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Biomedical subjects

B Jensen

Publications and source records attributed to B Jensen.

At least 37 records · Page 2Linked to original sources
PubMed2001

Benzodiazepines in child dental care: a survey of its use among general practitioners and paediatric dentists in Sweden.

Dental treatment in children too young or too apprehensive to co-operate is often performed under sedation. The aim of this study was to survey the use of rectal and oral liquid and tablet benzodiazepine sedation in Swedish child dentistry, and estimation of treatment success. A questionnaire was sent to 500 randomly selected dentists (GPs) working in the Public Dental Health Service and all (77) specialists (PDs) working at paediatric dentistry clinics. Benzodiazepine sedation was used by 73% of the GPs and 97% of the PDs. Seven per cent of the GPs and 87% of the PDs had sedation sessions at least once a month. Of the GPs, 60% administered the sedation rectally, 7% orally in liquid form, and 39% orally in tablet form. For PDs, the corresponding figures were 97%, 78%, and 68%. Sixteen per cent of the GPs and 84% of the PDs used midazolam for rectal sedation. PDs rated rectal sedation better than the GPs (p < 0.001). GPs rated their experiences of rectal sedation as better the more frequent the use (p = 0.03), as did PDs concerning oral liquid sedation (p = 0.03). Thus, it seems that a more regular use of sedation is advantageous in achieving better treatment outcome.

Administration, Oral↗
PubMed2000

CXC chemokine receptor 3 expression on CD34(+) hematopoietic progenitors from human cord blood induced by granulocyte-macrophage colony-stimulating factor: chemotaxis and adhesion induced by its ligands, interferon gamma-inducible protein 10 and monokine induced by interferon gamma.

CXC chemokine receptor 3 (CXCR3), which is known to be expressed predominately on memory and activated T lymphocytes, is a receptor for both interferon gamma (IFN-gamma)-inducible protein 10 (gamma IP-10) and monokine induced by IFN-gamma (Mig). We report the novel finding that CXCR3 is also expressed on CD34(+) hematopoietic progenitors from human cord blood stimulated with granulocyte-macrophage colony-stimulating factor (GM-CSF) but not on freshly isolated CD34(+) progenitors. Freshly isolated CD34(+) progenitors expressed low levels of CXCR3 messenger RNA, but this expression was highly up-regulated by GM-CSF, as indicated by a real-time quantitative reverse transcriptase-polymerase chain reaction technique. gamma IP-10 and Mig induced chemotaxis of GM-CSF-stimulated CD34(+) progenitors by means of CXCR3, since an anti-CXCR3 monoclonal antibody (mAb) was found to block gamma IP-10-induced and Mig-induced CD34(+) progenitor chemotaxis. These chemotactic attracted CD34(+) progenitors are colony-forming units-granulocyte-macrophage. gamma IP-10 and Mig also induced GM-CSF-stimulated CD34(+) progenitor adhesion and aggregation by means of CXCR3, a finding confirmed by the observation that anti-CXCR3 mAb blocked these functions of gammaIP-10 and Mig but not of chemokine stromal cell-derived factor 1 alpha. gamma IP-10-induced and Mig-induced up-regulation of integrins (CD49a and CD49b) was found to play a crucial role in adhesion of GM-CSF-stimulated CD34(+) progenitors. Moreover, gamma IP-10 and Mig stimulated CXCR3 redistribution and cellular polarization in GM-CSF-stimulated CD34(+) progenitors. These results indicate that CXCR3-gamma IP-10 and CXCR3-Mig receptor-ligand pairs, as well as the effects of GM-CSF on them, may be especially important in the cytokine/chemokine environment for the physiologic and pathophysiologic events of differentiation of CD34(+) hematopoietic progenitors into lymphoid and myeloid stem cells, subsequently immune and inflammatory cells. These processes include transmigration, relocation, differentiation, and maturation of CD34(+) hematopoietic progenitors. (Blood. 2000;96:1230-1238)

Antigens, CD34↗
PubMed2000

Free polyunsaturated fatty acids cause taste deterioration of salmon during frozen storage.

