Search Results (249)

Background/Objectives: To evaluate the clinical feasibility, safety, and geometric characteristics of a supine CT-guided posterior approach using a custom dorsal-space mat in patients for whom the supine position was required or preferred. Methods: This retrospective study included 16 consecutive patients prepared for the approach. Puncture trajectory parameters, positional stability, technical success, procedure time, and adverse events were evaluated in successfully positioned patients (n = 15; 35 trajectories). A geometric model was constructed to estimate maximum allowable puncture angles determined by mat height, needle length, and table geometry. Results: Positioning feasibility was 15/16 (93.8%); one patient was converted to a lateral approach due to shoulder pain. Technical success was 100% per patient (15/15) and per trajectory (35/35). The mean puncture angle and depth were 40.2° ± 9.1° and 8.3 ± 2.5 cm, respectively. All puncture angles were within theoretical geometric limits, with a mean angular margin of 14.9° ± 10.9°. Quantitative stability assessment was feasible in 14 patients; median two-dimensional displacement and absolute axial rotation were 4.1 mm (IQR, 3.3–4.5 mm) and 0.9° (IQR, 0.3–1.2°), respectively. Between-group differences observed in the trajectory-level analysis were not statistically significant in the patient-level sensitivity analysis. One Grade 5 adverse event occurred after RFA; although a relationship with the procedure could not be excluded, it was unrelated to the mat or puncture trajectory. Conclusions: This preliminary feasibility study suggests that the dorsal-space mat can provide sufficient working space for CT-guided posterior procedures while maintaining the supine position. Larger prospective studies are required to establish its broader clinical applicability and safety. Full article

Background/Objectives: Dental needles are used routinely for local anaesthesia, but repeated insertion, needle selection, and operator handling may all compromise tip integrity. This study assessed bevel deformation, biological debris, and manual bending in used dental needles collected during undergraduate clinical practice. Their associations with needle dimensions, insertion frequency, injection technique, and operator seniority were also examined. Methods: 192 discarded needles were collected from fourth-, fifth-, and sixth-year students and dental interns after routine local anaesthesia procedures at an academic dental hospital. Each needle was examined under stereomicroscopy. Needle bevels were classified as intact, outward bending, or inward bending; biological debris and manual bending were also recorded. Predictors of bevel deformation were identified by multivariable logistic regression. Results: Bevel deformation was present in 93 of 192 needles. Thirty-gauge needles showed higher odds of deformation than 27-gauge needles (OR = 2.54, p = 0.004), and each additional insertion further increased the odds (OR = 1.98, p = 0.016); once gauge was accounted for, needle length was not an independent predictor. Intended bone contact showed no association with deformation. Outward bending predominated among deformed tips (63.4% vs. 36.6% inward), and biological debris was detected on 16.1% of needles. Manual bending was more frequent among interns than students (OR = 3.67, p = 0.007). Conclusions: Used dental needles frequently exhibited bevel deformation, particularly with 30-gauge needles and after repeated insertions. The occurrence of deformation even in the absence of intentional bone contact further supports strict single-use practices and careful needle handling during local anaesthesia. Although the higher frequency of manual needle bending observed among interns should be interpreted cautiously, this finding highlights a potential area for targeted operator training and further investigation. Full article

