Differences between cell lines of uterine cervical glassy cell carcinoma and large cell nonkeratinizing squamous cell carcinoma.

Cell lines were established from two uterine cervical cancers, a glassy cell carcinoma (GCC) and a large cell nonkeratinizing squamous cell carcinoma (LCSC), and studied by a variety of techniques, including histology, chromosome analysis, heterotransplantation and tumor marker analyses. There were radical differences in the morphology, heterotransplantability, production of tumor markers, etc., between the cultures of these morphologically similar cancers. The LCSC line (HKMUS) consisted of polygonal and round cells containing tonofilaments; these cells discharged tumor antigen-4 (TA-4) into the conditioned media. HKMUS was heterotransplantable into the subcutis of nude mice to form LCSC. On the other hand, the GCC line (HOKUG) consisted of round or spindle-shaped cells. HOKUG was easily transplanted into the subcutis or intraabdominal cavity of nude mice and metastasized easily. It discharged TA-4, carbohydrate antigen 125 (CA125) and neuron-specific enolase (NSE) into the conditioned media. The histologic picture of GCC revealed numerous blood vessels and a rapid proliferation of the cells. GCC, which is considered to be a mixed carcinoma having the characteristics of both squamous carcinoma and adenocarcinoma, seems to be a cancer of unpredictable prognosis as compared to LCSC, possibly due to its rapid proliferation and easy metastasis, leading to peritonitis carcinomatosa.     

Thiamine-Binding Protein of Escherichia coli

The ability to transport thiamine in Escherichia coli was reduced by osmotic shock treatment with a concomitant release of a thiamine-binding protein; its formation was repressed by thiamine added to the growth medium.     

Purification and some properties of membrane-associated phospholipase A2 of human spleen

Membrane-associated phospholipase A2 was purified to homogeneity from human spleen. The enzyme was solubilized from the particulate fraction by the addition of KBr, and purified by reverse-phase high-performance liquid chromatography. The estimated molecular weight of the enzyme was 14,000. The enzyme had a pH optimum around 9.5, required the presence of Ca2+ for its activity, and hydrolyzed phosphatidylethanolamine more efficiently than phosphatidylcholine.     

Inhibition of Thiamine Transport by Chloroethylthiamine in Escherichia coli

Chloroethylthiamine was found to inhibit an entrapment of thiamine as thiamine monophosphate by blocking thiamine monophosphokinase in the cytoplasm after thiamine was taken up by the cells of Escherichia coli.     

Mutation associated with an autosomal dominant cone-rod dystrophy CORD7 modifies RIM1-mediated modulation of voltage-dependent Ca2+ channels

Genetic analyses have revealed an association between the gene encoding the Rab3A-interacting molecule (RIM1) and the autosomal dominant cone-rod dystrophy CORD7. However, the pathogenesis of CORD7 remains unclear. We recently revealed that RIM1 regulates voltage-dependent Ca(2+) channel (VDCC) currents and anchors neurotransmitter-containing vesicles to VDCCs, thereby controlling neurotransmitter release. We demonstrate here that the mouse RIM1 arginine-to-histidine substitution (R655H), which corresponds to the human CORD7 mutation, modifies RIM1 function in regulating VDCC currents elicited by the P/Q-type Ca(v)2.1 and L-type Ca(v)1.4 channels. Thus, our data can raise an interesting possibility that CORD7 phenotypes including retinal deficits and enhanced cognition are at least partly due to altered regulation of presynaptic VDCC currents.     

