A multi-cohort genome-wide association study in African ancestry individuals reveals risk loci for primary open-angle glaucoma.

Primary open-angle glaucoma (POAG), the leading cause of irreversible blindness worldwide, disproportionately affects individuals of African ancestry. We conducted a genome-wide association study (GWAS) for POAG in 11,275 individuals of African ancestry (6,003 cases; 5,272 controls). We detected 46 risk loci associated with POAG at genome-wide significance. Replication and post-GWAS analyses, including functionally informed fine-mapping, multiple trait co-localization, and in silico validation, implicated two previously undescribed variants (rs1666698 mapping to DBF4P2; rs34957764 mapping to ROCK1P1) and one previously associated variant (rs11824032 mapping to ARHGEF12) as likely causal. For individuals of African ancestry, a polygenic risk score (PRS) for POAG from our mega-analysis (African ancestry individuals) outperformed a PRS from summary statistics of a much larger GWAS derived from European ancestry individuals. This study quantifies the genetic architecture similarities and differences between African and non-African ancestry populations for this blinding disease.

Resistance of HIV-infected macrophages to CD8+ T lymphocyte-mediated killing drives activation of the immune system.

CD4+ T lymphocytes are the principal target of human immunodeficiency virus (HIV), but infected macrophages also contribute to viral pathogenesis. The killing of infected cells by CD8+ cytotoxic T lymphocytes (CTLs) leads to control of viral replication. Here we found that the killing of macrophages by CTLs was impaired relative to the killing of CD4+ T cells by CTLs, and this resulted in inefficient suppression of HIV. The killing of macrophages depended on caspase-3 and granzyme B, whereas the rapid killing of CD4+ T cells was caspase independent and did not require granzyme B. Moreover, the impaired killing of macrophages was associated with prolonged effector cell-target cell contact time and higher expression of interferon-γ by CTLs, which induced macrophage production of pro-inflammatory chemokines that recruited monocytes and T cells. Similar results were obtained when macrophages presented other viral antigens, suggestive of a general mechanism for macrophage persistence as antigen-presenting cells that enhance inflammation and adaptive immunity. Inefficient killing of macrophages by CTLs might contribute to chronic inflammation, a hallmark of chronic disease caused by HIV.

Functional impairment of HIV-specific CD8+ T cells precedes aborted spontaneous control of viremia.

Spontaneous control of HIV infection has been repeatedly linked to antiviral CD8+ T cells but is not always permanent. To address mechanisms of durable and aborted control of viremia, we evaluated immunologic and virologic parameters longitudinally among 34 HIV-infected subjects with differential outcomes. Despite sustained recognition of autologous virus, HIV-specific proliferative and cytolytic T cell effector functions became selectively and intrinsically impaired prior to aborted control. Longitudinal transcriptomic profiling of functionally impaired HIV-specific CD8+ T cells revealed altered expression of genes related to activation, cytokine-mediated signaling, and cell cycle regulation, including increased expression of the antiproliferative transcription factor KLF2 but not of genes associated with canonical exhaustion. Lymphoid HIV-specific CD8+ T cells also exhibited poor functionality during aborted control relative to durable control. Our results identify selective functional impairment of HIV-specific CD8+ T cells as prognostic of impending aborted HIV control, with implications for clinical monitoring and immunotherapeutic strategies.

CCK+ Interneurons Contribute to Thalamus-Evoked Feed-Forward Inhibition in the Prelimbic Prefrontal Cortex.

Interneurons in the medial prefrontal cortex (PFC) regulate local neural activity to influence cognitive, motivated, and emotional behaviors. Parvalbumin-expressing (PV+) interneurons are the primary mediators of thalamus-evoked feed-forward inhibition across the mouse cortex, including the anterior cingulate cortex, where they are engaged by inputs from the mediodorsal (MD) thalamus. In contrast, in the adjacent prelimbic (PL) cortex, we find that PV+ interneurons are scarce in the principal thalamorecipient layer 3 (L3), suggesting distinct mechanisms of inhibition. To identify the interneurons that mediate MD-evoked inhibition in PL, we combine slice physiology, optogenetics, and intersectional genetic tools in mice of both sexes. We find interneurons expressing cholecystokinin (CCK+) are abundant in L3 of PL, with cells exhibiting fast-spiking (fs) or non-fast-spiking (nfs) properties. MD inputs make stronger connections onto fs-CCK+ interneurons, driving them to fire more readily than nearby L3 pyramidal cells and other interneurons. CCK+ interneurons in turn make inhibitory, perisomatic connections onto L3 pyramidal cells, where they exhibit cannabinoid 1 receptor (CB1R) mediated modulation. Moreover, MD-evoked feed-forward inhibition, but not direct excitation, is also sensitive to CB1R modulation. Our findings indicate that CCK+ interneurons contribute to MD-evoked inhibition in PL, revealing a mechanism by which cannabinoids can modulate MD-PFC communication.

