Predicting the Readmission and Mortality in Older Patients Hospitalized with Pneumonia with Preadmission Frailty.

BACKGROUND: In older people, frailty has been recognized as an important prognostic factor. However, only a few studies have focused on multidimensional frailty as a predictor of mortality and readmission among inpatients with pneumonia. OBJECTIVE: The present study aimed to assess the association between preadmission frailty and clinical outcomes after the hospitalization of older patients with pneumonia. DESIGN: Single-center, retrospective case-control study. SETTING: Acute phase hospital at Kobe, Japan. PARTICIPANTS: The present study included 654 consecutive older inpatients with pneumonia. MEASUREMENTS: Frailty status before admission was assessed using total Kihon Checklist (KCL) score, which has been used as a self-administered questionnaire to assess comprehensive frailty, including physical, social, and cognitive status. The primary outcome was a composited 6-month mortality and readmission after discharge. RESULTS: In total, 330 patients were analyzed (median age: 79 years, male: 70.4%, median total KCL score: 10 points), of which 68 were readmitted and 10 died within 6 months. After multivariate analysis, total KCL score was associated with a composited 6-month mortality and readmission (adjusted hazard ratio, 1.07; 95% confidence interval, 1.02-1.12; p = 0.006). The cutoff value for total KCL score determined by receiver operating characteristic curve analysis was 15 points (area under the curve = 0.610). The group with a total KCL score ≥ 15 points had significantly higher readmission or mortality rates than the groups with a total KCL score < 15 points (p < 0.001). CONCLUSIONS: Preadmission frailty status in older patients with pneumonia was an independent risk factor for readmission and survival after hospitalization.

Visualization and quantification of anastomotic perfusion in colorectal surgery using near-infrared fluorescence.

BACKGROUND: Anastomotic leakage (AL) is one of the most troublesome complications in colorectal surgery. Recently, near-infrared fluorescence (NIRF) imaging has been used intraoperatively to detect sentinel lymph nodes and visualize the blood supply at the region of interest (ROI). The aim of this study was to evaluate the role of visualization and quantification of bowel perfusion around the anastomosis using NIRF system in predicting AL. METHODS: A prospective study was conducted on patients who had laparoscopic surgery for colorectal cancer at our institution. Perfusion of the anastomosis was evaluated with NIRF imaging after intravenous injection of indocyanine green (ICG). The time course of fluorescence intensity was recorded by an imaging analyzer We measured the time from ICG injection to the beginning of fluorescence (T0), maximum intensity (Imax), time to reach Imax (Tmax), time to reach Imax 50% ([Formula: see text]) and slope (S) after the anastomosis. RESULTS: Tumor locations were as follows; cecum: 2, ascending colon: 2, transverse colon: 7, descending colon: 1, sigmoid colon: 2, rectosigmoid colon: 3 and rectum: 6 (one case with synchronous cancer). All operations were performed laparoscopically. Four patients were diagnosed with or suspected to have AL (2 patients with grade B anastomotic leakage after low anterior resection, 1 patient with minor leakage in transverse colon resection and 1 patient needing re-anastomosis intraoperatively in transverse colon resection). T0 was significantly longer in the AL group than in patients without AL (64.3 ± 27.6 and 18.2 ± 6.6 s, p = 2.2 × 10-3). CONCLUSIONS: Perfusion of the anastomosis could be successfully visualized and quantified using NIRF imaging with ICG. T0 might be a useful parameter for prediction of AL.

Risk factors for neutropenia with lenalidomide plus dexamethasone therapy for multiple myeloma.

Neutropenia may develop as an adverse event in patients with multiple myeloma receiving lenalidomide (LEN) plus dexamethasone (DEX) therapy. In the present study, we examined the risk factors associated with grade 3/4 neutropenia during the first cycle of LEN plus DEX therapy. We observed that hemoglobin level (≤ 8.5 g/dl) was a significant risk factor for grade 3/4 neutropenia during the first cycle of therapy (odds ratio: 19.40; 95% confidence interval: 2.68-141.00; p < 0.01). thus, our findings suggest that determining the hemoglobin level could be useful in the risk management for neutropenia in patients receiving LEN plus DEX therapy.

