Cohort profile: the ESC EURObservational Research Programme Non-ST-segment elevation myocardial infraction (NSTEMI) Registry

AIMS

The European Society of Cardiology (ESC) EURObservational Research Programme (EORP) Non-ST-segment elevation myocardial infarction (NSTEMI) Registry aims to identify international patterns in NSTEMI management in clinical practice and outcomes against the 2015 ESC Guidelines for the management of acute coronary syndromes in patients presenting without ST-segment-elevation.

METHODS AND RESULTS

Consecutively hospitalised adult NSTEMI patients (n = 3620) were enrolled between 11 March 2019 and 6 March 2021, and individual patient data prospectively collected at 287 centres in 59 participating countries during a two-week enrolment period per centre. The registry collected data relating to baseline characteristics, major outcomes (in-hospital death, acute heart failure, cardiogenic shock, bleeding, stroke/transient ischaemic attack, and 30-day mortality) and guideline-recommended NSTEMI care interventions: electrocardiogram pre- or in-hospital, pre-hospitalization receipt of aspirin, echocardiography, coronary angiography, referral to cardiac rehabilitation, smoking cessation advice, dietary advice, and prescription on discharge of aspirin, P2Y12 inhibition, angiotensin converting enzyme inhibitor (ACEi)/angiotensin receptor blocker (ARB), beta-blocker, and statin.

CONCLUSION

The EORP NSTEMI Registry is an international, prospective registry of care and outcomes of patients treated for NSTEMI, which will provide unique insights into the contemporary management of hospitalised NSTEMI patients, compliance with ESC 2015 NSTEMI Guidelines, and identify potential barriers to optimal management of this common clinical presentation associated with significant morbidity and mortality.

Australian experience with total pancreatectomy with islet autotransplantation to treat chronic pancreatitis

BACKGROUND

This study aimed to describe the clinical outcomes of total pancreatectomy with islet autotransplantation (TP-IAT) in Australia.

METHODS

Individuals selected for TP-IAT surgery according to the Minnesota Criteria (Appendix) without evidence of diabetes were evaluated including time to transplantation from pancreatectomy, islet numbers infused and post-transplantation HbA1c, C-peptide, total daily insulin and analgesic requirement.

RESULTS

Sixteen individuals underwent TP-IAT from Australia and New Zealand between 2010 and 2020. Two recipients are deceased. The median islet equivalents/kg infused was 4244 (interquartile range (IQR) 2290-7300). The median C-peptide 1 month post-TP-IAT was 384 (IQR 210-579) pmol/L and at median 29.5 (IQR 14.5-46.5) months from transplant was 395 (IQR 139-862) pmol/L. Insulin independence was achieved in eight of 15 (53.3%) surviving recipients. A higher islet equivalents transplanted was most strongly associated with the likelihood of insulin independence (P < 0.05). Of the 15 surviving recipients, 14 demonstrated substantial reduction in analgesic requirement.

CONCLUSION

The TP-IAT programme in Australia has been a successful new therapy for the management of individuals with chronic pancreatitis including hereditary forms refractory to medical treatment to improve pain management with 50% insulin independence rates.

Hepatic Ago2-mediated RNA silencing controls energy metabolism linked to AMPK activation and obesity-associated pathophysiology

RNA silencing inhibits mRNA translation. While mRNA translation accounts for the majority of cellular energy expenditure, it is unclear if RNA silencing regulates energy homeostasis. Here, we report that hepatic Argonaute 2 (Ago2)-mediated RNA silencing regulates both intrinsic energy production and consumption and disturbs energy metabolism in the pathogenesis of obesity. Ago2 regulates expression of specific miRNAs including miR-802, miR-103/107, and miR-148a/152, causing metabolic disruption, while simultaneously suppressing the expression of genes regulating glucose and lipid metabolism, including Hnf1β, Cav1, and Ampka1. Liver-specific Ago2-deletion enhances mitochondrial oxidation and ATP consumption associated with mRNA translation, which results in AMPK activation, and improves obesity-associated pathophysiology. Notably, hepatic Ago2-deficiency improves glucose metabolism in conditions of insulin receptor antagonist treatment, high-fat diet challenge, and hepatic AMPKα1-deletion. The regulation of energy metabolism by Ago2 provides a novel paradigm in which RNA silencing plays an integral role in determining basal metabolic activity in obesity-associated sequelae.

An update on cardiac implantable electronic devices for the general physician

Cardiac electronic device implantation is a common and important intervention for patients with tachy-and bradyarrhythmia. An increasing number of patients are receiving more complex devices such as cardiac resynchronisation therapy or devices with a defibrillation function. Over the last 5 years, two new models of cardiac device have emerged, subcutaneous defibrillators and leadless pacemakers. With an ageing population and data demonstrating 2000 per 100,000 of the population aged over 75 years have a cardiac device, it is essential that the general physician remains updated on the common pacemaker indications and available therapies.

Artificial cloud test confirms volcanic ash detection using infrared spectral imaging

Airborne volcanic ash particles are a known hazard to aviation. Currently, there are no means available to detect ash in flight as the particles are too fine (radii < 30 μm) for on-board radar detection and, even in good visibility, ash clouds are difficult or impossible to detect by eye. The economic cost and societal impact of the April/May 2010 Icelandic eruption of Eyjafjallajökull generated renewed interest in finding ways to identify airborne volcanic ash in order to keep airspace open and avoid aircraft groundings. We have designed and built a bi-spectral, fast-sampling, uncooled infrared camera device (AVOID) to examine its ability to detect volcanic ash from commercial jet aircraft at distances of more than 50 km ahead. Here we report results of an experiment conducted over the Atlantic Ocean, off the coast of France, confirming the ability of the device to detect and quantify volcanic ash in an artificial ash cloud created by dispersal of volcanic ash from a second aircraft. A third aircraft was used to measure the ash in situ using optical particle counters. The cloud was composed of very fine ash (mean radii ~10 μm) collected from Iceland immediately after the Eyjafjallajökull eruption and had a vertical thickness of ~200 m, a width of ~2 km and length of between 2 and 12 km. Concentrations of ~200 μg m⁻³ were identified by AVOID at distances from ~20 km to ~70 km. For the first time, airborne remote detection of volcanic ash has been successfully demonstrated from a long-range flight test aircraft.

