Role of Sodium Bicarbonate in Resuscitation of out-of-Hospital Cardiac Arrest

Objective

To report the use of sodium bicarbonate (SB) in out-of-hospital cardiac arrest (OHCA) and to explore the role of sodium bicarbonate in resuscitation of OHCA in terms of restoration of spontaneous circulation (ROSC) and survival, and existence of dose-dependent relationship, especially in those with prolonged arrest.

Design

Retrospective cohort study.

Setting

Emergency department of two regional hospitals in a cluster of Hong Kong.

Methods

Adult patients aged at least 18 years old who presented to the study centres with non-traumatic OHCA in the period between March 2013 and December 2013 were included. Cases in which resuscitations were considered medically futile or not actually performed were excluded. Those with do-not-resuscitate (DNR) order or advance directives, those who were death before arrival with postmortem changes, and those who developed ROSC before or within 15 minutes of arrival were excluded from the study. Patients with known poisoning from tricyclic antidepressant or other sodium channel blockers were excluded from analysis if any. The primary outcome of this study was ROSC. Other outcome variables included survival to hospital admission (STA) and survival to hospital discharge (STD).

Results

A total of 489 patients were included during the study period for analysis. We found that patients who received sodium bicarbonate injection (SB group) during CPR had a higher percentage of ROSC than those who did not (no-SB group) (60.8% vs 22.5%; p<0.001). The survival-to-admission rate was higher in the SB group (56.8%) compared with the contrary (21.4%). The difference of survival-to-discharge between the two groups did not reach statistical significance (4.1% in SB group and 2.9% in the no-SB group; p=0.484). The rate of ROSC was found to be dose dependent, being higher in higher dose of SB administration. The ROSC rate increased from no-SB (22.4%) to 57.1% if given 50 ml SB, and further to 64.1% if given ≥100 ml SB.

Conclusions

Our study shows that the use of sodium bicarbonate in the CPR of OHCA is beneficial in ROSC. The effect is dose dependent, with better results in higher dose (>100 ml) of sodium bicarbonate; however, we fail to demonstrate its benefit for prolonged CPR cases (>30 minutes). (Hong Kong j.emerg. med. 2015;22:281-290)

Abstract P4-16-03: Effect of doxorubicin and paclitaxel on adipose-derived stem cells and breast cancer cells: Can we incorporate chemotherapy into our reconstructive strategies?

Introduction: Breast surgery often results in physical deformities that significantly diminish patient's quality of life. A natural and aesthetically pleasing breast reconstruction can be achieved through autologous fat grafting and the success of this technique has largely been attributed to the regenerative properties of adipose-derived stem cells (ASCs) within fat graft. However, in the setting of resected breast cancer, the growth stimulating and angiogenic effects of ASCs pose a risk of increasing local recurrence rates. Although the safety of autologous fat grafting in the breast cancer population has yet to be determined, potential recurrence risk may be minimized through incorporating tumor-suppressing elements in the graft. This study aimed to determine if doxorubicin and paclitaxel could be used to inhibit breast cancer cells while maintaining the viability and functionality of ASCs in vitro.

Materials and methods: Human ASCs were isolated from non-diabetic female patients between 35 and 60 years of age (n = 3). BT-474 and MDA-MB-231 were obtained from ATCC. ASCs, ASCs undergoing adipogenic differentiation, and breast cancer cells were each exposed to a range of doxorubicin-HCl (0, 10, 30, 100, 300, 1000, 3000, or 10000nM) or paclitaxel (0, 0.1, 0.3, 1, 3, 10, 30, 100, or 300nM) concentrations. Proliferation, viability, and differentiation capacity were assessed with commercially available CyQuant, MTT, and AdipoRed assay kits, respectively.

Results: Dose-dependent inhibition was observed for doxorubicin in ASCs and both breast cancer cell lines. The IC50 of doxorubicin on ASCs, BT-474, and MDA-MB-231 were 901.3, 656.5, and 333 nM, respectively. Dose-dependent inhibition for paclitaxel was only observed in BT-474 and MDA-MB-231 cells, with IC50 values of 1.809 and 3.477 nM, respectively. ASCs maintained greater than 80% viability over the range of paclitaxel concentrations tested and consequently and IC50 value could not be determined. ASCs differentiation into mature adipocytes was not inhibited by doxorubicin exposure.

Discussion: In vitro cytotoxicity studies demonstrated greater doxorubicin and paclitaxel sensitivity in BT-474 and MDA-MB-231 than in ASCs. Furthermore, the presence of doxorubicin did not inhibit ASC differentiation into mature adipocytes. These findings suggest that incorporating chemotherapeutic drugs in fat grafts for breast reconstruction following primary breast cancer surgery may be a viable option for decreasing the risk of cancer recurrence.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P4-16-03.

High-level dosimetry at the demagnetization experiments of permanent magnets

The measurements of high-energy and high dose mixed radiation from high-energy electron accelerator are carried out using a radiation damage monitor. It consists of two Radiation-Sensing Field-Effect Transistors (RADFETs) for total absorbed dose from mainly gamma ray and other charged particles and a Si PIN diode for neutron fluence. This is a part of the demagnetization study of rare earth permanent magnet irradiated by 2.5-GeV electron beam. The sensitivities of damage detectors are measured using 65-MeV quasi-monoenergic neutron, 14-MeV D-T neutron, (252)Cf neutron for Si PIN diode and (60)Co and (137)Cs gamma ray for RADFETs. Measured sensitivities are in acceptable range in the comparison of producer's proposed values. The dose and fluence measurements are carried out for the same target condition, Cu and Ta, as that for the demagnetization study. The 5 x 5 cm(2) cross-sectional and 5.5-cm-thick Pb target is also used for the general comparison with photoneutron yields. All measured dose and fluence are compared with the calculated results using the FLUKA code and agree well each other. The application of this kind of radiation damage monitor to high-level dosimetry at high-energy electron accelerator has been discussed.

