Modified hemoglobin solution as possible perfusate relevant to organ transplantation

A modified hemoglobin solution (<pyridoxylated hemoglobin>-<polyoxyethylene> conjugate solution, PHP solution) has very interesting characteristics such as oxygen-carrying property without corpuscular components. Experimental use of the PHP solution has shown promising possibilities as a perfusate relevant to organ transplantations. 1) Elongation of warm ischemic time in canine kidneys: Dogs survived even with the unilateral kidneys which had been exposed up to 4.5 hour warm ischemia and, thereafter, perfused with the PHP solution. 2) Elongation of perfusion preservation period of canine livers: Dogs survived with the transplanted livers which had been perfused for 48 hours with the PHP solution. 3) Successful perfusion of rat small intestine: Lewis rat intestines perfused and preserved for 12 hours with the PHP solution showed a higher survival rate compared with those with Collins or UW solution. 4) Removal of antibodies: By exchange transfusion with a total of 30-60 ml of the PHP solution, a Lewis rat hematocrit lowered to 5% while IgG went down to nil from 8970 mg/dl, IgA to 28 mg/dl from 118 mg/dl and IgM to 190 mg/dl from 897 mg/dl. This technique is expected to be applicable for removal of the naturally existing antibodies in xenotransplantation.

Clonal unresponsiveness results from an interaction between staphylococcal enterotoxin B and T cells expressing unexpected Vβ elements

The ability of staphylococcal toxins to stimulate large numbers of T cells has led to their designation as a superantigen. Previous studies have indicated that activation of T cells bearing particular V beta elements may be responsible for the toxic effects of these bacterial products. However, the widespread expression of functionally similar proteins by unrelated bacterial species suggests the possibility that these products may represent a successful microbial strategy for subversion of the host antibacterial response. We have examined the effects of the staphylococcal enterotoxin B (SEB) on T cell clones that express different V beta elements. We note that SEB stimulates clones bearing previously defined V beta elements to proliferate and to produce cytokines. In addition, we demonstrate that an interaction between SEB and the TCR of clones that express additional V beta elements, including V beta 2 and V beta 6, results in a sterile form of immunological activation. This activation phenotype is characterized by proliferation without detectable cytokine production and is followed by profound immunological unresponsiveness in vitro and in vivo. We propose that reduced levels of antibacterial responses resulting from this form of T cell unresponsiveness may account for the highly conserved expression of superantigens by diverse bacterial species.

Evaluation of a pyridoxylated hemoglobin polyoxyethylene conjugate solution as a perfusate for small intestine preservation

A new type of artificial blood, pyridoxylated hemoglobin-polyoxyethylene conjugate (PHP) solution, (developed by PHP research group of the department of health and welfare of Japan, and produced by Ajinomoto Co., Inc. Tokyo) as an oxygen-carrying component, has been recently devised using hemoglobin obtained from hemolyzed human erythrocytes. Recently, the studies using this solution as a preservation solution were performed in some instances. To examine the mechanism of improved viability using this solution as a preservation solution, we developed a model of orthotopic small intestine transplantation (OIT) in the rat. As a baseline study, we compared parameters of viability of the grafts preserved in Collins and UW solution to those preserved in PHP solution including a survival rate, a serum level total protein and albumin, and a change in body weight after transplantation. In our study, the simple hypothermia storage together with intestinal perfusion preservation with PHP solution was performed. Animals were divided into 6, 12, and 24 hr preservation groups. All of the rats survived after 6 hr preservation following transplantation. However, in 12 hr storage, five of six rats in PHP solution preservation survived and recovery in body weight after grafting was better than those with Collins and UW solution. We conclude that the PHP solution is, therefore, considered to possibly be a more suitable perfusate for small intestine preservation than Collins and UW solution.

Conventional antigen and superantigen may be coupled to distinct and cooperative T-cell activation pathways

CD4+ T cells are equipped to detect two major classes of ligands. Infectious microbial agents, including bacteria and retroviruses, carry a class of proteins termed superantigens that are recognized by the T-cell receptor in association with class II products of the major histocompatibility complex. Proteins expressed by other cells and organisms are processed by macrophages into peptides that are presented to CD4+ T cells by class II molecules. We have examined CD4+ T-cell clones that proliferate vigorously in response both to conventional peptide antigens and to bacterial or retroviral superantigens. The response to peptide antigen is characterized by a rapid and sustained increase in the levels of intracellular free Ca2+ and a vigorous cytokine response. In contrast, the proliferative response of these clones to bacterial or retroviral superantigen is not accompanied by detectable increases in intracellular Ca2+ or by significant cytokine production. Further analysis of T-cell activation indicates that interaction of a single T-cell receptor with the two types of ligand may be coupled to functionally distinct signaling pathways that interact in a synergistic fashion to achieve T-cell activation.

