Calafiore cardioplegia offers better myocardial protection in adult and senescent rat hearts than Del Nido cardioplegia

OBJECTIVES

We compared the cardioprotective capacity of Del Nido cardioplegia and warm Calafiore blood cardioplegia in an experimental setting during 90 min of ischaemia.

METHODS

20 adult and 20 senescent rat hearts were isolated and mounted on a blood-perfused, pressure-controlled Langendorff apparatus. After a stabilization period, cardiac arrest (90 min) was induced by the administration of either Calafiore (Cala) or Del Nido solution (DNS). While Cala was given warm and intermittently, DNS was given as a cold single shot. During 90 min of reperfusion, cardiac function and metabolism were evaluated and biomarker levels were measured. After the end of the experiment, hearts were prepared for electronmicroscopic investigation.

RESULTS

Hearts exposed to Cala recovered faster during reperfusion compared with hearts administered DNS (Cala vs DNS at 30 min reperfusion: left ventricular developed pressure 72, SD: 22% of baseline (BL) versus 40, SD: 32% of BL, p < .001, and positive derived left ventricular pressure over time was better in both adult and senescent Cala groups (96, SD: 31% of BL) than in the DNS groups (39, SD: 27% of BL, p < .001). Ischaemic contractures were seen in the DNS groups starting after 30 min of ischaemia, whereas no rise in diastolic pressure was observed for the Cala groups. Accordingly, lactate production was higher after DNS (1.23 mg/dl (SD 0.87) than after Cala (0.33 mg/dl (SD 0.68), p = .015) at the beginning of reperfusion. Troponin I levels at the end of reperfusion were higher after DNS treatment in adult hearts (DNS: 287.9 SD: 147.7 ng/mL vs Cala 91.2: SD: 94.7 ng/mL, p = .02) and in senescent hearts (DNS: 376.5 (SD: 162.8) ng/ml versus Cala 104.7 (SD: 150.2) ng/ml, p = .025). Electron microscopy showed that the cellular oedema index was higher in adult DNS hearts (1.2 ± 0.2) than in adult Cala hearts (0.8 ± 0.1, p = .012), whereas the VS ratio was similar (0.18 ± 0.01 vs 0.17 ± 0.03).

CONCLUSION

Calafiore cardioplegia offers better myocardial protection from ischaemia/reperfusion-related damage in isolated perfused adult and senescent rat hearts than Del Nido cardioplegia.

Listeria Monocytogenes-Induced Endogenous Endophthalmitis in an Otherwise Healthy Individual: Rapid PCR-Diagnosis as the Basis for Effective Treatment

Purpose

Listeria monocytogenes is a rare cause of endogenous endophthalmitis. To date 15 cases have been published in the literature. All eyes showed similar clinical features and profound visual loss mainly due to delayed diagnosis.

Methods

An additional case of an otherwise healthy 73 year-old male, who was referred to our hospital because of acute iridocyclitis with secondary glaucoma, is reported. Within a few days the severity of the intraocular infection increased dramatically, resulting in the clinical picture of acute endophthalmitis.

Results

In contrast to most published cases, early identification of the causative pathogen in the aqueous humor after anterior chamber puncture using polymerase chain reaction (PCR) and the initiation of a specific, systemic antibiotic medication, resulted in complete recovery of visual acuity.

Conclusions

PCR is very useful for the identification of the pathogen in intraocular infections.

In vitro antifungal activity of isavuconazole against 345 mucorales isolates collected at study centers in eight countries

Although mucormycoses (formerly zygomycoses) are relatively uncommon, they are associated with high mortality and treatment options are limited. Isavuconazole is a novel, water soluble, broad-spectrum azole in clinical development for the treatment of invasive aspergillosis and candidiasis. The objective of this report was to collate data on the in vitro activity of isavuconazole against a collection of 345 diverse mucorales isolates, collected and tested at eight study centers in europe, mexico and North America. Each study center undertook minimum inhibitory concentration (MIC) susceptibility testing of their isolates, according to EUCAST or CLSI guidelines. Across all study centers, isavuconazole exhibited MIC(50 )values of 1-4 mg/l and MIC(90 )values of 4-16 mg/l against the five genera. There were also marked differences in MIC distributions, which could be ascribed to differences in inoculum and/or endpoint. EUCAST guidelines appeared to generate modal MICs 2-fold higher than CLSI. These results confirm that isavuconazole possesses at least partial antifungal activity against mucorales.