Increased intensity of train oil taste, bitterness, and metal taste are the most pronounced sensory changes during frozen storage of salmon (Refsgaard, H. H. F.; Brockhoff, P. B.; Jensen, B. Sensory and Chemical Changes in Farmed Atlantic Salmon (Salmo salar) during Frozen Storage. J. Agric. Food Chem. 1998a, 46, 3473-3479). Addition of each of the unsaturated fatty acids: palmitoleic acid (16:1, n - 7), linoleic acid (C18:2, n - 6), eicosapentaenoic acid (EPA; C20:5, n - 3) and docosahexaenoic acid (DHA; C22:6, n - 3) to fresh minced salmon changed the sensory perception and increased the intensity of train oil taste, bitterness, and metal taste. The added level of each fatty acid ( approximately 1 mg/g salmon meat) was equivalent to the concentration of the fatty acids determined in salmon stored as fillet at -10 degrees C for 6 months. The effect of addition of the fatty acids on the intensity of train oil taste, bitterness and metal taste was in the order: DHA > palmitoleic acid > linoleic acid > EPA. Formation of free fatty acids was inhibited by cooking the salmon meat before storage. Furthermore, no changes in phospholipid level were observed during frozen storage. The results suggest that enzymatic hydrolysis of neutral lipids plays a major role in the sensory deterioration of salmon during frozen storage.

Adult↗
PubMed2000

Identification of a point mutation in the voltage-gated sodium channel gene of Kenyan Anopheles gambiae associated with resistance to DDT and pyrethroids.

A field trial of permethrin-impregnated bednets and curtains was initiated in Western Kenya in 1990, and a strain of Anopheles gambiae showing reduced susceptibility to permethrin was colonized from this site in 1992. A leucine-phenylalanine substitution at position 1014 of the voltage-gated sodium channel is associated with resistance to permethrin and DDT in many insect species, including Anopheles gambiae from West Africa. We cloned and sequenced a partial sodium channel cDNA from the Kenyan permethrin-resistant strain and we identified an alternative substitution (leucine to serine) at the same position, which is linked to the inheritance of permethrin resistance in the F(2) progeny of genetic crosses between susceptible and resistant individuals. The diagnostic polymerase chain reaction (PCR) developed by Martinez-Torres et al. [(1998) Insect Mol Biol 7: 179-184] to detect kdr alleles in field populations of An. gambiae will not detect the Kenyan allele and hence reliance on this assay may lead to an underestimate of the prevalence of pyrethroid resistance in this species. We adapted the diagnostic PCR to detect the leucine-serine mutation and with this diagnostic we were able to demonstrate that this kdr allele was present in individuals collected from the Kenyan trial site in 1986, prior to the introduction of pyrethroid-impregnated bednets. The An. gambiae sodium channel was physically mapped to chromosome 2L, division 20C. This position corresponds to the location of a major quantitative trait locus determining resistance to permethrin in the Kenyan strain of An. gambiae.

Amino Acid Substitution↗
PubMed2000

Genetic mapping of two loci affecting DDT resistance in the malaria vector Anopheles gambiae.

Resistance to the insecticide DDT in the mosquito vectors of malaria has severely hampered efforts to control this disease and has contributed to the increase in prevalence of malaria cases seen in recent years. Over 90% of the 300-500 million annual cases of malaria occur in Africa, where the major vector is Anopheles gambiae. DDT resistance in the ZAN/U strain of An. gambiae is associated with an increased metabolism of the insecticide, catalysed by members of the glutathione S-transferase (GST) enzyme family, but the molecular mechanism underlying this metabolic resistance is not known. Genetic crosses show that resistance is autosomal and semidominant. We have used microsatellite markers to identify two quantitative trait loci (QTL), which together explain over 50% of the variance in susceptibility to DDT in the ZAN/U strain of An. gambiae. The first locus, rtd1, is on chromosome 3 between markers H341 and H88 and has a recessive effect with respect to susceptibility. The second locus, rtd2 is on chromosome 2L, close to marker H325 and has an additive genetic effect. The markers flanking these two QTL have been physically mapped to An. gambiae polytene chromosomes. They do not coincide with any of the GST genes that have been cloned and mapped in this species. Characterization of these QTL will lead to a clearer understanding of the mechanisms of metabolic resistance to DDT.

Animals↗
PubMed2000

Search for Borna disease virus in Danish fibromyalgia patients.

