A cost-benefit assessment of Salmonella-control strategies in pigs reared in the United Kingdom.

Pork and pork products are a major source of human salmonellosis in the United Kingdom (UK). Despite a number of surveillance programmes, the prevalence of Salmonella in the UK slaughter pig population remains over 20%. Here, we present the results of a Cost-Benefit Analysis comparing five on-farm control strategies (where the cost is the cost of implementation and the benefits are the financial savings for both the human health and pig industries). The interventions considered were: wet feed, organic acids in feed, vaccination, enhanced cleaning and disinfection and movement of outdoor breeding units. The data originate from published papers and recent UK studies. The effectiveness was assessed by adapting a previous risk assessment, originally developed for the European Food Safety Authority. Using this method, none of the intervention strategies produced a net cost-benefit. Our results suggest that the cost of implementation outweighed the savings for all interventions, even if the effectiveness could be improved. Therefore, to achieve a net cost-benefit it is essential to reduce the cost of interventions. Analyses concluded that large cost reductions (up to 96%) would be required. Use of organic acids required the smallest reduction in cost (22.7%) to achieve a net cost benefit. Uncertainty analysis suggested that a small net gain might be possible, for some of the intervention measures. But this would imply that the model greatly underestimated some key parameters, which was considered unlikely. Areas of key uncertainty were identified as the under-reporting factor (i.e. the proportion of community cases of Salmonella) and the source attribution factor (i.e. the proportion of human Salmonella cases attributable to pork products).

Traumatic bilateral carotid dissection with concomitant cerebral infarction.

A 40-year-old man presented with a major nondominant hemisphere stroke syndrome after a road traffic accident. Cranial computed tomography scan revealed an extensive right hemisphere infarction involving the entire anterior and middle cerebral artery territories. Duplex Doppler ultrasound and cerebral angiography revealed bilateral internal carotid artery dissection with evidence of underlying fibromuscular dysplasia. Anticoagulation with heparin was commenced despite the coexisting large cerebral infarction, with the objective of protecting the uninjured but at-risk left cerebral hemisphere from ischemic injury. Patients with multiple cerebral arterial dissections complicated by cerebral infarction present a significant management dilemma. Our literature review revealed a lack of clear management guidelines for such cases.

Behavioral treatments for post-prostatectomy incontinence.

Despite improvements in surgical approaches to radical prostatectomy, many patients experience moderate to severe urinary incontinence during the first few postoperative weeks. For some patients, leakage continues for several months or years. Urinary incontinence has a significant impact on quality of life in these typically active patients. Surgical interventions are not recommended until after a 6 to 12 month trial of behavioral interventions. Behavioral interventions include supportive care, diet and medication management, pelvic floor rehabilitation, inhibition techniques, and patient education and support. This integrative review of the literature summarizes current knowledge of behavioral interventions for post-prostatectomy urinary incontinence for the primary care and home care clinician. Aspects of care specific to masculine culture are explored. Recommendations for further research include determination of optimal timing and protocols for pelvic floor rehabilitation, best practices for patient and family education, and development of a standard definition of urinary incontinence so the efficacy of treatments can be compared.

Randomized double-blind study comparing the efficacy of gabapentin with amitriptyline on diabetic peripheral neuropathy pain.

