Clinical implications of inflammation in young children.
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Biomedical subjects
Publications and source records attributed to M Silverman.
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This exploratory study of 205 older adults with chronic illness, of whom 55 enrolled in Medicare HMOs, examined the characteristics of those who enrolled, their experiences with managed care, and the differences between African Americans and whites in these domains. HMO enrollees were more likely to report their finances as inadequate; to have a high school education or less; and to have higher levels of social support. No significant differences by race were found in enrollment or in factors related to enrollment. Enrollees joined because of low premiums, enhanced HMO benefits, and pressure from employers providing retiree health benefits. The majority of enrollees reported positive experiences, however, more whites than African Americans reported negative experiences.
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The PCR technique often yields nonspecific products. To overcome this problem, a simple, specific and efficient method was designed: touch-up and loop incorporated primers (TULIPS)-PCR. This approach utilizes loop primers (i.e., additional nontemplate 5' sequence that self-anneals to the 3' region and inhibits initiation of polymerization). Upon heating of the reaction, the primers melt, initiating hot start. The reaction also uses touch-up pre-cycling with gradual elevation in annealing temperatures to ensure correct pairing. The method has been validated with glyceraldehyde-3-phosphate dehydrogenase (GAPD) primers, and its general applicability is demonstrated by specific amplification of the human gelatinase A transgene from genomic DNA extracted from transgenic mice tails. The TULIPS-PCR protocol is a novel method. The self-annealing primers utilized in this method offer improved specificity and more robust synthesis compared with touch-down and manual hot start PCR. It is performed without the need to open, pause or add to the reaction mixture any nonrectant components, such as wax, antibody or nonspecific dsDNA.
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We tested the hypothesis that changes in phosphorylation of the sarcoplasmic reticulum (SR) protein, phospholamban (PIB) and myofibrillar proteins troponin I (TnI) and C protein are responsible for the decreased relaxant response to isoproterenol in cardiac hypertrophy and failure induced by ascending aortic banding in rats. In isolated perfused heart preparations under maximal isoproterenol stimulation, the capacity for in vitro cAMP-dependent phosphorylation of PIB was significantly increased at the compensatory stage of hypertrophy (126-130%, P<0.001), but decreased with failure (70-76%, P<0.001). Phosphorylation of TnI also decreased in the failing hearts, however to a lesser extent (80-83%, P<0.05). No significant hypertrophy-related difference was evident in isoproterenol-induced phosphorylation of C protein. The relative tissue level of PIB was increased (150-168%, P<0.001) in hypertrophied and decreased (71-83.8%, P<0.05) in failing hearts compared with the respective age-matched sham-operated controls (100%). As a percentage above baseline, the maximal isoproterenol-induced increase in the EC50 of the SR Ca2+ pump in response to phosphorylation of PIB was 38.5+/-1.1% for sham-operated rats, and 26.0+/-3.8% and 15.4+/-4.2% for hypertrophied and failing hearts respectively. As a consequence, linear correlation was observed between the maximal increase in EC50 and the maximal rate of relaxation [(-dP/dt)/DevP] upon isoproterenol stimulation, declining with progressive hypertrophy to failure. These data suggest that hypertrophy-induced alterations in PIB phosphorylation and protein level contribute to the diminished relaxant response of the hypertrophied and failing heart to adrenergic agonists.
