bluuebunny/crossref_metadata_2025 huggingface dataset:
Rapid Synthesis of Chiral Figure‐Eight Macrocycles Using a Preorganized Natural Product‐Based Scaffold
Authors: Honda Tasuku , Ogata Daiji , Tsurui Makoto , Yoshida Satoshi , Sato Sota , Muraoka Takahiro , Kitagawa Yuichi , Hasegawa Yasuchika , Yuasa Junpei , Oguri Hiroki
Published: January 2024

Chiral D2‐symmetric figure‐eight shaped macrocycles are promising scaffolds for amplifying the chiroptical properties of π‐conjugated systems. By harnessing the inherent and adaptable conformational dynamics of a chiral C2‐symmetric bispyrrolidinoindoline (BPI) manifold, we developed an enantio‐divergent modular synthetic platform to rapidly generate a diverse range of chiral macrocycles, spanning from 14‐ to 66‐membered rings, eliminating the need for optical resolution. Notably, a 32‐membered figure‐eight macrocycle showed excellent circularly polarized luminescence (CPL: |glum|=1.1×10−2) complemented by a robust emission quantum yield (Φfl=0.74), to achieve outstanding CPL brightness (BCPL: ϵ×Φfl×|glum|/2=480). Using quadruple Sonogashira couplings, this versatile synthetic platform enables precise adjustments of the angle, distance, and length among intersecting π‐conjugated chromophores. Our synthetic strategy offers a streamlined and systematic approach to significantly enhance BCPL values for a variety of chiral D2‐symmetric figure‐eight macrocycles.
Kinetics and thermal properties of polydiethylsiloxane initiated by potassium trimethylsilanolate
Authors: Ji Yanwei , Zhao Yan , Xu Rui , Dai Lina , Zhang Zhijie , Fei Hua‐Feng
Published: January 2024

This work reports the kinetics of anionic ring‐opening polymerization of hexaethylcyclotrisiloxane (D3Et) with potassium trimethylsilanolate as initiator and diglyme and N,N‐dimethylformamide (DMF) as promoters. The polymerization rate of D3Et is influenced by the nature of promoters and the reaction temperatures. With the use of DMF as a promoter, the polymerization activation energy is 107.89 kJ/mol, and the polymerization rate constant at 110°C is 0.08466 min−1 with [P]/[I] = 3.0. Gel permeation chromatography and 29Si NMR spectra showed that the intermolecular redistribution occurred during the late stage of polymerization, which facilitated the synthesis of high‐molecular‐weight polydiethylsiloxane (PDES). Differential scanning calorimetry analysis showed that PDES exhibited a glass transition temperature of −142°C and complex crystallization phenomena. Thermogravimetric analysis illustrated that the PDES that was prepared using this method had good thermal stability with onset decomposition temperatures of 483 and 452°C under nitrogen and air conditions, respectively. This work presents innovative approaches for achieving a more energy‐efficient synthesis of PDES to meet the demands of industrial‐scale production.
Dependence of the Al Distribution in CHA Zeolite on the Presence of Na+ during the Synthesis. An EPR Investigation of Cu Species in CuCHA
Authors: Gao Qi , Nielsen David , Mossin Susanne
Published: January 2024

Copper‐exchanged zeolites, such as CuCHA are active catalysts for removing NO and NO2 from automotive exhaust. The zeolite synthesis is decisive for the aluminium distribution in the framework and the properties of the catalyst. We have applied in‐situ EPR spectroscopy on CuCHA based on CHA synthesized in four different ways. We found that different mineralizing agents led to differences in the Cu distribution in the final product. Several distinct Cu sites were present after thermal activation according to the EPR spectra and we found that the presence of Na+ during the synthesis boosted the forming of “paired” Al close to Cu, but at the same time limited the ion‐exchange capacity and the redox activity. Two types of well‐defined EPR spectra were found, Site A and Site B. Site B was redox active and catalytically active for all investigated materials whereas the properties of Site A depended on the CHA material and consisted of two subtypes distinguished by their reactivity towards NO and NH3. Studies with isotope labeled NH3 showed that the system was highly dynamic. In‐situ EPR was proved to be an excellent spectroscopic technique to investigate the Cu distribution directly and investigate the Al distribution indirectly for CuCHA zeolites.
A Two‐dimensional Metal‐Organic Framework as Promising Cathode for Advanced Lithium Storage
Authors: Zhou Anna , Zheng Junyang , Lei Chengxi , Liang Jiaying , Deng Xiaotong , Wu Zetao , Chuangchanh Phaivanh , Chen Qing , Zeng Ronghua
Published: January 2024

Anthraquinone electrode materials are promising candidates for lithium‐ion batteries (LIBs) due to the abundance of anthraquinone and the high theoretical capacity, and good reversibility of the anthraquinone electrodes. However, the active anthraquinone materials are soluble in organic electrolytes, resulting in a sharp decay of capacity during the charge and discharge processes. Herein, we report on a two‐dimensional calcium anthraquinone 2,3‐dicarboxy metal‐organic framework (2D CaAQDC MOF) fabricated using a simple hydrothermal method. The 2D CaAQDC MOF not only effectively inhibits the dissolution of active electrode substances into the electrolyte, but also promotes the diffusion of lithium ion into the pores of the MOF. When used as a cathode for the LIBs, the resulting CaAQDC electrode delivers a high specific capacity of ~100 mAh g−1 at a current density of 50 mA g−1 after 200 cycles, demonstrating its good cycle stability. Even at a high current density of 200 mA g−1, the CaAQDC electrode exhibits a specific capacity of ~60 mAh g−1. The fabricated 2D coordination polymers effectively restrains the dissolution of anthraquinone into the organic electrolyte and enhances the structural stability, which greatly improves the electrochemical performance of anthraquinone. These research results offer a rational molecular design strategy to address the dissolution of this and other active organic electrode materials.
Pharmacokinetics‐Bridging Between Autoinjectors and Prefilled Syringes for Subcutaneous Injection: Case Examples Revealing a Knowledge Gap
Authors: Li Zhe , Du Xiulian , Huang Shiew Mei , Wang Yow‐Ming C.
Published: January 2024