Displacement of apolipophorin III from the surface of low density lipophorin by human apolipoprotein A-I

A hybrid low density lipophorin particle (LDLp) was prepared by incubation with human apolipoprotein (apo) A-I in vitro. ApoA-I associated with LDLp in a concentration dependent, saturable manner which was accompanied by dissociation of apolipophorin III (apoLp-III). The apoA-I hybrid LDLp had the same lipid composition, density and morphology as native LDLp indicating that displacement of apoLp-III by apoA-I did not affect its structural properties. The molar ratio of apoLp-I:apoLp-II:apoLp-III was maximally reduced from 1:1:16 to 1:1:2 in native versus hybrid LDLp with the latter particle binding 7 molecules of apoA-I. The inability of apoA-I to displace the remaining 2 apoLp-III supports the concept that these apoLp-III molecules are not equivalent to the other fourteen. Native and hybrid LDLp particles were both metabolized to high density lipophorin in vivo. The displacement reaction represents a novel method for the production of apolipoprotein hybrids of LDLp and the results indicate that apoA-I has an inherently higher affinity for lipid surfaces than apoLp-III.

Treatment of small cell lung cancer

During a 28-year period, 110 patients with small cell lung cancer were treated at our hospital. Fifty-nine patients received surgery, and 58 patients (including 7 cases after exploratory thoracotomy) received chemotherapy and/or radiotherapy. The 5-year survival rate of the surgically treated group was 17%, while none in the non-surgical group survived for more than 5 years.

Role of lipid transfer particle in transformation of lipophorin in insect oocytes

Oocyte development in Manduca sexta involves the deposition of large amounts of lipoprotein-derived lipid. One source of this lipid is hemolymph high-density lipophorin-adult (HDLp-A) which, upon entry into the oocyte, is transformed into a lipid and apolipophorin III deficient product particle, egg very-high- density lipophorin (VHDLp-E; density = 1.24 g/ml; Kawooya et al. (1988) J. Biol. Chem. 263, 8740-8747). An in vitro model of this transformation has been established using human low-density lipoprotein (LDL) as acceptor of HDLp-A associated lipid in a reaction catalyzed by isolated M. sexta hemolymph lipid transfer particle (LTP). Facilitated vectorial net transfer of lipid from HDLp-A to LDL resulted in formation of a very-high-density lipophorin (VHDLp) product with a density and apolipoprotein content similar to that of VHDLp-E. Lipid was found to comprise 25% of the VHDLp particle mass, whereas over 50% of HDLp-A mass is lipid. Based on these observations it was hypothesized that a lipid transfer factor may be present in M. sexta oocytes and function in the transformation of HDLp-A to VHDLp-E in vivo. Transfer activity was present in the buffer soluble fraction of oocyte homogenates and purification of the active material revealed a catalyst with electrophoretic and immunological properties identical to hemolymph LTP. Incubation of 125I-HDLp-A with an M. sexta oocyte homogenate resulted in transformation of the radiolabeled lipoprotein to a density corresponding to that of VHDLp-E. When the incubation media was preincubated with anti-LTP IgG this conversion was inhibited to a large extent. Inhibition was relieved, however, by addition of exogenous LTP. The results provide the first demonstration of M. sexta LTP in a tissue other than hemolymph and support the concept that LTP-catalyzed lipid transfer plays an integral role in the conversion of HDLp-A to VHDLp-E in vivo.

Increased nasal resistance induced by the pressure-flow technique and its effect on pressure and airflow during speech

Although the validity of the pressure-flow technique has been verified in a number of laboratories, some questions still remain. The purpose of this study was to determine whether the procedures involved in estimating orifice size affect the pressure and airflow variables being measured. Twenty subjects with demonstrated velopharyngeal inadequacy on pressure-flow testing (VPO greater than or equal to 0.10 cm2) were assessed under two contrasting conditions. Subjects were asked to produce (p) in the word "hamper" with a) one nostril occluded by a cork as in pressure-flow testing and b) both nostrils patent. The results indicate that the increased nasal resistance resulting from occlusion of one nostril does not appreciably affect pressure and airflow associated with plosive consonant production in patients with velopharyngeal inadequacy.

