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Biomedical subjects

K Yoshimura

Publications and source records attributed to K Yoshimura.

At least 73 records · Page 4Linked to original sources
PubMed1991

[Long term follow-up on retinopathy of prematurity treated with photocoagulation--influence of photocoagulation on the eyeball].

The ocular findings in 127 eyes of 69 cases (average 11.6 +/- 3.7 years old) with retinopathy of prematurity (ROP) and treated with xenon photocoagulation between 1970 to 1983 were studied. Chorioretinal changes observed after the photocoagulation therapy revealed that photocoagulation spots gradually transformed from round to long oval forms in the sagittal direction. The photocoagulated lesions became extremely atrophic and larger after several years. In addition, band-shaped retinochoroidal atrophies were found adjacent to photocoagulation spots in 10 eyes (7.9%). Furthermore, vascular anastomoses between retinal and choroidal vessels were demonstrated at scars after treatment by fluorescein angiography. Anastomoses between retinal arteries and choroidal vessels were found in 18 eyes among 71 eyes (25.4%), and anastomoses between retinal veins and choroidal vessels were present in 50 eyes among the 71 eyes (70.4%). These changes may be the result of xenon photocoagulation on the developing premature retina and choroid. However, visual acuities were 0.7 or better in 111 eyes (87.4%). Refractions at the aged six years old were between - 3 to +2.75 diopters in the 94 eyes (83.9%) among the 112 eyes.

Adolescent↗
PubMed1991

[The relationship between ventilatory lung motion and pulmonary perfusion shown by ventilatory lung motion imaging].

Using ventilatory lung motion imaging, which was obtained from two perfusion lung scintigrams with 99mTc-macroaggregated albumin taken in maximal inspiration and maximal expiration, the lung motion [E-I)/I) of the each unilateral lung was studied in various cardiopulmonary diseases. The sum of (E-I)/I(+) of the unilateral lung showed a decrease in the diseased lung of localized pleuropulmonary diseases, including primary lung cancer and pleural thickening, and in both lungs in cases of heart diseases, diffuse pulmonary diseases including diffuse interstitial pneumonia and diffuse panbronchiolitis. The sum of (E-I)/I(+) of the both lungs, which correlated with vital capacity and PaO2, showed a decrease in diffuse interstitial pneumonia, pulmonary emphysema, diffuse panbronchiolitis, primary lung cancer, pleural diseases and so on. (E-I)/I(+), correlated with pulmonary perfusion (n = 49, r = 0.51, p less than 0.001), but not a few cases showed mismatch, which was observed in primary lung cancer, pleural diseases, pulmonary emphysema, diffuse panbronchiolitis and so on. (E-I)/I(+) better correlated with pulmonary ventilation by ventilation scintigraphy with 81mKr or 133Xe (n = 49, r = 0.61, p less than 0.001) than pulmonary perfusion. The ventilatory lung motion imaging, which demonstrates the motion of the intra-pulmonary areas and lung edges, appears useful for estimating pulmonary ventilation of the perfused area as well as pulmonary perfusion.

Heart Diseases↗
PubMed1990

Production, purification and characterization of biologically active recombinant human nerve growth factor.

The human NGF gene was isolated and inserted downstream from murine leukemia virus LTR in a plasmid having dihydrofolate reductase cDNA. The expression plasmid was introduced into CHO cells. Selection of the transformants for the resistance to methotrexate gave a CHO cell line which produced human NGF at a level of 4 mg/L in the culture medium. The recombinant human NGF was purified to near homogeneity from the culture supernatant. The NH2-terminal amino acid sequence, the COOH-terminal amino acid (Ala), and the amino acid composition of the human NGF were identical to those deduced from the nucleotide sequence of the human NGF gene. The recombinant human NGF was composed of 120 amino acid residues. Three disulfide linkages were determined to be Cys15-Cys80, Cys-58-Cys108, and Cys68-Cys110; the locations were identical to those in the mouse 2.5S NGF molecule. The specific biological activity of the recombinant human NGF was comparable with that of authentic mouse 2.5S NGF as determined by stimulation of neurite outgrowth from PC12 cells.

Amino Acid Sequence↗
PubMed1990

Cloning and expression of a cDNA encoding a novel human neurotrophic factor.

