Intravenous ketamine attenuates arterial pressure changes during the induction of anaesthesia with propofol

BACKGROUND AND OBJECTIVE

To investigate whether the administration of ketamine before induction with propofol produces a smaller decrease in arterial pressure.

METHODS

Twenty-two patients were assigned to one of two groups to receive either propofol with ketamine (n = 11) or propofol alone (n = 11, control). Anaesthesia was induced with 2 mg kg-1 propofol and 0.5 mg kg-1 ketamine or 2 mg kg-1 propofol alone. Ketamine was administered 1 min prior to induction with propofol. Immediately after induction with propofol, vecuronium (0.15 mg kg-1) was administered. Four minutes after administration of vecuronium, tracheal intubation was performed. Anaesthesia was maintained using sevoflurane (0.5%) in 66% nitrous oxide until 3 min after intubation. Systolic, diastolic and mean arterial pressure and heart rate were recorded on arrival, directly before induction with propofol, prior to tracheal intubation, immediately after intubation and at 3 min after intubation.

RESULTS AND CONCLUSIONS

Administration of ketamine before induction with propofol preserved haemodynamic stability compared with induction with propofol alone.

[Anesthesia for emergency surgery in a patient with Shy-Drager syndrome]

A 53-year-old man with Shy-Drager syndrome underwent emergency surgery for the resection of the larynx under general anesthesia. Anesthesia was induced with fentanyl 0.1 mg and thiopental 100 mg, and endotracheal intubation was facilitated with vecuronium 8 mg. The onset of action of vecuronium was very slow. Anesthesia was maintained with about 1% of sevoflurane, with nitrous oxide 3 l.min-1 in oxygen 3 l.min-1. Norepinephrine was effective for hypotension while dopamine was not. He was extubated on the first postoperative day without any complications. The effects of vecuronium, norepinephrine, and dopamine might be changed in the patient with Shy-Drager syndrome.

Immunotherapy of bladder cancer using autologous dendritic cells pulsed with human lymphocyte antigen-A24-specific MAGE-3 peptide

Recent investigations have demonstrated the efficacy of autologous dendritic cells (DCs) pulsed with tumor antigens to generate tumor-specific CTLs against cancer cells. Melanoma antigens (MAGE) are a family of tumor-specific antigens shown to be expressed in various tumors, including bladder cancers and melanoma, but not in normal tissues except for the testis. Because invasive bladder cancers are frequently reported to express MAGE, we explored the possibility of establishing a new immunotherapeutic modality against advanced bladder cancer using autologous DCs pulsed with one of the MAGE-3 epitope peptides (IMPKAGLLI), which is synthesized to bind specifically to HLA-A24. A MAGE-3-expressing bladder cancer cell line, FY, was newly established from a lymph node metastasis of bladder cancer in a HLA-A24+ patient. The FY cell-specific CTL response was significantly higher when CTL was induced by autologous DCs pulsed with IMPKAGLLI than by FY cells alone or by nonpulsed DCs in vitro. A total of four HLA-A24+ patients with advanced MAGE-3+ bladder cancers were treated with s.c. injections of autologous DCs pulsed with IMPKAGLLI every 2 weeks for a minimum of 6 and a maximum of 18 times. Three of four patients showed significant reductions in the size of lymph node metastases and/or liver metastasis. No significant untoward side effects were noted in these patients. This study indicated that, at sometime in the future, tumor-specific DC-based cancer immunotherapy may be useful as an additional treatment modality against advanced bladder cancer.

Continuous nicardipine infusion to control blood pressure after evacuation of acute cerebral hemorrhage

PURPOSE

To explore the long-term effects of the calcium antagonist, nicardipine, on cerebral hemodynamics in patients with acute cerebral hemorrhage, we investigated the effects of nicardipine infusion on intracranial pressure (ICP), middle cerebral arterial blood flow velocity (Vmca) , and computed tomographical (CT) findings of bleeding and edema.

METHODS

Twenty-two patients with acute cerebral hemorrhage were infused with nicardipine for > 72 hr to decrease blood pressure. Blood pressure, heart rate, conscious level, Vmca, pulsatility index (PI, using transcranial Doppler), ICP, cerebral perfusion pressure (CPP) and platelet counts were monitored. CT examination was also performed to detect the changes of bleeding (hematoma) and/or brain edema.

