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Biomedical subjects

P Jameson

Publications and source records attributed to P Jameson.

At least 19 recordsLinked to original sources
PubMed2000

Defining dimensions of pregnancy intendedness.

BACKGROUND: The classification scheme used by the National Survey of Family Growth (NSFG) is a well-established system for defining the intendedness of pregnancy, but its clinical relevance is uncertain. The purpose of this study was to explore how women conceptualize the intention status of their pregnancies and how their concepts relate to the classification scheme used by the NSFG. METHODS: This qualitative study used in-depth, semistructured, open-ended interviews with 27 pregnant women seeking prenatal care or abortion. Sampling was based on ethnicity (Caucasian or Hispanic), education, religiosity, and NSFG intention status (intended, mistimed, or unwanted). RESULTS: Five qualitative dimensions of pregnancy intendedness emerged: preconception desire for pregnancy, steps taken to prepare for pregnancy, fertility behavior and expectations, postconception desire for pregnancy, and adaptation to pregnancy and baby. The relationship of these qualitative dimensions to the NSFG categories was varied and complex, particularly for the NSFG mistimed category. Women indicated that their partners had a strong influence on preconception and postconception desire for pregnancy. CONCLUSION: Further research is needed to develop measures of pregnancy intendedness that accurately reflect the needs and priorities of women. Research that addresses male perspectives and influence is of particular importance.

Abortion, Induced↗
PubMed1999

Exploring the concepts of intended, planned, and wanted pregnancy.

BACKGROUND: A variety of terms have been used to define the intention status of pregnancies. The purpose of this study was to explore how women relate to these terms and how they define the intention status of their pregnancies. Improved understanding of how women use these terms may enhance communication between physicians, patients, and families. METHODS: This qualitative study used in-depth semistructured interviews to explore how women defined the intention status of current, past, and hypothetical pregnancies. Eighteen women who were seeking prenatal care, elective abortion, or pregnancy testing were interviewed. Most of the subjects were interviewed in the first trimester of a current pregnancy. Four researchers independently reviewed the interview transcripts and summarized the points made by each subject. RESULTS: Three major themes emerged from the interviews: (1) definitions of terms related to pregnancy varied substantially among women and seemed to be highly correlated to social and cultural influences; (2) the concepts of wanted and unwanted pregnancy were qualitatively distinct from the concepts of planned and unplanned pregnancies and seemed to be more relevant to the decision to continue or abort the pregnancy; and (3) attitudes of the male partners toward the pregnancies were very influential in how women defined their pregnancies. CONCLUSIONS: Physicians should explore the attitudes and circumstances of pregnant women, rather than focusing on whether the pregnancy was planned. Support from the significant other and the woman's underlying values about parenthood seem to be of particular importance. Our results also suggest that further studies are needed to determine the best method for measuring the intention status of pregnancy for research and policy.

Adolescent↗
PubMed1997

The effect of cortisol suppression on interleukin-6 and white blood cell responses to surgery.

BACKGROUND: The endocrine and immune changes associated with surgery are well documented, but the interaction between them has not been fully evaluated. Cortisol production during surgery can be suppressed by etomidate and we have used this to investigate the relationship between the cortisol response and immune changes in the perioperative period. METHODS: We have measured the cortisol, interleukin-6 and white cell responses to elective abdominal hysterectomy in 8 healthy female patients, who received etomidate 0.3 mg kg-1 for induction of anaesthesia. A control group of 8 subjects received thiopentone. Both groups of patients received vecuronium and fentanyl 2 micrograms kg-1 and anaesthesia was maintained with nitrous oxide in oxygen and isoflurane 0.5-1.0%. Venous blood samples were collected before and during surgery and up to 24 h in the postoperative period. RESULTS: Serum interleukin-6 values were significantly greater at 6 and 12 h (P < 0.05) in those patients who received etomidate. Inhibition of the serum cortisol response to surgery in the etomidate group was also associated with less marked lymphopenia at 4 h (P < 0.05). There was no significant difference in neutrophil granulocyte counts between the two groups. CONCLUSION: In conclusion, endogenous corticosteroids modulate the interleukin-6 response to surgery.

Adult↗
PubMed1996

Injection pain with propofol. Reduction with aspiration of blood.

A randomised, controlled, single-blind study was performed on 100 patients to investigate a new method of reducing pain on propofol injection. Aspiration of 2 ml of the patient's blood into a syringe of propofol immediately before injection was compared with the addition of lignocaine 20 mg or normal saline 2 ml to the propofol before injection. The addition of blood was significantly more effective in reducing pain on injection than the addition of saline (p < 0.001), but was not significantly more effective than the addition of lignocaine.

