Nutritional interventions in adult fibrostenotic Crohn's disease: A systematic review

Background

Management of Crohn's disease (CD) using dietary interventions has become an area of increased research interest. There is a lack of specific research exploring if diet and nutrition interventions are beneficial in patients with strictures, as current dietary recommendations in fibrostenotic CD are often based on clinical judgment. The aim of this systematic review was to assess the impact of dietary interventions in fibrostenotic CD on medical and surgical outcomes.

Methods

A systematic search of MEDLINE (Ovid), EMBASE (Ovid), CINAHL (EBSCO), and Cochrane Central Register of Controlled Trials (Ovid) was conducted. Studies reporting dietary interventions or nutritional factors in fibrostenotic CD were included. Outcomes for studies assessing dietary interventions such as enteral nutrition were evaluated as changes in (1) CD symptoms (CD Activity Index), (2) stricture parameters on diagnostic imaging, and (3) rates of surgical or medical intervention following dietary interventions.

Results

Five studies were included in this review. Three studies assessed exclusive enteral nutrition (EEN), one evaluated total parenteral nutrition (TPN), and one studied a liquid diet. All included studies evaluated symptoms as an outcome, while diagnostic imaging parameters and surgical outcomes in the studies were either absent or too heterogeneous to appraise improvement post dietary intervention. Included EEN studies displayed similar efficacy, with approximately 60% of patients having symptom improvement. The included TPN study also reported 75% of patients with symptom improvement, while the liquid diet did not.

Conclusion

Exclusive enteral nutrition and total parental nutrition may provide benefit for use as a dietary intervention for fibrostenotic CD. There remains a need for high-quality controlled trials which utilize standardized definitions of strictures.

Disseminated intravascular coagulation from disseminated histoplasmosis in uncontrolled HIV - Case report

This case report describes an atypical presentation of a relatively common opportunistic infection, without documented exposure to areas known at the time to be endemic, resulting in catastrophic complications. The patient presented with a two month progressive history of vomiting, diarrhea, productive cough, and shortness of breath, on the background of poorly-controlled HIV. There was a low index of suspicion for infection with histoplasmosis, particularly given the large differential diagnosis and the lack of travel or endemic precedence. The case was complicated by the development of disseminated intravascular coagulation (DIC) prior to identification of the pathogen. Ultimately, the patient's goals of care transitioned to palliation, and treatments were discontinued. It is our hope that in the future, such outcomes might be prevented by considering disseminated histoplasmosis in systemically unwell patients with HIV, regardless of endemic exposure or specific presentation.

Understanding the role of community resilience in addressing the Ebola virus disease epidemic in Liberia: a qualitative study (community resilience in Liberia)

Background: There is an increasing recognition that community resilience plays a significant role in addressing health shocks like the Ebola virus disease (EVD) epidemic. However, the factors that constitute community resilience, and how these operate dynamically with other health system factors are less understood. Objective: This paper seeks to understand key factors that constitute community resilience and their role in responding to the EVD outbreak in Liberia. Methods: Key informant interviews were conducted between November 2017 and April 2018 with community representatives in Bomi, Margibi and Montserrado counties, and other national stakeholders involved in the EVD response in Liberia from 2014 to 2016. A national stakeholder meeting was conducted to verify and interpret information emerging from the interviews. Results: Factors that were critical for addressing the EVD epidemic in Liberia were identified as: strong leadership, tight bonds and sense of kinship at the community level; trusted communication channels; and trust among various health system stakeholders. These factors facilitated collective actions within communities and helped to direct response initiatives from other levels of the health system to the community. Foreign assistance was seen as crucial for recovery and revitalization of affected communities. However, such aid is often not targeted at addressing critical challenges in a sustainable way, especially when the assistance is highly restricted to specific activities, and those activities are determined without consultation with local actors and community groups. Conclusion: Efforts to systematically build responsible leadership and social capital at community level, including those that strengthen bonds in communities and trust across key actors in the health system, are needed to address health shocks like EVD outbreaks. Without building such capabilities in community resilience, it will be difficult to reap the expected gains from investments focusing on building physical capital and technical capabilities in health services and emergency preparedness.

