[Physiopathological studies on dental pulp. I. Changes of protein fractions of the dental pulp fluid].
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Biomedical subjects
Publications and source records attributed to H Okada.
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A retrospective study was carried out to determine the prevalence of sex-chromosome mosaicism among azoospermic men and to evaluate the feasibility of using fluorescence in situ hybridization (FISH) technique to assess mosaicism and the origin of marker chromosomes. Nine hundred eighty patients with azoospermia who were referred to a male infertility clinic at a university hospital were karyotyped by G-banding using peripheral blood lymphocyte (PBL) metaphase spreads. When sex chromosome mosaic karyotype was detected, FISH analyses using sex chromosome-specific probes were performed. Seventeen of 980 patients showed evidence of sex chromosomal mosaic karyotype or mosaicism with marker chromosomes by G-banding studies of PBLs. Ten patients showed mosaicism in the number of sex chromosomes and 7 showed mosaicism with marker chromosomes. All 17 patients agreed to undergo FISH analysis. FISH confirmed mosaicism in 88.2% of these patients (15 of 17). Low-frequency mosaicism showing a frequency of less than 10% by G-banding was proved to be nonmosaicism by FISH. Marker chromosomes detected in 7 patients were proved to be derived from the Y chromosome by FISH analyses. From these data the prevalence of sex chromosome mosaicism confirmed by FISH analysis is 1.5% (15 of 980 patients). FISH analysis should be applied when mosaicism shows a frequency of less than 10% by the G-banding technique. Also, FISH analysis is indicated when a marker chromosome is detected by G-banding.
Human membrane cofactor protein (MCP, CD46) is widely distributed and is one of the plasma membrane complement inhibitors. We isolated cDNA clones encoding genetic homologues of human MCP from a rat testis cDNA library. Northern blot analysis indicated that rat MCP is preferentially expressed in testis, similar to what is found with guinea pig MCP. We identified several different cDNAs, which were presumably generated by alternative splicing from a single-copy gene. The most prevalent isoform corresponded to the Ser/Thr/Pro-rich C type of human MCP. Mouse MCP cDNA was cloned by polymerase chain reaction based on the nucleotide sequence of rat MCP. The deduced amino acid sequence showed 77.8% identity to rat MCP. Mouse MCP was also preferentially expressed in testis. Unique expression in testis in rat and mouse as well as guinea pig suggests that MCPs in these species not only act as complement regulatory proteins but may also have more specialized functions in fertilization or reproduction. Genetic mapping by linkage analysis indicated that the mouse Mcp gene is located on distal chromosome 1, closely linked to the complement receptor 2 (Cr2) gene.
Flavobacterium sp. KI72 metabolizes 6-aminohexanoic acid cyclic dimer, a by-product of nylon manufacture, through two newly evolved enzymes, 6-aminohexanoic acid cyclic dimer hydrolase (EI) and 6-aminohexanoic acid linear oligomer hydrolase (EII). These enzymes are active towards man-made compounds, the cyclic dimer and linear oligomers of 6-aminohexanoic acid respectively, but not towards any of the natural amide bonds tested. The structural genes of EI (nylA) and EII (nylB) are encoded on pOAD2, one of three plasmids harboured in Flavobacterium sp. KI72. This plasmid contains two kinds of repeated sequence (RS-I and RS-II); one of the two RS-II sequences, RS-IIA, contains the nylB gene, while the other, RS-IIB, contains a homologous nylB' gene. From comparisons of the nucleotide sequences and gene products of the nylB and nylB' genes, we now conclude that EII enzyme is newly evolved by gene duplication followed by base substitutions on the same plasmid.
Retroviruses isolated from avian, feline, murine and simian sources have been found to be inactivated and lysed by normal human serum. There is much evidence that complement is activated directly by retroviruses in the absence of antibody. Thus, human complement is thought to function as a natural defence mechanism against horizontal infection by retroviruses. Recently, a novel retrovirus, human T-cell leukaemia virus (HTLV), has been shown to be associated with adult T-cell leukaemia/lymphoma (ATL). A large number of healthy adults in south-west Japan, the West Indies and Africa carry antibodies against HTLV and these seropositive individuals are considered to be carriers of HTLV. Thus, horizontal spread of HTLV occurs frequently among humans. We set out to determine whether HTLV reacts with human complement, and report here that, unlike other animal retroviruses, HTLV is not lysed by normal human serum--this might explain the infectivity and persistence of HTLV in humans.