Comparative pharmacokinetics (PK) studies have efficiently served as the bridge between autoinjectors and prefilled syringes given the underlying principles that comparable exposure could translate to comparable efficacy and safety. This article discusses approaches used to address uncertainties associated with the observation of noncomparable PK leading to the successful introduction of new autoinjector devices for monoclonal antibody and Fc‐fusion protein products. Information from seven case examples suggests a knowledge gap that warrants attention in autoinjector development.
About the quantum‐kinetic derivation of boundary conditions for quasiparticle Boltzmann equations at interfaces
Authors: Bronold F. X. , Willert F.
Published: January 2024

Quite a many electron transport problems in condensed matter physics are analyzed with a quasiparticle Boltzmann equation. For sufficiently slowly varying weak external potentials it can be derived from the basic equations of quantum kinetics, provided quasiparticles can be defined and lead to a pole in the quantum‐mechanical propagators. The derivation breaks down, however, in the vicinity of an interface which constitutes an abrupt strong perturbation of the system. In this contribution we discuss in a tutorial manner a particular technique to systematically derive, for a planar, nonideal interface, matching conditions for the quasi‐particle Boltzmann equation. The technique is based on pseudizing the transport problem by two auxiliary interface‐free systems and matching Green functions at the interface. Provided quasiparticles exist in the auxiliary systems, the framework can be put onto the semiclassical level and the desired boundary conditions result. For ideal interfaces, the conditions can be guessed from flux conservation, but for complex interfaces this is no longer the case. The technique presented in this work is geared toward such interfaces.
Dendritic bifunctional nanotraps inside SBA‐15 for highly efficient removal of selected nonsteroidal anti‐inflammatory drugs from wastewater
Authors: Zhu Lixuan , Gou Xiaoyi , Zheng Yajun , Zhang Zhiming , Huang Yajie , Zhang Yan , Li Yun , Zhang Zhiping
Published: January 2024

Large‐pore mesoporous SBA‐15 materials were functionalized with dendritic bifunctional ligands to achieve efficient adsorption of nonsteroidal anti‐inflammatory drugs (NSAIDs) in aqueous solution mainly through a combination of anion‐exchange ability of quaternary ammonium cations and π‐π interaction capability of oxygen activated phenyls. The synthesis of such a dendritic ligand starts from propylamine on SBA‐15 followed by consecutive amine‐epoxy reactions with resorcinol diglycidyl ether (RDGE) and methylamine, and then amination of terminal epoxy with trimethylamine. The results from Fourier‐transform infrared spectroscopy, nitrogen adsorption–desorption measurements and elemental analysis reveal that the bifunctional dendritic nanotraps have been created successfully inside the mesochannels of SBA‐15 (DNT@SBA‐15). Adsorption kinetics for NSAIDs was very rapid following a pseudo‐second‐order kinetic model, and adsorption isotherms were fitted well by the Langmuir isotherm model. Notably, DNT@SBA‐15 demonstrated remarkably high adsorption capacities for NSAIDs, with maximum values of 1037.3 mg g−1 for ibuprofen, 821.3 mg g−1 for naproxen and 781.3 mg g−1 for diclofenac at pH 7.0. The adsorption was presumed to be governed by a dual‐interaction mechanism including electrostatic and van der Waal's interactions. This study demonstrates that the developed dendritic anion‐exchanger can be a promising material for removing NSAIDs adsorption from environmental water.
Novel design and adaptive coordinated energy management of hybrid fuel‐cells/tidal/wind/PV array energy systems with battery storage for microgrids
Authors: Belkhier Youcef , Oubelaid Adel
Published: January 2024

This paper proposes a comprehensive solution to the challenges of managing a hybrid microgrid that generates electricity from multiple sustainable energy sources by proposing a coordinated energy management strategy and storage system. As renewable energy generation becomes increasingly popular, it introduces greater intermittency and stochasticity in energy management. To address this issue, a coordinated energy management strategy and storage system is proposed, which includes a fuzzy logic modified super twisting algorithm (MSTA). The objectives are to optimize the design and operation of microgrid including electrical based energy conversion systems such as photovoltaic and wind turbines, fuel cells, tidal energy, electric vehicle charging stations, and main grid. The second objective is to develop an energy management system for hybrid energy storage systems (HESS) and renewable energy sources (RESs) to maximize power production and ensure service continuity and smooth output energy of the microgrid, while also providing optimal benefits. To maintain cost‐effectiveness, an On/Off maximum power point tracking (MPPT) algorithm is also proposed. The contribution of this paper is to provide a solution to the intermittent and stochastic nature of renewable energy management and to improve the efficiency and durability of the energy conversion systems. The proposed management unit provides consistent output power and long‐term service.
Heat and mass transfer under MHD mixed convection in a four‐sided lid‐driven square cavity
Authors: Patel Arvind , Kumar Manoj , Bagai Shobha
Published: January 2024

