Novel pressurized solvent extraction vessels for the analysis of polychlorinated biphenyl congeners in avian whole blood.

Persistent organic pollutants remain a serious threat to many food-chain systems. New pollutants continue to emerge. The present study has created novel extraction vessels which are compatible with readily available commercial instrumentation to validate the analysis of one class of persistent organic pollutants, polychlorinated biphenyls (PCBs), in avian blood. The volumes used can be reasonably sampled without sacrificing individuals, or comprising breeding or migratorial success. The procedure consists of the pressurized solvent extraction (PSE) of analytes in a novel PSE extraction vessel. The new extraction cell contains a 38-cm long, coiled, re-packable, in situ clean-up column. Lipid elimination, using Florisil, occurs within the coiled region of the extraction vessel, eliminating the requirement for post extraction clean-up. For development, 0.2 g samples of chicken whole blood have been used. Extract volumes are reduced from (30 to 10) cm(3), compared to unmodified systems. The new PSE vessel with its integrated clean-up method showed satisfactory performance for the analysis of ten environmentally relevant PCB congeners in chicken whole blood samples with recoveries in the range of (70-130)%. Detection limits using gas chromatography coupled with large volume injection ion-trap mass spectrometry (GC-LVI-ITMS-MS) were in the range of (0.05-0.5) ng g(-1). The relative standard deviations for all congeners investigated were better than 5%. This is the first PSE validation to have been conducted on unaltered whole blood samples.

Audit of suspected chronic intestinal pseudo-obstruction in patients with gynecologic cancer.

PURPOSE: To describe chronic intestinal pseudo-obstruction (IPO) syndromes that occur after radiotherapy or chemotherapy (or both) for gynecologic cancer. METHODS: All 48 patients in the study population had a history of gynecologic cancer, treatment with radiotherapy or chemotherapy (or both), and suspected chronic IPO. The final diagnosis was based on clinical symptoms, radiographic imaging, motility studies, and surgical findings. Treatment was expectant for 27 patients and surgical for 21. RESULTS: In six of the 21 surgical patients, the final diagnosis was mechanical obstruction. In the other 15, it was IPO syndrome: six had an idiopathic dysfunction (ID) and nine had a thick fibrinous coating (FC) on the serosal surface. Intestines of these 15 patients had patent lumens but decreased motility. The ID and FC groups differed in mean age, chemotherapy administration, and mean time from radiotherapy to surgery. Symptoms improved in 67% of FC patients compared with 17% of ID patients. Among patients treated expectantly, symptoms improved in 50% of the ID patients and in 38% of the FC patients. Motility studies were useful for distinguishing ID from FC or mechanical obstruction. CONCLUSION: Clinical history and motility studies may assist in diagnosing IPO syndrome in gynecologic cancer patients treated with radiotherapy or chemotherapy (or both) and in identifying patients who might benefit from surgical intervention.

Should patients with a pre-operative prostate-specific antigen greater than 15 ng/ml be offered radical prostatectomy?

BACKGROUND: Patients with prostate cancer with a pre-operative prostate-specific antigen (PSA) >15 ng/ml who undergo radical retropubic prostatectomy (RRP) generally do not have a good outcome, yet may have organ-confined cancer and should be offered the option of surgery. AIM: To assess the outcome of patients who underwent RRP with a pre-operative PSA >15 ng/ml. METHODS: Thirty-four patients, mean pre-operative PSA: 25.46 ng/ml (15.03-76.6) and mean Gleason score: 6.4 (5-9) were assessed. RESULTS: Two groups were identified. Group I: 41% (14/34) have no biochemical recurrence to mean follow up of 58 months (30-106). Mean PSA: 18.8 ng/ml (15.03-25.84). Mean Gleason score: 6.1 (5-7). Clinical stage: T1c in 80%. No patient had seminal vesicle or lymph node involvement. Group II: 59% (20/34) have biochemical recurrence or died (3) from their disease to mean follow up of 66 months (36-98). Mean PSA: 28.9 ng/ml (15.28-76.6). Mean Gleason score: 6.7 (5-9). Clinical stage: T1c in 25%. Eleven patients had seminal vesicle (8) involvement or positive lymph nodes (3) or both (2). CONCLUSION: RRP seems feasible in patients whose pre-operative PSA is between 15 and 25 ng/ml with stage T1c, Gleason score < or = 7 and negative lymph node frozen section.

An open trial of octreotide long-acting release in the management of short bowel syndrome.

