Evolution of beam distribution in crossing a Walkinshaw resonance.

The third-integer coupling resonance at ν(x)-2ν(z)=ℓ, known as the Walkinshaw resonance, is important in high-power accelerators. We find that, when the betatron tunes ramp through a Walkinshaw resonance the fractional emittance growth (FEG) is a universal function of the effective resonance strength: G(1,-2,ℓ)√[ε(xi)]|Δ(ν(x)-2ν(z))/Δn|(-1/2), where G(1,-2,ℓ) is the resonance strength; ε(xi) and ε(zi) are the initial horizontal and vertical emittances, respectively; and |Δ(ν(x)-2ν(z))/Δn| is the resonance crossing rate per revolution. At large effective resonance strengths, the FEG reaches an asymptotic maximum value (FEG)(max)~2ε(xi)/ε(zi) for ε(xi)>>1/2ε(zi) or ε(zi)/(2ε(xi)) for ε(xi)<<1/2ε(zi). There is little emittance exchange at ε(xi)=1/2ε(z), which can be used to minimize emittance growth in crossing a Walkinshaw resonance.

Quadruple-bend achromatic low emittance lattice studies.

A quadruple-bend achromatic (QBA) cell, defined as a supercell made of two double-bend cells with different outer and inner dipole bend angles, is found to provide a factor of 2 in lowering the beam emittance relative to the more conventional double-bend achromat. The ratio of bending angles of the inner dipoles to that of the outer dipoles is numerically found to be about 1.5-1.6 for an optimal low beam emittance in the isomagnetic condition. The QBA lattice provides an advantage over the double-bend achromat or the double-bend nonachromat in performance by providing a small natural beam emittance and some zero-dispersion straight sections. A lattice with 12 QBA cells and a preliminary dynamic aperture study serves as an example.

Factors associated with intestinal perforation in children's non-typhi Salmonella toxic megacolon.

BACKGROUND: To evaluate the risk factors for intestinal perforation in children with toxic megacolon caused by non-typhi Salmonella infection. METHODS: During an 11-year period we reviewed the records of children treated for non-typhi Salmonella infection. All of the subjects had positive stool culture for non-typhi Salmonella and were treated with intravenous ceftriaxone during hospitalization. Clinical data reviewed included demographic features, clinical manifestations, laboratory findings, radiologic findings, microbiology, therapeutic effect of hydration and rectal tube placement and the operative findings. Patients with toxic megacolon were defined as those having toxic appearance, diarrhea, high fever (>39 degrees C) and marked colon dilatation with maximal diameter > 1.5 times the width of the vertebra body of the first lumbar spine (L1-VB). To define the risk factors for patients with toxic megacolon complicated by intestinal perforation, patients were divided into two groups for analysis: P group, those complicated with intestinal perforation; and NP group, those without intestinal perforation. Differences in age, sex, severity of diarrhea, duration of fever, hemogram and its differential, culture, stool analysis, serum C-reactive protein (CRP), electrolytes, maximal colon diameter, medical therapy and timing of rectal tube insertion between the two groups were analyzed. Statistical analyses were conducted with chi square tests and multiple logistic regression. RESULTS: A total of 75 patients (P group, 27 patients; NP group, 48 patients) ages 4 months to 6 years were evaluated. With chi square analysis 7 variables were found to be significantly associated with intestinal perforation: age >1 year; fever >5 days; ratio of immature to total neutrophils >20%; serum CRP >200 mg/l; colon diameter >2.5 times the width of L1-VB; inadequate early hydration; and delay in rectal tube insertion. With multivariate analysis age >1 year, serum CRP >200 mg/l and colon diameter >2.5 times of width of L1-VB, inadequate early hydration and delay in rectal tube insertion were the most significant factors associated with intestinal perforation. CONCLUSION: Identification of patients with toxic megacolon associated with non-typhi Salmonella infection at risk for further intestinal perforation is possible. Early effective fluid resuscitation and rectal tube insertion may be helpful to prevent the occurrence of intestinal perforation.

Description and demonstration of a CMOS amplifier-based-system with measurement and stimulation capability for bioelectrical signal transduction.

