Regulatory role of miR-125a expression with respect to its target genes LIFR, ERBB2 and STAT3 in the pathogenesis of recurrent pregnancy losses.

OBJECTIVES: Studies have investigated miR-125a for its predictable role in recurrent pregnancy loss (RPL) cases to regulate many biological events required for the maintenance of pregnancy by regulating its confirmed target genes LIFR, ERBB2 and STAT3. METHODS: The present study included 40 cases of women with at least two RPLs in ≤20 weeks of gestation against 40 healthy multiparous women without a previous history of abortion. Expression analysis of ERBB2, LIFR, STAT3 and miR-125a was conducted by quantitative real-time PCR (qPCR). RESULTS: The expression of miR-125a was significantly lower in the plasma of RPL cases (P = 0.0001) and showed a significantly increased mean expression level in product of conception (2.56-fold, P < 0.0001). Among the target gene of miR-125a, ERBB2 and STAT3 gene expression level was significantly increased (2.58-fold, P = 0.04; 1.87-fold, P = 0.025), respectively in RPL cases while the LIFR gene revealed comparable expression (P = 0.64). Furthermore, expression analysis of ERBB2 gene with respect to its regulatory miR-125a cases depicted a significant association (P = 0.0005). Kaplan-Meier survival analysis revealed cases with low miR-125a expression had significantly shorter time to miscarriages, (log-rank P = 0.02). Also, decreased expression of miR-125a significantly conferred >2-fold increased risk for RPL (HR = 2.34: P < 0.05). CONCLUSION: The overall conclusion of the study was that altered miR-125a expression may cause deregulation in target genes LIFR, ERBB2 and STAT3 resulting in adverse consequence in the outcome of pregnancy.

Reviving grain quality in wheat through non-destructive phenotyping techniques like hyperspectral imaging.

A long-term goal of breeders and researchers is to develop crop varieties that can resist environmental stressors and produce high yields. However, prioritising yield often compromises improvement of other key traits, including grain quality, which is tedious and time-consuming to measure because of the frequent involvement of destructive phenotyping methods. Recently, non-destructive methods such as hyperspectral imaging (HSI) have gained attention in the food industry for studying wheat grain quality. HSI can quantify variations in individual grains, helping to differentiate high-quality grains from those of low quality. In this review, we discuss the reduction of wheat genetic diversity underlying grain quality traits due to modern breeding, key traits for grain quality, traditional methods for studying grain quality and the application of HSI to study grain quality traits in wheat and its scope in breeding. Our critical review of literature on wheat domestication, grain quality traits and innovative technology introduces approaches that could help improve grain quality in wheat.

FRAX-based intervention thresholds for Pakistan.

We compared, for women in Pakistan, the utility of intervention thresholds either at a T-score ≤ - 2.5 or based on a FRAX probability equivalent to women of average body mass index (BMI) with a prior fragility fracture. Whereas the FRAX-based intervention threshold identified women at high fracture probability, the T-score threshold was less sensitive, and the associated fracture risk decreased markedly with age. PURPOSE: The fracture risk assessment algorithm FRAX® has been recently calibrated for Pakistan, but guidance is needed on how to apply fracture probabilities to clinical practice. METHODS: The age-specific 10-year probabilities of a major osteoporotic fracture were calculated in women with average BMI to determine fracture probabilities at two potential intervention thresholds. The first comprised the age-specific fracture probabilities associated with a femoral neck T-score of - 2.5. The second approach determined age-specific fracture probabilities that were equivalent to a woman with a prior fragility fracture, without bone mineral density (BMD). The parsimonious use of BMD was additionally explored by the computation of upper and lower assessment thresholds for BMD testing. RESULTS: When a BMD T-score ≤ - 2.5 was used as an intervention threshold, FRAX probabilities in women aged 50 years were approximately two-fold higher than in women of the same age but with no risk factors and average BMD. The relative increase in risk associated with the BMD threshold decreased progressively with age such that, at the age of 80 years or more, a T-score of - 2.5 was actually protective. The 10-year probability of a major osteoporotic fracture by age, equivalent to women with a previous fracture, rose with age from 2.1% at the age of 40 years to 17%, at the age of 90 years, and identified women at increased risk at all ages. CONCLUSION: Intervention thresholds based on BMD alone do not effectively target women at high fracture risk, particularly in the elderly. In contrast, intervention thresholds based on fracture probabilities equivalent to a 'fracture threshold' target women at high fracture risk.