Biosynthesis of constitutive nitric oxide synthase-derived nitric oxide attenuates coronary vasoconstriction and myocardial depression in a model of septic heart failure induced by Staphylococcus aureus alpha-toxin

OBJECTIVE

Myocardial depression, which frequently occurs in the course of septic shock, has been attributed to the cardiodepressant properties of nitric oxide (NO) generated by either the inducible NO synthase (iNOS) or the constitutive isoform (cNOS). We have previously demonstrated that alpha-toxin from Staphylococcus aureus induces thromboxane-mediated vasoconstriction accompanied by severe cardiodepression in isolated rat hearts. In the present study, we investigated the role of NO in the alpha-toxin-induced vascular and contractile abnormalities.

DESIGN

Prospective, experimental study.

SETTING

Research laboratory at a university hospital.

SUBJECTS

Isolated hearts from male Wistar rats.

INTERVENTIONS

Isolated hearts were perfused with purified staphylococcal alpha-toxin for 60 mins.

MEASUREMENTS AND MAIN RESULTS

At a concentration of 0.25 and 0.5 microg/mL, alpha-toxin induced a rise in coronary perfusion pressure, depressed myocardial contractility, and caused edema formation. Simultaneously, a time- and dose-dependent rapid release of NO into the perfusate was noted as quantified by a chemiluminescence technique. L-NMMA, a nonselective inhibitor of NOS, but not PBITU, an iNOS-selective inhibitor, blocked NO synthesis, markedly increased the rise in coronary perfusion pressure and the loss in contractility, and enhanced edema formation in response to alpha-toxin. In contrast, zaprinast, a selective inhibitor of phosphodiesterase type V that is used for stabilization of cyclic guanosine monophosphate, attenuated the toxin-induced coronary vasoconstrictor response and the myocardial depression. L-arginine, the substrate of NOS, had similar, yet less potent, effects as zaprinast and slightly increased the release of NO caused by alpha-toxin. Immunohistochemical analysis of the myocardium at the end of the perfusion period demonstrated a positive staining for cNOS but not for iNOS. In addition, no up-regulation of iNOS mRNA was detected in the tissue of toxin-exposed hearts.

CONCLUSIONS

Staphylococcal alpha-toxin provokes NO biosynthesis via activation of cNOS in rat hearts. NO partly antagonizes the deleterious effects of this pathogenicity factor on coronary vasoregulation and myocardial performance.

Frequency of rpoB mutations inside and outside the cluster I region in rifampin-resistant clinical Mycobacterium tuberculosis isolates

The prevalence of recently described mutation V176F, located in the beginning of the rpoB gene and associated with rifampin resistance and the wild-type cluster I sequence, was determined by analyzing the distribution of rpoB mutations among 80 rifampin (RIF)-resistant Mycobacterium tuberculosis strains isolated in Germany during 1997. The most frequent rpoB mutations were changes in codon 456 (52 isolates, 65%), followed by changes in codon 441 (13 isolates, 16%) and codon 451 (11 isolates, 14%). The V176F mutation was detected in one isolate of the study population and in 5 of 18 RIF-resistant strains with no cluster I mutation from six previously published studies. In three isolates, a mixture of resistant and susceptible subpopulations (heteroresistance) prohibited the detection of rpoB mutations in the initial analysis; however, in these isolates, cluster I mutations could be verified after a passage on RIF-containing medium. IS6110 DNA fingerprinting of 76 strains revealed eight clusters comprising 27 strains with identical restriction fragment length polymorphism patterns that mainly also show identical rpoB mutations and identical or similar drug resistance patterns. In conclusion, our results indicate that the V176F mutation should be included in molecular tests for prediction of RIF resistance in M. tuberculosis. We further demonstrated that heteroresistance caused by a mixture of mycobacterial subpopulations with different susceptibilities to RIF may influence the sensitivity of molecular tests for detection of resistance.