Feasibility study of nitrogen removal with the mecellulose wasted liquor as an external carbon source in the two-stage denitrification process

The utilization of mecellulose wasted liquor (MWL) as an external carbon source was investigated to find an alternative for methanol in the two-stage denitrification pilot process. The pilot plant was supplied with the raw water from the J-Municipal Sewage Treatment Plant (J-MSTP) in Korea. The raw water of J-Municipal Sewage Treatment Plant contains low and high concentration of biodegradable organics and nitrogen source, respectively, due to the inflow of industrial wastewater and landfill leachate. Methanol was fed to provide external carbon source for high concentration of nitrogen source removal by denitrification in this J-Municipal Sewage Treatment Plant, and thus this study was performed to test effects to the effluent quality and efficiencies of nitrogen source removal with an alternative carbon source for the cost reduction. The 6.5mg 1(-1) and 5.7mg l(-1) of total nitrogen (TN) concentration in the effluent were achieved with mecellulose and methanol, whereas mecellulose and methanol were fed to give the same ratio of gCODgNO,-N(-1), respectively. The 60% of COD in mecellulose wasted liquor was used as a carbon source for denitrification and the stable denitrification rate was earned when one half of the required total carbon source for denitrification was fed to pre-anoxic tank in the pilot plant. The required gCODgNO,-N(-1) ratio with mecellulose wasted liquor was 1.4 times higher than with methanol. Mecellulose wasted liquor is feasible to be used as external carbon source for organic loading, nitrogen and phosphorus removal. If mecellulose wasted liquor is considered as an alternative external carbon source to substitute methanol 26-28m3 mecellulose wasted liquor per 1 m3 methanol will be required. However, to meet with the effluent standard (10 mg BOD l(-1)) for J-Municipal Sewage Treatment Plant, the feed concentration of mecellulose wasted liquor should be recommended to be lower than 200 mgl(-1).

Use of SoftPerm contact lenses when rigid gas permeable lenses fail

PURPOSE

We evaluated the performance of the SoftPerm contact lens (Wesley Jessen) in patients with irregular astigmatism, usually due to keratoconus or after penetrating keratoplasty (PK), who were unable to befitwith, or intolerant of, rigid gas permeable (RGP) contact lenses.

METHODS

A retrospective study of patients fit with SoftPerm lenses in the Cornea Department at Wills Eye Hospital between March 1985 and March 2000 was performed.

RESULTS

Thirty-five cases were reviewed, with follow-up available in 33 cases. Most of the eyes had irregular astigmatism secondary to keratoconus (22/35,62.9%) or PK (10/35,28.6%) and had failed a trial of RGP lenses. The mean logMAR visual acuity with SoftPerm lenses was 0.13+/-0.18 (range -0.12 to 0.6). In 25 cases in which comparison with glasses or RGP lenses was possible, SoftPerm lenses provided better visual acuity than glasses in 17/25 cases (68%) with a mean difference of -0.24 (P = 0.001, paired t-test); visual acuity with SoftPerm lenses was better than RGP visual acuity in 13/25 cases (52%), with a mean difference of -0.06 (P = 0.07, paired t-test). Complications included broken lenses (16/33,48.5%), giant papillary conjunctivitis (GPC) (9/33, 27.3%), and peripheral corneal neovascularization (9/33, 27.3%). The GPC and peripheral corneal neovascularization were often delayed in presentation. The major subjective complaint was discomfort (13/33, 39.4%). At the last follow-up, the SoftPerm lens was still in use in 22/33 cases (66.7%). Discomfort was the most common reason for discontinuation. The mean duration of lens wear was 52.5+/-31.7 months, range 3 to 110 months.

CONCLUSIONS

The SoftPerm lens can provide satisfactory visual correction in many cases of irregular astigmatism with RGP failure. However, problems such as frequent breakage, GPC, peripheral corneal neovascularization, and discomfort necessitate close follow-up.

Cometabolic biosynthesis of copolyesters consisting of 3-hydroxyvalerate and medium-chain-length 3-hydroxyalkanoates by Pseudomonas sp. DSY-82

A newly isolated strain, designated as Pseudomonas sp. DSY-82, synthesized medium-chain-length polyhydroxyalkanoate (MCL-PHA) copolyesters when grown on alkanoates from hexanoate to undecanoate as the sole carbon source. When used alone, butyrate and valerate supported the growth of the isolate but not PHA production. However, unusual polyesters containing 3-hydroxyvalerate, as well as various MCL 3-hydroxyalkanoate monomeric units, were synthesized when valerate was cofed with either nonanoate or 10-undecenoate, suggesting the formation of monomer units from both substrates. Concentrations of 3-hydroxyvalerate, 3-hydroxyoctanoate, and 3-hydroxydecanoate in the PHAs produced were significantly elevated by the addition of valerate, indicating that the incorporation of these monomer units to PHA occurred primarily through cometabolism. The total amount of these monomer units in the PHAs reached up to 30%. The PHAs produced in this study were most likely random copolyesters as determined by differential scanning calorimetric analysis. This is the first case of microbial synthesis of copolyesters consisting of 3-hydroxyvalerate and MCL 3-hydroxyalkanoate monomer units through cometabolism.

FLASH coordinates NF-kappa B activity via TRAF2

FLASH is a protein recently shown to interact with the death effector domain of caspase-8 and is likely to be a component of the death-inducing signaling complex in receptor-mediated apoptosis. Here we show that antisense oligonucleotide-induced inhibition of FLASH expression abolished TNF-alpha-induced activation of NF-kappaB in HEK293 cells, as determined by luciferase reporter gene expression driven by a NF-kappaB responsive promoter. Conversely, overexpression of FLASH dose-dependently activated NF-kappaB, an effect suppressed by dominant negative mutants of TRAF2, NIK, and IKKalpha, and partially by those of TRAF5 and TRAF6. TRAF2 was co-immunoprecipitated with FLASH from the cell extracts of HEK293 cells or HeLa cells stably expressing exogenous FLASH (HeLa/HA-FLASH). Furthermore, serial deletion mapping demonstrated that a domain spanning the residues 856-1191 of FLASH activated NF-kappaB as efficiently as the full-length and could directly bind to TRAF2 in vitro and in the transfected cells. Taken together, these results suggest that FLASH coordinates downstream NF-kappaB activity via a TRAF2-dependent pathway in the TNF-alpha signaling.

Comparison of balloon dacryocystoplasty to probing as the primary treatment of congenital nasolacrimal duct obstruction

PURPOSE

In children older than 18 months, primary probing procedures for congenital nasolacrimal duct obstruction (CNLDO) are thought to have lower rates of success. This study compares the results of primary probing to balloon dacryocystoplasty (DCP) in children stratified by age category.

