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Biomedical subjects

E Helseth

Publications and source records attributed to E Helseth.

At least 19 recordsLinked to original sources
PubMed2003

Effects of 0.5 and 1.0 MAC isoflurane, sevoflurane and desflurane on intracranial and cerebral perfusion pressures in children.

BACKGROUND: Isoflurane has been a commonly used agent for neuroanesthesia, but newer agents, sevoflurane and desflurane, have a quicker onset and shorter emergence from anesthesia and are increasingly preferred for general pediatric anesthesia. But their effects on intracranial pressure (ICP) and cerebral perfusion pressure (CPP), especially in pediatric patients with already increased ICP, have not been well documented. METHODS: We studied 36 children scheduled for elective implantation of an intraparenchymal pressure device for 24 h monitoring for suspected elevated ICP. After a standardized intravenous anesthesia, the patients were moderately hyperventilated with 60% nitrous oxide (N2O) in oxygen. The patients were then randomized to receive 0.5 and 1.0 MAC of isoflurane (Group I, n = 12), sevoflurane (Group S, n = 12) or desflurane (Group D, n = 12) in 60% N2O in oxygen. Respiratory and hemodynamic variables, ICP and CPP were recorded at baseline and after exposure to a target level of test drug for 10 min or until CPP fell below 30 mmHg (recommended lower ICP level is 25 mmHg in neonates, rising to 40 mmHg in toddlers). RESULTS: When comparing baseline values with values at 1.0 MAC, mean arterial pressure (MAP) decreased (P < 0.001) in all groups, with no differences between the groups. ICP increased (P < 0.001) with all agents, mean +2, +5, and +6 mmHg in Group I, S and D, respectively, with no differences between the groups. Regression analyzes found no relationship between baseline ICP and the increases in ICP from baseline to 1.0 MAC for isoflurane or sevoflurane. However, increased baseline ICP tended to cause a higher ICP increase with 1.0 MAC desflurane; regression coefficient +0.759 (P = 0.077). The difference between regression coefficients for Group I and Group D were not significant (P = 0.055). CPP (MAP-ICP) decreased (P < 0.001) in all groups, mean -18, -14 and -17 mmHg in Group I, S and D, respectively, with no significant difference between the groups. CONCLUSIONS: 0.5 and 1.0 MAC isoflurane, sevoflurane and desflurane in N2O all increased ICP and reduced MAP and CPP in a dose-dependent and clinically similar manner. There were no baseline dependent increases in ICP from 0 to 1.0 MAC with isoflurane or sevoflurane, but ICP increased somewhat more, although statistically insignificant, with higher baseline values in patients given desflurane. The effect of MAP on CPP is 3-4 times higher than the effect of the increases in ICP on CPP and this makes MAP the most important factor in preserving CPP. In children with known increased ICP, intravenous anesthesia may be safer. However, maintaining MAP remains the most important determinant of a safe CPP.

Anesthetics, Inhalation↗
PubMed2001

Neurosurgical treatment of meningiomas in children and young adults.

OBJECT: We studied the frequency, functional outcome, association with neurofibromatosis (NF) and relapse in patients operated on for meningiomas at age 0-20 years in three Norwegian centers between 1972 and 1999. METHODS: Information was collected by examining case notes and histology records, conducting telephone interviews and performing new radiological investigations. Twenty-seven patients were identified. Five had NF, and all 5 developed multiple tumors. In non-NF patients, relapse occurred in 2 out of 19 who underwent total tumor resection, and in all 3 whose surgery was non-radical. There was 1 postsurgical death, and no other major complications. Most patients had few complaints or none at all resulting from their previous tumor or treatment. CONCLUSIONS: Meningiomas without NF have a good prognosis in children and young adults if the tumor can be removed radically. However, relapse can occur many years after the primary operation.

Adolescent↗
PubMed2001

[Resection of malignant tumors involving the anterior cranial fossa].

