Diastolic/systolic blood pressure ratio for predicting febrile children with sepsis and progress to septic shock in the emergency department

OBJECTIVE

Given the scarcity of studies analyzing the clinical predictors of pediatric septic cases that would progress to septic shock, this study aimed to determine strong predictors for pediatric emergency department (PED) patients with sepsis at risk for septic shock and mortality.

METHODS

We conducted chart reviews of patients with ≥ 2 age-adjusted quick Sequential Organ Failure Assessment score (qSOFA) criteria to recognize patients with an infectious disease in two tertiary PEDs between January 1, 2021, and April 30, 2022. The age range of included patients was 1 month to 18 years. The primary outcome was development of septic shock within 48 h of PED attendance. The secondary outcome was sepsis-related 28-day mortality. Initial important variables in the PED and hemodynamics with the highest and lowest values during the first 24 h of admission were also analyzed.

RESULTS

Overall, 417 patients were admitted because of sepsis and met the eligibility criteria for the study. Forty-nine cases progressed to septic shock within 48 h after admission and 368 were discharged without progression. General demographics, laboratory data, and hemodynamics were analyzed by multivariate analysis. Only the minimum diastolic blood pressure/systolic blood pressure ratio (D/S ratio) during the first 24 h after admission remained as an independent predictor of progression to septic shock and 28-day mortality. The best cutoff values of the D/S ratio for predicting septic shock and 28-day mortality were 0.52 and 0.47, respectively.

CONCLUSIONS

The D/S ratio is a practical bedside scoring system in the PED and had good discriminative ability in predicting the progression of septic shock and in-hospital mortality in PED patients. Further validation is essential in other settings.

Sustained acute kidney injury as an independent risk factor for neurodevelopmental and growth outcomes in a single NICU center

PURPOSE

Acute kidney injury (AKI) is commonly seen in neonatal intensive care units (NICUs) and is potentially associated with adverse prognoses in later stages of life. Our study evaluated the impact of sustained AKI (SAKI) on both neurodevelopmental impairment (NDI) and early growth restriction (EGR) in neonates.

METHODS

This case-control study retrospectively analyzed the medical records of neonates diagnosed with SAKI in the NICU of a tertiary medical center during the period from January 2007 to December 2020. Cases without subsequent follow-up and those resulting in death were excluded. We analyzed demographic, biochemical, and clinical outcome data.

RESULTS

Of the 93 neonates with SAKI, 51 cases (54.8%) were included in this study, while 42 cases (45.2%) were excluded due to a lack of follow-up or death. An age-matched control group comprised 103 neonates, who had never experienced AKI or SAKI, were selected at random. In total, 59 (38.3%) cases were identified as NDI and 43 (27.9%) as EGR. Multivariate analysis revealed that patients with SAKI had significantly higher risks of developing NDI (odds ratio, [OR] = 4.013, p = 0.001) and EGR (OR = 4.894, p < 0.001). The AKI interval had an area under the receiver operating characteristic curve of 0.754 for NDI at 9.5 days and 0.772 for EGR at 12.5 days.

CONCLUSIONS

SAKI is an independent risk factor for both NDI and EGR in neonates. Consequently, regular monitoring, neurological development assessments, and appropriate nutritional advice are crucial to these infants who have experienced renal injury.

Predicting factors for acute encephalopathy in febrile seizure children with SARS-CoV-2 omicron variant: a retrospective study

BACKGROUND

SARS-CoV-2 posed a threat to children during the early phase of Omicron wave because many patients presented with febrile seizures. The study aimed to investigate predicting factors for acute encephalopathy of children infected by SARS-CoV-2 Omicron variant presenting with febrile seizures.

METHODS

The retrospective study analyzed data from pediatric patients who visited the emergency department of Chang Gung Memorial Hospital in Taiwan between April and July 2022. We specifically focused on children with COVID-19 who presented with febrile seizures, collecting demographic, clinical, and laboratory data at the pediatric emergency department, as well as final discharge diagnoses. Subsequently, we conducted a comparative analysis of the clinical and laboratory characteristics between patients diagnosed with acute encephalopathy and those with other causes of febrile seizures.

