Immunosenescence and vaccine efficacy revealed by immunometabolic analysis of SARS-CoV-2-specific cells in multiple sclerosis patients

Disease-modifying therapies (DMT) administered to patients with multiple sclerosis (MS) can influence immune responses to SARS-CoV-2 and vaccine efficacy. However, data on the detailed phenotypic, functional and metabolic characteristics of antigen (Ag)-specific cells following the third dose of mRNA vaccine remain scarce. Here, using flow cytometry and 45-parameter mass cytometry, we broadly investigate the phenotype, function and the single-cell metabolic profile of SARS-CoV-2-specific T and B cells up to 8 months after the third dose of mRNA vaccine in a cohort of 94 patients with MS treated with different DMT, including cladribine, dimethyl fumarate, fingolimod, interferon, natalizumab, teriflunomide, rituximab or ocrelizumab. Almost all patients display functional immune response to SARS-CoV-2. Different metabolic profiles characterize antigen-specific-T and -B cell response in fingolimod- and natalizumab-treated patients, whose immune response differs from all the other MS treatments.

[First data concerning the medical supply of patients with non-alcoholic fatty liver disease in Germany - a survey in university hospital centers of hepatology]

BACKGROUND

Non-alcoholic fatty liver disease (NAFLD) currently is one oft the most common reasons for chronic liver injury in the western world. In the European and American population the prevalence is up to 30 %. The medical supply of German patients with NAFLD is variable and has not been analyzed to date.

METHODS

We sent questionnaires to all university liver centers in Germany (11 questions) concerning the medical supply of patients with NAFLD. Questions included the rate of patients with fatty liver disease in the outpatient clinics, metabolic comorbidities and the kind of assignment. Besides that, individual clinical standards were documented. We compared longitudinal changes between 2008 and 2013.

RESULTS

The return rate of questionnaires was 65 % (n = 20). Analysis showed that the portion of NAFLD patients in the university outpatient clinics had increased between 2008 and 2013 with the predominant part of patients being assigned from external practitioners and not from internal departments of the hospital. Only few patients were assigned by diabetologists or endocrinologists, but on the other hand most liver outpatient clinics investigated their NAFLD patients for metabolic disorders. Cooperation between liver outpatient clinics and other medical services was moderate and was rated average, joint conferences were held rarely. Follow-up visits of patients with NAFLD take place regularly in all centers, however based on different criterions. A consistent algorithm concerning risk assessment and invasive workup does not exist.

CONCLUSION

The awareness concerning patients with NAFLD seems to have grown in recent years. Nevertheless, the medical supply of these patients is quite heterogenous and consistent standards do not exist. Therefore, a common guidline is urgently required.

Arthroscopic-Assisted Intraosseous Balloon-Assisted Repositioning of a Tibial Plateau Fracture: A Case Report

This is the first description of an arthroscopic-assisted intraosseous balloon-assisted repositioning and defect filling of a tibial plateau fracture. The bone defect was filled with calcium phosphate cement in a liquid/paste form. The described technique was therefore introduced in order to allow an arthroscopic control of reposition and intra-articular cement escape during defect filling. X-rays showed an exact reposition without cement escape and the clinical outcome was satisfactory.

[Patient with COPD after allogeneic hematopoietic stem cell transplantation with cough and subfebrile temperature]

HISTORY AND ADMISSION FINDINGS

A 53-year-old male presents with progressive cough and subfebrile temperatures with a history of COPD and post one-year allogeneic hematopoietic stem cell transplantation.

EXAMINATIONS

No pathogenic agent was identified in virological and microbiological diagnostic testings of sputum. At bronchoscopy a half peanut was retrieved from the right main bronchus.

TREATMENT AND COURSE

After recovery of the peanut the patient's symptoms immediately improved.

CONCLUSIONS

Even in adults, with high risk of infectious pneumonia a foreign body aspiration should be considered if pulmonary symptoms worsen.

Two-year clinical experience with the CyPass micro-stent: safety and surgical outcomes of a novel supraciliary micro-stent

PURPOSE

The aim of this study was to evaluate through 2 postoperative years the clinical outcomes associated with a novel supraciliary micro-stent for the surgical treatment of open-angle glaucoma (OAG) when implanted in conjunction with cataract surgery.

PATIENTS AND METHOD

In a multicenter, prospective, consecutive case series, 136 subjects (136 eyes) with OAG and requiring cataract surgery with 24-month postoperative data were included. A combined phacoemulsification procedure, with intraocular lens insertion and CyPass Micro-Stent implantation into the supraciliary space of the study eye, was performed. At baseline, all subjects were on glaucoma medication with either uncontrolled intraocular pressure (IOP; ≥ 21 mmHg, Cohort 1, n=51) or controlled IOP (<21 mmHg, Cohort 2, n=85). Glaucoma medications were stopped postoperatively, but could be restarted if needed, at the investigator's discretion. Device-related adverse events, postoperative IOP, best corrected distance visual acuity (BCDVA), and number of IOP-lowering medications were recorded.

