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Biomedical subjects

S Uga

Publications and source records attributed to S Uga.

At least 73 records · Page 4Linked to original sources
PubMed1990

A human case of zoonotic onchocerciasis in Japan.

A 2-year-old girl living in southwestern Japan had a nodule of 2 months' duration on the left foot. A biopsy from the lesion showed transverse sections of a worm surrounded by granulomatous tissue. The worm was identified as an Onchocerca sp. from the morphological characteristics such as relatively thick cuticles, annular ridges on the cortical layer, and high somatic muscles. Positive serological tests using ELISA for Onchocerca gutturosa and Onchocerca volvulus supported the diagnosis. This was the first case of zoonotic Onchocerca infection detected in Japan. The clinicopathological aspects of zoonotic onchocerciasis of this case were discussed.

Child, Preschool↗
PubMed1990

[Acute renal failure in a case of paroxysmal nocturnal hemoglobinuria--a review of literature in Japan].

A case of paroxysmal nocturnal hemoglobinuria (PNH) associated with acute renal failure (ARF) is described. A 57-year-old female, who had been diagnosed as having PNH in 1983 at Kochi Medical School, was admitted to our hospital in April 1989, because of ARF with dark urine after a common cold. Hemodialysis was performed 5 times for ARF, and after almost completely recovering from ARF, she was discharged. The renal biopsy showed the deposition of hemosiderin in the proximal tubular cells. We surveyed fourteen case reports of PNH associated with ARF in Japan including our case. Ten cases developed ARF after infection causing hemolytic attack. Twelve of 14 cases were treated by hemodialysis and 13 cases were reversible. The histopathology of their renal biopsies revealed the deposition of hemosiderin in the proximal tubular cells in six of seven cases and tubular necrosis in three cases. These data showed that hemolytic attack and dehydration related to infection facilitated the induction of ARF.

Acute Kidney Injury↗
PubMed1989

Enzyme-linked immunosorbent assay as a diagnostic method for schistosomiasis haematobium. Standardization and application in the field.

An enzyme-linked immunosorbent assay was employed for the quantification of antibodies to Schistosoma haematobium in both human serum and urine samples. The serum ELISA was reproducible with coefficients of variation in intra-day tests and inter-day tests being 2.54-3.64% and 5.04-7.48%, respectively. The specificity of serum ELISA was 100% and its sensitivity was 97%. When the eggs recovered from patients' urine were used for antigen, there occurred non-specific reactions, which were markedly decreased by pepsin treatment of the eggs. In addition, urine could also be used for detecting egg-positive persons with a specificity of 91% and a sensitivity of 97%. However, under field conditions, the specificity of urine ELISA was 82% and its sensitivity was 92%.

Animals↗
PubMed1989

[Morphological study of innervation of orbicularis oculi in the cat with respect to motoneurons, nerve fibers and muscle fibers].

It has been suggested that the orbicularis oculi muscle functions in different modes of action in the orbital portion and in the palpebral portion. To study the anatomical correlation between the localization of muscular division and the size of motoneurons in facial nucleus, the retrograde tracing method was used. A histochemical study on the type of muscle fibers was also performed. The relationship between the motoneurons, nerve fiber and muscle fiber was discussed in terms of the functional organization of the palpebral or orbital orbicularis oculi. We injected a tracer of 50% horseradish peroxidase (HRP) into the orbital and/or palpebral portion of the orbicularis oculi muscle and HRP-labelled motoneurons at the brainstem were studied. In the facial nucleus, four subnuclei have been described: the ventrolateral, ventromedial, dorsolateral and dorsomedial. HRP-labelled motoneurons which innervated both the orbital and palpebral portions were spindle shaped and were found ipsilaterally in the dorsolateral subnucleus, and were distributed rostrocaudally. The histogram of the average soma diameter traced by the injection in the orbital portion presented two peaks at 30 microns and 40 microns in contrast to one peak of palpebral portion. Secondly, a histochemical study using alkali (pH 10.4) preincubated ATPase and acid (pH4.3) preincubated ATPase and NADH stain was performed. It was found that the muscle fibers of the orbital part were composed predominantly of large and middle diameter group II B, while the palpebral part consisted mainly of small diameter group II A. By diameter analyses of the facial nerve fibers, it was found that the myelinated nerve fibers consisted of 3 peaks in terms of the magnitude of histogram.