An extracellular recording system incorporating an electrode array and an amplifier/stimulator CMOS chip is described and characterized. Important features of this custom VLSI chip include 16 instrumentation amplifiers with a gain of 50 and the incorporation of a cross-point array allowing designation of an extracellular microelectrode as either a stimulator or sensor. The planar array consisted of 32 microelectrodes, 14 microns in diameter, and four larger reference electrodes. Microelectrodes, interconnecting traces, and bond pads were patterned with a 500-nm layer of gold. The interconnecting traces were passivated with a 1-micron thick layer of silicon nitride to provide chemical and electrical insulation and microelectrode impedance was lowered utilizing electrode position of platinum black. The amplifier exhibited a nearly flat frequency response with high pass and low pass corner frequencies of 0.7 Hz and 50 kHz, respectively. The input referred noise over the 50 kHz bandwidth was 12-16 microVRMS, well below the magnitude of previously reported extracellular potentials. Crosstalk between neighboring channels resulted in an output signal below the amplifier noise level, even for relatively large extracellular potentials. Using this system, extracellular recording were demonstrated yielding typical peak-to-peak biopotentials of magnitude 0.9-2.1 mV and 100-400 microV for chick cardiac myocytes and rat spinal cord neurons, respectively. The key components of this extracellular recording system can be manufactured using industry standard thin film photolithographic techniques.

Senescent human fibroblasts have elevated Ku86 proteolytic cleavage activity.

A proteolytic activity capable of cleaving the Ku86 subunit of Ku protein to two polypeptides, with molecular masses of 69 and 17 kDa in vitro, is present in a human diploid fibroblast (HDF) cell line. The activity is elevated in late-passaged and senescent cells, and the cleaved 69-kDa product seems able to form complex with Ku70 to bind DNA ends. However, further studies indicate that cleavage of Ku86 could be inhibited by including leupeptin in the extraction buffer, and no 69 kDa variant was evident in the cell. In fact, the levels of Ku86, Ku70 and DNA-end binding activity of Ku remained unchanged during replicative senescence. Thus, this study reveals an intriguing protease in HDFs, and also indicates that inconsistent results of Ku86 expression will be obtained if the protease activity is not completely inhibited.

Localised hyaline vascular type of Castleman's disease mimicking adult-onset Still's disease.

A previously healthy 18-year-old boy presented with daily spiking fever, polyarthritis, and evanescent skin rashes, as well as hepatomegaly and Raynaud's phenomena for 2 months. He was initially diagnosed with adult-onset Still's disease (AOSD). During the period of follow-up, intermittent fever and migratory polyarthritis persisted and an insidiously growing mass over the right axillary region was noted 1 year after the diagnosis of AOSD. Excisional biopsy of the mass revealed a group of lymph nodes with histological features of the hyaline vascular type of Castleman's disease. The patient's symptoms disappeared soon after excision of the lymph nodes. evanescent rash, lymphadenopathy, hepatosplenomegaly and serositis [5]. A clinical picture compatible with the diagnosis of AOSD has not been described in the localised hyaline vascular type of Castleman's disease. We report such a case in an 18-year-old male patient who presented prolonged fever and polyarthritis with an initial diagnosis of AOSD. The diagnosis of hyaline vascular type of Castleman's disease was made 1 year later, when the patient developed an insidiously growing mass over the right axilla.

Different articular outcomes of Still's disease in Chinese children and adults.

The clinical manifestations, treatment and course, and articular outcomes of 24 children with juvenile-onset Still's disease (JOSD) and 21 adults with adult-onset Still's disease (AOSD) were compared retrospectively. There was no significant difference in the initial clinical and laboratory manifestations except that more adults presented with a sore throat (81% vs. 46%, p = 0.03). Although serum ferritin was almost always elevated in both diseases, adults had significantly higher serum ferritin concentrations compared with those of children. Steroid treatment was required in 71% of children and 52% of adults, while disease-modifying antirheumatic drugs were used in 42% of children and 24% of adults during the course. Chronic arthritis (>6 months) occurred in comparable proportions of patients with JOSD and AOSD (46% vs 38%, p = 0.82), irrespective of the disease pattern (monocyclic or polycyclic). However, severe deforming arthritis with marked functional limitation occurred only in JOSD, particularly with polyarthritis at disease onset (more than five affected joints). In contrast, AOSD patients with chronic arthritis had a favourable functional outcome at the end of the follow-up. Our study suggested different articular outcomes of Still's disease in Chinese children and adults.

Continuous blood glucose monitoring with feedback-controlled glucose infusion during surgical management of insulinoma: report of a case.

