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Lundgren B, Thyssen JP, Johansen IS, Lillebaek T. [Resistant tuberculosis in Europe]. Ugeskr Laeger 2001; 163:5641-3. [PMID: 11665463] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/22/2023]
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Taipalensuu J, Törnblom H, Lindberg G, Einarsson C, Sjöqvist F, Melhus H, Garberg P, Sjöström B, Lundgren B, Artursson P. Correlation of gene expression of ten drug efflux proteins of the ATP-binding cassette transporter family in normal human jejunum and in human intestinal epithelial Caco-2 cell monolayers. J Pharmacol Exp Ther 2001; 299:164-70. [PMID: 11561076] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/21/2023] Open
Abstract
This investigation describes the expression and interindividual variability in transcript levels of multiple drug efflux systems in the human jejunum and compares the expression profiles in these cells with that of the commonly used Caco-2 cell drug absorption model. Transcript levels of ten-drug efflux proteins of the ATP-binding cassette (ABC) transporter family [MDR1, MDR3, ABCB5, MRP1-6, and breast cancer resistance protein (BCRP)], lung resistance-related protein (LRP), and CYP3A4 were determined using quantitative polymerase chain reaction in jejunal biopsies from 13 healthy human subjects and in Caco-2 cells. All genes except ABCB5 were expressed, and transcript levels varied between individuals only by a factor of 2 to 3. Surprisingly, BCRP and MRP2 transcripts were more abundant in jejunum than MDR1 transcripts. Jejunal transcript levels of the different ABC transporters spanned a range of three log units with the rank order: BCRP approximately MRP2 > MDR1 approximately MRP3 approximately MRP6 approximately MRP5 approximately MRP1 > MRP4 > MDR3. Furthermore, transcript levels of 9 of 10 ABC transporters correlated well between jejunum and Caco-2 cells (r2 = 0.90). However, BCRP exhibited a 100-fold lower transcript level in Caco-2 cells compared with jejunum. Thus, the expression of a number of efflux protein transcripts in jejunum are equal to, or even higher than, that of MDR1, suggesting that the roles of these proteins (in particular BCRP and MRP2) in intestinal drug efflux have been underestimated. Also, we tentatively conclude that the Caco-2 cell line is a useful model of jejunal drug efflux, if the low expression of BCRP is taken into account.
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Helweg-Larsen J, Lundgren B, Lundgren JD. Heterogeneity and compartmentalization of Pneumocystis carinii f. sp. hominis genotypes in autopsy lungs. J Clin Microbiol 2001; 39:3789-92. [PMID: 11574620 PMCID: PMC88436 DOI: 10.1128/jcm.39.10.3789-3792.2001] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
The extent and importance of genotype heterogeneity of Pneumocystis carinii f. sp. hominis within lungs have not previously been investigated. Two hundred forty PCR clones obtained from respiratory specimens and lung segments from three patients with fatal P. carinii pneumonia were investigated to detect genetic diversity in the internal transcribed spacer (ITS) region of the nuclear rRNA operon, the mitochondrial large-subunit (mtLSU) rRNA gene, and the dihydropteroate synthase-encoding gene. For two of the three examined patients, a mixture of different mtLSU rRNA and ITS genotypes was observed. Not all genotypes present in the lungs at autopsy were detected in the diagnostic respiratory samples. Compartmentalization of specific ITS and mtLSU rRNA sequence types was observed in different lung segments. In conclusion, the interpretation of genotype data and in particular ITS sequence types in the assessment of epidemiological questions should be cautious since genotyping done on respiratory samples cannot a priori be assumed to represent all genotypes present within the lung.
