Comparison of sulfolane effects in Sprague Dawley rats, B6C3F1/N mice, and Hartley guinea pigs after 28 days of exposure via oral gavage.

Sulfolane is a solvent used in industrial refining with identified environmental exposure in drinking water. Due to potential large species differences, the National Toxicology Program (NTP) conducted 28-day toxicity studies in male and female Hsd:Sprague Dawley® SD® rats, B6C3F1/N mice, and Hartley guinea pigs. A wide dose range of 0, 1, 10, 30, 100, 300, and 800 mg/kg was administered via gavage. Histopathology, clinical pathology, and organ weights were evaluated after 28 days of exposure. In addition, plasma concentrations of sulfolane were evaluated 2 and 24 h after the last dose. Increased mortality was observed in the highest dose group of guinea pigs and mice while decreased body weight was observed in rats compared to controls. Histopathological lesions were observed in the kidney (male rat), stomach (male mice), esophagus (male and female guinea pigs), and nose (male guinea pigs). Plasma concentrations were generally higher in rats and guinea pigs compared to mice with evidence of saturated clearance at higher doses. Male rats appear to be the most sensitive with hyaline droplet accumulation occurring at all doses, although the human relevance of this finding is questionable.

Alteration in hypoplasia of the hindfoot structures during early growth in clubfeet treated using the Ponseti method.

PURPOSE: Previous reports have demonstrated diminished size of the hindfoot bones in patients with idiopathic clubfoot deformity. However, no study has quantified the percentage of hypoplasia as a function of early growth, during the brace phase of Ponseti treatment. METHODS: We measured the dimensions of ossified structures on radiographs in patients with unilateral Ponseti-treated clubfeet to determine changes in the percentage of hypoplasia between two and four years of age. RESULTS: The degree of hypoplasia varied among the osseous structures in Ponseti-treated clubfeet at age two years, with greater hypoplasia being observed in the talus (7.3%), followed by calcaneus (4.9%) and the cuboid (4.8%). Overall, the degree of hypoplasia diminished by four years, such that the degree of hypoplasia was greatest in the talus (4.2%) and the calcaneus (4.2%) followed by the cuboid (0.6%). At four years of age, the greatest degree of hypoplasia persisted in the talus and calcaneus. CONCLUSIONS: Changes occurred in the size of the ossification of hindfoot bones between two and four years of age, and the observed changes in the percentage of hypoplasia varied among the different structures. At four years of age, the greatest percentage of hypoplasia was observed in the talus and calcaneus at values similar to those previously reported in skeletally mature patients. The results suggested that the relative difference in size of the feet may be expected to remain constant in a child with a unilateral clubfoot after this age.

Surgical repair of an atrial septal defect in a juvenile Sumatran orangutan (Pongo pygmaeus sumatraensis).

A systolic heart murmur was auscultated in a 2-yr-old female Sumatran orangutan (Pongo pygmaeus sumatraensis) with a slower than expected growth rate. Cardiac ultrasound revealed an 11-mm atrial septal defect. Cardiac catheterization confirmed the diagnosis. Surgical repair was performed during cardiopulmonary bypass using a pericardial patch. The bypass pump was primed with human albumin and donor orangutan whole blood of a compatible type. Hematuria occurred shortly after the initiation of cardiopulmonary bypass. Successful repair was immediately confirmed with transesophageal ultrasonography. The animal was extubated shortly after returning to spontaneous ventilation but had to be reintubated 4 hr later due to tachypnea and decreased SpO2. Additional extubation attempts failed, necessitating continuous positive pressure ventilation, monitoring, and intensive care environment. Thoracic radiographs suggested adult respiratory distress syndrome. The animal required 14 days of intensive care before extubation of the trachea was successful. After 4 wk of isolation, the orangutan was successfully reintroduced to its family group.

The effects of physical form of feed, carbohydrate source, and inclusion of sodium bicarbonate on the diet selections of sheep.

