Unexpected serum level of vancomycin after oral administration in a patient with severe colitis and renal insufficiency.

OBJECTIVE: To report a case in which the serum concentration of vancomycin (VCM) reached the supratherapeutic range following oral administration in a patient with severe pseudomembranous colitis and renal insufficiency. CASE SUMMARY: A 65-year-old, 70 kg weighing man with severe acute pancreatitis and acute renal failure was subjected to continuous hemodiafiltration (CHDF). CHDF could only be performed intermittently because of the unstable circulation dynamic of this patient. After admission, intravenous VCM therapy was initiated. Thereafter, oral VCM administration was begun (0.5 g every 6 h). Despite the discontinuation of intravenous VCM after the first 2 days of oral VCM, the serum VCM concentration increased gradually to 49.8 mg/l over a period of 2 weeks from the initiation of oral administration (34.4 mg/l). Based on pharmacokinetic analysis, the bioavailability of VCM was estimated to over 33%. Autopsy findings indicated broadly distributed necrosis on the lamina propria of the mucosa throughout all parts of the intestine below the duodenum. DISCUSSION: This case indicates necessity of the careful monitoring after oral high-dose VCM administration in a patient with a broadly distributed necrosis and renal insufficiency. CONCLUSIONS: TDM should be considered according to renal function, the severity of enteritis and the total dosage of oral VCM administration.

[Solitary fibrous tumor of the visceral pleura being suspected of chest wall origin: report of a case].

We report a case of a solitary fibrous tumor (SFT) of the pleura which is suspected of chest wall tumor. A 52-year-old female was admitted to our hospital because of epigastralgia and body weight loss. Chest X-ray and computed tomography showed a circumscribed mass of 35 x 22 mm in diameter arising from the parietal pleura. Positron emission tomography showed uptake valve of 1.5. SFT of chest wall origin was suspected and performed video-assisted thoracic surgery. The pedunculated tumor attached to the visceral pleura. The tumor was diagnosed as a benign SFT in intraoperative diagnosis. Long term clinical follow-up is recommended for patients with SFT, because the tumor recurrence and malignant transformation may occur in tumors with benign histological features.

[Solitary fibrous tumor of the pleura; report of a case].

An 81-year-old male appealed against a feeling of dyspnea, and consulted the hospital. The giant tumor discovered in the thorax and it was enlarging gradually for 7 years. The tumor shadow with a diameter of about 15 cm was noted in right lower lung field on the chest X-ray. A definite diagnosis was not obtained by the needle biopsy. The tumor was found to exist between upper lobe and lower lobe and pressed lower lobe at surgery. The tumor was completely excised with partial resection of the collapsed lower lobe. The tumor was 1,050 g in weight and 18 cm in maximum diameter. Pathological examination showed the irregular and plan-like arrangement of the spindle-shape cell. Immunohistochemical study revealed positive findings for bcl-2 and CD34, negative findings for desmin, ketatin, and alpha-actin. The tumor was diagnosed as malignant solitary fibrous tumor of the pleura due to highly atypical nuclear finding with an abundant nuclear fission or histology.

Predictors of inhalation burn injury using fire site information.

Inhalation burn injury (IBI) is a risk factor for mortality in burn patients. However, it is difficult to diagnose IBI using traditional physical examination alone, especially in prehospital settings. Therefore, facial burn patients are usually treated for suspected IBI. In the present study, we investigated whether fire site information could predict IBI as an alternative to traditional physical examination. This retrospective single-centre analysis involved 27 facial burn patients with suspected IBI who were admitted between 2014 and 2016. The patients were divided into two groups (IBI and non-IBI) according to bronchoscopy findings. Fire site information was compared between the two groups. The IBI (n = 13) and non-IBI (n = 14) groups were compared. Domestic fire was more frequent in the IBI group (69% vs. 29%, P = 0.035). The IBI group included one patient with carboxyhemoglobin ≥10% on admission. Prehospitalization fire site information, particularly domestic fires, might predict IBI in facial burn patients..