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Matos O, Costa MC, Lundgren B, Caldeira L, Aguiar P, Antunes F. Effect of oral washes on the diagnosis of Pneumocystis carinii pneumonia with a low parasite burden and on detection of organisms in subclinical infections. Eur J Clin Microbiol Infect Dis 2001; 20:573-5. [PMID: 11681438 DOI: 10.1007/s100960100563] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
This study was designed to assess the efficacy of using oral washes (OWs) to diagnose Pneumocystis carinii pneumonia (PCP) in patients with a low parasite burden and to detect cases of subclinical infection. A total of 104 paired induced sputum (IS) samples and OWs from 104 HIV-seropositive patients and 32 OWs from immunocompetent healthy controls were studied. All of the control samples were negative. Fifty-two IS specimens were positive for Pneumocystis carinii, and 26 of these cases were also detected in the OWs using conventional stain or polymerase chain reaction. Twenty-four of the PCP cases had a high or a moderate parasite load and 28 had a low parasite load; among them, Pneumocystis carinii was detected in the OWs of 15 and 11 cases, respectively. Fifteen of the 104 IS samples studied belonged to patients who were asymptomatic carriers or who had a subclinical infection, and Pneumocystis carinii was detected in the OWs of 4 of these cases. The parasite was not detected in 37 IS samples and in 74 OWs. The results of this study indicate that in patients with a low pulmonary parasite burden, the number of organisms reaching the oral cavity is insufficient for reliable detection in OWs. Thus, OWs are less useful than IS samples for detecting Pneumocystis carinii in cases of pneumonia in which a low parasite burden and/or subclinical infection are present.
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Lundvall A, Kugelberg U, Lundgren B, vd Mooren M, Zetterström C. Intraocular lens designed for the newborn infant eye. J Cataract Refract Surg 2001; 27:928-33. [PMID: 11408143 DOI: 10.1016/s0886-3350(00)00876-2] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
PURPOSE To evaluate the effects of an intraocular lens (IOL) designed for small eyes after clear lens extraction in an animal model. SETTING St. Erik's Eye Hospital, Karolinska Institute, Stockholm, Sweden. METHODS Clear lens extraction was performed in both eyes in 19 3-week-old rabbits. In 1 randomly selected eye of each rabbit, a small IOL with long haptics was implanted. Axial length, corneal thickness, corneal diameter, and intraocular pressure were measured preoperatively and every month for 6 months postoperatively. Six months after surgery, the wet mass of the after-cataract was determined. RESULTS The IOL remained well centered in all eyes. Four animals developed severe glaucoma in 5 eyes (3 aphakic and 2 pseudophakic) soon after surgery and were excluded. In the 15 animals completing the study, signs of glaucoma evolved in 7 animals (5 aphakic and 4 pseudophakic eyes). In aphakic eyes, significant amounts of after-cataract (median 250 mg) developed in all 15 surviving animals. In pseudophakic eyes, small amounts of after-cataract (median 30 mg) were present. During the first 2 months after surgery, ocular growth was less in pseudophakic eyes than in aphakic eyes. CONCLUSIONS Results indicate that implantation of a down-sized IOL with long haptics in small eyes is safe. Considerable less after-cataract was found in eyes with the IOL than in aphakic control eyes.
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Arendrup M, Lundgren B, Jensen IM, Hansen BS, Frimodt-Møller N. Comparison of Etest and a tablet diffusion test with the NCCLS broth microdilution method for fluconazole and amphotericin B susceptibility testing of Candida isolates. J Antimicrob Chemother 2001; 47:521-6. [PMID: 11328761 DOI: 10.1093/jac/47.5.521] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Three methods were compared for the susceptibility testing of yeast isolates to fluconazole and amphotericin B: two fagar diffusion methods (Etest and a tablet diffusion test) and the National Committee for Clinical Laboratory Standards (NCCLS) broth microdilution method. Given as MIC(50)s (range), fluconazole endpoints were: for the 24 h broth microdilution test, 0.25 mg/L (0.06-32 mg/L); for the Etest, 0.38 mg/L (0.064-24 mg/L); and for the NCCLS broth microdilution test, 2 mg/L (0.06->or=64 mg/L). With breakpoints of <3 mg/L for susceptible and >16 mg/L for resistant, the Etest and the 24 h microdilution test classified the isolates in agreement with the classification obtained by the NCCLS method. Results obtained by Etest were in closer NCCLS method than those obtained with the tablet test. Amphotericin B endpoints were lower for the 24 h microdilution and Etests than MICs obtained by the NCCLS broth microdilution method. Reproducibility was high for all tests; however, disadvantages of both diffusion tests were microcolonies in the inhibition zone and dependence on stringent standardization of inoculum.
