Age-related upregulation of dense core vesicles in the central inferior colliculus.

Presbycusis is one of the most prevalent disabilities in aged populations of industrialized countries. As we age less excitation reaches the central auditory system from the periphery. To compensate, the central auditory system [e.g., the inferior colliculus (IC)], downregulates GABAergic inhibition to maintain homeostatic balance. However, the continued downregulation of GABA in the IC causes a disruption in temporal precision related to presbycusis. Many studies of age-related changes to neurotransmission in the IC have therefore focused on GABAergic systems. However, we have discovered that dense core vesicles (DCVs) are significantly upregulated with age in the IC. DCVs can carry neuropeptides, co-transmitters, neurotrophic factors, and proteins destined for the presynaptic zone to participate in synaptogenesis. We used immuno transmission electron microscopy across four age groups (3-month; 19-month; 24-month; and 28-month) of Fisher Brown Norway rats to examine the ultrastructure of DCVs in the IC. Tissue was stained post-embedding for GABA immunoreactivity. DCVs were characterized by diameter and by the neurochemical profile (GABAergic/non-GABAergic) of their location (bouton, axon, soma, and dendrite). Our data was collected across the dorsolateral to ventromedial axis of the central IC. After quantification, we had three primary findings. First, the age-related increase of DCVs occurred most robustly in non-GABAergic dendrites in the middle and low frequency regions of the central IC during middle age. Second, the likelihood of a bouton having more than one DCV increased with age. Lastly, although there was an age-related loss of terminals throughout the IC, the proportion of terminals that contained at least one DCV did not decline. We interpret this finding to mean that terminals carrying proteins packaged in DCVs are spared with age. Several recent studies have demonstrated a role for neuropeptides in the IC in defining cell types and regulating inhibitory and excitatory neurotransmission. Given the age-related increase of DCVs in the IC, it will be critical that future studies determine whether (1) specific neuropeptides are altered with age in the IC and (2) if these neuropeptides contribute to the loss of inhibition and/or increase of excitability that occurs during presbycusis and tinnitus.

Age-related upregulation of perineuronal nets on inferior collicular cells that project to the cochlear nucleus.

Introduction: Disruptions to the balance of excitation and inhibition in the inferior colliculus (IC) occur during aging and underlie various aspects of hearing loss. Specifically, the age-related alteration to GABAergic neurotransmission in the IC likely contributes to the poorer temporal precision characteristic of presbycusis. Perineuronal nets (PNs), a specialized form of the extracellular matrix, maintain excitatory/inhibitory synaptic environments and reduce structural plasticity. We sought to determine whether PNs increasingly surround cell populations in the aged IC that comprise excitatory descending projections to the cochlear nucleus. Method: We combined Wisteria floribunda agglutinin (WFA) staining for PNs with retrograde tract-tracing in three age groups of Fischer Brown Norway (FBN) rats. Results: The data demonstrate that the percentage of IC-CN cells with a PN doubles from ~10% at young age to ~20% at old age. This was true in both lemniscal and non-lemniscal IC. Discussion: Furthermore, the increase of PNs occurred on IC cells that make both ipsilateral and contralateral descending projections to the CN. These results indicate that reduced structural plasticity in the elderly IC-CN pathway, affecting excitatory/inhibitory balance and, potentially, may lead to reduced temporal precision associated with presbycusis.

Age-related Changes of GAD1 mRNA Expression in the Central Inferior Colliculus.

