Single Centre Experience - Clinical Presentation and Frequency of Paediatric Diabetic Ketoacidosis (DKA) At Diagnosis over a 5-Year Period.

Type 1 diabetes (T1D) symptoms are subtle and easily overlooked. Delayed diagnosis can result in Diabetic ketoacidosis (DKA), a life threatening complication with lasting consequences. We sought to define the presenting features of T1D and DKA frequency, in children <15 years diagnosed in a single national tertiary centre, and identify predictive factors for DKA. A review of T1D incident cases was undertaken from 2008-2012 using the National Diabetes Register (ICDNR) and clinical case notes. Data were compared with a 1997/8 national study. We found DKA at presentation in 28.7 % of children and 15.5% had moderate/severe DKA. Commonest symptoms were polydipsia, polyuria, weight loss, and lethargy. Median symptom duration was 17 days. Clinical presentation was similar and frequency of DKA at T1D diagnosis remains high. The proportion with moderate/severe DKA is lower than the 25% previously reported (p=0.038). National monitoring and targeted action to reduce DKA at diagnosis is required.

The incidence of childhood type 1 diabetes in Ireland and the National Childhood Diabetes Register.

The incidence of Type 1 diabetes (T1D) in childhood and adolescence is increasing globally with few exceptions. To date limited conflicting data has been available regarding diabetes epidemiology in Ireland. We sought to determine the incidence of T1D in those aged under 15 years in the ROI by establishing a prospective national register of incident cases (Irish Childhood Diabetes National Registry (ICDNR)) using a standardised protocol which includes a measure of case ascertainment using capture-recapture methodology. In the period, 489 new cases were identified. All paediatric centres nationally participated. The directly standardised incidence rate was 27.5 per 100,000 per year (95% CIs: 24.0, 30.9) and 26.0 (95% CIs: 22.7, 29.3) in 2008 and 2009 respectively. The ICDNR is widely acceptable, it has confirmed a high incidence of T1D and is vital to monitor changes in disease incidence, optimise resource utilisation and diabetes management in the Irish population.

BRCA1 dysfunction in sporadic basal-like breast cancer.

Basal-like breast cancers form a distinct subtype of breast cancer characterized by the expression of markers expressed in normal basal/myoepithelial cells. Breast cancers arising in carriers of germline BRCA1 mutations are predominately of basal-like type, suggesting that BRCA1 dysfunction may play a role in the pathogenesis of sporadic basal-like cancers. We analysed 37 sporadic breast cancers expressing the basal marker cytokeratin 5/6, and age- and grade-matched controls, for downregulation of BRCA1. Although BRCA1 promoter methylation was no more common in basal-like cancers (basal 14% vs controls 11%, P=0.72), BRCA1 messenger RNA expression was twofold lower in basal-like breast cancers compared to matched controls (P=0.008). ID4, a negative regulator of BRCA1, was expressed at 9.1-fold higher levels in basal-like breast cancer (P<0.0001), suggesting a potential mechanism of BRCA1 downregulation. BRCA1 downregulation correlated with the presence of multiple basal markers, revealing heterogeneity in the basal-like phenotype. Finally, we found that 63% of metaplastic breast cancers, a rare type of basal-like cancers, had BRCA1 methylation, in comparison to 12% of controls (P<0.0001). The high prevalence of BRCA1 dysfunction identified in this study could be exploited in the development of novel approaches to targeted treatment of basal-like breast cancer.

A growth factor-responsive gene of murine BALB/c 3T3 cells encodes a protein homologous to human tissue factor.

Polypeptide growth factors rapidly induce the transcription of a set of genes that appear to mediate cell growth. We report that one of the genes induced in BALB/c mouse 3T3 cells encodes a transmembrane protein (mTF) homologous to human tissue factor, which is involved in the proteolytic activation of blood clotting. mTF mRNA is present in many murine tissues and cell lines. Our results raise the possibility that mTF may also play a role in cell growth.

Quantitative analysis of the contribution made by 5'-flanking and 3'-flanking sequences to the transcriptional regulation of junB by growth factors.

