Analgesic Effect of Low-Level Laser Therapy before Heel Lance for Pain Management in Healthy Term Neonates: A Randomized Controlled Trial

Currently, the prevention, assessment, and management of procedural pain in neonates continues to challenge clinicians and researchers. Objective. To investigate the analgesic effect of low-level laser therapy (LLLT) during heel lance compared to breast milk (BM) feeding in healthy term neonates. In this randomized controlled trial, healthy term neonates who underwent heel lance were randomly assigned to an LLLT or a BM group. The LLLT group received laser therapy to the heel lance site for 20 s before heel lance. The BM group received 5 mL expressed BM via a syringe before heel lance. The primary outcomes were behavioral responses. The secondary outcomes were physiological responses and levels of salivary cortisol and α-amylase. A total of 125 neonates were included, of whom 55 in the LLLT group and 59 in the BM group completed the study. There were no significant differences in latency to first cry and cry duration between the two groups. The squeeze time was significantly shorter in the LLLT group than in the BM group (p = 0.047). There were no significant differences in pain scores, heart rate, respiratory rate, oxygen saturation, and blood pressure before and after heel lance between the two groups. There were no significant differences in salivary cortisol and α-amylase levels in the LLLT group before and after heel lance; however, the differences were significant in the BM group. These findings suggest that the analgesic effect of LLLT is similar to that of BM during heel lance in healthy term neonates. LLLT has potential as an analgesic treatment.

Urinary levels of organophosphate flame retardants metabolites in a young population from Southern Taiwan and potential health effects

Background

Organophosphate flame retardants (OPFRs) are widely distributed in the environment and their metabolites are observed in urine, but little is known regarding OPFRs in a broad-spectrum young population from newborns to those aged 18 years.

Objectives

Investigate urinary levels of OPFRs and OPFR metabolites in Taiwanese infants, young children, schoolchildren, and adolescents within the general population.

Methods

Different age groups of subjects (n=136) were recruited from southern Taiwan to detect 10 OPFR metabolites in urine samples. Associations between urinary OPFRs and their corresponding metabolites and potential health status were also examined.

Results

The mean level of urinary Σ10 OPFR in this broad-spectrum young population is 2.25 μg/L (standard deviation (SD) of 1.91 μg/L). Σ10 OPFR metabolites in urine are 3.25 ± 2.84, 3.06 ± 2.21, 1.75 ± 1.10, and 2.32 ± 2.29 μg/L in the age groups comprising of newborns, 1-5 year-olds, 6-10 year-olds, and 11-18 year-olds, respectively, and borderline significant differences were found in the different age groups (p=0.125). The OPFR metabolites of TCEP, BCEP, DPHP, TBEP, DBEP, and BDCPP predominate in urine and comprise more than 90% of the total. TBEP was highly correlated with DBEP in this population (r=0.845, p<0.001). The estimated daily intake (EDI) of Σ5OPFRs (TDCPP, TCEP, TBEP, TNBP, and TPHP) was 2,230, 461, 130, and 184 ng/kg bw/day for newborns, 1-5 yr children, 6-10 yr children, and 11-17 yr adolescents, respectively. The EDI of Σ5OPFRs for newborns was 4.83-17.2 times higher than the other age groups. Urinary OPFR metabolites are significantly correlated with birth length and chest circumference in newborns.

Conclusion

To our knowledge, this is the first investigation of urinary OPFR metabolite levels in a broad-spectrum young population. There tended to be higher exposure rates in both newborns and pre-schoolers, though little is known about their exposure levels or factors leading to exposure in the young population. Further studies should clarify the exposure levels and factor relationships.

Neurally Adjusted Ventilatory Assist for Rapid Weaning in Preterm Infants

BACKGROUND

Neurally adjusted ventilatory assist (NAVA) is a new mode of subject-triggered ventilation. Experience with the use of NAVA in preterm infants is limited. This study compared the effects of invasive mechanical ventilation with NAVA to conventional intermittent mandatory ventilation (CIMV) in terms of reducing the duration of oxygen requirement and invasive ventilator support in preterm infants.

METHODS

This was a prospective study. We enrolled infants of less than 32 weeks' gestation who were then randomized to receive either NAVA or CIMV support during hospitalization. We recorded and analyzed data on the maternal history during pregnancy, use of medications, neonatal data at admission, neonatal diseases, and respiratory support in the neonatal intensive care unit.

RESULTS

There were 26 preterm infants in the NAVA group and 27 preterm infants in the CIMV group. Significantly fewer infants in the NAVA group received supplemental oxygen at 28 days of age (12 [46%] vs. 21 [78%], p = 0.0365), and they required significantly fewer days of invasive ventilator support: 7.73 (± 2.39) vs. 17.26 (± 3.65), p = 0.0343.

CONCLUSIONS

Compared with CIMV, NAVA appears to allow for more rapid weaning from invasive ventilation and decreases the incidence of bronchopulmonary dysplasia, especially in preterm infants with severe respiratory distress syndrome treated with surfactants.

The effects of exercise intensity on the cortisol response to a subsequent acute psychosocial stressor

OBJECTIVE

The aim of this experimental study was to determine the extent to which the intensity of a single 30 min bout of exercise alters the salivary cortisol (sCort) response to a subsequently induced acute psychosocial stressor. The study further aimed to elucidate a physiological mechanism through which exercise intensity exerts stress-mitigating effects.

METHODS

Eighty-three healthy men (M_age = 21.04 SD = 2.89) were randomly assigned to exercise on a treadmill at either 30%, 50% or 70% of their heart rate reserve (HRR) for 30 min and then underwent the Trier Social Stress Test 45 min later. sCort was measured repeatedly throughout and following the exercise bout and stressor task.

RESULTS

ANCOVA and Multilevel Growth Curve Analysis determined that vigorous (70% HRR) exercise elicited dampened sCort responses to the stressor task, marked by lower total sCort levels, diminished sCort reactivity, and faster recovery to baseline values, as compared to less intense exercise. Moreover, exercise elicited a sCort response in proportion to the intensity at which it was performed, and this exercise-associated HPA-axis response was inversely proportional to the sCort response to the subsequent stressor task.

CONCLUSIONS

This study revealed that exercise-intensity dampens the HPA-axis stress response in a dose-dependent manner, with evidence that the cortisol released from exercising intensely suppresses the subsequent cortisol response to a psychosocial stressor.

The role of ultrasonography for detecting tip location of percutaneous central venous catheters in neonates-a single-center, prospective cohort study

BACKGROUND

Percutaneous central venous catheters (PCVCs) are used commonly and widely in the neonatal intensive care unit (NICU). Malposition of PCVCs may cause life-threatening complications and prolong hospitalization. In Taiwan, conventional chest-abdomen radiography (CXR) has been used widely and routinely for assessing tip location of PCVCs. Compared to ultrasonography (US), CXR cannot provide real-time assessment, and patients are exposed to radiation. Therefore, this study aimed to analyze the role of US in detecting PCVC tip location in the lower extremities.

METHODS

Neonates who received PCVC insertion in the lower extremities in NICU from March 2019 to April 2020 were enrolled in this prospective cohort study. PCVC tip location was confirmed finally by conventional CXR after US examination and patients were included in the sono group; those not assessed by US formed the non-sono group. In addition, PCVCs inserted in 2018 for which tip location was evaluated only by CXR, were reviewed retrospectively and these cases were included in the non-sono group. Withdrawal rates between the two groups were analyzed using Chi-square test.

RESULTS

The sono group included 166 neonates with PCVCs and 141 were in the non-sono group. Median gestational age at date of PCVC insertion was 33.21 and 32.71 weeks in sono and non-sono groups, respectively (p = 0.37). Withdrawal rates were 10.84% and 65.95% (p < 0.001) and duration for catheter location confirmation were 2-4.75 min and 75-247.25 min (p < 0.001), respectively.

CONCLUSION

US provides more reliable images than conventional radiography alone for identifying PCVC tip locations in the lower extremities. It can effectively reduce catheter insertion duration, and was associated with fewer manipulations.

