[Diabetic foot syndrome-Part 2 : Revascularization, treatment alternatives, care structures, recurrency prophylaxis]. / Diabetisches Fußsyndrom ­ Teil 2 : Revaskularisation, Behandlungsalternativen, Versorgungsstrukturen, Rezidivprophylaxe.

Diabetic foot syndrome (DFS) is the most frequent reason for major amputations in Germany. The majority of foot lesions are triggered by repetitive pressure in diabetic polyneuropathy. Peripheral arterial occlusive disease (PAOD) impairs wound healing and is the main risk factor for amputations. The treatment of wounds and infections as well as timely revascularization are decisive. The use of endovascular and vascular surgical methods depends on the distribution pattern and length of the occlusion processes. Both procedures are complementary. Bypass surgery is of great importance for neuroischemic DFS. Multidisciplinary centers that provide revascularization in DFS can achieve an improvement of arterial blood flow in 90% of the cases and reduce the amputation rate by up to 80%. Due to the high recurrence rate of diabetic foot lesions, measures for secondary prophylaxis are of exceptional importance (podological and orthopedic technical care, foot surgery).

[Diabetic foot syndrome-Part 1 : Definition, pathophysiology, diagnostics and classification]. / Diabetisches Fußsyndrom ­ Teil 1 : Definition, Pathophysiologie, Diagnostik und Klassifikation.

There are ca. 8 million persons with diabetes mellitus living in Germany. A late sequelae of diabetes is the diabetic foot syndrome (DFS), the prevalence of which is greatly increasing. It comprises all alterations of the foot as a result of diabetic polyneuropathy as well as microvascular and macrovascular (peripheral arterial occlusive disease, PAOD) alterations. Many of the ca. 250,000 newly diagnosed diabetic foot ulcers per year become chronic wounds. Despite intensive efforts for prevention, early diagnosis and adequate wound care, ca. 13,000 persons with diabetes undergo major limb amputation in Germany every year. With consistent treatment in interdisciplinary centers and by exhausting all possible methods of wound treatment, pressure relief as well as arterial revascularization, the major amputation rate in patients with diabetic foot problems can be reduced by 80%. With a suitable strategy of prevention, the recurrence rate of foot ulcers would be reduced.

[New Aspects of Endovascular Treatment for Popliteal Aneurysms: First Results of a Pilot Trial]. / Neue Aspekte der endovaskulären Behandlung des Poplitealaneurysmas: Erste Ergebnisse einer Pilotstudie.

Popliteal aneurysms are the most often diagnosed peripheral aneurysms and are often associated with chronic occlusive disease or acute thrombosis with limb-threatening critical ischaemia. Rupture is a rare event. Due to the immense risk of limb loss, early treatment in the asymptomatic stage is recommended either with surgical bypass, interposition or endovascular means using covered stents. Published data are inconclusive concerning endovascular treatment and implant costs are high. An alternative strategy consists in using flow diverters with optimal material characteristics for use in the popliteal artery, in our study this is represented by a woven nitinol bare metal stent with extreme flexibility and high radial force resistance. In this pilot study 13 aneurysms were treated successfully with promising results after 2 to 23 months follow-up. Technical success was achieved in 100 % with complete aneurysm thrombosis and no perioperative complications such as stent fractures, device migration or separation could be detected. Implant costs were significantly lower compared to those for covered stents. The re-occlusion rate was lower for electively treated patients compared to aneurysms treated in an acute stadium of thrombosis treated with rotational aspiration and thrombolysis. The given results allow us to query the need for complete aneurysm exclusion with covered stents or bypasses.

[Evidence-based recommendations on primary diagnostics of peripheral arterial occlusive disease in geriatric patients]. / Evidenzbasierte Empfehlungen zur Basisdiagnostik der peripheren arteriellen Verschlusskrankheit bei geriatrischen Patienten.

