Acute acalculous cholecystitis following extended administration of nirmatrelvir/ritonavir for persistent SARS-CoV-2 infection

Immunocompromised patients with hematologic malignancies, particularly those treated with anti-CD20 antibodies such as rituximab and obinutuzumab, are known to be at risk of prolonged infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Prolonged administration or combination therapy with antiviral medications reportedly yields favorable outcomes in these patients. However, knowledge regarding the adverse events associated with such therapeutic approaches is limited. Herein, we report a case of acute acalculous cholecystitis (AAC) following extended administration of nirmatrelvir/ritonavir (NMV/r) in a 68-year-old Japanese man with persistent SARS-CoV-2 infection. The patient had received obinutuzumab and bendamustine for follicular lymphoma and was diagnosed with coronavirus disease 2019 (COVID-19) approximately one year after treatment initiation with these drugs. Subsequently, he was admitted to a different hospital, where he received antiviral drugs, monoclonal antibodies, and steroids. Despite these interventions, the patient relapsed and was subsequently transferred to our hospital due to persistent SARS-CoV-2 infection. Remdesivir administration was ineffective, leading to the initiation of extended NMV/r therapy. One week later, he exhibited elevated gamma-glutamyl transpeptidase (GGT) levels, and one month later, he developed AAC. Cholecystitis was successfully resolved via percutaneous transhepatic gallbladder drainage and administration of antibiotics. We speculate that extended NMV/r administration, in addition to COVID-19, may have contributed to the elevated GGT and AAC. During treatment of persistent SARS-CoV-2 infection with extended NMV/r therapy, patients should be carefully monitored for the appearance of findings suggestive of biliary stasis and the development of AAC.

Sputum Gram stain of hypervirulent Klebsiella pneumoniae

Hypervirulent Klebsiella pneumoniae has virulence genes relevant to capsule overproduction, which could lead to the finding of thick transparent area ("halo") in Gram stain. In sputum Gram stain, observation of a large Gram-negative rod with a thick capsule may not only indicate that it is K. pneumoniae but also that it is a highly virulent strain.

A266 DIET-BASED THERAPIES FOR INTESTINAL DYSFUNCTION INDUCED BY CLOSTRIDIOIDES DIFFICILE INFECTION

Background

Chronic gut dysfunction occurs in up to 25% of patients following antibiotic-treated C. difficile infection (CDI). We developed a humanized mouse model in which germ free mice colonized with microbiota from patients with severe constipation post-CDI developed slow colonic transit, as a result of damage to the Interstitial Cells of Cajal (ICC) network by pro-inflammatory macrophages. Colonic transit, immune activation and the ICC network normalized after fecal microbiota transplantation using samples from healthy mice, as well after treatment with psyllium fiber. Here we explored the long-term effects of psyllium and evaluated the therapeutic potential of pectin and quercetin in this model.

Purpose

1) To investigate the time course of the beneficial effect of psyllium on colonic motility.

2) To explore possible therapeutic properties of flavonoids and pectin.

Method

Germ-free mice were colonized with microbiota from the post-CDI (PCDI) patient or healthy controls (HC). After 3 weeks, the mice were fed for 4-5 weeks with a control diet or diets with 15% psyllium (PSY), 10% pectin (PCT) or 0.05% quercetin (QCT). To evaluate time course of PSY on motility, control diet was administered for 3-weeks following PSY treatment. The bead expulsion test was used to assess colonic motility. Stool samples were collected for microbial profiling, and short and branched-chain fatty acids (SCFA/BCFA) analysis. Macrophages morphology and counts, and ICC network structure were evaluated by immunohistochemistry.

Result(s)

Compared to HC microbiota, colonization with post-CDI microbiota induced slow colonic transit in recipient mice, and this was normalized by PSY (n=13; p=0.02). The benefit of PSY was transient as colonic transit slowed following discontinuation of PSY (p=0.001). The changes in colonic transit were paralleled by switch in macrophages phenotype and damage to the ICC network. Additionally, discontinuation of PSY resulted in a return of microbial diversity (p< 0.001), SCFA/BCFA levels (acetic and propionic acid/ iso-butyric and valeric acid) and specific bacterial species abundances, to values seen in untreated mice colonized with post-CDI microbiota. Microbial analysis predicted potential pathways involved in macrophage polarization, including the synthesis of SCFA/BCFA, degradation of inositol and production of acetylglucosamine.

