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Biomedical subjects

J Jelinek

Publications and source records attributed to J Jelinek.

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

Ultrasound-guided fine-needle aspiration and thyroid disease.

BACKGROUND: Fine-needle aspiration represents a critical diagnostic test in determining proper management of thyroid disease and the use of ultrasound-guided fine-needle aspiration (USGFNA) has increased over the years. METHODS: A retrospective chart review of patients undergoing USGFNA. Two hundred fifteen patients underwent 234 procedures with 362 nodules aspirated within a 2 (1/2)-year period. RESULTS: The mean ages of women and men were 51.9 and 57.8, respectively. The average size of nodules was 2.1 cm. A difficult to assess gland or nodule was the most common indication for USGFNA (33%). The sensitivity was 88.2%, specificity was 80.0%, the PPV was 65.2%, the negative predictive value was 94.1%, and the accuracy was 82.5%. The cancer yield, inadequacy, and complication rates were 44%, 10.5%, and 8.5%, respectively. CONCLUSIONS: USGFNA aspiration is a safe and effective diagnostic modality in the management of thyroid disease, especially for nodules that are difficult to palpate.

Biopsy, Needle↗
PubMed1999

A novel dual function retrovirus expressing multidrug resistance 1 and O6-alkylguanine-DNA-alkyltransferase for engineering resistance of haemopoietic progenitor cells to multiple chemotherapeutic agents.

Following transduction with a retrovirus (SF1MIH) expressing both the multidrug resistance 1 (MDR1) and O6-alkylguanine-DNA-alkyltransferase (ATase) proteins, human erythroleukaemic progenitor (K562) cells were isolated which were resistant to killing by the MDR1 substrate, colchicine. In colony-forming survival assays, K562-SF1MIH cells exhibited resistance to colchicine and doxorubicin, as well as to the O6-alkylating agents N-Methyl-N-nitrosourea (MNU) and temozolomide. Furthermore, the resistance to doxorubicin was abolished by preincubation with the MDR1 inhibitor verapamil while resistance to MNU was ablated by the specific ATase inactivator, O6-benzylguanine (O6-beG) confirming that resistance to doxorubicin and MNU was conferred by MDR1 and ATase, respectively. When K562-SF1MIH were exposed to combinations of colchicine and MNU or doxorubicin and temozolomide, simultaneous resistance to these agents was observed. Thus, transduction of K562 with SF1MIH conferred dual resistance to these cells. These data offer the prospect of designing vectors that will confer resistance to entire regimens of chemotherapy rather than just to individual components of such drug cocktails, thereby substantially increasing the efficacy of therapy. Furthermore, the use of such dual expression constructs is likely to be highly informative for the design of effective in vivo selection protocols, an issue likely to make a major impact in a clinical context in gene therapy in the near future.

Antineoplastic Agents↗
PubMed1999

Postprandial plasma amino acids in preterm infants: influence of the protein source.

Preprandial plasma amino acid concentrations have been used extensively as a marker of the nutritional value of dietary proteins in preterm infants. This study investigated the postprandial plasma amino acid profiles of preterm infants fed with different dietary proteins at similar protein intakes during the first weeks of life. In 12 preterm infants, pre- and postprandial plasma amino acid concentrations were measured before the removal of an indwelling central venous catheter placed for parenteral nutrition. All infants received breast milk until the time of study. At the start day of the study, infants were randomized to receive a test meal of 10 ml/kg, either of breast milk fortified with breast milk protein to reach a protein content of 2.0 g/dl or of a bovine milk preterm formula with a protein content of 2.0 g/dl (whey/casein ratio 60/40). Five samples of 100 microl blood were obtained immediately before and 15, 30, 45 and 60 min after the test meal. The plasma amino acid analysis was performed by a reversed-phase high-performance liquid chromatography based on o-phthaldialdehyde/2-mercaptoethanol pre-column derivatization. In both groups, the plasma amino acid concentrations increased within the first 30 min and the levels did not return to the preprandial baseline during the observation period. Fifteen minutes after the test meal, the plasma levels of all essential amino acids with the exception of histidine were higher in the bovine milk formula fed infants than in the fortified breast milk fed infants. The sum of plasma essential amino acid levels found in the formula fed infants were significantly (p < 0.05) higher than the levels found in the fortified breast milk fed infants at 15, 30 and 45 min. The kinetics of individual amino acids were influenced by the different quality of the protein even when the intakes in the groups were similar, as demonstrated for histidine and phenylalanine. The data indicate that postprandial plasma amino acid concentrations depend significantly on the dietary amino acid source and cannot simply be calculated from the amino acid composition of dietary proteins. Therefore, postprandial plasma amino acid concentrations should be included in the nutritional evaluation of dietary proteins in preterm infants.

