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Biomedical subjects

A J Popp

Publications and source records attributed to A J Popp.

29 records · Page 2Linked to original sources
PubMed1982

Agents for the treatment of brain injury. 1. (Aryloxy)alkanoic acids.

Blunt and ischemic injuries of the brain have been shown to result in swelling that is predominantly limited to a single cell type, the astrocyte, within the complex cellular mosiac of cerebral gray matter. Evaluation of various diuretic (aryloxy)acetic acids in vitro using incubating cat brain slices and primary astrocyte cultures identified compounds with marked ability to inhibit brain tissue swelling. Some of the compounds significantly reduced the mortality and morbidity following acceleration/deceleration brain injury in anesthesized cats. A variety of (indanyloxy)alkanoic acids were synthesized which were analogous to the dually active (indanyloxy)acetic acids. Some of the 4-(indanyloxy)butanoic acids were found to be devoid of diuretic activity but to possess equal or greater activity than the dually active compounds in the in vitro and in vivo brain assays. Selected examples from both the (indanyloxy)acetic and 4-(indanyloxy)butanoic acid series showed marked chiral effects, with one enantiomer generally exhibiting a much greater activity than the other. A clinical study of severely head-injured patients treated with ethacrynic acid demonstrated a significantly improved outcome when compared to controls. These data suggest a clinical advantage for the nondiuretic (aryloxy)alkanoic acids which possess in vitro and in vivo activities in the cat brain assays that are comparable or superior to dually active compounds.

Animals↗
PubMed1982

Delayed pulmonary dysfunction in head-injured patients.

Intracranial pressure (ICP), cardiopulmonary function, and the degree of neurological dysfunction were measured in 13 patients with serious head injury to determine the relationship of these indices to the development of delayed pulmonary dysfunction. All patients had serious isolated head injury with Glasgow Coma Scale scores of 7 or less 6 hours after injury and elevated ICP at the time of admission to the protocol. Three patients developed arterial pO2 of less than or equal to 80 torr despite the initiation of elevated inspired oxygen fraction (FIO2 greater than or equal to 0.5) and positive end expiratory pressure (greater than or equal to 5 cm H2O. One of these three patients had a decline in neurological function, quantified by the Albany Head-Injury Watch Sheet, associated with hypoxemia. The only patients who developed intrapulmonary shunt fractions of more than 15% were five patients who had increased pulmonary vascular resistance (PVR) and elevated or increasing cardiac index, suggesting persistent perfusion to areas of the lung which normally are hypoperfused due to hypoxic pulmonary vasoconstriction. This mismatching of the distribution of ventilation and perfusion was confirmed using the multiple inert gas elimination technique in two patients with an increased shunt fraction. Unperfused gas exchange units were also found to be present, as confirmed by an abnormal multiple inert gas elimination techniques, high PVR and dead space/tidal volume ratio (VD/VT), and low extravascular lung water. Abnormalities of ICP and cerebral perfusion pressure could not be correlated with changes in any of the cardiopulmonary functions studied.

Adolescent↗
PubMed1981

Adenosine-stimulated astroglial swelling in cat cerebral cortex in vivo with total inhibition by a non-diuretic acylaryloxyacid derivative.

The intact cerebral cortices of cats were exposed in vivo under normothermic conditions and superfused with isotonic artificial cerebrospinal fluid containing added 0.125 mM adenosine. This resulted in chloridecation-rich cerebrocortical swelling which was shown by electron microscopy to be associated with an expanded astroglial compartment. The addition of DCPIB, a non-diuretic acylaryloxyacid analogue of ethacrynic acid and an inhibitor of coupled chloride-cation transport in cerebral cortex in vitro, totally blocked astroglial swelling and the concomitant increases in tissue ion contents. These studies support our previous experiments on the mechanism of formation of astroglial swelling. The pathological consequences of astroglial swelling and the clinical applications of these findings are discussed.

Adenosine↗
PubMed1980

Biology of glial swelling in experimental brain edema.

Most studies of clinically relevant cerebral edema emphasize the effect of added tissue fluid in white matter on gross distortion with transtentorial and subfalcine brain herniation. Our recent studies on altered tissue fluid compartmentation in cerebral gray matter suggest that significant microdistortion of relationships of capillaries to subserved tissue follows swelling of astroglia therein. Grave consequences to solute and gas exchange in focal regions may well be expected and are emphasized. The elucidation of the mechanisms of formation and inhibition of astroglial swelling by chemical agents, including chemically useful acylaryloxyacetic acid derivatives, are discussed. Furthermore, the effect of these agents in altering mortality and morbidity in a controlled, random study of animal head injury is presented.