METHODS

In a retrospective chart review, 29 eyes with CNLDO that underwent balloon DCP in children older than 18 months were identified and age-matched to 29 eyes that underwent probing. The eyes were divided into 3 age categories: category 1 (18-24 months), category 2 (24-36 months), and category 3 (>36 months).

RESULTS

Of the 29 eyes treated with balloon DCP (mean age, 37.1 months), 26 were successfully treated. Twenty-five of the 29 matched probed eyes (mean age, 31.1 months) were successfully treated, resulting in an overall success rate of 90% for balloon DCP and 86% for primary probing. Within each age category, the success rate varied but did not show an advantage to balloon DCP. The presence of crusting and expressible discharge from the puncta during preoperative evaluation predicted a successful probing (OR, 16; 95% CI, 1.3-192).

CONCLUSION

Overall, balloon DCP did not appear to present an advantage as compared with primary probing as the initial treatment in these children. Primary probing has an impressive overall success rate that did not diminish in the children older than 36 months.

Cleavage of Bax is mediated by caspase-dependent or -independent calpain activation in dopaminergic neuronal cells: protective role of Bcl-2

Two cysteine protease families, caspase and calpain, are known to participate in cell death. We investigated whether a stress-specific protease activation pathway exists, and to what extent Bcl-2 plays a role in preventing drug-induced protease activity and cell death in a dopaminergic neuronal cell line, MN9D. Staurosporine (STS) induced caspase-dependent apoptosis while a dopaminergic neurotoxin, MPP(+) largely induced caspase-independent necrotic cell death as determined by morphological and biochemical criteria including cytochrome c release and fluorogenic caspase cleavage assay. At the late stage of both STS- and MPP(+)-induced cell death, Bax was cleaved into an 18-kDa fragment. This 18-kDa fragment appeared only in the mitochondria-enriched heavy membrane fraction of STS-treated cells, whereas it was detected exclusively in the cytosolic fraction of MPP(+)-treated cells. This proteolytic cleavage of Bax appeared to be mediated by calpain as determined by incubation with [(35)S]methionine-labelled Bax. Thus, cotreatment of cells with calpain inhibitor blocked both MPP(+)- and STS-induced Bax cleavage. Intriguingly, overexpression of baculovirus-derived inhibiting protein of caspase, p35 or cotreatment of cells with caspase inhibitor blocked STS- but not MPP(+)-induced Bax cleavage. This appears to indicate that calpain activation may be either dependent or independent of caspase activation within the same cells. However, cotreatment with calpain inhibitor rescued cells from MPP(+)-induced but not from STS-induced neuronal cell death. In these paradigms of dopaminergic cell death, overexpression of Bcl-2 prevented both STS- and MPP(+)-induced cell death and its associated cleavage of Bax. Thus, our results suggest that Bcl-2 may play a protective role by primarily blocking drug-induced caspase or calpain activity in dopaminergic neuronal cells.

Human immunodeficiency virus p24 antigen testing in cornea donors

PURPOSE

Testing for the p24 antigen of the human immunodeficiency virus (HIV) may detect early HIV infection in the seronegative window; however, falsely reactive results may occur in cadaver specimens. Although neither the Food and Drug Administration (FDA) nor the Eye Bank Association of America requires p24 testing of cornea donors, many tissue banks using other organs from cornea donors do perform this assay, and the FDA requires that eye banks reject corneal tissue if a reactive p24 assay is reported. We investigated the impact of p24 testing on eye banking and corneal transplantation.

METHODS

Two clinical cases and records from the Lions Eye Bank of Delaware Valley (LEBDV) were reviewed retrospectively.

RESULTS

Two corneas from the LEBDV were transplanted before the reporting of p24 reactivity by other tissue banks. In one case, because of the young age of the recipient, the surgeon elected to replace the cornea with new tissue hours after the original transplant, and later polymerase chain reaction (PCR) testing was negative. In the other case, there was not enough specimen to perform Western blot or PCR confirmatory testing. The patient was followed with periodic serologic testing for HIV and has remained seronegative. To avoid such problems in the future, the LEBDV initiated testing of all donors with p24 and other nonrequired screening tests. Over a 2-month period, 22 corneas (from 11 donors) were discarded because of these tests: 4 donors had reactive p24 tests, 6 were reactive for antibody to hepatitis B core antigen, and 1 had a reactive syphilis test.

CONCLUSIONS

Results from p24 assays by other tissue banks may cause difficult clinical situations when the results are received after transplantation of the tissue, but the use of the p24 assay in the screening of cornea donors may result in excessive waste of donor tissue. Further guidance is needed regarding the management of positive results from this and other nonrequired screening tests.

An anti-apoptotic protein human survivin is a direct inhibitor of caspase-3 and -7

Survivin, an apoptosis inhibitor/cell-cycle regulator, is critically required for suppression of apoptosis and ensuring normal cell division in the G2/M phase of the cell cycle. It is highly expressed in a cell cycle-regulated manner and localizes together with caspase-3 on microtubules within centrosomes. Whether survivin is a physiologically relevant caspase inhibitor has been unclear due to the difficulties with obtaining correctly folded survivin and finding the right conditions for inhibition assay. In this study, recombinant, active human survivin was expressed in Escherichia coli and purified to homogeneity. The protein, existing as a homodimer in solution, binds caspase-3 and -7 tightly with dissociation constants of 20.9 and 11.5 nM, respectively, when evaluated by surface plasmon resonance spectroscopy. Consistently, survivin potently inhibits the cleavage of a physiological substrate poly(ADP-ribose) polymerase and an artificial tetrapeptide by caspase-3 and -7 in vitro with apparent inhibition constants of 36.0 and 16.5 nM, respectively. The data suggest that sequestering caspase-3 and -7 in inhibited states on microtubules is at least one mechanism of survivin in the suppression of default apoptosis in the G2/M phase. The localization of survivin on microtubules, which is essential for its function, should increase the protective activity at the action site.

