PubMed Health⌕ Search

Biomedical subjects

L Erickson

Publications and source records attributed to L Erickson.

At least 37 records · Page 2Linked to original sources
PubMed1996

Cytogenetic and clinical characteristics of a case involving complete duplication of Xpter-->Xq13.

True isochromosomes for Xp probably do not exist in a liveborn. We describe a rare case of complete Xp duplication and retention of the inactivation centre at Xq13. Cytogenetically, it is described as a nonmosaic 46,X,psu idic(X)(q13). Complete duplication of Xpter-->Xq13 was confirmed by banded analysis and FISH probes for X centromere, Xp21, XIST locus, and whole chromosome paints for X and Y. The abnormal X was always late replicating. Clinically, the patient was short statured, had primary amenorrhoea, and incomplete development of secondary sexual characteristics, but otherwise was phenotypically normal. There are no non-mosaic reported cases with complete duplication of i(Xp) confirmed by FISH or molecular techniques. Those cases with partial duplication of Xp and presence of the inactivation centre share the traits of amenorrhoea and poor secondary sexual development. To develop a clinical profile of duplication of Xp (in presence of Xq13) there is a need to study more cases.

Adult↗
PubMed1996

A moderately repetitive DNA sequence in alfalfa is transcribed in a floral-specific manner.

Based on DNA sequence analysis of 5 clones of repetitive DNA from alfalfa (Medicago sativa), we propose the existence of a dispersed middle repetitive element about 3400 bp long with a copy number in the range of 2-3 x 10(3) per haploid genome. The average A+T content of the sequences was 54.6%, compared with 61.4% for the alfalfa genome. Sequence homologies between overlapping regions of the clones ranged from 85 to 89.5% with an average of 86.6%; sequence divergence was due largely to single base pair changes, with deletions or insertions occurring randomly across sequences. An open reading frame (ORF) in one clone, RPE15, contained homologies to cereal prolamin genes and a legumin box was located upstream of the coding region. A Northern blot of RNA from various alfalfa tissues, probed with the above clone containing this ORF, showed an extensive heterodispersed pattern of hybridization in the late stages of flower bud development but in no other tissues.

Base Composition↗
PubMed1995

The Nebraska "Network of Drug-Free Youth" program.

This paper describes Nebraska's six-year experience with a successful prevention program to form and maintain local drug-free youth groups. More than 4,500 youth were involved at the time of a six-year evaluation survey. Nearly 91% of group members who responded reported being alcohol-free in the previous 30 days and almost all (97%) reported being tobacco-free. Thirty-eight percent of members met one or more of the federal criteria for "high-risk" youth. Sixty-eight percent of responding high-risk youth who previously used alcohol credited group membership with helping them quit or reduce use. The program appears to assist in delaying onset of alcohol, tobacco, and other drug use for youth in the program, and to assist in decreasing or eliminating use of alcohol and tobacco by adolescents who used before participating.

Adolescent↗
PubMed1993

An AT-rich satellite DNA sequence, E180, in alfalfa (Medicago sativa).

A DNA fragment of approximately 750 bp was cloned from EcoRI-digested nuclear DNA of alfalfa (Medicago sativa). Southern blot and sequence analysis showed that the cloned DNA fragment represents a tetramer of a highly tandemly repeated DNA sequence of 185-188 bp (E180). The consensus sequence deduced from the four repeating units is 189 bp in length with an AT content of 67%. The copy number of the satellite DNA was estimated to be approximately 1.8 x 10(5) per genome and constitutes about 1% of the alfalfa genome. Sequence comparison revealed no identity to any repetitive DNA sequences that have been published to date. Digestion with HpaII and MspI indicated a high degree of methylation at the internal C of the restriction site CCGG within E180.

Base Composition↗
PubMed1993

Predicting response to amitriptyline in posttraumatic stress disorder.

