Assessing neonatal heat balance and physiological strain in newborn infants nursed under radiant warmers in intensive care with fentanyl sedation.

PURPOSE: To assess heat balance status of newborn infants nursed under radiant warmers (RWs) during intensive care. METHODS: Heat balance, thermal status and primary indicators of physiological strain were concurrently measured in 14 newborns nursed under RWs for 105 min. Metabolic heat production (M), evaporative heat loss (E), convective (C) and conductive heat flow (K), rectal temperature (T re) and mean skin temperatures (T sk) were measured continuously. The rate of radiant heat required for heat balance (R req) and the rate of radiant heat provided (R prov) were derived. The rate of body heat storage (S) was calculated using a two-compartment model of 'core' (T re) and 'shell' (T sk) temperatures. RESULTS: Mean M, E, C and K were 10.5 ± 2.7 W, 5.8 ± 1.1 W, 6.2 ± 0.8 W and 0.1 ± 0.1 W, respectively. Mean R prov (1.7 ± 2.6 W) and R req (1.7 ± 2.7 W) were similar (p > 0.05). However, while the resultant mean change in body heat content after 105 min was negligible (-0.1 ± 3.7 kJ), acute time-dependent changes in S were evidenced by a mean positive heat storage component of +6.4 ± 2.6 kJ and a mean negative heat storage component of -6.5 ± 3.7 kJ. Accordingly, large fluctuations in both T re and T sk occurred that were actively induced by changes in RW output. Nonetheless, no active physiological responses (heart rate, breathing frequency and mean arterial pressure) to these bouts of heating and cooling were observed. CONCLUSIONS: RWs maintain net heat balance over a prolonged period, but actively induce acute bouts of heat imbalance that cause rapid changes in T re and T sk. Transient bouts of heat storage do not exacerbate physiological strain, but could in the longer term.

Skin temperature over the carotid artery provides an accurate noninvasive estimation of core temperature in infants and young children during general anesthesia.

BACKGROUND: The accurate measurement of core temperature is an essential aspect of intraoperative management in children. Invasive measurement sites are accurate but carry some health risks and cannot be used in certain patients. An accurate form of noninvasive thermometry is therefore needed. Our aim was to develop, and subsequently validate, separate models for estimating core temperature using different skin temperatures with an individualized correction factor. METHODS: Forty-eight pediatric patients (0-36 months) undergoing elective surgery were separated into a modeling group (MG, n = 28) and validation group (VG, n = 20). Skin temperature was measured over the carotid artery (Tsk_carotid ), upper abdomen (Tsk_abd ), and axilla (Tsk_axilla ), while nasopharyngeal temperature (Tnaso ) was measured as a reference. RESULTS: In the MG, derived models for estimating Tnaso were: Tsk_carotid  + 0.52; Tsk_abd  + (0.076[body mass] + 0.02); and Tsk_axilla  + (0.081[body mass]-0.66). After adjusting raw Tsk_carotid, Tsk_abd , and Tsk_axilla values in the independent VG using these models, the mean bias (Predicted Tnaso - Actual Tnaso [with 95% confidence intervals]) was +0.03[+0.53, -0.50]°C, -0.05[+1.02, -1.07]°C, and -0.06[+1.21, -1.28°C], respectively. The percentage of values within ±0.5°C of Tnaso was 93.2%, 75.4%, and 66.1% for Tsk_carotid, Tsk_abd , and Tsk_axilla , respectively. Sensitivity and specificity for detecting hypothermia (Tnaso  < 36.0°C) was 0.88 and 0.91 for Tsk_carotid , 0.61 and 0.76 for Tsk_abd , and 0.91 and 0.73 for Tsk_axilla . Goodness-of-fit (R(2) ) relative to the line-of-identity was 0.74 (Tsk_carotid ), 0.34 (Tsk_abd ), and 0.15 (Tsk_axilla ). CONCLUSIONS: Skin temperature over the carotid artery, with a simple correction factor of +0.52°C, provides a viable noninvasive estimate of Tnaso in young children during elective surgery with a general anesthetic.

Infantile myofibromas obstructing opposite ends of the gastrointestinal tract.

Myofibromas are benign congenital tumors of soft tissue that can present at birth or during infancy in solitary or multicentric forms. Visceral myofibromas are rarely reported, but are typically symptomatic due to involvement of vital structures. We present two cases of congenital myofibromas, one obstructing the proximal esophagus and the other obstructing the distal rectum. Lessons learned from the treatment of these two patients are shared and the pertinent literature is reviewed.

Café-au-lait macules and pediatric malignancy caused by biallelic mutations in the DNA mismatch repair (MMR) gene PMS2.

