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Biomedical subjects

M Koga

Publications and source records attributed to M Koga.

At least 595 records · Page 33Linked to original sources
PubMedDate not supplied

Comparative study on evaluation methods for serum testosterone level for PADAM diagnosis.

The International Society for the Study of the Aging Male (ISSAM) recommends that a diagnosis be based on a patient's total testosterone (TT), calculated free testosterone (cFT), or calculated bioavailable testosterone (cBT) for partial androgen deficiency of the aging male (PADAM). The purpose of this study was to confirm whether hypogonadism of patients with PADAM is related to symptoms and clarify which criteria of testosterone recommended by ISSAM is suitable for Japanese patients. A total of 90 patients with PADAM symptoms were included in this study. Endocrinologic profiles were reviewed as appropriate, and PADAM symptoms were judged by means of several questionnaires. Laboratory values and symptoms were compared between patients with and without hypogonadism. Even when any criterion of testosterone was used for diagnosis of hypogonadism, AMS (total and subscales), IIEF-5, or SDS scores of PADAM symptoms did not differ significantly between patients classified as having and not having hypogonadism. No other endocrinologic variables than testosterone differed significantly between them, either. PADAM symptoms are not related to testosterone level and it is still obscure whether ISSAM's criterion can be adopted for Japanese patients with PADAM. Other pathology needs to be addressed for evaluation and diagnosis of PADAM in Japan.

Aging↗
PubMedDate not supplied

Association of selenoprotein P with testosterone production in cultured Leydig cells.

Selenoprotein P, a plasma selenoprotein, is thought to act as an antioxidant in the testis, similar to glutathione peroxidase. mRNA encoding selenoprotein P was selectively expressed by Leydig cells, suggesting participation in testosterone production. On the other hand, testosterone production has been linked to O2 toxicity in cultured Leydig cells. The authors, therefore, examined changes in selenoprotein P mRNA expression and testosterone production following stimulation by a stable analog cyclic adenosine 3',5'-monophosphate (cAMP) in cultured Leydig cells (MLTC-1 cells) under normal O2 concentrations. Selenoprotein P mRNA was analyzed by Northern blotting, while testosterone concentration in culture medium was measured by radioimmunoassay. When cAMP was added to cultures at 0, 0.01, 0.1, or 1 mM, selenoprotein P mRNA expression showed dose-dependent stimulation. cAMP was added at 0.1 mM to cultures, and the selenoprotein P mRNA expression and testosterone concentration were evaluated after incubation times of 2, 5, 9, 15, or 24 h. Selenoprotein P mRNA expression was maximal at 9 h. Testosterone concentration in the medium also increased, becoming maximal at 15 h. Selenoprotein P induced in Leydig cells following cAMP stimulation may counteract O2 toxicity from cAMP-mediated increases in testosterone production.

Animals↗
PubMedDate not supplied

Outcome of surgical treatment for obstructive azoospermia.

The efficacy of reanastomosis was evaluated in 30 patients with obstructive azoospermia, including 19 postvasectomy cases; 7 cases complicating inguinal herniorrhaphy; 2 cases with a characterized isolated congenital anomaly; 1 case of Young's syndrome; and 1 case with an unknown, possibly congenital cause. In the postvasectomy group. successful vasovasostomy was achieved in 15 of 18 cases (83.3%; 1 postvasectomy patient dropped out of the study prior to analysis). Duration of obstruction in the 3 cases where anastomosis failed was 6, 9, and 20 years. In the group where obstruction followed inguinal herniorrhaphy, unilateral vasovasostomy was performed in 6 cases, and transepididymovasostomy was performed in 1 case. Success was achieved in 3 of 6 cases (50%; 1 case was not included because failure of spermatogenesis was detected postoperatively). In all 4 remaining cases, microsurgical epididymovasostomy or transepididymovasostomy was performed, but success was achieved only in the case of Young's syndrome. Although mailed questionnaires and telephone interviews indicated occurrence of natural pregnancy in only 4 affected couples, postoperative sperm counts were relatively satisfactory as in previous reports.

Adult↗
PubMedDate not supplied

Effect of lifestyle factors on infertility in men.

Environmental factors, changes in lifestyle and occupational exposures are responsible for declining human semen quality. We investigated the effects of history of surgery and lifestyle choices on infertility of 271 infertile men and 251 healthy volunteers. The frequency of varicocelectomy was significantly higher in infertile men (2.9%) than in controls (0.4%; P < 0.05). Alcohol use was significantly more common in infertile men (92%) than in controls (80%; P < 0.01). Satisfaction with sexual life was greater in controls (85%) than in infertile men (77%; P < 0.05). Other factors had no effect.

Adult↗
PubMedDate not supplied

Bromocriptine for infertile males with mild hyperprolactinemia: hormonal and spermatogenic effects.

