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Biomedical subjects

T Ebihara

Publications and source records attributed to T Ebihara.

At least 19 recordsLinked to original sources

Rewarming following accidental hypothermia in patients with acute subdural hematoma: case report.

A 57-year-old man was admitted to the Emergency and Critical Care Department with accidental hypothermia (31.5 degrees C) after resuscitation from cardiopulmonary arrest (CPA). Brain CT revealed an acute subdural hematoma. Active core rewarming to 33 degrees C was performed using an intravenous infusion of warm crystalloid. The patient underwent craniotomy soon after admission, with bladder temperature maintained at 33 to 34 degrees C throughout the surgery. Therapeutic hypothermia (34 degrees C) was continued for 2 days, followed by gradual rewarming. After rehabilitation, the patient was able to continue daily life with assistance. Traumatic brain injury (TBI) following CPA is associated with extremely unfavorable outcomes. Very few patients with acute subdural hematomas presenting with accidental hypothermia and CPA have been reported to recover. No suitable strategies have been clearly established for the rewarming performed following accidental hypothermia in patients with TBI. Our experience with this patient suggests that therapeutic hypothermia might improve the outcome in some patients with severe brain injury. It also appears that the method used for rewarming might play an important role in the therapy for TBI with accidental hypothermia.

Hematoma, Subdural, Acute↗

Clinical characteristics of postoperative contralateral intracranial hematoma after traumatic brain injury.

OBJECTIVES: To investigate the clinical characteristics of contralateral intracranial hematoma (ICH) after traumatic brain injury. METHODS: The subjects included 149 patients with traumatic ICH treated by hematoma evacuation. The patients were retrospectively divided into a bilateral ICH (B-ICH) group and unilateral ICH (U-ICH) group after craniotomy using brain CT scans for comparison of the following parameters: complicated expanded brain bulk from the cranial window, hypotension during craniotomy, and outcome. RESULTS: Post-craniotomy brain CT scans revealed U-ICH in 106 patients and B-ICH in 43 patients. Average Glasgow Coma Scale on arrival did not differ between the groups, but a higher proportion of patients in the B-ICH group deteriorated after admission (p = 0.02). The B-ICH patients also exhibited a significantly higher rate of expanded brain bulk from the cranial window (p < 0.05). No significant difference was observed between the groups with hypotension during craniotomy. The B-ICH group exhibited a lower rate of favorable outcome (p < 0.05) and higher mortality (p < 0.05). CONCLUSION: The B-ICH patients had a worse outcome than the U-ICH patients. Contralateral ICH was difficult to forecast based on pre- and intraoperative clinical conditions. Subdural hematoma or contusional ICH was frequently observed as a contralateral ICH.

Adolescent↗

Changes in coagulative and fibrinolytic activities in patients with intracranial hemorrhage.

OBJECTIVE: To investigate whether any changes occur in the coagulative/fibrinolytic cascade in patients with subarachnoid hemorrhage (SAH) or hypertensive intracerebral hemorrhage (HICH). DESIGN AND METHODS: Subjects included 143 patients with intracranial hemorrhage (SAH, n = 50; HICH, n = 82; ROSC-SAH [return of spontaneous circulation after cardiopulmonary arrest due to SAH], n = 11). Coagulative and fibrinolytic factors were measured in blood samples taken on admission. RESULTS: The prothrombin fragment 1+2 level was significantly higher (p < 0.005) in SAH patients than in HICH patients. The fibrinolytic factors (plasmin alpha 2-plasmin inhibitor complex, D-dimer, or fibrinogen degradation products) in SAH and ROSC-SAH were both significantly higher than those in HICH, but the significance of difference was stronger in the case of ROSC-SAH (p < 0.05). DISCUSSION: Both coagulative and fibrinolytic activities were altered after the onset of SAH. These results demonstrate that the coagulative/fibrinolytic cascade might be activated via different mechanisms in different types of stroke. It remains unclear, however, whether a significant alteration of the fibrinolytic cascade in patients with ROSC-SAH might be a nonspecific phenomenon attributable to the reperfusion after collapse.

