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Biomedical subjects

T Ando

Publications and source records attributed to T Ando.

At least 685 records · Page 38Linked to original sources

Retinotoxic effects of diaminodiphenoxybutane in rats.

The effects of diaminodiphenoxybutane (DAPB) on visual function in rats were studied using behavioral, electrophysiological and histological techniques. A light-dark discrimination test was conducted by an operant behavioral method. DAPB did not modify intensity detection threshold at an intravenous dose of 35 mg/kg, but elevated it at doses of 50 and 70 mg/kg. Secondly, DAPB did not produce any changes in either electroretinogram (ERG) or visually evoked potential (VEP) at the dose of 35 mg/kg, but a marked decrease in the amplitude of the ERG a- and b-waves appeared after the doses of 50 and 70 mg/kg. The latency of the VEP first wave was also prolonged dose-dependently. Finally, retinal lesions were revealed in rats receiving 70 mg/kg. These results indicate that DAPB has a toxic effect on the retina in rats.

Animals↗

Myoglobinemia in Duchenne muscular dystrophy carriers.

We have carried out serum assays for myoglobin in parallel with the determination of serum CPK activity to assess its usefulness in raising the detectability rate of Duchenne muscular dystrophy carriers. Of the 14 carriers, ten (71.4%) had high serum levels of myoglobin and nine (64.3%) showed increased serum CPK levels. Either parameter revealed elevation in 11 (78.6%) of the 14 cases studied. Serum myoglobin determination is of noticeable value in the detection of Duchenne muscular dystrophy carriers.

Adolescent↗

Stimulation of herpes simplex type I infection of C6 cells by trypsin-EDTA.

The nature of the refractoriness of C6 glioblastoma cells to herpes simplex virus type I (HSV-I) infection has been studied. The cells were restricted in susceptibility to HSV-I since only a small proportion of the cells could be infected by HSV-I and the virus yield per cell was low. The susceptibility to infection was increased by treating the cells with trypsin-EDTA prior to infection. The cells so treated recovered resistance to the virus when incubated at 37 degrees C, their resistance being restored to the initial level in 2 days. This restoration was inhibited by addition of cycloheximide or puromycin. Trypsin-EDTA treatment of C6 cells increased the efficiency of adsorption of HSV-I and the formation of stable cell-virus complexes from which the virus could not be dissociated by heparin.

Adsorption↗

Induction of 2',5'-oligoadenylate synthetase and interferon in mouse trigeminal ganglia infected with herpes simplex virus.

The activity of 2',5'-oligoadenylate synthetase, which is induced by interferon action, was detected in mouse trigeminal ganglia infected with herpes simplex virus (HSV) type 1. When HSV was inoculated on the left cheek of mice, the virus began to appear in the ipsilateral trigeminal ganglia on day 2, reached its maximum accumulation on day 4, declined thereafter, and was no longer detected in the tissue homogenate after 11 days. After this short acute productive phase, the virus entered into the latent phase of infection. 2',5'-Oligoadenylate synthetase appeard in the trigeminal ganglia shortly after the beginning of virus multiplication; the synthetase activity began to rise on day 3, reached a maxium level on day 4, and then declined. Interferon activity (type I) also appeared in the infected ganglia, but diminished more rapidly than the synthetase. The antibody against HSV in the sera began to appear at the time when the virus and synthetase were declining. From these results it may be hypothesized, although not concluded, that in the acute productive phase of HSV infection in mouse trigeminal ganglia, virus multiplication is suppressed by interferon action, including 2',5'-oligoadenylate synthetase induction.

2',5'-Oligoadenylate Synthetase↗

Role of endocrinological factors in the pathogenesis of idiopathic edema.

In order to investigate the etiology of idiopathic edema, clinical findings and endocrinological abnormalities were analyzed in twenty-seven patients, and the following results were obtained. An easy occurrence of subcutaneous bleeding and positive Rumpel-Leede phenomenon were observed in the majority of the patients. ADH, plasma renin activity and plasma aldosterone concentration in the patients did not show abnormalities following water loading in the supine position when compared with normal controls. But the results obtained in the present study suggested that they might contribute to water and sodium retention in the upright position. In the patients, plasma prolactin levels were not decreased, but rather increased and urinary excretion of kallikrein and kinin was reduced significantly after water loading in the upright position. Thus, prolactin and urinary kallikrein-kinin system might also contribute to water and sodium retention in idiopathic edema, directly or indirectly through the augmentation of the action of ADH and of aldosterone. It was concluded that the increased vascular permeability and endocrinological polyfactors play a role, in a cooperative fashion, in the mechanism of this disease.

Adult↗

Cefoxitin resistance by a chromosomal cephalosporinase in Escherichia coli.

Cefoxitin resistance, an unique property found in clinical isolates of Escherichia coli was investigated. Cefoxitin resistant strains, 255 and GN206, produced cephalosporinase constitutively. The cephalosporinase was located in the periplasm, and its production was considered to be mediated by chromosomal gene(s). Cephalosporinase-less mutants from both strains were susceptible to cefoxitin as well as other beta-lactam antibiotics, suggesting that the cephalosporinase was responsible for the resistance to beta-lactam antibiotics including cefoxitin. The cephalosporinases from the E. coli strains were partially purified and their enzymological properties were compared with those of cephalosporinases of Citrobacter freundii and Proteus morganii. Although the cephalosporinases of E. coli, as well as other cephalosporinases, showed little activity for cefoxitin-hydrolysis, the E. coli cephalosporinases exhibited a significantly higher affinity for cefoxitin than other cephalosporinases. It was assumed that the E. coli enzyme located around the targets of cefoxitin protected the targets from the antibiotic by its high affinity for the antibiotic.

