Endoscopic resection of cystic lesions in the lumbar spinal canal: a report of two cases

We report excellent outcomes in two patients with cystic lesions in the lumbar spinal canal who underwent resection using the METRx micro-endoscopic discectomy (MED) system. Pathological examinations revealed the diagnoses of a synovial cyst and a discal cyst, respectively. Both of them were allowed to walk the next day after surgery with complete pain relief. Micro-endoscopic surgery provides excellent visualization of the spinal canal and allows minimally invasive removal of the pathological lesions. This technique can be an effective alternative to conventional open surgery for cystic lesions in the lumbar spine.

Immunosuppressive activity of FTY720, sphingosine 1-phosphate receptor agonist: I. Prevention of allograft rejection in rats and dogs by FTY720 and FTY720-phosphate

FTY720, a new class of immunomodulator, induces lymphopenia by sequestration of circulating lymphocytes into secondary lymphoid tissues. FTY720 at 0.1 to 1 mg/kg significantly prolonged the allograft survival in a dose-dependent manner and showed a marked synergistic effect in combination with cyclosporine (CsA) in rat skin and cardiac allograft models. In addition, the canine renal allograft survival was significantly prolonged by combination therapy with FTY720 at 0.03 to 1 mg/kg and CsA at 10 mg/kg as compared with monotherapy of FTY720 or CsA. By contrast, the combination therapy with CsA and azathioprine or CsA and mycophenolate mofetil resulted in only an additive effect in rat skin allograft. When FTY720 was administered to rats, FTY720 was metabolized by omega-oxidation of the octyl side chain, and beta-oxidation subsequently, or phosphorylated by sphingosine kinase. Omega- and beta-oxidized 4 metabolities of FTY720 at 10 mg/kg i.v. showed neither lymphopenia nor immunosuppressive activity in rat skin allograft. On the other hand, (S)-enantiomer of FTY720-phosphate at 0.1 and 1 mg/kg intravenously induced a marked lymphopenia and significantly prolonged the allograft survival in the rat allotransplantation. From these results, it is suggested the lymphopenia and the immunosuppression induced by FTY720 administration is due to the agonistic activity against SIP receptors of the active metabolite, (S)-FTY720-phosphate.

Neonatal alloimmune thrombocytopenia due to an antibody against a labile component of human platelet antigen-3b (Bak b)

We report the second case of neonatal alloimmune thrombocytopenia due to anti-human platelet antigen (HPA)-3b (Bak(b)) antibody. The infant was severely affected with intracranial haemorrhage. Most importantly, we were able to detect this antibody only by using fresh, unfixed platelets as antigen. This antibody was detectable neither by conventional mixed passive haemagglutination, platelet immunofluorescence test using fixed platelets, nor by monoclonal antigen immobilization of platelet antigen assay using solubilized platelets. We assume that this antibody reacts only with fresh platelets and that the antigen is a labile component of HPA-3b (Bak(b)).

Cefoselis, a ?-lactam antibiotic, easily penetrates the blood-brain barrier and causes seizure independently by glutamate release

Cefoselis is a widely used beta-lactam antibiotic, but occasionally induces seizures and convulsion in elder and renal failure patients. However, beta-lactams are known not to pass through the blood-brain barrier (BBB). In this study, we examined the BBB penetration of cefoselis in normal and renal failure rats by means of brain microdialysis. Cefoselis was dose-dependently appeared in brain extracellular fluid in proportion to its blood level. The elimination constant from brain extracellular fluid (apparent) was slightly lower than that from blood. These results indicated that cefoselis might penetrate the BBB or be discharged by a certain transport system. In contrast to the result of cefoselis, cefazolin, a leading drug of cephalosporins, could not be detected in the brain extracellular fluid after an intravenous injection. In renal dysfunction rats, the elimination half-lives of cefoselis from both blood and brain were extensively prolonged. This would be one of responsible factors inducing seizures seen in patients. However, the additional factor, such as decrease in brain function related to aging, would be involved in seizures in patient received cefoselis, because an extremely high dose was required to induce seizures even in renal failure rats. A local administration of cefoselis into the hippocampus through the microdialysis probe caused a striking elevation of extracellular glutamate, with a minimum increase in gamma-aminobutyric acid (GABA). However, a systematic cefoselis administration via the tail vein did not elevate extracellular glutamate and GABA concentrations in the hippocampus of renal failure rats that exhibited marked seizures. These results suggested that not the stimulation of glutamate release, but the blockade of GABA receptors might be responsible for the seizure induced by cefoselis.

