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Biomedical subjects

N Klug

Publications and source records attributed to N Klug.

At least 73 records · Page 4Linked to original sources
PubMed1994

111Indium (DTPA-octreotide) scintigraphy in patients with cerebral gliomas.

Somatostatin receptors (SR) have been identified in vitro in normal brain tissue, in neuro-endocrine tumours and in cerebral gliomas WHO grade 1 or 2 by autoradiography or using somatostatin-gold conjugates. In vivo, SR detection has become possible by scintigraphy applying the somatostatin analogue octreotide, radio-labelled with 111Indium. It was supposed that expression of SR in cerebral gliomas corresponds to low grade tumour malignancy and that, in vivo, somatostatin receptor scintigraphy (SRS) could refine and improve the WHO grading system for cerebral gliomas. Nineteen patients with cerebral gliomas (grade 2: n = 8, grade 3: n = 3, grade 4: n = 8) were examined with 111In (DTPA-octreotide) to evaluate, whether SRS could improve the pre-operative estimation of tumour biology and the postoperative management. The results of SRS were related with the histological findings and with the in vitro demonstration of somatostatin-binding sites on cultured tumour cells incubated with a somatostatin-gold conjugate. In vivo, none of the patients with glioma grade 2 showed enhanced tracer uptake in the SRS, whereas in vitro SR were detected in cultured tumour tissue in 5 out of 5 cases. Every patient with glioma grade 3 or 4 demonstrated a high focal uptake of 111In (DTPA-octreotide), as shown by SRS. Three patients with glioma grade 4, additionally examined with 99mTc-DTPA, showed an increased tracer uptake within the tumour area when compared with results of SRS.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1994

[Changes in visually evoked potentials in space-occupying processes of the posterior fossa--on the problem of ascending transtentorial herniation].

Through the use of VEP investigations in 82 patients with space occupying lesions in the infratentorial region this study attempts to find the cause and location of dysfunctions of optical signal pathways. The majority of such expandatory processes involved tumours exterior to the brainstem of inhomogeneous histomorphology (n = 65). The rest involved metastases of the cerebellum (n = 5) and expanding infarcts of one cerebellar hemisphere (n = 12). Besides a shifting of the 4th ventricle (n = 64) an accompanying hydrocephalus (n = 40) and an ascending transtentorial herniation (n = 29) was indicated radiologically. A pathological VEP was found in just over half of the patients (n = 43). Usually, the VEP change involved a latency increase of the cortical potential (P2). In 6 of these patients a complete loss of this potential was noted. Furthermore, ten more of these patients did not have the P1-following negative potential (N2). In 32 patients with a pathological VEP a hydrocephalus was proven to be present. On the other hand, there were 8 patients with accompanying hydrocephalus but with a normal VEP. All 29 patients, though, with a radiological ascending herniation had changed VEP. Three of these patients had no accompanying hydrocephalus. Following surgical decompression a complete normalization of the VEP set within 2 to 3 weeks, while it reappeared in tumour recurrence. These findings indicate that dysfunctions of VEP, that is the visual pathways in infratentorial occupying lesions are not only dependent on the existence of accompanying hydrocephalus.(ABSTRACT TRUNCATED AT 250 WORDS)

Cerebellar Neoplasms↗
PubMed1994

Intracerebral hemorrhage during treatment with oral anticoagulants. Risk factors, therapy and prognosis.

Intracerebral hemorrhage (ICH) during oral anticoagulation is a serious complication, which is mostly fatal for the multimorbid patient. In the present retrospective study of 53 patients with ICH during treatment with a cumarin derivative (Phenoprocoumon, Marcumar), we investigated the relationship between therapy and preexisting parameters such as age, location, level of consciousness, additional bleeding risks, and the degree of anticoagulation, which were assumed to be of prognostic relevance. The therapeutic management of ICH during treatment with anticoagulants was determined predominantly by location of the hematoma, patient's age, and additional bleeding risks, but less by level of consciousness and initial thromboplastin time (Quick's test). As a consequence of the individual analysis of these 5 parameters, age over 60 years, location of hematoma in the midline or ventricles, coma, additional bleeding risks such as arterial hypertension and trauma, and Quick's test below 15% at the time of bleeding were supposed to be responsible for poor prognosis. Mortality increased with a rising number of poor prognostic factors, independently of surgical or conservative treatment. In consequence, prognosis of ICH during oral anticoagulation is predominantly influenced by the number of such disadvantageous indicators and only little by therapy.

