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Biomedical subjects

A G Jensen

Publications and source records attributed to A G Jensen.

At least 19 recordsLinked to original sources
PubMed2002

Direct identification and susceptibility testing of enteric bacilli from positive blood cultures using VITEK (GNI+/GNS-GA).

OBJECTIVE: To study the possibility of reporting results of identification and susceptibility testing of Gram-negative bacilli the same day as bacteremia is detected by using direct inoculation from positive blood cultures (Bactec 9240) into VITEK GNI+ and GNS-GA cards. METHODS: All blood cultures with Gram-negative enteric bacillus-like morphology on microscopy found to be positive on workdays between 15 June 1999 and 29 February 2000 were included. Identification and susceptibility testing were done by three methods: the direct method using a suspension made by differential centrifugation of positive blood culture broth for inoculation of the VITEK cards; the standard method using an inoculum made from an overnight culture on a solid media; and the routine method (reference method) using conventional testing. RESULTS: Of 169 isolates, the direct method resulted in 75% correct identifications, 9% misidentifications and 17% non-identifications. All misidentified isolates were Escherichia coli, of which 80% were reported as Salmonella arizonae. Five biochemical tests yielded most of the aberrant results; correcting the citrate and malonate reactions in most cases led to correct identification by the VITEK database. Despite a negative H2S reaction, 11 E. coli isolates were reported as S. arizonae. Two-thirds (69%) of identifications were reported within 6 h, and 95% of these were correct. The direct susceptibility testing method was assessable for 140 isolates. Correct results were found in 99% of isolate-antimicrobial combinations, and 85% were reported within 6 h. CONCLUSION: The direct VITEK method could correctly report identifications and susceptibility patterns within 6 h, making same-day reporting possible for almost two-thirds (63%) of bacteremic episodes with Gram-negative bacilli. These results could probably be improved by modification of the identification algorithms of the VITEK software.

Bacteremia↗
PubMed2002

Importance of focus identification in the treatment of Staphylococcus aureus bacteraemia.

Staphylococcus aureus bacteraemia increases in frequency, and it is still a life-threatening disease. In recent years, some interesting studies such as the need for focus identification and the focus eradication have been performed. The aim of this review is to present an up-to-date assessment of the current challenges in the management of S. aureus bacteraemia in order to improve the outcome.

Adolescent↗
PubMed2001

Adhyperforin as a contributor to the effect of Hypericum perforatum L. in biochemical models of antidepressant activity.

The present paper describe investigations which demonstrate that hyperforin is not the only phloroglucinol derivative in extracts of the medicinal plant Hypericum perforatum L., which possess a biological activity. Hyperforin was the major lipophilic constituent in two different extracts, whereas the amount of adhyperforin was approximately 10 times lower. Adhyperforin, like hyperforin, is a potent inhibitor of the uptake of dopamine, serotonin and noradrenaline. Neither hyperforin nor adhyperforin inhibited binding of the cocaine analogue, [3H]WIN 35,428 to the dopamine transporter. However, the known antidepressives imipramine, nomifensine and fluoxetine all inhibited binding of [3H]WIN 35,428, indicating that hyperforin and adhyperforin do not bind to the same site on the dopamine transporter as these compounds. Furthermore, hyperforin and adhyperforin did not prevent dopamine binding, but inhibited dopamine translocation. Our studies further support recent reports suggesting that the effect of hyperforin on uptake of monoamines is probably not caused by a direct effect of hyperforin on known sites on the transporters.

Animals↗
PubMed1999

Risk factors for hospital-acquired Staphylococcus aureus bacteremia.