Peroneus Longus Tendon Harvesting for Anterior Cruciate Ligament Reconstruction.

There remains controversy regarding the ideal graft choice for anterior cruciate ligament (ACL) reconstruction1. Bone-patellar tendon-bone and hamstring autografts have been considered the gold standard for decades. Despite the good clinical outcomes, donor-site morbidity is a concern for both of these grafts2. Peroneus longus tendon autograft has also been considered as a potential graft for many orthopaedic reconstructive procedures3. The biomechanical properties and thickness of such a graft permit its use for ACL reconstruction3,4. The tensile strength of a peroneus longus tendon autograft is the same as that of a hamstring autograft and greater than that of a bone-patellar tendon-bone graft and a quadriceps tendon graft3,5. We aimed to describe the steps to harvest the peroneus longus tendon autograft during single-bundle ACL reconstruction. Description: Identification of anatomical landmarks is performed, including the distal aspect of the fibula and the posterior border of the fibula, 2 cm above the tip of the bone. A longitudinal incision is made along the posterior border of the fibular bone, from 2cm above the tip of the fibula. Care is taken to identify the tendon sheath that covers the longus and brevis approximately 2 cm above the superior extensor retinaculum, and the peroneus longus is stitched to the peroneus brevis. The proximal aspect of the peroneus longus tendon is whipstitched, after which the peroneus longus tendon and surrounding soft tissues are incised. The peroneus longus tendon is then released with use of a closed stripper, and the graft is prepared. Alternatives: Alternative nonoperative treatment options include physical therapy, nonsteroidal anti-inflammatory drugs, rest, and limitation of sporting activities. Alternative surgical treatment options include arthroscopic debridement, ACL repair or reconstruction with bone-patellar tendon-bone or hamstring-tendon autograft, and ACL reconstruction with allograft. Rationale: Recent studies have shown that ACL reconstruction with use of a peroneus longus tendon autograft is safe and effective, with less donor-site morbidity compared with other tendon autografts4,6,7. Expected Outcomes: The peroneus longus graft has been accepted for ligament reconstruction because of its strength, safety, and less donor-site morbidity7. The peroneus longus graft allows surgeons to harvest the autograft via a relatively small incision, resulting in fewer donor-site complications4. According to Rhatomy et al., the use of a peroneus longus graft provides good functional outcomes that are comparable with those of a hamstring autograft, but it has a larger graft diameter and its harvest results in less thigh hypotrophy8. Additionally, a case series of 10 patients who underwent ACL reconstruction with use of a peroneus longus autograft showed satisfactory Lysholm scores and low disability according to the Foot and Ankle Disability Index9. Important Tips: Examination under anesthesia and arthroscopic confirmation of the ACL tear are recommended prior to harvesting the peroneus longus tendon.Take care to identify the anatomical landmarks of the peroneus longus and brevis.Tenodesis of the peroneus longus to the brevis is performed first, followed by whipstitching of the peroneus longus proximal to the site of the tenodesis.Once the peroneus longus tendon is passed through the closed stripper, gently maintain traction on the sutures while pushing the stripper proximally until the tendon is freed.Care should be taken not to damage the superior peroneal retinaculum, which provides the primary restraint to tendon subluxation.Identification of the peroneus longus and brevis is important. The peroneus longus tendon is free of muscle attachment and more rounded in shape, while the peroneus brevis contains muscle fibers. Acronyms & Abbreviations: PL = peroneus longusCI = confidence intervalIKDC = International Knee Documentation Committee.

