MIF but not MIF-2 recruits inflammatory macrophages in an experimental polymicrobial sepsis model

Excessive inflammation drives the progression from sepsis to septic shock. Macrophage migration inhibitory factor (MIF) is of interest because MIF promoter polymorphisms predict mortality in different infections, and anti-MIF antibody improves survival in experimental models when administered 8 hours after infectious insult. The recent description of a second MIF superfamily member, D-dopachrome tautomerase (D-DT/MIF-2), prompted closer investigation of MIF-dependent responses. We subjected Mif-/- and Mif-2-/- mice to polymicrobial sepsis and observed a survival benefit with Mif but not Mif-2 deficiency. Survival was associated with reduced numbers of small peritoneal macrophages (SPMs) that, in contrast to large peritoneal macrophages (LPMs), were recruited into the peritoneal cavity. LPMs produced higher quantities of MIF than SPMs, but SPMs expressed higher levels of inflammatory cytokines and the MIF receptors CD74 and CXCR2. Adoptive transfer of WT SPMs into Mif-/- hosts reduced the protective effect of Mif deficiency in polymicrobial sepsis. Notably, MIF-2 lacks the pseudo-(E)LR motif present in MIF that mediates CXCR2 engagement and SPM migration, supporting a specific role for MIF in the recruitment and accumulation of inflammatory SPMs.

Differential regulation of macrophage activation by the MIF cytokine superfamily members MIF and MIF-2 in adipose tissue during endotoxemia

Sepsis is a leading cause of death worldwide and recent studies have shown white adipose tissue (WAT) to be an important regulator in septic conditions. In the present study, the role of the inflammatory cytokine macrophage migration inhibitory factor (MIF) and its structural homolog D-dopachrome tautomerase (D-DT/MIF-2) were investigated in WAT in a murine endotoxemia model. Both MIF and MIF-2 levels were increased in the peritoneal fluid of LPS-challenged wild-type mice, yet, in visceral WAT, the proteins were differentially regulated, with elevated MIF but downregulated MIF-2 expression in adipocytes. Mif gene deletion polarized adipose tissue macrophages (ATM) toward an anti-inflammatory phenotype while Mif-2 gene knockout drove ATMs toward a pro-inflammatory phenotype and Mif-deficiency was found to increase fibroblast viability. Additionally, we observed the same differential regulation of these two MIF family proteins in human adipose tissue in septic vs healthy patients. Taken together, these data suggest an inverse relationship between adipocyte MIF and MIF-2 expression during systemic inflammation, with the downregulation of MIF-2 in fat tissue potentially increasing pro-inflammatory macrophage polarization to further drive adipose inflammation.

Selective Recruitment of Lethal Pro-inflammatory Macrophages in Sepsis by MIF but not D-DT (MIF-2)

Sepsis is a leading cause of mortality with an estimated global incidence of 30 million cases annually. Current paradigms emphasize the role of an overwhelming or dysregulated inflammatory response in sepsis lethality, but to date interventions aimed at particular inflammatory pathways have been unsuccessful. Macrophage migration inhibitory factor (MIF) is of interest because MIF promoter polymorphisms predict mortality in different infections and anti-MIF antibody improves survival in experimental models when administered eight hours after infectious insult. The recent description of a second MIF superfamily member, D-dopachrome tautomerase (D-DT/MIF-2), prompts closer investigation of MIF-dependent responses. This study provides new insight into the pathophysiology of polymicrobial sepsis by revealing a direct role for MIF, but not its close structural homolog D-DT/MIF-2, in activating and recruiting a lethal macrophage subset. We subjected Mif −/− and Mif-2−/− mice to polymicrobial sepsis and observed a survival benefit with Mif but not Mif-2 deficiency. Survival was associated with lower levels of small peritoneal macrophages (SPMs) that, in contrast to large peritoneal macrophages (LPMs), are recruited to site of peritoneal inflammation during sepsis. LPMs produce higher quantities of MIF than SPMs, but SPMs express higher levels of inflammatory cytokines and MIF receptors CD74 and CXCR2. Adoptive transfer of SPMs into Mif −/− hosts abrogated the protective effect of Mif deficiency. Notably, MIF-2 lacks the pseudo-(E)LR motif present in MIF that mediates CXCR2 engagement and SPM migration, supporting MIF’s selective role in the recruitment and accumulation of lethal inflammatory SPMs.

[Hemoptysis in Pregnancy]

Here we present an extremely rare but important cause of pulmonary hemorrhage during pregnancy. A 41-year-old patient was seen with hemoptysis in the 29th week of her pregnancy which was initially assessed as unspecific inflammation. At the 34th week of pregnancy, she presented again, this time with hemoptoe and dizziness caused by an unknown idiopathic pulmonary AV malformation. The patient underwent extensive interdisciplinary evaluation including bronchoscopy, emergency cesarean section was performed, which was followed by CT scan and VATS/minithoracotomy with segment resection.

