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Biomedical subjects

K A Hunter

Publications and source records attributed to K A Hunter.

At least 19 recordsLinked to original sources
PubMed2006

Adsorption of divalent copper, zinc, cadmium and lead ions from aqueous solution by waste tea and coffee adsorbents.

The adsorption of the divalent cations of Cu, Zn, Cd and Pb by tea leaves and coffee grounds from aqueous solutions is described. Both adsorbents exhibited strong affinity for these ions which could be described by a simple single-site equilibrium model. For coffee, the order of increasing adsorption equilibrium constant K was Cu < Pb < Zn < Cd, while for tea the opposite order was observed indicating that the adsorption sites on each adsorbent have a different chemical nature. Adsorption decreased at low pH < 4 through competition with H+ for adsorption sites, and for all metals except Cu, at high pH > 10, probably because of anion formation in the case of Zn2+ and also increased leaching of metal-binding soluble materials. The effect of metal ion concentration on the adsorptive equilibria indicated a threshold concentration above which overall adsorption became limited by saturation of the adsorption sites. Competition between two metal ions for the same sites was not observed with Cu(II) and Pb(II), however Zn(II) reacted competitively with Cd(II) binding sites on both tea and coffee. If fresh coffee or tea adsorbents were used, the fraction of metal ion taken up by the adsorbent was diminished by the competitive effects of soluble metal-binding ligands released by the tea or coffee. Experiments with coffee showed that roasting temperature controls the formation of metal ion adsorption sites for this adsorbent.

Adsorption↗
PubMed2005

Global iron connections between desert dust, ocean biogeochemistry, and climate.

The environmental conditions of Earth, including the climate, are determined by physical, chemical, biological, and human interactions that transform and transport materials and energy. This is the "Earth system": a highly complex entity characterized by multiple nonlinear responses and thresholds, with linkages between disparate components. One important part of this system is the iron cycle, in which iron-containing soil dust is transported from land through the atmosphere to the oceans, affecting ocean biogeochemistry and hence having feedback effects on climate and dust production. Here we review the key components of this cycle, identifying critical uncertainties and priorities for future research.

Atmosphere↗
PubMed2005

Removal of copper and copper-binding organic ligands during potable water treatment.

The concentrations and chemical speciation of copper before and after potable water treatment have been examined using 3 techniques: a copper ion-selective electrode (Cu-ISE), chemiluminescence (CL) and anodic stripping voltammetry (ASV), together with water quality parameters colour, turbidity and dissolved organic carbon (DOC). As expected, only a small fraction of colour (6.6-11%), turbidity (6.7-14%) and DOC (20%) remained after treatment. The removal of Cu and Cu-binding natural organic matter (NOM) was more variable but still significant: 17-64% of total dissolved Cu and 19-61% of Cu-binding NOM (as determined by ASV) remained after treatment. Labile Cu levels, as measured by CL, were 0-23% after treatment. The Cu-ISE titrations showed significant Cu-binding in raw water in the concentration range 10(-7) to 10(-6) mol l(-1) Cu2+, but very little binding after treatment. The results indicate that conventional water treatment has a significant effect on both total Cu levels and Cu-binding NOM, with implications for Cu2+ speciation and bio-availability, particularly in reticulation systems containing copper pipes.

Copper↗
PubMed2003

Activated eosinophils upregulate the metastasis suppressor molecule E-cadherin on prostate tumor cells.

