[Safety of continuous epidural anesthesia during heart surgery--change of coagulation-fibrinolysis under heparinization]

To confirm the safety of continuous epidural anesthesia during extracorporeal circulation under heparinization, we investigated epidural hematoma formation following the cardiopulmonary bypass in both humans and dogs. In fifteen dogs, divided into three groups, heparin was administered at the dose of 300, 600, or 900 U.kg-1, respectively. In fourteen patients, a dose of 300 U.kg-1 haparin was administered for cardiopulmonary bypass. Although blood coagulation-fibrinolysis dropped into abnormal ranges following heparinization, no epidural hematoma was observed in dog and no patient revealed spinal complication associated with epidural hematoma. These data indicate that continuous epidural anesthesia would be a safe tool for intraoperative anesthesia even during extracorporeal circulation under heparinization.

[Hereditary hemoglobin H disease in Japanese siblings diagnosed by human parvovirus B19 infection]

Hereditary hemoglobin H (HbH) disease was diagnosed in 2 Japanese sisters who presented with aplastic crisis following acute human parvovirus B19 (HPV B19) infection. The proband, an 8-year-old girl, developed persistent fever and pallor, and samples of her peripheral blood showed hypochromic microcytic anemia. Other laboratory data were consistent with hemolytic anemia. Fever and signs of hypochromic microcytic anemia also developed in her sister 9 days later. Cation exchange HPLC analysis of their hemoglobin revealed abnormal hemoglobin migrating faster than HbF, a finding consistent with HbH. Although they presented neither arthralgia nor skin rash, we concluded that their aplastic crisis was induced by HPV B19, because HPV B19 DNA was detected in samples of their peripheral blood by PCR analysis, and HPV B19 IgM and IgG antibody titers were elevated. A genetic analysis of the alpha-globin gene in both sisters and their parents disclosed that the father was heterozygous for alpha-Thal-2, the mother, heterozygous for alpha-Thal-1, and the proband and her sister, double heterozygous for alpha-Thal-1 and alpha-Thal-2. alpha-Thal-2 is a 3.7 kb-deletion allele.

[Antinociceptive effects of intrathecally administered GABA agonists at the spinal cord level]

The present study was designed to investigate antinociceptive effect of GABA agonists regarding visceral as well as somatic noxious stimuli. Following the approval by the institutional animal care committee, an intrathecal catheter was implanted in the subarachnoid space at the L 4/5 level in male Sprague-Dawley rats. The tail flick (TF) test and the colorectal distension test (CD) were used to measure responses to somatic and visceral stimuli, respectively. Threshold in TF test and CD test were measured at 5, 10, 15, 20, 30, 60, 90, 120 and 180 min after the intrathecal injection of 0.1, 1, 5, 20 micrograms of muscimol, 0.01, 0.1, 0.3, 1 microgram of baclofen or normal saline. Percent of maximum possible effect (%MPE) and %area under the curve (%AUC) were calculated by transforming response threshold in TF and CD tests. Repeated measure ANOVA followed by Fisher's PLSD test were used for statistical analysis. Muscimol 0.1 microgram increased mean %MPE in TF test at 10 min to 15% but not in CD test. Muscimol 1, 5 and 20 micrograms significantly increased %MPE at 5 min in TF and CD tests. Muscimol 20 micrograms produced 100%MPE for 180 min after drug injection. Baclofen 0.1, 0.3 and 1 microgram significantly increased %MPE at 5 min in TF and CD test. Antinociceptive effect in TF test seems to be greater than that in CD test. Muscimol caused motor disturbance but baclofen did not. It is concluded that intrathecally administered muscimol and baclofen produced somatic and visceral antinociception in a dose dependent fashion.

Effects of nitroglycerin on fractal features of short-term heart rate and blood pressure variability

PURPOSE

We investigated the effect of nitroglycerin(NTG) on fractal features of short-term heart rate variability (HRV) and blood pressure variability (BPV) using coarse-graining spectral analysis (CGSA).

METHOD

Nine healthy young volunteers participated in this study. Five-minute recordings of electrocardiogram and blood pressure estimated by photoplethysmograph were made during stepwise NTG infusions of 0.2, 0.4, 0.8, and 1.6 microg.kg(-1).min(-1) under rate-controlled breathing at 0.25 Hz. CGSA broke down the total power of the time series into harmonic (low- and high-frequency) and nonharmonic (beta of 1/f(beta) and %fractal) components.