We have identified four DNAase I-hypersensitive regions (DHRs) at the junB locus. DHR1 is located between sequences -100 and +250, DHR2 is centered at -1000, DHR3 at -1650, and DHR4 at +2040 relative to the junB transcriptional start site. Sequence analysis of these DHRs revealed two serum response elements at -1452 and +2091, two cyclic AMP response elements at +2071 and +2116, and a 12-O-tetradecanoylphorbol-13-acetate (TPA) response element at -949. To study the contribution made by these cis-elements to junB transcriptional regulation, we stably transfected a recombinant mouse junB gene (JBSV4) containing the intact junB coding sequences, 6.3 kb of 5'-flanking DNA, and 2.0 kb of 3'-flanking DNA into Rat1A cells. The pattern of DHRs identified at the mouse junB locus was re-established at the JBSV4 locus. By directly comparing JBSV4 and rat junB mRNA levels, we found that these genes were induced to equivalent levels by serum, TPA, cyclic AMP, platelet-derived growth factor, epidermal growth factor, and basic fibroblastic growth factor. These results established that JBSV4 resides in a physical environment within chromatin that closely mimics that of the junB locus, and contains the necessary sequence information to recapitulate the transcriptional regulation of junB. By analysing a series of recombinant mouse junB genes containing deletion mutations in 5'-flanking and 3'-flanking sequences, we provide a quantitative assessment of the contribution these sequences make to junB induction by different regulatory agents.

Chromosomal integration dependent induction of junB by growth factors requires multiple flanking evolutionarily conserved sequences.

The junB locus contains nine flanking evolutionarily conserved sequences (FECS) that share 72% to 91% sequence identity between human and mouse. These FECS encompass the same regions of flanking DNA necessary for maximal mitogenic induction of junB. Most of the cis elements reported to date that affect junB regulation also reside within FECS. These observations suggest that the persistence of FECS through evolution reflects a necessary role in junB transcriptional regulation. In this report, we identify specific regulatory cis elements within junB FECS II and III and provide a quantitative analysis of the contribution made by these sequences to junB induction. These cis elements include a Serum Response Element (SRE), two Ets sites previously unrecognized as contributing to junB expression, and two novel Ets-linked motifs (ELMs). In general, mutating any single element significantly impairs junB induction. Moreover, the same mutations alter the structure of junB 5' flanking DNA within chromatin. Collectively, these results suggest that multiple proteins bound within FECS confederate to form a functional promoter complex, the activity of which is dependent upon a specific chromatin architecture.

Left ventricular hypertrophy in hypertensive patients is associated with abnormal rate adaptation of QT interval.

OBJECTIVES: This study sought to examine whether the responses of the QT interval to changes in the heart rate were altered in left ventricular hypertrophy (LVH). BACKGROUND: The QT interval has been shown to have a delayed adaptation to sudden changes in heart rate in normal subjects. Abnormalities in the adaptation of the QT interval to changes in the RR interval may facilitate the development of ventricular arrhythmias. METHODS: Consecutive newly diagnosed hypertensive subjects, not taking any medications, were age and gender matched for LVH (n = 21) versus on LVH (n = 16). QT interval dynamics were analyzed under visual control using a validated algorithm with automatic QT measurements at the end of the T wave. A computerized Holter system was developed to study the QT interval response to changes in the RR interval. The adaptive response of the QT interval was measured as the ratio of the slope from 10% to 90% of the QT change relative to the RR interval change (dQT/dRR10-90). Steady state adaptation was also studied as the percent shortening and lengthening of the QT interval during acceleration and deceleration of heart rate. RESULTS: The adaptive response of the QT interval measured as dQT/dRR10-90 was increased in the LVH group compared with that in the control subjects during both acceleration (0.33 +/- 0.06 vs. 0.18 +/- 0.02, p = 0.02) and deceleration phases (0.23 +/- 0.04 vs. 0.16 +/- 0.02, p = 0.03). In the LVH group, the percent lengthening of the QT interval was greater (7.6 +/- 0.7 vs. 5.1 +/- 0.2, p = 0.03), whereas the percent shortening was not significantly different (5.71 +/- 0.5 vs. 4.6 +/- 0.3, p = 0.43), than that in control subjects. CONCLUSIONS: The QT interval response to changes in the RR interval is rapid and exaggerated in LVH. These abnormalities of the QT interval response demonstrate that there are altered repolarization dynamics in patients with LVH that may make them vulnerable to serious ventricular arrhythmias.