Amino Acids↗
PubMed1998

Effect of increasing dietary threonine intakes on amino acid metabolism of the central nervous system and peripheral tissues in growing rats.

The threonine content of most of the infant formulas currently on the market is approximately 20% higher than the threonine concentration in human milk. Due to this high threonine content the plasma threonine concentrations are up to twice as high in premature infants fed these formulas than in infants fed human milk. To study the effect of different threonine intakes on plasma and tissue amino acid concentrations, 24 young male Wistar rats were fed three experimental diets based on a mixture of bovine proteins with a whey protein/casein ratio of 60/40 with different threonine contents [group A, 0.86 g of threonine/100 g (n = 8); group B, 1.03 g of threonine/100 g (n = 8); group C, 2.21 g of threonine/100 g (n = 8)]. Eight animals were fed a typical rat diet based on bovine casein as controls. After a feeding period of 15 d, amino acids were measured in plasma and in homogenates of the cerebral cortex, brain stem, liver, and muscle. There was a significant correlation between threonine intake and plasma threonine levels (r = 0.687, p < 0.001). The plasma threonine concentration correlated significantly with the threonine concentration in the cortex (r = 0.821, p < 0.01) and the brain stem (r = 0.882, p < 0.01). There was a positive significant correlation between threonine and glycine concentrations in the cortex (r = 0.673, p < 0.01), and the brain stem (r = 0.575, p < 0.01), whereas the glycine concentration decreased with increasing threonine intakes in the liver and muscle. The presented data indicate that increasing the threonine in plasma leads to increasing brain glycine and thereby affects the neurotransmitter balance in the brain. This may have consequences for brain development during early postnatal life. Therefore, excessive threonine intake during infant feeding should be avoided.

Amino Acids↗
PubMed1996

Neuropathy secondary to pigmented villonodular synovitis of the hip.

Pigmented villonodular synovitis is a benign proliferative process of unknown origin that may cause extensive bone and joint destruction. Patients with this condition typically present with symptoms of mild discomfort and associated stiffness of the involved joint; however, the spectrum of presentations is broad. Although pigmented villonodular synovitis begins in, and usually is confined within, a synovium-lined joint, it may extend beyond the joint capsule and present as a soft tissue mass. Three cases of a previously unrecognized presentation of pigmented villonodular synovitis of the hip joint are presented. The authors believe these to be the first reported cases in the English language literature of pigmented villonodular synovitis of the hip seen with femoral or sciatic neuropathy.

Adult↗
PubMed1995

Accounting for variance shared by measures of personality and stress-related variables: a canonical correlation analysis.

Correlations were computed among the five personality scales of the NEO Personality Inventory, two measures derived from the Hassles Scale, and eight ways of dealing with stress measured by the Ways of Coping Questionnaire. Subjects were 66 undergraduate psychology students. Canonical correlation analysis suggests that multivariate procedures treating the data set as a whole can detect underlying patterns obscured by large sampling errors at lower levels of analysis.

Adaptation, Psychological↗
PubMed1995

MR imaging of soft-tissue masses. Mass-like lesions that simulate neoplasms.

The MR appearance of soft-tissue masses that simulate neoplasms has been described. In some cases, radiographs may demonstrate characteristic findings in association with MR imaging that may be diagnostic, such as an ossific rim seen in myositis ossificans, periosteal reaction seen in fibro-osseous pseudotumor, and retained foreign bodies present in a foreign body reaction or abscess. In other cases, the characteristic lesion location, age of the patient, and clinical presentation may be suggestive of the diagnosis, as in elastofibroma and nodular fasciitis.

Contusions↗
PubMed1991

Regional brain blood flow and oxygen supply in guinea pig fetuses near term.

