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Biomedical subjects

J Andres

Publications and source records attributed to J Andres.

At least 19 recordsLinked to original sources
PubMed2006

Free fatty acids increase androgen precursors in vivo.

CONTEXT: There is considerable evidence that metabolic factors such as insulin resistance may induce hyperandrogenemia in polycystic ovary syndrome. However, other metabolic factors such as free fatty acids (FFAs) may also contribute to androgen excess. OBJECTIVE: The objective was to study effects of FFAs on adrenal production of androgen precursors in vivo. DESIGN AND PARTICIPANTS: We investigated eight healthy young men, because male individuals produce the androgen precursors dehydroepiandrosterone (DHEA), DHEA sulfate, and androstenedione predominantly in the adrenal gland. A randomized controlled crossover trial was performed. INTERVENTION: After a 10-h overnight fast, 20% lipid/heparin or saline/heparin infusion was given at a rate of 1.5 ml/min. Four hours after start of lipid infusion, a euglycemic hyperinsulinemic clamp was performed. MAIN OUTCOME MEASURES: DHEA, androstenedione, 17-OH-progesterone, testosterone, estrone, LH, FSH, ACTH, and cortisol were measured. RESULTS: The adrenal androgen precursors DHEA and androstenedione showed a circadian decline during saline/heparin infusion (P < 0.05 vs. baseline, respectively), whereas no significant changes were observed during lipid/heparin infusion (P = not significant vs. baseline, respectively). Correspondingly, DHEA and androstenedione values were significantly elevated during lipid compared with saline infusion (P < 0.05, respectively), and areas under curve of both androgen precursors were significantly increased with lipid compared with saline infusion. Notably, all changes were detected before induction of insulin resistance. CONCLUSIONS: This study demonstrates that FFAs increase production of androgen precursors in vivo in men. These data tentatively suggest that hyperandrogenemia in polycystic ovary syndrome may be induced, at least in part, by elevated FFAs.

17-alpha-Hydroxyprogesterone↗
PubMed2001

Stress proteins in cardiovascular research.

This review article is dealing with the most important aspects of stress proteins expression in cardiovascular research focused mainly on myocardial ischaemia and reperfusion. The major role of heat shock protein 70 kDa in endogenous route of myocardial protection is widely discussed in the context of possible contribution of other stress proteins. On the basis of numeral classical and recent published scientific data the problem of cellular response to stress and its possible clinical implication are presented.

Animals↗
PubMed2001

[Point systems for evaluating coma in patients with injuries of the central nervous system (CNS)].

Paper reviews various coma scales which are used to monitor consciousness after sustaining severe injuries of CNS. Glasgow Coma Scale, at present the most frequently used, was compared to recently developed scales, which are more useful for monitoring persistent comas, allows to evaluate discrete changes in patient's state more precisely and to predict the outcome. The necessity of evoked potentials' measurements, such as Trigeminal-Auditory Glasgow (Coma Scale) has been stressed.

Brain Injuries↗
PubMed2001

[Experiments in evaluation of brain oxygenation and metabolism based on continuous bilateral SjO2 monitoring and metabolic glucose transformations in patients after severe cranio-cerebral injuries].

The study group consisted of 17 patients after severe cranio-cerebral injuries-in GCS below 8. Saturation in both jugular bulbs was measured by using fiberoptic catheters, the concentration of lactate taken from jugular bulbs was measured too. These values were compared to concentration in peripheral arteries. All measurements were started within the first 24 h after trauma and lasted 5 days. Diagnosis of intracranial pathology was established by using CT, which was done directly after admission to the hospital. Interdependence between the state of patient in GOS and variability saturation and concentration of lactate was showed. Desaturation occurred before the neurological sings of intracranial hypertension what had influence on way of treatment and diagnostics. Bilateral measurement of the saturation is more useful to make diagnostic unilateral measurement.

Adult↗
PubMed2001

[The influence of anesthesia methods on appearance of perioperative complications in patients after lung parenchyma resection].