RESULTS

Overall, 10,878 children were included, of which 260 patients presented with febrile seizures. Among them, 116 individuals tested positive for SARS-CoV-2 and of them, 14 subsequently developed acute encephalopathy (12%). Those with acute encephalopathy displayed distinctive features, including older age (5.1 vs. 2.6 years old), longer fever duration preceding the first seizure (1.6 vs. 0.9 days), cluster seizure (50% vs. 16.7%), status epilepticus (50% vs. 13.7%) and occurrences of bradycardia (26.8% vs. 0%) and hypotension (14.3% vs. 0%) in the encephalopathy group. Besides, the laboratory findings in the encephalopathy group are characterized by hyperglycemia (mean (95% CI) 146 mg/dL (95% CI 109-157) vs. 108 mg/dL (95% CI 103-114) and metabolic acidosis (mean (95% CI) pH 7.29(95% CI 7.22-7.36) vs. 7.39 (95%CI 7.37-7.41)).

CONCLUSIONS

In pediatric patients with COVID-19-related febrile seizures, the occurrence of seizures beyond the first day of fever, bradycardia, clustered seizures, status epilepticus, hyperglycemia, and metabolic acidosis should raise concerns about acute encephalitis/encephalopathy. However, the highest body temperature and the severity of leukocytosis or C-reactive protein levels were not associated with poor outcomes.

Ferritin as an Effective Predictor of Neurological Outcomes in Children With Acute Necrotizing Encephalopathy

BACKGROUND

Acute necrotizing encephalopathy (ANE) is a fulminant disease with poor prognosis. Cytokine storm is the important phenomenon of ANE that affects the brain and multiple organs. The study aimed to identify whether hyperferritinemia was associated with poor prognosis in patients with ANE.

METHODS

All patients with ANE had multiple symmetric lesions located in the bilateral thalami and other regions such as brainstem tegmentum, cerebral white matter, and cerebellum. Neurological outcome at discharge was evaluated by pediatric neurologists using the Pediatric Cerebral Performance Category Scale. All risk factors associated with poor prognosis were further analyzed using receiver operating characteristic curve analysis.

RESULTS

Twenty-nine patients with ANE were enrolled in the current study. Nine (31%) patients achieved a favorable neurological outcome, and 20 (69%) patients had poor neurological outcomes. results The group of poor neurological outcome had significantly higher proportion of shock on admission and brainstem involvement. Based on multivariate logistic regression analysis, ferritin, aspartate aminotransferase (AST), and ANE severity score (ANE-SS) were the predictors associated with outcomes. The appropriate cutoff value for predicting neurological outcomes in patients with ANE was 1823 ng/mL for ferritin, 78 U/L for AST, and 4.5 for ANE-SS. Besides, comparison analyses showed that higher level of ferritin and ANE-SS were significantly correlated with brainstem involvement (P < 0.05).

CONCLUSIONS

Ferritin may potentially be a prognostic factor in patients with ANE. Hyperferritinemia is associated with poor neurological outcomes in patients with ANE and ferritin levels more than 1823 ng/mL have about eightfold increased risk of poor neurological outcome.

BNT162b2 immunization-related myocarditis in adolescents and consequent hospitalization: Report from a medical center

BACKGROUND

To investigate Pfizer-BioNTech 162b2 mRNA COVID-19 vaccine (BNT162b2) immunization-related myocarditis and describe the risk factors for consequent hospitalization in the pediatric intensive care unit (PICU) in children between 12 and 18 years.

METHODS

Children and adolescents 12 years of age and older who presented with discomfort after BNT162b2 immunization (BNTI) and visited pediatric emergency room (PER) at Chang Gung Memorial Hospital from September 22, 2021 to March 21, 2022, were included for analysis.

