Plant–herbivore–carnivore Interactions in Cotton, <Emphasis Type="Italic">Gossypium hirsutum</Emphasis>: Linking Belowground and Aboveground

Most studies on plant–herbivore interactions focus on either root or shoot herbivory in isolation, but above- and belowground herbivores may interact on a shared host plant. Cotton (Gossypium spp.) produces gossypol and a variety of other gossypol-like terpenoids that exhibit toxicity to a wide range of herbivores and pathogens. Cotton plants also can emit herbivore-induced volatile compounds at the site of damage and systemically on all tissues above the site of damage. As these volatile compounds attract natural enemy species of the herbivore, they are thought to represent an indirect plant defense. Our study quantified gossypol and gossypol-like compounds in cotton plants with foliage feeding (Heliocoverpa zea), root feeding (Meloidogyne incognita), or their combination. Cotton plants with these treatments were studied also with respect to induced local and systemic volatile production and the attraction of the parasitic wasp Microplitis croceipes to those plants. We also evaluated whether foliage or root feeding affected foliar nitrogen levels in cotton. After 48 hr of leaf feeding and 5 wk of root feeding, local and systemic induction of volatiles (known to attract parasitoids such as M. croceipes) occurred with herbivore damage to leaves, and it increased in levels when root herbivory was added. Nevertheless, M. croceipes were equally attracted to plants with both leaf and root damage and leaf damage only. In contrast to previous studies in cotton, production of gossypol and gossypol-like compounds was not induced in leaf and root tissue following foliage or root herbivory, or their combination. We conclude that root feeding by M. incognita has little influence on direct and indirect defenses of Gossypium hirsutum against insect herbivory.     

Solitary intra-articular osteochondroma of the fingers in children

Injuries to the hepatic veins and retrohepatic vena cava have a high mortality due to uncontrolled hemorrhage. Successful repair may necessitate interruption of flow through the retrohepatic vena cava. Active bypass of the area is then needed to provide adequate venous return. Published methods for active bypass require cannulation of axillary and femoral veins in addition to clamping of the vena cava above and below the liver, often with limited exposure and significant risk. This report describes active bypass of the retrohepatic vena cava utilizing two right atrial cannulae. The simplicity of establishing the bypass together with the excellent exposure allowed repair of a bullet wound of the vena cava in one patient and the orderly performance of a left trisegmentectomy for a huge hepatic tumor in a second patient.     

Under the volcano: fire, ash and asthma?

AIMS: To investigate the prevalence of respiratory symptoms in known asthmatics, following exposure to airborne volcanic ash particles caused by the eruptions of Mount Ruapehu, New Zealand, commencing September 1995. METHOD: A one page postal questionnaire was sent to 1392 previously identified asthmatics 2 months after the first major eruption. RESULTS: Two hundred and thirty seven subjects had moved from the area, died or gone overseas since the original contact 4 years previously; therefore the target population was 1155 subjects of whom 361 lived in the exposed area and 794 in the nonexposed areas. The response rates were 246 (68.1%) in the exposed group and 477 (60.1%) in the nonexposed group making a total of 723 individuals. The prevalence of nocturnal shortness of breath in the last two months was 29.3% in the exposed group and 24.7% in the nonexposed (OR = 1.26, 95% CI; 0.83-1.78). Similarly 30.9% of the exposed group had an asthma attack in the last 2 months compared to 31.9% of the nonexposed group (OR = 0.96, 95% CI; 0.69-1.33). Finally, 48.4% of the exposed group used asthma medication in the 2 months following the eruption in comparison to 53% of the nonexposed group (OR = 0.83, 95%, CI; 0.61-1.12). CONCLUSIONS: The study showed no association between living in an area exposed to volcanic ash particles and either asthma symptoms or the use of asthma medication. There was a small but nonsignificant increase in nocturnal shortness of breath in the exposed group.     

Programmed changes of cell cycle regulators by serum deprivation regardless of skeletal myocyte differentiation

Permanent withdrawal of skeletal myoblasts from the cell cycle precedes differentiation. We examined the changes of protein levels of cell cycle regulators and the activities of CDKs in differentiating (by serum deprivation) or in differentiation-inhibited (by serum deprivation + TGF-beta1 treated) C2C12 skeletal myocytes. Regardless of differentiation, protein levels of most cyclins declined over time while this effect was delayed slightly by TGF-beta1 for cyclins D1 and F. Although the protein levels of CDKs gradually decreased over time, the activities of CDK2 and cdc2 decreased dramatically between 0 and 12 h after serum deprivation in both groups. Decreased CDK2 and cdc2 activities were temporally related to decreased DNA synthesis. While the p27KIP1 protein increased in both groups, the p21CIP1 protein increased only in differentiating cells. In vivo, protein expressions of cyclins, CDKs, and p21CIP1 were high in fetal, but almost undetectable in adult skeletal muscle. In contrast, the levels of p27KIP1 protein in skeletal muscle were high throughout development. Thus, changes of cell cycle regulators in differentiating C2C12 myocytes paralleled those during skeletal muscle development of mice. These results suggest that the rapid reduction of DNA synthesis and activities of CDKs slow reduction of protein levels of cyclins and CDKs, and that the increase of p27KIP1 are programmed mechanisms upon mitogen deprivation regardless of differentiation in skeletal myocytes.     