RESULTS

Blood pressure decreased (20 to 30% from control, P < 0.05) without any changes in heart rate. Platelet count did not change neither did Vmca and PI change on either the intact or injured side. The ICP decreased 24 hr after the end of infusion from 30 +/- 12 mmHg to 20 +/- 9 mmHg (P = 0.036) but was still higher than normal. The CPP decreased at 24 hr (75 +/- 14 mmHg, P = 0.026) and 72 hr (73 +/- 15 mmHg, P = 0.024) from the baseline (99 +/- 17 mmHg). Conscious level improved but not significantly and CT findings did not show any exacerbation in bleeding or edema.

CONCLUSION

In patients with acute cerebral hemorrhage, nicardipine infusion to decrease blood pressure by 20 to 30% had no effect on Vmca, ICP, cerebral bleeding and edema, but decreased CPP.

Parapelvic neurofibroma of the kidney

We report the first case of neurofibroma causing obstruction by external compression of the upper renal pelvis. A 33-year-old woman reported a 1-year history of dull lumbar pain on the right side. A right renal parapelvic cyst was suspected. The patient underwent retroperitoneoscopic exploration. The right renal parapelvic lesion was identified as a soft tissue tumor. The tumor was removed with a retroperitoneoscopic procedure. Histopathological findings revealed neurofibroma.

Profiles of cytokine expression in radicular cyst-lining epithelium examined by RT-PCR

Levels of messenger RNA (mRNA) extracted from five samples of radicular cyst-lining epithelium were analyzed for cytokines, growth factors and epithelial cell growth-related receptors by RT-PCR. All five samples expressed IL-1alpha, -1beta, IL-6, IL-8, IL-11, TGF-beta1, PDGF-A and aFGF, and receptors for EGF (c-erbB), KGF, HGF (c-met) and IL-6. Some of the specimens expressed MIP-1alpha, RANTES, GM-CSF, M-CSF, TNF-alpha, PDGF-B and bFGF, but no expression of IL-2, IL-4, IFN-gamma, IGF-I, EGF and KGF was detected. These results indicate that radicular cyst-lining epithelium, which is considered to be identical to the cell rests of Malassez, may play a role in periodontal pocket formation or apical cyst formation by interaction with surrounding connective tissue or hematopoietic cells through the expression of various cytokines.

Trifluoromethanesulfonic anhydride-promoted alpha-bromination of ketones with grignard reagent or magnesium bromide

The direct alpha-bromination of various ketones using trifluoromethanesulfonic anhydride and Grignard reagent or magnesium bromide in ether gave the corresponding alpha-bromo ketones in moderate to good yields under mild reaction conditions.

The importance of laminin 5 in the dermal-epidermal basement membrane

The skin consists of two main layers, epidermis and dermis, separated by the basement membrane. Epidermal-dermal communication through the basement membrane is important for skin homeostasis. The basement membrane contains specialized structures, called the anchoring complex, which ensure the stability of connection and communication between these two tissue compartments. The proteins within the anchoring complex provide links to both the intracellular cytoskeletal keratins in keratinocytes and connective tissue proteins of the dermis. One of the key components of the complex is laminin 5, which is essential to epidermal cell attachment. The biological function of laminin 5 has been investigated by using a skin equivalent model in vitro and during keratinocyte sheet grafting in vivo. As a major link between the epidermal basal cells and the papillary dermis, laminin 5 initiates hemidesmosome formation and provides stable attachment of the epidermis to the dermis. Laminin 5 also accelerates the assembly of basement membranes and may enhance the recovery of damaged skin. An intact basement membrane at the epidermal-dermal junction is essential to stability of the skin.

5-day vs. 7-day triple therapy with rabeprazole, clarithromycin and amoxicillin for Helicobacter pylori eradication

AIM

To determine whether a 5-day regimen with rabeprazole, clarithromycin and amoxicillin (RCA) was as effective as a 7-day regimen.

METHODS

A total of 139 H. pylori-infected patients were randomized to receive either a 5-day or 7-day course of rabeprazole 10 mg b.d., clarithromycin 400 mg b.d. and amoxicillin 750 mg b.d. Eradication was assessed by CLO test, histology and 13C-urea breath test.

