Factors that Influence Placement of Gastrostomy Tube in Infants with Complex Congenital Heart Disease: A Single Center Study.

BACKGROUND: Factors that determine the need for Gastrostomy tube (G-tube) placement in infants with complex congenital heart defects (CHD) are variable. We aim to identify factors that improve counseling of expectant parents regarding postnatal outcomes and management. METHODS: We performed a retrospective review of medical record of infants with prenatal diagnoses of complex CHD between 2015-2019 in a single tertiary care center and assessed risk factors for G-tube placement with linear regression. RESULTS: Of the 105 eligible infants with complex CHD, 44 infants required G-tube (42%). No significant association was observed between G-tube placement and chromosomal abnormalities, cardiopulmonary bypass time or type of CHD. Median days on noninvasive ventilation (4 [IQR 2-12] vs. 3 [IQR 1-8], p = 0.035), time at which gavage-tube feeds were started postoperatively (3 [IQR 2-8] vs. 2 [IQR 0-4], p = 0.0013), time to reach full-volume gavage-tube feeds (6 [IQR 3-14] vs. 5 [IQR 0-8], p = 0.038) and intensive care unit (ICU) length of stay (LOS) (41 [IQR: 21 - 90] vs. 18 [IQR: 7 - 23], p < 0.01) were associated with G-tube placement. Infants with ICU LOS duration longer than median had almost 7 times the odds of requiring a G-tube (OR: 7.23, 95% CI: 2.71-19.32; by regression). CONCLUSIONS: Delay in initiation and in reaching full-volume gavage-tube feeds after cardiac surgery, increased number of days spent on non-invasive ventilation and in the ICU were found to be significant predictors for G-tube placement. The type of CHD and the need for cardiac surgery were not significant predictors for G-tube placement.

Surface energy characteristics of toner particles by automated inverse gas chromatography.

Inverse gas chromatography (IGC) was applied to the surface energy study of surfaces of toner particles. The dispersive component of the surface energy was determined for three toner materials by infinite dilution IGC. The values obtained were comparable to the values obtained from contact angle experiments. Previous adhesion experiments by atomic force microscopy suggested that the toner is a hydrophilic material with multiple adsorption energy sites. Both aspects were at least qualitatively confirmed by finite concentration IGC. Several indications for surface heterogeneity were found: (i) the difference between the dispersive component of the surface energy determined by IGC and the unexpectedly low total surface energy as determined by droplet analysis, (ii) the strong tailing behavior of the peaks of the injected polar probes, (iii) the decrease of the net retention volume with increasing n-pentane concentration, and finally (iv) the broad energy site distribution function with a dominant site at 28 kJ/mol, as determined by finite concentration IGC for n-pentane as molecular probe.

A comparison of neuropsychological tests for the assessment of chronic toxic encephalopathy.

BACKGROUND: From the viewpoint of the clinical neuropsychologist, it is not evident if the detection of solvent induced toxic encephalopathy (TE) could be optimized by a modification of the traditional test batteries, adding tests covering new dimensions or monitoring further functional domains. METHODS: To clarify this issue, TE patients were re-examined with (a) the tests traditionally used in screening for TE and (b) some tests hitherto less utilized within neurotoxicology, involving complex attention and frontal lobe functioning. RESULTS: The results do not indicate that tests of the latter category would be more sensitive to TE than the tests traditionally used. Using an optimized core battery, compiled of tests from both categories, the sensitivity and specificity levels reached a maximum of around 0.7 when using as criterion the reproduction of a subnormal test profile (TE type 2B). CONCLUSIONS: A combination of several traditional and a few newer tests is suggested to optimize the detection of TE. Repeated assessments over time are also recommended.

Psychological test performance during experimental challenge to toluene and n-butyl acetate in cases of solvent-induced toxic encephalopathy.

OBJECTIVES: This study determined whether performance in neurobehavioral tests deteriorates during subjectively annoying chemical challenge below known neurotoxic thresholds among persons with toxic encephalopathy with subjective hypersensitivity to chemicals. METHODS: Subjects with symptoms and previous neuropsychological test results compatible with toxic encephalopathy (TE) of either type 2A (N=12) or 2B (N=12) and unexposed referents (N=12) were challenged in an exposure chamber. In a counterbalanced design, the subjects were exposed on 2 occasions to increasing air concentrations of n-butyl acetate and toluene at levels well below the thresholds for neurotoxic effects. Attention and motor speed tests were given (i) in room air outside the chamber before the challenge, (ii) in room air inside the chamber before the exposure, (iii) at 12 ppm (44 or 56 mg/m3), and (iv) at 48 ppm (at 180 or 228 mg/m3). RESULTS: For both substances the TE groups showed a slight increase (deterioration) in the simple reaction-time task during chemical exposure, but not in the complex reaction-time task or in the digit symbol test of the Wechsler Adult Intelligence Scale. Contrary to reference subjects, the TE subjects did not show any improvement or learning effect in the digit symbol test over the chamber phases. n-Butyl acetate tended to affect cognitive functioning more obviously than toluene did. Suggestion or expectancy effects were not observed in any group in the clean-air baseline conditions. CONCLUSIONS: The results do not support the notion that men with subjective hypersensitivity to chemicals would be more affected than healthy men regarding cognitive functioning during annoying solvent exposure below thresholds for acute neurotoxic effects.

