Characteristics of invasive Acinetobacter species isolates recovered in a pediatric academic center

Background

Acinetobacter species are associated with increasing mortality due to emerging drug-resistance. Pediatric Acinetobacter infections are largely undefined in developed countries and clinical laboratory identification methods do not reliably differentiate between members of the Acinetobacter calcoaceticus-baumannii complex, leading to improper identification. Therefore we aimed to determine risk factors for invasive Acinetobacter infections within an academic, pediatric setting as well as defining microbiologic characteristics of predominant strains.

Methods

Twenty-four invasive Acinetobacter isolates were collected from 2009–2013. Comparative sequence analysis of the rpoB gene was performed coupled with phenotypic characterization of antibiotic resistance, motility, biofilm production and clinical correlation.

Results

Affected patients had a median age of 3.5 years, and 71 % had a central catheter infection source. rpoB gene sequencing revealed a predominance of A. pittii (45.8 %) and A. baumannii (33.3 %) strains. There was increasing incidence of A. pittii over the study. Two fatalities occurred in the A. pittii group. Seventeen percent of isolates were multi-drug resistant. A pittii and A. baumannii strains were similar in motility, but A pittii strains had significantly more biofilm production (P value = 0.018).

Conclusions

A. pittii was the most isolated species highlighting the need for proper species identification. The isolated strains had limited acute mortality in children, but the occurrence of more multi-drug resistant strains in the future is a distinct possibility, justifying continued research and accurate species identification.

Electronic supplementary material

The online version of this article (doi:10.1186/s12879-016-1678-9) contains supplementary material, which is available to authorized users.

The relationship between motor competence, physical fitness and self-perception in children

AIM

The aim of the current research was to explore the relationship between motor competence, physical fitness and self-perception, and to study to which extent this relationship may vary by gender.

METHODS

A sample of 67 children (mean age 11.46 years, SD 0.27) completed Harter's Self-Perception Profile for Children (SPPC), the Movement Assessment Battery for Children (MABC) and the Test of Physical Fitness (TPF) to assess self-perception, motor competence and physical fitness.

RESULTS

The SPPC was stronger related to total score on TPF than to total score on MABC. However, when looking at boys and girls separately, this result was found for the boys only. In the group in general, total scores on both TPF and MABC correlated significantly with three of the domains of SPPC (social acceptance, athletic competence and physical appearance) and general self-worth. This relationship varied by gender. Interestingly, TPF was highest correlated with perception of athletic competence in boys but with perception of social acceptance in girls. A high and significant correlation was found between physical fitness and motor competence for both genders.

CONCLUSION

The results indicated a strong relationship between physical fitness, motor competence and self-perception in children that varied by gender. This implies that all these factors are essential contributions in order to facilitate participation in physical activity in children.

Research on children with developmental coordination disorder--some challenges! Commentary on C. L. Tsai and S. K. Wu (2008)

This commentary focuses on the need for proper inclusion criteria for research on children who have motor problems. Researchers must be aware of the large range of individual differences found in samples used in research on children with Developmental Coordination Disorder. New theoretical perspectives in development and learning are a basis for research and practice.

The relationship between physical fitness and motor competence in children

BACKGROUND

This study examined the relationship between physical fitness and motor competence in children aged 9-10 years.

METHODS

A sample of 67 children (mean age 9.7, SD 0.3 year) participated in the study. To assess motor competence, each child completed the Movement Assessment Battery for Children. Physical fitness was measured by the Test of Physical Fitness, comprising nine different tasks including running, jumping, throwing and climbing.

RESULTS

The results show a strong and significant correlation between motor competence and physical fitness within the sample.

CONCLUSIONS

These results are relevant to the work of maintaining and developing both sufficient physical fitness and motor competence in children as these factors are important contributors to their health and well-being.

Interrelationship among selected measures of motor skills

BACKGROUND

This study set out to explore the interrelationship among selected measures of motor skills.

METHODS

Ninety-one 4-year-old children from 10 nursery schools were tested using eight motor tasks from the Movement Assessment Battery for Children test.

RESULTS

The most striking finding was that there were very low correlations between the motor tasks.

CONCLUSIONS

In relation to these findings, it is possible to argue that learning of particular motor skills is specific to that task. This is discussed in relation to the principle of task specificity of learning.

[Vacuum-assisted wound closure in the management of deep sternal wound infection]

We herein present a case who underwent vacuum-assisted wound closure (VAC) therapy for post-sternotomy mediastinitis. A 71-year-old female with chronic renal failure on dialysis underwent a graft replacement of the ascending aortic aorta for the treatment of an acute aortic dissection. After she was discharged from the hospital, a purulent discharge was noted to occur from the median sternal wound. The wound was therefore reopened and all sternal wires were removed. Thereafter, polyurethane foam which was shaped to fit the defect was placed within the cavity. The area was covered with adhesive drape and suction drainage was carried out at -100 mmHg. The polyurethane foam was replaced every few days. The wound was finally closed using a muscle flap at 49 days after surgery. VAC therapy is therefore considered to be a useful treatment modality for deep sternal wound infections.

Venous blood flow through vein grafts before harvesting minimizes endothelial cell desquamation immediately after implantation

AIM

The aim of this paper was to examine effectiveness of maintaining venous blood flow through dissected, but not harvested, grafts on prostaglandin I2 production and endothelial cell regeneration after implantation.

METHODS

Using 10 dogs, 8-cm-long bilateral jugular veins were dissected; 1 was harvested, and immersed in heparinized blood for 60 or 120 min. The other was left in situ with retained blood flow until harvest after 60 or 120 min. Two 1-cm-long specimens were obtained from these 4 graft types and subjected to PGI2 assay or silver nitrate staining for measurement of endothelial cell coverage area. The remaining 6-cm portions of the 120-min grafts were autogenously implanted into the abdominal aorta, retrieved after 7 days and assayed and measured.

RESULTS

Comparisons between groups suggested beneficial effects of preserving venous blood flow until implantation on endothelial coverage and PGI2 production (p<0.05).

CONCLUSION

Venous blood flow through dissected vein grafts effectively helps preserve PGI2 production.

[Venovenous extracorporeal membrane oxygenation in neonatal systemic artery-to-pulmonary artery shunt operations using a double lumen catheter]

The right atrium of the neonate may be too small for direct insertion of 2 venous catheters during intraoperative life support. We inserted a double lumen catheter into the right atrium, and venovenous (V-V) extracorporeal membrane oxygenation (ECMO) was instituted. The patient's arterial oxygen saturation was maintained at 70% to 90%, and hemodynamic stability was obtained during V-V ECMO. V-V ECMO using a double lumen catheter can be easily established in a small neonate, and is an effective support technique for untolerable hypoxemia during systemic-to-pulmonary artery shunt operations.

