Sodium metasilicate affects growth of Campylobacter jejuni in fresh, boneless, uncooked chicken breast fillets stored at 4 degrees Celsius for 7 days.

The objectives of this study were to determine the antimicrobial effects of sodium metasilicate (SMS) treatments against Campylobacter jejuni in fresh, boneless, uncooked chicken breast fillets and to ascertain the effects of SMS treatments on pH. The fillets were inoculated with C. jejuni, treated with 0% SMS and no inoculum (negative control), 0% SMS and inoculum (positive control), 1 and 2% SMS solutions, and stored at 4 ± 1°C. All samples were analyzed after 0, 1, 3, 5, and 7 d storage for C. jejuni, psychrotrophic organisms, and pH. Campylobacter jejuni and psychrotrophic counts for samples treated with 1 and 2% SMS solutions were similar (P > 0.05) to the positive control on all storage days. The pH values for 2% SMS marinade treatments were higher (P < 0.05) when compared with the negative and positive controls through 7 d of storage. Based on the findings in this study, a second study was conducted to determine the level of SMS necessary to reduce C. jejuni by at least 1 log cfu/g. The treatments were the same as previously discussed, except SMS was used at levels of 1 and 2% of the weight of the meat instead of percentage of the solution. Chicken fillets treated with 1 and 2% SMS (by weight of meat) resulted in 1.12 to 1.26 and 3.27 to 3.79 log cfu/g reductions in C. jejuni, respectively, when compared with the positive control. Except for d 0, psychrotrophic counts for samples treated with 2% SMS were lower (P < 0.05) than negative and positive controls on all storage days. The pH values were higher (P < 0.05) for all SMS treatments when compared with the negative and positive controls. This study revealed that SMS, when used at elevated levels in excess of the USDA Food Safety and Inspection Service 2% approved level, could function to control Campylobacter jejuni and extend the shelf life of raw poultry by retarding the growth of psychrotrophic bacteria.

Sodium metasilicate affects growth of Salmonella Typhimurium in fresh, boneless, uncooked chicken breast fillets stored at 4°C for 7 days.

The objectives of this study were to determine the antimicrobial effects of sodium metasilicate (SMS) against Salmonella and psychrotrophic organisms in fresh, boneless, uncooked chicken breast fillets and to ascertain the effects of SMS treatments on pH. Chicken breast fillets were inoculated with Salmonella enterica serovar Typhimurium treated with 0% SMS and no inoculum (negative control), 0% SMS and inoculum (positive control), 1% SMS, or 2% SMS solutions and stored at 4 ± 1°C. All samples were analyzed after 0, 1, 3, 5, and 7 d for Salmonella, psychrotrophic organisms, and pH. The fillets that were treated with 1 or 2% SMS had lower (P < 0.05) Salmonella counts as compared with those of the positive control at 3 through 7 d. Reductions in Salmonella Typhimurium were 0.83 to 0.91 log cfu/g and 1.04 to 1.16 log cfu/g for 1 and 2% SMS treatments, respectively. The psychrotrophic counts were similar (P > 0.05) for all treatments. The pH values for samples treated with 1 or 2% SMS were higher (P < 0.05) when compared with those of the negative and positive controls. This study revealed that SMS could restrict the growth of pathogenic Salmonella Typhimurium in fresh poultry.

Intrasinus catheter-directed heparin infusion in the treatment of dural venous sinus thrombosis.

