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Biomedical subjects

S Lennquist

Publications and source records attributed to S Lennquist.

At least 19 recordsLinked to original sources
PubMed1994

Modulation of lung injury by platelet-activating factor antagonism in nonhypotensive porcine endotoxemia.

Endotoxemia was induced by intravenous infusion of Escherichia coli endotoxin in 18 anesthetized pigs in a dose of 36 micrograms/kg/hr. Nine pigs were pretreated with BB-882, a novel platelet-activating factor (PAF) antagonist, 33 mg/kg/hr, starting 30 min before endotoxin, and nine pigs received a similar volume of vehicle. Normotension was maintained with intravenous crystalloid resuscitation. Six pigs received only BB-882 and served as controls. Endotoxemia induced an acute transient 300% increase in pulmonary vascular resistance, identical in both groups. The initial increase was followed by a second, more gradual, rise in resistance, which was significantly attenuated by BB-882 (P < 0.01, repeated measurements ANOVA). Endotoxin-induced arterial deoxygenation and fall in lung/thorax compliance was not significantly altered by BB-882. Hematocrit was less in endotoxic pigs receiving BB-882 (P < 0.02). There were no significant changes compared to baseline in the control group. The results indicate that PAF is a minor determinant of early pulmonary dysfunction in nonhypotensive porcine endotoxemia.

Animals↗
PubMed1992

Pulmonary granulocyte accumulation is reduced by nebulized corticosteroid in septic pigs.

Nebulized beclomethasone dipropionate was administered to 14 anesthetized and artificially ventilated pigs at 6-hourly intervals after infusion of live S. aureus (BDP group). Changes in pulmonary activity from autologous granulocytes labeled with In-111 was detected externally for 12 (n = 8) to 44 h (n = 6). The changes were compared with those in ten pigs (12 h n = 7, 44 h n = 3) subjected to the same insults but given no corticosteroid (placebo group). Serial measurements of blood radioactivity, and cardiac output were performed in animals observed for 12 h. Corticosteroid-treated pigs showed a gradual decline in decay-corrected pulmonary In-111 activity. The placebo group displayed a more varied reaction, but most animals had an increased activity compared to the corticosteroid group. The difference between the groups was significant at 8 h (BDP-group 92% (88-98), placebo-group 107% (97-121), median (lower-upper quartiles), baseline = 100%. P < 0.01, U-test). Blood radioactivity and cardiac output did not differ significantly between the two groups. Nebulized corticosteroid thus diminished pulmonary granulocyte accumulation, which may be of value in the treatment of septic respiratory distress.

Aerosols↗
PubMed1992

Methylprednisolone improves pulmonary function and hemodynamics in experimental gram-positive septicemia.

It has been suggested that the effects of high-dose corticosteroid therapy (HDC) in gram-positive (G+) and gram-negative (G-) septicemia differ. As few data are available on HDC in G+ septicemia, pulmonary and cardiovascular function was studied for 44 hr in five anesthetized pigs subjected to brief infusion of live Staphylococcus aureus (approximately 10(11) cfu) followed by intravenous methylprednisolone (MP, 30 mg/kg) administered as a bolus every 8 hr. Comparisons were made with six septic pigs given no MP but otherwise identically managed. Six control pigs received no bacteria or MP. Infusion of bacteria induced identical transient pulmonary hypertension in both septic groups (52 +/- 7 mm Hg, mean +/- SD), but MPAP remained significantly lower in the pigs with MP (18 +/- 1 mm Hg vs. 30 +/- 9 mm Hg at 8 hr, P less than 0.05). MAP was better maintained in the MP group (107 +/- 9 mm Hg vs. 80 +/- 16 mm Hg at 8 hr, P less than 0.05). Pulmonary function also was less affected in the MP group at 8 hr, with significantly better maintenance of arterial oxygenation (13.5 +/- 1.2 kPa vs. 9.4 +/- 2.2 kPa, P less than 0.05) less venous admixture (11 +/- 6% vs. 34 +/- 23%, P less than 0.05) and superior lung-thorax compliance (29 +/- 5 ml/cm H2O vs. 15 +/- 5 ml/cm H2O, P less than 0.05). Five of five with MP survived, whereas two of six without MP survived (P = 0.045). MP thus attenuated pulmonary and hemodynamic abnormalities induced by S. aureus septicemia.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1992

Hyaluronan: relationship to hemodynamics and survival in porcine injury and sepsis.

BACKGROUND AND METHODS: Hyaluronan is a polysaccharide normally present in low concentrations in the blood, and is rapidly cleared from the blood by the liver. Increased plasma hyaluronan concentrations have been found in patients with sepsis. We studied changes in serum hyaluronan concentrations and their relationship to hemodynamics and survival in a 48-hr porcine model of injury and sepsis. RESULTS: Circulating hyaluronan concentrations increased to high values after induction of experimental sepsis (from mean baseline values of 242 +/- 26 [SEM] to mean maximum concentrations of 964 +/- 255 micrograms/L [p less than .01]) compared with controls (199 +/- 38 to 303 +/- 32 micrograms/L). A weak negative correlation between mean arterial pressure (MAP) and serum hyaluronan values was found (r2 = .47; p less than .01). Nonsurvivors had higher mean serum hyaluronan concentrations than survivors (603 +/- 147 vs. 285 +/- 43 micrograms/L [p less than .05]). CONCLUSIONS: Experimental sepsis is associated with an increase in serum hyaluronan values. The relationship between decreased MAP and increased serum hyaluronan concentrations could point to reduced liver perfusion as a cause. An association between high hyaluronan values and nonsurvival in sepsis is possible.