The equations of the inserted length of percutaneous central venous catheters on neonates in NICU

BACKGROUND

In neonatal intensive care units, a percutaneous central venous catheter (PCVC) is inserted peripherally and threaded into a central venous location, when intravenous access is anticipated for an extended period of time. The tip location of PCVCs should be checked by an X-ray after the procedure. The present study aimed to determine an equation to estimate the optimal insertion length of PCVCs in neonates prior to the procedure.

METHODS

The data of all neonates who had PCVC insertion between May 1st 2015 and April 30^th 2016 was reviewed. Their gender, body weight and body length at the insertion date, any complications and the tip culture of their PCVCs were recorded. The tip location of the PCVC, which was confirmed by X-ray, was either in the inferior vena cava near to the diaphragm or in the superior vena cava before the right atrial junction, depending on the insertion site. We analyzed the correlation among inserted length of PCVCs, body weight and body length by linear regression to determine an equation for estimating the optimal insertion length of PCVCs. The accuracy of the equations was evaluated prospectively by Pearson's correlation analysis, and the adjusting rate of PCVCs after the initial insertion was compared between the traditional method and using the equation.

RESULTS

The equation of PCVCs inserted in the foot was "insertion length (cm) = 16 + 4.27 × body weight (kg)", in the femoral vein was "inserted length (cm) = 9.8 + 1.7 × body weight (kg)", in the popliteal vein was "inserted length (cm) = -0.3 + 0.45 × body length (cm)", in the hand was "inserted length (cm) = 4.46 + 0.32 × body length (cm)", and in the axillary vein was inserted length (cm) = 1 + 0.18 × body length (cm). The adjusting rate of PCVCs after initial insertion was decreased from 73.5% to 53% following use of the equation.

CONCLUSIONS

Equations provided a convenient and accurate method to estimate the optimal insertion length of PCVCs before their placement.

Gestational age, not transient hyperthyrotropinemia impacts brain white matter diffusion tensor imaging in premature infants

Transient hypothyroidism is common in premature infants and increases the risk of adverse neurodevelopmental outcomes. Thyroid hormone (TH) is involved in oligodendrocyte development and myelination, however, whether transient hypothyroidism is associated with oligodendrocyte dysplasia and abnormal myelination is unclear. The aim of the present study was to investigate correlations among TH levels, neurodevelopmental outcomes and white matter (WM) microstructure in premature infants. The authors designed a cohort study recruiting 81 premature infants (age, 23-35 weeks). A total of 17 were born with a gestational age (GA) <30 weeks (early preterm group) and 64 of them were born with a GA ≥30 weeks (late preterm group). For outcome measurement, thyroid stimulating hormone (TSH) levels at 0, 18, and 24 h of admission were measured. Neurodevelopmental outcomes were assessed using Bayley III test. Diffusion tensor imaging was used to explore the characterization of WM microstructure. The data demonstrated that GA, however not TSH level was associated with neurodevelopmental outcomes in the following 2 years. Fractional anisotrophy (FA) increased with TSH0 levels over anterior limb of internal capsule, while axial diffusivity decreased with TSH0 levels over splenium of corpus callosum (CC). The late preterm group had more intact WM integrity over the internal and external capsule (EC) in FA compared with the early preterm group. Infants with motor dysfunction had significantly increased mean diffusivity (MD) values at regions of interest in the genu and splenium of CC. The results of the present study demonstrated that GA, however not transient hypothyroidism influenced neurodevelopmental outcomes in the premature infants. FA increased with age in a regionally-specific manner over regions of the internal capsule and EC. MD may act as a potential predictor for motor function in premature babies.

Detection in Malaysia of a Borrelia sp. From Haemaphysalis hystricis (Ixodida: Ixodidae)

Spirochetes from the Borrelia genus are known to cause diseases in humans, namely Lyme disease and relapsing fever. These organisms are commonly transmitted to humans by arthropod vectors including ticks, mite, and lice. Here, we report the molecular detection of a Borrelia sp. from a Haemaphysalis hystricis Supino tick collected from wildlife in an Orang Asli settlement in Selangor, Malaysia. Phylogenetic analyses of partial 16s rRNA and flaB gene sequences revealed that the Borrelia sp. is closely related to the relapsing fever group borreliae, Borrelia lonestari, Borrelia miyamotoi, and Borrelia theileri, as well as a number of uncharacterized Borrelia sp. from ticks in Portugal and Japan. To our knowledge, this is the first report of a Borrelia sp. detected in H. hystricis, and in Malaysia. The zoonotic potential of this Borrelia sp. merits further investigation.

Nasogastric Tube Placement and Esophageal Perforation in Extremely Low Birth Weight Infants

Perforation of the esophagus associated with placement of nasogastric tubes is not uncommon in preterm infants. Herein we report three cases of iatrogenic esophageal perforation associated with nasogastric tube placement. With nonsurgical management of parenteral nutrition and broad-spectrum antimicrobial therapy, all three neonates survived without sequelae. Effective strategies to prevent such complications are discussed.

Severe bronchopulmonary dysplasia is associated with higher fluid intake in very low-birth-weight infants: a retrospective study

OBJECTIVE

This study aims to investigate the association between fluid intake in the first 4 days of life and the subsequent severity of bronchopulmonary dysplasia (BPD) in very low-birth-weight infants (VLBWI).

STUDY DESIGN

A retrospective chart review of 75 infants with a gestational age of less than 32 weeks and a birth weight of < 1,500 g was performed. Demographic, clinical data, associated maternal risk factors, and amount of fluid received in the first 4 days of life were analyzed.

RESULTS

Severe BPD was associated with a lower gestational age (27.04 ± 2.073 wks vs. 28.70 ± 1.706 wks, p=0.001), lower birth weight (981.44 ± 244.54 vs. 1,199.63 ± 165.39 g, p < 0.001), use of surfactant (91.7 vs. 63%, p=0.002), patent ductus arteriousus (PDA) (70.8 vs. 37%, p=0.004), pulmonary hemorrhage (14.6 vs. 0%, p=0.045), and more fluids received from the 2nd to 4th days of life (346.44 ± 42.38 mL/kg vs. 323.91 ± 27.62 mL/kg, p=0.007). A cut off point of 345 mL/kg of fluids from the 2nd to 4th days of life was selected using receiver operating characteristic curve analysis, and remained a significant risk factor even after multiple logistic regression analysis.

CONCLUSION

Our findings demonstrate that VLBWI who received higher fluid intake from the 2nd to 4th days of life are at an increased risk of developing severe BPD.

High aspartate aminotransferase level predicts poor neurodevelopmental outcome in infants with meconium aspiration syndrome

OBJECTIVE

The aim of our study is to clarify the perinatal predictive factors of meconium aspiration syndrome (MAS) with neurodevelopmental delay (ND) in infants.

MATERIALS AND METHODS

In this retrospective study, data were collected from the infants born between 1990 and 2008. They all had primary diagnosis of MAS. Multivariable analyzed perinatal predictive factors of MAS with ND. The developmental status of these infants was followed at least 2 years with the Wechsler Intelligence Scale for Children.

RESULTS

A total of 114 surviving babies met the criteria of MAS. Six babies were defined as ND group. Lower 5-minute Apgar score and diastolic blood pressure were significantly related to the ND group. Elevated asparatate aminotransferase (AST), nucleated red blood cells, and white blood cells at the time of admission were significantly high in ND group. Furthermore, AST had area under the receiver operating characteristic curve of 0.879, (95% confidence interval: 0.801, 0.934), p < 0.0001. At 96 mg/dL, it had 83.33% sensitivity, 80.81% specificity, and negative predictive value of 98.8. Multivariable logistic regression analysis revealed AST was the only significant predictive factor for MAS with ND.

CONCLUSION

Early intervention should be recommended in infants having MAS with high AST level at birth for improving their neurodevelopmental outcomes.

Expressed breast milk for procedural pain in preterm neonates: a randomized, double-blind, placebo-controlled trial

AIM

To determine whether expressed breast milk (milk) reduces procedural pain associated with heel lancing in preterm neonates.

METHODS

In this placebo-controlled trial, preterm neonates received 5 mL of distilled water as placebo (water, n = 44), 25% glucose water (glucose, n = 39) or milk (n = 40). Heel lancing was performed 2 min later. The primary outcome was the duration of first cry after lancing.