RESULTS

A statistically significant difference from the control period was observed during the maximum dose of NTG infusion, with decrease in mean blood pressure, shortening of mean R-R interval, and increase in plasma norepinephrine and epinephrine. The beta in HRV increased significantly (0.89 +/- 0.06 vs. 1.27 +/- 0.13, P < 0.05). However, %fractal was not affected (47.9 +/- 6.7 vs. 50.1 +/- 4.0). Indicators of parasympathetic and sympathetic nervous system activity showed reduced and increased values, respectively. No change in BPV was observed for any measurement.

CONCLUSION

The data suggest that NTG significantly affected fractal features, as well as harmonic components, of short-term HRV. NTG had no effect on BPV, suggesting a different mechanism for genesis of 1/f(beta) fluctuation in BPV and HRV.

Activation and regulation of the IkappaB kinase in human B cells by CD40 signaling

This study demonstrates that the engagement of CD40 results in the activation of the recently described IkappaB kinase (IKK) in a human B cell line. The kinase appears to reside within the cell in a cytosolic signalsome complex consisting of IKK, IkappaB, and an MKP-1-like molecule. While the binding of CD154 to CD40 induces the assembly of a CD40-TRAF receptor complex, IKK is not recruited to this complex. Nonetheless, a functional link between TRAF2 and IKK activity in B cells is demonstrated by the fact that overexpression of TRAF2 constitutively induces IKK activity, NF-kappaB luciferase and Fas expression. Synergy in the activation of IKK and NF-kappaB-dependent gene expression was observed by the simultaneous engagement of the B cell receptor and CD40, establishing an early means for cross-talk between these two B cell activation pathways. This study discusses the sequential biochemical events that transpire upon CD40 engagement by its ligand in human B cells.

Effective control of Epstein-Barr virus-related hemophagocytic lymphohistiocytosis with immunochemotherapy. Histiocyte Society

The familial form of hemophagocytic lymphohistiocytosis (HLH) is a lethal disorder. Although the prognosis for Epstein-Barr virus-associated HLH (EBV-HLH) remains uncertain, numerous reports indicate that it can also be fatal in a substantial proportion of cases. We therefore assessed the potential of immunochemotherapy with a core combination of steroids and etoposide to control EBV-HLH in 17 infants and children who met stringent diagnostic criteria for this reactive disorder of the mononuclear phagocyte system. Treatment of life-threatening emergencies was left to the discretion of participating investigators and typically included either intravenous Ig or cyclosporin A (CSA). Five patients (29%) entered complete remission during the induction phase (1 to 2 months), whereas 10 others (57%) required additional treatment to achieve this status. In 2 cases, immunochemotherapy was ineffective, prompting allogeneic bone marrow transplantation. Severe but reversible myelosuppression was a common finding; adverse late sequelae were limited to epileptic activity in one child and chronic EBV infection in 2 others. Fourteen of the 17 patients treated with immunochemotherapy have maintained their complete responses for 4+ to 39+ months (median, 15+ months), suggesting a low probability of disease recurrence. These results provide a new perspective on EBV-HLH, showing effective control (and perhaps cure) of the majority of EBV-HLH cases without bone marrow transplantation, using steroids and etoposide, with or without immunomodulatory agents.

Allogeneic hematopoietic stem cell transplantation for patients with hemophagocytic syndrome (HPS) in Japan

