Biomedical subjects
A Ghaem
Publications and source records attributed to A Ghaem.
Nasal response to substance P and methacholine in subjects with and without allergic rhinitis.
We compared the rise in nasal airway resistance (NAR) provoked by topical application of substance P (SP) and of methacholine (MCH) in seventeen patients suffering from rhinitis and fourteen control subjects. Challenges with SP or MCH were separated by a week or more. NAR was measured by posterior rhinomanometry before and 10 min after intranasal administration of SP (10-40 nmol) or MCH (3-12 mumol). The two groups of subjects had similar baseline levels of NAR and similar small responses to buffered saline. Substance P but not MCH provoked cutaneous flushing in all subjects. Both SP and MCH provoked a significantly greater increase in NAR in patients suffering from rhinitis than in control subjects. The increase in NAR was dose-dependent, and on a molar basis, SP was 375-500-fold more potent than MCH. Pretreatment with 200 micrograms of a topically active anticholinergic agent, oxytropium bromide, prevented the rise in NAR caused by 12 mumol of MCH but not that caused by 40 nmol of SP in six patients suffering from rhinitis. We conclude that SP is absorbed across the nasal mucosa and causes cutaneous vasodilation, that MCH and SP cause a greater rise in NAR in patients suffering from rhinitis than in control subjects, that SP is about 500-fold more potent than MCH in increasing NAR, and that the rise in NAR caused by SP is not mediated by postganglionic parasympathetic mechanisms.
Assessment of fusafungine anti-inflammatory activity by rhinomanometry.
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A preliminary evaluation of the effect of N-acetyl-aspartyl-glutamate on pollen nasal challenge as measured by rhinomanometry and symptomatology.
The preventive effect of a nasally administered single dose of the dipeptide N-acetyl-aspartyl-glutamate (NAAGA) on pollen-induced early nasal reaction as measured by rhinomanometry and symptomatology was investigated in a double-blind cross-over placebo controlled study in 18 patients with nasal sensitization to grass pollen. Mean nasal airways resistance at 20, 40, and 60 min post challenge was, respectively, 33%, 37% (P = 0.03) and 27% less after NAAGA than after placebo administration in the same patients. In contrast, no significant effect on sneeze count and rhinorrhoea was found.
Occupational allergic rhinitis.
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[Anterior rhinomanometry and intranasal challenge tests. Technique and results in 270 cases. Usefulness for the aetiological diagnosis of vasomotor rhinitis (author's transl)].
Nasal response to a large number of stimuli is almost invariably the same, with sneezing, watery rhinorrhoea and nasal obstruction constituting the three major conventional symptoms of the so-called vasomotor (autonomic) rhinitis. These symptoms are not specific to allergic reactions but can be seen in viral infections, sudden changes in temperature, inhalation of irritant fumes or of certain smells. The aetiological diagnosis of vasomotor rhinitis therefore is sometimes very difficult but seems to be greatly facilitated by intranasal challenge tests associated with anterior rhinomanometry.
[Measurement of the flow in the segment of a limb. Validation of ultrasonic velocimetry using an impulsion Doppler effect (author's transl)].
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Comparison of plethysmographic methods with pulsed Döppler blood flowmetry.
Hand blood flow was measured at rest, with local warming, and with local cooling. Three methods were simultaneously used: water plethysmography (WP), mercury-in-rubber strain gauge plethysmography (SG), and pulsed Döppler flowmetry (D). Of these, water plethysmography is the most sensitive and accurate; strain gauge plethysmography is simpler but less accurate; and pulsed Döppler flowmetry precisely measures instantaneous arterial blood flow without venous occlusion.
Effects of ambient and local cutaneous temperatures on hand blood flow.
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Antagonistic effects upon cutaneous circulation of muscular excercise and exposure to a high ambient temperature.
