Effects of polycyclic aromatic hydrocarbons on germination and subsequent growth of grasses and legumes in freshly contaminated soil and soil with aged PAHs residues.

The relevance of germination trials for screening plants that may have potential for use in the phytoremediation of PAH contaminated land was evaluated. The germination and subsequent growth of 7 grass and legume species were evaluated in soil spiked with a pure PAH mixture or coal tar and soil from a former coking plant heavily contaminated with aged PAHs. None of these treatments adversely affected germination of the plants. However, apart from Lolium perenne all species exhibited reduced growth in the coking plant soil after 12 weeks growth when compared to the untreated soil. In the coal tar spiked soil 4 out of the 7 species showed reduced growth, as did 3 out of the 7 in the soil spiked with a mixture of 7 PAHs. Therefore, germination studies alone would not predict the success of subsequent growth of the species tested in the ranges of soil PAH levels studied.

The role of endorphins in animal learning and behavior.

The present review examined the influence of endorphins in animal learning and behavior. It was suggested that in learning paradigms involving stress, the stressor elicits the release of endorphins. Given the evidence on endorphin-mediated, stress-induced analgesia, it was further suggested that the stress-induced release of endorphins modulates the aversiveness of the stressor, and as such, affects the learning based on this stressor. A number of learning paradigms, e.g., the conditioned emotional response, preference for signaled shock, conditioned taste aversions, and learned helplessness, were presented in support of this mediation of learning by the endorphins. A possible interaction between the endorphins and adrenocorticotropic hormone was offered as a physiological basis for this mediation.

Organization of projections from olfactory epithelium to olfactory bulb in the frog, Rana pipiens.

One hypothesis for the coding of olfactory quality is that regions of the olfactory epithelium are differentially sensitive to particular odor qualities and that this regional sensitivity is conveyed to the olfactory bulb in a topographic manner by the olfactory nerve. A corollary to this hypothesis is that there is a sufficiently orderly connection between the epithelium and the olfactory bulb to convey this topographical coding. Thus we examined topography in the projection from epithelium to bulb in the frog, which has been the subject of numerous electrophysiological studies but has not yet been examined using modern neuroanatomical techniques. The tracer WGA-HRP was applied to the ventral or to the dorsal olfactory epithelium, or both. Anterograde transport of label to the olfactory bulb was seen after as few as 2 days; label was still present in the bulb as long as 21 days postinjection. In cases where WGA-HRP was applied to the entire epithelium, there was dense anterograde labelling of the ipsilateral olfactory bulb. In addition, a small medial portion of the contralateral bulb was labelled. Injections limited to either the ventral or dorsal epithelium produced patterns of anterograde labelling in the glomerular layer of the olfactory bulb, which varied with the size and location of the injection. With very large injections in either the dorsal or ventral epithelium, label appeared to be evenly distributed in the glomerular layer. With smaller injections in the ventral epithelium, there was heavier labelling in the lateral than in the medial portions of the glomerular layer, although light labelling was found in all regions of the glomerular layer. In contrast, injection sites restricted to the dorsal epithelium produced more anterograde labelling in the medial than lateral portions of the glomerular layer. These patterns extended throughout the dorsal-ventral extent of the bulb. Within the limits of the anterograde tracing technique used, we were unable to detect any systematic relationship between the pattern of labelling in the glomerular layer and the medial-lateral or rostral-caudal location of the injection site in either the ventral or dorsal epithelium. We conclude that in the frog, as in other amphibia, there is only a limited degree of topographic order between the epithelium and the olfactory bulb.

Skin vascular resistance and skin perfusion pressure as predictors of healing of ischemic lesion of the lower limb: influences of diabetes mellitus, hypertension, and age.

