Spontaneous Emptying Research Articles

A dynamical calo-porosimeter to characterize wetting and drying processes in lyophobic nanometric pores.

Lyophobic heterogeneous systems, based on porous fluids made of ordered nanoporous particles immersed in a non-wetting liquid, constitute systems of interest for exploring wetting, drying, and coupled transport phenomena in nanometric confinement. To date, most experimental studies on the forced filling and spontaneous emptying of lyophobic nanometric pores, at pressures of several tens of MPa, have been conducted in a quasi-static regime. However, some studies have shown that dynamical measurements are essential to shed light on the rich physics of these phenomena. We describe here a dynamical calo-porosimeter that allows for the simultaneous mechanical and calorimetric characterization of filling and emptying cycles over four decades of timescales, ranging from a few milliseconds to 10 seconds. This thermally regulated instrument can be operated between -5 and 70°C. It also enables the study of a given porous material successively with different liquids by switching from one to another. The characterization of wetting dynamics, the study of slow kinetics due to changes in solute concentration, and the rapid measurement of the heat of wetting, among other thermal properties, are presented as examples of the possible applications of this apparatus.

Technical details and long-term outcomes of P.A.D.U.A. for congenital urethral narrowing; a case series and review of the literature

The P.A.D.U.A. technique is a method of addressing congenital urethral narrowing. It involves passive dilation with a series of progressively larger indwelling catheters. Utilization is limited by scant literature, particularly regarding technical details and long-term durability. Tools for achieving safe and reliable urinary drainage are critical in these patients, who require careful stewardship of their kidney and bladder function. To describe long-term urethral patency and urinary function following P.A.D.U.A., and to provide sufficient technical detail to reproduce the technique. Patients with congenital urethral narrowing managed with P.A.D.U.A. were identified and chart review was performed. Details of catheter exchange sequences were compiled and described. The primary outcome was the attainment of adequate urethral caliber by successful completion of P.A.D.U.A., and the secondary outcome was voiding per urethra at most recent follow-up. P.A.D.U.A. achieved adequate urethral caliber in 9/11 (82%) of patients. This included seven patients with Prune Belly Syndrome, one with isolated urethral atresia, and one with a cloacal anomaly. P.A.D.U.A. failed to achieve urethral patency in one patient with urethral duplication, who was unable to progress through the catheter sequence, and one patient with Prune Belly Syndrome, who completed P.A.D.U.A. but developed recurrent narrowing one week later. There were no delayed failures of urethral patency. Patients who achieved patency underwent a median of seven catheter placements over 92 days. Median (range) initial and final catheter sizes were 3.5F (1.9-8F) and 14F (8-16F). While 82% achieved patency, only 3/11 (27%) were voiding spontaneously per native urethra at most recent follow-up. This series of patients undergoing P.A.D.U.A. for primary treatment of congenital urethral narrowing is the largest to date and provides granular technical details. It aligns with prior reports suggesting that P.A.D.U.A. achieves urethral patency in most patients with Prune Belly Syndrome or isolated urethral atresia, but has limited application in the hypoplastic duplicated urethra. Despite high rates of urethral patency in this select population, many patients will not achieve and maintain spontaneous voiding without catheterization. This is likely due to ongoing deterioration of bladder function caused by the prenatal developmental insult, paralleling the phenomenon seen in posterior urethral valves. P.A.D.U.A. is an effective and durable technique for achieving urethral patency. However, due to complicating factors such as the underlying bladder pathology present in many patients, urethral patency achieved with P.A.D.U.A. does not guarantee long-term safe and reliable spontaneous emptying per urethra.

