Normal pH Research Articles

Integrative proteomics and metabolomics profiling to understand the biochemical basis of beef muscle darkening at a slightly elevated pH.

Previous studies investigated the biochemical basis of dark-cutting conditions at elevated muscle pH (above 6), but the molecular basis at slightly above normal pH (between 5.6 and 5.8) is still unclear. The objective was to determine protein and metabolite profiles to elucidate postmortem muscle darkening at slightly elevated pH. Loins were selected based on the criteria established in our laboratory before sample collections, such as pH less than 5.8, L* values (muscle lightness) less than 38, and not discounted by the grader (high-pH beef with dark color are discounted and not sold in retail stores). Six bright red loins (longissimus lumborum) at normal-pH (average pH = 5.57) and six dark-colored strip loins at slightly elevated pH (average pH = 5.70) from A maturity carcasses were obtained within 72-h postmortem from a commercial beef purveyor. Surface color, oxygen consumption, metmyoglobin reducing activity, protein, and metabolite profiles were determined on normal-pH and dark-colored steaks at slightly elevated pH. Enzymes related to glycogen metabolism and glycolytic pathways were more differently abundant than metabolites associated with these pathways. The results indicated that oxygen consumption and metmyoglobin reducing activity were greater (P < 0.05) in darker steaks than normal-pH steaks. Enzymes involved with glycogen catabolic pathways and glycogen storage disease showed lower abundance in dark beef. The tricarboxylic acid metabolite, aconitic acid, was overabundant in darker-colored beef than normal-pH beef, but glucose derivative metabolites were less abundant. The majority of glycogenolytic proteins and metabolites reported as overabundant in the previous dark-cutting studies at high pH (>6.4) also did not show significant differences in the current study. Therefore, our data suggest enzymes involved in glycogen metabolism, in part, create a threshold for muscle darkening than metabolites.

Nanoformulation of Paclitaxel: Exploring the Cyclodextrin / PLGA Nano Delivery Carrier to Slow Down Paclitaxel Release, Enhance Accumulation in Vivo.

Background: Improving the aggregation and penetration in tumor sites increases the anti-tumor efficacy of nanomedicine. In the current study, we designed cyclodextrin modified PLGA nanoparticles loaded with paclitaxel to elevate the accumulation and prolong circulation of chemotherapy drugs in vivo. Methods: The PLGA nanoparticles loaded with paclitaxel (PTX PLGA NPs) and cyclodextrin (CD) modified PLGA nanoparticles loaded with paclitaxel (PTX PLGA/CD NPs) were prepared using the emulsification solvent evaporation method. The nanoparticles were characterized by particle size, zeta potential, encapsulation efficiency, infrared spectroscopy analysis and X-Ray diffraction (XRD). Then, drug release of the nanoparticles was evaluated via reverse dialysis method in vitro. Finally, the in vivo distribution fate and pharmacokinetic characteristics of the nanoparticles were assessed in mice and rats. Results: The average particle size, zeta potential, and encapsulation efficiency of PTX PLGA NPs were (163.57±2.07) nm, - (20.53±2.79) mV and (60.44±6.80)%. The average particle size, zeta potential, and encapsulation efficiency of PTX PLGA/CD NPs were (148.57±1.66) nm, - (11.42±0.84) mV and (85.70±2.06)%. In vitro release studies showed that PTX PLGA/CD NPs were released more slowly compared to PTX PLGA NPs under normal blood pH conditions, while PTX PLGA/CD NPs were released more completely under tumor site pH conditions. The modified PLGA nanocarrier (PLGA/CD NPs) increased drug residence time and accumulation than the plain PLGA nanocarrier (PLGA NPs) in vivo distribution. In addition, the elimination half-life, area under the drug-time curve, and maximum blood concentration of the nanoparticle group were higher than those of Taxol®, especially the PTX PLGA/CD NPs group, which was significantly different from Taxol® and plain nanoparticle groups (p<0.001). Conclusions: The 2-HP-β-CD modified PLGA nanoparticles prolonged circulation time and accumulation of the chemotherapy drug paclitaxel in vivo.

