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Biomedical subjects

J M Wallace

Publications and source records attributed to J M Wallace.

At least 127 records · Page 7Linked to original sources

Percutaneous needle lung aspiration for diagnosing pneumonitis in the patient with acquired immunodeficiency syndrome (AIDS).

Fourteen patients with acquired immunodeficiency syndrome (AIDS) or suspected AIDS underwent percutaneous needle lung aspiration (PNLA) for evaluation of 16 occurrences of acute pneumonitis. A 22-gauge spinal needle was passed 2 to 3 times in the area of greatest radiographic involvement under fluoroscopic guidance. The specimen was immediately placed on microscope slides for Gomori's methenamine silver and Papanicolaou staining. The needle was then flushed with sterile water for bacterial, Legionella, viral, mycobacterial, and fungal cultures, and for Legionella immunofluorescent staining. Diagnostic information was provided by 14 of the 16 procedures. Of 11 patients ultimately found to have P. carinii pneumonitis, PNLA specimens were diagnostic in 10 (91%). Infectious agents other than P. carinii also were identified by PNLA, including cytomegalovirus (4 cases), M. avium-intracellulare (1 case), and pyogenic bacteria (3 cases). Complications of PNLA were: pneumothorax in 7 cases (44%), 3 (19%) of which required chest tube evacuation; and minor hemoptysis (less than 50 ml) in 2. The PNLA can be a useful diagnostic procedure in the patient with AIDS and pneumonitis. It has the advantages of being less costly and time-consuming than fiberoptic bronchoscopy. It is, however, frequently complicated by pneumothorax, making it an inappropriate approach for patients with significant respiratory compromise.

Acquired Immunodeficiency Syndrome↗

Increase in ovulation rate after treatment of ewes with bovine follicular fluid in the luteal phase of the oestrous cycle.

Administration of charcoal-treated bovine follicular fluid to Damline ewes twice daily (i.v.) from Days 1 to 11 of the luteal phase (Day 0 = oestrus) resulted in a delay in the onset of oestrous behaviour and a significant increase in ovulation rate following cloprostenol-induced luteolysis on Day 12. During follicular fluid treatment plasma levels of FSH in samples withdrawn just before injection of follicular fluid at 09:00 h (i.e. 16 h after previous injection of follicular fluid) were initially suppressed, but by Day 8 of treatment had returned to those of controls. However, the injection of follicular fluid at 09:00 h on Day 8 still caused a significant suppression of FSH as measured during a 6-h sampling period. Basal LH levels were higher throughout treatment due to a significant increase in amplitude and frequency of pulsatile secretion. After cloprostenol-induced luteal regression at the end of treatment on Day 12, plasma levels of FSH increased 4-fold over those of controls and remained higher until the preovulatory LH surge. While LH concentrations were initially higher relative to those of controls, there was no significant difference in the amount of LH released immediately before or during the preovulatory surge. These results suggest that the increase in ovulation rate observed during treatment with bovine follicular fluid is associated with the change in the pattern of gonadotrophin secretion in the luteal and follicular phases of the cycle.

Animals↗

Ovulation rate and embryo survival in Damline ewes after treatment with bovine follicular fluid in the luteal phase of the oestrous cycle.

Treatment of Damline ewes with twice daily i.v. injections of bovine follicular fluid during the luteal phase for 10, 6 or 2 days before prostaglandin-induced luteolysis resulted in an increase in ovulation rate. This was associated with a large rebound increase in plasma concentrations of FSH after the last injection of bovine follicular fluid. While conception rate was not affected by bovine follicular fluid treatment, a higher percentage embryonic loss was observed between Days 3 and 34 of pregnancy in the 10-day treatment group only compared to controls. This reflected the increase in ovulation rate above the optimum for embryonic survival in this breed. The present results suggest that the increase in ovulation rate induced by bovine follicular fluid treatment in the luteal phase of the cycle before mating would result in a significant increase in the number of lambs born.

Animals↗

Cellular and T-lymphocyte subpopulation profiles in bronchoalveolar lavage fluid from patients with acquired immunodeficiency syndrome and pneumonitis.

