Biomedical subjects

S Maeda

Publications and source records attributed to S Maeda.

At least 19 recordsLinked to original sources

PubMed1992

Analysis by mutagenesis of the ATP binding site of the gamma subunit of skeletal muscle phosphorylase kinase expressed using a baculovirus system.

Active gamma subunit of skeletal muscle phosphorylase kinase has been obtained by expression of the rat soleus cDNA in a baculovirus system. The protein exhibited the expected pH 6.8/8.2 activity ratio of 0.6, and its activity was insensitive to Ca2+ addition, indicating that it was free gamma subunit and not a gamma subunit-calmodulin complex. It was stimulated approximately 2-fold by Ca(2+)-calmodulin addition, demonstrating that it had retained high-affinity calmodulin binding. By site-directed mutagenesis, we have examined the role of six of the amino acids that constitute the consensus ATP binding site of the protein kinase, which in the gamma subunit is represented by the sequence 26Gly.Arg.Gly.Val.Ser.Ser.Val.Val33. Changes were evaluated by the kinetic determination of the dissociation constants of gamma-ATP, gamma-ADP, gamma-AMP.PCP, and gamma-phosphorylase and the maximum catalytic activity. The mutants Ser26-gamma, Ser29-gamma, Phe30-gamma, and Gly31-gamma each exhibited an essentially identical dissociation constant for gamma subunit phosphorylase, indicating that these mutations had not caused a global alteration in the protein structure but were limited to changes in the nucleotide binding site domain. Substitution of either Val33 (by Gly) or Gly28 (by Ser), two of the most conserved residues in all protein kinases, resulted in enzyme with marginally detectable activity. In noted contrast, the Ser26 mutant, which substituted the first glycine of the consensus glycine trio motif, and which is also very highly conserved, retained at least 25% of the enzymatic activity. The Gly31 substitution, which restored a glycine to a position characteristic for most protein kinases, had little overall effect upon the maximum rate of catalysis. Restoration of Ser30 to the more typical phenylalanine, which is present in most protein kinases, had minimal effect on catalysis. These data provide the first direct evaluation of the roles that different residues play within this consensus glycine trio/valine motif of the protein kinases, which up to now have only been surmised to be of importance because of their conservation. Two unexpected findings are that for one residue that is very conserved (Gly26) there is some flexibility of substitution not apparent from the evolutionary conservation and that a second quite conserved residue in protein kinases (equivalent to Gly at position 31) does not produce a protein optimized for nucleotide binding.

Adenosine Triphosphate↗

PubMed1992

A novel transthyretin mutation at position 30 (Leu for Val) associated with familial amyloidotic polyneuropathy.

A novel transthyretin (TTR) mutation associated with familial amyloidotic polyneuropathy was detected in a Japanese patient. Single-strand conformation polymorphism analysis and sequence analysis of polymerase chain reaction (PCR)-amplified exons of the patient's TTR gene revealed a point mutation resulting in a substitution of leucine for valine at position 30. As the mutation creates a Cfr13I site, it was confirmed by PCR and restriction analysis. Our finding indicates the importance of position 30 in TTR-derived amyloid fibril formation.

Amyloidosis↗

PubMed1992

Immunohistochemical evaluation of parathyroid hormone-related protein (PTHrP) in the uterine cervix.

We investigated the immunohistochemical localization of parathyroid hormone-related protein (PTHrP), a major factor responsible for the humoral hypercalcemia of malignancy, in uterine cervical lesions. Formalin-fixed paraffin-embedded specimens from 16 cases of normal and reactive conditions, 45 cases of cervical intra-epithelial neoplasm (CIN) and 63 cases of invasive cancer were studied immunohistochemically by the avidine-biotin-peroxidase method, using an anti-PTHrP monoclonal antibody (MAb), 4B3. In normal and reactive conditions, PTHrP was positive in parabasal cells, squamous metaplasia, and hyperplastic reserve cells. In neoplastic conditions, 96% (43/45) of invasive squamous-cell carcinomas were positive for PTHrP, regardless of the patients' serum calcium levels. Two cases with hypercalcemia were strongly positive for PTHrP and showed prominent stromal interaction of the scirrhous type. In CIN, including koilocytic atypia, 76% (32/42) of cases were positive for PTHrP. In contrast, 91% (10/11) of adenocarcinomas were negative for PTHrP. In conclusion, we found, first, that in non-neoplastic conditions, the presence of PTHrP was correlated with the transformation of progenitor cells into squamous epithelia and with the maturation of keratinocytes and, second, that in squamous-cell carcinoma, the degree of keratinization and stromal interaction was higher in direct proportion to the apparent incidence of detectable PTHrP.