BACKGROUND: Reports of gabapentin use in diabetic peripheral neuropathy pain stimulate a need for controlled trials to determine its comparative efficacy to the therapeutic standard of amitriptyline hydrochloride. OBJECTIVE: To determine the efficacy of gabapentin compared with amitriptyline in treating diabetic peripheral neuropathy pain. DESIGN: Prospective, randomized, double-blind, double-dummy, crossover study. SETTING: Veterans Affairs San Diego Healthcare System, Ambulatory Care Clinic. PATIENTS: Twenty-eight veterans were referred by their primary care providers. Two patients withdrew before randomization because of no neuropathic pain after washout; a third withdrew for unexpected surgery that required analgesics. Three patients withdrew because of adverse effects and 1 for protocol violation. INTERVENTIONS: Patients with stable glycemic control and neuropathic pain randomized to 6 weeks of therapy with gabapentin, 900 to 1800 mg/d, or amitriptyline hydrochloride, 25 to 75 mg/d, with a 1-week washout before crossover. MAIN OUTCOME MEASURES: Pain relief measured by pain scale with verbal descriptors and global pain score assessment at treatment end. RESULTS: Participants and investigators were blinded throughout. Mean dosages were of gabapentin, 1565 mg/d, and of amitriptyline hydrochloride, 59 mg/d. Sixty-five percent of patients reached maximum dose with gabapentin and 54% with amitriptyline. Mean score diary analysis showed pain relief with gabapentin and amitriptyline was not significantly different (P = .26). Global data were obtained from 21 of 25 enrolled patients who completed the study. Moderate or greater pain relief was experienced in 11 (52%) of 21 patients with gabapentin and 14 (67%) of 21 patients with amitriptyline. There were no significant period or carry-over effects (P = .35). CONCLUSIONS: Although both drugs provide pain relief, mean pain score and global pain score data indicate no significant difference between gabapentin and amitriptyline. Gabapentin may be an alternative for treating diabetic peripheral neuropathy pain, yet does not appear to offer considerable advantage over amitriptyline and is more expensive. Larger trials are necessary to define gabapentin's place in treating diabetic peripheral neuropathy pain.

Pilocytic astrocytoma presenting as an extra-axial tumor in the cerebellopontine angle: case report.

Glial tumors in the cerebellopontine angle (CPA) are rare. Four histologically distinct types of glial tumors of the CPA have been described in the literature as ependymoma, medulloblastoma, mixed glial tumor, and fibrillary astrocytoma. This case report describes a pilocytic astrocytoma of the CPA. A 58-year-old man with a hearing loss had an extra-axial tumor in the left CPA that extended into the internal auditory canal. The characteristics of the tumor on magnetic resonance imaging scans differed from those of typical CPA tumors. It adhered avidly to the cochlear and vestibular nerves, which had to be sacrificed for gross total resection. Microscopic examination showed the typical features of an adult-type pilocytic astrocytoma.

Multiple plasma cell granulomas of the central nervous system: case report.

Plasma cell granulomas of the central nervous system are exceedingly rare. Of the six well-documented cases that have been published to date, five plasma cell granulomas were intracranial and one was located in the spinal meninges. Multiple plasma cell granulomas of the central nervous system have not previously been reported. We now report a patient who had two plasma cell granulomas in the spinal meninges and one in the anterior cerebral falx. The histological findings that differentiate this rare lesion from other central nervous system lesions, such as plasmacytoma and meningioma, are discussed with a review of the literature.

Inhibition of macrophage chemotaxis and peripheral nerve regeneration in normal and hyperglycemic rats by the aldose reductase inhibitor Tolrestat.

This study examined the effect of Tolrestat, an inhibitor of aldose reductase, on the regenerative capacity and macrophage chemotactic property of crush-injured sciatic nerve in normal and galactose-fed rats. Galactose intoxication reduced the incidence of regeneration but did not alter the regeneration distance or the injury-induced increase in vasoactive intestinal polypeptide content of dorsal root ganglia. Tolrestat improved the incidence of regeneration in galactose-fed rats but significantly (P < 0.05) reduced the distance of nerve regeneration in both control and galactose-fed rats. Galactose intoxication enhanced the ability of homogenates of nerve undergoing Wallerian degeneration to attract macrophages, whereas chemotaxis toward nerve homogenates from Tolrestat-treated rats was absent. Tolrestat, but not the structurally dissimilar aldose reductase inhibitors Ponalrestat and Sorbinil, exhibited a reversible, dose-dependent inhibition of macrophage chemotaxis induced by polyinosinic acid. These data suggest that exaggerated sugar metabolism by aldose reductase may restrict the ability of nerve to initiate regeneration but is not responsible for the reduced distance of nerve regeneration or attenuated increase in vasoactive intestinal polypeptide production that occur after crush injury of diabetic rats. Inhibition of macrophage responses to chemotactic signals by Tolrestat may impede regeneration and other reparative mechanisms.

