Biomedical subjects

H Nitta

Publications and source records attributed to H Nitta.

147 records · Page 9Linked to original sources

PubMedDate not supplied

Respiratory health associated with exposure to automobile exhaust. II. Personal NO2 exposure levels according to distance from the roadside.

We have conducted several studies to investigate the effect of automobile exhaust on respiratory symptoms. This study was designed to explore differences in personal exposure levels among residents of zones located varying distances from trunk roads with heavy traffic in Tokyo. Personal nitrogen dioxide (NO2) concentration levels for residents and NO2 concentrations inside and outside the residences of each study participant were measured during ten seasons over three years. Three residential zones were determined as follows: Zone A was 0-20 m from the roadside; Zone B was 20-150 m; and Zone C, a reference zone, was a residential district in a suburban area. Approximately fifty residents were selected as the subjects of NO2 measurements. Study participants were female, between 40 and 60 years of age, and nonsmokers. All participants used gas cooking stoves with electric ignition. Outdoor NO2 concentrations in Zone A were always the greatest among the three zones during the study periods, and those in Zone C were consistently the lowest. Personal exposure levels in Zone A were generally higher than those in the other zones, and concentrations in Zone C were the lowest during seasons when no indoor heating was used. The highest mean values for personal exposure levels in Zones A, B, and C were 63.4, 61.0, and 55.3 ppb, respectively. In analyses in which participants were stratified by heater type, the mean personal exposure levels in Zone A were the highest and the levels in Zone C were the lowest for participants without unvented heaters; differences of NO2 levels between Zones A and C ranged from 10.0 to 23.9 ppb. When there were no indoor NO2 sources except gas cooking stoves, both indoor and personal levels of NO2 were attributable primarily to motor vehicle exhaust. In contrast, the use of unvented heaters during the heating seasons could cause NO2 exposures comparable to those attributable to motor vehicles.

Adult↗

PubMedDate not supplied

Mouse epididymal sperm contain active P450 aromatase which decreases as sperm traverse the epididymis.

Recently we reported that mouse germ cells in the testis contain active P450 aromatase (P450arom), the enzyme that converts androgens to estrogens. This finding suggested that germ cells have the ability to produce estrogen. Further studies have shown that germ cells in the testis of several species contain P450arom. The goal of this study was to determine if epididymal sperm contain P450arom and if P450arom activity in sperm changes during traversion of the epididymis in the adult mouse. P450arom was localized in sperm present in the efferent ductules and epididymis by immunocytochemistry using an antiserum generated against purified human placental cytochrome P450arom. P450arom immunostaining in sperm was most prominent in sperm located in the proximal caput epididymis, decreased as sperm traversed the corpus epididymis, and was only slightly apparent in sperm in the cauda epididymis. The immunolocalization of P450arom in epididymal sperm was supported by the measurement of P450arom activity in sperm by the 3H2O assay. We found that P450arom activity in sperm significantly decreases as sperm traverse the epididymis. Based upon these observations, we conclude that sperm can synthesize estrogen and that the synthesis of estrogen by sperm present in the efferent ductules and caput epididymis could be important in the process of sperm maturation.

Animals↗

PubMedDate not supplied

Sweet's syndrome associated with granulocyte colony-stimulating factor.

We present two patients who developed Sweet's syndrome (SS) during recombinant granulocyte colony-stimulating factor (G-CSF) treatment. Case 1 : on day 11 of the fifth cycle of G-CSF treatment, a 21-year-old man with relapsed, intracranial germ cell tumor had fever, and painful, subcutaneous nodules on his right arm and right leg concomitant with neutrophilia. Skin biopsy revealed neutrophilic panniculitis. The skin lesions disappeared completely after discontinuance of G-CSF. Case 2 : on day 7 of G-CSF treatment, a 50-year-old woman with small cell lung cancer developed fever, and widely disseminated pruritic erythema on her trunk and extremities. The histopathology of the skin was compatible with SS. Her skin lesions also disappeared after discontinuance of G-CSF treatment. She subsequently received three cycles of additional G-CSF treatments without recurrence of SS. It is possible that G-CSF treatment accidentally induced or augmented the proliferation and differentiation of clonal neutrophils with abnormal functions, since in the cases presented SS developed only once in spite of several treatments with G-CSF.

Adult↗