Harvest for Health, a Randomized Controlled Trial Testing a Home-Based, Vegetable Gardening Intervention Among Older Cancer Survivors Across Alabama: An Analysis of Accrual and Modifications Made in Intervention Delivery and Assessment During COVID-19

BACKGROUND

Accelerated functional decline is a concern among older cancer survivors that threatens independence and quality of life. Pilot studies suggest that vegetable gardening interventions ameliorate functional decline through improved diet and physical activity.

OBJECTIVE

The aim of this article was to describe the rationale, recruitment challenges, and enrollment for the Harvest for Health randomized controlled trial (RCT), which will test the impact of a home-based, vegetable gardening intervention on vegetable and fruit consumption, physical activity, and physical functioning among older cancer survivors. Modifications made to the intervention and assessments to assure safety and continuity of the RCT throughout the COVID-19 pandemic also are reported.

DESIGN

Harvest for Health is a 2-year, 2-arm, single-blinded, wait-list controlled RCT with cross-over.

PARTICIPANTS/SETTING

Medicare-eligible survivors of cancers with ≥60% 5-year survival were recruited across Alabama from October 1, 2016 to February 8, 2021.

INTERVENTION

Participants were randomly assigned to a wait-list control or a 1-year home-based gardening intervention and individually mentored by extension-certified master gardeners to cultivate spring, summer, and fall vegetable gardens.

MAIN OUTCOME MEASURES

Although the RCT's primary end point was a composite measure of vegetable and fruit consumption, physical activity, and physical functioning, this article focuses on recruitment and modifications made to the intervention and assessments during COVID-19.

STATISTICAL ANALYSES PERFORMED

χ2 and t tests (α < .05) were used to compare enrolled vs unenrolled populations.

RESULTS

Older cancer survivors (n = 9,708) were contacted via mail and telephone; 1,460 indicated interest (15% response rate), 473 were screened eligible and consented, and 381 completed baseline assessments and were randomized. Enrollees did not differ from nonrespondents/refusals by race and ethnicity, or rural-urban status, but comprised significantly higher numbers of comparatively younger survivors, those who were female, and survivors of breast cancer (P < .001). Although COVID-19 delayed trial completion, protocol modifications overcame this barrier and study completion is anticipated by June 2022.

CONCLUSIONS

This RCT will provide evidence on the effects of a mentored vegetable gardening program among older cancer survivors. If efficacious, Harvest for Health represents a novel, multifaceted approach to improve lifestyle behaviors and health outcomes among cancer survivors-one with capacity for sustainability and widespread dissemination.

Capturing High Resolution Plant Movement in the Field

Lodging of small grains due to environmental stresses results in yield loss, quality reduction, and difficulties with mechanical harvesting, which lead to economic consequences. New technological discoveries allow for faster and in situ measurements for determining the mechanics of loading stress and plant movement. The overall measurement of plant movement can be a very sophisticated method to mechanically test and predict the behavior of stems when exposed to wind. We investigated the inertial measurement of plants during different magnitude wind events. This type of analysis captures real time quantitative stem behavior during wind events. Using a 1.5 cm2 inertial measurement sensor attached to the upper panicle of a plant, we recorded the ranges and extremes of instantaneous linear acceleration and rotational velocity. When this technology was applied to historically known varieties of different lodging classification, the measurements were able to distinguish between cereal species and differences between movement of lodging susceptible and resistant plants without physical lodging. This type of technology could be used to improve field based lodging models and quantify movement resulting from micro changes in structural and composition of the stem, and to analyze plant movement in natural conditions with a resolution and specificity that has so far been prohibitively expensive and technologically challenging to achieve.

Image analysis and artificial intelligence in infectious disease diagnostics

BACKGROUND

Microbiologists are valued for their time-honed skills in image analysis, including identification of pathogens and inflammatory context in Gram stains, ova and parasite preparations, blood smears and histopathologic slides. They also must classify colony growth on a variety of agar plates for triage and assessment. Recent advances in image analysis, in particular application of artificial intelligence (AI), have the potential to automate these processes and support more timely and accurate diagnoses.

OBJECTIVES

To review current AI-based image analysis as applied to clinical microbiology; and to discuss future trends in the field.

SOURCES

Material sourced for this review included peer-reviewed literature annotated in the PubMed or Google Scholar databases and preprint articles from bioRxiv. Articles describing use of AI for analysis of images used in infectious disease diagnostics were reviewed.

CONTENT

We describe application of machine learning towards analysis of different types of microbiologic image data. Specifically, we outline progress in smear and plate interpretation as well as the potential for AI diagnostic applications in the clinical microbiology laboratory.

IMPLICATIONS

Combined with automation, we predict that AI algorithms will be used in the future to prescreen and preclassify image data, thereby increasing productivity and enabling more accurate diagnoses through collaboration between the AI and the microbiologist. Once developed, image-based AI analysis is inexpensive and amenable to local and remote diagnostic use.

A home-based mentored vegetable gardening intervention demonstrates feasibility and improvements in physical activity and performance among breast cancer survivors

BACKGROUND

The current study assessed the feasibility of a mentored home-based vegetable gardening intervention and examined changes in health-related outcomes among breast cancer survivors (BCS).

METHODS

BCS were randomized to either a year-long vegetable gardening intervention to begin immediately or a wait-list control. Master Gardeners mentored participants in planning, planting, and maintaining 3 seasonal gardens over the course of 1 year. Participant accrual, retention, and satisfaction rates of ≥80% served as feasibility (primary outcome) benchmarks. Secondary outcomes (ie, vegetable consumption, physical activity, performance and function, anthropometrics, biomarkers, and health-related quality of life) were collected at baseline and post-intervention (1-year follow-up) using subjective and objective measures.

RESULTS

The trial surpassed all feasibility benchmarks at 82% of targeted accrual, 95% retention, and 100% satisfaction (ie, experience ratings of "good to excellent" and willingness to "do it again"). Compared with the controls, intervention participants reported significantly greater improvements in moderate physical activity (+14 vs -17 minutes/week) and demonstrated improvements in the 2-Minute Step Test (+22 vs + 10 steps), and Arm Curl (+2.7 vs + 0.1 repetitions) (P values < .05). A trend toward improved vegetable consumption was observed (+0.9 vs + 0.2 servings/day; P = .06). Approximately 86% of participants were continuing to garden at the 2-year follow-up.

CONCLUSIONS

The results of the current study suggest that a mentored, home-based vegetable gardening intervention is feasible and offers an integrative and durable approach with which to improve health behaviors and outcomes among BCS. Harvest for Health led to the establishment of a group of trained Master Gardeners and gave rise to local and global community-based programs. Larger studies are needed to confirm the results presented herein and to define applicability across broader populations of survivors.