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Helweg-Larsen J, Eugen-Olsen J, Lundgren B. Rapid detection of dihydropteroate polymorphism in AIDS-related Pneumocystis carinii pneumonia by restriction fragment length polymorphism. SCANDINAVIAN JOURNAL OF INFECTIOUS DISEASES 2001; 32:481-3. [PMID: 11055650 DOI: 10.1080/003655400458730] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/16/2022]
Abstract
Sulpha agents, which act by inhibiting the enzyme dihydropteroate synthase (DHPS), are used widely for the treatment and prophylaxis of Pneumocystis carinii pneumonia (PCP). Recently, we have shown that mutations in the dihydropteroate synthase (DHPS) gene of Pneumocystis carinii f.sp hominis are associated with failure of sulpha prophylaxis and increased mortality in HIV-1 positive patients with PCP, suggesting that DHPS mutations may cause sulpha resistance. To facilitate detection of DHPS mutations we developed a restriction fragment length polymorphism (RFLP) assay, detecting mutations at codon 55 and 57 of the P. carinii DHPS gene. The RFLP-assay was compared with direct DNA sequencing on 27 PCP isolates from HIV-1 positive patients with a mixture of wildtype and mutant DHPS types. In all samples the RFLP-assay correctly identified wildtype or DHPS mutation at codon 55 or 57. Combined with DNA extraction by a Chelex-based method, this method can be performed within 1 d and allows a fast, cost-efficient and reliable method of detection of DHPS mutations in P. carinii.
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Helweg-Larsen J, Lee CH, Jin S, Hsueh JY, Benfield TL, Hansen J, Lundgren JD, Lundgren B. Clinical correlation of variations in the internal transcribed spacer regions of rRNA genes in Pneumocystis carinii f.sp. hominis. AIDS 2001; 15:451-9. [PMID: 11242141 DOI: 10.1097/00002030-200103090-00003] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
OBJECTIVES To analyse the importance of sequence variations in the internal transcribed spacer (ITS) regions 1 and 2 of the nuclear rRNA operon in AIDS patients with Pneumocystis carinii pneumonia (PCP). DESIGN AND METHODS ITS 1 and 2 genotypes were determined in 162 bronchoalveolar lavage samples from 130 patients participating in a prospective cohort study of PCP. RESULTS A total of 49 different ITS genotypes were detected. ITS genotype was not associated with the clinical severity or outcome of PCP. In 37 of 162 (23%) samples infection with two or more genotypes was observed. A genotype switch was detected in six of 10 patients (60%) with recurrent episodes of PCP. However, genotype changes were also seen in 10 of 19 patients (53%) who had repeated bronchoscopies within the same episode of PCP. The same ITS type was observed twice in 13 (46%) of the 28 patients with repeat bronchoscopies during single or recurrent episodes of pneumonia, but in only 14 of 81 (17%) randomly selected pairs (P < 0.01). CONCLUSION Although the detection of ITS genotypes is not a random event, changes in genotype can be detected in a single episode of disease, with 23% of PCP patients being infected with more than one P. carinii genotype, thus complicating the use of this locus as a genetic marker to separate new infection from the reactivation of latent infection. ITS genotypes are not associated with the clinical severity of PCP.
