Peroneus brevis tear caused by an impingement between hypertrophied peroneal tubercle and lateral malleolus.

We report a 15-year-old female patient who sustained peroneus brevis injury caused by an impingement between the hypertrophied peroneal tubercle and lateral malleolus. The patient had pain for 3 years in the lateral side of her left ankle with unsuccessful conservative treatment. The oblique sagittal images of 3-dimensional magnetic resonance imaging and ultrasonography were useful in depicting the peroneus brevis injury and identifying the location of impingement between the hypertrophied peroneal tubercle and the tip of the lateral malleolus. The flatfoot deformity of the patient further aggravated the impingement. The patient was treated surgically, with excision of the enlarged tubercle and tendon repair. The ankle pain resolved 12 months postoperatively. Although rare, clinicians should recognize this condition as the cause of lateral ankle pain.

Circadian rhythm in negative affect: Implications for mood disorders.

In humans, there is an endogenous, near 24-h (i.e., circadian) variation in mood with the best mood occurring during the circadian day and the worst mood occurring during the circadian night. Only positive affect, and not negative affect, has been shown to contribute to this circadian rhythm. We discovered a sharp circadian peak in negative affect during the circadian night coincident with a circadian trough in positive affect. These findings may help explain the association of depression with insomnia, the increased risk of suicide with nocturnal wakefulness, and the correlation between circadian misalignment and symptom severity in Major Depressive Disorder.

Effect of intact oxaliplatin in plasma on a cold allodynia after multiple administrations in colorectal cancer model rats.

BACKGROUND: Oxaliplatin (L-OHP)-induced acute neuropathy is a major factor for influencing treatment compliance in patients receiving chemotherapy for colorectal cancer (CRC). Acute neuropathy is caused by the intact L-OHP affecting the function of transient receptor potential vanilloid 1 (TRPV1) channel. In this study, the effectiveness of the detection of the intact L-OHP and the association with the severity of L-OHP-induced acute neuropathy were investigated using a rat model of CRC. METHODS: Wistar male rats were prepared as models of CRC by using 1,2-dimethylhydrazine (DMH) and dextran sulfate. Intravenous L-OHP was administered (weekly) to CRC rats for 4 weeks, at doses of 3, 5, or 8 mg/kg, respectively. Pharmacokinetic and tumor distribution profiles of animals with intact L-OHP were observed on days 1 and 22. Cold allodynia was determined as a read-out of acute neuropathy using the acetone test over the 4 weeks. RESULTS: The mean AUC0-∞ values for the intact L-OHP were increased dose-dependently at the three doses. The accumulation of intact L-OHP was confirmed following an increase in L-OHP concentration on day 22. Acute neuropathy was observed from day 2 at all doses and the withdrawal response correlated with AUC (R2 =0.9816). CONCLUSIONS: To prevent the onset of L-OHP-induced acute neuropathy, the timely detection of the intact L-OHP is important. These findings could be a basis of the establishment a pharmacokinetic and toxicodynamic model to aid the planning of therapy cycle completion for CRC.

Effects of obstructive sleep apnea on endogenous circadian rhythms assessed during relaxed wakefulness; an exploratory analysis.

Obstructive sleep apnea (OSA) is associated with hypertension, cardiovascular disease, and a change in the 24 h pattern of adverse cardiovascular events and mortality. Adverse cardiovascular events occur more frequently in the middle of the night in people with OSA, earlier than the morning prevalence of these events in the general population. It is unknown if these changes are associated with a change in the underlying circadian rhythms, independent of behaviors such as sleep, physical activity, and meal intake. In this exploratory analysis, we studied the endogenous circadian rhythms of blood pressure, heart rate, melatonin and cortisol in 11 participants (48 ± 4 years; seven with OSA) throughout a 5 day study that was originally designed to examine circadian characteristics of obstructive apnea events. After a baseline night, participants completed 10 recurring 5 h 20 min behavioral cycles divided evenly into standardized sleep and wake periods. Blood pressure and heart rate were recorded in a relaxed semirecumbent posture 15 minutes after each scheduled wake time. Salivary melatonin and cortisol concentrations were measured at 1-1.5 h intervals during wakefulness. Mixed-model cosinor analyses were performed to determine the rhythmicity of all variables with respect to external time and separately to circadian phases (aligned to the dim light melatonin onset, DLMO). The circadian rhythm of blood pressure peaked much later in OSA compared to control participants (group × circadian phase, p < .05); there was also a trend toward a slightly delayed cortisol rhythm in the OSA group. Rhythms of heart rate and melatonin did not differ between the groups. In this exploratory analysis, OSA appears to be associated with a phase change (relative to DLMO) in the endogenous circadian rhythm of blood pressure during relaxed wakefulness, independent of common daily behaviors.

The Circadian System Contributes to Apnea Lengthening across the Night in Obstructive Sleep Apnea.

STUDY OBJECTIVE: To test the hypothesis that respiratory event duration exhibits an endogenous circadian rhythm. DESIGN: Within-subject and between-subjects. SETTINGS: Inpatient intensive physiologic monitoring unit at the Brigham and Women's Hospital. PARTICIPANTS: Seven subjects with moderate/severe sleep apnea and four controls, age 48 (SD = 12) years, 7 males. INTERVENTIONS: Subjects completed a 5-day inpatient protocol in dim light. Polysomnography was recorded during an initial control 8-h night scheduled at the usual sleep time, then through 10 recurrent cycles of 2 h 40 min sleep and 2 h 40 min wake evenly distributed across all circadian phases, and finally during another 8-h control sleep period. MEASUREMENTS AND RESULTS: Event durations, desaturations, and apnea-hypopnea index for each sleep opportunity were assessed according to circadian phase (derived from salivary melatonin), time into sleep, and sleep stage. Average respiratory event durations in NREM sleep significantly lengthened across both control nights (21.9 to 28.2 sec and 23.7 to 30.2 sec, respectively). During the circadian protocol, event duration in NREM increased across the circadian phases that corresponded to the usual sleep period, accounting for > 50% of the increase across normal 8-h control nights. AHI and desaturations were also rhythmic: AHI was highest in the biological day while desaturations were greatest in the biological night. CONCLUSIONS: The endogenous circadian system plays an important role in the prolongation of respiratory events across the night, and might provide a novel therapeutic target for modulating sleep apnea.