Perioperative management of insulinoma may be facilitated by the use of a glucose-controlled insulin infusion system (GCIIS; Biostator System, Miles Laboratories Inc., Elkhart, Ind.). We monitored the blood glucose levels and glucose infusion rates before, during and after surgery in a 35-year-old woman with insulinoma. After an overnight fast, glucose was infused according to a preset program and maintained the blood glucose level at around 50 mg/dl. Depression of the blood glucose level and simultaneous elevation of the glucose infusion rate were noted when the tumor was massaged. A sharp decrease in the glucose infusion rate occurred almost immediately after removal of the tumor. It took about 4 minutes for the blood glucose to go up to a level of 90 mg/dl. These results demonstrate the usefulness of GCIIS not only in maintaining stationary blood glucose, but also in localizing the tumor and in providing evidence of complete removal of the tumor. When the infusion system is programmed appropriately, the glucose infusion rate, as compared to the blood glucose level, reacts more quickly and sensitively to sudden changes in insulin levels.

Serum eosinophil cationic protein determination in asthmatic children-effect of different collecting tubes used for blood sampling.

We compared the effect of using 2 different serum collecting tubes, serum separation tubes (SST, with clot activator and gel barrier) and conventional glass tubes (with no additives), on circulating levels of eosinophil cationic protein (ECP) in asthmatic children and controls. The serum ECP values obtained from both SST and glass tubes were significantly higher in asthmatic children than in corresponding controls. ECP values were higher in serum samples using SST than in those using glass tubes (P<0.01), while no difference was found between the two in controls. ECP levels correlated with peripheral eosinophil counts, for SST samples and glass tube samples alike. The difference in ECP levels between these two tubes also correlated with circulating eosinophil counts (r = 0.62, P = 0.004) After 18-hour storage at room temperature, the ECP values increased significantly in samples obtained from asthmatic children. No difference in ECP values between SST samples and glass tube samples was found for 18 hour samples. Thus, ECP levels obtained from SST samples and glass tube samples, though reliable, should not be directly compared, especially in asthmatic children with eosinophilia.

Hepatobiliary involvement of Henoch-Schönlein purpura in children.

Hepatobiliary manifestation and its evolution in children with Henoch-Schönlein purpura (HSP) had been scarcely reported. Over a ten-year period between June 1988 and November 1998, medical charts of 225 children with the diagnosis of HSP encountered at Chang Gung Children's Hospital were reviewed. Those with the evidence of hepatobiliary involvement were enrolled in the study. The patients with hepatobiliary involvement were defined by having an elevated serum alanine transaminase (ALT) or gamma-glutamyl transferase (GGT), and the presence of abnormal sonographic findings involving liver, biliary system, and gallbladder. The patients included 9 boys and 11 girls with range of age from 3 to 11 years. The mean age of these patients was 6.5 +/- 3.7 years. Preceding upper respiratory tract infection was common in these patients (35%). The main clinical manifestation were distinct from typical abdominal symptoms of HSP, and included right upper quadrant pain (80%), nausea (45%), lethargy (20%), and vomiting (15%). Elevated serum ALT was noted in 15 cases (75%) and GGT in 6 cases (30%). Abdominal ultrasonography revealed hepatomegaly (15/20, 75%), and gallbladder wall thickening (5/20, 25%). No specific laboratory parameters were correlated with the hepatobiliary manifestation of HSP. Fourteen children (70%) received steroid therapy and disappearance of symptoms and sonographic resolution of hepatobiliary lesion was noted within 3-7 days of steroid therapy. All patients recovered completely except for one patient with hepatobiliary recurrence manifested as purpuric rash, abdominal pain, elevated GGT, and gallbladder wall thickening during 2-year follow-up.

Papillary cystic neoplasm of the pancreas in children: report of three cases.

Papillary cystic neoplasm of the pancreas is very rare in children. There were only 35 pediatric cases reported in the literature. We herein three children who had papillary cystic neoplasm of pancreas. They were female teenagers, and were pathologically diagnosed. The major presenting symptoms were abdominal pain and abdominal mass. Serum tumor markers of these patients showed normal results. A CT scan of these patients showed that this tumor was of pancreatic origin. These 3 tumors were localized to head, body, and tail, respectively. The mean maximal diameter of these tumors was 11.3 +/- 3 cm. Sonography and CT examination showed that the tumor was a heterogeneous mass with solid and cystic components. Angiography of this tumor showed a hypervascular mass with blood supply mainly from pancreatic branch of splenic artery. They all underwent tumor resection. All tumors contained some degree of internal hemorrhage or cystic degeneration and all were well encapsulated. Histologically, tumor cells generally showed solid and pseudopapillary growth around the fibrovascular stalks. No metastasis, mortality or recurrence was noted during follow-ups. In conclusion, CT scan helps to make a prospective diagnosis of papillary cystic neoplasm of pancreas. Our study confirmed that a papillary neoplasm of the pancreas is a low-grade malignant tumor. Surgical resection of the tumor is the mainstay of effective management.

