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Biomedical subjects

N Kuroda

Publications and source records attributed to N Kuroda.

At least 163 records · Page 9Linked to original sources

Morphological characteristics of the life cycle of resting cartilage cells in mouse rib investigated in intrasplenic isografts.

Resting cartilages taken from 2-day-old mouse ribs were transplanted into spleens in order to carry out morphological investigations of the life cycles of their chondrocytes. The explants were isografted for periods of up to 60 days and examined at light and electron microscopic levels, using von Kossa's reaction or osmium-potassium ferrocyanide (OPF) fixation. By day 3 after transplantation, resting cartilage containing immature chondrocytes was well adapted to splenic tissue and by 7 days after transplantation these chondrocytes had changed into early hypertrophic chondrocytes containing large vacuoles, glycogen aggregates and abundant secretory organelles. It was also demonstrated by von Kossa's reaction that the initial calcification occurred in the territorial matrix during this period. In spite of the hypertrophic chondrocytes in the central zone being surrounded by an extensively calcified matrix during days 14-21 after transplantation, these cells had well-preserved organized organelles, except that Golgi-associated elements and endoplasmic reticulum revealed a tendency toward degenerative changes. With increased duration of the grafting period, from 30-60 days, the calcification zone progressed gradually, and the number of hypertrophic chondrocytes embedded in the calcified matrix decreased considerably. By day 60, degenerating hypertrophic chondrocytes of two types were distinguished:flattened cells containing large vacuoles, poorly developed Golgi apparatuses, and rough endoplasmic reticulum; and shrunken dark cells displaying terminal hypertrophy. During the present study, we observed no vascular invasion into the calcified matrix, or appearance of bone-related cells, and the morphological changes from the resting chondrocytes to cellular hypertrophy accompanied by the formation of a calcified matrix were observed at day 60. These findings indicate that resting cartilage cells of the mouse have the capacity for terminal differentiation when transplanted into the spleen.

Animals↗

Linear antigenic regions of the structural proteins of human T-cell lymphotropic virus type I detected by enzyme-linked immunosorbent assays using synthetic peptides as antigens.

We synthesized 46 sequential peptides 21 to 39 amino acids long over the structural protein of human T-cell leukemia virus type I (HTLV-I; the p19 and p24 gag protein and the gp46 and p20E env proteins) and tested their reactivities against antibodies in sera from HTLV-I healthy carriers and patients diagnosed as having human T-cell leukemia-lymphoma (ATLL) and myelopathy (HAM) by using an enzyme-linked immunosorbent assay. Of the 46 synthetic peptides, 18 peptides (2 corresponding to the p19 gag protein, 2 corresponding to the p24 gag protein, 8 corresponding to the gp46 env protein, and 6 corresponding to the p20E env protein) reacted with antibodies in the sera from HTLV-I healthy carriers. In particular, the peptides comprising amino acids 100 to 119 and 119 to 130 of the gag and 175 to 199, 213 to 236, 253 to 282, and 288 to 317 of the env proteins reacted with antibodies in sera from more than 30% of HTLV-I healthy carriers. These peptides also showed high reactivities to the antibodies in the sera from patients with ATLL and HAM. The results indicate that the predominant antigenic regions of the structural protein of HTLV-I were located at the C-terminal end of the p19 gag protein and the C-terminal half of the gp46 env protein, and the corresponding peptides proved to be useful antigens in detecting antibodies in the sera from individuals infected with HTLV-I.

Amino Acid Sequence↗

A case of homicidal choking mistaken for suicide.

This report presents an autopsy case of the homicidal choking of an adult, who died as a result of tissue paper being thrust into his mouth. An in-patient (a 29-year-old Japanese man) at a mental hospital was choked to death by another male in-patient, his roommate, who thrust a large amount of tissue paper into his mouth after rendering him slightly unconscious by cervical compression. At the time of discovery, this mental patient was believed to have committed suicide by inserting tissue paper into his own mouth. Autopsy findings and re-investigation of the case revealed that the subject had been murdered. This is a very rare case of choking used as a method of homicide.

Adult↗

Morphological modifications during long-term survival of Meckel's cartilage hypertrophic chondrocytes transplanted in the mouse spleen.