An isotope washout technique that requires inexpensive equipment and is well tolerated by patients has been developed to measure skin perfusion pressure (SPP) and skin vascular resistance (SVR). The SPP is a measure of the severity of peripheral vascular disease and the SVR is an indicator of microangiopathy associated with diabetes mellitus and hypertension. This test has been applied to 87 patients who had ischemic lesions of the lower limb. Fourty-four patients had lesions that healed with local treatment while the other 43 required major surgery. The presence of diabetes, hypertension, and old age reduced the likelihood of healing. Similarly if the SPP less than 40 mm Hg, only 18% of patients' lesions healed. If the SPP lay between 40 and 50 mm Hg and the SVR less than 1000 U, 67% of lesions healed. However, if the SPP was between 40 and 50 mm Hg and the SVR greater than 1000 U, no lesions healed. If the SPP greater than 50 mm Hg and SVR less than 1000 U, 83% of lesions healed, where as if the SVR greater than 1000 U, healing occurred in only 23% of lesions. This test can be used to predict the likelihood of healing of ischemic lesions of the lower leg, thus rationalizing their management. The importance of microangiopathy is also demonstrated.

Prospective assessment of incontinence after radical retropubic prostatectomy: objective and subjective analysis.

OBJECTIVES: To assess prospectively-using pad test and questionnaire-the rate and degree of incontinence after radical retropubic prostatectomy, to analyze factors that may predispose individuals to postoperative incontinence, and to assess the impact of incontinence on patient lifestyle. METHODS: Fifty-one consecutive patients were assessed at 3-month intervals for 1 year after radical retropubic prostatectomy. Patients were objectively assessed using a 1-hour pad test and subjectively assessed by questionnaire. Incontinence was graded objectively according to the change in weight of the pad at 1 hour and subjectively by the number of pads used per day. Lifestyle modifications were assessed by questionnaire at 12 months. A number of variable factors were studied to assess risk factors for postoperative incontinence. RESULTS: Continence continued to improve up to 12 months. At 12 months, pad testing revealed 84% of patients were dry, 6% were mildly incontinent. 6% were moderately incontinent, and 4% were severely incontinent. Questionnaire assessment revealed 80% wore no pad, 14% had mild incontinence, 4% had moderate incontinence, and 2% had severe incontinence. Pad testing was not as sensitive as the questionnaire for the detection of minimal incontinence but was more reliable for moderate and severe levels. Patients made lifestyle changes proportional to the level of incontinence. No predisposing factor was identified for the development of incontinence after radical retropubic prostatectomy. CONCLUSIONS: Significant incontinence after radical prostatectomy occurs in as many as 10% of patients. Pad testing provides an inexpensive and simple form of objective assessment in patients with bothersome incontinence and allows documentation of improvement over time.

Assessing odor generalization in the rat: a sensitive technique.

In investigating the ability of the rat to discriminate among urine odors from mice of different genetic strains, we developed a technique for determining the extent of odor generalization. Trained rats performed a discrete trial, go/no-go procedure, touching a bar in the presence of an S+ odor for water reward. Rats easily learned this task and restricted their responding to trials with the S+ stimulus, even though there was no penalty for responding to S-. However, when presented with test stimuli that might be more similar to S+ or S-, some rats responded only to the S+, and not at all to S- or any generalization stimuli. We then created series of stimuli composed of different levels of adulteration of the S+ stimulus with generalization stimuli. With these stimuli, rats produced graded levels of responding, allowing comparisons of similarity among odorant stimuli. This technique can be applied to other types of odorant stimuli, particularly biological compounds of unknown concentration or purity, and should be of use in an operant laboratory studying odorant perception, or odorant characteristics.

The diagnosis of a conductive olfactory loss.

