Macrophages Maintain Epithelium Integrity by Limiting Fungal Product Absorption.

The colon is primarily responsible for absorbing fluids. It contains a large number of microorganisms including fungi, which are enriched in its distal segment. The colonic mucosa must therefore tightly regulate fluid influx to control absorption of fungal metabolites, which can be toxic to epithelial cells and lead to barrier dysfunction. How this is achieved remains unknown. Here, we describe a mechanism by which the innate immune system allows rapid quality check of absorbed fluids to avoid intoxication of colonocytes. This mechanism relies on a population of distal colon macrophages that are equipped with "balloon-like" protrusions (BLPs) inserted in the epithelium, which sample absorbed fluids. In the absence of macrophages or BLPs, epithelial cells keep absorbing fluids containing fungal products, leading to their death and subsequent loss of epithelial barrier integrity. These results reveal an unexpected and essential role of macrophages in the maintenance of colon-microbiota interactions in homeostasis. VIDEO ABSTRACT.

Fluid absorption during flexible ureteroscopy with intelligent control of renal pelvic pressure: a randomized controlled trial.

PURPOSE: To investigate fluid absorption and its influencing factors during flexible ureteroscopy with intelligent control of renal pelvic pressure (RPP). METHODS: A total of 80 patients with upper urinary tract calculi underwent flexible ureteroscopy with intelligent control of RPP by pressure-measuring ureteral access sheath and were randomly divided into four groups. The RPP of Groups A, B, and C were set at - 5, 0 and 5 mmHg, respectively. Conventional flexible ureteroscopy with uncontrolled pressure served as control Group D. The perfusion flow rate was set at 100 ml/min in the four groups, with 20 patients in each group. The fluid absorption was measured by 1% ethanol every 10 min. Operation time, stone-free rate, and complications were recorded. RESULT: Seventy-three patients were finally included in the RCT. The general and preoperative data of the patients were comparable between the groups. The fluid absorption of Groups A, B, and C was significantly less than that of Group D (P < 0.01). Fluid absorption and operation time were positively correlated, and the correlation coefficients R were 0.864, 0.896, 0.918, and 0.947, respectively (P < 0.01). The fluid absorption of patients with vomiting, fever and ureteral injury was greater than that of patients without complications in the four groups (P < 0.01). In different groups, fluid absorption was greater in patients with ureteral injury Post-Ureteroscopic Lesion Scale (PULS) 1-3 than in noninjured patients (P < 0.01). CONCLUSION: Flexible ureteroscopy with intelligent control of RPP effectively reduces the absorption of perfusion fluid. Operation time and ureteral injury are also key factors affecting perfusion fluid absorption. REGISTRATION NUMBER AND DATE: NCT05201599; August 11, 2021.

Risk factors of high fluid absorption in patients treated with mini-PCNL: a single-center prospective study.

BACKGROUND: The factors influencing fluid absorption in mini-percutaneous nephrolithotripsy (mini-PCNL) are still unknown. We aim to investigate the factors that influence irrigation fluid absorption during mini-PCNL. METHODS: A total of 94 patients who underwent mini-PCNL were included in this prospective study. The endoscopic surgical monitoring system (ESMS) was used to measure the volume of irrigation fluid absorbed during the procedure. Irrigating time, the total volume of irrigation fluid, stone size, S.T.O.N.E. score, hemoglobin, electrolyte levels, and postoperative complications were recorded. RESULTS: A significant correlation was observed between fluid absorption and the presence of postoperative fever, and based on this phenomenon, patients were divided into low and high fluid absorption groups. The serum creatinine level in the high fluid absorption group was significantly high (7 vs. 16.5, p = 0.02). Significant differences were observed between the low and high fluid absorption groups in terms of mean stone size (21.70 mm vs. 26.78 mm), presence of stone burden ≥ 800 mm2 (4% vs. 23%), S.T.O.N.E. score > 8 (4% vs. 38%), the fluid used > 18,596 ml (19% vs. 78%), irrigation time (55.61 min vs. 91.28 min), and perfusion rate (24% vs. 45%) (all p < 0.05). The rates of postoperative fever and SIRS in the high fluid absorption group were significantly high (p < 0.05). CONCLUSIONS: Mean stone size, presence of stone burden ≥ 800 mm2, S.T.O.N.E. score > 8, the fluid used > 18596 mL, irrigation time, and perfusion rate are risk factors of intraoperative fluid absorption in mini-PCNL.

