The Oomycete Microbe-Associated Molecular Pattern, Arachidonic Acid, and an Ascophyllum nodosum-Derived Plant Biostimulant Induce Defense Metabolome Remodeling in Tomato

Arachidonic acid (AA) is an oomycete-derived microbe-associated molecular pattern (MAMP) capable of eliciting robust defense responses and inducing resistance in plants. Similarly, Ascophylum nodosum extract (ANE) from the brown seaweed A. nodosum, a plant biostimulant that contains AA, can also prime plants for defense against pathogen challenges. A previous parallel study comparing the transcriptomes of AA- and ANE-root-treated tomatoes demonstrated significant overlap in transcriptional profiles, a shared induced resistance phenotype, and changes in the accumulation of various defense-related phytohormones. In this work, untargeted metabolomic analysis via liquid chromatography-mass spectrometry was conducted to investigate the local and systemic metabolome-wide remodeling events elicited by AA and ANE root treatment in tomatoes. Our study demonstrated AA and ANE's capacity to locally and systemically alter the metabolome of tomatoes with enrichment of chemical classes and accumulation of metabolites associated with defense-related secondary metabolism. AA- and ANE-root-treated plants showed enrichment of fatty acyl-glycosides and strong modulation of hydroxycinnamic acids and derivatives. Identification of specific metabolites whose accumulation was affected by AA and ANE treatment revealed shared metabolic changes related to ligno-suberin biosynthesis and the synthesis of phenolic compounds. This study highlights the extensive local and systemic metabolic changes in tomatoes induced by treatment with a fatty acid MAMP and a seaweed-derived plant biostimulant with implications for induced resistance and crop improvement.

Overlapping Local and Systemic Defense Induced by an Oomycete Fatty Acid MAMP and Brown Seaweed Extract in Tomato

Eicosapolyenoic fatty acids are integral components of oomycete pathogens that can act as microbe-associated molecular patterns to induce disease resistance in plants. Defense-inducing eicosapolyenoic fatty acids include arachidonic acid (AA) and eicosapentaenoic acid and are strong elicitors in solanaceous plants, with bioactivity in other plant families. Similarly, extracts of a brown seaweed, Ascophyllum nodosum, used in sustainable agriculture as a biostimulant of plant growth, may also induce disease resistance. A. nodosum, similar to other macroalgae, is rich in eicosapolyenoic fatty acids, which comprise as much as 25% of total fatty acid composition. We investigated the response of roots and leaves from AA or a commercial A. nodosum extract (ANE) on root-treated tomatoes via RNA sequencing, phytohormone profiling, and disease assays. AA and ANE significantly altered transcriptional profiles relative to control plants, inducing numerous defense-related genes with both substantial overlap and differences in gene expression patterns. Root treatment with AA and, to a lesser extent, ANE also altered both salicylic acid and jasmonic acid levels while inducing local and systemic resistance to oomycete and bacterial pathogen challenge. Thus, our study highlights overlap in both local and systemic defense induced by AA and ANE, with potential for inducing broad-spectrum resistance against pathogens. [Formula: see text] Copyright © 2023 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license.

Recent advances in health professional training on substance abuse disorders

The trainee health professional is influenced by many factors-personal and family experiences, the effectiveness of the teacher as role model, the attitudes in the institution in which training takes place and the cultural norms of society. Adverse experiences, if any, in these areas can negate the input from training programmes. This is particularly true for training in substance use disorders. In designing curricula in this field it is crucial to identify the core competencies expected at the end of training. 'Project Adept', a comprehensive compilation of curriculum materials, is based on such competencies. It emphasizes skills training and an adult learning mode of education. However, to achieve sustained curricular changes, development of a committed faculty is essential. Training must be complemented by systematic programmes of early diagnosis and treatment for substance use disorders in teaching hospitals. The need to train generalist physicians and to focus on early intervention have been endorsed by the recent Institute of Medicine report on the treatment of alcohol problems.

Trauma as an etiologic factor of primary bone lymphoma: a report of 4 cases

Primary bone lymphoma (PBL) is a rare entity. Nevertheless, very high long-term complete remission and survival rates following adriamycin-based chemotherapy alone or combined with involved-field radiation therapy have been reported. While the etiology is unknown, factors comprising local or general immunocompromised states have been suggested. Sporadic cases of local trauma followed by the emergence of primary bone lymphoma have been described. We describe 4 patients who developed primary bone lymphoma following direct trauma to a specific bone area. All 4 are alive with no evidence of disease after being treated with a combined chemo-radiotherapy regimen.

Urging college alcohol and drug policies that target adverse behavior, not use

Although "zero tolerance" policies are being enacted on campuses nationwide, these policies may not be the most effective means of creating safer and healthier environments for students. Many historical precedents illustrate the value of moderation over prohibition. College drug and alcohol policies should focus primarily on dysfunctional and disruptive student behaviors, not on student drug and alcohol use only.

Medical student attitudes toward drug addiction policy

This study explores the attitudes and perceptions of medical students concerning patients with addictions and policy issues related to drugs. Over 1,250 students from 15 medical schools responded to an anonymous survey concerning their experience and training regarding addictions, and their level of support or opposition for various drug policy approaches. Medical students expressed general support for treatment funding and related demand reduction strategies, but the strength of their support was influenced more by their political orientation than their perception of the effectiveness of the strategy. Students who identified themselves as liberals more strongly favored demand reduction and alternatives strategies such as needle exchange programs and drug courts. Conservatives more strongly favored supply reduction strategies including harsher sanctions for users. Need for additional training in medical school was indicated by the fact that 20% reported no training in addictions.

