Comparative analysis of functional and structural features in the primase-dependent priming signals, G sites, from phages and plasmids

The primase-dependent priming signals, G sites, are directly recognized by the Escherichia coli primase (dnaG gene product) and conduct the synthesis of primer RNAs. In nucleotide sequence and secondary structure, there is no striking resemblance between the phage- and plasmid-derived G sites, except for the limited sequence homology near the start position of primer RNA synthesis. In this study, we analyzed the structure and function of a G site of plasmid R100, G site (R100), and discovered the necessity of the coexistence of two domains (domains I and III), which contains blocks A, B, and C, which are nucleotide sequences highly conserved among the plasmid-derived G sites. However, neither the internal region, domain II, between domains I and III nor the potential secondary structure proposed by Bahk et al. (J. D. Bahk, N. Kioka, H. Sakai, and T. Komano, Plasmid 20:266-270, 1988) is essential for single-stranded DNA initiation activity. Furthermore, chimeric G sites constructed between a G site of phage G4, G site(G4), and G site(R100) maintained significant single-stranded DNA initiation activities. These results strongly suggest that phage- and plasmid-derived G sites have functionally equivalent domains. The primase-dependent priming mechanisms of phage- and plasmid-derived G sites are discussed.

Age-related increase in collagen production in cultured human osteoblast-like periosteal cells

Since collagen synthesis is a primary function of differentiated osteoblasts, we investigated the age-related changes in hydroxyproline content, procollagen mRNA level, collagenase activity and collagenase inhibitory activity in human osteoblast-like periosteal cell (OP cell) cultures established from donors of various ages. After achieving confluent growth, the OP cells were treated with 10(-8) M 1,25(OH)2 vitamin D3 in the presence of 2 mM alpha-glycerophosphate for 10 days to facilitate osteoblast differentiation. Hydroxyproline content of the treated cells increased with donor age. But pro alpha 1(I) collagen mRNA level increased until a donor age of 65, and decreased thereafter with increasing door age. Collagenase activity was not detected in cell extracts or the conditioned medium concentrated more than 10 times. However, OP cells had collagenase inhibitory activity which was five times higher in cells from aged donors than in cells from young donors. It is possible that cells from elderly donors accumulated much more collagen than cells from younger donors by inhibiting collagen degradation.

In vitro phagocytosis of polylactide microspheres by retinal pigment epithelial cells and intracellular drug release

We investigated phagocytosis of biodegradable microspheres containing a drug by retinal pigment epithelial (RPE) cells and drug release within the cells to evaluate the potential usefulness of microspheres for intracellular drug delivery. The biodegradable polymers used were L-lactic acid, and DL-lactic acid with different molecular weights or the copolymers of different monomer compositions. The microspheres containing a non-bioactive fluorescent dye (rhodamine 6GX) as a model drug, were prepared by a solvent evaporation method. The in vitro release of the dye from the microspheres was examined. Phagocytosis of the microspheres by RPE cells was conducted to evaluate the extent of phagocytosis by phase-contrast microscopy and transmission electron microscopy. The RPE cells ingesting the microspheres at different stages were examined by fluorescent microscopy to estimate the intracellular release of the dye. The dye was released with time from every microsphere and the release was controlled by changing the type of polymers constituting microspheres. The microspheres containing the dye were phagocytosed by RPE cells and the dye was released intracellularly with time. The present study indicates that the drug incorporated in the microspheres was delivered into RPE cells by way of phagocytosis and released within the cells. It is concluded that this microsphere system is a promising delivery form capable of drug targeting to RPE cells.

A new vitreal drug delivery system using an implantable biodegradable polymeric device

PURPOSE

The authors evaluated the feasibility of using an implantable biodegradable polymeric device to deliver drugs into the vitreous humor.

