COMPARISON OF PLASMA PHENYLALANINE DETERMINATION BY DENSITOMETRY OF THIN-LAYER CHROMATOGRAMS AND BY HIGH PERFORMANCE LIQUID CHROMATOGRAPHY IN RELATION WITH THE SCREENING OF PHENYLKETONURIA.

OBJECTIVE: To compare two chromatographic methodologies for determination of plasma phenylalanine (Phe) and their usefulness for diagnosing hyperphenylalaninemia (HPA) and phenylketonuria (PKU). METHODS: The plasma amino acids were isolated and concentrated from blood collected from infants with HPA detected by newborn screening. The plasma Phe was determined in parallel by HPLC and by image-densitometry of 2D-TLC plates. RESULTS: Typical examples of 2D-TLC plates and HPLC chromatograms from infants with HPA and PKU are presented and evaluated. The Phe spot was visible on 2D - TLC plates at Phe concentrations higher than 300 µmol/L. The standard calibration curve traced after image-densitometry of the Phe spot presented high dispersion of values at each concentration of Phe, high SD values, the equation of the curve having a low R-squared value (0.862). In contrast, the standard calibration curve obtained by HPLC shows linearity on the range of concentrations from 100 - 16,000 µmol/L, extremely small SD values, the equation of the curve has a very high R-squared value (0.999). CONCLUSIONS: The HPLC methodology is appropriate to confirm HPA detected by newborn or selective screening of PKU. The 2D - TLC methodology is adequate to detect patients with severe PKU.

Large composite fermion effective mass at filling factor 5/2.

The 5/2 fractional quantum Hall effect in the second Landau level of extremely clean two-dimensional electron gases has attracted much attention due to its topological order predicted to host quasiparticles that obey non-Abelian quantum statistics and could serve as a basis for fault-tolerant quantum computations. While previous works have establish the Fermi liquid (FL) nature of its putative composite fermion (CF) normal phase, little is known regarding its thermodynamics properties and as a result its effective mass is entirely unknown. Here, we report on time-resolved specific heat measurements at filling factor 5/2, and we examine the ratio of specific heat to temperature as a function of temperature. Combining these specific heat data with existing longitudinal thermopower data measuring the entropy in the clean limit we find that, unless a phase transition/crossover gives rise to large specific heat anomaly, both datasets point towards a large effective mass in the FL phase of CFs at 5/2. We estimate the effective-to-bare mass ratio m*/me to be ranging from ~ 2 to 4, which is two to three times larger than previously measured values in the first Landau level.

Anomalous electronic transport in high-mobility Corbino rings.

We report low-temperature electronic transport measurements performed in two multi-terminal Corbino samples formed in GaAs/Al-GaAs two-dimensional electron gases (2DEG) with both ultra-high electron mobility ( ≳ 20 × 106 cm2/ Vs) and with distinct electron density of 1.7 and 3.6 × 1011 cm-2. In both Corbino samples, a non-monotonic behavior is observed in the temperature dependence of the resistance below 1 K. Surprisingly, a sharp decrease in resistance is observed with increasing temperature in the sample with lower electron density, whereas an opposite behavior is observed in the sample with higher density. To investigate further, transport measurements were performed in large van der Pauw samples having identical heterostructures, and as expected they exhibit resistivity that is monotonic with temperature. Finally, we discuss the results in terms of various lengthscales leading to ballistic and hydrodynamic electronic transport, as well as a possible Gurzhi effect.

Theoretical hardness calculated from crystallo-chemical data for MoS2 and WS2 crystals and nanostructures.

The calculation of the hardness of Mo and W disulfides using a crystallo-chemical model provides a unique opportunity to obtain separate quantitative information on the maximum hardness H(max) governed by strong intra-layer covalent bonds acting within the (0001) plane versus the minimum hardness H(min) governed by weak inter-layer van der Waals bonds acting along the c-axis of the hexagonal lattice. The penetration hardness derived from fundamental crystallo-chemical data (confirmed by experimental determinations) proved to be far lower in MS(2) (M = Mo, W) than in graphite and hexagonal BN, both for H(max) (H(graph)/H(MoS2) = 3.85; H(graph)/H(WS2) = 3.60; H(hBN)/H(MoS2) = 2.54; H(hBN)/H(WS2) = 2.37) as well as for H(min) (H(graph)/H(MoS2) = 6.22; H(graph)/H(WS2) = 5.87; H(hBN)/H(MoS2) = 4.72; H(hBN)/H(WS2) = 4.46). However, the gap between H(max) and H(min) is considerably larger in MS(2) (M = Mo,W), as indicated by H(max)/H(min) being 279 in 2H-MoS(2), 282 in 2H-WS(2), 173 in graphite and 150 in hBN. The gap was found to be even larger in MS(2) (M = Mo, W) nanostructures. These findings help to explain the excellent properties of MS(2) (M = Mo, W) as solid lubricants in high tech fields, either as bulk 2H crystals (inter-layer shear and peeling off lubricating mechanisms), or especially as onion-like fullerene nanoparticles (rolling/sliding mechanisms).