Seventeen cases (age at onset, 1 month to 18 years; M/F, 9/8) of hemophagocytic syndrome which received allogeneic hematopoietic stem cell transplantation (SCT) in Japan during the period 1988-1998 are reported. The patients consisted of six familial inheritance-proven erythrophagocytic lymphohistiocytosis (FEL), five familial inheritance-unknown and infective agents-unknown HLH (of which two were highly likely to have been FEL with characteristic CNS signs), and six aggressive Epstein-Barr virus (EBV)-related HLH (of which two were natural killer cell-type large granular leukemia/lymphoma-associated hemophagocytic syndrome, EBV-NK-LGLL-HPS). All cases were treated intensively with immuno-chemotherapy, or with chemotherapy before SCT. As sources of SCT, 12 cases received bone marrow cells (sibling six, father one, URD five), two cord blood, two purified CD34-positive cells, and one PBSC. SCTs were successful in all 17 cases, apart from one receiving CD34-positive SCT. Following SCT, four patients relapsed and five died with a median follow-up of 23 months. Among the relapsed cases, the two EBV-NK-LGLL-HPS previously published as successfully transplanted were included. Among the fatal cases, three patients died from relapsed active disease and the remaining two from fatal post-SCT EBV-positive T cell lymphoma and extensive chronic GVHD, respectively. As of the end of September 1998, 10 patients are alive without disease for 3.5 months to 147 months, while two post-SCT patients are still having therapy for residual/recurrent disease. The Kaplan-Meier analysis showed a 2-year event-free survival after SCT as 54.0+/-13.0%.

Concentration of lidocaine affects intensity of sensory block during lumbar epidural anesthesia

We investigated the effects of a twofold difference in concentration and volume of lidocaine on lumbar epidural block using a cutaneous current perception threshold (CPT) quantitative sensory testing device. Twenty ASA I patients scheduled for elective gynecological surgery were randomly divided into two equal groups to receive either 20 mL of 1% lidocaine or 10 mL of 2% lidocaine through an epidural catheter inserted at the L1-2 interspace. CPTs at 2000-, 250-, and 5-Hz stimulation and sensation to light touch, temperature, and pinprick at ipsilateral dermatomes V, T9, and L2 were measured before and every 5 min until 60 min after the epidural lidocaine. Epidural anesthesia with both solutions produced a significant increase in all CPTs at dermatomes T9 and L2. Alterations in CPTs were similar for both groups at T9 but were significantly greater in patients given 2% lidocaine than in those given 1% lidocaine at L2. There were no differences in the upper level of sensory block to cold, pinprick, and touch between the two groups. We conclude that lumbar epidural anesthesia with 10 mL of 2% lidocaine produces more intense blockade of both large- and small-diameter sensory nerve fibers than that with 20 mL of 1% lidocaine.

IMPLICATIONS

The effects of local anesthetic concentration and volume on the quality of epidural anesthesia have not been adequately investigated. The results of the present study suggest that the concentration affects the intensity of sensory block during epidural anesthesia with lidocaine.

Analysis of serum cytokine levels in primary biliary cirrhosis patients and healthy adults

By using commercially available ELISA kits, serum IL-6 and TNF-alpha levels in healthy adults, and the levels of various cytokines in patients with primary biliary cirrhosis or chronic viral liver diseases, were investigated. IL-6 levels of healthy subjects were distributed in a wide range, and the distribution pattern was similar to those of the patients. TNF-alpha levels tended to be low in females in their 30s, but there were no abnormalities in the patients. Characteristic findings, in the primary biliary cirrhosis patients, were an increase of IFN-gamma and IL-2 levels, and a decrease of GM-CSF levels (P < 0.05). IL-8 levels were higher in the patients than in the healthy subjects (P < 0.05), and the increase was remarkable in chronic viral liver disease patients. We believe that measurement of serum cytokine levels as a clinical immunological test is highly useful. Further development of simpler, more rapid, and more sensitive analysis methods is desired.

Interaction of intrathecally infused morphine and lidocaine in rats (part I): synergistic antinociceptive effects

BACKGROUND

Synergistic antinociception of opioids and local anesthetics has been established in bolus injections but not in long-term use. The somatic and visceral antinociceptive effects of intrathecally infused morphine or lidocaine were characterized, and the nature of the interaction of those agents in rats was evaluated.

METHODS

Intrathecal catheters were implanted in rats. Morphine (0.3 to 10 microg x kg(-1) x h(-1)), lidocaine (30-1,000 microg x kg(-1) x h(-1)), a combination of those, or saline was infused intrathecally at a constant rate of 1 microl/h for 6 days. The tail flick and colorectal distension tests were used to measure the somatic and visceral antinociceptive effects, respectively. Nociceptive tests and motor function tests were repeated on days 1, 2, 3, 4, and 6. Isobolographic analysis was performed on the results of the tail flick test to determine the magnitude of the interaction.