Adult↗
PubMed1995

Prevalence of Bartonella henselae antibodies in pet cats throughout regions of North America.

Cat exposure has been directly associated with the development of human Bartonella henselae infections, resulting in cat-scratch disease, bacillary angiomatosis, or bacteremia. The prevalence of serum antibody titers to B. henselae was determined for selected pet cats from 33 geographic locations throughout the United States and several areas in western Canada. Seroprevalences paralleled increasing climatic warmth (P < .02) and annual precipitation (P < .03). These warm, humid areas with the highest seroprevalence would also have the highest number of potential arthropod vectors. The southeastern United States, Hawaii, coastal California, the Pacific Northwest, and the south central plains had the highest average prevalences (54.6%, 47.4%, 40.0%, 34.3%, and 36.7%, respectively). Alaska, the Rocky Mountain-Great Plains region, and the Midwest had low average prevalences (5.0%, 3.7%, and 6.7%, respectively). Overall, 27.9% (175/628) of the cats tested were seropositive. The seroprevalence of B. henselae in cats varies throughout the United States and appears to be influenced by climate.

Animals↗
PubMed1995

Differentiation of Bartonella-like isolates at the species level by PCR-restriction fragment length polymorphism in the citrate synthase gene.

The citrate synthase gene (gltA) of Bartonella henselae was cloned and sequenced to compare genetic divergence among alpha and gamma branches of the class Proteobacteria and to develop enhanced genotypic reagents for B. henselae identification. B. henselae gltA is 1,293 nucleotides in length and 63 to 66% homologous with corresponding gene sequences of Rickettsia prowazekii, Escherichia coli, and Coxiella burnetii. The observed genetic variability suggests that gltA sequences can provide a useful means for studying moderate divergence among related bacteria. Oligonucleotides specific for B. henselae gltA were evaluated for the ability to prime PCR amplification within the alpha and gamma branches of the proteobacteria. Under the conditions used, only B. henselae, Bartonella quintana, and R. prowazekii template DNAs yielded amplification products (approximately 380 bp). DNAs from 28 Bartonella-like isolates of feline origin were amplified by B. henselae primers and analyzed for restriction fragment length polymorphism. The resulting patterns for all 28 isolates were similar or identical to that of the recognized B. henselae strain. Current studies are aimed at optimization of PCR conditions for specificity and sensitivity of amplification of Bartonella sequences from clinical isolates.

Amino Acid Sequence↗
PubMed1984

Markedly enhanced production of gamma interferon in murine T lymphocytes treated with lentil lectin and the diterpene ester, mezerein.

Gamma interferon (IFN-gamma) was induced in murine splenocytes first stimulated to grow by concanavalin A (Con A) and subsequently treated for 3 h with the diterpene ester, mezerein (MZN) and then with lectin from Lens culinaris for 24 h. Yields as high as 60,000 u/ml were obtained in cells from either male or female, random-bred, white Swiss mice or inbred C67B1/6 mice. Antibody to Thy 1.2 surface antigen completely obliterated the mouse gamma interferon (MuIFN-gamma) response, whereas anti-Lyt 1.2 and anti-Lyt 2.2 each destroyed a portion of the lymphocyte population responsible for MuIFN-gamma production. Kinetic analysis of production and release showed that IFN was detectable in culture fluids within 4 h after treatment with very little IFN remaining cell-associated (less than 10%). A simple, rapid, and economical two-step purification procedure involving ammonium sulfate fractionation and yeast RNA affinity chromatography resulted in as much as 770-fold purification to achieve specific activities greater than 10(7) u/mg protein. The purified MuIFN-gamma was shown to be predominantly acid-labile, inactivated by sodium dodecyl sulfate (SDS), and neutralized by antiserum to MuIFN-gamma. Approximately 10% of the MuIFN-gamma was acid-stable and SDS-resistant, but was still neutralized by anti-MuIFN-gamma serum. Two molecular weight peaks of about 40 and 20 kD were demonstrated by SDS-polyacrylamide gel electrophoresis. Isoelectric focusing in polyacrylamide slab gels gave a relatively heterogeneous band of activity between pH 5.5 and 6.5. The mechanism by which the combination treatment described enhances MuIFN-gamma production so markedly remains unknown, but the degree of enhancement is greater than additive.

Animals↗
PubMed1983

Inhibition of feline leukemia virus replication by human leukocyte interferon.