PCT also normalized slow intestinal transit in mice colonized with post-CDI microbiota (p=0.003), restored phenotype of infiltrating macrophages, and improved the structural integrity of the ICC network. In contrast, QCT failed to improve gut dysfunction in PCDI mice.

Conclusion(s)

Our results suggest that the beneficial effects of psyllium in this model are transient. Dietary pectin, but not quercetin, may also serve as a novel treatment strategy to restore colonic motility and immune homeostasis in humans with severe constipation post-CDI.

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A62 IDENTIFICATION OF SPECIFIC COLONIC DEEP MUSCLE LAYER MACROPHAGES SUBSETS BY THE CD64 (FCΓRI) MARKER

Background

Although intestinal muscle layer macrophages have been suggested to play an important role in the colonic transit by interacting with the myenteric plexus neurons, they have not been fully characterized. CD64 (FcγRI) is one of the most generally used markers for intestinal macrophages, but several studies suggested existence of a subpopulation of macrophages that lack CD64. In addition, the muscle layer macrophage subsets currently identified are considered to be same in the small intestine and colon, although this has not been formally tested.

Purpose

In this study, we aim to identify and characterize the subsets of muscle layer macrophages by CD64 marker. We hypothesize that colon specific CD64-macrophages have a different role from CD64+ conventional macrophages.

Method

The muscle layers of small intestine (ileum) and colon were separated from SPF mice and cells from each muscle layer were analyzed by flow cytometry and fluorescent staining. The muscle layer macrophages were gated withCD45+, F4/80+, CD11b+ and Ly6c-, and analyzed with CD64 and MHCⅡmarkers by flow cytometry. In additional experiments, fluorescent staining with CD64 and F4/80 was assessed in whole-mount tissue of the separated muscle layer.

Result(s)

Within the macrophage population from the colon muscle layer, we found not only CD64+ cells, a conventional marker of macrophage, but also CD64- cell population (CD45+, F4/80+, CD11b+, Ly6c-). However, in the small intestine, this CD64- cell population was barely detectable. In addition, colonic CD64+ cells had mostly high expression of MHCⅡ marker, while CD64- cells had low expression of MHCⅡ. A similar pattern was found when we examined intestinal and colonic tissues by immunofluorescent staining.

Conclusion(s)

We identified a colon-specific CD64- subset of macrophage in muscle layer. Additional experiments are needed to characterize their immunomodulatory properties.

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CLIINICAL PRACTICE

Chorioamnionitis and early pregnancy loss caused by ampicillin-resistant non-typeable Haemophilus influenzae

Haemophilus influenzae can cause intra-amniotic infection and early pregnancy loss. The mode of transmission and risk factors for H. influenzae uterine cavity infections are unknown. Here, we present the case of chorioamnionitis caused by ampicillin-resistant H. influenzae in a 32-year-old Japanese woman at 16 weeks of gestation. Despite empirical treatment, including ampicillin, as recommended by the current guidelines, she had fetal loss. The antimicrobial regimen was changed to ceftriaxone, and the treatment was completed without complications. Although the prevalence and risk factors for chorioamnionitis caused by ampicillin-resistant H. influenzae are unknown, clinicians need to recognize H. influenzae as a potentially drug-resistant and lethal bacterium for pregnant women.

Isolation of Aspergillus udagawae in Canaliculitis: A Case Report

Aspergillus udagawae is a cryptic species of Aspergillus section Fumigati. Here, we report a case of canaliculitis with isolated A. udagawae. Fungal canaliculitis is a rare lacrimal disease, and its clinical features are poorly understood. The causative fungus was initially misclassified as Aspergillus thermomutatus by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) but was finally identified as A. udagawae by β-tubulin genetic analysis. The patient showed rapid improvement and did not experience relapse after drainage alone, without antifungal therapy. A. udagawae has low virulence, which may be related to the minimally invasive nature of the infection.

Factors associated with viral clearance periods from patients with COVID-19: A retrospective observational cohort study

INTRODUCTION

Knowledge is limited on the virologic course of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection, particularly the time taken for viral clearance and the optimal time to discontinue isolation. This study aims to identify the clinical and demographic factors influencing the time taken for viral clearance in patients with COVID-19 to determine the optimal isolation period.

