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Biomedical subjects

T Kurata

Publications and source records attributed to T Kurata.

At least 325 records · Page 18Linked to original sources

The use of mice in the Sereny test as a virulence assay of shigellae and enteroinvasive Escherichia coli.

We examined the possibility that mice could be used in the Sereny test instead of guinea pigs or rabbits. Although the reactions in mice were more transient and not as pronounced as those in guinea pigs, mice indeed could be used to distinguish even macroscopically between virulent and avirulent shigellae. Virulent enteroinvasive Escherichia coli strains were also positive for the mouse Sereny test. We described the macroscopic and microscopic appearance of the mouse eyes. Thus, mice are recommended for use in the Sereny test, particularly when a large number of samples are to be tested.

Animals↗

Effect of erythorbic acid administration on ascorbic acid content in guinea pig tissues.

The effect of erythorbic acid (ErA) on ascorbic acid (AsA) content in the tissues of normal and AsA-deficient guinea pigs was studied. The animals were sacrificed at varying intervals during the experimental period, and the liver, adrenal glands, spleen and kidneys were removed. The amounts of AsA and ErA in the tissues were measured by HPLC. The content of AsA in the tissues of the animals administered both AsA and ErA was lower than that of the animals administered only AsA. But the disappearance rate of AsA from the tissues of the AsA-deficient animals was similar to that of the animals administered only ErA. The amount of AsA in the tissues of the animals administered both AsA and ErA during the repletion period was lower than that of the animals administered only AsA. These results suggest that ErA administration may affect the amount of AsA in the tissues by inhibiting its tissue uptake or its storage in the tissues, and not by accerelating the catabolism of AsA in the tissues.

Adrenal Glands↗

Antiscorbutic effect of dehydro-L-ascorbic acid in vitamin C-deficient guinea pigs.

The antiscorbutic effect of dehydro-L-ascorbic acid (DAsA) was investigated in vitamin C-deficient guinea pigs. Male guinea pigs were fed vitamin C-deficient diets for 16 days to deplete body L-ascorbic acid (AsA) pools and then fed the deficient diet supplemented with DHA and/or AsA intraperitoneally for 14 days. During the repletion period, most of the animals injected with 0.5 mg DAsA/day developed scurvy, their body weights decreased and their mortality rate was higher than that of the other groups injected with 0.5 mg AsA/day or 5 mg DAsA/day. Injecting animals with 0.5 mg AsA/day resulted in the disappearance of the typical scorbutic symptoms and regaining of body weight. These data indicate that DAsA has considerably less antiscorbutic activity than AsA in vitamin C-deficient guinea pigs.

Adrenal Glands↗

The tissue distribution of L-ascorbic acid and dehydro-L-ascorbic acid in the guinea pigs injected intravenously with dehydro-L-ascorbic acid.

The tissue distribution of L-ascorbic acid (AsA) and dehydro-L-ascorbic acid (DAsA) in guinea pigs injected with DAsA intravenously was examined using high-performance liquid chromatography. DAsA injected into guinea pigs fed normal diets containing AsA (control group) was readily taken into erythrocytes, and AsA contents of plasma and other tissues rapidly increased after DAsA injection. In animals fed vitamin C-deficient diets, DAsA was also detected in erythrocytes; however, the increase of AsA in their tissues was considerably less than that of control group. From these results, it was suggested that utilization of DAsA as AsA in vitamin C-deficient guinea pigs was less than that of control animals, and the reduction mechanism of DAsA to AsA in vitamin C-deficient guinea pigs may have differed from that of control groups.

Administration, Oral↗

Effect of graded doses of erythorbic acid on ascorbic acid content of tissues of guinea pigs.

The effect of graded doses of erythorbic acid (ErA) on the content of ascorbic acid (AsA) in the tissues of guinea pigs administered AsA was studied. The guinea pigs were administered 5 mg AsA and 1, 5, 20, and 100 mg ErA; or 1 mg AsA and 1 and 20 mg ErA; or 20 mg AsA and 20 mg ErA for 16 days. The animals were then sacrificed, and the liver, adrenal glands, spleen, and kidneys were removed to determine the contents of AsA and ErA by using HPLC. The content of AsA in the tissues of the animals administered less than 5 mg ErA together with 5 mg AsA was not significantly different from that of the animals administered 5 mg AsA. The administration of 100 mg ErA together with 5 mg AsA caused a decrease in the amount of AsA in the tissues. The content of AsA in the tissues of the animals administered ErA together with 1 mg AsA was not significantly different from that of the animals administered 1 mg AsA. In the case of animals administered an equal amount of both AsA and ErA, the AsA tissue content was consistently much higher than that of ErA. These results indicated that the administration of relatively small amounts of ErA did not appear to reduce the availability of AsA.