Relative neural toxicity of local anesthetics.

In rat sciatic nerve, relative neural toxicity and relative motor nerve conduction blockade were assessed for two amide-linked local anesthetics (etidocaine and lidocaine) and two ester-linked local anesthetics (chloroprocaine and procaine). As measures of neural toxicity, nerve fiber injury and edema were assayed by light microscopic examination of nerve tissue sampled 2 days after perineural (next to the sciatic nerve) injection of various concentrations of the local anesthetics. Both nerve injury and edema increased with concentration of local anesthetics, but injury was frequently present in nerve fascicles with little or no edema. In parallel studies, the amplitude of the electrical activity elicited from the interosseous muscles of the foot following ipsilateral electrical stimulation at the sciatic notch was monitored for up to 15 minutes to assess the extent of motor nerve blockade. The resulting log concentration-response curves were analyzed for differences in potency. Both for injury and for conduction block, the order of decreasing potency was: etidocaine, lidocaine, chloroprocaine, procaine. These results are not consistent with the proposal that ester-linked agents are more likely than other local anesthetic agents to cause nerve injury.

Peripheral nerve lesions in HTLV-I associated myelopathy (HAM/TSP).

Peripheral nerve dysfunction (PND) was found in as many as 43% of our patients with human T-cell lymphotropic virus type I (HTLV-I)-associated myelopathy (HAM/TSP). To evaluate the PND further we biopsied the sural nerve in 6 patients. The histological features were varying degrees of demyelination, remyelination, axonal atrophy and degeneration, and perineurial fibrosis. "Globule" or "sausage" formation was prominent in two of the specimens. Inflammatory infiltrates were absent. No deposits of IgG, IgM, IgA, or complement were detected in the biopsies. No viral antigen or proviral DNA was detected. It is proposed that the PND and the histological findings noted are part of HTLV-I-associated disease and not an unrelated disorder. The pathogenesis of the PND remains unclear. There was no evidence of direct viral infection. The histological findings could represent primary changes induced by viral-triggered release of soluble factors, such as cytokines or secondary changes to more proximal disease, e.g., root involvement.

Spinal cord infarction caused by cartilage embolus to the anterior spinal artery.

Cartilaginous embolization of spinal vessels is a rare cause of spinal cord infarction. A 63-year-old woman developed sudden onset of painful, fatal paraparesis following a valsalva-like maneuver. Autopsy demonstrated recent nonhemorrhagic infarction of the caudal thoracic spinal cord secondary to complete occlusion of the anterior spinal artery by cartilage. The literature pertaining to 28 previously reported cases is briefly reviewed.

Case report: solitary haemangioblastoma of the fourth ventricle in an adolescent male.

We report a solitary haemangioblastoma arising from a pedicle in the wall of the fourth ventricle of the brain, which we believe to be the first report of haemangioblastoma occurring in this location. Computed tomography (CT), angiography and magnetic resonance imaging (MRI) made possible accurate pre-operative tumour identification and localization which facilitated a minimally invasive surgical resection.

Immunotactoid-like endoneurial deposits in a patient with monoclonal gammopathy of undetermined significance and neuropathy.

An 85-year-old man with a 2-year history of progressive lower limb weakness and paresthesia was found to have an IgG kappa monoclonal gammopathy of undetermined significance (mgus). Clinical and electrophysiological studies revealed a severe distal bilateral symmetrical polyneuropathy. A sural nerve biopsy showed extensive nerve fibre loss with the deposition of large amounts of amorphous material throughout the endoneurium. Electron microscopy showed the deposits to be composed of microtubular structures which were located diffusely throughout the endoneurium. The deposits were also located within the lumina of the vasa nervorum, some of which were undergoing disintegration and rupture with release of the proteinaceous material into the endoneurium. The regions of the nerve in which they appeared most numerous showed more severe nerve fibre damage than other areas. These microtubular structures were also observed in disintegrating vessels and adjacent endoneurium. On immunohistochemistry they stained with antibody to IgG. Identical deposits were found in the dermis in which there was a leucocytoclastic vasculitis. Located in linear arrays within the axons of myelinated and unmyelinated fibres were highly organised tubular structures resembling immunotactoids. Identification of immunotactoid-like structures within the nerve is unique and may be another mechanism by which monoclonal proteins can induce nerve fibre injury.