OBJECTIVE: This study evaluated the relation between baseline clinical phenomena and response to amitriptyline in patients with posttraumatic stress disorder (PTSD). METHOD: Data were obtained from an 8-week placebo-controlled, double-blind study of combat veterans. Bivariate and multivariate statistics were used to evaluate the relations between the following variables and outcome: age, depression, anxiety, severity of PTSD symptoms, personality, psychiatric comorbidity, level of exposure to trauma, and individual symptoms of depression, anxiety, and traumatic stress. Outcome measures were scores on the Clinical Global Impression scale, Hamilton Rating Scale for Depression, Hamilton Rating Scale for Anxiety, and Impact of Event Scale. RESULTS: Drug response was related to lower baseline levels of depression, neuroticism, combat intensity, anxious mood, impaired concentration, somatic symptoms, feelings of guilt, and one intrusion and four avoidance symptoms of PTSD. CONCLUSIONS: The results demonstrate that response to amitriptyline is related to measures of depression, anxiety, PTSD, personality, and intensity of combat trauma. Similar relationships were not observed in the placebo group, suggesting a specific relationship to the drug.

Amitriptyline↗
PubMed1992

Pentalogy of Cantrell and ectopia cordis, a familial developmental field complex.

The association of sternal fusion defects with various cardiac, diaphragmatic, and anterior body wall defects represents a developmental field complex that includes the Pentalogy of Cantrell and ectopia cordis. No familial cases have been reported previously. We present 3 consecutively born brothers with extensive diaphragmatic defects, 2 who had the Pentalogy of Cantrell. One of the 2 also had ectopia cordis.

Adult↗
PubMed1992

Correlation between levels of immunoglobulins and immune complexes in plasma of C57BL/6 and C57L/J mice infected with MAIDS retrovirus.

Infection with helper-free, defective MAIDS murine leukemia virus (MuLV) caused a rapid polyclonal activation of B cells in 0.75-, 2-, and 6-month-old C57L/J mice (H-2b, Fv-1n/n), similar to that in C57BL/6 mice (H-2b, Fv-1b/b), which was recognized by elevated plasma immunoglobulin concentrations. However, changes in plasma immunoglobulin levels differed in C57BL/J and C57BL/6 mice. In C57L/J mice, infection resulted in a rapid increase in plasma IgM and IgG2a, and the elevation of IgG2a persisted undiminished for 21 weeks. Levels of IgG2b also became slightly elevated, but those of IgG1 and IgG3 were not significantly affected. Plasma of 6 to 7-month-old C57BL/6 mice contained already high levels of IgM (30-40 mg/ml), which persisted undiminished in uninfected mice but decreased progressively in infected mice to 10% of the original concentration during 25 weeks of observation. In C57BL/6 mice, plasma IgG1 and IgG2b as well as IgG2a became similarly elevated after infection but also only transiently. Their levels began to decrease progressively about 10 weeks after infection and fell to far below the maximum concentration observed. The drastic loss of plasma IgM and IgGs observed in C57BL/6 mice during the later stages of MAIDS MuLV infection did not seem to be a consequence of the polyclonal activation of B cells per se but seemed to reflect additional immunological abnormalities arising in infected C57BL/6 but not C57L/J mice. In both mouse strains these changes in plasma Ig levels correlated with the formation of Ig-containing immune complexes that bound to high-affinity, protein-binding ELISA plates in the absence of antigen coating, which may represent unusual forms of self-antigen-antibody complexes.

Animals↗
PubMed1991

A nested set of eight RNAs is formed in macrophages infected with lactate dehydrogenase-elevating virus.

