Conditions for biphasic competition curves in radioligand binding for ligands subjected to metabolic transformation

The conditions affording biphasic competition curves in radioligand binding for ligands subjected to metabolic transformation was analyzed theoretically. It was shown that when a competing ligand was subjected to transformation to a ligand that showed higher affinity than the parent compound, biphasic competition curves, which might wrongly be interpreted as indicating the presence of two receptor sites, could be observed in binding assays containing a homogenous receptor population. Biphasic competition curves were seen if the conversion of the competitor occurred according to zero and second order kinetics, as well as by enzymatic catalytic processes. However, when the conversion occurred according to a first order kinetics, the competition curves were uniphasic and resolved only into one-site fits, with the apparent affinity of the competitor reflecting the degree of conversion of the competitor to its metabolite. When the metabolic conversion resulted in a metabolite that showed lower affinity for the receptor than the parent compound, the competition curves became supersteep for conversions according to zero and second order kinetics, as well as for conversion by enzymatic catalytic processes.     

The dos and don'ts of an oral mucosal biopsy performed by the general dentist

The recognition of a pathologic entity is only the first step in the chain of events which must be performed for accurate diagnoses and appropriate patient management. Other steps include selection of the type of biopsy to be performed; proper biopsy technique, instrumentation and specimen handling; appropriate fixation; detailed documentation; and postoperative patient instructions. If the clinician performs each step carefully and correctly, the patient is ensured of receiving an accurate diagnosis in the shortest possible period of time.     

Induction of antibodies against epitopes inaccessible on the HIV type 1 envelope oligomer by immunization with recombinant monomeric glycoprotein 120

An N-glycan (N306) at the base of the V3 loop of HIV-BRU gp120 is shielding a linear neutralization epitope at the tip of the V3 loop on oligomeric Env. In contrast, this epitope is readily antigenic on monomeric gp120. Immunization with recombinant monomeric HIV-BRU gp120 may thus be expected to elicit antibodies preferentially neutralizing mutant variants of HIV-BRU lacking the N306 glycan. Therefore, two guinea pigs were immunized with monomeric wild-type HIV-BRU gp120 possessing the N306 glycan and immune sera were tested for neutralization against target viruses HIV-BRU, -A308, and -A308T321. HIV-A308 and HIV-A308T321 lack the N306 glycan; HIV-A308T321 contains an additional mutation at the tip of V3 rendering it resistant to MAb binding at this epitope. Both immune sera preferentially neutralized the two mutant virus variants lacking the N306 glycan, with a 10- to 20-fold increase in neutralization titer compared with the wild-type HIV-BRU. Thus, immunization with monomeric HIV-BRU gp120 elicited antibodies preferentially neutralizing HIV variants lacking the N306 glycan. In addition to antibodies directed against the tip of V3, other antibodies directed against epitopes shielded by the N306 glycan on the envelope oligomer were elicited by the immunization, as demonstrated by the ability of the immune sera to neutralize HIV-A308T321. One such epitope was overlapping the NEA-9284 epitope located at the amino-terminal flank of the V3 loop. Our results demonstrate that monomeric gp120 contains immunogenic structures inaccessible on the envelope oligomer. The limited ability of recombinant gp120 vaccines to induce neutralizing antibodies against primary isolates may thus not exclusively reflect genetic variation.     

Characterization of microsatellite loci in a pelagic spawner: the bluehead wrasse, Thalassoma bifasciatum

Securing informed consent, though vital to any defense, will not shield a practitioner from a malpractice claim. That is because courts generally hold that patients cannot consent to negligent treatment.     

Quantification of eumelanin and pheomelanin: stereologic image analysis method

Chemical antioxidants and catalase have been shown to be ineffective in improving the motility of ram spermatozoa in a chemically-defined diluent (RSD-1). In an attempt to identify the biochemical basis of this observation, the activity of aromatic amino acid oxidase (AAAO), the enzyme responsible for generation of hydrogen peroxide in ram and bull spermatozoa, has been investigated. Ram spermatozoa contained higher levels of AAAO activity than bull spermatozoa, although the physico-chemical properties of the enzyme were generally similar in both species. Components of the medium had a marked effect upon AAAO activity. In the presence of glutamate and 3-(N-morpholino)propanesulfonic acid (MOPS), AAAO activity was decreased. Pyruvate appeared to increase AAAO activity. This was due to the ability of this substance to destroy hydrogen peroxide. Pyruvate in RSD-1 works as an effective antioxidant and therefore eliminates the need for other antioxidants in the semen diluent.     