Adrenal Glands↗

Demonstration of herpes simplex 1 virus antigen mouse brain after fixation.

The effects of several fixatives and fixation periods on recovery of viral antigen by indirect immunofluorescence (IF) and indirect immunoperoxidase (IP) were examined in mouse brains infected with type-1 herpes simplex virus. In 10% formalin, the sensitivity of antigen detection by IF decreased after one month fixation and viral antigen was barely detectable after fixation for three months. But in 10% buffered formalin antigenicity was not lost after six months. Similar effects were obtained by IP; however, specimens fixed in 10% formalin for three and six months showed positive reactions. Viral antigen was detectable without enzyme digestion in paraffin materials fixed in Bouin's, Carnoy's and Dubosq-Brazil solutions, but when treated with proteolytic enzyme for three hours, antigen could not be detected by either IF or IP. Ten per cent buffered formalin, Bouin's or Dubosq-Brazil solutions are recommended as fixatives for retrospective immunohistochemical and histopathological studies of viral infection in autopsy and biopsy materials.

Animals↗

[Clinical investigation of the therapeutic effects of cefmenoxime in the treatment of infections complicated by hematological diseases].

Therapeutic effects on cefmenoxime hemihydrochloride (CMX, Bestcall), a new synthetic cephem antibiotic, were examined in the treatment of various infections complicated with hematological diseases. The number of patients treated with CMX was 37 including 5 cases of sepsis or suspected sepsis, 14 cases of pneumonia or suspected pneumonia, 5 cases of upper respiratory diseases, 2 cases of urinary tract infections and 11 cases of other infections. All of these infections were complicated with hematological diseases: Acute leukemia, 13 cases; chronic myelocytic leukemia, 1 case; adult T cell leukemia, 3 cases; malignant lymphoma, 8 cases; Hodgkin's disease, 2 cases and myeloma, 3 cases. CMX were administered by a single intravenous injection or by a drip infusion. The dose was between 2 and 6 grams per day. Good to excellent clinical results were obtained in 25 out of 37 cases, total effective rate of 67.6%. No clinical side effects or abnormal laboratory findings attributable to CMX were observed except for light diarrhea in 2 cases. By the clinical investigation, it was demonstrated that CMX was one of safe and effective antibiotics for treating infections in the compromised hosts complicated with hematological diseases.

Acute Disease↗

Distribution of gentamicin by immunofluorescence in the guinea pig inner ear.

We studied the distribution of gentamicin in the inner ear, brain and kidney of the guinea pig following intraperitoneal administration or perfusion of gentamicin through the perilymphatic space. The resulting histopathological changes were examined by immunofluorescence using antigentamicin antiserum. After perfusion of gentamicin through the perilymphatic space, specific fluorescence was found in the cochlea, and was especially prominent in the outer hair cells, basilar membrane and basilar crest. Although no fluorescence was observed in the cochlea following intraperitoneal administration of high doses of gentamicin, type I hair cells in the vestibule were seen to be selectively stained with the antibody. Furthermore, some of the vestibular ganglion cells, Purkinje cells and unidentified nuclei in the brain stem were also stained. In particular, fine granules showing relatively intense fluorescence were recognized in the cytoplasm of the stained cells. In the cortex of kidney, only proximal tubular cells were stained with intense fluorescence. Our results suggest that the aminoglycoside antibiotics have two sites of action: one is the cell membrane of the sensory hair cells and the other is the cytoplasm.

Animals↗

Myocardial lesions by Coxsackie virus B3 and cytomegalovirus infection in infants.

Immunofluorescent and electron-microscopic studies were performed to determine the distribution of viral antigens and particles and to clarify the relationship to myocardial lesions in two autopsy cases with generalized infection of Coxsackie virus B3 (CVB3) or cytomegalovirus (CMV). Case 1 was a full-term newborn female infant, without any congenital anomalies, who died of cardiac failure 10 days after birth. CVB3 was isolated from the blood before death. Necrosis of the muscle fibers was observed, frequently accompanying calcification. Numerous histiocytes and a few lymphocytes and neutrophils had infiltrated in and around the necrotic areas. Immunofluorescent study (IF) revealed CVB3 antigen in the muscle fibers and vascular endothelial cells. Case 2 was a female infant, born at 28 weeks of gestation, who died of fatal arrhythmia 50 days after birth. The infant had hemocephalus and a history of idiopathic respiratory distress and underwent an operation for patent ductus arteriosus. Cytomegalic cells were frequently found in the vascular endothelial cells in the myocardium and occasionally in muscle fibers. IF showed the presence of CMV antigen in both endothelial cells and muscle fibers. CVB3 and CMV antigens were detected predominantly in vascular endothelial cells rather than in the muscle fibers. Blood flow disturbance due to endothelial damage is a cause of the myocardial lesion in addition to the direct invasion of the muscle fibers by the virus.