Micro-Acoustic Holograms for Detachable Microfluidic Devices.

Acoustic microfluidic devices have advantages for diagnostic applications, therapeutic solutions, and fundamental research due to their contactless operation, simple design, and biocompatibility. However, most acoustofluidic approaches are limited to forming simple and fixed acoustic patterns, or have limited resolution. In this study,a detachable microfluidic device is demonstrated employing miniature acoustic holograms to create reconfigurable, flexible, and high-resolution acoustic fields in microfluidic channels, where the introduction of a solid coupling layer makes these holograms easy to fabricate and integrate. The application of this method to generate flexible acoustic fields, including shapes, characters, and arbitrarily rotated patterns, within microfluidic channels, is demonstrated.

Clinical Investigation of Large Volume Subcutaneous Delivery up to 25 mL for Lean and Non-Lean Subjects.

PURPOSE: To evaluate the clinical feasibility and tolerability of large volume subcutaneous delivery at different injection depths for lean and non-lean subjects. METHODS: A single-center, randomized, subject-blinded, crossover study in 62 healthy subjects was conducted to evaluate delivery of a 10-cP solution containing hyaluronic acid. Subjects were separated into lean and non-lean cohort by SC thickness. A syringe pump was used to study the effect of different volumes (5, 12, 25 mL) of a viscous placebo solution and needle lengths (6, 9 and 12 mm) delivered at 0.5 mL/min. RESULTS: Across all treatments, injection sites were observed to have negligible leakage, ~34 kPa of back pressure, and VAS of mild pain with higher pain from needle insertion than during injection. While mild to moderate erythema was the most frequently reported ISR and edema was most prominent for 25 mL injections, all ISRs were resolved within 4 hours post injection. Subjects were unbothered by ISRs across all treatments and rated them as low distress scores (average 1.0-1.5 out of 6). CONCLUSION: SC injection of 25 mL is feasible and tolerable using a low-pain formulation for abdomen injection irrespective of subcutaneous thickness and injection depths at a delivery rate of 0.5 mL/min.

Providers and women's perspectives on opportunities, challenges and recommendations to improve cervical cancer screening in women living with HIV at Mbarara Regional Referral Hospital: a qualitative study.

BACKGROUND: Cervical cancer screening uptake remains low despite being a critical prevention method for adult women living with HIV(WLHIV). These women experience greater incidence and persistence of high-risk human papillomavirus (HPV) and severe outcomes, including cervical cancer comorbidity and death. OBJECTIVE: We explored the opportunities, challenges, and recommendations of clinical care providers and WLHIV to improve cervical cancer screening uptake among WLHIV in Southwestern Uganda. METHODS: In a cross-sectional qualitative study from January to June 2021 at Mbarara Regional Referral Hospital, we interviewed six key informant clinical care providers and held four focus group discussions with women living with HIV. Data was coded using Atlas ti software and analysed using thematic inductive analysis. RESULTS: The participants identified several prevailing opportunities for cervical cancer screening, including skilled clinical care workers, public awareness for demand creation, optimized clinic flow, provider-led referrals, and peer-led information sharing that ease clinic navigation and shorten participant throughput. However, challenges occurred due to standalone services resulting in double queuing, longer clinic visit hours, missed chances for screening alongside unsupported lower health facilities leading to crowding at the referral hospital, and inadequate patient privacy measures leading to shame and stigma and the misconception that cervical cancer is incurable. Integrating HPV-DNA testing in HIV services was perceived with ambivalence; some participants worried about the quality of sample collection, while others valued the privacy it offered. Optimising self-collected DNA testing and sufficient counselling were recommended to improve cervical cancer screening uptake. CONCLUSION: Opportunities for cervical cancer screening included trained clinical care professionals, increased public awareness, improved clinic flow, provider referrals, and peer education. Challenges, such as unsupported lower-level health facilities, misconceptions, inadequate patient privacy, and uncertainty about integrating HPV-DNA screening into HIV services, were cited. Adequate counselling and self-sample collection were recommended to foster screening. Our findings may guide healthcare programs integrating cervical cancer screening into HIV clinics to reach the 70% World Health Organisation targets by 2030.