RESULTS

On the intention-to-treat basis, eradication rates were 66% (46 out of 70) and 84% (58 out of 69) for the 5- and 7-day regimens, respectively (P < 0.05). Using per protocol analysis, eradication rates were 70% (46 out of 66) and 91% (58 out of 64) for the 5- and 7-day regimens, respectively (P < 0.01). Adverse events, which were observed in 14 patients from each group, caused discontinuation of treatment in only two patients, resulting in excellent compliance.

CONCLUSIONS

Our 5-day regimen of RCA yielded inferior results, whereas the 7-day regimen achieved an eradication rate exceeding 90% on the per protocol basis. Therefore, treatment regimens of less than 7 days for proton pump inhibitor-clarithromycin-amoxicillin therapies cannot be recommended.

Nicardipine did not activate renin-angiotensin-aldosterone system during isoflurane or sevoflurane anesthesia

PURPOSE

To investigate the changes of renin-angiotensin-aldosterone system by nicardipine administration during isoflurane or sevoflurane anesthesia.

METHODS

Twenty patients aged 40 to 70 yr for elective neurosurgery were studied. Anesthesia was induced with thiopental, midazolam and fentanyl and was maintained with nitrous oxide in oxygen and isoflurane or sevoflurane. When blood pressure was constant, 0.017 mg x kg(-1) nicardipine was administered as a bolus. Blood pressure, heart rate, and plasma concentrations of nicardipine, angiotensin I and II, aldosterone and renin activity were measured for 30 min after nicardipine administration.

RESULTS

Blood pressure decreased for 30 min after nicardipine administration in both groups with lower values during sevoflurane anesthesia. Heart rate increased only in the isoflurane group. Plasma nicardipine concentrations did not differ between isoflurane and sevoflurane groups. Plasma renin activity and concentrations of angiotensin II and aldosterone did not change in either groups and there were no differences between groups. Plasma concentration of angiotensin I increased at 20 and 30 min after nicardipine administration in the isoflurane group but not in the sevoflurane group.

CONCLUSION

The activity of renin-angiotensin-aldosterone system did not increase by a single dose administration of nicardipine in isoflurane or sevoflurane anesthesia.

[Airway obstruction after general anesthesia in a patient with the first and second branchial arch syndrome]

A 20-year-old female with the first and second branchial arch syndrome underwent plastic surgery. Due to her mandibular hypoplasia and trismus, tracheal intubation was difficult even with a broncho-fiberscope. Fentanyl 100 micrograms was used for nasal intubation. Anesthesia was maintained with nitrous oxide (4 l.min-1), oxygen (2 l.min-1) and sevoflurane (0.5-3%). There were no troubles during surgery. The trachea was extubated after recovery of consciousness and spontaneous respiration. Five minutes after extubation, airway was obstructed suddenly after massive nasal bleeding. Sudden massive bleeding might have caused airway obstruction. Emergency insertion of an 18 G needle followed by Mini-trach II into the trachea through the cryothyroidal ligament improved her respiratory condition. The case suggests that preparing the instrument for the emergency cryothyroidal ligament puncture (for instance Mini-trach II) is useful for a patient with a risk of bleeding in the airway and with difficult intubation.

A traumatic asphyxia in a child

PURPOSE

Traumatic asphyxia in a child is rare and the pathophysiology is different from that occurring in an adult. We report a case of traumatic asphyxia in a child who recovered without specific treatment, even though chest and abdominal compression was severe.

CLINICAL FEATURES

A three-year-old boy (14.2 kg) was run over by the rear wheel of a Jeep. He was under the tire for about three minutes and then was transferred to our hospital. When he arrived, he was lethargic with Glasgow Coma Scale of E3V4M6 (coma score of 13). He was cyanotic in his face and had a tire mark from the left shoulder to the right abdomen, petechiae on the head, face, conjunctiva and chest, oral bleeding, and facial edema. Serum concentrations of liver enzymes were increased and microhematuria was detected. However, no injuries were seen in the brain, eye, chest, or abdomen. Cyanosis disappeared in a few hours. Facial and thoracic petechiae disappeared in three days and that of the conjunctiva in five days. He was discharged from hospital on the 13th day without any disturbances.