RESULTS

Participants had similar baseline demographic and clinical characteristics. There was a significant difference in the median duration of first cry among the groups: water = 70.5 sec [interquartile range (IQR) = 5.5-104.5]; glucose = 2.0 sec (IQR = 0.0-45.0); milk = 29.5 sec (IQR = 0.0-65.0). Specifically, the duration of first cry was significantly shorter in the glucose group compared with the water group (Bonferroni adjustment, p = 0.011). Pain scores were significantly lower in the glucose and milk groups compared with the water group 1, 2 and 3 min after heel lancing (p < 0.05).

CONCLUSIONS

Although milk did not significantly reduce crying time, our finding that pain scores were significantly lower in the milk group suggests that milk may reduce pain associated with heel lancing in preterm neonates.

Incidence and result of treatment-demanding retinopathy of prematurity using revised U.S. screening guidelines

OBJECTIVE

To study the incidence of treated retinopathy of prematurity (ROP) using the revised U.S. screening guidelines, the rate of missed treatment, and unfavorable anatomic outcomes over a period of 2 years.

STUDY DESIGN

We reviewed the admission records of premature patients treated at our hospital from September 2008 to August 2010. Any baby born with a gestational age (GA) of less than 30 weeks or a birth body weight (BW) of less than 2000 g was included in this study. The ROP screening followed the revised U.S. screening guidelines as presented in 2006. The indications of treatment for ROP were threshold disease as defined by the Multicenter Trial of Cryotherapy for Retinopathy of Prematurity study and type 1 prethreshold ROP as defined by the Early Treatment for Retinopathy of Prematurity Randomized Trial study.

RESULTS

There were 385 infants who were examined for ROP screening during this period. Nineteen babies (35 eyes) fit the treatment criteria and received treatment. The incidence of treatment-demand ROP was 4.9% (19/385). Four babies had a birth BW >1500 g (4/19; 21%). Seventeen babies received treatment during their first admission and two babies received treatment during outpatient follow-up. No baby missed timely treatment. Three eyes progressed to stage 4/5 after receiving intravitreal bevacizumab treatment. The success rate after primary bevacizumab was 91% (30/33 eyes).

CONCLUSION

The incidence of treatment-demanding ROP using revised U.S. screening criteria was 4.9%. Teamwork and cooperation are very important to ensure that the highest-quality care possible is provided to patients in a timely manner.

Clinical presentation of children with gastroschisis and small for gestational age

BACKGROUND

Gastroschisis (GS) is defined as a full-thickness paraumbilical abdominal wall defect associated with evisceration of fetal abdominal organ. Although the concomitant nongastrointestinal anomalies and aneuploidy are rarely presented, fetal growth restriction is common. The aim of this study is to compare the primary and secondary outcomes of GS between infants small for gestational age (SGA) and those appropriate for gestational age as well as term and late preterm infants.

METHODS

Chart records of neonates born with gestational age at or more than 34 weeks were reviewed. All babies received repair procedure immediately after birth. SGA was defined as birth weight for gestational age below the 10th percentile. The primary outcomes were the length of hospital stay, duration of total parental nutrition used, and the surgical complications. The secondary outcome was the percentile of body weight at 6 months old.

RESULTS

There were 21 babies diagnosed with GS from January 1990 to January 2010 at Kaohsiung Chang Gung Memorial Hospital. Four (19%) babies expired soon after operation. Nine (53%) of the 17 surviving babies had SGA. Length of hospital stay, surgical complications, and the percentile of body weight at 6 months old were significantly poorer for the SGA compared with appropriate for gestational age group (p = 0.005, 0.050, and 0.035). Furthermore, preterm neonates in SGA group had lower Apgar scores at 1 minute and 5 minutes than did term neonates (p = 0.045 and 0.031).

CONCLUSION

SGA commonly occurred in GS cases and it was associated with longer hospital stay, more operative complications, and less body weight gain. Our conclusion may provide informative data to parents of GS fetuses during prenatal consultation, and reminds us that long-term follow-up of these cases could be necessary.

Clinical manifestations of symptomatic intracranial hemorrhage in term neonates: 18 years of experience in a medical center

BACKGROUND

Intracranial hemorrhage (ICH) is an uncommon but important cause of morbidity and mortality in term neonates. We conducted a retrospective analysis of the clinical characteristics and developmental outcomes of symptomatic ICH in term neonates.

METHODS

A retrospective chart review was conducted of all term neonates (less than 1 month old) diagnosed with ICH and admitted to the neonatal intensive care unit of Kaohsiung Chang Gung Hospital from December 1991 to December 2008. Demographic characteristics, mode of delivery, laboratory data, clinical presentation, and developmental status were recorded.

RESULTS

Data for 24 term neonates (17 boys and 7 girls) with a diagnosis of ICH were collected for analysis. The clinical manifestations of ICH included anemia (13/24, 54%), seizure (11/24, 46%), cyanosis (7/24, 29%), tachypnea (5/24, 21%), fever (1/24, 4%), hypothermia (1/24, 4%), and poor feeding (1/24, 4%). Age at symptom onset ranged from 2 hours to 11 days following birth. The most common type of ICH was subdural hemorrhage. All ICHs resolved, except in one infant, who died from hypoxicischemic encephalopathy at 25 days. Ten children with symptomatic ICH were reported to have normal development, while the remainder (13/23, 57%) showed developmental delays or disabilities.

CONCLUSION

Unexplained anemia, seizure, and cyanosis were the major presenting signs in infants with symptomatic ICH. A diagnosis of ICH should be considered in term neonates who present with one or more of these signs. Although the mortality in term infants with symptomatic ICH was low, more than half.

Replacing the rod with the cone transducin subunit decreases sensitivity and accelerates response decay

Cone vision is less sensitive than rod vision. Much of this difference can be attributed to the photoreceptors themselves, but the reason why the cones are less sensitive is still unknown. Recent recordings indicate that one important factor may be a difference in the rate of activation of cone transduction; that is, the rising phase of the cone response per bleached rhodopsin molecule (Rh*) has a smaller slope than the rising phase of the rod response per Rh*, perhaps because some step between Rh* and activation of the phosphodiesterase 6 (PDE6) effector molecule occurs with less gain. Since rods and cones have different G-protein alpha subunits, and since this subunit (Talpha) plays a key role both in the interaction of G-protein with Rh* and the activation of PDE6, we investigated the mechanism of the amplification difference by expressing cone Talpha in rod Talpha-knockout rods to produce so-called GNAT2C mice. We show that rods in GNAT2C mice have decreased sensitivity and a rate of activation half that of wild-type (WT) mouse rods. Furthermore, GNAT2C responses recover more rapidly than WT responses with kinetic parameters resembling those of native mouse cones. Our results show for the first time that part of the difference in sensitivity and response kinetics between rods and cones may be the result of a difference in the G-protein alpha subunit. They also indicate more generally that the molecular nature of G-protein alpha may play an important role in the kinetics of G-protein cascades for metabotropic receptors throughout the body.

Congenital diaphragmatic hernia in the neonatal period: review of 21 years' experience

BACKGROUND

Despite advances in therapeutic modalities, congenital diaphragmatic hernia (CDH) still accounts for significant neonatal mortality. This study aimed to describe the demographic features, clinical experiences of postnatal care, and differences between non-survivors and survivors with CDH.

METHODS

We retrospectively reviewed medical records of neonates with CDH admitted to Kaohsiung Chang Gung Memorial Hospital over a 21-year period. Neonates with diaphragmatic eventration and those transferred after surgery were excluded.

RESULTS

A total of 24 live-born neonates fulfilled the study criteria; 13 (54%) were boys and 11 (46%) were girls. Eight (33%) patients were prenatally diagnosed. The mean gestational age was 38.8 +/- 1.8 weeks (range, 35-41 weeks). Twenty-three (96%) had Bochdalek hernia [19 (83%) left-sided, 4 (17%) right-sided], and one (4%) had right-sided Morgagni hernia. Additional major congenital anomalies were identified in five patients (21%). The overall mortality was 21% (5/24); all deaths occurred before surgery. Statistically significant differences between survivors and non-survivors were found for right-sided CDH, low 1-minute and 5-minute Apgar scores, and low pH of the first arterial blood gas. Deaths were attributed to severe persistent pulmonary hypertension, unresponsiveness to aggressive resuscitation at birth, and major associated malformations.

