The nature of adrenergic mechanisms involved in anaphylatoxin activity in the guinea-pig

1. Evidence is presented to elucidate the nature of the adrenergic mechanisms involved in responses of the guinea-pig to anaphylatoxin (AT).2. Investigation by means of adrenalectomy, adrenergic neurone blockade, alpha- and beta- adrenoceptor blockade and exclusion of autonomic reflexes, revealed that the adrenergic mechanisms provoked included catecholamine release from the adrenal medulla, sympathetic reflex activity, stimulation of adrenergic neurones and alpha- and beta-adrenoceptor activity.3. The cardiovascular effects of AT, mediated by histamine release, were largely attributable to adrenal medullary and adrenergic neuronal mechanisms. These mechanisms also exerted a restraint on the predominantly histamine mediated bronchoconstrictor effect of AT.4. The cardiovascular effects of AT activity, not attributable to histamine release, were also probably associated with catecholamine release. However, the bronchoconstrictor component of this AT activity was not significantly affected by guanethidine, and it would, therefore, appear that neuronal bronchodilator mechanisms did not exert a restraint upon this aspect of AT activity.5. These findings are generally compatible with previous work showing that adrenergic mechanisms operate during AT-induced responses. In contrast to previous reports, however, the adrenergic activity was predominantly associated with the effects of released histamine.

The evaluation of inflammation induced by material implanted subcutaneously in the rat

Inflammation induced by cotton pellets, implanted subcutaneously in the rat, has been compared with that resulting from implantation of pellets impregnated with irritant substances. Time sequences of fluid exudation and granulation tissue formation have been evaluated by differential weighing. Increased irritancy of the pellets resulted in increased exudate volume, and heavier granulation deposition. Contact between granulation tissue and irritant pellets was delayed until the volume of exudate had subsided. Penetration of the pellet was also delayed. Systemic anti-inflammatory effects from granulomata surrounding implanted pellets were related to either the size of the implantation lesion or the degree of irritancy of the implanted material. Evaluation of granulation tissue formation is suggested as a test for irritancy of surgical fabrics.

The possible occurrence of endogenous anti-inflammatory substances in the blood of injured rats

1 Using the carrageenin rat paw oedema test as an assay, an attempt has been made to confirm the presence of anti-inflammatory activity in the blood of rats with a chronic inflammatory lesion induced by a polyester sponge, and to relate such activity to the systemic anti-inflammatory effect exerted in situ by the lesion. In addition, plasma from rats given acetic acid intraperitoneally has been examined for anti-inflammatory properties. 2 The activity of serum obtained from sponge-bearing adrenalectomized Wistar rats did not differ significantly from that obtained from animals without implants. Furthermore, implanted sponges exerted no systemic anti-inflammatory effect. 3 Similar experiments were performed in sponge-bearing adrenalectomized Sprague-Dawley rats, plasma instead of serum being examined for anti-inflammatory activity. The plasma removed from such animals possessed no anti-inflammatory activity, whilst implanted sponges exerted a small, yet significant, systemic inhibitory effect. 4 When the irritancy of sponge implants was augmented with croton oil, more marked systemic anti-inflammatory effects were observed. However, the plasma obtained from rats injured in this manner exerted no anti-inflammatory effect. 5 No anti-inflammatory activity could be detected in plasma samples obtained from rats treated with doses of acetic acid capable of producing pronounced systemic anti-inflammatory effects. 6 It was concluded that the induction of these inflammatory lesions in rats does not appear to lead to a detectable release of endogenous anti-inflammatory substances into the circulation.

Factors influencing the caries experience of a group of children at the ages of 11-12 and 15-16 years: results from an ongoing epidemiological survey

An analysis of factors influencing the caries experience of adolescents in South Wales is presented. Approximately 1000 children were assessed for caries status and oral cleanliness in 1980 when aged 11-12 years and again in 1984 when aged 15-16 years. In addition, on both occasions, the children completed detailed questionnaires on dental health-related topics. When aged 11-12 years, the observed mean DMFT, DMFS and DFS scores of the children were 4.0, 6.7 and 5.5 respectively. The corresponding scores at age 15-16 years were 6.5, 11.8 and 10.2. A preliminary analysis using conventional multiple regression techniques revealed that a number of factors had a significant influence on the caries experience of the children. The significance of the factors depended on the sex of the population subgroup, the age of the children and the particular caries index studied. However, at both ages the factors of most significance were the number of erupted teeth, total mean plaque score and the reported amount of money spent on sweets per week. A further evaluation using analysis of covariance with the number of erupted teeth and surfaces as the covariates confirmed the significant influence of the total mean plaque score and amount of money spent on sweets. In addition, both analyses indicated that toothbrushing frequency and social class had a significant influence on the caries experience of boys.

