Practical use of the central venous access port for contrast-enhanced CT: comparison with peripheral intravenous access regarding enhancement and safety

AIM

To evaluate the efficacy of using the central venous (CV) port compared with peripheral intravenous access for contrast-material injection for contrast enhancement during the portal venous phase.

MATERIALS AND METHODS

Patients were divided into three groups: CV delay, CV routine, and peripheral access (PA) groups. Patients in the CV delay group underwent injection in the arm-down position with an additional delay, while those in the CV routine and PA groups underwent injections with the routine injection protocol for portal venous phase imaging. Contrast enhancement was evaluated by measuring the mean radiodensity (Hounsfield units) values for the aortic arch, abdominal aorta, inferior vena cava, portal vein, and spleen. The peak injection pressure was recorded and compared among the three groups.

RESULTS

No complications related to power injection were observed during 119 contrast-material injections performed using the CV port device. The CV delay group showed significantly lower radiodensity values than the PA group (165.7 ± 20.1 versus 181 ± 19 HU [p<0.01] for the portal vein); however, no significant differences in mean radiodensity values were observed between the CV routine and PA groups (p>0.05). The median peak injection pressure was 73.5, 67, and 47 psi in the CV delay, CV routine, and PA groups, respectively (p<0.01).

CONCLUSION

The CV port can be used for safe contrast-material injection while maintaining contrast enhancement on portal venous phase comparable to that achieved with peripheral intravenous access.

Therapeutic intervention based on gene sequencing analysis of microbial 16S ribosomal RNA of the intrauterine microbiome improves pregnancy outcomes in IVF patients: a prospective cohort study

PURPOSE

A Lactobacillus-dominated microbiota in the endometrium was reported to be associated with favorable reproductive outcomes. We investigated in this study whether 16S ribosomal RNA (rRNA) gene sequencing analysis of the uterine microbiome improves pregnancy outcomes.

METHODS

This prospective cohort study recruited a total of 195 women with recurrent implantation failure (RIF) between March 2019 and April 2021 in our fertility center. Analysis of the endometrial microbiota by 16S rRNA gene sequencing was suggested for all patients who had three or more failed embryo transfers (ETs). One hundred and thirty-one patients underwent microbial 16S rRNA gene sequencing (study group) before additional transfers, while 64 patients proceeded to ET without that analysis (control group). The primary outcome was to compare the cumulative clinical pregnancy rate of two additional ETs.

MAIN RESULTS

An endometrial microbiota considered abnormal was detected in 30 patients (22.9%). All but one of these 30 patients received antibiotics according to the bacterial genus detected in their sample, followed by treatment with probiotics. As a result, the cumulative clinical pregnancy rate (study group: 64.5% vs. control group: 33.3%, p = 0.005) and the ongoing pregnancy rate (study group: 48.9% vs. control group: 32.8%, p = 0.028) were significantly increased in the study group compared to the control group.

CONCLUSION

Personalized treatment recommendations based on the microbial 16S rRNA gene sequencing of the uterine microbiota can improve IVF outcomes of patients with RIF.

TRIAL REGISTRATION

The University Hospital Medical Information Network (UMIN) Clinical Trial Registry: UMIN000036050 (date of registration: March 1, 2019).

P–763 Neonatal outcomes of the first 65 infants delivered after IVF treatment with progestin-primed ovarian stimulation using dienogest in patients with endometriosis

Study question

What is the perinatal outcome of pregnancies resulting from a controlled ovarian hyperstimulation (COH) regimen of progestin-primed ovarian stimulation (PPOS) protocol using dienogest (DNG) in patients with endometriosis?

Summary answer

No difference in mean birth weight, however preterm and low birth weight babies are significantly more in the group treated with PPOS using DNG.

What is known already

Dienogest is an oral progestin effective for the treatment of endometriosis, such as reduction of endometrial lesion and control of pain intensity with safety profile and good tolerability. We reported for the first time in the world that DNG was better than dydrogesterone (DYG) for PPOS in terms of the mature oocytes rate and the fertilization rate in patients with endometriosis. Although there have been several reports of infants born with PPOS using DYG, it is essential to report on the perinatal outcome of embryos transferred after treatment with PPOS using DNG from now on. Study design, size, duration: We prospectively investigated the perinatal outcomes of 65 newborns which were the result of using a new COH regimen; PPOS with DNG. The results were compared with perinatal outcome data of babies born between 2018 and 2020 to 815 patients who underwent assisted reproductive technology (ART) treatment at our fertility center. As for the congenital malformation rate, the data was also compared with the 2017 Japanese data bank of babies born after ART treatment.

Participants/materials, setting, methods

We studied the perinatal data of all babies born after transfer of frozen embryos acquired by COH using PPOS protocol with DNG. The rate of maternal complications during pregnancy, pregnancy duration, birth weight, congenital malformations and method of delivery were investigated. We compared the perinatal outcomes of infants born after in vitro fertilization (IVF) and frozen embryo transfer at our center during the same period.

Main results and the role of chance

Perinatal data of 65 babies (study group) were compared with the perinatal data of 840 babies born after IVF at our center, and 47807 babies born after ART in Japan, 2017. We found 3 twin and 59 singleton pregnancies in the study group, compared to 23 twins, 1 triplet and 791 singleton pregnancies during the same period at our center. Considering singletons, there was no difference in mean birthweight (study group; 2893.2±652g vs. total at our center; 3001.2±425g, respectively, p = 0.102). Preterm births (&lt;37 weeks) were significantly more frequent in the PPOS using DNG treatment group than in total at our center (19.2% vs. 9.7%, p = 0.016). The percentage of infants with a birth weight &lt; 2.5 kg was also significantly higher in the PPOS treatment group compared to the total at our center (22.6% vs.11.9%, p = 0.015). The Caesarean section rate was 53.2% in the study group vs. 47.1% control group of our center respectively (p = 0.353). One babies in the study group had malformations in the ocular region. There was no significant difference in congenital malformations between the study group and ART data bank in Japan, 2017 (OR 0.67, 95% CI 0.093: 4.836).

Limitations, reasons for caution

The number of babies is still low, further prospective studies including larger populations are needed to confirm the efficacy of PPOS protocol with DNG.

Wider implications of the findings: This is the first report on the perinatal outcome of babies born by a new COH method using PPOS with DNG, which is a combination of endometriosis treatment and COH for IVF. The association of endometriosis with preterm birth and low birth weight needs to be further investigated.

Trial registration number

UMIN000031111

New treatment strategy for endometriosis using progestin-primed ovarian stimulation with dienogest: A prospective cohort study, comparison of dienogest versus dydrogesterone

Dienogest (DNG) is an oral progestin effective for the treatment of symptomatic endometriosis, such as reduction of endometrial lesion and control of pain intensity. Progestin-primed ovarian stimulation (PPOS) is a new controlled ovarian hyperstimulation (COH) regimen, and several reports have shown that dydrogesterone (DYG) is an appropriate progestin for PPOS. The purpose of this study was to evaluate the efficacy of DNG in patients undergoing PPOS during COH in comparison with DYG. This was a prospective, cohort, parallel-group, non-inferiority trial of 150 women with endometriosis undergoing assisted reproductive technology between February 2018 and May 2020 at the single fertility center. The assignment to each protocol was based on the optimal treatment for each patient. Patients taking DNG 2 mg continuously were assigned in the DNG group(n = 73). The other patients were allocated in DYG group(n = 77). All viable embryos were cryopreserved for subsequent transfer. The main outcome measures were the mature oocyte and fertilization rates. During this study, no premature LH surge was detected. A smaller number of oocytes were retrieved in the DNG group than in the DYG group (6.18 ± 3.60 vs. 9.85 ± 5.77); however, the rate of mature oocytes was significantly higher in the DNG group than in the DYG group (89.1 % vs. 78.9 %). The fertilization rate was comparable between two groups. Therefore, patients taking DNG for PPOS can continue endometriosis treatment and obtain good-quality embryos during COH. Further prospective randomized-controlled trial should be performed to confirm of this novel strategy of DNG.