Animals↗
PubMed1988

Histopathological study of Emory mouse cataract.

Lenses of Emory mice, ranging in age from 7 days to 15 months, were studied by light and electron microscopy. The earliest change was acellularity in the lens epithelium, which was found at postnatal day 14. This acellularity was relatively mild but constantly occurred throughout the experimental course. The early cortical fiber change was swelling in the anterior region of the lens at 1 month of age. At 2 months of age some cell extensions towards the capsule appeared at the basal surface of the posterior cortical fibers near the equatorial region, and their height and number had greatly increased by 4 months of age. Following this change, there was an enlargement of nuclei in the bow area, swelling of cortical fibers, and separation of the posterior suture line. These changes became severe by 6 months of age. When the separation of the posterior suture and disturbance of the posterior cortical fibers became markedly severe, the cataract reached a mature stage, showing the complete opacity of the cortex. This animal model appears to indicate that the viability and/or behavior of the epithelial cells is important for maintaining the transparency of the lens throughout the lifespan.

Aging↗
PubMed1987

Distribution and orthograde axonal transport of HRP in feline eyes following intravitreal injection: an ultrastructural study.

The retina and optic nerve in the cat were examined by electron microscopy at five different time periods (1-, 3-, 8-, 16- and 24 hr) following the injection of horseradish peroxidase (HRP) into the vitreous cavity. Intra- and intercellular HRP was found in ganglion cells, Müller cells and horizontal cells even at 1 hr. Intra-axonal HRP in the retina and the retrolaminar optic nerve was seen most frequently at 3- and 8 hr. At 16- and 24 hr, many phagocytes containing HRP were noted in the nerve-fibre layer; subsequently HRP activity decreased throughout the retina. On the other hand, HRP activity in the intracanalicular optic nerve was significantly increased at 16 hr. Intra-axonal HRP appeared to be morphologically distributed in two forms: (i) HRP granules bound by a single-unit membrane mostly 0.1-0.4 micron in diameter; (ii) granules less than 0.05 micron which were occasionally hard to distinguish from artefacts such as stain deposit. The rate of orthograde axonal transport of HRP granules larger than 0.05 micron was examined on the basis of the frequency of HRP granules appearing in the retrolaminar and intracanalicular parts of the optic nerves. Though the rate seemed to be widely variable, the major velocity was calculated to be 45 mm per day, which is equal to intermediate axonal flow rates.

Animals↗
PubMed1986

Ultrastructural study of rainbow trout lenses incubated under various conditions.

The pathology of rainbow trout lenses incubated in various media and at various temperatures was examined by electron microscopy. After incubation at 0 degrees C for 5 h, no changes were observed in transparency and cytology. Irreversible warm cataract occurred at 37 degrees C, which corresponds to the body temperature of mammals. The degree of turbidity increased depending on incubation time. The ultrastructure of warm cataract in short-term incubation was characterized by the appearance of dense substances in the epithelium and swelling of the lens fibers. When the incubation time was prolonged up to 3 h, the turbidity increased and cellular disorders became severe. The volume of the dense substances increased also. A slight but detectable haziness of the lens was observed after incubation with calcium-free medium. Pathological findings in this case consisted of disorders of the intracellular membrane system in the epithelium and swelling of the lens fibers. These results suggest that the rainbow trout lens has a lower optimum temperature compared to the mammalian lens but requires the same Ca2+ concentration.

Animals↗
PubMed1985

Electron-microscopic study of iris nerves and muscles in diabetes.

The ultrastructure of the iris muscles and innervating nerves in patients with diabetes mellitus and approximately age-matched controls was examined by electron-microscopy. The specimens were obtained during cataract surgery. There were definite histopathological alterations at the nerve terminal innervating the dilator muscle, e.g. the presence of mitochondrial abnormalities, dense bodies and lamellar structures. No change was noted at the nerve terminal to the sphincter muscle. Moderate involvement of the muscle, especially at the sphincter, was observed in the specimens of diabetics. The control specimens had no change at the nerve terminals, while moderate change was observed at the sphincter muscle. Therefore, the change in the sphincter seen in the specimens of diabetics seemed to be mainly the result of the aging process, though the existence of early sympathetic neuropathy was confirmed.