Профилактика и лечение пареза кишечника у детей

Dynamic intestinal obstruction (DIO) is one of the disorders reported after gastrointestinal (GI) surgical procedures. DIO raises special concerns, as it affects patients’ condition in the postoperative period and increases the duration of hospital treatment. The review section of the article is focused on DIO pathogenetic mechanisms, clinical manifestations, diagnostic criteria, and treatment strategies. In addition to diet therapy and the use of cholinesterase inhibitors, the conservative therapy in children includes various physiotherapy treatment techniques, facilitating intestinal motility The comparative analysis shows that their ultimate efficiency is not the same and that there are significant limitations and differences associated with the access to the optimal areas for electrode placement The article presents the results of introducing an original technique of dynamic electrical stimulation of the intestine with point paravertebral massage which was used in the early postoperative period for 117 children. The children had undergone either emergency surgeries in cases of acute surgical conditions or planned (stage-by- stage) intestinal reconstruction surgeries for preventing DIO.The data have demonstrated the efficacy of electrical stimulation used both as monotherapy and in combination with proserine (the number of required injections was decreased to 1 or 2). Restoration of the intestinal passage was achieved in 95% of cases within the first 24–36 hours after surgery (spontaneous defecation occurred in 70% of patients by the end of the first day). A later response to electrical stimulation with the restoration of peristalsis was determined after small intestine surgeries: spontaneous emptying of the intestine on the first day occurred only in 43% of children versus 52% after surgery of the lower portion of the abdominal cavity KEYWORDS: postoperative intestinal paresis; children; clinical course; diagnostics; electrical stimulation; original technique; acupressure device FOR CITATION: Pen’tkovskaya O.S., Bardenikova S.I. Prevention and treatment of enteroparesis in children. Russian Journal of Woman and Child Health. 2022;5(4):373–381 (in Russ.). DOI: 10.32364/2618-8430-2022-5-4-373-381.

Index of SuspicionCase 1: Acute Urinary Retention in a 13-month-old BoyCase 2: Depression in the Scalp of a 5-year-old BoyCase 3: Acute Onset of Abnormal Behavior in a 16-year-old BoyCase 4: Dark Urine in a 2-year-old Boy

A 13-month-old white boy presents to the emergency department (ED) with sudden onset of abdominal discomfort and lethargy. There is no history of fevers, vomiting, or diarrhea. He was born at 39 weeks’ gestation by spontaneous vaginal delivery. He has had no surgery, and he does not take any medications. His immunizations are up to date and he is developmentally appropriate. Some older family members have had gastric, uterine, and cervical cancers. Physical examination reveals a crying but consolable child. He is afebrile with a heart rate of 123 beats per minute, blood pressure of 107/60 mm Hg, respiratory rate of 37 breaths per minute, and oxygen saturation of 97% on room air. His abdomen is soft and nontender, with mild guarding; there are no masses or hepatosplenomegaly. Neurologic examination reveals normal strength and deep tendon reflexes. A rectal examination is deferred because of parental request. His laboratory results reveal a serum sodium level of 134 mmol/L, potassium of 4.4 mmol/L, chloride of 105 mmol/L, bicarbonate of 13 mmol/L, blood urea nitrogen of 83 mg/dL, creatinine of 5.4 mg/dL, glucose of 98 mg/dL, calcium of 8.6 mg/dL, and lipase of 24 U/L. The complete blood count is normal for age, and urinalysis on a catheterized specimen shows moderate occult blood, but is negative for protein, leukocyte esterase, or nitrites. He receives intravenous fluids to correct his pre-renal kidney failure. Subsequently, he develops urinary retention that requires frequent urinary catheterizations. Renal ultrasonography shows bilateral hydronephrosis, and a voiding cystourethrogram shows two small bladder diverticulae and the absence of spontaneous emptying of the bladder. An advanced imaging study reveals the diagnosis. A 5-year-old boy is brought to the clinic by his new foster mother for evaluation of a depression in his scalp noticed recently during bathing. The child has been living in …

Successful Transtracheal Lung Ventilation Using a Manual Respiration Valve

Lung ventilation through a thin transtracheal cannula may be attempted in patients with laryngeal stenosis or "cannot intubate, cannot ventilate" situations. It may be impossible to achieve sufficient ventilation if the lungs are spontaneously emptying only through the thin transtracheal cannula, which imposes high resistance to airflow, resulting in dangerous hyperinflation. Therefore, the authors describe the use of a manual respiration valve that serves as a bidirectional pump providing not only inflation but also active deflation of the lungs in case of emergency transtracheal lung ventilation. The effectiveness of such a valve was tested in vitro using mechanical lungs in combination with two different cannula sizes and various gas flows. The valve was then tested in five pigs using a transtracheal 16-gauge cannula with three different combinations of inspiratory/expiratory times and gas flows and an occluded upper airway. In the mechanical lungs, the valve permitted higher minute volumes compared with spontaneous lung emptying. In vivo, the arterial oxygen and carbon dioxide partial pressures increased initially and then remained stable over 1 h (arterial oxygen tension, 470.8 +/- 86.8; arterial carbon dioxide tension, 63.0 +/- 7.2 mmHg). The inspiratory pressures measured in the trachea remained below 10 cm H2O and did not substantially influence central venous and pulmonary artery pressures. Mean arterial pressure and cardiac output were unaffected by the ventilation maneuvers. This study demonstrated in vitro and in vivo in adult pigs that satisfactory lung ventilation can be assured with transtracheal ventilation through a 16-gauge cannula for a prolonged period of time if combined with a bidirectional manual respiration valve.