New trial of progestin-primed ovarian stimulation using dydrogesterone versus a typical GnRH antagonist regimen in assisted reproductive technology

PURPOSE

To compare the clinical and ongoing pregnancy rates between a protocol using oral dydrogesterone with human menopausal gonadotropin (HMG) for progestin-primed ovarian stimulation (PPOS) and the typical gonadotropin-releasing hormone (GnRH) antagonist regimen in women undergoing controlled ovarian hyperstimulation (COH).

METHODS

This was a prospective, controlled study of 251 women who underwent COH for in vitro fertilization between October 2016 and July 2017. The patients were allocated alternately into two groups: a dydrogesterone protocol (study group) and a GnRH antagonist protocol (control group). In study group, dydrogesterone (20 mg/day) plus HMG (150 or 225 IU) were administered simultaneously beginning on days 2 or 3 of the menstrual cycle. In both groups, all high-quality embryos were cryopreserved for later transfer. The primary outcome was the ongoing pregnancy rate at 12 weeks per frozen-thawed embryo transfer (FET) and the secondary outcome was the clinical pregnancy rate.

RESULTS

None of the patients experienced a premature luteinizing hormone surge. During the follow-up period, 397 FET cycles were completed. The ongoing pregnancy rates at 12 weeks were 40.0% in study group versus 38.1% in control group (absolute difference 1.9%; 95% CI - 6.83 to 17.2%). The clinical pregnancy rate in study group (52.8%) was also not inferior to that in control group (49.5%; absolute difference 3.3%; 95% CI - 4.02 to 20.2%).

CONCLUSIONS

The clinical and ongoing pregnancy rates in study group were comparable to those in control group. Therefore, PPOS with dydrogesterone is a reasonable option to provide COH.

Severe Re-expansion Pulmonary Edema Induced by One-Lung Ventilation

We present 2 cases of severe re-expansion pulmonary edema (RPE) after one-lung ventilation (OLV) for thoracic surgery. A 32-y-old woman with multiple lung metastases developed severe RPE after OLV during lung resection surgery. A 37-y-old man with infective endocarditis also developed severe RPE after OLV for mitral valve plasty with minimally invasive cardiac surgery. In both cases, results of a preoperative pulmonary function test and oxygenation were almost normal, and pleural effusion or pulmonary congestion was not detected in preoperative computed tomography; however, there was a possibility that subclinical lung injury existed before surgery. The levels of interleukin-8 and monocyte chemotactic protein-1, which are thought to play important roles in the development of lung injury, in bronchial secretions were extremely high after the onset of RPE. These results suggest that the pathogenesis of RPE shares, at least in part, a common pathophysiology of acute lung injury.

Adenosine and adenosine uptake inhibitors potentiate the neuromuscular blocking action of rocuronium mediated by adenosine A(1) receptors in isolated rat diaphragms

BACKGROUND

Adenosine, which pre-junctionally modulates neuromuscular transmission, and adenosine uptake inhibitors, which increase extracellular adenosine, have been used clinically. We investigated the effects of adenosine, dipyridamole and midazolam on the neuromuscular blocking action of rocuronium.

METHODS

Isometric twitch tensions of rat nerve-hemidiaphragm preparations elicited by indirect (phrenic nerve) supra-maximal stimulation at 0.1 Hz were evaluated (n=6 in all data).

RESULTS

Pre-treatments with adenosine (0.1 and 1 microM) and CCPA (1 microM, adenosine A(1) receptor agonist), but not that with CGS21680 (0.5 microM, A(2) receptor agonist), shifted the rocuronium concentration-twitch tension curves to the left and decreased the rocuronium concentration for 50% twitch depression (IC(50)) compared with the control (P<0.01). The leftward shift induced by 1 microM adenosine was inhibited by pre-treatments with theophylline (50 microM, non-selective adenosine receptor antagonist) and DPCPX (0.2 microM, A(1) receptor antagonist) but not by that with DPMA (5 microM, A(2) receptor antagonist). Pre-treatments with dipyridamole and midazolam, adenosine uptake inhibitors, shifted the curve to the left and decreased IC(50) at supra-therapeutic concentrations (10 and 2.5 microM, respectively) but not at clinical concentrations (2 and 0.5 microM, respectively), and the leftward shifts were inhibited by pre-treatment with DPCPX (0.2 microM).

CONCLUSION

The results indicate that adenosine potentiates the neuromuscular blocking action of rocuronium mediated by adenosine A(1) receptors and that supra-therapeutic concentrations of dipyridamole and midazolam also potentiate the action of rocuronium by increasing endogenous adenosine concentration.

A woman who required long-term mechanical ventilation to treat limbic encephalitis during pregnancy

We describe our experience with a woman who had severe non-herpetic acute limbic encephalitis at 20 weeks' gestation. Despite receiving mechanical ventilation for about 3 months because of impaired consciousness and frequent convulsions, she had a normal delivery and an uneventful recovery with no sequelae. The patient did not respond to treatment with antiviral agents. Anticonvulsant agents were given while monitoring plasma drug concentrations. Early treatment and the prevention of complications apparently contributed to good outcomes in the mother and child.

5,6-Dichloro-1-methylgramine, a non-toxic antifoulant derived from a marine natural product

The laboratory culture of the barnacle, Balanus amphitrite has made it possible to supply cypris larvae for antifouling assays all year round. The settlement of cyprids obtained from cultured B. amphitrite was indistinguishable from cyprids reared from field-collected barnacles. In laboratory cyprid settlement assays of extracts from marine sessile organisms, antifouling activity was expressed as the 99% inhibitory concentration (IC99), and toxicity as the 30% lethal concentration (LC30). The lipophilic extract of the marine bryozoan, Zoobotryon pellucidum, which showed promising antifouling activity, yielded 2,5,6-tribromo-1-methylgramine (TBG) by bioassay-guided isolation. The inhibitory activity of TBG was 6 times as strong as that of bis-(n-butyltin)oxide (TBTO), while its toxicity to cypris larvae was one-tenth that of TBTO. A structure-activity relationship study with 155 indole derivatives led to the discovery of the non-toxic antifoulant candidates 5,6-dichlorogramine, 5-chloro-2-methylgramine, and 5,6-dichrolo-1-methylgramine (DCMG), the latter being selected as the antifouling paint ingredient for performance evaluation tests (panel tests) following the results of a preliminary safety tests. A silicone-based antifouling paint containing 5-10% of DCMG was prepared and tested in the field; the painted surfaces remained almost barnacle-free for 1.5 years similar to silicone coatings such as Biox. Since the leaching rate of DCMG from the paint surface could be controlled by the addition of an acrylic acid-styrene copolymer (ASP), the life of the antifouling performance is expected to be improved. Thus, an extremely non-toxic silicone-based antifouling paint containing DCMG is under development.