Analysis of Variance↗
PubMed1992

Intraoperative radionuclear 125I-labeled metaiodobenzylguanidine scanning of pheochromocytomas and metastases.

We developed a technique to assess the feasibility of intraoperative radionuclear detection of pheochromocytomas and their metastases. Thirteen patients were entered into the study: five control subjects with nonchromaffin adrenal tumors, eight with pheochromocytomas, and one of these patients showing bone metastasis. Each subject received thyroid blockade and an intravenous injection of 500 microCi (37 megabecquerels) 125I-labeled metaiodobenzylguanidine (MIBG) 3 days before surgery. In the five control subjects, adrenal tumor uptake never exceeded the liver or spleen uptake. One patient with a negative preoperative MIBG scan demonstrated no intraoperative uptake. Five patients with pheochromocytoma had positive preoperative scans and in one other patient preoperative scanning was not done. In each of these six patients intraoperative count ratio of pheochromocytoma/liver from 14:2 to 250:16 and pheochromocytoma/contralateral adrenal ratio from 60:1.5 to 60:16 was demonstrated. An intraoperative scan in one of these patients detected two small metastatic tumor deposits previously overlooked by the surgeon after removing a larger mass that had been localized by a preoperative 131I-MIBG scan. A negative preoperative scan in one patient was followed by an intraoperative scan demonstrating a bone metastasis with a ratio of metastasis/normal bone of 10:0.5. Specimen studies demonstrated a significant MIBG uptake ratio of tumor/plasma ranging from 95 to 667 (average 404 +/- 242) greater than in control subjects (average 25 +/- 41); in the patient with metastasis the uptake ratio of metastasis/normal bone reached 98.4. We conclude that intraoperative 125I-MIBG scanning might detect pheochromocytoma deposits overlooked by preoperative 131I-MIBG scans.

3-Iodobenzylguanidine↗
PubMed1991

Nebulized corticosteroid improves pulmonary function and outcome in experimental porcine septicemia.

Nebulized beclomethasone dipropionate was administered to six anesthetized and artificially ventilated pigs at 6-hourly intervals after infusion of live S. aureus (aerosol group). Changes in pulmonary mechanics, gas exchange and hemodynamics during an observation period of 44 h were compared with those in six pigs subjected to the same insults but given no corticosteroid (non-treatment group). Six pigs served as controls, without sepsis or aerosol, but with the same general management (control group). The septic insult induced an acute 3-fold increase in mean pulmonary artery pressure (MPAP) in the aerosol and non-treatment group. MPAP fell to near baseline levels in the aerosol group, but remained significantly higher in the non-treatment group. Mean systemic arterial pressure fell more in the non-treatment than in the aerosol group, reaching its lowest level at 32 h. Pulmonary function was less affected in the aerosol group, with significantly better maintenance of arterial oxygenation, lower venous admixture and superior lung-thorax compliance than in the non-treatment group. Survival was significantly improved in the aerosol group. In this porcine model of septicemia-induced adult respiratory distress syndrome, nebulized corticosteroid thus attenuated the development of respiratory failure.

Administration, Inhalation↗
PubMed1991

Preceding trauma lessens the degree of respiratory dysfunction in septicaemic pigs.

Ten anaesthetised and mechanically ventilated pigs were subjected to musculoskeletal trauma two hours before induction of septicaemia with live Staphylococcus aureus, 10(11) colony forming units (trauma/sepsis group). The effects on haemodynamic and pulmonary function were compared over a period of 44 hours with those on 11 pigs that were identically treated except that they were not subjected to the trauma (sepsis alone group). The induction of sepsis produced similar transient pulmonary hypertension in both groups (mean (SD) in the trauma/sepsis group 48 (5) mmHg compared with 51 (6) mmHg in the sepsis group). In the trauma/sepsis group the decline in lung/thorax compliance was significantly less pronounced at 8 and 20 hours; the arterial oxygen tension was significantly better maintained at 32 and 44 hours; and the haemodynamics were better preserved, with significantly lower mean pulmonary arterial pressures at 20 and 44 hours than in the sepsis group. In conclusion, musculoskeletal trauma preceding septicaemia significantly lessened the degree of ensuing pulmonary dysfunction. This effect could be the results of reduced autoinjury by immunocompetent cells responding subnormally, but these mechanisms require further study.

Animals↗
PubMed1990

Combined cervicothoracic approach in thymectomy for myasthenia gravis.

