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Biomedical subjects

K Olsen

Publications and source records attributed to K Olsen.

At least 73 records · Page 4Linked to original sources

Chronic Vietnam PTSD and acute civilian PTSD. A comparison of treatment experiences.

Many types of external trauma have been linked to the genesis of posttraumatic stress disorder (PTSD) and yet recent reports have focused almost exclusively on PTSD occurring in the Vietnam veteran (PTSD/veteran). The extent to which treatment experiences with PTSD/veteran can be generalized to other traumatized patients, for example, acute civilian populations, has not been investigated. Clinical observations comparing PTSD precipitated by a motor vehicle accident with PTSD/veteran suggested there were major differences between these two groups on the following variables: source of referral, age, sex, socioeconomic level, nature of stressor, timing of the stressor, character of the intrusive and avoidance symptoms, and treatment noncompliance behavior. These differences were of sufficient magnitude to call into question the feasibility, at this time, of constructing generalizations regarding PTSD utilizing only the PTSD/veteran population.

Adaptation, Psychological↗

Influence of the gel-liquid phase transition on hematoporphyrin triplet deactivation in liposomes.

The deactivation of the triplet state of hematoporphyrin and its dimethyl ester in unilamellar liposomes of dipalmitoyl phosphatidylcholine was studied by nanosecond laser flash photolysis. It was found that the rate of deactivation increases abruptly on raising the temperature in the region of the gel-liquid phase transition of the lipid bilayer (41 degrees C). The rate of change has its maximum at 38.4 +/- 0.5 degree C for both porphyrins. This variation is due to the high lateral mobility of the porphyrins in the liquid-crystal bilayer, which enhances the rates of concentration triplet quenching and triplet-triplet annihilation.

1,2-Dipalmitoylphosphatidylcholine↗

Tissue plasminogen activator treatment of postoperative intraocular fibrin.

Intraocular recombinant tissue-type plasminogen activator was used for treatment of postoperative intraocular fibrin clots. Using a rabbit vitrectomy and cyclocryotherapy model of postoperative fibrin, rabbits were randomized on the first postoperative day to receive either an anterior chamber injection of lactated Ringer's solution or 25,000, 50,000, or 100,000 IU tissue plasminogen activator (tPA). An intraocular dose of 25,000 IU of tPA produced marked resolution of the fibrin clot 24 hours later. A 50,000 and 100,000 IU dose produced slightly more resolution of the fibrin. No ophthalmoscopic or histologic evidence of intraocular toxicity was seen.

Animals↗

A new technique for subchoroidal implantation of experimental malignant melanoma.

A new technique for implanting Greene hamster amelanotic melanoma cells into the rabbit eye is described. The technique involves the deposition of a tumor fragment into the subchoroidal space via a transvitreal approach. Thirty rabbit eyes were implanted with 26 successful tumor growths producing solitary choroidal nodules. This technique offers the advantages of rapid implantation, the ability to precisely choose the site of implantation including posterior sites, and eliminates the need for a large scleral incision.

Animals↗

Pharmacokinetics and plasma bactericidal activity of aztreonam in low-birth-weight infants.

Aztreonam (30 mg/kg) was administered intravenously every 12 h during week 1 and every 8 h during weeks 2 to 4 of life to 26 low-birth-weight (less than 2,000 g) infants, and plasma concentration-time curves were measured on two occasions. The pharmacokinetics were described equally well by one-compartment and noncompartment models, and the values on day 1 were similar to those measured during the steady state on days 3 to 6. The mean peak plasma concentrations at completion of the 10-min infusion were from 65 to 83 micrograms/ml, the higher concentrations being seen in the larger infants. The half-lives of aztreonam ranged from 5.4 to 8.6 h and did not change significantly with birth weight. The median peak and trough plasma bactericidal titer against a strain of Escherichia coli (MBC, 10 micrograms/ml) was 1:16. Against a strain of Pseudomonas aeruginosa (MBC, 16 micrograms/ml), the median peak and trough bactericidal titers were 1:8 to 1:16 and 1:4, respectively. The urinary concentrations of aztreonam on day 1 of therapy were from 24 to 460.7 micrograms/ml (mean +/- 1 standard deviation, 254 +/- 113 micrograms/ml).

Aztreonam↗

Lentivirus genomic organization: the complete nucleotide sequence of the env gene region of equine infectious anemia virus.

The nucleotide sequence of the envelope (env) gene region of equine infectious anemia virus (EIAV), a member of the lentivirus subfamily of retroviruses, has been determined from a clone of integrated proviral DNA for which the gag and pol sequences have been reported previously. The env gene is 859 codons in length and the sequence reported here is consistent with the published biochemical properties of EIAV glycoproteins. The env gene region of EIAV shares considerable structural similarities but negligible sequence homologies with the env genes of other members of the lentivirus subfamily, visna virus, and human T-lymphotropic virus (HTLV-III) or lymphadenopathy virus (LAV). As in visna virus and HTLV-III, the polymerase (pol) and env genes of EIAV do not overlap. EIAV contains two short open reading frames (orf) of 50 and 66 codons in the pol-env intergenic region. However, unlike the orf Q regions reported for visna virus and HTLV-III, neither EIAV orf overlaps the 3' terminus of the adjacent pol gene. The EIAV genome also contains a third short open reading frame of 135 codons which is contained completely within the env gene, in contrast to the 3'-orf/orf F gene reported for HTLV-III/LAV which extends beyond the env gene terminus. These results provide a detailed description of the env gene region of EIAV and describe a number of characteristic features of genomic organization in lentiviruses which contrast with the genomic organization of oncogenic retroviruses.