Pilot study of recombinant interferon alpha-2a for treatment of infants with bronchiolitis induced by respiratory syncytial virus

Eleven children with bronchiolitis induced by respiratory syncytial virus received 10,000 to 70,000 U of recombinant interferon alpha-2a per kg of body weight per day. None developed signs of toxicity, and all but one developed an antiviral state following treatment. Interferon alpha-2a appears to be safe for infants with bronchiolitis. Its efficacy for the treatment of this condition remains to be determined.

Occupational Exposure in Nuclear Medicine and PET

Purpose: With the increasing use of 18F-fluorodeoxyglucose (FDG) positron emission tomography (PET) for scanning in oncology in our center, a radiation dose survey was performed to determine the impact on staff exposure. Conventional nuclear medicine procedures such as gallium scan, bone scans, and sestamibi cardiac scans are used for comparative purposes.Procedure: Patients were measured using a hand-held radiation monitor (Victoreen 450-P) at various distances and times that replicate typical patient contact scenarios in the Diagnostic Imaging Department.Results: We present our findings from the survey and the implications these have on staff radiation exposure. The data suggest that emerging oncologic techniques such as PET, high dose gallium-67, and high dose Tl-201 do not represent a significantly greater occupational radiation hazard than conventional nuclear medicine procedures.

The influence of corticosteroid pretreatment on anaphylactic bronchoconstriction in the guinea-pig

Previous reports that cortisone and related compounds exerted a small degree of protection against antigen-aerosol-induced anaphylactic reactions, have been confirmed. Optimal effects were obtained 16 to 24 h after corticosteroid pretreatment. Marked effects were obtained from the more potent glucocorticoids, particularly water-soluble compounds. Similar pretreatment decreased the severity and modified the form of anaphylactic bronchoconstrictor responses induced by intravenous administration of antigen. In guinea-pigs pretreated also with mepyramine, the corticosteroids suppressed the residual and presumably non-histamine component of the anaphylactic bronchoconstrictions. Anti-anaphylactic potency was correlated with glucocorticoid and anti-inflammatory activity. A suggested mode of action involves a combination of weak anti-histamine activity and inhibition of release of slow reacting substances of anaphylaxis.

Pneumoconiotic effects of welding-fume particles from mild and stainless steel deposited in the lung of the rat

Rats were exposed to single periods of inhalation of fumes generated by arc welding. Two processes were compared: either manual metal arc (MMA) using flux-coated mild steel (MS) electrodes or metal inert-gas (MIG) welding with stainless steel (SS). Widespread but small deposits of fume particles were cleared effectively from alveoli and airways. Peribronchial and subpleural aggregates of particle-laden macrophages remained. More massive and persistent lung-burdens were established by intratracheal administration of suspensions of fume-particles (10 mg and 50 mg, single doses). Initial pneumonitis was attributed to irritant gases or soluble toxic components of particles. MIG-SS particle deposits were more persistent and lesions more severe, inhibition of phagocytosis or clearance and damage to epithelial cells being associated with possible toxic effects in macrophages. Both types of particle caused alveolar epithelial thickening, with proliferation of granular pneumocytes and exudation of lamellar material. Foam cells appeared in alveoli. Long-term effects (80-300 days) involved formation of nodular aggregates of particle-laden macrophages. Giant cells were formed. Nodules containing MIG-SS material were irregular and surrounded by collapsed and thickened epithelium. Soluble chromium or nickel constituents are cited as probable active agents producing effects resembling those of cytotoxic non-fibrogenic dusts, e.g., soluble silicas . MMA-MS particles produced low-grade fibrotic ( collagenised ) changes.

29. F-18 FDG PET for Suspected or Confirmed Regional Recurrence of Colon Cancer. A Prospective Study of Impact and Outcome

Purpose: Survival of patients (pts) undergoing "curative" treatment for colorectal carcinoma remains poor. Retrospective studies suggest that F-18 FDG PET is more accurate than CT for restaging suspected recurrent disease and favourably impacts management. The aim of this study was to confirm this by prospective analysis.Patient Population and Methods: 102 consecutive patients for whom the referring clinicians had prospectively committed to a treatment plan based on conventional staging investigations and who then underwent F-18 FDG PET scanning were evaluated for management change and outcome. The accuracy of PET results was assessed by surgical findings or clinical follow-up.Results: Overall PET changed management in 66/102 (65%) pts including14 pts changed from observation to active treatment after PET localized disease and 6 pts planned for local therapy to observation after negative PET. Planned surgery was cancelled in 28 pts whereas surgery was initiated in 11 pts. Radiotherapy was prevented in 5 pts, initiated in 11 and the radiation field altered in 5 others. The accuracy of the PET results could be assessed in 63/66 (95%) pts in whom management was changed. Relapse was confirmed in 50/51 pts with a positive PET but disease extent was underestimated in 4 cases. False negative PET results were confirmed in 5 cases.Conclusion: FDG PET has a high and appropriate impact on patient management in patients with suspected recurrent disease. PET can miss small volume disease but the major benefit of PET is to prevent futile attempts at local salvage therapies.