CONCLUSION

We present a three-year-old boy with traumatic asphyxia. He had no complications although he received severe thoraco-abdominal compression by a Jeep.

[General anesthesia for a patient on hemodialysis with arteriosclerosis obliterans]

A 48-year-old man with arteriosclerosis obliterans was scheduled for axillofemoral bypass. He had chronic renal failure and on hemodialysis (HD) for 22 years. On the morning of the day of surgery he received HD and two hours later anesthesia was induced with fentanyl 300 micrograms and midazolam 6 mg, and maintained with fentanyl, nitrous oxide and intermittent isoflurane. The common carotid artery was cannulated to measure arterial blood pressure because arteries in extremities were not available. Internal jugular vein at the other side of the arterial catheterization was cannulated to measure central venous pressure. Crystalloid and blood transfusion was performed to adjust hemodynamics and central venous pressure. Hemodynamics were stable during surgery and no complication occurred regarding the common carotid arterial line. The common carotid artery was useful for blood pressure monitoring in a patient whose extremities were not available. Midazolam and fentanyl could give stable hemodynamics to a patient with arteriosclerosis obliterans and chronic renal failure.

Shrinkage in the horizontal dimensions of the vulva (vulvar shrinkage) as an indicator of standing heat in the beagle

During the proestrous and estrous periods in 12 beagles, the following parameters were measured daily: the horizontal dimensions of the vulva, vaginal cytology, and serum luteinizing hormone (LH) and progesterone concentrations. Measurements of serum LH concentrations allowed for the identification of the LH surge and the optimal time for artificial insemination (AI). Nine out of the 12 beagles became pregnant through AI and completed a gestation. Shrinkage in the horizontal dimensions of the vulva (i.e., vulvar shrinkage) was primarily observed prior and subsequent to the LH surge. In six of the nine (66.7%) beagles that became pregnant, vulvar shrinkage was observed on the days in which the LH surge was confirmed, and the rate of vulvar shrinkage tended to be greater at higher serum LH concentrations. Further vulvar shrinkage was identified in all nine beagles within two days of the LH surge. An increase in the serum progesterone concentration was observed after the LH surge in each of the beagles that became pregnant, together with clinical signs of estrous behavior (i.e., standing heat) as well as a change in vulva condition from swollen to soft. This demonstrates that vulvar shrinkage is induced in response to the onset of the LH surge and that the LH surge can be predicted through the measurement of the horizontal dimensions of the vulva, vaginal cytology, and the assessment of serum progesterone concentrations in beagles.

Prognostic value of alkaline phosphatase flare in patients with metastatic prostate cancer treated with endocrine therapy

OBJECTIVES

To assess the prognostic significance of alkaline phosphatase (ALP) flare in 114 patients with metastatic prostate cancer treated with endocrine therapy.

METHODS

ALP flare was defined as a transient increase of the serum ALP level to 120% or more of the pretreatment value after the initiation of endocrine therapy, followed by a subsequent decrease.

RESULTS

Univariate analysis demonstrated that patients with poorly differentiated adenocarcinoma, an extent of disease of 2 or greater, a serum ALP level above twice the upper limit of normal, a serum prostate-specific antigen level greater than 100 ng/mL, an ALP flare, and a hemoglobin level of 12 g/dL or less had a significantly lower survival rate than their respective counterparts. Multivariate Cox's proportional hazards model analysis demonstrated that tumor histologic features and ALP flare were significant prognostic indicators for survival.

CONCLUSIONS

The results of the present study suggest that the tumor histologic features and the ALP flare are significant prognostic indicators for survival in patients with metastatic prostate cancer treated with endocrine therapy.

Implication of NF-kappaB in Helicobacter pylori-associated gastritis

OBJECTIVE

Transcription factor NF-kappaB plays a pivotal role in inflammatory responses by up-regulating mRNA expression of bioactive molecules such as chemokines and adhesion molecules. The present study was designed to elucidate the implication of NF-kappaB in Helicobacter pylori-associated gastritis (HAG).