Congenital diaphragmatic hernia diagnosed by magnetic resonance imagine in late infancy: Report of one case.

We report the magnetic resonance imagine (MRI) findings of an 11-month-old baby with delay onset of congenital diaphragmatic hernia (CDH). The capability of visualizing diaphragmatic discontinuity, connecting bowel segments between abdomen and chest are clearly demonstrated. The various techniques of diagnosing diaphragmatic hernia are described and we emphasize the potential usefulness of MRI in CDH.

A follow-up study of systemic-onset juvenile rheumatoid arthritis in children.

We analyzed the clinical and laboratory features, treatment, and course of twenty-one children with systemic-onset juvenile rheumatoid arthritis (S-JRA) encountered at our institution over the past ten years. There were eleven boys and ten girls. The mean age at onset was 11.6 +/- 4.2 years. The mean duration of symptoms prior to diagnosis was 5.5 +/- 1.7 months, and the mean follow-up period was 45.7 +/- 9.5 months. The clinical and laboratory features at presentation were similar to previous reports, except that peripheral blood smear revealed toxic granulation of neutrophils in 60% of our patients. Although systemic manifestation could be readily controlled by non-steroidal anti-inflammatory drugs (NSAIDs) with or without additional steroids, nine patients suffered from chronic arthritis (duration > 6 months) requiring disease-modifying anti-rheumatic drugs (DMARDs). Of the nine children with chronic arthritis, six (67%) had a monocylic systemic course, and seven (78%) had polyarticular disease (five or more joints affected) at the disease onset. Five patients developed severe destructive polyarthritis, with persistent anemia, thrombocytosis, elevated serum C-reactive protein (CRP) levels, and marked functional limitation during follow-up. One of the five patients with severe arthritis developed systemic lupus erythromatosis after 8-year follow-up, and died of sepsis. Our study indicated significant morbidity in children with S-JRA in Taiwan.

Prompt recognition of necrotizing fasciitis in a newborn.

We report a 13-day-old female neonate with necrotizing fasciitis, who presented with fever and erythema on her back. Rapidly progressive extension of the erythema to the abdominal wall occurred within 12 hours. Sonography for the lesion showed extensive fascial thickening with fluid accumulation. An abscess was also demonstrated. Necrotizing fasciitis was highly suspected. Under sonographic guidance, pus was aspirated from the abscess. A smear for the aspirated pus revealed a large number of neutrophils and abundant gram-positive cocci. Immediate surgical debridement was done. Cultures from the pus and blood revealed Staphylococcus aureus. The patient was free of symptoms after surgical debridement and aggressive antibiotic therapy. She had skin grafting to reconstruct the debrided wound on the 20th hospital day and was discharged shortly after the debridement of wound.

Sonographic and color Doppler sonographic diagnosis of acute osteomyelitis: report of one case.

Acute osteomyelitis in childhood is uncommon. Early diagnosis is often difficult. We present a 7-year-old boy with clinical manifestation of fever and progressive left thigh swelling for one week. Sonography of the left thigh showed periosteal thickening with subperiosteal abscess around the metaphysis of the left distal femur. Tc-99m bone scintigraphy showed increased uptakes at the left distal femur. Osteomyelitis was suspected from the examination of ultrasound and bone scan examinations. His symptoms were not relieved following systemic antibiotic therapy and a follow-up color Doppler sonography showed vascular flows within and around the periosteum indicating active inflammation. He finally received surgical drainage and the operative findings confirmed the diagnosis of osteomyelitis. In conclusion, ultrasound may be a helpful and convenient tool for establishing the early diagnosis of pediatric osteomyelitis. Ultrasound and color Doppler sonography can be used as clinical parameters to evaluate the disease severity and the progression of osteomyelitis in children.

Acute gastroenteritis caused by multiple enteric pathogens in children.