Cell adhesion molecules (CAMs) play an important role in cancer metastasis by facilitating attachment to vascular endothelia, invasion and spread into secondary tissue sites. We have shown that activated eosinophils (EosA) inhibited the growth of prostate cancer (Pca) cells in vitro. In the present study, we examined the ability of EosA 24 hr conditioned supernatants (EosAcs) to modulate the expression of ICAM-1, VCAM-1, ELAM-1, E-cadherin and N-cadherin expression on human Pca cell lines, Du-145 and PC-3 by flow cytometry. TNF-alpha, IL-10 and IL-12 were also evaluated. ICAM-1, expressed on PC-3 and DU 145 cells, was enhanced by TNF-alpha and IL-10. ELAM-1 was present on DU 145 cells but absent on PC-3. TNF-alpha and IL-10 enhanced ELAM-1 on DU 145, but EosA 24 hr supematants failed to do so. All three cytokines, namely IL-10, IL-12 and TNF-alpha-induced ELAM-1 on PC-3 tumor cells. Although VCAM-1 was absent on DU 145 and PC-3 cells, it was expressed on DU-145 cells after exposure to EosA: tumor cell co-cultures, and was expressed on PC-3 following exposure to IL-10 and IL-12. N-cadherin and E-cadherin were both expressed on DU-145. While N-cadherin was expressed on PC-3 cells, E-cadherin was not. N-cadherin was enhanced on DU-145 and PC-3 cells following exposure to EosA co-culture and upregulated on PC-3 by IL-10 and EosA 24 hr supernatants, but decreased by IL-12. E-cadherin was up-regulated on DU 145 cells following co-culture with EosA and was induced on PC-3 by IL-10 and IL-12, but not by EosA co-culture and 24 hr supematants. In conclusion, inflammatory and non-inflammatory cytokines modulate CAM expression on Pca cells; EosA and EosA 24 hr supernatants also exerted modulatory activity of CAM expression. Most significantly, the metastasis suppressor molecule, E-cadherin was enhanced on DU 145 cells by EosA and induced on PC-3 by IL-10 and IL-12 both of which are produced by EosA. This suggests potential use of these cytokines in immunotherapeutic strategies for prostate cancer and its metastasis.

Cadherins↗
PubMed2003

Eosinophils in a tri-cell multicellular tumor spheroid (MTS)/endothelium complex.

Eosinophils have been found in infiltrates of many different cancers. It is still unclear as to whether they are passive bystanders in the cellular milieu or active cellular agents in host responses. Thus their harmful or helpful nature remains equivocal. We have developed an in vitro tri-cell model of eosinophils, MCF-7 breast tumor cell spheroids and HUVEC endothelial cells to examine the binding and association of eosinophils with both the tumor and the endothelia and the ensuing action of the tumor. Eosinophils bound very rapidly to the tumor spheroid and remained tightly bound throughout the 24 hr culture period. Histological staining of the tri-cell complex revealed highly granulated eosinophils as well as large amounts of degranulated protein diffused throughout the spheroid. IL-5 treatment of eosinophil: MTS complexes resulted in destruction of the tumor cells, particularly those which had grown out from the spheroid onto the endothelial cells. Eosinophils, pretreated with IL-5 before interaction with the tumor or endothelial cells, bound aggressively to the endothelial cells, thereby preventing tumor attachment. This eosinophil tri-cell tumor model system mimics clinical observations with regards to binding to epithelial and endothelial cells, dispersal of granular proteins throughout the tumor and also tumor destruction. Because it closely mirrors in vivo cellular interactions, it allows one to study more closely the mechanism(s) of eosinophil killing, the modulation of eosinophil activity and the testing of therapeutic interventions. The accommodation of the model to tumor invasion, using metastatic tumor cells and extracellular matrices such as matrigel, will help to elucidate a role for eosinophils (and their mediators) in cancer invasion and metastasis.

Breast Neoplasms↗
PubMed2001

Effects of smoking and abstention from smoking on fibrinogen synthesis in humans.