RESULTS

Intrathecally infused morphine produced dose-dependent antinociceptive effects in both the tail flick and the colorectal distension tests. Morphine showed a lower peak percentage maximum possible effect (%MPE) in the colorectal distension test than in the tail flick test. Intrathecal lidocaine also produced dose-dependent antinociceptive effects. Lidocaine infusion at 1,000 microg x kg(-1) x h(-1) caused motor impairment. Coinfusion of morphine 0.3 microg x kg(-1) x h(-1) and lidocaine 200 microg x kg(-1) x h(-1), which had no effects by themselves, significantly increased the percentage maximum possible effects (P < 0.01). Coinfused lidocaine potentiated the duration and the magnitude of morphine antinociception. Isobolographic analysis of the tail flick test on day 1 showed a synergistic interaction between morphine and lidocaine.

CONCLUSIONS

Morphine and lidocaine intrathecally coadministered synergistically potentiated the antinociceptive effects of each other. That coinfusion dramatically potentiated visceral antinociception, whereas the infusion of morphine alone showed little visceral antinociception.

Interaction of intrathecally infused morphine and lidocaine in rats (part II): effects on the development of tolerance to morphine

BACKGROUND

There has been little information regarding the effects of local anesthetics on tolerance to opioids, although chronic use of combination of opioids and local anesthetics is popular for pain control. This study was designed to examine the effects of lidocaine on morphine tolerance to somatic and visceral antinociception.

METHODS

Rats received a continuous intrathecal infusion of morphine (0.3-10 microg x kg(-1) x h(-1)), lidocaine (30-1000 microg x kg(-1). h(-1)), a combination of those, or saline. After 6- day infusion, intrathecal morphine challenge test (5 microg/10 microl) was performed, and time-response curve was constructed to assess the magnitude of tolerance. The tail flick (TF) test and colorectal distension (CD) test were used to measure somatic and visceral antinociceptive effects, respectively.

RESULTS

Antinociceptive effects in the TF and CD tests caused by morphine challenge were reduced (P < 0.01) in the morphine infused groups. The magnitude of the tolerance was inversely associated with the amount of morphine infused. Lidocaine infusion induced no different change in the morphine challenge test from that seen in the saline infusion group. Development of tolerance was greater in morphine 3 microg x kg(-1) h(-1) than in morphine 0.75 microg x kg(-1) x h(-1) + lidocaine 150 microg x kg(-1) x h(-1) despite their similar antinociceptive effects during intrathecal infusion. The infusion of a low dose of morphine (0.3 microg kg(-1) x h(-1)) did not reduce the antinociceptive effects in the challenge test.

CONCLUSION

Lidocaine in combination with morphine does not reduce tolerance to morphine nor develop cross-tolerance. The intrathecal infusion of morphine induced tolerance to somatic and visceral antinociception in a dose-dependent fashion.

Characteristics of tolerance to somatic and visceral antinociception after continuous epidural infusion of morphine in rats

A continuous epidural infusion of morphine may cause a complicated tolerance to develop, depending on the spinal and supraspinal sites. We designed this study to clarify the characteristics of the tolerance to somatic and visceral antinociception after epidural morphine infusion. Rats received epidural infusion of morphine at the rates of 50 or 100 microg kg(-1) h(-1), or isotonic sodium chloride solution for 7 days. The tail-flick (TF) test and colorectal distension (CD) test were used to measure the somatic and visceral antinociceptive effects, respectively. Nociceptive tests were performed on Days 1, 2, 3, 4, and 7. After 7 days, time-response curves after epidural morphine (10 microg) or intraperitoneal morphine (3 mg) challenge tests were conducted to assess the magnitude of tolerance. Epidurally infused morphine significantly increased percent maximal possible effects (%MPEs) (P < 0.05) in both the TF and CD tests, depending on the concentration of morphine. In the epidural morphine challenge test, increases in %MPEs were significantly attenuated (P < 0.05) in the morphine-infused group compared with the isotonic sodium chloride solution-infused group. The increases in %MPEs in the intraperitoneal challenge test were also attenuated in the morphine-infused group. We conclude that morphine tolerance to both somatic and visceral antinociception develops rapidly during epidural infusion and is based on the development of tolerance at the systemic, as well as the epidural, level.