We analyzed the influence of different methods of anaesthesia on perioperative complications in 184 patients (ASA 1 and 2) anaesthetized with intermittent one lung ventilation for pulmonary resection. Depends on the method of anaesthesia patients were divided into 3 groups: Group 1--patients under inhalation anaesthesia, Group 2--patients under mixed inhalation and intravenous anaesthesia and Group 3 patients anaesthetized intravenously. The analysis of intra- and postoperative data showed no correlation between perioperative complications and methods of anaesthesia, when the appropriate technique of anaesthesia has been used.

Adult↗
PubMed2001

[Mivacurium--use for complications of facial-cranial surgery--personal experience].

The aim of this study was to evaluate the effectiveness of mivacurium (Mivacron--GlaxoWellcome) during combined general anaesthesia in the operations on the facial cranium, after tracheal intubation performed using suxamethonium chloride (Chlorsuccillin--Polfa PL). We examined 20 patients, 17-65 years old, who were underwent operations due to facial and neck neoplasms or trauma. Patients were divided into two 10-person groups. In first group the dose of Mivacron for the induction of anaesthesia was 0.15 mg/kg of body weight, in second group the dose was 0.1 mg/kg of body weight. Next doses used during maintenance of anaesthesia were 0.1 mg/kg of body weight in both groups. Metohexital, fentanyl, nitrous oxide and oxygen were used for the maintenance of anaesthesia. The level of neuromuscular block was estimated using Ministim MS IIIA instrument. The mean time to maintain 95-99% neuromuscular block after inductive dose 0.15 mg/kg Mivacron was 15 minutes 26 seconds, and after the dose of 0.1 mg/kg--13 minutes 55 seconds. The time from the injection of the drug to maintain neuromuscular block was 1 minute 52 seconds and 1 minute 50 seconds, respectively. We did not observe neither negative influence of drug on the cardiovascular system nor the reactions of histamine release. Injection of suxamethonium chloride before the tracheal intubation did not prolong the time of Mivacron activity. Anticholinesterase agents was not use in any case. By 4 patient with heart failure prolongation of the activity time of Mivacurium was observed. The dose of 0.1 mg/kg, is efficient to maintain of the neuromuscular block on the stabile level. This allows the reduction of the total dose, and the decrease of the costs of the operation.

Adolescent↗
PubMed2001

[Presence of the trace elements from carbon dioxide absorbent containing lime using a circular apparatus during general anesthesia. ].

The aim of the study was to evaluate release of the trace elements from carbon dioxide absorbent containing soda lime during general anesthesia. We compared two suppliers Polish "Polfa" and German "Dräger". Following trace elements were evaluated: chromium, copper, zinc, cadmium, lead, nickel in soda lime. In blood of the patients we evaluated: copper, zinc, lead, cadmium, bromine, rubidium, iron, mercury. Proton Induced X-ray Emission (PIXE) was used to measure concentrations of the elements. Probes of soda lime were analyzed before anesthesia (Polfa, Dräger), 6 hr after the use (Polfa only) and after 10 weeks (Dräger only). 10 patients were divided in two equal groups, one was anesthetized using soda lime from Polfa and another one from Dräger. Blood samples were taken before anesthesia, immediately after and the next day. Mean values of the concentrations of the elements in soda lime coming from Polfa ranged from 0.20 ppm (nickel) to 7.19 ppm (zinc). In Dräger the measurements were from 0.22 ppm (nickel) to 3.70 ppm (zinc). Mean concentrations of trace elements in blood samples were between 0.20 ppm (lead) and 487 ppm (iron) for the patients anesthetized with Polfa soda lime. In Dräger the measurements ranged from 0.15 ppm (lead) to 485 ppm (iron). Concentrations of cadmium and mercury were below the method's limit. Mean values were almost the same in all time points. Statistical analysis was done using paired t-tests. Values of P < 0.05 were consider significant. We concluded that there were no statistically significant differences between examined groups. Thus, we can say that trace elements were not released from soda lime and concentrations of examined elements in patients' blood were not affected by general anesthesia.

Absorption↗
PubMed2001

[Morphine--myths and facts].