Measurements were made in man of heart rate (Fc), arterial blood pressure (Pa), cutaneous blood flow (Z) (by plethysmography of the hand) as well as variation sin venous volume (deltaV) in the course of muscular exercise of 70 Watts intensity corresponding from 48% to 60% of the maximal oxygen consumtion of the subjects. These exercises were carried out at ambient temperatures of 22 degrees and 29 degrees C. for 8 min. In every case, an initial lowering of the Q and deltaV followed by a progressive climb was found. The average maximal reduction in output was virtually identical at 22 degrees and 29 degrees C (4.10 +/- 2.05 and 4.00 +/- 2.31 ml/min. 100 cm3). But the average maximal fall in volume turned out to be less at 29 degrees C (0.30 +/- 0.40 ml/100 cm3) than at 22 degrees C (0.60 +/- 0.60 ml/100 cm3). The resistive sector of cutaneous circulation conserves the same vasomotor capacities at the two ambient temperatures studied; the cutaneous capacitive sector shows lower reactivity at the higher ambient temperature. This would suggest that diminished venous return may be partially responsible for poor tolerance to exercise in warm climates.
[The reaction of resistance and capacitance vessels of the hand at the beginning of muscular exercise].
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[Proceedings: Energy cost of an exercise performed in apnea as compared with the energy cost of the same excercise performed in normopnea].
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[Proceedings: Blood flow in the hand as a function of ambient temperature and local temperature: comparison between the 2 sexes].
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[Reaction of the cutaneous circulation to muscular exercise at a high ambient temperature in non-acclimatized subjects].
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[Influence of muscular exercise intensity on the venous volume of the hand].
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[Rhinomanometry study of patients with respiratory allergy].
To examine the accuracy of nasal allergic disease, we examined the results of skin tests, measurement of serum specific IgE (RAST), and the nasal response to nasal challenge in 886 patients clinically suspected of having allergic respiratory disease. Nasal responses were assessed by measuring nasal airway resistance by both active anterior and posterior rhinomanometry. Nasal airway resistance was determined 25 min. after intranasal nebulization of saline solution and after administration of increasing doses of allergen (maximum dose = 280 micrograms). The dose of allergen causing a 100% increase over the value obtained after saline (Ri) at a flow rate of 0.15 l.s-1 was taken as the threshold dose (Dl). Our findings were that active anterior and posterior rhinomanometry yield comparable results; in subjects with a positive response to antigen challenge, the increase in nasal airway resistance correlated well with the dose of allergen administered and a significant inverse relationship was found between Ri and Dl; 3) a high level of serum specific IgE accurately predicted nasal responsiveness to a particular allergen, whereas skin tests were often positive to allergens that had no detectable effect on the nasal resistance. We conclude that nasal allergen provocation tests with rhinomanometric measurement of nasal resistance is a useful procedure for diagnosis of nasal allergic disease.
[Determination of nasal resistance in healthy subjects using 2 technics of rhinomanometry].
Transnasal pressure-flow relationship was studied by active rhinomanometry. Nasal resistance was determined by a microprocessor assisted technique during quiet inspiration in 106 adults (49 females and 57 males) and in 52 children (21 girls and 31 boys) in various circumstances. The study was performed 1) to calculate the airflow nasal resistance (R) in different subjects, 2) to determine the laminar (K1) and turbulent (K2) coefficients of flow in the upper airways according to Rohrer's equation: R = K1 + K2 V, and 3) to compare the results of anterior and posterior rhinomanometry. The results of the experiments show that 1) nasal resistance was constant during the nasal cycle and from one week to another in the same subjects; 2) nasal resistance were higher in females than in males, and higher in children than in adults depending on nose development; and 3) the nasal resistance measured by posterior rhinomanometry (RP) was approximately twice as by anterior rhinomanometry (RA) and the correlation was highly significant. The regression line was RA = 0.82 RP - 0.06 in kPa . 1(-1) . s (r = 0.998). Anterior rhinomanometry was easier to perform than posterior rhinomanometry and more useful for performing challenges of the nasal mucosa.