CLM1 of Fusarium graminearum encodes a longiborneol synthase required for culmorin production.

Fusarium graminearum is a fungal pathogen of cereal crops (e.g., wheat, barley, maize) and produces a number of mycotoxins, including 15-acetyldeoxynivalenol, butenolide, zearalenone, and culmorin. To identify a biosynthetic gene for the culmorin pathway, an expressed-sequence-tag database was examined for terpene cyclase genes. A gene designated CLM1 was expressed under trichothecene-inducing conditions. Expression of CLM1 in yeast (Saccharomyces cerevisiae) resulted in the production of a sesquiterpene alcohol, longiborneol, which has the same ring structure as culmorin. Gene disruption and add-back experiments in F. graminearum showed that CLM1 was required for culmorin biosynthesis. CLM1 gene disruptants were able to convert exogenously added longiborneol to culmorin. Longiborneol accumulated transiently in culmorin-producing strains. The results indicate that CLM1 encodes a longiborneol synthase and is required for culmorin biosynthesis in F. graminearum.

Effect of light chain V region duplication on IgG oligomerization and in vivo efficacy.

A human immunoglobulin G1 (IgG1) antibody oligomer was isolated from a transfected myeloma cell line that produced a monoclonal antibody to group B streptococci. Compared to the IgG1 monomer, the oligomer was significantly more effective at protecting neonatal rats from infection in vivo. The oligomer was also shown to cross the placenta and to be stable in neonatal rats. Immunochemical analysis and complementary DNA sequencing showed that the transfected cell line produced two distinct kappa light chains: a normal light chain (Ln) with a molecular mass of 25 kilodaltons and a 37-kilodalton species (L37), the domain composition of which was variable-variable-constant (V-V-C). Cotransfection of vectors encoding the heavy chain and L37 resulted in production of oligomeric IgG.

Survival and growth of Salmonella Enteritidis PT 30 in almond orchard soils.

AIMS: To evaluate factors potentially contributing to the long-term persistence of Salmonella enterica serovar Enteritidis phage type (PT) 30 in an almond orchard. METHODS AND RESULTS: Surface and subsurface soil temperatures, and air temperatures in a radiation shelter, were recorded during a 12-month period, and were used to identify relevant storage temperatures (20 or 35 degrees C) for microcosms of two different soil types (clay and sandy loams) with moisture levels near saturation or near field capacity. Salmonella Enteritidis PT 30 was inoculated into the microcosms at 6 log CFU g(-1) dry weight. Between 14 and 180 days of incubation, counts of S. Enteritidis PT 30 decreased rapidly at 35 degrees C and were significantly different (P < 0.05) from counts at 20 degrees C, regardless of the soil type or moisture level. Salmonella was detected by enrichment of 10-g samples from all microcosms after 180 days of incubation at 20 degrees C, but from none of the microcosms held at 35 degrees C. To measure the potential for the growth of S. Enteritidis PT 30 in clay loam soil, an aqueous extract of almond hulls (containing 1.6% mono and disaccharides) or equivalent volume of water was added 7 days after inoculation. Significant (P < 0.05) growth of S. Enteritidis PT 30 was observed within 8 or 24 h of adding hull extract, but not water, to soil. CONCLUSIONS: Opportunities may exist for S. Enteritidis PT 30 to survive for an extended time in almond orchard soils and to grow in these soils where hull nutrients are released. SIGNIFICANCE AND IMPACT OF THE STUDY: Temperature has a significant impact on the long-term survival of S. Enteritidis PT 30 in soil, and nutrients leached from almond hulls may result in Salmonella growth. These factors should be considered in the design of Good Agricultural Practices for almonds.

Clinicopathologic features of lingual canine T-zone lymphoma.

Canine T-zone lymphoma (TZL) is a subtype of T-cell lymphoma characterized by unique histologic pattern and cytomorphology, immunophenotypic loss of CD45 expression, and an indolent clinical behaviour. Dogs with TZL typically present with 1 or more enlarged lymph nodes and/or lymphocytosis. We describe a novel extranodal presentation of TZL involving the tongue. Twelve dogs with tongue masses were diagnosed with lingual TZL based on a variable combination of immunophenotyping via flow cytometry, cytology, histopathology, immunohistochemistry and/or PCR for antigen receptor rearrangement (PARR) assay. Eleven dogs exhibited concurrent lymphocytosis and/or lymph node enlargement. Three cases were initially diagnosed as plasma cell tumours based on histology alone, thereby revealing a potential diagnostic challenge. Seven dogs achieved clinical remission and 4 achieved stable disease following variable treatment, consistent with the indolent nature of typical TZL involving the lymph nodes and peripheral blood. In 1 case the TZL resulted in progressive disease and failure to respond to treatment. In this case, the TZL exhibited histologic features of a higher grade neoplasm. This case series highlights a unique presentation of TZL and identifies a new differential diagnosis for lingual neoplasia. In this study, we characterize the clinical presentation, diagnostic features and patient outcomes of 12 dogs with lingual TZL.