OBJECTIVES/HYPOTHESIS: Two of the most common causes of olfactory loss include upper respiratory infection (URI) and nasal or sinus disease. The etiology of most URI-related losses is thought to be viral and, as yet, there is no available treatment. In contrast, nasal or sinus disease produces an obstructive or conductive loss that often responds dramatically to appropriate therapy. Therefore, the distinction is important but in many cases may be difficult because such patients often present with no other nasal symptoms, and routine physical findings may be nonspecific. The purpose of this report is to characterize those aspects of the history and physical examination that will help to substantiate the diagnosis of a conductive olfactory loss. STUDY DESIGN: A retrospective, nonrandomized study of consecutive patients presenting with a primary complaint of olfactory loss. METHODS: This study reviewed 428 patients seen at a university-based taste and smell clinic from July 1987 through December 1998. Of this total, 60 patients were determined to have a conductive olfactory loss. All patients were referred specifically because of a primary chemosensory complaint. The University of Pennsylvania Smell Identification Test (UPSIT; Sensonics, Inc., Haddon Heights, NJ) was administered in all cases. RESULTS: The most commonly diagnosed etiologies of olfactory loss were head injury (18%), upper respiratory infection (18%), and nasal or sinus disease (14%). Of the 60 patients with a conductive loss, only 30% complained of nasal obstruction, whereas 58% described a history of chronic sinusitis. Only 45% reported that their olfactory loss at times seemed to fluctuate in severity. Anterior rhinoscopy failed to diagnose pathology in 51% of cases, whereas nasal endoscopy missed the diagnosis in 9%. Systemic steroids elicited a temporary reversal of conductive olfactory loss in 83% of patients who received them, offering a useful diagnostic maneuver, whereas topical steroids did so in only 25%. CONCLUSIONS: The etiology for olfactory loss can in many cases be difficult to determine, but it is important to establish prognosis and to predict response to therapy. Diagnosis requires a thorough history, appropriate chemosensory testing, and a physical examination that should include nasal endoscopy. A trial of systemic steroids may serve to verify that the loss is indeed conductive.

Identification of obstructive sleep apnea in patients who snore.

As the field of sleep medicine has evolved, the clinical implications of obstructive sleep apnea (OSA) in snoring patients have become well accepted. Recent advances in surgical therapy for snoring allow otolaryngologists to offer simple outpatient treatment to patients with this problem. However, because the incidence of OSA in snorers seeking medical attention is unknown, the appropriate pretreatment evaluation of these patients is a subject of continued debate. Ninety-four snoring patients were recruited for a study to determine the incidence of OSA in this highly selected population. Subjects answered an extensive sleep questionnaire to determine factors that might suggest a diagnosis of OSA. Level III ambulatory sleep studies were performed on each participant. The incidence of OSA in this group was 72% (42% severe and 30% mild to moderate). Twenty of the subjects with OSA also underwent formal level I sleep studies, and the diagnosis of OSA was confirmed in each instance. Although there was a relationship between body mass index and OSA and certain questions correlated with OSA, the sensitivity and specificity of these data alone or in combination were too low to recommend their use in lieu of a formal sleep study. Given the remarkably high incidence of OSA in this group, which may reflect that seen by otolaryngologists who treat snoring, a sleep study should be performed to diagnose OSA and institute therapy for this condition. Level III ambulatory monitoring devices may be the most cost-effective alternative for evaluating this high-risk population.

Long-term follow-up of olfactory loss secondary to head trauma and upper respiratory tract infection.

OBJECTIVE: To determine the extent to which olfactory function can improve after loss induced by head trauma or a previous upper respiratory tract infection (URI) and the time for this improvement for more effective patient counseling. DESIGN: Patients initially evaluated at the University of Cincinnati (Ohio) Taste and Smell Center were reevaluated for olfactory loss with the University of Pennsylvania (Philadelphia) Smell Identification Test 1 to 5 years after initial testing. Changes in score on this test were used to indicate improvement in sensory function. Subjective information on olfactory ability and olfactory symptoms was also collected. SETTING: University-based tertiary care center. PATIENTS AND OTHER PARTICIPANTS: Forty-one patients with olfactory loss induced by head trauma (20) or previous URI (21). RESULTS: Seven (35%) of 20 patients with head trauma improved on the smell test by 4 points or more. Fourteen of 21 (67%) patients with a previous URI had improved scores of this magnitude or more. A statistically significant correlation was noted between the amounts of improvement and length of follow-up for URI patients. Thirteen of these patients also reported improved olfactory function. CONCLUSION: These findings for patients with head trauma are consistent with other reports of recovery of (or improvement in) olfactory function after trauma-induced loss. For patients with previous URI, these data indicate that improvement in olfactory function occurs, but the improvement may take several years.