Cigarette smoking and hyperfibrinogenaemia are both significant risk factors for the development of cardiovascular disease. Two studies are described here which aimed to establish the metabolic mechanism responsible for the raised plasma fibrinogen concentration observed in smokers. Chronic smokers had a significantly elevated absolute rate of fibrinogen synthesis (ASR) compared with non-smokers (22.7 +/- 1.3 mg/kg per day versus 16.0 +/- 1.3 mg/kg per day; means +/- S.E.M., P < 0.01), with plasma levels of fibrinogen significantly correlated with fibrinogen synthesis (r = 0.65, P = 0.04). Unlike fibrinogen, plasma albumin concentrations were lower in smokers than in non-smokers (45 +/- 0.4 versus 47 +/- 0.7 g/l, P < 0.05), but there was no difference in rates of albumin synthesis between the two groups. Two weeks cessation from smoking by previously chronic smokers was associated with a rapid and marked fall in plasma fibrinogen concentration (from 3.06 +/- 0.11 g/l to 2.49 +/- 0.14 g/l, P < 0.001), and a significant reduction in ASR (a 33% reduction, from 24.1 +/- 1.7 to 16.1 +/- 1.0 mg/kg per day, P < 0.001). These studies suggest a primary role for increased synthesis in producing the hyperfibrinogenaemia associated with smoking. Moreover, abstention from smoking for a period of only 2 weeks induces a significant decrease in the rate of fibrinogen synthesis by the liver, with a concomitant reduction in the plasma fibrinogen concentration.

Adult↗
PubMed2001

Effect of diets rich in oleic acid, stearic acid and linoleic acid on postprandial haemostatic factors in young healthy men.

The aim of the present study was to investigate the effects of stearic acid-, oleic acid- and linoleic acid-rich meals on postprandial haemostasis in young healthy volunteers whose background diets had been controlled for 14 d in a residential study. Six healthy male volunteers were assigned randomly to consume diets rich in stearic acid, oleic acid or linoleic acid for 14 d. On day 15, plasma lipids and haematological variables were measured in the fasted state, and 3 and 7 h (factor VII and prothrombin activation peptide fragments, 1 and 2 only) after consumption of a test meal. Test meals provided 40 % of the subjects' daily energy requirement, with 41 % of the energy provided as fat, 17 % energy as protein and 42 % energy as carbohydrate. The mean fat content of the meal was 45 (sd 5) g. Significant alterations from fasted values were observed for activated factor VII after 7 h), factor VII antigen after 7 h), prothrombin activation peptide fragments 1 and 2 after 7 h) and plasminogen activator inhibitor type 1 activity after 3 h) after consumption of each of the three meals. No significant differences were observed in haemostatic values (factor VII coagulant activity, factor VII antigen, tissue plasminogen activator activity prothrombin activation peptide fragment and plasminogen activator inhibitor type-1) with regard to diet except for activated factor VII at 3 h; values were higher after the oleic acid- and linoleic acid-rich meals than after the stearic acid-rich meal After consumption of each of the three meals, chylomicrons contained proportionately more palmitic acid than the lipids ingested. The present study shows that there are demonstrable changes in postprandial haemostasis when young healthy volunteers with controlled dietary backgrounds are challenged with a physiological fat load. These changes are independent of the fatty acid composition of the test meals.

Adult↗
PubMed2000

Methyl mercury bioaccumulation in long-finned eels, Anguilla dieffenbachii, from three rivers in Otago, New Zealand.

This research focuses on mercury (Hg) bioaccumulation in New Zealand long-tinned eels (Anguilla dieffenbachii) from the aquatic environment. Total Hg (HgT) and methyl mercury (MeHg) concentrations were determined in muscle tissue from eels living in three South Island rivers dominated respectively by urban, native bush and agricultural land-uses. Most of the Hg in eels was MeHg (> 84%) and the MeHg concentrations increased linearly with both length and eel age for a given river habitat. The annual growth rates for eels from the urban and agricultural streams were greater than for eels from the native bush stream. The average MeHg accumulation rate was significantly higher for the eels in the agricultural stream compared with either the urban or native bush catchments. These results are probably due to a combination of factors and further investigations in the lower food web are necessary to elucidate the exact mechanisms of MeHg bioaccumulation in these creatures.

Age Factors↗
PubMed1999

The effects of structurally defined triglycerides of differing fatty acid composition on postprandial haemostasis in young, healthy men.