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Christensen JJ, Friis HM, Heltberg O, Jarløv JO, Jensen KT, Højbjerg T, Kjaeldgaard P, Lundgren B, Mortensen N, Møller JK, Schouenborg P, Schrøder SS, Søgaard P, Kolmos HJ, Schønheyder HC. [Support to Danish antibiotic policy]. Ugeskr Laeger 2001; 163:1135. [PMID: 11242680] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/19/2023]
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Helweg-Larsen J, Lundgren B. [Diagnosis. Pneumocystis carinii]. Ugeskr Laeger 2001; 163:477-8. [PMID: 11218793] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/16/2023]
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Johansen HK, Jensen TG, Dessau RB, Lundgren B, Frimodt-Moller N. Antagonism between penicillin and erythromycin against Streptococcus pneumoniae in vitro and in vivo. J Antimicrob Chemother 2000; 46:973-80. [PMID: 11102417 DOI: 10.1093/jac/46.6.973] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
The combination of beta-lactam antibiotics and macrolides is often recommended for the initial empirical treatment of acute pneumonia in order to obtain activity against the most important pathogens. Theoretically, this combination may be inexpedient, as the bacteriostatic agent may antagonize the effect of the bactericidal agent. In this study, the possible interaction between penicillin and erythromycin was investigated in vitro and in vivo against four clinical isolates of Streptococcus pneumoniae with MICs of penicillin ranging from 0.016 to 0.5 mg/L and of erythromycin from 0. 25 to >128 mg/L. In vitro time-kill curves were generated with clinically relevant concentrations of penicillin (10 mg/L) and erythromycin (1 mg/L), either individually or in combination. Antagonism between penicillin and erythromycin was observed for the four isolates. In vivo interaction was investigated in the mouse peritonitis model. After intraperitoneal inoculation, penicillin and erythromycin were given either individually or in combination. For two of the four isolates, mortality was significantly higher in the groups treated with the combination of penicillin and erythromycin than in the groups treated with penicillin alone [32/36 (86%) vs. 3/12 (25%), P<0.05; and 24/36 (67%) vs. 3/12 (25%), P<0.05, respectively]. Using the mouse peritonitis model, in vivo time-kill curves showed that there was antagonism between erythromycin and penicillin for the examined isolate. The antagonism demonstrated in vitro and in vivo between penicillin and erythromycin suggests that ss-lactam antibiotics and macrolides should not be administered together unless pneumococcal infection is ruled out.
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Wallentin N, Lundgren B, Lundberg C. Lack of correlation between intraocular inflammation and after-cataract formation in the rabbit eye. J Cataract Refract Surg 2000; 26:1389-97. [PMID: 11020625 DOI: 10.1016/s0886-3350(00)00307-2] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
PURPOSE To determine whether an increased or reduced inflammatory response following cataract surgery influences the development of after-cataract. SETTING Department of Preclinical Ophthalmology, Pharmacia, Uppsala, Sweden. METHODS Rabbits that had had cataract surgery were given endotoxin, ovalbumin, dexamethasone, or diclofenac. Aqueous humor, leukocytes, and prostaglandin E(2) (PGE(2)) were analyzed, and the wet weight of the after-cataract was determined. RESULTS The wet weight of the after-cataract was unaffected by endotoxin and 67% lower in the eyes treated with ovalbumin than in the control eyes on day 56. Aqueous humor concentrations of leukocytes and PGE(2) were 94% and 87% lower in the group treated with dexamethasone than in the control group on day 7, and the concentration of PGE(2) was 98% lower in the diclofenac group; however, the wet weight of the after-cataract was unaffected by both treatments. CONCLUSION This study suggests that an increased inflammatory response does not increase the development of after-cataract and a reduction in the inflammatory response does not reduce the development of after-cataract.
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Kugelberg U, Lundvall A, Lundgren B, Holmén JB, Zetterström C. After-cataract and secondary glaucoma in the aphakic infant rabbit. J Cataract Refract Surg 2000; 26:1398-402. [PMID: 11020626 DOI: 10.1016/s0886-3350(00)00408-9] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
PURPOSE To study the association between after-cataract and secondary glaucoma after lensectomy and 5-fluorouracil treatment in an experimental infant rabbit model. SETTING St Erik Eye Hospital, Karolinska Institute, Stockholm, Sweden. METHODS Lensectomy was performed in both eyes of 16 3-week-old rabbits. One randomly selected eye in each rabbit was injected with 2.5 mg of 5-fluorouracil (5-FU) at surgery and 5.0 mg the day after surgery to reduce the formation of after-cataract. Axial length, corneal thickness, corneal diameter, and intraocular pressure were measured preoperatively and 4 times during the 6 months following surgery. Six months after surgery, the wet weight of the after-cataract was determined. RESULTS In 16 aphakic eyes treated with 5-FU, no or a minimal amount (<0.001 g) of after-cataract developed. None of the eyes showed signs of secondary glaucoma. Of 16 aphakic eyes not treated with 5-FU, 10 developed considerable amounts of after-cataract (>0.10 g); 8 of these developed glaucoma. The other 6 eyes had no or minimal after-cataract and did not develop secondary glaucoma. The relationship between after-cataract and secondary glaucoma was statistically significant. CONCLUSION A significant relationship between the amount of after-cataract and the development of secondary glaucoma was found in aphakic infant rabbit eyes.
