Biomedical subjects

K Wester

Publications and source records attributed to K Wester.

At least 73 records · Page 4Linked to original sources

PubMed1994

[Subarachnoid hemorrhage. Severe consequences of delayed diagnosis].

A total of 123 patients with subarachnoid haemorrhage were admitted to the Department of Neurosurgery, Haukeland Hospital, during the years 1990-93. In 16 patients, there was a delay from the first haemorrhage until diagnosis and treatment. In eight patients, the delay was caused by incorrect medical diagnosis, while two patients did not seek medical attention immediately after onset of symptoms. In the remaining six patients, the delay was caused by both patient and physician. In all but one patient, the first symptom was an unusually severe acute headache which in some cases was accompanied by nausea and vomiting, in others not. Altogether nine patients suffered renewed bleeding, and three patients died. Three patients showed neurological impairment postoperatively. The article deals with the importance of early diagnosis in patients with subarachnoid bleeding, and suggests how these patients should be handled by their primary doctors and at the hospitals to which they are referred.

Adult↗

PubMed1994

Auditory neglect and the ear extinction effect in dichotic listening: a reply to Beaton and McCarthy (1993).

In our reply to Beaton and McCarthy (1993), we argue that the issue of ear extinction in dichotic listening also should take into account lesion site and lesion extension. When the lesion is primarily affecting the auditory pathways, the resulting dichotic dysfunction may be an ear extinction effect. However, when the lesion is outside of the auditory system, the absence of reports from one ear may be part of a larger cognitive deficit, involving more complex processes, like orientation and attention. Thus, by constraining the definition of an "ear extinction effect" to a perceptual deficit, Beaton and McCarthy confounds the issue of ear extinction with auditory neglect. In our reply we also present some new data from a patient with a left-sided thalamic pulvinar lesion, contrasting his dichotic listening performance with the patient reported in our original 1991 study.

Adult↗

PubMed1994

Cranioplasty with an autoclaved bone flap, with special reference to tumour infiltration of the flap.

The results of a total of 25 cranioplasties are reported. In 10 patients, a reinforced acrylic prosthesis was utilized. In the remaining 15 cases, the patient's own autoclaved bone flap was re-implanted. Six of these bone flaps were autoclaved to kill tumour cells, and was re-implanted during the same surgical procedure. In the remaining 9 patients, the flaps were removed to allow brain swelling, preserved in a freezer and re-implanted several months later. All the prostheses and re-implanted flaps were accepted by the patients without complications such as infections or resorption, and with cosmetically satisfying results. The tumour infiltrated flaps remained tumour free for the entire period of observation.

Acrylates↗

PubMed1994

Organ culture of a glioblastoma from a patient with an unusually long survival.

Multicellular tumor spheroids were directly initiated in vitro from the biopsy specimens of a patient who is alive and who has had no neurological changes in 7 years after the gross removal of a glioblastoma. The spheroids were studied alone and in confrontation with aggregates of fetal rat brain tissue. Both in the biopsy and in the tumor spheroids, a very high proportion of cells were proliferating, as flow cytometric deoxyribonucleic acid measurements showed that 40% of the cells in the biopsy specimens and in the tumor spheroids were in the S and G2M phases of the cell cycle. Despite this high proliferation rate, the volume of the spheroids decreased, indicating an even greater cell loss. Light and scanning electron microscopic studies also indicated cell death in the spheroids. This behavior may be related to the long-time survival.

Animals↗

PubMed1994

Shunt failures and complications in adults as related to shunt type, diagnosis, and the experience of the surgeon.

Data from 95 adult patients (43 males, 52 females) treated with ventriculoperitoneal shunts during an 8-year period were analyzed to investigate risk factors in shunt surgery. All patients were seen in the authors' department and were grouped according to the cause or type of hydrocephalus. The operating surgeons were divided into two categories: specialists and residents. The shunts were classified as single- (Orbis-Sigma) or multicomponent (Holter or Hakim) systems. Two types of unfavorable events were recognized: complications and shunt malfunction. A total of 143 surgical procedures (implantations and revisions) were performed in the 95 patients; 24 patients had their shunts revised, and there were 13 complications (one fatal, five severe) resulting from the shunt surgery. The following observations were statistically significant: 1) patients with normal pressure hydrocephalus had no complications from shunt surgery; 2) the number of shunt malfunctions was lower in patients with intracranial hemorrhages than in the other groups; 3) residents performed a higher number of inadequate operations than did specialists; and 4) the infection rate was higher among patients operated on by residents. The choice of shunt type, the perioperative use of antibiotics, and the degree of surgical emergency were not correlated with complication or failure rates.

Adolescent↗

PubMed1994

[Handling of organ donors].

Patients suffering from complete destruction of the brain and brain stem are the most common source of organs for transplantation purposes. However, as the lack of such organs is currently the most limiting factor regarding the scope of transplantation treatment, it is of the utmost importance that all potential donor organs are well maintained.

Brain Death↗

PubMed1994

Grading of transitional cell bladder carcinoma by texture analysis of histological sections.

