Treatment of a full-thickness articular cartilage defect in the femoral condyle of an athlete with autologous bone-marrow stromal cells

OBJECTIVES

Human bone-marrow stromal cells are believed to be multipotent even in adults. This study assessed the effectiveness of autologous bone-marrow stromal cells, which were embedded within a collagen scaffold, to repair a full-thickness articular cartilage defect in the medial femoral condyle of an athlete.

PATIENT AND METHODS

A 31-year-old male judo player suffering from pain in the right knee was reviewed. A 20 x 30-mm full-thickness cartilage defect (International Cartilage Repair Society classification (ICRS) grade IV) was revealed in the weight-bearing area of the medial femoral condyle. With the informed consent of the patient, the defect was treated with autologous bone-marrow stromal cells. Bone marrow was aspirated from the iliac crest of the patient 4 weeks before surgery. After removing the erythrocytes, the remaining cells were expanded in culture. Adherent cells were collected and embedded within a collagen gel, which was transferred to the articular cartilage defect in the medial femoral condyle. The implant was covered with an autologous periosteal flap.

RESULTS

Seven months after surgery, arthroscopy revealed the defect to be covered with smooth tissues. Histologically, the defect was filled with a hyaline-like type of cartilage tissue which stained positively with Safranin-O. One year after surgery, the clinical symptoms had improved significantly. The patient had reattained his previous activity level and experienced neither pain nor other complications.

CONCLUSIONS

Our findings indicate that the transplantation of autologous bone-marrow stromal cells can promote the repair of large focal articular cartilage defects in young, active patients.

Repair of osteochondral defects with a new porous synthetic polymer scaffold

We developed a new porous scaffold made from a synthetic polymer, poly(DL-lactide-co-glycolide) (PLG), and evaluated its use in the repair of cartilage. Osteochondral defects made on the femoral trochlear of rabbits were treated by transplantation of the PLG scaffold, examined histologically and compared with an untreated control group.

Fibrous tissue was initially organised in an arcade array with poor cellularity at the articular surface of the scaffold. The tissue regenerated to cartilage at the articular surface. In the subchondral area, new bone formed and the scaffold was absorbed. The histological scores were significantly higher in the defects treated by the scaffold than in the control group (p < 0.05).

Our findings suggest that in an animal model the new porous PLG scaffold is effective for repairing full-thickness osteochondral defects without cultured cells and growth factors.

Effects of Inertia and Gravity on Liquid Plug Splitting at a Bifurcation

Liquid plugs may form in pulmonary airways during the process of liquid instillation or removal in many clinical treatments. During inspiration the plug may split at airway bifurcations and lead to a nonuniform final liquid distribution, which can adversely affect treatment outcomes. In this paper, a combination of bench top experimental and theoretical studies is presented to study the effects of inertia and gravity on plug splitting in an airway bifurcation model to simulate the liquid distributions in large airways. The splitting ratio, Rs, is defined as the ratio of the plug volume entering the upper (gravitationally opposed) daughter tube to the lower (gravitationally favored) one. Rs is measured as a function of parent tube Reynolds number, Rep; gravitational orientations for roll angle, ϕ, and pitch angle, γ; parent plug length LP; and the presence of pre-existing plug blockages in downstream daughter tubes. Results show that increasing Rep causes more homogeneous splitting. A critical Reynolds number Rec is found to exist so that when Rep⩽Rec, Rs=0, i.e., no liquid enters the upper daughter tube. Rec increases while Rs decreases with increasing the gravitational effect, i.e., increasing ϕ and γ. When a blockage exists in the lower daughter, Rec is only found at ϕ=60deg in the range of Rep studied, and the resulting total mass ratio can be as high as 6, which also asymptotes to a finite value for different ϕ as Rep increases. Inertia is further demonstrated to cause more homogeneous plug splitting from a comparison study of Rs versus Cap (another characteristic speed) for three liquids: water, glycerin, and LB-400X. A theoretical model based on entrance flow for the plug in the daughters is developed and predicts Rs versus Rep. The frictional pressure drop, as a part of the total pressure drop, is estimated by two fitting parameters and shows a linear relationship with Rep. The theory provides a good prediction on liquid plug splitting and well simulates the liquid distributions in the large airways of human lungs.

