Comparison of Blue and Infrared Light Transmission Through Dental Tissues and Restorative Materials.

OBJECTIVES: The depth of cure using blue-light photocuring units (BL) is limited by tooth structure and qualities of the restorative material through which the activating wavelength must pass. Recent developments incorporate an infrared (IR) activated upconversion (UC) fluorescence of a lining agent filled with nanocrystals of NaYF4 and doped with YB+3 and Tm+3 that emit both blue and violet light locally at the interface of the liner and restorative resin. The purpose of this study was to evaluate the BL and 975 nm infrared (IR) light power transmission through dental tissues and restorative materials. METHODS AND MATERIALS: Power transmissions of the IR laser (975 nm) and a monowave blue-only light-curing unit (Bluephase 16i) through dental tissues (enamel, dentin, and enamel/dentin junction, or DEJ), eight (8) various dental resin composites, and eight (8) dental ceramics, each at four thicknesses (1, 2, 3 and 4 mm) were evaluated (n=5) using a thermopile sensor (PM10, Coherent Inc) connected to a laser power meter (Fieldmate, Coherent Inc). Power transmission values of each light source and restorative material were subjected to analysis of variance and Tukey test at a pre-set alpha of 0.05. RESULTS: A linear correlation (r=0.9884) between the supplied current and emitted IR power of the laser diode was found, showing no statistical power reduction with increased distances (collimated beam). For tooth tissues, the highest power transmissions for both light sources were observed using 1.0 mm enamel while the lowest values were found for 2.0 mm dentin and an association of 2.0 mm DEJ and 1.0 mm dentin. The only group where IR demonstrated significantly higher transmission when compared to BL was 1.0 mm enamel. For all resin composites and dental ceramics, increased thickness resulted in a reduction of IR power transmission (except for EverX Posterior fiber-reinforced composite and e.max HT ceramic). IR resulted in higher transmission through all resin composites, except for Tetric EvoCeram White. The highest BL transmission was observed for SDR Flow, at all thicknesses. Higher IR/BL ratios were observed for EverX Posterior, Herculite Ultra, and Lava Ultimate, while the lowest ratio was observed for Tetric EvoCeram White. Reduced translucency shades within the same material resulted in lower power ratio values, especially for BL transmission. Higher IR/BL ratios were observed for e.Max LT, VitaVM7 Base Dentin, and e.max CAD HT, while the lowest values were found for VitaVM7 Enamel and Paradigm C. CONCLUSION: IR power transmission through enamel was higher when compared to blue light, while no difference was observed for dentin. The power transmission of IR was higher than BL for resin composites, except for a high value and low chroma shade. Fiber-reinforced resin composite demonstrated the highest IR/BL power transmission ratio. A greater IR/BL ratio was observed for lower translucency ceramics when compared to high translucency.

Spin-electron-phonon excitation in Re-based half-metallic double perovskites.

A remarkable hardening (~30 cm(-1)) of the normal mode of vibration associated with the symmetric stretching of the oxygen octahedra for the Ba(2)FeReO(6) and Sr(2)CrReO(6) double perovskites is observed below the corresponding magnetic ordering temperatures. The very large magnitude of this effect and its absence for the antisymmetric stretching mode provide evidence against a conventional spin-phonon coupling mechanism. Our observations are consistent with a collective excitation formed by the combination of the vibrational mode with oscillations of Fe or Cr 3d and Re 5d occupations and spin magnitudes.

Temperature-dependent Raman scattering of multiferroic Pb(Fe(1/2)Nb(1/2))O3.

Raman scattering measurements on multiferroic Pb(Fe(1/2)Nb(1/2))O3 over a wide temperature range from 10 to 500 K were performed. Very broad and overlapping peaks (first-order character) and a prominent high-frequency peak at approximately 1130 cm( - 1), which we assign as a two-phonon peak, were observed. These features showed remarkable changes in their Raman scattering intensity and spectral shape at the characteristic temperature T(*) ∼ 330 K, clearly showing a structural lattice change at around T(*). The temperature dependence of some stretching vibration modes of the BO(6) units revealed an anomalous frequency shift below T(N) approxiamtely 143 K. These anomalous deviations at T(N) of the phonon frequency are associated with the spin-phonon coupling mechanism. Complementary magnetic data confirmed a weak magnetic ordering at room temperature and interestingly showed an anomaly at about T(*). These results suggest an interplay between ferroelectric, structural and magnetic degrees of freedom in PFN, starting to be significant at around T(*).

