Heterotope Ossifikation: Von der Ätiologie zur aktuellen Therapie

Zusammenfassung: Heterotope Ossifikationen werden als abnorme Bildung von Knochen in Weichteilgeweben definiert. Man unterscheidet die erworbene von den angeborenen Formen. Die erworbene Form, deren Pathogenese weitgehend ungeklärt ist, wird häufig bei Patienten mit Schädel-Hirn-Trauma, Rückenmarkverletzung, Trauma des Bewegungsapparats oder nach Verbrennungen beobachtet. Klinisch präsentieren sich die heterotopen Ossifikationen häufig symptomfrei, im Initialstadium mit unspezifischen Symptomen, ausgeprägte Formen können jedoch zu schwerwiegenden Funktionseinschränkungen führen. Zur Diagnosesicherung wird insbesondere die Knochenszintigraphie verwendet. Lokale Bestrahlung und nichtsteroidale Antiphlogistika bilden die klassischen Therapie- und Prophylaxeoptionen. In fortgeschrittenen Stadien kann eine chirurgische Resektion notwendig sei

Conserved stromal-immune cell circuits secure B cell homeostasis and function

B cell zone reticular cells (BRCs) form stable microenvironments that direct efficient humoral immunity with B cell priming and memory maintenance being orchestrated across lymphoid organs. However, a comprehensive understanding of systemic humoral immunity is hampered by the lack of knowledge of global BRC sustenance, function and major pathways controlling BRC-immune cell interactions. Here we dissected the BRC landscape and immune cell interactome in human and murine lymphoid organs. In addition to the major BRC subsets underpinning the follicle, including follicular dendritic cells, PI16$^{+}$ RCs were present across organs and species. As well as BRC-produced niche factors, immune cell-driven BRC differentiation and activation programs governed the convergence of shared BRC subsets, overwriting tissue-specific gene signatures. Our data reveal that a canonical set of immune cell-provided cues enforce bidirectional signaling programs that sustain functional BRC niches across lymphoid organs and species, thereby securing efficient humoral immunity

Troublesome Heterotopic Ossification after Central Nervous System Damage: A Survey of 570 Surgeries

BACKGROUND: Heterotopic ossification (HO) is a frequent complication after central nervous system (CNS) damage but has seldom been studied. We aimed to investigate features of HO for the first time in a large sample and the rate of early recurrence of HO in terms of the time of surgery. METHODOLOGY/PRINCIPAL FINDINGS: We retrospectively analyzed data from an anonymous prospective survey of patients undergoing surgery between May 1993 and November 2009 in our institution for troublesome HO related to acquired neurological disease. Demographic and HO characteristics and neurological etiologies were recorded. For 357 consecutive patients, we collected data on 539 first surgeries for HO (129 surgeries for multiple sites). During the follow-up, recurrences requiring another surgery appeared in 31 cases (5.8% [31/539]; 95% confidence interval [CI]: 3.8%-7.8%; 27 patients). Most HO requiring surgery occurred after traumatic brain injury (199 patients [55.7%]), then spinal cord injury (86 [24.0%]), stroke (42 [11.8%]) and cerebral anoxia (30 [8.6%]). The hip was the primary site of HO (328 [60.9%]), then the elbow (115 [21.3%]), knee (77 [14.3%]) and shoulder (19 [3.5%]). For all patients, 181 of the surgeries were performed within the first year after the CNS damage, without recurrence of HO. Recurrence was not associated with etiology (p = 0.46), sex (p = 1.00), age at CNS damage (p = 0.2), multisite localization (p = 0.34), or delay to surgery (p = 0.7). CONCLUSIONS/SIGNIFICANCE: In patients with CNS damage, troublesome HO and recurrence occurs most frequently after traumatic brain injury and appears frequently in the hip and elbow. Early surgery for HO is not a factor of recurrence

Lipopolysaccharide inhibits or accelerates biomedical titanium corrosion depending on environmental acidity

Titanium and its alloys are routinely used as biomedical implants and are usually considered to be corrosion resistant under physiological conditions. However, during inflammation, chemical modifications of the peri-implant environment including acidification occur. In addition certain biomolecules including lipopolysaccharide (LPS), a component of Gram-negative bacterial cell walls and driver of inflammation have been shown to interact strongly with Ti and modify its corrosion resistance. Gram-negative microbes are abundant in biofilms which form on dental implants. The objective was to investigate the influence of LPS on the corrosion properties of relevant biomedical Ti substrates as a function of environmental acidity. Inductively coupled plasma mass spectrometry was used to quantify Ti dissolution following immersion testing in physiological saline for three common biomedical grades of Ti (ASTM Grade 2, Grade 4 and Grade 5). Complementary electrochemical tests including anodic and cathodic polarisation experiments and potentiostatic measurements were also conducted. All three Ti alloys were observed to behave similarly and ion release was sensitive to pH of the immersion solution. However, LPS significantly inhibited Ti release under the most acidic conditions (pH 2), which may develop in localized corrosion sites, but promoted dissolution at pH 4–7, which would be more commonly encountered physiologically. The observed pattern of sensitivity to environmental acidity of the effect of LPS on Ti corrosion has not previously been reported. LPS is found extensively on the surfaces of skin and mucosal penetrating Ti implants and the findings are therefore relevant when considering the chemical stability of Ti implant surfaces in vivo

