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Biomedical subjects

S Robertson

Publications and source records attributed to S Robertson.

At least 55 records · Page 3Linked to original sources
PubMed2000

Clinical integration and nursing leadership across an integrated delivery system.

As new health systems struggle to combine in today's challenging health care market, mechanisms that facilitate and enhance integration become increasingly important. This article describes the use of clinical paths in an integrated delivery system (IDS) as a methodology to establish a single standard of high-quality care. Through education and sharing of staff development resources across the IDS, the system nurse executive at one large IDS promotes professional practice. As clinical paths are developed across the system, the best clinical practice is put to paper, providing a framework for outcome-driven care. The nurse manager assesses staff's use of clinical paths as an evaluation of their skills and competency and to identify new educational and growth opportunities.

Benchmarking↗
PubMed1999

Hematopoietic commitment during embryogenesis.

Hematopoiesis develops initially as discrete blood islands in the extraembryonic yolk sac of the embryo. These blood islands consist of clusters of primitive erythrocytes surrounded by developing angioblasts that ultimately form the yolk sac vasculature. The close developmental association of these early hematopoietic and endothelial cells has led to the hypothesis that they develop from a common precursor, a cell known as the hemangioblast. Using a developmental model system based on the in vitro differentiation capacity of embyronic stem (ES) cells, we have identified a precursor with the capacity to generate endothelial as well as primitive and definitive hematopoietic progeny. The developmental potential of this precursor population suggests that it represents the in vitro equivalent of the hemangioblast.

Animals↗
PubMed1999

Tolcapone (Tasmar)

Explore the source record for details and available documents.

Antiparkinson Agents↗
PubMed1999

Continuing education programme - Victorian Institute of Forensic Medicine and Department of Forensic Medicine, Monash University.

Given the increasing requirement of the courts for forensic experts to engage in ongoing education, a continuing education programme was developed in forensic medicine at the Victorian Institute of Forensic Medicine to cater for both clinicians and pathologists. The programme consists of a series of cases which are circulated several times per year. All are actual cases and are reflective of the types of presentations experienced in forensic medicine. Each case includes relevant and appropriate details/findings and may include photographs. A series of questions follow which are answered usually in short-answer format. The answers are returned and correlated by a review panel, and a commentary with the response outcome is distributed to all those involved. The cases presented here are selected from this programme.

Journal Article↗
PubMed1999

Composite renal cell carcinoma and angiomyolipoma: a study of the histogenetic relationship of the two lesions.

The purpose of the present study was to investigate the possible histogenetic relationship of renal cell carcinoma (RCC) and angiomyolipoma (AMYL) occurring in the same renal nodule by examining two cases of composite RCC and AMYL in patients without stigmata of tuberous sclerosis and by reviewing the medical literature of similar cases. Case 1 represents an epithelioid variant of AMYL with multiple additional nodules of typical AMYL in a surgically removed kidney. The patient subsequently developed a lesion consisting of a mixture of epithelioid variant of AMYL and RCC 24 months later in the retroperitoneum and, an additional 4 months later, in the liver. The RCC cells resembled mononucleated epithelioid cells of the epithelioid AMYL except that they were focally reactive with epithelial membrane antigen (EMA) in the retroperitoneum and focally reactive with both EMA and cytokeratin (CK) in the liver. Case 2 consisted of a typical AMYL admixed with a chromophil cell RCC. A review of the medical literature revealed seven additional cases with histopathological findings similar to this case. All cases had multiple foci of typical AMYL. Immunostaining results are available in five tumors. Chromophil RCC showed variable reactivity with CK and EMA. In addition, RCC in the two cases in the present study also displayed a positive reaction with mucin staining and a positive reactivity with carcinoembryonic antigen. There appears to be a spectrum of histopathological and immunohistochemical changes from the epithelioid variant of AMYL through a mixed epithelioid AMYL/RCC to chromophil RCC in three successive specimens in case 1. Moreover, the intimate admixture of AMYL and RCC and the similar expression of epithelial markers of RCC in the two cases in the present study, as well as other cases in the literature, suggest that some RCC develop from the same precursor cell as AMYL or from a component of AMYL.

Adult↗
PubMed1999

Depressed T-cell interferon-gamma responses in pulmonary tuberculosis: analysis of underlying mechanisms and modulation with therapy.