Multicenter Australian trial of islet transplantation: improving accessibility and outcomes

Whilst initial rates of insulin independence following islet transplantation are encouraging, long-term function using the Edmonton Protocol remains a concern. The aim of this single-arm, multicenter study was to evaluate an immunosuppressive protocol of initial antithymocyte globulin (ATG), tacrolimus and mycophenolate mofetil (MMF) followed by switching to sirolimus and MMF. Islets were cultured for 24 h prior to transplantation. The primary end-point was an HbA1c of <7% and cessation of severe hypoglycemia. Seventeen recipients were followed for ≥ 12 months. Nine islet preparations were transported interstate for transplantation. Similar outcomes were achieved at all three centers. Fourteen of the 17 (82%) recipients achieved the primary end-point. Nine (53%) recipients achieved insulin independence for a median of 26 months (range 7-39 months) and 6 (35%) remain insulin independent. All recipients were C-peptide positive for at least 3 months. All subjects with unstimulated C-peptide >0.2 nmol/L had cessation of severe hypoglycemia. Nine of the 17 recipients tolerated switching from tacrolimus to sirolimus with similar graft outcomes. There was a small but significant reduction in renal function in the first 12 months. The combination of islet culture, ATG, tacrolimus and MMF is a viable alternative for islet transplantation.

Circulating endothelial progenitor cell numbers are not associated with donor organ age or allograft vasculopathy in cardiac transplant recipients

INTRODUCTION

Increasing age is associated with reduced numbers of circulating endothelial progenitor cells (EPCs). It is unclear whether this relates to depletion or impairment of bone marrow progenitors, or to deficient mobilization signals from aging tissues. In cardiac transplant patients, one previous study has reported an association between circulating EPCs and the risk of cardiac allograft vasculopathy (CAV). We investigated whether increased donor heart age, a strong risk factor for CAV, was associated with reduced circulating EPC numbers in a group of cardiac transplant recipients matched for factors which influence EPC numbers, but with maximally discordant donor heart ages.

METHODS

We identified 32 patient pairs, matched for factors known to influence EPC numbers, but who had discordant donor heart ages by at least 20 years. EPCs were quantified using flow cytometry for absolute counts of cells expressing all the combinations of CD45, CD34, CD133 and the kinase domain receptor (KDR).

RESULTS

There were no significant differences in the numbers of circulating EPCs between patients with old or young donor heart age. There was no association between the presence of CAV and circulating EPC numbers.

CONCLUSIONS

We suggest that the increased susceptibility to CAV of older donor hearts is not mediated via circulating EPCs. Our results are consistent with the theory that the normal age-related decline in EPC numbers relates to bone marrow aging rather than failure of target tissues to induce EPC mobilization.

gamma-Interferon signaling in pancreatic beta-cells is persistent but can be terminated by overexpression of suppressor of cytokine signaling-1

Proinflammatory cytokines, including gamma-interferon (IFN-gamma), have been implicated in the destruction of beta-cells in autoimmune diabetes. IFN-gamma signaling is transient in some cell types, but there is indirect evidence that it may be prolonged in beta-cells. In this study, we have shown that IFN-gamma signaling, measured by signal transducer and activator of transcription-1 (STAT1) activation and the expression of IFN-gamma-responsive genes, is persistent in beta-cells for as long as the cytokine is present. Because members of the suppressor of cytokine signaling (SOCS) family may regulate the duration of IFN-gamma signaling, their expression was investigated in beta-cells. We found that cytokine-inducible SH2-containing protein, SOCS-1, and SOCS-2 are expressed in primary islets and NIT-1 insulinoma cells, both at the mRNA and protein levels, after treatment with IFN-gamma and other proinflammatory cytokines. Transfected SOCS-1 was found to inhibit responses to IFN-gamma in NIT-1 insulinoma cells, including STAT1 activation, class I major histocompatibility complex upregulation, and IFN-gamma-induced cell death, but only when expressed at levels higher than those found in untransfected cells. Consistent with this, IFN-gamma signaling was not affected in SOCS-1-deficient beta-cells. Therefore, persistent IFN-gamma signaling in beta-cells is associated with SOCS-1 expression that is not sufficient to terminate signaling. Because overexpression of SOCS-1 can suppress responses to IFN-gamma, this may be a useful strategy for protecting beta-cells from cytotoxicity mediated by IFN-gamma and possibly other proinflammatory cytokines.

Virus-induced autoimmune diabetes: most beta-cells die through inflammatory cytokines and not perforin from autoreactive (anti-viral) cytotoxic T-lymphocytes

Autoimmune diabetes is caused by selective loss of insulin-producing pancreatic beta-cells. The main factors directly implicated in beta-cell death are autoreactive, cytotoxic (islet-antigen specific) T-lymphocytes (CTL), and inflammatory cytokines. In this study, we have used an antigen-specific model of virally induced autoimmune diabetes to demonstrate that even high numbers of autoreactive CTL are unable to lyse beta-cells by perforin unless major histocompatibility complex class I is upregulated on islets. This requires the presence of inflammatory cytokines induced by viral infection of the exocrine pancreas but not of the beta-cells. Unexpectedly, we found that the resulting perforin-mediated killing of beta-cells by autoreactive CTL is not sufficient to lead to clinically overt diabetes in vivo, and it is not an absolute prerequisite for the development of insulitis, as shown by studies in perforin-deficient transgenic mice. In turn, destruction of beta-cells also requires a direct effect of gamma-interferon (IFN-gamma), which is likely to be in synergy with other cytokines, as shown in double transgenic mice that express a mutated IFN-gamma receptor on their beta-cells in addition to the viral (target) antigen and do not develop diabetes. Thus, destruction of most beta-cells occurs as cytokine-mediated death and requires IFN-gama in addition to perforin. Understanding these kinetics could be of high conceptual importance for the design of suitable interventions in prediabetic individuals at risk to develop type 1 diabetes.