Background/Objectives: Endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) can be performed via pathways that differ in anesthesia, setting, airway management, monitoring, recovery, and hospitalization. We compared an outpatient endoscopy suite pathway with sedation and spontaneous breathing, and an operating room pathway with general anesthesia and laryngeal mask ventilation, assessing cytology-based yield, sample adequacy, workflow, and costs. Methods: This single-center observational study included consecutive EBUS-TBNA procedures. Allocation was nonrandom and reflected workflow, operating room availability, complexity, airway/anesthetic considerations, and judgment. The primary endpoint was cytology-based diagnostic yield in the diagnostic cohort; staging outcomes included cytology distribution, sample adequacy, and positivity among adequate samples. Systematic diagnostic verification was not available for the entire cohort; however, postoperative nodal pathology was retrospectively retrieved when available in the staging cohort. Because verification remained incomplete and selectively available, sensitivity, specificity, negative predictive value, and overall diagnostic accuracy were not estimated. Results: Clinical outcome analyses included 447 procedures (319 diagnostic and 128 staging), while the administrative cost dataset included 533 completed procedures. Diagnostic yield was similar between pathways (108/229, 47.2% vs. 45/90, 50.0%; p = 0.740). In the staging cohort, sample adequacy was comparable (83/85, 97.6% vs. 39/42, 92.9%; p = 0.331), and positivity among adequate samples did not differ (21.7% vs. 20.5%; p = 1.000). Exploratory postoperative pathological nodal-stage data were available for 60/128 staging procedures; among 58 cases with interpretable EBUS-TBNA results, patient-level N-stage concordance was 44/58 (75.9%), and postoperative nodal upstaging occurred in 11/58 (19.0%). No prespecified intraprocedural composite adverse events were documented. Duration appeared shorter in operating room cases but, owing to incomplete differential recording, was descriptive only. Length of stay and costs were markedly higher in the operating room pathway. Conclusions: The pathways showed similar cytology-based outcomes but differed in hospitalization rates and costs. Nonrandom allocation and pathway heterogeneity preclude causal interpretation as a sedation-versus-general-anesthesia comparison. Prospective studies with standardized allocation, diagnostic verification, systematic capture of adverse events, and follow-up are warranted. Full article

Background/Objectives: Androgenetic alopecia (AGA) is the most prevalent form of hair loss. Although topical minoxidil (MNX) is widely used to treat AGA, its efficacy is limited by poor penetration across the stratum corneum. This study evaluated radiofrequency (RF) microporation as a means of enhancing cutaneous MNX delivery and hair-regrowth efficacy in a dihydrotestosterone (DHT)-induced AGA mouse model. Methods: RF-induced skin permeabilization and barrier recovery were assessed in rats using methylene blue and rhodamine B staining. In vivo skin deposition and pharmacokinetic studies were conducted to quantify cutaneous MNX accumulation and systemic exposure. Hair-regrowth efficacy was evaluated in DHT-treated mice. Results: RF microporation generated transient microchannels in the stratum corneum, increased rhodamine B penetration into deeper skin layers, and allowed substantial barrier recovery within 24 h. RF pretreatment significantly increased MNX deposition in the epidermis/dermis by 2.40-fold at 1 h and 1.94-fold at 3 h compared with topical MNX alone. RF-assisted topical administration resulted in a relative bioavailability of 11.17%, compared with 4.74% for topical administration without RF, while dose-normalized systemic exposure remained substantially lower than that following oral administration. In the AGA model, RF-assisted MNX treatment significantly increased hair coverage, length, and shaft thickness. Histological analysis further showed more prominent follicular structures in the RF-assisted MNX groups. Conclusions: RF microporation creates transient microchannels that enhance cutaneous MNX delivery and improve hair-regrowth efficacy. Importantly, RF-assisted topical administration maintained substantially lower systemic exposure than oral administration, supporting its potential as a needle-free strategy for topical AGA therapy and further translational evaluation. Full article

This response letter addresses criticisms from a recent commentary regarding a real-world survey on insulin pen needle preferences. The authors clarify that their study was purposefully designed as an observational survey to capture genuine patient perceptions under routine clinical conditions, rather than functioning as a randomized controlled trial. Consequently, methodological constraints such as blinding were fundamentally inapplicable. Furthermore, the authors emphasize the limited relevance of the Hawthorne effect in this context. While originally described in industrial settings, recent systematic reviews in the medical literature indicate that its magnitude and impact on modern clinical research are highly uncertain and generally modest. Ultimately, the study effectively highlights real-world patient experiences with the shortest and thinnest needles currently available, aligning with advances in injection technology. Full article

