Impact of blue light therapy on plasma adrenocorticotropic hormone (ACTH) and hypertrichosis in horses with pituitary pars intermedia dysfunction

Blue light therapy can be used in horses to alter the natural photoperiod and inhibit winter hair coat growth. Seasonal increases in ACTH occur in the fall season but are exaggerated in horses with pituitary pars intermedia dysfunction (PPID). Additionally, PPID horses frequently present with hypertrichosis. Thus, blue light therapy was proposed as a potential management tool for hypertrichosis and for investigating the impact of photoperiod manipulation on ACTH. Eighteen PPID horses, aged 18 to 31 yr, from a university-owned research herd were selected and assigned to either the control group (n = 10) or the treatment (blue light therapy) group (n = 8) based on age and clinical history, which included the results of multiple endocrine tests. Consistent daylength of approximately 14.5 h was maintained for the treated horses from July 15 through approximately late October via the extension of natural daylength using wearable masks that provided short wavelength blue light (465 nm) to 1 eye. The control group was exposed to only the natural photoperiod during this time. All horses were housed on the same farm and remained on pasture for the duration of the study. On Day 0, thyrotropin-releasing hormone (TRH) stimulation tests were performed to confirm PPID status; there were no differences between the 2 groups in resting plasma ACTH or plasma ACTH at 10 min after TRH administration. To determine an effect of treatment on ACTH, blood was collected via jugular venipuncture for measurement of ACTH at sequential timepoints over a 16-h period in mid-October. Hair weights were also assessed throughout the study. No differences in resting plasma ACTH were observed between the 2 groups across the seasonal analysis (July and October) or during the 16-h testing. The PPID horses receiving blue light therapy had lighter hair weights compared to the PPID control horses. These results suggest that blue light therapy does not alter ACTH concentrations but could potentially be used as an additional management tool for hypertrichosis in PPID horses. Manipulation of the photoperiod using blue light therapy did not affect seasonal changes in ACTH in this study.

Effects of blue monochromatic light directed at one eye of pregnant horse mares on gestation, parturition and foal maturity

Blue light directed at 1 eye advances the equine ovulatory season but may also advance foaling. In this study, effects of blue LED light on pregnancy outcome were assessed. A total of 20 mares with singleton pregnancies were studied over 2 consecutive years in a cross-over design. In 1 year, mares received an extended photoperiod using 50 lux of blue LED light (468 nm) directed at a single eye from 08:00 until 23:00 daily via head-worn light masks starting mid-December and in the other year remained untreated as controls. Gestation was shorter in blue LED light-treated than in control pregnancies (median 333.0 vs 338.5 days, P = 0.036). Foals born to blue LED light-treated mares had lower wither heights (median 103.0 vs 104.5 cm, P = 0.023), similar weights (median 55.8 vs 54.8 kg, P = 0.732) and took less time to stand after birth than control foals (median 35.0 vs 53.5 min, P = 0.036). Foals born to blue LED light-treated mares had reduced hair length compared to controls (median 12.0 vs 20.0 mm, P = 0.009) and hair regrowth in treated mares was reduced (P = 0.036). In conclusion, blue LED light directed at 1 eye advanced foaling and influenced height and hair coat but not weight in foals.

Evidence of a molecular clock in the ovine ovary and the influence of photoperiod

The influence of the central circadian clock on reproductive timing is well established. Much less is known about the role of peripheral oscillators such as those in the ovary. We investigated the influence of photoperiod and timing of the LH surge on expression of circadian clock genes and genes involved in steroidogenesis in ovine ovarian stroma. Seventy-two Suffolk cross ewes were divided into two groups, and their estrous cycles were synchronized. Progestagen sponge removal was staggered by 12 hours between the groups such that expected LH peak would occur midway through either the light or dark phase of the photoperiodic cycle. Four animals from each group were killed, and their ovaries were harvested beginning 36 hours after sponge removal, at 6-hour intervals for 48 hours. Blood was sampled every 3 hours for the period 24 to 48 hours after sponge removal to detect the LH surge. The interval to peak LH did not differ between the groups (36.2 ± 1.2 and 35.6 ± 1.1 hours, respectively). There was an interaction between group and the time of sponge removal on the expression of the core clock genes ARNTL, PER1, CRY1, CLOCK, and DBP (P < 0.01, P < 0.05, P < 0.01, P < 0.01, and P < 0.01, respectively). As no significant interaction between group and time of day was detected, the datasets were combined. Statistically significant rhythmic oscillation was observed for ARNTL, CLOCK, CRY1 (P < 0.01, respectively), PTGS2, DBP, PTGER2, and CYP17A1 (P < 0.05, respectively), confirming the existence of a time-sensitive functionality within the ovary, which may influence steroidogenesis and is independent of the ovulatory cycle.

A 3'-UTR KRAS-variant is associated with cisplatin resistance in patients with recurrent and/or metastatic head and neck squamous cell carcinoma

BACKGROUND

A germline mutation in the 3'-untranslated region of KRAS (rs61764370, KRAS-variant: TG/GG) has previously been associated with altered patient outcome and drug resistance/sensitivity in various cancers. We examined the prognostic and predictive significance of this variant in recurrent/metastatic (R/M) head and neck squamous cell carcinoma (HNSCC).

PATIENTS AND METHODS

We conducted a retrospective study of 103 HNSCCs collected from three completed clinical trials. KRAS-variant genotyping was conducted for these samples and 8 HNSCC cell lines. p16 expression was determined in a subset of 26 oropharynx tumors by immunohistochemistry. Microarray analysis was also utilized to elucidate differentially expressed genes between KRAS-variant and non-variant tumors. Drug sensitivity in cell lines was evaluated to confirm clinical findings.