To examine the ultimate fate of hypertrophic chondrocytes, Meckel's cartilage bars from 18-day-old mouse embryos were transplanted into isogenic mouse spleen for 3, 7, 14 and 21 days and observed at the light and electron microscopic levels. The midportions of these Meckel's cartilage bars were used as explants; they were characterized by many hypertrophic chondrocytes containing euchromatic round nuclei, a large amount of glycogen particles, and some vacuoles. Grafted cartilage adapted well to the splenic tissue, showing intense metachromasia around the territorial matrix. Ultrastructural observations indicated that the number of large vacuoles and glycogen aggregates in the hypertrophic cells became markedly reduced with grafting time, whereas the Golgi apparatus and rough endoplasmic reticulum were well-developed. Needle-like crystals showing initial apatite deposition appeared in association with matrix vesicles; these proliferated as time elapsed after transplantation. On day 14 after transplantation, cells displaying such various structural features as pyknotic nuclei, large vacuoles, and cytoplasmic shrinkage were noted in addition to intact hypertrophic chondrocytes. Following resorption of the calcified cartilage by multinucleated giant cells, many osteoblasts appeared along the border of the calcified matrix. Some remaining hypertrophic cells in the calcified matrix had transformed into osteocyte-like cells. On day 21, the resorbed area of the calcified cartilage was invaded by many blood vessels. Hypertrophic chondrocytes, now exposed from cellular lacunae, and the osteocyte-like cells in the calcified matrix displayed involutional changes. The present study showed that, although the hypertrophic chondrocytes in Meckel's cartilage essentially underwent regressive changes, they retained the ability to stimulate endochondral ossification within the microenvironment of the spleen. In addition, some of these cells were transformed into osteocyte-like cells.

Animals↗

Serological and biochemical studies on En(a-) human erythrocytes in a Japanese family.

The propositus erythrocytes with phenotype En(a-), which was found in the first example of a Japanese family, reacted with anti-N serum weaker than the ordinary phenotype N erythrocytes. When the erythrocyte membranes of the propositus were subjected to SDS-PAGE, no glycophorin A was observed on the gel by PAS staining, whereas glycophorin B band was observed. The S and the s antigens of the propositus erythrocytes were appeared to be normal. These results suggested that N activity of the propositus erythrocytes may be derived from glycophorin B components on the erythrocyte membranes. The amounts of bound sialic acid of the erythrocyte membranes were significantly lower in the En(a-) erythrocytes than the ordinary OMN erythrocytes. Neither the OMN nor the En(a-) erythrocytes showed the agglutinability to Arachis hypogaea lectin. The number of lectin receptor sites on the En(a-) erythrocyte membranes was significantly lower than on the OMN erythrocyte membranes for Limulus polyphemus, Triticum vurgaris and Bauhinia purpurea lectins. These results provide further support for the contention that En(a-) cells lack the glycophorin A as major erythrocytes sialoglycoprotein on the membranes.

Asian People↗

[Attempt for modified radical mastectomy in the treatment of early breast cancer].

Until five years ago the Aichi Cancer Center had adopted the standard radical mastectomy where breast, major and minor pectoral muscles, and axillary adipose tissues were resected en bloc. In case tumor was found at the inner half or the center of the breast, parasternal lymph node dissection was concomitantly carried out. Recently, however, we begin to perform Auchincloss by which major and minor pectoral muscles can be conserved, as an attempt for modified radical mastectomy. In some cases, furthermore, breast conserving operation is made. The reasons why we changed the operation methods are: 1) Due to the advancement of diagnostic imaging and widespread self examination, percentage of early breast cancer has considerably increased. 2) Postoperative adjuvant therapy, especially adjuvant endocrine therapy, has remarkably progressed.

Breast Neoplasms↗

Enzyme immunoassay with synthetic peptides to detect anti-HTLV-I antibodies.

We developed an enzyme immunoassay (EIA) system to detect antibodies to human T-lymphotropic virus type I (HTLV-I). This system uses chemically synthesized oligopeptides to capture anti-HTLV-I antibodies in serum. The two epitopes of HTLV-I proteins exhibiting the most specific antigen-antibody reaction reside within amino acids 100-130 of p19, a core protein encoded by gag, and amino acids 175-199 of gp46, an envelope glycoprotein encoded by env. This new assay uses synthetic peptides corresponding to these two regions modified by adding two lysine residues at the amino terminal of each peptide to facilitate the binding to the surface of the microtiter plate wells. We compared the performance of our EIA with gelatin-particle-agglutination (PA) and indirect-immunofluorescence (IF) assays, both of which use viral proteins purified from virus-carrying cell cultures. Mass screening by EIA with various synthetic peptides was more accurate than the current confirmatory IF assay.

Agglutination Tests↗

Serological discrimination between HTLV-I and HTLV-II antibodies by ELISA using synthetic peptides as antigens.