Morphine in the form of opium tincture accompanies the mankind for several thousands years. At the beginning of the twentieth century morphine has been isolated from opium and it was used initially to treat ... opium addicts. At present it plays an important role in the treatment of severe pain of different origins and (more seldom) in the premedication for general anaesthesia. Despite its side effects it is irreplaceable especially in the treatment of cancer pain. Nowadays the chronic use of oral morphine preparations has been supported by medical authorities who at the same time warn against incorrect dosage and combination with other drugs. Many clinical data concerning oral morphine show that it is safe and effective even in the patients with advanced cancer and poor performance status. Our paper lists myths and common mistakes connected with morphine use and confronts them with well established facts confirming its effectiveness in cancer pain treatment.

Administration, Oral↗
PubMed2001

[Levels of troponin I, tropoinin T, isoenzyme MB creatine kinase and myoglobins in blood serum for perioperative diagnosis of myocardial infarction in patients after coronary artery bypass graft surgery with extracorporeal circulation].

UNLABELLED: We studied plasma levels of troponin I (cTnI), troponin T (cTnT), creatine kinase MB (CKMBmass) and myoglobin (MB) in patients undergoing coronary artery bypass surgery with extracorporeal circulation and cardioplegia. In group 1 (25 patients without perioperative myocardial infarction) plasma levels of all markers studied were elevated after operation. In group 2 (24 patients with perioperative myocardial infarction) plasma concentrations of all markers exceeded several times levels observed in patients without myocardial infarction with maximal value for MB at 12 hours after operation; for cTnI and CKMBmass at 16 hours after surgery and for cTnT at 32 hours after the end of operation. ROC curves show cut-off value for CKMBmass 20.3 ng/ml (sensitivity 79% and specificity 89%); for cTnI cut-off value was 0.8 ng/ml (sensitivity 80% and specificity 94%) for cTnT the cut-off value was 0.41 ng/ml (sensitivity 86% and specificity 88%) and for MB the cut-off value was 419 ng/ml (sensitivity 85% and specificity 70%). CONCLUSION: All markers studied are reliable biochemical tests for perioperative myocardial infarction, however, the analysis of ROC curves suggested that cTnI and cTnT might be more useful for diagnosis of perioperative myocardial infarction after conventional coronary artery bypass surgery.

Aged↗
PubMed2000

Toward an understanding of the selectivity in domino reactions. A DFT study of the reaction between acetylenedicarboxylic acid and 1, 3-Bis(2-furyl)propane

The mechanism of the domino reaction between acetylenedicarboxylic acid and 1,3-bis(2-furyl)propane has been theoretically studied in the framework of density functional theory. This domino process comprises two consecutive cycloaddition reactions: the first one is initialized by the nucleophilic attack of the C5 position of the furan ring to a conjugate position of acetylenedicarboxylic acid to give a zwitterionic intermediate, which by a subsequent ring-closure process affords an oxanorbornadiene intermediate. The second reaction is an intramolecular concerted cycloaddition of this intermediate to give the final dioxapentacyclic adduct. For the second cycloaddition, which corresponds to the step controlling the selectivity, eight alternative reaction pathways are found. Chemoselectivity, facial selectivity, and stereoselectivity of this domino reaction are related with the different approach modes of the tethered furan to the oxanorbornadiene system of the intermediate. The most favorable pathway takes place along an endo/syn approach of the furan ring relative to the bridged oxygen atom of the oxanorbornadiene system, with participation of the substituted double bond. An analysis of energetic contributions to the potential energy barriers for the intramolecular cycloadditions identifies the different factors controlling the reactive channels. Selectivity outcome is reproduced by these calculations.

Journal Article↗
PubMed2000

Circadian changes of heart rate in West syndrome.

Patterns of circadian and ultradian rhythms in the heart rate (HR) are described in a full-term baby with birth asphyxia and convulsions. A 24h HR recording was carried out at the age of 1, 15, 56, 289, and 295 days; West syndrome diagnosis was made when the patient was 3 months old. The HR showed no circadian rhythm in the follow-up, whereas it is known that the circadian rhythm appears in healthy infants at the age of 1 month and remains thereafter. This observation may be an indirect indicator of the interference of West syndrome with centers of neurological maturity.

