Effect of the width of the herbicide strip on mite dynamics in apple orchards.

Herbicide strips are used in apple orchards to promote tree growth and survival, to increase yield and to reduce the risk of rodent damage to tree bark. However, herbicide strips, particularly wider ones, may cause problems including soil erosion, reduced organic matter, leaching of nitrates into ground water and increased incidence of plant diseases and pests, including two-spotted spider mites, Tetranychus urticae Koch. In this 2 year study we monitored mite dynamics in apple trees and used sticky bands on tree trunks to determine rates of T. urticae immigration into Nova Spy apple trees in plots with wide (2 m) or narrow (0.5 m) herbicide strips. Use of wider herbicide strips promoted two risk factors that could trigger outbreaks of tetranychid mites. First, concentrations of leaf N in apple trees were higher and those of P and K were lower with the wide strips. Such changes in nutritional quality of leaves would increase the potential for more rapid population growth of T. urticae, and to a lesser extent, the European red mite, Panonychus ulmi (Koch). Second, there were higher rates of T. urticae immigration from the ground cover vegetation into the trees. In 2006, and for most of 2007, densities of T. urticae were higher with wide herbicide strips, whereas densities of P. ulmi were not enhanced. However, by late August to early September in 2007, densities of both tetranychids were lower with wide herbicide strips. This is because both risk factors were counterbalanced, and eventually negated, by the enhanced action of phytoseiid predators, mostly Typhlodromus pyri Scheuten. From July through September 2006, ratios of phytoseiids to tetranychids were always several-fold lower with wide herbicide strips but in 2007, from mid-July onwards, predator-prey ratios were usually several-fold higher with wide strips. However, this numerical response of phytoseiids to prey density can only occur where the pesticide program in orchards is not too harsh on phytoseiids. Hence the impact of width of herbicide strip is contingent on the composition and size of the phytoseiid complex and the impact of pesticides on predation.

Effects of acaricides, pyrethroids and predator distributions on populations of Tetranychus urticae in apple orchards.

We sampled mites in three apple orchards in Nova Scotia, Canada, that had been inoculated with pyrethroid-resistant Typhlodromus pyri and had a history of Tetranychus urticae outbreaks. The objective of this study was to monitor populations of T. urticae and phytoseiid predators on the ground and in trees and to track dispersal between the two habitats. Pesticides were the chief cause of differences in mite dynamics between orchards. In two orchards, application of favourably selective acaricides (abamectin, clofentezine) in 2002, coupled with predation by T. pyri in trees and Neoseiulus fallacis in ground cover, decreased high T. urticae counts and suppressed Panonychus ulmi. By 2003 phytoseiids kept the tetranychids at low levels. In a third orchard, application of pyrethroids (cypermethrin, lambda-cyhalothrin), plus an unfavourably selective acaricide (pyridaben) in 2003, suppressed phytoseiids, allowing exponential increases of T. urticae in the ground cover and in tree canopies. By 2004 however, increasing numbers of T. pyri and application of clofentezine strongly reduced densities of T. urticae in tree canopies despite high numbers crawling up from the ground cover. Another influence on T. urticae dynamics was the distribution of the phytoseiids, T. pyri and N. fallacis. When harsh pesticides were avoided, T. pyri were numerous in tree canopies. Conversely, only a few N. fallacis were found there, even when they were present in the ground cover and on tree trunks. Low numbers were sometimes due to pyrethroid applications or to scarcity of prey. Another factor was likely the abundance of T. pyri, which not only competes with N. fallacis, but also feeds on its larvae and nymphs. The scarcity of a specialist predator of spider mites in trees means that control of T. urticae largely depends on T. pyri, a generalist predator that is not particularly effective in regulating T. urticae.

Intraoperative localization of ectopic gastric mucosa in the nonduplicated intestinal lumen with technetium 99m pertechnetate scanning.

The occurrence of ectopic gastric mucosa in Meckel's diverticula and duplications of the intestinal tract is a source of serious morbidity from bleeding and perforation in children. Intraoperative localization of the ectopic mucosa is aided by its occurrence in the duplicated intestinal segment or Meckel's diverticulum. However, its identification in the nonduplicated intestine poses problems for the surgeon faced with removal of the affected segment. The authors present a case of ectopic gastric mucosa in a nonduplicated jejunal segment and discuss the use of technetium 99m pertechnetate scanning in its localization.