Donor Leukocytes Combined With Delayed Immunosupressive Drug Therapy Prolong Limb Allograft Survival

Donor leukocytes administered at the time of transplantation may prolong organ allograft survival. Delayed administration of calcineurin inhibitors, such as FK506 or cyclosporine, may enhance their efficacy. Herein the effectiveness of this strategy to promote limb transplant survival was investigated in the strong histocompatibility barrier of Brown-Norway donor to Lewis recipients. Donor leukocytes (6 x 10(7) intravenously) were injected on the day of transplantation followed on day 1 to 14 with mycophenolate mofetil (MMF; 15 mg/kg/d) and prednisone, (0.5 mg/kg/d) which were then tapered by 20% each week and stopped at week 7. Administration of of FK506 (2 mg/kg/d) was started on day 4 and continued for 8 weeks, then tapered for 4 weeks to a maintenance dose of 0.8 mg/kg/d, which was continued for 12 weeks (group A; n = 8). A control group (n = 8) underwent identical treatment save for donor leukocyte injection but rather commencement of FK506 on day 1. Rejection was common during FK506 tapering in both groups. However group A showed a significantly later onset, a shorter period for reversal of the first rejection, and a significantly lower dosage of FK506 at the time of rejection. After the completion of immunosuppression, rejection occurred significantly later in group A than the control group with one animal surviving without immunosuppression on day 344. This is the first trial of a donor leukocyte injection combined with delayed FK506 administration in limb transplantation, which suggested that it could produce a modest but significant improvement in outcome.

Molecular analysis of non-syndromic preaxial polydactyly: preaxial polydactyly type-IV and preaxial polydactyly type-I

Human GLI3 gene mutations have been identified in several phenotypes of digital abnormality such as Greig cephalopolysyndactyly syndrome, Pallister-Hall syndrome, preaxial polydactyly type-IV (PPD-IV) and postaxial polydactyly. However, the different phenotypes resulting from GLI3 mutations have not yet been properly defined. We have experienced two types of digital abnormality without other complicating developmental defects; a family with foot PPD-IV with syndactyly of the third and fourth fingers, and four sporadic cases with biphalangeal thumb polydactyly (PPD-I). The genes responsible for syndactyly of the third and fourth fingers (syndactyly type-I) and PPD-I have not yet been identified; we therefore examined the involvement of the GLI3 gene in these subtypes of digital abnormality. We found a non-sense mutation in the GLI3 gene in the family with foot PPD-IV accompanied with hand syndactyly of the third and fourth fingers, but no mutations were detected in the GLI3 gene in the four other cases with PPD-I alone. Thus, the phenotype of foot PPD-IV accompanied with hand syndactyly of the third and fourth fingers may result from a GLI3 mutation, whereas the PPD-I phenotype alone is not caused by GLI3 gene defect. These results will help to define the phenotypic spectrum of GLI3 morphopathies, which have been recently proposed.

Mutational analysis of the TCOF1 gene in 11 Japanese patients with Treacher Collins Syndrome and mechanism of mutagenesis

Treacher Collins Syndrome (TCS) (OMIM 154500) is a congenital, craniofacial disorder inherited as an autosomal dominant trait. The responsible gene for TCS, TCOF1, was mapped to 5q32-33.1 and identified in 1996. Since then, TCOF1 mutations in patients with TCS have been reported from Europe, North and South America, however, no TCS cases from an Asian country have been molecularly characterized. Here we report mutational analysis for 11 Japanese patients with TCS for the first time, and have identified TCOF1 mutations in 9 of them. The mutations detected were various, but most likely all the mutations are predicted to result in a truncated gene product, known as treacle. One mutation frequently reported was included in our cases, but no missense mutations were detected. These findings are similar to those for the previous studies for TCS in other races. We have speculated about the molecular mechanisms of the mutations in most cases. Collectively, we have defined some of the characteristic molecular features commonly observed in TCS patients, irrespective of racial difference.