RESULTS

The micro-stent was successfully implanted in all eyes. At 24 months, 82 subjects remained in the study. No sight-threatening adverse events occurred. The most common adverse events were transient hypotony (15.4%) and micro-stent obstruction (8.8%), typically due to iris tissue overgrowth. Fifteen subjects (11%) required secondary incisional glaucoma surgery. For Cohort 1 (n=23), mean ± SD IOP was 15.8 ± 3.8 mmHg after 24 months (change, -37% ± 19%). Mean IOP decrease from baseline was statistically significant (p<0.0001) at months 6, 12, and 24. For Cohort 2 (n=59), mean ± SD IOP at 24 months was 16.1 ± 3.2 mmHg (change, 0% ± 28%). Mean decrease from baseline was statistically significant at months 6 (p=0.0188) and 12 (p=0.0356). At 24 months, the mean ± SD number of medications was 1.0 ± 1.1 in Cohort 1 and 1.1 ± 1.1 in Cohort 2. Mean decrease from baseline medication use was statistically significant at months 6 (p<0.001), 12 (p<0.001), and 24 (p=0.0265) in Cohort 1, and at months 6, 12, and 24 (all p<0.0001) in Cohort 2.

CONCLUSIONS

CyPass Micro-Stent implantation, in combination with cataract surgery, was associated with minimal complications while substantially lowering IOP and/or use of IOP-lowering medications.

[Arterial hypertension: guideline acceptance and implementation in workaday life of internists and general practitioners in Thuringia]

BACKGROUND AND OBJECTIVE

Although evidence-based medical guidelines are widely accepted it is not clear how they are implemented in daily clinical work. The aim of this study was a Thuringia-wide analysis of hypertension diagnosis and treatment in clinical practice of internists and general practitioners, combined with the evaluation of guideline implementation.

METHODS

1884 Thuringian internists and general practitioners were interviewed using a postally delivered, validated questionnaire to assess knowledge and implementation of the hypertension guidelines.

RESULTS

33,4 % of the physicians participated in our survey (433 general practitioners, 197 internists). 98 % of the participants routinely treat hypertension. Internists reported significantly more frequently to treat patients with resistance to antihypertensive therapy. Compared with older physicians and general practitioners, internists were significantly more likely to initiate diagnostic procedures for secondary hypertension according to the guidelines. Long-term measurement of arterial blood pressure in patients with more than three antihypertensive drugs and in cases of suspected endorgan damage or sleep apnea syndrome was more frequently applied by internists. 82,1 % of the participants reported to prescribe nonpharmacological therapies because of their efficacy. ACE-inhibitors (41,6 %) and beta-blockers (34,6 %) were preferred for monotherapy of hypertension without risk factors. ACE-inhibitors (80,1 %), followed by angiotensin receptor antagonists (12,1 %), were primarily selected in hypertensive patients with diabetic nephropathy. In left-ventricular hypertrophy, ACE inhibitors were favoured, too (67%).

CONCLUSION

This survey indicates that in clinical practice doctors treat hypertensives according to official guidelines. However, there is a need for further education especially regarding indication of long-term measurement of arterial blood pressure. Continued education related to diagnosis and treatment of arterial hypertension and implementation of guidelines remains a permanent challenge for doctors.

Argatroban for elective percutaneous coronary intervention: the ARG-E04 multi-center study

The synthetic arginine-derived direct thrombin inhibitor argatroban is an attractive anticoagulant for percutaneous coronary intervention (PCI), because of its rapid onset and offset, and its hepatic elimination. Argatroban was approved for PCI in patients with heparin-induced thrombocytopenia (HIT). However, there are limited data about argatroban in non-HIT patients. The objective of this open-label, multiple-dose, controlled study was to examine the safety and efficacy of argatroban in patients undergoing elective PCI.

METHODS AND RESULTS

Of 140 patients randomized to three argatroban dose groups (ARG250, ARG300, and ARG350 with 250, 300, or 350 μg/kg bolus, followed by 15, 20, or 25 μg/kg/min infusion) and one unfractionated heparin (UFH) group (70-100 IU/kg bolus), 138 patients were analyzed. Argatroban dose-dependently prolonged activated clotting time (ACT) with more patients reaching the minimum target ACT after the initial bolus injection (ARG250: 86.1%, ARG300: 89.5%, and ARG350: 96.8%) compared to 45.5% in UFH (p<0.001). The patient proportion who did not require additional bolus injections to start PCI was significantly higher in argatroban than in UFH (p ≤ 0.002). Consequently, the time to start of PCI was shortened in argatroban groups. Composite incidences of death, myocardial infarction, and urgent revascularization until day 30 were not significantly different between the groups (ARG250: 2.8%, ARG300: 0.0%, ARG350: 3.2% vs. UFH: 3.0%). Major bleeding was observed only in UFH (3.0%), while minor bleeding occurred in ARG350 (3.2%) and UFH (6.1%, n.s.).

CONCLUSION

Argatroban dose-dependently increases coagulation parameters and, compared to UFH, demonstrates a superior predictable anticoagulant effect in patients undergoing elective PCI.

Release pattern of N-terminal pro B-type natriuretic peptide (NT-proBNP) in acute coronary syndromes

BACKGROUND

Recently it has been found that BNP and NT-proBNP provide independent prognostic information in patients with acute coronary syndromes (ACS). However, little data are available on the time course of NT-proBNP levels in relation to onset of symptoms.

METHODS AND RESULTS

We included 765 patients (236 females, aged 64 +/- 11 years) with an ACS (STEMI 42%, NSTEMI 41%, UAP 17%), who were referred for coronary angiography. NT-proBNP was assessed on admission and the next day. NT-proBNP values were related to the time duration from onset of symptoms until blood drawing with lowest values within 3 h and highest values 24-36 h after onset of symptoms (147 (64-436) pg/ml and 1099 (293-3795) pg/ml, respectively, p < 0.001). Highest values for NT-proBNP on admission were found in patients with NSTEMI compared to patients with STEMI and UAP (912 (310-2258) pg/ml) vs 262 (85-1282) pg/ml) vs 182 (74- 410) pg/ml; p < 0.001), but no difference was present between STEMI and NSTEMI the day after admission (1325 (532-2974) pg/ ml vs 1169 (555-3413) pg/ml; p = 0.676). In contrast NT-proBNP values remained unchanged in UAP (182 (74-410) pg/ml) vs 171 (53-474) pg/ml).