Randomized clinical trial of defaecatory function after anterior resection for rectal cancer with high versus low ligation of the inferior mesenteric artery.

BACKGROUND: Defaecatory function is often poor after anterior resection. Denervation of the neorectum following high ligation of the inferior mesenteric artery (IMA) is a possible cause of impaired defaecatory function. The purpose of this randomized clinical trial was to clarify whether the level of ligation of the IMA in patients with rectal cancer affects defaecatory function. METHODS: Between 2008 and 2011, patients who underwent anterior resection for rectal cancer were randomized to receive either high or low ligation of the IMA. The primary endpoint was to demonstrate the superiority of low ligation in terms of defaecatory function. RESULTS: One hundred patients were enrolled in the study; 51 were randomized to high ligation of the IMA and 49 to low ligation. There were no differences between the groups in terms of clinical data, except tumour stage, which was more advanced in the high-ligation group (P = 0·046). Nor were there any differences in defaecatory function, self-assessment of defaecation, Faecal Incontinence Quality of Life scale or continence score between groups at 3 months and 1 year. The number of harvested lymph nodes was similar. The rate of symptomatic anastomotic leakage was 16 per cent in the high-ligation group and 10 per cent in the low-ligation group (P = 0·415). CONCLUSION: The level of ligation of the IMA in patients with rectal cancer did not affect defaecatory function or the incidence of postoperative complications. REGISTRATION NUMBER: NCT00701012 (http://www.clinicaltrials.gov).

CHIPS for genetic testing to improve a regional clinical genetic service.

In current practice of clinical genetics, molecular diagnosis has become more widely used than ever before. DNA diagnosis is important for appropriate medical care of the patient, and proper genetic counseling to the family. However, genetic testing of orphan disease cannot always be performed easily. In multiple congenital anomalies (MCA) syndromes by monogenic cause, the broad mutational spectrum and large size of responsible genes often make molecular diagnosis expensive and cumbersome. We solve this problem with on-demand genetic testing by CHIPS (CEL nuclease mediated heteroduplex incision with polyacrylamide gel electrophoresis and silver staining) technology, which is the ultimately conventional and economical mutation screening system. In this article, we show eight patients with MCA syndromes who were recently treated at our hospital, and demonstrate that CHIPS successfully offers efficient and inexpensive genetic testing and facilitates clinical genetic service in our local region.

Correlation of axillary osmidrosis to a SNP in the ABCC11 gene determined by the Smart Amplification Process (SmartAmp) method.

Axillary osmidrosis (AO) is caused by apocrine glands secretions that are converted to odouriferous compounds by bacteria. A potential link between AO and wet earwax type has been implicated by phenotype-based analysis. Recently, a non-synonymous single nucleotide polymorphism (SNP) 538G> A (Gly180Arg) in the human adenosine triphosphate (ATP)-binding cassette (ABC) transporter ABCC11 gene was found to determine the type of earwax. In this context, we examined a relationship between the degree of AO and the ABCC11 genotype. We have genotyped the SNP 538G> A in a total of 82 Japanese individuals (68 volunteers and 14 AO patients) by both DNA sequencing and the recently developed Smart Amplification Process (SmartAmp). The degree of AO in Japanese subjects was associated with the genotype of the ABCC11 gene as well as wet earwax type. In most AO patients investigated in this study, the G/G and G/A genotypes well correlated with the degree of AO, whereas A/A did not. The specific SmartAmp assays developed for this study provided genotypes within 30 min directly from blood samples. In East Asian countries, AO is rather infrequent. Although the judgement of the degree of AO prevalence is subjective, the SNP 538G> A in ABCC11 is a good genetic biomarker for screening for AO. The SmartAmp method-based genotyping of the ABCC11 gene would provide an accurate and practical tool for guidance of appropriate treatment and psychological management for patients.

Reg IV is a serum biomarker for gastric cancer patients and predicts response to 5-fluorouracil-based chemotherapy.