Encoding sounds with a high degree of temporal precision is an essential task for the inferior colliculus (IC) to perform and maintain the accurate processing of sounds and speech. However, the age-related reduction of GABAergic neurotransmission in the IC interrupts temporal precision and likely contributes to presbycusis. As presbycusis often manifests at high or low frequencies specifically, we sought to determine if the expression of mRNA for glutamic decarboxylase 1 (GAD1) is downregulated non-uniformly across the tonotopic axis or cell size range in the aging IC. Using single molecule in situ fluorescent hybridization across young, middle age and old Fisher Brown Norway rats (an aging model that acquires low frequency presbycusis) we quantified individual GAD1 mRNA in small, medium and large GABAergic cells. Our results demonstrate that small GABAergic cells in low frequency regions had ~58% less GAD1 in middle age and continued to decline into old age. In contrast, the amount of GAD1 mRNA in large cells in low frequency regions significantly increased with age. As several studies have shown that downregulation of GAD1 decreases the release of GABA, we interpret our results in two ways. First, the onset of presbycusis may be driven by small GABAergic cells downregulating GAD1. Second, as previous studies demonstrate that GAD67 expression is broadly downregulated in the old IC, perhaps the translation of GAD1 to GAD67 is interrupted in large GABAergic IC cells during aging. These results point to a potential genetic mechanism explaining reduced temporal precision in the aging IC, and in turn, presbycusis.

Tonotopic distribution and inferior colliculus projection pattern of inhibitory and excitatory cell types in the lateral superior olive of mice.

The principal neurons (PNs) of the lateral superior olive nucleus (LSO) are an important component of mammalian brainstem circuits that compare activity between the two ears and extract intensity and timing differences used for sound localization. There are two LSO PN transmitter types, glycinergic and glutamatergic, which also have different ascending projection patterns to the inferior colliculus (IC). Glycinergic LSO PNs project ipsilaterally while glutamatergic one's projections vary in laterality by species. In animals with good low-frequency hearing (<3 kHz) such as cats and gerbils, glutamatergic LSO PNs have both ipsilateral and contralateral projections; however, rats that lack this ability only have the contralateral pathway. Additionally, in gerbils, the glutamatergic ipsilateral projecting LSO PNs are biased to the low-frequency limb of the LSO suggesting this pathway may be an adaptation for low-frequency hearing. To further test this premise, we examined the distribution and IC projection pattern of LSO PNs in another high-frequency specialized species using mice by combining in situ hybridization and retrograde tracer injections. We observed no overlap between glycinergic and glutamatergic LSO PNs confirming they are distinct cell populations in mice as well. We found that mice also lack the ipsilateral glutamatergic projection from LSO to IC and that their LSO PN types do not exhibit pronounced tonotopic biases. These data provide insights into the cellular organization of the superior olivary complex and its output to higher processing centers that may underlie functional segregation of information.

Effect of duloxetine on opioid consumption and pain after total knee and hip arthroplasty: a systematic review and meta-analysis of randomized clinical trials.

OBJECTIVES: The purpose of this study was to investigate the analgesic effects of duloxetine, specifically on postoperative pain, opioid consumption, and related side effects following total hip or knee arthroplasty. METHODS: In this systematic review and meta-analysis, Medline, Cochrane, EMBASE, Scopus, and Web of Science were searched until November 2022 for studies which compared duloxetine with placebo when added to routine pain management protocols. Individual study risk of bias assessment was conducted based on Cochrane risk of bias tool 2. Random effect model meta-analysis was done on mean differences, to evaluate the outcomes. RESULTS: Nine randomized clinical trials (RCT) were included in the final analysis, totaling 806 patients. Duloxetine reduced opioid consumption (oral morphine milligram equivalents) on postoperative days (POD) 2 (mean difference (MD): -14.35, P = .02), POD 3 (MD: -13.6, P < .001), POD 7 (MD: -7.81, P < .001), and POD 14 (MD: -12.72, P < .001). Duloxetine decreased pain with activity on POD 1, 3, 7, 14, 90 (All P < .05), and pain at rest on POD 2, 3, 7, 14, and 90 (all P < .05). There was no significant difference in the prevalence of the side effects, except for increased risk of somnolence/drowsiness (risk ratio: 1.87, P = .007). CONCLUSION: Current evidence shows low to moderate opioid sparing effects of perioperative duloxetine and a statistically but not clinically significant reduction in pain scores. Patients treated with duloxetine had an increased risk for somnolence and drowsiness.

Mild Facial Paresis in a Recipient of Gam-COVID-Vac Vaccine: A Case Report.