Substrate-Borne Marking in the Parasitoid Wasp Urolepis rufipes (Hymenoptera: Pteromalidae)

Many animals use pheromone marking as a way to identify their territory or other resources. Among insects, substrate-borne marking is frequently reported for females, which in many species make marks containing oviposition-deterring pheromone, which other females avoid. However, there are fewer reports of substrate-borne marking for males. Here, marking in males of the parasitoid wasp Urolepis rufipes (Ashmead) is described. The conditions under which males mark and whether males and females respond to the males' marks were examined using behavioral observations. Males marked by dragging the tips of their abdomens across a substrate. They marked much more after mating and after consuming honey. They also marked more when with a female, irrespective of copulation, although not when with a male. Females spent more time on or near marked substrates, and males also responded to their own marks. Although males aggressively and successfully defended areas that they had marked against other males, males did not respond to another male's marks in the conspecific's absence. In contrast to males, females did not mark, either on the surface of hosts or on other surfaces, and males showed no detectable response to surfaces which females had recently occupied.

Developmental impact on trans-acting dosage effects in maize aneuploids

The reduction in vigor or viability caused by aneuploidy may be the result of trans-acting dosage effects that reduce gene expression. To investigate the molecular and developmental parameters of aneuploid syndromes, the expression of sucrose synthase1 (sus1) and shrunken1 (sh1) was studied in 2-week-old plants. Expression of sus1 and sh1 was first investigated in euploids, where it was found that both transcripts varied in a diurnal fashion. Chromosome arm number can be varied in a series from one to three doses in maize. In the 14 aneuploid dosage series examined, most caused changes in sus1 and sh1 RNA levels that were both gene and tissue specific. Results were compared to previous data from embryo and endosperm tissue. More dosage effects were detected and the magnitude of RNA level modulation was greater in 2-week-old plant tissue. These findings suggest that the molecular consequences of aneuploidy might become more severe as development progresses.

Specialty care for patients with epilepsy must become standard of care. Promotion of Specialty Care for Epilepsy Group

Epilepsy is a complex, common disorder with severe consequences for patients. The authors believe that a significant percentage of patients are receiving suboptimal care. The national standard of care needs to be upgraded to include the notion that patients with less than total seizure control or those suffering from any medication side-effects should be given the opportunity to receive specialty care by physicians with specific expertise in the field of epilepsy.

Stumbling corrective responses in healthy human subjects to rapid reversal of treadmill direction

The kinematics of stumbling and recovery induced by a rapidly reversing treadmill is described for eight healthy adults. Stability was achieved in approximately 400 ms following treadmill reversal (initiated at heel-strike) and the ensuing stumble. It appeared to be accomplished primarily by rapid flexion of the thigh and knee of the stance limb, which prevented damage to the knee joint and lowered the trunk, and by extension of the contralateral joints (swing limb), which contacted the ground presumably to deliver an impulsive thrust to counter the backward lean of the trunk. The movements of the ankle also contributed to the recovery from the stumble, but its movements were markedly more variable among the subjects than those of the thigh and knee. The observed kinematics to some extent resembled a crossed-extension reflex, which may have been triggered by muscle, joint, cutaneous or vestibular afferents. These data should provide a baseline by which to compare groups in which recovery from stumbling is known to be deficient (e.g., the elderly).

A surface measure for probabilistic structural computations

Computing three-dimensional structures from sparse experimental constraints requires method for combining heterogeneous sources of information, such as distances, angles, and measures of total volume, shape, and surface. For some types of information, such as distances between atoms, numerous methods are available for computing structures that satisfy the provided constraints. It is more difficult, however, to use information about the degree to which an atom is on the surface or buried as a useful constraint during structure computations. Surface measures have been used as accept/reject criteria for previously computed structures, but this is not an efficient strategy. In this paper, we investigate the efficacy of applying a surface measure in the computation of molecular structure, using a method of probabilistic least square computations which facilitates the introduction of multiple, noisy, heterogeneous data sources. For this purpose, we introduce a simple purely geometrical measure of surface proximity called maximal conic view (MCV). MCV is efficiently computable and differentiable, and is hence well suited to driving a structural optimization method based, in part, on surface data. As an initial validation, we show that MCV correlates well with known measures for total exposed surface area. We use this measure in our experiments to show that information about surface proximity (derived from theory or experiment, for example) can be added to a set of distance measurements to increase significantly the quality of the computed structure. In particular, when 30 to 50 percent of all possible short-range distances are provided, the addition of surface information improves the quality of the computed structure (as measured by RMS fit) by as much as 80 percent. Our results demonstrate that knowledge of which atoms are on the surface and which are buried can be used as a powerful constraint in estimating molecular structure.

