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Biomedical subjects

S M Wilson

Publications and source records attributed to S M Wilson.

191 records · Page 11Linked to original sources
PubMedDate not supplied

Distribution of progesterone and its effect on human blood during storage.

Human blood, drawn into ACD, was stored under blood bank conditions with and without addition of tritium-labeled progesterone. At selected storage intervals, several biochemical and biophysical parameters were assayed and the distribution of the hormone between plasma and erythrocytes was determined. The retention of the radioactive material by erythrocytes was studied by repeated washes and isotonic saline. The results indicate that erythrocytes stored with addition of progesterone have higher ATP levels, less spontaneous lysis, higher osmotic resistance, and higher uptake of methylene blue throughout the time of storage than do cells stored without added progesterone. This hormone appears to be in steady-state equilibrium between plasma and red blood cells during 42 days of storage and the amount in the plasma is almost twice that present in the cells. After repeated saline washes, about 10 er cent of the progesterone remains attached to the erythrocytes. Specific association of progesterone with red blood cell populations of different density shows that high specific activity is obtained in cell populations of low density (young cells) throughout the storage time investigated.

Adenosine Triphosphate↗
PubMedDate not supplied

Spirituality in African-American mothers coping with a seriously ill infant.

ISSUES AND PURPOSE: To describe how African-American mothers' spirituality helped them cope during the time of their infants' hospitalization for a serious illness. DESIGN AND METHODS: Fourteen mothers whose infants were seriously ill in the early months of life were interviewed for this retrospective, descriptive study. RESULTS: The core theme related to prayer. Four mothers reported a strengthened faith, while two mothers continued to have difficulty relating to God or attending church. PRACTICE IMPLICATIONS: These findings support the importance of understanding and respecting the spiritual needs and expressions of spirituality in African-American mothers who are coping with a serious illness in one of their children.

Adaptation, Psychological↗
PubMedDate not supplied

Impact of the internet on primary care staff in Glasgow.

BACKGROUND: The Government has invested pound 7 million (approx. $11.5 million) to connect all Primary Care Practices in Scotland to the National Health Service Intranet (NHSnet). This provides General Practitioners (GPs) and Practice Nurses with access to the Internet and a wealth of healthcare information of varying quality. OBJECTIVE: This study examines Primary Care Staff's use of the Internet, their views on the reliability of healthcare information available via the Internet, and their interaction with patients who have presented them with information downloaded from the Internet. METHODS: A postal questionnaire was distributed to a random sample of 300 GPs and 130 Practice Nurses throughout Glasgow. There was a response rate of 60%. RESULTS: Time restraints (20%) and concerns that they lack the necessary skills (17%) were highlighted as the most common reasons for not accessing the Internet. Sixty-nine per cent of GPs and 70% of Practice Nurses had looked at the Internet for healthcare information. Forty-eight per cent of GPs and 41% of Practice Nurses were concerned about the reliability of Internet information. Fifty-eight per cent of GPs and 34% of Practice Nurses have been approached by patients with Internet healthcare information. Sixty-five per cent of the information presented by patients was new to GPs. CONCLUSIONS: The majority of Primary Care Staff now have access to the Internet and use it to look up healthcare information. Almost half of GPs would consider referring their patients to the Internet for further information about their condition. Results highlight that the healthcare information downloaded from the Internet by patients is accurate, but patients have problems correctly interpreting this information. An increase in the use of home computers and free access to the Internet will see a continued increase in patients approaching GPs and Practice Nurses with healthcare information downloaded from the Internet.

Health Knowledge, Attitudes, Practice↗
PubMedDate not supplied

Induction of expression of osteopontin (OPN; secreted phosphoprotein) in metastatic, ras-transformed NIH 3T3 cells.

We have previously shown that transfection of NIH 3T3 cells with the T24 H-ras oncogene converts the cells to a tumorigenic and metastatic phenotype, in proportion to levels of ras expression. We hypothesize that ras-induced increases in malignancy occur via altered expression of various genes. We have identified OPN (osteopontin; also known as Secreted Phosphoprotein, 2ar, Eta-1, and transformation-associated phosphoprotein) as a ras-induced gene in these cells. We report here that expression of OPN RNA and secretion of OPN protein are increased in a series of ras-transformed NIH 3T3 cells, in proportion to levels of expression of ras. Detection of secreted OPN protein was facilitated by a barium citrate precipitation procedure. Although the function of this protein in tumor cells is not known, OPN contains a conserved GRGDS (glycine-arginine-glycine-aspartic acid-serine) amino acid sequence, which may function as a cell attachment site for this protein. We speculate that increased expression of OPN contributes to the increased malignancy of ras oncogene-transformed NIH 3T3 cells, perhaps by alterations in either adhesive properties or integrin-mediated signal transduction pathways.

3T3 Cells↗
PubMedDate not supplied

Comparison of metastatic properties of a variety of mouse, rat, and human cells in assays in nude mice and chick embryos.