Systemic lupus erythematosus and the risk of malignancy

The objective of this study was to determine the relative risks of malignancy and of site-specific malignancies in patients with systemic lupus erythematosus (SLE). A cohort of 297 patients (91% Caucasian) with SLE were seen between 1975 and 1994 and followed for a mean of 12 years at the University of Saskatchewan Rheumatic Disease Unit. Expected cancer incidence rates were determined based on Province of Saskatchewan population statistics matched to each study patient for age, sex and calendar year of follow-up. Standardized incidence ratios (SIRs) of observed to expected cancers and 95% confidence intervals (95% CI) were calculated. A total of 27 cases of cancer were observed, whereas only 16.9 were expected (SIR 1.59 (95% CI 1.05-2.32)). For site-specific malignancies, an excess of cancer of the cervix (SIR 8.15 (95% CI 1.63-23.81)) as well as hemopoietic malignancy (SIR 4.9 (95% CI 1.57-11.43)) was found. The hemopoietic cancers were predominantly non-Hodgkin's lymphoma (SIR 7.01 (95% CI 1.88-17.96)). We did not find an association of malignancy with known risk factors, including use of cytotoxic agents. Increased risk of malignancy, notably non-Hodgkin's lymphoma and perhaps cervical cancer, should be regarded as a complication of SLE.

Successful implantation of a cardioverter defibrillator in an infant

We report the successful implantation of a cardioverter defibrillator (ICD) in a 12-month-old infant. A single-lead ICD using an epicardial patch and a cathodal pulse-generator titanium shell electrode was very useful for implantation in this infant.

Radiographic damage in rheumatoid arthritis correlates with functional disability but not direct medical costs

OBJECTIVE

Few longitudinal data exist on the relationship between radiographic damage and self-reported functional disability and direct medical costs in rheumatoid arthritis (RA). We assessed these relationships.

METHODS

One hundred thirty patients with RA (at time of the first available radiograph, mean age 56.6 yrs, 16.9% male, mean disease duration 16.8 yrs) were followed for up to 13.4 years. Semiannually, they reported on functional disability (0 = no difficulty, 3 = unable to do), global severity (0 = very well, 100 = very poor), pain (0 = no pain, 3 = severe pain), and health services utilization through completion of the Stanford Health Assessment Questionnaire (HAQ). Concurrent hand radiographs were scored for erosions and joint space narrowing using the Genant method and a single score summing both erosions and joint space narrowing for both hands was calculated (0 = no damage, 200 = maximum damage). The univariate association of functional disability, global severity, pain, or direct medical costs with concurrent radiographic damage was assessed through Spearman correlations and hierarchical regression models. The hierarchical models permit exploitation of the between-patient and within-patient variation present in our longitudinal data.

RESULTS

At the time of the first available radiograph, mean (SD) levels of functional disability, global severity, and pain were 1.3 (0.7), 39.4 (21.0), and 1.1 (0.7), respectively. At entry into the study, the average radiograph score was 49.7 and upon leaving the study it was 66.9. Patients were followed an average of 6.7 years, with radiograph scores increasing at an average rate of 2.5 units/yr. The Spearman correlation [95% confidence interval (CI)] between average per-patient radiograph score and average per-patient HAQ disability index, average per-patient global severity, average per-patient pain score, and average per-patient direct medical costs was, respectively, 0.42 (0.26, 0.55), 0.23 (0.06, 0.39), 0.20 (0.03, 0.36), and 0.06 (-0.11, 0.23). The mean slope (95% CI) for disability on radiograph score was 0.0186 (0.0132, 0.0226), for severity on radiographs 0.1889 (0.1295, 0.2498), and for pain on radiographs 0.0057 (0.0027, 0.0084). As an example, over 10 years, a 25 unit (i.e., 50%) increase in radiograph scores would, on average, be associated with a 0.46 unit (i.e., 35%) increase in disability, a 4.72 unit (12%) increase in global severity score, and a 0.14 unit (13%) increase in pain, all expressed on the HAQ scales. There was little association between radiograph score and direct medical costs.

CONCLUSION

A clinically meaningful association exists between radiographic damage and self-reported functional disability, suggesting that interventions that slow radiographic progression may improve the patient's health status. Such a relationship was not observed between radiographic damage and direct medical costs.

Active oxygen radicals induce peroxidase activity in rice blade tissues

The relationship between active oxygen radicals and peroxidase induction on disease resistance in rice blades was investigated. Nitric oxide was produced in the whole blade stimulated by blast fungus elicitor. The induction of peroxidase activity was detected in active oxygen radical-treated rice blades 1 hour after treatment and thereafter. These results suggest that active oxygen radicals produced by stimulation with the elicitor could trigger peroxidase induction.

Evaluation of an internal thoracic artery as a coronary artery bypass graft by intercostal duplex scanning ultrasonography

OBJECTIVES

Although angiography is often used to determine whether the internal thoracic artery is appropriate as a coronary bypass graft, but use of duplex scanning ultrasonography for this purpose is not yet widespread.

METHODS

The internal diameter and flow of the internal thoracic artery were measured using intercostal duplex scanning in 100 patients during April 1995. The ultrasonographic device (sonos 2000, Hewlett Packard) used had a linear probe delivering a frequency of 7.5 MHz. Bilateral internal thoracic arteries and their blood flow were imaged clearly in all subjects. Diameter was compared by angiography and duplex scanning ultrasonography in 20 patients.

RESULTS

The average internal diameter of internal thoracic artery was 2.19 +/- 0.46 mm (right) or 2.13 +/- 0.32 mm (left) in men and 2.05 +/- 0.44 mm (right) or 2.09 +/- 0.42 mm (left) in women. The gender difference was statistically significant (p = 0.05). The maximum systolic blood flow velocity through the internal thoracic artery was 0.85 +/- 0.34 m/s (right) or 0.84 +/- 0.36 m/s (left) in men and 0.87 +/- 0.28 m/s (right) or 0.82 +/- 0.28 m/s (left) in women. The average internal thoracic arterial blood flow (F) was 54.6 +/- 29.0 ml/min (right) or 50.9 +/- 28.8 ml/min (left) in men and 56.8 +/- 38.2 ml/min (right) or 58.2 +/- 33.4 ml/min (left) in women. Duplex scanning ultrasonography using an intercostal approach enables easy imaging of bilateral internal thoracic arteries and visualizes entire internal thoracic artery structure by simply changing the probe position.