OBJECTIVES: The aim of this study was to assess the effects of the long-acting release (LAR) depot octreotide preparation Sandostatin LAR Depot on stool water and electrolyte losses, fecal fat excretion, and GI transit in patients with short bowel syndrome. METHODS: We performed a 15-wk, prospective, open-label study of intramuscular (i.m.) Sandostatin LAR Depot, 20 mg, at 0, 3, 7, and 11 wk. Balance studies were performed before and at the end of the 15-wk study. Baseline and posttreatment measurements of body weight, stool fat, sodium and potassium, and gastric and small bowel transit of a radiolabeled egg meal were compared by paired analysis. RESULTS: We studied eight patients with short bowel syndrome (five women and three men; mean age 52 yr, range 37-72 yr) who had been TPN dependent for a mean of 11.8 yr (range 1.5-22 yr). The underlying diagnoses were Crohn's disease (n = 6), intestinal ischemia (n = 1), and resection for carcinoid tumor (n = 1). Treatment with Sandostatin LAR Depot significantly increased small bowel transit time (p = 0.03). Changes in body weight, urine volume, stool weight, fecal fat excretion, stool sodium and potassium excretion, or gastric emptying rate were highly variable, and no overall significance was observed. CONCLUSIONS: Sandostatin LAR Depot for 15 wk significantly prolonged small bowel transit time. Body weight and stool parameters in response to Sandostatin LAR Depot treatment needs to be assessed further in multicenter studies assessing dose, frequency of administration, and a larger sample size.

Frequency and site-dependent variations in vibration detection thresholds on the face.

An adaptive psychophysical procedure was used to estimate the vibration detection threshold at seven spatially matched sites on the two sides of the face and at one scalp site. Repeated measurements over six testing sessions were made for stimuli vibrating at 1, 10 and 100 Hz for each of 21 neurologically healthy, young adult females. Approximately 14 stimulus trials were required to obtain each estimate of the threshold amplitude. Thresholds varied as a function of frequency (p < 0.0001), side (p < 0.001) and site (p < 0.0001). Compared to stimulation at 100 Hz at which the estimates were lowest, thresholds were 3.1 times greater at 10 Hz and 5.4 times greater at 1 Hz. Thresholds were lowest on the vermilion and highest on the cheek and chin. The preauricular skin and scalp exhibited an intermediate level of sensitivity. Whereas thresholds were comparable on the two sides of the face for stimulation at 1 Hz, they averaged 1.33 times greater on the right side for stimulation at 10 and 100Hz. Moreover, thresholds obtained during the last two sessions were 16% higher than those obtained during the first two sessions (p < 0.02), suggesting that subjects on average became more conservative in reporting the presence of the stimulus. The sensitivity in discriminating differences in tactile function favors use of the rapidly administered testing procedure in a clinical setting.

The management of ureteric calculi without extracorporeal shock-wave lithotripsy.

BACKGROUND: Extracorporeal shock-wave lithotripsy (ESWL) is a relatively new technological adjunct in the treatment of renal calculi, but availability is limited. AIM: The aim of this study was to assess the outcome of ureteroscopic procedures in a unit without on-site ESWL facility. METHODS: A retrospective study of all cases of ureteric calculi presenting to this hospital during the period 1991 to 1997 was performed. RESULTS: One hundred and thirty five patients with a mean age of 46.8 years were evaluated. Ninety-four (69.5%) had their stone successfully manipulated and/or extracted at ureteroscopy. Using strict criteria, 41 patients (30.5%) had failed ureteroscopies. Fourteen (10.4%) suffered complications related to their ureteroscopy, thirteen had their complications treated conservatively and three (2.3%) needed open procedures. CONCLUSION: Ureteroscopy has a high success rate and low morbidity. We continue to advocate ureteroscopy in the initial management of ureteric calculi.

A letter-recognition task to assess lingual tactile acuity.

PURPOSE: This study evaluated a novel neurosensory test based on letter recognition developed for the assessment of spatial acuity of the tongue. PATIENTS AND METHODS: An up-down tracking procedure was used to estimate the threshold height for the recognition of embossed letters of the alphabet examined by the tongue tip. The 48 stimuli consisted of acrylic strips, one side of which bore a letter (A, I, J, L, O, T, U, or W) of 3, 4, 5, 6, 7, or 8 mm in height. Twenty neurologically normal young adults were tested. RESULTS: Stable estimates of the threshold height were obtained after delivery of only 15 trials. Threshold height averaged 5.1 mm (range, 3.7 to 6.6 mm) and was unaffected by gender (P>.88). Although the letters were identified correctly 54% of the time, on average, the tangibility of individual letters varied from 5% correct (for W) to 82% correct (for T). The letter W was never identified by 16 of 20 subjects; T, O, and U were identified by all subjects. Analysis of errors confirmed that subjects relied on spatial cues to make the discriminations; 58% of the incorrect responses were made to 1 or 2 letters with spatial features similar to those of the stimulus letter. CONCLUSIONS: The threshold height for letter recognition can be obtained easily and rapidly, exhibits low among-subject variability, and reflects the capacity to extract and process spatial information. Letters of similar legibility on the tongue should be used to minimize underestimation of subjects' true acuities.