METHODS

This two-center retrospective observational cohort study was conducted between March 1 and June 31, 2020. Patients with COVID-19, which was confirmed by real-time reverse transcription polymerase chain reaction, were included. Data were extracted from medical records. The positive duration, which was defined as the period from the day of symptom onset to the negative conversion day, was assessed using a generalized linear model.

RESULTS

We included 63 patients. The mean positive duration was 20 days. The positive duration was significantly shorter for patients younger than 30 years of age and those between 30 and 60 years of age than for patients older than 60 years of age. We observed a more scattered distribution of the positive duration in older patients than in younger patients.

CONCLUSIONS

Younger patients who recovered from COVID-19 took less time to clear SARS-CoV-2 than older patients; thus, a classification of the isolation periods based on age could be considered. A uniform viral clearance period for older patients may be difficult to determine because of biases such as underlying medical conditions. Further surveillance measures are recommended to determine the viral clearance time and the optimal isolation period.

A case of maternal varicella: Expected role of primary care physicians in confirming immune status for varicella in women at childbearing age

At 19-week gestation, a 32-year-old Japanese woman presented with a 3-day history of fever and vesicular rashes on the skin and was diagnosed with varicella, which resolved after antiviral therapy. In the primary clinic, her immunity to rubella and measles, but not to varicella, was confirmed at preconception counseling. Maternal varicella infection can cause congenital varicella syndrome characterized by congenital malformations and neurological deficits. This case recommends that all women of childbearing age should be assessed for immunity to varicella before pregnancy and that primary care physicians should take initiatives for preventing maternal varicella.

a-Si:H TFT Driven Linear Image Sensor

A new contact type linear image sensor, which has 8.5 inches in length and 300 dot/inch, has been developed. By using a thin film transistor (TFT) array as a switching device, it requires only one IC chip compared with 20 ICs in conventional sensor.

The new sensor integrates a-Si:H photodiode (PD) array, a-Si:H TFT array, multiplex circuits and an analog multiplexer on a single substrate. The TFT has an inverted staggered structure and amorphous silicon nitride (SiNx) is used as a gate insulator. The PD has a Cr/a-Si:H/ITQ sandwich structure and each PD is completely isolated by photolithography. In the multiplex circuits, a ground line is inserted between each signal line to reduce a capacitive coupling between them.

A new custom LSI has also been developed. It has 64-ch input terminals to detect small signal with amplification and 41-ch output terminals to control the gates of TFT array. The sensor with the new LSI has achieved 2MHz clock frequency operation and proved to be used as a high speed device.

Itinerant electron magnetism in CaRu(1-x)Mn(x)O(3) (0 ≤ x ≤ 0.5)

The effect of Mn substitution in paramagnetic metal CaRuO(3) was studied by magnetization and neutron diffraction measurements. Development of ferromagnetic order is observed for x≥0.2 in CaRu(1-x)Mn(x)O(3). For the sample with x = 0.4, the Curie temperature of ∼160 K is obtained from the Arrott plot and the ratio of effective moment and saturation moment P(eff)/M(0) is estimated to be ∼4.8. We further found that the magnetization is significantly suppressed with decreasing temperature T below ∼90 K. In the neutron diffraction experiment at T = 15 K, we observed the evolution of a magnetic Bragg peak originating from the G-type antiferromagnetic order as well as the ferromagnetic one. This strongly suggests that both ferromagnetic and antiferromagnetic states are coexistent with each other at low temperatures. In the M(T)(0)(2) against T(2) plot (here, M(T)(0) is a spontaneous magnetization estimated from the Arrott plot), M(T)(0)(2) linearly increases with decreasing T(2) in the ferromagnetic region between ∼90 and 160 K. The ferromagnetic properties of the CaRu(1-x)Mn(x)O(3) system (x≤0.5) are well explained in terms of spin fluctuation theory based on the itinerant electron model rather than the localized spin model.