This paper investigates the heat and mass transfer under magnetohydrodynamic mixed convection flow of a binary gas mixture in a four‐sided lid‐driven square cavity. The enclosure's left wall is sinusoidally heated and acts as a source term, while the right wall functions as a sink. The cavity's horizontal walls are adiabatic and impermeable to mass transfer. The governing equations under Boussinesq approximation and stream function‐vorticity formulation are solved using the alternating‐direction‐implicit scheme, a finite‐difference method. The numerical scheme's consistency and stability are demonstrated using the matrix method. The MATLAB code is written, validated against some existing studies, and used to perform numerical simulations. The numerical solutions are graphically examined by visualizing the streamline, isotherm, and concentration contours for nondimensional parameters, such as Hartmann number , heat absorption or generation coefficient , Richardson number , and buoyancy ratio . The magnetic field modifies the temperature and concentration distribution in the cavity, depending on the convection mode. The magnetic field forces the fluid to stagnate in different regions of the cavity, depending on the mode of convection. It was found that the difference between the maximum and minimum temperature and concentration at the cavity's midpoint increases up to 13 and 10 times, respectively, in the natural convection compared with the forced convection. The average Nusselt number on the vertical walls of the cavity is maximum in natural convection in the absence of a magnetic field but reaches a minimum value at in forced and mixed convection. The average Sherwood number on the cavity's vertical walls decreases with the magnetic field in mixed and natural convection.
Superconducting Quasicrystals
Authors: Takemori Nayuta
Published: January 2024

Dan Shechtman's discovery of quasicrystals in 1982 introduced the scientific world to aperiodic crystals with unique rotational symmetries, redefining traditional crystallography. Although superconductivity in related periodic approximants has since been observed, true bulk superconductivity in quasicrystals was confirmed only in 2018. This recent discovery opens a new horizon not only for the study of correlated quasicrystals but more generally for the study of superconductivity with nontrivial spatial order. The theoretical understanding of superconducting quasicrystals poses challenges due to their lack of periodicity. Notably, they exhibit non‐BCS type superconductivity and distinct electromagnetic responses, reminiscent of the so‐called FFLO state. In this review, we provide an overview of superconducting quasicrystals, along with some “behind‐the‐scenes” information.
Reserve Bilirubin Binding Capacity Determined by Difference Spectroscopy. I. Modifications and Performance of the Difference Spectroscopy Assay
Authors: Burckart Gilbert J. , Whitington Peter F. , Gross Sharon R.
Published: January 2024

The difference spectroscopy assay for reserve bilirubin binding capacity, modified to improve its performance, was used to study solutions of human serum albumin and bilirubin. The results indicate that the assay is performed simply and rapidly: that it uses very small sample volumes, making it suitable for use in premature human neonates; that it measures reserve binding capacity and not free bilirubin resulting from exceeding binding capacity; that it measures binding at two sites, which can be discriminated by blocking the low‐affinity site with concentrated salicylate: and that it can be performed at varying pH depending upon the experimental need.
Pyloric Channel Duplication in a Newborn Infant
Authors: Birenbaum Emanuel , Avigad Itamar , Bat Leon , Rozenman Judith , Brish Michael
Published: January 2024

This is the first reported case of pyloric channel duplication demonstrated preoperatively by endoscopy and contrast radiography. Endoscopically, the lesion resembled a mucosal flap overlying the pyloric orifice. On radiography the lesion presented as a polypoidal filling defect in the duodenal bulb. The infant had, in addition, postduplication stress ulcer.
Cholestasis and Total Parenteral Nutrition
Authors: Zahavi I. , Gall D. G. , Shaffer E. A.
Published: January 2024

The effect of total parenteral nutrition (TPN) on bile formation was evaluated in 10 studies performed on three adult dogs. The bile duct was directly cannulated via a Thomas cannula while bile salt secretion was maintained by intravenous [14C]taurocholic acid infusion. After a 1.5‐h basal period, either an amino acid solution (2.5% Travasol$rG) with 10% glucose, or a lipid emulsion (10% Intralipid$rG) was added intravenously for 2 h, followed by a second control period. The amino acid‐glucose solution resulted in a significant (p < 0.05) increase in bile flow which rose (+33%) while bile salt secretion increased transiently (+11%) and then returned to basal levels. The specific activity of taurocholate secreted did not decrease during the amino acid‐glucose infusion, indicating that the unexpected increase in bile salt secretion was mainly due to a washout of the biliary tree rather than to enhanced synthesis. Cholesterol, phospholipid, and bilirubin outputs did not change significantly. Intralipid had no effect on bile flow or solute secretion. Thus, short‐term TPN therapy with amino acids and glucose had no cholestatic effect in dogs, but rather produces a transient choleresis which is largely independent of bile salts.
Hepatic Abscess as a Complication of Crohn's Disease
Authors: Weinberg Robert J. , Klish William J. , Brown Marilyn R. , Smalley James R. , Emmens Robert W.
Published: January 2024

A 17‐year‐old male with Crohn's disease presented with persistent fever and right upper quadrant tenderness. Ultrasonography and abdominal computerized axial tomography (CAT scan) showed two large loculated abscess cavities in the right lobe of the liver. Surgical drainage and antibiotic therapy led to resolution of both cavities over a 5‐month period. Unlike six previously reported patients, our patient had no evidence of pylephlebitis or mesenteric abscess formation at surgery. We speculate that his abscesses arose through seeding of mesenteric vessels and portal bacteremia.
Aluminum Hydroxide in the Symptomatic Treatment of Infants with Chronic Diarrhea
Authors: Moylan Fergus M. B.
Published: January 2024