Implications of VEGF gene sequence variations and its expression in recurrent pregnancy loss.

RESEARCH QUESTION: What is the association between VEGF gene sequence variants and its mRNA expression in recurrent pregnancy loss (RPL)? Vascular endothelial growth factor (VEGF) has a prominent role in pregnancy and affects pregnancy outcome. The association of VEGF gene 1154G>A, 634G>C and 583C>T polymorphic variations with cases of RPL and full-term fertile women as controls was investigated. DESIGN: Two hundred women with RPL and 240 women healthy controls were included. The restriction fragment length polymorphism method was used for genotyping and quantitative real-time polymerase chain reaction was used for analysis of mRNA expression. RESULTS: In VEGF 1154G>A, significant differences were found in homozygous AA genotype between case and control participants. The variant allele A frequency was significantly more abundant in RPL cases (0.41) than controls (0.19) (P < 0.0001). Only RPL cases with the multi-generation family history of miscarriages and those without any history showed significant differences of combined genotype GA+AA (P < 0.0001). In VEGF 634 G>C, CC genotype and allele C showed significantly increased frequency in RPL cases compared with healthy controls (P < 0.0001). The association between VEGF-1154 G>A SNP and VEGF-A mRNA expression levels was significant in RPL cases (P = 0.004). Also in VEGF-583 C>T, CT genotypes were seen significantly associated with cases (P = 0.003). The heterozygous genotype GA was significantly (P = 0.03) associated with upregulation and downregulation of VEGF mRNA, whereas the homozygous variant genotype AA only leads to low expression levels of VEGF mRNA in patients with RPL. CONCLUSIONS: All the variants of VEGF play a vital role in an increased susceptibility to RPL. Also, VEGF-1154, AA genotypes are associated with its altered low mRNA expression in women with RPL and seem to affect pregnancy outcome.

A surrogate FRAX model for Pakistan.

A surrogate FRAX® model for Pakistan has been constructed using age-specific hip fracture rates for Indians living in Singapore and age-specific mortality rates from Pakistan. INTRODUCTION: FRAX models are frequently requested for countries with little or no data on the incidence of hip fracture. In such circumstances, the International Society for Clinical Densitometry and International Osteoporosis Foundation have recommended the development of a surrogate FRAX model, based on country-specific mortality data but using fracture data from a country, usually within the region, where fracture rates are considered to be representative of the index country. OBJECTIVE: This paper describes the development and characteristics of a surrogate FRAX model for Pakistan. METHODS: The FRAX model used the ethnic-specific incidence of hip fracture in Indian men and women living in Singapore, combined with the death risk for Pakistan. RESULTS: The surrogate model gave somewhat lower 10-year fracture probabilities for men and women at all ages compared to the model for Indians from Singapore, reflecting a higher mortality risk in Pakistan. There were very close correlations in fracture probabilities between the surrogate and authentic models (r ≥ 0.998) so that the use of the Pakistan model had little impact on the rank order of risk. It was estimated that 36,524 hip fractures arose in 2015 in individuals over the age of 50 years in Pakistan, with a predicted increase by 214% to 114,820 in 2050. CONCLUSION: The surrogate FRAX model for Pakistan provides an opportunity to determine fracture probability within the Pakistan population and help guide decisions about treatment.

Deletions of the Idh1, Eco1, Rom2, and Taf10 Genes Differently Control the Hyphal Growth, Drug Tolerance, and Virulence of Candida albicans.