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Törngren L, Lundgren B, Madsen K. Intraocular pressure development in the rabbit eye after aqueous exchange with ophthalmic viscosurgical devices. J Cataract Refract Surg 2000; 26:1247-52. [PMID: 11008057 DOI: 10.1016/s0886-3350(00)00407-7] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
PURPOSE To evaluate an animal model used to study intraocular pressure (IOP) development after aqueous exchange with several commercially available ophthalmic viscosurgical devices (OVDs). SETTING Department of Preclinical Ophthalmology, Pharmacia & Upjohn, Uppsala, Sweden. METHODS Albino rabbits (New Zealand White) were used. Aqueous humor (50 microL) was exchanged with 8 OVDs. The IOP was measured every second hour for 12 hours and then 24, 48, and 72 hours after aqueous exchange using a pneumotonometer (Modular One, Bio-Rad Digilab Inc). A minimum of 7 eyes was used for each OVD. Healon was used as control in 1 eye in all experiments. The OVDs were Viscoat (chondroitin sulfate-sodium hyaluronate), Provisc (sodium hyaluronate), Biolon (sodium hyaluronate), Healon GV, Healon5, Ophthalin (sodium hyaluronate), Ocucoat (hydroxypropyl methylcellulose), and Ivisc (sodium hyaluronate). RESULTS All OVDs caused a postoperative increase in IOP. At 24 hours, the IOP was at the preoperative levels. However, there was considerable variation in the maximum IOP value and when this value occurred. The maximum value appeared to depend on the concentration of the rheologically active substance in the product and the time of the average molecular mass. There was also an increase in central corneal thickness, with a maximum increase 24 hours after the exchange but a large variation among animals. CONCLUSION The animal model appears to be useful for comparing various OVDs, and the results may serve as a guide for the design of clinical studies of new products.
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Andersen AB, Jarløv JO, Kok-Jensen A, Lillebaek T, Lundgren B, Rosdahl N, Smith E, Viskum K. [Control of tuberculosis in Denmark]. Ugeskr Laeger 2000; 162:2343. [PMID: 10827567] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/16/2023]
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Matos O, Lundgren B, Caldeira L, Mansinho K, Aguiar P, Forte M, Antunes F. Evaluation of two nested polymerase chain reactions for diagnosis of Pneumocystis carinii pneumonia in immunocompromised patients. Clin Microbiol Infect 2000; 6:149-51. [PMID: 11168092 DOI: 10.1046/j.1469-0691.2000.00034-2.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Kaneshiro ES, Amit Z, Chandra J, Baughman RP, Contini C, Lundgren B. Sterols of Pneumocystis carinii hominis organisms isolated from human lungs. CLINICAL AND DIAGNOSTIC LABORATORY IMMUNOLOGY 1999; 6:970-6. [PMID: 10548595 PMCID: PMC95807 DOI: 10.1128/cdli.6.6.970-976.1999] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
The opportunistic pathogen Pneumocystis carinii causes pneumonia (P. carinii pneumonia, or PCP) in immunocompromised individuals such as AIDS patients. Rat-derived P. carinii carinii organisms have distinct sterols which are not synthesized by mammals and not found in other microbes infecting mammalian lungs. The dominant sterol present in the organism is cholesterol (which is believed to be scavenged from the host), but other sterols in P. carinii carinii have an alkyl group at C-24 of the sterol side chain (C(28) and C(29) 24-alkylsterols) and a double bond at C-7 of the nucleus. Recently, pneumocysterol (C(32)), which is essentially lanosterol with a C-24 ethylidene group, was detected in lipids extracted from a formalin-fixed human P. carinii-infected lung, and its structures were elucidated by gas-liquid chromatography, mass spectrometry, and nuclear magnetic resonance spectrometry in conjunction with analyses of chemically synthesized authentic standards. The sterol composition of isolated P. carinii hominis organisms has yet to be reported. If P. carinii from animal models is to be used for identifying potential drug targets and for developing chemotherapeutic approaches to clear human infections, it is important to determine whether the 24-alkylsterols of organisms found in rats are also present in organisms in humans. In the present study, sterol analyses of P. carinii hominis organisms isolated from cryopreserved human P. carinii-infected lungs and from bronchoalveolar lavage fluid were performed. Several of the same distinct sterols (e.g., fungisterol and methylcholest-7-ene-3beta-ol) previously identified in P. carinii carinii were also present in organisms isolated from human specimens. Pneumocysterol was detected in only some of the samples.