CONCLUSION

Intercostal duplex scanning ultrasonography is thus recommended for reliable evaluation of the internal diameter and blood flow of the internal thoracic artery.

[Determination of 4-O-methylpyridoxine (MPN) by HPLC with diode-array detector]

We have developed a simple and rapid method for measuring 4-O-methylpyridoxine (MPN) in the serum of an acute poisoning patient by high-performance liquid chromatograph (HPLC) with a diode-array detector. MPN, a poisonous ingredient of ginkgo seeds was extracted using an Isolute C18 solid-phase extraction column. Equal volumes of the extract were injected into a C18 HPLC column using acetonitrile-10 mM phosphate buffer (pH 3) as the mobile phase. Excellent linearity was obtained over the range of 1-1000 ng at a wavelength of 290 nm, and its detection limit of approximately 0.5 ng was considered to be satisfactory. The mean recovery of MPN in the serum was 92.9 +/- 6.1%. The method was used successfully in a case of acute poisoning.

In vitro absorption and metabolism of a citrus chemopreventive agent, auraptene, and its modifying effects on xenobiotic enzyme activities in mouse livers

We previously reported that auraptene (7-geranyloxycoumarin, AUR), widely occurring in citrus fruit, is a structurally novel type of effective cancer-preventive agent, as manifested in several rodent models. However, its bio-availability and metabolism in biological systems have yet to be investigated. In the present study, we examined the chemical stability of AUR at pH 1.57 and 37 degrees C (as a stomach digestion model) and observed its stoichiometric conversion to umbelliferone [7-hydroxycoumarin, UMB; half-life (t1/2) = 15 h; 7-ethoxycoumarin (ETC) was stable for 24 h]. Differentiated Caco-2 cells, a human colorectal adenocarcinoma cell line, were used as a small intestine model. ETC permeated the basolateral (portal vein) side of Caco-2 cells in a time-dependent manner; AUR slightly permeated the cells, but with an intracellular accumulation. Epoxyauraptene and UMB were detected when AUR was treated with the rat liver S-9 mixture. ETC was also converted to UMB, but its t1/2 of two hours was much shorter than that of AUR (> 24 h). This suggests that AUR, bearing a geranyloxyl side chain, is a relatively metabolism-resistant substrate for cytochrome P-450 enzymes and, thus, is stable in the liver compared with ETC. Oral administration of AUR by gavage at 50-200 mg/kg body wt dose dependently induced glutathione S-transferase (GST) activity in mouse livers without affecting cytochrome P-450 activity. Using 10 coumarin-related compounds, we found that only those coumarins having a 7-alkyloxyl group induced GST, but not cytochrome P-450, activity. The present study presumes that AUR accumulates in the epithelial cells of the small intestine and then gradually permeates into the portal vein. Stable localizability of AUR in the colon and liver may be associated with the induction of GST activity, which is important as the action mechanism for suppression of rodent chemical carcinogenesis.

Ionotropic glutamate receptors expressed in human retinoblastoma Y79 cells

Mammalian retinal photoreceptors and pinealocytes have common characteristic that they secrete melatonin and L-glutamate as chemical transmitters. Although pinealocytes express glutamate receptors and receive glutamate signals, whether or not photoreceptors express glutamate receptors is unknown. Here, we investigated the expression of the glutamate receptors in cultured Y79 clonal human retinoblastoma cells, as model systems of photoreceptors. Reverse transcription-polymerase chain reaction (RT-PCR) analysis indicated that GluR1, GluR5, GluR7, EAA2, NR1, NR2A and NR2D mRNAs were present in the cultured cells. Northern analysis confirmed the presence of GluR7, EAA2, NR1, NR2A and NR2D mRNAs, while other mRNAs were under the detection limit. Addition of (RS)-alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid or kainate increases intracellular (Ca(2+)) in Fura-2 loaded cells, which is blocked by 6-cyano-7-nitroquinoxaline-2,3-dione. N-methyl-D-aspartate also increases intracellular (Ca(2+)). These results demonstrated the presence of functional ionotropic receptors in Y79 cells.

[Children and motor competence]

Recently, the topic of motor competence has figured prominently in the media. The claims made are many, but the research that support the statements is seldom cited. The aim of this review article is to address that deficiency by documenting what is really known about the motor competence of children. Motor competence not only allows children to carry out everyday practical tasks, but it is also an important determinant of their level of self-esteem and of their popularity and status in their peer group. While many studies have shown a significant correlation between motor problems and other problems in the social sphere, it has been difficult to establish causal relationships with any degree of confidence, as there appear to be several interactions which need to be taken into account. Research has shown that 6-10% of Norwegian children in the 7 to 10 year age group have a motor competence well below the norm. It is unusual for motor problems to simply disappear over time. In the absence of intervention the syndrome is likely to continue to manifest itself. More recent research points to some of the circularity in this causal network, children with motor problems having been shown to be less physically active than their peers. In a larger health perspective this in itself can have very serious consequences for the child.

Luminescent Langmuir-Blodgett films of platinum(II) complex [Pt(L18)Cl](PF6) (L18 = 2,6-bis(1-octadecylbenzimidazol-2-yl)pyridine)

A novel amphiphilic Pt complex containing 2,6-bis(1-octadecylbenzimidazol-2-yl)pyridine (L18), [Pt(L18)Cl](PF6), has been synthesized. The complex exhibits concentration-dependent absorption and emission spectra in solution. With increasing the concentration of the Pt complex, we observed a new absorption band centered at 550 nm derived from a metal-metal d sigma* to ligand pi* charge transfer (MMLCT) transition and the corresponding broad emission centered at 650 nm. The Pt complex is surface-active, and the surface pressure-area isotherm reveals three phase transitions. The three phases correspond to one liquid-expanding phase and two solid-condensed phases, respectively, with different intermolecular overlap in the "flat-on" orientation at the air-water interface. Without additives such as fatty acids, the complex forms a stable and reproducible Langmuir-Blodgett (LB) multilayer film above a surface pressure of 15 mN m-1. Strong emission from the LB films, even monolayer, was observed. Comparing the relative emission intensity of the MMLCT band for transferred LB monolayer film with that for cast films, we concluded that Pt-Pt interactions are suppressed in the LB film. Instead, the emission at 600 nm arising from the ligand-ligand pi-pi interacted excited state became dominant. The results would provide the insight into the control of molecular ordering for planar Pt complexes from the viewpoint of characteristic excited states.

