Biomedical subjects

Y Baba

Publications and source records attributed to Y Baba.

At least 451 records · Page 25Linked to original sources

PubMedDate not supplied

Clinical study of varicocele by sequential scrotal scintigraphy.

Sequential scrotal scintigraphy was used to study testicular blood flow in 122 patients with clinically diagnosed varicocele. The sensitivity of scrotal scintigraphy was 91.7% on the whole sequential images. The late-phase image was superior in sensitivity to that of the early-phase images. The difference in time between the arrival of radioactivity in the iliac artery and in the pampiniform plexus grew shorter with increasing grade of varicocele. Time-activity curves were classified into four patterns. One type (Type 3), which was more frequently observed in grade II and grade III varicocele than grade I varicocele, showed a decreased arterial perfusion of the left side lesion. It is concluded that scintigraphic analysis using both sequential images and time-activity curves is not only highly representative of the grade of clinically palpable varicocele, but also provides a better understanding of local hemodynamics in the scrotum.

Adolescent↗

PubMedDate not supplied

Flow cytometric DNA analysis demonstrates contralateral testicular deterioration in experimental unilateral testicular torsion of prepubertal rats.

It has been postulated that unilateral testicular torsion causes damage to the contralateral testis and reduces fertility. However, in animal studies such an effect has not been fully proven by histopathologic examination or other conventional assays of spermatogenesis. We investigated the effect of unilateral testicular torsion on contralateral spermatogenesis in prepubertal rats using quantitative flow cytometric DNA analysis. Male rats were divided into three groups which underwent sham-operation, simple hemiorchiectomy or unilateral testicular torsion. Five weeks after these operations, fertility and spermatogenesis by flow cytometry were evaluated. No significant differences were observed in body weight, contralateral testicular weight or serum testosterone concentration among the three experimental groups. In the torsion group, mean seminiferous tubular diameter, number of foetuses, fertility rate and percentage of haploid cells were all significantly decreased compared to the other two groups. These results suggest that unilateral testicular torsion causes damage to the contralateral testis and consequently can reduce the future fertility of prepubertal rats.

Animals↗

PubMedDate not supplied

Quantitative analysis of spermatogenic DNA synthesis in the rat using a monoclonal anti-5-bromodeoxyuridine antibody.

The utility of the 5-bromodeoxyuridine (BrdUrd) labelling technique for the quantitative analysis of spermatogenic deoxyribonucleic acid (DNA) synthesis was investigated in the rat. Rat testicles were labelled by a single intraperitoneal injection of 100 mg kg-1 of BrdUrd. The testicles were removed 1 h after injection, fixed in Bouin's fluid and embedded in paraffin. BrdUrd-labelled cells were detected by immunohistochemical staining using a monoclonal anti-BrdUrd antibody. The number of BrdUrd-labelled tubules per total number of tubules (percent L.T.), the number of BrdUrd-labelled cells per total number of tubules (tubular ratio) and the number of BrdUrd-labelled cells per number of Sertoli cells (Sertoli cell ratio in BrdUrd-labelled cells) were calculated as indices of spermatogenic DNA synthesis during each stage of the seminiferous epithelial wave. BrdUrd labelling was found exclusively in the nuclei of spermatogonia and in preleptotene spermatocytes in the seminiferous epithelium. The percent L.T. was generally greater than 50%, except in stages VI, VII and XIV, and the tubular as well as Sertoli cell ratios in BrdUrd-labelled cells was greater than 2.0 and 0.15, respectively, in stages I, II-III, V, VIII, X, and XII. The tubular ratio and Sertoli cell ratio in BrdUrd-labelled cells along the seminiferous epithelial wave had two distinct peaks. The distribution of the tubular ratio using the BrdUrd-labelling technique correlated well with the distribution previously established by measuring tritiated thymidine uptake per tubule. Thus, the BrdUrd labelling technique, which is more efficient than the tritiated thymidine labelling technique, can be used to quantitatively evaluate spermatogenic DNA synthesis.

Animals↗

PubMedDate not supplied

Readiness potentials recorded from the scalp and depth leads.

Readiness potentials on voluntary hand movements were recorded from the scalp (C3, C4), premotor cortex, subcortical white matter and VL nucleus of the thalamus. Subjects were healthy right-handed men and patients with involuntary movement disorders. We obtained a slow negative shift of brain electrical potentials from the scalp and cortex preceding voluntary hand movements. The mean time interval between the onset of the readiness potential and the onset of motor activity (mean T) was 0.8 sec on right hand movements and 1.0 sec on left hand movements in healthy men. In cases with parkinsonism, the mean T value was 1.4 sec in patients with akinesia, 1.1 sec in those without akinesia. The amplitude of readiness potentials was higher in the scalp contralateral to the hand movement. The readiness potentials recorded from the VL nucleus and white matter were reversed in polarity from those of scalp and cortex. Simultaneous recordings from cortex and VL nucleus showed early onset of readiness potentials from the cortex by approximately 0.1 sec compared with the VL nucleus.