BACKGROUND: The craniofacial approach has greatly facilitated resections of tumours involving the base of the anterior cranial fossa when compared to either the transcranial or transfacial approach alone. MATERIAL AND METHODS: This approach was used in 11 patients with malignant tumours localized to the ethmoid sinus, orbit and bone or soft tissue of the base of the anterior part of the skull. By combining a low frontal or frontolateral craniotomy with resection of the facial skull, en bloc resections were accomplished. A frontogaleal periostal flap or a muscle flap from the temporal muscle was used to replace resected bone and to seal the skull base. RESULTS: There were no peri- or postoperative deaths. One patient died due to local recurrence, one patient is alive with residual tumour six years after surgery, and one is reoperated due to local recurrence. In addition one patient developed recurrence of a previously treated tumour of the maxillary sinus. Two patients developed meningitis and one pneumocephalus postoperatively. One patient has partial loss of vision and two patients underwent dacryocystorhinostomy due to epiphora. INTERPRETATION: The planning and execution of this type of surgery requires close interaction in an interdisciplinary team, in particular between neurosurgeon and head and neck surgeon.

Adolescent↗
PubMed2001

Choroid plexus tumors in children and young adults: report of 16 consecutive cases.

Choroid plexus tumors are rare intraventricular tumors, and they represent 2-4% of brain tumors in children. This single-institution retrospective study involves 16 consecutive choroid plexus tumors: 13 papillomas and 3 carcinomas. Tumor locations were the lateral ventricles in 13 cases, the third ventricle in 2 cases and the fourth ventricle in 1 case. The mean age at presentation was 3.1 years. Two patients died of perioperative blood loss. Five-year survival was 85% with papillomas and 33% with carcinomas. None of the papillomas recurred after total tumor resection, and the functional outcome in long-term survivors after papilloma surgery was excellent in 92% of the cases. Two of the carcinoma patients had disseminated disease. Fifty percent of the patients had persistent hydrocephalus after tumor resection, and these required cerebrospinal fluid diversion.

Adolescent↗
PubMed2001

Ependymoma in children and young adults (0-19 years): report of 25 consecutive cases.

The objective of this retrospective study was to evaluate the relative effect of surgery and radiotherapy (RT) on the survival of 25 consecutive children and young adults treated for ependymoma [18 in the posterior fossa (PF), 2 in supratentorial locations (ST) and 5 in intraspinal locations (IS)]. Five-year survival rates for patients with PF, ST and IS tumors were 28%, 0% and 100%, respectively. Total tumor resection was a positive prognostic factor in the case of PF tumors. No patients with subtotal removal of a PF tumor survived for longer than 5 years. The effect of RT on survival of patients with PF ependymomas in this series was uncertain. No patients with PF ependymoma had disseminated disease at diagnosis, and all tumor recurrences were local. Based on these observations, we see no indications for craniospinal RT of PF ependymomas, except in rare cases of disseminated disease. If RT is given, it should only be targeted to the tumor site. The two patients with ST ependymoma died within 3.8 years after primary treatment. Our series of ST ependymomas does not allow any specific treatment recommendations. One patient with IS ependymoma was cured by surgery alone. Four patients with IS ependymoma had documented residual tumor after surgery. RT induced remission in these patients. For IS ependymomas we recommend no RT if total tumor removal can be documented. In patients with subtotal removal of IS ependymomas local RT is effective and should be given.

Adolescent↗
PubMed2001

Assessment of intracranial pressure volume relationships in childhood: the lumbar infusion test versus intracranial pressure monitoring.

OBJECT: This study was undertaken to compare the results of two tests that are widely used to assess intracranial pressure-volume relationships in children: the lumbar steady state infusion test providing information about the resistance to cerebrospinal fluid (CSF) outflow (Rout), and continuous intracranial pressure (ICP) monitoring. METHODS: The study included 28 children aged 5-91 months, on whom both tests were performed. The median duration between the tests was 1 month. With the child in general narcosis, the lumbar CSF pressure was recorded before and during infusion of artificial CSF, and the Rout was calculated on the basis of the opening (Po) and plateau (Pp) pressures (Rout=Pp-Po/infusion rate). ICP was recorded every 5 s using a computer-based system. CONCLUSIONS: We found no significant correlation between Rout and mean ICP asleep. There were no significant relationships between abnormal mean ICPs during sleep (defined as either 10 or 15 mmHg) and abnormally high Rout values (defined as either 10 or 12 mmHg/ml/min), and no significant relationships between abnormally high Rout values (10 or 12 mmHg ml(-1) min(-1)) and the presence of abnormal ICP elevations (defined as either 20 or 25 mmHg and lasting 5 min). Therefore the calculation of Rout by the infusion test performed on children under general anesthesia gave no reliable prediction of abnormal ICP.