METHODS

Two types of devices were prepared by compression-molding polymers of poly(DL-lactic acid) of two different molecular weights. The molecular weights of the poly(DL-lactic acid) used were 5,600 (device-1) and 9,100 (device-2). Sodium fluorescein (NaF) served as a hydrophilic drug marker. The release of the dye from the devices was studied in vitro. The intravitreal kinetics of NaF was evaluated in rabbits in vivo by fluorophotometry. The eyes were evaluated electrophysiologically and histologically to determine if there were toxic effects.

RESULTS

Device-1 and device-2 released NaF for more than 25 and 45 days, respectively, in vitro. Detectable concentrations of NaF were present in the vitreous up to 17 days (device-1) and 28 days (device-2). Both types of devices were well tolerated, with no noted toxic effects.

CONCLUSIONS

These results suggested that this device may be a potentially effective system to deliver drugs in the vitreous.

Effect of ribavirin on subacute sclerosing panencephalitis virus infections in hamsters

The antiviral activity of ribavirin was studied in hamsters infected with subacute sclerosing panencephalitis (SSPE) virus. Ribavirn did not improve the survival of infected hamsters when administered intraperitoneally at the maximal nonlethal dose of 50 mg/kg/day for 10 days. However, when administered intracranially, ribavirin improved the survival of infected hamsters in a dose-dependent manner. The 50% effective dose was calculated to be 1.4 mg/kg/day, and the selectivity index, based on the ratio of the 50% lethally toxic dose (31 mg/kg/day) to the 50% effective dose, was 22. When begun 12 h, but not 36 h, postinfection, ribavirin at a dose of 10 mg/kg/day completely prevented mortality and inhibited the replication of SSPE virus in brains of infected hamsters. Intrathecal or intraventricular administration of ribavirin should be explored for potential use in the treatment of patients with SSPE.

Catalytic nature of tyrosine hydroxylase in bovine ocular tissues

We performed a comparative study on tyrosine hydroxylase (TH), a rate-limiting enzyme in catecholamine biosynthesis, in two ocular tissues, the retina and the iris-ciliary body. Immunoblotting analysis and gel filtration study suggested no significant difference in their subunit structure and their oligomeric form. The optimal pH of TH was 6.0 in retina and 6.3 in iris-ciliary body. However, at the physiological pH (7.25), the retinal TH had only 15% of the maximum activity while TH in the iris-ciliary body had 70% of the maximum activity. In hydroxylapatite chromatography, both extracts showed different elution profiles; the major TH activity in retina appeared earlier (200 mM, phosphate concentration) than that in iris-ciliary body (300 mM). When these enzymes were phosphorylated by catalytic subunit of cAMP-dependent protein kinase, most of the activity shifted to the later peak in both enzymes. Also, the activity of dephosphorylated TH in iris-ciliary body shifted to the earlier peaks. These results indicate that native TH in retina is basically less phosphorylated and thus exists in a less activated form than that in iris-ciliary body.

Functional difference between the two oppositely oriented priming signals essential for the initiation of the broad host-range plasmid RSF1010 DNA replication

The broad host-range plasmid RSF1010 contains two oppositely oriented priming signals, ssiA and ssiB, for DNA synthesis dependent on the origin of vegetative DNA replication (oriV). If either ssiA or ssiB was deleted or inverted, the RSF1010 miniplasmids containing engineered oriVs were maintained at low copy numbers, replicated abnormally as dimers, and accumulated specific single strands in the Escherichia coli strain supplying the three RSF1010-encoded RepA, RepB', and RepC proteins. Interestingly, an additional intracellular supply of the Sog primase (the sog gene product of plasmid CoIIb-P9) reversed the replication deficiency of these miniplasmids with respect to all three aspects described above. These were also true for the RSF1010 miniplasmids in which either ssiA or ssiB was replaced by the primosome assembly site (PAS) or by the G4-type ssi signal (G site). Furthermore, comparative analysis of the functional contribution of the two oppositely oriented ssi signals to the DNA replication of RSF1010 showed that, irrespective of their types, ssi signals conducting the initiation of DNA chain elongation away from the iterons were functionally more important than ones in the inverted orientation. We consider that this functional difference reflects the inherent properties of the initiation mechanism of RSF1010 DNA replication.