Blood Coagulation↗

Brain oxygen metabolism may relate to the temperature gradient between the jugular vein and pulmonary artery after cardiopulmonary resuscitation.

OBJECTIVE: A gradient between the jugular vein temperature and core body temperature has been reported in animal and clinical studies; however, the pathophysiological meaning of this phenomenon remains unclear. This study was conducted to identify the temperature gradient between the jugular vein and pulmonary artery in comatose patients after cardiopulmonary resuscitation. MATERIALS AND METHODS: The temperatures of the jugular vein and pulmonary artery were measured in 19 patients at 6 and 24 hours after cardiopulmonary resuscitation. Jugular venous blood saturation (SjO2; %) was also measured concomitantly. The patients were divided into 2 groups: high SjO2 (SjO2 > 75%: H-group; n = 10) and normal SjO2 (SjO2 < or = 75%: N-group; n = 9). The temperature gradient was calculated by subtracting the temperature of the pulmonary artery from that of the jugular vein (jugular - pulmonary = dT degrees C). Statistical significance was defined as p < 0.05. RESULTS: dT was significantly lower in the H-group than in the N-group at 6 hours (0.120 +/- 0.011: mean +/- SD vs. 0.389 +/- 0.036: p = 0.0012) and 24 hours (0.090 +/- 0.005 vs. 0.256 +/- 0.030: p = 0.0136) after cardiopulmonary resuscitation. CONCLUSION: The temperature gradient between the jugular vein and pulmonary artery was significantly lower in patients with high SjO2 after cardiopulmonary resuscitation. This temperature gradient may be reflected in brain oxygen metabolism.

Body Temperature↗

Acceleration of chemokine production from endothelial cells in response to lipopolysaccharide in hyperglycemic condition.

UNLABELLED: Chronic hyperglycemia is an established risk factor for endothelial damage. It remains unclear, however, whether brief hyperglycemic episodes after acute stress alter the function of vascular endothelial cells in response to endotoxin. We hypothesize that brief hyperglycemic episodes enhance the production of interleukin-8 (IL-8) after lipopolysaccharide (LPS) stimulation. METHODS: Human umbilical vein endothelial cells (HUVECs; 1 x 10(5) cells/mL, cells from subcultures 2-5, n = 6) were cultivated in various concentrations of glucose (200, 300, 400, and 500 mg/dL) with or without LPS stimulation (1 microg/mL) for 24 hours. After culture, IL-8 levels in the supernatant were measured using ELISA. RESULTS: HUVECs cultured at glucose concentrations of 300 and 400 mg/dL produced more (p < 0.01) IL-8 than control cells (200 mg/dL). HUVECs cultured at glucose concentrations of 300 and 400 mg/dL also produced more (p < 0.01) IL-8 than those cultured in the absence of LPS. CONCLUSIONS: Hyperglycemic conditions enhance IL-8 production by vascular endothelial cells, and this response is augmented by LPS. Infections may foster neutrophil accumulation at injury sites. These results suggest that it is important to manage even short-term increases in blood glucose after acute stress.

Cells, Cultured↗

Importance of cerebral perfusion pressure management using cerebrospinal drainage in severe traumatic brain injury.

OBJECTIVE: To evaluate hemodynamics in patients with severe traumatic brain injury (TBI) after cerebral perfusion pressure (CPP) management using cerebrospinal fluid (CSF) drainage. METHODS: Twenty-six patients with TBI (Glasgow Coma Score = 8 or less) were investigated. Mean arterial blood pressure, CPP, cardiac index (CI), systemic vascular resistance index (SVRI), and central venous pressure were measured. The patients were divided into 2 groups after craniotomy: the intraparenchymal ICP (IP-ICP) monitoring group (n = 14) and ventricular ICP (V-ICP) monitoring group (n = 12). Patient hemodynamics were investigated on the second hospital day to identify differences. Measurements indicated a target CPP above 70 mmHg and a central venous pressure of 8 10 mmHg in both groups. Mannitol administration (IP-ICP group) or CSF drainage (V-ICP group) was performed whenever the CPP remained below 70 mmHg. RESULTS: High SVRI and low CI (p < 0.05) were observed in the IP-ICP group. The V-ICP group exhibited a reduction in the total fluid infusion volume of crystalloid (p < 0.01) and a reduction in the frequency of hypotensive episodes after the mannitol infusion. CONCLUSIONS: CPP management using CSF drainage decreases the total infusion volume of crystalloid and may reduce the risk of aggravated brain edema after excess fluid resuscitation.

