Anesthetic management for a patient with severely obstructed upper airway undergoing CO2 laser resection of the tracheal tumor

A 76-year-old woman was scheduled to undergo a laser resection of the tracheal tumor which severely obstructed the upper airway. She had a past history of thoracic aortic aneurysm resection and myocardial infarction. After spraying the patient's oral cavity with 8% lidocaine, a laryngeal mask airway was inserted under spontaneous respiration. Tumor resection was successfully performed using CO2 laser through the laryngeal mask airway with the aid of low dose fentanyl under spontaneous respiration. Maintaining FIO2 at 0.5 could prevent hypoxemia. Although mild edema was observed in the larynx at the completion of the surgery, the patient achieved remarkable improvement in her breathing status. Consequently, she was able to undergo radiotherapy on the 5th postoperative day. This effectively reduced the tumor volume.     

Autologous serum eye drops for dry eye after LASIK

PURPOSE: To evaluate the efficacy of autologous serum eye drops for dry eye after LASIK in a prospective, randomized study. METHODS: Fifty-four eyes of 27 male patients who underwent LASIK were divided into two groups; patients who used autologous serum eye drops and those who used artificial tears postoperatively. Schirmer test with anesthesia, tear break-up time (BUT), and rose bengal and fluorescein staining for the ocular surface were prospectively compared between the groups. All values were also compared before and after surgery (at 1 week [except for Schirmer test], 1 month, 3 months, and 6 months) in each group. RESULTS: Tear BUT was greater in the autologous serum eye drops group than in the artificial tears group at 6 months postoperatively. Rose bengal score was lower in patients using autologous serum eye drops than in patients using artificial tears at 1 month and 3 months postoperatively. No significant difference was noted between patients using autologous serum eye drops and patients using artificial tears in the value of Schirmer test with anesthesia and fluorescein scores. In the autologous serum eye drops group, tear BUT was increased at 3 months after LASIK, rose bengal score was lower at 1 month and 3 months, and fluorescein score was lower at 1 month after LASIK compared to preoperative values, respectively. In the artificial tears group, all values (Schirmer test, tear BUT, rose bengal score, and fluorescein score) showed no differences between before and after LASIK. No differences were noted in the subjective scores for dryness between the autologous serum eye drops and artificial tears groups. CONCLUSIONS: The autologous serum eye drops group showed prolongation of the tear BUT and a reduction in rose bengal staining score.     

Local electrical stimulation: Effective needling points for suppressing jaw opening reflex in rat

Effects of electroacupuncture on the jaw opening reflex after tooth pulp stimulation were investigated in lightly anesthetized rats. Electroacupuncture stimulation (45 Hz, 5 msec) was delivered to 8 meridian points and 6 nonmeridian ones for 15 min so as to compare the degree of suppression elicited from each point. Significant suppressive effects on the reflex were observed in the cases of Yin-Hsiang, Ho-Ku and Shou-Sanli stimulation and these effects were antagonized by naloxone. However, stimulation of Hsia-Kuan, Chu-Chih, Neiting and Taichi, although these points were reported to suppress oro-facial or dental pain in man, scarcely produced suppressive effects. On the other hand, stimulation of some nonmeridian points produced moderate analgesic effects as gauged by the jaw opening reflex. The present study revealed that specificity of the meridian points is not absolute, but relative and that Yin-Hsiang, Ho-Ku and Shou-Sanli points were fairly effective in suppressing pulp-evoked jaw opening reflex in rat, which is presumably a noxious reflex. When the jaw opening reflex was evoked by non-pulpal stimulation, electroacupuncture was less effective on the reflex.     

Comparison of the relaxing effect of dopamine with that of adenosine, isoproterenol and acetylcholine in isolated canine coronary arteries.

Isolated canine coronary arteries were contracted with prostaglandin F2a and the relaxing effects of dopamine, adenosine, isoproterenol and acetylcholine were compared. Relaxation induced by dopamine in phenoxybenzamine-treated arteries was not significantly influenced by propranolol and atropine in concentrations sufficient to shift dose-respone curves of isoproterenol and acetylcholine, respectively, to the right. Dose-response curves of isoproterenol were shifted significantly to the left by 2 x 10(-5) M aminophylline. In contrast, the relaxing effect of adenosine was significantly attenuated by aminophylline (5 x 10(-6)-10(-4) M) in a dose-dependent manner. Kinetic analysis showed that aminophylline competitively antagonized the effect of adenosine, and the pA2 was 5.57. At these concentrations, aminophylline did not alter the relaxing action of dopamine and acetylcholine. It may be concluded that dopamine produces relaxation at a different site and with a different mechanism of action from those of isoproterenol, the effect of the latter being presumably mediated by cellular cyclic AMP, and that dopamine also does not share the site of action with adenosine and acetylcholine. It appears that receptive sites specific for adenosine are present in canine coronary arteries.     

