Search PubMed⌕ Search

Biomedical subjects

A Anggård

Publications and source records attributed to A Anggård.

At least 73 records · Page 4Linked to original sources

Results of the treatment of achalasia by pneumatic dilatation.

Thirty-three patients treated at the Karolinska Hospital for achalasia of the esophagus during the period 1968--78 have been reexamined. Twenty-eight of these patients underwent pneumatic dilatation. Excellent and good results were obtained in 79% of cases; in 21% the result was considered poor. In 2 cases the esophagus was perforated during dilatation--a perforation rate of 5% of the total number of dilatations. In 6 cases the lower sphincteric pressure was calculated before and after dilatation. It was found to be higher than normal, preoperatively, but reduced to a near-normal value postoperatively.

Adolescent↗

Vasomotor rhinitis--pathophysiological aspects.

Vasomotor rhinitis is commonly defined as an unspecific hyperractivity of the nasal mucosa. The symptoms might be due to increased parasympathetic activity to the nose with the release of vaso-secretory active substances. Experimental data from the cat suggest that the postganglionic parasympathetic mediator of nasal secretion is cholinergic, whereas the vascular responses appears to be due to a different mechanism. Apart from a rich sympathetic and parasympathetic innervation of the nasal mucosa there are other nerve fibres containing substance-P (SP) and vasoactive intestinal polypeptide (VIP). The secreto-vasomotor responses can be influenced by activation of these fibres and the atropine resistant vasodilatation seen following Vidian nerve stimulation thus may partly be due to activation and release of SP and VIP. Furthermore, other vasoactive substances released such as e.g. SRS or Kallikrein may participate in these reactions.

Animals↗

Parasympathetic control of blood circulation and secretion in the nasal mucosa.

The effects of selective parasympathetic nerve activation on the secretory response and the vascular exchange and capacitance sections in the cat nasal mucosa were studied. The vascular events were investigated by measuring the local disappearnce of 125I- and changes in gross pulse rate from 131I- labelled serum albumin as monitored over the nose. A frequency-dependent increase in nasal secretion and local blood content occurred in the range 0.5-12 imp/sec: an increase in disappearance rate was observed at the same time. This indicates that the vascular and secretory responses are activated simultaneously. The secretory responses, but not the vascular events, were shown to be blocked by atropine. The results thus shown that the postganglionic parasympathetic mediator of nasal secretion is cholinergic, whereas the vasodilatation appears to be due to a different mechanism, which is not sensitieve to atropine. The beneficial effect of some antihistamines in vasomotor rhinitis may thus be due to their anticholinergic properties.

Animals↗

Co-existence of peptide HI (PHI) and VIP in nerves regulating blood flow and bronchial smooth muscle tone in various mammals including man.

By immunohistochemistry it was found that PHI- and VIP-like immunoreactivity (-IR) occurred in the same autonomic neurons in the upper respiratory tract, tongue and salivary glands with associated ganglia in rat, guinea-pig, cat, pig and man. VIP- and PHI-like immunoreactivity was also found in similar locations in the human heart. The N-terminally directed, but not the C-terminally directed, PHI antiserum or the VIP antiserum stained endocrine cells in the pig duodenum. This suggests the existence of an additional PHI-like peptide. Ligation of nerves acutely caused marked overlapping axonal accumulations of PHI- and VIP-IR central to the lesion. Two weeks after transection of the nerves, both types of immunoreactivities were still observed in accumulations both in the axons as well as in the corresponding cell bodies. The levels of PHI- and VIP-IR in normal tissues from the cat were around 10-50 pmol/g with a molar ratio of about 1 to 2. Systemic administrations of PHI and VIP induced hypotension, probably due to peripheral vasodilation in both guinea-pig and cat. Furthermore, both PHI and VIP caused an inhibition of the vagally induced increase in respiratory insufflation pressure in guinea-pig. PHI and VIP relaxed the guinea-pig trachea in vitro, suggesting a direct action on tracheobronchial smooth muscle. VIP was about 5-10 times more potent than PHI with regard to hypotensive effects and 2-3-fold, considering respiratory smooth muscle-relaxant effects in the guinea-pig. PHI was about 50-fold less potent to induce hypotension in the cat than in the guinea-pig. Although species differences seem to exist as regards biological potency, PHI should also be considered when examining the role of VIP as an autonomic neurotransmitter.

Animals↗

Increased vascular permeability in rat nasal mucosa induced by substance P and stimulation of capsaicin-sensitive trigeminal neurons.

Electrical stimulation of the maxillary branches of the trigeminal nerve induced an increase in vascular permeability to macromolecules and an interstitial edema in the nasal mucosa of the rat, as indicated by extravasation of Evans blue. In animals that had been treated neonatally with capsaicin, the effect of trigeminal nerve stimulation was abolished. Local application of capsaicin or substance P (SP) also induced a significant Evans blue extravasation in the nasal mucosa. In capsaicin-pretreated animals the effect of SP was still present, while the permeability increase induced by capsaicin was abolished. In conclusion, chemogenic irritation of the nasal mucosa by capsaicin induces edema probably via a local axon reflex inducing release of SP. Capsaicin-sensitive SP-containing afferents in the nasal mucosa may also be involved in the pathogenesis of nasal congestion seen in various types of rhinitis.

Animals↗

Origin and distribution of capsaicin-sensitive substance P-immunoreactive nerves in the nasal mucosa.

In immunohistochemical studies, substance P-immunoreactivity (SP-IR) was found in a population of trigeminal ganglion cells in guinea pig, rat and cat. SP-IR nerve endings were found in the spinal trigeminal nucleus, around sphenopalatine ganglion cells, around blood vessels, as well as under and within the epithelium of the nasal mucosa. Ligation and denervation experiments in the cat indicated that the SP-IR nerves in the sphenopalatine ganglion and the nasal mucosa are of trigeminal origin. Capsaicin pretreatment of guinea pigs and rats resulted in a selective loss of the SP-IR nerves in the nasal mucosa and sphenopalatine ganglion, while the parasympathetic and sympathetic nerves were still present.

Animals↗

Effects of nasal capsaicin pretreatment and cryosurgery on sneezing reflexes, neurogenic plasma extravasation, sensory and sympathetic neurons.

Local and systemic capsaicin pretreatment as well cryosurgery induced a long-lasting loss of sensory substance P-immunoreactive nerves in the guinea-pig nasal mucosa. In addition, cryosurgery caused a loss of noradrenergic sympathetic nerves, sclerosis of blood vessels, epithelial damage and fibrosis of the mucosa. The sneezing response to local application of capsaicin--but not that to nicotine--was reduced or abolished by capsaicin pretreatment and cryosurgery, while the response to tactile stimulation was unaffected. These effects were long-lasting and still present 2 months after treatment. Local capsaicin pretreatment of the nasal mucosa had no effects on the substance P levels or the Evans Blue extravasation response to i.v. capsaicin in the ureter, indicating that this treatment has no systemic effects on other afferent SP-neurons. It is suggested that local capsaicin pretreatment is a more selective and less traumatic method than cryosurgery to induce a long-lasting desensitization of the nasal mucosa to chemical irritants in hyperreactive disorders of the nose.

Animals↗