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Biomedical subjects

N Ohta

Publications and source records attributed to N Ohta.

At least 253 records · Page 14Linked to original sources
PubMed1987

Immunogenetic factors involved in the pathogenesis of distinct clinical manifestations of schistosomiasis japonica in the Philippine population.

Immunogenetic factors were studied in 60 patients with schistosomiasis japonica in the Philippines, of whom 15 were characterized by marked hepatosplenic lesions and 45 characterized by cerebral symptoms. Immune responsiveness of the patients to schistosomal antigen was measured by T cell proliferation in vitro, and their HLA-A and -B specificities were typed. All but one hepatosplenic patients showed strong immune responsiveness to the schistosomal antigen, whereas both low and high responders were observed in the cerebral patients. A significant association between HLA-B40 and high responders to the schistosomal antigen was observed (P = 0.0458), and this HLA specificity was increased in frequency in the hepatosplenic patients. HLA-B16 was not observed in the hepatosplenic patients, but was common in the cerebral patients (26.5%) (P = 0.0255), and this HLA specificity was commoner in the low responders than in the high responders. These observations suggest that an HLA-linked gene governs the clinical manifestations of human schistosomiasis japonica by controlling immune responsiveness of the infected hosts to the schistosomal antigen.

Adolescent↗
PubMed1987

Protective role of renal metallothionein against Cd nephropathy in rats.

Rats were treated with four types of Cd compound: CdCl2, Cd bound (Cd-peptide), and Cd bound to metallothionein (Cd-MT). This treatment caused no nephropathy. Subsequently, toxic doses of Cd compounds were administered to these pretreated rats and their effects on renal function were examined. When 1.4 mg Cd/kg as Cd-Cys was administered, marked increases in urinary protein, glucose, and amino acid were observed. However, when the animals were pretreated with 1 mg Cd/kg/day as CdCl2 for 3 days, and 1.4 mg Cd/kg as Cd-Cys was administered 24 hr later, no renal damage was observed. Such a protective effect against the nephrotoxic action of Cd-Cys was also shown by pretreatment with Cd-Cys, Cd-peptide, or Cd-MT. Furthermore such a phenomenon was also observed when the nephropathy was caused by Cd-peptide or Cd-MT. The efficacy of pretreatment depended on the time before subsequent administration of Cd and the dose used for pretreatment. Incorporation of Cd into the liver and the kidney was not altered by the pretreatment. No matter in which form the nephrotoxic dose of Cd was administered, the incorporated Cd was distributed between particulates and cytosol; 3 hr after administration, cytosolic Cd was present in almost equal amounts in the high-molecular-weight and the MT fractions in the nonpretreated rats. However, after pretreatment, more of the Cd subsequently administered was found in the MT fraction. These results suggest that MT participates in the detoxication mechanism against Cd in the kidney, as it does in the liver.

Animals↗
PubMed1987

Operative fiberoptic nephroureteroscopy: removal of upper ureteral and renal calculi.

We tested 2 prototypes of an operating fiberoptic nephroureteroscope, measuring 3.5 and 4.5 mm. in diameter, that have an adequate working channel for auxiliary instruments and irrigation. Difficulty in passing the fiberscope through the ureteral orifice was overcome by dilation with balloon and polytetrafluoroethylene (Teflon) dilators. Our initial trial for stone retrieval under fiberscopic control was performed on 21 patients with upper ureteral and renal calculi. A stone was removed successfully in 15 of the 21 patients (71 per cent). After electrohydraulic lithotripsy calculi were extracted successfully in 9 of 11 patients (82 per cent). Three patients suffered ureteral perforation. The fiberscope was especially helpful when an upper ureteral stone moved back to the kidney during stone manipulation.

Adult↗
PubMed1987

In vitro analysis of T-cell-mediated immunity to intact eggs in murine experimental Schistosoma japonicum infection.

