Demonstration of a state-insensitive, compensated nanofiber trap.

We report the experimental realization of an optical trap that localizes single Cs atoms ≃215 nm from the surface of a dielectric nanofiber. By operating at magic wavelengths for pairs of counterpropagating red- and blue-detuned trapping beams, differential scalar light shifts are eliminated, and vector shifts are suppressed by ≈250. We thereby measure an absorption linewidth Γ/2π=5.7±0.1 MHz for the Cs 6S(1/2), F=4→6P(3/2), F'=5 transition, where Γ0/2π=5.2 MHz in free space. An optical depth d≃66 is observed, corresponding to an optical depth per atom d1≃0.08. These advances provide an important capability for the implementation of functional quantum optical networks and precision atomic spectroscopy near dielectric surfaces.

Crossed solitary renal ectopia.

A boy being followed for cardiovascular anomalies was found at age fourteen to have a solitary right kidney which drained to the left side of the bladder. We have reviewed the reports of 33 patients with solitary crossed renal ectopia which describe many associated congenital anomalies especially in the genitourinary and skeletal systems. We found no description of associated cardiac anomalies. We review the literature on solitary crossed renal ectopia and describe an additional case.

Crossed fused renal ectopia.

An unusual form of crossed renal ectopia is presented. Both kidneys are at the same level on the same side with fusion throughout their entire lengths.

Primary hydronephrosis. Assessment of diuretic renography, pelvis perfusion pressure, operative findings, and renal and ureteral histology.

Hydronephrosis generally implies ureteropelvic junction obstruction, but may be mimicked by a variety of other disorders. The authors have attempted to determine the relative diagnostic value of diuretic renography and the pelvis perfusion test in children with hydronephrosis by correlating the results with operative findings, renal and ureteral histology, and postoperative results.

Pelviureteric obstruction in childhood.

Pelviureteric junction obstruction is a common cause of intra-abdominal mass in childhood. The diagnosis is usually apparent when the characteristic signs of obstruction are seen at intravenous urography. A voiding cystourethrogram should be performed to exclude vesicoureteral reflux as the underlying condition. Obstruction may be further assessed by a diuretic load or by pressure-flow studies.

Radiographic manifestations of renal anomalies.

Intrauterine sonography has revolutionized the detection of renal anomalies. Previously unavailable demonstrations of abnormalities pose a new challenge to those responsible for the care of these patients. Optimal management is dependent on knowledge of the natural history of the demonstrated abnormality, the sequelae, and also the results and the complications of the various forms of available treatment.

Intussusception. Issues and controversies related to diagnosis and reduction.

Diagnosis and management of intussusception remain controversial. The authors discuss the evolution of changes and advances in practice and procedures. They advocate sonographic diagnosis and air enema reduction; the abdominal radiograph is reserved for children with clinical evidence of peritonitis and suspected perforation, if clinical findings are unusual, or if the sonographic examination is equivocal.

Intussusception: toward less surgery?

Since the 1950s, several large pediatric centers have used hydrostatic reduction with barium under fluoroscopic control as the treatment method of choice for ileocolic intussusception and have adopted rigid criteria for its management. One such rule has been that in order for an intussusception to be completely reduced, there must be adequate reflux of barium into the distal ileum. If this did not occur, it was assumed that the ileocolic intussusception had not been reduced, and the infant or child was taken straight to the operating room for laparotomy and surgical treatment. However, 10% of such intussusceptions were found to have reduced spontaneously. Needless to say, nonoperative management reduces morbidity and shortens hospitalization. From October 1985 through March 1991, 503 air contrast colon studies for suspected intussusception were performed on infants and children aged 2 days to 13 years (average, 16.8 months); 262 (52%) were normal, and 241 had an intussusception, 196 (81%) of which were reduced. The remaining 45 were operated on. In three patients (4 months to 2 years of age) the air enema reduced the intussusception from the colon without terminal ileum filling, but they all became asymptomatic immediately. For this reason they were not operated on; they were admitted and observed for 24 to 48 hours. Two of the three had recurrence of abdominal pain the next morning, but results of repeat air enemas were all normal (no intussusception observed, and normal terminal ileum filling).(ABSTRACT TRUNCATED AT 250 WORDS)

Efficient routing of single photons by one atom and a microtoroidal cavity.

