Cardiovascular sequel of neck irradiation in head and neck cancer patients.

PURPOSE: The baroreflex is an important afferent mechanism controlling autonomic functions. As afferent nerves course through the neck, they are susceptible to damage by neck irradiation in head and neck cancer patients. With increased survival of head and neck cancer patients because of improved therapy, the cardiovascular morbidity and mortality in them have become apparent and this is of clinical concern. There are few case reports of baroreflex failure as a chronic sequel to neck irradiation. OBJECTIVES: The present study evaluated the changes in cardio-autonomic tone and postural cardiovascular reflex in neck-irradiated patients. METHODS: Head and neck cancer patients who had received neck irradiation (n = 15) and healthy controls (n = 15) were evaluated for heart rate variability with time domain analysis of 5 min ECG recording. Postural cardiovascular reflexes were studied with changes in blood pressure and heart rate in the lying to standing test. RESULTS: Our results suggest that there is a reduction in overall time domain measures of heart rate variability and weakened postural reflexes in neck-irradiated patients. CONCLUSION: Decreased heart rate variability in neck-irradiated patients reflects an independent risk of cardiovascular morbidity. The early detection of cardiovascular impairment in such patients may help healthcare professionals in providing better care. Furthermore, the dose delivered to the carotid sinus should be monitored and restricted.

Circadian rhythm of serum cortisol in female patients with fibromyalgia syndrome.

Fibromyalgia syndrome (FMS) patients have disturbed sleep patterns which may lead to altered circadian rhythm in serum cortisol secretion. The aim of this study was to assess circadian changes, if any, in serum cortisol levels in female patients with FMS. Cortisol levels were estimated every 6 h during 24 h period; in 40 female patients satisfying ACR criteria for FMS (Age 36.4 ± 9.9), and 40 healthy females without FMS (Age 33.8 ± 11.1). A significant difference in the night time serum cortisol level was observed among the patients and control groups (patients, 12.9 ± 9.7 controls 5.8 ± 3.0; p < 0.01). However, no significant difference was found in serum cortisol levels in patients and control groups in the morning (patients, 28.4 ± 13.2 controls, 27.6 ± 14.5; p > 0.05), afternoon (patients, 14.4 ± 5.6 controls, 14.0 ± 6.6; p > 0.05) and evening hours (patients, 10.9 ± 5.8 controls, 8.9 ± 3.6; p > 0.05). It could be concluded that there is an abnormality in circadian secretion of cortisol in female FMS patients.

Immunoregulation of bone remodelling.

Remodeling, a continuous physiological process maintains the strength of the bones, which maintains a delicate balance between bone formation and resorption process. This review gives an insight to the complex interaction and correlation between the bone remodeling and the corresponding changes in host immunological environment and also summarises the most recent developments occuring in the understanding of this complex field. T cells, both directly and indirectly increase the expression of receptor activator of nuclear factor kB ligand (RANKL); a vital step in the activation of osteoclasts, thus positively regulates the osteoclastogenesis. Though various cytokines, chemikines, transcription factors and co-stimulatory molecules are shared by both skeletal and immune systems, but researches are being conducted to establish and analyse their role and / or control on this complex but vital process. The understanding of this part of research may open new horizons in the management of inflammatory and autoimmune diseases, resulting into bone loss and that of osteoporosis also.

Lack of Circadian Pattern of Serum TNF-α and IL-6 in Patients with Fibromyalgia Syndrome.

The present study was designed to test the hypothesis of a circadian variation in circulating levels of tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) in women with fibromyalgia syndrome (FMS). Serum levels of IL-6 and TNF-α were measured at 4 h intervals of the day in 50 women with FMS satisfying American College of Rheumatology criteria for FMS (age 36.68 ± 9.89) as well as 50 healthy control women (age 32.82 ± 10.53). Serum TNF-α levels were substantially increased in patients with FMS but showed no circadian variation. In contrast, no difference in the levels of IL-6 was found. Moreover, there was also no circadian variation in both the groups of patients and controls. We conclude that no circadian pattern exists in the circulating levels of serum IL-6 and TNF-α in patients with FMS, although TNF-α levels are found raised in patients with FMS.

