Prognostic utility of magnetic resonance imaging (MRI) in predicting neurological outcomes in patients with acute thoracolumbar spinal cord injury.

PURPOSE: Utility of MRI for predicting neurological outcomes in acute cervical spinal cord injury (SCI) is well established but its value in thoracolumbar (TL) SCI needs to be evaluated. METHODS: Seventy-six patients operated for acute TL spinal injuries between January 2014 and March 2016 were reviewed to obtain demographic details, neurology at admission and at the final follow-up. Patients were divided based on the neurology at presentation into group 1 (ASIA A), group 2 (ASIA B, C, D) and group 3 (normal neurology). Preoperative MRI and CT scans were evaluated to measure parameters like osseus canal compromise, spinal cord compression (SCC), spinal cord swelling, length of cord swelling (LOS), length of edema (LOE) and the presence of hemorrhage. The MRI parameters were compared between the groups for their predictive value of neurology on admission and at the final follow-up. RESULTS: Of the 38 patients in group 1, six patients recovered by 1 grade, nine patients recovered by 2 grades and there was no recovery in 23 (60.5%) patients. Among group 2 patients, nine (40.9%) out of 22 recovered to ASIA E neurology. On univariate analysis, SCC (P = 0.009), LOS (P = 0.021) and length of edema (P = 0.002) were associated with complete neurological deficit at presentation. However, on multivariate regression analysis only LOE was significant (P = 0.007) in predicting neurology at admission and at follow-up. CONCLUSION: Greater the rostrocaudal LOE, worse is the neurology at presentation, and it is associated with poor neurological recovery at follow-up. These slides can be retrieved under Electronic Supplementary Material.

TiO2 NPs Induce DNA Damage in Lymphocytes from Healthy Individuals and Patients with Respiratory Diseases-An Ex Vivo/In Vitro Study.

Little is known of the effects of nanoparticles in human systems, let alone in diseased individuals and nanotechnology has preceded nanotoxicology. Therefore, the effects of titanium dioxide (TiO2) nanoparticles in peripheral blood lymphocytes from patients with respiratory diseases [lung cancer, chronic obstructive pulmonary disease (COPD) and asthma] were compared with those in healthy Individuals, to determine differences in sensitivity to nanochemical insult. The Comet assay was performed according to recommended guidelines. The micronucleus assay and ras oncoprotein detection were conducted according to published standard methods. The results showed statistically significant concentration-dependent genotoxic effects of TiO2 NPs in both respiratory patient and control groups in the Comet assay. The TiO2 NPs caused DNA damage in a concentration dependent manner in both groups (respiratory and healthy controls) with the exception of the lowest TiO2 concentration (10 µg/ml) which did not induce significant damage in healthy controls (n.s). When OTM data were used to compare the whole patient group and the control group, the patient group had more DNA damage (p > 0.001) with the exception of 10 µg/ml of TiO2 that caused less significant damage to patient lymphocytes (p < 0.05). Similarly, there was an increase in the pattern of cytogenetic damage measured in the MN assay without statistical significance except when compared to the negative control of healthy individuals. Furthermore, when modulation of ras p21 expression was investigated, regardless of TiO2 treatment, only lung cancer and COPD patients expressed measurable ras p21 levels. Results were achieved in the absence of cytotoxicity.

Molecular dosimetry of endogenous and exogenous O(6)-methyl-dG and N7-methyl-G adducts following low dose [D3]-methylnitrosourea exposures in cultured human cells.

For DNA-reactive chemicals, a low dose linear assessment of cancer risk is the science policy default. In the present study, we quantitated the endogenous and exogenous N7-methyl-G and O(6)-methyl-dG adducts in human lymphoblastoid cells exposed to low dose [D3]-methylnitrosourea. Endogenous amounts of both adducts remained nearly constant, while the exogenous adducts showed linear dose-responses. The data show that O(6)-methyl-dG adducts ≥1.8/10(8) dG correlated with published studies that demonstrated significant increases of mutations under these conditions. The combined results do not support linear extrapolations to zero when data are available for science-based regulations.

Variation in thoracic inlet measurements and its correlation with pulmonary dysfunction in kyphoscoliotic deformities: a prospective case-control study.

