The increase in the intracellular Ca2+ concentration induced by mechanical stimulation is propagated via release of pyrophosphorylated nucleotides in mammary epithelial cells

Mechanical stimulation of one mammary tumor cell in culture induced an increase in its intracellular calcium concentration which spread to surrounding cells. The increase in calcium can also be induced by addition of a solution in which cultured mammary tumor cells were stimulated by repeated pipetting (solution after pipetting cells, SAPC). The activity of the SAPC was completely abolished by treatment with snake venom phosphodiesterase or pyrophosphatase. Uridine triphosphate (UTP), uridine diphosphate (UDP) and ATP (1 M each) were detected in the SAPC, whereas 5-UMP and 5-AMP were produced by phosphodiesterase digestion. A mixture of UTP, UDP and ATP (1 M each) elicited a calcium response which was comparable to that induced by SAPC, while UTP, UDP or ATP alone at 1 M elicited a small increase in calcium concentration in mammary tumor cells. Suramin, a competitive antagonist of P₂ purinoceptors, diminished the spreading of the calcium wave induced by mechanical stimulation. It also blocked the responses to SAPC, UTP, UDP and ATP. These findings suggest that the mechanical stimulation results in the release of UTP, UDP and ATP into the extracellular space which mediates induction of the spreading calcium response via P_2U-type purinoceptors.     

Morphological features of cat thalamo-parietal projection fibers investigated by PHA-L immunohistochemistry and electron microscopy.

Thalamo-parietal fibers originating from the ventroanterior-ventrolateral (VA-VL) complex in the cat were labeled with Phaseolus vulgaris leucoagglutinin (PHA-L) and examined by light and electron microscopy. PHA-L (2.5% aqueous solution) was injected iontophoretically through micropipets with anodal current pulses into the VA-VL complex. PHA-L-labeled terminals were distributed in the lateral and the suprasylvian gyri in the superficial and deep cortical layers. In layer I, horizontal varicose fibers and terminals were conspicuous in the upper one-third and were widely distributed. In the deeper cortical layers (layers III-V), varicose fibers and terminals were detected in moderate numbers. Electron microscopic examination revealed that the labeled terminals formed asymmetrical synapses on the dendritic spines of spiny neurons. These morphological findings appeared to be consistent with our previous intracellular recordings in this cortex.     

Impact response of periodontal tissues

A new impact response method using a fracture of a pencil-lead to produce an excitation pulse is proposed. Impact excitations (rectangular pulse, triangular pulse and half-sine pulse) are strictly given in physical and mathematical definitions and complete solutions to the impact excitations are provided for Noyes' model of the human tooth. When a relatively long triangular pulse is applied to Noyes' model, which can express the physical characteristic of periodontal tissues, a sinusoidal damped vibration of a single degree-of-freedom model is approximately obtained. The acceleration response is characterised by the physical parameters (T, δ and A_o) and mechanical elements (m₁, c₁ and k) of which a single degree-of-freedom model is composed. By means of this method, the values of the parameters and elements in the cases of healthy maxillary, healthy mandibular and pathological mandibular incisors are obtained. The single degree-of-freedom model can express the high-frequency spectra of Noyes' model. The pathological tooth is characterised by a longer damped time constant and a larger acceleration maximum. This impact response method can effectively be applied to clinical diagnosis in view of the physical parameters and mechanical elements which have been derived.     

Stimulatory effect of vasoactive intestinal polypeptide on catecholamine secretion from isolated guinea pig adrenal chromaffin cells

The stimulatory effect of vasoactive intestinal polypeptide (VIP) on catecholamine (CA) secretion from isolated guinea pig adrenal chromaffin cell was studied. VIP (1-10 microM) induced dose-dependent CA secretion, which was slow and continued for at least 30 min. This VIP-induced CA secretion was dependent on the presence of Ca2+ in the medium, but no significant increase in Ca2+ uptake by the cells was observed during their stimulation with VIP. Studies on the intracellular free Ca2+ level ([Ca2+]i) using fura-2 showed that acetylcholine and muscarine induced a marked increase in the [Ca2+]i, but that VIP induced only a slight increase. Thus VIP may induce CA secretion by increasing the sensitivity of the secretion of CA to Ca2+.     

Muscarinic stimulation of guinea pig adrenal chromaffin cells stimulates catecholamine secretion without significant increase in Ca2+ uptake

In isolated guinea pig adrenal chromaffin cells, not only nicotine, but also muscarine stimulated catecholamine (CA) secretion, the stimulation by muscarine being the greater. The secretions of CA by muscarine and nicotine were both dependent on the presence of Ca2+ in the medium, but only the latter was associated with a rapid increase in 45Ca2+ uptake. Experiments with the fluorescent Ca2+ indicator quin 2, showed that muscarine caused an increase in cytoplasmic free Ca2+ concentration [( Ca2+]i). Moreover, the intracellular Ca2+ antagonist 8-(N,N-diethylamino)octyl-3,4,5-trimethoxybenzoate (TMB-8) inhibited both CA secretion and increase in [Ca2+]i induced by muscarine. These results indicate that in isolated guinea pig adrenal chromaffin cells, nicotine stimulated CA secretion by increasing Ca2+ uptake by the cells, whereas muscarine stimulated CA secretion by mobilizing Ca2+ from the intracellular pool.     

