Increased myoepithelial cells of bronchial submucosal glands in fatal asthma.

BACKGROUND: Fatal asthma is characterised by enlargement of bronchial mucous glands and tenacious plugs of mucus in the airway lumen. Myoepithelial cells, located within the mucous glands, contain contractile proteins which provide structural support to mucous cells and actively facilitate glandular secretion. OBJECTIVES: To determine if myoepithelial cells are increased in the bronchial submucosal glands of patients with fatal asthma. METHODS: Autopsied lungs from 12 patients with fatal asthma (FA), 12 patients with asthma dying of non-respiratory causes (NFA) and 12 non-asthma control cases (NAC) were obtained through the Prairie Provinces Asthma Study. Transverse sections of segmental bronchi from three lobes were stained for mucus and smooth muscle actin and the area fractions of mucous plugs, mucous glands and myoepithelial cells determined by point counting. The fine structure of the myoepithelial cells was examined by electron microscopy. RESULTS: FA was characterised by significant increases in mucous gland (p = 0.003), mucous plug (p = 0.004) and myoepithelial cell areas (p = 0.017) compared with NAC. When the ratio of myoepithelial cell area to total gland area was examined, there was a disproportionate and significant increase in FA compared with NAC (p = 0.014). Electron microscopy of FA cases revealed hypertrophy of the myoepithelial cells with increased intracellular myofilaments. The NFA group showed changes in these features that were intermediate between the FA and NAC groups but the differences were not significant. CONCLUSIONS: Bronchial mucous glands and mucous gland myoepithelial cell smooth muscle actin are increased in fatal asthma and may contribute to asphyxia due to mucous plugging.

Nocardia farcinica pericarditis after kidney transplantation despite prophylaxis.

A deceased-donor kidney transplant recipient developed purulent pericarditis caused by Nocardia despite trimethoprim-sulfamethoxazole (TMP-SMX) prophylaxis for Pneumocystis jirovecii. She was treated empirically with ceftriaxone and amikacin and subsequently underwent sternotomy with drainage of an intrapericardial abscess. Culture and susceptibility data demonstrated Nocardia farcinica, which was susceptible to SMX and amikacin, although resistant to ceftriaxone. Nocardia asteroides, the more common human pathogen, is generally susceptible to third-generation cephalosporins and TMP-SMX. N. farcinica is rare in the United States, more virulent and resistant than N. asteroides, and is more likely to cause disseminated disease. Successful therapy of disseminated Nocardia infections is dependent upon choice of appropriate empiric antibiotics in addition to surgical drainage of purulent fluid collections. TMP-SMX prophylaxis may not be sufficient to prevent infections due to Nocardia species in all immunosuppressed transplant recipients. Here, a rare complication of this unusual pathogen is discussed.

Molecular phylogenetic evidence for the evolution of specialization in anemonefishes.

Anemonefishes (genera: Amphiprion and Premnas; family Pomacentridae) are a group of 28 species of coral reef fishes that are found in obligate symbiosis with large tropical sea anemones. A phylogenetic hypothesis based on morphological analyses of this group suggests that the ancestral anemonefish was a generalist with similar morphology to other pomacentrids, and that it gave rise to other anemonefish species that were more specialized for living with particular species of host anemones. To test this hypothesis we constructed a molecular phylogeny for the anemonefishes by sequencing 1140 base pairs of the cytochrome b gene and 522 base pairs of the 16S rRNA gene for six species of anemonefishes (representatives of all subgenera and species complexes) and two other pomacentrid species. Three methods of phylogenetic analysis all strongly supported the conclusion that anemonefishes are a monophyletic group. The molecular phylogeny differs from the tree based on morphological data in that the two species of specialized anemonefishes (Premnas biaculeatus and Amphiprion ocellaris) were assigned to a basal position within the clade, and the extreme host generalist (Amphiprion clarkii) to a more derived position. Thus, the initial anemonefish ancestors were probably host specialists and subsequent speciation events led to a combination of generalist and specialist groups. Further phylogenetic studies of additional anemonefish species are required to substantiate this hypothesis.

Children's food intake following drinks sweetened with sucrose or aspartame: time course effects.

In two experiments, 2-5-year-old children's responsiveness to caloric density cues was examined. In a preloading protocol, consumption of fixed volumes of drinks (205 ml in Experiment 1; 150 ml in Experiment 2), sweetened with sucrose, aspartame, aspartame plus low glucose maltodextrin, or a water control, was followed by ad lib consumption from among a variety of foods. Caloric drinks had about 90 kcal in Experiment 1, 65 kcal in Experiment 2. The delay interval between the preload and the ad lib consumption was 0, 30 or 60 minutes. In Experiment 1, 24 4- and 5-year-old children participated in only one delay interval, while in Experiment 2, all 20 2- and 3-year-old children were seen in all conditions. Results revealed evidence of caloric compensation, but no evidence of preload x time delay interaction. In both experiments, aspartame also produced a significant suppression of intake relative to water, primarily due to the pattern at 30 min following the preload. Across conditions, the suppression following aspartame was usually significantly less than that produced by the caloric sweet drinks, providing evidence for postingestive effects. In Experiment 1, suppression of intake was related to the children's preferences for the foods, not to macronutrient content; consumption of nonpreferred foods was most suppressed. Consumption of sweetened drinks as long as 1 hour prior to eating suppressed food intake, and this common feeding practice may also reduce dietary variety.