CONCLUSION

Seventy-nine percent of our CDH patients survived to hospital discharge. Resuscitation by a skilled neonatology team to prevent low Apgar scores and low pH, careful evaluation of other anomalies, and overcoming pulmonary hypertension might improve the survival rate. Recognizing unfavorable factors in CDH may help clinicians manage the critical care of these babies.

Comparison of neonatal outcome for inborn and outborn very low-birthweight preterm infants

BACKGROUND

The aim of the present study was to compare the neonatal outcome of very low-birthweight (VLBW) preterm infants with regard to inborn and outborn status in a medical center of Southern Taiwan, where short-distance neonatal transport is the rule and maternal transport was not well established.

METHODS

This retrospective study included outborn VLBW preterm infants admitted to the neonatal intensive care unit of Chang Gung Memorial Hospital at Kaohsiung after neonatal transport during the period from 1999 through 2003. An equal number of inborn preterm infants matched for gender and birthweight were included as controls. Infants with lethal congenital anomalies or who died in the delivery room were excluded. Data were collected from reviewing medical charts.

RESULTS

A total of 34 inborn VLBW infants and 34 outborn VLBW infants with neonatal transport were included. Chronic lung disease (CLD) was significantly more frequent in the outborn group according to McNemar test (P = 0.0124) and logistic regression. Logistic regression also showed that outborn status (P = 0.0173) and birthweight (P = 0.0024) were the two most important risk factors for development of CLD.

CONCLUSION

Well-trained short distance neonatal transport is useful and valuable for VLBW infants with gestation age of 27-34 weeks in Southern Taiwan. The respiratory outcome, however, was poor in the outborn group in terms of incidence of CLD. To improve the respiratory outcome, further modification of respiratory care during transportation or antenatal maternal transport is crucial.

Neonatal group B streptococcal infection: a 7-year experience

BACKGROUND

This retrospective study was designed to determine the trend of neonatal group B streptococcal (GBS) infection during the past 7 years at the Chang Gung Memorial Hospital of Kaohsiung, as well as to assess the risk factors, clinical features and patient outcomes.

METHODS

Medical records of infants with neonatal GBS infection identified by positive results of cultures of sterile body fluid in our hospital from January 1996 through December 2002 were reviewed for demographic and clinical data.

RESULTS

There were 33 infants with neonatal GBS infections during the past 7 years in our hospital. The number of patients increased from 1996 to 2001. Sixteen infants had early onset infections and 17 infants had late onset infections. Of the nine patients with maternal risk factors in the early onset group, prolonged rupture of membranes (7, 44%) was most frequently encountered. Distressed respiratory sign (8, 50%) was the most common clinical presentation in early onset group, while fever >38 degrees C (17, 100%) was the most common presentation in late-onset group. The mortality rates were 13% and 6% in early and late onset groups, respectively. Gestational age (p = 0.05) and pneumonia (p = 0.015) were two most important factors influencing the mortality rate.

CONCLUSIONS

The number of GBS-infected infants seemed to have increased during the past 7 years in our hospital. Because the incidence of neonatal GBS infection and maternal colonization in Taiwan has not been collected, we could not determine the necessity of intrapartum chemoprophylaxis. Setting a comprehensive surveillance in Taiwan should be considered.

Fatal hemolytic transfusion reaction due to anti-Ku in a Knull patient

A fatal transfusion reaction due to anti-Ku in a Knull (Ko) patient is reported. The patient was transfused with 34 units of incompatible RBCs during 44 days of hospitalization. Apart from the first transfusion, all subsequent transfusions failed to raise the patient's Hb. No serum antibody was identified until he was transferred to another hospital for dialysis. A compatibility test demonstrated a weak antibody and autocontrol reacting at room temperature by a manual polybrene method. The antibody was considered to be a "cold agglutinin." A blood sample was sent to a reference laboratory where the patient was found to be Knull and the antibody was identified as anti-Ku.

Transient hypothyroxinemia of prematurity is associated with abnormal cranial ultrasound and illness severity

Transient hypothyroxinemia without elevated thyroid-stimulating hormone (TSH) levels is common in prematurity, especially in very-low-birth-weight (VLBW) infants. The transient hypothyroxinemia of prematurity (THOP) has been seen as a "benign" condition not requiring medical treatment. However, some recent large observational studies have revealed a relationship between THOP and abnormal neurodevelopment. Furthermore, one study showed THOP had twice the risk of brain echolucency, which was the best predictable neurodevelopmental dysfunction, than the premature infants with normal or higher thyroxine levels. The relationships among THOP, illness severity, and neurodevelopmental dysfunction remain unclear. We propose a hypothesis that THOP is associated with abnormal ultrasound and illness severity. We studied 54 infants who were admitted more than 14 days at our neonatal intensive care unit (NICU) with a birth weight <2000 g from March 1999 to March 2000. The infants received serum thyroxine (T4), free-T4, and TSH measurement during the first weeks of life. Most of them had serum thyroxine levels measured at approximately 2 weeks of age. The infants enrolled in the study were examined by at least 1 of 3 cranial ultrasounds during the first weeks of life, illness severity evaluation according to the neonatal therapeutic intervention scoring system (NTISS) score, as well as NICU hospital stay period. Infant were classified as THOP by T4 value <5.3 microg/dL (68 nmol/L), which is 2.6 SD below the mean for term infants in Massachusetts, without elevated TSH value (<20 microIU/mL). After adjusting for some confounding factors, such as gestational age, birth weight, duration of mechanical ventilation, infants with THOP were associated with abnormal cranial ultrasound, illness severity, and lower 1-minute Apgar score. In our studies, THOP was related with brain ultrasound anomaly, neonatal illness, and lower Apgar score at 1 minute. Does early thyroxine intervention improve the prognosis and neurodevelopmental dysfunction? This question requires further investigation.

Medial elbow problems in the overhead-throwing athlete

The elbow is subjected to enormous valgus stresses during the throwing motion, which places the overhead-throwing athlete at considerable risk for injury. Injuries involving the structures of the medial elbow occur in distinct patterns. Although acute injuries of the medial elbow can occur, the majority are overuse injuries as a result of the repetitive forces imparted to the elbow by throwing. Injury to the ulnar collateral ligament complex results in valgus instability. Valgus extension overload leads to diffuse osseous changes within the elbow joint and secondary posteromedial impingement. Overuse of the flexor-pronator musculature may result in medial epicondylitis and occasional muscle tears and ruptures. Ulnar neuropathy is a common finding that may be due to a variety of factors, including traction, friction, and compression of the ulnar nerve. Advances in nonoperative and operative treatment regimens specific to each injury pattern have resulted in the restoration of elbow function and the successful return of most injured overhead athletes to competitive activities. With further insight into the relevant anatomy, biomechanics, and pathophysiology involved in overhead activities and their associated injuries, significant contributions can continue to be made toward prevention and treatment of these injuries.

Efficacy of preoperative skin traction in hip fracture patients: a prospective, randomized study

OBJECTIVE

To compare the analgesic benefit of preoperative skin traction with the placement of a pillow under the injured extremity in patients with hip fractures.

DESIGN

Prospective, randomized clinical study.

SETTING

University-affiliated teaching institution.

PATIENTS AND PARTICIPANTS

One hundred consecutive patients with hip fractures admitted to the authors' institution who met inclusion criteria were enrolled. Fifty-five patients had femoral neck fractures, and forty-five patients had intertrochanteric fractures. The average patient age was seventy-eight years.

INTERVENTION

All patients were preoperatively randomized into two intervention groups. One group underwent placement of five pounds of skin traction on the injured extremity, whereas the second underwent placement of a pillow under the injured extremity. Fifty patients were enrolled in each intervention group.

RESULTS

With respect to immediate postintervention pain levels, patients treated with a pillow showed a trend toward better pain relief, as compared with patients treated with skin traction; however, this was not statistically significant. On the morning after admission, patients treated with a pillow had a statistically significant greater reduction in pain (p = 0.04). These patients also requested a statistically significant lower amount of pain medication (p < 0.01).

CONCLUSIONS

The authors think that preoperative skin traction in patients with hip fractures does not provide significant pain relief, as compared with pillow placement under the injured extremity, and thus should not be routinely performed in this patient population for analgesia.