Costs of reproduction are present but latent in eusocial bumblebee queens.

BACKGROUND: The standard evolutionary theory of ageing proposes that ageing occurs because of a trade-off between reproduction and longevity. Eusocial insect queens exhibit positive fecundity-longevity associations and so have been suggested to be counter-examples through not expressing costs of reproduction and through remodelling conserved genetic and endocrine networks regulating ageing and reproduction. If so, eusocial evolution from solitary ancestors with negative fecundity-longevity associations must have involved a stage at which costs of reproduction were suppressed and fecundity and longevity became positively associated. Using the bumblebee (Bombus terrestris), we experimentally tested whether queens in annual eusocial insects at an intermediate level of eusocial complexity experience costs of reproduction, and, using mRNA-seq, the extent to which they exhibit a remodelling of relevant genetic and endocrine networks. Specifically, we tested whether costs of reproduction are present but latent, or whether a remodelling of relevant genetic and endocrine networks has already occurred allowing queens to reproduce without costs. RESULTS: We experimentally increased queens' costs of reproduction by removing their eggs, which caused queens to increase their egg-laying rate. Treatment queens had significantly reduced longevity relative to control queens whose egg-laying rate was not increased. Reduced longevity in treatment queens was not caused by increased worker-to-queen aggression or by increased overall activity in queens. In addition, treatment and control queens differed in age-related gene expression based on mRNA-seq in both their overall expression profiles and the expression of ageing-related genes. Remarkably, these differences appeared to occur principally with respect to relative age, not chronological age. CONCLUSIONS: This study represents the first simultaneously phenotypic and transcriptomic experimental test for a longevity cost of reproduction in eusocial insect queens. The results support the occurrence of costs of reproduction in annual eusocial insects of intermediate social complexity and suggest that reproductive costs are present but latent in queens of such species, i.e. that these queens exhibit condition-dependent positive fecundity-longevity associations. They also raise the possibility that a partial remodelling of genetic and endocrine networks underpinning ageing may have occurred in intermediately eusocial species such that, in unmanipulated conditions, age-related gene expression depends more on chronological than relative age.

Bacterial isolates and antibiotic susceptibility among women with abnormal vaginal discharge attending the gynecology clinic at a tertiary hospital in southwestern Uganda: a cross-sectional study.

BACKGROUND: Abnormal vaginal discharge is a common complaint among women of reproductive age, affecting about one- third of all women. In resource-limited settings where access to laboratory services is limited, treatment is usually syndromic. This approach may result in ineffective treatment, with high recurrence rates and a potential of developing antibiotic resistance. This study aimed to determine the bacterial isolates and antibiotic susceptibility among women with an abnormal vaginal discharge attending the gynecology clinic at a tertiary hospital in Southwestern Uganda. METHODS: We conducted a hospital based cross-sectional study among 361 women aged 15-49 years, presenting with abnormal vaginal discharge at the gynecology clinic of Mbarara Regional Referral Hospital from December 2020 to June 2021. Demographic characteristics were collected using a structured questionnaire. We collected cervical and vaginal sterile swabs and subjected them to wet preparation and gram stain. The specimens were cultured for bacterial isolates. Susceptibility testing was performed on samples with bacterial isolates using the Kirby-Bauer disc diffusion method, on the commonly prescribed antibiotics in this setting. We summarized and described the bacterial isolates and antibiotic susceptibility patterns as frequencies and percentages. RESULTS: We enrolled 361 women with abnormal vaginal discharge. Bacteria were isolated in 29.6% (107/361) of the women, and the commonest isolates included; Staphylococcus aureus 48.6% (52/107), Klebsiella pneumoniae 29.9% (32/107) and Enterococcus faecalis 15% (16/107). Yeast cells were found in 17.7% (64/361) of the women with abnormal vaginal discharge. Cefuroxime (90.7%) and Ciprofloxacin (81.3%) had a high level of sensitivity while high levels of resistance were observed for Doxycycline (86.0%) and Azithromycin (67.0%). CONCLUSION: The common bacterial isolates were Staphylococcus aureus, Klebsiella pneumoniae and Enterococcus faecalis. The isolated bacteria were most sensitive to Cefuroxime and Ciprofloxacin but resistant to Doxycycline and Azithromycin. There is need for routine culture and susceptibility testing of women with abnormal vaginal discharge so as to guide treatment, minimize inappropriate antibiotic use and consequently reduce antibiotic resistance.

