SFMC and Fn were made over a period of 4 weeks. Glucose values fell from an average of 312 mg/100 ml to 160 mg/100 ml. Ten patients with macroproteinuria (i.e. greater than or equal to 0.5 g/24 hr) showed initially elevated plasma SFMC and Fn concentrations. These levels fell significantly over the 4 week observation period: from 13.6 mg/100 ml to 9.4 mg/100 ml for SFMC and from 38.4 mg/100 ml to 34.5 mg/100 ml for Fn. The remaining 15 patients had nearly normal levels of both SFMC (7.9 mg/100 ml) and Fn (31.1 mg/100 ml) and glycemic control brought no further reduction. The data indicated that a) elevated SFMC and Fn levels are indeed associated with diabetic microangiopathy, especially in the presence of macroproteinuria; and b) adequate glycemic control is capable of normalizing the plasma concentration of these constituents.

Adult↗

Examination by ultrasound of Legg-Calvé-Perthes disease.

Eleven patients with Legg-Calvé-Perthes disease (LCP) were examined ultrasonographically for their femoral head deformity. The outline of the cartilaginous femoral head was well demonstrated, and the image obtained corresponded to that observed by arthrography. Using ultrasonography, a simple method was developed to determine the rate of deformity due to LCP. Ultrasonography does not have the hazards of x-ray and is useful for the diagnosis of LCP.

Arthrography↗