RESULTS

681 children presented with discomfort after BNTI and visited our PER. The mean age was 15.1 ± 1.7 years. Three hundred and ninety-four (57.9%) and 287 (42.1%) events were after 1st and 2nd dose, respectively. 58.4% (n = 398) were male. The most common complaints were chest pain (46.7%) and chest tightness (27.0%). The median (interquartile range [IQR]) interval of discomfort after BNTI was 3.0 (1.0-12.0) days. BNTI-related pericarditis, myocarditis and myopericarditis were diagnosed in 15 (2.2%), 12 (1.8%) and 2 (0.3%) patients, respectively. Eleven (1.6%) needed hospitalization in PICU. The median (IQR) hospital stay was 4.0 (3.0-6.0) days. There was no mortality. More patients were diagnosed myocarditis (p = 0.004) after 2nd dose BNTI. PICU admission occurred more commonly after 2nd dose BNTI (p = 0.007). Risk factors associated with hospitalization in PICU were abnormal EKG findings (p = 0.047) and abnormal serum troponin levels (p = 0.003) at PER.

CONCLUSION

Myocarditis in children aged 12-18 years occurred more commonly following 2nd dose BNTI. Most cases were of mild or intermediate severity without death. Factors predicting BNTI-related myocarditis and consequent hospitalization in PICU were abnormal EKG findings and abnormal serum troponin levels at PER in this study.

Diastolic blood pressure impact on pediatric refractory septic shock outcomes

BACKGROUND

Septic shock is the progression of sepsis, defined as cardiovascular dysfunction during systemic infection, and it has a mortality rate of 40 %-80 %. Loss of vascular tone is an important pathophysiological feature of septic shock. Diastolic blood pressure (DBP) was reported to be associated with vascular tone. This study aimed to identify the associations of several hemodynamic indices, especially DBP, with outcome in pediatric septic shock to allow for timely interventions.

METHODS

Children with persistent catecholamine-resistant shock had a pulse index continuous cardiac output (PiCCO®) system implanted for invasive hemodynamic monitoring and were enrolled in the current study. Serial cardiac index, systemic vascular resistance index (SVRI), systolic blood pressure (SBP), mean arterial pressure (MAP), and DBP were recorded during the first 24 h following PiCCO® initiation. All hemodynamic parameters associated with 28-day mortality were further analyzed using receiver operating characteristic curve analysis.

RESULTS

Thirty-three children with persistent catecholamine-resistant shock were enrolled. The median age was 12 years and the youngest children were 5 years old. Univariate analysis noted that SVRI, SBP, MAP, and DBP were significantly higher, and shock index was significant lower, in survivors compared with non-survivors (p < 0.05). In the multivariate analysis, only SVRI and DBP remained independent predictors of 28-day mortality. DBP had the best correlation with SVRI (r = 0.718, n = 219, p < 0.001). The area under the receiver operating characteristic curves of SVRI and DBP for predicting 28-day mortality during the first 24 h of persistent catecholamine-resistant shock were >0.75, indicating a good prediction for mortality.

CONCLUSIONS

DBP correlated well with SVRI and it can serve as a predictor for mortality in pediatric septic shock. Furthermore, DBP was a superior discriminator of mortality when compared with SBP and MAP. A lower DBP was an independent hemodynamic factor associated with 28-day mortality.

Predictors of disease severity and outcomes in pediatric patients with croup and COVID-19 in the pediatric emergency department

BACKGROUND

Croup caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is an emerging disease, and data on the risk factors associated with disease severity are still limited. The Westley croup score (WS) is widely used to assess croup severity. The current study aimed to analyze biomarkers associated with the WS and clinical outcomes in patients with croup and coronavirus disease 2019 in the pediatric emergency department (PED).

POPULATION AND METHOD

Patients diagnosed with croup caused by SARS-CoV-2 were admitted at two PEDs. Clinical data including age, WS, length of hospital stay, initial laboratory data, and treatment were analyzed. Clinical parameters were evaluated via multivariate logistic regression analysis. The best cutoff values for predicting croup severity and outcomes were identified using the receiver operating characteristic curve.