Assessment of the Quality of Bar Soaps Produced from Blends of Palm-Oil and African Walnut Seed-Oil

This study was conducted to determine the characteristics of soap produced from various fats and oils. Palm oil was purchased, and walnut oil was extracted from its seeds. Five blends of palm oil and African walnut oil were used, together with their individual oils. The cold method of soap-making was employed in this study. Five blends (PW0, PW1, PW2, PW3, and WP0) were prepared in a ratio, and each blend was used for soap production. Each oil blend was characterized for saponification value, acid value, peroxide value, iodine value, and free fatty acid content, and their results were as follows: (182±0.20 – 234±0.30 mgKOH/g), (1.60±0.20 – 3.37±0.12 mgKOH/g), (5.0±0.25 –12.5±0.1 Meq KOH/g), (37.5±0.50 – 55.6±0.25 gI2100/g) and (0.80±0.20 – 1.68±0.12 mgKOH/g). The percentage of total fatty matter in the soap samples ranged from (52±0.1% to 77 ± 0.05%). WP0 (palm oil 0% – walnut oil 100%) had the lowest percentage value of total fatty matter (52±0.1%) among the soap samples produced, while PW0 (palm oil 100% – walnut oil 0%) had the highest percentage value of total fatty matter (77±0.05%). Judging by % total fatty matter, PW0 gave the best soaps because its total fatty matter value fell within the acceptable limits of the Standard Organization of Nigeria (SON). The pH values observed from the blended samples ranged from 10.28 ± 0.01 – 12.20 ± 0.03. PW3 (palm oil 25% – walnut 75%) had the highest values of 12.20 ± 0.03, which makes it harsh for the body. Thus, based on the findings of this study, it can be concluded that soap samples PW0 (palm oil 100% – walnut 0%) and PW1 (palm oil 75% – walnut 25%) can be suggested for use in laundry due to their favorable physicochemical properties (high% Total Fatty Matter, normal pH values, high foam ability).

GREEN SYNTHESIS OF NANOPARTICLES FROM SEAWEEDS – A LITERATURE REVIEW

Marine seaweeds that belong to Chlorophyta, Rhodophyta, and Phaeophyta groups are reported to biosynthesize metal nanoparticles. The morphology and the stability of the nanoparticles obtained from seaweeds for biomedical and environmental applications are equivalent in most aspects to other “green” methodologies. The ability of algae to accumulate metals and reduce metal ions make them a superior contender for the biosynthesis of nanoparticles and hence they are called bio-nano factories as both the live and dead dried biomass are used for the synthesis of metallic nanoparticles. The biosynthesis of nanoparticles using seaweeds can be scaled up to meet industrial requirements. Algae are relatively convenient to handle, less toxic, and less harmful to the environment; synthesis can be carried out at ambient temperature and pressure and in simple aqueous media at a normal pH value. Therefore, this review elaborates seaweeds as a better tool for the fabrication of metal nanoparticles.

Sporadic accelerations during labor strongly indicate normal pH, whereas periodic accelerations do not: a case–control study

Purpose To determine the association between the occurrence of sporadic and periodic fetal heart rate accelerations during labor and acidemia at birth. Materials and methods This is a case–control study of fetal heart rate patterns from 364 neonates with acidemia at birth (cord blood pH <7.05 at vaginal birth, or pH <7.10 at birth after first stage cesarean delivery) and 731 controls with pH ≥7.15. The last 30–60 min of the cardiotocographic traces before birth from the neonates born with acidemia and from the corresponding stage in labor for the controls were scrutinized. Odds ratios (OR) with 95% confidence interval for acidemia at birth were determined. Results During the first stage, ≥2 sporadic accelerations were present in 16% of cases and 78% of controls; OR for acidemia (compared to 0–1 accelerations) 0.05 (0.02–0.10). In the second stage, the corresponding rates were 13% and 60%, OR 0.09 (0.06–0.14). Isolated periodic accelerations were infrequent. A weak negative association between ≥2 periodic accelerations and acidemia (compared with 0–1 accelerations) was found in the second stage, OR 0.51 (0.30–0.86), but was not significant in the first stage, OR 0.24 (0.04–1.4). Even among fetuses with normal fetal heart rate variability (5–25 beats per minute) the occurrence of less than two sporadic accelerations was associated with an increased risk of acidemia, OR 10.3 (7.2–14.8). Conclusions Sporadic accelerations indicate a very low probability of acidosis but are absent in 40% of fetuses with normal pH during a 30–60 min second-stage recording.

Tumor acidic environment directs nanoparticle impacts on cancer cells

Despite impressive progress in nanotechnology-based cancer therapy being made by in vitro research, few nanoparticles (NPs) have been translated into clinical trials. The wide gap between in vitro results and nanomedicine’s clinical translation might be partly due to acidic microenvironment of cancer cells being ignored in in vitro studies. To check this hypothesis, we studied the biological impacts of two different structures of NPs on cancer cells (MDA-MB 231) at acidic (pH: 6.5) low (pH: 7) and physiological pH (pH: 7.4). We uncovered that a slight change in the pH of the cancer cell microenvironment affects the cellular uptake efficacy and toxicity mechanism of nanographene sheets and SPION@silica nanospheres. Both nanostructures exerted more substantial toxic impacts (e. g. apoptosis, necrosis, membrane disruption, and oxidative stress induction) against cancer cells at physiological pH compared to acidic niche. They also differently slowed or arrested phases of the cell cycle at different pH (S and G2/M at normal pH while G0/G1 at acidic/low pH). More specifically, cancer cells expressed higher levels of interleukins involved in cancer cell resistance at acidic pH than those incubated at physiological pH. This study revealed that a slight change in extracellular pH of cancer cells could strongly affect the therapeutic/toxic impact of nanomaterials and therefore, it should be considered in the future cancer nanomedicine research.