Membrane current changes in left ventricular myocytes isolated from guinea pigs after abdominal aortic coarctation.

OBJECTIVE: The aim was to look for membrane current changes as a basis for the prolongation of action potential duration in left ventricular myocytes following abdominal aortic coarctation. METHODS: Immature female guinea pigs underwent laparotomy and an aortic coarctation was fashioned immediately distal to the renal arteries. After 20 weeks the hearts were removed and single myocytes were isolated from the left ventricles by standard enzymatic techniques. The switch-clamp technique was used. RESULTS: Heart weight:body weight ratio was increased by 7% in the coarctation group (p < 0.01). Systolic left ventricular pressure was 59(SEM 4) mm Hg in control and 76(7) mm Hg in coarctation animals (p < 0.05). Cell capacity was increased by 21% in the coarctation group (p < 0.05), and mean resting potential was 4.6 mV more negative in this group (p < 0.001). Action potential duration at 90% repolarisation was 310(17) ms in the control group (n = 22) and 358(13) ms in the coarctation group (n = 34, p < 0.05). Peak density of L-type calcium current was -8.6(0.4) pA.pF-1 in control and -11.1(0.7) pA.pF-1 in coarctation cells (p < 0.01). The regression line for calcium current versus cell capacity was shifted to higher calcium currents in the coarctation group. The half inactivation potential for this current was shifted by 11.5 mV (p < 0.01). Calcium-activated tail currents were larger and the envelope of tail currents was prolonged in the coarctation cells. No significant differences were found in the amplitude of IK or of IKl. CONCLUSIONS: After infrarenal aortic coarctation, action potential duration of left ventricular myocytes is prolonged. This prolongation may be attributed to an increase in calcium current density and a shift of its inactivation variable, together with an increased magnitude and prolonged time course of sodium-calcium exchange current. These current changes are potentially arrhythmogenic.

Parathyroid hormone enhances fluid shear-induced [Ca2+]i signaling in osteoblastic cells through activation of mechanosensitive and voltage-sensitive Ca2+ channels.

Osteoblasts respond to both fluid shear and parathyroid hormone (PTH) with a rapid increase in intracellular calcium concentration ([Ca2+]i). Because both stimuli modulate the kinetics of the mechanosensitive cation channel (MSCC), we postulated PTH would enhance the [Ca2+]i response to fluid shear by increasing the sensitivity of MSCCs. After a 3-minute preflow at 1 dyne/cm2, MC3T3-E1 cells were subjected to various levels of shear and changes in [Ca2+]i were assessed using Fura-2. Pretreatment with 50 nM bovine PTH(1-34) [bPTH(1-34)] significantly enhanced the shear magnitude-dependent increase in [Ca2+]i. Gadolinium (Gd3+), an MSCC blocker, significantly inhibited the mean peak [Ca2+]i response to shear and shear + bPTH(1-34). Nifedipine (Nif), an L-type voltage-sensitive Ca2+ channel (VSCC) blocker, also significantly reduced the [Ca2+]i response to shear + bPTH(1-34), but not to shear alone, suggesting VSCC activation plays an interactive role in the action of these stimuli together. Activation of either the protein kinase C (PKC) or protein kinase A (PKA) pathways with specific agonists indicated that PKC activation did not alter the Ca2+ response to shear, whereas PKA activation significantly increased the [Ca2+]i response to lower magnitudes of shear. bPTH(1-34), which activates both pathways, induced the greatest [Ca2+]i response at each level of shear, suggesting an interaction of these pathways in this response. These data indicate that PTH significantly enhances the [Ca2+]i response to shear primarily via PKA modulation of the MSCC and VSCC.

