Surface free energies of silica fillers and their relation to the adsorption of poly(ethylene terephthalate)

The surface free energy of modified silica as well as of PET oligomers was evaluated through measurements of specific retention volumes of several probe molecules by use of the adsorption and adhesion principles in inverse gas chromatography. The nondispersive component of surface free energy of most silica fillers was larger than the dispersive component and the acidic component was much larger than the basic one, which indicated that the surfaces of most silica fillers were rather acidic. These methods were also applied to PET oligomer and it was found that the surface free energy of PET oligomer, regardless of preparation method, consisted of an almost dispersive component, suggesting that the surface of PET was neutral. The amount of PET oligomer adsorbed for the heat-treated silica fillers in acidic solvent increased linearly with increased acidic component of the surface free energy, which indicates that the acidic component of the surface free energy may be responsible for the adsorption. However, the adsorption amount on modified silica is much smaller than that for the heat-treated silica fillers because of steric hindrance caused by the attached organic chain, suggesting that the adsorption cannot be determined only by the surface free energy.

Posterolateral odontoidectomy for irreducible atlantoaxial dislocation: a technical case report

BACKGROUND CONTEXT

For the treatment of irreducible atlantoaxial dislocation (AAD), anterior decompression has been commonly used by removal of the odontoid process and fixation of the vertebral body by means of the transoral approach. Although the transoral approach has been well established, there are some disadvantages. By contrast, there have been few technical case reports of the posterolateral approach, especially for irreducible AAD.

PURPOSE

To describe a technical case report of the posterolateral approach for irreducible AAD, demonstrating the specific advantages.

STUDY DESIGN/SETTING

Technical case report.

PATIENT SAMPLE

Case report.

OUTCOME MEASURES

Report of postoperative symptoms.

METHODS/DESCRIPTION

A 74-year-old woman presented with sudden left hemiparesis because of irreducible AAD. She underwent the odontoidectomy and reduction by means of the posterolateral approach. Posterior fixation with instrumentation and an iliac bone graft was performed 16 days later. The results of radiological examinations were satisfactory. The posterolateral approach takes advantage of the particular features of C1-C2 dislocation of irreducible AAD.

CONCLUSIONS

We suggest the possibility that the posterolateral approach is feasible and effective in most cases with irreducible AAD.

Adsorption characteristics of organosilica based mesoporous materials

Hybrid organosilica mesoporous materials with pores of ordered three-dimensional hexagonal structure were prepared by the hydrolysis and co-condensation of 1,2-bis(triethoxysilyl)ethane with various concentrations of a surfactant as structure directing agents. The materials had high pore volume of 1-1.5 mL/g and high surface area from 1057 to 1445 m(2)/g. Adsorption measurement and adsorption calorimetry revealed that the prepared materials exhibited high hydrophobicity and high affinity toward nonpolar organic vapor such as n-hexane. The dynamic adsorption properties of the materials for n-hexane in the presence of water vapor showed that these hybrid organosilica materials preferentially adsorbed n-hexane vapor and were stable in the presence of water compared to the siliceous MCM48.

Overexpression of lipoprotein lipase improves insulin resistance induced by a high-fat diet in transgenic rabbits

AIMS/HYPOTHESIS

Dysfunctions of lipoprotein lipase (LPL) have been found to be associated with dyslipidaemias, atherosclerosis, obesity and insulin resistance. There are two conflicting hypotheses regarding the roles of LPL in glucose metabolism and insulin resistance. Whether systemically increased LPL activity would be beneficial or detrimental to insulin sensitivity is yet to be resolved. To address this issue, we studied transgenic rabbits overexpressing human LPL transgene.

METHODS

LPL transgenic and control rabbits were fed a 10% high-fat diet (HFD) for 16 weeks. To evaluate glucose metabolism, we compared plasma levels of glucose and insulin in transgenic rabbits with control rabbits and performed an intravenous glucose tolerance test. In addition, we measured adipose tissue accumulation in HFD-fed rabbits.