Somatic excision of transposable element Tc1 from the Bristol genome of Caenorhabditis elegans.

We investigated the ability of the transposable element Tc1 to excise from the genome of the nematode Caenorhabditis elegans var. Bristol N2. Our results show that in the standard lab strain (Bristol), Tc1 excision occurred at a high frequency, comparable to that seen in the closely related Bergerac strain BO. We examined excision in the following way. We used a unique sequence flanking probe (pCeh29) to investigate the excision of Tc1s situated in the same location in both strains. Evidence of high-frequency excision from the genomes of both strains was observed. The Tc1s used in the first approach, although present in the same location in both genomes, were not known to be identical. Thus, a second approach was taken, which involved the genetic manipulation of a BO variant, Tc1(Hin). The ability of this BO Tc1(Hin) to excise was retained after its introduction into the N2 genome. Thus, we conclude that excision of Tc1 from the Bristol genome occurs at a high frequency and is comparable to that of Tc1 excision from the Bergerac genome. We showed that many Tc1 elements in N2 were apparently functionally intact and were capable of somatic excision. Even so, N2 Tc1s were prevented from exhibiting the high level of heritable transposition displayed by BO elements. We suggest that Bristol Tc1 elements have the ability to transpose but that transposition is heavily repressed in the gonadal tissue.

Multiple valve operation for advanced valvular heart disease: results and risk factors in 513 patients.

To assess the results and incremental risk factors affecting outcome after multiple-valve operation in the early blood cardioplegia era of cardiac surgery, follow-up data (mean +/- SD 3.1 +/- 2 years) were obtained on 97% of 513 patients (mean age +/- SD 58.8 +/- 10.5 years) who underwent a multiple-valve procedure between June 1976 and August 1985. Preoperatively 41% of patients were in New York Heart Association functional class III and 54% in class IV. Three groups accounted for 98.6% of the patients: 57.7% had an aortic and mitral valve procedure, 29% had a mitral and tricuspid valve procedure and 11.9% had a triple-valve procedure. The overall hospital mortality rate was 12.5% and overall 5-year survival rate was 67.1%. Hazard function analysis for all deaths revealed systolic pulmonary artery pressure (p less than 0.0001), age (p = 0.005), triple valve procedure (p less than 0.005), concomitant coronary bypass operation (p less than 0.005) and prior cardiac surgery (p less than 0.002) as the significant incremental risk factors predicting decreased survival in the early hazard phase; diabetes (p less than 0.005) predicted decreased survival in the late hazard phase. Postoperatively the condition of 80% of the patients improved to functional class I or II; only 0.6% remained in functional class IV. The 5-year rate of freedom from late combined valve-related morbidity was 81.7% and that of freedom from late combined valve-related morbidity and mortality was 71.7%. These results demonstrate excellent clinical improvement and late survival after multiple valve operation in patients with advanced valvular heart disease, justifying aggressive surgical therapy in these patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Crystallographic structure of an intact IgG1 monoclonal antibody.

The structure of an intact monoclonal antibody for phenobarbital, subclass IgG1, has been determined to 3.2 A resolution by X-ray crystallography. The molecule was visualized in a monoclinic unit cell having an entire immunoglobulin as the asymmetric unit. The two Fab segments, both with elbow angles of 155 degrees , were related by a rotation of 179.7 degrees plus a translation along the approximate dyad of 9 A. This is the first observation of such an Fab translation in a structurally defined antibody. The approximate 2-fold of the Fc was independent of that relating Fabs, making an angle of 107 degrees with the Fab dyad. The angle between long axes of the Fabs was 115 degrees, the most acute angle yet observed, yielding a distorted Y shaped molecule. This is in contrast to the distorted T shape of the only other intact IgG (2a) whose complete structure is known. Primary lattice interactions arise through formation of VH antiparallel beta ribbons whose strands are contributed by pseudo dyad related H2, and by L3 hypervariable loops from neighboring molecules. While one CH2 domain was mobile, Fabs and three domains of the Fc were well defined, as were hinge polypeptides connecting Fabs to the Fc, and the covalently attached oligosaccharides. Direct interactions are observed between hinge polypeptides, the glycosylated loop of one CH2 domain, and the oligosaccharide. Lattice interactions clearly influence, perhaps even determine the overall conformation of the antibody observed in this crystal. Comparison of this IgG1 with previously determined intact antibody structures extends the conformational range arising from segmental flexibility.

