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Biomedical subjects

A Oliven

Publications and source records attributed to A Oliven.

At least 19 recordsLinked to original sources
PubMed1992

Chlamydial infections of the heart.

Chlamydiae are common human pathogens, causing a broad spectrum of infectious diseases. Chlamydial infections involving the heart have been described in numerous previous reports. These organisms are documented to cause endocarditis, myocarditis and pericarditis. Furthermore, Chlamydia pneumoniae, the recently discovered respiratory pathogen, has also been implicated in coronary artery disease. For the first time the literature on involvement of the heart in chlamydial infections is reviewed. Information on the discovery of Chlamydia species is also included and the problem of the species determination of Chlamydia in interpretation of the older literature is mentioned.

Chlamydia↗
PubMed1992

Inspiratory muscle activity during pulmonary edema in anesthetized dogs.

Pulmonary edema is known to induce a rapid and shallow breathing pattern. However, its effects on the level and pattern of distribution of motor activity to the respiratory muscles is unclear. In the present study we evaluated the effect of oleic acid induced pulmonary edema on the electrical activity of the inspiratory muscles (costal and crural diaphragm and parasternal and external intercostal muscles) in the dog, and related it to the transdiaphragmatic pressure and ventilatory parameters over the course of CO2 rebreathing. Pulmonary edema, reflected by a 7.1 +/- 0.6 wet to dry ratio, decreased lung compliance by 57%, increased pulmonary shunt to 35%, and was associated with a rapid and shallow breathing pattern. When compared at equal levels of PCO2 during CO2 rebreathing before and during edema, ventilation and mean inspiratory flow were increased only at lower levels of hypercapnia and their responses to increasing levels of PCO2 were significantly diminished during edema. Transdiaphragmatic pressures were elevated during edema as compared to control values. The rate of rise of the electrical activity of all inspiratory muscles increased significantly during edema at all levels of PCO2. Peak activity, however, remained unchanged, due to shortening of the inspiratory duration. The EMG responses to progressive hypercapnia were not affected by edema. Pulmonary edema did not change the pattern of breathing and neural output to the inspiratory muscles in vagotomized dogs. We conclude that stimulation of pulmonary proprioreceptors during edema increases neural output to all inspiratory muscles. The neural response to hypercapnia is not altered by edema, and is additive to the vagal input. The ventilatory response to CO2 is blunted during severe edema, due to alterations in lung mechanics.

Anesthesia↗
PubMed1992

Expiratory muscle activity during pulmonary edema in the anesthetized dog.

The present study evaluated the reflex response of the expiratory muscles to pulmonary congestion and edema. The electromyograms of two thoracic and four abdominal expiratory muscles were recorded in 12 anesthetized dogs. Pulmonary edema was induced by rapid saline infusion in six dogs and injection of oleic acid into the pulmonary circulation in the remaining six dogs. Both forms of pulmonary edema reduced pulmonary compliance, interfered with gas exchange, and induced a rapid and shallow breathing pattern. The electrical activity of all abdominal muscles was suppressed during both forms of pulmonary edema. In contrast, the electromyogram activity of the thoracic expiratory muscles was not significantly affected by pulmonary edema. Acute pulmonary arterial hypertension produced in two dogs by inflating a balloon in the left atrium had no effect on ventilation or expiratory muscle electrical activity. In two vagotomized dogs, pulmonary edema did not inhibit the expiratory muscles. We conclude that pulmonary edema suppresses abdominal but not thoracic expiratory muscle activity by vagal reflex pathway(s). Extravasation of fluid into the lung appears to be more important than an increase in pulmonary vascular pressure in eliciting this response.

Anesthesia↗
PubMed1992

Amelioration of sleep apnea by salicylate-induced hyperventilation.

