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Biomedical subjects

L Jensen

Publications and source records attributed to L Jensen.

At least 127 records · Page 7Linked to original sources
PubMed1989

Arginine vasopressin, but not corticotropin releasing factor, is a potent stimulator of adrenocorticotropic hormone following electroconvulsive treatment.

Neuroendocrine responses to the hypothalamic pituitary-adrenal axis following electroconvulsive treatment (ECT) were evaluated in twelve depressed (6 males/6 females) patients. Plasma concentrations of arginine vasopressin (AVP), corticotropin releasing factor (CRF), corticotropin (ACTH), and cortisol were measured using radioimmunological methods at four different ECT occasions. At each occasion plasma samples were taken immediately before ECT, at the recovery of spontaneous breathing and at 10 and 30 minutes after the ECT. No changes were observed in the plasma CRF concentrations. A large and rapid increase in plasma AVP concentrations was seen after the ECTs. This was followed by increased plasma ACTH and plasma cortisol levels. It is generally believed that AVP exerts a modulatory potentiating action on the CRF-induced ACTH release. The present results demonstrate that AVP per se can cause a release of ACTH from the anterior pituitary.

Adrenocorticotropic Hormone↗
PubMed1989

Long-term functional analysis of the ileoanal reservoir.

Since November 1980, 180 patients underwent abdominal colectomy, rectal mucosectomy, ileoanal reservoir construction, and ileoanal anastomosis at the authors' institutions. One hundred twenty-nine patients had restoration of intestinal continuity before the end of 1986. One hundred fourteen of these patients (88 percent) were available for follow-up at a mean length of time of 5.0 years from ileostomy closure (range, 16 to 88 months). The mean number of pouch evacuations was 5.4 +/- 2.5 during the day (range, 1 to 12) and 1.5 +/- 1.0 at night (range, 0 to 6). Ninety-one percent of patients reported perfect or almost perfect daytime continence, and 74 percent found this true at night. Sixty-three percent of patients believed their pouch function continued to improve over many years. Ninety-five percent of patients questioned would choose an ileoanal reservoir again instead of a permanent ileostomy. This long-term assessment of the function of the ileoanal reservoir confirms that it is a viable, although not perfect, option in the management of ulcerative colitis and familial adenomatous polyposis.

Activities of Daily Living↗
PubMed1989

Ileal pouch vaginal fistulas: incidence, etiology, and management.

Some of the initial problems associated with the ileoanal reservoir have been solved. In their place, other complications have been recognized. Among these, the ileal pouch vaginal fistula stands out as a recently recognized difficult management problem. This multicenter study was undertaken to gain insight into the causes for, and treatment of, pouch vaginal fistulas. Cases were gathered from 11 surgical practices throughout North America, in which the ileoanal reservoir procedure is frequently performed. Overall, 304 females had undergone ileoanal reservoir procedures by these surgical groups. Twenty-one patients developed 22 pouch vaginal fistulas for an overall incidence of 6.9 percent. Five additional patients with pouch vaginal fistulas, whose restorative proctocolectomies were done elsewhere, were referred to these surgeons for treatment. The courses of these 26 patients form the basis of this report. This study details the risk factors which predispose in the development of a pouch vaginal fistula, as well as the various treatment options available.

Adolescent↗
PubMed1989

Cytomegalovirus and legionella species as the cause of liver enzyme elevations in haemodialysis patients.

We conclude that reinfection or recurrent infection with CMV or legionella may be responsible for serum glutamic-pyruvic transaminase (SGPT) elevations in up to one fourth of haemodialysis patients. Since NANB infection or asymptomatic coinfection with these agents cannot be discounted with certainty, it seems prudent to maintain haemodialysis patients with abnormal liver-function tests on Body Fluid Precautions, even if they remain asymptomatic.

Alanine Transaminase↗
PubMed1989

Use of deoxyribonucleic acid probes in the identification of cell origin and detection of cellular contamination in human lymphoblastoid cell lines.