Characterization of chicken antisera raised against Aspergillus spp. by enzyme linked immunosorbent assay

Enzyme linked immunosorbent assays of three Aspergillus species have been developed. Laying hens were immunized with the exoantigens from Asp. flavus, Asp. ochreaus and Asp. versicolor. All test chickens except for one produced antisera raised against the exoantigens. The antisera production process and ELISA titer were analysed. Fourteen days after the first injection, the antisera began to produce largely, on the 35th day reached to the peak, and maintained a stable level until the 42nd day. The maximum ELISA titer of the antisera to the exoantigens from Asp. flavus, Asp. ochreaus and Asp. versicolor was 1:8,000, 1:10,000 and 1:10,000, respectively. The cross-reactivities of antisera were determined with seventeen species of Aspergillus, ten species of fungi from other genera and the buffer-extracts of grain. The antisera did not cross-react with the exoantigens from other genera and the buffer-extracts of grain. The antiserum to exoantigen from Asp. ochreaus was species-specific, whereas the antisera against Asp. flavus and Asp. versicolor tended to cross-react with other Aspergillus species to varying degrees. The results suggest that exoantigens immunoassays can be developed to indentify and detect Aspergillus genus in grains.

[Experience of application of skin flap in repairing 112 patients with severe thermo pressure injury of hand]

OBJECTIVE

To investigate the clinical effect of skin flaps repairing severe thermopressure injury of hand.

METHODS

From January 1989 to December 1998, 112 patients with severe thermopressure injury of hand were repaired by various skin flaps transfer, the size of skin flaps was 6 cm x 8 cm to 12 cm x 18 cm. Postoperative patients were treated by combined rehabilitation in early stage.

RESULTS

All the flaps were survived with satisfactory effect. Sixty-six patients were followed up 6 to 12 months, skin flaps all showed better colour and texture, and function of the hand was satisfactory.

CONCLUSION

Different skin flaps are adopted to repair severe thermopressure injury of the hand according to different skin defects of the hand, combined early rehabilitation treatment, to achieve good recovery of function and appearance of the hand to the greatest extent.

In vitro and in vivo activation of polymorphonuclear leukocytes in response to particulate debris

The host inflammatory response to particulate wear debris has been implicated as a principal cause of osteolysis and aseptic loosening following total joint arthroplasty. While it has long been assumed that this inflammatory response is mediated solely by a chronic process, there has been evidence to suggest that an acute response to particulate debris may be important in initiating the chronic response. We studied the in vitro and in vivo acute inflammatory responses mediated by polymorphonuclear leukocytes (PMNs) to both retrieved particulate from a catastrophically failed uncemented metal-backed acetabular component and to commercially pure particulate (polyethylene, cobalt-chrome, and titanium). Isolated, nonactivated human PMNs in vitro exhibited both a dose- and time-dependent degranulation response to opsonized particulate debris, as evidenced by release of both specific (increased lysozyme activity) and azurophilic (increased beta-glucuronidase activity) granule contents. In the rat subcutaneous pouch model in vivo, PMNs were recruited within 3-6 h after exposure to particulate debris and were noted to phagocytize particulate and subsequently degranulate, as evidenced by increased beta-glucuronidase and PMN-specific myeloperoxidase (azurophilic granule enzymes) activities. This response peaked within the first 6 h and gradually declined by 24 h. The results of this study demonstrate the presence of an acute inflammatory response mediated by PMNs both in vitro and in vivo to particulate debris, which may be important in the sequence of events that lead to the macrophage-dominated chronic inflammatory process culminating in osteolysis and aseptic loosening of total joint arthroplasties.

Acute and chronic posterolateral rotatory instability of the knee

Isolated posterolateral rotatory instability of the knee is an uncommon injury pattern that may result in significant degrees of functional disability. This injury complex can be a challenging diagnostic and therapeutic problem for the orthopaedic surgeon. The presence of associated ligamentous and soft-tissue injuries, resulting in combined instability patterns, further complicates management. The results of recent research have enhanced our understanding of the complex anatomy and biomechanics of the posterolateral aspect of the knee. Numerous surgical techniques have been described for both repair and reconstruction of the injured posterolateral structures; however, long-term functional results have been only moderately successful.

Wear rates of ceramic-on-ceramic bearing surfaces in total hip implants: a 12-year follow-up study

A retrospective clinical and radiographic analysis was performed on 58 patients (60 hips; mean age at time of surgery, 45.2 years) at a minimum of 10-year follow-up (mean, 12.7 years) after total hip replacement using a ceramic-on-ceramic hearing total hip implant (Autophor, Smith and Nephew, Memphis, TN). Mean wear rate at final follow-up was 0.21 mim, averaging 0.016 mm/y. There were no cases of periprosthetic osteolysis in the acetabuulum or femur. For the unrevised components, there were 3 (5%) cases of protrusio acetabuli and 4 (7%) cases of acetabular component loosening. On the femoral side, 78.3% had distal pedestal formation, and 83% had greater than 2 mm implant-bone radiolucencies in more than 5 Gruen zones as a result of gross motion of the stem. Despite radiographic evidence of implant loosening, this hard bearing articulation functioned well in vivo for more than 12 years with remarkably low wear--approximately one tenth the rate reported for metal-on-polyethylene total hip bearings.

Effects of propofol on contractile response and electrophysiological properties in single guinea-pig ventricular myocyte

Effects of propofol on contractile response, action potential, resting membrane potential and L-type voltage-dependent calcium channel current were examined in guinea-pig single cardiac myocyte. Propofol (10(-4) M) inhibited contractile response induced by electrical stimulation (83.6% of control, n = 5), but did not change the resting membrane potential. On the other hand, propofol reduced the overshoot of action potential (10(-4) M), and shortened the duration of action potential (10(-5) and 10(-4) M). Whole-cell voltage clamp experiment showed inhibition of L-type calcium channel current (ICa, 10(-5) M: 90.8+/-1.39, 10(-4) M: 83.4+/-1.53% of control, n = 5). In addition, propofol showed use-dependent block of ICa. It is concluded that negative inotropic effect of propofol is caused by suppression of action potential, and that inhibition of ICa plays a role in shortening of the duration of action potential.

Repair of articular cartilage defects: part II. Treatment options

Articular cartilage injuries result in numerous clinical symptoms, such as pain and decreased functional levels. Current therapeutic options being used include articular surface debridement, such as chondral shaving, abrasion chondroplasty, and subchondral perforation; soft-tissue arthroplasties, such as perichondrial and periosteal grafts; and osteochondral transplantation. None of these therapies, however, has resulted in the successful regeneration of a hyaline-like tissue that withstands normal joint loading and activity over prolonged periods. As a result, research is also being conducted on alternative therapeutic procedures to enhance the repair process and to stimulate the regeneration of a repair tissue with hyaline-like structural and biologic properties. Part I of this paper, which was published in January, discussed the basic science of cartilage healing. Part II presents the treatment options.

Repair of articular cartilage defects: part I. Basic Science of cartilage healing

Articular cartilage injuries result in numerous clinical symptoms, such as pain and decreased functional levels. The limited reparative capabilities of hyaline cartilage results in the generation of repair tissue that lacks the structure and biomechanical properties of normal cartilage. Chondrocytes are unable to adequately proliferate, migrate, and synthesize high-quality repair tissue in response to blunt, superficial, or deep penetrating trauma. Extensive research has been conducted to understand the healing process and devise techniques that would enhance this response. Part I of this paper will discuss the basic science of cartilage repair. Part II, which will be published in the February issue, will present the treatment options.

