Assessment of D-glucose transport kinetics in the perfused human placenta: An in vitro study

Abstract Background : There have been no reports to date on glucose transport kinetics and the effect of graded hyperglycemia in the human placenta in non-steady-state conditions.
Methods : The transport kinetics of D-glucose in the human placenta was investigated in non-steady state conditions in vitro using perfusion of isolated placental lobules. National Cancer Tissue Culture (NCTC) 135 culture medium, diluted with Earle's buffered salt solution was used as the perfusate. ¹⁴C-Labeled D-glucose and water as reference were injected as a single bolus into the maternal arterial perfusate. Perfusate samples were collected and analyzed from the maternal and fetal venous outflows.
Results : In four successful perfusions, differential transport rates of glucose in the maternal-fetal direction averaged 1.03, 1.02, 1.09, 1.04 and 1.03 times those of corresponding tritiated water transport rates for 10, 25, 50, 75 and 90% of efflux fractions, respectively. Glucose transport fraction, expressed as percentage of injected maternal dose averaged 84 ± 3.1% of water transport fraction in the four perfusions. Glucose kinetic parameters expressed as area under the curve, elimination constant (Kel), clearance, time for maximum response, absorption rate and elimination rate averaged 0.25, 0.29, 3.96, 1.02, 0.25 and 0.18 times that of the corresponding tritiated water value, respectively. Neither the different kinetic parameters nor the transport fraction indices differed significantly when glucose concentrations in the same perfusions were raised successively from 5.56 to 27.80 and then to 55.6 mmol/L.
Conclusions : We speculate that within physiological limits, hyperglycemia per se plays no significant part in altering glucose transport kinetics across the human placenta in the maternal-fetal direction.     

Flow-injection chemiluminescent determination of cefprozil using Tris (2,2'-bipyridyl) ruthenium (II)-permanganate system

A rapid and sensitive chemiluminescence (CL) method using flow-injection (FI) has been developed for the determination of a second generation cephalosporin, cefprozil. The method is based on the CL reaction of cefprozil with acidic potassium permanganate and tris (2,2'-bipyridyl) ruthenium (II), Ru (bipy)3(2+). The CL intensity is greatly enhanced when quinine sulfate is used as a sensitizer. After optimization of the different experimental parameters, a calibration graph was obtained over a concentration range of 0.1-3.0 microg ml(-1) with minimum detectability of 0.005 microgml(-1) (S/N=3). The correlation coefficient was 0.9998 (n=6) with a relative standard deviation (%R.S.D.) of 1.63% for 2.0 microgml(-1). The proposed method was successfully applied to commercial tablets. The average percentage recovery (n=6) was 99.9+/-1.40.     

Electron microscopic investigation of hyaline bodies in odontogenic cysts

Abstract With the light microscope, hyaline bodies of Rushton may appear lamellar or granular. In s investigation, the ultrastructures of both lamellar and granular forms were studied in formalin fixed material, and in specimens fixed in osmium tetroxide. The lamellar type was composed of alternating electron dense and electron lucent layers, the outermost layer always being electron dense. The granular type was composed of amorphous material in which fragments of red blood cells could be Seen. Some hyaline bodies were partly granular and partly lamellar. The surfaces of the epithelial s apposed to both types showed large numbers of hemidesmosomes, but no basal lamina was seen, ne amorphous material in the granular hyaline bodies appeared very similar to the substance of the generating red blood cells, and extravasated red cells were commonly found in the adjacent connective tissue. The results suggest that the granular type is formed from degenerating red blood cells, and that the lamellar pattern may result from segregation of components within the mass rather an by an incremental form of growth. No support was found for the hypotheses that hyaline bodies e keratinous or a secretory product of the epithelial cells.     

Brugada syndrome and fever: genetic and molecular characterization of patients carrying SCN5A mutations

