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Biomedical subjects

G Patterson

Publications and source records attributed to G Patterson.

At least 19 recordsLinked to original sources
PubMed2001

An integrated CMOS microluminometer for low-level luminescence sensing in the bioluminescent bioreporter integrated circuit.

We report an integrated CMOS microluminometer for the detection of low-level bioluminescence in whole cell biosensing applications. This microluminometer is the microelectronic portion of the bioluminescent bioreporter integrated circuit (BBIC). This device uses the n-well/p-substrate junction of a standard bulk CMOS IC process to form the integrated photodetector. This photodetector uses a distributed electrode configuration that minimizes detector noise. Signal processing is accomplished with a current-to-frequency converter circuit that forms the causal portion of the matched filter for dc luminescence in wide-band white noise. Measurements show that luminescence can be detected from as few as 4 x 10(5) cells/ml.

Biosensing Techniques↗
PubMed1999

The role of the Sysmex SE9000 immature myeloid index and Sysmex R2000 reticulocyte parameters in optimizing the timing of peripheral blood stem cell harvesting in patients with lymphoma and myeloma.

Peripheral blood CD34/45+ cell (CD34/45) enumeration is an expensive and labour-intensive investigation but remains the standard assay for optimizing yield and timing of peripheral blood stem cell harvesting (PBSCH). The present study examined the value of the Sysmex SE9000 parameters (WBC, neutrophil count, and immature myeloid index (IMI)) and Sysmex R2000 reticulocyte parameters (absolute, high and medium fluorescence reticulocytes) in predicting the optimum timing of PBSCH in comparison to peripheral blood CD34/45. Sixty-four PBSCH from 23 patients with haematological malignancies were assessed with a variety of mobilization regimes used. Reticulocyte parameters showed high interpatient variability and did not prove clinically useful. IMI did not consistently predict satisfactory PBSCH yield except when > 1000 x 10(6)/l. Peripheral blood CD34/45 was the most useful predictor of yield. IMI > 20 x 10(6)/l was, however, a useful surrogate for predicting a rise in peripheral blood CD34/45 from nadir and proved to be superior to WBC or neutrophil count. A rising IMI is a marker of early regeneration and has a role in determining when to initiate enumeration of peripheral blood CD34/45.

Blood Cell Count↗
PubMed1999

Adoption and race: implementing the Multiethnic Placement Act and the Interethnic Adoption Provisions.

Passage of the Multiethnic Placement Act of 1994 (MEPA) and the 1996 provisions on Removal of Barriers to Interethnic Adoption (Interethnic Adoption Provisions) provides an ideal opportunity to examine what can be done to increase adoptions of foster children, particularly children of color. To assist states and child welfare professionals in serving children better and meeting legal obligations, this article discusses racial matching, MEPA, and the Interethnic Adoption Provisions. Implications for practice and challenges in implementing the law also are discussed. The article suggests principles for adoption practice, recruitment, and placement that provide a framework for simultaneously meeting the requirements of the law and serving the best interests of children. Recommendations for practice, policy, and research are offered.

Adoption↗
PubMed1998

British retirees in Malta: components of the cross-national relationship.

"The paper focuses on three aspects of the retirement of British citizens to Malta and Gozo: the evolution of the British settlement, four pathways to the islands, and the formation of the current demographic and household characteristics.... The immigration of British retirees to Malta has fluctuated in volume and character over the last 35 years, partly in response to changes in Maltese fiscal and residence policies, and partly reflecting the changing demand for overseas retirement settlement in the UK. The substantial contribution of intercommunal married couples to the British retired resident population and the buoyancy of both tourist visits and new arrivals suggests that its size will at least be stable or will grow slowly for many decades to come."

Adult↗
PubMed1998

"An empire lost but a province gained": a cohort analysis of British international retirement in the Algarve.

"The growth of international retirement in the Algarve has coincided with a number of changes in the international framework for population mobility as well as in the nature of the Algarve [Portugal] as a destination area. Tourism development, which is intimately linked to subsequent retirement migration, is particularly important in this. This paper considers the nature of the link between cycles of migration and of development in recipient areas, in the context of the remarkable and relatively late development of the Algarve as an area of tourism and retirement.... Cohort analysis...provides the basis for an examination of changes over time in the socio-demographic profiles of the migrants, their motivations, their residential patterns and their integration."