BACKGROUND: Staphylococcus aureus bacteremia (SAB) acquired in hospitals continues to be a frequent and serious complication to hospitalization, and no previous case-control studies dealing with risk factors of this severe disease are available. METHODS: Based on a 1-year prospective analysis, the data from all patients with hospital-acquired SAB admitted to 4 hospitals in Copenhagen County, Denmark, from May 1, 1994, through April 30, 1995, were evaluated. Eighty-five patients with hospital-acquired SAB were matched to 85 control patients with a similar primary diagnosis at admission (matched controls). Of these, 62 patients with hospital-acquired SAB were compared with 118 other patients with a similar time of admission, who were randomly selected with no clinical evidence of SAB (unmatched controls). RESULTS: The incidence of hospital-acquired SAB was 0.71 per 1000 hospital admissions. The presence of a central venous catheter (odds ratio, 6.9; 95% confidence interval [CI], 2.8-17.0), anemia (odds ratio, 3.3; 95% CI, 1.4-7.6), and hyponatremia (odds ratio, 3.3; 95% CI, 1.5-7.0) was significantly associated with hospital-acquired SAB in a conditional and a usual logistic regression analysis. Nasal carriage was not an independent risk factor, but nasal carriers among patients in surgery (odds ratio, 4.0; 95% CI, 1.3-13.0) had a significantly higher risk for hospital-acquired SAB compared with matched and unmatched controls. The presence of hospital-acquired SAB increased the mortality rate 2.4-fold (95% CI, 1.1-5.2). CONCLUSIONS: The presence of a central venous catheter is an important risk factor, and hyponatremia and anemia are associated with the development of hospital-acquired SAB. Furthermore, hospital-acquired SAB in itself increases mortality.

Adolescent↗
PubMed1998

Bacteremic Staphylococcus aureus spondylitis.

BACKGROUND: The incidence of hematogenous Staphylococcus aureus osteomyelitis of the vertebral column is rapidly increasing and few studies dealing with the diagnosis, treatment, and outcome of this severe disease are available. METHODS: Based on a nationwide registration, the clinical and bacteriological data were reviewed from 133 cases with a positive blood culture for S aureus and symptoms of vertebral osteomyelitis in Denmark for the period 1980 to 1990. RESULTS: The 133 cases of vertebral S aureus osteomyelitis reviewed were mainly community-acquired infections (82%) in older patients (median age, 65 years) and often occurred with underlying diseases. Both symptoms and laboratory values were relatively unspecific. Bone scan methods proved to be more optimal for diagnosis of vertebral S aureus osteomyelitis in the early stages compared with conventional radiography that proved a lack of consistency in the formative stages. The infection was mostly (70%) localized in the lower part of the column. The recurrence rate and rate of therapeutic failure depended on the duration and dosage of penicillinase-stable penicillins, respectively. Patients treated with fusidic acid in addition to penicillinase-stable penicillins had a significantly lower recurrence rate. Based on these findings, we recommend treatment with penicillinase-stable penicillins and fusidic acid for a total of 8 weeks, with a daily dosage of penicillinase-stable penicillins higher than 4 g. CONCLUSIONS: The diagnosis of vertebral S aureus osteomyelitis based on clinical findings is difficult to ascertain. Bone scans are necessary because radiographic methods do not detect disease as early. Treatment with penicillinase-stable penicillins, at least 4 g/d for at least 8 weeks, is recommended.

Adolescent↗
PubMed1997

Increasing frequency of vertebral osteomyelitis following Staphylococcus aureus bacteraemia in Denmark 1980-1990.

From 1980 to 1990, 309 cases of haematogenous osteomyelitis were identified in Denmark. Haematogenous osteomyelitis of the vertebral column increased significantly (P < 0.01) from the first to the second half of the period due to an increased number of patients > 50 years of age with community-acquired infection. Vertebral osteomyelitis differed significantly from osteomyelitis of other bones in accordance to age distribution (median 66 vs. 16 years), male/female ratio (75/71 vs. 105/ 58) and patients with diabetes (13% vs. 6%). We found a higher risk of haematogenous osteomyelitis in patients > 50 years of age and among patients with community-acquired infection. The highest incidence (5%) of vertebral osteomyelitis in Staphylococcus aureus bacteraemia in this age group was found in cases without an identified portal of entry. The highest incidence (34%) of osteomyelitis of other bones was found in community-acquired cases in the age group 1-20 years and without an identified portal of entry. The present study discusses reasons for the continued increase of vertebral osteomyelitis among adults and describes incidence rates and major risk factors for developing haematogenous osteomyelitis among patients with S. aureus bacteraemia. We suggest that the localization of haematogenous S. aureus osteomyelitis is connected with the presence of red bone marrow.

Adolescent↗
PubMed1997

Intravenous versus intraperitoneal morphine before surgery to provide postoperative pain relief.