The cellular composition and T-lymphocyte subpopulations of bronchoalveolar lavage (BAL) fluid from 12 patients with acquired immunodeficiency syndrome (AIDS) and active pneumonitis were examined. Differential cell counts were performed on BAL specimens from each patient and from 25 normal subjects. The BAL and peripheral blood (PB) lymphocytes were isolated from 8 patients and 11 subjects. Leu 4 (mature T), Leu 2 (T suppressor), and Leu 3 (T helper) markers were identified by fluorescein-labeled monoclonal antibody agents and counted in an automated flow cytometer. Infectious pneumonitis caused by Pneumocystis carinii and/or cytomegalovirus and/or Mycobacterium avium-intracellulare was diagnosed in all but 1 patient. All but 2 patients demonstrated lymphocytosis in the BAL fluid; only 3 had greater than 1% neutrophils. The BAL cell differentials were not predictive of the type of pneumonitis. The Leu 3/Leu 2 ratios were (mean +/- SEM): 0.08 +/- 0.03, patients' BAL fluid; 1.55 +/- 0.21, subjects' BAL fluid; 0.18 +/- 0.06, patients' PB; 1.42 +/- 0.12, subjects' PB. The marked decrease in Leu 3/Leu 2 ratios primarily reflected severely diminished proportions of Leu 3 positive cells (3 +/- 1.3% compared with a control value of 35 +/- 4.0%), although the proportion of Leu 2 positive cells tended to be elevated as well (46 +/- 7.9% compared with a control value of 22 +/- 2.2%). Bronchoalveolar lavage specimens from patients with AIDS and these types of pneumonitis may contain increased proportions of lymphocytes. The accumulation of lymphocytes, however, does not reflect homing of helper T-lymphocytes to the site of pulmonary infection.

Acquired Immunodeficiency Syndrome↗

A guinea pig model to study effects of persistent intrabronchial antigenic stimulation and inflammation.

Chronic antigenic stimulation and inflammation of the bronchial tree occurs in several diseases involving microbial airway colonization. We developed a guinea pig model to study the effects of persistent intrabronchial antigenic stimulation with keyhole limpet hemocyanin (KLH). Sepharose beads 200 to 300 micron in diameter conjugated with 300 micrograms KLH were injected via a tracheostomy catheter, causing them to lodge in the bronchial tree. When lung sections from these animals and animals given uncoupled sepharose beads were examined histologically, it became apparent that in this model the persistent antigenic stimulus is accompanied by local inflammation caused by an irritant effect of the beads. To determine how the intrabronchial antigen was distributed locally and systemically, 125I labeled KLH-coupled beads were administered. Radioactivity remained predominantly in the lung, where 13 +/- 5% of the administered dose was still detectable by Day 30. Autoradiographs of Day 30 lung sections demonstrated that the radioactivity was concentrated on the individual beads, indicating that it largely represented KLH persisting in the bronchial tree. Minute amounts of radioactivity were detected systemically and in the regional lymph nodes (LN). A radioimmune assay of serum collected on Day 1 demonstrated that some of the circulating radioactivity represented antigenic KLH. When anti-KLH antibody-forming cells (AFC) were measured in lung homogenate, regional LN, blood, and spleen cell preparations after KLH-coupled bead administration, they were initially detected only in the spleen. Significant concentrations appeared in the lung homogenate, regional LN, and spleen by Day 10 and thereafter through Day 20.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

Patterns of pulmonary perfusion scans in normal subjects.