Epidemiologic observations on infection with Rochalimaea species among cats living in Baltimore, Md

Cats from several sources in Baltimore, Md, were tested for seropositivity to Rochalimaea henselae and R quintana. Co-infection with Toxoplasma gondii or feline immunodeficiency virus was assessed as a risk factor for infection with Rochalimaea spp. Of 592 cats tested, 87 (14.7%) were seropositive for one or both Rochalimaea spp, although titers to R henselae were significantly higher than those to R quintana. Prevalence of seropositivity increased significantly with cat age and weight and was associated with seropositivity to T gondii but was not associated with gender. Prevalence of seropositivity was similar (12.5 to 14.4%) among groups of cats with some history of human contact but was higher among feral cats (44.4%). Whether cats are reservoirs or mechanical vectors of Rochalimaea spp that can cause diseases in people is still uncertain, but these findings indicated widespread infection of cats and suggested possible modes of transmission for Rochalimaea spp among cats.

Markers for pancreatic allograft rejection: comparison of serum anodal trypsinogen, serum amylase, serum creatinine and urinary amylase

Currently, the markers of acute rejection in pancreas allografts are not consistently reliable. The purpose of this study was to evaluate the ability of sAT to predict acute rejection as compared to serum creatinine (sCr), urinary amylase (uAmy) and serum amylase (sAmy). Eleven first-time acute rejection episodes in bladder-drained SPK recipients were studied. All rejection episodes were biopsy-proven (core kidney 9, fine needle kidney 2, fine needle pancreas 5). Sera obtained from days -7 to -1 (pre-treatment), day 0 (start of anti-rejection treatment), and +1 to +7 (post-treatment) periods were analyzed. Peak median sAT and sAmy levels occurred at day 0 compared to day 1 for sCr. uAmy trough levels occurred on days -4, -5 and +2. The difference between pre-treatment levels and those on day 0 were significant for sAT, sAmy and sCr but not for uAmy. Only in the case of sAT was the difference between day 0 levels and post-treatment levels significant. Both sAmy (0.87) and sCr (0.85) demonstrated positive correlation when compared to sAT whereas uAmy demonstrated a weak negative correlation (-0.24). This study confirms that sAT accurately predicts rejection after SPK transplantation.

Anterior cruciate ligament injuries in patients with open physes

From July 1988 to August 1989, six children with open physes and injuries to the anterior cruciate ligament were treated operatively. All injuries involved twisting episodes during sports activities. All six patients had meniscal abnormalities, and, additionally, one patient sustained a Grade III medical ligament tear and had a lateral patellar dislocation. Operative reconstruction used hamstring tendons and place a groove over the front of the tibia and a groove over the top of the femur without violation of the growth plates. The anterior cruciate ligament was primarily repaired (three patients) at the time of reconstruction, if possible. At 3 months, one patient underwent arthroscopic resection of adhesions for arthrofibrosis. There were no other complications. Five patients were evaluated with clinical examination, radiographs, magnetic resonance imaging, and functional testing at an average followup of 33.2 months (range, 25 to 38). Four of the five had returned to their preinjury level of sports participation. Manual maximum KT-1000 arthrometer side-to-side differences averaged 3.6 +/- 1.9 mm. The average Lysholm knee score was 95.2 +/- 2.5; the average Hospital for Special Surgery knee score was 96.6 +/- 2.3. There were no growth plate injuries. Despite the overall clinical stability, magnetic resonance image scans of the five patients consistently demonstrated areas of increased signal in the anterior cruciate ligament grafts.

Incidence, management and significance of surgical complications after pancreatic transplantation

Despite recent advances, pancreatic transplantation is still in evolution and is associated with considerable surgical morbidity. We reviewed the surgical complications of 127 consecutive whole pancreatic transplants performed at the University of Iowa between March 1984 and January 1992, to evaluate the impact of these complications on graft and patient outcome. Of these transplantations, 89 were simultaneous pancreatic and renal transplants, 32 pancreas after kidney and six pancreas alone. Of all complications requiring hospital admission, 29 percent were surgical in nature. Graft thrombosis (19 percent), deep wound infection (18 percent), duodenal leak (7 percent) and iliac artery disruption (3 percent) were all associated with significant graft (n = 28) and patient (n = 6) loss. In contrast, recurrent urinary tract infections (20 percent), recurrent pancreatitis (17 percent), superficial wound infections (13 percent) and recurrent hematuria (12 percent) did not affect patient or graft outcome. Surgical complications after technically successful transplants were associated with a 4.9 percent mortality rate and a 4.9 percent graft loss. The overall one year actuarial patient and pancreas graft survival rate was 86 and 75 percent, respectively. Despite ongoing refinements in surgical technique, pancreatic transplantation is still associated with considerable surgical morbidity. However, the outcome is favorable if these complications are managed aggressively.