BACKGROUND: Opioid receptors have been demonstrated on peripheral afferent nerves throughout the body. The aim of the present study was to compare the effects of intravenous and intraperitoneal administration of morphine with regard to pain, postoperative morphine requirement, and recovery after major abdominal surgery, and to describe the pharmacokinetics of intraperitoneal morphine in humans. METHODS: In a double-blind manner, 30 patients scheduled for major abdominal surgery were randomized to either 50 mg of morphine intravenously (i.v.) or 50 mg of morphine intraperitoneally (i.p.) before operation. Pain was measured on a visual analogue scale and morphine requirements were registered for 3 days. Recovery was measured as time to oral intake of food, time to flatulence and days in hospital. Plasma morphine, morphine-3-glucuronide, and morphine-6-glucuronide concentrations were determined during the first 4 h after morphine administration. RESULTS: During the first postoperative hours there was less pain at rest (P = 0.02) and on coughing (P = 0.004) in the intravenous group. The requirement of additional morphine (P = 0.016) was lower in the intravenous group during the first postoperative day. No major differences in recovery were seen. The plasma concentrations of morphine measured as area under the curve (AUC) during the first 4 h were similar, but the intravenous group showed significantly higher concentrations of the active metabolite morphine-6-glucuronide, (P = 0.016), indicating a difference in pharmacokinetics after intraperitoneal compared to intravenous administration of morphine. CONCLUSION: Intraperitoneal administration of 50 mg of morphine before major abdominal surgery is less efficient in reducing pain and postoperative morphine requirements than the same amount of morphine given intravenously.

Adult↗
PubMed1996

A 6-month prospective study of hospital-acquired bacteremia in Copenhagen county.

During a 6-month period, 892 positive blood cultures were detected in the Copenhagen County hospitals. 302 (34%) were regarded as contaminations, and of the remaining cases 419 (71%) were community-acquired and 171 (29%) hospital-acquired, giving incidence rates of 6.8/1,000 admissions and 2.8/1,000 admissions, respectively. Both frequency and rate of hospital-acquired bacteremia were lower compared to most other studies. E. coli was more commonly found in community-acquired infections, while coagulase-negative staphylococci were the organisms most often considered as a contaminant. The main causative organisms in hospital-acquired infections were S. aureus (n = 37) and E. coli (n = 34). The proportion of polymicrobial bacteremias in this study was lower compared to most other studies (8%). E. coli from hospital-acquired infections were resistant to ampicillin in 42% of cases, but other Enterobacteriaceae showed higher percentage of resistance to beta-lactam antibiotics. S. aureus was penicillin-resistant in 92% of cases, but no methicillin-resistant strains were isolated. The frequency of antibiotic resistance was low compared to reports from other countries. A total of 136 hospital-acquired cases were followed prospectively. 61% of the patients were male and 46% were > or = 60 years of age. Most patients had predisposing diseases, 90% had foreign body and/or recent surgery performed, and 74 (54%) had an intraveneous catheter. The portal of entry was known in 132 (97%) of the cases, the most common being the urinary tract (42%), followed by an intravenous catheter (30%). The prevalence of urinary tract catheters gave an increased number of cases with E. coli bacteremia. The mortality was 16%.

Adolescent↗
PubMed1995

A random trial comparing recovery after midazolam-alfentanil anesthesia with and without reversal with flumazenil, and standardized neurolept anesthesia for major gynecologic surgery.

