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At least 19 recordsLinked to original sources
PubMed1991

Factors affecting treatment decisions for a life-threatening illness: the case of medical treatment of breast cancer.

Despite notions that patients are now playing a more proactive role in directing their own health care, our study of breast cancer patients considering adjuvant therapy indicates that, at least for a life-threatening illness, patients still rely heavily on their physicians to make treatment decisions. Out of 100 patients, 80.0% accepted their physician's primary treatment recommendation. Using behavioral decision-making theory we examined why some patients chose to disregard the physician's treatment recommendation despite its importance within the decision-making process. The discriminant function analysis performed to examine the factors influencing acceptance or rejection of a physician's treatment recommendation identified two sets of factors. Factors related to the amount and specificity of information about treatments conveyed to the patients, and the strength of the treatment recommendation itself. Patients who did not accept their physician's treatment recommendation were told in more specific terms what the benefits of treatment would be; they also rated side effects of treatment to be more probable and more severe than patients who did concur with the physician's treatment recommendation. These patients also rated their physicians' treatment recommendations as less strong than other physicians'. Nonacceptor patients were also better educated and were more likely to be risk takers. This study supports the findings of other studies that patients want more specific disease and treatment information, but suggests that the provision of this information might lead to therapy decisions which diverge from physicians' recommendations.

Breast Neoplasms↗
PubMed1976

An investigation of the effects of the intrauterine contraceptive device based on a longitudinal study of a self-selected sample of Barbadian women.

The results of longitudinal study of a self-selected sample of 1,790 Barbadian women who accepted the intrauterine contraceptive device (IUD) as their method of contraception are reported. The accumulated experience of 44,000 woman months of IUD use is presented. The demographic, medical, and obstetric data on admission for 2,797 IUD acceptors and 4,296 nonacceptors are contrasted. The reproductive experience of the two groups prior to the insertion of an IUD with respect to live births, stillbirths, and miscarriages is similar while the incidence of ectopic pregnancy is shown to be different. The association between the IUD and the incidence of tubal pregnancy is evaluated, and the literature dealing with this topic is reviewed. Estimates of the relative risk of an ectopic pregnancy in a woman with an IUD in utero are given.

Abortion, Spontaneous↗
PubMed1991

Differences between Asn-Xaa-Thr-containing peptides: a comparison of solution conformation and substrate behavior with oligosaccharyltransferase.

A series of tripeptides that satisfy the -Asn-Xaa-Thr/Ser- primary sequence requirement [Marshall, R. D. (1972) Annu. Rev. Biochem. 41, 673-702] for N-glycosylation have been synthesized and examined as potential acceptors in an oligosaccharyltransferase assay. Of these, six (Ac-Asn-Ala-Thr-NH2, Ac-Asn-Leu-Thr-NH2, Ac-Asn-Asp-Thr-NH2, Ac-Asn-D-Ala-Thr-NH2, Ac-Asn-Pro-Thr-NH2, and Ac-Asn-AIB-Thr-NH2) were examined for solution conformational properties in dimethyl sulfoxide with use of amide proton temperature coefficients, 3JHN alpha analysis [Pardi, A., et al. (1984) J. Mol. Biol. 180, 741-751], and 2-D ROESY experiments [Bothner-By, A. A., et al. (1984) J. Am. Chem. Soc. 106, 811-813]. The analysis reveals that the peptides that serve as acceptors in the transferase assay demonstrate similar conformational properties in solution. These are highlighted by a secondary structural motif that involves the interaction between the asparagine side-chain carboxamide and the backbone amide of the threonine. The peptides that show very poor acceptor, or even nonacceptor, properties in the oligosaccharyltransferase assay demonstrate different conformational features in solution. These observations may explain the distinct biological activity observed for these peptides.

Amino Acid Sequence↗
PubMed1989

Structural requirements for protein N-glycosylation. Influence of acceptor peptides on cotranslational glycosylation of yeast invertase and site-directed mutagenesis around a sequon sequence.

To understand better the structural requirements of the protein moiety important for N-glycosylation, we have examined the influence of proline residues with respect to their position around the consensus sequence (or sequon) Asn-Xaa-Ser/Thr. In the first part of the paper, experiments are described using a cell-free translation/glycosylation system from reticulocytes supplemented with dog pancreas microsomes to test the ability of potential acceptor peptides to interfere with glycosylation of nascent yeast invertase chains. It was found that peptides, being acceptors for oligosaccharide transferase in vitro, inhibit cotranslational glycosylation, whereas nonacceptors have no effect. Acceptor peptides do not abolish translocation of nascent chains into the endoplasmic reticulum. Results obtained with proline-containing peptides are compatible with the notion that a proline residue in an N-terminal position of a potential glycosylation site does not interfere with glycosylation, whereas in the position Xaa or at the C-terminal of the sequon, proline prevents and does not favour oligosaccharide transfer, respectively. This statement was further substantiated by in vivo studies using site-directed mutagenesis to introduce a proline residue at the C-terminal of a selected glycosylation site of invertase. Expression of this mutation in three different systems, in yeast cells, frog oocytes and by cell-free translation/glycosylation in reticulocytes supplemented with dog pancreas microsomes, leads to an inhibition of glycosylation with both qualitative and quantitative differences. This may indicate that host specific factors also contribute to glycosylation.