Using the peptides from amino acids 100-130 of the HTLV-I gag protein, 175-199 of the HTLV-I env protein and the corresponding peptides of HTLV-II (amino acids 106 to 135 of the gag protein and 171 to 196 of the env protein), we tested for reactivity against antibodies by enzyme immunoassay in sera from HTLV-I and HTLV-II carriers. The peptides derived from the env proteins have high specificity for antibody binding. The peptide based on amino acids 175-199 of HTLV-I reacted with antibodies in sera from all HTLV-I carriers, and the peptide composed of amino acids 171-196 of HTLV-II reacted with antibodies in sera from all HTLV-II carriers. For the peptides derived from the gag proteins, we observed some cross-reactivity in sera from persons with anti-HTLV-I and anti-HTLV-II, due to antibody binding to the peptide corresponding to 12 amino acids from the C-terminal end of the gag protein. Separate enzyme immunoassays that used the four synthetic peptides as antigens clearly distinguished between serum with antibodies to HTLV-I or HTLV-II in various individuals and excluded false positive results using the particle agglutination assay that used a whole-virus lysate of HTLV-I as antigen.

Amino Acid Sequence↗

Elevated antibodies to synthetic peptides of HTLV-1 envelope transmembrane glycoproteins in patients with HAM/TSP.

We studied the antibody response to various kinds of well-characterized synthetic peptides of human T lymphotropic virus type 1 (HTLV-1) envelope glycoproteins in patients with HTLV-1 associated myelopathy (HAM)/tropical spastic paraparesis (TSP) and non-HAM/TSP HTLV-1 carriers. The serum antibody titers to most of the synthetic peptides were significantly higher in patients with HAM/TSP than those in non-HAM/TSP HTLV-1 carriers. However, the degree of the increase of antibody titers to the synthetic peptides corresponding to the transmembrane portions of HTLV-1 envelope glycoproteins (env-p20E), such as p20E 332-352, 374-392, 426-448 and 458-488, was greater than those to synthetic peptides of exterior portions of HTLV-1 envelope glycoproteins (env-gp46) in sera from patients with HAM/TSP. Antibodies to env-p20E 332-352 and 374-392 were elevated in the cerebrospinal fluid (CSF) only from patients with HAM/TSP but not from non-HAM/TSP HTLV-1 carriers. These data indicate that the increase of antibody titers to transmembrane portions of HTLV-1 envelope glycoproteins in sera and CSF is a characteristic feature of antibody response in patients with HAM/TSP and may be closely associated with the development of HAM/TSP from non-HAM/TSP HTLV-1 carriers.

Adult↗

Identification and mapping of neutralizing epitopes of human parvovirus B19 by using human antibodies.

We identified and mapped the regions responsible for neutralization in the human parvovirus B19 structural protein by using region-specific human antibodies derived from seropositive blood donors. The region-specific antibodies were purified by using affinity columns coupled with synthetic peptides of the hydrophilic regions including the beta-turn structure deduced by the predicted secondary structure of VP2. Fifteen highly specific antibodies against the synthetic peptides were obtained. Ten of them were able to precipitate the radiolabeled virus. Six of them proved to be able to protect the colony-forming unit erythroid cells in human bone marrow cell cultures from injury by the virus. The sequences recognized by the six neutralizing antibodies were sites corresponding to amino acids 253 to 272, 309 to 330, 325 to 346, 359 to 382, 449 to 468, and 491 to 515 from the amino-terminal portion of VP2. These observations suggest that the neutralizing epitopes were distributed in the region from amino acid 253 in the amino-terminal portion of VP2 to the carboxyl terminus of VP2.

Amino Acid Sequence↗

Identification of the region including the epitope for a monoclonal antibody which can neutralize human parvovirus B19.

In this study, we identified a region in the human parvovirus structural protein which involves the neutralization of the virus by a monoclonal antibody and site-specific synthetic peptides. A newly established monoclonal antibody reacted with both viral capsid proteins VP1 and VP2. The epitope was found in six strains of independently isolated human parvovirus B19. The monoclonal antibody could protect colony-forming unit erythroid in human bone marrow cell culture from injury by the virus. The monoclonal antibody reacted with only 1 of 12 peptides that were synthesized according to a predicted amino acid sequence based on nucleotide sequences of the coding region for the structural protein of B19 virus. The sequence recognized by the antibody was a site corresponding to amino acids 328 to 344 from the amino-terminal portion of VP2. This evidence suggests that the epitope of the viral capsid protein is located on the surface of the virus and may be recognized by virus-neutralizing antibodies.