It is well documented that upper airway (UAW) muscle activity is augmented in response to increased respiratory drive, the overall effect being an improvement in UAW patency. We have recently shown that salicylate-induced ventilatory stimulation increased UAW muscle electrical activity and decreased UAW resistance and collapsibility in anesthetized dogs. In the present study, we evaluated the effect of respiratory stimulation produced by high therapeutic doses of aspirin on sleep in nine patients with previously diagnosed sleep apnea. A control, all-night, polysomnographic sleep study, including oximetry and ventilatory monitoring by inductive plethysmography, was compared with a second study undertaken after patients ingested 8 to 10 g of aspirin over a period of 4 to 5 h. Aspirin ingestion resulted in high therapeutic salicylate serum levels (33 +/- 2.5 mg/dl, mean +/- SE) the following morning and was associated with marked ventilatory stimulation. Mean sleep duration and the relative partitioning of sleep stages were not affected by aspirin. However, aspirin-induced hyperventilation was associated with a significant non-rapid decrease in periodic breathing and the frequency of both obstructive and mixed apneas in all non-rapid eye movement (REM) sleep stages. The total number of apneas over the whole night was reduced in all subjects and on average fell from a control rate of 42 +/- 7 to 28 +/- 7 apneas/h (p less than 0.01). Similarly, the mean duration of apneas fell from 23 +/- 2 to 20 +/- 1 s (p less than 0.05), and the overall time spent in apneas decreased from 17 +/- 3 to 10 +/- 3 min/h (p less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1991

Dilated cardiomyopathy associated with Chlamydia trachomatis infection.

A 26-year-old man was admitted to hospital with acute myocarditis complicated by congestive heart failure, and atrial and ventricular arrhythmias. Detailed investigations to determine the aetiological factors involved yielded negative results, except for serological evidence of infection with Chlamydia trachomatis. During the follow-up period, dilated cardiomyopathy developed. To the best of our knowledge a similar case has not been reported previously.

Adult↗
PubMed1990

Anatomic evidence of spontaneous intrauterine closure of a ventricular septal defect.

An infant, born to a mother on carbamazepine monotherapy, had a complex cardiac anomaly, consisting of double-outlet right ventricle (DORV), right-sided aorta, pulmonary artery hypoplasia, left ventricular endocardial fibroelastosis, and anatomic evidence of a spontaneously closed muscular ventricular septal defect (VSD). The last finding is one which, to the best of our knowledge, has never been illustrated before.

Asphyxia Neonatorum↗
PubMed1990

A new method for selective left main bronchus intubation in premature infants.

Unilateral massive pulmonary atelectasis, and pulmonary interstitial emphysema (PIE) are problems that frequently occur in ventilated premature infants. Selective main bronchus intubation (SBI) of the atelectatic lung, or the contralateral lung in unilateral PIE, is an accepted procedure. However, whereas right SBI is usually easily performed, left SBI is frequently difficult. We have developed a method for left SBI using a regular portex endotracheal tube in which an elliptical hole 1 cm in length has been cut through half the circumference 0.5 cm above the tip of the oblique distal end. With the elliptical side hole directed to the left lung, left SBI can easily, and repeatedly be accomplished. This method may prove life saving in certain cases of unilateral atelectasis or PIE.

Bronchi↗
PubMed1990

Distribution of motor activity to expiratory muscles during sciatic nerve stimulation in the dog.

The present study examined the effect of increasing sensory input from the lower limbs (assessed from the response to electrical stimulation of the sciatic nerve) on the distribution of electrical activity to the expiratory muscles. Expiratory muscle response to sciatic nerve stimulation (SNS) was compared to the response of the inspiratory muscles, and to their response to hypercapnia. In 16 anesthetized dogs afferent SNS increased ventilation and augmented the integrated EMG of all six expiratory muscles studied. Increases in abdominal muscle electrical activity were not uniform, being greater in the transversus abdominis and external oblique as compared to the internal oblique and the rectus abdominis. Increases in thoracic expiratory and inspiratory muscle activity during SNS were similar in magnitude. SNS performed while dogs were breathing 7% CO2, produced increased neural activity similar to those observed during O2 breathing. During CO2 rebreathing, at equal levels of minute ventilation, expiratory muscle responses to SNS and to CO2 were similar. In contrast, the rate of rise of the inspiratory muscle EMGs was greater during SNS. The present study indicates that the abdominal muscles participate in the respiratory response to afferent neural drive from skeletal muscles. The magnitude of their response is independent of their pre-stimulation level of activity and is similar to that observed during CO2 stimulated breathing.