RESULTS

KRAS-variant status was determined in 95/103 (92%) of the HNSCC tumor samples and the allelic frequency of TG/GG was 32% (30/95). Three of the HNSCC cell lines (3/8) studied had the KRAS-variant. No association between KRAS-variant status and p16 expression was observed in the oropharynx subset (Fisher's exact test, P = 1.0). With respect to patient outcome, patients with the KRAS-variant had poor progression-free survival when treated with cisplatin (log-rank P = 0.002). Conversely, KRAS-variant patients appeared to experience some improvement in disease control when cetuximab was added to their platinum-based regimen (log-rank P = 0.04).

CONCLUSIONS

The TG/GG rs61764370 KRAS-variant is a potential predictive biomarker for poor platinum response in R/M HNSCC patients.

CLINICAL TRIAL REGISTRATION NUMBERS

NCT00503997, NCT00425750, NCT00003809.

Exercise influences circadian gene expression in equine skeletal muscle

Circadian rhythms are endogenously generated 24-h oscillations that coordinate numerous aspects of mammalian physiology, metabolism and behaviour. The existence of a molecular circadian clock in equine skeletal muscle has previously been demonstrated. This study investigates how the circadian 24-h expression of exercise-relevant genes in skeletal muscle is influenced by a regular exercise regime. Mid-gluteal, percutaneous muscle biopsies were obtained over a 24-h period from six Thoroughbred mares before and after an 8-week exercise programme. Real-time qPCR assays were used to assess the expression patterns of core clock genes ARNTL, PER2, NR1D1, clock-controlled gene DBP, and muscle genes MYF6, UCP3, VEGFA, FOXO1, MYOD1, PPARGC1A, PPARGC1B, FBXO32 and PDK4. Two-way repeated measures ANOVA revealed a significant interaction between circadian time and exercise for muscle genes MYF6, UCP3, MYOD1 and PDK4. A significant effect of time was observed for all genes with the exception of VEGFA, where a main effect of exercise was observed. By cosinor analysis, the core clock genes, ARNTL (P <0.01) and NR1D1 (P <0.05), showed 24-h rhythmicity both pre- and post-exercise, while PER2 expression was rhythmic post-exercise (P <0.05) but not pre-exercise. The expression profiles of muscle genes MYOD1 and MYF6 showed significant fits to a 24-h cosine waveform indicative of circadian rhythmicity post-exercise only (P <0.01). This study suggests that the metabolic capacity of muscle is influenced by scheduled exercise and that optimal athletic performance may be achieved when exercise times and competition times coincide.

Blue light from individual light masks directed at a single eye advances the breeding season in mares

REASONS FOR PERFORMING STUDY

Artificial lighting is commonly used to advance the breeding season in horses. Light masks have been developed that direct light at a single eye to inhibit the production of melatonin, the decoder of photoperiod for seasonally breeding animals.

OBJECTIVES

To investigate whether low-intensity blue light from light masks was effective at advancing the breeding season in mares.

STUDY DESIGN

Controlled experiment.

METHODS

Data on reproductive activity was collected from 3 groups of mares maintained on Kentucky horse farms under various lighting conditions between 20 November 2011 and 10 February 2012: 59 nonpregnant, healthy Thoroughbred mares were used. On 1 December 2011, Group 1 (n = 16) was housed indoors under barn lighting (250 Lux) until 23.00 h daily. Group 2 (n = 25) wore light masks programmed to turn on from 16.30 h until 23.00 h daily and was maintained outdoors. Group 3 (n = 19) was maintained outdoors under the natural photoperiod as control. At 2-week intervals, rectal ultrasound examinations were performed and blood was collected for progesterone analysis. Oestrous cyclicity was defined as the presence of follicles >20 mm diameter detected in conjunction with serum progesterone >1 ng/ml and confirmation of ovulation by transrectal ultrasound examination.

RESULTS

On 10 February, the number of mares exhibiting oestrous cyclicity was 14/16 (87.5%) in Group 1; 20/25 (80%) in Group 2; and 4/19 (21%), in Group 3. Pairwise comparison of groups revealed no difference in the number of cycling mares between Groups 1 and 2 (χ(2) test, P = 0.3348) whereas differences were observed between Groups 1 and 3 (χ(2) test, P<0.0001) and Groups 2 and 3 (χ(2) test, P<0.0003).

CONCLUSIONS

Low-intensity blue light to a single eye from a light mask is an effective alternative to maintenance of mares indoors under lights for advancing the breeding season. Mobile light therapy for horses could have economic benefits for the breeder by reducing the costs of maintaining mares indoors, and welfare benefits for horses by permitting outdoor maintenance.