Single photons from a coherent input are efficiently redirected to a separate output by way of a fiber-coupled microtoroidal cavity interacting with individual cesium atoms. By operating in an overcoupled regime for the input-output to a tapered fiber, our system functions as a quantum router with high efficiency for photon sorting. Single photons are reflected and excess photons transmitted, as confirmed by observations of photon antibunching (bunching) for the reflected (transmitted) light. Our photon router is robust against large variations of atomic position and input power, with the observed photon antibunching persisting for intracavity photon number 0.03 < or approximately similar n < or approximately similar 0.7.

Prolapsing ectopic uretroceles in boys.

Five cases of prolapsing ectopic ureterocele are described. All five patients were boys and all had duplex kidneys; in four cases this duplication was bilateral. There was significant obstructive uropathy in all of the cases. It is easy to overlook the diagnosis of prolapsing ectopic ureterocele or to misdiagnose the condition as posterior urethral valves. The importance of careful cystourethrographic evaluation is emphasized.

Prolapse of an ectopic ureterocele into both urethra and ipsilateral orthotopic ureter.

Ectopic ureteroceles frequently prolapse into the urethra. Inversion of ureteroceles into their own ureters has also been described. This patient showed a ureterocele which not only prolapsed into the urethra but also into the ipsilateral orthotopic ureter. We have not seen nor found a description of prolapse of a ureterocele into the ipsilateral orthotopic ureter.

Transient opacification of the urinary pathways by amorphous debris in children with leukemia.

Our index patient, a 14-year-old male on chemotherapy for acute lymphatic leukemia had extensive opacification of the urinary tract on the preliminary film for an intravenous urogram. Sonography and computed tomography also demonstrated dense material in the calyces, renal pelves and ureters. Since then, we have found another patient, a 9-year-old female with acute lymphatic leukemia who was not receiving chemotherapy, with a similar pattern on sonography and computed tomography. These densities unlike those in our first patient were not visible on a plain film of the abdomen. All of the material disappeared spontaneously in both patients.

Sonographic appearances of inverted Meckel diverticulum with intussusception.

This study illustrates the sonographic findings of inverted Meckel diverticulum acting as a lead point of an intussusception in five patients. In four patients, the inverted diverticulum was seen as a segment of blind-ending, thick-walled bowel projecting for a variable distance from the apex of the intussusceptum. The larger diverticula had a characteristic bulbous shape. The central serosal surface of the inverted diverticulum was filled with fluid in one patient, with fluid and fat in another, and with echogenic fat only in the other two. The presence of fat was confirmed by CT in one patient. The features illustrated in these four patients appear to be specific. In the fifth patient, the sonogram revealed a nonspecific echogenic mass at the apex of the intussusceptum. Recognition of these features on sonography may obviate the need for further investigation.

Plain abdominal radiography in suspected intussusception: a reassessment.

The objectives of the study were (1) to determine the interobserver variation in interpretation of abdominal radiographs in children with clinically suspected intussusception, and (2) to determine the diagnostic value of abdominal radiographs in these patients. One hundred and eighty-two plain abdominal radiographic examinations (AXR) performed in children with clinically suspected intussusception were reviewed blind to the clinical history and findings of air enema. The presence or absence of nine AXR signs relevant to intussusception was documented. Each AXR was categorized as equivocal, positive or negative for intussusception, with the aim of achieving no false negatives. Interobserver variation in the identification of AXR signs and radiologic diagnoses was calculated using the kappa statistic for 60 cases assessed independently by three observers. Using the findings of air enema as gold standard, the prevalence of AXR signs in all patients with (60) and without (122) intussusception was determined and their diagnostic values calculated. The best observer agreement was for the presence of sparse small bowel gas (supine, k = 0.68) and the worst for the presence of cecal gas (erect, k = 0.18). All three observers agreed intussusception to be present or absent in only 7 of 60 cases and the majority agreement was equivocal in more than half. Overall agreement between observers for the diagnosis of intussusception was k = 0.30. The best positive predictors of intussusception were the soft tissue mass and sparse large bowel gas, with likelihood ratios of 3.9 and 2.5. Cecal feces predicted against intussusception, likelihood ratio 0.11. AXR was equivocal in 53%, positive in 21% and negative in 26%. Where a firm radiographic diagnosis was made, the diagnostic accuracy of AXR was 84%.(ABSTRACT TRUNCATED AT 250 WORDS)

Pneumatic reduction of intussusception: 5-year experience.