Administration, Oral↗
PubMed1993

Somatostatin receptor scintigraphy in brain tumors and pituitary tumors: first experiences.

Somatostatin receptors have been demonstrated on various tumors of neuroendocrine and other origin. They have been detected in vitro by biochemical techniques as well as by autoradiography. The development of long-acting somatostatin analogs and the recent availability of radiolabeled octreotide have made the in vivo detection of somatostatin receptors possible. This preliminary study embraced 45 patients with meningiomas, brain tumors or pituitary tumors, which were imaged by planar and tomographic scintigraphy after intravenous injection of 111Indium-labeled octreotide. In all of the meningiomas studied (unifocal and multifocal tumors in various locations), a high density of somatostatin receptors was detected by scintigraphy. Pituitary tumors were slightly positive in 50% of cases only, independent of the endocrine activity. Gliomas with an intact blood-brain barrier showed no enhanced tracer uptake in vivo, while gliomas with disturbed blood-brain barrier had a high activity uptake. We conclude that in vivo somatostatin receptor scintigraphy, although not tumor-specific, may aid in the preoperative diagnosis and staging of intracranial tumors, especially skull base tumors.

Adult↗
PubMed1992

Spontaneous intracerebral hemorrhage from an unsuspected ependymoma in early infancy.

A case of spontaneous intracerebral hemorrhage from an occipital ependymoma grade 2 in a 3-month-old boy is reported. The infant died 3 days after surgery. The clinical and pathomorphological characteristics are described. Despite the usually rich vascularization of these tumors, hemorrhages from intracranial ependymomas are relatively uncommon. The different forms and probable causes of bleedings are discussed.

Brain Neoplasms↗
PubMed1992

Lesions of the sensorimotor region: somatosensory evoked potentials and ultrasound guided surgery.

In 10 patients with lesions of the sensorimotor cortex cortical SEP were registered to identify the postcentral gyrus, and intra-operative ultrasound sonography served to locate the lesion. The combination of both techniques helped to find the optimal approach to the lesion. Postoperative results were considered favourable, as only one patient suffered transient postoperative deterioration, six were unchanged and in three patients the pre-operative motor deficits were improved. The combination of intra-operative ultrasound and neurophysiological identification of the sensorimotor cortex is concluded as being useful in surgery within this region.

Adult↗
PubMed1992

Transglutaminase activity in human brain tumors.

Transglutaminase (TG) activity was measured in tissue samples of 45 human brain tumors (pituitary adenomas, meningiomas and gliomas) obtained during neurosurgery. Biochemical analysis and histopathological classification were carried out in the same samples. Mean enzyme activity was highest in non-glial tumors, but due to a high variability of values no significant changes were found between the various histological groups. Thus, TG activity, although considered to play a role in neoplastic growth, does not represent a biochemical marker of malignancy in human brain tumors.

Adenoma↗
PubMed1992

Activity of ornithine decarboxylase (ODC) and polyamine levels as biochemical markers of malignancy in human brain tumors.

The content of the polyamines putrescine, spermidine and spermine, and the activity of their metabolic key enzyme ornithine decarboxylase (ODC) were measured in tissue samples obtained during operation of 45 patients with primary or recurrent gliomas, meningiomas and pituitary adenomas. Biochemical analysis and histopathological classification were carried out in the same tumor samples. In benign tumors ODC activity was less than 10 nmol/g/h, whereas in malignant gliomas values up to 34 nmol/g/h were observed. In rapidly growing tumors pronounced heterogeneity was observed with high values in solid tumor parts and low values in necrotic areas. Thus, high ODC activity represents a reliable biochemical marker of malignancy in brain tumors, but low values do not prove benignity.