BACKGROUND: Pulmonary dysfunction in thoracic kyphoscoliosis has been correlated with chest wall distortion, uneven trunk growth and restrictive pattern. The study aims to analyse the variation in thoracic inlet measurements on pulmonary dysfunction with varying curve magnitude and thoracic cage parameters. METHODS: In a non-randomised, prospective case-control study, 80 consecutive patients with thoracic kyphoscoliosis were divided into 3 groups based on Cobb angle: Group 1 (31-50), Group 2 (51-80) and Group 3 (> 80). Thoracic inlet measurement was calculated by thoracic inlet index (TI) on MRI at the sternal level. Pulmonary function and thoracic cage parameters [hemi thorax height, rib-apex distance, AP chest diameter at sternal level and transverse thoracic diameter] were documented. TI values were compared with 20 age-matched asymptomatic controls. Multivariate correlation and regression analysis were performed to investigate the correlations. RESULTS: The mean age of the study cohort was 14.1 ± 4.4 years, including Group 1 (6 patients), Group 2 (55 patients) and Group 3 (19 patients) versus 12.9 ± 2.2 years in controls. The mean TI was 2.8 ± 0.56 in Group 1, 3.7 ± 0.9 in Group 2 and 4.0 ± 1.12 in Group 3 versus 2.6 ± 0.43 in controls. Pulmonary dysfunction was severe with TI > 7.1 (p < 0.001) in Group 3 patients with thoracic hypokyphosis. Multivariate regression for thoracic parameters and TI > 5.6 showed significant correlation of pulmonary dysfunction in Group 2 and 3 curves with apex between T1 and T4, whereas transverse thoracic diameter, rib-apex distance and hemi thorax height were weakly associated. CONCLUSION: Thoracic inlet index (TI), a neglected pre-operative variable associated with pulmonary dysfunction in thoracic kyphoscoliosis, can be evaluated on MRI without an additional cost and radiation.

C7 distal fixation anchor and its influence on sagittal profile in posterior cervical fusion; a retrospective analysis of 44 cases.

Study design: Retrospective. Purpose: In multilevel posterior cervical fusion, whether to stop distal fixation at C7 or T1, remains a matter of debate. We aimed to assess clinical feasibility of C7 as distal fixation point and sought to compare complication rates and radiological outcome between lateral mass screws and pedicle screws at C7. Overview of literature: Current literature remains inconclusive regarding need for thoracic extension of instrumentation in multilevel posterior cervical fusion. Methods: We did a retrospective review of 44 consecutive patients who underwent posterior instrumented cervical decompression and fusion for degenerative cervical myelopathy with C7 as distal fixation point, and a minimum follow-up period of two years. We had two groups of patients based on C7 instrumentation. Group 1: Lateral mass screw fixation. Group 2: Pedicle screw fixation. Primary outcome: Post-operative clinico-radiological evaluation of whole study population Secondary outcome: Comparison of complication rates and radiological outcome between groups 1 and 2. Results: Mean age was 58.06 ± 14.4 years with average follow-up duration of 35.4 ± 4.5 months. There were 18 patients in Group 1 and 26 patients in Group 2. Mean pre-operative mJOA score was 10.51 and post-operative mJOA score was 15.74 with mean recovery rate (RR) 69.82%, of which 30 patients (70.23%) had good recovery and 14 patients (29.77%) had fair recovery at final follow up. The two groups didn't show any significant difference in complication rates and outcome. Conclusion: C7 as distal fixation anchor is safe and effective in maintaining cervical sagittal balance following multilevel posterior cervical fusion. C7 lateral mass screws are found to be equally efficacious as pedicle screws in preventing worsening of sagittal profile.

Zinc oxide nanoparticles induce oxidative DNA damage and ROS-triggered mitochondria mediated apoptosis in human liver cells (HepG2).

The wide scale use of Zinc oxide (ZnO) nanoparticles in the world consumer market makes human beings more prone to the exposure to ZnO nanoparticles and its adverse effects. The liver, which is the primary organ of metabolism, might act as a major target organ for ZnO nanoparticles after they gain entry into the body through any of the possible routes. Therefore, the aim of the present study was to assess the apoptotic and genotoxic potential of ZnO nanoparticles in human liver cells (HepG2) and the underlying molecular mechanism of its cellular toxicity. The role of dissolution in the toxicity of ZnO nanoparticles was also investigated. Our results demonstrate that HepG2 cells exposed to 14-20 µg/ml ZnO nanoparticles for 12 h showed a decrease in cell viability and the mode of cell death induced by ZnO nanoparticles was apoptosis. They also induced DNA damage which was mediated by oxidative stress as evidenced by an increase in Fpg sensitive sites. Reactive oxygen species triggered a decrease in mitochondria membrane potential and an increase in the ratio of Bax/Bcl2 leading to mitochondria mediated pathway involved in apoptosis. In addition, ZnO nanoparticles activated JNK, p38 and induced p53(Ser15) phosphorylation. However, apoptosis was found to be independent of JNK and p38 pathways. This study investigating the effects of ZnO nanoparticles in human liver cells has provided valuable insights into the mechanism of toxicity induced by ZnO nanoparticles.