We have previously developed an assay to measure experimental metastatic ability of cells following intravenous injection into chorioallantoic membrane (CAM) veins of naturally immune deficient chick embryos. Here we compare metastatic properties of different cell types (ras-transformed and control NIH 3T3, LTA, and 10T1/2; melanoma; and glioma) from several species (mouse, rat, human), using chick embryos and the more commonly-used immune deficient host, nude mice. We found a good correlation between the two assays. Both hosts have advantages and disadvantages in assessing metastatic properties. We conclude that the chick embryo assay is a useful alternative host for experimental metastasis studies. This assay correlates well with and is less costly than assays using nude mice.

Animals↗
PubMedDate not supplied

Resistance of murine LTA cells to oncogene--mediated progression from tumorigenic to metastatic phenotype.

We have previously shown that expression of the H-ras oncogene alone does not induce progression of a tumorigenic but non-metastatic murine fibroblast cell line (LTA) to a metastatic phenotype. Because myc genes, alone or with ras, have been implicated at different stages of progression in other systems, we examined the ability of v-myc, alone and in combination with H-ras, to induce malignant conversion of LTA. We found no increase in either "spontaneous" (assessed after s.c. injection into nude mice) or "experimental" (assessed after i.v. injection into chick embryos) metastatic ability in spite of high levels of v-myc RNA in LTA cells transfected with v-myc alone. Serial in vivo passaging did not consistently select for either myc expression or metastatic ability. Myc transfected cells expressing high levels of myc RNA were subsequently transfected with H-ras. LTA cells expressing both oncogenes at high levels remained non-metastatic. LTA cells thus are resistant to the effects of myc and ras oncogenes (alone and in combination) on a specific stage of tumor progression, that of malignant conversion, and may offer a good model for studying mechanisms of resistance to these oncogenes.

Animals↗
PubMedDate not supplied

Metastatic NIH 3T3 x LTA cell hybrids express 72 kDa type IV collagenase.

We previously reported that the murine fibroblast cell line LTA is tumorigenic but non-metastatic, and is non-responsive to a transfected H-ras oncogene. In contrast, NIH 3T3 cells are non-tumorigenic but are ras-responsive and become metastatic when transfected with ras. Somatic cell hybrids between LTA and NIH 3T3 cells are tumorigenic, metastatic and ras-responsive. Here we examined expression of type IV collagenases in parental LTA and NIH 3T3 cells (with and without ras) and four metastatic LTA x NIH 3T3 hybrids (also with and without ras). Parental NIH 3T3-derived cells had both 72 kDa and 92 kDa gelatinase activities, and LTA-derived cells had either aberrantly sized approximately 90 kDa activity alone or neither enzyme activity. All four metastatic hybrids expressed 60-72 kDa gelatinase activity, while three of them also had 92 kDa activity and one had only minimal 92 kDa activity. Thus the metastatic phenotype of the hybrids was associated with expression of 72 kDa gelatinase. Levels of RNA for tissue inhibitors of metalloproteinases (TIMP-1, TIMP-2) were relatively constant, suggesting independent regulation of type IV collagenases and their inhibitors. Southern blotting and probing with PCR-synthesized cDNA fragments of the mouse 72 kDa type IV collagenase gene showed that this gene was present in all cells although the structure of this gene in one of the three LTA cell lines differed from that of the other cells. Our results suggest that a key change in the metastatic hybrids, relative to non-metastatic parental LTA cells, is induction of expression of 72 kDa type IV collagenase.

3T3 Cells↗
PubMedDate not supplied

MMP-2 expression is associated with, but not sufficient for, malignant conversion of murine LTA cells.

We previously showed that tumorigenic, non-metastatic LTA cells can be converted to a metastatic phenotype either by cell fusion with non-malignant NIH 3T3 cells, or by transfection with genomic DNA from metastatic murine B16F1 or human 1GR37 melanoma cells. In order to identify a gene present in NIH 3T3 cells that is responsible for this conversion, we transferred DNA from an NIH 3T3 genomic library into LTA cells and tested for changes in metastatic properties, assessed in the chick embryo. We found that 3 of 4 pools of transfectant clones showed significantly increased metastatic ability over the vector-only control transfectants. All three metastatic transfectant pools showed significantly increased RNA levels of the 72 kDa type IV gelatinase (MMP-2). To test whether increased expression of MMP-2 was sufficient to convert LTA cells to metastatic ability, we transfected full length MMP-2 cDNA, in a CMV-promoter expression construct, into LTA cells. Stable transfectants with elevated MMP-2 RNA and enzymatic activity were obtained. The highest MMP-2 expressing clone was assayed for experimental metastatic ability in the chick embryo, and found to be no more metastatic than LTA parental cells. We conclude that increased MMP-2 expression accompanies the malignant conversion of LTA cells, but MMP-2 expression alone is not sufficient to bring about this change. The inability of LTA cells to metastasize thus appears to be due to a more complex defect than insufficient MMP-2. This study supports the idea that malignant conversion may require the concerted activation of multiple genes, which are in turn controlled by regulatory genes, whose identification will be important in understanding and controlling metastasis.

3T3 Cells↗