The thermodynamic dissociation constants of four non-steroidal anti-inflammatory drugs by the least-squares nonlinear regression of multiwavelength spectrophotometric pH-titration data

The mixed dissociation constants of four non-steroidal anti-inflammatory drugs (NSAIDs) ibuprofen, diclofenac sodium, flurbiprofen and ketoprofen at various ionic strengths I of range 0.003-0.155, and at temperatures of 25 degrees C and 37 degrees C, were determined with the use of two different multiwavelength and multivariate treatments of spectral data, SPECFIT/32 and SQUAD(84) nonlinear regression analyses and INDICES factor analysis. The factor analysis in the INDICES program predicts the correct number of components, and even the presence of minor ones, when the data quality is high and the instrumental error is known. The thermodynamic dissociation constant pK(a)(T) was estimated by nonlinear regression of (pK(a), I) data at 25 degrees C and 37 degrees C. Goodness-of-fit tests for various regression diagnostics enabled the reliability of the parameter estimates found to be proven. PALLAS, MARVIN, SPARC, ACD/pK(a) and Pharma Algorithms predict pK(a) being based on the structural formulae of drug compounds in agreement with the experimental value. The best agreement seems to be between the ACD/pK(a) program and experimentally found values and with SPARC. PALLAS and MARVIN predicted pK(a,pred) values with larger bias errors in comparison with the experimental value for all four drugs.     

What is a "normal" right ventricle?

AIMS: The aim of this project was to define normal values of right ventricular (RV) volumes and ejection fraction (EF) in healthy population using 2D echocardiography. METHODS AND RESULTS: The "patient" group comprised 91 healthy volunteers aged 17-62 years. RV volumetry was based on ellipsoidal shell model method. Left ventricular (LV) volumes were assessed by Teichholz formula. All volumes were indexed per m(2) of BSA and the rate distribution of measured and calculated values were evaluated. The normal range of individual parameters was expressed as mean value+/-2 standard deviations (delta). A pair test was used to compare corresponding results of the RV and LV measurements. The regression analysis was used to test the relationship between LV and RV volumes and age. Indexed enddiastolic and endsystolic RV volumes were 79.1+/-29.9ml and 32.6+/-19.7ml, respectively, EF being 50+/-9.7% in men and 58+/-13.6% in women. No correlation with patient's age was observed. CONCLUSION: Enddiastolic and endsystolic volumes of RV were significantly higher than those of LV. EF of RV was lower as compare to LV. Right ventricular EF in men was lower than that in women. There was no correlation between EF and patient's age.     

CD30 (Ber-H2) expression by thymocytes and thymic epithelial cells during the late first and second trimester of gestation: an immunohistochemical and in situ hybridization (ISH) study.

BACKGROUND: The exact biological function of CD30 in the thymus during development has been only partially elucidated, although data indicate it may be involved in negative selection. This study was prompted by the observation of a positive reaction of thymic epithelial cells (TECs), Hassall's corpuscles, and thymocytes with the monoclonal antibody CD30 during the late first and second trimester. MATERIAL/METHODS: Twenty paraffin-embedded fetal thymus specimens at the late first and second trimester were investigated by conventional histology and immunohistology for CD30 expression. To provide additional information on the nature and localization of CD30+ thymocytes and CD30+ TECs, in situ hybridization (ISH) was performed on the specimens. Results: 1) In the medulla, a statistically significant difference between CD30+ thymocytes from the late first trimester and those from the second trimester (p<0.0001, t-test) was demonstrated. No significant difference was found concerning CD30+ thymocytes in the cortex. 2) Many medullary TECs and Hassall's corpuscles showed high expression of CD30 during the second trimester, whereas small numbers of CD30+ TECs were found during the late first trimester. No statistically significant difference was found concerning CD30+ TECs in the cortex. CD30 was expressed by ISH in many cells in the medulla and along the septa, whereas the cortex showed little if any expression. Accordingly, a higher CD30 expression was found in medullary than in cortical thymocytes. CONCLUSIONS: Comparison of CD30 expression by TECs and thymocytes during the late first trimester and second trimester suggests an important role for CD30 in thymic selection.     

Selective antidopaminergic effects of S(+)N-n-propylnoraporphines in limbic versus extrapyramidal sites in rat brain: comparisons with typical and atypical antipsychotic agents

Dopamine (DA), injected unilaterally into rat forebrain after pretreatment with a monoamine oxidase inhibitor, equipotently induced locomotor arousal when placed in the nucleus accumbens septi (a limbic site) and contralateral deviation of the head when placed in the corpus striatum (an extrapyramidal target); testing was done with an ED₅₀ dose of DA (16 µg). Systemic injections (IP) of the representative typical neuroleptic haloperidol showed high potency and minorstriatal selectivity against the behavioral effects of intracerebral DA [accumbens ID₅₀=0.090, striatum=0.027 mg/kg (0.24 and 0.072 µmol/kg); ID₅₀ ratio=3.3, favoring striatum]. The atypical antipsychotic agent clozapine was less potent against DA in both brain regions but, paradoxically, showed ever greater striatal selectivity [ID₅₀=12 and 1.4 mg/kg (37 and 4.2 µmol/kg); ratio=8.8, favoring striatum], while its analog, the piperazinyl-dibenzothiazepine ICI-204,636 showed intermediate potency and the lowest striatal selectivity of these three neuroleptic agents [ID₅₀=1.8 and 0.88 mg/kg (4.1 and 2.0 µmol/kg); ratio=2.1]. In striking contrast, the S(+) isomers of N-n-propylnorapomorphine, its orally active 10,11-methylenedioxy prodrug derivative, and its 11-monohydroxy analog all induced potent antagonism oflimbic DA but had little effect on extrapyramidal injections of DA except at high systemic doses [ID₅₀, accumbens=0.18–0.52, striatal=10–15 mg/kg (0.50–1.6 and 29–42 µmol/kg); regional ID₅₀ ratios=18–69, favoring accumbens]. The S(+)aporphines showed limbic potency similar to that of haloperidol and 25–73 times greater than that of clozapine. The S(+)11-OH-aporphine was 2.7–3.1 times more potent (on a molar dose basis) than the other aporphines against DA in accumbens, and 0.5, 8 and 73 times as potent as haloperidol, ICI-204,636 and clozapine. The significantly dissimilar slopes of dose-effect functions for the two groups of agents suggest that different actions may mediate the limbic effects of the aporphines and the neuroleptics tested. ICI-204-636 appears to be pharmacologically similar to clozapine, but 2.1 times more potents versus limbic-DA. The S(+)N-n-propylnoraporphines are potent and regionally highly selectivelimbic DA antagonists and S(+)-11-hydroxy-N-n-propylnoraporphine is orally active. These and other aporphine analogs are proposed for development as potential atypical antipsychotic agents with a low risk of extrapyramidal neurological side effects, and the present methods are proposed for predicting relative limbic versus extrapyramidal antidopaminergic activity.     

