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Biomedical subjects

T Hara

Publications and source records attributed to T Hara.

At least 739 records · Page 41Linked to original sources
PubMed1992

Panoramic specular microscopy of lens epithelial cells in the postoperative pseudophakic eye.

Using the Konan-Keeler specular microscope, panoramic specular microscopy covering almost one quadrant of the anterior capsule was performed. Regional changes in the retained lens epithelial cells were recorded and compared simultaneously. The nearer the rim of the anterior capsular opening, the greater the decrease of cell density, increase of average cell size, and variety of cell size. The results indicate that the first postoperative changes in lens epithelial cells following phacoemulsification with subsequent capsular bag intraocular lens implantation occur in the area close to the anterior capsular opening, with subsequent changes in peripheral areas.

Aged↗
PubMed1992

Two modes of homologous C3 deposition on Ramos Burkitt's lymphoma cell substrains co-expressing DAF (CD55), CD59, and CR2 (CD21), and on cells lacking them.

We established decay-accelerating factor (DAF)/CD59-positive and -negative substrains of a human B cell line, Ramos, R(DAF+/CD59+) and R(DAF-/CD59-) respectively. Unexpectedly, treatment of R(DAF+/CD59+) cells with Mg2(+)-EGTA-serum resulted in efficient C3 deposition, while treatment of R(DAF-/CD59-) cells did not. All six substrains of R(DAF-/CD59-) cells were CR2-negative, and treatment of the cells with M177 [a membrane cofactor protein (MCP) cofactor-blocking antibody] and/or acidic buffer only minimally affected the extent of C3 deposition. However, when R(DAF-/CD59-) cells were pretreated with M177 followed by incubation with low conductivity (3 mS) Mg(2+)-EGTA-serum, C3 deposition leading to effective cytolysis was provoked. On the other hand, all seven R(DAF+/CD59+) substrains were CR2-positive and could potentially induce C3 autoactivation without cytolysis under physiological conditions. Both M177 and pH again minimally affected the extent of C3 deposition. However, conductivity altered the sensitivity to C3: at under 3.0 mS, R(DAF+/CD59+) cells became almost insensitive to alternative pathway-mediated C3 deposition. Anti-CR2 partially inhibited C3 deposition on R(DAF+/CD59+) cells and C3 deposition was abrogated on the CR2-lacking R(DAF-/CD59-) cells, suggesting that CR2 was associated with the deposition of C3. These results, together with the finding that fluid phase activation of complement did not enhance C3 deposition, suggest that there are two distinct modes of spontaneous homologous C3 deposition on human lymphoma cells. In one case, CR2 or its related molecules participates in C3 deposition overcoming the protective function of DAF/MCP and this type of C3 deposition is maximized under physiological conditions. In the other case, C3 deposition is induced by another homologous C3 activator that becomes functional under low conductivity conditions and the absence of DAF/MCP. These two modes of homologous alternative pathway activation would explain the reported instances of spontaneous C3 deposition on human B lymphoid cell lines (under physiological conditions in the presence of DAF/MCP) and on paroxysmal nocturnal hemoglobinuria erythrocytes (under low conductivity conditions in the absence of DAF/MCP).

Antigens, CD↗
PubMed1992

Study on human erythrocyte thioltransferase: comparative characterization with bovine enzyme and its physiological role under oxidative stress.

Thioltransferase, an enzyme which catalyzes the thiol/disulfide exchange reaction in the presence of GSH, was purified to homogeneity on 15% SDS-PAGE from human (36,000-fold purification) and bovine (23,000-fold) erythrocyte hemolysates. These enzymes had similar properties in their monomeric structures (M(r) = 11,000) and broad specificities for substrates ranging from low-molecular disulfides (S-sulfocysteine, cystamine, and cystine) to protein disulfides (trypsin and insulin). They were highly sensitive to SH-reagents (monoiodoacetic acid and mercuric chloride), but were protected from inactivation by the presence of disulfides (GSSG, cystamine, and cystine). Phosphofructokinase and pyruvate kinase that had been inactivated by disulfides were reactivated effectively by the addition of thioltransferase with GSH. In addition, disulfides in membrane proteins of human erythrocytes that have been oxidatively damaged by diamide treatment were reduced to the SH-free form more effectively by incubation with thioltransferase.