Needle roller bearings are characterized by rolling elements with relatively high length-to-diameter ratios and are widely used in mechanical systems with limited radial installation space. In gear transmission systems, periodic impact loads induced by gear meshing may be superimposed on steady radial loads, thereby altering the dynamic response of the bearing. However, the effects of the amplitude and frequency of periodic impact loading on the dynamic characteristics of needle roller bearings remain insufficiently understood. In this study, a needle roller bearing test rig capable of applying periodic impact loading was developed, and a multi-sensor measurement system was configured to measure outer-ring vibration, inner-ring motion, cage motion, and the friction torque of the bearing system. Dynamic tests were conducted under different amplitudes and frequencies of periodic impact loading. A reduction in bearing motion stability was observed under periodic impact loading, as evidenced by increased outer-ring vibration and enlarged cage motion in both the horizontal and vertical directions. As the loading amplitude increased, the RMS values of outer-ring acceleration, inner-ring displacement, and cage displacement increased, while an increase in the mean friction torque was also observed. The inner-ring trajectory expanded along the loading direction, and the whirling range of the cage trajectory increased. As the loading frequency increased, the RMS values of outer-ring acceleration, inner-ring displacement, and cage displacement increased, and the mean friction torque increased. In contrast, the whirling range of the cage trajectory decreased. These findings clarify the distinct effects of periodic impact-loading amplitude and frequency on bearing vibration, internal motion, and friction-torque characteristics and provide experimental support for the dynamic performance evaluation of needle roller bearings under impact conditions. Full article

Objectives: To compare the geometric design, metallurgical properties, mechanical performance, and irrigation dynamics of Reciproc Minima (M20 and M25) and Reciproc Blue R25 instruments. Methods: One hundred and eighty instruments (n = 60/group) were evaluated. Geometry was analyzed using stereomicroscopy, scanning electron microscopy, and 3D surface scanning. Metallurgical characteristics were assessed by energy-dispersive X-ray spectroscopy and differential scanning calorimetry. Mechanical performance tests (n = 10/group) included cyclic fatigue, torsional resistance, bending resistance, buckling resistance, and cutting efficiency. Irrigation dynamics were examined through computational fluid dynamics simulations based on a micro-CT-derived mandibular molar model prepared according to each system and combined with open-ended, side-vented, or double side-vented needles. Data were analyzed using one-way ANOVA or Kruskal–Wallis tests (α = 0.05). Results: The results showed that blade dimensions increased progressively from Minima M20 to Reciproc Blue R25. All instruments had S-shaped cross-sections and non-active tips. Energy-dispersive spectroscopy confirmed near-equiatomic NiTi composition, and similar phase transformation temperatures were observed across groups. Minima M20 showed the highest cyclic fatigue resistance (p < 0.0001), whereas Minima R25 exhibited greater angular deflection (p < 0.0001). Reciproc Blue R25 had the highest buckling resistance and lowest flexibility (p < 0.0001). M25 showed the lowest axial force, indicating the numerically highest cutting efficiency, but it did not differ significantly from Reciproc Blue R25 (p > 0.05). No needle delivered irrigant to working length. The open-ended needle achieved greater apical penetration, particularly with Reciproc Blue R25. Minima M20 generated the highest wall shear stress, and Reciproc Blue R25 the lowest apical pressure. Conclusions: Reciproc Minima and Reciproc Blue R25 showed similar metallurgical characteristics; however, differences in geometric design resulted in distinct mechanical behaviors and irrigation fluid dynamics. These findings suggest that low-taper reciprocating instruments may represent a conservative alternative in anatomically challenging canals, while clinicians should consider the associated differences in mechanical behavior and irrigation dynamics when selecting the most appropriate instrument. Full article

