Association of air pollutants, weather variables, and myocardial infarction incidence in Berlin. A study of the Berlin Brandenburg Myocardial Infarction Registry (B2HIR) based on 17873 cases

Background

Harmful health effects of air pollutants have long been assumed. Respective associations with respiratory diseases have frequently been reported. Recently, studies also pointed at possible links between air pollution and cardiovascular disease. Currently, nitric oxide (NOx) and particulate matter are of concern in Germany.

Purpose

To investigate the association of NOx, particulate matter (PM10), and weather variables with the incidence of myocardial infarction (MI) in Berlin.

Methods

The Berlin Brandenburg myocardial infarction registry (B2HIR) is documenting symptom onset, patient characteristics, comorbidity, procedural data, and outcome of patients with acute MI (onset ≤24h before admission) in Berlin and Brandenburg. From 2008 to 2014 (study period) the stable number of enrolling cardiology departments enabled epidemiologic analyses. Daily (aggregate and variable-specific) MI incidence was assessed for the study period. The government of Berlin provides detailed regional air pollution data (BLUME network). Daily and local NOx and PM10 concentrations were assessed and grouped according to regions (downtown, main roads, suburbs). Preceding days (single and 3 day average) values were also assorted to every single day. Ambient temperature, precipitation, and sunshine duration were assessed from the Berlin-Tempelhof weather station. Bivariate correlations and Poisson regression were calculated to examine associations between air pollutants, weather parameters, and MI incidence.

Results

17873 MI cases were included over 7 years. Bivariate correlations and the Poisson regression model revealed a highly significant independent association of the overall MI incidence with same day NOx concentrations (mean values across all measuring stations) and with average PM10 concentration over three preceding days. Based on regression coefficient and interquartile range of pollutant concentrations, MI incidence variation with same day NOx was 3.2% (p<0.001) and variation with three preceding days PM10 was 4.8% (p<0.001). Daily peak ambient temperature was inversely related to MI incidence (p<0.001), whereas for sunshine duration and precipitations no independent association could be identified. Interestingly, the MI incidence in current smokers was unaffected (p=0.145 and p=0.104, respectively) by NOx and PM10 pollution.

Conclusion

This study is the first to show significant associations between the air pollutants NOx (same day level) and PM10 (3 day preceding average level) and MI incidence in Berlin. MI incidence varied with these pollutants at single digit percentage points. A causal relationship appears likely, as continuously self-intoxicating smokers did not exhibit this association.

Funding Acknowledgement

Type of funding sources: None.

Quality of life 3 and 12 months after acute pulmonary embolism: analysis of 617 patients from the prospective multicentre FOCUS study

Background

Few data are available on the long-term course and predictors of quality of life (QoL) after acute pulmonary embolism (PE).

Aims

To evaluate the kinetics and determinants of QoL at 3 and 12 months after acute PE.

Methods

The Follow-Up after acute pulmonary embolism (FOCUS) study prospectively followed consecutive adult patients with objectively diagnosed PE. For this analysis, we considered patients who completed the Pulmonary Embolism QoL (PEmb-QoL) Questionnaire at two predefined visits 3 and 12 months after PE. PEmb-QoL, studied as total score and in its six dimensions, ranges from 0% (best QoL) to 100% (worst QoL). We studied the course of PEmb-QoL and the impact of baseline characteristics using multivariable linear regression.

Results

In 617 included patients (44% women, median age 62 years), overall QoL improved from 3 to 12 months, with a decrease of the mean PEmb-QoL score from 25.3% to 21.5% (p-value <0.001). Intra-individual correlation between PEmb-QoL score at 3 and 12 months was high; Figure A. The improvement was consistent across all PEmb-QoL dimensions; Figure B. Female sex, cardiopulmonary diseases, and higher body mass index were the main factors associated with a worse QoL; Table. Age and smoking affected QoL only at 12 months. The improvement in QoL was faster in patients without cardiopulmonary diseases (−4.2%; 95% CI: −5.2% to −3.1%), without previous VTE (−4.3%; −5.5% to −3.2%), and in non-smokers (−4.2%; −5.3% to −3.1%).

