Astrocyte–neuron interactions in neurological disorders

Astrocytes have long been considered as just providing trophic support for neurons in the central nervous system, but recently several studies have highlighted their importance in many functions such as neurotransmission, metabolite and electrolyte homeostasis, cell signaling, inflammation, and synapse modulation. Astrocytes are, in fact, part of a bidirectional crosstalk with neurons. Moreover, increasing evidence is stressing the emerging role of astrocyte dysfunction in the pathophysiology of neurological disorders, including neurodegenerative disease, stroke, epilepsy, migraine, and neuroinflammatory diseases.     

A New Real-Time PCR for the Detection of Plasmodium ovale wallikeri

It has been proposed that ovale malaria in humans is caused by two closely related but distinct species of malaria parasites: P. ovale curtisi and P. ovale wallikeri. We have extended and optimized a Real-time PCR assay targeting the parasite’s small subunit ribosomal RNA (ssrRNA) gene to detect both these species. When the assay was applied to 31 archival blood samples from patients diagnosed with P. ovale, it was found that the infection in 20 was due to P. ovale curtisi and in the remaining 11 to P. ovale wallikeri. Thus, this assay provides a useful tool that can be applied to epidemiological investigations of the two newly recognized distinct P. ovale species, that might reveal if these species also differ in their clinical manifestation, drugs susceptibility and relapse periodicity. The results presented confirm that P. ovale wallikeri is not confined to Southeast Asia, since the majority of the patients analyzed in this study had acquired their P. ovale infection in African countries, mostly situated in West Africa.     

Fluorimetric determination of carbamoyl phosphate

A simple fluorimetric assay for the determination of carbamoyl phosphate in tissue extracts is described. In the assay, production of ATP from carbamoyl phosphate and ADP by carbamate kinase is coupled to the formation of NADPH, using glucose, hexokinase, NADP⁺, and glucose-6-phosphate dehydrogenase. Production of NADPH in this system proved to be equal to the amount of carbamoyl phosphate present.     

Vaginal treatment with a prostaglandin F2 alpha derivative (alfaprostol) for inducing labor in pregnancy at term

The effectiveness and acceptability of Alfaprostol (an analog of PGF2 alpha) in inducing labor were assessed in 20 pregnant women at term. All subjects had no spontaneous uterine activity before treatment and the mean (M +/- SE) Bishop score was 2.45 +/- 0.21. The drug was administered by vaginal route at the dose of 10 mg every 3 hours. Regular uterine contractions appeared in all patients and delivery occurred in 85% of the patients after a mean time of 9h50min +/- 0h55min following the start of treatment. The mean dose of Alfaprostol utilized to achieve delivery was 29.4 +/- 2.0 mg. No major side effects were noted in the mothers and their fetuses at any time during treatment. Two patients exhibited vomiting. The Apgar score of all newborns at birth was 8 or more. These results suggest the usefulness of Alfaprostol to induce labor in pregnant women at term, as it has oxytocic activity without adverse effects on either the mother or the fetus.     

Autoradiographic localization of vasoactive intestinal polypeptide receptors in the rat mesenteric vascular tree

By the use of combined in vitro radioreceptor binding and autoradiographic techniques, we analyzed the pharmacological properties and the anatomical localization of the vasoactive intestinal polypeptide (VIP) receptor in rat superior mesenteric artery and in medium and small mesenteric artery branches. 125I-VIP was bound by sections of rat superior mesenteric artery in a manner consistent with the labeling of specific VIP receptors, with Kd and Bmax values of 0.23 nM and 0.71 pmol/mg protein respectively. Inhibition of 125I-VIP binding with VIP and related peptides gives the following rank order of potency: VIP greater than peptide histidine methionine greater than secretin. Light microscope autoradiography reveals specific VIP binding sites within the medial layer of superior mesenteric artery and its branches. Medium and small sized vessels are richer in 125I-VIP binding sites than the larger ones.     

Synthesis of rhodanese in Hep 3B cells

Summary The biosynthesis of rhodanese was studied in human hepatoma cell lines by immunoblotting and pulselabeling experiments using polyclonal antibodies raised against the bovine liver enzyme. Rhodanese, partially purified from human liver, showed an apparent molecular weight of 33,000 daltons, coincident with that of rhodanese from Hep 3B cells. After pulse labeling of Hep 3B cells both at 37°C and 25°C, rhodanese in the cytosol fraction exhibited the same molecular weight as the enzyme isolated from the particulate fraction containing mitochondria. Moreover, newly synthesized rhodanese from total Hep 3B RNA translation products showed the same electrophoretic mobility as rhodanese from Hep 3B cells. These results suggest that rhodanese, unlike most mitochondrial proteins, is not synthesized as a higher molecular weight precursor.     

Accumulation and Interconversion of Amino Acids in Rice Roots under Anoxia

In excised rice roots, anaerobic degradation of proteins gaverise to an increase of free-amino acids. Anoxic accumulationof alanine, -aminobutyric acid and proline was the consequenceof the interconversion of glutamate, aspartate and amides. Theshift in the composition of the amino acid pool appears to becaused by changes in keto acid levels. The role of reactionsinvolved in amino acid interconversion and the physiologicalsignificance of these interconversions are considered and discussed. (Received November 25, 1988; Accepted June 9, 1988)