Blue light from light-emitting diodes directed at a single eye elicits a dose-dependent suppression of melatonin in horses

The production of melatonin during night-time hours decodes day length for seasonally breeding animals. The use of artificial light to advance the breeding season in mares is common practice within the equine industry. Four healthy Thoroughbred mares were used to evaluate the minimum intensity of light required to inhibit serum melatonin. Mares were fitted with indwelling jugular catheters and using a crossover design blood samples were collected following 1h exposure to light (barn lighting approximately 200 lux), dark (<0.1 lux), and 3, 10, 50, and 100 lux intensities. The light source was a light-emitting diode (LED; 468 nm) directed at either a single eye or both eyes. All treatments, except the sample collected after 1 h exposure to light, occurred during the dark phase of the 24 h cycle. Serum melatonin levels were determined by radioimmunoassay. Two-way repeated measures ANOVA revealed that there was no difference between the level of melatonin inhibition achieved when light was administered to one or two eyes (P = 0.7028). One-way ANOVA of melatonin levels at light intensities of 10, 50 and 100 lux were significantly different to dark (P < 0.05) and not different to light (P > 0.05) intensities. There was no difference between melatonin levels at 3 lux (P > 0.05) and dark intensities. The threshold level of low wavelength light required to inhibit melatonin production in the horse lies between 3 and 10 lux. Melatonin inhibition can be achieved by exposing a single eye to low wavelength blue light. This is a novel finding with important implications for management of artificial lighting regimens in horses.

Osteomark: a surgical navigation system for oral and maxillofacial surgery

The purpose of this project was to test a surgical navigation tool designed to help execute a surgical treatment plan. It consists of an electromagnetically tracked pencil that is used to mark bone intraoperatively. The device was tested on a precision block, an ex vivo pig mandible and during performance of six endoscopic vertical ramus osteotomies on pig cadavers. The difference between actual pencil position and that displayed by the computer was measured three times each at ten 2mm holes on the block (n=30 observations) and on the ex vivo mandible (n=11 measurements). Errors between planned and actual osteotomy locations for the cadaver procedures were measured. The mean distance between known and displayed locations was 1.55 ± 0.72 mm on the precision block and 2.10 ± 0.88 mm on the pig mandible. The error measured marking the same point on the block multiple (n=5) times was 0.58 ± 0.37 mm. The mean error on the simulated osteotomies was 2.35 ± 1.35 mm. Osteomark was simple to use and permitted localisation of holes and osteotomies with acceptable accuracy. In the future, the device and algorithms will be revised to further decrease error and the system will be tested on live animals.

How best to measure the levator hiatus: evidence for the non-Euclidean nature of the 'plane of minimal dimensions'

OBJECTIVE

To clarify whether the 'plane of minimal dimensions' of the levator hiatus on three-dimensional (3D) ultrasound accurately represents the minimal anatomical transverse hiatal dimension during a Valsalva maneuver.

METHODS

In this retrospective study of 3D transperineal ultrasound and magnetic resonance (MR) imaging, datasets from 19 female participants were used to measure the transverse diameter of the levator hiatus using the plane of minimal dimensions on maximum Valsalva maneuver. The term 'apparent minimal transverse diameter' (aMTD) was used to define the transverse diameter measured using axial ultrasound and comparable axial or coronal MR images. Coronal MR images, using the plane of the vagina as a reference, were also obtained on maximum Valsalva. The transverse diameter measured between the caudal margin of the pubococcygeus/puborectalis on the MR coronal image is denoted by the term 'true minimal transverse diameter' (tMTD). Statistical comparisons between the aMTD and tMTD were made using Student's t-test.

RESULTS

No significant difference was demonstrated between the aMTD as measured by ultrasonography and MRI. However, there were significant differences found between the aMTD measured by both ultrasound and MRI and the tMTD measured on coronal MR images (both P < 0.01), with mean ( ± SD) values of 4.36 ± 0.85, 4.13 ± 1.09 and 3.23 ± 0.49 cm, respectively.

CONCLUSION

This study highlights the complexity and 3D nature of the levator hiatus and pelvic floor muscles. Investigators have previously assumed that the plane of minimal dimensions of the hiatus can be measured in a flat plane, however, the 3D nature of the hiatus means that the true levator hiatus occupies a warped (non-Euclidean) plane. Hiatal measurements on Valsalva may be subject to systematic error if performed in a single section, i.e. using a flat (Euclidean) plane.

Nuclear factor-kappa B pathway and response in a phase II trial of bortezomib and docetaxel in patients with recurrent and/or metastatic head and neck squamous cell carcinoma

BACKGROUND

Our previous study has shown that nuclear factor-kappa B (NF-kappaB)-signaling pathway was associated with a higher rate of recurrence in head and neck squamous cell carcinoma (HNSCC). The combination of bortezomib, an NF-kappaB inhibitor by inhibition of proteasomes, plus docetaxel was assessed for efficacy and toxicity.

MATERIALS AND METHODS

Patients with recurrent and/or metastatic HNSCC were enrolled on a phase II bortezomib/docetaxel trial (bortezomib 1.6 mg/m(2) and docetaxel 40 mg/m(2) on days 1 and 8 of a 21-day cycle). Response was assessed using RECIST. Tissue specimens were evaluated for the presence of human papillomavirus (HPV) and expression of NF-kappaB-associated genes.

RESULTS

Twenty-one of 25 enrolled patients were assessable for response; one partial response (PR, 5%), 10 stable disease (SD, 48%) and 10 progressive disease (PD, 48%). Patients with PR/SD had significantly longer survival compared with patients with PD and the regimen was well tolerated. Only one of 20 tumors was positive for HPV. Patients with PD had higher expression of NF-kappaB and epidermal growth factor receptor-associated genes in their tumors by gene expression analysis.

CONCLUSION

Further understanding of treatment resistance and interactions between bortezomib and docetaxel may provide novel approaches in managing HNSCC.

