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Biomedical subjects

K Ri

Publications and source records attributed to K Ri.

At least 19 recordsLinked to original sources
PubMed1996

Protective effect of dipyridamole against lethality and lipid peroxidation in liver and spleen of the ddY mouse after whole-body irradiation.

The effects of dipyridamole on radiation damage in the mouse were investigated. Dipyridamole (i.p. 2 mg/mouse) administered 1 h before exposure, protected against gamma-irradiation. Pretreatment significantly decreased the death rate at 30 days from 89 to 33% (p<0.001) after 9 Gy whole-body irradiation. LD50 at 30 days was increased from 6.67 to 7.65 Gy in the dipyridamole pretreated group. The level of thiobarbituric acid reactive substances (TBARS) in the liver and spleen, a measure of free radical initiated liver peroxidation, increased 155, 193, 195, and 236% of control (without irradiation) in liver, and 132, 146, 168, and 276% of control (without irradiation) in spleen on days 2, 4, 7, and 10 after 9 Gy of whole-body irradiation respectively. The TBARS levels in both liver and spleen 2 days after irradiation were reduced to 73 +/- 7 and 60 +/- 19% respectively after dipyridamole treatment (2 mg/mouse, i.p. injection 1 h before exposure). In electron microscopic studies, mitochondria and endoplasmic reticulum in the irradiated mouse liver were swollen, but otherwise appeared normal after dipyridamole treatment. These results suggest that dipyridamole has a protective effect on animal survival 30 days after 60Co gamma-irradiation and inhibits lipid peroxidation - which is thought to play a part in the radiation injury in mouse liver and spleen.

Animals↗
PubMed1996

[Brain CT and MRI findings in fat embolism syndrome].

To elucidate brain CT and MRI findings in fat embolism syndrome (FES), we retrospectively analyzed images from 5 patients with FES during the acute and subacute stages. Brain CT examinations demonstrated brain edema in 2 patients and transient spotty low density lesions in 2 patients. Three patients showed no abnormalities. Brain MRI, however, showed brain abnormalities in all patients during the acute stages. These were revealed as spotty high signal intensity lesions on T2WI, and some showed low intensity on T1WI. These spotty lesions were considered to reflect edematous fluid occurring as a result of the unique pathophysiological condition of FES. While the spotty high signal intensity lesions on T2WI were distributed in the cerebrum, cerebellum, brain stem, thalamus, basal ganglia, internal capsule and corpus callosum, cerebral and cerebellar spotty lesions were characteristically located along the boundary zones of the major vascular territories. This characteristic location might be induced by a hypoxic brain condition in FES because the numerous fat globules present in this condition can block entire brain capillaries. This characteristic signal location on T2WI is a useful indicator for differentiating FES from the primary intra-axial brain injury in patients with multifocal trauma.

Adolescent↗
PubMed1994

[CT findings of sinonasal and orbital Wegener's granulomatosis].

We reviewed the CT findings of four cases of Wegener's granulomatosis that presented as inflammatory masses in the sinonasal cavity or orbit. In the present study, an infiltrative nature and homogeneous texture with contrast enhancement were typical of the masses. In addition, the masses were frequently accompanied by infiltration of the pterygopalatine fossa or destruction of adjacent bone. However, no pathognomonic findings were observed.

Adult↗
PubMed1994

[CT findings of pulmonary inflammatory pseudotumors (plasma cell granulomas)].

Pulmonary inflammatory pseudotumor (plasma cell granuloma) is not a true neoplastic lesion, but is composed of a variety of inflammatory cells, predominantly plasma cells. The chest X-ray features resemble those of malignant lung tumors; therefore, CT is often necessary for further evaluation. We report the CT features of five cases with histologically proved pulmonary inflammatory pseudotumor, which can be summarized as follows: a solitary round or oval parenchymal mass with regular or irregular margin, and with or without calcifications. The calcifications are useful for differential diagnosis if present, but they are usually non-specific in shape and configuration. The mean CT attenuation value of the major portion of the mass was increased from 41 HU to 78 HU by the injection of contrast material. In one case, a linear extension of the lesion was seen from the mass to the lung hilum. In three cases, satellite lung nodules were seen. One of these nodules was also proved histopathologically to be inflammatory pseudotumor. The biopsy specimens obtained by using a 20 gauge cutting-needle and an automated biopsy gun were satisfactory for histopathological diagnosis.