Animals↗

PubMed1992

A novel transthyretin mutation associated with familial amyloidotic polyneuropathy.

We characterized the mutation associated with familial amyloidotic polyneuropathy in a Japanese patient. Sequence analysis of polymerase chain reaction-amplified exons of the transthyretin gene revealed a novel point mutation resulting in a substitution of arginine for glycine at position 47. The mutation was confirmed using allele-specific olgonucleotide hybridization procedures. This most likely represents a de novo mutation since neither parent carries the mutant allele.

Adult↗

PubMed1992

The expression of parathyroid hormone-related protein (PTHrP) in normal parathyroid: histochemistry and in situ hybridization.

The expression and localization of parathyroid hormone-related protein (PTHrP), a major factor responsible for humoral hypercalcemia of malignancy (HHM), was investigated in 14 cases of surgically resected normal parathyroid glands. For light microscopic immunohistochemistry, formalin-fixed and paraffin-embedded specimens were stained with avidin-biotin-peroxidase complex (ABC) using the anti-PTHrP monoclonal antibody (MoAb), 4B3. Four percent paraformaldehyde (PFA)-fixed and OCT compound-embedded specimens were used for pre-embedded immunoelectron microscopy. For in situ hybridization, 4% PFA-fixed, frozen sections were studied using a bromodeoxyuridine (BrdU)-labeled PTHrP cDNA probe. Immunohistochemically, 12 of the 14 cases were positive for PTHrP, which was observed mainly in the oxyphil and transitional oxyphil cells. The chief and clear cells, on the other hand, were faintly positive. Electron microscopically, secretory granules positive for PTHrP were observed in cells containing abundant mitochondria. Consistent with the PTHrP immunoreactivity, transcripts of PTHrP were observed also in the oxyphilic cells by in situ hybridization. Thus the production and secretion of PTHrP was shown by the oxyphil cell lineage in the normal parathyroid glands.

Histocytochemistry↗

PubMed1992

A case of localized peritonitis caused by obstructive colitis proximal to rectal carcinoma: a rare manifestation of obstructive colitis.

A case of obstructive colitis associated with rectal carcinoma in a 56 year old Japanese man is reported herein. He presented to Shinkokura Hospital with severe abdominal pain following a one month history of anal bleeding and mild abdominal pain. On palpation, muscle guarding was observed in the left lower quadrant and the white blood cell count was 14,200/mm3. An exploratory laparotomy was performed under the provisional diagnosis of acute abdomen, which revealed localized peritonitis 8 cm oral to an area of rectal carcinoma. An anterior resection of the lesion was therefore performed together with a descendo-proctostomy. The histopathologic diagnosis revealed adenocarcinoma and obstructive colitis involving the entire thickness of the sigmoid colon and resultant fibrino-purulent peritonitis. His post-operative course was uneventful and he was continuing to do well on the 30th postoperative day, at the time of writing. The clinical significance of this combination of obstructive colitis with rectal carcinoma is briefly discussed following the presentation of this case.

Adenocarcinoma↗

PubMed1992

Intra-arterial administration of methotrexate, adriamycin, and cisplatin as neoadjuvant chemotherapy for bladder cancer.

As neoadjuvant chemotherapy for advanced bladder cancer, the intra-arterial administration of methotrexate (MTX), Adriamycin (ADM), and cisplatin (CDDP; IA-MAC) was evaluated. A total of 48 patients with bladder cancer (greater than or equal to T2 or CIS) were selected and received 30.1 mg MTX, 34.5 mg ADM, and 89.1 mg CDDP as an average course. The mean tumor-regression rate after 2 or 3 weeks was 52.3%, and patients with grade 3 transitional-cell carcinoma showed the best results, achieving a 69.6% regression rate. In 30 cases (63%), downstaging was observed. Among the 46 patients who underwent subsequent surgical therapy, the bladder could be preserved in 26 cases by transurethral resection or segmental resection. According to the criteria of the Japanese Association of Cancer Therapy, a histological effect of GIII or better was obtained in 15 cases (29%). The histological effect correlated well with the tumor-regression rate. As compared with intravenous therapy with MTX, vinblastine, ADM, and CDDP (M-VAC), IA-MAC treatment was well tolerated due to its lower degree of bone marrow suppression, and it resulted in a longer disease-free interval and better survival. In addition, the period prior to surgical therapy was shortened in this study. These results suggest that IA-MAC chemotherapy can be useful as an arm of multidisciplinary treatment of advanced bladder tumors.