Donor leukocytes combine with immunosuppressive drug therapy to prolong limb allograft survival

Donor leukocytes administered at the time of transplantation may prolong organ allograft survival. This study examined the effectiveness of donor leukocyte injection combined with immunosuppression for limb transplantation across the strong histocompatibility barrier of a Brown Norway donor to a Lewis recipient. Eight animals received 6 x 10(7) donor leukocytes injected on the day of transplantation. From day 1, FK506 (2 mg/kg/d), mycophenolate mofetil (MMF) (15 mg/kg/d), and prednisone (0.5 mg/kg/d) were administered for 2 weeks. After week 2, prednisone and MMF were both tapered by 20% of the initial dosage per week. After week 7, the animals received only FK506 (2 mg/kg/d). From week 8, FK506 was tapered to the maintenance dose of 0.8 mg/kg/d at week 10 and was stopped on week 24. A control group of 8 animals underwent identical treatment except that the leukocyte injection was omitted. Rejection was observed in both groups during FK506 monotherapy; however, the onset of early rejection episodes was significantly later, the period for reversal of the first rejection was significantly shorter, and the dosage of FK506 at the time of rejection was significantly lower among leukocyte-treated recipients. After completion of immunosuppression, survival was modestly prolonged in the leukocyte-treated group. One animal is surviving without immunosuppression on day 234. This trial of donor leukocyte injection combined with immunosuppression in limb transplantation showed a modest, but significant, improvement in outcome.

Evidence for a kaon-bound state K(-)pp produced in K(-) absorption reactions at rest

We have searched for a deeply bound kaonic state by using the FINUDA spectrometer installed at the e(+)e(-) collider DAPhiNE. Almost monochromatic K(-)'s produced through the decay of phi(1020) mesons are used to observe K(-) absorption reactions stopped on very thin nuclear targets. Taking this unique advantage, we have succeeded to detect a kaon-bound state K(-)pp through its two-body decay into a Lambda hyperon and a proton. The binding energy and the decay width are determined from the invariant-mass distribution as 115(+6)(-5)(stat)(+3)(-4)(syst) MeV and 67(+14)(-11)(stat)(+2)(-3)(syst) MeV, respectively.

Driving midgut-specific expression and secretion of a foreign protein in transgenic mosquitoes with AgAper1 regulatory elements

The Anopheles gambiae adult peritrophic matrix protein 1 (AgAper1) regulatory elements were used to drive the expression of phospholipase A2 (PLA2), a protein known to disrupt malaria parasite development in mosquitoes. These AgAper1 regulatory elements were sufficient to promote the accumulation of PLA2 in midgut epithelial cells before a blood meal and its release into the lumen upon blood ingestion. Plasmodium berghei oocyst formation was reduced by approximately 80% (74-91% range) in transgenic mosquitoes. Blood-seeking behaviour and survival of AgAper1-PLA2 transgenic mosquitoes were comparable to sibling wild-type mosquitoes, while fertility was substantially lower. Ultrastructural studies suggest that decreased fitness is a consequence of internal damage to midgut epithelial cells.

Inhibitory effects of safe and novel SOD derivatives, galactosylated-SOD, on hepatic warm ischemia/reperfusion injury in pigs

BACKGROUND/AIMS

Oxygen-derived free radicals such as superoxide play an important role in ischemia/reperfusion (IR) injury during and after extensive liver surgery or liver transplantation. Superoxide dismutase (SOD) has protective effects against hepatic IR injury. The effect of native SOD is, however, limited because of rapid elimination from the blood circulation and poor affinity for liver cells. It was reported by our collaborators that a SOD derivative modified with galactose (Gal-SOD) was selectively delivered well to hepatocytes by direct attachment to galactose receptors. In the present study, the efficacy of this agent for attenuating hepatic warm IR injury was investigated using the pig model.

METHODOLOGY

After 45-min clamping of the hepatic artery and portal vein, pigs were divided into 3 groups according to the following treatments. Ten milliliters of normal saline in Group 1 (n=5), 10,000 units/kg of native SOD in Group 2 (n=5) and 10,000 units/kg of Gal-SOD in Group 3 (n=5) were given just prior to hepatic reperfusion. Liver function including clearance of total bile acid (TBA) and hyaluronic acid (HA) was investigated. Lipid peroxidase of the liver tissue (LPO) and histological findings were examined. In addition, survival rates of the pigs in each group were evaluated.

RESULTS

The survival rates at the 7th day after the operation were 60%, 80%, 100% in Groups 1, 2 and 3, respectively. Liver function tests, clearance of TBA and HA, and LPO levels were significantly improved in Groups 3 over findings in Groups 1 and 2. Congestion of hepatic tissues and vacuolization of hepatocytes in Group 3 were less than those in Groups 1 and 2. These results suggested that oxygen-derived free radicals were scavenged by Gal-SOD and IR injury was attenuated.

CONCLUSIONS

A safe and novel agent, Gal-SOD has a protective effect against hepatic warm IR injury.