Changes in conceptions of learning for indigenous Australian university students

BACKGROUND

Conceptions of learning have been investigated for students in higher education in different countries. Some studies found that students' conceptions change and develop over time while others have found no changes. Investigating conceptions of learning for Australian Aboriginal and Torres Strait Islander university students is a relatively new area of research.

AIMS

This study set out to investigate conceptions of learning for Aboriginal and Torres Strait Islander university students during the first two years of their undergraduate degree courses in three Australian universities. Conceptions for each year were compared. Knowing more about learning as conceived by this cultural group may facilitate more productive higher educational experiences.

SAMPLE

The sample comprised 17 students studying various degrees; 11 were male and 6 were female. Ages ranged from 18 to 48 years; mean age was 26 years.

METHOD

This was a phenomenographic, longitudinal study. Individual semistructured interviews were conducted each year to ascertain students' conceptions of learning. Conceptions for second year were derived independently of those from first year. A comparative analysis then took place to determine any changes.

RESULTS

These students held conceptions of learning that were similar to those of other university students; however there were some intrinsic differences. On a group level, conceptions changed somewhat over the two years as did core conceptions reported by some individual students. Some students also exhibited a greater awareness of learning during their second year that resulted in three dimensions of changed awareness.

CONCLUSIONS

We believe the changed conceptions and awareness resulted from learning at university where there is some need to understand and explain phenomena in relation to theory. This brought about new understandings which allowed students to see their own learning in a relational sense.

Genetic polymorphism across regions of the three open reading frames of "Norwalk-like viruses"

Genomic characterization of Norwalk-like human caliciviruses (NLVs) originating from outbreaks and sporadic cases of acute gastroenteritis has revealed surprisingly high levels of diversity, even in the RNA polymerase gene, which is anticipated to be highly conserved. Since information on antigenic relationship is limited, due to the lack of a tissue culture system for these viruses, strains mostly are described on the basis of their genetic relatedness. However, the lack of uniformly applied criteria has led to a confusing array of strains with different groups employing different names for similar genetic lineages. Our goal was to conduct a structured analysis of genomic relationships among NLV strains in an attempt to provide an interim framework for genotyping. We assembled a panel of 31 potentially distinct genogroup I (GGI) and genogroup II (GGII) NLVs that reflected the diversity seen in strains detected by our laboratories and in published sequences. Phylogenetic analysis of sequences from regions of the open reading frames (ORF) 1, 2 and 3 was performed in order to investigate genomic relationships. The strains sequenced fell into seven phylogenetic groups in GGI and at least five phylogenetic groups in GGII, based on greater than 80% nucleotide identity in the region of ORF2 encoding the N-terminus of the capsid protein, and consistent clustering with high bootstrap values irrespective of the method used. Analysis of the ORF1 and ORF3 regions supported for most strains the clustering as established for those derived from ORF2. In the ORF1 region, used by most laboratories for diagnostic RT-PCR, clustering was consistent when a putative genotype border was set at 15% nucleotide mismatches for viruses in GGI and at 10% for viruses in GGII. Two strains grouped within different clusters based on ORF1 and ORF2 indicating that recombination may have occurred. We discuss the implications of these observations for the classification and typing of NLVs.

A health risk benchmark for the neurologic effects of styrene: comparison with NOAEL/LOAEL approach

Benchmark dose (BMD) analysis was used to estimate an inhalation benchmark concentration for styrene neurotoxicity. Quantal data on neuropsychologic test results from styrene-exposed workers [Mutti et al. (1984). American Journal of Industrial Medicine, 5, 275-286] were used to quantify neurotoxicity, defined as the percent of tested workers who responded abnormally to > or = 1, > or = 2, or > or = 3 out of a battery of eight tests. Exposure was based on previously published results on mean urinary mandelic- and phenylglyoxylic acid levels in the workers, converted to air styrene levels (15, 44, 74, or 115 ppm). Nonstyrene-exposed workers from the same region served as a control group. Maximum-likelihood estimates (MLEs) and BMDs at 5 and 10% response levels of the exposed population were obtained from log-normal analysis of the quantal data. The highest MLE was 9 ppm (BMD = 4 ppm) styrene and represents abnormal responses to > or = 3 tests by 10% of the exposed population. The most health-protective MLE was 2 ppm styrene (BMD = 0.3 ppm) and represents abnormal responses to > or = 1 test by 5% of the exposed population. A no observed adverse effect level/lowest observed adverse effect level (NOAEL/LOAEL) analysis of the same quantal data showed workers in all styrene exposure groups responded abnormally to > or = 1, > or = 2, or > or = 3 tests, compared to controls, and the LOAEL was 15 ppm. A comparison of the BMD and NOAEL/LOAEL analyses suggests that at air styrene levels below the LOAEL, a segment of the worker population may be adversely affected. The benchmark approach will be useful for styrene noncancer risk assessment purposes by providing a more accurate estimate of potential risk that should, in turn, help to reduce the uncertainty that is a common problem in setting exposure levels.

