Risk of dysplasia in the columnar cuff after stapled restorative proctocolectomy

BACKGROUND

Stapled restorative proctocolectomy (SRP) for ulcerative colitis retains a 'cuff' of columnar epithelium, which carries a risk of undergoing malignant change. The risk of neoplastic transformation was studied in a series of patients who underwent SRP for ulcerative colitis.

METHODS

One hundred and thirty-five patients who underwent SRP for ulcerative colitis between 1988 and 1998 were followed up by cuff surveillance biopsy. The median follow-up was 56 (range 12-145) months and the median time since diagnosis of ulcerative colitis was 8.8 (range 2-32) years.

RESULTS

The cuff biopsies showed no dysplasia or carcinoma. The accuracy of obtaining cuff mucosa in the biopsy was 65 per cent. Chronic inflammation was present in 94 per cent of cuff biopsies.

CONCLUSION

This study shows no evidence of either dysplasia or carcinoma in the columnar cuff mucosa, up to 12 years after pouch formation. This suggests that cuff surveillance in the first decade after SRP, in the absence of dysplasia or carcinoma in the original colectomy specimen, may be unnecessary. Regular cuff surveillance biopsies after SRP should continue for patients with high-grade dysplasia or carcinoma in the original resection specimen.

The vestibulo-ocular reflex and velocity storage in spinocerebellar ataxia 8

The autosomal dominant spinocerebellar ataxias (SCAs) are a group of neurodegenerative diseases characterized by progressive instability of posture and gait, incoordination, ocular motor dysfunction, and dysarthria due to degeneration of cerebellar and brainstem neurons. Among the more than 20 genetically distinct subtypes, SCA8 is one of several wherein clinical observations indicate that cerebellar dysfunction is primary, and there is little evidence for other CNS involvement. The aim of the present work was to study the decay of the horizontal vestibulo-ocular reflex (VOR) after a short period of constant acceleration to understand the pathophysiology of the VOR due to cerebellar Purkinje cell degeneration in SCA8. The VOR was recorded in patients with genetically defined SCA8 during rotation in the dark. Moderate to severely affected patients had a qualitatively intact VOR, but there were quantitative differences in the gain and dynamics compared to normal controls. During angular velocity ramp rotations, there was a reversal in the direction of the VOR that was more pronounced in SCA8 compared to controls. Modeling studies indicate that there are significant changes in the velocity storage network, including abnormal feedback of an eye position signal into the network that contributes to this reversal. These and other results will help to identify features that are diagnostic for SCA subtypes and provide new information about selective vulnerability of neurons controlling vestibular reflexes.

System for robotically assisted percutaneous procedures with computed tomography guidance

We present the prototype of an image-guided robotic system for accurate and consistent placement of percutaneous needles in soft-tissue targets under CT guidance inside the gantry of a CT scanner. The couch-mounted system consists of a seven-degrees-of-freedom passive mounting arm, a remote center-of-motion robot, and a motorized needle-insertion device. Single-image-based coregistration of the robot and image space is achieved by stereotactic localization using a miniature version of the BRW head frame built into the radiolucent needle driver. The surgeon plans and controls the intervention in the scanner room on a desktop computer that receives DICOM images from the scanner. The system does not need calibration, employs pure image-based registration, and does not utilize any vendor-specific hardware or software features. In the open air, where there is no needle-tissue interaction, we systematically achieved an accuracy better than 1 mm in hitting targets at 5-8 cm from the fulcrum point. In the phantom, the orientation accuracy was 0.6 degrees, and the distance between the needle tip and the target was 1.04 mm. Experiments indicated that this robotic system is suitable for a variety of percutaneous clinical applications.

Transtympanic tetrodotoxin alters the VOR and Fos labeling in the vestibular complex

The sodium channel blocker tetrodotoxin (TTX) is an effective tool for blockade of action potentials. Unilateral transtympanic administration of 3 mM TTX produced behavioral symptoms similar to those following unilateral peripheral vestibular ablation. Complete resolution of visible symptoms occurred between 48 and 72 h post-TTX. Eye-coil recordings indicated a spontaneous nystagmus and a decrease in the VOR in TTX-treated animals. Neuronal activity in the central vestibular complex (VC), as monitored with Fos immunocytochemistry, revealed an asymmetric pattern of Fos labeling in the medial, inferior and superior vestibular nuclei and the prepositus hypoglossal nucleus. Although the spatio-temporal pattern of Fos labeling was consistent and reproducible at each time-point, changes were noted among time-points. Transient blockade with TTX may be useful for studying the central vestibular response to recurrent or episodic vestibular disruption in the intact system.