Amino Acid Sequence↗

Metaphit, an acylating ligand for phencyclidine receptors: characterization of in vivo actions in the rat.

Metaphit, which acylates phencyclidine (PCP) receptors in vitro, was shown to acylate PCP receptors and antagonize the behavioral and electrophysiological effects of PCP in vivo. Metaphit (2 mumol/rat) administered i.c.v. produced PCP-like stereotyped behavior and ataxia in 10 to 20% of rats. At a lower dose, Metaphit (1 mumol/rat) antagonized the ability of PCP to induce stereotyped behavior and ataxia for 3 and 4 days, respectively. The Metaphit-induced antagonism of PCP induction of stereotyped behavior and ataxia was dose-dependent and specific as Metaphit did not antagonize induction of stereotyped behavior by amphetamine. Further evidence for a specific PCP receptor mechanism was the finding that PCP pretreatment blocked the effects of subsequent Metaphit administration. Metaphit also antagonized PCP-induction of stereotyped behavior, but not ataxia, after i.v. administration. Doses of Metaphit that produced long-term antagonism of the behavioral effects of PCP also produced a significant decrease in the maximum binding, but not Kd, of the binding of the PCP analog, [3H]-1-(2-thienyl)cyclohexyl]piperidine, in Metaphit-pretreated rats. The binding of [3H]etorphine and [3H]spiroperidol was not altered significantly by pretreating rats with Metaphit. (-)-Cyclazocine and (+)-SKF 10,047 induced stereotyped behavior and ataxia that was not antagonized by Metaphit-pretreatment. In electrophysiological experiments, Metaphit, like PCP, initially depressed the firing of caudate neurons as does PCP, but then irreversibly inhibited PCP-induced depression of caudate neurons. These results suggest that metaphit antagonized the effects of PCP by selectively acylating PCP receptors and that (-)-cyclazocine- and (+)-SKF 10,047-induced behavioral effects are not mediated primarily by PCP receptors.

Acylation↗

Pharmacokinetics and bactericidal activity of sultamicillin in infants and children.

The pharmacokinetics of sultamicillin and ampicillin suspensions were studied in 20 infants and children 8 months to 69 months of age (mean age, 27 months). Mean peak plasma concentrations of ampicillin and sulbactam occurred at 90 minutes after administration of 42.5 mg of sultamicillin (25 mg of ampicillin/kg and 17.5 mg of sulbactam/kg) per kg to fasting and non-fasting patients. Co-administration of milk usually resulted in higher concentrations of ampicillin and sulbactam, however, the differences in the AUC values between the fasting and fed groups were not statistically significant. Sultamicillin and ampicillin were administered in cross-over fashion to ten children. Plasma concentrations of ampicillin after 42.5 mg of sultamicillin per kg were greater at 20, 40, and 60 min than those after 25 mg of ampicillin per kg alone and the AUC was 39% larger in subjects who received sultamicillin than in those who received ampicillin. Plasma bactericidal activity against a non-beta-lactamase producing Haemophilus influenzae strain was similar for children who were given sultamicillin or ampicillin. Against a beta-lactamase-producing Haemophilus strain the median bactericidal titres were 1:8 at 40, 60 and 90 min after sultamicillin and less than 1:2 at the same intervals after ampicillin.

Ampicillin↗

Bacteriological efficacy of nafcillin and vancomycin alone or combined with rifampicin or amikacin in experimental meningitis due to methicillin-susceptible or -resistant Staphylococcus aureus.

The pharmacokinetics and bacteriological efficacy of nafcillin (NFPC), vancomycin (VCM), amikacin (AMK) and rifampicin (RFP) alone and in VCM combinations were evaluated in the experimental rabbit meningitis caused by methicillin-susceptible Staphylococcus aureus (MSSA) or methicillin-resistant Staphylococcus aureus (MRSA). The mean concentrations of NFPC, VCM, AMK and RFP in cerebrospinal fluid (CSF) with MSSA meningitis exceeded the minimal bactericidal concentrations of MSSA during 8 hours therapy period. The mean CSF penetration rates of the 4 drugs during therapy were from 1% to 26% which are comparable to those observed in humans with meningitis. The median CSF bactericidal titers of RFP, VCM plus RFP, AMK, VCM plus AMK regimens were larger than 1:8 during therapy of MSSA meningitis study. In experimental MRSA meningitis, RFP and VCM plus RFP achieved titers greater than 1: 16 during therapy and at 24 hours. No statistically significant reduction in the CSF bacterial colony count was obtained with any of the antibiotic regimens in MSSA meningitis. By contrast, in 8 hours MRSA meningitis model, significant reductions in the number of MRSA were observed in animals treated for 8 hours with VCM plus RFP (P less than 0.01), RFP (P less than 0.05), and NFPC plus RFP (P less than 0.01).

Amikacin↗

Neisseria gonorrhoeae conjunctivitis. An outbreak during an epidemic of acute hemorrhagic conjunctivitis.

Ten patients with gonococcal conjunctivitis were examined during an epidemic of acute hemorrhagic conjunctivitis (AHC). Eye cultures in all cases demonstrated Neisseria gonorrhoeae, and seven also had isolates of N gonorrhoeae in genital specimens. All patients responded well to antimicrobial therapy. The patients had used a folk remedy in which they had applied urine to their eyes to treat the symptoms of AHC.

Acute Disease↗

Pharmacology of ketoconazole suspension in infants and children.

The pharmacokinetics of ketoconazole administered as either a commercially prepared suspension or as a crushed tablet in applesauce were studied in 12 children. The mean peak plasma concentration of ketoconazole and the area under the plasma time-concentration curve were approximately twofold greater with the suspension than with the crushed tablets.

Biological Availability↗