Contralateral ovary in unilateral ovarian carcinoma: a search for preneoplastic lesions

Contralateral ovaries from patients with unilateral ovarian carcinoma were examined and compared to ovaries from age-matched control patients without ovarian carcinoma. The number of inclusion cysts were increased in ovaries from patients with ovarian carcinoma compared to the controls (p < 0.01). In addition, inclusions from cases with ovarian carcinoma showed serous differentiation more frequently than the controls (p < 0.01; odds ratio = 10.0; 95% confidence interval = 1.2-78.1). An age-related increase in the number of inclusion cysts was seen in the study group but not in the control group. These findings support a role of surface inclusion cysts in the genesis of ovarian carcinoma.

SV40 T antigen alone drives karyotype instability that precedes neoplastic transformation of human diploid fibroblasts

To define the role of SV40 large T antigen in the transformation and immortalization of human cells, we have constructed a plasmid lacking most of the unique coding sequences of small t antigen as well as the SV40 origin of replication. The promoter for T antigen, which lies within the origin of replication, was deleted and replaced by the Rous sarcoma virus promoter. This minimal construct was co-electroporated into normal human fibroblasts of neonatal origin along with a plasmid containing the neomycin resistance gene (neo). Three G418-resistant, T antigen-positive clones were expanded and compared to three T antigen-positive clones that received the pSV3neo plasmid (capable of expressing large and small T proteins and having two origins of replication). Autonomous replication of plasmid DNA was observed in all three clones that received pSV3neo but not in any of the three origin minus clones. Immediately after clonal expansion, several parameters of neoplastic transformation were assayed. Low percentages of cells in T antigen-positive populations were anchorage independent or capable of forming colonies in 1% fetal bovine serum. The T antigen-positive clones generally exhibited an extended lifespan in culture but rarely became immortalized. Large numbers of dead cells were continually generated in all T antigen-positive, pre-crisis populations. Ninety-nine percent of all T antigen-positive cells had numerical or structural chromosome aberrations. Control cells that received the neo gene did not have an extended life span, did not have noticeable numbers of dead cells, and did not exhibit karyotype instability. We suggest that the role of T antigen protein in the transformation process is to generate genetic hypervariability, leading to various consequences including neoplastic transformation and cell death.

Characterization of the rebinding of 125I-epidermal growth factor released from BALB/c-3T3 cells following accumulation in the presence of chloroquine

Lysosomotropic amines, such as chloroquine and methylamine, increase the intracellular accumulation of 125I-EGF by inhibiting lysosomal degradation. It has been shown previously that BALB/c-3T3 cells, prelabeled at 4 degrees C with 125I-EGF for 3 h and subsequently chased at 37 degrees C in the presence of chloroquine, internalized the surface bound 125I-EGF which was subsequently released into the extracellular medium in a high molecular weight form which co-migrated with native 125I-EGF. The secreted 125I-EGF rebound to the cells from which it was released more efficiently than does peptide in the extracellular media. We now show that when the BALB/c-3T3 cells were prelabeled at 37 degrees C for 2 h in the presence of chloroquine, the internalized 125I-EGF released into the medium was in a high molecular weight form which co-migrated with native 125I-EGF and did not rebind anymore efficiently than did peptide in the extracellular media. This lack of rebinding was not due to an alteration in the 125I-EGF molecule since it was still capable of rebinding to naive A431 cells, nor was it due to the exhaustion of EGF receptors on the BALB/c-3T3 cells. The inhibition of rebinding was observed only when the cells were treated with EGF in the presence of chloroquine, and was not due to a general down-regulation of membrane receptors. The differences between the rebinding of 125I-EGF at 4 degrees C and 37 degrees C suggest that EGF may be processed via different pathways in the cell.

Orbital histiocytic lymphoma arising from the ethmoid sinus

Histiocytic lymphoma has been reported previously as an orbital manifestation of systemic malignancy. We report herein a 49-year-old white male with orbital involvement from a sclerosing lesion in the ethmoid sinus that initially caused a biopsy-proven orbital inflammatory mass. This report of an orbito-sinus histiocytic lymphoma underscores the need to re-biopsy symptomatic orbital inflammatory lesions that continue to enlarge.