Longitudinal oncology registry of head and neck carcinoma (LORHAN): First report of outcomes

6071

Background: Registries can be invaluable for describing patterns of care and outcomes for a population of patients (pts). We report the initial survival findings from LORHAN, a prospective, longitudinal, observational national registry of head and neck carcinoma (HNC) pts. Methods: Pts are eligible for LORHAN if they have newly diagnosed HNC, are scheduled to receive radiotherapy (RT) or drug therapy, are ≥18 years of age and have provided written informed consent. Data are entered in the registry electronically and transferred via Secure HTTP protocols. Patient confidentiality is strictly maintained. Pts are followed from time of initial diagnosis and for a minimum of 2 and up to 10 years. When information is complete and has been verified and signed off by the investigator, a record is locked. Only locked records are summarized and reported. Results: 2,354 pts have been enrolled in LORHAN since Dec. 2005. Of these, 1,326 pts have completed initial cancer treatment and have locked records. 1- and 2-year follow-up data are available for 583 and 56 pts, respectively. Baseline characteristics were similar between settings, except that pts treated at academic centers were significantly younger (58 vs. 62 years of age), had poorer performance status (mean Zubrod: 0.9 vs. 0.7), had fewer laryngeal tumors (17% vs. 27% of pts) but more oropharyngeal tumors (42% vs. 37% of pts) and presented with more advanced disease (stage IV: 70% vs. 48% of pts) compared to pts treated in community. Treatment did not differ by setting. Treatment and survival data are shown below. Conclusions: LORHAN demonstrates it is feasible to collect more detailed information about patient and tumor features and treatment other than surgery. Changes in the pattern of care and survival findings are expected to emerge as newer regimens, including IC and targeted agents, are incorporated more broadly into clinical practice, and data in LORHAN matures.

[Table: see text]

[Table: see text]

Mass spectrometry profile as a predictor of overall survival benefit after treatment with epidermal growth factor receptor inhibitors in head and neck squamous cell carcinoma

6000

Background: Our previous study has shown that a matrix-assisted laser desorption ionization (MALDI) mass spectrometry (MS) profile in serum or plasma can predict lung cancer patient survival after treatment with epidermal growth factor receptor inhibitors (EGFRI). We examined the ability of this same MALDI-MS profile in plasma or sera to predict for survival benefit of EGFRIs in patients with head and neck squamous cell carcinoma (HNSCC). Methods: Spectra were obtained in triplicate using MALDI-MS from 314 samples obtained from five HNSCC cohorts treated with 1) gefitinib (G, n = 100); 2) erlotinib and bevacizumab (E/B, n = 81); 3) cetuximab (C, n = 21); 4) surgery (S, n = 78); and 5) palliative chemotherapy (PC, n = 34). Each sample was classified into “good” or “poor” outcome groups and overall survival was examined using this MALDI-MS classifier (VeriStrat, Biodesix, Steamboat Springs, CO). Results: Successful classification could be achieved in 311/314 (98%) of the samples. In all EGFRI-treated cohorts, the classifier predicted survival benefit while the cohorts without EGFRI-treatment showed no survival difference by log-rank testing (G: p = 0.007, HR 0.41, 95%-CI 0.22–0.79; E/B: p = 0.02, HR 0.20, 95%-CI 0.05–0.78; C: p=0.06, HR 0.26, 95%-CI 0.06–1.06; and PC: p = 0.76, HR 0.88, 95%-CI 0.4–1.97), independent of performance status, age, gender and smoking history. Conclusions: This study suggests that the same predictive algorithm for MALDI-MS generated from patients with lung cancer treated with EGFRIs is also predictive of survival outcome in HNSCC patients treated with both TKIs and cetuximab, and may allow rational selection of patients most likely to benefit from an EGFRI monotherapy.

[Table: see text]

Pelvic floor function in elite nulliparous athletes

OBJECTIVE

There is preliminary evidence linking long-term participation in high-impact exercise with poor performance in labor and increased incidence of stress urinary incontinence, which may be due to altered pelvic floor function. Recent work has shown that HIFIT (high-impact, frequent intense training) athletes have an increased cross-sectional area of the levator ani muscle group as visualized using magnetic resonance imaging (MRI). The aim of this study was to further characterize pelvic floor muscle function and pelvic organ descent in a nulliparous athletic population and compare it with non-athletic controls matched for age and body mass index, using three-dimensional/four-dimensional (3D/4D) pelvic floor ultrasound imaging.

METHODS

In this prospective comparative study translabial ultrasound imaging was used to assess pelvic floor anatomy and function in 46 nulliparous female volunteers (aged 19-39 years), 24 HIFIT and 22 controls. Two-dimensional (2D) and 3D translabial ultrasonography was performed on all subjects, after voiding and in the supine position. Descent of the pelvic organs was assessed on maximum Valsalva maneuver, whilst volume datasets were acquired at rest, during pelvic floor muscle contraction and during a Valsalva maneuver. Participants performed each maneuver at least three times and the most effective was used for evaluation.

RESULTS

HIFIT athletes showed a higher mean diameter of the pubovisceral muscle (0.96 cm vs. 0.70 cm, P < 0.01), greater bladder neck descent (22.7 mm vs. 15.1 mm, P = 0.03) and a larger hiatal area on Valsalva maneuver (21.53 vs. 14.91 cm(2), P = 0.013) compared with the control group. There were no significant differences in hiatal area at rest or on maximal voluntary contraction between the two groups.

CONCLUSION

HIFIT athletes show significant differences in several of the measured parameters for both function and anatomy of the pelvic floor. Further research into the impact of this altered function on childbirth and continence mechanisms is needed.

