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Biomedical subjects

E Cho

Publications and source records attributed to E Cho.

At least 55 records · Page 3Linked to original sources
PubMed1996

High-fat diet induces aggressive behavior in male mice and rats.

The present study investigated whether dietary fat increases aggressive behavior in male mice and rats. High fat consumption may elevate circulating estrogen levels and estrogens, in turn, are associated with various non-reproductive behaviors, such as male aggression. The animals were assigned to two groups including those consuming a diet high in polyunsaturated fats (43% calories from fat) and those consuming a low-fat diet (16% calories from fat). Each male animal was housed with two females for three weeks. The male mice and rats were then confronted with an intruder kept on a medium-fat feed. The latency to first aggressive encounter was significantly shorter among the male animals kept on a high-fat diet than those males kept on a low-fat diet. Furthermore, the time spent exhibiting aggression was longer in the high-fat groups. Serum levels of estradiol (E2) were elevated by 2-fold in the male animals consuming a high-fat diet, when compared with the male animals kept on a low-fat diet. These findings suggest that dietary fat can increase aggressive behavior in male mice and rats, possibly by elevating circulating E2 levels.

Aggression↗
PubMed1996

Immunohistochemical studies of GABA and parvalbumin in the developing human cerebellum.

The localization of GABA and parvalbumin was studied in the developing cerebellum of human fetuses from 16 to 28 weeks of gestation. The avidin-biotin complex immunohistochemical method combined with silver staining were used to reveal the presence of GABA- and parvalbumin-positive neurons and nerve fibres. As early as the 16th week of gestation, GABA immunopositivity was observed in the cerebellar cortex and the deep nuclei. GABA-positive neurons included Purkinje cells, stellate and basket cells of the cerebellar cortex and neurons in the deep nuclei. The gradient of immunoreactivity increased with the maturing cells, being weak at 16 weeks and becoming markedly pronounced at 28 weeks of gestation. GABA-immunopositive mossy fibres were observed in the granular cell layer at 16 weeks, and by 28 weeks, a robust fibre network was present in the cortex and deep nuclei. Immunohistochemical localization for parvalbumin indicates that weak immunoreactivity was observed in Purkinje cells, stellate and basket cells at 16 weeks of gestation, increasing in intensity with advancing age, notably in the Purkinje cells which had acquired an elaborate arbor of neurites at 28 weeks of gestation. In the deep nuclei, parvalbumin-positive cells and nerve fibres were observed throughout the 16 to 28 week period. These results indicate that GABA- and parvalbumin-positive neurons and fibres appeared as early as 16 weeks of gestation, expressing a high degree of immunoreactivity by the 28 week of fetal age.

Cerebellum↗
PubMed1996

Reduced in vivo plasma fibronectin content of lung matrix during postoperative sepsis.

Sepsis after surgery, trauma, or burn contributes to altered lung endothelial permeability and respiratory failure. Fibronectin (Fn), an opsonic and adhesive glycoprotein, exists in both a soluble form in plasma and an insoluble form in the extracellular matrix (ECM). Recent studies [E. M. Wheatley, P. J. McKeown-Longo, P. A. Vincent, and T. M. Saba, Am. J. Physiol. 265 (Lung Cell. Mol. Physiol. 9): L148-L157, 1993] suggest that the ECM content of Fn may influence lung vascular permeability. We evaluated the incorporation of plasma-derived Fn (pFn) into the ECM of the lung during postoperative sepsis. Postoperative nonseptic and postoperative septic rats were compared, using a model of laparotomy followed by cecal ligation and puncture. To label the pFn pool, rats received intravenously 3 micrograms of purified rat 125I-labeled Fn/100 g body weight 6 h after surgery (laparotomy). 125I-Fn in the deoxycholate detergent-insoluble fraction of tissues was used to quantify matrix-incorporated Fn at 4 h after infusion with 125I-Fn. Septic rats exhibited a peripheral leukopenia as well as reduction in plasma volume, Fn halflife, and total pFn pool. Incorporation of pFn in the liver and spleen of postsurgical septic rats was not different (P > 0.05) from sham-operated (postsurgical nonseptic) rats, but incorporation was significantly decreased (P < 0.05) in vivo in the lung. However, under controlled in vitro conditions, lung tissue harvested from septic or sham-operated rats demonstrated a similar tissue incorporation of soluble 125I-pFn as well as similar rates of retention/turnover of ECM 125I-Fn, based on pulse-chase experiments. These data suggest that the in vivo inflammatory environment in the lung during postoperative sepsis, which cannot be reproduced in vitro, may alter the Fn content of the ECM of the lung. Such reduced levels of pFn in the lung ECM may be a factor influencing lung vascular integrity during postoperative sepsis.