Pro-apoptotic function of calsenilin/DREAM/KChIP3

Apoptotic cell death and increased production of amyloid b peptide (Ab) are pathological features of Alzheimer's disease (AD), although the exact contribution of apoptosis to the pathogenesis of the disease remains unclear. Here we describe a novel pro-apoptotic function of calsenilin/DREAM/KChIP3. By antisense oligonucleotide-induced inhibition of calsenilin/DREAM/KChIP3 synthesis, apoptosis induced by Fas, Ca2+-ionophore, or thapsigargin is attenuated. Conversely, calsenilin/DREAM/KChIP3 expression induced the morphological and biochemical features of apoptosis, including cell shrinkage, DNA laddering, and caspase activation. Calsenilin/DREAM/KChIP3-induced apoptosis was suppressed by caspase inhibitor Z-VAD and by Bcl-XL, and was potentiated by increasing cytosolic Ca2+, expression of Swedish amyloid precursor protein mutant (APPSW) or presenilin 2 (PS2), but not by a PS2 deletion lacking its C-terminus (PS2/411stop). In addition, calsenilin/DREAM/KChIP3 expression increased Ab42 production in cells expressing APPsw, which was potentiated by PS2, but not by PS2/411stop, which suggests a role for apoptosis-associated Ab42 production of calsenilin/DREAM/KChIP3.

Penetrating keratoplasty in iridocorneal endothelial syndrome

PURPOSE

To evaluate the clinical outcome of penetrating keratoplasty (PK) in iridocorneal endothelial (ICE) syndrome.

METHODS

Clinical charts of patients who underwent penetrating keratoplasty for ICE syndrome between 1985 and 1999 were reviewed retrospectively. Glaucoma control, best corrected visual acuity pre- and post-PK, graft clarity, graft rejection episodes, improvement in pain, and additional procedures were analyzed.

RESULTS

Fourteen cases were reviewed with an average follow-up of 58 months after PK. Initial grafts failed in seven patients (50%), in six cases because of rejection, and one owing to endothelial failure without signs of rejection. Repeat PKs were performed in six patients. At final follow-up, 12 grafts were clear. Glaucoma was controlled pre- and post-PK (average intraocular pressure, 16 mmHg for both eyes). Pre-PK, eight patients were using glaucoma medicines and nine had had glaucoma surgery. At the end of the follow-up, seven patients were using glaucoma medicines; six patients required glaucoma surgery after their initial PK. At the final follow-up visit, visual acuity in three patients (21%) was 20/40 or better, it ranged from 20/50 to 20/100 in four patients (29%) and 20/200 to 20/400 in five patients (36%), and in two patients with failed grafts (14%) it was counting fingers or worse.

CONCLUSION

Clear grafts were achieved in 12 cases, although six patients (43%) underwent repeat PKs. All patients had glaucoma, which was controlled before and after PK by medical treatment and surgical procedures. Favorable outcomes can be achieved in patients with ICE syndrome but may require multiple corneal and glaucoma procedures.

Proapoptotic effects of tau cleavage product generated by caspase-3

Using an in vitro translation assay to screen a human brain cDNA library, we isolated the microtubule-associated protein Tau and determined it to be a caspase-3 substrate whose C-terminal cleavage occurred during neuronal apoptosis. DeltaTau, the 50-kDa cleavage product, was detected by Western blot in apoptotic cortical cells probed with anti-PHF-1 and anti-Tau-5 antibodies, but not anti-T-46 antibody which recognizes the C-terminus. Overexpression of DeltaTau in SK-N-BE2(C) cells significantly increased the incidence of cell death. Staurosporine-induced Tau cleavage was blocked by 20 microM z-Asp-Glu-Val-Asp-chloromethylketone, a caspase-3 inhibitor, and in vitro, Tau was selectively cleaved by caspase-3 or calpain, a calcium-activated protease, but not by caspases-1, -8, or -9. (D421E)-Tau, a mutant in which Asp421 was replaced with a Glu, was resistant to cleavage by caspase-3 and tended to suppress staurosporine-induced cell death more efficiently than did wild-type Tau in both transient and stable expression systems. Finally, the incidence of DeltaTau-induced cell death was augmented by expression of Abeta precursor protein (APP) or Swedish APP mutant. Taken together, these results suggest that the caspase-3 cleavage product of Tau may contribute to the progression of neuronal cell death in Alzheimer's disease.

An anti-apoptotic protein human survivin is a direct inhibitor of caspase-3 and -7

Survivin, an apoptosis inhibitor/cell-cycle regulator, is critically required for suppression of apoptosis and ensuring normal cell division in the G2/M phase of the cell cycle. It is highly expressed in a cell cycle-regulated manner and localizes together with caspase-3 on microtubules within centrosomes. Whether survivin is a physiologically relevant caspase inhibitor has been unclear due to the difficulties with obtaining correctly folded survivin and finding the right conditions for inhibition assay. In this study, recombinant, active human survivin was expressed in Escherichia coli and purified to homogeneity. The protein, existing as a homodimer in solution, binds caspase-3 and -7 tightly with dissociation constants of 20.9 and 11.5 nM, respectively, when evaluated by surface plasmon resonance spectroscopy. Consistently, survivin potently inhibits the cleavage of a physiological substrate poly(ADP-ribose) polymerase and an artificial tetrapeptide by caspase-3 and -7 in vitro with apparent inhibition constants of 36.0 and 16.5 nM, respectively. The data suggest that sequestering caspase-3 and -7 in inhibited states on microtubules is at least one mechanism of survivin in the suppression of default apoptosis in the G2/M phase. The localization of survivin on microtubules, which is essential for its function, should increase the protective activity at the action site.

Inactivation of farnesyltransferase and geranylgeranyltransferase I by caspase-3: cleavage of the common alpha subunit during apoptosis

Caspase plays an important role in apoptosis. We report here that farnesyltransferase/geranylgeranyltransferase (FTase/GGTase)-alpha, a common subunit of FTase (alpha/beta(FTase)) and GGTase I (alpha/beta(GGTase)), was cleaved by caspase-3 during apoptosis. FTase/GGTase-alpha (49 kDa) was cleaved to 35 kDa (p35) in the Rat-2/H-ras, W4 and Rat-1 cells treated with FTase inhibitor (LB42708), anti-Fas antibody and etoposide, respectively. This cleavage was inhibited by caspase-inhibitors (YVAD-cmk, DEVD-cho). Serial N-terminal deletions and site-directed mutagenesis showed that Asp59 of FTase/GGTase-alpha was cleaved by caspase-3. The common FTase/GGTase-alpha subunit, but not the beta subunits, of the FTase or GGTase I protein complexes purified from baculovirus-infected SF-9 cells was cleaved to be inactivated by purified caspase-3. In contrast, FTase mutant protein complex [(D(59)A)alpha/beta(FTase)] was resistant to caspase-3. Expression of either the cleavage product (60-379) or anti-sense of FTase/GGTase-alpha induced cell death in Rat-2/H-ras cells. Furthermore, expression of (D(59)A)FTase/GGTase-alpha mutant significantly desensitized cells to etoposide-induced death. Taken together, we suggest that cleavage of prenyltransferase by caspase contributes to the progression of apoptosis.