Brain Mapping↗

PubMedDate not supplied

Membranocystic lesion in sclerosing lipogranuloma of the scrotum: an ultrastructural study.

Two cases of intrascrotal sclerosing lipogranuloma are reported in which affected adipose tissues showed peculiar membranocystic lesions (MCL) similar to the features described in Nasu-Hakola disease. On light microscopy, the MCL were seen in the degenerative fatty tissues and within multinucleated giant cells, which were positive for periodic acid-Schiff stain and resistant to diastase digestion. Ultrastructurally, two types of MCL were observed; one type was characterized by thick membranes composed of vesicular to minute tubular or fibrillar substructures, and the other type was characterized by thin membranes composed of only small numbers of tiny vesicles. The substructures in both types of MCL contained lipid droplets similar to those in the inner space. These results support the concept that the membranes in the MCL are derived from degenerated fat droplets.

Adult↗

PubMedDate not supplied

Radiation therapy of primary malignant lymphoma of the brain.

Primary malignant lymphoma of the brain (PMLB) is uncommon. Between 1975 and 1982, the authors observed 11 patients with histologically confirmed PMLB. Mean survival after radiation therapy was 7 months with 5 patients surviving for more than 2 years. Multifocal lesions were seen in 9 patients and spontaneous regression was seen at computed tomography in 2 patients. Radiation doses in excess of 30 Gy controlled the primary tumor, but intracranial recurrences occurred even after whole brain irradiation to 40 Gy. Only one patient had a relapse outside the central nervous system, and none had clinical evidence of seeding to the spinal canal. The authors postulate that PMLB usually is a multifocal intracranial disease, and that whole brain irradiation of at least 30 to 40 Gy should be given to all patients with this disease.

Adult↗

PubMedDate not supplied

Treatment of retinoblastoma with argon laser photocoagulation.

Treatment of retinoblastoma with argon laser photocoagulation in a five-month-old boy is described. His right eye had been enucleated for a large retinoblastoma. A small lesion in the left eye was successfully treated with argon laser. The patient has retained good vision without any complication and there has been no evidence of recurrence for four years.

Argon↗

PubMedDate not supplied

A case of follicular thyroid cancer with tracheal stenosis responded to external radiation therapy.

We report the case of a 70-year-old man with follicular carcinoma of the thyroid who complained of worsening dyspnea and was successfully treated by external radiation therapy. The total dose given was 61 Gy in 28 fractions. This case suggests that external radiation therapy is effective for the management of differentiated thyroid cancer with critical stenosis of the trachea that is inoperable and difficult to treat with radioiodine.

Adenocarcinoma, Follicular↗

PubMedDate not supplied

A comparison of hepatocellular carcinoma associated with HBV or HCV infection.

BACKGROUND/AIMS: Close relationships between hepatocellular carcinoma (HCC) and hepatitis virus infection have been elucidated. However, clinical differences between HBV- and HCV-associated HCC remain unclear. METHODOLOGY: Four hundred and sixteen patients with HCC were examined for both HBsAg and HCV-Ab. Sixty-nine of the 416 patients (16.6%) were positive for HBsAg and negative for HCV-Ab (B-HCC), while 290 patients (69.7%) were negative for HBsAg and positive for HCV-Ab (C-HCC). Various comparisons were made between the 2 groups. RESULTS: B-HCC patients were younger in age (p < 0.0001), and had significantly better liver function than C-HCC patients. The motivation of HCC detection was different between the 2 groups (p < 0.0001), and the tumor size of B-HCC was significantly larger when comparing groups with regard to symptoms (p < 0.05). Although B-HCC demonstrated better survival in Stage I/II treated by surgery (p < 0.05), it was associated with poorer survival in Stage III/IV receiving hepatic arterial infusion chemotherapy when compared to C-HCC (p < 0.01). CONCLUSIONS: These results suggest that clinical differences between B-HCC and C-HCC may depend upon the difference of the natural course between HBV and HCV infection, and B-HCC may be more resistant to treatment than C-HCC in the advanced stage. This also illustrates the need for early tumor detection in B-HCC.

Carcinoma, Hepatocellular↗

PubMedDate not supplied

Differential diagnosis of small round cervical lymph nodes: comparison of power Doppler US with contrast-enhanced CT and pathologic results.