Assessing the Feasibility of a Mentored Home-Based Vegetable Gardening Intervention among Breast Cancer Survivors in the Deep South

To assess the feasibility of a mentored home-based vegetable gardening intervention among Breast Cancer Survivors (BCS) residing in the Birmingham, Alabama metropolitan area. Methods: Using a wait-list control design, BCS were randomized to either a year-long vegetable gardening intervention or a wait-list control. Intervention participants were provided with necessary supplies and paired with a Master Gardener from the Cooperative Extension. Master Gardeners mentored participants in planning, planting, and maintaining 3 seasonal gardens over 12 months, conducted monthly home-visits, and checked in bi-weekly via telephone or email. Feasibility assessment criteria consisted of participant accrual, retention, and satisfaction rates of ≥80%. Target participant accrual was 100. Participant satisfaction data were collected after study completion via structured telephone debriefing. Descriptive statistics were conducted using SPSS V24. Results: 82 BCS (Mage = 60 (39–84); Msurvivorship = 5 years (0.5–23); Mco-morbidities = 3.5 (0–12); ≥2 functional limitations = 86.6%; Caucasian = 73.2%; African-American = 26.8%) enrolled (82% accrual). Of these, four did not complete the study (2 refused to be wait-listed due to not wanting to wait to garden, 1 withdrew due to family obligations, and 1 was lost to follow-up), resulting in an retention rate of 95% over a 1-year period. All BCS who completed the intervention (n = 42) rated their Harvest for Health experience as “Good to Excellent”, reported that they would “do it again”, and planned to “continue to garden.” When asked to rate, on a scale of 1–10 (1 = not at all and 10 = very much), the influence of gardening on motivating behavior change, BCS reported that gardening motivated them to… “eat a healthier diet” (M = 8.38; SD = 2.07), “eat more vegetables” (M = 8.43; SD = 2.08), and “be more physically active” (M = 7.5; SD = 2.73). Conclusions: The vegetable gardening intervention proved to be feasible and provided new knowledge about the influence of gardening on motivating behavior change among BCS. Findings suggest that a mentored home-based vegetable gardening may offer an integrative approach to improve diet, vegetable consumption, and physical activity among BCS. Larger, future studies are warranted.

Pilot Randomized Controlled Trial of a Home Vegetable Gardening Intervention among Older Cancer Survivors Shows Feasibility, Satisfaction, and Promise in Improving Vegetable and Fruit Consumption, Reassurance of Worth, and the Trajectory of Central Adiposity

BACKGROUND

Holistic approaches are sought to improve lifestyle behaviors and health of cancer survivors long term.

OBJECTIVE

Our aim was to explore whether a home-based vegetable gardening intervention is feasible and whether it improves diet and other health-related outcomes among older cancer survivors.

DESIGN

We conducted a feasibility trial in which cancer survivors were randomized to receive a year-long gardening intervention immediately or to a wait-list control arm. Home visits at baseline and 1 year assessed physical performance, anthropometric indices, behavioral and psychosocial outcomes, and biomarkers.

PARTICIPANTS/SETTING

Participants included 46 older (aged 60+ years) survivors of locoregionally staged cancers across Alabama from 2014 to 2016. Forty-two completed 1-year follow-up.

INTERVENTION

Cooperative extension master gardeners delivered guidance to establish three seasonal vegetable gardens at survivors' homes. Plants, seeds, and gardening supplies were provided.

OUTCOMES

Primary outcomes were feasibility targets of 80% accrual and retention, and an absence of serious adverse events; other outcomes were secondary and explored potential benefits.

STATISTICAL ANALYSES

Baseline to follow-up changes were assessed within and between arms using paired t, McNemar's, and χ² tests.

RESULTS

This trial proved to be safe and demonstrated 91.3% retention; 70% of intervention participants rated their experience as "excellent," and 85% would "do it again." Data suggest significantly increased reassurance of worth (+0.49 vs -0.45) and attenuated increases in waist circumference (+2.30 cm vs +7.96 cm) in the gardening vs control arms (P=0.02). Vegetable and fruit consumption increased by approximately 1 serving/day within the gardening arm from baseline to follow-up (mean [standard error]=1.34 [1.2] to 2.25 [1.9] servings/day; P=0.02)] compared to controls (1.22 [1.1] to 1.12 [0.7]; P=0.77; between-arm P=0.06).

CONCLUSIONS

The home vegetable gardening intervention among older cancer survivors was feasible and suggested improvements in vegetable and fruit consumption and reassurance of worth; data also suggest attenuated increases in waist circumference. Continued study of vegetable gardening interventions is warranted to improve health, health behaviors, and well-being of older cancer survivors.

Genome-Wide Association Study of Spot Form of Net Blotch Resistance in the Upper Midwest Barley Breeding Programs

Pyrenophora teres f. maculata, the causal agent of spot form of net blotch (SFNB), is an emerging pathogen of barley in the United States and Australia. Compared with net form of net blotch (NFNB), less is known in the U.S. Upper Midwest barley breeding programs about host resistance and quantitative trait loci (QTL) associated with SFNB in breeding lines. The main objective of this study was to identify QTL associated with SFNB resistance in the Upper Midwest two-rowed and six-rowed barley breeding programs using a genome-wide association study approach. A total of 376 breeding lines of barley were evaluated for SFNB resistance at the seedling stage in the greenhouse in Fargo in 2009. The lines were genotyped with 3,072 single nucleotide polymorphism (SNP) markers. Phenotypic evaluation showed a wide range of variability among populations from the four breeding programs and the two barley-row types. The two-rowed barley lines were more susceptible to SFNB than the six-rowed lines. Continuous distributions of SFNB severity indicate the quantitative nature of SFNB resistance. The mixed linear model (MLM) analysis, which included both population structure and kinship matrices, was used to identify significant SNP-SFNB associations. Principal component analysis was used to control false marker-trait association. The linkage disequilibrium (LD) estimates varied among chromosomes (10 to 20 cM). The MLM analysis identified 10 potential QTL in barley: SFNB-2H-8-10, SFNB-2H-38.03, SFNB-3H-58.64, SFNB-3H-78.53, SFNB-3H-91.88, SFNB-3H-117.1, SFNB-5H-155.3, SFNB-6H-5.4, SFNB-6H-33.74, and SFNB-7H-34.82. Among them, four QTL (SFNB-2H-8-10, SFNB-2H-38.03 SFNB-3H-78.53, and SFNB-3H-117.1) have not previously been published. Identification of SFNB resistant lines and QTL associated with SFNB resistance in this study will be useful in the development of barley genotypes with better SFNB resistance.

Detailed methods of two home-based vegetable gardening intervention trials to improve diet, physical activity, and quality of life in two different populations of cancer survivors

BACKGROUND

Cancer survivors suffer from long-term adverse effects that reduce health-related quality of life (QOL) and physical functioning, creating an urgent need to develop effective, durable, and disseminable interventions. Harvest for Health, a home-based vegetable gardening intervention, holds promise for these domains.