Established lymphoblastoid cell lines have provided a valuable reference source for studying neoplastic lymphoproliferative disorders in humans. However, two major problems are associated with the establishment and growth of these cell lines: (a) the established cell line may not represent the original neoplastic clone, and (b) contamination of the established cell line with the other cell lines may occur. Lymphoblastoid cell lines "W" and "SP5" were established from splenectomy specimens of two patients with hairy cell leukemia. Both cell lines displayed B cell characteristics by immunophenotypic and Ig gene rearrangement studies. The banding patterns of the rearranged Ig genes (heavy and light chains) in the W cell line were different and in the SP5 cell line were identical with the corresponding untransformed splenic cell lines, indicating that cell line SP5 did and cell line W did not represent the original neoplastic clone. Continuous cultures of some of the subclones derived from cell line W and SP5 led to the growth of the cell lines W15T, W17T, and SP5T which all demonstrated T cell features based on immunophenotypic and T cell receptor rearrangement studies. However, the T cell receptor alpha and beta rearranged bands as well as bands generated by hybridization with highly polymorphic DNA probes p YNH24 and 0-3315-32 in these three lines and a human T cell leukemia line (CEM), were identical indicating that W15T, W17T and SP5T cell lines were contaminated with CEM. Studies of gene establishment patterns and DNA polymorphisms by Southern blotting are effective methods to establish clonal identity and to rule out cellular contamination in lymphoblastoid cell lines.

B-Lymphocytes↗
PubMed1988

Antibodies from patients and mice with autoimmune diseases react with recombinant hnRNP core protein A1.

Sera from autoimmune patients and normal volunteers were tested for antibodies to the A1 core protein of heteronuclear ribonucleoprotein (hnRNP) particles by ELISA and Western blot assays. The A1 protein used in these studies was produced by recombinant DNA technology. Thirty-seven per cent of patients with systemic lupus erythematosus produced anti-A1 antibodies, compared to 7% of normal controls. Several strains of autoimmune mice were also analysed. They spontaneously made high-titered responses to A1. Normal strains showed very low anti-A1 response unless they were specifically immunized with the antigen. Following immunization, normal mice also made high-titered responses to the A1 protein. These studies demonstrated that the A1 protein itself is an autoantigenic component of hnRNP particles. Our studies uncovered no evidence of linkage between the production of anti-A1 and of anti-DNA antibodies.

Animals↗
PubMed1988

A reduced rate of bulky DNA adduct removal is coincident with differentiation of human neuroblastoma cells induced by nerve growth factor.

Human SY5Y neuroblastoma cells which were differentiated in culture by treatment with 7S murine nerve growth factor for 5 weeks and selection with aphidicolin (L. Jensen, Dev. Biol. 120:56-64, 1987) demonstrated a considerably slower rate of removal of DNA adducts of benzo[a]pyrene, benzo[a]pyrenediolepoxide, and N7-methylguanine than did undifferentiated mitotic cells. A dramatic decline in unscheduled DNA synthesis induced by UV radiation was similarly observed. DNA polymerase beta and uracil DNA glycosylase were unchanged after differentiation, DNA polymerase alpha and DNA methylase decreased roughly threefold, and total apurinic-apyrimidinic endonuclease activity increased roughly threefold after treatment.

Aphidicolin↗
PubMed1988

Attitudes toward homosexuality: a cross cultural analysis of predictors.

An accepting attitude toward homosexuality was studied in Spain, England, and Germany using samples of 2160, 1167, and 1296 respectively rendering a total sample size of 4623. A multiple regression analysis was used to demonstrate that approval of homosexuality could be predicted from basic demographics, family background, religious and political values. A causal model is introduced with demographic and family variables thought to first influence religion and political values and that these values would then directly impact on the acceptance of the belief that homosexuality can be justified.

Attitude↗
PubMed1988

The effects of acute and life-long food restriction on basal and stress-induced serum corticosterone levels in young and aged rats.