A new behaviour of ac losses in superconducting Bi(2)Sr(2)CaCu(2)O(8) single crystals

A new ac loss behaviour is observed in the superconducting state of Bi(2)Sr(2)CaCu(2)O(8) single crystals using a novel technique of measuring dissipation at radio frequencies. It is found that the ac loss in the superconducting state is larger than that in the normal state. This counter-intuitive result is explained in terms of the cumulative effect of repetitive decoupling of intrinsic Josephson junctions in the crystals and analysed in the framework of Ambegaokar-Baratoff theory. The ac losses are studied as a function of temperature, rf amplitude and magnetic field applied at different orientations. A peak in ac losses is observed in the superconducting state along the temperature scale. The amplitude of the peak decreases and shifts towards lower temperature with increasing field and also when the field orientation with respect to the c axis of the crystal changes from the perpendicular to parallel direction. The origin of the peak and its behaviour are discussed in the context of coupling energy of Josephson junctions present in the sample. In the presence of a magnetic field another peak in ac losses arises at temperatures close to T(c), which is associated with the Lorentz-force-driven motion of vortices.

Gastric mucin phenotype defines tumour progression and prognosis of intrahepatic cholangiocarcinoma: gastric foveolar type is associated with aggressive tumour behaviour

AIMS

To identify the role of mucus core protein (MUC) in intrahepatic cholangiocarcinoma (ICC).

METHODS AND RESULTS

We examined the expression profile of MUC2, MUC5AC and MUC6 by immunohistochemical staining in 100 ICCs and compared the clinicopathological factors and the immunohistochemical results. The expression frequency was: MUC2, 9%; MUC5AC, 40%; and MUC6, 21%. According to the gastric mucin expression profile, ICCs were classified into the following groups: null type (n = 43), gastric foveolar type (n = 36), pyloric gland type (n = 11) and gastric combined type (n = 10). Half of the gastric foveolar type and the gastric combined type were located in the hilar region, but the other types were predominant at the periphery (P = 0.0004). Well-differentiated components were more often detected in the gastric combined type and the pyloric gland type (P = 0.0281). The gastric foveolar type was associated with a higher incidence of lymph node metastasis (P < 0.0001). The pyloric gland type was associated with better survival and the gastric foveolar type was associated with worse survival. The gastric mucin phenotype was an independent prognostic factor by multivariate survival analysis.

CONCLUSION

The gastric foveolar type of ICC was more often associated with aggressive tumour development, whereas the pyloric gland type exhibited less aggressive behaviour.

Ta 5d band symmetry of 1T-TaS1.2Se0.8 in the commensurate charge-density-wave phase

We present a detailed angle-resolved photoemission study on the layered transition-metal dichalcogenide 1T-TaS1.2Se0.8 in the commensurate charge-density-wave (CDW) phase. A drastic reduction in the spectral weight along the high symmetry line GammaM, particularly around the point M, is observed when s-polarized light was used. This implies that the initial state must be symmetric with respect to a mirror plane perpendicular to the line GammaK, which is consistent with conventional band calculations in the absence of the CDW. We conclude that there is only a limited amount of modification of the electronic structure of 1T-TaS1.2Se0.8 in the commensurate CDW phase due to the CDW-related potential.

A novel and simple type of liposome carrier for recombinant interleukin-2

The strong interaction between recombinant interleukin-2 (IL-2) and liposome was characterized and its possible application to drug-delivery control considered. The liposomes were prepared with egg phosphatidylcholine, distearoyl-phosphatidylglycerol (DSPG), dipalmitoyl-phosphatidylcholine, dipalmitoyl-phosphatidylglycerol or distearoyl-phosphatidylcholine (DSPC). Small and hydrophobic liposomes were selected, which were composed of saturated and long-fatty-acid-chain phospholipids. When the composition and the mixture ratio of IL-2 and the liposomewere optimized, morethan 95% ofthe lyophilized IL-2 (Imunace, 350000 JRU) was adsorbed consistently onto the DSPC-DSPG liposome (molar ratio, 10:1; 25 micromol mL(-1); 30 nm in size). Merely mixing IL-2 lyophilized with liposome suspension is convenient pharmaceutically. After intravenous administration to mice, liposomal IL-2 was eliminated half as slowly from the systemic circulation as free IL-2, with more than 13 and 18 times more IL-2 being delivered to the liver and spleen, respectively. After subcutaneous administration of liposomal IL-2 to mice, the mean residence time of IL-2 in the systemic circulation was 8 times that of free IL-2. These results show that IL-2 consistently adsorbs onto the surface of liposomes after optimization of its composition and mixing ratio. Intravenous and subcutaneous administration to mice demonstrates the gradual release of IL-2. Further trials are warranted using these liposomes.