[Comparison of Spatholobus suberectus Dum, Euonymus alatus (Thunb.) Sieb. and Eupolyphaga sinensis Walker on regulation of plasma lipid]

The Spatholobus suberectus (SS) of hexue type, the Euonymus alatus (EA) of huoxue type and the Eupolyphaga sinensis (ES) of poxue type were selected and their influence on plasma lipid in the experimental hyperlipidemia quails was observed. The ES could raise plasma HDL-C/TC ratio and increase LCAT activity. The SS could raise plasma HDL2-C/HDL3-C ratio. The effect of EA on plasma HDL-C/TC, HDL2-C/HDL3-C and LCAT levels was between SS and ES. All the three huoxue huayu Chinese drugs could lower plasma HDL3-C level and slow down the progress of atherosclerosis to a certain degree. The above-mentioned results show that certain orders exist between the action range of huoxue huayu drugs and their effect on regulating plasma lipid.

Impact of Phase I Pew National Dental education Program on U.S. schools of dental medicine

This paper presents the results of four telephone surveys conducted by the Leonard Davis Institute of Health Economics (LDI), University of Pennsylvania, as part of its evaluation of the Pew National Dental Education Program (PNDEP), a five year, +4F8.7 million program established by The Pew Charitable Trusts to help dental schools respond to the changing health care environment. The four annual surveys were conducted between 1985 and 1988. The interviews were conducted with the deans from nearly all dental schools operating in the United States at the time of study or the principal investigators of the schools funded under Phase I and Phase II PNDEP grants. Their purpose was to determine the level of each school's involvement in PNDEP and in specific strategic planning activities, as well as to evaluate the impact of the Pew Program on both the individual schools and dental education nationwide. All systematic differences between schools funded (FD) PNDEP and those not funded (NFD) were examined. Overall, schools gained a better understanding of their environment. Schools also reported increased participation in and commitment to planning among their different constituencies (e.g., faculty, administration, students, alumni). By the end of Phase I, more PNDEP Phase I funded schools reported being involved in implementing strategic plans. Funded schools also were more likely to report PNDEP increased their understanding of strategic planning, improved communication, and helped encourage the emergence of new leaders.

Microsurgical fertilization and teratozoospermia

Semen parameters were correlated with the outcome of partial zona dissection (PZD) in 42 couples with male factor infertility. Although fertilization rates were reduced, 12% of the embryos implanted following replacement. Spermatozoa from teratozoospermic sperm populations were able to fuse with oocytes following zona penetration through the artificial gaps. PZD followed by insemination with less than 5% normal spermatozoa led to 20 embryos which, upon replacement, did not implant. Motility and sperm count were not clearly correlated with the outcome of PZD and are therefore less useful indicators for patient selection. Teratozoospermic patients who previously failed to fertilize were compared to a group of similar patients who had not attempted IVF before. Although fertilization was significantly improved in first-time patients, 41% of the patients whose spermatozoa were initially unable to fertilize had at least one embryo when PZD was performed. Several pregnancies were established in this group. Subzonal sperm insertion (SZI) and PZD were compared in 19 patients using sibling oocytes. A significant fraction of spermatozoa from infertile men were able to fuse with the oolemma when directly inserted into the perivitelline area. Using a sucrose solution to shrink the ooplasm, only 1% of the oocytes were damaged during SZI. Monospermic fertilization rates following PZD and SZI were 15 and 16%, respectively. Both micromanipulation methods were successful in most patients. However, in two small groups of patients, only one technique resulted in fertilization.

[Amino acid analysis of the main organs during different growing periods of panax ginseng C.A. Mey]

Studies on different growing periods of Panax ginseng, its ages and the variation regularities of amino acids in its main organs are reported. The test has shown that it contains seventeen amino acids. The total amount of amino acids reaches its peak point during the sprouting period (in April), next to it is the withering period (in September), flowering and fruiting periods being the lowest (in June). The amount of these acids in the main root is higher than that in the fibrous root, the lowest being in the lateral root. Five-year-old Panax ginseng features the highest amount.