Ileal manometry in children following ileostomies and pull-through operations.

Our aim was to analyse the patterns of ileal contractions in children. We reviewed the charts of 23 children who had ileal manometry studies (16 males), mean age 7 years (range 2 months to 17 years). We positioned the manometry catheters with 4-8 recording sites, 5 or 15 cm apart, through ileostomies fashioned for clinically indicated reasons. We studied six additional children with persistent faecal soiling following endorectal pull through for Hirschsprung's disease; the catheters were positioned through the anus and colon into the ileum. We recorded phasic and tonic intermittent contractions in all the subjects, clustered contractions (rate 5-9 min-1, duration 20-120 s) in 19 subjects with ileostomies and four with endorectal pull throughs. In 13 children there were prolonged propagated contractions, > 60 mmHg in amplitude, > 15 s in duration, propagating at rates of 2-6 cm s-1 over at least 20 cm. The migrating motor complex was rare; in 55 h of fasting recording there were two phase III sequences. There are four distinctive features of ileal manometry recordings in children: random intermittent contractions, clustered contractions, prolonged propagated contractions and tonic contractions. The features of ileal motility differ from motility in the proximal small bowel.

Function of hollow viscera in children with constipation and voiding difficulties.

We wished to investigate the urodynamic characteristics and colonic motility in a group of children with severe chronic constipation and lower urinary tract symptoms. We performed colonic manometry using an endoscopically placed catheter. The urodynamic studies consisted of cystometry, electromyography of the external urethral sphincter, measurement of urinary flow rate, and urethral pressure profile. We found abnormal colonic motility in all patients. Findings included: absent gastrocolonic response (N = 8), absent high-amplitude propagated contractions (HAPCs) (N = 4), and abnormal propagation of HAPCs (N = 7). Urodynamic features were abnormal in 10 children. Findings included: uninhibited bladder contractions (N = 6), hypertonic bladder (N = 2), sphincter dyssynergy (N = 2), small capacity bladder (N = 1). In all children constipation improved, in three after a partial colectomy. Urinary symptoms persisted. We conclude that some children with severe constipation may have a neuropathy affecting both the colonic and lower urinary tracts systems. In this group of patients treatment of constipation does not result in resolution of urinary symptoms.

Colonic motility after surgery for Hirschsprung's disease.

OBJECTIVE: Years after surgery for Hirschsprung's disease, many children continue to suffer from fecal incontinence or constipation. The purpose of the present investigation was to define the physiology underlying the persistent symptoms in children after surgery for Hirschsprung's disease, and to determine the outcome of interventions based on the results of the motility testing. METHODS: We studied 46 symptomatic patients (5.5+/-3.3 yr old, 35 male) >10 months after surgery for Hirschsprung's disease. We performed a colonic manometry with a catheter placed with the tip in the proximal colon. We used a structured questionnaire and phone interview to follow up the patients an average of 34 months after the manometry. RESULTS: We identified four motility patterns: 1) high-amplitude propagating contractions (HAPCs) migrating through the neorectum to the anal sphincter, associated with fecal soiling (n = 18); 2) normal colonic manometry associated with fear of defecation and retentive posturing (n = 9); 3) absence of HAPCs or persistent simultaneous contractions over two or more recording sites (n = 15), associated with constipation (n = 13); and 4) normal colonic motility and a hypertensive internal anal sphincter (>80 mm Hg) (n = 4). We based treatment on results of the motility studies. There was improvement in global health (mean score, 3.9+/-1.1 vs 2.8+/-1.3 at the time of initial evaluation, p < 0.001) and emotional health (3.8+/-1.1 vs 2.6+/-1.1, p < 0.0001). Improvement in the number of bowel movements occurred in 72% of children. Resolution or decreased abdominal pain was reported in 80%. CONCLUSIONS: Colonic manometry clarifies the pathophysiology and directs treatment in symptomatic children after surgery for Hirschsprung's disease.

Colonic motility in children with repaired imperforate anus.

