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Biomedical subjects

M Kojima

Publications and source records attributed to M Kojima.

At least 1,117 records · Page 62Linked to original sources

The role of prostatic planimetry using transrectal sonography in prostatic diseases.

Transrectal sonography (TRS) remains the best method for prostatic planimetry, providing much information of value for the diagnosis and treatment of prostatic diseases, particularly of prostatic cancer. Currently, TRS is a routine tool in the detection and treatment of prostatic cancer. Prostatic planimetry is also available for a better understanding of elevated prostate-specific antigen (PSA). PSA indices modified by prostatic volume are applicable to the detection of prostatic cancer. The most critical application of prostatic planimetry is in monitoring prostatic cancer after treatment. Prostatic volume decreased exponentially after androgen deprivation therapy without exception in patients with prostatic cancer. The parameter "tau" (Tau), calculated from kinetic analysis based on sequential planimetric volumetry using TRS after the initiation of treatment, is a reliable prognosticator in an individual patient. Furthermore, tau predicts the manner of disease progression, and local or metastatic progression. Thus, transrectal ultrasonic prostatic planimetry is of special value in prostatic cancer.

Biomarkers, Tumor↗

Puncture of the seminal vesicles guided by a transrectal real-time linear scanner.

An interventional technique using a transrectal real-time linear scanner has been applied to the transperineal puncture of the seminal vesicles in 143 patients. The composition of this group was as follows: seminal vesiculitis, 98; hemospermia, 20; and prostatic cancer, 25. The aspiration of fluid and the injection of antibiotics and/or steroid drugs into the vesicles were performed for the diagnosis and treatment of seminal vesiculitis and hemospermia. Clinical symptoms improved in 62% of the former and in 50% of the latter cases. Cancer cells were detected in aspirated vesicular fluid in 7 out of 17 cases with prostatic cancer. A remarkable improvement in the diagnosis of prostatic cancer invasion into the seminal vesicles can be expected from this new diagnostic procedure.

Aged↗

Use of single heart cells from chick embryos for the Na+ current measurements.

To record the fast Na+ current, spheroidal heart cells enzymatically-dispersed from 3 approximately 18-day-old chick embryos were used for voltage clamping. The peak of currents in response to voltage steps of 200 ms long from holding potentials of -90 approximately -105 mV were measured. The current-voltage curves for the peak inward current showed U-shaped relations; the averaged peak current of about -1400 pA was observed at about -30 mV and the current reversed sign at +40 approximately +50 mV. Both the peak current and the reversal potential values showed marked [Na]o-dependence, i.e. reduced by 36% and by 20 mV, respectively, for a halved [Na]o. Tetrodotoxin (TTX) partially (10(-6) M) or completely (10(-5) M) suppressed the current. The steady-state inactivation of the current (h infinity) was characterized by the half inactivation voltage of around -80 mV and the slope factor of -4 approximately -8 mV. The half activation voltage and the slope factor for the steady-state activation (m infinity) were -55 mV and 4-6 mV, respectively. The electrophysiological and pharmacological properties were similar between young (3-day-old) and old (15-18-day-old) embryonic heart cells, excepting the much smaller current and the slower onset of TTX action in young embryonic hearts.

Action Potentials↗

Population based cataract epidemiological surveys utilising a photodocumentation system.

For the past 10 years, the authors have performed cataract epidemiological surveys in several places. All of them were principally population based and applied new types of photodocumentation systems which were developed by our department. The survey places in Japan were Noto, our main survey field located in the centre of the main island of Japan, one village in the subtropical island of Okinawa, a village in the northern island of Hokkaido and one village (Bukittinggi) in West-Sumatra, Indonesia, very close to the equator. The survey methods applied including an interview and ophthalmological examinations, were almost identical in each place and the authors believe that the quality of the examinations was at high level. The cataract classification and grading systems applied were those established by the Japanese Co-operative Cataract Epidemiology Study Group. At present, no significant prominent difference of cataract prevalence and distribution of cataract types have been found in the three Japan survey places. The distribution of cataract types in the Indonesian subjects however, was different from the Japanese subjects. The lens transparency ratio in the Noto survey was quite similar to that of a Dutch study. From photographic images of both opaque and transparent lenses much objective information which be cannot detected through naked eye observation is obtainable. Furthermore, data obtained from the images are comparable because of their objectivity. Although the methodology seems to be rather sophisticated and is costly, the above advantages make it an important asset in this type of cataract research. For example, lens transparency changes with ageing can be indicated quantitatively from image analysis data.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

Right atrial hemangiopericytoma with hemopericardium during infancy.

