Biomedical subjects

O Tasaki

Publications and source records attributed to O Tasaki.

14 recordsLinked to original sources

PubMed2001

Cosmetic and functional reconstruction achieved using a split myofascial bone flap for pterional craniotomy. Technical note.

Cosmetic deformities that appear following pterional craniotomy are usually caused by temporal muscle atrophy, injury to the frontotemporal branch of the facial nerve, or bone pits in the craniotomy line. To resolve these problems during pterional craniotomy, an alternative method was developed in which a split myofascial bone flap and a free bone flap are used. The authors have used this method in the treatment of 40 patients over the last 3 years. Excellent cosmetic and functional results have been obtained. This method can provide wide exposure similar to that achieved using Yaşargil's interfascial pterional craniotomy, without limiting the operative field with a bulky temporal muscle flap.

Bone and Bones↗

PubMed2000

Cerebral aneurysm associated with an anomalous hyperplastic anterior choroidal artery.

An unruptured internal carotid artery (ICA) aneurysm arising at the origin of a hyperplastic anomalous AchoA was identified together with a second unruptured middle cerebral artery aneurysm during angiography performed to investigate a striatal and intraventricular haemorrhage in a 55-years-old woman. The anomalous hyperplastic AchoA supplied the left temporal and occipital lobes, and the aneurysm arose proximal to its origin. The patient underwent clipping of the aneurysms, and intra-operative observation revealed that several perforating branches arose directly from the ICA between the AchoA and the ICA bifurcation.

Carotid Artery Diseases↗

PubMed2000

[Surgical treatment of unruptured cerebral aneurysms and complications in patients with ischemic cerebrovascular disease].

Patients who have unruptured intracranial aneurysms associated with ischemic cerebrovascular disease are a high-risk group for surgery. We have done clipping surgery in 15 patients among 40 with ischemic cerebrovascular disease. The criteria for surgery included an age below 65 years, CBF of more than 35 ml/100 g/min, and favorable ADL comparable to Rankin score 0-III. Two patients received simultaneous aneurysm clipping and superficial-middle cerebral artery anastomosis. Only one patient suffered from ischemia-related permanent neurological worsening, and one had direct optic nerve injury. Surgical mortality was 0%, and morbidity was 15%. There were two patients who had transient neurological worsening. These results suggest that surgical treatment of unruptured cerebral aneurysms is not contraindicated in patients with ischemic brain disease, but careful selection and careful perioperative management are mandatory for preventing surgical complications.

Activities of Daily Living↗

PubMed1999

Effects of long-term hemofiltration on circulating mediators and superoxide production during continuous endotoxin administration.

BACKGROUND: The purpose of this study was to test whether continuous hemofiltration eliminates cytokines and eicosanoids, or stimulates granulocyte function. METHODS: Nineteen pigs were divided into a control group (n = 7), a hemofiltration group (n = 7), and an extracorporeal circuit only group (n = 5). All animals received the same amount of intravenous endotoxin and resuscitation fluid. Zero-balanced hemofiltration was started 30 minutes after initiation of endotoxemia and continued throughout the experiment. Plasma endotoxin, tumor necrosis factor-alpha, eicosanoids, superoxide production, and other physiologic parameters were measured before challenge and at scheduled intervals thereafter. RESULTS: Eicosanoids were filtered but plasma concentrations were not reduced. Tumor necrosis factor-alpha was not filtered or adsorbed. There were no significant differences between groups in any measured parameters. CONCLUSION: Continuous hemofiltration could not efficiently remove tumor necrosis factor-alpha or eicosanoids. Also, continuous hemofiltration did not stimulate production of the proinflammatory mediators measured, nor improve respiratory distress.

6-Ketoprostaglandin F1 alpha↗

PubMed1999

Selectin blockade worsened lipopolysaccharide-induced lung injury in a swine model.

