Antiphospholipid antibodies in dogs with immune mediated hemolytic anemia, spontaneous thrombosis, and hyperadrenocorticism.

BACKGROUND: The pathophysiology of thrombus formation in canine IMHA and other diseases remains unclear. Antiphospholipid antibodies (aPL) are an important cause of thrombosis in humans and might cause thrombosis in dogs. HYPOTHESIS: Dogs with IMHA, spontaneous thrombosis, and hyperadrenocorticism will have increased levels of aPL and lupus anticoagulants (LA), compared with healthy and sick dogs. ANIMALS: Thre aPL were measured in healthy controls (n = 40-45); sick dogs without thrombosis (n = 86); IMHA (n = 37); spontaneous thrombosis (ST, n = 11); and hyperadrenocorticism (n = 17). Four groups of dogs were also tested for the presence of LA: healthy controls (n = 40); sick dogs without thrombosis (n = 13); IMHA (n = 13); and ST (n = 5). METHODS: Prospective cohort study. Dogs were tested for aPL by an ELISA and for LA by the dilute Russell's Viper venom time (dRVVT). Median values were compared by Kruskal-Wallis (aPL) or ANOVA (LA), and an odds ratio for development of thrombosis in dogs positive for aPL was calculated. RESULTS: aPL are uncommon in healthy dogs. A total of 13/86 sick dogs without thrombosis, 7/37 dogs with IMHA, 1/11 dogs with ST, and 3/17 dogs with HAC were positive for protein binding-dependent aPL. There was no significant difference in the number of dogs positive for aPL for any of the study groups, and there was no increased risk for thrombosis in dogs positive for aPL. No dogs had LA. CONCLUSIONS: Our preliminary research does not support a strong role for aPL for the development of thrombosis in dogs with IMHA and other thrombotic diseases, although future studies are warranted.

Aliskiren reduces vascular pathology in diabetic retinopathy and oxygen-induced retinopathy in the transgenic (mRen-2)27 rat.

AIM/HYPOTHESIS: We examined whether the renin inhibitor, aliskiren, provides similar or greater protection than ACE inhibition from non-proliferative diabetic retinopathy and from the proliferative neoangiogenesis of oxygen-induced retinopathy. METHODS: Transgenic (mRen-2)27 rats, which overexpress mouse renin and angiotensin in extra-renal tissues, were studied. For diabetic studies, non-diabetic, diabetic (streptozotocin, 55 mg/kg), diabetic + aliskiren (10 mg kg(-1) day(-1), pump), or diabetic + lisinopril (10 mg kg(-1) day(-1), drinking water) rats were evaluated over 16 weeks. For oxygen-induced retinopathy studies, rats were exposed to 80% oxygen (22 h/day) from postnatal days 0 to 11, and then room air from postnatal days 12 to 18. Aliskiren (10 or 30 mg kg(-1) day(-1), pump) or lisinopril (10 mg kg(-1) day(-1), drinking water) was administered during retinopathy development between postnatal days 12 and 18. RESULTS: Systolic BP in diabetic (mRen-2)27 rats was reduced with 10 mg kg(-1) day(-1) aliskiren, but only lisinopril normalised systolic blood pressure. In diabetic (mRen-2)27 rats, 10 mg kg(-1) day(-1) aliskiren and lisinopril reduced retinal acellular capillaries and leucostasis to non-diabetic levels. In oxygen-induced retinopathy, neoangiogenesis and retinal inflammation (leucostasis, ED-1 immunolabelling) were partially reduced by 10 mg kg(-1) day(-1) aliskiren and normalised by 30 mg kg(-1) day(-1) aliskiren, whereas lisinopril normalised neoangiogenesis and reduced leucostasis and ED-1 immunolabelling. Aliskiren and lisinopril normalised retinal vascular endothelial growth factor expression; however, only aliskiren reduced intercellular adhesion molecule-1 to control levels. CONCLUSIONS/INTERPRETATION: Aliskiren provided similar or greater retinal protection than ACE inhibition and may be a potential treatment for diabetic retinopathy.