Strategy for the surgical management of patients with idiopathic megarectum and megacolon

BACKGROUND

Several surgical procedures have been used to treat idiopathic megabowel. A structured approach to the surgical management of megarectum/colon is reported.

METHODS

Twenty-eight consecutive patients with megabowel referred for surgery were reviewed. All patients had conservative treatment for 6 months. Those failing to improve underwent full-thickness biopsy of the anorectal junction, anorectal physiology studies, colonic transit studies and evacuation proctography. Surgery involved excision of the abnormal large bowel and formation of an anastomosis (coloanal or ileoanal) using 'normal' bowel identified either by a defunctioning stoma or colonic motility studies.

RESULTS

Eight patients responded to conservative management. Two patients were lost to follow-up and one died from unrelated causes. Two of the 17 patients who underwent full-thickness biopsy were cured by the procedure. Anorectal physiology, colonic transit and evacuation studies did not aid selection of the surgical procedure performed in 15 patients: proctectomy and coloanal anastomosis (six), restorative proctocolectomy (three), panproctocolectomy (one) and defunctioning stoma (five). At a median follow-up of 3.6 years, 13 of 15 evaluable patients had a satisfactory outcome.

CONCLUSION

Approximately 40 per cent of patients with megabowel referred for surgery responded to conservative treatment. The remaining patients may be treated successfully by surgery. The use of either a 'diagnostic' defunctioning stoma or colonic motility studies may aid in the choice of surgical procedure.

Factors that predict complications after construction of a stoma: a retrospective study

OBJECTIVE

To find out our incidence of complications of stoma surgery and identify variables that predict outcome.

DESIGN

Retrospective study.

SETTING

Teaching hospital, Scotland.

SUBJECTS

All 121 patients who had 126 stomas constructed during 1996.

INTERVENTIONS

Follow up until the end of 1999.

MAIN OUTCOME MEASURES

Morbidity and mortality.

RESULTS

There were 64 men and 57 women, median age 58 years, range 16-83. Forty-three stomas were constructed for malignancy (34%). Forty-two stomas were raised during emergency operations (33%). Colorectal surgeons created 96 stomas (76%). Sixty-one of 92 potentially reversible stomas were closed (66%). Two patients died (2%) perioperatively. Overall stoma-related morbidity was 68% (n = 85). The rate of major stoma-related complications was 26% (n = 33). Nine major complications resulted in a reoperation rate of 7%. On univariate analysis, age, American Society of Anesthesiologists (ASA) grade, and surgeon's speciality were significant predictive variables of major stomal complications (p < or = 0.002, 0.02, and 0.05 respectively). Multivariate analysis showed that the age of the patient was the only factor that independently influenced the outcome of stoma surgery (p < or = 0.001).

CONCLUSIONS

Optimising the perioperative health status of the patients, particularly the elderly, may reduce morbidity. The results also support specialist surgical care of patients undergoing stomal surgery.

The relationship of pudendal nerve terminal motor latency to squeeze pressure in patients with idiopathic fecal incontinence

PURPOSE

With the advent of transanal ultrasonography it has been possible to identify those incontinent patients without sphincter defects. The majority of these patients are now thought to have neurogenic fecal incontinence secondary to pudendal neuropathy. They have been found to have reduced anal sphincter pressures and increased pudendal nerve terminal motor latencies. The aim of this study was to determine whether in those incontinent patients who do not have a sphincter defect, prolonged pudendal nerve terminal motor latency correlates with anal manometry, in particular maximum squeeze pressure.

METHODS

Sixty-six incontinent patients were studied with transanal ultrasonography, anorectal manometry, and pudendal nerve terminal motor latency. Twenty-seven continent controls had anorectal manometry and pudendal nerve terminal motor latency measured.

RESULTS

Maximum resting pressure and maximum squeeze pressure were significantly lower in the group of incontinent patients with bilateral prolonged pudendal nerve terminal motor latency (median maximum resting pressure = 26.5 mmHg; median maximum squeeze pressure = 60 mmHg) when compared with incontinent patients with normal bilateral pudendal nerve terminal motor latencies (median maximum resting pressure = 46 mmHg; median maximum squeeze pressure = 79 mmHg; maximum resting pressure P = 0.004; and maximum squeeze pressure P = 0.04). In incontinent patients with no sphincter defects no correlation between pudendal nerve terminal motor latency and maximum squeeze pressure was found (r = -0.109, P = 0.48) and maximum squeeze pressure did not correlate with bilateral or unilateral prolonged pudendal nerve terminal motor latency (r = -0.148, P = 0.56 and r = 0.355, P = 0.19 respectively).