Of 303 children hospitalized with acute non-bloody, non-mucoid diarrhoea, 69 (22.8%) had polymicrobial infection, including 52 (17.2%) multiple viral infection and 17 (5.6%) viral and bacterial co-infection. Rotavirus had the most important role in both categories; thus the control of rotavirus infection is crucial for maintaining children's health in Taiwan.

Comparison of the effect of a cornstarch thickened formula and strengthened regular formula on regurgitation, gastric emptying and weight gain in infantile regurgitation.

The purpose of this study was to evaluate the efficacy of a specially selected cornstarch-supplemented formula on clinical symptoms, gastric emptying and weight gain in infants with regurgitation. We performed a prospective randomised trial evaluating the therapeutic efficacy of two different formula feedings (cornstarch-thickened formula, group A; 25% strengthened formula, group B) in 81 young infants with regurgitation/vomiting > or = 3 times/day. A Tc-99 m milk scintigraphy was performed at inclusion and after 2 months to quantify gastric emptying time; all studied infants underwent a 2-month period of clinical follow-up evaluating regurgitation and body weight gain. At inclusion, group A and B had a similar age and weight. After the 2-month period of intervention, regurgitation and vomiting had both greater decrease (both P < 0.001 at 1 and 2 months) in group A (from a score of 4.19 +/- 1.71 to 0.93 +/- 0.42) than in group B (from a score of 4.15 +/- 1.68 to 2.89 +/- 1.16). Non-regurgitation symptoms (irritability, cough, choking, night-waking) decreased (P = 0.045 at 1 month and 0.017 at 2 months) in group A (from a score of 18 at baseline to 3 after 8 weeks) as compared to group B (from a score of 18 at baseline to 11 after 8 weeks). Weight increased more in group A (29.1 +/- 3.9 g/day over 8 weeks) versus group B (23.6 +/- 3.5 g/day over 8 weeks) (P < 0.01 at 1 and 2 months) Gastric emptying improved significantly in group A as compared with group B (all P < 0.001 for T1/2, and residual volume at 60 and 90 min). Ingested feeding volume was significantly larger in the group receiving cornstarch-thickened formula, both at 4 weeks (109.4 +/- 24.5 vs. 98.5 +/- 23.6 mL/meal) (P: 0.042) and at 8 weeks (137.6 +/- 27.9 vs. 115.7 +/- 26.5 mL/meal) (P < 0.001). Cornstarch-thickened formula feeding decreases the frequency of regurgitation/vomiting, provides better body weight gain and has an accelerated gastric emptying in comparison to a 25% strengthened regular formula in infants with regurgitation.

Non-traumatic colon perforation in children: a 10-year review.

Colon perforation is an abdominal surgical emergency in the pediatric population, but is seldom reported when occurring from non-traumatic causes in children beyond the neonate. The goal of this study was to identify the clinical characteristics, management, and outcomes of non-traumatic colon perforation in children. Medical records for the 10-year period from September 1994 to September 2004 were reviewed for children beyond the neonate with non-traumatic colon perforation. Data gathered included age, gender, symptoms, duration of symptoms, physical findings, and length of postoperative hospital stay. Diagnostic information included laboratory data, radiographic imaging, and operative findings. Forty-four patients with non-traumatic colon perforation were recruited into this study. The mean age was 2.22 +/- 1.87 years; 91.4% of cases were younger than 5 years old. The most common presenting symptom was fever (97.7%); the most common sign was abdominal distention (93.1%). The mean duration of symptoms prior to admission was 6.19 days. Pneumoperitoneum was presented in 86.3% of patients by plain abdominal radiograph. Ascending and transverse colon were the most common perforation sites. Non-typhoid salmonella was the leading pathogen isolated, causing 20.4% of episodes. One case died due to Clostridium speticum infection. Non-traumatic colon perforation most commonly affects children younger than 5 years of age. It may be secondary to infection, especially non-typhoid salmonella. Plain abdominal radiograph can be an adjuvant tool for the high index of suspicion for colon perforation in children with abdominal distention and history of fever or diarrhea for more than 5 days.

Los probioticos tienen eficacia clinica, microbiologica e inmunolólica en la diarrea infecciosa aguda / Probiotics have clinical efficacy, microbiological and immunological acute infectious diarrhea

La diarrea infecciosa aguda es una causa importante de morbilidad en la infancia y responsable de unacarga económica para las familias. Es este estudio se evaluó las características clínicas, microbiológicas,inmunológicas y efectos de los probióticos en diarrea infecciosa aguda.