Conclusions

In a large cohort of patients with pulmonary embolism, we quantified the improvement of QoL between 3 and 12 months after diagnosis. We identified factors independently associated with lower QoL and slower recovery of QoL that may reflect special patient needs. These estimates may facilitate the planning and interpretation of clinical trials with QoL as a study outcome.

Figure 1

Funding Acknowledgement

Type of funding source: Public grant(s) – National budget only. Main funding source(s): University Medical Center of the Johannes Gutenberg University, Mainz, Germany; German Federal Ministry of Education and Research

[Pulmonary hypertension associated with left heart disease: recommendations of the Cologne Consensus Conference 2016]

The 2015 European Guidelines on Diagnosis and Treatment of Pulmonary Hypertension are also valid for Germany. While the guidelines contain detailed recommendations regarding pulmonary arterial hypertension (PAH), they contain only a relatively short paragraph on other, much more common forms of PH such as PH due to left heart disease. Despite the lack of data, targeted PAH treatments are increasingly being used for PH associated with left heart disease. This development is of concern because of limited ressources and the need to base treatments on scientific evidence. On the other hand, PH is a frequent problem that is highly relevant for morbidity and mortality in patients with left heart disease, representing an unmet need of targeted PH therapies. It that sense, the practical implementation of the European Guidelines in Germany requires the consideration of several specific issues and already existing novel data. This requires a detailed commentary to the guidelines, and in some aspects an update already appears necessary. In June 2016, a Consensus Conference organized by the PH working groups of the German Society of Cardiology (DGK), the German Society of Respiratory Medicine (DGP) and the German Society of Pediatric Cardiology (DGPK) was held in Cologne, Germany. This conference aimed to solve practical and controversial issues surrounding the implementation of the European Guidelines in Germany. To this end, several working groups were initiated, one of which was specifically dedicated to PH associated with left heart disease. This article summarizes the results and recommendations of this working group.

[Deterministic record linkage with indirect identifiers: data of the Berlin Myocardial Infarction Registry and the AOK Nordost for patients with myocardial infarction]

AIM OF THE STUDY

How can 2 pseudonymised data sets be linked? Using the example of data from the Berlin Myocardial Infarction Registry and from a German sickness fund (AOK Nordost) we will demonstrate how record linkage can be achieved without personal identifiers.

METHODS

In different steps the method of deterministic record linkage with indirect identifiers: age, sex, hospital admission date and time, will be explained.

RESULTS

We were able to show that 80.6% of the expected maximum number of patients were matched with our approach. As a result we had no duplicate matches in the linkage process, where one AOK patient was linked to 2 or more BMIR patients or vice versa. The matching variables produced enough uniqueness to be used as indirect patient identifiers.

CONCLUSION

Deterministic record linkage with the following indirect indicators: age, sex, hospital admission date and time was possible in our study of patients with myocardial infarction in a circumscribed geographical region, which limited the number of cases and avoided mismatches.

[Structure of the Australian system of 'Diagnosis Related Groups' regarding cardiovascular diseases and corresponding cost weights in Germany]

BACKGROUND

An adapted system of 'Diagnosis Related Groups' (DRG's) will be introduced for Germany at the beginning of 2003. This article focuses on the structure of the Australian DRG system (AR-DRG 4.1) regarding the diseases of the cardiovascular system and corresponding cost weights in Germany (G-DRG 1.0).

METHODS

Cardiac diagnoses, procedures and cost weights (with a different base rate) were compared between the Australian and German DRG's.

RESULTS

Categories and procedures for diagnostics and therapies are shown regarding coronary interventions, electrophysiological strategies including implantation of pacemakers and cardioverter/ defibrillators, hybrid treatment modalities, transcatheter closure of interatrial/-ventricular communications as well as interventions during intensive care treatment.