FR198248, a new anti-influenza agent isolated from Apsergillus terreus No 13830. I. Taxomony, fermentation, isolation, physico-chemical properties and biological activities

A novel anti-influenza agent, FR198248, was isolated from the cultured broth of a fungal strain No.13830. The strain was identified as Aspergillus terreus from morphological characteristics. FR198248, a new type of hydroxyl benzaldehyde compound, showed antiinfluenza virus activity in Madin-Darby canine kidney (MDCK) cells in vitro. The mode of action of FR198248 against influenza virus A could be ascribed to an inhibitory effect on the stage of virus adsorption. Furthermore, FR198248 possessed potent in vivo anti-influenza activity in a murine model of respiratory tract infection.

New Anti-influenza Agents, FR198248 and Its Derivatives. II. Characterization of FR198248, Its Related Compounds and Some Derivatives

We isolated FR198248 from the cultured broth of Aspergillus terreus No. 13830 as a new anti-influenza agents. The structure of FR198248 was elucidated by several spectroscopic experiments as a novel tetrahydroxybenzaldehyde compound. Furthermore, we described the characteristics of FR198248, its related compounds and some derivatives.

FR191512, a novel anti-influenza agent isolated from a fungus strain No.17415. I. Taxonomy, fermentation, isolation, physico-chemical properties and structure elucidation

In the course of our screening for anti-influenza agents of microbial origin, FR191512 was isolated from the cultured broth of fungus strain No. 17415 as colorless powder. The structure of FR191512 was determined by several spectroscopic experiments as a novel polyphenolic compound. This compound showed potent antiviral activity against influenza A virus.

FR191512, a novel anti-influenza agent isolated from a fungus strain No.17415. II. Biological properties

FR191512, a novel polyphenolic compound, inhibited the infectivity of influenza A virus in Madin-Darby canine kidney (MDCK) cells in vitro. Furthermore, FR191512 showed good in vivo anti-influenza activity in a mouse model of intranasal infection with influenza A virus. The cytotoxic activity of FR191512 against MDCK cells was very weak.

Non-Sonogashira-type palladium-catalyzed coupling reactions of terminal alkynes assisted by silver(I) oxide or tetrabutylammonium fluoride

Palladium-catalyzed reaction of aryl and alkenyl halides with terminal alkynes in the presence of silver(I) oxide as an activator furnishes various arylated or alkenylated alkynes in good to excellent yields. The similar coupling reaction is also found to proceed using tetrabutylammonium fluoride (TBAF) or tetrabutylammonium hydroxide (TBAOH) as an activator.

Antioxidants from Lespedeza homoloba. (I)

The stems of Lespedeza homoloba yielded eight new and three known phenolic compounds. Their structures have been elucidated on the basis of their spectral data. These compounds had strong antioxidative activity against lipid peroxidation in the rat brain homogenate test. 3,9-Dihydroxypterocarp-6a-en and lespedezol A2 showed significant antiallergic activity in allergic (type I) mice.

Determination of the entrapped volume of liposomes: dilution method

A novel method was developed for the determination of the entrapped volume of liposomes. The obtained values of the entrapped volume by our "dilution method" agreed very well with those of the conventional "quenching method." The dilution method also offered the great advantages of simple procedure and high reproducibility. The principle and validity of our method are discussed.

Compositional Homogeneity of Liposomal Membranes Investigated by Capillary Electrophoresis

Capillary electrophoresis has been demonstrated to be a new powerful tool for investigating the compositional homogeneity of liposomal membranes composed of phospholipids and guest molecules. In the case of charged components distributed heterogeneously on membranes, electropherograms show several distinguishable peaks even with monodisperse size distributions of liposomes because each liposomal particle carries a different amount of charge. The heterogeneity of noncharged components, when the lipids and the guest components have significantly different molar absorptivities at two different wavelengths, can also be judged from the signal ratio observed at the two wavelengths using a photodiode array detector. This new method can be used for the quality control of liposomal products. Copyright 1998 Academic Press.