Conventional subjective visual grading of malignancy in bladder carcinoma suffers from poor standardization. In an attempt to improve this by image analysis we carried out a texture analysis of a total of 197 images from Feulgen-stained histological tissue sections. The textural features used were based on the spatial gray-tone co-occurrence probability matrices for step-lengths 3, 4 and 6 pixels. These features were compared to the subjective grading by multivariate statistical methods. Using a two-stage hierarchical classifier 84.3% agreement was obtained between the subjective and computer-based classification. This was verified through the jackknifed classification technique.

Carcinoma, Transitional Cell↗

PubMed1992

[Organ donation from recently deceased patients. Experiences from a donor hospital and suggestions for handling potential organ donors and their relatives].

Homologous organ transplantation using organs from patients suffering complete destruction of the brain and brain stem is a major achievement in modern medicine. The care of potential organ donors and their relatives is complex and very demanding for the medical team and nursing staff. In Norway the law sets very clear criteria (documentation of total irreversible brain and brain stem injury) for performing donation. As a rule consent from the family is asked for, although not legally required. This article deals with the problems related to the treatment of potential organ donors. We give practical guidelines for medical staff on how to prepare the patient and his/her family, with emphasis on the human and psychosocial aspects. Preservation of the donor and the organs is not discussed.

Decision Making↗

PubMed1992

Combined intra-arterial chemotherapy followed by radiation in astrocytomas.

Seventy-five patients harboring astrocytomas received 4 cycles of infra-ophthalmic carotid injections of BCNU, combined with vincristine intravenously and procarbazine orally. All of the patients thereafter, received radiation therapy. The five year survival was 73% for all patients. The age of the patients had no significant impact on survival. The treatment results were compared with the results of 57 patients with astrocytomas who were treated with surgery followed by radiation in the same period. These 57 patients had a 5 year survival of 45% with a five year survival in patients < or = 40 years and patients > 40 years of 70% and 22%, respectively (p < 0.05). In multivariate survival analysis of the BCNU group and radiation group together, treatment group and corticosteroid dependency were the only prognostic factors. No leukoencephalopathy was seen during the treatment or in the follow-up of the patients. We conclude that pre-radiation intra-arterial chemotherapy can be given without significant morbidity and produces an improvement in survival in patients older than 40 years.

Administration, Oral↗

PubMed1992

The prognostic value of intra-operative observations during thalamotomy for parkinsonian tremor.

Data from 27 thalamotomies were analyzed with respect to possible correlations between certain intra-operative observations and the long-term effect on parkinsonian tremor. Tremor reduction caused by mechanical impact of the electrodes in the target area was not correlated with the long-term effect on the tremor. The same was true for the threshold intensities during the intra-operative electrical stimulation of the target area, stimulation that facilitates and/or inhibits the tremor. In a minority of the patients, all with good long-term results, a combination of a pronounced tremor inhibition from the electrode insertion and a low threshold intensity was observed. Variations in other lesion parameters were not correlated with the outcome. The results are discussed within the framework of a "tremor" vs. a "tonus" mechanism underlying the thalamotomy effect.

Aged↗

PubMed1992

Dysfunction of Holter Mini Elliptical valves caused by minor head trauma.

Two patients with implanted shunts suffered three disconnections of the shunt catheters from the valve chamber as a result of minor head trauma. In all instances a Holter Mini Elliptical valve had been used. The design of this valve may facilitate the kind of shunt dysfunction described. Suggestions are made for small changes in the shunt design or surgical procedures to obviate the vulnerability of the shunt to minor trauma.

Astrocytoma↗

PubMed1992

Expression of proliferative cell nuclear antigen (PCNA) in urinary bladder carcinoma. Evaluation of antigen retrieval methods.

Proliferative cell nuclear antigen (PCNA) expression was analyzed in formalin-fixed and paraffin-embedded specimens from patients with urinary bladder cancer using three different anti-PCNA monoclonal antibodies. In 20 recent cases a positive correlation was found between the extent and intensity of PCNA staining and grade of malignancy. In 95 specimens, three to six years old, extensive positive staining was detected in 15 and 23% of grade 2B and 3-4 tumors, respectively. No equivalent staining was found in the grade 1 and 2A tumors. In material more than six years old, a remarkably weak staining was observed regardless of grade. Similarly, in a test of archival material of tonsils a very weak immuno-reactivity was found as compared with fresh material. However, antigen retrieval by microwave heating of the tissue sections was possible in the majority of all cases, and the difference in extent and intensity of the staining between low and high grade tumors remained.

Antibodies, Monoclonal↗

PubMed1992

Benign intracerebral cysts treated with internal shunts: review and report of two patients.

Two elderly women with symptomatic benign intracerebral cysts are reported. Before treatment, they both had developed moderate, but slowly increasing, symptoms from a cyst in the left hemisphere, which included epileptic seizures and right hemiparesis. During local anesthesia, an internal cystosubarachnoid shunt was inserted. After the operation, the cyst size was reduced markedly, with a corresponding improvement in the symptoms. A review of reported cases of benign intracerebral cysts is given. The average age of these patients is surprisingly high for a presumed congenital condition. There is a female preponderance, but the previously reported overrepresentation of left-sided lesions is not found in cases described after the introduction of computerized tomographic imaging.