Cerebrospinal Fluid Pressure↗
PubMed2001

Changes in intracranial pressure after calvarial expansion surgery in children with slit ventricle syndrome.

The effect of calvarial expansion on symptom relief and intracranial pressure (ICP) in three children with slit ventricle syndrome (SVS) and intracranial hypertension despite a functioning ventricular shunt is reported. These children presented with a clinical picture of SVS, accompanied by slit-like ventricles on cranial computer tomography scan and intracranial hypertension. Calvarial expansion was performed by mans of an anterior approach in one case and a posterior approach (modified tiara plastic) in the other two cases. After calvarial expansion, symptoms of intracranial hypertension were abolished in one case and markedly reduced in two cases (observation period 25-36 months). Comparison of ICP before and after surgery was performed by means of new software (Sensometrics Pressure Analyser, version 1.2) that revealed a significant reduction in the number of abnormal ICP elevations after surgery. The results were not accompanied by changes in the size of the cerebral ventricles. This study demonstrates that in children with SVS and intracranial hypertension despite a functioning shunt, calvarial expansion may reduce ICP and produce long-lasting symptom relief. In these cases, we suggest that intracranial hypertension was caused by compromised intracranial volume.

Child↗
PubMed2000

[Metotopic craniosynostoses].

BACKGROUND: Premature closure of the metopic suture leads to inhibited growth of the frontal bones, producing a keel-shaped forehead (trigonocephaly). Simple metopic synostosis is usually sporadic. Trigonocephalic patients account for 8-16% of the referrals to craniofacial centers, with a marked male predominance. Intracranial pressure (ICP) may be increased, whereas shunt-dependent hydrocephalus is infrequent. Infrequently, patients have intra- or extracerebral anomalies; one third have varying degrees of neuropsychological problems. The treatment is primarily surgical. MATERIAL AND METHODS: We present two patients who during infancy developed increasingly keel-shaped foreheads, retruded orbital rims, increased biparietal diameter and close-set eyes (hypothelorism). Both had raised ICP, but normal psychomotoric development. They were operated using radical fronto-orbital surgical remodelling. RESULTS: Recovery was uneventful. Three months post-operatively, they had pleasing cosmetic results with no symptoms of increased ICP. INTERPRETATION: Where metopic craniosynostosis is suspected, the infant should be examined clinically with palpation of fontanelles and sutures, evaluated with respect to the shape and development of the facial skeleton, as well as by X-ray of the skull sutures. Radical fronto-orbital surgical remodelling gives a stable correction of the craniofacial deformity and generally a satisfactory cosmetic result.

Cephalometry↗
PubMed2000

[Distraction osteogenesis--a new therapeutic principle in complex craniofacial synostosis].

BACKGROUND: Surgical treatment of syndromal craniofacial synostosis consists of combined neurosurgical and maxillofacial reconstructions of the neurocranium and midface. Patients often need several operations if they are to achieve a functionally and cosmetically good result. This is, in part, due to limitations in the amount of "acute" correction possible peroperatively with conventional surgical technique. MATERIAL AND METHODS: In recent years, a new method called distraction osteogenesis has been developed, by which the skeletal elements are gradually advanced. The method is based upon a process whereby the reparative callus formed between the surfaces of two bone segments is subjected to traction. This leads to new bone formation parallel to the vector of distraction. RESULTS: Distraction osteogenesis allows for greater mobilizations, hence the promise of fewer reoperations. INTERPRETATION: The method seems to be a valuable treatment modality in syndromal craniofacial synostosis, where major fronto-orbital, midface or maxillary reconstructions are often called for.

