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Biomedical subjects

S Freedman

Publications and source records attributed to S Freedman.

At least 55 records · Page 3Linked to original sources

Obstructive sleep apnea (OSA)-implications in maternal-fetal medicine. A hypothesis.

During the past fifteen years the obstructive sleep apnea syndrome (OSAS) has become widely recognized as a quite common disorder with a wide range of serious clinical complications (1, 2, 3). This syndrome arises as a result of sleep related changes in upper airway muscle function and progressive narrowing of the oropharyngeal lumen. The resulting hypoxia (or asphyxia) leads to an arousal response that terminates the initial obstructive event. The exact incidence and prevalence of OSAS is currently unknown. Lavie (4) concluded its prevalence to be 1.26 percent. Others (5, 6) found that the prevalence of heavy regular snoring (taken as an index of at least a partially obstructed airway) increased with age including 40 percent of women and 50 percent of men over 60 years of age. Polygraphically documented OSAS showed incidence of 0.99 percent in an unselected population. Postmenopausal women have frequent episodes. of OSA in contrast with their premenopausal counterparts, who very rarely have any apnea. Since we could not find in the literature any documented OSAS studies in pregnancy, we would like to base our hypothesis on our previously published clinical observations and our recent findings. In the present paper we would like to suggest that pathophysiologic changes of OSAS prolonged throughout many weeks of pregnancy may have an adverse effect upon the feto-placental unit.

Adult↗

Abolition of methacholine induced bronchoconstriction by the hyperventilation of exercise or volition.

Total pulmonary resistance was measured from continuous records of flow and oesophageal pressure in five normal subjects on three separate days before and after inhalation of methacholine. The dose of methacholine produced, on average, a fivefold increase in airway resistance. Immediately after methacholine inhalation the subjects underwent a progressive exercise test on a cycle ergometer (day 1) or voluntary hyperventilation (day 2) or remained resting (day 3). On the first day during exercise pulmonary resistance fell rapidly to baseline levels within two to three minutes and remained there for the 10 minute duration of the exercise. On day 2 voluntary reproduction of the same level and pattern of ventilation as during exercise resulted in a similar fall of resistance. On the third day, when the subjects remained at rest, pulmonary resistance remained raised for 10 minutes. It is concluded that the bronchodilator effects of exercise can be explained by the increased ventilation rather than the exercise itself, but with much smaller tidal volumes than have previously been thought necessary to reduce drug induced bronchoconstriction.

Adult↗

Breathlessness and respiratory mechanics during reflex or voluntary hyperventilation in patients with chronic airflow limitation.

1. Six patients with chronic airflow limitation rebreathed CO2. Subsequently they voluntarily copied their stimulated breathing pattern while normocapnia was maintained. On a separate occasion four of these patients performed progressively increasing exercise and later copied these breathing patterns. 2. During all experiments flow, ventilation and pleural pressures were recorded. In addition, breathlessness was measured on a visual analogue scale every 30 s. 3. In these patients voluntary copying of either form of stimulated breathing resulted in diminished breathlessness and in some cases in complete abolition of the sensation, despite similar levels and patterns of ventilation in the two situations. 4. No systematic or consistent differences in the mechanics of breathing between stimulated and voluntarily copied breathing were found. 5. There was no correlation found between breathlessness score and any mechanical variable measured. 6. These results show that despite similarity in mechanics between stimulated and voluntary hyperventilation, the sensation of breathlessness is much diminished during the latter in these patients. This suggests that the sensation of breathlessness is more dependent upon the awareness of central processing than upon input from peripheral mechanoreceptors.

Aged↗

Multiple squamous papillomas of the esophagus associated with Goltz syndrome.

A 30-yr-old white female with a history of focal dermal hypoplasia (Goltz syndrome), chronic gastroesophageal reflux, and dysphagia was found to have, by barium esophagram and esophagogastroduodenoscopy, multiple 2- to 3-mm papillary projections in the distal esophagus and an esophageal stricture. Biopsy of these lesions revealed squamous papillomas and a benign stricture. Although chronic irritation from gastroesophageal reflux has been suggested as a possible etiology of acquired esophageal papillomas, the previous association of congenital papillomas of the oral mucosa in Goltz syndrome suggests that the multiple papillomas in this patient are congenital in origin.

Adult↗

Bilateral comparison of generalized lichen planus treated with psoralens and ultraviolet A.

Ten patients with generalized lichen planus were treated with oral 8-methoxypsoralen photochemotherapy (PUVA) in a bilateral comparison study. Five patients (50%) cleared completely on both sides and required no maintenance treatment after a follow-up of up to 4 years. Three other patients (30%) improved at least 50% of their previous involvement. Most of the patients experienced symptomatic improvement of the treated side by the second week of the treatment. Two patients reacted adversely and exacerbated while receiving treatment to one side of the body. While preliminary, this bilateral comparison study demonstrates that PUVA is an effective therapy for generalized, symptomatic lichen planus and suggests that maintenance therapy might not be required once complete clearance is attained. Caution should be exercised, however, since some patients might develop an exacerbation of their disease with PUVA.

