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Biomedical subjects

J Walecki

Publications and source records attributed to J Walecki.

At least 37 records · Page 2Linked to original sources
PubMed2000

Malignancy of brain tumors evaluated by proton magnetic resonance spectroscopy (1H-MRS) in vitro.

Biopsies of 6 malignant gliomas (grade 3 or 4) and 11 low-grade meningiomas were extracted with perchloric acid or methanol/water, and the fully-relaxed 1H-MRS spectra of the extracts containing water-soluble metabolites and a concentration and chemical shift standard were recorded at 11.4 T. The resonance signals assigned to inositol (Ino), glycerophospho- and phosphocholine (GPC + PC), choline (Cho), creatine and phosphocreatine (Cr + PCr), glutamate (Glu), acetate (Ac), alanine (Ala) and lactate (Lac) were integrated, and analyzed by two methods. First, the concentrations of the aforementioned substances in the bioptates were estimated from their resonance signals in the extracts. Second, these signals were normalized to the Cr + PCr resonance signal. The Mann-Whitney U-test was used to verify statistical significance between the data sets obtained for gliomas and meningiomas. When the first method of analysis was used, the only difference was in the Ala concentration, which in meningiomas was on average 4 times higher than in gliomas (P < 0.01). However, when the second method of analysis was applied, gliomas expressed lower normalized resonance signals of Ala and Glu (P < 0.001, ranges not overlapping), Lac (P < 0.005), as well as Ino and GPC + PC (P < 0.05). In proton MR spectra of brain tumor tissue extracts containing water soluble metabolites, the resonance signals normalized to that of total creatine may provide a very good discrimination between malignant gliomas and low-grade meningiomas.

Biopsy↗
PubMed2000

Cranial MRI in the Nijmegen breakage syndrome.

We present the results paragraph signof MRI examinations in ten patients with documented Nijmegen paragraph signbreakage syndrome (NBS), aged 1.75-19 years. T1-, Proton-Density- and T2-weighted spin-echo sequences were performed in three planes. All patients showed microcephaly with decreased size of the frontal lobes and narrow frontal horns. In four patients agenesis of the posterior part of the corpus callosum was found, with colpocephaly and temporal horns dilatation. In one patient callosal hypoplasia was accompanied by abnormal cerebrospinal fluid spaces and wide cerebral cortex, suspicious of pachygyria. Sinusitis was present in all ten patients, as a result of primary immunodeficiency. As in ataxia teleangiectasia and other breakage syndromes, patients with NBS show an inherited susceptibility to malignancy and hypersensitivity to X- and gamma-radiation. CT is therefore contraindicated in these patients and MRI should be the method of choice for diagnostic imaging.

Adolescent↗
PubMed2000

An assessment of lymphocytic population in peripheral blood of patients with renal cell carcinoma before and after embolization.

The immunophenotype of peripheral blood lymphocytes was evaluated in 50 renal cell carcinoma (RCC) patients, before and after embolization. In RCC patients we have observed significant decrease in the total lymphocyte number as well as in T lymphocyte, their subpopulations and B lymphocyte number. Ten to twelve months after the treatment by embolization, significant increase in the total number of not only lymphocytes (p < 0.001), including T lymphocytes (p < 0.001), T-helper lymphocytes (p < 0.05), cytotoxic T lymphocytes (p < 0.05) and B lymphocytes (p < 0.05), but also an increase of NK cells number (p < 0.05) were found, compared to the values obtained before the treatment and reached the level observed in healthy subjects. Cytometric evaluation of peripheral blood lymphocytic phenotype in renal cell carcinoma patients can help evaluate the immune status of RCC patients as well as assess the embolization efficiency.

Adult↗
PubMed1999

Role of short TE 1H-MR spectroscopy in monitoring of post-operation irradiated patients.