RESULT

In total, 250 patients were assessed. Moreover, 128 (51.2%) patients were discharged from the PED, and 122 (48.8%) were admitted to the hospital. Mild, moderate, and severe croup accounted for 63.6% (n = 159), 32% (n = 80), and 4.4% (n = 11) of all cases, respectively. A high mean age (years), neutrophil count (%), neutrophil-to-lymphocyte ratio (NLR), ALT (U/L), procalcitonin (ng/mL), and hemoglobin (g/dL) level, and length of hospital stay (days), and a low lymphocyte count (%) and blood pH were associated with croup severity and need for intensive care. Based on the multivariate logistic regression model, the NLR remained independent factors associated with croup severity and prognosis. Further, NLR was significantly correlated with WS. The area under the receiver operating characteristic curve of NLR for predicting a WS of ≥3 was 0.895 (0.842-0.948, p < 0.001), and that for predicting ICU admission was 0.795 (0.711-0.879, p < 0.001). The best cutoff values for a WS of ≥3 and ICU admission were 1.65 and 2.06, respectively.

CONCLUSION

NLR is correlated with WS and is a reliable, easy-to-use, and cheap biomarker for the early screening and prognosis of croup severity in the PED. A higher NLR may indicate severe croup and the need for further treatment. And the WS score remains reliable for estimating the severity of croup caused by SARS-CoV-2 and the risk of intensive care.

Factors Determining Testicular Torsion and Consequent Orchiectomy in Pediatric Patients Presenting With Scrotal Pain

OBJECTIVE

Factors associated with testicular torsion (TT) and consequent orchiectomy in patients presenting to pediatric emergency departments (PEDs) with scrotal pain (SP) are not well described. We report the factors predicting TT and consequent orchiectomy in children with SP.

METHODS

The data on patients (aged ≤18 years) who presented with SP to PEDs at 4 branches of the Chang Gung Hospital through 10 years were analyzed.

RESULTS

In all, 256 pediatric patients presented with SP. Their mean age was 11.60 ± 4.61 years and 72.7% (n = 186) were aged 10 to 18 years. The pain was left-sided in 54.7% (n = 140) and the interval between SP onset and PED arrival was 22.45 ± 31.27 hours. Overall, 84 (32.8%) patients needed surgery and 72 (28.1%) had TT. Of the patients with TT, 28 (38.9%) patients needed an orchiectomy. After analysis, TT and consequent orchiectomy were associated with a longer interval between SP onset and PED arrival, absent of testicular ultrasonic blood flow, interval between SP onset and surgery of more than 24 hours, and a high degree of TT. None of them experienced recurrent SP symptoms or TT again.

CONCLUSIONS

The rate of TT in patients presenting to PEDs with an SP was 28.1%, and 38.9% of the patients with TT needed an orchiectomy. Early diagnosis and intervention helped to prevent subsequent orchiectomy in pediatric patients with TT.

Microstructure and fracture toughness of hot-rolling biomedical degradable ZKX500 magnesium bone plates

In this study, the microstructure and fracture toughness of ZKX500 magnesium alloy under different processing were investigated. The results show that the as-extruded (FH) consists of coarsen and fine grains with higher residual stress. The fracture toughness and crack propagation are significantly distinct along different directions. By contrast, the rolled specimen (FRH) shows an equiaxed grain structure and precipitation dispersion in the matrix. After hot-rolling and heat treatment, less texture effect affected on the fracture toughness and rupture energy absorption. These renders the higher attractive on the rolled ZKX500 magnesium alloy in the applications of orthopedic bone plates.

The pathological spectrum of pediatric kidney disease: 18-Year experience from a single tertiary care center in northern Taiwan

BACKGROUND

Glomerular disease is one of the leading causes of chronic kidney disease in children worldwide. Recent studies outlined the changing spectrum of glomerular disease in certain countries. Therefore, our study aimed to evaluate the histopathological patterns and changes in pediatric kidney disease over the past 18 years in northern Taiwan.

METHODS

This was a retrospective chart review study of pediatric patients (≤18 years of age) undergoing percutaneous renal biopsies (PRBs) of native kidneys between January 2002 and July 2020 from a Pediatric Care Center at Chang Gung Memorial Hospital, Taoyuan, Taiwan.