PURPOSE: The purpose of this study was to differentiate reactive small round lymph nodes (SRLNs) from metastases by power Doppler ultrasonography (PD-US) and contrast-enhanced CT (CE-CT). MATERIALS AND METHODS: Both PD-US and CE-CT were performed in 99 cervical lymph nodes (LNs) with a maximum diameter of 1.5 cm or smaller and maximum longitudinal/transverse ratio of 1.5 or smaller in 76 patients with head and neck cancer. At pathologic examinations, 45 were reactive and 54 were metastatic LNs. The vascular patterns on PD-US were classified as hilar, avascular, peripheral, and miscellaneous vascular patterns. The enhancement patterns on CE-CT were classified as homogeneous, heterogeneous, and ring enhancement. RESULTS: On PD-US, the hilar pattern was more frequently associated with benignancy (91%) and the peripheral, miscellaneous vascular pattern with malignancy (91%). The avascular pattern included both benign (58%) and malignant (42%) LNs. On PD-US, accuracy was 85%. On CE-CT, ring enhancement showed metastasis (100%), and these LNs showed avascular or peripheral patterns on PD-US. On CE-CT, accuracy was 77%. When information on CE-CT results was added to PD-US results, the accuracy rate increased significantly, to 94% (p=0.01). CONCLUSION: Vascular patterns evaluated with PD-US and enhancement patterns on CE-CT can characterize SRLNs. For an avascular pattern on PD-US, information on CE-CT results can significantly increase the accuracy of characterization.

Adult↗

PubMedDate not supplied

Analysis of T-2 toxin metabolites in tissues and excreta of rats.

In previous journal articles, we have demonstrated that microsomal carboxyesterase deacetylated specifically the C-4 acetyl residue of T-2 toxin and the resulting HT-2 toxin was an end product of the in vitro system. In an attempt to confirm this evidence in the in vivo system, we have analyzed the metabolism of T-2 toxin in rats. Male rats received orally 2-5 mg/kg of T-2 toxin, and the contents of T-2 toxin, HT-2 toxin, and neosolaniol in the liver, kidney, and serum were analyzed by using GLC method. The data revealed that HT-2 toxin was found in the liver shortly after the administration, and neither T-2 toxin nor neosolaniol was detected in the tissues. Blue spot test on TLC by using 4-(p-nitrobenzyl)pyridine revealed the presence of HT-2 toxin and T-2 tetraol in the urine and HT-2 toxin in the feces.

Animals↗

PubMedDate not supplied

Pathogenesis of varicocele: experimental study using flow cytometric DNA analysis.

Despite extensive investigation, a cause-and-effect relationship between varicocele and male infertility has not been fully proven. We investigated the effect of a unilateral varicocele on both testes. Spermatogenesis in the rats with a surgically induced left varicocele was evaluated 5 weeks postoperatively by measurement of testicular weight, flow cytometric DNA analysis and evaluation of the mean seminiferous tubular diameter (MSTD). In rats with varicoceles, the testicular weight, the percentage of haploid cells and the MSTD were decreased in both testes in contrast to sham-operated rats. There was a greater decrease on the left side. These results suggest that unilateral varicocele may impair spermatogenesis in both testes, with the impairment being greater on the ipsilateral side.

Animals↗

PubMedDate not supplied

The role of radiation therapy in adult T-cell leukemia.

Five patients with adult T-cell leukemia (ATL) were treated by irradiation. Of the five patients, four were irradiated only locally to enlarged lymph nodes or cutaneous lesions as a palliative therapy. The other patient was given a single dose of 10 Gy to the total body as a definitive treatment, followed by autologous bone marrow transplantation. All five patients were treated by combined chemotherapy before irradiation. Complete reduction of lymph node enlargement and cutaneous lesions was achieved with a dose of 20 to 30 Gy. Four patients died within three months after radiotherapy, but there was no recurrence in the radiation field while new lesions developed. One patient in whom cutaneous lesions developed again after nine months of remission was alive at 10 months after irradiation. These patients responded poorly to chemotherapy. Local lesions produced by ATL were sensitive to irradiation and could be controlled by moderate irradiation doses without severe side effects. Radiotherapy did not prolong survivals, but it should be considered as a palliative method in multimodal treatment for ATL.

Adult↗

PubMedDate not supplied

Radiation and thermal characteristics of mouse lymphoma cells and their radiation-sensitive mutant.

Radiation and thermal characteristics of L5178Y cells and their radiation-sensitive mutant M10 cells were studied by the colony-forming method and the dye-exclusion method using eosin-Y. Although M10 cells were remarkably radiation-sensitive compared with L5178Y cells, it was difficult to cause interphase death of M10 after a large dose of irradiation. After heat treatments, L5178Y cells revealed more cell destruction and were stained well by eosin-Y, but it was relatively difficult to produce cell destruction of M10 cells, which showed poor staining by eosin-Y. When assayed by the colony-forming method, M10 cells were also heat-resistant compared to L5178Y. The dye-exclusion rate was closely correlated with cell survival after hyperthermia of L5178Y cells, suggesting that this is a simple method of detecting the thermosensitivity and thermotolerance of cancer cells. The difference in survival of L5178Y cells and M10 cells after combined treatment with gamma irradiation and hyperthermia was smaller than with gamma irradiation alone. It was also found that there was a relationship between radiation-induced interphase death and hyperthermia-induced interphase death, and that interphase death accounted for a major part of cell death caused by hyperthermia in mouse leukemia cells.

