Primary hepatic angiocentric lymphoma.
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Aged↗
Biomedical subjects
K Fox
Publications and source records attributed to K Fox.
An in vitro study of coronal microleakage in root-canal-treated teeth restored by the post and core technique.
The aims of this study were to compare coronal microleakage around cast and prefabricated post and cores and to examine the coronal seal achieved by temporary post crowns. Thirty extracted, single-rooted, human teeth were prepared chemomechanically, root filled with gutta-percha and sealer and prepared for a standard post. Three groups, each of 10 teeth, were restored with either: (i) cast post and cores cemented with zinc phosphate cement; (ii) prefabricated posts and composite cores cemented with a composite luting cement; or (iii) temporary post crowns cemented with a temporary zinc oxide-eugenol cement. The teeth were thermocycled and placed in Indian ink for 1 week, then demineralized and rendered transparent. Linear coronal dye penetration around the posts was measured and recorded. Results indicated that while cast post and cores and prefabricated posts and composite cores produced a good seal, leakage was significantly greater with temporary post crowns (P < 0.05). It is concluded that to prevent re-infection of the root canal system, it may be preferable to restore the tooth immediately with a prefabricated post and composite system rather than place a temporary post crown and subsequently a cast post and core.
Analysis of Variance↗
Putting the heart back into audit.
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Cardiology↗
Concrete induced cardiac contusion.
A previously fit 22 year old man was struck in the chest by a concrete block dropped through the windscreen of his car while he was driving on the motorway. He suffered extensive chest wall trauma and lung contusion, which subsequently precipitated acute respiratory distress. On admission ECG showed right bundle branch block and left axis deviation. Three days later QRS duration was normal but there was anterior ST segment elevation and subsequent T wave change. There was a large rise in creatine kinase, and echocardiography revealed septal and apical hyokinesis as well as a mobile mass attached to the left side of the interventricular septum, which had the echogenic texture of myocardium. The patient had fixed perfusion defects in the areas of hypokinesis on thallium scanning but the coronary arteries were unobstructed at angiography. He was treated with warfarin in the short term and an angiotensin converting enzyme inhibitor in the longer term and has made an asymptomatic recovery. Outpatient echocardiography two months after the injury demonstrated some recovery in overall left ventricular systolic function and no evidence of the intracardiac mass. This case illustrates some of the typical features of non-fatal cardiac contusion associated with non-penetrating cardiac trauma, and was complicated by partial thickness avulsion of a strip of the myocardium in the interventricular septum.
Accidents, Traffic↗
A treatable cause of lymphocytic meningo-encephalitis.
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Adult↗
Modulation of MHC isoforms in functionally overloaded and exercised rat plantaris fibers.
The effects of 1 and 10 wk of functional overload (FO) of the rat plantaris with (FOTr) and without daily endurance treadmill training on its myosin heavy chain (MHC) composition were studied. After 1 and 10 wk of FO, plantaris mass was 22 and 56% greater in FO and 37 and 94% greater, respectively, in FOTr rats compared with age-matched controls. At 1 wk, pure type I and pure type IIa MHC fibers were hypertrophied in FO (39 and 44%) and FOTr (70 and 87%) rats. By 10 wk all fiber types comprising >5% of the fibers sampled showed a hypertrophic response in both FO groups. One week of FO increased the percentage of hybrid (containing both type I and type IIa MHC) fibers and of fibers containing embryonic MHC. By 10 wk, the percentage of pure type I MHC fibers was approximately 40% in both FO groups compared with 15% in controls, and the percentage of fibers containing embryonic MHC was similar to that in controls. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis analyses showed an increase in type I MHC and a decrease in type IIb MHC in both FO groups at 10 wk, whereas little change was observed at 1 wk. These data are consistent with hypertrophy and transformation from faster to slower MHC isoforms in chronically overloaded muscles. The additional overload imposed by daily endurance treadmill training employed in this study (1.6 km/day; 10% incline) results in a larger hypertrophic response but appears to have a minimal effect on the MHC adaptations.
Animals↗
Altered platelet function detected by flow cytometry. Effects of coronary artery disease and age.