Animals↗
PubMed1996

Metabolic changes of acetaminophen after intravenous administration to rats pretreated with a hepatoprotective agent, YH-439.

The metabolic changes of acetaminophen (AAP) were investigated after the intravenous (iv) administration of AAP, 300 mg per kg body weight, to the control rats (n = 7) and rats pretreated with a new hepatoprotective agent, YH-439 (200 mg per kg body weight, orally administered for 3 consecutive days, n = 7). After iv administration of AAP, the AUC of AAP was significantly smaller and both the CL and CLNR of AAP were significantly faster in the YH-439 treated rats. The CLR of AAP-glucuronide and the partial clearance of both AAP-glucuronide and AAP-sulfate were significantly faster in the YH-439 pretreated rats. The percentages of iv dose excreted in 6 hr bile as AAP-glucuronide, AAP-glutathione, and AAP-cysteine-expressed in terms of AAP-significantly increased in the YH-439 pretreated rats. The above data suggest that the metabolism of AAP increases by pretreatment with YH-439, and the mechanism for the hepatoprotective effect of YH-439 appears to be due, at least in part, to the increased detoxification by the enhanced glucuronidation, and cysteine and glutathione conjugation of AAP.

Acetaminophen↗
PubMed1995

Shades of gray matter: noninvasive optical images of human brain responses during visual stimulation.

Recent theories about human brain function emphasize the need for imaging methods that allow the study of dynamic interactions among different structures. In this paper, we report on a new technique, based on the measurement of parameters of migration of near-infrared photons, that yields functional images of the human occipital cortex, combining a spatial resolution of 0.5 cm and a temporal resolution of 50 ms. This technique appears to be suitable for studying the dynamics of cortical activation.

Adult↗
PubMed1995

Extracellular matrix incorporation of normal and NEM-alkylated fibronectin: liver and spleen deposition.

The incorporation of plasma fibronectin (pFn) into the extracellular matrix (ECM) is believed to influence tissue integrity, wound repair, and vascular permeability. In vitro, matrix assembly of Fn requires the binding of soluble Fn to cell-associated matrix assembly sites. Alkylation of human pFn (HFn) with N-ethylmaleimide (NEM) prevents the initial binding of Fn to matrix assembly sites as well as its in vitro incorporation into the ECM as reflected by detergent-insoluble 125I-labeled Fn (pool II Fn). We determined the kinetics of Fn matrix incorporation in tissue and whether NEM treatment of rat pFn (NEM-RFn) would limit its in vivo incorporation into ECM by analysis of pool I [deoxycholate (DOC) soluble] and pool II (DOC insoluble) 125I-Fn in tissues after its intravenous injection into rats. After intravenous injection, tissue incorporation of normal rat 125I-pFn was especially intense in liver and spleen, in agreement with the large amount of endogenous Fn detected in the matrices of these organs. Tissue deposition of plasma-derived 125I-RFn in liver and spleen peaked by 4 h, with significant (P < 0.01) loss over 24 h, indicating turnover of matrix Fn. Tissue localization of normal 125I-RFn in liver, lung, spleen, heart, and intestine was greater (P < 0.05) than 125I-NEM-RFn at 4 h. Normal HFn, but not NEM-HFn, was incorporated into tissues and colocalized with endogenous Fn in the matrix. To identify the cells mediating the intense incorporation of pFn into liver ECM, we compared matrix assembly of 125I-HFn by cultured fibroblasts, hepatocytes, and hepatic Kupffer cells. With fibroblasts, 125I-HFn in pool I reached steady state by 3 h, whereas 125I-HFn in pool II exceeded that in pool I by 6 h and continued to increase over 24 h. With hepatocytes, pool I 125I-HFn reached steady state by 1 h, and a progressive increase (P < 0.05) of 125I-HFn in pool II was observed over 24 h. Kupffer cells were not able to incorporate significant amounts of 125I-HFn into matrix. NEM-HFn displayed limited incorporation into ECM by both fibroblast and hepatocyte cultures. These novel observations suggest that the interaction of soluble pFn with matrix assembly sites is necessary to its in vivo incorporation into the ECM.