Neurogenic adaptation contributes to the afferent response to mechanical stimulation

This study aimed to characterize the effect of mechanical stimuli on mesenteric afferent nerve signaling in the isolated rat jejunum in vitro. This was done to determine the effect of mechanical stresses and strains relative to nonmechanical parameters (neurogenic adaptation). Mechanical stimulations were applied to a segment of jejunum from 15 rats using ramp distension with water at three rates of distension, a relaxation test (volume maintained constant from initial pressure of 20 or 40 mmHg), and a creep test (pressure maintained constant). Circumferential stress and strain and the spike rate increase ratio were calculated for evaluation of afferent nerve activity during the mechanical stimulations. Ramp distension evoked two distinct phases of afferent nerve signaling as a function of circumferential stress or strain. Changing the volume distension rate did not change the stress-strain relationship, but faster distension rate increased the afferent firing rate (P < 0.05). In the stress relaxation test, the spike rate declined faster and to a greater extent than the stress. In the creep test, the spike rate declined, despite a small increase in the strain. Three classes of mechanosensitive single-afferent units (low, wide dynamic range, and high threshold units) showed different response profiles against stress and strain. Low-threshold units exhibited a near linear relationship against the strain (R(2) = 0.8095), whereas high-threshold units exhibited a linear profile against the stress (R(2) = 0.9642). The afferent response is sensitive to the distension speed and to the stress and strain level during distension. However, the afferent nerve response is not a simple function of either stress or strain. Nonmechanical time-dependent adaptive responses other than those related to viscoelasticity also play a role.     

Dioxin immunosensor using anti-2,3,7,8-TCDD antibody which was produced with mono 6-(2,3,6,7-tetrachloroxanthene-9-ylidene) hexyl succinate as a hapten

To detect dioxin using a quartz crystal microbalance (QCM) immunosensor, anti-2,3,7,8-tetrachloro-p-dibenzodioxin (TCDD) monoclonal antibodies (MAbs) were produced as types of IgG1 and IgM, with mono 6-(2,3,6,7-tetrachloroxanthene-9-ylidene) hexyl succinate (as a hapten) conjugated with bovine serum albumin (dioxin-BSA). Furthermore, ScFv was generated from hybridoma-producing IgG1 MAb. Among these antibodies, ScFv showed excellent capability for dioxin detection using QCM immunosensors.     

Rab3-interacting Molecule γ Isoforms Lacking the Rab3-binding Domain Induce Long Lasting Currents but Block Neurotransmitter Vesicle Anchoring in Voltage-dependent P/Q-type Ca2+ Channels

Assembly of voltage-dependent Ca²⁺ channels (VDCCs) with their associated proteins regulates the coupling of VDCCs with upstream and downstream cellular events. Among the four isoforms of the Rab3-interacting molecule (RIM1 to -4), we have previously reported that VDCC β-subunits physically interact with the long α isoform of the presynaptic active zone scaffolding protein RIM1 (RIM1α) via its C terminus containing the C₂B domain. This interaction cooperates with RIM1α-Rab3 interaction to support neurotransmitter exocytosis by anchoring vesicles in the vicinity of VDCCs and by maintaining depolarization-triggered Ca²⁺ influx as a result of marked inhibition of voltage-dependent inactivation of VDCCs. However, physiological functions have not yet been elucidated for RIM3 and RIM4, which exist only as short γ isoforms (γ-RIMs), carrying the C-terminal C₂B domain common to RIMs but not the Rab3-binding region and other structural motifs present in the α-RIMs, including RIM1α. Here, we demonstrate that γ-RIMs also exert prominent suppression of VDCC inactivation via direct binding to β-subunits. In the pheochromocytoma PC12 cells, this common functional feature allows native RIMs to enhance acetylcholine secretion, whereas γ-RIMs are uniquely different from α-RIMs in blocking localization of neurotransmitter-containing vesicles near the plasma membrane. γ-RIMs as well as α-RIMs show wide distribution in central neurons, but knockdown of γ-RIMs attenuated glutamate release to a lesser extent than that of α-RIMs in cultured cerebellar neurons. The results suggest that sustained Ca²⁺ influx through suppression of VDCC inactivation by RIMs is a ubiquitous property of neurons, whereas the extent of vesicle anchoring to VDCCs at the plasma membrane may depend on the competition of α-RIMs with γ-RIMs for VDCC β-subunits.