Amino Acid Sequence↗
PubMed1991

Peptide binding by protein disulfide isomerase, a resident protein of the endoplasmic reticulum lumen.

Previously we had demonstrated by photoaffinity labeling that a 57-kDa protein of the endoplasmic reticulum can bind and become covalently linked to glycosylatable photoreactive peptides containing the sequence-Asn-Xaa-Ser/Thr-. Subsequently, it was found that this protein, called glycosylation site-binding protein, was a multifunctional protein, i.e. it was identical to protein disulfide isomerase (PDI), the beta-subunit of prolyl hydroxylase and thyroid hormone-binding protein. In this study, the peptide specificity for binding to this 57-kDa protein, hereafter called PDI, has been investigated in more detail using photoaffinity probes. The results reveal that although N-glycosylation by oligosaccharyl transferase in the endoplasmic reticulum has an absolute requirement for an hydroxyamino acid in the third amino acid residue of the glycosylation site sequence, no such specificity is observed in the binding of such peptides to PDI. In addition to the lack of specificity for an hydroxyamino acid in the third residue position, no specificity was observed for the asparagine residue in the first position. Thus, binding is not restricted to peptides containing N-glycosylation sites. We have investigated the discrepancy between this apparent lack of sequence specificity and earlier results indicating that binding of peptides to PDI was specific for N-glycosylation site sequences. We now demonstrate that PDI in the lumen of microsomes is more efficiently labeled by peptides containing photoreactive-Asn-Xaa-Ser/Thr- sequences than by nonacceptor site sequences because the former become glycosylated. This increased labeling does not occur because the glycosylated form of the probes are preferentially recognized by PDI. Rather, it appears that increased polarity of the affinity probe after attachment of the oligosaccharide chain prevents its exit from the sealed microsomes, in effect concentrating it within the lumen of the microsome. These results, coupled with other studies on the multifunctional nature of PDI, suggest that the observed peptide binding may be a manifestation of the ability of PDI to recognize the backbone of polypeptides in the lumen of the endoplasmic reticulum.

Affinity Labels↗
PubMed1985

Active site-directed photoaffinity labeling and partial characterization of oligosaccharyltransferase.

Oligosaccharyltransferase, the enzyme that catalyzes the transfer of the oligosaccharide chain of dolichol-P-P-GlcNAc2Man9Glc3 to asparagine residues in -Asn-X-Thr/Ser- sites within polypeptides, has been radiolabeled using a photoactivatable azido tripeptide acceptor, N alpha-[3H]Ac-Asn-Lys(N epsilon-p-azidobenzoyl)-Thr-NH2. As determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, the molecular mass of the oligosaccharyltransferase polypeptide from hen oviduct microsomes is 60 kDa. Radiolabeling of the 60-kDa polypeptide was completely dependent upon photolysis of hen oviduct endoplasmic reticulum preparations in the presence of the azido peptide and Mn2+, which is required for enzymatic activity. Labeling of the enzyme was not inhibited in the presence of a 10-fold excess of the nonacceptor peptides, unacetylated Asn-Lys(N epsilon-p-azidobenzoyl)-Thr-NH2 or unacetylated Asn-Leu-Thr-NH2, whereas it was completely abolished by the presence of a 10-fold excess of the competing acceptor peptide, N alpha-Bz-Asn-Leu-Thr-NH2. Thermal inactivation of oligosaccharyltransferase was achieved by heating endoplasmic reticulum preparations to 60 degrees C. This loss of enzyme activity at 60 degrees C paralleled a comparable decrease in radiolabeling of the 60-kDa polypeptide, whereas temperatures of 50 degrees C and lower had no effect on either process. Oligosaccharyltransferase itself may be an N-linked glycoprotein, because the 60-kDa radiolabeled polypeptide binds to concanavalin A-agarose and is susceptible to digestion by beta-endohexosaminidase H.

Affinity Labels↗
PubMed1986

Acceptance of contraceptive practice by grandmultiparae in Benin City, Nigeria.

Five hundred sixty grandmultiparous women were interviewed as to their contraceptive awareness, desirability and use in the three major hospitals in Benin City, Nigeria, between October 1, 1980 and September, 1981. Their parity ranged from 5 to 14 with a mean of 6.7. There was high level of awareness of contraceptive availability and usefulness (65%), but low level of practice (27.1%). The main causes of the low practice level included opposition from husband and other relatives, complications of previous methods used and the desire to have a large family. Oral contraceptives were the preferred method, followed by intrauterine devices. Educational attainment had a positive relationship to acceptance of contraceptive practice. We believe that with more concerted effort at family planning counseling, the community will be rid of the hazards and menace of grandmultiparity.

Adolescent↗
PubMed1988

Problems and help seeking in high-risk adolescent patients of health clinics.