Corticosteroid-binding globulin regulates cortisol pharmacokinetics.

OBJECTIVE: Corticosteroid-binding globulin (CBG) is the principal carrier for cortisol in the circulation. Variations in CBG-binding capacity are predicted to alter total serum cortisol disposition, but free serum cortisol is believed to be unaffected. Unbound cortisol pharmacokinetics (PK) have not been studied in the context of CBG changes. We aimed to assess the regulation of cortisol PK by CBG. DESIGN AND SUBJECTS: Women on oestrogens [oral contraceptive pill, (OCP)], patients homozygous for a nonfunctioning CBG variant (CBG null) and healthy controls (HV) were studied before and after IV and oral administration of hydrocortisone 20 mg. MEASUREMENTS: PK parameters were studied for total serum cortisol (SerF), free serum cortisol (FreeF) and cortisone (FreeE), and salivary cortisol (SalF) and cortisone (SalE): area under the curve (AUC), clearance (CL), half-life and volume of distribution (V(d)). RESULTS: Following IV hydrocortisone, AUC and half-life of SerF were significantly higher in the OCP group and lower in the CBG null. SerF CL and V(d) were significantly lower in the OCP group and increased in the CBG null, compared to HV. PK parameters for FreeF and the salivary biomarkers were not different between the CBG null and HV, although OCP patients still had higher AUC compared to HV and prolonged half-life. These findings were confirmed following oral hydrocortisone, but concentration-time profiles were highly heterogeneous and SalF interpretation was problematic because of oral contamination. CONCLUSIONS: We have demonstrated that CBG has a distinct effect on cortisol PK. When CBG binding is disrupted, FreeF retains normal PK characteristics, although CBG null patients lack a CBG-bound pool of readily releasable cortisol. Women on oestrogens may have altered free serum cortisol kinetics and thus may be potentially overexposed to glucocorticoids.

Anemia is associated with decreased survival time in dogs with lymphoma.

BACKGROUND: Anemia is a common complication in human patients with neoplasia and has been associated with decreased survival time and a poorer quality of life. HYPOTHESIS: The presence of anemia at diagnosis is negatively associated with survival and remission times in dogs with lymphoma, but not in dogs with osteosarcoma. ANIMALS: Eighty-four dogs with lymphoma and 91 dogs with osteosarcoma that presented for treatment at the Animal Cancer Center, Colorado State University. METHODS: Retrospective, case-control study. Medical records were reviewed to determine the presence or absence of anemia (PCV < 40) at initial presentation. Median survival and remission times were identified by the Kaplan-Meier product limit method and the association between anemia and survival was determined by a multivariable Cox proportional hazard regression analysis. RESULTS: Cancer-related anemia is more frequent in dogs with lymphoma than in control dogs or dogs with osteosarcoma. Dogs with lymphoma and anemia had a significantly decreased survival time compared with dogs without anemia. There was no effect of anemia on remission time in dogs with lymphoma. Anemic dogs with osteosarcoma did not have decreased survival or remission time compared with nonanemic dogs with osteosarcoma. CONCLUSIONS AND CLINICAL IMPORTANCE: Shortened survival time in dogs with lymphoma and anemia at initial presentation has important prognostic significance. Understanding cancer-related anemia in dogs might offer new opportunities to improve quality of life and survival times in these patients.

Protein cross-linking in food.

The aims of this paper are (1) to probe the relationship between molecular structure and protein cross-linking ability for a range of small molecules; (2) to establish whether this relationship holds within a food matrix; and (3) to test the impact of Maillard cross-linking on food functionality, particularly texture, in wheat- and soy-based food systems. A variety of molecules were obtained, either commercially or via organic synthesis. Cross-linking ability was tested using our standard model system, employing ribonuclease A and analyzing the results by SDS-PAGE. Molecules of varying reactivity were tested in wheat- and soy-based products, and the changes in functionality were correlated with changes in protein cross-linking. No simple relationship was found between molecular structure and ability to cross-link ribonuclease. Only the most reactive reagents were able to cross-link within the food matrix. Nevertheless, a low degree of cross-linking was shown to have significant consequences on the properties of wheat- and soy-based foods, suggesting that the Maillard reaction may represent a means to control food texture.

