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Biomedical subjects

M Mochizuki

Publications and source records attributed to M Mochizuki.

At least 19 recordsLinked to original sources
PubMed1992

Polymerase chain reaction for the detection of the varicella-zoster genome in ocular samples from patients with acute retinal necrosis.

We used the polymerase chain reaction to detect the virus genome in ocular samples from patients with clinically diagnosed acute retinal necrosis. Four samples from four patients with acute retinal necrosis, and five samples from three patients with other ocular diseases (sarcoidosis, rhegmatogenous retinal detachment, and epiretinal membrane of unknown origin) were evaluated. The samples consisted of aqueous humor, vitreous, or subretinal fluid. Primers were specific for varicella-zoster virus, herpes simplex virus, or cytomegalovirus. The varicella-zoster virus genome was detected in three of the four samples from patients with acute retinal necrosis. Among these three positive samples, two had PstI-site-less point mutation, strains that have been described only in Japan and of low prevalence. Samples from patients with diagnoses other than acute retinal necrosis yielded negative results when varicella-zoster virus primer was used. No sample was positive for herpes simplex virus or cytomegalovirus primers.

Adult↗
PubMed1992

[Biology of trophoblast and its endocrinological profiles].

The trophoblast of human placenta is composed of syncytiotrophoblast (S-cell) and cytotrophoblast (C-cell). C-cell displays proliferative properties, while S-cell displays little potential for proliferation. A close similarity between cytologic localization of myc product and [3H]thymidine labeling suggests that myc expression is linked to trophoblast proliferation. In situ hybridization with cDNA probes revealed that mRNA expression of hCG alpha and hCG beta are initiated before syncytial formation, whereas hPL mRNA is expressed only in fully differentiated S-cell. EGF and EGF receptor (EGF-R) in 4-5 weeks placenta were localized to C-cell, whereas EGF and EGF-R in 6-12 weeks placenta were localized to S-cell. Consistent with these findings, EGF exerted gestational age dependent dual action on early placenta: one was to stimulate trophoblast proliferation in 4-5 weeks placenta and the other was to stimulate differentiated trophoblast function in 6-12 weeks placenta. An optimal dose of thyroid hormone stimulated progesterone, estradiol, hCG and hPL production in early placental tissues. Furthermore, women with unfavorable outcome of threatened abortion had lower T4, T3, free T4 and free T3 levels, as compared to women with favorable outcome. These data imply a role for thyroid hormone in maintaining early pregnancy. On the other hand, progesterone selectively inhibited hCG (alpha, beta) mRNAs expression and decreased hCG secretion in normal placental tissues, whereas choriocarcinoma did not respond to progesterone. This suggests that inhibitory regulation of hCG synthesis in choriocarcinoma is different from normal placenta. Characterization of choriocarcinoma hCG revealed that there are striking differences in carbohydrate structures between normal hCG and choriocarcinoma hCG. Sialic acid content in choriocarcinoma hCG was extremely lower compared to that in normal hCG. The biochemical detection of the alteration in hCG sugar chains is useful for early diagnosis of choriocarcinoma.

Cell Differentiation↗
PubMed1992

Uveitis associated with human T-cell lymphotropic virus type I.

Seroepidemiologic, clinical, and virologic studies were performed to determine whether human T-cell lymphotropic virus type I was closely associated with uveitis in two hospitals. One hospital was in an endemic area of the virus (Miyakonojo, Miyazaki) and the other hospital was in a less endemic area (Kurume). In the endemic area, the seroprevalence of the virus in patients with uveitis without defined causes (35.4%, 62 of 175 patients) was significantly higher than that in patients with nonuveitic ocular diseases (16.1%, 42 of 261 patients), or in patients with uveitis with defined causes (10.3%, eight of 78 patients). The seroprevalence in younger patients (20 to 49 years of age) with uveitis without defined causes in the area was 44.8% (30 of 67 patients), whereas it was only 9.3% (ten of 107 patients) in the other two groups. A similar observation was recorded even in the less endemic area (Kurume). Because the seroprevalence of the virus in the general population is known to be low in younger patients and to increase with age, these findings were interpreted to indicate that the association of human T-cell lymphotropic virus type I with uveitis was significant. Most patients, particularly those aged 20 through 49 years, had an intermediate uveitis characterized by a moderate inflammation in the vitreous body accompanied by an iritis and retinal vasculitis. The ocular symptoms in the patients differed from those of other types of uveitis common in Japan (Behçet's disease, Vogt-Koyanagi-Harada's disease, and toxoplasmosis, for example).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1992

Different stabilities to bile among feline calicivirus strains of respiratory and enteric origin.