OBJECTIVE: The purpose of this study was to look for Borna disease virus (BDV) in 18 patients with acute onset of fibromyalgia (FMS) following a "flu-like" episode. BDV is a neurotropic RNA virus affecting horses and sheep. Infections in animals have been reported to cause immune mediated disease characterized by abnormalities in behavior. A possible link between BDV and neuropsychiatric diseases in man has been described, and lately a connection to chronic fatigue syndrome (CFS) has been suggested. METHODS: A BDV-specific nested PCR (RT-PCR) was performed on serum and spinal fluid. RESULTS: The BDV genome was not detected in any of the FMS cases. CONCLUSION: Although BDV was not demonstrated in spinal fluid or serum from the tested patients with FMS, we believe that it is important to report our results, since FMS can exhibit many manifestations in common with CFS. Possible reasons for the discrepant findings are discussed.

Adult↗
PubMed2000

Benzimidazoles in the treatment of alveolar echinococcosis: a comparative study and review of the literature.

Mebendazole and albendazole are the drugs of choice for the treatment of alveolar echinococcosis. In this open-labelled observational study we present and evaluate the outcome of long-term treatment with these drugs and present results of different treatment regimens. Thirty-five patients were started on either mebendazole or albendazole at the beginning of 1992 and followed for an average of 39 months (range 12-79 months). Treatment was classed as successful if the disease had not progressed for >1 year and if there were no side-effects necessitating a change of treatment. Lack of progression was evaluated mainly using ultrasound and computed tomography and was further substantiated by laboratory tests and clinical findings. The overall success rate was 97%. An initial regimen for cases of alveolar echinococcosis was recurrence-free in 71% of those treated with mebendazole and in 78% of those treated with albendazole. Four out of five cases with progressive disease stabilized after the therapeutic regimen was changed. Seven patients received a continuous regimen with albendazole. These patients were observed over an average of 28 months (range 13-50 months) without signs of progression or significant side-effects. This open-labelled prospective study demonstrates the high therapeutic efficacy of both mebendazole and albendazole with similar response rates in the treatment of alveolar echinococcosis. Albendazole reduced costs by >40% and is easier for patients to take, further arguing in favour of its preferred use. Albendazole in alveolar echinococcosis is only licensed for intermittent application. None the less, continuous treatment is safe and well tolerated and showed promising results when applied to patients in whom other treatment regimens had failed. It should thus be strongly considered in inoperable cases or progressive disease.

Adolescent↗
PubMed2000

Prevalence of hepatitis C virus seropositivity among hospitalized US veterans.

BACKGROUND: Hepatitis C virus (HCV) is a major cause of acute and chronic hepatitis in the United States and abroad. HCV antibody prevalences ranging from 10 to 90% have been reported in intravenous drug abusers, hemodialysis patients, and persons suffering from other liver diseases, whereas HCV seropositivity rates for volunteer-blood donor populations are generally under 1%. However no information has been available concerning the prevalence of HCV in general hospital populations in the United States. METHODS: We examined the rate of HCV seropositivity in 530 patients admitted to the Atlanta VA Medical Center between November 1993 and November 1994. The test population consisted of 400 random hospital admissions, 100 successive admissions to the surgical service, and 30 random admissions to the gastrointestinal service. Serum samples were assayed for HCV antibodies by a second generation EIA, and all repeat reactives were re-examined using a supplemental research assay to confirm the presence of HCV antibodies. Complete chart reviews were carried out on all HCV seropositive patients and on 100 HCV seronegative patients. RESULTS: Sixty-two of the 530 patients tested (11.7%) were repeatedly positive for HCV antibodies. Of these 62 repeat reactives, 56 (90.3%) were positive and 3 others (4.8%) indeterminate by the supplemental assay. The HCV seropositivity rate after supplemental testing was 11.8% for random admissions, 5.0% for surgical admissions, and 13.3% for patients admitted to the gastroenterology service. HCV-associated risk factors in HCV seropositive patients included a history of intravenous drug abuse, current or previous alcohol abuse, previous or concurrent liver disease, previous blood transfusions, hemodialysis, and multiple sex partners or unsafe sex. CONCLUSIONS: HCV infection may be more prevalent among hospitalized VA patients (and among other US hospital populations) than previously expected.

