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Biomedical subjects

V Popa

Publications and source records attributed to V Popa.

At least 19 recordsLinked to original sources
PubMed2001

Accuracy of in vivo carotid B-mode ultrasound compared with pathological analysis: intima-media thickening, lumen diameter, and cross-sectional area.

BACKGROUND AND PURPOSE: This study aimed to determine the correlation of in vivo ultrasound measurements of intima-media thickening (IMT), lumen diameter, and cross-sectional area of the common carotid artery (CCA) with corresponding measurements obtained by gross pathology and histology. METHODS: Sixty-six moribund neurological patients (mean age 71 years) underwent B-mode ultrasound of the CCA a few days before death. During autopsy, carotid specimens were removed in toto. Carotid arteries were ligated and cannulated for injection of a hydrophilic embedding material under standardized conditions. The carotid bifurcation was frozen and cut manually in 3-mm cross slices. Digital image analysis was carried out to determine the diameter and the cross-sectional area of the frozen slices of the CCA. IMT was assessed by light microscope. Ultrasonic and planimetric data were compared. RESULTS: Mean measurements of lumen diameter and cross-sectional area were 7.13+/-1.27 mm and 0.496+/-0.167 cm(2), respectively, by ultrasound, and 7.81+/-1.45 mm and 0.516+/-0.194 cm(2), respectively, by planimetric analysis of the unfixed redistended carotid arteries (R(2)=0.389 and 0.497). The mean IMT was 1.005+/-0.267 mm by ultrasound and 0.67+/-0.141 mm histologically, resulting in a mean difference of -31%. CONCLUSIONS: Transcutaneous B-mode ultrasound provides a reliable approach for in vivo measurements of the cross-sectional area and, less exactly, of the lumen diameter of the CCA. Compared with histological results, in vivo ultrasound measurements of the IMT are systematically larger.

Adult↗
PubMed2000

Visualization of the basilar artery by transcranial color-coded duplex sonography : comparison with postmortem results.

BACKGROUND AND PURPOSE: Transcranial color-coded sonography (TCCS) via the suboccipital approach allows direct and continuous visualization of the basilar artery (BA). In this study, we intended to evaluate the ability of native TCCS in visualizing the length of the BA by means of a comparison with postmortem measurements. METHODS: The BA was prospectively studied by TCCS shortly before death (median 3 days) in 46 moribund neurological patients (mean+/-SD age 71.1+/-13.1 years). The length of the BA was determined by measuring the distance between the vertebrobasilar junction and the deepest available flow signal in the top of the BA. During autopsy, photos of the vertebrobasilar system were taken to evaluate the true anatomic length and variations of the course of BA in situ, eg, straight, curved, or S-shaped. RESULTS: Comparison of the in vivo ultrasound measurements of BA length and postmortem data was possible in 44 of 46 cases. In the 2 remaining patients, the BA was occluded. The mean insonation depth of the vertebrobasilar junction was found at 66.9+/-7.1 mm. The mean BA length was 21.5+/-6. 8 mm by color-coded duplex and 32.9+/-6 mm anatomically (P<0.0001). The mean difference between color mode and anatomic findings was 11. 3+/-6.4 mm in the case of a straight BA (35 cases) and 16.3+/-4.8 mm in an anatomically tortuous course of the BA (9 cases). CONCLUSIONS: Color duplex imaging enables correct visualization of the proximal two thirds of the BA, but only exceptionally of its distal one third. A tortuous course of the BA leads to an underestimation of its anatomic length.

Basilar Artery↗
PubMed1999

Immediate hypersensitivity in adults with IgG deficiency and recurrent respiratory infections.