Aged↗

PubMed1992

A ring electrode to record extraocular muscle activities during skull base surgery.

A ring-shaped electrode was developed and used in 20 patients to record evoked electromyographic responses directly from the extraocular muscles during skull base surgery. Intra-operative monitoring with this electrode helps the surgeon to localize the nerves that innervate the extraocular muscles precisely and to refrain from disturbing important neural structures during operations. Such monitoring also provides some insight into the pathophysiology of the dysfunction of these nerves resulting from skull base lesions.

Abducens Nerve↗

PubMed1992

Proliferating cell nuclear antigen in breast lesions: correlation of c-erbB-2 oncoprotein and EGF receptor and its clinicopathological significance in breast cancer.

Monoclonal anti-proliferating cell nuclear antigen (PCNA PC10), which is directed against a 36 kDa auxiliary protein for DNA polymerase delta specific for the S-phase of cell cycle, was used to measure tumour cell proliferation in 4 lactating breasts and 98 benign and malignant breast tumours. The percentage of PCNA-positive cells determined by point counting was significantly lower in the lactating breast [mean 3.6%, standard deviation (SD) 0.67, n = 5] than in fibroadenoma and mastopathy (mean 23.7, SD 5.0, n = 2). Primary breast carcinoma showed a PCNA index ranging from 2% to 36% (mean 12.3, SD 9.3, n = 50), whereas in recurrent carcinoma the index was mean 28.5, SD 4.0. A high index was correlated with c-erbB-2 and epidermal growth factor (EGF) receptor membrane reactivity, worsening histological grade, poor survival and disease-free survival. The expression of c-erbB-2 and EGF receptor was associated with poor survival and disease-free survival in primary breast cancer patients.

Breast Neoplasms↗

PubMed1992

Immunohistochemical study of epidermal growth factor and transforming growth factor-beta in the penetrating type of early gastric cancer.

We report that the penetrating type of early gastric cancer (PEN) is a specific type of early gastric cancer and that the poorly differentiated PEN type could be considered an initial lesion of linitis plastica-type cancer. We performed an immunohistochemical study to clarify the role of growth factors (epidermal growth factor [EGF] and transforming growth factor-beta [TGF-beta]) in the PEN type of early gastric cancer. The results indicated that the PEN type of early gastric cancer has a high growth capacity. Moreover, it was suggested that EGF was involved in its specific infiltrative growth and that both EGF and TGF-beta were involved in its specific scirrhous growth. From these findings, it was assumed that the immunohistochemical staining of EGF and TGF-beta in endoscopic biopsy specimens was useful for the diagnosis of the PEN type of gastric cancer and also for the diagnosis of the initial lesion of linitis plastica-type gastric cancer.

Epidermal Growth Factor↗

PubMed1992

Acute cytogenetic effect of benzene on rat bone marrow cells in vivo and the effect of inducers or inhibitors of drug-metabolizing enzymes.

Acute cytogenetic effects of benzene in LE rat bone marrow cells in vivo were studied. Chromosome aberrations (CA) induced by benzene consisted mainly of gaps and breaks. Cells with exchanges were rarely observed. The incidence of benzene-induced CA was at its maximum level 12 h after the p.o. or i.p. administration of benzene, dependent on the dose of benzene administered, and higher in male rats than in female rats. However, the sex difference was not observed in the repeated inhalation experiment. Chromosome damage was higher with the p.o. than the i.p. administration. LE rats were more sensitive than Wistar and SD rats to the clastogenic action of benzene. Phenobarbital and Sudan III are well known as inducers of drug-metabolizing enzymes. The peak percentage of benzene-induced CA in the rats pretreated with phenobarbital was observed 6 h after the benzene injection, and it occurred at a higher level than in the rats given only benzene. On the other hand, Sudan III pretreatment suppressed benzene-induced CA at all periods after the benzene injection. SKF-525A (a cytochrome P-450 inhibitor) and cyclohexene oxide (an epoxide hydrase inhibitor) pretreatment also suppressed benzene-induced CA.