METHODS

We examined 41 patients with HAG and 18 H. pylori-negative control subjects. Expression of activated NF-kappaB was studied in situ by immunohistochemistry using alpha-p65 mouse monoclonal antibody (alpha-p65 mAb), which recognizes activated NF-kappaB. To identify the cell types in which NF-kappaB was activated, we performed immunohistochemical analysis using antibodies against vascular endothelial cells, macrophages, and B and T lymphocytes. We also examined the colocalization of activated NF-kappaB with the of intercellular expression adhesion molecule-1 (ICAM-1) on endothelial cells. We measured the levels of NF-kappaB-dependent chemokines including interleukin-8 (IL-8) and monocyte chemoattractant protein-1 (MCP-1), regulated on activation normal T-cell expressed and secreted (RANTES) and macrophage inflammatory protein-1alpha (MIP-1alpha) in antral mucosa by ELISA (ELISA).

RESULTS

Activated NF-kappaB was detected in the nuclei of epithelial cells in antral mucosa, especially of patients with HAG. NF-kappaB positivity index (NF-kappaB PI), representing the percentages of epithelial cells with positive nuclear staining for activated NF-kappaB, was significantly higher in patients with HAG than in H. pylori-negative controls. NF-kappaB PI correlated significantly with histological scores of gastritis. Moreover, activated NF-kappaB was identified in the nuclei of vascular endothelial cells, macrophages, and B lymphocytes within the lamina propria in HAG. Colocalization of activated NF-kappaB with ICAM-1 expression in the same endothelial cells was demonstrated. The IL-8 levels significantly correlated with the NF-kappaB PI.

CONCLUSIONS

In addition to epithelial cells, macrophages, vascular endothelial cells, and B lymphocytes contained activated NF-kappaB. In these cells, activated NF-kappaB may be involved in the inflammation process in HAG through the up-regulation of chemokines or adhesion molecules.

Distribution and isoform characterization of type XII collagen in bovine cornea

Streptavidin peroxidase immunohistochemistry and immunoelectron microscopy were used to determine the localization of type XII collagen in sections from bovine corneas. Type XII collagen extracted from bovine cornea and skin was assayed by Western blotting. Immunohistochemical experiments showed that type XII collagen was restricted to the corneal stroma; it was not present in corneal epithelium, epithelial basement membrane, Descemet's membrane or endothelium. Type XII collagen was distributed throughout the corneal stroma, and it was prominently localized at the superficial stroma. Immunoelectron-microscopic examination demonstrated that type XII collagen was regularly found along the surface of banded collagen fibrils with a periodic distribution. By Western blot analysis, we observed that extracts from bovine cornea contained both the long and short isoforms of type XII collagen, whereas extracts from bovine skin contained only the short isoform. The homogeneous distribution and/or presence of the long isoform of type XII collagen may be related to the characteristically regular arrangement of collagen fibrils and thereby the transparency of corneal tissue.

[Anesthesia for a cervical myelopathy patient with tracheal stenosis]

A 71-year-old male with cervical myelopathy was scheduled for C 3-7 laminectomy. Once he had been rejected of general anesthesia in other hospital because of his tracheal stenosis. The diameter of the narrowest part of his trachea was 5 mm probably resulting from tracheostomy at 2 years of age. His cervical myelopathy seemed to be no problem for anesthesia induction because he had no problems in his neck movement and opening mouth. We evaluated his tracheal stenosis carefully using bronchofiberscopy, chest X-ray, computed tomography and pulmonary function tests. After intravenous fentanyl 100 micrograms and midazolam 2.5 mg, it was impossible to ventilate the patient. Therefore, tracheal intubation was performed immediately after lidocaine administration into the trachea. During surgery, tracheal tube dilated the narrowed portion. After surgery, the tracheal tube was removed under bronchofiberscopic observation without any problems. Tracheal stenosis was observed by chest X-ray after surgery, but he had no complaints.

