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Biomedical subjects

K Olson

Publications and source records attributed to K Olson.

At least 73 records · Page 4Linked to original sources
PubMed1989

Ultrasound surveillance of the cervix during pregnancy in diethylstilbestrol-exposed offspring.

Twenty-three diethylstilbestrol (DES)-exposed patients were evaluated through 27 pregnancies to determine their eligibility for admission to a prospective protocol that combined serial ultrasound surveillance of the lower uterine segment-cervical complex with periodic pelvic examinations to diagnose cervical incompetency. Of these, 21 pregnant women, including seven vaginectomy patients, were matched to 84 low-risk controls to determine the following: 1) the effect of DES exposure on reproductive performance, 2) the efficacy of ultrasound selection of cerclage candidates, and 3) the influence of previous partial vaginectomy on reproductive outcome. Five DES-exposed patients were diagnosed as having cervical incompetency and had cerclages placed. There were no missed diagnoses of cervical incompetency. The DES-exposed patients delivered statistically earlier in gestation than did controls (268 +/- 13 versus 276 +/- 10 days). It was not evident that this difference was important clinically, as there were no neonatal deaths, very low birth weight infants, second-trimester losses, or deliveries before 252 days (36 weeks) among the study patients. Previous vaginectomy did not affect the frequency of the diagnosis of cervical failure or the neonatal outcome. After ultrasound surveillance and treatment for incompetent cervix, a majority of our patients delivered at term without cerclage placement. Therefore, routine cerclage placement is not recommended. Knowledge of the ultrasound criteria for diagnosing cervical incompetency is required.

Adult↗
PubMed1987

Human immunodeficiency virus (HIV) infection in brains with AIDS-related leukoencephalopathy.

In addition to central nervous system (CNS) opportunistic infections and neoplasms, patients with acquired immunodeficiency syndrome (AIDS) develop unexplained dementia and encephalopathy and degeneration of the white matter. We studied autopsied brains from 20 adult patients who expired from AIDS to determine the relationship of human immunodeficiency virus (HIV) infection to white matter lesions and to clinical findings. In four patients with dementia/encephalopathy and abnormalities of the white matter, there was evidence of HIV infection as shown by in situ hybridization. In contrast, the remaining 16 patients who had no evidence of white matter degeneration revealed no hybridization to the HIV probe. The cells infected with HIV included endothelial cells, perivascular macrophages/monocytes, and multinucleated giant cells and were found in or adjacent to white matter degeneration. These results demonstrate a correlation between HIV-infected cells and AIDS leukoencephalopathy and provide further evidence for HIV-related dementia/encephalopathy.

Acquired Immunodeficiency Syndrome↗
PubMed1986

Hyperthermia associated with drug intoxication.

Hyperthermia (temperature of at least 40.5 degrees C for at least one hour) associated with drug intoxication was identified in 12 patients over a 5-yr period. Intoxication was due to anticholinergic drugs (tricyclic antidepressants, antipsychotics, antihistamines), CNS stimulants (phencyclidine, cocaine, 3,4-methylene dioxyamphetamine, mescaline, lysergic acid diethylamide), salicylates, or combinations of these. Hyperthermia was present in four patients on admission, but its onset was delayed up to 12 h in the remainder. Outcome of hyperthermic patients was poor: five died and four had severe permanent neurologic sequelae. Clinical signs common to patients who developed hyperthermia were increased muscular activity and absence of sweating. Five patients suffered seizures, and four did not respond to anticonvulsant medication until body temperature was lowered. Cooling did not appear to favorably affect the outcome after body temperature had remained above 40.5 degrees C for a prolonged period. Prevention of death or neurologic sequelae from drug-induced hyperthermia depends upon the recognition of risk factors and the prompt treatment of hyperthermia.

Adolescent↗
PubMed1985

Genetic and antigenic variations among geographical isolates of Sindbis virus.

The genetic and antigenic variation in 12 Sindbis (SIN) virus isolates from four zoogeographic regions (Paleoarctic, Ethiopian, Oriental and Australian) has been examined at a molecular level. RNase T1 oligonucleotide fingerprinting of genomic RNA from SIN isolates revealed that the primary structure of the RNA from viruses from each zoogeographic region was unique. The E1 and E2 glycoproteins and the capsid protein of two isolates from each zoogeographic region were compared by tryptic peptide mapping with the Egyptian prototype strain AR-339. Tryptic peptide maps of viruses from Sicily and the Ethiopian region were similar to those of the prototype; maps of isolates from the Oriental and Australia regions were different from each other and from those of the prototype strain. Viruses from each of the four zoogeographic regions were analysed antigenically by neutralization with polyclonal serum to AR-339 and by enzyme-linked immunosorbent assay with an anti-E2 monoclonal AR-339 antibody. Clear antigenic divergence of SIN isolates into two groups, representing the Paleoartic-Ethiopian and Oriental-Australian regions were demonstrated. These results support a hypothesis which proposes that ancestral SIN virus diverged into two distinct groups. The genetic changes have resulted in further phenotypic divergence within the geographic varieties.

Amino Acid Sequence↗
PubMed1985

Pharmacokinetics and bactericidal activity of cefuroxime axetil.