Animals↗

PubMed1992

Endoscopic mucosectomy for early gastric cancer using modified strip biopsy.

We present a modification of strip biopsy (SB), one of the endoscopic treatment modalities for early gastric cancer. Using a side-viewing endoscope and a special electrocautery snare, we treated 6 patients with early carcinoma of the intestinal type with this modified strip biopsy (MSB). All tumors could be completely resected and 5 patients were not operated on: All 5 remained tumor-free at follow-up of at least one year. These results compared favorably with a historical control group of 17 patients with early gastric cancer treated with conventional strip biopsy. We therefore recommend applying our new method of MSB especially in the intestinal type of early gastric carcinoma; these preliminary data however, need confirmation in larger trials.

Adenocarcinoma↗

PubMed1992

Expression and characterization of kinase-active v-erbB protein using a baculovirus vector system.

The v-erbB gene is an oncogene of the avian erythroblastosis virus encoding a protein that is a truncated version of the epidermal growth factor receptor. The v-erbB protein was expressed alone or as polyhedrin-erbB fusion proteins using the Bombyx mori nuclear polyhedrosis virus vector. The expression level of the fusion protein whose polyhedrin portion consisted of only 8 amino-terminal amino acids was more than ten times higher than that of the non-fusion protein. Studies with tunicamycin showed that the recombinant v-erbB proteins were glycosylated. The recombinant protein autophosphorylated tyrosine residues, and phosphorylated a synthetic tyrosine-containing peptide and lipocortin I. These observations indicate that functional v-erbB protein can be expressed in silkworm-derived cells, and furthermore, that this system can be used for large-scale production.

Amino Acid Sequence↗

PubMed1992

Establishment of a novel granulocytic sarcoma cell line which can adhere to dermal fibroblasts from a patient with granulocytic sarcoma in dermal tissues and myelofibrosis.

A novel human myeloid cell line, designated HSM-1, has been established from the pleural effusion of a patient with granulocytic sarcoma (GS) who had been followed as having primary myelofibrosis for 10 years. When he was diagnosed as having granulocytic sarcoma in dermal tissues, no evidence of malignant transformation into leukaemia was found in both the peripheral blood and bone marrow. The established cell line was positive for myeloperoxidase, Sudan black B, Naphthol AS-D chloroacetate esterase. Surface marker analysis revealed that HSM-1 expressed CD4, CD13, CD11a, CD11b, Leu8, CD49b, CD49d, CD49e, CD29 and HLA-DR. To clarify why the unusual myeloid tumours developed in non-haematopoietic tissues, we examined the capability of HSM-1 to bind to skin fibroblast layers. The HSM-1 cells were found to bind to both bone marrow stromal layers and skin fibroblast layers. Among the other myeloid cell lines tested, none was found to bind to skin fibroblast layers. These findings suggest that the GS cell line may be derived from a haematopoietic precursor cell which can bind to skin fibroblasts and is localized in non-haematopoietic tissues resulting in the formation of extramedullary myeloid metaplasia. HSM-1 is a useful tool for analysing the characteristics of granulocytic sarcoma and homing receptors for haematopoietic stem cells.

Antigens, Surface↗

PubMed1992

Molecular rearrangement of lactose plasmid DNA associated with high-frequency transfer and cell aggregation in Lactococcus lactis 712.

High-frequency conjugation of the lactose plasmid pLP712 is associated with a constitutive cell aggregation phenotype and is facilitated by cointegration with a sex factor. Analysis of 23 independently derived enlarged lactose plasmids revealed that the sex factor DNA present in cointegrates varied in size. This suggested that more than simple cointegration with a sex factor plasmid was involved. Further analysis led to the discovery of a chromosomally located sex factor that could excise and be lost or exist as labile plasmid DNA. Cointegration with this sex factor was shown to be promoted by transposition of a copy of ISSI present on the lactose plasmid, and models are presented to account for the complex and variable structures of the resulting enlarged lactose plasmids.

Base Sequence↗

PubMed1992

[Detection of Neisseria gonorrhoeae in first-voided urine sediments from male urethritis patients by polymerase chain reaction].