Effect of dietary linoleate/alpha-linolenate balance on the brain lipid composition, reproductive outcome and behavior of rats during their prenatal and postnatal development

The effect of the dietary linoleate (LA)/alpha-linolenate (LNA) balance during development on the brain lipid composition, reproductive outcome and behavior of rats was studied. Female rats were fed on experimental diets during pregnancy and the resulting pups for 16 weeks. The dietary LA/LNA ratios were 1.07 (LA1), 2.64 (LA2), 4.45 (LA3), 7.68 (LA4) and 10.35 (LA5). The relative content of docosahexaenoate (DHA) in the brain of pups tended to increase with decreasing LA/LNA ratio at 0 and 3 weeks, while the level of DHA was maintained constant at 16 weeks regardless of the dietary LA/LNA ratio. The learning ability was measured at 12 weeks of age, and there was no difference among the groups. In an open field test, the exploratory index was significantly lower in the LA1 group than in the LA2 group. The LA1 group had a smaller litter size and lower survival rate than the other groups. We conclude that if the diet contained appropriate amounts and balance of LA and LNA, it was possible for rats to synthesize an appropriate amount of DHA and have normal behavioral activity without DHA supplementation.

Nonlocal electron kinetics in a planar inductive helium discharge

A measurement of the electron energy distribution function (EEDF) using the ac superposition method is done over a helium pressure range of 10-100 mTorr in a planar inductive plasma, and the electron energy diffusion coefficient which describes the electron heating is calculated based on the same discharge conditions using a two-dimensional simulation. It is found that the measured EEDF shows a bi-Maxwellian distribution with a low-energy electron group at low pressures below 20 mTorr even in the inductive discharge using helium of the non-Ramsauer gas. The major factors which can affect the EEDF formation are investigated. In particular, the concept of the total electron bounce frequency, i.e., the electron residence time, is introduced as an indicator of how the electron-electron collision affects the EEDF shape. As a result, it is shown that the observed bi-Maxwellian distribution at low pressures is attributed to the combined effects of the formation of low-energy electrons through the cooling mechanism of energetic electrons enhanced by the capacitive field, the low heating rate of the low-energy electrons, the confinement of low-energy electrons by the ambipolar space potential, and the low electron-electron collision frequency which can be estimated from the total electron bounce frequency presented in this paper.

Reconstitution of caspase-8 sensitizes JB6 cells to TRAIL

TRAIL induces apoptosis in various tumor cells. We report here that caspase-8 is required in TRAIL-induced cell death. Western blot analyses and enzyme assays showed that exposing Jurkat cells to TRAIL resulted in activation of caspases-8 followed by caspase-3 and -9. Acetyl-IETD-fluoromethylketone, a caspase-8 inhibitor, potently suppressed TRAIL-induced cell death compared to acetyl-DEVD-fluoromethylketone and acetyl-LEHD-fluoromethylketone, inhibitors of caspase-3 and caspase-9, respectively. JB6 cells, a caspase-8-deficient Jurkat variant, were completely resistant to TRAIL. However, reconstitution with a caspase-8, but not with caspase-2 or -3, sensitized JB6 cells to subsequent exposure to TRAIL. These results are indicative of the crucial function of caspase-8 in TRAIL-induced apoptosis in Jurkat cells.

Laparoscopic splenectomy for immune thrombocytopenic purpura--long-term result of 40 laparoscopic splenectomies

Laparoscopic surgery has recently extended its indications and it has also become an acceptable surgical approach for splenectomy. In the last five years, we have performed 40 laparoscopic splenectomies for immune thrombocytopenic purpura. Thirty-five patients were female and 5 patients were male. The mean age was 34, varying from 17 to 56. After learning to perform laparoscopic splenectomy with five ports, we are now usually using three or four ports in a right lateral kidney position. There was no case of conversion to exploratory laparotomy. The mean hospital stay was 7 days. There was no perioperative mortality; but in 2 cases we had postoperative subphrenic abscesses which were successfully managed by catheter drainage. Since undergoing laparoscopic splenectomy, 28 patients (70%) were weaned effectively from their steroid medications. Eight patients (20%) have been on small doses of steroid, and 4 patients (10%) have been on the same doses of steroid with no response. The patient group with rapidly increasing platelet count after splenectomy showed a statistically significant relation with the complete response group (p < 0.001). Laparoscopic splenectomy is a safe and reasonable operative procedure for patients with immune thrombocytopenic purpura.

Magnesium fluoride-dependent binding of small G proteins to their GTPase-activating proteins

GTPase-activating proteins (GAPs) enhance the intrinsic GTPase activity of small G proteins, such as Ras and Rho, by contributing a catalytic arginine to the active site. An intramolecular arginine plays a similar role in heterotrimeric G proteins. Aluminum fluoride activates the GDP form of heterotrimeric G proteins, and enhances binding of the GDP form of small G proteins to their GAPs. The resultant complexes have been interpreted as analogues of the transition state of the hydrolytic reaction. Here, equilibrium binding has been measured using scintillation proximity assays to provide quantitative information on the fluoride-mediated interaction of Ras and Rho proteins with their respective GAPs, neurofibromin (NF1) and RhoGAP. High-affinity fluoride-mediated complex formation between Rho.GDP and RhoGAP occurred in the absence of aluminum; however, under these conditions, magnesium was required. Additionally, the novel observation was made of magnesium-dependent, fluoride-mediated binding of Ras.GDP to NF1 in the absence of aluminum. Aluminum was required for complex formation when the concentration of magnesium was low. Thus, either aluminum fluoride or magnesium fluoride can mediate the high-affinity binding of Rho. GDP or Ras.GDP to GAPs. It has been reported that magnesium fluoride can activate heterotrimeric G proteins. Thus, magnesium-dependent fluoride effects might be a general phenomenon with G proteins. Moreover, these data suggest that some protein.nucleotide complexes previously reported to contain aluminum fluoride may in fact contain magnesium fluoride.