Platelet activation state and responsiveness to physiological agonists were measured in 65 patients with documented coronary artery disease (54 male and 11 female; mean age, 58 years). Twelve patients (mean age, 52 years), selected at random from the male cohort, were compared with 12 age-matched male control subjects (mean age, 52 years) and with 10 normal, young male subjects (mean age, 25 years). Whole-blood flow cytometry was used to measure platelet activation status ex vivo and platelet responsiveness to physiological agonists in vitro. Peripheral blood samples were analyzed for bound fibrinogen and expression of P-selectin, GPIb, and GPIIb-IIIa at rest and in response to ADP (0.1 to 10 mumol/L) and thrombin (0.02 to 0.32 mu/mL). No significant differences were seen in the basal levels of fibrinogen binding between any of the groups, but P-selectin expression was significantly lower in patients compared with age-matched control subjects (P = .0005). When stimulated with agonists, patients' platelets had significantly decreased fibrinogen binding (P < .03) but no difference in P-selectin expression compared with the age-matched group. Both agonist-induced fibrinogen binding and P-selectin expression were, however, higher in the young subjects compared with either the older control group or the patients (P < .05). GPIb and GPIIb-IIIa expression were lowest in the patients with angina and highest in the young control subjects, with levels in the age-matched control subjects falling between these values. Data from the total patient cohort (n = 65) were identical to those in the smaller cohort (n = 12). In conclusion, atherosclerosis impairs platelet aggregatory responses (fibrinogen binding) over and above the decreased response seen with age. Platelet degranulation (P-selectin expression) is also impaired in patients with coronary artery disease, but only in comparison with younger subjects, not age-matched controls.
Adult↗
Beta 2-microglobulin removal by synthetic dialysis membranes. Mechanisms and kinetics of the molecule.
Beta 2-microglobulin (beta 2-m) accumulation represents a possible complication of long term dialysis. It is therefore important to evaluate the capacity of removal of this molecule from the patient by different dialysis membranes. The present study is aimed at evaluating the mechanisms involved in beta 2-m removal by three different synthetic membranes: a) highly asymmetric hydrophobic polysulfone (Biosulfane, NMC), b) moderately asymmetric and hydrophobic polysulfone (PS600, Fresenius), c) Polyacylonitrile (AN69HF, Hospal). The adsorption capacity and sieving coefficients of the three membranes for native and labeled beta 2-m were studied in vitro utilizing human blood. The amount adsorbed by the membrane was measured by the elution of the molecule obtained with a detergent solution. Clearances, total removal and membrane adsorption were studied in six patients treated in a randomized sequence with the three membranes. For this purpose, plasma and dialysate measurements as well as total collection of spent dialysate and beta 2-m elution from the used dialyzers were carried out. Ex novo generation of beta 2-m did not take place during in vitro circulation. The molecule was removed by the studied membranes both by filtration and adsorption. The Biosulfane membrane removed beta 2-m mostly by adsorption while the PS600 membrane removed beta 2-m almost entirely by filtration. Intermediate behaviour was shown by AN69 membrane. Similar quantities of beta 2-m were removed from the patients with the three membranes. Total removal could only be precisely measured by adding the quantity of beta 2-m eluted from the membrane to the amount recovered in the spent dialysate. Out of total removal, adsorption was more than 90% with Biosulfane, while only 5% with the PS600. These findings contribute to the understanding of the discrepancy found between the clearance measured from the plasma side and that measured from the dialysate side. In conclusion, clearance and sieving measurements for beta 2-m cannot be correctly performed unless the capacity of adsorption of the membrane is taken into account.
Acrylic Resins↗
Physical activity promotion through primary health care in England.