The aim of this study was to investigate whether a number of key haemostatic factors were altered when healthy young individuals were challenged with a fat load of physiological size contained within a meal composed of normal ingredients and whether this response was modified when the fatty acid composition of the meal was altered radically. Eight healthy male volunteers each randomly consumed four meals which were identical in terms of gross nutritional content (41% of energy provided as fat, 17% as protein and 42% as carbohydrate) but which differed in fatty acid composition. To reduce the possible influence of fatty acid position within the triglyceride molecule on lipid absorption and subsequent metabolic effects, the structural integrity of 91% of fat (test triglycerides such as 1,3 distearoyl-2-oleoyl glycerol (S-O-S), trioleine (O-O-O), and 1,3 dilinoleoyl-2-oleoyl glycerol, (L-O-L)) in the meals was controlled so that the principal fatty acid in the sn-2 position was oleic acid (18:1n-9). Meals rich in either a test triglyceride or a control oil provided 44+/-6 g of fat. No significant alterations from fasted values of elevated plasma factor VII coagulant activity (FVIIc) or F1 + 2 were observed. FVIIA varied significantly over the postprandial time course; however, when expressed as a percentage of the fasting value, the FVIIa responses to O-O-O and L-O-L differed significantly but this was not evident when the absolute values were analysed. Similarly, no difference in plasma fibrinopeptide A (FPA) concentrations were evident. After all four meals, chylomicron contained proportionately more palmitic acid and generally less oleic acid than the ingested lipids. This study clearly demonstrates that postprandial haemostatic responses of young healthy individuals to a physiological fat load are minimal, (irrespective of triglyceride structure).

Adult↗
PubMed1996

Pharmaceutical care applied to the hospice setting: a cancer pain model.

A review of the concept of pharmaceutical care applied to the hospice setting with emphasis on the management of cancer pain. Traditionally pharmacists involved in hospice care have acted in a distributive function and as an information resource. The advantages of having a hospice pharmacist practicing pharmaceutical care are many and include enhanced patient quality of care through monitoring patient outcomes, establishing drug therapy protocols, enhanced patient compliance through patient education, better pain and symptom control, and staff education. Monitoring therapeutic outcomes starts with chart reviews to collect all relevant information and attending patient care conferences to obtain information concerning the patient's condition. Once this is done, a patient-specific drug-related problem list is formulated, and from this list, desired therapeutic outcomes and alternatives are established to monitor therapy and to insure the drug is producing the desired effect. Pharmaceutical care fits well with the concept of hospice care, which has as its primary purpose maintaining the quality of life in the terminal patient. There is no portion of caring for the terminally ill patient that is more important than the management of pain. As a result of implementing the concept of pharmaceutical care in the hospice setting for cancer patients, pain can be managed in an effective and compassionate way. By monitoring treatments and eliminating medication-induced problems, the pharmacist becomes a valuable member of the health care team in the management of terminally ill patients. This in turn increases the quality of care as well as the quality of life for the hospice patient.

Hospice Care↗
PubMed1996

Pharmaceutical care for home-dwelling elderly persons: a determination of need and program description.

To determine the need for pharmaceutical care services within a community-based, case management program for elders, an assessment of medication, health, and functional status was completed by a pharmacist on 49 home-dwelling older adults. The goal of this assessment was to support the need for pharmacists as members of multidisciplinary teams that provide comprehensive, in-home care for elderly persons. Pharmacists can identify drug misadventures that have the potential to lead to loss of independent living status, hospital admissions, and death. This article describes this program and the results of the assessment that supported the decision to include a pharmacist on the multidisciplinary team.

Activities of Daily Living↗
PubMed1995

Acute stimulation of albumin synthesis rate with oral meal feeding in healthy subjects measured with [ring-2H5]phenylalanine.