The prevalence of abnormal pulmonary perfusion (Q) scans in persons without cardiopulmonary disease could condition the usefulness of the Q scan in the evaluation of patients in whom pulmonary embolism is suspected. In a recent study, we found that Q scan defects, particularly lobar or segmental defects, are rarely present in normal young nonsmokers. To determine if normal smokers of the same age group have a higher prevalence of Q defects, we performed 6 view Q scans in 40 subjects 18 to 29 yr of age who had no known active cardiopulmonary disease. Each subject had undergone a history, physical examination, electrocardiogram, spirometry, and posteroanterior chest roentgenogram prior to scanning. All Q scans were interpreted blindly and independently by 2 experienced readers. None of the 40 subjects was found to have an abnormal Q scan defined as the presence of a lobar, segmental, or subsegmental defect on 2 views. When these data were compared with our previous study, statistical analysis found no difference in the prevalence of abnormal Q scans in the 2 groups. We conclude that among young normal persons, abnormal Q scans are extremely uncommon and the prevalence of significant Q defects is not influenced by smoking.

Adolescent↗

Flexible fiberoptic bronchoscopy and percutaneous needle lung aspiration for evaluating the solitary pulmonary nodule.

We reviewed the records and chest roentgenograms of 133 patients who underwent flexible fiberoptic bronchoscopy (FFB) for a solitary pulmonary nodule (SPN), defined as a circumscribed density less than or equal to 4 cm in diameter surrounded by aerated lung with no associated radiologic abnormalities. Each patient had a complete medical examination followed by FFB with collection of bronchial washings and brushings, transbronchial biopsy (when technically possible), and postbronchoscopy sputum collection. Subsequently 50 patients underwent percutaneous needle aspiration (NA) and 32 diagnostic thoracotomy (DT). Eight-two (62 percent) of the evaluations resulted in a histologic diagnosis. Prebronchoscopy sputum was diagnostic in three patients. Of 143 FFBs performed, 27 (19 percent) were diagnostic, and 26 were the first procedure of the evaluation to provide a diagnosis. Following nondiagnostic FFB, a diagnosis was provided by 50 (36 percent) NA, 32 of 32 (100 percent) DT, and 3 of 3 (100 percent) cervical and mediastinal node biopsy procedures. For both FFB and NA, there was a strong correlation between nodule size and diagnostic yield. FFB visualized a vocal cord lesion in five patients and an endobronchial mass in five. The combination of FFB and NA provided a diagnosis in 45 of 51 (88 percent) patients ultimately proved to have a malignant SPN. Neither procedure was diagnostic in any of the 24 patients with a benign SPN. We conclude that FVFB and NA have complementary roles in the evaluation of SPN.

Adult↗

Flexible fiberoptic bronchoscopy for diagnosing pulmonary coccidioidomycosis.

To assess the diagnostic yield of flexible fiberoptic bronchoscopy (FFB), we reviewed records of 30 patients who had (1) cultural and/or histologic evidence of coccidioidomycosis, (2) abnormal chest roentgenograms, and (3) undergone FFB. Each patient underwent a complete examination including sputum collection for smears and culture. As additional diagnostic information was needed, FFB was performed in all patients, followed by percutaneous needle aspiration in 4 patients and thoracotomy in 10. Prebronchoscopy sputum cultures yielded Coccidioides immitis in 6 of 30 patients (20%). Bronchoscopy provided specimens diagnostic of coccidioidomycosis in 16 of 30 patients (53%), and in 10 of 30 (33%), FFB was the first procedure of the examination to produce a diagnostic specimen. The diagnosis was first obtained by needle aspiration in 1 of 30 (3%), by extrathoracic specimens in 3 of 30 (10%), and by thoracotomy in 10 of 30 (33%). All 8 patients with a solitary pulmonary nodule (SPN) had nondiagnostic FFB and comprised the majority of patients not diagnosed until thoracotomy was performed. When patients with a SPN were excluded, 20 of 29 (69%) FFB procedures documented coccidioidal infection. Seven of 22 (32%) prebronchoscopy sputum collections compared with 17 of 29 (59%) FFB procedures produced positive cultures for C. immitis. One of 22 (5%) prebronchoscopy sputum collections, compared with smears and biopsies from 8 of 29 (28%) FFB procedures, produced immediate microscopic evidence of coccidioidomycosis. Coexisting pulmonary pathologic findings in 4 patients were uncovered by FFB. Except in patients with a SPN, FFB is a valuable procedure for documenting pulmonary coccidioidomycosis when sputum specimens are nondiagnostic.