OBJECTIVE: Brugada syndrome (BrS) is characterized by ventricular tachyarrhythmias leading to sudden cardiac death and is caused, in part, by mutations in the SCN5A gene encoding the sodium channel Na(v)1.5. Fever can trigger or exacerbate the clinical manifestations of BrS. The aim of this work was to characterize the genetic and molecular determinants of fever-dependent BrS. METHODS: Four male patients with typical BrS ST-segment elevation in V1-V3 or ventricular arrhythmias during fever were screened for mutations in the SCN5A gene. Wild-type (WT) and mutant Na(v)1.5 channels were expressed in HEK293 cells. The sodium currents (I(Na)) were analysed using the whole-cell patch clamp technique at various temperatures. Protein expression of WT and mutant channels was studied by Western blot experiments. RESULTS: Two mutations in SCN5A, L325R and R535X, were identified. Expression of the two mutant Na(v)1.5 channels in HEK293 cells revealed in each case a severe loss-of-function. Upon the increase of temperature up to 42 degrees C, we observed a pronounced acceleration of Na(v)1.5 activation and fast inactivation kinetics. Cardiac action potential modelling experiments suggest that in patients with reduced I(Na), fever could prematurely shorten the action potential by virtue of its effect on WT channels. Further experiments revealed that L325R channels are likely misfolded, since their function could be partially rescued by mexiletine or curcumin. In co-expression experiments, L325R channels interfered with the proper function of WT channels, suggesting that a dominant negative phenomenon may underlie BrS triggered by fever. CONCLUSIONS: The genetic background of BrS patients sensitive to fever is heterogeneous. Our experimental data suggest that the clinical manifestations of fever-exacerbated BrS may not be mutation specific.     

Applications of 2-arylhydrazononitriles in synthesis: preparation of new indole containing 1,2,3-triazole, pyrazole and pyrazolo[1,5-a]pyrimidine derivatives and evaluation of their antimicrobial activities

In this effort, 2-arylhdrazononitriles were used as key synthons for the preparation of wide variety of new, uniquely substituted heterocyclic substances. In addition, the results of biological evaluations demonstrate that members of the group prepared have promising antimicrobial activities against Gram negative bacteria, Gram positive bacteria and Yeast. In the synthetic sequences, 3-(1-methyl-1H-indol-3-yl)-3-oxo-2-(phenylhydrazono)propanenitrile 2a and its 2-methyl derivative 2b were found to react with hydroxylamine hydrochloride to yield the corresponding indolyl-5-amino-2-phenyl-1,2,3-triazoles 4a,b. These amines react with cyanoacetic acid in presence of acetic anhydride either thermally or under microwave irradiation conditions to yield the corresponding cyanoacetamides 5a,b, which condensed readily with dimethylformamide dimethylacetal to yield the enaminonitriles 6a,b. Whereas heating of 6a,b with hydrazine hydrate affords compound 8, compound 12 is produced when these reactants are subjected to microwave irradiation. We observed that the aminopyrazole 9 reacts with enaminal 13 to yield 14 and that its reactions with enaminones 15 afford 17. Finally, compound 5 reacts with cinnamaldehyde to yield the corresponding Schiff’s base 18 that does not undergo cyclization to form the pyridine derivative 19. The activities of all new substances synthesized in this investigation were evaluated against a panel of microbial organisms. The results show that 4a, 4b, 5b and 9b display strong antimicrobial activities against all of the tested organisms.     

In vivo MRI for effective non‐invasive detection and follow‐up of an orthotopic mouse model of lung cancer

One of the main reasons for the dismal prognosis of lung cancer is related to the late diagnosis of this pathology. In this study, we evaluated the potential of optimized lung MRI techniques as a completely non‐invasive approach for non‐small‐cell lung cancer (NSCLC) MRI in vivo detection and follow‐up in a mouse model of lung adenocarcinoma expressing the luciferase gene. Bioluminescent lung tumour cells were orthotopically implanted in immuno‐deficient mice. Ultra‐short echo‐time (UTE) MRI free‐breathing acquisitions were compared with standard gradient‐echo lung MRI (FLASH) using both respiratory‐gated and free‐breathing protocols. The MRI findings were validated against bioluminescence imaging (BLI) and gold‐standard histopathology analysis. Adenocarcinoma‐like pathological tissue was successfully identified in all the mice with gated‐FLASH and non‐gated UTE MRI, and good tumour co‐localization was found between MRI, BLI and histological analyses. An excellent or good correlation was found between the measured bioluminescent signal and the total tumour volumes quantified with UTE MRI or gated‐FLASH MRI, respectively. No significant correlation was found when the tumours were segmented on non‐gated MR FLASH images. MRI was shown to be a powerful imaging tool able to detect, quantify and longitudinally monitor the development of sub‐millimetric NSCLCs. To our knowledge, this is the first study which proves the feasibility of a completely non‐invasive MRI quantitative detection of lung adenocarcinoma in freely breathing mice. The absence of ionizing radiation and the high‐resolution of MRI, along with the complete non‐invasiveness and good reproducibility of the proposed non‐gated protocol, make this imaging tool ideal for direct translational applications. Copyright © 2014 John Wiley & Sons, Ltd.