PubMed Health⌕ Search

Biomedical subjects

H Tateda

Publications and source records attributed to H Tateda.

At least 19 recordsLinked to original sources
PubMed1988

Dynamic relationship between the slow potential and spikes in cockroach ocellar neurons.

The relationship between the slow potential and spikes of second-order ocellar neurons of the cockroach, Periplaneta americana, was studied. The stimulus was a sinusoidally modulated light with various mean illuminances. A solitary spike was generated at the depolarizing phase of the modulation response. Analysis of the relationship between the amplitude/frequency of voltage modulation and the rate of spike generation showed that (a) the spike initiation process was bandpass at approximately 0.5-5 Hz, (b) the process contained a dynamic linearity and a static nonlinearity, and (c) the spike threshold at optimal frequencies (0.5-5 Hz) remained unchanged over a mean illuminance range of 3.6 log units, whereas (d) the spike threshold at frequencies of less than 0.5 Hz was lower at a dimmer mean illuminance. The voltage noise in the response was larger and the mean membrane potential level was more positive at a dimmer mean illuminance. Steady or noise current injection during sinusoidal light stimulation showed that (a) the decrease in the spike threshold at a dimmer mean illuminance was due to the increase in the noise variance: the noise had facilitatory effects on the spike initiation; and (b) the change in the mean potential level had little effect on the spike threshold. We conclude that fundamental signal modifications occur during the spike initiation in the cockroach ocellar neuron, a finding that differs from the spike initiation process in other visual systems, including Limulus eye and vertebrate retina, in which it is presumed that little signal modification occurs at the analog-to-digital conversion process.

Animals↗
PubMed1986

Dynamics of cockroach ocellar neurons.

The incremental responses from the second-order neurons of the ocellus of the cockroach, Periplaneta americana, have been measured. The stimulus was a white-noise-modulated light with various mean illuminances. The kernels, obtained by cross-correlating the white-noise input against the resulting response, provided a measure of incremental sensitivity as well as of response dynamics. We found that the incremental sensitivity of the second-order neurons was an exact Weber-Fechner function; white-noise-evoked responses from second-order neurons were linear; the dynamics of second-order neurons remain unchanged over a mean illuminance range of 4 log units; the small nonlinearity in the response of the second-order neuron was a simple amplitude compression; and the correlation between the white-noise input and spike discharges of the second-order neurons produced a first-order kernel similar to that of the cell's slow potential. We conclude that signal processing in the cockroach ocellus is simple but different from that in other visual systems, including vertebrate retinas and insect compound eyes, in which the system's dynamics depend on the mean illuminance.

Acoustic Stimulation↗
PubMed1986

Two Japanese cases of battered child syndrome with retinal hemorrhage.

We present 2 cases of battered child syndrome with retinal hemorrhage. Case 1 is a 6-year-old boy who was blinded in both eyes following abuse by his mother's common-law husband. Retinal hemorrhages and optic atrophy were found in both eyes. Case 2 is a 6-month-old boy who developed dyspnea following episodes of abuse by his mother's common-law husband. Retinal hemorrhages were visible in both fundi. We believe that retinal hemorrhage is the most frequent clinical finding in abused children and its presence should alert the ophthalmologist to suspect battered child syndrome.

Battered Child Syndrome↗
PubMed1985

Visual interneurons in the lobula complex of the fleshfly, Boettcherisca peregrina.

The physiology and morphology of visual interneurons in the lobula complex of the fleshfly, Boettcherisca peregrina, were studied using intracellular recordings and intracellular cobalt stainings, respectively. Using responses to movements of a spot of light and on-off stimuli at single positions, we classified the interneurons into five physiological groups ON, OFF, ON-OFF, non-directional motion sensitive (NDM) and directional motion sensitive (DM) neurons. They could be further divided into four morphological types, depending on the location and extent of their dendrites and terminal branches.

Animals↗
PubMed1984

Follow-up study of a nation-wide neonatal metabolic screening program in Japan. A collaborative study group of neonatal screening for inborn errors of metabolism in Japan.