Microarray analysis of hepatic gene expression during long-term cholestasis induced by common bile duct ligation in rats

Cholestasis is one of the major liver diseases and results in progressive liver fibrosis and cirrhosis. In this study, the transcriptional response of the liver to common bile duct ligation in rats was examined by cDNA microarray analysis, and 134 genes for which expression was altered during long-term cholestasis were identified. Clustering analysis of these genes for multiple time-point data yielded 7 different patterns in which a large portion of the genes was classified into 3 clusters. Two clusters consisted of up-regulated genes, including genes that may be related to disruption of lipid metabolism and liver fibrosis observed in the early stage of cholestasis, and the other cluster consisted of down-regulated genes, including a gene that has been thought to be involved in the mechanism of cell protection against accumulation of bile acids. Since the expression patterns of these genes appear to reflect molecular features of cholestasis. Characterization of the genes identified in this study may shed further light on the physiological and pathological characteristics of long-term cholestasis.

Recombinant osteogenic protein-1 upregulates extracellular matrix metabolism by rabbit annulus fibrosus and nucleus pulposus cells cultured in alginate beads

This study was performed to determine if recombinant human osteogenic protein-1 (rhOP-1) is effective in promoting matrix synthesis and matrix formation by rabbit nucleus pulposus (NP) and annulus fibrosus (AF) cells cultured in alginate beads. The effects of culturing the cells in the presence of various concentrations of rhOP-1 were assessed by measuring changes in cell proliferation, proteoglycan (PG) and collagen synthesis and mRNA expression, and in the matrix contents of PG and collagen, as indicators of matrix accumulation. At high concentrations, rhOP-1 had a moderate mitogenic effect on both NP and AF cells. It also stimulated the synthesis of PG and collagen in a dose-dependent manner: this was associated with a corresponding increase in the expression of mRNA for aggrecan core protein and collagen type II. The stimulatory effect of rhOP-1 on PG synthesis was more pronounced than that on collagen synthesis. Continuous treatment with rhOP-1 led to an increase in the total DNA, PG and collagen contents in both NP and AF cultures. The results presented here provide evidence of the ability of rhOP-1 to stimulate the metabolism of both rabbit AF and NP cells cultured in alginate beads.

Mexiletine carbonyloxy beta-D-glucuronide: a novel metabolite in human urine

1. The study was performed to isolate and characterize a glucuronic acid conjugate of mexiletine that releases mexiletine on acid hydrolysis from urine samples obtained from healthy volunteers following a single oral dose of mexiletine. 2. The [M-H]- ion of the isolated metabolite was observed at m/z 398 in the negative electrospray ionization mass spectrum. This mass number was 44 higher than that of the product generated when mexiletine is subjected to direct glucuronidation. In positive-ion mode, collision-induced dissociation of the quasimolecular ion [M+NH4]+, m/z 417, gave product ions at m/z 224, 180 and 58. These mass spectral data indicated that the metabolite contained a carbonyloxy moiety in its structure in addition to mexiletine and a glucuronic acid moiety. 3. The presence of this carbonyloxy moiety was further supported by the following chemical reactions. When the metabolite was hydrolysed with an aqueous solution of 1 M sodium hydroxide at room temperature, mexiletine was released, whereas the N-methoxycarbonyl derivative of mexiletine was obtained after treatment of the metabolite with methanolic sodium hydroxide solution. 4. The results indicated that the structure of the isolated metabolite was the N-carbonyloxy beta-D-glucuronic acid conjugate of mexiletine.