The cyclin-dependent kinase inhibitor p27 is a negative regulator of the transition from G1 to S phase of the cell cycle, protects against inflammatory injury and promotes epithelial differentiation. Because p27 protein has been shown to be abnormally expressed both in dysplasia associated with Barrett's esophagus and in sporadic colorectal adenomas, we used immunohistochemistry to evaluate p27 expression in inflammatory bowel disease (IBD)-associated dysplasia and carcinomas. Normal, inflamed, and transitional mucosa, sporadic adenomas, and sporadic colonic carcinomas were studied as controls. In normal colonic epithelium p27 expression was restricted to the superficial, terminally differentiated cells. In colitic and inflamed diverticular mucosa p27 was expressed in the base of the crypts in 86 and 70% of cases, respectively. Similarly, in transitional mucosa adjacent to sporadic carcinomas p27 was expressed in the base of the crypts in all cases. Strong p27 expression extended more frequently from the base of the crypts to superficial cells in IBD-associated dysplasia than in sporadic adenomas (P < 0.007). Twenty of 20 (100%) IBD-associated carcinomas showed low p27 expression (<50% nuclei positive) compared to 6 of 20 (30%) stage-matched sporadic colorectal carcinomas (P < 0.001). We conclude (i) aberrant p27 protein expression in inflamed and IBD-associated nondysplastic mucosa is indistinguishable from that found in transitional mucosa adjacent to sporadic carcinomas; (ii) p27 is overexpressed in dysplastic lesions, perhaps as an attempt to counterbalance proliferative stimuli; and (iii) IBD-associated colorectal carcinomas have significantly lower p27 expression, commonly associated with poor prognosis, than stage-matched sporadic colorectal carcinomas. These findings further substantiate the existence of divergent molecular pathogenetic pathways between these types of carcinomas and suggest an intrinsically more aggressive behavior of IBD-associated colon carcinomas compared to sporadic ones.
In-person interviews with two hundred and twenty-one older African Americans and whites in Allegheny County, Pennsylvania on their use of self care activities in the care of one of four chronic illnesses (chronic obstructive pulmonary disease (COPD), heart disease, diabetes mellitus, and arthritis, addressed which types of self care they used for each of these illnesses) the similarities and differences between African Americans and whites in their use of self care and how self care is initiated, modified and integrated into a context that includes help from others. The most common response in each of the illnesses was the use of medications or medical treatments by both African Americans and whites. However, there were some differences in the self care practices used by these two groups by illness type. Whites reported monitoring their illness significantly more than African Americans for diabetes and using assistive devices in the management of COPD significantly more than African Americans. While both African Americans and whites practice self care similarly in the management of heart disease, African Americans reported greater use of exercise in their management of arthritis. The amount of assistance provided by others in support of self care varied by illness and by African American and white. The differences in self care usage may be attributed to many factors, among them, differences in cultural experiences with the illness, health beliefs regarding its efficacy and the amount of assistance received from informal supports.
We have previously shown that human munc13 (hmunc13) is up-regulated by hyperglycemia under in vitro conditions in human mesangial cell cultures. The purpose of the present study was to determine the cellular function of hmunc13. To do this, we have investigated the subcellular localization of hmunc13 in a transiently transfected renal cell line, opossum kidney cells. We have found that hmunc13 is a cytoplasmic protein and is translocated to the Golgi apparatus after phorbol ester stimulation. In addition, cells transfected with hmunc13 demonstrate apoptosis after treatment with phorbol ester, but cells transfected with an hmunc13 deletion mutant in which the diacylglycerol (C1) binding domain is absent exhibit no change in intracellular distribution and no induction of apoptosis in the presence of phorbol ester stimulation. We conclude that both the diacylglycerol-induced translocation and the apoptosis represent functional activity of hmunc13. We have also demonstrated that munc13-1 and munc13-2 are localized mainly to cortical epithelial cells in rat kidney and both are overexpressed under conditions of hyperglycemia in a streptozotocin-treated diabetic rat model. Taken together, our data suggest that hmunc13 serves as a diacylglycerol-activated, PKC-independent signaling pathway capable of inducing apoptosis and that this pathway may contribute to the renal cell complications of hyperglycemia.
Outcome measures are used to monitor the effects of interventions in clinical practice or in formal clinical trials. They may also be used to assess changes within populations either spontaneously or as a result of public-health measures. They are used to monitor the course of illness as part of a management plan or, for larger groups, to identify changes brought about, for instance, by migration or immunization. The choice of outcome measure depends on the age of the child, the complexity of the outcome (for instance, whether its application is to individuals or populations), and the time scale over which it is necessary to detect changes in outcome. The most commonly used outcome measures are clinical symptoms, which are often compiled into scoring systems. Surprisingly, these are often the least well-validated measures of outcome. Physiologic measures, although well validated, are difficult to apply to infants and pre-school children. The role of inflammatory markers is currently limited to research rather than clinical practice. Other outcome measures such as quality of life, impact-of-asthma instruments, and measures to determine the health-economic aspects of asthma are poorly developed in childhood. The right outcome depends on the question being asked, the age of the subjects, and the time scale and complexity over which measurement is required.