Following surgical correction of imperforate anus, voluntary bowel control is frequently poor because of abnormal anorectal function. Using colonic manometry we investigated the role of colonic motility in the pathogenesis of fecal soiling in children following imperforate anus repair. Thirteen children with repaired imperforate anus and fecal soiling underwent motility testing 2-12 years after anoplasty. All had fecal incontinence unresponsive to conventional medical treatment. Colonic manometry was performed using water-perfused catheters. Anorectal manometry was undertaken in 10 patients. Motility study results, treatment and outcomes were compared. All patients had high-amplitude propagating contractions (HAPCs) with an average of 80% propagation into the neorectum. There was no correlation between HAPC number or morphology and any variable. Internal anal sphincter resting pressure was low in 6/10 patients. Relaxation of the internal anal sphincter was present in 6/10 children. Only 1 of 5 patients able to cooperate was capable of generating a normal maximal squeeze pressure. Therapeutic regimens were changed in 11 patients with clinical improvement in five. Fecal soiling in patients with repaired imperforate anus is a multifactorial problem including propagation of excessive numbers of HAPCs into the neorectum as well as internal anal sphincter dysfunction. Colonic manometry in conjunction with anorectal manometry aids in the understanding of the pathophysiology of fecal soiling and guides clinical management in children with repaired imperforate anus.

Effect of sequential erythromycin and octreotide on antroduodenal manometry.

BACKGROUND: In earlier studies, erythromycin stimulated but octreotide inhibited gastric antral contractions, as each drug induced phase 3-like episodes. METHODS: To assess the effect of erythromycin pretreatment on octreotide-induced changes in antroduodenal motility, 16 patients were studied (mean age, 8.7 +/- 1.5 years, 8 male): 6 with severe gastroesophageal reflux, 4 with cyclic vomiting, 3 with gastroparesis, 2 with chronic intestinal pseudo-obstruction, and 1 with Crohn's disease and unexplained nausea and vomiting. After recording fasting antroduodenal motility for 3 hours, 1 mg/kg intravenous erythromycin was administered over 30 minutes. Sixty minutes after the erythromycin infusion, 0.5 microg/kg subcutaneous octreotide was administered, followed 1 hour later by a meal. RESULTS: Phase 3 occurred spontaneously in 10 patients and after erythromycin in 12 patients. When administered after erythromycin, octreotide immediately induced phase 3s contractions in 15 patients, beginning in the antrum. In 7 children, some of the octreotide-induced phase 3s did not propagate. After the meal, antral contractions continued in all patients. The fed pattern was replaced in 14 patients by alternating phase 3 and phase 1 activities. CONCLUSIONS: Pretreatment with erythromycin prevented octreotide-induced inhibition of antral contractions. Inhibition of antral contractions by octreotide may be mediated through either a direct or indirect suppression of motilin release, because antral contractions persist after pretreatment with the motilin receptor agonist erythromycin.

Effect of octreotide on gastrointestinal motility in children with functional gastrointestinal symptoms.

BACKGROUND: The somatostatin analogue octreotide has been proposed as a possible therapeutic agent in patients with abnormal gastrointestinal motility. This study was conducted to study the effects of 0.5 microg/kg and 1.0 microg/kg subcutaneous octreotide on antroduodenal motility in children with chronic gastrointestinal disorders. METHODS: Twenty-three children were studied, eight with intestinal pseudo-obstruction, six with nonulcer dyspepsia, six with gastroesophageal reflux disease, and three with intractable constipation. After recording fasting motility for more than 4 hours, the children were randomized to receive 0.5 microg/kg or 1 microg/kg of subcutaneous octreotide. Motility was recorded for another hour after feeding in 12 children. RESULTS: Phase III of the motor migrating complex was present in 13 of 23 children before and in 21 after octreotide (p < 0.02). All phase III episodes after administration of octreotide except one originated in the small intestine. Phase IIIs after octreotide were longer and were propagated faster than the spontaneous phase IIIs. There were no antral contractions during fasting after octreotide. There was a significant decrease in phase II intestinal motor activity in the hour after administration of octreotide (p < 0.001). There was no difference in effect between the two doses. After feeding, antral contractions were present in all children, and intestinal phase IIIs were not abolished. CONCLUSIONS: In children with chronic bowel disorders, subcutaneous octreotide induced phase IIIs that differed from spontaneous phase IIIs and were not inhibited by meals. Octreotide decreased antral motility during fasting and inhibited intestinal phase II. Feeding abolished the inhibitory effect of octreotide on antral motility.