Regenerating gene family, member 4 (Reg IV), a secreted protein, is overexpressed in several cancers, including gastric cancer (GC). In the present study, we measured Reg IV levels in sera from patients with GC by enzyme-linked immunosorbent assay. We also examined the effect of forced Reg IV expression on the apoptotic susceptibility to 5-fluorouracil (5-FU). Forced expression of Reg IV inhibited 5-FU-induced apoptosis. Induction of Bcl-2 and dihydropyrimidine dehydrogenase was involved in inhibition of apoptosis. Among 36 GC patients treated with a combination chemotherapy of low-dose 5-FU and cisplatin, all 14 Reg IV-positive patients showed no change or disease progression. The serum Reg IV concentration was similar between healthy individuals (mean+/-s.e., 0.52+/-0.05 ng/ml) and patients with chronic-active gastritis (0.36+/-0.09 ng/ml). However, the serum Reg IV concentration in presurgical GC patients was significantly elevated (1.96+/-0.17 ng/ml), even at stage I. The diagnostic sensitivity of serum Reg IV (36.1%) was superior to that of serum carcinoembryonic antigen (11.5%) or carbohydrate antigen 19-9 (13.1%). These results indicate that expression of Reg IV is a marker for prediction of resistance to 5-FU-based chemotherapy in patients with GC. Serum Reg IV represents a novel biomarker for GC.

Down-regulation of the claudin-18 gene, identified through serial analysis of gene expression data analysis, in gastric cancer with an intestinal phenotype.

Gastric cancer (GC) is one of the most common malignancies worldwide. Genes whose expression is down-regulated in GC may be tumour suppressor genes. In the present study, genes with decreased expression in GC were screened for by serial analysis of gene expression (SAGE) data analysis and reverse transcription (RT)-polymerase chain reaction (PCR), and CLDN18 (encoding claudin-18) was identified. Quantitative RT-PCR revealed that expression of CLDN18 was down-regulated in 13 (56.5%) of 23 GCs. Immunostaining showed that normal gastric mucosa and Paneth cells of the duodenum expressed claudin-18 on cell membranes. Expression of claudin-18 was reduced in several intestinal metaplasias of the stomach. Of 20 samples of gastric adenoma, 18 (90.0%) showed decreased claudin-18 expression. Down-regulation of claudin-18 was observed in 84 of 146 GCs (57.5%) and correlated with poor survival in 65 advanced GCs (p = 0.0346). In addition, expression of the gastric and intestinal phenotypes of GC was examined by immunostaining for MUC5AC, MUC6, MUC2, and CD10. Of 38 GCs showing only the intestinal phenotype, down-regulation of claudin-18 was observed in 28 (73.7%), whereas in the remaining 108 GC cases, down-regulation of claudin-18 was observed in 56 (51.9%) (p = 0.0224). These results indicate that claudin-18 is a good marker of poor survival in GC. Down-regulation of claudin-18 may be involved in GCs with an intestinal phenotype, and may be an early event in gastric carcinogenesis.

Systematic search for gastric cancer-specific genes based on SAGE data: melanoma inhibitory activity and matrix metalloproteinase-10 are novel prognostic factors in patients with gastric cancer.

Gastric cancer (GC) is one of the most common malignancies worldwide. Genes expressed only in cancer tissue will be useful molecular markers for diagnosis and may also be good therapeutic targets. However, little is known about cancer-specific genes, at least in GC. In this study, we searched for GC-specific genes by serial analysis of gene expression (SAGE) data analysis and quantitative reverse transcription (RT)-PCR. Comparing GC SAGE libraries with those of various normal tissues in the SAGEmap database, we identified 54 candidate GC-specific genes. Quantitative RT-PCR analysis of these candidates revealed that APin protein (APIN), taxol resistance-associated gene 3 (TRAG3), cytochrome P450, family 2, subfamily W, polypeptide 1 (CYP2W1), melanoma inhibitory activity (MIA), matrix metalloproteinase-10 (MMP-10), dickkopf homolog 4 (DKK4), GW112, regenerating islet-derived family, member 4 (REGIV), and HORMA domain-containing 1 (HORMAD1) were expressed much more highly in GC than in 14 kinds of normal tissues. Immunohistochemical staining for MIA, MMP-10, and DKK4 was found in 47 (31.1%), 68 (45.0%), and two (1.3%) of 151 GCs, respectively, and staining for both MIA and MMP-10 was correlated with poor prognosis in advanced GC (P=0.0001 and 0.0141, respectively). Moreover, enzyme-linked immunosorbent assay showed high levels of MMP-10 (65/69, 94.2%) in serum samples from patients with GC. Levels of MIA were raised in a small proportion of serum samples from patients with GC (4/69, 5.8%). In Boyden chamber invasion assays, MIA-transfected GC cells were up to three times more invasive than cells transfected with empty vector. Taken together, these results suggest that MMP-10 is a good marker for the detection of GC and that MIA and MMP-10 are prognostic factors for GC. As expression of MIA and MMP-10 is narrowly restricted in cancer, these two molecules may be good therapeutic targets for GC.