The most recent genome-editing system called CRISPR-Cas9 (clustered regularly interspaced short palindromic repeat system with associated protein 9-nuclease) was employed to delete four non-essential genes (i.e., Caeco1, Caidh1, Carom2, and Cataf10) individually to establish their gene functionality annotations in pathogen Candida albicans. The biological roles of these genes were investigated with respect to the cell wall integrity and biogenesis, calcium/calcineurin pathways, susceptibility of mutants towards temperature, drugs and salts. All the mutants showed increased vulnerability compared to the wild-type background strain towards the cell wall-perturbing agents, (antifungal) drugs and salts. All the mutants also exhibited repressed and defective hyphal growth and smaller colony size than control CA14. The cell cycle of all the mutants decreased enormously except for those with Carom2 deletion. The budding index and budding size also increased for all mutants with altered bud shape. The disposition of the mutants towards cell wall-perturbing enzymes disclosed lower survival and more rapid cell wall lysis events than in wild types. The pathogenicity and virulence of the mutants was checked by adhesion assay, and strains lacking rom2 and eco1 were found to possess the least adhesion capacity, which is synonymous to their decreased pathogenicity and virulence.

A novel strategy for synthesis of Al powder comprising of Al nanoflakes via ultrasonication of Al foil.

Aluminum (Al) nanopowders have potential applications as hydrogen storage medium, energetic materials, pigments, and for production of metal matrix parts via powder metallurgy, to name a few. They are synthesized by methods which are either expensive or result in the product with impurities. A novel methodology based on ultrasonication of commercially available Al foil has been developed for synthesis of Al powders. Al foil was immersed in an organic medium and subjected to ultrasonication in a 160-watt bath ultrasonicator operated at 35 kHz frequency. Morphological, crystal structural, and dimensional characterization of ultrasonicated Al was carried out with the help of scanning electron microscopy (SEM), X-ray diffraction (XRD), and atomic forces microscopy (AFM) respectively. Characterization results revealed that Al foil was eroded laterally as well as axially, resulting in the formation of micro and nanosized flake-like pure Al powder.

Responses of testosterone hormone concentration, semen quality, and its related pro-inflammatory cytokines in bucks following Corynebacterium pseudotuberculosis and its mycolic acid infection.

Corynebacterium pseudotuberculosis is the causative agent of caseous lymphadenitis, a debilitating chronic disease of sheep and goats. Little is known about the buck's reproductive pathophysiology with respect to inoculation with Corynebacterium pseudotuberculois and its immunogen mycolic acid extract. Therefore, this present study was designed to determine the concentration of testosterone hormone, pro-inflammatory cytokines, and semen quality of the experimental animals. A total of 12 bucks, divided into groups 1, 2, and 3 (Negative control group, Positive control group and Mycolic acid group respectively), were enrolled in this study. Following inoculation, all goats were observed for clinical responses and monitored for 60 days post-challenge and were then sacrificed. Blood samples were collected via the jugular once before inoculation and on a weekly basis post-challenge. Semen samples were collected 2 weeks post-challenge and prior to the sacrifice of the experimental animals. During the post inoculation period of 60 days, the concentration of testosterone hormone for group 2 was increased significantly (p < 0.05) in weeks 5, 6, and 9 but decreased in weeks 2 and 7 post inoculation. In group 3, the mean concentration of testosterone was increased significantly (p < 0.05) in weeks 5, 6, 7, and 9 post inoculation but decreased in week 2. The concentration of interleukin 6 (IL 6) in treated group 2 did not show any significant difference (p > 0.05) but increased significantly (p < 0.05) in week 2 post inoculation in group 3. For concentration of interleukin 1ß (IL1ß) in both treated groups 2 and 3 showed significant difference (p < 0.05) in weeks 2 and 3 post inoculation. The tumor necrosis factor-alpha (TNF-α) concentration in both treated groups 2 and 3 did not show any significant difference (p > 0.05) as compared to group 1. The concentration of interferon-γ (IFNγ) significantly increased (p < 0.05) for group 2 for weeks 2, 3, 4, and 5 where else for group 3 was not in significant difference (p > 0.05) compared to group 1. Both group 2 and group 3 showed a reduction in semen qualities as compared to group 1, but the severity was more intense in group 2 if compared to group 3. In conclusion, therefore, the present study concluded that the mycolic acid group revealed significant responses of testosterone hormone concentration, semen quality, and its related pro-inflammatory cytokines in bucks following infection but the severity lesser compared to Corynebacterium pseudotuberculosis group.

