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This study aims to present our surgical technique of lateral lumbar interbody fusion (LLIF) without corpectomy for lumbar vertebral fracture (LVF) associated radiculopathy. This study includes three patients treated with LLIF (mean age of 77.3 years, Group L) and three patients treated with PLIF (mean age of 75.7 years, Group P) to compare the surgical outcomes. The cartilage on the fractured vertebrae was aggressively resected with attention to avoid injury to the ring apophysis. The central cavity of the fractured endplate was filled with a bone graft substitute made of hydroxyapatite and collagen composite, followed by interbody fusion achieved by utilizing of a cage with sufficient length spanning the bilateral edges of the fractured vertebra. PLIF was performed with a standard technique using two interbody cages, and vertebroplasty was combined in one patient. Comparing to PLIF, LLIF could be performed with less estimated blood loss in shorter surgical time. Local kyphotic angle improved in all cases of Group L immediately after the surgery, but correction loss was observed at the final examination. The lordotic angle was lost in Group P postoperatively. Arthrodesis was achieved in all the cases. The mean VAS score for leg pain was 85.3 mm in Group L and 82.0 mm in Group P at preoperation and decreased to 8.7 mm and 11.3 mm, respectively, at postoperation. LLIF is an effective surgical option that enables stabilization of the fractured vertebra and reduces radicular pain by indirect neural decompression.

Objective This retrospective study aimed to compare vertebral endplate cyst formation (VECF), an early predictor for pseudoarthrosis, in different types of interbody cages. Methods We reviewed 84 cases treated with single-level posterior/transforaminal lumbar interbody fusion. We utilized a polyetheretherketone cage in 20 cases (group P), a titanium cage in 16 cases (group Ti), a titanium-coating polyetheretherketone cage in 13 cases (group TiP) and a porous tantalum cage in 35 cases (group Tn). VECF was evaluated comparing the computed tomography scans taken at day 0 and 6-month postoperation. We defined VECF (+) as enlargement of a pre-existing cyst or de novo formation of a cyst with the diameter over 2 mm. We calculated the adjusted odds ratio (OR) and 95% confidence intervals (CIs) as an indicator of association between different types of cages and VECF using a logistic regression model. Results VECF was observed in 13 (65%), 7 (44%), 9 (69%), and 8 (23%) cases in groups P, Ti, TiP and Tn, respectively. VECF correlated with the type of cage (p = 0.04). In comparison with group P, the proportion of VECF (+) cases was lower in group Tn (OR, 0.16; 95% CI, 0.04–0.60) but not different in group Ti (OR, 0.47; 95% CI, 0.10–2.20) and group TiP (OR, 1.06; 95% CI, 0.21–5.28). No patient underwent additional surgery for the fused spinal level during the follow-up periods (average, 37.9 months; range, 6–76 months). Conclusion VECF was the least in the porous Tn cage, suggesting its potential superiority for initial stability.

We describe a 15-year-old girl who developed lumbar disc herniation (LDH) that mimicked discal cyst on magnetic resonance imaging (MRI) after percutaneous endoscopic lumbar discectomy (PELD). She firstly underwent PELD at another hospital for right leg pain caused by L5-S1 level LDH. Her leg pain temporarily relieved, however, the leg pain recurred soon after the surgery. Postoperative T2-weighted MRI showed that the right S1 nerve root was compressed by a round lesion that had an iso-intense wall and highly intense watery content. At that point, postoperative discal cyst was diagnosed, and she underwent PELD again 3 months after the initial surgery. However, the pain persisted after the second surgery, and she came to our hospital. MRI showed that the lesion had remained the same size as compared to the last surgery. Since two times endoscopic surgery was failed, we performed microscopic posterior decompression and found that the lesion actually contained not a cyst but a wet nucleus pulposus, which was different from what we had expected to find. The pain was alleviated immediately after the surgery. As signal intensity on MRI differs depending on the amount of moisture in the LDH, it should be noted that the LDH sometimes looks like a discal cyst on MRI.