1. The short-term effect of oral feeding on albumin synthesis rate was investigated in 12 healthy volunteers using two meal regimens. Albumin synthesis was measured over 90 min after injection of a 'flooding' amount (43 mg/kg body weight) of phenylalanine enriched to 7.5, 10 or 15 atoms % with the stable isotope [ring-2H5]phenylalanine. 2. In one set of subjects, consumption of five small hourly meals resulted in a consistent and significant increase (P < 0.05) in albumin fractional synthesis rate from a mean (+/- SEM) fasting value of 5.8 (+/- 0.4)%/day to 7.1 (+/- 0.4)%/day in the fed state. 3. A second study in which albumin synthesis was measured 30 min after consumption of a single larger meal was carried out in another set of volunteers. The fractional rate of albumin synthesis was again significantly elevated after feeding (P < 0.05), rising from 7.1 (+/- 0.4)%/day in the fasted state to 9.1 (+/- 0.6)%/day in the fed state. In both studies, similar responses were observed in the absolute rate of albumin synthesis (mg day-1 kg-1). 4. Albumin secretion time was significantly shorter (P < 0.05) after feeding in both studies, suggesting that the acute stimulation in albumin synthesis observed after feeding may in part be mediated via a post-transcriptional mechanism. 5. The response of total liver protein synthesis to oral feeding was investigated in an animal model employing adult rats studied with a flooding amount of [2,6-3H]phenylalanine.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1994

Pharmacist provided education and counseling for managing pediatric asthma.

A program to promote and assess the provision of family directed counseling by pharmacists on the understanding of pediatric asthma is discussed. The program consisted of two questionnaires separated by an educational intervention program. The initial questionnaire was developed to evaluate participants' understanding of asthma and its management. The aim of the intervention program was to improve this understanding through counseling, demonstration, and sharing of families' experiences with asthma. The second questionnaire assessed post-intervention knowledge including short-term retention of information. Before the intervention, few participants (14%) indicated that they were counseled by a pharmacist about the safe and effective use of asthma medications. Seventy-nine percent indicated that more information would aid them in better understanding asthma and possibly better controlling their child's illness. After the intervention, participants were able to correctly answer questions about asthma and medications used to manage the disease 78% of the time. This program offers one method for pharmacists to become involved in patient care through the provision of education and counseling. It also provides an avenue to encourage patients and their families to gain a deeper understanding of asthma and its management.

Adolescent↗
PubMed1977

Specific patterns of inflicted burn injuries.

By retrospective review of 1,061 charts and prospective analysis of all accidental injuries seen in a Pediatric Emergency Room over a 5-year period, criteria were developed to identify the source of an injury as either specific or nonspecific, i.e., whether a unique causative mechanism was clear or not from the clinical or radiologic signs. These criteria were then used to diagnose 712 cases of child abuse, of which 43 were burns. There were four specific burn patterns. Readily evident were contacts with hot objects; the other were caused by various applications of hot liquids. In these latter cases, the position of the body at the time of burning could be precisely detected by analysis of the depth, configuration, distribution of the burns, and the reciprocal relation to flexion creases and joints of the spared areas. This information is a powerful tool for assessing the veracity of the history presented by the child's caretaker when considering a diagnosis of child battery.

Burns↗
PubMedDate not supplied

Pharmacist-managed intravenous to oral step-down program.

In an effort to provide cost-effective pharmaceutical care at a 650-bed community hospital, a pharmacist-managed intravenous to oral step-down program was developed and implemented. As part of this program, satellite pharmacists review daily the charts of patients receiving 1 or more of 10 targeted drugs given intravenously. Based on a predetermined set of criteria and their clinical judgment, pharmacists recommend that physicians switch to the oral formulation of the targeted drugs if appropriate. This program has been in place for 7 months, during which time 223 recommendations were made. Of these recommendations, 190 were accepted and implemented, resulting in a cost savings of $21,596.00. When annualized, the expected savings is $37,000.00 or nearly the salary of one full-time pharmacist. This program has been well accepted by physicians and pharmacists. It appears to be having a positive impact on physician awareness of using oral medications when appropriate.

Administration, Oral↗