Survival of home parenteral nutrition-treated patients: 20 years of experience at the Mayo Clinic.

OBJECTIVE: To present the largest single institutional review of demographics, associated primary diseases, and survival of patients receiving home parenteral nutrition (HPN). MATERIAL AND METHODS: We conducted a retrospective review of medical records of all Mayo Clinic patients treated with HPN between 1975 and 1995. The probability of survival was calculated by using Kaplan-Meier analysis. RESULTS: In the 225 study patients requiring HPN (median age, 51 years), the main underlying primary diseases were as follows: inflammatory bowel disease (IBD) (N = 50), nonterminal active cancer (N = 39), ischemic bowel (N = 35), radiation enteritis (N = 32), motility disorder (chronic pseudo-obstruction) (N = 26), and adhesive intestinal obstruction (N = 18). Other conditions included intestinal and pancreatic fistula, refractory sprue, dumping syndrome, and protein-losing enteropathy. The overall probability of 5-year survival during HPN was 60%. The probability of survival at 5 years based on the primary disease was 92% for IBD, 60% for ischemic bowel, 54% for radiation enteritis, 48% for motility disorder, and 38% for cancer. The probability of 5-year survival stratified by age at initiation of HPN was as follows: younger than 40 years, 80%; 40 through 60 years, 62%; and older than 60 years, 30%. Most deaths during therapy with HPN were attributable to the primary disease. Among the 20 patients who died of an HPN-related cause, 11 deaths were from catheter sepsis, 4 from liver failure, 2 from venous thrombosis, and 2 from metabolic abnormalities. CONCLUSION: Survival of HPN-treated patients is best predicted on the basis of the primary disease and the age at initiation of HPN. Patients with IBD and age younger than 40 years have a better 5-year survival in comparison with other groups. Most deaths during treatment with HPN are a result of the primary disease; HPN-related deaths are uncommon.

Nutrition in inflammatory bowel disease.

The nutritional impact of inflammatory bowel disease is notable, both in Crohn's disease and ulcerative colitis. The causes of malnutrition include decreased intake, maldigestion, malabsorption, accelerated nutrient losses, increased requirements, and drug-nutrient interactions. Inflammatory bowel disease causes alterations in body composition and, because of these changes, affects energy expenditure. Various approaches have been most effective in correcting malnutrition, supporting growth, and managing short-bowel syndrome, but the success of primary therapy has been limited.

Evocation and characterization of percepts of apparent motion on the face.

The percepts evoked by sequential stimulation of sites in close spatial proximity (< or = 2.5 cm) on the face were studied. Both method-of-limits and magnitude-estimation procedures were used to identify and characterize alterations in the percepts produced by systematic changes in the temporal and spatial parameters of the sequence. Each site was stimulated by a vertically oriented row of miniature vibrating probes. Apparent motion was consistently perceived when the delay between the onsets of sequentially activated rows (interstimulus onset interval, or ISOI) fell within a relatively narrow range of values, the lower limit of which approximated 5 msec. Both the upper limit and the perceived smoothness and continuity of the motion percepts (goodness of motion) increased with the duration for which each row stimulated the skin over the range evaluated, 15-185 msec. For the successive activation of only two rows, goodness of motion was not influenced by changes in their separation from 0.4 to 2.5 cm. The ISOI values at which magnitude estimates of goodness of motion were highest increased with the duration for which each row stimulated the skin. As such, maximum goodness of motion decreased with increases in the apparent velocity of motion. When the number of sequentially activated rows was increased from two to four or more, the quality of the motion percepts improved. For the successive activation of multiple closely spaced rows, values of ISOI at which numerical estimates of goodness of motion were highest approximated integral fractions of the duration for which each row stimulated the skin. In this situation, the probes rose and fell in a regular, step-locked rhythm to simulate an edge-like or rectangular object moving across the skin. The goodness of motion so attained was relatively independent of the apparent velocity of motion.

Urinary tract fistulas following gynaecological surgery.