Infected Non-union of Tibia Treated with Ilizarov External Fixator: Our Experience.

Introduction: Tibia is the most common long bone fractured due its vulnerable subcutaneous location and most often associated with acquired complications of delayed union or non-union due to infection. Amongst the various treatment options to treat them, the Ilizarov external fixator application is considered superior due to its multiple advantages. The objective of this study was to analyse the role of Ilizarov fixation in infected tibial non-union, as well as to assess bony union and associated functional outcomes. Materials and Methods: A retrospective review was conducted for the duration between 1st January 2005 to 31st December 2016. Total of fifty-one patients with tibial non-union associated with infection who treated with the Ilizarov fixator were included in the study. Patient records were reviewed for union of bone, bone and functional outcomes and complications. Results: The most common organism for infection was identified to be Staphylococcus Aureus. At the time of final follow-up all patients had achieved union except two, one of whom had to undergo amputation due to non-union and sepsis. Majority of the patients had an excellent score as per ASAMI grading system for bone and function results. The most common complication noted was pin track infections. Conclusion: In our experience, Ilizarov external fixator is better suited for infected non-union of tibia because it can provide a stable mechanical environment, bone transport, correct deformities, and enable weight bearing and hence we recommend its use for the same.

Surface degradation study of magnesium tested in simulated body fluid.

Magnesium has attracted a lot of attention as a new class of biodegradable material. The surface properties of magnesium in simulated body fluid (SBF) were investigated in the current research work. Cast magnesium samples with different surface characteristics were prepared which were then placed in SBF for 2, 4 and 8 days. This led to the formation of hydroxylapatite coating on their surfaces. The solution was changed at regular intervals to maintain a pH of 7.6. Other Mg samples were anodized at 40 V and 60 V to create a uniform layer of oxide on them and then their activity in SBF was compared with the casted samples of Mg. It was found that corrosion rate varies as the immersion time increases. Magnesium undergoes localized corrosion with pits and cracks forming on the surface of the samples. This was due to the aggressive corrosive nature of SBF.

Infected Non-union of Tibia Treated with Ilizarov External Fixator: Our Experience

@#Introduction: Tibia is the most common long bone fractured due its vulnerable subcutaneous location and most often associated with acquired complications of delayed union or non-union due to infection. Amongst the various treatment options to treat them, the Ilizarov external fixator application is considered superior due to its multiple advantages. The objective of this study was to analyse the role of Ilizarov fixation in infected tibial non-union, as well as to assess bony union and associated functional outcomes. Materials and Methods: A retrospective review was conducted for the duration between 1st January 2005 to 31st December 2016. Total of fifty-one patients with tibial non-union associated with infection who treated with the Ilizarov fixator were included in the study. Patient records were reviewed for union of bone, bone and functional outcomes and complications. Results:The most common organism for infection was identified to be Staphylococcus Aureus. At the time of final follow-up all patients had achieved union except two, one of whom had to undergo amputation due to non-union and sepsis. Majority of the patients had an excellent score as per ASAMI grading system for bone and function results. The most common complication noted was pin track infections. Conclusion: In our experience, Ilizarov external fixator is better suited for infected non-union of tibia because it can provide a stable mechanical environment, bone transport, correct deformities, and enable weight bearing and hence we recommend its use for the same.

Ankle Arthrodesis using Ilizarov Ring Fixator: A Primary or Salvage Procedure? An Analysis of Twenty Cases.

