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Biomedical subjects

S Lennquist

Publications and source records attributed to S Lennquist.

At least 91 records · Page 5Linked to original sources
PubMed1982

Traumatically induced hypophosphataemia in anaesthetized pigs.

Clinical studies in severely injured patients have regularly shown hypophosphataemia probably directly related to the humoral response to trauma. In this study 72 anaesthetized pigs were exposed to a standardized missile trauma to find out whether the same type of change could be induced in an experimental animal as far as possible in the absence of other factors known to cause hypophosphataemia. The serum phosphate, calcium, and albumin concentrations and the fractional excretion of phosphate were recorded for 72 hours after inflicting the injury. The fall in serum phosphate after trauma follows a biphasic pattern, with a rapid drop immediately after the injury, a brief increase, and then a gradual slow decrease with a minimum at the end of the experimental period. This decrease was not caused by glucose infusion or phosphaturia due to haemodilution and increase in extracellular volume. The results support the hypothesis that hypophosphataemia in the posttraumatic period is caused by the humoral response to trauma. A new experimental model has been developed for the study of posttraumatic metabolic events.

Animals↗
PubMed1982

Changes in serum phosphate and calcitonin concentrations during elective surgery of the knee.

Hypophosphataemia in connection with surgical trauma is most commonly ascribed to parenteral nutrition, glucose infusion, or haemodilution. We have earlier shown that patients with severe burns develop hypophosphataemia irrespective of such causes, and have introduced the theory that hypophosphataemia can result from the humoral response to trauma. In the present work, 10 otherwise healthy patients undergoing elective surgical treatment of old knee-ligament injuries were examined pre-, per-, and postoperatively with regard to phosphate, calcium, and magnesium homeostasis and hormones regulating this (parathyroid hormone, calcitonin, catecholamines). During operation we noted a significant and rapid fall in serum phosphate concentration, accompanied by increased secretion of calcitonin and catecholamines and a significant fall in serum magnesium. Unchanged fractional and total urinary phosphate excretion indicated that the fall in serum phosphate concentration was mainly due to prerenal causes.

Adolescent↗
PubMed1982

Primary fracture immobilization as a method to prevent post-traumatic pulmonary changes- an experimental model.

Post-traumatic pulmonary insufficiency or "respiratory distress syndrome" (RDS) is one of the most feared complications of severe trauma. The aetiology is probably multifactorial, and is obscure. Although modern treatment has reduced the mortality, there is no certain way of preventing the syndrome. The aim of the investigation was to develop an experimental model on anaesthetized pigs subjected to trauma and folllowed up for 3-4 days, still under anaesthesia, the repeated lung X-rays and post-mortem naked-eye and histological examination of lung tissue. 26 pigs were used. 12 (Group I) were subjected to missile trauma of a limb, with a fracture that was left without immobilization. 10 were treated similarly but with immobilization of the fracture (Group II). Four control animals were prepared and observed under anaesthesia but no trauma was inflicted (Group III). In Group I, all but two developed, 10-70 h after the injury, roentgen and morphological changes identical to those seen in patients with clinically documented RDS. No such changes were seen in the controls or in Group II. With our experimental model it seems possible to induce in experimental animals roentgen and morphological changes corresponding to RDS in man. The method provides new means of studying the mechanisms behind and the effects of different forms of treatment in RDS. The results also support the hypothesis that early immobilization of fractures is an important step in preventing RDS.

Animals↗
PubMed1979

Hypophosphatemia in severe burns. A prospective study.

In 33 severely burned patients, who were followed for two weeks after injury, a transient hypophosphatemia was registered with the decrease in serum phosphate occurring on the second to tenth day after injury. When a previous retrospective study was combined with the present one, there were 50 patients in all. Seven patients died and, of these, five showed very low values of serum phosphate (S-P) at the time of their death. Simultaneous reduction of urinary phosphate excretion indicates that the depletion of phosphate is mainly prerenal. However, studies of fractional excretion of phosphate demonstrates that renal losses of phosphate might contribute to the hypophosphatemia. A remarkable finding was a general, marked rise in serum calcitonin (S-h-CT). The relationship between the rise in S-h-CT, the increased catecholamine secretion and the hypophosphatemia remains to be further clarified.

Adolescent↗
PubMed1977

Hypophosphataemia in severe burns.

A retrospective study was made of 17 severely burned patients with special reference to serum and urinary phosphate. A lowering of the serum phosphate level was regularly recorded between the 3rd and 9th day. The lowest mean value of serum phosphate of the group was 0.57 +/- 0.2 (S.D.) mmol/l (normal range 0.8-1.5 mmol/l) occurring on the 5th day after the accident. Serum phosphate then returned to normal levels in all the patients except three, who died. These three were among the four patients who showed the lowest serum phosphate values, less than 0.32 mmol/l, and their deaths coincided with the recording of these low values. The phosphate depletion seemed to be of prerenal origin. Hypophosphataemia may be of significance in the fatal outcome in some of the patients with severe burns.