CONCLUSION

The time interval from onset of symptoms to first blood collection is an important determinant for NT-proBNP values on admission in patients with an ACS and needs to be considered in clinical practice.

Treatment of in-stent restenosis with sirolimus-eluting-stents—

Treatment of in-stent restenosis (ISR) remains a therapeutic challenge since many pharmacological and mechanical approaches have shown disappointing results except for brachytherapy. Drug-eluting stents (DES) have been reported to effectively reduce ISR in de novo lesions. We studied 55 consecutive patients with ISR in native coronary arteries and 7 with ISR in saphenous vein grafts (SVG) with elective indication for percutaneous coronary intervention (PCI), who underwent successful implantation with DES. No in-hospital postprocedural major adverse cardiac events were observed. All but one patient (n=61) underwent an angiographic follow-up at 183+/-30 days. Grade of stenosis was assessed by quantitative coronary angiography (QCA) at index procedure and at control angiography. Restenosis (>50%) occurred in 5 patients (8.2%). Target vessel revascularization was performed in an additional 4 patients. Minimal intimal hyperplasia was observed in all segments covered by DES (late loss 0.08+/-0.37 mm, loss index 0.11+/-0.47). One patient suffered from subacute stent thrombosis due to discontinuation of clopidogrel medication. At six month follow-up two patients had died. Death was not related to a restenosis in the treated segment. Conclusion Our experiences with DES treatment of ISR lesions show good angiographic and clinical results at index procedure and at the 6 month follow-up with low sub acute thrombosis rate as compared with existing treatment modalities. Restenosis rate seems to be at least as low as reported for brachytherapy.

Transcatheter closure of a ruptured ventricular septum after myocardial infarction using a venous approach

A 65-year old patient was admitted after having sustained a ventricular septum rupture 18 days after an anterior myocardial infarction. He developed acute heart failure. Given the extremely high perioperative risk in surgical approaches in this setting, we decided for a transcatheter closure of the defect with an exclusively venous approach. After a complete recovery, the patient underwent open heart surgery with aorto coronary bypass, aneurysmectomy, and removal of the closure device. This case demonstrates that transcatheter closure of a post infarction ventricular septum rupture is a technically feasible and suitable method.

[Cardiopulmonary exercise capacity increases after interventional ASD-closure]

BACKGROUND

In patients with atrial septal defects of the secundum-type (ASD), exercise tolerance is reduced. Generally, ASD closure is recommended in symptomatic patients and in patients with a relevant left-to-right shunt (Qp/Qs > 1.5). Only few data are available concerning objective parameters of cardiopulmonary exercise capacity. The aim of this study was to evaluate exercise capacity as achieved by ergospirometry in adult patients with an ASD at baseline and in the long-term following transcatheter closure.

METHODS AND RESULTS

Thirty consecutive patients (8 male; mean age 43.4 years; defect size 23.5 mm; pulmonary-to-systemic flow ratio (Qp/Qs) 1.94) performed exercise testing on a supine bicycle ergometer. At baseline, oxygen consumption at maximal exercise (VO(2) peak) was 14.3 ml/min kg, oxygen consumption at the anaerobic threshold (VO(2)-AT) was 11.2 ml/min/kg and maximal achieved workload was 86 Watt. At one and six months after ASD-closure, there was no relevant increase of the VO(2) peak, the VO(2)-AT or the maximal workload. After 12 months, there was a significant increase of the VO(2) peak (15.1 ml/min/kg, p = 0.049), the VO(2)-AT (13 ml/min/kg, p < 0.001) and the maximal workload (99 Watt, p < 0.01). An increase of the oxygen consumption at the anaerobic threshold (Delta VO(2) AT) could be seen in 24 out of 30 patients and was independent of shunt volume (Q(p)/Q(s) < or = 2, 1.95 ml/ min/kg; Q(p)/Q(s) > 2, 2.13 ml/min/ kg; ns), defect size (defect < or = 24 mm, 2.0 ml/min/kg; defect > 24 mm, 1.5 ml/min/kg; ns), age (age < or = 44 years, 1.97 ml/min/kg; age >44 years, 1.66 ml/min/kg; ns), gender (female 1.56 ml/min/ kg; male 1.91 ml/min/kg; ns) and of the existence of a residual shunt. Highly symptomatic patients had a tendency to have greater benefit from ASD-closure as compared to mildly symptomatic patients (NYHA 0/I 1.85 ml/min/kg; NYHA II 1.5 ml/min/ kg; NYHA III 2.7 ml/min/kg; ns). There was no correlation between shunt volume, shunt size, pulmonal arterial pressure and increase of the oxygen consumption at the anaerobic threshold (Delta VO(2) AT).

CONCLUSION

There is no relevant improvement in exercise capacity early (1-6 months) after interventional ASD-closure, but late after ASD-closure (12 months) exercise capacity improves significantly. This improvement can be found in almost all patients independent of gender, age, symptoms, shunt volume and defect size.