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Holmén JB, Ekesten B, Lundgren B. Naphthalene-induced cataract model in rats: A comparative study between slit and retroillumination images, biochemical changes and naphthalene dose and duration. Curr Eye Res 1999; 19:418-25. [PMID: 10520218 DOI: 10.1076/ceyr.19.5.418.5296] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
PURPOSE The purpose of the study was to compare different methods of photographic evaluation of cataract formation in rats in response to different regimes of naphthalene treatment. Furthermore, we intended to study the relationship between cataract extension and biochemical parameters. METHODS Brown Norway rats were treated with 0.10-1.5 g naphthalene/kg body weight, twice a week for ten weeks to induce cataract or placebo. Slit illumination and retroillumination (SI and RI) photographs were produced by an EAS-1000 instrument to document cataract formation as light-scattering intensity. The degree of the cataractous changes was quantified in SI photographs by the peak height and the integrated peak area, and in RI photographs by threshold setting. Finally, the lens concentration of Na(+) and K( +) and the protein composition were analyzed and correlated to the photographic analysis. RESULTS The degree of the cataractous changes was most linearly related to dose and duration when the integrated peak area was estimated. However, protein fractions were non-linearly related to the cataractous changes estimated. Alterations in concentration of Na(+) and K(+) were small or insignificant, which indicate that naphthalene-induced cataract is not caused by osmotic changes. The lowest possible naphthalene dose to induce cataractous changes was between 0.10 and 0.50 g/kg twice a week for ten weeks. CONCLUSIONS 0.50 and 1.0 g naphthalene/kg twice a week appeared to be optimal, because the rats in these groups were healthy and the cataractous changes were consistent between animals. Thus, the combination of the animal model with the cataract quantification system has the potential to be useful and reliable in studies of cataract-preventive compounds.
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Helweg-Larsen J, Benfield TL, Eugen-Olsen J, Lundgren JD, Lundgren B. Effects of mutations in Pneumocystis carinii dihydropteroate synthase gene on outcome of AIDS-associated P. carinii pneumonia. Lancet 1999; 354:1347-51. [PMID: 10533864 DOI: 10.1016/s0140-6736(99)03320-6] [Citation(s) in RCA: 172] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND Sulpha drugs are widely used for the treatment and long-term prophylaxis of Pneumocystis carinii pneumonia (PCP) in HIV-1-infected individuals. Sulpha resistance in many microorganisms is caused by point mutations in dihydropteroate synthase (DHPS), an enzyme that is essential for folate biosynthesis. We assessed whether mutations in the DHPS gene of P. carinii were associated with exposure to sulpha drugs and influenced outcome from PCP. METHODS We studied bronchoalveolar samples collected in 1989-99 from a prospective cohort of HIV-1-infected patients who had PCP. In 144 patients with 152 episodes of PCP, we analysed portions of DHPS using PCR and direct sequencing. The relation between survival, P. carinii DHPS mutations, and other predictors of treatment failure was assessed by Kaplan-Meier and multivariate Cox regression analysis. FINDINGS P. carinii DHPS mutations were found in 31 (20.4%) of 152 PCP episodes. 3-month survival was significantly lower in patients infected with mutant P. carinii DHPS strains than in those with wild-type strains (p=0.002). After adjustment for other prognostic variables, presence of DHPS mutations remained the most important predictor of mortality (hazard ratio 3.1 [95% CI 1.2-8.1]). DHPS mutations were significantly more common in patients who had previous exposure to sulpha drugs (18 of 29 [62%]) than in those who had no exposure (13 of 123 [10.5%]; p<0.0001). A significant increase with time in the rate of DHPS mutations (p=0.01 for trend) was closely correlated with the rate of previous or current use of sulpha drugs as chemoprophylaxis. INTERPRETATION Mutations in DHPS are associated with impaired prognosis in PCP, and may develop as a result of exposure to sulpha drugs.