To clarify the influence of hyperprolactinemia on spermatogenesis and steroidogenesis in infertile male patients, the serum prolactin (PRL), luteinizing hormone (LH), follicle-stimulating hormone (FSH), testosterone, and estradiol concentrations were and the effect of bromocriptine treatment on spermatogenesis was examined. A total of 1234 patients were evaluated and 147 men had hyperprolactinemia. Of these, only 30 had PRL concentrations more than twice the upper limit of normal and most of them had a little excess over the upper limit. For 10 of these 30, serum hormone concentrations were measured and semen was analyzed before and after bromocriptine administration. No relationship between the PRL and other hormone concentrations was found. No changes were noted in the LH, FSH, testosterone, or estradiol concentrations, or in the sperm density and motility after treatment. The mean PRL decreased from 26.5 +/- 4.5 to 1.4 +/- 1.8 ng/mL. In infertile men who are mildly hyperprolactinemic, bromocriptine administration does not improve semen analysis, although it does normalize the PRL.

Bromocriptine↗
PubMedDate not supplied

Treatment with human chorionic gonadotropin for PADAM: a preliminary report.

The purpose of this study was to evaluate the efficacy and safety of human chorionic gonadotropin (hCG) for patients with partial androgen deficiency of the aging male (PADAM). Twenty-one patients over 50 years of age with PADAM symptoms were included in this study. Laboratory and endocrinologic profiles were reviewed as appropriate, and PADAM symptoms were judged by means of several questionnaires such as the Aging Males' Symptoms (AMS) scale, short version of the International Index of Erectile Function (IIEF-5), and the Self-rating Depression Scale (SDS). Laboratory and endocrinologic values and symptom scores were evaluated and compared before and after treatment by hCG injection. The treatment period was 8.0 +/- 5.0 months (3.0-24.0 months). Serum concentrations of testosterone, including total testosterone, calculated free testosterone, and calculated bioavailable testosterone, increased significantly. AMS total scores and subscores decreased significantly after treatment. However, IIEF-5 and SDS scores did not improve. With respect to adverse effects, laboratory tests showed that only red blood cell count, hematocrit and hemoglobin level increased significantly after treatment, however, these values remained within the normal range. No adverse effect was identified after treatment. We conclude that hCG injection may be considered as a treatment for PADAM.

Aged↗
PubMedDate not supplied

MRI of mucosal malignant melanoma of the head and neck.

PURPOSE: The objective of this study was to determine the characteristic MR findings for mucosal malignant melanomas of the head and neck. METHOD: We retrospectively analyzed the MR images for six patients with this entity. T1-weighted SE images with and without gadolinium and T2-weighted fast SE images were obtained. MR images were analyzed qualitatively and quantitatively by comparing the signal intensity of the melanoma with that of muscle. RESULTS: On T1-weighted images, five melanomas were hyperintense and one was isointense. On T2-weighted images, five were of mixed intensity and one showed isointensity. The mean signal intensity ratio of the primary melanoma to muscle was 1.51 and 1.39 on T1-weighted images with and without gadolinium, respectively. These values were not statistically significant. CONCLUSION: Hyperintensity on T1-weighted images is characteristic of this entity, but not universal.

Adipose Tissue↗
PubMedDate not supplied

Nonfunctioning adrenal rest tumor of the liver: radiologic appearance.

We describe the radiologic features of an adrenal rest tumor of the liver. The adrenal rest tumor appeared on ultrasound as a round, well defined, heterogeneous, solid mass in the posterior aspect of the liver, on angiography as a homogeneous hypervascular mass, and on dynamic CT as a mass containing components of both fat density and soft tissue density and showing early fill-in and early fill-out. Adrenal rest tumors should be included in the lists of hypervascular or fat-containing masses in the liver.

Adrenal Glands↗
PubMedDate not supplied

Pseudo-intracellular collagen tangles in human spinal ganglia.

A new structure was found in the spinal ganglia of 6 out of 215 human autopsy cases with various disorders. It was composed of ballooned cells fully packed with fibrillar structures showing the same staining properties as collagen. Ultrastructurally the fibrillar structures were bundles of collagen fibres with a striation of about 70nm periodicity, and they were enclosed by the cell membrane invaginated in a very complex manner into the cytoplasm. This structure, which we named 'pseudo-intracellular collagen tangle', was considered to result from a disturbance in the releasing process of collagen fibre from fibroblasts. The aetiology of the structure is unknown, but it might represent one of regressive or senile changes in human spinal ganglia.

Aged↗
PubMedDate not supplied

Sequence of murine coronavirus JHM induced neuropathological changes in rats.