Two neonates with milk intolerance and two older infants, one with acute gastroenteritis and the other with prolonged malnutrition, developed chronic diarrhea. Despite bowel rest, total parenteral nutrition, and alterations in the protein and carbohydrate content of the milk preparations used, every attempt to feed them resulted in diarrhea. All four patients were given aluminum hydroxide because of its bile salt‐binding activity and its tendency to cause constipation. Coincident with its administration the diarrhea stopped and the enteral feedings were successfully reinstituted. The only complication seen was the development of constipation in two of the infants: this responded to lowering of the dose of the aluminum hydroxide.
Bacteriological Analysis of Jejunostomy Fluid After Surgery for Extrahepatic Biliary Atresia
Authors: Leblanc Antoine , Lambert‐Zechovsky Nicole , Bingen Edouard , Proux Marie‐Christine , Odièvre Michel
Published: January 2024

Quantitative cultures were made of jejunostomy fluid from 22 children with extrahepatic biliary atresia following hepatoportoenterostomy. Bacterial flora characteristics did not differ in patients with or without cholangitis. With the exception of Streptococcus group D, the most frequently encountered bacterial species with the highest mean concentrations in the jejunostomy fluid, were those mostly responsible for cholangitis (Escherichia coli, Klebsiella pneumoniae. and Pseudomonasas aeruginosa). In 19 of 22 acute episodes, the organism causing cholangitis identified in blood and/or liver was also isolated from jejunostomy fluid. However, quantitative determinations in this fluid did not permit reliable identification of this organism. When the same bacterium caused early relapse, it often persisted in the jejunostomy fluid.
An Interactive Microcomputer Program for Calculation of Combined Parenteral and Enteral Nutrition for Neonates
Authors: Gale Rena , Gale J. , Branski D. , Armon Y. , Zelingher J. , Roll D.
Published: January 2024

A responsive, iterating program is described (available on diskette from first author), which enables the physician to formulate a balanced, total parenteral nutrition (TPN) for low‐birth‐weight and sick newborns. The program allows for the possibility of TPN or simultaneous intravenous, intraarterial, and oral feeding. It calculates the overall balance of fluids, nutrients, calories, electrolytes, minerals, trace elements, and vitamins. It features the integration of algorithms and limit tests of nutritional balance, to produce a feeding program that can be modified by clinical considerations of the physician, specific for each patient. The entire procedure can be accomplished, and a record of the entries and orders to the pharmacy and to the ward staff printed, within about 4–5 min. The program, which is written in BASIC, can be accommodated within and operated with a 16K. byte microcomputer, equipped with a monitor, a printer, and a diskette or other program storage device.
Intestinal and Serum Immune Response to a Naturally Acquired Rotavirus Gastroenteritis in Children
Authors: Hjelt Karsten , Grauballe Per C. , Schiotz Peter O. , Andersen Lene , Krasilnikoff Peter A.
Published: January 2024

Seventeen children (mean age: 2.0 years, range: 36 days‐8 years) hospitalized with acute gastroenteritis were investigated. Thirteen children had a rotavirus infection while four did not. Rotavirus serum IgA as well as ScIg, i.e., antirotavirus immunoglobulin containing secretory component, increased rapidly after rotavirus infection. While rotavirus IgA persisted in serum for at least 6 months, rotavirus ScIg disappeared from serum in less than 4 months. Rotavirus IgG could be detected in serum during the early stage of the infection and was still high after 6 months. The patients with nonrota‐virus acute gastroenteritis did not show any of the above‐mentioned serological hallmarks of those with rotavirus infection. The amounts of rotavirus ScIg found in serum about 1 week after the infection correlated to the amounts of rotavirus ScIg in duodenal fluid. Six months after the infection, rotavirus IgA was found in the feces of the majority of the patients while rotavirus ScIg could be detected only in one patient. The amounts of rotavirus IgA in sera and intestinal secretions showed identical patterns in the acute phase of the disease as well as after recovery. The same applied to rotavirus ScIg. These findings could be useful in future evaluations of vaccines and immunity against rotavirus infections.
Superior Mesenteric Artery Syndrome
Authors: Bonamico M. , Roggini M. , Pierro A. , Vici C. Dionisi , Bitti I. Manca
Published: January 2024

The prolonged intestinal retention of a Watson biopsy capsule in a 12‐year‐old girl with chronic diarrhea is reported. Radiological investigation showed a duodenal obstruction due to superior mesenteric artery syndrome. A preliminary barium study of the upper gastrointestinal tract, before performing blind intestinal biopsies, may decrease the incidence of similar complications.
Specific Autoantibodies to Gut Epithelium in Two Infants with Severe Protracted Diarrhoea
Authors: Savage M. O. , Mirakian R. , Wozniak E. R. , Jenkins H. R. , Malone M. , Phillips A. D. , Milla P. J. , Bottazzo G. F. , Harries J. T.
Published: January 2024