Assessment of cancer pain

19500

Background: This study investigates: 1) The concordance between patients and staffs’ standard use of the numerical rating scale (NRS) for pain, in which 1–4 is mild pain, 5–6 is moderate and 7 and above is severe; 2) The relative importance of functional impairment secondary to pain in patients’ pain ratings. Methods: Patients with cancer and current or previous pain (N=178) were asked to complete a fifteen minute interview with open-ended questions about their perception of pain. Results: When asked to define mild, moderate and severe pain according to the NRS, 65% of patients gave numbers that did not meet standard definitions as noted above. When asked to define mild, moderate and severe pain in general, 38% differentiated severity of pain based on its impact on their ability to fulfill activities of daily living (ADLs) and 39% differentiated it based on their emotional reactions. When asked to define tolerable pain, 28% described it in terms of its impact on ADLs, while 30% described it in terms of the NRS. For those patients who used a NRS, the mean value for tolerable pain was 4.9 (range 2–8) and the mean value for intolerable pain was 8.1 (range 5–10). 26% of patients defined satisfactory pain control based its impact on ADLs while only 2% defined it according to a NRS. 68% of patients reported that pain interfered with their ADLs, however only 33% reported that pain medication interfered. Conclusions: There is discordance between the standard definition of the NRS and patient perceptions of it, suggesting it should be supplemented by other types of pain assessment. Based on NRS, patients tolerate higher levels of pain than expected. Patient satisfaction with pain control is more dependent upon ability to complete ADLs than on a numerical rating of pain. Therefore, patients’ ability to function at an acceptable level should be part of the standard pain assessment.

No significant financial relationships to disclose.

Changes in Excitability of the Cortical Projections to the Human Tibialis Anterior After Paired Associative Stimulation

Paired associative stimulation (PAS) based on Hebb's law of association can induce plastic changes in the intact human. The optimal interstimulus interval (ISI) between the peripheral nerve and transcranial magnetic stimulus is not known for muscles of the lower leg. The aims of this study were to investigate the effect of PAS for a variety of ISIs and to explore the efficacy of PAS when applied during dynamic activation of the target muscle. PAS was applied at 0.2 Hz for 30 min with the tibialis anterior (TA) at rest. The ISI was varied randomly in seven sessions ( n = 5). Subsequently, PAS was applied ( n = 14, ISI = 55 ms) with the TA relaxed or dorsi-flexing. Finally, an optimized ISI based on the subject somatosensory evoked potential (SEP) latency plus a central processing delay (6 ms) was used ( n = 13). Motor-evoked potentials (MEPs) were elicited in the TA before and after the intervention, and the size of the TA MEP was extracted. ISIs of 45, 50, and 55 ms increased and 40 ms decreased TA MEP significantly ( P = 0.01). PAS during dorsi-flexion increased TA MEP size by 92% ( P = 0.001). PAS delivered at rest resulted in a nonsignificant increase; however, when the ISI was optimized from SEP latency recordings, all subjects showed significant increases ( P = 0.002). No changes in MEP size occurred in the antagonist. Results confirm that the excitability of the corticospinal projections to the TA but not the antagonist can be increased after PAS. This is strongly dependent on the individualized ISI and on the activation state of the muscle.

Relationships among inflammatory cytokines, obesity, and insulin sensitivity in the horse

Recent studies associate obesity and insulin resistance in horses with development of abnormal reproductive function and debilitating laminitis. The factors contributing to insulin resistance in obese horses are unknown. However, human studies provide evidence that elevated inflammatory cytokines such as tumor necrosis factor alpha (TNFalpha), IL1, and IL6 play direct roles in development of obesity-associated insulin resistance. Thus, inflammation may be a key link between obesity and insulin resistance in horses. The aim of the current investigation was to examine possible relationships between obesity, inflammatory cytokines, and insulin sensitivity (IS) in the horse. Age was recorded and BCS and percent body fat (% FAT) were determined as measures of obesity in 60 mares. In addition, blood mRNA expression of IL1, IL6, and TNFalpha and circulating concentrations of TNFalpha protein (TNFp) were determined in each mare. Finally, fasted concentrations of insulin were determined, and IS was determined using the hyperinsulinemic, euglycemic clamp. Significant correlations between several variables provided evidence for the design of 4 population regression models to estimate relationships between measures of obesity, inflammatory factors, and IS in the sample population. The results of these analyses revealed that IS decreased as BCS and % FAT increased (P < 0.001) in the sample population. Additionally, increased IL1 (P < 0.05) and TNFp (P < 0.01) were associated with decreased IS. However, increased TNFalpha (P < 0.001) was associated with decreased IS only in mares 20 yr of age and older. Increased BCS and % FAT were associated with increased expression of TNFalpha (P = 0.053) and IL1 (P < 0.05), and increased TNFp (P < 0.05). Surprisingly, increased BCS and % FAT were associated with decreased IL6 expression (P = 0.05) in mares <20 yr of age. Finally, evaluation of the influence of obesity and inflammatory cytokines on IS within the same model suggested that BCS and % FAT (P < 0.001) with TNFalpha [mRNA (P = 0.07) and protein (P < 0.05)] are inversely associated with IS independently of one another. Combined, these results provide the first evidence associating obesity with increased inflammatory factors in the horse. Furthermore, the results suggest that an interrelationship exists among obesity, inflammatory cytokines, and IS in the horse and emphasize the need for further studies to elucidate the nature of these relationships.