Arsenic trioxide sensitizes cancer stem cells to chemoradiotherapy. A new approach in the treatment of inoperable glioblastoma multiforme.

PURPOSE: glioblastoma multiforme (GBM) still bears a very dismal prognosis even with complete resection followed by adjuvant chemoradiation. The aim of the current study was to evaluate in vitro the antitumor efficacy of arsenic trioxide (ATO) in combination with ionizing radiation plus temozolomide and bevacizumab against cultured glioblastoma stem-like cells, as possible way to increase the therapeutic index in patients diagnosed with recurrent, therapy-refractory GBM. METHODS: stem-like tumor cells isolated from a GBM biopsy were established by cell proliferation assays and upregulation of stem cell markers, as proven by reverse transcription - polymerase chain reaction (RT-PCR). Low concentrations of ATO were added prior to temozolomide, bevacizumab and ionizing irradiation. RESULTS: molecular analysis showed that cells expressed CXCR4, Oct-3/4 and GAPDH when compared to placental mesenchymal stem cells, as well as nestin, GFAP and neurofilament protein. Low concentrations of ATO led to morphologic differentiation, with fewer stem cells in Go state and differentiation-associated cytochemical features, like increased sensitivity to cytostatic drugs and radiotherapy. CONCLUSION: ATO exposure before conventional postoperative chemoradiotherapy for GBM might increase treatment efficacy. Further in vivo experiments on laboratory animals and analysis of absorption rate and side effects are required.

Functional and molecular characterization of glioblastoma multiforme-derived cancer stem cells.

PURPOSE: Brain tumors are the leading cause of cancer mortality in children and remain incurable despite advances in surgery and adjuvant therapies. The failure of malignant gliomas to respond to conventional treatment reflects the unique biology of these tumors, linked to a small population of stem-like precursors. This study describes the characteristics of stem cells isolated from glioblastoma multiforme (GM) and gives insight into the mechanism of brain tumorigenesis. METHODS: Tumor stem-like precursors were identified from primary human GM-derived cell culture using immunocytochemistry and reverse transcription polymerase chain reaction (RT-PCR). Cells were cultured in vitro in stem cell medium supplemented with growth factors and then the capacity of the surviving stem-like precursors to form tumor spheres and to continue to proliferate after chemoradiotherapy were tested. RESULTS: The tumor cells expressed the cellular markers CD133, CD105, CD90, Nanog, Oct 3/4, CXCR4, nestin, glial fibrillary acidic protein (GFAP), neurofilament protein (NF) and human glyceraldehyde 3-phosphate dehydrogenase (GAPDH). Cells also displayed a high proliferative potential despite chemotherapy and irradiation and also had the ability to form spheroids in suspension. CONCLUSION: High grade gliomas contain stem-like precursors, which exhibit neural stem cell properties with tumorigenicity, establishing a novel developmental paradigm in the study of brain carcinogenesis and providing a powerful tool to develop patient-tailored therapy for this devastating disease.

Sialocyst of the Parotid Gland in a Child.

Non-neoplastic cysts localized in salivary glands are quite rare and represent approximately 2-5% of all salivary gland lesions. Salivary duct cyst, also known as sialocyst is a true cyst with the epithelium lining the inner side of its walls. It is generally observed in minor salivary glands and it rarely involves the parotid. Patients are mostly affected between the ages of 30 and 40 and the lesion is rarely seen in children. The current case is a rare report, as the patient was a child. The diagnosis has been difficult to ascertain due to the presence of pain, symptom characteristic for inflammatory lesions.

Preoperative Neutrophil-Lymphocyte Ratio, Platelet-Lymphocyte Ratio and Lymphocyte-Monocyte Ratio in Peripheral Blood of Patients with Gastrointestinal Malignant Lesions.

Local inflammation plays a very important role in the apparition and development of tumors and metastasis. The objective of this study was to investigate the significance of neutrophil to lymphocyte ratio (NLR), lymphocyte to monocyte ratio (LMR) and platelet to lymphocyte ratio (PLR) in peripheral blood of patients with gastrointestinal malignant tumors. METHODS: Medical records of 145 patients diagnosed with gastrointestinal malignant tumor between January 2017 and December 2017 were analyzed retrospectively. Pretreatment neutrophil, lymphocyte, platelet and monocyte counts and NLR, LMR and PLR were investigated. RESULTS: The mean for NLR, PLR and LMR in patients with gastrointestinal cancer were determined. CONCLUSIONS: Determination of NLR, PLR and LMR can be easily done with a simple blood test and may be useful inflammatory markers as in our study we have observed the presence of increased inflammatory response in patients with gastrointestinal cancer.