Bisacodyl and high-amplitude-propagating colonic contractions in children.

BACKGROUND: The purpose of these studies was to determine the suitability of bisacodyl for stimulating high-amplitude-propagating contractions in pediatric studies of colonic manometry. METHODS: Water-perfused manometry catheters were inserted into the right colon of children referred for evaluations related to defecation disorders. Colonic motility was measured in a 3-hour test session: an hour fasting, an hour after a meal, and 30 minutes after administration of a provocative agent. RESULTS: Bisacodyl was superior to edrophonium as a stimulant for inducing high-amplitude-propagating contractions. Bisacodyl-induced high-amplitude-propagating contractions were similar in amplitude, duration, propagation velocity, and sites of origin and extinction to naturally occurring high-amplitude-propagating contractions. The effect of intrarectal bisacodyl was similar to that of intracecal bisacodyl, except for a delay of 10 minutes in onset. Bisacodyl induced high-amplitude-propagating contractions in all 28 children (22 with spontaneous high-amplitude-propagating contractions) without evidence of neuromuscular disease and in 2 of 9 children with a colonic neuromuscular disorder and no spontaneous high-amplitude-propagating contractions. CONCLUSIONS: Bisacodyl-induced high-amplitude-propagating contractions were quantitatively and qualitatively similar to naturally occurring high-amplitude-propagating contractions. In selected cases, such as in children receiving total parenteral nutrition or restricted fluid intake, it may be possible to shorten diagnostic colonic manometry using bisacodyl rather than waiting for spontaneous high-amplitude-propagating contractions.

Is electrogastrography a substitute for manometric studies in children with functional gastrointestinal disorders?

We performed simultaneous fasting and fed antroduodenal manometry and EGG in 25 children with functional bowel disorders. Three patients (12%) had an uninterpretable EGG. The manometric studies showed severe neuropathy in six patients; milder neuropathic changes in five patients; postprandial hypomotility in one patient; myopathy in four patients, and normal motility in the remaining six patients. The percentage of tachygastria time (frequency > 3.5 cycles/min) was higher in the patiens with mild (44.1 +/- 15.8%) and severe (48 +/- 19.1%) neuropathy than in the patients with myopathy (20 +/- 16.2%, P < 0.05) or with normal motility (23 +/- 13.3%, P < 0.05). There was a considerable overlap in the percentage of tachygastria and total arrhythmia time among the different study groups. The ratio of post- to preprandial power was significantly higher (2.5 +/- 0.07) in children with normal motility than in the other patients groups. Every child with total arrhythmia time < 35% and a ratio of post- to preprandial power > 2.4 had normal manometry. In summary, EGG differentiated groups of children with normal manometry from others with neuropathic or myopathic changes, but in a minority of patients the study was not interpretable and there was overlap in EGG results between children with normal and abnormal manometry.

Immune deficiencies in chronic intestinal pseudo-obstruction.