The effects of short term (1-month) and life-long 60% ad libitum food restriction on the adrenocortical response to restraint stress were compared in young and aged Fischer 344 rats. In rats restricted for 1 month (study 1), the adrenocortical response differed as a function of age. In 8-month-old animals, the initial steep rise in corticosterone in response to stress was of similar magnitude in ad libitum and restricted animals. In 23-month-old animals the corticosterone response was severely blunted in restricted animals. In life-long restricted animals (study 2), the corticosterone response to restraint stress was tested at 8, 16, and 24 months of age. The general pattern of response to stress in these animals was similar to that in study 1. The 16- and 24-month-old animals showed the same blunted response to stress found in the 23-month-old animals restricted for only 1 month, suggesting that the severe restriction per se and not life-long food restriction blunted the response to stress in aged animals. The similarity between the response to stress in study 1 and study 2 was evident even though animals were tested in one case before feeding when corticosterone levels were high, and in the other 4-5 h after feeding when corticosterone levels were lower. In study 3 it was found that in food-restricted young rats, the mean corticosterone level over a 24-h period was significantly elevated above that in ad libitum fed young rats. In aged rats, however, except before daily feeding, corticosterone levels of food-restricted rats remained significantly below those of ad libitum fed animals, whose levels were, in turn, significantly elevated compared to those of ad libitum fed young rats. These findings suggest that in aged animals severe food restriction reduces basal corticosterone levels, adrenal responsiveness to stress, and adrenal size and has the potential to protect against the consequences of high corticosterone levels in aging.

Adrenal Cortex↗
PubMed1987

The new immigration: implications for poverty and public assistance utilization.

Central to the controversy over the new immigration is the worry that it has promoted an increase in the level of poverty and welfare utilization among immigrants. This study documents and explains immigrant-native trends and differentials in poverty and public assistance utilization during the period from 1960-1980. Results show that there is ample evidence that the level of poverty among immigrants, particularly recent immigrants, increased over the 1960-1980 period. However, there was little indication of a commensurate rise in the propensity of families to receive public assistance. There is also little evidence of a disproportionate and increasing burden of immigrants on public assistance coffers as the new immigration proceeds. Recent immigrants are no more likely to receive welfare than otherwise comparable natives. Regarding average annual public assistance income among welfare families, the empirical results suggest that immigrants differ little from natives in their degree of utilization. Like immigrants of previous waves, the new immigrants appear to be industrious and able to capitalize on their labor force potential to keep them out of poverty. This conclusion derives from findings that 1) in both the tabular and multivariate context, multiple earners kept a greater % of immigrant than native families out of poverty, and 2) immigrants showed a relative disinclination to use welfare as an income maintenance strategy. Still, the decline over time in ameliorative impact of multiple earners should be a source of concern. Also central to the concern over the new immigration is the increasing prevalence of nonwhites among immigrant cohorts. The sizable Hispanic component of the new immigration is particularly controversial. Among the most consistent findings of this study is the apparent deterioration in the economic status of white immigrants and the noticeable lack of any similar deterioration among Hispanic families. For example, among all the groups studied, recent white immigrants registered the largest increases in poverty over time. Poverty among recent Hispanic immigrants did not increase as sharply. Also, Hispanics became increasingly reluctant to use public assistance income whereas recent white immigrants did not, and revealed an increase in mean annual welfare receipt not nearly as great as that for white and Asian families. Admittedly, rates of poverty and public assistance receipt continue to be greater among Hispanics than whites. Still, changes over time reveal a marked deterioration among whites but no such deterioration among Hispanics.

Acculturation↗
PubMed1986

Anionic glycerophospholipids in platelets from alcoholics.

Studies on ethanol-exposed animals have revealed changes in anionic phospholipids in brain membranes. The intention of this study was to investigate whether there was a similar effect on man. Assuming platelets to be an adequate model for CNS synaptosomes, concentration and fatty acid composition of anionic phospholipids, phosphatidylserine (PS) and phosphatidylositol (PI) in the platelet membrane from alcoholics after a debauche period were examined and compared to controls. Ethanol effects on neutral lipids were also analysed in order to obtain a comprehensive view. No quantitative difference was found in anionic phospholipids between alcoholics and controls. Fatty acid composition of individual phospholipids revealed significant changes which were more obvious in neutral phospholipids than in anionic. Oleic acid was increased and linoleic and arachidonic acids were decreased. After 1 week of detoxification, the abnormalities did not decrease, on the contrary they increased and total phospholipid concentration per platelet was significantly higher than in controls. It is concluded that the ethanol toxicity on bone marrow hampers the use of platelets as a model for synaptosomes but that the observed lipid abnormalities might play a major role in the impairment of platelet function in alcoholics.