Plasma pharmacokinetics of warfarin enantiomers in cats

The purpose of this study was to determine the dispositions of S-warfarin and R-warfarin in normal cats following intravenous and oral administrations of racemic warfarin. Citrated blood samples were collected from 10 cats prior to and at times 5, 15, and 30 min, 1, 2, 3, 4, 5, 6, 12, 24, 36, 48, 72, 96, and 120 h following a single intravenous bolus of 0.5 mg/kg of racemic warfarin. After a 21-day washout period, samples were then similarly collected in three groups of four cats for 120 h following oral administration of 0.1, 0.25, and 0.5 mg/kg racemic warfarin. S-warfarin and R-warfarin were detected using a high-performance liquid chromatography assay validated for cat plasma. Drug concentration-time curves were subjected to non-compartmental analysis. Median pharmacokinetic parameters associated with the intravenous administration of 0.5 mg/kg racemic warfarin were as follows: t1/2 (S:28.2, R:18.3 h), area under the plasma concentration-time curve (AUC; S:33.0, R:24.6 h*microg/mL), area under the moment curve (AUMC; S:1889, R:527.8 h*h*microg/mL), and mean residence time (MRT; S:38.7, R:20.9 h). For each parameter, S-warfarin was significantly different from R-warfarin (P<0.05). Warfarin was absorbed rapidly after oral administration, and the dosage did not affect the time to maximum concentration (S:0.87, R:0.75 h). Oral dosage significantly influenced maximum plasma concentration (ng/mL, S:1267, R:1355 at 0.5 mg/kg; S:614.9, R:679.4 at 0.25 mg/kg; S:250.5, R:367.6 at 0.1 mg/kg), AUC (h*microg/mL, S:45.12, R:30.91 at 0.5 mg/kg; S:22.98:, R:18.99 at 0.25 mg/kg; S:3.922, R:3.570 at 0.1 mg/kg) and AUMC (h*h*microg/mL, S:2135, R:1062 at 0.5 mg/kg; S:943.1, R:599.9 at 0.25 mg/kg; S:132.2, R:59.03 at 0.1 mg/kg), but not t1/2 (S:23.5, R:11.6 h) nor MRT (S:26.3, R:13.5 h). Both warfarin enantiomers were highly (>96.5%) protein-bound. Quantitation of the warfarin content in commercially available tablets indicated an unequal distribution of the drug throughout the tablet.

Pharmacodynamics of warfarin in cats

The overall purpose of this study was to evaluate the pharmacodynamic response to warfarin in cats. The specific aim was to determine if a log-linear indirect response model (Nagashima et al., 1969) used to describe the in vivo effect of warfarin in humans could be applied to cats. The pharmacokinetics of racemic warfarin were described using a non-compartmental approach. The relationship between prothrombin complex activity (PCA) and normalized prothrombin time (PTR) was defined for feline plasma under our experimental conditions, and determined to be: %PCA=12.38+648 e-PTR/0.492. These data were then integrated and used to predict the warfarin dose associated with therapeutic anti-coagulation defined as an International Normalized Ratio (INR) of 2.0-3.0. The maximum prothrombinopenic response to warfarin in cats after a single intravenous dose of 0.5 mg/kg occurred at 24-48 h. Pharmacodynamic modeling suggested that each cat had a narrow therapeutic range of the steady-state concentration of total warfarin required to appropriately block prothrombin complex synthesis (median: 265.2-358.7 ng/mL). The median daily dose range predicted to yield therapeutic concentrations of warfarin was 0.061-0.088 mg/kg per day. Wide inter-individual variations in both pharmacokinetics and pharmacodynamic response suggest that a more optimal dosing of warfarin may be possible with the development of individual pharmacokinetic/pharmacodynamic algorithms, analogous to those currently employed in human patients.

Drug dependence, a chronic medical illness: implications for treatment, insurance, and outcomes evaluation

The effects of drug dependence on social systems has helped shape the generally held view that drug dependence is primarily a social problem, not a health problem. In turn, medical approaches to prevention and treatment are lacking. We examined evidence that drug (including alcohol) dependence is a chronic medical illness. A literature review compared the diagnoses, heritability, etiology (genetic and environmental factors), pathophysiology, and response to treatments (adherence and relapse) of drug dependence vs type 2 diabetes mellitus, hypertension, and asthma. Genetic heritability, personal choice, and environmental factors are comparably involved in the etiology and course of all of these disorders. Drug dependence produces significant and lasting changes in brain chemistry and function. Effective medications are available for treating nicotine, alcohol, and opiate dependence but not stimulant or marijuana dependence. Medication adherence and relapse rates are similar across these illnesses. Drug dependence generally has been treated as if it were an acute illness. Review results suggest that long-term care strategies of medication management and continued monitoring produce lasting benefits. Drug dependence should be insured, treated, and evaluated like other chronic illnesses. JAMA. 2000;284:1689-1695.

Access to narcotic addiction treatment and medical care: prospects for the expansion of methadone maintenance treatment

Methadone maintenance treatment (MMT) for opioid addiction is safe and effective but underutilized because of inaccessibility, under-financing and the stigma generally attached to maintenance therapies. In addition, cumbersome regulation of methadone prescription and treatment impedes the delivery of care and retards expansion of methadone maintenance into office practice settings. Exaggeration of the problem of methadone diversion further hinders development of MMT. Despite obstacles, methadone maintenance has been successfully expanded and extended into primary care settings abroad. Initial trials in the U.S. have shown that methadone maintenance in physician office-based settings yields positive results with some advantages over care in large methadone clinics. Alternatives to methadone, such as buprenorphine, are also being explored in primary care settings. With implementation of the NIH Consensus Statement on Effective Medical Treatment of Heroin Addiction, including training of primary care physicians, methadone maintenance treatment could reach many more patients, achieve higher success rates, and substantially reduce the deleterious effects of opioid addiction in the U.S.