The interaction of oestrogen receptor status and pathological features with adjuvant treatment in relation to survival in patients with operable breast cancer: a retrospective study of 2660 patients.

The oestrogen receptor (ER) status of 2660 patients with primary breast cancer has been related to the effect of different adjuvant systemic therapies on survival. However, as patients in the various treatment groups also had different prognostic features comparison between treatments was difficult. Over 90% of patients receiving tamoxifen (Tam) were postmenopausal compared with <20% of those receiving chemotherapy (CT). The latter had more positive nodes (85% vs 54%) and grade III tumours (54% vs 30%) than the Tam group. The combined CT and Tam group had similar characteristics to the CT alone group. The current reported increase in the proportion of women with ER+ tumours is explained by immunohistochemical analysis of ER and screening programmes. ER status was unrelated to survival in patients with small, low grade, node-negative tumours which was no different from that expected for age-matched women taken from the general population. The value of adjuvant treatment in these patients is therefore questionable. In those given any adjuvant treatment, survival of women with ER+ tumours was prolonged, with the greatest effect being seen in those receiving Tam. Patients with ER- tumours benefited from CT but the addition of Tam to CT improved survival only in those with ER+ tumours. ER status is now established as a major predictive factor for treatment selection in primary disease. Studies of prognostic and predictive markers may be invalidated by use of adjuvant therapy and selection criteria for different treatments. Survival will be influenced by both tumour biology and therapy. This important consideration must be remembered when analysing new markers, particularly in small studies.

Changes in cell length consequent on depolarization in single left ventricular myocytes from guinea-pigs with pressure-overload left ventricular hypertrophy.

Cell length was measured in single guinea-pig left ventricular myocytes by using a high-resolution photodiode array. Step depolarizations from a holding potential of -45 mV were applied using a switch-clamp technique with 2 M KCl microelectrodes, which were devoid of Ca2+ buffering. Comparison was made between myocytes from sham-operated guinea-pigs and guinea-pigs with mild pressure-overload left ventricular hypertrophy induced by infra-renal aortic constriction. The relation between cell shortening and membrane voltage was bell shaped, and a phasic component of shortening was evident at the range of potentials over which the L-type calcium current was activated. Mean cell shortening was increased in the hypertrophy group, and was maximal at +15 mV in both groups (control, 7.6 +/- 0.9 microns, n = 11, hypertrophy 11.0 +/- 1.2 microns, n = 20, p < 0.05). The latency to the onset of contraction was significantly shorter in the hypertrophy myocytes at -25 mV and at potentials positive to +50 mV. The relation between time-to-peak shortening and voltage showed a trend to shorter times in the hypertrophy group. At very positive potentials a slow component of contraction was identified which was relatively larger in the hypertrophy myocytes. This finding is consistent with increased calcium entry via sarcolemmal sodium-calcium exchange in the myocytes from the hypertrophy group.

Epidemiology and significance of atrial fibrillation.

Atrial fibrillation (AF) is the most common sustained arrhythmia, affecting an estimated 2.2 million adults in the United States. The median age of people with AF is 75, and it affects 8.8% of the US population > 80 years of age. Prevalence data from other countries are presented. Direct comparisons are limited by study design, but rough comparisons suggest that the prevalence of AF in Europe is similar to the prevalence in the United States, whereas the prevalence in Asia may be lower. The limited comparative data underscore our lack of understanding of AF risk factors and complications in racial subgroups and in developing countries. AF increases stroke risk 5-fold. The clinical features that predict higher risk of stroke in AF are prior stroke, hypertension, advancing age, diabetes, and congestive heart failure. Predicting which patients with atrial fibrillation are at the highest risk of stroke remains a challenge. Echocardiographic findings have been investigated to assist in the risk stratification of patients with AF. Despite evidence from clinical trials that anticoagulation with warfarin reduces stroke incidence and even mortality, anticoagulation remains underutilized, especially in the elderly. Improvement in the rate of anticoagulation in patients with AF at risk of stroke can be expected to decrease the complications and mortality of AF.