Craniofacial Dysostosis↗
PubMed2000

[Frontoethmoidal meningoencephaloceles].

Frontoethmoidal meningoencephalocele is a rare congenital disease where intracranial masses protrudes through a midline defect at foramen coecum from the anterior cranial fossa into the facial skeleton. The patient presents at birth with a soft-tissue swelling at the nasal bridge. In the majority of cases, the cele is completely covered by skin. The face is elongated, the nasal bridge is broad, the upper part of the nose is long, and the patients have telecanthus. Frequently, the patients have a normal psychomotor development, but may have intracerebral malformations and a shunt dependent hydrocephalus. Spinal fluid leakage may result in meningitis. Anosmia is infrequent. The patients may have a wide range of ophthalmological problems. Newborns with meningoencephalocele should be examined by a neurosurgeon. The investigation and work-up commences with a multidisciplinary approach. We present two patients with meningoencephaloceles.

Child↗
PubMed2000

[Long-term survival following surgery and radiotherapy of brain tumors in childhood].

BACKGROUND: Brain tumours are seen in about one third of children with neoplastic disease. Treatment usually includes surgery and/or radiotherapy. Radiotherapy may have serious late effects, especially in children under the age of three; but is necessary for survival in children with medulloblastomas or high-grade gliomas. MATERIALS AND METHODS: We report ten and 20 years survival rates in 115 children with primary brain tumours (58 medulloblastoma, 14 high-grade gliomas, and 43 low-grade gliomas) operated at the National Hospital and given radiotherapy at the Norwegian Radium Hospital during the years 1970-1995. RESULTS: No patients with medulloblastomas or high-grade gliomas relapsed after ten years. Overall ten and 20 years survival in children treated with radiotherapy to tumour doses > 50 Gy for medulloblastoma was 51.5% and for high-grade gliomas 20%. Median survival for patients with low-grade gliomas was not reached at 20 years, but these patients were still at risk for late deaths. INTERPRETATION: Long-term survival in children with high-grade gliomas or medulloblastoma equals cure, while late relapses may occur in low-grade gliomas.

Adolescent↗
PubMed2000

Monobloc and midface distraction osteogenesis in pediatric patients with severe syndromal craniosynostosis.

We present 2 children with severe syndromal craniosynostosis who were in need of urgent midface advancement surgery due to recurrent ocular dislocations (Pfeiffer's syndrome type II) or severe upper respiratory obstruction (Crouzon's syndrome). They were operated using distraction osteogenesis, with gradual midface or monobloc advancements. In the Pfeiffer patient, a maxillary distraction of 25 mm achieved effective cessation of ocular dislocations, whereas a 23-mm monobloc advancement in the Crouzon patient achieved cessation of nocturnal arterial desaturations. No major postoperative complications were recorded. Distraction osteogenesis has become a versatile and safe technique that allows for large skeletal advancements.

Acrocephalosyndactylia↗
PubMed1999

Posterior fossa medulloblastoma in children and young adults (0-19 years): survival and performance.

The objective of this study was to present survival data and outcome status in the long-term survivors of a consecutive series of 111 children and young adults treated for posterior fossa medulloblastoma in our departments from 1960 to 1997. The total surgical mortality was 13%. The surgical mortality rate declined significantly during the time period overall, from 23% before 1970 to 0% after 1990. The 5-year survival rate for patients treated between 1960 and 1973 was 0%, while 5-year survival for patients treated after the introduction of systematic craniospinal radiation in 1974 was 53%. Thirty-four patients were alive at the close of this study, with a mean observation time of 13.5 years. Over half, 61%, of the patients had one or more major deficits/problems with respect to learning ability, power of locomotion, sociability, hobbies and relationships with the opposite sex. A younger age at the time of treatment was correlated with larger deficits/problems in these variables. The correlation between young age at the time of treatment and short final height was significant. The frequency of a second neoplasm was 14%. In all but 3 cases the major cause of permanent deficits/problems was radiation therapy.