The photoreduction of H(2)O(2) by Synechococcus sp. PCC 7942 and UTEX 625.

It has been claimed that the sole H(2)O(2)-scavenging system in the cyanobacterium Synechococcus sp. PCC 7942 is a cytosolic catalase-peroxidase. We have measured in vivo activity of a light-dependent peroxidase in Synechococcus sp. PCC 7942 and UTEX 625. The addition of small amounts of H(2)O(2) (2.5 microM) to illuminated cells caused photochemical quenching (qP) of chlorophyll fluorescence that was relieved as the H(2)O(2) was consumed. The qP was maximal at about 50 microM H(2)O(2) with a Michaelis constant of about 7 microM. The H(2)O(2)-dependent qP strongly indicates that photoreduction can be involved in H(2)O(2) decomposition. Catalase-peroxidase activity was found to be almost completely inhibited by 10 microM NH(2)OH with no inhibition of the H(2)O(2)-dependent qP, which actually increased, presumably due to the light-dependent reaction now being the only route for H(2)O(2)-decomposition. When (18)O-labeled H(2)O(2) was presented to cells in the light there was an evolution of (16)O(2), indicative of H(2)(16)O oxidation by PS 2 and formation of photoreductant. In the dark (18)O(2) was evolved from added H(2)(18)O(2) as expected for decomposition by the catalase-peroxidase. This evolution was completely blocked by NH(2)OH, whereas the light-dependent evolution of (16)O(2) during H(2)(18)O(2) decomposition was unaffected.

Career pathways in dentistry.

During the next decade we are likely to see the greatest changes in the way in which dentistry is delivered than at any point since the introduction of the National Health Service in 1948. The move in the primary-care sector from a mainly NHS service to a mixed economy, the emergence of more practices operated by bodies corporate and the possibility of high-street specialists will all impact on every aspect of professional life. For those trying to plan a career or looking to change pathways it can be difficult to identify which pathway to follow. The purpose of this article is to explore the possible routes for career development.

Accounting for evil and cruelty: is to explain to condone?

Analysts of evil and violence express the concern that to explain harmdoing may result in a condoning attitude toward perpetrators. An examination of research relevant to this hypothesis suggests that there are a variety of cognitive and affective processes that may produce a relatively condoning attitude toward perpetrators as a result of explaining their actions. Evidence from 3 exploratory studies supported the exonerating effects of explanations. Participants generating explicit explanations of harmdoing displayed a more condoning attitude toward pelpetrators than did those forming impressions of perpetrators without first explaining the acts. Participants reading social-psychological explanations of harmdoing also judged the researcher to be more condoning of perpetrators than those reading dispositional explanations of the same behavior. Implications of these findings are discussed.

Placental weight, birth measurements, and blood pressure at age 8 years.

OBJECTIVE: To examine relationships between blood pressure during childhood and both placental weight and body size at birth, in an Australian population. DESIGN: A follow up study of a birth cohort, undertaken when cohort members were aged 8 years. SETTING: Adelaide, South Australia. SUBJECTS: 830 children born in the Queen Victoria Hospital in Adelaide, South Australia, during 1975-6. MAIN OUTCOME MEASURES: Systolic and diastolic blood pressure measured when the children were aged 8 years. RESULTS: Blood pressure at 8 years was positively related to placental weight and inversely related to birth weight, after adjusting for the child's current weight. For diastolic pressure there was a decrease of 1.0 mm Hg for each 1 kg increase in birth weight (95% confidence interval (CI) = -0.4 to 2.4) and an increase of 0.7 mm Hg for each 100 g increase in placental weight (95% CI = 0.1 to 1.3). Diastolic pressure was also inversely related to chest circumference at birth, independently of placental weight, with a decrease of 0.3 mm Hg for each 1 cm increase in chest circumference (95% CI = 0.2 to 0.5). CONCLUSIONS: These findings are further evidence that birth characteristics, indicative of fetal growth patterns, are related to blood pressure in later life.