[Nonoperative treatment of ischemic contractures of forearm and hand]

The acute compartment syndrome of the forearm and hand leads to severe muscle necrosis and nerve damage if the diagnosis is not recognized. The resulting ischemic contractures and paralyses require a distinctive regime of therapy. Therefore,physiotherapy and occupational therapy are of main importance. In mild cases exclusively nonoperative treatment is possible. The goal is to exercise the function of the remaining muscles, mobilize the joints, and stretch muscle scars. Severe forms need surgery. To reach the best starting point for the operation, extensive preoperative active and passive exercises as well as splint therapy are required. Postoperatively, this regime has to be continued to retain a favorable outcome. The treatment approach is demonstrated with a case report.

[Standardised operation technique for ulna-shortening with a new sliding-hole plate]

Ulna-shortening is a widely accepted procedure for the treatment of ulna-impaction syndrome. High rates of non-unions however necessitate improving the operation technique. The new device introduced in this study is a 7-hole plate in which two proximal holes are sliding-holes. By correct placement of two distal screws and two screws in the sliding-holes, rotational stability is guaranteed. The osteotomy is performed while the plate is loosely fixed to the ulna. After fixation of the two distal screws, the sliding-holes facilitate reposition with a good closure of the osteotomy gap. Excentric placement of two more screws and placement of a lag screw across the oblique osteotomy leads to further compression at the osteotomy site. Ulna-variance can be adjusted exactly. So far the plate has been implanted in 15 patients. Ulna-variance was reduced from + 2 to - 2.2 mm. The clinical results are comparable to those of ulna-shortenings in the literature. The sliding-hole plate allows an exact connection with good closure of the osteotomy without malrotation. With this simplified technique, the risk of non-union can be reduced.

Treatment of aortocoronary vein graft lesions with membrane-covered stents: A multicenter surveillance trial

BACKGROUND

Stent implantation in lesions of degenerated aortocoronary vein grafts is associated with a high risk of periprocedural thrombus embolization and in-stent restenosis.

METHODS AND RESULTS

In a multicenter study, we followed up 109 consecutive patients (mean age 66+/-8 years, 12% female) who received polytetrafluoroethylene (PTFE) membrane-covered stents for 125 de novo stenoses in vein grafts 11+/-5 years after bypass surgery. Stent deployment was successful in all but 1 patient; 1 patient suffered from subacute stent thrombosis. Six-month cardiac mortality was 7% (8 patients), 3 patients (3%) underwent repeat bypass surgery, and 9 patients (8%) required target-lesion PTCA. Repeat angiography revealed vessel occlusions in 9% and in-stent restenosis in 8% of patients by the end of follow-up.

CONCLUSIONS

Membrane-covered stents appear to be a safe and efficient treatment strategy associated with a low incidence of restenosis and target-vessel revascularization. Compared with previous studies, the investigated device is not associated with an increase in mortality or late vessel occlusions.

In vitro effects of interleukin-10, prednisolone, and GM-CSF on the non-specific immune function of human polymorphonuclear leucocytes and monocytes

A wide range of immune-modulating effects make IL-10 a potential therapeutic option in the treatment of numerous diseases pathophysiological based on a dysregulation of cytokine production. The background of this study was to investigate, whether the beneficial effects of a therapeutic immunosuppression with IL-10 may be countered by an increased risk for infections due to impaired effector cell functions of unspecific immunity. We demonstrated the in vitro effects of IL-10 on phagocytosis (P), intracellular killing (K), and chemotactic activity (C) by human neutrophils (PMN) and monocytes (MON) using Candida albicans as test strain and compared the results to the effects of prednisolone and GM-CSF. IL-10 reduced significantly the intracellular killing rate of PMN compared to untreated phagocytes (60 +/- 16% versus 68 +/- 13%, mean +/- SD, p = 0.0002). High dose IL-10 (100 ng/ml) had a stimulating effect on the percentage of phagocytizing MON (70.2 +/- 12.7% vs. 66.9 +/- 14.2%, p = 0.0436), without impairing intracellular killing. Prednisolone reduced significantly the Candida uptake by MON (57 +/- 18.1% vs. 66. 9 +/- 14.2%, p = 0.0019). In contrast to prednisolone, neither MON nor PMN chemotaxis was suppressed by IL-10. In conclusion, IL-10 had only marginal immunosuppressive effects on the unspecific immunity compared to prednisolone.

[Abdominal compartment syndrome: prevention and treatment]

Abdominal compartment syndrome is defined by increased intraabdominal pressure above 20 mmHg with increased pulmonary peak pressure and oliguria. In primary abdominal compartment syndrome the increased intraabdominal pressure is caused directly by peritonitis, ileus or abdominal and pelvic trauma. Secondary compartment syndrome is a result of forced closure of the abdominal wall after abdominal surgery. The effects are decreased cardiac output, pulmonary atelectasis, oliguria to anuria and hepatic as well as intestinal reduction of perfusion. Effective monitoring is done by standardised measuring of urinary bladder pressure. Normal values are between 0 and 7 cm H2O, after elective laparotomies 5-12 cm H(2)0. Above 25 cm H(2)0 they are definitely pathological. For the prevention and therapy of manifested abdominal compartment syndrome the application of a laparostomy using a resorbable mesh is recommended. Between 1988 and 1999 we applied a laparostomy to lower the intraabdominal pressure in 377 patients. In 16% of the cases it was indicated by primary abdominal compartment syndrome with a bladder pressure of 31 +/- 4 cm H(2)0 preoperatively, which could be lowered to 17 +/- 4 cm H(2)0 by laparostomy. An early reconstruction of the abdominal wall could be performed in 18% of the cases.

CONCLUSIONS

The abdominal compartment syndrome is an often underestimated problem in abdominal surgery involving multiple organ systems. The temporary laparostomy lowering intraabdominal pressure rather than a forced closure of the abdominal wall should be used in all circumstances.

