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A Suneson

Publications and source records attributed to A Suneson.

24 records · Page 2Linked to original sources
PubMed1990

Pressure waves caused by high-energy missiles impair respiration of cultured dorsal root ganglion cells.

High-energy missile extremity impact causes short-lasting pressure waves which traverse the body with a velocity close to that of sound in water. In order to elucidate mechanisms for distant damage in a living body to the peripheral and central nervous system, a model system was designed aimed to create pressure waves with amplitudes, frequency spectrum, and duration fairly comparable to those recorded in situ. Our model system enabled exposure of tissue cultures of dorsal root ganglion (DRG) and endothelial cells under strictly controlled conditions to a burst of oscillating pressure waves and to determine possible influence on oxygen consumption. Oscillating pressure waves caused by high-energy missile impact (velocity 1,200 m/s) reduced the oxygen consumption by more than 80%. However, in spite of this drastic, acute effect the ganglion cells and the feeder layer cells did not reveal any immediate plasma membrane dysfunctions as revealed by cytoplasmic uptake of Evans blue protein marker complexes. It is concluded that pressure waves fairly similar to those demonstrable in vivo in the vicinity of the peripheral and central nervous system after high-energy missile extremity impact in pigs reduce the respiration of DRG cells and endothelial cells in culture. The mitochondrial impairment is not associated with concomitant plasma membrane dysfunction for macromolecules. Nerve cells seem to be more vulnerable than the other type of cultured cells examined.

Animals↗
PubMed1989

Pressure wave injuries to rat dorsal root ganglion cells in culture caused by high-energy missiles.

A high-energy missile impact in an extremity of an animal creates a shock wave which is rapidly dispersed as a burst of oscillating pressure waves that traverses the entire body causing local, regional, and distant injuries. The present study was performed on dorsal root ganglion (DRG) cells, cultured for 3 weeks, to elucidate the cellular mechanism for damage of nerve cells, using a simplified test system. A model system was developed allowing exposure of DRG cultures to a burst of high-frequency oscillating pressure waves, comparable to those recorded in animals after high-energy missile extremity impact. The pressure waves were induced by impact of a high-energy missile in a rubber tube filled with water, in which nerve cell cultures were kept in a closed rubber glove filled with tissue culture medium. The pressure waves had a duration of 0.5-1.5 ms and a frequency spectrum ranging from 0-250 kHz. Within minutes the neurites showed changes in their microtubules. In addition, varicosities, enriched with tubulin immunoreactive material, became irregularly studded along the nerve cell processes. Scattered DRG cells were initially permeable to the marker complex Evans-blue albumin (EBA), used as an indicator of the ability of the plasma membranes to exclude proteins. After 6 hr, however, almost every DRG neuron was intensely stained by EBA. Concomitantly, there was swelling of the nerve cell cytoplasm and organelles, and, to a variable extent, neurofilament tangles were observed.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1987

Peripheral high-energy missile hits cause pressure changes and damage to the nervous system: experimental studies on pigs.

The aim of the present study was to investigate pressure changes and possible damage to the central and peripheral nervous system induced by a high-energy missile striking a peripheral extremity. Anesthetized pigs were shot with a high-velocity missile (1,500 ms-1) in their left thigh. Transducers placed in the abdomen and brain recorded short-lasting bursts (1.0 to 1.5 ms) of oscillating pressure waves of high frequency. The amplitude of the pressure waves within the brain was about 125 KPa, and in the abdomen about 270 KPa, with a mean value of transferred energy from the missile of about 700 joules. Concomitantly, there were one or two apneic periods with a duration of a few seconds during the first minute after the shot. No significant changes in the heart rate, blood pressure, or other circulatory parameters were detected. Minor blood-brain and blood-nerve barrier damage occurred. It is concluded that the pressure waves caused by hits of peripheral parts of the body by high-energy missiles may be of such a large magnitude that distant damage to nervous tissue may result.

Abdomen↗
PubMed1979

Myelocystocele with cerebellar heterotopia. Case report.

The authors describe a case with well differentiated cerebellar tissue contained in a hydromyelic dilation of the spinal cord, that is, myelocystocele, in connection with a cervicothoracic meningocele. The embryology is discussed.

Adult↗
PubMedDate not supplied

Short-term crystalloid fluid resuscitation in uncontrolled intra-abdominal bleeding in swine.

INTRODUCTION: Fluid therapy in uncontrolled bleeding is controversial. In a previously used experimental animal model of aortic injury, the outcome often was impaired by re-bleeding that began at least 20 minutes after crystalloid fluid resuscitation was initiated. Therefore, it was hypothesized that re-bleeding might be avoided if volume loading is carried out for 20 minutes and then discontinued. METHODS: Ten minutes after a 5 mm laceration was produced in the infra-renal aorta on eight anesthetized pigs, they received a 20-minute intravenous infusion of Ringer's solution in the ratio of 1:1 to the expected blood loss. Hemodynamics were studied for 120 minutes using arterial and pulmonary artery catheters and blood flow probes placed proximal and distal to the aortic lesion and around the left renal artery and portal vein. RESULTS: The bleeding stopped between three and four minutes after the onset of bleeding. The blood flow rate dropped to 38% (mean) of baseline in the splanchnic region, to 31% in the upper aorta, and to 13% in the kidney. The flow rates and the oxygen consumption increased transiently during fluid resuscitation, but never reached baseline levels. Re-bleeding amounted to about 15% of the initial bleeding and occurred in only three of the animals. Four of the pigs died of shock within 90 minutes (range 47-85 minutes) after the aortic injury. CONCLUSION: Short-term crystalloid fluid therapy in uncontrolled aortic hemorrhage transiently improved the hemodynamic status and the oxygen consumption following the initial bleeding. Furthermore, the infusion did not cause re-bleeding of more than 100 ml, which occurred in previously conducted experiments when the infusion was continued for more than 20 minutes.

Animals↗