AIM: Chronic intestinal pseudo-obstruction has been associated with urinary disorders, myopathy, and ophthalmoplegia in adults and cholelithiasis in children. We observed a high percentage of total-parenteral-nutrition-dependent patients with pseudo-obstruction and recurrent infections requiring gammaglobulin infusions. METHODS: All records for 23 children with chronic intestinal pseudo-obstruction (10 females and 13 males, mean age 9.8 y +/- 4.9 y, range 4-24 y) referred for a nutritional evaluation from 1992 to 1995 were reviewed. Chronic intestinal pseudo-obstruction was diagnosed by clinical, radiographic findings and antroduodenal manometry. Intestinal full-thickness biopsies were performed in seven children. RESULTS: Hypogammaglobulinemia was diagnosed in 18 patients (78%): 16 patients had various immunoglobulin deficiencies and 2 had selective antibody deficiency. Intravenous gammaglobulin was administered in 14 patients. Other medical conditions affecting the children are summarized as follows: autonomic dysfunction in 10 patients (43%), recurrent hypoglycemia in 9 (39%), asthma in 9 (39%), cholecystitis in 7 (30%), low serum carnitine level in 6 (26%), urinary dysfunction in 6 (26%), pancreatitis in 5 (22%), behavioral problems in 5 (22%), myopathy in 2 (9%), idiopathic thrombocytopenia in 2 (8%), velopharyngeal insufficiency in 1 (4%), oculocutaneous albinism in 1 (4%), Pierre-Robin syndrome in 1 (4%), and protein C deficiency in 1 (4%). Munchausen syndrome was suspected in two patients. CONCLUSIONS: Chronic intestinal pseudo-obstruction appears to be associated with immune deficiencies. It is unclear if the immune deficiencies, intestinal pseudo-obstruction, and the other medical conditions have a common underlying etiology. Repeated infections may be due to impaired immune function in children with chronic intestinal pseudo-obstruction. We recommend screening for immune deficiencies in children with chronic intestinal pseudo-obstruction.

Chronic intestinal pseudoobstruction associated with fetal alcohol syndrome.

Alcohol acts as a teratogen in the fetus, resulting in prenatal or postnatal growth failure, characteristic facial dysmorphic features, and central nervous system dysfunction. The toxic effects of alcohol on the developing brain are well recognized, but gastrointestinal neuropathy has not been described in fetal alcohol syndrome (FAS). Five children with FAS presented in infancy with signs and symptoms suggestive of chronic intestinal pseudoobstruction. They were not able to sustain adequate caloric intake by mouth, and all required prolonged special methods of alimentation. We performed antroduodenal manometry in these children to determine whether their symptoms were associated with a gastrointestinal motility disorder. All patients had abnormally propagating phase III-like episodes during fasting (retrograde in four, simultaneous in two). Persistent clusters of stationary contractions were a prominent feature in two patients. In utero neurotoxicity of alcohol may not be limited to the central nervous system, but may also cause an enteric neuropathy presenting in infancy as chronic intestinal pseudoobstruction.

Age-related changes in colon motility.

To assess age-related changes, we analyzed 32 colon manometry studies of children referred for motility studies and found not to have colonic disease. Colon motility was recorded by endoscopically placed water-perfused catheters. There was an inverse correlation between the number of high-amplitude propagated contractions and age, before and after administration of a meal; colonic contractions different from the high-amplitude propagated contractions increased with age.

Intestinal motility and jejunal feeding in children with chronic intestinal pseudo-obstruction.

BACKGROUND/AIMS: Total parenteral nutrition is responsible for most of the morbidity and mortality of childhood chronic intestinal pseudo-obstruction (CIP). The aim of this study was to determine if there are manometric patterns associated with the success of jejunal feedings in children with CIP. METHODS: Eighteen children with CIP (age range, 1-9 years; mean, 4 years; 11 boys and 7 girls) were studied. All patients required parenteral nutrition or failed to thrive while receiving gastrostomy feedings. All underwent an antroduodenal manometry before surgical placement of a jejunostomy. Continuous drip jejunal feeding with an elemental formula was subsequently initiated. Follow-up after jejunal feeding was 1.6 years (range, 6 months to 4 years). Jejunal manometry was performed 2 months to 1 year after jejunostomy. RESULTS: Jejunal feeding eliminated the need for parenteral nutrition in all 9 patients with migrating motor complex (MMC) and in 3 of 9 patients without MMC (P < 0.01). The MMC was present or absent in both antroduodenal and jejunal manometry in 14 of 18 children (77.7%). In 10 of 18 children (55%), duodenal and jejunal manometry showed similar qualitative abnormalities. CONCLUSIONS: In selected children with CIP who fail gastrostomy feeding, jejunal tube feeding is an alternative to parenteral nutrition. The presence of MMCs is associated with a successful adaptation to jejunal feeding.

Antroduodenal manometry in children and adults with severe non-ulcer dyspepsia.