Genetic analysis of B-Peru, a regulatory gene in maize.

The B locus in maize is required for the accumulation of anthocyanin pigments. Numerous B alleles have been described: each determines a particular pattern of pigment synthesis with respect to the tissues that are pigmented and the time during development that pigment synthesis begins. We report here a genetic analysis of one B allele, B-Peru, which regulates synthesis of pigments in both kernel and plant tissues. We used stocks with active Mutator transposable elements to produce eight mutations in B-Peru. All eight alter pigment synthesis in all the kernel and plant tissues pigmented by B-Peru, suggesting that each mutation has disrupted a region of the gene required for expression in all tissues. Six of the mutations cause a colorless phenotype, while two cause a reduction in pigment in both kernel and plant tissues. Four of the mutations are unstable, and four are stable upon self-pollination. Multiple independent revertants were isolated from each unstable allele. DNA blot analysis demonstrated that all eight mutants are the result of insertions within an approximately 5-kb region that encodes the B-Peru transcript. One of the four unstable alleles contains a Mu element, Mu1.7. Two others contain insertions related to the Spm family of transposable elements. Thus, our Mutator stocks also contained active transposable elements from the unrelated Spm family. Our experiments suggest that the B-Peru allele is not complex, but contains a single coding region that regulates pigment synthesis in multiple tissues.

An international outbreak of salmonellosis associated with raw almonds contaminated with a rare phage type of Salmonella enteritidis.

During the winter of 2000 to 2001, an outbreak due to Salmonella Enteritidis (SE) phage type 30 (PT30), a rare strain, was detected in Canada. The ensuing investigation involved Canadian and American public health and food regulatory agencies and an academic research laboratory. Enhanced laboratory surveillance, including phage typing and pulsed-field gel electrophoresis, was used to identify cases. Case questionnaires were administered to collect information about food and environmental exposures. A case-control study with 16 matched case-control pairs was conducted to test the hypothesis of an association between raw whole almond consumption and infection. Almond samples were collected from case homes, retail outlets, and the implicated processor, and environmental samples were collected from processing equipment and associated farms for microbiological testing. One hundred sixty-eight laboratory-confirmed cases of SE PT30 infection (157 in Canada, 11 in the United States) were identified between October 2000 and July 2001. The case-control study identified raw whole almonds as the source of infection (odds ration, 21.1; 95% confidence interval, 3.6 to infinity). SE PT30 was detected in raw whole natural almonds collected from home, retail, distribution, and warehouse sources and from environmental swabs of processing equipment and associated farmers' orchards. The frequent and prolonged recovery of this specific organism from a large agricultural area was an unexpected finding and may indicate significant diffuse contamination on these farms. Identification of almonds as the source of a foodborne outbreak is a previously undocumented finding, leading to a North American recall of this product and a review of current industry practices.

Characterization of biosynthetic IgG oligomers resulting from light chain variable domain duplication.

We have characterized a human IgG1 monoclonal antibody composed of altered light chains. Each light chain consists of two identical variable domains and a kappa constant domain, in association with a normal gamma chain. This antibody assembled biosynthetically into a mixture of stable oligomers and monomers. Employing gel filtration, PAGE, and electron microscopy, we examined the antibody and the nature of the associations involved in oligomer formation. By engineering a protease factor Xa site between the duplicated light chain variable domains and examining the fragments produced following factor Xa cleavage, we demonstrated the association of the IgG monomers occurred through their duplicated VL domains. Electron microscopy showed the oligomeric antibody to be predominantly dimers and trimers in which the monomeric units were associated through the tips of the Fab portion of the antibody, presumably through the protruding N-terminal VL domains. Similar examination of monomers demonstrated several molecular forms, including individual molecules with self-crosslinked Fab arms and others displaying the open Y and T shapes typically observed for IgG antibodies. The monomers also displayed distally protruding domain-like structures. The oligomers produced by this cell line therefore occurred through the noncovalent interaction between the extra light chain variable domains.

