In situ XAFS experiments using a microfluidic cell: application to initial growth of CdSe nanocrystals.

The design and performance of a compact fluorescense XAFS apparatus equipped with a microfluidic cell for in situ studies of nanoparticles are described. CdSe nanoparticles were prepared by solution reaction starting from trioctylphosphine-Se. Time-resolved experiments were performed by precisely controlling the reactor coordinates (x,y), allowing the synchrotron X-ray beam to travel along a reactor channel, covering nucleation and initial growth of nanoparticles. Detailed analysis of EXAFS data combined with UV-vis spectra allow reliable estimation of particle size and density in the initial growth that cannot be accessible by conventional optical techniques based on a long-range order. The Se K-XANES spectra are interpreted by multi-scattering calculations providing bond formation kinetics consistent with the EXAFS data.

Fluorescence X-ray absorption spectroscopy using a Ge pixel array detector: application to high-temperature superconducting thin-film single crystals.

A Ge pixel array detector with 100 segments was applied to fluorescence X-ray absorption spectroscopy, probing the local structure of high-temperature superconducting thin-film single crystals (100 nm in thickness). Independent monitoring of pixel signals allows real-time inspection of artifacts owing to substrate diffractions. By optimizing the grazing-incidence angle theta and adjusting the azimuthal angle phi, smooth extended X-ray absorption fine structure (EXAFS) oscillations were obtained for strained (La,Sr)2CuO4 thin-film single crystals grown by molecular beam epitaxy. The results of EXAFS data analysis show that the local structure (CuO6 octahedron) in (La,Sr)2CuO4 thin films grown on LaSrAlO4 and SrTiO3 substrates is uniaxially distorted changing the tetragonality by approximately 5 x 10(-3) in accordance with the crystallographic lattice mismatch. It is demonstrated that the local structure of thin-film single crystals can be probed with high accuracy at low temperature without interference from substrates.

A case of ischemic jejunal stricture after surgical reduction of intussusception.

A 15-year-old girl presented with small bowel obstruction due to ischemic jejunal stricture which developed three weeks after successful surgical reduction of an intussusception with a Peutz-Jeghers-type polyp as a lead point. The reduced jejunum had no macroscopic injury, and the stricture caused complete obstruction requiring jejunal resection.

In situ X-ray absorption fine structure detection of reversible photoinduced anisotropy in amorphous selenium.

Photoinduced anisotropy in amorphous selenium ( a-Se) has been studied by in situ x-ray absorption fine structure spectroscopy. It is found that upon irradiation with linearly polarized light the chainlike fragments in a-Se are oriented with their c-axis perpendicular to the polarization plane of the inducing light. This chain orientation is reversible, correlates with optical anisotropy, and acts as a prelude to photoinduced anisotropic crystallization. This optically controlled reorientation of molecular fragments in a solid can be a basis for future novel devices.

Local structure of Ge nanocrystals embedded in SiO2 studied by X-ray absorption fine structure.

Local structure of Ge nanocrystals embedded in SiO2 has been studied by X-ray absorption fine structure on the Ge K-edge. The XANES and EXAFS results indicate that Ge atoms in samples with the Ge concentration x=25-40 mol. % are coordinated with oxygen atoms, while they exist as amorphous Ge clusters in samples with x=60 mol. %. Upon annealing, completely relaxed crystalline Ge phase is formed for samples with x=60 mol. %, in contrast to the x=25-40 mol. % sample, which show little or no indication of Ge cluster formation. A possible mechanism of Ge nanocluster formation is discussed.

Clinicopathologic relationship of hypoganglionosis.

BACKGROUND/PURPOSE: Congenital motor dysfunction of the intestine associated with a morphologically abnormal myenteric nervous plexus (MP) is known as Hirschsprung's disease allied disorder (HAD). However, the clinicopathologic features of HAD are not well understood, partially because a standardized method of histologic evaluation of MP has not been established. To elucidate the clinicopathologic relationship of HAD the authors reviewed 6 cases of HAD using a newly devised histologic evaluation method. METHODS: Flat-mounted frozen sections of the ileum were stained for S-100 protein by fluorescent immunohistochemistry. Quantitative evaluation of MP was performed by measuring the fluorescence-positive area (MP ratio), and the results were compared with those of age-matched normal controls. RESULTS: All of 6 patients required laparotomy within 1 month after birth and enterostomy between 23 days and 10 months. Three died of intractable enteritis by the age of 2.2 years and were totally dependent on parenteral nutrition (PN) throughout their lives. The other 3 have survived for 6 to 10 years but have required PN occasionally. MP ratio in controls was more than 0.34 at all ages, whereas that in HAD was significantly lower than that in controls according to the clinical severity. CONCLUSION: MP size measured on 2-dimensional demonstration is suggested to be an indicator of clinical severity of HAD. J Pediatr Surg 36:898-900.