CONCLUSIONS

In patients with idiopathic fecal incontinence damage to the pelvic floor is more complex than damage to the pudendal nerve alone. Although increased pudendal nerve terminal motor latency may indicate that neuropathy is present, in patients with neuropathic fecal incontinence, pudendal nerve terminal motor latency does not correlate with maximum squeeze pressure. Normal pudendal nerve terminal motor latency does not exclude weakness of the pelvic floor.

Coordination of a step with a reach

Although natural reaching behavior can easily include forward body movement, most laboratory studies of reaching have constrained the body to be stationary. Recently, however, it has been shown that normal subjects exhibit a different pattern of errors when attempting to pinpoint remembered target locations, depending on whether or not the reach includes a step. In the study of Flanders et al., these errors appeared to be due to the strategy of eye/head/hand coordination which normally comes into play when the body is moving toward the target. Since the spatial positioning of the head was found to partially explain the errors in hand placement, the present study examined the movements of patients with bilateral vestibular deficits in order to further analyze the whole-body coordination. Somewhat surprisingly, the patients exhibited the same pattern of head movement and the same errors in hand placement as did the control subjects. Nevertheless, the patients' movements clearly exhibited evidence for an abnormal decomposition of elbow extension and trunk rotation. Furthermore the patients' (spatial) hand paths were significantly more curved than those of control subjects and, only in the patients, paths to remembered targets were significantly more curved than paths to visible targets. Thus for movements to remembered targets, the patients tended to move the hand to the same incorrect spatial positions as control subjects but spatiotemporal aspects of the arm and body movement differed. The results are consistent with the idea that vestibular patients are overly dependent upon visual cues, and support the hypothesis that this stepping and reaching behavior is largely dependent upon a visual reference signal.

Graphical human insulin time-activity profiles using standardized definitions

The purpose of this study was to (1) develop consistent definitions to report time-activity profiles of insulin formulations, (2) determine human insulin time-activity profiles based on all available pharmacokinetic studies of biosynthetic human insulin rDNA(E. coli) (Humulin), and (3) create graphs that accurately and usefully represent human insulin time-activity profiles (TAPs). Standard definitions of onset, peak, duration, and time of 50% maximal activity were developed for human insulin. Results from all pharmacokinetic and pharmacodynamic studies available on human insulin from searches of both published literature and unpublished work were analyzed by these standard methods. Data obtained using these definitions were used to construct diagrams of the time-activity relationships for each formulation. Sixty-three insulin tests utilizing a variety of methodologies and data analysis techniques were located. Time-activity curves generated by application of standardized definitions varied depending on methodology, and on whether glucose, insulin and/or glucose infusion rates were used as the measure of insulin activity. A method of standard analysis is required for evaluating insulin pharmacokinetic studies due to the wide variation in design of these studies. Graphic representation of ranges obtained by standard analysis of onset, peak, duration, and 50% maximal activity increase the information transmitted when compared to currently used tables of time-activity data. The time of 50% maximal activity during increasing and decreasing phases may be a better marker of clinically significant activity than the classically defined parameters of onset and duration.

Impact of insulin lispro on HbA1c values in insulin pump users

AIM

To compare the therapeutic efficacy of the short-acting insulin analogue insulin lispro (Humalog) with that of buffered regular human insulin (Velosulin) in patients on insulin pump therapy.

PATIENTS AND METHODS

Sixty-two (45 women and 17 men) young patients with type 1 diabetes using insulin pump therapy were compared while using buffered regular human insulin for a mean +/- s.e.m. of 20.1+/-1.2 months or insulin lispro for a mean +/- s.e.m. of 19.7+/-0.5 months. The initial mean +/- s.e.m. age and duration of diabetes were 29.1+/-0.9 and 17.7+/-0.9 years, respectively. The mean HbA1c values, basal insulin dosages, premeal insulin dosages and number of low blood sugars were recorded during treatment with both insulins.

RESULTS

Mean +/- s.e.m. HbA1c values were significantly lower (p < 0.001; paired Wilcoxon t-test) during insulin lispro treatment (7.4+/-0.1%) as compared to treatment with buffered regular human insulin (7.9+/-0.1%). Total units of insulin (mean +/- s.e.m.)/kg/day was significantly (p = 0.03) lower (0.61+/-0.02) during the insulin lispro treatment period as compared to the buffered regular human insulin treated period (0.65+/-0.03). Total mean +/- s.e.m. (U/kg/day) of basal insulin administered per day was higher when patients received insulin lispro treatment (0.44+/-0.02 vs. 0.42+/-0.01 for buffered regular human insulin treated period; p = 0.002). The premeal insulin boluses (mean +/- s.e.m.) for the two treatment groups were significantly different with less insulin required for the insulin lispro treatment period for all three meals (p < 0.001, t-test). The number of mild/moderate and severe hypoglycaemic episodes were similar in the two groups.