Post-surgical radiation therapy is a routine procedure in the treatment of primary malignant brain tumors. Along with modest therapeutic effects conventional fractionated radiotherapy, in spite of any modifications, produces damage to non-malignant brain tissues lying within the treatment volume, the extent of which depends on radiation dose. Serial 1H-MRS allows non-invasive investigation of tissue metabolic profiles. In the present study the ratios of resonance signals assigned to the major 1H-MRS-visible metabolites (N-acetylaspartate, choline, creatine, inositol, lactate and lipid methylene group) were evaluated before, during and after post-surgical fractionated radiotherapy in brain regions close to and more distant from the tumor bed, receiving different radiation exposures (60 and < 40 Gy, respectively). The study group consisted of ten patients (aged 28-51). A MRI/MRS system (Elscint 2T Prestige) operating at the field strength of 2 T and the proton resonance frequency of 81.3 MHz has been used and the 1H-MR spectra were acquired using single voxel double-spin-echo PRESS sequence with a short TE. The spectra were post-processed with automatic fitting in the frequency domain. It was found that although the metabolite profiles depend on the dose obtained, but other stress factors (like surgery) seem to contribute to the overall picture of the metabolic status of the brain as well. In studies of early irradiation injuries, an increase of choline related ratios may serve rather as cell proliferation indictors than as cell injury ones, whereas the mI/Cr ratio appears as one of the first indicators of local irradiation injury. In order to establish the prognostic marker for early radiation damage, however, it seems necessary to analyze all visible metabolites as well. None of the metabolites separately may serve as such an indicator due to the complexity of tissue metabolism. Interestingly, MRI reveals no changes during the therapy process, whereas the metabolite ratios are being affected in the course of time, thus supporting the presumption that the 1H-MRS is a valuable method of radiation therapy monitoring.

Adult↗
PubMed1999

Transcranial color Doppler sonography of basal cerebral arteries in 182 healthy subjects: age and sex variability and normal reference values for blood flow parameters.

OBJECTIVE: Only a limited number of transcranial color-coded Doppler studies have provided ranges for the normal reference values of cerebral hemodynamic parameters. These reports are not fully convergent in relation to the range of values or to the age and sex dependence of blood flow parameters. The aim of the present study was to provide data regarding normal reference ranges. SUBJECTS AND METHODS: We examined 182 healthy volunteers (79 men and 103 women; age range, 20-86 years old) with color-coded Doppler sonography via a temporal acoustic window with a 2.5-MHz transcranial probe. The subjects were divided into three age groups: 20-40 years old (group 1), 41-60 years old (group 2), and more than 60 years old (group 3). Angle-corrected peak systolic, end-diastolic, and mean velocities as well as impedance indexes were determined in anterior, middle, and posterior cerebral arteries. RESULTS: Mean velocity values for middle, anterior, and posterior cerebral arteries in age group 1 were 81+/-20, 56+/-14, and 52+/-12 cm/sec (mean +/- SD), respectively. In group 2, the values were 73+/-19, 53+/-16, and 51+/-12 cm/sec (mean +/- SD), and in group 3, the values were 59+/-11, 44+/-11, and 40+/-9 cm/sec (mean +/- SD). Decrease in blood flow velocities and a concomitant increase in impedance indexes were found in all vessels with advancing age-findings that were most pronounced in subjects who were more than 40 years old. In the 20- to 40-year-old group, mean velocities for all vessels were higher in women than in men, whereas impedance indexes were not significantly different. CONCLUSION: Flow velocities in basal cerebral arteries range widely and are significantly age dependent. Age and sex matching of Doppler sonographic data is a prerequisite for clinically valuable conclusions.

Adult↗
PubMed1998

Secondary adrenal insufficiency associated with autoimmune disorders: a report of twenty-five cases.

OBJECTIVE: Addison's disease is frequently a component of autoimmune polyendocrinopathies while secondary adrenal insufficiency associated with autoimmune disorders is believed to be a rare event. We present a series of patients with secondary adrenal insufficiency coexisting with autoimmune diseases and/or antithyroid autoantibodies. DESIGN AND PATIENTS: Among a group of 102 patients with secondary adrenal failure of unknown origin diagnosed at the Department of Endocrinology of the Centre for Postgraduate Medical Education (Warsaw, Poland) we have identified a group with associated autoimmune disorders. Thyroid abnormalities occurred most frequently. Other diseases included insulin-dependent diabetes mellitus, pernicious anaemia, vitiligo, premature ovarian failure and autoimmune thrombocytopaenia. There were 23 women and one man aged 17-72 years at the time of investigation. Additionally, we included a woman with Addison's disease in whom the ACTH deficiency appeared 18 years after the onset of primary adrenal hypofunction. MEASUREMENTS: Pituitary-adrenal function tests comprised urinary excretion of 17-hydroxycorticosteroids in basal conditions and during a 2-day tetracosactrin test, plasma concentrations of ACTH and cortisol, and a 2-day metyrapone test (in eight cases). Thyroid function and immunity tests were: TSH, thyroxine, the antithyroglobulin, antimicrosomal and anti-peroxidase autoantibodies. Other endocrine studies included: serum LH, FSH and PRL. RESULTS: The 17-hydroxycorticosteroid values, both basally and during stimulation tests were consistent with a diagnosis of secondary adrenal insufficiency. Serum cortisol and plasma ACTH concentrations were low. In 14 patients primary hypothyroidism was confirmed by low T4 levels. In three patients subclinical primary hypothyroidism was revealed (elevated TSH levels). Three patients who had a past history of Graves' disease were euthyroid at the time of investigation. Twenty-three patients had antibodies against peroxidase. Most patients had gonadotrophins and PRL values within normal limits. CONCLUSIONS: The co-existence of autoimmune disorders with secondary adrenal insufficiency suggests an autoimmune aetiology for the ACTH deficiency.