Facial paralysis has been reported as a rare side effect of mRNA COVID-19 vaccines. The Gam-COVID-Vac was introduced in August 2020 in Russia. There was no report of facial paralysis in phase I to III clinical trials of the vaccine. To our knowledge, there is no post-marketing report of facial paresis with Gam-COVID-Vac vaccination to this date. The Gam-COVID-Vac vaccine has a reported efficacy of 90%, but its safety and efficacy have not been approved by international organizations to this date. Iran is among the countries using the Gam-COVID-Vac vaccine. Here, we present a case of mild facial paresis that occurred shortly after the Gam-COVID-Vac vaccine administration in a female healthcare worker.

Age-related ultrastructural changes in the lateral cortex of the inferior colliculus.

Temporal precision, a key component of sound and speech processing in the inferior colliculus (IC), depends on a balance of inhibition and excitation, and this balance degrades during aging. The cause of disrupted excitatory-inhibitory balance in aging is unknown, however changes at the synapse are a likely candidate. We sought to determine whether synaptic changes occur in the lateral cortex of the IC (IClc), a multimodal nucleus that processes lemniscal, intrinsic, somatosensory, and descending auditory input. Using electron microscopic techniques across young, middle age and old Fisher Brown Norway rats, our results demonstrate minimal loss of synapses in middle age, but significant (∼28%) loss during old age. However, in middle age, targeting of GABAergic dendrites by GABAergic synapses is increased and the active zones of excitatory synapses (that predominantly target GABA-negative dendrites) are lengthened. These synaptic changes likely result in a net increase of excitation in the IClc during middle age. Thus, disruption of excitatory-inhibitory balance in the aging IClc may be due to synaptic changes that begin in middle age.

Tonotopic distribution and inferior colliculus projection pattern of inhibitory and excitatory cell types in the lateral superior olive of Mongolian gerbils.

Sound localization critically relies on brainstem neurons that compare information from the two ears. The conventional role of the lateral superior olive (LSO) is extraction of intensity differences; however, it is increasingly clear that relative timing, especially of transients, is also an important function. Cellular diversity within the LSO that is not well understood may underlie its multiple roles. There are glycinergic inhibitory and glutamatergic excitatory principal neurons in the LSO, however, there is some disagreement regarding their relative distribution and projection pattern. Here we employ in situ hybridization to definitively identify transmitter types combined with retrograde labeling of projections to the inferior colliculus (IC) to address these questions. Excitatory LSO neurons were more numerous (76%) than inhibitory ones. A smaller proportion of inhibitory neurons were IC-projecting (45% vs. 64% for excitatory) suggesting that inhibitory LSO neurons may have more projections to other regions such the lateral lemniscus or more distributed IC projections. Inhibitory LSO neurons almost exclusively projected ipsilaterally making up a sizeable proportion (41%) of the transmitter type-labeled ipsilateral IC projection from LSO and exhibited a moderate low frequency bias (10% difference H-L). Two thirds of excitatory neurons projected contralaterally and had a slight high frequency bias (4%). One third of excitatory LSO neurons projected ipsilaterally to the IC and these cells were strongly biased toward the low frequency limb of the LSO (37%). This projection appears to be species specific in animals with good low frequency hearing suggesting that it may be a specialization for such ability.

Inferior collicular cells that project to the auditory thalamus are increasingly surrounded by perineuronal nets with age.

The age-related loss of GABA in the inferior colliculus (IC) likely plays a role in the development of age-related hearing loss. Perineuronal nets (PNs), specialized aggregates of extracellular matrix, increase with age in the IC. PNs, associated with GABAergic neurotransmission, can stabilize synapses and inhibit structural plasticity. We sought to determine whether PN expression increased on GABAergic and non-GABAergic IC cells that project to the medial geniculate body (MG). We used retrograde tract-tracing in combination with immunohistochemistry for glutamic acid decarboxylase and Wisteria floribunda agglutinin across three age groups of Fischer Brown Norway rats. Results demonstrate that PNs increase with age on lemniscal and non-lemniscal IC-MG cells, however two key differences exist. First, PNs increased on non-lemniscal IC-MG cells during middle-age, but not until old age on lemniscal IC-MG cells. Second, increases of PNs on lemniscal IC-MG cells occurred on non-GABAergic cells rather than on GABAergic cells. These results suggest that synaptic stabilization and reduced plasticity likely occur at different ages on a subset of the IC-MG pathway.