Transcatheter closure of muscular ventricular septal defects in two patients after myocardial infarction

Acquired muscular ventricular septal defects (MVSD) after myocardial infarction (MI) can lead to right heart failure and cardiogenic shock with high mortality. Early surgical therapy is often difficult to perform but can reduce the mortality. The closure of congenital septal defects is performed with high safety. Therefore, the interventional closure of an acquired post-MI VSD might be feasible and of potential benefit. To date, experiences with closure of post-MI MVSDs are minimal. We report on two patients with post-MI VSD.

Comparison of the relaxation effect in vitro of nitroglycerin vs. fenoterol on human myometrial strips

AIMS

Substance dose-related comparison of relaxation effect of nitroglycerin (GTN) and the beta 2-mimetic substance fenoterol in human myometrial tissue.

METHODS

Test criterion is the isometric force development of isolated human myometrial strips. These muscle strips were removed from the lower uterine segment at cesarean section. Fenoterol in concentrations of 3 x 10(-8)-10(-5) mol/l or GTN in concentrations of 1.7 x 10(-8)-5.8 x 10(-4) mol/l were applied to the 2 x 2 x 10-mm strips, which were fixed and maintained in tissue baths. The curves were plotted on line. The integral or the "area under the curve" (AUC) served as the parameter for muscle strip activity.

RESULTS

A total of 100 strips from 20 patients were used. GTN demonstrated a significant relaxation effect in the in vitro model on human myometrial strips from pregnant women already treated with oxytocin. The effect was able to be enhanced to a point where oxytocin-induced contractions were completely absent. A relatively clear connection was demonstrated between dose and effect whereby increased muscle relaxation resulted at increased concentrations. Compared to GTN application, muscle strip relaxation was less pronounced under fenoterol; a complete inhibition of myometrial activity was not achieved under fenoterol.

CONCLUSIONS

With respect to relaxation of the myometrial tissue samples the NO donor GTN is at least as potent as the standard tocolytic agent fenoterol in the in vitro model.

Neuropathological correlates of dysarthria in progressive supranuclear palsy

BACKGROUND

The dysarthria of progressive supranuclear palsy consists of prominent hypokinetic and spastic components with less prominent ataxic components.

OBJECTIVE

To correlate the types of dysarthria with neuropathological changes in patients with progressive supranuclear palsy.

DESIGN AND METHODS

In 14 patients with progressive supranuclear palsy, we correlated the perceptual speech findings with the neuropathological findings. A dysarthria assessment was performed a mean +/- SD of 31 +/- 15 months (range, 10-53 months) before death. The deviant speech dimensions were rated on a scale of 0 (normal) to 3 (severe). The neuropathological examination consisted of semiquantitative analysis of neuronal loss and gliosis by investigators (A.A.F.S., and L.A.B.) blinded to the clinical findings. Correlation and linear regression analysis were used to correlate the severity of the hypokinetic, spastic, and ataxic components with the degree of neuronal loss and gliosis in predetermined anatomical sites.

RESULTS

All patients had hypokinetic and spastic dysarthria, and 9 also had ataxic components. The severity of the hypokinetic components was significantly correlated with the degree of neuronal loss and gliosis in the substantia nigra pars compacta (r = 0.61, P =.02) and pars reticulata (r = 0.64, P =.01) but not in the subthalamic nucleus (r = 0.51, P =.07) or the striatum or globus pallidus (/r/<0.34, P>.20). The severity of the spastic and ataxic components was not significantly correlated with the neuropathological changes in the frontal cortex (r = 0.20, P =.50) and cerebellum (/r/<0.28, P>.33), respectively.

CONCLUSION

The hypokinetic dysarthria of progressive supranuclear palsy may result from degenerative changes in the substantia nigra pars compacta and pars reticulata and not from changes in the striatum or globus pallidus.

Effects of iloprost inhalation on exercise capacity and ventilatory efficiency in patients with primary pulmonary hypertension

BACKGROUND

The continuous infusion of prostacyclin has been shown to improve exercise capacity and survival in patients with primary pulmonary hypertension (PPH). Inhalation of iloprost, a stable analog of prostacyclin, might be an alternative therapy for PPH, selectively acting on the pulmonary vascular bed through ventilation-matched alveolar deposition of the drug. We investigated the short-term effects of iloprost inhalation on exercise capacity and gas exchange in patients with PPH.