Beta cell destruction in the development of autoimmune diabetes in the non-obese diabetic (NOD) mouse

In the non-obese diabetic (NOD) mouse model of Type 1 (insulin-dependent) diabetes, evidence suggests that pancreatic beta cells are destroyed in part by apoptotic mechanisms. The precise mechanisms of beta cell destruction leading to diabetes remain unclear. The NOD mouse has been studied to gain insight into the cellular and molecular mediators of beta cell death, which are discussed in this review. Perforin, secreted by CD8(+) T cells, remains one of the only molecules confirmed to be implicated in beta cell death in the NOD mouse. There are many other molecules, including Fas ligand and cytokines such as interferon-gamma, interleukin-1 and tumor necrosis factor-alpha, which may lead to beta cell destruction either directly or indirectly via regulation of toxic molecules such as nitric oxide. As beta cell death can occur in the absence of perforin, these other factors, in addition to other as yet unidentified factors, may be important in the development of diabetes. Effective protection of NOD mice from beta cell destruction may therefore require inhibition of multiple effector mechanisms.

Protective effect of CTLA4Ig secreted by transgenic fetal pancreas allografts

BACKGROUND

Pancreas allotransplantation offers a cure for insulin-dependent diabetes mellitus. Systemic immunosuppression used to prevent immune destruction of the graft has side-effects, including increased susceptibility to infection and neoplasia. These unwanted effects may be limited by engineering the graft to secrete immunomodulatory molecules, to achieve local immunosuppression. Several studies have shown that transient local CTLA4Ig results in partial protection of allogeneic grafts. Our intent has been to determine whether sustained secretion of transgenic CTLA4Ig from pancreatic islets is able to protect against allograft rejection.

METHODS AND RESULTS

Mouse CTLA4 (test=CTLA4Ig) or CD5 leader sequence (control=CD5LIg) was fused to the Fc of mouse IgG2c, and expressed transgenically under the control of the rat insulin promoter in C57BL/6 mice carrying the bml mutation of H-2K(b) (B6.C-H-2(bm1)). This resulted in expression in pancreatic islets. We used ELISA quantification of transgene products secreted into the supernatants of cultured fetal pancreata to select high (CTLA4Ig(hi)) and low (CTLA4Ig(lo)) expresser transgenic mice. Cultured fetal pancreata were transplanted under the kidney capsule of wholly allogeneic CBA recipient mice. CTLA4Ig(hi) but not CTLA4Ig(lo) expresser grafts showed enhanced survival compared with control CD5LIg grafts at 6 weeks posttransplant, provided the recipient mice were transiently depleted of CD4 T cells (by a single low-dose injection of GK1.5) before transplantation.

CONCLUSIONS

Sustained local secretion of CTLA4Ig from transgenic grafts in combination with transient systemic CD4 T-cell depletion can enhance allograft acceptance.

The beta cell in autoimmune diabetes: many mechanisms and pathways of loss

Death of pancreatic beta cells is the final step in the pathogenesis of type 1 diabetes before it becomes clinically apparent. Applying recent basic research about how cells die to the clinical problem of diabetes is a current opportunity and challenge. To date, perforin is the only factor definitely implicated in beta-cell killing in the non-obese diabetic (NOD) mouse model, although some perforin-deficient NOD mice develop diabetes. Our results suggest that other factors that cause beta-cell death remain to be identified.

Correlations of Henry's Law Gas-Solid Virial Coefficients and Chromatographic Retention Times for Hydrocarbons and Halocarbons Adsorbed on Carbopack C Carbon

Second gas-solid virial coefficients were determined at 403.5 +/- 0.5 K for 6 adsorbates, including butane, chloroform, trichlorofluoromethane (Freon 11), bromochloromethane, 1-chloro-2-methylpropane, and dibromodifluoromethane. For another 11 adsorbates, including dichlorodifluoromethane (Freon 12), chlorodifluoromethane (Freon 22), methyl chloride, methylene chloride, propane, n-pentane, n-hexane, carbon tetrachloride, 1,2-dichloropropane, butyl chloride, and cyclohexane, B(2s) was measured over a range of temperatures between 308 and 494 K. These values were found using gas-solid chromatography with Carbopack C (Supelco Inc.), a graphitized carbon black powder, as the adsorbent. We find that both the ln B(2s) values and the gas-solid interaction energies are effectively correlated with adsorbate-calculated molar refractivity, r(2) = 0.947 and r(2) = 0.964, respectively. Dipole moment alone provides a nearly random correlation of ln B(2s) and, if used with molar refractivity, gives r(2) = 0.970 for the 17 hydrocarbon and alkyl halide (halocarbon) adsorbates. A theoretical equation was developed that predicts a quantitative structure retention relationship (QSRR) used to correlate ln B(2s) values with molar refractivity. B(2s) values are directly proportional to the retention times of the adsorbates. Using one-surface and two-surface models, a calculation of the surface area of the Carbopack C for each of the 17 adsorbates provided a check on the consistency of the analysis as the adsorbate was varied. Copyright 1999 Academic Press.

Evidence that beta cell death in the nonobese diabetic mouse is Fas independent

Recent studies suggest that Fas expression on pancreatic beta cells may be important in the development of autoimmune diabetes in the nonobese diabetic (NOD) mouse. To address this, pancreatic islets from NOD mice were analyzed by flow cytometry to directly identify which cells express Fas and Fas ligand (FasL) ex vivo and after in vitro culture with cytokines. Fas expression was not detected on beta cells isolated from young (35 days) NOD mice. In vitro, incubation of NOD mouse islets with both IL-1 and IFN-gamma was required to achieve sufficient Fas expression and sensitivity for islets to be susceptible to lysis by soluble FasL. In islets isolated from older (>/=125 days) NOD mice, Fas expression was detected on a limited number of beta cells (1-5%). FasL was not detected on beta cells from either NOD or Fas-deficient MRLlpr/lpr islets. Also, both NOD and MRLlpr/lpr islets were equally susceptible to cytokine-induced cell death. This eliminates the possibility that cytokine-treated murine islet cells commit "suicide" due to simultaneous expression of Fas and FasL. Last, we show that NO is not required for cytokine-induced Fas expression and Fas-mediated apoptosis of islet cells. These findings indicate that beta cells can be killed by Fas-dependent cytotoxicity; however, our results raise further doubts about the clinical significance of Fas-mediated beta cell destruction because few Fas-positive cells were isolated immediately before the development of diabetes.

