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Biomedical subjects

A Johnson

Publications and source records attributed to A Johnson.

At least 595 records · Page 33Linked to original sources
PubMed1981

Effects of different-size microemboli on lung fluid and protein exchange.

We examined the effects of embolization with different-size glass-bead microemboli on pulmonary transvascular fluid and protein exchange in the sheep lung lymph fistula preparation. Embolization with either 200- or 500-micron-diameter glass beads caused comparable increases in pulmonary vascular resistance, which were sustained for the duration of the study. The 200-micron beads increased pulmonary lymph flow (Qlym) and did not affect the lymph-to-plasma protein concentration ratio (L/P), whereas injection with 500-micron beads increased Qlym and decreased L/P. The latter changes were comparable to those observed after an increase in pulmonary microvascular pressure induced by left atrial hypertension, suggesting that the 500-micron beads increase the Qlym by raising the microvascular hydrostatic pressure. In contrast, the 200-micron beads increased the transvascular clearance of proteins to a greater extent, since L/P did not decrease as Qlym increased. These findings suggest that lung vascular permeability increases after embolization with smaller (200-micron) but not with larger (500-micron) emboli. The increased permeability after embolization with small beads may be due to transmission of the permeability-increasing substances to the downstream capillaries via the collateral pulmonary arteries. This would not occur after embolization with larger emboli if these obstructed the pulmonary arteries upstream from branching points of the collateral arteries. The ultrafiltration of protein-poor plasma after embolization with the 500-micron beads may reflect increased fluid filtration in unobstructed microvessels due to increase in the microvascular hydrostatic pressure.

Animals↗
PubMed1981

HLA-A2 antigen in schizophrenic patients with reversed cerebral asymmetry.

The frequency of HLA-A2 was examined in 32 black and 22 white schizophrenic patients separated into two groups according to whether they had normal or reversed cerebral hemisphere asymmetries as determined by computed tomography. The black patients with reversed asymmetry had a significantly greater frequency of HLA-A2 as compared to black patients with normal asymmetry and a black normal control group. There were no significant differences for any other A, B or C antigens. These findings also held when only the 22 black patients without evidence of brain atrophy were studied. The results for the white patients were in the same direction but did not reach statistical significance. These findings suggest that, at least for black schizophrenic patients, reversed cerebral asymmetry is associated with an increased frequency of HLA-A2.

Black or African American↗
PubMed1981

Immunologic evaluation in the prognosis of acute lymphoblastic leukemia. A report from Childrens Cancer Study Group.

Eight-hundred ninety-five previously untreated acute lymphoblastic leukemia (ALL) patients were entered on a protocol designed to provide results of selected immunologic tests. At diagnosis, delayed hypersensitivity tests with four antigens (tetanus, diptheria, candida, and SKSD), immunoglobulin levels, tests for serum inhibition to phytohemagglutinin-stimulated lymphocyte blastogenesis, and HLA-A, B, and C typing were performed. Although delayed lymphocyte blastogenesis have been reported previously to be abnormal in ALL, we did not find them to be associated with disease outcome. Thirty percent of the patients had reduced levels of one or more immunoglobulins. The frequency of remission was less in those patients with decreased IgG and IgA. IgA and IgM showed prognostic importance in remission duration, and all three fractions appeared to have prognostic significance for survival duration. Although none of the HLA types appeared to be associated with significantly increased or decreased success in remission induction, patients with antigens A28 or B12 and patients bearing lymphocyte A11/B35 had shorter remissions. our results indicate that the immunologic factors studied, hypogammaglobulinemia and certain HLA antigens may be related to disease control and outcome in ALL.

Adolescent↗
PubMed1980

The effect of different calorific doses of carbohydrate on nitrogen excretion after surgery.

The protein-sparing effect of different calorific regimens [0.025 MJ (6 kcal); 0.105 MJ (25 kcal); 0.167 MJ (40 kcal) per kg body weight per 24 h] of postoperatively infused glucose has been studied in 18 patients undergoing operations of intermediate severity. Carbohydrate infusion has a progressive nitrogen-sparing effect. However, the increased negative nitrogen balance associated with surgical stress could not be prevented completely.

Adult↗
PubMed1980

The serum sodium concentration after surgical operation: precision permits predictions.

In view of previous conflicting reports, the distribution of a water overload was investigated in 6 healthy volunteers. The fall in serum sodium was predictable from prior measurement of total body water (tritium) confirming that the induced hyponatraemia was dilutional. Using a standard intravenous fluid regimen, a prospective study for 6 days on 50 patients undergoing major abdominal surgery established a confidence band for change in serum sodium concentration. This band not only enables precise prediction of whether observed sodium values in patients are "normal' for that point in their postoperative course, but also demonstrates that changes are more prolonged than was at first thought. Their dilutional nature following uncomplicated surgery is supported by linear relationships between serum osmolality and serum sodium (s-Osm = 1.86 [s-Na+] + 18:74; (P < 0.001) and between observed and calculated osmolality (Obs-Osm = 0.97 [Calc-Osm] + 15.11; P < 0.001). More detailed investigation of 14 patients by isotope dilution provided independent evidence of dilutional change. This conclusion is additionally supported by lesser changes in patients on a more restricted fluid regimen. As a practical confirmation of the utility of this approach, departures from the simple dilutional relationships were observed in 7 critically ill patients whose postoperative course was complicated. In this group osmolal "gags' of 20-50 mosmol/kg were identified. Current standard postoperative fluid regimens cause dilutional changes; these are predictable and provide a yardstick for use in management of both the healthy and the ill surgical patient.