Human olfactory biopsy. The influence of age and receptor distribution.

Thirty-six mucosal specimens were obtained with a biopsy instrument from the upper nasal septum of 12 human autopsy cases before the en bloc removal of the entire olfactory area. Examination of these 36 specimens with transmission electron microscopy demonstrated olfactory epithelium in only 17. A significant negative correlation (r = -.728) was noted between the age of the subject and the probability of obtaining olfactory epithelium, supporting the idea that the olfactory mucosa is gradually replaced by respiratory epithelium with aging. Using the en bloc specimens, the distribution of olfactory epithelium was reconstructed from light microscopic examination of silver-stained sections. Multiple patches of respiratory epithelium were observed over the upper portion of the nasal septum and superior turbinates, ie, the presumptive olfactory area. On transmission electron microscopic examination, frequent respiratory metaplasia was also suggested. Within the area of respiratory metaplasia, supporting cell-like and microvillar cell-like structures often were found; these structures may be remnants of olfactory epithelium. The sampling of olfactory tissue with a biopsy procedure is hampered by the irregular and patchy distribution of olfactory epithelium. The invasion of respiratory epithelial patches into the olfactory mucosa seems to be characteristic of the human olfactory epithelium and may increase as a function of age. Thus, conclusions about the structure of the olfactory mucosa in an individual patient must be based on several tissue samples.

Method for the measurement of the diffusion coefficient of benzalkonium chloride.

Biofilm formation on the optical ports of cameras and underwater sensors is the primary cause of their reduced useful deployment time. The use of a transparent hydrogel coating containing the cationic surfactant benzalkonium chloride has been shown to extend the deployment times for up to 12 weeks for these instruments. In order to predict the effective lifetime of these coatings it was necessary to obtain the diffusion coefficient of the benzalkonium chloride used in the coatings. Benzalkonium chloride can have different alkyl chain lengths ranging from C8H17 to C18H37 with chain length greatly affecting its chemical properties. The benzalkonium chloride materials investigated here were mixtures of C12H25 and C14H29 as well as C14H29 on its own. These materials were selected for their proven biofilm resistant qualities. The diaphragm diffusion cell technique was investigated for its applicability to the measurement of diffusion coefficients of molecules with surfactant properties and the ability to form micelles. The method was found to be satisfactory for the cationic surfactant benzalkonium chloride. The average value of the membrane cell integral diffusion coefficient D was 7.78 x 10(-6) cm2 s(-1) at 25 degrees C and there was no significant effect of alkyl chain length on the measured value of D.

Olfactory disturbance in pediatric tracheotomy.

Several studies have described hyposmia after laryngectomy. The most common mechanism invoked is a reduction in nasal airflow, leading to elevated olfactory detection thresholds. Children with nasal obstruction have been shown to also have elevated olfactory detection thresholds linked to reduced nasal airflow. A child with a tracheotomy is in some degree similar to a laryngectomee. These patients will have variable amounts of nasal airflow reduction proportional to the degree of suprastomal obstruction. Our concern was that this alteration in nasal airflow may cause hyposmia. Furthermore, if the olfactory system requires adequate early stimulation for normal development (as is the case with vision and hearing), tracheotomy would be suspected to cause persistent hyposmia even after decannulation. Thus decreased olfactory sensitivity, delayed olfactory experience, or both could interfere with a child's ability to recognize and identify odor stimuli. We studied children aged 4 to 16 years with upper airway obstruction requiring tracheotomy and compared their abilities to identify familiar odorants with those of a large group of normal control children. None of the children had intrinsic mucosal or olfactory pathology. Statistical analysis of the early data shows a significant reduction in olfactory identification scores in the patients with tracheotomies, both by Student's t test and by the Wilcoxon rank sum test. Analysis of covariance confirmed age as an independent prognostic variable for identification ability. We therefore conclude that tracheotomy can reduce a child's ability to identify familiar odorants.