CONCLUSION

We conclude that use of insulin lispro in pump therapy significantly lowers HbA1c values in comparison to therapy with buffered regular human insulin insulin without increasing hypoglycaemic episodes.

Mental maze solving

We sought to determine how a visual maze is mentally solved. Human subjects (N = 13) viewed mazes with orthogonal, unbranched paths; each subject solved 200-600 mazes in any specific experiment below. There were four to six openings at the perimeter of the maze, of which four were labeled: one was the entry point and the remainder were potential exits marked by Arabic numerals. Starting at the entry point, in some mazes the path exited, whereas in others it terminated within the maze. Subjects were required to type the number corresponding to the true exit (if the path exited) or type zero (if the path did not exit). In all cases, the only required hand movement was a key press, and thus the hand never physically traveled through the maze. Response times (RT) were recorded and analyzed using a multiple linear regression model. RT increased as a function of key parameters of the maze, namely the length of the main path, the number of turns in the path, the direct distance from entry to termination, and the presence of an exit. The dependence of RT on the number of turns was present even when the path length was fixed in a separate experiment (N = 10 subjects). In a different experiment, subjects solved large and small mazes (N = 3 subjects). The former was the same as the latter but was scaled up by 1.77 times. Thus both kinds of mazes contained the same number of squares but each square subtended 1.77 degrees of visual angle (DVA) in the large maze, as compared to 1 DVA in the small one. We found that the average RT was practically the same in both cases. A multiple regression analysis revealed that the processing coefficients related to maze distance (i.e., path length and direct distance) were reduced by approximately one-half when solving large mazes, as compared to solving small mazes. This means that the efficiency in processing distance-related information almost doubled for scaled-up mazes. In contrast, the processing coefficients for number of turns and exit status were practically the same in the two cases. Finally, the eye movements of three subjects were recorded during maze solution. They consisted of sequences of saccades and fixations. The number of fixations in a trial increased as a linear function of the path length and number of turns. With respect to the fixations themselves, eyes tended to fixate on the main path and to follow it along its course, such that fixations occurring later in time were positioned at progressively longer distances from the entry point. Furthermore, the time the eyes spent at each fixation point increased as a linear function of the length and number of turns in the path segment between the current and the upcoming fixation points. These findings suggest that the maze segment from the current fixation spot to the next is being processed during the fixation time (FT), and that a significant aspect of this processing relates to the length and turns in that segment. We interpreted these relations to mean that the maze was mentally traversed. We then estimated the distance and endpoint of the path mentally traversed within a specific FT; we also hypothesized that the next portion of the main path would be traversed during the ensuing FT, and so on for the whole path. A prediction of this hypothesis is that the upcoming saccade would land the eyes at or near the locus on the path where the mental traversing ended, so that "the eyes would pick up where the mental traversal left off." In this way, a portion of the path would be traversed during a fixation and successive such portions would be strung together closely along the main path to complete the processing of the whole path. We tested this prediction by analyzing the relations between the path distance of mental traverse and the distance along the path between the current and the next fixation spot. (ABSTRACT TRUNCATED)

Similarity in the response of smooth pursuit and manual tracking to a change in the direction of target motion

Subjects were asked to track, with their eyes or their hand, the movement of a target that maintained a constant speed and made a single, abrupt change in direction. The tracking speed and direction of motion after the step change in target direction were compared for the eyes and the hand. After removal of the saccades from the eye movement records, it was found that in both cases, there was a slow rotation from the initial direction to the new direction. For the eyes and the hand, it was found that this change in direction of movement occurred at a similar rate that was proportional to the magnitude of the abrupt change in target direction. This was further described by comparing the direction of pursuit tracking with the response of a second-order system to a step input. In addition, it was found that the speed of manual and pursuit tracking was modulated in a similar manner, with a reduction in tracking speed occurring before the change in tracking direction. This reduction in speed following the change in the direction of target motion was very similar for the hand and the eye, despite the large difference in the inertias of the two systems. Taken together, these data suggest that the neural mechanisms for smooth pursuit and manual tracking have common functional elements and that musculoskeletal dynamics do not appear to be a rate-limiting factor.