Metabolic acidemia due to saline absorption during transurethral and transcervical surgery: a report of 2 cases.

BACKGROUND: The development of endoscopic systems that include bipolar electrocautery has enabled the use of normal saline irrigation in transurethral or transcervical endoscopic surgery. However, excessive saline absorption can cause hyperchloremic metabolic acidosis. CASE PRESENTATION: Patient 1: A 76-year-old man was scheduled for transurethral resection of the prostate with saline irrigation. Approximately 140 min after the surgery, abdominal distension and cervical edema were observed. Abdominal ultrasound examination indicated a subhepatic hypoechoic lesion, which suggested extravasation of saline. Arterial blood gas analysis revealed hyperchloremic metabolic acidosis. The patient was extubated 2 h after the operation with no subsequent airway problems, and the electrolyte imbalance was gradually corrected. Patient 2: A 43-year-old woman was scheduled for transcervical resection of a uterine fibroid with saline irrigation. When the drape was removed after the operation was finished, notable upper extremity edema was observed. Arterial blood gas analysis revealed hyperchloremic metabolic acidosis. The patient's acidemia, electrolyte imbalance, and neck edema gradually resolved, and the patient was extubated 16 h after the operation without subsequent airway problems. CONCLUSIONS: Anesthesiologists should be aware of acidemia, cardiopulmonary complications, and airway obstruction caused by excessive saline absorption after saline irrigation in endoscopic surgery.

Visualization of preimplantation uterine fluid absorption in mice using Alexa Fluor™ 488 Hydrazide†.

Uterine fluid plays important roles in supporting early pregnancy events and its timely absorption is critical for embryo implantation. In mice, its volume is maximum on day 0.5 post-coitum (D0.5) and approaches minimum upon embryo attachment ~D4.0. Its secretion and absorption in ovariectomized rodents were shown to be promoted by estrogen and progesterone (P4), respectively. The temporal mechanisms in preimplantation uterine fluid absorption remain to be elucidated. We have established an approach using intraluminally injected Alexa Fluor™ 488 Hydrazide (AH) in preimplantation control (RhoAf/f) and P4-deficient RhoAf/fPgrCre/+ mice. In control mice, bulk entry (seen as smeared cellular staining) via uterine luminal epithelium (LE) decreases from D0.5 to D3.5. In P4-deficient RhoAf/fPgrCre/+ mice, bulk entry on D0.5 and D3.5 is impaired. Exogenous P4 treatment on D1.5 and D2.5 increases bulk entry in D3.5 P4-deficient RhoAf/fPgrCre/+ LE, while progesterone receptor (PR) antagonist RU486 treatment on D1.5 and D2.5 diminishes bulk entry in D3.5 control LE. The abundance of autofluorescent apical fine dots, presumptively endocytic vesicles to reflect endocytosis, in the LE cells is generally increased from D0.5 to D3.5 but its regulation by exogenous P4 or RU486 is not obvious under our experimental setting. In the glandular epithelium (GE), bulk entry is rarely observed and green cellular dots do not show any consistent differences among all the investigated conditions. This study demonstrates the dominant role of LE but not GE, the temporal mechanisms of bulk entry and endocytosis in the LE, and the inhibitory effects of P4-deficiency and RU486 on bulk entry in the LE in preimplantation uterine fluid absorption.

Evaluation of fluid absorption during flexible ureteroscopy in an in vivo porcine model.

