Stress reactivity of the brain noradrenergic system in three rat strains differing in their neuroendocrine and behavioral responses to stress: implications for susceptibility to stress-related neuropsychiatric disorders

The brain noradrenergic system is activated by stress, modulating the activity of forebrain regions involved in behavioral and neuroendocrine responses to stress. In this study, we characterized brain noradrenergic reactivity to acute immobilization stress in three rat strains that differ in their neuroendocrine stress response: the inbred Lewis (Lew) and Wistar-Kyoto (WKY) rats, and outbred Sprague-Dawley (SD) rats. Noradrenergic reactivity was assessed by measuring tyrosine hydroxylase mRNA expression in locus coeruleus, and norepinephrine release in the lateral bed nucleus of the stria terminalis. Behavioral measures of arousal and acute stress responsivity included locomotion in a novel environment, fear-potentiated startle, and stress-induced reductions in social interaction and open-arm exploration on the elevated-plus maze. Neuroendocrine responses were assessed by plasma adrenocorticotropic hormone. Compared to SD, adrenocorticotropic hormone responses of Lew rats were blunted, whereas those of WKY were enhanced. The behavioral effects of stress were similar in Lew and SD rats, despite baseline differences. Lew had similar elevations of tyrosine hydroxylase mRNA, and initially greater norepinephrine release in the lateral bed nucleus of the stria terminalis during stress, although both noradrenergic responses returned toward baseline more rapidly than in SD rats. WKY rats showed depressed baseline startle and lower baseline exploratory and social behavior than SD. However, unlike the Lew or SD rats, WKY exhibited a lack both of fear potentiation of the startle response and of stress-induced reductions in exploratory and social behavior, indicating attenuated stress responsivity. Acute noradrenergic reactivity to stress, measured by either tyrosine hydroxylase mRNA levels or norepinephrine release, was also attenuated in WKY rats. Thus, reduced arousal and behavioral responsivity in WKY rats may be related to deficient brain noradrenergic reactivity. This deficit may alter their ability to cope with stress, resulting in the exaggerated neuroendocrine responses and increased susceptibility to stress-related pathology exhibited by this strain.

Diversity Among Strains of Xanthomonas campestris pv. vitians from Lettuce

ABSTRACT Diversity in host range, pathogenicity, phenotypic characteristics, repetitive extragenic palindromic polymerase chain reaction (rep-PCR) profiles, and sequence of the 16S-23S rDNA spacer region was examined among 44 Xanthomonas strains isolated from lettuce. Forty-two of the strains were divided into two groups, designated A and B. Seventy percent were Group A, and most of the remaining strains including a reference strain (LMG 938) were Group B. Group A strains induced both local and systemic symptoms, whereas Group B strains caused only distinct necrotic spots. Two strains, including the X. campestris pv. vitians type strain, were distinct from the Group A and B strains and were not pathogenic on lettuce. Analysis of fatty acid profiles, serotype, carbon substrate utilization patterns, and protein fingerprints confirmed this grouping. The Group A and B strains also formed two unique clusters (I and II) by rep-PCR profiling that corresponded to the two groups. Direct sequencing of a PCR-amplified DNA fragment (680 bp) from the 16S-23S rDNA spacer region of four representative strains, however, did not differentiate these groups. Serology and rep-PCR fingerprinting can be used to diagnose and identify X. campestris pv. vitians strains, while the other analyses evaluated are useful for strain characterization.

Effect of Rice Root-Knot Nematode on Growth and Yield of Yellow Granex Onion

Rice root-knot nematode, Meloidogyne graminicola, infects all commercially grown onion cultivars in rice-onion cropping systems in the Philippines, but its economic importance has not been established. The effects of different preplant population levels (Pi) of M. graminicolaon Yellow Granex onion in pots and of different percentages of galled roots in a naturally infested field were evaluated. Leaf weight and root length of 'Yellow Granex 429' seedlings decreased with increasing Pi, while low Pi mildly stimulated plant height at the vegetative growth stage. Age of transplant and Pi influenced growth and yield of onion at maturity. Onion yield and root and leaf weights decreased as the age of the transplants increased. Growth and yield decreased with increased Pi. Bulb weight was reduced by 7 to 82% and diameter by 10 to 62% when plants were inoculated with 50 to 10,000 second-stage juveniles. Onion bulbs from the field were reduced by 16, 32, and 35% in weight and by 6, 17, and 18% in diameter when the percentage of roots galled was 10, 50, and 100%, respectively. Management of M. graminicolapopulations at the start of the growing season must be part of onion culture in rice-onion systems to reduce onion yield losses and to prevent economic loss.

Integrating evidence-based decision making into allied health curricula

An evidence-based approach may decrease variations in practice and time delays in adopting new procedures. This report describes the process for incorporating evidence-based decision making (EBDM) into curricula using active teaching techniques. The process centers on a national four-day Faculty Development Institute (FDI) program for dental hygiene, occupational therapy, and physical therapy faculty. Phase I assesses pre-Institute EBDM knowledge, skills, and teaching strategies. Phase II, onsite, involves learning EBDM principles and teaching skills and developing an educational package. Phase III integrates these into the curriculum, with ongoing follow-up. At baseline, faculty were unfamiliar with EBDM but were incorporating related skills. Formulation of questions and evidence gathering for patient-care decisions were weak. Phase II follow-up showed a significant increase in EBDM knowledge, p < 0.001, and 100% agreed or strongly agreed that they were prepared to integrate EBDM into their courses; 93% felt better prepared to use EBDM. Curricula and educational experiences need to include EBDM skills. The three-phase process can support faculty in making needed changes.

Report of Bacterial Leaf Spot on Collards and Turnip Leaves in Ohio

In 2000, circular water-soaked lesions typical of bacterial leaf spot were observed on leaves of collards (Brassica oleracea L. var. viridis) throughout commercial fields in northwest Ohio. Light brown, rectangular, water-soaked lesions were observed on turnip leaves (Brassica rapa L.). Bacterial streaming from lesions on both crops was observed microscopically. Cream colored, fluorescent colonies were isolated from diseased tissues on Pseudomonas F medium, and eight representative colonies (four from collards and four from turnip) were selected and purified. Fatty acid methyl ester analysis was performed on all of the isolates. Two from collards and two from turnip were identified as Pseudomonas syringae pv. maculicola (mean similarity index = 0.82 [MIDI Inc., Newark, DE]). DNA extracts from pure cultures of the P. syringae pv. maculicola strains were used as template in a polymerase chain reaction (PCR) assay with primers derived from the region of the coronatine gene cluster controlling synthesis of the coronafacic acid moiety found in P. syringae pv. tomato and P. syringae pv. maculicola (CorR and CorF2) (D. Cuppels, personal communication). DNA from P. syringae pv. tomato strain DC3000 and P. syringae pv. maculicola strain 88-10 (2) served as positive controls, while water and DNA from Xanthomonas campestris pv. vesicatoria strain Xcv 767 were used as negative controls. The expected 0.65-kb PCR product was amplified from three of four strains (two from turnip and one from collards) and the positive control DNA, but not from the negative controls. Pathogenicity tests were performed twice on 6-week-old turnip ('Forage Star', 'Turnip Topper', 'Turnip Alamo', 'Turnip 7'), collard ('Champion') and mustard (Brassica juncea L. 'Southern Giant Curl') seedlings using the three PCR-positive strains. Premisted seedlings were spray-inoculated separately with each of the three strains (2 × 10⁸ CFU/ml, 5 ml per plant) and a water control. Greenhouse temperatures were maintained at 20 ± 1°C. For both tests, all strains caused characteristic lesions on all of the crucifer cultivars within 5 days after inoculation; the control plants did not develop symptoms. To satisfy Koch's postulates, one of the turnip strains was reisolated from 'Turnip Topper' plants, and the collard strain was reisolated from 'Champion' plants. The three original and two reisolated strains induced a hypersensitive response in Mirabilis jalapa L. and Nicotiana tabacum L. var. xanthia plants 24 h after inoculation with a bacterial suspension (1 × 10⁸ CFU/ml). The original and reisolated strains were compared using rep-PCR with the primer BOXA1R (1). The DNA fingerprints of the reisolated strains were identical to those of the original strains. To our knowledge, this is the first report of bacterial leaf spot on commercially grown collards and turnip greens in Ohio. References: (1) B. Martin et al. Nucleic Acids Res. 20:3479, 1992. (2) R. A. Moore et al. Can. J. Microbiol. 35:910, 1989.