Endotoxin-induced myocardial tumor necrosis factor-alpha synthesis depresses contractility of isolated rat hearts: evidence for a role of sphingosine and cyclooxygenase-2-derived thromboxane production

BACKGROUND

Although endotoxin (lipopolysaccharides, LPS) is recognized as a mediator of septic cardiodepression, its cardiac effects are still not fully elucidated.

METHODS AND RESULTS

Perfusion of isolated rat hearts with LPS for 180 minutes resulted in a decline of left ventricular contractility after 90 minutes, whereas coronary perfusion pressure remained unaffected. This cardiodepression was paralleled by a release of tumor necrosis factor (TNF)-alpha into the perfusate and preceded by myocardial TNF-alpha mRNA upregulation as quantified by real-time polymerase chain reaction. The cardiodepression was abrogated when LPS was perfused with a TNF-alpha antiserum or the ceramidase inhibitor N:-oleoylethanolamine. In contrast, the cardiac release of nitric oxide (NO) was not augmented by LPS. Immunohistochemical studies of LPS-perfused hearts revealed a positive staining for the constitutive (NOSIII) but not for the inducible NO synthase (NOSII). Accordingly, NOSII mRNA levels commenced to increase only at the very end of the LPS perfusion period. Progressive liberation of thromboxane (Tx) A(2) and prostacyclin was induced by LPS together with myocardial cyclooxygenase (Cox)-2 mRNA expression. Both nonselective inhibition of Cox by indomethacin and selective inhibition of the inducible Cox-2 by NS-398 abolished prostanoid release. Interestingly, the generation of TNF-alpha and the associated cardiodepression caused by LPS were reduced by indomethacin, NS-398 and the Tx-receptor antagonist daltroban.

CONCLUSIONS

LPS depresses contractility of isolated rat hearts by inducing TNF-alpha synthesis and subsequently activating the sphingomyelinase pathway, whereas no evidence for a role of NOSII- or NOSIII-generated NO was found. Moreover, Cox-2-derived TxA(2) appears to facilitate TNF-alpha synthesis in response to LPS.

Rifabutin-based triple therapy after failure of Helicobacter pylori eradication treatment: preliminary experience

Despite continuous improvement of Helicobacter pylori (Hp) eradication therapy, new treatment regimens are necessary if established first-line treatments fail. In the present pilot study, a recently described rifabutin-based triple therapy was evaluated after preceding failure of triple therapy. Rifabutin (150 mg), amoxicillin (1 g), and lansoprazole (30 mg) were administered twice daily for 1 week to 25 patients infected with Hp who had previously failed to respond to eradication treatment and/or who had developed resistance to macrolides and nitroimidazoles. Four patients were lost to follow-up. Eradication rate of rifabutin-based triple therapy was 86% (18/21; per protocol) and 72% (18/25; intention-to-treat). Side effects were minimal. It is concluded that this new drug combination is an effective therapy for Hp strains resistant to clarithromycin or metronidazole; however, rifabutin-based treatment regimens for Hp eradication should be restricted to patients infected with resistant strains.

Secondary resistance among 554 isolates of Helicobacter pylori after failure of therapy

In a study to determine secondary resistance among Helicobacter pylori isolates, gastroenterologists from several German cities submitted over a 3-year period to centre A (Regensburg) or centre B (Freiburg) gastric biopsies from patients in whom one or more therapies to eradicate Helicobacter pylori had failed. Rates of resistance among the collections of 302 (centre A) and 252 (centre B) isolates were, respectively, as follows: to metronidazole, 75% and 66%; to clarithromycin, 58% and 49%; to amoxicillin, 0%; to ciprofloxacin, 9%; to doxycycline, 0%; and to rifampin, 0%. Resistance to clarithromycin was associated with metronidazole resistance in 89% and 85% of the isolates in centre A and centre B, respectively.