BACKGROUND AND PURPOSE: In this small series, local intrasinus catheter-directed heparin infusion with or without balloon thrombectomy was safe in the treatment of dural venous sinus thrombosis (DVST). Although systemic anticoagulation (SAC) is the treatment of choice, there is a lack of consensus regarding the best treatment should SAC fail or be contraindicated. We present our institutional experience with 16 patients in whom failure of, or contraindication to, SAC occurred and who subsequently underwent intrasinus catheter-directed heparin infusion with or without balloon thrombectomy. MATERIALS AND METHODS: A retrospective review of 16 patients ranging in age from 14 days to 77 years who had intrasinus catheter-directed heparin infusion was undertaken with 9 male and 7 female patients identified. Of these 16 patients, 4 (25%) had a contraindication to SAC and SAC failed in 12 (75%). Technically successful intrasinus infusion catheter placement was achieved in all 16 patients (100%). Mean duration of infusion was 3.3 days (range, 1-6 days). Adjunctive balloon thrombectomy was performed in 9 (56.3%) of 16 patients. No procedure-related mortality occurred. RESULTS: Partial and complete sinus recanalization occurred in 10 (62.5%) of 16 patients and 1 (6.3%) of 16 patients, respectively. There were 3 deaths (18.8%) attributed to disease progression. At most recent clinical follow-up (mean, 9.3 months), 11 (84.6%) of 13 surviving patients were independent, with a modified Rankin Scale (mRS) score of 1 or less. CONCLUSIONS: Local intrasinus catheter-directed heparin infusion with or without adjunctive balloon thrombectomy seems to be a safe and effective treatment of DVST in patients in whom SAC failed or in whom there was a contraindication to SAC. In addition, the risk for symptomatic intracranial hemorrhage may be significantly lower than intrasinus infusion of thrombolytics.

Compressive optic neuropathy caused by renal osteodystrophy. Case report.

Compressive optic neuropathy with acute or chronic vision loss has been associated with various skull base tumors, aneurysms, Graves disease, trauma, and, less commonly, fibrous dysplasia and osteopetrosis. The authors present a case of acute visual deterioration in a 25-year-old woman who had massive calvarial hypertrophy with optic canal stenosis secondary to renal osteodystrophy (uremic leontiasis ossea [ULO]: bighead disease). Significant visual field restoration was achieved with high-dose corticosteroids followed by optic nerve decompression. This is the first case report of cranial neuropathy associated with ULO.

Cognitive impairment and synaptosomal choline uptake in rats following impact acceleration injury.

Traumatic brain injury is well known to cause deficits in learning and memory, which typically improve with time. Animal studies with fluid percussion or controlled cortical impact injury have identified transient disturbances in forebrain cholinergic innervation which may contribute to such cognitive problems. This study examines the extent to which water maze performance and forebrain synaptosomal choline uptake are affected one week after injury using the newly developed impact acceleration injury model. Injury or sham injury was delivered to adult male Sprague-Dawley rats under halothane anesthesia using a 500-g 2.1-m weight drop. Based on righting reflex, injured rats were divided into moderate (< or = 12 min) or severe (>12 min) groups. Water maze testing was performed on days 5-7 postinjury. On day 7, choline uptake was determined in synaptosomes from hippocampus, a parietal cortex, and entorhinal cortex. Maze learning was severely impaired in the severe injury group but not in the moderate injury group. Learning retention was slightly impaired in the moderate injury group and severely affected in the severe injury group. There was a very strong correlation between the severity of injury as determined by prolongation of righting times and disruption of maze learning at 1 week postinjury. There was no change in synaptosomal choline uptake in any of the forebrain regions in the severe injury group, but a slight (14%) decrease in the hippocampus and parietal cortex of the moderate injury group. Correlation analysis showed no relationship between synaptosomal choline uptake in any brain region and performance in either water maze learning or retention. This study shows that the impact acceleration model produces cognitive impairments equivalent to those seen with fluid percussion injury and controlled cortical impact. Compared with those models, the impact acceleration model does not produce a similar disruption of forebrain cholinergic nerve terminals.

Recovery of water maze performance in aged versus young rats after brain injury with the impact acceleration model.

Clinically, elderly patients have a higher cognitive morbidity from head trauma than young patients. We have modeled injury in aged rats in an effort to elucidate the pathophysiology of this enhanced sensitivity and, in particular, to determine if there are susceptibility differences in forebrain cholinergic innervation in young versus aged rats. Aged (20-23 months) and young (2-3 months) rats were subjected to injury under halothane anesthesia using the Marmarou impact acceleration model. Injury parameters required adjustment downward for the aged rats (323 g at 1.61 m versus 494 g at 2.06 m) to provide equivalent mortality (30% versus 20%) and loss of righting-reflex times (10-12 min average). At 1 week following injury, the aged animals were markedly more impaired in water maze performance than were young rats, and this difference persisted at least up to 5 weeks following injury. The extent of improvement in performance from 1 to 5 weeks was markedly worse for aged animals compared to young animals. Forebrain synaptosomal choline uptake was decreased in aged injured rats by 8-14% at 1, 3, and 5 weeks postinjury, but not decreased in young injured rats. No differences were noted in entorhinal cortex or hippocampal choline uptake. This model effectively demonstrates the markedly increased susceptibility of older animals to head injury and their decreased capacity for recovery. The neurophysiological basis for this difference is presently unknown, but the differences in cognitive dysfunction between young and aged rats appears to be much greater than would seem to be explained by the small differences in forebrain cholinergic innervation.

