Optical Properties of HDPE in Injection Molding and Injection Press Molding for IR System Lenses Part II: Mold Temperature and Surface Roughness Effects on Injection Molding

An experimental investigation of injection molding was conducted to assess the high infrared radiation (IR) transmittance with an opaque state (low visibility ray (VR) transmittance) necessary for IR system lenses as a target high-density polyethylene (HDPE) IR transmission material. In our earlier investigation, experimental investigations of injection molding and injection press molding were conducted using the mold cavity of a disk-shaped finished mirror-like surface. For high mold temperature and long cooling time, the increased core-layer thickness improved the IR transmittance. Simultaneously, the VR transmittance decreased because the crystallinity became higher. Furthermore, when injection press molding was done, the VR transmittance decreased because the crystallinity increased. Using a 0.5-mm-thick mold cavity with disk shapes having different surface roughness, an injection molding experiment was conducted for this study while changing only the mold temperature of 20 to 80°C. Results show that when the mold surface roughness became high, the surface roughness of molded parts became high, too. Thereby the IR and VR transmittance were decreased. However, when the mold temperature was high, the influences of the so-called skin-core structure and crystallinity were stronger than the influence of the surface roughness of molded parts. The IR transmittance increased because of the decrease of the skin layer. Furthermore, the VR transmittance decreased because of a simultaneous rise of the crystallinity. The minimum value of obtained VR transmittance was 9.3% at mold temperature of 80°C using a mold of the highest surface roughness. This molded part reached an opaque state. Furthermore, a higher IR transmittance of 64.9% was obtained. When injection molding was conducted using a mold of a mirror-like surface with the same conditions as those in this investigation in our earlier investigation, the obtained IR and VR transmittances were 65.4% and 0.6%, respectively. Consequently, when the mold temperature was high, a few differences were found with transmittance of the molded parts using the mold of the mirror-like surface. Results showed that no difficulty arises when a mold having higher surface roughness is used at a higher mold temperature.

Optical Properties of HDPE in Injection Molding and Injection Press Molding for IR System Lenses

To obtain the “high infrared radiation (IR) transmittance and low visible ray (VR) transmittance” necessary for a high-performance IR lens, cavity thickness and molding conditions were investigated experimentally for disk-shaped high-density polyethylene (HDPE). When injection molding and injection press molding were done using different cavity thicknesses, results showed that the molded part using the thinner cavity thickness maintained a semitransparent state. Simultaneously, they showed that higher IR transmittance was obtained. For high mold temperature and long cooling time, the increased core-layer thickness improved the IR transmittance. The VR transmittance decreased because crystallinity became higher. Furthermore, when injection press molding was conducted, the VR transmittance decreased because crystallinity became higher. IR transmittance and VR transmittance were obtained respectively as 65.4% and 6.4% when injection press molding was conducted at higher mold temperatures with longer cooling times.

A genomic analysis of adult T-cell leukemia

Adult T-cell leukemia (ATL) is an intractable malignancy of CD4+ T cells that is etiologically associated with infection by human T-cell leukemia virus-type I. Most individuals in the chronic stage of ATL eventually undergo progression to a highly aggressive acute stage. To clarify the mechanism responsible for this stage progression, we isolated CD4+ cells from individuals in the chronic (n=19) or acute (n=22) stages of ATL and subjected them to profiling of gene expression with DNA microarrays containing >44,000 probe sets. Changes in chromosome copy number were also examined for 24 cell specimens with the use of microarrays harboring approximately 50,000 probe sets. Stage-dependent changes in gene expression profile and chromosome copy number were apparent. Furthermore, expression of the gene for MET, a receptor tyrosine kinase for hepatocyte growth factor (HGF), was shown to be specific to the acute stage of ATL, and the plasma concentration of HGF was increased in individuals in either the acute or chronic stage. HGF induced proliferation of a MET-positive ATL cell line, and this effect was blocked by antibodies to HGF. The HGF-MET signaling pathway is thus a potential therapeutic target for ATL.