The effects of concurrent responding and reinforcement on behavioral output.

Four birds key pecked on concurrent variable-interval one-minute variable-interval four-minute schedules with a two-second changeover delay. Response rates to the variable-interval one-minute key were then reduced by signaling its reinforcer availability and later by providing its reinforcers independently of responding. Each manipulation increased response rates to the variable-interval four-minute key even though relative reinforcement rates were unchanged. In a final phase, eliminating the variable-interval one-minute key and its schedule produced the highest rates of all to the variable-interval four-minute key. These results show that both reinforcement and response rates to one schedule influence response rates to another schedule. These results join those of Guilkey, Shull, & Brownstein (1975) in failing to replicate Catania (1963). Moreover, they violate the predictions of the equation for simple action (de Villiers & Herrnstein, 1976). In terms of a median-rate measure (reciprocal of the median interresponse time), rates to the variable-interval four-minute key were high when responding was not reduced to the variable-interval one-minute key and were low when it was reduced. This rate difference suggests a process difference between concurrent-schedule procedures that maintain high concurrent response rates versus those that do not. This process difference jeopardizes attempts to integrate single- and concurrent-operant performances within a single formulation.

Stimulus generalization from feeder to response key in the acquisition of autoshaped pecking.

During autoshaping, a 6-second presentation of one stimulus and a variable time 30-second presentation of a second stimulus alternated in appearance on a pigeon key. Grain always was delivered for 3 seconds at the end of the first stimulus interval. In the first experiment, autoshaped pecking of the stimulus preceding grain delivery began much sooner when that stimulus was a black vertical line on a white background and the other stimulus was green than when the opposite stimulus arrangement was used. Because these two stimuli differed in form, hue, brightness, and similarity in hue and brightness to the illumination of the raised feeder, three subsequent experiments examined whether the differential speed of autoshaping in the two groups was due to a feature-positive, feature-negative effect, a preference for brighter over darker stimuli, a simple preference for white over green, or stimulus generalization from the brightness or hue of the illuminated, raised feeder to the stimulus on the key preceding grain delivery. The data from these experiments showed that the first autoshaped key peck was most likely to be made to the stimulus of the same hue as that illuminating the feeder, regardless of whether that stimulus was positively or negatively associated with grain delivery. At least under some conditions, therefore, stimulus-generalization mediated response transfer of pecking grain in the presence of the hue illuminating the feeder to pecking the key illuminated by a similar hue appears to account for the occurrence of autoshaped key pecking.

Office management of taste and smell disorders.

Chemosensory disorders have been receiving increasing clinical attention but remain a difficult diagnostic problem. With the development of several well-standardized testing methods, taste or smell loss can now be verified, and this has added to knowledge concerning the common causes of dysfunction. Diagnosis typically rests upon the history and physical examination, but, except in the case of obstructive nasal and sinus pathologic conditions, therapy usually remains elusive.

Study of PAH dissipation and phytoremediation in soils: comparing freshly spiked with weathered soil from a former coking works.

A comparison was made between the dissipation of polycyclic aromatic hydrocarbons (PAHs) in soil freshly spiked with pure PAHs, soil spiked with a coal tar mixture and a contaminated soil from a former coking works where the PAHs had been present for more than a century. The potential of five selected plant species for phytoremediation was investigated. The levels of all 7 PAHs in chemically amended soil, both planted and unplanted, fell significantly (>80% reduction) over the 12 weeks of the growing trial. In the coal tar treated soils all PAHs were significantly reduced. In both the planted and unplanted soils the 2-3 ringed compounds demonstrated much greater loss (>77%) than the 4-6 ringed (16-39%). The 3-4 ringed compounds demonstrated strong evidence of phytoremediation but not the 5-6 ringed. The coking soil showed limited reduction (7-24%) of all 12 PAHs present. There was little difference in dissipation between the PAHs and little evidence of a phytoremediation effect in coking soil. The results demonstrated that the form in which PAHs were added to soil influenced their susceptibility to dissipation. Therefore, predictions of PAH dissipation from laboratory amended soil do not reflect the true situation in the field.