Balthazar Score and Neutrophil-Lymphocytes Ratio in Acute Pancreatitis.

Acute pancreatitis is a pathological entity that poses numerous diagnostic and treatment problems. Severe form is a real challenge for a physician because it has multiple obscure causes, as well as a complex pathophysiology. Thus, the diagnosis is difficult and the choice of the right time for surgical treatment is controversial, the treatment being more frequently nonspecific, supportive for the various affected systems and organs. On a group of 337 patients, laboratory and imaging investigations were performed to diagnose and determine the severity score of acute pancreatitis and the correlation level between the neutrophil-lymphocytes ratio values and the Balthazar score, as a valid assessment method for local and systemic inflammatory changes. The distribution's study of acute pancreatitis by gender according to etiology confirms the predominance of the acute ethanolic pancreatitis in male, but also the higher proportion (54%) of male pancreatitis (181 man vs. 156 women) with gender ratio male/female 1.16/1. The neutrophil-lymphocytes ratio mean value varied according with the Balthazar severity score, that got higher as acute pancreatitis got more advanced and with a certain cut-off value can be considered a simple indicator to determine the severity of acute pancreatitis.

Mesostructured silica and aluminosilicate carriers for oxytetracycline delivery systems.

Oxytetracycline delivery systems containing various MCM-type silica and aluminosilicate with different antibiotic content were developed in order to establish the influence of the support structural and textural properties and aluminum content on the drug release profile. The antibiotic molecules were loaded into the support mesochannels by incipient wetness impregnation method using a drug concentrated aqueous solution. The carriers and drug-loaded materials were investigated by small- and wide-angle XRD, FTIR spectroscopy, TEM and N2 adsorption-desorption isotherms. Faster release kinetics of oxytetracycline from uncalcined silica and aluminosilicate supports was observed, whereas higher drug content led to lower delivery rate. The presence of aluminum into the silica network also slowed down the release rate. The antimicrobial assays performed on Staphylococcus aureus clinical isolates showed that the oxytetracycline-loaded materials containing MCM-41-type mesoporous silica or aluminosilicate carriers inhibited the bacterial development.

Reversal by vasotocin of pinealectomy and constant light effects on the pituitary melanocyte-stimulating hormone (MSH) content in the mouse.

A single injection of 1 pg synthetic arginine vasotocin (AVT) into the third ventricle of the mouse completely prevented the pituitary MSH increase which occurs seven days after pinealectomy or 24 h after exposure to constant light. The same concentration of AVT injected into the third ventricle of normal mice markedly decreased the pituitary MSH content at 20 min following the injection. The present results suggest that AVT injected into the third ventricle of the mouse inhibits synthesis and/or release of MSH-release inhibiting factor (MIF).

Vasotocin, melatonin and narcolepsy: possible involvement of the pineal gland in its patho-physiological mechanism.

Both the pineal nonapeptide hormone arginine vasotocin (AVT) (2.5 micrograms) administered intra-nasally and the pineal indole melatonin (50 mg) administered intravenously to three male narcoleptics (two with auxiliary symptoms and one with sleep attacks only), dramatically increased the amount of REM sleep and decreased REM sleep latency. The duration of the sleep onset REM periods in the two narcoleptics with auxiliary symptoms increased by more than 100 percent after AVT and melatonin administration. In the narcoleptic with sleep attacks only both AVT and melatonin induced REM periods at sleep onset. The hypothesis is advanced that narcolepsy represents an impairment of the melatonin-AVT control in the induction and circadian organization of REM sleep associated with an immaturity of REM triggering centers.

REM sleep induction in prepubertal boys by vasotocin: evidence for the involvement of serotonin containing neurons.

The pineal nonapeptide hormone arginine vasotocin (AVT) (100 ng/kg) administered intra-nasally (IN) to healthy prepubertal boys, dramatically increased the amount of REM sleep, decreased REM sleep latency, and induced REM periods at sleep onset. Neither arginine vasopressin (AVP) nor oxytocin administered IN at the dose of 100 ng/kg was able to reproduce the effects of AVT, demonstrating its high specificity. Methergoline, a selective central 5-hydroxytryptamine (5-HT) receptor blocker, administered IN at the dose of 100 ng/kg, completely prevented AVT induction of REM sleep. Fluoxetine, a specific 5-HT uptake inhibitor, administered IN at the dose of 25 microgram/kg, 10 min after AVT, greatly potentiated the effects of AVT in inducing REM periods at sleep onset and in increasing the amount of REM sleep and the percentage of dream reports. It is suggested that AVT induces REM sleep in prepubertal boys by interfering with 5-HT neurotransmission and that the high sensitivity of prepubertal boys to AVT reflects an immaturity of REM triggering centers.