Total RNA was extracted from primary cultures of mouse macrophages isolated from 10-day-old mice 6 to 12 h postinfection with lactate dehydrogenase-elevating virus (LDV). Poly(A)+ RNA was extracted from spleens of 18-h LDV-infected mice. The RNAs were analyzed by Northern (RNA) blot hybridization with a number of LDV-specific cDNAs as probes. A cDNA representing the nucleocapsid protein (VP-1) gene located at the 3' terminus of the viral genome (E. K. Godeny, D. W. Speicher, and M. A. Brinton, Virology 177:768-771, 1990) hybridized to viral genomic RNA of about 13 kb plus seven subgenomic RNAs ranging in size from about 1 to about 3.6 kb. Two other cDNA clones hybridized only to the four or five largest subgenomic RNAs, respectively. In contrast, two cDNAs encoding continuous open reading frames with replicase and zinc finger motifs hybridized only to the genomic RNA. The replicase motif exhibited 75% amino acid identity to that of the 1b protein of equine arteritis virus (EAV) and 44% amino acid identity to those of the 1b proteins of coronaviruses and Berne virus. Combined, the results indicate that LDV replication involves formation of a 3'-coterminal-nested set of mRNAs as observed for coronaviruses and toroviruses as well as for EAV, with which LDV shares many other properties. Overall, LDV, like EAV, possesses a genome organization resembling that of the coronaviruses and toroviruses. However, EAV and LDV differ from the latter in the size of their genomes, virion size and structure, nature of the structural proteins, and symmetry of the nucleocapsids.

Amino Acid Sequence↗
PubMed1990

Paternal inheritance of mitochondria in rapeseed (Brassica napus).

Transfer of a mitochondrially associated plasmid following sexual crosses in Brassica napus rapeseed suggested that paternal mitochondria were being transferred to the cytoplasm of the egg. To examine this possibility further, plants carrying the chloroplast (cp) marker of triazine resistance, but which had lost the plasmid associated with the mitochondria of this cytoplasm, were crossed as females to males carrying the polima cytoplasm. The males carried a nuclear fertility restorer gene on an extra chromosome to overcome the male sterility marker conferred by the mitochondria of this cytoplasm. Approximately 10% of the F1 progeny displayed the male sterility and flower morphology of the male parent. Mitochondrial (mt) DNA from the progeny showed the combined restriction patterns of both parents, but this mt heterogeneity did not continue into subsequent generations. All progeny retained the cp DNA restriction patterns of the maternal plant as well as resistance to the herbicide atrazine. To date, sexually mediated cybrid plants have shown no morphological abnormalities and have maintained their unique combination of cp and mt traits through several sexual generations.

Brassica↗
PubMed1990

A nationwide survey of urinalysis practices of methadone maintenance clinics. Utilization of laboratory services.

The urinalysis practices of 324 methadone maintenance clinics were surveyed by using a brief self-report questionnaire. Results indicated that there was a wide variability in collection practices and utilization of laboratory techniques. The most frequent collection schedules were monthly (40%) and weekly (32%). The most frequent laboratory techniques used for initial screening were thin-layer chromatography and enzyme immunoassay. Confirmatory testing by a second technique was used by 69% of the laboratories. The most popular confirmatory techniques used were thin-layer chromatography, enzyme immunoassay, and gas chromatography-mass spectrometry. The geographic differences in urinalysis practices also were noted. The implications for drug abuse treatment were determined.

Community Health Centers↗
PubMed1987

Effect of biological toxins on gap-junctional intercellular communication in Chinese hamster V79 cells.

Since chemical modulation of gap-junctional intercellular communication has been implicated in several toxicological endpoints, a study to examine the ability of several biological toxins to inhibit this process was undertaken. Eight biological toxins were tested for their ability to inhibit metabolic cooperation, a measure of gap-junctional intercellular communication, in the Chinese V79 cell system. Aplysiatoxin, anhydrodebromoaplysiatoxin and debromoaplysiatoxin showed the strongest ability to inhibit metabolic cooperation while T2-toxin and vomitoxin inhibited metabolic cooperation to a lesser degree. Aflatoxin B1, aflatoxin B2 and palytoxin were inactive in the Chinese V79 system. Palytoxin, which was extremely cytotoxic, might act as a tumor promoter if it induces compensatory hyperplasia in vivo.

Animals↗
PubMed1987

Physiologic and metabolic response to progressive and prolonged exercise in amyotrophic lateral sclerosis.

