PubMed Health⌕ Search

Biomedical subjects

John Turner

Publications and source records attributed to John Turner.

16 recordsLinked to original sources
PubMed2006

CD10 expression in trichoepithelioma and basal cell carcinoma.

BACKGROUND: Trichoepithelioma (TE) is a benign neoplasm that shares both clinical and histologic features with basal cell carcinoma (BCC). However, it is important to distinguish these neoplasms. Limited immunohistochemical stains are available to separate these two tumors. METHODS: CD10 protein immunohistochemistry was performed on paraffin-embedded biopsies of 13 TE and 23 BCC diagnosed by routine microscopy. Cases were analyzed for pattern of CD10 expression by tumor cells and surrounding stroma. RESULTS: Twelve of 13 (92%) TE showed positive stromal immunoreactivity. Of these, eight cases also demonstrated positivity of the papilla, and two also showed positivity of the basaloid cells. No TE demonstrated epithelial expression alone. On the other hand, expression of CD10 by basaloid cells was identified in 20 (87%) cases of BCC. Stromal positivity was also identified in three cases of BCC. Condensation of CD10-positive stromal cells around basaloid nests was statistically significant in differentiating TE from BCC (p < 0.0001). Conversely, CD10-positive basaloid cells were seen predominantly in BCC (p < 0.0001). CONCLUSIONS: This study demonstrates a statistically significant difference in CD10 staining pattern between TE and BCC. Thus, CD10 may be a useful adjunct marker in distinguishing these tumors.

Adult↗
PubMed2006

Lymph nodes in colorectal carcinoma. The Poisson probability paradigm.

This article introduces use of the Poisson probability density function and Bayes probability rule to understand and analyze lymph nodal metastases in colorectal carcinoma. We apply these models to 370 patients who underwent resection of their tumors. In 213 cases with negative lymph nodes, we found that the Bayes-estimated probability of missed metastases was related significantly to subsequent survival (P = .0006). In 157 cases with lymph nodal metastases, we found that the estimated value of the Poisson parameter a was associated more closely with subsequent survival than pN stage (P = 9 10(-6)). Consequently, we believe that the Poisson model provides insight and useful results in colorectal carcinoma.

Adenocarcinoma↗
PubMed2005

Coral reefs of the Mascarenes, Western Indian Ocean.

The reefs of the Mascarenes differ in structure and stage of development. Mauritius is the oldest island, bound by a discontinuous fringing reef and small barrier reef, with large lagoon patch reefs. Rodrigues has nearly continuous fringing reefs bounding an extensive lagoon with deep channels and few patch reefs. Reunion, the youngest island, has short stretches of narrow fringing reefs along southwestern coasts. The islets of St Brandon are bound to the east by an extensive arc of fringing reef. Reef mapping of the Mascarenes using satellite imagery provides an estimate of 705 km2 of shallow reef habitats. These areas have been modified over geological time by changes in sea level, ocean-atmosphere disturbances and biological and chemical forcing. Further modification has resulted from historical changes in land-use patterns. Recent economic development has placed many of these reefs at risk from anthropogenic impact. The reefs of the Mascarenes have escaped mass mortality from bleaching to date, which increases their conservation significance within the wider Indian Ocean. The reefs are poorly protected. A case study shows how a geographic information system incorporating reef-habitat maps can help formulate and demonstrate Marine Protected Area boundaries.

Animals↗
PubMed2005

A comparison of early retirement pensions in the United States and Russia: the pensions of musicians.

Early retirement pensions for particular occupations free national policy to establish the social security early retirement age at a later age that is more appropriate for the population as a whole. This paper focuses on early retirement pensions in the United States and the Russian Federation. While comparing early retirement pensions generally, the paper provides a more detailed discussion of the pensions for musicians. While this is an unconventional group to choose for the study of pensions, study of their pensions yields insights into the principles underlying retirement age policy in the two countries.

Adult↗
PubMed2005

Increased blasts mimicking acute leukemia in a patient with polysubstance abuse.