The effects of epidural bupivacaine, morphine, and their combination on thermal nociception with different stimulus intensity in rats

The analgesic effect of drugs depends on the stimulus intensity as well as the potency of the drugs. We investigated the effects of stimulus intensity on antinociceptive potencies of epidural bupivacaine + morphine. Sprague-Dawley rats implanted with chronic lumbar epidural catheters were tested for paw withdrawal response to thermal stimulation after the epidural injection of bupivacaine, morphine, or bupivacaine + morphine. Two stimulation currents were used, 5.1 and 4.6 A, to provide baseline response latency of approximately 5.0 s (high intensity) and 10.0 s (low intensity), respectively. Increasing the dose of epidural morphine in a dose range that had a maximum effect on low-intensity stimulation was not effective for high-intensity stimulation. Bupivacaine, which alone had no effect, potentiated the antinociceptive effect of epidural morphine at both high- and low-intensity stimuli similarly. We concluded that bupivacaine potentiated the analgesic effect of epidural morphine at both weak and strong nociceptive stimuli similarly, whereas increasing the dose of epidural morphine was not as effective for strong nociceptive stimulation. Therefore, adding bupivacaine might be more effective than increasing the dose of epidural morphine for intense nociception.

IMPLICATIONS

When patients have severe pain even when receiving epidural morphine, adding bupivacaine might be more effective than increasing the dose of epidural morphine.

Free hemoglobin concentrations in patients receiving massive blood transfusion during emergency surgery for trauma

PURPOSE

To determine free hemoglobin concentration in patients who received massive blood transfusion during emergency surgery for trauma with consideration of the storage of the transfused blood.

METHODS

Fifteen patients undergoing emergency surgery for multiple trauma and who received blood transfusion of more than 5000 mL were studied. Transfusion of the stored whole blood in citrate-phosphate glucose solution using a micropore filter was started before surgery. Serum concentrations of hemoglobin (total:THb and free:fHb) and total haptoglobin (THp) were measured until 5,000 mL of blood had been transfused. Serum free haptoglobin (fHp) concentration was calculated. The correlation between the changes in hemoglobin or haptoglobin concentrations and total storage days of the transfused blood was analyzed by a simple regression analysis.

RESULTS

Free hemoglobin was detected after 2,000 mL transfusion. The THp and fHp decreased after 1,000 mL transfusion. Total storage time (days) of transfused blood had correlated with the changes of THp (P < 0.0001) and fHp (P = 0.0027) but not with the changes of THb (P = 0.984) and fHb (P = 0.834).

CONCLUSION

After blood transfusion during surgery for trauma, serum haptoglobin concentration decreased with transfusion of > or = 1,000 mL of whole blood with mean storage time of 12.2 dy. Free hemoglobin was detected after 2,000 mL transfusion when THp decreased to 1,000 mgxL(-1). Serum haptoglobin concentrations correlated negatively with storage time (days) of transfused blood.

A chromosomal locus encoding a phosphoserine phosphatase- and a truncated MinD-like protein affects differentiation in Streptomyces azureus ATCC14921

We isolated BalA1, a representative transformant of thiostrepton-producing strain Streptomyces azureus ATCC14921, which carries an approximately 2.5-kb chromosomal DNA fragment on a high-copy-number plasmid. While strain BalA1 formed little aerial hyphae, its morphological defect was restored by cultivation with S. azureus, S. laurentii, etc. Strain BalA1 strongly inhibited the growth of Bacillus subtilis more than its parent strain, and also inhibited the development of its parent and some Streptomyces strains with thiostrepton resistance. Furthermore, it induced Streptomyces coelicolor A3(2) to produce undecylprodigiosin, at an early stage of growth. The 2.5-kb fragment contained two orfs, orf1 and truncated orf2. The deduced products were somewhat similar to phosphoserine phosphatase-like protein and the N-terminal region of MinD-like protein, respectively. The individual function of orf1 or the function of both orf1 and truncated orf2 seems to induce particular phenotypes or properties in strain BalA1.