Infection of 21-25-day-old rats with the murine coronavirus JHM was followed either by an acute encephalomyelitis (AE) or subacute demyelinating encephalomyelitis (SDE). The major neuropathological finding in AE, which developed within 6-12 days p.i. consisted of necrotizing lesions distributed mainly in the grey matter of the central nervous system (CNS). SDE developed 14-30 days p.i. and affected rats revealed lesions of primary demyelination with predilection sites in the white matter. The time-course for the development of lesions, virus replication and neutralizing antiviral antibody production within the first 3 weeks p.i. were studied. Within the first 2 weeks p.i., most rats showed no clinical signs but nevertheless revealed lesions typical of AE. In parallel to these neuropathological changes infectious virus could be isolated from brain and spinal cord. However, coinciding with multiplication of neutralizing JHM antibodies 10-12 days after infection no infectious virus was recoverable from CNS material. At this time many of the clinically healthy rats showed demyelinating lesions which were located at the typical predilection sites of SDE. These observations indicated that SDE was preceded by clinically silent AE lesions.

Acute Disease↗
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Short and long-term effects of interferon on serum markers of hepatitis C virus replication.

Hepatitis C virus RNA (HCV-RNA) and serological markers of HCV infection were measured in 30 patients with chronic hepatitis C who had been treated with interferon (IFN). Patients were classified into four groups according to serum alanine aminotransferase (ALT) levels after treatment. These were: as complete responders (CR); partial responders (PR); transient responders (TR); and non-responders (NR). In all 11 patients in the CR group, HCV-RNA disappeared from serum for at least 24 months and anti-c100-3 decreased progressively during this time. In the PR group, four of five patients were positive for HCV-RNA in spite of the improvement of ALT levels and decline of anti-c100-3. In the TR and NR groups, HCV-RNA disappeared transiently or remained persistently positive. The results indicate that IFN-mediated improvement of ALT and decrease of anti-HCV (anti-c100-3) were not always related to the disappearance of HCV-RNA from serum. On the other hand, sustained disappearance of HCV-RNA from serum was demonstrated in the patients who did not have post-treatment ALT relapse. This indicates that IFN can eradicate HCV from serum in some patients and provide a clinical remission of chronic hepatitis C.

Alanine Transaminase↗
PubMedDate not supplied

Local spread of HDV infection transiently occurring in Japan.

Hepatitis B virus (HBV) carriers and patients with acute hepatitis B living in the Kamigoto islands, a part of Japan with a high incidence of HBV carriage, were retrospectively tested for serum anti-hepatitis D virus (anti-HDV) and they were compared with the inhabitants of Oita City (an area with an average HBV carriage rate). The prevalence of anti-HDV in HBV-infected individuals was 8.3% (42/507) in Kamigoto and 0% (0/101) in Oita City. With one exception, all of the positive serum samples in Kamigoto were collected before 1986, and the mean age of the positive individuals was significantly younger than that of the negative individuals (P < 0.005). Among the 42 anti-HDV-positive patients, nine (21%) had definite liver disease. The route of infection was uncertain in most cases (i.e. sporadic), but two pairs of mothers and children were detected. Although the prevalence of anti-HDV positivity in Japan has been reported to be very low (about 1% or less), the present investigation showed that the local spread of HDV infection in Kamigoto occurred on a minor scale up to 1986. The infections presumably resulted from the closed environment and the high incidence of HBV carriage in these islands. Accordingly, there could be a considerable risk of the outbreak of HDV infection in the future under similar conditions, even in countries where the disease has never been detected previously.

Adolescent↗
PubMedDate not supplied

Leukemia cutis in three children: clinical and immunohistochemical studies.

We report 3 children with leukemia cutis observed at the initial diagnosis of systemic leukemia. Leukemia subtypes in the three children were congenital monocytic, acute undifferentiated, and acute monocytic, respectively. The patients were girls age 10 days, 14 years, and 11 months, respectively, at diagnosis. We describe the clinical features of the cases and the results of immunohistochemical studies on paraffin-embedded skin biopsy specimens. The skin lesions were tumors and areas of reddish purple erythema in the first child, pigmented erythema in the second, and bright red erythema in the first child, pigmented erythema in the second, and bright red erythema in the third. In the first two patients skin lesion biopsy specimens had dense leukemic infiltrates in the dermis with reactive T lymphocytes scattered among them. In the third patient, the infiltrating cells were almost all reactive T lymphocytes, with a few leukemic cells. A relationship between the leukemic-reactive cell ratio and the prognosis was suggested; dense leukemic cell infiltrates may be associated with a poor prognosis.

Adolescent↗
PubMedDate not supplied

Clinical experience with temporary vena cava filters.

