Release of platelet-activating factor (PAF-acether) and arachidonic acid metabolites from alveolar macrophages

Human, monkey and rat alveolar macrophages (AM) release PAF-acether in a dose-dependent fashion in the presence of 1 to 5 g/ml ionophore A 23187 (2.5 pmol of PAF-acether from 2.5×10⁵ cells) but not in the presence of zymosan. Arachidonic acid (AA) metabolites released from AM from these species were studied. Thromboxane A₂ TxA₂)—detected by its action on rabbit arteries—was released from human, monkey and rat AM upon addition of 0.5 mM AA. This release was inhibited by aspirin and indomethacin. Lipoxygenase and cyclooxygenase AA metabolites from rat AM were identified using high efficiency glass capillary column gas chromatography coupled to mass spectrometry. The cyclooxygenase metabolites PGF₂, E₂ and D₂ and TxB₂ were identified. The lipoxygenase-dependent AA metabolites were explored using aspirin-pretreated AM. Only 12 HETE was found.These data indicate that AM secrete several substances with bronchoconstrictive activity: PGF₂, D₂, TxA₂ and PAF-acether. Therefore an active role of AM in human and experimental bronchoconstriction must be considered.     

Receptivity,rejection and reactivity in female rats following kainic acid and electrolytic septal lesions

Sprague-Dawley rats were ovariectomized and received bilateral sham, electrolytic or kainic acid lesions of the septum. Kainic acid lesions are purported to destroy cell bodies while not appreciably damaging fibers of passage or afferent terminals. Following priming with estradiol benzoate (EB), animals received three consecutive tests of lordosis and rejection behavior. Animals also received six tests of reactivity; one prior to each EB priming regimen and one following each lordosis and rejection test. Reactivity measures included resistance to capture and magnitude and quantity of startle responses. Electrolytic and kainic acid lesions were equivalent in facilitating lordosis. Although both lesions also increased rejection frequency, kainic acid effects were transient and markedly smaller by 60–80%. Reactivity data generally demonstrated significantly higher scores for kainic acid and electrolytic lesions groups and apparently time-dependent decreases in these scores. The results suggest that rejection behavior is not necessarily correlated with either lordosis or hyperreactivity.     

Recurrent high level parvovirus B19/genotype 2 viremia in a renal transplant recipient analyzed by real-time PCR for simultaneous detection of genotypes 1 to 3

Organ transplant recipients infected with parvovirus B19 frequently develop persistent viremia associated with chronic anemia and pure red cell aplasia. In this study, a male renal transplant recipient who had been infected with parvovirus B19/genotype 2 after renal transplantation at the age of 34 years is described. The patient was repeatedly treated with high dose intravenous immunoglobulin (IVIG) that resulted in the resolvement of symptoms but not in virus eradication. During an observation period of 33 months after transplantation three phases associated with high parvovirus B19 viremia were observed. Both the first and the second viremic phases were combined with severe anemia. Parvovirus B19 specific IgM-antibodies were initially detected at the beginning of the second phase in continually rising concentrations. Initially eradication of the virus by immunoglobulin therapy was reported after the first viremic phase [Liefeldt et al. (2002): Nephrol Dial Transplant 17:1840-1842]. Retrospectively this statement has to be corrected. It was based on the use of a qualitative PCR assay specific for parvovirus B19 genotype 1 associated with reduced sensitivity for detection of genotype 2. After sequence analysis of the viral DNA and adjustment of a real-time PCR assay (TaqMan) for quantitative detection of all three B19 virus genotypes analysis of consecutive serum samples allowed the demonstration of long lasting phases with reduced viral loads following IVIG-treatment. These results demonstrate that IVIG treatment of parvovirus B19-triggered anemia in transplant recipients offers an opportunity to resolve symptoms, but does not guarantee eradication of the virus. Since reactivation of parvovirus B19 infection can result in high virus load associated with the recurrence of symptoms repeated screening for viral DNA is recommended using the TaqMan system established for quantitative detection of all three genotypes of parvovirus B19.     

Facilitation of lordosis behavior in rats by social isolation: Adrenal mediation

Ovariectomized rats were housed either singly or in groups of three, with housing density kept constant. Subcutaneous injections of 0.8 μg estradiol benzoate (EB) were administered daily, beginning 6 days after surgery. The first two experiments provided evidence that isolation facilitated lordosis within 3 days of initial EB administration. Other behavioral components of female sexual receptivity were not affected. The third experiment involved comparison of the effects of isolation in ovariectomized and adrenalectomized-ovariectomized rats. Isolation again significantly facilitated lordosis in ovariectomized rats but no such trend was apparent in adrenalectomized rats even though high levels of lordosis were evident in these animals. One possible interpretation of this latter finding is that isolation of female rats facilitates estrogen-induced lordosis by increasing adrenocortical secretion. The present series of experiments demonstrate that social isolation can influence sexual receptivity in rodents.     