Laparoscopic ovarian cystectomy using a single umbilical puncture method.

To establish a minimally invasive technique to perform ovarian cystectomy, the authors applied a single umbilical puncture method. A 2-month old female infant was admitted to the hospital because of an ovarian cyst that showed no spontaneous shrinkage after her birth. An umbilical semicircular incision was made to insert a 10-mm trocar, into which a 3-mm laparoscope was inserted. The ovarian cyst was grasped using forceps inserted through an operating channel of the scope, and the cyst was removed through the incision. After aspiration of the cyst, the free cyst wall was resected, leaving the intact ovarian tissue. The operation was performed without difficulty or complication. The postoperative course was uneventful. The wound was inconspicuous, and the result was cosmetically excellent. The case demonstrated the feasibility of the minimally invasive technique using a single umbilical puncture for ovarian cystectomy in an infant.

Prognostic significance of polysialic acid expression in resected non-small cell lung cancer.

Polysialic acid (PSA) is a carbohydrate attached mainly to the neural cell adhesion molecule. Because PSA is composed of a linear homopolymer of alpha-2-8-linked sialic acid residues and has a large negative charge, the presence of PSA attenuates the adhesive property of neural cell adhesion molecule and increases cellular motility. In an earlier study, we demonstrated that PSA and STX, a polysialyltransferase, were associated with tumor progression in non-small cell lung cancer (NSCLC) (F. Tanaka et al., Cancer Res., 60: 3072-3080, 2000). Therefore, in the present study, to assess the prognostic significance of PSA in resected NSCLC, a total of 236 patients who underwent complete resection for pathological (p)-stage I-IIIa disease were reviewed retrospectively. PSA was expressed in 44 of 236 (18.6%) patients, and the expression was correlated with p-stage disease. For all p-stage patients, 5-year survival rates for those with PSA-positive and PSA-negative tumors were 52.1% and 71.3%, respectively, demonstrating a significantly worse prognosis for the PSA-positive patients (P = 0.012). Analysis for only p-stage I patients also demonstrated a significantly worse prognosis for the PSA-positive patients; 5-year survival rates of the PSA-positive and the PSA-negative patients were 45.1% and 83.5%, respectively, (P < 0.001). In addition, there proved to be no difference in the postoperative survival among p-stage I, II, and IIIa patients when PSA expression was positive. Multivariate analysis confirmed that PSA expression was an independent factor to predict poor prognosis in resected NSCLC. These results suggested that PSA could be an important clinical marker and that preoperative induction and/or postoperative adjuvant therapies should be performed for PSA-positive NSCLC, even if the disease is classified as p-stage I.

Clinical significance of caspase-3 expression in pathologic-stage I, nonsmall-cell lung cancer.

Caspase-3 is a cysteine protease that plays an important role in the process of apoptotic cell death. Whereas many studies on the clinical significance of apoptosis in the therapy of malignant tumors have been reported, little has been studied clinically on caspase-3. In the present study, the clinical significance of caspase-3 expression in resected nonsmall-cell lung cancer (NSCLC) and its correlation with incidence of apoptosis were examined. A total of 118 consecutive patients who had undergone complete resection for pathologic Stage I NSCLC were retrospectively reviewed. Caspase-3 expression was examined immunohistochemically using a polyclonal antibody that recognized uncleaved caspase-3. The 5-year survival rate for patients with strong expression of caspase-3 (66.6%) was significantly lower than that for patients with weak expression (82.1%, P = 0.021). Expression of caspase-3 was not correlated with incidence of apoptosis, proliferative activity, or p53 status. Multivariate analysis confirmed that strong expression of caspase-3 was a significant factor to predict poor prognosis. These results suggest that enhanced expression of "uncleaved" caspase-3, that is, inactivated caspase-3, was correlated with poor prognosis in resected NSCLC.