RESULTS

This study analyzed a total of 339 pediatric native PRBs. The mean age of the subjects was 13.7 ± 7.0 years (184 girls and 155 boys). The most common indications of PRBs included acute nephritic syndrome (55.7%), idiopathic nephrotic syndrome (22.7%), persistent asymptomatic hematuria (13.9%), and unexplained renal failure (7.7%). Our study revealed that proliferative lupus nephritis (LN), minimal change disease (MCD)-related nephrotic syndrome, and IgA nephropathy (IgAN) were the most frequent biopsy-proven pediatric glomerular diseases. In addition, we showed that severe acute post-streptococcal glomerulonephritis (APSGN) was infrequent and has not even been diagnosed since 2010.

CONCLUSION

Our result revealed that the spectrum of biopsy-proven pediatric kidney disease has not changed significantly over the past two decades. Furthermore, proliferative LN, MCD, and primary IgAN continue to be the most common histopathological diagnoses among Taiwanese children.

Serum electrolyte abnormalities in pediatric patients presenting to an emergency department with various diseases: Age-related differences

BACKGROUND

This study evaluated the prevalence and frequency of serum electrolyte abnormalities (SEAs) in children presenting to a pediatric emergency department (PED) with various diseases.

METHODS

Pediatric patients (≤18 years) with blood electrolyte panels obtained in the PED of Lin-Kou Chang Gung Memorial Hospital, Taiwan, in the 5 years from January 1, 2016, to August 31, 2021, were enrolled in this retrospective observational study. Patients were divided into three age groups: Group A, < 4 years; Group B, 4-11 years; and Group C, 12-18 years. The associations between SEAs and clinical diseases in children and age-related differences were assessed.

RESULTS

This study included 182,058 pediatric patients visiting our PED over a 5-year period. A total of 250 (0.14%) patients with SEAs were included in the analysis. The study population consisted of 127 boys and 123 girls with a median (IQR) age of 9.0 (3.2-14.1) years. Hospital admission was required in 86.4% (n = 216) of the patients, and 32.4% (n = 81) of them were admitted to the pediatric intensive care unit (PICU). The median (IQR) hospital stay and PICU stay was 6.5 (4.0-11.0) and 4.0 (3.0-8.0) days, respectively. The PICU stay was longer in Group A (p < 0.05) and shorter in group C (p < 0.05). Hyponatremia was the most common SEA in group A (46.3%, n = 31), while hypokalemia was common in groups B (54.2%, n = 52) and C (32.2%, n = 28). Gastrointestinal, renal, and endocrine diseases were common clinical conditions associated with SEAs in pediatric patients in our PED.

CONCLUSION

The detection rate of SEAs in patients in the PED was 0.14%. Hyponatremia was a common SEA in pediatric patients aged <4 years, while the most common electrolyte disorder in those >4 years old was hypokalemia. In infants and young children, SEAs were associated with a longer PICU stay.

Mechanical properties and biomedical application characteristics of degradable polylactic acid-Mg-Ca3(PO4)2 three-phase composite

Polylactic acid (PLA), pure magnesium powder, and calcium phosphate powder were used to form a three-phase degradable biomedical composite. The effects of various powder proportions in polylactic acid-Mg-Ca₃(PO₄)₂ composites were analyzed through mechanical and biological tests, which revealed that both the tensile and impact strength of the composite increased. Additionally, ductility presented only after a small proportion of powder was added. Hardness slightly increased because of dispersion strengthening. Furthermore, the addition of pure magnesium and calcium phosphate accelerated the degradation rate, and biocompatible salts were generated after degradation, which can improve healing and renewal in bone tissue. None of the composites exhibited cytotoxicity, meeting biological safety requirements. Overall, PLA10M10C (10 wt.% Mg, 10 wt.% Ca₃(PO₄)₂) exhibited superior performance. Accordingly, PLA10M10C can serve as a reference for degradable biomedical material applications in orthopedic implants.

Household cleaning products poisoning in a pediatric emergency center: A 10- year cross-sectional study and literature review

BACKGROUND

Poisoning by household cleaning products(HCPs) is common in children. Some HCPs are toxic and may cause severe complications. We assessed HCP poisonings treated in a pediatric emergency department(PED).

METHODS

This was a retrospective study of patients aged under 18 years with HCP poisoning admitted to the largest PED in Taiwan from 2011 to 2020 were recruited.

