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Biomedical subjects

N Aizawa

Publications and source records attributed to N Aizawa.

At least 19 recordsLinked to original sources

[Serum antibodies to rubella virus in healthy individuals with indirect immunofluorescent method].

To investigate sensitivity to rubella virus (RV) in healthy individuals, we examined levels of antibodies to RV in sera by an indirect immunofluorescence assay (IFA) and compared levels of antibodies by IFA with those by a hemagglutination inhibition (HI) assay. Of 114 healthy individuals, we detected antibodies to RV in serum specimens from 103 (90.3%) by IFA and in those from 109 (95.6%) by HI assay. The peak value of levels of antibodies by HI assay was 4 fold higher than that by IFA. When levels of antibodies by IFA were less than 32, levels of antibodies by HI assay ranged from < 8 to 1024. We did not detect anti-rubella antibodies of IgM class in all serum specimens and detected anti-rubella antibodies of IgA class in serum from only 1 individual by IFA. We detected antibodies to rubella in sera from 51 (94.4%) by IFA and in sera from 52 (96.3%) by HI assay of 54 individuals who reported having had rubella, and in sera from 23 (88.5%), by IFA and in sera from 26 (100%) by HI assay of 26 individuals reported having been vaccinated. Also, we detected anti-rubella antibodies in sera from 13 (76.5%) by IFA and in sera from 15 (88.2%) by HI of 17 individuals who reported having had neither rubella nor vaccination. In serum from 1 individual who reported having had rubella, we detected antibodies to rubella by IFA but not by HI assay. In serum specimens from 2 individuals who reported having had rubella vaccination, from 3 having had vaccination, from 2 having had neither rubella nor vaccination, we detected anti-rubella antibodies by HI assay but not by IFA. On the other hand, by both assays, we detected antibodies to RV in all sera of individuals who reported having had rubella and been vaccinated. The serodiagnosis, at least, by two methods is necessary to prevent individuals from rubella virus infection, because of following results: 1) influence of an inhibitor in serum specimens was thought to be variable. 2) The results measured by IFA were differed from those by HI assay in some individuals. 3) It is difficult in diagnosis of rubella from clinical symptoms alone. Also, it might be required to use vaccine to the individual who lacks detectable antibodies to rubella in serum by any method to prevent rubella infection.

Adult↗

Study on freezing process of killifish egg: utilizing the undercooled state for cryopreservation.

The purpose of this study is to find the feasibility of preservation of large cell and tissue by maintaining the undercooled state in a freezing process, leading to avoiding the growth of ice crystals in the intracellular space, which causes destruction of cell and tissue. The fertilized killifish egg was employed to test biological tissue. The cooling system was equipped with Peltier devices and able to decrease the temperature of the test section to -50 degrees C. The cooling rate could be regulated by the electric current supplied to the Peltier devices. In the temperature range 0 to -40 degrees C, the morphology of fertilized killifish egg was observed under a microscope with a cooling rate from 0.1 to 10 degrees C/min. The damage rate to the egg in the intracellular undercooled state was evaluated by hatching rate. As a result, intracellular undercooled states were observed in the freezing process with the extracellular undercooling and the extracellular freezing. Extracellular undercooling proves to preserve the egg, and extracellular freezing frequently damages the egg. Thus the cryopreservation of biological material is achieved by maintaining the undercooled state until the temperature of -40 degrees C, then is instantly frozen by the liquid nitrogen to avoid the growth of ice crystals. The maintaining of the stable undercooled state of biological material is requisite for the initial phase in the freezing process. Therefore, dehydration or maintaining the extracellular stable undercooled state should be desirable to maintain the intracellular undercooled state for cryopreservation of biological material.

Animals↗

[The usefulness of the emergency hepatobiliary scintigraphy to rule out acute cholecystitis--43 patients report].

We studied emergency hepatobiliary scintigraphy in the 43 patients to rule out acute cholecystitis. After injection of 185-222 MBq (5-6 mCi) of 99mTc-EHIDA or 99mTc-HIDA, serial static scintigraphic images were obtained up to 7 hours in maximum. Of 43 patients in this study, 20 had a normal scan and finally in all of them cholecystitis was ruled out. Of the 43 patients, 14 had an abnormal scan (nonvisualized gall bladder). In 10 of them the diagnosis of acute cholecystitis was confirmed after emergency cholecystectomy. The other 9 patients of 43 had an incomplete scan mainly due to liver dysfunction. Four of them had acute cholecystitis in the cholecystectomy. These results indicate that acute cholecystitis can be excluded by the findings of gall bladder visualization in hepatobiliary scintigram. We concluded that emergency hepatobiliary scintigraphy is very useful to rule out acute cholecystitis.

Acute Disease↗

[Clinical usefulness of scintigraphy with 99m technetium phosphates in rhabdomyolysis].