The prevalence of peripheral arterial occlusive disease (PAOD) is high in elderly patients and its clinical manifestation is often atypical. Comorbidity and morbidity as a consequence of PAOD are significant. Therefore, standardized primary diagnostics are required among geriatric patients. Drawn from a search of the literature, evidence-based recommendations are provided. Pulse palpation and the evaluation of a patient's medical history are obligatory components of primary diagnostics, even in the absence of typical symptoms. In the case of pathological and ambiguous findings, measuring Doppler ankle pressures is suggested as the next diagnostic step. Further measures depend on the following factors: the presence of lesions on the leg with disturbed blood flow, predominantly in the foot and lower leg areas, degree of PAOD-related ailments, and, finally, intended surgery of the affected leg for other medical reasons.

[Carotid surgery in regional anesthesia--anesthesiological, neurological and surgical aspects]. / Die Chirurgie der A. carotis in Regionalanästhesie--anästhesiologische, neurologische, chirurgische und ökonomische Aspekte.

Surgery of the carotid artery is justified only if it is performed with low complication rates. The essential advantages of regional anesthesia in comparison to general anesthesia are a secure neuromonitoring, hemodynamic stability and prolonged analgesia. Regional anesthesia for carotid surgery, which is described methodically in this paper, needs only a minor expenditure. Our own data show that patients with a contralateral occlusion of the internal carotid artery and patients with a high risk for surgery (ASA IV) are at a high risk for neurological events during carotid crossclamping. Consequences of regional anesthesia on the surgical procedure are to ignore. The question, whether economic advantages exist for regional anesthesia, cannot yet be answered.

Spirostomum spp. (Ciliophora, Protista), a suitable system for endocytobiosis research.

Among ciliate genera, only Paramecium and Euplotes species have been studied extensively as host organisms of bacterial endocytobionts. In this article, we show that members of the genus Spirostomum may also serve as a suitable system for endocytobiosis research. Two strains of Spirostomum minus (Heterotrichea, Ciliophora) collected in Germany and Italy, respectively, were found to harbor different types of bacterial infections. Bacteria of various sizes and shapes were observed in the cytoplasm or in the nuclei of the ciliates. The bacteria in the cytoplasm were either surrounded by a peribacterial membrane or lay naked. One of the bacterial species was found in the vicinity of the contractile fibrillar system (myonemes) of the ciliates. In rare cases, another type of bacteria was observed associated with mitochondria. The macronuclei of both the Italian and the German strains were crowded with endocytobionts. The endonuclear bacteria in the two S. minus strains differed with respect to their cytoplasmic structures but they were of similar size and both were rod shaped. According to the results of in situ hybridization, the endonuclear bacteria of the Italian strain belong to the subgroup of alphaproteobacteria, whereas the bacteria associated with the fibrillar system appeared to be gram-positive bacteria with high G+C content. While both the German and the Italian strains were found to permanently maintain their endocytobionts, they were at least partly colonized by different bacteria. This is taken as an indication that geographically separated populations of ciliates may be stably infected by different endocytobionts, possibly due to different ecological conditions. For S. minus and S. ambiguum a total of 7 different bacterial endocytobionts have now been recorded. We recommend the members of the genus Spirostomum as a suitable system for endocytobiosis research.

Expression of survivin, YB-1, and KI-67 in sporadic adenomas and dysplasia-associated lesions or masses in ulcerative colitis.

Sporadic adenomas are said to exhibit an orderly growth pattern with a reversal of proliferative and apoptotic cell distribution as compared with normal colonic crypts. Dysplastic polyps of patients with ulcerative colitis (UC) may represent dysplasia-associated lesions or masses (DALM) with a high associated cancer risk, or, alternatively, may represent sporadic adenomas. Histologic criteria to differentiate between sporadic adenomas and DALM have not focused on the balance between cell renewal and cell loss. The expression of the novel anti-apoptosis gene product, survivin, and the proliferation markers, Ki-67 and Y-box binding protein (YB-1), were investigated by immunohistochemical localization in sporadic adenomas and DALM lesions of patients with UC. In adenomas, KI-67 was expressed preponderantly at the luminal aspect of the polyp, whereas its expression was diffuse in DALM. Survivin was detected diffusely in both adenomas and DALM. YB-1 showed positive staining in the deep aspect of adenomatous glands but only to a minor degree at the surface, whereas both deep and diffuse expression patterns of YB-1 were seen in DALM. The authors conclude that DALM and sporadic adenomas exhibit different patterns of cellular proliferation and that molecular markers of cell proliferation, Ki-67 and YB-1, may be useful to distinguish sporadic adenomas from DALM. However, the similar expression of survivin suggests that the underlying mechanisms that regulate apoptotic cell death are uniform in these lesions.