L'inhalation de fumées (IF) est un facteur de mortalité chez les brûlés. Son diagnostic clinique est difficile, en particulier en préhospitalier, ce qui fait que les brûlés du visage sont souvent traités comme ayant subi une IF. Cette étude s'est penchée sur les données recueillies sur le site de l'incendie pouvant permettre, mieux que l'examen clinique, de poser le diagnostic d'IF. Cette étude monocentrique rétrospective a revu les dossiers de 27 patients avec brûlures faciales admis entre 2014 et 2016, divisés en 2 groupes (IF, 13 patients et non IF, 14 patients) selon les données endoscopiques. Les données de l'incendie ont ensuite été comparées entre ces 2 groupes. L'incendie était plus fréquemment survenu au domicile dans le groupe IF (65% VS 29%, p = 0,035). Un patient IF avait une HbCO > 10% à l'entrée. La survenue de la brûlure pendant un incendie au domicile pourrait être prédictive d'une IF.

A new form of cytochrome P-450 responsible for mutagenic activation of 2-amino-3-methylimidazo[4,5-f]quinoline in human livers.

Antibodies to P-450IA2 strongly inhibited the mutagenic activation of 2-amino-3-methylimidazo [4,5-f]quinoline (IQ) and 3-amino-1-methyl-5H-pyrido[4,3-b]indole acetate but not aflatoxin B1 in human liver microsomes. The anti-rat P-450IA2 antibodies were capable of recognizing two proteins which show different mobilities on sodium dodecyl sulfate-polyacrylamide gel electrophoresis of human liver microsomes. A new form of cytochrome P-450 (designated P-450-HM4) cross-reactive with anti-rat P-450IA2 antibodies showing that the smaller molecular weight was purified from human liver microsomes by means of the fast-performance liquid chromatography system. The molecular weight of P-450-HM4 was estimated to be 49,000, which was apparently different from that of P-450PA (human P-450IA2). The antibodies to P-450-HM4 did not cross-react with P-450PA (human P-450IA2) but inhibited to various extents the mutagenic activation of IQ in microsomes from human livers. In addition, P-450-HM4 showed significant mutagen-producing activity from IQ in a reconstituted system. Together with these and other results reported previously, it is concluded that at least two forms of cytochrome P-450 [P-450-HM4 and P-450PA (human P-450IA2)] are involved in the mutagenic activation of IQ in human liver.

Metabolic activation of aflatoxin B1 and 2-amino-3-methylimidazo[4,5-f]-quinoline by human adult and fetal livers.

The mutagenic activation of promutagens by human adult and fetal livers was investigated using the umu test system. Among the promutagens studied, aflatoxin B1 (AFB1) and 2-amino-3-methyl-imidazo[4,5-f] quinoline (IQ) were efficiently activated to mutagens by both adult and fetal livers. 7,8-Benzoflavone inhibited the activation of IQ by fetal livers, but the inhibition observed in fetal livers was much less than that observed in adult livers. Antibodies to P450HM1 (P450111A4) and P450HFLa markedly inhibited the activation of AFB1 by adult and fetal livers, respectively. The formation of genotoxic product(s) from IQ in human adult livers was almost completely inhibited by anti-P448H (P4501A2) antibodies but not by anti-P450HM1 antibodies, whereas that in fetal livers was inhibited by both anti-P450HFLa and anti-P450IA2 antibodies. P450HFLa catalyzed the mutagenic activation of both AFB1 and IQ in a reconstituted system. On the contrary, P450HM1 catalyzed the mutagenic activation of AFB1 but not IQ. A preparation of cytochrome P450 partially purified from human fetal livers and cross-reactive with anti-P450IA2 antibodies was found to be active for mutagenic activation of IQ in a reconstituted system. These results indicate that P450HFLa and P450HM1 are mainly involved in the genotoxic product formation from AFB1 in fetal and adult livers, respectively, and that the metabolic activation of IQ in fetal livers is catalyzed by two forms of cytochrome P450, P450HFLa, and cytochrome P450 immunochemically related to P450IA2 but that in adult livers it is mainly catalyzed by cytochrome P450 related to P450IA2.

Changes in axial alignment of the ipsilateral hip and knee after total hip arthroplasty.