RESULTS

The records over a 10-year period from 103 children admitted to the PED because of HCP poisoning(70 boys [68%] and 33 girls [32%]), mean age 3.54 years(standard deviation [SD] = 3.15 years) were evaluated. Most poisonings were unintentional(99%, n = 102) and occurred at home(96%, n = 99). The HCPs included alkaline(74%, n = 76), acidic(25%, n = 26), and neutral(1%, n = 1) agents. Most were orally ingested(86%, n = 89). Panendoscopy was performed in 25 patients(24%), and the endoscopic(Zargar) grade was used to determine the severity of injury. Medications(steroids [9%, n = 9], antibiotics [10%, n = 10], or antacids [30%, n = 23]) were prescribed. Alkaline HCP ingestion induced severe esophageal injury(p = 0.04) and esophageal stricture(p = 0.04). Five patients(5%) exhibited esophageal strictures and required balloon dilation. On multivariate analysis, alkaline HCP ingestion(p = 0.04), severe esophageal caustic injury(Zargar grade ≥ 3) (p < 0.001), and medications(steroids [p < 0.001], antibiotics [p < 0.001], and antacids [p = 0.001]) were associated with esophageal stricture.

CONCLUSION

Alkaline HCP ingestion and severe esophageal caustic injury(Zargar grade ≥ 3) were associated with esophageal stricture. Physicians tended to prescribe medications(steroids, antibiotics, or antacids) for patients with severe esophageal injuries to reduce the risk of esophageal stricture. The usefulness of these medications requires further study.

Photocatalysis in gold nanocage nanoreactors

The photodegradation of methyl orange was found to take place very efficiently using hollow Au nanocages which are known to have remaining Ag on their interior walls which can be oxidized to Ag(2)O. The degradation rate is found to be more efficient than photodegradation reaction using semiconductor nanomaterials, such as TiO(2) and ZnO. The reaction rate is found to increase by increasing the degree of Ag oxidation on the interior wall of the nanocages prior to the reaction and is a function of the nanocavity size and the pore density of the nanocage walls. As the cage size varies, it is found that the photocatalytic rate increases and then decreases with a maximum rate at nanoparticle size of 75 nm with a medium pore density in the walls. All these results suggest that the catalysis is occurring inside the cavity, whose interior walls are covered with the Ag(2)O catalysts. Similar to the mechanism proposed in the degradation by the other semiconductors, we propose that the photodegradation mechanism involves the formation of the hydroxyl radical resulting from the photoexcitation of the Ag(2)O semiconductor. The observed results on the rate are discussion in terms of (1) the surface area of the inner wall covered with Ag (Ag(2)O), (2) the density and size of the pores in the walls, and (3) the cavity size of the nanoparticles.

A sieving method for collecting the metacercariae of trematode parasites from freshwater fish

This study describes a sieving method for the collection of metacercariae from frozen (-20 degrees C) freshwater fish. Digested fish tissue is filtered through a series of sieves; the crude filtrate is then centrifuged. Centrifugation produces a sediment from which metacercariae can be removed. Half of the metracercariae that were obtained from the fish meat that had been frozen for 10 days (-20 degrees C) were dead; the other half were alive and some larvae were moving slowly.

Urinary tract infection in children

Two hundred and eighty-five children under 15 years old (169 boys and 116 girls) who had urinary tract infection (UTI) were admitted to our hospital during the period July 1995 to June 1998. Clinical presentation, laboratory data and image studies were recognized and analyzed. Most patients were younger than 2 years of age. Fever is the most common sign, especially in young children. With the urinary dipstick test a low positive rate of nitrite reaction (34.7%) was found. E. coli is the most common pathogen and exclusively resistant to ampicillin (90.2%). The E. coli is also relatively resistant to trimethoprim/sulfamethoxazole (57.1%). Voiding cystourethrogram was performed in 187 cases, in which 24.6% of those patients showed vesicoureteric reflux. Ninety-eight children received 99mTc-dimercaptosuccinic acid renal scans and 62 cases (63.3%) had abnormal findings compatible with pyelonephritis. The positive predictive values by renal ultrasonography for vesicoureteric reflux and pyelonephritis are 30.7% and 78.9%, respectively. In pyelonephritis patients, only 37% also had a vesicoureteric reflux. The fever duration and clinical inflammatory parameters were evaluated in all patients. Longer febrile periods are the risk of vesicoureteric reflux and pyelonephritis, and a high C-reactive protein concentration indicates the risk of pyelonephritis. In conclusion, fever was the most common sign in young UTI children who had a low positive nitrite reaction rate in the dipstick test. E. coli was the most common pathogen with a high ampicillin resistance in Taiwan. Only 37% pyelonephritis patients had refluxing nephropathy. It is indicated that pyelonephritis is not always attributed to reflux of infected urine. A longer febrile period and a high C-reactive protein level are good indicators for prediction of the risk of pyelonephritis in UTI patients.