Animals↗

PubMedDate not supplied

Experimental and clinical evaluation of a prototype hyperthermia system.

In order to achieve better thermal distribution, a high output radiofrequency capacitive heating system was developed for hyperthermia and operated at a frequency of 13.56 MHz with an output of 1,000 watts (Inter Nova Inc., IH-1000). With use of this equipment, an agar phantom study, an animal experiment, and a clinical trial have been performed. This unit has made it possible to use large applicators with large electrodes. The phantom study revealed homogeneous, deep-heating capability. In the animal study using a miniature pig, good thermal distribution within the body was obtained, but the problem of overheating the subcutaneous fat layer remained. In the clinical application, some limiting factors remained unsolved in spite of our attempts to eliminate them; however, the problem of insufficient power supply was solved.

Animals↗

PubMedDate not supplied

Clinical evaluation of combined hyperthermia and radiation therapy for radioresistant superficial malignant tumors.

From January 1985 to October 1986, 25 tumors in 23 patients were treated with combined hyperthermia and radiation therapy. All of these tumors were recurrent tumors after initial radiation therapy, and were presumed to be radioresistant tumors on the basis of histological findings and poor response at 30-40 Gy. Heat was delivered using the radiofrequency of 13.56 MHz at 500 W or 1000 W. In combination with radiation therapy, hyperthermia was given at 42 degrees-43 degrees C for 30 minutes per fraction once a week for a total of four to five fractions (Protocol 1), or twice a week for a total of six to 10 fractions (Protocol 2). Hyperthermia once a week was as effective as twice a week. Small and diffuse tumors showed better results. Combined therapy was better than irradiation alone for suppression of these tumors. The adverse effects included three subcutaneous fat necroses with an associated lipoma in one case and three skin ulcers.

Adult↗

PubMedDate not supplied

An implantable left ventricular assist system with an electrical impedance monitoring and control system.

The authors developed an implantable left ventricular assist system (LVAS) for bridge to transplant of rather small sized adults. The pump was made of segmented polyether polyurethane and was 86 mm in diameter, 50 mm in height, with a 70 ml nominal stroke volume. A percutaneous drive line was connected with an external pneumatic control drive unit (CDU). In chronic animal experiments using 11 adult goats, the pump was installed between the LV apex and the descending aorta and was placed in the abdominal wall. Five goats were killed after 4 to 14 weeks while in good physical condition, and one is ongoing. There were no prominent thromboembolic symptoms despite no anti-thrombogenic agent being used. The new electrical impedance-based monitoring and control system (Z system) was installed in the CDU. In this Z system, automatic calibration was performed periodically for several seconds while the drive condition was changed to ensure full-fill of the blood pump. The full-fill to full-empty drive was well controlled by this Z system. In conclusion, the new Z system is practical and useful for monitoring and control of an implantable pump, giving this LVAS a promising place in clinical use.

Adult↗

PubMedDate not supplied

A two stage axial flow pump. New approach to reduction of hemolysis.

From an engineering point of view, the suitable revolution number for high efficiency operation of an axial flow pump is known. A multistage axial flow pump is a useful tool for reducing revolution number with a high efficiency axial flow pump. A two stage (25) axial flow pump designed at a 5 L/min flow rate and a 100 mmHg pressure head was evaluated in three kinds of in vitro hemolysis tests. Each stage design point of the 2s pump was tested at a 5 L/min flow rate and a 50 mmHg pressure head. Specific speed and revolution number of the 2S pump were 1400 rpm, m3/min, m, and 15500 rpm, respectively. In the first test the 2S pump was compared with two single stage axial flow pumps (1S-A and 1S-B100) designed by the same method. The specific speed of the 1A was the same as that of the 2S pump, which was driven at 26000 rpm. The impeller of the 1S-B100 was the same as that of the 2S pump, which was driven at a 22000 rpm RN and a 1100 specific speed. The 2S pump was separated into two single stage axial flow pumps and the effect of series operation on hemolysis was evaluated in the second test. In the third test the 2S pump was compared with the 1S-B100 by using diluted goat blood samples with three different hematocrit values. The results showed that the hemolysis index of the 2S pump, regarded as a total hemolysis index of both stage axial flow pumps, was less than those of the single stage axial flow pumps at all hematocrit values.

Animals↗