Induction of oxidative stress, DNA damage and apoptosis in mouse liver after sub-acute oral exposure to zinc oxide nanoparticles.

Zinc oxide (ZnO) nanoparticles are finding applications in a wide range of products including cosmetics, food packaging, imaging, etc. This increases the likelihood of human exposure to these nanoparticles through dermal, inhalation and oral routes. Presently, the majority of the studies concerning ZnO nanoparticle toxicity have been conducted using in vitro systems which lack the complex cell-cell, cell-matrix interactions and hormonal effects found in the in vivo scenario. The present in vivo study in mice was aimed at investigating the oral toxicity of ZnO nanoparticles. Our results showed a significant accumulation of nanoparticles in the liver leading to cellular injury after sub-acute oral exposure of ZnO nanoparticles (300 mg/kg) for 14 consecutive days. This was evident by the elevated alanine aminotransferase (ALT) and alkaline phosphatase (ALP) serum levels and pathological lesions in the liver. ZnO nanoparticles were also found to induce oxidative stress indicated by an increase in lipid peroxidation. The DNA damage in the liver and kidney cells of mice was evaluated by the Fpg-modified Comet assay which revealed a significant (p<0.05) increase in the Fpg-specific DNA lesions in liver indicating oxidative stress as the cause of DNA damage. The TUNEL assay revealed an induction of apoptosis in the liver of mice exposed to ZnO nanoparticles compared to the control. Our results conclusively demonstrate that sub-acute oral exposure to ZnO nanoparticles in mice leads to an accumulation of nanoparticles in the liver causing oxidative stress mediated DNA damage and apoptosis. These results also suggest the need for a complete risk assessment of any new engineered nanoparticle before its arrival into the consumer market.

Incidence of Renal Tract Abnormalities on Ultrasonography in Patients with Spinal Cord Injury: A Retrospective Pilot Study of a Military Cohort Undergoing Long-Term Institutional Rehabilitation.

STUDY DESIGN: Retrospective pilot study. PURPOSE: To assess the incidence of renal tract abnormalities using ultrasonography (US) in a military cohort with traumatic spinal cord injury (TSCI) at a tertiary level spinal cord injury center. OVERVIEW OF LITERATURE: Neurogenic bladder in TSCI patients results in significant urological morbidity. There is lack of data for these patients during the first 18 months of long-term rehabilitation in an institutional setting. METHODS: We retrospectively reviewed patient records to collect data on demographic characteristics, injury level, injury severity, time since injury, bladder management methods (such as an indwelling catheter [IC], clean intermittent catheterization [CIC], or self-voiding [S]); we correlated these data with the findings of the renal tract US. RESULTS: The study included 73 out of 81 male participants. The mean patient age was 29.99 years; the study group included 34.2% tetraplegics and 65.8% people with paraplegia. The time since injury was 6-12 months for 42.5% of the subjects and 12-18 months for 57.5% of the subjects. A normal US scan was recorded in 65.7% patients, and bladder trabeculation was the commonest finding in 15.1% of the subjects, followed by hydronephrosis (HDN) in 12.3%, and renal calculus and atrophy in 1.3% participants each. We found 22.22% of the IC group participants had higher US abnormalities than those in the reflex voiding group (statistically non-significant difference, p=0.7). Trabeculations (21.4%) and HDN (19%) were more common in those who had sustained the injury 12-18 months previously as compared to that in those who had injured themselves 6-12 months previously (p=0.04). The proportion of patients who had a normal US scan was higher in the group who sustained the injury 6-12 months previously versus those who had sustained the injury 12-18 months previously; the difference was statistically significant (p=0.02). There was no significant (p=0.72) correlation in the bladder management method, injury level, and renal tract abnormalities between the groups. CONCLUSIONS: This retrospective study shows that 65% of TSCI participants had no renal tract abnormality on US scan and bladder trabeculation ruled out as the most common finding. Long-term supervised rehabilitation may help achieve good renal quality of life; however, further prospective trials are required on this subject.