Development of a robotic navigation system for neurosurgery

This paper presents a robotic navigation system for image-guided neurosurgery, which can be applied to the treatment of Parkinson's disease and biopsy of brain tumor. The system integrates a computer for real-time display of brain anatomy, a magnetic tracking device for measuring the positions and orientations of surgical instruments, and a robot manipulator for guiding surgical instruments to the preplanned positions and orientations. The computer display of brain anatomy offers a convenient tool for surgeons to diagnose brain disease and to plan safe surgical paths; while the tracking device assists the robot manipulator to automatically guide surgical instruments to the preplanned direction. The registrations among the tracking device, the image system, and the robot are completed on the base of coordination mappings of external markers. An experiment of using a skull model for simulating a robotic biopsy of brain tumor has been done to verify the performance of the navigation system. The result shows that the system can accomplish a positioning accuracy around 2 mm.

Cisatracurium neuromuscular block at the adductor pollicis and the laryngeal adductor muscles in humans

We have compared the dose-response relationship (n = 30) and time course of neuromuscular block (n = 20) of cisatracurium at the laryngeal adductor and the adductor pollicis muscles. ED95 values for cisatracurium were 66.8 (95% confidence interval 61.3-72.3) micrograms kg-1 at the larynx and 45.2 (42.1-48.3) micrograms kg-1 at the adductor pollicis muscle (P < 0.0001). After administration of cisatracurium 0.1 mg kg-1, onset time was 2.7 (2.2-3.2) min at the larynx and 3.9 (3.0-4.8) min at the adductor pollicis (P < 0.0001). Time to 95% recovery of the first twitch of the TOF was 26.9 (20.1-33.7) min and 45.6 (39.7-51.5) min, respectively (P < 0.0001). We found that the laryngeal adductors were more resistant to the action of cisatracurium than the adductor pollicis muscle, but onset and recovery were faster at the larynx.

Rabbits treated with chronic isepamicin are resistant to mivacurium and rocuronium

We compared the dose-response relationships and the neuromuscular blocking effects of mivacurium and rocuronium after chronic isepamicin therapy for 7 days in 56 anesthetized rabbits. Train-of-four stimuli were applied every 10 s to the common peroneal nerve, and the force of contraction of the tibialis anterior muscle was measured. Chronic isepamicin therapy is associated with a rightward shift of the mivacurium and rocuronium dose-response curves. The effective dose for 50% twitch depression of mivacurium and rocuronium increased significantly, from 16.9 +/- 4.8 and 56.5 +/- 5.3 microg/kg, respectively, with placebo to 30.6 +/- 5.3 and 75.6 +/- 4.7 microg/kg, respectively, during isepamicin therapy. The isepamicin rabbits receiving mivacurium 0.18 mg/kg or rocuronium 0.6 mg/kg had an accelerated recovery from neuromuscular blockade compared with those receiving placebo. The results of this study show that mivacurium and rocuronium have both a decreased effect and a shorter duration of action in rabbits when used during concurrent isepamicin therapy.

IMPLICATIONS

We studied the dose-response relationships and the neuromuscular blocking effects of mivacurium and rocuronium during chronic isepamicin therapy in rabbits. Mivacurium and rocuronium have both a decreased effect and a shorter duration of action during chronic aminoglycoside antibiotic therapy in rabbits.

Identification of a glycosaminoglycan binding surface on human interleukin-8

The activation of leukocytes by chemokines is believed to be mediated via binding of chemokines to glycosaminoglycan chains of the extracellular matrix. The binding site on the chemokine interleukin-8 (IL-8) for the glycosaminoglycan heparin has been characterized using a systematic series of site-directed mutants of IL-8 in which the basic residues of the protein have been replaced by alanine. Mutation of K64 and R68 caused the largest decrease in affinity for a heparin Sepharose matrix, with smaller effects seen with mutations of K20, R60, and K67. Heparin-derived disaccharides that could disrupt the IL-8-heparin Sepharose interaction were identified by a competitive binding assay. Heteronuclear NMR spectroscopic titration of 15N-labeled IL-8 with a trisulfated disaccharide revealed a cluster of residues on IL-8 which were perturbed by disaccharide binding. These data identify a heparin-binding surface on IL-8 that includes the C-terminal alpha-helix and the proximal loop around residues 18-23. The heparin-binding site is spatially distinct from the residues involved in receptor binding.

The effect of the nasopharyngeal air cavity on x-ray interface doses

We investigated the impact of air cavities in head and neck cancer patients treated by photon beams based on clinical set-ups. The phantom for investigation was constructed with a cubic air cavity of 4 x 4 x 4 cm3 located at the centre of a 30 x 30 x 16 cm3 solid water slab. The cavity cube was used to resemble an extreme case for the nasal cavity. Apart from measuring the dose profiles and central axis percentage depth dose distribution, the dose values in 0.25 x 0.25 x 0.25 cm3 voxels at regions around the air cavity were obtained by Monte Carlo simulations. A mean dose value was taken over the voxels of interest at each depth for evaluation. Single-field results were added to study parallel opposed field effects. For 10 x 10 cm2 parallel opposed fields at 4, 6 and 8 MV, the mean dose at regions near the lateral interfaces of the cavity cube were decreased by 1 to 2% due to the lack of lateral scatter, while the mean dose near the proximal and distal interfaces was increased by 2 to 4% due to the greater transmission through air. Secondary build-up effects at points immediately beyond the air cavity cube are negligible using field sizes greater than 4 x 4 cm2. For most head and neck treatment, the field sizes are usually 6 x 6 cm2 or greater, and most cavity volumes are smaller than our chosen dimensions. Therefore, the influence of closed air cavities on photon interface doses is not significant in clinical treatment set-ups.

Conformational analysis of neuropeptide Y segments by CD, NMR spectroscopy and restrained molecular dynamics

Neuropeptide Y (NPY), a peptide amide comprising 36 residue has been shown to act as a potent vasoconstrictor. In order to shed light on the structural requirements for the biological activities with respect to the different prerequisites for affinity to the NPY receptor subtypes Y1 and Y2, in the present study the syntheses and conformational analyses of two C-terminal segments, NPY(18-36) and NPY(13-36), are described. The results obtained by CD measurements, two-dimensional NMR spectroscopy and a conformational refinement of the NMR-derived structure by molecular mechanics stimulations support the findings of previously published structure-activity relationship studies for biologically active and selective compounds. In particular, the alpha-helical conformation as well as an appropriate exposure of the side chains of the critical C-terminal dipeptide within NPY(18-36) are in agreement with the prerequisites proposed for Y2 receptor binding of that segment.