Intracellular bacteria in ciliates.

Ciliates are frequently colonized by other micro-organisms. The large size of ciliate cells offers habitats for hundreds to thousands of bacteria in different compartments, such as cytoplasm, nuclei and even perinuclear spaces. Size, phagocytic feeding habit and other features appear to be favorable pre-adaptations of ciliates for symbiosis with bacteria. Certain intracellular bacteria are permanent symbionts that are not infectious, whereas others are highly infectious. Both types show specific adaptations. With their wide spectrum of phylogenetic positions, intracellular bacteria in ciliates show relationships to different taxa of free-living bacteria and even archaea. Certain symbionts may be deleterious for their host ciliates, whereas others may provide a selective advantage under appropriate conditions or even be essential for the host cells. Depending on the nature of a symbiont, its prevalence in a host population may be low or high. Symbionts that express a killer toxin affecting non-infected ciliates achieve high infection rates in a host population. whereas certain infectious bacteria may only show a low prevalence.

Intra- and intercellular communication systems in ciliates.

Intracellular signaling and cell-cell interactions are basic features of living organisms. Ciliated protozoa show complex mechanisms of intracellular signaling, as is demonstrated for the phagosomal pathway. Although unicellular, ciliates also communicate with other cells, for example, with invading or symbiotic micro-organisms, some of which are dwelling in the nuclei. In predator-prey interactions chemical signals (kairomones) released by certain predators induce defensive morphological or behavioral changes in the prey ciliates. In intercellular communication sensu strictu ciliate cells communicate with each other, for example, in sexual propagation. A variety of sexual signals have been found to function in preconjugant interaction. Many phenomena of cellular communication in ciliates appear to be similar to those found in multicellular organisms.

[Reconstructive surgery of the cavo-ilio-femoral segment in acute occlusion]. / Rekonstruktive Chirurgie des kavoiliofemoralen Segmentes bei akutem Verschluss.

In-between 25 years 105 reconstructions of the cavoiliacal segment have been performed, for malignant disease 37, for fibrotic stenoses of the left common iliac vein 48, additionally in injury and hypoplasia of the caval or iliac veins and in case of thrombosed caval filters. In case of reconstructions of the iuxtarenal caval vein and renal veins (27) a direct suture with or without patch plasty was preferred. Reconstructions of the infrarenal caval vein have been performed by direct suture (16), by graft interposition (9) or bypass (2). Mainly reconstructions using deep veins as an autologous graft are preferred. Most operations have been performed in order to reconstruct the iliac veins (70). Endovascular procedures such as dilatation with or without stenting (35) offer an excellent palliation in tumour disease, however, results are poor in treatment of fibrotic stenoses of the left common iliac vein. Better results can be achieved by cross-over-bypasses (30), especially when using a superficial femoral vein graft.

Intracellular bacteria in protozoa.

Intracellular bacteria in humans are typically detrimental, and such infections are regarded by the patients as accidental and abnormal. In protozoa it seems obvious that many bacteria have coevolved with their hosts and are well adapted to the intracellular way of life. Manifold interactions between hosts and intracellular bacteria are found, and examples of antibacterial resistance of unknown mechanisms are observed. The wide diversity of intracellular bacteria in protozoa has become particularly obvious since they have begun to be classified by molecular techniques. Some of the bacteria are closely related to pathogens; others are responsible for the production of toxins.

Superficial femoral vein in arterial reconstruction for limb salvage: outcome and fate of venous circulation.