Improvement of intestinal absorption of peptides: adsorption of B1-Phe monoglucosylated insulin to rat intestinal brush-border membrane vesicles

In a previous study we glycosylated insulin to improve its intestinal absorption. When the glycosylated product, p-(succinylamido)-phenyl-alpha-D-glucopyranoside (SAPG)-substituted insulin (SAPG-INS), was administered intra-intestinally to rats, it showed a greater hypoglycemic effect than native bovine insulin. The enhanced hypoglycemic effect of SAPG-INS was considered to be due to an increase in membrane permeability as well as an increase in resistance to enzymatic degradation. In particular, membrane permeability may be related to an interaction with the Na(+)-dependent D-glucose transporter (SGLT-1) which is located in the brush-border membrane of epithelial cells. The insulin product used in the previous study, however, comprised a mixture of mono-, di- and tri-SAPG-substituted insulin. In this study SAPG-INS with a defined substitution number and position was synthesized to examine the interaction between the transporter and glycosylated insulin in more detail. The new product was mono-SAPG-substituted insulin substituted at the B1-phenylalanine position (B1-SAPG-INS) and was selectively synthesized after protection of the A1-glycine and varepsilonB29-lysine amino acids. The hypoglycemic effect of B1-SAPG-INS in rats after an intravenous dose of 71 microg/kg was almost the same as that of native bovine insulin at a dose of 1 U/kg and B1-SAPG-INS retained about 60% of the immunoreactivity of native bovine insulin. The interaction of B1-SAPG-INS with the intestinal transporter was examined by a rapid filtration technique using (125)I-labeled B1-SAPG-INS and brush-border membrane vesicles (BBMVs) which were prepared from rat small intestine by the Mg-precipitation method. The amount of B1-SAPG-INS adsorbed or absorbed by BBMVs in the presence of an inward Na(+)-gradient into BBMVs was greater than that of native bovine insulin. This adsorption/absorption was significantly inhibited by the presence of 1 mM phloridzin. A similar inhibition was observed when Na(+) was replaced with K(+) and when B1-SAPG-INS was incubated with BBMVs at 4 degrees C. From the effect of osmolarity on the extent of adsorption/absorption, it was considered that B1-SAPG-INS was not taken up into the intravesicular space but adsorbed onto the external membrane surface of BBMVs. These findings suggested that B1-SAPG-INS was adsorbed specifically onto the transporter. The hypoglycemic effect of insulin was enhanced by glycosylation at the B1 position in in situ experiments using normal and diabetic rats. Consequently, it is suggested that B1-SAPG-INS was adsorbed specifically onto the glucose transporter of intestinal BBM. This specific adsorption may be involved in the mechanism of the enhanced hypoglycemic effect of B1-SAPG-INS both in normal and diabetic rats.

Postoperative delirium in patients with chronic lower limb ischaemia: what are the specific markers?

OBJECTIVES

we determined the incidence and specific markers of postoperative delirium in elderly patients with chronic lower limb ischaemia.

PATIENTS AND METHODS

since April, 1995, 110 patients aged 60 years or older (mean: 71.6+/-6.6 years) who underwent bypass surgery were assessed regarding aetiological factors of delirium: age, sex, dementia, body-mass index, hypertension, diabetes, cerebral disease, laboratory test results, severity of limb ischaemia, type of arterial occlusion, operative time, and blood transfusion.

RESULTS

discriminant analysis showed statistical significance in the following five variables: age >/=70 years; critical limb ischaemia (and/or ankle pressure <40 mmHg); dementia; duration of operation >/=7 hours; low serum albumin. The overall percentage of cases correctly classified was 78.2% (Wilks>> Lambda=0.695, p<0.001); the standardized regression coefficients of the five variables were 0.648, 0.500, 0.329, 0.218, and 0.200, respectively. In logistic regression, the regression coefficients for old age and critical limb ischaemia were 2.646 (14.1 of odds ratio; 95% confidence interval, 2.7-72.0) and 1.337 (3.8; 1.3-10.9), respectively.

CONCLUSIONS

the incidence of postoperative delirium in elderly patients with chronic lower-limb ischaemia was as high as 42.3%, and an age of over 70 years and critical limb ischaemia were identified as specific markers, with 14.1 times and 3.8 times the odds of suffering from delirium after bypass surgery.

Anti-CD2 monoclonal antibodies prevent the induction of experimental autoimmune myocarditis

We investigated the effect of a monoclonal antibody against CD2 molecules (OX34) in preventing the induction of experimental autoimmune myocarditis (EAM) induced by immunizing Lewis rats with cardiac myosin. Administration of OX34 before immunization, on Days -6, -4, -2 and 0, completely prevented EAM. On the other hand, treatment with OX34 just before the appearance of myocardial lesions, on Days 9, 11, 13 and 15, had only a partial effect in preventing the disease. Flow cytometric analysis of lymph node cells showed that CD3+ T cells were immediately depleted with the administration of OX34 but had largely recovered on Day 21. Lymph node cells in OX34-treated rats had no proliferative responses to cardiac myosin-rod, but the proliferation was restored when recombinant IL-2 was added. Ultimate production of the anti-myosin antibody was not inhibited by the treatment with OX34. These results suggest that the prevention of EAM by administering the anti-CD2 monoclonal antibody OX34 resulted from T cell depletion during the induction phase, and might in addition result from T cell anergy of Th1, but not Th2 cells.

Bilobalide prevents reduction of gamma-aminobutyric acid levels and glutamic acid decarboxylase activity induced by 4-O-methylpyridoxine in mouse hippocampus

We previously reported that bilobalide, a constituent of Ginkgo biloba L. leaves, protected mice against convulsions induced by 4-O-methylpyridoxine (MPN). To elucidate the mechanism of the anticonvulsant activity of bilobalide, this study examined the effect of bilobalide on MPN-induced changes in the levels of gamma-aminobutyric acid (GABA) and glutamate, and in the activity of glutamic acid decarboxylase (GAD) in the hippocampus, cerebral cortex and striatum of the mouse. GABA levels and GAD activity in the hippocampus and cerebral cortex were significantly enhanced by bilobalide treatment (30 mg/kg, p.o., for 4 days) alone. MPN significantly decreased GABA levels and GAD activity in the three brain regions tested compared with those in the control. Pretreatment with bilobalide effectively suppressed the MPN-induced reduction in GABA levels and GAD activity in the hippocampus and cerebral cortex. On the other hand, there were no significant differences in the glutamate levels in the three regions despite various treatments. These results suggested that bilobalide prevents MPN-induced reduction in GABA levels through potentiation by bilobalide of GAD activity, and this effect of bilobalide contributes to its anticonvulsant effect against MPN-induced convulsions.