Adult↗
PubMed1986

Enzymatic wound cleaning and absorbable sutures. An experimental study on Varidase and Dexon sutures.

The effect of an enzymatic preparation for wound cleaning (Varidase) on the mechanical properties of absorbable sutures (Dexon) was studied in vitro and in vivo in a rat model. In vitro the sutures demonstrated a significant decrease in strength (breaking strength and energy absorption) and extensibility after 12 days of incubation in saline. Incubation in Varidase, however, further decreased the mechanical properties significantly. The stiffness of the sutures was independent of treatment and time. In vivo changes of mechanical properties of the sutures resemble those of the in vitro study, except for a decrease in stiffness of the sutures. The sutures in a primary closed wound had the same strength (energy absorption) as the sutures of an open wound treated by saline, while the sutures of an open wound treated by Varidase tended to have a decreased strength (p = 0.08). This study supports the hypothesis that an enzymatic process may be involved in the degradation of Dexon. The continuous use of Varidase in Dexon-sutured wounds for a period longer than a few days is, therefore, questioned.

Animals↗
PubMed1986

The effect of maternal employment on adolescent daughters.

This report considers the question of the effects of maternal employment on adolescents. The frequently cited conclusion that there is "no difference between the adolescents of employed and nonemployed mothers" is considered inaccurate. It is argued that failure to find differences between these two groups does not mean that there are no differences. Comparisons of personal relationships within the family context showed that daughters of nonemployed mothers had a closer relationship with their fathers, perceived them as happier and more friendly, and experienced less anger and tension in the home.

Adolescent↗
PubMed1985

Sequences outside of the long terminal repeat determine the lymphomogenic potential of Rous-associated virus type 1.

Recombinant avian leukosis viruses have been constructed from the molecularly cloned DNAs of Rous-associated virus type 1 (RAV-1) and Rous-associated virus type 0(RAV-0). Virus encoded by the cloned RAV-1 DNA induced a high incidence of B-cell lymphoma and a moderate incidence of a variety of other neoplasms. Virus encoded by the cloned RAV-0 DNA did not cause disease. Virus recovered from DNA constructions that encoded the gag, pol, and 5' env sequences of RAV-0 and the 3' env and long terminal repeat sequences of RAV-1 did not cause a high incidence of lymphoma. Rather, these constructed viruses induced a low incidence of a variety of neoplasms. Virus recovered from reconstructed pRAV-1 DNA had the same disease potential as did virus recovered from the parental pRAV-1 DNA. These results indicate that the long terminal repeat sequences of RAV-1 do not confer the potential to induce a high incidence of B-cell lymphoma.

Animals↗
PubMed1985

Meiotic exchange within and between chromosomes requires a common Rec function in Saccharomyces cerevisiae.

We used haploid yeast cells that express both the MATa and MAT alpha mating-type alleles and contain the spo13-1 mutation to characterize meiotic recombination within single, unpaired chromosomes in Rec+ and Rec- Saccharomyces cerevisiae. In Rec+ haploids, as in diploids, intrachromosomal recombination in the ribosomal DNA was detected in 2 to 6% of meiotic divisions, and most events were unequal reciprocal sister chromatid exchange (SCE). By contrast, intrachromosomal recombination between duplicated copies of the his4 locus occurred in approximately 30% of haploid meiotic divisions, a frequency much higher than that reported in diploids; only about one-half of the events were unequal reciprocal SCE. The spo11-1 mutation, which virtually eliminates meiotic exchange between homologs in diploid meiosis, reduced the frequency of intrachromosomal recombination in both the ribosomal DNA and the his4 duplication during meiosis by 10- to greater than 50-fold. This Rec- mutation affected all forms of recombination within chromosomes: unequal reciprocal SCE, reciprocal intrachromatid exchange, and gene conversion. Intrachromosomal recombination in spo11-1 haploids was restored by transformation with a plasmid containing the wild-type SPO11 gene. Mitotic intrachromosomal recombination frequencies were unaffected by spo11-1. This is the first demonstration of a gene product required for recombination between homologs as well as recombination within chromosomes during meiosis.

Chromosomes↗