An investigation of the experimental induction of hypersensitivity in the guinea pig by material containing chromium, nickel and cobalt from arc welding fumes

Sensitization of guinea pigs by chromium, cobalt and nickel was compared by four methods. The most effective was the maximization test of Magnusson and Kligman. Sensitizing properties of particles from fumes of either manual metal arc (MMA) or metal inert gas welding were demonstrated. Potent sensitization was attributed to chromium.

An approach to ventricular efficiency by use of carbon 11-labeled acetate and positron emission tomography

BACKGROUND

Positron emission tomography-derived 11C-labeled acetate kinetics have been shown to reflect myocardial oxidative metabolism. The objective of the study was to use this metabolic imaging technique in combination with an evaluation of left ventricular work as an index of ventricular mechanical efficiency.

METHODS AND RESULTS

The effects of ventricular ejection fraction and loading on this index were studied quantitatively in a canine experimental model. There was a curvilinear relationship between efficiency and the end-diastolic volume per unit mass (r = 0.84), which appeared to integrate the main determinants of left ventricular mechanical performance successfully and allowed the detection of a decreased ventricular efficiency in acute experimental heart failure.

CONCLUSIONS

This approach appears to have the potential to assess the energetic working point of the ventricle in clinical heart disease and follow the effects of therapy. The data demonstrate the feasibility of an estimate of ventricular efficiency that relies on noninvasive data-acquisition techniques.

The expression of MHC class II (Ia) antigens on mouse keratinocytes following epicutaneous application of contact sensitizers and irritants

The expression of MHC class II (Ia) antigens on mouse keratinocytes was studied following both the induction and elicitation of contact sensitivity, and after primary irritant reactions. IA+ and IE+ keratinocytes were detected, using an indirect immunofluorescence assay on epidermal sheets, only after the induction and elicitation of contact sensitivity with the sensitizers oxazalone, picryl chloride and 2,4-dinitrochlorobenzene but not with formaldehyde. Ia+ keratinocytes were not detected after epicutaneous application of the non-sensitizing irritants croton oil, SDS and anthralin, or following attempted sensitization of nude mice, suggesting that the expression of Ia antigen on keratinocytes during contact sensitivity reactions is T-cell mediated. Because Ia antigen expression on keratinocytes could be detected only several days after induction or elicitation of contact sensitivity, and contact sensitization could also be demonstrated to occur independently of aberrant Ia expression, Ia+ keratinocytes cannot be involved in the initiation of these reactions. However, they might be important in exerting an immunomodulatory influence during the later stages of the responses to certain sensitizers.

An international survey on hybrid imaging: do technology advances preempt our training and education efforts?

BACKGROUND

Hybrid PET/CT and PET/MRI are increasingly important technologies in the evaluation of malignancy and require cooperation between radiologists and specialists in molecular imaging. The aim of our study was to probe the mindsets of radiological and nuclear medicine professionals in regard to current hybrid imaging practice and to assess relevant training aspirations and perceived shortfalls, particularly amongst young professionals. In this context, we initiated an international survey on "Hybrid Imaging Training".

METHODS

An online survey was prepared on-line and launched on October-2, 2016. It was composed of 17 multiple-choice and open questions regarding the professional background, a perspective on hybrid imaging training efforts and lessons to be learned from disparate craft groups. The survey ran for 2 weeks. We report total responses per category and individual free-text responses.

RESULTS

In total, 248 responses were collected with a mean age of all responders of (41 ± 11) y. Overall, 36% were within the target age range of (20-35) y. Across all responders, the majority (72%) commented on there being too few hybrid imaging experts in their country, whereas only 1% said that there were too many. Three quarters of the responders were in favour of a curriculum allowing sub-specialisation in hybrid imaging. With respect to reporting of hybrid imaging, confidence increased with age. The average rating across all responders on the level of cooperation among the two specialties suggested a low overall level of satisfaction. However, the survey feedback indicated the local (on-site) cooperation being somewhat better than the perceived cooperation between the relevant associations on a European level.

CONCLUSION

We consider these results to represent an appropriate cross-section of professional opinions of imaging experts across different demographic and hierarchical levels. Collectively they provide evidence supporting a need to address current shortfalls in developing hybrid imaging expertise through national educational plans, and, thus, contribute to helping improve patient care.