Tumor necrosis factor-alpha-activated cell death pathways in NIT-1 insulinoma cells and primary pancreatic beta cells

Tumor necrosis factor-alpha (TNFalpha) is a potential mediator of beta cell destruction in insulin-dependent diabetes mellitus. We have studied TNF-responsive pathways leading to apoptosis in beta cells. Primary beta cells express low levels of the type I TNF receptor (TNFR1) but do not express the type 2 receptor (TNFR2). Evidence for TNFR1 expression on beta cells came from flow cytometry using monoclonal antibodies specific for TNFR1 and TNFR2 and from RT-PCR of beta cell RNA. NIT-1 insulinoma cells similarly expressed TNFR1 (at higher levels than primary beta cells) as detected by flow cytometry and radio-binding studies. TNF induced NF-kappaB activation in both primary islet cells and NIT-1 cells. Apoptosis in response to TNFalpha was observed in NIT-1 cells whereas apoptosis of primary beta cells required both TNFalpha and interferon-gamma (IFNgamma). Apoptosis could be prevented in NIT-1 cells by expression of dominant negative Fas-associating protein with death domain (dnFADD). Apoptosis in NIT-1 cells was increased by coincubation with IFNgamma, which also increased caspase 1 expression. These data show that TNF-activated pathways capable of inducing apoptotic cell death are present in beta cells. Caspase activation is the dominant pathway of TNF-induced cell death in NIT-1 cells and may be an important mechanism of beta cell damage in insulin-dependent diabetes mellitus.

IFN-gamma action on pancreatic beta cells causes class I MHC upregulation but not diabetes

We have generated transgenic nonobese diabetic (NOD) mice expressing dominant negative mutant IFN-gamma receptors on pancreatic beta cells to investigate whether the direct effects of IFN-gamma on beta cells contribute to autoimmune diabetes. We have also quantitated by flow cytometry the rise in class I MHC on beta cells of NOD mice with increasing age and degree of islet inflammatory infiltrate. Class I MHC expression increases gradually with age in wild-type NOD mice; however, no such increase is observed in the transgenic beta cells. The transgenic mice develop diabetes at a similar rate to that of wild-type animals. This study dissociates class I MHC upregulation from progression to diabetes, shows that the rise in class I MHC is due to local IFN-gamma action, and eliminates beta cells as the targets of IFN-gamma in autoimmune diabetes.

Two-Surface Virial Analysis of Alkane Adsorption on Carbopack C with and without Hydrogen Treatment

Second gas-solid virial coefficients for propane, butane, pentane, and hexane were found for Carbopack C and Carbopack C-HT (Supelco Inc.) within the temperature range of 323 to 471 K using gas-solid chromatography in the Henry's law region of adsorption. Carbopack C and Carbopack C-HT are both graphitized carbon black powders. Treatment of Carbopack C with hydrogen at 1273 K converts it to Carbopack C-HT and is believed to remove certain high energy sites or "hot spots" from the carbon surface. These two surfaces provide appropriate model systems to test a two-surface virial analysis. Surface areas for both powders were calculated using a uniform single-surface model and a two-surface model. Only the two-surface virial model which is based on gas-solid interaction parameters determined by an iterative process and numerical integration gave reasonable areas for the two surfaces: 13.2 and 13.9 m2/g for Carbopack C and Carbopack C-HT, respectively. The percentage of high energy sites on the Carbopack C was found to be 2.6% and for Carbopack C-HT was found to be 1.5%. The gas-solid interaction energy for the high energy sites was found to be 1.80 times greater than the corresponding value for the low energy portion of the surface. In addition, the gas-solid adsorption energies for the four alkane adsorbates were found to have a linear correlation with their boiling points and with the ratio of their critical temperatures divided by the square root of their critical pressures. Copyright 1997 Academic Press. Copyright 1997Academic Press

Interferon regulatory factor 1 is induced by interferon-gamma equally in neurons and glial cells

Class I MHC protein is induced in glia but not mature neurons by IFN-gamma. We have compared IFN-gamma signal transduction in these populations. There were identical levels of STAT1 homodimers and IRF-1 by gel-shift and IRF-1 mRNA was induced equally. However class I MHC, beta2-microglobulin and interleukin 1-beta converting enzyme mRNA levels were greatly reduced in neurons. These experiments show that there is no defect in expression of IRF-1 in response to IFN-gamma in mature mouse neurons but that insufficient class I MHC gene expression is induced for detectable cell surface protein expression.

Protection of NIT-1 pancreatic beta-cells from immune attack by inhibition of NF-kappaB

We have recently observed that inhibition of NF-kappaB in NIT-1 insulinoma cells protects them from tumour necrosis factor (TNF)-induced cell death in vitro, possibly because expression of interleukin-1 (IL-1)beta-converting enzyme (ICE), a member of the cysteine protease pathway of cell death, is decreased. In the current study we have examined the effect of the same inhibitor of NF-kappaB on class I major histocompatibility complex (MHC) protein expression in NIT-1 cells and shown that inhibition of NF-kappaB activation decreased basal and TNF-induced class I MHC levels. Although inducible nitric oxide synthase (iNOS) may also be inhibited by inhibition of NF-kappaB, this could not be demonstrated in NIT-1/delta sp cells because wild-type NIT-1 cells express very little iNOS. When NIT-1/delta sp12 cells, expressing high levels of the NF-kappaB inhibitor, are transplanted into immunodeficient NOD/scid mice, tumorigenesis and death by hypoglycemia proceed similarly to untransfected NIT-1 cells. Untransfected NIT-1 cells were killed by co-transfer of splenic T cells from diabetic but not non-diabetic NOD mice. NIT-1/delta sp12 cells were protected from killing in vivo by T cells from diabetic mice, in that tumours developed in four out of five mice and the kinetics of tumour development were not significantly delayed. NIT-1/delta sp12 cells were not protected from killing by T cells from mice previously primed with NIT-1 cells. In conclusion, inhibition of NF-kappaB is likely to suppress several different pathways of immune-mediated cell death in beta-cells and protects NIT-1 cells from immune attack by diabetogenic T cells in vivo. Inhibition of NF-kappaB is a potentially effective strategy for protection of pancreatic beta-cells in autoimmune diabetes.