BACKGROUND: Discharge planning is becoming an important part of the management of childhood asthma in hospital. Readmission to hospital, although often inevitable, might represent a failure of the opportunity for intervention presented by a brief period of supervised care in hospital. AIM: To examine the impact of a structured, nurse-led discharge package for children admitted to hospital with acute asthma on readmission to hospital, reattendance at the accident and emergency (A&E) department, and general practitioner consultations for asthma. METHODS: A structured nurse-led discharge package, consisting of a 20 minute patient education programme and self management plan for children with asthma was developed on the wards of a busy children's hospital. A randomised controlled trial was conducted involving 160 children aged 2-16 years admitted for asthma over a 12 month period. Readmission and A&E reattendance's over the six months after discharge from hospital were obtained from the hospital computerised information system and general practitioner consultations from practice records. RESULTS: Children in the intervention group were significantly less likely to be readmitted to hospital in the next six months than those in the control group (12 of 80 v 30 of 80 patients), and significantly less likely to attend the A&E department (6 of 80 v 31 of 80). Significantly fewer children in the intervention group had visits to their general practitioner for problematic asthma (31 of 78 v 72 of 77 for whom data were available). CONCLUSION: By delivering the simplest form of education and support during a child's stay in hospital, readmissions over a six month period were reduced. The programme was designed to be suitable for administration by nursing staff on the children's wards after a brief period of training.
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We have used the recombinant NH2-terminal myc-tagged rabbit Na+-glucose transporter (SGLT1) to study the regulation of this carrier expressed in COS-7 cells. Treatment of cells with a protein kinase C (PKC) agonist, phorbol 12-myristate 13-acetate (PMA), caused a significant decrease (38.03 +/- 0.05%) in methyl alpha-D-glucopyranoside transport activity that could not be emulated by 4alpha-phorbol 12,13-didecanoate. The decrease in sugar uptake stimulated by PMA was reversed by the PKC inhibitor bisindolylmaleimide I. The maximal rate of Na+-glucose cotransport activity (Vmax) was decreased from 1.29 +/- 0.09 to 0.85 +/- 0.04 nmol. min-1. mg protein-1 after PMA exposure. However, measurement of high-affinity Na+-dependent phloridzin binding revealed that there was no difference in the number of cell surface transporters after PMA treatment; maximal binding capacities were 1.54 +/- 0.34 and 1.64 +/- 0.21 pmol/mg protein for untreated and treated cells, respectively. The apparent sugar binding affinity (Michaelis-Menten constant) and phloridzin binding affinity (dissociation constant) were not affected by PMA. Because PKC reduced Vmax without affecting the number of cell surface SGLT1 transporters, we conclude that PKC has a direct effect on the carrier, resulting in a lowering of the transporter turnover rate by a factor of two.
Reactive oxygen species (ROS) initiate multiple pathological and physiological cellular responses, including tyrosine phosphorylation of proteins. In this study, we investigated the effects of ROS on cell-extracellular matrix interactions utilizing the floating three-dimensional collagen gel assay. Exposure of mesangial cells grown in three-dimensional culture to H2O2, 3-amino-1,2,4-triazole (a catalase inhibitor), or puromycin is associated with gel reorganization accompanied by tyrosine phosphorylation of multiple proteins, including focal adhesion kinase (FAK). Neutrophils cocultured with mesangial cells in three-dimensional culture also induce mesangial cell-collagen gel reorganization and initiate tyrosine phosphorylation of a similar set of proteins. Collectively, these results show that ROS of either endogenous or exogenous origin can modulate mesangial cell-extracellular matrix interactions through initiation of a phosphotyrosine kinase signaling cascade. Consequently, ROS may play a role as signaling molecules that regulate mesangial cell-extracellular matrix interactions in both physiological and pathological conditions.