Pneumatic reduction of 246 intussusceptions was attempted in 219 patients over a 5-year period. The mean age of the patients was 15.4 months. Successful reduction was achieved in 199 cases (80.9%). Bowel perforation occurred in seven cases (2.8%), requiring needle decompression of tension pneumoperitoneum in one case. Recurrence of intussusception occurred in 27 cases (11%). The mean fluoroscopy time was 3.5 minutes +/- 0.2 in successful reductions and 9.3 minutes +/- 0.9 in failed reductions (P less than .001). Logistic regression analysis helped identify four independent predictors of failure, as follows: (a) ileoileocolic intussusception (P less than .001), (b) long duration of symptoms (P less than .001), (c) rectal bleeding (P less than .01), and (d) failed reduction with barium at another institution (P less than .05). Predictors of bowel perforation were a younger age (P less than .05) and long duration of symptoms (P less than .05). Surgery was performed in 48 cases (19.5%), 16 of which required bowel resection. Transmural necrosis of bowel wall was found in nine specimens. The most important predictor of outcome in this series was a long duration of symptoms. Pneumatic reduction is a useful substitute for barium in the management of pediatric intussusception.

Colo-colic intussusception associated with pneumatosis cystoides intestinalis.

This paper describes pneumatosis cystoides intestinalis in association with colo-colic intussusception in a young teenager. The intussusception was easily reduced at barium enema. The recognition of the characteristic filling defects in the barium column facilitates a correct diagnosis. This association has only been reported previously in six adults.

The value of sonography, CT and air enema for detection of complicated Meckel diverticulum in children with nonspecific clinical presentation.

BACKGROUND: Complicated Meckel diverticulum (MD) in children does not always present with painless rectal bleeding and its presentation can then produce a difficult diagnostic dilemma. In this clinical setting, sonography (US), CT or even air enema may be the first modality chosen to evaluate these children rather than the radionuclide Meckel scan (RNMS). PURPOSE: To assess the value of US, CT and air enema for detection of complicated MD. MATERIALS AND METHODS: Review of clinical, imaging, surgical and pathological findings in 64 children (55 males, 9 females) aged 4 days -14 years (mean = 3.7 years) with MD seen during an 8-year period, 1990-1997. RESULTS: (a) In 33 patients with rectal bleeding, MD was detected on RNMS in 32. Ten of these 32 had other imaging studies, all of which were negative. (b) The other 31 patients, with varied clinical presentations, did not undergo RNMS. In these 31 and the 1 with a negative RNMS, 14 (44 %) had imaging features highly suggestive for the diagnosis of MD on US in all 14, on CT in 1, and on air enema in 3. The radiological spectrum of the inflamed, hemorrhagic MD is illustrated. CONCLUSION: The inflamed, hemorrhagic and the inverted, intussuscepted MD have a spectrum of features recognizable on US, CT and air enema. Some of these appearances are specific, others are not. Knowledge of and recognition of these features will facilitate detection of complicated MD in larger numbers of children presenting with symptoms other than the classic history of painless rectal bleeding and also in those with normal RNMS.

Spontaneous reduction of intussusception: clinical spectrum, management and outcome.

BACKGROUND: To analyze the spectrum of clinical features, management and outcome of children with documented spontaneous reduction of intussusception (SROI). MATERIALS AND METHODS: Review of records of 50 children (33 boys, 17 girls; age range 11 days-15 years; mean age 4 years) with documented SROI, in whom intussusception was initially diagnosed by sonography (US) in 44, air enema in 2, and computed tomography in 4, in the 6-year period 1992-1998. RESULTS: Symptoms suggestive of intussusception were present in 21 (3 of whom had Henoch-Schönlein purpura and 4 had previous ileocolic intussusception reduced by air enema). Intussusception was an incidental finding in the other 29, in 28 of whom the finding was in the small bowel. Intussusception was limited to the small bowel in 43 and was ileocolic in 7. SROI was usually documented on US. Laparotomy performed in only 4 showed no evidence of intussusception or pathologic lead point. Outcome in all patients was favorable. CONCLUSIONS: SROI may present in symptomatic or asymptomatic children and occurs more commonly than previously reported. These intussusceptions are usually short-segment, small-bowel intussusceptions with no recognizable lead point. In asymptomatic patients, conservative observation is warranted. Intervention should be dictated by the clinical findings in symptomatic patients.