Focal hepatic ablation using interstitial photon radiation energy

BACKGROUND

Intratumoral ablative therapy is being used increasingly for the treatment of primary and secondary hepatic malignancies. The interstitial point-source photon radiosurgery system (PRS) is a novel ablative technique that uses radiation therapy similar in dosimetry to interstitial brachytherapy.

STUDY DESIGN

To determine the feasibility, toxicity, and local tissue destructive capabilities of the PRS in the liver, preliminary studies in a nontumor-bearing canine model were examined. A 6-month survival study was conducted. Each animal received three radiation treatments, in the right, central, and left hepatic regions. Three low-dose treatments were delivered to each of six animals (group A), generating a 2.0-cm-diameter radiated sphere with a dose of 20 Gy at the lesion edge. Three high-dose treatments were delivered to each of six animals (group B), generating a 3.0-cm-diameter radiated sphere with 20 Gy at the lesion edge.

RESULTS

The treatment reproducibly generated sharply demarcated hepatic ablative lesions proportional to the administered dose. Mean lesion diameter at 1 month was 1.6+/-0.2 cm in group A and 3.4+/-1.0 cm in group B. Lesion size was independent of intrahepatic location, including near vascular structures. PRS therapy, when applied to portal structures, resulted in hilar damage. Hilar damage appeared to be associated with arteriolar thrombosis and bile duct injury. Treatment of regions adjacent to large hepatic veins and the IVC was not associated with vessel thrombosis or stricture.

CONCLUSIONS

PRS ablation is a generally well-tolerated method that results in consistent, well-demarcated, symmetric lesions of complete necrosis with minimal adjacent parenchymal injury. Application of such an approach for the treatment of liver tumors is promising.

Respiratory toxicity of fabric softener emissions

To determine whether there is any biological basis for complaints that fabric softener emissions can cause acute adverse effects in certain individuals, screening tests were performed in which groups of mice were exposed to the emissions of 5 commercial fabric softener products (antistatic pads used in laundry dryers) for 90 min. Pneumotachographs and a computerized version of ASTM test method E-981 were used to measure acute changes in several respiratory cycle parameters, especially the pause after inspiration, the pause after expiration, and the midexpiratory airflow velocity. From these changes, sensory irritation (SI), pulmonary irritation (PI), and airflow limitation (AFL) of differing intensities were measured with each of the five brands tested. At the peak effect, SI ranged from 21 to 58% of the breaths, PI ranged from 4 to 23% of the breaths, and AFL ranged from 6 to 32% of the breaths. After three exposures, histopathology revealed mild inflammation of interalveolar septae of the lungs. Gas chromatography/ mass spectroscopy (GC/MS) analysis of the emissions of one pad identified several known irritants (isopropylbenzene, styrene, trimethylbenzene, phenol, and thymol). Laundry that had been dried with one the fabric softener pads emitted sufficient chemicals to elicit SI in 49% of breaths at the peak effect Placing one fabric softener pad in a small room overnight resulted in an atmosphere that caused marked SI (61% of breaths). These results demonstrate that some commercial fabric softeners emit mixtures of chemicals that can cause SI, PI, and reduce midexpiratory airflow velocity in normal mice. The results provide a toxicological basis to explain some of the human complaints of adverse reactions to fabric softener emissions.

Feasibility of ablating normal renal parenchyma by interstitial photon radiation energy: study in a canine model

BACKGROUND AND PURPOSE

A miniature photon radiosurgery system (PRS) has been described as an alternative to surgical resection and external-beam radiation for tumors and may now offer an alternative for ablation of renal lesions. We evaluated the feasibility of ablation by PRS in a normal parenchyma canine model.

MATERIALS AND METHODS

Twelve mongrel dogs were used in this survival study. In the left and right kidneys of each animal, a peripheral lesion and central-hilar lesion, respectively, were induced with PRS. The probes were placed in the renal parenchyma, and local radiation of 15 Gy at a radius of 1.3 cm was delivered over 10 minutes. Serum electrolytes were measured serially. Computed tomography scans were obtained, and the animals were sacrificed for pathologic correlation. In a separate study, the liver received three additional treatments of 10 to 20 minutes of radiation.

RESULTS

Eleven dogs survived this 6-month study and were sacrificed as scheduled. One animal expired after 2 weeks from radiation-induced fulminant hepatic failure with normal renal function. No other complications were observed. The average lesion size was 2.5 cm in diameter. Histologic analysis confirmed coagulative necrosis with sharp demarcation from the surrounding parenchyma.

CONCLUSION

Preliminary studies demonstrate the feasibility of PRS ablation of the renal parenchyma. Further tumor model testing will be important to determine the ultimate efficacy of local photon radiation energy.