Alkylation↗
PubMed1995

Moisture susceptibility of resin-modified glass-ionomer materials.

The purposes of this experiment were to determine if resin-modified glass-ionomer cements are less sensitive to moisture than are conventional glass-ionomer cements, to investigate the effects of barrier coatings, and to study the effects of different setting environments. Discoid specimens of a variety of resin-modified glass-ionomer materials and a conventional glass-ionomer cement control were stored in different environments and were protected with different barrier coatings. The diametral tensile strengths of the specimens were determined and analyzed with three-way analysis of variance. Resin-modified glass-ionomer cements are less sensitive to moisture than is the conventional glass-ionomer cement control. Drier environments produced stronger resin-modified glass-ionomer specimens. Use of a fissure sealant as a barrier coating increased overall specimen strength, and the individual materials differed in strength.

Absorption↗
PubMed1995

[Management of polypoid lesions of the gallbladder by endoscopic ultrasonography (EUS)--a retrospective study to establish the diagnostic criteria and a prospective study to evaluate its reliability].

The diagnostic criteria of endoscopic ultrasonography (EUS) in the management of polypoid lesions of the gallbladder was established by a retrospective study using 57 cases with polypoid lesions of the gallbladder that were all resected and confirmed histologically. By this study, EUS findings of polypoid lesions of the gallbladder were classified into the following six groups; Type I with a foamy high echogram, Type II with a globular high echogram, Type III with a papillary high echogram, Type IV with a papillary solid echogram, Type V with a nodular solid echogram and Type VI with a nodular solid echogram including multiple spotty an-echoic areas which suggested the presence of Rokitansky-Aschoff sinus. Comparing the types of EUS findings with histological diagnosis, Type I and II corresponded to cholesterol polyps. Type III and IV contained benign pseudo tumors such as cholesterol polyp or hyperplastic polyp as well as tumorous lesions such as adenocarcinoma or adenoma. Type III with over 10 mm in size and IV with over 5 mm in size had a possibility of tumorous lesions. Type V usually corresponded to adenocarcinoma, and Type VI to adenomyomatous hyperplasia. From these results, the following criteria was established; (1) Polypoid lesions showing Type I, II, III with less than 10 mm in size, IV with less than 5 mm in size and VI should be followed-up as benign diseases. (2) Polypoid lesions of Type III with over 10 mm in size and IV with over 5 mm in size was considered to be relative indications for surgery as tumors. (3) Polypoid lesions of Type V was an absolute surgical indication as malignant. The reliability of this EUS criteria was followingly evaluated by a prospective study using 94 cases with polypoid lesions of the gallbladder; 32 cases with open or laparoscopic cholecystectomy and 62 cases with over one year follow-up observations. The criteria corresponded well with the histological or follow-up findings in Type I, II, III with less than 10 mm in size, IV with less than 5 mm in size, V and VI. It had, however, a tendency of over indications to surgery in Type III with over 10 mm in size and IV with over 5 mm in size because these types were widely set not to overlook tumorous lesions such as adenoma and small adenocarcinoma.(ABSTRACT TRUNCATED AT 400 WORDS)

Endoscopy, Digestive System↗
PubMed1993

Hepatic removal of 125I-DLT gelatin after burn injury: a model of soluble collagenous debris that interacts with plasma fibronectin.