Amino Acids↗
PubMed1992

Evaluation of cervical cord function using spinal evoked potentials from surface electrode.

Spinal evoked potentials from cervical skin surface (surface spinal evoked potentials) were measured to evaluate spinal cord function as a convenient method that precludes inserting electrodes into the epidural space, and results were compared with those of the former epidural recording method. Surface spinal evoked potentials were obtained from cervical skin surface over the C3, C5, and C7 spinous processes after median nerve stimulation in 18 normal subjects and 37 patients with a cervical lesion. In normal subjects, surface spinal evoked potentials consisted of three negative waves (N1, N2, N3). Abnormal N2 (80%) and abnormal N3 (100%) were observed in cervical myelopathy, and abnormal N2 was observed only in radiculopathy; this allows for differentiation between myelopathy and radiculopathy. Comparing preoperative and postoperative surface spinal evoked potentials, it was seen that improvement of clinical symptoms was proportional to that of surface spinal evoked potentials.

Adult↗
PubMed1992

Hepatitis E virus: cDNA cloning and expression.

Viral hepatitis E is endemic, frequently provoking epidemic outbreaks in many developing countries. We have attempted to clone the viral genome and to develop an antibody assay system. A lambda gt11 cDNA library was constructed from the bile juice containing putative causative viruses and was immunoscreened by the antisera obtained from patients and monkeys infected with hepatitis E. Three virus-specific clones were isolated and were revealed to overlap one another in sequence, with 1,459 nucleotides in total length. These clones direct the synthesis of polypeptides probably having common immunological epitope(s). Immunoplaque assay revealed the occurrence of antibodies against this epitope in the sera from experimental monkeys with the convalescent phase and from patients of Myanmar, Nepal and India. The data indicate that the cDNA fragments are useful for immunodiagnosis of hepatitis E.

Amino Acid Sequence↗
PubMed1992

Levels of complement regulatory proteins, CD35 (CR1), CD46 (MCP) and CD55 (DAF) in human haematological malignancies.

Levels of the membrane complement regulatory proteins, C3b/C4b receptor (CR1, CD35), membrane cofactor protein (MCP, CD46), and decay-accelerating factor (DAF, CD55), expressed on cells from patients with haematological malignancies and normal subjects were assessed by flowcytometry using the respective monoclonal antibodies (mAbs). All myeloid and most lymphoid leukaemia samples tested were CR1-negative: two of the 42 leukaemia samples expressed minute amounts of CR1. Lack of CR1 in leukaemia cells was confirmed with two mAbs raised against CR1, 31R, and 243R, which recognized different epitopes and induced different degrees of CR1-mediated fluorescent shift on flow-cytometry in granulocytes and erythrocytes. MCP was increased in most chronic myelogenous leukaemia (CML) and chronic lymphocytic leukaemia (CLL), and was also increased in majority of acute nonlymphocytic leukaemia (ANLL), acute lymphocytic leukaemia (ALL) and non-Hodgkin's lymphoma (NHL). Levels of DAF were also high in CML and CLL, and were variable in other types of leukaemia: some were DAF-negative while others expressed extremely high levels of DAF. In CML patients, the high level of MCP and the lack of CR1 were normalized after medical treatment. These results are in agreement with the data obtained with human leukaemia cell lines, and support the hypothesis that CR1 is essentially a differentiated cell antigen and that a high level of MCP reflects some malignant transformation or an immature stage in blood cells.

Antibodies, Monoclonal↗
PubMed1992

Soluble forms of membrane cofactor protein (CD46, MCP) are present in plasma, tears, and seminal fluid in normal subjects.