Feasibility of drug targeting to the retinal pigment epithelium with biodegradable microspheres

There are several systems of delivering drugs to cells with phagocytic activity. We studied the possibility of targeting drugs to retinal pigment epithelial (RPE) cells with the use of surface-modified microspheres. A fluorescent dye, 1,4-bis[2-(5-phenyloxazolyl)]-benzene (POPOP), was incorporated into microspheres of poly(lactic acid) for use as a marker to evaluate drug delivery. Phagocytosis of the microspheres, with or without gelatin precoating, was carried out at 37 degrees C and 4 degrees C. The cell-incorporated fluorescence of POPOP was measured, and scanning electron microscopy was used to confirm phagocytosis. At 4 degrees C, no uptake of POPOP was noted; however at 37 degrees C, cell-associated fluorescence was observed to increase for up to 24 hr. In comparison with bare microspheres, gelatin precoating significantly enhanced phagocytosis (P < 0.001) at the same incubation times. These results suggested that drug delivery to RPE cells may be feasible by means of surface-modified polymer microspheres.

Interleukin-1 alpha, interleukin-1 beta, and tumor necrosis factor gene expression in endotoxin-induced uveitis

PURPOSE

To localize and determine the levels of interleukin-1 alpha (IL-1 alpha), interleukin-1 beta (IL-1 beta), and tumor necrosis factor (TNF) gene expression in the process of endotoxin-induced uveitis (EIU) in rats.

METHOD

EIU was induced by lipopolysaccharide (LPS) injection in male Lewis rats weighing 150 to 200 g. The levels of IL-1 alpha, IL-1 beta, and TNF gene expression in the iris-ciliary body (ICB) were quantified by a semiquantitative polymerase chain reaction (PCR) method; in situ hybridization histochemistry was carried out to localize the gene transcripts.

RESULTS

Little expression of IL-1 alpha, IL-1 beta, and TNF genes was observed in normal ICB. IL-1 alpha gene expression began to increase (about 10-fold greater than that of the control) as early as 1 hour after the LPS treatment, reached a peak (about 100-fold) at 3 to 6 hours. A second peak (60-fold) was observed at 24 hours, and the expression returned to near basal levels (3-fold) at 48 hours. Expression of IL-1 beta and TNF genes showed a pattern similar to that of IL-1 alpha. Three hours after LPS treatment, IL-1 beta and TNF genes were found by in situ hybridization histochemistry to be expressed by "histiocyte-like" cells in the stroma of the ICB. None of these genes were detected in the control rats.

CONCLUSIONS

Expression of IL-1 alpha, IL-1 beta, and TNF genes was dramatically up-regulated in the process of EIU. These genes were found to be expressed in "histiocyte-like" cells in the ICB, and may have an important role in EIU.

Pharmacokinetics and pharmacodynamics of (+)-threo-methylphenidate enantiomer in patients with hypersomnia

The pharmacokinetics of (+)-methylphenidate after oral administration of 20 mg racemic methylphenidate hydrochloride and the relationship between clinical effects of plasma (+)-methylphenidate concentration were investigated in 15 patients with hypersomnia and four healthy volunteers. The elimination half-life of (+)-methylphenidate in patients was within the range of 2.6 to 3 hours, and the time to reach the peak concentration ranged from 1 to 3 hours. The values of half-life and time to reach the peak concentration in the patients were almost the same as the values in healthy subjects. The plasma (+)-methylphenidate concentration profiles after repeated administration of racemic methylphenidate were similar to those after single administration. No correlation was observed between the plasma (+)-methylphenidate concentration and the subjective sleepiness as measured by Stanford Sleepiness Scale. On the other hand, a significant correlation was found between the sleep latency as measured by the multiple sleep latency test and the plasma concentrations of (+)-methylphenidate (r = 0.850). The time course of the sleep latency after repeated administration was similar to that after single administration. The sleep latency of more than 10 minutes was achieved by maintaining the plasma (+)-methylphenidate concentrations above 3 ng/ml.