STUDY OBJECTIVE: To compare the recovery characteristics of total intravenous anesthesia (TIVA) using midazolam-alfentanil, with or without reversal with flumazenil to a standardized neurolept anesthesia with nitrous oxide (N2O). DESIGN: Randomized, double-blinded clinical study. SETTING: University medical center. PATIENTS: 80 ASA physical status I and II women scheduled for major elective gynecologic surgery. INTERVENTIONS: Patients were anesthetized with one of three different anesthetic techniques. Patients in the TIVA group with reversal received midazolam-alfentanil reversed with flumazenil (Group 1), the TIVA group without reversal received midazolam-alfentanil reversed with placebo (Group 2), and patients in the neurolept group received anesthesia using thiopental sodium, droperidol, fentanyl, and N2O (Group 3). MEASUREMENTS AND MAIN RESULTS: Recovery was assessed by an observer blinded to the treatment allocation, using a Modified Steward Recovery Score and judgment of orientation and comprehension, collaboration and degree of sedation for the first 4 hours after extubation. Arterial blood gases were measured 30 minutes after extubation. A questionnaire regarding the degree of perioperative amnesia was presented to the patients 4 and 24 hours after surgery. The recovery scores were better in the TIVA group with reversal than in the other two groups from 0 to 30 minutes postoperatively. No difference between the groups could be found thereafter, although after 30 minutes some resedation occurred in the TIVA group with reversal. The median injected amount of flumazenil in Group 1 was 0.5 mg. Respiratory depression (breathing frequency below 10 breaths/min) was reversed with naloxone in one patient in the TIVA group with reversal, five patients in the TIVA group without reversal, and no patient in the neurolept group (p < 0.001). On blood gas analysis, there was no evidence of hypoxemia or carbon dioxide retention. No difference was seen between the groups regarding consumption of analgesics, degree of amnesia, or patient rating of the quality of anesthesia. One patient in Group 2, however, recorded awareness at skin incision when questioned 4 hours after the operation, but could not recall this 20 hours later. CONCLUSIONS: TIVA with midazolam and alfentanil can be used for major gynecologic surgery. Recovery in the neurolept group was equal to recovery in the TIVA group without reversal, and flumazenil improves the recovery after midazolam anesthesia. Overall, in comparison with the neurolept technique no major advantage could be demonstrated using TIVA with midazolam-alfentanil.

Adult↗
PubMed1995

A comparison of propofol and isoflurane anaesthesia: the need for ephedrine and glycopyrrolate.

Sixty patients, ASA I-III, presenting for elective colonic surgery were studied to assess the stability of blood pressure and heart rate during anaesthesia with three equally potent anaesthetic techniques. Patients in group I (n = 20) received thiopentone induction, isoflurane and nitrous oxide; patients in group II (n = 20) received total intravenous anaesthesia with propofol; and patients in group III (n = 20) received intravenous propofol supplemented with nitrous oxide. Fentanyl and vecuronium were used in all three groups. The depth of anaesthesia was judged on clinical signs of adequate anaesthesia. Episodes of bradycardia (heart rate < 50 beats min-1), tachycardia (heart rate > 90 beats min-1), hypotension (mean arterial pressure > or = 30% below pre-operative blood pressure) or hypertension (mean arterial pressure > 30%, or systolic blood pressure > 15 mmHg, above pre-operative value) were recorded when lasting > 5 min. Any use of ephedrine or glycopyrrolate given to correct hypotension or bradycardia was documented: In group II, significantly more patients were given ephedrine (P < 0.01) to treat hypotension. The drug was administered after intubation but before skin incision in the majority of cases (9/11). Glycopyrrolate was given to significantly more patients in group III (P < 0.025) to treat bradycardia, and in 21 of a total of 34 patients given glycopyrrolate it was administered before surgery. With the use of these additional drugs, there were no differences in the number of patients with 5 min episodes of hypotension, hypertension, tachycardia or bradycardia.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1994

Propofol induces changes in the cytosolic free calcium concentration and the cytoskeletal organization of cultured human glial cells and primary embryonic rat brain cells.

BACKGROUND: The site of action of the intravenous anesthetic drug propofol is uncertain. Therefore, we examined the effects of propofol on the cytosolic free calcium levels of cultured primary embryonic rat brain cells (80-85% neurons), and on the organization of the cytoskeleton in these rat cells and in a model system of cultured human glial cells (astrocytes). METHODS: Propofol was added to the cells as the clinically available solution Diprivan. Cytosolic free calcium changes in neurons were studied using Fura2 and a single-cell microfluorometric method. Fluorescence microscopy was used to study the organization of actin filaments and tubulin in detergent-extracted cells. RESULTS: An increase in the cytosolic free calcium concentration of 116 +/- 39 nM was seen shortly after the addition of 0.3 microgram.ml-1 propofol, and a propofol concentration of 0.03 microgram.ml-1 resulted in an increase in cytosolic free calcium concentration of the same magnitude, 119 +/- 42 nM. Most of the calcium (60-75%) came from the extracellular environment, and the rest was from intracellular stores. When neurons were depleted of intracellular calcium by 1,2-bis-5-methyl-amino-phenoxylethane-N,N'-tetra-acetoxymethyla cetate (MAPT/AM), no changes were seen in the actin organization of the cytoskeleton. Actin organization was affected by all concentrations of propofol, 0.3-50 micrograms.ml-1 (1.7-280 microM), when exposure to the drug was achieved by a 30-min incubation. After the incubation, the exposed cells were more rounded and exhibited increased ruffling activity, both at the periphery and on the cellular surface, and ring-shaped actin structures were also seen. These effects were concentration dependent and reversible, and reached a maximum after 20 min of incubation. Propofol had no apparent effect on the organization of tubulin. CONCLUSIONS: Propofol induced changes in the cytoskeletal organization of actin in cultured rat neurons and human glial cells. These changes must have been due to the increase in intracellular calcium seen shortly after the addition of propofol, since no effects on actin organization were seen when intracellular calcium was depleted.