Aged↗
PubMed1985

Orthograde axonal transport of optic nerve and injury--morphological study.

To investigate the effects of injury to the orthograde axonal transport in the optic nerve, horseradish peroxidase (HRP) was injected into the vitreous of the cat eye after various types of optic nerve injury, and the retina and optic nerve were examined with light and electron microscopes 8 hours after the injection. The optic nerve was sectioned in one eye at about 6 mm behind the eyeball and the optic nerve of the contralateral eye was used as the control. HRP reaction products were frequently observed within the retinal ganglion cells and their axons of the nerve fiber layer as well as in the retrolaminar optic nerve on the experimental side, and the findings were similar to those on the control side. The optic nerve was injured by cryocoagulation for 10 seconds or 30 seconds, and ischemic changes of various degrees were induced. Intracellular and intra-axonal HRP reaction products were markedly reduced at the retrolaminar portion, and the degree of reduction depended on the duration of cryocoagulation. The section of the optic nerve had, at least in the early stage, only minimal effects on the orthograde axonal transport, but the optic nerve injury accompanied by ischemic changes markedly blocked the axonal transport in both the inner part of the retina and the optic nerve.

Animals↗
PubMed1983

Retinal degeneration in rats exposed to an organophosphate pesticide (fenthion).

Pigmented (Long-Evans) and albino (Wistar) rats were chronically exposed to an organophosphate pesticide (fenthion). Fenthion (50 mg/kg) was administered subcutaneously twice a week for 1 year; the total dosage for each animal ranged from 1.6 to 1.8 g. Concurrent with the fenthion administration, the amplitude of the scotopic electroetinogram (ERG) gradually declined, disappearing by the 12th month in all treated pigmented rats. For the albino experimental rats, however, the ERG amplitude disappeared as early as the 6th month in 7 out of 15 treated animals. Funduscopically, degeneration of the retina was observed in all rats when ERG responses had disappeared. Histopathological studies confirmed degeneration of the sensory retina and marked abnormalities in the pigment epithelium cells. Treated pigmented rats also had reduced a rhodopsin concentration in the retina by the 3rd month even though the photoreceptors were structurally normal. Interestingly, the plasma vitamin A levels remained normal and liver stores of vitamin A actually increased during the course of the study. Levels of butylcholinesterase in plasma and liver, on the other hand, were extremely reduced after 3 months of fenthion treatment. In general, the biochemical and functional (ERG) changes appeared before any structural damage could be detected in the retina.

Animals↗
PubMed1983

Studies on the cryopreservation of eggs of Angiostrongylus cantonensis.

The possibility of cryopreserving the eggs of Angiostrongylus cantonensis collected from the uterus of female worms was investigated. Eggs were cultured in NCTC 109 medium containing 50% rat serum, and various growth stages, from one-cell eggs to embryonated eggs, were used in this study. As a cryoprotective agent, dimethylsulphoxide (Me2SO) was added to the medium at a final concentration of 1 M. Eggs suspended in 0.2 ml of the medium at 37 degrees C were cooled to 0 degrees C at a rate of 1 degree C min-1, then an equal volume of 2M-Me2SO solution was added. After equilibration for 15 min, the freezing procedures were started. In the freezing procedures, the effectiveness of (i) a seeding process, (ii) different cooling and warming rates and (iii) the relationship between the growth stages of the eggs and their tolerance to freezing at -20 degrees C were investigated. It was found the highest level of survival could be obtained with 32-cell eggs cooled at a rate of 0.3 degrees C min-1 or more slowly with seeding at -4 degrees C and warming at a rate of 5 degrees C min-1. Survival was influenced more by cooling rate than by warming rate. Using these optimum conditions, the survival of eggs was then investigated following cooling to various temperatures. While more than 50% of eggs were found to survive cooling to -30 degrees C, extremely low survival was noted from lower temperatures.

Angiostrongylus↗