The in vitro pharmacological profile of KR31080, a nonpeptide AT1 receptor antagonist

Summary— KR31080 (2-butyl-5-methyl-6-(1-oxopyridin-2-yl)-3-[[2'-(1H-tetrazol-5-yl) biphenyl-4-yl]methyl]-3H-imidazo[4,5-b] pyridine) is a potent inhibitor of angiotensin type 1 (AT₁) receptors in rabbit aorta and human recombinant AT₁ receptors. In the isolated rabbit thoracic aorta, KR31080 caused a nonparallel shift to the right of the concentration-response curves to angiotensin II (All) with decreased maximal response (pD'₂ = 10.1 ± 0.1), but had no effect on the contractile response induced by norepinephrine. KR31080 inhibited specific [¹²⁵I]AII binding to rabbit aortic membranes (AT, receptors) and [¹²⁵I][Sar¹, Ile⁸]AII binding to human recombinant AT₁ receptors in a concentration-dependent manner with IC₅₀ values of 0.84 ± 0.08 nM and 1.92 ± 0.15 nM, respectively, but did not inhibit specific [¹²⁵I)AII binding to bovine cerebellum membranes (ÀT₂ receptors). In the Scatchard analysis, KR31080 interacted with rabbit aortic AT₁ receptors in a competitive manner, similar to losartan. These results demonstrate that KR31080 is a potent and AT₁ selective angiotensin receptor antagonist which exerts a competitive antagonism in the [¹²⁵I]AII binding assay and insurmountable AT₁ receptor antagonism in the functional study.     

LIPOPROTEIN(α) IN HEALTH AND DISEASE

SUMMARY Elevated plasma levels of Lp(a) do seem to influence the progression of atherosclerosis. Evidence is emerging that certain apo(a) isoforms may be more atherogenic than others, and in transgenic mice free apo(a) has been shown to be associated with accelerated atherosclerosis. Currently it is not known whether treating elevated Lp(a) levels will reduce progression of atherosclerosis and, as therapeutic options are limited, mass screening of Lp(a) levels in populations is not indicated. The presence of raised Lp(a) levels, however, warrants aggressive treatment to reduce other cardiovascular risk factors. Continuing research to investigate the relationship of the apo(a) gene to other genes, including the plasminogen gene and apo(a)-related genes, will add further information pertaining to the evolution, function, regulation and clinical implications of Lp(a).     

β-Glucuronidase activation of latent aggression-promoting cues in mouse bladder urine

The present study was designed to investigate the chemical properties of the aggression-promoting cues present in bladder urine of male mice. The results of the first experiment confirmed earlier work by demonstrating the presence of an aggression-promoting chemosignal in bladder urine. In Experiment 2, behavioral assays were separately performed on the organic and aqueous layers of bladder urine obtained by repeated dichloromethane extractions. Only the combined organic layers of the initial three extractions demonstrated behavioral activity. A fourth extraction showed no behavioral activity for both organic and aqueous layers. However, the findings of Experiment 3 showed that incubation of the aqueous layer from the third CH₂Cl₂ extraction in β-glucuronidase can free additional aggression-promoting cues into a subsequent CH₂Cl₂ extraction. It is concluded that two forms of the aggression-promoting chemosignal are present in bladder urine. One is lipophilic and behaviorally active, whereas the other is conjugated, possessing latent chemosignal properties.     

Detection of chromosomes and estimation of aneuploidy in human spermatozoa using fluorescence in-situ hybridization

The development and application of fluorescence in-situ hybridization (FISH) has opened the way for comprehensive studies on numerical chromosome abnormalities in human spermatozoa. FISH can be rapidly applied to large numbers of spermatozoa and thus overcomes the major limitation of karyotyping spermatozoa after penetration of zona-free hamster oocytes. The simultaneous hybridization of two or more chromosome-specific probes to spermatozoa and subsequent detection of the bound probes using different fluorescent detection systems enables two or more chromosomes to be localized simultaneously in the same spermatozoon and provides a technique for undertaking reasonable estimates of aneuploidy. The most commonly used probes are those which bind to the centromeric region of specific chromosomes. Most studies to date have concentrated on estimating aneuploidy in spermatozoa from normospermic men, although reports are beginning to appear on aneuploidy in spermatozoa from subfertile and infertile men. Multi- probe FISH studies have generally reported disomy (hyperhaploidy) estimates of 0.05-0.2% per chromosome. There is preliminary evidence that some chromosomes such as X, Y and 21 are predisposed towards higher rates of non-disjunction during spermatogenesis. There are also suggestions of inter-donor variability in aneuploidy frequencies for specific chromosomes, although this requires confirmation in larger studies. While FISH is clearly a powerful technique that has many applications in reproductive medicine, it must also be realized that it does have limitations and the technology itself is still evolving and has yet to be fully validated on spermatozoa.      

The impact of testing accommodations on MCAT scores: descriptive results.

PURPOSE: Medical College Admission Test (MCAT) examinees with disabilities who receive accommodations receive flagged scores indicating nonstandard administration. This report compares MCAT examinees who received accommodations and their performances with standard examinees. METHOD: Aggregate history records of all 1994-2000 MCAT examinees were identified as flagged (2,401) or standard (297,880), then further sorted by race/ethnicity (broadly identified as underrepresented minority and non-URM, at the time of testing) and gender. Those with flagged scores were also classified by disability (LD = learning disability, ADHD = attention deficit hyperactivity disorder, LD/ADHD = learning disability and attention deficit hyperactivity disorder, and Other = other disability) and type of accommodation. Mean MCAT scores were calculated for all groups. A group of 866 examinees took the MCAT first as a standard administration and subsequently with accommodations. In a separate analysis, their two sets of scores were compared. RESULTS: Less than 1% of examinees (2,401) had accommodations; of these, 55% were LD, 17% ADHD, 5% LD/ADHD, and 23% Other. Extended time was the most frequently provided accommodation. Mean flagged scores slightly exceeded mean standard scores on all MCAT sections. Examinees who retook the MCAT with accommodations after a standard administration increased their scores by six points, quadrupling the average gain Standard-Standard retest cohort from another study. CONCLUSION: The small but statistically significant different higher flagged scores may reflect either appropriate compensation or overly generous accommodations. Extended time had a positive impact on the scores of those who retested with this accommodation. The validity the flagged MCAT in predicting success in medical school is not known, and further investigation is underway.     

