Ultrastructural detection of nitric oxide in human nasal mucosa

Betulinic acid‑induced expression of nicotinamide adenine dinucleotide phosphate‑diaphorase in the immune organs of mice: A possible role of nitric oxide in immunomodulation

The aim of the present study was to investigate the effects of betulinic acid (BetA) on the expression and distribution pattern of nicotinamide adenine dinucleotide phosphate diaphorase (NADPH‑d), an indirect indicator of nitric oxide (NO) synthase in the thymus and spleen of mice. Mice were randomly assigned to four main groups (n=48 per group): Experimental group (BetA), positive control group (goniothalamin), vehicle control group (dimethyl sulfoxide) and control group (without vehicle). Each group was further divided into three equal subgroups according to the treatment length (4, 8 and 12 days). BetA treatment induced the expression of NADPH‑d activity in the thymus and spleen without any significant changes in the morphology of the organs. Furthermore, the expression pattern of NADPH‑d in BetA‑treated animals was significantly increased compared with that in the control animals. NADPH‑d expression in the thymus and spleen suggests that NO signaling may be a potential mechanism underlying the BetA‑induced immunomodulation in these organs. These findings are of direct clinical relevance and may contribute to the further development of BetA as a therapeutic drug.

Recent advances in research on nitrergic nerve-mediated vasodilatation

Cerebral vascular resistance and blood flow were widely considered to be regulated solely by tonic innervation of vasoconstrictor adrenergic nerves. However, pieces of evidence suggesting that parasympathetic nitrergic nerve activation elicits vasodilatation in dog and monkey cerebral arteries were found in 1990. Nitric oxide (NO) as a neurotransmitter liberated from parasympathetic postganglionic neurons decreases cerebral vascular tone and resistance and increases cerebral blood flow, which overcome vasoconstrictor responses to norepinephrine liberated from adrenergic nerves. Functional roles of nitrergic vasodilator nerves are found also in peripheral vasculature, including pulmonary, renal, mesenteric, hepatic, ocular, uterine, nasal, skeletal muscle, and cutaneous arteries and veins; however, adrenergic nerve-induced vasoconstriction is evidently greater than nitrergic vasodilatation in these vasculatures. In coronary arteries, neurogenic NO-mediated vasodilatation is not clearly noted; however, vasodilatation is induced by norepinephrine released from adrenergic nerves that activates β1-adrenoceptors. Impaired actions of NO liberated from the endothelium and nitrergic neurons are suggested to participate in cerebral hypoperfusion, leading to brain dysfunction, like that in Alzheimer's disease. Nitrergic neural dysfunction participates in impaired circulation in peripheral organs and tissues and also in systemic blood pressure increase. NO and vasodilator peptides, as sensory neuromediators, are involved in neurogenic vasodilatation in the skin. Functioning of nitrergic vasodilator nerves is evidenced not only in a variety of mammals, including humans and monkeys, but also in non-mammals. The present review article includes recent advances in research on the functional importance of nitrergic nerves concerning the control of cerebral blood flow, as well as other regions, and vascular resistance. Although information is still insufficient, the nitrergic nerve histology and function in vasculatures of non-mammals are also summarized.

Nitric oxide metabolites in allergic rhinitis: The effect of pollen allergen exposure

BACKGROUND

Seasonal allergic rhinitis (SAR) is characterised by an inflammation consequent to allergen exposure. Nitric oxide may be involved in allergic inflammation.

OBJECTIVE

This study evaluated the serum nitrite concentrations in SAR patients during and outside pollen exposure in order to estimate activity of nitric oxide synthases.

METHODS

One hundred and two (56 females, 46 males, median age: 28.7 years) were included in this study: 56 with SAR evaluated outside the pollen season and so without allergic inflammation and symptoms, and 46 with SAR evaluated during the pollen season with symptoms. Serum concentrations of nitrite were measured and in those patients exposed to pollens, results were compared to scores of the Visual Analogue Scale for nasal obstruction perception.

RESULTS

Serum nitrite concentrations were higher in SAR patients evaluated outside the pollen season (U=-6.78; p<0.0001), moreover, there was a significant relationship between nasal obstruction perception and nitrite in patients evaluated during the pollen season.

CONCLUSION

This preliminary study demonstrates that serum nitric oxide metabolism depends on allergen exposure.

Serum Nitrite/Nitrate and Arginase Levels in Patients with Allergic Rhinitis

Nitric oxide (NO) plays an important role in the regulation of upper respiratory function. Patients with untreated allergic rhinitis (AR) have an increased level of NO in the nasal cavity compared to normal individuals. We aimed to investigate serum levels of arginase and NO metabolites nitrite/nitrate in patients with AR during the symptomatic period. The patient and control groups consisted of 14 males and 12 females (mean age: 29, range: 20-40 years), and 10 males and 10 females (mean age: 27, range: 22-38 years), respectively. Nitrite/nitrate levels were 0.98 +/- 0.33 ng/ml in the patients with AR, and 0.78 +/- 0.26 ng/ml in the control group (p = 0.03). Arginase levels were 28.8 +/- 14.1 ng/ml in the patients with AR, and 20.8 +/- 13.5 ng/ml in the control group. The difference between the groups was statistically insignificant (p = 0.24). Our results support the view that NO plays an important role in the pathogenesis of AR, and NO metabolites may be used as a marker for monitoring the disease activity and therapy.

Bibliography. Current world literature. Nose and paranasal sinuses

PURPOSE OF REVIEW

Patients with advanced head and neck cancer are being treated with chemo-radiotherapy, and life is being prolonged, with or without persistent disease, for longer than was previously. Hypercalcaemia may present in patients with advanced or disseminated head and neck cancer, and, as such, these patients may present to a larger variety of clinicians for advice concerning their symptoms and illness. Modes of presentation of hypercalcaemia and treatment strategies are reviewed.

RECENT FINDINGS

There were previously few large series of head and neck cancer patients diagnosed with hypercalcaemia, which may or may not have been related to their cancer being treated. Investigations, by way of blood/serum calcium level, may identify such patients. Patients with cancer-related hypercalcaemia have a poor prognosis, but many may respond temporarily to treatment when offered, with an improvement of their quality of life and death.

SUMMARY

Hypercalcaemia should and must be considered in all patients who have or possibly have a diagnosis of a head and neck cancer and who present unwell with symptoms of fatigue, lethargy and somnolence. Investigation must include serum calcium (corrected for serum albumin binding) and parathyroid hormone level. Patients may be treated by a combination of rehydration and bisulphonate therapy until the serum calcium is reduced to a level below 3 mmol/l. The majority of patients diagnosed with hypercalcaemia due to head and neck malignancy die of their diseases in the short term, but some may enjoy a prolongation of life with reasonable quality if diagnosed and treated aggressively.