[Spontaneous remission of Goodpasture syndrome in a 21-year-old patient]. / Spontanremission eines Goodpasture-Syndroms bei einem 21jährigen Patienten.

HISTORY AND CLINICAL FINDINGS: A 21-year-old man was admitted twice within half-a-year because of fatigue and increasing dyspnoea. Both times the chest x-ray showed extensive pulmonary infiltrates. Clinical remission occurred within a few days of starting antibiotic treatment. INVESTIGATIONS: During the second admission an increased titre for antibodies against glomerular basement membrane was discovered (2560 U/ml); renal functions were normal, but there was haematuria. Renal biopsy revealed linear deposits of IgG along the glomerular basement membrane. DIAGNOSIS, TREATMENT AND COURSE: The pattern of findings indicated Goodpasture's syndrome. Immunosuppressive treatment and plasma separation did not have to be performed because spontaneous remission occurred within a few days. CONCLUSION: This case demonstrates that spontaneous remission may occur in Goodpasture's syndrome.

Use of a microvascular Doppler probe to avoid basilar artery injury during endoscopic third ventriculostomy. Technical note.

Basilar artery (BA) injury has been reported in a number of cases as a major complication of third ventriculostomy for hydrocephalus. This report describes the deployment of a pulsed-wave microvascular Doppler probe through the endoscope to locate the BA complex and subsequently to select a safe zone for perforation of the third ventricular floor. This procedure is quick and easily learned, and it is hoped that it can decrease the risk of vascular injury during third ventriculostomy.

Microbial, physical, and chemical quality of packaged ice in Florida.

In a statewide survey, ice samples purchased at retail were evaluated for labeling information and microbiological, chemical, and physical quality. Only 11% of bags from on-premises manual facilities, compared to 79% for off-premises mechanical facilities, had appropriate label information. One ice sample exceeded the state regulatory limit for aerobic plate count (APC) (<500 CFU/ml). Yeasts and molds were detected in 12% of the samples. No Listeria monocytogenes were found in any of the samples. Coliform counts exceeding the state regulatory limit (<1/100 ml) were observed in 13.5% of manual, on-premises facilities compared to 3.6% of samples from mechanical, off-premises facilities. No significant differences were detected between samples from on- and off-premises facilities with regard to chemical composition (e.g., aluminum, ammonium, boron, barium, calcium, cadmium, chloride, copper, iron, lead, magnesium, manganese, nickel, nitrate, phosphorus, potassium, sodium, silicon, and zinc), electrical conductivity, or pH. All samples analyzed were in compliance with appropriate Environmental Protection Agency drinking water standards. In general, all ice samples were acceptable in terms of water hardness values. Approximately 33% of samples from off-premises facilities and 62% of the on-premises samples had detectable particulate matter. None of the off-premises samples, compared to 8% of the on-premises samples, had particulate matter in the "pronounced" category.

Time course for recovery of water maze performance and central cholinergic innervation after fluid percussion injury.

This study further investigates the possible connection between postconcussive cognitive impairment and damage to forebrain cholinergic innervation. Moderate parasagittal fluid percussion injury was delivered to adult male rats. Water maze performance and synaptosomal choline uptake was measured at various times following injury. Water maze learning was severely impaired between 1 and 5 weeks, but recovered to normal by 10 weeks. Synaptosomal choline uptake was significantly decreased by 15-27% in the ipsilateral hippocampus and parietal cortex 3 and 7 days following injury, but not by 3 weeks or thereafter. Choline acetyltransferase was also significantly decreased in the ipsilateral cortex at 3 and 7 days with subsequent recovery. This study shows that parasagittal fluid percussion injury causes significant impairment in water maze learning and ipsilateral forebrain cholinergic innervation. Both of these parameters recover spontaneously, but with different time courses.