Adult↗
PubMed2000

Transition radiation and the origin of sonoluminescence

It has been shown by Liberati et al. [Phys. Rev. D 61, 85023 (2000)] that a dielectric medium with a time-dependent refractive index may produce photons. We point out that a free electric charge that interacts with such a medium will emit quantum-mechanically modified transition radiation in which an arbitrary odd number of photons will be present. Excited atomic electrons will also exhibit a similarly modified emission spectrum. This effect may be directly observable in connection with sonoluminescence.

Journal Article↗
PubMed2000

Comparison of polyvinyl alcohol fixative with three less hazardous fixatives for detection and identification of intestinal parasites.

Polyvinyl alcohol (PVA) containing the fixative mercuric chloride is considered the "gold standard" for the fixation of ova and parasites in the preparation of permanently stained smears of stool specimens. However, mercuric chloride is potentially hazardous to laboratory personnel and presents disposal problems. We compared three new alternative, nontoxic fixatives with PVA, analyzing ease of sample preparation and quality of smears. Sixty-eight fresh stool specimens were divided into aliquots and placed in each of four different fixatives: PARASAFE (PS) (Scientific Devices Laboratory, Inc., Des Plaines, Ill.), ECOFIX (EC) (Meridian Diagnostics, Inc., Cincinnati, Ohio), Proto-Fix (PF) (Alpha-Tec Systems, Inc., Vancouver, Wash.), and low-viscosity PVA fixative (PVA) (Meridian). Specimens were processed and stained according to each manufacturer's directions. Parasites were found in 31 of 68 slide preparations with PVA, 31 with PF, 30 with EC, and 30 with PS. Blastocystis hominis and Iodamoeba bütschlii were preserved in a readily identifiable state by all methods of fixation. However, some parasites were more easily identified with some of the fixatives because of differences in parasite distortion. For example, Entamoeba histolytica (Entamoeba dispar) was detected in 13 stools fixed with PF, 7 with PVA, and 6 with EC but none with PS. Likewise, Chilomastix mesnili was identified in 13 specimens fixed with PF, 8 with EC, and 5 with PVA but only 1 with PS, while Entamoeba coli was seen much less frequently with PS than with the other three fixatives. A dirty background was observed in 41% of specimens prepared with PS, whereas background quality was acceptable with other fixatives. Sample preparation was most rapid with PS, although the EC method involved the fewest steps. In conclusion, PVA and PF produced the least parasite distortion, while PS proved unsatisfactory for the identification of E. histolytica, E. coli, and C. mesnili. Both PF and EC appear to be acceptable, environmentally safe substitutes for PVA.

Animals↗
PubMed1999

Pharmacokinetics of sparfloxacin in patients with renal impairment.

Sparfloxacin is a fluoroquinolone antimicrobial agent with a broad spectrum of activity and long elimination half-life. Because its single-dose pharmacokinetics are altered by renal impairment, the present study was undertaken to determine the effects of moderate or severe renal insufficiency on the multidose pharmacokinetic characteristics of and tolerance to sparfloxacin. The pharmacokinetic characteristics of sparfloxacin were assessed in 32 subjects (15 men, 17 women) with (1) normal renal function (creatinine clearance [CLcr]> or = 250 mL/min per 1.73 m2) and a mean age of 52.6 years and mean weight of 70.4 kg; (2) moderate renal insufficiency (CLcr 30-49 mL/min per 1.73 m2) and a mean age of 54.4 years and mean weight of 67.8 kg; and (3) severe renal insufficiency (CLcr 10-29 mL/min per 1.73 m2) and a mean age of 50.8 years and mean weight of 73.1 kg. The first 2 groups received a 400-mg loading dose on day 1 followed by 200 mg once daily for 9 days; subjects with severe renal insufficiency received a 400-mg loading dose on day 1 followed by 200 mg every 48 hours on days 3, 5, 7, and 9. The plasma and urinary pharmacokinetics of sparfloxacin and its glucuronide metabolite were determined after the last dose. All subjects were monitored for changes in the corrected QT (QTc) interval and for adverse events. Renal insufficiency altered the steady-state pharmacokinetic variables of sparfloxacin and its glucuronide metabolite, reducing their renal clearances and increasing both maximum plasma concentration and area under the plasma concentration-time curve. Mean steady-state plasma sparfloxacin concentrations in subjects with severe renal insufficiency (48-hour dosing interval) were comparable to those in subjects with normal renal function (24-hour dosing interval). However, mean plasma sparfloxacin concentrations in patients with moderate renal insufficiency were 2 to 3 times greater than the corresponding concentrations in subjects with normal renal function receiving the same dosage regimen. The QTc interval was slightly increased in all groups (the greatest increases were 14, 14, and 6 milliseconds in the groups with normal renal function and moderately and severely impaired renal function, respectively, at 5.5 hours post-dose on day 9 or 10) but similar among subjects with normal renal function or with renal insufficiency. Sparfloxacin was well tolerated. Thus sparfloxacin clearance is reduced and plasma concentrations raised by moderate or severe renal insufficiency. These increases do not appear to augment drug effects on the QTc interval or enhance the risk for adverse events. These results suggest that alternate-day dosing (48-hour dosing interval) following a double loading dose on day 1 should be used in patients with severe renal insufficiency and may be appropriate for patients with moderate renal insufficiency.