Ehrlichia chaffeensis, the agent of human monocytic ehrlichiosis, is closely related to the HF strain of Ehrlichia isolated from ticks in Japan. In this study, BALB/c mice inoculated intraperitoneally with the HF strain developed severe illness and died at about day 9 post-inoculation. At necropsy, diffuse liver necrosis was evident. Ehrlichial microcolonies were observed in endothelial cells, monocytes and macrophages of the liver, bone marrow, spleen, thymus, and large and small intestine. Immunocompetent mice infected with the HF strain would provide a useful model for studying pathogenesis and immunity in acute and severe ehrlichiosis caused by E. chaffeensis and related Ehrlichia spp.
Specific identification of ehrlichiae in the tissues and determination of their distribution is difficult. In this study, an in-situ hybridization method was developed to detect ehrlichial 16S rRNA in tissue specimens from mice experimentally infected with the HF strain. This strain is closely related to Ehrlichia chaffeensis, the agent of human monocytic ehrlichiosis. HF strain-specific 16S rRNA was detected in endothelial cells and monocyte-macrophages in the liver, lungs, bone marrow, spleen, lymph nodes, and large and small intestinal tissues. The results suggest that the in-situ hybridization method with a digoxigenin-labelled RNA probe specific to ehrlichial 16S rRNA will be useful for post-mortem diagnosis and for the histopathological investigation of ehrlichial infection.
The general male population has shown a long-term decline in sperm count. Induced hormonal imbalance can produce adverse reproductive effects in men, especially decreases in sperm count. One suggested cause for a decreased sperm count is a reduction in the number of Sertoli cells. The authors assessed numbers of Sertoli cells in testicular biopsy specimens obtained from azoospermic men between 1989 and 1999. The number of Sertoli cells per tubular area or circumference did not vary by year of biopsy among the tissue samples during this 10-year period. Patient age, taken as a measure of exposure duration to hypothesized abnormal hormonal environment, did not affect the number of Sertoli cells. Since no reduction in the number of Sertoli cells was observed, other pathogenic factors may be the cause of long-term decreases in sperm count.
The tumor suppressor protein p53 participates in normal cell differentiation as well as induction of programmed cell death. The authors investigated the effect of p53 overexpression on spermatogenesis by transferring p53 gene into the rat testes. Replication-deficient recombinant adenovirus vectors were constructed to include cytomegalovirus (CMV) promoter driving wild-type p53 (Ad-CMV-p53) or beta-galactosidase (Ad-CMV-beta-gal). Virus was delivered to cells of the tubules by slow retrograde injection through the rete testis. At 0, 4, 7, and 14 days, testes were removed, weighed, and analyzed histopathologically, including immunohistochemistry for p53, Bcl-2, Bax, and interleukin-1beta converting enzyme (ICE). Testicular weight was decreased in Ad-CMV-p53 group at 14 days after injection, while no change occurred in phosphate-buffered saline-injected controls or Ad-CMV-beta-gal-infected testes. Beyond 4 days, cell degradation in tubules interfered with immunohistochemical observation in the Ad-CMV-p53 group. At 4 days, p53 was expressed mostly in spermatocytes. Bax showed greater expression in the p53 group than in the control or Ad-CMV-beta-gal group. ICE, expressed mostly in spermatids, was more abundant in the p53 group than in controls. Overall, p53 overexpression in the testis impaired spermatogenesis.
Specific assays have been developed for bioactive inhibin dimers, inhibin A and B, and inhibin alpha-subunit precursor pro alphaC. To better understand the role of serum inhibin pro alphaC in infertile men, the authors measured these forms of inhibin in sera from 39 infertile men and analyzed inhibin relationships with serum gonadotropins, testosterone, and estradiol. All subjects had oligozoospermia. Inhibin A levels were undetectable in all subjects. Inhibin B concentrations were 117 +/- 59 pg/mL. Inhibit B concentrations correlated negatively with serum FSH (r = .584, p < .0001) and positively with sperm count (p < .01) and bilateral testicular volume (r = .607, p < .0001). The concentration of pro alphaC was 556 +/- 236 pg/mL (normal range, 446 +/- 28). Inhibin pro alphaC showed no correlation with serum FSH, LH, testosterone, sperm concentration, and bilateral testicular volume. In addition, inhibin pro alphaC was not correlated with inhibin B. Pro alphaC is unlikely to be a useful marker for spermatogenesis in infertile men compared with inhibin B.