Effect of Compost Amendments on Disease Severity and Yield of Tomato in Conventional and Organic Production Systems

Field trials were conducted over 2 years to assess the effects of compost amendments on disease development in organic and conventional processing tomato (Lycopersicon esculentum L.) production systems. The incidence of anthracnose fruit rot was reduced in organic tomato plots amended with a high rate of composted cannery wastes compared with the incidence in nonamended control plots in 1998 when disease incidence was high. Marketable yield was increased by 33% in compost-amended organic plots. Plots amended with a high compost rate had more ripe fruit than the nonamended control. The incidence of anthracnose and of total disease on fruit was less on the cultivar OH 8245 than on Peto 696. Total fruit yield of OH 8245 but not Peto 696 in organic plots was increased by amendment with composted cannery wastes. In conventional tomato production, composted yard wastes increased disease severity on foliage both years but reduced bacterial spot incidence on fruit in 1997, when disease pressure was high. The incidence of anthracnose was not affected by composted yard wastes. Marketable and total fruit yields of Peto 696 were not increased in compost-amended conventional plots. The plant activator Actigard reduced foliar disease severity and the incidence of bacterial spot and anthracnose on fruit, while increasing yield of marketable fruit.

Electroosmotic flow in template-prepared carbon nanotube membranes

Carbon nanotube membranes (CNMs) were prepared by doing chemical vapor deposition of carbon within the pores of a microporous alumina template. Electroosmotic flow (EOF) was driven across the CNMs by allowing the membrane to separate two electrolyte solutions and using an electrode in each solution to pass a constant ionic current through the nanotubes. EOF was investigated by measuring the flux of a probe molecule (phenol) across the CNM. The as-synthesized CNMs have anionic surface charge, and EOF is in the direction of cation migration across the membrane. Measurements of the rate of EOF as a function of applied transmembrane current provided the zeta potential. The effect of pH on zeta provided the pK(a) for the surface acidic sites responsible for this anionic charge; the acidic-site density was also determined. An electrochemical derivatization method was used to attach carboxylate groups to the nanotube walls; this enhances the anionic surface charge density, resulting in a corresponding increase in the EOF rate. Electrochemical derivatization was also used to attach cationic ammonium sites to the nanotube walls to yield CNMs that show EOF in the opposite direction of the as-synthesized or carboxylated membranes.

A conserved subtilisin-like protein TgSUB1 in microneme organelles of Toxoplasma gondii

Proteolytic processing plays a significant role in the process of invasion by the obligate intracellular parasite Toxoplasma gondii. We have cloned a gene, TgSUB1, encoding for a subtilisin-type serine protease found in T. gondii tachyzoites. TgSUB1 protein is homologous to other Apicomplexan and bacterial subtilisins and is processed within the secretory pathway of the parasite. Initial cleavage occurs in the endoplasmic reticulum, after which the protein is transported to micronemes, vesicles that secrete early during host cell invasion. Upon stimulation of microneme secretion, TgSUB1 is cleaved into smaller products that are secreted from the parasite. This secondary processing is inhibited by brefeldin A and serine protease inhibitors. TgSUB1 is a candidate processing enzyme for several microneme proteins cleaved within the secretory pathway or during invasion.

Phenolic anti-inflammatory antioxidant reversal of Abeta-induced cognitive deficits and neuropathology

Both oxidative damage and inflammation have been implicated in age-related neurodegenerative diseases including Alzheimer's Disease (AD). The yellow curry spice, curcumin, has both antioxidant and anti-inflammatory activities which confer significant protection against neurotoxic and genotoxic agents. We used 22 month Sprague-Dawley (SD) rats to compare the effects of the conventional NSAID, ibuprofen, and curcumin for their ability to protect against amyloid beta-protein (Abeta)-induced damage. Lipoprotein carrier-mediated, intracerebroventricular infusion of Abeta peptides induced oxidative damage, synaptophysin loss, a microglial response and widespread Abeta deposits. Dietary curcumin (2000 ppm), but not ibuprofen, suppressed oxidative damage (isoprostane levels) and synaptophysin loss. Both ibuprofen and curcumin reduced microgliosis in cortical layers, but curcumin increased microglial labeling within and adjacent to Abeta-ir deposits. In a second group of middle-aged female SD rats, 500 ppm dietary curcumin prevented Abeta-infusion induced spatial memory deficits in the Morris Water Maze and post-synaptic density (PSD)-95 loss and reduced Abeta deposits. Because of its low side-effect profile and long history of safe use, curcumin may find clinical application for AD prevention.

Estrogen (E2) and glucocorticoid (Gc) effects on microglia and A beta clearance in vitro and in vivo

The accumulation of fibrillar aggregates of beta Amyloid (A beta) in Alzheimer's Disease (AD) brain is associated with chronic brain inflammation. Although activated microglia (mu glia) can potentially clear toxic amyloid, chronic activation may lead to excessive production of neurotoxins. Recent epidemiological and clinical data have raised questions about the use of anti-inflammatory steroids (glucocorticoids, Gcs) and estrogens for treatment or prevention of AD. Since very little is known about steroid effects on mu glial interactions with amyloid, we investigated the effects of the synthetic Gc dexamethasone (DXM) and 17-beta estradiol (E2) in vitro in a murine mu glial-like N9 cell line on toxin production and intracellular A beta accumulation. To determine whether the steroid alterations of A beta uptake in vitro had relevance in vivo, we examined the effects of these steroids on A beta accumulation and mu glial responses to A beta infused into rat brain. Our in vitro data demonstrate for the first time that Gc dose-dependently enhanced mu glial A beta accumulation and support previous work showing that E2 enhances A beta uptake. Despite both steroids enhancing uptake, degradation was impeded, particularly with Gcs. Distinct differences between the two steroids were observed in their effect on toxin production and cell viability. Gc dose-dependently increased toxicity and potentiated A beta induction of nitric oxide, while E2 promoted cell viability and inhibited A beta induction of nitric oxide. The steroid enhancement of mu glial uptake and impedence of degradation observed in vitro were consistent with observations from in vivo studies. In the brains of A beta-infused rats, the mu glial staining in entorhinal cortex layer 3, not associated with A beta deposits was increased in response to A beta infusion and this effect was blocked by feeding rats prednisolone. In contrast, E2 enhanced mu glial staining in A beta-infused rats. A beta-immunoreactive (ir) deposits were quantitatively smaller, appeared denser, and were associated with robust mu glial responses. Despite the fact that steroid produced a smaller more focal deposit, total extracted A beta in cortical homogenate was elevated. Together, the in vivo and in vitro data support a role for steroids in plaque compaction. Our data are also consistent with the hypothesis that although E2 is less potent than Gc in impeding A beta degradation, long term exposure to both steroids could reduce A beta clearance and clinical utility. These data showing Gc potentiation of A beta-induced mu glial toxins may help explain the lack of epidemiological correlation for AD. The failure of both steroids to accelerate A beta degradation may explain their lack of efficacy for treatment of AD.

Pain management at the end of life

Pain is a common finding in dying patients. Most patients who experience pain at the end of their lives can have their pain effectively treated by their primary care physicians. The key to pain management is good pain assessment and a working familiarity with pain medications. Opioids are particularly important, and primary care physicians should be comfortable in prescribing these medications and should be familiar with appropriate dosing regimens. Clinical and ethical concerns regarding the use of opioids are overestimated, and opioids can be used safely in most pain management situations.

The effect of cytokine gene polymorphisms on pediatric heart allograft outcome

BACKGROUND

Cytokines play a major role in the inflammatory and immune responses that mediate allograft outcome. Several studies have shown that the production of cytokines varies among individuals and these variations are determined by genetic polymorphisms, most commonly within the regulatory region of the cytokine gene. The aim of this study was to assess the effect of these allelic variations on acute rejection after pediatric heart transplantation.