Expression of inhibin α, glial cell line-derived neurotrophic factor and stem cell factor in Sertoli cell-only syndrome: relation to successful sperm retrieval by microdissection testicular sperm extraction

BACKGROUND

Microdissection testicular sperm extraction (TESE) has provided new hope for successful sperm retrieval to patients with Sertoli cell-only syndrome (SCO). We determined expression of the inhibin alpha subunit, glial cell line-derived neurotrophic factor (GDNF) and stem cell factor (SCF) in Sertoli cells obtained from patients with SCO immunohistochemically and compared expression rates with rates of microdissection TESE sperm retrieval.

METHODS

Testicular biopsy specimens were obtained from 52 men with non-obstructive azoospermia who underwent microdissection TESE and were diagnosed with SCO by histological analysis.

RESULTS

All specimens showed intense staining for the inhibin alpha subunit. Moderate or intense staining for GDNF was observed in 65.8% of specimens. All but one showed moderate or intense staining for SCF. Among specimens negative for GDNF, the sperm retrieval rate was significantly higher (100%) for specimens with intense staining for SCF than for specimens with no or moderate staining (30.7%) (P<0.05) for SCF.

CONCLUSION

GDNF expression differs among patients with SCO. The sperm retrieval rate was high in cases of no staining for GDNF and intense staining for SCF.

Storage and secretion of Ag-Aper14, a novel peritrophic matrix protein, and Ag-Muc1 from the mosquito Anopheles gambiae

The gene Ag-Aper14 encodes a novel peritrophic matrix (or peritrophic membrane; PM) protein in the mosquito Anopheles gambiae. The Ag-Aper14 protein is merely 89 amino acids long and has a single putative chitin-binding domain. Prior to blood feeding, the Ag-Aper14 protein is stored in secretory vesicles next to the epithelial cell lumenal surface. Immunoelectron microscopy has revealed that Ag-Aper14 co-localizes to the same secretory vesicles as another PM protein, Ag-Aper1, indicating a common mode of regulated secretion. Conversely, Ag-Muc1, an epithelial cell-surface protein, does not co-localize to these secretory vesicles and is detected only on the cell surface. After blood feeding, Ag-Aper14 is secreted and incorporated into the PM that surrounds the ingested blood.

Production of the neutron-rich hypernucleus 10LambdaLi in the (pi-,K+) double charge-exchange reaction

In order to produce a neutron-rich Lambda hypernucleus for the first time, we carried out an experiment by utilizing the (pi-,K+) double charge-exchange reaction on a 10B target. We observed the production of a 10LambdaLi hypernucleus. The cross section for the Lambda bound region was found to be 11.3+/-1.9 nb/sr with the 1.2 GeV/c incident momentum, which is compared with the 10LambdaB hypernucleus production cross section, 7.8+/-0.3 microb/sr, in the (pi+,K+) reaction with a 1.05 GeV/c incident momentum beam.

Differential regulation of inhibin subunits by germ cells in human testes

Inhibin B is comprised of two dissimilar disulfide-linked subunits, termed alpha and betaB, and is physiologically more important than inhibin A in the male. The aim of this study was to investigate testicular expression of inhibin subtypes in infertile men to uncover any interaction between Sertoli cells and germ cells. Ten azoospermic patients with Sertoli cell only syndrome (SCO) and 39 oligozoospermic men were included in this study. Follicle-stimulating hormone (FSH), luteinizing hormone (LH), and testosterone concentrations were determined by chemiluminescence assays. The serum concentrations of inhibin B were measured by enzyme-linked immunosorbent assay. Immunohistochemical staining for the alpha-subunit, betaA-subunit, and betaB-subunit of inhibin were performed on testicular biopsy specimens. The results were that serum inhibin B was undetectable in azoospermic men with SCO, while it was 133.8 +/- 82.0 pg/ml in oligozoospermic men. There was little expression of betaA in the testes of any patient. Expression of inhibin alpha and betaB was observed in Sertoli cells. The percentage of Sertoli cells expressing inhibin alpha was similar in azoospermic patients with SCO (55.3% +/- 20.6%) and in oligozoospermic patients (42.8% +/- 30.4%). In contrast, expression of betaB in Sertoli cells of azoospermic patients (24.9% +/- 16.8%) was lower than in oligozoospermic men (43.4% +/- 25.5%: P = 0.0308). There are no significant correlations between testicular expression of inhibin betaB and the serum inhibin B concentrations. The expression of inhibin betaB by Sertoli cells is dependent on the coexistence of spermatogenic activity within these seminiferous tubules, explaining why the level of inhibin B is low in patients with SCO.