OBJECTIVE: To evaluate the relationship between renal pelvis pressure and fluid absorption during ureteroscopy (URS) in a live porcine model. MATERIALS AND METHODS: Flexible URS (fURS) was performed in anaesthetised female Yorkshire pigs. Prior to performing fURS, a 0.3556-mm (0.014″) pressure-sensing guidewire (Comet™, Boston Scientific) was placed to monitor renal pelvis pressure. A simulated fURS procedure was then performed for 1 h. Infusion of irrigation fluid (5% ethanol in saline) at target renal pelvis pressures (37-150 mmHg) was maintained for 1 h using a pressure bag and real-time feedback from the pressure-sensing guidewire. Venous blood was sampled every 10 min. The volume of irrigation fluid absorbed was estimated with established equations. RESULTS: A URS procedure was performed in vivo in 18 porcine kidneys and the volume of irrigation fluid absorbed during the 1 h URS was calculated. The mean (SD) volume of irrigation fluid absorbed after 1 h of simulated URS was 7.6 (5.7), 10.8 (7.1), 26.0 (15.8), and 56.8 (22.3) mL at renal pelvis pressures of 37, 55, 75, and 150 mmHg, respectively. Compared with URS with renal pelvis pressure of 37 mmHg, the volume of fluid absorption was significantly greater at renal pelvis pressures of 75 and 150 mmHg (P = 0.026 and P = 0.047, respectively). In addition, compared with URS with renal pelvis pressure of 37 mmHg, the rate of absorption was significantly greater at renal pelvis pressures of 75 and 150 mmHg (both P < 0.001). CONCLUSION: In this study of an in vivo porcine model of URS, increasing renal pelvis pressures during URS were associated with increases in irrigation fluid absorption and increases in the rate of fluid absorption.

CSF hypersecretion versus impaired CSF absorption in posthemorrhagic hydrocephalus: a systematic review.

BACKGROUND: The molecular mechanisms underlying development of posthemorrhagic hydrocephalus (PHH) remain elusive. The aim of this systematic review was to evaluate existing literature on increased CSF secretion and impaired CSF absorption as pathogenic contributors to CSF accumulation in neonatal and adult PHH. METHODS: The systematic review was conducted in accordance with the PRISMA guidelines. Relevant studies published before March 11th, 2023, were identified from PubMed and reference lists. Studies were screened for eligibility using predefined inclusion and exclusion criteria. Data from eligible studies were extracted and potential sources of bias were evaluated. RESULTS: Nineteen studies quantified CSF production rates and/or CSF absorption capacity in human patients with PHH or animals with experimentally induced PHH. Increased CSF production was reported as early as 24 h and as late as 28 days post ictus in six out of eight studies quantifying CSF production rates in animals with experimentally induced PHH. Impaired CSF absorption was reported in all four studies quantifying CSF absorption capacity in human patients with PHH and in seven out of nine studies quantifying CSF absorption capacity in animals with experimentally induced PHH. Impaired CSF absorption was reported as early as 30 min and as late as 10 months post ictus. CONCLUSIONS: The pathological CSF accumulation in PHH likely arises from a combination of increased CSF secretion and impaired CSF absorption, which may manifest at different time scales following a hemorrhagic event. Emergent evidence on increased CSF secretion by the choroid plexus may herald a paradigm shift in our understanding of PHH.

Irrigation fluid absorption during transurethral bipolar and laser prostate surgery: a systematic review.

PURPOSE: Transurethral endoscopic procedures using bipolar current, or laser energy are nowadays widely accepted and have replaced the traditional monopolar resection. A major advantage of these techniques is the utilization of isotonic saline as irrigation solution, which minimizes side effects such as symptoms associated to classical transurethral resection syndrome (TUR-syndrome). Nonetheless, clinically significant IFA also occurs with saline and is determined by pressure gradients, systemic resistance and by the amount of irrigation fluid. We aimed to investigate the extend of IFA and symptoms due to volume overload during bipolar transurethral resection (bTUR) and laser procedures of the prostate. METHODS: We performed a systematic literature search using PubMed, restricted to original English-written articles, including animal, artificial model, and human studies. Search terms were TUR, transurethral, laser, HoLEP, ThuLEP, greenlight, enucleation, fluid absorption, fluid uptake, and TUR-syndrome. RESULTS: Mean and maximum IFA during bTURP ranges between 133 and 915 ml and 1019 ml and 2166 ml, respectively. Absorption during laser procedures can be significant with maximum values up to 4579 ml and mainly occurs during prostate vaporization techniques. Incidence of moderate to severe symptoms from iso-osmolar volume overload reaches 9%. CONCLUSIONS: Irrigation fluid absorption during bTUR and laser surgery of the prostate is not negligible. Iso-osmolar overhydration with development of non-classical TUR-syndrome should be identified peri- and postoperatively and surgical teams should be aware of complications. Breath ethanol, venous pH, serum chloride, and bicarbonate could be markers for detecting dangerous events of IFA with saline.