METHODS

We performed cytokine genotyping using polymerase chain reaction-sequence specific primers in 93 pediatric heart transplant recipients and 29 heart donors for the following functional polymorphisms: tumor necrosis factor-alpha (TNF-alpha) (-308), interleukin (IL)-10 (-1082, -819, and -592), TGF-beta1 (codon 10 and 25), IL-6 (-174), and interferon-gamma (INF-gamma) (+874). The distribution of polymorphisms in this population did not differ from published controls. The patients were classified as either non-rejecters (0 or 1 episode) or rejecters (> 1 episode) based on the number of biopsy proven rejection episodes in the first year after transplantation.

RESULTS

Forty-two of the 69 TNF-alpha patients (61%) in the low producer group were non-rejecters, while 9 of the 24 (37.5%) with high TNF-alpha were non-rejecters (p = 0.047). In contrast, IL-10 genotype showed the opposite finding. Forty-two of the 66 patients (64%) in the high and intermediate IL-10 group were non-rejecters, while 9 of the 26 (35%) in the low IL-10 group were non-rejecters (p = 0.011). The combination of low TNF-alpha with a high or intermediate IL-10 genotype was associated with the lowest risk of rejection (34/49 or 69% non-rejecters). Neither the distribution of the IL-6, INF-gamma, and TGF-beta1 genotype in recipients nor the donor genotype showed any association with acute rejection.

CONCLUSION

Genetic polymorphisms that have been associated with low TNF-alpha and high IL-10 production are associated with a lower number of acute rejection episodes after pediatric heart transplantation.

Therapeutic implications of inflammation in atherosclerotic cardiovascular disease

Atherosclerosis represents a spectrum of pathologic lesions with diverse clinical sequelae. In this review, we build upon the paradigm that arteriosclerosis represents an inflammatory disease. By examining mechanisms involved in the response to vascular injury, we can more effectively implement targeted therapy aimed at halting or regressing arteriosclerosis.

Evidence-based decision making in dental hygiene education, practice, and research

PURPOSE

The purpose of this article is to highlight key aspects of the white paper prepared in 1999 for the American Dental Hygienists' Association (ADHA) Institute for Oral Health on Evidence-Based Decision Making and its Application to Dental Hygiene Education, Practice, and Research. These aspects include the need for evidence-based decision making, how it supports contemporary practice and education, basic evidence-based concepts, and strategies for integrating evidence-based decision making into dental hygiene.

METHODS

A review of the biomedical literature, evidence-based Internet sites and textbooks, and clinical guideline development was systematically conducted to identify models of evidence-based practice, skills needed to practice and teach evidence-based decision making (EBDM), and challenges faced by those implementing an EBDM approach. These resources were then analyzed and synthesized to develop a model for initiating the development of evidence-based dental hygiene practice.

RESULTS

The need for using an evidence-based decision making approach was well supported throughout the literature. Consistency was found in how EBDM methodology and levels of evidence were defined and in the skills required for evidence-based practice. Implied in the use of an evidence-based approach were corresponding requirements in three areas: 1) redesigning educational programs to better prepare students and current practitioners to integrate the most current knowledge into their clinical decision-making; 2) conducting research for areas in which evidence applicable to clinical practice is lacking or limited; and 3) designing more effective dissemination tools making relevant research findings more easily accessible and part of every day practice.

CONCLUSIONS

Variations in practice patterns, difficulties in keeping current with the scientific literature, and providing students with knowledge, skills, and competencies necessary for contemporary practice are challenges facing the health care professions today, including dental hygiene. To address these problems, an evidence-based approach has been recommended by national organizations. This paper reviews the issues and proposes a model and strategies for engaging dental hygiene clinicians, educators, and researchers in EBDM. Those involved in each area will need training in EBDM concepts and skills before this approach can be fully integrated into education and practice or used to guide research activities. National leadership will be needed to coordinate and prioritize research strategies, promote curricular changes, and improve access to clinically relevant information so that an EBDM approach can become the norm in practice.

Field Control of Bacterial Spot and Bacterial Speck of Tomato Using a Plant Activator

Acibenzolar-S-methyl (CGA 245704 or Actigard 50WG) is a plant activator that induces systemic acquired resistance (SAR) in many different crops to a number of pathogens. Acibenzolar-S-methyl was evaluated for management of bacterial spot (Xanthomonas axonopodis pv. vesicatoria) and bacterial speck (Pseudomonas syringae pv. tomato) of tomato in 15 and 7 field experiments, respectively. Experiments were conducted over a 4-year period in Florida, Alabama, North Carolina, Ohio, and Ontario using local production systems. Applied at 35 g a.i. ha^-1, acibenzolar-S-methyl reduced foliar disease severity in 14 of the 15 bacterial spot and all 7 bacterial speck experiments. Disease control was similar or superior to that obtained using a standard copper bactericide program. Acibenzolar-S-methyl also reduced bacterial fruit spot and speck incidence. Tomato yield was not affected by using the plant activator in the field when complemented with fungicides to manage foliar fungal diseases, but tomato transplant dry weight was negatively impacted. X. axonopodis pv. vesicatoria population densities on greenhouse-grown tomato transplants were reduced by acibenzolar-S-methyl treatment. Bacterial speck and spot population densities on leaves of field-grown plants were not dramatically affected. Acibenzolar-S-methyl can be integrated as a viable alternative to copper-based bactericides for field management of bacterial spot and speck, particularly where copper-resistant populations predominate.

The case for beta-adrenergic blockade as prophylaxis against perioperative cardiovascular morbidity and mortality

Perioperative morbidity and mortality are frequently cardiac in origin. Many studies have prospectively attempted to define risk factors for cardiac ischemic events. Although we can now identify high-risk patients, optimal cardioprotective management strategies remain unclear. Treatment with beta-adrenergic antagonists decreases myocardial oxygen consumption and is generally well tolerated. This article reviews the physiologic and clinical basis for using these agents as prophylaxis against cardiovascular events in high-risk surgical patients.

Equal opportunities, equal risks? Overuse injuries in female military recruits

BACKGROUND

The rate of female personnel medically discharged from service in the British Army has been rising steadily since 1992 from around 3 per 1,000 per year to over 35 per 1,000 in 1996, although there has been only a minor increase in medical discharges for males over the same period. This paper examines the increasing rate of medical discharge in young female members of the British Army from an aetiological perspective and reviews the literature to identify risk factors that may be relevant.

METHODS

Data from published military medical statistical reports were reviewed and the clinical records of a 10 per cent sample of females medically discharged for relevant conditions were examined.

RESULTS

The majority of the excess medical discharges had occurred in females under the age of 22 and were due to musculoskeletal disorders and injuries caused by military training. Data from the clinical records showed that 75.5 per cent (37/49) of those medically discharged for these conditions were recruits. Stress fractures and other overuse syndromes accounted for 70.2 per cent of medical discharges among the recruits in the sample.

CONCLUSION

Females undertaking strenuous exercise alongside males are at increased risk of injury. Risk factors include smoking, short stature, restricted dietary intake and menstrual disturbance. Equal opportunities legislation has been interpreted to require identical training for males and females, but some segregation of training may be acceptable provided the outcome of training is no less favourable to either gender, and this may reduce the excess risk of injury to females.

Role of androgens in the growth of endometrial carcinoma: an in vivo animal model

OBJECTIVE

We sought to create an animal model for the development of endometrial cancer in women with androgen excess. We examined the effects of estradiol and androgen, both alone and as precursors to estrogen biosynthesis on human endometrial cancers transplanted into a nude mouse model.

STUDY DESIGN

We transplanted an estrogen-responsive, well-differentiated, established human endometrial carcinoma, EnCa-101, subcutaneously into athymic male nude mice. We established, first, that aromatase was expressed in this cell line, inducible by estrogen. We measured the growth of the tumor in the various groups weekly with Vernier calipers. We examined the effects of estradiol and androgens, both aromatizable and nonaromatizable, on tumor growth.

RESULTS

Estrogen-supplemented tumors showed the greatest rate of growth and were significantly greater than the growth rate in castrate mice. Androgen-supplemented tumors showed a growth rate similar to that of tumors without significant hormonal exposure (castrate mice). Dihydrotestosterone had no effect on tumor growth in comparison with an agonadal state.

CONCLUSIONS

Aromatizable and nonaromatizable androgens have little growth-promoting effect on a well-differentiated endometrial carcinoma. Estradiol is the most potent growth stimulus in our model.