Treacher Collins syndrome with craniosynostosis, choanal atresia, and esophageal regurgitation caused by a novel nonsense mutation in TCOF1

Treacher Collins syndrome (TCS) is caused by mutations in TCOF1 of the nonsense, small deletion, and small insertion types, which most likely result in haploinsufficiency. We report a novel de novo nonsense mutation 2731C --> T, resulting in Arg911Stop, which truncates the protein. Our patient had the classic findings of TCS, but with documented craniosynostosis, choanal atresia, and esophageal regurgitation.

Storage and secretion of the peritrophic matrix protein Ag-Aper1 and trypsin in the midgut of Anopheles gambiae

The gene Ag-Aper1 encodes a peritrophic matrix (PM) protein from the mosquito Anopheles gambiae. Ag-Aper1 gene expression and protein localization in the mosquito midgut were studied during the course of a blood meal. Ag-Aper1 mRNA abundance does not change appreciably during the course of blood ingestion and digestion. Prior to a blood meal, the protein is stored in secretory vesicles of midgut epithelial cells. Moreover, Ag-Aper1 colocalizes to the same secretory vesicles as trypsin, indicating that these proteins use a common secretory pathway. Blood feeding triggers the secretion of vesicle contents into the midgut lumen, after which Ag-Aper1 is incorporated into the PM. Newly synthesized Ag-Aper1 protein was again detected within the midgut epithelial cells at 60 h after blood ingestion.

Serial follow-up study of serum testosterone and antisperm antibodies in patients with non-obstructive azoospermia after conventional or microdissection testicular sperm extraction

Testicular sperm extraction (TESE) combined with intracytoplasmic sperm injection is becoming a first-line treatment even for non-obstructive azoospermia. The current focus of TESE is the identification of seminiferous tubules that contain spermatozoa and minimization of testicular damage. Although microdissection TESE has been introduced as a preferred procedure for sperm retrieval, no serial follow-up studies of testicular damage have been reported. In the present study, we assayed serum testosterone concentrations and for the presence of antisperm antibodies (ASA) for 1 year after conventional multiple TESE or microdissection TESE and compared postoperative testicular damage between procedures. Thirteen patients who underwent conventional multiple TESE and 12 patients who underwent microdissection TESE were included in this study. Serum total and free testosterone concentrations were evaluated before operation and 1, 6 and 12 months after TESE. Serum ASA was also evaluated before and 12 months after TESE. Serum total and free testosterone concentrations in all patients in both groups showed no significant postoperative decrease. A comparison between the two groups of serum total and free testosterone concentrations showed no significant difference (total testosterone, p = 0.2477; free testosterone, p = 0.3098). No incidence of new ASA formation was identified in the present study. In conclusion, TESE procedures cause neither a decrease of serum testosterone nor formation of ASA. Serum testosterone concentration are similar between patients in the conventional multiple TESE and microdissection groups. Therefore, microdissection TESE is safe with respect to testicular damage, particularly for patients with hypogonadism.

Production of adrenomedullin from synovial cells in rheumatoid arthritis patients

It was recently reported that plasma levels of adrenomedullin (AM), identified as a vasorelaxant peptide, are significantly higher in rheumatoid arthritis (RA) patients than in osteoarthritis (OA) patients. The objective of the present study was to elucidate AM production in synovial cells from patients with RA. Adrenomedullin mRNA was detected in cultured synovial cells from RA patients by reverse transcription polymerase chain reaction (RT-PCR). Immunohistochemical analysis demonstrated the presence of AM in synovial cells from RA patients. In addition, we investigated AM levels in knee joint fluids from RA and OA patients. Those from RA patients were elevated approximately threefold over those of OA patients. In this study, we demonstrated for the first time AM expression in synovial cells from RA patients and high levels of AM production in RA joint fluid.

Highly degenerate canted spin structure in bilayer manganite La1.1Sr1.9Mn2O7

We have observed magnetic diffuse signals of the bilayer manganite La1.1Sr1.9Mn2O7 by neutron scattering. Even at the low temperature, 20 K, there is a diffuse signal, which is much stronger than that observed in the high temperatures, 144 and 288 K. This signal cannot be characterized by a bilayer structure as observed at 144 K nor by a monolayer structure as at 288 K, but by a high degeneracy of a canted spin structure. Thus, an observation of this diffuse signal is the direct evidence for the establishment of the canted spin structure in La1.1Sr1.9Mn2O7.