[Surgical treatment of high anorectal and rectovaginal fistulas with the use of transanal endorectal advancement flaps]

INTRODUCTION

Sphincterotomy can be avoided in the repair of high anorectal or rectovaginal fistulas by use of rectal advancement flaps.

METHODS

Between 1986 and 1998, 22 patients with high anorectal and 15 patients with rectovaginal fistulas underwent fistulectomy without sphincterotomy and consecutive transanal rectal advancement flap repair.

RESULTS

Primary healing was achieved in 81% (30/37 patients). There was no disturbance of continence though anal resting pressures decreased postoperatively. Recurrences occurred in 4 of 12 patients with Crohn's disease (2 anorectal, 2 rectovaginal) and in 1 patient with traumatic anorectal fistula. There were no recurrences in patients with cryptoglandular disease, while the operation failed in 2 patients with ergotamine-induced fistulas.

CONCLUSIONS

This operative approach achieves a high primary healing rate with optimal functional outcome. Despite good results the indication should be set carefully in patients with Crohn's disease.

Pharmacokinetics of gatifloxacin and interaction with an antacid containing aluminum and magnesium

The pharmacokinetics of gatifloxacin (400 mg orally) and the influence of the antacid aluminum magnesium hydroxide (20 ml of Maalox 70) on the bioavailability of gatifloxacin in 24 healthy volunteers were assessed. In an open, randomized, six-period crossover study, the volunteers received either gatifloxacin alone (treatments A and D); aluminum magnesium hydroxide concomitant with gatifloxacin (treatment C); or aluminum magnesium hydroxide 2 h before (treatment B), 2 h after (treatment E), or 4 h after gatifloxacin administration (treatment F). Gatifloxacin concentrations were measured by a validated bioassay and high-performance liquid chromatography. Pharmacokinetics of a single 400-mg dose of gatifloxacin alone were characterized as follows (mean +/- standard deviation): peak concentration (Cmax), 3.8 +/- 0. 5 (treatment A) and 3.4 +/- 0.9 (treatment D) microgram/ml; time to Cmax, 1.4 +/- 0.8 (treatment A) and 1.7 +/- 0.7 (treatment D) h; area under the curve from time zero to infinity (AUC0-infinity), 33. 5 +/- 5.9 (treatment A) and 31.4 +/- 3.4 (treatment D) microgram. h/ml; urine recovery, (83 +/- 6)% (treatment A) and (84 +/- 8)% (treatment D). Comparison of the results obtained by bioassay showed a good correlation. Aluminum magnesium hydroxide administration 2 h before (treatment B) or concomitant with (treatment C) gatifloxacin decreased the Cmax by 45% (2.1 +/- 1.2 microgram/ml) or even 68% (1.2 +/- 0.4 microgram/ml) highly significantly (P < 0.01). AUC0-infinity was significantly reduced from 33.5 +/- 5.9 to 19.4 +/- 6.9 microgram. h/ml (by 42%) or even to 11.9 +/- 3.3 microgram. h/ml (by 64%) (P < 0. 01). If aluminum magnesium hydroxide was given 2 h after gatifloxacin (treatment E), there was no significant reduction of concentration in serum but AUC0-infinity was significantly reduced from 31.4 +/- 3.4 to 25.9 +/- 5.3 microgram. h/ml (18%) (P < 0.01). Aluminum magnesium hydroxide given 4 h after gatifloxacin (treatment F) showed no influence on the gatifloxacin pharmacokinetics. Therefore, the optimal time between gatifloxacin application and the intake of an aluminum-containing antacid should be 4 h.

VIRTLAB: a virtual molecular biology laboratory

SUMMARY

VIRTLAB is a self-training program based on PBL (Problem-Based-Learning Pathway) built to simulate a molecular biology laboratory. It has been designed to stimulate students in the biological sciences to analyse and solve molecular biology problems using standard laboratory techniques (e.g. restriction enzyme digestions, analytical and preparative agarose gels, DNA cloning and sequencing, etc.) and can thus be viewed as a teaching aid.

AVAILABILITY

The VIRTLAB package is distributed free of charge to non-profit organisations by the authors (virtlab@biol.dgbm. unina.it). On-line help and tutorials, available now in English, French, Italian, and shortly in German, are provided with the software or at http://biol.dgbm.unina.it:8080/virtlab.html++ +

Angiotensin II type 1 receptor A1166C gene polymorphism. Absence of an association with the risk of coronary artery disease and myocardial infarction and of a synergistic effect with angiotensin-converting enzyme gene polymorphism on the risk of these diseases

AIM

There is evidence that interaction between angiotensin II type 1 receptor A1166C gene polymorphism and angiotensin I-converting enzyme Insertion/Deletion gene variation might have an effect on the risk of myocardial infarction. The study was carried out in a population of 2244 male Caucasians, whose coronary anatomy was defined by means of coronary angiography. We analysed the relationship, on the risk of ischaemic heart disease, of angiotensin II type 1 receptor A1166C gene variation, not only to myocardial infarction but also to coronary artery disease, and its potential interaction with angiotensin I-converting enzyme Insertion/Deletion gene polymorphism.

METHODS AND RESULTS

No association was detected between angiotensin II type 1 receptor A1166C gene polymorphism and coronary artery disease. Similarly, there was no link to myocardial infarction, either in the total population or in low risk groups. In addition, most importantly, we found no interaction between angiotensin II type 1 receptor A1166C gene variation and angiotensin I-converting Insertion/Deletion polymorphism, either in connection with the risk of coronary artery disease or myocardial infarction.

