Immunohistochemical localization of enzymes that catalyze the long sequential pathways of lignin biosynthesis during differentiation of secondary xylem tissues of hybrid aspen (Populus sieboldii x Populus grandidentata).

We have investigated the spatial localization of enzymes that catalyze the sequential pathways of lignin biosynthesis in developing secondary xylem tissues of hybrid aspen (Populus sieboldii Miq. x Populus grandidentata Michx.) using immunohistochemical techniques. The enzymes phenylalanine ammonia-lyase, caffeic acid 3-O-methyltransferase and 4-coumarate:CoA ligase in the common phenylpropanoid pathway, cinnamyl-alcohol dehydrogenase (CAD) and peroxidase in the specific lignin pathway, 3-deoxy-D-arabino-heptulosonate 7-phosphate synthase (DAHPS) in the shikimate pathway and glutamine synthetase (GS) in the nitrogen reassimilation system were abundantly localized in the 6th to 9th wood fibers away from cambium; these wood fibers are likely undergoing the most intense lignification. Only weak immunolabeling of enzymes involved in the general phenylpropanoid and specific lignin pathways was detected in the cells near the cambium; lignification of these cells has likely been initiated after primary cell wall formation. In contrast, distinct localization of DAHPS and GS was observed around the cambium, which may be involved not only in lignin biosynthesis, but also in amino acid and protein synthesis, which are essential for cell survival. Our observations suggest that co-localization of enzymes related to the sequential shikimate, general phenylpropanoid and specific lignin branch pathways and to the nitrogen recycling system is associated with cell wall lignification of wood fibers during secondary xylem development.

Infusion rate of propofol and jugular venous oxygen saturation.

We compared jugular venous blood oxygen saturation (Sj(O) (2)) and the arterial-to-jugular-bulb venous oxygen content difference (AjD(O) (2)) between bispectral index (BIS) values of 40 and 60, adjusted by the infusion rate of propofol. Eighteen postoperative neurosurgical patients (Glasgow Coma Scale [GCS] scores, 11-15) were enrolled. Normocapnia, normothermia, and a mean arterial blood pressure greater than 70 mmHg were maintained. At BIS values of 40 and 60, hemoglobin, oxygen saturation, and the oxygen partial pressure of arterial and jugular venous blood were measured. Sj(O) (2) at BIS40 (58 +/- 9%) was significantly (P < 0.01) lower than that at BIS60 (63 +/- 10%), and AjD(O) (2) at BIS40 (6.3 +/- 1.5 ml.dl(-1)) was significantly (P < 0.01) higher than that at BIS60 (5.7 +/- 1.5 ml.dl(-1); mean +/- SD). At BIS40, status defined as Sj(O) (2) less than 50% was observed in 3 patients, while this status was observed in 1 patient at BIS60. In conclusion, in patients with postoperative neurosurgical surgery (GCS scores, 11-15), decreases of propofol infusion to adjust the BIS value from 40 to 60 increase the cerebral oxygen balance.

[Spinal anesthesia with isobaric 0.5% bupivacaine for lower limb surgery: effects of different volumes].

BACKGROUND: The effects of different volumes (2.4, 2.6, 2.8 and 3.0 ml) of isobaric 0.5% bupivacaine used for spinal anesthesia were compared in 206 patients scheduled for lower limb surgery. METHODS: The spinal anesthesia was performed with the patients in the lateral position and the isobaric 0.5% bupivacaine was injected intrathecally at the L3-4 interspace. RESULTS: The time to maximum cephalad spread of anesthesia (loss of cold sensation) varied between 25 and 40 min. A significant difference was found in cephalad spread between 2.4 ml group and 3.0 ml group (T11 vs T7), and between 2.6 ml group and 3.0 ml group (T11 vs T7). Severe hypotension did not occur during the study. CONCLUSIONS: Spinal anesthesia with 2.8 ml of isobaric 0.5% bupivacaine proved satisfactory for lower limb surgery.

[Transient complete atrioventricular block during renal transplantation].

A 25-year-old female underwent renal transplantation. The patient had no complication preoperatively except hypertension. Preoperative electrocardiogram revealed no abnormality. Anesthesia was maintained with sevoflurane. Donor kidney was perfused with University of Wisconsin (UW)'s solution (4 degrees C) after removal. Transient complete atrioventricular block appeared twice after reperfusion of the transplanted kidney. Adenosine in the UW's solution was considered the major cause of atrioventricular block in this patient. Attention must be paid to the occurrence of atrioventricular block and bradycardia shortly after reperfusion in the case where UW's solution was used for donor kidney perfusion.