Transurethral plasmakinetic resection versus enucleation for benign prostatic hyperplasia: comparison of intraoperative safety profiles based on endoscopic surgical monitoring system.

OBJECTIVE: To compare the intraoperative safety profiles of transurethral plasmakinetic resection of the prostate (PK-TURP) with transurethral plasmakinetic endoscopic enucleation of the prostate (PK-EEP) in the treatment of benign prostatic hyperplasia (BPH) based on endoscopic surgical monitoring system (ESMS). METHODS: A total of 128 patients who were diagnosed with BPH were stratified based on prostate volume (PV) and accepted PK-EEP or PK-TURP treatment at 1:1 ratio. The ESMS as a novel method was used to monitor blood loss and fluid absorption during the operation. Clinical parameters such as intraoperative blood loss volume, fluid absorption volume, operation time, tissue weight of resection, preoperative and postoperative red blood cell count (RBC), hemoglobin concentration (HB), hematocrit (HCT), electrolyte, postoperative bladder irrigation time, indwelling catheter time, hospital stay time and other associated complications were documented and compared between two groups. RESULTS: No significant differences in majority of baseline characteristics were observed among patients with different prostate volumes between two surgical methods. For patients with prostate volume < 40 ml, the average operation time of patients who received PK-EEP treatment was much more than those who received PK-TURP (P = 0.003). On the other hand, for patients with prostate volume > 40 ml, the PK-TURP surgery was associated with a significant increase in intraoperative blood loss (P = 0.021, in PV 40-80 ml group; P = 0.014, in PV > 80 ml group), fluid absorption (P = 0.011, in PV 40-80 ml group; P = 0.006, in PV > 80 ml group) and postoperative bladder irrigation time as well as indwelling catheter time but decrease in resected tissue weight compared to the PK-EEP treatment. CONCLUSION: The ESMS plays an important role in comparison of intraoperative safety profiles between PK-TURP and PK-EEP. Our data suggest that PK-TURP treatment is associated with a decreased operation time in patients with prostate volume < 40 ml and the PK-EEP treatment is associated with decreased intraoperative blood loss, fluid absorption and increased tissue resection for patients with prostate volume > 40 ml. Our results indicate that the size of prostate should be considered when choosing the right operation method.

The NHE3 Inhibitor Tenapanor Prevents Intestinal Obstructions in CFTR-Deleted Mice.

Mutations in the CFTR chloride channel result in intestinal obstructive episodes in cystic fibrosis (CF) patients and in CF animal models. In this study, we explored the possibility of reducing the frequency of obstructive episodes in cftr-/- mice through the oral application of a gut-selective NHE3 inhibitor tenapanor and searched for the underlying mechanisms involved. Sex- and age-matched cftr+/+ and cftr-/- mice were orally gavaged twice daily with 30 mg kg-1 tenapanor or vehicle for a period of 21 days. Body weight and stool water content was assessed daily and gastrointestinal transit time (GTT) once weekly. The mice were sacrificed when an intestinal obstruction was suspected or after 21 days, and stool and tissues were collected for further analysis. Twenty-one day tenapanor application resulted in a significant increase in stool water content and stool alkalinity and a significant decrease in GTT in cftr+/+ and cftr-/- mice. Tenapanor significantly reduced obstructive episodes to 8% compared to 46% in vehicle-treated cftr-/- mice and prevented mucosal inflammation. A decrease in cryptal hyperproliferation, mucus accumulation, and mucosal mast cell number was also observed in tenapanor- compared to vehicle-treated, unobstructed cftr-/- mice. Overall, oral tenapanor application prevented obstructive episodes in CFTR-deficient mice and was safe in cftr+/+ and cftr-/- mice. These results suggest that tenapanor may be a safe and affordable adjunctive therapy in cystic fibrosis patients to alleviate constipation and prevent recurrent DIOS.