BACKGROUND: Nonulcer dyspepsia is common in adults but has been recognized only recently in children. METHODS: We compared signs, symptoms, and antroduodenal motility findings in 34 children and 35 adults with severe nonulcer dyspepsia. RESULTS: Symptoms and signs were similar in the two groups. Ten children (29%) and one adult (3%) required tube feedings (p = 0.01). Abdominal surgery had been performed on 6 of 34 (18%) children and 18 of 35 adults (51%) (p < 0.01), without relief of symptoms. Esophageal manometry was abnormal in 5 of 23 (22%) children and 6 of 31 (19%) adults. Antroduodenal manometry was suggestive of neuropathy in 25 children and 26 adults and of myopathy in 3 children and 2 adults. Absence of phase 3 of the migrating motor complex was found in 4 children and 17 adults (p = 0.01). Antroduodenal manometry was normal in six children and seven adults. CONCLUSION: Signs, symptoms, and discrete manometric abnormalities of childhood nonulcer dyspepsia resembled those of adult nonulcer dyspepsia. Manometric findings in nonulcer dyspepsia resembled those reported in chronic intestinal pseudo-obstruction, suggesting that these conditions are on a continuum of enteric neuromuscular diseases.

Effect of erythromycin on antroduodenal motility in children with chronic functional gastrointestinal symptoms.

To evaluate the effects of erythromycin on antroduodenal motility in children with chronic functional gastrointestinal symptoms, we studied 35 consecutive subjects referred for diagnostic motility studies. We recorded fasting motility for > 4 hr, then infused in random order either 1 or 3 mg/kg erythromycin intravenously over 1 hr and continued the study for another hour. Erythromycin induced phase III in 18 of 20 children who had phase III during fasting compared to only one of 15 who did not (P < 0.001). The antral motility index increased after erythromycin (1596 +/- 323 vs 436 +/- 242 mm Hg/30 min before erythromycin, P < 0.005) but the duodenal motility index did not change. The antral motility index was greater in children receiving 3 mg/kg than in those receiving 1 mg/kg (1968 +/- 391 vs 1226 +/- 285 mm Hg/30 min, P < 0.01), but duodenal motility indices did not differ. Only one child receiving the lower dose erythromycin complained of abdominal pain, nausea, or vomiting vs 9 of 19 the children receiving the higher dose (P < 0.02). In summary, in children with chronic functional gastrointestinal disorders, erythromycin rarely induced phase III in patients who did not have it during fasting. When different doses erythromycin are compared, 1 and 3 mg/kg are equally efficacious in inducing phase III episodes; the lower dose is associated with fewer side effects and the higher dose produces a higher antral motility index.

Predicting the clinical response to cisapride in children with chronic intestinal pseudo-obstruction.

We assessed upper gastrointestinal anatomy and function with contrast radiology and antroduodenal manometry in 51 children with chronic intestinal pseudo-obstruction (CIP) prior to entering these patients into an open-label outpatient trial of cisapride. The diagnosis of CIP was based on characteristic symptoms requiring special nutritional support (parenteral in 30, tube feeding in 12) or interfering with daily activities (documented by diary in nine). At a time the subjects were not acutely ill, antroduodenal pressures were recorded for > 4 h fasting and > 1 h after a complex liquid meal. Results were categorized by the most prominent manometric abnormality as myopathy (n = 6), absent migrating motor complex (MMC) (n = 27), failure to induce fed pattern (n = 7), MMC plus discrete abnormalities (n = 7), and postprandial duodenal hypomotility (n = 4). Patients in the first two categories did not have effective MMCs, but those in the last three categories did. Compared to children without MMCs, those with MMCs rarely required parenteral nutrition (p < 0.001). All children were treated with oral cisapride 0.2 mg/kg/dose t.i.d., and evaluated every 2 months for up to 1 yr. Of 49 evaluable subjects, the final global assessment was unchanged in 25, fair (improved symptom score) in 17, or excellent (change from TPN to tube feeding or tube feeding to oral feeding) in seven. Children with MMCs (13 of 18) responded more often to cisapride than those without MMCs (11 of 31), p < 0.02. All four subjects with postprandial duodenal hypomotility had excellent responses. Children with normal diameter bowel responded more often than those with dilated bowel, p < 0.004. To summarize, in children with CIP, absence of the MMC was associated with need for greater intensity of nutritional support and decreased response rate to cisapride. The response to cisapride was highly variable within the study group, but often could be predicted by the presence or absence of bowel dilation and MMCs.