Perancangan Sistem Monitoring Kualitas Tanah Sawah Dengan Parameter Suhu Dan Kelembaban Tanah Menggunakan Arduino Berbasis Internet Of Things (Iot)

Water is very important for all aspects of life on earth, agriculture is one of the fields that really need large amounts of water because of the use of water in the&#x0D; process of plant photosynthesis. Water that has good quality is if the water is not excessively polluted by harmful chemicals or minerals. One indicator that water is polluted is a change in temperature and pH (acidity) of the water. Temperatures that are too hot in the water will interfere with the growth of plants and other microorganisms. While the normal pH of water has a pH that ranges from 6.5 to 7.5. The quality of water and soil is very important in agriculture. The level of acidity (pH) and soil temperature are one of the things that affect plant fertility. Therefore, the quality of water and soil on agricultural land is one of the important things that needs special attention in its management. One solution so that water and soil quality can be monitored and managed efficiently is to utilize a Wireless Sensor Network based on the Internet of Things (IoT). The use of the ESP8266 Module as a WIFI module, is widely used by Internet of Things-based applications because the price is cheap so it reduces a lot of costs and has a fairly good speed of 80 MHz. This study aims to develop the concept of a Wireless Sensor Network by utilizing the ESP8266 module to monitor pH values using a pH Meter Analog Kit sensor and temperature from agricultural land using a DS18B20 Waterproof sensor and can be monitored at any time using a smartphone.

Application of integrated sequence of air stripping, coagulation flocculation, electrocoagulation and adsorption for sustainable treatment of municipal landfill leachate

Leachate generated from landfill is required to be treated by simple, fast, economic and environmentally sustainable methods before being discharged to the environment since it is considered as a highly pollutant wastewater. The aim of this research work is to check the potential treatability of integrated sequence of air stripping, coagulation flocculation, electrocoagulation and adsorption method for leachate generated from an uncontrolled municipal solid waste landfill site complying with legal discharge standard. At optimum retention period of 36 hours air stripping method exhibited a maximum removal of 96.87% of NH 4 -N, 74.5% of BOD 5 , 52.78% of COD, 8.7% of Hg and 18.43% of Pb from raw leachate at normal pH and air flow rate of 10 L/min. The application of optimized CF process using FeCl 3 as coagulant of dosage 3.09 mg/L resulted a maximum removal of 84.20% of BOD 5 , 57.67% of COD and 46.2% of Hg at pH 5.22. Following CF process EC process was adopted with Fe electrode and optimized by CCD of response surface methodology. At optimum pH 7.46, current density 3.13 mA/cm 2 and electrolysis time 24.83 min the maximum removal was recorded as 51.1% COD and 91.92% Hg. EDAX analysis confirmed the presence of Hg in the precipitates of ECP. Finally fixed bed column adsorption study using chitosan beads resulted in 98.11% of Hg removal. The integrated treatment sequence resulting an overall removal of 96.87% of NH 4 -N, 95.97% of BOD 5 , 90.23% of COD, and 99.93% of Hg which is sufficient enough to reduce pollutants of raw leachate below discharge standards at overall costs of USD 0.036/L. • Integrated sequence of multiple physicochemical treatment methods were used to reduce pollution load from raw municipal landfill leachate. • Process variables of electrocoagulation method were optimized by center composite design of response surface methodology. • EDAX confirmed the removal of Hg by electrocoagulation process using iron electrodes. • Low cost chitosan beads were used for adsorption. • The leachate discharge standard in inland surface water was achieved at nominal cost.