The decline of plasma fibronectin after surgery, trauma, and burn, as well as during severe sepsis after injury, appears to limit hepatic Kupffer cell phagocytic activity. Intravenous infusion of gelatin-coated particles to simulate blood-borne particulate collagenous tissue debris in the circulation after injury also depletes plasma fibronectin. We used soluble gelatin conjugated with 125I-labeled dilactitol tyramine (DLT-gelatin) as a model of soluble collagenous tissue debris. We studied its blood clearance as well as organ localization in normal and postburn rats. Fibronectin-deficient plasma harvested early after burn exhibited limited ability to support in vitro phagocytic uptake of the gelatinized microparticles by Kupffer cells in liver tissue from normal rats. However, Kupffer cells in liver tissue from normal and postburn rats phagocytized the test particles at a normal rate when incubated in normal plasma. The DLT-gelatin ligand bound to fibronectin in a dose-dependent manner as verified by its capture with anti-fibronectin coated plastic wells when coincubated with purified fibronectin. By gel filtration chromatography, the binding of fibronectin with the DLT-gelatin ligand was readily detected, resulting in the formation of a high-molecular-weight complex. In normal animals the plasma clearance and liver localization of 125I-DLT-gelatin was competitively inhibited by infusion of excess nonradioactive gelatin. The blood clearance and liver localization of the soluble gelatin ligand were also impaired after burn injury during periods of fibronectin deficiency similarly to the pattern observed with gelatin-coated microparticles. By autoradiography, the cellular site for the uptake of the 125I-DLT-gelatin was primarily but not exclusively hepatic Kupffer cells; 125I-DLT-asialofetuin and 125I-DLT-ovalbumin were removed by hepatocytes and sinusoidal endothelial cells, respectively. Thus, gelatin conjugated with 125I-DLT can be used to simulate blood-borne soluble collagenous tissue debris after burn. It rapidly binds to plasma fibronectin before its hepatic Kupffer cell removal, and its blood clearance is markedly delayed after burn injury during periods of plasma fibronectin deficiency.

Animals↗
PubMed1993

Automated blood pressure measurements in laboring women: are they reliable?

OBJECTIVE: In laboring women a consistent difference has become evident between measurements obtained with an automated blood pressure device and those obtained with the auscultatory method. A prospective study was designed to assess the concordance of these two methods. STUDY DESIGN: Three sets of brachial blood pressure measurements were made by both oscillatory and auscultatory techniques in 30 women in labor, 20 term pregnant women not in labor, and 20 nonpregnant volunteers. RESULTS: In the nonlaboring women and the nonpregnant controls there was satisfactory agreement between the results of the two methods of measurement. In the parturients systolic pressures were consistently and significantly higher and diastolic pressures consistently and significantly lower with the oscillatory compared with the auscultatory method, but mean arterial pressures were not different. CONCLUSION: In laboring women there is a discrepancy between systolic and diastolic pressures obtained by the auscultatory versus the oscillatory method of measurement, although mean pressures are not significantly different. We suggest that during labor the diagnoses of hypertension and hypotension be based on the mean rather than the systolic or diastolic pressure.

Auscultation↗
PubMed1993

[Endoscopic sphincterotomy for lithotripsy (EST-L) of bile duct stones].

We performed EST-L for 555 patients with choledocholithiasis between 1981 and 1992. With the aid of conventional occlusion balloons and dormia-type baskets, calculi < or = 1.5 cm was extracted with relative ease. In patients with larger stone (> 1.5 cm), the mechanical lithotripter, extracorporeal shock wave lithotripsy (ESWL) and electrohydrolic lithotripsy were used for the lithotripsy. The overall success rate was 95%. Important early and late complications from these procedures occurred in 6.9% and 9.1% of all cases respectively. This result reveal that EST-L is safe and effective therapeutic procedures for choledocholithiasis. We would recommend EST-L is adopted as an initial measure to remove common bile duct stones.

Bile Duct Diseases↗