BACKGROUND: Little is known about the prevalence of atopy in adults with recurrent respiratory infections and IgG deficiency. OBJECTIVE AND METHODS: To elucidate this aspect, we skin-tested 95 consecutive adults with respiratory infections, subnormal levels of IgG subclasses or common variable immunodeficiency and usually poor response to vaccination. In 50 subjects we also measured total IgE. RESULTS: We found 67 subjects with IgG subclass deficiency, 21 subjects with mild (partial) and 5 with usual common variable immunodeficiency, and 2 subjects with functional IgG deficiency. Atopy was encountered in 42/95 subjects, 33/44 (75%) with asthma, 7/19 (38%) with isolated rhinosinusitis, 1/27 (4%) with chronic obstructive lung disease, and 1/5 (20%) with both the latter disease and asthma, respectively. Atopy was preferentially clustered in subjects with asthma (P < .05) who were less than 40 years of age (P < .05) and nonsmoking. Atopy was not affected by the type of IgG deficiency, unless it was usual common variable immunodeficiency, in which case the skin tests tended to be negative (4/5). Total IgE was within normal range but less elevated than usually seen in asthma or chronic obstructive lung disease. Total IgE was independent of the type of IgG deficiency, except for usual common variable immunodeficiency in which it remained < 10 IU/mL. CONCLUSIONS: In adults with symptomatic IgG deficiency, the prevalence of immediate hypersensitivity and its modulation by age and smoking are similar to the referred, non-IgG deficient population; however, total IgE may be lower in the former than in the latter. In common variable immunodeficiency, consistent with the literature data, both the prevalence of atopy and serum total IgE are decreased.

Adult↗
PubMed1997

Interleukin 1 beta, tumour necrosis factor-alpha and interleukin 1 receptor antagonist in newly diagnosed insulin-dependent diabetes mellitus: comparison to long-standing diabetes and healthy individuals.

Interleukin 1 beta (IL-1) and tumour necrosis factor alpha (TNF) are important for the beta cell lysis in insulin-dependent diabetes mellitus (IDDM), while IL-1 receptor antagonist (IL-1ra) is considered protective by blocking the effects of IL-1. Serum concentrations and ex-vivo production of IL-1, TNF and IL-1ra were examined in 10 newly diagnosed IDDM (ND-IDDM) patients, and compared with 11 long-standing IDDM (LS-IDDM) patients and 14 healthy volunteers. Ex-vivo LPS-stimulated production of IL-1 in ND-IDDM patients was significantly increased compared with LS-IDDM patients and healthy controls, while TNF and IL-1ra synthesis did not differ significantly. IL-1ra/IL-1 ratio was significantly decreased in ND-IDDM, and returned to normal values in the LS-IDDM group. Circulating concentrations of IL-1ra in LS-IDDM patients were increased. These data suggest a proinflammatory imbalance in ND-IDDM patients and this may play an important role in beta cell loss.

Acute Disease↗
PubMed1997

A study of the radiobiological effectiveness with track etch detectors.

CR-39 nuclear track detectors have been used in this experiment to study the killing effect of low energy protons on V79-753B Chinese hamster cells and to monitor the proton beam. The estimated surviving fractions and the beam parameters are comparable to those found with conventional electronic devices. The surviving fractions fitted by the linear quadratic model support the idea of single-hit mechanism for the cell killing.

Animals↗
PubMed1994

Codeine-induced bronchoconstriction and putative bronchial opiate receptors in asthmatic subjects.

To determine whether a mu opiate agonist can constrict the human airways, the dose of codeine (C) or histamine (H) producing a 40% decrease (PD40) in specific airway conductance (SGAW) was measured in 17 asthmatic and 14 normal subjects. Then, the subjects were skin tested with C and H, and the effect of naloxone (N) and chlorpheniramine (CP) on PD40-C was assessed. In five asthmatic subjects responding to less than 5 mg (16.6 mumol) inhaled C, SGAW was also recorded after oral administration (30 mg) and pharyngeal spraying (5 mg) of C. PD40-C could be determined in 11 of the 17 asthmatics but in none of the normal subjects. This constrictor effect lasted less than 15 min, was unrelated to resting airway caliber, and required a relatively high bronchial sensitivity to H (PD40-H usually less than 0.2 mumol) and high doses of C (11.93 +/- 12.0 mumol). However, in C responders, PD40-C and PD40-H were unrelated. C-induced bronchoconstriction was blunted by N in a dose-dependent fashion and to a mild and inconsistent degree, by CP. Pharyngeal spraying or oral challenge with C failed to change SGAW. Skin sensitivity to H and C was similar in C-responders and non-responders. In conclusion, large doses of inhaled C constrict the airways of asthmatic subjects highly sensitive to H. This effect seems mediated through (mu?) opiate receptors located bronchially rather than centrally, pharyngeally or in the skin. In C-induced bronchoconstriction H liberation plays a contributory but minor role. Skin and bronchial sensitivity to C are unrelated.