Effects of nadolol on hemodynamic and hemostatic responses to potential mental and physical triggers of myocardial infarction in subjects with mild systemic hypertension

Exposition of results and complications in 7,162 consecutive sessions with Shockwave Extracorporeal Lithotripsy (SWEL) applied to 3,950 lithiasis located at all levels of the urinary tract. These procedures have been performed without sedation or anaesthesia. Diuresis was not forced during or after treatment with serotherapy, mannitol, or diuretics. Treatment was conducted in an outpatients clinic in all cases. The treatment/lithiasis ratio in this initial series was 1.7. Following therapy, 7.09% of patients treated attended the emergency unit due to colic pain/fever. 3.60% of patients treated required hospitalization due to major complications: subcapsular-retroperitoneal haematoma, 9 cases; ureteral obstruction, 120 cases; septicemia, 22 cases; renal function annulment, 11 cases and death, 2 cases.     

Camelina (Camelina sativa L.) oil as a biofuels feedstock: Golden opportunity or false hope?

Camelina (Camelina sativa L.) is a promising sustainable alternative energy crop belonging to the Brassicaceae (mustard) family. Camelina has several favorable agronomic characteristics which give it potential to significantly enhance domestic biofuels production. With high seed oil content as well as high yield of oil per hectare, camelina can be efficiently processed into high quality renewable fuels such as biodiesel (fatty acid methyl esters) as well as renewable diesel and jet fuels using existing technologies. This review summarizes the attributes of camelina along with conversion of the lipid fraction into advanced renewable biofuels.     

Modification of para-sexiphenyl layer growth by UV induced polarity changes of polymeric substrates

We report on the deposition of para-sexiphenyl (PSP) on poly(diphenyl bicyclo[2.2.1]hept-5-ene-2,3-dicarboxylate) (PPNB) by hot wall epitaxy (HWE). The surface polarity of the substrate, PPNB, can be increased by UV-illumination via a photo-Fries rearrangement. The influence of the changed surface polarity on the surface morphology and the structure of the PSP layers were studied by atomic force microscopy (AFM), X-ray diffraction (XRD) and grazing incidence X-ray diffraction (GIXD). The observation of growth spirals and islands, providing mono-layer step heights of standing PSP molecules, underline a high crystallographic order of the films which is confirmed by XRD analysis. GIXD experiments show a strong preferential (0 0 1) orientation of the PSP layers with better alignment on substrates with smaller surface polarity. The γ- and Baker-crystal structures are present in the films grown at low substrate temperatures, but only Baker structure was found in the films deposited at high substrate temperatures. However the main influence on the growth of PSP, is caused by the polarity change induced by pre-treating the PPNB substrate by UV-illumination.     

Comparative Oxidative Stability of Fatty Acid Alkyl Esters by Accelerated Methods

Several fatty acid alkyl esters were subjected to accelerated methods of oxidation, including EN 14112 (Rancimat method) and pressurized differential scanning calorimetry (PDSC). Structural trends elucidated from both methods that improved oxidative stability included decreasing the number of double bonds, introduction of trans as opposed to cis unsaturation, location of unsaturation closer to the ester head group, and elimination of hydroxyl groups. Also noticed with EN 14112 was an improvement in oxidative stability when a larger ester head group was utilized. Methyl esters that contained ten or less carbons in the fatty acid backbone were unacceptable for analysis at 110 °C (EN 14112) due to excessive sample evaporation. With respect to PDSC, a correlation was noticed in which the oxidation onset temperature (OT) of saturated fatty esters increased with decreasing molecular weight (R ² 0.7328). In the case of the monounsaturates, a very strong inverse correlation was detected between molecular weight and OT (R ² 0.9988), which was in agreement with EN 14112. Lastly, a strong direct correlation (R ² 0.8759) was elucidated between OT and oil stability index (OSI, EN 14112, 80 °C). The correlation was not as strong (R ² 0.5852) between OSI obtained at 110 °C and OT. Disclaimer: Product names are necessary to report factually on available data; however, the USDA neither guarantees nor warrants the standard of the product, and the use of the name by USDA implies no approval of the product to the exclusion of others that may also be suitable.