Physical work capacity in 35 ALS patients and 6 untrained controls was evaluated during progressive bicycle ergometry. In the ALS patients, maximum oxygen consumption (VO2max) and work capacity (Wmax) drop in relation to the decrease in ALS functional score. However, the oxygen cost (ml O2/kpm) of submaximal exercise was significantly increased. Prolonged submaximal exercise tests in six ALS patients and six matched untrained controls indicated that the exercise-induced increase in plasma free fatty acids, beta-hydroxybutyrate, esterified carnitine, and muscle esterified carnitine was significantly retarded in ALS patients.

3-Hydroxybutyric Acid↗
PubMed1987

Isokinetic assessment in ALS.

Three measures of lower extremity function were compared in a homogenous population of ALS patients. Isokinetic dynamometry was shown to be a sensitive tool for change in strength over time. It demonstrated positive correlations with gait velocity as well as other behavioral measures. Manual muscle tests were relatively insensitive and no more reliable than isokinetics. Isokinetics are a useful adjunct in the assessment of ALS.

Equipment Design↗
PubMed1987

Intravenous thyrotropin releasing hormone in amyotrophic lateral sclerosis: autonomic effects.

Heart rate, respiratory rate, systolic and diastolic blood pressure, and oral and skin temperature changes following intravenous administration of TRH occur at lower infusion rates in patients with ALS and bulbar involvement than in patients with ALS without bulbar involvement. This autonomic sensitivity to TRH infusion is characteristic of a more advanced stage of ALS with difficulties in speaking and swallowing. Patients who will be receiving neuropeptides, such as TRH, must be carefully studied to determine whether subclinical bulbar involvement is present. Such patients may require a lower initial dose or dose rate adjustment as well as continual monitoring during neuropeptide administration.

Adult↗
PubMed1984

Cellular and molecular mechanisms of the bone marrow sparing effects of the glucose chloroethylnitrosourea chlorozotocin.

1,(2-Chloroethyl)-3-cyclohexyl-1-nitrosourea (CCNU) and other chloroethylnitrosourea anticancer agents in clinical use produce severe and cumulative bone marrow toxicity. Chlorozotocin, a glucose analogue, has demonstrated reduced hematologic toxicity while retaining full antitumor activity. The biochemical-pharmacologic properties of chlorozotocin and CCNU were compared in human bone marrow. After a 2-hr incubation with a 0.1-mM drug concentration, total cellular uptake of chlorozotocin in whole marrow was 2.47 +/- 0.80 pmole/10(4) cells and was not significantly different compared to the uptake of 1.94 +/- 0.53 pmole/10(4) cells with CCNU. The quantitative alkylation of bone marrow DNA by chlorozotocin, 22.8 +/- 1.2 pmole/mg DNA, was equivalent to that produced by CCNU, 22.9 +/- 0.5 pmole/mg DNA. Bone marrow was separated into 14 fractions by centrifugal elutriation. CCNU uptake was found to be greater than that of chlorozotocin in 3 fractions that were primarily composed of lymphocytes, monocytes, and normoblasts. Chlorozotocin uptake was greater than CCNU in 6 fractions that contained primarily mature and immature myeloid cells as well as the highest CFU-GM activity. The two drugs produced a comparable degree of DNA strand breakage and DNA-protein cross-linking as measured by alkaline elution of pooled fractions of elutriated bone marrow. DNA interstrand crosslinking was not found with either drug. The most significant finding of this study is the differences in the site of drug alkylation by chlorozotocin and CCNU in bone marrow chromatin. Endonuclease digestions with MCN, DNase I, and DNase II showed nonrandom alkylation of specific regions of chromatin by the two drugs: CCNU demonstrated a preferential binding to the transcriptionally active regions of chromatin, whereas chlorozotocin predominantly alkylated the transcriptionally inactive regions. These data suggest that the lethal damage of nitrosourea alkylation in human bone marrow is principally expressed in transcriptionally active regions of chromatin.

Antineoplastic Agents↗