Alveolar bone loss in rats infected with a strain of Prevotella intermedia and Fusobacterium nucleatum isolated from a child with prepubertal periodontitis

Prevotella intermedia and fusobacterium nucleatum are associated with various forms of periodontal disease. The purpose of the present study was to infect the clinical isolates of these periodontopathic bacteria and to induce a significant loss of alveolar bone in specific pathogen-free (SPF) rats in the absence of ligatures. P. intermedia YKD8 and F. nucleatum YKZ5 were isolated from a prepubertal periodontitis patient, while P. gingivalis MWB13 was from a patient with juvenile periodontitis. At first, SPF Sprague-Dawley rats (70 days of age, male) were infected with A. viscosus Ny1R and subsequently superinfected with P. gingivalis MWB13, P. intermedia YKD8, or F. nucleatum YKZ5, respectively. The control group was infected with A. viscosus Ny1R alone. All rats were killed and periodontal bone levels were assessed morphometrically 135 days after the first infection with A. viscosus. P. intermedia YKD8 was recovered frequently from rats, with serum antibody levels remaining highly elevated throughout the experiment. Significant loss of alveolar bone was found in rats infected with P. intermedia YKD8, the virulence of which was equivalent to that of P. gingivalis MWB13. F. nucleatum YKZ5 also induced alveolar bone loss, but not significantly when compared with rats infected with A. viscosus Ny1R alone.

Influence of ego strength on associations of alexithymia and depression

This study examined the association of scores for ego strength with the scores on a measure of alexithymia and with depressive symptoms in two samples of 260 college students and 92 psychiatric outpatients. In both samples, scores on alexithymia were significantly correlated with those for depressive symptoms; however, correlations became nonsignificant when scores for ego strength were controlled for. The results suggest that the association between alexithymia scores and depressive symptoms is decreased by lower scores for ego strength.

An investigation of the psychometric properties of the 26 item Toronto Alexithymia Scale in a Japanese culture

We investigated the psychometric properties of the Japanese version of the 26 item Toronto Alexithymia Scale in a Japanese culture, testing a sample of 1,008. The validity and reliability of this Japanese version were suggested by significant correlations with the Beth Israel Hospital Psychosomatic Questionnaire and estimates to test-retest and internal consistency. These results suggest that this version may be suitable for Japanese populations. Although alexithymia scores were correlated negatively with increasing age, the result, based on the large sample, seems to be of minimal significance.

FR901724, a novel anti-human immunodeficiency virus (HIV) peptide produced by Streptomyces, shows synergistic antiviral activities with HIV protease inhibitor and 2',3'-dideoxynucleosides

A novel tricyclic 21-amino-acid peptide, FR901724, was isolated from the cultured broth of Streptomyces sp. No. 73264. This peptide appears to possess potent anti-human immunodeficiency virus (HIV) activity in vitro and might represent a lead to a new class of anti-HIV agents; it qualifies as an HIV-cell fusion inhibitor because of its weak inhibition of virus-cell binding and strong inhibition of syncytium formation. From the time-of-addition experiments, the mode of action of FR901724 was found to definitely differ from that of KNI-272, a peptide mimetic allophenylnorstatine-derivative HIV protease inhibitor. FR901724 appears to interact with a stage of the virus replicative cycle that may well correspond to virus-cell fusion. We also found that FR901724 was synergistic or had a strong tendency toward synergism when combined with other antiviral drugs, such as KNI-272, AZT, ddI and dextran sulfate.

The alkaline phosphatase in human plexus chorioideus

The content of alkaline phosphatase isozymes in various brain regions was determined by monoclonal immunocatalytic assays. The levels of the isozymes in human brain tissues were low compared with those in other human tissues, liver, kidney, bone, intestine and placenta. Plexus chorioideus in the brain, however, was found to express significant amounts of alkaline phosphatase activity. The purified isozyme from human plexus chorioideus demonstrated a single 70 kDa protein band on SDS-polyacrylamide gel which coincides with that of tissue-unspecific alkaline phosphatase from human liver. The isozyme expressed in the plexus was confirmed to be the tissue-unspecific alkaline phosphatase isozyme with regard to its reactivity with monoclonal antibodies specific for liver alkaline phosphatase, heat stability, and the inhibition by amino acids. This finding adds new dimensions to the functional role this isozyme may play.