Left ventricular mechanical performance in elderly patients after induction of anaesthesia. A comparison of inhalational induction with sevoflurane and intravenous induction with fentanyl and propofol

We investigated changes in left ventricular mechanical performance in 40 patients aged > 70 years in whom anaesthesia had been induced with sevoflurane or with fentanyl and propofol. The ratio of ventricular contractility to arterial properties, which reflects left ventricular performance, was estimated from the ratio of ventricular end-systolic elastance to effective arterial elastance. This ratio decreased after induction in both groups, the magnitude of the decrease being significantly greater in the fentanyl/propofol group than in the sevoflurane group. Decreases in mean arterial pressure after induction of anaesthesia in the two groups were similar, whereas the magnitude of the decrease in heart rate in the sevoflurane group was greater than that in the fentanyl/propofol group. Sevoflurane may therefore be preferable to fentanyl and propofol for induction of anaesthesia in elderly patients because of its lesser effect on left ventricular performance.

Severe paradoxical intracranial embolism and pulmonary emboli during hip hemiarthroplasty

Both paradoxical intracranial embolism, an intracranial arterial embolism caused by venous embolic material that has passed through a right-to-left shunt, and pulmonary arterial embolism are life-threatening complications of joint arthroplasty. We report a case of severe paradoxical intracranial embolism and pulmonary embolism that occurred during hip hemiarthroplasty.

Lightwand intubation is associated with less hemodynamic changes than fibreoptic intubation in normotensive, but not in hypertensive patients over the age of 60

PURPOSE

To compare the effects of the lightwand and fibreoptic techniques for intubation, neither of which require laryngoscopy, on hemodynamic responses associated with tracheal intubation in normotensive and hypertensive elderly patients.

METHODS

Eighty-eight normotensive and hypertensive patients aged more than 60 yr were randomly allocated to either the lightwand (LN and LH group, n=22 in both) or the fibreoptic group (FN and FH group, n=22 in both). All intubations were performed after induction of anesthesia with fentanyl and propofol and muscle relaxation with vecuronium. Systolic and mean arterial pressures (SAP and MAP) and heart rate (HR) were recorded, and rate-pressure product (RPP) and the change from "before intubation" to "immediately after intubation" of each variable (triangle upMAP triangle up,HR and triangle upRPP) were calculated.

RESULTS

In normotensive patients, significantly smaller triangle upMAP, triangle upHR and triangle upRPP were observed in the LN group than in the FN group (P <0.05). In hypertensive patients, no significant differences between the LH group and the FH group were found in triangle upMAP or triangle upHR, while values of mean RPP in both groups were less than 20,000.

CONCLUSION

We conclude that the lightwand technique significantly attenuates hemodynamic changes following intubation in comparison with fibreoptic intubation in normotensive patients over the age of 60. Hemodynamic changes following intubation using the lightwand technique and the fibreoptic technique in hypertensive elderly patients are similar. However, both techniques are useful for intubation in hypertensive elderly patients in terms of RPP.

Involvement of capsaicin-sensitive fibers in spinal NMDA-induced glutamate release

The activation of spinal NMDA receptors can evoke glutamate release through the production of nitric oxide (NO) within the spinal cord, resulting in pain-relating behavior. In this study, we investigated the involvement of capsaicin-sensitive primary afferents in this phenomenon using in vivo intrathecal microdialysis. Intrathecal NMDA perfusion evoked increases in the concentrations of NO metabolises and glutamate and in pain-related behavior in both neonatal capsaicin and vehicle-treated rats. Although the degrees of increase in NO metabolises in capsaicin- and vehicle-treated rats were not significantly different, capsaicin-treated rats showed significantly smaller increases in glutamate concentration and pain-related behavior than did vehicle-treated rats. Our results showed that glutamate release from capsaicin-sensitive primary afferent terminals is involved in spinal NMDA-induced pain.

Analysis of T cell receptor V(beta) gene expression and clonality in bronchoalveolar fluid lymphocytes from a patient with chronic eosinophilic pneumonitis

Chronic eosinophilic pneumonitis (CEP) is characterized by longstanding respiratory symptoms accompanied by a massive pulmonary eosinophil infiltration. T lymphocytes in bronchoalveolar lavage (BAL) from patients with chronic eosinophilic pneumonitis are considered to recognize unknown antigens. To analyze the pathogenesis of CEP, we examined the T cell receptor (TCR) repertoire and T cell clonotype of BAL lymphocytes and peripheral blood lymphocytes (PBLs) in a 66-year-old woman patient with CEP. The expression of TCR BV gene was analyzed by the family PCR method using specific primers for 20 TCR BV genes and BC gene. The clonotype of BAL and peripheral T cells was examined by the PCR-single-strand conformation polymorphism (SSCP) method. Functional sequences of some T cell clones were also carried out. A TCR repertoire of BAL T cells was heterogeneous as well as PBLs. However, SSCP analysis showed that distinct T cell clonotypes were detected in BAL T cells, TCR BV3, BV4, BV6, BV8, BV9, BV14, and BV18-positive T cell clones especially, expanded clonally in BAL from the patient. Sequencing analysis showed that GVD, LGG, RDXS, and SSG amino acid sequence motif were found in the CDR3 in lung-specific T cells. BAL-specific T cell clones accumulated in the patient with CEP. Thus, we can conclude that BAL T cells are induced by the antigen-driven stimulation and these cells might play a crucial role in the generation of CEP.

Peripheral nitric oxide in carrageenan-induced inflammation

Recent studies have suggested that nitric oxide (NO) peripherally produced by different nitric oxide synthase (NOS) isoforms contributes to edema formation and development of hyperalgesia. The present study was designed to examine the effects of NOS isoforms on NO release in carrageenan-induced inflammation at various time points. A microdialysis probe was implanted subcutaneously into the glabrous skin of hindpaws of Sprague-Dawley rats under pentobarbital anesthesia. After sample collection to obtain the basal level of the total amount of nitrite and nitrate (NO2-/NO3-), modified Ringer solution, a non-selective NOS inhibitor, NG monomethyl-L-arginine acetate (L-NMMA), or an iNOS inhibitor, aminoguanidine hemisulfate (AG) was perfused through the microdialysis probe. 2 mg of carrageenan was injected into the plantar surface of the probe-implanted hindpaw. Carrageenan was also injected in rats that had undergone sciatic nerve sectioning. Carrageenan significantly increased the dialysate concentrations of NO2-/NO3- for more than 8 h. L-NMMA suppressed the carrageenan-induced increase in NO2-/NO3- concentration. Although AG did not suppress the increase in NO2-/NO3- for the first 2 h after carrageenan injection, significant suppression of the increase in NO2-/NO3- was observed from 2.5 h after carrageenan injection. In the rats in which the sciatic nerves had been denervated, the increases in concentrations of NO2-/NO3- were completely suppressed up to 3 h and partially suppressed 4.5-8 h after carrageenan injection. The results of the current study show that carrageenan induces peripheral release of NO, the production of which is mediated by nNOS in the early phase and by both nNOS and iNOS in the late phase of carrageenan-induced inflammation.

