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Biomedical subjects

D H Lewis

Publications and source records attributed to D H Lewis.

At least 145 records · Page 8Linked to original sources
PubMed1977

Platelets, fibrinogen, and pulmonary haemodynamics in early experimental septic shock.

The relationship between platelet trapping, fibrinogen, and pulmonary haemodynamics after iv injection of disintegrated Pseudomonas bacteria into dogs were studied. Platelets were labeled with 51Cr and fibrinogen with 125I. The number of circulating platelets and white cells decreased abruptly within 2 minutes after injection, remained low at 5 minutes, and thereafter slowly increased. At the same time there was a transient increase of 51Cr activity in the lung occurring simultaneously with a decrease in cardiac output and an increase in pulmonary vascular resistance. Pulmonary artery pressure remained constant during the first phase of the experiment and thereafter decreased. There were no signs of 125I-fibrinogen accumulation in the lungs during the 2 hours of the experiment. The results indicate that trapping of platelets and eventually leucocytes in the lungs are closely related to the initial pulmonary haemodynamic changes after injection of disintegrated bacteria, possibly both by release of vasoactive substances and mechanical blocking. This microembolism in the pulmonary microcirculation might be of importance for the development of the shock lung syndrome.

Animals↗
PubMed1976

Anaerobic bacteria associated with epizootics in grey mullet (Mugil cephalus) and redfish (Sciaenops ocellata) along the Texas Gulf Coast.

Anaerobic bacteria tentatively identified as species of Catenabacterium were recovered from brain, liver, kidney and blood of fish involved in a massive epizootic of grey mullet (Mugil cephalus) and redfish (Sciaenops ocellata). Pathogenicity was demonstrated for grey mullet (M. cephalus) and sea catfish (Arius felis) but not for channel catfish (Ictalurus punctatus) or white mice. Diseased fish were disoriented, weak and swimming at the surface of the water. Thioglycolate and salt bovine blood agar containing 40 microg/ml gentamicin were useful as selective culture media.

Animals↗
PubMed1976

Bath treatment of channel catfish with three broad-spectrum antibiotics.

Serum drug levels were measured in channel catfish following bath exposure to kanamycin, gentamicin and chloramphenicol. Kanamycin was absorbed at a rate sufficient to attain therapeutic blood levels in several treatment schedules. Therapeutic blood concentrations could not be attained with gentamicin or chloramphenicol following 24 hrs exposure at 80 and 100 microg/ml water concentrations, respectively.

Animals↗
PubMed1975

Retention of Salmonella typhimurium by certain species of fish and shrimp.

Marine fish (Mugil cephalus, Fundulus heteroclitus, Trachinotus carolinus), lake shrimp (Penaeus setiferus), and channel catfish (Ictalurus lacustris punctatus) were exposed to Salmonella typhimurium and cultured after 2 hours and at daily intervals for 30 days. Salmonella typhimurium was recovered from all exposed animals after 2 hours and for 30 days in all animals except P setifurus. The organisms could not be recovered from those shrimp after the initial sampling period. Apparent salmonellosis developed in certain specimens of M cephalus and T carolinus 10 to 14 days after exposure to S typhimurium.

Animals↗
PubMed1975

The immediate circulatory response to high-velocity missiles.

The immediate hemodynamic response to a high-velocity missile wound was studied in the hind legs of dogs. A spherical missile of constant mass and velocity was used. The immediate effect after the shot was a marked transient peak flow, which may be due to the effects of the pressure wave on the vascular bed, with a release of constrictor tone. The subsequent more constant increase of blood flow in the traumatized leg is of the same character as that seen following extensive soft-tissue contusion trauma. In addition to these local changes there was also a generalized effect with decreased blood pressure without a compensating increase in hear rate. This may be explained by the specific character of the trauma that a high-velocity missile produces.

Animals↗
PubMed1975

Cardiovascular effects of venous blood from missile wounds.

A cross-infusion model including two dogs was used. At intervals 20 ml of blood from the iliac vein of one dog (donor), was injected during 60 sec into the iliac artery in which flow was measured electromagnetically in another dog (recipient). 1 min after missile trauma of the hind leg of the donor, the withdrawn venous blood possessed strong dilator property, manifesting itself by a transient, significant increase of blood flow in the registered artery of the recipient. This dilator property of venous blood from the traumatized region was, however, only apparent following wounding by missiles of high velocity.

Animals↗
PubMed1975

Effects of intraarterial injection of contrast medium on regional circulation in soft tissue trauma.

The effects of repeated intraarterial injections of methylglucamine metrizoate on regional circulation were registered in soft tissue trauma to the dog hind leg. The circulatory disturbances were determined by hemodynamic measurements and by angiography. The changes of flow following injection of the contrast medium were related to the films. The informative arterial phase appeared in the time lag between injection and the flow increasing effect of the contrast medium both before and after trauma. No evidence of a cumulative effect was recorded.

Angiography↗
PubMed1975

Circulatory disturbances following missile wounding of soft tissue.

The early circulatory changes following high velocity missile wounding to soft tissue of an extremity were analysed by hemodynamic methods and serial angiography. The extent of the tissue injury and the functional disturbances were mapped out and the time-course of the alterations in blood flow was registered. Possible mechanisms for the observed abnormalities are discussed.

Animals↗
PubMed1975

Angiography of the dilator response in extremity trauma.

The dilatation of major arteries following early after extensive soft tissue trauma was demonstrated angiographically not to be affected by pharmacologic or mechanical contractile stimuli. The proximal spread of the dilatation was not abolished by the division and a reanastomosis of the vessel before the trauma. These results suggest loss or impairment of the contractile ability of the major arteries following early after the trauma.

Animals↗