Mutations at four distinct regions of the rpoB gene can reduce the susceptibility of Helicobacter pylori to rifamycins

The transformation of a panel of rpoB mutations (codons 525 to 586) from rifampin-resistant donor strains into Helicobacter pylori 2802A confirmed the MICs associated with the respective mutations. RpoB V149X random mutations were generated and induced different levels of resistance, depending on the replacement amino acid. Mutagenesis of the rpoB gene at codon position 701 (R701H) induced low-level resistance.

Mutations in the beginning of the rpoB gene can induce resistance to rifamycins in both Helicobacter pylori and Mycobacterium tuberculosis

A clinical isolate of Helicobacter pylori that developed resistance to rifabutin during therapy carried an rpoB gene that retained a wild-type cluster region sequence but had acquired a novel codon 149 (V149F) mutation. In transformation experiments, the mutation was shown to confer high-level rifabutin resistance. The equivalent mutation (V176F) was present in several resistant isolates of Mycobacterium tuberculosis.

Transport and storage of fresh and frozen gastric biopsy specimens for optimal recovery of Helicobacter pylori

The viability of Helicobacter pylori in vitro and in gastric biopsy specimens was determined. Recovery rates were 94, 87, and 77% from biopsy specimens in Portagerm pylori in cooled containers after 1, 2, and 3 days of transport, respectively (n = 307), and 97% if stored and shipped in glycerol broth at -70 degrees C (n = 232).

Rifampin and rifabutin resistance mechanism in Helicobacter pylori

Eighty-one clinical isolates of Helicobacter pylori showed no resistance to rifampin (MIC range, 0.032 to 2 microg/ml; MIC at which 50% of isolates are inhibited [MIC50], 0.25 microg/ml). The MIC50 of rifabutin was 0.008 microg/ml (n = 16). All resistant laboratory mutants of H. pylori ATCC 43504 showed amino acid exchanges in codons 524 to 545 or codon 585 of the rpoB gene, corresponding to the gene sequences from Mycobacterium tuberculosis and Escherichia coli.

Listeria monocytogenes-induced endogenous endophthalmitis in an otherwise healthy

PURPOSE Listeria monocytogenes is a rare cause of endogenous endophthalmitis. To date 15 cases have been published in the literature. All eyes showed similar clinical features and profound visual loss mainly due to delayed diagnosis.

METHODS

An additional case of an otherwise healthy 73 year-old male, who was referred to our hospital because of acute iridocyclitis with secondary glaucoma, is reported. Within a few days the severity of the intraocular infection increased dramatically, resulting in the clinical picture of acute endophthalmitis. RESULTS In contrast to most published cases, early identification of the causative pathogen in the aqueous humor after anterior chamber puncture using polymerase chain reaction (PCR) and the initiation of a specific, systemic antibiotic medication, resulted in complete recovery of visual acuity.

CONCLUSIONS

PCR is very useful for the identification of the pathogen in intraocular infections. (Eur J Ophthalmol 1999; 9: 53-7).

Listeria monocytogenes-induced endogenous endophthalmitis in an otherwise healthy individual: rapid PCR-diagnosis as the basis for effective treatment

PURPOSE

Listeria monocytogenes is a rare cause of endogenous endophthalmitis. To date 15 cases have been published in the literature. All eyes showed similar clinical features and profound visual loss mainly due to delayed diagnosis.

METHODS

An additional case of an otherwise healthy 73 year-old male, who was referred to our hospital because of acute iridocyclitis with secondary glaucoma, is reported. Within a few days the severity of the intraocular infection increased dramatically, resulting in the clinical picture of acute endophthalmitis.

RESULTS

In contrast to most published cases, early identification of the causative pathogen in the aqueous humor after anterior chamber puncture using polymerase chain reaction (PCR) and the initiation of a specific, systemic antibiotic medication, resulted in-complete recovery of visual acuity.

CONCLUSIONS

PCR is very useful for the identification of the pathogen in intraocular infections.

[Surgical worm extraction in loa loa ophthalmia]

BACKGROUND

Loa Loa is a chronic parasitemic disease which is endemic in the tropical rain forests of Western Africa. Vector of this disease is a mangrove fly with the name Chrysops. Besides the eye worm and skin affections a systemic infection with microfilariae is common.