Conditioned preferences: young children prefer flavors associated with high dietary fat.

In two experiments, 20 2-5-year-old children participated in a series of 8 conditioning trials to investigate whether they acquired conditioned preferences based on the fat content of a food. On different days, each child consumed fixed quantities of novelly flavored yogurts that were high or low in fat and energy density (220 or 110 kcal/serving). After conditioning, patterns of ad lib consumption data provided evidence of caloric compensation in response to the energy density differences in the preloads. Children consumed more following the low- than the high-fat preloads. Preference assessments, performed pre- and postconditioning, revealed conditioned flavor preferences based on fat content: children increased their preference for the high-density paired flavor, but no change in preference was noted for the low-density paired flavor. These data suggest that such conditioned flavor preferences based on energy density may be contributing to children's preferences for foods high in dietary fat.

Conditioned flavor preferences in young children.

In this experiment 11 children participated in a series of 8 pairs of conditioning trials in order to investigate the hypothesis that children could form conditioned flavor preferences based on caloric density. Unfamiliar drink flavors were used in these trials, and the drinks were either high in caloric density (155 kcal/150 ml) or low (less than 5 kcal/150 ml). Caloric density was altered by the addition of low glucose maltodextrin. Each child always had the same caloric density/flavor pairing throughout the conditioning trials. Each trial pair included one high and one low density preload, followed by ad lib consumption. These conditioning trials substituted for the children's regularly scheduled morning snack four days per week, one trial per day. Conditioning trials were given as a series of two-part snacks, consisting of fixed volumes of initially unfamiliar drinks, followed by the opportunity to eat a variety of foods ad lib. Two measures, obtained before and after conditioning, provided evidence for the formation of conditioned flavor preferences: 1) preference assessments, and 2) two-flavor choice tests. In addition, the ad lib consumption data indicated that the children were responsive to the caloric density manipulation, by consistently eating more following the low than the high density drink. The potential contribution of such acquired flavor preferences to the reduction of neophobia is discussed.

The postingestive consequences of fat condition preferences for flavors associated with high dietary fat.

To investigate whether children acquire conditioned preferences for flavors associated with high dietary fat content, 27 3- and 4-year-old children participated in a series of 12 conditioning or mere exposure sessions. Following an overnight fast, children who participated in conditioning trials consumed fixed quantities of a flavored yogurt drink that on half the days was high in fat and energy (954 kJ, 18 g fat/150 g serving) or contained no fat (277 kJ, 0 g fat/150 g serving). Children in the conditioning group consumed 150 g servings, children in the mere exposure group tasted 16 g or less of these same stimuli. Preferences were assessed before and after conditioning when the children were hungry and also postconditioning when the children were satiated. Results provided evidence for conditioned preferences based on the postingestive consequences of dietary fat. Children in the conditioning group learned to prefer the high-density paired flavor over the low-density paired flavor, and increased their preference for the high-density paired flavor from pre- to postconditioning. Children in the mere exposure group showed positive shifts in preference for both the fat-free and the high-fat paired flavors. In the conditioning group, preferences for the high-fat flavor was depressed by satiety, whereas the preference of the mere exposure group did not vary with hunger state. Conditioned flavor preferences, based on the postingestive consequences of fat intake, may contribute to children's preferences for foods high in dietary fat.

Focal myasthenia gravis in a dog.

A 10-month-old American cocker spaniel was evaluated for megaesophagus, aspiration pneumonia, but no appendicular muscle weakness. During hospitalization, weakness of the facial muscles developed, this resolved with anticholinesterase administration. Serum antibodies against acetylcholine receptors were documented, confirming the diagnosis of focal myasthenia gravis. Diagnosis, management, and medical treatment are discussed.

Conditioned meal initiation in young children.

In two experiments the conditioning of meal initiation was investigated. Preschool children ate snacks repeatedly in the presence of visual and auditory cues (CS+). On other days, other visual and auditory cues (CS-) were presented in the absence of food. In the second experiment, location also served as a CS. To test for conditioned meal initiation, children were first fed a snack to ensure that they were sated. Immediately following this, on different days, food was presented in the presence of the CS+ or the CS- cues. Data on latency to eating and total consumption revealed evidence for conditioning, at least for children who could correctly identify which cues had and had not been paired with the presentation of food.

Children's lunch intake: effects of midmorning snacks varying in energy density and fat content.