Age Factors↗

PubMed1992

Gender distribution and sidedness of middle fossa arachnoid cysts: a review of cases diagnosed with computed imaging.

According to earlier reports, arachnoid cysts seem to occur more frequently in males, and on the left side. The latter phenomenon could, however, be explained by a greater significance attributed to symptoms from the dominant hemisphere as a justification for invasive procedures in the pre-computed tomography era. The literature from the last third of the era of computed tomography is reviewed with respect to gender distribution and sidedness for middle fossa arachnoid cysts. Also included are a few cases of our own from the same period. It is evident from this survey of the literature, based on computed tomography studies, that there is a significant tendency for these cysts to occur in males, with a male/female ratio of nearly 3:1. This preponderance toward males could not be explained by the somewhat higher frequency of associated subdural hematomas that was found in male patients. The survey also showed that middle fossa arachnoid cysts occur or are detected significantly more frequently on the left side than on the right, with a ratio of 1.8:1.

Arachnoid Cysts↗

PubMed1992

Dichotic listening studies of hemispheric asymmetry in brain damaged patients.

In the present paper we review the empirical evidence for structural versus attentional explanations of the right ear advantage (REA) phenomenon in dichotic listening (DL). The ear advantage in DL is a behavioral "marker" of language function in the cerebral hemispheres. Dichotic listening data from four brain-lesioned patients are presented. The patients had a tumor or cyst in the left Sylvian region (2 cases); hemorrhage in the left frontotemporal region (1 case); and severe destruction of the left hemisphere (1 case). The results from all four patients showed marked reductions in correct recall of the right ear items, while left ear recall was left unaffected. In two of the cases, the DL data showed an immediate reinstatement of the REA after neurosurgery. It is concluded that the results favor a structural/anatomical explanation of the ear advantage phenomenon in DL, rather than an attentional bias explanation.

Adult↗

PubMed1991

Determination of DNA ploidy and ABH antigen reactivity in both frozen and formalin-fixed bladder tumor tissue.

In a prospective series of patients with transitional-cell bladder carcinomas, DNA ploidy and ABH antigen reactivity were determined in both frozen tissue and formalin-fixed paraffin blocks. ABH antigen measurement in frozen tissue was hampered by methodological problems, especially insufficient morphology, which made quantification difficult. In only 38/55 (69%) cases was the same ABH reactivity found. The knowledge of secretor status was not helpful in the interpretation of these results. In 53/59 (90%) cases the same DNA ploidy was achieved, resulting in good correlation between flow cytometric DNA measurements in formalin-fixed and frozen tissue. The deviations occurred mainly in cases exhibiting a tetraploid DNA profile. DNA assessments using image cytometry on imprints of fresh tissue was a rapid and reliable method in our hands, with identical results being obtained in 32/36 (89%) cases.

ABO Blood-Group System↗

PubMed1991

Auditory neglect after right frontal lobe and right pulvinar thalamic lesions.

Auditory unilateral neglect or extinction to simultaneous stimulation is reported in a right-handed male with a lesion in the right frontal lobe and in the right thalamic pulvinar area. The patient was submitted to stereotactic thalamotomy for a post-traumatic intentional ataxia in the left extremities. He was subjected to repeated tests with dichotic listening to consonant-vowel syllables under three different attentional instructions. He was also tested monaurally with the same stimulus materials as used in the dichotic test. The results showed almost complete extinction of the left ear input during dichotic presentations, despite normal hearing when tested with audiometer screening. The left ear extinction effect was independent of instructions to attend to the left or right ear input. However, during monaural presentation, correct left ear reports increased to about 85%. The results are interpreted as showing an auditory attentional neglect caused by the right frontal and pulvinar lesions.

Adult↗

PubMed1991

Distribution of tamoxifen and metabolites into brain tissue and brain metastases in breast cancer patients.

We determined the amount of tamoxifen, N-desmethyltamoxifen (metabolite X), N-desdimethyltamoxifen (metabolite Z), and hydroxylated metabolites (Y, B, BX) in brain metastases from breast cancer and in the surrounding brain tissues. Specimens were collected from the breast cancer patients who received tamoxifen for 7-180 days and with the last dose taken within 28 h before surgical removal of the tumour. The concentrations of tamoxifen and its metabolites were up to 46-fold higher in the brain metastatic tumour and brain tissue than in serum. Metabolite X was the most abundant species followed by tamoxifen and metabolite Z. Small but significant amounts of the hydroxylated metabolites, trans-1(4-beta-hydroxyethoxyphenyl)-1,2-diphenylbut-1-ene (metabolite Y), 4-hydroxytamoxifen (metabolite B) and 4-hydroxy-N-desmethyltamoxifen (metabolite BX) were detected in most specimens. The ratios between the concentrations of tamoxifen and various metabolites were similar in tumour, brain and serum. This is the first report on the distribution of tamoxifen and metabolites into human brain and brain tumour, and the data form a basis for further investigation into the therapeutic effects of tamoxifen on brain metastases from breast cancer.

Adult↗