Introduction: Ankle arthrodesis using the Ilizarov technique provides high union rate with the added benefits of early weight-bearing, and the unique advantage of its ability to promote regeneration of soft tissue around the bone, including skin, muscle and neuro-vascular structures, and its versatility to allow correction of the position of the foot by adjusting the frame post-operatively as needed. We describe our experience with this technique and the functional outcomes in our patients. Materials and Methods: This retrospective study was conducted in 20 ankle fusion cases using the Ilizarov method between the years 2007 and 2017. We defined success in treatment by loss of preoperative symptoms and radiological union on plain radiographs of the ankle. Results: Fusion was achieved in all patients (100%). Immediate post-operative ambulation was with full weight bearing (FWB) in 16 (83%) of the participants and non-weight bearing (NWB) in 3 patients (17%). Post-procedure 11 patients (67%) of the participants who were full weight bearing required some form of support for walking for 2-3 weeks. Post-operatively three patients had pin tract infection requiring intravenous antibiotics. Radiological union took range of 6-12 weeks, mean union time was 8 weeks. Only one patient required bone grafting due to bone loss. Average follow-up period was 10-45 months. Conclusion: The Ilizarov technique has a high union rate and leads to general favourable clinical outcome and may be considered for any ankle arthrodesis but is especially useful in complex cases such as for revisions, soft-tissue compromise, infection and in patients with risk for non-union. Early weight bearing is an extra benefit.

Prevention of Aortic Dissection Suggests a Diameter Shift to a Lower Aortic Size Threshold for Intervention.

BACKGROUND: Multiple studies have quantified the relationship between aortic size and risk of dissection. However, these studies estimated the risk of dissection without accounting for any increase in aortic size from the dissection process itself. OBJECTIVES: This study aims to compare aortic size before and after dissection and to evaluate the change in size consequent to the dissection itself. METHODS: Fifty-five consecutive patients (29 type A; 26 type B) with aortic dissection and incidental imaging studies prior to dissection were identified and compared to a control group of aneurysm patients (n = 205). The average time between measurement at and prior to dissection was 1.7 ± 1.9 years (1.9 ± 2.0 years mean inter-image time in the control group). A multivariate regression model controlling for growth rate, age, and gender was created to estimate the effect of dissection itself on aortic size. RESULTS: The mean aortic sizes at and prior to dissection were 54.2 ± 7.0 and 45.1 ± 5.7 mm for the ascending aorta, and 47.1 ± 13.8 and 39.5 ± 13.1 mm for the descending aorta, respectively. The multivariable analysis revealed a significant impact of the dissection itself (p < 0.001) and estimated an increase in size of 7.65 mm (ascending aorta) and 6.38 mm (descending aorta). Thus, a proportional estimate of 82.8% (ascending aorta) and 80.8% (descending aorta) of dissections are made at a size lower than the guideline-recommended threshold (55 mm). CONCLUSIONS: The aortic diameter increases substantially due to aortic dissection itself and, thus, aortas are being dissected at clinically meaningfully smaller sizes than natural history analyses have previously suggested. These findings have important implications regarding the size at which the risk of dissection is increased.

Isolated spontaneous cerebrospinal fluid rhinorrhoea as a rare presentation of idiopathic intracranial hypertension: Case reports with comprehensive review of literature.

Isolated cerebrospinal fluid (CSF) rhinorrhoea as a sole presenting symptom of idiopathic intracranial hypertension (IIH) is extremely rare. IIH typically presents with headache, pulsatile tinnitus, dizziness, nausea, vomiting, and visual disturbance. We report two cases which presented with acute onset spontaneous CSF rhinorrhoea without any other symptom. In addition, we discuss in detail imaging features of IIH with review of its literature.