Combination therapy of cyclosporine with steroid inhibits γ-interferon and interleukin-1 gene expression at the level of mRNA synthesisin vivo

The present study examined the effect of cyclosporine (CsA) administered with steroidin vivo on the capacity of peripheral blood mononuclear cells (PBMC) from kidney transplant recipients to generate cytokines and their gene expression at the level of messenger RNA (mRNA). PBMC from CsA-prednisolone (Pred)-treated recipients displayed 66.9% inhibition (54.3±12.4 IU/ml;N=42;P<0.01) of -interferon (-IFN) production compared with normal individuals (134.6±18.6 IU/ml;N=23). Azathioprine (Az)-Pred-treated recipients displayed significantly less inhibition of -IFN generation (96.0±16.1 IU/ml;N=22;P<0.05) than CsA-treated patients. Macrophages (m) from CsA-Pred-treated recipients displayed 60.0% inhibition (5.1±0.7 U/ml;N=20;P<0.01) of interleukin-1 (IL-1) production compared with normal individuals (13.0±2.9 U/ml;N=21). These results were confirmed by the experiments using cDNA probe for -IFN or IL-1 (, ). High levels of -IFN mRNA in phytohemagglutinin (PHA)-stimulated PBMC or IL-1() mRNA in lipopolysaccharide (LPS)-stimulated m were present in normal individuals but not in CsA-treated recipients as judged by hybridization to a cloned human -IFN or IL-1() cDNA probe. These studies demonstrated that combination therapy of CsA with steroid inhibits both -IFN and IL-1 gene expression at the level of mRNA at physiological concentrations.     

Poliovirus infection of established human blood cell lines: relationship between the differentiation stage and susceptibility of cell killing

The replication of type 1 poliovirus in 13 established human blood cell lines differing in the differentiation stage and cell lineage was investigated. Three T (CCRF-CEM, CCRF-HSB-2, and Molt-3) and three B (Raji, CCRF-SB, and RPMI 8226) cell lines showed no cytopathic effects (CPE) or virus production. CPE associated with virus production were detected in the other seven cell lines: HL-60, ML-1, and KG-1 (granulocytic lineage), U-937 and THP-1 (monocytic lineage), K-562 (erythroid lineage), and Molt-4 (T cell lineage). These susceptible cell lines greatly differed in the speed at which the CPE progressed. The progression of CPE was faster in relatively well-differentiated cell lines such as HL-60 and U-937, independently of the multiplicity of infection, than in less differentiated cell lines such as K-562, KG-1, and THP-1. Thus, for the same lineage, the speed at which CPE progressed became proportionally higher with subsequent differentiation stages. In the K-562 cell culture, CPE were not observed until at least 5 days postinfection (p.i.), while more than 80% of HL-60 cells were killed within 3 days p.i. There were no significant differences between infected HL-60 and K-562 cells in the efficiency of infection determined at 8 hr p.i. by the indirect immunofluorescent technique, the rate of virus growth, or the amount of viral capsid protein synthesized. This indicated that there were similar viral replication cycles in the two cell lines. These observations suggest that the killing function of the virus is expressed more slowly in K-562 cells than in HL-60 cells.     

Use of high‐flow nasal cannula in neonates: Nationwide survey in Japan

High‐flow nasal cannula is a new modality of respiratory support and is increasing in popularity despite the lack of supporting evidence. We investigated the prevalence of its use in tertiary neonatal units in Japan. A paper‐based survey was conducted. The response rate was 83%. High‐flow nasal cannula was used in 46/80 units (58%), of which 96% used the high‐flow nasal cannula without guidelines. It was used for several indications, including weaning off nasal continuous positive airway pressure and post‐extubation respiratory support. The main perceived benefits of the cannula included better access to the neonate and reduced risk of nasal trauma. This survey found that high‐flow nasal cannula is used without clear criteria and that clinical practice varies across neonatal units in Japan. Its use in neonates needs to be urgently evaluated.     

Clinical spectrum of epileptic spasms associated with cortical malformation.

The spectrum of clinico-electrical characteristics of epileptic spasms associated with cortical malformation was studied in detail. The subjects were 15 patients suffering from spasms and cortical malformation demonstrated by MRI. The types of cortical malformation causing spasms were various, including hemimegalencephaly, diffuse pachygyria, focal cortical dysplasia, and polymicrogyria. Ohtahara syndrome was diagnosed in 3 patients, and West syndrome in 8. Symptomatic localization-related epilepsy preceded West syndrome in 4 patients, and a transition from Ohtahara syndrome to West syndrome was observed in one. West syndrome was followed by symptomatic generalized epilepsy including Lennox-Gastaut syndrome in 4 patients. Nine patients showed a condition which was labeled "epilepsy with partial seizures and spasms" (EPS) and characterized by the coexistence of partial seizures and spasms, and multifocal epileptic discharges on EEG. Spasms occurred only as EPS in 5 patients. EPS appeared following Ohtahara syndrome or West syndrome in 4 patients, and showed a transition to symptomatic localization-related epilepsy in 4. However, EPS did not evolve into generalized epilepsy, and persisted until the time of last follow-up in 5 patients. Therefore, the clinico-electrical pictures of patients with spasms and cortical malformation were diverse and not always limited within those of typical generalized epilepsy.