A nationwide neonatal screening program for phenylketonuria (PKU), maple syrup urine disease (MSUD), homocystinuria, histidinemia and galactosemia was started in Japan in 1977. The total number of infants screened had reached 6,311,754 by March, 1982. A follow-up study revealed the incidence of the disease in Japan: 1/108,823 for PKU; 1/450,840 for hyperphenylalaninemia (HPA); 1/1,577,939 for biopterin deficiency; 1/525,980 for MSUD; 1/1,051,959 for homocystinuria; 1/8,371 for histidinemia, and 1/788,969 for galactosemia type 1. The incidences of PKU, HPA, homocystinuria, and galactosemia (type 1) were found to be markedly low in Japan as compared with those in Caucasian countries. There was no great difference in the incidence of MSUD between both. On the other hand, the incidence of histidinemia was higher in Japan. It was found that most of the patients with PKU, HPA, MSUD, homocystinuria, or galactosemia are developing normally due to the early initiation of dietary treatment. These results clearly indicate that the neonatal mass screening program plays a great role in preventing the occurrence of handicapped children.

Biopterins↗
PubMed1984

Termination profiles of photoreceptor cells in the larval eye of the swallowtail butterfly.

Profiles of the axonal endings of seven retinular cells (R1-7) from each of six stemmata (I-VI) of the butterfly Papilio xuthus were examined. Their axons enter the brain anteroventrally and project dorsally along the brain's lateral surface before entering the optic neuropil. Larval optic neuropil has two distinct areas, a (distal) lamina and a (proximal) medulla, connected by a chiasma. Intracellular administration of cobalt shows that distal retinular cells (R1-3 of stemmata I-IV, R1-3 and R6 of stemmata V and VI) terminate as short axons with plug or toothbrush-like endings in the lamina. Proximal retinular cells (R4-7 of stemmata I-IV, R4, R5 and R7 of stemmata V and VI) terminate as long axons in the chiasma or in the medulla. The long axons have fine branches in the lamina, chiasma and medulla. The two proximal cells (R5 and R7) are distinguished by their deeper endings and longer branches. The terminals of photoreceptors correspond to their photoreceptive properties and provide further evidence for the functional specialization of the photoreceptors.

Animals↗
PubMed1984

Lens subluxation in homocystinuria. A case report.

A 6-year-old girl had bilaterally subluxated lenses and liver and platelet dysfunctions. A cyanide-nitroprusside test of the urine was positive. Serum and urinary levels of methionine and homocystine were high. Cystathionine synthetase activity in the cultured skin fibroblasts was negligible. Pyridoxine, 1000 mg/day orally, normalized the serum and urinary methionine and homocystine levels and the liver and platelet functions. Episodes of pupillary block glaucoma prompted lens extraction. The subluxated lenses were extracted under general anaesthesia after administration of pyridoxine and dextran to avoid thrombosis. A good result without serious complications was obtained. We believe that homocystinuria should not be considered a contra-indication to general anaesthesia. In the pyridoxine-responsive patient general anaesthesia is not hazardous if platelet function can be controlled by the vitamin.

Anesthesia, General↗
PubMed1982

Antennal hygroreceptors of the honey bee, Apis mellifera L.

Antennal hygroreceptors of the honey bee, Apis mellifera L., have been investigated electrophysiologically and the sensillum containing these receptors with SEM. Moist and dry hygroreceptors have been identified along with a thermal receptor in a specialized coeloconic sensillum. This sensillum comprises a cuticular, shallow depression (diameter; 4 micrometer) having a central opening (1.4-1.5 micrometer) and a mushroom-shaped protrusion (1.4-1.5 micrometer) from the opening. The head of the protrusion is irregular in shape and is not perforated. This sensillum has been thus far referred to as a "sensillum campaniformium" (Dietz and Humphreys 1971), henceforth, it is referred to as a coelocapitular sensillum. The responses of both moist and dry hygroreceptors are of a phasic-tonic manner. Both receptors are antagonistic with respect to their responses to humidity; one responds with an increase in impulse frequency to rising humidity, the other to falling humidity. The humidity-response relationship is independent of stimulus flux.

Animals↗
PubMed1982

Glycine cleavage system in ketotic hyperglycinemia: a reduction of H-protein activity.