Junctional permeability measurements in the embryonic chick lens.

The purpose of this paper is two-fold: to measure junctional permeability of different types of dissociated lens cells and to compare the junctional permeability of dissociated lens cells to that of cells in the intact lens. Dissociated embryonic chick lens cells and intact embryonic chick lenses were loaded with the fluorescent dye 5,6 carboxyfluorescein diacetate. The return of fluorescence after bleaching an individual cell was used to estimate cell-to-cell permeability. Use of the confocal microscope facilitated quantitation of the return of fluorescence as well as optical sectioning needed to measure cell-to-cell permeability in an intact lens. Two types of dissociated cells were studied: spherical and short elongated cells. The average rate constant for 5,6 carboxyfluorescein transfer between these cells was 7.9 x 10(-3) sec-1 and 8.1 x 10(-3) sec-1, respectively. The junctional permeability for both types of cells was reduced by lowering internal pH to 6.0 by bathing the cells in a sodium acetate solution. Permeability measurements of the central epithelial cells of an isolated whole lens gave an average rate constant of 2.6 x 10(-3) sec-1, comparable to the rates measured in the dissociated cells. These results establish that the photobleach method can be used in intact lens to quantitatively assess junctional permeability and that dissociated epithelial cells have very nearly the same junctional permeabilities as cells in the intact lens.

Conversion of a delayed rectifier K+ channel to a voltage-gated inward rectifier K+ channel by three amino acid substitutions.

Single, double, and triple mutations progressively shift Shaker activation to more hyperpolarized potentials, resulting in an increase in the fraction of inactivated channels at negative resting voltages. The most negatively shifted mutation, the triple mutant, behaves like an inward rectifier. What is usually considered activation of an inward rectifier is, for the triple mutant, recovery from inactivation, and what is usually considered deactivation is inactivation. This conversion from outward rectifier to inward rectifier does not rely on a difference in sign or direction of charge movement of the voltage sensor, since activation of the Shaker outward rectifier is due to a different gate than activation of the triple mutant inward rectifier. Other voltage-dependent inward rectifiers in the Shaker family may work by a similar mechanism.

Characterization of the non-photochemical quenching of chlorophyll fluorescence that occurs during the active accumulation of inorganic carbon in the cyanobacterium Synechococcus PCC 7942.

Previous work has shown that the maximum fluorescence yield from PS 2 of Synechococcus PCC 7942 occurs when the cells are at the CO2 compensation point. The addition of inorganic carbon (Ci), as CO2 or HCO3 (-), causes a lowering of the fluorescence yield due to both photochemical (qp) and non-photochemical (qN) quenching. In this paper, we characterize the qN that is induced by Ci addition to cells grown at high light intensities (500 µmol photons m(-2) s(-1)). The Ci-induced qN was considerably greater in these cells than in cells grown at low light intensities (50 µmol photons m(-2) s(-1)), when assayed at a white light (WL) intensity of 250 µmol photons m(-2) s(-1). In high-light grown cells we measured qN values as high as 70%, while in low-light grown cells the qN was about 16%. The qN was relieved when cells regained the CO2 compensation point, when cells were illuminated by supplemental far-red light (FRL) absorbed mainly by PS 1, or when cells were illuminated with increased WL intensities. These characteristics indicate that the qN was not a form of energy quenching (qE). Supplemental FRL illumination caused significant enhancement of photosynthetic O2 evolution that could be correlated with the changes in qp and qN. The increases in qp induced by Ci addition represent increases in the effective quantum yield of PS 2 due to increased levels of oxidized QA. The increase in qN induced by Ci represents a decrease in PS 2 activity related to decreases in the potential quantum yield. The lack of diagnostic changes in the 77 K fluorescence emission spectrum argue against qN being related to classical state transitions, in which the decrease in potential quantum yield of PS 2 is due either to a decrease in absorption cross-section or by increased 'spill-over' of excitation energy to PS 1. Both the Ci-induced qp (t 0.5<0.5 s) and qN (t 0.5≃1.6 s) were rapidly relieved by the addition of DCMU. The two time constants give further support for two separate quenching mechanisms. We have thus characterized a novel form of qN in cyanobacteria, not related to state transitions or energy quenching, which is induced by the addition of Ci to cells at the CO2-compensation point.