Altered cortical integration of dual somatosensory input following the cessation of a 20 min period of repetitive muscle activity

The adult human central nervous system (CNS) retains its ability to reorganize itself in response to altered afferent input. Intracortical inhibition is thought to play an important role in central motor reorganization. However, the mechanisms responsible for altered cortical sensory maps remain more elusive. The aim of the current study was to investigate changes in the intrinsic inhibitory interactions within the somatosensory system subsequent to a period of repetitive contractions. To achieve this, the dual peripheral nerve stimulation somatosensory evoked potential (SEP) ratio technique was utilized in 14 subjects. SEPs were recorded following median and ulnar nerve stimulation at the wrist (1 ms square wave pulse, 2.47 Hz, 1x motor threshold). SEP ratios were calculated for the N9, N11, N13, P14-18, N20-P25 and P22-N30 peak complexes from SEP amplitudes obtained from simultaneous median and ulnar (MU) stimulation divided by the arithmetic sum of SEPs obtained from individual stimulation of the median (M) and ulnar (U) nerves. There was a significant increase in the MU/M + U ratio for both cortical SEP components following the 20 min repetitive contraction task, i.e. the N20-P25 complex, and the P22-N30 SEP complex. These cortical ratio changes appear to be due to a reduced ability to suppress the dual input, as there was also a significant increase in the amplitude of the MU recordings for the same two cortical SEP peaks (N20-P25 and P22-N30) following the typing task. No changes were observed following a control intervention. The N20 (S1) changes may reflect the mechanism responsible for altering the boundaries of cortical sensory maps, changing the way the CNS perceives and processes information from adjacent body parts. The N30 changes may be related to the intracortical inhibitory changes shown previously with both single and paired pulse TMS. These findings may have implications for understanding the role of the cortex in the initiation of overuse injuries.

Swallowing function for patients treated on E2399: A phase II trial of function preservation with induction paclitaxel/carboplatin followed by radiation plus weekly paclitaxel

5524

ECOG 2399 is a phase II organ preservation study using induction chemotherapy followed by concomitant chemoradiation in unresectable patients with squamous cancer of the larynx or oropharynx. A correlative study was undertaken to assess acute and long-term swallowing. Methods: Swallow evaluations were done at baseline, 3, 12 and 24 months posttreatment. Self-report measures consisted of the PSS-HN and FACT-HN. Objective measures include the Modified Barium Swallow (MBS) scored using a physiologic measure, the Dysphagia Outcome Severity Scale (D) and a functional measure, the Functional Communication Measure (F). Both D and F are graded on a 7-point scale (7 = normal through 1 = absent swallow/unable to take p.o). Results: The number of evaluable D and F assessments at each time point: baseline 97/99, 3 months 72/73, 12 months 40/41, 24 months 24/26. The scores presented in the table are expressed in percentages. Conclusions: The majority of patients presented with objective abnormalities on MBS, but swallow function remained largely intact. At 3 months, swallowing was markedly impaired (severe 18 and 24%, moderate 20 and 21%). By 12 months, swallowing had improved for most patients; however, a significant percentage of patients had persistent mild deficits (5–6). Severe swallowing abnormalities were found in less than 10% of patients at 12 and 24 months. Sponsored, in part, by Bristol-Myers-Squibb.

[Table: see text]

[Table: see text]

Oral mucositis (OM) related morbidity and resource utilization in a prospective study of head and neck cancer (HNC) patients

5539

Background: Few studies have reported the burden of oropharyngeal mucositis (OM) as well as the downstream resource consumption and risk of complications due to OM following standard therapy in head and neck cancer patients. This study was a prospective, multi-center, single-arm observational study of patients receiving radiation with or without chemotherapy for head and neck cancer. Methods: Over a 6-week period, the severity and impact of OM were assessed 5 times with the oral mucositis weekly questionnaire (OMWQ-HN) and patient resource use was collected bi-weekly. Seventy-five patients were enrolled from 6 centers in the United States. Hospitalization costs are reported from the Healthcare Utilization Project Nationwide Inpatient Sample (HUPNIS). Results: Sixty-seven percent (95% CI: 55%–77%) of the patients received concurrent chemoradiation. Seventy-six percent (95% CI: 65%–85%) of patients reported severe mouth and throat soreness. Eighty-five percent (95% CI: 75%-92%) were prescribed opioid analgesics. Mouth pain and throat pain accounted for 78% (95% CI: 68%–86%) of opioid uses. During weeks 1 and 2, 38% (95% CI: 26%-50%) of patients reported severe difficulty swallowing (59% by week 6); 67% (95% CI: 46%-83%) of these patients were taking opioids (84% by week 6). Over half of the patients (38/75; 51% [95% CI: 39%–62%]) had a feeding tube placed. Twenty-eight patients (37% [95% CI: 26%–49%]) were hospitalized, 30% (95% CI: 16%–49%) of hospitalizations were considered related to mucositis. Mean length of stay was 4.9 days (range: 1–16, SE: 0.72). National average cost for a 5-day hospitalization during this study period was approximately $23,000 (SE: $565.00 [HUPNIS]). Conclusions: Mucositis is a frequent, severe, and costly complication of treatment for head and neck cancer. Effective interventions may not only relieve patient suffering but also reduce healthcare consumption and downstream costs.