Physician Leadership on National Drug Policy: advocacy for an effective drug policy

The founders of the PLNDP envisioned an active and committed group willing to tackle the potentially controversial area of national drug policy. The group already initiated a serious national debate about drug policy, inside and outside of the medical profession. Several national professional societies moved beyond their existing policies to embrace components of the PLNDP initiative. The group meets again in the summer of 1999 to share goals and articulate the next steps in research and advocacy. This meeting invites leaders in law, the enforcement community, legislators, community coalition leaders, and experts in addiction medicine and addiction psychiatry. PLNDP leaders expect that the subsequent coalitions will affect the course of discussion about the nation's drug policy far into the future.

Clinical and morphologic features of mucopolysaccharidosis type II in a dog: naturally occurring model of Hunter syndrome

A 5-year-old male Labrador Retriever had progressive incoordination, visual impairment, and exercise intolerance. Coarse facial features, macrodactylia, unilateral corneal dystrophy, generalized osteopenia, progressive neurologic deterioration, and a positive urine spot test for acid mucopolysaccharides suggested mucopolysaccharidosis. Intracytoplasmic vacuoles were most prevalent in epithelial cells, endothelial cells, and histiocytes of liver, kidney, thyroid gland, and spleen. Ultrastructural examination disclosed electron-lucent floccular to lamellar membrane-bound storage material characteristic of mucopolysaccharides. Periodic acid-Schiff-positive intracytoplasmic material was identified in multiple neurons in the medulla, pontine nucleus, cerebellum, and spinal gray matter horns. Biochemical assays identified a deficiency in iduronate-2-sulfatase (IDS) activity in cultured dermal fibroblasts compared with normal dogs. Hair root analysis for IDS showed that the dam was a carrier of X-linked Hunter syndrome and that a phenotypically normal male littermate of the affected dog was normal. This is the first report of Hunter syndrome or mucopolysaccharidosis type II in a dog.

Homotypic and heterotypic IgG and IgM antibody responses in adults infected with small round structured viruses

Antibody responses to recombinant Norwalk (rNV) and Mexico (rMXV) viral capsid proteins were studied in 39 adults involved in outbreaks of gastroenteritis associated with genogroup 2 small round structured viruses (SRSVs). Nineteen individuals were involved in outbreaks associated with MXV-like strains and 20 in outbreaks associated with four other genogroup 2 SRSVs. IgG antibodies were measured in acute and convalescent sera using indirect enzyme-linked immunosorbent assay (ELISA), and IgM was measured by indirect and capture ELISAs. Nineteen (49%) patients demonstrated a significant rise in IgG to rMXV with four (10%) patients also showing anamnestic responses to rNV. Fourteen patients were positive in the rMXV IgM-capture ELISA, representing 74% of patients demonstrating IgG rises. IgG and IgM responses to rMXV were observed in both groups, although higher levels of responses were seen in adults infected with MXV-like strains than those infected with non-MXV genogroup 2 viruses. No significant IgM responses were observed to rNV. These results indicate that, following SRSV infection, adults show a rise in antibody which is broadly reactive to viruses within but not between genogroups, although greater homotypic than heterotypic responses are produced. These findings have implications for interpretation of seroepidemiological studies and serodiagnosis of SRSV infections using recombinant capsids.

Thrombocytopenia in dogs with anticoagulant rodenticide-induced hemorrhage: eight cases (1990-1995)

Thrombocytopenia was documented in eight of 11 dogs with anticoagulant rodenticide-induced hemorrhage. Thrombocytopenia was transient and generally mild-to-moderate, but it became marked (i.e., less than 30,000 platelets/microl) in two cases. Petechial hemorrhages were not noted in any case. There was no relationship between hematocrit and platelet count. Platelet count changes in response to treatment with fresh-frozen plasma and isotonic electrolyte solutions were variable. Anticoagulant rodenticide toxicity should be included as a differential diagnosis for dogs with hemorrhage accompanied by mild-to-moderate thrombocytopenia.

The role of the generalist in the care of the substance-abusing patient

It will be some time before known effective practices on behalf of patients with ATOD problems are integrated into the mainstream of medical care. Ironically, much of the medical literature centers on the medical and psychiatric complications of substance abuse and on physician attitudes regarding treatment of these patients. Rather the focus should be on the ways in which physicians can intervene early and effectively to treat the substance abuse problem itself. Much of this issue serves to correct the imbalance.

Epidemiology of Mexico virus, a small round-structured virus in Yorkshire, United Kingdom, between January 1992 and March 1995

The epidemiology of the small round-structured virus, Mexico virus (MxV), was investigated in North and West Yorkshire, United Kingdom, between January 1992 and March 1995 using a type-specific antigen ELISA. The results indicate that an epidemic of MxV occurred during the winter of 1993-1994, when this strain was associated with 45 of 99 outbreaks and sporadic childhood cases of gastroenteritis. Only 4 MxV-like isolates were found during the 1992-1993 winter season and none in the 1994-1995 season. This descriptive epidemiologic study suggests that MxV has an epidemic pattern of infection.

Alcoholism in the elderly: physicians can make a difference

The prevalence of alcoholism among the elderly is significant. Drinking problems in the aged may be masked by a physical or psychological conditioning. Diagnosis can thus be difficult but once it is made, treatment is fairly standard.

Canine idiopathic thrombocytopenic purpura

Canine idiopathic thrombocytopenic purpura (ITP) is a disease in which antibodies bound to the surface of platelets mediate premature platelet destruction by macrophages. ITP in dogs and chronic ITP in humans are analogous diseases. This article draws on information from the literature on ITP in dogs and in humans, and reviews the pathogenesis, diagnosis, and treatment of ITP in dogs.