Cyclosporine challenge test revisited: does it predict outcome after solitary pancreas transplantation?

BACKGROUND

The selection of patients for solitary pancreas transplantation (PTA) requires identification of individuals who will not develop acute renal dysfunction in response to immunosuppressants. A cyclosporine challenge test (CCT) was developed to predict post-PTA kidney dysfunction secondary to calcineurin inhibitor immunosuppressants. We now report on the long-term follow-up of patients who received a PTA after undergoing a CCT.

METHODS

Twelve potential PTA recipients were administered cyclosporine A (CsA) for 6 wk. Creatinine clearance (CrCl) was measured at 2, 4, and 6 wk. Those who did not fail the CCT received PTA. Baseline and post-transplant CrCl were retrospectively evaluated in the original cohort and in a group of matched patients who received PTA without a CCT.

RESULTS

Of the original 12 recipients evaluated with the CCT, 6 received PTA. CrCl was followed for a mean of 45.8 months. Of the 4 who remained alive, 2 went on to develop renal failure (CrCl < 30 mL/min) at 18 and 65 months post-transplant. The baseline CrCl was higher in PTA recipients who had not been selected to be studied with CCT than those that were (117 +/- 32 vs 78 +/- 13 mL/min). By 12 months post-PTA, the CrCl was no longer different between the groups selected to be screened with CCT and those that were not.

CONCLUSIONS

CCT may help predict risk for short-term changes in renal function (< 18 months) in response to CsA. CCT may be most helpful in candidates for PTA with borderline renal insufficiency (60-80 mL/min).

Posttransplant diabetes mellitus in pediatric thoracic organ recipients receiving tacrolimus-based immunosuppression

BACKGROUND

Posttransplantation diabetes mellitus (PTDM) is a well-known complication of tacrolimus-based immunosuppression in both adult and pediatric solid organ recipients. The "natural history" of diabetes in the pediatric thoracic transplant population has not yet been described.

METHODS

We identified all pediatric thoracic transplant patients receiving tacrolimus-based immunosuppression who developed PTDM. Medical records were reviewed, with a particular focus on the clinical course of PTDM and its relationship to drug weaning.

RESULTS

Diabetes developed in 24 of 143 (17%) 30-day survivors of heart (12/96, 13%) and heart-lung/lung (12/ 47, 26%) transplantation. In 17 (71%) patients, the immunosuppressive regimen at the onset of PTDM also included maintenance corticosteroids. Seventeen patients demonstrated glucose intolerance before the onset of diabetes. Nine patients (38%) developed diabetes during pulsed corticosteroid therapy. Median time of onset after transplantation was 9.0 months. All patients required s.c. insulin for glucose control. The median follow-up from transplant was 49.9 months. There was a significant decrease in mean tacrolimus dosage (P<0.01), tacrolimus level (P<0.04), and steroid dosage (P<0.02) from onset of PTDM to most recent follow-up. Despite this significant reduction in immunosuppression, only 3/24 (13%) patients were successfully weaned off insulin.

CONCLUSIONS

Diabetes mellitus is a common complication in pediatric thoracic transplant patients receiving tacrolimus-based immunosuppression. Insulin dependence in our population rarely resolved, even after lowering tacrolimus and steroid doses. Discontinuation of steroids did not guarantee resolution of diabetes.

Reproductive hormones after pancreas transplantation

BACKGROUND

Reproductive hormone function after pancreas transplantation (PTX) is unknown as it has not been studied.

METHODS

We prospectively studied PTX recipients to determine changes in reproductive hormones after PTX. Testosterone or estradiol, leutinizing hormone, follicle stimulating hormone, and prolactin were determined before and 1 year after PTX in 23 patients (10 women, 13 men) followed for more than 1 year after PTX. Of these, 11 received simultaneous kidney-PTX; 8 PTX only; and 4, PTX after kidney. Average age was 38.4+/-1.6 years and average duration of diabetes was 24.5+/-1.3 years. Nine (four women, five men) patients had been on dialysis pre-PTX. Sixteen of 23 patients were treated with cyclosporine and seven with FK-506 along with prednisone and azathioprine post-PTX.

RESULTS

Mean testosterone in men was normal pre- and post-PTX. Two men had secondary hypogonadism pre-PTX with resolution in one and persistence in the other post-PTX. Five of the ten women had evidence of hypogonadism pre-PTX: three had primary hypogonadism and two had secondary hypogonadism. Post-PTX, 7 of 10 women had abnormal reproductive hormones: 4 had primary hypogonadism, 2 had secondary hypogonadism, and 1 developed hyperestrogenemia with elevated estradiol (482 pg/ml) and leutinizing hormone (41 IU/liter). Mean prednisone dose and cyclosporine trough level were higher in the women than the men (P<0.05). No cases of secondary hypogonadism that developed or resolved post-PTX were related to changes in prolactin, renal function, or hyperglycemia.

CONCLUSIONS

Women are more likely than men to have reproductive hormone abnormalities pre- and post-PTX and the causes may be multiple.

Neural and behavioral teratological evaluation of rats exposed to ultra-wideband electromagnetic fields

Several investigators have reported teratologic effects of electromagnetic field exposure. The majority of these studies have been performed at levels of exposure that could produce substantial heating of the animals. New and unique sources of ultra-wideband (UWB) electromagnetic fields are currently being developed and tested that are capable of generating nonthermalizing, high-peak-power, microwave (MW) pulses with nanosecond (ns) pulse widths, picosecond (ps) rise times, and an UWB of frequencies. Our study was performed to determine if teratological changes occur in rat pups as a result of (i) daily UWB exposures during gestation days 3-18, or (ii) as a result of both prenatal and postnatal (10 days) exposures. Dams were exposed either to (i) UWB irradiation from a Kentech system that emitted a 55 kV/m-peak E field, 300 ps rise time, and a 1.8 ns pulse width, average whole-body specific absorption rate 45 mW/kg; (ii) sham irradiation; or (iii) a positive control, lead (Pb) acetate solution (2000 microg/ml) continuously available in the drinking water. Offspring were examined for ontogeny (litter size, sex-ratios, weights, coat appearance, tooth-eruption, eye-opening, air-righting, and ultrasonic stress vocalizations). Male pups were tested on various performance measures (locomotor, water-maze learning, and fertilization capabilities). The pups postnatally exposed were examined for hippocampal morphology and operant behavior. Behavioral, functional, and morphological effects of UWB exposure were unremarkable with these exceptions: (i) The UWB-exposed pups emitted significantly more stress vocalizations than the sham-exposed pups; (ii) the medial-to-lateral length of the hippocampus was significantly longer in the UWB-exposed pups than in the sham-exposed animals; (iii) male offspring exposed in utero to UWB mated significantly less frequently than sham-exposed males, but when they did mate there was no difference in fertilization and offspring numbers from the sham group. There does not appear to be a unifying physiological or behavioral relationship among the significant differences observed, and our findings could be due to the expected spurious results derived when a large number of statistical comparisons are made. Significant effects found between our positive-controls and other groups on numerous measures indicates that the techniques used were sensitive enough to detect teratological effects. Bioelectromagnetics 21:524-537, 2000. Published 2000 Wiley-Liss, Inc.

Unfit for further service: trends in medical discharge from the British Army 1861-1998

Military service requires individuals who are free from ill-health and who are physically and mentally robust, and throughout history those who have become unfit for service have been discharged on medical grounds. This paper uses published historical records to examine trends in the rate of discharge for six key conditions for the period 1861-1998 and to draw conclusions. In the late 19th and early 20th centuries, communicable diseases such as tuberculosis and syphilis were a major problem together with ill-defined conditions such as "disordered action of the heart". By the mid-20th century, psychiatric and gastrointestinal disorders had become the principal causes of medical discharge, whereas in the late 20th century, the majority of discharges resulted from injuries and musculoskeletal disorders. The pattern of conditions leading to medical discharge from the Army tends to mirror conditions which are prevalent at that time in the civilian population.

Selective mitochondrial KATP channel opening controls human myocardial preconditioning: too much of a good thing?