RESULTS

Increased LPL activity in transgenic rabbits resulted in a significant reduction of plasma triglycerides and non-esterified fatty acids, but not in basal levels of glucose and insulin. HFD feeding induced an elevation of plasma glucose levels accompanied by hyperinsulinaemia in control rabbits, but was significantly inhibited in transgenic rabbits. The intravenous glucose tolerance test showed that transgenic rabbits had faster glucose clearance associated with lower levels of insulin secretion than control rabbits. In addition, there was a significant reduction of body adipose tissue in transgenic rabbits compared with in control rabbits fed an HFD. Scanning electron microscopic examination revealed that adipocytes in transgenic rabbits were predominately small cells.

CONCLUSIONS/INTERPRETATION

Our results showed that systemically increased LPL activity improves insulin resistance and reduces adipose accumulation in transgenic rabbits, indicating that systemic elevation of LPL may have potential benefits for the treatment of insulin resistance and obesity.

NO-1886 decreases ectopic lipid deposition and protects pancreatic beta cells in diet-induced diabetic swine

The synthetic compound NO-1886 (ibrolipim) is a lipoprotein lipase activator that has been proven to be highly effective in lowering plasma triglycerides. Recently, we found that NO-1886 also reduced plasma free fatty acids and glucose in high-fat/high-sucrose diet-induced diabetic rabbits. In the current study, we investigated the effects of NO-1886 treatment on ectopic lipid deposition and the islet pathology in miniature swine fed a high-fat/high-sucrose diet. Our results showed that feeding this diet to miniature swine caused insulin resistance, increased lipid deposition in non-adipose tissue, such as in the heart, skeletal muscle, liver and pancreas, and also caused pancreatic beta cell damage. However, supplementing 1% NO-1886 (200 mg/kg per day) into the high-fat/high-sucrose diet decreased ectopic lipid deposition, improved insulin resistance, and alleviated the beta cell damage. These results suggest that improvement of lipid disorder, non-adipose tissue steatosis and insulin resistance may be very important for the protection of beta cell damage. Therefore, NO-1886 is potentially beneficial for the treatment of insulin-resistance syndrome.

Effectiveness of the head-shaking method combined with cisternal irrigation with urokinase in preventing cerebral vasospasm after subarachnoid hemorrhage

OBJECT

The head-shaking method combined with cisternal irrigation has been proposed to be effective in preventing cerebral vasospasm after subarachnoid hemorrhage (SAH) by facilitating rapid washout of the clot from the subarachnoid space. This study was conducted to evaluate the effectiveness of this method.

METHODS

The inclusion criteria included the following: 1) Fisher Grade 3 SAH on admission computerized tomography (CT) scans; 2) aneurysm secured within 48 hours of SAH onset; and 3) no focal deficit and ability to obey commands within 24 hours postsurgery. Two hundred thirty patients treated between 1994 and 2002 fulfilled the criteria. Because only one machine was available and it required I month of maintenance every other month, 114 patients underwent irrigation combined with the head-shaking method (head-shaking group), whereas the remaining 116 patients received cisternal irrigation alone (control group). There were no significant differences in sex, age, site of aneurysm, or preoperative grade between the two groups. The incidence of symptomatic vasospasm with or without infarction, cerebral infarction on CT scans, and permanent ischemic neurological deficit was 25.7, 17.7, and 8.8%, respectively, in the control group and 15.2, 4.5, and 2.7% in the head-shaking group. The difference was statistically significant for symptomatic vasospasm, cerebral infarction, and permanent ischemic neurological deficit (p < 0.05). In a multivariate backward stepwise logistic regression analysis, absence of head shaking was the only variable that was predictive of permanent ischemic neurological deficit (p = 0.061). The outcomes evaluated using the modified Rankin Scale were better in the head-shaking group (p = 0.051).

CONCLUSIONS

The head-shaking method significantly reduced the incidence of symptomatic vasospasm, cerebral infarction, and permanent ischemic neurological deficit and improved the clinical outcomes in patients who underwent cisternal irrigation therapy after aneurysmal SAH.