BACKGROUND: Polymorphonuclear leukocytes have been reported to play an important role in various acute lung injuries. Neutrophil recruitment into tissues is a multistep process involving sequential engagement of adhesion molecules. The objective of this study was to determine the effect of selectin inactivation with Sulfo Lewis C (SO3-3betaGal1-3betaGlcNAc-O(CH2)8-COOMe) on the pulmonary response to lipopolysaccharide (LPS) infusion. METHODS: All animals (n = 11) were pretreated with an intramuscular injection of a priming dose of Escherichia coli LPS (10 microg/kg). Eighteen hours later, animals received an intravenous infusion of LPS (20 microg/kg) over 20 minutes. All animals were resuscitated with a lactated Ringer's solution. Group I (G1; n = 5) received no additional treatment. Group II (G2; n = 6) received a bolus injection of Sulfo Lewis C (10 mg/kg) 10 minutes before LPS insult followed by a continuous infusion (1 mg/kg per hour) for the rest of the study. Animals were observed for 5 hours from initiation of the LPS infusion and killed. Cardiopulmonary variables and blood gases were measured serially. The multiple inert gas elimination technique (MIGET) was used to evaluate the matching of air flow and blood flow in the lung 5 hours after LPS infusion. Histologic evaluation of the parenchymal injury was performed by using light microscopy. The number of polymorphonuclear leukocytes and red blood cells in the alveolar spaces per field at 400x magnification were counted in 10 randomly selected fields. RESULTS: Hypoxemia, indexed as Pao2/FIO2, was exacerbated by the administration of Sulfo Lewis C (G1:437+/-33 vs. G2: 241+/-63 mm Hg at 5 hours, p<0.03). This finding is supported by the multiple inert gas elimination technique analysis, which demonstrated significantly greater blood flow to true shunt in G2 (G1:4.42+/-1.75 vs. G2:23.2+/-5.69, p<0.02). There was no difference between the two groups in red blood cell counts in the alveolar spaces. However, polymorphonuclear leukocyte counts were significantly greater in G2 (G1:1.8+/-0.58 vs. G2:9.9+/-2.34, p<0.01). CONCLUSION: Selectin blockade significantly worsened lung injury induced by LPS infusion, and greater numbers of neutrophils were observed in alveolar spaces in the group treated with Sulfo Lewis C. These findings are supported by the multiple inert gas elimination technique analysis, which demonstrated significantly greater blood flow to the true shunt compartment in treated animals. Further studies are required to determine the role of selectins in sepsis-induced lung injury.

Animals↗

PubMed1999

Biphasic changes in left ventricular function during hyperdynamic endotoxemia.

Cardiac contractility was studied in a clinically relevant conscious swine model simulating human hemodynamics during endotoxemia. The slope of the end-systolic pressure-volume relationship [end-systolic elastance (EES)] was used as a load-independent contractility index. Chronic instrumentation in 10 pigs included two pairs of endocardial ultrasonic crystals for measuring internal major and minor axial dimensions of the left ventricle, a micromanometer for left ventricular pressure measurement, and a thermodilution pulmonary artery catheter. After a 10-day recovery period, control measurements of cardiac hemodynamic function were obtained. The following week, Escherichia coli endotoxin (10 micrograms . kg-1. h-1) was administered intravenously for 24 h. EES increased 1 h after endotoxin infusion and decreased beyond 7 h. The later hemodynamic changes resembled human cardiovascular performance during endotoxemia more closely than the changes during the acute phase. EES decreased in the later phase. A similar biphasic response of EES has been reported during a tumor necrosis factor-alpha (TNF) challenge. Even though plasma TNF was highest at 1 h and declined thereafter in this study, no consistent relationship between TNF and EES was identified, and TNF levels did not correlate directly with the changes in EES.

Animals↗

PubMed1999

[Cigarette smoking increases the risk of developing a cerebral aneurysm and of subarachnoid hemorrhage].

Despite recent advances in diagnostic and therapeutic techniques, subarachnoid hemorrhage (SAH) is still a serious condition associated with high mortality and morbidity. There are no effective treatments other than surgical intervention. However, another option for decreasing the occurrence of SAH may be prevention of aneurysms formation and of their rupture by controlling risk factors. Cigarette smoking has been recently shown to be one of the major risk factors for SAH. We investigated whether cigarette smoking increased the risk of developing cerebral aneurysms and of SAH. Degree of smoking was investigated in 182 patients with SAH and in 123 patients with an unruptured cerebral aneurysm incidentally detected during investigation of other diseases. Sixty-nine patients with other diseases who were shown to be free of cerebral aneurysms through MR angiography served as controls. Smoking significantly increased the risk of both aneurysm formation and SAH; The odds ratio for SAH was 2.4, and for unruptured cerebral aneurysm 1.7. Smoking especially increased the occurrence of SAH in women and in youngsters. However, smoking did not influence the occurrence of cerebral vasospasm and multiplicity of aneurysms. These data suggest the importance of avoiding smoking to prevent the occurrence of cerebral aneurysms and of SAH.

Age Factors↗

PubMed1998

Effect of Sulfo Lewis C on smoke inhalation injury in an ovine model.