BACKGROUND: In some particular cases in vascular surgery it is mandatory to perform arterial reconstruction using autologous graft. Since 1985, we have been using the superficial femoral vein for arterial substitute in the case of limb salvage, when another autologous vein has not been available. We made a prospective investigation on 32 patients over a mean period of 24.5+/-12.1 months (1 to 48 months) to evaluate the usefulness of superficial femoral vein (SFV) for distal arterial reconstructive surgery and to objectify the fate of venous circulation of the limb after removal of this vein. METHODS: There were 20 male and 12 female patients averaging 64.3+/-10.3 years, who underwent crural arterial reconstructive surgery using the composite technique (PTFE and SFV). All grafts had been placed subcutaneously in lateral to knee position. Mean length of removed superficial femoral vein was 13.2+/-9.4 cm. RESULTS: In 6 patients (18.7%), we found an early occlusion of bypass followed by major amputation in 5 cases (15.6%). Minor amputation had to be done in 12 patients (37.5%). Cumulative patency was 56.3% after 48 months. Following the removal of superficial femoral vein, we had no complications due to venous stasis. We found a significant increase of plethysmographically measured venous capacity (1.7+/-0.49 to 2.51+/-0.71 [p<0.01]) and venous outflow (14.9+/-5.34 to 23.9+/-10.4 [p<0.05]) after 7.7 months. We did not observe more significant changes of venous circulation during further follow-up. CONCLUSIONS: Despite overall good results, we only recommend the use of superficial femoral vein in hazardous situations, when other autologous material is not available.

Bacteria of the Genus Roseobacter Associated with the Toxic Dinoflagellate Prorocentrum lima.

The dinoflagellate Prorocentrum lima is known to produce diarrhetic shellfish poisons. However, it is yet unclear if the dinoflagellates themselves or the bacteria associated with them produce the toxins. Here we analyze the toxicity as well as the spectrum of bacteria in two cultures of P. lima, namely P. lima-SY and P. lima-ST, which initially derived from the same P. lima strain PL2V. Toxicity tests, applying the Artemia bioassay revealed in both cultures high levels of toxins. The bacteria, associated with the two cultures, were identified by PCR/nucleotide sequence analysis of the 16S rRNA gene. From cultures of P. lima-SY the dominant sequence was found to share a 93.7% similarity with the sequence of Roseobacter algocolus [R. algicola]; the relative abundance was determined to be 83%. In addition three further sequences of bacteria, grouped to the α-Protobacteria have been identified: Paracoccus denitrificans [90.8%], R. algocolus [94.4%] and Rhizobium huakuii [92.6%]. The identification of bacteria in P. lima-ST revealed that most share highest similarity with Bartonella taylorii but with a relatively low score of 87%. In addition to this sequence, two sequences with high similarity to the genus Roseobacter were obtained. The other sequences identified have not been detected in P. lima-SY. Studies with pure bacterial strains, previously isolated from a culture of P. lima-ST and subsequently cultured on agar plates, revealed that none of them was identical to those identified in the dinoflagellate culture itself. An explanation for the change of the spectrum of bacteria in the different cultures can only be expected when axenic cultures from P. lima are available.

Occurrence of fragmented 16S rRNA in an obligate bacterial endosymbiont of Paramecium caudatum.

The phylogenetic position of Caedibacter caryophila, a so far noncultured killer symbiont of Paramecium caudatum, was elucidated by comparative sequence analysis of in vitro amplified 16S rRNA genes (rDNA). C. caryophila is a member of the alpha subclass of the Proteobacteria phylum. Within this subclass C. caryophila is moderately related to Holospora obtusa, which is another obligate endosymbiont of Paramecium caudatum, and to Rickettsia. A 16S rRNA targeted specific hybridization probe was designed and used for in situ detection of C. caryophila within its host cell. Comparison of the 16S rDNA primary structure of C. caryophila with homologous sequences from other bacteria revealed an unusual insertion of 194 base pairs within the 5'-terminal part of the corresponding gene. The intervening sequence is not present in mature 16S rRNA of C. caryophila. It was demonstrated that C. caryophila contained fragmented 16S rRNA.