CONCLUSION

This angiotensin II type 1 receptor A1166C gene variation is not associated with any detectable increase in risk of ischaemic heart disease. The findings of the present study do not suggest that, as regards risk of coronary artery disease and myocardial infarction, there is interaction between gene polymorphism and angiotensin I-converting enzyme Insertion/Deletion gene variation.

The yeast Ty3 retrotransposon contains a 5'-3' bipartite primer-binding site and encodes nucleocapsid protein NCp9 functionally homologous to HIV-1 NCp7

Retroviruses, including HIV-1 and the distantly related yeast retroelement Ty3, all encode a nucleoprotein required for virion structure and replication. During an in vitro comparison of HIV-1 and Ty3 nucleoprotein function in RNA dimerization and cDNA synthesis, we discovered a bipartite primer-binding site (PBS) for Ty3 composed of sequences located at opposite ends of the genome. Ty3 cDNA synthesis requires the 3' PBS for primer tRNAiMet annealing to the genomic RNA, and the 5' PBS, in cis or in trans, as the reverse transcription start site. Ty3 RNA alone is unable to dimerize, but formation of dimeric tRNAiMet bound to the PBS was found to direct dimerization of Ty3 RNA-tRNAiMet. Interestingly, HIV-1 nucleocapsid protein NCp7 and Ty3 NCp9 were interchangeable using HIV-1 and Ty3 RNA template-primer systems. Our findings impact on the understanding of non-canonical reverse transcription as well as on the use of Ty3 systems to screen for anti-NCp7 drugs.

Association of the platelet glycoprotein IIIa PlA1/A2 gene polymorphism to coronary artery disease but not to nonfatal myocardial infarction in low risk patients

BACKGROUND

The platelet membrane glycoprotein IIb/IIIa functions as a receptor for fibrinogen and von Willebrand factor during platelet aggregation. In a small case-control study, evidence has been presented that the PlA2 allele of the platelet glycoprotein GPIIIa PlA/A2 gene polymorphism might be an independent risk factor for acute myocardial infarction (MI).

METHODS AND RESULTS

We explored the association of the PlA1A2 to the severity of coronary artery disease (CAD), as assessed angiographically in 2252 male individuals, and to myocardial infarction (MI). The severity of coronary heart disease (CHD) was also estimated by calculating a CHD score according to Gensini. The PlA genotype was determined by allele specific restriction digestion. Relation of the PlA2 allele to CAD: In the total population, the frequency of the PlA2 allele was not associated to the presence or to the extent of CAD. Also the CHD scores of PlA1/PlA2 genotypes were essentially the same. However, after exclusion of individuals with high BMI (> or =26.9 kg/m2) and/or low apoAI (< 1.43 g/l) PlA2PlA2 carriers had clearly higher CHD scores than PlA1PlA1 genotypes: PlA1PlA2 heterozygotes had intermediate values (p <0.05). After division of the study population into one group of individuals without any angiographic signs of CAD (CHD score = 0) and into another group of patients with severe CAD (CHD score (> or = 120), a strong association of the PlA2 allele with severe CAD was also found in the same low risk groups: e.g. exclusion of persons with high BMI and low apoAI resulted in an Odds ratio of 5.37 (1.46-19.7) (p <0.02). Relation of the PlA2 allele to MI: No association was found between PlA1/PlA2 genotypes and risk of MI neither in the total population nor in low risk subgroups.

CONCLUSIONS

Whereas no difference in the distribution of allele and genotype frequencies between controls and survivors of MI could be detected, the PlA2 allele is associated with CHD in low risk patients.

ACE I/D gene polymorphism: presence of the ACE D allele increases the risk of coronary artery disease in younger individuals

BACKGROUND

Presence of the D allele or homozygosity for the deletion (D) allele of the ACE insertion/deletion (I/D) polymorphism has been discussed as potent risk factor for coronary artery disease (CAD) and myocardial infarction (MI).

METHODS AND RESULTS

In 2267 male Caucasians the relation of the ACE I/D gene polymorphism to CAD and MI were investigated. An association of the D allele to CAD was detected in younger subjects (e.g. < 61.7 years, mean value), but not in older patients (e.g. > or = 61.7 years). Additional exclusion of individuals with other cardiovascular risk factors (e.g. high BMI) produced an even stronger association of the D allele to CAD. In contrast, a relation of this polymorphism to non-fatal MI was only observed in older subjects; additional limitation to individuals without cardiovascular risk factors (e.g. BMI and/or diabetes) yielded a further enhancement of this association to MI. In younger subjects (e.g. < 61.7 years) the gene polymorphism was not related to non-fatal MI even after exclusion of additional risk factors.

CONCLUSIONS

The present large case-control study strengthens the assumption of an association of the ACE D allele with the risk of ischemic heart disease.

Comparative pharmacokinetics of dirithromycin and erythromycin in normal volunteers with special regard to accumulation in polymorphonuclear leukocytes and in saliva

OBJECTIVE

In a randomized cross-over study, we assessed pharmacokinetics and intracellular concentrations in polymorphonuclear leukocytes (PMN) and saliva of erythromycin and erythromycylamine, the active metabolite of dirithromycin.

METHODS

Ten healthy volunteers received 1 g erythromycin b.i.d. or 500 mg dirithromycin qd for 5 days (wash out period, 35 days). Concentrations of erythromycin and erythromycylamine were measured in serum, urine, saliva, and granulocytes by bioassay and high-performance liquid chromatography (HPLC) on days 1, 3, and 5 of each study period, respectively.