Urinary tract fistulas are a relatively uncommon but important complication of gynaecological surgery. Between 1980 and 1995 we identified 17 patients who developed a urinary tract fistula after gynaecological surgery. Seven of the patients had surgery performed for neoplastic disease but none of these patients received adjuvant radiotherapy before the formation of the fistula. There were 12 vesicovaginal fistulas and five ureteric fistulas. Four of the vesicovaginal fistulas were repaired by the vaginal approach and five vesicovaginal fistulas were repaired by the abdominal route. Three vesicovaginal fistulas were treated by catheterisation alone. Two of the 17 patients took medicolegal action. Early recognition and repair of urinary tract fistulas is recommended. Repair of vesicovaginal fistulas by the vaginal approach is advised. The litigious nature of this distressing condition is lessened when early primary closure is successful.

Effect of growth hormone, glutamine, and diet on adaptation in short-bowel syndrome: a randomized, controlled study.

BACKGROUND & AIMS: The effects of parenteral growth hormone, glutamine supplementation, and a high carbohydrate-low fat (HCLF) diet on gut adaptation in short-bowel syndrome are unclear. The aim of this study was to compare effects of this treatment regimen and placebo in patients with short-bowel syndrome. METHODS: A randomized, 6-week, double-blind, placebo-controlled, crossover study in 8 patients with short-bowel syndrome (average small bowel length, 71 cm; mean duration, 12.9 years) was performed. Active treatment was growth hormone (0.14 mg.kg-1.day-1), oral glutamine (0.63 g.kg-1.day-1), and the HCLF diet for 21 days. The weight, basal metabolic rate, nutrient and electrolyte balance, serum insulin-like growth factor I levels, D-xylose absorption, morphology and DNA proliferation of small intestinal mucosa, and gastrointestinal transit were evaluated. Treatments were compared by paired t test. RESULTS: Active treatment transiently increased body weight, significantly but modestly increased the absorption of sodium and potassium, and decreased gastric emptying. The assimilation of macronutrients, stool volumes, and morphometry of small bowel mucosa were not statistically different in the two treatment arms. CONCLUSIONS: Although treatment with growth hormone, glutamine, and HCLF diet for 3 weeks resulted in modest improvements in electrolyte absorption and delayed gastric emptying, there were no improvements in small bowel morphology, stool losses, or macronutrient absorption.

Survival of human pancreatic enzymes during small bowel transit: effect of nutrients, bile acids, and enzymes.

The activity of pancreatic enzymes declines during aboral intestinal transit. We tested the hypothesis that survival of pancreatic enzyme activities during intestinal transit is affected by amounts or concentrations of calories, nutrients, bile acids, or pancreatic enzymes entering the segments of the small intestine. An oroileal tube was placed in 26 healthy humans. The tube had duodenal, jejunal, and ileal infusion ports for nonabsorbable markers and aspiration ports in the distal duodenum, distal jejunum, and distal ileum. Four infusates of different proportions of protein, fat, and carbohydrate were infused continuously into the duodenum at 40, 90, and 160 kcal/h. Of the nutrients infused into the proximal duodenum, 21 +/- 3, 51 +/- 7, and 39 +/- 5% of fat, protein, and carbohydrate, respectively, were delivered to the distal duodenum. During duodenoileal transit, lipase, chymotrypsin, amylase, and trypsin lost 71 +/- 5, 63 +/- 5, 43 +/- 7, and 38 +/- 9% of activity, respectively (P < 0.01 vs. distal duodenum). During duodenojejunal transit, the activity of each enzyme decreased more than 35% (P < 0.01 vs. distal duodenum), and infusion of more calories into the duodenum improved survival of all enzymes except trypsin (P < 0.05). During jejunoileal transit, greater amounts and concentrations of calories and carbohydrate improved survival of only lipolytic activity (P < 0.01, P < 0.05, respectively), and loss of lipolytic activity correlated directly with delivery of bile acids (r = 0.56, P = 0.05) and chymotrypsin (r = 0.80, P = 0.001) to the distal jejunum. We conclude that intraluminal nutrients increase survival of enzyme activities in the proximal intestine. After absorption of nutrients, the action of chymotrypsin and bile acids decrease lipolytic activity more than activity of other enzymes.

Utility of square-wave gratings to assess perioral spatial acuity.