A typology of mother-daughter relationship patterns for young adult women and their mothers.

Qualitative and quantitative methods were used in this study of developmental themes in the context of the mother-daughter relationship. Semistructured interviews were conducted with 60 women, aged 23-42 years. A rating guide for individuation was developed for content analysis of interview material. The dimensions of the rating guide included (1) psychological autonomy from family of origin, (2) empathy, (3) tolerance of ambiguity, and (4) maintenance of self-esteem. Cluster analysis was employed to assign women with similar individuation profiles into five groups. A typology was constructed that represents styles of mother-daughter interaction. The study findings suggest that typological differences based on individuation themes can be used to describe overall patterns of the mother-daughter relationship over time. These patterns provide a useful context in which to study mother-daughter interactions through the life span.

Family nurse practitioner clinical competencies in alcohol and substance use.

The prevalence of substance use among patients presenting to primary health care settings mandates clinical competency in the area for nurse practitioners (NPs). An educational intervention with an evaluation component is described. The effect of incorporating substance use content into a Family Nurse Practitioner (FNP) curriculum was tested with a convenience sample of 16 FNP students and 8 practicing NPs. Students' knowledge increased significantly; however, differences in students' and practicing NPs' knowledge did not reach significance. Students' clinical competency increased significantly, as demonstrated by standardized patient clinical evaluations, and was significantly better than the practicing NPs in the skill domains of evaluation and record keeping. Educational intervention can improve NP identification of substance-abusing patients in primary health care settings.

Diurnal urinary volume and uranium output in uranium workers and unexposed controls.

Volume and uranium content were determined in individual urine voids over a 76-h (3.25-d) period from six unexposed normal male subjects and three male uranium workers. Uranium analyses were accomplished by a newly developed high-precision kinetic phosphorescence analysis technique with a lower level of detection of 0.007 ng mL-1. Urinary uranium concentrations in individual voids varied by a factor of 2 or less for any one unexposed subject, although there was an order of magnitude variation among the group of unexposed men. The fractional urinary volume excreted in the "standard" so-called simulated 24-h sample was the same for both the unexposed and exposed groups and averaged 0.42 +/- 0.13 of the total daily urine volume. The fraction of uranium in the simulated 24-h samples was 0.43 +/- 0.15 in the unexposed group but only 0.31 +/- 0.13 in the uranium worker group, suggesting that the use of the simulated 24-h urine sample would underestimate the total daily urinary uranium output by approximately a factor of 2 in the uranium workers. Daily urinary excretion relative to intake from drinking water (essentially equal to the gastrointestinal uptake fraction) among the unexposed group ranged from 0.002-0.028, averaging 0.011 +/- 0.008, with an indication that the gastrointestinal uptake factor was inversely proportional to total intake via drinking water.

Single-membrane and cell-to-cell permeability properties of dissociated embryonic chick lens cells.

Ion channels are believed to play an important role in the maintenance of lens transparency. In order to ascribe junctional and nonjunctional permeability properties to specific lens cell types, embryonic chick lenses were enzymatically dissociated into cell clusters, cell pairs and single cells, and both cell-to-cell and single-membrane permeability properties were characterized with the patch-clamp technique. Double patch-clamp experiments and single patch-clamp experiments with Lucifer yellow in the pipette demonstrated that the cells in the dissociated preparation were well coupled, the average conductance between pairs being 42 +/- 27 nS. Double patch-clamp experiments also revealed single cell-to-cell channel events with a predominant unitary conductance of 286 +/- 38 pS. Whole-cell measurements of surface membrane conductance indicate heterogeneity within the population of dissociated embryonic chick lens cells: 63% of the cells have a voltage-independent leak current, 14% of the cells have a potassium-selective inward-rectifier current, and 23% of the cells have a current which turns off with positive voltage on a time scale on the order of seconds. The time constant for this turnoff is voltage dependent.