Early Physiological and Cellular Indicators of Cisplatin-Induced Ototoxicity.

Cisplatin chemotherapy often causes permanent hearing loss, which leads to a multifaceted decrease in quality of life. Identification of early cisplatin-induced cochlear damage would greatly improve clinical diagnosis and provide potential drug targets to prevent cisplatin's ototoxicity. With improved functional and immunocytochemical assays, a recent seminal discovery revealed that synaptic loss between inner hair cells and spiral ganglion neurons is a major form of early cochlear damage induced by noise exposure or aging. This breakthrough discovery prompted the current study to determine early functional, cellular, and molecular changes for cisplatin-induced hearing loss, in part to determine if synapse injury is caused by cisplatin exposure. Cisplatin was delivered in one to three treatment cycles to both male and female mice. After the cisplatin treatment of three cycles, threshold shift was observed across frequencies tested like previous studies. After the treatment of two cycles, beside loss of outer hair cells and an increase in high-frequency hearing thresholds, a significant latency delay of auditory brainstem response wave 1 was observed, including at a frequency region where there were no changes in hearing thresholds. The wave 1 latency delay was detected as early cisplatin-induced ototoxicity after only one cycle of treatment, in which no significant threshold shift was found. In the same mice, mitochondrial loss in the base of the cochlea and declining mitochondrial morphometric health were observed. Thus, we have identified early spiral ganglion-associated functional and cellular changes after cisplatin treatment that precede significant threshold shift.

The Density of Perineuronal Nets Increases With Age in the Inferior Colliculus in the Fischer Brown Norway Rat.

Age-related hearing loss, one of the most frequently diagnosed disabilities in industrialized countries, may result from declining levels of GABA in the aging inferior colliculus (IC). However, the mechanisms of aging and subsequent disruptions of temporal processing in elderly hearing abilities are still being investigated. Perineuronal nets (PNs) are a specialized form of the extracellular matrix and have been linked to GABAergic neurotransmission and to the regulation of structural and synaptic plasticity. We sought to determine whether the density of PNs in the IC changes with age. We combined Wisteria floribunda agglutinin (WFA) staining with immunohistochemistry to glutamic acid decarboxylase in three age groups of Fischer Brown Norway (FBN) rats. The density of PNs on GABAergic and non-GABAergic cells in the three major subdivisions of the IC was quantified. Results first demonstrate that the density of PNs in the FBN IC increase with age. The greatest increases of PN density from young to old age occurred in the central IC (67% increase) and dorsal IC (117% increase). Second, in the young IC, PNs surround non-GABAergic and GABAergic cells with the majority of PNs surrounding the former. The increase of PNs with age in the IC occurred on both non-GABAergic and GABAergic populations. The average density of PN-surrounded non-GABAergic cells increased from 84.9 PNs/mm2 in the young to 134.2 PNs/mm2 in the old. While the density of PN-surrounded GABAergic cells increased from 26 PNs/mm2 in the young to 40.6 PNs/mm2 in the old. The causality is unclear, but increases in PN density in old age may play a role in altered auditory processing in the elderly, or may lead to further changes in IC plasticity.

The current understanding of knowledge management concepts: A critical review.