METHODS AND RESULTS

In 11 patients with PPH, we performed 2 consecutive cardiopulmonary exercise tests before and after the inhalation of 17 microgram of iloprost. Patients had marked pulmonary hypertension (mean pulmonary artery pressure 65 mm Hg), and inhalation resulted in a decrease in pulmonary vascular resistance (1509 versus 1175 dyne. s(-1). cm(-5), P<0.05). Arterial blood gases remained unchanged (PaO(2) 69.3 versus 66.8 mm Hg; PaCO(2) 29.6 versus 28.8 mm Hg). Iloprost significantly (P<0.05) improved exercise duration (379 versus 438 seconds), peak oxygen uptake (12.8 versus 14.2 mL. kg(-1). min(-1)), VE-versus-V CO(2) slope (58 versus 51.4).

CONCLUSIONS

The present data show that iloprost inhalation exerts pulmonary vasodilatation and improves symptoms and exercise capacity in patients with PPH. The data also suggest that iloprost inhalation is a suitable treatment for PPH. Whether these effects are maintained during long-term treatment and are paralleled by improvement in prognosis remains to be determined.

Relationship between impaired pulmonary diffusion and cardiopulmonary exercise capacity after heart transplantation

STUDY OBJECTIVES

Diffusion impairment and reduced performance in cardiopulmonary exercise testing (CPX) have been found in patients after heart transplantation. The pathogenesis of these abnormalities is unclear. In particular, the contribution of pulmonary interstitial changes has not yet been verified.

DESIGN

We analyzed pulmonary function tests, high-resolution CT (HRCT), echocardiography, left heart catheterization, and CPX in transplanted patients.

PATIENTS

Forty long-term survivors were studied at a median of 47 months (range, 12 to 89 months) after heart transplantation.

RESULTS

Diffusion was impaired in 40% (transfer factor for carbon monoxide) or 82.5% (carbon monoxide transfer coefficient) of the patients. Diffusion impairment was caused by a decreased diffusing capacity of the alveolar capillary membrane in 89% and/or by a decreased blood volume of the alveolar capillaries in 46% of cases. In five patients (12.5%), CT revealed interstitial lung changes. These patients did not have different values of diffusion capacity. Maximal oxygen uptake and ventilatory efficiency during exercise (minute ventilation/carbon dioxide output slope) were impaired in 92% and 46% of the cases, respectively.

CONCLUSIONS

Our data show that the diffusion abnormalities are caused by an impaired diffusion status of the alveolar capillary membrane. Interstitial changes detectable in HRCT were found not to be involved in this process. The reduced performance in CPX in our long-term survivors is caused by pulmonary perfusion abnormalities and low tidal volume, which is due to the deconditioning of respiratory muscle, rather than by interstitial changes or diffusion abnormalities.

Pulmonary artery stenosis 5 years after single lung transplantation in primary pulmonary hypertension

This is a case report about a 56-year-old female patient with primary pulmonary hypertension who underwent single, right lung transplantation. Five years postoperatively she developed signs of right heart failure. History and physical examination suggested pulmonary artery stenosis. Diagnosis was confirmed by pulmonary angiography. Percutaneous placement of a balloon expandable stent normalized pulmonary artery pressure.

Pituitary adenylate cyclase activating peptides relax human pulmonary arteries by opening of KATP and KCa channels

BACKGROUND

Pituitary adenylate cyclase activating peptides (PACAPs) are potent endothelium independent dilators of human coronary arteries; however, their effects on human pulmonary arteries are unknown.

METHODS

The vasorelaxant effects of PACAP27 on human pulmonary segmental arteries were studied and the specific potassium (K+) channel regulatory mechanisms in the vasorelaxant effects were tested by means of isometric contraction experiments.