IMPLICATIONS

A continuous epidural infusion of morphine rapidly induces tolerance to visceral and somatic antinociception in rats. This development is based on the development of tolerance at the systemic, as well as the epidural, level.

Quantitative and selective assessment of sensory block during lumbar epidural anaesthesia with 1% or 2% lidocaine

We have examined sensory block during lumbar epidural anaesthesia using a cutaneous current perception threshold (CPT) sensory testing device in 20 patients who received 10 ml of either 1% or 2% lidocaine (lignocaine). CPT at 2000, 250 and 5 Hz stimulation at the trigeminal (V), ninth thoracic (T9) and second lumbar (L2) dermatomes, and dermatomal levels of block to light touch, temperature and pinprick discrimination were measured before and every 5 min until 60 min after epidural lidocaine. There were significant differences between 1% and 2% epidural lidocaine in all CPT at T9 and L2, in addition to maximal cephalad spread of the three sensory modalities. After 2% lidocaine, all CPT increased significantly at T9 and L2. In contrast, only at 250 and 5 Hz for L2 did epidural block with 1% lidocaine produce significant increases in CPT. Maximal level of loss of touch sensation after 1% lidocaine was significantly lower than that of cold and pinprick sensations. We conclude that the dose of lidocaine affected intensity of sensory block during lumbar epidural anaesthesia. In addition, differential neural block resulting from epidural anaesthesia appeared to be associated with a differential effect on nerve fibres of different sizes.

The advantages of the lateral decubitus position after spinal anesthesia with hyperbaric tetracaine

We investigated the effects of lateral decubitus positioning after spinal anesthesia with hyperbaric tetracaine on the spread of sensory blockade and hemodynamic variables. One hundred ASA physical status I or II patients scheduled for elective surgery to the lower limb received spinal anesthesia at a rate of approximately 0.1 mL/s using 0.5% tetracaine in 7.5% glucose with 0.125% phenylephrine in the lateral decubitus position with the operated side dependent. They were randomly divided into three groups: patients in Group I were placed supine immediately after spinal injection; those in Group II remained in the lateral position for 10 min before being turned supine; those in Group III were kept in the lateral position for 20 min then turned supine. Neural block was assessed by cold, pinprick, and touch sensation, and a modified Bromage scale. Hemodynamic variables included blood pressure, heart rate, and the use of ephedrine for the treatment of hypotension. The median (10th, 90th percentiles) peak dermatomal level to pinprick on the dependent side in Group III was T8 (T11, T5), which was significantly lower than that in Groups I and II, which extended to T4 (T9, T3) and T5 (T10, T2), respectively (P < 0.05). The difference in the maximal cephalad spread of sensory blockade between both sides in Group III was only one dermatome but was statistically significant (P < 0.05); in contrast, there was no significant difference in the maximal sensory level between both sides in Groups I and II. The use of ephedrine for the treatment of hypotension was significantly less frequent in Group III than the other groups. We conclude that keeping a patient in the lateral decubitus position for 20 min after hyperbaric tetracaine spinal anesthesia maintains preferential anesthetic distribution to the dependent side. Despite small differences between the two sides, the restricted spread of blockade and less hemodynamic variability may be clinically advantageous.

IMPLICATIONS

The effects of posture on the spread of hyperbaric spinal anesthesia have not been adequately investigated. The results of the present study suggest an advantage of prolonged lateral decubitus positioning after intrathecal hyperbaric tetracaine.

Translocation (10;12)(q24;q15) in a T-cell lymphoblastic lymphoma with myeloid hyperplasia

We present a case of childhood T-cell lymphoblastic lymphoma (T-LBL) with a translocation (10;12)(q24;q15) as a main clonal abnormality, which to our knowledge is the first reported karyotype of this malignancy. The patient's peripheral blood and bone marrow showed marked leukocytosis mostly myeloid lineage cells, at diagnosis. The enlarged lymph node consisted of two different cell populations: CD2+/CD7+ prothymic lymphoblasts and a cluster of peroxidase-positive myeloid cells around vessels. This case might represent a rare but distinct clinical entity of LBL.