Effects of aging on hypothalamic-pituitary-adrenal system function in non-human primates

The study was aimed at characterizing the changes in hypothalamic-pituitary-adrenal (HPA) axis function during aging in monkey models (Papio hamadryas and Macaca mulatta). It has been established by specific radioimmunoassay and enzyme immunoassay that basal plasma levels of adrenal androgenes (dehydroepiandrosterone-DHEA, dehydroepiandrosterone sulfate-DHEAS) and the early precursors of steroid hormones (pregnenolone and 17-hydroxypregnenolone) progressively decrease with age in baboons and macaques, while cortisol and 11-desoxycortisol concentrations do not change. The old female rhesus monkeys exhibited a higher cortisol and corticosterone response, but a lower DHEAS response to corticotropin-releasing hormone (CRH) administration then the young monkeys. The aged rhesus monkeys also exhibited a decrease of the adrenal cortex resiliency, that was manifested in the deceleration of the decrease of cortisol concentrations after the peak values had been reached in response to ACTH 1-39 administration. At the same time the ACTH 1-24 depot test revealed no age-related changes in the maximum capacity of monkey adrenals to synthesize and secrete cortisol. The aged monkeys also developed less sensitivity of the HPA axis to dexametasone suppression test. The age-related hormonal changes may play an important role in the age-related involutive processes and in the disorders of the adaptive ability of old organisms.     

Origin and primary dispersal of the Mycobacterium tuberculosis Beijing genotype: clues from human phylogeography

We suggest that the evolution of the population structure of microbial pathogens is influenced by that of modern humans. Consequently, the timing of hallmark changes in bacterial genomes within the last 100,000 yr may be attempted by comparison with relevant human migrations. Here, we used a lineage within Mycobacterium tuberculosis, a Beijing genotype, as a model and compared its phylogeography with human demography and Y chromosome-based phylogeography. We hypothesize that two key events shaped the early history of the Beijing genotype: (1) its Upper Palaeolithic origin in the Homo sapiens sapiens K-M9 cluster in Central Asia, and (2) primary Neolithic dispersal of the secondary Beijing NTF::IS6110 lineage by Proto-Sino-Tibetan farmers within east Asia (human O-M214/M122 haplogroup). The independent introductions of the Beijing strains from east Asia to northern Eurasia and South Africa were likely historically recent, whereas their differential dissemination within these areas has been influenced by demographic and climatic factors.     

Morphological and morphometric characteristics of choroid plexus psammoma bodies during the human aging

Psammoma bodies are one of many choroid plexus aging changes which origin is still enigma for the scientists. During our investigation psammoma bodies were studied on 30 postmortem brains by light microscopy. They stained red with HE, and were PAS and AB PAS positive. The largest number of lamellas were stained blue with Mallory's connective tissue stain, except peripheral and next to the center lamella which stained red. During the aging, psammoma bodies became larger and more irregular, which was followed with group area and perimeter, single psammoma body average area and average perimeter, average diameter and contour index increase. Psammoma bodies mearged in the second and the third age group and mearging process led to larger and more irregular structures formation. The results of this investigation suggest that psammoma bodies are more frequent in choroid plexus of healthy older people and during the aging they obtain larger dimensions, more irregular contours, which is the result of their mutual mearging.     

Ligand-exchange chromatography of racemates, 9. Ligand-exchange chromatography of amino acid enantiomers on asymmetric sorbents with polydentate sulfur containing groupings

The paper describes the syntheses of four asymmetric sorbents, which contain S-(2-aminoethyl)-L -cysteine ( 1a ), S-(carboxymethyl)-L -cysteine ( 1c ), S,S′-(ethylene)-bis(L -cysteine) ( 2a ), and N,N′-(ethylene)-bis(D-methionine) ( 3a ) groupings as the chiral fixed ligands in a cross-linked polystyrene matrix. The sorbents were used for ligand-exchange chromatography of amino acid enantiomers in the presence of Cu(II) and Ni(II) ions. Enantioselective effects in the formation of mixed-ligand complexes consisting of a fixed ligand, a metal ion, and an amino acid enantiomer were determined. The highest values of enantioselectivity reaching 1 300 to 1 890J/mol were found in mixed-ligand complexes containing histidine or β-phenyl-α-alanine.