Detection of borderline oxacillin-resistant Staphylococcus aureus and differentiation from methicillin-resistant strains

Eighty-eight Staphylococcus aureus clinical isolates meeting criteria for borderline oxacillin resistance (intermediate susceptibility or resistance to oxacillin but susceptibility to amoxicillin/clavulanic acid upon disk diffusion testing) were studied to determine optimal test techniques and conditions for differentiating borderline oxacillin-resistant Staphylococcus aureus (BORSA) from methicillin-resistant Staphylococcus aureus (MRSA). Further testing revealed three distinct resistance patterns: 61 strains (69%) consistently met BORSA criteria and had average beta-lactamase levels five- to six-fold higher than oxacillin-susceptible controls; 11 strains (13%) were markedly heteroresistant MRSA with delayed appearance of resistant colonies leading to spurious susceptibility to amoxicillin/clavulanic acid; 16 strains (18%) appeared to be oxacillin-susceptible on repetitive testing. Under conditions used to elicit intrinsic methicillin resistance in Staphylococcus aureus, a large percentage of BORSA appeared resistant to amoxicillin/clavulanic acid. This clearly shows that BORSA may be misidentified as MRSA while heteroresistant MRSA may appear to be BORSA. It is concluded that amoxicillin/clavulanic acid zone sizes should be measured after a full 24 hours of incubation, that susceptibility testing of Staphylococcus aureus under certain environmental conditions should be interpreted with caution, and that MIC testing is the most reliable technique for differentiating these two resistance patterns in Staphylococcus aureus.

Regulation of platelet-activating factor receptor and PAF receptor-mediated arachidonic acid release by protein kinase C activation in rat Kupffer cells

Phorbol 12-myristate 13-acetate (PMA), a potent protein kinase C activator, caused down-regulation of receptors for platelet-activating factor (AGEPC) on the plasma membrane of rat Kupffer cells (40-50% reduction) but had a relatively minor effect on the binding affinity of the receptors for AGEPC (Kd = 0.30 nM vs 0.56 nM) when incubated with the cells for a short period of time (30-60 min). As a consequence, the AGEPC receptor-mediated arachidonic acid release was attenuated. The PMA-induced down-regulation of AGEPC receptors was concentration-dependent, specific, and transient (the maximal effect was observed at about 1 h and the level of specific [3H]AGEPC binding gradually returned to the control level within 8.5 h and even higher than the control level at 24 h after addition of PMA). Upon removing PMA from the culture medium, more than half of the lost receptors were replaced within 1 h at 37 degrees C and the recovery process appeared to be independent of protein synthesis. The ability of PMA to down-regulate the AGEPC receptors was lost in cells "down-regulated" for protein kinase C, suggesting that the receptor-regulatory effect of PMA is protein kinase C-dependent. Protein kinase C appeared to be involved in the AGEPC-induced arachidonic acid release since 1-(5-isoquinolinesulfonyl)-2-methyl-piperazine dihydrochloride, a protein kinase C inhibitor, attenuated the stimulatory effect of AGEPC in this system. In addition, AGEPC-induced [3H]arachidonic acid release was inhibited significantly in cells down-regulated for protein kinase C. The present study thus demonstrates that protein kinase C has dual actions in the regulation of AGEPC-mediated events, i.e., a positive forward action, regulating AGEPC-stimulated arachidonic acid release, and a negative action, which inactivates or down-regulates AGEPC receptors.

Immune T cells sorted by flow cytometry confer protection against infection with Treponema pallidum subsp. pertenue in hamsters

The role of cell-mediated immunity against infection with Treponema pallidum subsp. pertenue in humans or experimental animals is unclear. Hamsters injected subcutaneously in the hind paws with 4 x 10(6) unfractionated lymph node cells or enriched lymph node T cells (immunoglobulin negative, Ia negative) from T. pallidum subsp. pertenue-immune hamsters were resistant to challenge with T. pallidum subsp. pertenue. The popliteal lymph nodes of hamsters that received immune cells weighed less and had significantly fewer treponemes than did lymph nodes from hamsters infused with cells from nonimmune donors. Furthermore, recipients of immune T cells failed to develop antitreponemal antibodies 21 days after challenge. Enriched T cells were obtained by flow cytometric separation by using monoclonal anti-Ia antibody 14-4-4s, which identified hamster B cells. Flow cytometric analysis by two-color immunofluorescent staining with anti-hamster-immunoglobulin and monoclonal anti-Ia antibody 14-4-4s confirmed that monoclonal anti-Ia antibody 14-4-4s recognized B cells. In addition, lymph node cells obtained after treatment with anti-Ia monoclonal antibody 14-4-4s and complement were 97% T cells, as determined by monoclonal antibody 20, a hamster T-cell marker. These results demonstrated that highly enriched T cells (immunoglobulin negative, Ia negative) from T. pallidum subsp. pertenue-immune hamsters conferred partial protection on hamsters against infection with T. pallidum subsp. pertenue.