Antinociceptive effects of intrathecal L-type calcium channel blockers on visceral and somatic stimuli in the rat

L-type calcium channels can modulate neuronal transduction in the spinal cord. However, their role in noxious information processing in animals that are physiologically intact has not been elucidated. We evaluated the effects of L-type calcium channel blockers diltiazem and verapamil on somatic and visceral nociception at the level of the spinal cord. Intrathecal catheters were inserted at the L4-5 level in Sprague-Dawley rats. The tail flick (TF) test and colorectal distension (CD) test were used to assess somatic and visceral antinociceptive effects, respectively. Motor function was assessed by posture and muscle tone in the limbs. TF latency and CD threshold were measured before and for 180 min after the intrathecal administration of verapamil (50, 100, 300, and 500 microg), diltiazem (100, 300, 500, and 1000 microg), or isotonic sodium chloride solution. The percent maximal possible effect (%MPE) was calculated by transforming response threshold in TF and CD tests. Intrathecally administered diltiazem or verapamil increased both TF latency and CD threshold in a dose-dependent fashion. Isotonic sodium chloride solution, diltiazem 100 microg, and verapamil 50 microg did not increase %MPE in either test. Diltiazem 300 or 500 microg or verapamil 300 or 500 microg significantly (P < 0.05) increased %MPE, with the peak effects 5 min after administration and short-duration antinociception. %MPE was 100% until 15 min after the administration of diltiazem 1000 microg, and significant antinociception continued until 180 min in the TF test. Motor paralysis was observed after the administration of the larger dose of each drug. We demonstrated that intrathecally administered L-type calcium channel blockers diltiazem or verapamil produced both somatic and visceral antinociception and motor block dose-dependently.

IMPLICATIONS

We examined the effects of intrathecally administered L-type calcium channel blockers diltiazem and verapamil on somatic and visceral nociception in rats. L-type calcium channel blockers produced antinociceptive effects, suggesting a possible clinical application to control pain.

Detection of nivalenol genotoxicity in cultured cells and multiple mouse organs by the alkaline single-cell gel electrophoresis assay

We tested the genotoxicity of nivalenol (NIV), a potent toxic trichothecene from Fusarium nivale, in cultured CHO cells and in several mouse organs and tissues (liver, kidney, thymus, bone marrow and mucosa of stomach, jejunum, and colon) using the alkaline single-cell gel electrophoresis (SCG, or Comet) assay. NIV at 50 and 100 micrograms/ml damaged the nuclear DNA of CHO cells in the absence of S9 mix, showing that NIV was a direct mutagen. In an in vivo study, mice were sacrificed 2, 4, and 8 h after either oral (20 mg/kg) or intraperitoneal (3.7 mg/kg) administration of NIV. DNA damage was measured by the SCG assay as modified by us. After oral dosing, DNA damage appeared in the kidney and bone marrow at 2 h (returning to almost control level within the following 2 h), and in the stomach, jejunum, and colon at 2, 4, and 8 h, respectively. Liver and thymus DNA were not damaged. After intraperitoneal injection, no DNA damage appeared in any of the organs or tissues tested except for the colon, where extensive DNA damage was observed, as in the oral study, at 8 h. For histopathological examination, mice were sacrificed 2, 4, and 8 h after oral (20 mg/kg) administration of NIV. No necrotic changes were detected in any of the organs where NIV yielded statistically significant DNA damage. To measure the effect of NIV on transport activity in mice, 10 ml/kg (same volume as NIV treatments) of 1% brilliant blue FCF (BB) was administered orally. Thirty minutes later, the BB reached the colon, and simultaneous oral administration of NIV (20 mg/kg, dissolved in 10 ml BB solution) did not affect the dye transport rate. Thus, the strong yet delayed damage to colon DNA may follow from a systemic absorption rather than a topical effect. As a direct mutagen, NIV showed organ specific genotoxicity in mice in time and intensity.