Two male infants with severe protracted diarrhoea presenting at 4 months (patient 1) and 10 weeks (patient 2) of age are reported. In both patients jejunal biopsy showed subtotal villous atrophy. Both had specific complement‐fixing autoantibodies reacting by immunofluorescence with human duodenal, jejunal, and colonic epithelium. Patient 1 also had hypothyroidism and type 1 diabetes mellitus with thyroid and islet cell autoantibodies. His gut antibodies were of IgG class, reached a titre of 1:512, and remained positive throughout his illness. He died at 16 months of age. Patient 2 had gut antibodies of IgM class, which reached a titre of 1:128 and disappeared at the time of spontaneous recovery of the diarrhoea. The findings suggest that an autoimmune process was the basis for the enteropathy in these patients. We recommend that autoantibody tests should be performed in infants with unexplained protracted diarrhoea.
Lactose Malabsorption Is Not a Cause of Diarrhea During Phototherapy
Authors: Bujanover Y. , Schwartz G. , Milbauer B. , Peled Y.
Published: January 2024

Lactose malabsorption is not a cause of diarrhea during phototherapy. Jaundiced neonates under phototherapy develop diarrhea or loose stools during the treatment. These phenomena were attributed to an induced lactase deficiency caused by bilirubin breakdown products. We investigated lactose malabsorption in 59 neonates—29 normals and 30 jaundiced under phototherapy. Five‐hour hydrogen breath tests were performed. Preprandial and postprandial (at 30, 60, 120, 180, 240, and 300 min) expired air samples were analyzed for hydrogen. Ten controls and five jaundiced neonates had positive hydrogen breath tests. Eighteen controls and 16 neonates under phototherapy had preprandial hydrogen (concentrations above 5 ppm). In our hands, lactase deficiency and lactose malabsorption were not induced by phototherapy. Lactase deficiency is therefore not the cause of diarrhea associated with phototherapy.
25‐Hydroxyvitamin D Levels During Breast‐Feeding With or Without Maternal or Infantile Supplementation of Vitamin D
Authors: Ala‐Houhala Marja
Published: January 2024

Serum 25‐hydroxyvitamin D (25‐OHD), calcium, phosphorus, magnesium, and alkaline phosphatase levels of breast‐fed infants and their mothers were studied by following 100 healthy term mother‐infant pairs with different supplementation protocols of vitamin D. A pilot study in winter revealed that six of eight breast‐fed infants without vitamin D supplementation had serum 25‐OHD levels below the risk limit for rickets (5 ng/ml) at the age of 8 weeks. In the main study in winter groups, it was found that the 25‐OHD levels were low (5.6 ± 3.7 ng/ml) at the age of 8 weeks in the unsupplemented breast‐fed infants, whose mothers were given vitamin D supplementation of 1,000 IU/day during lactation (group I), compared with the levels of those infants receiving either 400 (18.0 ± 8.4 ng/ml, group II) or 1,000 IU (22.8 ± 11.2 ng/ml, group III) vitamin D (group I vs. group II or III, p < 0.001; group II vs. group III, NS). In group I 10 of 18 infants had serum 25‐OHD levels <5 ng/ml compared with none of the infants in groups II and III. Yet the infants with 25‐OHD levels <5 ng/ml showed no signs of clinical or biochemical rickets at the age of 8 or 20 weeks. In summer at delivery the maternal 25‐OHD levels were good, but decreased thereafter. Also in summer groups, the infantile 25‐OHD concentrations decreased; however, because the levels at delivery were high, they stayed in the normal range. It can be concluded that in a country with scant sunlight in winter, breast feeding alone or with maternal supplementation of 1,000 IU/day vitamin D may lead to very low 25‐OHD levels in the child. A vitamin D supplement of 400 IU/day appears adequate for breast‐fed infants during scarce exposure to sunlight.
Collection of Duodenal Bile in Infants and Children by the String Test
Authors: Rosenthal Philip
Published: January 2024

Present methods for collection of duodenal bile may be difficult to perform and may involve the use of sedation and roentgenograms. The string test (Entero‐Test Pediatric, HDC Corporation, Mountain View, CA) has replaced the need for intestinal intubation for diagnosis of giardiasis and bacterial overgrowth. The present study investigated the use of the string test for collection of duodenal bile. Fifteen children were administered string tests. No complications were encountered. The distal end of the string had yellow pigmented fluid that contained bilirubin conjugates in quantity and quality compatible with duodenal bile. The study demonstrates that the string test is a useful procedure for collection of duodenal bile samples in infants and children.
Effect of Ranitidine on Gastric Acid Hypersecretion in an Infant with Short Bowel Syndrome
Authors: Hyman P. E. , Garvey T. Q. , Harada T.
Published: January 2024

We studied the effect of ranitidine given in graded bolus intravenous doses on gastric acid hypersecretion in an unfed 3‐month‐old male with short bowel syndrome. We measured gastric volume and H+ serially for 12 h following each bolus and correlated inhibition of H+ secretion with plasma ranitidine concentration. In the first 4 h post drug, doses of 0.3, 1.0, 2.0, and 4.0 mg/kg resulted in 78, 93, 97, and 98% inhibition, respectively. The cumulative 12‐h effect of the drug was to inhibit H+ secretion 67, 63, 72, and 87%. The IC50 for H+ secretion was between 50 and 100 ng/ml, and the IC90 between 130 and 150 ng/ml. Volume of gastric secretions was reduced by approximately 50% by all ranitidine doses. Because gastric acid hypersecretion interferes with nutrient absorption, the infant was treated with ranitidine during a 5‐week trial of enteral feeding. A decrease in the antisecretory effect of ranitidine apparent at the end of the treatment period temporally related to an increase in oxyntic mucosal function. No adverse drug effects were observed during treatment.
Severe Giardiasis in a Patient with Cystic Fibrosis
Authors: McCarthy Vincent P. , Nash Theodore E. , Hubbard Van S.
Published: January 2024