Preventive effect of aluminium citrate on silicosis

Aluminium citrate (Al-cit) was shown to be biologically effective in preventing silicosis. A total of 917 cases selected from both engineering corps of railway and coalmines with stage 0 or 0+ by radiographs were studied. Cases were randomly divided into Al-cit treatment group and control group with continuing dust exposures. Workers in the treatment group were injected with Al-cit at a dose of 120 mg Al/year and these in the control group received a consolatant or nothing during the period of five years. The radiographic changes demonstrated that Al-cit showed clear-cut effects in both retardation of the dust-induced fibrosis and decrease of the morbidity of silicosis.

Regulation of platelet-activating factor receptors in rat Kupffer cells

Ligand binding studies indicate that 1-O-alkyl-2-acetyl-sn-glycero-3-phosphocholine (AGEPC) down-regulates its own receptors on the plasma membrane of isolated rat Kupffer cells but has no significant effect on the binding affinity of the receptor for AGEPC. Exposure of isolated rat Kupffer cells to 10(-8) and 10(-6) M AGEPC resulted in a rapid, time-dependent reduction in the number of cell surface AGEPC receptors to a new steady state concentration (54.1 +/- 5.0% and 38.6 +/- 5.4% of control, respectively). During the observation period (6 h), the half-time of surface AGEPC receptors was about 60 and 45 min in the presence of 10(-8) and 10(-6) M AGEPC, respectively. Both the rate of loss and the maximal loss of the receptors were dependent upon the AGEPC concentration. With receptor synthesis inhibited by cycloheximide in the absence of AGEPC, the half-time of the surface AGEPC receptor was about 4 h, suggesting that AGEPC receptors are not recycled and that the loss of AGEPC receptors from the plasma membrane is accelerated by AGEPC binding. When incubated with Kupffer cells at 37 degrees C for 3 h, 1-O-alkyl-2-lyso-sn-glycero-3-phosphocholine (1.0 microM), an inactive metabolite of AGEPC, did not cause the loss of AGEPC receptors. Under the same conditions, AGEPC antagonists such as BN52021 (2 x 10(-5) M) or U66985 (2 x 10(-5) M) alone had no effect (97.0 +/- 3.9% of control for BN52021) or only a relatively slight effect (78.4 +/- 1.8% for U66985) on the number of surface AGEPC receptors. However, AGEPC antagonists inhibited the AGEPC-induced down-regulation of AGEPC receptors in a concentration-dependent manner, suggesting that the AGEPC-induced down-regulation of AGEPC receptors is a receptor-mediated process. The AGEPC-mediated decrease in receptor number on rat Kupffer cells is reversible. Upon removing AGEPC from the culture medium, about 67% of the lost receptors were replaced within 2 h. Cycloheximide, an inhibitor of protein synthesis, prevented the restoration of the AGEPC receptors. Similar results were obtained when Kupffer cells were incubated with Pronase followed by removing Pronase and reincubating the cells with or without cycloheximide. These observations suggest that the restored AGEPC receptor is newly synthesized rather than recycled. The present study demonstrates that under non-stimulatory (i.e. in the absence of AGEPC) conditions AGEPC receptors are lost from the plasma membrane and are reformed in the cells continuously.(ABSTRACT TRUNCATED AT 400 WORDS)

[An analysis of criminal liability in a criminal case involving an epileptic]

This paper presents the case of an epileptic patient who killed his wife during the intermittent period of epilepsy: three different units were asked to give the forensic psychiatric appraisement which came to three different conclusions, namely, the patient should be entitled to no criminal responsibility, partial criminal responsibility, and full criminal responsibility with respect to these three conclusions, the authors make a detailed discussion and give their own opinions.