Cefoxitin↗

Electric potential at regions near the two specific thiols of heavy meromyosin determined by the fluorescence quenching technique. I. Effect of ATP.

Electric potentials at regions near the two specific thiol groups, SH1 and SH2, of the heavy meromyosin (HMM) molecule were studied by the fluorescence quenching technique. The effects of binding of ATP to HMM upon the electric potentials were also studied. N-(p(2-Benzimidazolyl)phenyl)maleimide (BIPM) was used as a thiol-directed fluorescent reagent. Prior to the labeling of SH2 with BIPM, the SH1 group was blocked with N-ethylmaleimide (NEM). Iodide ions (I-), thallium ions (Tl+), and acrylamide were used as quenchers of fluorescence. The sign of the electric potential was collectively determined from the dependence of the Stern-Volmer constants upon the ionic strength of solutions. 1. The region near SH1 was at a negative electric potential, whereas the electric potential at the region near SH2 was almost zero. 2. On the addition of ATP, the fluorescence intensity of BIPM bound to SH1 was unchanged, whereas that of BIPM bound to SH2 was greatly decreased to about 50% of the original level. The fluorescence intensity recovered as the added ATP was split into ADP and orthophosphate, and became saturated. The saturated level of the fluorescence intensity was, however, smaller than the original one, due to binding of the produced ADP to HMM. 3. On the addition of ATP, the negative electric potential at the region near SH1 was unchanged, whereas a negative electric potential with large gradient was newly introduced at the region near SH2. The value of the newly introduced electric potential was calculated on the basis of various assumptions. These results are discussed in connection with the functions of myosin.

Acrylamides↗

[Intracerebral germinoma developing in the right basal ganglia--report of a case followed up by CTscan and review of the literature (author's transl)].

Recently, a case of intracranial germinoma in the right basal ganglia was experienced in our department. He was a 14-years old boy with left motor hemiparesis. On repeated CT studies (7 times), developmental process of the tumor was observed for about 2 years. The tumor developed from the right putamen and invaded toward it's neighboring area (right basal ganglia, thalamus and hypothalamus). As the tumor grew larger, multiple cysts were formed in the tumor tissue and dislocation of ventricles occurred. On 21 December 1978, right temporal craniotomy was performed and a piece of the tumor was removed. It's tissue was diagnosed as germinoma by pathohistological examination. As the effect of postoperative 60Co irradiation and chemotherapy (Vicristine, CCNU), tumor stain (high density area) on CT scann disappeared and remained only as a well margined low density area. On CT scan in September 1979, recurrence sign was not noted. Clinical features of the germinoma located in the basal ganglia has not been well known, because of it's rarity. As a result of the survey of 7 cases reported in the Japanese literature and our case, it has been made clear that most of them are characterized by motor hemiparesis in the early stage, not accompanied by intracranial hypertension.

Adolescent↗

[Trigeminal neurinoma with massive extracranial extension, report of a case (author's transl)].

It appears that more than a hundred cases of trigeminal neurinomas have hitherto been reported, but massive extracranial extension of a benign neurinoma into the sphenoid sinus and soft part tissue of the neck is unusual. A 36-year-old woman was admitted to our clinic with complaints of left blindness, vertigo and left nasal stuffiness. Neuroradiological examinations, including plain craniography, angiography and CT, showed a huge mass which destroyed the left middle fossa and extended into the left sphenoid sinus and soft part tissue of the neck. On December 14, 1978, left fronto-temporal craniotomy was carried out, and intracranial portion of the tumor was removed, leaving its extracranial portion intact. Pathological examination revealed benign neurinoma. The postoperative course was uneventful except temporary left total ophthalmoplegia. It was emphasized that, to obtain cure for trigeminal neurinoma, early diagnosis is extremely important, and, for this purpose, CT, including coronal one, was considered to be one of the most useful examinations.

Adult↗

Charge effects on the dynamic quenching of fluorescence of 1,N6-ethenoadenosine oligophosphates by iodide, thallium (I) and acrylamide.

Systematic studies were carried out to determine how the dynamic quenching of fluorescence was affected by electrostatic interaction between charges carried by the fluorophore and the quencher. 1,N6-Ethenoadenosine oligophosphates (epsilon-ATP, epsilon-ADP, epsilon-AMP, and epsilon-Ad) were used as fluorophores; these compounds have the same luminous group (epsilon-adenine ring) with variously charged phosphate groups. Acrylamide and the iodide (I-), well known to be effective quenchers carrying zero and one negative charge, respectively, were used as quenchers. The thallium (I) (Tl+) was also found to be an effective quencher as a result of studies of the quenching activity of various positively charged ions. Results which agreed qualitatively with those expected were obtained for the charge effects on the dynamic quenching and the effects of ionic strength on it. That is, the repulsive force exerted between I- and phosphate groups decreased the quenching rate, and increasing ionic strength of solutions mitigated these charge effects. The results obtained, however, were not quantitatively consistent with theoretical expectations for ionic reaction rates in solutions. One reason for the quantitative disagreement is that the negatively charged phosphate groups are located at a distance from the luminous group. By theoretical analysis of the quenching data, the distance was calculated to be 9.6 A + delta r, where delta r changes according to the number of phosphate groups. Furthermore, through a theoretical analysis of the disagreement, we found a new factor, the "size effect" of a luminous group, which modifies the charge effects on dynamic quenching. The size effect provides information on the gradient of the electric potential generated by the phosphate groups. These studies provide a basis for the study of electric potential at local regions of proteins.

Acrylamides↗