RESULTS

PACAP27 produced dose dependent relaxations of 10 microM rings preconstricted with prostaglandin F2 alpha (PGF2 alpha) with half maximal relaxation (IC50) at 17 nM. Pretreatment of the vessels with the ATP sensitive K+ (KATP) channel blocker glibenclamide (1 microM) or with the Ca2+ activated K+ (KCa) channel blocker iberiotoxin (100 nM) inhibited the PACAP27 induced relaxation.

CONCLUSIONS

These results provide evidence that PACAPs are potent vasodilators of human pulmonary arteries and that this relaxation might be mediated by opening of KATP and KCa channels.

Pituitary adenylate-cyclase-activating peptides relax human coronary arteries by activating K(ATP) and K(Ca) channels in smooth muscle cells

Pituitary adenylate-cyclase-activating peptides (PACAPs) are potent dilators of arteries, including human coronary arteries. We tested the importance of specific K+ channel regulatory mechanisms in human arterial smooth muscle relaxation induced by PACAPs, using contraction and patch clamp measurements on human coronary artery vascular smooth muscle cells. PACAP27 and PACAP38 produced dose-dependent relaxations of 5 microM PGF2alpha-preconstricted rings, with half-maximal relaxations at 1.0 nM and 2.0 nM, respectively. Both peptides induced complete relaxation at 100 nM. Pretreatment of the vessels with the ATP-dependent K+ (K(ATP)) channel blocker glibenclamide (1 microM) or with the Ca2+-activated K+ (K(Ca)) channel blocker iberiotoxin (100 nM) inhibited PACAP27-induced relaxation in an additive manner. Moreover, in the patch clamp experiments on freshly isolated cells from human coronary arteries, PACAP27 (100 nM) induced a large, nonrectifying, outward (I(K)(ATP)) K+ current in a proportion of cells and a voltage-dependent outward (I(K)(Ca)) K+ current in other cells. The PACAP27-induced I(K)(ATP) was blocked by glibenclamide (3 microM), while the PACAP27-stimulated I(K)(Ca) was blocked by iberiotoxin (100 nM). These findings provide the first evidence that relaxation of arterial smooth muscle cells by PACAPs is mediated by opening of K(ATP) and K(Ca) channels. The data indicate that both K(ATP) and K(Ca) channels in vascular smooth muscle cells may serve as final common pathway to induce vasorelaxation by endogenous vasoactive signals in man.

Pituitary adenylate cyclase activating peptides are endothelium-independent dilators of human and porcine coronary arteries

The PACAPs have been shown to be potent vasodilators in different animal species. Data in humans are still lacking. Therefore we investigated the effects of PACAP 38, PACAP 27 and VIP on isolated human and porcine coronary arteries (HCA and PCA). Our data show, that the PACAPs are endothelium-independent vasorelaxants, which in HCA are slightly more potent than VIP. The N-terminal shortened peptides PACAP 6-38 and PACAP 6-27 also show relatively potent vasorelaxant effects, acting as partial agonists. Glibenclamide, a selective inhibitor of ATP-sensitive potassium channels, partially reverses the effects of the PACAPs, indicating an involvement of these channels in the mechanism of action.

Effects of prostaglandin E1, prostaglandin E0 and SPM 206 on isolated human coronary arteries

The effects of PGE1, PGE0 and the stable PGE1-analogue SPM 206 on human epicardial coronary arteries were studied in vitro. The tension of the isolated arterial rings was measured isometrically. After precontraction, concentration-response curves with the compounds were performed. PGE1 and SPM 206 elicited concentration-dependent relaxations which are counteracted by a contractile action in higher concentrations. In PGE0, the contractile action occurred even in lower concentrations. This contraction was antagonized by the selective thromboxane A2 antagonist SQ 29,548, resulting in an equipotent relaxation for all three compounds.