Identification of receptors for platelet-activating factor in rat Kupffer cells

Ligand binding studies demonstrated that isolated rat Kupffer cells possess high affinity binding sites for platelet-activating factor (1-O-alkyl-2-acetyl-sn-glycero-3-phosphocholine, AGEPC). AGEPC binding reached saturation within 10 min at 25 degrees C and was reversible. A Scatchard analysis revealed a single class of AGEPC receptors numbering about 10,600 sites/cell and possessing a dissociation constant of 0.45 nM. Similar values for the dissociation constant for AGEPC (0.12 and 0.34 nM) were obtained independently by kinetic analysis of specific AGEPC binding. AGEPC binding was stereospecific and was inhibited by Zn2+ and AGEPC receptor antagonists including BN52021 and U66985. The AGEPC receptor was functionally active since it was shown to mediate arachidonic acid release and eicosanoid production in Kupffer cells, and these events were inhibited by AGEPC receptor antagonist BN52021. The receptor-mediated arachidonic acid release was extracellular calcium-dependent and was abolished by calcium channel blocker prenylamine and by [ethylenebis(oxyethylenenitrilo)]tetraacetic acid, indicating that calcium influx through a receptor-regulated calcium channel in the plasma membrane is involved in the AGEPC-induced arachidonic acid release. It is suggested that rat Kupffer cells have specific and functionally active AGEPC receptors which are involved in signaling mechanisms which govern the production of several other autacoid-type mediators in the liver.

Phagocytosis of Treponema pallidum pertenue by hamster macrophages on membrane filters

The role of the macrophage in destruction of virulent treponemes is disputed. A major obstacle has been the inability to demonstrate quantitative phagocytosis of treponemes by macrophages. Treponema pallidum pertenue was attached to polycarbonate filters for assessment of treponemal phagocytosis by macrophages. The disappearance of treponemes due to phagocytosis was measured by enumeration with immunofluorescence. Resident and lipopolysaccharide-activated macrophages were found to phagocytize treponemes equally well. The phagocytosis of killed treponemes by macrophages was enhanced by opsonization with immune serum. Macrophages successfully phagocytized Staphylococcus aureus organisms when they were incubated on filters under identical conditions. Treatment of macrophages with cytochalasin B, a known inhibitor of phagocytosis, prevented the disappearance of treponemes and phagocytosis of S. aureus. In addition, fluorescent treponemal debris was observed only inside macrophages cultured with treponemes. These results demonstrate that macrophages can phagocytize pathogenic treponemes on polycarbonate filters.

[Clonal propagation of Gynostemma pentaphyllum (Thumb.) Makino in test tubes]

The explants taken from adventitious shoots or nodes of adventitious bud of Gynostemma pentaphyllum produced numerous shoots on MS medium supplemented with BA 1mg/L and IAA 0.05 mg/L. When the segments of shoots were grown on the 1/2MS medium supplemented with IBA 1 mg/L, roots were initiated differentiating to plantlets. Substitution of polyurethane sponge for agar can accelerate the growth of platlets.

Potentially lethal ventricular arrhythmias: from mundane to esoteric

Patients with potentially lethal ventricular arrhythmias (VAs) represent a heterogenous group with frequent and high grade ventricular arrhythmias (including couplets and runs of nonsustained ventricular tachycardia), structural heart disease and decreased left ventricular function. This is a group at intermediate risk of sudden death, with risks varying from 10% to 38%. The electrical and mechanical risks of patients with potentially lethal VA is discussed in relation to their ability of promoting sudden death. The studies reviewing the impact of antiarrhythmic treatment on survival of patients with potentially lethal VA is discussed.

[Fiberscopic study of velopharyngeal function in 170 normal subjects]

This paper established a quantitative methodology for evaluating the velopharyngeal function (VPF) using NPF. The reliability of this method was testified. On the basis of this result, the observation of normal velopharyngeal function was carried out in 170 normal individuals. The authors presented the percentage of VPI during phonating five Chinese vowels, the highest one was "a" (52.3%), the lowest ones were "i" and "u" (7.1% and 5.3%). The extent of VPI was measured, the mean of "a"'s RVPI was 13.9%, and the means of "i"'s and "u"'s RVPI were 9.3% and 9.7% respectively. The authors suggested the RVPI "i" and RVPI "u" as two parameters for assessing VPF.

Effects of tensile stress on the R lines of Cr(3+) in a sapphire fiber

We have investigated the spectroscopic properties of a crystalline sapphire fiber unintentionally doped with Cr(3+). We find that tensile stress produces blue shifts of the R lines and changes in their radiative lifetimes and integrated intensities that can be correlated to stress-induced changes of the crystal-field parameters.