METHODS

This report describes the methods and recruitment experiences from two randomized controlled feasibility trials that employ a waitlist-controlled design. Delivered in partnership with Cooperative Extension Master Gardeners, this intervention provides one-on-one mentorship of cancer survivors in planning and maintaining three seasonal vegetable gardens over 12months. The primary aim is to determine intervention feasibility and acceptability; secondary aims are to explore effects on objective and subjective measures of diet, physical activity and function, and QOL and examine participant factors associated with potential effects. One trial is conducted exclusively among 82 female breast cancer survivors residing in the Birmingham, AL metropolitan area (BBCS); another broadly throughout Alabama among 46 older cancer survivors aged >60 (ASCS).

RESULTS

Response rates were 32.6% (BBCS) and 52.3% (ASCS). Both trials exceeded 80% of their accrual target. Leading reasons for ineligibility were removal of >10 lymph nodes (lymphedema risk factor), lack of physician approval, and unwillingness to be randomized to the waitlist.

CONCLUSION

To date, recruitment and implementation of Harvest for Health appears feasible.

DISCUSSION

Although both studies encountered recruitment challenges, lessons learned can inform future larger-scale studies. Vegetable gardening interventions are of interest to cancer survivors and may provide opportunities to gain life skills leading to improvements in overall health and QOL.

The conserved carboxyl domain of MorC, an inner membrane protein of Aggregatibacter actinomycetemcomitans, is essential for membrane function

Morphogenesis protein C (MorC) of Aggregatibacter actinomycetemcomitans is important for maintaining the membrane morphology and integrity of the cell envelope of this oral pathogen. The MorC sequence and operon organization were found to be conserved in Gammaproteobacteria, based on a bioinformatic analysis of 435 sequences from representative organisms. Functional conservation of MorC was investigated using an A. actinomycetemcomitans morC mutant as a model system to express MorC homologs from four phylogenetically diverse representatives of the Gammaproteobacteria: Haemophilus influenzae, Escherichia coli, Pseudomonas aeruginosa, and Moraxella catarrhalis. The A. actinomycetemcomitans strains expressing the homologous proteins were assessed for sensitivity to bile salts, leukotoxin secretion, autoaggregation and membrane morphology. MorC from the most closely related organism (H. influenzae) was functionally identical to MorC from A. actinomycetemcomitans. However, the genes from more distantly related organisms restored some but not all A. actinomycetemcomitans mutant phenotypes. In addition, deletion mutagenesis indicated that the most conserved portion of the protein, the C-terminus DUF490 domain, was necessary to maintain the integrity of the membrane. Deletion of the last 10 amino acids of this domain of the A. actinomycetemcomitans MorC protein was sufficient to disrupt membrane stability and leukotoxin secretion. The data suggest that the MorC sequence is functionally conserved across Gammaproteobacteria and the C-terminus of the protein is essential for maintaining membrane physiology.

Assessing Genomic Selection Prediction Accuracy in a Dynamic Barley Breeding Population

Prediction accuracy of genomic selection (GS) has been previously evaluated through simulation and cross-validation; however, validation based on progeny performance in a plant breeding program has not been investigated thoroughly. We evaluated several prediction models in a dynamic barley breeding population comprised of 647 six-row lines using four traits differing in genetic architecture and 1536 single nucleotide polymorphism (SNP) markers. The breeding lines were divided into six sets designated as one parent set and five consecutive progeny sets comprised of representative samples of breeding lines over a 5-yr period. We used these data sets to investigate the effect of model and training population composition on prediction accuracy over time. We found little difference in prediction accuracy among the models confirming prior studies that found the simplest model, random regression best linear unbiased prediction (RR-BLUP), to be accurate across a range of situations. In general, we found that using the parent set was sufficient to predict progeny sets with little to no gain in accuracy from generating larger training populations by combining the parent set with subsequent progeny sets. The prediction accuracy ranged from 0.03 to 0.99 across the four traits and five progeny sets. We explored characteristics of the training and validation populations (marker allele frequency, population structure, and linkage disequilibrium, LD) as well as characteristics of the trait (genetic architecture and heritability, H² ). Fixation of markers associated with a trait over time was most clearly associated with reduced prediction accuracy for the mycotoxin trait DON. Higher trait H² in the training population and simpler trait architecture were associated with greater prediction accuracy.

The cell envelope proteome of Aggregatibacter actinomycetemcomitans

The cell envelope of gram-negative bacteria serves a critical role in maintenance of cellular homeostasis, resistance to external stress, and host-pathogen interactions. Envelope protein composition is influenced by the physiological and environmental demands placed on the bacterium. In this study, we report a comprehensive compilation of cell envelope proteins from the periodontal and systemic pathogen Aggregatibacter actinomycetemcomitans VT1169, an afimbriated serotype b strain. The urea-extracted membrane proteins were identified by mass spectrometry-based shotgun proteomics. The membrane proteome, isolated from actively growing bacteria under normal laboratory conditions, included 648 proteins representing 27% of the predicted open reading frames in the genome. Bioinformatic analyses were used to annotate and predict the cellular location and function of the proteins. Surface adhesins, porins, lipoproteins, numerous influx and efflux pumps, multiple sugar, amino acid and iron transporters, and components of the type I, II and V secretion systems were identified. Periplasmic space and cytoplasmic proteins with chaperone function were also identified. A total of 107 proteins with unknown function were associated with the cell envelope. Orthologs of a subset of these uncharacterized proteins are present in other bacterial genomes, whereas others are found exclusively in A. actinomycetemcomitans. This knowledge will contribute to elucidating the role of cell envelope proteins in bacterial growth and survival in the oral cavity.

Structural and functional characterization of a winter malting barley

The development of winter malting barley (Hordeum vulgare L.) varieties is emerging as a worldwide priority due to the numerous advantages of these varieties over spring types. However, the complexity of both malting quality and winter hardiness phenotypes makes simultaneous improvement a challenge. To obtain an understanding of the relationship between loci controlling winter hardiness and malt quality and to assess the potential for breeding winter malting barley varieties, we structurally and functionally characterized the six-row accession "88Ab536", a cold-tolerant line with superior malting quality characteristics that derives from the cross of NE76129/Morex//Morex. We used 4,596 SNPs to construct the haplotype structure of 88Ab536 on which malting quality and winter hardiness loci reported in the literature were aligned. The genomic regions determining malting quality and winter hardiness traits have been defined in this founder germplasm, which will assist breeders in targeting regions for marker-assisted selection. The Barley1 GeneChip array was used to functionally characterize 88Ab536 during malting. Its gene expression profile was similar to that of the archetypical malting variety Morex, which is consistent with their similar malting quality characteristics. The characterization of 88Ab536 has increased our understanding of the genetic relationships of malting quality and winter hardiness, and will provide a genetic foundation for further development of more cold-tolerant varieties that have malt quality characteristics that meet or exceed current benchmarks.