BACKGROUND

Paradoxically, patients with noninsulin-dependent diabetes mellitus experience a higher cardiovascular mortality rate than patients with insulin-dependent diabetes mellitus. We have shown that K(ATP) channel inhibition, with oral sulfonylureas, prevents myocardial preconditioning and may explain the paradox of cardiovascular death in patients with noninsulin-dependent diabetes mellitus. Cardiac preconditioning is an attractive protective strategy against any elective ischemia/reperfusion (I/R) injury. The relationship between the K(ATP) channels and human myocardial preconditioning has not previously been elucidated.

METHODS

Human atrial trabeculae were harvested, placed in organ baths, and paced (1 Hz). Developed force was recorded during simulated 37 degrees C I/R (30/45 or 45/60 minutes). Before I/R, trabeculae were treated transiently with a selective mitochondrial K(ATP) channel opener for 5 minutes, followed by a 10-minute washout, or were exposed to the channel opener throughout ischemia. Recovery of function is expressed as percentage of baseline developed force. Conserved creatine kinase activity (units per gram of wet tissue) was measured at the end of reperfusion as an indicator of cellular protection.

RESULTS

Transient mitochondrial K(ATP) channel opening provided protection from both I/R insults. Surprisingly, there was no protection afforded by continuous mitochondrial K(ATP) channel opening.

CONCLUSIONS

Transient selective mitochondrial K(ATP) channel opening protects both viability and function of human myocardium against I/R injury, although prolonged opening of the mitochondrial K(ATP) channel does not. These results reinforce the concept of preconditioning as a transient event that must be completed before the onset of ischemia.

Endomyocardial biopsy in pediatric heart transplant recipients: a useful exercise? (Analysis of 1,169 biopsies)

The objective of this study was to define the diagnostic yield for endomyocardial biopsy (EMB) procedures performed for various indications in a large pediatric heart transplant population. Endomyocardial biopsy procedure has been employed as the 'gold standard' for rejection surveillance. Previous studies have questioned the value of surveillance EMB beyond the early post-transplant period. We retrospectively reviewed data on 82 pediatric heart transplant recipients with serial EMB. A total of 1,169 EMB were performed during a follow-up period of 2-149 months (median 41 months). EMB were classified by age at transplantation, time from transplant, immunosuppressive regimen used [tacrolimus vs. cyclosporin A (CsA)] and indication, i.e. surveillance, follow-up after rejection or lowering of immunosuppression, non-specific clinical symptoms and graft dysfunction. During the first year after heart transplantation, surveillance EMB demonstrated significant rejection [International Society for Heart and Lung Transplantation (ISHLT) grade > or = 3A] in 18% of biopsies with the yield being 14-43% for all other indications. Surveillance EMB 1-5 yr post-transplantation were found to have a lower diagnostic yield in infants (4%, vs. 13% in children) and in patients with favorable first-year rejection history (9% vs. 17% in 'frequent rejectors'). Tacrolimus-based immunosuppression was associated with significantly less rejection, but only in the first year post-transplantation (14% in tacrolimus vs. 24% in CsA surveillance EMB, p = 0.035). Surveillance EMB remains an important diagnostic tool for rejection surveillance during the first 5 years after pediatric heart transplantation. Endomyocardial biopsy is particularly warranted after reduction of immunosuppression and for monitoring for ongoing rejection after treatment of acute rejection episodes.

First Report of Bacterial Canker of Pepper in Ohio

Light brown, raised lesions were observed on the leaves of bell pepper (Capsicum annuum L.) plants throughout a commercial field in northwest Ohio in 1999. Bacterial streaming from the lesions was observed microscopically. Five representative, pale yellow colonies isolated on yeast dextrose carbonate medium were selected and purified. All isolates induced a hypersensitive response in Mirabilis jalapa L. plants 24 h after inoculation with a 1 × 10⁸ CFU/ml bacterial suspension. All five were identified as Clavibacter michiganensis subsp. michiganensis by fatty acid methyl ester analysis (mean similarity index [S.I.] = 0.76; MIDI, Newark, DE). Identity was confirmed at the University of Hawaii (W. Kaneshiro and A. Alvarez) by carbon substrate utilization pattern (mean S.I. = 0.75; Biolog, Hayward, CA) and positive reactions with C. michiganensis subsp. michiganensis-specific monoclonal antibodies (clones 103-142-1-1 and 103-148-2-1) in ELISA. DNA extracted from lesions and pure cultures was used as template in a polymerase chain reaction (PCR) assay with primers specific for C. michiganensis subsp. michiganensis (CMM-5 and CMM-6) (1). DNA from a known strain of C. michiganensis subsp. michiganensis served as a positive control, while water and DNA from healthy tomato plants were used as negative controls. A 0.6-kb PCR product was amplified from lesions, pure cultures of all five strains, and positive control DNA, but not from the negative controls. Pathogenicity tests were performed twice on 5- to 6-week-old bell pepper (cvs. Collossal, Lafayette, King Arthur, Brigadier, and Commandant) and tomato (cv. Peto 696) plants. Pepper plants were inoculated with each strain by clipping the lowest petioles with scissors that had been dipped into a bacterial suspension (1 × 10⁸ CFU/ml) or by spray inoculation (approximately 5 ml/plant). Tomato plants were inoculated by clipping. Both inoculation methods included a water control. All five strains caused water-soaked lesions on leaves of all pepper varieties within 7 days after spray inoculation. Pepper plants inoculated by clipping did not develop symptoms. DNA extracts from lesions of challenged pepper plants were positive in PCR. All inoculated tomato seedlings exhibited wilting, streaks, and cankers in the stems and necrosis of leaf margins within 15 days after inoculation. None of the control plants developed symptoms. All five strains were re-isolated from inoculated tomato and pepper plants. The original pepper strains and the strains re-isolated from tomatoes were compared using rep-PCR with ERIC primers (4). DNA fingerprints of the re-isolated strains were identical to those of the original strains and were characteristic of C. michiganensis subsp. michiganensis type C. Bacterial canker is a common disease of tomatoes worldwide and has occurred in Ohio for at least 70 years. However, this is the first report of C. michiganensis subsp. michiganensis infecting peppers in Ohio. While the pathogen does not appear to cause systemic disease in peppers, it may serve as a source of inoculum for tomatoes, which are highly susceptible to the disease and often produced in the same greenhouse as peppers or planted in adjacent fields. Bacterial canker has been reported previously from commercial pepper fields in California (2) and Indiana (3). References: (1) J. Dreier et al. Phytopathology 85:462, 1995. (2) M. Lai. Plant Dis. Rep. 60:339, 1976. (3) R. Latin et al. Plant Dis. 79:860, 1995. (4) F. J. Louws et al. Appl. Environ. Microbiol. 60:2286, 1994.

Chemokines as mediators of diseases related to surgical conditions

Chemokines are important mediators of inflammation. Animal studies suggest that inhibition of chemokine action results in a decrease in inflammation. Novel anti-inflammatory agents directed against chemokines are now available. Surgeons are uniquely positioned to treat multiple chemokine-mediated diseases. In this article, we review the biology and nomenclature of chemokines as well as their role in neutrophil migration. Further, the potential role of chemokines in various diseases related to surgical conditions, including adult respiratory distress syndrome, atherosclerosis, inflammatory bowel disease, and solid organ rejection, is reviewed. Finally, the idea that chemokines could be targets for novel therapeutic agents is discussed.

Ultrawideband radiation and pentylenetetrazol-induced convulsions in rats

New non-ionizing pulsed systems using ultrawideband (UWB) require safety assessment before they can be used by either military or civilian communities. The development of directed energy weaponry intended for use against electronically vulnerable targets, as well as ground-probing radar systems, have used fast-rise-time high-peak-power electromagnetic pulses characteristic of UWB emitters. It has been postulated that these ultrashort pulses might produce electromagnetic transients resulting in tissue damage. Several challenges to this notion have been posed, however. One report found that rats exposed to UWB after receiving a convulsant drug tended toward longer latency to the onset of convulsions than the no-exposure group. Although not statistically significant, the presence of this trend prompted the present study. An ED99 dose of the convulsant pentylenetetrazol (PTZ) or saline was given just before UWB or sham exposure and resultant seizure activity was recorded. The data from the current study show no effect of UWB exposure on PTZ-induced seizure activity, thereby not supporting the tissue damage concerns, at least for the exposure parameters used here.