Adult↗
PubMed1976

Uroliathiasis with primary hyperparathyroidism. A one-year screening.

A one-year material of 290 patients with clinically verified urolithiasis was screened for primary hyperparthyroidism, by X-ray examination, analysis of calculi, plasma calcium and phosphate, plasma parathyroid hormone and a clinical history examination. Primary hyperparathyroidism was found in 10 patients, 8 with adenomas and 2 with hyperplasia. The results suggest that with the present policy of investigation, there is a considerable underdiagnosis of parathyroid changes in patients with urolithiasis. An interesting finding was the distribution of plasma calcium concentrations in this material, which indicates that patients with urolithiasis have a generally higher lever of plasma calcium than others.

Adenoma↗
PubMed1976

Incidence and nature of horse-riding injuries. A one-year prospective study.

A prospective one-year study of horse-riding accidents was performed in an area with a very high frequency of amateur riding. Totally 174 patients with riding injuries were registered--66% children--making an incidence of only 0.7 per thousand riding occasions. However, many of these injuries were of a severe nature, one leading to death and 27 of the patients reporting persisting symptoms at follow-up one year after the accident. Eleven per cent of the accidents lead to cerebral injuries and 44% to fractures, mainly of the upper extremities. Eleven per cent required hospitalization and 17% operation under general anaesthesia. Clarification of the circumstances concerning the accidents indicated that many of the severe injuries could probably have been avoided by use of better safety equipment.

Adolescent↗
PubMed1975

Urinary excretion of hydroxyprolines in man under the influence of cold.

Urinary hydroxyproline excretion was studied in human subjects exposed to cold stress and was related to urine flow and tubular reabsorption of calcium and phosphate. The results indicate the occurrence of a calcium release from the bones, which does not seem to be caused by changed activity or immobilization. The cold-induced changes--calcium excretion, dehydration, and demineralization - are the same as those reported under space-flight conditions. Furthermore, it has also been possible to induce a similar response with psychological stress agents. These findings, together with recent observations on renal stone formation and hyperparathyrodism, indicate that different types of stress might have a direct influence on calcium homeostasis, possibly mediated by the adrenergic nervous system.

Adult↗
PubMed1975

The significance of local malignant lesions of the neck diagnosed accidentally during parathyroid exploration.

Three cases are presented in which strictly localized, malignant lesions in reticuloendothelial or mesenchymal tissue of the neck with varying degrees of differentiation were diagnosed accidentally during parathyroid exploration. No signs of metastatic dissemination or primary tumour with other localization were found. In all three cases, the identified changes were removed and a careful follow-up has not hitherto indicated that further treatment in these cases were necessary.

Adenocarcinoma, Papillary↗
PubMedDate not supplied

Exposure to chlorine gas: effects on pulmonary function and morphology in anaesthetised and mechanically ventilated pigs.

We have examined the effects of chlorine gas inhalation (110 and 140 ppm) on cardiovascular and pulmonary function in nine anaesthetised and mechanically ventilated pigs. Four additional pigs, which were similarly treated but not exposed to gas, served as controls. Severe pulmonary dysfunction developed when the animals were exposed to 100 l of 140 ppm chlorine gas for 10 min. Five of six animals died within 6 h of exposure. This dose induced a rapid drop in arterial oxygen tension (P < 0.001 compared with controls, ANOVA), a biphasic decline in lung compliance (P < 0.001) and a gradual increase in pulmonary vascular resistance (P < 0.001) that eventually caused a significant reduction in cardiac output (P < 0.05). Microscopic examination showed sloughing of the bronchial epithelium and early infiltration with leukocytes, but largely intact alveoli. The sequence of events and the microscopic appearance suggested that the initial stage of pulmonary dysfunction (the first 1 or 2 h) was the result of mismatching of ventilation and perfusion. This was followed at a later stage by interstitial oedema and migration of immunocompetent cells into the tissue. We conclude that exposure to 100 l of 140 ppm chlorine gas induces a severe stereotypic lung injury with high mortality within 6 h in this anaesthetised animal model.

Administration, Inhalation↗
PubMedDate not supplied

Human parathyroid blood supply determined by laser-Doppler flowmetry.

The blood supply of 53 normal human parathyroid glands was studied with laser Doppler flowmetry in 45 patients undergoing operations on the thyroid and parathyroid glands. The inferior and superior thyroid arteries and other vessels that might supply the parathyroid glands were occluded so their contribution to parathyroid perfusion could be studied. Occlusion of the main trunk of the inferior thyroid artery resulted in a reduction of blood flow by one-third, and a similar reduction was obtained after occlusion of the superior thyroid artery. The results demonstrate that the blood supply to the parathyroid glands is not as dependent on the inferior thyroid artery as has previously been suggested but that other routes of blood supply may be equally or, in some cases, even more important.

Arteries↗