Results of cemented metal-backed acetabular components: a 10-year-average follow-up study

The clinical and radiographic results of 86 primary total hip arthroplasties performed in 74 patients from 1983 to 1987 with a cemented metal-backed acetabular component and a cemented collared straight femoral stem with a 32-mm head were reviewed at a mean follow-up of 10.1 years. Seven patients (9.2%) underwent acetabular component revision at a mean of 9.0 years after implantation; an additional 24 components (31.6%) demonstrated evidence of radiographic loosening, resulting in a total failure rate of 40.8%. Periacetabular radiolucencies were noted in Charnley zones at the following rates: 34.2% in zone I, 18.4% in zone II, and 27.6% in zone III. In addition, 18.4% and 38.2% of implants demonstrated evidence of migration and excessive polyethylene wear. Excessively vertical cup placement (>49 degrees inclination) at the time of initial arthroplasty was statistically correlated with polyethylene wear, implant migration, and fixation failure. A trend of increasing implant failure was also noted with decreasing polyethylene liner thickness. Periacetabular cement mantle thickness was not statistically correlated with subsequent component loosening or failure. Results of Kaplan-Meier survivorship analysis using revision as an endpoint showed 93.6% survivorship at 10 years and 88.4% at 12 years. The mean modified Harris hip scores were 46.9 preoperatively and 81.8 at final follow-up. The significant overall rates of radiographic loosening, migration, polyethylene wear, and implant revision confirm the suspected trend of increasing failure rates of cemented metal-backed acetabular components over time.

On the mechanism by which 4-Aminopyridine occludes quinidine block of the cardiac K+ channel, hKv1.5

4-Aminopyridine (4-AP) binds to potassium channels at a site or sites in the inner mouth of the pore and is thought to prevent channel opening. The return of hKv1.5 off-gating charge upon repolarization is accelerated by 4-AP and it has been suggested that 4-AP blocks slow conformational rearrangements during late closed states that are necessary for channel opening. On the other hand, quinidine, an open channel blocker, slows the return or immobilizes off-gating charge only at opening potentials (>-25 mV). The aim of this study was to use quinidine as a probe of open channels to test the kinetic state of 4-AP-blocked channels. In the presence of 0.2-1 mM 4-AP, quinidine slowed charge return and caused partial charge immobilization, corresponding to an increase in the Kd of approximately 20-fold. Peak off-gating currents were reduced and decay was slowed approximately 2- to 2.5-fold at potentials negative to the threshold of channel activation and during depolarizations shorter than normally required for channel activation. This demonstrated access of quinidine to 4-AP-blocked channels, a lack of competition between the two drugs, and implied allosteric modulation of the quinidine binding site by 4-AP resident within the channel. Single channel recordings also showed that quinidine could modulate the 4-AP-induced closure of the channels, with the result that frequent channel reopenings were observed when both drugs were present. We propose that 4-AP-blocked channels exist in a partially open, nonconducting state that allows access to quinidine, even at more negative potentials and during shorter depolarizations than those required for channel activation.

The 1997 Stevenson Award Lecture. Cardiac K+ channel gating: cloned delayed rectifier mechanisms and drug modulation

K+ channels are ubiquitous membrane proteins, which have a central role in the control of cell excitability. In the heart, voltage-gated delayed rectifier K+ channels, like Kv1.5, determine repolarization and the cardiac action potential plateau duration. Here we review the broader properties of cloned voltage-gated K+ channels with specific reference to the hKv1.5 channel in heart. We discuss the basic structural components of K+ channels such as the pore, voltage sensor, and fast inactivation, all of which have been extensively studied. Slow, or C-type, inactivation and the structural features that control pore opening are less well understood, although recent studies have given new insight into these problems. Information about channel transitions that occur prior to opening is provided by gating currents, which reflect charge-carrying transitions between kinetic closed states. By studying modulation of the gating properties of K+ channels by cations and with drugs, we can make a more complete interpretation of the state dependence of drug and ion interactions with the channel. In this way we can uncover the detailed mechanisms of action of K+ channel blockers such as tetraethylammonium ions and 4-aminopyridine, and antiarrhythmic agents such as nifedipine and quinidine.

Allosteric effects of permeating cations on gating currents during K+ channel deactivation

K+ channel gating currents are usually measured in the absence of permeating ions, when a common feature of channel closing is a rising phase of off-gating current and slow subsequent decay. Current models of gating invoke a concerted rearrangement of subunits just before the open state to explain this very slow charge return from opening potentials. We have measured gating currents from the voltage-gated K+ channel, Kv1.5, highly overexpressed in human embryonic kidney cells. In the presence of permeating K+ or Cs+, we show, by comparison with data obtained in the absence of permeant ions, that there is a rapid return of charge after depolarizations. Measurement of off-gating currents on repolarization before and after K+ dialysis from cells allowed a comparison of off-gating current amplitudes and time course in the same cells. Parallel experiments utilizing the low permeability of Cs+ through Kv1.5 revealed similar rapid charge return during measurements of off-gating currents at ECs. Such effects could not be reproduced in a nonconducting mutant (W472F) of Kv1.5, in which, by definition, ion permeation was macroscopically absent. This preservation of a fast kinetic structure of off-gating currents on return from potentials at which channels open suggests an allosteric modulation by permeant cations. This may arise from a direct action on a slow step late in the activation pathway, or via a retardation in the rate of C-type inactivation. The activation energy barrier for K+ channel closing is reduced, which may be important during repetitive action potential spiking where ion channels characteristically undergo continuous cyclical activation and deactivation.

Expression of cartilage oligomeric matrix protein by human synovium

Human synovium was analyzed for the possible expression of cartilage oligomeric matrix protein (COMP). Immunostaining with polyclonal antiserum to COMP demonstrated positive staining within the synovial cells and immediately subjacent connective tissue, with less intense staining in the deeper connective tissue. Western blot analysis using either polyclonal or monoclonal antibodies to human COMP confirmed the presence of COMP by immunoreactive bands with the same molecular mass (approximately 110 kDa) as purified articular cartilage COMP. PCR using oligonucleotides that span human COMP exons 7-13 revealed identical amplification products from cDNA prepared from either human chondrocytes or synovium. Northern blot analysis using a biotinylated-probe to human COMP, spanning exons 12-13, also reveal an identical hybridization product to either human chondrocyte or synovium total RNA. Human synovium should be considered as a potential tissue source of COMP in any investigation of biological markers of cartilage metabolism.

Chondrocyte transplantation and experimental treatment options for articular cartilage defects

Current treatment options for injured articular cartilage have resulted in temporary improvements in clinical symptoms and functional levels. None of these modalities, however, has resulted in restoration of an articular surface that is able to withstand long-term joint loading and function. As a result, numerous investigators have attempted to devise alternative therapies. The limited regnerative potential of articular cartilage has led investigators to attempt using cells with the potential for differentiation and proliferation to repair chondral defects. Chondrocyte transplantation, both allogeneic and autogenous, has shown early promising results in regenrating hyaline-like tissue in both animals and humans. Encouraging results in animals have also been demonstrated with alternative sources of osteoprogenitor cells as grafts, as well as with natural/synthetic implants and the use of growth factors and cytokines. However, despite encouraging short-term results, long-term data concerning the regenerate tissue are still needed. As more research is being conducted to understand the processes of cartilage maintenance and healing, there is hope that cartilage regeneration and neochondrogenesis will be possible in the future.

Human carcinoembryonic antigen and biliary glycoprotein can serve as mouse hepatitis virus receptors

Receptors for murine coronavirus mouse hepatitis virus (MHV) are members of the murine carcinoembryonic antigen (CEA) gene family. Since MHV can also infect primates and cause central nervous system lesions (G. F. Cabirac et al., Microb. Pathog. 16:349-357, 1994; R. S. Murray et al., Virology 188:274-284, 1992), we examined whether human CEA-related molecules can be used by MHV as potential receptors. Transfection of plasmids expressing human carcinoembryonic antigen (hCEA) and human biliary glycoprotein into COS-7 cells, which lack a functional MHV receptor, conferred susceptibility to two MHV strains, A59 and MHV-2. Domain exchange experiments between human and murine CEA-related molecules identified the immunoglobulin-like loop I of hCEA as the region conferring the virus-binding specificity. This finding expands the potential MHV receptors to primate species.

[Clinical experience of laryngeal mask airway combined with continuous intravenous propofol infusion during general anesthesia]

BACKGROUND

Propofol's greatest attributes are its pharmacokinetic properties which result in a rapid, clear emergency and lack of cumulative effects even after prolonged administration. It is a drug of popular choice for the maintenance of general anesthesia. The laryngeal mask airway (LMA), originally described by Dr. Brain is now a good alternative as the airway management technique. Because of its high success rate in securing a clinically acceptable airway in anesthetized patients, LMA has been proposed as a practical airway and conveyer for general anesthesia. This study was designed to observe and evaluate the feasibility of propofol infusion combined with N2O for maintenance of anesthesia, with a LMA as airway and conveyer during general anesthesia.