Synergistic effect of anti-T cell receptor monoclonal antibody and 15-deoxyspergualin on cardiac xenograft survival in a mouse-to-rat model

BACKGROUND

Successful xenograft transplantation faces several obstacles including the presence of xenoantibodies, natural killer cell- and macrophage-mediated rejection, and T lymphocyte activation.

METHODS

A mouse-to-rat cardiac xenograft model was used to examine the synergistic effect of anti-T cell receptor (TCR) monoclonal antibodies (mAb) and 15-deoxyspergualin (DSG) on graft survival.

RESULTS

Pretransplantation injections (days -5, -3, and -1) of anti-TCR mAb (500 microg/kg/day) combined with continuous i.p. infusion of DSG (5 mg/kg/day) from day -7 to 28 significantly prolonged graft survival compared to untreated controls (3.3+/-0.5 vs. 44.2+/-5.6 days, P<0.001). Postoperative splenectomy combined with discontinuation of all other treatment on day 28 enhanced graft survival in rats treated with anti-TCR mAb and DSG to 71.0+/-2.5 days. Histological examination of grafts showed characteristic signs of vascular rejection: interstitial edema and hemorrhage, and polymorphonuclear cell infiltration. Antimouse antibody titers in recipients were increased upon rejection in each group that received a xenograft. Flow cytometry analysis showed a markedly decreased T cell population and a relatively increased mature B cell population (IgM(bright)/IgD(dull)) in spleens of rats treated with anti-TCR mAb and DSG on day 28.

CONCLUSIONS

The mechanism of prolonged xenograft survival in this model may include inhibition of antibody production by arrest of B-cell maturation during development from IgM(dull)/IgD(bright) mature B cells to antibody producing cells, and inhibition of T cell activation. The rejection seen in our model may be caused by xenoreactive antibodies and may be associated with T cells, natural killer cells, and macrophages.

An experience of a case with perforation of an aneurysm in the anterior mitral cusp developing after aortic valve replacement

Mitral valve aneurysm is a rare disease and in Japan, cases of perforation which is considered to be mainly caused by infectious endocarditis is usually only encountered through case reports. We experienced a case who received aortic valve replacement and mitral valve annuloplasty for combined valvular heart disease of aortic insufficiency and mitral insufficiency followed by mitral valve replacement for severe mitral valve regurgitation subsequent to perforation of the anterior mitral cusp, leading to recovery.

Outbreak of cryptosporidiosis after contamination of the public water supply in Saitama Prefecture, Japan, in 1996

An outbreak of cryptosporidiosis occurred in Ogose Town, Saitama Prefecture. Japan, in June 1996. Of 12,345 respondents to a questionnaire sent to households in the town (population; 13,809), 8,812 (71.4%) reported an acute gastrointestinal illness some time between May and July. In addition, 274 traceable visitors at local inns, golf courses, and the like during this period and 54 employees from out of town were infected. Cases of cryptosporidiosis were estimated to 9,140. Of these, 2,856 subjects were treated at outpatient clinics and 24 subjects were hospitalized (some subjects counted twice). No deaths were attributed to the outbreak. Among the visitors to Ogose who were traced, 7 persons who stayed only one day during the outbreak and drank half a glass to 2 glasses (100 to 360 ml) of tap water had cryptosporidiosis confirmed by laboratory tests. The median incubation period for the 14 persons for whom this calculation was possible was 6.4 days (range, 5 to 8 days). Of 469 pupils reporting details of their fever and diarrhea, abdominal cramps, or these combined signs and symptoms, the median maximum body temperature was 37.8 degrees C (range, 36.7 to 40.3 degrees C). The duration of illness, reported by 608 of the pupils, was 5.2 days (range, 1 to 15 days), and that reported by 187 employees was 4.8 days (range, 1 to 18 days). The longest known time for discharge of oocysts after onset was 44 days. Blood was not found in the 609 stool specimens examined. The outbreak was caused by contamination of the town's potable water by Cryptosporidium parvum oocysts. The town's water treatment plant treated river water by coagulation, sedimentation, sand filtration, and chlorination. Contamination arose because of various natural and artificial factors: one was that the monthly precipitation in May was much lower than average, causing the river water level to drop. Another factor was heavy rainfall one night in May that increased water turbidity. The amounts of the coagulant added seemed to be insufficient. There are two inns, three public lavatories, and two small-scale wastewater treatment plants upstream 400 m and 1,200 m of the intake point of the town's water treatment plant. However, there are no farms with livestock in the area. We suggest that the location of the water treatment facilities was inappropriate, and that oocysts had circulated from the potable water to humans to sewage to the river and back to the potable water.

Thoracic aortic aneurysm complicated with severe coronary arterial occlusive disease

The patient was a 77-year-old female who had been treated medically for angina pectoris since 5 years ago. Expanded aneurysms in the distal aortic arch and in the descending thoracic aorta were seen during follow-up. She presented continuous back-pain at rest along with increasing size of the aneurysms despite antihypertensive therapies after admission. First, two saphenous vein grafts were anastomosed to the left anterior descending artery and obtuse marginal artery under beating heart. Next, the proximal portion of the left subclavian artery was clamped and divided. To this graft, the proximal ends of the coronary bypassed vein grafts were anastomosed and coronary perfusion was established and maintained until this artery was anastomosed to the aortic graft. Then, the aneurysms in the distal arch and descending thoracic aorta were excised and the aorta and its two pairs of intercostal arteries were reconstructed. The Postoperative course was uneventful with favorable cardiac function.