Nitric oxide (NO) plays multiple roles in the reproductive system. The authors studied the effect of NO on LH-stimulated steroidogenesis in primary cultures of rat Leydig cells, particularly seeking a link between inhibition of steroidogenesis and changes in expression of steroidogenic acute regulatory protein (StAR). Sodium nitroprusside (SNP), an NO generator, did not alter basal testosterone, but dose-dependently reduced testosterone production in the Leydig cells stimulated by LH (100 ng/mL) at 3 h after addition of SNP. Induction of StAR mRNA transcripts could be detected as early as 1 h after the addition of LH, but no effect was detected of SNP on LH induction of StAR mRNA. StAR, then, is not affected in the inhibition by NO of LH-stimulated steroidogenesis in Leydig cells.
The effect of sildenafil on health-related quality of life (HRQOL) was evaluated. Forty men (61+/-8 years old, mean +/- SD) with erectile dysfunction (ED) were studied. Sexual satisfaction as well as HRQOL according to SF-36 scales was evaluated before and after treatment with Viagra (Sildenafil citrate) at a dose of 25 or 50 mg. After treatment with Viagra, scores increased for all scales; of these, physical functioning (PF), general health (GH), and role-emotional functioning (RE) showed significant differences from baseline scores. Patients who evaluated effectiveness of the treatment as excellent showed significantly better PF, role-physical functioning (RP), and GH scale scores than those who evaluated their outcome as good or poor (p<.05 for RP and GH; p < .01 in PF). Incomparison with the scores at baseline, patients who considered outcome of Viagra to be excellent also showed significant improvements in PF, GH, and RE. Viagra treatment can improve HRQOL as well as sexual function in many patients.
To determine whether an absence of leukocytes in semen and urine predicts an absence of Chlamydia trachomatis in asymptomatic infertile men, chlamydial DNA was detected in subjects' semen and urine by ligase chain reaction (LCR). Ninety-eight infertile men were studied, including 39 cases of oligozoospermia, 19 of azoospermia, 16 of asthenozoospermia, and 24 of normozoospermia. None of the subjects had pyospermia or pyuria. C. trachomatis was detected by LCR. Antichlamydial and antisperm antibody were also measured. C. trachomatis was detected by LCR in the semen of only 1 of 98 patients (1.02%), but not in the urine samples. In C. trachomatis-positive patients LCR, IgG, and IgA levels were higher than normal. No antisperm antibody was detected. Even if leukocytes are not observed in the semen and urine of asymptomatic infertile men, the presence of C. trachomatis in semen specimens is rarely observed. Therefore, it should be noted that the presence of C. trachomatis in such cases is addressed in the context of artificial insemination and other assisted reproductive technologies.
Self-monitoring values of blood pressure may better reflect the average long-term blood pressure value than sporadic measurements in the physician's office and be more useful for blood pressure control. In the present study, we compared the results of self-monitoring of blood pressure values, especially in the morning, with office blood pressure, and related these to progression of chronic renal insufficiency and left ventricular hypertrophy (LVH). Thirty-four patients were selected from 316 subjects with chronic renal insufficiency (average serum creatinine 1.72 +/- 0.15 mg/dl, mean age 52.6 +/- 3.5 yrs) in accordance with the following criteria (1) office blood pressure was less than 140/90 mmHg, (2) blood pressure was controlled with amlodipine (5-20 mg/day) combined with benazepril (2.5 mg/day), (3) morning blood pressure was greater than 150/90 mmHg at 6-9 AM and (4) LVH had been determined by echocardiography (posterior wall thickness; PWT > or = 12 mm). The patients were assigned to 2 groups at random and were given: (1) guanabenz (GB; 2-8 mg at I I PM, n = 17) or (2) placebo (n = 17). Two years later, the average blood pressure of both groups as measured in the office was not significantly different: however, BP in the morning was significantly reduced from 158 +/- 6 to 134 +/- 4 mmHg in GB treated group (P< 0.001). In 14 of 17 patients in GB treated group, LVH resolved and there was only mild progression of nephropathy (serum creatinine: 1.69 +/- 0.18 to 1.81 +/- 0.19 mg/dl). In 12 of 14 patients in placebo group, whose morning blood pressure remained at greater than 150/90 mmHg, LVH was retained and there was moderate progression of nephropathy (serum creatinine: 1.73 +/- 0.14 to 2.62 +/- 0.50mg/dl). From these results, it is suggested that antihypertensive treatment with combination therapy based on self-monitoring BP is cardio-renoprotective in patients with chronic renal insufficiency and LVH.
