Strontium isotopes in the atmosphere, geosphere and hydrosphere: Developing a systematic "fingerprinting" framework of rocks and water in sedimentary basins in eastern Australia.

Understanding the connection between aquifers, aquitards, and groundwater-dependant ecosystems remains a key challenge when developing a conceptual hydrogeological model. The aim of this study was to develop a systematic strontium isotope (87Sr/86Sr) fingerprinting framework of rocks and water within the sedimentary Surat and Clarence-Moreton basins (SCM basins) in eastern Australia - an area of extensive coal seam gas development and high potential for aquifer and groundwater-surface water connectivity. To do this, new groundwater samples (n = 298) were collected, analyzed and integrated with published data (n = 154) from the basins' major sedimentary, volcanic and alluvial aquifers, including the major coal seam gas target, the Walloon Coal Measures. Samples were also analyzed from rainfall (n = 2) and surface water (n = 40). In addition, rock core samples (n = 39) from exploration and stratigraphic wells were analyzed to determine the range of Sr isotope composition from host rocks. The analyses of cores demonstrate a distinct and systematic contrast in 87Sr/86Sr between different hydrogeological units. This confirms that all major hydrogeological units have a narrow range with unique 87Sr/86Sr population characteristics that are useful for guiding conceptual model development. Comparison with selected hydrochemical and groundwater age tracers (14C and 36Cl) suggests only limited changes of 87Sr/86Sr from recharge beds to the deeper parts of the basins or with a decrease in natural 14C and 36Cl tracer content along flow paths. Stream sampling during baseflow conditions confirms that 87Sr/86Sr in surface waters are similar to those of the underlying bedrock formations. We demonstrated that 87Sr/86Sr analyses of rocks and water provide a powerful hydrostratigraphic and chemostratigraphic fingerprinting framework in the SCM basins, enabling reliable assessments of plausible aquifer and groundwater-surface water interconnectivity pathways. Applied in other complex multi-aquifer sedimentary basins in Australia, and globally, a similar approach can help to constrain conceptual hydrogeological models and facilitate improved water resource management.

[Efficacy and safety of treatment of acute ischemic stroke with glycoprotein IIb/IIIa receptor blocker in routine clinical practice]. / Wirksamkeit und Sicherheit einer Akuttherapie mit GPIIb/IIIa-Rezeptorblockern bei ischämischem zerebralem Insult in der klinisch-internistischen Routine.

BACKGROUND: Platelet aggregation plays an important pathophysiological role in the incidence of myocardial infarction and ischemic stroke. The expression of glycoprotein IIb/IIIa receptors on the surface of activated platelets is the final common pathway of platelet aggregation. PATIENTS AND METHODS: Encouraged by the favorable outcome in acute coronary syndromes and by preliminary results, which substantiate the efficacy and safety of GP IIa/III antagonists (GP) in ischemic stroke, we treated 21 cases/20 patients (13 male, 7 female, age 39-79 y.) and conducted a retrospective study using a clinical graduation scale (Modified Rankin Scale MRS). Patients received tirofiban (n = 18) or eptifibatide (n = 3) in the usual cardiological dose 3 h (0.5-8 h) after beginning of symptoms together with "full dose " heparin (n = 8) or "low dose" heparin (n = 12) in the acute phase, with aspirin 100 mg (n = 4), Clopidrogel 75 mg (n = 5), aspirin + clopidogrel (n = 4) in the chronic phase. All patients had a cranial CT, 95% an echocardiography and Doppler sonography of the carotid artery system and some cranial MRI (43%). RESULTS: There was no significant clinical deterioration. All except one patient showed a rapid and impressive improvement during the first 24 h after initiation of treatment (median MRS pre/post 3/1). CONCLUSION: The results with GP in acute ischemic stroke are promising and further studies should be initiated using especially tirofiban, but with monitoring by cerebral diffusion-weighted MRI before and after treatment.

Diltiazem improves cardiac function and exercise capacity in patients with idiopathic dilated cardiomyopathy. Results of the Diltiazem in Dilated Cardiomyopathy Trial.

BACKGROUND: Evidence is arising that calcium antagonists in idiopathic dilated cardiomyopathy (IDC) may have beneficial effects on virus-induced cardiopathology, alcohol toxicity, micro-circulatory disorders, and impaired calcium cycling, all possibly involved in the pathogenesis of the disease. Thus, the effect of adjunct diltiazem (60 to 90 mg TID) on standard treatment was investigated. METHODS AND RESULTS: The Diltiazem in Dilated Cardiomyopathy (DiDi) trial was a randomized, double-blind, placebo-controlled, multicenter trial of 186 patients (92 receiving diltiazem, 94 receiving placebo) with IDC diagnosed by coronary angiography, catheterization of the left side of the heart, and a left ventricular ejection fraction of < 0.50 (mean, 0.34 +/- 0.11). The effect of adjunct diltiazem treatment on transplant listing-free survival, hemodynamics, exercise capacity, and subjective status was investigated. During the 24-month study period, 33 patients dropped out of the study; 153 patients finished the study protocol. Twenty-seven patients died or had a listing for heart transplantation: 16 in the placebo group and 11 in the diltiazem group. The transplant listing-free survival rate was 85% for diltiazem and 80% for placebo recipients (P = .444). After 24 months, only diltiazem significantly increased cardiac index at rest (P = .01) and under a workload (P = .02), systolic and diastolic pressures (P = .003 and P = .004), stroke volume index (P = .003), and stroke work index (P = .000) and decreased both pulmonary artery pressure under workload (P = .007) and heart rate (P = .001). Diltiazem also increased exercise capacity (P = .002) and subjective well-being (P = .01). Adverse reactions were minor and evenly distributed in both groups, except for an increase in the PQ interval in the diltiazem group. CONCLUSIONS: In patients with IDC, the adjunct therapy of diltiazem improves cardiac function, exercise capacity, and subjective status without deleterious effects on transplant listing-free survival.

[A 17-years follow-up study after closed mitral commissurotomy (author's transl)]. / Verlaufsstudie bis 17 Jahre nach Mitralkommissurotomie.

410 patients were operated upon by closed mitral commissurotomy in 1961-62. Of this group, 224 patients were followed up until 1978. The actuarial survival rate after 16 to 17 years postoperatively was 58%. Overall 43 patients were reoperated (second commissurotomy or mitral valve replacement). The cumulative reoperation rate of these patients was 1.5% per year. The mortality rate in patients with reoperation was 1.2% per year, without reoperation 2% per year. 87 patients are still alive 17 years after mitral commissurotomy without reoperation. 59% of this group belong to functional class II or I (NYHA). Most of them have combined mitral valve disease with predominant mitral stenosis. Atrial fibrillation was present in 33% (n = 29) preoperatively and in 58% (n = 50) postoperatively at the end of the study. Only 20% of all patients were on anticoagulant therapy. Nevertheless, the total embolic rate (5.7%) and the cumulative embolic rate (0.2% per year) remained low. The good long-term results show that mitral commissurotomy is an effective therapeutic approach in patients with mitral stenosis.