Aquaculture production of Asian seabass is increasingly threatened by recurrent bacterial diseases, while practical vaccination strategies that provide protection against bacterial challenges involving multiple pathogens during extended grow-out periods remain limited. This study evaluated the immunological and protective effects of a sequential mucosal vaccination strategy in juvenile Asian seabass (Lates calcarifer; 200 fish per treatment, distributed among four replicate tanks of 50 fish) against four major bacterial pathogens: Flavobacterium covae, Vibrio harveyi, Vibrio vulnificus, and Photobacterium damselae. The vaccination regimen consisted of two nanoemulsion-based immersion vaccination events administered 14 days apart, followed by three oral chitosan–alginate hydrogel vaccination courses administered for 7, 5, and 3 consecutive days. Bacterial challenge experiments were conducted at three post-vaccination time points using immersion and intraperitoneal injection models. Growth performance and feed conversion were evaluated using replicate-tank means as the experimental units. Sequential vaccination did not significantly affect final body weight, weight gain, average daily gain, specific growth rate, or feed conversion ratio (p > 0.05). Vaccinated fish showed significantly higher antigen-specific IgM levels in skin mucus, intestinal mucus, and serum across the evaluated challenge conditions. Correspondingly, ighm, ighd, and ight expression was increased in the gills, skin, head kidney, and intestine, indicating enhanced immunoglobulin-associated responses in mucosal and lymphoid tissues. Full-length 16S rRNA gene sequencing showed vaccine-associated changes in gill and intestinal bacterial community composition, including a lower relative representation of several challenge-associated taxa and a higher relative representation of selected commensal-associated taxa. Vaccinated fish showed significantly higher cumulative survival following F. covae immersion, mixed V. harveyi/V. vulnificus/P. damselae immersion, and mixed-pathogen injection challenges (p < 0.05). These findings demonstrate that sequential nanoemulsion immersion priming and oral hydrogel boosting enhanced pathogen-specific humoral responses and increased immunoglobulin-gene expression. The sequential vaccination strategy improved survival following a separate Flavobacterium covae challenge and a combined Vibrio harveyi/Vibrio vulnificus/Photobacterium damselae challenge during the experimental period without adversely affecting growth. This needle-free strategy warrants further evaluation under commercial aquaculture conditions. Full article

Background: The optimal needle for endoscopic ultrasound (EUS)-guided liver biopsy (LB) remains uncertain. Methods: We conducted a network meta-analysis that integrated both direct and indirect comparisons among various needles. Our analysis included five randomized controlled trials (RCTs) involving 251 patients, which compared 19G fine-needle aspiration (FNA), 19G Franseen fine-needle biopsy (FNB), 19G Fork-tip FNB, 22G Franseen FNB, and 22G Fork-tip FNB. The primary outcomes focused on the total specimen length and the number of complete portal tracts (CPTs). Results were presented as mean difference (MD) or risk ratio (RR) with 95% confidence intervals (CIs). Results: The 19G Fork-tip and 19G Franseen needles were found to be significantly superior to the others in terms of total specimen length and CPT count. No differences were observed between the 19G FNA and the 22G Franseen or Fork-tip needles. SUCRA ranking indicated that the 19G Franseen and 19G Fork-tip FNB were the top-performing needles, with SUCRA scores of 0.91 and 0.83 for specimen length, and 0.85 and 0.82 for CPTs. No severe adverse events were reported. The quality of evidence was generally considered low due to bias risk and imprecision. Conclusions: The 19G Franseen and Fork-tip FNB showed favorable results but further RCTs are needed to confirm these results. Full article

Background/Objectives: The superficial radial nerve (SRN) is highly susceptible to iatrogenic injury during wrist injection procedures. This study aimed to identify the anatomical trajectory of the SRN using high-resolution ultrasonography and to establish a reliable “safe zone” for wrist extensor compartment injections. Methods: Fifty-eight forearms from 29 healthy volunteers (15 males, 14 females) were evaluated. Four anatomical levels were defined: the proximal and distal ends of the extensor compartment I-II intersection area (Levels A and B), and the proximal and distal points of SRN crossing over the first compartment (Levels C and D). Longitudinal distances from the radial styloid, horizontal distances and depths of the SRN were measured. Generalized Estimating Equations (GEEs) were used to analyze the relationship between total forearm length and the longitudinal position of each landmark. Results: Total forearm length was significantly associated with proximal landmarks, La (B = 0.205, p < 0.001) and Lc (B = 0.105, p < 0.001). Although Lb also showed a significant association (B = 0.071, p = 0.019), its absolute variation was minimal. The most distal landmark Ld (B = −0.023, p = 0.610) exhibited no significant relationship. For intersection syndrome, a safe injection corridor was identified between 24.1% and 12.7% of forearm length (Level A to C), where a proximal-to-distal and dorsal-to-volar needle direction is recommended, as the SRN lies volar at this level. For De Quervain’s tenosynovitis, a volar-to-dorsal needle direction at or distal to 0.8 cm from the radial styloid (Level D) minimizes nerve contact risk. Conclusions: This study suggests a differentiated, landmark-based approach for wrist injections: utilizing proportional ratios for proximal landmarks and fixed absolute distances for distal landmarks. This individualized guide is expected to enhance procedural safety and minimize the risk of iatrogenic SRN injury. Full article

