Acute Deltoid Injury in Ankle Fractures: A Biomechanical Analysis of Different Repair Constructs

BACKGROUND

The importance of the deltoid ligament in the congruency and coupling of the tibiotalar joint is well known. The current trend is to repair it in cases of acute injuries in the context of ankle fractures; however, there is limited information on how it should be reconstructed. The objective of this study was to compare different deltoid ligament repair types in an ankle fracture cadaveric model.

METHODS

Sixteen cadaveric foot-ankle-distal tibia specimens were used. All samples were prepared as a supination external rotation ankle fracture model. Axial load and cyclic axial rotations were applied on every specimen using a specifically designed frame. This test was performed without deltoid injury, with deltoid injury, and after repair. The reconstruction was performed in 4 different ways (anterior, posterior, middle, and combined). Medial clear space (MCS) was measured for each condition on simulated weightbearing (WB) and gravity stress (GS) radiographs. Reflective markers were used in tibia and talus, registering the kinematics through a motion analysis system to record the tibiotalar uncoupling.

RESULTS

After deltoid damage, in all cases the MCS increased significantly on GS radiographs, but there was no increase in the MCS on WB radiographs. After repair, in all cases, the MCS was normalized. Kinematically, after deltoid damage, the tibiotalar uncoupling increased significantly. All isolated repairs achieved a similar tibiotalar uncoupling value as its baseline condition. The combined repair resulted in a significant decrease in tibiotalar uncoupling.

CONCLUSION

Our results show that deltoid repair recovers the tibiotalar coupling mechanism in an ankle fracture model. Isolated deltoid repairs recovered baseline MCS and tibiotalar uncoupling values. Combined repairs may lead to overconstraint, which could lead to postoperative stiffness. Clinical studies are needed to prove these results and show clinically improved outcomes.

CLINICAL RELEVANCE

This study helps in finding the optimum deltoid repair to use in an acute trauma setting.

Adaptation culturally and linguistically to the Chilean population and validation the Dry Eye Questionnaire 5

BACKGROUND AND OBJECTIVE

There are different methods for evaluating dry eye disease (DID), including questionnaires that analyze different aspects of its symptoms, which are important for its better understanding and therapeutic management. The Dry Eye Questionnaire 5 (DEQ-5), is unique in its kind, because in addition to its simplicity, it measures symptoms in 4 dimensions. the aim of this study is to adapt culturally and linguistically and validate this instrument to the Chilean population.

MATERIAL AND METHODS

for the adaptation, the translation and retro-translation of the original version was carried out, its linguistic analysis, the pilot test and the expert panel review (which included a linguistics specialist) were used. For the validation, a psychometric analysis of reliability and validity of the construct was incorporated. The sample in which it was validated was constituted by 205 people with dry eye disease.

RESULTS

141 (69%) of the respondents were women, the mean of age was 48 years ± 16,7, and the median of the total score DEQ-5 was 13 points (R.I 8 - 15 points). The adapted version resulted in a Cronbach alpha of 0.8085, scoring that classified it as good.

DISCUSSION

the questionnaire DEQ-5, which was adapted and validated, was a good instrument to be used in populations with similar characteristics of those in the study. More so, the factor analysis enriched comprehension of the way in which people with dry eye disease relate their symptoms and which questions relate more between them, representing in a better way the aspects evaluated of the symptomatology of this disease.

Dry eye is matched by increased intrasubject variability in tear osmolarity as confirmed by machine learning approach

OBJECTIVE

Because of high variability, tear film osmolarity measures have been questioned in dry eye assessment. Understanding the origin of such variability would aid data interpretation. This study aims to evaluate osmolarity variability in a clinical setting.

MATERIAL AND METHODS

Twenty dry eyes and 20 control patients were evaluated. Three consecutive osmolarity measurements per eye at 5min intervals were obtained. Variability was represented by the difference between both extreme readings per eye. Machine learning techniques were used to quantify discrimination capacity of tear osmolarity for dry eye.