Characteristics of skin wrinkling and dermal changes induced by repeated application of squalene monohydroperoxide to hairless mouse skin

We have studied the effect of squalene monohydroperoxides (Sq-OOH), initial products of UV-peroxidated squalene, on the skin of hairless mice. Repeated topical application of 10 mM Sq-OOH to hairless mice for 15 weeks induced definite skin wrinkling. When image analysis was used to compare wrinkle formation induced by ultraviolet B (UVB) irradiation and Sq-OOH treatment, the degree of wrinkling in exposed skin was seen to be similar. However, the characteristics of wrinkles induced by either method differed markedly with regard to direction and distribution. Biochemical analysis revealed a significant decrease in collagen content per unit area and mass in Sq-OOH-treated skin, whereas no changes per unit area and decrease in collagen per unit mass were observed in UVB-irradiated skin. As for glycosaminoglycan (GAG) content per unit area, significant increases were observed in both Sq-OOH-treated skin and UVB-irradiated skin. These changes were not induced by organic hydroperoxides such as TERT-butylhydroperoxide or cumene hydroperoxide treatment. Histological observation revealed epidermal hyperplasia and dermal alterations such as collagen degradation and GAG increases in Sq-OOH-treated skin. Histological changes induced by Sq-OOH were not as pronounced as those induced by UVB irradiation. These results clearly suggest that the wrinkling and changes in dermal collagen content induced by Sq-OOH are qualitatively different to those induced by UVB exposure. This may provide a useful model for the study of skin aging, particularly with regard to collagen content.

The risk of persistent carriage of methicillin-resistant Staphylococcus aureus in hematopoietic stem cell transplantation

The clinical course of hematopoietic stem cell transplantation (HSCT) recipients was retrospectively analyzed to determine whether carriage of methicillin-resistant Staphylococcus aureus (MRSA) is a risk factor for MRSA infection during the neutropenic period. We studied four patients in whom MRSA colonies developed before HSCT. Two patients were previously diagnosed as having MRSA infection and two were carriers of MRSA. We tried to eliminate MRSA before HSCT and succeeded in eradication in two patients. MRSA infection did not develop in one patient who received prophylactic administration of vancomycin (VCM), but MRSA-induced phlegmon developed during neutropenia in one patient who did not receive prophylaxis. Of the other two patients who had been persistently positive for MRSA, MRSA did not develop in one patient who received prophylaxis, but the another patient who did not receive prophylaxis died from MRSA-induced sepsis in the early post-transplant period. We therefore recommend that MRSA be eliminated by prophylactic administration of anti-MRSA drugs such as VCM before HSCT when patients have persistent MRSA.

Bifidobacterium-fermented soy milk extract stimulates hyaluronic acid production in human skin cells and hairless mouse skin

We examined the effects of Bifidobasterium-fermented (BE) and nonfermented (SME) soy milk extracts on the production of hyaluronic acid (HA) in vitro and in vivo. BE, but not SME, significantly enhanced the production of HA in monolayer and organotypic cultures of human keratinocytes, in cultures of human skin fibroblasts, and in hairless mouse skin following topical application for 2 weeks. In the organotypic cultures formed by a similar structure to human epidermis, BE also extended the distribution of HA. Genistein and daidzein, known to stimulate HA production, were detected in BE at a concentration of 0.18 and 0.07 mM, respectively, but not in SME. Therefore, BE has the potential to enhance HA production in the epidermis and dermis, mainly due to genistein released from its glycoside during fermentation. BE is expected to prevent the age-dependent loss of cutaneous HA.