One-day fluorescent-antibody procedure for detecting salmonellae in frozen and dried foods

The indirect fluorescent-antibody technique was used to examine 422 food samples for the presence of salmonellae. A cultural phase involving a 16-hr preenrichment in buffered nutrient broth-milk medium followed by a 4- to 5-hr subculture into fresh medium of the same composition was evaluated. This procedure yielded a sufficient population of salmonellae so that no false-negative results were obtained. Of the 31 false-positives obtained, 12 samples yielded positive cultural results upon extensive subculture of the original enrichment broths. Yeast cells and both vegetative and spore forms of bacilli were observed to fluoresce when stained with anti-Salmonella serum. Efforts to ascertain the cause of these cross-reactions and several alternate explanations are discussed.

Increased myofibroblast contractile sensitivity in paraquat pretreated rat lung tissue

In numerous tissues, contractility to certain characteristic agents is associated with cells other than muscle, e.g. actin-containing so-called myofibroblasts. Such cells are present in pulmonary interstitium of several mammalian species but their contractility has only been demonstrated from the proliferation of myofibroblasts in fibrotic lung tissues. This study has been done to evaluate such responses in normal tissues in contrast with fibrotic lungs and it was necessary to take account also of smooth muscle reactivity. Distinctive agonists: mepyramine and sodium tungstate characterised myofibroblast mediated contractility, in contrast with acetylcholine and barium chloride as specific smooth muscle stimulants. Histology and immunohistochemistry were used to evaluate the pharmacological results more precisely.

Seasonal pathogen removal by alternative on-site wastewater treatment systems

Subsurface-flow constructed wetlands, sand filters, and peat filters near Duluth, Minnesota, were studied to determine their seasonal performance for removing pathogens from wastewater. Influent was a high-strength septic tank effluent (mean values of 5-day biochemical oxygen demand, total nitrogen, and total phosphorus were 294, 96, and 15 mg/L, respectively) at the Natural Resources Research Institute's alternative treatment system test facility in northern Minnesota. Each treatment system was inoculated with cultures of Salmonella choleraesuis (serotype typhimurium) for 5 to 7 consecutive days in summer and winter during 1998 to 1999. After the seeding, outflow samples were taken until Salmonella counts were sustained at background levels. The removal of Salmonella was calculated for each system, although the exact removal mechanisms were not determined. During the summer, the wetlands removed 99.6 to 99.999 4% (2.4 to 5.3 log10 reduction) of the culturable Salmonella. The sand filters demonstrated a greater than 7 log10 removal of Salmonella cells, whereas the peat filters were responsible for a greater than 8 log10 loss of cells. Fewer Salomonella cells were removed by all of these systems during the winter, although the pattern of removal was similar to their summer operation. During the winter, the wetlands and sand filters removed greater than 1 log10 of culturable cells, but the peat filters were responsible for a greater than 5 log10 loss of cells. Fecal coliform removal patterns reflected those for Salmonella by treatment systems for summer and winter periods. Based on Salmonella and fecal coliform removal, the peat filters operated most effectively followed by the sand filters and the constructed wetlands.

Phase II trial evaluating the feasibility of interdigitating folfox with chemoradiotherapy in locally advanced and metastatic rectal cancer

BACKGROUND

Patients (pts) with metastatic rectal cancer and symptomatic primary, require local and systemic control. Chemotherapy used during chemoradiotherapy (CRT) is adequate for radiosensitisation, but suboptimal for systemic control. The aim of this phase II study was to assess tolerability, local/systemic benefits, of a novel regimen delivering interdigitating intensive chemotherapy with radical CRT.

METHODS

Eligible pts had untreated synchronous symptomatic primary/metastatic rectal cancer. A total of 12 weeks of treatment with split-course pelvic CRT (total 50.4 Gy with concurrent oxaliplatin and 5-FU infusion) alternating with FOLFOX chemotherapy. All pts staged with CT, MRI and FDG-PET pre and post treatment.

RESULTS

Twenty-six pts were treated. Rectal primary MRI stage: T3 81% and T4 15%. Liver metastases in 81%. Twenty-four pts (92%) completed the 12-week regimen. All patients received planned RT dose, and for both agents over 88% of patients achieved a relative dose intensity of >75%. Grade 3 toxicities: neutropenia 23%, diarrhoea 15%, and radiation skin reaction 12%. Grade 4 toxicity: neutropenia 15%. FDG-PET metabolic response rate for rectal primary 96%, and for metastatic disease 60%.

CONCLUSIONS

Delivery of interdigitating chemotherapy with radical CRT was feasible to treat both primary and metastatic rectal cancer. High completion and response rates were encouraging.