[Anesthesia for tricuspid valve replacement after heart transplantation]

A 41 year old male patient had received heart transplantation in U.S. in 1993. When myocardial biopsy was performed in 1998, tendinous cords of the tricuspid valve were injured. Tricuspid regurgitation developed along with right heart insufficiency, and the patient was scheduled for tricuspid replacement. For induction of anesthesia, midazolam and fentanyl were used. After induction, both blood pressure and pulse rate were stable. During extracorporeal circulation, perfusion pressure was controlled at 70-80 mmHg, and the duration of cardio-pulmonary perfusion was about 90 minutes. For withdrawal from extracorporeal circulation, dopamine and dobutamine were used. The course was steady and normal after the withdrawal. In tricuspid valve replacement after heart transplantation, stabilized anesthetic course could be maintained using midazolam and fentanyl.

The effects of peripheral administration of a novel selective antagonist for prostaglandin E receptor subtype EP(1), ONO-8711, in a rat model of postoperative pain

Mechanically evoked pain, also known as incident pain, induced by coughing or deep breathing after surgery leads to potentially devastating consequences. It is generally thought that the prostaglandin receptor- (especially, the receptor for prostaglandin E(2), EP receptor) mediated sensitization of sensory nerve fibers is a key contributor to the generation of hyperalgesia. We examined whether a peripherally administered novel selective EP(1) antagonist, ONO-8711, would be a potential analgesic for incision-induced mechanical hyperalgesia. We used a rat model of postoperative pain introduced by Brennan et al. (1). Withdrawal thresholds to punctate stimulation and response frequencies to nonpunctate mechanical stimulation were determined by using von Frey filaments applied adjacent to the wound and directly to the incision site of the hind paw, respectively. Mechanical hyperalgesia to punctate and nonpunctate stimuli was observed 2 and 24 h after the incision. ONO-8711 (2, 10, or 50 microg) or saline was administered subcutaneously into the hind paw on the ipsilateral side to the incision. ONO-8711 significantly (P < 0.01) increased the withdrawal thresholds to punctate mechanical stimulation and significantly (P < 0.01) decreased the response frequencies to nonpunctate mechanical stimulation in a dose- and time-dependent manner 2 and 24 h after the incision. We conclude that EP(1) receptor-mediated sensitization of sensory nerve fibers may contribute to the generation of mechanical hyperalgesia produced by incisional surgery, and that the EP(1) receptor antagonist ONO-8711 may be an option for treatment of postoperative pain, especially incident pain.

IMPLICATIONS

The peripheral administration of an antagonist for EP(1) receptor that is a subtype of prostaglandin E receptors can inhibit the mechanical hyperalgesia induced by a surgical incision.

The involvement of adenosine neuromodulation in pentobarbital-induced field excitatory postsynaptic potentials depression in rat hippocampal slices

We investigated the contribution of adenosine neuromodulation to mechanisms of pentobarbital-induced depression of excitatory synaptic transmission in vitro. Transverse hippocampal slices were prepared from brains removed from isoflurane-anesthetized male Wistar rats. Field excitatory postsynaptic potentials (fEPSPs), elicited by orthodromic electrical stimulation of Schaffer collateral at 0.05 Hz, were recorded from the CA1 region in oxygenated artificial cerebrospinal fluid. Amplitude of fEPSP was analyzed for assessing drug effects. Pentobarbital (100 microM) transiently depressed fEPSPs (P<0.01); i.e., fEPSP was initially depressed to approximately 60% of control and then recovered to approximately 80% of control. The fEPSP depression was partially suppressed by pretreatment with 50 microM aminophylline, a nonselective adenosine receptor antagonist, and 0.2 microM 3, 7-Dimethyl-1-propagylxanthine, an adenosine A(1) receptor antagonist (P<0.01 each). However, the fEPSP depression was not affected by pretreatment with 10 microM 8-cyclopentyl-1, 3-dipropylxanthine, an A(2) receptor antagonist, or 10 microM bicuculline, a gamma-aminobutyric acid (GABA) A receptor antagonist. The results indicate that adenosine neuromodulation through A(1) receptors and other undefined mechanisms, which are independent from GABAergic mechanisms, are involved in pentobarbital-induced depression of excitatory synaptic transmission.

The effects of midazolam and ketamine on D-tubocurarine-induced twitch depression in septic rat diaphragm

The aim of this study was to elucidate the effects of midazolam and ketamine on neuromuscular blockade induced by non-depolarizing muscle relaxants (NDMRs) under the condition of sepsis induced by panperitonitis. A CLP operation (laparotomy, cecal ligation, and puncture of the cecum; septic group) or sham laparotomy (sham group) was performed on rats under O2-isoflurane anesthesia. At 18 hours after the operation, isometric twitch tensions of rat nerve-hemidiaphragm preparations elicited by indirect or direct stimulation at 0.1 Hz were measured. Midazolam enhanced the dTc (1 microM)-induced twitch depression (p < 0.05) at a high concentration (10 microM) in the septic group but not in the sham group. Ketamine enhanced the dTc (1 microM)-induced twitch depression in the sham group (p < 0.01) but not in the septic group. Midazolam and ketamine had no effect on directly elicited twitch tensions in either group. The results indicate that sepsis facilitates the midazolam-induced enhancement of the neuromuscular blocking effect of dTc but, conversely, inhibits the ketamine-induced enhancement. Sepsis elicits manifold alterations in the influence of intravenous anesthetics and sedatives on NDMR-induced neuromuscular blockade.

Analgesic mechanisms of ketamine in the presence and absence of peripheral inflammation

BACKGROUND

The studies on the mechanisms of ketamine antinociception have led to conflicting results. In this study, the authors investigated the contribution of supraspinal monoaminergic descending inhibitory system to ketamine analgesia for acute nociception and inflammation-induced hyperalgesia.

METHODS

Male Sprague-Dawley rats were used. The paw withdrawal latencies to radiant heat stimuli were measured to assess the thermal nociceptive threshold. The analgesic effects of intrathecal or intraperitoneal ketamine were examined in the rats that received unilateral intraplantar carrageenan and in those that were untreated. In addition, it was examined whether pretreatment with intrathecal yohimbine or methysergide inhibited the analgesic effects of ketamine. Using an intrathecal microdialysis method, noradrenaline and 5-hydroxytryptamine concentrations in lumbar cerebrospinal fluid were measured after intraperitoneal ketamine in both saline- and carrageenan-treated rats.

RESULTS

In the untreated rats, intraperitoneal but not intrathecal ketamine produced antinociceptive effects in a dose-dependent manner. Pretreatment with intrathecal yohimbine or methysergide inhibited these antinociceptive effects. Intraplantar carrageenan significantly reduced paw withdrawal latencies on the injected paw but not on the contralateral paw. Both intraperitoneal and intrathecal ketamine reversed the shortened paw withdrawal latencies on the injected side in a dose-dependent manner without any effects on the contralateral side. Neither yohimbine nor methysergide inhibited these antihyperalgesic effects. In analyses of monoamines, the magnitude of increase in monoamines after intraperitoneal ketamine was significantly smaller in the carrageenan-treated rats than in the saline-treated rats.