The elemental stoichiometry of particulate organic carbon (C), nitrogen (N), and phosphorus (P) connects the C fluxes of biological production to the availability of the limiting nutrients in the ocean. It also influences the marine food-web by modulating zooplankton’s feeding behavior and organic matter decomposition by bacteria. Despite its importance, there is a general paucity of information on how the global C:N:P ratio evolves seasonally and interannually, and large parts of the global ocean remain devoid of observational data. Here, we present a new method combining satellite ocean-color data with a cellular-trait-based model to characterize the spatio-temporal variability of the phytoplankton stoichiometry in the surface mixed layer of the ocean. This new method is demonstrated specifically for the C:P ratio. The approach was applied to phytoplankton growth rates and chlorophyll-to-carbon ratios derived from MODIS-Aqua and maps of temperature-dependent nutrient limitation to generate global and seasonal maps of upper-ocean phytoplankton C:P. Taking it a step further, we determined the C:P of the bulk particulate organic matter, using MODIS-Aqua estimates of particulate organic carbon and phytoplankton biomass. Our results are within 95% confidence interval of available data for both horizontal distributions and time series, indicating our new method’s viability in accurately quantifying seasonally resolved global ocean bulk C:P. We anticipate the new hyperspectral capabilities of the NASA PACE (Plankton, Aerosol, Cloud, ocean Ecosystem) mission will facilitate the determination of phytoplankton stoichiometry for different size classes and further enhance the predictability of marine-ecosystem stoichiometry from space.

In a future warming world, a fully dynamical model of Lake Superior projects that the lake will undergo significant physical and biological changes by the middle of the 21st century with important implications for the surrounding region. Projections for the winter include drastically reduced ice and very weak water column stratification. In contrast, the summertime surface warming is projected to begin earlier, last longer, and be more enhanced. In concert, summertime biological production is projected to shift earlier and become larger. These changes have potentially important consequences for stakeholders with interests in shipping, coastal habitability, fishing, water quality, and recreation. Perhaps more fundamentally, the projected changes imply that Lake Superior may change into a different kind of lake with a dramatically weakened dimictic behavior.

Using a global ocean biogeochemistry model, we examined three drivers of global ocean production C:N:P ratio: flexible phytoplankton stoichiometry, phytoplankton community composition, and regional production shifts. For a middle-of-the-road warming scenario (SSP2), the model predicts a substantial increase in the global export C:P ratio from 113:1 to 119:1 by the year 2100. The most important physiological driver of this stoichiometric change is the effect of the worldwide warming on cyanobacteria, followed by the effect of phosphate depletion on eukaryotes in the Southern Ocean. Also, there is a modest global shift in the phytoplankton community in favor of cyanobacteria at the expense of eukaryotes with a minimal effect on the global production stoichiometry. We find that shifts in the regional production, even in the absence of any change in phytoplankton stoichiometry or taxonomy, can change the global production C:N:P ratio. For example, enhancing the production in the polar waters, which typically have low C:N:P ratios, will have the effect of lowering the global ratio. In our model, the retreat of Antarctic sea ice has this very effect but is offset by production changes downstream and elsewhere. This study thus provides an understanding of how regional production changes can affect the global production C:N:P ratio. However, the current literature indicates substantial uncertainty in the future projections of regional production changes, so it is unclear at this time what their net effect is on the global production C:N:P ratio. Finally, our model predicts that the overall increase in the carbon content of organic matter due to flexible C:N:P ratio helps to stabilize carbon export in the face of reduced nutrient export (i.e. the decrease in C export is ~30% smaller than expected from the decrease in P export by 2100) but has a minimal effect on atmospheric CO _2 uptake (~1%).

Lake Superior's ecosystem includes distinct nearshore and offshore food webs linked by hydrodynamic processes that transport water and tracers along and across shore. The scales over which these processes occur and their sensitivity to increasing summer surface temperatures are not well understood. This study investigated horizontal mixing between nearshore and offshore areas of Lake Superior over the 10-year period from 2003 to 2012 using a realistically forced three-dimensional numerical model and virtual tracers. An age tracer was used to characterize the time scales of horizontal mixing between nearshore areas of the lake where water depth is less than 100 m and deeper areas. The age of water in nearshore areas increased and decreased in an annual cycle corresponding to the lake's dimictic cycle of vertical mixing and stratification. Interannual variability of mixing in the isothermal period was significantly correlated to average springtime wind speed, whereas variability during the stratified season was correlated to the average summer surface temperature. Dispersal of a passive tracer released from nine locations around the model lake's perimeter was more extensive in late summer when stratification was established lakewide than in early summer. The distribution of eddies resolved in the model reflected differences between the early and late summer dispersal patterns. In the eastern part of the lake dispersal was primarily alongshore, reflecting counterclockwise coastal circulation. In the western part of the lake, cross-shore mixing was enhanced by cross-basin currents.