Actins↗
PubMed1993

Staphylococcus aureus meningitis. A review of 104 nationwide, consecutive cases.

METHODS: Based on a nationwide registration, the clinical and bacteriologic data from 61 postoperative and 43 hematogenous cases of Staphylococcus aureus meningitis in Denmark from 1986 through 1989 were reviewed. RESULTS: Postoperative meningitis was a foreign body infection in 89% of the cases and had a lower mortality (18% [11/61]) compared with hematogenous meningitis (56% [24/43]). Hematogenous S aureus meningitis seems to be part of an overwhelming, disseminated infection as indicated by the following: 81% of the patients had bacteremia, 21% had endocarditis, and 12% had osteomyelitis. Most patients were older, often with underlying diseases, community-acquired infections, and a clinical picture of severe meningitis. The major findings were mental status changes and a high rate (34%) of focal neurological changes. The initial leukocyte count in the cerebrospinal fluid sample was low, and the bacteria were seen in Gram's stain smears in 40% of cases only. The prognosis was related to the age of the patients and the initial antibiotic treatment. Patients treated with penicillinase-stable penicillins in combination with fusidic acid may have a better prognosis. Three (12%) of 25 surviving patients had severe sequelae. CONCLUSIONS: Hematogenous S aureus meningitis is a severe disease with a high mortality related to age, presence of shock, and infection with strains of phage type 95.

Adolescent↗
PubMed1993

Genotoxicity testing of the herbicide Roundup and its active ingredient glyphosate isopropylamine using the mouse bone marrow micronucleus test, Salmonella mutagenicity test, and Allium anaphase-telophase test.

The genotoxic potential of the herbicide Roundup and its active agent, glyphosate isopropylamine salt, was studied in three different assays. No clastogenic effects were found in the mouse bone marrow micronucleus test for either of the two agents. In the Salmonella assay only Roundup was tested. It showed a weak mutagenic effect for the concentrations 360 micrograms/plate in TA98 (without S9) and 720 micrograms/plate in TA100 (with S9). These concentrations are close to the toxic level. The anaphase-telophase Allium test showed no effect for the glyphosate isopropylamine salt, but a significant increase in chromosome aberrations appeared after treatment with Roundup at concentrations of 1.44 and 2.88 mg/l when calculated as glyphosate isopropylamine. The most frequent aberrations observed could be characterized as disturbances of the spindle.

Allium↗
PubMed1993

Propofol decreases random and chemotactic stimulated locomotion of human neutrophils in vitro.

We have studied the influence of clinical concentrations of propofol (2,6-diisopropyl phenol), emulsified propofol (Diprivan) and the emulsifier of propofol (Intralipid 10%) on random and chemotactic locomotion of human polymorphonuclear leucocytes in an agarose assay. Random locomotion was decreased (P < 0.001) to a similar extent by the three drugs. Concentrations of propofol 2.5 micrograms ml-1 and greater, and of Diprivan 3.33 micrograms ml-1 and greater, also reduced chemotaxis (P < 0.05) against both zymosan-activated human serum (C5a) and N-formyl-methionyl-leucylphenylalanine (FMLP), used as chemoattractants. Intralipid reduced chemotaxis towards C5a but not towards FMLP. We conclude that propofol in clinically relevant concentrations may adversely affect leucocyte locomotion in vitro.

Adult↗