A 20‐year‐old male patient with cystic fibrosis (CF) is described, who acutely developed hypoalbuminemia concurrently with giardiasis. Hypoalbuminemia could not be explained by the usual causes seen in patients with CF, but resolved with quinacrine therapy. Subsequently, asymptomatic giardiasis was sought but not found by either the string test or stool exam in any of 15 patients with pancreatic insufficiency who were examined in a prospective manner. Although pancreatic insufficiency is felt to be able to act synergistically with giardiasis to accentuate malabsorption, patients with pancreatic insufficiency per se are not necessarily at greater risk for colonization with Giardia.
Plasma Enteroglucagon in the Control of Childhood Celiac Disease
Authors: Stenhammar Lars , Strömberg Leif , Kilander Anders F. , Lindstedt Göran , Lundberg Per‐Arne
Published: January 2024

To study whether or not plasma enteroglucagon reflects changes of the small intestinal mucosa during different phases of celiac disease, we studied fasting and postprandial concentrations of plasma enteroglucagon, as well as small intestinal mucosa morphology, in children with celiac disease and in a reference group of children without gastrointestinal disorders. The children with celiac disease were studied before dietary treatment, during gluten‐free diet, and during gluten challenge. In untreated celiac children we found high mean basal and postprandial plasma enteroglucagon concentrations compared with the reference group (p < 0.001). After a gluten‐free diet period of 0.2–4.5 years (mean, 1.0 year), when the small intestinal histology was normal or only mildly abnormal, there was a decrease of both mean basal plasma enteroglucagon concentration (from 81 to 17 pmol/L; p < 0.001) and mean postprandial plasma enteroglucagon concentration (from 129 to 39 pmol/L; p < 0.001). During a subsequent gluten challenge, which resulted in a mucosal relapse, there was a rise in mean postprandial plasma enteroglucagon concentration (from 39 to 74 pmol/L; p < 0.005), although there was a substantial overlap in values from treated and challenged patients. These findings suggest that plasma enteroglucagon levels, particularly after a mixed meal, are correlated with the small intestinal mucosal morphology in childhood celiac disease. Determination of plasma enteroglucagon may facilitate the control of the dietary adherence during gluten‐free diet and may in some children indicate mucosal relapse during gluten challenge. Thus, the number of control biopsies may be reduced.
Increased Serum β2‐Microglobulin Levels in Active Celiac Disease
Authors: Blanco A. , Alonso M. , Cilleruelo M. L. , Solis P. , Calvo C. , Villares E. Sanchez
Published: January 2024

Sixty‐eight sera from 36 children with celiac disease (CD) were collected in a 4‐year study, and the levels of β2‐microglobulin (β2M), orosomucoid, α1‐antitrypsin, and C‐reactive protein (CRP) were measured. A simultaneous intestinal biopsy was taken in all the patients and used to classify them. The values of (β2M were 1.94 ± 0.49 mg/L in group A (inactive CD with normal intestinal biopsy) and 2.58 ± 0.76 mg/L in group B (active CD with flat mucosa). These levels were higher than in the normal controls (1.87 ± 0.49 mg/L, p < 0.005) and in the other 19 patients with chronic diarrhea of another cause (1.72 ± 0.63 mg/L, p < 0.005). CRP values were generally normal; orosomucoid and α‐antitrypsin were variable and they did not correlate with β2M levels. β2M was increased at the time of diagnosis in seven of eight (87.5%) of the CD children and only in three of 19 (15.7%) of nonceliac patients with chronic diarrhea of another cause (p < 0.005). In 12 children with CD, serial studies were possible. The highest β2M level coincided with a flat mucosa in 10 cases. The increase of β2M could be related to the intestinal infiltration or even to the lymphocyte activation. It may also be a useful noninvasive method for evaluating the activity of CD.
Permeability of the Small Intestine to [51Cr]EDTA in Children with Acute Gastroenteritis or Eczema
Authors: Forget Philippe , Sodoyez‐Goffaux Franchise , Zappitelli A.
Published: January 2024

Increased gut permeability to macromolecules is thought to be an important factor in the development of food hypersensitivity. The latter can develop in the course of acute gastroenteritis and could play a role in infantile eczema. We studied gut permeability in 10 normal adults, 11 control children, 7 children with acute gastroenteritis, and 8 patients with infantile eczema, making use of [51Cr]EDTA as probe molecule. [51Cr]EDTA was given orally (50–100 (μC1); 24‐h urinary excretion of [5ICr]EDTA was measured and expressed as a percentage of the oral dose. Mean and standard error were 2.35 ± 0.24, 2.51 ± 0.21, 9.96 ± 3.44, and 10.90 ± 2.05 in normal adults, control children, and gastroenteritis and eczema patients, respectively. Differences between controls and either gastroenteritis (p < 0.001) or eczema (p < 0.001) patients are significant. Our results support the hypothesis that increased gut permeability could play a role in food hypersensitivity.
Habit Training as Treatment of Encopresis Secondary to Chronic Constipation
Authors: Lowery Susan P. , Srour James W. , Whitehead William E. , Schuster Marvin M.
Published: January 2024