Mapping net form net blotch and septoria speckled leaf blotch resistance Loci in barley

Septoria speckled leaf blotch (SSLB), caused by Septoria passerinii Sacc., and net form net blotch (NB), caused by Pyrenophora teres f. teres Drechsler, are fungal diseases that decrease the yields of barley in the Upper Midwest. An effective way to manage these diseases is to plant resistant cultivars. To characterize the genetics of resistance to both pathogens, two advanced barley breeding lines, one resistant to NB (M120) and another resistant to SSLB (Sep2-72), were crossed, creating a population of 115 recombinant inbred lines. The two parents and the population were evaluated in three greenhouse seedling assays for each pathogen and for simple-sequence repeat and diversity arrays technology markers. Composite interval mapping revealed two major quantitative trait loci (QTL) associated with NB on chromosome 6H, located in bins 2 and 6. The QTL located in bin 6 explained 19 to 48% of the phenotypic variation and the QTL located in bin 2 explained 25 to 44% of the phenotypic variation. A new locus for resistance to SSLB, Rsp4, was identified on chromosome 6H, located in bins 3 to 4. Mapping these genes in elite breeding germplasm will accelerate the development and utilization of marker-assisted selection to enhance resistance to these diseases.

Genetic architecture of quantitative trait loci associated with morphological and agronomic trait differences in a wild by cultivated barley cross

Hordeum vulgare subsp. spontaneum is the progenitor of cultivated barley (Hordeum vulgare L.). Domestication combined with plant breeding has led to the morphological and agronomic characteristics of modern barley cultivars. The objective of this study was to map the genetic factors that morphologically and agronomically differentiate wild barley from modern barley cultivars. To address this objective, we identified quantitative trait loci (QTLs) associated with plant height, flag leaf width, spike length, spike width, glume length in relation to seed length, awn length, fragility of ear rachis, endosperm width and groove depth, heading date, flag leaf length, number of tillers per plant, and kernel color in a Harrington/OUH602 advanced backcross (BC2F8) population. This population was genotyped with 113 simple sequence repeat markers. Thirty QTLs were identified, of which 16 were newly identified in this study. One to 4 QTLs were identified for each of the traits except glume length, for which no QTL was detected. The portion of phenotypic variation accounted for by individual QTLs ranged from about 9% to 54%. For traits with more than one QTL, the phenotypic variation explained ranged from 25% to 71%. Taken together, our results reveal the genetic architecture of morphological and agronomic traits that differentiate wild from cultivated barley.

Analysis of the chromosome 2(2H) region of barley associated with the correlated traits Fusarium head blight resistance and heading date

Fusarium head blight (FHB) is a major disease of barley (Hordeum vulgare L.) that results in reduced grain yield and quality through the accumulation of the mycotoxin deoxynivalenol (DON). Coincident QTL for FHB severity, DON concentration, and heading date (HD) map to a region of chromosome 2(2H) designated Qrgz-2H-8. It is unclear whether disease resistance at this locus is due to a pleiotropic effect of late HD by delaying the host exposure to the pathogen or a tightly linked resistance gene. The objectives of this study were to develop a set of near isogenic lines (NILs) for the Qrgz-2H-8 region and to genetically dissect the QTL region containing the coincident traits. Two NIL populations were developed consisting of F(2)- and F(4)-derived recombinants from a cross between a BC(5) line carrying the donor parent (Chevron) alleles in the Qrgz-2H-8 region and the recurrent parent M69. Analysis of field and marker data from these NILs revealed that the Chevron alleles conditioning FHB resistance, late HD, and low DON concentration were successfully introgressed into the BC(5) parent line and were segregating among NILs. QTL analysis of the F(4)-derived population showed that the HD QTL is adjacent to the FHB QTL. Furthermore, a single NIL was identified that was similar to the resistant BC(5) parent for FHB severity and the early flowering parent M69 for HD. These results indicate that the relationship between FHB and HD at the Qrgz-2H-8 region is likely due to tight linkage rather than pleiotropy.

Exploiting selective genotyping to study genetic diversity of resistance to Fusarium head blight in barley

Numerous barley cultivars from around the world have been identified as potential sources of Fusarium head blight (FHB) resistance genes. All of these cultivars exhibit partial resistance, and several mapping studies have shown that resistance to FHB is controlled by multiple genes. Successful development of barley cultivars with high levels of FHB resistance will require combining genes from multiple sources. We characterized five potential new sources of FHB resistance ('AC Oxbow', 'Atahualpa', 'HOR211', 'PFC88209', and 'Zhedar#1') to determine if they contain new FHB resistance genes. Cluster analysis, using a set of 80 SSR markers distributed throughout the genome, showed that most of the new sources of resistance were not similar to three cultivars that have been used in previous FHB mapping studies ('Chevron', 'Frederickson', and 'Gobernadora'), with 'Atahualpa' and 'HOR211' being the most dissimilar. By selective genotyping, we determined whether markers linked to six known FHB resistance quantitative trait loci (QTLs), discovered in other genotypes, explained variation for resistance in advanced breeding populations created from the new sources of resistance. Markers linked to four of the six known QTLs were associated with FHB severity in at least one of the populations. However, none of the six QTL regions were associated with variation for FHB severity in populations derived from crosses that utilized sources of resistance HOR211 or PFC88209. Selective genotyping is an efficient method for breeders to utilize current QTL information about disease resistance to search for new resistance genes.

Host genetic effect on deoxynivalenol accumulation in fusarium head blight of barley

ABSTRACT One of the major concerns with Fusarium head blight (FHB) of barley is the potential health risks to livestock and humans through the accumulation of the mycotoxin deoxynivalenol (DON) in infected grain. To define the role of the host in DON accumulation during the early stages of disease development, we conducted a series of greenhouse experiments. We inoculated single spikelets of greenhouse-grown plants with Fusarium graminearum, moved the plants to a dew chamber, and harvested the inoculated spikelets after 72 h for DON analysis. We conducted a quantitative trait locus (QTL) analysis using a genetic mapping population, constructed with the parents Stander and Frederickson, that segregated for DON accumulation after single-spikelet inoculation in two experiments. A single QTL on chromosome 3 explained 18 and 35% of the phenotypic variation in the two experiments. To validate this QTL for DON accumulation, we used a DNA marker to select near-isogenic lines from a family from the mapping population that was segregating at this QTL. Disease symptom development was similar between the nearisogenic lines; however, the mean DON concentration of the lines homozygous for the allele from the high DON parent was 2.5-fold more than the lines homozygous for the alternate allele. A time course experiment showed that this effect on toxin accumulation was observed at 10 days post inoculation. The near-isogenic lines developed in this study should prove useful for further exploration of the role of DON in FHB.

Upper gastrointestinal hemorrhage and transcatheter embolotherapy: clinical and technical factors impacting success and survival

PURPOSE

To identify clinical and technical factors influencing the outcome of transcatheter embolotherapy for nonvariceal upper gastrointestinal (GI) hemorrhage and to quantify the impact of successful intervention on patient survival.