Chlamydia pneumoniae activates nuclear factor kappaB and activator protein 1 in human vascular smooth muscle and induces cellular proliferation

BACKGROUND

Observational data strongly suggest an association between Chlamydia pneumoniae and atherosclerotic cardiovascular disease. However, few studies have mechanistically linked C. pneumoniae to vascular remodeling. The purpose of the present study was to examine the mechanistic relationship between C. pneumoniae and human vascular smooth muscle cell (VSMC) physiology. We sought to determine the influence of human VSMC infection by C. pneumoniae on (1) VSMC proliferation and (2) activation of the proinflammatory and proliferative transcription factors nuclear factor kappaB (NF-kappaB) and activator protein 1 (AP-1).

MATERIALS AND METHODS

C. pneumoniae was grown and isolated from Hep 2 cells. Human aortic VSMCs were inoculated with C. pneumoniae in the presence and absence of the azalide antibiotic azithromycin. Cell proliferation was assayed by direct cell counting 48 h following infection. Two hours following infection, nuclear extracts were isolated, and activation of both NF-kappaB and AP-1 was assessed by electrophoretic mobility shift assay.

RESULTS

Compared with control, C. pneumoniae infection stimulated VSMC proliferation (P < 0.05) and induced both NF-kappaB and AP-1 DNA binding activity. These effects were eliminated by concurrent treatment with azithromycin.

CONCLUSIONS

VSMC infection with C. pneumoniae activates proliferative intracellular signals and stimulates cell growth. These data implicate C. pneumoniae as a pathogenic mediator and a potential therapeutic target in the prevention of atherosclerotic disease.

HER-2/neu blocks tumor necrosis factor-induced apoptosis via the Akt/NF-kappaB pathway

Overexpression of HER-2/neu correlates with poor survival of breast and ovarian cancer patients and induces resistance to tumor necrosis factor (TNF), which causes cancer cells to escape from host immune defenses. The mechanism of HER-2/neu-induced TNF resistance is unknown. Here we report that HER-2/neu activates Akt and NF-kappaB without extracellular stimulation. Blocking of the Akt pathway by a dominant-negative Akt sensitizes the HER-2/neu-overexpressing cells to TNF-induced apoptosis and inhibits IkappaB kinases, IkappaB phosphorylation, and NF-kappaB activation. Our results suggested that HER-2/neu constitutively activates the Akt/NF-kappaB anti-apoptotic cascade to confer resistance to TNF on cancer cells and reduce host defenses against neoplasia.

Retrobulbar pseudotumor of the orbit in a cat

Idiopathic nonspecific inflammatory disease of the orbit (orbital pseudotumor) was diagnosed detected in a cat. The cat had progressive lagophthalmia, keratitis, and decreased motion of the right eye. Four months later, the left eye was affected in a similar manner. Response to antibiotics and immunosuppressive agents was not detected. Computed tomography of the brain and orbits revealed bilateral thickening of the sclera and episcleral tissues. Bilateral exenteration of the eyes was required because of worsening clinical signs or corneal perforation. Histologic examination revealed proliferation of spindle cells and fibrovascular tissue within and adjacent to the sclera.

Costs and savings of investigational drug services

The costs and savings resulting from two pharmacy-based investigational drug services (IDSs) for fiscal year 1996-97 were studied. The costs and savings associated with IDSs at two joint institutions were calculated by adding the cost-avoidance figures (money that would most likely have been spent, but was not because of a specific intervention or program) to the money received from services charged to study investigators or patients and subtracting salaries and overhead costs. Only drugs for which the authors could obtain prices were used to calculate cost-avoidance figures. The number of doses of marketed drugs that were provided free or for which the pharmacy was reimbursed by a drug study sponsor between July 1996 and June 1997 was tabulated from pharmacy dispensing records for each study. Investigational drugs that were not marketed or for which no marketed alternative was available were not included in the cost-avoidance calculation but were included in the charges for IDSs. The total cost of IDSs at the two institutions was $249,112. Income (representing cost avoidance and payments received) totaled $2,958,774, giving the IDSs an overall saving of $2,709,662. The two disease categories with the largest cost-avoidance figures were AIDS and oncology. In total, there was a cost avoidance of $2.9 million in drug costs, which is equivalent to 8% of the institutions' annual drug budget for 1996-97. IDSs in two institutions accounted for a combined one-year saving of over $2.7 million, most of which was attributable to cost avoidance from not having to purchase study drugs.

Precise detection and tracing of Trichoderma hamatum 382 in compost-amended potting mixes by using molecular markers

Randomly amplified polymorphic DNA (RAPD) analysis and the PCR assay were used in combination with dilution plating on a semiselective medium to detect and enumerate propagules of Trichoderma hamatum 382, a biocontrol agent utilized in compost-amended mixes. Distinct and reproducible fingerprints were obtained upon amplification of purified genomic DNA of T. hamatum 382 with the random primers OPE-16, OPH-19, and OPH-20. Three amplified DNA fragments of 0.35 (OPE-16(0.35)), 0.6 (OPH-19(0.6)), and 0.65 (OPH-20(0.65)) kb were diagnostic for T. hamatum 382, clearly distinguishing it from 53 isolates of four other Trichoderma spp. tested. Some isolates of T. hamatum shared these low-molecular-weight fragments with T. hamatum 382. However, RAPD analysis of isolates of T. hamatum with all three random primers used in consecutive PCR tests distinguished T. hamatum 382 from other isolates of T. hamatum. These three RAPD amplicons were cloned and sequenced, and pairs of oligonucleotide primers for each cloned fragment were designed. Use of the primers in the PCR assay resulted in the amplification of DNA fragments of the same size as the cloned RAPD fragments from genomic DNA of T. hamatum 382. A combination of dilution plating on a semiselective medium for Trichoderma spp. and PCR, with the RAPD primers OPH-19, OPE-16, and OPH-20 or the three sequence-characterized primers, was used successfully to verify the presence of T. hamatum 382 propagules in nine different soil, compost, and potting mix samples. All 23 Trichoderma isolates recovered on semiselective medium from commercial potting mixes fortified with T. hamatum 382 were identified as T. hamatum 382, whereas 274 Trichoderma isolates recovered from the other nine samples were negative in the PCR assay. Thus, this highly specific combination of techniques allowed detection and enumeration of propagules of T. hamatum 382 in fortified compost-amended potting mixes. Sequence-characterized amplified region markers also facilitated the development of a very simple procedure to amplify DNA of T. hamatum 382 directly from fortified compost-amended potting mixes.

Domains of differential cell proliferation suggest hinged folding in avian gut endoderm

A profile of proliferative growth assessed with tritium autoradiograms from White Leghorn embryo stages Hamburger-Hamilton 6-21 labeled in ovo presents evidence of hinged folding driven by localized differential cell proliferation in endoderm. There is a significant, bilateral pattern, and differences are most pronounced in axial levels that are folding and rotating. Highest proliferation is in cells producing folds; lowest proliferation is in median cells. Localized changes in cell shape are lacking, as are TUNEL markers and cell morphology that would suggest involvement of apoptosis. Folding endoderm to form gut tube appears to be a process that is driven by domains of high cell proliferation flanking a domain of significantly lower proliferation. When considered in the context of an epithelium attached to subjacent mesoderm, these differentials could produce a forced and directed buckling of endoderm into lateral folds that join and enclose a tube. Patterns suggest that endoderm folds about a median hinge. In the light of this new information, we suggest it is more precise to refine the term, median hinge point (MHP), to neural hinge point (NHP) and gut hinge point (GHP).

Heterogeneous Catalysis with Cross-Linked Lyotropic Liquid Crystal Assemblies: Organic Analogues to Zeolites and Mesoporous Sieves

Organic, nanoporous heterogeneous catalysts based on a carboxylate-containing, amphiphilic mesogen catalyze the Knoevenagel condensation (see schematic representation). These networks maintain their order in solution and can be recycled. Enhanced basicity, excellent site accessibility, and substrate size exclusion are features of these nanostructured systems.

Optimal dosing of intravenous tacrolimus following pediatric heart transplantation

BACKGROUND

Early experience with intravenous tacrolimus at high doses (0.1-0.15 mg/kg/day) was associated with frequent clinical toxicity. The optimal dosing regimen after pediatric heart transplantation is unknown.