Bulbar reticular neurons relaying somatosensory information to the mesencephalic parabrachial area of the cat

Somatosensory neurons projecting to the mesencephalic parabrachial area (MPBA), which is located ventral to the inferior colliculus and dorsal to the brachium conjunctivum, were recorded from the bulbar reticular formation of adult cats anesthetized with alpha-chloralose. The majority (41 of 50 neurons) were nociceptive-specific neurons responding only to noxious mechanical and/or thermal stimuli to the skin, cornea and/or oral mucosa. The size of their receptive fields was smaller than that of the intrinsic MPBA-neurons, but larger than that of the trigeminal sensory nucleus neurons. Twenty-three neurons received input from the tooth pulp nerve and 10 of 32 neurons tested responded to electrical stimulation of the vagal nerve. These results indicate that these bulbar reticular neurons receive noxious inputs and transmit them to the MPBA, which also receives input from spinal or trigeminal sensory nucleus neurons projecting directly to the MPBA.     

Morphology of central terminations of intra-axonally stained, low-threshold mechanoreceptive primary afferent fibers from oral mucosa and periodontium in the rat

Horseradish peroxidase (HRP) was injected intra-axonally into functionally identified primary afferent fibers within the rat spinal trigeminal tract in order to study the morphology of their central terminations. They were physiologically determined to be large, myelinated afferent fibers from periodontium or oral mucosa by means of electrical and mechanical stimulation of their receptive fields. Twenty-eight axons that innervated the periodontium of incisors and 21 axons that innervated the oral mucosa were stained for distances of 2-5 mm from the injection sites at the levels of the main sensory nucleus (Vms), spinal trigeminal nucleus and rostral cervical spinal cord. The collaterals of these primary afferent fibers formed terminal arbors in the medial or dorsomedial part of the Vms, and the oral and interpolar spinal trigeminal nuclei (Vo and Vi). In the caudal spinal trigeminal nucleus (Vc), the collaterals of one half of the periodontium afferent fibers terminated mainly in lamina V at the rostral and middle levels of Vc. On the other hand, the collaterals of the other half of the periodontium afferent fibers terminated mainly in lamina IV at the rostral level of Vc, and rostrally these terminal areas shifted to the most medial part of Vi. The collaterals of mucosa afferent fibers terminated in lamina V at the rostral level of Vc, and these terminal areas shifted gradually to laminae III and IV as the parent axons traveled more caudally. These shifts were staggered rostrocaudally according to the rostrocaudal locations of the receptive fields. The density of collaterals of periodontium afferent fibers in Vi was significantly larger than that of mucosa afferent fibers. The average size of the varicosities of periodontium afferent fibers was significantly larger than those of mucosa afferent fibers in Vo, Vi and Vc. The average number of varicosities belonging to single collaterals of slowly-adapting periodontium afferent fibers in Vi were significantly larger than those in Vo. In Vi, the average number of varicosities of single collaterals of slowly-adapting periodontium afferent fibers were significantly larger than those of rapidly-adapting periodontium afferent fibers.     

Age-related changes of serum apoprotein SASSAM, apoprotein A-I and low-density lipoprotein levels in senescence accelerated mouse (SAM)

Age-related changes of serum concentration of apo SASSAM, an apoprotein of high density lipoprotein (HDL) which cross-reacts with antiserum against murine senile amyloid fibril protein (ASSAM) were estimated in senescence accelerated mouse (SAM-P) and in senescence resistant series (SAM-R), as a control, using a single radial immunodiffusion technique. Serum concentrations of apo A-I, a major apoprotein of HDL, and low density lipoprotein (LDL) were also measured. In SAM-P (SAM-P/1 and SAM-P/2) with a high incidence of senile systemic amyloidosis, we observed age-associated decreases in serum apo SASSAM levels. The concentrations of apo SASSAM at 16 months of age were below 40% of the concentration at 2 months of age, regardless of the sex. In contrast with SAM-P, we observed no age-associated decrease of serum apo SASSAM levels in SAM-R (SAM-R/1 and SAM-R/2) with a low incidence of amyloidosis. Serum apo SASSAM concentration was higher in SAM-R/1 than in any other strain of mice observed. Serum apo A-I concentration was highly and significantly correlated with the serum concentration of apo SASSAM and decreased with advancing age in SAM-P but not in SAM-R. Age-related changes of LDL were not observed in any strain, but the concentration was lower in the females. In old SAM-P (16 months' old), the concentration of apo SASSAM decreased to one-third of that in the young SAM-P (4 months' old) and the serum concentrations of albumin and total protein did not decrease, compared with those in the young mice. All these findings taken together suggest that abnormality of metabolism in apo SASSAM, putative precursor of ASSAM, might occur in SAM-P.