Background: Higher education institutions include experts who are knowledgeable. Knowledge management facilitates institutions to enhance the capacity to collect information and knowledge and apply it to problem-solving and decision making. Through the review of related studies, we observed that there are multiple concepts and terms in the field of knowledge management. Thus, the complexity and variety of these concepts and definitions must be clarified. Considering the importance of clarifying these concepts for utilization by users, this study aimed to examine the concepts related to this filed. Methods: The methodology used in this study was based on the Carnwell and Daly's critical review method. An extensive search was carried out on various databases and libraries. A critical and profound review was carried out on selected articles. Many wandering concepts were found. Identified concepts were classified into seven categories based on conceptual proximity. Existing definitions and evidence in relation to extracted concepts were criticized and synthesized. The definitional attributes for them were identified and a conceptual identity card was provided for each of the concepts. Results: Thirty-seven concepts with the most relevance to the field of knowledge management were extracted. There was no clear boundary among them, and they wandered. To avoid more confusion, concepts were classified according to semantic relation. Eight categories were created; each category consisted of a mother concept and several other concepts with similarity and proximity to the meaning of the original concept. Their attributes have been identified, and finally, each of them was presented in the form of a conceptual identity card. Conclusion: Through critically reviewing the literature in this field, we were able to identify the concepts and realize their attributes. In this way, we came to a new interpretation of the concepts. At the end of the study, we concluded that some of the concepts have not been properly defined and are not properly located in the knowledge management field; also their application is uncertain.

Treatment of adult lead poisoning with D-penicillamine.

Background The aim of the current study was to evaluate the efficacy of D-penicillamine in the treatment of lead poisoning mainly in the outpatient setting. Methods In a case series study performed during the recent epidemic of lead poisoning in Iran, lead-poisoned patients referring to our outpatient clinic were treated with 250-mg D-penicillamine capsules administered every 6 h for 5 or 10 days based on availability of the medication. They were recommended to re-check blood lead level (BLL) 4 weeks after cessation of the treatment and refer to our clinic again. Results In 63 patients with lead poisoning but without signs and symptoms of lead encephalopathy, median BLL was 106 [84, 131] µg/dL on presentation, which declined to a mean of 52.6 ± 28.8 µg/dL after a median treatment period of 7 [5, 10] days (p < 0.001). There was no statistically significant difference between the 5- and 10-day treatment protocols regarding complications and recovery. Treatment had resulted in a median decrease of 54 µg/dL [33, 90] (range: -20 to 231 µg/dL) in the patients' BLLs (33.9% declined in BLL measurements; range: -29.69% to 99.06%). Conclusions D-penicillamine may be an acceptable substitute treatment in adult lead poisoning. Although our sample size was limited, we could not detect any serious adverse effects in our cases showing that D-penicillamine resulted in acceptable recovery rates. This may be helpful especially in epidemics with limitations in antidote access.

Assessment of the Effects of Inspiratory Muscle Training (IMT) and Aerobic Training on the Quality of Life of Patients with Chronic Obstructive Pulmonary Disease.

BACKGROUND: Chronic obstructive pulmonary disease (COPD) is a major cause of morbidity and mortality worldwide. The aim of this study was to investigate the effects of inspiratory muscle training (IMT) and aerobic exercise on health-related quality of life of patients with COPD. MATERIALS AND METHODS: This randomized controlled clinical trial was conducted on 60 patients with moderate to severe COPD, who were referred to Imam Hossein Hospital of Tehran, Iran in 2016. The patients were randomly assigned to four groups and treated for eight weeks. Group 1 (n=16) participated in 16 sessions of IMT (15 minutes per session), group 2 (n=14) performed aerobic exercises twice a week (40 minutes per session), group 3 (n=15) performed IMT and aerobic exercises, and group 4 (n=15) received no intervention, except for routine treatments (control). Quality of life was evaluated based on the Saint George's Respiratory Questionnaire (SGRQ) at baseline, week 4, and week 8 after the intervention. RESULTS: After eight weeks, all four groups experienced a significant improvement in their quality of life (P<0.05), and group 3 (IMT and aerobic exercise) showed the greatest improvement. However, quality of life improvement in group 4 (control) was less than the other three groups (P<0.05). CONCLUSION: Aerobic exercise and IMT were more effective than routine protocols in improving the quality of life of COPD patients. Furthermore, short-term IMT plus aerobic exercise had the greatest impact on improving the health-related quality of life of COPD patients and could be used in the management of these patients.