METHODS

We retrospectively reviewed data on the last 45 pediatric heart transplant recipients to document the time required to achieve therapeutic blood levels and the safety of 2 differing intravenous dosing regimens (tacrolimus 0.03 & 0.05 mg/kg/day as continuous i.v. infusion). Target plasma levels were (1.2-1.7 ng/ml) with levels >2.0 ng/ ml considered toxic, and target whole blood levels were 15-20 ng/ml with levels >25 ng/ml considered toxic.

RESULTS

Mean age at transplantation was 7.5 +/- 5.6 years (0.1-18), and 14 were infants. Intravenous tacrolimus was commenced at a mean of 7 +/- 3 hours (range 2-16) after arrival in the ICU. Eight patients were excluded from analysis because of protocol modifications. Of the remaining 37 pts, 9 received initial infusion at 0.03 mg/kg/day; 3 (33%) achieved 'therapeutic' levels within 48 hours and 1 patient had a toxic level (27 ng/ml) at 36 hours. Twenty-eight patients received 0.05 mg/kg/day; 18 (64%) achieved therapeutic levels within 48 hours and 9 (32%) developed toxic levels. Patients with toxic whole blood levels had higher tacrolimus levels on first blood assay compared to those who did not develop toxicity (16.4 +/- 3.4 vs 9.3 +/- 3.9, p < .0001; level >10 ng/ml on first assay in 7/7 toxic patients vs 7/19 without toxicity, p = .004). Patients receiving the higher dose regimen had fewer episodes of moderate or severe rejection (> or =Grade 3A) at first biopsy than those receiving the lower dose infusion (32% vs 75%; p = .046). No patient required renal dialysis.

CONCLUSIONS

Dosing below 0.05 mg/kg/day may result in clinically important delay in achieving therapeutic levels. Toxicity may be reduced by frequent monitoring of levels for the first 48 hours after transplantation especially when the initial level is >10 ng/ml.

First Observation of Xanthomonas campestris pv. vesicatoria Race T2P7 Isolated from Pepper in the Philippines

Thirteen strains of Xanthomonas campestris pv. vesicatoria, causal agent of bacterial spot of pepper (Capsicum spp.) and tomato (Lycopersicum spp.), were isolated from six different pepper fields in the vicinity of Bongabon, Luzon, the Philippines. The strains were characterized based on sensitivity to copper and streptomycin, physiological tests, analysis of whole cell fatty acids (fatty acid methyl ester; FAME), serology, amplification of the 16S-23S rDNA spacer region, pathogenicity, and virulence on pepper and tomato differential genotypes as previously described (1,2). All of the Philippine strains were copper resistant (50 μg/ml), and streptomycin sensitive (20 μg /ml). None of the strains were pectolytic or amylolytic. FAME analysis showed that all strains had similar fatty acid profiles, and matched the strains to X. campestris (similarity indices [S.I.] = 0.186-0.455). With the universal primers 4F/7R, a DNA fragment (680 bp) was amplified from 16S-23S rDNA spacer regions of all Philippine strains. Serological fingerprints of the strains with a set of eight monoclonal antibodies (MAbs) in indirect enzyme-linked immunosorbent assay showed that all Philippine strains were serovar A1. Existence of the avrRxv gene in X. campestris pv. vesicatoria race T1 strains was also confirmed for all Philippine strains by amplifying a DNA fragment (approximately 0.7 kb) with the primer set RST 27/28. This is genetic evidence for race identity of the Philippine strains with T1. However, hypersensitive test results on pepper and tomato differential lines identified the Philippine strains as T2P7. These results showed that X. campestris pv. vesicatoria strains may contain the avrRxv gene, but it may not be functional. This is the first report of the observation of X. campestris pv. vesicatoria race T2P7 on pepper. References: (1) H. Bouzar et al. Phytopathology 84:664, 1994; (2) F. Sahin and S. A. Miller. Plant Dis. 82:794, 1998.

Liposomal delivery of purified inhibitory-kappaBalpha inhibits tumor necrosis factor-alpha-induced human vascular smooth muscle proliferation

Vessel injury results in the elaboration of various cytokines, including tumor necrosis factor-alpha (TNF-alpha), which may influence vascular smooth muscle cell (VSMC) function and contribute to atherogenesis. We tested the hypothesis that TNF-alpha-induced VSMC proliferation requires activation of the transcription factor nuclear factor-kappaB (NF-kappaB), which could be prevented by delivery of the NF-kappaB inhibitory peptide, IkappaBalpha. TNF-alpha induced concentration-dependent human VSMC proliferation, and neutralizing antibody to interleukin-6 reduced TNF-alpha-induced VSMC proliferation by 65%. In TNF-alpha-stimulated VSMCs, there was a 3-fold increase in NF-kappaB-dependent luciferase reporter activity that was associated with degradation of IkappaBalpha. To determine an essential role for NF-kappaB in TNF-alpha-induced VSMC proliferation, recombinant IkappaBalpha was introduced into VSMCs via liposomal delivery. Under these conditions, TNF-alpha-induced NF-kappaB nuclear translocation and DNA binding were inhibited, NF-kappaB-dependent luciferase activity was reduced by 50%, there was no degradation of native IkappaBalpha detected, interleukin-6 production was reduced by 54%, and VSMC proliferation was decreased by 60%. In conclusion, the mitogenic effect of TNF-alpha on human arterial VSMCs is dependent on NF-kappaB activation and may be prevented by exogenously delivered IkappaBalpha. Furthermore, liposomal delivery of endogenous inhibitory proteins may represent a novel, therapeutically accessible method for selective transcriptional suppression in the response to vascular injury.

Epidemiology of malaria in the British Army from 1982-1996

An epidemiological review was carried out of all known cases of malaria involving British soldiers between 1982-1996. Hospital records of 213 confirmed cases of malaria were obtained from the Defence Analytical Services Agency (DASA). More than half of the infections (52%) occurred as a result of military training in Kenya and 74% of these were due to Plasmodium falciparum which is potentially life-threatening. Mefloquine has been used as chemoprophylaxis by the British Army in Kenya since 1993 and the implications of this are discussed. There were no deaths in the series but malaria nevertheless remains a serious threat to the health of the British Soldier. The importance of adherence to chemoprophylaxis and of simple bite avoidance measures must continue to be emphasised.

Therapeutic implications of interleukin-10 in surgical disease

Pharmacological therapy of surgical disease often involves manipulating the physiologic balance between pro- and anti-inflammatory responses. Many agents target only one aspect of the inflammatory cascade. Originally identified as a protein elaborated by T-lymphocytes, IL-10 appears to globally inhibit cytokine production. The purpose of this manuscript is to examine the immunomodulatory and anti-inflammatory effects of interleukin-10 (IL-10) in an attempt to define the clinical utility of IL-10, both as a marker of and as a therapeutic strategy for intervention in inflammatory and immune-mediated diseases. IL-10 is elaborated from multiple sources and has diverse cellular effects to regulate immune and inflammatory responses. Accumulating evidence suggests that the anti-inflammatory influence of IL-10 observed at the cellular level may be manipulated to impact the immune and inflammatory-mediated responses associated with injury and sepsis, gastrointestinal and cardiovascular disease, and transplantation. In conclusion, IL-10 is an important mediator of immune and anti-inflammatory responses in surgical disease and, as such, has therapeutic promise as an immunomodulator and as an anti-inflammatory agent.