Concanamycin A counteracts HIV-1 Nef to enhance immune clearance of infected primary cells by cytotoxic T lymphocytes.

Nef is an HIV-encoded accessory protein that enhances pathogenicity by down-regulating major histocompatibility class I (MHC-I) expression to evade killing by cytotoxic T lymphocytes (CTLs). A potent Nef inhibitor that restores MHC-I is needed to promote immune-mediated clearance of HIV-infected cells. We discovered that the plecomacrolide family of natural products restored MHC-I to the surface of Nef-expressing primary cells with variable potency. Concanamycin A (CMA) counteracted Nef at subnanomolar concentrations that did not interfere with lysosomal acidification or degradation and were nontoxic in primary cell cultures. CMA specifically reversed Nef-mediated down-regulation of MHC-I, but not CD4, and cells treated with CMA showed reduced formation of the Nef:MHC-I:AP-1 complex required for MHC-I down-regulation. CMA restored expression of diverse allotypes of MHC-I in Nef-expressing cells and inhibited Nef alleles from divergent clades of HIV and simian immunodeficiency virus, including from primary patient isolates. Lastly, we found that restoration of MHC-I in HIV-infected cells was accompanied by enhanced CTL-mediated clearance of infected cells comparable to genetic deletion of Nef. Thus, we propose CMA as a lead compound for therapeutic inhibition of Nef to enhance immune-mediated clearance of HIV-infected cells.

Safety Goggles with Elastic Headband to Improve N95 Fit Following Failed Quantitative Fit Test.

Introduction: N95 respirators, together with eye protection, form vital elements of personal protective equipment (PPE) for healthcare workers (HCW) caring for patients with respiratory infections, such as COVID-19. Duckbill N95 respirators are widely used but have a high failure rate when Fit Tested. The commonest site for inward leaks is the region between the nose and maxilla. Safety goggles with an elastic headband may press the upper rim of the respirator against the face, thereby reducing inward leaks. We hypothesized that the use of safety goggles with an elastic headband will improve the overall fit-factor of a duckbill N95 respirator and increase the proportion of users who pass a quantitative Fit Test. Methods: About 60 volunteer HCWs, who had previously failed quantitative Fit Testing with a duckbill N95 respirator, participated in this before-and-after intervention study. A PortaCount® 8048 was used for quantitative Fit Testing. The test was first performed with a duckbill N95 respirator only. It was then repeated after participants donned a pair of safety goggles (3M Fahrenheit, ID 70071531621). Results: Before the intervention, i.e., with the respirator only, 8 (13.3%) participants passed their Fit Test. This increased to 49 (81.7%) after the application of safety goggles (OR 42, 95% CI 7.14-1697.9, p < 0.0001). The adjusted mean overall fit factor, using Tobit regression analysis, increased from 40.3 to 193.0 (t = 12.32, p < 0.001). Conclusion: The use of safety goggles with an elastic headband significantly increases the proportion of users who pass a quantitative Fit Test and improves the fit-factor of a duckbill N95 respirator. How to cite this article: Kamal M, Bhatti M, Stewart WC, Johns M, Collins D, Shehabi Y, et al. Safety Goggles with Elastic Headband to Improve N95 Fit Following Failed Quantitative Fit Test. Indian J Crit Care Med 2023;27(6):386-391.

Implementing and evaluating far-field 3D X-ray diffraction at the I12 JEEP beamline, Diamond Light Source.