We performed bone scans with 99mTechnetium phosphates in 15 cases of clinically suspected rhabdomyolysis admitted to Chigasaki Tokushukai Hospital. Whole body scans were performed within 5 days from the onset of illness or admission. Accumulation of the radioactivity in the skeletal muscle was revealed in 13 of the 15 cases and the involved muscle groups were visualized vividly. Etiologies of rhabdomyolysis were diverse, ranging from malignant syndrome to sepsis. Myocardial concentration was absent in all of the cases. Renal concentration of the isotope was seen in cases where the degree of rhabdomyolysis was higher and renal impairment was present. We conclude that 99mTechnetium phosphate bone scan is useful in clinically suspected rhabdomyolysis as a diagnostic test and as a test to localize and quantitate the muscular involvement.

Adult↗

A large degenerated subserous leiomyoma of the uterus: uncommon scintigraphic and ultrasonographic findings.

Bone imaging is commonly used as a sensitive indicator of metastatic bone diseases or other bone pathology. Furthermore, it is now generally known that technetium-99m (99mTc) phosphonates tend to concentrate in various tissues other than bones. Ultrasonography is also widely used for the evaluation of pelvic masses. Ultrasonography is especially useful for detecting a cystic mass. We present a case where the uptake of 99mTc phosphonate compounds occurred in the entire abdomen, and ultrasonography suggested a diagnosis of pseudomyxoma peritonei, but the condition was later proven to be degeneration of giant subserous leiomyoma of the uterus. We have found two interesting features in this case. One is the 99mTc phosphonate concentration in the large cystic and hyaline degeneration of subserous leiomyoma of the uterus without calcification, and the other is the sonographic finding of a large echogenic mass with innumerable small anechoic areas. To our knowledge, no cases of 99mTc phosphonate concentration in non-calcified leiomyoma of the uterus have been demonstrated.

Adult↗

Bactericidal activity of M14659 enhanced in low-iron environments.

The bactericidal activity of M14659 against Escherichia coli in low-iron environments was investigated and compared with that of ceftriaxone and ceftazidime. The bactericidal activity of M14659 against E. coli in Mueller-Hinton broth was enhanced 30- to 20,000-fold by addition of transferrin, which is an iron-binding protein, whereas the activity of ceftriaxone or ceftazidime was much less strongly affected. This enhancement by transferrin was completely inhibited by saturating the iron-binding capacity of transferrin with FeCl3. M14659 was taken up markedly into bacterial cells in the presence of transferrin, and its uptake was inhibited by the protonophore dinitrophenol, which inhibits active-transport systems coupled to an energized membrane such as the iron transport systems of E. coli. The bactericidal activity of M14659, which chelates Fe3+, was also enhanced in the presence of other iron-binding compounds such as lactoferrin and alpha,alpha'-dipyridyl or in iron-deficient Mueller-Hinton broth (Fe3+ concentration, less than 2 nM) supplemented with FeCl3 at 0.1 to 1.0 microM, but not in unsupplemented iron-deficient Mueller-Hinton broth. The E. coli used in this study was confirmed to derepress iron transport systems in the presence of transferrin, lactoferrin, and alpha,alpha'-dipyridyl and in the iron-deficient Mueller-Hinton broth supplemented with FeCl3 at 0 to 1.0 microM. M14659 also showed an excellent antibacterial activity in vitro against other gram-negative bacteria in the low-iron environments. These findings indicate that M14659 may be actively taken up with Fe3+ into bacterial cells, probably through the iron transport systems under conditions of low iron and, thus, kills bacteria effectively.

Binding Sites↗

Role of angiotensin II in the pathogenesis of hyperdipsia in chronic renal failure.

The relation of thirst to the renin-angiotensin system was examined in 38 patients with chronic renal failure receiving hemodialysis treatment. They were classified into three groups, ie, group 1 (19 patients), no or modest thirst; group 2 (13 patients), moderate thirst; and group 3 (six patients), excessive thirst. The plasma renin activity, plasma angiotensin II levels, and interdialytic weight gains of groups 1 to 3 significantly increased in a progressive manner with intensity of thirst. The hyperdipsia experienced by four patients in group 3 ameliorated after administration of an angiotensin-converting-enzyme inhibitor. The hyperdipsia of some patients with chronic renal failure therefore appears to be mediated by increased production of endogenous angiotensin II.

Adult↗

Translocation of polychlorobiphenyls in soil into plants: a study by a method of culture of soybean sprouts.

PCB translocation from soil into a plant through its roots was investigated by a method of culture of soybean sprouts on sand contaminated with Aroclor 1242 or 1254. A preliminary culture was carried out on clean sand in a cage with small holes in the bottom and then followed by a main culture on contaminated sand after the preliminary culture cage was placed upon a box filled with the contaminated sand. Consequently, roots of soybean sprouts were allowed to penetrate through the holes at the botton of the upper cage into the contaminated sand. Rates of transference of PCBs were found to be different among chlorobiphenyl isomers; low chlorobiphenyls were much more preferentially absorbed by sprouts that were the high chlorobiphenyls. This seemed to depend mostly on different water solubilities of the isomers and probably not on selective absorption of the isomers by sprouts. The usefulness of the method employed of the two-steps sprout culture on doubly layered soil, in investigations of translocation mechanisms of toxic chemicals in a soil-plant ecosystem, is also discussed.

Aroclors↗