BACKGROUND: There is increasing research supporting the argument for a beneficial link between physical activity and health maintenance and, in the past five years, this has led to a growth in physical activity promotion schemes involving primary health care. AIM: To document and critically examine the extent and nature of physical activity promotion in general practice in England. METHOD: A postal survey to all family health services authorities and primary care facilitators was conducted to identify existing and planned activity promotion schemes involving primary health care. Telephone interviews with leaders from 50 selected schemes and further detailed case studies of 11 schemes provided descriptive information of the nature of physical activity promotion. RESULTS: The initial phase revealed 157 existing schemes and a further 35 planned schemes. Two basic models of physical activity promotion were identified that were distinguishable by the primary location of the management of the patient. Practice-managed interventions (32%) involve on-site counselling to change the behaviour of patients. Leisure centre-managed projects (68%), sometimes termed 'exercise by prescription' or 'general practitioner referral for exercise' schemes, involve the identification of suitable patients and their referral to 10- to 12-week-long leisure centre based exercise induction courses. The projects in the planning stage were all of the latter type, indicating this as the favoured model. Although such schemes were generally successful in attracting patients, in all cases they involved less than 1% of the patient base from which they were drawn. CONCLUSION: There is evidence of successful recruitment, increased short-term physical activity and fitness, and improvements in the well-being of patients. However, schemes are inadequately resourced for rigorous long-term evaluation; therefore, conclusions regarding the cost-effectiveness of the two models are not possible.
England↗
Diagnosis and treatment of the cracked tooth.
This review paper discusses the recognised factors which predispose to cracked-tooth syndrome. In addition, common presenting symptoms and the various methods to aid clinical diagnosis of this problem are examined. The incidence of the condition is reported and the prognosis of the various forms of fracture, as suggested by clinical presentation, are outlined with reference to the available literature. Benefits and relative demerits of traditional and more modern treatment options are presented and recommendations made for future research.
Cracked Tooth Syndrome↗
Tenuous link between ischaemic threshold and both ambulatory ischaemia and symptom status over time in stable angina: a 5-year follow-up study.
This study evaluates changes in ischaemic threshold over a 5-year period in patients with stable angina pectoris, who did not suffer any intervening cardiac event. Changes in ischaemic threshold are related to alterations in symptomatic status and ambulatory ischaemia. Over long-term follow-up, there is a significant fall in ischaemic threshold in such patients (mean heart rate at onset of ischaemia fell from 104 +/- 17.8 to 97 +/- 17.4 bpm: P < 0.001), but this is not matched by a worsening of either symptoms or ischaemia during daily life. In the 68% of patients that had a reduction in ischaemic threshold of > or = 5 bpm, 68% had either definite reduction or no change in symptoms and 84% had either reduction, abolition or no change in transient ischaemic activity. The dissociation between ischaemic threshold, ambulatory ischaemia and symptoms has implications for long-term monitoring and management of the patient with stable angina.
Adult↗
Glutamate receptor blockade at cortical synapses disrupts development of thalamocortical and columnar organization in somatosensory cortex.
The segregation of thalamocortical inputs into eye-specific stripes in the developing cat or monkey visual cortex is prevented by manipulations that perturb or abolish neural activity in the visual pathway. Such findings show that proper development of the functional organization of visual cortex is dependent on normal patterns of neural activity. The generalisation of this conclusion to other sensory cortices has been questioned by findings that the segregation of thalamocortical afferents into a somatotopic barrel pattern in developing rodent primary somatosensory cortex (S1) is not prevented by activity blockade. We show that a temporary block of N-methyl-D-aspartate (NMDA) and non-NMDA glutamate receptors in rat S1 during the critical period for barrel development disrupts the topographic refinement of thalamocortical connectivity and columnar organization. These effects are evident well after the blockade is ineffective and thus may be permanent. Our findings show that neural activity and specifically the activation of postsynaptic cortical neurons has a prominent role in establishing the primary sensory map in S1, as well as the topographic organization of higher order synaptic connections.
2-Amino-5-phosphonovalerate↗
Requirement for alpha-CaMKII in experience-dependent plasticity of the barrel cortex.
The mammalian sensory neocortex exhibits experience-dependent plasticity such that neurons modify their response properties according to changes in sensory experience. The synaptic plasticity mechanism of long-term potentiation requiring calcium-calmodulin-dependent kinase type II (CaMKII) could underlie experience-dependent plasticity. Plasticity in adult mice can be induced by changes in the patterns of tactile input to the barrel cortex. This response is strongly depressed in adult mice that lack the gene encoding alpha-CaMKII, although adolescent animals are unaffected. Thus, alpha-CaMKII is necessary either for the induction or for the expression of plasticity in adult mice.
Animals↗
Hypertension and heart disease.
Peripheral blood pressure and heart disease are closely linked. Hypertension is not only associated with, but also a cause of, heart disease and evidence is mounting that treating hypertension reduces cardiac events. The knowledge and management of blood pressure is a key element of cardiac care.