Relevance of intravesical pressures during transurethral procedures.

PURPOSE: Endourology has undergone fundamental changes over the last 2 decades. Maintaining low intrarenal pressure (IRP) during upper urinary tract procedures is an established concept. However, researchers have not yet studied the concept of reduced intravesical pressures (IVPs) during transurethral (TUR) surgery as thoroughly. Low IVP is supposed to decrease complications as fluid retention, TUR syndrome, and incidence of fever. The study aims to give an overview of the contemporarily existing concepts and specify the term of low IVP to avoid TUR-related complications and optimize TUR-related results. METHODS: A literature search was performed using PubMed, restricted to original English-written articles, including animal, artificial model, and human studies. Different keywords were transurethral resection, transurethral enucleation, transurethral vaporization, pressure, fluid absorption, and TUR syndrome. RESULTS: Analyzed mean IVPs during TUR vary between 11 and 35 cmH2O but are mostly kept below 30 cmH2O. Mean maximum IVPs during TUR range from 20 to 55 cmH2O. Maximum IVPs seem to be lower when surgeons utilize continuous flow resection, and irrigation pressures are kept low. The results demonstrate a strong correlation between IVP levels and fluid absorption. CONCLUSIONS: IVP increase remains a neglected predictor of transurethral procedure complications, and endourologists should consider its intraoperative monitoring. Further research is necessary to quantify generated pressures and introduce means of controlling them.

[Effects of different intraoperative lithotomy positions on the absorption of irrigation fluid during bipolar plasmakinetic resection of the prostate].

OBJECTIVE: To investigate the effect of intraoperative lithotomy position (LP) with a head-down tilt (HDT) on the absorption of intraoperative irrigation fluid in patients undergoing bipolar plasmakinetic resection of the prostate (PKRP). METHODS: Eighty BPH patients underwent PKRP, 40 in a conventional 0-degree position (0° LP) and the other 40 in a －10-degree HDT position (－10° LP), with 0.9% saline containing 1% ethanol as intraoperative irrigation fluid. We determined the alcohol concentration in the exhaled breath of the patients with a digital alcohol detector at the start of the operation and every 10 minutes afterwards. Meanwhile we recorded the operation time, the volume of intraoperative intravenous crystalloid infusion and the weight of the resected prostatic tissue, monitored the mean arterial pressure (MAP) and heart rate (HR) at 5 minutes before surgery, 30 minutes after the start of surgery and the end of surgery, and measured the concentrations of Na+, K+, Cl－ and Ca2+ with an arterial blood gas analyzer at 5 minutes before surgery and 1 hour after the start of surgery. RESULTS: There were no statistically significant differences in age, height, body weight and prostate volume, or in intraoperative MAP and HR between the 0° LP and －10° LP groups. Compared with the baseline, at 1 hour after the start of PKRP, the patients in the 0° LP group showed significantly decreased concentrations of K+ (ï¼»3.64 ± 0.29ï¼½ vs ï¼»3.49 ± 0.22ï¼½ mmol/L, P = 0.002) and Ca2+ (ï¼»1.16 ± 0.03ï¼½ vs ï¼»1.13 ± 0.04ï¼½ mmol/L, P = 0.001), increased concentration of Cl－ (ï¼»106.9 ± 2.2ï¼½ vs ï¼»108.7 ± 2.3ï¼½ mmol/L, P = 0.006), but no significant difference in the concentration of Na+ (ï¼»139.7 ± 1.5ï¼½ vs ï¼»139.4 ± 1.6ï¼½ mmol/L, P = 0.231), while those in the －10° LP group exhibited remarkably decreased concentration of Ca2+ (ï¼»1.14 ± 0.04ï¼½ vs ï¼»1.13 ± 0.04ï¼½ mmol/L, P = 0.016) but no statistically significant differences in the concentrations of Na+ (ï¼»140.3 ± 1.8ï¼½ vs ï¼»140.0 ± 2.0ï¼½ mmol/L, P = 0.156), K+ (ï¼»3.49 ± 0.36ï¼½ vs ï¼»3.47 ± 0.34ï¼½ mmol/L, P = 0.506) and Cl－ (ï¼»108.2 ± 2.6ï¼½ vs ï¼»109.1 ± 2.5ï¼½ mmol/L, P = 0.071). Over 1 500 ml of intraoperative irrigation fluid absorption was observed in 6 cases (15%) in the 0° LP group as compared with 4 cases (10%) in the －10°LP group, with no significant difference between the two groups. CONCLUSIONS: Lithotomy position with a 10-degree head-down tilt can reduce PKRP-induced decrease in the concentration of K+ and increase in that of Cl－ without affecting the levels of the other electrolytes.