OBJECTIVE: To evaluate the effect of Sulfo Lewis C (SO3-3âGal1-3GlcNAc-O(CH2)8-COOMe), a putative ligand of selectins, on smoke inhalation injury. DESIGN: Prospective animal study with concurrent controls. SETTING: An animal laboratory. SUBJECTS: Twelve 1-yr-old female sheep, weighing 24 to 33 kg. INTERVENTIONS: Twelve sheep received nine exposure units of smoke generated by thermolysis of pine woodchips (80 g). Group 1 (n = 6) was untreated. Group 2 (n = 6) was treated with an intravenous infusion of Sulfo Lewis C after smoke exposure. Animals were killed 48 hrs after injury. MEASUREMENTS AND MAIN RESULTS: Cardiopulmonary variables and blood gases were measured serially. Granulocyte free-radical production was measured before smoke exposure and at 4 and 48 hrs after injury. Ventilation/perfusion distribution (VA/Q) was analyzed using the multiple inert gas elimination technique. Granulocyte free-radical production was increased after smoke exposure in both groups. Oxygenation was significantly improved by the administration of Sulfo Lewis C. VA/Q analysis demonstrated significantly less blood flow to low VA/Q lung segments in treated animals. CONCLUSIONS: Selectin blockade attenuated lung injury after smoke exposure. These data support the hypothesis that neutrophils play a pivotal role in smoke inhalation injury.

Animals↗

PubMed1998

Inhaled nitric oxide prevents left ventricular impairment during endotoxemia.

We evaluated the effect of long-term inhalation of nitric oxide (NO) on cardiac contractility after endotoxemia by using the end-systolic elastance of the left ventricle (LV) as a load-independent contractility index. Chronic instrumentation in 12 pigs included implantation of two pairs of endocardial dimension transducers to measure LV volume and a micromanometer to measure LV pressure. One week later, the animals were divided into a control group (n = 6) or a NO group (n = 6). All animals received intravenous Escherichia coli endotoxin (10 micrograms. kg-1. h-1) and equivalent lactated Ringer solution. NO inhalation (20 parts/million) was begun 30 min after the initiation of endotoxemia and was continued for 24 h. In both groups, tachycardia, pulmonary hypertension, and systemic hyperdynamic changes were noted. The end-systolic elastance in the control group was significantly decreased beyond 7 h. NO inhalation maintained the end-systolic elastance at baseline levels and prevented its impairment. These findings indicate that NO exerts a protective effect on LV contractility in this model of endotoxemia.

Administration, Inhalation↗

PubMed1997

Paradoxical positive nitrogen balance in burn patients receiving high-dose administration of insulin for nutritional care.

BACKGROUND: Nitrogen balance in patients who need high-dose administration of insulin has not been evaluated clinically. The purpose of this study was to compare the difference in nitrogen balance between burn patients who received high-dose administration of insulin and those who did not. METHODS: This study was performed in 19 severely burned adults with no liver or kidney failure. Patients were divided into two groups on the basis of the mean ratio of administered insulin and calorie intake (I/C) for the initial 4 weeks, a high I/C group (n = 9) and a low I/C group (n = 10). There were no significant differences between the two groups regarding age, percentage of area burned, and body weight. Nitrogen balance, blood urea nitrogen, and urine urea nitrogen were measured in all patients. Plasma concentrations of glucose, insulin, glucagon, cortisol, and urinary excretion of 3-methyl-histidine were measured in 12 patients (six in each group). RESULTS: Until day 10 both groups exhibited similar changes in plasma concentrations of glucose, insulin, glucagon, and cortisol. Subsequently, plasma concentrations of insulin and glucagon began to decrease in the low I/C group, whereas a high level was sustained in the high I/C group (p < 0.05). Plasma glucose and cortisol measurements showed no significant differences between the two groups. Blood urea nitrogen levels and urinary excretion of 3-methyl-histidine were not different between the two groups. Urine urea nitrogen excretion in the high I/C group, however, was significantly lower than that in the low I/C group from day 8 (p < 0.05). Thus the high I/C group achieved positive nitrogen balance more quickly than the low I/C group. Paradoxically, however, the high I/C group was at higher risk of septic complications and exhibited higher mortality than the low I/C group (p < 0.05). CONCLUSIONS: These results indicate that an improvement in nitrogen balance, which is accepted as a good thing in the management of critically ill patients, is not necessarily good in the high I/C group and that residual nitrogen was retained within the body in the high I/C group.

Adult↗

PubMed1997

Effects of burns on inhalation injury.

BACKGROUND: There are few studies of smoke injury combined with thermal burn. METHODS: Seven sheep (G1) received smoke injury alone; eight (G2) received a 40% full-thickness scald burn immediately after smoke injury. All animals were resuscitated with lactated Ringer's solution and killed 48 hours after injury. Cardiopulmonary variables and blood gases were measured serially. Ventilation perfusion distribution was analyzed using the multiple inert gas elimination technique. Lung wet to dry weight ratio and malondialdehyde levels were determined. RESULTS: G2 resulted in early significant hemodynamic changes. Serum total protein concentration was significantly lower and malondialdehyde significantly higher in G2. However, PaO2, lung wet to dry weight ratio, and ventilation perfusion mismatching in G2 did not differ from those in G1. CONCLUSIONS: Although the addition of burn injury exaggerated the lung lipid peroxidation and hypoproteinemia in the presence of more pronounced hemodynamic changes, the pulmonary dysfunction was not accentuated.