Ferromagnetic hyperthermia in rabbit eyes using a new glass-ceramic thermoseed

Hyperthermia is a new treatment modality to increase the tumoricidal effect of radiotherapy for choroidal melanoma. We have produced a ferromagnetic glass-ceramic composed of magnetite and wollastonite as a thermoseed for interstitial hyperthermia. The stable oxidized ceramic produced sufficient heat by hysteresis loss upon exposure to an alternating magnetic field. We studied its heat-generating properties and evaluated its possible application to ocular hyperthermia. Agar model and rabbit eye studies showed that the heat generated by the ceramic was less affected by its orientation in the magnetic field than metal alloy thermoseeds and that the retinal surface was heated to 43.5 degrees C in less than 7 min without heating the surrounding tissue. Additionally, this heating system showed a good temperature stability of +/- 0.1 degrees C under steady-state conditions without using a controller. The new glass-ceramic shows promise as a thermoseed in ocular hyperthermia.

Insulin-like growth factor-related genes, receptors, and binding proteins in cultured human retinal pigment epithelial cells

PURPOSE

It was determined in cultured human retinal pigment epithelial (HRPE) cells whether there is gene expression for insulin, insulin-like growth factors (IGFs), insulin and IGF receptors, and IGF-binding proteins (IGFBPs); if these peptides are secreted by the HRPE cells, and whether they have mitogenic effects on these cells; and if IGF-related peptides bind to HRPE cells.

METHODS

Reverse transcriptase-polymerase chain reaction (RT-PCR), nucleotide sequencing, and Southern blot analyses were done to identify gene expression. The presence of IGFs in the tissue culture medium was detected by radioimmunoassay. For determination of mitogenic effects and receptor binding characterization, [3H]-thymidine incorporation and radioreceptor binding measurements were performed.

RESULTS

The genes for IGF-I and IGF-II, IGFBP-2, insulin receptor, and type I and II IGF receptors were detected. In the tissue culture supernatant, there was immunoreactivity for IGF-I and IGF-II. Insulin, IGF-I, and IGF-II stimulated DNA synthesis with EC50s of 3, 10, and 30 to 100 nM, respectively. Scatchard analyses of [125I]-IGF-I binding and [125I]-insulin binding to the cells showed that the cells have relatively abundant insulin and IGF-I binding sites.

CONCLUSIONS

HRPE cells express genes for IGF-I and IGF-II, and conditioned medium from these cells is immunoreactive to their protein products. The cells express genes for insulin receptor, type I and II IGF receptors, and IGFBP-2. IGF-I, IGF-II, and insulin are all mitogenic, possibly as a result of their interactions with either the insulin or type I IGF receptor. The cells bind insulin and IGF-I with high affinity. These results suggest that IGF-I and IGF-II production by HRPE cells may be essential for autocrine/paracrine-mediated regulation of proliferation. The presence of insulin receptor suggests that insulin has a role in the regulation of HRPE function.

Functional features of oriV of the broad host range plasmid RSF1010 in Pseudomonas aeruginosa

The broad host range plasmid RSF1010 requires for its replication in Escherichia coli three plasmid-encoded proteins and specific nucleotide sequences ssiA, ssiB, and iterons in the oriVRSF1010. In Pseudomonas aeruginosa, a recombinant mini-RSF1010 plasmid lacking ssiB lost its replication ability, but a miniplasmid lacking ssiA or carrying a primosome assembly site in place of ssiA could replicate. Moreover, ssiA, as a sole ssi signal, in the orientation that ssiB had originally taken was sufficient for replication of the miniplasmid. These results indicated that only one RSF1010-specific ssi signal in the orientation that ssiB takes in wild-type oriVRSF1010 was essential for replication of RSF1010. Replication of the miniplasmids was dependent on the three plasmid-encoded proteins, RepA, B', and C, as in E. coli.

