Is the radiographic subsidence of stand-alone cages associated with adverse clinical outcomes after cervical spine fusion? An observational cohort study with 2-year follow-up outcome scoring

Background

The stand-alone treatment of degenerative cervical spine pathologies is a proven method in clinical practice. However, its impact on subsidence, the resulting changes to the profile of the cervical spine and the possible influence of clinical results compared to treatment with additive plate osteosynthesis remain under discussion until present.

Methods

This study was designed as a retrospective observational cohort study to test the hypothesis that radiographic subsidence of cervical cages is not associated with adverse clinical outcomes. 33 cervical segments were treated surgically by ACDF with stand-alone cage in 17 patients (11 female, 6 male), mean age 56 years (33–82 years), and re-examined after eight and twenty-six months (mean) by means of radiology and score assessment (Medical Outcomes Study Short Form (MOS-SF 36), Oswestry Neck Disability Index (ONDI), painDETECT questionnaire and the visual analogue scale (VAS)).

Results

Subsidence was observed in 50.5% of segments (18/33) and 70.6% of patients (12/17). 36.3% of cases of subsidence (12/33) were observed after eight months during mean time of follow-up 1. After 26 months during mean time of follow-up 2, full radiographic fusion was seen in 100%. MOS-SF 36, ONDI and VAS did not show any significant difference between cases with and without subsidence in the two-sample t-test. Only in one type of scoring (painDETECT questionnaire) did a statistically significant difference in t-Test emerge between the two groups (p = 0.03; α = 0.05). However, preoperative painDETECT score differ significantly between patients with subsidence (13.3 falling to 12.6) and patients without subsidence (7.8 dropped to 6.3).

Conclusions

The radiological findings indicated 100% healing after stand-alone treatment with ACDF. Subsidence occurred in 50% of the segments treated. No impact on the clinical results was detected in the medium-term study period.

     

Inflammatory bowel perforation during immune restoration after one year of antiretroviral and antituberculous therapy in an HIV-1-infected patient: report of a case

PURPOSE: This article reports an unusual presentation of bowel perforation. METHODS: We report the case of a 30-year-old HIV-infected male who suffered from an advanced state of CD4 cell depletion (29 CD4 cells per 106/l). Abdominal pain and diarrhea led to further examinations. RESULTS: Colonoscopy revealed a severe tuberculous ileocecal inflammation. Tuberculosis and HIV infection were treated. The patient's response to antiretroviral therapy was excellent. After 11 months of potent antiretroviral treatment and 12 months of antituberculous therapy he suffered from acute abdominal pain with fever and ileus. Laparotomy revealed two intestinal perforations of the jejunum and inflammation of the whole ileocecal region. CONCLUSION: Immunopathologic reactions caused by immune restoration are novel presentations of highly active antiretroviral treatment as shown here. The presented patient is an unusual case with a very late onset of inflammatory response, which led to intestinal perforation.     

A high inorganic phosphate diet perturbs brain growth, alters Akt-ERK signaling, and results in changes in cap-dependent translation.

Inorganic phosphate (Pi) plays a key role in diverse physiological functions. Recently, considerable progress has been made in our understanding of the function and regulation of the brain-specific sodium-dependent inorganic phosphate transporter 1 (NPT1), which is found to exist principally in cerebrum and cerebellum. The potential importance of Pi as a novel signaling molecule and the poor prognosis of diverse neurodegenerative diseases that involve brain-specific NPT1 have prompted us to define the pathways by which Pi affects mouse brain growth. A high phosphate diet caused an increase in serum Pi accompanied by a decrease in calcium, and a decrease in body weight coupled with a decreased relative weight of cerebellum. A high phosphate diet caused a significant increase in protein expression of NPT1, both in cerebrum and cerebellum. Additionally, the high phosphate diet increased Homo sapiens v-akt murine thymoma viral oncogene homolog 1 (Akt) phosphorylation at Ser473 in cerebrum and cerebellum, whereas suppression of Akt phosphorylation at Thr308 was observed only in cerebellum. Selective suppression of eukaryotic translation initiation factor-binding protein (eIF4E-BP1) in cerebrum was induced by high levels of Pi, which induced cap-dependent and cap-independent protein translation in cerebrum and cerebellum, respectively. Phosphorylation of extracellular regulated kinase 1 (ERK1) in comparison with that of ERK2 was significantly reduced in both cerebrum and cerebellum. High levels of Pi reduced protein expressions of proliferating cell nuclear antigen (PCNA) and cyclin D1 in cerebrum and cerebellum. In conclusion, the results indicate that high dietary Pi can perturb normal brain growth, possibly through Akt-ERK signaling in developing mice.     