We proposed an hypothesis that ruminants attempt to select a diet that promotes high levels of feed intake by maintaining optimal ruminal conditions. Three tests of the hypothesis considered whether the diet selection of sheep given either a choice of two high energy density (ED) feeds or a choice between a high and a low ED feed is affected by 1) sodium bicarbonate inclusion (NaHCO3; 1, 2, and 4% [wt/wt]) in the high [ED] feed); 2) dietary carbohydrate source (barley-based, B and sugar beet/ barley, S) of the high ED feed; or 3) physical form (alfalfa: pelleted, ALFP and long chop, ALFL) of the low ED feed. To conduct these, 42 lambs were used in seven 6 x 6 Latin squares, which were either foods ALFL and ALFP offered alone and paired with feed B or S and their NaHCO3 derivatives as a choice, or foods B and S offered alone and paired with their NaHCO3 derivatives as a choice. Each Latin square period lasted for 3 wk. For the choices between a NaHCO3-supplemented high ED feed and either a high or a low ED one, the inclusion of NaHCO3 increased feed intake. Its level of inclusion had a marked effect on the proportion of unsupplemented high ED feed selected (P < .05) but not on the proportion of low ED feed (alfalfa) selected. More alfalfa was selected when the high ED feed was based on barley (B) rather than sugar beet/barley (S) (P < .05). The physical form of the alfalfa affected diet selection because its selection was greater (P < .001) when ALFP (pelleted) was offered in the feed choice rather than ALFL (long-chop). The significant effects of NaHCO3 level, dietary carbohydrate, and physical form on the diet selection and feed intake of the sheep are consistent with the proposed experimental hypothesis.

Quantitative improvement in laryngoscopic view by optimal external laryngeal manipulation.

STUDY OBJECTIVE: To determine the improvement in laryngoscopic view obtained using both the Macintosh and Miller blades by applying optimal external laryngeal manipulation (OELM). DESIGN: Prospective, with each patient serving as his or her own control. SETTING: Inpatient operating rooms of a University Medical Center. PATIENTS: 181 informed and consenting adult nonpregnant patients requiring general anesthesia and tracheal intubation. The only exclusion criteria was the need to apply cricoid pressure to prevent aspiration of gastric contents. INTERVENTIONS: Anesthetized, paralyzed patients underwent laryngoscopy without external laryngeal manipulation and the laryngoscopic view was graded ("A") according to visualized structures [1.0-1.9 = all (1.0) or part of the vocal cords (90% = 1.1 and 10% = 1.9); 2 = just the arytenoids; 3 = just the epiglottis; 4 = just the soft palate]. The larynx was then quickly manipulated by the thumb and index and middle fingers of the laryngoscopist's right hand in both cephalad and posterior directions over the hyoid, thyroid, and cricoid cartilages until it was determined which vector and spot produced the optimal laryngoscopic view ("B"). MEASUREMENTS AND MAIN RESULTS: It was found that in every patient with a "A" greater than 1.0, OELM improved the view; i.e., "B" decreased relative to "A." For both the Macintosh blade patients and Miller blade patients with an "A" equal to 2, "B" decreased by one whole laryngoscopic grade in all patients. For both the Macintosh and Miller blade patients with an "A" equal to 3, "B" decreased by at least one whole laryngoscopic grade in all patients and by two laryngoscopic grades in most patients. No patient had an "A" equal to 4. The distribution of optimal-external-laryngeal-manipulation (OELM) spots for all patients was 1%, 40%, 48%, and 11% for the hyoid, high thyroid, low thyroid, and cricoid cartilages, respectively, and the distribution was not significantly different for either the Macintosh and Miller blade groups or for the "A" and "B" subgroups (i.e., "A" < 1.9, = 2 or = 3). CONCLUSIONS: We conclude that OELM can improve the laryngoscopic view by at least one whole grade, that the best way to determine OELM for an individual patient is on an empirical basis by manipulation of the larynx with the laryngoscopist's right hand, and that OELM should be an instinctive and reflex response to any "A" of 2, 3, or 4.

Diet selection in sheep: the role of the rumen environment in the selection of a diet from two feeds that differ in their energy density.

The effect of the energy density (ED) of feeds offered as a choice on the diet selection of sheep, and the relationship between the rumen environment and the diet selected from feeds of different ED were investigated in two experiments. In the first experiment two feeds, L and H, and their mixture M (3:1 w/w) were formulated. All feeds had similar calculated metabolizable protein:metabolizable energy (ME) ratios, but differed in ED (7.4, 8.1 and 10.1 MJ ME/kg fresh feed for L, M and H respectively). The feeds were offered ad lib. either singly or in paired choices (L/M, L/H and M/H; n6 per treatment) to growing sheep. Although the rate of live-weight (Lwt) gain on feed H was higher than on feeds L or M, and the daily rate of feed intake lower, the sheep on feed choices did not consume only feed H. Instead they selected a mixture of both feeds offered, such that the total amount of H consumed per kg fresh feed was similar on choices L/H and M/H. The rate of Lwt gain of sheep on choices L/H and M/H was not different from that achieved on feed H alone. In the second experiment the choice L/H was offered to fistulated sheep (10 months of age, mean Lwt 57.5 kg) in an 8 x 8 Latin square, with 7 d periods. Treatments were infusions into the rumen (total volume 1 litre) over 4 h on days 1-4 of each period of acid (HCl; Acid 1, 400; Acid 2, 300 and Acid 3, 200 mmol/l), alkali (NaOH; Alk 1, 316; Alk 2, 212 and Alk 3, 109 mmol/l) and control (NaCl; Con 1, 315 and Con 2, 209 mmol/l). Infusate osmolalities (mOs/kg) were 795 (Acid 1), 585 (Acid 2, Alk 1 and Con 1), 390 (Acid 3, Alk 2 and Con 2) and 200 (Alk 3). Infusion treatment significantly affected the diet selection of the sheep (P < 0.05) according to the osmolality of infusate, but not according to rumen pH. During infusions intake of feed H tended to decline with increasing treatment osmolality, whereas intake of L remained constant. The effects on diet selection and feed intake were of a short duration with no carry-over effects.(ABSTRACT TRUNCATED AT 400 WORDS)