Epigenetic silencing of AXIN2 in colorectal carcinoma with microsatellite instability

Mutation or epigenetic silencing of mismatch repair genes, such as MLH1 and MSH2, results in microsatellite instability (MSI) in the genome of a subset of colorectal carcinomas (CRCs). However, little is yet known of genes that directly contribute to tumor formation in such cancers. To characterize MSI-dependent changes in gene expression, we have now compared transcriptomes between fresh CRC specimens positive or negative for MSI (n=10 for each) with the use of high-density oligonucleotide microarrays harboring >44,000 probe sets. Correspondence analysis of the expression patterns of isolated MSI-associated genes revealed that the transcriptome of MSI+ CRCs is clearly distinct from that of MSI- CRCs. Such MSI-associated genes included that for AXIN2, an important component of the WNT signaling pathway. AXIN2 was silenced, apparently as a result of extensive methylation of its promoter region, specifically in MSI+ CRC specimens. Forced expression of AXIN2, either by treatment with 5'-azacytidine or by transfection with AXIN2 cDNA, resulted in rapid cell death in an MSI+ CRC cell line. These data indicate that epigenetic silencing of AXIN2 is specifically associated with carcinogenesis in MSI+ CRCs.

An unusual case of rhythmic movement disorder

Rhythmic movement disorder is one of the sleep-wake transition disorders listed in the International Classification of Sleep Disorders. According to this classification, the condition commonly occurs in infants and toddlers, and persistence beyond 4 years of age is unusual. Recently, we encountered a case in which rhythmic movement disorder persisted up until the age of 12 years with spikes registering on the sleep electroencephalogram. Epileptic seizure was ruled out because of the characteristic rolling movement, absence of any other epileptic symptoms (e.g. vocalization and tonic-clonic seizure) and cessation as a result of removal of the blanket.

Epworth Sleepiness Scale and sleep studies in patients with obstructive sleep apnea syndrome

Excessive daytime sleepiness (EDS) is the major symptom of patients with obstructive sleep apnea syndrome (OSAS). In this study, we examined the relationship between subjective EDS scored with the Epworth Sleepiness Scale (ESS), objective EDS measured with the multiple sleep latency test (MSLT) and sleep variables evaluated with polysomnography for patients with OSAS. Subjects were 10 patients (51.7+/-19.0 years old). The average ESS and MSLT scores were 10.6+/-5.6 and 7.7+/-5.6, respectively. There was no significant relationship between ESS and MSLT. The Multiple Sleep Latency Test had a significant negative relationship with the number of awakenings and the apnea/hypopnea index. No relationship was found between nocturnal hypoxia and either ESS or MSLT. Our findings suggest that objective EDS in OSAS is related with fragmentation of sleep, and that several patients are not aware of their EDS.

Polysomnographic and urodynamic changes in a case of obstructive sleep apnea syndrome with enuresis

A 53-year-old female patient with obstructive sleep apnea syndrome was reported. She had complained of enuresis as well as a 15-year history of snoring, but she had no complaint of sleep and awake disturbance. Polysomnographic study showed repeated obstructive apnea and hypopnea with an apnea/hypopnea index of 52.6, and severe oxygen desaturation during sleep. On cystometography during sleep, the changing amplitude of the spike wave corresponds to the changes of respiratory efforts against a closed upper airway. The patient was treated successfully with imipramine and acetazolamide for the obstructive sleep apnea and enuresis. Apnea/hypopnea index, nocturnal oxygen desaturation, and sleep architecture were improved, and enuresis completely disappeared. Cystometrography during sleep showed that the average amplitude of the spike wave tended to be low. Percentage urinary volume during sleep compared with 24 h volume was significantly reduced. We considered that the enuresis was mainly related to increased intra-abdominal pressure produced by respiratory efforts and enhanced nocturnal urine production.