Activity Cycles↗
PubMed1999

[Use of polymerase chain reaction in medical diagnosis].

Principles of the polymerase chain reaction (PCR) and its modifications are discussed: reverse transcription-PCR (RT-PCR), nested PCR, restriction fragment length polymorphism-PCR (RFLP-PCR). Different methods of the PCR products detection used in routine diagnostics and research are presented: electrophoresis and chromatography techniques, immunoenzymatic methods, hybridisation and sequencing. Applications of PCR reaction in diagnostics of infectious diseases (viral and bacterial), genetic diseases and genotyping in transplantation are discussed and examples of commercial tests based on PCR reaction and another molecular biology methods used in fast, routine diagnostics are listed.

Acquired Immunodeficiency Syndrome↗
PubMed1998

Down-regulation of BRCA1 and BRCA2 in human ovarian cancer cells exposed to adriamycin and ultraviolet radiation.

Germ-line mutations of the BRCA1 and BRCA2 genes predispose women to develop cancers of the breast and ovary, but the biologic functions of these genes remains unclear. We have investigated the responses of the BRCA1 and BRCA2 gene products to cytotoxic agents in 3 human ovarian cancer cell lines: SK-OV-3 (which contains a p53 deletion mutation), CAOV-3 (which over-expresses a mutant p53) and PA-1 (which expresses wild-type p53). In screening studies, we determined the effects of 7 different agents on BRCA1 and BRCA2 expression. We found that Adriamycin (ADR) and ultraviolet (UV)radiation significantly down-regulated BRCA1 and BRCA2 mRNA expression in SK-OV-3 cells. On the other hand, camptothecin, nitrogen mustard, taxol, vincristine and etoposide had no effect on BRCA1 or BRCA2 mRNA levels at doses that yielded degrees of cytotoxicity similar to or greater than ADR. The down-regulation of BRCA1 and BRCA2 mRNAs was dose and time dependent; significant down-regulation was first observed at 8-16 hr after exposure to ADR. BRCA1 protein levels were also down-regulated following treatment of SK-OV-3 cells with ADR. Similar results were observed in CAOV-3 and PA-1 cells treated with ADR, and this finding could not be directly attributed to ADR-induced changes in the cell cycle distribution. The ADR doses required for significant decreases of BRCA1 and BRCA2 were about 10-15, 5-10 and 2 microM, respectively, for SK-OV-3, CAOV-3 and PA-1; the IC50 doses for loss of cell viability (determined by Trypan blue dye exclusion) were 23, 14 and 0.4 microM, respectively. Thus, at equitoxic doses of ADR, PA-1 cells were more resistant to down-regulation of BRCA1 and BRCA2 than SK-OV-3 or CAOV-3. Our findings suggest that 1) BRCA1 and BRCA2 expression in human ovarian cancer cell lines is selectively down-regulated by 2 DNA-damaging agents (ADR and UV radiation); 2) these responses are not due to non-specific cytotoxicity; and 3) the BRCA1 and BRCA2 responses may be dependent, in part, on the p53 functional status of the cells. We speculate that the down-regulation of BRCA1 and BRCA2 may be part of a cellular survival response activated by certain forms of DNA damage.

Antibiotics, Antineoplastic↗
PubMed1998

Scatter factor protects epithelial and carcinoma cells against apoptosis induced by DNA-damaging agents.