Vesicular monoamine transporter 1 is responsible for storage of 5-hydroxytryptamine in rat pinealocytes

Vesicular monoamine transporters (VMATs) are involved in chemical transduction in monoaminergic neurons and various endocrine cells through the storage of monoamines in secretory vesicles. Mammalian pinealocytes contain more 5-hydroxytryptamine (5-HT) than any other cells and are expected to contain VMAT, although no information is available so far. Upon the addition of ATP, radiolabeled 5-HT was taken up by a particulate fraction prepared from cultured rat pinealocytes. The 5-HT uptake was inhibited significantly by bafilomycin A1 (an inhibitor of vacuolar H+-ATPase), 3,5-di-tert-butyl-4-hydroxybenzylidenemalononitrile (a proton conductor), or reserpine (an inhibitor of VMAT). RT-PCR analysis suggested that VMAT type 1 (VMAT1), but not type 2, is expressed. Antibodies against VMAT1 recognized a single polypeptide with an apparent molecular mass of approximately 55 kDa, and specifically immunostained pinealocytes. VMAT1 immunoreactivity was high in the vesicular structures in the varicosities of long branching processes and was associated with 5-HT, but not with synaptophysin, a marker protein for microvesicles. The 5-HT immunoreactivity in the long branching processes disappeared upon incubation with reserpine. These results indicate that 5-HT, at least in part, is stored in vesicles other than microvesicles in pinealocytes through a mechanism similar to that of various secretory vesicles.

Effects of bilobalide, a sesquiterpene in Ginkgo biloba leaves, on population spikes in rat hippocampal slices

The effects of bilobalide, a sesquiterpene isolated from the leaves of Ginkgo biloba L., were investigated in a rat hippocampal slice preparation. Bilobalide (10-500 microM) significantly increased the amplitude of population spikes evoked by electrical stimulation of Schaffer collateral/commissural fibers in a concentration-dependent manner. Paired-pulse inhibition at interpulse intervals of 10-50 ms was significantly reduced in the presence of bilobalide (50 microM). The inhibitory action of muscimol (1 microM) was attenuated by bilobalide (100 microM). These results suggest that bilobalide induces an enhancement of excitability of CA1 pyramidal neurons, which involves, at least in part, a reduction in GABAergic inhibition in rat hippocampus.

Pulmonary function after segmentectomy for small peripheral carcinoma of the lung

OBJECTIVE

The aim of this study is to compare the pulmonary function after a segmentectomy with that after a lobectomy for small peripheral carcinoma of the lung.

PATIENTS AND METHODS

Between 1993 and 1996, segmentectomy and lobectomy were performed on 48 and 133 good-risk patients, respectively. Lymph node metastases were detected after the operation in 6 and 24 patients of the segmentectomy and lobectomy groups, respectively. For bias reduction in comparison with a nonrandomized control group, we paired 40 segmentectomy patients with 40 lobectomy patients using nearest available matching method on the estimated propensity score.

RESULTS

Twelve months after the operation, the segmentectomy and lobectomy groups had forced vital capacities of 2.67 +/- 0.73 L (mean +/- standard deviation) and 2.57 +/- 0.59 L, which were calculated to be 94.9% +/- 10.6% and 91.0% +/- 13.2% of the preoperative values (P =.14), respectively. The segmentectomy and lobectomy groups had postoperative 1-second forced expiratory volumes of 1.99 +/- 0.63 L and 1.95 +/- 0.49 L, which were calculated to be 93.3% +/- 10.3% and 87.3% +/- 14.0% of the preoperative values, respectively (P =.03). The multiple linear regression analysis showed that the alternative of segmentectomy or lobectomy was not a determinant for postoperative forced vital capacity but did affect postoperative 1-second forced expiratory volume.

CONCLUSION

Pulmonary function after a segmentectomy for a good-risk patient is slightly better than that after a lobectomy. However, segmentectomy should be still the surgical procedure for only poor-risk patients because of the difficulty in excluding patients with metastatic lymph nodes from the candidates for the procedure.

The influence of lung cancer mass screening on surgical results

BACKGROUND

After the introduction of the mass screening program for lung cancer, the number of patients detected by mass screening increased as well as the number of early staged patients. Therefore, we examined the influence of lung cancer mass screening on surgical results.

METHODS

A total of 1177 primary lung cancer cases, who underwent surgery from 1963 to 1992, were retrospectively reviewed. They were grouped according to the changes in the mass screening system: the first period (1963-1977) before lung cancer screening started, the second period (1978-1986) when mass screening was conducted by the local government, and the third period (1987-1992) after the launching of the national screening program.

RESULTS

The rate of cases detected by mass screening increased over time and the 5-year survival rate improved significantly, from 33.7% in the first period, to 51.8% in the second period and finally, to 58.4% in the third period. The improvement is attributable to a relative increase of rate of stage I cases and better stage I survival rate. Specifically, in stage I cases, improvement resulted from a relative increase of stage IA in peripheral type and roentgenographically occult lung cancer cases and from better survival rate of these two groups.

CONCLUSION

As lung cancer screening has come into widespread use, detection of peripheral small-sized lung cancer and roentgenographically occult lung cancer have increased and consequently, surgical results have improved.

Effects of bilobalide on gamma-aminobutyric acid levels and glutamic acid decarboxylase in mouse brain

We have previously demonstrated that bilobalide, a constituent of the Ginkgo biloba extract, possesses anticonvulsant activity, and suggested that the mechanism of its anticonvulsant action involves modulation of y-aminobutyric acid (GABA)-related neuronal transmission. This study examined the effects of bilobalide on the level of GABA and glutamate, the activity and the amount of glutamic acid decarboxylase (EC 4.1.1.15), and the function of GABA(A) receptors in the hippocampus, cerebral cortex and striatum of the mouse. GABA levels, glutamic acid decarboxylase activity, and the protein amount of 67 kDa glutamic acid decarboxylase in the hippocampus of mice treated with bilobalide (30 mg/kg, p.o., once a day for 4 days) were significantly higher than those in controls. However, there were no significant differences in glutamate levels or, the number and the dissociation constants of GABA(A) receptors in the hippocampus between control and bilobalide-treated mice. These results suggest that the anticonvulsant effect of bilobalide is due to elevation of GABA levels, possibly through potentiation of glutamic acid decarboxylase activity and enhancement of the protein amount of 67 kDa glutamic acid decarboxylase by bilobalide.

Successful surgery for an acute type A aortic dissection following repair of a descending thoracic aortic aneurysm

Acute type A aortic dissection in the presence of a previously repaired atherosclerotic descending thoracic aortic aneurysm is rarely reported. We experienced a patient who underwent an ascending aortic replacement with reconstruction of the aortic arch 16 months after repair of a descending thoracic aortic aneurysm. We succeeded in the redo operation with comprehensive techniques involving selective cerebral perfusion, deep hypothermia, early antegrade systemic circulation for cerebral protection, and femoro-femoral bypass with occlusion of the descending aorta for lower systemic perfusion as well as renal perfusion. The patient recovered and is doing well one year after the redo operation.