Ideal Soft Tissue Facial Profile in Iranian Males and Females: Clinical Implications.

BACKGROUND: Proper pre-operative facial analysis that includes a thorough evaluation of both the bony and soft tissue anatomy is paramount to success in performing aesthetic surgery of the face. Ethnic variations in soft tissue profile add an important variable to pre-operative facial analysis. The aim of our study was to determine the role of ethnic variations in soft tissue facial profiles through profile analysis of Iranian male and female patients. METHODS: Photographs of 100 Iranian males and 100 Iranian females (16 to 40 years old) were carried out. A review committee selected 10 male images and 10 female images, which they believed to be most ideal. The soft tissue profiles were then analyzed. A total of 21 measurements were analyzed and statistically compared with North American Caucasian males and females. RESULTS: The upper lip projection and lower lip projection were significantly more prominent in Iranian males as compared with North American Caucasian males. In addition, Iranian males had longer face as compared with North American Caucasian males along with a more drooping nasal tip. The frontonasal area is straighter and the lower face is longer in Iranian females compared with North American Caucasian in addition to more convex faces along with a shorter upper face. CONCLUSION: Significant differences in ideal soft tissue profiles exist between Iranian and Caucasian males. These differences should be recognized as they may play an important role in performing facial aesthetic and reconstructive procedures, particularly rhinoplasty, genioplasty, midface/facelifts, lip augmentation, and maxillofacial surgery.

Effect of Perioperative Management on Outcome of Patients after Craniosynostosis Surgery.

BACKGROUND: Craniosynostosis results from premature closure of one or more cranial sutures, leading to deformed calvaria and craniofacial skeleton at birth. Postoperative complications and outcome in intensive care unit (ICU) is related to surgical method and perioperative management. This study determined the perioperative risk factors, which affect outcome of patients after craniosynostosis surgery. METHODS: In a retrospective study, 178 patients with craniosynostosis who underwent primary cranial reconstruction were included. Postoperative complications following neurosurgical procedures including fever in ICU, level of consciousness, re-intubation, and blood, urine, and other cultures were also performed and their association with the main outcomes (length of ICU stay) were analyzed. RESULTS: Factors independently associated with a longer pediatric ICU stay were fever (OR=1.59, 95% CI=1.25-4.32; p=0.001), perioperative bleeding (OR=2.25, 95% CI=1.65-3.65; p=0.01), age (having surgery after the first 5 years) (OR=1.59, 95% CI=1.33-3.54, p=0.016) and infection (OR=2.17, 95% CI=1.83-7.46; p=0.002). Mean blood loss during surgery was significantly higher in patients whose duration of ICU was longer than 4 days compare to less than 4 day (p=0.026). Amount of bleeding significantly was correlated to duration of surgery (r=0.70, p=0.001) and patient's age (r=0.23, p=0.44). CONCLUSION: perioperative management particularly blood loss could deteriorate patients outcome and length of stay in ICU and hospital. Infections in ICU could deteriorate outcomes.

Time trend analysis and demographic features of inflammatory bowel disease in Tehran.

AIM: This retrospective study is aimed to review demographic and clinical characteristics of IBD to elucidate the probable factors associating with IBD development in Taleghani Hospital in Iran since 2001 during a 12-year-period. BACKGROUND: Ulcerative colitis (UC) and Crohn's disease (CD) are two major idiopathic entities of inflammatory bowel disease (IBD). Previous studies have reported an increased incidence of IBD in Middle East countries. PATIENTS AND METHODS: In the present study 1914 patients with UC, 318 patients with CD and 25 with indeterminate colitis (IC) were included. Demographic information, clinical features, extraintestinal manifestations, complications and extension of disease were collected and interpreted for all participants. According to the time of registration, patients were divided into seven groups. Statistical analysis was performed using the chi-square test. RESULTS: In seven groups of IBD patients, disease registry was estimated for UC, CD, and total IBD during a 12-year-period. From 2001 to 2005, a relative increased registry was observed among UC patients. However, in the years 2006 and 2007 a ​​significant reduction in the number of patients was reported. Then an increasing trend was observed in UC patients. UC presented mostly with diarrhea, hematochezia and bloody diarrhea, while most of CD patients complained of abdominal pain. CONCLUSION: Evaluation of data related to registered IBD patients in Iran shows that probable incidence and prevalence of IBD (UC and CD) is increasing compared to previous decades.