Flavor avoidance learning and its implications in reducing strychnine baiting hazards to nontarget animals.

In reforested areas, underground strychnine baiting to control pocket gophers (Thomomys mazama) poses a hazard to golden mantled ground squirrels (Spermophilus lateralis) and yellow pine chipmunks (Eutamias amoenus). We designed this study to assess whether: 1) chemical insensitivity to bitter tastes might explain the ingestion of strychnine; 2) pocket gophers would avoid four bitter-tasting compounds: quebracho (QUEB), sucrose octaacetate (SOA), quinine hydrochloride (QHCl), and denatonium benzoate (DB); and 3) nontarget species could be trained to avoid strychnine paired with the most aversive compound. Our results showed that while all species readily consumed strychnine, the nontarget species could be conditioned to avoid it. Moreover, while high (0.1%) concentrations of DB, quinine hydrochloride, and quebracho reduced consumption by pocket gophers, 0.05% DB was inoffensive. Nontarget animals readily avoided 0.05% DB, and avoidance was stronger after conditioning. Together, our results suggest that all of the rodents tested are insensitive to strychnine, high concentrations of some bitter tastes may be effective pocket gopher repellents, and lower concentrations of DB may selectively repel nontarget animals from strychnine baits.

Loss of forebrain cholinergic neurons following fluid-percussion injury: implications for cognitive impairment in closed head injury.

Disturbances in memory, concentration, and problem solving are common after even mild to moderate traumatic brain injury. Because these functions are mediated in part by forebrain cholinergic and catecholaminergic innervation, in this study the authors sought to determine if experimental concussive injury produces detectable morphological damage to these systems. Fluid-percussion head injury, sufficient to cause a 13- to 14-minute loss of righting reflex, was produced in rats that had been anesthetized with halothane. Injury was delivered either at midline or 2 mm off midline and compared with appropriate sham-injured controls. After 11 to 15 days, the rat brains were stained in serial sections for choline acetyltransferase, tyrosine hydroxylase, dopamine beta-hydroxylase, acetylcholinesterase, and nicotinamide adenine dinucleotide phosphate diaphorase. Cell counts were determined for the entire population of ventrobasal forebrain cholinergic cells. Midline injury produced a bilateral loss of cholinergic neurons averaging 36% in area Ch1 (medial septal nucleus), 45% in Ch2 (nucleus of the diagonal band of Broca), and 41% in Ch4 (nucleus basalis of Meynart), (p < or = 0.05). Lateralized injury resulted in cholinergic neuron loss of similar magnitude ipsilaterally (p < or = 0.05), but a smaller contralateral loss of between 11% and 28%. No loss of neurons was detected in the pontomesencephalic cholinergic groups Ch5 and Ch6. There was no visible effect of head injury on forebrain dopamine or noradrenergic innervation. A significant and apparently selective loss of ventrobasal forebrain cholinergic neurons following brief concussive injury in rats is demonstrated in this study. This type of injury is known to produce significant disturbance in cognitive tasks linked to neocortical and hippocampal cholinergic function. It remains to be determined how this neuron loss occurs, whether it can be prevented with neuroprotective agents, how it affects innervation in target tissues, and whether it occurs in human victims of traumatic brain injury.

Osteolysis: new polymers and new solutions.

The prevention of osteolysis is a complex problem with multiple variables. Polyethylene represents one half of the bearing surface. Femoral head size, component congruency, and bearing material play a dominant role in the generation of particulate debris. In addition to all of these variables, there is a significant individual variation of biological response to a given particulate load. The industry-wide effort to improve the overall quality of manufactured polyethylene products and the introduction of Hylamer as a polyethylene bearing surface represent a significant step forward in reducing the problems of osteolysis in the next generation of implant patients.

Regional patterns of blood-brain barrier breakdown following central and lateral fluid percussion injury in rodents.