Effects of captopril on membrane current and contraction in single ventricular myocytes from guinea-pig.

1. Single guinea-pig ventricular myocytes were voltage-clamped and cell length was measured with a photodiode array. 2. Captopril (1 x 10(-5) M) reduced both peak early current and active shortening in response to a depolarizing clamp pulse along a similar time course. 3. From a holding potential of around -45 mV peak early inward current was reduced by 37 +/- 9% (P less than 0.001) on exposure to captopril. The early current-voltage relationship was shifted outwards by captopril indicating a reduction in membrane conductance through the L-type calcium channel (ICa). 4. The amplitude of cell shortening in response to depolarizing voltage steps was reduced but the voltage-dependence of contraction after captopril was unchanged. 5. A small negative shift of the potential at which ICa was half-activated was observed after captopril. There was no change in the voltage-dependence of the inactivation variable or in the time-dependence of repriming for ICa. 6. The actions of captopril on ICa and developed shortening were dose-dependent and took place in the same proportion when Ica was increased by isoprenaline. 7. These results are discussed in relation to the effects of captopril on Ica and contraction and to its clinical usage.

Intracoronary administration of streptokinase in a canine model. Disturbance in thromboxane A2-prostacyclin balance.

The potential impact of local intracoronary infusion of streptokinase (SK) on vascular prostaglandin synthetic pathways was studied in a canine model. Control animals (n = 10) underwent left coronary artery (LCA) infusion of 50,000 units SK for 90 minutes; experimental animals (n = 10) underwent LCA infusion of normal saline. Plasma samples for radioimmunoassay (RIA) of prostacyclin (PGI-2) and thromboxane (TXA-2) were obtained from the coronary sinus (CS) as follows: one sample preinfusion, six samples during infusion, and three samples postinfusion in each animal. Comparisons between control and experimental plasma levels of PGI-2 and TXA-2 were made for each sampling time. The PGI-2 levels remained at or below the lower limits of detectability by RIA (the most sensitive assay available) in both control and experimental animals. TXA-2 levels were higher in experimental than in control animals at all sampling times, with the most significant differences occurring in samples 3 (after 30 minutes of infusion, .001 less than P less than .01), 4 (after 45 minutes of infusion, .05 less than P less than .10), and 5 (after 60 minutes of infusion, .02 less than P less than .05). We suggest (1) it is unlikely that any of the beneficial effects of coronary streptokinase infusions are PGI-2-mediated, (2) that the TXA-2 increases in our model may represent a pathophysiologic-biochemical correlate of previously identified morphologic evidence of endothelial damage in animals infused with fibrinolytic agents, and (3) that our findings may indicate that fibrinolytic infusions produce competing effects: lysis of thrombi and endothelial injury with TXA-2 production.(ABSTRACT TRUNCATED AT 250 WORDS)

The effect of thioridazine on the Automatic Clinical Analyzer serum tricyclic anti-depressant screen.

A patient who had ingested thioridazine and flurazepam was brought to the authors' emergency department. Initial laboratory evaluation included a positive result for a serum screening test for tricyclic anti-depressants performed with the DuPont Automatic Clinical Analyzer. This false positive test result caused considerable unnecessary treatment and expense for the patient. The authors have found that a serum thioridazine concentration of 125 ng/mL (within the usual therapeutic range for this drug) will produce a false positive automatic clinical analyzer serum tricyclic anti-depressant screen result. Because thioridazine is the most widely used phenothiazine and is prescribed more frequently than the most widely used tricyclic anti-depressant, it is important to recognize this cause of a false positive result.

Auditory attention in the congenitally blind: where, when and what gets reorganized?