Esophageal carcinoma with tracheal stenosis due to tumor invasion and long survival after chemoradiotherapy

For patients who have esophageal carcinoma with tracheal invasion surgery is usually not indicated because operative complications are considerable and the prognosis is poor. We experienced complete regression of a large esophageal carcinoma with tracheal stenosis due to tumor invasion without tracheo-esophageal fistula. Irradiation of 68 Gy was delivered to a long T field from the neck to the lower thoracic esophagus, and was combined with chemotherapy using cisplatin and 5-fluorouracil. The tumor decreased markedly in size and the tracheal stenosis resolved. The patient has survived for 4 years, although second primary early esophageal carcinoma and hypopharyngeal carcinoma were detected 2 years after his initial chemoradiotherapy. Although the prognosis of advanced esophageal carcinoma with invasion of other organs is usually poor, the effect of chemoradiotherapy can sometimes be dramatic and a good result can be achieved in such patients.

[Vertebrobasilar artery dissection with subarachnoid hemorrhage after brain stem infarct showing an improvement on angiography: case report]

A 66-year-old male presented with dysarthria and right hemiparesis. Cerebral angiography at onset showed obliteration of the basilar artery and dilatation in the left vertebral artery. The patient's clinical symptoms were exaggerated and he was finally diagnosed to as suffering locked-in syndrome. Magnetic resonance imaging showed a brain stem infarction from the pons to the left middle cerebellar peduncle. We determined that the patient suffered dissection of the left vertebral artery at the basilar artery and treated, using the conservative therapy him of strict blood pressure control. A second angiography 13 days after onset showed recanalization of the basilar artery. At 29 days after onset, the patient fell into a coma with subarachnoid hemorrhage and acute hydrocephalus. Cerebral angiography revealed improvement in the irregularity and dilatation of the basilar artery, but the point of rupture could not be clearly identified. After performing proximal occlusion of the left vertebral artery by intravascular surgery, both right STA-SCA anastomosis and proximal occlusion of the right vertebral artery were carried out. Unfortunately, the patient died. Based on there data, it is appointed out that patients with a dissection of the vertebrobasilar artery must be followed up by serial angiography, and even if an angiographical improvement of the dissection is observed, the risk of subarachnoid hemorrhage still exists in patients suffering ischemic stroke.

Adult-onset moyamoya disease with repetitive ischemic attacks successfully treated by superficial temporal-middle cerebral artery bypass--case report

A 78-year-old Japanese woman presented with adult-onset moyamoya disease manifesting as repetitive ischemic attacks over a period of 26 years. Initial ischemic attack occurred at age 52 years. Neurological status deteriorated, associated with worsening in angiographical and single photon emission computed tomography findings over the last 10 years. She suffered frequent transient attacks of aphasia and right hemiparesis. Superficial temporal-middle cerebral artery anastomosis was performed. Postoperative angiography and single photon emission computed tomography revealed a marked increase in cerebral blood flow and symptoms showed considerable improvement. Direct revascularization may be the treatment of choice even for aged patients with moyamoya disease.

Lipoprotein Lipase and Atherosclerosis

Lipoprotein lipase (LPL) is a rate-limiting enzyme that hydrolyzes circulating triglyceride-rich lipoprotein such as very low density lipoproteins and chylomicrons. A decrease in LPL activity is associated with an increase in plasma triglycerides (TG) and decrease in high density lipoprotein (HDL) cholesterol. The increase in plasma TG and decrease in HDL cholesterol are risk factors of coronary heart disease. However, whether LPL directly or indirectly promotes or protects against atherosclerosis remains unclear as two contrary views exist in this regard: one where LPL promotes atherosclerosis and one where LPL protects against atherosclerosis. Many studies have been carried out to investigate whether LPL is an anti-atherogenic or atherogenic enzyme by using animals with genetic defects or with an excess of this enzyme. From these studies, much evidence has been acquired showing that LPL is an anti-atherogenic enzyme. We hypothesized that elevating LPL activity would cause a reduction of plasma TG and increase in HDL cholesterol, resulting in protection against the development of atherosclerosis. To test this hypothesis, we studied the effects of the LPL activator NO-1886 in animals. NO-1886 has been shown to increase LPL mRNA in adipose tissue and myocardium, and increase LPL activity in adipose tissue, myocardium and skeletal muscle, resulting in an elevation of postheparin plasma LPL activity and LPL mass in rats. NO-1886 has also been shown to decrease plasma TG levels accompanied by a concomitant rise in HDL cholesterol. Long-term administration of NO-1886 to rats and rabbits with experimental atherosclerosis inhibited the development of atherosclerotic lesions in coronary arteries and aortae. The results of multiple regression analysis in these studies suggest that the increase in plasma HDL cholesterol and the decrease in TG protect against atherosclerosis. We have determined in our studies that the atherogenic lipid profile is changed to an anti-atherogenic lipid profile by increasing LPL activity, resulting in protection against the development of atherosclerosis. Therefore, we believe that high activity of LPL is anti-atherogenic, whereas a low activity of LPL is atherogenic.