Feline calicivirus (FCV) strains isolated from feces (E-FCV) were compared with FCV strains of respiratory origin (R-FCV). All strains were shown to be labile at pH 3.0. All strains except one strain of E-FCV were found to be sensitive to the action of trypsin. When exposed to bile salt (deoxycholic acid sodium salt), all R-FCV strains were markedly inactivated, but none of the E-FCV strains was inactivated. It was possible to select bile-resistant substrains from a bile-sensitive strain.

Animals↗
PubMed1992

Immunohistochemical demonstration of elevated expression of epidermal growth factor receptor in the neoplastic changes of cervical squamous epithelium.

To evaluate epidermal growth factor (EGF) receptor expression in the neoplastic process of squamous cell epithelium of the uterine cervix, normal, premalignant, and malignant cervical tissues were examined for the presence of EGF receptor by the avidin-biotin immunoperoxidase techniques with a monoclonal antibody to EGF receptor. Although normal cervical epithelium did not show appreciable staining for EGF receptor, predominant staining for the receptor was observed in most dysplastic epithelia and carcinomas in situ. In invasive squamous carcinoma, there was a great difference in the immunohistochemically detected levels of EGF receptor among the histologic cell types. Large cell nonkeratinizing carcinoma and its keratinizing counterpart contained high levels of EGF receptor; small cell nonkeratinizing carcinoma lacked immunostainable EGF receptor. These results suggest that the elevated expression of EGF receptor may be involved in the initial stage of tumorigenesis of cervical squamous epithelium and that EGF receptor expression may be related to the differentiation or dedifferentiation of cervical squamous carcinoma cells.

Antibodies, Monoclonal↗
PubMed1992

Cellular immune responses to retinal antigens in retinitis pigmentosa.

Patients with retinitis pigmentosa and a group of controls were tested for their cellular immune response toward two retinal proteins, S-antigen and interphotoreceptor retinoid-binding protein (IRBP), as well as their reaction against two synthetic peptides ("M" and "N") derived from the sequence of S-antigen and peptide "R14", derived from IRBP. Positive responses to the retinal antigens were found in larger proportions and with higher levels in the patient group than in the controls. The difference between the two groups was statistically significant in their response to S-antigen, but the patients reacted better than the controls against the other antigens as well. Of particular interest was the finding that several patients responded to both retinal proteins and/or to their peptides. These patients suffered from severe retinal changes and the data are thus interpreted as suggesting that the responses to the retinal antigens are secondary to these changes and to nonphysiological release of retinal antigens.

Adult↗
PubMed1992

Circulating myosin light chain I levels after coronary reperfusion: a comparison with myocardial necrosis evaluated from single photon emission computed tomography with pyrophosphate.

This study was performed to assess the influence of coronary reperfusion on the serial serum myosin light chain (LC)I levels and to evaluate the relationship between the peak LCI level and the infarct size calculated from single photon emission computed tomography (SPECT) with technetium-99m pyrophosphate (Tc-99m PYP) in 11 patients who underwent coronary reperfusion. Blood was drawn before reperfusion, immediately after reperfusion, and once a day for 14 days, to estimate the time course of serum LCI release. The infarct size estimated by Tc-99m PYP ranged from 7.3 to 62.4 ml. The LCI levels obtained before reperfusion were less than 2.5 ng/ml but those obtained immediately after reperfusion were much higher. The value ranged from 2.7 to 9.7 ng/ml and that expressed as a percentage of peak LCI (% peak LCI) ranged from 19 to 83%. Collateral circulation, reperfusion arrhythmia and the degree of residual stenosis had no influence upon the % peak LCI. The correlation between peak LCI levels and SPECT-determined infarct size was good, with a correlation of 0.76 (p less than 0.01, regression line by least squares method y = 3.31 + 1.53x). Early serum LCI might be influenced by coronary reperfusion but the peak LCI value reflected acute myocardial necrosis in patients who underwent coronary reperfusion.