Amino Acid Sequence↗

Generation and characterization of monoclonal antibodies against multiple epitopes on the C-terminal half of envelope gp46 of human T-cell leukemia virus type-I (HTLV-I).

In order to study the antigenicity of envelope 46 kDa glycoprotein (gp46) of human T-cell leukemia virus type-I (HTLV-1), we have generated monoclonal anti-gp46 antibodies (MAbs), REY-7, REY-11, REY-16, REY-30, MET-2 and MET-3 from rats and mice. Immunoblot and immunofluorescence assays showed that these MAbs recognize gp46 and its related antigens, and specifically stained HTLV-I-bearing cells. All MAbs reacted with a recombinant gp46 antigen, N147, expressing the 147 amino acids in the C-terminal half of gp46. By using various synthetic peptides corresponding to the gp46 sequence, epitopes recognized by REY-7 and MET-3, REY-11 and REY-16, and REY-30 were mapped to regions corresponding to the amino acids 175-199, 253-282 and 288-312, respectively. MET-2 did not react with any of the peptides used. These results indicate that the present MABs are directed against at least 4 distinct epitopes expressed on the C-terminal half of gp46. The binding of these MAbs to gp46 was specifically inhibited by sera from HTLV-I-infected individuals, but none of these MAbs inhibited the cell fusion activity of HTLV-I.

Animals↗

Detection of antibodies to human T-lymphotropic virus type I by using synthetic peptides.

We describe an enzyme-linked immunosorbent assay (ELISA) for antibodies to HTLV-I using synthetic peptides corresponding to antigenic regions of HTLV-I structural protein. We observed that the peptides amino acid 100-119, 100-130, 131-160 and 295-314 of the gag protein, and 89-115, 175-199, 350-386 and 458-488 on the env protein correspond to the antigenic regions of HTLV-I structural protein. In particular, the peptide corresponding to amino acid 100-130 of the gag protein reacted with antibodies in all sera from HTLV-I carriers diagnosed by particle agglutination assay (PA) and indirect immunofluorescence assay (IF), but did not react with sera from healthy volunteers judged to be negative by PA and IF. Our results indicate that the ELISA using the peptide 100-130 of the gag protein can be used for donor screening of HTLV-I antibodies.

Amino Acid Sequence↗

Relationship between age and autonomic neuropathy in diabetes mellitus.

The influence of age on diabetic autonomic neuropathy was studied. In the present study autonomic neuropathy was assessed by cardiac beat-to-beat variation during deep breathing (BBV) and pupil area prior to photic stimulus (A1). In the studies on BBV a total of 440 subjects (11-82 years in age) were divided into three groups: those with a duration of diabetes of less than 5 years and without obvious diabetic complications; those with a duration of diabetes of longer than 5 years and with diabetic complications; and non-diabetic, healthy subjects. The relationship between BBV and age was examined in each group. In the studies on A1 a total of 101 subjects (22-75 years in age) were investigated in the same way. The results were as follows: (1) The autonomic nerve function of young diabetics corresponds to that of old non-diabetics in terms of cardiac beat-to-beat variation and pupil area prior to photic stimulus; (2) in young diabetics duration of diabetes and the complications influence the autonomic nerve function; (3) autonomic nerve function is related to age. Age is more influential than duration of diabetes and diabetic complications, especially in the older subjects.

Adult↗

Lack of favorable effect of immunomodulators on outbred syngeneic rodent islet transplantation.

We studied the effect of two immunomodulators, lobenzarit disodium and OK-432, on outbred syngeneic islet transplantation. Six hundred fresh islets taken from two male Wistar rats were transplanted intraportally into other male Wistar rats that had been made diabetic with streptozotocin. Lobenzarit was given to 12 recipients and OK-432 to seven recipients intraperitoneally for 1 month, while nine controls received only intraperitoneal saline. Both drug-treated groups could not maintain lower fasting plasma glucose levels or higher fasting body weights at each time as compared with controls. The islet survival time in lobenzarit-treated (23.5 +/- 8.0 days) and OK-432-treated (25.3 +/- 13.4 days) groups was not longer than that (21.6 +/- 9.4 days) of the control group. All the pancreatic insulin contents of the seven surviving controls, ten surviving lobenzarit and five surviving OK-432 recipients were less than 0.8% of the mean insulin content obtained from 12 normal male rats. The hepatic insulin content of both drug-treated groups was not higher than that of the control group. These results suggest that lobenzarit disodium and OK-432 cannot protect outbred syngeneic islet grafts.

Adjuvants, Immunologic↗