Biopsy, Needle↗

Patterns of pulmonary perfusion scans in normal subjects.

A vital factor conditioning the usage of the pulmonary perfusion (Q) scan in the evaluation of patients suspected of pulmonary embolism is the prevalence of abnormal Q scans in subjects free of cardiopulmonary disease. Because this prevalence has not been well defined, we performed Q scans in 80 nonsmoking subjects 18 to 29 yr of age having no known active cardiopulmonary disease. Each subject underwent a history, physical examination, electrocardiogram, spirometry, and PA chest roentgenogram, followed by a 6-view Q scan. Two subjects in whom a Q defect was suspected underwent a 133Xe equilibrium-washout ventilation (V) scan. All Q scans were interpreted blindly and independently by 2 experienced readers. Seventy-nine of the 80 Q scans were read as normal. No subject demonstrated a lobar or segmental defect. One of the 80 subjects, who had a mild pectus excavatum, had a left upper lobe subsegmental defect, which was not seen on the V scan. Based on the statistical analysis of these data, no more than 3.68% of normal nonsmoking persons in this age group may have a lobar or segmental Q scan defect and no more than 6.77% may have a subsegmental defect (with 95% confidence). Therefore, our study indicated that Q scan defects, particularly lobar or segmental, are rarely present among normal nonsmokers in this age group.

Adolescent↗

Hemodynamic effects of the converting enzyme inhibitor teprotide in normal- and high-renin hypertension.

The hemodynamic effects of the converting enzyme inhibitor teprotide (SQ 20881) were investigated in five patients with normal plasma renin activity who were normotensive during the study (group I), in five patients with hypertension and normal plasma renin activity (group II), and in five patients with hypertension and high plasma renin activity (group III). No significant hemodynamic changes were observed during teprotide administration in group I. In group II there was a decrease in mean arterial pressure by 10 +/- 2% (p < 0.005) that was associated with a decrease by 16 +/- 7% (p < 0.05) in stroke volume and cardiac output, possibly due to venodilatation and without a concurrent change in total peripheral resistance. In group III the larger decrease of 19 +/- 4% (p < 0.005) in mean arterial pressure was due to a decrease by 30 +/- 3% (p < 0.005) in peripheral resistance. In this group stroke volume and cardiac output increased by 13 +/- 2% (p < 0.025). There were no compensatory changes in heart rate despite the decrease in mean arterial pressure and vasodilatation. These results indicate that teprotide decreases arterial pressure by a dual hemodynamic mechanism. Cardiac output is increased by teprotide in patients with high-renin hypertension who exhibit the greatest decrements in peripheral resistance.

Adult↗

The immediate pressor response to saralasin in man: a test of angiotensin II receptor vacancy.

Saralasin, 10 microgram/kg per min, caused an immediate rise in blood pressure in 52 of 57 (91.2%) hypertensive patients. The increase in diastolic pressure averaged 18.8 +/- 1.83 mm Hg (mean +/- SE) in normal renin patients on a normal salt intake. This immediate pressor response was absent in only five high renin patients and, conversely, was very large in three low renin patients. Direct arterial recordings are necessary to define the response accurately; it begins in 60--90 seconds, peaks in amplitude at 2.05 +/- 0.38 minutes, and subsides over the next 5 minutes in normal renin and high renin patients. The blood pressure elevation is inversely related to background plasma renin activity (r = -0.66, P less than 0.001), and also is directly, but weakly, related to 24-hour urinary sodium excretion (r = + 0.29). Therefore, the amplitude of the elevation is predictably diminished by the rise in plasma renin consequent to prior sodium restriction, and also by preliminary receptor exposure to low dose nonpressor infusions of saralasin itself (0.01-0.1 microgram/kg per min). Phentolamine had no effect on the response in two patients. We propose that the immediate pressor response to saralasin is related directly to the preexisting degree of vacancy of angiotensin II vascular receptors and that the initial agonistic action of the drug may prove useful in defining the angiotensin II receptor status in hypertensive diseases.

Angiotensin II↗