Transgenic expression of mouse proinsulin II prevents diabetes in nonobese diabetic mice

IDDM in humans and in nonobese diabetic (NOD) mice is a T-cell-dependent autoimmune disease in which the beta-cells of the pancreatic islets are destroyed. Several putative beta-cell autoantigens have been identified, but insulin and its precursor, proinsulin, are the only ones that are beta-cell specific. (Pro)insulin may be a key autoantigen in IDDM. To address the role of proinsulin in the development of IDDM, we generated NOD mice transgenic for the mouse proinsulin II gene driven off a major histocompatibility complex (MHC) class II promoter to direct expression of the transgene to MHC class II bearing cells, including those in the thymus, with the aim of deleting proinsulin-reactive T-cells. The mononuclear cell infiltration of the islets (insulitis) is almost completely absent, and diabetes is prevented in these transgenic NOD mice. The mononuclear cell infiltration of the salivary glands (sialitis) and immune responses to ovalbumin (OVA) are not altered, indicating that the protective effect of the transgene is specific for islet pathology and not due to general immunosuppression. We conclude that autoimmunity to proinsulin plays a pivotal role in the development of IDDM.

RIP-beta 2-microglobulin transgene expression restores insulitis, but not diabetes, in beta 2-microglobulin null nonobese diabetic mice

Beta2m-deficient nonobese diabetic (NODbeta2mnull) do not develop insulitis or diabetes. Expression of a beta2m transgene controlled by the rat insulin promoter (RIP-beta2m) in NODbeta2mnull mice resulted in reconstitution of IFN-gamma-inducible cell surface MHC class I protein on pancreatic beta-cells. These mice developed insulitis, but did not develop diabetes. Transfer of T cells from diabetic NOD mice to NODbeta2mnull recipients resulted in insulitis, which took several months to progress to diabetes. In contrast, transgenic RIP-beta2m/NODbeta2mnull mice with islet MHC class I reconstitution developed diabetes rapidly after transfer of diabetic NOD spleen cells. Administration of cyclophosphamide, which accelerates diabetes in NOD mice, resulted in 43% of RIPbeta2m/NODbeta2mnull mice becoming diabetic compared with 75% of wild-type mice and 0% of NODbeta2mnull mice. Acceleration of diabetes by cyclophosphamide was prevented by anti-CD8 mAb treatment. FACS analysis of peripheral blood and lymphoid organs from transgene-bearing animals did not show an increase in the number of CD8+ T cells compared with that in NODbeta2mnull mice. In summary, beta-cell expression of beta2m in NODbeta2mnull mice resulted in a return of insulitis, but not spontaneous diabetes. These studies demonstrate that beta2m and cell surface MHC class I expression on beta-cells are essential for the initiation of diabetes in the NOD mouse and further confirm that efficient progression to diabetes requires both CD4+ and CD8+ T cells.

RIP-beta 2-microglobulin transgene expression restores insulitis, but not diabetes, in beta 2-microglobulin null nonobese diabetic mice

Beta2m-deficient nonobese diabetic (NODbeta2mnull) do not develop insulitis or diabetes. Expression of a beta2m transgene controlled by the rat insulin promoter (RIP-beta2m) in NODbeta2mnull mice resulted in reconstitution of IFN-gamma-inducible cell surface MHC class I protein on pancreatic beta-cells. These mice developed insulitis, but did not develop diabetes. Transfer of T cells from diabetic NOD mice to NODbeta2mnull recipients resulted in insulitis, which took several months to progress to diabetes. In contrast, transgenic RIP-beta2m/NODbeta2mnull mice with islet MHC class I reconstitution developed diabetes rapidly after transfer of diabetic NOD spleen cells. Administration of cyclophosphamide, which accelerates diabetes in NOD mice, resulted in 43% of RIPbeta2m/NODbeta2mnull mice becoming diabetic compared with 75% of wild-type mice and 0% of NODbeta2mnull mice. Acceleration of diabetes by cyclophosphamide was prevented by anti-CD8 mAb treatment. FACS analysis of peripheral blood and lymphoid organs from transgene-bearing animals did not show an increase in the number of CD8+ T cells compared with that in NODbeta2mnull mice. In summary, beta-cell expression of beta2m in NODbeta2mnull mice resulted in a return of insulitis, but not spontaneous diabetes. These studies demonstrate that beta2m and cell surface MHC class I expression on beta-cells are essential for the initiation of diabetes in the NOD mouse and further confirm that efficient progression to diabetes requires both CD4+ and CD8+ T cells.

Experiencing a shame response as a precursor to violence

The shame response is a primitive physiological response to a rejection of oneself by another. The discomfort of this response may vary from intense physical pain to one that is barely noticeable, if at all. When this pain is sufficient, it causes anger that may be directed outward against another or inward against oneself. The intensity of the shame response, hence the intensity of the pain and anger, is related to the significance of the other, the significance of witnesses to the rejection, one's vulnerability, whether or not the rejection is of oneself or an aspect of oneself, and if the rejection comes as a surprise. When most intense (i.e., most painful), the shame response may include a tightness of the throat, nausea, stomach pain, and a sense that the contents of one's chest and abdomen are collapsing, exploding, or imploding. In reviewing what preceded an act of violence, it is necessary to determine whether the assailant had experienced a shame response and how intense it was. Understanding that a shame response can lead to anger and violence allows for the prevention of violence. This requires that individuals do not experience rejections that are so painful as to lead to violence.