Fifty‐eight encopretic children were placed on a habit training regimen consisting of initial disimpaction followed by attempts to defecate after a specific meal, and use of enemas contingent on failure to defecate for 2 successive days. All patients had gross incontinence of long duration. After an average of less than four visits in 5 months, 83% had an excellent outcome, 60% were completely continent, and 23% had only staining. Patients not achieving continence averaged a 90% decrease in frequency of incontinence. The mean frequency of incontinent episodes decreased from 13.2 to 0.52 per week, while appropriate bowel movements increased from 3.8 to 5.9 per week. At follow‐up (average of 3 years), 61% of 43 patients contacted had excellent outcomes, 51% were continent, and 10% had only staining. Patients still incontinent at follow‐up averaged 89% fewer episodes than they had prior to treatment. These findings show habit training to be a rapidly effective and long‐lasting treatment for encopresis secondary to chronic constipation.
Free Fatty Acids in the Development of Breast Milk Jaundice
Authors: Jalili Firooz , Garza Cutberto , Huang Charles T. L. , Nichols Buford L.
Published: January 2024

The incubation of milk, at 40C, from mothers of infants with breast milk jaundice (BMJ) is reported to result in significantly higher levels of free fatty acids (FFA; compared with milk from controls. Single milk samples collected under standard conditions were obtained from four mothers of infants with BMJ and 14 control donors matched for stage of lactation. Milk samples were analyzed for the concentrations of FFA, using thin‐layer gas chromatographic techniques. In addition, serum total fatty acids were measured in mothers and infants. The concentrations of FFA increased after storage of the milk from both the jaundiced and control groups. No differences were observed in the composition of milk FFA before or after incubation, when respective values were compared between these two groups. Similarly, no differences were detected in serum total fatty acids in either infants or mothers. The observation that increased levels of FFA in milk are associated with BMJ was not confirmed.
Intralipid Infusion in Neonates
Authors: Wheeler J. Gary , Boyle Robert J. , Abramson Jon S.
Published: January 2024

In vivo and in vitro studies were done to assess the effects of Intralipid (IL) on neonatal polymorphonuclear leukocyte (PMNL) function. No significant abnormalities of chemotactic (CT) or chemiluminescent (CL) activities were noted in cord or adult PMNLs incubated with IL (10 mg/ml) when compared with paired controls incubated with buffer. In 14 premature and term neonates, IL was infused at 1 g/kg/24 h. Postinfusion CL activity of PMNLs was not significantly different from preinfusion CL activity. Although previous animal and human studies have shown abnormalities of PMNL function using higher infusion rates, slow infusion of IL at 1 g/kg/24 h produced no detectable alteration in PMNL oxidative function. The safety of long‐term therapy with higher doses of IL remains to be proven.
Elevated Serum γ‐Aminobutyric Acid Levels in Children with Reye's Syndrome
Authors: Minuk G. Y. , Sarjeant E. J. , Buchan K.
Published: January 2024

Elevated serum levels of γ‐aminobutyric acid (GABA), a potent inhibitory neurotransmitter, have recently been implicated in the pathogenesis of hepatic encephalopathy. In this study, serum GABA levels were measured in five children with severe Reye's syndrome, 10 children with acute viral hepatitis, and seven healthy volunteers. Serum GABA levels were highest in the five Reye's syndrome patients. The mean serum GABA level for the Reye's syndrome group (3.0 ± 1.3 üM, mean ± SEM) was significantly elevated as compared to the mean of the viral hepatitis group (0.72 ± 0.07 μM, p < 0.05) and the healthy volunteers (0.38 ± 0.04 μM, p < 0.05). These results provide preliminary evidence to suggest that elevated serum GABA levels may in part be responsible for the encephalopathic state observed in children with Reye's syndrome.
Differential Effect of Botulinal Toxin on Esophageal Motor Function in Infants
Authors: Cannon Robert A.
Published: January 2024

The effect of Clostridium botulinum toxin on esophageal motor function was studied in four infants (ages 5–9 months) with confirmed infant botulism. Esophageal motility studies using a perfused catheter assembly were performed during the acute phase in all patients, and during the recovery phase in one patient. Motor function of the proximal esophagus and upper esophageal sphincter was abnormal in each, while motor function of the distal esophagus and lower esophageal sphincter was normal. Mean lower esophageal sphincter pressure was 24 mm Hg for the group (normal: 15–30 mm Hg). Sequential studies of proximal esophageal motility in one infant revealed a return of normal motor function which correlated with recovery of peripheral muscle strength and gag reflexes. C. botulinum toxin impairs proximal, but not distal, esophageal motor function in the infant botulism model. This effect appears to be consistent with the known action of the toxin on synaptic acetylcholine release and current concepts regarding distribution of cholinergic and noncholinergic neurotransmitter receptors in the esophagus.
Total Parenteral Nutrition
Authors: Zahavi I. , Shaffer E. A. , Gall D. G.
Published: January 2024