The identification of polar organic compounds found in consumer products and their toxicological properties.

Exposure to volatile organic compounds (VOCs) in the indoor environment has received substantial research attention in the past several years, with the goal of better understanding the impact of such exposures on human health and well-being. Many VOCs can arise from consumer products used within the indoor environment. The VOCs emitted from five representative consumer products were collected onto Tenax-GC and subjected to thermal desorption and analysis by gas chromatography, in combination with low-resolution mass spectrometry (MS), high-resolution MS, and matrix-isolation Fourier transform infrared spectroscopy for structural characterization. An emphasis was placed on the polar organic compounds often used to provide fragrance in these products. The structures of a number of these compounds were confirmed, and an electronic literature search was carried out on them to determine any known toxic properties. The search revealed that many of the VOCs possess toxic properties when studied at acute, relatively high-level exposures. In addition, toxic effects were reported for a few of the chemicals, such as benzaldehyde, alpha-terpineol, benzyl acetate, and ethanol, at relatively low dose levels of 9-14 mg/kg. In general, the data were unclear as to the effect of chronic, low-level exposures. The widespread use of such chemicals suggests that the health effects of chronic exposures need to be determined. Validated analytical methods for the quantitative characterization of polar organic compounds at low concentrations will be required to make such work possible.

Evaluation of the Bullard laryngoscope using the new intubating stylet: comparison with conventional laryngoscopy.

The Bullard laryngoscope (BL) is a new device for managing the difficult airway. Previous publications on the BL are primarily descriptive, and fail to use internal controls (i.e., determine the best intubating mechanism) or external controls (i.e., compare the BL to a known standard such as conventional laryngoscopy). Therefore, we attempted to determine the best of four intubating mechanisms described for the BL (independently styletted endotracheal tube [ETT], the Bullard intubating forceps, an ETT with a directional tip or the new dedicated intubating stylet) and to determine whether time to successful intubation with the BL using the best intubating mechanism correlates with conventional grade of laryngoscopic view. The new intubating stylet provided the optimal intubating method; fewer attempts were required (1.1 vs 1.7, P = 0.005), and it took less time to successful tracheal intubation (39 +/- 34 s vs 83 +/- 74 s, P = 0.004) compared to the three other intubating mechanisms. Our results also suggest that the time to successful intubation with the BL using the intubating stylet was not affected by the conventional laryngoscopic grade; it was just as easy (and difficult) to intubate a conventional Grade I laryngoscopic view patient (full glottic view) as it was to intubate a conventional Grade III laryngoscopic view patient (visualization of just the epiglottis) with the BL. There were two failed intubations with the BL (3%) due to an inability to trap the epiglottis.(ABSTRACT TRUNCATED AT 250 WORDS)

An observational study of mothers with eating disorders and their infants.

Two groups of primiparous mothers and their infants were observed at home during play and at a mealtime when the infants were 12-24 months old. The index group consisted of mothers who had experienced an eating disorder during the postnatal year while the control group had been free from such psychopathology. The main findings were that, when compared to controls, the index mothers were more intrusive with their infants during both mealtimes and play; and that they expressed more negative emotion towards their infants during mealtimes but not during play. There were, however, no differences between the groups in their positive expressed emotion. The index infants' emotional tone was generally more negative and their mealtimes more conflictual compared to controls. Furthermore, the index infants tended to be lighter than controls and infant weight was found to be independently and inversely related to both the amount of conflict during mealtimes and the extent of the mother's concern about her own body shape.

A breath sampling device for measuring human exposure to volatile organic compounds in microgravity.