In order to determine how fluid percussion injury (FPI) effect is distributed throughout the brain, and to assess the extent to which individual brain nuclei and regions are affected, the pattern of blood-brain barrier (BBB) breakdown was determined in groups with different injury cannula locations. Injury cannulas were placed either at midline, or 2 or 4 mm to the side. One hour following FPI, animals were given horseradish peroxidase (HRP) and the brains were stained using the TMB method. The distribution of HRP leakage varied considerably depending upon the location of the injury cannula, however, there were also common sites of leakage among these groups. Locally the cortex and hippocampus under and adjacent to the injury cannula were heavily affected, with a clear asymmetric effect in the lateral cannula groups. Common sites of leakage included the dorsal thalamus, septal area, pontine tegmentum, periaqueductal gray, substantia nigra, and narrow zones adjacent to ventricular or cisternal surfaces. The hippocampus tended to be involved at greater distances than the cerebral cortex. The cervicomedullary junction proved to be especially vulnerable to FPI with extensive HRP leakage, and petechial hemorrhage ranging from minor to fatal coalescent hemorrhage. A very narrow threshold separated these outcomes. Neurologic impairment of the animals correlated most directly with the extent of cervico-medullary junction injury. Thus FPI produces a mix of local and diffuse effects on the BBB. Injury at the cervicomedullary junction is a prominent effect and is the limiting factor in trying to establish more severe diffuse injury.

Acute cauda equina syndrome from a ruptured aneurysm in the sacral canal. Case report.

The case is presented of a young woman with acute cauda equina syndrome from a ruptured aneurysm in the sacral canal. The lesion was associated with pathological enlargement of the lateral sacral arteries bilaterally, which presumably occurred to provide cross-pelvic collateral flow in response to the diversion of the right internal iliac artery for renal transplantation. The patient presented with signs and symptoms of spontaneous spinal epidural hemorrhage. The radiographic features of this lesion are described. In addition to angiography and partial embolization of the vascular supply, contrast-enhanced high-resolution computerized tomography was essential in the diagnosis and treatment of this unique aneurysm.

Cortical mapping and local anaesthetic resection as an aid to surgery of low and intermediate grade gliomas.

We report four cases of the use of peroperative cortical mapping during craniotomy under local anaesthesia to define the relationship between the glioma and speech and somatosensory cortex. This enabled a radical subtotal (two cases) or an apparent total (two cases) excision of the tumour close to the somatosensory and speech cortex with no permanent neurological deficit. Use of this technique allows radical excision of intrinsic low and intermediate grade gliomas that would otherwise be considered unexcisable and may lead to an improved survival.

Physiological evaluation of stimulated growth of Listeria monocytogenes by Pseudomonas species in milk.

Experiments were designed to elucidate a possible physiological mechanism for stimulated growth of Listeria monocytogenes by Pseudomonas fluorescens in milk. The ability of L. monocytogenes to grow in milk under aerobic and microaerophilic environments was compared. Neither environment favored the growth of the organism at 10 degrees C. Autoclaved whole milk was inoculated with P. fluorescens P26 and preincubated for 3 days at 10 degrees C followed by inoculation with L. monocytogenes Scott A and further incubation for 8 days at 10 degrees C. Changes in selected milk components were monitored over the 8-day period. The amount of lactose in the milk was determined, as well as the extent of proteolysis and lipolysis. Both L. monocytogenes and P. fluorescens were able to hydrolyze milk fat but were unable to use lactose. Milk protein was hydrolyzed by P. fluorescens but not by L. monocytogenes. Whole milk partially proteolyzed by treatment with purified protease was inoculated with L. monocytogenes. Results indicated that the growth of L. monocytogenes was stimulated in proteolyzed milk. This is the first report to provide evidence describing a likely mechanism for commensalism between L. monocytogenes and Pseudomonas spp.

Cortical mapping and resection under local anaesthetic as an aid to surgery of low and intermediate grade gliomas.

We report four cases of the use of per-operative cortical mapping during craniotomy under local anaesthesia to define the relationship between the glioma and speech and somatosensory cortex. This enabled a radical subtotal (two cases) or an apparent total (two cases) excision of the tumour close to somatosensory and speech cortex with no permanent neurological deficit. Use of this technique allows radical excision of intrinsic low and intermediate grade gliomas that would otherwise be considered unexcisable and may lead to an improved survival.