To determine the effects of preloads differing in energy density and fat content on subsequent lunch intake, 24 preschool children consumed 113 g ice-cream preloads as mid-morning snacks (containing 0, 12, or 18 g of fat, and 4 g of protein), followed nearly 2 h later by an ad libitum lunch consisting of a variety of foods. A fat-free baseline preload, consisting of dry cereal and apple juice, was also included. The baseline, fat-free, medium and high-fat preloads contained 334, 740, 953, and 1150 kJ per serving. All three ice-cream preloads produced significant but equivalent suppression of ad libitum lunch intake relative to baseline; lunch intake was not related to the fat content or energy density of the ice-cream preloads. Compensation at lunch was not macronutrient specific; children did not increase their fat intake at lunch following the fat-free preload. As energy and fat content of the preloads increased, children consumed significantly fewer foods at lunch, confirming previous findings. These changes in the variety of foods consumed were related to preference: regardless of preload, children continued to consume their preferred foods, while non-preferred foods tended to be eliminated following the higher energy preloads. Because compensation for energy was incomplete, energy intake of meals plus snacks increased with the energy content of the preload. Additional research is required to determine whether manipulating the fat and energy content of snacks produces similar effects when the unit of analysis is the child's total daily diet, rather than a single meal.

Treatment of intestinal parasites in Australian aboriginal children.

Five to nine-year-old Aboriginal children on Mitchell River Community maintained a satisfactory growth rate in the presence of multiple infections with intestinal parasites. Intensive treatment was successful in eliminating Giardia lamblia, Entamoeba histolytica, and Strongyloides stercoralis infections, but reinfection with G. lamblia was rapid. Treatment failed to produce any growth spurt in the group. This may have been due to the rapidity of reinfection, but raises the question of whether intestinal parasites contribute significantly to growth retardation or whether growth retarded children have an immune deficit rendering them more susceptible to parasitic infections.

An appliance based approach to the management of palatopharyngeal incompetency: a clinical pilot project.

The palatal lift appliance has been described in the dental literature for more than 30 years, yet its efficacy remains controversial in the management of palatopharyngeal incompetency during speech. A pilot project was undertaken to develop a clinical research protocol. In the pilot project, 32 patients had palatopharyngeal incompetency managed with a palatal lift appliance. The results of the treatment were that 21 of the 32 patients experienced reduction programs but, of these, seven still required surgery. Before firm conclusions on the use of the palatal lift appliance can be made, objective, measurable assessment of speech through well-designed clinical protocols is required.

What kind of exposure reduces children's food neophobia? Looking vs. tasting.

To determine the relative effectiveness of two different types of exposure on young children's preference for initially novel foods, 51 two- to five-year-old children received either "look" or "taste" exposures to seven novel fruits. Foods were exposed five, 10 or 15 times, and one food remained novel. Following the exposures, children made two judgments of each of the 21 pairs: one based on looking, the other on tasting the foods. Thurstone Case V scaling solutions were correlated with exposure frequency, and these were significant for the visual judgments of the looked at foods (r = 0.91), the visual judgments of the tasted (and looked at) foods (r = 0.97) and the taste judgments of the tasted foods (r = 0.94). The only non-significant relationship was for the taste judgments of the looked at (but never tasted) foods (r = 0.24). The results indicate that to obtain significant positive changes in preference, experience with the food must include experience in the modality that is relevant for the judgments. While visual experience produced enhanced visual preference judgments, visual experience was not sufficient to produce significantly enhanced taste preferences. This finding is consistent with a "learned safety" interpretation of the exposure effects noted in the taste judgments: experiences with novel tastes that are not followed by negative gastrointestinal consequences can produce enhanced taste preference.

Modulation of locomotor activity by multiple 5-HT and dopaminergic receptor subtypes in the neonatal mouse spinal cord.

Recently, it has been shown that bath-applied 5-HT can elicit fictive locomotion from perinatal mouse preparations. Since 5-HT acts on multiple receptor subtypes, the focus of this study was to examine which receptor families contribute to the genesis and modulation of locomotor activity. Blockade of 5-HT(2) (ketanserin or N-desmethylclozapine) or 5-HT(7) receptors (SB-269970) could reversibly block or modulate the locomotor-like pattern. A 5-HT(2) agonist (alpha-methyl-5-HT) was shown to be capable of activating the rhythm. Bath application of 5-HT(7) agonists (5-CT) generally led to a tonic increase in neurogram discharge, accompanied by bouts of rhythmic activity. Blockade of dopaminergic receptors (D(1) [R-(+)-SCH-23390 or LE 300]/D(2) [(+/-)-sulpiride or L-741,626] ) could reversibly disrupt the rhythm and most effectively did so when the D(1) and D(2) antagonists were added together. Conversely, 5-HT(2) and D(1)/D(2) agonists can interact to evoke locomotor activity. Overall, our data show that, in the neonatal mouse preparation, 5-HT evoked locomotion is partly dependent on activation of 5-HT(2), 5-HT(7), and dopaminergic receptor subtypes.

Life-style and organizational health insurance costs.

Most health professionals accept life-style as being causally related to morbidity and mortality, but many managers question this relationship, particularly in relation to corporate health care costs. This research compared responses from a lifestyle questionnaire (HealthScore), age, and organizational size, with Blue Cross/Blue Shield rates for eight work sites in Ohio. HealthScore was demonstrated to be the best predictor of health insurance rates. This relationship held for a secondary analysis involving Blue Shield rates adjusted for company size and coverage.