RESULTS

Mean osmolarities in the control and dry eye groups were 295.1±7.3mOsm/L and 300.6±11.2mOsm/L, respectively (P=.004). Osmolarity variabilities were 7.5±3.6mOsm/L and 16.7±11.9mOsm/L, for the control and dry eye groups, respectively (P<.001). Based on osmolarity, a logistic classifier showed an 85% classification accuracy.

CONCLUSIONS

In the clinical setting, both mean osmolarity and osmolarity variability in the dry eye group were significantly higher than in the control group. Machine learning techniques showed good classification accuracy. It is concluded that higher variability of tear osmolarity is a dry eye feature.

The promoter effect of Co on the catalytic activity of the Cu oxide active phase supported on Al2O3 in the hydrogenolysis of glycerol

The CuCo₂O₄ species formed by CoO addition on CuO/Al₂O₃ had a beneficial effect on the catalytic activity in the hydrogenolysis of glycerol.

Sorption of Cr(III) and Cr(VI) to K2Mn4O9 nanomaterial a Study of the effect of pH, time, temperature and interferences

A Rancieite type material (K₂Mn₄O₉) nanomaterial was synthesized and tested for the removal of chromium (III) and chromium (VI) from aqueous solutions. The synthesized nanomaterial was characterized using powder XRD and SEM. XRD showed weak diffraction peaks at only at the angles associated with K₂Mn₄O₉. The SEM corroborated that the nanoparticles were present; however, the nanoparticles were clustered into larger aggregates. Batch studies were performed to determine the optimum pH, capacity, time dependency, interferences, and the thermodynamics of the binding. The optimum pH for the binding of Cr(III) and Cr(VI) were determined to be pH 5 and pH 2, respectively. Isotherm studies were performed at temperatures of 4 , 25 , and 45 for Cr(III) and Cr(VI) and showed binding capacities of 21.7 mg/g, 36.5 mg/g, 41.8 mg/g for Cr(III). The Cr(VI) binding capacities were 4.22 mg/g, 4.08 mg/g, and 3.25 mg/g at the respective temperatures. The thermodynamic studies showed that the binding processes for the reactions were spontaneous and endothermic, with a ΔH was 17.54 kJ/mol for Cr(III) and 6.05 kJ/mol for Cr(VI). The of sorption for Cr(III) were determined to be -3.88 kJ/mol, -5.83 kJ/mol and -7.03 kJ/mol at the aforementioned temperatures. The ΔG values for the Cr(VI) sorption were determined to be -4.89 kJ/mol, -5.64 kJ/mol, and -6.05 kJ/mol. In addition, the ΔS values for Cr(III) and Cr(VI) were determined to be 77.92 J/mol and 39.49 J/mol, respectively. The thermodynamics indicate that the binding of Cr(III) and Cr(VI) is spontaneous and endothermic.

Daniel Alcides Carrión: la teoría unicista

<p>La enfermedad de Carrión presenta clásicamente dos fases clínicas: la fiebre de la Oroya y la verruga peruana. La teoría unicista reconoce que ambas formas clínicas pertenecen a la misma enfermedad, la obtención de este conocimiento representó un duro desafío para la ciencia peruana y mundial. A través de un histórico experimento en 1885, Daniel Alcides Carrión obtuvo la evidencia clínica-experimental que sentó las bases de la teoría unicista; el científico diseñó esta teoría solo hasta las horas finales de su experimento, por lo cual su hallazgo es considerado un acto de serendipia. La demostración bacteriológica de la teoría la realizaría Hideyo Noguchi en 1926; Carrión brindó además evidencia de la transmisibilidad de esta infección y debido a este aporte científico se convirtió en el símbolo de la medicina peruana.</p>

The Porphyromonas gingivalis O antigen is required for inhibition of apoptosis in gingival epithelial cells following bacterial infection

BACKGROUND AND OBJECTIVE

Porphyromonas gingivalis infection induces apoptosis inhibition in gingival epithelial cells; however, it is not fully understood which bacterial effectors are involved in this process. The aim of this study is to evaluate whether the P. gingivalis lipopolysaccharide (LPS), specifically the O-antigen region, affects adherence, invasion, viability and apoptosis of gingival epithelial cells.