Heterodimerization of the Drosophila ecdysone receptor with retinoid X receptor and ultraspiracle

Ecdysone in Drosophila has been a paradigm for steroid hormones since its ability to induce gene activity directly was demonstrated by its effects on moulting and polytene chromosome puffing. The ecdysone receptor (EcR) was recently confirmed as a member of the nuclear receptor superfamily by cloning and characterization in a Drosophila cell line. Here we show that EcR needs to heterodimerize with either the retinoid X receptor (RXR) or its Drosophila homologue, ultraspiracle (USP), for DNA binding and transactivation. These results place the ecdysone receptor in the heterodimerizing class of the nuclear receptor superfamily and demonstrate that the role of RXR/USP as a central and promiscuous partner in mediating the activity of these receptors is highly conserved. Whereas EcR-USP DNA-binding activity is unaffected by hormone, EcR-RXR DNA-binding activity is stimulated by either ecdysteroid or 9-cis-retinoic acid, demonstrating that hormone can play a role in heterodimer stabilization.

Risk factor changes after cessation of intervention in the Multiple Risk Factor Intervention Trial. The MRFIT Research Group

BACKGROUND

The degree of maintenance of risk factor changes observed in post-trial follow-up of participants in the Multiple Risk Factor Intervention Trial (MRFIT) provides insights into long-term determinants of preventive behaviors, as well as post-trial mortality differentials.

METHODS

Nine hundred eighty-nine former MRFIT participants at four clinical centers were invited to be reexamined 2-3.5 years after the end of this 6- to 8-year trial. Seventy percent came to the clinics for measurements of systolic and diastolic blood pressure, plasma lipids and lipoproteins, serum thiocyanate, and dietary food frequency. With the addition of phone interviews, 82% provided self-report data on cigarette smoking and use of antihypertensive drugs.

RESULTS

Comparison of Special Intervention (SI) and Usual Care (UC) groups showed that differences persisted for total (6.5 mg/dl, P = 0.02) and low-density lipoprotein cholesterol (5.4 mg/dl, P = 0.04), and for diastolic blood pressure (1.6 mm Hg, P = 0.02). Differences were not significant for systolic blood pressure (1.8 mm Hg, P = 0.12), cigarette smoking, and serum thiocyanate. The plasma cholesterol difference represented 70% of the value at the end of intervention, and food frequency profiles were consistent with maintenance of an SI - UC difference. Loss of the SI - UC difference in smoking was attributable to both UC cessation and SI recidivism. The blood pressure difference was not attributable to different proportions of SI and UC men on medications, but possibly to differences in diuretic doses, use of multiple drugs, and adherence. There was a persisting contrast in use of specific diuretics, with more frequent use of chlorthalidone and less of hydrochlorothiazide in the SI group.

CONCLUSION

These findings suggest that cholesterol-lowering dietary changes are self-sustaining, while smoking cessation is less so, and may require continued intervention. Finally, the SI - UC differences in use of specific diuretics remains one hypothesis for explaining a portion of post-trial mortality trends.

The diagnosis of Duchenne and Becker muscular dystrophies: two years' experience in a comprehensive carrier screening and prenatal diagnostic laboratory

This article describes the diagnostic algorithm being used for the management of the 148 families affected by Duchenne or Becker muscular dystrophy who are known to the Molecular Neurogenetics Laboratory in the Department of Neuropathology, Royal Perth Hospital. In 60 families from whom DNA has been obtained, 41 mutations (39 deletions and two duplications) of the Duchenne muscular dystrophy gene (DMD) have been identified by means of complementary DNA (cDNA) probes. DNA-based screening has clarified the carrier status of 45 at-risk women, and 13 pregnancies have been monitored. In addition, cDNA screening of all relevant patients with autosomal recessive muscular dystrophy, spinal muscular atrophy or limb-girdle muscular dystrophy facilitated the correct diagnosis of Becker muscular dystrophy in three patients.

Physiologic and symptomatic responses of cardiac patients to resistance exercise

The purpose of this study was to investigate the symptomatic and physiologic responses during moderate to heavy resistance exercise in a population with coronary artery disease. After at least 12 weeks of aerobic training without experiencing complications, 15 male cardiac patients were selected for the study. Approximately one week after a graded exercise test (GXT), each patient's maximal voluntary contraction (MVC) was determined on seven upper-body Nautilus machines. Resistance exercises, consisting of two sets of seven repetitions at a submaximal intensity (75% MVC) for each exercise, were then performed on two nonconsecutive occasions; symptomatic, hemodynamic, and electrocardiographic responses were recorded and analyzed for patients both on and off beta-blockers. During the MVC and submaximal exercise trials, no significant untoward hemodynamic change was noted with heart rate, systolic blood pressure, diastolic blood pressure, or rate pressure product, and no patient complained of angina or developed ischemic electrocardiographic changes. However, three incidences of premature ventricular contractions (PVCs) occurred. During the GXT, there were 13 incidences of angina, ischemia, or PVCs. Patients taking beta-blockers had significantly lower (p less than .01) values for heart rate and rate pressure product during the GXT, MVC, and submaximal trials. These results suggest that clinically stable, aerobically trained cardiac patients may perform moderate to heavy resistance exercises without experiencing complications.

Differentiation of Becker muscular dystrophy from limb-girdle muscular dystrophy and Kugelberg-Welander disease using a cDNA probe

A 31-year-old man previously investigated for a neuromuscular disorder was diagnosed as having either limb-girdle dystrophy, spinal muscular atrophy, or Becker muscular dystrophy. Extensive clinical and special neurological investigations failed to clarify this differential diagnosis. However, recent DNA studies have shown a deletion of the dystrophin gene, thereby providing an unequivocal diagnosis of Becker muscular dystrophy. The application of molecular genetic techniques in the diagnosis of inherited neuromuscular disorders is discussed.