Adult↗
PubMed1994

Bronchioloalveolar adenoma of the lung: CT-pathologic correlation.

PURPOSE: To correlate the appearance of bronchioloalveolar adenoma (BAA) of the lung at computed tomography (CT) with its pathologic features. MATERIALS AND METHODS: Nine small pulmonary nodules with ground-glass attenuation were found at CT in 668 patients with lung carcinoma. Seven of these nine lesions were histopathologically diagnosed as BAA in four patients (three men and one woman, aged 66-77 years) (three lesions in one man, two lesions in the woman, and one lesion each in the remaining two men) and are the subject of this study. RESULTS: BAA of the lung appeared at CT as a small pulmonary nodule with ground-glass attenuation; microscopic examination revealed hyperplasia of the alveolar cuboidal cells on hyperplastic alveolar septa. The CT findings depicted partial reduction of the alveolar air spaces owing to an increase in cellular components within the lesion. Adenocarcinoma cells were also seen within the BAA lesion in one patient. CONCLUSION: In a patient with known lung carcinoma, a small nodule with ground-glass attenuation simulating a focal lesion of pulmonary interstitial disease must be investigated to rule out BAA or multicentric adenocarcinoma.

Adenocarcinoma, Bronchiolo-Alveolar↗
PubMed1993

[CT and MR imaging of desmoid tumors--comparison of two modalities].

As desmoid tumors invade locally and postoperative recurrence is common, accurate diagnosis of the extent of the tumor is needed prior to surgery. CT and/or MRI evaluation of tumor extension was retrospectively studied in eight patients with desmoid tumors, and the results were correlated with the histopathological findings. All tumors were completely resected even in patients who were evaluated by CT alone. However, the delineation of tumor and local invasion were not clearly demonstrated by CT. On the other hand, the delineation of tumor and local invasion were well visualized on MRI. The MRI picture of desmoid tumors was mainly composed of two different areas of signal intensity. The area of hypointensity in both T 1- and T 2-weighted images was found to have abundant collagen fibers, while the area of isointensity or slight hyperintensity in T 1-weighted images and hyperintensity in T 2-weighted images was found to have fibroblasts. In conclusion, MRI is better suited to the evaluation of patients with desmoid tumors than CT.

Adolescent↗
PubMed1992

[CT features of chronic maxillary osteomyelitis in adults].

CT findings were reviewed in four adult patients with chronic maxillary osteomyelitis (CMO) that was histologically proved. The CT features of CMO included bone destruction and soft tissue mass, predominantly in the inferior portion of the maxillary antrum (all 4 cases), thickening of the antral wall (3 cases) and abnormal soft tissue around the antrum associated with or without bony wall destruction (3 cases). CMO could not be distinguished from cancer of the maxillary antrum on CT because of the similar findings. However, abnormal soft tissue around the antrum together with an undestructed bony antral wall may be useful for differentiating the two diseases.

Adult↗
PubMed1992

[CT findings of mucin-producing pancreatic cancer--differentiation from chronic pancreatitis].

Mucin-producing pancreatic cancers (MPPC), which include mucinous adenocarcinoma, papillary adenocarcinoma and cystadenocarcinoma, are radiographically characterized by diffuse or localized dilatation of the main pancreatic duct due to excessive mucin production. Therefore, MPPC are occasionally difficult to distinguish from chronic pancreatitis on CT unless the primary pancreatic lesion is visualized. We compared five cases of MPPC with five cases of chronic pancreatitis with marked duct dilatation to determine differences in CT images between the two diseases. There was no significant difference between the two diseases in the nature of duct dilatation (size, extent, contour) or parenchymal changes (atrophy, enlargement, calcification, cystic lesion). However, dilatation of the intramural duct was characteristically observed in MPPC but not in chronic pancreatitis. Papillary masses in the pancreatic duct, when observed, were another finding specific to MPPC.