Correlation of inhaled nitric-oxide induced reduction of pulmonary artery pressure and vascular changes.

The purpose of the present study was to determine the relationship between hypertensive pulmonary vascular remodelling and the changes in mean pulmonary artery pressure (mPAP) during low-dose nitric oxide (NO) inhalation. Rats were exposed to chronic hypobaric hypoxia (air at 50.5 kPa (380 mmHg), 10% oxygen, for 5-29 days) to induce chronic pulmonary hypertension (PH) with pulmonary vascular structural changes. After the chronic hypoxic exposure, the rats had an indwelling pulmonary artery catheter inserted and changes in mPAP with NO were correlated to morphometrical analysis of pulmonary vascular changes. All concentrations of inhaled NO (0.1-2.0 parts per million) reduced mPAP with a similar per cent reduction from baseline mPAP in PH rats, while no changes were observed in control rats. During NO inhalation in PH rats, the absolute value of the decrease in mPAP, but not per cent reduction in mPAP, significantly correlated with baseline mPAP, the percentage of muscularised arteries at the alveolar wall level and at the alveolar duct level, and the per cent medial wall thickness of muscularised arteries. In the chronic hypoxic pulmonary hypertension model, the severity of pulmonary vascular remodelling did not alter the reactivity of the pulmonary arteries to nitric oxide and might, in part, determine the magnitude of nitric-oxide induced absolute reduction in mean pulmonary artery pressure.

Regulation of the muscle-specific expression and function of an ascidian T-box gene, As-T2.

The Tbx6 T-box genes are expressed in somite precursor cells of vertebrate embryos and are essential for the differentiation of paraxial mesoderm. However, it is unclear how spatial regulation of the gene expression is controlled and how the genes function to promote muscle differentiation. The Tbx6-related gene As-T2 of the ascidian Halocynthia roretzi is first expressed very transiently in endodermal cells around the 32- approximately 44-cell stage, is then expressed distinctly and continuously in muscle precursor cells, and later in epidermal cells situated in the distal tip region of the elongating tail. We now show that inhibition of As-T2-mediated transcriptional activation by microinjection of As-T2/En(R) into one-cell embryos resulted in suppression of the expression of the muscle-specific actin gene (HrMA4) and myosin heavy chain gene (HrMHC), but the injection did not affect the differentiation of endodermal cells or tail tip cells, suggesting that the primary function of As-T2 is associated with muscle cell differentiation. The 5' flanking region of As-T2 contains two promoter modules that regulate its specific expression: a distal module that responsible for its specific expression in the tail, and a proximal module required for its muscle-specific expression. Around the proximal module, there are two putative T protein-binding motifs (TTCACACTT). Co-injection of an As-T2/lacZ construct with or without the T-binding motifs together with As-T2 mRNA revealed that these motifs are essential for autoregulatory activation of the gene itself. In addition, we found that the minimal promoter regions of HrMA4 and HrMHC contain T-binding motifs. Co-injection of HrMA4/lacZ or HrMHC/lacZ containing the T-binding motifs along with As-T2 mRNA revealed that As-T2 protein binds to these motifs to upregulate the gene activity. Taking into account the recent finding of maternal molecules for muscle differentiation, we propose a model for a genetic cascade that includes As-T2 as a regulator of muscle cell differentiation in the ascidian embryo.