Gallic Acid-Loaded Sodium Alginate-Based (Polyvinyl Alcohol-Co-Acrylic Acid) Hydrogel Membranes for Cutaneous Wound Healing: Synthesis and Characterization

Traditional wound dressings often cannot treat wounds caused by bacterial infections or other wound types that are insensitive to these wound treatments. Therefore, a biodegradable, bioactive hydrogel wound dressing could be an effective alternative option. The purpose of this study was to develop a hydrogel membrane comprised of sodium alginate, polyvinyl alcohol, acrylic acid, and gallic acid for treating skin wounds. The newly developed membranes were analyzed using Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC) and scanning electron microscopy (SEM), X-ray diffraction analysis (XRD), sol-gel fraction, porosity, mechanical strength, swelling, drug release and data modelling, polymeric network parameters, biodegradation, and antioxidation (DPPH and ABTS) and antimicrobial activity against Gram-positive and negative bacteria. The results revealed that hydrogel membranes were crosslinked successfully and had excellent thermal stability, high drug loading, greater mechanical strength, and exhibited excellent biodegradation. Additionally, the swelling ability and the porosity of the surface facilitated a controlled release of the encapsulated drug (gallic acid), with 70.34% release observed at pH 1.2, 70.10% at pH 5.5 (normal skin pH), and 86.24% at pH 7.4 (wounds pH) in 48 h. The gallic acid-loaded hydrogel membranes showed a greater area of inhibition against Pseudomonas aeruginosa, Staphylococcus aureus, and Escherichia coli bacteria as well as demonstrated excellent antioxidant properties. Based on Franz cell analyses, the permeation flux of the drug from optimized formulations through mice skin was 92 (pH 5.5) and 110 (pH 7.4) μg/cm2·h-1. Moreover, hydrogel membranes retained significant amounts of drug in the skin for 24 h, such as 2371 (pH 5.5) and 3300 µg/cm2 (pH 7.4). Acute dermal irritation tests in rats showed that hydrogel membranes were nonirritating. Hydrogel membranes containing gallic acid could be an effective option for improving wound healing and could result in faster wound healing.

Crosstalk between tumor acidosis, p53 and extracellular matrix regulates pancreatic cancer aggressiveness.

Pancreatic ductal adenocarcinoma (PDAC) is an extremely aggressive malignancy with minimal treatment options and a global rise in prevalence. PDAC is characterized by frequent driver mutations including KRAS and TP53 (p53), and a dense, acidic tumor microenvironment (TME). The relation between genotype and TME in PDAC development is unknown. Strikingly, when wild type (WT) Panc02 PDAC cells were adapted to growth in an acidic TME and returned to normal pH to mimic invasive cells escaping acidic regions, they displayed a strong increase of aggressive traits such as increased growth in 3-dimensional (3D) culture, adhesion-independent colony formation and invasive outgrowth. This pattern of acidosis-induced aggressiveness was observed in 3D spheroid culture as well as upon organotypic growth in matrigel, collagen-I and combination thereof, mimicking early and later stages of PDAC development. Acid-adaptation-induced gain of cancerous traits was further increased by p53 knockout (KO), but only in specific extracellular matrix (ECM) compositions. Akt- and Transforming growth factor-β (TGFβ) signaling, as well as expression of the Na+ /H+ exchanger NHE1, were increased by acid adaptation. Whereas Akt inhibition decreased spheroid growth regardless of treatment and genotype, stimulation with TGFβI increased growth of WT control spheroids, and inhibition of TGFβ signaling tended to limit growth under acidic conditions only. Our results indicate that a complex crosstalk between tumor acidosis, ECM composition and genotype contributes to PDAC development. The findings may guide future strategies for acidosis-targeted therapies.

RAB7A GTPase Is Involved in Mitophagosome Formation and Autophagosome-Lysosome Fusion in N2a Cells Treated with the Prion Protein Fragment 106-126.

Failed communication between mitochondria and lysosomes causes dysfunctional mitochondria, which may induce mitochondria-related neurodegenerative diseases. Here, we show that RAB7A, a small GTPase of the Rab family, mediates the crosstalk between these two important organelles to maintain homeostasis in N2a cells treated with PrP106-126. Specifically, we demonstrate that mitophagy deficiency in N2a cells caused by PrP106-126 is associated with dysregulated RAB7A localization in mitochondria. Cells lacking RAB7A display decreased mitochondrial colocalization with lysosomes and significantly increased mitochondrial protein expression, resulting in inhibited mitophagy. In contrast, overexpression of GTP-bound RAB7A directly induces lysosome colocalization with mitochondria. Further study revealed that GTP-bound RAB7A protects mitochondrial homeostasis by supporting autophagosome biogenesis. Moreover, wesuggest that depletion of RAB7A leads to gross morphological changes in lysosomes, which prevents autophagosome-lysosome fusion and interferes with the breakdown of autophagic cargo within lysosomes. Overexpression of GTP-bound RAB7A can also alleviate PrP106-126-induced morphological damage and dysfunction of mitochondria, reducing neuronal apoptosis. Collectively, our data demonstrate that RAB7A successfully drives mitochondria to the autophagosomal lumen for degradation, suggesting that the communication of proteotoxic stress from mitochondria to lysosomes requires RAB7A, as a signaling molecule, to establish a link between the disturbed mitochondrial network and its remodeling. These findings indicate that small molecules regulating mitophagy have the potential to modulate cellular homeostasis and the clinical course of neurodegenerative diseases. Proposed model of mitophagy regulated by RAB7A. (1) Accumulating PrP106-126 induced mitophagy. (2) RAB7A is recruited to mitochondria. (3) ATG5-12 and ATG9A (5) vesicles are recruited to the autophagosome formation sites in a RAB7A-dependent manner. The ATG5-12 complex recruits and anchors LC3-I to form active LC3-II (4), accelerating mitophagosomal formation. The ATG9A vesicles are thought to be a source of membranes for autophagosome assembly. The recruitment of proteins and lipids induces membrane expansion and subsequent closure to form the mitophagosome. (6) Maintenance of the normal low lysosomal PH depends on active (GTP-bound) RAB7A. (7) RAB7A recruits effector molecules responsible for tight membrane interactions, and directly or indirectly, the subsequent autophagosome merges with the lysosome, and the cargo is completely degraded.