Three-dimensional X-ray diffraction (3DXRD) is shown to be feasible at the I12 Joint Engineering, Environmental and Processing (JEEP) beamline of Diamond Light Source. As a demonstration, a microstructually simple low-carbon ferritic steel was studied in a highly textured and annealed state. A processing pipeline suited to this beamline was created, using software already established in the 3DXRD user community, enabling grain centre-of-mass positions, orientations and strain tensor elements to be determined. Orientations, with texture measurements independently validated from electron backscatter diffraction (EBSD) data, possessed a ∼0.1° uncertainty, comparable with other 3DXRD instruments. The spatial resolution was limited by the far-field detector pixel size; the average of the grain centre of mass position errors was determined as ±âˆ¼80 µm. An average per-grain error of ∼1 × 10-3 for the elastic strains was also measured; this could be reduced in future experiments by improving sample preparation, geometry calibration, data collection and analysis techniques. Application of 3DXRD onto I12 shows great potential, where its implementation is highly desirable due to the flexible, open architecture of the beamline. User-owned or designed sample environments can be used, thus 3DXRD could be applied to previously unexplored scientific areas.

Assessment of Cavitation Intensity in Accelerating Syringes of Spring-Driven Autoinjectors.

PURPOSE: Cavitation is an undesired phenomenon that may occur in certain types of autoinjectors (AIs). Cavitation happens because of rapid changes of pressure in a liquid, leading to the formation of small vapor-filled cavities, which upon collapsing, can generate an intense shock wave that may damage the device container and the protein drug molecules. Cavitation occurs in the AI because of the syringe-drug relative displacement as a result of the syringe's sudden acceleration during needle insertion and the ensuing pressure drop at the bottom of the container. Therefore, it's crucial to analyze the potential effect of cavitation on AI. The goal of the current study is to investigate the effects of syringe and AI design parameters such as air gap size, syringe filling volume, fluid viscosity, and drive spring force (syringe acceleration) on the risk and severity of cavitation. METHODS: A model autoinjector platform is built to record the syringe and cavitation dynamics which we use to estimate the cavitation intensity in terms of extension rate and to study the effects of design parameters on the severity of cavitation. RESULTS: Our results show the generation of an intense shock wave and a high extension rate upon cavitation collapse. The induced extension rate increases with syringe acceleration and filling volume and decreases with viscosity and air gap size. CONCLUSION: The most severe cavitation occurred in an AI device with the larger drive spring force and the syringe of a smaller air gap size filled with a less viscous fluid and a larger filling volume.

Use of Chipless RFID as a Passive, Printable Sensor Technology for Aerospace Strain and Temperature Monitoring.

This paper was concerned with the current level of progress towards the development of chipless radio frequency identification (RFID) sensors that are capable of sensing strain and temperature. More specifically, it was interested in the possibility that the resulting devices could be used as a passive wireless structural health monitoring (SHM) sensor technology that could be printed in situ. This work contains the development and performance characterization results for both novel strain and novel temperature sensor designs with resulting sensitivities of 9.77 MHz/%ε and 0.88 MHz/°C, respectively. Furthermore, a detailed discussion on the interrogation system required to meet the relevant aerospace sensing requirements was also discussed, and several methods were explored to enhance the multi-sensor support capabilities of this technology.

Deterministic Sorting of Submicrometer Particles and Extracellular Vesicles Using a Combined Electric and Acoustic Field.

Sorting of extracellular vesicles has important applications in early stage diagnostics. Current exosome isolation techniques, however, suffer from being costly, having long processing times, and producing low purities. Recent work has shown that active sorting via acoustic and electric fields are useful techniques for microscale separation activities, where combining these has the potential to take advantage of multiple force mechanisms simultaneously. In this work, we demonstrate an approach using both electrical and acoustic forces to manipulate bioparticles and submicrometer particles for deterministic sorting, where we find that the concurrent application of dielectrophoretic (DEP) and acoustophoretic forces decreases the critical diameter at which particles can be separated. We subsequently utilize this approach to sort subpopulations of extracellular vesicles, specifically exosomes (<200 nm) and microvesicles (>300 nm). Using our combined acoustic/electric approach, we demonstrate exosome purification with more than 95% purity and 81% recovery, well above comparable approaches.

Gene expression during larval caste determination and differentiation in intermediately eusocial bumblebees, and a comparative analysis with advanced eusocial honeybees.