Detection of pyrimethamine-induced DNA damage in mouse embryo and maternal organs by the modified alkaline single cell gel electrophoresis assay

We studied the embryonic and maternal genotoxicity of pyrimethamine (PYR), a potent teratogen and folate antagonist, using alkaline single cell gel electrophoresis (SCG, or Comet) assay as modified by us (we used isolated nuclei instead of isolated cells). ICR mice were treated on the 13th day of pregnancy with a single oral dose of 50 mg PYR/kg. Six maternal organs (liver, kidney, lung, brain, spleen, bone marrow), maternal and fetal placentas, and two embryos were taken 6 and 16 h after treatment; the embryos were divided into head and body portions. Each sample was minced, homogenized gently, and centrifuged. The nuclei from the precipitates were used. PYR induced DNA damage in all maternal organs except spleen and bone marrow 6 h after administration. The DNA damage in all the affected organs was less at 16 h than at 6 h, and that of the kidney and brain returned to control level at 16 h. PYR also induced DNA damage in maternal and fetal placentas and embryos that was detected at 6 and 16 h, with greater damage at 6 h. Co-treatment of folinic acid calcium salt (FNA, 10 mg/kg ip), a reduced active folate form, prevented the PYR-induced DNA damage in all target tissues examined 6 h after treatment. These data indicate that the observed embryonic and maternal DNA damage caused by PYR may be related to folate deficiency, and that the modified alkaline SCG assay can be used to predict fetal/embryonic genotoxicity in vivo, in addition to the organ-specific maternal genotoxicity.

[Quantitative assessment of differential nerve block during lumbar epidural anesthesia]

The study was performed to evaluate differential neural blockade during lumbar epidural anesthesia with a cutaneous current perception threshold (CPT) sensory testing device. Fourteen patients undergoing elective gynecological surgery received 10 ml of 2% lidocaine through an epidural catheter inserted at the L 1/2 interspace. CPTs at 2000, 250, and 5 Hz stimulation and sensation to light touch, temperature, and pinprick at ipsilateral dermatomes V, Th 9, and L 2 were measured before and every 5 min, until 60 min after the epidural lidocaine. The epidural block caused a significant increase in all CPTs at dermatome L 2 and in CPTs at 250 and 5 Hz at Th 9. Touch sensation at Th 9 was intact during the study period in 12 patients, most of whom lost sensation to the other stimulus: 12 patients did not respond to the cold stimulus and 10 patients to the pinprick. At L 2, sensory block to light touch, temperature, and pinprick was found in 11, 14, and 14 patients, respectively. There was no effect on any measurements made at V. In conclusion, epidural lidocaine results in a differential neural blockade as measured with CPT testing. Since the 2000-Hz stimulus detect abnormalities that correlate with large fiber functioning, it is suggested that loss of touch sensation is associated with effects of epidural lidocaine on large fibers.

Elevation of the serum Fas ligand in patients with hemophagocytic syndrome and Diamond-Blackfan anemia

Fas ligand (FasL) is a membrane protein that is expressed in activated T cells and natural killer cells. FasL binds to Fas on target cells and induces apoptosis. There exists a soluble form of FasL (sFasL), and sFasL also induces apoptosis of Fas-bearing cells. The serum sFasL concentrations were reported to be elevated in patients with large granular lymphocytic leukemia and natural killer cell lymphoma. In this study, we have measured serum sFasL concentrations in other hematological disorders, including severe aplastic anemia (SAA), hemophagocytic lymphohistiocytosis (HLH), and Diamond-Blackfan anemia (DBA). The serum sFasL concentration of age-matched healthy controls was 0.16 +/- 0.11 ng/mL (mean +/- SD, n = 22). The serum sFasL levels in the patients with HLH and DBA were 3.75 +/- 3.82 (n = 19; P < .0001, HLH v control) and 2.76 +/- 2.43 ng/mL (n = 6; P = .012, DBA v control), respectively. Serum interferon-gamma concentration was elevated in the patients with HLH (1.61 +/- 2.62 ng/mL) but not in those with DBA (below the detectable level). These results suggest that the Fas-FasL system plays a role, at least in part, in the pathophysiology of HLH and DBA.

