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Biomedical subjects

J Kondo

Publications and source records attributed to J Kondo.

At least 199 records · Page 11Linked to original sources
PubMed1986

Surgical techniques for giant retinal tears with retinal tacks.

In order to repair an inverted retinal flap on the choroid in case of retinal detachment with giant tears, the authors have developed a retinal tack made of acetalcopolymerisate. The tack is very durable and should remain inactive in the human body, owing to its stability under conditions of heat, alkali and acid. Manipulating the tack is adequately easy; the procedure and the tacks themselves appear to be well tolerated by the eye. The detailed design of the tack and its method of use are described in this report.

Adolescent↗
PubMed1986

[Study on developmental factors in anastomotic aneurysms].

All clinical cases of vascular reconstruction were reviewed to determine the various cases of anastomotic aneurysm. The subjects were all in-patients between 1963 and 1984 whose clinical courses were observed for more than 5 years following vascular reconstruction. Anastomotic aneurysms were found in 17 (6.4%) out of the 267 regions of anastomosis. These aneurysms were further studied by classifying them according to suture materials, primary cause of diseases, synthetic grafts and anastomotic regions, etc. The incidence of anastomotic aneurysms was lower when non-absorptive synthetic fibers were used. There was less frequency of anastomotic aneurysms when double velour Dacron was used for synthetic grafts. Due to the small number of cases, it was difficult to evaluate synthetic grafts when anastomosis was completed past the point of articulation, however the results obtained by velour type synthetic grafts were seemingly favorable. The results were not favorable, however, when end to side anastomosis was performed, since anastomotic aneurysm developed past the point of articulation in most cases. Thus the latter was conceivably responsible for the development of this disease. The findings of this research seem to indicate that the condition of the existing blood vessels is of more important consideration than the synthetic material used. In other words, examination of in vivo blood vessels for weaknesses due to degeneration and thromboendarterectomy is necessary. Thus, the region for the placement of synthetic grafts must be carefully selected. Also worthy of consideration is the intensity of the outer layers of the synthetic grafts whose organization may have been compromised to some extent in favor of an improved patency ratio, particularly in recent years.

Aneurysm↗
PubMed1985

Isocratic separation of PTH-amino acids at picomole level by reverse-phase HPLC in the presence of sodium dodecylsulfate.

The phenylthiohydantoin (PTH) derivatives of protein amino acids have been separated by reverse-phase high performance liquid chromatography (HPLC) on a fully end-capped C18 column using an isocratic solvent system. The developing solvent was 0.01 M sodium acetate buffer (pH 4.5) containing 39.5% acetonitrile and 0.02% sodium dodecylsulfate (SDS). With an automated liquid chromatography equipped with a dual-channel detector, operating at 254 and 313 nm, the present isocratic separation system was quite useful for routine microanalysis of PTH-amino acids released with a "gas-phase" sequencer. The time for one run was approximately 23 min and the limit of analysis approximately 2.5 pmol of a PTH-amino acid.

Amino Acids↗
PubMed1985

Direct Observation of Reversible and Irreversible Stomatal Responses of Attached Sunflower Leaves to SO(2).

The effects of SO(2) on stomatal aperture of attached sunflower leaves were observed with a remote-control light microscope system that permitted continuous observation of stomatal responses over periods of several hours. The relationship between actual stomatal aperture and stomatal conductance, measured with a porometer, also was examined on leaves before and after exposure to SO(2).A distinction between uninjured and injured regions was clearly visible on leaves after exposure to 1.5 microliters per liter SO(2) for less than an hour. During the exposure, the mean value of apertures for many stomata, which indicates stomatal conductance and transpiration rate, tended to decrease simultaneously in the uninjured and injured regions. However, the rate of decrease in the injured region was slower than that in the uninjured region because of a transient opening induced by water-soaking in the injured region. The transient opening was less common in stomata near veins and veinlets.There was a good correlation between pore width and stomatal conductance measured with a porometer before exposure to SO(2). This correlation continued in leaves exposed to SO(2) until visible, irreversible injury occurred, but then it disappeared.The results of these experiments indicate the necessity of continuous observation of individual stomata under the microscope to understand the effects of air pollutants such as SO(2) on stomatal behavior.

Journal Article↗
PubMed1985

[Experimental histopathological studies of electrical callus formation and mechanism of bone healing by direct micro-electrical current].

In order to get better understanding of the effects of electrical stimulation on bone healing processes, the author compared the healing processes of the femur in dogs between two groups: a stimulation group and a control group (non-stimulation group) which were experimentally prepared. These bone specimens were periodically extirpated and used for pathological examinations and X-ray micro-analysis. In the stimulation group, strong proliferation of osteoblasts and new trabecular formation in the bone marrow were observed at the 3rd day, and transition from fibrous to bony callus were noted at the 9th day; after the 3rd week bone remodeling was sparsely seen and bone healing period was shortened. In electromicroscopic observation, calcification of bone matrix and bone remodeling also seemed to be facilitated in this group. However, no marked differences in histological process of bone healing were observed between the stimulation group and the control group.

Animals↗
PubMed1984

Nucleotide sequence of the phoS gene, the structural gene for the phosphate-binding protein of Escherichia coli.

phoS is the structural gene for the phosphate-binding protein, which is localized in periplasm and involved in active transport of phosphate in Escherichia coli. It is also a negative regulatory gene for the pho regulon, and the gene expression is inducible by phosphate starvation. The complete nucleotide sequence of the phoS gene was determined by the method of Maxam and Gilbert (A. M. Maxam and W. Gilbert, Methods Enzymol. 65:499-560, 1980). The amino acid sequences at the amino termini of the pre-PhoS and PhoS proteins and at the carboxy terminus of the PhoS protein were determined by using the purified proteins. Furthermore, the amino acid sequence of enzymatically digested peptide fragments of the PhoS protein was determined. The combined data established the nucleotide sequence of the coding region and the amino acid sequence of the pre-PhoS and the PhoS proteins. The pre-PhoS protein contains an extension of peptide composed of 25 amino acid residues at the amino terminus of the PhoS protein, which has the general characteristics of a signal peptide. The mature PhoS protein is composed of 321 amino acid residues, with a calculated molecular weight of 34,422, and lacks the disulfide bond and methionine. The regulatory region of phoS contains a characteristic Shine-Dalgarno sequence at an appropriate position preceding the translational initiation site, as well as three possible Pribnow boxes and one -35 sequence. the nucleotide sequence of the regulatory region of phoS was compared with those of phoA and phoE, the genes constituting the pho regulon.

Amino Acid Sequence↗