Biomedical subjects

M W Harrison

Publications and source records attributed to M W Harrison.

45 records · Page 3Linked to original sources

PubMed1982

Esophageal replacement in infants and children bv colon interposition.

Colon replacement for the esophagus was used successfully in 20 of 21 pediatric patients. Intrathoracic placement of the colon segment was done in 18. Careful preparation and operative experience combined to reduce operative morbidity and mortality in an unfortunate group of patients. Satisfactory long-term results have been achieved. Careful technique, attention to detail, and perfection of a single technique may be more important than performing new surgical techniques when they are reported. Colon interposition performed by the Waterston technique utilizing the transverse colon is an effective means of substitution for a diseases esophagus in children.

Body Weight↗

PubMed1982

The formation and effect of stored platelet concentrate microemboli on pulmonary ultrastructure.

The formation of microaggregates of platelets and leukocytes and the infusion of these aggregated blood elements in pulmonary ultrastructure and function have been extensively studied. This study was undertaken to document the formation of platelet microaggregates during storage of platelet concentrate and to determine what effect the infusion of stored platelets has on pulmonary ultrastructure. The screen filtration pressure of platelet concentrate stored at 4 degrees C. for a period of 48 hours was measured after six, 24 and 48 hours of storage. Screen filtration pressure progressively rose from a mean of 47.20 millimeters of mercury to a mean of 237.40 millimeters of mercury at 48 hours, p less than 0.02 between six and 48 hours of storage. Specimens of the lung taken for biopsy from ten patients undergoing open heart operations were examined for ultrastructural alterations. Those specimens obtained following cardiopulmonary bypass, but prior to the infusion of platelet concentrate, showed only mild ultrastructural abnormalities. Those specimens obtained for pathologic study following the infusion of platelet concentrate exhibited extensive accumulations of platelet aggregates in the pulmonary microcirculation and widespread degenerative changes in the capillary endothelial cells, intra-alveolar septae and alveolar epithelial cells. In areas in which cellular discontinuities occurred, protein exudates, fibrin clumps and red blood cells were observed in the interstitium and in the alveolar air spaces. The storage of platelet concentrate results in the formation of aggregate material. The infusion of platelet concentrate results in the formation of aggregate material. The infusion of platelet concentrate results in the formation of ultrastructural lesions, similar to those observed in situations known to lead to pulmonary dysfunction, such as following massive transfusion, hypovolemia, sepsis and hypoxia.

Biopsy↗

PubMed1981

Neonatal necrotizing enterocolitis. A 10 year experience.

Neonatal necrotizing enterocolitis was seen in 42 of 5,030 infants (0.83 percent) admitted to our neonatal intensive care units. The condition developed more than 1 week after birth in most infants. This group included most of the very low birth weight infants. Forty-one of the 42 infants had enteral feedings before the onset of enterocolitis, which developed within 72 hours from the start of feedings in 19 infants (45 percent). Twenty-nine patients (69 percent) underwent surgery. Mortality in this group was 38 percent overall and 28 percent in the infants considered salvageable at laparotomy. The interval from diagnosis to surgery was 24 hours or less in 65 percent of cases, emphasizing the fulminant nature of the disease in many patients. Three of the 14 patients who died underwent no surgery. Pneumoperitoneum was one of the initial radiologic signs in 10 patients (24 percent). The necrotizing enterocolitis observed was similar clinically to that reported by others. The strikingly low incidence of enterocolitis in the neonatal intensive care units in Oregon (0.83 percent) contrasts with the generally reported incidence of 3 to 8 percent in other neonatal intensive care units. We attribute the low incidence of necrotizing enterocolitis in our experience to delay of enteral feedings and reliance on prolonged peripheral or central total parenteral nutrition, or both, for nutritional maintenance of stressed or low birth weight infants.

Birth Weight↗

PubMed1980

Pediatric diaphragmatic hernias. An 11 year experience.

A retrospective study of 36 infants and children with diaphragmatic hernia was carried out. Mortality was confined to the group of patients identified between birth and 6 hours of life. Survivors appeared to be separable early in life from those who died on the basis of clinical status at birth measured by the Apgar, by ventilatory capacity of the lung reflected by carbon dioxide pressure and by acid base balance. Oxygenation, time from birth surgery, maternal factors, and labor and delivery appeared to play no role in survival. Hypoplasia of the lung reflected in low lung weights in those who died did not correlate with initial clinical status or blood gas data. Surgical adjuncts to reduction and closure of the hernia did not appear to have an effect on survival. Definition of patients at high risk of dying will permit critical application an evaluation of modes of treatment beyond those now used regularly in the care of these desperately ill infants.

Hernia, Diaphragmatic↗

PubMed1977

Fine structural changes in the gastro-intestinal tract of the hypoxic puppy: a study of natural history.

The present study demonstrates that a 2 hr period of sustained hypoxia results in a focally destructive process, a process which resolves by 5 days. That the changes described in earlier work are not overwhelming to the animal suggest that an early, focal, and reversible stage of the development of acute enterocolitis in the puppy can be described with the aid of electron microsocpy.

Animals↗

PubMed1977

Microcirculatory changes in the lung of the hypoxic and hypovolemic puppy: an electron microscope study.

The effect of systemic hypoxemia and hypovolemia on pulmonary fine structure was studied and compared in 12 Labrador puppies 6 days to 3 weeks old. Central venous and arterial pressures were monitored and arterial pH, PCO2 and PO2 recorded serially. In 4 puppies lung biopsies were taken after a two hour period of breathing 7% oxygen. Four other puppies were made hypovolemic by acute hemorrhage of 50% of the calculated blood volume and lung biopsies taken after one hour. Four control puppies were maintained under anesthesia for two hours, breathing an atmosphere of 20% oxygen before lung biopsies were taken. Both hypoxemia and hypovolemia resulted in similar pulmonary ultrastructural changes. These changes which occurred more frequently in areas where the air spaces and blood vessels were expanded, were characterized by aggregation of platelets and leucocytes in the vascular space, focal endothelial cell disruption, interstitial edema and type I epithelial cell discontinuities with exudation of plasma into the alveolar air spaces.

Animals↗

PubMed1976

Pulmonary fine structural changes in children with tissue hypoxia.

Six children have undergone lung biopsy for evaluation of fine structure. Four children demonstrated increased DAVO2 preoperatively and had marked ultrastructural changes in their lungs. Such changes appear to result from embolization of microthrombi or microaggregates to the lung from under-oxygenated tissue.

Adolescent↗

PubMed1976

Surgical treatment of late esophageal perforations.

The salvage of patients with late esophageal perforations is a formidable surgical undertaking. The basic objectives of surgical therapy should be: prompt debridement and control of sepsis by establishing an adequate, controlled route of decompression drainage, salvage of all viable and functional esophagus (except in massive disruptions with circumferential loss), adequate support of life control systems, and establishment of an appropriate alternate route for supportive alimentation. The method of treatment used in the group of patients reported here satisfies all these objectives. Our experience justifies further consideration of this technique in dealing with this catastrophic illness.

Adult↗

PubMed1975

Microcirculatory changes in the gastrointestinal tract of the hypoxic puppy: an electron microscope study.

Hypoxia and hypovolemia result in similar ultrastructural changes. These changes are characterized by aggregation of platelets and leukocytes in the vascular space, focal endothelial cell disruption, and appearance of increased amounts of perivascular edema, and loss of ultrastructural organization of the mucosal cell. These changes appear to relate to variations in blood flow to the mucosa of different areas of the bowel and to follow the distribution observed for necrotizing enterocolitis in the human infant.

Animals↗