To characterize the mechanisms of induction and regulation of the cell population involved in granuloma formation around eggs of Schistosoma japonicum, we utilized a simple method of in vitro experiments. Lyt1+2-T cells were essential for in vitro responses to the intact S. japonicum eggs, which were assumed to be comparable to in vivo granulomatous responses. T-cell responses seemed to be macrophage-dependent, and responding T cells produced IL-2-like activities in the culture supernatant. Sera taken from chronically infected mice acted as regulatory factors to these T-cell responses as was the case in in vivo granuloma formation. The method used here was simple and highly informative for the studies on pathogenesis of schistosomiasis japonica.

Animals↗
PubMed1987

[Clinical trials of flomoxef in complicated urinary tract infections].

Flomoxef (6315-S, FMOX), a new oxacephem antibiotic was studied clinically in 27 patients with complicated urinary tract infections. FMOX was intravenously administered at a dose of 1.0 g twice daily for 5 days. Clinical effect of FMOX on patients with complicated urinary tract infections were excellent in 11.5%, moderate in 57.7% and overall clinical efficacy rate was 69.2%. During the treatment with FMOX, urticaria was observed in 1 case. In laboratory tests, a decrease of RBC, Hb and Ht in 1 case, a decrease of WBC in 1 case and an elevation of GPT in another case were observed. But these abnormal values were slight and transient.

Adult↗
PubMed1986

Tissue distribution of cadmium and nephropathy after administration of cadmium in several chemical forms.

Cadmium (Cd) was administered as CdCl2, Cd-Cys, Cd-partial structural peptide of metallothionein (MT) II, Cd-MT I, and Cd-MT II to rats, and the distribution of and nephropathy caused by the corresponding Cd compounds were examined. Each Cd complex showed dissociation of Cd in vivo and in vitro in the plasma. With Cd-Cys approximately 80% dissociation was observed while Cd-MT showed only 15% dissociation. When the dissociation of the Cd complex in the plasma was less, the distribution of Cd to the liver was decreased but distribution was increased to the kidney and urine. Each Cd complex showed the presence of Cd in the kidney shortly after the administration in the high molecular weight fraction (HM-fr) and also in MT-fr. This was then followed by a decrease in the Cd level in the HM-fr but by an increase in the MT-fr. All Cd compounds except CdCl2 caused some transient renal damage. Renal damage shown by significant increases of urinary protein, glucose, and amino acids were observed at the doses of 1.3-1.7 mg Cd/kg in the Cd-Cys group, at 0.51-0.64 mg Cd/kg in the Cd-peptide group, and at 0.16-0.23 mg/kg in the Cd-MT I and II groups. The Cd level in the kidney of rats with renal damage from these complexes was approximately the same in all the groups, that is, 10 micrograms/g kidney. It is concluded that Cd causes renal damage when its concentration in the kidney is 10 micrograms/g or higher regardless of the type of Cd complex that is administered.

Amino Acids↗
PubMed1986

NO1: an HLA-DQw1-associated determinant present on loss mutants not expressing DQw1.

We have used two monoclonal antibodies, FA and Tu39, and cloned cytotoxic T lymphocytes to study the immunogenetic control of an HLA-D region-encoded determinant(s) recognized by the Tc other than class I or DR or DQ. The Tc recognize a determinant associated with one (the A2) haplotype of LCL721 and are lytic to mutants of LCL 721 that have lost expression of all class I as well as the serologically defined DR and DQw specificities associated with, and presumably identical to, DPw2, the specificity encoded by the sensitizing (A2-B51) haplotype; these data provide the first evidence that FA recognizes the protein dimer presumably expressing the DPw determinant. Those Tc blocked by Tu39 recognized a determinant, referred to as NO1, that is not associated in the population with DPw2, but is found on some, but not all, DQw1-positive cells. We propose three possible explanations for these results. (i) There may be a class II product other than DP or those expressing the DR or DQ serologically defined specificities carrying NO1; such a product could be either as yet undescribed (E. Long has obtained information for an expressed and as yet undefined class II beta gene, personal communication) or a second expressed dimer of the DQ or DP families. (We assume that no DR genes of the A2 haplotype are expressed in these mutants. (ii) NO1 and DPw2 may be on the same molecule; to account for the lack of association of NO1 and DPw2 in the population, one might propose a mechanism such as gene conversion leading to expression of NO1.(ABSTRACT TRUNCATED AT 250 WORDS)

Antibodies, Monoclonal↗