Human airway epithelial cells investigated by atomic force microscopy: A hint to cystic fibrosis epithelial pathology.

The pathophysiology of cystic fibrosis (CF) airway disease stems from mutations in the CF Transmembrane Conductance Regulator (CFTR) gene, leading to a chronic respiratory disease. Actin cytoskeleton is disorganized in CF airway epithelial cells, likely contributing to the CF-associated basic defects, i.e. defective chloride secretion and sodium/fluid hypersorption. In this work, we aimed to find whether this alteration could be pointed out by means of Atomic Force Microscopy (AFM) investigation, as roughness and Young's elastic module. Moreover, we also sought to determine whether disorganization of actin cytoskeleton is linked to hypersoption of apical fluid. Not only CFBE41o- (CFBE) cells, immortalized airway epithelial cells homozygous for the F508del CFTR allele, showed a different morphology in comparison with 16HBE14o- (16HBE) epithelial cells, wild-type for CFTR, but also they displayed a lack of stress fibers, suggestive of a disorganized actin cytoskeleton. AFM measurements showed that CFBE cells presented a higher membrane roughness and decreased rigidity as compared with 16HBE cells. CFBE overexpressing wtCFTR became more elongated than the parental CFBE cell line and presented actin stress fibers. CFBE cells absorbed more fluid from the apical compartment. Study of fluid absorption with the F-actin-depolymerizing agent Latrunculin B demonstrated that actin cytoskeletal disorganization increased fluid absorption, an effect observed at higher magnitude in 16HBE than in CFBE cells. For the first time, we demonstrate that actin cytoskeleton disorganization is reflected by AFM parameters in CF airway epithelial cells. Our data also strongly suggest that the lack of stress fibers is involved in at least one of the early step in CF pathophysiology at the levels of the airways, i.e. fluid hypersorption.

Report of Dramatic Improvement after a Lumboperitoneal Shunt Procedure in a Case of Anticoagulation Therapy-Resistant Cerebral Venous Thrombosis.

Cerebral venous thrombosis (CVT), which typically progresses from either acute or subacute onset, presents with symptoms related to intracranial hypertension (e.g., headache and papilledema) and brain parenchymal lesions (e.g., aphasia and hemiplegia). Anticoagulation therapy is generally accepted as a treatment for CVT and often leads to good clinical outcomes. However, we experienced a case of CVT with an uncommon clinical course. The patient was a 63-year-old man who presented with headache, papilledema, visual loss, and diplopia; his condition gradually deteriorated, and he was diagnosed with CVT via cerebral angiography. The sinus thrombus was extensive and resistant to anticoagulation therapy, and lumbar puncture revealed a progressive increase in cerebrospinal fluid (CSF) pressure. We performed a lumboperitoneal (LP) shunt procedure, which yielded marked improvement in the symptoms. The main mechanism of neurological dysfunction in CVT is venous outflow obstruction caused by venous thrombus, which results in brain edema, and/or venous infarction, which induces focal neurological signs. Another mechanism is impaired CSF absorption in the thrombosed sinuses, resulting in intracranial hypertension. We speculated that the latter mechanism strongly influenced our case, thus explaining the uncommon clinical course and effectiveness of the LP shunt procedure. Although LP shunting is not a common treatment for CVT, this case report could indicate the usefulness of this procedure for CVT with chronic progression and resistance to anticoagulation therapy.