Diagnostic Value of Serum Levels of GFAP, pNF-H, and NSE Compared With Clinical Findings in Severity Assessment of Human Traumatic Spinal Cord Injury.

STUDY DESIGN: An analytical cohort study. OBJECTIVE: This study aimed to evaluate severity of traumatic spinal cord injury (SCI) based on the serum levels of phosphorylated form of heavy subunit of neurofilament (pNF-H), neuron-specific enolase (NSE), and glial fibrillary acidic protein (GFAP), which are axonal, neural cell body, and glial cell injury markers, respectively. SUMMARY OF BACKGROUND DATA: Prior studies have reported elevated serum levels of pNF-H, NSE, and GFAP as biomarkers for the detection of traumatic SCI in animals. However, in this study, these biomarkers were studied in humans and with an extended level of timing. METHODS: The study included 35 patients with SCI with a mean age of 36.5 years. All patients were evaluated using the American Spinal Injury Association Impairment Scale, followed by examinations including radiography and spinal computed tomography for determining the injury level. Serum levels of NSE, pNF-H, and GFAP were determined using enzyme-linked immunosorbent assay. RESULTS: The mean serum level of GFAP was significantly higher in patients with SCI than in the control group. Mean serum levels of pNF-H and NSE were significantly higher during 24 and 48 hours after injury in patients with SCI than in the control group. The serum level of GFAP was appropriate for estimating the severity of SCI in the first 24 hours after injury. CONCLUSION: Our findings suggest that increased serum levels of GFAP, NSE, and pNF-H can be used for the diagnosis and degree of SCI severity in trauma patients. During 48 hours after injury, estimation of serum levels of pNF-H, NSE, and GFAP, combined with neurological testing, could predict the presence of SCI and severity prior to spinal computed tomography and surgical or conservative interventions. LEVEL OF EVIDENCE: 2.

Application of fluorescent in situ hybridization in the mouse xenograft model of human fat grafting.

BACKGROUND: Determining the optimal technique for autologous fat grafting requires elucidation of the engraftment process at the cellular level. The nude mouse xenograft model for autologous human fat grafting is an excellent tool to evaluate the incorporation of grafted fat into the recipient. OBJECTIVES: The authors present a murine xenograft model that uses fluorescent in situ hybridization (FISH) to differentiate between murine (host) cells and human (grafted) cells. METHODS: Fat grafts were harvested from human abdominoplasty specimens, fixed, embedded in paraffin blocks, and cut into 5 µm sections. The sections were stained and used for in situ hybridization with fluorescently labeled murine and human nucleic acid reagents. A fluorescence microscope was used for photographic analysis of the grafts, allowing identification of murine and human cell populations based on the wavelength at which they stained. DAPI (4,'6-diamidino-2-phenylindole) counterstaining was also applied to confirm that the images obtained represented cell nuclei. RESULTS: At 20× magnification, strong species-specific staining of cells was seen within the tissue sections, which allowed the authors to easily discriminate between graft-derived and host-derived cells. Using this approach, human fat xenografts were revealed to comprise a complex matrix of closely interacting graft- and host-derived structures. CONCLUSIONS: FISH has the potential to be a powerful technique for distinguishing between murine and human cells in the nude mouse xenograft model of human fat grafting. By applying this technique, it may be possible to evaluate the engraftment process at a cellular level, which may ultimately allow clinicians to obtain more predictable results with grafted fat.