Role of support networks in maintenance of improved cardiovascular health status

This study was undertaken to clarify the relationship between maintaining an improved cardiovascular health status and social support networks. Two hundred and ninety participants from a national trial that was carried out to specify the impact of reducing risk for cardiovascular disease were rescreened 3 years after completion of the trial. Original risk status of the participants was compared to risk status at the end to identify who had an improved risk status (n = 204). Risk status of 204 improvers was calculated from the rescreening data to identify maintainers (n = 63) and nonmaintainers (n = 143). No significant differences were found between maintainers and nonmaintainers in sociodemographic status, or in level of general support. Highly significant differences were found for four types of support provided specifically for risk reduction: information/advice (P = 0.002), appraisal (P = 0.004), emotional support (P = 0.01) and availability (P = 0.019). Most of these differences in support were accounted for by the larger support network identified by the maintainers. In addition, compared to nonmaintainers, maintainers' networks were more family-centered (P = 0.012), and were correspondingly more dense (P = 0.021). A discriminant function analysis using the significant variables was able to predict maintenance in 72% of the cases. The significant variables also accounted for 10% of the variance between maintainers and nonmaintainers. The implications of this study are: (1) assessment of support should be specific to the health outcome being studied: (2) research on the impact of social environment on health status will benefit from clearly specifying individual components of social support and social networks; (3) amount of social support provided is related to size of the network and relationship of supporter to the at-risk individual; (4) because social support and social networks account for a small but significant amount of the variance between maintainers and nonmaintainers, these concepts should be included in patient assessments prior to developing a treatment or maintenance plan.

Human melanoma cells: functional modulation by calciotropic hormones

Four human melanoma cell lines were examined for their responsiveness to the hormones 1,25-dihydroxyvitamin D3 (1,25[OH]2D3), calcitonin, and parathyroid hormone (1-34). Cells from each of the 4 lines contained high affinity binding sites for 1,25(OH)2D3. At high cell densities, binding of 1,25(OH)2D3 was diminished due to a decrease in receptor number with no apparent change in affinity. Preincubation with 1,25(OH)2D3 (10(-10) to 10(-8) M) increased tyrosinase activity 1.3- to 3.2-fold and 25-hydroxyvitamin D3-24-hydroxylase activity 1.4- to 10-fold. Human calcitonin (0.82 to 82.5 ng/well) raised the intracellular concentration of cyclic adenosine monophosphate 1.4- to 9.4-fold. Tyrosinase activity increased in response to calcitonin in 2 of the cell lines, decreased in the third, and showed no change in the fourth. Human parathyroid hormone (1-34) in concentrations of 1 to 10 ng/ml produced no significant changes in cyclic adenosine monophosphate accumulation, cell numbers, or tyrosinase activity in any of the cell lines. This study indicates that the phenotype of human melanoma cells can be modulated by the calciotropic hormones 1,25(OH)2D3 and calcitonin.

Overall and coronary heart disease mortality rates in relation to major risk factors in 325,348 men screened for the MRFIT. Multiple Risk Factor Intervention Trial

The influence of risk factors on CHD and all-cause mortality rates in 35- to 57-year-old men is examined by means of data on 325,348 white men who were screened for the MRFIT. This large data set permits an unusually detailed analysis of factors associated with the 6968 deaths, including 2426 ascribed to CHD, that were detected in the Social Security Administration data set during 6 years of follow-up. Simple cross classification of the data confirms the independent effect of serum cholesterol concentration, diastolic blood pressure, and cigarette smoking as risk factors for CHD and all-cause mortality rates. A distinct escalation of risk is noted for combinations of these risk factors. The strength of the association of each of the risk factors with CHD and all-cause mortality rates diminished with increasing age, although the number of excess deaths attributable to the risk factors increased because of the higher death rates in older men. Comparison of these findings with those observed in the five populations studied in the Pooling Project revealed an overall similarity in the risk relationships. It is estimated that elimination of these risk factors has the potential for reducing the CHD mortality rate by two thirds in 35- to 45-year old men, and by one half in 46- to 57-year-old men.

The Birmingham Tuberculosis Drug Resistance Register, 1956-1983

The findings of the Birmingham Drug Resistance Register are recorded for the years 1956-83. In native born patients initial drug resistance was common up to 1969, but few new cases were discovered after 1970. In the immigrant population a peak of male discoveries was noted in 1968 and a peak of female discoveries in 1979, probably due to immigration patterns. In the native born, single drug resistance was the more common pattern; no initial isoniazid resistance has been detected in this group since 1970. The immigrant patients showed a higher proportion of initial multiple drug resistance. The proportion of culture positive respiratory tuberculosis from which drug resistant bacilli were isolated is given for the years 1976-1983. For native born males this was 1%, for native born females 0.6%, for immigrant males 5.1% and for immigrant females 6.5%. The detections of acquired drug resistance were high in 1956, but since 1970 have fallen to low levels, as has the pool of chronic excretors of drug resistant tubercle bacilli.

Clinical-electrocardiographic correlates of newly acquired left bundle branch block: the Framingham Study

To determine whether any associated electrocardiographic findings in persons with newly acquired complete left bundle branch block (LBBB) correlate with the prevalence of associated clinically apparent cardiovascular abnormalities, electrocardiograms (ECGs) from all 55 members of the Framingham Study cohort in whom LBBB developed during 18 years of routine prospective biennial examinations were reviewed. A QRS axis left of or equal to 0 degrees, left atrial conduction delay and an inverted T wave in lead V6 on the first ECG with LBBB, and an abnormal ECG in the Framingham examination preceding the appearance of LBBB each correlated with the prevalence of systemic hypertension, cardiomegaly, coronary heart disease and congestive heart failure. However, neither the PR interval nor the duration of the QRS complex on the first ECG with LBBB correlated with the prevalence of any of the associated cardiovascular abnormalities. The 8 patients with neither left atrial conduction delay nor a QRS axis left of or equal to 0 degrees on the first Framingham ECG with LBBB nor an abnormal ECG on the examination preceding the appearance of LBBB were 6 times more likely to remain free of all of the clinical cardiovascular abnormalities than the 47 patients with 1 or more of these 3 electrocardiographic findings (p less than 0.001).

Coronary heart disease in police officers participating in the Normative Aging Study

There is evidence suggesting that male police officers are at a higher risk of developing coronary heart disease than males in the general population. Thus, 1648 men (including 220 police officers and 1428 non-police officers) were followed for 10 years to determine the incidence of coronary heart disease. Subjects were participants of the Normative Aging Study, a longitudinal study of aging initiated in 1963 at the Veterans Administration Outpatient Clinic in Boston, Massachusetts. Comparison of police officers and non-police officers showed no statistically significant differences in the crude incidence rates of coronary heart disease (myocardial infarction, angina pectoris, or death from coronary heart disease) and myocardial infarction alone. When baseline age, serum cholesterol, blood pressure, cigarette smoking, and body mass index were taken into consideration in multiple logistic regression analyses, the lack of significant differences between groups persisted. Police officers relative to non-police officers had an adjusted risk ratio (odds ratio) of 1.4 (95% confidence interval = 0.7-2.4) for coronary heart disease and 1.0 (95% confidence interval = 0.4-2.4) for myocardial infarction. Differences between occupational groups were not statistically significant.