AIMS: We investigated changes in the axial alignment of the ipsilateral hip and knee after total hip arthroplasty (THA). PATIENTS AND METHODS: We reviewed 152 patients undergoing primary THA (163 hips; 22 hips in men, 141 hips in women) without a pre-operative flexion contracture. The mean age was 64 years (30 to 88). The diagnosis was osteoarthritis (OA) in 151 hips (primary in 18 hips, and secondary to dysplasia in 133) and non-OA in 12 hips. A posterolateral approach with repair of the external rotators was used in 134 hips and an anterior approach in 29 hips. We measured changes in leg length and offset on radiographs, and femoral anteversion, internal rotation of the hip and lateral patellar tilt on CT scans, pre- and post-operatively. RESULTS: The mean internal rotation increased by 11° (-15° to 46°) and was associated with underlying disease (OA), pre-operative range of internal rotation, gender, surgical approach, leg lengthening, and change of femoral anteversion (adjusted R(2) : 0.253, p < 0.001). The mean lateral patellar tilt increased by 4° (-5° to 14°) and was associated with age, leg lengthening, and increment of hip internal rotation (adjusted R(2): 0.193, p < 0.001). CONCLUSION: Both internal rotation of the hip at rest and lateral patellar tilt are increased after THA. Changes in rotation after THA may affect gait, daily activities, the rate of dislocation of the hip, and ipsilateral knee pain. TAKE HOME MESSAGE: Internal rotation of the hip at rest and lateral patellar tilt increase after THA.

Molecular cloning of monkey P450 1A1 cDNA and expression in yeast.

Monkey P450 1A1 cDNA (MKah1) was isolated from the lambda gt11 cDNA library of a liver from a 3-methylcholanthrene (3MC)-treated crab-eating monkey using a dog P450 1A1 cDNA fragment as a probe. MKah1 was 2453 bp long and contained an entire coding region for a polypeptide of 512 residues. The nucleotide and deduced amino acid sequences of MKah1 displayed 95% and 94% identity with those of the human P450 1A1 gene, respectively. Even in the 3' noncoding region, MKah1 showed 94% homology with human P450 1A1, whereas it showed less than 69% homology with other mammalian P450 1A1. Monkey P450 1A1 mRNA was not detectable in untreated livers, but was induced by polychlorinated biphenyl and 3MC. The expression plasmid (designated as pMKC-1) was constructed by introduction of the coding region of MKah1 into a yeast expression vector (pAM82) containing the promoter of acid phosphatase (APase). Northern blot analysis revealed that monkey P450 1A1 mRNA was expressed in yeast under the control of the APase promoter. Microsomes from yeast transformed by pMKC-1 catalyzed 7-ethoxycoumarin O-deethylation, benzo(a)pyrene hydroxylation and the mutagenic activation of 2-amino-3-methyl-imidazo[4,5-f]quinoline (IQ), 3-amino-1-methyl-5H-pyrido(4,3-b)-indole acetate (Trp-P-2) and 2-amino-6-methyldipyrido(1,2-a:3',2'-d)imidazole acetate (Glu-P-1).

Analyses of a Bacillus subtilis homologue of the Na+/H+ antiporter gene which is important for pH homeostasis of alkaliphilic Bacillus sp. C-125.

Bacillus subtilis was revealed to have a homologous region to the DNA fragment responsible for alkaliphily of alkaliphilic Bacillus sp. C-125 on the genome, as reported previously [1]. The yufT gene on the B. subtilis genome showed a significant similarity with ORF1 of Bacillus sp. C-125, which is related to membrane potential (DeltaPsi)-driven Na+/H+ antiport activity and is important for pH homeostasis in an alkaline condition. Disruption of the yufT gene resulted in the decrease of Na+/H+ antiport activity, and the growth of the yufT disrupted strain was impaired with an increase in the external Na+ concentration. We conclude that the yufT gene encodes a Na+/H+ antiporter, which has a dominant role in the extrusion of cytotoxic Na+.

Purification of cytochrome P-450 from polychlorinated biphenyl-treated crab-eating monkeys: high homology to a form of human cytochrome P-450.