Bubbles, Gating, and Anesthetics in Ion Channels

We suggest that bubbles are the bistable hydrophobic gates responsible for the on-off transitions of single channel currents. In this view, many types of channels gate by the same physical mechanism—dewetting by capillary evaporation—but different types of channels use different sensors to modulate hydrophobic properties of the channel wall and thereby trigger and control bubbles and gating. Spontaneous emptying of channels has been seen in many simulations. Because of the physics involved, such phase transitions are inherently sensitive, unstable threshold phenomena that are difficult to simulate reproducibly and thus convincingly. We present a thermodynamic analysis of a bubble gate using morphometric density functional theory of classical (not quantum) mechanics. Thermodynamic analysis of phase transitions is generally more reproducible and less sensitive to details than simulations. Anesthetic actions of inert gases—and their interactions with hydrostatic pressure (e.g., nitrogen narcosis)—can be easily understood by actions on bubbles. A general theory of gas anesthesia may involve bubbles in channels. Only experiments can show whether, or when, or which channels actually use bubbles as hydrophobic gates: direct observation of bubbles in channels is needed. Existing experiments show thin gas layers on hydrophobic surfaces in water and suggest that bubbles nearly exist in bulk water.

Preduodenal mechanisms in initiating gallbladder emptying in man.

The existence of preduodenal phases of gallbladder emptying in normal volunteers was investigated by evaluating the effect of sham feeding a sandwich (chew and spit) (n = 15), the sight and smell of food followed by sham feeding a cooked meal (n = 15), and gastric distension (intragastric balloon tube) (n = 9) on gallbladder emptying and comparing these responses with those after ingestion of a standard meal (n = 14). A control group given no intestinal stimuli were studied to determine the frequency of spontaneous emptying during fasting (n = 18). 99mTc-EHIDA (2,6 diethylphenylcarbamoylmethyliminodiacetic acid) was used as the biliary tracer. The frequency of gallbladder emptying during fasting was 0.0045/min. Thus, in any 20 min period emptying occurred spontaneously in only about 1 in 11 volunteers. Significant emptying (greater than 5 per cent over 20 min) occurred in 8 out of 15 volunteers after sham feeding a sandwich (P less than 0.001 versus control), in 8 out of 15 volunteers after sham feeding a cooked meal (P = 1.0 versus sandwich sham feed, n.s.), in 6 out of 9 volunteers after gastric distension (P less than 0.001 versus control) and in 14 out of 14 volunteers after meal ingestion. The rate of emptying was significantly greater in the gastric distension and meal ingestion groups compared with other groups (P less than 0.05). However, the emptying rate after sham feeding was not significantly different from spontaneous gallbladder emptying (P greater than 0.05, n.s.). There was no significant difference in time to onset of emptying between the four stimulus groups (P greater than 0.05, n.s.). These results suggest that pre-duodenal stimuli can evoke gallbladder emptying in man, although the precise physiological significance of this phenomenon remains to be established.

Surgical Correction of Pyelo-Ureteral Junction Desease on Graft before Kidney Transplantation

Before kidney transplantation, even without ultrasound alterations of donor urinary tract, we usually and carefully study kidney to be transplanted. We fill urinary tract retrogradly with physiological solution from distal ureter. With this method we can recognise stenosis, ectasis and, during a spontaneous emptying, an altered urinary flow due to a “pyelo-ureteral junction attitude”. After kidney transplantation, in fact, hyperdiuresis can unmask a pyelo-ureteral junction attitude with heavy functional rebounds. When, during graft's preparation, we recognize an altered flow, we operate it “on the bank” in order to a easier surgery than on a transplanted kidney, because of its site in iliac fossa, vascular anastomosis and fibrosis that will establish early. We don't use traditional pyeloplastic technique (Anderson Hynes). We use easier pyeloplastic techniques Y-V sec. Foley. Than we apply a ureteral catheter JJ Ch 6 to protect suture and finally we vitrify the suture with fibrin glue. Recently we operated on bank with pyeloplastic technique Y-V sec. Foley a kidney without pyelo-ureteral flow. After ureteral catheter removal, kidney scintigrafy show normal morphology and functionality of graft. Follow-up show a normal urinary flow and kidney function.