Changes of cervical spinal cord and cervical spinal canal with age in asymptomatic subjects

STUDY DESIGN

Prospective study on magnetic resonance imaging (MRI) and radiographic findings of the cervical spine.

OBJECTIVE

To elucidate the age-related changes of the cervical spinal cord and the cervical spinal canal and the relationship between the spinal cord and the spinal canal in asymptomatic subjects using MRI and radiography.

SETTING

Tokyo, Japan.

METHODS

The transverse area of the cervical spinal cord and the ratio of the anteroposterior diameter to the transverse diameter (RAPT) were investigated, using MRI in 229 asymptomatic subjects. The sagittal spinal canal diameter and anteroposterior diameter of the cervical vertebral body were also measured on plain lateral radiographs. The canal body ratio (CBR), which was defined as the diameter of the spinal canal divided by that of the vertebral body, was calculated.

RESULTS

The transverse spinal cord area correlated negatively with age. RAPT did not correlate with age. The CBR correlated negatively with age. The correlation between spinal cord area and CBR was significant but weak and the correlation between RAPT and CBR was not significant.

CONCLUSION

The transverse area of the cervical spinal cord measured by MRI decreased with age, while RAPT remained unchanged. The bony spinal canal became narrower with age. The spinal cord area and the shapes of the spinal cord were independent from the spinal canal diameter in asymptomatic subjects. These facts should be considered when evaluating radiological findings in patients with cervical spinal disorders.

Platelet recovery in patients with idiopathic thrombocytopenic purpura after eradication of Helicobacter pylori

The relationship between Helicobacter pylori infection and idiopathic thrombocytopenic purpura (ITP) has been investigated in several studies. We investigated the prevalence of H. pylori infection and the clinical effects of eradication in 22 Japanese patients with chronic ITP. H. pylori infection was found in 14 (63.6%) of the patients by histologic and culture examinations of biopsy samples obtained by gastrointestinal endoscopy. H. pylori was eradicated by proton pump inhibitors and 2 kinds of antibiotics in 13 (92.9%) of the 14 patients in whom the results of treatment could be evaluated. Five (38.4%) of those 13 patients had platelet recovery (platelet count of more than 100 x 10(9)/L and an increase of more than 30 x 10(9)/L with respect to the baseline value) after eradication. The median follow-up period was 15 months. One patient who had a complete response had a partial relapse after cessation of prednisolone treatment without any evidence of H. pylori reinfection. Another patient, in whom H. pylori was not eradicated even after 2 treatment sessions, had a partial response after treatment. A screening examination for H. pylori infection may be necessary for Japanese patients with newly diagnosed ITP. Although the exact mechanism underlying platelet recovery after H. pylori eradication is not clear, the results of this study indicated that H. pylori eradication treatment is a good option for some patients with chronic ITP.

del11(p11-13) with overexpression of Wilms' tumor gene during leukemic transformation of myelodysplastic syndrome

We report a case of leukemic transformation from myelodysplastic syndrome (MDS) with a sole chromosome abnormality of del11(p11-13). The patient had been diagnosed as having MDS (refractory anemia with excess of blast cells, RAEB) in May 1998. At that time, cytogenetic analysis of bone marrow cells showed a normal karyotype. The patient received sequential chemotherapy with low-dose cytosine arabinoside (AraC) and macrophage colony-stimulating factor (M-CSF). Complete remission was obtained with this treatment, but the disease gradually progressed after June 1999. Cytogenetical analysis showed del11(p11-13) in 6 of 40 cells analyzed at that time, and the disease had evoluted to overt leukemia in December 1999 with a gradual increase in the abnormal clone. Furthermore, mRNA of the WT1 gene located at chromosome 11p13 was overexpressed during leukemic transformation, whereas it was not detected at the time of the initial diagnosis of MDS (RAEB) in May 1998. It was thought that this chromosome deletion and overexpression of WT1 resulted in the leukemic transformation in this patient. This is the first case report of del11(p11-13) being considered to be the primary cause of leukemic transformation from MDS.