Adolescent↗
PubMed1998

[Clinical analysis of pneumonia treated at the hospital].

104 cases of pneumonia, treated in Department of Pulmonary Diseases of Military Medical Academy in the years 1995-1997, were analysed. Patients were divided into two groups. In the first group were 58 patients which had acute symptoms of pneumonia and the treatment was started in our department without any treatment before. In the second group were 45 patients which had acute symptoms two or three weeks before admission to hospital. In this period these patients received one or more antibiotics. The bacteriological findings and the periods of the treatment were analysed in these both groups.

Acute Disease↗
PubMed1998

[Magnetic resonance imaging: more sensitive method in the detection of leukemic central nervous system infiltration].

PURPOSE: To define the ability of magnetic resonance imaging (MRI) in identifying leukemic infiltration of central nervous system (CNS) in children. METHODS: The MRI of CNS was carried out in 54 leukemic children (mean age 8.9 years). The results were compared with CSF cytology and neurological examinations. RESULTS: Leukemic involvement of CNS (1 intracerebral infiltration, 5 meningeal intracranial infiltration, and 5 cases of intraspinal infiltration) was found in 11 children (20.4%)--6 of them were before treatment. Blasts in CSF were found only in 3 examined children. CONCLUSIONS: The results of the study implicate the importance of routine MRI screening in leukemic children. We found especially important to perform the first examination before the onset of treatment because therapy may cause very quick regression of leukemic infiltration in CNS.

Adolescent↗
PubMed1997

MRI versus CT in the diagnosis of Nelson's syndrome.

The purpose of the study was to evaluate the utility of MRI and CT in the diagnosis of Nelson's syndrome, i. e. pituitary tumours in patients bilaterally adrenalectomized for Cushing's disease. Thirteen patients, followed up for 5-29 years after adrenalectomy, were studied. In 6 of them CT and MRI revealed no changes in the pituitary gland. In the remaining 7 patients only three CT scans were suggestive of a pituitary adenoma. MRI studies with administration of gadodiamide confirmed the CT diagnosis of Nelson's tumour in 3 patients and disclosed microadenomas in a further 4 patients. Neurosurgical treatment in 4 patients confirmed the MRI findings. Additionally CT and MRI examinations were performed in 5 patients suspected of a recurrent Nelson's tumour 3-11 years after neurosurgery. MRI visualized recurrent adenomas in 3 patients that were not well seen by CT scans. In our experience MRI was more effective than CT in the diagnosis of Nelson's syndrome.

Adrenalectomy↗
PubMed1997

Colour doppler sonography guided percutaneous fine-needle biopsy of the liver.

Between 1992 and 1997, every year, approximately 30,000 examinations of the liver and bile ducts were done. Addition of colour Doppler imaging improves safety of procedures and allowed to perform ultrasound guided biopsy in 73 patients. On the basis of our experience we state that colour Doppler sonography guided percutaneous fine needle biopsy of the liver is useful, sufficient and safety diagnostic method of abscesses, cysts and malignant tumours of the liver.

Bile Ducts↗
PubMed1996

Early diagnosis of Nelson's syndrome.

Nelson's syndrome is a specific form of Cushing's disease treated by bilateral adrenalectomy, presenting with a deep hyperpigmentation caused by a pituitary adenoma (corticotropinoma). These ACTH-secreting tumors are frequently aggressive, so early diagnosis is of prime importance. We have studied 33 patients with Nelson's syndrome, 28 women and 5 men, aged 14-56 yr at the time of adrenalectomy and 16-58 yr at the time of Nelson's syndrome diagnosis (observed for 5-32 yr). Methods of examination included simultaneous adrenocorticotropic hormone (ACTH) and cortisol measurements during routine hydrocortisone replacement therapy, computed tomography (CT), pituitary magnetic resonance imaging (MRI), and visual field examination. The results obtained in a group of six patients diagnosed in the last 3 yr were compared with those obtained in a group of 27 patients examined before 1992. High plasma ACTH levels accompanied by normal serum cortisol concentration were characteristic for a late stage of the disease. Absolute temporal scotomas were an early finding. MRI, especially with the gadolinium enhancement, was superior to CT in demonstrating pituitary microadenomas in Nelson's syndrome. Thus, MRI diagnosis allowed for an early neurosurgical treatment of the patients with Nelson's tumors.