Surgical intervention for emphysematous pulmonary regions in a postoperative infant with congenital diaphragmatic hernia.

A postoperative infant with congenital diaphragmatic hernia (CDH) developed extrinsic obstruction of the trachea by the innominate artery that ensued from unequal expansion of the lungs followed by left mediastinal shift. Septation of the anterior mediastinum prevented unequal expansion of the lungs, and elongation of the innominate artery improved proximal airway obstruction. Prolonged artificial ventilation, however, resulted in the emphysematous bullae in the left lung. Lung volume reduction surgery (LVRS), at 3 years of age, ameliorated the respiratory distress and resulted in good weight gain. Surgical intervention, including LVRS, should be considered to improve respiratory disturbance caused by difference in compliance of the lungs in children.

Two cases of persistent hyperinsulinemic hypoglycemia that showed spontaneous regression and maturation of the Langerhans islets.

Near-total pancreatectomy has been recommended as the treatment for persistent hyperinsulinemic hypoglycemia (PHH) in infants. However, recently there has been a report described that one third of 95% pancreatectomy failed to prevent hypoglycemia and more than two thirds had diabetes ultimately. The authors experienced 2 cases of PHH, which raise a query about the extensive pancreatectomy. Case 1: A female patient who manifested PHH shortly after birth underwent less extensive pancreatectomy twice at age 2 months and 8 years. After each operation, her clinical symptoms regressed, and she became free from the disease eventually. Histologic findings showed nesidioblastosis in which the islets clearly matured. Case 2: A male infant with PHH had an absolute indication for pancreatectomy. However, after a meticulous control of the blood glucose level with parenteral nutrition followed by continuous enteral nutrition feeding combined with medication, he became free from the disease. The current cases show there exist cases of PHH in which the islets mature and symptoms regress spontaneously. Therefore, we conclude near-total pancreatectomy is not always the treatment of choice. As an alternate strategy, long-term controlled feeding and medication combined with or without less extensive pancreatectomy should be considered with the expectation of spontaneous regression.

Total parenteral nutrition-associated intrahepatic cholestasis in infants: 25 years' experience.

BACKGROUND/PURPOSE: There are few long-term chronological reviews examining the incidence of total parenteral nutrition (TPN)-associated intrahepatic cholestasis (TPNAC) in infants. The authors therefore reviewed TPNAC in their 25-year series, and also looked at the current problems associated with TPN in infants. METHODS: Two hundred seventy-three surgical neonates who received TPN for more than 2 weeks were divided into 3 groups chronologically: group A (1971 through 1982, n = 77), group B (1983 through 1987, n = 72), and group C (1992 through 1996, n = 124). TPNAC was defined as serum direct bilirubin (DB) level greater than 2.0 mg/dL during the neonatal period. RESULTS: The incidence of TPNAC in groups A, B and C was 57%, 31%, and 25% (P< .01), respectively, and the mortality rate from TPN-associated complications was 13%, 3%, and 3% (P< .05), respectively. Over the last 5 years, severe TPNAC developed in 20 patients (16%). Four of 20 died of TPN-associated sepsis with hepatic failure; 2 had hypoganglionosis with intractable stagnant enteritis and subsequent sepsis, and 2 had fatal respiratory or cardiac disease. CONCLUSIONS: The incidence of TPNAC in surgical neonates and TPN-associated mortality rates have decreased significantly. The mortality rate, however, still remains at 3%. Two of 4 fatal cases had hypoganglionosis, which were totally dependent on TPN. In patients who require long-term TPN, TPN still has unsolved problems, and small bowel transplantation may be indicated.

Rapid and sensitive XAFS using a tunable X-ray undulator at BL10XU of SPring-8.

The design and performance of the high-brilliance XAFS facility at BL10XU of SPring-8, aimed at rapid and sensitive measurement of X-ray absorption fine structure (XAFS), is reported. Both undulator gap and double-crystal monochromator have been successfully controlled covering a wide energy range (5-30 keV). A versatile goniometer system, consisting of two independent high-precision goniometers, is capable of polarized XAFS in fluorescence mode and surface-sensitive experiments using a grazing-incidence geometry. By sharing major components, i.e. a monolithic Ge 100-pixel array detector and a closed-cycle He cryostat, both polarized XAFS and X-ray standing wave (XSW) experiments can be performed at low temperature (15-300 K). The performance of the spectrometer has been evaluated by recording XAFS spectra in transmission mode.