Selectivity and antagonism of chemokine receptors

The chemokine superfamily can be subdivided into two groups based on their amino terminal cysteine spacing. The CXC chemokines are primarily involved in neutrophil-mediated inflammation and, so far, two human receptors have been cloned. The CC chemokines tend to be involved in chronic inflammation, and recently we have cloned a fourth leukocyte receptor for this group of ligands. Understanding what makes one receptor bind its range of agonists is important if we are to develop potent selective antagonist. We have started to investigate the molecular basis of this receptor selectivity by looking at why CC chemokines do not bind to the CXC receptors in several ways. First, we looked at the role of the three-dimensional structure of the ligand, and have solved the three dimensional structure of RANTES using nuclear magnetic resonance spectroscopy. The structure is similar to that already determined for the CC chemokine macrophage inflammatory protein-1 beta, and it has a completely different dimer interface to that of the CXC chemokine interleukin-8 (IL-8). However, the monomer structures of all the chemokines are very similar, and at physiological concentrations the proteins are likely to be monomeric. Second, by examining all the known CC and CXC chemokines, we have found a region that differs between the two subfamilies. Mutations of one of the residues in this region, Leu-25 in IL-8, to tyrosine (which is conserved at this position in CC chemokines) enables the mutant IL-8 to bind CC chemokine receptor-1 (CC-CKR-1) and introduces monocyte chemoattractant activity. Using other mutations in this region, we can show a direct interaction with the N-terminus of CC-CKR-1. Third, we have found that modification of the amino terminus of RANTES by addition of one amino acid makes it into an antagonist with nanomolar potency. Taken together, this data suggests a two-site model for receptor activation and for selectivity between CC and CXC chemokines, with an initial receptor contact provided by the main body of the chemokine, and activation provided by the amino terminal region.

Peptidergic innervation of the primate meibomian gland

PURPOSE

To localize and characterize nerves in primate meibomian glands using immunohistochemical staining for neuropeptides and neuronal enzymes.

METHODS

Upper eyelids were obtained from seven rhesus monkeys (Macaca mulatta) and one cynomolgous monkey (Macaca fascicularis). The tissues were fixed either by immersion in Zamboni's fixative or by transcardiac perfusion with paraformaldehyde and glutaraldehyde and were then postfixed. Cryostat tissue sections of the lids were stained by immunohistochemistry using rabbit antisera to neuron-specific enolase (NSE), tyrosine hydroxylase (TH), neuropeptide Y (NPY), vasoactive intestinal polypeptide (VIP), calcitonin gene-related peptide (CGRP), and substance P (SP), followed by a fluorescence visualization system.

RESULTS

Used as a marker for the overall nerve distribution, NSE antibodies revealed abundant smooth and varicose nerve fibers closely apposed to the basement membranes of acini of the meibomian glands. Numerous nerve fibers near the meibomian gland acini were immunoreactive for NPY and VIP, but nerve fibers containing TH, CGRP, and SP were more sparse in the meibomian glands. Nerve fibers also were visualized in other eyelid structures, including conjunctiva, epidermis, hair follicles, and subconjunctival lymphoid follicles.

CONCLUSIONS

The meibomian glands of rhesus and cynomolgous monkeys are richly innervated by diverse nerve fiber types. The immunohistochemical staining suggests a largely parasympathetic origin for this innervation, with relatively smaller contributions from sympathetic and sensory sources. These findings also suggest that meibomian gland secretion is under the control of diverse neurotransmitter-neuromodulator mechanisms.

Pulmonary artery aneurysm presenting as a lung mass

We describe a case of pulmonary artery aneurysm in which clinical clues and conventional imaging suggested a lung tumor, and the actual nature of the lesion was discovered at the time of thoracotomy. This case shows the importance of an awareness of this condition in the formulation of a differential diagnosis for a lung mass.

The three-dimensional solution structure of RANTES

The solution structure of the chemokine RANTES (regulated on activation, normal T-cell expressed and secreted) has been determined using NMR spectroscopy. Backbone and side-chain 1H and 15N assignments have been obtained using a combination of two-dimensional homonuclear and three-dimensional heteronuclear spectra. Regular elements of secondary structure have been identified on the basis of a qualitative interpretation of NOE data, J(NH-H alpha) coupling constants, and amide exchange rates. Three-dimensional structures were calculated from a total of 2146 experimental restraints using a combination of distance geometry and simulated annealing protocols. For the 13 best structures the average backbone (N, C alpha, C) atomic rmsd from the mean coordinates for residues 5-65 is 0.64 A (+/- 0.14 A) for the dimer and 0.50 A (+/- 0.08 A) for the individual monomers. Each monomer consists of a three-stranded antiparallel beta-sheet (residues 26-30, 38-43, 48-51) in a Greek key motif with a C-terminal helix (56-65) packed across the sheet, an arrangement similar to the monomeric structure of other members of this chemokine family (IL-8, PF4, MGSA/Gro alpha, and MIP-1 beta). Overall, the RANTES dimer resembles that previously reported for MIP-1 beta.

Health insurance and utilization of medical care for children with special health care needs

Based on analyses of the 1988 National Center for Health Statistics, National Health Interview Survey, Child Health Supplement, this study examines the insurance coverage and utilization of physicians, hospitals, and prescribed medicine among the 9.6 million U.S. children with special health care needs, defined as children who had one or more selected chronic conditions that caused them to experience pain, discomfort, or being upset often or all of the time in the last year, or who were limited in their major childhood activities (playing or going to school) as a result of these or other impairments or health problems. The findings confirmed that substantial variation in access to routine medical care exists among these children. Though health status is an important predictor of which children use services in general, poor, minority children who lived with their mother or someone other than their parents, or those without insurance or an identifiable regular medical provider were most likely to experience financial barriers to access or were less apt to seek care than other children with comparable needs. Access to routine medical care remains particularly problematic for these subsets of children with special health care needs.