Interaction between monensin and lysosomotropic amines in the regulation of the processing of epidermal growth factor by BALB/c 3T3 cells

Monensin, like the lysosomotropic amines chloroquine and methylamine, caused a large accumulation of 125I-EGF in BALB/c-3T3 cells that was due to specific increases in the amount of intracellular intact hormone. However using a pulse-chase paradigm of 125I-EGF accumulation, marked differences were observed between monensin and the amines. When EGF was accumulated in the presence of monensin, there was a gradual loss of cell-bound radioactivity during a chase in the absence of the drug, and the labeled material recovered in the medium primarily consisted of degraded hormone. The continued presence of monensin in the chase medium substantively prevented the loss of cell bound material, and what little was recovered in the medium consisted of intact 125I-EGF. In contrast, when 125I-EGF was accumulated in the presence of methylamine, predominantly intact peptide was lost from the cells at a relatively high rate during the chase whether or not methylamine remained in the medium. When monensin was present in the chase medium following accumulation in the presence of either chloroquine or methylamine, the loss of intracellular 125I-EGF was essentially blocked.

Effects of phenothiazines on binding and processing of epidermal growth factor in 3T3 cells

Chlorpromazine (CPZ) or the functionally related N-(6-aminohexyl)-5-chloro-1-naphthalenesulfonamide caused a rapid decrease in binding of 125I-epidermal growth factor (EGF) that was due to a specific decrease in receptor affinity. The decrease in ligand binding was observed when cells were exposed to CPZ at either 4 degrees C or 37 degrees C but a rapid reversal of CPZs effects was observed only during a 37 degrees C incubation. In contrast to the decrease in 125I-EGF binding seen after short (30 min) accumulations at 37 degrees C, the presence of CPZ caused a large increase in the amount of cell-associated radioactivity after longer periods (over 1 h) of accumulation. Although the CPZ-induced effect was similar in extent to that observed after the addition of methylamine, the increased accumulation after CPZ was probably not due to a nonspecific ionic neutralization of the lysosomes. CPZ did not lower EGF binding in cultures chronically treated with a phorbol ester to reduce protein kinase C levels, although the CPZ-induced increases in accumulation were still observed in cells with reduced protein kinase C activity.

Chloroquine allows the secretion of internalized 125I-epidermal growth factor from fibroblasts

Incubation of cells with labelled hormone in the presence of the lysosomotropic agent chloroquine produces an enhanced intracellular accumulation of hormone and receptor. Using a pulse-chase paradigm in which cell surface receptors were labelled with 125I-EGF at 4 degrees C, it was found that when 100 microM chloroquine was present in the 37 degrees C chase medium intact hormone was accumulated in the medium. Without chloroquine, low molecular weight (mw) degradation products were found in the medium. The processes of receptor-mediated endocytosis and subcellular distribution of 125I-EGF-receptor complexes were unchanged by chloroquine. The source of the intact hormone accumulating in the medium was therefore an intracellular compartment(s). The 125I-EGF released from the cells could rebind to surface receptors and be re-internalized; rebinding was inhibited by unlabelled EGF or Concanavalin A in the incubation medium. The concentration of unlabelled EGF required to inhibit rebinding was more than three orders of magnitude greater than the amount of 125I-EGF whose rebinding was inhibited. Thus, the 125I-EGF released from intracellular sites was rebound preferentially over exogenous EGF. The possible pathways for secretion of intact 125I-EGF and mechanisms of its preferential rebinding are discussed.

Late G1 amino acid restriction point in human dermal fibroblasts

Human dermal fibroblasts arrested in G0 by maintenance in medium supplemented with 0.1% serum were not restimulated to divide when fresh medium containing 10% dialyzed serum but lacking group B amino acids (cystine, isoleucine, lysine, phenylalanine and tyrosine) was added. Unlike rodent cells, the addition of fresh serum-supplemented medium lacking only isoleucine did not cause a growth arrest. The amino acid sensitive growth arrest in human fibroblasts was dependent both on presynchronization in G0 as well as a prestarvation for amino acids prior to stimulation with high serum. When cells were restimulated in the absence of amino acids, they arrested predominantly in G1, although a small percentage of cells entered early S phase. When medium containing a complete complement of amino acids was then added, cells initiated DNA synthesis following a minimum lag of 2-3 hr. Growth arrested cells initiated DNA synthesis even when complete unsupplemented medium was added, although the addition of high concentrations of insulin or 10% serum increased the rate of entry.

