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Biomedical subjects

A J Block

Publications and source records attributed to A J Block.

At least 145 records · Page 8Linked to original sources
PubMed1976

Living cytology: A new diagnostic technique for malignant pleural effusions.

The efficacy of a new tissue-culture technique for the diagnosis of malignant pleural effusions was contrasted with conventional cytologic methods. The new technique is based on the ability of the tissue-culture medium to transform mesothelial cells into fibroblasts while not sustaining lymphoreticular cells. Against a background of fibroblasts, islets of adenocarcinoma are easily identified. Of 20 patients with pleural effusions and solid tumors, the tissue-culture technique correctly diagnosed eight (40 percent), compated to seven (35 percent) for conventional cytologic methods. Of 27 pleural effusions in patients without malignant neoplasms, there was only one probable false-positive.

Adenocarcinoma↗
PubMed1976

A trial of aerosolized theophylline in relieving bronchospasm.

Theophylline was administered as an aerosol to nine patients with known bronchospastic disease. No significant improvement in the forced expiratory volume in one second was observed after administration of aerosolized theophylline, although improvement did occur following administration of aerosolized isoproterenol. The theoretic mechanisms of bronchodilator aerosols are discussed, as well as the possible reasons for not obtaining a response with administration of theophylline.

Adult↗
PubMed1975

Anoxia-induced release of prostaglandins in rabbit isolated hearts.

We investigated the relationship between prostaglandin release and the coronary vasodilation evoked by anoxia. Isolated rabbit hearts were perfused via the aorta with Krebs-Ringer's solution. The coronary effluent was bioassayed continuously in terms of prostaglandin E2 for prostaglandinlike substance which was present (at less than 1 ng/ml) in 60 of 66 hearts. This basal release was abolished by the prostaglandin synthetase inhibitor, indomethacin (1-2 mug/ml), a result which adds further to the identity of the prostaglandinlike substance as a prostaglandin. Anoxia increased coronary flow sometimes by 100% and evoked prostaglandin release shortly thereafter. Ablolition of prostaglandin synthesis by indomethacin pretreatment did not affect nor did infusion of exogenous prostaglandin mimic the anoxia-induced flow increment; thus, we conclude that prostaglandin release cannot account for the anoxia-induced vasodilator response. Furthermore, the failure of indomethacin to alter resting coronary blood flow suggests that a local prostaglandin release is not responsible for either the maintenance or the modulation of coronary flow in this preparation.

Animals↗
PubMed1975

Pulmonary function evaluation of the lung resection candidate: a prospective study.

In the past, preoperative pulmonary function abnormalities have identified a group of patients in danger of postoperative cardiorespiratory morbidity and mortality. We selected a group of 56 patients, each of whom had a lung mass and had demonstrated significant abnormalities in screening pulmonary function. By using temporary unilateral pulmonary artery occlusion and quantitative macroaggregate lung scanning, we then studied these patients for split pulmonary function. Those patients whose noncancerous lung had a calculated forced expiratory volume in 1 sec greater than 800 ml and a circulation that could accommodate all of the cardiac output without producing hypertension or arterial hypoxemia were offered thoracotomy. Of the 56 patients, we judged 6 to be physiologically inoperable and did not offer surgery. Another 4 patients were not offered surgery, and 4 refused surgery. Forty-two patients underwent surgical exploration-of these, 17 then had a pneumonectomy and 13, a lobectomy. Of the 30 patients resected, 6 died in surgery (4 from respiratory insufficiency). These cardiorespiratory mortality rates (neumonectomy, 17.6 per cent; lobectomy, 7.7 per cent) are lower than those reported previously when patients had equivalent pulmonary function abnormality. A follow-up of 49 of 56 patients revealed that 59 per cent of the patients undergoing either pneumonectomy or lobectomy were still living 1 to 3 years after the resection. Our results suggested that the preoperative testing of split pulmonary function permitted an attempt at surgery in patients who might otherwise be considered inoperable by history, physical examination, screening pulmonary function tests alone.

Aged↗
PubMed1975

Fatal pulmonary hemorrhage after transbronchial lung biopsy through the fiberoptic bronchoscope.

A case is reported in which transbronchial lung biopsy using the fiberoptic bronchoscope was complicated by massive, fatal hemorrhage. This previously unreported complication occurred despite normal prothrombin and partial thromboplastin times and platelets of 93,000. Pathological examination revealed that a very small (0.5-mm) vessel was the source of the bleeding. Although severe complications are undoubtedly rare, this report suggests that the transbronchial lung biopsy is not a totally benign procedure. Suggestions are made to prevent future similar occurrences in very ill patients or in patients with coagulative abnormalities or blood dyscrasias.

Biopsy↗
PubMed1975

Long-term results of continuous oxygen therapy at sea level.

Twelve patients with hypoxemia associated with severe chronic obstructive pulmonary disease were treated with continuous portable oxygen therapy and have been followed up for a mean period of 25.2 months at sea level. Pulmonary function testing has revealed no further significant deterioration at long-term follow-up (17 months). After oxygen therapy was initiated, arterial carbon dioxide tension increased slightly, but decreased to pretreatment levels when patients were allowed to breathe room air. The electrocardiogram, which was unchanged at one month, has shown some reversal of cor pulmonale in five patients. Six patients have died, yielding a 56 percent survival rate at two-and-one-half years by the life table analysis. Five patients were autopsied, with possible oxygen toxicity being present in only one. The quality of life in our patients was improved and was especially represented by a reduction in hospital admissions for respiratory illness. We believe that continuous oxygen therapy is beneficial and worthwhile economically in certain patients.

Altitude↗
PubMed1973

The influence of histamine and other vasoactive substances on contractile responses of cat skeletal muscle to acetylcholine.

1. The effect of vasoactive substances, chiefly histamine, on contractions of cat skeletal muscle evoked by acetylcholine has been studied. For this purpose all of these agents were administered intra-arterially to anterior tibialis, chiefly, and also to soleus and external rectus muscles in vivo.2. Under these conditions, histamine itself never altered the resting tension of the muscle, but always enhanced the increase in tension produced by acetylcholine injected shortly afterward.3. On the anterior tibialis muscle, it was determined that the threshold potentiating dose of histamine was 0.001 mug/kg, and that maximal enhancement occurred when 0.1 mug/kg was injected 15 s before fixed, submaximal doses of acetylcholine. Injected 15 s before graded doses of acetylcholine, histamine 0.1 mug/kg shifted the acetylcholine dose-response curves approximately 1.5 log units to the left.4. Under similar experimental conditions the vasodilator, bradykinin, 0.001-1 mug/kg, and procedures which produce a local increase in nutritive capillary blood flow also enhanced acetylcholine-evoked contractile responses of the anterior tibialis, whereas the vasoconstrictor, angiotensin, 0.001-1 mug/kg, inhibited them.5. The potentiating effect of histamine was antagonized by mepyramine, but was undiminished by denervation of the muscle either acutely or for 4 days.6. Histamine failed to enhance responses of the muscle to electrical stimulation of either the muscle, directly, or its motor nerve.7. Histamine also had no effect upon acetylcholine-evoked responses of the isolated external rectus muscle in vitro.8. It is suggested that the potentiating effect of histamine in vivo is due to its vasodilator action within the muscles which, by relaxing arterioles and precapillary sphincters, could allow more of the blood-borne acetylcholine to reach more of its receptors on the muscle fibres in a given time.

Acetylcholine↗