Biomedical subjects

S Uga

Publications and source records attributed to S Uga.

At least 55 records · Page 3Linked to original sources

PubMed1996

Seroepidemiological study of Toxocara infection in Nepal.

Seroepidemiological study of Toxocara infection in Nepalese people aged more than fourteen years was carried out by enzyme linked immunosorbent assay (ELISA) using T. canis soluble embryonated egg antigen. Of the total 200 subjects included in this study, 162 (81%) were found to possess antibodies to Toxocara spp. Males showed higher (85%) antibody positive rates than females (77%). Inhabitants of Kathmandu valley showed higher antibody positive rates (84%) compared with those living outside of the valley (78%). These differences, however, were not significant statistically (p > 0.05). Ethnically, Newar, Rai/Limbu, Tamang/Sherpa, Brahmin/Chhetri, Jha/Yadavs, and others (Kami, Damai) showed Toxocara antibody positive rates of 85, 85, 83, 70, 77 and 100%, respectively. Half of the Toxocara antibody positive subjects (49%) showed an elevated level (two plus) of antibody.

Adolescent↗

PubMed1995

The use of PCR in detecting toxoplasma parasites in the blood and brains of mice experimentally infected with Toxoplasma gondii.

Polymerase chain reaction (PCR) has been extensively used for diagnosis recently because of its very high sensitivity and specificity. We studied the applicability of PCR to the early diagnosis of toxoplasmosis in a murine model orally infected with Toxoplasma gondii (S-273). PCR was performed using EH24 and HE27 primers synthesized by the phosphoramidite method. Mice blood and brains collected on various post infection days (PID) were analysed by PCR (35 cycles). A portion of the brain tissue from each mouse was examined microscopically for the presence of parasite cysts. Blood and brain PCR were positive on the 9th and 12th day post-infection (DPI). Toxoplasma cysts in brain tissue appeared only on the 18th PID. The results showed that Toxoplasma parasites can be detected earlier in the blood than in the brain during primary infection, indicating that blood PCR is the more useful procedure.

Animals↗

PubMed1995

Abrupt-onset diabetes mellitus in the elderly.

We present three elderly Japanese patients with abrupt onset of diabetes mellitus: a 61-year-old male with a complete defect of insulin secretion without insulin resistance, a 60-year-old male with an incomplete defect of insulin secretion associated with insulin resistance, and a 69-year-old female with a complete defect of insulin secretion and insulin resistance. The findings in these cases indicate the heterogeneity in insulin secretion and sensitivity of abrupt onset diabetes mellitus in the elderly. The changes in insulin secretion and sensitivity over time due to glucose toxicity may at least partially explain the heterogeneity.

Aged↗

PubMed1995

Measures to control Toxocara egg contamination in sandpits of public parks.

We investigated measures to prevent Toxocara egg contamination of sandpits. Replacement of contaminated sand was not effective because 1-9 new fecal deposits per sandpit were found daily, with eggs reappearing in the sand 6-9 weeks after the replacement. When the sandpit was covered with a clear vinyl sheet, the temperature of the sand to a depth of 3 cm was 42 degrees C or more for 3 hr when the air temperature was higher than 30 degrees C. This procedure prevented contamination by fecal deposits and also resulted in the destruction of existing eggs because the sandpit was kept dry on rainy days. The method seemed safe and inexpensive. The effectiveness of a fence around a sandpit depended on user behavior, which could not be relied upon. Therefore, a practical method for the prevention of Toxocara egg contamination of sandpits is to cover the sandpit with a clear vinyl sheet at night and on rainy days.

Animals↗

PubMed1995

Contamination of soil with parasite eggs in Surabaya, Indonesia.

Soil was examined for contamination by parasite eggs in Surabaya Indonesia. Surveys were carried out on three occassion; July, 1993 (dry season), March, 1994 (rainy season), and August, 1994 (dry season). Throughout the study, five species of nematode eggs (Ascaris lumbricoides, Toxocara cati, Trichuris trichiura, Physaloptera sp, Capillaria sp), two species of cestode eggs (Hymenolepis diminuta, Spirometra erinacei), and one species of protozoa oocyst (Isospora felis) were detected. The contamination rate and number of species found from the soil were significantly different in the dry and rainy seasons. In the dry season, the prevalence was 8-20%, with two to four species detected. During the rainy season, this rate was 83% with eight species, suggesting parasite infection to possibly occur mainly in this season. The reason for this seasonal difference may be that, in spite of constant temperature around 27 to 29 degrees C throughout the year, rainfall in the dry season in only a few percent of that of the rainy season. We concluded that parasite eggs die during the dry season owing to dryness of the soil. Contamination of soil with parasite eggs and the number of species found were greater in alley-ways and at communal water supply sites around residential areas than in open-air parks or sandy beaches. The method used in the present study proved extremely effective for ascertaining the actual dynamics of parasite infection in a certain region.