A cDNA encoding a novel human neurotrophic factor (designated nerve growth factor-2; NGF-2) was cloned from a human glioma cDNA library using a synthetic DNA corresponding to human nerve growth factor (NGF). The cloned cDNA encodes a polypeptide composed of 257 amino acid residues including a prepro-sequence of 138 residues and a mature region of 119 residues. The amino acid sequence of human NGF-2 exhibits 58% similarity with that of human NGF. Conditioned medium of COS-7 cells transfected with an expression plasmid for human NGF-2 cDNA supported the survival of sensory neurons isolated from dorsal root ganglia of embryonic chicks. A 1.5 kb of NGF-2 mRNA can be detected from an early development stage in rat brain, by Northern blotting analysis.

Amino Acid Sequence↗
PubMed1990

A monoclonal antibody 5E5 recognizes an intranuclear antigen selectively present in a subpopulation of the neurons.

Monoclonal antibody 5E5 labeled the nuclear antigen of the neurons in the guinea pig and rat central nervous systems including the cerebrum, cerebellum, spinal cord and retina. This antibody could discriminate neurons even among the same cell class. In in vitro study, only 10% of dividing PC12 cells was labeled with this antibody. An electron microscopic immunohistochemical study also revealed that this antibody selectively labeled heterochromatins in the neurons. Although we could not obtain any positive result by an immunoblot study, the antigenicity was remarkably diminished by the DNase I or S1 nuclease treatment on the tissue sections whereas RNase and trypsin was ineffective. These results suggested that this antigen might be a single-stranded DNA-protein complex resistant to proteolytic procedures, and possibly related to cell function or state of differentiation.

Animals↗
PubMed1990

Alteration in density of eosinophils in the cerebrospinal fluid of mice infected with Angiostrongylus cantonensis.

The density of eosinophils in the cerebrospinal fluid (CSF) and blood of male ddY mice infected with Angiostrongylus cantonensis was examined on days 14, 20 and 27 post-infection (p.i.) with discontinuous Percoll gradient centrifugation. Normal blood eosinophils had a density of between 1.070 and 1.080 g ml-1. No significant changes in density in blood eosinophils were noted during the course of the observations. CSF eosinophils began to become hypodense (defined as density less than 1.070 g ml-1) on day 20 p.i., and 88% of eosinophils were hypodense on day 27. Our results suggest therefore that eosinophils probably become hypodense in the CSF and brain tissues, but not in the blood.

Angiostrongylus↗
PubMed1990

Solitary neurofibroma of scrotum.

We report a case of solitary neurofibroma of the scrotum. These tumors, which arise from perineural and Schwann cells, commonly occur throughout the body but they rarely have been reported to originate in the scrotum. No stigmata of von Recklinghausen's disease were identified.

Adult↗
PubMed1990

Differences in responses of rat- and guinea-pig-eosinophils to eosinophil chemotactic factors derived from Angiostrongylus cantonensis.

Eosinophil chemotactic activity associated with whole worm extracts of the young adult worms (YA) and 1st stage larvae (L1) of Angiostrongylus cantonensis was assessed using guinea-pig- and rat-eosinophils. Both whole worm extracts were potently chemotactic to guinea-pig-eosinophils whereas only the whole worm extract of L1 was chemotactic to rat-eosinophils. Gel filtration chromatography of YA-whole worm extract yielded an eosinophil chemotactic factor (ECF-YA) with an estimated molecular weight of 16,900. ECF-YA was resistant to heating and pronase digestion but sensitive to periodate oxidation, suggesting that chemotactic activity was possibly associated with the sugar portion of the glycoprotein molecule. Guinea-pig- and rat-eosinophils were deactivated by previous incubation with homologous whole worm extracts but not with heterologous ones. When guinea-pig-eosinophils were treated with trypsin or pronase, their chemotaxis to ECF-YA was significantly inhibited, and pronase treatment was more effective. Both deactivated and trypsin-treated guinea-pig-eosinophils completely recovered their chemotaxis responses after in vitro culture for 12 and 24 h, respectively. When those eosinophils were cultured in vitro in the presence of puromycin or cycloheximide, however, their chemotaxis responses could not be recovered. These data clearly indicate that guinea-pig-eosinophils probably possess a kind of receptor (or 'recognition unit') capable of reacting to ECF-YA, and also that the receptor may be protein or glycoprotein molecules, and reproducible.