Tyrosine prevents effects of hyperthermia on behavior and increases norepinephrine

Tyrosine (TYR) is the precursor of the catecholamine (CA) neurotransmitters, dopamine (DA) and norepinephrine (NE). Catecholamines, especially NE, participate in the response of the brain to acute stress. When animals are acutely stressed, NE neurons become more active and tyrosine availability may be rate-limiting. Tyrosine administration, before exposure to physical and/or environmental stressors including cold, reduces the adverse behavioral, physiological and neurochemical consequences of the exposure. In this study, the effects of tyrosine (400 mg/kg) were examined on rats exposed to heat stress, for which its effects have not been examined. Coping behavior and memory were assessed using the Porsolt swim test and the Morris water maze. Release of hippocampal NE and DA was assessed with in vivo microdialysis. In vehicle-treated animals, heat impaired coping and memory, and increased release of NE, but not DA. In heated animals receiving tyrosine, coping was not impaired and NE release was sustained, thus demonstrating tyrosine protects against the adverse effects of heat, and suggesting these effects result from increased central NE release. This study indicates the effects of tyrosine generalize across dissimilar stressors and that tyrosine administration may mitigate the adverse behavioral effects of heat and other stressors on humans. In addition, it demonstrates that moderate heat stress impairs coping behavior, as well as working and reference memory.     

Duplication of Xq26.2-q27.1, including SOX3, in a mother and daughter with short stature and dyslalia

Duplications of the distal long arm of the X chromosome are rare and carrier females are usually phenotypically normal. We report on a 14-year-old short statured (height and weight <3rd centile) girl with dup(X)(q26.2q27.1) inherited from a short mother. The proband has minor dysmorphic features, lordosis, lack of menarche, late signs of puberty, low prepuberal levels of gonadotrophins and steroids, but borderline low IGF-1 and normal IGF-Bp3 serum levels. Both the proposita and her mother have severe speech problems with stuttering and dyslalia. The 44-year-old mother with a strikingly aged face and a prominent nose, had menarche at 15 years. Both maternal sisters and the grandmother of the proposita are also short. Karyotyping revealed an additional band at Xq26 in all metaphases from the proband, her mother, and two maternal aunts. Molecular cytogenetic investigations revealed an Xq26.2-q27.1 direct duplication of approximately 7.5 Mb that encompasses or disrupts the SOX3 gene, which maps at the distal border of the duplicated segment. A similar chromosomal duplication was reported recently in five families and in each was associated with an abnormal phenotype in males with short stature [Hol et al., 2000; Solomon et al., 2002, 2004]. Using an androgen-receptor (HUMARA) gene methylation assay and FISH, we show that despite preferential inactivation of the dup(Xq) chromosome a significant proportion of lymphocytes in both mother and daughter carry an active duplicated X chromosome. Our findings further suggest that a dosage effect of SOX3 may to be responsible for a speech disorder in addition to short stature secondary to hypopituitarism.     

RAG1/2 re-expression causes receptor revision in a model B cell line

The expression of RAG1 and RAG2 is essential for V(D)J rearrangement of the immunoglobulin (Ig) locus in developing B cells. In mature B cells further V(D)J rearrangement is suppressed and RAG1/2 proteins decline to undetectable levels. However, there is evidence that mature B cells in the periphery may re-express RAG1/2. In humans evidence of RAG1/2 re-expression is often linked with an autoimmune state, indicating that further understanding of re-expression may be crucial to understanding immune disorders. We have investigated the molecular consequences of RAG1/2 expression in mature lymphocytes using a cell culture system (M12 and DR3). M12 (IgG+, Igkappa+ and RAG-) is a mouse B cell lymphoma. DR3 is a RAG1+/RAG2+ line derived from M12 by introduction of stable plasmids carrying RAG1 and RAG2 cDNAs. RAG1/2 mediated receptor revision occurs in the DR3 line, as evidenced by both the deletion of the endogenous rearranged Igkappa gene segment (present in the parent M12 lines) and the presence of a new Iglambda rearrangement. Gene expression profiles obtained through microarray analysis and RT-PCR found differences in expression levels between the two lines for: fibronectin, lysyl oxidase, TAP2, B220, Igkappa, TIS11B, HMG2 and DNAPKcs. Thus, the expression of RAG1/2 in a previously RAG- cell line results in multiple changes to the gene expression profile as well as receptor revision. The significance of the changes found in this model of RAG re-expression is discussed.