Vasotocin improves intelligence and attention in mentally retarded children.

In mentally retarded (MR) prepubertal children, investigated both before and after six months of treatment, synthetic arginine vasotocin (AVT) (10(-6) mg/day/0.1 ml, intranasally), but not oxytocin or saline alone, significantly increased the intelligence quotient (IQ) and improved the attention parameters without affecting the short-term memory. Taking into account both the psychometric results and the clinical observations, the effects of AVT could be mainly explained by assuming the improvement of attention. Since there was a significant inverse correlation between the pretreatment levels of the IQ and attention scores and their increase after AVT, and since the AVT effects tend to be more intense in autistic children, we hypothesize that the more affected the attention mechanisms, the more they are sensitive to AVT. The present results are tentatively explained by the paradoxical sleep-enhancing properties of AVT, mechanisms by which AVT could improve the brain plasticity in MR subjects and by this, the attention performance.

Magnesium and calcium concentration in the abdominal aorta of patients deceased by ischemic heart disease.

Magnesium (Mg) and calcium (Ca) concentrations were determined in the abdominal aorta of 28 patients who died by acute myocardial infarction (AMI), of 52 by ischemic heart disease (IHD) and of 26 subjects deceased by accidents or from causes other than atherosclerosis. Mg concentration in the fibrous and calcareous plaques, was significantly lower than in controls. The lowest Mg values were found in those who died by AMI. Calcium concentration, especially in the calcareous plaques, was enormous as against the controls. The four-seven times decreases of Mg/Ca ratio compared with the controls imply an alteration of the arterial wall cells. Magnesium deficit in the arterial wall probably plays a certain role in this process.

AX.25 amateur packet radio as a possible emergency network.

In modern society more and more medical applications need a reliable data transfer. In emergency situations, such transfer may not be available because parts of the communications infrastructure may be affected. An alternative way could be the use of the amateur radio packet network, which offers almost global coverage. We analyzed its use as an emergency data transfer support, including transport of real-time medical data.

Medical informatics education for "allied" profiles.

Medical informatics education should be adapted for each speciality of "allied professions". In this paper we try to share from our experience with students of several profiles: medicine, dentistry, pharmacy, physio-kineto-therapy, clinical laboratory, dentistry techniques and stomatological prophylaxis.

[Multiple cutaneous cylindromas associated with parotid and submandibular gland cylindromas]. / Cylindromes cutanés multiples associés à des cylindromes des glandes parotide et sous-mandibulaire.

BACKGROUND: Multiple cutaneous cylindromas are uncommonly associated with extracutaneous cylindromas. An association between cutaneous cylindromas and salivary gland cylindromas would probably not be fortuitous. CASE REPORT: A 66-year-old man developed multiple cutaneous cylindromas and cylindromas situated in the parotid and submaxillary gland. Histology was similar for both localizations. DISCUSSION: This association was probably not fortuitous as the histology was similar, other cases have been reported in the literature, and recent complaint concerned the development of multiple cutaneous cylindromas and salivary gland cylindromas. Salivary gland cylindromas should be searched for in patients who develop cutaneous cylindromas as they are more aggressive in nature.

[Clinico-statistical observations on malignant ocular tumors surgically resolved at the Cluj-Napoca Ophthalmological Clinic between 1970 and 1990]. / Consideratii clinico-statistice asupra tumorilor maligne oculare rezolvate chirurgicale în Clinica oftalmologica din Cluj-Napoca între anii 1970-1990.

During the period mentioned above there ware hospitalized 54 patients having epibulbar tumours. The anatomopathological exam which was effectuated for 33 patients hes shown Bowen's disease for 14 cases, spinocellular carcinoma for 15 patients and basocellular for 3 patients. There were 4 cases for epibulbar precancerous. There was retinoblastoma for 19 cases; it had been practiced the enucleation of ocular globe for 17 patients and for two cases it had been practiced the exenteration of the eye socket. At the same period there were 91 uveal melanosis 6 of which having iridial localization, 10 cases of ciliary body [correction of cylar corpus], 75 cases of choroid. The hepatic scintigraphy was practiced for 56 patients and had shown for 8 cases hepatic metastasis. The histopathological exam of the melanomata of ciliary and choroidal corpus had shown type A fusiform cells for 22 cases, type B for 43 cases, epithelioid cells for 6 cases and mixed type cells for 13 cases. The hepatic metastasis were epithelioid cells for all the cases and, for 2 cases there were with mixed type cells, It is necessary an active discovering of intraocular and episcleral malign tumours, for increasing the chance of an earlier diagnosis during a stadium that would be able to be treated as conservator as possible be.