[Hoarseness after endotracheal intubation caused by submucosal hemorrage of the vocal cord and recurrent nerve palsy]

Hoarseness often follows endotracheal intubation. A 58 year old man suffered from hoarseness due to recurrent nerve palsy and submucosal hemorrhage of the right vocal cord after general anesthesia. He was scheduled for resection of chronic pyoderma of the buttocks and atheroma of the right retroauricular region. Anesthesia was induced with thiopental 300 mg and endotracheal intubation was facilitated with vecuronium 6 mg. A spiral tube with 8 mm of inner diameter (Mallinckrodt Medical) was inserted with no problems. The tube was fixed at left side of the mouth. The cuff was inflated with air but the cuff pressure was not monitored. Anesthesia was maintained with sevoflurane (1-3%) and 67% N2O in 33% O2. Respiration was controlled mechanically. The patient was turned to the prone position and his head was turned to the right. The duration of surgery was one hour and forty minutes. Extubation of the tube involved no problems. He complained of hoarseness after surgery. Right recurrent nerve palsy and submucosal hematoma were observed. Without any treatment, hematoma disappeared in 70 days and hoarseness in 183 days. These hematoma and recurrent nerve palsy might be due to the compression of the vocal cord and recurrent nerve by tracheal tube and traction of the recurrent nerve by rotation of the neck.

Müller cells in the preconditioned retinal ischemic injury rat

The role of Müller cells in the preconditioned retinal ischemic injury rat was investigated. In anesthetized Sprague Dawley rats, retinal ischemia for 5 minutes constituted the preconditioning stimulus for the left eye. After 24 hours, both eyes were clamped for 60 minutes. In 30, 60, 90, and 120, minutes and 1 day, 3 days, and 7 days after ischemia, electroretinograms were recorded, and the eyeballs were enucleated. After fixation with 4% paraformaldehyde, the avidin-biotin-peroxidase technique was applied to show glutamine synthetase (GS) and glial fibrillary acidic protein (GFAP). Furthermore, for the solubilized retinas, Western blot analysis and enzyme-linked immunosorbent assay were performed to detect GS and GFAP in the extracts. Preconditioning performed 24 hours before ischemia significantly improved the recovery of the a-, and b-waves 1 day after 60 minute ischemia. In the 30, 60, 90, and 120 minutes after ischemia, the recovery of the a-wave only was observed. There was a nonsignificant trend toward greater recovery in the first 120 minutes after 60 minute ischemia, especially in the b-wave. GS immunoreactivity had no significant difference between non-preconditioned and preconditioned groups 30, 60, 90, and 120 minutes after ischemia. In 1 day after ischemia, GS immunoreactivity decreased in both groups. In 3 and 7 days after ischemia, GS immunoreactivity recovered only in the preconditioned group. The retinas at 3 and 7 days after 1 hour of ischemia showed increased GFAP immunoreactivity in the non-preconditioned group. In the preconditioned group, only slight GFAP immunoreactivity was observed. These results suggested that the mechanism of preconditioned retinal ischemia may be related to Müller cells in the retina.

The effects of intrathecal morphine encapsulated in L- and D-dipalmitoylphosphatidyl choline liposomes on acute nociception in rats

Liposomes can serve as a sustained-release carrier system, permitting the spinal delivery of large opioid doses restricting the dose for acute systemic uptake. We evaluated the antinociceptive effects of morphine encapsulated in liposomes of two isomeric phospholipids, L-dipalmitoylphosphatidyl choline (L-DPPC) and D-dipalmitoylphosphatidyl choline (D-DPPC), in comparison with morphine in saline. Sprague-Dawley rats with chronic lumbar intrathecal catheters were tested for their acute nociceptive response using a hindpaw thermal escape test. Their general behavior, motor function, pinna reflex, and corneal reflex were also examined. The duration of antinociception was longer in both liposomal morphine groups than in the free morphine group. The peak antinociceptive effects were observed within 30 min after intrathecal morphine, L-DPPC or D-DPPC morphine injection. The rank order of the area under the effect-time curve for antinociception was L-DPPC morphine > D-DPPC morphine > morphine. The 50% effective dose was: 2.7 microg (morphine), 4.6 microg (L-DPPC morphine), and 6.4 microg (D-DPPC morphine). D-DPPC morphine had less side effects for a given antinociceptive AUC than morphine. In conclusion, L-DPPC and D-DPPC liposome encapsulation of morphine prolonged the antinociceptive effect on acute thermal stimulation and could decrease side effects, compared with morphine alone.

IMPLICATIONS

Two isomers of liposome (L-dipalmitoylphosphatidyl choline and D-dipalmitoylphosphatidyl choline) encapsulation of morphine prolonged the analgesic effect on acute thermal-induced pain when administered intrathecally and could decrease side effects, compared with morphine alone.