Abnormality of circadian rhythm of serum melatonin and other biochemical parameters in fibromyalgia syndrome.

Fibromyalgia syndrome (FMS) is a complex chronic condition causing widespread pain and variety of other symptoms. It produces pain in the soft tissues located around joints throughout the body. FMS has unknown etiology and its pathophysiology is not fully understood. However, abnormality in circadian rhythm of hormonal profiles and cytokines has been observed in this disorder. Moreover, there are reports of deficiency of serotonin, melatonin, cortisol and cytokines in FMS patients, which are fully regulated by circadian rhythm. Melatonin, the primary hormone of the pineal gland regulates the body's circadian rhythm and normally its levels begin to rise in the mid-to-late evening, remain high for most of the night, and then decrease in the early morning. FMS patients have lower melatonin secretion during the hours of darkness than the healthy subjects. This may contribute to impaired sleep at night, fatigue during the day and changed pain perception. Studies have shown blunting of normal diurnal cortisol rhythm, with elevated evening serum cortisol level in patients with FMS. Thus, due to perturbed level of cortisol secretion several symptoms of FMS may occur. Moreover, disturbed cytokine levels have also been reported in FMS patients. Therefore, circadian rhythm can be an important factor in the pathophysiology, diagnosis and treatment of FMS. This article explores the circadian pattern of abnormalities in FMS patients, as this may help in better understanding the role of variation in symptoms of FMS and its possible relationship with circadian variations of melatonin, cortisol, cytokines and serotonin levels.

Variation in response to experimental pain across the menstrual cycle in women compared with one month respose in men.

Gender differences in pain perception have been reported in literature. However, most such studies have ignored the role of female sex hormones in influencing pain response across menstrual cycle (MC). In this study, we have investigated the variation in pain response on different days of the menstrual cycle. Ninety subjects (60 females) were subjected to experimental pain of cold pressor task, on days 1, 7, 14, and 21 of the MC (females), and on four consecutive Mondays of a month (males). Male subjects showed no variation in pain response. Females reported higher pain sensitivity on days 7 and 14 of MC. We suggest that experimental pain studies involving female menstruating subjects should be carried out only during a particular phase of the cycle, and this phase should be reported in literature to increase the reproducibility of the experiment.

Oral mucositis in morning vs. evening irradiated patients: a randomised prospective study.

PURPOSE: Patients of head and neck cancer undergoing radiotherapy develop oral mucositis. The severity of mucositis may also depend on the time of administration of radiation apart from patient-related factors. The most radiosensitive phase of the cell cycle (G2-M) occurs in the late afternoon and evening in human oral mucosa; therefore, it is more vulnerable to radiation injury in the evening. The present study evaluated prospectively the severity of acute oral mucositis in head and neck carcinoma patients irradiated in the morning (08:00-11:00 h) versus late afternoon/evening (15:00-18:00 h). METHOD: A total of 212 patients of head and neck carcinoma were randomised to morning (08:00-11:00 h) and evening (15:00-18:00 h) groups. The grades of oral mucosa ulceration were compared in the two groups. RESULTS: The grades of mucositis were marginally higher in the evening-irradiated group than in the morning-irradiated group 38% vs. 26% (p = 0.08). CONCLUSION: The observed incidence of grade III/IV mucositis in morning vs. evening irradiated patients may be because of the existence of circadian rhythm in the cell cycle of normal mucosa. This knowledge may provide a possibility of treating the patients with decreased toxicity to oral mucosa.

Effects of garlic (Allium sativum) extract on the heart rate, rhythm and force of contraction in frog: a dose-dependent study.

Garlic juice (dose equivalent to 3.3 g to 33 g garlic) mainly caused bradycardia in frog Rana tigerina. The disturbance in ventricular rhythm was observed prior to than that of atria. Rhythm was specially disturbed at higher doses causing bizarre pattern. Force of contraction of the heart also decreased with higher dose of the garlic extract. The results suggest that garlic extract has some beneficial effect on heart rate modulating the rate, rhythm and force of contraction positively but very high doses may exert non-desirable effects as well.