We have established an ELISA for determination of membrane cofactor protein (MCP, CD46) both solubilized from cell membranes and released in body fluids. In this assay, mouse MoAbs against MCP, M177 and M160 whose epitopes were different, were used as capture and detection antibodies, respectively. The NP-40 concentration in samples for MCP to be measured must be less than 0.05%. The detection limit of this MCP assay was 0.5 ng. The assay was used to quantify solubilized membrane MCP, and soluble MCP in normal human plasma, serum, urine, saliva, tears, and seminal fluid, and culture media of tumour cell lines. Soluble MCP was barely detected in the conditioned media of the cell lines. The levels of sMCP in plasma and serum were 10-60 ng/ml and that in tears, 0-50 ng/ml. Seminal fluid contained about 10-fold more soluble MCP than serum. Soluble MCP was not detectable by this assay in the other body fluids, suggesting that their MCP levels were less than the detection limit, if any.

Anticoagulants↗
PubMed1992

The role of thyroid stimulating antibody (TSAb) in the thyroid function of patients with post-partum hypothyroidism.

OBJECTIVE: We investigated the association between thyroid function and the biological activities of thyroid stimulating antibodies (TSAb) and thyroid stimulation blocking antibodies (TSBAb) in patients with post-partum hypothyroidism. DESIGN: A prospective study. PATIENTS: We studied 25 patients with post-partum hypothyroidism who visited our thyroid clinic during the period from 1985 to 1990. MEASUREMENTS: We measured TSH binding inhibitory immunoglobulin (TBII) and TSAb activity at the initial presentation of each of the 25 patients. Women found to have elevated TSAb activity were followed up. Upon finding negative TSAb activity along with positive TBII activity in the serum at the initial presentation, we measured TSBAb activity. Women found to have elevated levels of TSBAb at the initial presentation were also followed up. RESULTS: Elevated TBII activity was found in six of the 25 patients, as was high TSAb activity (205-2651%, normal 55.0-145.0%) in five of these six and in one other patient at the initial presentation. Markedly elevated TSBAb activity (89%) was found in one TBII positive patient. We were able to follow up serially five TSAb positive patients and the TSBAb positive patient over periods ranging from 11.5 to 26.5 months post-partum. The maximal value of TSAb activity was observed at the initial presentation in all TSAb positive patients, following which the activities gradually decreased. One of these patients developed Graves' hyperthyroidism associated with high TSAb activity (1223%) at 10.5 months post-partum. One of the other patients was restored to euthyroid with elevated TSAb activity (279%), but thereafter developed hypothyroidism in conjunction with the disappearance of TSAb activity at 26.5 months post-partum. In the other two patients, normalization of thyroid function was observed with elevated TSAb activity. Thereafter, thyroid function remained within the normal range even with the disappearance of TSAb activity. In the other patient, normalization of thyroid function was observed at 11.5 months post-partum, 3 months after the disappearance of TSAb activity. In the TSBAb positive patient, TSBAb activity decreased to 21% by 17.5 months post-partum associated with normalization of thyroid function. CONCLUSION: The present study demonstrates the presence of elevated levels of TSAb activity in some patients with post-partum hypothyroidism. In these patients, Graves' hyperthyroidism may be induced by TSAb activity, and hypothyroidism may reoccur with the disappearance of the TSAb activity. Furthermore, post-partum hypothyroidism may be due to increased TSBAb activity in some patients.

Antibodies↗
PubMed1992

T cell activation and T cell receptor variable region gene usage in measles.

T cell activation and T cell receptor variable (V) regions were studied with monoclonal antibodies in peripheral blood lymphocytes from 22 patients with measles. Increased (greater than 5%) activated T cells (HLA-DR+ CD3+ cells) were noted in 14 of the 22 patients. Elevations of V beta 5+ and V beta 8+ T cells were observed in two and four patients, respectively, and appeared to be associated with T cell activation. The duration of fever was significantly prolonged in those with increased (greater than 10%) activated T cells (p less than 0.01). These results suggest that T cell activation and the preferential expansion of V beta 8+ and V beta 5+ T cells are associated with the pathogenic process of measles.