METHODS

Sixty patients, ASA class I-II, aged 15-59 years, were selected for this study. They were scheduled for upper-limb orthopedic surgeries in supine position. No patient was premedicated. Intraoperative monitoring included electrocardiography, pulse oximetry, end-tidal carbon dioxide and automatic non-invasive blood pressure. The agents for induction of anesthesia included atropine 0.01 mg/kg, atracurium 5 mg, fentanyl 2-3 micrograms/kg, 2% lidocaine 1.5-2 mg/kg, propofol 2 mg/kg, and succinylcholine 1-1.5 mg/kg, all of which were given intravenously in sequence. After that laryngeal mask airway (LMA) was inserted. The position of LMA was confirmed by even undulation of chest wall and breathing sound. Anesthesia was then maintained with nitrous oxide in 40% oxygen and continuous propofol infusion. The pumping rate was set to start at 6 mg/kg/h. Muscle relaxation was achieved by intravenous tracrium given intermittently. All patients were mechanically ventilated with a ventilator incorporated to the anesthesia machine. The ventilator was set to give a tidal volume of 8 ml/kg at a rate of 12-14/min. At the end of the operation, the propofol infusion and nitrous oxide were simultaneously discontinued. The effect of muscle relaxant was antagonized by atropine 1.0 mg and neostigmine 2.5 mg intravenously. The LMA was removed while the patient was awake and able to open mouth at request. They were followed 24 h postoperatively for inquiring intraoperative awareness and other complaints.

RESULTS

No patient was noted to experience awareness during the intraoperative period. Regarding LMA insertion, success in the first attempt was seen in 55 patients (90.2%). Success in the second attempt was seen in 5 patients (8.2%). Failure was encountered in one patient (1.6%). The average time of emergence was 92 +/- 3.4 min. The average rate of speed of propofol infusion was 6.29 +/- 0.97 mg/kg/h.

CONCLUSIONS

The combination of propofol infusion and N2O with laryngeal mask as airway and recovery was a good alternative in administration of general anesthesia.

Anti-IgM-mediated regulation of c-myc and its possible relationship to apoptosis

Anti-IgM treatment of Burkitt's lymphoma cells is followed by either growth arrest or induction of apoptosis. In this study we have explored the role of c-myc in these events. Our results in Ramos cells indicate the following. (a) The decline in c-myc mRNA occurs at about 4 h; inhibition of about 80% being observed. (b) The stability of c-myc message is involved since the half-life of c-myc mRNA is decreased from about 30 min in untreated cells to about 15 min following treatment with anti-IgM. In the presence of cycloheximide, a protein synthesis inhibitor, the half-life is increased to about 50 min and was unaltered by treatment with anti-IgM. (c) By contrast, nuclear run-on experiments indicated no change in transcription rates for c-myc message due to treatment with anti-IgM. (d) A decrease in c-myc causes apoptosis since specific repression of c-myc with antisense oligonucleotides decreases the levels of c-Myc, inhibits growth rate, decreases viability, and induces apoptosis. (e) Anti-CD40 inhibition of apoptosis occurs without alteration in anti-IgM-induced down-regulation of c-myc mRNA, suggesting that it acts distally to c-myc down-regulation. Other cell lines were also investigated. In Epstein-Barr virus (EBV)-positive cell lines (Daudi, Raji, and Namalwa), anti-IgM treatment for 24 h results in growth inhibition without induction of apoptosis. In EBV-negative cell lines (ST486 and CA46, as well as Ramos), a more heterogeneous pattern of responses to anti-IgM are observed. Ramos and ST486 cells both show growth inhibition and apoptosis upon anti-IgM treatment; CA46 cells shown only growth inhibition but not apoptosis. Anti-IgM causes a decline in c-myc mRNA levels in all of these lines, as well as in c-Myc protein level in the two lines investigated, Daudi and Ramos, regardless of apoptosis. Addition of antisense c-myc oligonucleotides to the cells reduced growth in both Daudi and Ramos cells lines, however it resulted in substantial apoptosis only in Ramos cells. These results suggest that anti-IgM destabilizes c-myc mRNA by a process that involves mRNA turnover, rather than transcription rates. However anti-IgM exerts differential effects in EBV-positive and EBV-negative cell lines. EBV-positive cells are uniformly resistant to apoptosis, while EBV-negative cell lines show a tendency to apoptosis but with exceptions. Growth inhibition can be uncoupled from apoptosis in EBV-positive cell lines, but not in those EBV-negative cell lines prone to apoptosis. Furthermore, down-regulation of c-myc message correlates with growth inhibition in these cells, but is an insufficient link to apoptosis. By contrast inhibition of apoptosis by anti-CD40 occurs even though c-myc mRNA is decreased.

Slow gating charge immobilization in the human potassium channel Kv1.5 and its prevention by 4-aminopyridine

1. The relationship between ionic current inactivation and immobilization of 'off'-gating charge in human Kv1.5 channels expressed in human embryonic kidney (HEK293) cells was studied using 4-aminopyridine (4-AP) and tetraethylammonium chloride (TEA-Cl). 2. The charge transferred during short (< 10 ms) depolarizations (Q(on)) was conserved on repolarization (Q(off)) although peak off-gating current (off-Ig) was reduced and the time course prolonged (tau decay increased from 0.4 to > 1.2 ms). For +80 mV pulses longer than 50 ms, Q(off) at 20 ms was less than Q(on) (Q(off)/Q(on) ratio was 0.26 +/- 0.06 at 450 ms). We attribute this to a relative 'immobilization' of gating charge during long depolarizations. 3. 4-AP (0.1-1 mM) prevented slowing of off-Ig, allowing saturation of peak off-Ig. 4-AP also completely prevented immobilization of off-Ig after long depolarizations. In 1 mM 4-AP, off-Ig waveforms decayed rapidly and the charge ratio Q(off)/Q(on) remained at 1.0. 4. In addition to its effects on Ig, 1 mM 4-AP prevented the slow inactivation of ionic current seen during strong depolarizations. An initial block was caused by 4-AP or 1 mM intracellular TEA internally applied. However, only 4-AP prevented the slower, later development of C-type inactivation. 5. We suggest that slow current inactivation is accompanied by a gating charge immobilization in Kv1.5. 4-AP potently inhibits the changes in Q(off)/Q(on0, off-Ig, and ionic currents that underlie slow inactivation. Some actions of 4-AP appear independent of its properties as a blocker of open K+ channels, and are not mimicked by internal TEA.

TNF-alpha inhibits anti-IgM-mediated apoptosis in Ramos cells

We have examined the effects of tumor necrosis factor-alpha (TNF-alpha) as an inducer or modulator of necrosis and/or apoptosis in B cell lines. TNF-alpha does not induce either necrosis or apoptosis in EBV-positive or -negative cell lines, regardless of the culture conditions of the cells or the presence or absence of cytokines. By contrast anti-IgM induces apoptosis in two EBV-negative cell lines (Ramos and ST486) but not in EBV-positive cell lines. Since TNF receptor and CD40 belong to the TNF receptor superfamily and anti-CD40 is a known inhibitor of apoptosis, we tested for TNF-alpha's effects on the inhibition of apoptosis induced by anti-IgM. Our results indicate that TNF-alpha inhibits apoptosis induced by anti-IgM in Ramos cells but not in ST486. The effects are dose and time dependent; the degree of apoptosis achieved and the selectivity of the effect among cell lines are strikingly similar for both TNF-alpha and anti-CD40. Furthermore when both agents are tested together no additivity in the inhibition is observed. The inhibition of apoptosis is a direct effect of TNF-alpha and not a permissive effect of another cytokine, since it is observed in defined medium. Although anti-IgM induces both TNF-alpha secretion and TNF receptors in Ramos cells, the concentration of secreted TNF-alpha is too low to affect apoptosis. Inhibition does not involve perturbation of the cell cycle distribution of Ramos cells. Furthermore rapid induction of c-fos and the decrease in c-myc observed after anti-IgM treatment are both unaltered by TNF-alpha. Our results suggest that TNF-alpha is an inhibitor of apoptosis in Ramos cells, that its overall pattern of inhibition is similar to that of anti-CD40, and that both agents act at some point distal to the alteration of c-fos and c-myc by anti-IgM.