Immunological and clinical profiles were evaluated in 2 groups: human immunodeficiency virus (HIV)-uninfected and HIV-infected patients, with newly diagnosed pulmonary tuberculosis (TB), and tuberculin-skin-test-reactive healthy control subjects. HIV-uninfected patients with TB were also followed up longitudinally during and after chemotherapy. At the time of diagnosis, purified protein derivative (PPD)-stimulated production of interferon (IFN)-gamma by peripheral blood mononuclear cells from TB patients was depressed, compared with that of healthy control subjects, whereas levels of transforming growth factor (TGF)-beta and interleukin (IL)-10 were increased. In longitudinal studies, PPD stimulated production of IL-10 and TGF-beta returned to baseline by 3 months, whereas IFN-gamma production remained depressed for at least 12 months. These data indicate that the immunosuppression of TB is not only immediate and apparently dependent (at least in part) on immunosuppressive cytokines early during the course of Mycobacterium TB infection but is also long lasting, presumably relating to a primary abnormality in T-cell function.

Adolescent↗
PubMed1999

Management of renovascular disease: a review of renal artery stenting in ten studies.

To evaluate the efficacy and safety of renal artery stents in renovascular disease, we identified 10 descriptive studies containing sufficient information for systematic evaluation. No randomized comparisons of stenting with angioplasty or with surgery were found. Overall, stents were placed in 416 renal arteries in 379 patients, mean age 64 years (range 27-84), 56% male. Of the stenoses, 97% were atheromatous (inter-study range 71-100%), 80% ostial (22-100%) and 31% bilateral (12-87%). The clinical indication for stenting was usually hypertension with or without mild renal impairment. Radiological indications for stenting were: narrowing of > or = 50% (in 9/10 studies) as a result of elastic recoil (58%) or dissection (2%) at the time of angioplasty; restenosis some time after angioplasty (15%); or as a primary procedure (25%). Technical success was reported in 96-100% of procedures. Restenosis (> or = 50% narrowing), evaluated in 312/416 (75%) arteries, generally between 6 and 12 months, was 16% overall. Hypertension was cured by stenting (DBP < or = 90 mmHg on no treatment) in 34/379 (9%) overall and in 34/207 (16%) of those whose renal function was normal initially. Six of 379 (1.6%) patients died within 30 days of stenting, but in only two (0.5%) was death judged to be procedure-related. Complications, other than those which led to dialysis, occurred in 42/379 (13%) patients, one third requiring intervention, ranging from blood transfusion to a surgical bypass procedure. Renal function as judged by serum creatinine concentration (SCC) improved in 26%, stabilized in 48% and deteriorated in 26% of patients whose renal function was impaired initially (SCC > 133 mumol/l). In one study, with average baseline SCC > 200 mumol/l, successful stenting slowed the rate of progression of renal failure when renal function was deteriorating beforehand. Nine of 379 (2.4%) patients, including 7/14 (50%) whose SCC was > or = 400 mumol/l initially, required dialysis after stenting. Stenting should be offered by specialist centres as a secondary procedure for unsuccessful angioplasty, or restenosis following angioplasty, to patients with renovascular disease and uncontrolled hypertension, advancing renal failure or pulmonary oedema.

Age Distribution↗
PubMed1999

Development of erythroid and myeloid progenitors in the yolk sac and embryo proper of the mouse.

In this study, we have mapped the onset of hematopoietic development in the mouse embryo using colony-forming progenitor assays and PCR-based gene expression analysis. With this approach, we demonstrate that commitment of embryonic cells to hematopoietic fates begins in proximal regions of the egg cylinder at the mid-primitive streak stage (E7.0) with the simultaneous appearance of primitive erythroid and macrophage progenitors. Development of these progenitors was associated with the expression of SCL/tal-1 and GATA-1, genes known to be involved in the development and maturation of the hematopoietic system. Kinetic analysis revealed the transient nature of the primitive erythroid lineage, as progenitors increased in number in the developing yolk sac until early somite-pair stages of development (E8.25) and then declined sharply to undetectable levels by 20 somite pairs (E9.0). Primitive erythroid progenitors were not detected in any other tissue at any stage of embryonic development. The early wave of primitive erythropoiesis was followed by the appearance of definitive erythroid progenitors (BFU-E) that were first detectable at 1-7 somite pairs (E8.25) exclusively within the yolk sac. The appearance of BFU-E was followed by the development of later stage definitive erythroid (CFU-E), mast cell and bipotential granulocyte/macrophage progenitors in the yolk sac. C-myb, a gene essential for definitive hematopoiesis, was expressed at low levels in the yolk sac just prior to and during the early development of these definitive erythroid progenitors. All hematopoietic activity was localized to the yolk sac until circulation was established (E8.5) at which time progenitors from all lineages were detected in the bloodstream and subsequently in the fetal liver following its development. This pattern of development suggests that definitive hematopoietic progenitors arise in the yolk sac, migrate through the bloodstream and seed the fetal liver to rapidly initiate the first phase of intraembryonic hematopoiesis. Together, these findings demonstrate that commitment to hematopoietic fates begins in early gastrulation, that the yolk sac is the only site of primitive erythropoiesis and that the yolk sac serves as the first source of definitive hematopoietic progenitors during embryonic development.