Stress management in men with solvent-induced chronic toxic encephalopathy.

Stress management was studied in male patients with solvent-induced chronic toxic encephalopathy (TE) of types 2A (TE 2A, n = 31) and 2B (TE 2B, n = 26). The patients were compared with a healthy reference group (n = 57). Self-reported symptoms (90-item Symptoms Checklist [SCL-90]), sense of coherence, coping strategies, and level of mastery were measured. As expected, both TE groups reported highly deviating symptoms on most SCL-90 scales. The TE 2B patients, who had objectified cognitive dysfunction, reported more use of passive, less situationally adequate coping strategies; a weaker sense of coherence; and a lower degree of mastery. In contrast, the TE 2A cases showed only minor deviations from the reference group in these respects. The results suggest that having a strong sense of coherence, a sense of mastery, and flexible resources for stress management could be dependent on intact brain functions.

Suprathreshold intensity and annoyance reactions in experimental challenge to toluene and n-butyl acetate among subjects with long-term solvent exposure.

OBJECTIVES: This study explores reactions to low-level chemical challenge, aiming at the development of test procedures for assessing individual sensitivity to smells and chemicals. METHODS: Subjects with symptoms and neuropsychological test results compatible with toxic encephalopathy type 2A (TE-2A) and 2B (TE-2B) and unexposed referents (N=12 in each group) were challenged in an exposure chamber. Toluene exposure was started at 11 mg/m3, and it followed a geometric progression scale with a ratio of 2, until reaching 180 mg/m3. In a counterbalanced design, the subjects were similarly exposed to n-butyl acetate starting at a concentration of 14 mg/m3 and increasing to 228 mg/m3. At each exposure level, smell intensity was measured on a 7-step category scale. Mucous membrane irritation and annoyance reactions were rated on visual analogue scales. RESULTS: Both TE groups showed high sensitivity to the low-level solvent challenge, which provoked immediate annoyance and fatigue reactions. In particular the TE-2B group related smell intensity to various annoyance dimensions during exposure to n-butyl acetate, a pattern not observed during toluene exposure. The reference group clearly separated smell intensity and annoyance reactions in both exposure conditions. CONCLUSIONS: The reaction of the TE cases suggests that chemical sensitivity can be distinguished from normal annoyance reactions by the inability to differentiate between smell intensity and an experience of irritation from mucous membranes in air concentrations well below the trigeminal irritation threshold level. Fatigue coreactivity in challenges to single substances below the neurotoxic level may also be important.

Long-term follow-up of psychological distress, social functioning, and coping style in treated and untreated patients with solvent-induced chronic toxic encephalopathy.

Patients with organic solvent-induced toxic encephalopathy (TE) (n = 13) were followed up seven years after the application of an intervention program. They were also compared with untreated TE patients diagnosed at the same time (n = 26) and with unexposed referents (n = 39). Psychological distress, social function, and coping ability and style were measured with the Symptom Checklist-90, Interview Schedule of Social Interaction, and Sense of Coherence and Strategies to Handle Stress questionnaires. Both TE groups had unchanged function in neuropsychological tests. Members of the treated group had improved their social functioning and reduced their mental stress but were not any better than the untreated patients. Compared with referents, the TE patients continued to live with increased psychological distress and used predominantly emotionally focused strategies to cope with their problems. This can be a cause for concern in family life and can also make gainful work impossible.

Adrenalectomy after weaning restores beta3-adrenergic receptor expression in white adipocytes from C57BL/6J-ob/ob mice.

The role of hypercorticism in the development of compromised beta-adrenergic signaling in adipose tissue was assessed in ob/ob mice adrenalectomized at 4 weeks of age and studied 1 and 3 weeks thereafter. Adrenalectomy prevented the rapid increase in body weight and fat deposition between 4 and 5 weeks of age in ob/ob mice and produced a phenotype indistinguishable from that of lean mice. However, adrenalectomized ob/ob mice became intermediate between lean and ob/ob mice by 7 weeks of age. Adipocyte beta3-adrenergic receptor (AR) messenger RNA levels were similar between lean and adrenalectomized ob/ob mice at both time points and were 4- to 8-fold higher than messenger RNA levels in ob/ob mice. As judged by maximal activation of adenylyl cyclase by a beta3-AR-selective agonist, adrenalectomy also restored functional activity of the beta3-AR to levels above or equivalent to those seen in lean mice at both time points. The present results suggest that development of hypercorticism at or before weaning in ob/ob mice represses expression of the beta3-AR and prevents the normal postweaning development of this signaling system in the adipocyte.

The effect of task complexity on reaction times in memory scanning and visual discrimination in Parkinson's disease.