Adult↗

Histiocytosis-X: in situ characterization of cutaneous infiltrates with monoclonal antibodies.

Cutaneous lesions in three cases of histiocytosis-X were studied by light microscopy, electron microscopy, and immunoperoxidase technics. In each case, Birbeck granule-containing histiocytosis-X cells infiltrated the epidermis and were apposed to lymphocytes. The histiocytosis-X cells and normal Langerhans cells stained with anti-T6 and anti-I1 (Ia-like) antibodies but were negative with anti-T3, anti-T8, anti-M1, and anti-lysozyme antibodies. In addition, the histiocytosis-X cells also stained with anti-T4 antibodies, which react with T-cells associated with helper/inducer phenotype. This study supports the hypothesis that histiocytosis-X cells are abnormal Langerhans cells. The presence of T4/T6-positive cells in cutaneous disease may be a marker for abnormal Langerhans cells.

Antibodies, Monoclonal↗

Blood lactate and respiratory muscle fatigue in patients with chronic airways obstruction.

Blood lactate concentrations were measured in five patients with chronic airways obstruction after 10 minutes' sustained maximal voluntary ventilation (SMVV) with end-tidal carbon dioxide tension kept constant and after a 12-minute walk. No patient showed a significant rise in blood lactate after SMVV but all showed evidence of low-frequency fatigue of the sternomastoid muscle. After a 12-minute walk three patients showed a significant rise in blood lactate and two of them also had evidence of low-frequency fatigue of the sternomastoid muscle. The absence of a rise in blood lactate after SMVV may be due to the fact that in patients with chronic airways obstruction ventilation is limited by airflow obstruction to a level where only a small muscle mass is used, or where the aerobic capacity of the respiratory muscles is not exceeded.

Aged↗

Desmopressin in nocturnal enuresis.

The response of desamino-D-arginine vasopressin (DDAVP) was investigated in 32 enuretic children in a double-blind clinical study. The 15 children treated with DDAVP showed a significant reduction in the incidence of bed wetting--from 18.7 +/- 6.5 to 6.5 +/- 9.2 wet nights per 30 days. In 6 children bed wetting stopped entirely, in 6 there was a satisfactory response, and in 3 the response was marginal or there was none. When DDAVP was stopped most children reverted to their earlier bedwetting habits (15.7 +/- 8.9 nights a month). Response to DDAVP was significantly better in children aged more than 10 years (mean age for the entire group). The administration of DDAVP was not associated with any appreciable change in morning urine osmolalities. No adverse effects were noted. It is concluded that DDAVP is effective in nocturnal enuresis, particularly in older children. It is suggested that the cessation of bed wetting may, in part, reflect functional properties of DDAVP rather than antidiuresis.

Adolescent↗

Invasive pulmonary aspergillosis in an apparently nonimmunocompromised host.

Invasive aspergillosis generally occurs in patients with hematologic malignancies, neutropenia or other severe derangements of host defense. An adult patient without such a predisposition, and without a previous history of susceptibility to infections, had rapidly progressive respiratory failure associated with repeated growth of Aspergillus fumigatus on culture of sputum and bronchoscopy specimens. At autopsy he proved to have invasive pulmonary aspergillosis.

Aspergillosis↗

Lung volumes.

Explore the source record for details and available documents.

Aging↗

A comparison of oral and inhaled steroids in patients with chronic airways obstruction: features determining response.

Two trials comparing aerosol and oral steroid treatment were carried out in patients with chronic airways obstruction. All patients had a history of chronic productive cough and an FEV1 less than 70% predicted but did not have episodic or seasonal breathlessness with wheezing. One trial involved 18 outpatients, the other 18 inpatients. Both studies involved three consecutive treatment periods, the first with placebo aerosol, the second with active aerosol (betamethasone valerate, 800 microgram/day), and the third with oral prednisone or prednisolone (30 mg/day). Six patients showed a significant improvement in ventilatory capacity on steroids. Initial assessment included a comprehensive history using a questionnaire, skin tests, blood and sputum eosinophil counts, and chest radiography. In addition, for the inpatients, response to isoprenaline, daily sputum volume, and PaCO2 were measured. Only blood eosinophilia and variability in ventilatory capacity during the placebo period seemed indicative of a likely response to steroids. However, there was a large overlap between various features on assessment in the responders and non-responders, and the management of every patient with chronic airways obstruction should include a controlled trial of steroids. The steroid aerosol produced a good improvement in ventilatory capacity in the responsive patients who were hospitalised and this was thought to be helped by supervision of aerosol technique. Such an aerosol could therefore be used for a steroid trial although oral steroids were found to give a more definitive response.

Administration, Oral↗