CONCLUSION

These results demonstrated that ketamine produced antinociceptive effects through an activation of the monoaminergic descending inhibitory system, whereas, in a unilateral peripheral inflammation-induced hyperalgesic state, the monoaminergic system did not contribute to the antihyperalgesic effects of ketamine. The mechanisms of the antinociceptive and antihyperalgesic properties of ketamine are different.

Activation of peripheral NMDA-nitric oxide cascade in formalin test

BACKGROUND

It has been suggested that peripheral glutamate and nitric oxide (NO) released by tissue-damaging stimuli play an important role in peripheral nociceptive transmission. This study was conducted to determine whether NO was released in the periphery after subcutaneous injection of formalin and whether the peripheral N-methyl-d-aspartate (NMDA)-NO cascade was activated.

METHODS

During pentobarbital anesthesia, a microdialysis probe was implanted subcutaneously into the glabrous skin of both hind paws of Sprague-Dawley rats. After sample collection to obtain the basal level of NO metabolites (total amount of nitrite [NO2-] and nitrate [NO3-] [NO2--NO3-]), 5% formalin was injected into the plantar surface of the right hind paw during perfusion of the dialysis catheters with artificial cerebrospinal fluid (ACSF), the NO synthase inhibitor NG-monomethyl-L-arginine acetate, or the NMDA antagonist D,l-2-amino-5-phosphonovaleric acid through a microdialysis probe. Formalin also was injected in the animals that underwent sciatic nerve sectioning. In another series of experiments, NMDA was perfused through one probe. Samples for measurement of NO2--NO3- were collected and immediately analyzed using high-performance liquid chromatography.

RESULTS

Subcutaneous formalin significantly increased the dialysate concentrations of NO2--NO3- (maximum increase 144 +/- 12% of baseline value 30 min after formalin administration; P < 0.05) on the side ipsilateral to the injection. Both NG-monomethyl-l-arginine acetate and D, l-2-amino-5-phosphonovaleric acid significantly (P < 0.05) suppressed the formalin-induced increases in NO2--NO3- concentration. In the rats with denervation of the sensory nerves, formalin did not change the NO2--NO3- concentration. In addition, NMDA perfusion significantly (P < 0.05) increased the concentrations of NO2--NO3-.

CONCLUSION

The results of the current study show that subcutaneous formalin injection induces peripheral release of NO, the production of which is mediated by activation of NMDA receptors in the peripheral nervous system.

Analgesic effect of intrathecal desipramine on carrageenan-induced thermal hyperalgesia in the rat

We examined if intrathecal desipramine, a selective norepinephrine reuptake inhibitor, would modulate peripheral inflammation-induced hyperalgesia. Rats were chronically implanted with a lumbar intrathecal catheter and paw withdrawal latency (PWL) to noxious heat stimuli was assessed. Unilateral hindpaw inflammation was induced by intraplantar carrageenan injection. Carrageenan injection significantly (P < 0.05) reduced PWL of the injected paw (from mean 11.4 (SEM 0.6) s to 3.5 (0.2) s, 3 h after carrageenan), but not of the contralateral side (from 11.6 (0.2) s to 11.2 (0.5) s). Intrathecal desipramine 10, 30, 60 and 100 micrograms, which did not produce analgesic effects in untreated rats, dose-dependently reversed the shortened PWL on the ipsilateral side (3.3 (0.2), 5.3 (0.4), 6.2 (0.3) and 9.6 (0.2) s, respectively) without affecting the contralateral side. Pretreatment with intrathecal yohimbine 10 micrograms did not antagonize the anti-hyperalgesic effects of desipramine (from 9.6 (0.2) to 9.8 (0.3) s). Our results suggest that the mechanism underlying the analgesic effect of desipramine on inflammation-induced hyperalgesia is unlikely to be inhibition of norepinephrine reuptake within the spinal cord.

Prevention by methylprednisolone of increased circulating tumor necrosis factor-alpha levels and lung injury associated with systemic inflammatory response syndrome due to intraperitoneal hyperthermia

We previously demonstrated that intraperitoneal hyperthermic perfusion (IPHP), which is performed clinically as a treatment for patients with advanced gastrointestinal cancer, can lead to increased serum tumor necrosis factor-alpha (TNF-alpha), systemic inflammatory response syndrome (SIRS), and acute lung injury. Glucocorticoids inhibit the production and actions of TNF-alpha. We investigated whether pretreatment with methylprednisolone (MPS) may modulate serum TNF-alpha and lung injury in patients subjected to IPHP. Serum TNF-alpha was not detected in the patients pretreated with MPS, whereas serum TNF-alpha increased in the control patients (45.7 +/- 8.3 pg/mL, mean +/- SEM) after IPHP. Postoperative lung injury scores were significantly lower in patients pretreated with MPS than in the control patients (P < 0.001).

IMPLICATIONS

Pretreatment with methylprednisolone attenuates the increase in circulating tumor necrosis factor-alpha and prevents lung injury in this systemic inflammatory syndrome due to intraperitoneal hyperthermic perfusion.

Formalin-induced nociception activates a monoaminergic descending inhibitory system

Neural plasticity of afferent pain pathways that is induced by prolonged or repeated noxious stimuli may contribute to activate intrinsic inhibitory mechanisms in CNS. In order to clarify the role of the monoaminergic descending inhibitory system in acute nociception and inflammatory pain, we examined if this inhibitory system would modulate the tonic response to formalin-induced nociception. Yohimbine, alpha2 adrenergic antagonist, or methysergide, serotonin antagonist was administered intrathecally before or after subcutaneous 2% formalin injection into the plantar of the hind paw in rats. In another series of the experiment, the tissue of the spinal dorsal half of the untreated rats and post-formalin-treated rats were sampled and analyses of monoamine levels were carried out by HPLC. The subcutaneous formalin evoked biphasic flinching behavior of the injected paw. Intrathecal pretreatment with yohimbine and methysergide produced a significantly greater increase in the number of flinches than in the control in phase 1, intermediate period and phase 2. Posttreatment with yohimbine and methysergide showed a significantly greater increase in the number of flinches in phase 2. Furthermore, formalin injection induced significant increases in noradrenaline, MHPG, serotonin (5-hydroxytryptamine; 5-HT) and 5-HIAA concentrations in both the ipsi- and contralateral dorsal halves. These results suggest that the pain state produced by formalin-induced chemical and/or inflammatory nociception is under the modulation of the monoaminergic (noradrenergic and serotonergic) descending inhibitory system.