Adenoma↗
PubMed1991

Transcranial Doppler sonography and intracranial pressure monitoring in children and juveniles with acute brain injuries or hydrocephalus.

Transcranial Doppler sonography is a noninvasive method of obtaining information about changes in cerebral hemodynamics and intracranial pressure. After severe head injuries the development of brain swelling and brain edema can be assessed and the efficacy of treatment monitored. Development of severe brain edema accompanied by a rapid increase in intracranial pressure can be recognized by a decrease in blood flow velocity and rise in the pulsatility index. In hydrocephalic children the behavior of the cerebral blood flow velocity and the pulsatility index will warn of an increase of the ventricular fluid pressure or a shunt insufficiency.

Adolescent↗
PubMed1990

Different types of postoperative diabetes insipidus and the relation to basal and stimulated serum prolactin levels in patients with hypothalamo-hypophyseal tumorous lesions.

To evaluate the interrelationships between anterior pituitary function and the antidiuretic system in patients harbouring hypothalamo-hypophyseal tumorous lesions, combined anterior pituitary stimulation tests were performed in the pre (n = 192 patients) and postoperative (n = 151 patients) state. Basal and stimulated plasma antidiuretic hormone, serum as well as urinary osmolality and diuresis were analyzed to determine the residual functional capacity of the antidiuretic system. In 106 patients with non-prolactin (PRL) secreting tumours basal and stimulated PRL secretion of the residual anterior pituitary was studied pre- and postoperatively. It was found that in the preoperative state latent (n = 12 patients) or manifest (n = 10 patients) types of diabetes insipidus (DI) were related to a significant decrease of maximal stimulated levels of thyroid stimulating hormone as well as basal and maximal stimulated levels of follicle stimulating hormone relative to patients without DI. In the postoperative state DI lasting longer than 10 days (n = 51 patients) was associated with decreased basal and maximal stimulated concentrations of cortisol, luteinizing and follicle stimulating hormone, whereas basal and maximal stimulated levels of PRL were significantly increased compared to those patients without DI (n = 61 patients). Decompression (n = 65 procedures) via the transnasal route was related with a lower frequency of the more severe types of DI (n = 7 patients) and a significant decrease of basal and maximal PRL levels in patients with non-PRL secreting tumours. The transcranial approach (n = 86 procedures) caused a higher rate of severe DI types (n = 33 patients) and an increase of PRL secretion from the residual anterior pituitary lobe. Patients without DI or DI of mild severity (n = 50), as a group, had a significant decrease of basal and maximal PRL levels compared with preoperative values (preoperative: basal = 14.3 +/- 1.5 ng/ml, max = 31.4 +/- 1.5 ng/ml, postoperative: basal = 9.6 +/- 1.1 ng/ml, max = 24.9 +/- 2.9 ng/ml). In patients with severer degrees of DI (n = 40) PRL levels were significantly increased, respectively (preoperative: basal = 15.3 +/- 3.1 ng/ml, max = 23.9 +/- 7.6 ng/ml, postoperative: basal = 19.7 +/- 3.4 ng/ml, max = 38.6 +/- 7.9 ng/ml). It was concluded that in the surgical treatment of non-PRL secreting hypothalamo-hypophyseal lesions the results of early postoperative assessment of basal and stimulated PRL levels may predict the type of postoperative DI.(ABSTRACT TRUNCATED AT 400 WORDS)

Adolescent↗
PubMed1990

Growth rate of incidental meningiomas.

A meningioma was incidentally identified with computerized tomography (CT) in 17 patients without relevant clinical signs. The tumor was not removed, but biopsy confirming a meningioma was obtained from one patient. Tumor growth rate was calculated from repeat CT scans or follow-up magnetic resonance imaging. The annual growth rate ranged from less than 1% to 21%. It is concluded that in nonsymptomatic meningiomas with a low growth rate a nonsurgical approach may be warranted.

Aged↗
PubMed1989

Rhinorrhea following dopamine agonist therapy of invasive macroprolactinoma.

