Polystomatidae (Monogenea) of Anura in southern Africa: Polystoma testimagna n. sp. parasitic in Strongylopus f. fasciatus (Smith, 1849)

Polystoma testimagna n. sp. is described as a new species of the Polystomatidae, parasitic in the urinary bladder of the striped stream frog Strongylopus f. fasciatus collected in the Vernon Crookes Nature Reserve, Natal, South Africa. Parasite prevalence was found to be 50.0% and 27.7% in two successive years, and the mean intensity was 1.5 and 1.6, respectively. The species occurs together with another Polystoma species in the same water body and within one kilometre from a third species. Aspects of host specificity are discussed and data on the ecology and distribution of the host presented.     

Rank relations among sisters in semi-free-ranging Barbary macaques (Macaca sylvanus)

Although semi-free-ranging Barbary macaque females are able to outrank older females from lower-ranking matrilines (matrilineal rank acquisition), they do not systematically outrank their older sisters, as is known to be the case for semi-free-ranging rhesus monkeys (Macaca mulatta) and Japanese macaques (Macaca fuscata). We test the hypothesis that differences in the support received by younger sisters against their older sisters and against older lower-ranking females might account for this interspecific difference. Thirty-one sister dyads, members of a group of 109 Barbary macaques living at La Montagne des Singes, France, were observed during 16 months. The results indicate that (1) all females were dominant to their younger sisters, and the latter were never observed to challenge their older sisters; (2) younger sisters received as much kin support against their older sisters as against older lower-ranking females; (3) only very young females received support from their kin against their older sisters; (4) younger sisters received much more support from nonkin females against lower-ranking females than against their older sisters; and (5) Barbary macaque females appear to be supported against their older sisters less frequently than rhesus macaque females are. We conclude that the lack of nonkin support is the main factor accounting for the failure of younger sisters to outrank their older sisters in Barbary macaques. Initially this might result from kin support not being sufficient to induce younger sisters to challenge and to solicit support against their older sisters.     

Contrasting effects of PACAP and carbachol on [Ca]i and inositol phosphates in human neuroblastoma NB-OK-1 cells

The effects of PACAPs on [Ca²⁺]_i were compared to those of carbachol in human neuroblastoma NB-OK-1 cells. PACAP(1–27) and PACAP(1–38) increased [Ca²⁺]_i in a biphasic manner: a transient rise and a secondary plateau. The transient phase reflected the mobilization of [Ca²⁺]_i pool(s) via the inositol phosphate pathway. The modest sustained plateau required extracellular Ca²⁺. Carbachol also increased [Ca²⁺]_i in a biphasic manner, but it mobilized intracellular Ca²⁺ pool(s) with a higher efficacy than PACAPs, then greatly increased Ca²⁺ entry, this being accompanied by a more marked and prolonged elevation of IP₃ and IP₄ than with PACAPs. It is likely that cAMP-mediated phosphorylations due to PACAPs facilitated desensitization at the PACAP receptor-phospholipase C level, so that there was less Ca²⁺ handling through PACAP receptors than with muscarinic M₁ receptors.     

Development and validation of a high-performance liquid chromatographic method for the determination of methocarbamol in human plasma

An isocratic HPLC method was developed and validated for the quantitation of methocarbamol in human plasma. Methocarbamol and internal standard in 200 μl of human plasma were extracted with ethyl acetate, evaporated to dryness and reconstituted in water. Separation was achieved on a reversed-phase C₁₈ column with a mobile phase of methanol—0.1 M potassium phosphate monobasic—water (35:10:55, v/v/v). The detection was by ultraviolet at 272 nm. Linearity was established at 1–100 μg/ml (r > 0.999). The limit of quantitation was designed as 1 μg/ml to suit pharmacokinetic studies. Inter-day precision and accuracy of the calibration standards were 1.0 to 3.6% coefficients of variance (C.V.) and −2.0 to +1.6% relative error (R.E.). Quality controls of 3, 20 and 70 μg/ml showed inter-day precision and accuracy of 2.5 to 3.6% C.V. and −0.9 to −0.4% R.E. Recovery of methocarbamol was 91.4–100.3% in five different lots of plasma. The method was shown to be applicable on different brands of C₁₈ columns.     

Renal eicosanoids and blood pressure in genetically hypertensive rats of the lyon strain

The present paper reviews the evidence for a possible involvement of renal eicosanoids in the pathophysiology of high blood pressure in genetically hypertensive rats of the Lyon strain. Both in vivo and in vitro experiments suggest that an increased ability to synthesize the vasoconstrictor prostaglandin H₂ and/or thromboxane A₂ in renal vessels (1) acts as an autocrine amplifier of pressor agents and (2) may contribute to resetting the pressure natriuresis curve which is a prerequisite for the development and maintenance of hypertension.     