Sequencing of the alpha-synuclein gene in a large series of cases of familial Parkinson's disease fails to reveal any further mutations. The European Consortium on Genetic Susceptibility in Parkinson's Disease (GSPD)

A mutation in exon 4 of the human alpha-synuclein gene was reported recently in four families with autosomal dominant Parkinson's disease (PD). In order to examine whether mutations in this exon or elsewhere in the gene are common in familial PD, all seven exons of the alpha- synuclein gene were amplified by PCR from index cases of 30 European and American Caucasian kindreds affected with autosomal dominant PD. Each product was sequenced directly and examined for mutations in the open reading frame. No mutations were found in any of the samples examined. We conclude that the A53T change described in the alpha- synuclein gene is a rare cause of PD or may even be a rare variant. Mutations in the regulatory or intronic regions of the gene were not excluded by this study.      

Preliminary observations on polar body extrusion and pronuclear formation in human oocytes using time-lapse video cinematography

In this study, we have used time-lapse video cinematography to study fertilization in 50 human oocytes that had undergone intracytoplasmic sperm injection (ICSI). Time-lapse recording commenced shortly after ICSI and proceeded for 17-20 h. Oocytes were cultured in an environmental chamber which was maintained under standard culture conditions. Overall, 38 oocytes (76%) were fertilized normally, and the fertilization rate and embryo quality were not significantly different from 487 sibling oocytes cultured in a conventional incubator. Normal fertilization followed a defined course of events, although the timing of these events varied markedly between oocytes. In 35 of the 38 fertilized oocytes (92%), there were circular waves of granulation within the ooplasm which had a periodicity of 20-53 min. The sperm head decondensed during this granulation phase. The second polar body was then extruded, and this was followed by the central formation of the male pronucleus. The female pronucleus formed in the cytoplasm adjacent to the second polar body at the same time as, or slightly after, the male pronucleus, and was subsequently drawn towards the male pronucleus until the two abutted. Both pronuclei then increased in size, the nucleoli moved around within the pronuclei and some nucleoli coalesced. During pronuclear growth, the organelles contracted from the cortex towards the centre of the oocyte, leaving a clear cortical zone. The oocyte decreased in diameter from 112 to 106 microm (P < 0.0001) during the course of the observation period. The female pronucleus was significantly smaller in diameter than the male pronucleus (24.1 and 22.4 microm respectively, P = 0.008) and contained fewer nucleoli (4.2 and 7.0 respectively, P < 0.0001). After time-lapse recording, oocytes were cultured for 48 h prior to embryo transfer or cryopreservation. Embryo quality was related to fertilization events and periodicity of the cytoplasmic wave, and it was found that good quality embryos arose from oocytes that had more uniform timing from injection to pronuclear abuttal and tended to have a longer cytoplasmic wave. In conclusion, we have shown that time-lapse video cinematography is an excellent tool for studying fertilization and early embryo development, and have demonstrated that human fertilization comprises numerous complex dynamic events.      

Overview and update on molecular testing in non-small cell lung carcinoma utilizing endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) samples

Lung carcinoma remains one of the most frequent and aggressive human neoplasms. Fortunately, in the last decades, the increasing knowledge of the molecular mechanisms leading to cancer development has allowed the use of targeted therapies with improvement of prognosis in many patients. Clinical management has also changed after the introduction of endobronchialultrasonographic bronchoscopy that allows a conservative staging of lung tumors, avoiding the need of mediastinoscopy for lymph node staging. Lung pathologists and cytopathologists are facing the challenge of giving the more comprehensive prognostic and predictive information with ever smaller tissue or cytological samples. The aim of this review is to summarize the molecular testing for non-small cell lung carcinoma and how pathologists can contribute to the patient's outcome with a conscious management of biological samples.     

Agility following the application of cold therapy

Cold application is commonly used before strenuous exercise due to its hypalgesic effects. Some have questioned this procedure because of reports that cold may reduce isokinetic torque. However, there have been no investigations of actual physical performance following cold application. The purpose of this study was to determine if a 20-minute ice immersion treatment to the foot and ankle affected the performance of three agility tests: the carioca maneuver, the cocontraction test, and the shuttle run. Twenty-four male athletic subjects were tested during two different treatment sessions following an orientation session. Subjects were tested following a 20-minute 1°C ice immersion treatment to the dominant foot and ankle and 20 minutes of rest. Following each treatment, subjects performed three trials of each agility test, with 30 seconds rest between each trial, and 1 minute between each different agility test. The order in which each subject performed the agility tests was determined by a balanced Latin square. A MANOVA with repeated measures was used to determine if there was an overall significant difference in the agility times recorded between the cold and control treatments and if the order of the treatment sessions affected the scores. Although the mean agility time scores were slightly slower following the cold treatment, cooling the foot and ankle caused no difference in agility times. Also, there was no difference resulting from the treatment orders. We felt that the slightly slower scores may have been a result of tissue stiffness and/or subject's apprehension immediately following the cold treatment. Cold application to the foot and ankle can be used before strenuous exercise without altering agility.