The replication of feline leukemia virus (FeLV) is inhibited by treatment of cat cell cultures with crude human leukocyte interferon (HuIFN-alpha) as evidenced by titration of the infectious progeny. The inhibition can be demonstrated in three different cell lines in which the production of hemagglutinin by encephalomyocarditis (EMC) virus, and plaque formation by vesicular stomatitis virus (VSV) are also inhibited by the HuIFN-alpha. The dose dependency of the inhibition of EMC virus by the HuIFN-alpha is similar to that obtained with feline interferon in each of the three cell lines. VSV and EMC virus are less than 10 times more sensitive than FeLV to the inhibitory action of HuIFN-alpha if responses to a single interferon treatment are compared for each of the viruses tested in the most sensitive cell line, FEA. The interferon effect on FeLV is more pronounced when it is added within one day after the inoculation of the cells rather than applied before cell infection. The induction of focus formation by FeLV can also be inhibited by HuIFN-alpha in cat cells (CCC-81) which contain the murine sarcoma virus genome.

Animals↗
PubMed1979

Production of interferon by human tumor cell lines.

Fourteen continuous human cell lines, including nine derived from tumors and five from non-neoplastic tissues, produced interferon in response to induction with bluetongue virus (BTV), Newcastle disease virus (NDV), and poly(I) . poly(C) complexed with DEAE-dextran. The seven best interferon-producing cell lines (one from a melanoma, five derived from carcinomas, and one SV40-virus-transformed kidney cell line) responded to at least one of the viral inducers with yields of interferon over 1000 units/ml. Because the HT-1376 bladder carcinoma cell line produced high yields of interferon in this survey, and is easily propagated, the optimal conditions for interferon production were investigated, using BTV as the inducer. Interferon yields in 59 inductions over a period of about two years consistently fell within a 6-fold range, and had a geometric mean titer of about 2700 reference units (RU)/ml, representing the production of about 3 RU/10(3) cells. This yield is comparable to mean titers of 1 to 10 RU/10(3) cells obtained by others with human leukocytes, foreskin cell strains, or the Namalva lymphoblastoid cell line. UV-inactivated BTV at a multiplicity corresponding to 10 PFU/cell was as effective an inducer in the HT-1376 cell line as the fully infectious virus at a multiplicity of 1 PFU/cell. The interferon produced by the HT-1376 epithelial cell line has characteristics similar to the interferon induced by poly(I) . poly(C) in human diploid fibroblasts. These studies clearly demonstrate that many different types of tumor-derived cells have the capacity to produce interferon, and that some equal or surpass the efficiency of diploid cells.

Bluetongue virus↗
PubMed1978

Thermal and vortical stability of purified human fibroblast interferon.

The loss of biological activity upon heating or agitation of human interferons is markedly altered by changing their aqueous environment. Low pH significantly stabilizes liquid fibroblast interferon at 68 degrees C and 37 degrees C whereas chaotropic salts stabilize at 68 degrees C but not at 37 degrees C; this anomalous result may be due to reactivation of biological activity at the higher temperature. The concentration of extraneous proteins influences the apparent thermal stability at any temperature and pH; thus, interferon was not stable even at low pH at protein concentrations less than 5 microgram/ml. Solutions of partially purified fibroblast interferon can be inactivated by mechanical stress; the addition of proteins or nonionic detergents prevents such inactivation. Freeze-dried preparations show the greatest thermal stability. The use of high-temperature, accelerated storage tests makes it possible to predict the shelf-life of freeze-dried interferon.

Drug Stability↗
PubMed1978

Production of interferon in human cell cultures by a new, potent viral inducer.

A new discovered double-stranded RNA inducer of interferon, bluetongue virus (BTV), stimulates the production of large amounts of interferon in animals as well as in many types of mammalian cell cultures, including human leukocytes, and continuous cell lines. The exceptional pH lability of BTV and its lack of pathogenicity for man further recommend its use as an interferon inducer. Among several human cell lines tested, the most efficient producer of interferon was a continuous cell line designated HT-1376, derived from a bladder carcinoma. With infectious BTV as the inducer, the HT-1376 line produced more interferon per cell than did leukocytes; interferon yields ranged from 10,000 to 60,000 units per ml of crude, unconcentrated supernatant fluid. Noninfectious BTV, inactivated by ultraviolet irradiation, was as effective as infectious virions. The interferon produced in HT-1376 cells has physicochemical and antigenic properties resembling those of fibroblast interferon produced in diploid cells.

Bluetongue virus↗