Antigens, Viral↗

Serological and virological evidence of a Hantaan virus-related enzootic in the United States.

The first isolation of a Hantaan-related virus from a feral rat in the United States was made from a Rattus norvegicus caught in New Orleans. The strain, designated Tchoupitoulas virus, is antigenically related to, but distinct from, the prototype strain 76-118 of Hantaan virus and is the first Hantaan-like virus isolated from the pancreas of a naturally infected animal. Serosurveys of wild rodents from urban and rural areas in the United States indicated that Hantaan-related viruses infected urban rats in coastal and inland cities and infected five species of New World rodents in the western United States (Peromyscus maniculatus, Peromyscus difficilis, Peromyscus californicus, Neotoma mexicana, and Neotoma cinerea). Serosurveys disclosed no evidence of Hantaan-virus infection in rats in large-scale breeding colonies.

Animals↗

An immunofluorescent study of generalized Coxsackie virus B3 infection in a newborn infant.

An autopsy case of a 10-day-old newborn with generalized infection of Coxsackie virus B3 (CBV3) was reported. CBV3 was isolated from the blood before death. The patient died of cardiac failure. An immunofluorescent study was carried out on autopsy specimens fixed in formalin and embedded in paraffin. CBV3 antigen was detected in the heart, brain, kidney, lungs, spleen, thymus, and pancreas. In the pancreas CBV3 antigen was predominantly seen in the islet cells. No CBV3 antigen was found in the liver and adrenal glands. Electron microscopic examination revealed virion-like particles, 20 nm in diameter, in the endothelial cells of the myocardium.

Antigens, Viral↗

Experimental infection in newborn mice and rats by hemorrhagic fever with renal syndrome (HFRS) virus.

Newborn mice and rats were inoculated intracerebrally (ic) or intraperitoneally (ip) with Hantaan virus (76-118 strain) or HFRS-related virus (B-1 strain). The mortality and the influence on the increase of body weight in newborn mice were higher in the groups infected with the 76-118 strain than in the groups infected with the B-1 strain, while the B-1 strain was more virulent in rats than the 76-118 strain. Virus isolation from rats inoculated with either strain was attempted 7 and 11 weeks after inoculation. Virus could be isolated from various organs of rats infected with the B-1 strain, while it was recovered from only the brain and lungs of rats infected with the 76-118 strain. Viral antigen was readily detected in various organs of rats infected with the B-1 strain, but the amount and distribution of antigens were less in rats infected with the 76-118 strain. Our results suggest that the virulence of HFRS-related virus is variable, depending on the species of infected animals as well as on the virus strains. The virus also persists in the injected animals with high titers of antibodies for at least 11 weeks.

Animals↗

An immunofluorescent study of generalized infection of human cytomegalovirus in a patient with systemic lupus erythematosus.

An autopsy case of generalized infection of cytomegalovirus (CMV) in an adult with systemic lupus erythematosus is reported. CMV infection was histologically diagnosed postmortem by the presence of the characteristic cytomegalic cells with inclusion body. In the lungs, viral antigen was seen not only in the cytomegalic cells with inclusion body but also in the cells without intranuclear inclusion body in both of the frozen and the formalin-fixed paraffin sections. Viral antigen was also detected in frozen sections of the liver. CMV was isolated from the lung and liver.

Adult↗

Clinical evaluation of two combination chemotherapies for the treatment of small cell carcinoma of the lung.

The effects of two different combination chemotherapies, i.e. cyclophosphamide (CPM) + vincristine (VCR) + methotrexate (MTX) and ACNU + VCR, with or without radiotherapy, were studied in twenty patients with untreated small cell carcinoma of the lung. Respective response rates were 66.7% for CVM and 50% for AV. Median survival time was 51 weeks for CVM and 27 weeks for AV. There was no statistically significant difference between the survival probability curves of CVM and AV. Concerning toxicity, two hazardous side effects, myelosuppression and interstitial pneumonitis, were observed although the incidences were low. We concluded that both regimens are useful as chemotherapy of small cell carcinoma.

Aged↗