Changes in work performances in obstructive sleep apnea patients after dental appliance therapy

The effects of dental appliances on work performances of obstructive sleep apnea syndrome (OSAS) is not well examined. This study evaluated the polysomnographic and psychological findings before and after therapy. Nine patients were diagnosed OSAS by nocturnal polysomnography. The psychological batter, was performed from 13:00 to 14:00, which consisted of Uchida-Kraepelin psychodiagnostic test (U-K's test) and Bourdon's cancellation test (Bourdon's test). Approximately 3 months after the treatment, the examinations were performed. Apnea and desaturation index decreased significantly after the therapy. In addition, sleep architecture improved after the therapy compared with that before the therapy. Dysfunction of task performances, such as mean level of work amounts in U-K's test, mean error, mean performance time and mean deviation in Bourdon's test improved after therapy. We conclude that dental appliances therapy is effective not only to apnea but also to work performance in OSAS.

Selective antigen presenting activity of cortical thymic epithelial cells against CD4+ T cells associated with both lack of costimulatory molecules and inefficient presentation of MHC-peptide ligands

Selective activation among several effector functions of a T cell clone, DB14, specific for pigeon cytochrome c 43-58 (p43-58) and restricted to I-Ab/d was induced by antigen (Ag) presentation with nonprofessional Ag-presenting cells (APC), cortical thymic epithelial cells (c-TEC) (B7-1- CD40-), whereas full activation of the DB14 was induced with another nonprofessional APC, I-Ab L cell (B7-1+ CD40+). In the present study, to elucidate the mechanism underlying the selective activation of DB14 cells by c-TEC, we established c-TEC transfected with human CD40 alone (huCD40-c-TEC) or both human CD40 and murine B7-1 (huCD40/mB7-1-c-TEC), and compared the APC functions with those of the original c-TEC and I-Ab L cell. IFN-gamma production but not the proliferative response of DB14 was elevated by Ag presentation with huCD40-c-TEC as compared with unmanipulated c-TEC. On the other hand, upon stimulation with Ag plus huCD40/mB7-1-c-TEC both a significant proliferative response and IFN-gamma production were induced in DB14. However, the level of these responses did not reach that induced in the presence of I-Ab L cell. A similar pattern of APC functions was demonstrated with the other B7-independent T cell clone, PAB3, or T cell hybridomas (DBhy22 and BD7-5) which are basically independent of costimulation for the activation. The present finding along with our previous report that several structural differences of I-Ab molecules are present between c-TEC and I-Ab L cell suggests that the distinct APC activity of c-TEC is attributable not only to a lack of B7-1 and CD40 but also to inefficient presentation of MHC-peptide complex on the c-TEC.

[Selective induction of effector functions in a T cell clone following antigen presentation in the presence of thymic epithelial cells]

Selective induction of effector functions in a T cell clone, DB14, specific for pigeon cytochrome c 43-58 (p43-58) and restricted to I Ab was analyzed using professional antigen presenting cells (APC), B hybridoma (Th2.58), and various non professional APC, L cells transfected with I Ab (I-Ab L cells), a medullary thymic epithelial cell line (m-TEC) and a cortical thymic epithelial cell line (c-TEC). The m-TEC and c-TEC (m, c-TEC) expressed I-Ab after culturing with interferon-gamma (IFN-gamma). When stimulated with p43-58 in the presence of I-Ab L cells as well as Th2.58 cells, the DB14 cells showed marked proliferation and exhibited significant cytotoxicity against these APC after 18 hr of culture. By contrast, in the presence of m, c-TEC the DB14 cells showed neither proliferation nor cytotoxicity against these TEC but exhibited considerable detachment activity against them. Furthermore DB14 cells became expressed activation markers (CD69 and CD44) after antigen (p43-58) stimulation with m-TEC or c-TEC. Addition of rIL-2 to the culture of DB14 cells, p43-58 and m, c-TEC restored the proliferative responses. However, it was shown that anergy was not involved in the lack of proliferative response of DB14 cells after antigen stimulation with m, c-TEC. The present findings indicate that differences in APC function are present among non-professional APC and suggest that the selective induction of T cell functions can be achieved using appropriate non-professional APC. The characteristic activation of T cells by TEC may be related to their functional roles in situ.