Studies of platelet-bound and serum platelet-bindable immunoglobulins in dogs with idiopathic thrombocytopenic purpura

Canine idiopathic thrombocytopenic purpura (ITP) is clinically analogous to chronic ITP in human beings. The objective of this study was to investigate the pathogenesis of canine ITP by determining whether immunoglobulins bound to the surface of platelets from dogs with ITP (platelet-bound immunoglobulins) were directed against host platelet antigen and whether platelet glycoproteins (GP) IIb and IIIa were target antigens in dogs with ITP. Thirty-two dogs with ITP were studied. Increased platelet-bound immunoglobulin concentrations were detected in 30 cases (94%), and increased concentrations of serum platelet-bindable immunoglobulins were detected in 11 cases (34%). Immunoglobulins eluted from the surface of platelets from dogs with ITP bound to homologous normal canine platelets in 11 of 19 cases (58%). Immunoglobulins against platelet membrane GP IIb and/or IIIa were detected in serum from four of 17 affected dogs. This study provides evidence that immunoglobulins bound to surface of platelets from some dogs with ITP are directed against host platelet antigens and that platelet target antigens are, in some cases, GP IIb and IIIa. This supports the hypothesis that canine ITP is an autoimmune disease, similar to the pathogenesis of chronic ITP in human beings.

The role of internal medicine in addiction medicine

Internal Medicine must play an important role in addiction medicine. Although Psychiatry has been the dominant discipline in the addictions field, this article explores how the internist can bring special insight to the understanding of addictions. The article documents how Internal Medicine, historically, has helped define and diversify the field of addiction medicine. A survey of recent history, however, shows that Internal Medicine has only minimally broadened its role in the addiction field, despite the pronouncements of numerous committees, despite the urging of several medical groups that it do so. The article shows that some internists want to play an increased role in the field of addiction medicine, but often feel limited by their lack of knowledge and by the professional biases they confront. In conclusion, new suggestions for improving internist education and increasing their interest and participation in addiction medicine are offered.

Critical plant and seed concentrations of phosphorus and zinc for predicting response of faba beans (Vicia faba)

Faba beans (Vicia faba cv. Fiord) were grown in 1 glasshouse and 3 field experiments to calibrate the critical concentrations of phosphorus (P) and zinc (Zn) in selected plant tissues for vegetative and grain yields. In the field experiments, responses in grain yield to soil-applied P were between 0.5 and 0.8 t/ha (20-25%) at sites with extractable Colwell soil P concentrations of 20 and 23 mg/kg. Similarly, grain yields were increased by 0.6-1.2 t/ha (20-30%) from the application of either soil-applied or foliar Zn. These field responses to Zn only occurred if P fertiliser was applied at sowing. Maximum yields were obtained by either applying about 2 kg Zn/ha to the soil at sowing, or 500 g Zn/ha as a foliar spray, 8 weeks after sowing. In field experiments, critical P concentrations in the youngest open leaf during vegetative growth for prediction of maximum grain yield in the field, remained constant over a 10-week growing period. A critical nutrient range of 0.40-0.41% is proposed. However, critical concentrations of P in whole top for maximum grain yield, declined from 0.40 to 0.27% over the same growing period. For bean seed collected at harvest, a critical concentration of 0.36% P for maximum grain yield was derived. Critical concentrations of Zn during vegetative growth for prediction of maximum grain yield, derived in both glasshouse and field experiments, were very similar in youngest open leaf and whole top, and no significant decline with plant age was observed; a critical nutrient range of 19-24 mg/kg is proposed. For seed collected at harvest, a critical nutrient range for diagnosis of Zn deficiency of 13-15 mg/kg is suggested.

Development and characterization of a flow cytometric assay for detection of platelet-bound immunoglobulin G in dogs

OBJECTIVE

To develop a flow cytometric assay for detection of platelet-bound IgG in dogs.

SAMPLE POPULATION

Negative-control platelets were obtained from 5 clinically normal Greyhounds. Positive-control platelets were platelets from 1 clinically normal dog, sensitized with dog anti-canine platelet alloantibodies.

PROCEDURE

Washed platelets were incubated with mouse anti-canine IgG conjugated to fluorescein isothiocyanate and analyzed by flow cytometry. Optimal dilution of antibody reagent and dose-response were determined, as were effects on platelet-bound IgG detection of storage time and temperature of K3EDTA-anticoagulated blood samples, variable platelet numbers, and variable filling of K3EDTA evacuated tubes.

RESULTS

A 1:128 dilution of antibody reagent was optimal. There was a linear increase in platelet-bound IgG when normal canine platelets were incubated with increasing concentrations of positive-control serum. Variable numbers of positive-control platelets tested and variable filling of K3EDTA evacuated tubes had no significant effect on platelet-bound IgG concentration. Platelet-bound IgG concentration increased with storage time at room temperature (P = 0.0003), but not when blood was kept cool. Sufficient platelets for assay were able to be isolated from 3 ml of blood from 5 dogs with < 10,000 platelets/microliters.

CONCLUSIONS

This assay for platelet-bound IgG in dogs is simple, repeatable, and practical. The assay is not affected by platelet count or variable filling of evacuated tubes, and requires only 3 ml of K3EDTA-anticoagulated blood. Blood samples for testing require packaging on ice and overnight delivery but, after arrival at the laboratory, can be refrigerated and analyzed within 72 hours of collection.

CLINICAL RELEVANCE

Assays for platelet-bound IgG may help in assessing causes and treatment of thrombocytopenia.