Fibrinolytische Aktivität von Handelsthrombinen und ihr Einfluß auf die Genauigkeit der Standard-fibrinplattenmethode

Handelsübliche Thrombinpräparate besitzen eine fabrikatabhängige und chargenabhängige fìbrinolytische Aktivität. Diese ist vorwiegend auf den Gehalt an Plasminogenaktivator- und -proaktivator zurückzuführen. Werden diese Präparate zur Herstellung von Standardfibrinplatten benutzt, so kann eine völlige Verfälschung der Testergebnisse resultieren, weil eine »Autolyse« der Platte eintritt. Versuche mit verschiedenen zur Plattenherstellung benutzten Thrombinpräparaten beweisen dies und zeigen außerdem, daß ein Zusatz von Akridin möglicherweise geeignet ist »stabilere« Standardfibrinplatten herzustellen.

Erfassung der pneumologisch-fachärztlichen Versorgungsstrukturen für Patienten mit interstitiellen Lungenerkrankungen in Nordrhein-Westfalen

Ziel der Studie Erfassung der Versorgungsrealität von interstitiellen Lungenerkrankungen (ILD) in Nordrhein-Westfalen.

Methodik Die Westdeutsche Gesellschaft für Pneumologie erfasste ILD-Schwerpunktstandorte mittels postalischer Abfrage. Struktur- und Prozessqualität wurden in einem Fragebogen evaluiert.

Ergebnisse 49 Standorte wurden registriert, 46 stellten ihre Standortdaten zur Verfügung (15 Facharztpraxen, 34 pneumologische Krankenhausabteilungen). Im Median werden in den Praxen im Jahr 360 ILD-Patienten gesehen (26 % Erstdiagnosen), in den Krankenhäusern 105 ILD-Patienten (63 % Erstdiagnosen). 10 Standorte stellen über 100 ILD-Erstdiagnosen pro Jahr. Die Praxen berichten im Median 50 Bronchoskopien im Jahr, die Krankenhäuser im Median 1396. 78 % der Standorte partizipieren an einer interdisziplinären ILD-Fallkonferenz.

Schlussfolgerung In Nordrhein-Westfalen existieren mehrere ILD-Versorgungsstandorte mit hoher Expertise. Ambulant erfolgt v. a. das Monitoring von ILD-Patienten, stationär werden eher komplexe ILD-Erstabklärungen oder ungewöhnliche Verläufe betreut. Standorte mit einem realen regionalen ILD-Versorgungsauftrag sollten in ihrer Weiterentwicklung gefördert werden.

Thrombolyse: Direktbestimmung fibrinolytischer Substanzen durch die statische Retraktrometrie

Durch die statische Messung der Retraktionskraft in Abhängigkeit von der Zeit können Veränderungen der Fibrinbildung und die Fibrinolyse bestimmt werden. In einem hinsichtlich Konstruktion und Gebrauch genau beschriebenen Versuchsgefäß kann man die Gerinnseloberfläche zu einem gewünschten Zeitpunkt während oder nach Abschluß der Retraktion fìbrinolytischen Substanzen aussetzen. Unter gleichzeitiger und fortlaufender Messung läßt sich die Konzentration dieser Substanzen verändern. Erste - statistisch noch ungesicherte - Ergebnisse deuten auf eine unterschiedliche Lysegeschwindigkeit und Intensität in Abhängigkeit von der primären Streptokinasekonzentration hin. Bei gleicher Endkonzentration in zwei Gefäßen ist der lytische Effekt geringer, wenn die Endkonzentration durch zweimalige Streptokinasezugabe in zeitlichen Abstand eingestellt wird. - Neben einer genauen Beschreibung der Versuchstechnik wird auf weitere Möglichkeiten der Methode hingewiesen.

The Influence of Fine Surface Structures on the Osseo-integration of Implants

The availability of inert materials like dense, pure Al-2O3-ceramic or titanium allows the study of purely biomechanical influences of surface modulations or lacune on the osseo-integration of implants at different locations of the skeleton. The discovery of the «load-line-shadow» phenomenon in lacune of dental implants and the observation of the same effect in the grooves of hip sockets (Lindenhof type) indicate the general validity of the rules controlling the remodelling ability of bony tissue. Their application to the problems concerned with load transmission via surfaces which are mainly loaded by shear can contribute to achieve a well defined anchorage of implants.

MIF-2/D-DT enhances proximal tubular cell regeneration through SLPI- and ATF4-dependent mechanisms

Macrophage migration inhibitory factor (MIF) is a cytokine with pleiotropic actions that is produced by several organs and cell types. Depending on the target cell and the inflammatory context, MIF can engage its two component receptor complex CD74 and CD44 and the chemokine receptors CXCR2/4. MIF is constitutively expressed in renal proximal tubular cells, stored in intracellular preformed pools, and released at a low rate. Recently, a second MIF-like protein (i.e., MIF-2/D-DT) has been characterized in mammals. Our study was aimed at examining the role of MIF-2/D-DT, which mediates tissue protection in the heart, in tubular cell regeneration from ischemia-reperfusion injury. We found that Mif-/-, Mif-2-/-, and Cd74-/- mice had significantly worse tubular injury compared with wild-type (WT) control mice and that treatment with MIF-2/D-DT significantly improved recovery of injured epithelial cells. RNAseq analysis of kidney tissue from the ischemia-reperfusion injury model revealed that MIF-2/D-DT treatment stimulates secretory leukocyte proteinase inhibitor (SLPI) and cyclin D1 expression. MIF-2/D-DT additionally activates of eukaryotic initiation factor (eIF) 2α and activating transcription factor (ATF) 4, two transcription factors involved in the integrated stress response (ISR), which is a cellular stress response activated by hypoxia, nutrient deprivation, and oxygen radicals. MIF-2/D-DT also inhibited apoptosis and induced autophagy in hypoxia-treated mouse proximal tubular (MPT) cells. These results indicate that MIF-2/D-DT is an important factor in tubular cell regeneration and may be of therapeutic utility as a regenerative agent in the clinical setting of ischemic acute kidney injury.