Computed tomographic enhancement of the liver, liver abscesses, spleen, and major vessels with perfluorooctylbromide emulsion. Influence of dosage and injection velocity in an animal model.

RATIONALE AND OBJECTIVES: Computed tomographic (CT) enhancement of the liver, liver abscess, spleen, and major vessels was investigated between 2 and 48 hours after intravenous administration of perfluorooctylbromide (PFOB emulsion) in an animal model of 63 rabbits. METHODS: Twenty-one animals received 3 g/kg PFOB as a fast bolus injection. Using a slow infusion rate, the same number of animals received either the same dose (3 g/kg) or half the dose (1.5 g/kg). RESULTS: Vascular enhancement was best after bolus injection of 3 g/kg emulsion. The density peak occurred after 2 hours. A continuous enhancement of approximately 100 Hounsfield units (HU) was observed up to 24 hours in the animals receiving 3 g/kg, independent of the injection velocity. A density peak of 70 HU was found 2 hours after the infusion of 1.5 g/kg. The density peak of the liver, the spleen, and the abscess wall was observed 48 hours after emulsion administration in all groups receiving 3 g/kg. The peak was approximately 150 HU for the liver, 400 HU for the spleen, and 150 HU for the abscess wall. In animals receiving only 1.5 g/kg perflubron, the peak density of the abscess wall was 132 HU after 12 hours, approximately 80 HU for the liver between 2 and 48 hours, and approximately 280 HU after 48 hours for the spleen. CONCLUSIONS: PFOB emulsion produces the highest vascular enhancement within the first 2 hours after the bolus injection of 3 g/kg. For spleen and abscess wall imaging, even the relatively low dose of 1.5 g/kg produced a satisfactory enhancement level for a significant length of time, whereas liver enhancement was best after administration of the higher dose.

Identification and localization of major stage-specific polypeptides of infectious Holospora obtusa with monoclonal antibodies.

With the help of monoclonal antibodies (MAbs) we investigated the occurrence of six polypeptides throughout parts of the life cycle of Holospora obtusa, a bacterium infecting the macronucleus of the ciliate Paramecium caudatum. The polypeptides of interest formed major bands in the protein pattern of the infectious form (IF) of H. obtusa. All MAbs used recognized individual polypeptide bands of the IF proteins separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Three polypeptides were also detected in the reproductive form in trace amounts. Two-dimensional electrophoresis revealed that the 33,000-, 28,000-, and 14,000-Mr polypeptides wre acidic and exhibited multiple isoelectric points under native conditions. Four polypeptides (Mrs of 50,000, 33,000, 28,000, and 20,000) were no longer detected or became drastically reduced within the first 30 min of invasion. Concomitantly, a loss of electron-dense periplasmic material occurred, which is typical for invading IFs (H.-D. Görtz and M. Wiemann, J. Protistol. 24:101-109, 1989). In an attempt to clarify the subcellular localization of the six polypeptides, we performed chloroform extraction studies and identified four of the released polypeptides with MAbs. A 14,000-Mr polypeptide was immunocytochemically localized in the periplasm of the IF. The results showed that the six major polypeptides of the IF were stage specific or stage specifically enriched and are likely to contribute to the electron-dense periplasmic material of the IF.

Identification in situ and phylogeny of uncultured bacterial endosymbionts.