Toxic insult to the bone marrow may result in partial or complete suppression, with or without reactive changes, and probable eventual regeneration of hematopoietic elements. During the regenerative process, increased blasts may be observed. Distinguishing these changes from an acute leukemic process can be difficult. In particular, the diagnosis of hypocellular bone marrow with increased blasts, also known as hypocellular or hypoplastic acute leukemia, presents a diagnostic dilemma for pathologists. We report a case of hypocellular marrow with increased blasts in a 50-year-old man with an extensive history of alcohol and drug abuse in whom chemotherapy was deferred. Recovery of peripheral blood cell counts and reticulocytosis occurred with withdrawal of the offending agents, and he remains alive and well 1 year later.

Acute Disease↗
PubMed2003

B-type natriuretic peptides and ejection fraction for prognosis after myocardial infarction.

BACKGROUND: A recent landmark report has demonstrated that plasma B-type natriuretic peptide (BNP) measured in acute coronary syndromes independently predicts mortality, heart failure, and new myocardial infarction. After acute cardiac injury, left ventricular ejection fraction (LVEF) is also of prognostic significance and plays a major role in determining the therapeutic response. METHODS AND RESULTS: The present report is the first from a substantial (n=666) cohort of patients with acute myocardial infarction to test the prognostic utility of concurrent measurements of BNP, amino-terminal BNP (N-BNP), norepinephrine, and radionuclide LVEF. The B-type peptides and LVEF were predictors of death, heart failure, and new myocardial infarction (all P<0.001) independent of patient age, gender, previous myocardial infarction, antecedent hypertension or diabetes, previous heart failure, plasma norepinephrine, creatinine, cholesterol, drug therapy, and coronary revascularization procedures. The combination of N-BNP (or BNP) with LVEF substantially improved risk stratification beyond that provided by either alone. Elevated N-BNP (or BNP) predicted new myocardial infarction only in patients with LVEF <40%. LVEF <40% coupled to N-BNP over the group median conferred substantial 3-year risks of death, heart failure, and new myocardial infarction of 37%, 18%, and 26%, respectively. N-BNP and BNP were equivalent prognostic markers for these clinical outcomes. CONCLUSIONS: Plasma N-BNP (or BNP) and LVEF are complementary independent predictors of major adverse events on follow-up after myocardial infarction. Combined measurement provides risk stratification substantially better than that provided by either alone.

Adult↗
PubMed2003

Bioaccessibility testing of cobalt compounds.

Testing of metal compounds for solubility in artificial fluids has been used for many years to assist determining human health risk from exposure to specific compounds of concern. In lieu of obtaining bioavailability data from samples of urine, blood, or other tissues, these studies measured solubility of compounds in various artificial fluids as a surrogate for bioavailability. In this context, the measurement of metal "bioaccessibility" can be used as an in vitro substitute for measuring metal bioavailability. Bioaccessibility can be defined as a value representing the availability of metal for absorption when dissolved in in vitro surrogates of body fluids or juices. The aim of this study was to measure and compare the bioaccessibility of selected cobalt compounds in artificial human tissue fluids and human serum. A second aim was to initiate studies to experimentally validate an in vitro methodology that would provide a conservative estimate of cobalt bioavailability in the assessment of dose from human exposure to various species of cobalt compounds. This study evaluated the bioaccessibility of cobalt(II) from 11 selected cobalt compounds and an alloy in 2 physical forms in 5 surrogate human tissue fluids and human serum. Four (4) separate extraction times were used up to 72 hours. The effect of variables such as pH, dissolution time, and mass-ion effect on cobalt bioaccessibility were assessed as well. We found that the species of cobalt compound as well as the physico-chemical properties of the surrogate fluids, especially pH, had a major impact on cobalt solubility. Cobalt salts such as cobalt(II) sulfate heptahydrate were highly soluble, whereas cobalt alloys used in medical implants and cobalt aluminate spinels used as pigments, showed minimal dissolution over the period of the assay.

Alloys↗
PubMed2003

Exercise-related headache.

Headache related to exercise is present in many active individuals. Prospective studies on exercise-related headache are rare. There are several subtypes of headache either exacerbated or caused exclusively by exercise or exertion. Many descriptors exist, but few clear guidelines have been established to allow the practitioner to easily differentiate and treat these subtypes. Recent research has gained insight into new types of exertional headache, as well as broadened our understanding of known types. Other reviews have recommended careful thorough screening of patients with sudden onset of headache during or shortly after exercise. This article offers a concise overview of current thinking and recent investigation, as well as areas that need continued exploration.