Assessment of the genetic risks of a metallic alloy used in medical implants

The use of artificial implants provides a palliative or permanent solution for individuals who have lost some bodily function through disease, an accident or natural wear. This functional loss can be compensated for by the use of medical devices produced from special biomaterials. Titanium alloy (Ti-6Al-4V) is a well-established primary metallic biomaterial for orthopedic implants, but the toxicity of the chemical components of this alloy has become an issue of concern. In this work, we used the MTT assay and micronucleus assay to examine the cytotoxicity and genotoxicity, respectively, of an extract obtained from this alloy. The MTT assay indicated that the mitochondrial activity and cell viability of CHO-K1 cells were unaffected by exposure to the extract. However, the micronucleus assay revealed DNA damage and an increase in micronucleus frequency at all of the concentrations tested. These results show that ions released from Ti-6Al-4V alloy can cause DNA and nuclear damage and reinforce the importance of assessing the safety of metallic medical devices constructed from biomaterials

Thrombose der Vena cava inferior nach diagnostischer Laparoskopie

HISTORY AND FINDINGS: A previously healthy 43-year-old woman was admitted because of pain in the lower abdomen. Abdominal and transvaginal ultrasound revealed a cystic structure in the right ovary, providing the indication for an exploratory laparoscopy. A hemorrhagic corpus luteum was enucleated. Laboratory tests had merely shown a raised C-reactive protein level and marginally elevated leukocytes. A family history of thrombotic episodes had been elicited. FURTHER COURSE, DIAGNOSIS AND TREATMENT: Although heparin had been applied increasing swelling developed in both thighs and lower legs at day six, indicating thrombosis of the inferior vena cava. Laboratory tests revealed a mutation in factor V (Leiden). Computed tomography showed complete thrombotic IVC occlusion. Thrombolytic treatment with recombinant tissue plasminogen was initiated, direct thrombus aspiration attempted and a filter inserted in the IVC. Low molecular heparin was infused, replaced by oral anticoagulation with phenprocoumon. Subsequent Doppler ultrasound examination demonstrated almost complete resolution of the thrombus, except for a few small residual thrombi. CONCLUSION: This case demonstrates that even minor laparoscopic interventions carry the risk of an IVC thrombosis as a late complication, indicating appropriate measures to prevent thrombosis. Georg Thieme Verlag KG Stuttgart · New York. Zusammenfassung: Anamnese und Befunde: Bei einer 43-jährigen, bislang gesunden Frau erfolgte wegen akuter Unterbauchschmerzen und sonographisch zystischer Struktur im Bereich des rechten Ovars eine explorative Laparoskopie. Dabei wurde ein hämorrhagisches Corpus luteum enukleiert. Laborchemisch zeigten sich lediglich ein leicht erhöhtes CRP sowie grenzwertig erhöhte Leukozyten. Auffällig war eine positive Familienanamnese für thrombotische Ereignisse. Verlauf, Diagnose und Therapie: Trotz Thromboseprophylaxe kam es am sechsten postoperativen Tag zu zunehmenden Schmerzen in beiden Oberschenkeln sowie Schwellung beider Beine. Im Computertomogramm zeigte sich ein kompletter thrombotischen Verschluss der Vena cava inferior. Untersuchungen hinsichtlich eines genetischen Gerinnungsdefektes offenbarten eine Faktor-V-Leiden-Mutation. Nach Diagnose einer Vena-cava-inferior-Thrombose wurde oberhalb des Thrombus ein Cava-Schirm sowie eine Thrombolyse eingeleitet. Eine am fünften Tag nach Therapiebeginn durchgeführte sonographische Duplexuntersuchung zeigte bis auf wenige kleine Restthrombosen der infrarenalen Abschnitte eine nahezu komplette Auflösung des Thrombus. Folgerung: Nach großen bauchchirurgischen Eingriffen gelten Thrombosen der Vena cava inferior als mögliche Spätkomplikation. Der vorliegende Fall zeigt allerdings, dass auch nach kleinen laparoskopischen Eingriffen die Gefahr der Entwicklung einer entsprechenden Thrombose besteht und eine Prophylaxe unerlässlich ist. Abstract History and findings: A previously healthy 43-year-old woman was admitted because of pain in the lower abdomen. Abdominal and transvaginal ultrasound revealed a cystic structure in the right ovary, providing the indication for an exploratory laparoscopy. A hemorrhagic corpus luteum was enucleated. Laboratory tests had merely shown a raised C-reactive protein level and marginally elevated leukocytes. A family history of thrombotic episodes had been elicited. Further course, diagnosis and treatment: Although heparin had been applied increasing swelling developed in both thighs and lower legs at day six, indicating thrombosis of the inferior vena cava. Laboratory tests revealed a mutation in factor V (Leiden). Computed tomography showed complete thrombotic IVC occlusion. Thrombolytic treatment with recombinant tissue plasminogen was initiated, direct thrombus aspiration attempted and a filter inserted in the IVC. Low molecular heparin was infused, replaced by oral anticoagulation with phenprocoumon. Subsequent Doppler ultrasound examination demonstrated almost complete resolution of the thrombus, except for a few small residual thrombi. Conclusion: This case demonstrates that even minor laparoscopic interventions carry the risk of an IVC thrombosis as a late complication, indicating appropriate measures to prevent thrombosis

Liver packing for complex injuries

Trauma Surger