Adult↗
PubMed1992

A novel change in cytologic localization of human chorionic gonadotropin and human placental lactogen in first-trimester placenta in the course of gestation.

Cytologic localization of human chorionic gonadotropin and human placental lactogen in developing human early placenta was analyzed by avidin-biotin immunoperoxidase techniques with an affinity-purified polyclonal antibody to beta-human chorionic gonadotropin carboxyl terminal peptide and a polyclonal antibody to human placental lactogen. In 4- to 5-week placentas human chorionic gonadotropin and human placental lactogen were found to be primarily localized to cytotrophoblasts, whereas in 6- to 12-week placentas these substances were exclusively localized to syncytiotrophoblast. We previously reported that a similar change in cytologic localization of epidermal growth factor and its receptor from cytotrophoblasts to syncytiotrophoblast in first-trimester placenta appeared between 5 and 6 weeks of gestation. Because epidermal growth factor was demonstrated to stimulate human chorionic gonadotropin and human placental lactogen production by early placental tissues, their simultaneous expression, as well as epidermal growth factor and its receptor in the cytotrophoblast of 4- to 5-week placenta and in the syncytiotrophoblast of 6- to 12-week placenta, implies that human chorionic gonadotropin and human placental lactogen production by first-trimester placenta may be regulated in an autocrine manner, wherein epidermal growth factor may serve as the signal. These findings suggest that in very early placenta, before 6 weeks of gestation, no sequential expression of human chorionic gonadotropin and human placental lactogen closely linked to syncytia formation may exist and that both can be expressed in the cytotrophoblast or undifferentiated stem cell of villous trophoblast in very early placenta.

Chorionic Gonadotropin↗
PubMed1992

HTLV-I uveitis: a distinct clinical entity caused by HTLV-I.

Seroepidemiological, clinical and virological studies were carried out in an HTLV-I endemic area to find out if HTLV-I caused an intraocular inflammatory disorder, uveitis. The seroprevalence in patients with uveitis without defined etiologies (62/175, 35.4%) was significantly higher than that in patients with non-uveitic ocular diseases (42/261, 16.1%) or in patients with uveitis with defined etiologies (8/78, 10.3%). Moreover, the seroprevalence in young adults (20-49 years) with uveitis without defined etiologies was 30/67 (44.8%), whereas it was only 10/107 (9.3%) in the other two groups. The uveitis in HTLV-I carriers was characterized clinically by a moderate inflammation of the vitreous body accompanied by a mild iritis and retinal vasculitis. The proviral DNA of HTLV-I was detected by polymerase chain reaction from the inflammatory cells in the anterior chamber in 9 out of 9 seropositive patients with the uveitis, but not in any of the tested patients with other types of uveitis. These data, thus, indicate that HTLV-I causes a specific type of intraocular inflammation, uveitis.

Adult↗
PubMed1992

Benign follicular thyroid nodule composed of signet-ring-like cells with PAS-negative thyroglobulin accumulation in dilatated rough endoplasmic reticulums.

A benign follicular thyroid nodule composed of signet-ring-like cells in a 46-year-old Japanese euthyroid woman is reported. Thyroglobulin was positive, and periodic acid-Schiff (PAS) and other mucin stainings were negative in the cytoplasm of signet-ring-like cells. Ultrastructurally their cytoplasm contained many dilatated rough endoplasmic reticulums (rERs), the largest of which compressed the nucleus toward the cellular apical portion. Functional disturbance of rER or Golgi apparatus might be the cause of this characteristic cellular change.

Adenocarcinoma, Mucinous↗
PubMed1992

Drastic alteration of cycloheximide sensitivity by substitution of one amino acid in the L41 ribosomal protein of yeasts.