Respiratory toxicity of mattress emissions in mice

Groups of male Swiss-Webster mice breathed emissions of several brands of crib mattresses for two 1-hr periods. The authors used a computerized version of ASTM-E-981 test method to monitor respiratory frequency, pattern, and airflow velocity and to diagnose abnormalities when statistically significant changes appeared. The emissions of four mattresses caused various combinations of upper-airways irritation (i.e., sensory irritation), lower-airways irritation (pulmonary irritation), and decreases in mid-expiratory airflow velocity. At the peak effect, a traditional mattress (wire springs with fiber padding) caused sensory irritation in 57% of breaths, pulmonary irritation in 23% of breaths, and airflow decrease in 11% of breaths. All mattresses caused pulmonary irritation, as shown by 17-23% of breaths at peak. The largest airflow decrease (i.e., affecting 26% of the breaths) occurred with a polyurethane foam pad covered with vinyl. Sham exposures produced less than 6% sensory irritation, pulmonary irritation, or airflow limitation. Organic cotton padding caused very different effects, evidenced by increases in both respiratory rate and tidal volume. The authors used gas chromatography/mass spectrometry to identify respiratory irritants (e.g., styrene, isopropylbenzene, limonene) in the emissions of one of the polyurethane foam mattresses. Some mattresses emitted mixtures of volatile chemicals that had the potential to cause respiratory-tract irritation and decrease airflow velocity in mice.

Insulin lispro in the treatment of patients with type 2 diabetes mellitus after oral agent failure

This study assessed the safety profile and efficacy of a new combination therapy (insulin lispro plus sulfonylurea) in patients with type 2 diabetes mellitus experiencing secondary oral agent failure. A total of 423 patients were randomly assigned to 3 treatment groups: preprandial insulin lispro plus sulfonylurea (L + S), bedtime neutral protamine Hagedorn (NPH) insulin plus sulfonylurea (N + S), and preprandial insulin lispro plus bedtime NPH insulin (L + N). Mean decreases in glycosylated hemoglobin from baseline were 1.60%+/-1.27% for patients receiving L + S, 1.21%+/-1.21% for those receiving N + S, and 1.40%+/-1.46% for those receiving L + N (within treatment, P<0.001; for L + S vs. N + S, P = 0.003). Fasting blood glucose level was higher in patients receiving L + S (171+/-46.5 mg/dL) or L + N (166+/-52.5 mg/dL) than in those receiving N + S (144+/-48.2 mg/dL) (P<0.001, for both comparisons). Conversely, postprandial blood glucose level was lower in patients receiving L + S (165+/-41.6 mg/dL) or L + N (165+/-46.3 mg/dL) than in those receiving N + S (213+/-58.3 mg/dL) (P<0.001, for both comparisons). The overall rate of hypoglycemia (episodes per 30 days) was not statistically significant when the L + S, N + S, and L + N therapies were compared (0.99+/-1.74 vs. 0.87+/-2.31 vs. 1.16+/-2.38, respectively). The rate of nocturnal hypoglycemia was lowest in the L + S group (0.00+/-0.00 vs. 0.10+/-0.37 for the N + S group vs. 0.15+/-0.54 for the L + N group; P = 0.004). L + S, which has a safety profile equal to those of N + S and L + N, is an effective treatment for patients with type 2 diabetes who experience oral sulfonylurea agent failure. L + S offers an alternative to these established combination therapies in patients whose type 2 diabetes cannot be controlled with a sulfonylurea alone.

Acute respiratory effects of diaper emissions

Mice were monitored with pneumotachographs while they breathed emissions of three brands of disposable diapers (described herein as brands A, B, and C) and one brand of cloth diapers for 1 hr. The authors used a computerized version of the ASTM-E-981 test method to measure changes in the pattern and frequency of respiration. In response to two brands of disposable diapers, many mice exhibited reduced mid-expiratory airflow velocity, sensory irritation, and pulmonary irritation. During the peak effects, brand A caused sensory irritation in 47% of the breaths and reduced mid-expiratory airflow velocity in 17% of the breaths (n = 39 mice), whereas the respective percentages noted for brand B were 20% and 15% of the breaths (n = 28 mice). The effects were generally larger during repeat exposures to these emissions, with up to 89% of breaths showing sensory irritation in response to brand A and up to 35% of breaths showing reduced mid-expiratory airflow velocity with brand B. A third brand of disposable diapers caused increases in respiratory rate, tidal volume, and mid-expiratory airflow velocity. The emissions of cloth diapers produced only slight SI and slight PI. Chemical analysis of the emissions revealed several chemicals with documented respiratory toxicity. The results demonstrate that some types of disposable diapers emit mixtures of chemicals that are toxic to the respiratory tract. Disposable diapers should be considered as one of the factors that might cause or exacerbate asthmatic conditions.