Adolescent↗
PubMed1996

Concomitant expression of hepatocyte growth factor/scatter factor and the receptor c-MET in human myeloma cell lines.

Myeloma cell line supernatants were screened for their ability to inhibit the activity of transforming growth factor-beta (TGFbeta) in the mink lung cell (Mv-1-Lu) bioassay. Supernatant from the human myeloma cell line JJN-3 contained potent TGFbeta antagonistic activity. This activity was isolated and found to be associated with a 72-78-kDa glycoprotein. Specific polyclonal and monoclonal antibodies were generated toward the 72-78-kDa protein, and these antibodies precipitated the TGFbeta inhibitory activity from JJN-3 supernatant. Upon amino acid sequencing the protein appeared to be identical to hepatocyte growth factor (HGF), and some of the generated antibodies directly blocked the action of recombinant HGF in various assays. By HGF-specific polymerase chain reaction we demonstrated that HGF mRNA was expressed in five out of five tested myeloma cell lines. The level of HGF protein in supernatants showed great variation from >500 ng/ml in JJN-3 supernatant to a few ng/ml in the supernatants from other myeloma cell lines. The same five cell lines were also screened for expression the HGF receptor c-MET. Four of them expressed the receptor as shown by reverse transcriptase-polymerase chain reaction and Western blot. The receptor was shown to be constitutively phosphorylated in the human myeloma cell line JJN-3. This receptor could be dephosphorylated by anti-HGF antibodies, indicating the existence of an autocrine HGF loop in this cell line. We propose that HGF/c-MET may play a role in multiple myeloma.

Animals↗
PubMed1996

Effects of endothelin-1 on hepatic blood flow.

Endothelin-1 belongs to a family of potent vasoconstrictors, recently isolated from endothelial cells. Endothelin-1 has a variety of hepatic effects and hepatic clearance from the circulation is important. Elevated plasma concentrations of Endothelin-1 are found after orthotopic liver transplantation and in cirrhosis with ascites. This study in piglets on hepatic bloodflow was designed to compare differences in effects between central venous and intraportal injection of endothelin-1, and to evaluate effects of repeated injections. Central venous injection of endothelin-1 caused a larger reduction in portal vein flow, while intraportal injection caused a larger increase in portal vein pressure. Repeated injections resulted in a reduction in portal vein flow and an increase in portal vein vascular resistance.

Animals↗
PubMed1994

[Percutaneous lumbar diskectomy].

At the Department of Neurosurgery in Trondheim, 17 patients with low backpain and sciatica have been operated upon using percutaneous lumbal discectomy. The procedure was carried out under local anaesthesia and all patients were discharged on the first day after operation. Seven patients recovered completely, four patients showed some improvement, and six patients showed no change. All the patients who reported a complete recovery experienced pre-operative stress-dependent radicular pain with mild neurological deficits. In contrast, the group of patients who showed no change suffered more constant pain, with a diffuse localization and no neurological deficits. It is important to make a thorough pre-operative evaluation of these patients, and correct selection is essential to achieve a good result.

Adult↗
PubMed1994

TNF and IL-6 are potent growth factors for OH-2, a novel human myeloma cell line.

A novel human myeloma cell line, OH-2, was established from pleural fluid of a myeloma patient in end stage of the disease. Effects of cytokines on proliferation were analyzed by measuring uptake of 3H-thymidine. Cell surface antigens were detected by flow cytometry. The cell line is dependent on IL-6 for growth and proliferates in response to TNF. There is synergy between the stimulatory response of TNF and IL-6. The cells express both the p55 and p75 TNF receptors. Neutralizing anti-IL-6 did not inhibit TNF-mediated proliferation, showing that TNF acts through a pathway that is independent of IL-6. TNF was more potent than IL-6 in stimulating the growth of primary myeloma cultures (> 99% pure) from the same patient (OH-2-PC), indicating that TNF in selected myeloma patients has a growth-promoting effect equal to IL-6. OH-2 cells produce and secrete monoclonal IgG-kappa.

Antigens, CD↗