Synergy between signal transduction pathways is obligatory for expression of c-fos in B and T cell lines: implication for c-fos control via surface immunoglobulin and T cell antigen receptors

Expression of the protooncogene c-fos is controlled by three main regulatory pathways involving kinase C, cAMP, and calcium. Kinase C mediates its effects via phosphorylation of serum response factor (SRF) which interacts with the serum response element (SRE); cAMP and calcium mediate their effects via phosphorylation of CREB (cAMP regulatory element binding protein) presumably by activation of a protein kinase A or calmodulin-regulated kinase. We have examined the function of these elements in Burkitt's lymphoma cells (Ramos and Daudi) as well as a T lymphocytic cell line (Jurkat). We have found that stimulation of any one of these pathways alone has little or no effect on c-fos induction. However, kinase C activation (PMA stimulation) combined with either cAMP (forskolin plus MIX) or calcium stimulation (ionophore) leads to greatly enhanced c-fos induction. By contrast, cAMP in the presence of calcium shows no synergy in c-fos induction. Okadaic acid augments PMA- as well as calcium-mediated activation of c-fos, and has little or no effect when combined with cAMP. The main difference between Ramos (B cells) and Jurkat (T cells) in the regulation of c-fos is that cAMP plus calcium is strongly synergistic in Jurkat and is without effect in Ramos. Analysis of AP-1 activity using gel mobility shift assays confirms that the requirements for synergy in c-fos mRNA induction are paralleled by requirements for synergy in induction of AP-1 activity. Signaling in B cells due to anti-Ig stimulation involves both kinase C activation and release of intracellular calcium, and results in c-fos mRNA induction. Our results indicate that synergy between the kinase C activation and calcium is needed for efficient c-fos induction since neither of these two alone induces c-fos well. That synergy of signaling pathways is relevant for the anti-Ig induction of c-fos is supported by the fact that cAMP-inducing agents and okadaic acid further enhance anti-Ig induction of c-fos. These results suggest that cell-specific patterns of synergy are an essential feature for c-fos induction and may be relevant for c-fos control through B and T cell antigen receptors.

Regulation of low-density lipoprotein receptors and assessment of their functional role in Burkitt's lymphoma cells

The status of low-density lipoprotein receptors (LDLR) in Daudi Burkitt's lymphoma (BL) cells was examined using a flow cytometric assay employing the fluorescent ligand DiI-LDL, and a radioligand-binding assay using [125I]LDL. The binding is concentration-and time-dependent; and is specific, as judged by its competitive displacement in the presence of unlabeled LDL, and inhibition by heparin, EGTA, and 4 degrees C incubation. The regulation of the receptor and its functional role were then explored. Our results suggest the following: (a) In sharp contrast to normal peripheral blood lymphocytes, the LDLR levels in BL cells are basally elevated when cultured in fetal bovine serum (FBS) medium. (b) In accord with normal peripheral blood lymphocytes, incubation in lipoprotein-deficient serum (LPDS) medium further up-regulates the level of the receptor in BL cells, and co-incubation with LDL or 25-hydroxycholesterol down-regulates the receptor level. The magnitude of the up-regulation is significantly smaller than in normal peripheral blood lymphocytes. (c) Northern blots using a plasmid-DNA probe for LDLR mRNA point to a similar pattern for message regulation as is observed in direct binding studies. (d) Although the LDLR level is constitutively high in BL cells, availability of LDL, unlike transferrin, is not a growth requirement since incubation of cells in LPDS medium does not prevent proliferation of these cells. (e) In contrast to anti-transferrin receptor antibody which results in apoptosis upon binding, anti-LDLR antibody does not inhibit growth or induce apoptosis. Our results suggest LDLR is expressed at a significantly higher level in BL cells than in normal peripheral blood lymphocytes. Although up-regulation and down-regulation of LDLR are observed, this applies only to a small population of LDLR. The bulk receptor population is significantly resistant to down-regulation. Furthermore, notable differences in the functional role of the LDLR are found relative to the transferrin receptor which is also up-regulated in the BL cells.

Dimethyl sulfoxide suppresses apoptosis in Burkitt's lymphoma cells

Previous reports have suggested that dimethyl sulfoxide (DMSO) may be a useful reversible G1 arresting agent for synchronizing Raji Burkitt's lymphoma cells (K. Takase et al. (1992) Cell Growth Differ. 3, 515-521; M. Sawai et al. (1990) Exp. Cell Res. 187, 4-10). We have therefore critically evaluated several aspects of DMSO's effects using Daudi and Ramos Burkitt's lymphoma (BL) cells. In BL cells starved in the presence or absence of DMSO for 4 to 6 days (approximately four to six doubling times), the following observations were noted: (A) Both Daudi and Ramos cells show increased cell synchrony accompanied by apoptosis when starved in RPMI 1640 supplemented with 10% fetal calf serum (FCS). Inclusion of 1.5% DMSO causes a diminution in apoptosis with minimal effects on synchrony. (B) Lowering the FCS concentration to 5% induces apoptosis. DMSO-mediated protection from apoptosis is observed in Daudi but not in Ramos. (C) When human serum (10%) is used instead of FCS, Daudi cells show no apoptosis and DMSO is without effect on cell cycle distribution. By contrast, Ramos cells show significant apoptosis, which is prevented by the inclusion of DMSO. (D) When starved in a chemically defined medium (AIM-V), both Daudi and Ramos cells show significant apoptosis. DMSO protects Ramos from apoptosis under these conditions. (E) Upon removal of DMSO, both Daudi and Ramos cells reenter the cell cycle but with significant apoptosis. (F) The protective effect of DMSO from apoptosis is observed in a narrow range of concentration between 1 and 2%. At higher concentration, DMSO itself induces apoptosis. These results suggest that DMSO itself prevents apoptosis, an effect which may present as an apparent effect on cell synchrony.

Flow cytometric evaluation of LDL receptors using DiI-LDL uptake and its application to B and T lymphocytic cell lines

Low density lipoprotein receptors (LDL-R) on Daudi Burkitt's lymphoma (BL) cells were assessed using fluorescent DiI (3,3'-dioctadecylindocarbocyanine iodide)-LDL and flow cytometric analyses. Receptor-specific binding of DiI-LDL is followed by internalization of the bound complex and lysosomal hydrolysis of the ligand. Increase in the fluorescence intensity per cell is hence used as a measure of DiI-LDL uptake and, implicitly, as an indication of LDL-R presence. Our results show that uptake was observed in > 98% of the Daudi cells, and the level of uptake was significant and clearly distinguishable from autofluorescence, suggesting that: (a) this assay is comparable to the iodinated LDL uptake assay, although the ED50 values for the ligands are different; (b) this assay is comparable to the flow-cytometric detection of LDL-R using a commercial antibody directed against the receptor itself, and superior to a similar assay based on an antibody directed against membrane-bound LDL; (c) LDL uptake could be monitored along with transferrin uptake, suggesting that multiple endocytic receptor activities can be concurrently studied; (d) DiI-LDL uptake can be examined along with fluorescein-conjugated anti-CD10, -CD19, and -CD71, with little cross-interference, offering the added advantage that endocytic uptake and phenotyping can be simultaneously monitored; (e) the expression of LDL-R is intrinsically elevated in diverse cell lines such as Daudi, Raji, Ramos, Jurkat, and WIL2-NS, but not in normal lymphocytes. Our results therefore indicate that flow cytometric analysis of DiI-LDL uptake has potentially useful applications in the detection and study of endocytic receptor LDL-R in B and T lymphocytic cell lines.

A method for calculating the spinal-cord depth from an oblique simulator radiograph

An equation for calculating the spinal-cord depth from a simulator radiograph taken at an oblique angle has been derived. This equation is very useful when the cord cannot easily be identified on a horizontal lateral radiograph as in the case of the lower neck and upper thorax. To use this equation one needs to know the following parameters: the source-Axis-Distance, vertical source-skin-distance, the gantry angle at which the film was taken, and the target-film-distance.