In this work, based on a half-bridge circuit and pulse transformer, a miniaturized and low-cost microsecond high-voltage pulsed power supply for the atmospheric pressure plasma jet (APPJ) is designed. Because of the low bus voltage of the half-bridge circuit, low-voltage switches can be chosen by the power supply. The characteristics of the output high voltage of the power supply are studied. The experimental results show that uni-polar and bi-polar pulses can be generated by the power supply. The high-voltage pulses have good consistency at different frequencies, and the amplitude of the high-voltage pulse varies approximately linearly with the bus voltage. A needle-ring plasma jet device was driven by the uni-polar pulse of this supply, and the single discharge current pulse can be obtained at the rising edge and falling edge of the high-voltage pulse, respectively. The effects of voltage pulse on APPJ and the characteristics of jet are also investigated. The results show that the plasma jet is only formed at the rising edge of the voltage pulse. The jet length is almost unaffected by the pulse frequency, whereas the normalized intensity of most species increases with frequency linearly. Full article

A recently identified mesenchymal cell population, telocytes (TCs), has been found in many tissues of different animal species. Jet needle-free injection (JNFI) is a promising non-invasive drug-delivery method that can trigger effective immune responses in the skin. In this preliminary morphological study, an inactivated porcine circovirus vaccine was delivered into pig neck skin by JNFI, and untreated normal neck skin served as the control. Histopathology, immunohistochemistry (IHC), immunofluorescence (IF), and transmission electron microscopy (TEM) were used to evaluate TC distribution, ultrastructure, and selected quantitative TEM parameters 24 h after injection. TCs were widely distributed in porcine skin, located between collagen fibers and around blood vessels, adipocytes, and sweat glands. They were also observed in contact with mast cells. TCs around sweat glands were CD34⁺, Vimentin⁺, and α-SMA⁺, whereas TCs at other sites were CD34⁺, Vimentin⁺, and α-SMA⁻. After JNFI, inflammatory cell infiltration into the skin was observed; TCs were in contact with these cells, and TCs surrounding adipocytes redistributed into the adjacent loose connective tissue. Quantitative TEM analysis showed that TC profile density and visible telopod length did not differ significantly between normal skin and JNFI 24 h skin (p ≥ 0.05). In contrast, vesicle profiles per TC increased significantly in both perivascular and adipose-associated compartments (p < 0.05). These findings provide morphological evidence suggesting that TCs may participate in early cutaneous responses after JNFI vaccine delivery. Full article

