Uptake of dehydroascorbic acid in high-GSH and normal-GSH dog erythrocytes

Uptake of dehydroascorbic acid (DHA) was studied in two types of dog erythrocytes with high GSH and normal GSH levels. Compared with ascorbic acid uptake, DHA produced a much greater ascorbic acid accumulation in dog erythrocytes. Both dog erythrocytes showed a concentration dependence of DHA uptake, and cellular ascorbic acid concentrations were significantly higher in high-GSH cells than in normal-GSH cells. Glucose and cytochalasin B inhibited DHA uptake. This suggests that DHA enters dog erythrocytes predominantly by the facilitated glucose transporter, particularly by the Glut 1 glucose transporter. The rate of glucose uptake was quite similar in the two types of cells. Compared with normal-GSH cells, high-GSH cells were more resistant to oxidative stress induced by high concentration of DHA. As a rapid entry of DHA inflicts on cells a heavy demand for GSH for its reduction to ascorbic acid, high-GSH cells containing a larger reserve of GSH have an advantage over normal-GSH cells in both ascorbic acid accumulation and resisting oxidative stress produced by DHA.     

Postoperative refractive error of secondary intraocular lens implantation after simultaneous vitrectomy and lensectomy.

To determine postoperative refractive errors of secondary intraocular lens (IOL) implantation, this study was performed in 42 eyes of 42 patients following secondary IOL implantation fixed in the sulcus after simultaneous vitrectomy and phacoemulsification and aspiration. Controls were 138 eyes of 124 patients with cataract who underwent phacoemulsification and aspiration and IOL implantation. The spread between expected and actual refraction (actual - expected) was -0.81 +/- 0.86 diopters (average +/- standard deviation) in the study group and 0.01 +/- 0.91 diopters in the control group (statistically significant, P < .001, Student's t test). The actual refractive errors in the study subjects were shifted toward myopia compared with the controls.     

Dermal fillers. The next generation.

In today's busy and demanding world, we no longer have the luxury of taking weeks to recover from a surgical procedure and are more frequently seeking quicker alternatives. The use of dermal fillers meets this need but in no way replaces a surgical intervention. Previously, bovine collagen was the only approved dermal filler. However, today there are several options available including a human collagen, a variety of hyaluronic acids, and a permanent injectable product. Each of the products has different uses, indications, and adverse reactions. The experienced injector now has a wider selection of products from which to choose to ensure that the patient receives what is best suited for his or her particular situation. These new products are becoming increasingly popular, due to acceptability and affordability, but are not without potential complications and adverse reactions. This article discusses the use of Cosmoderm/Cosmoplast, Hylaform, Restylane/Perlane, and Artecoll dermal fillers.     

Clinical usefulness of the frontal assessment battery (FAB) for elderly in memory clinic]

To investigate the usefulness of the frontal assessment battery (FAB) as a brief assessment for diagnosis in patients with dementia, we examined cognitive function using the FAB, Mini-mental state examination (MMSE), Kana-hiroi test, and Raven's colored progressive matrices (RCPM). Subjects were 82 senile patients having amnesia as a complaint including 28 Alzheimer's disease (AD), 14 frontotemporal dementia (FTD), 17 vascular dementia (VD), 13 mild cognitive impairment (MCI), and 10 healthy persons. We discussed the difference of scores in different types of dementia. In the FAB, the scores of healthy persons and MCI were much higher compared with the scores of all types of dementia. There were high correlation between FAB and MMSE, Kana-hiroi test, and RCPM. Although some subjects showed normal score in MMSE and/or RCPM, they showed low score in FAB. Based on this, FAB is efficient for the differential diagnosis of dementia as brief screening tool.     

Three human osteosarcoma cell lines exhibiting different phenotypic expressions.

to elucidate the differences in histological features and biological behavior of osteosarcomas, three human osteoblastic-type osteosarcomas were studied in vitro and in nude mice. The secretory processing and extracellular fiber formation of type I collagen proved to be the most important factor in bone formation in the osteosarcomas. Alkaline phosphatase also seemed to be important. However, we were unable to find any particular protooncogene abnormalities which could have been implicated in the occurrence or biological behavior of these osteosarcomas.     

