Dielectric properties of the non-glycated and in vitro methylglyoxal-glycated cornea of the rabbit eye.

The dielectric properties of the non-glycated and in vitro methylglyoxal-glycated cornea of the rabbit eye were tested in the frequency range of 200 Hz to 100 kHz of the electric field and at temperatures of 25 to 140 °C. The denaturation temperature (Td) for the non-glycated cornea and the non-enzymatically glycated cornea are approximately 45 and 55 °C, respectively. The mechanism of proton conduction up to Td in a glycated cornea requires more energy, i.e. more than twice the activation energy (ΔH) than in non-glycated tissue. The dielectric spectra for both examined tissues showed the same characteristic frequency of about 7 kHz assigned to the orientation relaxation time of the polar side groups inside the corneal stroma. These results may be useful in the surgical treatment of the cornea using conductive keratoplasty and in tissue engineering for clinical applications to regenerate this tissue. The medical use of these physico-biological techniques is important because the human cornea protects all eye tissues from various environmental factors.

Recent advances in fungal serine protease inhibitors.

Four types of antifungal drugs are available that include inhibitors of ergosterol synthesis, of fungal RNA biosynthesis, and of cell wall biosynthesis as well as physiochemical regulators of fungal membrane sterols. Increasing resistance to antifungal drugs can severely limit treatment options of fungal nail infections, vaginal candidiasis, ringworm, blastomycosis, histoplasmosis, and Candida infections of the mouth, throat, and esophagus, among other infections. Development of strategies focused on new fungicides can effectively help tackle troublesome fungal diseases. The virulence and optimal growth of fungi depend on various extracellular secreted factors, among which proteases, such as serine proteases, are of particular interest. A specific extracellular proteolytic system enables fungi to survive and penetrate the tissues. Given the role of fungal proteases in infection, any molecule capable of selectively and specifically inhibiting their activity can lead to the development of potential drugs. Owing to their specific mode of action, fungal protease inhibitors can avoid fungal resistance observed with currently available treatments. Although fungal secreted proteases have been extensively studied as potential virulence factors, our understanding of the substrate specificity of such proteases remains poor. In this review, we summarize the recent advances in the design and development of specific serine protease inhibitors and provide a brief history of the compounds that inhibit fungal serine protease activity.

Nanomechanical characterization of single phospholipid bilayer in ripple phase with PF-QNM AFM.

Topography and nanomechanical properties of the supported 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC) single bilayer in the ripple phase were investigated by atomic force microscopy with the use of PeakForce Quantitative Nanomechanical Mapping (PF-QNM) mode under liquid conditions. The DMPC single bilayer was deposited on the mica surface by Langmuir-Blodgett and Langmuir-Schaefer techniques combined. Next, the sample was stored overnight at 4 °C under buffer solution (pH = 7.6) in the presence of tris(hydroxymethyl)aminomethane, (Tris), and then, AFM imaging was performed at 21 °C using the same buffer. The AFM topography images revealed the presence of a periodic structure with an average wavelength of 96.0 ± 7.8 nm and an average amplitude of 0.97 ± 0.03 nm. This macro-ripple structure was asymmetric and formed by long ripples composed of two stripes of different heights. The changes in topography were accompanied by local changes in the Young's modulus, which indicate that the nanomechanical properties of the bilayer are not evenly distributed, namely, the higher stripes are characterized by a lower Young's modulus than that calculated for lower stripes of the ripples. This indicates that the ripple phase is composed of phospholipid molecules of periodically changed orientation and conformation characteristic for fluid-like and gel-like state of DMPC.

Trial comparison of mitochondrial cristae craters images obtained by the freeze-fracturing and ultrathin sections method.

In two-folded lamina of the mitochondrial cristae occurs in mitochondria of spermatocytes large areas of the inner and outer halves in freeze-fracturing technique morphological observations suggest that in mitochondrial membrane there exist "crater-like' structures with internal diameter of approximately 18 nm. A question has come up why no mention has so far been found in the literature of the appearance of similar structure in mitochondrial cristae in specimens in transmission electron microscope (TEM) observed. Thus comparison of our findings obtained by the freeze-fracturing (FF) method with those achieved by TEM was made.

[The diagnostic value of anti-CMV and anti-HPV-B19 antiviral antibodies in studies on causes of recurrent abortions]. / Wartosc diagnostyczna przeciwcial przeciwwirusowych anty-CMV i anty-HPV-B19 w dochodzeniu przyczyn nawracajacych poronien.

Presence of serum anti-cytomegalovirus (CMV) and anti-parvovirus B19 (HPV-B19) antibodies was studied in 11 women within the first day after consecutive spontaneous abortion in the second trimester of pregnancy and in the control group, consisting of 15 women in the second trimester of a normal pregnancy. Most of studied women manifested presence of serum IgG class anti-CMV antibodies (IgG-anti-CMV) and levels of the antibodies proved significantly higher in women following spontaneous abortions. The patients frequently demonstrated in parallel presence of serum IgG class anti-HPV-B19 antibodies. In one patient a generalised nonimmunological hydrops fetalis was disclosed and her serum contained IgM and IgG class antibodies against CMV as well as against HPV-B19. The results suggest that in majority of the studied women the spontaneous abortion might have resulted from fetal infection due to reactivation of chronic CMV infection in the course of pregnancy.

Freeze-fracture studies on mitochondrial membranes of spermatocytes.

Separation of the two-folded lamina of the mitochondrial cristae occurs in mitochondria of spermatocytes and spermatids. Freeze-fracture exposes large areas of the inner and outer halves of the inner membrane. The surface of the outer half of the inner membrane is concave, with small numbers of intramembranous particles (IMPs). Its distinctive feature is the presence of protruding particles surrounding a pit. On the inner half of the inner membrane, there are large numbers of densely-packed, irregularly-distributed IMPs, among which regular pits are seen. Morphometric analysis and reconstructions suggest that these structures are "channels" in the mitochondrial membrane with an internal diameter of approximately 18 nm. It is uncertain whether such mitochondrial structures are confined to the spermatocyte or whether they may also occur in other cells.

A goniometrical study of mitochondrial cristae in rat heart muscle and ependyma of the choroid plexus after application 2,4-DNP in vivo.

We have sought a method capable of detecting small changes in mitochondrial cristae thickness under normal and experimental conditions. Using conventional electron microscopy and goniometry, we studied changes in mitochondria of rat heart muscle and of choroid plexus ependyma caused by treatment with 2,4-dinitrophenol (DNP). Calculation of real thickness was made using goniometric data (formula shown) and the results checked by the method of Casley-Smith and Davy. DNP produced a thickness increase of low statistical significance in choroid plexus ependymal mitochondrial cristae, but a decrease for heart muscle cristae. Although our findings do not resolve the problem of DNP-induced cristae changes, our modified goniometric method may be useful for other studies.