Search PubMed⌕ Search

Biomedical subjects

S Lindberg

Publications and source records attributed to S Lindberg.

89 records · Page 5Linked to original sources
PubMed1976

Autonomous hyperparathyroidism: a possible late complication of neck radiotherapy.

In a series of 170 patients operated on for autonomous hyperparathyroidism (HPT) during a four-year period ending 1974, 24 patients (14%) had, earlier in life, received radiation therapy to the neck region for various benign conditions. Treatment records were traced in 19 cases. The estimates of absorbed dose in the parathyroids ranged from 200 to 3 000 rad. Eighteen patients had their first course of treatment in childhood or early adult life. The diagnosis of HPT was established in these patients 42 years (average) after exposure to radiation. Six patients who were irradiated after the age of 48 had an average time lapse of 12 years before the diagnosis of HPT was made. The occurrence of signs and symptoms related to HPT was similar in exposed and non-exposed patients. The high incidence of previous neck radiotherapy in our series suggests that radiation may be a contributory factor in the development of HPT.

Adult↗
PubMed1975

Tissue distribution of N-14-C-azure C (methylthionine) in the rat.

The distribution of radioactivity as 5-, 10-, and 15-min intervals following the intravenous administration of N-14-C-azure C was determined. The concentrations of radioactivity observed indicated that radioactive derivatives of azure C would not be useful pancreas of parathyroid scanning agents.

Animals↗
PubMedDate not supplied

Mucociliary activity and the diving reflex.

It has previously been shown that mucociliary activity in the rabbit maxillary sinus is immediately increased after short-term exposure to such airway irritants as cigarette smoke and ammonia vapor. This increase is mediated through the stimulation of capsaicin-sensitive nerve endings. Besides producing the mucociliary effect, these irritants inhibit breathing, a response characteristic of the diving reflex in mammals. Whether an increase in mucociliary activity is part of the diving reflex was investigated by injecting 0.5 mL water into the nasopharynges of anesthetized rabbits. Mucociliary and respiratory responses were compared with the effects of mechanical stimulation (ie, rotating an intranasal catheter until sneezing occurred). Water challenge produced an increase in mucociliary activity of 21.6% +/- 2.4%, a response that began approximately 10 seconds after injection. Mucociliary acceleration was completely blocked by atropine, indicating a cholinergic mechanism, but was unaffected by pretreatment with capsaicin. The respiration rate was inhibited by about 45% after challenge with water. Pretreatment with atropine and capsaicin had no effect on this reduced respiratory rate. Mechanical stimulation of the nasal mucosa accelerated mucociliary activity. This response appeared approximately 4 seconds after stimulation was begun, and occurred simultaneously with the onset of sneezing. The peak increase was 22.0% +/- 2.1%. Sneezing was followed by an increase in the respiration rate of about 40%. Pretreatment with atropine or capsaicin had no effect on respiratory responses, but did inhibit mucociliary acceleration, suggesting that the response is mediated through cholinergic effector neurons after activation of capsaicin-sensitive nerve endings.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMedDate not supplied

Effects of neuropeptides on mucociliary activity.

The effects of four neuropeptides, vasoactive intestinal polypeptide, enkephalin, bombesin, and substance P, on mucociliary activity in the rabbit maxillary sinus were investigated in vivo. The peptides were administered via the feeding artery (arteria maxillaris), and the resulting effects were registered with a noninvasive photoelectric technique. The peptides were tested in the dose range 0.0001 to 10 micrograms/kg body weight. The following results were observed: 1) vasoactive intestinal polypeptide and enkephalin did not influence mucociliary activity; 2) bombesin had only a slight accelerating effect on the mucociliary activity at doses of 0.1 to 10 micrograms/kg; and 3) substance P markedly accelerated the mucociliary activity in a dose-dependent manner in the dose range 0.01 to 10 micrograms/kg, the maximal increase being about 50%. The effect of substance P was atropine-resistant, and probably acted directly on the mucosa.

Animals↗
PubMedDate not supplied

Bradykinin accelerates mucociliary activity in rabbit maxillary sinus.