[Circulatory collapse during laparoscopic cholecystectomy]

A 52 year-old female without any cardiac disease underwent laparoscopic cholecystectomy. Anesthesia was induced with thiamylal and maintained with nitrous oxide and isoflurane. Epidural anesthesia was also used during surgery. When the intraabdominal insufflation was performed in reverse-trendelenburg position 15 minutes after the start of incision, the heart rate suddenly decreased from 75 to 49 bmp with a fall in blood pressure. Her hemodynamic state recovered immediately after the release of intraabdominal pressure and the administration of ephedrine with a rapid infusion of Hespander. The circulatory collapse did not occur when the second insufflation was tried carefully. The circulatory collapse was probably due to the vagal reflex. The decrease in cardiac preload during the reverse trendelenburg position and the epidural administration of local anesthetics may have caused or worsened the circulatory collapse. In anesthetic managements of laparoscopic cholecystectomy using general anesthesia with epidural anesthesia, prophylactic hydrogenation and prevention of parasympathetic domination are important to minimize the vagal reflex.

Microparticle resins as a potential nasal drug delivery system for insulin

The application of various resins for the nasal delivery of insulin was examined in rabbits. Intranasal administration of human insulin (28 U, 1 mg) mixed with fractionated sodium polystyrene sulfonate powder (an anionic resin with a particle size of 20-45 microns) caused a rapid increase of the plasma insulin level 413.0 +/- 71.7 microU/ml (mean +/- S.D.) after 15 min, while intranasal administration of insulin alone caused little increase. The blood glucose level decreased from 118.8 +/- 18.5 mg/dl to 65.8 +/- 13.8 mg/dl at 45 min after administration. These results were superior to those obtained with the unfractionated resin. Styrene-divinylbenzene copolymer (a nonionic resin; 20-45 microns fraction) showed similar enhancement of nasal insulin absorption. In contrast, polyacrylester (a nonionic resin; 20-45 microns fraction) and cholestyramine (a cationic resin) did not promote insulin absorption. These results suggest that some resins may be useful for nasal delivery of insulin.

Anaesthetic management of caesarean section in a patient with myelodysplastic syndrome

PURPOSE

This case report describes the anaesthetic management for Caesarean section in a patient with myelodysplastic syndrome.

CLINICAL FEATURES

A woman with myelodysplastic syndrome underwent Caesarean section on two occasions. The first Caesarean section was performed at age 20 yr using general anaesthesia with nitrous oxide-oxygen and fentanyl. In her second pregnancy at 25 yr, there was severe pancytopenia at 28-wk gestation with a leukocyte count 3.6 x 10(9).L-1, erythrocyte count 1.2 x 10(12).L-1, haemoglobin 50 g.L-1, haematocrit 14.7% and platelet count 51 x 10(9).L-1. Following leukocyte poor red cells and platelet transfusion, general anaesthesia was maintained with nitrous oxide-oxygen-sevoflurane and fentanyl. Both operations were uneventful and healthy infants were delivered.

CONCLUSION

It is important to have a team approach (anaesthetist, obstetrician and haematologist) for the perianaesthetic management of patients with myelodysplastic syndrome. An exact assessment of the haematological condition, the need for prophylactic treatment and anaesthetic management should be determined for each individual patient.

[Measurement of functional residual capacity by nitrogen washout during mechanical ventilation]

A medical gas analyzer AMIS 2000 SP, which is a mass spectrometer, incorporating a fractional residual capacity (FRC) measuring program based on a nitrogen washout method, has been introduced recently. The purpose of this study was to assess the reliability and the reproductivity of the FRC measuring system in a clinical situation. FRC was measured by this system connected to a ventilator (Bennet 7200ae). Our study examined; 1) the accuracy of the measurement using a syringe. 2) the difference in two consecutive measurements in the same subject during mechanical ventilation, and 3) the correlation between the measured and the predicted value calculated with Gorldman's formula in 18 subjects during ventilation. The first study has showed an excellent correlation (y = 0.953x + 0.092, r = 0.996, P < 0.001) or y = 0.909x + 0.132 (r = 0.999, P < 0.001) with a tidal volume of 400 ml or 500 ml, respectively) between the measured value and the syringe capacity. Reproductivity was proved by the linear regression (y = 0.977x + 0.024, r = 0.998, P < 0.001) between the two consecutive measurements. A good correlation was shown between the measured values and the predicted values (y = 0.656x - 0.415, r = 0.849, P < 0.0001). These results showed good reliability and reproductivity of our FRC measuring system. It is concluded that the FRC measurements using AMIS2000SP system can be used in clinical respiratory managements in ICU.