Zinc oxide nanoparticle induced genotoxicity in primary human epidermal keratinocytes.

Zinc oxide (ZnO) nanoparticles are widely used in cosmetics and sunscreens. Human epidermal keratinocytes may serve as the first portal of entry for these nanoparticles either directly through topically applied cosmetics or indirectly through any breaches in the skin integrity. Therefore, the objective of the present study was to assess the biological interactions of ZnO nanoparticles in primary human epidermal keratinocytes (HEK) as they are the most abundant cell type in the human epidermis. Cellular uptake of nanoparticles was investigated by scanning electron microscopy using back scattered electrons imaging as well as transmission electron microscopy. The electron microscopy revealed the internalization of ZnO nanoparticles in primary HEK after 6 h exposure at 14 microg/ml concentration. ZnO nanoparticles exhibited a time (6-24 h) as well as concentration (8-20 microg/ml) dependent inhibition of mitochondrial activity as evident by the MTT assay. A significant (p < 0.05) induction in DNA damage was observed in cells exposed to ZnO nanoparticles for 6 h at 8 and 14 microg/ml concentrations compared to control as evident in the Comet assay. This is the first study providing information on biological interactions of ZnO nanoparticles with primary human epidermal keratinocytes. Our findings demonstrate that ZnO nanoparticles are internalized by the human epidermal keratinocytes and elicit a cytotoxic and genotoxic response. Therefore, caution should be taken while using consumer products containing nanoparticles as any perturbation in the skin barrier could expose the underlying cells to nanoparticles.

Impact of COVID-19 pandemic on orthopaedic surgeons in terms of anxiety, sleep outcomes and change in management practices: A cross-sectional study from India.

PURPOSE: The aim of this study was to assess the effects of the COVID-19 pandemic on anxiety, sleep outcomes and change in clinical management practices among orthopaedic surgeons following a nation-wide lockdown. METHODS: We conducted an online cross-sectional study using piloted structured questionnaires with self-reported responses from Indian orthopaedic surgeons. Study participants were identified through social networking sites: Facebook and WhatsApp. The extent of anxiety and sleep quality was assessed by the standardised seven-item Generalised Anxiety Disorder (GAD-7) scale, single-item sleep quality scale, questions on unavailability of personal protective equipment, training module on COVID-19 and change in orthopaedic patient management. RESULTS: One hundred male orthopaedic surgeons responded to the survey with majority (79%) in 30-44 years age group. Severe anxiety scores were observed in 8%; moderate, mild and minimal anxiety was observed in 12%, 27% and 53% surgeons respectively. Changes in management practice due to the pandemic was admitted by 65% respondents. We also observed an association between higher anxiety among surgeons and primary or secondary level of healthcare facility: (p = 0.04). Sleep disturbance was significantly associated with change in management practice to non-operative procedures (p = 0.03). CONCLUSION: Anxiety among orthopaedic surgeons during the COVID-19 pandemic is related to factors like younger age group, working in a primary or secondary healthcare facility. Early recognition of anxiety is essential to prevent serious psychological sequelae.

Thirty-Six-Month Follow-up of Diaphragm Pacing with Phrenic Nerve Stimulation for Ventilator Dependence in Traumatic Tetraplegia: The Way Forward for Spinal Cord Injury Rehabilitation in a Developing Country.

Respiratory failure and chronic ventilator dependence in tetraplegics following cervical injuries located high on the spine (C1-C3) constitute significant challenges in the rehabilitation of patients given the occurrence of repeated hospitalizations and an ever-increasing financial burden. A 30-year-old man presented with posttraumatic tetraplegia following an unstable injury at the C1-C2 level with cord compression; he was managed by posterior stabilization and decompression followed by ventilator dependence and no rehabilitation until 6 months postinjury. We implanted phrenic nerve stimulator electrodes bilaterally for indirect diaphragm pacing by an implantable pulse generator that allowed for weaning from mechanical ventilation and spontaneous ventilator-free breathing at 20 weeks post-implantation and which facilitated post-tetraplegia rehabilitation. At 36 months after implantation, the patient is ventilator-free without any procedure-related complications or respiratory infections. Diaphragm pacing with phrenic nerve stimulation may be a way forward for ventilator-dependent tetraplegics in developing countries to pursue effective rehabilitation and improved quality of life.