MATERIAL AND METHODS

Gingival epithelial cells (OKF6/TERT2 line) were infected by different freshly prepared P. gingivalis clinical isolates, obtained from subjects with chronic periodontitis (CP3 and CP4) and healthy individuals (H1 and H3). Periodontitis and healthy isolates show differences in O-antigen production, as healthy isolates lack the O-antigen region. In addition, cells were infected by a site-specific mutant lacking the O-antigen portion. After 24 h postinfection, cell proliferation, viability and apoptosis were evaluated by Trypan blue, MTS and annexin V assays, respectively. Bacterial invasion, adhesion and proliferation were measured by gentamicin/metronidazole protection assays. Finally, toll-like receptor (TLR)2 and TLR4 mRNA expression was evaluated by quantitative reverse transcription-polymerase chain reaction. Statistical analysis was performed using ANOVA, Tukey's or Dunnett's tests (p < 0.05).

RESULTS

At 24 h postinfection, strains lacking the O-antigen region (healthy isolates and O-antigen ligase-deficient strain) were unable to increase proliferation and viability, or decrease apoptosis as compared with strains producing intact LPS (periodontitis isolates and reference strain). However, the presence of the O-antigen neither contributed to changes in the ability of the bacteria to adhere to or invade cells, nor to intracellular survival. The presence of O-antigen also increased the expression of TLR4 (nearly sixfold), which correlated with inhibition of apoptosis.

CONCLUSION

The O-antigen region of P. gingivalis LPS is required to increase gingival epithelial cell viability upon infection by bacteria and this increase is attributable to a reduction in apoptosis. Moreover, although bacterial internalization is required, the effects observed are not due to alterations in P. gingivalis adherence, invasion or intracellular survival. Interestingly, inhibition of apoptosis correlates with increased TLR4 expression, suggesting a role for TLR4 in this process.

The sensitivity of tropical leaf litter decomposition to temperature: results from a large-scale leaf translocation experiment along an elevation gradient in Peruvian forests

• We present the results from a litter translocation experiment along a 2800-m elevation gradient in Peruvian tropical forests. The understanding of the environmental factors controlling litter decomposition is important in the description of the carbon and nutrient cycles of tropical ecosystems, and in predicting their response to long-term increases in temperature. • Samples of litter from 15 species were transplanted across all five sites in the study, and decomposition was tracked over 448 d. • Species' type had a large influence on the decomposition rate (k), most probably through its influence on leaf quality and morphology. When samples were pooled across species and elevations, soil temperature explained 95% of the variation in the decomposition rate, but no direct relationship was observed with either soil moisture or rainfall. The sensitivity of the decay rate to temperature (κ(T)) varied seven-fold across species, between 0.024 and 0.169 °C⁻¹, with a mean value of 0.118 ± 0.009 °C⁻¹ (SE). This is equivalent to a temperature sensitivity parameter (Q₁₀) for litter decay of 3.06 ± 0.28, higher than that frequently assumed for heterotrophic processes. • Our results suggest that the warming of approx. 0.9 °C experienced in the region in recent decades may have increased decomposition and nutrient mineralization rates by c. 10%.

[Regional cerebral blood flow changes in Parkinson's disease: correlation with disease duration]

INTRODUCTION

Changes in regional cerebral blood flow (rCBF) have been reported in idiopathic Parkinson's disease (PD). Nonetheless, their typical pattern still remains controversial regarding some features, such as basal ganglia involvement and the main cortical regions affected. Functional neuroimaging makes it possible to identify the brain dysfunctions of the neural circuits underlying the disease. Voxel-based analysis methods make it possible to increase the reliability of the results.