Aged↗
PubMed1992

[CT-guided percutaneous lung biopsy using a cutting needle and an automated biopsy gun. Comparison with lung biopsy using a manual aspiration needle].

Twenty-five percutaneous lung biopsies using a 20-gauge cutting needle and automated biopsy gun (ABG) were performed under CT guidance in 25 patients with thoracic lesions. This procedure was compared with that using a 21-gauge manual aspiration needle in 36 patients (40 examinations, 37 lesions) in terms of success rate, rate of correct diagnosis, mean examination time and rate of complications. Specimens obtained from lung biopsy were graded by a histopathologist according to quality and quantity from 0 to 4 (pathological score). There were no statistically significant differences between the two procedures in terms of success rate, rate of correct diagnosis and rate of complications; only the time required was significantly different. However, sufficient biopsy material and a mean pathological score of G-II 2.8 (that of G-I was 1.9, p less than 0.05) could be obtained by the biopsy procedure using the cutting needle. The above results indicated that aspiration needle biopsy was adequate for lung biopsy, but that a cutting needle and ABG should be used when a good biopsy specimen is needed for tissue diagnosis.

Adolescent↗
PubMed1987

[Study on insulin resistance in rats treated with estrogen and progesterone--assessment with the euglycemic glucose clamp technic].

To clarify the mechanism of insulin resistance in pregnancy, we have used the euglycemic glucose clamp technique in estradiol(E) treatment(n = 6), progesterone(P) treatment (n = 28), and Control(n = 29) female rats. E(10 micrograms/day) and P(10 mg/day) were injected subcutaneously into female rats for 14 days, to increase E and P concentrations to pregnant levels. Glucose production and glucose utilization were measured by using [3-3H]-glucose. The results were as follows, 1) Glucose production was almost suppressed at hyperinsulinemia(11,000 microU/ml) both Control and P treatment rats. Then at hyperinsulinemia, glucose utilization rate was almost equal to glucose infusion rate. 2) In P treatment rats glucose utilization was significantly lower (p less than 0.05) than in Control rats at hyperinsulinemia (11,000 microU/ml). 3) In P treatment rats glucose infusion rate was significantly lower than in Control rats at plasma insulin concentrations of 1,000 microU/ml(p less than 0.02), and 11,000 microU/ml(p less than 0.01), and lower than in E treatment rats at plasma insulin concentrations of 11,000 microU/ml(p less than 0.05). 4) In a dose-response curve for the effects of four different concentrations of insulin on glucose infusion rate, the insulin resistance induced by progesterone is characterized by a decreased responsiveness to insulin. The results suggest that progesterone may play an important role in inducing insulin resistance in pregnancy.

Animals↗
PubMed1984

[Prevention of postoperative infection following cardiac catheterization in pediatric field. Study of air-borne bacteria in X-ray room and evaluation of an antibiotic used for prevention of postoperative infection].

As part of preventive measures against postoperative infection following cardiac catheterization in infants with cardiac diseases, especially falling bacteria in X-ray room was studied. Moreover, a synthetic penicillin, ticarcillin (TIPC), was used as preventive antibiotic against postoperative infections due to falling bacteria which probably contaminate the air in the X-ray examination room, and the efficacy and side effects of the drug were observed. As result, coagulase-negative Staphylococcus was detected the most, followed by Micrococcus and then by fungus. The number of these 3 organisms corresponded to 90.3% of the total number of falling bacteria detected during operation. The number of falling bacteria during operation was 5.1 times larger than that before operation. Taking into account normal flora of skin, falling bacteria present in the X-ray room and causative organisms of bacterial endocarditis, TIPC was administered to 30 cases intravenously 5 times at a dose of 30 mg/kg every 8 hours for the purpose of preventing possible postoperative infections following cardiac catheterization. The drug was effective to prevent such infections in all cases. No side effects were noted in any case, in peripheral blood and hepatic function tests and other observations.

Adolescent↗