Performance of a pyrethroid-resistant strain of the predator mite Typhlodromus pyri (Acari: Phytoseiidae) under different insecticide regimes.

An organophosphate pyrethroid-resistant strain of Typhlodromus pyri Scheuten imported from New Zealand was reared on potted apple trees in an outdoor insectary. From 1988 to 1995, the population was selected one to three times per year with a dilute solution (1.7 ppm) of the pyrethroid cypermethrin. Petri dish bioassays with cypermethrin in 1995 indicated that the insectary-reared T. pyri had an LC50 of 81 ppm versus 0.006 ppm for native T. pyri taken from a research orchard. The bioassays suggested that recommended orchard rates of cypermethrin would cause heavy mortality in native populations of T. pyri but only moderate losses in the imported New Zealand strain. Bioassays in 1996 with the organophosphate insecticide dimethoate indicated both New Zealand and native T. pyri were susceptible and that recommended orchard rates of dimethoate likely would cause high mortality of T. pyri in apple orchards. These findings from bioassays were supported by data from orchard trials. In June and July 1993, insectary-reared New Zealand T. pyri were placed on five apple trees in each of eight 38-tree plots in the research orchard. In late August 1994, New Zealand T. pyri from orchard trees that had been sprayed twice by airblast sprayer with the full recommended rate of 50 g (AI)/ha (83 ppm) cypermethrin were placed on the other 33 trees in each of six plots. In the summers of 1994-1996, plots were treated with one of the following insecticide regimes: (1) conventional integrated pest management (IPM) (registered neurotoxic insecticides considered harmless or slightly toxic to T. pyri); (2) advanced IPM (use of newer, more selective insecticides); (3) pyrethroid (at least one full-rate application of cypermethrin); (4) dimethoate; and (5) dimethoate plus pyrethroid. Densities of European red mite, Panonychus ulmi (Koch), were highest in all plots treated with dimethoate and in pyrethroid plots not yet inoculated with New Zealand T. pyri. Densities of apple rust mite, Aculus schlechtendali (Nalepa), and of the stigmaeid predator Zetzellia mali (Ewing) were highest in plots treated with dimethoate and were nearly absent in the IPM plots. Densities of T. pyri were high enough for effective biocontrol in the IPM plots and in the pyrethroid plots 1-2 yr after release of the New Zealand strain, provided pyrethroid was applied just before the resistant strain was released in the orchard. A recurring theme of this study was the generally negative association between densities of phytophagous mites and those of T. pyri, suggesting the ability of this predator to suppress their prey. In contrast, the positive association between phytophagous mites and Z. mali suggests the inability of this predator to regulate their prey at least under the conditions of this study.

Pollen availability for predaceous mites on apple: spatial and temporal heterogeneity.

It has been suggested that an abundance of alternate food early in the spring may be critical to the ability of generalist predaceous mites to suppress spider mite pests. One alternate food that is typically very abundant in spring is wind-dispersed pollen. Here we investigate, at several spatial scales, the heterogeneity in the availability of pollen to predaceous mites on apple. We found pollen to be abundant on apple leaves very soon after they opened (> 100 grains/cm2), and that the dominant pollen types at this time were wind-dispersed tree pollens (Betulaceae and Pinaceae). We found that most of the spatial variation in pollen abundance occurred at either small spatial scales (within trees) or very large spatial scales (among orchard blocks). Variability among orchards was clearly influenced by the surrounding vegetation, and probably also by the management regime (frequency of mowing). Spatial heterogeneity in pollen availability may affect the build-up of predatory mite populations in the spring, as we found early season abundances of Typhlodromus pyri (Phytoseiidae) and Zetzellia mali (Stigmaeidae) to be better correlated with early season pollen density than with abundance of mite prey (Aculus schlechtendali).

Idiopathic neonatal hepatitis associated with a fatal coagulopathy.

Idiopathic neonatal hepatitis (INH) remains a diagnosis of exclusion in the neonate with conjugated hyperbilirubinemia. The major diagnostic challenge for the clinician is to distinguish this condition from other treatable liver disorders such as biliary atresia. Although the prognosis varies for the familial and sporadic forms of neonatal hepatitis, a poor outcome is generally distinguished by chronic and progressive liver failure. After careful review of the literature, we were unable to find a case of INH associated with a profound, irreversible coagulopathy. Herein, we present a case with the primary presenting findings of persistent prolongation of the prothrombin time (PT) and hypofibrinogenemia, resulting in a catastrophic intracranial hemorrhage and death.