Animals↗

PubMed1995

Differences in body temperature changes during dressing change in surviving and non-surviving burned patients.

Change in body temperature (delta BT) while dressings were being changed was measured in 52 extensively burned adults. The patients were divided into four groups based on outcome and the prognostic burn index (PBI; age + burn index): group I (15 survivors, PBI less than or equal to 80), group II (15 survivors, PBI between 80 and 120), group III (14 non-survivors, PBI between 80 and 120), and group IV (eight non-survivors, PBI greater than 120). The body temperature before the change of dressings was the same in the four groups. The mean(s.d.) delta BT in all patients was -0.5(0.8) degrees C. The magnitude of delta BT was not related to the time required for changing dressings (r = 0.04) or to the non-epithelialized area present at each change of dressings (r = -0.05). All groups showed a similar increase in delta BT during the early period after the burn, but in group I it began to decrease progressively after the 16th day after the burn (P < 0.05). A reduction in delta BT was noted in group II from day 25, whereas it was unchanged in groups III and IV (P < 0.05). It also significantly increased 2 days before the diagnosis of sepsis (P < 0.05). These results emphasize that delta BT may provide useful information about prognosis and the development of sepsis.

Adult↗

PubMed1995

Low oxygen extraction despite high oxygen delivery causes low oxygen consumption in patients with burns recovering slowly from operative hypothermia.

BACKGROUND: Patients with burns who eventually succumbed to their injuries tended to recover more slowly from operative hypothermia than those who survived. Slower recovery was associated with a lower postoperative oxygen consumption (VO2). We have now investigated whether this was due to impairment of oxygen delivery or extraction. METHODS: This study was performed in 13 adult patients with severely burns. One hundred four measurements of VO2 by indirect calorimetry were made during recovery from 23 episodes of operative hypothermia in 11 patients. Sixty-six measurements of oxygen transport variables by balloon-tipped pulmonary artery catheter were made after 17 episodes of operative hypothermia in six patients. Body temperature was monitored in the urinary bladder. RESULTS: The rate of temperature rise (T) showed a strong positive correlation with VO2 measured both by indirect calorimetry (r = 0.91, p < 0.001) and by balloon-tipped pulmonary artery catheter (r = 0.83, p < 0.001). Oxygen delivery (DO2) was above normal in nearly all patients. Oxygen extraction was low in patients recovering slowly (T < 1.0 degree C/hr) and high in those recovering quickly (T > or = 1.0 degree C/hr). During fast recovery VO2 (373 +/- 77 ml.min-1.m-2; mean +/- SD) was approximately three times normal and was independent of DO2. In contrast, a strong linear relationship existed between VO2 and DO2 during slow recovery (r = 0.76, p < 0.001). CONCLUSIONS: Patients with burns with slow recovery from operative hypothermia exhibited impaired oxygen extraction and dependence of VO2 on DO2 over a wide range. This picture resembles that in patients with critical illness.

Adult↗

PubMedDate not supplied

The dimer and trimer of 3-hydroxybutyrate oligomer as a precursor of ketone bodies for nutritional care.

BACKGROUND: Ketone bodies have been considered as a means of providing energy because of their good penetration and rapid diffusion in peripheral tissues. However, because the currently available form of 3-hydroxybu-tyrate is the sodium salt, the sodium load is problematic. To avoid it, a mixture of dimer and trimer has been prepared as a precursor of D-3-hydroxybutyrate. The purpose of this study was to investigate whether and how the solution would be converted to monomers. METHODS: The plasma concentration of 3-hydroxybutyrate monomer was measured in 10 rats during infusion of dimer and trimer. Stepwise dilutions of the solution were incubated with serum and liver homogenates from five rats, serum samples from five volunteers, and a liver sample from one patient with liver injury. The solution also was incubated with carboxylesterase and triacylglycerol lipase. The concentration of monomer in the medium was measured after incubation. RESULTS: The plasma concentration of 3-hydroxybutyrate monomer reached 572 +/- 11 micromol/L 15 minutes after beginning infusion of the mixture at a rate of 25 micromol x kg(-1) x min(-1) and 270 +/- 40 micromol/L at a rate of 12.5 micromol x kg(-1) min(-1). The solution was converted completely to monomers when incubated with rat serum or liver homogenate for 10 minutes. The mixture also was hydrolyzed by human liver homogenate but not by serum. CONCLUSIONS: The dimer and trimer of 3-hydroxybutyrate can be converted rapidly to monomer in rat and human tissues. 3-Hydroxybutyrate oligomers could be an energy substrate for injured patients.

3-Hydroxybutyric Acid↗