The in vivo effect of bradykinin on mucociliary (m.c.) activity in the rabbit maxillary sinus was investigated by administering the substance (0.01-10.0 micrograms/kg) via arteria maxillaris and recording the responses with a non-invasive photoelectric technique. Bradykinin accelerated the m.c. activity in a dose-dependent manner in the dose range 0.05-10.0 micrograms/kg. While the action of bradykinin was resistant to pretreatment with indomethacin 10.0 mg/kg, it was considerably weakened by the substance P antagonist [D-Pro2, D-Trp7,9]SP 1 mg/kg. The initial effect of bradykinin was also suppressed by atropine, suggesting that bradykinin accelerates m.c. activity by a dual mechanism comprising both SP and acetylcholine. Bradykinin probably stimulates a reflex arc in the airways involving afferent SP neurons and efferent post-ganglionic parasympathetic neurons.

Animals↗
PubMedDate not supplied

Antidromic nerve stimulation accelerates mucociliary activity in rabbit maxillary sinus.

The neuropeptide substance P (SP) is released from unmyelinated C-fibres in sensory nerves by antidromic nerve stimulation. In order to study the effect on mucociliary (m.c.) activity, the isolated distal end of the maxillary nerve was stimulated electrically (8 V, pulse rate 10 Hz, 5 ms pulses) 2-4 min, while the m.c. wave frequency in the maxillary sinus was recorded by a photoelectric technique. The m.c. wave frequency increased during stimulation by 35.4 +/- 4.9% (range 22.0-62.2%). Following pretreatment with atropine the m.c. activity increased by only 20.0 +/- 1.3% (range 14.9-21.9%) indicating that part of the response was mediated via stimulation of muscarinic receptors. The cholinergic part of the response is presumably secondary to release of SP since the SP antagonist [D-Pro2, D-Trp7,9]SP abolished the effect of nerve stimulation. Sympathetic ganglionectomy did not influence the response to antidromic nerve stimulation. It is concluded that antidromic stimulation of the maxillary nerve accelerates m.c. activity through a dual mechanism, involving release of SP, or SP-like peptides, from sensory C-fibre nerve endings as well as release of acetylcholine.

Animals↗
PubMedDate not supplied

The morphological basis for the effect of substance P on mucociliary activity in rabbit maxillary sinus.

The mucociliary (m.c.) activity in rabbit maxillary sinus is accelerated by the neuropeptide substance P (SP). The morphological basis for this mechanism was investigated by immunocytochemistry using monoclonal antibodies directed against SP. SP-like immunoreactivity was found in nerve fibres in the subepithelial layer of the sinus mucosa, in the maxillary nerve, and in nerve endings close to nerve cell bodies in the sphenopalatine ganglion. Thus, there is morphological evidence in the rabbit that SP plays a role in the regulation of m.c. activity. The results also support the view that the rabbit maxillary sinus is a suitable experimental model for studying SP effects in the airway mucosa.

Animals↗
PubMedDate not supplied

Nasal exposure to airway irritants triggers a mucociliary defence reflex in the rabbit maxillary sinus.

The effect on mucociliary (m.c.) activity in the rabbit maxillary sinus of cigarette smoke and ammonia (NH3) vapour delivered through a tracheal cannula or as nasal challenges was investigated by a photo-electric technique, and compared with simultaneously induced changes in the respiratory rate. Neither irritant had any effect on m.c. activity in the sinus after tracheo-bronchial exposure. However, the respiration rate was increased by NH3 vapour (2.5 ml, diluted 1:1 with room air) and neat cigarette smoke (10 ml) by 76.9% and 24.3% respectively (median values). In contrast, nasal challenges with both irritants increased m.c. activity by 24.1% (NH3) and 19.1% (cigarette smoke), and reduced the respiration rate by 31.0% (NH3) and 28.4% (cigarette smoke) (median values). NH3 vapour sometimes produced an apnea proper. Identical results were obtained in laryngectomized rabbits, indicating that laryngeal afferents were not involved in the responses. Moreover, topical application of the C-fibre stimulant capsaicin mimicked the effects produced by the airway irritants. It is concluded that nasal exposure to irritants triggers at least two different protective reflexes. One is the increase of m.c. activity in the upper airways involving sensory C-fibres and the other the apneic reflex of Kratschmer.