Acute influence of beta-adrenergic antagonists on left ventricular diastolic function: contrasting results after administration of celiprolol and metoprolol

Various beta-adrenergic receptor antagonists have different effects on myocardial function. A clinical study was performed in 30 patients with symptomatic coronary artery disease and systemic hypertension to compare the effects of single intravenous doses of 0.15 mg/kg celiprolol (n = 16) (third generation beta-blocking agent) and metoprolol (n = 14) (second generation) on left ventricular diastolic function. Parameters derived from pressure, volume, flow, time intervals and their combination were used to characterise diastolic function. After celiprolol administration, parameters of diastolic myocardial function improve (dp/dtip-; relaxation time constant T1, peak filling rate PFR; first-third filling rate FF1/3 or diastolic wall stress-time integral Sigdiasc) or remain unchanged. In contrast, after metoprolol administration parameters of diastolic function seem to be deteriorated (dp/dtip-, T1; Sigdiasc). This indicates an improvement in myocardial relaxation and filling under the influence of celiprolol but not under metoprolol. The left shift of the pressure-volume loops after celiprolol (n = 13), in contrast to metoprolol, supports this interpretation. Celiprolol did not show any deterioration of diastolic function in patients with coronary heart disease and arterial hypertension under these acute conditions.

Diastolic heart function--pathophysiology, characterization, and therapeutic approaches

In recent years diastolic cardiac function has attracted increasing attention since parameters of diastolic function were found to be altered earlier or more specifically than parameters of systolic function. Diastolic cardiac function is determined by both active (muscular relaxation, redistribution of calcium, synchronization, etc.) and passive (myocardial structure, fibrosis, etc.) factors. As a consequence, a comprehensive assessment of diastolic cardiac function cannot be based on one single parameter. For a complete analysis of diastolic function it is necessary to perform invasive diagnostic procedures involving the measurement of atrial and ventricular pressures, as well as the registration of volume changes with a high time resolution. In addition, it is necessary to measure wall thickness and ventricular configuration, so that apart from filling parameters the stress-strain relationship can be obtained. Noninvasive techniques (Doppler echocardiography, radionuclear ventriculography, apexcardiography) may suggest alterations in diastolic function as well. They ought to be complemented by additional diagnostic procedures (pulmonary pressure, stress testing, etc.). Therapy must consider potentially harmful effects on diastolic function parameters, particularly if changes in myocardial oxygen consumption may result (heart rate, parietal wall stress). Calcium antagonists (verapamil, diltiazem, nifedipine), phosphodiesterase inhibitors (milrinone), beta-adrenergic agonists and antagonists with vasodilating effects (e.g., celiprolol) all have beneficial effects on diastolic myocardial function. A range of diastolic function parameters is being reviewed in the following paper. Their role in the estimation of cardiac function and their responsiveness to therapy in hypertrophy, cardiomyopathy, and coronary heart disease is being discussed.

Infection with HTLV-III/LAV and transfusion-associated acquired immunodeficiency syndrome. Serologic evidence of an association

We studied patients with transfusion-associated acquired immunodeficiency syndrome (AIDS) and their blood donors for serologic evidence of infection with human T-cell lymphotropic virus type III/lymphadenopathy-associated virus with two enzyme-linked immunosorbent assays and a Western blot assay. All 19 patients with AIDS were seropositive by at least one test. In all 28 donor sets containing "high-risk" donors, at least one donor was seropositive by one or more tests. Of 255 donors not considered high risk, two (0.8%) were seropositive by all three tests. When 30 seropositive high-risk donors were evaluated a median of 29 months after donation, four (13%) had developed AIDS and eight (27%) had lymphadenopathy. Our findings support the hypothesis that human T-cell lymphotropic virus type III/lymphadenopathy-associated virus causes AIDS and indicate that seropositive high-risk donors may be at relatively high risk for developing AIDS or related conditions themselves.