Adolescent↗
PubMed1994

Airway obstruction in adults with recurrent respiratory infections and IgG deficiency.

In 42 adults with recurrent respiratory infections (RRI) and common variable immunodeficiency or immunoglobulin G (IgG) subclass deficiency, the results of pulmonary function tests were related to factors apt to produce airway obstruction: serum concentration of IgG and IgG subclasses, various features of acute RRI (number/year, time from onset to diagnosis, episodes of pneumonia, etc) and type of chronic lung disease (smoking and nonsmoking related chronic bronchitis, episodic wheezing, and bronchiectasis). Compared with nonsmokers, usually less than 40 years of age, the patients above 40 had smoking-related chronic bronchitis and had obstruction (%FEV1/forced vital capacity [FVC] 55.3 +/- 8.1 vs 80.1 +/- 4.5), hyperinflation (residual volume 182.7 +/- 22.7 percent vs 109.7 +/- 8.8 percent of pred) hypoxemia (66.6 +/- 5.8 vs 83.4 +/- 4.2 mm Hg) and impaired carbon monoxide transfer (65.5 +/- 9.1 percent vs 93.3 +/- 5.8 percent). The features of acute or chronic RRI, the time from onset to diagnosis (< 10 yr in the entire group), the type of IgG deficiency or the serum concentration of the deficient protein did not correlate with substantial obstruction (FEV1/FVC < 70%). In conclusion, in adults with IgG deficiency and RRI for less than 10 yr, smokers with chronic bronchitis rather than nonsmokers develop substantial airway obstruction.

Adult↗
PubMed1994

Physiologic factors affecting the discriminant ability of provocation doses to histamine.

The discriminant ability of six provocation doses of histamine, PD10, PD15, PD20, PD10T, PD20C, and PD40 has been reported. The subscript connotes -%delta SGaw (PD40), -%delta FEV1 > or = 10% (PD10T), -%delta measured with the lowest (PD20C) or the best FEV1 (PD10, PD15). To explain the differing discriminant ability of the six provocation doses (PD20 = PD15 > PD10T = PD40 > PD20C > PD10), this study analyzed the role of % delta/variability, log dose-response curve, airway hysteresis and the test itself in the original group of 20 normal and 20 asthmatic subjects. For provocation doses measured with the best FEV1, the discriminant ability was related to the ratio %delta/variability and the frequency with which various provocation doses were located on the steep portion of the log dose-response curve; these two parameters and the steepness of the latter were similar in normal and asthmatic subjects. The low discriminant ability of PD20C did not depend on %delta/variability or steepness of the log dose-response curve but on its high rate of false positive results. The lower discriminant ability of PD40 than PD20 or PD15 could not be related to any of the factors analyzed. In conclusion, the factors influencing the calculation of provocation doses affect differently the discriminant ability of these endpoints: (1) %delta/variability and steepness of log dose-response curve influence the provocation doses based on best FEV1. (2) Airway hysteresis reduced the proportion of normals with asthmatic provocation doses, increasing the rate of false positive results with PD20C, based on the smallest FEV1. (3) The nature of the tes, SGaw versus FEV1, affects the discriminant ability of PD40 in a still obscure way.

Asthma↗
PubMed1993

Wheezing triggered by dorsal decubitus: pulmonary function changes.

UNLABELLED: In 23 subjects with chronic obstructive pulmonary disease (COPD) who wheezed when changing their position from sitting to dorsal decubitus (DD), we recorded lung volumes and flow volume loops in sitting (S1), DD and immediately after resuming sitting (S2). We found three main patterns of ventilatory changes associated with wheezing in DD: (1) acute obstruction (AO) in 14 subjects characterized by FEV1 > or = -10% and %FEV1/FVC > or = -3%; functional residual capacity or residual volume was increased, decreased or unchanged; (2) acute restriction (AR) in 7 subjects characterized by absence of obstruction spirographically and FVC and/or FRC > -10%; (3) indeterminate response (IR) in 2 subjects. Except for 3 subjects, the changes recorded in DD returned to baseline in S2. Both AO and AR responses in DD and their rapid resolution in S2 were reproducible (11 subjects). IN CONCLUSION: (1) in COPD, DD may trigger wheezing; (2) the physiologic changes during DD wheezing are reproducible, rapidly reversible when the sitting position is resumed and unlike those recorded during bronchoprovocation, heterogeneous.