Development of intestinal ion-transporting mechanisms during smoltification and seawater acclimation in Atlantic salmon Salmo salar.

This study investigated the expression of ion transporters involved in intestinal fluid absorption and presents evidence for developmental changes in abundance and tissue distribution of these transporters during smoltification and seawater (SW) acclimation of Atlantic salmon Salmo salar. Emphasis was placed on Na(+) , K(+) -ATPase (NKA) and Na(+) , K(+) , Cl(-) co-transporter (NKCC) isoforms, at both transcriptional and protein levels, together with transcription of chloride channel genes. The nka α1c was the dominant isoform at the transcript level in both proximal and distal intestines; also, it was the most abundant isoform expressed in the basolateral membrane of enterocytes in the proximal intestine. This isoform was also abundantly expressed in the distal intestine in the lower part of the mucosal folds. The protein expression of intestinal Nkaα1c increased during smoltification. Immunostaining was localized to the basal membrane of the enterocytes in freshwater (FW) fish, and re-distributed to a lateral position after SW entry. Two other Nka isoforms, α1a and α1b, were expressed in the intestine but were not regulated to the same extent during smoltification and subsequent SW transfer. Their localization in the intestinal wall indicates a house-keeping function in excitatory tissues. The absorptive form of the NKCC-like isoform (sub-apically located NKCC2 and/or Na(+) , Cl(-) co-transporter) increased during smoltification and further after SW transfer. The cellular distribution changed from a diffuse expression in the sub-apical regions during smoltification to clustering of the transporters closer to the apical membrane after entry to SW. Furthermore, transcript abundance indicates that the mechanisms necessary for exit of chloride ions across the basolateral membrane and into the lateral intercellular space are present in the form of one or more of three different chloride channels: cystic fibrosis transmembrane conductance regulator I and II and chloride channel 3.

Biophysical Analysis of a Minimalistic Kidney Model Expressing SGLT1 Reveals Crosstalk between Luminal and Lateral Membranes and a Plausible Mechanism of Isosmotic Transport.

We extended our model of the S1 tubular segment to address the mechanisms by which SGLT1 interacts with lateral Na/K pumps and tight junctional complexes to generate isosmotic fluid reabsorption via tubular segment S3. The strategy applied allowed for simulation of laboratory experiments. Reproducing known experimental results constrained the range of acceptable model outputs and contributed to minimizing the free parameter space. (1) In experimental conditions, published Na and K concentrations of proximal kidney cells were found to deviate substantially from their normal physiological levels. Analysis of the mechanisms involved suggested insufficient oxygen supply as the cause and, indirectly, that a main function of the Na/H exchanger (NHE3) is to extrude protons stemming from mitochondrial energy metabolism. (2) The water path from the lumen to the peritubular space passed through aquaporins on the cell membrane and claudin-2 at paracellular tight junctions, with an additional contribution to water transport by the coupling of 1 glucose:2 Na:400 H2O in SGLT1. (3) A Na-uptake component passed through paracellular junctions via solvent drag in Na- and water-permeable claudin-2, thus bypassing the Na/K pump, in agreement with the findings of early studies. (4) Electrical crosstalk between apical rheogenic SGLT1 and lateral rheogenic Na/K pumps resulted in tight coupling of luminal glucose uptake and transepithelial water flow. (5) Isosmotic transport was achieved by Na-mediated ion recirculation at the peritubular membrane.

Changes of microstructure of central serous chorioretinopathy on OCT and its relationship with prognosis.