A 14-year-old male presented with a T4 sigmoid adenocarcinoma, <10 colonic adenomas and multiple café-au-lait macules. Family history was not suggestive of a dominant hereditary form of colorectal cancer. Evaluation of the tumor revealed abnormal immunohistochemical staining of the PMS2 protein and high frequency microsatellite instability. Germline analysis identified biallelic PMS2 missense mutations. A new cancer syndrome caused by biallelic mutations in the mismatch repair genes, including PMS2, is now emerging and is characterized by café-au-lait macules, colonic polyps and a distinctive tumor spectrum.

Feingold syndome: a rare but important cause of syndromic tracheoesophageal fistula.

Esophageal atresia (EA) and tracheoesophageal fistula (TEF) are common congenital malformations and are associated with additional anomalies in approximately half of cases. Feingold syndrome is an important genetic cause of syndromic EA-TEF to consider in patients with associated microcephaly and digital anomalies. We present a case report of a male infant with EA-TEF, microcephaly, subtle facial dysmorphism, dysplastic kidney, short fifth fingers, second finger clinodactyly, and increased spacing between the first and second toes bilaterally. His clinical presentation was suggestive of Feingold syndrome, and genetic testing of the MYCN gene confirmed the diagnosis. Feingold syndrome is an autosomal dominant condition, and therefore, the diagnosis has important implications for genetic counseling.

Wilms' tumor at the Children's Hospital of Eastern Ontario: 1990-2001.

BACKGROUND: Wilms' Tumor is the most common malignant neoplasm of the urinary tract in children. Since 1969, the National Wilms' Tumor Study Group (NWTSG) has contributed to improving the clinical management and outcome of children affected by Wilms' Tumor. We have managed our patients according to NWTSG protocols and report our results herein. METHODS: Retrospective chart review of consecutive patients presenting at the Children's Hospital of Eastern Ontario (CHEO) with a diagnosis of Wilms' Tumor between April 1990 and March 2001. RESULTS: Forty patients with Wilms' Tumor (18 M/22 F) were diagnosed at CHEO during this interval. Mean age at diagnosis was 28.5 months. The most common presenting feature was a palpable abdominal mass in 85%. An overgrowth syndrome was noted in 10%. Metastatic disease was present at diagnosis in 20%, with the lungs (75%) the most common site of involvement. Distribution of clinical stage: I = 40%, II = 20%, III = 20%, IV = 15%, V = 5%. Favorable histology (FH) was diagnosed in 82.5%, anaplasia in 12.5% and clear cell sarcoma (CCSK) in 5%. Nephrogenic rests were present in 43% (perilobar (PL) = 20%, intralobar (IL) = 18%, PL + IL = 5%). Recurrence of disease occurred in 10%, with lungs (100%) the most frequent site of relapse. Survival was significantly greater in stage I disease and in those patients with FH. Patient 4-year survival data: stage I (FH), 100%; stage II (FH), 80%; stage III (FH), 100%, stage IV (FH), 67%; stages I-IV (CCSK), 100%; stage V, 0%. Overall 4-year survival rates of patients with FH were 92% and of all patients in the study was 86%. CONCLUSIONS: The presentation of Wilms' Tumor at our institution mirrors that described in the literature. Importantly, by following NWTSG protocols we have achieved an outcome of overall 4-year patient survival comparable to the "gold standard". This demonstrates the utility of the NWTSG protocols as regards patient management of this relatively uncommon disease.

Kinetics and apparent activation energy of the reaction of the fluorogenic reagent 5-furoylquinoline-3-carboxaldehyde with ovalbumin.

Incomplete labeling of proteins by a derivatizing reagent usually results in the formation of a large number of products, which can produce unacceptable band broadening during electrophoretic analysis. In this paper, we report on the reaction of the fluorogenic reagent 5-furoylquinoline-3-carboxaldehyde (FQ) with the lysine residues of ovalbumin. Mass spectrometry was first used to determine the distribution in the number of labels attached to the protein. At room temperature, 3.6+/-1.9 labels were attached after 30 min. The reaction rate and number of labels increased at elevated temperatures. At 65 degrees C, 6+/-2.5 labels were attached after 5 min. The apparent activation energy for this reaction is estimated as 48+/-17 kJ/mol. Based on the mass spectrometry study, the labeling reaction was assumed to consist of two steps. In the first, the protein unfolds to make lysine residues accessible. In the second, the reagents react with the epsilon -amine of the lysine residues. To test this hypothesis, submicellar capillary electrophoresis and laser-induced fluorescence were used to characterize the reaction mixture. The apparent activation energy was measured for the labeling reaction; the apparent activation energy was 57+/-12 kJ/mol for reaction performed in the separation buffer. Denaturing agents were added to the reaction mixture. The addition of 2 M thiourea with 6 M urea to the reaction resulted in a modest decrease in the apparent activation energy to 42+/-2 kJ/mol. The addition of 2.5 M or higher concentration of ethanol decreased the apparent activation energy to 32+/-2 kJ/mol. We conclude that the apparent activation energy for protein labeling is dominated by denaturation of the protein, and that the addition of suitable denaturing reagents can eliminate this contribution to the reaction chemistry.