Heterodimer formation between the antimicrobial peptides magainin 2 and PGLa in lipid bilayers: a cross-linking study.

The antimicrobial peptides magainin 2 and PGLa, isolated from the skin of the African clawed frog Xenopus laevis, show marked synergism [Westerhoff, H. V., Zasloff, M., Rosner, J. L., Hendler, R. W., de Waal, A., Vaz Gomes, A., Jongsma, A. P. M., Riethorst, A., and Juretic, D. (1995) Eur. J. Biochem. 228, 257-264]. We suggested previously that these peptides form a potent heterodimer composed of either parallel or antiparallel helices in membranes [Matsuzaki, K., Mitani, Y., Akada, K., Murase, O., Yoneyama, S., Zasloff, M., and Miyajima, K. (1998) Biochemistry 37, 15144-15153]. To detect the putative heterodimer by chemical cross-linking, analogues of magainin 2 and PGLa with a Cys residue at either terminus were synthesized. These cross-linking experiments suggested that both peptides form a parallel heterodimer in membranes composed of phosphatidylglycerol/phosphatidylcholine but not in either buffer or a helix-promoting 2,2,2-trifluoroethanol/buffer mixture. The isolated parallel heterodimers exhibited an order of magnitude higher membrane permeabilization activity compared with the monomeric species, indicating that the observed synergism is due to heterodimer formation.

Moving-table reduced-dose gadolinium-enhanced three-dimensional magnetic resonance angiography: velocity-dependent method with three-phase gadolinium infusion.

The purpose of this study was to develop a method for reducing gadolinium dose and suppressing venous overlap in moving-table three-dimensional (3D) magnetic resonance (MR) angiography from the abdomen to the feet. Thirty-one patients underwent three-phase infusion of 16-18 mL of gadolinium: infusion rates and imaging times were determined after taking into account mean blood flow velocity, so that image acquisition was synchronized with peak arterial enhancement at both the first and third stations (velocity-dependent method). Twenty-three other patients underwent slow infusion of 38 mL of gadolinium with fixed acquisition time (high-dose method). The image quality for the two methods was compared. The velocity-dependent method produced good image quality with significantly less venous overlap than the high-dose method, especially in the below-the-knee region (P <.001). The velocity-dependent method provides satisfactory MR angiograms using 16-18 mL of gadolinium in patients having various blood flow velocities.

Polymorphonuclear leukocyte adhesion to articular cartilage is inhibited by cartilage surface macromolecules.

The present studies deal with polymorphonuclear neutrophil (PMN) adhesion inhibitory properties of cartilage surface proteoglycans. Normal human PMN were used in adhesion experiments with bovine cartilage surfaces exposed to neutrophil elastase and reconstituted with fibronectin (Fn) or on plastic-bound Fn. An extract of cartilage surface small proteoglycans (SE) and purified fibromodulin (FM), decorin (DCN), biglycan (BGN), and aggrecan (AGN) on the surface of normal cartilage were used to test for inhibition of Fn-dependent cell adhesion. The PMN did not adhere to intact articular cartilage surfaces, whereas significant adhesion was measured using cartilage explants digested with elastase and reconstituted with Fn. Incubation of elastase-treated, Fn-reconstituted cartilage with 45 microg/ml SE inhibited PMN adhesion by 50.7 +/- 5.8% (P < 0.0001). Addition of 50 microg/ml purified FM to the reconstituted articular surfaces inhibited cell adhesion by 71.2 +/- 13.9% (P < 0.0001). Inhibition of PMN adhesion to plastic-bound Fn was seen with 1.7 microg/ml SE (20.4 +/- 8.0%). Maximal inhibition of 67.4 +/- 14.8% (P < 0.01) was obtained with 17.0 microg/ml SE. With FM, concentrations of 4.3 microg/ml resulted in 34.7 25.2 inhibition (P < 0.001), and maximal inhibition of 66.3 16.2% (P < 0.01) was obtained with 43.0 microg/ml. Similar results were obtained with purified bovine DCN and BGN. The main component of cartilage matrix, AGN, failed to inhibit cell adhesion significantly. The results indicate that macromolecules normally present on articular cartilage surfaces act as a barrier to PMN adhesion. Since cartilage surface proteins are susceptible to breakdown by proteases from synovial fluid inflammatory cells, we postulate that the degradation of this barrier may be responsible for increasing PMN adhesion and subsequent cartilage damage in inflammatory arthritis.