RESULTS

While maximal serum concentrations (Cmax) and the area under the data (AUDtot) of erythromycin were significantly higher (Cmax 1.44 mg.l-1, AUDtot 5.66 mg.h.l-1) than those of erythromycylamine (Cmax 0.29 mg.l-1, AUDtot 1.96 mg.h.l-1), erythromycylamine had a significantly higher mean residence time (21 h) than erythromycin (5.5 h). Erythromycylamine accumulated significantly more in PMN than erythromycin; the accumulation factor of erythromycylamine was 100 with a maximal intracellular concentration of 13.4 mg.l-1, whereas the maximal accumulation factor of erythromycin was 4 with a maximal intracellular concentration of 6.1 mg.l-1. There were no significant differences in maximal saliva concentrations (erythromycin 0.35 mg.l-1, erythromycylamine 0.31 mg.l-1).

Pharmacokinetics of sparfloxacin and interaction with cisapride and sucralfate

In an open, randomized, triple crossover study, the effects of cisapride and sucralfate on the pharmacokinetics of sparfloxacin were assessed. Fifteen healthy volunteers received 400 mg of sparfloxacin as a single oral dose on day 0. In a random order, concomitant doses of 10 mg of cisapride three times daily from day -2 to day 2 and 1 g of sucralfate four times daily from day -2 to day 0 were administered. Sparfloxacin concentrations were measured by bioassay and high-performance liquid chromatography. Pharmacokinetic parameters for sparfloxacin alone were as follows (mean +/- standard deviation): maximum concentration of drug in serum (C(max)), 1.27 +/- 0.39 microg/ml; time to C(max) (T(max)), 4.1 +/- 1.9 h; area under the concentration-time curve (AUC), 35.0 +/- 9.7 microg x h/ml; mean residence time, 28.5 +/- 5.7 h; half-life (t1/2), 20 +/- 4 h; urinary recovery (UR x f), 11.0% +/- 2.7%; and metabolite-sparfloxacin ratio in urine, 2.6. For the cisapride group there was a significant decrease in the sparfloxacin T(max) (1.9 +/- 2.1 h) and a significant increase in C(max) (1.74 +/- 0.73 microg/ml). The QTc interval for patients receiving sparfloxacin and cisapride was prolonged by 7.7% compared to the QTc interval during medication-free periods. Significant differences in the values for the group receiving sucralfate compared to the values for the group receiving sparfloxacin alone were found: C(max), 0.77 +/- 0.31 microg/ml; AUC, 18.6 +/- 5.8 microg x h/ml; t1/2, 26 +/- 10 h; and UR x f, 5.8 +/- 1.8%. Concomitant adminstration of cisapride accelerates the absorption and increases the peak concentration of sparfloxacin without having a significant effect on the extent of bioavailability. Coadministration of sucralfate leads to a 44% decrease in the bioavailability of sparfloxacin.

Possible roles of HIV-1 nucleocapsid protein in the specificity of proviral DNA synthesis and in its variability

Retroviral nucleocapsid (NC) protein is an integral part of the virion nucleocapsid where it coats the dimeric RNA genome. Due to its nucleic acid binding and annealing activities, NC protein directs the annealing of the tRNA primer to the primer binding site and greatly facilitates minus strand DNA elongation and transfer while protecting the nucleic acids against nuclease degradation. To understand the role of NCp7 in viral DNA synthesis, we examined the influence of NCp7 on self-primed versus primer-specific reverse transcription. The results show that HIV-1 NCp7 can extensively inhibit self-primed reverse transcription of viral and cellular RNAs while promoting primer-specific synthesis of proviral DNA. The role of NCp7 vis-a-vis the presence of mutations in the viral DNA during minus strand elongation was examined. NCp7 maximized the annealing between a cDNA(-) primer containing one to five consecutive errors and an RNA representing the 3' end of the genome. The ability of reverse transcriptase (RT) in the presence of NCp7 to subsequently extend the mutated primers depended upon the position of the mismatch within the primer:template complex. When the mutations were at the polymerisation site, primer extension by RT in the presence of NCp7 was very high, about 40% for one mismatch and 3% for five consecutive mismatches. Mutations within the DNA primer or at its 5' end had little effect on the extension of viral DNA by RT. Taken together these results indicate that NCp7 plays major roles in proviral DNA synthesis within the virion core due to its ability to promote prime-specific proviral DNA synthesis while concurrently inhibiting non-specific reverse transcription of viral and cellular RNAs. Moreover, the observation that NCp7 enhances the incorporation of mutations during minus strand DNA elongation favours the notion that NCp7 is a factor contributing to the high mutation rate of HIV-1.

The proteolytic cleavage of eukaryotic initiation factor (eIF) 4G is prevented by eIF4E binding protein (PHAS-I; 4E-BP1) in the reticulocyte lysate

A common feature of viral infection is the subversion of the host cell machinery towards the preferential translation of viral products. In some instances, this is partly mediated by the expression of virally encoded proteases which lead to the cleavage of initiation factor eIF4G. The foot-and-mouth disease virus encodes two forms of a cysteine proteinase (L protease) which bisects the eIF4G polypeptide into an N-terminal fragment containing the eIF4E binding site, and a C-terminal fragment which contains binding sites for eIF4A and eIF3 and which associates with the 40S ribosomal subunit. Previously, we have demonstrated that the cleavage of eIF4G by L protease stimulates the translation of uncapped transcripts encoding cellular proteins and supports internal initiation driven by picornavirus internal ribosome entry segment (IRES) elements. Use of reticulocyte lysates manipulated to deplete them of eIF4E and the N-terminal fragment suggests that the C-terminal fragment of eIF4G is responsible for these effects, and we have now confirmed this by purifying the C-terminal fragment and analysing its effects directly in the absence of L protease. Interestingly, we find that pre-incubation of reticulocyte lysates or ribosomal salt wash fractions with the specific eIF4E binding protein, PHAS-I (eIF4E-BP1), blocks the proteolytic cleavage of eIF4G by L protease. This effect can be reversed by addition of recombinant eIF4E. These data are consistent with a model whereby the L protease cleavage site in eIF4G is inaccessible until a change in conformation is induced by the binding of eIF4E. This may have implications for a role for eIF4E binding in triggering changes that expose other domains in the eIF4G molecule during initiation of translation.