Ankle Arthrodesis using Ilizarov Ring Fixator: A Primary or Salvage Procedure? An Analysis of Twenty Cases

@#Introduction: Ankle arthrodesis using the Ilizarov technique provides high union rate with the added benefits of early weight-bearing, and the unique advantage of its ability to promote regeneration of soft tissue around the bone, including skin, muscle and neuro-vascular structures, and its versatility to allow correction of the position of the foot by adjusting the frame post-operatively as needed. We describe our experience with this technique and the functional outcomes in our patients. Materials and Methods: This retrospective study was conducted in 20 ankle fusion cases using the Ilizarov method between the years 2007 and 2017. We defined success in treatment by loss of preoperative symptoms and radiological union on plain radiographs of the ankle. Results: Fusion was achieved in all patients (100%). Immediate post-operative ambulation was with full weight bearing (FWB) in 16 (83%) of the participants and non-weight bearing (NWB) in 3 patients (17%). Postprocedure 11 patients (67%) of the participants who were full weight bearing required some form of support for walking for 2-3 weeks. Post-operatively three patients had pin tract infection requiring intravenous antibiotics. Radiological union took range of 6-12 weeks, mean union time was 8 weeks. Only one patient required bone grafting due to bone loss. Average follow-up period was 10-45 months. Conclusion: The Ilizarov technique has a high union rate and leads to general favourable clinical outcome and may be considered for any ankle arthrodesis but is especially useful in complex cases such as for revisions, soft-tissue compromise, infection and in patients with risk for non-union. Early weight bearing is an extra benefit.

Elective surgery for ascending aortic aneurysm in the elderly: should there be an age cut-off?

OBJECTIVES: The objective of this study is to retrospectively analyse surgical outcomes in patients aged 75-79, and 80 and above. METHODS: Between 2000 and 2015, 108 patients aged 75-79 (G 75 , mean age 76.9 ± 1.5years) and 72 patients aged 80 and above (G 80 , mean age 82.2 ± 2.1years) underwent elective aneurysm repair. Operative outcome and survival was compared with 727 contemporary younger counterparts aged <75 years (G Ctrl , mean age 56.6 ± 11.7years). RESULTS: Postoperatively, patients with advanced age showed a higher incidence of prolonged ventilation (G 80 21.4%, G 75 8.4%, G Ctrl 2.9%; P < 0.001), low cardiac output syndrome (G 80 11.4%, G 75 1.9%, G Ctrl 2.2%; P = 0.001), multi organ failure (G 80 2.9%, G 75 0%, G Ctrl 0.1%; P = 0.022), haemofiltration (G 80 8.6%, G 75 0.9%, G Ctrl 0.6%; P < 0.001), and infection (G 80 10.0%, G 75 6.5%, G Ctrl 3.5%; P = 0.017). Operative mortality was significantly increased in the elderly (G 80 11.1%, G 75 3.7%, G Ctrl 1.4%; P < 0.001). Mid-term survival differed significantly between the surgical groups. Multivariate regression analysis precluded age as an independent predictor of operative mortality. CONCLUSIONS: Elderly patients showed a higher operative risk compared to their younger counterparts. However, age per se is no suitable indicator of surgical risk and well-selected patients with large threatening aneurysms may benefit from intervention.

Can Transcutaneous CO2 Tension Be Used to Calculate Ventilatory Dead Space? A Pilot Study.

Dead space fraction (V d/V t) measurement performed using volumetric capnography requires arterial blood gas (ABG) sampling to estimate the partial pressure of carbon dioxide (PaCO2). In recent years, transcutaneous capnography (PtcCO2) has emerged as a noninvasive method of estimating PaCO2. We hypothesized that PtcCO2 can be used as a substitute for PaCO2 in the calculation of V d/V t. In this prospective pilot comparison study, 30 consecutive postcardiac surgery mechanically ventilated patients had V d/V t calculated separately using volumetric capnography by substituting PtcCO2 for PaCO2. The mean V d/V t calculated using PaCO2 and PtcCO2 was 0.48 ± 0.09 and 0.53 ± 0.08, respectively, with a strong positive correlation between the two methods of calculation (Pearson's correlation = 0.87, p < 0.05). Bland-Altman analysis showed a mean difference of -0.05 (95% CI: -0.01 to -0.09) between the two methods. PtcCO2 measurements can provide a noninvasive means to measure V d/V t, thus accessing important physiologic information and prognostic assessment in patients receiving mechanical ventilation.