PURPOSE: The usefulness of square-wave gratings to assess perioral spatial resolution acuity was evaluated. MATERIALS AND METHODS: A psychophysical tracking procedure was used to estimate the threshold groove width for discriminating orientation (horizontal or vertical) of square-wave gratings pressed into the skin. Ten positionally matched sites on the two sides of the face of 36 right-handed, healthy young adults were studied. Commercially available gratings provided alternating ridge- and-groove stimuli with element widths from 0.35 to 3.0 mm. RESULTS: Thirty-three of the 36 subjects could discriminate orientation at all six sites on the vermilion (threshold width averaged 1.06 mm for grooves and for ridges). Thresholds were lower on the mid-portion of the lower vermilion than on the mid-portion of the upper vermilion (P < .05). Moreover, thresholds were lower on the right side of the vermilion than on the left side (P < .02). In contrast to the vermilion, only 25 and 30 subjects could discriminate orientation on the left and right hairy upper lip, respectively; and two or fewer subjects, at each of 12 sites on the chin and cheeks. CONCLUSIONS: Clinical use of small square-wave gratings with ridge and groove widths of 3 mm or smaller is limited to the vermilion. Moreover, baseline values are needed for individual patients to minimize false-positive diagnoses of sensory impairment. The size required of coarser gratings to test other perioral sites may preclude their use for evaluation of discrete, suspect skin areas.

Career satisfaction of physical therapy faculty during their pretenure years.

BACKGROUND AND PURPOSE: The purpose of this study was to compile information about and define variables that are influential in the career satisfaction of tenure-track, full-time, physical therapy faculty who have been employed in academia for 5 years or less but who do not yet have tenure. SUBJECTS AND METHODS: An investigator-developed instrument was used to collect the data. The self-report instrument contained 80 items in four categories: demographics, social supports, teaching, and scholarly activity. Questionnaires were sent to junior physical therapy faculty at the 127 physical therapist schools in the United States and Puerto Rico listed by the American Physical Therapy Association in 1993. There were 163 responses to the survey, representing an estimated 85% of the population of junior faculty as defined by this survey. RESULTS: Eighty-three percent of junior faculty surveyed were satisfied with having taken an academic position, despite feelings of loneliness, tenure anxiety, heavy work loads, and the desire for more guidance from colleagues. CONCLUSION AND DISCUSSION: Social and collegial supports such as relationship with senior faculty and experienced colleagues are key elements influencing faculty satisfaction. Information is given that could be utilized by directors and faculty who are planning to guide the professional development of new faculty.

Stimulus-response diversity in local neuronal populations of the cerebral cortex.

In cortex, neighboring 0.05 mm minicolumns have distinctly different receptive fields (RFs). Within minicolumns, neighboring cells have very similar RFs, but differ prominently in their stimulus-evoked temporal behaviors. This is reproduced in a cortical model that has strong inhibition and semi-random lateral connections among cells with similar RFs. Within modeled minicolumns, non-linear dynamics amplify small differences in cells' lateral inputs into large differences in temporal behaviors. Cells' stimulus-evoked behaviors, though complex, are surprisingly orderly, in that (1) time courses of cells' responses are very stimulus-specific and (2) in the presence of a stimulus, activities of some cells fluctuate coherently, and the patterns of coherence are also stimulus-specific. Thus the model, like real cortex, represents stimulus information in the overall strengths and temporal patterns of cells' responses and in patterns of temporal coherence among cells.

Nutrients and cyclical interdigestive pancreatic enzyme secretion in humans.

BACKGROUND AND AIMS: It is hypothesised that nutrients increase pancreatic enzyme secretion by converting cyclical interdigestive secretion to a non-cyclical pattern. This study tested the hypotheses that nutrients do not interrupt cycles and determined the relation of nutrients, calories, and osmotic load to the rate of pancreatic secretion. METHODS: Twenty six healthy persons were intubated with oroduodenal and orogastric tubes. Each had one of four different solutions containing 12 to 36% of calories as protein, 24 to 48% as fat, and 40 to 64% as carbohydrate infused into the duodenum at 40, 90, or 160 kcal/h for 300 minutes. Nine g/l sodium chloride (290 mOsm) was added to 16 infusates; osmolality of the other 10 infusates was 24 to 98 mOsm. Pancreatic enzyme outputs were measured every 15 minutes and peaks of enzyme secretion were identified. RESULTS: The number of enzyme peaks was similar for the different infusates and the proportion of nutrients in the infusates did not affect secretion of individual enzymes. The nadir, but not the peak of the cycles of enzyme outputs correlated with increasing the caloric load (r = 0.55, p < 0.003 for nadir:peak ratio). Increasing osmolality did not affect cycling but reduced (p < 0.001) enzyme output. CONCLUSION: Nutrients entering the duodenum do not abolish cycles of enzyme secretion; instead they modulate cycles by increasing the nadir. Forty and 90 kcal infusions submaximally stimulate pancreatic secretion and might be used in patients with pancreatitis without producing pain; adding sodium chloride to solutions should increase this effect.