Pharmacokinetics, toxicokinetics, distribution, metabolism and excretion of linezolid in mouse, rat and dog

1. Linezolid (ZYVOX), the first of a new class of antibiotics, the oxazolidinones, is approved for treatment of Gram-positive bacterial infections. 2. The aim was to determine the absorption, distribution, metabolism and excretion (ADME) of linezolid in mouse, rat and dog in support of preclinical safety studies and clinical development. 3. Conventional replicate study designs were employed in animal experiments, and biofluids were assayed by HPLC or HPLC-MS. 4. Linezolid was rapidly absorbed after p.o. dosing with an p.o. bioavailability of > 95% in rat and dog, and > 70% in mouse. Twenty-eight-day i.v./p.o. toxicokinetic studies in rat (20-200mg kg(-1) day(-1)) and dog (10-80 mg kg(-1) day(-1)) revealed neither a meaningful increase in clearance nor accumulation upon multiple dosing. 5. Linezolid had limited protein binding (<35%) and was very well distributed to most extravascular sites, with a volume of distribution at steady-state (V(ss)) approximately equal to total body water. 6. Linezolid circulated mainly as parent drug and was excreted mainly as parent drug and two inactive carboxylic acids, PNU-142586 and PNU-142300. Minor secondary metabolites were also characterized. In all species, the clearance rate was determined by metabolism. 7. Radioactivity recovery was essentially complete within 24-48 h. Renal excretion of parent drug and metabolites was a major elimination route. Parent drug underwent renal tubular reabsorption, significantly slowing parent drug excretion and allowing a slow metabolic process to become rate-limiting in overall clearance. 8. It is concluded that ADME data were relatively consistent across species and supported the rat and dog as the principal non-clinical safety species.

Pneumococcal purulent genual arthritis after allogeneic bone marrow transplantation

A 21-year-old male patient with non-Hodgkin's lymphoma (diffuse large T-cell type, clinical stage IV) received allogeneic bone marrow transplantation (BMT) from a partially HLA-mismatched unrelated donor in July 1998 and achieved complete remission. Thereafter, he suffered from chronic graft-versus-host disease (GVHD) and was continuously administered immunosuppressive drugs for a long time. Two years after the BMT, he complained of severe pain in the right knee, which was swollen, and was diagnosed as having pneumococcal purulent genual arthritis. He underwent arthroscopic synovectomy and was administered systemic and intra-articular antibiotics, leading to a gradual improvement. Streptococcal infections are often seen in patients in the late phase after allogeneic BMT because of immunodeficiency associated with chronic GVHD and hyposplenism. Most streptococcal infections are respiratory tract infections and septicemia, and there have been very few reports on cases of purulent genual arthritis. Administration of prophylactic antibiotics and control of chronic GVHD, which is a risk factor of pneumococcal infection, seem to be important to prevent purulent genual arthritis.

Successful allogeneic bone marrow transplantation from an HBV-positive donor into an HBV-positive recipient using lamivudine

A 21-year-old woman with severe aplastic anemia underwent allogeneic bone marrow transplantation from an HLA-identical sibling donor. The patient also had chronic hepatitis B and the donor was an HBV carrier. To decrease HBV and improve hepatic dysfunction before BMT, the patient had received lamivudine for 6 months. After marrow transfusion, administration of lamivudine was continued to inhibit replication of donor-derived HBV. The patient showed hematological engraftment on day 13 without any serious liver dysfunction. Eight months after BMT, she is now alive and well without chronic liver GVHD or reactivation of hepatitis B. HBV-DNA was not detected in the patient's serum. Administration of lamivudine to a BMT recipient with chronic hepatitis B may be a safe and promising way to prevent fatal liver dysfunction in the setting of allogeneic BMT, even in the event of BMT from an HBV-positive donor.