Scatter factor (SF) (hepatocyte growth factor) is a cytokine that may play a role in human breast cancer invasiveness and angiogenesis. We now report that SF can block the induction of apoptosis by various DNA damaging-agents, including cytotoxic agents used in breast cancer therapy. SF protected MDA-MB-453 human breast cancer cells, EMT6 mouse mammary tumor cells and MDCK renal epithelial cells against apoptosis induced by adriamycin (ADR), X-rays, ultraviolet radiation, and other agents. Protection was observed in assays of DNA fragmentation, cell viability (MTT), and clonogenic survival. Protection of MDA-MB-453 cells against ADR was dose- and time-dependent; maximal protection required pre-incubation with 75-100 ng/ml of SF for 48 h or more. Protection required functional SF receptor (c-Met), but was not dependent on p53. Western blotting analysis revealed that pre-treatment of MDA-MB-453 cells with SF inhibited the ADR-induced decreases in the levels of Bcl-XL, an anti-apoptotic protein related to Bcl-2; and the dose-response and time course characteristics for SF-mediated increases in the Bcl-XL protein levels of ADR-treated cells were consistent with the degrees of protection against apoptosis observed under the same conditions. Furthermore, Bcl-XL levels were not down-regulated by ADR in MDA-MB-231 breast cancer cells, consistent with the finding that SF failed to protect these cells against ADR, despite the fact that they contain functional c-Met receptor. In contrast to Bcl-XL, SF blocked ADR-induced increases in c-Myc and inhibited the expression of p21WAF1/CIP1 and of the BRCA1 protein in MDA-MB-453 cells. However, SF did not cause significant changes in the cell cycle distribution of ADR-treated cells. These findings suggest that SF-mediated protection of human breast cancer cells may involve inhibition of one or more pathways required for the activation of apoptosis and may particularly target the anti-apoptotic mitochondrial membrane pore-forming protein Bcl-XL as a component of the protective mechanism. By implication, the accumulation of SF within human breast cancers may contribute to the development of a radio- or chemoresistant phenotype.

Animals↗
PubMed1998

[Persistent vegetative state: medical, moral, legal and economic aspects].

The classical definition of persistent vegetative state describes patient who is wakeful but not awake, and indicates intact function of the brain stem and no function of brain cortex. The presence and the degree of awareness is most difficult to assess and causes moral and legal controversies concerning the management of persistent vegetative state. The absence of the perceptual awareness may be the most important clinical characterization for diagnosis. Differential diagnosis includes coma, brain death, locked-in syndrome and minimally responsive state. The pressure of economical factors (managed care) on medical care makes this problem even more complicated.

Brain Death↗
PubMed1997

Expression of interleukin-1beta in human breast carcinoma.

BACKGROUND: Interleukin 1beta (IL-1beta) is a multifunctional cytokine that up-regulates the inflammatory response. It is not known whether IL-1beta plays a major role in human malignancy. To determine whether IL-1beta might be involved in breast carcinoma progression, the authors measured the IL-1beta content in tissue extracts from >200 invasive breast carcinomas and smaller numbers of ductal carcinoma in situ (DCIS) and benign lesions. METHODS: IL-1beta content was measured by an enzyme-linked immunoadsorbent assay and analyzed to determine whether these values were correlated with the contents of scatter factor (SF) (an invasogenic and angiogenic cytokine), von Willebrand's factor (VWF) (a marker of endothelium), thrombospondin-1 (TSP1) (an antiadhesive and antiangiogenic glycoprotein), and tumor necrosis factor-alpha (TNF alpha) (another proinflammatory cytokine). Studies were also performed to determine whether IL-1beta content was correlated with other pathologic and immunochemical variables that have been utilized or proposed as prognostic indicators for breast carcinoma. RESULTS: The most important findings of these studies were: 1) immunoreactive IL-1beta was detected in approximately 90% of invasive breast carcinomas; 2) IL-1beta levels were significantly higher in invasive carcinomas than in a group of DCIS and benign lesions; 3) high IL-1beta content in invasive carcinomas was significantly associated with higher contents of SF, VWF, and TSP1, but not TNF alpha; and 4) there was a trend toward higher IL-1beta content in invasive carcinomas with a group of other parameters that suggest a biologically more aggressive tumor (estrogen receptor negativity, high tumor grade, p53 positivity, and bcl-2 negativity); and the proportion of invasive tumors with these characteristics was significantly increased in a subgroup of tumors having very high IL-1beta content. The authors also found a correlation between high IL-1beta content and CD68 positivity, suggesting that macrophages may account for some of the IL-1beta present in human breast carcinoma tissue. CONCLUSIONS: These findings suggest that significant titers of IL-1beta are present within the microenvironment of most breast carcinomas and that a high IL-1beta content is often associated with tumor invasiveness and with other pathologic features suggestive of an aggressive tumor biology.

Biomarkers↗