A male infant with benign hemangiopericytoma of the right atrium is reported. His chief complaint was acute respiratory distress secondary to bloody pericardial effusion. Although the entire mass could not be removed surgically, there was no recurrence of cardiac tamponade or growth of the residual mass during a follow-up period of 3 years. This patient is, to our knowledge, the youngest one with primary cardiac hemangiopericytoma so far reported.

Echocardiography↗

3-Methoxy-4-aminoazobenzene, a unique carcinogenic aromatic amine as a substrate for cytochrome-P-450-mediated mutagenesis.

Rat liver microsomal enzyme(s) that catalyze mutagenic activation of a carcinogenic aminoazo dye, 3-methoxy-4-aminoazobenzene (3-MeO-AAB), was studied by virtue of the Salmonella typhimurium TA98 assay using o-aminoazotoluene (OAT) as the control. Male Wistar rats were pretreated with phenobarbital (PB), 3-methylcholanthrene (MC) or polychlorinated biphenyl (PCB), and the liver microsomal activities for mutagenic activation of 3-MeO-AAB and OAT were examined. In agreement with the reported results on several carcinogenic aromatic amines, MC pretreatment resulted in greater activation of microsomal activity in the OAT mutagenesis (about a 4-fold increase as compared to the untreated control) than did PB (1.5-fold increase). By contrast, the mutagenic activation of 3-MeO-AAB is found to be more efficiently catalyzed by those enzyme(s) that are induced by PB pretreatment (4-fold increase) than by those that are induced by MC (1.8-fold increase). The induced enzymes that principally mediate the mutagenic activation of these azo dyes are indicated to be cytochrome P-450s, because the mutagenic activation was strongly inhibited by addition of cytochrome P-450 inhibitors such as 2-diethylaminoethyl-2,2-diphenylvalerate (SKF 525A) and 7,8-benzoflavone. These data suggest that 3-MeO-AAB is a unique carcinogenic aromatic amine as a substrate for mutagenic activation via catalysis of those cytochrome P-450s that are induced by PB pretreatment.

Animals↗

Radioimmunoassay of urinary 3 beta-hydroxy-5-cholenoyl glycine in hepatobiliary disease.

A radioimmunoassay for 3 beta-hydroxy-5-cholenoyl glycine in human urine has been developed. The antiserum was elicited with the antigen in which the steroid hapten is linked to a bovine serum albumin through the C-19 position. The [125I]-tyrosine derivative of the hapten was used as radioligand. The standard curves were linear ranging from 10 to 320 ng/mL. The cross-reactivities with other bile acids were not detectable and below 0.3% with cholesterol. Sample preparation includes extraction of 3 beta-hydroxy-5-cholenoyl glycine from urine and solvolysis of the sulfates--main form present in urine. Urinary excretion of 3 beta-hydroxy-5-cholenoyl glycine was 0.373 +/- 0.133 mumol/day in healthy adults. Urinary excretion of 3 beta-hydroxy-5-cholenoyl glycine increased in chronic liver dysfunction, hepatoma and obstructive jaundice in this order.

Adult↗

Intracameral and lenticular penetration of locally applied stable isotope-labeled vitamin E.

PURPOSE: To confirm the aqueous humor and lens dynamics of 1% deuterium-labeled alpha-tocopherol acetate (D(3)-VEA) solution. METHODS: The concentrations of D(3)-VEA and D(3)-alpha-tocopherol (D(3)-VE), derived from D(3)-VEA, in the aqueous humor and lens were measured after continuous instillation of 1% D(3)-VEA into the cul-de-sac of rat eyes for 1 or 3 weeks. D(3)-VEA and D(3)-VE concentrations were determined by gas chromatography/mass selective detector. RESULTS: In the aqueous humor, the concentrations of D(3)-VEA and D(3)-VE were, respectively, 93.1 and 9.4 ng/mL after 1 week, and, respectively, 498.9 and 21.5 ng/mL after 3 weeks. In the lens, they were, respectively, 15.0 and 9.8 ng/g after 1 week, and 6.1 and 4.8 ng/g after 3 weeks. CONCLUSION: The penetration levels of alpha-tocopherol acetate by eyedrop application were confirmed in the aqueous humor and lens.