Clinical relevance of in vitro propagation of activated lymphocytes from endomyocardial biopsy samples of pediatric heart transplant recipients

In vivo activated T-lymphocytes can be cultured from endomyocardial biopsy samples of human cardiac allografts, sometimes even in the absence of histological rejection. We investigated the clinical relevance of this "lymphocyte growth assay" in pediatric heart transplant recipients. Specifically, we wished to determine if: (i) positive lymphocyte growth from EMB samples in the absence of significant rejection identifies a patient as being at increased risk for the development of acute rejection; (ii) withdrawal or major dose reduction of corticosteroids in the presence of lymphocyte growth results in high risk of rebound rejection; and (iii) presence of lymphocyte growth during acute rejection helps predict the response to treatment. Cultures were performed on 789 consecutive EMB samples from 65 pediatric heart transplant recipients in media containing 30 U/ml of recombinant IL-2. T-lymphocytes were cultured from 16% of EMB samples with low grade rejection (grade 0-1b) and from 34% of EMB samples with grade 2-4 rejection. EMB samples obtained early post-transplant (<180 days) were significantly more likely to yield positive lymphocyte growth compared to biopsies obtained late for any given rejection grade. Lymphocyte growth was comparable between patients managed with cyclosporine or tacrolimus based immunosuppression. For 227 EMB samples without rejection, a subsequent EMB sample was obtained within 12 weeks. Lymphocyte cultures were positive in 47 of these 227 EMB samples (21%), and in 19 out of 47 (40%) cases acute rejection (grade 2-4) was present on the follow-up EMB sample. By contrast, of 180 biopsies without growth, only 29 (16%) showed rejection at the next EMB (p<0.0001). When a follow-up biopsy was performed within 12 weeks of corticosteroid withdrawal, "rebound rejection" was observed in 3 out of 10 (30%) cases where the previous EMB sample yielded positive lymphocyte growth and in 4 out of 38 (11%) cases when it did not (p=0.29). The presence of lymphocyte growth in association with rejection was also predictive of whether rejection would resolve following high dose intravenous corticosteroid therapy (persistent rejection in 33 out of 50 (66%) cases with positive growth, versus 25 out of 80 (31%) cases without growth (p<0.0001)). Thus, positive lymphocyte growth is strongly associated with higher grade of rejection and earlier time from transplantation. Lymphocyte growth in the absence of rejection indicates high risk for rejection within the next 12 weeks. Growth in association with acute rejection indicates high probability of persistence of rejection following treatment with high dose corticosteroids.

Resistance in Capsicum pubescens to Xanthomonas campestris pv. vesicatoria Pepper Race 6

One hundred seventy Capsicum spp. germplasm accessions were evaluated as potential sources of resistance to X. campestris pv. vesicatoria pepper race 6 (P6). This race has been identified recently in Ohio and overcomes all three known resistance genes in cultivated pepper. Only C. pubescens plant introduction (PI) 235047 was found to be resistant to X. campestris pv. vesicatoria P6 strains using hypersensitivity and pathogenicity tests. Further studies using PI 235047 as a differential line showed that strains classified as X. campestris pv. vesicatoria races P1 and P3 were heterogeneous in terms of virulence. Strains of X. campestris pv. vesicatoria P1 and P3 that were compatible with PI 235047 were reclassified as two new pepper races, designated X. campestris pv. vesicatoria P7 and P8, respectively. According to the new race classification, PI 235047 plants are incompatible with X. campestris pv. vesicatoria pepper races P0, P1, P3, P4, and P6, but compatible with races P2, P5, P7, and P8.

An analysis of UVA emissions from sunlamps and the potential importance for melanoma

Exposure to solar UV radiation is a risk factor for cutaneous malignant melanoma (CMM). Epidemiologic studies have also considered the use of sunlamps as a possible contributor to CMM. We measured and analyzed the emission spectra of six different currently marketed sunlamps and a historical sunlamp, the UVB-emitting FS lamp, and compared the results to solar exposure. For a typical tanner (20 sessions @ 2 minimal erythema doses (MED)/session), the annual UVA doses from commonly used fluorescent sunlamps were 0.3-1.2 times that received from the sun. For a frequent tanner (100 sessions @ 4 MED/session), the annual UVA doses from fluorescent sunlamps were 1.2-4.7 times that received from the sun and 12 times for recently available, high-pressure sunlamps. To determine biologically effective doses, action spectra for squamous cell carcinoma (SCC) in humans and for melanoma in the Xiphophorus fish (XFM) were applied to the sunlamps' emission spectra. The results for the effective doses using the SCC action spectrum tracked the UVB doses, while the results using the XFM action spectrum tracked the UVA doses. When combined with UV exposure received from the sun, typical sunlamp use results in an approximate doubling of annual effective dose, if the XFM action spectrum is applied. Frequent use, however, can increase the annual effective XFM dose by as much as 6 times what would be received from the sun alone for fluorescent sunlamps and as much as 12 times for newer, high-pressure sunlamps.

Apoptosis in cavitation of middle ear space

Mesenchyme cells surround early ossicles in the developing middle ear, then are replaced by space that is created by what has been described as an expansion of the pharyngeal pouch. Cell death has not been considered important in cavitation of chick middle ear (Jaskoll and Maderson [1978] Anat. Rec., 190:177-200), but an uncharacterized form of cell death has been reported to play a major role in cavitation of mouse middle ear (Jaskoll [1977] PhD thesis, CUNY). We investigated whether this uncharacterized cell death is the non-random form known as apoptosis. We examined the middle ear cavitation process using an in situ immunomarker for apoptosis. CBy RF mice during prenatal days 15-20 and postnatal days 1-3 and chick embryos representing HH stages 33-38 were investigated. Apoptotic cells were marked in mouse postnatal day 1. No indication of apoptosis was present in other prenatal and postnatal days of development included in this study, although morphology showed that cavitation proceeds over several perinatal days in the mouse. Apoptosis was not marked in the chick middle ear. Previously observed cell death in murine middle ear is the non-random form of cell death known as apoptosis. Cell death has not been reported in avian middle ear, and lack of apoptotic marker supports those observations. The limited occurrence of apoptosis in mice and apparent absence of apoptosis in chicks suggest that several mechanisms contribute to cavitation of vertebrate middle ear space.

Two New Hosts of Xanthomonas campestris pv. vitians

Bacterial leaf spot of lettuce (Lactuca sativa L.) caused by Xanthomonas campestris pv. vitians (proposed new names X. axonopodis pv. vitians / X. hortorum pv. vitians) is an economically important disease in many areas of the world (1,2). Serious outbreaks occurred in Ohio in 1995 and 1996. The primary sources of the causal agent are presumed to be contaminated seed and infected plant debris in the field. Once the disease is present in a field, crop rotation is required to decrease primary inoculum of the pathogen. Therefore, appropriate crop rotation sequences need to be determined based on the host range of the pathogen. Some vegetable crops, including tomato, pepper, cabbage, collard, kale, radish, and horseradish, were tested for susceptibility to four representative strains of X. campestris pv. vitians by spray inoculation in the greenhouse. Typical symptoms of bacterial leaf spot were observed on tomato and pepper plants 8 days after inoculation, whereas the other crops did not develop diagnostic symptoms. The pathogen was reisolated and Koch's postulates were completed on tomato and pepper. This is the first report that X. campestris pv. vitians strains can cause bacterial spot disease on tomato and pepper. References: (1) C. L. Patterson et al. Plant Dis. 70:982, 1986. (2) L. Vauterin et al. Int. J. Syst. Bacteriol. 45:472, 1995.

Right-left asymmetry of cell proliferation predominates in mouse embryos undergoing clockwise axial rotation

BACKGROUND

Differential growth is fundamental to most mechanisms proposed for axial rotation in amniotes. Other mechanisms such as changes in cell shape are not consistently suggested by ultrastructure. Lateral asymmetries in cell proliferation exist in mouse and chick embryos undergoing normal, anticlockwise axial rotation, but there has been no investigation of inverse clockwise rotation that could test the correlation.

METHODS

We used the BALB/cHu-iv/iv, situs inversus mouse to test the apparent correlation of lateral asymmetries with morphogenesis that we saw in cell division patterns of normally rotating mice. Proliferation indices were collected from tritium autoradiograms.

RESULTS

Asymmetry of cell proliferation in inverse axial rotation is a mirror image of the pattern seen for normal axial rotation: right predominates over left. This asymmetry is statistically significant and correlates with morphology. Patterns of proliferation in constraining extraembryonic membranes, particularly visceral yolk sac, suggest that rotation could be pushed by uneven lateral growth as body and gut tubes form, for they are attached to these membranes.

CONCLUSIONS

Data from iv/iv mice provide additional evidence that differential growth, constrained by contiguous extraembryonic membranes, may drive closure of body and gut walls and contribute to axial rotation. Asymmetries of cell proliferation are likely consequences of genetic cascades, and will need to be incorporated with in situ information on gene activity.