Animals↗

PubMed1994

Morphological study on glucocorticoid-induced cataract in developing chick embryo.

Nishigori et al. reported a transient cataract model after administering glucocorticoid to a 15-day-old chick. Biochemically, the mechanism of onset of this cataract was though to be related to damage caused by the formation of oxidative stresses and by a protein-water phase separation. There appear to be no reports on changes in the fine structure. After hydrocortisone succinate sodium was administered to 15-day-old chick embryos, the lenses were removed at 12, 24, 30, 48, 72 and 96 h and put in 4% glutaraldehyde. The specimens were examined by light, transmission and scanning electron microscopy. Twelve to 24 h after administration to chick embryos, lens fibers containing electron-dense cytoplasm began to appear in the bow area of the equator and were still present thereafter. Thirty to 48 h after administration, numerous vacuoles of varying sizes began to appear in the lens in sites corresponding to the opaque region. These vacuoles, ranging from 2 to 8 microns in diameter, were distributed in the intercellular spaces between the lens fibers. The vacuoles had disappeared by 96 h after administration, but during that period, the height of the epithelial cells in the equatorial region and the elongation of the equatorial lens fibers had become irregular. Transient opacity was due to the presence of vacuoles of various sizes, occurring in the intercellular space between the lens fibers around the lens nucleus. Moreover, the effect of glucocorticoid administration was noted in the lens epithelium and the lens fibers in the equatorial region.

Animals↗

PubMed1994

Immunoglobulin M and G antibodies in mice in response to Toxoplasma gondii (S-273) infection and their antigen recognition patterns in western blotting on various post-infection days.

Immunoglobulin M and G antibody responses in mice experimentally infected with Toxoplasma gondii (S-273) and the reaction patterns with T. gondii (RH) tachyzoite antigens were studied on various post-infection days (PIDs) (2nd to 36th PIDs) using a commercially available IgM and IgG enzyme linked immunosorbent assay (ELISA) test systems and Western blotting (WB) technique. IgM antibody in ELISA test appeared to be positive on 12th PID (absorbance 0.764) and reached its peak level on 16th PID (absorbance 1.338) showing a slow decline thereafter with an absorbance of 0.800 even on 36th PID. Positivity of IgM was confirmed by WB except for 36th PID. IgG appeared on 16th PID with an absorbance of 0.248 and showed a steady increasing tendency even on 36th PID (absorbance 1.747). However, IgG positivity on WB was observed only on 29th PID and afterwards. On Western blots, both IgM and IgG showed interesting antigen recognition patterns on various PIDs. At the most IgM recognised seven antigens of 14kDa to 53kDa while IgG recognised eight antigens of 17kDa to 53kDa. Major antigens recognised by IgM were of 53kDa and 21kDa while the major band recognised by IgG was of 19kDa. The major bands, however, showed variability in their consistency during various PIDs. All the antigens recognised by IgM and IgG were not identical.

Animals↗

PubMed1994

Response of mouse lens to central needle injury.

We examined the difference in response to different degrees of injury in the mouse lens. The anterior side of the lens was pricked through the cornea by a microsyringe with a 31-gauge needle or an ordinary needle. The location of the needle tip was mostly marked with Evans' blue (EB) stain. At least three types of responses were recognizable. The first was a recovery type in which the wound was healed by an epithelial reaction. EB was localized at the superficial zone of the anterior cortex. The second was a type in which the change within the lens was stationary after forming a spherical body with a slightly smaller diameter than that of the entire lens. EB was observed in the intermediate zone of the anterior cortex. The third was a rapid progressive type of cataract which caused lens opacity within 3 days. The trace of the needle tip was observed around the perinuclear zone. These results suggest that the cortex of the mouse lens consists of three zones which may be functionally different around the lens nucleus: superficial, intermediate and perinuclear zones.

Animals↗

PubMed1994

Histopathological study of anterior segments of the eye with the intraocular lens in the posterior chamber.