Molecular biological study of the rhodopsin gene in Japanese patients with autosomal dominant retinitis pigmentosa]

The author analyzed codon 347 of the rhodopsin gene using PCR (polymerase chain reaction) amplification and restriction enzymes in 19 unrelated Japanese families including 28 patients with autosomal dominant retinitis pigmentosa (ADRP). An allele of codon 347 mutation was found in a family (father and daughter). Sequence analysis shows that the mutation is from CCG to CTG. This mutation appears to be the cause of one form of ADRP, since it was also found in Japanese cases of ADRP which have a different racial background from families reported by Dryja et al.     

Cerebellopontine angle ganglioneuroblastoma

Summary The CT, MR and histological features of a rare ganglioneuroblastoma of the cerebellopontine angle and cavernous sinus are reported.     

Dual concentration-dependent effects of phorbol 12, 13-dibutyrate on spontaneous and acetylcholine-induced electrical responses recorded from isolated circular smooth muscle of the guinea-pig stomach antrum.

Intracellular recordings of electrical activity were made from circular smooth muscle cells in small segments of tissue isolated from the guinea-pig stomach antrum. Every cell that was impaled exhibited a rhythmic generation of slow potentials. Experiments were carried out to test the effects of three different concentrations (1, 10 and 100 nM) of phorbol 12, 13-dibutyrate (PDBu) on these slow potentials and on the responses produced by acetylcholine (ACh), in the presence of nifedipine and N(omega)-nitro-L-arginine (nitroarginine), known inhibitors of L-type Ca-channels and nitric oxide synthase, respectively. The resting membrane potential was -62 +/- 7 mV, while the frequency and amplitude of the slow potentials were 1.6 +/- 0.1 cycle per min (cpm) and 33 +/- 1 mV, respectively. Application of 1 nM PDBu increased the frequency of slow potentials, with no significant change in the membrane potential and amplitude of slow potentials. At a concentration of 100 nM, PDBu depolarized the membrane by about 6 mV, and either decreased the amplitude and frequency of the slow potentials or abolished them. The amplitude and frequency of the slow potentials were not significantly changed in the presence of 10 nM PDBu. In the presence of chelerythrine (1-2 microM), a known inhibitor of protein kinase C (PKC), the increase in frequency of slow potentials by 1 nM PDBu and depolarization produced by 100 nM PDBu were not elicited. The increase in frequency of slow potentials by 100 nM ACh was inhibited by PDBu, in a concentration-dependent manner, and ACh-responses were abolished in the presence of 100 nM PDBu. These results indicate that PDBu has dual actions on the spontaneous activity of antral circular muscle, with low concentrations increasing and high concentrations inhibiting the frequency of the slow potentials. The former may be produced by activation of protein kinase C (PKC). As the ACh-induced excitation of slow potentials is inhibited by PDBu, a possible causal relationship between the inhibition and over-activation of PKC is considered.     

Genomic structure around joining segments and constant regions of swine T-cell receptor alpha/delta (TRA/TRD) locus

A complete genomic region of 131.2 kb including the swine T-cell receptor alpha/delta constant region (TRAC/TRDC) and joining segments (TRAJ/TRDJ) was sequenced. The structure of this region was strikingly conserved in comparison to that of human or mouse. All of the 61 TRAJ segments detected in the human genomic sequence were detected in the swine sequence and the sequence of the protein binding site of T early alpha, the sequence of the alpha enhancer element and the conserved sequence block between TRAJ3 and TRAJ4 are highly conserved. Insertion of the repetitive sequences that interspersed after the differentiation of the species in mammals such as short interspersed nucleotide elements is markedly suppressed in comparison to other genomic regions, while the composition of the mammalian-wide interspersed sequences is relatively conserved in human and swine. This observation indicates the existence of a highly selective pressure to conserve this genomic region around TRAJ throughout the evolution of mammals.