In this study, 2787 adolescents between the ages of 13 and 18 years living in inner-city communities were interviewed about their mental and physical health and their clinic use. The patients used consolidated mental and physical health clinics located in neighborhoods, hospitals, or schools; or traditional neighborhood or hospital health clinics. Analyses of selected patient problems reveal that less than one third of adolescent patients with suicide ideation, conduct disorder, and substance abuse or dependency sought or received care for those problems. Only half of the adolescents with major depression sought or received care for depression, and only two thirds of the sexually active females sought or received help with birth control. A special effort needs to be made to attract troubled youth to clinics and to identify and treat their problems, particularly when those problems involve mental health concerns.

Adolescent↗
PubMed1986

A study of women requesting interval contraceptive sterilization who do and do not return for surgery.

With the use of initial records of 1128 women who presented for interval tubal ligation, characteristics of those who were sterilized were juxtaposed with characteristics of those who did not return for surgery. Follow-up telephone interviews were conducted to explore regret after sterilization among 268 sterilized women. The subsequent histories of 144 women who did not return for surgery were examined, to determine whether failure to return might have screened, selectively, the women at greatest risk of regret. High levels of subsequent unwanted conception and pregnancy wastage were found in the nonreturn group. Institutional factors were often implicated in failure to return. Variables available at initial presentation are proposed to identify women who risk adverse consequences of postponed sterilization, to facilitate return without increasing regret.

Adult↗
PubMed1991

Breast cancer risk and oral contraceptive use: results from a large case-control study.

The association between oral contraceptive use and breast cancer risk was examined using data from a case-control study of breast cancer in Long Island, New York. Cases were defined as female residents of Nassau and Suffolk Counties between the ages of 20 and 79, diagnosed with breast cancer between January 1, 1984 and December 31, 1986. Age- and county-matched controls were selected from driver's license files. Among all women under age 70 at diagnosis, there was no association between oral contraceptive use and breast cancer; there was, however, a positive association in the subgroup ages 20-49 (adjusted odds ratio = 1.68, 95% CI: 1.16-2.42). Risk increased with increasing duration of use, but did not differ between women who first used oral contraceptives before the first pregnancy and those who first used them later, or between women who first used oral contraceptives before age 25 and those who first used them at a later age. Risk also appeared to increase with number of years of use before the first pregnancy or before age 25, although numbers were small. History of benign breast disease did not influence risk. The association of breast cancer risk with oral contraceptive use appeared stronger in women from Suffolk County than Nassau County.

Adult↗
PubMed1989

Reasons for non-use of family planning methods at Ilorin, Nigeria: male opposition and fear of methods.

This study reports the main reasons given for non-use of contraception by non-pregnant women aged 15-44 years, who are at risk of unplanned pregnancy and living in the Ilorin Local Government Area of Kwara State, Nigeria. Six hundred and forty-six women were derived from a stratified cluster sample and interviewed using a questionnaire. Almost one-third (31.4%) of respondents gave male opposition to family planning as the reason for current non-use. Another 13.3% expressed fear of methods, 6.3% did not want to use contraception until the first child was born, and 13.6% until the desired number of children were born. Sociodemographic variables including age, educational level, religion, and residence as reasons for non-use were reported. Other important findings included a high awareness of, low availability of, or poor accessibility to contraceptive methods. Short and long term intervention strategies using information, education and communication materials are proposed to combat low levels of contraceptive use in this area.

Adolescent↗
PubMed1986

Utilization of health services by Mexican immigrant women in San Diego.

The limited empirical data available on maternal health problems among Mexican immigrant women in the United States suggest that they underutilize health services, especially general preventive care. Research conducted among legal and undocumented women in the Mexican immigrant population in San Diego, California, support these findings. Among undocumented mothers, 11.5% of their births in the U.S. occurred with no prenatal care or care sought in the third trimester, which is much higher than Mexican women legally in the country (3.6%) and the general San Diego maternal population (3.8%). When we examine births which occurred within the last five years by immigration status, we find that women legally in the country have a much higher rate of cesarean delivery of both undocumented women and women in the general San Diego maternal population. Undocumented women in our sample were much less likely than their legal counterparts to return for postpartum examinations for themselves, to seek neonatal care for their infants, and to have had Pap examinations or carry out breast self-examinations.

California↗
PubMed1992

Teenage conception and contraception in the English regions.

Nationally available data on teenage fertility, family planning care and mortality were analysed to determine the relationship between teenage conception, availability of abortion and family planning care, and an indicator of socioeconomic disadvantage--the Standardized Mortality Ratio (SMR). In the 14 regions of England the strongest correlate of teenage conception and of the proportion of teenage conceptions aborted was female all-causes SMR. High levels of provision of NHS abortion services and uptake of family planning clinic care did not significantly reduce teenage fertility. Provision of traditional family planning services obviously plays an important role in preventing teenage pregnancy, but innovation in this service coupled with a concerted effort to reduce social disadvantage might have a greater impact on teenage fertility in England.

Abortion, Induced↗