The queen-worker caste system of eusocial insects represents a prime example of developmental polyphenism (environmentally-induced phenotypic polymorphism) and is intrinsic to the evolution of advanced eusociality. However, the comparative molecular basis of larval caste determination and subsequent differentiation in the eusocial Hymenoptera remains poorly known. To address this issue within bees, we profiled caste-associated gene expression in female larvae of the intermediately eusocial bumblebee Bombus terrestris. In B. terrestris, female larvae experience a queen-dependent period during which their caste fate as adults is determined followed by a nutrition-sensitive period also potentially affecting caste fate but for which the evidence is weaker. We used mRNA-seq and qRT-PCR validation to isolate genes differentially expressed between each caste pathway in larvae at developmental stages before and after each of these periods. We show that differences in gene expression between caste pathways are small in totipotent larvae, then peak after the queen-dependent period. Relatively few novel (i.e., taxonomically-restricted) genes were differentially expressed between castes, though novel genes were significantly enriched in late-instar larvae in the worker pathway. We compared sets of caste-associated genes in B. terrestris with those reported from the advanced eusocial honeybee, Apis mellifera, and found significant but relatively low levels of overlap of gene lists between the two species. These results suggest both the existence of low numbers of shared toolkit genes and substantial divergence in caste-associated genes between Bombus and the advanced eusocial Apis since their last common eusocial ancestor.

Enhancing Adaptations to Neuromuscular Electrical Stimulation Training Interventions.

Neuromuscular electrical stimulation (NMES) applied to skeletal muscles is an effective rehabilitation and exercise training modality. However, the relatively low muscle force and rapid muscle fatigue induced by NMES limit the stimulus provided to the neuromuscular system and subsequent adaptations. We hypothesize that adaptations to NMES will be enhanced by the use of specific stimulation protocols and adjuvant interventions.

The Interface Motion and Hydrodynamic Shear of the Liquid Slosh in Syringes.

PURPOSE: Interface motion and hydrodynamic shear of the liquid slosh during the insertion of syringes upon autoinjector activation may damage the protein drug molecules. Experimentally validated computational fluid dynamics simulations are used in this study to investigate the interfacial motion and hydrodynamic shear due to acceleration and deceleration of syringes. The goal is to explore the role of fluid viscosity, air gap size, syringe acceleration, syringe tilt angle, liquid-wall contact angle, surface tension and fill volume on the interface dynamics caused by autoinjector activation. METHODS: A simplified autoinjector platform submerged in water is built to record the syringe and liquid motion without obstruction of view. The syringe kinematics is imported to the simulations based on OpenFOAM InterIsoFoam solver, which is used to study the effects of various physical parameters. RESULTS: The simulations agree with experiments on the air-liquid interface profile and interface area. The interfacial area and the volume of fluid subject to high strain rate decrease with the solution viscosity, increase with the air gap height, syringe velocity, tilt angle and syringe wall hydrophobicity, and hardly change with the surface tension and liquid column height. The hydrodynamic shear mainly occurs near the syringe wall and entrained bubbles. CONCLUSION: For a given dose of drug solution, the syringe with smaller radius and larger length will generate less liquid slosh. Reducing the air volume and syringe wall hydrophobicity are also helpful to reduce interface area and effective shear. The interface motion is reduced when the syringe axis is aligned with the gravitational direction.

Subcutaneous Injection Site Pain of Formulation Matrices.

PURPOSE: The objective of this work was to systematically evaluate the effects of formulation composition on subcutaneous injection site pain (ISP) using matrices comprising of common pharmaceutical excipients. METHODS: Two randomized, blinded, crossover studies in healthy subjects were conducted at a single site, where subjects received 1 mL SC injections of the buffer matrices. ISP intensity was measured using a 100 mm visual analogue scale (VAS), which was then analyzed via heatmap, categorical grouping, subgroup analysis, and paired delta analysis. RESULTS: Buffer type, buffer concentration and tonicity agent showed a substantial impact on ISP. Citrate buffer demonstrated a higher ISP than acetate buffer or saline). The 20 mM citrate buffer was more painful than 10 or 5 mM citrate buffers. NaCl and propylene glycol were significantly more painful than sugar alcohols (mannitol, sucrose, trehalose or glycerol). Histidine buffers exhibited ISP in the descending order of 150 mM > 75 mM > 25 mM > 0 mM NaCl, while histidine buffers containing Arginine-HCl at 0, 50, or 150 mM all showed very low ISP. Histidine buffer at pH 6.5 showed a lower ISP than pH 5.7. CONCLUSIONS: This systematic study via orthogonal analyses demonstrated that subcutaneous ISP is significantly influenced by solution composition.