Cytochrome P-450, designated as P-450-MK2, was purified to an electrophoretic homogeneity from polychlorinated biphenyl (PCB)-treated female crab-eating monkeys. P-450-MK2 catalyzed nifedipine and nilvadipine oxidations, at a rate comparable to human P-450-HM1. The N-terminal amino acid sequence of P-450-MK2 was highly homologous to those of P-450-HM1 and NF 25. The antibodies to P-450-HM1 recognized P-450-MK2 and effectively inhibited the activity of testosterone 6 beta-hydroxylase in monkey liver microsomes. These results suggest that a form of cytochrome P-450 corresponding to human P-450-HM1 or P-450NF which belongs to the P450 III gene family is also present in liver microsomes of crab-eating monkeys.

Molecular cloning of monkey liver cytochrome P-450 cDNAs: similarity of the primary sequences to human cytochromes P-450.

Three cDNAs coding for monkey cytochrome P-450 (P450) 2C, 2E and 3A (MKmp13, MKj1 and MKnf2, respectively) were isolated from a lambda gt11 cDNA library of a liver from a 3-methylcholanthrene (3MC)-treated crab-eating monkey, using cDNA fragments for human P450 2C, 2E and 3A as respective probes. MKmp13 and MKnf2 were 1901 and 2032 bp long, containing entire coding regions for polypeptides of 490 and 503 residues, respectively. The deduced N-terminal amino acid sequences of MKmp13 and MKnf2 were identical with those of P450-MK1 and P450-MK2, which had been purified from liver microsomes of untreated and polychlorinated biphenyl (PCB)-treated crab-eating monkeys, respectively. MKj1 was 1508 bp long, encoding a polypeptide of 449 residues, which is presumed to lack N-terminal 45 residues as compared with the sequence for human P450 2E1. Northern blot analysis indicated that monkey P450 2C, 2E and 3A mRNAs were expressed constitutively in monkey livers. P450 2E and 3A mRNAs were induced by both 3MC and PCB, while P450 2C mRNA was induced only by PCB. The deduced amino acid sequences of four monkey cytochrome P-450 cDNAs, including P450 1A1 (MKah1) which we isolated previously, were more than 92% identical with those of corresponding human cytochrome P-450 cDNAs.

Voltage-dependent proton fluxes in liposomes.

Liposomes containing buffered KCl were prepared from bacterial lipids, were diluted into K+-free media and were treated with valinomycin to induce the formation of a diffusion potential (delta psi). Upon formation of such a potential, substantial proton influx was observed, as assayed by the quenching of 9-aminoacridine fluorescence. Complete reversal of fluorescence quenching occurred when the potential was collapsed by addition of KCl or when methylamine was added. Studies of proton influx as a function of the theoretical magnitude of the delta psi indicated that the phenomenon occurred only above a delta psi of about -60 mV. Establishment of a Na+ diffusion potential also resulted in proton influx. Treatment of K+-loaded liposomes with N,N'-dicyclohexylcarbodiimide did not reduce the delta psi-dependent proton influx. Moreover, proton influx could be demonstrated upon imposition of a diffusion potential in liposomes prepared from a synthetic lipid. The proton fluxes associated with generation of a diffusion potential in liposomes may complicate studies of reconstituted systems in which proton translocation should occur, and may affect the magnitude of the electrochemical proton gradient that is operant under some conditions.

Immunochemical characterization and toxicological significance of P-450HFLb purified from human fetal livers.

Immunochemical properties of P-450HFLb purified from human fetal livers were investigated. P-450HFLb cross-reacted with antibodies to rat P-4501A1 but not with antibodies to CYP2A6, CYP2C9, CYP3A7 (P-450HFLa) and rat CYP2B1. In addition, P-450HFLb also cross-reacted with both monospecific antibodies to rat CYP1A1 and CYP1A2. However, P-450HFLb was shown to be an immunochemically distinct form of cytochrome P-450 from P-450PA (human CYP1A2). Immunoblot analysis of human fetal livers with the antibodies to P-450HFLb showed that P-450HFLb was expressed in all fetal livers studied although there appeared to be individual differences in the amounts of P-450HFLb expressed in fetal livers. The formation of mutagens from IQ (but not from AFB1) in fetal liver homogenates was inhibited by the antibodies to P-450HFLb in a dose dependent manner. These results suggest that P-450HFLb may be a form of human cytochrome P-450 classified into CYP1 gene family, and that the cytochrome P-450 is, in part, responsible for the mutagenic activation of IQ in human fetal livers as well as CYP3A7 (P-450HFLa).