Detachment activity but not cytotoxicity induced in a T-cell clone following antigen presentation in the presence of thymic epithelial cells

The selective induction of effector functions of a T-cell clone (DB14), specific to pigeon cytochrome c 43-58 (p 43-58) and restricted to I-Ab, was analyzed using a professional antigen-presenting cell, B hybridoma (Th 2.58), and various non-professional antigen-presenting cells (APC), L cells transfected with I-Ab (I-Ab L cells), a medullary thymic epithelial cell line (m-TEC) and a cortical thymic epithelial cell line (c-TEC). The m-TEC, and c-TEC expressed I-Ab upon induction with interferon gamma (IFN-gamma). When stimulated with p 43-58 in the presence of I-Ab L cells as well as Th 2.58 cells, the DB14 cells showed marked proliferation and, after 18 hr of culturing, exhibited significant cytotoxicity against the APC. By contrast, in the presence of m, c-TEC, the DB14 cells showed neither proliferation nor cytotoxicity against these TEC but exhibited considerable detachment activity towards them. Furthermore, DB14 cells became expressed activation markers CD69 or CD44) following stimulation with p 43-58 plus m-TEC or c-TEC. The addition of rIL-2 to the culture of DC14 cells, p 43-58 and m-TEC or c-TEC, restored the proliferative responses. However, it was shown that anergy was not involved in the negligible proliferative responses of DB14 cells after stimulation with p 43-58 plus m, c-TEC. The present findings indicate that differences in APC functions are present among the non-professional APC and suggest that the selective induction of T-cell functions can be achieved using the appropriate non-professional APC. The characteristic activation of T cells by TEC may be related to their functional roles in situ.

Dissociation of Fas-mediated cytotoxicity and FasL expression in a cytotoxic CD4+ T-cell clone. Comparative analysis of Fas-mediated cytotoxicity between a T-hybridoma and a T-cell clone

Fas-mediated cytotoxicity or activation-induced cell death (AICD) were analyzed and compared between a CD4+ cytotoxic T-cell clone (DB14) and a T-hybridoma (DBhy22) both of which bear the same T-cell antigen receptor (TCR) specific for p43-58 and restricted to I-Ab/d. DBhy22 expressed detectable FasL mRNA 4 h after activation through TCR and the expression of FasL mRNA reached a peak after 8 h of activation. The expression level of FasL mRNA was clearly associated with the level of Fas-mediated cytotoxicity and AICD seen after activation. On the other hand, FasL mRNA and FasL molecules were constitutively expressed in DB14 irrespective of the activation state. However, DB14 exhibited the Fas-mediated cytotoxicity only after activation. The present study suggests that Fas-mediated cytotoxicity requires not only FasL expression but also other activation signals.

A potential peptide vaccine against two different strains of influenza virus isolated at intervals of about 10 years

We have developed a strategy for making synthetic peptide vaccines, in which a peptide, HA127-133, derived from the hemagglutinin (HA) of A/Aichi/2/68(H3N2) influenza virus (Aichi/68) is introduced into the Ab binding component consisting of 43-46 and 54-58 residues of a pigeon cytochrome c analogue peptide, 46F50V54A. Indeed, this hybrid peptide, 46F/HA127-133/54A, induced impressive T-cell responses and antibody production neutralizing infectivity of Aichi/68 in vitro. In a subsequent study we found that 46F/HA127-133/54A(18mer) peptide antigen, which had been prepared by substitution at the central five residues of 46F50V54A with HA127-133, generated T-cell responses and neutralizing antibody responses as well. On the basis of these prior findings, in the present study we analyzed immunopotency of 46F/HA127-133/54A(18mer) in vivo administered in several ways to I-Ab mice. We show herein that this peptide vaccine loaded in multilamellar liposomes without adjuvant protects the mice against infection with Aichi/68 within 2 weeks after final immunization. Further, this peptide vaccine was shown to be effective in preventing infection with a naturally occurring antigenic variant, A/Texas/1/77(H3N2), carrying the same sequence at 127-133 of the HA as Aichi/68 virus. Since this part of the HA is relatively conserved among H3 subtype influenza viruses, our peptide vaccine may become the basis for a new strategy to prepare effective vaccines that will overcome the ineffectiveness of classical vaccines attributable to antigenic drift of influenza viruses.