Oxidative stress induces adult T cell leukemia derived factor/thioredoxin in the rat retina

BACKGROUND

Adult T cell leukemia derived factor (ADF), originally defined as an interleukin-2 receptor inducer, is a human thioredoxin homolog. ADF/thioredoxin has several biologic functions, such as defense against cellular damage, activity to scavenge oxidative stress by hydrogen peroxide radicals and cytokine-like properties. We hypothesized that under certain conditions, ischemia followed by reperfusion and/or light exposure, ADF may be induced in the retina.

EXPERIMENTAL DESIGN

To test this hypothesis, we prepared experimental animal models in which oxidative stress could be applied to the retina. In the present study, we examined ADF expression in the rat retina using temporary ischemia and reperfusion, and photodynamic retinal vascular thrombosis by immunohistochemical and Western blotting methods.

RESULTS

ADF expression was strongly induced in the retinal pigment epithelial cells after 2 hours of ischemia followed by 2, 24, or 48 hours of reperfusion. ADF was also expressed in retinal pigment epithelial cells as early as 3 hours after light exposure followed by rose bengal injection, and this expression increased with time. Western blotting data showed that ADF expression increased in the retinal pigment epithelial cells in the experimental group, as compared with the control group. These results indicate that ADF is actively induced in retinal pigment epithelial cells upon oxidative stress.

CONCLUSIONS

ADF induction in retinal pigment epithelial cells may be involved in the defense mechanism against cellular damage caused by active oxygen species generated during oxygen stress to the retina.

Protective action of dopamine against glutamate neurotoxicity in the retina

PURPOSE

The electrophysiologic study using patch-clamp techniques demonstrated that NMDA-induced currents had properties similar to those recorded in the brain.

METHODS

Primary cultures obtained from the fetal rat retina (gestation days 16 to 19) were used for the experiment. Immunocytochemical and electrophysiologic studies were done to identify the cultured cells. The neurotoxic effects of glutamate or N-methyl-D-aspartate (NMDA) on the retinal cultures were quantitatively assessed using the trypan blue exclusion method.

RESULTS

The immunocytochemical study revealed that the major component of the rat retinal cultures was neurons including amacrine cells. The electrophysiologic study using patch-clamp techniques demonstrated that exposure to NMDA-induced currents with properties characteristic of those recorded in the brain. Brief exposure of these neurons to glutamate or NMDA induced delayed cell death. Glutamate neurotoxicity was prevented by the application of dopamine and forskolin. The protective action of dopamine was antagonized by a D1 receptor antagonist (SCH 23390) but not by D2 receptor antagonists (domperidone and sulpiride). A D1 receptor agonist (SKF 38393) protected glutamate-induced neurotoxicity in a concentration-dependent manner, whereas a D2 receptor agonist (quinpirole) did not affect it.

CONCLUSIONS

These findings demonstrate that dopamine protects retinal neuronal cells against NMDA receptor-mediated glutamate neurotoxicity via D1 receptors.

Intraretinal study of cat electroretinogram during retinal ischemia-reperfusion with extracellular K+ concentration microelectrodes

PURPOSE

Intraretinal electroretinograms (ERG) during retinal ischemia-reperfusion were analyzed to clarify which cells are affected in the cat dark-adapted eye.

METHODS

Ischemia was induced by raising the intraocular pressure above arterial systolic pressure in vivo. Double-barreled microelectrodes were used to record the intraretinal ERGs and the light-evoked [K+]o decrease in the subretinal space. Vitreal ERGs, the standing potential and the transepithelial resistance were also recorded.

RESULTS

After 10 minutes of ischemia, vitreal ERG b- and c-waves had recovered fully in 2 hours, and after 30 minutes of ischemia, recovered approximately 85% and 77% of their control amplitudes in 4 hours, respectively. At the early period of reperfusion after 10 minutes of ischemia we observed the supernormal c-wave (124% of its control amplitude, n = 10) with an elevated standing potential. The transepithelial potential (TEP) c-wave increased without changes of slow PIII and transepithelial resistance when the supernormal amplitudes occurred. The light-evoked [K+]o decrease in the subretinal space (90% retinal depth) in the area centralis recovered to about 90% of the control amplitude in 2 hours, and after 30 minutes of ischemia recovered to about 70% of the control amplitudes in 4 hours. The recovery courses of the slow PIII and TEP c-wave were almost the same as that of the light-evoked [K+]o decrease.

