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Biomedical subjects

R Nesbakken

Publications and source records attributed to R Nesbakken.

At least 19 recordsLinked to original sources
PubMed1986

Volumes of pituitary adenomas related to hormone production, duration of symptoms and postoperative outcome.

In the period from December 1978 to February 1986, 292 patients with pituitary adenomas were operated transsphenoidally. We measured tumor volumes from CT scans and pneumoencephalograms. Tumor volumes varied from 0.5 to 160 cm3. The duration of the clinical history varied from 6 months to 24 years. All pituitary hormones were recorded pre- and postoperatively in each patient. We found a positive correlation between tumor size and duration of clinical symptoms, both in hormone producing (active) and non-producing (inactive) adenomas. Among the prolactin and growth-hormone producing adenomas there was also positive correlation between tumor size and hormone levels: small and medium sized hormone producing adenomas (volume 6 cm3 or less), showed normalization of the preoperatively increased hormone levels after surgery. In patients with hormone producing pituitary adenomas larger than 6 cm3, we still found elevated serum prolactin or serum growth-hormone levels postoperatively. This indicates that the largest tumors could not be completely removed surgically. Pituitary tumors should be operated before they reach a volume of 6 cm3. If non-surgical treatment is initiated, the patient has to be closely followed with computed tomography.

Adenoma↗
PubMed1985

Combined modality treatment of operated astrocytomas grade 3 and 4. A prospective and randomized study of misonidazole and radiotherapy with two different radiation schedules and subsequent CCNU chemotherapy. Stage II of a prospective multicenter trial of the Scandinavian Glioblastoma Study Group.

A prospective and randomized trial has been performed in order to evaluate combined modality therapy in patients with astrocytomas grade 3 and 4. Follow-up information is available on 244 patients. One half of the series received radiation therapy twice a week (40.00 Gy/5 weeks), the other half five times a week (50.00 Gy/5 weeks). Misonidazole 1.2 g/m2 was given orally to one half of the patients in the first radiation treatment group 3 1/2 to 4 hours before the treatment. The other half received placebo. The second radiation treatment group was also divided in two halves, one receiving 0.48 g/m2 misonidazole and the other placebo 3 1/2 to 4 hours before radiation. The randomization also included a subdivision of the material into eight groups of which four were given CCNU and four no chemotherapy, beginning 3 months after operation. The dose of CCNU was 120 mg/m2 body surface every 6 weeks. All eight treatment groups showed practically identical periods of median survival, and no statistically significant differences were observed with regard to performance status, side effects, or complications. Another dosage and timing of misonidazole administration in relation to the irradiation schedule, and a consideration of effects of concomitant drugs like dexamethasone and phenytoin are discussed.

Actuarial Analysis↗
PubMed1984

The effect of high dose barbiturate decompression after severe head injury. A controlled clinical trial.

Treatment resistant intracranial hypertension after severe head injury has a very high mortality with conventional therapy such as hyperventilation and mannitol infusions. In this report, we describe the use of large doses of thiopental as a means of treating such swelling. From a consecutive series of 107 severe head injuries with a Glasgow Coma Score (GCS) of 6 or below, we selected all patients below 40 years age with a progressive increase in intracranial pressure (ICP) to 40 mm Hg. The first 16 patients (mean age 20 years, mean GCS 4.3) were treated with deep barbiturate coma and hypothermia (32-35 degrees Celsius) until stable lowering of ICP was achieved. The next 15 patients received conventional intensive care and were in other respects very similar to the barbiturate group (mean age 26, mean GCS 5.2). After 9-12 months the outcome was classified according to the Glasgow Outcome Scale (GOS). Therapy with barbiturate coma resulted in 6 good/moderate outcomes, 3 severe and 7 dead/vegetative. Conventional treatment resulted in 2 good/moderate outcomes and 13 dead/vegetative. This is a highly significant difference and cannot easily be explained by more severe injuries or complications in the conventional group. Superior control of ICP was achieved by large doses of thiopental and the final outcome was better.

Adolescent↗
PubMed1981

Combined modality therapy of operated astrocytomas grade III and IV. Confirmation of the value of postoperative irradiation and lack of potentiation of bleomycin on survival time: a prospective multicenter trial of the Scandinavian Glioblastoma Study Group.

In a controlled, prospective, randomized investigation, started in 1974, 118 patients with supratentorial astrocytoma Grade III--IV were divided into three groups. Groups 1 and 2 received 45 Gy postoperatively to the whole supratentorial brain. Bleomycin in 15-mg doses and a total dose of 180 mg or placebo was given intravenously three times a week, one hour prior to radiotherapy, during weeks 1, 2, 4 and 5. Group 3 received conventional care but no radiotherapy or chemotherapy. Median survival rates of patients were 10.8 months in Groups 1 and 2, and 5.2 months in Groups 3, a statistically significant difference. With regard to performance, the patients in Group 3 deteriorated faster than patients in Groups 1 and 2. Bleomycin had no positive or negative influence on survival.

Adult↗
PubMed1979

Plasma acetate concentrations during canine haemorrhagic shock.

Acetate, pyruvate, lactate and NEFA concentrations, as well as acid-base-parameters were followed during bleeding, stable hypotension and re-infusion in five dogs. Mean arterial blood pressures were kept at 30 mmHg during the shock phase. An increase in acetate concentrations (P less than 0.01) was found in arterial as well as in venous plasma samples. The maximal mean acetate concentration was 0.19 mmol/l (during reinfusion) as compared to 0.06 mmol/l prior to bleeding. There was no difference between arterial and inferior caval venous concentrations. A definite correlation (r = 0.81, P less than 0.02) was found between blood pyruvate and plasma acetate concentrations. There was no correlation between plasma glucose or NEFA and acetate concentrations or between blood excess lactate and plasma acetate. The plasma acetate accumulation was negligible compared to the concomitant lactate accumulation (1:60), and did not contribute to the metabolic acidosis of shock. The correlation between acetate and pyruvate concentrations may indicate that pyruvate is the main substrate of acetate production in hypovolemic shock.

Acetates↗
PubMed1979

Utilization of exogenous acetate during canine haemorrhagic shock.

Plasma acetate and lactate, as well as acid-base-parameters were followed during acetate (dogs I-V) or lactate (dogs VI-X) loading during stable hypotension (mean arterial blood pressure 30 mmHg). Acetate or lactate were infused at a constant rate of 4 mmol/kg/h as 0.5 mol/l solutions (50% as the sodium salt, 50% as the free acid) without simultaneous treatment of the volume deficit. The acetate metabolizing capacity was well preserved even in profound haemorrhagic shock. The actual loads were rapidly removed, while the equivalent lactate loads caused progressive accumulation of the lactate ion. Acetate loading did not aggravate the lactic acidosis, and the acid-base-parameters showed a more favourable development during acetate loading than during lactate loading. Acetate may thus be given during haemorrhagic shock without the same risk of accumulation that is carried by the equivalent amounts of lactate.

Acetates↗
PubMed1979

Acetate production and substrate availability in the dog.

Arterial plasma acetate, glucose and NEFA concentrations were measured during loading with glucose/insulin and fat emulsion/heparin, and during epinephrine and norepinephrine stimulation in dogs. The expected alterations in glucose and NEFA concentrations were found. Acetate concentrations were not influenced, and remained constant in all experiments. Since acetate removal from the body pool is mainly concentration dependent, it may be concluded that acetate production was constant under the conditions described. "Overflow disposal" of AcSCoA to yield free acetate in cases of high rates of AcSoA-production does not occur as long as the Krebs cycle is intact.

Acetates↗