Adolescent↗
PubMed2002

Recent temperature trends in the Antarctic.

It is important to understand how temperatures across the Antarctic have changed in recent decades because of the huge amount of fresh water locked into the ice sheet and the impact that temperature changes may have on the ice volume. Doran et al. claim that there has been a net cooling of the entire continent between 1966 and 2000, particularly during summer and autumn. We argue that this result has arisen because of an inappropriate extrapolation of station data across large, data-sparse areas of the Antarctic.

Antarctic Regions↗
PubMed2002

Antecedent hypertension and heart failure after myocardial infarction.

OBJECTIVES: We sought to assess the relationship of antecedent hypertension to neurohormones, ventricular remodeling and clinical heart failure (HF) after myocardial infarction (MI). BACKGROUND: Heart failure is a probable contributor to the increased mortality observed after MI in those with antecedent hypertension. Hence, neurohormonal activation, adverse ventricular remodeling and a higher incidence of clinical HF may be expected in this group. However, no previous report has documented serial postinfarction neurohumoral status, serial left ventricular imaging and clinical outcomes over prolonged follow-up in a broad spectrum of patients with and without antecedent hypertension. METHODS: Inpatient events were documented in 1,093 consecutive patients (436 hypertensive and 657 normotensive) with acute MI. In 68% (282 hypertensive, 465 normotensive) serial neurohormonal sampling and radionuclide ventriculography were performed one to four days and three to five months after infarction. Clinical outcomes were recorded over a mean follow-up of two years. RESULTS: Plasma neurohormones were significantly higher in hypertensives than in normotensives one to four days and three to five months after infarction. From similar initial values, left ventricular volumes increased significantly in hypertensives, compared with normotensives. Left ventricular ejection fraction rose significantly in normotensive but not hypertensive patients. Together with higher inpatient (8.1% vs. 4.4%, p < 0.002) and post-discharge mortality (9.5% vs. 5.5%, p = 0.043), hypertensive patients incurred more inpatient HF (33% vs. 24%, p < 0.001) and more late HF requiring readmission to hospital (12.4% vs. 5.5%, p < 0.001). Antecedent hypertension predicted late HF in patients >64 years of age with neurohormonal activation and early left ventricular dilation. CONCLUSIONS: Antecedent hypertension interacts with age, neurohumoral activation and early ventricular remodeling to confer greater risk of HF after MI.

Age Factors↗
PubMed2002

Social security in Asia and the Pacific: a brief overview.

In terms of numbers of people, the global challenges facing social security systems are largely Asian. Because of rapid population aging in Asia, while it accounted for 28% of the world's population aged 60 and older in 1985, that percentage will more than double to 58% in 2050. Provident funds are a prominent feature of retirement income systems in the region-Asia and the Pacific contain the majority of the world's countries with provident funds. These programs typically provide lump-sum benefits, and thus, do not provide annuity protection against outliving one's resources. Because of the influence of Confucian philosophy with its emphasis on family responsibility for elders, countries in the region have been relatively slow in developing social security programs. China does not have a social security program for workers who do not work for the government or in government-owned enterprises.

Aged↗
PubMed2002

Social security in Africa: a brief review.

Africa is the poorest region of the world and has the youngest and least developed social security programs. Most Africans are not covered by social security programs. The high prevalence of HIV/AIDS in some sub-Saharan countries and internal armed conflicts in others have created difficult problems in some countries for social security programs. As a result, some countries do not have functioning social security programs. The social security programs that do exist in Africa are influenced by their colonial heritage, with the programs in English-speaking Africa differing from those in French-speaking Africa. Six different patterns of social security provision can be identified.

Acquired Immunodeficiency Syndrome↗
PubMed2002

Social security in the Middle East: a brief review.

The countries of the Middle East all have traditional social insurance type social security programs. The move towards defined contribution individual accounts that is occurring in some regions has not affected this region The social security programs in the Middle East are not facing the problems of financing found in Europe and North America, in part because they still have relatively high fertility rates and are thus little affected by population aging. They tend to have low retirement ages and some of the wealthy countries of the region provide very generous benefits. Many of them need to consider reforms that raise retirement ages. A characteristic of many of the social security old-age benefit programs of the region is that they exclude foreign workers, who in some countries account for more than half the workforce.

Age Factors↗