Reactions to argasid tick bites by island residents on the Great Barrier Reef.

OBJECTIVE: To attribute a cause and quantify allergic-like symptoms observed among island residents. DESIGN: Skin prick tests and intradermal injections with ultraviolet-irradiated, filtered (0.22 microns) whole-body homogenates of the soft tick, Ornithodoros capensis, were used to reproduce experimentally the symptoms observed. SETTING: Heron Island, Great Barrier Reef, Australia. PARTICIPANTS: Island residents were designated as such after having spent more than 1 month on the island during the summer seabird breeding season. INTERVENTIONS: Control measures were instigated using a residual insecticide, delta-methrin, sprayed inside sleeping quarters. MAIN OUTCOME MEASURES: Acaricide spraying reduced (X2 = 4.42; P less than 0.05) the number of island residents complaining of having been bitten by ticks, yet was considered an inefficient control measure as 67% reported being attacked by ticks after spraying. RESULTS: Among 97 island residents, elevated total IgE levels were associated with reaction to tick bite in 11 cases (X2 = 27.17; P less than 0.001), but were not of reliable diagnostic value. Symptoms included intense pruritus, blistering (a major feature), erythema, weeping lesions, lymphangitis, dull ache, rheumatic pain and general lassitude, and intense discomfort. Sera from two of four volunteers with known reactions to O. capensis and one of four others with reactions to the Australian paralysis tick, Ixodes holocyclus, cross-reacted with antigens from a total of four of six biting/stinging and non-biting arthropods (radioallergosorbent tests). CONCLUSIONS: Symptoms associated with reactions to tick bite peaked in severity at 35-40 hours and thus the response was most likely delayed type IV hypersensitivity.

Toxocariasis--an unlikely cause of Palm Island mystery disease.

After the suggestion was made that the "Palm Island mystery disease" might have been an epidemic of visceral larva migrans that was caused by the flying fox parasite, Toxocara pteropodis, work was undertaken to elucidate this nematode's life-cycle and pathogenicity. Studies of infections in various laboratory animals have shown unexpectedly variable susceptibility patterns, with mice harbouring most larvae for the longest time period. However, in all susceptible animals (which include mice, guinea-pigs and suckling rats), the larvae demonstrated marked hepatotropism. Experimental infections in monkeys demonstrated that primates are susceptible to this infection, but large doses of 20,000 infective eggs produced blood eosinophilia and focal granulomatous hepatitis without clinical disease or biochemical abnormalities in the blood. It is concluded that humans are susceptible to larval infections with this nematode, but that clinical manifestations would be unlikely to develop.

Factors affecting the development of Dipylidium caninum in Ctenocephalides felis felis (Bouché, 1835).

Ctenocephalides felis felis larvae were infected with Dipylidium caninum at a range of temperatures from 20 degrees - 35 degrees C at 3 mm Hg saturation deficit (SD) and 30 degrees C at 8 mm Hg SD. Hosts were subsequently dissected at 6, 9 and 12 days after infection. Four replicate experiments were performed and results of development, and host reactions analysed by the Genstat computer programme. These were found to depend on the temperature and saturation deficit of the environment. Unlike previous findings, parasite development and host reaction were found to be independent of host development. Host reaction was more marked and prolonged at 20 degrees - 25 degrees C than at higher temperatures. No perceptible growth of the parasite occurred at 20 degrees C. The development patterns of growth at the higher temperatures were similar but shifted in time so that faster growth occurred at higher temperatures. Rate of growth was fastest at 35 degrees C, despite the fact that this temperature was unfavourable to the hosts, all of which died at the time of pupation.