Glycine cleavage activity was compared in the livers from three cases of ketotic hyperglycinemia (two cases of propionic acidemia and one case of methylmalonic acidemia) and three controls. In one case of propionic acidemia, glycine cleavage activity (5.2 nmole/mg protein/hr) was normal in the liver obtained at biopsy when the patient was well controlled by the treatment with low protein diet (0.8 g/kg/day) and the level of serum glycine was lowered to normal. In the two other cases of ketotic hyperglycinemia, glycine cleavage activity was significantly reduced in the liver obtained at autopsy when the patients died in the state of metabolic acidosis. Its activity in the liver of one case of propionic acidemia (0.7 nmole/mg protein/hr) was 6-26% of that in controls (2.7-10.8 nmole/mg protein/hr), and 2-7% in the case of methylmalonic acidemia (0.2 nmole/mg protein/hr). Analysing of the individual components of the glycine cleavage system, a marked decrease in the activity of H-protein was revealed in the livers of the both patients; it (0.2 nmole/mg protein/hr) was only 3-4% of that in controls (4.9-6.3 nmole/mg Protein/hr). These findings suggest that the reduction of the glycine cleavage system in the liver of ketotic hyperglycinemia occurs secondarily as speculated previously and is caused mainly by a decrease of H-protein activity.

Acidosis↗
PubMed1982

Galactose cataract in Japanese patient.

A Japanese infant was found to have abdominal distension at the age of 4 weeks. A diagnosis of galactosemia was made at 8 weeks of age. Dietary management completely reversed the hepatosplenomegaly and ceased the progression of lens opacities. Mental retardation was also noted at a later age. We believe this is the first reported case of galactose cataract in Japan confirmed enzymatically.

Cataract↗
PubMed1981

Analyses of cystine in human hair: its level in women's hair of former times.

An appropriate procedure for analysis of cystine in the hair has been established, and this procedure was applied to the hair of Japanese women. The recovery of authentic cystine added to a hair sample was 85-90% in 6N HCl hydrolysis, and 96% in acid hydrolysis after performic acid oxidation. The 18-hr acid hydrolysis, but not 4-hr one, was sufficient to digest the hair. In colorimetry by using phosphotungstate, Brown's reagent gave a stable color development. The cystine content by amino acid autoanalysis was significantly correlated with that by the phosphotungstate colorimetry by the modified method of Kassel et al. or of Shinohara. The cystine content in women's hair, which was collected from specimens of different individuals cut during the period from 1910s to 1980, indicated a wide variation ranging from 0.654 to 1.607 mmol half-cystine per g of hair after washing with 0.5% sodium laurylsulfate.

Adult↗
PubMed1978

Fine structure of the eyes of orb-weavers, Argiope amoena L. Koch (Aranea: Argiopidae). 2. The anterolateral, posterolateral and posterommedial eyes.

The anterolateral eye, the posterolateral eye and the posteromedial eye of the web-building spider, Argiope amoena have been examined by light and electron microscopy. The dioptric apparatus of all three eyes is similar in structure, and consists of a cornea, a lens and a vitreous body. The retina contains monopolar receptor cells, the cell bodies of which are present beneath the vitreous body in all three eyes. Proximal processes of the receptor cells form rhabdoms beneath the cell body layer and then extend toward the first optic glomerulus as an ocellar nerve. Two distinct patterns of retinal organization are present in the three eyes. In one type the rhabdomic layer of the retina is backed by a pigmented layer. In the other type the rhabdomic layer is backed by a tapetal reflecting layer. Rhabdomic structure and cytoplasmic inclusions of the receptor cells differ greatly between the two types. The anterolateral eye possesses a single type of retina with the rhabdoms backed by the tapetum. Both the posterolateral and the posteromedial eye are similar in structure, each possessing beneath the common dioptric apparatus retinae of both types.

Animals↗
PubMed1977

Fine structure of the eyes of orb-weavers, Argiope amoena L. Koch (araneae: argiopidae). 1. The anteromedial eyes.

The anteromedial eye of the web-building spider, Argiope amoena has been examined with light and electron microscopy. The eye consists of a cornea, a lens, a vitreous body and a retina. The retina contains 400 to 500 bipolar photoreceptor cells and pigment ce-ls which envelop the receptor cells. Microvilli extend laterally from the distal process of each receptor cell beneath the vitreous body. The microvilli interdigitate with those from neighboring processes to form rhabdoms. Multivesicular bodies occur in the rhabdomeric portion, and in an intermediate segment, between the rhabdomeric portion and the receptor cell body, are found mixed lamellar vesicular bodies and lamellar bodies. A single axon extends from the receptor cell. The site of origin of the axon from the cell varies depending on the location of the cell in the retina. The axon originates on the intermediate segment, or on the lateral surface or proximal end of the cell body. The axons join together in the postero-dorsal region of the eye and then extend to the first optic glomerulus as an ocellar nerve of about 3 mm in length. The pigment cells, whose cell bodies lie among those of the receptor cells or the axons, possess cytoplasmic prolongations which reach up to the vitreous body.

Animals↗