Blood Flow Velocity↗

Evolution of spin and field dependences of the effective mass with pressure in CeIn(3).

We have studied the field and spin dependences of the effective masses in CeIn3 as a function of pressure via the de Haas-van Alphen (dHvA) effect. The effective mass increases with the field at pressures up to about 10 kbar and then decreases with the field. The spin direction of the dominant dHvA oscillation is likely to be reversed across the same pressure. The dHvA frequency changes significantly at the pressure P(c) for the antiferromagnetic quantum critical point and two neighboring pressures P2 and P4 below and above P(c). The spin and field dependences rapidly diminish across P(c) and finally disappear above P4. These observations are discussed in conjunction with relevant observations and theories.

Journal Article↗

Dependence of the effective masses in YbAl3 on magnetic field and disorder.

The susceptibility and specific heat--and hence the effective mass--of the intermediate valence compound YbAl3 show anomalous enhancement below the Fermi liquid temperature T(coh) approximately 40 K. We show that these anomalies are suppressed by alloying in Yb1-xLuxAl3 indicating high sensitivity to lattice coherence. The de Haas-van Alphen effective masses for key branches of the Fermi surface are reduced by magnetic fields B>40 T. We argue that this reduction does not arise from 4f polarization but reflects renormalization of the quasiparticle states by the field.

Journal Article↗

Two energy scales and slow crossover in YbAl3.

Experimental results for the susceptibility, magnetization, specific heat, 4f occupation number, Hall effect, and magnetoresistance for single crystals of the intermediate valence (IV) compound YbAl3 show that, in addition to the Kondo temperature scale T(K) approximately 670 K, there is a low temperature scale T(coh) approximately 30-40 K for the onset of Fermi liquid coherence. Furthermore, the crossover from the low temperature Fermi liquid regime to the high temperature local moment regime is slower than predicted by the Anderson impurity model. We suggest that these effects are generic for IV compounds and we discuss them in terms of the theory of the Anderson lattice.

Journal Article↗

Inhibition by docosahexaenoic acid of receptor-mediated Ca(2+) influx in rat vascular smooth muscle cells stimulated with 5-hydroxytryptamine.

The effect of docosahexaenoic acid treatment on intracellular Ca(2+) dynamics in rat vascular smooth muscle cells stimulated with 5-hydroxytryptamine (5-HT) has been investigated in order to elucidate one of the mechanisms for its beneficial effect on cardiovascular disorders. The treatment of cells with 30 microM docosahexaenoic acid for 2 days inhibited an increase in intracellular Ca(2+) concentration induced by 5-HT (10 microM) and a depolarizing concentration of KCl (80 mM). Docosahexaenoic acid treatment significantly inhibited divalent cation influx stimulated by 5-HT and KCl, as measured by Mn(2+) quenching method, whereas had no effect on 5-HT-induced Ca(2+) release from the internal stores. Docosahexaenoic acid treatment also significantly inhibited 5-HT receptor-mediated Ca(2+) influx through Ni(2+)-insensitive channels that were distinct from store-operated channels. These results suggest that the specific inhibition of intracellular Ca(2+) dynamics in vascular smooth muscle cells may contribute to the beneficial properties of docosahexaenoic acid on cardiovascular disorders.

Animals↗

Possible involvement of aminotelopeptide in self-assembly and thermal stability of collagen I as revealed by its removal with proteases.