Adolescent↗
PubMed1992

Pregnancy alters the hemodynamic responses to cocaine in the rat.

To test our hypotheses that the hemodynamic response to cocaine may be altered during pregnancy, cocaine (0.33 mg/kg/min) was infused intravenously to chronically catheterized pregnant and nonpregnant female rats. Cardiac output and regional blood flow were measured, and cocaine concentrations in plasma and tissues, as well as plasma cholinesterase activity were determined. Results were compared between pregnant and nonpregnant groups. Cocaine produced a significant decrease in heart rate, accompanied by a fall in cardiac output, and decreased cerebral, myocardial, and placental blood flow in pregnant rats. The plasma cocaine concentration in pregnant animals was lower than that of nonpregnant ones, but tissue concentrations were similar in both groups. These results indicate that pregnancy enhances cardiovascular responses to subtoxic doses of cocaine. There was little placental transfer of cocaine with a fetal to maternal plasma concentration ratio of 0.28.

Animals↗
PubMed1992

Predominant activation and expansion of V gamma 9-bearing gamma delta T cells in vivo as well as in vitro in Salmonella infection.

Gamma delta T cell receptor-positive cells (gamma delta T cells) have recently been implicated to play a role in the protection against infectious pathogens. Serial studies on gamma delta T cells in 14 patients with salmonella infection have revealed that the proportions of gamma delta T cells (mean +/- SD: 17.9 +/- 13.2%) in salmonella infection were significantly increased (P less than 0.01) compared with 35 normal controls (5.0 +/- 2.6%) and 13 patients with other bacterial infections (4.0 +/- 1.4%). Expansion of gamma delta T cells was more prominent in the systemic form (28.9 +/- 10.8%) than in the gastroenteritis form (10.5 +/- 7.9%) of salmonella infection (P less than 0.01). Most in vivo-expanded gamma delta T cells expressed V gamma 9 gene product. Increased activated (HLA-DR+) T cells were observed in all the six patients with the systemic form and four of the seven with gastroenteritis form. Especially in the six with systemic form, gamma delta T cell activation was significantly higher than alpha beta T cell activation at the early stage of illness (P less than 0.01). When peripheral blood lymphocytes from normal individuals were cultured with live salmonella, gamma delta T cells were preferentially activated and expanded and most of them expressed V gamma 9. Purified gamma delta T cells also responded to live salmonella in vitro. The present study suggests that human gamma delta T cells play a role in the protection against salmonella infection in vivo.

Adolescent↗
PubMed1992

Open total dislocation of the talus with extrusion (missing talus): report of two cases.

Two different methods of treatment for open dislocation of the extruded talus without soft tissue attachments (missing talus) were examined. In case 1, a 20-year-old man sustained an open total dislocation of the talus due to a motorcycle accident. The missing talus was found within 3 hr and replaced after thorough washing and debridement. Weightbearing was permitted at 20 weeks; however, the density of the talar body increased in the x-ray and nonweightbearing status was resumed. Reexamination at 2 1/2 years revealed that there was joint space narrowing on the x-ray and decreased pain with ambulation; the patient had returned to his job. In case 2, a 26-year-old man sustained an open total dislocation of the talus with a severe crush wound and impaired circulation to the foot. After thorough washing and debridement of the wound, the calcaneus and distal end of the tibia were aligned. The missing talus was found 3 days later, but not replaced. Weightbearing was allowed on the affected foot at 2 months; however, the patient felt pain at the joint surfaces and arthrodesis was consequently performed. At 2 1/2 years, the patient had a 4.0-cm leg length discrepancy in the involved extremity, but felt no pain when walking. Although reduction of the talus is ideal to preserve function and length of the extremity, several complications can occur. A review of literature on open total dislocation of the talus with extrusion was performed.