We conducted a histopathological study of the anterior segments of the eye of a female who died 2 years after insertion of an intraocular lens (IOL), which had one end of the supporting loop inserted in the lens capsule bag and the other in the ciliary sulcus. No changes were noted in the iris and ciliary body located within the capsule. However, in the part in the ciliary sulcus, the iris root was bent towards the chamber angle and the trabecular meshwork was depressed. Moreover, the ciliary body exhibited hyaloid degeneration. A secondary cataract had formed in the periphery of the IOL. These findings suggest that the ideal site of IOL insertion might be within the capsule.

Aged↗

PubMed1994

Hourly change in cercarial densities of Schistosoma haematobium and S. bovis at different depths in the water and distances from the shore of a dam in Kwale District, Kenya.

Hourly change in cercarial densities was studied at different depths in the water and distances from the shore at a dam in Kwale District (Kenya), where Schistosoma haematobium is highly endemic, by using a filtration apparatus for detecting cercariae. The peak of cercarial density at the surface of water (2-3 cm deep) was at 11:00 hours. Those at the middle point (25 cm deep) and the bottom (50 cm deep) were at 12:00 and 13:00 hours respectively. In the morning, the majority of cercariae (79% of the total detected) was obtained at the surface of water, but none at the bottom. After midday, 40% of the cercariae were obtained at the bottom. Cercariae seemed to sink with time resulting in a wider distribution in the water. The numbers of cercariae obtained at a sampling point 20 cm from the shore, which was inside the wire-screened snail-free area, were 3.4-23 times more than those obtained at a sampling point 340 cm from the shore, indicating that cercariae were accumulating immediately near the shore. Winds might cause the accumulation.

Animals↗

PubMed1993

Histopathological study of hereditary cataractous lenses in SCR strain rat.

A new cataractous rat strain, Shumiya Cataract Rat (SCR), which was derived from the cross-breeder formed between the spontaneous hypertensive rat and the Zucker fatty rat, was studied by light and electron microscopy. The earliest change was the occurrence of some displaced nuclei in the posterior cortical fibres at birth. By 2 weeks of age, mild dysplasia of the anterior suture, aggregated epithelial cells overlying the sutural area, and poorly differentiated epithelial cells at the bow area were observable. At 3 weeks, unusually dense lens fibres near dense epithelial cells were found at the equator, and some epithelial cells showed accellularity after 4 weeks. Swelling and liquefaction of the lens fibres appeared in the anterior cortex by this stage. By 6 weeks, these changes extended toward the equatorial region. At 7 weeks, a sutural gap occurred at the anterior polar area, and this gap reached a maximum at 8 weeks. At this time, swelling of the posterior extremities of the lens fibres appeared, showing a small placoid opacity of the posterior subcapsular region under a dissecting microscope. At 10 weeks, small amounts of liquefaction were observed in this region. Between 10.5 and 11 weeks, as the posterior suture of liquefaction were observed in this region. Between 10.5 and 11 weeks, as the posterior suture separated, opacification appeared around the separated sutural area and rapidly developed into a mature cataract. The mechanism of cataract formation in the SCR rat lens may be associated with the continuous occurrence of a small proportion of poorly-differentiated epithelial cells at the bow area and sutural dysplasia of the anterior lens fibres.

Age Factors↗

PubMed1993

Morphological study of the cataractous lens of the senescence accelerated mouse.

A murine model of accelerated aging, the senescence accelerated mouse (SAM), has been developed. There are three accelerated senescence-resistant (SAM-R) strains and eight senescence-prone (SAM-P) strains. The SAM-P strains have an earlier onset and more rapid advancement of senescence resulting from a significantly shorter lifespan compared with the SAM-R strains. Spontaneous cataracts have been found in some individuals of the SAM-P/9 strain. The SAM-P/1 strain, which was used in the present study, has such systemic senescent characteristics as senile amyloidosis and alopecia, but it was previously thought that cataract does not occur in this strain. However, we found cataractous changes in the lens of these animals at early stages of their life. The earliest change was the appearance of a ripple-mark body at about 3 months of age. The number of rippled rings increased with age. These changes later induced refractive distortion of retinal vessels. Whole-mount flat preparations of the epithelium showed that the number of cells was markedly decreased at the advanced stages of cataract. At the late stages of life the lens cortex became liquefied and developed into a mature cataract. Cataract formation in this strain may be related to reduced viability of the lens epithelium.

Aging↗

PubMed1993

Prevalence of Toxocara eggs and number of faecal deposits from dogs and cats in sandpits of public parks in Japan.