Background/Objectives: An incorrect intradeltoid injection technique can cause shoulder injury related to vaccine administration, including bursitis, septic arthritis, and axillary nerve injury, particularly when Western-derived landmarks and needle-length tables are applied to smaller-framed Southeast Asian adults. We aimed to define an individualized deltoid injection landmark and needle length that avoid the axillary nerve while ensuring reliable intramuscular delivery in Southeast Asian adults. Methods: In this cross-sectional ultrasound study of adults aged ≥18 years, four vertical landmarks below the acromion (individual contralateral 2-fingerbreadth (FB), individual contralateral 3-FB, average 2-FB, average 3-FB) were assessed in two arm positions (adduction and approximately 30° abduction with the hand on the waist). For each combination, we recorded the presence of the axillary nerve and measured skin-to-subcutaneous and deltoid muscle thickness to estimate whether 0.5-, 1-, or 1.5-inch needles would terminate within muscle or penetrate the subdeltoid bursa. Results: Eighty-two participants (39 males, 43 females) were included. The axillary nerve was not visualized at the individualized contralateral 2-FB landmark in adduction but was present at 31.7–50.0% of other landmark–position combinations. At the individualized 2-FB site in adduction, mean skin-to-subcutaneous thickness was <12.7 mm and mean skin-to-subdeltoid fascia distance exceeded 12.7 mm in all strata, implying that a 0.5-inch needle would consistently terminate within the deltoid muscle. Conclusions: In Southeast Asian adults, the contralateral individualized 2-FB landmark in arm adduction provides a neurovascularly safe window for intradeltoid vaccination, and a 0.5-inch needle offers reliable intramuscular delivery while minimizing the risk of bursal penetration. Full article

Background: Cellulite is a highly prevalent aesthetic concern characterized by structural remodeling of subcutaneous adipose tissue and fibrous septa, resulting in visible skin irregularities. Despite the availability of many injectable treatments with documented efficacy, most standard approaches adopt uniform protocols that overlook interindividual anatomical variability, potentially limiting treatment precision and clinical outcomes. This retrospective case–control study evaluated the Modulated Insertion of Regenerative Activation (MIRA), a technique that individualizes needle length and injection angle according to ultrasound findings, modulating insertion parameters to stimulate regenerative responses within dermal and subcutaneous layers. Methods: Clinical and ultrasonographic data from 120 women with stage 3 cellulite were analyzed over a 30-day follow-up period. Stage 3A patients received carbon dioxide therapy (CDT), whereas stage 3B patients underwent injectable solution therapy (IST). Within each treatment, patients were allocated to MIRA or control groups. Results: Compared with controls, MIRA showed greater reductions in adipose tissue thickness (CDT: −1.6 mm; IST: −1.5 mm; p_adj = 0.002), nodules, pain, edema, and fibrosis, with improved fascia regularity. Patient satisfaction was higher in MIRA (CDT: 8.1 ± 1.6; IST: 8.5 ± 1.4; p_adj = 0.002), and over 76% reported improved skin quality. Conclusions: These explorative findings suggest that ultrasound-guided modulation of needle parameters with MIRA may enhance structural and esthetic outcomes compared with standard approaches. Prospective randomized trials are needed to confirm these results. Full article

Background: Epidural procedures benefit from a pre-procedural informed estimation of epidural depth, as anticipating the approximate distance can support safer needle placement and reduce technical difficulties during analgesia or anesthesia procedures. The influence of ethnicity has been established across different populations worldwide; however, there is a lack of Saudi-specific MRI data on epidural depth among the adult population. Aim of this Study: To measure the skin to epidural space distance (SED) at the lumbar interspaces L3–L4 and L4–L5 in the Saudi adult population using magnetic resonance imaging (MRI) and to examine its correlations with age, sex, height, weight, and body mass index (BMI). Methods: In this retrospective cross-sectional study, sagittal T1-weighted lumbar MRI images of the spine of 169 adult Saudi patients were studied. The age group ranged from 20 to 70 years, with an equal distribution of males and females. The skin to epidural space distance (SED) was measured at the L3–L4 and L4–L5 interspaces, and its correlations with age, sex, height, weight, and BMI were analyzed. Results: The average measurement of skin to epidural space distance (SED) was 59.08 mm in L3–L4, and 63.21 in L4–L5. BMI and weight showed strong positive correlations with SED across both levels. Female sex was associated with longer SED values at L4–L5. There was no significant correlation between SED and age or height of the patients. Conclusions: MRI-based assessment of SED revealed strong correlations with weight and BMI, but no correlation with height, age, and sex. These findings support the individualized estimation of epidural depth and needle length selection to enhance procedural safety and reduce complications. Full article