Lymph node classification systems in cutaneous T-cell lymphoma. Evidence for the utility of the Working Formulation of Non-Hodgkin's Lymphomas for Clinical Usage.

BACKGROUND: This study was undertaken to compare three classification schemes used to evaluate lymph nodes (LN) obtained from patients with cutaneous T-cell lymphoma (CTCL): a modified Rappaport classification, the National Cancer Institute-Veterans Administration (NCI-VA) classification based on the relative numbers of cerebriform cells in the paracortical areas, and the Dutch classification based on the presence of cerebriform cells with large nuclei in mycosis fungoides (MF) and diffuse infiltration by cerebriform cells in Sézary syndrome. METHODS: A study set of 195 LN obtained from patients with CTCL (MF, Sézary syndrome, and nonepidermotropic T-cell lymphomas) and 14 LN from patients with benign dermatoses was reviewed independently by three groups of pathologists familiar with each classification system. RESULTS: Each classification system provided useful prognostic information. However, contrary to prior reports, no significant difference in survival was apparent in patients with uneffaced LN when classified according to the NCI-VA (LN0-2 versus LN3) or Dutch (Gr0-1 versus Gr2) ratings. In addition, all classification systems demonstrated a poor survival time associated with effaced LN. By combining results from the modified Rappaport and Dutch classifications, three prognostic groups could be identified based on cell morphology: a low-grade category with a small cell histologic subtype (median survival time, 40 months); a high-grade immunoblastic subtype (median survival time, 9 months) composed of cells with an oval nucleus containing a large, usually solitary central nucleolus; and an intermediate-grade category composed of all cases without the distinctive small cell and immunoblastic morphologies (median survival time, 26 months). CONCLUSIONS: The authors propose that clearly involved LN in CTCL can be categorized on the basis of cell morphology into prognostic groups analogous to what has been proposed for the Working Formulation for Non-Hodgkin's Lymphomas for Clinical Usage.

Effects of nicardipine in rats subjected to endotoxic shock.

1. The calcium channel blocker, nicardipine, produced a dose-dependent reduction in the mortality caused by endotoxin in rats. 2. The drug also reduced most of the hematological and gross pathological manifestations of disseminated intravascular coagulation (DIC) caused by endotoxin. 3. The endotoxin-induced monocytopenia but not the granulocytopenia, lymphocytopenia or thrombocytopenia was inhibited by the drug. 4. The results suggest that the protective action of nicardipine is causally related to prevention of the endotoxin-induced DIC and that an effect of the drug on monocytes may be of importance.

The effects of the calcium entry blockers, nilvadipine and nitrendipine, on endotoxin-induced disseminated intravascular coagulation.

We previously reported that calcium entry blockers (CEBs) protected against endotoxin-induced mortality in rats. In this investigation, the i.v. injection of endotoxin (ETX) in control awake male Wistar rats was found to produce pathophysiological changes indicative of disseminated intravascular coagulation (DIC). The latter included increased serum fibrin (ogen) degradation products (FDP), decreased plasma fibrinogen, reduced blood platelet count as well as microscopic findings of fibrin microthrombi in small blood vessels of visceral organs. Gross pathological examination revealed pronounced hemorrhagic congestion of the gastrointestinal tract and petechial and ecchymotic hemorrhages in other visceral organs. Pretreatment with the CEBs, nilvadipine (FR 34235) and nitrendipine, inhibited the elevation in serum FDP and decrease in plasma fibrinogen but did not prevent the thrombocytopenia produced by ETX. The gross pathological manifestations of DIC were also inhibited by pretreatment with the CEBs. The results suggest that the protective effect of CEBs against endotoxin-induced mortality in rats may be related to inhibition of DIC caused by the lipopolysaccharide.

Objective relief of vasospasm by glyceryl trinitrate in secondary Raynaud's phenomenon.

An objective response to topical glyceryl trinitrate was shown by digital plethysmography in a study of 17 patients with Raynaud's phenomenon. Improvement was significant (P less than 0.005) in those in whom the disease was secondary to an underlying connective tissue disorder. The response suggests that the effect of this drug is mediated locally.

Eosinophilic radiculomyeloencephalitis: an angiostrongyliasis outbreak in American Samoa related to ingestion of Achatina fulica snails.