Mechanisms of snowboarding-related severe head injury: shear strain induced by the opposite-edge phenomenon

Object. To date, there has been no published study in which the focus was on the mechanisms of head injuries associated with snowboarding. The purpose of this study was to identify these mechanisms.

Methods. The patient population consisted of 38 consecutive patients with snowboarding-related major head injuries who were treated at two hospitals in Japan, where for years many winter sports injuries have been treated. The skill level of the snowboarder, the cause of the accident, the direction of the fall, the site of impact to the head, and the condition of the ski slope were examined. The injuries were classified as coup, contrecoup, or shear injuries.

The predominant features of snowboarding-related major head injuries included: falling backward (68% of cases), occipital impact (66% of cases), a gentle or moderate ski slope (76% of cases), and inertial injury (76% of cases [shear injury in 68% and contrecoup injury in 8% of the patients]). Acute subdural hematoma frequently occurred after a patient fell on the slope (p = 0.025), fell backward (p = 0.0014), or received an occipital impact (p = 0.0064). Subcortical hemorrhagic contusions frequently occurred after the patient fell during a jump (p = 0.0488), received a temporal impact (p = 0.0404), or fell on the jump platform (p = 0.0075). Shear injury frequently occurred after a fall that occurred during a jump or after simple falls on the ski slope, and contact injury was frequently seen after a collision (p = 0.0441).

Conclusions. The majority of severe head injuries associated with snowboarding that occur after a simple fall on the slope are believed to involve the opposite-edge phenomenon, which results from a fall backward on a gentle or moderate slope causing occipital impact. The use of a device to protect the occiput is proposed to reduce head injuries associated with snowboarding.

Inspired superoxide anions attenuate blood lactate concentrations in postoperative patients

OBJECTIVE

Low concentrations of superoxide (O(2)(-)) constitute a portion of atmosphere negative ions in the form of O(2)-(H(2)O)(n), which has been reported to have a stimulatory effect on superoxide dismutase activity. If superoxide dismutase is activated by inspired negative ions containing O(2)(-), aerobic metabolism could be improved. To test this hypothesis, we examined blood lactate concentrations in postoperative patients with or without inhalation of air from a home humidifier that generates O(2)-(H(2)O)(n).

DESIGN

Prospective, randomized, controlled trial.

SETTING

Neurosurgical intensive care unit of a general hospital.

PATIENTS

Twenty postneurosurgical patients with arterial blood lactate concentrations >1.5 mmol/L were studied and were divided randomly into two groups.

INTERVENTIONS

One group received 40 L/min 40% oxygen flow from a home humidifier as an oxygen therapy for 4 hrs, followed by almost the same flow from a jet nebulizer, which generates positive ions, for 4 hrs. The other group received the reverse combination.

MEASUREMENTS AND MAIN RESULTS

During the 8-hr study, arterial blood lactate concentrations were measured every hour. There was a significant difference in the time course of blood lactate concentrations between the groups. In the group in which negative ions were first initiated for 4 hrs and positive ions thereafter, the lactate concentration decreased slightly at 3, 4, and 5 hrs and returned to the baseline concentration thereafter. In the group with the reverse combination, the lactate concentration did not change during the first 4 hrs but decreased thereafter after inhalation of negative ions.

CONCLUSIONS

Inspired O(2)(-) attenuates blood lactate concentrations. This may be attributed, in part, to the systemic stimulatory effect on superoxide dismutase activity, which accelerates oxidative phosphorylation in the mitochondria, thus attenuating lactate generation.