Apoptosis in the testis represents an important physiological mechanism that regulates the number of germ cells in the seminiferous epithelium. This apoptosis is believed to be regulated by many factors, including growth factors and cytokines, which appear to suppress apoptosis of the germ cells. In this study, we examined the roles of Sertoli cells on the regulation of pachytene spermatocyte (PS) and round spermatid (RSd) apoptosis with either a co-culture trans-well system or a direct contact system. Apoptosis was detected by low molecular weight DNA fragmentation assay, in situ end labeling, and an LDH assay. In addition, the level of Bcl-2, Bax, and ICE mRNAs in PS and RSd by Northern blot analysis. When PS and RSd were cultured with Sertoli cells in either a trans-well system or direct contact system, the extent of apoptotic DNA fragmentation and LDH level were both significantly lower than those control values. TUNEL staining also revealed the inhibition of apoptosis of PS and RSd when they were cultured with Sertoli cells compared with controls (p <0.05). Moreover, the extent of apoptotic DNA fragmentation and LDH level were significantly lower in the direct contact system than in the trans-well system. TUNEL staining also demonstrated a more decrease in apoptosis of PS and RSd in the direct contact system compared with the trans-well system (p < 0.05). PS and RSd cultured with Sertoli cells exhibited an increase in Bcl-2 mRNA, whereas those cultured with serum-free medium did not show any change. The levels of Bax and ICE mRNAs decreased in PS and RSd cultured with Sertoli cells in comparison with control values. These results suggest that Sertoli cells can prevent apoptosis of germ cells, and that the effect of Sertoli cells on germ cells is mediated by cell to cell interaction or, remote effects of inhibitory factors on apoptosis.
The effects of hyperprolactinaemia on sperm function were investigated in 264 men with oligozoo-, asthenozoo-, or teratozoospermia and who were attending a male infertility clinic. None of the patients exhibited galactorrhea or complained of impotence. There was no correlation between abnormal values in spermiogram and hyperprolactinaemia. After multiple measurements of serum prolactin concentration, 15 cases (5.7%) were diagnosed as hyperprolactinaemic (> or = 10 ng ml-1). Six of these patients were taking cimetidine and six were taking anti-anxiety drugs. Serum prolactin returned to the normal level after discontinuation of these drugs; thus these 12 cases were considered as drug-induced hyperprolactinaemia. The other three patients were diagnosed as having pituitary microadenomas and received bromocriptine treatment; the serum prolactin levels normalized within 1 month. No changes in sperm concentration, motility or morphology were found after normalization of serum prolactin levels. Sperm fertilizing ability was monitored by the hamster test for 10 months in the three patients with pituitary microadenoma, and no improvement was observed. Results suggest that hyperprolactinaemia, which does not cause symptoms, has little effect on the impairment of sperm functions. Measurement of serum prolactin in infertile men could be justified, however, for early detection of pituitary adenomas.
The purpose of this study was to compare the morphology/morphometry and fertilizing capacity of human spermatozoa recovered via swim-up method, Percoll density gradient method, and SpermPrep II filtration method. Thirty-three ejaculates were equally divided into 2 aliquots. Aliquot 1 was processed via the direct swim-up method, whereas aliquot 2 was filtered via a SpermPrep II column. The Percoll density gradient method was compared with the SpermPrep II method in a similar protocol using 43 ejaculates. Sperm populations recovered via the SpermPrep II filtration method showed significantly higher hypoosmotic swelling test results, acrosin profiles, and percentage of hyperactivated spermatozoa than sperm fractions recovered by the swim-up method. Furthermore, significant differences were found in most of sperm morphometric parameters between the above sperm populations. However, sperm fractions recovered via the SpermPrep II method did not show significantly different values for these same tests and for most of sperm morphometric parameters compared to the Percoll density gradient method. These results suggest that the SpermPrep II filtration and Percoll density gradient method are equally efficient in isolating sperm subpopulations with better functional parameters than the swimup method.
Acrosin activity of spermatozoa from infertile patients and fertile volunteers was measured. Acrosin activity of spermatozoa from asthenozoospermic patients and patients with unexplained infertility was lower than that from fertile volunteers. We utilize the zona-free hamster egg-sperm penetration test to select candidates for conventional in vitro fertilization among unexplained infertile patients. The zona-free hamster egg sperm penetration test, however, requires several hours and special equipment which are not used in the clinical setting. It is preferable that other sperm function tests or a combination of them can replace this test. Thus three distinct tests of sperm function, namely, acrosin activity, Penetrak test, hypo-osmotic swelling test, were compared with the hamster test, using spermatozoa from patients with unexplained infertility. A combination of the Penetrak test and measurement of acrosin activity could predict the results of the zona-free hamster egg sperm penetration test with 88.2% accuracy. Thus, the hamster test should be done when either Penetrak test or measurement of acrosin activity showed abnormal values.