Long-term evaluation of nutritional status using dual-energy X-ray absorptiometry in chronic hemodialysis patients

BACKGROUND

Hemodialysis patients very often suffer from malnutrition with net loss of body muscle and fat stores. Since protein-calorie malnutrition has been considered to be highly associated with increased morbidity and mortality, it is important that the nutritional status is evaluated accurately and that long-term evaluation of the nutritional status is performed to obtain good outcome.

PATIENTS AND METHODS

Forty-six patients (28 men and 18 women) undergoing maintenance hemodialysis were studied. Nutritional status of the patients was examined by dual-energy X-ray absorptiometry (DXA) and anthropometry measurements after a hemodialysis session and 4 years after the initial measurement.

RESULTS

Percent fat, the ratio of body fat (BF) to weight, determined by DXA correlated positively with body mass index (BMI) calculated from weight and height. There was also a significant positive correlation between lean body mass (LBM) determined by DXA and arm muscle circumference (AMC) calculated using the anthropometric method. In the study period of 4 years, LBM and bone mineral content (BMC) observed at the end point were significantly lower than those at the start. In contrast, BF and %fat at the end point were significantly higher as compared with those at the initial measurement.

CONCLUSION

These results indicate that DXA is a reliable method for body composition analysis in chronic hemodialysis patients. Because the detection of early alterations in body composition may provide an early indication of the development of malnutrition, serial evaluation of body composition using DXA should be valid for assessment of the nutritional status.

Epidemiological characteristics of acute pulmonary thromboembolism in Japan

AIM

In Japan, acute pulmonary thromboembolism (APTE) is still rare, but the number of patients with APTE has been steadily increasing. It is important for early diagnosis and early management of APTE to recognize epidemiological characteristics of this condition.

METHODS

We investigated the epidemiological characteristics of 252 patients with APTE who were admitted to our institutions between 1975 and 2001. APTE was more prevalent in women that in men. It was observed the most in the age group between 50s to 70s, especially in women. Many patients had prolonged immobilization, recent major operation, obesity, or cancer, as risk factors for venous thromboembolism. One hundred and thirty-eight patients developed APTE in hospital; 60 patients were in Department of Internal Medicine, 28 in General Surgery, 15 in Orthopedics, 15 in Obstetrics and Gynecology, and 20 in other services.

RESULTS

Among 58 patients with malignancy, 43% had cancers in digestive organs, 21% in gynecological, and 17% in urological. Among 61 patients who were examined for the presence of thrombophilia, 13 patients had inherited thrombophilia (8 protein C deficiency, 4 protein S deficiency, and 1 antithrombin III deficiency) 11 had antiphospholipid antibodies which indicated thrombophilia. Five out of the above 61 patients (8%) had no obvious risk factors including thrombophilia.

CONCLUSION

The findings in our patients were almost the same as those in Western patients, except for some points. These results might be useful to establish a preventive approach for APTE in Japan.

Interindividual variation in the ratio between plasma morphine and its metabolites in cancer patients

In 25 cancer patients treated with slow-release oral morphine and in 10 cancer patients treated with continuous infusion of morphine, plasma steady-state concentrations of morphine (M), morphine-3-glucuronide (M-3-G) and morphine-6-glucuronide (M-6-G) were determined by high-performance liquid chromatography. Blood samples were withdrawn at 0, 2 and 6 h after oral administration in patients treated with slow-release oral morphine and once or twice a day in patients treated with continuous infusion of morphine. In four cancer patients treated with continuous infusion of morphine, in order to analyze chronopharmacokinetic variability, the M-3-G/M ratio was observed at 12:00 h and 24:00 h. No significant changes were observed in M-3-G/M ratios and M-6-G ratios at 0, 2, and 6 h after oral administration of morphine. The M-3-G/M ratio (38.6 +/- 25.7) in the oral morphine group was significantly higher than that (15.3 +/- 12.9) in the continuous infusion group (p < 0.01). There was an approximately 10-fold interindividual variation in the M-3-G/M ratio both in the continuous infusion group and in the oral morphine group. These results suggest that the activity of UDP glucuronosyltransferase 2B7 in the intestinal metabolism of morphine may play an active part in a large interindividual variation in the ratio of metabolites to morphine. Further studies are needed to clarify this hypothesis.