[Table: see text]

Phase II trial of trastuzumab (T), paclitaxel (P) and cisplatin (C) in metastatic (M) or recurrent (R) head and neck squamous cell carcinoma (HNSCC): Response by tumor EGFR and HER2/neu status

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Background: EGFR expression is associated with poor prognosis and resistance of HNSCC to therapy. EGFR/Her2/neu heterodimers may potentiate receptor signaling and therapy resistance. T enhances cytotoxic effects of C and P in Her2/neu+ cell lines. Methods: A phase II trial evaluated the response rate (RR) of HNSCC pts to TPC as a function of Her2/neu and EGFR expression by immunohistochemistry (IHC). Secondary outcomes included toxicity, one-year progression-free (PFS) and overall (OS) survival. Eligible pts had M or R HNSCC, ECOG PS 0–1, CrCl >50 ml/min, and ANC >1500. Chemotherapy regimen consisted of P (175 mg/m2) and C (75 mg/m2) IV on day 1 and T (4 mg/kg day 1, cycle 1, 2 mg/kg subsequent) IV on day 1, 8 and 15 of 21. Paraffin embedded tumor was analyzed for Her2/neu (HercepTest) and EGFR (Zymed Lab) expression by IHC and for Her2/neu amplification by FISH (−/+) at LabCorp. Two-stage Simon design had 80% power for a 15% improvement in RR over 35% and required response in ≥ 14/42 pts by ECOG response criteria. Results: 61 pts (55 R HNSCC) received a median of 4 cycles (range 1–14) of TPC. Membrane staining of ≥ 10% of cells was observed for Her2/neu in 4/58 (6.9%, 95% CI 2–17) and for EGFR in 41/57 (72%, 95% CI 58–83). Her2/neu amplification was absent in 55/55 (0%, one-sided 97.5% CI 0–6.7) tumors. A RR of 36% (95% CI 24–50) was observed in 58 evaluable pts. RR was lower in pts with ≥ 10% staining by EGFR (25% versus 62.5%, p = 0.01). Her2/neu expression had no effect on RR (p = 0.75). Toxicities included two grade 5 dehydration/hypokalemia, and grade 3–4 neutropenia, fatigue, infection, nausea, vomiting, and neuropathy were common. Median follow-up was 4.2 yrs. For all 61 pts: median TTP was 4.3 mos, PFS 19.8% (95% CI 10.6–30.9) and OS 44% (95% CI 31.6–56.2) at 1 yr. Pts with <10% EGFR membrane staining had improved median PFS (6.7 vs 3.1 mos, p = 0.003) and OS (16.1 vs 7.4 mos, p = 0.005) when compared to patients with tumors with ≥ 10% EGFR. Conclusions: T did not improve RR to PC, likely because Her2/neu gene amplification and expression was rare. Tumor EGFR status significantly affected RR, PFS, and OS to the underlying regimen of PC. Sponsored by Bristol-Myers Squibb, Genentech, and Damon Runyon Cancer Research Foundation (MG).

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Obesity is associated with altered metabolic and reproductive activity in the mare: effects of metformin on insulin sensitivity and reproductive cyclicity

In mares, obesity is associated with continuous reproductive activity during the non-breeding season. To investigate the effect of obesity and associated alterations in metabolic parameters on the oestrous cycle, two related studies were conducted. In Experiment 1, obese (body condition score > 7) mares were fed ad libitum or were moderately feed restricted during the late summer and autumn months. Feed restriction did not alter the proportion of mares entering seasonal anoestrus. However, obese mares exhibited a significantly longer duration of the oestrous cycle, significant increases in circulating concentrations of leptin and insulin, and decreased insulin sensitivity and concentrations of thyroxine compared with feed-restricted mares throughout the experiment. Experiment 2 was designed to investigate the effects of administration of the insulin-sensitising drug metformin hydrochloride on insulin sensitivity and the characteristics of the oestrous cycle in obese mares. In a dose–response trial, metformin increased insulin sensitivity after 30 days following administration of 3 g day–1, but not 6 or 9 g day–1, compared with controls receiving vehicle only. However, there were no differences in insulin sensitivity or oestrous cycle characteristics between control and metformin-treated groups when the 3 g day–1 dose was tested for a longer period of 2 months. These results demonstrate that obesity is associated with aberrations in the oestrous cycle and perturbations in several markers of metabolic status. The results also indicate that metformin is not an effective long-term monotherapy for increasing insulin sensitivity in horses at the doses tested. Additional studies are needed to examine possible effects of increasing insulin sensitivity on reproductive activity in obese mares.

Development of a model for inducing transient insulin resistance in the mare: preliminary implications regarding the estrous cycle

Peripheral insulin resistance is the failure of proper cellular glucose uptake in response to insulin. Insulin resistance and hyperinsulinemia are associated with several disease states in the horse and reproductive function disturbances in humans, including polycystic ovarian syndrome. To test the hypothesis that insulin resistance (IR) and hyperinsulinemia disrupt the estrous cycle in mares, two experiments were conducted to first develop a model to induce IR and to then examine the effect of this model on the duration of the estrous cycle. In Exp. 1, a hyperinsulinemic-euglycemic clamp (HEC) procedure was performed on seven mares to determine insulin sensitivity before and immediately following infusion of a heparinized lipid solution. The HEC procedure was repeated 1 wk after lipid infusion. Mares developed IR following the lipid infusion (P < 0.05), and some individuals maintained IR for up to 1 wk. Mares also exhibited increased blood insulin both immediately following treatment and 1 wk later (P < 0.05). In Exp. 2, induction of insulin resistance by lipid solution was not accompanied by changes in circulating concentrations of luteinizing hormone, and duration of the luteal phase, compared with the duration of untreated luteal phases. Nonetheless, lipid infusion and the resultant insulin resistance were associated with an increased interovulatory period (P < 0.05), and peak concentrations of progesterone (P < 0.05) were higher during the treated vs. untreated luteal phases of the estrous cycle. The results from the preliminary study suggest that infusion of a lipid solution may induce transient insulin resistance and hyperinsulinemia. The resulting insulin resistance and hyperinsulinemia may modify characteristics of the estrous cycle, perhaps at the level of the ovary.