O/W lipid emulsions for parenteral drug delivery. I. Pharmacokinetics of the oil particles and incorporated sudan II

The potential usefulness of oil in water (O/W) lipid emulsions as parenteral drug delivery system for lipophilic drugs was examined in tumor-bearing rats. A model lipophilic drug, sudan II (PCoct = 226000), was formulated in five lipid emulsions consisting of soybean oil and various surfactants. Compared with HCO-60 micellar and plasma solutions of sudan II, the blood concentration of sudan II was markedly elevated by administration as a lipid emulsion. However, the distribution of sudan II to the liver, lungs, spleen, and adipose tissue was not altered, and that to the brain, heart, kidneys, muscle, and tumor was slightly decreased. To understand these results, pharmacokinetic analysis was performed using a newly derived compartmental model, and moreover, the organ distribution clearance was analyzed. It was suggested that the oil particles deliver the incorporated drug selectively to the liver, lungs, and spleen, and the speed of delivery could be surpressed by using HCO-60. However, in the case of sudan II, its rapid release from the oil particles after i.v. injection prevented a drastic alteration in the distribution of sudan II. The simulation studies suggested that a considerable decrease in the release rate or an increase in partition coefficient (experimentally more than 10(8) would be required for delivery.

In vitro and in vivo antibacterial activities of FK037, a new parenteral cephalosporin

In vitro and in vivo antibacterial activities of FK037, a new parenteral cephalosporin, were compared with those of cefpirome, ceftazidime and flomoxef. The advantages of in vitro activity of FK037 were as follows: (1) a broad-spectrum antibacterial activity, (2) the most potent activity (MIC90: 25 micrograms/ml) of the cephalosporins tested against highly methicillin-resistant Staphylococcus aureus (H-MRSA), (3) a strong activity against Enterobacter spp. and Citrobacter freundii resistant to the third-generation cephalosporins tested. The MICs of FK037 for 90% of the clinical isolates tested (MIC90s) were 0.012 microgram/ml for Streptococcus pyogenes, 0.05 microgram/ml for Escherichia coli, 0.1 microgram/ml for Streptococcus pneumoniae, 0.2 microgram/ml for Haemophilus influenzae and Proteus mirabilis, 0.39 microgram/ml for Klebsiella pneumoniae, 1.56 micrograms/ml for methicillin-sensitive S. aureus, Proteus vulgaris and Enterobacter aerogenes, 3.13 micrograms/ml for Staphylococcus epidermidis and Moraxella catarrhalis, 6.25 micrograms/ml for C. freundii, 12.5 micrograms/ml for low-level methicillin-resistant S. aureus (L-MRSA), Enterobacter cloacae and Pseudomonas aeruginosa, and 25 micrograms/ml for H-MRSA and Serratia marcescens. FK037 was similar in potency to cefpirome against strains except MRSA, and was superior to ceftazidime and flomoxef against strains except P. vulgaris and/or M. catarrhalis. The increase in MICs of FK037 against 2 L-MRSA strains (2- or 4-fold) was smaller than that of cefpirome and flomoxef (16- to 64-fold) after the third serial culture in the presence of each drug. FK037 was highly bactericidal against S. aureus, E. coli, K. pneumoniae and P. aeruginosa at the MIC or higher. FK037 had a potent protective activity against murine experimental systemic infections due to a wide variety of bacteria. Its protective activity was the strongest among the cephalosporins tested against H-MRSA and Acinetobacter calcoaceticus. Against the other strains, FK037 was as effective as cefpirome and similar or superior to flomoxef and ceftazidime though it was inferior to ceftazidime against P. aeruginosa. Transmission electron microscopic studies revealed that FK037 inhibited septum formation and induced thick cross walls and bacteriolysis at the division sites in MRSA after 4 h incubation.

Differences in the effects of two hexachlorobiphenyls on superoxide generation by polymorphonuclear leucocytes stimulated by N-formyl-methionyl-leucyl-phenylalanine and phorbol myristate acetate

The effects of hexachlorobiphenyls (HCBs) on superoxide (O2-) generation by guinea pig polymorphonuclear leucocytes were examined. 2,3,6,2',3',6'-HCB by itself had only a weak inductive effect on O2- generation. This compound, however, enhanced O2- generation stimulated by N-formyl-methionyl-leucyl-phenylalanine (FMLP) about twofold, but not the generation induced by phorbol myristate acetate (PMA). On the other hand, 3,4,5,3',4',5'-HCB suppressed O2- generation stimulated by both FMLP and PMA. The inhibitory potency of this compound was far greater with PMA (ID50, 5 microM) than with FMLP (ID50, 40 microM).