Spatial and temporal variations in Pb concentrations and isotopic composition in road dust, farmland soil and vegetation in proximity to roads since cessation of use of leaded petrol in the UK.

Results are presented for a study of spatial distributions and temporal trends in concentrations of lead (Pb) from different sources in soil and vegetation of an arable farm in central Scotland in the decade since the use of leaded petrol was terminated. Isotopic analyses revealed that in all of the samples analysed, the Pb conformed to a binary mixture of petrol Pb and Pb from industrial or indigenous geological sources and that locally enhanced levels of petrol Pb were restricted to within 10 m of a motorway and 3 m of a minor road. Overall, the dominant source of Pb was historical emissions from nearby industrial areas. There was no discernible change in concentration or isotopic composition of Pb in surface soil or vegetation over the decade since the ban on the sale of leaded petrol. There was an order of magnitude decrease in Pb concentrations in road dust over the study period, but petrol Pb persisted at up to 43% of the total Pb concentration in 2010. Similar concentrations and spatial distributions of petrol Pb and non petrol Pb in vegetation in both 2001 and 2010, with enhanced concentrations near roads, suggested that redistribution of previously deposited material has operated continuously over that period, maintaining a transfer pathway of Pb into the biosphere. The results for vegetation and soil transects near minor roads provided evidence of a non petrol Pb source associated with roads/traffic, but surface soil samples from the vicinity of a motorway failed to show evidence of such a source.

Martorell's hypertensive ischemic leg ulcers are secondary to an increase in the local vascular resistance.

In 1945 Martorell described ischemic leg ulcers in patients with hypertension and suggested that the ischemic necrosis was secondary to hypertensive arteriolar disease. The aim of the study was to examine the minimum vascular resistance in the skin of patients with these ulcers. Twelve control subjects (median age 52 years), eight patients with peripheral vascular disease (PVD) (median age 73 years), and six patients with hypertensive ulcers (median age 74 years) were studied. The minimum vascular resistance (MVR) and skin perfusion pressure (SPP) were determined by an isotope clearance method. Presence and severity of PVD were assessed by ankle/arm pressure ratios. The ulcer patients had a higher ankle/arm pressure ratio than the PVD group (p = 0.026) but had similar SPP (p = 0.47). When compared with the control group they had a similar pressure ratio (p = 0.09) but lower SPP (p = 0.001). The MVR was higher in the ulcer patients than the control subjects (p = 0.005) and the PVD group (p = 0.01). The study shows that patients with hypertensive ulcers have a high vascular resistance. This increase in resistance may interfere with the compensatory relaxation that normally occurs distal to an arterial narrowing, resulting in poor tissue perfusion and subsequent ulcer development.

Chronic intestinal ischaemia: A report of 3 cases.

Chronic intestinal ischaemia should always be considered in the differential diagnosis of dyspepsia. Three cases are described to illustrate the variable presentation of the condition, its diagnosis and the satisfactory result of surgical reconstruction which may avert the potentially fatal complication of acute mesenteric thrombosis.

Evaluation of an isotope washout technique to measure skin vascular resistance and skin perfusion pressure: influence of age, site and arterial surgery.

A simplified isotope washout technique has been devised to calculate the skin perfusion pressure (SPP) and skin vascular resistance (SVR). This test is simple, requires inexpensive equipment and is well tolerated by patients. SPP and SVR were calculated in 20 patients less than 30 years of age, 13 patients greater than 30 years of age and in 15 patients with peripheral vascular disease (PVD). With increasing age the SPP and SVR were increased. The SPP was similar to the mean arterial pressure in normal individuals but was decreased in patients with PVD. The SPP is a useful indicator of the severity of the PVD. The SPP and SVR were higher in the calf than in the foot. This is probably related to the decrease in pressure in the distal arterial tree. SPP was increased by 110% and skin blood flow by 190% by arterial reconstructive surgery. This test may be of use in assessing the effectiveness of arterial surgery.