The Effect of Painless Delivery with Intrathecal Sufentanil on Labor Progress and Neonatal Outcomes: A Single Center Study on Pregnant Women.

Delivery pain is the most unbearable pain and can be relieved with intrathecal opioids. This study aimed to investigate the effect of intrathecal sufentanil for painless delivery on labor progress and neonatal outcomes in pregnant women. This was a single-arm observational cohort study on 1055 pregnant women candidates for vaginal delivery with spinal analgesia referred to the Akbarabadi Hospital. First, 0.1 µg/kg of intrathecal sufentanil was used, and maternal blood pressure and maternal and fetal heart rates were recorded after analgesia. During delivery, the mothers were monitored for nausea, pruritus, motor block, apnea, urinary retention, or the possibility of an emergency cesarean section. The duration of the analgesia, the duration of the second stages of labor, and the mother's pain scores were recorded based on the Visual Analogue Scale (VAS). 1- and 5-minute Apgar scores and arterial blood gas (ABG) of the umbilical cord were also recorded. The most common station was -3 for 723 women, followed by -2 for 229 women. Fifty-two women underwent cesarean section, and fetal distress was the most common reason for cesarean section (57.7%). The mean time for initiating analgesia was 5.93 ± 2.87 minutes, and the mean visual analog scale was 1.08 ± 0.16. The mean Apgar was 9.0 ± 0.47; the mean weight at birth was 2917.39 ± 449.90 gr; PH was 7.31 ± 2.03; HCO3 was 22.67 ± 3.08mEq/liter, and PaCo2 was 43.36 ± 7.06 mmHg. Regarding complications, the patients just developed itching (n = 78), and hypotension, bradycardia, apnea, and decreased consciousness were overlooked. Intrathecal sufentanil is safe and efficient in painless delivery, resulting in normal Apgar and normal PH with no specific side-effect.

Drug Physicochemical Properties and Capsule Fill Determine Extent of Premature Gastric Release from Enteric Capsules.

Intrinsically, enteric capsule shells offer several advantages compared to coating of dosage forms with enteric polymers. We undertook a systematic investigation to elucidate capsule-fill parameters that may result in premature gastric drug release from Vcaps® Enteric capsules (Lonza CHI, Morristown, NJ, USA). Four model drugs with different ionization and solubility profiles were investigated: acetaminophen, ketoprofen, trimethoprim and atenolol. Different fill loads, diluents and drug-to-diluent ratios were explored. Enteric capsules were filled with drug or drug and diluent powder mix and underwent USP II dissolution testing using mini-vessels and paddles. Capsules were tested in pH 2 (0.01 M HCl) or pH 4.5 (3.2 × 10-5 M HCl) 200 mL acid media to simulate normal, fasted or hypochlorhydric gastric pH, respectively. Acetaminophen, trimethoprim and atenolol displayed premature gastric drug release from enteric capsules. The extent of premature release was dependent on drug solubility, ionization profile and capsule-fill level. At 100 mg drug-fill level, acetaminophen, trimethoprim and atenolol gave rise to 10.6, 12.2 and 83.1% drug release, respectively, in normal, fasted, gastric fluids. Diffusion layer pH of trimethoprim and atenolol in pH 2 media was determined to be pH 6.3 and 10.3, respectively. Upon increasing capsule-fill load using microcrystalline cellulose as a diluent, a significant reduction in premature gastric release was observed. However, including mannitol as a diluent was only effective at decreasing premature drug release at a low drug-to-diluent ratio. Systematic in vitro screening of enteric capsule fills needs to be conducted to ensure that drug product performance is not compromised.