Acculturation↗
PubMed1998

Diverse paths: the elderly British in Tuscany.

"This paper investigates the life, migration and retirement experiences of elderly British residents of Tuscany and its adjacent districts.... Many pathways have led the elderly British to Tuscany; only a minority have simply migrated from the UK on retirement.... Key themes explored include class background, reasons for migration to Tuscany, previous connections to Italy, post-retirement behaviour, integration and future plans. The findings challenge some commonly-held ¿expectations' about the nature of retirement migration."

Acculturation↗
PubMed1997

Treatment of human prostate tumors PC-3 and TSU-PR1 with standard and investigational agents in SCID mice.

Both the PC-3 and the TSU-PR1 prostate tumor models were found to be satisfactory for chemotherapeutic investigations in ICR-SCID mice. The 30 to 60 mg fragments implanted took in all mice (as judged by 100% takes in the controls of all experiments as well as the passage mice). The tumor volume doubling time was 4.0 days for PC-3 and 2.5 days for TSU-PR1. Nine agents were evaluated IV against early stage subcutaneous PC-3 tumors, with Nano-piposulfan being the only agent highly active (4.9 log kill). Three other agents were moderately active: Taxol (1.5 log kill), Cryptophycin-8 (1.6 log kill), Vinblastine (1.0 log kill). Five agents were inactive: VP-16, Adriamycin, CisDDPt, 5-FUra, and Cyclophosphamide. Ten agents were evaluated IV against early stage subcutaneous TSU-PR1 tumors. Three agents were highly active, producing > 6 log kill and cures: Taxol (5/5 cures), Cryptophycin-8 (5/5 cures), Vinblastine (2/4 cures). Two other agents were moderately active: Nano-piposulfan (1.2 log kill), and Cyclophosphamide (1.1 log kill). Five agents were inactive: VP-16, Adriamycin, CisDDPt, 5-FUra, and BCNU. In part, activity was determined by the ability of the SCID mice to tolerate meaningful dosages of the agents. Agents producing granulocyte toxicity (e.g., Adriamycin) were poorly tolerated and appeared less active than expected. Vinblastine, producing little or no granulocyte toxicity was very well tolerated and appeared to be more active than expected.

Aged↗
PubMed1997

Discovery of cryptophycin-1 and BCN-183577: examples of strategies and problems in the detection of antitumor activity in mice.

Historically, many new anticancer agents were first detected in a prescreen; usually consisting of a molecular/biochemical target or a cellular cytotoxicity assay. The agent then progressed to in vivo evaluation against transplanted human or mouse tumors. If the investigator had a large drug supply and ample resources, multiple tests were possible, with variations in tumor models, tumor and drug routes, dose-decrements, dose-schedules, number of groups, etc. However, in most large programs involving several hundred in vivo tests yearly, resource limitations and drug supply limitations have usually dictated a single trial. Under such restrictive conditions, we have implemented a flexible in vivo testing protocol. With this strategy, the tumor model is dictated by in vitro cellular sensitivity; drug route by water solubility (with water soluble agents injected intravenously); dosage decrement by drug supply, dose-schedule by toxicities encountered, etc. In this flexible design, many treatment parameters can be changed during the course of treatment (e.g., dose and schedule). The discovery of two active agents are presented (Cryptophycin-1, and Thioxanthone BCN 183577). Both were discovered by the intravenous route of administration. Both would have been missed if they were tested intraperitoneally, the usual drug route used in discovery protocols. It is also likely that they would have been missed with an easy to execute fixed protocol design, even if injected i.v.

Animals↗
PubMed1995

Analysis of bronchoalveolar lavage from human lung transplant recipients by flow cytometry.