D-dopachrome tautomerase in adipose tissue inflammation and wound repair

D-dopachrome tautomerase (D-DT/MIF-2) is a member of the macrophage migration inhibitory factor (MIF) cytokine superfamily, and a close structural homolog of MIF. MIF and D-DT have been reported to be involved in obesity, but there is little known about the regulation of D-DT in adipose tissue inflammation and wound healing. Subcutaneous adipose tissue was collected from 54 healthy donors and 28 donors with acutely inflamed wounds undergoing wound debridement. In addition, epididymal fat pads of mice were injected with lipopolysaccharide to study receptor expression and cell migration in vivo. D-DT protein levels and mRNA expression were significantly decreased in subcutaneous adipose tissue adjacent to acutely inflamed wounds. D-DT improved fibroblast viability and increased proliferation in vitro. While D-DT alone did not have a significant effect on in vitro fibroblast wound healing, simultaneous addition of neutralizing MIF antibody resulted in a significant improvement of fibroblast wound healing. Interestingly, expression of the MIF and D-DT receptor CD74 was down-regulated while the MIF receptors CXCR2 and CXCR4 were up-regulated primarily on macrophages indicating that the MIF-CXCR2/4 axis may promote recruitment of inflammatory cells into adipose tissue. Our results describe a reciprocal role of D-DT to MIF in inflamed adipose tissue, and indicate that D-DT may be beneficial in wound repair by improving fibroblast survival and proliferation.

The clinical significance of the MIF homolog d-dopachrome tautomerase (MIF-2) and its circulating receptor (sCD74) in burn

BACKGROUND

We reported earlier that the cytokine macrophage migration inhibitory factor (MIF) is a potential biomarker in burn injury. In the present study, we investigated the clinical significance of the newly discovered MIF family member d-dopachrome tautomerase (DDT or MIF-2) and their common soluble receptor CD74 (sCD74) in severely burned patients.

METHODS

DDT and sCD74 serum levels were measured 20 severely burned patients and 20 controls. Serum levels were correlated to the abbreviated burn severity index (ABSI) and total body surface area (TBSA) followed by receiver operating characteristic (ROC) analysis. Data were supported by gene expression dataset analysis of 31 burn patients and 28 healthy controls.

RESULTS

CD74 and DDT were increased in burn patients. Furthermore, CD74 and DDT also were elevated in septic non-survivors when compared to survivors. Serum levels of DDT showed a positive correlation with the ABSI and TBSA in the early stage after burn, and the predictive character of DDT was strongest at 24h. Serum levels of CD74 only correlated with the ABSI 5 days after injury.

CONCLUSIONS

DDT may assist in the monitoring of clinical outcome and prediction of sepsis during the early post-burn period. Soluble CD74 and MIF, by contrast, have limited value as an early predictor of death due to their delayed response to burn.

Interaction of MIF Family Proteins in Myocardial Ischemia/Reperfusion Damage and Their Influence on Clinical Outcome of Cardiac Surgery Patients

AIMS

Cardiac surgery involves myocardial ischemia/reperfusion (I/R) with potentially deleterious consequences. Macrophage migration inhibitory factor (MIF) is a stress-regulating chemokine-like cytokine that protects against I/R damage, but functional links with its homolog, d-dopachrome tautomerase (MIF-2), and the circulating soluble receptor CD74 (sCD74) are unknown. In this study, we investigate the role of MIF, MIF-2, sCD74, and MIF genotypes in patients scheduled for elective single or complex surgical procedures such as coronary artery bypass grafting or valve replacement.

RESULTS

MIF and MIF-2 levels significantly increased intraoperatively, whereas measured sCD74 decreased correspondingly. Circulating sCD74/MIF complexes were detectable in 50% of patients and enhanced MIF antioxidant activity. Intraoperative MIF levels were independently associated with a reduced risk for the development of atrial fibrillation (AF) (odds ratio 0.99 [0.98-1.00]; p=0.007). Circulating levels of MIF-2, but not MIF, were associated with an increased frequency of organ dysfunction and predicted the occurrence of AF (area under the curve [AUC]=0.663; p=0.041) and pneumonia (AUC=0.708; p=0.040). Patients with a high-expression MIF genotype exhibited a reduced incidence of organ dysfunction compared with patients with low-expression MIF genotypes (3 vs. 25; p=0.042).

INNOVATION

The current study comprehensively highlights the kinetics and clinical relevance of MIF family proteins and the MIF genotype in cardiac surgery patients.

CONCLUSION

Our findings suggest that increased MIF levels during cardiac surgery feature organ-protective properties during myocardial I/R, while the soluble MIF receptor, sCD74, may enhance MIF antioxidant activity. In contrast, high MIF-2 levels are predictive of the development of organ dysfunction. Importantly, we provide first evidence for a gene-phenotype relationship between variant MIF alleles and clinical outcome in cardiac surgery patients.