Severe Hypertriglyceridemia Causing Pseudo-acidosis: A Case Report

Pseudo hypobicarbonatemia is a rare phenomenon associated with spuriously low bicarbonate levels in the presence of elevated triglycerides (TG). TG’s interfere with commonly used enzymatic assays in basic metabolic panel (BMP), giving falsely low bicarbonate levels. It adds to the diagnostic dilemma and possible extensive workup to identify the cause. Previous case reports have used plasmapheresis in these settings. We report the successful use of insulin infusion in managing a case of pseudo-acidosis secondary to severely high TG levels. Our patient was a 53-year-old female who presented with complaints of progressive fatigue. Her bicarbonate was 5 mmol/L on workup, anion gap was 30 mmol/L, with elevated TG levels (5904 mg/dL). Arterial blood gas analysis showed normal pH (7.32) and normal calculated bicarbonate (22.8 mmol/L). Insulin infusion was started along with adding fenofibrate and atorvastatin. TG levels decreased progressively to 509 mg/dL with an associated normalization of bicarbonate levels and anion-gap acidosis on BMP. The patient was discharged on day 8 of her hospital stay. Hyper TG can lead to pseudo hypobicarbonatemia, presenting as pseudo anion gap metabolic acidosis. It is essential to correlate the lab findings in the perspective of clinical findings to avoid over-testing and clinical misdiagnosis. In addition, these patients can be managed safely with insulin infusion in resource-limited settings.

ODP184 Diabetic Postural Dizziness,Hyperlactatemia,Hyponatremia-Role of Fludrocortisone

Abstract Background Fludrocortisonehas been used in the management of idiopathic postural hypotension and occasionally in diabetic postural hypotension. [1]Enhanced sympathetic nervous system(SNS) activity consequent upon autonomic dysfunction has been linked with the development and maintenance of hyperlactatemia and lactic acidosis(converted to lactate at physiological pH). [2]The mineralocorticoid property of fludrocortisone is utilized inthe management of hyponatremia and hypovolemia. [3] Clinical Cases: Hereby,two T2DM patients are being discussed where fludrocortisone(0.1 mg/d) provided symptomatic relief in postural dizziness. The first patient was a 60 year-old obese, euthyroid,hypertensive male having diabetes(insulin requiring)for the last 30 years with normal kidney function and complaints of frequent postural dizziness and occasional fainting attacks,although,there was no postural drop of blood pressure or tachycardia. He had lactate levels of 4 to 5 mmol/L with normal pH and bicarbonate. He had symptomatic relief with fludrocortisone(being taken for the last four years) with no rise of blood pressure or change in electrolytes or lactate levels. He had associated epigastric fullness and erectile dysfunction(suggestive of autonomic neuropathy). The other patient was an 80 year-old male, euthyroid,normotensive,insulin requiring diabetic for last 27 years with normal kidney function. He was operated for right adrenocortical carcinoma almost 30 years ago which was uneventful till three years ago when he presented with breathlessness and was diagnosed as having adrenal metastasis(immunohistochemistry)in lungs. Thereafter,he developed postural dizziness(despite being on ivabradine),cognitive decline along with abdominal fullness and urinary incontinence(suggestive of autonomic neuropathy). He had hyponatremia(possibly due to SIADH) which rose from 117 mmol/L on 15 mg/d tolvaptan to 123 mmol/L on 30 mg/d. There was significant relief in postural dizziness and slight improvement in serum sodium(rose to 124mmol/L)with 0.10 mg/d fludrocortisone. A lower dose of fludrocorisone is required for symptomatic relief in diabetic postural hypotension (efferent fibre lesion affecting SNS, possibly with reduced renin secretion in response to erect posture) as compared to idiopathic postural hypotension(afferent or central lesion). Fludrocortisone has been reported to increase serum sodium in short-term studies whereas serum sodium remained in normal range and there was no increase in blood pressure in long-term studies. [1] Conclusion: These cases highlight the benefit of fludrocortisone in the management of diabetic postural dizziness and hyponatremia and the rare association of hyperlactatemia with autonomic dysfunction.

Identification of the Acid-Sensitive Site Critical for Chloral Hydrate (CH) Activation of the Proton-Activated Chloride Channel.