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Matos O, Lundgren B, Aguiar P, Costa M, Antunes F. Comparison of four methods for extraction of Pneumocystis carinii DNA from pulmonary specimens and serum. J Eukaryot Microbiol 1999; 46:102S-103S. [PMID: 10519267] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/14/2023]
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Matos O, Lundgren B, Caldeira L, Mansinho K, Aguiar P, Forte M, Antunes F. Evaluation of a nested PCR for detection of Pneumocystis carinii in serum from immunocompromised patients. J Eukaryot Microbiol 1999; 46:104S-105S. [PMID: 10519268] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/14/2023]
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Abstract
Data of chemical emissions from flooring materials have been collected and investigated in a database known as METS. The emission tests are performed using the Field and Laboratory Emission Cell (FLEC). The emission rates of total volatile organic compounds (TVOC) in the boiling point range of hexane to octadecane varies from around 4,000 micrograms/(m2.h) to less than 10 micrograms/(m2.h). Results obtained 1994/95 are presented and compared with the results obtained in 1992 for similar materials. The tests are performed 4 weeks and 26 weeks after the manufacturing of the material. The emission rates of TVOC decrease on the average approximately 60% from 4 to 26 weeks. The differences and trends in emission rates of individual chemicals and their use are discussed. For many VOCs emission rates decrease rapidly and become near to or below 2 micrograms/(m2.h) (the detection limit) after 26 weeks. For a small number of individual compounds the emission rate decrease little over 26 weeks. A small number of chemicals are singled out for particular interest in a health and comfort evaluation based on the emission results.
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Benfield TL, Lundgren B, Shelhamer JH, Lundgren JD. Pneumocystis carinii major surface glycoprotein induces interleukin-8 and monocyte chemoattractant protein-1 release from a human alveolar epithelial cell line. Eur J Clin Invest 1999; 29:717-22. [PMID: 10457157 DOI: 10.1046/j.1365-2362.1999.00517.x] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
BACKGROUND The major surface glycoprotein (MSG) is an abundant, immunogenic glycoprotein located on the surface of Pneumocystis carinii. Little is known about the proinflammatory effects of MSG. DESIGN We have investigated the effect of human MSG on the secretion of the chemokines interleukin 8 (IL-8) and monocyte chemoattractant protein-1 (MCP-1) from an alveolar epithelial cell line (A549). RESULTS Incubation of A549 cells with MSG in concentrations from 0.4 to 10 microg mL-1 for 24 h caused dose-dependent increases in IL-8 release (3.4-fold above control, P < 0.01). Time course experiments showed increases in IL-8 release at 4 h, 8 h and 24 h compared with control cultures (all P < 0.01). There was a minor (13%) dose- and time-related increase in MCP-1 release at 24 h (P = 0.02). Co-incubation of MSG with mannan or beta-glucan decreased IL-8 release by 48% and 42% respectively, suggesting that MSG stimulates A549 cells in part through carbohydrate moieties. Dexamethasone significantly inhibited MSG-induced IL-8 release in concentrations of 10-6-10-8 mol L-1 compared with control experiments (P < 0.01). Ribonuclease protection assays for steady-state IL-8 mRNA showed that increases in response to MSG stimulation occurred by 4 h and persisted throughout 8 h of stimulation. CONCLUSION These findings suggest that MSG can alter alveolar epithelial cytokine release and may be capable of modulating the local inflammatory response in this manner.