Congenital ileal atresia presenting as a single cyst-like lesion on prenatal sonography.

A routine prenatal sonographic examination at 37 weeks' menstrual age revealed a large sonolucent lesion with peristaltic movement in the abdomen of a fetus. After birth, the female infant showed progressive abdominal distention, and radiography showed a bubble-like dilatation of the small intestine. Exploratory laparotomy revealed ileal atresia with nearby partial torsion of the dilated small bowel. The incomplete torsion may have functioned as a check valve, inducing segmental dilatation of the ileum without proximal dilatation.

Handlebar hernia: case report and review of pediatric cases.

The authors describe a rare case of handlebar hernia in a 9-year-old-boy. All layers of his abdominal wall were disrupted by a fall on a bicycle; however, his skin and intra-abdominal organs were completely intact. Computed tomography demonstrated subcutaneous intestinal loops protruding through the rent. Surgical repair was performed, and his postoperative course was uneventful.

Subcapsular hemorrhage of the liver in a very-low-birth-weight neonate: survival after decompression laparotomy.

Subcapsular hemorrhage of the liver in a very-low-birth-weight neonate was successfully treated by decompression laparotomy. This may be the second smallest survivor after surgery in the literature.

Enteral nutrition prevents bacterial translocation but does not improve survival during acute pancreatitis.

OBJECTIVE: To evaluate the effect of enteral nutrition (EN) in attenuating bacterial and/or endotoxin translocation, maintaining immune responsiveness, and improving outcome in early acute pancreatitis (AP) in Wistar male rats. DESIGN: Acute pancreatitis was induced in rats receiving total parenteral nutrition (TPN) (AP/TPN group) (n=34) and EN (AP/EN group) (n=35) by pressure injection of 1% deoxycholate into the biliopancreatic duct (0.6 mg/kg of body weight). Rats in the sham/TPN and sham/EN groups (n=10 each) underwent laparotomy without induction of AP. Catheters for TPN and EN were placed into the external jugular vein and jejunum, respectively. Rats were infused with Ringer lactate solution for 48 hours followed by TPN in the AP/TPN and sham/TPN groups, and EN in the AP/EN and sham/EN groups until day 7. The fluid volume and energy (calories) intake were similar in all groups. SETTING: Medical school research laboratory. MAIN OUTCOME MEASURES: Survival, blood endotoxin level, villus height, 5-bromo-2'-deoxyuridine (BrdU) uptake in the jejunum and ileum, bacterial culture of mesenteric lymph nodes, and CD4/CD8 ratio of T cells in mesenteric lymph nodes, spleen, and peripheral blood. RESULTS: There was no difference in survival and pancreatic healing between the AP/TPN and AP/EN groups. Colony-forming units of the mesenteric lymph nodes and the endotoxin level were significantly lower in the AP/EN group than in the AP/TPN group (P<.05). Villus height and BrdU intake was significantly higher in the AP/EN group than in the AP/TPN group (P<.05). The CD4/CD8 ratio of T cells in spleen and peripheral blood was higher in the AP/EN group than in the AP/TPN group (P<.05), whereas there was no difference in mesenteric lymph nodes. CONCLUSIONS: Jejunal administration of EN is well tolerated in early AP, maintains immune responsiveness and gut integrity, and reduces bacterial and/or endotoxin translocation. However, compared with TPN, EN does not improve outcome. These results suggest that factors other than bacterial and/or endotoxin translocation may be responsible for mortality in this rat model of early AP. However, additional studies of both early bacterial and/or endotoxin translocation and late assessment of outcome are indicated.

Infantile myofibromatosis of the triceps detected by prenatal sonography.

A routine prenatal sonographic examination at 36 weeks' menstrual age revealed a solid and slightly inhomogeneous soft-tissue tumor on a fetus's left upper arm. The mass in the left triceps brachii muscle measured 8 x 7 x 5 cm at birth. Because of progressive flexion contracture of the left elbow joint, at 2 months of age the infant underwent radical resection of the tumor, sparing some muscle fibers. Light microscopic and immunohistochemical studies revealed myofibromatosis. Neither tumor nor functional disorder of the arm was evident 3 years after surgery.