A study to analyze the pattern of synovial lesions from synovial biopsies in a tertiary care centre.

INTRODUCTION: Synovium has been documented as a primary site of inflammation and a major effector organ in a variety of joint diseases. Study of simple technique like synovial biopsy can help in early diagnosis and treatment of diseases significantly improving outcome of patient in cases of rheumatoid arthritis, osteoarthritis, etc., Only limited data exist on utility of synovial biopsies. AIM AND OBJECTIVES: To analyze the pattern of synovial lesions to differentiate between different kinds of arthritis. Also, to identify early stages of arthritis so as to prevent unnecessary invasive surgical procedure. MATERIALS AND METHODS: It's a retrospective study to analyze 103 cases of synovial lesions diagnosed in last five years at a tertiary care orthopedic center. All synovial biopsies obtained mainly by open method and few by arthroscopic method, that came to the Dept of Pathology were included. Lesions were classified into four categories that is, inflammatory joint diseases, degenerative joint diseases, tumor-like conditions and tumors. RESULTS: Age group most affected was between 61 and 70 years, with male predominance. Osteoarthritis (OA) was the most common histopathological diagnosis. Early OA tissues showed greater lining layer thickness, vessel proliferation, and inflammation, while surface fibrin deposition along with fibrosis was noted in later stages. CONCLUSION: The histo-morphological observations made in this study may have important therapeutic implications for some patients during the early evolution of arthritis and could prevent unnecessary operative intervention of later stages.

Toxicity assessment of nanomaterials: methods and challenges.

The increasing use of nanomaterials in consumer and industrial products has aroused global concern regarding their fate in biological systems, resulting in a demand for parallel risk assessment. A number of studies on the effects of nanoparticles in in vitro and in vivo systems have been published. However, there is still a need for further studies that conclusively establish their safety/toxicity, due to the many experimental challenges and issues encountered when assessing the toxicity of nanomaterials. Most of the methods used for toxicity assessment were designed and standardized with chemical toxicology in mind. However, nanoparticles display several unique physicochemical properties that can interfere with or pose challenges to classical toxicity assays. Recently, some new methods and modified versions of pre-existing methods have been developed for assessing the toxicity of nanomaterials. This review is an attempt to highlight some important methods employed in nanomaterial toxicology and to provide a critical analysis of the major issues/challenges faced in this emerging field.

Anxiety and Sleep Disturbances Among Health Care Workers During the COVID-19 Pandemic in India: Cross-Sectional Online Survey.

BACKGROUND: The COVID-19 pandemic caused by SARS-CoV-2 has become a serious concern among the global medical community and has resulted in an unprecedented psychological impact on health care workers, who were already working under stressful conditions. OBJECTIVE: In this study, we aimed to evaluate and measure the effects of the COVID-19 pandemic on the anxiety levels and sleep quality among health care workers in India, as well as to determine how the unavailability of personal protective equipment affects their willingness to provide patient-related care. METHODS: We conducted an online cross-sectional study using piloted, structured questionnaires with self-reported responses from 368 volunteer male and female health care workers in India. Study participants were identified through social networking platforms such as Facebook and WhatsApp. The survey evaluated the participants' degree of signs and symptoms of anxiety and sleep quality based on the 7-item Generalized Anxiety Disorder (GAD-7) scale and single-item Sleep Quality Scale, respectively. Information on the availability of personal protective equipment was collected based on responses to relevant survey questions. RESULTS: The majority of health care workers (126/368, 34.2%) were in the age group 45-60 years, and 52.2% (192/368) were doctors. Severe anxiety (ie, GAD-7 score >10) was observed among 7.3% (27/368) health care workers, whereas moderate, mild, and minimal anxiety was observed among 12.5% (46/368), 29.3% (108/368), and 50.8% (187/368) health care workers, respectively. Moreover, 31.5% (116/368) of the health care workers had poor-to-fair sleep quality (ie, scores <6). Univariate analysis showed female gender and inadequate availability of personal protective equipment was significantly associated with higher anxiety levels (P=.01 for both). Sleep disturbance was significantly associated with age <30 years (P=.04) and inadequate personal protective equipment (P<.001). Multivariable analysis showed that poorer quality of sleep was associated with higher anxiety levels (P<.001). CONCLUSIONS: The COVID-19 pandemic has potentially caused significant levels of anxiety and sleep disturbances among health care workers, particularly associated with the female gender, younger age group, and inadequate availability of personal protective equipment. These factors put health care workers at constant risk of contracting the infection themselves or transmitting it to their families. Early identification of at-risk health care workers and implementation of situation-tailored mitigation measures could help alleviate the risk of long-term, serious psychological sequelae as well as reduce current anxiety levels among health care workers.