Lamivudine treatment for reverse seroconversion of hepatitis B 4 years after allogeneic bone marrow transplantation

Reverse seroconversion of hepatitis B virus (HBV) after allogeneic BMT is rare. We present a case of HBV reactivation late after allogeneic BMT which responded well to lamivudine therapy. A 35-year-old woman with CML received an allogeneic BMT. Before BMT, the patient had immunity to HBV, with serum antibodies against hepatitis B surface antigen (HBsAb), and the donor was completely negative for HBV. Four years after BMT, acute hepatitis occurred with a detectable level of HBV-DNA. Lamivudine rapidly reduced transaminase and bilirubin levels, and serum HBV-DNA decreased to negative. Retrospective analysis revealed that there had been a gradual decrease in serum HBsAb titers after BMT. Administration of lamivudine immediately after HBV replication may be more effective than vaccination of hepatitis B surface antigen-negative donors before BMT.

Effects of CYP2C19 genotypic differences in the metabolism of omeprazole and rabeprazole on intragastric pH

BACKGROUND

Omeprazole is mainly metabolized in the liver by CYP2C19, a genetically determined enzyme, whereas rabeprazole is mainly reduced non-enzymatically and partially metabolized by CYP2C19. The therapeutic effects of rabeprazole are therefore assumed to be less affected by an individual's CYP2C19 status.

AIM

To investigate the acid inhibitory effects and plasma levels of omeprazole and rabeprazole with reference to different CYP2C19 genotypes.

METHODS

Fifteen healthy volunteers took a daily dose of 20 mg of omeprazole or rabeprazole for 8 days. On post-dose days 1 and 8, 24-h profiles of intragastric pH were recorded and plasma concentrations of omeprazole, rabeprazole and their metabolites were determined.

RESULTS

After single and repeated doses of omeprazole, the intragastric pH values and plasma concentrations of omeprazole and its metabolites were significantly dependent on the CYP2C19 genotype. Significant differences in the same kinetic and dynamic parameters were also observed after single doses of rabeprazole. Although the plasma levels of rabeprazole differed among the different CYP2C19 genotype groups after repeated doses, no significant differences in intragastric pH values were observed.

CONCLUSIONS

The acid inhibitory effects of omeprazole and rabeprazole are significantly dependent on the CYP2C19 genotype status, as well as on their intrinsic pharmacokinetic and pharmacodynamic characteristics and dosing schemes.

Effect of polyacetylenes on the neurite outgrowth of neuronal culture cells and scopolamine-induced memory impairment in mice

Polyacetylenic alcohols and their linoleates isolated from Panax ginseng C. A. MEYER and Cirsium japonicum DC., of which the lipophilic extracts had been found to affect the neuritogenesis of cultured paraneurons, were demonstrated to have a significant neuritogenic effect on PC12h and Neuro2a cells. Panaxynol and the acetylenic triol in particular were highly efficient at concentrations > or = 2 microm. Panaxynol (20 mg/kg/d, i.p., for 3 d) was confirmed to improve scopolamine-induced memory deficit in mice (Y-maze task). It is suggested that the promotion of neuritogenesis in cultured paraneurons by the addition of panaxynol is related its ability to improve memory deficits in animals.

Prevention of the neurotoxicity of the amyloid beta protein by genipin

Genipin, which was shown in our previous investigation to have prominent neuritogenic activity in paraneurons such as PC12h cells, was studied to determine whether it could prevent the toxicity of Alzheimer's amyloid beta protein (Abeta) in cultured hippocampal neurons. Increased release of lactate dehydrogenase from hippocampal neurons after 2 d of Abeta25-35 administration was prevented dose dependently by the addition of genipin 20-40 microm. Morphological observations and trypan blue staining of cells confirmed the protection of hippocampal neurons from Abeta toxicity by genipin. Geniposide had less effect in preventing Abeta toxicity.