Infra-posterior inferior cerebellar artery aneurysm arising after occlusion of the ipsilateral vertebral artery--case report

An 85-year-old woman had subarachnoid hemorrhage due to rupture of a very rare left infra-posterior inferior cerebellar artery (PICA) aneurysm, a saccular aneurysm located proximally at the junction of vertebral artery (VA) and PICA. Right vertebral angiography demonstrated the aneurysm since the left VA was occluded in the extracranial portion. The aneurysm projected in the opposite direction to common VA-PICA aneurysms. The angiographical and intraoperative findings imply this rare aneurysm resulted from the hemodynamic changes caused by the VA occlusion. Detailed exploration of angiography is emphasized to detect such rare aneurysms among the diversity of hemodynamic patterns in elderly patients with subarachnoid hemorrhage.

Efficiency of an air filter at the drainage site in a closed circuit with a centrifugal blood pump: an in vitro study

In a closed circuit with a centrifugal blood pump, one of the serious obstacles to clinical application is sucking of air bubbles into the drainage circuit. The goal of this study was to investigate the efficiency of an air filter at the drainage site. We used whole bovine blood and the experimental circuit consisted of a drainage circuit, two air filters, a centrifugal blood pump, a membrane oxygenator, a return circuit, and a reservoir. Air was injected into the drainage circuit with a roller pump, and the number and size of air bubbles were measured. The air filter at the drainage site could remove the air bubbles (>40 microm) by itself, but adding a vacuum removed more bubbles (>40 microm) than without vacuum. Our results suggest that an air filter at the drainage site could effectively remove air bubbles, and that adding the filter in a closed circuit with a centrifugal blood pump would be safer.

Delayed central respiratory dysfunction after Wallenberg's syndrome--case report

A 68-year-old man presented with Wallenberg's syndrome consisting of ataxia, dysphagia, hypesthesia on the left side of the body, and Horner's syndrome on the right. Magnetic resonance (MR) imaging revealed a right lateral medullary infarction and small multiple lacunae scattered in the upper medulla. Neurological symptoms improved in a week and the patient was discharged with mild residual hypesthesia on the left side. However, 31 days later, he was emergently admitted after suddenly becoming apneic and losing consciousness. MR imaging detected no new lesion. The patient was placed under ventilation support for 48 hours before regaining normal respiratory function. Medullary infarction sometimes causes catastrophic respiratory failure, but Wallenberg's syndrome caused by lateral medullary infarction is rarely associated with central respiratory dysfunction, and delayed onset of central respiratory dysfunction is extremely unusual. Delayed onset of central respiratory failure is a life-threatening complication of the medullary infarction causing Wallenberg's syndrome, which in general is not recognized.

The effect of pregnancy on cytochrome P4501A2, xanthine oxidase, and N-acetyltransferase activities in humans

OBJECTIVE

Our objective was to evaluate the activity of cytochrome P4501A2 (CYP1A2), xanthine oxidase (XO), and N-acetyltransferase 2 (NAT2) from early to late pregnancy and after delivery.

METHODS

Twelve women were studied on three occasions during pregnancy (early, 8-16 weeks' gestation; middle, 20-28 weeks' gestation; and late, 32-39 weeks' gestation) and about 1 month after delivery. Caffeine was used as a metabolic probe. After the women ingested a can or a bottle of caffeine-containing soft drink, urine samples were collected for 12 hours. The caffeine metabolites measured were 5-acetylamino-6-amino-3-methyluracil (AAMU), 1-methylxanthine (1X), 1-methyl-uric acid (1U), 1,7-dimethyl-uric acid (17U), and 1,7-dimethylxanthine (17X). The hepatic enzyme activities were estimated by the urinary caffeine metabolic ratios as follows: CYP1A2 = (AAMU + 1X + 1U)/17U; XO = 1U/(1X + 1U); NAT2 = AAMU/(AAMU + 1X + 1U).

RESULTS

Statistically significant differences were found in CYP1A2 (P < .0001) and NAT2 (P < .01). The mean metabolic ratios for CYP1A2 during pregnancy (6.80, 5.18, and 4.97 for the early phase, middle phase, and late phase, respectively) were significantly lower than the ratio after delivery (10.39). The mean metabolic ratio for NAT2 in the early phase (0.57) was significantly lower than after delivery (0.66). There was no significant difference in metabolic ratios for XO during pregnancy and after delivery.

CONCLUSION

The data demonstrate that pregnancy influences CYP1A2 and NAT2 activity. CYP1A2 activity decreases not only in late pregnancy but also in early and middle pregnancy.