Successful treatment of regional enteritis in a dog

Regional enteritis was diagnosed in an 11-year-old, spayed female German shepherd dog with a history of intermittent vomiting and anorexia. Segmental, transmural granulomatous enteritis involved the pylorus, jejunum, and ileum. The jejunal lesions were excised. The remaining lesions completely resolved subsequent to long-term prednisone and sulfasalazine therapy.

Detection and differentiation of antigenically distinct small round-structured viruses (Norwalk-like viruses) by reverse transcription-PCR and southern hybridization

Application of reverse transcription (RT)-PCR to detect small round-structured viruses (SRSVs) from fecal specimens of patients with gastroenteritis has been insensitive because of the tremendous sequence heterogeneity between strains. We have designed two RT-PCR primer sets (G-1 and G-2) based on the nucleotide sequence diversity in the RNA polymerase gene of SRSVs belonging to two distinct genogroups represented by Norwalk virus (primers G-1) and Snow Mountain agent (primers G-2). All 22 SRSV strains examined that had been classified previously by solid-phase immune electron microscopy into four antigenic types (UK1, UK2, UK3, and UK4) could be detected by RT-PCR with these two primer sets. The G-1 primer set detected 6 UK2 strains, and the G-2 primers detected 16 strains, including 7 UK1, 5 UK3, and 4 UK4 strains. On the basis of nucleotide sequences of 81-bp fragments of the RT-PCR products from 13 strains determined in this study, together with those previously reported for 17 SRSV strains, we designed four sets of internal oligonucleotide probes (P1-A, P1-B, P2-A, and P2-B) for Southern hybridization, using chemiluminescent detection. The P1-A probe hybridized with PCR products from the UK2 strains; the P1-B probe, with products from two of the seven UK1 strains; the P2-A probe, with four of the remaining five UK1 strains; and the P2-B probe, with products from both UK3 and UK4 strains, as well as with one strain originally typed as UK1 which showed cross-reactivity with UK4 upon retesting by solid-phase immune electron microscopy. RT-PCR with both the G-1 and the G-2 primer sets can increase the detection rate of the many antigenically distinct SRSVs and, when combined with Southern hybridization, may predict the antigenic type of the SRSV associated with infection.

An appraisal of soil phosphorus testing data for crops and pastures in South Australia

Data from more than 580 field experiments conducted in South Australia over the past 30 years have been re-examined to estimate extractable soil phosphorus (P) levels related to 90% maximum yield (C90) for 7 crop species (wheat, barley, oilseed rape, sunflower, field peas, faba beans, potato) and 3 types of legume-based pasture (subterranean clover, strawberry clover, annual medics). Data from both single-year and longer term experiments were evaluated. The C90 value for each species was derived from the relationship between proportional yield responsiveness to applied P fertiliser rates (determined as grain yield in crops and herbage yield in ungrazed pastures) and extractable P concentrations in surface soils sampled before sowing. Most data assessments involved the Colwell soil P test and soils sampled in autumn to 10 cm depth. When all data for a species were considered together, the relationship between proportional yield response to applied P and soil P status was typically variable, particularly where Colwell soil P concentration was around C90. When data could be grouped according to common soil types, soil surface texture, or P sorption indices (selected sites), better relationships were discerned. From such segregated data sets, different C90 estimates were derived for either different soil types or soil properties. We recommend that site descriptors associated with the supply of soil P to plant roots be determined as a matter of course in future P fertiliser experiments in South Australia. Given the above, we also contend that the Colwell soil P test is reasonably robust for estimating P fertiliser requirements for the diverse range of soils in the agricultural regions of the State. In medium- and longer term experiments, changes in Colwell soil P concentration were measured in the absence or presence of newly applied P fertiliser. The rate of change (mg soil P/kg per kg applied P/ha) appeared to vary with soil type (or soil properties) and, perhaps, cropping frequency. Relatively minor changes in soil P status were observed due to different tillage practices. In developing P fertiliser budgets, we conclude that a major knowledge gap exists for estimating the residual effectiveness of P fertiliser applied to diverse soil types under a wide range of South Australian farming systems.

Detection of platelet-bound and serum platelet-bindable antibodies for diagnosis of idiopathic thrombocytopenic purpura in dogs

The sensitivity and specificity of 2 antibody tests for diagnosis of idiopathic thrombocytopenic purpura (ITP) in dogs were investigated prospectively. An ELISA to detect antibodies bound to the surface of platelets from affected dogs (direct test) was performed in 34 dogs with a clinical diagnosis of ITP and in 21 dogs with thrombocytopenia attributable to other causes. An ELISA to detect platelet-bindable antibodies in serum from affected dogs (indirect test) was performed in 32 dogs with ITP and in 15 dogs with other causes of thrombocytopenia. The direct test was positive in 32 of 34 dogs with ITP (sensitivity, 94%) and negative in 13 of 21 dogs with other causes of thrombocytopenia (specificity, 62%). Positive direct test results were obtained in 2 dogs with systemic lupus erythematosus, and in 1 dog each with concurrent Ehrlichia canis and Babesia canis infections, dirofilariasis, myelodysplasia, disseminated intravascular coagulation (of unknown cause), and thrombocytopenia subsequent to administration of trimethoprim/sulfadiazine, as well as in 1 dog with thrombocytopenia 14 days after a whole blood transfusion. The indirect test had positive results in 11 of 32 dogs with ITP (sensitivity, 34%) and negative results in 12 of 15 dogs with other causes of thrombocytopenia (specificity, 80%). Positive indirect test results were obtained in 1 dog each with systemic lupus erythematosus, concurrent E canis and B canis infections, and thrombocytopenia subsequent to administration of trimethoprim/sulfadiazine. Detection of platelet-bound antibodies was more sensitive than detection of serum-platelet bindable antibodies in confirming a diagnosis of ITP in dogs.(ABSTRACT TRUNCATED AT 250 WORDS)