The relationship of the baseline ECG to blood pressure change

A total of 1,090 male participants (aged 23 to 80 years) of the Normative Aging Study who had baseline BP less than 140/90 mm Hg were observed prospectively for ten years. Blood pressures were taken at five- and ten-year follow-up examinations. Multiple linear regression analysis indicated that baseline levels of systolic pressure, age, R-wave amplitude (aVL), hematocrit, T-wave amplitude (V5), and S-wave amplitude (V4, V5, and V6) were statistically significant predictors of systolic pressure change. Baseline levels of diastolic pressure, R-wave amplitude (aVL), and hematocrit were statistically significant predictors of diastolic pressure change. Multiple logistic regression analysis showed that baseline levels of BP, S-wave amplitude (V1, V2, and V3), body mass index, R-wave amplitude (V4, V5, and V6), and T-wave amplitude (V5) were statistically significant predictors of subsequent hypertension. Whether the identified ECG amplitudes are an indicator of early increases in peripheral resistance or a function of neurohumoral factors, or both, is unknown.

The relationship of the U wave to the 10-year incidence of myocardial infarction

The relationship between the baseline electrocardiogram and 10-year incidence of myocardial infarction was examined in a cohort of 1013 men. The men were participants in the Normative Aging Study, a longitudinal study of aging initiated in 1963 at the Veterans Administration Outpatient Clinic in Boston, Massachusetts. Absence of the U wave among these men yielded a relative risk estimate of myocardial infarction of 2.7 as compared to men with a U wave present (95% confidence interval, 1.4-5.2). This association persisted when standard coronary risk factors (cholesterol, blood pressure, and cigarette smoking) were taken into consideration in a multivariate analysis. The results support the conclusion that an abnormality in the electrocardiogram considered to be of little importance indicates an increased risk of myocardial infarction independent of known coronary risk factors.

Smoking status and the electrocardiogram: a cross-sectional and longitudinal study

Previous cross-sectional studies have shown age trends in electrocardiographic wave patterns, including leftward shift in frontal plane axis and decreases in R, S, and T wave amplitudes with age. The effects of smoking on electrocardiographic measurements have also been examined. Findings of several studies vary and include possible smoking-induced changes in T wave amplitude and frontal plane axis measurements. To examine both cross-sectionally and longitudinally the effects of cigarette smoking on electrocardiographic measurements, serial recordings obtained 5 yr apart were taken from 702 healthy male participants of the Normative Aging Study, who were 23-74 yr of age at their first examination. These men were classified as current smokers (at both baseline and follow-up examinations, N = 291), former smokers (men who stopped smoking prior to the baseline examination, N = 203), or never smokers (at any time, N = 208). At baseline, P-R interval duration was shorter in current smokers than in former or never smokers. Longitudinal results indicated that R, S, and T wave amplitudes decreased at greater rates in smokers than in nonsmokers. These findings suggest that changes in the electrocardiogram attributed to aging may be modified by smoking.

Factors in predicting blood pressure change

A total of 1166 male participants (ages 23--80 years) of the Normative Aging Study who had baseline blood pressure less than 140/90 mm Hg were followed prospectively for 10 years. Blood pressures were taken at 5- and 10-year follow-up examinations. Multiple linear regression analysis indicated that baseline levels of systolic pressure, hematocrit, subscapular skinfold thickness and age were significant predictors of systolic pressure change during the follow-up period. Baseline levels of diastolic pressure, hematocrit, and body mass index were significant predictors of diastolic pressure change. Multiple logistic regression analysis revealed that only baseline blood pressure and hematocrit were significant predictors of subsequent blood pressure elevation to more than 159 mm Hg systolic or 94 mm Hg diastolic. Although the mechanisms by which hematocrit and body build affect blood pressure are unknown, these results suggest that identifying hypertension-prone subjects and delaying or preventing hypertension may be possible.

Comparative features of newly acquired left and right bundle branch block in the general population: the Framingham study

Cardiovascular abnormalities were prospectively identified in all 55 persons who acquired left bundle branch block and all 70 persons who acquired right bundle branch block during 18 years of follow-up of the Framingham Study cohort. Those with left and right bundle branch block did not differ from each other in the overall prevalence of either hypertension, clinical coronary disease or diabetes. In men, but not in women, left bundle branch block was associated with a significantly greater prevalence of cardiac enlargement and congestive failure than was right bundle branch block. A trend suggesting a higher mortality rate from cardiovascular disease in those with left than in those with right bundle branch block was more apparent in men than in women. It is concluded that in the general adult population, men who acquire left bundle branch block are more likely to have or subsequently acquire advanced cardiovascular abnormalities than are men who acquire right bundle branch block. In women, however, the clinical correlates of the two conduction abnormalities are similar.

Newly acquired right bundle-branch block: The Framingham Study

Cardiovascular abnormalities were identified prospectively in all 70 persons who developed complete right bundle-branch block (RBBB) in The Framingham Study during 18 years of biennial follow-up. Most were hypertensive before the appearance of RBBB. Although the initial appearance of RBBB was usually unaccompanied by overt clinical events, the subsequent incidence of coronary disease and congestive failure was two and one-half and four times greater, respectively, than that in matched control subjects without RBBB. The incidence of cardiovascular disease mortality was almost three times greater in persons who developed RBBB than in an age-matched sample of the population-at-large. This excess of cardiovascular disease mortality was related primarily to the high prevalence of associated cardiovascular abnormalities. Only 21% remained free from clinically apparent cardiovascular abnormalities. A QRS duration of greater than or equal to 130 ms and a QRS axis between -45 degrees and -90 degrees identified those most likely to have associated cardiovascular abnormalities.