CONCLUSIONS

The temporary supernormal amplitude of the ERG c-wave was originated from the retinal pigment epithelium (RPE) during the early period of reperfusion after 10 minutes of ischemia. The photoreceptors, Muller cell and RPE are responsible for the changes in the light-evoked [K+]o decrease, a slow PIII and TEP c-wave, respectively. Intraretinal recordings suggested that after ischemia of 10 to 30 minutes duration, the responses of photoreceptors, Muller cells and the RPE recovered with a similar time course. These findings suggest that in all cases, primarily photoreceptors were damaged.

Differences in the response of genioglossal muscle activity to sustained hypoxia between healthy subjects and patients with obstructive sleep apnea

The depression of EMG activity in upper airway muscles during sleep is known to be a predisposing factor causing upper airway obstruction in patients with obstructive sleep apnea syndrome (OSAS). To clarify whether or not the selective depression of upper airway muscles could be associated with the hypoxic ventilatory depression, we performed sustained hypercapnic hypoxia tests during wakefulness in 11 control subjects and 10 patients with OSAS. Isocapnic sustained hypoxia around SaO2 80% with mild hypercapnia [PETO2: 45.8 +/- 1.6 (SD) and 46.7 +/- 2.8 mm Hg and PETCO2: 44.2 +/- 4.7 and 43.1 +/- 5.0 mm Hg in control and OSAS groups, respectively] was applied for 20 min. Electromyogram activities were recorded from the genioglossal muscle (EMGGG) and diaphragm (EMGDIA) with ventilatory variables. The magnitudes of hypoxic depression in terms of minute ventilation (VI) and minute EMGDIA (EMGDIA/min) were compared in percentage between peak value and the value at the late period. These values were not significantly different between two groups (VI: 79.2 +/- 10.7 and 66.9 +/- 12.8% and EMGDIA/min: 63.2 +/- 17.1 and 60.4 +/- 24.0% in control and OSAS, respectively). On the contrary, the depression in EMGGG was not consistently observed in control (86.1 +/- 38.6% of the peak value) whereas EMGGG was markedly depressed in OSAS (38.6 +/- 15.7% of the peak value; p < 0.01). It is concluded that sustained hypoxia attenuates the activity in genioglossal muscle in patients with OSAS, but not in control subjects.(ABSTRACT TRUNCATED AT 250 WORDS)

Soluble intercellular adhesion molecule-1 (ICAM-1) in sera and bronchoalveolar lavage fluid of patients with idiopathic pulmonary fibrosis and pulmonary sarcoidosis

ICAM-1 plays an important role in inflammatory diseases. To assess level of soluble ICAM-1 in the circulation and inflamed lesions, we measured levels of soluble ICAM-1 in the circulation and bronchoalveolar lavage fluid (BALF) of patients with idiopathic pulmonary fibrosis (IPF) and with pulmonary sarcoidosis (PS) and of healthy volunteers (HV), and we also analysed ICAM-1 expression of BALF cells in some patients and HV. IPF patients had significantly higher levels of circulating ICAM-1 than HV, while PS patients did not. By contrast, significantly increased levels of BALF soluble ICAM-1 were found in PS patients compared with those of HV, but not in IPF patients. There were no significant differences in the proportions of ICAM-1+ BALF lymphocytes in IPF patients, PS patients and HV, whereas significantly increased proportions of ICAM-1+ pulmonary alveolar macrophages were found in PS patients compared with those of HV, but not in IPF patients. There was a significant positive correlation of BALF soluble ICAM-1 levels to BALF lymphocyte proportions in PS patients. Although the source of BALF soluble ICAM-1 is unclear, BALF soluble ICAM-1 appears to reflect the grade of local activity of sarcoidosis. An interesting discrepancy between soluble ICAM-1 levels in the circulation and BALF was found in IPF patients, and this might be an important clue to an understanding of this disorder.