Operative Management of Hilar Renal Artery Aneurysm in a Pregnant Patient

Complications of renal artery aneurysms (RAAs) can be life threatening and include the spontaneous rupture which may lead to severe retroperitoneal hemorrhage, loss of the kidney, or death. As the incidence and diagnosis of RAAs is expected to rise, it is becoming increasingly important to enhance our awareness and knowledge of this rare clinical entity. Here, we present the case of a hilar right RAA and the surgical approach for primary repair during the postpartum period. Additionally, we discuss current pathophysiologic mechanisms, associated symptoms as well as current treatment modalities for RAAs.

[A very rare cause of haemoptysis - coexistence of primary oncocytic adenoma of trachea with bronchial carcinoma]

HISTORY AND ADMISSION FINDINGS

A 70-year-old man with a past history of COPD stage GOLD D with home oxygen therapy and tracheotomy due to long-term ventilation (898 hours) 6 years ago was admitted for investigation of haemoptysis during oral anticoagulation. He suffered from peripheral arterial disease (PAD) with bypass and repeated thrombectomy due to recurrent bypass caps, despite effective warfarin therapy. He had all cardiovascular risk factors.

INVESTIGATIONS

The suspicion of a bronchial carcinoma was confirmed by CT. Bronchoscopically a 2 cm lesion in the left upper lobe was biopsied. Additionally, bronchoscopy revealed an approximately erythematous, bloody discolored lesion (diameter 7 mm) at a tracheotomy scar.

DIAGNOSIS, TREATMENT AND COURSE

The biopsies revealed an adenocarcinoma in the left upper lobe and an oncocytic adenoma of the trachea - an extremely rare adenoma. The staging result was cT1b cN0 cM0 G2 IASLC Ia. Because of his severe multiple diseases the patient was in an inoperable condition. An interdisciplinary tumor conference recommended an individualized approach with a definitive radiotherapy of the adenocarcinoma. Endoscopic control of the macroscopically completely removed oncocytic adenoma of the trachea shall be performed one year later.

CONCLUSIONS

Oncocytoma is an extremely rare adenoma (of the trachea), which in this case, has caused haemoptysis in addition to lung cancer during anticoagulation. For tumor genesis a reactive or hyperplasic response after tracheotomy 6 years ago is considered. Resection is the treatment of choice because of the potential for infiltrative growth. But the decision to treat always depends on individual benefit.

Cytokines in sepsis: potent immunoregulators and potential therapeutic targets--an updated view

Sepsis and septic shock are among the leading causes of death in intensive care units worldwide. Numerous studies on their pathophysiology have revealed an imbalance in the inflammatory network leading to tissue damage, organ failure, and ultimately, death. Cytokines are important pleiotropic regulators of the immune response, which have a crucial role in the complex pathophysiology underlying sepsis. They have both pro- and anti-inflammatory functions and are capable of coordinating effective defense mechanisms against invading pathogens. On the other hand, cytokines may dysregulate the immune response and promote tissue-damaging inflammation. In this review, we address the current knowledge of the actions of pro- and anti-inflammatory cytokines in sepsis pathophysiology as well as how these cytokines and other important immunomodulating agents may be therapeutically targeted to improve the clinical outcome of sepsis.

Interferon-lambda serum levels in hepatitis C

BACKGROUND & AIMS

Dendritic cells (DCs) trigger adaptive immune responses and are an important source of antiviral cytokines. In hepatitis C virus (HCV) infection DC function is markedly impaired. Thus far, studies have focused on types I and II interferon (IFN). We studied IFN-lambda1 (IL-29) and IFN-lambda2/3 (IL-28A/B) serum levels in patients with different outcomes of HCV infection.

METHODS

IFN-lambdas were measured by ELISAs detecting IL-29 or IL-28A and IL-28B, respectively. Results were stratified with respect to the recently discovered rs12979860 T/C polymorphism upstream of the IL-28B gene.

RESULTS

In general IL-29 serum levels exceeded IL-28A/B at least twofold, with IL-29 and IL-28A/B levels being significantly higher in carriers of the rs12979860 C allele than in TT homozygous individuals (p<0.02). IL-29 levels were substantially lower in patients with chronic hepatitis C than in healthy controls (p=0.005) and patients with spontaneously resolved hepatitis (p=0.001). Patients with acute hepatitis C showed IL-29 levels intermediate between chronic hepatitis C and normal controls; and IL-29 serum levels were higher in patients who spontaneously resolved hepatitis C than in those who became chronic. In vitro HCV proteins NS3 and E2 directly inhibited IL-29 production in poly I:C-stimulated purified DCs.

CONCLUSIONS

Our data suggest that HCV proteins modify IFN-lambda production in DCs. Carriers of the rs12979860 C allele associated with resolution of HCV infection exhibited increased IFN-lambda levels. Moreover, high IFN-lambda levels predisposed to spontaneous resolution of HCV infection. Thus, IFN-lambdas seem to play an important role in the control of hepatitis C.