Heart Diseases↗
The role of excitatory amino acid transmission in development and plasticity of SI barrel cortex.
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Animals↗
Mechanisms underlying experience-dependent potentiation and depression of vibrissae responses in barrel cortex.
Plasticity was studied in the barrel cortex of rats and mice. Vibrissae deprivation in adult and adolescent animals caused changes in the response properties of cortical neurons to stimulation of spared and deprived vibrissae. Plasticity involved both potentiation of spared vibrissae responses and depression of deprived vibrissae responses in layer II/III of the cortex. Vibrissae response potentiation was found to require alpha CaMKII in adult cortex. Vibrissae response depression was not found to occur in adult cortex but was found in adolescent animals for the principal vibrissa. Preliminary results suggested that vibrissae response depression exhibits both hetero- and homosynaptic components.
Animals↗
Effects of intermittent androgen suppression on the stem cell composition and the expression of the TRPM-2 (clusterin) gene in the Shionogi carcinoma.
The proportion of tumorigenic stem cells and the expression of the apoptosis-related gene, TRPM-2 (clusterin), were studied in populations of Shionogi carcinoma cells subjected to multiple cycles of androgen withdrawal and replacement (intermittent androgen suppression). The parent androgen-dependent cell line was initially transplanted into a male mouse which was castrated when the estimated weight of the resultant tumour became approximately 3 g. After the tumour had regressed to 40% or less of the original weight, it was transplanted into the next non-castrated male. This was repeated for four cycles of transplantation and castration-induced apoptosis before the tumour progressed to an androgen-independent state. The proportion of total stem cells in the tumour, as determined by in vivo limiting dilution assays in male mice, was constant during the first three cycles but increased 15-fold between the third and fourth cycles. In the parent androgen-dependent tumour before androgen ablation, the androgen-independent stem cell population formed 0.8% of the total stem cell compartment. After the fourth cycle this population increased to 47%; a population of similar size (33%, P = 0.8) was found in the androgen-independent recurrent form of the tumour induced by one-time castration. Whether androgen withdrawal therapy was intermittent or continuous, conversion to androgen independence thus occurred when one-third to one-half of the total stem cell compartment was populated by androgen-independent stem cells. The androgen-repressed TRPM-2 (clusterin) gene was actively expressed in regressing tumours after androgen ablation, and also became constitutively expressed in non-regressing tumours after the first and subsequent cycles of androgen withdrawal. Staining of cytoplasm and nuclei with anti-clusterin antibody was observed in androgen-dependent tumour cells after each cycle of intermittent androgen suppression; the nuclear staining was more intense in recurrent androgen-independent cells. The anomalous nuclear localization of clusterin, an anti-cytolytic TRPM-2 encoded protein, may serve to inhibit early events in the apoptotic process and thereby foster the generation and outgrowth of androgen-independent stem cells in an androgen-depleted environment.
Androgens↗
Registration of births, stillbirths and infant deaths in Jamaica.
BACKGROUND: Vital statistics underestimate the prevalence of perinatal and infant deaths. This is particularly significant when these parameters affect eligibility for international assistance for newly emerging nations. OBJECTIVE: To determine the level of registration of livebirths, stillbirths and infant deaths in Jamaica. METHODOLOGY: Births, stillbirths and neonatal deaths identified during a cross-sectional study (1986); and infant deaths identified in six parishes (1993) were matched to vital registration documents filed with the Registrar General. RESULTS: While 94% of livebirths were registered by one year of age (1986), only 13% of stillbirths (1986) and 25% of infant deaths (1993) were registered. Post neonatal deaths were more likely to be registered than early neonatal deaths. Frequently the birth was not registered when the infant died. Birth registration rates were highest in parishes with high rates of hospital deliveries (rs = 0.97, P < 0.001) where institutions notify the registrar of each birth. Hospital deaths, however, were less likely to be registered than community deaths as registrars are not automatically notified of these deaths. CONCLUSIONS: To improve vital registration, institutions should become registration centres for all vital events occurring there (births, stillbirths, deaths). Recommendations aimed at modernizing the vital registration system in Jamaica and other developing countries are also made.
Birth Certificates↗