Thymectomy was performed for myasthenia gravis on 30 patients, using a new approach with a collar incision which gave full exposure of the retrothyroid space and was directly connected to a median sternotomy. The thymus was removed en bloc without pleural incision. There was no perioperative mortality and the only complications were transient respiratory insufficiency in two cases. The postoperative hospital stay was 3-9 (mean 5.8) days. The effect of thymectomy was evaluated after 2-8 years at the Department of Neurology, when changes in symptoms (stages I-IV) or medication (need for cholinesterase inhibitors) were registered. The total clinical improvement rate was 97%, with 3% of the patients improved three stages, 33% two stages and 60% one stage compared with the preoperative classification. Twenty patients (67%) were asymptomatic at follow-up and six (20%) also required no medication. The medication need was reduced in 70% of cases (mean reduction 42%). Our cervicothoracic approach resulted in the same rate of improvement as in studies using more extensive transsternal procedures, but the morbidity was lower, with no complications requiring prolonged hospital stay. The morbidity was also less than after only transcervical procedures aiming to perform total thymectomy--a prerequisite for maximal and lasting benefit from surgery. Moreover, as this cervicothoracic approach is simple and safe, it can be recommended as an option in the surgical management of myasthenia gravis.

Adolescent↗
PubMed1988

The role of aspiration cytology in the management of thyroid nodules.

In the hands of an experienced cytologist aspiration cytology is a safe and hitherto the best diagnostic tool in the evaluation of nodular thyroid lesions. In histologically verified case series 50-90% of confirmed thyroid cancers can be detected by aspiration biopsy, the sensitivity being dependent on sampling errors, microscopic misinterpretation and the variation in attitude towards indeterminate diagnosis in the decision for diagnostic surgery. The number of proven benign cases that are correctly identified as such by biopsy varies accordingly and approx. 75% (specificity). In comparison with imaging procedures, including those giving information of functional activity, the combined sensitivity and specificity rates of aspiration cytology come closest to the ideal discriminatory situation. In combination with case history and careful clinical examination, fine needle aspiration cytology is the best guidance for an optimal selection of patients for therapeutic or diagnostic surgery. Future development of sensitive markers for malignant degeneration will probably increase the selective power of this diagnostic technique.

Biopsy, Needle↗
PubMed1987

The thyroid nodule. Diagnosis and surgical treatment.

A definitive evaluation of different therapeutic approaches to patients with papillary and follicular thyroid carcinomas requires a prospective multicenter long-term study, with careful documentation of variations in histologic classification and all other factors that can possibly influence prognosis. Until such information is available, every patient with a thyroid nodule should be given the treatment that offers the best prospect for cure to the greatest possible number of patients; this treatment appears to be hemithyroidectomy for benign unilateral thyroid tumors and total thyroidectomy for carcinomas. These operations can be done safely by experienced surgeons without exceeding the morbidity or complication rate of less extensive treatments.

Adenocarcinoma↗
PubMed1987

High-energy phosphates and surface oxygen pressure fields in skeletal muscle after high-energy trauma.

The effect of a high energy missile trauma on energy metabolism and tissue oxygenation in uninjured parts of skeletal muscle was studied in anaesthetized pigs up to 72 hours after the trauma. High energy phosphates (HEP) were measured in muscle biopsies, and muscle tissue oxygenation was measured as muscle surface oxygen pressure fields by an oxygen electrode. In the traumatized group significantly decreased levels of HEP were found in spite of normal tissue oxygenation 72 hours after the trauma. In the control group both the HEP and the muscle tissue oxygenation were unchanged compared to the pretrauma situation. Decreased synthesis of HEP due to tissue hypoxia or inadequate nutrition could not account for the difference between the control and the trauma group. It was suggested that hypermetabolism induced by the high energy trauma caused increased utilization and thereby decreased concentrations of the HEP 72 hours after the trauma. It was also concluded that the general posttraumatic metabolic changes found in uninjured parts of the muscle tissue differed from the local changes of traumatized muscle described by other investigators, and therefore probably were caused by other mechanisms.

Adenosine Diphosphate↗
PubMed1987

The superior laryngeal nerve in thyroid surgery.

Injury to the external branch of the superior laryngeal nerve (ESLN) during thyroid surgery can have serious consequences. A strategy for perioperative identification and preservation of the ESLN was clinically evaluated after postmortem anatomic observations. These showed that 20% of ESLNs run distally through the pharyngeal constrictor muscle, which necessitates intramuscular dissection for identification in the area around the superior thyroid pole. In 23% of the ESLNs identifiable without intramuscular dissection (18% of the total), a course partly lateral to the superior thyroid artery and its branches implied definite risk of injury during division of the superior pole vessels. In the clinical series, 72% of the ESLNs were identifiable without intramuscular dissection, and 19% of these (14% of the total) were partly lateral to the superior thyroid artery. Only one patient had signs of ESLN injury postoperatively, probably caused by diathermy to an adjacent vessel. Perioperative identification of ESLN with dissection into the pharyngeal constrictor muscle (about 20% of cases) appears to be inadvisable, but identification of ESLN with other courses is important, as around 20% are highly vulnerable during division of the superior thyroid artery and its branches.

Adult↗