[Pathologic reconsideration on allergic bronchopulmonary aspergillosis and mycosis]

We examined lung specimens that fulfilled the pathological criteria of Bosken and were obtained from 5, patients with allergic bronchopulmonary aspergillosis/mycosis (ABPA/M). A finding common to all 5 was the presence of hard mucous plugs containing numerous eosinophils and fungal hyphae in the bronchi, showing central bronchiectasis. Bronchocentric granulmatosis with tissue eosinophilia (4 cases), xanthogranulomatous lesions (3 cases), eosinohilic pneumonia (2 cases) and organizing pneumonia (3 cases) were recognized only in bronchi distal to the mucous plugs (BMP). Almost normal lung parenchyma could be seen in some areas distal to the BMP. We found clusters of degenerated eosinophils (CDE) showing a "fir-tree like structure" and fungal hyphae in both the mucous plugs and the peripheral lesions. Most CDEs were free in the exudate and were not engulfed by macrophages. The presence of fungi in the mucous plugs may have caused marked inflammation in the wall around the BMP, which may have made the walls fragile and caused central bronchiectasis. The fungi in the mucous plugs may have caused the peripheral lesions via aerogenous dissemination. For this reason, we conclude that ABPA/M is an infectious disease, and that the primary lesion in ABPA/M is the formation of mucous plugs. Therefore, the presence of mucous plugs containing fungi and many eosinophils is diagnostic of ABPA/M.

Formalin-induced release of excitatory amino acids in the skin of the rat hindpaw

Application of glutamate to skin evokes pain-related behaviors [S.M. Carlton, G.L. Hargett, R.E. Coggeshall, Localization and activation of glutamate receptors in unmyelinated axons of rat glabrous skin, Neurosci. Lett., 197 (1995) 25-28; D.L. Jackson, C.B. Graff, J.D. Richardson, K.M. Hargreaves, Glutamate participates in the peripheral modulation of thermal hyperalgesia in rats, Eur. J. Pharmacol., 284 (1995) 321-325.] and peripherally-administered glutamate antagonists can prevent the nociception produced by inflammation [E.M. Davidson, R.E. Coggeshall, S.M. Carlton, Peripheral NMDA and non-NMDA glutamate receptors contribute to nociceptive behaviors in the rat formalin test, NeuroReport, 8 (1997) 941-946; Jackson et al., 1995.] In this study, the concentrations of glutamate and aspartate in the plantar of the rat hindpaws were measured before and after the subcutaneous administration of formalin. Increases in glutamate and aspartate concentrations were observed on the ipsilateral side, but not on the contralateral side, to the injection. This shows that nociception and inflammation caused by formalin injection induces the release of peripheral glutamate and aspartate, which would contribute to nociception and inflammatory pain.

Premedication with oral dextromethorphan reduces postoperative pain after tonsillectomy

The aim of the present study was to examine whether premedication with dextromethorphan, a clinically available N-methyl-D-aspartic acid (NMDA) receptor antagonist, could reduce postoperative pain after tonsillectomy. Thirty-six patients scheduled for elective bilateral tonsillectomy were investigated in a double-blinded, randomized study. The patients were randomly assigned to one of three groups: control, dextromethorphan 30 mg (Dex 30), and dextromethorphan 45 mg (Dex 45) groups. In the control group, premedication was with oral placebo and intramuscular (i.m.) midazolam and atropine. In the Dex 30 and Dex 45 groups, patients were premedicated with i.m. midazolam and atropine and oral dextromethorphan 30 mg and 45 mg, respectively. Pain was evaluated repeatedly throughout 7 postoperative days, at rest and on swallowing, using a self-rating visual analog scale (VAS). The total doses of analgesics administered postoperatively were also recorded. The Dex 45 group showed significantly lower VAS scores than the control group both at rest and on swallowing throughout the 7 days. The total doses of postoperative analgesics in the Dex 45 group were significantly less than those in the control group. The Dex 30 group showed significantly lower VAS scores than the control group at rest, but not on swallowing. These results indicate that premedication with Dex 45 reduces postoperative pain after tonsillectomy, not only at rest but on swallowing.

IMPLICATIONS

Recently, it has been suggested that central sensitization caused by the activation of N-methyl-D-aspartic acid receptors may contribute to the postoperative pain. We found that premedication with 45 mg of dextromethorphan, a clinically available N-methyl-D-aspartic acid receptor antagonist, reduced postoperative pain after tonsillectomy.

Antinociceptive interaction of intrathecal alpha2-adrenergic agonists, tizanidine and clonidine, with lidocaine in rats

BACKGROUND

The intrathecal alpha2-adrenergic agonist, clonidine, has been shown to have considerable antinociceptive effect, although clonidine causes hypotension and bradycardia. The combination of intrathecal clonidine and local anesthetics enhances analgesic effects, whereas the combination may cause marked hypotension and motor blockade, which may limit the clinical application of the combination. Tizanidine, another alpha2-adrenergic agonist, has also provided antinociception without producing pronounced hemodynamic changes. This study was designed to evaluate the antinociceptive and hemodynamic interactions of tizanidine and clonidine with lidocaine.

METHODS

Male Sprague Dawley rats were chronically implanted with lumbar intrathecal catheters. The tail-flick test was used to assess the thermal nociceptive threshold. The ability of intrathecal tizanidine, clonidine, lidocaine, or the combinations of alpha2-adrenergic agonist and lidocaine to alter the tail-flick latency was examined. To characterize the antinociceptive interaction, the isobolographic analysis was applied. Additionally, the motor function, blood pressure and heart rate after intrathecal administration of drugs and combinations were also monitored.

RESULTS

Intrathecal tizanidine, clonidine, or the combinations increased the tail-flick latency in dose- and time-dependent fashion without affecting motor function. The order potencies (dose producing a 50% of peak effect, in microg) of tizanidine and clonidine were 1.8 and 0.75, respectively. With isobolographic analysis, tizanidine with lidocaine and clonidine with lidocaine showed significantly synergistic antinociceptive interaction. Potency ratio analysis and fractional analysis also confirmed the synergistic interaction. At the doses in the combinations showing comparable antinociception, tizanidine with lidocaine, unlike clonidine with lidocaine, did not affect motor function or blood pressure.

CONCLUSION

The authors' results show that intrathecal tizanidine and clonidine synergistically interact with lidocaine so that the degree of antinociception to somatic noxious stimuli are enhanced. The antinociceptive synergistic interaction between tizanidine and lidocaine may be useful in clinical practice without affecting blood pressure, heart rate, or motor function.

Plasma somatostatin correlates with blunted thyrotropin secretion after stimulation by thyrotropin-releasing hormone in critical illness

To clarify whether plasma somatostatin affects thyrotropin secretion in critical illness, plasma somatostatin and thyrotropin responses to thyrotropin-releasing hormone were studied in forty-three critically ill patients. High somatostatin levels were associated with blunted thyrotropin secretion in critically ill patients. There was an inverse correlation between plasma somatostatin levels and the maximum increment of thyrotropin after stimulation by thyrotropin-releasing hormone. Decreased somatostatin and increased thyrotropin secretion before discharge from the intensive care unit were demonstrated in survivors. On the other hand, non-survivors maintained high somatostatin levels and had blunted thyrotropin secretion during their intensive care admission. These results suggest that high plasma somatostatin levels may play a role in the blunted thyrotropin secretion observed in critical illness.

[Importance of instructing anesthesiologists in handwashing against bacterial contamination]

The importance of handwashing in preventing the spread of nosocomial infection has been stressed. Using a modified glove juice method, we have already shown the efficacy of washing of anesthesiologists' hands with alcohol based antiseptic solutions against bacterial contamination. The efficacy of handwashing, however, varied because many anesthesiologists washed only the palm and the back. In the present study, we instructed them to wash their hands using rubbing method, from finger tip to the wrist until drying the solutions completely. We compared the efficacy of handwashing, by decrease of bacteria counts after general anesthesia, between the instructed method and the customary way which was done ordinarily in the ward. The instructed method was more effective on the decrease of bacteria counts than the customary way. In the instructed method, the efficacy of handwashing was not different between the antiseptic solutions. In conclusion, doctors not only should practice handwashing with the antiseptic solutions after each contact with the patient, but also wash their hands from the finger tip to the wrist until they become completely dry.