Early evolution of bladder emptying after myelomeningocele closure

Objectives. To analyze bladder emptying in newborns with spina bifida after closure of the myelomeningocele defect. Manipulation of the spinal cord and nerve roots results in temporary changes in bladder function in many settings. Methods. We reviewed 62 consecutive newborn patients who underwent closure of a myelomeningocele defect at our institution from January 1990 to December 1997. We examined the catheterized urine volumes obtained before and after closure, radiographic and urodynamic studies, and the subsequent need for intermittent catheterization. Poor bladder emptying was defined as most catheterized urine volumes greater than 10 mL (20% of expected bladder capacity). Adequate follow-up was available for 54 patients for a period of 4 to 96 months (mean 42). One patient with posterior urethral valves was excluded from the study, leaving 53 for evaluation. Results. Of the 53 patients, 4 with high outflow resistance and dyssynergy never emptied the bladder adequately before or after closure. Of the remaining 49 patients, 6 (12%) emptied well immediately after the myelomeningocele repair. In the other 43 (88%), the bladder did not empty as well after closure. The mean volume obtained with catheterization after closure was 20 mL, significantly higher ( P <0.001) than the mean volume obtained before repair (6.5 mL) or after resumption of better spontaneous emptying (4 mL). Intermittent catheterization done for poor emptying was required for an average duration of 11 days (range 2 to 42). Of the 43 patients with poor emptying immediately after closure, 32 (74%) required catheterization for 2 weeks or less; the remaining 11 (26%) required catheterization for 2 to 6 weeks. Despite the relatively early resumption of good emptying, numerous patients (19 of 49) required additional intervention (clean intermittent catheterization or vesicostomy) before attempts to toilet train. Conclusions. A clinical pattern similar to spinal shock does occur in most newborns after closure of a myelomeningocele defect. Resumption of near-complete emptying usually occurs less than 2 weeks after repair but may require up to 6 weeks.

Analysis of motor patterns in the isolated guinea-pig large intestine by spatio-temporal maps.

We investigated and quantified the spontaneous patterns of motility in the isolated guinea-pig proximal and distal colon taken from adult animals. During spontaneous emptying, profiles of proximal and distal colon were recorded with a video camera, and image analysis was used to construct spatio-temporal maps of the motions of the intestinal wall. Four patterns of motility were recorded. In the proximal colon there were neurally mediated contractions that propagated in the aboral direction at 4.1 mm s(-1), gently pushing the soft contents aborally; these are likely to represent spontaneous peristaltic behaviour. A second pattern, insensitive to tetrodotoxin (TTX; 0.6 microM), consisted, in both oral and aboral propagation, of shallow contractions of the circular muscle (ripples). These contractions propagated aborally at 2.8 +/- 0.45 mm s(-1) and orally at 2.03 +/- 0.31 mm s(-1) (n=10). Of these TTX-resistant contractions, 22.5% propagated both orally and aborally from a common origin. The orally propagated component of these myogenic contractions is likely to correspond to the antiperistalsis widely described in the proximal colon. In the distal colon, two patterns of motor activity were observed. One, induced by natural or artificial pellets, consisted of peristaltic contractions that pushed the pellets aborally at 0.8 mm s(-1) and expelled a pellet every 108 s. In the interval between pellet propulsion and after the distal colon had emptied all of its pellets a second, nerve-mediated pattern of motor activity, consisting of clusters of annular circular muscle contractions separated by short dilated regions, slowly propagated aborally at 0.3 mm s(-1). Both of these motor patterns were abolished by TTX (0.6 microM). A latex balloon, inserted at the oral end of the empty isolated distal colon and inflated to a size similar to faecal pellets, was propelled at 1.4 mm s(-1). Epoxy resin-covered natural pellets were propelled at a similar speed of 1.6 mm s(-1). Our data revealed that myogenic and neurogenic patterns of propagated contractions in the colon occur in isolated preparations and are involved in emptying the colon.

Different and common intracellular calcium-stores mobilized by noradrenaline and caffeine in vascular smooth muscle.