Neisseria gonorrhoeae was detected from first-voided urine sediments of male patients with urethritis by polymerase chain reaction (PCR). Urine and urinary sediment were treated with proteinase K, and DNA was further purified by phenol extraction. Two oligonucleotides based on sequences within a ribosomal RNA gene from N. gonorrhoeae were used as primers for the PCR. A DNA fragment of 206 bp specific for N. gonorrhoeae was amplified by PCR and detected by agarose gel electrophoresis. In 19 specimens of urine sediments collected from 21 patients in whom N. gonorrhoeae was isolated from urethral swab by culture, 206 bp DNA fragment was amplified by PCR. In all specimens of urine sediments from 24 patients in whom cultures for N. gonorrhoeae were negative, no DNA was amplified by the PCR. The overall coincidence rate between the PCR for detecting N. gonorrhoeae in first-voided urine sediments and culture in urethral swab was 95.6% (43/45). PCR procedure for detection of pathogens from first-voided urine sediments would be noninvasive and would be applied for the diagnosis of gonococcal urethritis and chlamydial urethritis.

Chlamydia trachomatis↗

PubMed1992

[Comparison of polymerase chain reaction and enzyme immunoassay (Chlamydiazyme) in detection of Chlamydia trachomatis from male urethritis].

A method using polymerase chain reaction (PCR) was compared to an enzyme immunoassay (Chlamydiazyme) for detection of Chlamydia trachomatis by testing a reference strain and clinical specimens. Two oligonucleotides based on sequences within the major outer membrane protein gene from C. trachomatis serovar L2 were used as primers for the PCR. A DNA fragment of 242 bp specific for C. trachomatis was amplified by the PCR, when DNA of greater than or equal to 10(2) C. trachomatis was used as template for the PCR. A chlamydial antigen was detected by Chlamydiazyme, when greater than or equal to 2.6 x 10(3) C. trachomatis were applied for the enzyme immunoassay. The PCR method was 26 times more sensitive than Chlamydiazyme in detection of C. trachomatis. The PCR method and Chlamydiazyme were carried out to examine 74 urethral swabs obtained from male patients with urethritis for detection of C. trachomatis. In 45 of 74 specimens, the DNA fragment of C. trachomatis was amplified by the PCR, and in 41 of 74, the chlamydial antigen was detected by Chlamydiazyme. The detection rate of the PCR method (60.8%) was higher than that of Chlamydiazyme (55.4%). The positive coincidence rate of the PCR method to Chlamydiazyme was 100% (41/41) and negative coincidence rate was 87.9% (29/33). The overall coincidence rate between the two methods was high (94.6%). Thus, the PCR method was more sensitive than Chlamydiazyme for detection of C. trachomatis and specific for diagnosis of chlamydial urethritis.

Chlamydia trachomatis↗

PubMed1992

[Detection of Neisseria gonorrhoeae from male patients with urethritis by polymerase chain reaction].

A polymerase chain reaction (PCR) procedure was developed for detection of Neisseria gonorrhoeae. Two oligonucleotides based on sequences within a 16S ribosomal RNA gene from N. gonorrhoeae were used as extension primers for the PCR. A single DNA fragment of 206 bp was amplified, when N. gonorrhoeae DNA was template for the PCR. No amplified product was detected in Chlamydia trachomatis DNA, Ureaplasma urealyticum DNA or other bacterial DNAs. The DNA fragment of 206 bp was detected on agarose gel electrophoresis, when DNA of greater than or equal to 6.5 N. gonorrhoeae per PCR was used as template DNA for the PCR. The culture and the PCR were carried out for detection of N. gonorrhoeae in 67 urethral swabs obtained from male patients with urethritis. In 27 of 28 specimens in which N. gonorrhoeae was isolated and identified by the culture, 206 bp DNA fragment was amplified by the PCR, but in one specimen no DNA fragment was detected. In 2 of 39 culture-negative specimens, 206 pb DNA fragment was detected and in the remaining specimens, PCR was negative for N. gonorrhoeae. The overall detection coincidence rate between the culture and the PCR was 95.5% (64/67). Thus, the PCR procedure developed in this study was sensitive and specific for detection of N. gonorrhoeae and could be applied for diagnosis of gonococcal urethritis.

Gonorrhea↗