Proton MR spectroscopy after acute central nervous system injury: outcome prediction in neonates, infants, and children

PURPOSE: To evaluate the usefulness of proton magnetic resonance (MR) spectroscopy in predicting 6-12-month neurologic outcome in children after central nervous system injuries. MATERIALS AND METHODS: Localized single-voxel, 20-msec-echo-time MR spectra (including N-acetylaspartate [NAA], choline [Ch], creatine and phosphocreatine [Cr]) were obtained in the occipital gray matter in 82 patients and 24 control patients. Patient age groups were defined as neonates (< or = 1 month [n = 23]), infants (1-18 months [n = 31]), and children (> or = 18 months [n = 28]). Metabolite ratios and the presence of lactate were determined. Linear discriminant analysis-with admission clinical data, proton MR spectroscopy findings, and MR imaging score (three-point scale based on severity of structural neuroimaging changes)-was performed to help predict outcome in each patient. Findings were then compared with the actual 6-12-month outcome assigned by a pediatric neurologist. RESULTS: Outcome on the basis of proton MR spectroscopy findings combined with clinical data and MR imaging score was predicted correctly in 91% of neonates and in 100% of infants and children. Outcome on the basis of clinical data and MR imaging score alone was 83% in neonates, 84% in infants, and 93% in children. The presence of lactate was significantly higher in patients with poor outcome than in patients with good-moderate outcomes in all three age groups (neonates, 38% vs 5%; infants, 87% vs 5%; children, 64% vs 10% [chi 2 test, P < .02]). In children with poor outcomes, NAA/Cr ratios were significantly lower in infants (P = .006) and children (P < .001), and NAA/Ch ratios were significantly lower in infants (P = .001) and neonates (P = .05). CONCLUSION: Findings at proton MR spectroscopy helped predict long-term neurologic outcomes in children after central nervous system injury.     

One-stage versus two-stage Soave pull-through for Hirschsprung's disease in the first year of life

Several investigators have reported good results after a one-stage Soave procedure without a stoma for infants with Hirschsprung's disease. The authors reviewed their concurrent experience with the one- and two-stage approaches, comparing the two groups with respect to rate of complications and clinical outcome. Over a 3-year period, 36 infants with colonic Hirschsprung's disease presenting in the first year of life were treated with a Soave pull-through. Thirteen had a one-stage pull-through, and 23 had a two-stage procedure using an initial stoma. There was no difference with respect to median age at time of diagnosis, median follow-up period, length of aganglionosis, or male:female ratio between the groups. The incidences of major complications such as small bowel obstruction, segmental or acquired aganglionosis, anastomotic leak, and malabsorption were equal between the two groups. However, 13% of the two-stage patients required revision of the stoma. All major complications in the one-stage group were in those who weighed less than 4 kg at the time of surgery. Minor complications such as wound infection, perianal excoriation, and need for repeated dilatation were similar between the groups, but minor stoma-related complications (prolapse or retraction) occurred in 26% of the two-stage infants. When complications were stratified using a more sophisticated scale of severity, no significant difference was found between the groups. The overall complication rate was 1.5 events per patient in the one-stage group and 2.0 events per patient in the two-stage group. This small difference was related to the presence of a stoma in the two-stage group. Overall, 10 of 12 survivors in the one-stage group and 22 of 23 in the two-stage group were doing well, with normal bowel function noted on long-term follow-up (mean period, of 14 and 19 months, respectively). Both one- and two-stage approaches were associated with a significant complication rate, although long-term outcome was excellent in both groups. The higher complication rate in the two-stage group was attributable to the presence of a stoma. For small infants, it may be beneficial to delay the one-stage pull-through until weight exceeds 4 kg.     

Interactions of alpha-lactalbumins with lipid vesicles studied by tryptophan fluorescence

Complexes of alpha-lactalbumin (alpha-LA)1 with dimyristoylphosphatidylcholine (DMPC) or dipalmitoylphosphatidylcholine (DPPC) liposomes at pH 8 and at pH 2 have been obtained by means of gel filtration. Thermal denaturation of alpha-LA complexes of DMPC or DPPC at pH 8 was found to depend on the saturation of protein by metal cations. The intrinsic fluorescence of DMPC-alpha-LA and DPPC-alpha-LA was sensitive to two thermal transitions. The first transition corresponded to the Tc of the lipid vesicles, while the second transition arose from the denaturation of the protein. Fluorescence spectrum position suggested that at low temperature tryptophan accessibility increases upon protein-DMPC or protein-DPPC association. At temperatures above the protein transition (70 degrees C) tryptophan appears to interact significantly with the apolar phase of DMPC and DPPC, evidenced by spectral blue shifts. Whereas the free protein at pH 2 adopts the molten globule (MG) state and is characterized by the absence of a thermal transition, the rapidly-isolated DMPC-alpha-LA complex was characterized by the appearance of a distinct fluorescence thermal transition between 50 and 60 degrees C. This result is consistent with a model of a partially-inserted form of alpha-LA which may possess some degree of tertiary structure and therefore unfolds cooperatively.     

Warfarin and aspirin as thromboprophylaxis in atrial fibrillation

1. Anticoagulant therapy with warfarin is now established as effective thromboprophylaxis against stroke in atrial fibrillation, in high-risk persons. Aspirin is indicated in moderate-risk persons or if warfarin is contraindicated. 2. Risk stratification is suggested, using clinical factors supplemented by echocardiography, to aid choice of prophylaxis. 3. Further studies are required to establish how best to identify undiagnosed patients who have atrial fibrillation; to develop new therapeutic strategies; and to refine risk stratification to define which patients with atrial fibrillation are at the highest risk of stroke.