Animals↗
PubMed1999

Telemedicine for clinical psychology in the Highlands of Scotland.

Telemedicine may be useful in the delivery of clinical psychology services in the Highlands of Scotland, where geographical size and sociodemographic factors can hinder service delivery. The Highlands have a population of 210,000 at a density of approximately 8 people/km2, one of the lowest in the European Union. Despite a general lack of formal evaluation of telemedicine, especially in mental health, descriptive studies and patient satisfaction reports give grounds for optimism. There are several current applications of telemedicine in the Highlands, including cognitive-behavioural therapy, a comparative evaluation of neuropsychological assessments, and the treatment of children and their families. The projects are being formally evaluated and early results are encouraging.

Humans↗
PubMed1999

Prognostic significance of apoptosis regulators in breast cancer.

Dysregulation of normal programmed cell death mechanisms plays an important role in the pathogenesis and progression of breast cancer, as well as in responses of tumors to therapeutic intervention. Overexpression of anti-apoptotic members of the Bcl-2 family such as Bcl-2 and Bcl-X(L) has been implicated in cancer chemoresistance, whereas high levels of pro-apoptotic proteins such as Bax promote apoptosis and sensitize tumor cells to various anticancer therapies. Though the mechanisms by which Bcl-2 family proteins regulate apoptosis are diverse, ultimately they govern decision steps that determine whether certain caspase family cell death proteases remain quiescent or become active. To date, approximately 17 cellular homologs of Bcl-2 and at least 15 caspases have been identified in mammals. Other types of proteins may also modulate apoptotic responses through effects on apoptosis-regulatory proteins, such as BAG-1-a heat shock protein 70 kDa (Hsp70/Hsc70)-binding protein that can modulate stress responses and alter the functions of a variety of proteins involved in cell death and division. In this report, we summarize our attempts thus far to explore the expression of several Bcl-2 family proteins, caspase-3, and BAG-1 in primary breast cancer specimens and breast cancer cell lines. Moreover, we describe some of our preliminary observations concerning the prognostic significance of these apoptosis regulatory proteins in breast cancer patients, contrasting results derived from women with localized disease (with or without node involvement) and metastatic cancer.

Antineoplastic Agents↗
PubMed1999

Disseminated coccidioidomycosis. The role of cytology in multidisciplinary clinical approach and diagnosis.

A case of clinically unsuspected disseminated coccidioidomycosis diagnosed by different cytologic approaches and confirmed by mycological culture is reported. An African-American man presented with a clinical picture of pneumonia not responding to antibiotics. He subsequently developed a large neck mass and was found to have mediastinal and hilar adenopathy highly suspicious of a neoplastic process. Fine needle aspiration biopsy of the neck mass, followed by flexible bronchoscopy, was performed. Various cytologic approaches and techniques in rapid diagnosis of suspicious masses are discussed.

Biopsy, Needle↗
PubMed1999

The new genetics. What are the everyday clinical applications?

BACKGROUND: Our understanding of human genetics has changed exponentially in recent years, but genetic research is sometimes perceived as an esoteric and expensive pursuit with few practical implications for the majority of the population. As the human genome project nears completion, we need to assess how we can use this vast knowledge effectively. OBJECTIVE: To focus on the role of new genetics in the understanding of both single gene disorders and the inheritance of complex traits (which have genetic and environmental components) and to discuss the role of the general practitioner (GP) utilising this knowledge in daily practice. DISCUSSION: Genetic data is often best used to understand and modify environmental causes of disease in regard to the susceptibility of an individual or family. This article discusses the role of GPs in identifying those at high risk of disease by history, prenatal diagnostic techniques and appropriate genetic testing and providing practical, cost effective strategies for individuals and the community to minimise risk of illness.

Family Practice↗
PubMed1998

Differentiation of human NK cells into NK1 and NK2 subsets.

Human NK cells cultured in the presence of IL-12 or IL-4 differentiate into cell populations with distinct patterns of cytokine secretion similar to Th1 and Th2 cells. NK cells grown in IL-12 (NK1) produce IL-10 and IFN-gamma, whereas NK cells grown in IL-4 (NK2) produce IL-5 and IL-13. Although these NK cell subsets do not differ in cytotoxic activity, NK1 cells express higher levels of cell surface CD95 (Fas) Ag than NK2 cells and are more sensitive to Ab or chemically induced apoptosis. Like Th1 cells, NK1 cells accumulate much higher levels of the IL-12Rbeta2-chain mRNA and are significantly more responsive to IL-12 than NK2 cells at the level of activation of STAT4 transcription factor. The identification of NK cell subsets that are analogous to T cell subsets suggests a new role for NK cells in innate inflammatory responses and in their effect on adaptive immunity.