PATIENT

A West African tourist from Bangibe showed up at the university eye clinic. His complaints were a red eye and a mobile subconjunctival tumor (Fig. 1) that showed vermiform movements. The worm was transparent and 4-5 cm in length. After topical anaesthesia and the attempt to paralyze the worm (1) with Pilocarpine 2% it vanished. Two days later the patient showed up in the morning for the planned blood test. No worm was visible at that time but at noontime the blood test was carried out and at that time the worm was visible in the nasal conjunctiva. This time the worm was removed without delay under topical anaesthesia. The worm was fixed with a forceps through the conjunctiva which was opened for 0.5 cm. The worm was grasped with a second forceps and drawn out under massive vermiform movement. Systemic therapy was recommended with Hetrazan (Diethylcarbamazine) using Corticosteroides and Antihistamine to minimize allergic side effects by the therapy due to the systemic microfilariae blood load. Eosinophilia was 8%.

CONCLUSIONS

A subconjuctival Loa Loa worm can be removed under topical anaesthesia by fixing it with a forceps through the conjunctiva and opening it and grasping the worm with a second forceps. According to our experience the paralyzation with Pilocarpine cannot be realized. Careful systemic therapy avoiding reported allergic side effects with Hetrazan which is not available in Germany is necessary.

Eradication of Helicobacter pylori with lansoprazole, roxithromycin and metronidazole--an open pilot study

BACKGROUND

The most extensively studied Helicobacter pylori eradication regimen comprises omeprazole, clarithromycin and metronidazole. Macrolide antibiotics other than clarithromycin should achieve similar efficacy, but they have not yet been thoroughly tested.

AIM

To determine the efficacy and safety of a triple therapy regimen using lansoprazole, roxithromycin, and metronidazole on the basis of multicentre outpatient care in an open pilot study.

METHODS

163 patients with duodenal ulcer and proven H. pylori infection received lansoprazole 30 mg b.d., roxithromycin 300 mg b.d. and metronidazole 500 mg b.d. for 7 days followed by another 7 days of lansoprazole 30 mg once daily. H. pylori status was determined by urease quick test, histology, microbiology and 13C-urea breath test before starting and at least 4 weeks after completing treatment.

RESULTS

150 patients were available for evaluation; H. pylori was successfully eradicated in 84.7% (127/ 150) as determined by urease quick test, 78.0% (117/150) by histology, 81.3% (109/134) by 13C-urea breath test; and in 75.3% (113/150), at least two tests were negative. Side-effects were reported in 34 patients (most commonly diarrhoea and changes in liver function tests), in two cases the study medication was interrupted. Prior to treatment, 23% of the H. pylori isolates were resistant against metronidazole and 3.4% against roxithromycin. After unsuccessful treatment, 84% of the isolates were resistant against metronidazole and 21% against roxithromycin. Primary resistance to metronidazole increased the chance of treatment failure approximately sevenfold (7% vs. 53%).

CONCLUSIONS

For H. pylori eradication, the combination of lansoprazole, roxithromycin and metronidazole proved to be as safe as other current triple therapy regimens, while a comparison of efficacy rates yet remains to be assessed in prospective controlled trials. The metronidazole-resistant H. pylori is not rare in Germany and, in the present study, has strongly influenced treatment success.

[Listeria monocytogenes-induced endogenous endophthalmitis in an otherwise healthy patient: PCR-assisted rapid diagnosis as the basis for successful therapy]

BACKGROUND

Listeria monocytogenes is a rare cause of endogenous endophthalmitis. Only 14 cases are published in the literature so far. All eyes showed similar clinical features and profound visual loss.

PATIENTS AND METHODS

We report on a case of an otherwise healthy 73-year-old male. He was referred to our hospital because of acute hypopyoniritis with secondary glaucoma. Within a few hours the severity of the intraocular infection increased dramatically resulting in the clinical picture of an acute endophthalmitis.

RESULTS AND CONCLUSION

Early identification of the causative pathogen in the aqueous humor after anterior chamber paracenthesis using polymerase chain reaction (PCR) and the initiation of a specific, systemic antibiotic medication resulted in a complete recovery of visual acuity.