Contamination of 13 sandpits in public parks in Hyogo Prefecture, Japan, by Toxocara eggs and animal faeces was studied. All 13 sandpits were contaminated with faeces. The mean number of faeces found in 1 m2 of the sandpits was 35, from which the number of faeces in each sandpit was estimated to be 261 to 2205. Toxocara eggs were detected in 12 of the 13 sandpits, each examined 4-15 times; the overall prevalence was 92%. The eggs were not always distributed in the same pattern, but in general, eggs were numerous on the sandpit surface but also present at depths of about 35 cm. Of the eggs recovered, 63% were fully embryonated. Of the 13 sandpits examined, two were heavily contaminated by eggs, and all but one of the others were mildly contaminated. The difference between heavy and light contamination was not related to differences in the environment or in the number of faeces; the cause is unknown.

Animals↗

PubMed1993

Healing response of the epithelium after lateral needle injury of mouse lens.

Characteristic changes of the epithelial healing process in germinative and equatorial zones of the ddY mouse lens were studied morphologically. After germinative zone injury, the wound was covered by proliferating epithelial cells which increased and migrated posteriorly as a function of time after injury. Epithelial posterior migration from the lens equator was mild. By contrast, with equatorial injury, the wound was covered by proliferated epithelial cells. Moreover, the equatorial area was characterized by disconfiguration of the lens bow and posterior epithelial migration. The results suggest that the larger capsulectomy in IOL operation, which damages the peripheral part of the lens epithelium, might contribute to secondary cataract.

Animals↗

PubMed1993

Histopathological study of congenitally diabetic yellow KK mouse lens.

Lenses of Yellow KK mice with marked obesity and diabetic symptoms were examined by light and electron microscopy. At 2 months of age, the entire lens appeared normal. At 4 months, however, epithelial cells sometimes had become necrotic and showed intranuclear inclusions. At 6 months, the anterior cortical fibers were swollen. At 8 months, the number of intranuclear inclusions of the epithelial cells had increased, and the posterior cortex contained densely stained cells among the fibers, with swollen cytoplasm. At 10 months, these cells had become atrophic. At 12 months, the lens cells in the posterior sutural area showed marked swelling, and the suture was almost separated. This animal model showed a slow progressive cataract in the superficial cortical zone which is similar to the diabetic cataract in human eyes.

Animals↗

PubMed1993

[A case of radiation cataract resulting from accidental irradiation of radioisotope].

We studied light and electron microscopic findings in one case of cataract resulting from accidental radioisotope irradiation. A 53-year-old male, a radiographer, was irradiated by Ga-citrate which dropped accidentally into his left eye during a radioisotope procedure. Subsequently opacity appeared in the posterior and anterior subcapsular area of the left lens and increased in intensity. Intracapsular cataract extraction was performed one and a half years after the accident. The extracted lens was studied by light and transmission electron microscopy. Epithelial cells showed frequent stratification in some sites and disappeared in others in the equatorial region. Wedl cells and vacuoles were also seen in the posterior subcapsular area. Degeneration of lens fibers, including multilayered whorls, were observed in the cortex.

Accidents, Occupational↗

PubMed1992

Effects of Schistosoma haematobium infection on mental test scores of Kenyan school children.

Adverse effects of Schistosoma haematobium infection on mental activities were studied at a primary school in rural Kenya, where the intensity of infection was light (the average egg count: < 50/10 ml of urine). The school children received three kinds of mental tests, which examine attentiveness and concentration, before and a month after treatment with a single dose of praziquantel. A pretreatment analysis showed that test scores became worse as egg counts of children increased. The praziquantel treatment improved the scores of all three tests among children who got high scores in the first tests. The study showed that even the light infection caused adverse effects on mental activities, which were detectable using simple mental tests.

Adolescent↗

PubMed1990

Morphological study of a hereditary rat cataract.

Lenses of ICR/f stain rats with hereditary cataract were examined by light and electron microscopy. The earliest change was the frequent occurrence of displaced or migrated nuclei in the posterior sutural area at birth. Unusual dense fibers at the bow area, and swollen fibers in the posterior cortex were observable by just 2 weeks of age. At 4 weeks of age, the appearance of the dense fibers at the bow area became more frequent, and the lenticular nucleus was formed at the center of the lens. At this time the cellular extensions of the posterior cortical fibers began to be interrupted around the posterior sutural area, which might represent a critical change. Following this change, small amounts of liquid were accumulated at the posterior subcapsular region just behind the bow area by 6 weeks of age. The lenticular nucleus was gradually shifted to a posterior location. Between 10 and 11 weeks of age, increased areas of liquefaction extended into almost all the area of the posterior subcapsular region, and as the posterior suture line separated, the opacification rapidly appeared. This animal model seems to suggest the importance of successive formation in the posterior suture.

Aging↗