The functions of aminotelopeptide and N-terminal cross-linking of collagen I were examined. Acetic acid-soluble collagen I (ASC) was purified from neonatal bovine skin and treated with three kinds of proteases. The amino acid sequencing analysis of the N terminus showed that ASC contained a full-length aminotelopeptide. Pepsin and papain cleaved the aminotelopeptide of the alpha1 chain at the same site and the aminotelopeptide of the alpha2 chain at different sites. Proctase-treated ASC lost the whole aminotelopeptide, and the N-terminal sequence began from the tenth residue inside the triple helical region. The rates of fibril formation of pepsin-treated ASC and proctase-treated ASC were the same and were slower than that of ASC. The denaturation temperatures, monitored by CD ellipticity at 221 nm, of ASC, pepsin-treated, or papain-treated collagens were the same at 41.8 degrees C. Proctase-treated ASC showed a lower denaturation temperature of 39.9 degrees C. We also observed the morphology of the collagen fibrils under an electron microscope. The ASC fibrils were straight and thin, whereas the fibrils of pepsin-treated ASC were slightly twisted, and the fibrils from papain- and proctase-treated ASC were highly twisted and thick. When the collagen gel strength was examined by a modified method of viscosity-measurement, ASC was the strongest, followed by pepsin-treated ASC, and papain- and proctase-treated ASCs were the weakest. These results suggest that the aminotelopeptide plays important roles in fibril formation and thermal stability. In addition, the functions of intermolecular cross-linking in aminotelopeptides may contribute to the formation of fibrils in the correct staggered pattern and to strengthening the collagen gel.

Acetic Acid↗

Abalone collagens: immunological properties and seasonal changes of their mRNA levels.

The antisera were raised against pepsin-solubilized abalone collagen and its corresponding gelatin. The reactivity against abalone collagen was higher with the anti-collagen than anti-gelatin antiserum. The two antisera recognized all type I collagens from various vertebrates, whereas these had no reactivity against vertebrate type III and type V collagens. Furthermore, both antisera reacted with only alpha 2(I) chains from chicken, rat, and calf. The strong reactivity was observed against the two antisera in the case of invertebrate and protochordate collagens, especially for turban shell collagen. The seasonal changes of collagen mRNA levels were examined in relation to those of collagen content. Haliotis discus collagens (Hdcols) 1 alpha and 2 alpha coding for abalone collagen pro alpha-chains showed quite similar patterns. The highest mRNA levels in adductor and foot muscles for the two collagens were observed in December and January, in good agreement with the increase of collagen content. The mRNA levels decreased in July and August when collagen content decreased. These results indicate that collagen transcription levels are closely related to collagen contents.

Animals↗

Epidemiological study of human herpesvirus-6 and human herpesvirus-7 in pityriasis rosea.

BACKGROUND: Pityriasis rosea (PR) is a common papulosquamous skin disorder that is suspected to have an infectious aetiology. OBJECTIVES: We aimed to study the role of human herpesvirus (HHV)-7 and HHV-6 in the pathogenesis of PR. METHODS: We performed seroepidemiological studies (indirect immunofluorescence test) and polymerase chain reaction (PCR) analysis for HHV-6 and HHV-7 in patients with PR. Seventy-two serum samples and 37 samples of peripheral blood mononuclear cells (PBMC) from 44 patients with PR were obtained. Twenty-five patients with other skin disorders such as drug eruption, urticaria or herpes zoster were studied as controls in the PCR analysis. RESULTS: HHV-7 DNA was detected in 13 of 30 (43%) samples of PBMC of the patients with PR and 14 of 25 (56%) samples of PBMC of controls. HHV-6 DNA was detected in six of 29 (21%) patients with PR and nine of 23 (39%) controls. Thus there was no difference in the prevalence of HHV-6 or HHV-7 in PBMC between patients with PR and those with other skin disorders. In the seroepidemiological study, two cases of at least a fourfold rise in titre and five cases of a fourfold decrease in titre to HHV-7 antibody, and two cases of a fourfold rise in titre and two cases of a fourfold decrease in titre to HHV-6 antibody, were observed in 24 patients with PR. This seroepidemiological study revealed antibody responses consistent with active infection in several PR patients, but the greater proportion of the patients had no definite increase in the antibody titres. CONCLUSIONS: We conclude that HHV-7 and HHV-6 may play a part in some patients with PR, but that other causative agents may exist. Further analyses are needed to determine the causative agents of PR.