Within the context of the bradyphrenia debate, two experiments designed to measure the cognitive speed of Parkinson patients (PD) were conducted with 58 subjects. The experiments took the form of a high-speed memory scanning task using memory sets consisting of one-six words or one-six abstract figures. In a visual discrimination task, two simultaneously presented abstract images had to be compared, the complexity of the images being varied through four stages. Motor response was constant, reaction time was the dependent variable. PD differed from matched controls in the level (significant only in scanning) but in neither experiment in the slope of reaction time curves. Interaction group x complexity (MANOVA) was not significant. Correlations between disease parameters and a 'complexity effect' measure were low throughout. However, the link to general intelligence was significant. The findings contradict the conventional bradyphrenia hypothesis.

Alterations in mRNA levels, expression, and function of GTP-binding regulatory proteins in adipocytes from obese mice (C57BL/6J-ob/ob).

Messenger RNA levels for the alpha subunit of G-proteins expressed in adipocytes of lean and obese (ob/ob) mice were compared with relative levels of the encoded proteins. Using both toxin labeling and Western blots, expression of Gs alpha, Gi alpha-1, and Gi alpha-3 was decreased by approximately 2-fold in adipocytes of obese mice, while levels of Gi alpha-2 did not differ between the phenotypes. The decreases in Gi alpha-1 and Gs alpha in the obese mouse were attributed to decreased mRNA levels for these proteins. Similar mRNA levels for Gi alpha-3 were noted in both phenotypes, but Gi alpha-2 message was increased 2-fold in the obese mouse. Inhibitory regulation of adipocyte adenylylcyclase through G-proteins was evaluated by comparing the ability of R-PIA to inhibit isoproterenol-stimulated responses between the phenotypes. In spite of the decrease in Gi alpha-1 and Gi alpha-3 in adipocytes from obese mice, R-PIA inhibited adenylylcyclase, cAMP-dependent protein kinase, and lipolysis in similar fashion in both phenotypes. The GTP analog, Gpp(NH)p also inhibited forskolin-stimulated adenylylcyclase in a comparable manner, but the magnitude of the inhibition was slightly less in adipocyte membranes from obese mice. In contrast, the decrease in expression of Gs alpha was translated into substantially poorer activation of isoproterenol-stimulated responses in the obese mouse. The concentration of isoproterenol producing half-maximal activation of adenylylcyclase, protein kinase, and lipolysis did not differ between the phenotypes, but the maximal responses were much lower in cells from obese mice. Similar lipolytic potential in isolated adipocytes from each phenotype and similar total forskolin-stimulated cyclase activity in adipocyte membranes from each phenotype suggest that decreased expression of Gs alpha may contribute to the characteristic alteration in mobilization of triglycerides noted in adipocytes from obese mice.

The acute effects of uvulopalatopharyngoplasty on breathing during sleep in sleep apnea patients.

Uvulopalatopharyngoplasty (UPPP) is frequently employed in the treatment of obstructive sleep apnea (OSA). Despite anecdotal reports of early post-UPPP deaths and the recommendation by some authors to perform a prophylactic tracheotomy for selected patients at the time of UPPP, there has been no systematic examination of breathing during sleep in the early post-UPPP period. In order to evaluate the early postoperative risk and the need for prophylactic tracheotomy in UPPP patients, we conducted polysomnograms (PSGs) on eight obese OSA patients on the second post-UPPP night and on another obese OSA patient on the fifth night after surgery. Postoperatively during wakefulness there was a significant increase in the alveolar-arterial oxygen gradient (p less than 0.05); in three individuals, the PaO2 was sufficiently reduced to warrant supplemental oxygen. For the group of nine patients there were no differences between the pre- and post-UPPP apnea index (AI), hypopnea index (HI), or apnea plus hypopnea index during non-rapid eye movement sleep. In individual patients, the pattern of sleep-disordered breathing events was variably altered, but there was a reciprocal relationship between the changes in AI and HI (r = 0.75; p less than 0.02). The duration of apnea in non-rapid eye movement sleep was shorter in four patients and unchanged in five patients postoperatively. Although the mean nadir of hemoglobin saturation was unchanged before and after UPPP, one patient desaturated to dramatically low levels in association with several excessively prolonged apneas post-UPPP. Desaturation was probably minimized in the three patients receiving supplemental oxygen. There were no serious adverse effects resulting directly from sleep-disordered breathing or nocturnal hemoglobin oxygen desaturation following UPPP. Our data suggest that performing a tracheotomy in a nonselective fashion in OSA patients undergoing UPPP is not warranted. In lieu of this, these individuals should be carefully monitored following surgery. In addition, patients with severe OSA and/or moderate-to-severe nocturnal hemoglobin oxygen desaturation should be considered for early postoperative PSGs as should those individuals who are more hypoxemic while awake following surgery. Patients who require supplemental oxygen postoperatively should also be studied to ensure adequate oxygenation and to monitor for acute, oxygen-related prolongation of apnea.