A reevaluation of the cap-binding protein, eIF4E, as a rate-limiting factor for initiation of translation in reticulocyte lysate

The cap-binding eukaryotic initiation factor, eIF4E, is a key target for the regulation of translation in mammalian cells and is widely thought to be present at very low molar concentrations. Here we present observations with the reticulocyte lysate that challenge this view. When reticulocyte ribosomes are harvested by centrifugation, most (approximately 75%) of the eIF4E remains in the postribosomal supernatant (PRS). In a reconstituted translation system we find that the ribosome-associated eIF4E alone can sustain much of the overall activity, suggesting that much of the factor in the PRS is functionally redundant. Consistent with this, our estimates of eIF4E in the reticulocyte lysate reveal much higher concentrations than previously reported. The association of a small proportion of eIF4E with the ribosome fraction appears to be functional and dependent on interaction with the factor eIF4G. This fraction of eIF4E is, as expected, more highly phosphorylated than that in the PRS; however, at least half the total phosphorylated eIF4E in reticulocyte lysate translation systems resides in the PRS fraction, suggesting that, while phosphorylation may enhance activity, it is not in itself sufficient to promote utilization of the factor. We also show that the eIF4E-binding factor, eIF4E-BP1 or PHAS-I, which regulates eIF4E activity in insulin-responsive cells, is present in the reticulocyte PRS at an approximately 1:1 molar ratio relative to eIF4E and demonstrate by co-immunoprecipitation studies that the binding of PHAS-I and eIF4G to eIF4E is mutually exclusive. These data are consistent with a potential regulatory role for PHAS-I in the reticulocyte lysate.

The C-terminal domain of eukaryotic protein synthesis initiation factor (eIF) 4G is sufficient to support cap-independent translation in the absence of eIF4E

The foot and mouth disease virus, a picornavirus, encodes two forms of a cysteine proteinase (leader or L protease) that bisects the EIF4G polypeptide of the initiation factor complex eIF4F into N-terminal (Nt) and C-terminal (Ct) domains. Previously we showed that, although in vitro cleavage of the translation initiation factor, eIF4G, with L protease decreases cap-dependent translation, the cleavage products themselves may directly promote cap-dependent protein synthesis. We now demonstrate that translation of uncapped mRNAs normally exhibits a strong requirement for eIF4F. However, this dependence is abolished when eIF4G is cleaved, with the Ct domain capable of supporting translation in the absence of the Nt domain. In contrast, the efficient translation of the second cistron of bicistronic mRNAs, directed by two distinct Internal Ribosome Entry Segments (IRES), exhibits no requirement for eIF4E but is dependent upon either intact eIF4G or the Ct domain. These results demonstrate that: (i) the apparent requirement for eIF4F for internal initiation on IRES-driven mRNAs can be fulfilled by the Ct proteolytic cleavage product; (ii) when eIF4G is cleaved, the Ct domain can also support cap-independent translation of cellular mRNAs not possessing an IRES element, in the absence of eIF4E; and (iii) when eIF4G is intact, translation of cellular mRNAs, whether capped or uncapped, is strictly dependent upon eIF4E. These data complement recent work in other laboratories defining the binding sites for other initiation factors on the eIF4G molecule.

Expression of adhesion molecules in peripheral pulmonary vessels from smokers and nonsmokers

INTRODUCTION AND RATIONALE

An accumulation of intraalveolar cells, especially of macrophages and granulocytes, can be observed in smokers. Since adhesion molecules are involved in the process of cell accumulation, in this study we investigated the hypothesis that the expression of endothelial adhesion molecules on pulmonary vascular endothelial cells is different in smokers and nonsmokers.

METHODS

We investigated lung biopsies from 26 patients who underwent thoracic surgery for localized malignancies (smokers: 15; nonsmokers: 11). Cryostat sections were stained by using immunohistochemistry (APAAP method) with antibodies against E- and P-selectin, the vascular adhesion molecule-1 (VCAM-1), and the intercellular adhesion molecule-1 (ICAM-1). The number of adhesion molecule-positive stained vessels was compared to the total number of vessels identified by the expression of von Willebrand's factor (vWF) and anti-CD31.

RESULTS

The two groups investigated showed no differences in the expression of E-, and P-selectin and of VCAM-1. In contrast, the expression of ICAM-1 was significantly increased in smokers (median 25 vessels/section, CI95%: 19-31) compared to nonsmokers (median 16 vessels/section, CI95%: 9-21) (p = 0.030). In smoking subjects, we were also able to demonstrate a positive correlation between the duration of smoking expressed as pack years and the expression of ICAM-1 on pulmonary vessels (Spearman rank coefficient of correlation 0.857; p = 0.0002).

CONCLUSION

The observed increased expression of ICAM-1 on pulmonary vascular endothelial cells in smokers compared to nonsmokers may be involved in the increased recruitment of inflammatory cells to the alveolar space of smokers.