Brachytherapy optimal planning with application to intravascular radiation therapy

We have been studying brachytherapy planning with the objective of minimizing the maximum deviation of the delivered dose from prescribed dose bounds for treatment volumes. A general framework for optimal treatment planning is presented and the minmax optimization is formulated as a linear program. Dose rate calculations are based on the dosimetry formulation of the American Association of Physicists in Medicine, Task Group 43. We apply the technique to optimal planning for intravascular brachytherapy of intimal hyperplasia using ultrasound data and 192Ir seeds. The planning includes determination of an optimal dwell-time sequence for a train of seeds that deliver radiation while stepping through the vessel lesion. The results illustrate the advantage of this strategy over the common approach of delivering radiation by positioning a single train of seeds along the whole lesion.

Intra-arterial 5-fluorouracil and intravenous folinic acid in the treatment of liver metastases from colorectal cancer

OBJECTIVE

To compare two regimens of intra-arterial chemotherapy for the treatment of hepatic metastases from colorectal cancer.

DESIGN

Open study.

SETTING

Teaching hospital, UK SUBJECT: 57 patients with unresectable metastases confined to the liver, and an indwelling catheter in the hepatic artery.

INTERVENTIONS

The first 33 patients had a 24-hour intra-arterial infusion of 5-fluorouracil (5-FU) 1500 mg/m2, together with folinic acid 200 mg/m2 intravenously for the first and last two hours of the 5-FU infusion. This was repeated at weekly intervals for six weeks followed by a two-week gap before the next cycle. The remaining 24 patients had a two-weekly regimen in which folinic acid 200 mg/m2 was infused intravenously over 2 hours followed by an intra-arterial loading dose of 5-FU 400 mg/m2 over 15 minutes; 5-FU 1600 mg/m2 was then given by intra-arterial infusion over 22 hours. This was repeated on day 2 and then at two-weekly intervals.

MAIN OUTCOME MEASURES

Response rate and toxicity.

RESULTS

Median follow-up was 21 months, and estimated median survival 19 months. 29 patients (51%) have responded, 5 completely. There are no significant differences between the groups. Sites of progression were liver alone 26 (53%), lung alone 9 (18%), liver and lung 3 (6%), and the remainder in local or regional nodes (n = 7) or bone (n = 4). Six patients experienced WHO grade 3 or 4 toxicity.

CONCLUSION

The two regimens have high response rates and cause little systemic toxicity. Intra-arterial chemotherapy for hepatic metastases from colorectal cancer is currently being compared with conventional systemic chemotherapy in a randomised controlled trial.

Enhanced uptake of [11C]TPMP in canine brain tumor: a PET study

In vitro studies have demonstrated the membrane potential-dependent enhanced uptake of phosphonium salts, including [3H]triphenylmethylphosphonium (TPMP), into mitochondria of carcinoma and glioma-derived tumor cells, suggesting the potential use of phosphonium salts as tracers for tumor imaging. This study characterizes the in vivo uptake of [11C]TPMP in canine brain glioma using PET.

METHODS

Dynamic paired PET studies of [11C]TPMP followed by [68Ga]ethylenediaminetetraacetic acid (EDTA) were performed 4 d before and 9 d after tumor cell inoculation. Graphical analysis was used to evaluate [11C]TPMP retention in tumor tissue. Distribution of tracer uptake was compared with tumor histological sections.

RESULTS

[11C]TPMP exhibited enhanced uptake and prolonged retention in tumor cells. Patlak plot was linear over the 20- to 95-min postinjection period (r = 0.97 +/- 0.1). [68Ga]EDTA exhibited a gradual washout from the tumor tissue. The tumor-to-normal brain uptake ratio at 55 to 95 min postinjection was 47.5 for [11C]TPMP and 8.1 for [68Ga]EDTA. Qualitative comparison with histological sections indicated that [11C]TPMP enhanced uptake was restricted to the tumor area.

CONCLUSION

The enhanced uptake and prolonged retention in tumor suggest [11C]TPMP as a promising means for imaging of gliomas in dogs. The need for studies in humans is indicated.