Does preventive care bundle have an impact on surgical site infections following spine surgery? An analysis of 9607 patients.

STUDY DESIGN: Retrospective cohort study. OBJECTIVES: The purpose was to analyze the effect of care bundle protocol on SSI in our institution. Postoperative surgical site infections (SSI) pose significant health burden. In spite of the use of prophylactic antibiotics, surgical advances and postoperative care, wound infection continues to affect patient outcomes after spine surgery. METHODS: Retrospective analysis of 9607 consecutive patients who underwent spine procedures from 2014 to 2018 was performed. Preventive care bundle was implemented from January 2017 consisting of (a) preoperative bundle-glycemic control, chlorhexidine gluconate (CHG) bath, (b) intra-operative bundle-time specified antibiotic prophylaxis, CHG+ alcohol-based skin preparation (c) postoperative bundle-five moments of hand hygiene, early mobilization and bundle auditing. Patients operated from January 2017 were included in the post-implementation cohort and prior to that the pre-implementation cohort was formed. Data were drawn from weekly and yearly spine audits from the hospital infection committee software. Infection data were collected based on CDC criteria, further sub classification was done based on procedure, spinal disorders and spine level. Variables were analyzed and level of significance was set as < 0.05. RESULTS: A total of 7333 patients met the criteria. The overall SSI rate decreased from 3.42% (131/3829) in pre-implementation cohort to 1.22% (43/3504, p = 0.0001) in post-implementation cohort (RR = 2.73, OR = 2.79). Statistically significant reduction was seen in all the groups (a) superficial and deep, (b) early and late and (c) instrumented and uninstrumented groups but was more pronounced in early (p = 0.0001), superficial (p = 0.0001) and instrumented groups (p = 0.0001). On subgroup analysis based on spine level and spinal disorders, significant reduction was seen in lumbar (p = 0.0001) and degenerative group (p = 0.0001). CONCLUSIONS: Our study revealed significant reduction of SSI secondary to strict bundle adherence and monitored compliance compared to patients who did not receive these interventions. LEVEL OF EVIDENCE: III.

Unplanned Readmissions after Spine Surgery: A Single-Center Prospective Analysis of a 90-Day Model in 2,860 Cases.

STUDY DESIGN: Prospective study. PURPOSE: During the last decades, an emergence of unplanned readmissions has been shown to be a useful tool to gage the healthcare quality and hospital performance. Previous studies were limited by their retrospective designs based on database information and short-term 30-day follow-up intervals. We analyzed the incidence and causes for unplanned readmissions following spine surgery at a 90-day interval and the difference at 30-, 31-60-, and 61-90-day intervals after discharge. Additionally, we assessed total beddays lost and the economic impact of readmissions and probable risk factors. OVERVIEW OF LITERATURE: Recent reports on readmission rates suggested the contribution of this parameter for the assessment of healthcare quality. METHODS: A prospective analysis of 2,860 admissions was performed over 1 year in a tertiary care orthopedic hospital. All unscheduled readmissions following spine surgery within 90 days of discharge were included, irrespective of type or location of surgery. Polytrauma, primary osseous infections, and planned readmissions were excluded. RESULTS: Our readmission rate was 3.32% (95/2,860). Leading readmission causes were surgical site infections (SSIs) accounting for 44.21% (n=42; superficial, 23; deep, 11; organ and space, 8), followed by aseptic pain 31.58% (n=30) and medical causes 13.68% (n=13). Though 86.95% of superficial SSIs occurred within 30 days, 21.1% of deep SSIs occurred beyond 30 days. During the 30-90-day interval, 33.68% of readmissions occurred. The financial burden amounted to 41,93,660 Indian Rupees, and the mean bed-days lost was 7.33 per readmission. Hospital stay ≥10 days, health insurance, and comorbid illnesses (diabetes, hypertension, and liver disease) were associated with readmissions (p<0.05). CONCLUSIONS: Our study showed that SSIs and aseptic pain were the leading causes of readmissions at 90 days after spine surgery. Limiting the analysis to 30-day readmissions as in previous studies would lead to failure in the identification of more severe complications like deep SSIs. Continued vigilance, particularly for patients with predisposing factors, could help alleviate the financial burden.