MATERIALS AND METHODS

A retrospective review was performed of all patients (n = 163) who underwent arterial embolization for acute upper GI hemorrhage at a university hospital over an 11.5-year period. Clinical success was defined as target area devascularization that resulted in the clinical cessation of bleeding and stabilization of hemoglobin level. The clinical condition of each patient at intervention was defined by history, laboratory examination, and two composite indicator variables. With use of logistic regression, the dependent variable, clinical success, was modeled on two categories of clinical and technical variables. A final model regressed patient survival on clinical success and other clinical variables.

RESULTS

None of the procedural variables analyzed had a significant influence on clinical success. Several clinical variables did impact clinical success, including multiorgan system failure (OR, 0.36; P =.030), coagulopathy (OR, 0.36; P =.026), and bleeding subsequent to trauma (OR, 7.1; P =.040) or invasive procedures (OR, 6.5; P =.009). Regardless of their clinical condition at intervention, patients who underwent clinically successful embolization were 13.3 times more likely to survive than those who had an unsuccessful procedure (CI, 4.54-39.2; P =.000). Nevertheless, patients with multiorgan system failure were 17.5 times more likely to die, independent of the outcome of the procedure (CI, 0.014-0.229; P =.000).

CONCLUSION

Arresting nonvariceal upper GI hemorrhage with transcatheter embolotherapy has a large positive effect on patient survival, independent of clinical condition or demonstrable extravasation at intervention. Aggressive treatment with transcatheter embolotherapy is advisable in patients with acute nonvariceal upper GI hemorrhage.

Influence of tomato genotype on growth of inoculated and indigenous bacteria in the spermosphere

We previously demonstrated a genetic basis in tomato for support of the growth of a biological control agent, Bacillus cereus UW85, in the spermosphere after seed inoculation (K. P. Smith, J. Handelsman, and R. M. Goodman, Proc. Natl. Acad. Sci. USA 96:4786-4790, 1999). Here we report results of studies examining the host effect on the support of growth of Bacillus and Pseudomonas strains, both inoculated on seeds and recruited from soil, using selected inbred tomato lines from the recombinant inbred line (RIL) population used in our previous study. Two tomato lines, one previously found to support high and the other low growth of B. cereus UW85 in the spermosphere, had similar effects on growth of each of a diverse, worldwide collection of 24 B. cereus strains that were inoculated on seeds and planted in sterilized vermiculite. In contrast, among RILs that differed for support of B. cereus UW85 growth in the spermosphere, we found no difference for support of growth of the biocontrol strains Pseudomonas fluorescens 2-79 or Pseudomonas aureofaciens AB254. Thus, while the host effect on growth extended to all strains of B. cereus examined, it was not exerted on other bacterial species tested. When seeds were inoculated with a marked mutant of B. cereus UW85 and planted in soil, RIL-dependent high and low support of bacterial growth was observed that was similar to results from experiments conducted in sterilized vermiculite. When uninoculated seeds from two of these RILs were planted in soil, changes in population levels of indigenous Bacillus and fluorescent Pseudomonas bacteria differed, as measured over time by culturing and direct microscopy, from growth patterns observed in the inoculation experiments. Neither RIL supported detectable levels of growth of indigenous Bacillus soil bacteria, while the line that supported growth of inoculated B. cereus UW85 supported higher growth of indigenous fluorescent pseudomonads and total bacteria. The vermiculite system used in these experiments was predictive for growth of B. cereus UW85 inoculated on seeds and grown in soil, but the patterns of growth of inoculated strains-both Bacillus and Pseudomonas spp.-did not reflect host genotype effects on indigenous microflora recruited from soil to the spermosphere.

Interactions of U2 gene loci and their nuclear transcripts with Cajal (coiled) bodies: evidence for PreU2 within Cajal bodies

The Cajal (coiled) body (CB) is a structure enriched in proteins involved in mRNA, rRNA, and snRNA metabolism. CBs have been shown to interact with specific histone and snRNA gene loci. To examine the potential role of CBs in U2 snRNA metabolism, we used a variety of genomic and oligonucleotide probes to visualize in situ newly synthesized U2 snRNA relative to U2 loci and CBs. Results demonstrate that long spacer sequences between U2 coding repeats are transcribed, supporting other recent evidence that U2 transcription proceeds past the 3' box. The presence of bright foci of this U2 locus RNA differed between alleles within the same nucleus; however, this did not correlate with the loci's association with a CB. Experiments with specific oligonucleotide probes revealed signal for preU2 RNA within CBs. PreU2 was also detected in the locus-associated RNA foci, whereas sequences 3' of preU2 were found only in these foci, not in CBs. This suggests that a longer primary transcript is processed before entry into CBs. Although this work shows that direct contact of a U2 locus with a CB is not simply correlated with RNA at that locus, it provides the first evidence of new preU2 transcripts within CBs. We also show that, in contrast to CBs, SMN gems do not associate with U2 gene loci and do not contain preU2. Because other evidence indicates that preU2 is processed in the cytoplasm before assembly into snRNPs, results point to an involvement of CBs in modification or transport of preU2 RNA.

Quantitative trait loci associated with resistance to Fusarium head blight and kernel discoloration in barley

Resistance to Fusarium head blight (FHB), deoxynivalenol (DON) accumulation, and kernel discoloration (KD) in barley are difficult traits to introgress into elite varieties because current screening methods are laborious and disease levels are strongly influenced by environment. To improve breeding strategies directed toward enhancing these traits, we identified genomic regions containing quantitative trait loci (QTLs) associated with resistance to FHB, DON accumulation, and KD in a breeding population of F(4:7) lines using restriction fragment length polymorphic (RFLP) markers. We evaluated 101 F(4:7) lines, derived from a cross between the cultivar Chevron and an elite breeding line, M69, for each of the traits in three or four environments. We used 94 previously mapped RFLP markers to create a linkage map. Using composite interval mapping, we identified 10, 11, and 4 QTLs associated with resistance to FHB, DON accumulation, and KD, respectively. Markers flanking these QTLs should be useful for introgressing resistance to FHB, DON accumulation, and KD into elite barley cultivars.

Genetic basis in plants for interactions with disease-suppressive bacteria

Plant health depends, in part, on associations with disease-suppressive microflora, but little is known about the role of plant genes in establishing such associations. Identifying such genes will contribute to understanding the basis for plant health in natural communities and to new strategies to reduce dependence on pesticides in agriculture. To assess the role of the plant host in disease suppression, we used a genetic mapping population of tomato to evaluate the efficacy of the biocontrol agent Bacillus cereus against the seed pathogen Pythium torulosum. We detected significant phenotypic variation among recombinant inbred lines that comprise the mapping population for resistance to P. torulosum, disease suppression by B. cereus, and growth of B. cereus on the seed. Genetic analysis revealed that three quantitative trait loci (QTL) associated with disease suppression by B. cereus explained 38% of the phenotypic variation among the recombinant inbred lines. In two cases, QTL for disease suppression by B. cereus map to the same locations as QTL for other traits, suggesting that the host effect on biocontrol is mediated by different mechanisms. The discovery of a genetic basis in the host for interactions with a biocontrol agent suggests new opportunities to exploit natural genetic variation in host species to enhance our understanding of beneficial plant-microbe interactions and develop ecologically sound strategies for disease control in agriculture.