Ammonia↗
PubMedDate not supplied

Relations between blood flow and mucociliary activity in the rabbit maxillary sinus.

The effects of two sympathomimetic drugs on mucociliary activity and mucosal blood flow in the rabbit maxillary sinus were investigated by using a photo-electric technique (mucociliary activity) and laser Doppler flowmetry (blood flow). The responses produced were compared with effects of ligation of the external carotid artery. The alpha 1-agonist phenylpropanolamine (0.1-100 micrograms/kg) had no effect on the mucociliary activity, whereas the blood flow was reduced by 33.8 +/- 8.9% (mean +/- SE) when the dose was 100 micrograms/kg. The alpha 2-agonist xylometazoline (0.01-10.0 micrograms/kg) reduced mucociliary wave frequency by 21.6 +/- 4.6% (mean +/- SE) (maximum) for the dose 10 micrograms/kg. The blood flow was reduced by xylometazoline in the interval 1.0 to 10.0 micrograms/kg, with a maximum decrease of 65.8 +/- 2.6% (mean +/- SE) for the dose of 10 micrograms/kg. Ligature of the external carotid artery reduced blood flow by 76.0 +/- 4.6% (mean +/- SE), but did not significantly influence the mucociliary wave frequency. It is concluded that the decrease in mucociliary activity induced by alpha 2-adrenoceptor agonists is not due to a reduced blood flow.

Adrenergic alpha-Agonists↗
PubMedDate not supplied

The effects of prostaglandins E1, E2 and F2 alpha on mucociliary activity in the rabbit maxillary sinus.

The in vivo effects of prostaglandins E1, E2 and F2 alpha on mucociliary activity in the rabbit maxillary sinus were investigated using a photoelectric technique. Prostaglandins E1 and F2 alpha both accelerated the mucociliary wave frequency in a dose-dependent fashion. For prostaglandin E1 the maximum increase was 17.4 +/- 2.6% (0.1 micrograms/kg), for prostaglandin F2 alpha it was 24.1 +/- 3.0% (10 micrograms/kg). The effects of prostaglandin E2 was inconsistent. Although some doses stimulated mucociliary activity, the effects were not reproducible. Inhibition of phosphodiesterase with theophylline did not alter the response to exogenous prostaglandin E1, nor did inhibition of endogenous prostaglandin synthesis with indomethacin affect the basal mucociliary activity or the response to exogenous prostaglandin E1. The present findings suggest that the tested prostaglandins are of minor importance for regulating mucociliary function in the rabbit maxillary sinus.

Alprostadil↗
PubMedDate not supplied

Cholinergic and C-fibre mediated mechanisms in the stimulation of mucociliary activity induced by prostaglandins and histamine.

The involvement of cholinergic and C-fibre mediated mechanisms in the stimulation of mucociliary activity induced by prostaglandins and histamine was investigated in vivo in the rabbit maxillary sinus with a photoelectric technique. The prostaglandins E, (PGE,) and F2(2) alpha (PGF2 alpha) in dose of 0.1 microgram/kg and 10 micrograms/kg respectively stimulated the mucociliary activity in a biphasic fashion, with a small initial response during the first 1-2 min and a later maximum response after 3-4 min. These effects were resistant to atropine and to the SP antagonist (D-Pro2, D-Trp7,9)SP. The small initial response was blocked by pretreatment with high doses of capsaicin (13 mg i.a.), while the maximum response was unaffected. This indicates that the mucociliary responses induced by PGE, and PGF2 alpha involve capsaicin-sensitive C-fibres but that neither acetylcholine nor substance P were responsible. Histamine (50 micrograms/kg) stimulated mucociliary activity in the rabbit maxillary sinus and the effect was abolished by pretreatment with high doses of capsaicin and reduced by the SP antagonist (D-Pro2, D-Trp7,9)SP. This indicates that the histamine-induced stimulation of mucociliary activity involves capsaicin-sensitive C-fibres and that the effect might be mediated by substance P.