Adult↗
PubMed1999

Isolation and quantification of volatiles in fish by dynamic headspace sampling and mass spectrometry.

A dynamic headspace sampling method for isolation of volatiles in fish has been developed. The sample preparation involved freezing of fish tissue in liquid nitrogen, pulverizing the tissue, and sampling of volatiles from an aqueous slurry of the fish powder. Similar volatile patterns were determined by use of this sample preparation method and for samples chewed for 10 s. Effects of sampling time, temperature, and purge flow on level of volatiles were tested. Purging at 340 mL/min for 30 min at 45 degrees C was found to be optimal. Detection limits for a number of aldehydes were 0.2-2.7 microg/kg. Levels of volatiles are given for fresh salmon, cod, saithe, mackerel, and redfish.

Aldehydes↗
PubMed1999

Pre- and post-treatment levels of salivary mutans streptococci and lactobacilli in pre-school children.

OBJECTIVES: To examine the effect of operative and restorative treatment of dental caries on the levels of caries associated microorganisms in saliva and to relate alterations to the type and extent of treatment. DESIGN: Longitudinal. SETTING: Paediatric Dentistry Department at a central hospital in Sweden. SUBJECTS AND METHODS: One hundred and eight pre-school children with severe dental caries scheduled for treatment under general anaesthesia. Chair-side tests were used to estimate the levels of salivary mutans streptococci, lactobacilli and buffer capacity before the surgery and at recall appointments 1 and 6 months after treatment. Caries were assessed according to WHO guidelines and the number of extracted teeth and filled surfaces during surgery were recorded. RESULTS: The results demonstrate that the post-treatment levels of mutans streptococci and lactobacilli were significantly reduced (P < 0.001) compared to pretreatment levels. Lactobacilli levels were more dramatically reduced than mutans streptococci. The reduction of mutans streptococci was positively correlated to the number of extracted teeth (P < 0.01), but not to the number of restored or ground surfaces. Lactobacilli reduction was not significantly related to the type of treatment. CONCLUSION: The findings suggest that extensive operative and restorative dental care effectively reduces the levels of caries associated with microorganisms during a period of at least 6 months.

Anesthesia, Dental↗
PubMed1999

Rectal sedation with diazepam or midazolam during extractions of traumatized primary incisors: a prospective, randomized, double-blind trial in Swedish children aged 1.5-3.5 years.

The aim of this study was to compare rectal sedation with diazepam and rectal sedation with midazolam with regard to sedative effect, treatment acceptance, and amnesia. Ninety children, 1.5-3.5 years of age, consecutively referred for extractions of traumatized primary incisors were randomly sedated with diazepam (0.7 mg/kg body weight) or midazolam (0.3 mg/kg body weight). The study design was randomized and double-blind. The level of sedation (state of mind) was assessed prior to and 10 and 60 min after administration of the drug by use of a behavioral scale (Wilton). The children's acceptance of procedures was assessed using another behavioral scale (Holst) during administration of the sedative, application of topical anesthesia, injection of a local anesthesia, and extraction. Amnesia was evaluated by the parents on the following day, with the child being asked standardized questions. Parental ratings of the child's and their own distress during and after treatment were made on a visual analog scale (VAS). No differences were found between the sedatives concerning level of sedation during treatment, acceptance of procedures, or amnesia. At discharge, 60 min after administration of the sedative, the children receiving diazepam were significantly more agitated (P=0.006). Parental rating on a VAS of the child's discomfort after treatment was significantly higher in the diazepam group (P=0.006). There was a tendency for children with poor acceptance of the rectal administration to display a more negative acceptance of the dental treatment. In conclusion, the present results, in combination with known pharmacological advantages, indicate that midazolam is preferable in outpatients when sedation is needed and amnesia is desirable.