Processing of endogenous pre-mRNAs in association with SC-35 domains is gene specific

Analysis of six endogenous pre-mRNAs demonstrates that localization at the periphery or within splicing factor-rich (SC-35) domains is not restricted to a few unusually abundant pre-mRNAs, but is apparently a more common paradigm of many protein-coding genes. Different genes are preferentially transcribed and their RNAs processed in different compartments relative to SC-35 domains. These differences do not simply correlate with the complexity, nuclear abundance, or position within overall nuclear space. The distribution of spliceosome assembly factor SC-35 did not simply mirror the distribution of individual pre-mRNAs, but rather suggested that individual domains contain both specific pre-mRNA(s) as well as excess splicing factors. This is consistent with a multifunctional compartment, to which some gene loci and their RNAs have access and others do not. Despite similar molar abundance in muscle fiber nuclei, nascent transcript "trees" of highly complex dystrophin RNA are cotranscriptionally spliced outside of SC-35 domains, whereas posttranscriptional "tracks" of more mature myosin heavy chain transcripts overlap domains. Further analyses supported that endogenous pre-mRNAs exhibit distinct structural organization that may reflect not only the expression and complexity of the gene, but also constraints of its chromosomal context and kinetics of its RNA metabolism.

Cloning, characterization, and chromosomal localization of human superillin (SVIL)

Supervillin is a 205-kDa F-actin binding protein originally isolated from bovine neutrophils. This protein is tightly associated with both actin filaments and plasma membranes, suggesting that it forms a high-affinity link between the actin cytoskeleton and the membrane. Human supervillin cDNAs cloned from normal human kidney and from the cervical carcinoma HeLa S3 predict a bipartite structure with three potential nuclear localization signals in the NH2-terminus and three potential actin-binding sequences in the COOH-terminus. In fact, throughout its length, the COOH-terminal half of supervillin is similar to segments 2-6 plus the COOH-terminal "headpiece" of villin, an actin-binding protein in intestinal microvilli. A comparison of the bovine and human sequences indicates that supervillin is highly conserved at the amino acid level, with 79.2% identity of the NH2-terminus and conservation of three of the four nuclear localization signals found in bovine supervillin. The COOH-terminus is even more conserved, with 95.1% amino acid identity overall and 100% conservation of the villin-like headpiece. Supervillin mRNAs are expressed in all human tissue tested, bu are most abundant in muscle, bone marrow, thyroid gland, and salivary gland; comparatively little message is found in brain. Human supervillin mRNA is approximately 7.5 kb; this message is especially abundant in HeLa S3 cervical carcinoma, SW480 adenocarcinoma, and A549 lung carcinoma cell lines. The human supervillin gene (SVIL) is localized to a single chromosomal locus at 10p11.2, a region that is deleted in some prostate tumors.

Effects of Soil Water Content and Soil Temperature on Efficacy of Metham-Sodium Against Verticillium dahliae

Soil column studies were conducted to investigate the influence of soil water content and temperature on the efficacy of metham-sodium and its degradation product methyl isothiocyanate against Verticillium dahliae. The viability of the microsclerotia (MS) of the fungus in the top 30 cm of fumigated and control columns was measured. Temperatures for studies were 2 or 22°C, and the soil water content, expressed as soil matric potential, varied from -23 (wet), -113 (moist), to -2485 J/kg (dry). There was a significant interaction of soil water content and temperature on the efficacy of metham-sodium against V. dahliae MS. For the low soil temperature (2°C) the fumigant was more effective against MS of the fungus in wet than in moist or dry soil Soil water content did not affect fungicidal activity of metham-sodium when the soil columns were maintained at 22°C. These results suggest that the fumigant has a greater efficacy against V. dahliae in wet/cold soil conditions compared to the other conditions tested. Consequently, it was recommended that metham-sodium be applied to fields by chemigation in late fall or early spring to obtain efficacious results.

Modeling dose-response relationships in biological control: partitioning host responses to the pathogen and biocontrol agent

ABSTRACT Breeding plants to improve the effectiveness of biocontrol agents is a promising approach to enhance disease suppression by microorganisms. Differences in biocontrol efficacy among cultivars suggest there is genetic variation for this trait within crop germplasm. The ability to quantify host differences in support of biological control is influenced by variation in host response to the pathogen and the dose of pathogen and biocontrol agent applied to the host. To assess the contribution of each of these factors to successful biocontrol interactions, we measured disease over a range of pathogen (Pythium) and biocontrol agent (Bacillus cereus UW85) inoculum doses. We fit dose-response models to these data and used model parameter estimates to quantify host differences in response to the pathogen and biocontrol agent. We first inoculated eight plant species separately with three species of Pythium and evaluated three dose-response models for their ability to describe the disease response to pathogen inoculum level. All three models fit well to at least some of the host-pathogen combinations; the hyperbolic saturation model provided the best overall fit. To quantify the host contribution to biological control, we next evaluated these models with data from a tomato assay, using six inbred tomato lines, P. torulosum, and UW85. The lowest dose of pathogen applied revealed the greatest differences in seedling mortality among the inbred lines, ranging from 40 to 80%. The negative exponential (NE) pathogen model gave the best fit to these pathogen data, and these differences corresponded to model parameter values, which quantify pathogen efficiency, of 0.023 and 0.091. At a high pathogen dose, we detected the greatest differences in biocontrol efficacy among the inbred lines, ranging from no effect to a 68% reduction in mortality. The NE pathogen model with a NE biocontrol component, the NE/NE biocontrol model, gave the best fit to these biocontrol data, and these reductions corresponded to model parameter values, which quantify biocontrol efficiency, of 0.00 and 0.038, respectively. There was no correlation between the host response to the pathogen and biocontrol agent for these inbred lines. This work demonstrates the utility of epidemiological modeling approaches for the study of biological control and lays the groundwork to employ manipulation of host genetics to improve biocontrol efficacy.

Detection and description of spatial patterns of bacterial brown spot of snap beans using cyclic samples

ABSTRACT Snap bean plants within seven-row segments that ranged from 65 to 147 m were sampled, using a cyclic sampling plan. In the cyclic sampling plan, only 6 of every 31 plants were sampled, but sampled plants were spaced such that pairs of plants that were 1, 2, 3, 4,..., 1,525 plants apart could be identified within each sample. Every leaflet on every sampled plant was assessed for bacterial brown spot, and the proportion of disease leaflets per plant was determined. Arcsine square-root-transformed disease incidence values were analyzed for spatial patterns by autocorrelation and spectral analyses. Disease patterns were detected at several different scales within a single snap bean row, at distances that ranged from 20 to 100 m. Approximately 23 to 53% of the disease variability in the samples could be described by sine and cosine curves, indicating a substantial component of regularity in the disease patterns. Possible origins for these regular patterns, including cultural practices and seed infestation, are discussed.