Alprostadil↗
PubMedDate not supplied

The influence of leukotrienes and platelet activating factor on mucociliary activity in the rabbit maxillary sinus.

Inflammatory mediators released in the airways during allergic reactions can affect the mucociliary system. Leukotrienes and platelet activating factor have been shown to affect the mucociliary activity in various cell preparations. The in vivo effects of these inflammatory mediators on mucociliary activity in rabbit maxillary sinus were investigated using a photoelectric technique. Leukotrienes C4 and D4 in the dose range 0.01-10.0 nmol/kg did not alter mucociliary activity significantly, either when given as bolus injections or as intraarterial infusions. Platelet activating factor had no effect in the dose range 0.001-0.1 nmol/kg. A dose of 1.0 nmol/kg increased mucociliary activity by 20.2 +/- 5.5% but produced adverse respiratory and circulatory effects at the same time. It is concluded that the inflammatory mediators leukotrienes C4, D4 and platelet activating factor have no essential regulatory influence on mucociliary activity in the upper airways of the rabbit.

Animals↗
PubMedDate not supplied

Reflex-induced acceleration of mucociliary activity in rabbit after exposure to cigarette smoke.

Short-term exposure to cigarette smoke is known to accelerate mucociliary (m.c.) activity in the rabbit maxillary sinus and to increase m.c. clearance from the lung. Several components of cigarette smoke stimulate sensory C-fibre endings in the airways. Some of these fibres contain the neuropeptide substance P (SP), and release of SP after stimulation of C-fibre endings is thought to accelerate m.c. activity. The purpose of the present investigation was to study possible mechanisms responsible for the increase of m.c. activity in the rabbit maxillary sinus after exposure to cigarette smoke. When delivered once a minute, 2.5 ml smoke puffs each accelerated the m.c. activity, the maximal increase being 34.7 +/- 2.4%, with a latency of 3.7 +/- 0.5 s. The response to cigarette smoke was suppressed in rabbits pretreated with atropine, an SP antagonist [(D-Pro2, D-Trp7,9)SP], capsaicin or hexamethonium. A response, albeit reduced, elicited in atropinized rabbits indicated a non-cholinergic component. The atropine-resistant acceleration was abolished by the SP antagonist. Together the results suggest that cigarette smoke accelerates m.c. activity through a reflex involving sensory SP containing C-fibres (afferent pathway) and cholinergic (probably parasympathetic) effector neurones (efferent pathway). Hence, the effect of cigarette smoke on the m.c. system reflects the joint release of both SP and acetylcholine. This dual mechanism may be of importance in the regulation of m.c. activity.

Acetylcholine↗
PubMedDate not supplied

Patient exposure when using 99Tcm-DTPA for evaluation of cerebrospinal fluid shunt patency.

The absorbed dose from 99Tcm-DTPA was estimated from 12 investigations in 9 patients who were evaluated for the patency of ventriculo-peritoneal shunts. The distribution of 99Tcm-DTPA in the ventricles, urinary bladder and peritoneal cavity was determined in regions of interest from repeated static gamma camera images. The effective dose equivalent was calculated to be less than 0.10 mSv for an injected activity of 15 MBq.

Cerebrospinal Fluid Shunts↗
PubMedDate not supplied

Need for thyroxine in patients lobectomised for benign thyroid disease as assessed by follow-up on average fifteen years after surgery.

Thyroid lobectomy is a common procedure. It is therefore important to know whether lobectomised patients need thyroxine substitution after operation for benign disease. A follow-up examination of 95 patients on average 15 years after surgery disclosed hypothyroidism in 5%. There were seven individuals (9%) with only elevated thyrotropin values but normal thyroxine values or only borderline thyroxine values. The completeness of the lobectomy was checked by means of technetium scintigrams. Patients on thyroxine treatment were investigated twice, the second time after discontinuing thyroxine for at least six weeks. There were no goiter recurrences indicating reoperation. No patient who had been operated on for a follicular adenoma had signs of malignant conversion or follicular recurrence, regardless of thyroxine treatment or not. We conclude that routine prescription of thyroxine is not warranted for lobectomised patients. It seems preferable to offer these patients occasional follow-up for functional assessment and thyroid palpation.

Female↗