PURPOSE: To quantitatively evaluate the relationship between retinal microstructure and prognosis in patients with central serous chorioretinopathy(CSC) using optical coherence tomography(OCT). METHODS: Three hundred and ninty-eight affected eyes of patients with central serous chorioretinopathy were included in this retrospective study. The OCT images of all patients were analyzed in baseline, and logistic regression analysis were performed with 11 independent variables, and subretinal fluid absorption in 3 months after therapy as dependent variable. The correlation between shortage of ellipsoid baseline and height of foveal subretinal fluid, width of foveal subretinal fluid were analyzed respectively. The difference of duration and baseline logMAR visual acuity in eyes with and without double layer sign or subretinal hyper-reflective materials were analyzed respectively. The difference of therapeutic outcome among different therapeutic methods was also analyzed in eyes with double-layer sign and subretinal hyper-reflective materials respectively. RESULTS: In the regression analysis with subretinal fluid absorption in 3 months after therapy as dependent variable, disintegrity of ellipsoid zone was statistically significant(P<0.0001,B=1.288). There is no correlation between disintegrity of the ellipsoid zone and the width or height of subretinal fluid. The duration of disease in eyes with double layer sign or subretinal hyper-reflective materials was longer than those without these features(P<0.001, P<0.0001). In the eyes with the double-layer sign or subretinal hyper-reflective material, the difference of logMAR visual acuity 3 months after treatment between 2 therapeutic methods was not statistically significant. CONCLUSIONS: Using optical coherence tomography to evaluate microstructure changes in eyes with central serous chorioretinopathy quantitatively, we found that subretinal fluid was easier to absorb completely in eyes with less disintegrity of ellipsoid zone. Double layer sign and subretinal hyper-reflective materials are more common in eyes with longer duration of disease.

Application of the steady-state intestinal perfusion system in measuring intestinal fluid absorption and bicarbonate secretion in vivo.

Background: The steady-state intestinal perfusion system represents a tool used in measuring intestinal fluid absorption and bicarbonate secretion in vivo; however, detailed procedures and parameters were not elucidated fully. Aim: We focused on the methods of the steady-state intestinal perfusion system comprehensively including the blood pressure, hematocrit, blood gas, and heart rate of mouse. Methods: Anesthetized, tracheally intubated, and artificially ventilated mice were used for this system. The blood pressure, hematocrit, blood gas, heart rate, and rate of fluid absorption and HCO3 - secretion of the small intestine and colon at different time points were evaluated. Results: Blood pressure, hematocrit, blood gas, and heart rate became stable at the 30 min time point after completion of surgery and could be maintained for 2 h. Rates of fluid absorption and bicarbonate secretion were also kept stable during the period of steady state of mice. Rates of fluid absorption and bicarbonate secretion were different among the jejunum, ileum, proximal, and mid-distal colon. Conclusion: The steady-state intestinal perfusion system is a reliable system for measuring intestinal fluid absorption and bicarbonate secretion in vivo.

JAK-STAT signaling as an ARDS therapeutic target: Status and future trends.

Acute respiratory distress syndrome (ARDS) is characterized by noncardiogenic pulmonary edema. It has a high mortality rate and lacks effective pharmacotherapy. With the outbreak of COVID-19 worldwide, the mortality of ARDS has increased correspondingly, which makes it urgent to find effective targets and strategies for the treatment of ARDS. Recent clinical trials of Janus kinase (JAK) inhibitors in treating COVID-19-induced ARDS have shown a positive outcome, which makes the Janus kinase/signal transducer and activator of transcription (JAK/STAT) pathway a potential therapeutic target for treating ARDS. Here, we review the complex cause of ARDS, the molecular JAK/STAT pathway involved in ARDS pathology, and the progress that has been made in strategies targeting JAK/STAT to treat ARDS. Specifically, JAK/STAT signaling directly participates in the progression of ARDS or colludes with other pathways to aggravate ARDS. We summarize JAK and STAT inhibitors with ARDS treatment benefits, including inhibitors in clinical trials and preclinical studies and natural products, and discuss the side effects of the current JAK inhibitors to reveal future trends in the design of JAK inhibitors, which will help to develop effective treatment strategies for ARDS in the future.