Isolation and characterization of the QM promoter

This report describes the isolation, sequencing and preliminary characterization of the first 1 kb of the 5'-regulatory region of the human QM gene. This region and the 5' -half of the transcribed region of the QM gene are enriched for C and G nucleotides with no bias against CpG dinucleotides--indicative of a CpG island. Several consensus GC boxes are present within the sequence. Most are clustered at the distal end, with one site present in the proximal 200 bp of the promoter. Electrophoretic mobility shift experiments and luciferase assays done in insect cells transfected with an Sp1 expression construct suggest that most of these sites can bind Sp1 or a closely related factor. In addition, the promoter is shown to be responsive to cAMP via a response element (CRE) in the proximal promoter. Studies with 5'-end and internal deletion mutants suggest that elements in the distal promoter exert their positive effect through interactions with a proximal element(s). Candidate proximal elements include the proximal GC box and a 43 bp region between a KpnI site (at -182) and a Smal site (at -139).

U2 and U1 snRNA gene loci associate with coiled bodies

The coiled bodies are nuclear structures rich in a variety of nuclear and nucleolar components including snRNAs. We have investigated the possibility that coiled bodies may associate with snRNA genes and report here that there is a high degree of association between U2 and U1 genes with a subset of coiled bodies. As investigated in human HeLa cells grown in monolayer culture, about 75% of nuclei had at least one U2 gene associated with a coiled body, and 45% had at least one U1 locus associated. In another suspension-grown HeLa cell strain, 92% of cells showed associated of one or more U2 genes with coiled bodies. In contrast to the U2 and U1 gene associations, a locus closely linked to the U2 gene cluster appeared associated with a coiled body only in 10% of cells. Associated snRNA gene signals were repeatedly positioned at the edge of the coiled body. Thus, this associated was highly nonrandom and spatially precise. Our analysis revealed a much higher frequency of association for closely spaced "doublet" U2 gene signals, with over 80% of paired signals associated as opposed to 35% for single U2 signals. This finding, coupled with the fact that not all genes were associated in all cells, suggested the possibility of a cell-cycle-dependent, possibly S-phase, association. However, an analysis of S- and non-S-phase cells using BrdU incorporation or cell synchronization did not indicate an increased level of association in S-phase. These and other results suggested that a substantial fraction of paired U2 signals represented association of U2 genes on homologous chromosomes rather than only replicated DNA. Furthermore, triple label analysis showed that in a significant fraction of cells U1 and U2 genes were both associated with the same coiled body. U1 and U2 genes were closely paired in approximately 20% of cells, over 60% of which were associated with a readily identifiable coiled body. This finding raises the possibility that multiple genes of a particular class may be in association with each coiled body. Thus, the coiled body may be a dynamic structure which transiently interacts with or is formed by one or more specific genetic loci, possibly carrying out some function related to their expression.

Compartmentalization of specific pre-mRNA metabolism: an emerging view

It is increasingly recognized that the mammalian interphase nucleus contains a number of non-membranous compartments in which macromolecules associated with different nuclear functions concentrate. This review focuses on the function of a major compartment consisting of domains highly enriched in pre-mRNA splicing components and poly (A) RNA, commonly identified by the splicing factor, SC-35. RNA synthesis, as judged interdomain space. However, uridine labels several types of nuclear RNA, only a fraction of which is pre-mRNA, and such studies cannot address the question of whether specific genes are transcribed in specific places. Similarly, interpretations of transcriptional inhibition studies are compromised by the global impact that inhibition has on nuclear structure and function, and by conflicting results. Localization of specific protein coding genes or RNAs circumvents these limitations. For several sequences studied thus far, a non-random relationship to SC-35 domains has been observed, with most, but not all, active genes encoding intron-containing pre-mRNAs showing a very high degree of association. In some cases this was directly demonstrated to be the site of transcription and processing. Consistent with earlier uridine incorporation studies, we have found that transcription occurs at the outer edge of the SC-35 domain, likely corresponding to the border of ultrastructures termed interchromatin granule clusters. These preliminary glimpses into gene localization strongly argue for a sequence-specific spatial association of some transcriptionally active genes with SC-35 domains, and suggest an integrated functional organization of the genome with these nuclear compartments enriched in splicing factors and poly (A) RNA.

Pit-1 exhibits a unique promoter spacing requirement for activation and synergism

The developmentally regulated Pit-1 transcription factor is involved in the activation of prolactin, growth hormone, and TSH beta expression. Using templates with spacing mutations to program an in vitro transcription system, the activity of a single Pit-1 proximal binding site within the rat prolactin promoter was shown to have a unique bimodal distance requirement. Transcription activity rapidly decreased with each 5-base pair (bp) addition to the spacing between the binding site and the TATA box. When positioned 20 bp upstream from its normal -36 position in the prolactin promoter, the activity of the Pit-1 binding site is reduced to basal levels. Placement of the site at a position 30 bp upstream resulted in a return of Pit-1-mediated activation. Using transient transfection assays in GH3 cells, the prime bimodal sites are also a requirement for optimum expression of chimeric prolactin-luciferase reporter constructs. Interestingly, optimal synergism of transcription in vivo by the prolactin distal enhancer, containing four Pit-1 binding sites and an estrogen-responsive element, is also sensitive to the placement of the proximal Pit-1 binding site. These data have important implications for Pit-1 activator function in pituitary cells and for general models of transcription synergism.

Characterization of cytokine-induced hyperalgesia

Agents which induce symptoms of illness, such as lipopolysaccharide (LPS), cause diverse effects including hyperalgesia. While previous studies have examined central pathways mediating LPS hyperalgesia, the initial steps in activating this system remain unknown. Since LPS induces the release of various cytokines and eicosinoids from immune cells, the present series of experiments examined the potential involvement of these substances in LPS hyperalgesia. This work demonstrates that: (a) Interleukin-1 beta (IL-1 beta) can produce hyperalgesia following either intraperitoneal or intracerebroventricular injection. In contrast, IL-1 beta delivered intrathecally did not affect pain responsivity. (b) Liver macrophages (Kupffer cells) appear to be critically involved, and relay signals to the brain via hepatic vagal afferents. (c) Both IL-1 beta and tumor necrosis factor appear to be critical mediators of LPS hyperalgesia. In contrast, prostaglandins do not appear to be involved. Taken together, these studies suggest that substances classically thought of as products of the immune system may dynamically enhance pain responsivity via actions either on the hepatic vagus or at central sites.