Forced Expiratory Volume↗
PubMed1993

IgG deficiency in adults with recurrent respiratory infections.

Total IgA, IgM, IgG, and IgG subclasses were measured in 136 consecutive adults with recurrent respiratory infections. Sinus and chest radiographs were also obtained. IgG antibodies to H. influenzae and tetanus toxoid were determined in 27 immunodeficient subjects. Fifty-eight of the 136 were deficient in some immunoglobulin isotype, three in IgA, three in IgM, and 52 in total IgG or one or more IgG subclasses. The most common IgG deficiencies were single IgG subclass deficiencies, particularly IgG3 or IgG4, and a mild decrease in total IgG (between 450 and 650 mg/dL). In 21/27 subjects with IgG deficiency, the response to booster immunization was blunted, even when IgG1 and IgG2 were normal. Thirty-eight patients were smokers, 37 being > 40 years of age at the onset of respiratory infections. Twenty patients were nonsmokers, 19 being < 40 years of age at the onset. In conclusion, adults with recurrent respiratory infections frequently have some variant of IgG deficiency, often associated with a functional impairment of specific antibody response. Smoking may represent a risk factor for IgG deficiency in adults.

Adult↗
PubMed1990

The relationship between conductance and functional residual capacity during drug-induced bronchoconstriction.

UNLABELLED: We wondered if the inverse changes in airway conductance (Gaw) and functional residual capacity (FRC) during histamine (H) and acetylcholine (ACH) challenge are interrelated or occur at random. In 14 normal and 14 asthmatic subjects, we determined FRC and Gaw changes corresponding to changes in specific airway conductance (SGaw) around -40 percent produced by an aerosol of H or ACH inhaled quantitatively and with measured lung deposition. We also assessed the elastic recoil following H inhalation (5A). We found that in 11 normal and nine asthmatic subjects, after H or nine normal and 11 asthmatic subjects after ACH, Gaw and 1/FRC were linearly and directly related (p less than 0.05). The steepness of this slope was directly related to the resting Gaw values. A similar relation was uncovered in the literature for asthmatic patients at rest or during recovery from natural asthma. As the elastic recoil was normal and did not change after H, it could not explain delta FRC at delta SGaw of -40 percent. IN CONCLUSION: (1) during H or ACH challenge, Gaw-FRC relationship in normal or asthmatic subjects tends to be hyperbolic and dependent on resting Gaw; (2) such a relationship is seemingly present in other bronchoconstrictor responses with a different pathogenesis; and (3) during bronchoconstriction, as Gaw vs FRC is no longer linear, SGaw becomes volume dependent.

Acetylcholine↗
PubMed1989

The effect of inhaled naloxone on resting bronchial tone and exercise-induced asthma.

UNLABELLED: We wanted to determine whether 10 mg naloxone inhaled quantitatively could modulate the resting bronchial tone and respiratory response in exercise-induced asthma (EIA). In 11 asthmatic subjects, we measured specific airway conductance (SGaw) and forced expiratory flow (FEF) before and after the inhalation of naloxone or saline. In another 10 asthmatic subjects, we measured SGaw, FEF, and the ventilatory gas exchange, heart rate, and blood pressure responses produced by a treadmill exercise during 3 separate days: without any pretreatment (Day 1) or preceded by the inhalation of either 10 mg naloxone (Day 2) or saline (Day 3). We found that after 10 mg inhaled naloxone only one of 11 subjects bronchodilated, displaying an isolated, reproducible delta SGaw greater than 40% at 30 and 60 min. In the EIA protocol, the cardiopulmonary responses during exercise remained similar on all experimental days, but in seven of 10 subjects (all with %FEV1/FVC greater than or equal to 70% delta SGaw was -60 +/- 11%, + 1 +/- 40%, and -52 +/- 7% during no treatment, naloxone, and saline days, respectively (p less than 0.05). FEF changes were comparable on all days (p greater than 0.05). IN CONCLUSION: (1) consistent with the general role of endogenous opioids, these neurotransmitter/neuromodulators can modulate a stress-related bronchoconstrictor response (EIA), but only very seldom the resting bronchial tone. (2) Naloxone does not blunt EIA through a decrease in the asthmogenic stimulus (i.e., ventilation) or airway caliber change, but presumably through competition with the endogenous opioids released during exercise.