The transmembrane protein TMEM206 was recently identified as the molecular basis of the extracellular proton-activated Cl- channel (PAC), which plays an essential role in neuronal death in ischemia-reperfusion. The PAC channel is activated by extracellular acid, but the proton-sensitive mechanism remains unclear, although different acid-sensitive pockets have been suggested based on the cryo-EM structure of the human PAC (hPAC) channel. In the present study, we firstly identified two acidic amino acid residues that removed the pH-dependent activation of the hPAC channel by neutralization all the conservative negative charged residues located in the extracellular domain of the hPAC channel and some positively charged residues at the hotspot combined with two-electrode voltage-clamp (TEVC) recording in the Xenopus oocytes system. Double-mutant cycle analysis and double cysteine mutant of these two residues proved that these two residues cooperatively form a proton-sensitive site. In addition, we found that chloral hydrate activates the hPAC channel depending on the normal pH sensitivity of the hPAC channel. Furthermore, the PAC channel knock-out (KO) male mice (C57BL/6J) resist chloral hydrate-induced sedation and hypnosis. Our study provides a molecular basis for understanding the proton-dependent activation mechanism of the hPAC channel and a novel drug target of chloral hydrate.SIGNIFICANCE STATEMENT Proton-activated Cl- channel (PAC) channels are widely distributed in the nervous system and play a vital pathophysiological role in ischemia and endosomal acidification. The main discovery of this paper is that we identified the proton activation mechanism of the human proton-activated chloride channel (hPAC). Intriguingly, we also found that anesthetic chloral hydrate can activate the hPAC channel in a pH-dependent manner. We found that the chloral hydrate activates the hPAC channel and needs the integrity of the pH-sensitive site. In addition, the PAC channel knock-out (KO) mice are resistant to chloral hydrate-induced anesthesia. The study on PAC channels' pH activation mechanism enables us to better understand PAC's biophysical mechanism and provides a novel target of chloral hydrate.

The Effect of pH to The Interaction between Folic Acid and Folate Receptor Alpha: Molecular Dynamics Study

Cancer is one of the major health problems in the world. Early detection using Magnetic Resonance Imaging (MRI) for the presence of cancer cells could improve the successful rate of treatment. For this reason, a selective contrast agent is required to improve the accuracy of cancer diagnosis. Many cancer cells overexpress the folate receptor alpha (FRA) on its surface. Therefore, the substrate of FRA, folic acid, can be used to develop a selective contrast agent such as Gd-DTPA-folate. However, it is worth noting that the slightly acidic pH in cancer cell could change the conformation of ligand binding site of FRA, thus lowering the affinity of folic acid-based contrast agent. Although the crystal structure of FRA in low pH has been solved, but the mechanism of decreasing affinity of folic acid is still not clear. Therefore, this work aims to study the structural change of FRA in low pH and to investigate the molecular interactions of folic acid and Gd-DTPA- folate to the FRA at normal and acidic pH using molecular dynamics simulations. A crystal structure of folic acid in complex with FRA was used as a template for simulations. The interaction energies were calculated using MM/GBSA method. As a result, the protonated Asp81 in the ligand binding site of FRA repulsed the pterin ring of folic acid. Interestingly, Gd-DTPA-folate was predicted to stabilize its interaction with FRA in low-pH as compared to the normal pH. It is hoped that this study could provide insight into the development of selective contrast agent for cancer.

Acid Adaptation Promotes TRPC1 Plasma Membrane Localization Leading to Pancreatic Ductal Adenocarcinoma Cell Proliferation and Migration through Ca2+ Entry and Interaction with PI3K/CaM.

Simple SummaryPancreatic ductal adenocarcinoma (PDAC) is one of the deadliest cancers globally, with a 5-year overall survival of less than 10%. The development and progression of PDAC are linked to its fluctuating acidic tumor microenvironment. Ion channels act as important sensors of this acidic tumor microenvironment. They transduce extracellular signals and regulate signaling pathways involved in all hallmarks of cancer. In this study, we evaluated the interplay between a pH-sensitive ion channel, the calcium (Ca2+) channel transient receptor potential C1 (TRPC1), and three different stages of the tumor microenvironment, normal pH, acid adaptation, and acid recovery, and its impact on PDAC cell migration, proliferation, and cell cycle progression. In acid adaptation and recovery conditions, TRPC1 localizes to the plasma membrane, where it interacts with PI3K and calmodulin, and permits Ca2+ entry, which results in downstream signaling, leading to proliferation and migration. Thus, TRPC1 exerts a more aggressive role after adaptation to the acidic tumor microenvironment.Pancreatic ductal adenocarcinoma (PDAC) remains one of the most lethal malignancies, with a low overall survival rate of less than 10% and limited therapeutic options. Fluctuations in tumor microenvironment pH are a hallmark of PDAC development and progression. Many ion channels are bona fide cellular sensors of changes in pH. Yet, the interplay between the acidic tumor microenvironment and ion channel regulation in PDAC is poorly understood. In this study, we show that acid adaption increases PANC-1 cell migration but attenuates proliferation and spheroid growth, which are restored upon recovery. Moreover, acid adaptation and recovery conditions favor the plasma membrane localization of the pH-sensitive calcium (Ca2+) channel transient receptor potential C1 (TRPC1), TRPC1-mediated Ca2+ influx, channel interaction with the PI3K p85α subunit and calmodulin (CaM), and AKT and ERK1/2 activation. Knockdown (KD) of TRPC1 suppresses cell migration, proliferation, and spheroid growth, notably in acid-recovered cells. KD of TRPC1 causes the accumulation of cells in G0/G1 and G2/M phases, along with reduced expression of CDK6, −2, and −1, and cyclin A, and increased expression of p21CIP1. TRPC1 silencing decreases the basal Ca2+ influx in acid-adapted and -recovered cells, but not in normal pH conditions, and Ca2+ chelation reduces cell migration and proliferation solely in acid adaptation and recovery conditions. In conclusion, acid adaptation and recovery reinforce the involvement of TRPC1 in migration, proliferation, and cell cycle progression by permitting Ca2+ entry and forming a complex with the PI3K p85α subunit and CaM.