Neurocircuitry of illness-induced hyperalgesia

We have previously demonstrated that illness-inducing agents such as lithium chloride (LiCl) and the bacterial cell wall endotoxin lipopolysaccharide (LPS) produce hyperalgesia on diverse pain measures. The present series of studies attempted to identify the neurocircuitry mediating these effects. These studies have demonstrated that illness-inducing agents produce hyperalgesia by activating: (a) peripheral nerves rather than by generating a blood-borne mediator (Expt. 1); (b) vagal afferents, specifically afferents within the hepatic branch of the vagus (Expt. 2); (c) as yet unidentified brain site(s) rostral to the mid-mesencephalon (Expt. 6); (d) a centrifugal pathway that arises from the nucleus raphe magnus, and not from the adjacent nucleus reticularis paragigantocellularis pars alpha (Expts. 4 and 5); (e) a centrifugal pathway in the dorsolateral funiculus of the spinal cord (Expt. 3); and (f) the same centrifugal pathways for diverse illness inducing agents (Expts. 3, 7 and 8). These data call for the re-evaluation of a number of assumptions inherent in previous studies of hyperalgesia.

A Pit-1 binding site 3' to the transcription start site inhibits transcription elongation in vitro

The transcription factor Pit-1 can autoregulate its own expression by interacting with binding sites associated with the Pit-1 gene. One of these binding sites is located within the transcribed region of the gene and appears to be responsible for negatively regulating Pit-1 transcription. Using unique constructions in an in vitro transcription system, we show here that binding of Pit-1 to its recognition element can impede the progress of transcription elongation through the occupied site. We propose that this is a viable mechanism for Pit-1 autoregulation.

Cloning of the nucleic acid-binding domain of the rat HnRNP C-type protein

A cDNA encoding the nucleic acid-binding domain of the hnRNP C-type protein has been cloned by DNA-affinity screening of pituitary-derived expression libraries. An analysis revealed sequence identity with the human C-type cDNA and demonstrated the presence of a peptide sequence contained within the single-stranded DNA-binding protein, UP2, which was absent from the human cDNA. Structural analysis of the protein encoded by the rat cDNA demonstrated a net charge of +15 with 14.56% and 6.33% lysines and arginines, respectively, and an amino acid sequence that is consistent with an extensive helix-loop-helix-turn-helix structure.

Proteolytic enzymes in experimental spinal cord injury

Experimental spinal cord injury was produced in rats by dropping a 10 g weight from 30 cm upon dura-invested exposed spinal cord. Proteolytic activities at neutral (pH 7.6) and acid (pH 5.5 and 3.6) pH were determined in whole homogenate and the cytosolic fraction of the lesion (lumbar) and cervical control segments. The enzyme activity was monitored by SDS-PAGE analysis of the extent of substrate myelin basic protein (MBP) degradation. Activities (neutral and cathepsin B-like) in the sham-operated spinal cord were lower than those of cervical autologous control at 24 h after injury. The increase in neutral proteinase activity was progressive and greater in the lesion than the autologous control. A 61.5% +/- 3.5 loss of MBP was observed at 2 h following injury and increased at 24 h (78.2% +/- 3.4). The loss of MBP coincided with the appearance of several low molecular weight peptides. The cathepsin B-like and cathepsin D activities were also increased in the lesion but to a lesser extent than the neutral proteinase. The neutral proteinase and cathepsin B-like activity were inhibited by leupeptin and not by pepstatin while the converse obtained for cathepsin D activity. The release of neutral proteolytic activity which is nonlysosomal in origin suggests a novel hypothesis for the mechanism of traumatic axon-myelin injury.

Cortisone, vitamin A, and wound healing: the importance of measuring wound surface area

Traditional methods of measuring wound strength have often ignored one of the most important variables, i.e., wound surface area. Using a readily reproducible method of determining wound surface area, the effect of topical vitamin A on steroid-treated rats was studied. Findings revealed a significant (P less than 0.001) increase in wound strength with topical vitamin A application. No difference could be detected between steroid-treated and saline-treated rats when wound surface area was taken into account. Measurement of wound surface area is essential for meaningful results in wound healing studies.

Segmental bronchomalacia: successful surgical correction in an infant

Bronchomalacia is a rare cause of recurrent pneumonia, atelectasis, and in advanced cases, respiratory failure. It is generally treated symptomatically, but in end-stage cases with respiratory failure, bronchial resection can be performed with significant clinical benefit. This paper described the second reported case of successful bronchial resection for bronchomalacia.

Identification of enzymatic activities which process protein bound mono(ADP-ribose)

Enzymatic activities have been identified in extracts of cultured mouse cells which catalyze the removal of intact mono(ADP-ribosyl) residues linked to proteins at arginine. Activities that sequentially remove AMP and ribose 5-phosphate have also been identified. These results suggest that mono(ADP-ribosylation) of proteins is a reversible post translational modification.

Ca2+-accumulation in experimental spinal cord trauma

Quantitative measurements of the time course of calcium levels in experimental spinal cord trauma have been made. The injury was produced in rats by dropping a 10 g weight from 30 cm upon exposed dura-invested spinal cord. Lumbar sections of traumatized spinal cord and internal controls from remote cervical cord were excised and analyzed for calcium using atomic absorption spectroscopy. Total calcium levels in the lesioned cord were significantly elevated over control values within 45 min post-trauma (P less than 0.005), with maximal increase at 8 h. The increased levels of calcium in the lesion tissue confirm the previous morphologic finding of calcium deposits within axons in the lesion.

Effect of crude fat and crude protein on reproduction and weaning growth in four strains of inbred mice

Diets made from natural ingredients were fed to four inbred strains of mice (BALB/cAnN, C3H/HeN, C57BL/6N and DBA/2N) to study the effects of different concentrations of dietary crude protein, 18% and 24% with crude fat concentrations of 4%, 8%, and 12% on reproduction and weanling growth. The parameters measured included the number of litters and pups born, the number of litters and pups weaned, weanling mortality and weanling weight. Neither crude protein nor crude fat concentrations had significant effects on any of the reproductive parameters tested. However, a significant fat x protein interaction was observed for reproduction. These results indicate that the absolute concentrations of crude protein and crude fat in diets for inbred mouse production are not as important as the ratio of these two nutrients. There was also a differential response in reproduction among the strains due to the level of fat which indicates different dietary requirements for fat among these four inbred strains for maximum reproduction. In contrast to the results for reproduction, crude protein and crude fat independently had significant effects on weanling weight, but there was no effect due to the ratio of the nutrients. There was a significant increase in the weanling growth rate for all four strains as the dietary fat level increased, but a decrease in growth rate as the protein level increased. The reduced growth rate due to the increased protein was not of the same magnitude for all four strains which indicates specific protein requirements among the strains for weanling growth.

Skin exfoliation and purulent conjunctivitis in a new mutant-the exfoliative mouse

A spontaneous autosomal recessive mutation has been named the exfoliative mouse (genotype ex/ex). Exfoliative mice suffer a transient purulent conjunctivitis in their 3rd week and an exfoliative skin disease in their 4th week. Gram-negative bacilli are present in blood and cerebrospinal fluid during the conjunctivitis stage, and in skin during the exfoliative period. The mutant can be differentiated from the ichthyotic mouse mutant.