OBJECTIVE

To assess the rCBF changes in patients with PD and their relation with disease duration.

MATERIALS AND METHODS

Thirty PD adult patients without dementia underwent evaluation with (99m)Tc-ECD SPECT. SPM5 was used for statistical comparison with 25 normal controls of similar ages. The disease course duration in years was added as a covariate. Additionally, patients with a 6-year evolution or less and those with more than 6 years were compared separately with normal controls.

RESULTS

Significant hypoperfusion was detected in bilateral premotor and posterior parietal cortex and increase of perfusion was present in the cerebellum. These changes correlated with the years of evolution of the illness. Patients with longer evolution also presented thalamic, subthalamic and basal ganglia hypoperfusion.

CONCLUSIONS

We describe rCBF changes in PD in neural circuits related with control of movements. These changes are more manifest in patients with a longer duration of the disease.

Initial High-Grade T1 Urothelial Cell Carcinoma: Feasibility and Prognostic Significance of Lamina Propria Invasion Microstaging (T1a/b/c) in BCG-Treated and BCG-Non-Treated Patients

OBJECTIVES

This study aimed to determine the prognostic value of depth of lamina propria invasion in initial high-grade T1 bladder tumors. Secondary aims were to evaluate the prognostic significance of concomitant carcinoma in situ (CIS) and the impact of bacillus Calmette-Guérin (BCG) treatment as well as to assess the feasibility of microstaging by pathologists in a community setting.

PATIENTS AND METHODS

Ninety-seven tumors were available for study and were substaged according to invasion superficial to, into or beyond the muscularis mucosae (MM) (T1a, T1b, T1c). Outcomes were compared by chi-square analysis. Recurrence-free and progression-free survival estimates were obtained by Kaplan-Meier analysis. BCG treatment impact and prognostic significance of CIS were also evaluated (Cox regression).

RESULTS

T1 subclassification was possible in 87% (85/97) of cases: 38 (39.1%) T1a, 10 (10.3%) T1b, and 37 (38.1%) T1c; in 12 patients (12.4%) substaging was not possible. Mean age was 66.4 years and mean follow-up was 53 months. Recurrence rates were similar for all groups. By contrast, the progression rate for deep lamina propria-invasive tumors, i.e. T1b and T1c, was 34% (16/47) in comparison to 8% (3/38) for T1a (p=0.016). Progression-free intervals were significantly different in patients with (T1b, T1c) or without (T1a) deep lamina propria involvement (p=0.003), regardless of BCG treatment (p=0.02). BCG-treated patients (67 cases) showed a slight trend towards a better outcome, but differences were not significant. CIS was associated with more than 50% of cases that progressed. On multivariate analysis, depth of invasion and CIS remained two independent prognostic factors, increasing the hazards ratio of progression to 4.47 and 3.19 respectively.

CONCLUSIONS

The depth of invasion in the TURB specimens is an independent prognostic factor for T1 bladder cancer even in BCG-treated patients. Associated CIS significantly increases the risk of progression in these patients. The percentage of cases that can be substaged according to the depth of lamina propria involvement increases over time with the collaboration between urologists and pathologists. Consequently, we support that routine pathological assessment of the level of MM invasion in patients with stage T1 bladder cancer should be included in the histopathological report.

Prostatic abscess due to Candida with no systemic manifestations

Prostatic abscess due to fungi is a rare condition. It is generally secondary to systemic disease in immunosuppressed patients. It usually occurs with affection of other organs in a septic patient. Only in exceptional cases does it occur isolatedly. We present the case of a prostatic abscess due to Candida albicans with no systemic manifestations. The diagnosis is helped by transrectal ultrasound, which allows to differentiate this condition from nonabscessed acute prostatitis. The treatment of choice is ultrasound-guided transrectal needle aspiration after antibiotic therapy has been started. As with abscesses of bacterial origin, an ultrasonographic follow-up is required due to the possibility of persistence or recurrence.