Adult↗
PubMed1992

Dihydrotestosterone accumulation in genital skin fibroblasts derived from elderly men with prostatic hyperplasia.

The conversion of testosterone to dihydrotestosterone (DHT) by 5 alpha-reductase and the interconversion between DHT and 5 alpha-Androstane-3 alpha,17 beta-diol (3 alpha-diol) by 3 alpha-hydroxysteroid oxidoreductase (3 alpha-HSOR) were studied in fibroblasts derived from the genital skin of 15 prepubertal boys (2-10 yr), 17 young men (20-40 yr), 13 elderly men (60-78 yr) without clinically evident prostatic pathology, and 17 elderly men (61-88 yr) with benign prostatic hyperplasia (BPH). Respective DHT formations from testosterone (5 alpha-reduction) and 3 alpha-diol (3 alpha-HSOR oxidation) were not different among genital skin fibroblasts of the 4 groups. However, DHT degradation to 3 alpha-diol (3 alpha-HSOR reduction) was significantly lower in fibroblasts from elderly men with BPH than in those from the prepubertal boys (P less than 0.01), the young men (P less than 0.01), and the elderly men without BPH (P less than 0.05). 3 beta-HSOR reduction in fibroblasts of the BPH group was significantly lower (P less than 0.05) than in those of the elderly men without BPH; however, it did not differ from values for the prepubertal boys and the young men. (3 alpha + 3 beta)-HSOR reduction was also significantly lower (P less than 0.05) in the BPH group than respective values of the three other groups. These results indicate that DHT accumulation may occur in genital skin fibroblasts from elderly men with BPH, resulting from a shift in the overall balance of androgen metabolism, which favors the net formation of DHT.

Aged↗
PubMed1992

Sequence analysis of replication origin of plasmid pLS11 of Bacillus subtilis IFO 3022.

The structure of a 1.6-kb SphI-HindIII DNA sequence necessary and sufficient for the replication of a 8.6-kb plasmid pLS11 of Bacillus subtilis IFO 3022, which is responsible for gamma-polyglutamate production, has been characterized by using a trimethoprim (Tmp)-resistance gene derived form B. subtilis TTK24 chromosomal DNA as a selective marker. The 1.6-kb DNA sequence contains a rep gene encoding the protein (333 amino acids) essential for initiation of replication and a possible origin of replication. The predicted REP protein of pLS11 has an overall homology with the REP proteins of pUH1 (74.8% identity), pBAA1 (92.8%), and pFTB14 (78.7%) in Bacillus spp., pLP1 (42.1%) and pLAB1000 (36.3%) in Lactobacillus spp., and pUB110 (35.3%) and pC194 (37.4%) in Staphylococcus aureus, but has not any similarity with the REP protein of the staphylococcal plasmid pT181.

Amino Acid Sequence↗
PubMed1992

[Incidence of renal cell carcinoma in Chiba Prefecture, Japan; ten years experience].

Many reports about the increase of renal cell carcinoma patients have been published in Japan recently, however, the real fluctuations in the total number of patients in relation to the change of population have not been reported yet. Most of the patients with renal cell carcinoma in the last 10 years were examined in Chiba prefecture, which has a population of about five million and 25 active urological offices. Histologically confirmed cases were investigated by sending questionnaire letters. The items were as follows; sex, age, address, occupation, family history, past history, symptoms, examination methods that first detected the tumor, operation date, tumor diameter and clinical stage. Twenty two offices returned answers and 560 cases who lived in Chiba were found to have renal cell carcinoma from 1980 to 1989. Yearly incidence rates per 100,000 persons demonstrated a significant increase from 0.32 to 2.07. Small, asymptomatic and low stage cancers have been increasing rapidly, however, the rate of metastatic disease has not shown any decrease. The main cause of rapid increase seems to be attributed to progress in diagnostic methods and increase of early detection, but the possibility of an increase in some carcinogenic factors can not be ruled out.

Adult↗