Angiostrongylus↗
PubMed1990

Neonatal tuberous sclerosis with heart and brain tumors.

A 6-day-old neonate with tuberous sclerosis having brain and cardiac tumors is reported. The patient presented with a seizure 20 minutes after birth. Cranial ultrasonography and computed tomography on admission showed a large and round high-density tumor lesion in the left frontal lobe. Echocardiography also showed a large tumor lesion beside the left ventricle wall, and a diagnosis of tuberous sclerosis was promptly made. Two months later, a periventricular calcified lesion was found on the demonstrated portion, and the tumor lesion initially observed in the brain had disappeared. These findings suggest that the initial tumor lesion found in the brain developed into a typical calcified lesion.

Brain Neoplasms↗
PubMed1990

Hyperammonemia in multiple myeloma.

Two patients with multiple myeloma who appeared to be producing ammonia are reported. Both patients showed hyperammonemia and amino acid disturbances, such as a low Fischer ratio. One patient had Bence Jones protein (lambda) type myeloma and became comatose, but the hyperammonemia and disturbance of consciousness were improved by chemotherapy for the myeloma. The other patient had IgA kappa type myeloma and somnolence and died of malignant pleurisy despite intensive chemotherapy. Autopsy showed widespread multiple myeloma and an almost normal liver. Ammonia levels in the supernatant of cultured myeloma cells from the patient's pleural effusion increased almost linearly from the time of cell seeding. These observations showed that ammonia was produced at a high level by these human myeloma cells. We also found that one of the common myeloma cell lines, RPMI 8226, could produce ammonia as well.

Amino Acids↗
PubMed1990

Effects of nitrendipine and hypoxia on pulmonary vascular resistance in experimental emphysema.

We evaluated the hemodynamic effects of nitrendipine, a dihydropyridine Ca2+ channel blocker, and hypoxia in intact dogs with emphysema produced by treatments with aerosolized papain. We also determined the effects of emphysema, chronic Ca2+ channel blocker treatment, and acute hypoxia on the distribution of vascular resistance in isolated left lower lobes. Pulmonary vascular resistance was increased (4 +/- 1 mm Hg/L/min) in the animals studied 6 months after receiving 4 weekly treatments with papain compared with control animals (2.6 +/- 0.6 mm Hg/L/min, p less than 0.05), and this effect of emphysema was blunted with chronic nitrendipine, 3 mg/kg twice a day (3.1 +/- 0.9 mm Hg/L/min). Both at baseline and at 6 months, hypoxia-induced increases in pulmonary vascular resistance were abolished by nitrendipine. The total pulmonary pressure gradient (delta Pt) was partitioned into pressure gradients across arterial (delta Pa), middle (delta Pm), and venous (delta Pv) vessels by occlusions performed during normoxia (PIO2 = 200 mm Hg) and hypoxia (PIO2 = 30 mm Hg). Papain-treated animals had elevated delta Pt compared with that in control animals because of an increased delta Pv (9.7 +/- 1.1 mm Hg versus 5.2 +/- 0.4 mm Hg in control animals, p less than 0.05). In contrast, only delta Pm was increased with papain + nitrendipine (2.6 +/- 1.0 mm Hg versus 0.2 +/- 0.3 mm Hg in control animals, p less than 0.05). An increase in the downstream pressure gradient was also observed when lobes from animals with emphysema were studied under conditions of reverse perfusion. Hypoxic responses were similar in the control and papain groups, with increases in delta Pa and delta Pm.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1990

Transient behavior of sea urchin sperm flagella following an abrupt change in beat frequency.

Within the approximate range of 30-80 Hz, the flagellar beat frequency of a sea urchin sperm held by its head in the tip of a micropipet is governed by the vibration frequency of the micropipet. We have imposed abrupt changes in flagellar beat frequency by changing the vibration frequency of the micropipet within this range and used a high-speed video system to analyze the flagellar wave parameters during the first few cycles following the change. Our results demonstrate that the various flagellar beat parameters differ in the time they take to adjust to the new conditions. The initiation rate of new bends at the base is directly governed by the frequency of the vibration and changes immediately to the new frequency. The length and the propagation velocity of the developed bends become adjusted to the new conditions within approximately 1 beat cycle, whereas the bend angles take more than 4 beat cycles to attain their new steady-state value. Bends initiated shortly before the change in frequency occurs attain a final length and angle that depends on the relative durations of growth at the old and new frequencies. Our results suggest that the flagellar wavelength and bend angle are regulated by different mechanisms with the second not being directly dependent on bend initiation.

