Instaneous changes in the radial artery blood flow under different physiological conditions

Using a Doppler pulse flowmeter we measured the blood flow in the radial artery at rest and during physical exercise and various other stimuli (arithmetical calculations, electrical stimulation, deep inspiration). The mean resting flow in the radial artery was 0.66 ml/s. Every stimulus was instantaneously followed by a drop in the blood flow to a minimum value; there was no significant differences between these values. The results demonstrate that the new, non-invasive apparatus can be used to study quick changes in the blood flow not detected by routine non-invasive methods.     

Molecular cloning of a human serotonin receptor (S12) with a pharmacological profile resembling that of the 5-HT1D subtype.

We report the molecular cloning of a fragment of human genomic DNA called S12, containing an open reading frame of 1170 nucleotides, which encodes a receptor for serotonin of 390 amino acids. The receptor function of the S12 protein was demonstrated by functional expression in mouse LS12 cells obtained by stable transfection of Ltk- cells, and LM5S12 cells, derived from LM5 cells (Ltk- cells previously transfected with the M5 muscarinic acetylcholine receptor). Adenylyl cyclase studies showed that the S12 receptor is able to mediate inhibition of adenylyl cyclase in response to serotonin in both types of cells. As studied in LM5S12 cells, the S12 receptor did not promote Ca2+ mobilization from internal stores, nor did it significantly modulate the sustained increase in [Ca2+]i elicited by stimulation of the phospholipase C stimulating M5 acetylcholine receptor. The pharmacologic profile of S12 as seen in adenylyl cyclase assays is as follows: (EC50 in nM): serotonin, full agonist (37 nM), 5-carboxamidotryptamine, full agonist (10 nM), sumatriptan, full agonist (50 nM), metergoline, partial agonist (10 nM), methysergide, partial agonist (40 nM), yohimbine, partial agonist (150 nM), metitepin, antagonist (KB = 0.7 to 1.2 nM). We propose that the human S12 serotonin receptor is a receptor of the 5-hydroxytryptamine1D subtype.     

HLA-binding regions of HIV-1 proteins. I. Detection of seven HLA binding regions in the HIV-1 Nef protein.

The physical association of HLA class I or H-2 molecules with 36 HIV-1 Nef synthetic peptides was studied using a direct peptide binding assay (PBA) in solid phase. To assess the functional significance of the PBA results, the Nef peptides were also tested for their ability to inhibit the lytic activity of human or murine CTL. The PBA results showed that seven partly overlapping regions of the Nef protein contained MHC binding peptides (4-18, 46-67, 73-94, 100-128, 126-155, 182-198, and 192-206). Five of these seven regions included all the already described epitopes recognized by CD8+ human CTL. The two other regions, 4-18 and 46-67, are not yet described as antigenic for human CD8+ cells but they are located in the N-terminal part of Nef that was previously described as being stimulator for rat or chimpanzee CD4+ cells. Altogether, it can be concluded that 1) In virtually 100% of the cases, the PBA is capable to detect known antigenic peptides recognized by CTL. 2) The PBA and the functional inhibition assay provide similar results, supporting the functional significance of PBA results. 3) The PBA is easy to handle on a large scale, using multiple peptide and several MHC molecules, so that it can be used as a routine method for prevision of possibly epitopic sequences. 4) Systematic studies of peptides issued from the whole sequence of a given protein allow to map polyepitopic areas that are probably the most interesting parts of proteins for a vaccine purpose.     

Minimally-invasive Technique for Injection into Rat Optic Nerve

The rat optic nerve is a useful model for stem cell regeneration research. Direct injection into the rat optic nerve allows delivery into the central nervous system in a minimally-invasive surgery without bone removal. This technique describes an approach to visualization and direct injection of the optic nerve following minor fascial dissection from the orbital ridge, using a conjunctival traction suture to gently pull the eye down and out. Representative examples of an injected optic nerve show successful injection of dyed beads.     

Molecular Characterization of Larval Peripheral Thermosensory Responses of the Malaria Vector Mosquito Anopheles gambiae

Thermosensation provides vital inputs for the malaria vector mosquito, Anopheles gambiae which utilizes heat-sensitivity within a broad spectrum of behaviors, most notably, the localization of human hosts for blood feeding. In this study, we examine thermosensory behaviors in larval-stage An. gambiae, which as a result of their obligate aquatic habitats and importance for vectorial capacity, represents an opportunistic target for vector control as part of the global campaign to eliminate malaria. As is the case for adults, immature mosquitoes respond differentially to a diverse array of external heat stimuli. In addition, larvae exhibit a striking phenotypic plasticity in thermal-driven behaviors that are established by temperature at which embryonic development occurs. Within this spectrum, RNAi-directed gene-silencing studies provide evidence for the essential role of the Transient Receptor Potential sub-family A1 (TRPA1) channel in mediating larval thermal-induced locomotion and thermal preference within a discrete upper range of ambient temperatures.     

The vascular plant collections of R. S. Williams from Bolivia and Peru (1901–1902): Addenda et corrigenda

Notes that augment an earlier essay on R. S. Williams’ botanical activities and the distribution of his collections from Bolivia and Peru are presented. Twelve species based on Williams’ vascular plant collections are added to a catalog that was previously published. Synonymies of an additional 22 taxa are corrected or updated. Notes also are provided concerning the typification or orthography of two species.     

The oncolytic peptide LTX-315 triggers necrotic cell death

The oncolytic peptide LTX-315 has been designed for killing human cancer cells and turned out to stimulate anti-cancer immune responses when locally injected into tumors established in immunocompetent mice. Here, we investigated the question whether LTX-315 induces apoptosis or necrosis. Transmission electron microscopy or morphometric analysis of chromatin-stained tumor cells revealed that LTX-315 failed to induce apoptotic nuclear condensation and rather induced a necrotic phenotype. Accordingly, LTX-315 failed to stimulate the activation of caspase-3, and inhibition of caspases by means of Z-VAD-fmk was unable to reduce cell killing by LTX-315. In addition, 2 prominent inhibitors of regulated necrosis (necroptosis), namely, necrostatin-1 and cycosporin A, failed to reduce LTX-315-induced cell death. In conclusion, it appears that LTX-315 triggers unregulated necrosis, which may contribute to its pro-inflammatory and pro-immune effects.     

Murine xenotropic type C viruses I. Distribution and further characterization of the virus in NZB mice.

The xenotropic mouse type C virus, originally detected in cultured embryo cells from New Zealand Black (NZB) mice, has been recovered from over 50 adult NZB animals and 15 NZB embryos. Its presence is best detected by measuring its ability to rescue a murine sarcoma virus (MSV) genome from a non-virus-producing MSV-transformed rat cell. The virus can serve as a helper for replication of MSV. It has a distinct type-specific coat and is a prototype for a third serotype of mouse type C viruses, NZB. The xenotropic virus may have an evolutionary role since it has a wide host range, including the ability to infect avian cells. It is produced spontaneously by all cells cultivated from NZB tissues and accounts for the high concentration of viral antigens associated with NZB tissues. The extent of virus production is similar in both male and female mice. All cell clones established from embryos also produce the virus. A variability in the intracellular regulation of virus replication is suggested since tissue cells from the same animal differ quantitatively in their ability to produce xenotropic viruses. Since enhanced spontaneous virus production is associated with cells from NZB mice, the virus may play a role in the autoimmune disease of this mouse strain.