Cycloheximide is one of the antibiotics that inhibit protein synthesis in most eukaryotic cells. We have found that a yeast, Candida maltosa, is resistant to the drug because it possesses a cycloheximide-resistant ribosome, and we have isolated the gene responsible for this. In this study, we sequenced this gene and found that the gene encodes a protein homologous to the L41 ribosomal protein of Saccharomyces cerevisiae, whose amino acid sequence has already been reported. Two genes for L41 protein, named L41a and L41b, independently present in the genome of S. cerevisiae, were isolated. L41-related genes were also isolated from a few other yeast species. Each of these genes has an intron at the same site of the open reading frame. Comparison of their deduced amino acid sequences and their ability to confer cycloheximide resistance to S. cerevisiae, when introduced in a high-copy-number plasmid, suggested that the 56th amino acid residue of the L41 protein determines the sensitivity of the ribosome to cycloheximide; the amino acid is glutamine in the resistant ribosome, whereas that in the sensitive ribosome is proline. This was confirmed by constructing a cycloheximide-resistant strain of S. cerevisiae having a disrupted L41a gene and an L41b gene with a substitution of the glutamine codon for the proline codon.

Amino Acid Sequence↗
PubMed1992

Hemagglutination by a human rotavirus isolate as evidence for transmission of animal rotaviruses to humans.

Human rotavirus strain Ro1845, which was isolated in 1985 from an Israeli child with diarrhea, has a hemagglutinin that is capable of agglutinating erythrocytes from guinea pigs, sheep, chickens, and humans (group O). Hemagglutination was inhibited after incubation with hyperimmune sera or in the presence of glycophorin, the erythrocyte receptor for animal rotaviruses. These results suggest that Ro1845 is an animal rotavirus that infected a human child.

Animals↗
PubMed1992

A role for thyroid hormone in the induction of ovulation and corpus luteum function.

We have previously demonstrated that thyroid hormone synergizes with follicle-stimulating hormone (FSH) to exert stimulatory effects on granulosa cell differentiation and function, suggesting that it plays a physiological role in amplifying FSH-mediated differentiation of granulosa cells. The adequate differentiation of these cells, followed by normal follicle development, is indispensable for ovulation and subsequent corpus luteum formation. Thus, in the present studies, the clinical implications of thyroid hormone in the induction of ovulation and corpus luteum function were investigated. Serum levels of total 3,5,3'-triiodothyronine (T3) and total thyroxine (T4) as well as free T3 and T4 were significantly lower in patients with weight loss amenorrhea compared to normal cycling women. Although no ovulation was induced by clomiphene therapy when the serum T3 levels were less than 80 ng/dl, the rate of ovulation induced by clomiphene increased in parallel with the augmentation of serum T3 levels. This suggests that an adequate circulating level of thyroid hormone is one of the factors responsible for successful induction of ovulation by clomiphene citrate. Furthermore, the short luteal phase and insufficient progesterone secretion observed in patients with subclinical hypothyroxinemia were not improved by clomiphene therapy alone, but were improved markedly by combined treatment with thyroid hormone replacement and clomiphene citrate. These data imply that concomitant clomiphene treatment with thyroid hormone replacement therapy is of a great value not only for ovulation induction, but also for the treatment of luteal-phase defect in patients with subclinical hypothyroxinemia.

Adolescent↗
PubMed1992

Gestational age-dependent dual action of epidermal growth factor on human placenta early in gestation.

In order to better understand the role of epidermal growth factor (EGF) in the regulation of placental growth and function, effects of EGF on proliferative activity and differentiated function of trophoblast were examined. Explants from very early (4-5 week) placentas and early (6-7 week, 8-9 week, 10-12 week) placentas were respectively cultured under a serum-free condition in the absence or presence of EGF (100 micrograms/L) for the first 48 h, and the cultures were continued for subsequent 72 h without EGF. The proliferative potential and differentiated function of trophoblast were assessed by immunohistochemical Ki-67 staining and by determining the ability to secrete human CG (hCG) and human placental lactogen (hPL), respectively. Quantitative estimates of proliferative activity based on mean percentage of Ki-67 positive nuclei showed that EGF stimulated proliferative potential of cytotrophoblast in very early (4-5 week) placental explants. The EGF stimulation of trophoblast proliferation was apparent at a 12-h EGF-treated period. By contrast, early (6-12 week) placental explants did not respond to EGF with increase in trophoblast proliferation. Instead, in early placental explant culture EGF stimulated hCG and hPL secretion with a lag period of 72 h, whereas very early placental explants did not respond to EGF with increase in hCG and hPL secretion. These results suggest that EGF exerts gestational age-dependent dual action on the first-trimester placenta: one is to stimulate trophoblast proliferation in 4-5 week placenta and the other is to stimulate differentiated trophoblast function in 6-12 week placenta.

Cell Division↗