Adenoma↗
PubMed1996

The value of magnetic resonance imaging in diagnosis and monitoring of treatment in multiple sclerosis.

We analysed MR examinations of 277 patients with multiple sclerosis. White matter hyperintensities in brain were found in 270 of them. The most frequently they were found in periventricular white matter (in 100% of cases), in subcortical localization (52.2%) and in the corpus callosum (44.4%). MR examination allows to estimate the activity of the disease on the basis of the presence of oedema around the plaques and their contrast enhancement with gadopentetate dimeglumine (Gd-DTPA). 17.8% of all cases showed the signs of the acute phase of MS. About one-third of all cases were accompanied by cortical brain atrophy (the most often seen in frontal lobes), subcortical brain atrophy was less frequent (one-sixth). In about two-third of all cases the corpus callosum atrophy was found. The analysis of follow-up MR examinations of 83 patients taking part in a double-blind placebo-controlled trial of a new immunosuppressive drug cladribine showed that patients from the placebo group were more compliant to any changes of the plaques. Decrease of the plaques size was found mainly in women. No correlation between the patients age and the plaques changes was established.

Adolescent↗
PubMed1996

[Evaluation of the usefulness of magnetic resonance imaging after correction of congenital heart disease in children--pilot experiment].

Magnetic resonance imaging is the next in a succession of noninvasive methods for evaluation of the heart and great vessels after total correction in congenital heart disease and percutaneous interventional cardiology procedures. Between October 1994 to March 1995 we performed 28 magnetic resonance investigations in children after surgical treatment of coarctation of the aorta and after Senning, Rastelli and Fontan procedures. Five children after correction of coarctation of the aorta were qualified for balloon angioplasty. After hemodynamic evaluation and aortography, balloon angioplasty was done in 3 children. In children after Senning, Rastelli and Fontan procedures no postoperative abnormalities were detected. Magnetic resonance imaging is a usefull, noninvasive method in long-term follow-up of patients after total correction in congenial heart disease.

Adolescent↗
PubMed1992

Intracranial volume reserve determination using CT images, numerical analysis and lumbar infusion tests. An experimental study.

The epidural balloon compression model in the cat was used in intracranial volume reserve studies. The evaluation of the intracranial volume-pressure relations was based on the lumbar infusion test data: intracranial pressure, CSF outflow resistance, volume-pressure response and on CT images numerical analysis (CTINA) values. Two methods were applied and compared in the study: lumbar infusion test and CT images numerical analysis. The determinations were performed at the balloon volumes of 0.5 ml, 1.0 ml, and 1.5 ml. First statistically significant changes were found at the balloon volume of 0.5 ml i.e. the increase of CSF outflow resistance and volume-pressure response (data obtained in lumbar infusion test) and the decrease in CTINA values. The rise of intracranial pressure was less informative as it was observed at the balloon volume of 1.5 ml. Therefore CTINA seems to be a very useful noninvasive screening method in clinical studies of intracranial volume reserve.

Animals↗
PubMed1992

[Superiority of magnetic resonance imaging (MRI) over computerized tomography (CT) in diagnosis of hypopituitarism].

Hypopituitarism can be a result of various lesions of hypothalamus, pituitary stalk, or of the pituitary gland itself. The aim of the study was to assess the value of CT and MRI examinations in determination of the cause of hypopituitarism. Seventeen patients with hypopituitarism (9 women and 8 men) aged 22 to 61 years have been examined. In three cases growth deficiency was observed, 4 women had galactorrhoea, 4 patients had diabetes insipidus, 16 patients had supra-adrenal insufficiency, 14 had signs of hypogonadism and 10 hypothyroidism. In each case plasma concentrations of LH, FSH, PRL, TSH, alpha-subunit, ACTH before and after appropriate stimulation with TRH, metoclopramid, LH-RH, GRF or metyrapon were determined with RIA. Every patient was examined both with CT and MRI (0.5 T Toshiba MRT 50a). All 17 patients had abnormal MR images of hypothalamo-pituitary area, while only 10 of them had abnormalities in their CT scans. In remaining 7 patients the MRI revealed: three cases of congenital malformation of hypophyseal stalk, two cases of empty sella, one posttraumatic lesion of the stalk and one case of granulomatous infiltration of the stalk. We found MRI superior to CT in establishing the case of hypopituitarism.

Adult↗