Effect of anticoagulant and blood storage time on platelet-bound antibody concentrations in clinically normal dogs

A solid-phase ELISA to detect antibodies bound to the surface of canine platelets (platelet-bound antibodies) is described. Using this assay, the effect of anticoagulant and storage time of anticoagulant blood on the concentration of antibodies bound to the surface of platelets from clinically normal dogs was investigated. Blood from 3 clinically normal dogs was anticoagulated with acid citrate dextrose, Na3 citrate, and aqueous K3 EDTA and stored on ice for up to 48 hours. Platelet-bound antibody concentration was measured on platelets isolated from anticoagulated blood immediately after venipuncture and subsequent to storage of blood for 24 and 48 hours. Differences in platelet-bound antibody concentrations were investigated among dogs, anticoagulants, and storage times by ANOVA and Bonferroni pair-wise comparison of means. There was no effect of dog on platelet-bound antibody concentration. The effect of time was significant (P < 0.0001), with higher concentration of platelet-bound antibodies detected with increasing storage time. Effect of anticoagulant on platelet-bound antibody concentration was not statistically significant; however, there was a trend to increasing concentration of antibodies bound to platelets isolated from Na3 citrate- and K3 EDTA-anticoagulated blood. Moreover, there was significant (P = 0.02) interaction between anticoagulant and time. Platelet-bound antibody concentration increased with storage of anticoagulated blood prior to platelet isolation and with use of Na3 citrate and K3 EDTA anticoagulants. The preferred anticoagulant for platelet-bound antibody measurement is acid citrate dextrose. Platelet-bound antibody concentration should be determined not longer than 24 hours after blood collection.

Characterization of a variant strain of Norwalk virus from a food-borne outbreak of gastroenteritis on a cruise ship in Hawaii

A gastroenteritis outbreak affecting at least 217 (41%) of 527 passengers on a cruise ship was caused by a variant strain of Norwalk virus (NV) that is related to but distinct from the prototype NV strain. Consumption of fresh-cut fruit served at two buffets was significantly associated with illness (P < or = 0.01), and a significant dose-response relationship was evident between illness and the number of various fresh-cut fruit items eaten. Seven (58%) of 12 paired serum specimens from ill persons demonstrated at least fourfold rises in antibody response to recombinant NV capsid antigen. A 32-nm small round-structured virus was visualized by electron microscopy in 4 (29%) of 14 fecal specimens, but none of the 8 specimens that were examined by an enzyme immunoassay for NV antigen demonstrated antigen. Four (40%) of 10 fecal specimens were positive by reverse transcriptase-PCR by using primer pairs selected from the polymerase region of NV. In a 145-bp region, the PCR product shared only 72% nucleotide sequence identity with the reference NV strain and 77% nucleotide sequence identity with Southampton virus but shared 95% nucleotide sequence identity with UK2 virus, a United Kingdom reference virus strain. In addition, the outbreak virus was serotyped as UK2 virus by solid-phase immune electron microscopy. The genetic and antigenic divergence of the outbreak strain from the reference NV strain highlights the need for more broadly reactive diagnostic assays and for improved understanding of the relatedness of the NV group of agents.

Comparison of the polymerase region of small round structured virus strains previously classified in three antigenic types by solid-phase immune electron microscopy

We have used a reverse transcription-polymerase chain reaction with nested sets of primers to determine the nucleotide sequences of a 166 base pair segment of the RNA polymerase region of seven strains of small round structured viruses (SRSVs) from the United Kingdom. These SRSV strains were previously classified by solid-phase immune electron microscopy into three antigenic types--UK2, UK3 and UK4, which are comparable to the prototype strains Norwalk virus, Hawaii agent, and Snow Mountain agents, respectively. Based on their sequences, the seven strains from the United Kingdom could be divided into two groups. The first group included two strains of the UK2 type along with Norwalk virus and Southampton virus and the second group included three strains of UK3 and two strains of UK4 types. Viruses in the first group showed 75.3%-77.1% nucleotide and 89.1%-94.6% amino acid identity with Norwalk virus while those of the second group showed 60.8%-63.3% nucleotide and 67.3%-69.1% amino acid identity. Nucleotide and amino acid identity within the second group ranged between 91.6%-99.4% and 96.4%-100%, respectively. These results suggest that the SRSVs antigenically related with Norwalk virus, Hawaii agent, and Snow Mountain agent, can be classified into two genotypes on the basis of their sequences in the RNA polymerase region.

Estimation of potential health effects from acute exposure to hydrogen fluoride using a "benchmark dose" approach

Communities across the United States are examining the manufacture, use, transport, and storage of hydrogen fluoride (HF) near residential areas as a consequence of a major release of HF in Texas in 1987. Reference exposure levels for routine and accidental HF emissions are calculated using existing animal and human data. The approach employs a log-probit extrapolation of concentration-response data to the 95% lower confidence limit on the toxic concentration producing a "benchmark dose" of 1% response (TC01), called a practical threshold. Species-specific and chemical-specific adjustment factors are applied to develop exposure levels applicable to the general public. Using this method, the 1-hr reference exposure level to protect the public against any irritation from a routine emission (REL-1) is 0.7 ppm and the level to protect against severe irritation from a once-in-a-lifetime (REL-2) release is 2 ppm. This approach is compared to a modified "uncertainty factor" approach.