The use of Koch's technique to isolate bacteria in pure cultures has enabled thousands of bacterial species to be characterized. But for the many microorganisms that have never been cultivated, DNA amplification in vitro using the polymerase chain reaction is now making their genes accessible. Here we use this technique to study bacteria of the genus Holospora, which live in ciliates and whose phylogenetic relationship has remained unknown because they are impossible to cultivate. Species of Holospora are highly infectious and live in the nuclei of their specific host cells: H. elegans and H. undulata infect micronuclei of Paramecium caudatum, whereas H. obtusa infects the macronucleus in other strains of the same host species; Holospora species have a common developmental cycle. We have amplified, cloned and sequenced gene fragments encoding ribosomal RNA of H. obtusa. The phylogenetic position of H. obtusa in the alpha group of Proteobacteria was determined by 16S rRNA sequence analysis. The sequences were then used to design species- as well as genus-specific rRNA hybridization probes, which enabled us to detect and differentiate individual cells of the endosymbionts in situ. The large amount of rRNA in the cells indicates a high physiological activity of the endosymbionts in the host nuclei.

Changes in fine structure and polypeptide pattern during development of Holospora obtusa, a bacterium infecting the macronucleus of Paramecium caudatum.

The development of the bacterium Holospora obtusa, which infects the macronucleus of Paramecium caudatum, was investigated in the course of a new infection from the infectious form into the reproductive form and vice versa. In parallel with a complete structural reorganization of the bacterium, the protein pattern changed gradually in this development. During the differentiation of the infectious form into the reproductive form, the voluminous periplasm was gradually reduced and the cytoplasm expanded, until the entire bacterium was filled by the cytoplasm. At this stage the long cell divided into five to seven short cells and thereby established the reproductive form, the main stage of the bacterium being maintained and multiplying in the host nucleus. In parallel with the reduction of the periplasm, some of the main proteins of the infectious form gradually disappeared in the electrophoresis pattern; some proteins disappeared earlier than others. Simultaneously, other proteins appeared and gradually became more prominent in the pattern of the developing reproductive form. In the reverse development, when the reproductive form differentiated into the infectious form, the bacterium grew longer, the cytoplasm was condensed, and electron-dense material was deposited in the extending periplasmic space. In parallel with this morphological development, the polypeptide pattern reverted to that of the infectious form.

Route of infection of the bacteria Holospora elegans and Holospora obtusa into the nuclei of Paramecium caudatum.

The route of infection of two endonucleobiotic bacteria in Paramecium caudatum was investigated with the electron microscope. The bacterium Holospora elegans specifically infects the micronucleus, whereas Holospora obtusa infects the macronucleus. The infectious forms of both bacteria are ingested by the prospective host cell into a phagosome. The bacteria leave the phagosome without destroying its membrane. During their transport to the nuclei the bacteria remain surrounded by host membranes forming a transport vesicle. The outer membrane of the bacteria and the vesicle membrane become connected by fibrillar material. Eventually, the transport vesicles are encircled in addition by flat vesicles, which sometimes appear to be part of the endoplasmic reticulum. Later, membranes surrounding the bacterium in the host cytoplasm fuse with the membranes of the nuclear envelope and the bacterium is sluiced into the nucleus. As an alternative mode the infecting bacteria leave their transport-vesicles before invading the nucleus and seem to penetrate the nuclear envelope directly. Inside the nucleus chromatin granules immediately adhere to the bacterial surface. Later a dense layer of chromatin is formed around the endonucleobiotic bacterium.

Release of the endonucleobiotic bacterium Holospora elegans from its host cell Paramecium caudatum.

The endonucleobiotic bacterium Holospora elegans inhabits the micronucleus of Paramecium caudatum. In this paper the release of the infectious form (IF) of H. elegans from its host is described. During the anaphase of the micronuclear division most of the IFs remain within the connecting piece which, therefore, may become enormously distended. In the course of the cytokinesis of the host cell the connecting piece is usually positioned in one half of the dividing cell. Long time observations with the LM combined with EM studies revealed that the connecting piece bursts shortly after cytokinesis and thus releases the IFs into the cytoplasm. The IFs are initially not surrounded by host membranes, but thirty min later all of them are enclosed by one or two host membranes. The IF containing vesicles were never observed to accumulate acridine orange or neutral red and are, therefore, supposed not to become acidified. The release of the IFs by exocytosis via the cytoproct starts about 30 min after cytokinesis and is usually finished another 30 min later. The bacterial fine structure remains unchanged during the course of release.