Charge-coupled device imaging of rapid calcium transients in cultured arterial smooth muscle cells.

Transient changes in the concentration of intracellular free calcium are associated with the transduction of primary signals and the subsequent employment of Ca2+ as a second messenger in a multitude of cell types. These transients, typically monitored with the calcium-sensitive fluorescent dye Fura-2, are known to occur with a time course in the order of seconds. In order to accurately monitor such rapid changes in intracellular free calcium concentration in both single cells and simultaneously in several cells in a single field, we have developed a digital fluorescence imaging system based on a charge-coupled device (CCD) camera. We report here on the detailed kinetics of calcium increases in cultured arterial swine smooth muscle cells in response to the agonist ATP.

Lexicon size and its relation to foot preference in the African grey parrot (Psittacus erithacus).

To study footedness in parrots, an international survey of parrot owners was conducted. Responses were obtained from 524 individuals, including 70 owners of African Grey parrots (all animals > or = 10 months old). All respondents were given a 10-item questionnaire and a standard method for testing foot preference in their pets, and they were asked to count the number of separate words in their pets' lexicons of human speech sounds. Right-footed African Greys (N = 36) had significantly larger lexicons than left-footed African Greys (N = 34; P = 0.01). This difference could not be accounted for by group differences in training efforts or socialization/housing with conspecifics. A non-significant trend in the same direction was found in a comparison sample of Amazon parrots, although these genera are less adept than African Greys at learning human speech sounds. Other investigators have provided convincing evidence of lateralization, in the avian brain, for the analysis and memory of differing types of stimuli. In addition, there appears to be preferential left hypserstriatal activation for long-term memory consolidation. Our results suggest a relationship between lateral asymmetry for motor preference and asymmetric CNS mediation of a 'higher cognitive' function (i.e. the categorization and long-term mnestic processing of human speech sound.

Do left-handers die sooner than right-handers? Commentary on Coren and Halpern's (1991) "Left-handedness: a marker for decreased survival fitness".

Cross-sectional life span studies of handedness typically show decreasing percentages of left-handers in older age groups. In an article in Psychological Bulletin, S. Coren and D. F. Halpern (1991) argued that this age trend reflects the shorter life span of left-handers than right-handers. They presented 2 studies of their own providing what they regard to be direct evidence that left-handers, on average, die sooner than right-handers. They also proposed a variety of reasons for what they called left-handers' "decreased survival fitness." I discuss Coren and Halpern's reasons for rejecting a more conventional explanation of the life span data; the 2 studies that they offered in support of their argument; their analysis of other evidence they invoked to account for left-handers' putative decreased survival fitness; and, finally, new studies in which the longevity explanation was tested by more direct means than have been used thus far. I conclude that the case for the "decreased survival fitness" hypothesis cannot be sustained.

Role of amino acids and enhancement cardioplegia in routine myocardial protection. Experimental results.

The purpose of this study was to determine the effects of the addition of amino acids to blood cardioplegic solution and the value of terminal cardioplegia enhancement techniques in routine myocardial protection. Forty-five open-chest adult dogs were instrumented with sonomicrometry crystals to measure left ventricular long axis, midequatorial short axis, and wall thickness. The aorta was clamped for 120 minutes of cardiopulmonary bypass. Animals were randomly separated into four myocardial protection groups: (1) blood cardioplegic solution with amino acids and no terminal cardioplegia (n = 12); (2) blood cardioplegic solution with amino acids and warm amino acid terminal cardioplegia (n = 11); (3) blood cardioplegic solution with amino acids and cold amino acid terminal cardioplegia (n = 12); and (4) blood cardioplegic solution plus cold terminal cardioplegia (no amino acids, n = 10). Data for preload recruitable stroke work were obtained by inflow occlusion before bypass (baseline) and at 30 and 60 minutes after reperfusion and analyzed for changes in x-intercept and slope. A significant rightward shift in x-intercept did not occur in any group. When cardiac function was expressed as a percentage of baseline preload recruitable stroke work slope, improved functional recovery was seen at both 30 and 60 minutes in groups 2 (88.6% and 91.8%), 3 (85.8% and 86.9%), and 4 (88.6% and 92.6%) compared with group 1 (77.3% and 79.2%, p < 0.05). No significant difference was found in the degree of functional recovery among groups 2, 3, and 4. These results suggest that for myocardial protection of 2 hours in nonischemic hearts, a terminal dose of blood cardioplegic solution before unclamping is beneficial, but this positive effect is independent of amino acid supplementation and temperature.