Bronchoalveolar lavage (BAL) cells and peripheral blood leucocytes (PBL) from 24 lung transplant recipients were analysed for leucocyte subsets and expression of cell surface antigens. Total and differential white cell counts were performed on BAL, and lymphocyte subsets were evaluated in both BAL and peripheral blood. Measurement of immunofluorescence by flow cytometry was used to assess the percentage of: T cells (CD3+); T-helper cells (CD4+); T-cytotoxic/suppressor cells (CD8+); and activated lymphocytes (HLA-DR+). Lymphocyte subsets in BAL demonstrated marked differences to those in blood. A lower percentage of CD3+ and CD4+ lymphocytes were found in BAL, whereas CD8+ cells were more prevalent in BAL than in PBL. The mean CD4:CD8 ratio was significantly lower in BAL (1:1) than in blood (2.1:1). In the absence of pulmonary infection, there was a trend for a lower CD4:CD8 ratio in BAL associated with acute rejection (1.1:1) and obliterative bronchiolitis (1:1), when compared to the group with no evidence of rejection (1.4:1). In the absence of pulmonary rejection, pulmonary infection was associated with a marginally lower CD4:CD8 ratio in BAL (0.7:1), than when infection was absent (1.4:1). This difference was more evident in cases of cytomegalovirus (CMV) infection with a mean CD4:CD8 ratio of 0.3:1, compared to 1.5:1 in the absence of CMV disease (P < 0.05).

Adolescent↗
PubMed1994

Insulin withholding for weight control in women with diabetes.

OBJECTIVE: To provide a description of the clinical characteristics that distinguish individuals who withhold insulin for weight control from those who do not. Some individuals with insulin-dependent diabetes mellitus (IDDM) control their weight by withholding insulin and purging excessive calories. This process places patients at risk for developing severe hyperglycemia, diabetic ketoacidosis, and increases the risk of long-term complications of diabetes. RESEARCH DESIGN AND METHODS: Forty-two women with IDDM, ages 16-40, were interviewed and divided into two groups: insulin withholders (IWs) and non-insulin withholders (non-IWs). These groups were compared on physiological, behavioral, psychological, and psychiatric variables. RESULTS: Compared with non-IWs, patients who withheld insulin to control their weight exhibited poorer glycemic control, reported more negative attitudes toward diabetes, were more likely to have pathological scores on the Eating Disorder Inventory 2, and were more likely to report current or past symptoms of anorexia or bulimia nervosa. IWs were also more likely to report lying to physicians about their degree of compliance with their diabetes regimens. CONCLUSIONS: The results of this study indicated that IWs exhibit more symptoms associated with the spectrum of eating disorders than non-IWs. This study showed that insulin withholding for weight control not only exists, but is associated with some maladaptive symptoms and behaviors that need to be addressed by diabetes treatment teams.

Adolescent↗
PubMed1993

Cytokine gene expression in human lung transplant recipients.

The polymerase chain reaction was used to evaluate cytokine gene expression in bronchoalveolar lavage (BAL) cells and peripheral blood leukocytes in 31 human lung transplant recipients. All patients were maintained on a triple immunosuppression regimen consisting of CsA, AZA, and prednisone. Posttransplant survival ranged from 0.5 to 100.5 months (mean = 16.3 months). Cytokines IL-1 alpha, IL-2, IL-4, IL-5, IL-6, IL-7, IL-8, TNF-beta, and IFN-gamma were studied. In BAL, transcripts for IL-1 alpha, IL-7, IL-8, and TNF-beta were found in over 60% of samples and those for IL-5, IL-6, and IFN-gamma in 40-50%, while IL-2 and IL-4 mRNA were rarely found (< 20%). Considerable variation in the frequency of cytokine gene expression between BAL and peripheral blood was observed. When analyzed for the presence of acute pulmonary allograft rejection (without infection), transcripts for IL-4 and IL-6 in BAL demonstrated the greatest increase in frequency compared with nil rejection (P = 0.07 and P = 0.17, respectively). Pulmonary infection (without rejection) was associated with a modest increase in the expression of genes for IL-1 alpha and IFN-gamma (> 10%). Transcripts for IL-4 were not found in association with pulmonary infection, suggesting that this cytokine may be useful as a discriminatory rejection marker.

Adolescent↗
PubMed1990

On the development of an integrated computer system for cephalometric analyses.

This paper describes a microcomputer based system that integrates image processing and computer graphics techniques to automate the data extraction and storage process in cephalometric analyses. The system increases the consistency of measurements and improves the productivity of surgical and dental staff.

Cephalometry↗