Apoptosis↗
PubMed1998

Serum prostate-specific antigen profile following radiotherapy for prostate cancer: implications for patterns of failure and definition of cure.

OBJECTIVES: A reference range of prostate-specific antigen (PSA) values compatible with cure following radiotherapy (RT) for prostate cancer (PCa) has yet to be established. Various thresholds, as low as 0.5 ng/mL, have been used to define biochemical disease-free status. We report PSA profiles in 118 patients who were systematically biopsied following standard RT, with a minimum 4-year follow-up. METHODS: One hundred eighteen patients were treated with standard external beam RT from May 1987 to October 1991, and were followed prospectively with transrectal ultrasound (TRUS)-guided biopsies and measurement of serum PSA levels. Stage distribution was as follows: T1b: 25 patients, T2a: 27 patients, T2b/c: 42 patients, T3: 23 patients, T4: 1 patient. Median follow-up for patients without clinical failure is 68 months (range 48 to 108). Treatment failures were categorized as biochemical (biochemical failure [chemF]: PSA level of 2.0 ng/mL or more and greater than 1 ng/mL over nadir), local (local failure [LF]: positive biopsy and PSA level greater than 2.0), and distant failure (DF). RESULTS: PCa recurred in 55% of patients: 38% LF (n = 45; 30 isolated and 15 with DF), 25% DF (n = 30; 15 isolated and 15 with LF), and 4% chemF (n = 5). Mean PSA nadir was 0.4 for patients with no evidence of disease (NED) and occurred at 33 months, 3.2 for LF at 17 months, 7.7 for DF at 12 months, and 1.4 for chemF at 24 months. After reaching the nadir, PSA in patients with recurrence followed first-order kinetics, rising exponentially over time. The mean PSA doubling time was 12.6 months for LF, 5.2 months for DF, and 21.8 months for chemF (P = 0.004). At last follow-up, the median PSA for patients without evidence of disease is 0.5 ng/mL. Four such patients had PSA values that rose to between 1 and 2 ng/mL for 5 to 38 months, but these eventually fell again to less than 1 ng/mL. Three patients had PSA values between 2 and 3 ng/mL, but 2 now have decreasing levels and the third has a rising level. All patients whose PSA levels rose to greater than 3 ng/mL exhibited a persistently rising pattern and ultimate tumor recurrence. CONCLUSIONS: There is a range of PSA values following RT for PCa that is compatible with cure. A definition of biochemical disease-free status at any absolute threshold of PSA level less than 3 ng/mL will overdiagnose failure in a significant proportion of patients. Patients with a PSA level between 1.5 and 3 ng/mL should be observed until there is unequivocal evidence of disease recurrence. In the absence of known biopsy status, PSA doubling time can be a useful indicator of whether failure is local or distant.

Aged↗
PubMed1998

Buccal absorption of etomidate from a solid formulation in dogs.

UNLABELLED: Etomidate is typically administered i.v. for the induction of general anesthesia. We believe that oral transmucosal absorption may extend etomidate's use to premedication and conscious sedation. Our objective was to study the oral mucosal absorption kinetics and bioavailability of etomidate in a solid dose form in dogs. A solid dose form containing 50 mg of etomidate in sorbitol for buccal administration was prepared. Each dog was administered both i.v. etomidate and buccal etomidate on separate days. Serum etomidate concentrations after i.v. administration were fit to a two-compartment pharmacokinetic model. The rates at which etomidate enters the systemic circulation via buccal mucosal absorption were calculated from serum concentrations from mucosal and i.v. administrations using model-dependent constrained numerical deconvolution. The apparent permeability coefficient and bioavailability were also determined. The mean (+/- SD) maximal serum etomidate concentration after buccal mucosal absorption from the 50-mg dose unit was 239 +/- 79 ng/mL. The time to reach maximal serum concentration was 12.5 +/- 1.8 min. Peak absorption rate of etomidate into the systemic circulation was 832 +/- 417 microg/min. For all dogs, 90% or more of the absorption via buccal mucosa took place during the period in which the drug was in contact with the mucosa (15 min). The apparent transbuccal mucosal permeability coefficient was 9.1 +/- 4.2 x 10(-4) cm/s, higher than values of any other compounds examined. Bioavailability calculated using the area under the serum etomidate concentration versus time curve method and the deconvolution method was 13.6% +/- 10.7% and 16.6% +/- 7.6%, respectively. In conclusion, etomidate is highly permeable through the canine buccal mucosa. IMPLICATIONS: Etomidate is highly permeable through the canine buccal mucosa. Both the onset and the termination of buccal mucosal absorption of etomidate are rapid, which suggests that titratable delivery of etomidate may be possible by buccal administration.

Absorption↗