Sternal wound infections and use of internal mammary artery grafts.

Previous studies have provided conflicting evidence as to whether an increased risk of mediastinitis is associated with use of the internal mammary artery as a coronary bypass graft. In this study the effects of internal mammary artery grafts on wound complications were analyzed in a prospective, nonrandomized fashion. At New York University Medical Center from January 1985 through May 1988, 2356 patients underwent isolated coronary revascularization. Among these patients 1394 received one or more internal mammary artery grafts (group I) and 962 had vein grafts only (group II). Group I had a mean age of 59.5 years versus 67.7 years in group II; diabetes was equally present in both groups (22.7% versus 24.7%). Operative mortality rate was 1.3% in group I and 5.6% in group II. Sternal infection was significantly more prevalent in group I (2.2%, 31/1394) than in group II (0.8%, 8/962). Multivariate analysis revealed that aortic crossclamp time, use of a single internal mammary artery graft, use of a double mammary graft, and diabetes were associated with increased risk of sternal infection. The use of bilateral internal mammary artery grafting doubled the odds ratio of the risk compared with use of a single mammary graft, and the combination of diabetes and double internal mammary artery grafts increased the odds ratio 13.9-fold. Patients with an internal mammary artery graft who had sternal infection had a longer period of hospitalization than patients without a mammary artery graft who had sternal infection. We conclude that the risk of sternal infection is increased by the use of an internal mammary artery graft, especially use of double mammary grafts in the presence of diabetes.

Neutrons confirmed in Nagasaki and at the Army Pulsed Radiation Facility: implications for Hiroshima.

Recent reports have clearly demonstrated that large discrepancies exist between neutron activation measured in Hiroshima and activation calculated using the current dosimetry system, DS86. The reports confirmed previous results for cobalt activation in Hiroshima that suggested problems, and this has spurred a joint U.S.-Japan effort to identify the source(s) of this discrepancy. Here, new results are presented that appear to eliminate both the measurements of neutron activation and the DS86 air-transport calculations as potential sources of the discrepancy in Hiroshima. Computer transport of DS86 fission neutrons through large distances of air was validated using concrete samples from Nagasaki and chloride detectors placed at selected distances from a bare uranium reactor. In both cases, accelerator mass spectrometry was used to measure thermal neutron activation via the reaction, 35Cl(n, gamma)36Cl (half-life, 301,000 years). Good agreement was observed between measurements of neutron activation and DS86 calculations for Nagasaki, as well as for the reactor experiment. Thus the large discrepancy observed in Hiroshima appears not to be due to uncertainties in air-transport calculations or in the activation measurements; rather, the discrepancy appears to be due to uncertainties associated with the Hiroshima bomb itself.

Multiple aneurysms of the coronary arteries in a patient with systemic aneurysmal disease.

A case of multiple coronary artery aneurysms in a patient with an abdominal aortic aneurysm and bilateral popliteal artery aneurysms is reported. As diagnosis and treatment of coronary artery disease become more aggressive, a higher incidence of detection of coronary artery aneurysms in conjunction with peripheral vascular lesions is likely. The role of coronary sinus cardioplegia in minimizing the risk of embolization from the coronary aneurysms during surgical repair is emphasized.

Effects of graded reductions in internal mammary artery bypass flow on left ventricular function.

This study investigated the controversial relationship between reduction in internal mammary artery (IMA) graft blood flow and left ventricular function in a canine model. Ten dogs underwent IMA grafting to the left anterior descending coronary artery. The left anterior descending coronary artery proximal to the IMA graft was intermittently occluded while IMA flow was mechanically controlled for 5-minute periods to produce four IMA flow groups representing 100%, 75%, 50%, and 25% of unoccluded IMA graft blood flow. As a control, the left ventricle was reperfused with native left anterior descending coronary artery flow between each IMA graft flow period to allow return to steady state. Sonomicrometry was used to obtain stroke work end-diastolic dimension relationship data for regional and global left ventricular function for each of the four flow groups. The global pressure recruitable work area relationship showed a significant rightward shift at 25% of unoccluded IMA flow, whereas the regional pressure recruitable work area relationship shifted at 50% of unoccluded IMA flow. Thus, regional myocardial function is more sensitive to reductions in IMA blood flow than is global left ventricular performance, and there is a significant IMA flow reserve for global left ventricular function.