Insulin-like growth factor II binding to cultured human chondrosarcoma cells

Cultured cells originally derived from a human chondrosarcoma (A1684) were used to investigate somatomedin binding in terms of kinetics and specificity. In this study, the rat somatomedin, multiplication-stimulation activity (MSA) was utilized. While the human chondrosarcoma cells did not exhibit a mitogenic response to MSA, the rate of transport of glucose and amino acids was significantly increased. In competitive binding experiments a specific insulin-insensitive MSA receptor was identified which showed half maximal displacement of tracer at a concentration of 250 ng/ml of MSA using whole cells. This receptor had an affinity constant of 4.8 X 10(7) M-1. Kinetic analysis of MSA binding to membrane preparations and to Triton X-100 solubilized membranes revealed an increase in the binding affinity to 1.28 X 10(8) M-1 and 2.8 X 10(8) M-1, respectively. Of particular significance is the observation that these cells have especially high levels of MSA receptors. Determination of binding capacity revealed that these cells contain approximately 1.9 X 10(6) MSA receptors per cell and therefore are an excellent model system for the characterization and purification of somatomedin receptors. Affinity labeling of the MSA receptor using the chemical crosslinking reagent, disuccinimidyl suberate, confirmed that this receptor was of the type II class of somatomedin receptors and exhibited a molecular weight of 218,000 under nonreducing conditions.

The effect of nitrogen fertilizer and irrigation frequency on a semi-dwarf wheat in south-east Australia. 1. Growth and yield

An experiment in south-eastern Australia in 1971 examined the semi-dwarf wheat WW15 when grown with two rates of nitrogen fertilizer (nil, 112 kg N ha-1) and under four irrigation regimes. The irrigation regimes comprised natural rainfall only (293 mm), and 2, 3 or 7 flood irrigations, scheduled according to cumulative pan evaporation. Nitrogen fertilizer had little effect, but grain yield increased from 4.3 t ha-1 with no irrigation to 8.1 t ha-1 with 7 irrigations. Each increase in irrigation frequency produced a significant (P < 0.01) increase in grain yield. A greater individual grain weight contributed most to the yield difference between nil and 2 irrigations. More spikes m-2 contributed most to the yield increase with higher irrigation frequencies. Irrigations also increased plant height, dry matter, leaf area and the proportion of fertile shoots.

The effect of nitrogen fertilizer and irrigation frequency on a semi-dwarf wheat in south-east Australia. 2. Water use

The semi-dwarf wheat WW15 was grown under four irrigation frequencies and two nitrogen rates in the Murrumbidgee Irrigation Area of south-eastern Australia. The irrigation treatments, which were scheduled using pan evaporation and rainfall, ranged from natural rainfall alone to seven flood irrigations. Water use was determined using the water balance equation, and measurements or irrigation water applied, rainfall, change in soil-stored moisture, and surface drainage. The water-use figures were high in comparison with values obtained overseas, ranging from 408 mm with no irrigation to 818 mm at the highest irrigation frequency. Despite the high water use, water-use efficiency was comparable with that for semi-dwarf wheat in other parts of the world, with a mean value of 10.4 kg grain ha-1 mm-1. Nitrogen fertilizer had little effect on plant growth and no effect on crop water use.

Growth and yield of a semi-dwarf and a standard height wheat cultivar in the Murrumbidgee Irrigation Area

A semi-dwarf cultivar (WW 15) and a standard height Australian wheat variety (Timgalen) were grown at two nitrogen levels and under three irrigation regimes in the Murrumbidgee Irrigation Area. Numerous plant measurements were taken to determine which attributes were associated with the superior yield of semi-dwarf wheat in this environment. WW 15 yielded 42% more grain than Timgalen and nitrogen fertilizer increased the yield of both varieties. The irrigation treatments did not affect yield because rainfall was above average. Total dry matter production and leaf area of WW 15 were similar to those of Timgalen, but WW 15 put a much greater proportion of its dry matter into grain. A greater number of grains per spike was the yield component responsible for the higher yield of WW 15. The increase in grain yield with the addition of nitrogen fertilizer was due to a general improvement in all aspects of crop vigour (e.g. tiller density, leaf area, total dry matter). There was no interaction between cultivars and nitrogen rates in their effect on grain yield.