Takako Tsuda

Induction of blood-brain barrier properties in immortalized bovine brain endothelial cells by astrocytic factors.

The blood-brain barrier (B-BB) protects the free passage of substances into the brain and maintains the homeostasis of the central nervous system. It is commonly accepted that astrocytes surrounding brain endothelial cells influence the B-BB formation and the exhibition of B-BB function of capillaries. To begin the in vitro study on the B-BB, it is essential to obtain a homogenous and sufficient supply of brain endothelial cells as well as astrocytes. We thus immortalized the bovine brain endothelial cell (BBEC) by transfection of the SV40 large T antigen and obtained a single clone, t-BBEC-117, which retained the brain endothelial cell phenotype. Astrocyte in co-culture was found to tighten the intercellular contacts of the immortal cells resulting in a reduced L-glucose permeability, and its conditioned medium (CM) augmented a B-BB phenotype, alkaline phosphatase (ALP) activity. Among known astrocytic factors, only fibroblast growth factor-basic (bFGF) could mimic the actions of astrocytes as measured by L-glucose permeability and ALP activity. Moreover, anti-bFGF antibody canceled 90% of ALP activation by astrocyte CM. Basic FGF, however, failed to induce other B-BB phenotypes such as the expressions of multidrug resistance (mdr) and glucose transporter (GLUT-1) genes. These data suggest that bFGF is one of the most plausible astrocytic factors to induce the B-BB properties of immortal brain endothelial cells together with some unknown factors in the astrocyte CM.

Lactic acid increases aquaporin 4 expression on the cell membrane of cultured rat astrocytes

The water channel protein aquaporin (AQP) may play roles in the homeostasis of water content in the brain and brain edema. One possible mechanism of brain edema is glial swelling due to lactic acidosis associated with ischemia. Here, we investigated the effect of lactic acid on the expression and cellular distribution of AQP 4 in cultured rat astrocytes. After 24h of incubation, the AQP4 expression level increased maximally with 35mM lactic acid. The AQP4 expression levels also increased with hydrochloric acid or acetic acid. In contrast, with sodium lactate, the AQP4 levels did not increase. The increase in AQP4 expression level occurred without a significant increase in AQP4 mRNA expression level by lactic acid. Under the conditions of de novo protein synthesis inhibition with cycloheximide, lactic acid increased the AQP4 expression level. Furthermore, lactic acid increased the AQP4 expression level on the cell surface of the astrocytes, as determined by a cell surface biotinylation assay and immunocytochemical examination. The increase in AQP4 expression level on the cell membrane of astrocytes induced by lactic acid may be a new regulation mechanism of AQP4 in the brain.

A case of complex regional pain syndrome type II after transradial coronary intervention

The transradial approach for coronary catheterization is now a routine technique without serious complications at the puncture site. We report a case of complex regional pain syndrome type II (CRPS type II) in the hand after the transradial coronary intervention, which may alert medical personnel that the technique may cause serious regional pain with disability. A 61-year-old woman underwent coronary intervention via the right radial artery for the treatment of unstable angina. After the operation she complained of severe pain in the right hand, consistently felt along the median nerve distribution. The nerve conduction study suggested carpal tunnel syndrome. We made a diagnosis of CRPS type II, and the patient received stellate ganglion blockade, cervical epidural blockade, and administration of amitriptyline and loxoprofen. The symptoms gradually improved and her activities of daily living markedly improved. The median nerve appeared to be damaged by local compression and potential ischemia. Careful attention should be paid to avoid CRPS type II, associated with excess compression.

Effect of mild hypothermia on the expression of aquaporin family in cultured rat astrocytes under hypoxic condition

Aquaporins (AQPs) are a family of water-selective transporting proteins with homology to the major intrinsic protein (MIP) of lens, that increase plasma membrane water permeability in secretory and absorptive cells. In this study, we investigated the effect of mild hypothermia on the expression of AQP4, AQP5 and AQP9 in rat astrocytes cultured under hypoxic conditions. At 37 degrees C, a marked decrease in the expression of AQP4, AQP5 and AQP9 mRNAs was observed. However, at 32 degrees C (mild hypothermia), the expression of AQP5 mRNA was restored to its basal level. Interestingly, under mild hypothermia AQP4 mRNA expression transiently decreased and then increased about two-fold; while AQP9 mRNA expression decreased the same as at 37 degrees C. The changes in the expression of AQP4 and AQP9 proteins were confirmed by Western blot analysis. The restoration of the AQP4 and AQP5 expression at 32 degrees C from the hypoxia-induced decrease at 37 degrees C may play an important role in the reduction of brain edema under hypothermic conditions.

Circulatory collapse caused by unnoticed hypermagnesemia in a hospitalized patient

We report a case of hypermagnesemia in a hospitalized patient after prolonged laxative use; due to preexisting impaired consciousness and digestive problems, the hypermagnesemia was difficult to detect until it almost became fatal. A 64-year-old man who was a patient at another hospital for treatment of head injury and gastric ulcer had developed circulatory collapse and was transferred to our hospital. Hypermagnesemia (serum magnesium concentration 11.0 mg·dl−1) was thought to be the cause of the circulatory collapse and treatments were successful. A magnesium laxative had been administered for more than a month at the previous hospital, but the patients serum magnesium level was never measured. Care should be taken when a magnesium laxative is administered to patients who already have impaired consciousness and digestive problems that are early symptoms of hypermagnesemia.

Effects of sympathetic nerve blockades on low-frequency oscillations of human earlobe skin blood flow.