Site-directed mutagenesis and chemical modification of specific cysteine amino acid side chains by methanethiosulfonate (MTS) derivatives were combined to elucidate structure/function relationships of the cloned rabbit Na+/glucose cotransporter, SGLT1. Each amino acid in the region (residues 162-173) between putative transmembrane helices IV and V of SGLT1 was replaced individually with Cys. Mutant proteins were expressed in Xenopus laevis oocytes and studied using the two-electrode voltage clamp method. At certain key positions, Cys substitution resulted in 1) a change in the apparent affinity for sugar, 2) an alteration in the voltage dependence of the transient currents, and 3) a sensitivity to inhibition by either the ethylamine (MTSEA) or the ethylsulfonate MTS derivatives. For the three Cys mutants inhibited by MTSEA (F163C, A166C, and L173C), inhibition of steady state transport is related to changes in membrane potential-dependent transitions within the Na+/glucose transport cycle. MTSEA shifted the transient currents of these Cys mutants toward more negative membrane potentials (DeltaV0. 5 = -18 mV for F163C and A166C, -12 mV for L173C). When the mutations were combined to produce double and triple Cys mutants, the degree to which the transient currents were shifted along the membrane potential axis by MTSEA correlated with the number of cysteines. In this way it was possible to manipulate the voltage dependence of the transient currents over a range spanning 91 mV. Examination of the Na+ dependence of the transient currents indicates that a 91-mV shift is equivalent to that caused by a 10-fold reduction in the external Na+ concentration. We conclude that this region has a role in determining the Na+ binding- and voltage-sensing properties of SGLT1 and that it forms an alpha-helix with one surface possibly lining a Na+ pore within SGLT1.
The pineal hormone, melatonin, inhibits proliferation of estrogen receptor (ER)-positive MCF-7 human breast cancer cells, modulates both ER mRNA and protein expression, and appears to be serum dependent, indicating interaction between melatonin and serum components. To examine the effects of melatonin on ER activity, ER transactivation assays were performed by transiently transfecting MCF-7 cells with an ERE-luciferase reporter construct. MCF-7 cells pre-treated with melatonin for as little as 5 min followed by either epidermal growth factor (EGF) or insulin resulted in the estrogen-independent transactivation of the ER. None of the compounds when used alone transactivated the ER. The ability of melatonin and EGF to transactivate the ER was abolished by the addition of the antiestrogen, ICI 164384, suggesting that melatonin and EGF co-operate to transactivate the ER. The modulation of ER transactivation was associated with changes in mitogen activated protein kinase activity and ER phosphorylation. This ER transactivation was blocked by pertussis toxin, a Galpha i-protein-coupled receptor inhibitor, suggesting cross talk between the G-protein-coupled melatonin receptor pathway and the EGF/insulin tyrosine kinase receptor pathways in modulating ER transactivation. Exactly how the ability of melatonin in combination with EGF to transactivate the ER relates to melatonin's observed growth suppressive effects is not clear. It is possible that, although melatonin and EGF transactivate the ER, this transactivation does not result in the full transcription of estrogen-responsive genes, but rather, makes the ER refractory to activation by estradiol, thus, blocking the mitogenic actions of estradiol.
Ontario's Medical Expert Panel on Duty to Inform was formed to consider the duty of Ontario physicians in circumstances where a patient threatens to kill or cause serious bodily harm to a third party. The panel was concerned about the implications of any duty to inform on the integrity of the physician-patient relationship, particularly with respect to confidentiality. The panel agreed that regulations safeguarding the confidentiality of patient information ought to be changed only if there is a critical reason for doing so, but, after deliberation, the panel members concluded that the need to protect the public from serious risk of harm is a paramount concern that should supersede the duty of confidentiality. The recommendations reported here were endorsed in principle by the panelists and the groups they represented (the Royal College of Physicians and Surgeons of Canada, the Canadian Medical Protective Association, the College of Physicians and Surgeons of Ontario, the Ontario College of Family Physicians and the Ontario Medical Association) and are being implemented by the College of Physicians and Surgeons of Ontario.