DNA damaging potential of zinc oxide nanoparticles in human epidermal cells.

At present, more than 20 countries worldwide are manufacturing and marketing different varieties of nanotech-based consumer products of which cosmetics form the largest category. Due to the extremely small size of the nanoparticles (NPs) being used, there is a concern that they may interact directly with macromolecules such as DNA. The present study was aimed to assess the genotoxicity of zinc oxide (ZnO) NPs, one of the widely used ingredients of cosmetics, and other dermatological preparations in human epidermal cell line (A431). A reduction in cell viability as a function of both NP concentration as well as exposure time was observed. ZnO NPs demonstrated a DNA damaging potential as evident from an increased Olive tail moment (OTM) of 2.13 +/- 0.12 (0.8 g/ml) compared to control 1.37 +/- 0.12 in the Comet assay after an exposure of 6 h. ZnO NPs were also found to induce oxidative stress in cells indicated by depletion of glutathione (59% and 51%); catalase (64% and 55%) and superoxide dismutase (72% and 75%) at 0.8 and 0.08 g/ml respectively. Our data demonstrates that ZnO NPs even at low concentrations possess a genotoxic potential in human epidermal cells which may be mediated through lipid peroxidation and oxidative stress. Hence, caution should be taken in their use in dermatological preparations as well as while handling.

Detection of DNA Double-Strand Breaks Using Pulsed-Field Gel Electrophoresis.

DNA is one of the most biologically important targets of exogenous and endogenous toxicants as well as carcinogens. Damage to DNA can be of different types (e.g., DNA adducts, DNA protein cross-links, single-strand breaks, oxidized bases, abasic sites, and double-strand breaks (DSBs)). DSBs are considered the most lethal form of DNA damage for eukaryotic cells, and if left unrepaired or misrepaired, can cause cell death, chromosome instability, and cancer. DSBs can arise in the cells through different sources and can be distinguished as endogenous or exogenous DSBs. Exogenous sources can be chemotherapeutic drugs, irradiation, and environmental chemicals. The endogenous causes of DNA DSBs in the cells are mainly reactive oxygen species and faulty repair of oxidative clustered DNA lesions. Qualitative and quantitative analysis of DNA DSBs is of utmost importance to understand physiologically relevant cellular processes as well as to investigate the genotoxic or clastogenic effects of toxicants. Pulsed-field gel electrophoresis (PFGE) is a widely used method for direct quantification of DNA DSBs. In this method, the cells exposed to DSB-inducing agents are embedded in the agarose blocks and lysed. These agarose blocks containing DNA are then run under multiple electric fields which are at 120° angle, to aid in the movement of large DNA strands. It gives a direct and specific measure of DSBs unlike the foci-based assays. This chapter provides a brief overview of the various commonly used approaches to analyze DNA DSBs and describes the theory, advantages and method of PFGE, for use in cells exposed to DNA DSB inducing agents.

Evidence that endogenous formaldehyde produces immunogenic and atherogenic adduct epitopes.

Endogenous formaldehyde is abundantly present in our bodies, at around 100 µM under normal conditions. While such high steady state levels of formaldehyde may be derived by enzymatic reactions including oxidative demethylation/deamination and myeloperoxidation, it is unclear whether endogenous formaldehyde can initiate and/or promote diseases in humans. Here, we show that fluorescent malondialdehyde-formaldehyde (M2FA)-lysine adducts are immunogenic without adjuvants in mice. Natural antibody titers against M2FA are elevated in atherosclerosis-prone mice. Staining with an antibody against M2FA demonstrated that M2FA is present in plaque found on the aortic valve of ApoE -/- mice. To mimic inflammation during atherogenesis, human myeloperoxidase was incubated with glycine, H2O2, malondialdehyde, and a lysine analog in PBS at a physiological temperature, which resulted in M2FA generation. These results strongly suggest that the 1,4-dihydropyridine-type of lysine adducts observed in atherosclerosis lesions are likely produced by endogenous formaldehyde and malondialdehyde with lysine. These highly fluorescent M2FA adducts may play important roles in human inflammatory and degenerative diseases.