Kardiale Sarkoidose

Sarcoidosis is a systemic disease, in which early inflammatory organic changes, which are often reversible under treatment, may take a subclinical course. In scarred residual tissue improvement id rare. Continuing functional loss or even organ failure is possible. The involvement of the heart is of essential prognostic value. Early onset of treatment with corticosteroids before irreversible functional loss of the heart occurs leads to an excellent prognosis. Technical progress in the imaging techniques have led to great improvement of the graphical presentation of cardiac structure and function, but not one of these techniques has yet been approved of for early diagnosis. Still, a combination of different diagnostical measures in addition to the evaluation of clinical symptoms often allows early diagnosis. A decisive factor is "to consider it" and a timely start of further diagnostics if certain symptoms are presented. Alternatives to the specific treatment with cortisone are still lacking. Symptomatic cardiac treatment is mainly oriented on the therapy of dilatory cardiomyopathies, since there are no reliable systematic studies available on questions concerning, for example, antiarrhythmic treatment or indications for the implantations of pacemakers in connection with cardiac sarcoidosis.

Idiopathic bronchiolitis mimicking diffuse panbronchiolitis

Diffuse panbronchiolitis (DPB) is a distinct sinobronchial syndrome which has been almost exclusively reported in East Asia; only a few cases have been observed in non-Asians so far. Since 1990, when one of us described the first European case, we have screened all patients presenting with a clinical, physiopathological and radiological pattern compatible with DPB, in order to assess if the paucity of proven cases in Europe could reflect a lack of awareness of this disease among both pulmonologists and pathologists. Over a 10-years period we identified four additional DPBs, but also interestingly observed five cases of "idiopathic" bronchiolitis (IB) that had both clinical symptoms and high-resolution computed tomography (HRCT) findings indistinguishable from those of DPB, but did not show the typical histological changes. All these patients were Caucasians and presented with dyspnea, productive cough, an obstructive or mixed impairment on pulmonary function tests and chest HRCT features strongly suggesting a grade II to IV DPB. We suggest that diseases classified as IB in this study might be homogeneous entities which are clinically and radiologically similar to DPB.

Immediate postextraction implant placement with root-analog stepped implants: surgical procedure and statistical outcome after 6 years

The present study investigated 124 stepped-screw implants (gritblasted and acid-etched surface) placed in 104 patients immediately after tooth extraction or implant explantation and followed between August 1990 and December 1996. Implants of varying diameters and lengths were used to cover a wide range of indications in both the maxilla and mandible; 68% of the implants supported single-tooth replacements. The study parameters included Plaque Index, Gingival Index, probing depth, Periotest values, and peri-implant bone loss. Statistical analysis according to Kaplan-Meier revealed a 97% survival rate.

[Diffuse panbronchiolitis. A rare differential diagnosis of chronic obstructive lung disease]

HISTORY AND ADMISSION FINDINGS

A 36-year-old Korean had since childhood suffered from a chronic progressive lung disease, marked by dyspnoea, productive cough and recurrent sinusitis. He was in a reduced general condition on admission. There were hyperresonant sounds on palpation over both lungs, a low diaphragm and slight vesicular breath sound as well as occasional rales and sibilant rhonchi.

INVESTIGATIONS

Laboratory tests showed increased blood cell sedimentation of 52 mm at 1 h, leukocytosis of 24.3/nl, and a raised cold-agglutinin titre. Haemophilus influenza and Pseudomonas aerogenes were cultured from the bronchial secretion. Lung function tests revealed severe obstruction with hyperinflation and partial respiratory failure with a much reduced 1-sec forced expiratory volume (FEV1) of 0.71, 19% of normal; residual volume (RV) 6.61, 550% of normal; arterial oxygen partial pressure 61 mm Hg; arterial CO2 partial pressure 36 mm Hg. Chest X-ray showed emphysematous changes with diffuse small nodular shadows. Bronchoalveolar lavage revealed 96% neutrophils, indicating marked granulocytic inflammation. A video-assisted thoracoscopic biopsy was performed which showed diffuse panbronchiolitis.

TREATMENT AND COURSE

The symptoms, radiological changes and lung functions clearly improved under long-term treatment with 500 mg erythromycin daily.

CONCLUSION

Diffuse bronchiolitis is rarely seen outside of Asia, but it should be included in the differential diagnosis because, in contrast to other forms of chronic obstructive lung disease, it responds to long-term erythromycin medication.

Area-dependent enlargement ratios of panoramic tomography on orthograde patient positioning and its significance for implant dentistry

The aim of this work was to study the behavior of vertical and horizontal enlargement ratios in panoramic tomography in various implant regions of the maxilla and the mandible. A method is presented that admits determination of regional enlargement ratios as a function of the implant region. Clearly defined characteristics of the implant body (Frialit-2 implants) are used as reference points. The vertical enlargement ratio varied between 1.21 and 1.29 on optimal orthograde adjusted tomographs, depending on the measured area. The horizontal enlargement ratio at the coronal end of the implant varied between 1.15 and 1.35. As it is below the vertical value in the lateral tooth area, this contributes to the distortion of the implant structures depicted. The horizontal enlargement at the apical end of the implant varies between 1.12 and 1.44. The difference in horizontal enlargement ratios also causes a distortion of the implant structures shown on the panoramic tomograph. Based on this study scenario, panoramic tomography may be well suited to preimplant diagnosis, particularly in the vertical dimension. With regard to transparent templates designed for implant placement, an enlargement of 1.3 in the perpendicular line and 1.35 in the horizontal line is proposed.