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Xia Z, Lundgren B, Bergstrand A, DePierre JW, Nässberger L. Changes in the generation of reactive oxygen species and in mitochondrial membrane potential during apoptosis induced by the antidepressants imipramine, clomipramine, and citalopram and the effects on these changes by Bcl-2 and Bcl-X(L). Biochem Pharmacol 1999; 57:1199-208. [PMID: 11230808 DOI: 10.1016/s0006-2952(99)00009-x] [Citation(s) in RCA: 87] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/16/2022]
Abstract
In order to investigate the molecular mechanism of the antineoplastic effects exerted by the antidepressive agents imipramine, clomipramine, and citalopram, we examined the effects of these compounds on cell viability, generation of reactive oxygen species (ROS), and mitochondrial membrane potential (DeltaPsi(m)) in human acute myeloid leukemia HL-60 cells. Our results indicate that exposure to these compounds causes a loss in cell viability by activating the apoptotic process, as identified by electron microscopy, DNA gel electrophoresis, and flow cytometry. The increased generation of ROS induced by these drugs was a relatively early event and preceded the loss of DeltaPsi(m). Overexpression of the antiapoptotic protein Bcl-2 or Bcl-X(L) prevents antidepressant-induced apoptosis, as well as loss of DeltaPsi(m), but does not affect the generation of ROS.
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Wester P, Rådberg J, Lundgren B, Peltonen M. Factors associated with delayed admission to hospital and in-hospital delays in acute stroke and TIA: a prospective, multicenter study.Seek- Medical-Attention-in-Time Study Group. Stroke 1999; 30:40-8. [PMID: 9880386 DOI: 10.1161/01.str.30.1.40] [Citation(s) in RCA: 156] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND AND PURPOSE Early admission to hospital followed by correct diagnosis with minimum delay is a prerequisite for successful intervention in acute stroke. This study aimed at clarifying in detail the factors related to these delays. METHODS This was a prospective, multicenter, consecutive study that explored factors influencing the time from stroke or transient ischemic attack (TIA) onset until patient arrival at the emergency department, stroke unit, and CT laboratory. Within 3 days of hospital admission, the patients and/or their relatives were interviewed by use of a standardized structured protocol, and the patients' neurological deficits were assessed. No information about this study was given to the public or to the staff. RESULTS Patients (n=329) were studied at 15 Swedish academic or community-based hospitals: 252 subjects with brain infarct, 18 with intracerebral hemorrhage, and 59 with TIA. Among stroke and TIA patients, the median times from onset to hospital admission, stroke unit, and CT scan laboratory were 4.8 and 4.0 hours, 8.8 and 7.5 hours, and 22.0 and 17.5 hours, respectively. From multivariate ANOVA with logarithmically transformed time for increasing delay to hospital admission as the dependent variable, a profile of significant risk factors was obtained. This included patients with a brain infarct, gradual onset, mild neurological symptoms, patients who were alone and did not contact anybody when symptoms occurred, patients who lived in a large catchment area, those who did not use ambulance transportation, and those who visited a primary care site. These factors explained 45.3% of the variance in delayed hospital admission. The median time from arrival at the emergency department to arrival at the stroke unit or CT scan laboratory (whichever occurred first) was 2.6 and 2.7 hours in the stroke and TIA groups, respectively. A large catchment area, moderate to mild neurological deficit, and waiting for the physician at the emergency department were all significantly related to in-hospital delay. CONCLUSIONS Increased public awareness of the need to seek medical or other attention promptly after stroke onset, to use an ambulance with direct transportation to the acute-care hospital, and to have more effective in-hospital organization will be required for effective acute treatment options to be available to stroke patients.
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