Animals↗
PubMed1978

Numerical grading of clinical neurological status after serious head injury.

A scheme to quantitate the clinical neurological status of the seriously head-injured patient has been devised. The neurological parameters used to quantify the degree of injury are based on neurological functions which have previously been accepted as indicators of the severity of the head injury. A numerical value is assigned to each parameter with emphasis on defining the level of consciousness. The accrued point total of each examination represents the neurological status of the patient at that time. Mean values and standard error from the means are determined from repeated examinations during a single 24 hour period, and are plotted against days after injury. From this graph a line which represents the rate of clinical recovery is determined by least squares analysis. General intensive care nurses were trained to score patients independently; their determinations were found to be in statistical agreement with scores derived from examinations by the attending physicians. The data presented highlight the effects of hypoxaemia in impeding the rate of neurological recovery from a serious head injury. This simple clinical analytical scheme for the quantitative assessment of patients with head injury permits evaluation of the efficacy of various modes of therapy in altering the rate of recovery.

Adult↗
PubMed1978

Camurati-Engelmann disease (progressive hereditary craniodiaphyseal dysplasia). Case report.

In a patient with Camurati-Engelmann disease, orbital and optic nerve decompression resulted in improvement of papilledema. Subsequent x-ray films of the optic canals, however, revealed reconstitution of osseous optic canals bilaterally, and papilledema has returned in one eye. Definitive treatment of this dysplastic metabolic bone disorder rests in the control of rapid abnormal bone formation.

Bone Diseases, Developmental↗
PubMed1978

Delayed impairment of arterial blood oxygenation in patients with severe head injury: preliminary report.

A drop in the arterial PO2 occurring 24 hours after head injury was identified in eight patients. Traditional modes of therapy include administration of supplemental oxygen and provision of an unobstructed airway. The latter proved to be inadequate to continually maintain the PaO2 at a level consistent with the O2 content of the inspired air. Initially, determination of the PaO2, after institution of supplemental oxygen, may demonstrate adequate oxygenation, but blood gas monitoring should be continued since a delayed fall in arterial oxygen tension may occur 24 hours after head injury. This period of potentially deficient blood oxygenation, if severe enough, may further aggravate preexisting brain damage and profoundly affect the ultimate outcome of the patient. The delayed fall in PaO2 is the result of intrapulmonary shunting principally due to a ventilation/perfusion mismatch. The precise mechanism of the ventilation/perfusion inequality in the brain-injured patient awaits further elucidation, but may differ from the alteration in pulmonary function seen in the Respiratory Distress Syndrome.

Brain Edema↗
PubMed1977

Extracranial to intracranial vascular anastomosis for occlusive cerebrovascular disease: experience in 110 patients.

In an attempt to ascertain the value of extra- to intracranial arterial bypass for cerebrovascular disease, the general topic of bypass surgery is reviewed and the results of this procedure in 110 patients are analyzed. The feasibility of high patency rates of the anastomosis with acceptably low permanent morbidity and operative mortality rates is demonstrated. Lesions producing transient ischemic attacks which previously were considered to be inoperable or inaccessible can be bypassed by this procedure, and there appears to be a dramatic improvement in the symptomotology of virtually all patients. Patients with a mild stroke or "progressive stroke" also appear to benefit from bypass, but the erratic natural history of these entities precludes irrefutable substantiation of this conclusion. Patients with moderate-to-serve neurological deficits do not appear to be improved by this procedure. In our group of 20 patients presenting with transient ischemic attacks who have had more than 3 years of follow-up, only one patient has suffered a stroke and that was located in the opposite hemisphere.

Adult↗
PubMed1976

Sensory Jacksonian seizures.

Sensory Jacksonian seizures were analyzed in 42 patients with regard to anatomical and temporal sequences. The origin of sensory Jacksonian seizures, in contrast to motor Jacksonian seizures, often began at peripheral sites with littel cortical representation. The progression of seizure activity across the cerebral cortex followed a course that was neither rectilinear, radiate, nor random; it appeared to preceed in an organized manner to involve functionally coherent units. The patterns analyzed conformed more closely to cortical somatosensory maps reported for the chimpanzee than the sensory sequences presently available for the cortex of man. Complete diagnostic studies are indicated in patients presenting with sensory Jacksonian seizures because of the frequency of related focal pathology.

Arm↗