Oxygen dynamics in the aftermath of the Great Oxidation of Earth’s atmosphere

The oxygen content of Earth’s atmosphere has varied greatly through time, progressing from exceptionally low levels before about 2.3 billion years ago, to much higher levels afterward. In the absence of better information, we usually view the progress in Earth’s oxygenation as a series of steps followed by periods of relative stasis. In contrast to this view, and as reported here, a dynamic evolution of Earth’s oxygenation is recorded in ancient sediments from the Republic of Gabon from between about 2,150 and 2,080 million years ago. The oldest sediments in this sequence were deposited in well-oxygenated deep waters whereas the youngest were deposited in euxinic waters, which were globally extensive. These fluctuations in oxygenation were likely driven by the comings and goings of the Lomagundi carbon isotope excursion, the longest–lived positive δ¹³C excursion in Earth history, generating a huge oxygen source to the atmosphere. As the Lomagundi event waned, the oxygen source became a net oxygen sink as Lomagundi organic matter became oxidized, driving oxygen to low levels; this state may have persisted for 200 million years.Multiple lines of geochemical evidence (1–4) point to a substantial increase in the oxygen content of the atmosphere some 2,300–2,400 million years ago (Ma) in what is known as the “Great Oxidation Event” (GOE) (4). This rise in oxygen occurred during an episode of major glaciation, known as the Huronian glaciation, but the cause of oxygen increase remains elusive. Some have argued that the GOE occurred as a direct result of cyanobacterial evolution (5) whereas others have assumed that cyanobacteria evolved well before the GOE and have looked for causes involving changes in the redox balance of the Earth surface (6–9). In any event, beginning after the GOE, and sometime between 2,300 and 2,230 Ma, there was a large positive excursion in the ¹³C of marine inorganic carbon that was apparently global in nature (10–13). This event is known as the Lomagundi carbon isotope excursion, with δ¹³C values reaching upwards of 12 per mil. The event lasted well over 100 million years, with a termination estimated at between about 2,110 Ma and 2,080 Ma and no later than 2,060 Ma (10, 14). This excursion represents the largest positive carbon-isotope excursion in Earth history.In standard thinking, a large positive carbon-isotope excursion is driven by the enhanced burial of organic carbon into sediments (15, 16). An event as sustained and dramatic as the Lomagundi excursion would seemingly require an unusual driving mechanism, and it has been suggested that the GOE itself may have been the cause through enhanced oxidative weathering on land accompanying the increase in oxygen. This oxidative weathering liberated more phosphorus to the oceans and stimulated primary production and organic carbon burial (17, 18). Organic carbon burial is a source of oxygen to the atmosphere, and it also has been suggested that the Lomagundi excursion may have driven atmospheric oxygen to higher levels than attained during the GOE itself (17, 19). The deposition of massive calcium sulfate deposits during the Lomagundi Event (20–22), indicating elevated seawater sulfate concentrations, would be consistent with this increase in oxygen. Also, the concentrations of uranium in shales deposited in anoxic marine waters during the Lomagundi excursion show enrichment compared with shales deposited both before and after the excursion (23). This observation would indicate higher marine U concentrations, consistent with globally expanded oxic conditions in marine waters. However, when ratioed to total organic carbon (TOC), the biggest U enrichments are found within the Huronian glaciation, during the initiation of the GOE, whereas the enrichments during the Lomagundi excursion are much smaller and quite comparable to those found before the GOE (23) when atmospheric oxygen was much lower in concentration (1, 3). Therefore, there remain some uncertainties in interpreting the U signal.There also have been some suggestions that oxygen fell again to lower levels as the Lomagundi event waned (17, 24, 25). Of particular interest here is an increase in the isotopic composition in δ³⁴S of carbonate associated sulfate (CAS) through the Lomagundi event, which could be taken to indicate an expansion of euxinic conditions (24) as might be expected with falling oxygen levels. However, although consistent with lower levels of ocean oxygenation, this isotope data is not direct evidence, and the CAS results are apparently restricted to sediments deposited during the Lomagundi event (as evidenced by elevated δ¹³C values) and not afterward. Overall, although there are compelling reasons to believe that the Lomagundi excursion, and its aftermath, represented a dynamic period in the history of Earth oxygenation, there is little direct evidence for the state of atmospheric and ocean oxygenation both during and beyond the event. This time window is also represented by the Francevillian Group of Gabon. Here, we explore the nature of marine water-column chemistry during the deposition of these rocks, providing a unique window into the evolution of ocean and atmospheric chemistry during what appears as an exceptionally dynamic period of oxygen evolution in Earth history.