To examine brain blood flow and oxygen supply to 14 brain regions in fetal guinea pigs near term, 6 fetuses were catheterized under general anaesthesia of the dam between days 61 and 63 of pregnancy. Fetal arterial blood pressure was measured and a blood sample was taken from the right axillary artery to determine fetal blood gases and acid-base balance. Isotope-labelled microspheres were then injected in a lateral saphenous vein and a reference blood sample was taken from the right axillary artery according to Carter and Gu. Preductal arterial haemoglobin oxygen saturation ranged from 16-33% (26.7 +/- 6.3 mean +/- SD) and pH from 7.08-7.30 (7.20 +/- 0.09); oxygen content varied between 3.0-6.7 ml/dl. Blood flow to the whole brain was 105-258 ml/min per 100 g (167 +/- 58), oxygen supply to the brain was 6.6-10.7 ml O2/min per 100 g (8.0 +/- 1.6). Both regional brain blood flow and oxygen supply were significantly different in the various brain parts. They were highest in the spinal medulla and in other parts of the brain stem and lowest in the cerebrum. Brain blood flow increased significantly with increasing pCO2 and systolic blood pressure and with decreasing haemoglobin oxygen saturation, pH, base excess, and arterial oxygen content. On the other hand, except for the mid portion of the spinal medulla, there were no correlations between blood gas and acid-base balance variables and the oxygen supply to the whole brain or to various regions of the brain.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1991

Localization of metastatic adrenal cortical carcinoma with Ga-67.

Data are limited on the localization of Ga-67 in primary or metastatic adrenal cortical carcinoma. We report the localization of Ga-67 to pathologically confirmed adrenal cortical carcinoma metastatic to the lung. A review of the literature revealed four patients have previously been reported to have metastatic adrenal cortical carcinoma detected on Ga-67 scan. Gallium imaging may be useful in the evaluation of patients with adrenal cortical carcinoma. SPECT imaging should further improve lesion resolution and localization.

Adrenal Cortex Neoplasms↗
PubMed1991

Catecholamine concentrations in plasma and organs of the fetal guinea pig during normoxemia, hypoxemia, and asphyxia.

To examine the responses of the sympatho-adrenal system to reduced oxygen supply we studied plasma and tissue concentrations of catecholamines during normoxemia, hypoxemia, and asphyxia in 22 fetal guinea pigs near term. Fetal blood was obtained by cardiopuncture in utero under ketamine/xylazine-anesthesia. Catecholamines were determined in plasma and tissue of 15 organs and 14 brain parts by HPLC-ECD. During normoxemia (SO2 54 +/- 4 (SE) %, pH 7.36 +/- 0.02, n = 5) plasma catecholamine levels were low (norepinephrine 447 +/- 53, epinephrine 42 +/- 12, dopamine 44 +/- 6 pg/ml). During hypoxemia (SO2 27 +/- 3%, pH 7.32 +/- 0.01, n = 6) and asphyxia (SO2 24 +/- 2%, pH 7.23 +/- 0.02, n = 11) tissue catecholamine concentrations changed with changing blood gases and with increasing plasma catecholamines. Norepinephrine concentrations increased in both skin and lung and decreased in liver, pancreas, and scalp; those of epinephrine increased in the heart, lung liver, and scalp and decreased in the adrenal. There were only minor changes in brain catecholamine concentrations except for a 50% reduction in dopamine in the caudate nucleus. Concentrations of dopamine catabolite 3,4-dihydroxyphenylacetic acid decreased in many brain parts, suggesting that cerebral catecholamine metabolism was affected by hypoxemia and asphyxia. We conclude that the sympatho-adrenal system of fetal guinea pigs near term is mature and that its stimulation by reduced fetal oxygen supply leads to changes in both plasma and tissue catecholamine concentrations.

Acid-Base Equilibrium↗
PubMed1990

Lateral ventricular neoplasms of the brain: differential diagnosis based on clinical, CT, and MR findings.

The differential diagnosis of lateral ventricular tumors was explored by retrospective analysis of 47 pathologically proved cases identified by CT and/or MR imaging. Third ventricular tumors adjacent to the foramen of Monro (e.g., colloid cysts) were excluded. Forty-six patients underwent CT, and eight had MR imaging. The most common neoplasms were choroid plexus papilloma (10 cases) and meningioma (nine cases). Other common neoplasms included subependymoma (six cases), subependymal giant cell astrocytoma (five cases), and metastasis/lymphoma (four cases). Important features for differential diagnosis included age of the patient, the tumor's location within the lateral ventricle, and density on CT before IV administration of contrast material. Fifty percent of the tumors were in the ventricular atrium. All intraventricular tumor types (except subependymoma) showed contrast enhancement. MR was most useful in evaluating tumor location, size, and extent, but it did not help in eliminating alternative diagnoses. On the basis of patients' ages, specific tumor location, and the appearance on CT scans or MR images, an algorithm for differential diagnosis of lateral ventricular tumors was developed.

Adolescent↗