Evaluation of antioxidant treatment with superoxide dismutase in rat liver transplantation after warm ischemia

In order to investigate the effects of the exogenously administered radical scavenger superoxide dismutase (SOD) on the orthotopic liver graft, livers from male Wistar rats were transplanted after subjection to 40 min of warm ischemia and 30 min of storage at 4 degrees C. SOD was given at the onset of ischemia and before reperfusion as a supplement (6,000 IU) to the washout solutions. 30,000 IU were infused into the recipient. SOD reduced tissue levels of thiobarbituric acid-reacting substances at the end of ischemia (737 vs. 956 nmol/g; p < 0.01) and 60 min after the onset of reperfusion (629 vs. 947 nmol/g; p < 0.001) and preserved total adenine nucleotides after reperfusion (11.69 vs. 10.40 mumol/g; p < 0.01). Survival 2 weeks after transplantation was 18% (2/11) in the SOD group versus 10% (1/10; nonsignificant) in untreated animals. It is concluded that SOD protects the ischemically altered liver from radical mediated peroxidation and preserves hepatic energy stores upon reperfusion. However, in our model no major improvement in organ viability could by achieved.

Comparison of hepatitis B virus subtyping ofd/y determinants by radioimmunoprecipitation assay and the polymerase chain reaction

Using a double polymerase chain reaction a method was devised for detecting and subtyping hepatitis B virus DNA in serum samples. Primers from the S-gene were selected from the sequence analyses of five HBV HBsAg subtypes, to amplify HBV DNA and subtype for y specific DNA. Thirty-eight samples were subtyped for d and y determinants by radioimmunoprecipitation assay (RIPA) and the polymerase chain reaction (PCR). Subtyping by PCR and RIPA was in agreement in 100% of subtype y samples and 83.3% of subtype d, giving an overall correlation of 92.1%. As a third comparison, 12 amplified samples were digested by the restriction enzyme Sau 3A, which differentiates between subtypes y and d. The digest results agreed with PCR in 83.3% of the samples. In addition, we compared our standard phenol/chloroform extraction against a rapid one step method. The phenol/chloroform stage was found to be essential for the removal of nucleases and polymerase inhibitors present in sera.

A case of Leigh's disease with initial manifestation of dystonia

A case of Leigh's disease (subacute necrotizing encephalomyelopathy) is reported with such noteworthy features as early onset, dystonia, paraparesis the presence of low attenuation areas in both basal ganglias on computerized tomography of the brain and the presence of a high signal intensity in both basal ganglias in T2 weighted image by MR. The electron microscopic findings of muscle biopsy are suggestive of pleoconial mitochondrial myopathy.

Method of determining kidney position as guide for percutaneous nephrostomy

Computed tomography scans were used to assess the distance between the skin and the collecting system in 256 kidneys in 128 adult patients of various heights and weights. Body surface area correlated well with kidney depth. A graph is presented that can be used to calculate kidney depth.

Sensitization potentials of methyl, ethyl, and n-butly methacrylates and mutual cross-sensitivity in guinea pigs

Guinea pigs could be strongly sensitized to methyl, ethyl, and n-butyl methacrylates in ethanol or olive oil by the topical route, or in saline by the intradermal route. For elicitation of skin reactons, topical challenge with the compounds in olive oil or intradermal challenge with saline as the solvent was neccessary. Topical challenge with the methacrylates in ethanol failed to elicit any allergic skin reactions because of their volatility. All sensitized animals responded strongly not only to the inducing methacrylate but also to the other methacrylates, showing that mutual cross-sensitivity had occurred. Since methyl methacrylate has been reported to be a potent sensitizer in humans, the guinea-pig model described here may be useful for screening products before marketing.

Cross-sensitivity of common aminoglycoside antibiotics

Guinea pigs were sensitized to neomycin (A, B, or C), paromomycin, gentamicin, kanamycin, streptomycin, and dihydrostreptomycin via intradermal or foot-pad injection with an adjuvant containing killed Mycobacterium butyricum or M tuberculosis H37Ra (Ra). These antibiotics produced greater cross-sensitization with an increase in the number of immunizations and chemical structural similarities. After repeated intradermal injections (adjuvant Ra) of neomycin, guinea pigs showed cross-sensitization to paromomycin, kanamycin, and streptomycin. A single intradermal injection of one of these antibiotics produced stronger reactions to the most closely related antibiotics, with no meaningful sensitization to the least-related allergens. Streptomycin-sensitized guinea pigs seldom showed a meaningful cross-sensitization to dihydrostreptomycin or the other antibiotics (except neomycin C); however, guinea pigs sensitized to dihydrostreptomycin or the other antibiotics often showed strong cross-sensitization to streptomycin.

Dermal carcinogenicity study by mouse-skin painting with 2,4-toluendediamine alone or in representative hair dye formulations

The chronic toxicity of 2,4-toluenediamine (2,4-TDA) alone or in conbination with a hair dye complex (2,5-toluenediamine, p-phenylenediamine, and resorcinol) was studied in Swiss-Webster mice of both sexes by a skin-painting technique. The predominant neoplasms seen in these mice were primary pulmonary adenomas and adenocarcinomas. Skin neoplasms were seen in most groups of mice, including untreated control mice. Statistical analysis of the incidences of skin neoplasms among the various groups of mice did not show any significant differences. The 2,4-TDA alone or mixed with the hair dye complex did not produce any abnormal proliferation and maturation of the squamous epithelium of the skin. The 2,4-TDA under our experimental conditions was found to be nontoxic and noncarcinogenic to the skin of mice.

Sensitization potentials and immunologic specificities of neomycins

The use of sensitization indices for expressing allergenic skin reactions in guinea pigs is described. The method is convenient for comparing allergens and cross-reacting substances and permits the use of both irritating and nonirritating challenge concentrations of allergens. It also permits determination of both optimal reading time and challenge concentrations for each experiment. By this technique commercial neomycin complex, neamine (neomycin A), neomycin B, neomycin C, and streptomycin were found to be allergenic in guinea pigs via intradermal (id) and foot-pad (fp) immunizations. The immunizing emulsion consisted of an allergen and an adjuvant containing Mycobacterium butyricum (MB) or Mycobacterium tuberculosis H37Ra (Ra). The adjuvant MB was as effective as Ra by the id route, but inferior to Ra by the fp route. The cross-reactivity of neomycin C was generally greater than neomycin B in guinea pigs sensitized to neamine, neomycin B, neomycin C, or streptomycin. In guinea pigs sensitized to neomycin complex by repeated immunizations, neomycins A, B, and C were effective elicitors of skin reactions, whereas the N-acetylated derivatives of the components failed to cause reactions. This finding is interpreted to mean that the amino groups of the aminoglycosides are the coupling sites to host proteins in the processes of sensitization and elicitation of skin reactions in vivo.