Differential catalytic properties in metabolism of endogenous and exogenous substrates among CYP3A enzymes expressed in COS-7 cells.

The catalytic properties of CYP3A7 in the metabolism of endogenous and exogenous substrates were compared with those of CYP3A4 and CYP3A5 using COS-7 expressing enzymes. The highest activities of dehydroepiandrosterone (DHEA) and dehydroepiandrosterone 3-sulfate (DHEA-S) 16alpha-hydroxylase were observed in COS-7 cells expressing CYP3A7. In contrast, the activity of testosterone 6beta-hydroxylase of CYP3A7 expressed in COS-7 cells was much less than that of CYP3A4 expressed in COS-7 cells. The rate of carbamazepine 10, 11-epoxidation was the greatest in COS-7 cells expressing CYP3A4, followed by CYP3A5 and CYP3A7. On the other hand, the formation of reductive metabolite of zonisamide was the highest in COS-7 cells expressing CYP3A4, followed by CYP3A7 and CYP3A5. Furthermore, the addition of triazolam resulted in a decrease in 6beta-hydroxylation catalyzed by CYP3A7, but not by CYP3A4, whereas the pretreatment of microsomes with triacetyloleandomycin (TAO) resulted in a decrease in the reaction catalyzed by CYP3A4, but not by CYP3A7. Together with these results, it was suggested that CYP3A7 exerts differential catalytic properties not only in metabolism of endogenous substrates but also in drug metabolism compared to CYP3A4 and CYP3A5.

CYP1A1 is a major enzyme responsible for the metabolism of granisetron in human liver microsomes.

Granisetron, a potent 5-HT3 receptor antagonist, has been reported to be mainly metabolized to 7-hydroxygranisetron and a lesser extent to 9'-desmethylgranisetron in humans. A previous study indicated that cytochrome P450 (CYP)3A4 is a major catalyst of 9'-demethylation, although the major CYP isoform(s) responsible for 7-hydroxylation are unknown. To clarify granisetron 7-hydroxylase, the in vitro metabolism of granisetron using expressed human CYPs and human liver microsomes was investigated. 7-Hydroxygranisetron was produced almost exclusively by CYP1A1, while, apparently, 9'-desmethylgranisetron was preferentially produced by CYP3A4. Marked inter-individual differences in the ratio of the formation of 7-hydroxygranisetron and 9'-desmethylgranisetron in human liver microsomes was observed. Granisetron 7-hydroxylase activity was strongly correlated with benzo[a]pyrene 3-hydroxylase activity (p<0.0001), but not with testosterone 6beta-hydroxylase activity in human liver microsomes. Furthermore, an anti-human CYP1A1 antibody completely inhibited 7-hydroxylation in human liver microsomes, however, the reaction was not inhibited at all by an anti-CYP3A4 antibody. On the other hand, granisetron 9'-demethylase activity correlated significantly not only with testosterone 6beta-hydroxylase activity (p<0.0001) but also with benzo[a]pyrene 3-hydroxylase activity (p<0.01). Consistent with this, both the anti-CYP1A1 and anti-human CYP3A4 antibodies inhibited the 9'-demethylase activity. These data indicate that CYP1A1 is a major enzyme responsible for the metabolism of granisetron via a main 7-hydroxylation pathway and an alternative 9'-demethylation route. This is the first report demonstrating the substantial contribution of CYP1A1 to the metabolism of a drug, although its role in the metabolism of environmental compounds is well established.

Effects of sympathetic stimulation, with and without previous alpha 1 and beta adrenoceptor blockade, on refractoriness dispersion in canine heart.