Adolescent↗

IgE antibody to fish gelatin (type I collagen) in patients with fish allergy.

BACKGROUND: Most children with anaphylaxis to measles, mumps, and rubella vaccines had shown sensitivity to bovine gelatin that was included in the vaccines. Recently, it was found that bovine type I collagen, which is the main content in the gelatin, is a major allergen in bovine gelatin allergy. Fish meat and skin also contain type I collagen. OBJECTIVE: The present study was designed to investigate IgE antibody to fish gelatin in children with fish allergy. METHODS: Serum samples were taken from patients in 3 groups: (1) 10 patients with fish allergy and specific IgE to fish meat; (2) two patients with allergies to both fish meat and bovine gelatin and specific IgE to fish meat and bovine gelatin; and (3) 15 patients with atopic dermatitis and specific IgE to fish meat. Various fish gelatins (type I collagen) were prepared from fish skin. IgE antibody to fish gelatin was analyzed by using ELISA and immunoblotting. RESULTS: Of 10 patients with fish allergy, 3 had specific IgE to fish gelatin. Of two patients with fish allergy and bovine gelatin allergy, all had specific IgE to fish gelatin. Of 15 patients with atopic dermatitis and specific IgE to fish meat, 5 had specific IgE to fish gelatin. Furthermore, IgE from pooled serum of the patients reacted with both the alpha1 and alpha2 chains of fish type I collagen in immunoblots. There is cross-reactivity among gelatins from various fishes, but there is little cross-reactivity between fish and bovine gelatins. CONCLUSION: Some fish-sensitive patients possessed IgE antibody to fish gelatin. Fish gelatin (type I collagen) might be an allergen in subjects with fish allergy.

Adolescent↗

Alterations in large and small proteoglycans in bleomycin-induced pulmonary fibrosis in rats.

In bleomycin (BM)-induced lung fibrosis, alterations have been shown in the expression and deposition of small proteoglycans (PGs). Less, however, is known about changes in large PGs. We investigated changes in large aggregating (versican [VS]), basement membrane (heparan sulfate proteoglycan [HSPG]), and small (biglycan and fibromodulin) PGs during the development of BM-induced pulmonary fibrosis. BM (1.5 U) was instilled intratracheally into male Sprague-Dawley rats. Control rats received saline. At 7, 14, and 28 d after administration of BM, lungs were excised; one lung was fixed in formalin and 5-microm sections were cut and stained with hematoxylin-eosin. The other lung was used for PG extraction. PGs were extracted with guanidine and were separated through composite gel polyacrylamide gel electrophoresis (PAGE) (large PGs) and sodium dodecylsulfate-PAGE (small PGs). Gels were either stained or electrophoretically transferred and probed with antibodies to VS, HSPG, biglycan, and fibromodulin. Histologic samples showed prominent inflammation, with abundant proteinaceous material, most evident in the samples obtained at 7 and 14 d after administration of BM. By 28 d after BM, much of the inflammatory response had resolved, and heterogeneous distribution of fibrosis was observed. Immunoblots showed a relative abundance of VS at 7 and 14 d. Control lungs stained minimally for VS. Levels of HSPG, biglycan, and fibromodulin were increased maximally at 14 d after administration of BM. Immunocytochemistry showed intense immunostaining of biglycan and fibromodulin in the areas of injured lung tissue from rats 14 and 28 d after BM administration. Control lungs revealed minimal staining for small PGs. Our findings indicate that changes in all subclasses of PGs occur during the development of BM-induced pulmonary fibrosis.

Animals↗