The functional assessment of cancer therapy–BRM (FACT–BRM): A new tool for the assessment of quality of life in patients treated with biologic response modifiers

PURPOSE

This paper reports on the development and validation of two biologic response modifier (BRM) subscales for use with the Functional Assessment of Cancer Therapy-General (FACT-G) quality of life (QOL) questionnaire.

METHODS

Using the FACT-G as a base, 17 additional questions related to symptoms common to interferon and retinoid therapy were developed. Data collected at baseline (n = 191) and week 2 (n = 168) in a randomized trial of interferon +/- 13-cis-retinoic acid in advanced renal cell carcinoma patients were used to validate this measure.

RESULTS

Using a combined empirical and conceptual approach, the 17 questions were reduced to 13 questions consisting of two subscales: 'BRM-physical' (7 items; baseline coefficient alpha(alpha) = 0.70; week-2 alpha = 0.75) and 'BRM-mental' (6 items; baseline alpha = 0.79; week-2 alpha = 0.78). Internal consistency of the trial outcome index (TOI) combining physical well-being, functional well-being and the BRM subscales, was 0.91 for baseline assessments and 0.92 for week 2. Discriminant validity was demonstrated for the TOI by its ability to differentiate among prognostic risk groups, and for the total FACT-G, TOI and total FACT-BRM scores by their ability to distinguish between groups differing in performance, response and toxicity status.

CONCLUSIONS

The 'BRM-physical' and 'BRM-mental' subscales can be combined with the FACT-G to form the 'FACT BRM' scale, useful for measuring QOL in cancer patients who are receiving treatment with biologic response modifiers.

Changes in median nerve somatosensory transmission and motor output following transient deafferentation of the radial nerve in humans

OBJECTIVE

To determine if transient anaesthetic deafferentation of the radial nerve would lead to alterations in processing of early somatosensory evoked potentials (SEPs) from the median nerve or alter cortico-motor output to the median nerve innervated abductor pollicis brevis (APB) muscle.

METHODS

Spinal, brainstem, and cortical SEPs to median nerve stimulation were recorded before, during and after ipsilateral radial nerve block with local anaesthesia. Motor evoked potentials (MEPs) and motor cortex output maps were recorded from the APB muscle.

RESULTS

There were no significant changes to most early SEP peaks. The N30 peak, however, showed a significant increase in amplitude, which remained elevated throughout the anaesthetic period, returning to baseline once the anaesthetic had completely worn off. MEP amplitude of the median nerve innervated APB muscle was significantly decreased during the radial nerve blockade. There was also a significant alteration in the APB optimal site location, and a small but significant decrease in the silent period during the radial nerve blockade.

CONCLUSIONS

Transient anaesthetic deafferentation of the radial nerve at the elbow leads to a rapid modulation of cortical processing of median nerve input and output. These changes suggest an overall decrease in motor cortex output to a median nerve innervated muscle not affected by the radial nerve block, occurring concomitantly with an increased amplitude of the median nerve generated N30 SEP peak, thought to represent processing in the supplementary motor area (SMA). Independent subcortical connections to the SMA are thought to contribute to the N30 response observed in this study. Unmasking of pre-existing but latent cortico-cortical and/or thalamo-cortical connections may be the mechanism underlying the cortical SEP increases observed following radial nerve deafferentation.

SIGNIFICANCE

Transient deafferentation of the radial nerve, which supplies wrist and hand extensor muscles, has been shown to alter sensory processing from and motor output to the median nerve innervated thenar muscles.

Rapid reversible changes to multiple levels of the human somatosensory system following the cessation of repetitive contractions: a somatosensory evoked potential study

OBJECTIVE

Numerous somatosensory evoked potential (SEP) studies have provided clear evidence that during repetitive voluntary movement, the transmission of somatosensory afferent information is attenuated. The objective of this work was to determine if this gating phenomenon could persist beyond the period of repetitive movement.

METHODS

We recorded spinal, brainstem, and cortical SEPs to median nerve stimulation before and immediately after a modified 20 min repetitive typing task that did not involve the thenar muscles.

RESULTS

There were significant decreases in pre-central cortical and subcortical SEP amplitudes for several minutes following task cessation.

CONCLUSIONS

These results demonstrate the persistence of the gating phenomenon beyond the cessation of the actual repetitive movement. They also indicate that plastic changes do occur in cortical and subcortical components of the somatosensory system, following voluntary repetitive contractions.

SIGNIFICANCE

The persistence of changes in somatosensory processing beyond the period of repetitive activity may be relevant to the initiation of overuse injuries.

Cytology of endolymphatic sac tumor

A 77-year-old man presented with decreased mental status and an enhancing partially cystic tumor along the left tentorium on magnetic resonance imaging after mastoidectomy and petrosectomy for an "auditory canal tumor." Smears of the aspirated cyst fluid revealed rare epithelial cell clusters, some with papillary features, foamy macrophages, and blood. The cells were orderly, with fairly bland nuclei and well-defined cell borders. The cell block contained similar epithelium, with cells containing eosinophilic and focally vacuolated cytoplasm, some with pigmented granules resembling hemosiderin. Numerous foam cells were also present. Review of the patient's previous and concurrent resection material showed an endolymphatic sac tumor, a rare neoplasm that arises in the endolymphatic sac in the temporal bone. The previously undescribed cytologic features of this rare neoplasm are discussed.