Study of interface phenomena between bone and titanium and alumina surfaces in the case of monolithic and composite dental implants

The interface between mandibular bone and dental implants was examined with the in vivo dog model. Implant/bone interfaces were investigated for three types of materials: Ti-30 wt% Ta/Al2O3, titanium and Al2O3 using microscopy techniques covering a large magnification range: scanning electron microscopy, transmission electron microscopy, energy dispersive X-ray analysis and Auger spectroscopy. During the interaction of the Al2O3 ceramic with bone, an interfacial layer about 15 microm thick is formed. The same phenomenon was observed at the titanium bone interface, where the thickness of the layer was about 10 microm. In all cases, interface layers were sharp with well-defined borders between bone tissue and implant materials. No calcification took place inside the interface layer. A chemical analysis performed on this layer shows the presence of titanium, calcium and phosphorus in the case of titanium implants, and aluminium, calcium and phosphorus in the case of alumina implants. A rapid decrease in metal composition with increasing distances from the implant surface is correlated to a slow increase in calcium and phosphorus in the direction of the bone. Direct contact between implant and bone was observed. No biocorrosive effects were detected at the Ti-30 wt% Ta/Al2O3 metal-ceramic interface.

The Frialit-2 implant system: five-year clinical experience in single-tooth and immediately postextraction applications

In an observational study of 696 Frialit-2 implants in 376 patients that was carried out between 1990 and 1995, implants of varying diameters and lengths were delivered for a range of indications in the maxilla and mandible. Single-tooth replacement was performed in 42% of cases; of these, 22.4% were placed immediately following extraction. Study parameters (Plaque Index, Gingival Index, probing depth, Periotest value, and peri-implant bone loss) are reported in detail. Statistical analysis is based on a 97.6% rate of recall. The overall success rate was found to be 96% using the Kaplan-Meier statistical analysis. No difference was apparent between single-tooth applications and prosthesis restorations.

Multi-functional acetyl-CoA carboxylase from Brassica napus is encoded by a multi-gene family: indication for plastidic localization of at least one isoform

Three genes coding for different multifunctional acetyl-CoA carboxylase (ACCase; EC 6.4.1.2) isoenzymes from Brassica napus were isolated and divided into two major classes according to structural features in their 5' regions: class I comprises two genes with an additional coding exon of approximately 300 bp at the 5' end, and class II is represented by one gene carrying an intron of 586 bp in its 5' untranslated region. Fusion of the peptide sequence encoded by the additional first exon of a class I ACCase gene to the jellyfish Aequorea victoria green fluorescent protein (GFP) and transient expression in tobacco protoplasts targeted GFP to the chloroplasts. In contrast to the deduced primary structure of the biotin carboxylase domain encoded by the class I gene, the corresponding amino acid sequence of the class II ACCase shows higher identity with that of the Arabidopsis ACCase, both lacking a transit peptide. The Arabidopsis ACCase has been proposed to be a cytosolic isoenzyme. These observations indicate that the two classes of ACCase genes encode plastidic and cytosolic isoforms of multi-functional, eukaryotic type, respectively, and that B. napus contains at least one multi-functional ACCase besides the multi-subunit, prokaryotic type located in plastids. Southern blot analysis of genomic DNA from B. napus, Brassica rapa, and Brassica oleracea, the ancestors of amphidiploid rapeseed, using a fragment of a multi-functional ACCase gene as a probe revealed that ACCase is encoded by a multi-gene family of at least five members.

Radiographic imaging of the hard palate and maxillary third molars with spiral tomography: a novel technique of patient positioning

The Scanora spiral tomography system can be used to solve a range of imaging problems in the maxillofacial region. However, the system has no specific programs for imaging bony lesions of the hard palate or medially and cranially displaced maxillary third molars. New patient-positioning techniques were therefore developed on the basis of phantom radiographs, and their successful application in patients is presented. With the novel techniques, good radiographic representations of the hard and soft palates in the posteroanterior and lateral projections and of maxillary third molars were achieved.

Effects of various hygiene procedures on the surface characteristics of titanium abutments

The use of cleaning instruments on titanium implants may cause undesired surface alterations. In a qualitative and quantitative assessment of these alterations, 5 titanium implant abutments were treated with a steel curet, a prototype pure titanium curet, an air abrasive polishing system, and an ultrasonic system. Custom-made polymer templates, used to secure the curet to a vertical guide bar and a spring scale to maintain a constant instrument pressure, guaranteed a standardized procedure and reproducible results. The ultrasonic and the air abrasive polishing method were also standardized. Evaluation by scanning electron microscopy (SEM) revealed surface alterations for all instruments and systems except the plastic curet, which did not roughen the surface at all. The confocal laser-scanning microscope allows a 3-dimensional reproduction of these surface alterations and their direct measurement. The profilometric tracing was not sensitive enough to register the minor effects caused by the titanium curet and the air abrasive polishing system. Dimensions of the resulting surface microstructure could be determined with the laser-scanning microscope. Since the influence of such surface defects on the peri-implant tissue reaction is unpredictable, the titanium curet and the air abrasive system can only be recommended with restrictions. The steel curet and the ultrasonic system proved to be totally unsuitable for cleaning titanium implants.