Bacterial Vaginosis

Abstract&#x0D; Introduction: The vagina is normally inhabited by a number of organism, including Lactobacillus acidophilus, diphteroids, Candida and others. Normal vaginal flora contains aerobic and anaerobic bacteria, such as Lactobacillus species being the prominent microorganism with number more than 95% of the total bacteria present. Vaginal discharge can be classified into physiologic and pathologic discharge. Discussion: Bacterial vaginosis is a clinical syndrome caused by the alteration of Lactobacillus Sp that producing hydrogen peroxide with anaerobic bacteria that caused the disruption of the normal flora balance. Risk factors of bacterial vaginosis are sexual activity, vaginal douching, genetic, vaginal manipulation, smoking and using the intrauterine device. Diagnosis of bacterial vaginosis can be enforced by the gram staining and the calculation of Nugent score (positive diagnosis of bacterial vaginosis if nogent score 7-10). Amsel score can also be conducted if the Nugent score examination cannot be performed. Amsel score criteria consists of white homogen vaginal discharge, fishy odor (positive Whift test), pH &gt; 4.5, and the finding of clue cell. The discovery of 3 citeria of Amsel can confirm the diagnosis of bacterial vaginosis. Treatment of bacterial vaginosis including systemic and topical therapy. Systemic antibiotic such as metronidazole and clindamycin is effective against the anaerob bacteria. Conclusion: bacterial vaginosis in an abnormal condition in the vagina caused by the overgrowth of anaerobic bacteria replacing the Lactobacillus hominis that caused the change of normal acidic pH vagina into alkaline.&#x0D; Amsel criteria and Nugent score can be requested to confirm the diagnosis of bacterial vaginosis. Proper diagnosis and treatment with metronidazole and clindamycin can improve the disease.

Routine Reflux Testing Guides Timely Antireflux Treatment to Reduce Acute and Chronic Rejection After Lung Transplantation.

Gastroesophageal reflux has been associated with poorer lung transplantation outcomes, although no standard approach to evaluation/management has been adopted. We aimed to evaluate the effect of timely antireflux treatment as guided by routine reflux testing on postlung transplant rejection outcomes. This was a retrospective cohort study of lung transplant recipients at a tertiary center. All patients underwent pretransplant ambulatory pH monitoring. Timely antireflux treatment was defined as proton pump inhibitor initiation or antireflux surgery within 6 months of transplantation. Patients were separated into 3 groups: normal pH monitoring (-pH), increased reflux (+pH) with timely treatment, and +pH with delayed treatment. Rejection outcomes included acute rejection, bronchiolitis obliterans syndrome, and chronic lung allograft dysfunction per International Society for Heart and Lung Transplantation criteria. Time-to-event analyses using Cox proportional hazard models were applied. Patients not meeting outcomes were censored at death or last clinic visit. One hundred seventy-five patients (59% men/mean 56.3 yr/follow-up: 496 person-years) were included. On multivariable analyses, +pH/delayed treatment patients had higher risks of acute rejection (adjust hazard ratio [aHR]:3.81 [95% confidence interval [CI]: 1.90-7.64], P = 0.0002), bronchiolitis obliterans syndrome (aHR: 2.22 [95% CI: 1.07-4.58], P = 0.03), and chronic lung allograft dysfunction (aHR: 2.97 [95% CI: 1.40-6.32], P = 0.005) than +pH/timely treatment patients. Similarly, rejection risks were increased among +pH/delayed treatment patients vs -pH patients (all P < 0.05). No significant differences in rejection risks were noted between +pH/timely treatment patients and -pH patients. Failure/complications of antireflux treatment were rare and similar among groups. Timely antireflux treatment, as directed by pretransplant reflux testing, was associated with reduced allograft rejection risks and demonstrated noninferiority to patients without reflux. A standardized peri-transplant test-and-treat algorithm may guide timely reflux management to improve lung transplant outcomes.