Administration, Topical↗

Location and severity of UVB irradiation damage in the rat lens.

We investigated the location and severity of lens opacities and epithelial alterations following ultraviolet-B (UVB) irradiation in vivo, using Brown Norway rats. A group of 9 rats received 65 mJ/cm2 UVB irradiation from overhead lamps every 6 days. Lens changes were documented and evaluated by an anterior eye segment analysis system. Lens epithelial cells were examined postmortem in flat preparations. After 8 weeks of the irradiation schedule (total dose: 0.6 J/cm2), an anterior polar opacity was apparent; at 16 weeks, the opacities had progressed more deeply into the cortex. At postmortem examination, cells in the central region displayed disorganization, clumping, some pyknotic nuclei and mitosis. There were deeper opacities and cell damage was more severe above the central horizontal plane than below it. This present study demonstrated that UVB damage differed in the superior and inferior parts divided by a horizontal plane through the lens anterior pole, when the UVB source was above and there was no reflection from below or laterally. The lens epithelial cells, and associated lens fibers, are the first target of UVB irradiation.

Animals↗

Ovo-testis and disturbed reproductive cycle in the giant abalone, Haliotis madaka: possible linkage with organotin contamination in a site of population decline.

Histological examination of gonads as well as chemical analysis of organotin compounds in tissues of the giant abalone, Haliotis madaka, was conducted to evaluate possible endocrine disruption and to consider the causal factors for the decline of abalone stocks in Japan. Abalone specimens were collected from two different areas, Tsushima as a reference site and Jogashima as a site representative of declining abalone populations, each month from September 1995 to November 1996. Scores were given to the development stages of reproductive cells in the ovary and testis. The degree of sexual maturation was evaluated by calculating the mean value of a histogram of these scores for the reproductive cells of each abalone. The temporal variations in degree of sexual maturation showed that female and male abalone from Tsushima matured synchronously, while those from Jogashima did not. The observed maximum reproductive developmental score in abalone from Jogashima was much lower than that from Tsushima, because immature females were present at the former site throughout the spawing season. Approximately 20% of the abalone from Jogashima were masculinized females with an ovo-testis. The masculinization of female abalone was similar to the imposex, typically induced in other gastropod molluscs by tributyltin (TBT) and triphenyltin (TPhT) from antifouling paints. Concentrations of TBT and TPhT in the muscles of abalone from Jogashima (n = 83) of 4.9 +/- 4.4 ng/g wet wt and 6.3 +/- 6.6 ng/g wet wt, respectively, were significantly higher than those from Tsushima (n = 125) (P < 0.01) of 0.8 +/- 0.8 ng/g wet wt and 0.6 +/- 1.3 ng/g wet wt, respectively. In situ exposure of abalone from Tsushima caged near a dockyard in Jogashima for 7 months (from the immature to the mature stage) resulted in spermatogenesis in the ovary of approximately 90% of females. Endocrine disruption may be caused in the giant abalone by organotin compounds from antifouling paints, which are possibly one of the causal factors for the decline of Japanese abalone stocks.

Animals↗

Tributyltin and triphenyltin induce spermatogenesis in ovary of female abalone, Haliotis gigantea.

Two-month flow-through exposure experiments of tributyltin (TBT) and triphenyltin (TPhT) were conducted with abalone, Haliotis gigantea. Nominal concentrations of 100 ng TBT/l and 100 ng TPhT/l caused significant spermatogenesis in ovaries of exposed females. There were also significantly more contracted primary oocytes observed in females exposed to either TBT or TPhT than controls. The incidence of two types of unknown cells was also significant in females exposed to TPhT. No significant histological changes were observed in testis of exposed males. This ovarian spermatogenesis caused by TBT and/or TPhT resembles gastropod imposex. Remarkably high concentrations of TBT and TPhT were observed in the head (including central nervous system ganglia), compared to muscles concentrations. Accumulation of TBT and TPhT in the head may disturb reproductive hormonal regulators through neuropeptides released from ganglia. This, as well as possible aromatase inhibition, may be one of the inducers for spermatogenesis in the abalone ovaries.

Animals↗