Characterization of a strain of cerebral endothelial cells derived from goat brain which retain their differentiated traits after long-term passage

Summary A strain of cerebral endothelial cells was established from isolated cortical microvessels of caprine brain. These cells, which are referred to as ECl cells, can be routinely subcultured to 32 passages without the loss of differentiated morphologic and immunologic traits. The ability to routinely subculture ECl cells is an important asset, given that isolated cerebral endothelial cells in mammals generally lose their differentiated traits after only 2 to 3 passages. ECl cells were shown to contain Factor VIII-related antigen, which is a specific marker for cells of endothelial origin. ECl cells morphologically demonstrated a scarcity of pinocytotic vesicles on their apical surfaces, a lack of trans-cytoplasmic vesicles, and the ability to form in culture confluent monolayers with tight junctional complexes. Therefore, ECl cells possess specific antigenic and ultrastructural features which classify them as being small vessel endothelial cells of the blood-brain barrier type. Cytogenetic evaluation of ECl cells demonstrated a normal female goat 60,XX karyotype and confirmed the apparent non-transformed nature of ECl cells due to the lack of chromosome abnormalities or rearrangements. Using scanning electron microscopy, ECl cells were also shown to form confluent monolayers on mixed nitrocellulose filters, a feature that will enable the development of an in vitro system to study trans-endothelial transport. Given that ECl cells are readily subcultured and grow well on nitrocellulose filters, and that they resemble cerebral endothelium in vivo, it seems evident that ECl cells can be used as a versatile model for the study of blood-brain barrier function, regulation, and pathology.     

The Presence of (+)-S-Adenosyl-l-Methionine in the Rat Brain and Its Lack of Effect on Phenylethanolamine N-Methyltransferase Activity

Abstract: (+)-S-Adenosyl- l -methionine [(+)-SAM] was isolated from rat brain and was quantified by HPLC followed by UV spectrophotometric measurements and by ¹H-NMR. Its estimated ratio in brain is 3% of total SAM. Because of its commercial unavailability, (+)-SAM was also prepared from chemically synthesized SAM by separation of the two diastereoisomers on a preparative reverse-phase Nucleosil C8 column. The (+) diastereoisomer thus obtained was then assayed in vitro both as an inhibitor and a substrate of phenylethanolamine N -methyltransferase. Enzymatic activity was measured by HPLC analysis. It was shown that (+)-SAM has no effect on phenylethanolamine N -methyltransferase activity; therefore, it is unlikely that (+)-SAM plays any possible role in regulation of adrenaline synthesis in the brain.     

Electrophoretic karyotypes of the elm tree pathogen Ophiostoma ulmi (sensu lato)

Pulsed field gel electrophoresis using OFAGE, TAFE, and CHEF systems has been used to more fully characterize karyotypic variation within the two closely related fungal species of Ophiostoma ulmi sensu lato. Twelve wild-type and laboratory strains, representing the less agressive species O. ulmi and both of the biotypes of the more aggressive species O. novo-ulmi were studied and their karyotypes determined. Depending on the strain, a minimum of four to a minimum of eight chromosomal DNA bands were present that fall into three distinct size classes, with one exception. Strain CESSI6K (O. novo-ulmi, North American aggressive subgroup) contains a unique chromosomal DNA band which comigrated near a Saccharomyces cerevisiae chromosome of 0.95 Mb. This unique band was the smallest O. ulmi s. l. chromosomal DNA observed. Seven of the twelve strains shared a common chromosomal DNA banding pattern, whereas each of the other five had a unique karyotype. There was no correlation between chromosome profile and species, as some O. novo-ulmi and O. ulmi strains shared common electrophoretic karyotypes.     

Opa-like repeats in the genome of the Medfly Ceratitis capitata

The sequence determination of several genomic clones isolated from the Mediterranean fruitfly Ceratitis capitata identified the existence of opa-like repeats, often more than one being clustered in small chromosomal segments. These repeats have previously been shown to consist of stretches of tandemly reiterated glutamine-encoding residues, and they are found in multiple genes of several organisms. Most of the repeats described here are flanked or interrupted by stop codons in all reading frames and, thus, could not possibly be part of protein-coding sequences. Furthermore, these repeats, of which there are several hundred in the genome of the Medfly, can be used effectively for the determination of sequence polymorphisms, providing a convenient approach to obtain additional landmarks for the construction of genomic maps of this economically important insect.This paper is dedicated to the memory of our colleague and friend Dr. Jim Flach who took part in the initial phase of this work and died during the course of the investigation.     

Comparative efficacy of amphotericin B,clotrimazole and itraconazole againstAspergillus spp.

The susceptibilities of two isolates ofAspergillus flavus, one from a human case of recalcitrant mycotic keratitis, and an environmental isolate ofA. fumigatus, to itraconazole, clotrimazole and amphotericin B were measured. Observations of macroscopic growth and microscopic evaluations of conidia germination both indicated that the two isolates ofA. flavus were markedly more resistant to amphotericin B than to itraconazole and clotrimazole. Itraconazole was more effective than clotrimazole for all isolates. Ourin vitro susceptibility results suggest the use of itraconazole should be a primary consideration in the treatment ofAspergillus keratitis.