Background: The effect of cardiac pacing on sleep-disordered breathing is controversial. We investigated the long-term effect of cardiac pacing on sleep disordered breathing in patients with conventional indications for permanent pacemakers Methods: Subjects comprised 40 patients (29 men; mean age 69±9 years, mean left ventricle ejection fraction 69±8%, and body mass index 23.6±3.5 kg/m2) who were diagnosed with indications for permanent pacemakers (sick sinus syndrome in 23 patients, atrioventricular block in 15, and brady atrial fibrillation in 2). All patients received polysomnographic evaluations before implantation of permanent pacemakers. After implantation of permanent pacemakers, all patients received polysomnographic evaluations during use of the pacemaker settings (AAI/DDD/VVI at 70 beats per minute). Results: The mean follow-up period was 35±13 months. Before implantation, the distribution of sleep-disordered breathing was as follows: 93% had apnea hypopnea index >5, 58% had apnea hypopnea index >15, and 20% had apnea hypopnea index >30. The mean apnea hypopnea index for all patients was 20±15, for those with obstructive type apnea was 4.9±5.3, and for those with central type apnea was 3.0±4.5. The mean Epworth Sleepiness Score was 5.9±4.0. No patient received continuous positive airway pressure therapy or any other therapy for sleep-disordered breathing during the follow up period. The mean apnea hypopnea index at 1 week after implantation of permanent pacemakers was 21±14 (P=0.8) and the mean apnea hypopnea index at end of follow-up was 11±7 (P

A 60-year-old man with hypertrophic obstructive cardiomyopathy (HOCM) was implanted dual-chamber ICD for the purpose of both the left ventricular outflow tract (LVOT) gradient reduction by ventricular pacing and the primary prevention of ventricular tachyarrhythmia. Because the LVOT gradient reduction and improvement of symptoms by pacing were insufficient, however, a new pacing lead was inserted in the right ventricular apex at a different position 1.5 cm away from the site of the defibrillation lead, and the LVOT gradient greatly declined from 108 to 30 mmHg. This DDD pacing was continued over seven years. On this occasion, he was referred to our hospital because of battery depletion, and a cardiac catheterization study was performed after ICD replacement. The LVOT gradient was 10 mmHg in sinus rhythm. After administration of isoproterenol (0.02γ), the gradient was increased to 92 mmHg in sinus rhythm. DDD pacing using a newly placed ventricular pacing lead significantly decreased the gradient to 36 mmHg. This case study indicated that DDD pacing from a suitable location in the right ventricular apex caused a marked early reduction in the LVOT gradient, and at long-term follow up a further significant effect was obtained, also in sinus rhythm.

The patient was a 64-year-old man with chronic atrial fibrillation with bradycardia. Left ventricular ejection fraction was 34%. He was treated with biventricular pacing. Heart failure improved from NYHA class III to II. Sympathetic nerve activity (SNA. was recorded during 6 minutes of biventricular (BV), right ventricular apical (RVA. and left ventricular (LV. pacing. SNA was significantly lower during biventricular pacing (49.5 ± 4.0/min. compared with RVA (58.8 ±6:9/min, p = 0.016. and LV (63.3 ± 4.3/min, p = 0.002. pacing. BV pacing improves hemodynamics and decreases SNA compared with RVA or LV pacing.

The patient was a 78-year-old man with dilated cardiomyopathy. His cardio-thoracic ratio was 60.4% and left ventricular ejection fraction (LVEF) was 33%. He had been repeatedly admitted for congestive heart failure. He underwent implantation of an implantable cardioverter-defibrillator (ICD) for ventricular fibrillation. We compared the values of BNP and shock impedance stored by the ICD. The correlation coefficient (p-value) between BNP and shock impedance was −0.700 (p < 0.0005), increase of BNP and shock impedance was −0.778 (p < 0.0001), percent increase of BNP and shock impedance was −0.767 (p < 0.0005). In conclusion, there is an inverse relation between BNP and shock impedance, and measurements of shock impedance may be useful in the management of congestive heart failure.