Implants and the periodontium

This paper compares the morphology and function of the natural periodontium with peri-implant tissues and tissue reactions. The comparison serves as a base for observations about the practical application of oral endosseous implants. The main conclusion is that the touch sensitivity of natural teeth at lower biting and chewing loads, that is in the phase of primary tooth mobility, during which only the soft parts of the periodontium are deformed, cannot be substituted by ankylotic retained implants.

Pinch-off syndrome: a rare etiology for central venous catheter occlusion

BACKGROUND

Catheter pinch-off syndrome is a rare and often misdiagnosed complication of tunneled Silastic central venous catheters. Pinch-off syndrome occurs when the catheter is compressed between the first rib and the clavicle, causing an intermittent mechanical occlusion for both infusion and withdrawal. We report its incidence in a large series of catheter insertions and describe the clinical presentation, radiographic findings, and recommended treatment.

METHODS

A total of 1457 tunneled Silastic central venous catheters that were inserted using the percutaneous subclavian approach were prospectively studied. Indications for catheter placement included bone marrow transplant, continuous or intermittent chemotherapy, long-term antibiotics, and parenteral nutrition. Catheters were evaluated for clinical presentation of an occlusion relieved by postural changes and radiographic findings of luminal narrowing.

RESULTS

Pinch-off syndrome was identified in 16 (1.1%) catheters. Radiographic findings were present in all catheters; clinical findings were present in 15 catheters. Clinical symptoms presented within a median of 2 days after placement (range, 0 to 167 days). Partial or complete catheter transection, a serious sequela of catheter pinch-off syndrome, occurred in 19% of the identified catheters.

CONCLUSIONS

(1) Catheter pinch-off syndrome presents clinically as a catheter occlusion related to postural changes; (2) clinical symptomatology should be confirmed radiographically; and (3) catheter removal with a more lateral replacement in the subclavian vein or in the internal jugular vein will avoid a recurrent complication.

Development and functionality of isoelastic dental implants of titanium alloys

Two types of isoelastic endosseous dental implants were produced and their functionality was tested. One type consisted of a porous sintered TiTa30 alloy, the other had a special surface structure consisting of titanium wire loops. Their mechanical properties were optimized by the production parameter (sintering and diffusion bonding, respectively). The functionality was tested after insertion into an artificial jaw which had properties corresponding to the natural mandibular. The elastic properties of both implants were similar to the properties of the bone. In addition the implants have a safe anchorage bone ingrowth. In animal experiments using the implant with surface loops it was observed that the bone entered the loops and even extremely small surface cavities in the wire loops.

Renal hemodynamics and cardiovascular reactivity in the prehypertensive stage

To examine whether sympathetic nervous activation has an impact on renal circulation in subjects at risk for high blood pressure, we assessed renal hemodynamics and cardiovascular response to mental stress in 40 healthy young white males, 12 normotensive subjects without and 14 with familial hypertension, and 14 with borderline hypertension. The response of systolic and diastolic blood pressure to mental stress was assessed while each patient performed a mental arithmetic task; this was taken as the parameter for the activation of the sympathetic nervous system. Renal plasma flow was measured by para-aminohippuric acid clearance under steady-state conditions. In parallel, glomerular filtration rate as a parameter for functional impairment of the kidneys was determined by creatinine clearance, and filtration fraction was also calculated. Patients with borderline hypertension were characterized by a reduced renal blood flow and increased filtration fraction in comparison with both normotensive groups. The increase in systolic blood pressure during mental stress was more pronounced in borderline hypertensives. We observed no significant difference in renal hemodynamics and cardiovascular response to mental stress between normotensives with and without a family history of hypertension. In the total population, cardiovascular response to mental stress was correlated with renal hemodynamics: The greater the increase in systolic blood pressure during mental stress, the lower was the renal plasma flow and the greater the filtration fraction. Thus, renal plasma flow was found to be already reduced and filtration fraction increased before sustained hypertension developed. Because this pattern in renal hemodynamics was related to cardiovascular response to mental stress, our data suggest that sympathetic activation already appeared to affect renal hemodynamics at the onset of essential hypertension.

The Periotest method

The Periotest is a new instrument for the diagnosis of periodontal diseases. The 'Periotest value' depends to some extent on tooth mobility, but mainly on the damping characteristics of the periodontium. The Periotest measures the reaction to a reproducible impact applied to the tooth crown. The Periotest value is a biophysical parameter.

High-speed filming of the Periotest measurement

Periodontal disease may be diagnosed with the Periotest technique, which involves electronically controlled and reproducible percussion of tooth. The movement on percussion was investigated with high-speed film and then compared with the return of teeth after static deflection for several seconds as has been reported previously by Lukas and Scholz. The elastic and viscous properties of the periodontium and the surrounding bony tooth socket are to a large extent non-linear. The 10-20 microns deflection of the healthy tooth represents only a fraction of static tooth mobility published by Parfitt or Schulte et al. The visco-elastic properties of a healthy tooth enabling the percussion of the Periotest tapping head to be decelerated in less than 1 ms are largely lost in periodontitis. It is this essential difference which the Periotest method utilizes.