For the first time in American Samoa an outbreak of eosinophilic radiculomyeloencephalitis was related to eating giant African snails (Achatina fulica) infected with Angiostrongylus cantonensis. Among 24 Korean fisherman sharing the same infective meal, 16 who ate raw or partially cooked snails became ill; five who ate boiled snails and three who ate none remained well. The ensuing illnesses began within 1-6 days, persisted up to 10 weeks, and were characterized by both peripheral blood and spinal fluid eosinophilia, severe pains, weakness and hyporeflexia of the legs, and dysfunction of the bladder and bowels. Eight patients also had transient hypertension and/or lethargy, and three became comatose. One man died 17 days after eating the infected snails, and maturing larvae of A. cantonensis were found in his spinal cord. Enzyme-linked immunosorbent assay titers for antigens of A. cantonensis were elevated to 1:64 or greater (mean 1:128) in all 10 patients tested. Treatment with thiabendazole had no appreciable effect on the clinical course of the illness.

Immunocytochemical hormonal features of pituitary adenomas of aging Wistar male rats.

Pituitary adenomas were the most common grossly visible naturally occurring neoplasms found in over 27% of rats surviving beyond 17 months of age. Twenty-three pituitary adenomas, fixed in buffered neutral formalin and embedded in paraffin, were tested for the presence of prolactin (PRL), growth hormone (GH) and thyroid stimulating hormone (TSH) using the unlabeled peroxidase-antiperoxidase method. The adenoma cells in 6 (26%) of the 23 tumors stained with two or three of the tested hormones, but clear evidence that individual neoplastic cells contained more than one hormone was not found. These findings suggest that in aging male Wistar rats the spontaneous pituitary adenomas may originate from undifferentiated cells, PRL-, GH- and TSH-cells in a diminishing order of frequency.

Adenocarcinoma of the lung causing ectopic adrenocorticotropic hormone syndrome.

A patient with a left lower lung mass had muscle weakness, generalized hyperpigmentation, metabolic alkalosis, and profound hypokalemia. His elevated serum cortisol, corticosterone, and adrenocorticotropic hormone (ACTH) concentrations were not suppressed after midnight dexamethasone administration. Light and electron microscopic sections of the lung mass fitted the pathological criteria for adenocarcinoma. Immunocytochemical analysis of the tumor demonstrated specific staining with antibody to beta-endorphin, suggesting that the tumor cells made the common precursor molecule of ACTH, beta-lipotropin, and endorphin. This is, to the best of our knowledge, only the second case report of pulmonary adenocarcinoma associated with the syndrome of ectopic ACTH.

Microangiopathy of the brain and retina.

Two women (26 and 40 years old) developed an unusual microangiopathy that affected the brain and retina. Psychiatric symptoms initially overshadowed the subacute features of the progressive neurologic disorder. Ophthalmoscopic findings of multifocal branch retinal artery occlusions provided clinical evidence of vasculopathy. Laboratory data did not reveal evidence of the known vasculitides, including systemic lupus erythematosus (SLE) and syphilis. Cerebral angiography suggested vasculitis in the younger patient. Brain biopsy in the older patient (after 3 months of steroid therapy) revealed a sclerosis of the small pial and cortical vessels that was consistent with a "healed" angitis. Both patients seemed to respond to steroid therapy.

Pituitary oncocytoma. Indispensable role of electron microscopy in its identification.

Two surgically resected pituitary adenomas that appeared to be chromophobe or poorly granulated acidophil adenomas by light microscopy were correctly identified as oncocytomas by electron microscopy. The tumor cells ahd markedly hyperplastic, moderately pleomorphic mitochondria in the cytoplasm of virtually all cells. Scattered secretory granules were displaced to the periphery of the cytoplasm but the secretion type of pituitary cell remained obscure. Histochemical and immunocytochemical methods imperfectly characterized these unusual tumors. Even though these neoplasms have been considered rare, they are now being recognized more often after ultrastructural study. Eventually their pathobiologic features may be better understood. One of our patients was 24 years old and is the youngest patient, to our knowledge, in whom a pituitary oncocytoma has been documented.

Retroperitoneal germinoma marked by elevated serum lactic dehydrogenase.

A case of primary retroperitoneal germinoma is presented in which markedly elevated serum lactic dehydrogenase levels were present before diagnosis, but declined to normal with abdominal irradiation. It is the first report of lactic dehydrogenase serving as a tumor marker in germinoma.