An experience with temporary filter placement, which seems to be safe and effective for temporarily preventing pulmonary embolism, is reported. Since October 1997, six patients had temporary filters. There were two men and four women, with a mean age of 37 years. Three filters were placed at the infrarenal inferior vena cava, two at the suprarenal inferior vena cava, and one at the superior vena cava. All filters were placed before various surgical interventions. During filter placement, anticoagulation therapy was routinely performed. There were no complications at and during filter placement. No pulmonary emboli occurred during surgical intervention. All filters were successfully removed, two of which were exchanged for permanent filters. All patients are alive and well without recurrent deep vein thrombosis and/or pulmonary emboli during a follow-up period of 11 to 25 months. Although this experience is small, temporary filter placement is safe and effective for short-term prevention of pulmonary emboli even in older patients or those with malignant disease. Veins of the upper part of the body may be more favorable than the femoral vein for insertion of a temporary filter. Temporary filters can be safely placed not only at the infrarenal inferior vena cava, but also at the suprarenal inferior vena cava or superior vena cava.

Adolescent↗
PubMedDate not supplied

[Predictive factor for TESE (testicular sperm extraction)--ICSI (intracytoplasmic sperm injection) for non-obstructive azoospermia].

BACKGROUND: TESE-ICSI has been used very successfully in the treatment of the patients with non-obstructive azoospermia but its indication is still controversial. We performed retrospective study concerning parameters to predict successful recovery of testicular sperm from the patients and outcomes of ICSI. PATIENTS AND METHODS: 44 patients with non-obstructive azoospermia who underwent TESE-ICSI from July, 1997 to September 1999 were studied retrospectively. RESULTS: 1) Testicular sperm were retrieved from 32 patients (72.7%). ICSI was performed in 29 patients and the partner of 15 patients (46.9%) got pregnant. From 10 patients with histology of Sertoli-cell-only, we could retrieve sperm in 3 patients (30%). 2) Testicular volume, Johnsen's score count (JSC), and FSH were significant parameter to predict the recovery of testicular sperm from the patients, but if we see only the patients with JSC less than 7, there were no significant parameter. Chromosomal abnormality was not a significant parameter. 3) The partner's age, motility of recovered sperm and testicular volume correlated with fertilization rate. Chromosomal abnormality was not significant parameter to predict fertilization. CONCLUSIONS: There was no absolute parameter to predict the recovery of testicular sperm from the patients with non-obstructive azoospermia. All patients with non-obstructive azoospermia can be the indication of TESE-ICSI.

Adult↗
PubMedDate not supplied

[Clinicopathological study of the testicular microlithiasis].

PURPOSE: Testicular microlithiasis (TM) is a relatively rare condition characterized by calcific concref1p4 within the seminiferous tubules. Little has been reported on the incidence or the clinical implication of TM among Japanese. To address the problem, we evaluated pathologic specimens from biopsies and orchiectomies, of testes with various conditions. MATERIALS AND METHODS: Pathologic specimens of the testes of 200 cases, 56 from orchiectomy and 144 from testicular biopsy, were investigated. RESULTS: The pathological diagnosis of TM was confirmed in seven (3.5%) cases, four of which were associated with germ cell tumors and the other three were obtained from testicular biopsies performed for examination of infertile men. Of the 41 patients with germ cell tumors, four (9.8%) were found to have TM, and another three (2.5%) were identified among 122 patients with infertility. The prevalence of TM is significantly higher in specimen with germ cell tumors than those without germ cell tumors (p < 0.05). CONCLUSIONS: Although TM is rarely encountered, this condition is relatively often accompanied by testicular malignancy. Further investigation would be fundamental to ascertain the relationship between TM and testicular malignancy.

Adult↗
PubMedDate not supplied

HLA-DR antigen and HLA-DRB1 genotyping with nonobstructive azoospermia in Japan.

We previously reported that the HLA-A33, -B13, and -B44 antigens, which are major histocompatibility complex class I molecules, are involved in the susceptibility of nonobstructive azoospermia in Japanese men. In this report, HLA-DR antigens, which are class II molecules, are investigated by advanced DNA typing in addition to classical serological typing to study a more complex genotype of HLA-DRB2. Genotyping was performed by the polymerase chain reaction-sequence-specific primer (PCR-SSP) method of analysis and/or by a commercial rapid assay based on the polymerase chain reaction (PCR), followed by reverse dot-blot hybridization of PCR products (the Inno-LiPA assay). The allele frequencies of the HLA-DR13 antigen and the -DRB1*1302 allele were significantly higher in Japanese subjects with nonobstructive azoospermia compared with a control group of healthy Japanese men, and these alleles were associated with relative risks for nonobstructive azoospermia of 4.2 and 4.9, respectively. If we suppose this strong linkage to both HLA class I and II antigens is due to linkage disequilibrium, it may suggest the existence of a novel gene involved in spermatogenesis in the class III region, which is located between the class I and class II regions and contains several genes other than HLA.

Chromosomes, Human, Pair 6↗