To assess the basis of cholestasis associated with total parenteral nutrition (TPN), we studied the short term effect of the component solutions on bile flow and bile salt secretion in infant and adult rabbits. Groups of four to six adult and infant rabbits received intravenously 154 mM NaCl (control), 2.5% amino acid, 10% glucose, or 10% fat emulsion alone or in combination. Bile was collected directly from the common bile duct for 3 h. Solutions containing both amino acids and glucose significantly (p < 0.05) reduced bile flow and bile salt secretion in both age groups. Glucose alone also decreased bile flow and bile salt secretion, whereas amino acids as the sole infusate significantly (p < 0.05) decreased bile flow only. The suppressive effect of the amino acid glucose solutions on bile flow was more pronounced in infants than in adults. Fat emulsion alone had no effect on bile formation. Our findings demonstrate that short term intravenous administration of nutrient solutions containing amino acids and glucose reduces bile flow and bile salt secretion, suggesting that these components are responsible for TPN associated cholestasis.
Precocious Increase of Sucrase Activity by Carbohydrates in the Small Intestine of Suckling Rats. II. Role of Digestibility of Sugars, Osmolality, and Stomach Evacuation in Producing Diarrhea
Authors: Goda T. , Bustamante S. , Edmond J. , Grimes J. , Koldovsky O.
Published: January 2024

The mechanisms of carbohydrate induced diarrhea in suckling rats were investigated with respect to osmolality and type of sugar in the milk. Groups of 12 day old rats were gavage fed either a basic low carbohydrate milk formula [10.8% fat; 8% protein; 1.4% carbohydrate (weight/volume)] or basic formula with added sucrose, fructose, lactose, or glucose polymers, all as 13% (weight/ volume). All formulas were isocaloric. Their corresponding osmolalities were 278, 645, 1,130, 617, and 349 mOsmol/ kg, respectively. Gastric evacuation of water soluble materials from formulas containing sucrose, fructose, or glucose polymers was significantly slower than the gastric evacuation of the basic formula and the formula that contained lactose. The net fluid absorption from the small intestine was significantly greater from the basic and lactose containing formulas when compared with sucrose, fructose, or glucose polymer containing formulas. When the synthetic milk formulas were placed directly into the isolated noileum in vivo, the formulas of higher osmolality (fructose, sucrose, and lactose) caused water flux into the intestine at 60 min, while digestion of the lactose formula reversed the water flux within 120 min. We conclude that the type of added sugar is a decisive factor in gastric evacuation, and that water flux into and out of the intestine is significantly affected by the osmolality and rate of digestion and absorption of the carbohydrate in the formula; these differences among sugars may play a significant role in the etiology of diarrhea.
Life
Authors: Maggiore G. , Bernard O. , Hadchouel M. , Alagille D.
Published: January 2024

A 13 year old girl with a 1 year history of elevated serum alanine transferase was hospitalized because of liver failure. Low prothrombin time (12%) prevented needle liver biopsy. Because of a high titer of antismooth muscle antibodies (1:500), a tentative diagnosis of “autoimmune” chronic active hepatitis was made and immunosuppressive therapy was started. Despite the severity of the liver disease, of her poor general condition, and of spontaneous bacterial peritonitis, she dramatically responded to treatment, prothrombin time returning to normal within 5 months. Diagnosis of chronic active hepatitis was later confirmed by liver biopsy. This report indicates that immunosuppressive therapy can be life saving in children with severe chronic active hepatitis even when major signs of liver failure are present.
[13C]Acetate Oxidation in Infants After Oral Versus Rectal Administration
Authors: Lifschitz Carlos H. , Irving Charles S. , Helge Hans , Wong William W. , Boutton Thomas W. , Nichols Buford L. , Klein Peter D.
Published: January 2024

Summary:

To study the fate of volatile fatty acids (VFA) in the large bowel, we compared the rate of oxidation of 13C‐labeled VFA administered rectally with that of the orally administered substrate. On two different days, 1‐[13C]acetate was administered rectally or orally to five infants recovering from diarrhea. Breath samples were collected over 4 h and analyzed for 13C enrichment of breath CO2 by gas isotope ratio mass spectrometry. The percent dose recoveries of 13C in breath were fitted to multicom‐partmental models using the SAAM‐27 program. Following model development procedures, the oral acetate breath test curves could be accounted for only by a compartmental model in which labeled acetate underwent absorption into and mixed with a systemic pool before oxidation took place. The rectal acetate breath test curves could be accounted for by a simpler model in which oxidation occurred directly in the compartment in which the rectal acetate was administered, and required no rate‐limiting absorptive process. Our results indicate that the labeled acetate was oxidized more rapidly when the substrate was administered rectally than orally. This observation points to the direct utilization of volatile fatty acids within the colon.
Gliadin‐Specific Serum Immunoglobulins A, E, G, and M in Childhood
Authors: Juto Per , Fredrikzon Bo , Hernell Olle
Published: January 2024

Summary:An enzyme‐linked immunosorbent assay technique was developed to determine serum antigliadin antibodies of the IgA, IgE, IgG, and IgM classes. The antibody level of each serum specimen was expressed as an index value, i.e., optical density of test serum/optical density of cutoff, where cutoff was calculated for each immunoglobulin class as the mean + 3 SD for six healthy controls. Indices for each immunoglobulin class were determined in 69 children who were admitted for their first small intestinal mucosal biopsy due to either symptoms of malabsorption compatible with celiac disease, or short stature without other symptoms. Especially raised levels of antigliadin IgA antibodies in serum correlated strongly with villous atrophy and in infants ≤3 years of age were invariably elevated above controls, provided they were on a gluten‐containing diet. Raised levels of IgG and IgE antibodies to gluten were often seen in children with normal mucosal morphology, i.e., when symptoms were due to other gastrointestinal disorders than celiac disease. It is concluded that determination of antigliadin IgA antibodies in children ≤3 years is a useful screening test before small intestinal biopsy, especially in children where the indication for biopsy is not otherwise obvious. The method can also be used to assess the results of therapy and, conceivably, compliance.