Adult↗
PubMed1980

Experience with day stay surgery.

Potential advantages of day stay surgery are cost saving, improved utilization of staff and hospital facilities, and reduction of stress for the paediatric patient and his family. The successful program requires careful case selection, full operating and anesthetic facilities and good follow-up. Day stay surgery was initiated at Royal Alexandra Hospital for Children in 1974. Experience is reviewed in relation to the total number and nature of surgical admissions and the daily utilisation of the facility. Utilization has markedly increased in the past 2 yr. Current practice is reviewed with regard to initial assessment, preparation for surgery and overall management during the day admission. Parental attitudes towards day stay surgery were evaluated indicating both the advantages and the problems encountered. These related mainly to insufficient information, transport difficulties and afternoon operations. Recommendations for improving the day stay service are discussed with special reference to: (1) communication with the parents as to adequate pre-operative explanation, revision of the day stay information pamphlet and improved distribution, and clear postoperative instructions, (2) the timing of operations, and (3) transport and parking facilities.

Ambulatory Surgical Procedures↗
PubMed1980

An assessment of urodynamic examination in incontinent women.

Urodynamic investigation was performed in 100 consecutive incontinent women. The clinical diagnosis was confirmed in only 65 women and management was significantly altered in 31 women. Pressure-flow studies should precede, whenever possible, the treatment of incontinent patients.

Female↗
PubMed1980

Cryptogenic fibrosing alveolitis and lung cancer.

Lung cancer was found in 20 (9.8%) of 205 patients with cryptogenic fibrosing alveolitis (CFA) or 12.9% of the 155 patients in this series followed to death. An excess relative risk of lung cancer of 14.1 was found in patients with CFA compared to the general population of comparable age and sex, allowing for the lengths of follow-up of the CFA patients. The relative risk for male smokers was (observed/expected) 15+1.06 = 14.2, and for female smokers (O/E) 2/0.3 = 6.7. Only one male and one female non-smoker had lung cancer. These data suggest that there is an excess risk of lung cancer not wholly accounted for by age, sex, or smoking habit. The distribution of histological types was not obviously different from that found in lung cancer without pulmonary fibrosis. Large opacities suggestive of lung cancer were present at the time of first hospital attendance for symptoms relating to CFA in four of the 20 patients. Finger clubbing was present in 19 (95%) compared with 116/185 (63%) of those so far not developing cancer. There were no other clinical differences at presentation. In particular, cancer was not found especially in those with longer survival from the onset of symptoms of CFA or with a greater initial radiographic change.

Adolescent↗
PubMed1980

Effect of defibrinogenation on lung water accumulation after pulmonary microembolism in dogs.

We determined the effects of chronic fibrinogen depletion on the development of pulmonary edema after pulmonary microembolization. Dogs were defibrinogenated with a purified fraction of Malayan pitviper venom (ancrod). Studies were made in four groups: control untreated (group I); emboli untreated (group II); control defibrinogenated (group III); and emboli defibrinogenated (group IV). Fibrinogen decreased (P < 0.05) from 570.6 +/- 100.9 to 5.3 +/- 3.1 mg/100 ml in the ancrod-treated groups. Pulmonary arterial pressure was increased to similar levels in both embolized groups after infusion of 100-mug-diam nonsiliconized glass beads into the right atrium. Pulmonary vascular resistance and pulmonary perfusion pressure were initially increased to similar levels in both embolized groups, but by 75 min postembolization (PE) both parameters were higher (P < 0.05) in the defibrinogenated group. The extravascular lung water-to-bloodless dry lung ratio at 75 min PE of 4.53 +/- 0.24 in group II was greater than the control value of 2.84 +/- 0.22 in group I (P < 0.05). In contrast, the extravascular lung water-to-bloodless dry lung ratio of 3.64 +/- 0.09 in group IV was not different from the control value of 3.38 +/- 0.04 in group III, but was less than 4.53 +/- 0.24 in group II (P < 0.05). Therefore, chronic defibrinogenation in dogs prevented the development of pulmonary edema after pulmonary microembolization. The protective effect may be due to inhibition of the increase in lung vascular permeability and to a time-dependent reduction in pulmonary microvascular pressure.

Animals↗
PubMed1980

Effect of granulocytopenia on extravascular lung water content after microembolization.

We studied granulocyte entrapment in the lung after pulmonary microembolization to see if it contributes to the increase in extravascular water content. The lungs were embolized by intravenous injection of nonsiliconized glass beads (100 micrometers in diameter) in normal dogs and dogs made granulocytopenic by daily injections of hydroxyurea. Hydroxyurea did not significantly alter the platelet and fibrinogen concentrations. Control and treated dogs were embolized to the same degree, which resulted in similar increases in pulmonary arterial pressure and pulmonary vascular resistance. The extravascular lung water content/bloodless dry lung weight (W/D) ratios in the control and treated groups after embolization were compared with the W/D ratios in the control and treated nonembolized groups, respectively. The W/D ratio increased from the value of 2.84 +/- 0.22 ml/g in the control group to 4.54 +/- 0.19 ml/g at 75 min after embolization (60% increase) (p < 0.05). However, the W/D ratio in the control-granulocytopenic group of 3.54 +/- 0.19 ml/g was not significantly different from the value of 4.09 +/- 0.27 ml/g in the granulocytopenic group after embolization. Because embolization after granulocytopenia produced only a 16% increase in the extravascular lung water content, compared with a 60% increase in the treated group after the same degree of embolization, the results suggested that granulocyte entrapment in the lung after microembolization contributes to the development of pulmonary edema.

Agranulocytosis↗