Administration, Rectal↗
PubMed1998

Uptake of phenylacetic acid by two strains of Penicillium chrysogenum.

Uptake of phenylacetic acid, the side-chain precursor of benzylpenicillin, was studied in Penicillium chrysogenum Wisconsin 54-1255 and in a strain yielding high levels of penicillin. In penicillin fermentations with the high-yielding strain, 100% recovery of phenylacetic acid in benzylpenicillin was found, whereas in the Wisconsin strain only 17% of the supplied phenylacetic acid was incorporated into benzylpenicillin while the rest was metabolized. Accumulation of total phenylacetic acid-derived carbon in the cells was nonsaturable in both strains at high external concentrations of phenylacetic acid (250-3500 microM), and in the high-yielding strain at low phenylacetic acid concentrations (2. 8-100 microM), indicating that phenylacetic acid enters the cells by simple diffusion, as concluded earlier for P. chrysogenum by other authors. However, at low external concentrations of phenylacetic acid saturable accumulation appeared in the Wisconsin strain. HPLC-analyses of cell extracts from the Wisconsin strain showed that phenylacetic acid was metabolized immediately after entry into the cells and different [14C]-labeled metabolites were detected in the cells. Up to approximately 50% of the accumulated phenylacetic acid was metabolized during the transport-assay period, the conversion having an impact on the uptake experiments. Nevertheless, accumulation of free unchanged phenylacetic acid in the cells showed saturation kinetics, suggesting the possible involvement of a high-affinity carrier in uptake of phenylacetic acid in P. chrysogenum Wisconsin 54-1255. At high concentrations of phenylacetic acid, contribution to uptake by this carrier is minor in comparison to simple diffusion and therefore, of no importance in the industrial production of penicillin.

Bacteriological Techniques↗
PubMed1998

Micellar electrokinetic capillary chromatography for therapeutic drug monitoring of carbamazepine and its main metabolites.

In carbamazepine (CBZ) therapy the concomitant monitoring of concentrations of CBZ and its metabolites is strictly recommended, primarily to avoid toxic side effects. Currently, clinical routine monitoring of CBZ is accomplished by high-performance liquid chromatography or immunological methods. In this study a micellar electrokinetic capillary chromatographic (MECC) method was developed for routine drug monitoring of CBZ and its main metabolites, carbamazepine 10,11-diol and carbamazepine 10,11-epoxide, in human serum or plasma samples. The MECC method enabled baseline separation of all analytes within 2.5 min. The assay revealed sufficient precision and sensitivity and the results of either an automated HPLC or the MECC chromatography assay were in good agreement (r=-0.97). The maximum deviation for CBZ was 0.26 microM.

Anticonvulsants↗
PubMed1998

Effect of N-linked glycosylation on secretion, activity, and stability of alpha-amylase from Aspergillus oryzae.

The effect of N-linked glycosylation on secretion, activity, and stability of alpha-amylase from Aspergillus oryzae grown as dispersed filaments was studied. In the presence of tunicamycin the fungus grew either as dispersed filaments or as one large pellet, whereas growth was as dispersed filaments in all control cultures. The presence of tunicamycin affected neither biomass, level of secreted alpha-amylase, nor total amount of secreted protein in cultures growing as dispersed filaments. In these cultures both glycosylated and nonglycosylated alpha-amylase appeared in the culture medium as well as in the cells, whereas in control cultures only the glycosylated form of alpha-amylase was found in the medium and in the cells. The presence of nonglycosylated alpha-amylase in the medium seemed to result from active secretion rather than from autolysis of the mycelium or extracellular deglycosylation. Deglycosylation with Endo H of crude alpha-amylase in culture filtrate did not affect its stability towards heat, acid pH, or proteolytic degradation.

Aspergillus oryzae↗