Effects of thoracic epidural anesthesia on changes in ischemic myocardial metabolism induced by intracoronary injection of endothelin in dogs

OBJECTIVE

Thoracic epidural anesthesia (TEA) has been reported to alleviate ischemic damage to the myocardium. Endothelin, an endothelium-derived peptide and a potent coronary vasoconstrictor, may contribute to poor cardiac perfusion and ischemia. The objective was to examine regional myocardial metabolism during ischemia caused by intracoronary injection of endothelin with and without TEA.

DESIGN

The three experimental groups and three treatments were randomized.

SETTING

All studies were conducted in a university research laboratory.

PARTICIPANTS

Thirty anesthetized dogs comprised the study groups.

INTERVENTIONS

Study animals were divided into three groups of 10 animals each identified as normal saline (NS); TEA; and TEA + blood pressure controlled (TEA + BPC). The NS group had 0.5 mL/kg of normal saline injected into the T4-5 epidural space. The TEA group had 0.5 mL/kg of saline containing 1% lidocaine injected into the T4-5 space. The TEA + BPC group had blood pressure and heart rate maintained at pre-epidural injection values by partially occluding the descending aorta and by atrial pacing. Endothelin (15 pmol/kg) was bolus injected into the left anterior descending (LAD) artery of each heart. Systolic and diastolic blood pressure, heart rate, and LAD coronary blood flow (CBF) were monitored. Three minutes after injection of endothelin, myocardial tissue was sampled from the distribution of the LAD artery and from the control, left circumflex (LCx) artery. ATP, ADP, AMP, lactate, and pyruvate were measured by enzymatic methods.

MEASUREMENTS AND MAIN RESULTS

It was found that in each group endothelin consistently decreased LAD CBF, but the decrease was less in the TEA + BPC group. In the tissue distribution of the LAD, the levels of ATP and energy charge potential were lower, and the level of lactate was higher in the NS group than in the TEA or the TEA + BPC groups (p < 0.01).

CONCLUSIONS

These results confirm that (1) endothelin injected into the LAD artery decreases CBF and causes selective myocardial ischemia in a fashion similar to intravascular stenosis of the LAD rather than to mechanical occlusion and (2) TEA, with or without pressure support, lessens the degree of regional ischemia induced by injection of endothelin in the LAD.

[Potentiation of procaine-induced local sensory block by verapamil in rats]

We have studied the effects of calcium-channel blocker, verapamil, on procaine-induced local sensory block. Standardized tail-flick (TF) test was used to investigate the duration and intensity of procaine-induced local conduction block in rats. After obtaining baseline TF latencies (mean; 3.3 sec), two 100 microliters of 0.4% procaine alone, a combination of 0.4% procaine and verapamil (100 micrograms, or 200 micrograms), or a large dose of verapamil (200 micrograms) were injected to the opposite sites of the tail base and TF test was performed every five minutes for 45 minutes. A large dose of verapamil showed no prolongation of TF latencies. The administration of 0.4% procaine alone produced a significant increase of TF latencies and the peak effect of % MPE (percent maximum possible effect) was demonstrated at 4 minutes after the drug injection (mean % MPE; 37.0%). Coadministration of 0.4% procaine and two doses of verapamil produced significant increases of % MPE in a dose-dependent fashion. It was concluded that sensory block by procaine of the peripheral nerves is potentiated by coadministration of calcium-channel blocker, verapamil.

Potentiation of local lignocaine-induced sensory block by calcium channel blockers in rats

We have studied the effects of three different types of calcium channel blockers (verapamil, diltiazem, and nicardipine) on local lignocaine sensory block. The standardized tail flick test was used to measure the duration and degree of lignocaine-induced conduction block in rats. After obtaining baseline tail flick latencies (mean 3.2 s), two 100-microliter doses of 0.3% lignocaine alone, a combination of verapamil 25, 100 or 200 micrograms, diltiazem 25, 100 or 200 micrograms, or nicardipine 0.5, 1.0 or 2.0 micrograms, and a large dose of calcium channel blockers (verapamil 200 micrograms, diltiazem 200 micrograms or nicardipine 2.0 micrograms) were injected on opposite sites of the tail base and the tail flick test was performed every 5 min for 45 min. A large dose of the calcium channel blockers showed no prolongation of tail flick latencies. Administration of 0.3% lignocaine alone produced a significant increase in tail flick thresholds and the peak effect of the percentage maximum possible effect (% MPE) was demonstrated at 5 min after drug injection (mean % MPE 28.8%; P < 0.01 vs baseline). Co-administration of 0.3% lignocaine and three doses of verapamil produced significant increases in area under the curve (AUC) in a dose-dependent fashion. Mean AUC values for 0.3% lignocaine alone and a combination of verapamil 25, 100 or 200 micrograms were 217.5, 502.5, 529.1 and 1600.3, respectively. Almost similar patterns of augmentation in AUC values were demonstrated after addition of different doses of diltiazem or nicardipine to 0.3% lignocaine. We conclude that the use of mixtures of local anaesthetic and calcium channel blocker potentiated lignocaine sensory block at the level of the peripheral nerves.

[Plasma concentration of lidocaine in patients undergoing hepatectomy with continuous epidural anesthesia--influence of extent of hepatectomy and prostaglandin E1 infusion]

We investigated changes in plasma concentration of lidocaine during continuous epidural anesthesia in 21 patients undergoing hepatectomy. According to the extent of hepatectomy, patients were assigned into one of the three groups: partial resection group, lobectomy group, and extended lobectomy group. Lidocaine 2.0 mg.kg-1 with 1: 200,000 epinephrine was epidurally administered in a bolus followed by continuous infusion of lidocaine at the rate of 1.5mg.kg-1.h-1. Plasma lidocaine concentration in the extended lobectomy group showed a significantly higher value than those of other two groups (P < 0.05). Plasma lidocaine was detected in the extended lobectomy group at 12 hs after the surgery, but not in the other two groups. Furthermore we investigated the effects of prostaglandin E1 infusion in 7 patients undergoing extended lobectomy. Plasma lidocaine concentration was not increased in this group. In conclusion, we recommend caution regarding the dose of lidocaine administered for epidural anesthesia during hepatectomy; PGE1 infusion appears to be safe in patients undergoing extended hepatectomy.