Improvement of intestinal absorption of peptide drugs by glycosylation: transport of tetrapeptide by the sodium ion-dependent D-glucose transporter

A tetrapeptide (Gly-Gly-Tyr-Arg, GGYR), which is not transported by di- or tripeptide transporters, was glycosylated with p-(succinylamido)phenyl alpha- or beta-D-glucopyranoside (alpha,beta-SAPG) to investigate whether these glycosylated molecules are transported by the Na+-dependent D-glucose transporter. Their uptake into brush border membrane vesicles (BBMVs) and transport through the intestinal membrane were examined using the rapid filtration technique and the everted sac method. It was observed that glycosylation at the alpha-amino position of GGYR increased resistance to aminopeptidase activity and inhibited its degradation. When alpha- and beta-SAPG-GGYR were incubated with BBMVs, overshoot uptake was observed about 2 min after the start of incubation in the presence of an inward Na+ gradient. This uptake remained unaffected by the addition of GGYR while it was significantly inhibited when Na+ was replaced with K+ or alpha- and beta-SAPG-GGYR were incubated with BBMVs at 4 degrees C. Uptake was also markedly inhibited either with 1 mM phloridzin or 10 mM D-glucose. These findings suggested that the Na+-dependent glucose transporter (SGLT-1) played an important role in the uptake of both alpha- and beta-SAPG-GGYR into BBMVs. A comparison of alpha- with beta-SAPG-GGYR revealed that the amount of beta-SAPG-GGYR taken up was greater than that of alpha-SAPG-GGYR. From the everted sac method data, it was shown that the elimination clearance from the mucosal side, CLel, and permeation clearance to the serosal side, CLp, were 15.82+/-6.83 and 0.83+/-0.06 microL/min/cm for alpha-SAPG-GGYR and 44.52+/-3.61 and 3.50+/-0.81 microL/min/cm for beta-SAPG-GGYR, respectively, and that alpha-SAPG-GGYR was more resistant to enzymatic degradation than beta-SAPG-GGYR. Permeation of both alpha- and beta-SAPG-GGYR was inhibited in the presence of D-glucose and in the absence of a Na+ gradient, suggesting that both alpha- and beta-SAPG-GGYR were transported by the Na+-dependent D-glucose transporter. The permeation clearance transported by the Na+-dependent D-glucose transporter, (CLp)Na+, of beta-SAPG-GGYR was about 5 times greater than that for alpha-SAPG-GGYR. This result may be ascribable to the fact that the beta-form of glucose has higher affinity to SGLT-1 than the alpha-form. The results of the present study encourage further investigations on improvements in intestinal absorption of peptide drugs by glycosylation.

Complete intercostal artery reimplantation using a method of aneurysmoplasty

We report the case of a 58-year-old woman who underwent repair of a chronic dissecting thoracoabdominal aortic aneurysm. Using a method of aneurysmoplasty under normothermic cardiopulmonary bypass, all intercostal arteries were quickly reperfused, and the spinal cord ischemic time was minimized. No neurological deficits developed in our patient using this method.

Effect of cardiopulmonary bypass on cytokine release and adhesion molecule expression in alveolar macrophages. Preliminary report in six cases

Although recent studies have shown that adhesion molecules on alveolar macrophages are important in a variety of pulmonary diseases, there have been few studies on the phenotypic and functional changes of alveolar macrophages during cardiopulmonary bypass. To investigate the possible role of alveolar macrophages in activating pulmonary immunity during cardiopulmonary bypass, we measured the expression of adhesion molecules on alveolar macrophages and peripheral blood monocytes in patients undergoing cardiopulmonary bypass. Antigens were stained with monoclonal antibodies against adhesion molecules, and the expression of antigens was quantified by flow cytometry as the ratio of specific to nonspecific linear fluorescence. On alveolar macrophages obtained after the release of aortic cross-clamp, macrophages as compared with alveolar macrophages obtained before cardiopulmonary bypass, there was a significant enhancement of CD11a, CD11b, CD11c, and CD18. In addition, alveolar macrophages, but not peripheral monocytes, produced higher levels of TNF-alpha and IL-8 when they were cultured in vitro. A higher expression of CD11 and CD18 on alveolar macrophages and enhanced production of cytokines after release of the aortic cross-clamp may contribute to immune activation in lung by macrophage-lymphocyte interaction.

Rheumatoid arthritis and the risk of malignancy

OBJECTIVE

To determine the relative risks of malignancy and of site-specific malignancies in patients with rheumatoid arthritis (RA).

METHODS

In a prospective cohort study, 862 patients with RA (96% white) were enrolled from 1966 to 1974 and were followed up for up to 35 years (mean 17.4 years) at the University of Saskatchewan Rheumatic Disease Unit. All diagnoses of cancer were cross-referenced with the Provincial Cancer Registry. Expected cancer incidence rates were determined based on province of Saskatchewan population statistics matched to each study patient for age, sex, and calendar year. Standardized incidence ratios (SIRs) of the observed-to-expected cancer incidence and 95% confidence intervals (95% CI) were then calculated.

RESULTS

A total of 136 cases of cancer were observed compared with 168 expected (SIR 0.80, P = 0.011 [95% CI 0.67-0.95]). The relative risk of colorectal malignancy was significantly reduced in the RA study population (SIR 0.52, P = 0.037 [95% CI 0.25-0.96]). A significant excess of leukemia was found (SIR 2.47, P = 0.026 [95% CI 1.12-4.69]), whereas the incidence rates for Hodgkin's disease and non-Hodgkin's lymphoma and all other site-specific malignancies were not found to be significantly different from general population rates.

CONCLUSION

In our cohort of RA patients, colorectal cancer was detected in only half the expected number of patients. This risk reduction may be related to long-term nonsteroidal antiinflammatory drug (NSAID) use in RA, as has been suggested in several other studies of long-term NSAID use. An increased risk of leukemia was confirmed. This may be due to the persistent immune stimulation associated with RA itself, since other potential explanatory factors for increased leukemia were not apparent. Despite the excess of hemopoietic malignancy and despite treatment of RA with potentially oncogenic agents, the overall risk of malignancy was reduced in this RA cohort.