Pneumothorax in polysubstance-abusing marijuana and tobacco smokers: three cases

Three patients are reported who suffered spontaneous pneumothorax, each of whom also had a history of daily marijuana and tobacco use. The patients ranged in age from 24 to 37 years, had smoked marijuana on a daily basis for 10 to 14 years, and had 11 to 50 pack-year tobacco-smoking histories. Marijuana may predispose to pneumothorax both by accelerating tobacco-induced lung disease, and by the frequent performance of the Valsalva maneuver during marijuana smoking. Although there is an association between pneumothorax and heavy tobacco use, an association with chronic daily marijuana use has not previously been reported.

Factors affecting the interpretation and adoption of plant analysis services

A review of the factors affecting the interpretation of plant analysis is presented. The development of plant test criteria is discussed in relation to plant part and age, seasonal nutrient changes, diurnal trends, Piper-Steenbjerg curvature, nutrient interaction and ratios, plant genotype, and environmental and crop management factors. The value of both diagnostic and prognostic plant tests is reviewed with specific emphasis on the role of prognostic tests in farmer decision making. Rapid sap testing is discussed in relation to development, utilisation, and role in agriculture. Factors affecting the utilisation of plant testing are reviewed. Within Australia the use of plant analysis services is low. Reasons for this low adoption and methods by which usage can be increased are discussed.

Open or transurethral surgery for the large prostate gland

A comparative study of transurethral (TUR) and open prostatectomy for the large prostate gland has been carried out. Over a 5-year period 94 transurethral resections and 73 open procedures were performed for prostate glands weighing more than 50 g. There was a single death in each group, giving relative mortality rates of 1.1% TUR and 1.4% open. The post-operative hospital stay was significantly shorter in the TUR group. The open group suffered significantly more complications in the first week but the TUR patients, although having fewer immediate postoperative complications, had significantly more in the first year, so that overall complication rates were similar (35% vs 36%). Patient satisfaction was equal in both groups.

Effect of plant age on the critical inorganic and total phosphorus concentrations in selected tissues of subterranean clover (cv. Trikkala)

Subterranean clover (cv. Trikkala) was grown in field and glasshouse experiments to calibrate the critical concentrations of inorganic P in selected plant tissues, for maximizing vegetative growth. Critical concentrations of total P in the various tissues were also calibrated from the field experiment. Critical concentrations of inorganic P derived in the glasshouse, for both youngest open leaf (YOL) and next oldest leaf (YOL+1), were similar at any one sampling time, but declined markedly with plant age, i.e. critical concentrations for YOL declined from 196 mg kg-1 at the first sampling to 96 mg kg-1 1 month later. Similarly, critical inorganic P concentrations for YOL derived in the field declined with time, i.e. from 187 mg kg-1 to 124 mg kg-1 from the first to second sampling. Critical inorganic P concentrations for YOL+1 were less age dependent, though much lower at any one sampling time. As such, inorganic P is not recommended for diagnostic laboratory use. Critical concentrations of total P for YOL and YOL+1 did not decline significantly over the sampling period, while those for whole plant tops (WT) declined from 0.35 to 0.30% over the same period. In the YOL tissue, the proposed critical nutrient range for total P is 0.40-0.45% while that for WT, sampled early in the growing season, is 0.35-0.40%. Results from this study support the use of total P in diagnostic plant testing services.

Benzodiazepine requirements during alcohol withdrawal syndrome: clinical implications of using a standardized withdrawal scale

An accurate characterization of the severity of the alcohol withdrawal syndrome is likely to provide clear guidelines for drug therapy in this disorder. We studied (retrospectively) the usefulness of a standardized withdrawal scale on benzodiazepine drug requirements for patients undergoing alcohol detoxification in a general hospital. One hundred thirty-three patients received the revised Clinical Institute withdrawal Assessment Scale for Alcohol and were medicated only if the score was greater than 10. A comparison group of 117 patients was treated without reference to the scale. The groups were evenly matched with respect to age, sex, concurrent drug use, and laboratory abnormalities. Subjects treated according to the scale required less benzodiazepine (median dose, 50 mg diazepam equivalent compared with 75 mg) (p = 0.04). Rates of complications, discharge against medical advice, and length of stay did not differ between the groups. Rank correlation coefficients revealed a closer relationship between the degree of alcohol exposure (as determined by admitting blood alcohol levels, creatine phosphokinase, and SGOT) and benzodiazepine requirements during withdrawal for the group treated with the scale. Findings suggest that when the scale is used, patients with a greater degree of physical dependence receive (appropriately) a higher dose of benzodiazepine and those with a lesser degree of dependence receive (appropriately) a lower dose of benzodiazepine. Use of the scale appears to minimize both under- and overdosing with benzodiazepine for alcohol withdrawal syndrome.

Medical education for alcohol and other drug abuse in the United States

Initiatives by individuals, private foundations and government have led to improvements in the United States in medical education dealing with alcohol and drug-related problems. Progress has been made, particularly in the past 5 years, in developing new medical school curricula and in faculty development. Greater activity by national professional organizations has helped raise the priority of training in alcohol- and drug-related areas for undergraduate and postgraduate medical education. As an example, Project ADEPT (Alcohol and Drug Education for Physician Training in primary care) at Brown University in Providence, Rhode Island, is described. The importance of positive and motivated faculty role models and of skills training is emphasized.