Antigenicity of cell wall mannans of Candida albicans NIH B-792 (serotype B) strain cells cultured at high temperature in yeast extract-containing sabouraud liquid medium

Cultivation of Candida albicans NIH B-792 (serotype B) at high temperature (37 degrees C) for 48 h in yeast extract-containing Sabouraud liquid medium (YSLM) provided the following findings in comparison with the findings obtained after incubation at 27 degrees C. Growth of the blastoconidia of this strain was decreased, with a dry weight of 9%, and the cells were deficient in cytokinesis. The cells did not undergo agglutination with serum factor 5 from a commercially available serum factor kit (Candida Check). Mannan (B-37-M) obtained from the cells cultured at 37 degrees C had partially lost its reactivity against serum factor 4 and lost most of its reactivity against serum factor 5 in an enzyme-linked immunosorbent assay (ELISA) in contrast to that (B-27-M) at 27 degrees C. Both cells and mannan prepared by cultivation first at 37 degrees C and then at 27 degrees C entirely recovered their reactivities with serum factors 4 and 5. 1H-nuclear magnetic resonance analysis also revealed that B-37-M had lost a beta-1,2-linked mannopyranose unit and retained a phosphate group. Similar changes were observed in the three other serotype B strains used in the study. The beta-1,2-linked mannooligosaccharides longer than mannotetraose were not included among the products released from B-37-M by mild acid treatment. The results of the inhibition ELISA with a series of beta-1,2-linked mannooligosaccharides from biose to octaose (M2 to M8, respectively) showed that the reactivity against serum factor 4 was inhibited most strongly by the oligosaccharides M4 to M8 and that the reactivity against serum factor 5 was inhibited completely by relatively longer oligosaccharides, M5 to M8, indicating their participation as the antigenic factor 5 epitopes.

Spinal antinociceptive action of an N-Type voltage-dependent calcium channel blocker and the synergistic interaction with morphine

BACKGROUND

Four different voltage-dependent calcium channels (L-, N-, T-, and P-types) are distinguished in the central nervous system. Both L- and N-type calcium channels have been implicated in the release of neurotransmitters from sensory neurons in the spinal cord. It has been demonstrated that intrathecal L-type calcium channel blockers, which alone do not exhibit any antinociceptive effects, potentiate the antinociceptive effect of intrathecal morphine. The current study was designed to investigate the antinociceptive effects of the intrathecally administered N-type calcium channel blocker, omega-conotoxin GVIA (omega-CgTx). The interaction between morphine and omega-CgTx at the level of the spinal cord also was examined.

METHODS

In male Sprague-Dawley rats, lumbar intrathecal catheters were chronically implanted. Tail flick and mechanical paw pressure tests were used to assess thermal and mechanical nociceptive thresholds, respectively. Morphine, omega-CgTx, or a combination of morphine and omega-CgTx was administered intrathecally, and the nociceptive thresholds were determined. Isobolographic analyses were used to define the nature of the functional interactions between morphine and omega-CgTx.

RESULTS

Intrathecal omega-CgTx produced antinociception in a dose- and time-dependent manner. Isobolographic analyses revealed that intrathecal omega-CgTx and morphine interacted synergistically in both nociceptive tests.

CONCLUSIONS

This study indicates the importance of the N-type calcium channel in the spinal cord on nociception and suggests the functional interaction between the N-type calcium channel blocker and opioid at the level of the spinal cord.

[Management of severe pain after extended maxillectomy in a patient with carcinoma of the maxillary sinus]

We treated a 65 year-old man with severe facial pain after extended maxillectomy due to carcinoma of maxillar sinus. He had been suffering from pain at rest, on mastication, or at treatment of surgical wound. Various kinds of analgesics had been tried, but his pain did not disappear. At 17 weeks after the operation, he came to our pain clinic. Because his pain was thought to be due to reflex sympathetic dystrophy (RSD), stellate ganglion blocks (SGB) were performed. After 5 administrations of SGB, pain was reduced markedly but the pain at treatment of wound persisted. We thought that persistent pain would need trigeminal nerve block. Then Gasserian ganglion block was performed directly through an open wound after the operation. After the Gasserian ganglion block, the pain was diminished remarkably. He could tolerate procedures for facial prosthesis. Pain control after the operation in this patient was very efficient to improve his quality of life. Serum concentrations of catecholamines, serotonin and substance P were measured. The levels of norepinephrine and serotonin are related to the mechanism of pain as seen in this patient.

[Effect of preoperative treatment with recombinant human erythropoietin in patients undergoing hemodilutional autologous transfusion]

This study evaluated whether a combination of recombinant human erythropoietin (rHuEPO) and hemodilutional autologous transfusion could reduce homologous blood transfusion in 37 patients who underwent elective urological surgery. A single dose of 6000 IU rHuEPO was administered 2 weeks before operation to patients whose preoperative hemoglobin was less than 12.0 g.dl-1 (8.5-12.0 g.dl-1) (EPO group, n = 15) and compared these with control subjects whose preoperative hemoglobin was more than 12.0 g.dl-1 (non-EPO group, n = 22). Both hemoglobin and hematocrit levels after administration of rHuEPO in the EPO group increased significantly to the same levels as in those in the non-EPO group and remained at these levels. The mean volume of donated autologous blood was 980 g in the EPO group and 110 g in the non-EPO group. The mean surgical blood loss was 1330 g in the EPO group and 1120 g in the non-EPO group. No homologous blood transfusion was required in 80 percent of the cases in both groups: however, homologous transfusions were added to 3 cases in the EPO group and 4 cases in the non-EPO group whose surgical blood loss was over 2500 g. We conclude that the combination of preoperative rHuEPO treatment and hemodilutional autologous transfusion can reduce homologous transfusion during surgery in anemic patients.

[A case of spasticity following spinal cord injury improved by epidural spinal cord stimulation]

Epidural spinal cord stimulation was performed in a patient complaining of spasticity with intractable pain after operation of metastatic spinal tumor. The end of the electrode was positioned along a line extending down the 11th vertebral body. Following confirmation of satisfactory effects during 10 days of trial stimulation, the electrode was permanently implanted. Excellent pain relief (80%) and significant relaxation of spasticity resulted in a medication free period with improved daily activities. Although the treatment of this case resulted in clinical success, the problem concerning the payment of the transmitter remained. We hope that the health insurance system will extend its indications to cover medical fees for the transmitter.

Blood coagulation and fibrinolytic activity during femoral neck prosthetic replacement using bone cement

To assess the blood coagulative and fibrinolytic responses during cemented femoral neck replacement, we measured these parameters in 9 patients, including anti-thrombin III (AT-III), prothrombin time (PT) and activated partial thromboplastin time (APTT) before surgery, just before packing bone cement and after the insertion of the prosthesis. We also measured thrombin-anti-thrombin III complex (TAT), plasmin-alpha 2-plasmin inhibitor complex (PIC), and D-dimer. A significant increase in APTT, and decrease in AT-III and PT were observed before the insertion of bone cement and prosthesis. The value of TAT and D-dimer increased significantly after the insertion of the prosthesis, but there were no significant changes in PIC. The data suggest that blood coagulation is activated after the insertion of bone cement and prosthesis into the femoral shaft, and in addition, the fibrinolysis is also accelerated secondary to the activation of the coagulation. Further investigations are needed to establish whether the activation of the coagulation induced by the cemented replacement exerts a great influence on the appearance of pulmonary thrombosis or circulatory depression.

Acute pulmonary edema associated with transfusion of packed red blood cells

We experienced a patient who suffered noncardiogenic acute pulmonary edema after transfusion of packed red blood cells which contained antigranulocyte antibodies. The data suggested that complement activation and the release of polymorphonuclear protease were involved in the pathogenesis of the complication in the present patient. Furthermore, blood coagulative system was also activated after the transfusion. The underlying mechanisms of the complication are discussed.