Noradrenaline (NA) 1 microM and caffeine (CAF) 10 mM induce a contractile response in isolated rat aorta maintained at 37 degrees C either in the presence or absence of extracellular calcium. In Ca-free media the contractile response was reduced and contractile activity of CAF only occurred at 25 degrees C. NA induced a biphasic response in Ca-free medium, with a fast phasic contraction followed by a smaller more sustained contraction. The response induced by CAF consisted of a fast transient contraction which returned to a level below the resting tone. After washing, further addition of NA or CAF evoked no increase in smooth muscle tension. The influence of Mg-depletion in the extracellular medium on the contractile responses induced by NA and CAF in Ca-free medium was determined: similar response to NA or CAF in media with or without Mg after 2 min loading were observed, but after 15 min loading in Mg, Ca-free solution, the responses to NA or CAF were significantly higher than after incubation in Ca-free medium containing Mg. Differences were observed when contractile response to NA was elicited after the refilling process by loading the aortic strip in Ca-containing Mg-free solution. In this case, instead of recovering the magnitude of contraction there was a significant decrease. The existence of two independent intracellular Ca-pools releasable by NA, one of them also sensitive to CAF, is postulated. The refill of the Ca-store specific to NA is dependent on the presence of Mg in the extracellular medium. In contrast, the refill of the common Ca-pool releasable by NA and CAF is independent of the extracellular Mg, but its spontaneous emptying is temperature-, and Mg-dependent. This suggests the intermediacy of an enzymatic process to extrude the Ca-content of this store to the extracellular space.

Functional Results of Gastric Interposition Following Total Esophagectomy

Functional results of gastric interposition were evaluated in 35 patients at 3 to 84 months following esophagectomy. All patients were satisfied with the results of surgery, although 14 (40%) still experienced some degree of dysphagia. Transit times for radiolabeled solids across the cervical esophagus and anastomosis were not significantly different for the 14 symptomatic patients (mean 77 seconds) versus 21 asymptomatic patients (mean 55 seconds). Spontaneous emptying of the vagotomized intrathoracic stomach appeared complex, with mean percentage radionuclide clearances at 30 minutes (semisolid meal) calculated at 37% for 23 patients with early satiety (versus 42% asymptomatic) and at 38% for nine patients with reflux (versus 39% asymptomatic), all values comparable to emptying of the normal intra-abdominal stomach (35% clearance at 30 minutes). Our data suggest that the interposed stomach appears to retain its gastric identity rather than act as an inert conduit, and that although little correlation exists between postoperative symptoms and objective findings, the stomach remains a satisfactory esophageal substitute.

Some bioelectrical properties of Amoeba proteus.

AbstractThe membrane potential, resistance and capacitance of Amoeba proteus was measured with intracellular microelectrodes. Specific membrane resistance was 3 700 ohmcm2 and membrane ca pacitance 1.9 μ/cm2. Resting membrane potential during culture conditions was 65 pL 1.3 mV inside negative. Potassium and sodium ions decreased the membrane potential 40 and 35 mV per tenfold increase of external concentration. Substitution of chloride for ethanesulphonate did not affect the membrane potential. A transient biphasic shift of membrane potential and decrease of membrane resistance simultaneous with the spontaneous emptying of the contractile vacuole was recorded. The hyperpolarizing component of this potential was evaluated in the light of a positive potential recorded during the impalement of the vacuolar membrane and the subsequent emptying of the vacuole. All agents with ability to induce pinocytosis which were tested caused a transient “burst” of depolarizing potentials before a steady depolarized state was established. Anionic compounds did not depolarize the membrane. It is suggested that the permeability of the cell membrane is largely governed by negatively charged groups of the mucopolysaccharide layer of the membrane.

Reaction of Gall-Bladder to Faradic Stimulation of Stomach.

In a previous publication attention was called to a case of spontaneous emptying of the human gall bladder during fasting, in which the patient reported the occurrence of hunger pangs during the interval in which cholecystograms were recording a marked reduction in size of the gall bladder.1 This was interpreted as being in harmony with Boldireff's observations that during fasting, bladder bile is discharged into the duodenum synchronously with gastric hunger contractions.Very recently, we have observed rhythmic tonus changes of the gall bladder, in fasting cats, that are concurrent with rhythmic peristaltic contractions of the stomach. These observations, made on unanesthetized animals 7 to 10 hours after operation, were recorded by series of x-rays taken at intervals of 30 seconds—the gall bladder being visualized by roentgen-opaque oil, and the stomach by its content of air. The intervals between phases, as well as the duration of the contraction waves (1 to 3 minutes), seem to correspond to the period...