Functional reorganization of auditory attention was studied in 12 congenitally blind subjects and 12 controls using high-density event-related potentials during a highly focused dichotic listening task. Reaction times for the attend-ear intensity-deviant targets were markedly faster for the blind. Brain activity associated with sustained attention (N1 effect, Nd), and with the automatic detection of deviants in an unattended channel (MMN), did not exhibit reorganization. In contrast, marked plasticity changes were reflected in late auditory attentional processing (attend-ear targets), in the form of a prolonged negativity (200-450 ms post-stimulus) that was absent in the sighted subjects. The plasticity changes in the blind had a time course indicating progressive recruitment of parietal and then occipital regions, providing new evidence for cross-modal sensory reorganization in the blind.

Fetomaternal hemorrhage in threatened abortion.

In this study, we compared the incidence of fetomaternal hemorrhage between patients with threatened abortion and a control population of similar gestational age. The study population comprised pregnant patients at less than 20 weeks' gestation who presented to our emergency room with a history of vaginal bleeding without cervical dilatation or passage of tissue. The control population consisted of women presenting for elective pregnancy termination; they were excluded from the study if they gave a history of any antepartum bleeding. The amount of fetomaternal hemorrhage was evaluated using the Kleihauer-Betke acid elution assay. A positive result in our laboratory, as determined by a nonpregnant control group, was a value of 0.07% or more fetal cells. Using this criterion, 11% of the study population had a positive Kleihauer-Betke test, compared with 4% in the pregnant control group. Rho(D) immunoglobulin may be indicated in Rho(D)-negative patients who present with threatened abortion.

Role of conducting polymeric interfaces in promoting biological electron transfer.

In this paper, we explore the role that polymer conductivity and functionality play in determining the nature of molecular recognition at artificial polymer interfaces, as evidenced by electron transfer with the small redox protein, cytochrome c. The relationship is investigated electrochemically using cyclic voltammetry in order to assess the degree of molecular recognition between the biological molecule and carboxyl-functionalized beta-substituted poly(thiophenes) and poly(pyrroles), as well as a co-polymer matrix of these derivatives. In the latter case, the co-polymer film was analysed quantitatively using X-ray photoelectron spectroscopy, and it was found that its composition did not reflect the initial molar ratios of the monomers prior to electrodeposition.

A radioassay for angiotensin converting enzyme.

Current methods for measuring angiotensin converting enzyme activity (EC 3.4.15.1, ACE) are somewhat cumbersome and have limited the general availability of the test. We describe here a simple four-step radioassay for ACE which uses the substrate 14C-Hippurate-L-Histidyl-L-Leucine and measures the product, 14C-Hippurate. We found that incubation at pH 7.0 (Hepes buffer) increased the sensitivity of the test by 50 percent when compared to results obtained with the pH 8.0 buffer normally used for ACE assays. A split sample comparison study between the radioassay and the spectrophotometric method showed good correlation (n = 47; mean, spectrophotometric, 26.0 U/mL; mean, radioassay, 26.1 U/mL; m = 0.86; b = 3.9; r = 0.868). We found that there was no significant difference between the spectrophotometric, kinetic and radioassay (Newman-Keuls multiple range test), but the liquid chromatographic method gave results significantly different from the other methods. The assay for ACE described here combines enhanced technical ease with the sensitivity of a radioassay.

Serum angiotensin converting enzyme activity in patients with psoriasis.

Serum angiotensin converting enzyme activity is frequently increased in patients with active sarcoidosis. In spite of a reported association between sarcoidosis and psoriasis, serum angiotensin converting enzyme activities have not been reported for patients with psoriasis. We found the mean (SD) angiotensin-converting enzyme activity for 51 healthy subjects was 18.6 (5.8) kU/l, but for 52 patients with psoriasis without coexisting sarcoidosis, it was 28.3 (6.7) kU/l. There is a significant difference between these means (p less than 0.01). Forty-two percent (22/52) of the psoriasis patients had an increased serum angiotensin converting activity. Other diseases sometimes associated with an increased serum angiotensin converting enzyme activity were excluded as possible causes of a elevated activity in our patients with psoriasis. We conclude that almost half of the patients with psoriasis will have an elevated serum angiotensin converting enzyme activity, even when coexisting sarcoidosis is absent.