[Development of a blood cardioplegia delivery system for children]

We have developed a blood cardioplegia delivery system for children. Essential points of a delivery system in pediatric cardiac surgery are (1) a small amount of priming volume of a delivery system, and (2) slow, steady infusion of a cardioplegic solution. We changed a heat exchanger to a smaller one for reduction of priming volume, and changed a roller pump tube to a smaller one for slow, steady infusion. Thus, priming volume of a delivery system has reduced from 180 to 100 ml, and we can infuse a cardioplegic solution at a steady rate less than 10 ml/min. Our clinical experience with this system suggests that this blood cardioplegia delivery system is useful for pediatric cardiac surgery.

Intermediate TCR cells in mouse lung: their effector function to induce pneumonitis in mice with autoimmune-like graft-versus-host disease

The lung comprises lymphocytes even under noninflammatory conditions. We investigated the presence of NK cells, extrathymic T cells, and thymus-derived T cells in this organ. As shown previously in mouse liver, two-color staining for CD3 and IL-2R beta-chain (IL-2Rbeta) identifies CD3- IL-2Rbeta+ NK cells, CD3int IL-2Rbeta+ cells (int indicates intermediate; of extrathymic origin), and CD3high IL-2Rbeta- cells (high indicates high; of thymic origin). These populations were present in the lungs of normal mice in a unique manner (i.e., NK cells > CD3high cells > CD3int cells). The proportion of CD3int cells increased in the lung with age. In athymic mice, only CD3int cells were detected in the lung. In contrast to CD3int cells in the liver, the majority of these cells in the lung did not express NK1.1 Ags. Other properties of CD3int cells in the lung were the same as those in the liver, e.g., double-negative CD4- 8- cells and gammadelta T cells. CD3int cells in the lung contained forbidden clones similar to those in other organs. When (B6 x bm12) F1 mice (Ly5.2) were injected with CD3high cells of B6-Ly5.1 origin, F1 mice fell victim to chronic graft-vs-host disease and pneumonitis, showing the expansion of CD3int cells. Almost all of them were of recipient origin (Ly5.2+). More importantly, such CD3int cells induced autoimmune-like pneumonitis when injected into irradiated F1 mice. CD3int cells isolated from the lung in mice with graft-vs-host disease exerted autologous cytotoxicity against thymocytes in vitro. These results suggest that extrathymic T cells exist in the lung and that their expansion may be responsible for inflammatory lung diseases.

Intermediate TCR cells in mouse lung: their effector function to induce pneumonitis in mice with autoimmune-like graft-versus-host disease

The lung comprises lymphocytes even under noninflammatory conditions. We investigated the presence of NK cells, extrathymic T cells, and thymus-derived T cells in this organ. As shown previously in mouse liver, two-color staining for CD3 and IL-2R beta-chain (IL-2Rbeta) identifies CD3- IL-2Rbeta+ NK cells, CD3int IL-2Rbeta+ cells (int indicates intermediate; of extrathymic origin), and CD3high IL-2Rbeta- cells (high indicates high; of thymic origin). These populations were present in the lungs of normal mice in a unique manner (i.e., NK cells &gt; CD3high cells &gt; CD3int cells). The proportion of CD3int cells increased in the lung with age. In athymic mice, only CD3int cells were detected in the lung. In contrast to CD3int cells in the liver, the majority of these cells in the lung did not express NK1.1 Ags. Other properties of CD3int cells in the lung were the same as those in the liver, e.g., double-negative CD4- 8- cells and gammadelta T cells. CD3int cells in the lung contained forbidden clones similar to those in other organs. When (B6 x bm12) F1 mice (Ly5.2) were injected with CD3high cells of B6-Ly5.1 origin, F1 mice fell victim to chronic graft-vs-host disease and pneumonitis, showing the expansion of CD3int cells. Almost all of them were of recipient origin (Ly5.2+). More importantly, such CD3int cells induced autoimmune-like pneumonitis when injected into irradiated F1 mice. CD3int cells isolated from the lung in mice with graft-vs-host disease exerted autologous cytotoxicity against thymocytes in vitro. These results suggest that extrathymic T cells exist in the lung and that their expansion may be responsible for inflammatory lung diseases.

Direct and indirect medical costs incurred by Canadian patients with rheumatoid arthritis: a 12 year study

OBJECTIVE

To perform the first prospective longitudinal study of direct (health services utilized) and indirect costs (diminished productivity represented by income loss) incurred by patients with rheumatoid arthritis (RA) in Saskatoon and Montreal, followed for up to 12 and 4 years, respectively.

METHODS

1063 patients reported on health status, health services utilization, and diminished productivity every 6 months.

RESULTS

Annual direct costs were $3788 (1994 Canadian dollars) in the late 1980s and $4656 in the early 1990s. Given that the average age exceeded 60 years, few participated in labor force activities or considered themselves disabled from the labor force and their indirect costs were substantially less, $2165 in the late 1980s and $1597 in the early 1990s. Institutional stays and medications made up at least 80% of total direct costs. Lengths of stay in acute care facilities remained constant, but the rate of hospitalization increased in the early 1990s, increasing average hospital costs per patient from $1563 in the late 1980s to $2023 in the early 1990s. For nonacute care facilities, rate of admission as well as length of stay increased over time, increasing costs per patient in Saskatoon 5-fold, from $291 to $1605. Those with greater functional disability incurred substantially higher direct and those under 65 years incurred higher indirect costs.

CONCLUSION

Direct costs are higher than indirect costs. The major component is due to institutional stays that, in contrast to other direct cost components, is increased in the older and more disabled. Measures to reduce longterm disability by earlier, more aggressive intervention have the potential to produce considerable cost savings. However, it is unknown which strategies will have the greatest effect on outcome and accordingly, how resources can be optimally allocated.

Bilobalide, a constituent of Ginkgo biloba L., potentiates drug-metabolizing enzyme activities in mice: possible mechanism for anticonvulsant activity against 4-O-methylpyridoxine-induced convulsions

Anticonvulsant effects of bilobalide, one of the constituents of Ginkgo biloba L., on the convulsions induced by 4-O-methylpyridoxine (MPN) were investigated in mice. Bilobalide reduced the duration and incidence of MPN-induced convulsions depending on its dose and the period of treatment. In addition, the anticonvulsant effect was manifested more than 24 hours after treatment and the effect lasted for 7 days after its withdrawal. In mice treated with bilobalide (30 mg/kg, p.o., once a day for 4 days), hepatic 7-methoxycoumarin O-demethylase activity was potentiated, and the disappearance of MPN in blood after MPN injection was faster than in controls. From these results, it is assumed that the anticonvulsant effect of bilobalide against convulsions induced by MPN partly involves modulation of hepatic drug-metabolizing enzyme activity, which leads to accelerated elimination of MPN.