Administration, Inhalation↗
PubMed1988

Domiciliary metaproterenol nebulization: a bacteriologic survey.

We wanted to determine whether domiciliary jet nebulization (DJN) leads to contamination of the equipment with fungi or aerobic bacteria and, eventually, to respiratory colonization or pneumonia in daily users of the equipment. We surveyed from this standpoint 23 veterans 65 +/- 10.1 years of age, present or former smokers, treated with steroids more than 7 months in the year preceding the survey, and with FEV1/FVC of 42 +/- 11%; they all were daily users of the equipment, diluting the metaproterenol solution with nonbacteriostatic saline dispensed in multiple-dose bottles of 500 to 1000 ml (protocol 1 [P1]). After this protocol was completed, the large saline bottles were replaced by 20 cc vials; 11/23 completed 1 year of this treatment (protocol 2 [P2]). Equipment contamination was checked in all initial 23 patients after one-time nebulization in the laboratory with fresh material (protocol 3 [P3]). We found that DJN leads to equipment contamination in 20/23 subjects of P1 and 3/11 subjects of p2; saline bottles and the nebulizer were the most frequently contaminated items (32/41 equipment items in P1 and 10/55 in P2). The contamination was predominantly bacterial with oropharyngeal saprophytes (19 in p1, O in P2) or gram-negative bacilli (47 in P1, 8 in P2). Bacterial growth was heavier in P1 than in P2. During P3, three equipment items became contaminated in 3/23 subjects; the flora was oropharyngeal. No patient developed respiratory colonization or developed pneumonia during 9000 patient days of DJN.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1988

Pharmacodynamic aspects of chlorpheniramine-induced bronchodilatation.

In 12 asthmatic (A) and ten normal (N) subjects, we measured the effect of inhaled saline solution, acetylcholine, histamine (H), and chlorpheniramine (CP) on specific airway conductance and forced exploratory flows. We found that CP dilated the bronchi in six asthmatic patients and one normal subject by acting on bronchial H1 receptor. This action is also modulated by the abnormal functions of this receptor-transducer, explaining why CO exerts a tonic effect only in subjects with H hyperresponsiveness. Furthermore, as shown by CO and CP + H responses, bronchial histamine seems to be present primarily in large airways and in relatively small amounts. We also found that bronchial H, the abnormal H1 receptor-transducer, and the bronchial caliber are regulated independently of each other. Consequently, this limits the therapy with H1 blockers in asthma.

Acetylcholine↗
PubMed1988

Provocation dose and discriminant analysis in histamine bronchoprovocation. Are the current predictive data satisfactory?

In 20 normal subjects (N) and 20 asthmatic patients (A) using bronchodilators as needed, the PD40, PD10, PD15, PD20, PD10T, and PD20C were measured (PD being provocation dose, subscript being -% delta in Gaw/VL for PD40, lowest FEV1 for PD20C, and best FEV1 for the remaining PDs; 10T means delta FEV1 greater than -10 percent). For discriminant analysis we used an ad hoc graphic (best case) method, a ceiling method based on highest PD in A and two methods (logistic and linear) which considered PDs in both N and A (PDN and PDA, respectively). The distribution of PDN and PDA had substantial overlap and appeared log normal. The PD15, PD20, and PD20C displayed the smallest mean misclassification error followed by PD10T, PD40, and PD10. The linear and logistic methods produced balanced sensitivity and specificity but, predictably, a misclassification error higher than that of the graphic method. The ceiling method proved unsatisfactory with 100 percent sensitivity but approximately equal to 60 percent specificity. Using linear and logistic methods, the posttest likelihood of asthma could be expressed as a function of its pretest likelihood and level of PD recorded. We concluded that: (1) the most discriminant PDs are PD20, PD15 and PD20c; and (2) new normative data for diagnostic bronchoprovocation are needed, because: (a) when PDA and PDN overlap, the currently used ceiling method leads to a high misclassification rate, while the linear and logistic method based on mathematical model have a better discriminant ability; (b) to separate PDA from PDN and allow the application of the ceiling method, "as-needed bronchodilators" is not a reproducible criterion.

Adolescent↗