Earlobe skin blood flow measured by laser Doppler flowmetry often shows low-frequency oscillations with a frequency around 0.1 Hz. We evaluated the effects of different sympathetic blocking techniques on the oscillations. Power spectrum of 5-min time series of beat-to-beat peak earlobe skin blood flow showed a distinct spectral peak at a frequency around 0.1 Hz (mean +/- SD, 0.107+/-0.016 Hz). The power of the spectral peak measured as coefficient of component variance (CCV) was diminished with total spinal anesthesia (TSA, n = 4) and cervicothoracic epidural anesthesia (CTEA, n = 4; P<0.05 for both). The CCV was unchanged significantly with bilateral thoracic sympathetic ganglionic excision (TSGE, n = 5). Right stellate ganglion block (RSGB, n = 6) caused a trend towards an increase in the CCV on the right (blocked)-side (P = 0.072) but no change on the left (intact)-side. Cross-spectrum analysis revealed that the low-frequency oscillations were not coherent between the right- and left-side earlobes or with low-frequency oscillations in systolic blood pressure either before or after RSGB. TSA and CTEA are known to cause extensive sympathetic nerve blockade in a broad area, while TSGE and RSGB are known to cause local and partial sympathetic blockade. Our results suggest that although the low-frequency oscillations in earlobe skin blood flow may be mediated non-neurally, magnitude of the oscillations may be modified by sympathetic vasomotor tone.

Inadvertent intrathecal cannulation in an infant, demonstrated by three-dimensional computed tomography: a rare complication of internal jugular vein catheterization.

We describe a case of inadvertent intrathecal cannulation with a central venous catheter in an infant, confirmed by three-dimensional computed tomography, which clearly demonstrated the track of the catheter. We believe that this complication could have been related to two major factors: depth of needle insertion and penetration of the vein by a straight-tip guidewire. To avoid this complication, the depth of needle insertion must be carefully checked, a “J”-tipped rather than a straight-tipped guidewire should be used, and puncture should be guided by ultrasound.

Flexible, tapered-tip tube facilitates conventional orotracheal intubation by novice intubators

Orotracheal intubation is the standard technique for airway management, but several untoward airway complications are possible with this method. To avoid airway trauma caused by the tube tip during intubation, the Parker Flex-Tip tube (PFT), which has a flexible, tapered tip, was developed. It has been reported that the PFT facilitates fiberoptic orotracheal intubation and introducer-guided tracheal intubation. In this study, we compared the PFT to a standard endotracheal tube (SET), regarding the time of intubation during conventional orotracheal intubation and the incidence of postoperative sore throat and hoarseness. One hundred and thirty-four patients scheduled for elective anesthesia using orotracheal intubation were randomized to either the PFT or SET and 132 completed the study. The intubators were classified into three groups: staff anesthesiologists, inexperienced anesthesiologists, and anesthesia trainees. The tube was selected by another anesthesiologist and the time required for intubation was measured. PFT did not shorten the time required for intubation and did not reduce the incidence of sore throat and hoarseness. However, a detailed analysis revealed that the PFT decreased the time required for intubation in the anesthesia trainee group. The PFT may help novice intubators to conduct a smooth intubation.

Time progression from the patient's operating room entrance to incision: factors affecting anesthetic setup and surgical preparation times.

PurposeOwing to recent advances in surgical technology, substantial time is required for preparing surgical equipment before incision. The purpose of this study was to demonstrate the time progression from a patient’s operating room entrance to incision and to evaluate the duration of each anesthetic procedure and surgical preparation.MethodsWe marked the following seven points on the anesthetic chart: (1) entrance; (2) IV line placement; (3) preoxygenation; (4) intubation; (5) completion of patient positioning (Anesth-Set); (6) applying antiseptic solution; and (7) incision. Afterward, we analyzed the event time periods according to anesthetic procedure, patient position, surgical service, and surgical procedure (such as the utilization of endoscopy, navigation systems, and sentinel lymph node biopsy).ResultsOn average, it took approximately 3 min to start IV placement, 7 min until preoxygenation, 15 min until intubation, and 30 min until Anesth-Set. Epidural, arterial, and central venous catheterization required 15, 9, and 13 min, respectively. It took 20 min from Anesth-Set to incision, on average; 22, 4, and 5 min were required to prepare the navigation system, endoscope, and sentinel lymph node biopsy, respectively. In total, it took an average of 49.8 ± 17.1 min from entrance to incision, which was significantly longer (30.4 ± 8.8 min) than it took in 1985–1986.ConclusionThe mean time taken from the patient’s operating room entrance to incision is now significantly longer than before. This may be attributed, at least in part, to the preparation of equipment associated with new surgical technologies.

Anesthetic and airway management of general anesthesia in a patient with Meckel-Gruber syndrome

Meckel-Gruber syndrome, characterized by occipital encephalocele, microcephaly, polydactyly, cleft lip or palate, mandibular micrognathism, and anatomical abnormality of the larynx and tongue, along with other associated malformations, is in the list of diseases associated with difficult airway. However, there has been no report on the management of general anesthesia and airway management for such patients. A 2-year-old girl with Meckel-Gruber syndrome was scheduled for cardioplasty and gastrostomy for gastroesophageal reflux under general anesthesia. Preoperative examination revealed obesity, microgenia, dysspondylism, proteinuria, hypoplastic kidneys, and stenosis of the anal canal. Although we anticipated some difficulty with the intubation and prepared several alternative methods for intubation, such as a bronchofiberscope and a laryngeal mask airway, tracheal intubation was completed without difficulty using conventional laryngoscopy after inhalational induction with sevoflurane. Because most patients with this syndrome die before and shortly after delivery, those who survive to some age might have less severe deformities.