Impact of angiotensin converting enzyme inhibition on the haemodynamic profile during laboratory stress tests

To determine the haemodynamic profile of angiotensin converting enzyme (ACE) inhibitors during stress, the cardiovascular response to various stress tests was examined in patients with essential hypertension before and after three months of therapy with lisinopril. Eighteen white patients were enrolled in the trial, of whom 12 completed the protocol. ACE inhibition with lisinopril effectively reduced systolic and diastolic pressure in the office (P less than 0.001), at rest (P less than 0.002), during mental stress (P less than 0.003), cold pressor test (P less than 0.003), and reaction time task (P less than 0.05). During physical exercise only diastolic pressure was significantly reduced (P less than 0.02). The fall in peak systolic pressure during cold pressor test and reaction time task was more pronounced than the fall in casual systolic pressure (P less than 0.05). At rest, cardiac output was unchanged, but total peripheral resistance was reduced after medication with lisinopril (P less than 0.05). During the cold pressor test, the increase in total peripheral resistance was attenuated by ACE inhibition (P less than 0.04). The haemodynamic response profile was not altered during the other tests. It is concluded that in middle-aged men ACE inhibitors reduce blood pressure during a variety of stressful events without altering the haemodynamic profile and even attenuating vasoconstriction during stress. This response pattern to ACE inhibition with lisinopril may reduce the impact of recurring stress-induced increases of blood pressure and of exaggerated vasoconstrictive stimuli on the cardiovascular system.

Periotest for measuring periodontal characteristics--correlation with periodontal bone loss

The Periotest measures the reaction of the periodontium to a defined percussive force. The percussion is applied to the tooth by an electronically controlled tapping head. Information on structural change is obtained by measurement of both the elastic and viscous characteristics of the periodontium. The latter prevent oscillations of the tooth in the alveolar bone. A value is calculated and is displayed as a "Periotest value". The following research report shows the relation of Periotest values to bone loss. Bone loss was quantitatively determined for 2312 teeth from orthopantomographic radiographs and for 900 teeth exposed to intra-oral films using the standard paralleling technique. A differentiation was made between vertical and horizontal bone loss. Clinical mobility index, pocket depth, gingival recession and papillary hemorrhagic index were also measured. There was a strong association between the Periotest value and bone loss. These results suggest that Periotest evaluation provides an objective indication of the extent of periodontal bone loss.

Impact of antihypertensive therapy with isradipine and metoprolol on early markers of hypertensive nephropathy

In a double-blind, randomized trial with 26 male white patients with essential hypertension in World Health Organization Stages I and II, we examined the impact of calcium entry blockade (5 to 10 mg/day isradipine, N = 14) and beta-blockade (100 to 200 mg/day metoprolol, N = 12) on early markers of hypertensive nephropathy before and after 7 weeks' treatment. Excretion of total protein, albumin, alpha 1-microglobuline, and N-acetyl-beta-glucosaminidase (NAG) were measured in the 24-h urine by radial immunodiffusion and fluorimetric method, respectively. Before therapy, 8 of 26 patients had microproteinuria (31%), six had microalbuminuria (22%), six had elevated urinary NAG activity (22%), and three had elevated alpha 1-microglobulin excretion (11%). In these subjects anti-hypertensive therapy led to a fall in proteinuria (296 +/- 56 v 127 +/- 116 mg/day, P less than .01), albuminuria (44 +/- 24 v 25 +/- 12 mg/day, P less than .05), and NAG excretion (45 +/- 22 v 28 +/- 5, P less than .05). The higher the pretreatment value, the greater the fall was in proteinuria (r = +0.55, P less than .01), albuminuria (r = 0.80, P less than .001), and NAG excretion (r = 0.60, P less than .01). We did not observe any significant difference in clinical characteristics, blood pressure, or urinary excretion of protein, albumin, or NAG between the two treatment groups, either before or after therapy. Thus, antihypertensive therapy reduced excretion of total protein, albumin, and NAG activity in hypertensive patients with elevated pretreatment values, potentially indicating reversal of early hypertensive nephropathy.(ABSTRACT TRUNCATED AT 250 WORDS)

Head trauma and the risk of Alzheimer's disease

A population-based case-control study of the association between head trauma and Alzheimer's disease was conducted in the Netherlands from 1980 to 1987. The study comprised 198 patients with clinically diagnosed early onset Alzheimer's disease and 198 age- and sex-matched population controls. Adjusted for sex, age, family history of dementia, and education, the odds ratio of a history of head trauma with loss of consciousness was 1.6 (95% confidence interval (CI) 0.8-3.4). The odds ratio for men was 2.5 (95% CI 0.9-7.0), and that for women was 0.9 (95% CI 0.3-2.8). The increase in odds ratio was limited to head trauma that occurred within the period of 10 years prior to the onset of dementia (odds ratio = 10.0; 95% CI 1.0-96.8). There was no evidence of effect modification by family history of dementia as measured on a multiplicative scale. However, the power to show interaction may have been low in this study. The authors' findings are compatible with the view that head trauma may be implicated in Alzheimer's disease, with a short lag time between the head trauma and the first symptoms of disease. The association needs to be confirmed in a prospective follow-up study to fully exclude the possibility of recall bias.