Cross talk of the interferon-alpha/beta signalling complex with gp130 for effective interleukin-6 signalling.

BACKGROUND: Signalling cross talk provides a molecular basis for modulating a given signalling pathway by another, and it is often critical for regulating cellular responses elicited by cytokines. Previously, we reported on the critical role of the IFN-alpha/beta signalling complex, generated by spontaneously produced IFN-alpha/beta, in efficient IFN-gamma signalling. RESULTS: In the present study, we have demonstrated that the IFN-alpha/beta signalling complex also contributes to efficient IL-6 signalling. In fact, IL-6-induced activation of the Stat1 and Stat3 transcription factors is markedly diminished in the absence of the IFN-alpha/beta signalling complex. The induction of several target genes for these factors is also diminished, both in vitro and in vivo. We provide evidence that the cytoplasmic tyrosine residues of IFNAR-1, which remains phosphorylated by a weak IFN-alpha/beta stimulation, provide docking sites for Stat1 and Stat3 to form homo- or heterodimers following IL-6 stimulation. Furthermore, a chemical cross-linking experiment revealed that IFNAR-1 and gp130, a common signal transducer for the IL-6 family of cytokines, exist in close proximity. CONCLUSIONS: The constitutive weak IFN-alpha/beta signal provides a foundation for strong cellular responses to IL-6, IFN-gamma, and possibly other cytokines. Our results also suggest the assembly of cytokine receptor subunits, which may represent a 'receptosome'-like structure, allowing the unique signalling cross talks to occur.

Vascular smooth muscle cell phenotypes in primary pulmonary hypertension.

Primary pulmonary hypertension (PPH) is associated with specific structural alterations, including cellular intimal thickening, intimal fibrosis, and plexiform lesions. To determine the phenotypes of smooth muscle cells (SMCs) in such lesions, the authors conducted an immunohistochemical analysis of lung tissues from two patients with PPH, using two antimuscle actin antibodies, HHF35 and CGA7, and two anti-SMC myosin heavy chain markers, anti-SM1 and anti-SM2 antibodies and related antibodies. Cells that stained positive (+) with HHF35, CGA7, anti-SM1, and anti-SM2 were considered to be SMCs of a mature state. Conversely, those that stained positive with HHF35 and anti-SM1, but weakly positive (+/-) or negative (-) with CGA7 and anti-SM2, were considered to be SMCs exhibiting an immature state. Cellular intimal thickening was composed of SMCs of an immature phenotype (HHF35+, CGA7+/-, SM1+, SM2+/-), accompanied by the expression of fibronectin and the presence of macrophages; intimal fibrosis contained mature SMCs (HHF35+, CGA7+, SM1+, SM2+); and plexiform lesion consisted of proliferative endothelial cells (von Willebrand factor-positive cells, proliferating cell nuclear antigen-positive cells) and underlying immature SMCs (HHF35+, CGA7-, SM1+, SM2-) associated with fibronectin expression and macrophage infiltration. These findings suggest that smooth muscle cells with specific phenotypes may contribute to the development of specific vascular lesions in primary pulmonary hypertension.

Ultrafiltration of the priming blood before cardiopulmonary bypass attenuates inflammatory response and improves postoperative clinical course in pediatric patients.