A compact device for the collection of alveolar air (breath) from humans aboard spacecraft was developed. The system uses silicone one-way valves that operate independent of gravity, and provide minimal backpressure. Small charcoal filters clean ambient air used for inhalation. The device provided good recoveries of organic compounds at the 20 ng/L level, with generally low carryover of these compounds to a blank sample following a sample at exposure to 100 ng/L. When water accumulated in the system, this carryover increased for highly water soluble compounds. The new device was used in parallel with a larger, previously developed alveolar air sampler that requires gravity for proper operation; comparable results were obtained with the two units. The device measures 47 x 34 x 11.4 cm and weighs approximately 3.2 kg. Sufficient space is available within the case to accommodate a number of sample collection options.

Elimination of volatile organic compounds in breath after exposure to occupational and environmental microenvironments.

Breath measurements offer the potential for a direct and noninvasive evaluation of human exposure to volatile organic compounds (VOCs) in the environments in which people live and work. This research study was conducted to further evaluate and develop the potential of this exposure assessment methodology. Several people were exposed to the atmosphere in six microenvironments for several hours. Air concentrations of VOCs were measured during these exposures and breath samples were collected and analyzed at multiple time points after the exposure to evaluate elimination kinetics for 21 VOCs. A new alveolar breath collection technique was applied. Elimination half-lives were estimated using a mono- and bi-exponential model. The alveolar breath collection and analysis methodology proved to be very useful for collecting many samples in short time intervals and this capability was very important for more accurately describing the initial phase of the decay curves. Breath decay curves were generated from samples collected over a four hour period after exposure for 21 of 24 target VOCs. A biexponential function generally provided a better fit for the decay data than did the monoexponential function, supporting a multi-compartment uptake and elimination model for the human body.

A canister-based method for collection and GC/MS analysis of volatile organic compounds in human breath.

A method previously used for collection and analysis of volatile organic compounds (VOCs) in human whole breath was modified to encompass compounds with higher vapor pressures. A VOC spirometer was designed for field studies of environmentally exposed populations with breath concentrations in the microgram/m3 (ppb) range. The VOC spirometer was configured for sample collection and GC/MS analysis of breath samples using stainless steel canisters. Recoveries of 17 analytes in synthetic breath through the spirometer at 4 and 21 degrees C were generally above 80% except for n-dodecane which demonstrated poor recoveries at the lower temperature. The maximum sample volume available for analysis during recovery studies with natural breath was 100 mL because of copious quantities of CO2 present. Decay curves showing the breath elimination of 1,1,1-trichloroethane and benzene from a man after exposure to consumer products demonstrates the utility of the method.

A device for sampling of human alveolar breath for the measurement of expired volatile organic compounds.

This report describes the development of a portable spirometer capable of collecting primarily alveolar breath into 1.8-L canisters for subsequent gas chromatographic/mass spectrometric (GC/MS) analysis. Based on CO2 measurements, greater than 97% of the breath collected is alveolar in origin. Sample collection takes place in approximately two minutes. Clean air for inhalation is provided by two organic vapor respirator cartridges. Studies of the breakthrough volume of test compounds at both the 5- and 50-micrograms/m3 levels indicate that each cartridge filter can be used to sample over 300 L of air and that this volume is not altered by intermittent use and storage of the filter for up to five days. In experiments designed to mimic human breathing, recoveries of test compounds through the device at the 5-mu/m3 level ranged from 87 to 112%. Essentially no volatile organic compound (VOC) memory (i.e., adsorption carryover by the device) was measured at the 50-micrograms/m3 level. The data suggest that the device can be used successfully for organic compounds with volatilities greater than that of p-dichlorobenzene.

Characterization of polyimide sorbents by using tracer pulse chromatography.

A modification of tracer pulse chromatography was used to rapidly evaluate four novel polyimide sorbents for use in air sampling. This technique utilized probe molecules with differenet functional groups to evaluate the surface retention characteristics when the sorbents were highly loaded by these chemicals and humidity. The evaluation of sorbents indicated the polymer subunits of each must have multiple sorption sites which is consistent with their chemical makeup. Some comparisons between the polyimides and Tenax-GC were made.

Neurosarcoidosis: evaluation using computed tomography and magnetic resonance imaging.

Two patients with unusual central nervous system sarcoid were investigated using computed tomography and magnetic resonance imaging, as well as other x-ray studies. A patient with intramedullary involvement of the spinal cord as well as nerve root involvement was examined. Follow-up examination after treatment with steroids showed a return to normal. The second patient had optic nerve involvement as well as two intracranial parenchymal lesions and granulomatous arachnoiditis. In this patient magnetic resonance imaging offered no advantages over computed tomography in the orbit but was significantly more accurate intracranially.