Animals↗
PubMed1990

[Upper urinary tract tumors following bladder cancer].

We treated in total 795 patients with primary transitional cell carcinoma of the urinary bladder between April, 1964 and December, 1988. Eighteen patients of them had upper urothelial cancer during the follow-up period. Thirteen of the 18 patients had received transurethral resection for the initial bladder cancer, while 3 total cystectomy and 2 segmental resection. The over-all incidence of bladder cancer patients who subsequently developed upper urinary tract tumors was 2.3 per cent. The interval between initial treatment of the bladder cancer and treatment for the upper urinary tract tumor ranged from 2 to 74 months (median 20 months). The five-year survival rate after treatment for the upper urinary tract tumor was 31.7 per cent. We conclude that the following are high risk patients for development of upper urinary tract recurrences: 1) patients with bladder cancer near orifices, 2) patients with recurrent bladder cancer under bladder preserving treatment for a long time, 3) patients with G2 multifocal bladder cancer.

Aged↗
PubMed1990

Clostridium botulinum in the soil of Paraguay.

Seventeen soil samples of Paraguay were examined for the presence of Clostridium botulinum. Botulinum type A, C1 and F toxins were detected in soil cultures. Type E toxin was not detected in any of soil cultures including those from river and lake shores.

Botulinum Toxins↗
PubMed1990

[A case report of pleural involvement in primary macroglobulinemia].

A case of primary macroglobulinemia with pleural and gastric involvement was presented. A 48-year-old female was admitted with productive cough. On physical examination neither lymphoadenopathy nor hepatosplenomegaly were found. In addition, no bleeding tendency nor disturbance of the visual acuity were detected. Her chest roentgenogram showed a moderate amount of pleural effusion in the left pleural cavity without infiltration in the lung fields and no evidence of swollen hilar or mediastinal lymphnodes. A monoclonal M-band of to IgM-kappa type was observed in her serum and the pleural effusion. The diffuse ulcerative lesion in the gastric mucosa was detected by gastrofiberscopy. The lymphoid cells taken from the pleural effusion and the gastric mucosa stained positively with fluorescein-conjugated antiserum to u or the kappa chain. Pleural effusion and gastric infiltration of lymphoid cells improved remarkably following ACOP therapy.

Female↗
PubMed1990

[Massive traumatic hematoma localized in the basal ganglia: treatment by CT-guided stereotactic aspiration surgery].

A case of massive traumatic hematoma of the basal ganglia which was treated successfully by CT-guided stereotactic aspiration surgery, was reported. A 6-year-old boy was admitted 2 hours after a traffic accident. He had no neurological focal signs except for disturbance of consciousness on admission. CT scan revealed a massive hematoma in the right basal ganglia. His neurological status gradually deteriorated 6 hours after the trauma and the size of the hematoma increased on serial CT scan. Then, CT-guided stereotactic aspiration surgery was performed and about 15.5 ml of hematoma clot was successfully evacuated. He made an uneventful recovery from the operation and gradually improved. The final outcome was that he showed moderate disability at 3 months after the trauma. The possible mechanism of development of hematoma in this lesion, and indication of CT-guided stereotactic aspiration surgery were also discussed.

Basal Ganglia Diseases↗
PubMed1990

Metastatic tumor of the spermatic cord from renal cell carcinoma.

A 56-year-old male visited our hospital with macroscopic hematuria. Physical and X-ray examinations showed he had right renal cell carcinoma with tumor thrombosis in the inferior vena cava and the right spermatic vein. Radical nephrectomy and tumor thrombectomy were performed and he was discharged with no evidence of disease 1 month after the operation. At 5 months after the discharge, he noticed a palpable mass in the scrotum. Right orchiectomy was performed. The tumor was located in the right spermatic cord and histological examination revealed it to be a renal cell carcinoma (clear cell subtype) which was a metastatic lesion from a right renal tumor. In this case, the renal cell carcinoma was considered to have retrogradely metastasized through the spermatic vein. In conclusion, a complete physical examination, including the spermatic cord is recommended during the follow-up period of renal cell carcinoma.

Carcinoma, Renal Cell↗