OBJECTIVE: The aim was to determine the electrophysiological effects of cardiac sympathetic stimulation, with and without prior alpha 1 and beta adrenoceptor blockade during myocardial ischaemia in dogs. METHODS: Chloralose anaesthetised dogs were studied 2 h after ligation of the obtuse marginal branches of the circumflex artery (OMB). The refractory period was measured at eight sites in the ischaemic zone, two sites in the border zone, and two sites in the normal zone with S1-S2 extrastimulus methods. RESULTS: In group 1 (n = 13), before OMB ligation, stimulation of the ventrolateral cardiac nerve shortened the refractory period only in the ischaemic zone (p < 0.01). OMB ligation resulted in a significant shortening of the refractory period in the ischaemic zone (p < 0.01). In group 2 (n = 12), the alpha 1 blocker bunazosin (0.2 mg.kg-1, intravenously) blunted the shortening of the refractory period in the ischaemic zone induced by OMB ligation (p < 0.01), resulting in a reduction in refractory period dispersion between the ischaemic and non-ischaemic (border and normal) zones. Subsequent administration of the beta blocker propranolol (0.2 mg.kg-1, intravenously) prolonged refractory periods both in the ischaemic and in the non-ischaemic zones (p < 0.05 v p < 0.001). Ventrolateral cardiac nerve stimulation reversed the effects of bunazosin on the refractory period in the ischaemic zone; however, after the addition of propranolol, neural stimulation no longer influenced the refractory period. In group 3 (n = 13), propranolol (0.2 mg.kg-1, intravenously) reversed the shortening of the refractory period in the ischaemic zone (p < 0.01) induced by OMB ligation but also prolonged the refractory period in the non-ischaemic zone (p < 0.001); refractory period dispersion between the ischaemic and non-ischaemic zones was thus not reduced. Ventrolateral cardiac nerve stimulation had no effect on refractory period after administration of propranolol alone or propranolol followed by bunazosin. CONCLUSIONS: Although an alpha 1 blocker may be better than a beta blocker in reducing refractory period dispersion between the ischaemic and non-ischaemic myocardium, a beta blocker may protect more effectively than an alpha 1 blocker against the detrimental effects of cardiac nerve activity on electrical instability in the ischaemic myocardium.

Sex-related difference in oxidative metabolism of testosterone and erythromycin by hamster liver microsomes.

The activities of testosterone hydroxylases and erythromycin N-demethylase were significantly higher in liver microsomes from female hamsters than in the male counterparts. SDS-polyacrylamide gel electrophoresis revealed a difference in protein composition between male and female liver microsomes in the molecular mass region comprising cytochrome P-450. Western blot analysis showed further that antibodies to rat male-specific cytochrome P-450 crossreacted with at least two proteins in both male and female hamster microsomes, but one of the female proteins had a different molecular mass from that of the male proteins. It is concluded that sex difference in liver microsomal cytochrome P-450 is not restricted to rats and mice, as has previously been believed.

Histological and functional analysis of vascular smooth muscle cells in a novel culture system with honeycomb-like structure.

Vascular smooth muscle cells (SMCs) undergo phenotype change with the development of atherosclerosis. The phenotype changes of SMCs have been observed in various culture conditions, such as collagen-coated dishes. Here, we report the morphological and functional features of SMCs in a novel culture system using type I-collagen in a characteristic three-dimensional structure designated as honeycombs. The number of ribosome and mitochondria in SMCs cultured in honeycombs was one half or third of those cultured on collagen-coated plastic plates. DNA and protein synthesis of SMCs cultured in honeycombs were less than 1 and 30-40%, respectively, of those cultured on plastic plates. In addition, PDGF-BB did not increase the amount of DNA synthesis in SMCs in honeycombs. SMCs in honeycombs were shown to express several proteins, which are known to express in SMCs in medial layers of arteries. Particularly, caldesmon heavy chain was expressed in SMCs cultured in honeycombs, whereas not in those on plastic plates. Although focal adhesion kinase (FAK) was clearly detected in SMCs in honeycomb, the phosphotyrosine content of focal adhesion kin ase decreased in the process of culture. Immunoblot analysis showed dear different expression of ERK1 and ERK2 of mitogen-activated protein kinase in SMCs. SMCs in honeycombs expressed ERK2, more abundantly compared to ERK1, whereas SMCs in plates show the same levels of expressions for both proteins. Thus, the histological and functional feature of SMCs in the novel culture system is different from SMCs in plastic plates. The three-dimensional culture system described here may be indicating that cultured SMCs are able to express different proteins responding to the surrounding structures.