A seroepidemiological study of hepatitis C virus (HCV) in an area with a high prevalence of chronic liver disease in the Kyushu district of Japan

The incidence of hepatitis virus type C (HCV) in an area, Futase, of Iizuka city in Chikuho province in the northeastern part of Fukuoka prefecture in Kyushu, Japan, was estimated by screening sera for anti-HCV antibodies. Titers of anti human T-lymphotropic virus type I (HTLV-I) antibodies and hepatitis virus type B surface antigens (HBs) were also determined. The area of the present study is known to have a particularly high prevalence of chronic liver diseases, because coal mining was the key industry until a few decades ago. Also, in the old days it was rather isolated from the neighboring vicinities by surrounding mountains. The subjects of the present survey were 310 patients (117 males and 193 females) with various chronic diseases who visited Futase Social Insurance Hospital during a two year period from 1991 to 1992. Anti-HCV antibodies were detected in the sera of 55 patients, which is an overall positive rate of 18% (26% in male and 14% in female patients). This is extremely high compared to an estimated nationwide average positive rate of 1.6%. Even in 270 patients with normal liver function, the incidence was as high as 10%. The incidences were particularly high in groups of patients aged 40 through 49, 50 through 59 and 60 through 69, ranging from 20 to 23%, while they were as low as 13 and 17% in those aged 70 through 79 and 80 through 89 years, respectively. A high incidence, 57% was estimated for the patients with impaired liver function due to chronic liver diseases, especially in those concomitantly having diabetes mellitus (DM), 91%. The incidence of anti-HCV antibodies was the highest, 100%, in patients having both liver cirrhosis (LC) and DM. This was followed by those having chronic hepatitis (CH) and DM concomitantly and by those with LC alone, 86% each, and by those with CH alone 44%. Furthermore, the genotypes of the HCV in the sera of nine randomly selected carrier patients who had anti-HCV antibodies, even though they had diseases other than hepatic diseases and their liver functions were normal, were examined by the polymerase chain reaction method employing type-specific primers for DNA amplification. As a result, all the HCV strains were type II. On the other hand, there were no apparent differences in the incidences of HTLV-I in the area of the present study and in neighboring provinces of the same prefecture, Fukuoka.(ABSTRACT TRUNCATED AT 400 WORDS)

Phagocytic ability of polymorphonuclear cells and macrophage is not decreased in aged bed ridden patients

The phagocytic ability of polymorphonuclear cells and macrophages from aged, bed ridden patients was investigated. Phagocytosis of carbon in aged bed ridden patients did not differ from that of young controls, and extent of upregulation of granulocytes phagocytosis in response to elevation of incubation temperature was also similar between the two groups. Morphological changes of macrophages in response to ingestion of colloidal carbon was more prominent in young controls. These data suggest that a depressed phagocytosis is not an important factor in the increased susceptibility to infections of aged bed ridden patients, although the reactivity of macrophages may be more closely related to the infection defence.

Effects of intravenous superoxide dismutase and catalase on electroretinogram in the cat postischemic retina

We examined the effects of the antioxidant enzymes, 10,000 U/kg of superoxide dismutase (SOD) and 50,000 U/kg of catalase (CAT) on cat electroretinograms during the reperfusion after retinal ischemia. The intravenous administrations of SOD and CAT promoted the recovery of the c-wave after 30 min of ischemia but not the b-wave. At 5 min after onset of reperfusion, SOD- and CAT-treated eyes showed 90 and 110% recovery of the c-wave amplitude respectively, against 50% recovery in the untreated eyes. These results suggested that the oxygen-derived free radicals affected the retinal pigment epithelium at the early period of reperfusion.