Immunological properties of the Gag protein p24 of the acquired immunodeficiency syndrome retrovirus (human T-cell leukemia virus type III)

Antigenic cross-reactivity of human T-cell leukemia virus type III (HTLV-III) with HTLV-I and HTLV-II and other retroviruses was measured by using a stringent homologous competition radioimmunoassay for the Gag protein p24 and a less stringent electrophoretic transfer blot assay. In the competition radioimmunoassay only minimal cross-reactivities were detected between HTLV-III p24 and both HTLV-I and HTLV-II. No cross-reactivity was detected with any other retrovirus. In the electrophoretic transfer blot system using rabbit antibody to HTLV-I, HTLV-II, and HTLV-III, low-level cross-reaction was detected between HTLV-I and HTLV-III and between HTLV-II and HTLV-III. Unlike the cross-reactivity between HTLV-I p24 and HTLV-III p24, which was bidirectional, the one between HTLV-II and HTLV-III was only a one-way reactivity. Antiserum to HTLV-II recognized HTLV-III p24, but the antiserum to HTLV-III did not recognize HTLV-II p24. The results indicate that HTLV-III is a unique retrovirus with a limited homology with HTLV-I and HTLV-II but unrelated to most other retroviruses.

Antibodies reactive with human T-lymphotropic retroviruses (HTLV-III) in the serum of patients with AIDS

In cats, infection with T-lymphotropic retroviruses can cause T-cell proliferation and leukemia or T-cell depletion and immunosuppression. In humans, some highly T4 tropic retroviruses called HTLV-I can cause T-cell proliferation and leukemia. The subgroup HTLV-II also induces T-cell proliferation in vitro, but its role in disease is unclear. Viruses of a third subgroup of human T-lymphotropic retroviruses, collectively designated HTLV-III, have been isolated from cultured cells of 48 patients with acquired immunodeficiency syndrome (AIDS). The biological properties of HTLV-III and immunological analyses of its proteins show that this virus is a member of the HTLV family, and that it is more closely related to HTLV-II than to HTLV-I. Serum samples from 88 percent of patients with AIDS and from 79 percent of homosexual men with signs and symptoms that frequently precede AIDS, but from less than 1 percent of heterosexual subjects, have antibodies reactive against antigens of HTLV-III. The major immune reactivity appears to be directed against p41, the presumed envelope antigen of the virus.

Superoxide dismutase activity in the intestine of the streptozotocin-diabetic rat

Insulin stimulates the production of superoxide and hydrogen peroxide in various tissues. Hydrogen peroxide has been proposed to be an intracellular second messenger for insulin and a moderator of cellular proliferation and differentiation. We previously found that cell proliferation is increased in small intestinal mucosa of streptozotocin-diabetic rats. The current study was undertaken to determine if superoxide dismutase (SOD), the enzyme that converts superoxide to hydrogen peroxide, is altered in the mucosa of the alimentary tract and renal cortex of the diabetic rat, and if so, whether SOD responds to insulin treatment. Total SOD and cyanide-insensitive [manganese-containing SOD (Mn SOD)] SOD were measured by the nitroblue tetrazolium inhibition assay. We studied ad libitum fed animals, where diabetics are hyperphagic and pair-fed animals, where hyperphagia is not present. Since cyclic nucleotides appear to control cell proliferation in some tissues, we also measured cAMP and cGMP in mucosa of the small intestine. In ad libitum fed animals, total SOD was depressed in the mucosa of duodenum, jejunum, and ileum, but not in the cecum or colon of the streptozotocin-diabetic rats. The level of Mn-SOD was not affected by diabetes or insulin treatment, but the cyanide-sensitive [copper- and zinc containing SOD (Cu-Zn SOD] SOD was depressed in the small intestine and colon of diabetic rats. Insulin treatment restored total and Cu-Zn SOD activity in the small intestine to normal and increased Cu-Zn SOD activity in the colon to normal. Pair-fed animals showed the same changes in the SOD activity of jejunal mucosa that were found in ad libitum fed animals. In renal cortex, diabetes did not alter total SOD, but increased Mn SOD and decreased Cu-Zn SOD. Both responses were reversed by insulin treatment. Cyclic nucleotide concentrations were not affected by diabetes. We conclude that SOD enzymes re altered in diabetes, at least in proliferating tissues. Responses are tissue specific. The mucosa of the small intestine and colon show decreased Cu-Zn SOD, the SOD of the cecum is unaffected, and the kidney shows increased Mn SOD and decreased Cu-Zn SOD. The SOD responses of diabetics are reversed by insulin treatment.