The priming solution using in cardiopulmonary bypass (CPB) for infants undergoing cardiac surgery includes considerable amounts of stored blood. Our objective was to test the hypothesis that ultrafiltration (UF) of the stored blood before CPB reduces the unfavorable effects of stored blood and the production of inflammatory cytokines. Fifty pediatric patients with congenital heart defects took part in this study. The patients were randomly divided into two groups: the UF (27 pediatric patients who received UF) and control (23 pediatric patients who did not receive UF) groups. UF was performed with a polysulphone ultrafiltrator before CPB. Blood samples were collected immediately before, during, and 1 h after CPB. The levels of cytokines (TNF-alpha, IL-1beta, IL-8), NH3, and bradykinin were determined. The serum concentrations of NH3 and bradykinin decreased significantly after UF. Compared with the control group, the UF group had significantly lower cytokine production. Water balance in UF group was better than that of control group. The UF group received significantly less inotropic support and shorter duration of ventilator support and ICU stay. We conclude that removal of bradykinin and a decrease in the levels of NH3, potassium, and pH play a significant role in reducing water retention and postoperative lung injury. UF of the blood used to prime the circuit for CPB is a safe and efficient method for use in open heart surgery in small pediatric patients.

Mastoid pneumatization of the patulous eustachian tube.

The pathophysiology of the patulous eustachian tube (PET) remains unclear. The degree of mastoid cell pneumatization is considered an indicator of chronic inflammation of the middle ear. We used the mastoid cell area to investigate the relationship between past chronic inflammation of the middle ear cavity and a PET in 84 patients (20 to 83 years old). The mastoid cell size was calculated from radiographs and analyzed relative to the history of otitis media (OM). The controls were 100 normal ears. The patients' mastoid cell size was significantly suppressed versus that of the controls, in both 31 PET cases with and 53 PET cases without past OM. We surmise the possibility that the PET ears had experienced inflammation even when the patients had no history of OM and the tympanic membrane showed no OM sequelae. This study indicates the existence of some relationship between a history of chronic inflammation of the middle ear cavity and a PET.

Stereoselective metabolism of cibenzoline, an antiarrhythmic drug, by human and rat liver microsomes: possible involvement of CYP2D and CYP3A.

Stereoselective metabolism of cibenzoline succinate, an oral antiarrhythmic drug, was investigated on hepatic microsomes from humans and rats and microsomes from cells expressing human cytochrome P450s (CYPs). Four main metabolites, M1 (p-hydroxycibenzoline), M2 (4,5-dehydrocibenzoline), and unknown metabolites M3 and M4, were formed by human and rat liver microsomes. The intrinsic clearance (CL(int)) of the M1 formation from R(+)-cibenzoline was 23-fold greater than that of S(-)-cibenzoline in human liver microsomes, whereas the R(+)/S(-)-enantiomer ratio of CL(int) for M2, M3, and M4 formation was 0.39 to 0.83. The total CL(int) for the formation of the four main metabolites from S(-)- and R(+)-cibenzoline was 1.47 and 1.64 microl/min/mg, respectively, suggesting that the total CL(int) in R(+)-enantiomer was slightly greater than that in S(-)-enantiomer in human liver microsomes. The M1 formation from R(+)-cibenzoline was highly correlated with bufuralol 1'-hydroxylation and CYP2D6 content and was inhibited by quinidine, a potent inhibitor of CYP2D6. Additionally, only microsomes containing recombinant CYP2D6 were capable of M1 formation. These results suggest that the M1 formation from R(+)-cibenzoline was catalyzed by CYP2D6. The formation of M2, M3, and M4 from S(-)- and R(+)-cibenzoline was highly correlated with testosterone 6beta-hydroxylation and CYP3A4 content. Ketoconazole, which is a potent inhibitor of CYP3A4/5, had a strong inhibitory effect on their formation, and the M4 formation from R(+)-cibenzoline was inhibited by quinidine by 45%. The formation of M2 was also inhibited by quinidine by 46 to 52% at lower cibenzoline enantiomers (5 microM), whereas the inhibition by quinidine was not observed at a higher substrate concentration (100 microM). In male rat liver microsomes, ketoconazole and quinidine inhibited the formation of the main metabolites, M1 and M3, >74% and 44 to 59%, respectively. These results provide evidence that CYP3A and CYP2D play a major role in the stereoselective metabolism of cibenzoline in humans and male rats.