Respiratory toxicity in mice exposed to mattress covers

To evaluate factors that might contribute to the rise in prevalence of childhood asthma, we allowed groups of male Swiss-Webster mice to breath the emissions of six brands of waterproof crib mattress covers for 1 h. We used a computerized version of ASTM-E-981 test method to monitor respiratory frequency, pattern, and airflow velocity. Single exposure to the emissions of these mattress covers caused various combinations of sensory irritation, pulmonary irritation, and decreases in mid-expiratory airflow velocity. At the peak effects of these emissions, sensory irritation ranged from 9% to 51% of the breaths, pulmonary irritation ranged from 4% to 16% of the breaths, and airflow limitation ranged from 9% to 38% of the breaths. Three brands caused airflow limitation that persisted for at least 24 h after a single 1-h exposure of naive mice to these emissions. Repeat exposures to the emissions of four brands caused more marked effects (i.e., up to 96% of the breaths showing sensory irritation, up to 44% of the breaths showing pulmonary irritation, and up to 75% of the breaths showing airflow limitation). Histological evaluation of the lungs revealed a mild inflammatory response, with focal collections of polymorphonuclear leukocytes and edema, but there were no eosinophils and no bronchial mucosa changes. We used gas chromatography/mass spectrometry to evaluate one of the test atmospheres, and there was evidence of chemicals for which toxic properties have been documented previously. The results of our study demonstrated that some mattress covers emit mixtures of chemicals that can cause a variety of acute toxic effects in mice, including asthma-like reactions.

Long-term efficacy of humalog in subjects with Type 1 diabetes mellitus

AIMS

To evaluate the long-term effectiveness of Humalog insulin in lowering post meal glucose excursions.

METHODS

Twenty young subjects with Type 1 diabetes mellitus (DM) who had received insulin-lispro (Humalog) for a least 1 year (mean +/- SD 1.8+/-1.6 years) were studied on two occasions, 3-14 days apart. They consumed a similar breakfast consisting of 450-600 kCal having fasted overnight. The same amount of human soluble Humulin Regular or Humalog insulin was given 10 min before the meal in a randomized, double-blind fashion.

RESULTS

Postprandial glucose excursions at 30, 60, and 120 min were significantly lower (P<0.001, ANCOVA) when subjects received Humalog as compared to human soluble insulin. Serum-free insulin levels were significantly higher (P<0.001, ANOVA) at 30 and 60 min when subjects received Humalog as compared with human soluble insulin. Humalog antibody levels after up to 5.4 years of receiving Humalog insulin were not elevated beyond the values at 1 year.

CONCLUSIONS

We conclude that Humalog insulin is effective in lowering postprandial glucose excursions even after up to 5.4 years of treatment.

Sensory irritation and multiple chemical sensitivity

Many of the symptoms described in Sick Building Syndrome (SBS) and multiple chemical sensitivity (MCS) resemble the symptoms known to be elicited by airborne irritant chemicals. Irritation of the eye, nose, and throat is common to SBS, MCS, and sensory irritation (SI). Difficulty of breathing is often seen with SBS, MCS, and pulmonary irritation (PI). We therefore asked the question: can indoor air pollutants cause SI and/or PI? In laboratory testing in which mice breathed the dilute volatile emissions of air fresheners, fabric softeners, colognes, and mattresses for 1 h, we measured various combinations of SI and PI as well as airflow decreases (analogous to asthma attacks). Air samples taken from sites associated with repeated human complaints of poor air quality also caused SI, PI, and airflow limitation (AFL) in the mice. In previous publications, we have documented numerous behavior changes in mice (which we formally studied with a functional observational battery) after exposure to product emissions or complaint site air; neurological complaints are a prominent part of SBS and MCS. All together, these data suggest that many symptoms of SBS and MCS can be described as SI, PI, AFL, and neurotoxicity. All these problems can be caused by airborne irritant chemicals such as those emitted by common commercial products and found in polluted indoor air. With some chemical mixtures (e.g., emissions of some fabric softeners, disposable diapers, and vinyl mattress covers) but not others (e.g., emissions of a solid air freshener), the SI response became larger (2- to 4-fold) when we administered a series of two or three 1-h exposures over a 24-h period. Since with each exposure the intensity of the stimulus was constant yet the magnitude of the response increased, we concluded that there was a change in the sensitivity of the mice to these chemicals. The response was not a generalized stress response because it occurred with only some mixtures of irritants and not others; it is a specific response to certain mixtures of airborne chemicals. This is one of the few times in MCS research that one can actually measure both the intensity of the stimulus and the magnitude of the response and thus be allowed to discuss sensitivity changes. The changing SI response of the mice might serve as a model of how people develop increasing sensitivity to environmental pollutants. Intensive study of this system should teach us much about how people respond to and change sensitivity to airborne irritant chemicals.