We report on the occurrence of CSF rhinorrhea in a group of 17 patients harbouring macroprolactinomas who were treated with a dopamine agonist (DA, bromocriptine) alone or the combination of DA and transcranial operation. In 2 out of 17 cases shrinkage of tumour remnants during therapy with the oral or injectable form of bromocriptine was responsible for delayed occurrence of rhinorrhea. Operative procedures for successful closure of the fistulae were mandatory in both cases.

Adult↗
PubMed1988

[Giant cell tumors, aneurysmal bone cysts and osteoid osteomas of the spine].

Experience collected by us from treating 15 patients suffering from giant cell tumours, aneurysmatic bone cysts or an osteoid osteoma prompted us to investigate which progress has been made to date in the diagnosis and treatment of these lesions that contain giant cells, basing on recent diagnostic methods such as computed tomography and magnetic resonance, as well as neurosurgical methods. It was found that the course of these rare changes cannot be influenced either by extensive diagnostic or special neurosurgical measures and that the prognosis finally depends on the growth trends inherent in the lesion concerned. Now that both diagnostic and surgical techniques are more refined than previously, there is a tendency to an improved individual approach that is better suited to the needs of the patient. Radiotherapy of benign changes involving giant cells in the region of the vertebral column is no longer of any importance.

Adolescent↗
PubMed1988

[Intraoperative monitoring with visual and auditory evoked potentials].

Intraoperative monitoring techniques concerning evoked potentials have been used during operations on the spinal cord as well as in carotid endarterectomy and in aneurysm surgery. The monitoring of early acoustic evoked potentials during surgery of the posterior fossa and the registration of the visually evoked potentials in patients suffering from pituitary adenoma or other space occupying lesions of the sella region seem to provide information about function of nerves and brain stem structures. This paper deals with positive and negative aspects of intraoperative monitoring of visual and acoustic evoked potentials.

Brain Neoplasms↗
PubMed1987

Electrically elicited blink reflex and early acoustic evoked potentials in circumscribed and diffuse brain stem lesions.

In the present paper, the function of the brain stem in patients with brain stem lesions of various aetiology is investigated with electrophysiological methods. The clinical observations are supplemented by experimental investigations on cats, in which the blink reflex and the early acoustic evoked potentials were registered during the acute elevation of intracranial pressure. The findings in patients with circumscribed space-occupying lesions in the posterior fossa document that the registration of the BR and the BAEP have a functional diagnostic significance above and beyond the neurological and radiological investigation. In the case of the cerebellar space occupations, specific alterations could not be observed. On the contrary, the alterations of BR and BAEP indicate a general disturbance of brain stem function, possibly as a result of a general increase of intracranial pressure. In cerebellopontine angle tumours, both BR and BAEP showed specific alterations which were usually asymmetrical. The BR changes ipsilateral to the tumour are of major topodiagnostic significance, whereas the alterations of the contralateral potential are especially informative in the registration of BAEP. The alterations of BR and BAEP also allow an appraisal of the localization and extent of the lesion in primary space occupations in the brain stem: A pathological R1 indicates a pontine lesion, whereas pathological R2 responses are found in medullary and in oral pontine and mesencephalic lesions. In contrast to cerebellopontine angle tumours, the BAEP tends to show symmetrical alterations in primary brain stem lesions. The prolongations of interpeak latencies correspond to the brain stem segment concerned, and the same also applies to pathological amplitude reduction and deformations of individual potentials. In patients with localized brain stem damage, the reflex pathway of R2 is discussed on the basis of the BR findings. In contrast to the view held up to now that only structures situated caudal of the facial nucleus area are responsible for the genesis of the R2 response, it is assumed on the basis of our own observations that pontomesencephalic structures rostral to the facial nuclei are also important for the genesis of R2. Registration of BR and BAEP in patients with acute diffuse brain stem damage shows that both methods have a high diagnostic and prognostic value. Isolated damage and combined brain stem lesion can be demonstrated and the course can be followed up. Normalization of pathological findings reflects clinical recovery, and conversely a secondary deterioration indicates the presence of complications.(ABSTRACT TRUNCATED AT 400 WORDS)

Adult↗