The pharmacokinetics of cefuroxime axetil were studied in 10 adult volunteers aged 24 to 31 years (mean age, 27), 22 infants and children aged 11 to 68 months (mean age, 33 months), and 11 children aged 7 years, 7 months to 12 years, 3 months (mean age, 11 years, 1 month). Mean peak plasma concentrations of cefuroxime occurred between 90 and 120 min in all study patients and were independent of the fasting or feeding status. The areas under the concentration-time curves were significantly higher in adult volunteers who received cefuroxime axetil with milk than in those who received the drug while fasting or with applesauce. The bioavailability of cefuroxime axetil was significantly enhanced in children by the concomitant ingestion of cefuroxime axetil and infant formula or whole milk. The areas under the concentration-time curves were 25 to 88% higher when cefuroxime axetil and milk were administered simultaneously than when the same dose was given to all fasting patients. The plasma bactericidal activities of cefuroxime against beta-lactamase-positive and -negative strains of Haemophilus influenzae and Staphylococcus aureus at the time of peak plasma concentrations were independent of feeding status and were similar in adults and in children. Against these strains, 52% of the children and 38% of the adults had peak bactericidal levels of 1:8 or greater.

Adult↗
PubMed1984

Opposite effects of Met-enkephalin and Leu-enkephalin on a discriminated shock-escape task.

Leu-enkephalin was found to impair and Met-enkephalin to enhance acquisition of a discriminated Y-maze shock-escape task in mice at equivalent doses (100 micrograms/kg, ip). Naloxone (1.0 and 10.0 mg/kg) also enhanced acquisition of the escape response and blocked the impairing actions of Leu-enkephalin. Neither naloxone nor the enkephalins influenced shock-induced locomotor activity in an open field. The results suggest that enkephalin actions on escape conditioning are mediated through opioid receptors.

Animals↗
PubMed1983

Introduction of cloned human papillomavirus genomes into mouse cells and expression at the RNA level.

The entire DNA genomes of five different human papillomaviruses (HPVs) were cloned into the BamHI site of pBR322 (HPV-1a, HPV-3, HPV-4, and HPV-9) or the EcoRI site of pBR325 (HPV-2), using as starting materials virus preparations isolated from papillomas of individual patients. Under stringent hybridization conditions (Tm-28 degrees), the five cloned HPVs exhibited less than 10% homology with one another. To establish model cell systems that may be useful for the identification of HPV genes and HPV gene products, mouse thymidine kinase negative (tk-) cells were cotransformed to the tk+ phenotype with the herpesvirus thymidine kinase gene and each of the five HPV cloned DNAs (either as intact recombinants or excised HPV DNA without removal of pBR). In most tk+ cell clones, a complex pattern of multiple high molecular weight inserts of HPV DNA were present in high copy number. Most of the HPV DNA sequences in the cotransformed cells were not present as unit-length episomal viral DNA. Analyses of the integration pattern (DNA blot) and RNA expression (RNA blot) of several HPV-1a and HPV-3 transformed cell lines suggest that some copies of the viral genome are integrated in a similar manner in different cell lines leading to the expression of identical viral RNA-containing species. Two of the cell lines transformed by the intact HPV-1a/pBR322 recombinant synthesized substantial amounts of four discrete viral polyadenylated cytoplasmic RNA species of 1.9, 3.2, 3.8, and 4.5 kb. Two cell lines transformed by the intact HPV-3/pBR322 recombinant synthesized 4-5 polyadenylated cytoplasmic viral RNA species ranging from 0.8 to 4.6 kb. The analysis shows that each viral RNA species appears to be a hybrid RNA molecule containing both HPV and pBR322 sequences. Based on these findings and the molecular organization of the HPV-1a genome (O. Danos, M. Katinka, and M. Yaniv (1982). EMBO J. 1, 231-237), it is possible that transcription of each of the HPV-1a RNA species is initiated using the HPV early promoter and terminated in pBR322.

Animals↗
PubMed1983

Auditory evoked responses, impedance measures, and diagnostic speech audiometry in severe head injury.

Three case studies are presented to illustrate the clinical usefulness of serial electrophysiologic and behavioral audiologic assessments in describing CNS function in severe head injury. There was an association among acute auditory brain stem and middle-latency evoked response findings, computed tomography of brain abnormality and neurologic status, and rate of recovery. Auditory evoked response findings 4 days after injury were also correlated with long-term outcome of diagnostic speech audiometry.

Acoustic Impedance Tests↗
PubMed1982

Identification of serious hearing loss with acoustic reflex data. Clinical experience with some new guidelines.

The acoustic stapedial reflex was activated by a broad-band noise signal for 326 adult subjects. Two groups were formed on the basis of pure-tone audiometry findings. Two hundred and four subjects were normal hearers or showed, at most, a mild hearing loss with a pure-tone average (500, 1000, 2000, and 4000 Hz) of less than 35 dB HL. One hundred and twenty-two subjects showed a serious hearing sensitivity impairment with a pure-tone average of 35 dB HL or greater. These acoustic reflex data were then applied prospectively in the identification of hearing impairment. Hearing sensitivity status was accurately differentiated in over three-fourths of the population. Serious hearing loss was invariably found for subjects with acoustic reflex threshold levels equal to or greater than 110 dB SPL, whereas it was effectively ruled-out by acoustic reflex thresholds in the 60 through 80 dB SPL range. The proportion of subjects with clinically significant hearing impairment is described for intermediate acoustic reflex threshold levels. These guidelines are offered as a feasible first step in clinical differentiation of hearing sensitivity status.

Adult↗