Prevalence and treatment of Pediculus capitis infestation among aboriginal school children in northern Taiwan

In the present study, pediculosis was investigated among a total of 2,725 children from 35 primary schools in Hsiulin District of Hualien County, Jenai District of Nantou County, Wulai District of Taipei County, Chienshih District of Hsinchu County, Fushing District of Taoyuan County, and Nanao District of Ilan County. The overall infestation rate was 12.8%. The rates by districts were 19.7%, 17.3%, 16.7%, 15.1%, 7.9%, and 3.0%, respectively. The pediculicides including Nix (permethrin 1%) 56 gm/tube, Para aerosol (bioallethrin 0.66%) 90 gm/tube, and Perioderm (malathion 1%) cream shampoo 40 gm/tube were used to treat the head louse infestation in 83, 91, and 103 children; the cure rates were 97.3%, 94.1%, and 93.4%, respectively. No significant differences were found in these rates. The reactions were slight and transitory. A total of 636 lice was collected from the hair using fine-toothed combs before treatment and from the used towels after treatment of children in Wulai, Chienshih, Hsiulin, and Jenai Districts. Each child was found infested with a mean of 7.7 lice. The mean intensity of infestation was highest in Jenai (9.3) and Chienshih (8.7) came next. Wulai (3.7) and Hsiulin (3.6) had lower intensities.

An adaptive training method for optimal interpolative neural nets

In contrast to conventional multilayered feedforward networks which are typically trained by iterative gradient search methods, an optimal interpolative (OI) net can be trained by a noniterative least squares algorithm called RLS-OI. The basic idea of RLS-OI is to use a subset of the training set, whose inputs are called subprototypes, to constrain the OI net solution. A subset of these subprototypes, called prototypes, is then chosen as the parameter vectors of the activation functions of the OI net to satisfy the subprototype constraints in the least squares (LS) sense. By dynamically increasing the numbers of subprototypes and prototypes, RLS-OI evolves the OI net from scratch to the extent sufficient to solve a given classification problem. To improve the performance of RLS-OI, this paper addresses two important problems in OI net training: the selection of the subprototypes and the selection of the prototypes. By choosing subprototypes from poorly classified regions, this paper proposes a new subprototype selection method which is adaptive to the changing classification performance of the growing OI net. This paper also proposes a new prototype selection criterion to reduce the complexity of the OI net. For the same training accuracy, simulation results demonstrate that the proposed approach produces smaller OI net than the RLS-OI algorithm. Experimental results also show that the proposed approach is less sensitive to the variation of the training set than RLS-OI.

STARDUST: finessing expensive cometary sample returns

The STARDUST Discovery mission will collect samples of cometary coma and interstellar dust and return them to Earth. Five years after launch in February 1999, coma dust in the 1- to 100-micrometers size range will be captured by impact into ultra-low-density silica aerogel during a 6 kms-1 flyby of Comet Wild 2. The returned samples will be investigated at laboratories where the most critical information on these primitive materials is retained. The Jet Propulsion Laboratory will provide project management with Lockheed Martin Astronauts as the spacecraft industrial partner. STARDUST management will aggressively and innovatively achieve cost control through the use of Total Quality Management principles, the chief of which will be organization in a Project Engineering and Integration Team that "flattens" the traditional hierarchical structure by including all project elements from the beginning, in a concurrent engineering framework focusing on evolving Integrated Mission Capability.