Abdominal Muscles↗
PubMed1990

Transient atrial fibrillation precipitated by hypoglycemia.

Two noninsulin-dependent diabetic patients developed transient atrial fibrillation precipitated by hypoglycemia that reverted to sinus rhythm after administration of IV dextrose. Atrial fibrillation as a complication of hypoglycemia in diabetic patients has been reported in only two patients with insulin-dependent diabetes mellitus.

Aged↗
PubMed1990

Effect of dantrolene on ventilation and respiratory muscle activity in anaesthetized dogs.

The effect of dantrolene on ventilation and ventilatory muscle activity was evaluated in spontaneously breathing anaesthetized dogs. When administered as a bolus of 1.5 mg kg-1 i.v., dantrolene caused hypercapnia. Under isocapnic conditions, with end-tidal PCO2 maintained at 8.1 (SEM 0.3) kPa by adjusting inspired carbon dioxide, dantrolene decreased tidal volume from 475 (66) to 254 (46) ml and breathing rate from 21 (4) to 15 (3) b.p.m. (P less than 0.01 for both). Occlusion pressure was reduced, but the rate of rise of the diaphragm and intercostal EMG were unchanged and peak activity increased only as a result of prolongation of inspiration. Respiratory variables returned gradually to baseline values 1 h after dantrolene administration. Phrenic nerve stimulation revealed a marked reduction in the ability of the diaphragm to generate pressure, particularly at low frequencies of stimulation. Only partial recovery was observed after 1 h. It is concluded that dantrolene causes hypoventilation in the anaesthetized dog when given in large doses i.v.

Action Potentials↗
PubMed1990

Termination of intractable hiccups with digital rectal massage.

A 60-year-old man with acute pancreatitis developed persistent hiccups after insertion of a nasogastric tube. Removal of the latter did not terminate the hiccups which had also been treated with different drugs, and several manoeuvres were attempted, but with no success. Digital rectal massage was then performed resulting in abrupt cessation of the hiccups. Recurrence of the hiccups occurred several hours later, and again, they were terminated immediately with digital rectal massage. No other recurrences were observed. This is the second reported case associating cessation of intractable hiccups with digital rectal massage. We suggest that this manoeuvre should be considered in cases of intractable hiccups before proceeding with pharmacological agents.

Hiccup↗
PubMed1989

[Heart-lung transplantation for idiopathic pulmonary fibrosis].

Diffuse idiopathic pulmonary fibrosis (DIPF) carries a poor prognosis, with an average survival of 4 years. A 37-year-old man had been followed by our department for over 5 years for biopsy-proven DIPF. The disease progressed relentlessly, unresponsive to corticosteroid or colchicine treatment. Marked pulmonary hypertension and right heart failure developed. Arterial pO2 decreased to 30 mmHg and he became bedridden and totally dependent on oxygen inhalation. A heart-lung transplantation was successful in June 1987. The anti-rejection regimen included cyclosporine and azathioprine. Subsequently his functional capacity improved remarkably and pO2 reached 87 mmHg on ambient air. Regular weekly followup visits have included physical examination, chest X-ray, cyclosporine blood levels, blood counts and determination of renal function. During a year of followup there has been no rejection episode nor any other major complication. Although experience with lung transplantation for end-stage DIPF is still limited, it is gradually being accepted as the only successful therapeutic approach. The case presented is the first in Israel of successful heart-lung transplantation for DIPF.

Adult↗
PubMed1989

[Recurrent unilateral pulmonary edema due to left heart failure].

Unilateral pulmonary edema is uncommon and is usually associated with prolonged surgical procedures or rapid evacuation of a hydro- or pneumothorax. Unilateral pulmonary edema due to left heart failure in the absence of known lung disease is rare. It is therefore not readily recognized and is often confused with other unilateral alveolar or interstitial infiltrates. We describe 2 patients, a 69-year-old man and a 78-year-old woman, who had repeated episodes of unilateral pulmonary edema due to left heart failure. In both cases several other diagnoses were considered, but the cardiac origin of the infiltrates was supported by the rapid clearing of the lung after diuretic therapy. Awareness of this unusual clinical condition is important for the early institution of proper therapy.

Aged↗